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Note: This page contains sample records for the topic "flame retention head" 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.


1

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...

2

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

3

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

4

Coatings for performance retention  

Science Journals Connector (OSTI)

Performance and performance retention are becoming increasingly important in today’s gas turbine engines. The military aircraft engine operator wants the flexibility and flight envelope that increased performance will give and the commercial user—aircraft utility generation or pumper—demands the long term fuel economy that improved performance retention will provide. Materials advances have provided the intrinsic strength and temperature increases to push the capability of today’s engines and coatings have been an integral part of that advancement. Specifically in the performance retention area coatings and seal systems have become increasingly important in both compressor and turbine components. It is the intent of this overview paper to present a brief review of the coating systems presently in use and in development and to consider areas in which the technology might be heading.

R. V. Hillery

1986-01-01T23:59:59.000Z

5

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

6

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

7

Head, Henry  

Science Journals Connector (OSTI)

Abstract English neurologist Sir Henry Head (1861–1940) conducted pioneering clinical studies of the somatosensory system, in addition to conducting important neurophysiological studies of respiratory control mechanisms. Head has been considered as one of the great English clinical neurologists and was a teacher of ‘infectious enthusiasm and vitality.’ Although some of Head's conceptual contributions have not stood the test of time, his diverse contributions were very influential. Among his many contributions were Head's paradoxical reflex (a positive feedback mechanism, which is inter alia important for the first breath of babies), the first reasonably accurate dermatomal map (Head–Campbell dermatomal map), description of the process of recovery from experimental peripheral nerve transection (in himself), the Head–Riddoch syndrome of autonomic dysreflexia, the mass reflex with recovery from spinal shock after spinal cord transection, and the clinically useful distinction between body schema and body image.

D.J. Lanska

2014-01-01T23:59:59.000Z

8

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

9

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

10

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.

11

The Flame Trilogy  

E-Print Network [OSTI]

him and he realized at least a little of the whisky had done its job. It had not obliterated his pain, only anesthetized it a little. It had been his intention to head for home, but his car pulled to a stop outside Starsky's building. He slid... was mad for interrupting his evening, the pain would ease slightly and Hutch could go home and get some sleep. He opened his car door, mind searching for some pretext he could use as his reason for dropping in. As he ascended the stairs, the lights...

Bonds, M.

1999-01-01T23:59:59.000Z

12

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

13

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

14

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

15

Segmented vs conventional numerals: legibility and long term retention  

E-Print Network [OSTI]

the environmental chamber. Sub jects The subjects were thirty male students between the ages of 1g and 27 from the Industrial Engineering department at Texas A&M University. Subjects were divided into three groups of 10. Procedure Exposure time and number... December 1971 Ma]or Subject: Industrial Engineering SEGMENTED VS CONVENTIONAL NUMERALS: LEGIBILITY AND LONG TERM RETENTION A Thesis STEVE EDGAR HILL Approved as to style and content by: Elias Chairman of Committee) r. A. W. ortham (Head...

Hill, Steve Edgar

1971-01-01T23:59:59.000Z

16

Workforce Retention | Department of Energy  

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

Services » Outreach & Collaboration » Focus Groups » Workforce Services » Outreach & Collaboration » Focus Groups » Workforce Retention Workforce Retention The HSS Workforce Retention Work Group was established to collaboratively address the needs of the Department to maintain a skilled work force in the face of anticipated retirements and to address the specific health and safety concerns of that work force that could impede retention. Objectives: Better understand relationship between skilled workforce retention; health, safety and productivity; and especially preventive health care. Inform and support improvement and/or development of wellness, fitness, and prevention programs through data collections and analyses. Promote the implementation of preventive health services designed to assure retention of the contractor work force.

17

Protections: Sediment Control = Contaminant Retention  

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

Sediment Control Protections: Sediment Control Contaminant Retention LANL maintains hundreds of wells, stream sampling stations and stormwater control structures to protect...

18

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

19

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

20

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...

Note: This page contains sample records for the topic "flame retention head" 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

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

22

Relative Retention Data for an Ethofat Column  

Science Journals Connector (OSTI)

......Retention Data for an Ethofat Column David P. Mowry Marathon Oil Company, Littleton, Colorado 80121 ture. RECIPROCAL...Retention Data for an Ethofat Column by David P. Mowry, Marathon 011 Company, Littleton, Colorado 80121 Relative retention......

David P. Mowry

1966-11-01T23:59:59.000Z

23

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

24

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

25

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

26

Technetium Retention During LAW Vitrification  

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

Technetium Retention During Technetium Retention During LAW Vitrification Ian L. Pegg Vitreous State Laboratory The Catholic University of America Washington, DC November 18, 2010 Overview * Tc in borosilcate glass structure * Re as a surrogate for Tc * Summary of previous data on Tc incorporation into LAW glass * Summary of results from ongoing test program * Single-pass retention vs. retention with recycle * Tc volatilization during container filling Tc in LAW Glass Structure * Tc is present as Tc 7+ and Tc 4+ * Tc 7+ is dominant in more oxidized glasses and Tc 4+ is dominant in reduced glasses * Strongly reducing conditions produce Tc 0 * The structure and local environment of Tc in WTP LAW glasses has been investigated by: * Synchrotron X-Ray Absorption Spectroscopy * Lukens, McKeown, Buechele, Muller, Shuh, and Pegg, Chem. Mater., 19, 559 (2007)

27

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

28

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

29

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

30

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

31

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.

32

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.

33

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.

34

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

35

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

36

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

37

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

38

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

39

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

40

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

Note: This page contains sample records for the topic "flame retention head" 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

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

42

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

43

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

44

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.

45

Bottom head assembly  

DOE Patents [OSTI]

A bottom head dome assembly is described which includes, in one embodiment, a bottom head dome and a liner configured to be positioned proximate the bottom head dome. The bottom head dome has a plurality of openings extending there through. The liner also has a plurality of openings extending there through, and each liner opening aligns with a respective bottom head dome opening. A seal is formed, such as by welding, between the liner and the bottom head dome to resist entry of water between the liner and the bottom head dome at the edge of the liner. In the one embodiment, a plurality of stub tubes are secured to the liner. Each stub tube has a bore extending there through, and each stub tube bore is coaxially aligned with a respective liner opening. A seat portion is formed by each liner opening for receiving a portion of the respective stub tube. The assembly also includes a plurality of support shims positioned between the bottom head dome and the liner for supporting the liner. In one embodiment, each support shim includes a support stub having a bore there through, and each support stub bore aligns with a respective bottom head dome opening. 2 figs.

Fife, A.B.

1998-09-01T23:59:59.000Z

46

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

47

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.

48

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

49

Heterosis and Heterosis Retention for Reproductive and Maternal Traits in Nellore-Angus Crossbred Cows  

E-Print Network [OSTI]

HETEROSIS AND HETEROSIS RETENTION FOR REPRODUCTIVE AND MATERNAL TRAITS IN NELLORE-ANGUS CROSSBRED COWS A Dissertation by MOHAMMAD DIYA TALAL HAMED OBEIDAT Submitted to the Office of Graduate Studies of Texas A&M University in partial... fulfillment of the requirements hqt the degree of DOCTOR OF PHILOSOPHY Chair of Committee, David G. Riley Committee Members, James O. Sanders Andy D. Herring Jason E. Sawyer Head of Department, H. Russell Cross August 2013 Major...

Obeidat, Mohammad Diya Talal Hamed

2013-07-08T23:59:59.000Z

50

A Study of Prevention and Retention Strategies for Successful Urban Secondary High School Hispanic Students  

E-Print Network [OSTI]

A STUDY OF PREVENTION AND RETENTION STRATEGIES FOR SUCCESSFUL URBAN SECONDARY HIGH SCHOOL HISPANIC STUDENTS A Dissertation by ROBERTO IBARRA LOPEZ Submitted to the Office of Graduate Studies of Texas A&M University... in partial fulfillment of the requirements for the degree of DOCTOR OF EDUCATION Approved by: Chair of Committee, Mario S. Torres Committee Members, Virginia Collier Larry Dooley Ben Welch Head of Department, Fredrick M. Nafukho May 2013...

Lopez, Roberto I

2013-01-14T23:59:59.000Z

51

Account Sponsorship & Retention Policy | Argonne Leadership Computing...  

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

Allocations MiraCetusVesta Tukey Policies Accounts Policy Account Sponsorship & Retention Policy ALCC Quarterly Report Policy ALCF Acknowledgment Policy Data Policy INCITE...

52

Workforce Retention Work Group | Department of Energy  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

skilled workforce retention; health, safety and productivity; and especially preventive health care. Inform and support improvement andor development of wellness, fitness, and...

53

Radionuclide Retention in Concrete Wasteforms  

SciTech Connect (OSTI)

Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of LLW and MLLW, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

Wellman, Dawn M.; Jansik, Danielle P.; Golovich, Elizabeth C.; Cordova, Elsa A.

2012-09-24T23:59:59.000Z

54

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

55

Maneuvering impact boring head  

DOE Patents [OSTI]

An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure. 8 figs.

Zollinger, W.T.; Reutzel, E.W.

1998-08-18T23:59:59.000Z

56

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.

57

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

58

Child Abuse; Head Injuries  

Science Journals Connector (OSTI)

Abstract Abusive head trauma produces the most long-term morbidity and mortality of all forms of child physical abuse and impacts up to 30 infants per 100 000 births. A great deal of the scientific and lay press has focused on the changes in understanding and the purported controversies surrounding this entity. At the same time, the evidence base for a probabilistic analysis of head injuries and related trauma promises to make the diagnosis more objective, nuanced, and accurate.

S.C. Boos

2014-01-01T23:59:59.000Z

59

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

60

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

Note: This page contains sample records for the topic "flame retention head" 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

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

62

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

63

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

64

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

65

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...

66

Residential Refrigerator Recycling Ninth Year Retention Study  

E-Print Network [OSTI]

Residential Refrigerator Recycling Ninth Year Retention Study Study ID Nos. 546B, 563 Prepared RECYCLING PROGRAMS Study ID Nos. 546B and 563 Prepared for Southern California Edison Rosemead, California

67

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

68

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

69

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.

70

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

71

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

72

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

73

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

74

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

75

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

76

Study of mixture formation and early flame development in a research GDI (gasoline direct injection) engine through numerical simulation and UV-digital imaging  

Science Journals Connector (OSTI)

Abstract The analysis of the mixture formation and early combustion processes in a slightly lean burn gasoline direct injection (GDI) engine is performed by using experimental and numerical techniques. UV–visible natural emission digital imaging is applied in the optically accessible combustion chamber of a research engine. This is equipped with the four-valve head and the same injection system of a commercial turbocharged engine. Optical accessibility is obtained through a quartz window placed on the piston head. Numerical simulations are performed by means of a 3D model developed within the AVL FireTM environment, which exploits an in-house developed sub-model for simulating the spray dynamics. Tests are carried out using commercial gasoline. The cyclic variability of the engine is first analysed in order to properly define a reference average pressure cycle to be used for the validation of the numerical model. This last is then proved as being highly predictive as the start of injection is moved in the working cycle. The main effects of the injection and ignition timing on the characteristic flame development angles, namely on the flame initiation and propagation, are analysed. Flame initiation is visualised both numerically and experimentally.

M. Costa; L. Marchitto; S.S. Merola; U. Sorge

2014-01-01T23:59:59.000Z

77

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

78

DOE Handbook on Recruitment and Retention Incentives | Department of Energy  

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

Handbook on Recruitment and Retention Incentives Handbook on Recruitment and Retention Incentives DOE Handbook on Recruitment and Retention Incentives This desk reference contains sample recruitment, relocation, retention, and student loan incentive plans and service agreements for eligible employees; sample worksheets to assist in documenting the justification and approvals for all types of recruitment and retention incentives; information on superior qualification determinations; guidance and sample documents regarding crediting directly-related service for annual leave for new appointments; frequently asked questions regarding relocation expenses; and other relevant documents. This desk reference is intended to supplement information currently available in the following references. DOE Handbook on Recruitment and Retention Incentives

79

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

80

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 retention head" 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

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

82

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...

83

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

84

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

85

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

86

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

87

Work Force Retention Work Group Charter  

Broader source: Energy.gov [DOE]

The Work force Retention Work Group is established to support the Department’s critical focus on maintaining a high-performing work force at a time when a significant number of the workers needed to support DOE’s national security mission are reaching retirement age.

88

Auditing a database under retention policies  

Science Journals Connector (OSTI)

Auditing the changes to a database is critical for identifying malicious behavior, maintaining data quality, and improving system performance. But an accurate audit log is an historical record of the past that can also pose a serious threat to privacy. ... Keywords: Auditing, Privacy, Retention policy

Wentian Lu; Gerome Miklau; Neil Immerman

2013-04-01T23:59:59.000Z

89

Task Force on Undergraduate Retention and Graduation: Meeting Documentation  

E-Print Network [OSTI]

1 Task Force on Undergraduate Retention and Graduation: Meeting Documentation April 28, 2011 Part 1 such as tenacity impacting retention and graduation are more difficult to measure and have not been tracked

Bieber, Michael

90

Recruiting, Retention & Advancement Recruiting: Searching for Excellence and  

E-Print Network [OSTI]

#12;Recruiting, Retention & Advancement Recruiting: Searching for Excellence and Diversity: A Workshop for Faculty Search Committee Chairs Retention: Enhancing Department Climate: A Chair's Role Advancement: Senior women meetings #12;Recruiting 3-part workshops for chairs of hiring committees Based

Sheridan, Jennifer

91

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

92

300 Area Building Retention Evaluation Mitigation Plan  

SciTech Connect (OSTI)

Evaluate the long-term retention of several facilities associated with the PNNL Capability Replacement Laboratory and other Hanfor mission needs. WCH prepared a mitigation plan for three scenarios with different release dates for specific buildings. The evaluations present a proposed plan for providing utility services to retained facilities in support of a long-term (+20 year) lifespan in addition to temporary services to buildings with specified delayed release dates.

D. J. McBride

2007-07-03T23:59:59.000Z

93

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

94

Deuterium Retention in NSTX with Lithium Conditioning  

SciTech Connect (OSTI)

High (approximate to 90%) deuterium retention was observed in NSTX gas balance measurements both with- and without lithiumization of the carbon plasma-facing components. The gas retained in ohmic discharges was measured by comparing the vessel pressure rise after a discharge to that of a gas-only pulse with the pumping valves closed. For neutral beam heated discharges the gas input and gas pumped by the NB cryopanels were tracked. The discharges were followed by outgassing of deuterium that reduced the retention. The relationship between retention and surface chemistry was explored with a new plasma-material interface probe connected to an in vacuo surface science station that exposed four material samples to the plasma. XPS and TDS analysis demonstrated that binding of D atoms in graphite is fundamentally changed by lithium - in particular atoms are weakly bonded in regions near lithium atoms bound to either oxygen or the carbon matrix. This is in contrast to the strong ionic bonding that occurs between D and pure Li. (C) 2010 Elsevier B.V. All rights reserved.

Skinner, C. H. [Princeton Plasma Physics Laboratory (PPPL); Allain, J. P. [Purdue University; Blanchard, W. [Princeton Plasma Physics Laboratory (PPPL); Kugel, H. W. [Princeton Plasma Physics Laboratory (PPPL); Maingi, Rajesh [ORNL; Roquemore, L. [Princeton Plasma Physics Laboratory (PPPL); Soukhanovskii, V. A. [Lawrence Livermore National Laboratory (LLNL); Taylor, C. N. [Purdue University

2011-01-01T23:59:59.000Z

95

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

96

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

97

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

98

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...

99

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

100

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

Note: This page contains sample records for the topic "flame retention head" 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

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

102

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

103

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

104

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

105

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

106

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

107

Factors Associated with Recruitment and Retention Rates of Minority Youth 4-H Members as Perceived by Adult Club Leaders and County Extension Agents in Texas  

E-Print Network [OSTI]

FACTORS ASSOCIATED WITH RECRUITMENT AND RETENTION RATES OF MINORITY YOUTH 4-H MEMBERS AS PERCEIVED BY ADULT CLUB LEADERS AND COUNTY EXTENSION AGENTS IN TEXAS A Thesis by NICOLE ANN GONZALES Submitted to the Office of Graduate.... Holub Head of Department, Jack Elliot December 2012 Major Subject: Agricultural Leadership, Education, and Communications Copyright 2012 Nicole Ann Gonzales ii ABSTRACT According to enrollment data from the National 4-H Headquarters...

Gonzales, Nicole 1989-

2012-12-05T23:59:59.000Z

108

Heater head for stirling engine  

DOE Patents [OSTI]

A monolithic heater head assembly which augments cast fins with ceramic inserts which narrow the flow of combustion gas and obtains high thermal effectiveness with the assembly including an improved flange design which gives greater durability and reduced conduction loss.

Corey, John A. (R.D. #2, Box 101 E, North Troy, NY 12182)

1985-07-09T23:59:59.000Z

109

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

110

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

111

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.

112

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

113

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

114

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

115

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

116

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

117

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.

118

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

119

Cooking utensil with improved heat retention  

DOE Patents [OSTI]

A cooking utensil with improved heat retention includes an inner pot received within an outer pot and separated in a closely spaced-apart relationship to form a volume or chamber therebetween. The chamber is evacuated and sealed with foil leaves at the upper edges of the inner and outer pot. The vacuum created between the inner and outer pot, along with the minimum of thermal contact between the inner and outer pot, and the reduced radiative heat transfer due to low emissivity coatings on the inner and outer pot, provide for a highly insulated cooking utensil. Any combination of a plurality of mechanisms for selectively disabling and re-enabling the insulating properties of the pot are provided within the chamber. These mechanisms may include: a hydrogen gas producing and reabsorbing device such as a metal hydride, a plurality of metal contacts which can be adjusted to bridge the gap between the inner and outer pot, and a plurality of bimetallic switches which can selectively bridge the gap between the inner and outer pot. In addition, phase change materials with superior heat retention characteristics may be provided within the cooking utensil. Further, automatic and programmable control of the cooking utensil can be provided through a microprocessor and associated hardware for controlling the vacuum disable/enable mechanisms to automatically cook and save food.

Potter, Thomas F. (Denver, CO); Benson, David K. (Golden, CO); Burch, Steven D. (Golden, CO)

1997-01-01T23:59:59.000Z

120

Radionuclide Retention in Concrete Wasteforms - FY13  

SciTech Connect (OSTI)

Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of low-level waste and mixed low-level waste, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

Snyder, Michelle MV; Golovich, Elizabeth C.; Wellman, Dawn M.; Crum, Jarrod V.; Lapierre, Robert; Dage, Denomy C.; Parker, Kent E.; Cordova, Elsa A.

2013-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "flame retention head" 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

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

122

Heater head for Stirling engine  

SciTech Connect (OSTI)

This patent describes a heater head for a Stirling engine comprising: a housing for enclosing the heater head with gas at a substantial elevated pressure; insulator means attached to the housing for insulating the heater head; inlet means attached to a regenerator in the housing for admission of relatively high pressure working fluid from the regenerator of a Stirling engine; a first annular heating wall in the housing attached to the inlet means for heating the working fluid; and, a second annular heating wall in the housing concentric with the first heating wall but of lesser diameters so that an annular space is formed between the first heating wall and the second heating wall for heating working fluid; and a third heating wall in the housing concentric with and smaller in diameter than the second heating wall forming the condensing area of a heat pipe between the second heating wall and the third heating wall.

White, M.A.; Emigh, S.G.

1987-06-09T23:59:59.000Z

123

Volatile Species Retention During Metallic Fuel Casting  

SciTech Connect (OSTI)

Metallic nuclear fuels are candidate transmutation fuel forms for advanced fuel cycles. Through the operation of the Experimental Breeder Reactor II metallic nuclear fuels have been shown to be robust and easily manufactured. However, concerns have been raised concerning loss of americium during the casting process because of its high vapor pressure. In order to address these concerns a gaseous diffusion model was developed and a series of experiments using both manganese and samarium as surrogates for americium were conducted. The modeling results showed that volatility losses can be controlled to essentially no losses with a modest overpressure. Experimental results also showed volatile species retention down to no detectable losses through overpressure, although the loss values varied from the model results the same trend was seen. Bases on these results it is very probably that americium losses through volatility can be controlled to no detectable losses through application of a modest overpressure during casting.

Randall S. Fielding; Douglas L. Proter

2013-10-01T23:59:59.000Z

124

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

125

Water retention and gas relative permeability of two industrial concretes  

SciTech Connect (OSTI)

This experimental study aims at identifying the water retention properties of two industrial concretes to be used for long term underground nuclear waste storage structures. Together with water retention, gas transfer properties are identified at varying water saturation level, i.e. relative gas permeability is assessed directly as a function of water saturation level S{sub w}. The influence of the initial de-sorption path and of the subsequent re-saturation are analysed both in terms of water retention and gas transfer properties. Also, the influence of concrete microstructure upon water retention and relative gas permeability is assessed, using porosity measurements, analysis of the BET theory from water retention properties, and MIP. Finally, a single relative gas permeability curve is proposed for each concrete, based on Van Genuchten-Mualem's statistical model, to be used for continuous modelling approaches of concrete structures, both during drying and imbibition.

Chen Wei; Liu Jian; Brue, Flore; Skoczylas, Frederic [Univ Lille Nord de France, F-59000 Lille (France); ECLille, LML, BP 48, F-59650 Villeneuve d'Ascq (France); CNRS, UMR 8107, F-59650 Villeneuve d'Ascq (France); Davy, C.A., E-mail: catherine.davy@ec-lille.fr [Univ Lille Nord de France, F-59000 Lille (France); ECLille, LML, BP 48, F-59650 Villeneuve d'Ascq (France); CNRS, UMR 8107, F-59650 Villeneuve d'Ascq (France); Bourbon, Xavier; Talandier, Jean [Andra, 1-7 rue Jean Monnet, F-92298 Chatenay-Malabry Cedex (France)

2012-07-15T23:59:59.000Z

126

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

127

Pressure testing of torispherical heads  

SciTech Connect (OSTI)

Two vessels fabricated from SA516-70 steel with 6% knuckle radius torispherical heads were tested under internal pressure to failure. The D/t ratios of Vessel 1 and Vessel 2 were 238 and 185 respectively. The calculated maximum allowable working pressures of Vessel 1 and 2 heads using the ASME Section 8, Div. 1 rules and measured dimensions were 85 and 110 psi, respectively. Vessel 1 failed at a nozzle weld in the cylindrical shell at 700 psi pressure. Neither buckling nor any other objectionable deformation of the head was observed at a theoretical double-elastic-slope collapse pressure of 241 and a calculated buckling pressure of 270 psi. Buckles were observed developing slowly after 600 psi pressure, and a total of 22 buckles were observed after the test, having the maximum amplitude of 0.15 inch. Vessel 2 failed at the edge of the longitudinal weld of the cylindrical shell at 1,080 psi pressure. Neither buckling nor any other objectionable deformation of the head was observed up to the final pressure, which exceeded the theoretical double-elastic-slope collapse and calculated buckling pressures of 274 psi and 342 psi, respectively.

Rana, M.D. [Praxair, Inc., Tonawanda, NY (United States). Research and Development Dept.; Kalnins, A.; Updike, D.P. [Lehigh Univ., Bethlehem, PA (United States)

1995-12-01T23:59:59.000Z

128

E-Print Network 3.0 - analysis retention behaviour Sample Search...  

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

retention, which... the criterion for retention analysis) into account (Table 1). Kruskal-Wallis ANOVA revealed a significant effect... Part One SCN AND MEMORY PROCESSES...

129

E-Print Network 3.0 - affects mibg retention Sample Search Results  

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

constipation, functional fecal retention, and non-retentive fecal soiling. A... time. Boys and girls are equally affected. 12;Infant Dyschezia Dyschezia ... Source: Louisiana...

130

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

131

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

132

In-vessel coolability and retention of a core melt. Volume 2  

SciTech Connect (OSTI)

The efficacy of external flooding of a reactor vessel as a severe accident management strategy is assessed for an AP600-like reactor design. The overall approach is based on the Risk Oriented Accident Analysis Methodology (ROAAM), and the assessment includes consideration of bounding scenarios and sensitivity studies, as well as arbitrary parametric evaluations that allow the delineation of the failure boundaries. Quantification of the input parameters is carried out for an AP600-like design, and the results of the assessment demonstrate that lower head failure is physically unreasonable. Use of this conclusion for any specific application is subject to verifying the required reliability of the depressurization and cavity-flooding systems, and to showing the appropriateness (in relation to the database presented here, or by further testing as necessary) of the thermal insulation design and of the external surface properties of the lower head, including any applicable coatings. The AP600 is particularly favorable to in-vessel retention. Some ideas to enhance the assessment basis as well as performance in this respect, for applications to larger and/or higher power density reactors are also provided.

Theofanous, T.G.; Liu, C.; Additon, S.; Angelini, S.; Kymaelaeinen, O.; Salmassi, T. [California Univ., Santa Barbara, CA (United States). Center for Risk Studies and Safety

1996-10-01T23:59:59.000Z

133

The 'Sphinx' Head from the Cult Center at Mycenae  

E-Print Network [OSTI]

This study identifies the well-known plaster female head (often called a sphinx head) as the head of a cult statue.

Rehak, Paul

2005-01-01T23:59:59.000Z

134

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

135

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-...

136

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

137

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....

138

Hanford Facility dangerous waste permit application, liquid effluent retention facility and 200 area effluent treatment facility  

SciTech Connect (OSTI)

The Hanford Facility Dangerous Waste Permit Application is considered to 10 be a single application organized into a General Information Portion (document 11 number DOE/RL-91-28) and a Unit-Specific Portion. The scope of the 12 Unit-Specific Portion is limited to Part B permit application documentation 13 submitted for individual, `operating` treatment, storage, and/or disposal 14 units, such as the Liquid Effluent Retention Facility and 200 Area Effluent 15 Treatment Facility (this document, DOE/RL-97-03). 16 17 Both the General Information and Unit-Specific portions of the Hanford 18 Facility Dangerous Waste Permit Application address the content of the Part B 19 permit application guidance prepared by the Washington State Department of 20 Ecology (Ecology 1987 and 1996) and the U.S. Environmental Protection Agency 21 (40 Code of Federal Regulations 270), with additional information needs 22 defined by the Hazardous and Solid Waste Amendments and revisions of 23 Washington Administrative Code 173-303. For ease of reference, the Washington 24 State Department of Ecology alpha-numeric section identifiers from the permit 25 application guidance documentation (Ecology 1996) follow, in brackets, the 26 chapter headings and subheadings. A checklist indicating where information is 27 contained in the Liquid Effluent Retention Facility and 200 Area Effluent 28 Treatment Facility permit application documentation, in relation to the 29 Washington State Department of Ecology guidance, is located in the Contents 30 Section. 31 32 Documentation contained in the General Information Portion is broader in 33 nature and could be used by multiple treatment, storage, and/or disposal units 34 (e.g., the glossary provided in the General Information Portion). Wherever 35 appropriate, the Liquid Effluent Retention Facility and 200 Area Effluent 36 Treatment Facility permit application documentation makes cross-reference to 37 the General Information Portion, rather than duplicating text. 38 39 Information provided in this Liquid Effluent Retention Facility and 40 200 Area Effluent Treatment Facility permit application documentation is 41 current as of June 1, 1997.

Coenenberg, J.G.

1997-08-15T23:59:59.000Z

139

Formation and retention of methane in coal  

SciTech Connect (OSTI)

The formation and retention of methane in coalbeds was studied for ten Utah coal samples, one Colorado coal sample and eight coal samples from the Argonne Premium Coal Sample Bank.Methane gas content of the Utah and Colorado coals varied from zero to 9 cm{sup 3}/g. The Utah coals were all high volatile bituminous coals. The Colorado coal was a gassy medium volatile bituminous coal. The Argonne coals cover a range or rank from lignite to low volatile bituminous coal and were used to determine the effect of rank in laboratory studies. The methane content of six selected Utah coal seams and the Colorado coal seam was measured in situ using a special sample collection device and a bubble desorbometer. Coal samples were collected at each measurement site for laboratory analysis. The cleat and joint system was evaluated for the coal and surrounding rocks and geological conditions were noted. Permeability measurements were performed on selected samples and all samples were analyzed for proximate and ultimate analysis, petrographic analysis, {sup 13}C NMR dipolar-dephasing spectroscopy, and density analysis. The observed methane adsorption behavior was correlated with the chemical structure and physical properties of the coals.

Hucka, V.J.; Bodily, D.M.; Huang, H.

1992-05-15T23:59:59.000Z

140

Characterization of Thermal Response Induced by Head/Disk Interaction in Current TGMR Head  

E-Print Network [OSTI]

, resulting in variations in head flying characteristics. Therefore, head- disk interaction in real disk driveCharacterization of Thermal Response Induced by Head/Disk Interaction in Current TGMR Head Suwatana with a lower areal resistance (RA) value. However, as the areal density increases, the actual flying clearance

Kovintavewat, Piya

Note: This page contains sample records for the topic "flame retention head" 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

September 2012, Work Force Retention Work Group Status Overview  

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

Work Force Retention Work Group Status Overview Work Force Retention Work Group Status Overview 2 Subgroups: Pro-Force and Non-Pro-Force Pro-Force Subgroup: Accomplishments: 1. Completion of 10 CFR 1046 [Protective Force Personnel Medical, Physical Readiness, Training, and Access Authorization Standards] as a final rule that includes modification efforts to address barriers to workforce retention. 2. Pro-Force (PF) union representative, Randy Lawson, identified this accomplishment as the single most significant step toward PF workforce retention in over 20 years. 3. Draft re-charter of PF Career Options Committee (PFCOC) to establish a PF Working Group approved by GC-63 and GC NNSA. Near Term Goals and Activities: 1. Publish 1046 as a final rule - publication anticipated this month.

142

July 2012, Work Force Retention Work Group Status Overview  

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

Work Force Retention Work Group Status Overview Work Force Retention Work Group Status Overview Accomplishments: 1. Progress on the completion of the 10 CFR 1046 modifications to address barriers to workforce retention. Written response to public comment is being drafted by HS-51. 2. Pro-Force (PF) union representative, Randy Lawson, identified this accomplishment as the single most significant step toward PF workforce retention in over 20 years. 3. Draft re-charter of PF Career Options Committee (PFCOC) to establish a PF Working Group approved by GC-63 and GC NNSA. Near Term Goals and Activities: 1. Publish 1046 as a final rule - anticipated completion no later than September, assuming timely OMB review and approval. 2. Draft PF Working Group charter final review by senior management to be

143

Task Force on Undergraduate Retention and Graduation: Meeting Documentation  

E-Print Network [OSTI]

1 Task Force on Undergraduate Retention and Graduation: Meeting Documentation March 17, 2011 Part 1 Altenkirch Charge to the Committee, February 3, 2011 Meeting Date: March 17, 2011; minutes revised on April

Bieber, Michael

144

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

145

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

146

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

147

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

148

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

149

Bubble retention in synthetic sludge: Testing of alternative gas retention apparatus  

SciTech Connect (OSTI)

Several of the underground storage tanks currently used to store waste at Hanford have been placed on the Flammable Gas Watch List, because the waste is either known or suspected to generate, store, and episodically release flammable gases. The objective of this experimental study is to develop a method to measure gas bubble retention in simulated tank waste and in diluted simulant. The method and apparatus should (1) allow for reasonably rapid experiments, (2) minimize sample disturbance, and (3) provide realistic bubble nucleation and growth. The scope of this experimental study is to build an apparatus for measuring gas retention in simulated waste and to design the apparatus to be compatible with future testing on actual waste. The approach employed for creating bubbles in sludge involves dissolving a soluble gas into the supernatant liquid at an elevated pressure, recirculating the liquid containing the dissolved gas through the sludge, then reducing the pressure to allow bubbles to nucleate and grow. Results have been obtained for ammonia as the soluble gas and SY1-SIM-91A, a chemically representative simulated tank waste. In addition, proof-of-principle experiments were conducted with both ammonia and CO{sub 2} as soluble gases and sludge composed of 90-micron glass beads. Results are described.

Rassat, S.D.; Gauglitz, P.A.

1995-07-01T23:59:59.000Z

150

Thirtieth anniversary of the retention index according to Kováts in gas-liquid chromatography  

Science Journals Connector (OSTI)

GC retention data measured in various laboratories are given in many different forms and therefore their usefulness is limited. The retention index system according to Kováts solves the problem of the uniform expression of retention data. In this review, the main theoretical and practical results relating to retention index systems published in the past 5 years are summarized.

G. Tarján; Sz. Nyiredy; M. Györ; E.R. Lombosi; T.S. Lombosi; M.V. Budahegyi; S.Y. Mészáros; J.M. Takács

1989-01-01T23:59:59.000Z

151

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

152

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

153

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

154

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

155

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

156

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

157

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

158

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

159

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

160

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

Note: This page contains sample records for the topic "flame retention head" 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

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

162

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

163

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

164

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

165

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

166

Reactor Pressure Vessel Head Packaging & Disposal  

SciTech Connect (OSTI)

Reactor Pressure Vessel (RPV) Head replacements have come to the forefront due to erosion/corrosion and wastage problems resulting from the susceptibility of the RPV Head alloy steel material to water/boric acid corrosion from reactor coolant leakage through the various RPV Head penetrations. A case in point is the recent Davis-Besse RPV Head project, where detailed inspections in early 2002 revealed significant wastage of head material adjacent to one of the Control Rod Drive Mechanism (CRDM) nozzles. In lieu of making ASME weld repairs to the damaged head, Davis-Besse made the decision to replace the RPV Head. The decision was made on the basis that the required weld repair would be too extensive and almost impractical. This paper presents the packaging, transport, and disposal considerations for the damaged Davis-Besse RPV Head. It addresses the requirements necessary to meet Davis Besse needs, as well as the regulatory criteria, for shipping and burial of the head. It focuses on the radiological characterization, shipping/disposal package design, site preparation and packaging, and the transportation and emergency response plans that were developed for the Davis-Besse RPV Head project.

Wheeler, D. M.; Posivak, E.; Freitag, A.; Geddes, B.

2003-02-26T23:59:59.000Z

167

Reactive barriers for {sup 137}Cs retention  

SciTech Connect (OSTI)

{sup 137}Cs was dispersed globally by cold war activities and, more recently, by the Chernobyl accident. Engineered extraction of {sup 137}Cs from soils and groundwaters is exceedingly difficult. Because the half life of {sup 137}Cs is only 30.2 years, remediation might be more effective (and less costly) if {sup 137}Cs bioavailability could be demonstrably limited for even a few decades by use of a reactive barrier. Essentially permanent isolation must be demonstrated in those few settings where high nuclear level wastes contaminated the environment with {sup 135}Cs (half life 2.3x10{sup 6} years) in addition to {sup 137}Cs. Clays are potentially a low-cost barrier to Cs movement, though their long-term effectiveness remains untested. To identify optimal clays for Cs retention Cs resorption was measured for five common clays: Wyoming Montmorillonite (SWy-1), Georgia Kaolinites (KGa-1 and KGa-2), Fithian Illite (F-Ill), and K-Metabentonite (K-Mbt). Exchange sites were pre-saturated with 0.16 M CsCl for 14 days and readily exchangeable Cs was removed by a series of LiNO{sub 3} and LiCl washes. Washed clay were then placed into dialysis bags and the Cs release to the deionized water outside the bags measured. Release rates from 75 to 139 days for SWy-1, K-Mbt and F- 111 were similar; 0.017 to 0.021% sorbed Cs released per day. Both kaolinites released Cs more rapidly (0.12 to 0.05% of the sorbed Cs per day). In a second set of experiments, clays were doped for 110 days and subjected to an extreme and prolonged rinsing process. All the clays exhibited some capacity for irreversible Cs uptake so most soils have some limited ability to act as a natural barrier to Cs migration. However, the residual loading was greatest on K-Mbt ({approximately} 0.33 wt% Cs). Thus, this clay would be the optimal material for constructing artificial reactive barriers.

KRUMHANSL,JAMES L.; BRADY,PATRICK V.; ANDERSON,HOWARD L.

2000-05-19T23:59:59.000Z

168

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

169

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

170

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

171

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

172

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

173

Portable conduit retention apparatus for releasably retaining a conduit therein  

DOE Patents [OSTI]

Portable conduit retention apparatus for releasably retaining a conduit therein. The apparatus releasably retains the conduit out of the way of nearby personnel and equipment. The apparatus includes a portable support frame defining a slot therein having an open mouth portion in communication with the slot for receiving the conduit through the open mouth portion and into the slot. A retention bar is pivotally connected to the support frame adjacent the mouth portion for releasably retaining the conduit in the slot. The retention bar freely pivots to a first position, so that the mouth portion is unblocked in order that the conduit is received through the mouth portion and into the slot. In addition, the retention bar freely pivots to a second position, so that the mouth portion is blocked in order that the conduit is retained in the slot. The conduit is released from the slot by pivoting the retention bar to the first position to unblock the mouth portion and thereafter manipulating the conduit from the slot and through the mouth portion. The apparatus may further include a mounting member attached to the support frame for mounting the apparatus on a vertical support surface. Another embodiment of the apparatus includes a shoe assembly of predetermined weight removably connected to the support frame for resting the apparatus on a floor in such a manner that the apparatus is substantially stationary on the floor.

Metzger, Richard H. (West Seneca, NY)

1998-01-01T23:59:59.000Z

174

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

175

SUBJECT: Guidance on Retention of Facility Representative Technical  

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

SUBJECT: Guidance on Retention of Facility Representative Technical SUBJECT: Guidance on Retention of Facility Representative Technical Competence during Reductions in Force, 4/21/1998 SUBJECT: Guidance on Retention of Facility Representative Technical Competence during Reductions in Force, 4/21/1998 The Department's Revised Implementation Plan (IP) for Defense Nuclear Facilities Safety Board Recommendation 93-3 renews the Department's commitment to maintaining the technical capability necessary to safely manage and operate defense nuclear facilities. Retaining highly qualified employees in critical technical skills areas is vital to the maintenance of these technical capabilities. The Department has therefore committed in the revised R? to the development of a model that offices can use to proactively manage and preserve critical technical capabilities. During the

176

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

177

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

178

Head wear reduction in future hard-disk drives  

Science Journals Connector (OSTI)

Head wear and head vibration due to head-disk contact are two main issues that must be resolved for the future high-density Hard Disk Drives (HDDs). To reduce head wear, disk lubricant, carbon overcoat films on head and disk surfaces, head flying characteristics and so on have been studied. In this paper, we first show the effects of several parameters on head wear, including lubricant types, their MW, and disk burnishing. Our recent results on the effects of humidity and temperature on head wear are also explained. We then explain our extended wear equation and estimate the head wear life with present technologies.

Youichi Kawakubo; Shinnichi Nakazawa; Shinnichi Kobatake

2008-01-01T23:59:59.000Z

179

Research CtteeEducation Div Heads Faculty  

E-Print Network [OSTI]

& Action Plans School Review Reports Review Co-ordinator drafts Report Report sent to Chair of review panel and approved by UPARC School Review Action Plan Review Co-ordinator sends Action Plan template for completion (and Review Report for information) to Faculty School Relevant Divisional Head/s Complete Action Plan

Bristol, University of

180

RICHARD N. PALMER Professor and Head  

E-Print Network [OSTI]

Resources Engineers, #00191 Professional History Professor and Head, Department of Civil and Environmental1 RICHARD N. PALMER Professor and Head Department of Civil and Environmental Engineering University.D. Environmental Engineering, Johns Hopkins University 1979 M.S. Environmental Engineering, Stanford University

Mountziaris, T. J.

Note: This page contains sample records for the topic "flame retention head" 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

Head of Safety 020 7679 1948  

E-Print Network [OSTI]

Head of Safety Paul Stirk 020 7679 1948 (Internal 41948) p.stirk@ucl.ac.uk Deputy Head of Safety & Biological Safety Advisor Jillian Deans 020 7679 1814 (Internal 41814) j.deans@ucl.ac.uk Safety Training Manager Kuen Yip Porter 020 7679 1299 (Internal 41299) k.yip-porter@ucl.ac.uk Safety Advisors Rhona Brown

Guillas, Serge

182

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

183

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

184

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

185

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

186

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

187

Evolutionary Computing for Detection of Retentive Structures in Coastal Waters  

E-Print Network [OSTI]

,robillia,poty,fonlupt}@lil.univ-littoral.fr, Abstract-- The demography of anchovy fishes in the Gulf of Biscay seems to be related to the presence of so- called "retentive" hydrodynamical structures, that keep fish eggs and larvae in a favorable environment be used to decide fishing quotas or bans for the sake of preserving the natural resource. We propose two

Fernandez, Thomas

188

Arsenate and Chromate Retention Mechanisms on Goethite. 2.  

E-Print Network [OSTI]

Arsenate and Chromate Retention Mechanisms on Goethite. 2. Kinetic Evaluation Using a Pressure on goethite (R-FeOOH) were investigated using apressure-jump(p-jump)relaxationtechnique. Information provided. The adsorption/desorption of these oxyanions on goethite involved a double relaxation event. The proposed

Sparks, Donald L.

189

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

190

Anticipation in the Rodent Head Direction System Can Be Explained by an Interaction of Head Movements and Vestibular Firing Properties  

E-Print Network [OSTI]

Anticipation in the Rodent Head Direction System Can Be Explained by an Interaction of Head Rossum MC. Anticipation in the rodent head direction system can be explained by an interaction of head, 2007; doi:10.1152/jn.00233.2007. The rodent head-direction (HD) system, which codes for the animal

van Rossum, Mark

191

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

192

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

193

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

194

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

195

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

196

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

197

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

198

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

199

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

200

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

Note: This page contains sample records for the topic "flame retention head" 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

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

202

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

203

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).

204

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

205

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

206

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

207

Bear Head LNG Corporation and Bear Head LNG (USA), LLC FE Docket No. 15-14-NG  

Broader source: Energy.gov [DOE]

On January 23, 2015, Bear Head LNG Corporation and Bear Head LNG (USA), LLC (together, “Bear Head LNG”), filed an application for long-term, multi-contract authorization to engage in imports from,...

208

INTERNAL POSTING - Head of Technology Transfer, Patents & Publications...  

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

INTERNAL POSTING - Head of Technology Transfer, Patents & Publications Department: Best Practices Supervisor(s): John Delooper Staff: AM 7 Requisition Number: 1400936 The Head of...

209

Los Alamos National Laboratory names new head of weapons programs  

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

Laboratory names new head of weapons programs Los Alamos National Laboratory names new head of weapons programs Bret Knapp has been acting in that position since June 2011....

210

Nanotechnology in Head and Neck Cancer: The Race Is On  

E-Print Network [OSTI]

10.1007/s11912-010-0087-2 Nanotechnology in Head and Neckthe applications of nanotechnology in head and neck cancer,plasmonic gold nanotechnology. Keywords Nanotechnology .

El-Sayed, Ivan H.

2010-01-01T23:59:59.000Z

211

DOE Head Contracting Authority (HCA) and Procurement Director...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

DOE Head Contracting Authority (HCA) and Procurement Director (PD) Directory DOE Head Contracting Authority (HCA) and Procurement Director (PD) Directory HCA and PD List Sept 23...

212

Mars mission laser tool heads to JPL  

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

Mars mission laser tool Mars mission laser tool heads to JPL Curiosity will carry the newly delivered laser instrument to reveal which elements are present in Mars' rocks and...

213

TMI-2 reactor vessel head removal  

SciTech Connect (OSTI)

This report describes the safe removal and storage of the Three Mile Island Unit 2 reactor vessel head. The head was removed in July 1984 to permit the removal of the plenum and the reactor core, which were damaged during the 1979 accident. From July 1982, plans and preparations were made using a standard head removal procedure modified by the necessary precautions and changes to account for conditions caused by the accident. After data acquisition, equipment and structure modifications, and training the head was safely removed and stored and the internals indexing fixture and a work platform were installed on top of the vessel. Dose rates during and after the operation were lower than expected; lessons were learned from the operation which will be applied to the continuing fuel removal operations activities.

Bengel, P.R.; Smith, M.D.; Estabrook, G.A.

1984-12-01T23:59:59.000Z

214

TMI-2 reactor vessel head removal  

SciTech Connect (OSTI)

This report describes the safe removal and storage of the Three Mile Island Unit 2 (TMI-2) reactor vessel head. The head was removed in July 1984 to permit the removal of the plenum and the reactor core, which were damaged during the 1979 accident. From July 1982, plans and preparations were made using a standard head removal procedure modified by the necessary precautions and changes to account for conditions caused by the accident. After data acquisition, equipment and structure modifications, and training, the head was safely removed and stored; and the internals indexing fixture and a work platform were installed on top of the vessel. Dose rates during and after the operation were lower than expected; lessons were learned from the operation which will be applied to the continuing fuel removal operations activities.

Bengel, P.R.; Smith, M.D.; Estabrook, G.A.

1985-09-01T23:59:59.000Z

215

Heater head for a Stirling engine  

SciTech Connect (OSTI)

A heater head is described for a compound Stirling engine modules, each including a displacer cylinder coaxially aligned with the displacer cylinder of the other of the engine modules, a displacer piston mounted for reciprocation in the displacer cylinder.

Darooka, D.K.

1988-09-06T23:59:59.000Z

216

Does Head Start help hispanic children?  

Science Journals Connector (OSTI)

Poor educational attainment is a persistent problem among US hispanic children, relative to non-hispanics. Many of these children are immigrants and/or come from households that use a minority language in the home. This paper examines the effects of participation in a government sponsored preschool program called Head Start on these children. We find that large and significant benefits accrue to Head Start children when we compare them to siblings who did not participate in the program. On average, Head Start closes at least 1/4 of the gap in test scores between hispanic children and non-hispanic white children, and 2/3 of the gap in the probability of grade repetition. However, we find that the benefits of Head Start are not evenly distributed across sub-groups.

Janet Currie; Duncan Thomas

1999-01-01T23:59:59.000Z

217

SPATIAL TRANSFORMATIONS 1 Running head: Spatial transformations  

E-Print Network [OSTI]

SPATIAL TRANSFORMATIONS 1 Running head: Spatial transformations Multiple Systems for Spatial Imagery: Transformations of Objects and Bodies Jeffrey M. Zacks* and Barbara Tversky * Washington COGNITION & COMPUTATION #12;SPATIAL TRANSFORMATIONS 2 Abstract Problem-solving often requires imagining

Zacks, Jeffrey M.

218

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

219

Selective control of SNARE recycling by Golgi retention  

Science Journals Connector (OSTI)

Abstract Two distinct sets of soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE) catalyze membrane fusion in the cis-Golgi and trans-Golgi. The mechanism that controls Golgi localization of \\{SNAREs\\} remains largely unknown. Here we tested three potential mechanisms, including vesicle recycling between the Golgi and the endoplasmic reticulum, partitioning in Golgi lipid microdomains, and selective intra-Golgi retention. Recycling rates showed a linear relationship with intra-Golgi mobility of SNAREs. The cis-Golgi \\{SNAREs\\} had higher mobility than intra-Golgi SNAREs, whereas vesicle \\{SNAREs\\} had higher mobility than target membrane SNAREs. The differences in SNARE mobility were not due to preferential partitioning into detergent-resistant membrane microdomains. We propose that intra-Golgi retention precludes entropy-driven redistribution of \\{SNAREs\\} to the endoplasmic reticulum and endocytic compartments.

Masayoshi Fukasawa; Anda Cornea; Oleg Varlamov

2013-01-01T23:59:59.000Z

220

Electro-optic voltage sensor head  

DOE Patents [OSTI]

The invention is an electro-optic voltage sensor head designed for integration with existing types of high voltage transmission and distribution apparatus. The sensor head contains a transducer, which comprises a transducing material in which the Pockels electro-optic effect is observed. In the practice of the invention at least one beam of electromagnetic radiation is routed into the transducing material of the transducer in the sensor head. The beam undergoes an electro-optic effect in the sensor head when the transducing material is subjected to an E-field. The electro-optic effect is observed as a differential phase a shift, also called differential phase modulation, of the beam components in orthogonal planes of the electromagnetic radiation. In the preferred embodiment the beam is routed through the transducer along an initial axis and then reflected by a retro-reflector back substantially parallel to the initial axis, making a double pass through the transducer for increased measurement sensitivity. The preferred embodiment of the sensor head also includes a polarization state rotator and at least one beam splitter for orienting the beam along major and minor axes and for splitting the beam components into two signals which are independent converse amplitude-modulated signals carrying E-field magnitude and hence voltage information from the sensor head by way of optic fibers.

Crawford, Thomas M. (Idaho Falls, ID); Davidson, James R. (Idaho Falls, ID); Woods, Gregory K. (Cornelius, OR)

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flame retention head" 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

Acquisition and retention performance of a rapid force production task  

E-Print Network [OSTI]

was designed to investigate (a) concurrent feedback and (b) terminal feedback under acquisition and retention conditions. It was the purpose of Experiment 2 to investigate the influences of (a) blocked presentation of practice trials and (b) random practice... performed five blocks. Subjects from both contexts were divided into concurrent, terminal, or no augmented feedback contexts. In Exper1ment 2, the subjects (N = 64) and the procedures were the same, except subjects were to learn 5 cr1terion forces (75...

Indermill, Catherine

2012-06-07T23:59:59.000Z

222

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

223

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

224

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

225

ADDITIVE TESTING FOR IMPROVED SULFUR RETENTION: PRELIMINARY REPORT  

SciTech Connect (OSTI)

The Savannah River National Laboratory is collaborating with Alfred University to evaluate the potential for additives in borosilicate glass to improve sulfur retention. This preliminary report provides further background on the incorporation of sulfur in glass and outlines the experiments that are being performed by the collaborators. A simulated waste glass composition has been selected for the experimental studies. The first phase of experimental work will evaluate the impacts of BaO, PbO, and V{sub 2}O{sub 5} at concentrations of 1.0, 2.0, and 5.0 wt % on sulfate retention in simulated high level waste borosilicate glass. The second phase of experimental work will evaluate the effects of time at the melt temperature on sulfur retention. The resulting samples will be characterized to determine the amount of sulfur remaining as well as to identify the formation of any crystalline phases. The results will be used to guide the future selection of frits and glass forming chemicals in vitrifying Department of Energy wastes containing high sulfur concentrations.

Amoroso, J.; Fox, K.

2011-09-07T23:59:59.000Z

226

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

227

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

228

Training and Certification of Lock Operators IMTS Heads-up Paper Heads-up Paper  

E-Print Network [OSTI]

Training and Certification of Lock Operators IMTS Heads-up Paper 1 Heads-up Paper Training called "Training and Certification of Lock and Dam Operators." Interested individuals can send ideas of the Training and Certification program. Examples of what will be in those draft documents are as follows

US Army Corps of Engineers

229

Dual, rotating stripper rubber drilling head  

SciTech Connect (OSTI)

In a drilling head for a well bore through which a tool string of varying outside diameter is run, the drilling head sealing against fluid flow past the tool string to divert such fluid through a side outlet port, said drilling head including a housing having an axial passageway through which the tool string is run and a bearing assembly to facilitate rotation of the tool string within the axial passageway, the improved drilling head comprising: first and second stripper rubbers rotatably mounted within the drilling head housing in seating contact with the tool string, said stripper rubbers having substantially identical inner diameters through which the tool string extends, said first stripper rubber formed of an abrasive resistant material to divert fluid flow from the axial passageway of the housing to the side outlet port and said second stripper rubber formed on a sealingly resilient material which maintains sealing contact with the tool string extending there through preventing fluid flow past said tool string; said first stripper rubber being corrected to clamping means associated with the bearing assembly through a first drive ring such that said first stripper rubber rotates with the tool string; and said second stripper rubber is rotatably connected to said clamping means associated with the bearing assembly through a second drive ring, said first and second drive rings coaxially mounted within the housing whereby said first stripper rubber is positioned axially below said second stripper rubber in sealing contact with the tool string.

Bailey, T.F.; Campbell, J.E.

1993-05-25T23:59:59.000Z

230

Rotating head for rotary drilling rigs  

SciTech Connect (OSTI)

A rotating head is claimed for a rotary drilling rig which is to be secured to the top of a well pipe having an inner rotating portion with an opening therethrough which permits passage of drill pipe, pipe joints, and Kelly tools; the rotating portion has an annular drive rubber formed integrally with the top portion thereof. A rotating head drive bushing having an opening with a cross-sectional shape generally conforming to the cross-section of the Kelly tool to permit only sliding motion therebetween is provided with helical external ridges which produce a disengagable gripping action with the opening in the drive rubber at the top of the rotating portion of the rotating head. The rotating portion has a conventional stripper rubber at the bottom thereof and is mounted with a double roller bearing to provide low friction motion with respect to the fixed portion of the head. The double roller bearing is lubricated with a viscous lubricating material and paddles are provided between the sets of rollers of the double roller bearing for distributing the viscous lubricating material and in particular propel it onto the upper set of bearings; the upper body portion of the rotating head is readily detachable from the lower sleeve portion which is normally welded to the well conductor pipe.

Adams, J.R.

1983-09-27T23:59:59.000Z

231

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

232

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

233

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

234

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

235

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

236

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.

237

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

238

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

239

Phosphorus release and retention by soils of natural isolated wetlands  

Science Journals Connector (OSTI)

Hydrological restoration of historically isolated wetlands may mitigate phosphorus (P) loss. The objectives of this study were to quantify P in soil, and to determine the effect of (1) soil characteristics on P release, and (2) antecedent soil hydrological conditions on P dynamics. Humic/fulvic acid bound P and residual P accounted for majority of P (>78%) in surface soils. Soils with highest nutrient status and labile P fractions released most P during initial flooding. Phosphorus dynamics during additional flooding were dependent on soil characteristics, antecedent soil hydrological conditions, and P levels in the water. Phosphorus retention varied between 0.3 and 8 mg m-2 d-1.

E.J. Dunne; K.R. Reddy; M.W. Clark

2006-01-01T23:59:59.000Z

240

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

Note: This page contains sample records for the topic "flame retention head" 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

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

242

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

243

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

244

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

245

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

246

E-Print Network 3.0 - age-dependent skeletal retention Sample...  

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

Riparian Forest Soil Jodi B. Lyons... of nutrients movingfrom the upland areas to aquatic eco- systems (Lowrance, 1991). Nutrient retention varies... is considered to be generally...

247

Superior Long-Term Energy Retention and Volumetric Energy Density for Li-Rich Cathode Materials  

Science Journals Connector (OSTI)

Superior Long-Term Energy Retention and Volumetric Energy Density for Li-Rich Cathode Materials ... †Department of Energy Engineering, School of

Pilgun Oh; Seungjun Myeong; Woongrae Cho; Min-Joon Lee; Minseong Ko; Hu Young Jeong; Jaephil Cho

2014-09-02T23:59:59.000Z

248

E-Print Network 3.0 - alliance rubiaceae retention Sample Search...  

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: alliance rubiaceae retention Page: << < 1 2 3 4 5 > >> 1 Razafimandimbison & al. A basal grade...

249

The Head-Neck Sensory Motor System  

E-Print Network [OSTI]

The Head-Neck Sensory Motor System Edited by Alain Berthoz Laboratoire de Physiologie, sideslip, and thrust) determine its loca- tion in space, and rotations (yaw, pitch, and roll) change its, no functional significance can be attributed to this multiple sampling. Oculomotor System of Calliphora

250

Department Heads Meeting D. MacFarlane  

E-Print Network [OSTI]

Department Heads Meeting D. MacFarlane March 21, 2013 #12;Snowmass working groups Snowmass web-7 at SLAC Energy Frontier All Hands: » April 3-6 at Brookhaven (web site) » June 30-July 3 at U. Washington a world leading cosmic frontier program » Cosmology, cosmic ray, dark matter & dark energy emphasis

Wechsler, Risa H.

251

Employee Handbook & Policy Manual Section Heading  

E-Print Network [OSTI]

Employee Handbook & Policy Manual Section Heading: 2.00 ­ Administrative & Personnel Policies in this document: · Person With Disabilities: a person having a physical or mental impairment which substantially. A "common wheelchair" does not exceed 30 inches in width and 48 inches in length measured two inches from

252

Judith Sheine Professor and Department Head  

E-Print Network [OSTI]

of Environmental Design, Department of Architecture Chair, 2002- present Professor, 2002 - present; AssociateJudith Sheine Professor and Department Head Department of Architecture School of Architecture) 346-3626 e-mail: jesheine@uoregon.edu Education 1979 Princeton University, School of Architecture

253

Analog VLSI Architecture for Computing Heading Direction  

E-Print Network [OSTI]

arrays of elementary velocity sensors to estimate the direction of heading for pure translational motion implementa- tion and the functionality of the elementary motion sensors used to extract the optical ow eld systems place severe constraints on their size, power consumption, shock resistance and manufacturing cost

254

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

255

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

256

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

257

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

258

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

259

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

260

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

Note: This page contains sample records for the topic "flame retention head" 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

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

262

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

263

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.

264

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

265

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

266

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

267

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.

268

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

269

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

270

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

271

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.

272

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

273

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

274

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

275

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

276

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

277

3D head anthropometric analysis Reyes Enciso*ab  

E-Print Network [OSTI]

a current three-dimensional image-based face modeling technique using a plaster head model. We will also. In this paper we acquired and validated 3-dimensional images of a plaster head using structured-light image

Shahabi, Cyrus

278

Type B Accident Investigation Board Report on the Head Injury...  

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

on the Head Injury to a Miner at the Waste Isolation Pilot Plant, Carlsbad, New Mexico - August 25, 2004 Type B Accident Investigation Board Report on the Head Injury to a Miner at...

279

Anterior endoderm and head induction in early vertebrate embryos  

Science Journals Connector (OSTI)

Early work on the formation of the vertebrate body axis indicated the existence of separate head- and trunk-inducing regions in Spemann's organizer of the amphibian gastrula. In mammals some head-organizing a...

Flávio S. J. de Souza; Christof Niehrs

2000-05-01T23:59:59.000Z

280

A 3-D display head-set for personalized computing  

E-Print Network [OSTI]

This thesis covers the design and implementation of a binocular display head-set akin to Dr . Ivan E. Sutherland's head-mounted display, but using several new technologies and new techniques in computer graphics: small ...

Callahan, Mark A

1983-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flame retention head" 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

1 INTRODUCTION High-head storage hydropower plants operate  

E-Print Network [OSTI]

1 INTRODUCTION High-head storage hydropower plants operate their turbines during periods of high Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland ABSTRACT: High-head storage hydropower plants

Floreano, Dario

282

Gas cushion control of OVJP print head position  

DOE Patents [OSTI]

An OVJP apparatus and method for applying organic vapor or other flowable material to a substrate using a printing head mechanism in which the print head spacing from the substrate is controllable using a cushion of air or other gas applied between the print head and substrate. The print head is mounted for translational movement towards and away from the substrate and is biased toward the substrate by springs or other means. A gas cushion feed assembly supplies a gas under pressure between the print head and substrate which opposes the biasing of the print head toward the substrate so as to form a space between the print head and substrate. By controlling the pressure of gas supplied, the print head separation from the substrate can be precisely controlled.

Forrest, Stephen R

2014-10-07T23:59:59.000Z

283

Magnetic Field based Heading Estimation for Pedestrian Navigation Environments  

E-Print Network [OSTI]

Magnetic Field based Heading Estimation for Pedestrian Navigation Environments Muhammad Haris Afzal held devices, these other sources are accelerometers for roll and pitch estimates and magnetic field sensors for the heading. In order to utilize the magnetic field sensors for heading estimation

Calgary, University of

284

Automatic Tissue Classification for the Human Head from Multispectral MRI  

E-Print Network [OSTI]

1 Automatic Tissue Classification for the Human Head from Multispectral MRI Tolga Tasdizen, David for classifying multispectral MR scans of the human head into nine tissue classes. User initialization is adopted. #12;Chapter 1 Introduction Classification of head magnetic resonance imaging (MRI) data

Utah, University of

285

Oculomotor Responses to Active Head Movements in Darkness  

E-Print Network [OSTI]

information on head rotation from the vestibular system to the saccade-generating mechanism in the brain stem482 Oculomotor Responses to Active Head Movements in Darkness Formulation and Testing Sistemistica, Università di Pavia, Pavia, Italy Passive head rotation in darkness produces vestibular nystagmus

Ramat, Stefano

286

Use of rare earth elements as external markers for mean retention time measurements in ruminants  

E-Print Network [OSTI]

Review Use of rare earth elements as external markers for mean retention time measurements -- The present review deals with the utilisation of rare earth (RE) elements as particulate markers for ruminant earth / retention time / feedstuff / methodology / ruminant Résumé -- Utilisation des terres rares comme

Paris-Sud XI, Université de

287

A LANDSCAPE SCALE EVALUATION OF PHOSPHORUS RETENTION IN WETLANDS OF THE  

E-Print Network [OSTI]

217 A LANDSCAPE SCALE EVALUATION OF PHOSPHORUS RETENTION IN WETLANDS OF THE LAPLATTE RIVER BASIN approach to examine phosphorus retention in wetlands of the LaPlatte River basin (13,723 ha), Vermont information system. Most wetland variables had significant (p

Wang, Deane

288

RETENTION OF SULFATE IN HIGH LEVEL RADIOACTIVE WASTE GLASS  

SciTech Connect (OSTI)

High level radioactive wastes are being vitrified at the Savannah River Site for long term disposal. Many of the wastes contain sulfate at concentrations that can be difficult to retain in borosilicate glass. This study involves efforts to optimize the composition of a glass frit for combination with the waste to improve sulfate retention while meeting other process and product performance constraints. The fabrication and characterization of several series of simulated waste glasses are described. The experiments are detailed chronologically, to provide insight into part of the engineering studies used in developing frit compositions for an operating high level waste vitrification facility. The results lead to the recommendation of a specific frit composition and a concentration limit for sulfate in the glass for the next batch of sludge to be processed at Savannah River.

Fox, K.

2010-09-07T23:59:59.000Z

289

MEMORANDUM FOR HEADS OF DEPARTMENTAL ELEMENTS FROM:  

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

HEADS OF DEPARTMENTAL ELEMENTS HEADS OF DEPARTMENTAL ELEMENTS FROM: SUBJECT: Project Full Funding Policy in the Annual ~ u d ~ e t Request On July 18,2008, the Secretary approved the Department's Contract and Project Management Root Cause Analysis (RCA) Corrective Action Plan (CAP). This is the Department's plan to improve contract and project management and ultimately be removed from GAO's High Risk List - a list that the Department has been on since 1990. One of the key issues identified in the CAP is the Department's failure to request and obtain full funding for non-information technology capital asset projects, where appropriate. This new policy is established to reduce the inherent inefficiencies and risks ingoduced by prolonging the duration of small projects, as well as to add budget stability

290

Head erosion with emittance growth in PWFA  

SciTech Connect (OSTI)

Head erosion is one of the limiting factors in plasma wakefield acceleration (PWFA). We present a study of head erosion with emittance growth in field-ionized plasma from the PWFA experiments performed at the FACET user facility at SLAC. At FACET, a 20.3 GeV bunch with 1.8 Multiplication-Sign 10{sup 10} electrons is optimized in beam transverse size and combined with a high density lithium plasma for beam-driven plasma wakefield acceleration experiments. A target foil is inserted upstream of the plasma source to increase the bunch emittance through multiple scattering. Its effect on beamplasma interaction is observed with an energy spectrometer after a vertical bend magnet. Results from the first experiments show that increasing the emittance has suppressed vapor field-ionization and plasma wakefields excitation. Plans for the future are presented.

Li, S. Z.; Adli, E.; England, R. J.; Frederico, J.; Gessner, S. J.; Hogan, M. J.; Litos, M. D.; Walz, D. R.; Muggli, P.; An, W.; Clayton, C. E.; Joshi, C.; Lu, W.; Marsh, K. A.; Mori, W.; Vafaei, N. [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States) and SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States) and University of Oslo, Oslo, N-0316 (Norway) and SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Max Planck Institute for Physics, Munich (Germany); University of California, Los Angeles, CA 90095 (United States)

2012-12-21T23:59:59.000Z

291

Surface treatment of magnetic recording heads  

DOE Patents [OSTI]

Surface modification of magnetic recording heads using plasma immersion ion implantation and deposition is disclosed. This method may be carried out using a vacuum arc deposition system with a metallic or carbon cathode. By operating a plasma gun in a long-pulse mode and biasing the substrate holder with short pulses of a high negative voltage, direct ion implantation, recoil implantation, and surface deposition are combined to modify the near-surface regions of the head or substrate in processing times which may be less than 5 min. The modified regions are atomically mixed into the substrate. This surface modification improves the surface smoothness and hardness and enhances the tribological characteristics under conditions of contact-start-stop and continuous sliding. These results are obtained while maintaining original tolerances.

Komvopoulos, Kyriakos (Orinda, CA); Brown, Ian G. (Berkeley, CA); Wei, Bo (Albany, CA); Anders, Simone (Albany, CA); Anders, Andre (Albany, CA); Bhatia, C. Singh (Morgan Hill, CA)

1998-01-01T23:59:59.000Z

292

Surface treatment of magnetic recording heads  

DOE Patents [OSTI]

Surface modification of magnetic recording heads using plasma immersion ion implantation and deposition is disclosed. This method may be carried out using a vacuum arc deposition system with a metallic or carbon cathode. By operating a plasma gun in a long-pulse mode and biasing the substrate holder with short pulses of a high negative voltage, direct ion implantation, recoil implantation, and surface deposition are combined to modify the near-surface regions of the head or substrate in processing times which may be less than 5 min. The modified regions are atomically mixed into the substrate. This surface modification improves the surface smoothness and hardness and enhances the tribological characteristics under conditions of contact-start-stop and continuous sliding. These results are obtained while maintaining original tolerances.

Komvopoulos, Kyriakos (Orinda, CA); Brown, Ian G. (Berkeley, CA); Wei, Bo (Albany, CA); Anders, Simone (Albany, CA); Anders, Andre (Albany, CA); Bhatia, Singh C. (Morgan Hill, CA)

1995-01-01T23:59:59.000Z

293

Surface treatment of magnetic recording heads  

DOE Patents [OSTI]

Surface modification of magnetic recording heads using plasma immersion ion implantation and deposition is disclosed. This method may be carried out using a vacuum arc deposition system with a metallic or carbon cathode. By operating a plasma gun in a long-pulse mode and biasing the substrate holder with short pulses of a high negative voltage, direct ion implantation, recoil implantation, and surface deposition are combined to modify the near-surface regions of the head or substrate in processing times which may be less than 5 min. The modified regions are atomically mixed into the substrate. This surface modification improves the surface smoothness and hardness and enhances the tribological characteristics under conditions of contact-start-stop and continuous sliding. These results are obtained while maintaining original tolerances. 22 figs.

Komvopoulos, K.; Brown, I.G.; Wei, B.; Anders, S.; Anders, A.; Bhatia, C.S.

1998-11-17T23:59:59.000Z

294

Surface treatment of magnetic recording heads  

DOE Patents [OSTI]

Surface modification of magnetic recording heads using plasma immersion ion implantation and deposition is disclosed. This method may be carried out using a vacuum arc deposition system with a metallic or carbon cathode. By operating a plasma gun in a long-pulse mode and biasing the substrate holder with short pulses of a high negative voltage, direct ion implantation, recoil implantation, and surface deposition are combined to modify the near-surface regions of the head or substrate in processing times which may be less than 5 min. The modified regions are atomically mixed into the substrate. This surface modification improves the surface smoothness and hardness and enhances the tribological characteristics under conditions of contact-start-stop and continuous sliding. These results are obtained while maintaining original tolerances. 15 figs.

Komvopoulos, K.; Brown, I.G.; Wei, B.; Anders, S.; Anders, A.; Bhatia, S.C.

1995-12-19T23:59:59.000Z

295

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

296

Definition: Head-End System | Open Energy Information  

Open Energy Info (EERE)

Head-End System Head-End System Jump to: navigation, search Dictionary.png Head-End System A head-end system is hardware and software that receives the stream of meter data brought back to the utility through the AMI. Head-end systems may perform a limited amount of data validation before either making the data available for other systems to request or pushing the data out to other systems.[1] Related Terms advanced metering infrastructure, system References ↑ https://www.smartgrid.gov/category/technology/head_end_system [[Ca LikeLike UnlikeLike You and one other like this.One person likes this. Sign Up to see what your friends like. tegory: Smart Grid Definitionssmart grid,smart grid, |Template:BASEPAGENAME]]smart grid,smart grid, Retrieved from "http://en.openei.org/w/index.php?title=Definition:Head-End_System&oldid=502621"

297

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

298

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

299

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

300

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

Note: This page contains sample records for the topic "flame retention head" 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

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

302

Integrated head package for top mounted nuclear instrumentation  

DOE Patents [OSTI]

A nuclear reactor such as a pressurized water reactor has an integrated head package providing structural support and increasing shielding leading toward the vessel head. A reactor vessel head engages the reactor vessel, and a control rod guide mechanism over the vessel head raises and lowers control rods in certain of the thimble tubes, traversing penetrations in the reactor vessel head, and being coupled to the control rods. An instrumentation tube structure includes instrumentation tubes with sensors movable into certain thimble tubes disposed in the fuel assemblies. Couplings for the sensors also traverse penetrations in the reactor vessel head. A shroud is attached over the reactor vessel head and encloses the control rod guide mechanism and at least a portion of the instrumentation tubes when retracted. The shroud forms a structural element of sufficient strength to support the vessel head, the control rod guide mechanism and the instrumentation tube structure, and includes radiation shielding material for limiting passage of radiation from retracted instrumentation tubes. The shroud is thicker at the bottom adjacent the vessel head, where the more irradiated lower ends of retracted sensors reside. The vessel head, shroud and contents thus can be removed from the reactor as a unit and rested safely and securely on a support.

Malandra, Louis J. (McKeesport, PA); Hornak, Leonard P. (Forest Hills, PA); Meuschke, Robert E. (Monroeville, PA)

1993-01-01T23:59:59.000Z

303

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

304

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

305

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

306

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

307

Heathrow campaigners – heading for a historic victory?  

Science Journals Connector (OSTI)

The article assesses the reasons why the government may be heading for a historic defeat over its plans to expand Heathrow. It shows how the people and organisations campaigning to stop the expansion learnt vital lessons from past defeats. It highlights three key tactics the campaigners have used: building a wide-ranging coalition encompassing such diverse groups as local authorities and direct action activists, running a high-profile, pro-active, agenda-setting campaign and a willingness to challenge the government's economic arguments. The campaign is set against a background of peak oil, a deep economic recession and the threat of climate change.

John Stewart

2009-01-01T23:59:59.000Z

308

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

309

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

310

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

311

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

312

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

313

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

314

Increased intrapulmonary retention of radiolabeled neutrophils in early oxygen toxicity  

SciTech Connect (OSTI)

Sequential lung injuries, such as oxygen toxicity followed by septicemia, are common during the adult respiratory distress syndrome (ARDS). As these forms of vascular injury may be mediated in part by polymorphonuclear leukocytes (PMN), aberrant interactions between PMN and previously injured pulmonary endothelium are of both theoretical interest and clinical importance. The present study was undertaken to test the hypothesis that early oxygen toxicity at a dose that injuries pulmonary endothelium relatively selectively alters intrapulmonary neutrophil kinetics. Unanesthetized rats breathing 1.0 atmospheres oxygen for 36 h showed ultrastructural endothelial damage but no edema, injury, or neutrophilic inflammation by histologic criteria. However, in these oxygen-toxic animals, whereas initial accumulation of radiolabeled PMN in lungs was normal, washout of PMN was abnormal at 120 min after infusion, at which point the pulmonary retention of radiolabeled PMN in the lungs of oxygen-treated animals was significantly higher than in control animals (139% of control, p less than 0.0096). Features of our methodology, including avoidance of osmotic stress and use of paired control animals, appear to have greatly enhanced the sensitivity of radiolabeled neutrophils for detecting a subtle abnormality of neutrophil-endothelial interactions. Our studies in the oxygen toxicity model provide the first demonstration in vivo of abnormal intrapulmonary neutrophil kinetics in early oxygen toxicity prior to the onset of histologic evidence of lung injury or inflammation.

Rinaldo, J.E.; English, D.; Levine, J.; Stiller, R.; Henson, J.

1988-02-01T23:59:59.000Z

315

Formation and retention of methane in coal. Final report  

SciTech Connect (OSTI)

The formation and retention of methane in coalbeds was studied for ten Utah coal samples, one Colorado coal sample and eight coal samples from the Argonne Premium Coal Sample Bank.Methane gas content of the Utah and Colorado coals varied from zero to 9 cm{sup 3}/g. The Utah coals were all high volatile bituminous coals. The Colorado coal was a gassy medium volatile bituminous coal. The Argonne coals cover a range or rank from lignite to low volatile bituminous coal and were used to determine the effect of rank in laboratory studies. The methane content of six selected Utah coal seams and the Colorado coal seam was measured in situ using a special sample collection device and a bubble desorbometer. Coal samples were collected at each measurement site for laboratory analysis. The cleat and joint system was evaluated for the coal and surrounding rocks and geological conditions were noted. Permeability measurements were performed on selected samples and all samples were analyzed for proximate and ultimate analysis, petrographic analysis, {sup 13}C NMR dipolar-dephasing spectroscopy, and density analysis. The observed methane adsorption behavior was correlated with the chemical structure and physical properties of the coals.

Hucka, V.J.; Bodily, D.M.; Huang, H.

1992-05-15T23:59:59.000Z

316

Onderwerpscodes Chemie -Farmacie / Subject headings Chemistry -Pharmacy, 2009, April1 Rubrieken Chemie -Farmacie: Subject headings Chemistry -  

E-Print Network [OSTI]

chemie 07 Inorganic chemistry 11.14 - 08 Organische chemie 08 Organic chemistry 12.11 - 10 Didactics and priciples of chemistry 14.03 - 16 Vervolgwerken - Annuals 16 Book series and annuals 14Onderwerpscodes Chemie - Farmacie / Subject headings Chemistry - Pharmacy, 2009, April1 Rubrieken

Galis, Frietson

317

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

318

Employee Retention and Integrated Disability Management Practices as Demand Side Factors  

Science Journals Connector (OSTI)

Introduction Demand-side employment research on company policies and practices related to retention and absence and disability management (ADM) can contribute to our understanding...Aim To examin...

Rochelle Habeck; Allan Hunt; Colleen Head Rachel…

2010-12-01T23:59:59.000Z

319

Shale-Gas Permeability and Diffusivity Inferred by Improved Formulation of Relevant Retention and Transport Mechanisms  

Science Journals Connector (OSTI)

A theoretically improved model incorporating the relevant mechanisms of gas retention and transport in gas-bearing shale formations is presented for determination of intrinsic gas permeability and diffusivity. Th...

Faruk Civan; Chandra S. Rai; Carl H. Sondergeld

2011-02-01T23:59:59.000Z

320

Absorption and retention of different chemical forms of trace minerals by mature horses  

E-Print Network [OSTI]

This study was undertaken to compare the absorption and retention of copper, manganese and zinc when supplemented to the diet in the form of oxide, sulfate or organic-chelate mineral supplements. Six mature Miniature Horses were used in a...

Wagner, Elizabeth Lynn

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "flame retention head" 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

Memorandum to Heads of Federal Departments and Agencies Regarding Pollution  

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

Memorandum to Heads of Federal Departments and Agencies Regarding Memorandum to Heads of Federal Departments and Agencies Regarding Pollution Prevention and the National Environmental Policy Act Memorandum to Heads of Federal Departments and Agencies Regarding Pollution Prevention and the National Environmental Policy Act This memorandum provides guidance to the federal agencies on incorporating pollution prevention principles, techniques, and mechanisms into their planning and decisionmaking processes and evaluating and reporting those efforts in documents prepared pursuant to the National Environmental Policy Act. Memorandum to Heads of Federal Departments and Agencies Regarding Pollution Prevention and the National Environmental Policy Act More Documents & Publications Integrating Pollution Prevention with NEPA Planning Activities

322

Meyer-Harms, Bettina, Xabier Irigoien, Robert Head, and Roger ...  

Science Journals Connector (OSTI)

M. Head and Harris (1994) first used this method to describe selective feeding by different size-fractionated zooplankton off the coast of Morocco. A modification ...

1999-03-11T23:59:59.000Z

323

Bret Knapp to head combined Weapons Engineering, Weapons Physics...  

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

Weapons Engineering, Weapons Physics Directorates Bret Knapp to head combined Weapons Engineering, Weapons Physics Directorates at Los Alamos National Laboratory New leadership...

324

Council on Environmental Quality - Memorandum for Heads of Federal...  

Open Energy Info (EERE)

search OpenEI Reference LibraryAdd to library Memorandum: Council on Environmental Quality - Memorandum for Heads of Federal Departments and Agencies Abstract This page links...

325

TO: Procurement Directors Head of Contracting Activities FROM...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

8 DATE: December 5, 2014 TO: Procurement Directors Head of Contracting Activities FROM: Director Contract and Financial Assistance Policy Division Office of Policy Office of...

326

TO: Procurement Directors Head of Contracting Activities FROM...  

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

9 DATE: August 21, 2014 TO: Procurement Directors Head of Contracting Activities FROM: Director Contract and Financial Assistance Policy Division Office of Policy Office of...

327

Laboratory Demonstration of a New American Low-Head Hydropower...  

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

Laboratory Demonstration of a New American Low-Head Hydropower Turbine 68bhydrogreensmallhydroch11.ppt More Documents & Publications Real World Demonstration of a New...

328

Dr. Jim Wright Acting Head, Division of Radiation Oncology  

E-Print Network [OSTI]

Dr. Jim Wright Acting Head, Division of Radiation Oncology Associate Professor Department outstanding contributions to the care and treatment of cancer patients through research. Dr. Jim Wright has

Haykin, Simon

329

Nanoscale retention-loss dynamics of polycrystalline PbTiO{sub 3} nanotubes.  

SciTech Connect (OSTI)

We observed the nanoscale retention dynamics of polycrystalline PbTiO{sub 3} nanotubes using piezoresponse force microscopy. We found that the retention loss of the nanodot domains on the nanotubes showed the stretched exponential relaxation behaviors with stretched exponential factor n being less than 1 (0.523 and 0.692), which are similar to the thin films. In addition, the nanodot domains showed a diverse relaxation time constant {tau} due to different remnant polarization of each dot domains.

Choi, H.; Kim, Y.; Hong, S.; Sung, T.-H.; Shin, H.; No, K. (Materials Science Division); (Korea Advanced Inst. of Science and Technology); (Hanyang Univ.); (Kookmin Univ.)

2011-07-01T23:59:59.000Z

330

Estimation of heterosis and heterosis retention in the development of a synthetic breed of goat  

E-Print Network [OSTI]

ESTIMATION OF HETEROSIS AND HETEROSIS RETENTION IN THE DEVELOPMENT OF A SYNTHETIC BREED OF GOAT A Thesis by MATTHEW BLAIN JONES Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE May 1994 Major Subject Animal Breeding ESTIMATION OF HETEROSIS AND HETEROSIS RETENTION IN THE DEVELOPMENT OF A SYNTHETIC BREED OF GOAT A Thesis by MATTHEW BLAIN JONES Submitted to Texas A&M University in partial...

Jones, Matthew Blain

2012-06-07T23:59:59.000Z

331

Behavior of deuterium retention and surface morphology for VPS–W/F82H  

SciTech Connect (OSTI)

The deuterium (D) retention for Vacuum Plasma Spray (VPS)–tungsten (W)/F82H was studied using two different implantation methods, namely D plasma exposure and View the MathML source implantation. The D retention for polished VPS–W/F82H after plasma exposure was found to be reduced compared to that for polycrystalline tungsten. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations indicated that porous structures around grain boundaries and the interface between VPS–W layers would be potential D diffusion paths, leading to low D retention. In the case of View the MathML source implantation, the shape of D2 TDS spectrum was almost the same as that for D plasma-exposed VPS–W/F82H; however, the D retention was quite high for unpolished VPS–W/F82H, indicating that most of D was trapped by the oxide layer, which was produced by the VPS process. The reduction of surface area due to the polishing process also reduces D retention for VPS–W/F82H. These results indicate that controlling the surface chemical states is important for the reduction of tritium retention for future fusion reactors.

Yasuhisa Oya; Masashi Shimada; Tomonori Tokunaga; Hideo Watanabe; Naoaki Yoshida; Yuji Hatano; Ryuta Kasada; Takuya Nagasaka; Akihiko Kimura; Kenji Okuno

2013-11-01T23:59:59.000Z

332

Mars mission laser tool heads to JPL  

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

Mars mission laser tool Mars mission laser tool Mars mission laser tool heads to JPL Curiosity will carry the newly delivered laser instrument to reveal which elements are present in Mars' rocks and soils. September 21, 2010 A bright ball of plasma is produced by ChemCam's invisible laser beam striking a rock within the Mars sample chamber. A bright ball of plasma is produced by ChemCam's invisible laser beam striking a rock within the Mars sample chamber. Contact Nancy Ambrosiano Communications Office (505) 667-0471 Email "ChemCam will act as a geochemical observatory, providing composition data to understand if Mars was, is, or will be a habitable world." Star Wars photon gun will give Mars rover hands-free rock ID LOS ALAMOS, New Mexico, September 21, 2010-The ChemCam instrument has

333

Light water reactor lower head failure analysis  

SciTech Connect (OSTI)

This document presents the results from a US Nuclear Regulatory Commission-sponsored research program to investigate the mode and timing of vessel lower head failure. Major objectives of the analysis were to identify plausible failure mechanisms and to develop a method for determining which failure mode would occur first in different light water reactor designs and accident conditions. Failure mechanisms, such as tube ejection, tube rupture, global vessel failure, and localized vessel creep rupture, were studied. Newly developed models and existing models were applied to predict which failure mechanism would occur first in various severe accident scenarios. So that a broader range of conditions could be considered simultaneously, calculations relied heavily on models with closed-form or simplified numerical solution techniques. Finite element techniques-were employed for analytical model verification and examining more detailed phenomena. High-temperature creep and tensile data were obtained for predicting vessel and penetration structural response.

Rempe, J.L.; Chavez, S.A.; Thinnes, G.L. [EG and G Idaho, Inc., Idaho Falls, ID (United States)] [and others

1993-10-01T23:59:59.000Z

334

Topic Models to Interpret MeSH MEDLINE's Medical Subject Headings  

E-Print Network [OSTI]

://ii.nlm.nih.gov/mti.shtml #12;MeSH heading Major MeSH heading Major qualifier MeSH-qualifier combination Humans Brain metabolism Brain (metabolism) Table 1. Most frequent MeSH headings, major MeSH headings, major qualifiers and MeTopic Models to Interpret MeSH � MEDLINE's Medical Subject Headings David Newman12 , Sarvnaz Karimi

Newman, David

335

MFRSR Head Refurbishment, Data Logger Upgrade and Calibration Improvements  

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

MFRSR Head Refurbishment, Data Logger Upgrade MFRSR Head Refurbishment, Data Logger Upgrade and Calibration Improvements Gary Hodges, CIRES/NOAA and John Schmelzer, PNL gary.hodges@noaa.gov, john.schmelzer@pnl.gov 17th Annual ARM Science Team Meeting 26-30 March 2006 Monterey, CA Head Refurbishment The Process Includes: * New filter detectors * Relocate internal thermistors * New connectors * Gain resistors moved to head * Improved insulation The Finished Heads: * Are lamp calibrated * Have filter profiles measured * Cosine characterized * Are out-of-band tested What Does This Mean For Data Users? * Fewer data gaps * Fewer DQRs * Confidence in the data * Well calibrated data Calibration Improvements 5 6 7 8 0 2 4 6 Airmass ln Direct Data will now be calibrated by the Langley method Extrapolate to TOA to get V 0 Benefits of Langley vs. Lamp calibrations:

336

Tracking Santa: An Interview with the Head Researcher | Department of  

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

Tracking Santa: An Interview with the Head Researcher Tracking Santa: An Interview with the Head Researcher Tracking Santa: An Interview with the Head Researcher December 23, 2010 - 11:12am Addthis Tracking Santa: An Interview with the Head Researcher Ginny Simmons Ginny Simmons Former Managing Editor for Energy.gov, Office of Public Affairs What does this mean for me? You'll be able to start monitoring St. Nick's journey starting at 6 AM ET on Christmas Eve. Every year since 1998, the Department of Energy's Los Alamos lab has been using state of the art technology to track Santa Claus as he circles the globe the night before Christmas. You'll be able to start monitoring St. Nick's journey here starting at 6 AM ET on Christmas Eve. This week, I got a chance to talk to Santa Tracker Head Researcher (and Cibola Flight Experiment Project Leader) Diane Roussel-Dupre to get a

337

Effect of graded hypoxia on retention of technetium-99m-nitroheterocycle in perfused rat heart  

SciTech Connect (OSTI)

The purpose of this investigation was to determine the effects of graded hypoxia on the retention of a {sup 99m}Tc-labeled nitroimidazole. Rat hearts were perfused retrogradely with Krebs-Henseleit buffer at 37{degrees}C and paced at 5 Hz. After a 20-min stabilization period, coronary flow was maintained at 8 ml/min/g wet wt and the hearts were perfused with media equilibrated with gas mixtures containing 5% CO{sub 2} and various levels of O{sub 2}, from 544 to 29 Torr. Technetium-99m-O(PnAO-1-(2-nitroimidazole)), BMS-181321, was infused for 20 min into a side port of the aortic cannula. Perfusion continued for an additional 40 min to allow for compound clearance. Each decrease of perfusate PO{sub 2} brought about an increase in the retention of BMS-181321, resulting in a good correlation between its retention and perfusate PO{sub 2} (r=0.97). Myocardial oxygen consumption was independent of oxygen delivery when the perfusate oxygen pressure was greater than 350 Torr. Below this value, oxygen consumption declined markedly as influent PO{sub 2}. A good correlation was obtained between retention of the nitroheterocycle and the cytosolic lactate/pyruvate ratio (r=0.98). When glucose was omitted from the perfusate (PO{sub 2}=27 Torr), retention of the nitroheterocycle was increased by about 25% as compared to hearts perfused in the presence of this substrate. These results indicate that myocardial retention of BMS-181321 is coupled to the level of tissue oxygenation and that hypoxic retention may be affected by substrate input. 24 refs., 3 figs., 1 tab.

Rumsey, W.L.; Patel, B.; Linder, K.E. [Bristol-Myers Squibb Pharmaceutical Research Inst., Princeton, NJ (United States)

1995-04-01T23:59:59.000Z

338

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.

339

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

340

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

Note: This page contains sample records for the topic "flame retention head" 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

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

342

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

343

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

344

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

345

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

346

Design of a dual stage actuator tape head with high-bandwidth track following capability  

E-Print Network [OSTI]

to the voice coil motor (VCM). A leaf spring on top of thespring Slot Air bearing surface Read/write elements (in slot) Bracket (b) Servo head Read head Write head Voice coil

Raeymaekers, Bart; Graham, Matthew R.; Callafon, Raymond A.; Talke, Frank E.

2009-01-01T23:59:59.000Z

347

Intraosseous Venography with Carbon Dioxide in Percutaneous Vertebroplasty: Carbon Dioxide Retention in Renal Veins  

SciTech Connect (OSTI)

The objective of the present study was to determine the frequency of gas retention in the renal vein following carbon dioxide intraosseous venography in the prone position and, while citing references, to examine its onset mechanisms. All percutaneous vertebroplasties performed at our hospital from January to December 2005 were registered and retrospectively analyzed. Of 43 registered procedures treating 79 vertebrae, 28 procedures treating 54 vertebrae were analyzed. Vertebral intraosseous venography was performed using carbon dioxide as a contrast agent in all percutaneous vertebroplasty procedures. In preoperative and postoperative vertebral CT, gas retention in the renal vein and other areas was assessed. Preoperative CT did not show gas retention (0/28 procedures; 0%). Postoperative CT confirmed gas retention in the renal vein in 10 of the 28 procedures (35.7%). Gas retention was seen in the right renal vein in 8 procedures (28.6%), in the left renal vein in 5 procedures (17.9%), in the left and right renal veins in 3 procedures (10.7%), in vertebrae in 22 procedures (78.6%), in the soft tissue around vertebrae in 14 procedures (50.0%), in the spinal canal in 12 procedures (42.9%), and in the subcutaneous tissue in 5 procedures (17.9%). In conclusion, in our study, carbon dioxide gas injected into the vertebra frequently reached and remained in the renal vein.

Komemushi, Atsushi, E-mail: kome64@yo.rim.or.jp; Tanigawa, Noboru; Kariya, Shuji; Kojima, Hiroyuki; Shomura, Yuzo; Tokuda, Takanori; Nomura, Motoo; Terada, Jiro; Kamata, Minoru; Sawada, Satoshi [Kansai Medical University, Department of Radiology (Japan)

2008-11-15T23:59:59.000Z

348

Multiresponse multilayer vadose zone model calibration using Markov chain Monte Carlo simulation and field water retention data  

E-Print Network [OSTI]

and field water retention data Thomas Wöhling1,2 and Jasper A. Vrugt3,4,5 Received 4 March 2010; revised 14

Vrugt, Jasper A.

349

High energy activation data library (HEAD-2009)  

SciTech Connect (OSTI)

A proton activation data library for 682 nuclides from 1 H to 210Po in the energy range from 150 MeV up to 1 GeV was developed. To calculate proton activation data, the MCNPX 2.6.0 and CASCADE/INPE codes were chosen. Different intranuclear cascade, preequilibrium, and equilibrium nuclear reaction models and their combinations were used. The optimum calculation models have been chosen on the basis of statistical correlations for calculated and experimental proton data taken from the EXFOR library of experimental nuclear data. All the data are written in ENDF-6 format. The library is called HEPAD-2008 (High-Energy Proton Activation Data). A revision of IEAF-2005 neutron activation data library has been performed. A set of nuclides for which the cross-section data can be (and were) updated using more modern and improved models is specified, and the corresponding calculations have been made in the present work. The new version of the library is called IEAF-2009. The HEPAD-2008 and IEAF-2009 are merged to the final HEAD-2009 library.

Mashnik, Stepan G [Los Alamos National Laboratory; Korovin, Yury A [NON LANL; Natalenko, Anatoly A [NON LANL; Konobeyev, Alexander Yu [NON LANL; Stankovskiy, A Yu [NON LANL

2010-01-01T23:59:59.000Z

350

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

351

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

352

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

353

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

354

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

355

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

356

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

357

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

358

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

359

Memorandum for Heads of Federal Departments and Agencies: Emergencies and  

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

Heads of Federal Departments and Agencies: Heads of Federal Departments and Agencies: Emergencies and NEPA Memorandum for Heads of Federal Departments and Agencies: Emergencies and NEPA With this Memorandum, the Council on Environmental Quality reiterates its previous guidance on the National Environmental Policy Act (NEPA) environmental review of proposed emergency response actions.This memorandum clarifies that the previous guidance remains applicable to current situations and provides guidance on required agency environmental review. Emergencies and NEPA More Documents & Publications Memorandum for Federal NEPA Contacts: Emergency Actions and NEPA Aligning National Environmental Policy Act Process with Environmental Management Systems Final Guidance on Improving the Process for Preparing Efficient and Timely

360

Head of EM Visits Waste Isolation Pilot Plant for First Underground...  

Office of Environmental Management (EM)

Head of EM Visits Waste Isolation Pilot Plant for First Underground Tour Since February Incidents Head of EM Visits Waste Isolation Pilot Plant for First Underground Tour Since...

Note: This page contains sample records for the topic "flame retention head" 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

Competing retention pathways of uranium upon reaction with Fe(II)  

SciTech Connect (OSTI)

Biogeochemical retention processes, including adsorption, reductive precipitation, and incorporation into host minerals, are important in contaminant transport, remediation, and geologic deposition of uranium. Recent work has shown that U can become incorporated into iron (hydr)oxide minerals, with a key pathway arising from Fe(II)-induced transformation of ferrihydrite, (Fe(OH)3•nH2O) to goethite (?-FeO(OH)); this is a possible U retention mechanism in soils and sediments. Several key questions, however, remain unanswered regarding U incorporation into iron (hydr)oxides and this pathway’s contribution to U retention, including: (i) the competitiveness of U incorporation versus reduction to U(IV) and subsequent precipitation of UO2; (ii) the oxidation state of incorporated U; (iii) the effects of uranyl aqueous speciation on U incorporation; and, (iv) the mechanism of U incorporation. Here we use a series of batch reactions conducted at pH ~7, [U(VI)] from 1 to 170 ?M, [Fe(II)] from 0 to 3 mM, and [Ca] at 0 or 4 mM) coupled with spectroscopic examination of reaction products of Fe(II)-induced ferrihydrite transformation to address these outstanding questions. Uranium retention pathways were identified and quantified using extended x-ray absorption fine structure (EXAFS) spectroscopy, x-ray powder diffraction, x-ray photoelectron spectroscopy, and transmission electron microscopy. Analysis of EXAFS spectra showed that 14 to 89% of total U was incorporated into goethite, upon reaction with Fe(II) and ferrihydrite. Uranium incorporation was a particularly dominant retention pathway at U concentrations ? 50 ?M when either uranyl-carbonato or calcium-uranyl-carbonato complexes were dominant, accounting for 64 to 89% of total U. With increasing U(VI) and Fe(II) concentrations, U(VI) reduction to U(IV) became more prevalent, but U incorporation remained a functioning retention pathway. These findings highlight the potential importance of U(V) incorporation within iron oxides as a retention process of U across a wide range of biogeochemical environments and the sensitivity of uranium retention processes to operative (bio)geochemical conditions.

Massey, Michael S.; Lezama Pacheco, Juan S.; Jones, Morris; Ilton, Eugene S.; Cerrato, Jose M.; Bargar, John R.; Fendorf, Scott

2014-10-01T23:59:59.000Z

362

Department of Energy Contractor Diana Lewis Heading to National Small  

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

Department of Energy Contractor Diana Lewis Heading to National Department of Energy Contractor Diana Lewis Heading to National Small Business Week Department of Energy Contractor Diana Lewis Heading to National Small Business Week June 10, 2013 - 8:50am Addthis Department of Energy Contractor Diana Lewis Heading to National Small Business Week John Hale III John Hale III Director, Office of Small and Disadvantaged Business Utilization National Small Business Week is around the corner, kicking off on June 17 across the country. The week honors hundreds of thousands of small business that contract with the federal government every year. Diana Lewis, a West Virginia native and founder of Action Facilities Management, Inc., is one of the small business owners being recognized by her state as the Small Business Person of the Year. During National Small

363

Understanding salt-marsh accretion, Scolt Head Island, Norfolk, England  

Science Journals Connector (OSTI)

Measurements of surface sediment accretion have been obtained for Hut Marsh, Scolt Head Island, Norfolk, England, using sand marker horizons. More than eighty 1-m2 marker sites were deployed in October 1983, and ...

David R. Stoddart; Denise J. Reed; Jonathan R. French

1989-12-01T23:59:59.000Z

364

Theoretical collapse pressures for two pressurized torispherical heads  

SciTech Connect (OSTI)

In order to determine the pressures at which real torispherical heads fail upon a single application of pressure, two heads were pressurized in recent Praxair tests, and displacements and strains were recorded at various locations. In this paper, theoretical results for the two test heads are presented in the form of curves of pressure versus crown deflections, using the available geometry and material parameters. From these curves, limit and collapse pressures are calculated, using procedures permitted by the ASME B and PV Code Section 8/Div.2. These pressures are shown to vary widely, depending on the method and model used to calculate them. The effect of no stress relief on the behavior of the Praxair test heads is also evaluated and found to be of no significance for neither the objectives of the tests nor the objectives of this paper. The results of this paper are submitted as an enhancement to the experimental results recorded during the Praxair tests.

Kalnins, A.; Updike, D.P. [Lehigh Univ., Bethlehem, PA (United States); Rana, M.D. [Praxair, Inc., Tonawanda, NY (United States). Research and Development Dept.

1995-12-01T23:59:59.000Z

365

Energy Savings from Floating Head Pressure in Ammonia Refrigeration Systems  

E-Print Network [OSTI]

This paper presents case studies of two moderately sized ammonia refrigeration systems retrofitted for floating head pressure control. It also presents a parametric analysis to assist in selecting appropriate pressures in an ammonia refrigeration...

Barrer, P. J.; Jones, S. M.

366

Modeling Adhesive Forces for Ultra Low Flying Head Disk Interfaces  

Science Journals Connector (OSTI)

This paper addresses a major issue in microtribology related to the head/disk interface (HDI) in magnetic storage. This is the issue of strong intermolecular (adhesive) forces that may be present at the interf...

Andreas A. Polycarpou

2003-01-01T23:59:59.000Z

367

Designation of the Head of Contracting Activity/Redelegation...  

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

2B, Designation of the Head of Contracting ActivityRedelegation Order No. 00-003.01-02B to the Deputy Director, Office of Acquisition Management by Joseph Waddell Functional...

368

Multi-atlas segmentation in head and neck CT scans  

E-Print Network [OSTI]

We investigate automating the task of segmenting structures in head and neck CT scans, to minimize time spent on manual contouring of structures of interest. We focus on the brainstem and left and right parotids. To generate ...

Arbisser, Amelia M

2012-01-01T23:59:59.000Z

369

Reactivating personal memory 1 RUNNING HEAD: Reactivating personal memory  

E-Print Network [OSTI]

Reactivating personal memory 1 RUNNING HEAD: Reactivating personal memory Modifying memory: Selectively enhancing and updating personal memories for a museum; Reactivating personal memory 2 Abstract Memory can be modified when reactivated

Schacter, Daniel

370

Cellular burning in lean premixed turbulent hydrogen-air flames: Coupling experimental and computational analysis at the laboratory scale  

Science Journals Connector (OSTI)

One strategy for reducing US dependence on petroleum is to develop new combustion technologies for burning the fuel-lean mixtures of hydrogen or hydrogen-rich syngas fuels obtained from the gasification of coal and biomass. Fuel-flexible combustion systems based on lean premixed combustion have the potential for dramatically reducing pollutant emissions in transportation systems, heat and stationary power generation. However, lean premixed flames are highly susceptible to fluid-dynamical combustion instabilities making robust and reliable systems difficult to design. Low swirl burners are emerging as an important technology for meeting design requirements in terms of both reliability and emissions for next generation combustion devices. In this paper, we present simulations of a lean, premixed hydrogen flame stabilized on a laboratory-scale low swirl burner. The simulations use detailed chemistry and transport without incorporating explicit models for turbulence or turbulence/chemistry interaction. Here we discuss the overall structure of the flame and compare with experimental data. We also use the simulation data to elucidate the characteristics of the turbulent flame interaction and how this impacts the analysis of experimental measurements.

M S Day; J B Bell; R K Cheng; S Tachibana; V E Beckner; M J Lijewski

2009-01-01T23:59:59.000Z

371

Effects of Fuel-Side Nitrogen Dilution on Structure and NOx Formation of Turbulent Syngas Non-premixed Jet Flames  

Science Journals Connector (OSTI)

In this syngas non-premixed burner, the nozzle inner and outer diameters are 7.72 mm and 9.46 mm, respectively. ... Prathap, C.; Ray, A.; Ravi, M. R.Investigation of nitrogen dilution effects on laminar burning velocity and flame stability of syngas fuel at atmospheric condition Combust. ...

Jeongwon Lee; Sangwoon Park; Yongmo Kim

2012-05-01T23:59:59.000Z

372

OH-PLIF Measurements of High-Pressure, Hydrogen Augmented Premixed Flames in the SimVal Combustor  

SciTech Connect (OSTI)

Planar Laser Induced Fluorescence (PLIF) measurements of the hydroxyl radical in lean, premixed natural gas flames augmented with hydrogen are presented. The experiments were conducted in the SimVal combustor at the National Energy Technology Laboratory (NETL) at operating pressures from 1 to 8 atmospheres. The data, which was collected in a combustor with well controlled boundary conditions, is intended to be used for validating Computational Fluid Dynamics (CFD) models under conditions directly relevant to land-based gas turbine engines. The images, which show significant effects of hydrogen on local flame quenching are discussed in terms of a turbulent premixed combustion regime and non-dimensional parameters such as Karlovitz number. Pressure was found to thin the OH region, but only had a secondary effect on overall flame shape compared to the effects of hydrogen addition which was found to decrease local quenching and shorten the turbulent flame brush. A method to process the individual images based on local gradients of fluorescence intensity is proposed and results are presented. Finally, the results of several Large Eddy Simulations (LES) are presented and compared to the experimental data in an effort to understand the issues related to model validation, especially for simulations that do not include OH as an intermediate species.

Strakey, P.A.; Woodruff, S.D.; Williams, T.C. (Sandia); Schefer, R.W. (Sandia)

2007-01-01T23:59:59.000Z

373

Acoustic near-field characteristics of a conical, premixed flame Doh-Hyoung Lee and Tim C. Lieuwena)  

E-Print Network [OSTI]

system failure. They gener- ally occur at frequencies associated with the combustor's natural it is influenced by oscillation frequency, combustor geometry, flame length and temperature ratio. The results processing,1 solid and liquid rockets,2,3 ramjets,4 afterburners, and land-based gas turbines.5

Lieuwen, Timothy C.

374

Assessment of kinetic modeling for lean H2/CH4/O2/diluent flames at high pressures  

E-Print Network [OSTI]

) and HO2 + H with the main branching reactions. Methane addition is shown to influence the pressure: Hydrogen; Methane; Syngas; Flame speed; Chemical mechanism 1. Introduction The H2/O2 reaction system CO, CO2, H2O, CH4 and other small hydrocarbons (synthetic gas or "syngas") from coal or biomass

Ju, Yiguang

375

Detailed investigation of a pulverized fuel swirl flame in CO{sub 2}/O{sub 2} atmosphere  

SciTech Connect (OSTI)

A novel approach to oxycoal flame stabilization has been developed at the Institute of Heat and Mass Transfer at RWTH Aachen University [D. Toporov, M. Foerster, R. Kneer, in: Third Int. Conf. on Clean Coal Technologies for Our Future, Cagliari, Sardinia, Italy, 15-17 May 2007]. The swirl burner design and its operating conditions have been adjusted in order to enforce CO formation thus stabilizing the flame and obtaining a full burnout at levels of O{sub 2} content in the O{sub 2}/CO{sub 2} mixture similar to those in air. The paper presents results of detailed numerical and experimental investigations of a stable oxy-fired pulverized coal swirl flame (type-2) obtained with a 21 vol% O{sub 2} concentration. The combustion tests were performed in a vertical pilot-scale furnace (100 kW{sub th}) in the framework of the OXYCOAL-AC research project aiming to develop a membrane-based oxyfuel process. The experimental results concerning gas velocities, gas and particle temperatures, and gas compositions are presented and discussed, focusing on the underlying mechanisms as well as on the aerodynamics of the oxycoal flame. A comparison between measurements and simulations has shown the validity of the numerical method used. The reported data set can be used for validation of numerical models developed for prediction of oxyfuel combustion. (author)

Toporov, D.; Bocian, P.; Heil, P.; Kellermann, A.; Stadler, H.; Tschunko, S.; Foerster, M.; Kneer, R. [Institute of Heat and Mass Transfer, RWTH Aachen University, Eilfschornsteinstrasse 18, D-52056 Aachen (Germany)

2008-12-15T23:59:59.000Z

376

Lawrence Berkeley National Laboratory report LBNL-725E 1 A New Type of Steady and Stable, Laminar, Premixed Flame  

E-Print Network [OSTI]

, Premixed Flame in Ultra-Lean, Hydrogen-Air Combustion Joseph F. Grcara a Center for Computational Science and Engineering Lawrence Berkeley National Laboratory Berkeley, CA 94720-8142, USA Abstract Ultra-lean, hydrogen propagating cells. These cells were the original meaning of the word "flamelet" when they were observed

377

A STUDY ON SPHERICAL EXPANDING FLAME SPEEDS OF METHANE, ETHANE, AND METHANE/ETHANE MIXTURES AT ELEVATED PRESSURES  

E-Print Network [OSTI]

High-pressure experiments and chemical kinetics modeling were performed for laminar spherically expanding flames for methane/air, ethane/air, methane/ethane/air and propane/air mixtures at pressures between 1 and 10 atm and equivalence ratios...

De Vries, Jaap

2010-07-14T23:59:59.000Z

378

Large eddy simulation/conditional moment closure modeling of swirl-stabilized non-premixed flames with local extinction  

E-Print Network [OSTI]

, L. Vervisch, P. Domingo, Combust. Flame 146 (2006), 635-648. 28. S. Navarro-Martinez, A. Kronenburg, F.D. Mare, Flow Turbul. Combust. 75 (2005), 245-274. 29. A. Triantafyllidis, E. Mastorakos, Flow Turbul. Combust. 84 (2010), 481-512. 30. M...

Zhang, Huangwei; Garmory, Andrew; Cavaliere, Davide E.; Mastorakos, Epaminondas

2014-06-25T23:59:59.000Z

379

Bicycle helmets are highly effective at preventing head injury during head impact: Head-form accelerations and injury criteria for helmeted and unhelmeted impacts  

Science Journals Connector (OSTI)

Abstract Cycling is a popular form of recreation and method of commuting with clear health benefits. However, cycling is not without risk. In Canada, cycling injuries are more common than in any other summer sport; and according to the US National Highway and Traffic Safety Administration, 52,000 cyclists were injured in the US in 2010. Head injuries account for approximately two-thirds of hospital admissions and three-quarters of fatal injuries among injured cyclists. In many jurisdictions and across all age levels, helmets have been adopted to mitigate risk of serious head injuries among cyclists and the majority of epidemiological literature suggests that helmets effectively reduce risk of injury. Critics have raised questions over the actual efficacy of helmets by pointing to weaknesses in existing helmet epidemiology including selection bias and lack of appropriate control for the type of impact sustained by the cyclist and the severity of the head impact. These criticisms demonstrate the difficulty in conducting epidemiology studies that will be regarded as definitive and the need for complementary biomechanical studies where confounding factors can be adequately controlled. In the bicycle helmet context, there is a paucity of biomechanical data comparing helmeted to unhelmeted head impacts and, to our knowledge, there is no data of this type available with contemporary helmets. In this research, our objective was to perform biomechanical testing of paired helmeted and unhelmeted head impacts using a validated anthropomorphic test headform and a range of drop heights between 0.5 m and 3.0 m, while measuring headform acceleration and Head Injury Criterion (HIC). In the 2 m (6.3 m/s) drops, the middle of our drop height range, the helmet reduced peak accelerations from 824 g (unhelmeted) to 181 g (helmeted) and HIC was reduced from 9667 (unhelmeted) to 1250 (helmeted). At realistic impact speeds of 5.4 m/s (1.5 m drop) and 6.3 m/s (2.0 m drop), bicycle helmets changed the probability of severe brain injury from extremely likely (99.9% risk at both 5.4 and 6.3 m/s) to unlikely (9.3% and 30.6% risk at 1.5 m and 2.0 m drops respectively). These biomechanical results for acceleration and HIC, and the corresponding results for reduced risk of severe brain injury show that contemporary bicycle helmets are highly effective at reducing head injury metrics and the risk for severe brain injury in head impacts characteristic of bicycle crashes.

Peter A. Cripton; Daniel M. Dressler; Cameron A. Stuart; Christopher R. Dennison; Darrin Richards

2014-01-01T23:59:59.000Z

380

Gas-Phase Identity SN2 Reactions of Halide Anions and Methyl Halides with Retention of Configuration  

E-Print Network [OSTI]

Gas-Phase Identity SN2 Reactions of Halide Anions and Methyl Halides with Retention back-side and front-side SN2 reactions are found to involve the same ion-molecule complex (X-,,,H3CX of a front-side SN2 reaction with retention of configuration at saturated carbon. Analysis of our

Schlegel, H. Bernhard

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381

Body retention and tissue distribution of59Fe and 54Mn in newborn rats fed iron-supplemented cow's milk  

E-Print Network [OSTI]

Body retention and tissue distribution of59Fe and 54Mn in newborn rats fed iron-supplemented cow distribution has been studied in newborn rats. Six-day old rats, divided into three groups were artificially retention in newborn rats, whereas it enhanced 59Fe deposition in the liver and the intestinal wall and

Boyer, Edmond

382

Interventions to improve recruitment and retention in clinical trials: a survey and workshop to assess current practice and future priorities  

Science Journals Connector (OSTI)

Recruitment and retention in clinical trials is still a major challenge and are of high priority for many Clinical Trials Units. Using survey and workshop data, methods used to encourage recruitment and retention were categorised and the authors highlighted areas for prioritising further methodological research.

Peter Bower; Valerie Brueton; Carrol Gamble; Shaun Treweek; Catrin Smith; Bridget Young; Paula Williamson

2014-10-16T23:59:59.000Z

383

Larval retention and recruitment in an island population of a coral-reef fish  

Science Journals Connector (OSTI)

... windward shore (Jack's Bay) and two down-current sites on the leeward shore (Northstar and Butler Bay) during the summer and autumn of 1992. For this analysis, ... of local retention of larvae to recruitment. At both leeward reefs (Butler Bay and Northstar, Fig. 2a, b), recruitment levels were positively correlated with CF1, indicating that ...

Stephen E. Swearer; Jennifer E. Caselle; David W. Lea; Robert R. Warner

1999-12-16T23:59:59.000Z

384

Uptake and retention kinetics of para-fluorine-18-fluorobenzylguanidine in isolated rat heart  

SciTech Connect (OSTI)

Para-[{sup 18}F]fluorobenzylguanidine ([{sup 18}F]PFBG) is a newly developed tracer for imaging myocardial sympathetic neuronal innervation. This study investigated the uptake and retention mechanisms of [{sup 18}F]PFBG in perfused, isolated rat heart. 31 refs., 3 figs., 2 tabs.

Berry, C.R.; Garg, P.K.; Zalutsky, M.R. [North Carolina State Univ., Raleigh, NC (United States)]|[Duke Univ. Medical Center, Durham, NC (United States)] [and others

1996-12-01T23:59:59.000Z

385

On the long-term retention of geometry-centric digital engineering artifacts  

Science Journals Connector (OSTI)

This paper discusses the challenges of long-term preservation of digital geometric models and the engineering processes associated with them. For engineering, design, manufacturing, and physics-based simulation data this requires formats that are accessible ... Keywords: Digital preservation, Knowledge capture, Long-term knowledge retention, Representation, Standards

William C. Regli; Joseph B. Kopena; Michael Grauer

2011-07-01T23:59:59.000Z

386

Ca RETENTION IN YOUNG PULLETS AND LAYING HENS FED A Ca47 LABELLED DIET  

E-Print Network [OSTI]

Ca RETENTION IN YOUNG PULLETS AND LAYING HENS FED A Ca47 LABELLED DIET OF DIFFERENT Ca LEVELS K levels of dietary calcium. A basal diet poor in calcium but otherwise optimal was supplemented with CaC03 and Na2HP04 as seen below : #12;CaCO, supplement of the diet was replaced by Ca&dquo; labelled Calcium

Paris-Sud XI, Université de

387

Nuclear magnetic relaxation dispersion investigations1 of water retention mechanism by cellulose ethers in mortars2  

E-Print Network [OSTI]

Nuclear magnetic relaxation dispersion investigations1 of water retention mechanism by cellulose : 10.1016/j.cemconres.2012.06.002 #12;2 ABSTRACT22 23 We show how nuclear magnetic spin-lattice relaxation dispersion of protons-water24 (NMRD) can be used to elucidate the effect of cellulose ethers

Boyer, Edmond

388

Retention of Radioactive Substances in the Body of Rats and the Lethal Dose  

Science Journals Connector (OSTI)

... proved to be dangerous1. For this reason only two elements have been studied, namely, radon and polonium, with regard to their retention in the organism and quick elimination by ... 66 gm. to 290 gm. The present communication deals with the results obtained with radon only. A physiological solution, namely, a 10 per cent solution of glucose or ...

F. BHOUNEK; F. V. NOVÁK

1937-07-17T23:59:59.000Z

389

Mesh Width Influences Prey Retention in Spider Orb Webs Todd A. Blackledge & Jacquelyn M. Zevenbergen  

E-Print Network [OSTI]

Mesh Width Influences Prey Retention in Spider Orb Webs Todd A. Blackledge & Jacquelyn M. Zevenbergen Department of Biology, The University of Akron, Akron, OH, USA Introduction Orb webs depend upon threads, the sticky spirals of orb webs perform two important functions during prey cap- ture. First

Blackledge, Todd

390

QSPR models of boiling point, octanolwater partition coefficient and retention time index of polycyclic aromatic hydrocarbons  

E-Print Network [OSTI]

QSPR models of boiling point, octanol­water partition coefficient and retention time index of polycyclic aromatic hydrocarbons Fabiana Alves de Lima Ribeiro, Ma´rcia Miguel Castro Ferreira* Laborato Structure­Property Relationship (QSPR) analysis and study of polycyclic aromatic hydrocarbons (PAHs

Ferreira, Márcia M. C.

391

Retention and entrainment effects: Experiments and theory for porous spheres settling in sharply stratified fluids  

E-Print Network [OSTI]

be important for accurate modeling of the vertical carbon flux in the ocean. A first step in this direction with a first-principle model based on diffusive processes. The model correctly predicts accelerations. With this parametrization, which exhibits a power law dependence on Reynolds numbers, retention times are accurately

McLaughlin, Richard M.

392

Effect of Nitrogen Additives on Flame Retardant Action of Tributyl Phosphate: Phosphorus – Nitrogen Synergism  

SciTech Connect (OSTI)

The effect of nitrogen additives like urea, guanidine carbonate and melamine formaldehyde on the flame retardant efficacy of tributyl phosphate (TBP) has been investigated. From the LOI tests on treated cotton it is clear that the nitrogen additives have synergistic action. Estimation of activation energy of decomposition of treated cotton indicated that nitrogen additives enhance the thermal stability during the burning process. SEM pictures of chars formed after LOI test showed the formation of protective polymeric coating on the surface. The surface of chars formed were evaluated using FTIR-ATR and XPS analysis which showed that the coating was composed of Phosphorus-Nitrogen-Oxygen containing species. Formation of this coating during the burning process could lead to the synergistic interaction of phosphorus and nitrogen. Based on the experimental data we have further proposed several reaction mechanisms which could contribute to synergistic action and formation of protective coating on the surface of char.

Gaan, Sabyasachi; Sun, Gang; Hutches, Katherine; Engelhard, Mark H.

2008-01-01T23:59:59.000Z

393

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

SciTech Connect (OSTI)

The advanced CFDRC software package was installed on a SUN-SPARC dual processor workstation (UTPA funded). The literature pertinent to the project was collected. The physical model was set and all parameters and variables were identified. Based on the physical model, the geometric modeling and grid generation processes were performed using the CFD-GEOM (Interactive Geometric Modeling and Grid Generation software). A total number of 11160 cells (248 x 45) were generated. The venturis in the cascade were modeled as two-dimensional axisymmetric convergent nozzles around the jet. With the cascade being added to the jet, the geometric complexity of the problem increased; which required multi-domain structured grid systems to be connected and matched on the boundaries. The natural gas/propane jet diffusion flame is being numerically analyzed. The numerical computations are being conducted using the CFDRC-ACE+ (advanced computational environment) software package. The results are expected soon.

Ala Qubbaj

2001-03-30T23:59:59.000Z

394

Chemiluminescence-based multivariate sensing of local equivalence ratios in premixed atmospheric methane-air flames  

SciTech Connect (OSTI)

Chemiluminescence emissions from OH*, CH*, C2, and CO2 formed within the reaction zone of premixed flames depend upon the fuel-air equivalence ratio in the burning mixture. In the present paper, a new partial least square regression (PLS-R) based multivariate sensing methodology is investigated and compared with an OH*/CH* intensity ratio-based calibration model for sensing equivalence ratio in atmospheric methane-air premixed flames. Five replications of spectral data at nine different equivalence ratios ranging from 0.73 to 1.48 were used in the calibration of both models. During model development, the PLS-R model was initially validated with the calibration data set using the leave-one-out cross validation technique. Since the PLS-R model used the entire raw spectral intensities, it did not need the nonlinear background subtraction of CO2 emission that is required for typical OH*/CH* intensity ratio calibrations. An unbiased spectral data set (not used in the PLS-R model development), for 28 different equivalence ratio conditions ranging from 0.71 to 1.67, was used to predict equivalence ratios using the PLS-R and the intensity ratio calibration models. It was found that the equivalence ratios predicted with the PLS-R based multivariate calibration model matched the experimentally measured equivalence ratios within 7%; whereas, the OH*/CH* intensity ratio calibration grossly underpredicted equivalence ratios in comparison to measured equivalence ratios, especially under rich conditions ( > 1.2). The practical implications of the chemiluminescence-based multivariate equivalence ratio sensing methodology are also discussed.

Tripathi, Markandey M.; Krishnan, Sundar R.; Srinivasan, Kalyan K.; Yueh, Fang-Yu; Singh, Jagdish P.

2012-03-01T23:59:59.000Z

395

Flame pyrolysis – a preparation route for ultrafine pure ?-Fe2O3 powders and the control of their particle size and properties  

Science Journals Connector (OSTI)

Highly dispersed ?-Fe2O3 powders with particle sizes down to 5 nm were directly synthesized by combustion of solutions of iron pentacarbonyl or iron(III) acetylacetonate in toluene in an oxyhydrogen flame. The .....

S GRIMM; M SCHULTZ; S BARTH; R MULLER

396

Enhancements of a Combustion Vessel to Determine Laminar Flame Speeds of Hydrocarbon Blends with Helium Dilution at Elevated Temperatures and Pressures  

E-Print Network [OSTI]

in conjunction with National University of Ireland Galway compared favorably with the data, while the literature data showed discrepancies at stoichiometric to rich conditions. An in-depth flame speed uncertainty analysis yielded a wide range of values from 0...

Plichta, Drew

2013-04-03T23:59:59.000Z

397

The study of flame dynamics and structures in an industrial-scale gas turbine combustor using digital data processing and computer vision techniques  

Science Journals Connector (OSTI)

In this paper, a combined effort has been made to study the flame dynamics and structures in a gas turbine combustor using a range of imaging and digital data processing techniques. The acoustic characteristics of the combustor have been investigated extensively. It is found that there is no straightforward way to alter the peak frequency of one of the peculiar combustion modes of the rig. High speed imaging is applied to investigate the flame dynamics and quantitative analysis of the image database has been demonstrated. The results show that the frequency spectrum of the mean pixel image intensity of seeded flame is in good agreement with the acoustic spectrum. To recover the loss in depth information present in conventional imaging technique, both the optical and digital stereo imaging techniques have been applied. The important flame position relative to the combustion chamber could be resolved.

W.B. Ng; K.J. Syed; Y. Zhang

2005-01-01T23:59:59.000Z

398

In-vessel Retention Strategy for High Power Reactors - K-INERI Final Report (includes SBLB Test Results for Task 3 on External Reactor Vessel Cooling (ERVC) Boiling Data and CHF Enhancement Correlations)  

SciTech Connect (OSTI)

In-vessel retention (IVR) of core melt is a key severe accident management strategy adopted by some operating nuclear power plants and proposed for some advanced light water reactors (ALWRs). If there were inadequate cooling during a reactor accident, a significant amount of core material could become molten and relocate to the lower head of the reactor vessel, as happened in the Three Mile Island Unit 2 (TMI-2) accident. If it is possible to ensure that the vessel head remains intact so that relocated core materials are retained within the vessel, the enhanced safety associated with these plants can reduce concerns about containment failure and associated risk. For example, the enhanced safety of the Westinghouse Advanced 600 MWe PWR (AP600), which relied upon External Reactor Vessel Cooling (ERVC) for IVR, resulted in the U.S. Nuclear Regulatory Commission (US NRC) approving the design without requiring certain conventional features common to existing LWRs. However, it is not clear that currently proposed external reactor vessel cooling (ERVC) without additional enhancements could provide sufficient heat removal for higher-power reactors (up to 1500 MWe). Hence, a collaborative, three-year, U.S. - Korean International Nuclear Energy Research Initiative (INERI) project was completed in which the Idaho National Engineering and Environmental Laboratory (INEEL), Seoul National University (SNU), Pennsylvania State University (PSU), and the Korea Atomic Energy Research Institute (KAERI) investigated the performance of ERVC and an in-vessel core catcher (IVCC) to determine if IVR is feasible for reactors up to 1500 MWe.

F. B. Cheung; J. Yang; M. B. Dizon; J. Rempe

2005-01-01T23:59:59.000Z

399

A Discussion of SY-101 Crust Gas Retention and Release Mechanisms  

SciTech Connect (OSTI)

The flammable gas hazard in Hanford waste tanks was made an issue by the behavior of double-shell Tank (DST) 241-SY-101 (SY-101). Shortly after SY-101 was filled in 1980, the waste level began rising periodically, due to the generation and retention of gases within the slurry, and then suddenly dropping as the gases were released. An intensive study of the tank's behavior revealed that these episodic releases posed a safety hazard because the released gas was flammable, and, in some cases, the volume of gas released was sufficient to exceed the lower flammability limit (LFL) in the tank headspace (Allemann et al. 1993). A mixer pump was installed in SY-101 in late 1993 to prevent gases from building up in the settled solids layer, and the large episodic gas releases have since ceased (Allemann et al. 1994; Stewart et al. 1994; Brewster et al. 1995). However, the surface level of SY-101 has been increasing since at least 1995, and in recent months the level growth has shown significant and unexpected acceleration. Based on a number of observations and measurements, including data from the void fraction instrument (VFI), we have concluded that the level growth is caused largely by increased gas retention in the floating crust. In September 1998, the crust contained between about 21 and 43% void based on VFI measurements (Stewart et al. 1998). Accordingly, it is important to understand the dominant mechanisms of gas retention, why the gas retention is increasing, and whether the accelerating level increase will continue, diminish or even reverse. It is expected that the retained gas in the crust is flammable, with hydrogen as a major constituent. This gas inventory would pose a flammable gas hazard if it were to release suddenly. In May 1997, the mechanisms of bubble retention and release from crust material were the subject of a workshop. The evaluation of the crust and potential hazards assumed a more typical void of roughly 15% gas. It could be similar to percolati on in single-shell tank (SST) waste forms. The much higher void being currently observed in SY-101 represents essentially a new crust configuration, and the mechanisms for sudden gas release need to be evaluated. The purpose of this study is to evaluate the situation of gas bubbles in crust based on the previous work on gas bubble retention, migration, and release in simulants and actual waste. We have also conducted some visual observations of bubble migration through simulated crusts to help understand the interaction of the various mechanisms.

SD Rassat; PA Gauglitz; SM Caley; LA Mahoney; DP Mendoza

1999-02-23T23:59:59.000Z

400

Katie Antypas Named New Head of NERSC User Services Department  

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

Katie Antypas Named Katie Antypas Named New Head of NERSC Services Department Katie Antypas Named New Head of NERSC Services Department September 3, 2013 katie2 Katie Antypas Katie Antypas, who has led NERSC's User Services Group since October 2010, has been named as the new Services Department Head, effective September 23. Antypas succeeds Francesca Verdier, who will serve as Allocations Manager until her planned retirement in June 2014. Antypas is also the project lead for the NERSC-8 system procurement, a project to deploy NERSC's next generation system in the 2015 timeframe. "Katie's leadership in ensuring that NERSC users are able to maximize their use of both our current and future systems has positioned her well to help lead NERSC users and staff into the next era of extreme scale

Note: This page contains sample records for the topic "flame retention head" 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

World's Largest Solar Energy Project Heads to Mojave | Department of  

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

World's Largest Solar Energy Project Heads to Mojave World's Largest Solar Energy Project Heads to Mojave World's Largest Solar Energy Project Heads to Mojave April 16, 2010 - 4:47pm Addthis A California company will harness the Mojave Desert sunshine to create the world's largest solar energy system by the end of 2013. The Ivanpah Solar Electric Generating System, located just a few miles from the California - Nevada border near Interstate 15, will generate approximately 400 MW of energy per year, almost doubling the amount of solar thermal energy produced in the United States. Ivanpah will focus sunlight from mirrors placed on poles, which don't require the land to be graded and can be placed around areas that are already in use or environmentally sensitive. The project of Oakland, Calif.-based BrightSource Energy, Inc. will likely generate enough power

402

NREL: Photovoltaics Research - Solar Decathlon Heads to California for 2013  

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

Decathlon Heads to California for 2013 Event Decathlon Heads to California for 2013 Event Photo showing the aerial view of several structures with solar panels on top. Aerial view of the U.S. Department of Energy Solar Decathlon 2011 in Washington, D.C. (Credit: Stefano Paltera/U.S. Department of Energy Solar Decathlon) January 11, 2013 For the first time, the U.S. Department of Energy Solar Decathlon will be held outside of Washington, D.C. This fall, 20 collegiate teams will head to the Orange Country Great Park in Irvine, California, to compete in this award-winning showcase of energy-efficient and solar-powered houses. The free event will take place in a specially constructed village Oct. 3-13, 2013. The competition houses will be open to visitors on eight days over two weekends. Public hours will be from 11 a.m. to 7 p.m. daily:

403

Sprinkler Head Replacement (4586), 4/24/2012  

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

Sprinkler Head Replacement Projects (4586) Sprinkler Head Replacement Projects (4586) Program or Field Office: Y-12 Site Office Location(s) (Citv/Countv/State): Oak Ridge, Anderson County, Tennessee Proposed Action Description: The proposed action is to replace approximately 1 ,300 sprinkler heads upgrade fire protection systems. Categorical Exclusion(s) Applied: 81.3- Routine maintenance Submit by E-mail For the complete DOE National Environmental Policy Act regulations regarding categorical exclusions, including the full text of each categorical exclusion, see Subpart D of 10 CFR Part 1021. Regulatory Requirements in 10 CFR 1021.410(b): (See full text in regulation) [{Jrhe proposal fits within a class of actions that is listed in Appendix A orB to 10 CFR Part 1021, Subpart D. To fit within the classes of actions listed in 10 CFR Part 1021, Subpart D, Appendix B, a proposal must be one that would not: (1) threaten

404

Srinivasan Named Head of NERSC's Computational Systems Group  

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

Srinivasan Named Head Srinivasan Named Head of NERSC's Computational Systems Group Srinivasan Named Head of NERSC's Computational Systems Group August 31, 2011 | Tags: NERSC Jay Srinivasan has been selected as the Computational Systems Group Lead in the NERSC Systems Department. In this role, he will supervise the day-to-day operation of all of NERSC's computer systems. Prior to taking on his new assignment, Srinivasan was the team lead for the PDSF cluster that supports Nuclear Physics and High Energy Physics. Srinivasan has more than 15 years of experience in high performance computing, both as a user and administrator. Since joining NERSC in 2001, he has worked on all the large systems from NERSC-3, the IBM/SP2 system called Seaborg, to Hopper, the Cray XE6 that is currently NERSC's

405

EM's Los Alamos TRU Waste Campaign Heads Toward Completion | Department  

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

EM's Los Alamos TRU Waste Campaign Heads Toward Completion EM's Los Alamos TRU Waste Campaign Heads Toward Completion EM's Los Alamos TRU Waste Campaign Heads Toward Completion November 20, 2013 - 12:00pm Addthis Advanced techniques allowed crews at Los Alamos National Laboratory to decontaminate large boxes of waste so it could be shipped as mixed low-level rather than transuranic waste. Advanced techniques allowed crews at Los Alamos National Laboratory to decontaminate large boxes of waste so it could be shipped as mixed low-level rather than transuranic waste. The EM program at Los Alamos National Laboratory exceeded its shipping goals in fiscal year 2013, shipping twice as much waste as it did in fiscal year 2012. The EM program at Los Alamos National Laboratory exceeded its shipping goals in fiscal year 2013, shipping twice as much waste as it did in fiscal

406

Nags Head, North Carolina: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

Nags Head, North Carolina: Energy Resources Nags Head, North Carolina: Energy Resources (Redirected from Nags Head, NC) Jump to: navigation, search Equivalent URI DBpedia Coordinates 35.9573922°, -75.6240619° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":35.9573922,"lon":-75.6240619,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

407

Los Alamos names new head of stockpile manufacturing and support  

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

New head of stockpile manufacturing and support New head of stockpile manufacturing and support Los Alamos names new head of stockpile manufacturing and support Carl Beard is the new associate director for stockpile manufacturing and support. Beard has held this position in an acting capacity since June 2007. January 22, 2008 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials.

408

Los Alamos National Laboratory names new head of weapons programs  

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

Laboratory names new head of weapons programs Laboratory names new head of weapons programs Los Alamos National Laboratory names new head of weapons programs Bret Knapp has been acting in that position since June 2011. December 1, 2011 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Contact Kevin Roark Communications Office (505) 665-9202

409

MHK Projects/Kendall Head Tidal Energy | Open Energy Information  

Open Energy Info (EERE)

Kendall Head Tidal Energy Kendall Head Tidal Energy < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":5,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"500px","height":"350px","centre":false,"title":"","label":"","icon":"File:Aquamarine-marker.png","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[]}

410

An improved dosimetric model of the head and brain  

E-Print Network [OSTI]

Br). Other radionuclides considered may deposit in bone withm the head region (cranium or the spinal skeleton) (is'I, 2P, ssP, tssRe, 'ssRe, 'ssSm, "7~Sb, ssSr, s Sr, "nY, ss~Tc, tsiCs, ss"Ra), or m the thyroid fss~ Tc, and all iodme radionuclides... tagged to them (i. e. , radiopharmaceuticals). Nevertheless, studies of the small-scale dosimetry of the bram, and more generally, the organs of the head (brain, eyes thyroid, skull, skin), have not kept pace with the current advances in nuclear...

Bouchet, Lionel Gerard

1995-01-01T23:59:59.000Z

411

A Detailed Chemical Kinetic Reaction Mechanism for Oxidation of Four Small Alkyl Esters in Laminar Premixed Flames  

SciTech Connect (OSTI)

A detailed chemical kinetic reaction mechanism has been developed for a group of four small alkyl ester fuels, consisting of methyl formate, methyl acetate, ethyl formate and ethyl acetate. This mechanism is validated by comparisons between computed results and recently measured intermediate species mole fractions in fuel-rich, low pressure, premixed laminar flames. The model development employs a principle of similarity of functional groups in constraining the H atom abstraction and unimolecular decomposition reactions in each of these fuels. As a result, the reaction mechanism and formalism for mechanism development are suitable for extension to larger oxygenated hydrocarbon fuels, together with an improved kinetic understanding of the structure and chemical kinetics of alkyl ester fuels that can be extended to biodiesel fuels. Variations in concentrations of intermediate species levels in these flames are traced to differences in the molecular structure of the fuel molecules.

Westbrook, C K; Pitz, W J; Westmoreland, P R; Dryer, F L; Chaos, M; Osswald, P; Kohse-Hoinghaus, K; Cool, T A; Wang, J; Yang, B; Hansen, N; Kasper, T

2008-02-08T23:59:59.000Z

412

November 13 - 15, 2012 HSS Work Group Leadership Meeting Summary - Work Force Retention  

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

Work Force Retention Work Group Work Force Retention Work Group Co-Lead Telecom November 16, 2012 DRAFT Discussion Overview Purpose: This HSS Focus Group Work Group telecom was held with the Work Group Co-Leads to discuss change elements and strategic direction to support accelerated efforts to advancing progress, productivity and performance within each of the Work Groups. Although current roles within all of the Work Groups and Focus Group efforts remain the same, the addition of centralized leadership and oversight by representatives (2) of the Departmental Representative to the Defense Nuclear Facilities Safety Board are established. 1. Leadership Transition * Co-Leads will continue to provide technical functions * Functions of the Focus Group Program will remain the same. [Lily/Stephanie]

413

RESRAD soil concentration guidelines for the Old F-Area Retention Basin  

SciTech Connect (OSTI)

Concentration guidelines for residual radionuclides in soil at the site of the Old F-Area Retention Basin have been calculated using a dose-based approach. Estimation of these soil guidelines was completed using RESRAD 5.0 in accordance with the DOE RESRAD methodology specified in DOE/CH/8901. Guidelines are provided for the two predominant nuclides, Sr-90 and Cs-137, known to be present in the soil beneath the old basin. A guideline is also given for Pu-238 since it is known to exist at the H-Area Retention Basin. Site-specific soil characteristics are defined for the areas above, within, and beneath the contaminated zone.

Hamby, D.M.

1994-02-24T23:59:59.000Z

414

Turbulence radiation interaction in Reynolds-averaged Navier-Stokes simulations of nonpremixed piloted turbulent laboratory-scale flames  

SciTech Connect (OSTI)

Numerical simulation results are presented for two axisymmetric, nonluminous turbulent piloted jet diffusion flames: Sandia Flame D (SFD) and Delft Flame III (DFIII). Turbulence is represented by a Reynolds stress transport model, while chemistry is modeled by means of steady laminar flamelets. We use the preassumed PDF approach for turbulence-chemistry interaction. A weighted sum of gray gases model is used for the gas radiative properties. The radiative transfer equation is solved using the discrete ordinates method in the conservative finite-volume formulation. The radiative loss leads to a decrease in mean temperature, but does not significantly influence the flow and mixing fields, in terms either of mean values or of rms values of fluctuations. A systematic analysis of turbulence-radiation interaction (TRI) is carried out. By considering five different TRI formulations, and comparing also with a simple optically thin model, individual TRI contributions are isolated and quantified. For both flames, effects are demonstrated of (1) influence of temperature fluctuations on the mean Planck function, (2) temperature and composition fluctuations on the mean absorption coefficient, and (3) correlation between absorption coefficient and Planck function. The strength of the last effect is stronger in DFIII than in SFD, because of stronger turbulence-chemistry interaction and lower mean temperature in DFIII. The impact of the choice of TRI model on the prediction of the temperature-sensitive minor species NO is determined in a postprocessing step with fixed flow and mixing fields. Best agreement for NO is obtained using the most complete representation of TRI. (author)

Habibi, A.; Merci, B. [Department of Flow, Heat and Combustion Mechanics, Ghent University, B-9000 Ghent (Belgium); Roekaerts, D. [Delft University of Technology, Delft (Netherlands)

2007-10-15T23:59:59.000Z

415

Combustion regimes of particle-laden gaseous flames: influences of radiation, molecular transports, kinetic-quenching, stoichiometry  

Science Journals Connector (OSTI)

We study flat flames propagating steadily in a reactive gaseous premixture which is seeded with an inert solid suspension. Our main assumptions are: (i) the two-reactant, one-step overall reaction we choose as the combustion process has a rate which vanishes at and below a prescribed temperature (Tc) and resumes the Arrhenius form at higher temperatures; (ii) both phases are considered as continua and have the same local speed and temperature; (iii) radiation among the particles follows the Eddington approximation specialized to a grey medium and the attenuation length markedly exceeds the conduction - convection length in the gas; (iv) the activation energy is large. The first regimes we consider comprise a thin flame front (dominated by molecular transports, convection and chemistry) embedded in much thicker radiation - convection zones. Jump conditions across the former are derived analytically and then used as targets in a shooting method to analyse the thickest zones and compute the burning speed (U). Such regimes only exist for equivalence ratios () above a load-dependent critical value which corresponds to a turning point of the U() curve. This turning point is due to radiative heat losses from the thin flame front to the cooler adjacent zones, which lead to extinction. Over restricted, well defined ranges of composition other regimes may also exist, which have monotonic temperature profiles culminating slightly above Tc. When they are too thick to be affected by molecular transports and are thus similar to coal-dust -air flames, their structure, domain of existence and speed are investigated analytically and numerically. The corresponding U() curve exhibits an upper limit equivalence ratio * characterized by an end-point, beyond which such regimes cannot exist. The influence of molecular diffusion is then accounted for and shown to modify the results only slightly.

Rodolphe Blouquin; Guy Joulin; Younès Merhari

1997-01-01T23:59:59.000Z

416

Comparative NEXAFS Study on Soot Obtained from an Ethylene/Air Flame, a Diesel Engine, and Graphite  

Science Journals Connector (OSTI)

Comparative NEXAFS Study on Soot Obtained from an Ethylene/Air Flame, a Diesel Engine, and Graphite ... Aerosol and Nanostructures Laboratory, Istituto Motori, CNR, Napoli, Italy, and Department of Chemical and Materials Engineering and Consortium for Fossil Fuel Science, University of Kentucky, Lexington, Kentucky 40515 ... Microstructure and molecular structure properties of different carbonaceous byproducts from combustion are fundamental to evaluate the radiative properties of such materials when combustion aerosols interact with solar radiation in atmosphere. ...

Stefano di Stasio; Artur Braun

2005-11-15T23:59:59.000Z

417

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

418

Arsenate and Arsenite Retention and Release in Oxide and Sulfide Dominated Systems  

E-Print Network [OSTI]

Arsenate and Arsenite Retention and Release in Oxide and Sulfide Dominated Systems Principal Investigator: Richard H. Loeppert Co-Investigators: Amita Jain Klaus Raven Jianlin Wang Soil & Crop Sciences Dept. Texas A&M University College Station, TX... Resources Institute. Non-Federal matching funds were provided by the Soil & Crop Sciences Dept., Texas A&M University, College Station, TX. A portion of this report was adapted from a part of a dissertation by Jianlin Wang which will be submitted...

Loeppert, Richard H.; Jain, Amita; Raven, Klaus; Wang, Jianlin

419

Determination of the retention function of [superscript 67]Ga in canine  

E-Print Network [OSTI]

()))()] Fecal excretion was the primary route of elimination of gallium, accounting for 63K of the gallium excreted, during the 12 days of observation, Due to the wide variation in gallium retention exhibited by the individual dogs, it is recommended... ABSTRACT . . . ~ ACKNOWLEDGEMENTS TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES INTRODUCTION LITERATURE REVIEW vi vii viii 3 History Gallium Kinetics Physical Properties of 67Ga METHODS AND MATERIAL 3 4 18 21 Research Subjects...

Schoenbucher, Bruce

2012-06-07T23:59:59.000Z

420

Professional School Psychology Programs' Recruitment and Retention of Culturally and Linguistically Diverse Students  

E-Print Network [OSTI]

graduate students of color. American Psychologist, 61, 143-156. Sanders, J. B., Wilson, M., & Jones, J. (2010). Generating Markets: Recruitment for programs and program faculty, encouraging diversity. Trainers Forum, 29 (2),32-35. Solomon, David J... PROFESSIONAL PSYCHOLOGY PROGRAMS? RECRUITMENT AND RETENTION OF CULTURALLY AND LINGUISTICALLY DIVERSE STUDENTS Major: Mathematics April 2011 Submitted to the Office of Undergraduate Research Texas A&M University...

Smith, Leann

2011-08-08T23:59:59.000Z

Note: This page contains sample records for the topic "flame retention head" 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

Experimental and modeling study of the effect of elevated pressure on lean high-hydrogen syngas flames  

Science Journals Connector (OSTI)

Abstract New laminar burning velocity measurements of 85:15% (by volume) H2–CO and H2–N2 mixtures with O2–He oxidizer are reported at lean conditions and elevated pressures (1–10 atm). Experiments are conducted using the heat flux method at initial temperature of 298 K. In this technique a near adiabatic flame is stabilized by balancing the heat loss from the flame to the burner with heat gain to the unburnt gas mixture such that no net heat loss to the burner is observed. A new facility was designed for such high pressure burner stabilized flame experiments. The results obtained are compared with five chemical kinetic schemes from literature for syngas mixtures at elevated pressures. Large differences are observed between the kinetic schemes and the experiments which can be attributed to certain key chemical reactions. A study of the kinetics is performed through reaction rate and sensitivity analysis which indicate that a high uncertainty still remains in important reactions that drive the production and consumption of species such as H, HO2 and OH. For lean mixtures the reaction H + O2(+M) = HO2(+M) contributes significantly to the deviation of models from the experiments. The present analysis in the lean mixture regime suggests the need for further studies in assessment and modification of rate constants for this reaction.

M. Goswami; J.G.H. van Griensven; R.J.M. Bastiaans; A.A. Konnov; L.P.H. de Goey

2014-01-01T23:59:59.000Z

422

Flame aerosol nano-technology has been developed to preparation of thin and defect-free porous membrane from the gas phase as a one step method in preparation of membrane for gas  

E-Print Network [OSTI]

Abstract Flame aerosol nano-technology has been developed to preparation of thin and defect on deposition of nano particles (-Al2O3, MgO or spinel MgAl2O4), formed in the premixed flame reactor through/or aluminium precursors in the flame to form nano-particles of -Al2O3, MgO or MgAl2O4 spinel. The generated

423

Theoretical Analysis of Antibody Targeting of Tumor Spheroids: Importance of Dosage for Penetration, and Affinity for Retention  

Science Journals Connector (OSTI)

...processes determine tumor penetration rate and subsequent retention...incrementally affect the rate of tumor penetration. The moving reaction front...different parameters affect the rate of tumor penetration. R, Ag t , and describe...

Christilyn P. Graff and K. Dane Wittrup

2003-03-15T23:59:59.000Z

424

Investigation of the use of nanofluids to enhance the In-Vessel Retention capabilities of Advanced Light Water Reactors  

E-Print Network [OSTI]

Nanofluids at very low concentrations experimentally exhibit a substantial increase in Critical Heat Flux (CHF) compared to water. The use of a nanofluid in the In-Vessel Retention (IVR) severe accident management strategy, ...

Hannink, Ryan Christopher

2007-01-01T23:59:59.000Z

425

Investigation of downward facing critical heat flux with water-based nanofluids for In-Vessel Retention applications  

E-Print Network [OSTI]

In-Vessel Retention ("IVR") is a severe accident management strategy that is power limiting to the Westinghouse AP1000 due to critical heat flux ("CHF") at the outer surface of the reactor vessel. Increasing the CHF level ...

DeWitt, Gregory L

2011-01-01T23:59:59.000Z

426

SFU RECREATION & ATHLETICS EMPLOYMENT OPPORTUNITY SFU CAMPS HEAD INSTRUCTOR  

E-Print Network [OSTI]

SFU RECREATION & ATHLETICS EMPLOYMENT OPPORTUNITY SFU CAMPS HEAD INSTRUCTOR GLEE CAMPS POSITION) and supervise recreational activities daily. · Evaluate instructors and volunteers as discussed in staff the allocated budget. · Additional responsibilities as directed by the Summer Camps Programmer and Recreation

Kavanagh, Karen L.

427

Beam Head Erosion in Self-Ionized Plasma Wakefield Accelerators  

SciTech Connect (OSTI)

In the recent plasma wakefield accelerator experiments at SLAC, the energy of the particles in the tail of the 42 GeV electron beam were doubled in less than one meter [1]. Simulations suggest that the acceleration length was limited by a new phenomenon--beam head erosion in self-ionized plasmas. In vacuum, a particle beam expands transversely in a distance given by {beta}*. In the blowout regime of a plasma wakefield [2], the majority of the beam is focused by the ion channel, while the beam head slowly spreads since it takes a finite time for the ion channel to form. It is observed that in self-ionized plasmas, the head spreading is exacerbated compared to that in pre-ionized plasmas, causing the ionization front to move backward (erode). A simple theoretical model is used to estimate the upper limit of the erosion rate for a bi-gaussian beam by assuming free expansion of the beam head before the ionization front. Comparison with simulations suggests that half this maximum value can serve as an estimate for the erosion rate. Critical parameters to the erosion rate are discussed.

Berry, M.K.; Blumenfeld, I.; Decker, F.J.; Hogan, M.J.; Ischebeck, R.; Iverson, R.H.; Kirby, N.A.; Siemann, Robert H.; Walz, D.R.; /SLAC; Clayton, C.E.; Huang, C.; Joshi, C.; Lu, W.; Marsh, K.A.; Mori, W.B.; Zhou, M.; /UCLA; Katsouleas, T.C.; Muggli, P.; Oz, E.; /Southern California U.

2008-01-28T23:59:59.000Z

428

Recto Running Head 1 Available Potential Energy and Exergy in  

E-Print Network [OSTI]

Recto Running Head 1 Available Potential Energy and Exergy in Stratified Fluids R�emi Tailleux, thermodynamic efficiencies, buoyancy forcing. Abstract Lorenz's theory of available potential energy (APE) remains the main framework for studying the atmospheric and oceanic energy cycles. Because the APE

Tailleux, Remi

429

Brief Communications Optic Flow Stimuli Update Anterodorsal Thalamus Head  

E-Print Network [OSTI]

orientation in the yaw plane relative to environmental landmark cues. Head movements provoke optic field flow)istheonlyknownprojectionofheaddirectioninformationtoentorhinalgridcellsandhippocampalplacecells,yawplaneoptic flow signals likely influence representations in this spatial reference coordinate system to the body, independently of the ani- mal's ongoing behavior and of its spatial location. The HD cell system

Arleo, Angelo

430

Effects of Head Movement on Perceptions of Humanoid Robot Behavior  

E-Print Network [OSTI]

Effects of Head Movement on Perceptions of Humanoid Robot Behavior Emily Wang Constantine Lignos@cs.yale.edu ABSTRACT This paper examines human perceptions of humanoid robot behavior, specifically how perception to the lab to "play with Nico," an upper-torso humanoid robot. The follow-up survey asked subjects to rate

Plotkin, Joshua B.

431

Anna Head West Student Housing Construction starts Sept. 27  

E-Print Network [OSTI]

to offices in the Anna Head buildings, as well as additional lights, a UCPD "blue phone", and security on the south side of the street are relocated underground. The utilities work will focus on moving the power will remain open. * The sidewalk on Haste Street will be closed adjacent to the site. Pedestrians

Hellerstein, Joseph M.

432

Head-Tail Modes for Strong Space Charge  

SciTech Connect (OSTI)

Head-tail modes are described here for the space charge tune shift significantly exceeding the synchrotron tune. General equation for the modes is derived. Spatial shapes of the modes, their frequencies, and coherent growth rates are explored. The Landau damping rates are also found. Suppression of the transverse mode coupling instability by the space charge is explained.

Burov, Alexey

2008-12-01T23:59:59.000Z

433

Simultaneous multi-headed imager geometry calibration method  

DOE Patents [OSTI]

A method for calibrating multi-headed high sensitivity and high spatial resolution dynamic imaging systems, especially those useful in the acquisition of tomographic images of small animals. The method of the present invention comprises: simultaneously calibrating two or more detectors to the same coordinate system; and functionally correcting for unwanted detector movement due to gantry flexing.

Tran, Vi-Hoa (Newport News, VA); Meikle, Steven Richard (Penshurst, AU); Smith, Mark Frederick (Yorktown, VA)

2008-02-19T23:59:59.000Z

434

Computational Modeling of Brain Dynamics during Repetitive Head Motions  

E-Print Network [OSTI]

Computational Modeling of Brain Dynamics during Repetitive Head Motions Igor Szczyrba School motions in traumatic scenarios that are as- sociated with severe brain injuries. Our results are based on the linear Kelvin-Voigt brain injury model, which treats the brain matter as a viscoelastic solid, and on our

Burtscher, Martin

435

UNITED STATES: NOAA Head Vows to Protect Marine Re-  

E-Print Network [OSTI]

Flshmg Off U. West Coas Saury Flshing f U.. to Be R duced Sharply Resume Canned-Tuna Sales to U.S. 1971 for FISh Culture Flshery Aid Mlssion to VISit 'Thlrd World' ·'ev; ·'lchlro Head Stresses 'Systematiza- tion

436

Running Head: TESTOSTERONE AND POWER Testosterone and power  

E-Print Network [OSTI]

Running Head: TESTOSTERONE AND POWER Testosterone and power Steven J. Stanton and Oliver C. Schultheiss University of Michigan, Ann Arbor, MI, USA To appear in: K. Dowding (Ed.), Encyclopedia of power-647-9440, email: stantons@umich.edu #12;Testosterone and power 2 Across many studies in humans, two functional

Schultheiss, Oliver C.

437

Modeling Interactions of the Rat's Place and Head Direction Systems  

E-Print Network [OSTI]

Modeling Interactions of the Rat's Place and Head Direction Systems A. David Redish and David S in a set of experiments by Sharp et al. (1990). 1 The Sharp et al., 1990 experiment Rats spent multiple sessions finding food scattered randomly on the floor of a black cylin­ drical arena with a white cue card

Touretzky, David S.

438

IMAGINED TRANSFORMATIONS 1 Running head: IMAGINED TRANSFORMATION OF BODIES  

E-Print Network [OSTI]

IMAGINED TRANSFORMATIONS 1 Running head: IMAGINED TRANSFORMATION OF BODIES Imagined Transformations TRANSFORMATIONS 2 Abstract A number of spatial reasoning problems can be solved by performing an imagined transformation of one's egocentric perspective. A series of experiments were carried out to characterize

Zacks, Jeffrey M.

439

The effect of stone retention walls on soil productivity and crop performance on selected hillside farms in southern Honduras  

E-Print Network [OSTI]

THE EFFECT OF STONE RETENTION WALLS ON SOIL PRODUCTIVITY AND CROP PERFORMANCE ON SELECTED HILLSIDE FARMS IN SOUTHERN HONDURAS A Thesis by MARC ELLERY THOMPSON Submitted to the Office of Graduate Studies of Texas A&M University in partial... fulfillment of the requirements for the degree of MASTER OF SCIENCE December 1992 Major Subject Soil Science THE EFFECT OF STONE RETENTION WALLS ON SOIL PRODUCTIVITY AND CROP PERFORMANCE ON SELECTED HILLSIDE FARMS IN SOUTHERN HONDURAS A Thesis by MARC...

Thompson, Marc Ellery

1992-01-01T23:59:59.000Z

440

Implementing multi-step chemical kinetics models in opposed-flow flame spread over cellulose and a comparison to single-step chemistry  

SciTech Connect (OSTI)

Multi-step, gas-phase chemical kinetics are introduced into flame spread modeling efforts. An unsteady multi-step, gas-phase kinetics model both with and without steady-state species assumptions, and including nonunit Lewis number, is compared with a model including a single, finite-rate gas-phase reaction, which has been the usual approach in flame spread modeling. Laminar diffusion flames over a thin fuel in an opposing O{sub 2}/N{sub 2} flow are considered with the solution in two-dimensional space of momentum, energy, and 12 gas-phase species. Results for the multi-step models show detailed flame structure in terms of species and heat release distributions throughout the flame and the role of chemical kinetics as a controlling mechanism in flame spread. Of particular interest is the potential of multi-step chemical kinetics in solutions at near-extinction limit conditions. While the incorporation of nonunit Le alone affords more detailed species transport, in high opposing flows it was found to give only minor structural differences form the single-step unit Le model. The multi-step chemistry allows for the gas kinetics to be self-adjusting to environmental conditions. As a result, the distribution of endothermicity and exothermicity throughout the flame and for particular reversible reactions is found to be a function of the flow environment, which overcomes a major drawback of single-step models, namely a fixed heat of combustion independent of environmental conditions, or one that must be determined separately from the model itself.

Wolverton, M.K.; Altenkirch, R.A.; Tang, L. [Mississippi State Univ., MS (United States)] [Mississippi State Univ., MS (United States)

1999-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "flame retention head" 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

Fluorine-supported flames ignited by a pulsed CO2 laser  

Science Journals Connector (OSTI)

The chemistry accompanying pulsed CO2 laser irradiation of fuel—SF6 mixtures was examined using time-integrated visible emission spectroscopy and analysis of the IR absorption spectra of end products. Under suitable conditions of laser energy, gas pressure, mixture ratio and cell geometry, the visible luminescence exhibits characteristics of fluorine-supported flames. Similar emission has been observed in irradiated fuel—S2F10 mixtures. An analysis of ignition delay versus absorbed laser energy is presented for CH4?SF6 mixtures; it accounts for fluence-dependent absorption by these mixtures and models the effects of hydrodynamic motion on the initial pressure, density and temperature profiles in the samples using a computer code for two-dimensional wave propagation. Many of the IR absorption data are consistent with a reaction mechanism involving the formation of small hydrocarbon intermediates followed by efficient hydrogen abstraction to generate end products such as CS2, CF4 and C2F4. Mechanisms for reaction initiation are discussed.

Wayne M. Trott

1984-01-01T23:59:59.000Z

442

E-Print Network 3.0 - actin-bound myosin heads Sample Search...  

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

Summary: of actin-bound myosin heads in spin-labeled myofibrils in the presence of the ATP analogs AMPPNP (5... -Si have demonstrated that actin-bound myosin heads are...

443

Study on head instability using Flying-QST tester for HDDs  

Science Journals Connector (OSTI)

We developed a tester consisting of minor-loop and major-loop quasi-static test (QST) units in order to better understand head instabilities under conditions where the head slider was flying on the disk. The mino...

Masaru Furukawa; Junguo Xu; Yukio Kato; Tatsuhiko Wada

2013-09-01T23:59:59.000Z

444

Application of Rarefied Gas Dynamics to the Head-Disk Interface in Hard Disk Drives  

E-Print Network [OSTI]

of a magnetic disk and a thermal flying height control (TFC)gration on the flying head slider at the head-disk interfaceThermal flying-height control sliders in hard disk drives

Liu, Nan

2010-01-01T23:59:59.000Z

445

Dr. Martin Wolf, Ph. D Head of Biomedical Optics Research Laboratory  

E-Print Network [OSTI]

and oxygenation of the brain and muscle. Since 2002 he heads the Biomedical Optics Research LaboratoryDr. Martin Wolf, Ph. D Head of Biomedical Optics Research Laboratory Clinic of Neonatology

Zanibbi, Richard

446

A representation of changing heading direction in human cortical areas pVIP and CSv  

E-Print Network [OSTI]

Running title: Changing heading direction in the human brain Keywords: egomotion; f1 A representation of changing heading direction in human cortical in the environment, we continually change direction. Much work has examined how the brain

Royal Holloway, University of London

447

Real World Demonstration of a New American Low-Head Hydropower...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Real World Demonstration of a New American Low-Head Hydropower Unit Real World Demonstration of a New American Low-Head Hydropower Unit Real World Demonstration of a New American...

448

Model 923-B Mouse Gas Anesthesia Head Holder Adaptor Adjustment Features  

E-Print Network [OSTI]

Model 923-B Mouse Gas Anesthesia Head Holder Adaptor Adjustment Features Dorsal/Ventral dial.352.3139 Toll Free: 1.877.352.3275 ^^ci&ion Q)e&i^n^^^r ^esea/H^/i Model 923-B Mouse Gas Anesthesia Head Holder 923B-1/07 #12;MODEL 923-B MOUSE GAS ANESTHESIA HEAD HOLDER The KOPF Mouse Gas Anesthesia Head Holder

Kleinfeld, David

449

Improvement of the effectiveness of spillway operation of high-head hydroelectric stations  

Science Journals Connector (OSTI)

1. The distance of deflection of a high-head aerated flow being discharged from spillways decreases in proportio...

P. R. Khlopenkov

1987-04-01T23:59:59.000Z

450

Volume Currents in Forward and Inverse MEG Simulations Using Realistic Head Models  

E-Print Network [OSTI]

Volume Currents in Forward and Inverse MEG Simulations Using Realistic Head Models Robert Van of magnetoencephalographic (MEG) forward or inverse sim­ ulations in realistic head models. We verify the accuracy, in an inhomogeneous, non­spherical realistic head model, the magnetic field normal to the MEG detector due to volume

Utah, University of

451

Modeling Attractor Deformation in the Rodent Head-Direction JEREMY P. GOODRIDGE1  

E-Print Network [OSTI]

Modeling Attractor Deformation in the Rodent Head-Direction System JEREMY P. GOODRIDGE1 AND DAVID S attractor deformation in the rodent head-direction system. J Neurophysiol 83: 3402­3410, 2000. We present a model of the head-direction circuit in the rat that improves on earlier models in several respects

Touretzky, David S.

452

NEURAL MODELS OF HEAD-DIRECTION CELLS PETER ZEIDMAN JOHN A. BULLINARIA  

E-Print Network [OSTI]

We have seen that navigation requires knowledge of heading, and that HD cells in the brain actNEURAL MODELS OF HEAD-DIRECTION CELLS PETER ZEIDMAN JOHN A. BULLINARIA School of Computer Science background of Head Direction Cells, and existing models of them, we introduce an improved neural model

Bullinaria, John

453

Volume Currents in Forward and Inverse Magnetoencephalographic Simulations Using Realistic Head Models  

E-Print Network [OSTI]

Volume Currents in Forward and Inverse Magnetoencephalographic Simulations Using Realistic Head of magnetoencephalographic MEG forward or in- verse simulations in realistic head models. We verify the accu- racy of our, in an inhomoge- neous, nonspherical realistic head model, the magnetic field normal to the MEG detector due

Utah, University of

454

Double-ring network model of the head-direction system Xiaohui Xie,1,  

E-Print Network [OSTI]

Double-ring network model of the head-direction system Xiaohui Xie,1, * Richard H. R. Hahnloser,1,2 and H. Sebastian Seung1,2 1 Department of Brain and Cognitive Sciences, Massachusetts Institute 2002; published 9 October 2002 In the head-direction system, the orientation of an animal's head

Xie, Xiaohui Sunney

455

Dimpled/grooved face on a fuel injection nozzle body for flame stabilization and related method  

DOE Patents [OSTI]

A fuel injection head for a fuel nozzle used in a gas turbine combustor includes a substantially hollow body formed with an upstream end face, a downstream end face and a peripheral wall extending therebetween. A plurality of pre-mix tubes or passages extend axially through the hollow body with inlets at the upstream end face and outlets at the downstream end face. An exterior surface of the downstream end face is formed with three-dimensional surface features that increase a total surface area of the exterior surface as compared to a substantially flat, planar downstream end face.

Uhm, Jong Ho; Johnson, Thomas Edward; Kim, Kwanwoo; Zuo, Baifang

2013-08-20T23:59:59.000Z

456

SUMMARY OF FY11 SULFATE RETENTION STUDIES FOR DEFENSE WASTE PROCESSING FACILITY GLASS  

SciTech Connect (OSTI)

This report describes the results of studies related to the incorporation of sulfate in high level waste (HLW) borosilicate glass produced at the Savannah River Site (SRS) Defense Waste Processing Facility (DWPF). A group of simulated HLW glasses produced for earlier sulfate retention studies was selected for full chemical composition measurements to determine whether there is any clear link between composition and sulfate retention over the compositional region evaluated. In addition, the viscosity of several glasses was measured to support future efforts in modeling sulfate solubility as a function of predicted viscosity. The intent of these studies was to develop a better understanding of sulfate retention in borosilicate HLW glass to allow for higher loadings of sulfate containing waste. Based on the results of these and other studies, the ability to improve sulfate solubility in DWPF borosilicate glasses lies in reducing the connectivity of the glass network structure. This can be achieved, as an example, by increasing the concentration of alkali species in the glass. However, this must be balanced with other effects of reduced network connectivity, such as reduced viscosity, potentially lower chemical durability, and in the case of higher sodium and aluminum concentrations, the propensity for nepheline crystallization. Future DWPF processing is likely to target higher waste loadings and higher sludge sodium concentrations, meaning that alkali concentrations in the glass will already be relatively high. It is therefore unlikely that there will be the ability to target significantly higher total alkali concentrations in the glass solely to support increased sulfate solubility without the increased alkali concentration causing failure of other Product Composition Control System (PCCS) constraints, such as low viscosity and durability. No individual components were found to provide a significant improvement in sulfate retention (i.e., an increase of the magnitude necessary to have a dramatic impact on blending, washing, or waste loading strategies for DWPF) for the glasses studied here. In general, the concentrations of those species that significantly improve sulfate solubility in a borosilicate glass must be added in relatively large concentrations (e.g., 13 to 38 wt % or more of the frit) in order to have a substantial impact. For DWPF, these concentrations would constitute too large of a portion of the frit to be practical. Therefore, it is unlikely that specific additives may be introduced into the DWPF glass via the frit to significantly improve sulfate solubility. The results presented here continue to show that sulfate solubility or retention is a function of individual glass compositions, rather than a property of a broad glass composition region. It would therefore be inappropriate to set a single sulfate concentration limit for a range of DWPF glass compositions. Sulfate concentration limits should continue to be identified and implemented for each sludge batch. The current PCCS limit is 0.4 wt % SO{sub 4}{sup 2-} in glass, although frit development efforts have led to an increased limit of 0.6 wt % for recent sludge batches. Slightly higher limits (perhaps 0.7-0.8 wt %) may be possible for future sludge batches. An opportunity for allowing a higher sulfate concentration limit at DWPF may lay lie in improving the laboratory experiments used to set this limit. That is, there are several differences between the crucible-scale testing currently used to define a limit for DWPF operation and the actual conditions within the DWPF melter. In particular, no allowance is currently made for sulfur partitioning (volatility versus retention) during melter processing as the sulfate limit is set for a specific sludge batch. A better understanding of the partitioning of sulfur in a bubbled melter operating with a cold cap as well as the impacts of sulfur on the off-gas system may allow a higher sulfate concentration limit to be established for the melter feed. This approach would have to be taken carefully to ensure that a

Fox, K.; Edwards, T.

2012-05-08T23:59:59.000Z

457

Bay Head, New Jersey: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

Head, New Jersey: Energy Resources Head, New Jersey: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 40.0717828°, -74.0543036° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":40.0717828,"lon":-74.0543036,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

458

Publishing of Three Memoranda for Heads of Agencies  

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

-8-80 -8-80 Vol. 45 No. 175 Pages 59135-59296 e Monday September 8, 1980 Federal Register / Vol. 45, No. 175 Monday, September 8, 1980 / Notices 59189 - -- COUNCIL ON ENVIRONMENTAL QUALITY Publishing of Three Memoranda for Heads of Agencies August 20,1980. The Council on Environmental Quality is publishing three Memoranda for Heads of Agencies. The first memorandum, dated August 11,1980, on Analysis of Impacts on Prime and Unique Agricultural Lands in Implementing the National Environmental Policy Act was developed in cooperation with the Department of Agriculture. It updates and supe asedes the Council's previous memorandum on this subject of August 1970. The second memorandum, dated August 11,1980, requests information on agency agriculatural land policies and

459

Indian Head Park, Illinois: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

Head Park, Illinois: Energy Resources Head Park, Illinois: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 41.7703092°, -87.9022808° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":41.7703092,"lon":-87.9022808,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

460

Owls Head, Maine: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

Owls Head, Maine: Energy Resources Owls Head, Maine: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 44.082303°, -69.0572612° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":44.082303,"lon":-69.0572612,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

Note: This page contains sample records for the topic "flame retention head" 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.


461

MHK Projects/Brough Head Wave Farm | Open Energy Information  

Open Energy Info (EERE)

Brough Head Wave Farm Brough Head Wave Farm < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":5,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"500px","height":"350px","centre":false,"title":"","label":"","icon":"File:Aquamarine-marker.png","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":59.081,"lon":-3.359,"alt":0,"address":"","icon":"http:\/\/prod-http-80-800498448.us-east-1.elb.amazonaws.com\/w\/images\/7\/74\/Aquamarine-marker.png","group":"","inlineLabel":"","visitedicon":""}]}

462

Bear Head Lake, Minnesota: Energy Resources | Open Energy Information  

Open Energy Info (EERE)

Head Lake, Minnesota: Energy Resources Head Lake, Minnesota: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 47.7638457°, -92.1265023° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":47.7638457,"lon":-92.1265023,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

463

New Theory Head to join PPPL | Princeton Plasma Physics Lab  

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

Returning to his Princeton roots: Returning to his Princeton roots: New Theory Head to join PPPL By John Greenwald August 27, 2012 Tweet Widget Facebook Like Google Plus One Amitava Bhattacharjee. (Photo by Kristi Donahue, University of New Hampshire Institute for the Study of Earth, Oceans and Space) Amitava Bhattacharjee. Physicist Amitava Bhattacharjee is returning to his academic roots. He arrives as the new head of the Theory Department at the Princeton Plasma Physics Laboratory (PPPL) on August 27, more than 30 years after completing his doctoral work here. He studied at PPPL from 1977 to 1980 while earning his M. A. and Ph.D. in astrophysical sciences from Princeton University, which runs the Laboratory for the U.S. Department of Energy (DOE). His past came flooding back to Bhattacharjee when he gave a talk at PPPL in

464

Soil Water Retention and Relative Permeability for Full Range of Saturation  

SciTech Connect (OSTI)

Common conceptual models for unsaturated flow often rely on the oversimplified representation of medium pores as a bundle of cylindrical capillaries and assume that the matric potential is attributed to capillary forces only. The adsorptive surface forces are ignored. It is often assumed that aqueous flow is negligible when a soil is near or at the residual water content. These models are successful at high and medium water contents but often give poor results at low water contents. These models do not apply to conditions at which water content is less than the residual water content. We extend the lower bound of existing water-retention functions and conductivity models from residual water content to the oven-dry condition (i.e., zero water content) by defining a state-dependent, residual-water content for a soil drier than a critical value. Furthermore, a hydraulic conductivity model for smooth uniform spheres was modified by introducing a correction factor to describe the film flow-induced hydraulic conductivity for natural porous media. The total unsaturated hydraulic conductivity is the sum of those due to capillary and film flow. The extended retention and conductivity models were verified with six datasets from the literature. Results show that, when the soil is at high and intermediate water content, there is no difference between the un-extended and the extended models; when the soil is at low water content, the un-extended models overestimate the water content but under-estimate the conductivity while the extended models match the retention and conductivity measurements well.

Zhang, Z. F.

2010-09-28T23:59:59.000Z

465

Development of Power-head based Fan Airflow Station  

E-Print Network [OSTI]

Development of Power-head Based Fan Airflow Station Gang Wang Research associate University of Nebraska, Lincoln Mingsheng Liu Professor University of Nebraska, Lincoln Abstract Fan airflow measurement is critical for heating... under partial loads. On the other hand, in most of airflow range, the power curve varies exquisitely. Wang and Liu developed the VFD airflow station to obtain the fan airflow using the power and speed based on the power curve. Both the fan...

Wang, G.; Liu, M.

2005-01-01T23:59:59.000Z

466

F A C U L T Y DIVISION HEAD  

E-Print Network [OSTI]

D Barbara Price, PhD Gregory C. Richter, PhD Priscilla Riggle, PhD Linda Seidel, PhD Mary Shapiro, PhD GreggF A C U L T Y DIVISION HEAD Heinz D. Woehlk, PhD GRADUATE FACULTY Hena Ahmad, PhD Monica Barron, Ph Minch, PhD David Partenheimer, PhD Barry C. Poyner, PhD Alanna Preussner, PhD Arnold Preussner, Ph

Gering, Jon C.

467

Intelligent head-down display design for the smart cockpit  

E-Print Network [OSTI]

overload has become a highly important area of research. One such research program exists at Texas A&M University which deals extensively with the information overload problem through the concept of the "Smart Cue+it". This thesis follows the format of... be directly measured. These state variables include altitude, heading, indicated airspeed, pitch and roll attitude, and turn rate. One significantly beneficial component of the sensor suites is the Global Positioning System (GPS). By integrating GPS...

Branham, Paul Anthony

2012-06-07T23:59:59.000Z

468

Workforce Retention Accomplishments Presentation - Sustainability Assessment of Workforce Well-Being and Mission Readiness  

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

Sustainability Assessment of Workforce Sustainability Assessment of Workforce Well-Being and Mission Readiness Jodi M. Jacobson, Ph.D., University of Maryland 2 Illness and Injury Lost Work Time Generational Divide Recruitment & Retention Competition Retirement & Aging Workforce Health & Well-Being Stress Depression & Anxiety Budget Cuts Technology Talent Management Work/Life Balance Safety Accountability Security Leadership Development Workforce Sustainability Chronic Health Conditions Globalization Critical Skills Shortage Job Skill Re-Alignment Job Transitioning Healthcare Costs YOU ARE NOT ALONE! 3 Indirect Costs  "You can"t manage what you can"t measure" (Dr. Ron Goetzel, Director, Institute for Health & Productivity Studies, Cornell University)

469

Retention of neptunium in uranyl alteration phases formed during spent fuel corrosion  

SciTech Connect (OSTI)

Uranyl oxide hydrate phases are known to form during contact of oxide spent nuclear fuel with water under oxidizing conditions; however, less is known about the fate of fission and neutron capture products during this alteration. We describe, the first time, evidence that neptunium can become incorporated into the uranyl secondary phase, dehydrated schoepite (UO{sub 3}{lg_bullet}0.8H{sub 2}O). Based on the long-term durability of natural schoepite, the retention of neptunium in this alteration phase may be significant during spent fuel corrosion in an unsaturated geologic repository.

Buck, E.C.; Finch, R.J.; Finn, P.A.; Bates, J.K.

1997-10-01T23:59:59.000Z

470

Axial thermal medium delivery tubes and retention plates for a gas turbine rotor  

DOE Patents [OSTI]

In a multi-stage turbine rotor, tubes are disposed in openings adjacent the rotor rim for flowing a thermal medium to rotor buckets and returning spent thermal medium. The tubes have axially spaced lands of predetermined wall thickness with thin-walled tube sections between the lands and of increasing thickness from the forward to the aft ends of the tubes. A pair of retention plates are carried on the aft end face of the aft wheel and straddle the tube and engage against a shoulder on the tube to preclude displacement of the tube in an aft direction.

Mashey, Thomas Charles (Coxsackie, NY)

2002-01-01T23:59:59.000Z

471

The effect of solids retention time on tertiary ozonation and carbon adsorption of petrochemical wastewaters  

E-Print Network [OSTI]

and biochemical oxygen demands were measured before and after ozaontion as well as the amount of ozone consumed. Non-adsorbable COD was measured and a comparison of ozonized and unozonized wastewater made. BOD concentration rose after ozonation, but decreased... of solids retention time on nonadsorbable COD, with and without ozonation. 39 LIST OF TABLES Table Page Biochemical and chemical oxygen demand data. COD removal and ozone consumption data 21 26 iVon-adsorbable COD data for bio-oxidized effluent. . 3O...

Buys, Ronald Earl

2012-06-07T23:59:59.000Z

472

Shrew response to variable woody debris retention: Implications for sustainable forest bioenergy  

Science Journals Connector (OSTI)

Abstract Shrews are integral components of forest food webs and may rely on downed woody debris to provide microhabitats that satisfy high moisture and metabolic requirements. However, woody biomass harvests glean downed woody debris to use as a bioenergy feedstock. Biomass Harvesting Guidelines (BHGs) provide guidance on the amount and distribution of downed woody debris retained after harvest to ensure ecological sustainability of woody biomass harvesting and limit detrimental effects on wildlife. However, the success of Biomass Harvesting Guidelines at reaching sustainability goals, including conservation of wildlife habitat, has not been tested in an operational setting. Thus, we compared shrew captures among six woody biomass harvesting treatments in pine plantations in North Carolina, USA from April to August 2011–2014 (n = 4) and Georgia, USA from April to August 2011–2013 (n = 4). Treatments included: (1) woody biomass harvest with no BHGs; (2) 15% retention with woody biomass dispersed; (3) 15% retention with woody biomass clustered; (4) 30% retention with woody biomass dispersed; (5) 30% retention with woody biomass clustered; and (6) no woody biomass harvested. We sampled shrews with drift fence arrays and compared relative abundance of shrews among treatments using analysis of variance. Additionally, we used general linear regression models to evaluate the influence of downed woody debris volume and vegetation structure on shrew capture success at each drift fence for species with >100 captures/state/year. In 53,690 trap nights, we had 1,712 shrew captures representing three species, Cryptotis parva, Blarina carolinensis, and Sorex longirostris. We did not detect consistent differences in shrew relative abundance among woody biomass harvest treatments, but relative abundance of all species increased over time as vegetation became established. In North Carolina, total shrew capture success was negatively related to volume of downed woody debris within 50 m of the drift fence array (P = 0.05) in 2013 and positively related to bare groundcover in 2013 (P = 0.02) and 2014 (P < 0.01). In Georgia, total shrew capture success was negatively related to herbaceous groundcover (P < 0.01) and leaf litter groundcover (P = 0.02) and positively related to woody vegetation groundcover (P < 0.01) and vertical vegetation structure (P = 0.03) in 2013. Our results suggest that shrews in our study area were associated more with vegetation characteristics than downed woody debris and that woody biomass harvests may have little influence on shrew abundances in the southeastern United States Coastal Plain.

S.R. Fritts; C.E. Moorman; S.M. Grodsky; D.W. Hazel; J.A. Homyack; C.B. Farrell; S.B. Castleberry

2015-01-01T23:59:59.000Z

473

Evaluation of scalar mixing and time scale models in PDF simulations of a turbulent premixed flame  

SciTech Connect (OSTI)

Numerical simulation results obtained with a transported scalar probability density function (PDF) method are presented for a piloted turbulent premixed flame. The accuracy of the PDF method depends on the scalar mixing model and the scalar time scale model. Three widely used scalar mixing models are evaluated: the interaction by exchange with the mean (IEM) model, the modified Curl's coalescence/dispersion (CD) model and the Euclidean minimum spanning tree (EMST) model. The three scalar mixing models are combined with a simple model for the scalar time scale which assumes a constant C{sub {phi}}=12 value. A comparison of the simulation results with available measurements shows that only the EMST model calculates accurately the mean and variance of the reaction progress variable. An evaluation of the structure of the PDF's of the reaction progress variable predicted by the three scalar mixing models confirms this conclusion: the IEM and CD models predict an unrealistic shape of the PDF. Simulations using various C{sub {phi}} values ranging from 2 to 50 combined with the three scalar mixing models have been performed. The observed deficiencies of the IEM and CD models persisted for all C{sub {phi}} values considered. The value C{sub {phi}}=12 combined with the EMST model was found to be an optimal choice. To avoid the ad hoc choice for C{sub {phi}}, more sophisticated models for the scalar time scale have been used in simulations using the EMST model. A new model for the scalar time scale which is based on a linear blending between a model for flamelet combustion and a model for distributed combustion is developed. The new model has proven to be very promising as a scalar time scale model which can be applied from flamelet to distributed combustion. (author)

Stoellinger, Michael; Heinz, Stefan [Department of Mathematics, University of Wyoming, Laramie, WY (United States)

2010-09-15T23:59:59.000Z

474

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

475

Head–disk interface problems in first-surface near-field optical recording with flying optical head  

Science Journals Connector (OSTI)

Near-field recording (NFR) technology using a flying optical head is applied for high density optical data storage. Diamond-like carbon (DLC) film and PFPE lubricant film are coated on utmost NFR disk to reduce the tribological problems. A contamination at the head–disk interface (HDI), especially on a solid immersion lens (SIL) is observed. The contaminants are composed of dust materials from the surroundings and lubricant materials from a disk surface. The contaminants are supposed to be condensed by heat from a writing laser beam at the HDI. To avoid the contamination problem, a cover-layer is coated and a focal plane moved under the cover-layer from the HDI. First-surface near-field recording configuration can be modified by laminating a cover-layer, which enhances the possibility of a practical application with a media removability function.

Jin-Hong Kim

2008-01-01T23:59:59.000Z

476

Existence State of Bromine as an Indicator of the Source of Brominated Flame Retardants in Indoor Dust  

Science Journals Connector (OSTI)

We used micro XRFS and gas chromatography-high resolution mass spectrometry (GC-HRMS) to elucidate the exsistence state of bromine as an indicator of the source of BFRs in dust samples collected in Japan from households, offices in universities and other institutions, highly flame-retarded facilities which comply with the Fire Service Law of Japan, and the interior of TVs. ... Our recent research also revealed that household products containing more than 0.01% bromine are present in Japanese households (20) and business hotels (21). ...

Go Suzuki; Akiko Kida; Shin-ichi Sakai; Hidetaka Takigami

2009-02-02T23:59:59.000Z

477

Reactor pressure vessel head vents and methods of using the same  

DOE Patents [OSTI]

Internal head vents are usable in nuclear reactors and include piping inside of the reactor pressure vessel with a vent in the reactor upper head. Piping extends downward from the upper head and passes outside of the reactor to permit the gas to escape or be forcibly vented outside of the reactor without external piping on the upper head. The piping may include upper and lowers section that removably mate where the upper head joins to the reactor pressure vessel. The removable mating may include a compressible bellows and corresponding funnel. The piping is fabricated of nuclear-reactor-safe materials, including carbon steel, stainless steel, and/or a Ni--Cr--Fe alloy. Methods install an internal head vent in a nuclear reactor by securing piping to an internal surface of an upper head of the nuclear reactor and/or securing piping to an internal surface of a reactor pressure vessel.

Gels, John L; Keck, David J; Deaver, Gerald A

2014-10-28T23:59:59.000Z

478

Radionuclide Retention Mechanisms in Secondary Waste-Form Testing: Phase II  

SciTech Connect (OSTI)

This report describes the results from laboratory tests performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to evaluate candidate stabilization technologies that have the potential to successfully treat liquid secondary waste stream effluents produced by the Hanford Tank Waste Treatment and Immobilization Plant (WTP). WRPS is considering the design and construction of a Solidification Treatment Unit (STU) for the Effluent Treatment Facility (ETF) at Hanford. The ETF, a multi-waste, treatment-and-storage unit that has been permitted under the Resource Conservation and Recovery Act (RCRA), can accept dangerous, low-level, and mixed wastewaters for treatment. The STU needs to be operational by 2018 to receive secondary liquid waste generated during operation of the WTP. The STU will provide the additional capacity needed for ETF to process the increased volume of secondary waste expected to be produced by WTP. This report on radionuclide retention mechanisms describes the testing and characterization results that improve understanding of radionuclide retention mechanisms, especially for pertechnetate, {sup 99}TcO{sub 4}{sup -} in four different waste forms: Cast Stone, DuraLith alkali aluminosilicate geopolymer, encapsulated fluidized bed steam reforming (FBSR) product, and Ceramicrete phosphate bonded ceramic. These data and results will be used to fill existing data gaps on the candidate technologies to support a decision-making process that will identify a subset of the candidate waste forms that are most promising and should undergo further performance testing.

Um, Wooyong; Valenta, Michelle M.; Chung, Chul-Woo; Yang, Jungseok; Engelhard, Mark H.; Serne, R. Jeffrey; Parker, Kent E.; Wang, Guohui; Cantrell, Kirk J.; Westsik, Joseph H.

2011-09-26T23:59:59.000Z

479

RETENTION AND CHEMICAL SPECIATION OF URANIUM IN A WETLAND ON THE SAVANNAH RIVER SITE  

SciTech Connect (OSTI)

Uranium speciation and retention mechanism onto Savannah River Site (SRS) wetland sediments was studied using batch (ad)sorption experiments, sequential extraction desorption tests and U L{sub 3}-edge X-ray absorption near-edge structure (XANES) spectroscopy of contaminated wetland sediments. U was highly retained by the SRS wetland sediments. In contrast to other similar but much lower natural organic matter (NOM) sediments, significant sorption of U onto the SRS sediments was observed at pH <4 and pH >8. Sequential extraction tests indicated that the U(VI) species were primarily associated with the acid soluble fraction (weak acetic acid extractable) and NOM fraction (Na-pyrophosphate extractable). Uranium L3- edge XANES spectra of the U-retained sediments were nearly identical to that of uranyl acetate. The primary oxidation state of U in these sediments was as U(VI), and there was little evidence that the high sorptive capacity of the sediments could be ascribed to abiotic or biotic reduction to the less soluble U(IV) species. The molecular mechanism responsible for the high U retention in the SRS wetland sediments is likely related to the chemical bonding of U to organic carbon.

Li, D.; CHANG, H.: SEAMAN, J.; Jaffe, P.; Groos, P.; Jiang, D.; Chen, N.; Lin, J.; Arthur, Z.; Scheckel, K.; Kaplan, D.

2013-06-17T23:59:59.000Z

480

Dust Measurement of Two Organophosphorus Flame Retardants, Resorcinol Bis(diphenylphosphate) (RBDPP) and Bisphenol A Bis(diphenylphosphate) (BPA-BDPP), Used as Alternatives for BDE-209  

Science Journals Connector (OSTI)

Dust Measurement of Two Organophosphorus Flame Retardants, Resorcinol Bis(diphenylphosphate) (RBDPP) and Bisphenol A Bis(diphenylphosphate) (BPA-BDPP), Used as Alternatives for BDE-209 ... Resorcinol bis(diphenylphosphate) (RBDPP) and bisphenol A bis(diphenylphosphate) (BPA-BDPP) are two halogen-free organophosphorus flame retardant (PFRs) that are used as an alternative for the decabromodiphenyl ether (Deca-BDE) technical mixture in TV/flatscreen housing and other electronic consumer products. ... In this study, dust samples were collected from various microenvironments in The Netherlands (houses, cars), Greece (houses), and Sweden (apartments, cars, furniture stores, electronics stores) and analyzed for RBDPP and BPA-BDPP. ...

Sicco H. Brandsma; Ulla Sellström; Cynthia A. de Wit; Jacob de Boer; Pim E. G. Leonards

2013-11-21T23:59:59.000Z

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481

Inhibition of splicing and nuclear retention of pre-mRNA by spliceostatin A in fission yeast  

SciTech Connect (OSTI)

Nuclear retention of pre-mRNAs is tightly regulated by several security mechanisms that prevent pre-mRNA export into the cytoplasm. Recently, spliceostatin A, a methylated derivative of a potent antitumor microbial metabolite FR901464, was found to cause pre-mRNA accumulation and translation in mammalian cells. Here we report that spliceostatin A also inhibits splicing and nuclear retention of pre-mRNA in a fission yeast strain that lacks the multidrug resistance protein Pmd1. As observed in mammalian cells, spliceostatin A is bound to components of the SF3b complex in the spliceosome. Furthermore, overexpression of nup211, a homolog of Saccharomyces cerevisiae MLP1, suppresses translation of pre-mRNAs accumulated by spliceostatin A. These results suggest that the SF3b complex has a conserved role in pre-mRNA retention, which is independent of the Mlp1 function.

Lo, Chor-Wai [Chemical Genetics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Department of Biotechnology, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan); Kaida, Daisuke; Nishimura, Shinichi; Matsuyama, Akihisa; Yashiroda, Yoko; Taoka, Hiroshi [Chemical Genetics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Ishigami, Ken; Watanabe, Hidenori [Department of Applied Biological Chemistry, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan); Nakajima, Hidenori [Drug Discovery Research, Fermentation Research Laboratories, Astellas Pharma Inc., 5-2-3 Tokodai, Tsukuba, Ibaraki 300-2698 (Japan); Tani, Tokio [Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Horinouchi, Sueharu [Department of Biotechnology, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan); Yoshida, Minoru [Chemical Genetics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Japan Science and Technology Corporation (JST), CREST Research Project, Kawaguchi, Saitama 332-0012 (Japan)], E-mail: yoshidam@riken.jp

2007-12-21T23:59:59.000Z

482

The Effect of Blocked Versus Random Task Practice Schedules on the Acquisition and Retention of Surgical Skills  

Science Journals Connector (OSTI)

Background When learning multiple tasks, blocked or random training schedules may be used. We assessed the effects of blocked and random schedules on the acquisition and retention of laparoscopic skills. Methods 36 laparoscopy novices were randomized to practice laparoscopic tasks using blocked, random, or no additional training. Participants performed immediate post-tests, followed by retention tests six weeks later. Outcomes included previously validated Fundamentals of Laparoscopic Surgery (FLS) and hand-motion efficiency (HME) scores. Results Both blocked and random groups had significantly higher FLS and HME scores over baseline on post-tests for each task (p<0.05) and higher overall FLS scores than controls on retention tests (p<0.01). No difference was seen between the blocked and random groups in the amount of skill acquired or skill retained. Conclusion Both blocked and random training schedules can be considered as valid training options to allow programs and learners to tailor training to their individual needs.

Justin D. Rivard; Ashley S. Vergis; Bertram J. Unger; Lawrence M. Gillman; Krista M. Hardy; Jason Park

2014-01-01T23:59:59.000Z

483