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1

Dispersed Bubble Reactor For Enhanced Gas-Liquid-Solids ...  

An apparatus to promote gas-liquid contact and facilitate enhanced mass transfer. The dispersed bubble reactor (DBR) operates in the dispersed bubble ...

2

ENGINEERING DEVELOPMENT OF SLURRY BUBBLE COLUMN REACTOR (SBCR)TECHNOLOGY  

SciTech Connect

The major technical objectives of this program are threefold: (1) to develop the design tools and a fundamental understanding of the fluid dynamics of a slurry bubble column 0reactor to maximize reactor productivity, (2) to develop the mathematical reactor design models and gain an understanding of the hydrodynamic fundamentals under industrially relevant process conditions, and (3) to develop an understanding of the hydrodynamics and their interaction with the chemistries occurring in the bubble column reactor. Successful completion of these objectives will permit more efficient usage of the reactor column and tighter design criteria, increase overall reactor efficiency, and ensure a design that leads to stable reactor behavior when scaling up to large diameter reactors.

Bernard A. Toseland, Ph.D

2000-06-01T23:59:59.000Z

3

ENGINEERING DEVELOPMENT OF SLURRY BUBBLE COLUMN REACTOR (SBCR) TECHNOLOGY  

SciTech Connect

The major technical objectives of this program are threefold: (1) to develop the design tools and a fundamental understanding of the fluid dynamics of a slurry bubble column reactor to maximize reactor productivity, (2) to develop the mathematical reactor design models and gain an understanding of the hydrodynamic fundamentals under industrially relevant process conditions, and (3) to develop an understanding of the hydrodynamics and their interaction with the chemistries occurring in the bubble column reactor. Successful completion of these objectives will permit more efficient usage of the reactor column and tighter design criteria, increase overall reactor efficiency, and ensure a design that leads to stable reactor behavior when scaling up to large diameter reactors.

Bernard A. Toseland, Ph.D.

1999-01-01T23:59:59.000Z

4

Jet Drops Produced by Bubbles Bursting at the Surface of Seawater  

Science Conference Proceedings (OSTI)

Several empirical formulas were reported to describe the production of jet drops by bubbles bursting at the surface of seawater; they were, however, based on scanty data. Recent observations of Spiel have provided new data for intermediate-size ...

Jin Wu

2002-11-01T23:59:59.000Z

5

PROGRESS TOWARDS MODELING OF FISCHER TROPSCH SYNTHESIS IN A SLURRY BUBBLE COLUMN REACTOR  

DOE Green Energy (OSTI)

The Hybrid Energy Systems Testing (HYTEST) Laboratory is being established at the Idaho National Laboratory to develop and test hybrid energy systems with the principal objective to safeguard U.S. Energy Security by reducing dependence on foreign petroleum. A central component of the HYTEST is the slurry bubble column reactor (SBCR) in which the gas-to-liquid reactions will be performed to synthesize transportation fuels using the Fischer Tropsch (FT) process. SBCRs are cylindrical vessels in which gaseous reactants (for example, synthesis gas or syngas) is sparged into a slurry of liquid reaction products and finely dispersed catalyst particles. The catalyst particles are suspended in the slurry by the rising gas bubbles and serve to promote the chemical reaction that converts syngas to a spectrum of longer chain hydrocarbon products, which can be upgraded to gasoline, diesel or jet fuel. These SBCRs operate in the churn-turbulent flow regime which is characterized by complex hydrodynamics, coupled with reacting flow chemistry and heat transfer, that effect reactor performance. The purpose of this work is to develop a computational multiphase fluid dynamic (CMFD) model to aid in understanding the physico-chemical processes occurring in the SBCR. Our team is developing a robust methodology to couple reaction kinetics and mass transfer into a four-field model (consisting of the bulk liquid, small bubbles, large bubbles and solid catalyst particles) that includes twelve species: (1) CO reactant, (2) H2 reactant, (3) hydrocarbon product, and (4) H2O product in small bubbles, large bubbles, and the bulk fluid. Properties of the hydrocarbon product were specified by vapor liquid equilibrium calculations. The absorption and kinetic models, specifically changes in species concentrations, have been incorporated into the mass continuity equation. The reaction rate is determined based on the macrokinetic model for a cobalt catalyst developed by Yates and Satterfield [1]. The model includes heat generation due to the exothermic chemical reaction, as well as heat removal from a constant temperature heat exchanger. Results of the CMFD simulations (similar to those shown in Figure 1) will be presented.

Donna Post Guillen; Tami Grimmett; Anastasia M. Gandrik; Steven P. Antal

2010-11-01T23:59:59.000Z

6

SOLAR UPGRADE OF METHANE USING DRY REFORMING IN DIRECT CONTACT BUBBLE REACTOR  

E-Print Network (OSTI)

SOLAR UPGRADE OF METHANE USING DRY REFORMING IN DIRECT CONTACT BUBBLE REACTOR Khalid Al-Ali 1 process of a solar reformer of dry methane reforming was proposed to operate in a temperature range of 600:2:2 fulfills our requirements for the direct contact bubble reactor of the solar reformer, in which a CO2-rich

Recanati, Catherine

7

Design of Slurry Bubble Column Reactors: Novel Technique for Optimum Catalyst Size Selection  

NLE Websites -- All DOE Office Websites (Extended Search)

Slurry Bubble Column Reactors: Novel Technique Slurry Bubble Column Reactors: Novel Technique for Optimum Catalyst Size Selection Opportunity The Department of Energy's National Energy Technology Laboratory (NETL) is seeking licensing partners interested in implementing United States Patent Number 7,619,011 entitled "Design of Slurry Bubble Column Reactors: Novel Technique for Optimum Catalyst Size Selection." Disclosed in this patent is a method to determine the optimum catalyst particle size for application in a fluidized bed reactor, such as a slurry bubble column reactor (SBCR), to convert synthesis gas into liquid fuels. The reactor can be gas-solid, liquid- solid, or gas-liquid-solid. The method considers the complete granular temperature balance based on the kinetic theory of

8

Engineering development of slurry bubble column reactor (SBCR) technology. Quarterly report, January 1--March 31, 1996  

DOE Green Energy (OSTI)

The major technical objectives of this program are threefold: (1) to develop the design tools and a fundamental understanding of the fluid dynamics of a slurry bubble column reactor to maximize reactor productivity; (2) to develop the mathematical reactor design models and gain an understanding of the hydrodynamic fundamentals under industrially relevant process conditions; and (3) to develop an understanding of the hydrodynamics and their interaction with the chemistries occurring in the bubble column reactor. Successful completion of these objectives will permit more efficient usage of the reactor column and tighter design criteria, increase overall reactor efficiency, and ensure a design that leads to stable reactor behavior when scaling up to large diameter reactors. The main part of this report describes tracer studies of slurry bubble column hydrodynamics during methanol synthesis.

Toseland, B.A.; Tischer, R.E.

1997-12-31T23:59:59.000Z

9

COMPUTATIONAL AND EXPERIMENTAL MODELING OF SLURRY BUBBLE COLUMN REACTORS  

Science Conference Proceedings (OSTI)

The objective of this study was to develop a predictive experimentally verified computational fluid dynamics (CFD) model for gas-liquid-solid flow. A three dimensional transient computer code for the coupled Navier-Stokes equations for each phase was developed and is appended in this report. The principal input into the model is the viscosity of the particulate phase which was determined from a measurement of the random kinetic energy of the 800 micron glass beads and a Brookfield viscometer. The details are presented in the attached paper titled ''CFD Simulation of Flow and Turbulence in a Slurry Bubble Column''. This phase of the work is in press in a referred journal (AIChE Journal, 2002) and was presented at the Fourth International Conference on Multiphase Flow (ICMF 2001) in New Orleans, May 27-June 1, 2001 (Paper No. 909). The computed time averaged particle velocities and concentrations agree with Particle Image Velocimetry (PIV) measurements of velocities and concentrations, obtained using a combination of gamma-ray and X-ray densitometers, in a slurry bubble column, operated in the bubbly-coalesced fluidization regime with continuous flow of water. Both the experiment and the simulation show a down-flow of particles in the center of the column and up-flow near the walls and nearly uniform particle concentration. Normal and shear Reynolds stresses were constructed from the computed instantaneous particle velocities. The PIV measurement and the simulation produced instantaneous particle velocities. The PIV measurement and the simulation produced similar nearly flat horizontal profiles of turbulent kinetic energy of particles. To better understand turbulence we studied fluidization in a liquid-solid bed. This work was also presented at the Fourth International Conference on Multiphase Flow (ICMF 2001, Paper No. 910). To understand turbulence in risers, measurements were done in the IIT riser with 530 micron glass beads using a PIV technique. This report summarizes the measurements and simulations completed so far. This work will continue under the sponsorship of the National Science Foundation and Dow Corning Corporation. This phase of the work is part of the DOE/Industry/University Multiphase Fluid Dynamics Research Consortium. Optimization of the LaPorte pilot plant reactor was attempted by rearranging the heat exchangers. The paper accepted for presentation at the Sixth World Congress of Chemical Engineering, Melbourne, Australia, September 23-27, 2001 is a part of this report.

Paul C.K. Lam; Isaac K. Gamwo; Dimitri Gidaspow

2002-05-01T23:59:59.000Z

10

COMPUTATIONAL AND EXPERIMENTAL MODELING OF THREE-PHASE SLURRY-BUBBLE COLUMN REACTOR  

SciTech Connect

Considerable progress has been achieved in understanding three-phase reactors from the point of view of kinetic theory. In a paper in press for publication in Chemical Engineering Science (Wu and Gidaspow, 1999) we have obtained a complete numerical solution of bubble column reactors. In view of the complexity of the simulation a better understanding of the processes using simplified analytical solutions is required. Such analytical solutions are presented in the attached paper, Large Scale Oscillations or Gravity Waves in Risers and Bubbling Beds. This paper presents analytical solutions for bubbling frequencies and standing wave flow patterns. The flow patterns in operating slurry bubble column reactors are not optimum. They involve upflow in the center and downflow at the walls. It may be possible to control flow patterns by proper redistribution of heat exchangers in slurry bubble column reactors. We also believe that the catalyst size in operating slurry bubble column reactors is not optimum. To obtain an optimum size we are following up on the observation of George Cody of Exxon who reported a maximum granular temperature (random particle kinetic energy) for a particle size of 90 microns. The attached paper, Turbulence of Particles in a CFB and Slurry Bubble Columns Using Kinetic Theory, supports George Cody's observations. However, our explanation for the existence of the maximum in granular temperature differs from that proposed by George Cody. Further computer simulations and experiments involving measurements of granular temperature are needed to obtain a sound theoretical explanation for the possible existence of an optimum catalyst size.

Isaac K. Gamwo; Dimitri Gidaspow

1999-09-01T23:59:59.000Z

11

Experimental characterization of slurry bubble-column reactor hydrodynamics  

DOE Green Energy (OSTI)

Sandia`s program to develop, implement, and apply diagnostics for hydrodynamic characterization of slurry bubble column reactors (SBCRs) at industrially relevant conditions is discussed. Gas liquid flow experiments are performed on an industrial scale. Gamma densitometry tomography (GDT) is applied to measure radial variations in gas holdup at one axial location. Differential pressure (DP) measurements are used to calculate volume averaged gas holdups along the axis of the vessel. The holdups obtained from DP show negligible axial variation for water but significant variations for oil, suggesting that the air water flow is fully developed (minimal flow variations in the axial direction) but that the air oil flow is still developing at the GDT measurement location. The GDT and DP gas holdup results are in good agreement for the air water flow but not for the air oil flow. Strong flow variations in the axial direction may be impacting the accuracy of one or both of these techniques. DP measurements are also acquired at high sampling frequencies (250 Hz) and are interpreted using statistical analyses to determine the physical mechanism producing each frequency component in the flow. This approach did not yield the information needed to determine the flow regime in these experiments. As a first step toward three phase material distribution measurements, electrical impedance tomography (EIT) and GDT are applied to a liquid solid flow to measure solids holdup. Good agreement is observed between both techniques and known values.

Shollenberger, K.A.; Torczynski, J.R.; Jackson, N.B.; O`Hern, T.J.

1997-09-01T23:59:59.000Z

12

Experimental techniques for hydrodynamic characterization of multiphase flows in slurry-phase bubble-column reactors  

DOE Green Energy (OSTI)

Slurry-phase bubble-column Fischer-Tropsch (FT) reactors are recognized as one of the more promising technologies for converting synthesis gas from coal into liquid fuel products (indirect liquefaction). However, hydrodynamic effects must be considered when attempting to scale these reactors to sizes of industrial interest. The objective of this program is to facilitate characterization of reactor hydrodynamics by developing and applying noninvasive tomographic diagnostics capable of measuring gas holdup spatial distribution in these reactors.

Torczynski, J.R.; O`Hern, T.J.; Adkins, D.R.; Shollenberger, K.A.; Mondy, L.A.; Jackson, N.B.

1994-09-01T23:59:59.000Z

13

DEVELOPMENT OF A COMPUTATIONAL MULTIPHASE FLOW MODEL FOR FISCHER TROPSCH SYNTHESIS IN A SLURRY BUBBLE COLUMN REACTOR  

DOE Green Energy (OSTI)

The Hybrid Energy Systems Testing (HYTEST) Laboratory is being established at the Idaho National Laboratory to develop and test hybrid energy systems with the principal objective to safeguard U.S. Energy Security by reducing dependence on foreign petroleum. A central component of the HYTEST is the slurry bubble column reactor (SBCR) in which the gas-to-liquid reactions will be performed to synthesize transportation fuels using the Fischer Tropsch (FT) process. SBCRs are cylindrical vessels in which gaseous reactants (for example, synthesis gas or syngas) is sparged into a slurry of liquid reaction products and finely dispersed catalyst particles. The catalyst particles are suspended in the slurry by the rising gas bubbles and serve to promote the chemical reaction that converts syngas to a spectrum of longer chain hydrocarbon products, which can be upgraded to gasoline, diesel or jet fuel. These SBCRs operate in the churn-turbulent flow regime which is characterized by complex hydrodynamics, coupled with reacting flow chemistry and heat transfer, that effect reactor performance. The purpose of this work is to develop a computational multiphase fluid dynamic (CMFD) model to aid in understanding the physico-chemical processes occurring in the SBCR. Our team is developing a robust methodology to couple reaction kinetics and mass transfer into a four-field model (consisting of the bulk liquid, small bubbles, large bubbles and solid catalyst particles) that includes twelve species: (1) CO reactant, (2) H2 reactant, (3) hydrocarbon product, and (4) H2O product in small bubbles, large bubbles, and the bulk fluid. Properties of the hydrocarbon product were specified by vapor liquid equilibrium calculations. The absorption and kinetic models, specifically changes in species concentrations, have been incorporated into the mass continuity equation. The reaction rate is determined based on the macrokinetic model for a cobalt catalyst developed by Yates and Satterfield [1]. The model includes heat generation due to the exothermic chemical reaction, as well as heat removal from a constant temperature heat exchanger. Results of the CMFD simulations (similar to those shown in Figure 1) will be presented.

Donna Post Guillen; Tami Grimmett; Anastasia M. Gribik; Steven P. Antal

2010-09-01T23:59:59.000Z

14

COMPUTATIONAL AND EXPERIMENTAL MODELING OF SLURRY BUBBLE COLUMN REACTORS  

SciTech Connect

The objective if this study was to develop a predictive experimentally verified computational fluid dynamics (CFD) model for gas-liquid-solid flow. A three dimensional transient computer code for the coupled Navier-Stokes equations for each phase was developed. The principal input into the model is the viscosity of the particulate phase which was determined from a measurement of the random kinetic energy of the 800 micron glass beads and a Brookfield viscometer. The computed time averaged particle velocities and concentrations agree with PIV measurements of velocities and concentrations, obtained using a combination of gamma-ray and X-ray densitometers, in a slurry bubble column, operated in the bubbly-coalesced fluidization regime with continuous flow of water. Both the experiment and the simulation show a down-flow of particles in the center of the column and up-flow near the walls and nearly uniform particle concentration. Normal and shear Reynolds stresses were constructed from the computed instantaneous particle velocities. The PIV measurement and the simulation produced instantaneous particle velocities. The PIV measurement and the simulation produced similar nearly flat horizontal profiles of turbulent kinetic energy of particles. This phase of the work was presented at the Chemical Reaction Engineering VIII: Computational Fluid Dynamics, August 6-11, 2000 in Quebec City, Canada. To understand turbulence in risers, measurements were done in the IIT riser with 530 micron glass beads using a PIV technique. The results together with simulations will be presented at the annual meeting of AIChE in November 2000.

Paul Lam; Dimitri Gidaspow

2000-09-01T23:59:59.000Z

15

Processes and catalysts for conducting Fischer-Tropsch synthesis in a slurry bubble column reactor  

DOE Patents (OSTI)

Processes and catalysts are disclosed for conducting Fischer-Tropsch synthesis in a slurry bubble column reactor (SBCR). One aspect of the invention involves the use of cobalt catalysts without noble metal promotion in an SBCR. Another aspect involves using palladium promoted cobalt catalysts in an SBCR. Methods for preparing noble metal promoted catalysts via totally aqueous impregnation and procedures for producing attrition resistant catalysts are also provided. 1 fig.

Singleton, A.H.; Oukaci, R.; Goodwin, J.G.

1999-08-17T23:59:59.000Z

16

Processes and catalysts for conducting fischer-tropsch synthesis in a slurry bubble column reactor  

DOE Patents (OSTI)

Processes and catalysts for conducting Fischer-Tropsch synthesis in a slurry bubble column reactor (SBCR). One aspect of the invention involves the use of cobalt catalysts without noble metal promotion in an SBCR. Another aspect involves using palladium promoted cobalt catalysts in an SBCR. Methods for preparing noble metal promoted catalysts via totally aqueous impregnation and procedures for producing attrition resistant catalysts are also provided.

Singleton, Alan H. (Marshall Township, Allegheny County, PA); Oukaci, Rachid (Allison Park, PA); Goodwin, James G. (Cranberry Township, PA)

1999-01-01T23:59:59.000Z

17

ADVANCED DIAGNOSTIC TECHNIQUES FOR THREE-PHASE SLURRY BUBBLE COLUMN REACTORS(SBCR)  

SciTech Connect

The objectives set for this cooperative project between Washington University (WU), Ohio State University (OSU), and Air Products and Chemicals, Inc. (APCI) to advance the understanding of the Fischer-Tropsch (FT) slurry bubble column reactor hydrodynamics for proper design and scale-up via advanced diagnostic techniques have been accomplished successfully despite the unexpected challenging technical difficulties in implementing the advanced techniques in high pressure stainless steel slurry bubble column. In this work, a detailed review of the aspects of high pressure phenomena of bubbles in liquids and liquid-solids suspension was performed. All the challenging technical problems mentioned above were resolved and the advanced measurement techniques were successfully used in this project. The effects of reactor pressure, superficial gas velocity, solids loading, and liquid physical properties on the overall gas holdup, holdups distribution, recirculation velocity, turbulent parameters, bubble dynamics (size and rise velocity) were investigated via advanced measurement techniques that includes optical probe, Laser Doppler Anemometry (LDA), Computed Tomography (CT), Computer Automated Radioactive Particle Tracking (CARPT). The findings are discussed and analyzed in this report. In attempt to advance the design and scale-up of bubble columns, new correlations have been developed based on a large bank of data collected at a wide range of operating and design conditions. These correlations are for prediction of radial gas holdup profile, axial liquid velocity profile, overall gas holdup based on Neural Network and gas-liquid mass transfer coefficient. Despite the noticeable advances made on FT SBCR as a part of this project, there are still many parameters and challenging issues that need to be further and properly investigated and understood before this technology will be readily used for alternative fuel development technology.

M.H. Al-Dahhan; L.S. Fan; M.P. Dudukovic

2003-08-01T23:59:59.000Z

18

Engineering Development of Slurry Bubble Column Reactor (SBCR) Technology: Final quarterly technical progress no. 2, 1 July - 30 September 1995  

DOE Green Energy (OSTI)

The major technical objectives of this program are threefold: (1) to develop the design tools and a fundamental understanding of the fluid dynamics of a slurry bubble column reactor to maximize reactor productivity, (2) to develop the mathematical reactor design models and gain an understanding of the hydrodynamic fundamentals under industrially relevant process conditions, and (3) to develop an understanding of the hydrodynamics and their interaction with the chemistries occurring in the bubble column reactor. Successful completion of these objectives will permit more efficient usage of the reactor column and tighter design criteria, increase overall reactor efficiency, and ensure a design that leads to stable reactor behavior when scaling up to large diameter reactors.

Toseland, B.A.; Tischer, R.E.

1997-12-31T23:59:59.000Z

19

Hydrodynamic characterization of slurry bubble-column reactors for Fischer-Tropsch synthesis  

DOE Green Energy (OSTI)

In the Fischer-Tropsch approach to indirect liquefaction, slurry bubble-column reactors (SBCRs) are used to convert coal syngas into the desired product. Sandia`s program to develop, implement, and apply diagnostics for hydrodynamic characterization of SBCRs at industrially relevant conditions is discussed.Gas-liquid flow experiments are performed in an industrial-scale stainless steel vessel. Gamma-densitometry tomography (GDT) is applied to make spatially resolved gas holdup measurements. Both water and Drakeol 10 with air sparging are examined at ambient and elevated pressures. Gas holdup increases with gas superficial velocity and pressure, and the GDT values are in good agreement with values from differential pressure (DP) measurements.

Jackson, N.B.; Torczynski, J.R.; Shollenberger, K.A.; O`Hern, T.J.; Adkins, D.R.

1996-08-01T23:59:59.000Z

20

Hydrodynamic models for slurry bubble column reactors. Seventh technical progress report, January--March 1996  

DOE Green Energy (OSTI)

The objective of this investigation is to convert our ``learning gas solid-liquid`` fluidization model into a predictive design model. The IIT hydrodynamic model computes the phase velocities and the volume fractions of gas, liquid and particulate phase. Model verification involves a comparison of these computed velocities and volume fractions to experimental values. A hydrodynamic model for multiphase flows, based on the principles of mass, momentum and energy conservation for each phase, was developed and applied to model gas-liquid, gas-liquid-solid fluidization and gas-solid-solid separation. To simulate the industrial slurry bubble column reactors, a computer program based on the hydrodynamic model was written with modules for chemical reactions (e.g. the synthesis of methanol), phase changes and heat exchangers. In the simulations of gas-liquid two phases flow system, the gas hold-ups, computed with a variety of operating conditions such as temperature, pressure, gas and liquid velocities, agree well with the measurements obtained at Air Products` pilot plant. The hydrodynamic model has more flexible features than the previous empirical correlations in predicting the gas hold-up of gas-liquid two-phase flow systems. In the simulations of gas-liquid-solid bubble column reactors with and without slurry circulation, the code computes volume fractions, temperatures and velocity distributions for the gas, the liquid and the solid phases, as well as concentration distributions for the species (CO, H{sub 2}, CH{sub 3}0H, ... ), after startup from a certain initial state. A kinetic theory approach is used to compute a solid viscosity due to particle collisions. Solid motion and gas-liquid-solid mixing are observed on a color PCSHOW movie made from computed time series data. The steady state and time average catalyst concentration profiles, the slurry height and the rates of methanol production agree well with the measurements obtained at an Air Products` pilot plant.

Gidaspow, D.

1996-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "jet bubbling reactor" 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

DEVELOPMENT OF A COMPUTATIONAL MULTIPHASE FLOW MODEL FOR FISCHER TROPSCH SYNTHESIS IN A SLURRY BUBBLE COLUMN REACTOR  

SciTech Connect

The Hybrid Energy Systems Testing (HYTEST) Laboratory at the Idaho National Laboratory was established to develop and test hybrid energy systems with the principal objective of reducing dependence on imported fossil fuels. A central component of the HYTEST is the slurry bubble column reactor (SBCR) in which the gas-to-liquid reactions are performed to synthesize transportation fuels using the Fischer Tropsch (FT) process. These SBCRs operate in the churn-turbulent flow regime, which is characterized by complex hydrodynamics, coupled with reacting flow chemistry and heat transfer. Our team is developing a research tool to aid in understanding the physicochemical processes occurring in the SBCR. A robust methodology to couple reaction kinetics and mass transfer into a four-field model (consisting of the bulk liquid, small bubbles, large bubbles and solid catalyst particles) consisting of thirteen species, which are CO reactant, H2 reactant, hydrocarbon product, and H2O product in small bubbles, large bubbles, and the bulk fluid plus catalyst is outlined. Mechanistic submodels for interfacial momentum transfer in the churn-turbulent flow regime are incorporated, along with bubble breakup/coalescence and two-phase turbulence submodels. The absorption and kinetic models, specifically changes in species concentrations, have been incorporated into the mass continuity equation. The reaction rate is based on the macrokinetic model for a cobalt catalyst developed by Yates and Satterfield. The model includes heat generation produced by the exothermic chemical reaction, as well as heat removal from a constant temperature heat exchanger. A property method approach is employed to incorporate vapor-liquid equilibrium (VLE) in a robust manner. Physical and thermodynamic properties as functions of changes in both pressure and temperature are obtained from VLE calculations performed external to the CMFD solver. The novelty of this approach is in its simplicity, as well as its accuracy over a specified temperature and pressure range.

Donna Post Guillen; Tami Grimmett; Anastasia M. Gribik; Steven P. Antal

2011-12-01T23:59:59.000Z

22

Method for producing H.sub.2 using a rotating drum reactor with a pulse jet heat source  

DOE Patents (OSTI)

A method of producing hydrogen by an endothermic steam-carbon reaction using a rotating drum reactor and a pulse jet combustor. The pulse jet combustor uses coal dust as a fuel to provide reaction temperatures of 1300.degree. to 1400.degree. F. Low-rank coal, water, limestone and catalyst are fed into the drum reactor where they are heated, tumbled and reacted. Part of the reaction product from the rotating drum reactor is hydrogen which can be utilized in suitable devices.

Paulson, Leland E. (Morgantown, WV)

1990-01-01T23:59:59.000Z

23

Jet Jet Jet Jet  

NLE Websites -- All DOE Office Websites (Extended Search)

protons protons top quark bottom quark muon top quark antiprotons bottom quark low energy muon quark quark - W boson + Jet Jet Jet Jet neutrino W boson particles antiparticles A Top Antitop Quark Event from the D-Zero Detector at Fermilab muon low energy muon Jet Jet Jet Jet particles antiparticles Particles Seen by the D-Zero Detector at Fermilab in a Top Antitop Quark Event. DST LEGO 16-JUL-1996 15:32 Run 92704 Event 14022 9-JUL-1995 13:17 MUON MUON Miss ET ET DST ETA-PHI 4 MUON 1 MISS ET 4 JET (HAD) (EM) D-Zero Detector at Fermi National Accelerator Laboratory Lego Plot CAL+TKS END VIEW 16-JUL-1996 15:33 Run 92704 Event 14022 9-JUL-1995 13:17 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

24

Design of slurry bubble column reactors: novel technique for optimum catalyst size selection contractual origin of the invention  

DOE Patents (OSTI)

A method for determining optimum catalyst particle size for a gas-solid, liquid-solid, or gas-liquid-solid fluidized bed reactor such as a slurry bubble column reactor (SBCR) for converting synthesis gas into liquid fuels considers the complete granular temperature balance based on the kinetic theory of granular flow, the effect of a volumetric mass transfer coefficient between the liquid and the gas, and the water gas shift reaction. The granular temperature of the catalyst particles representing the kinetic energy of the catalyst particles is measured and the volumetric mass transfer coefficient between the gas and liquid phases is calculated using the granular temperature. Catalyst particle size is varied from 20 .mu.m to 120 .mu.m and a maximum mass transfer coefficient corresponding to optimum liquid hydrocarbon fuel production is determined. Optimum catalyst particle size for maximum methanol production in a SBCR was determined to be in the range of 60-70 .mu.m.

Gamwo, Isaac K. (Murrysville, PA); Gidaspow, Dimitri (Northbrook, IL); Jung, Jonghwun (Naperville, IL)

2009-11-17T23:59:59.000Z

25

Incorporation of Reaction Kinetics into a Multiphase, Hydrodynamic Model of a Fischer Tropsch Slurry Bubble Column Reactor  

DOE Green Energy (OSTI)

This paper describes the development of a computational multiphase fluid dynamics (CMFD) model of the Fischer Tropsch (FT) process in a Slurry Bubble Column Reactor (SBCR). The CMFD model is fundamentally based which allows it to be applied to different industrial processes and reactor geometries. The NPHASE CMFD solver [1] is used as the robust computational platform. Results from the CMFD model include gas distribution, species concentration profiles, and local temperatures within the SBCR. This type of model can provide valuable information for process design, operations and troubleshooting of FT plants. An ensemble-averaged, turbulent, multi-fluid solution algorithm for the multiphase, reacting flow with heat transfer was employed. Mechanistic models applicable to churn turbulent flow have been developed to provide a fundamentally based closure set for the equations. In this four-field model formulation, two of the fields are used to track the gas phase (i.e., small spherical and large slug/cap bubbles), and the other two fields are used for the liquid and catalyst particles. Reaction kinetics for a cobalt catalyst is based upon values reported in the published literature. An initial, reaction kinetics model has been developed and exercised to demonstrate viability of the overall solution scheme. The model will continue to be developed with improved physics added in stages.

Donna Guillen, PhD; Anastasia Gribik; Daniel Ginosar, PhD; Steven P. Antal, PhD

2008-11-01T23:59:59.000Z

26

Method of production H/sub 2/ using a rotating drum reactor with a pulse jet heat source  

DOE Patents (OSTI)

A method of producing hydrogen by an endothermic steam-carbon reaction using a rotating drum reactor and a pulse jet combustor. The pulse jet combustor uses coal dust as a fuel to provide reaction temperatures of 1300/degree/ to 1400/degree/F. Low-rank coal, water, limestone and catalyst are fed into the drum reactor where they are heated, tumbled and reacted. Part of the reaction product from the rotating drum reactor is hydrogen which can be utilized in suitable devices. 1 fig.

Paulson, L.E.

1988-05-13T23:59:59.000Z

27

Hydrodynamic models for slurry bubble column reactors. Fourth technical progress report  

DOE Green Energy (OSTI)

The objective of this investigation is to convert our ``learning gas-solid-liquid`` fluidization model into a predictive design model. The IIT hydrodynamic model computes the phase velocities and volume fractions of gas, liquid and particulate phases. Model verification involves a comparison of these computed velocities and volume fractions to experimental values. The simulation of Air Product methanol reactors described in this paper are continuing. Granular temperatures and viscosities have been computed. Preliminary measurements of granular temperatures using the Air Product catalysts were obtained using our CCD camera.

Gidaspow, D.

1995-07-01T23:59:59.000Z

28

Performance and emissions of a catalytic reactor with propane, diesel, and Jet A fuels  

DOE Green Energy (OSTI)

As part of the ERDA-funded Gas Turbine Highway Vehicle Systems project, tests were made to determine the performance and emissions of a catalytic reactor operated with propane, No. 2 diesel, and Jet A fuels. A 12-cm diameter and 16-cm long catalytic reactor using a proprietary noble metal catalyst was operated at an inlet temperature of 800 K, a pressure of 3 x 10/sup 5/ Pa and reference velocities of 10 to 15 m/s. No significant differences between the performance of the three fuels were observed when 98.5% purity propane was used. The combustion efficiency for 99.8% purity propane tested later was significantly lower, however. The diesel fuel contained 135 ppM of bound nitrogen and consequently produced the highest NO/sub x/ emissions of the three fuels. As much as 85% of the bound nitrogen was converted to NO/sub x/. Steady-state emissions goals based on half the most stringent proposed automotive standards were met when the reactor was operated at an adiabatic combustion temperature higher than 1350 K with all fuels except the 99.8% purity propane. With that fuel, a minimum temperature of 1480 K was required.

Anderson, D.N.

1977-01-01T23:59:59.000Z

29

Hydrodynamic models for slurry bubble column reactors. Sixth technical progress report  

DOE Green Energy (OSTI)

The objective of this investigation is to convert the gas-solid-liquid fluidization model into a predictive design model. The IIT hydrodynamic model computes the phase velocities and the volume fractions of gas, liquid and particulate phases. Model verification involves a comparison of these computed velocities and volume fractions to experimental values. This report presents measurements of granular temperature of Air Products catalyst. The report is in the form of a preliminary paper, entitled ``Dynamics of Liquid-Solid Fluidized Beds with Small Catalyst Particles.`` The principal results are as follows: (1) For the liquid-solid system the granular temperature is much smaller than for a corresponding gas-solid system. This may be due to the larger viscosity of the liquid in comparison to air. (2) The collisional viscosity of the catalyst is correspondingly much smaller than that of catalyst particles in the air. (3) The dominant frequency of density oscillations is near two Hertz, as expected for a gas-solid fluidized bed. There exists a link between this low frequency and the high frequency of catalyst particle oscillations. The Air Products fluidized bed reactor is designed to produce methanol and synthetic fuels from synthesis gas.

Gidaspow, D.

1996-01-01T23:59:59.000Z

30

Enhanced boiling heat transfer by submerged, vibration induced jets .  

E-Print Network (OSTI)

??In this analysis, the efficacy of cavitation jets for heat transfer enhancement was demonstrated. The cavitation jet was formed from a cluster of cavitation bubbles… (more)

Tillery, Steven W.

2005-01-01T23:59:59.000Z

31

KINETIC MODELING OF A FISCHER-TROPSCH REACTION OVER A COBALT CATALYST IN A SLURRY BUBBLE COLUMN REACTOR FOR INCORPORATION INTO A COMPUTATIONAL MULTIPHASE FLUID DYNAMICS MODEL  

DOE Green Energy (OSTI)

Currently multi-tubular fixed bed reactors, fluidized bed reactors, and slurry bubble column reactors (SBCRs) are used in commercial Fischer Tropsch (FT) synthesis. There are a number of advantages of the SBCR compared to fixed and fluidized bed reactors. The main advantage of the SBCR is that temperature control and heat recovery are more easily achieved. The SBCR is a multiphase chemical reactor where a synthesis gas, comprised mainly of H2 and CO, is bubbled through a liquid hydrocarbon wax containing solid catalyst particles to produce specialty chemicals, lubricants, or fuels. The FT synthesis reaction is the polymerization of methylene groups [-(CH2)-] forming mainly linear alkanes and alkenes, ranging from methane to high molecular weight waxes. The Idaho National Laboratory is developing a computational multiphase fluid dynamics (CMFD) model of the FT process in a SBCR. This paper discusses the incorporation of absorption and reaction kinetics into the current hydrodynamic model. A phased approach for incorporation of the reaction kinetics into a CMFD model is presented here. Initially, a simple kinetic model is coupled to the hydrodynamic model, with increasing levels of complexity added in stages. The first phase of the model includes incorporation of the absorption of gas species from both large and small bubbles into the bulk liquid phase. The driving force for the gas across the gas liquid interface into the bulk liquid is dependent upon the interfacial gas concentration in both small and large bubbles. However, because it is difficult to measure the concentration at the gas-liquid interface, coefficients for convective mass transfer have been developed for the overall driving force between the bulk concentrations in the gas and liquid phases. It is assumed that there are no temperature effects from mass transfer of the gas phases to the bulk liquid phase, since there are only small amounts of dissolved gas in the liquid phase. The product from the incorporation of absorption is the steady state concentration profile of the absorbed gas species in the bulk liquid phase. The second phase of the model incorporates a simplified macrokinetic model to the mass balance equation in the CMFD code. Initially, the model assumes that the catalyst particles are sufficiently small such that external and internal mass and heat transfer are not rate limiting. The model is developed utilizing the macrokinetic rate expression developed by Yates and Satterfield (1991). Initially, the model assumes that the only species formed other than water in the FT reaction is C27H56. Change in moles of the reacting species and the resulting temperature of the catalyst and fluid phases is solved simultaneously. The macrokinetic model is solved in conjunction with the species transport equations in a separate module which is incorporated into the CMFD code.

Anastasia Gribik; Doona Guillen, PhD; Daniel Ginosar, PhD

2008-09-01T23:59:59.000Z

32

Experimental study of the oxidation of methyl oleate in a jet-stirred reactor  

SciTech Connect

The experimental study of the oxidation of a blend containing n-decane and a large unsaturated ester, methyl oleate, was performed in a jet-stirred reactor over a wide range of temperature covering both low and high temperature regions (550-1100 K), at a residence time of 1.5 s, at quasi atmospheric pressure with high dilution in helium (n-decane and methyl oleate inlet mole fractions of 1.48 x 10{sup -3} and 5.2 x 10{sup -4}) and under stoichiometric conditions. The formation of numerous reaction products was observed. At low and intermediate temperatures, the oxidation of the blend led to the formation of species containing oxygen atoms like cyclic ethers, aldehydes and ketones deriving from n-decane and methyl oleate. At higher temperature, these species were not formed anymore and the presence of unsaturated species was observed. Because of the presence of the double bond in the middle of the alkyl chain of methyl oleate, the formation of some specific products was observed. These species are dienes and esters with two double bonds produced from the decomposition paths of methyl oleate and some species obtained from the addition of H-atoms, OH and HO{sub 2} radicals to the double bond. Experimental results were compared with former results of the oxidation of a blend of n-decane and methyl palmitate performed under similar conditions. This comparison allowed highlighting the similarities and the differences in the reactivity and in the distribution of the reaction products for the oxidation of large saturated and unsaturated esters. (author)

Bax, Sarah; Hakka, Mohammed Hichem; Glaude, Pierre-Alexandre; Herbinet, Olivier; Battin-Leclerc, Frederique [Laboratoire Reactions et Genie des Procedes, Nancy Universite, CNRS, ENSIC, BP 20451, 1 rue Grandville, 54001 Nancy (France)

2010-06-15T23:59:59.000Z

33

Technology development for cobalt F-T catalysts. Topical report No.3, Zirconia promotion of Fischer-Tropsch cobalt catalysts: Behavior in fixed-bed and slurry bubble column reactors  

DOE Green Energy (OSTI)

A series of cobalt-based F-T catalysts supported on alumina and silica were prepared with different loadings of Zr and different sequences of impregnation of Co and Zr. All catalysts were extensively characterized by different methods. The catalysts were evaluated in terms of their activity and selectivity both in fixed bed and slurry bubble column reactors. Addition of ZrO{sub 2} to both Co/SiO{sub 2} and Co/Al{sub 2}O{sub 3} catalysts resulted in at least a twofold increase in the catalyst activity for F-T synthesis in the fixed bed reactor. In the slurry bubble column reactor, a similar promotion effect was observed for the SiO{sub 2}-supported catalysts, while the addition of Zr to a cobalt/alumina catalyst had a less significant effect.

Oukaci, R.; Marcelin, G.; Goodwin, J.G. Jr. [Pittsburgh Univ., PA (United States). Dept. of Chemical and Petroleum Engineering

1995-01-17T23:59:59.000Z

34

HYDRODYNAMIC MODELS FOR SLURRY BUBBLE COLUMN REACTORS. FINAL TECHNICAL REPORT ALSO INCLUDES THE QUARTERLY TECHNICAL REPORT FOR THE PERIOD 01/01/1997 - 03/31/1997.  

DOE Green Energy (OSTI)

The objective of this study is to develop a predictive experimentally verified computational fluid dynamic (CFD) three phase model. It predicts the gas, liquid and solid hold-ups (volume fractions) and flow patterns in the industrially important bubble-coalesced (churn-turbulent) regime. The input into the model can be either particulate viscosities as measured with a Brookfield viscometer or effective restitution coefficient for particles. A combination of x-ray and {gamma}-ray densitometers was used to measure solid and liquid volume fractions. There is a fair agreement between the theory and the experiment. A CCD camera was used to measure instantaneous particle velocities. There is a good agreement between the computed time average velocities and the measurements. There is an excellent agreement between the viscosity of 800 {micro}m glass beads obtained from measurement of granular temperature (random kinetic energy of particles) and the measurement using a Brookfield viscometer. A relation between particle Reynolds stresses and granular temperature was found for developed flow. Such measurement and computations gave a restitution coefficient for a methanol catalyst to be about 0.9. A transient, two-dimensional hydrodynamic model for production of methanol from syn-gas in an Air Products/DOE LaPorte slurry bubble column reactor was developed. The model predicts downflow of catalyst at the walls and oscillatory particle and gas flow at the center, with a frequency of about 0.7 Hertz. The computed temperature variation in the rector with heat exchangers was only about 5 K, indicating good thermal management. The computed slurry height, the gas holdup and the rate of methanol production agree with LaPorte's reported data. Unlike the previous models in the literature, this model computes the gas and the particle holdups and the particle rheology. The only adjustable parameter in the model is the effective particle restitution coefficient.

DIMITRI GIDASPOW

1997-08-15T23:59:59.000Z

35

Bubble diagnostics  

DOE Patents (OSTI)

The present invention is intended as a means of diagnosing the presence of a gas bubble and incorporating the information into a feedback system for opto-acoustic thrombolysis. In opto-acoustic thrombolysis, pulsed laser radiation at ultrasonic frequencies is delivered intraluminally down an optical fiber and directed toward a thrombus or otherwise occluded vessel. Dissolution of the occlusion is therefore mediated through ultrasonic action of propagating pressure or shock waves. A vapor bubble in the fluid surrounding the occlusion may form as a result of laser irradiation. This vapor bubble may be used to directly disrupt the occlusion or as a means of producing a pressure wave. It is desirable to detect the formation and follow the lifetime of the vapor bubble. Knowledge of the bubble formation and lifetime yields critical information as to the maximum size of the bubble, density of the absorbed radiation, and properties of the absorbing material. This information can then be used in a feedback system to alter the irradiation conditions.

Visuri, Steven R. (Livermore, CA); Mammini, Beth M. (Walnut Creek, CA); Da Silva, Luiz B. (Danville, CA); Celliers, Peter M. (Berkeley, CA)

2003-01-01T23:59:59.000Z

36

REVIEW OF EXPERIMENTAL CAPABILITIES AND HYDRODYNAMIC DATA FOR VALIDATION OF CFD BASED PREDICTIONS FOR SLURRY BUBBLE COLUMN REACTORS  

DOE Green Energy (OSTI)

The purpose of this paper is to document the review of several open-literature sources of both experimental capabilities and published hydrodynamic data to aid in the validation of a Computational Fluid Dynamics (CFD) based model of a slurry bubble column (SBC). The review included searching the Web of Science, ISI Proceedings, and Inspec databases, internet searches as well as other open literature sources. The goal of this study was to identify available experimental facilities and relevant data. Integral (i.e., pertaining to the SBC system), as well as fundamental (i.e., separate effects are considered), data are included in the scope of this effort. The fundamental data is needed to validate the individual mechanistic models or closure laws used in a Computational Multiphase Fluid Dynamics (CMFD) simulation of a SBC. The fundamental data is generally focused on simple geometries (i.e., flow between parallel plates or cylindrical pipes) or custom-designed tests to focus on selected interfacial phenomena. Integral data covers the operation of a SBC as a system with coupled effects. This work highlights selected experimental capabilities and data for the purpose of SBC model validation, and is not meant to be an exhaustive summary.

Donna Post Guillen; Daniel S. Wendt

2007-11-01T23:59:59.000Z

37

REVIEW OF EXPERIMENTAL CAPABILITIES AND HYDRODYNAMIC DATA FOR VALIDATION OF CFD-BASED PREDICTIONS FOR SLURRY BUBBLE COLUMN REACTORS  

DOE Green Energy (OSTI)

The purpose of this paper is to document the review of several open-literature sources of both experimental capabilities and published hydrodynamic data to aid in the validation of a Computational Fluid Dynamics (CFD) based model of a slurry bubble column (SBC). The review included searching the Web of Science, ISI Proceedings, and Inspec databases, internet searches as well as other open literature sources. The goal of this study was to identify available experimental facilities and relevant data. Integral (i.e., pertaining to the SBC system), as well as fundamental (i.e., separate effects are considered), data are included in the scope of this effort. The fundamental data is needed to validate the individual mechanistic models or closure laws used in a Computational Multiphase Fluid Dynamics (CMFD) simulation of a SBC. The fundamental data is generally focused on simple geometries (i.e., flow between parallel plates or cylindrical pipes) or custom-designed tests to focus on selected interfacial phenomena. Integral data covers the operation of a SBC as a system with coupled effects. This work highlights selected experimental capabilities and data for the purpose of SBC model validation, and is not meant to be an exhaustive summary.

Donna Post Guillen; Daniel S. Wendt; Steven P. Antal; Michael Z. Podowski

2007-11-01T23:59:59.000Z

38

Dynamic modeling and control of a solid-sorbent CO{sub 2} capture process with two-stage bubbling fluidized bed adsorber reactor  

SciTech Connect

Solid-sorbent-based CO{sub 2} capture processes have strong potential for reducing the overall energy penalty for post-combustion capture from the flue gas of a conventional pulverized coal power plant. However, the commercial success of this technology is contingent upon it operating over a wide range of capture rates, transient events, malfunctions, and disturbances, as well as under uncertainties. To study these operational aspects, a dynamic model of a solid-sorbent-based CO{sub 2} capture process has been developed. In this work, a one-dimensional (1D), non-isothermal, dynamic model of a two-stage bubbling fluidized bed (BFB) adsorber-reactor system with overflow-type weir configuration has been developed in Aspen Custom Modeler (ACM). The physical and chemical properties of the sorbent used in this study are based on a sorbent (32D) developed at National Energy Technology Laboratory (NETL). Each BFB is divided into bubble, emulsion, and cloud-wake regions with the assumptions that the bubble region is free of solids while both gas and solid phases coexist in the emulsion and cloud-wake regions. The BFB dynamic model includes 1D partial differential equations (PDEs) for mass and energy balances, along with comprehensive reaction kinetics. In addition to the two BFB models, the adsorber-reactor system includes 1D PDE-based dynamic models of the downcomer and outlet hopper, as well as models of distributors, control valves, and other pressure-drop devices. Consistent boundary and initial conditions are considered for simulating the dynamic model. Equipment items are sized and appropriate heat transfer options, wherever needed, are provided. Finally, a valid pressure-flow network is developed and a lower-level control system is designed. Using ACM, the transient responses of various process variables such as flue gas and sorbent temperatures, overall CO{sub 2} capture, level of solids in the downcomer and hopper have been studied by simulating typical disturbances such as change in the temperature, flowrate, and composition of the flue gas. To maintain the overall CO{sub 2} capture at a desired level in face of the typical disturbances, two control strategies were considered–a proportional-integral-derivative (PID)-based feedback control strategy and a feedforward-augmented feedback control strategy. Dynamic simulation results show that both the strategies result in unacceptable overshoot/undershoot and a long settling time. To improve the control system performance, a linear model predictive controller (LMPC) is designed. In summary, the overall results illustrate how optimizing the operation and control of carbon capture systems can have a significant impact on the extent and the rate at which commercial-scale capture processes will be scaled-up, deployed, and used in the years to come.

Modekurti, S.; Bhattacharyya, D.; Zitney, S.

2012-01-01T23:59:59.000Z

39

Bubble oscillations and motion under vibration  

E-Print Network (OSTI)

Bubbles under vibration can behave in unusual ways, e.g., moving downward against the force of buoyancy. While the bubble downward motion due to the Bjerknes force is well known at acoustic frequencies close to the bubble resonant frequency, these experiments demonstrate that these effects can be observed at relatively low frequencies as well. Experiments were performed in a thin, quasi-two-dimensional rectangular acrylic box partially filled with 20-cSt PDMS silicone oil with overlying ambient air. The apparatus was subjected to sinusoidal axial vibration that produced breakup of the gas-liquid free surface, producing liquid jets into the air, droplets pinching off from these jets, gas cavities in the liquid from impacts of these droplets, and bubble transport below the interface. Vibration conditions for the attached videos are 280 Hz frequency, 15 g acceleration, and 94 micron peak-to-peak displacement. Behaviors shown in the videos include the following. 1. Free surface breakup into jets and droplets, and...

O'Hern, Tim; Torczynski, John

2011-01-01T23:59:59.000Z

40

THE MATERIALS OF FAST BREEDER REACTORS  

E-Print Network (OSTI)

jet aircraft engines, and nuclear reactor fuel elements. Ancomponents of a nuclear reactor core are susceptible tothe nuclear physics of the thermal and fast neutron reactors

Olander, Donald R.

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "jet bubbling reactor" 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

A Gold Bubble?  

E-Print Network (OSTI)

Financial bubbles make good entertainment. One often reads speculation that a certain stock, commodity, or even housing is in the midst of a price bubble. For stocks, examples often come from initial public offerings (IPOs), the most recent being LinkedIn (see for example [3]), and a large collection of such occurred during the dot com mania around the turn of the century. Part of the problem in deciding whether an asset is experiencing a price bubble is that there is not a widespread understanding of what a bubble actually is, although there is plenty of expressed desire to detect one in real time. Indeed, the President of the Federal Reserve, Ben Bernanke, said during his confirmation hearings in 2009, “It is extraordinarily difficult in real time to know if an asset price is appropriate or not”[1] Commodities are also great examples of alleged price bubbles. A famous example was the oil price increases of 2007/2008. Nobel prize winning economist Paul Krugman wrote in the New York Times that oil prices were not a bubble, and two days later Ben Stein wrote in the same paper that they were. Without a quantitative procedure, experts often have different opinions about the existence of price bubbles. In this regard William Dudley, the President of the New York Federal Reserve, in an interview with Planet Money stated “...what I am proposing is that we try to identify bubbles in real time, try to develop tools to address those bubbles, try to use those tools when appropriate to limit the size of those bubbles and, therefore, try to limit the damage when those bubbles burst. ” [5

Robert A. Jarrow; Younes Kchia; Philip Protter

2011-01-01T23:59:59.000Z

42

Charged Vacuum Bubble Stability  

E-Print Network (OSTI)

A type of scenario is considered where electrically charged vacuum bubbles, formed from degenerate or nearly degenerate vacuua separated by a thin domain wall, are cosmologically produced due to the breaking of a discrete symmetry, with the bubble charge arising from fermions residing within the domain wall. Stability issues associated with wall tension, fermion gas, and Coulombic effects for such configurations are examined. The stability of a bubble depends upon parameters such as the symmetry breaking scale and the fermion coupling. A dominance of either the Fermi gas or the Coulomb contribution may be realized under certain conditions, depending upon parameter values.

J. R. Morris

1998-10-20T23:59:59.000Z

43

The thermodynamics of bubbles  

E-Print Network (OSTI)

This paper outlines those concitions annanded by the laws of thermodynamics for equilibriza betwoen the vapor in a bubble and the surrounding liquid and then employs these concepts with a nucleation theory in an atteapt ...

Clark, John A.

1956-01-01T23:59:59.000Z

44

PARSEC-SCALE IMAGING OF THE RADIO-BUBBLE SEYFERT GALAXY NGC 6764  

Science Conference Proceedings (OSTI)

We have observed the composite active galactic nucleus (AGN)-starburst galaxy NGC 6764 with the Very Long Baseline Array at 1.6 and 4.9 GHz. These observations have detected a 'core-jet' structure and a possible weak counterjet component at 1.6 GHz. The upper limits to the core and jet (1.6-4.9 GHz) spectral index are 0.6 and 0.3, respectively. Taken together with the high brightness temperature of {approx}10{sup 7} K for the core region, the radio emission appears to be coming from a synchrotron jet. At a position angle of {approx}25{sup 0}, the parsec-scale jet seems to be pointing closely toward the western edge of the southern kpc-scale bubble in NGC 6764. A real connection between the parsec- and sub-kpc-scale emission would not only suggest the presence of a curved jet, but also a close link between the AGN jet and the radio bubbles in NGC 6764. We demonstrate that a precessing jet model can explain the radio morphology from parsec to sub-kpc scales, and the model best-fit parameters of jet speed and orientation are fully consistent with the observed jet-to-counterjet surface brightness ratio. The jet however appears to be disrupted on scales of hundreds of parsecs, possibly due to interaction with and entrainment of the interstellar medium gas, which subsequently leads to the formation of bubbles. The jet energetics in NGC 6764 suggest that it would take 12-21 Myr to inflate the (southern) bubble. This timescale corresponds roughly to the starburst episode that took place in NGC 6764 about 15-50 Myr ago, and could be indicative of a close connection between jet formation and the starburst activity in this galaxy.

Kharb, P.; O'Dea, C. P.; Axon, D. J.; Robinson, A. [Department of Physics, Rochester Institute of Technology, Rochester, NY 14623 (United States); Hota, Ananda [Institute of Astronomy and Astrophysics, Academia Sinica, Taiwan (China); Croston, J. H. [School of Physics and Astronomy, University of Southampton (United Kingdom); Hardcastle, M. J. [Centre for Astrophysics Research, University of Hertfordshire (United Kingdom); Kraft, R. P., E-mail: kharb@cis.rit.ed [Harvard Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA (United States)

2010-11-01T23:59:59.000Z

45

Jet Observables Without Jet Algorithms  

E-Print Network (OSTI)

We introduce a new class of event shapes to characterize the jet-like structure of an event. Like traditional event shapes, our observables are infrared/collinear safe and involve a sum over all hadrons in an event, but like a jet clustering algorithm, they incorporate a jet radius parameter and a transverse momentum cut. Three of the ubiquitous jet-based observables---jet multiplicity, summed scalar transverse momentum, and missing transverse momentum---have event shape counterparts that are closely correlated with their jet-based cousins. Due to their "local" computational structure, these jet-like event shapes could potentially be used for trigger-level event selection at the LHC. Intriguingly, the jet multiplicity event shape typically takes on non-integer values, highlighting the inherent ambiguity in defining jets. By inverting jet multiplicity, we show how to characterize the transverse momentum of the n-th hardest jet without actually finding the constituents of that jet. Since many physics applications do require knowledge about the jet constituents, we also build a hybrid event shape that incorporates (local) jet clustering information. As a straightforward application of our general technique, we derive an event-shape version of jet trimming, allowing event-wide jet grooming without explicit jet identification. Finally, we briefly mention possible applications of our method for jet substructure studies.

Daniele Bertolini; Tucker Chan; Jesse Thaler

2013-10-28T23:59:59.000Z

46

Concentrations of Sea-Spray Droplets at Various Wind Velocities: Separating Productions through Bubble Bursting and Wind Tearing  

Science Conference Proceedings (OSTI)

There are two sets of comprehensive measurements of sea spray: de Leeuw and Smith et al. Their data are interpreted to describe similar productions of film and jet drops by bursting bubbles. For measurements of Smith et al., those droplets ...

Jin Wu

2000-01-01T23:59:59.000Z

47

REACTOR  

DOE Patents (OSTI)

A pressurized water reactor in which automatic control is achieved by varying the average density of the liquid moderator-cooiant is patented. Density is controlled by the temperature and power level of the reactor ftself. This control can be effected by the use of either plate, pellet, or tubular fuel elements. The fuel elements are disposed between upper and lower coolant plenum chambers and are designed to permit unrestricted coolant flow. The control chamber has an inlet opening communicating with the lower coolant plenum chamber and a restricted vapor vent communicating with the upper coolant plenum chamber. Thus, a variation in temperature of the fuel elements will cause a variation in the average moderator density in the chamber which directly affects the power level of the reactor.

Roman, W.G.

1961-06-27T23:59:59.000Z

48

Published on Web 10/28/2008 Gas-Phase, Bulk Production of Metal Oxide Nanowires and Nanoparticles Using a Microwave Plasma Jet Reactor  

E-Print Network (OSTI)

We report gas-phase production of metal oxide nanowires (NWs) and nanoparticles (NPs) using direct oxidation of micron-size metal particles in a high-throughput, atmospheric pressure microwave plasma jet reactor. We demonstrate the concept with production of SnO2, ZnO, TiO2, and Al2O3 NWs. The results suggest that the NW production primarily depends upon the starting metal particle size, microwave power, and the gas-phase composition. The resulting NW powders could be separated from the unreacted metal and metal oxide NPs by sonication in 1-methoxy 2-propanol followed by gravity sedimentation. The experiments conducted using higher microwave powers resulted in spherical, unagglomerated, metal oxide NPs. The results obtained using various metal oxides suggest that the mechanism of NW nucleation and growth in the gas phase is similar to that observed in experiments with metal particles supported on substrates. A simplified analysis suggests that the metal powders melt in the plasma primarily with the heat generated from chemical reactions, such as radical recombination and oxidation reactions on the particle surface.

Jeong H. Kim; Rashekhar Pendyala; Boris Chernomordik; Mahendra K. Sunkara

2008-01-01T23:59:59.000Z

49

Shaping Planetary Nebulae by Jets  

E-Print Network (OSTI)

We conduct 2D axisymmetrical hydrodynamical simulations to investigate the interaction of a collimated fast wind (CFW; wide jets) with a spherical AGB wind. The code includes radiative cooling. We find that the shape of the planetary nebula (PN) is sensitive to the exact mass loss history of the AGB wind, and the opening angle of the CFW. Some typical PN morphologies are obtained, but many other observed morphologies seem to require more ingredients than what we assume in our present simulations, e.g., equatorial AGB wind, and ionization and fast wind during the PN phase. The hot bipolar bubble formed by the jets is an X-ray source.

Muhammad Akashi

2007-09-06T23:59:59.000Z

50

CONTINUOUSLY SENSITIVE BUBBLE CHAMBER  

DOE Patents (OSTI)

A radiation detector of the bubble chamber class is described which is continuously sensitive and which does not require the complex pressure cycling equipment characteristic of prior forms of the chamber. The radiation sensitive element is a gas-saturated liquid and means are provided for establishing a thermal gradient across a region of the liquid. The gradient has a temperature range including both the saturation temperature of the liquid and more elevated temperatures. Thus a supersaturated zone is created in which ionizing radiations may give rise to visible gas bubbles indicative of the passage of the radiation through the liquid. Additional means are provided for replenishing the supply of gas-saturated liquid to maintaincontinuous sensitivity.

Good, R.H.

1959-08-18T23:59:59.000Z

51

Mechanisms of gas bubble retention  

Science Conference Proceedings (OSTI)

Retention and episodic release of flammable gases are critical safety concerns regarding double-shell tanks (DSTs) containing waste slurries. Previous investigations have concluded that gas bubbles are retained by the slurry that has settled at the bottom of the DST. However, the mechanisms responsible for the retention of these bubbles are not well understood. In addition, the presence of retained gas bubbles is expected to affect the physical properties of the sludge, but essentially no literature data are available to assess the effect of these bubbles. The rheological behavior of the waste, particularly of the settled sludge, is critical to characterizing the tendency of the waste to retain gas bubbles. The objectives of this study are to elucidate the mechanisms contributing to gas bubble retention and release from sludge such as is in Tank 241-SY-101, understand how the bubbles affect the physical properties of the sludge, develop correlations of these physical properties to include in computer models, and collect experimental data on the physical properties of simulated sludges with bubbles. This report presents a theory and experimental observations of bubble retention in simulated sludge and gives correlations and new data on the effect of gas bubbles on sludge yield strength.

Gauglitz, P.A.; Mahoney, L.A.; Mendoza, D.P.; Miller, M.C.

1994-09-01T23:59:59.000Z

52

Improved vortex reactor system  

DOE Patents (OSTI)

An improved vortex reactor system for affecting fast pyrolysis of biomass and Refuse Derived Fuel (RDF) feed materials comprising: a vortex reactor having its axis vertically disposed in relation to a jet of a horizontally disposed steam ejector that impels feed materials from a feeder and solids from a recycle loop along with a motive gas into a top part of said reactor.

Diebold, James P. (Lakewood, CO); Scahill, John W. (Evergreen, CO)

1995-01-01T23:59:59.000Z

53

Domain Bubbles of Extra Dimensions  

E-Print Network (OSTI)

``Dimension bubbles'' of the type previously studied by Blau and Guendelman [S.K. Blau and E.I. Guendelman, Phys. Rev. D40, 1909 (1989)], which effectively enclose a region of 5d spacetime and are surrounded by a region of 4d spacetime, can arise in a 5d theory with a compact extra dimension that is dimensionally reduced to give an effective 4d theory. These bubbles with thin domain walls can be stabilized against total collapse in a rather natural way by a scalar field which, as in the case with ``ordinary'' nontopological solitons, traps light scalar particles inside the bubble.

J. R. Morris

2002-11-19T23:59:59.000Z

54

4-D Particle Tracking Velocimetry Applied to Gas-Liquid Reactors  

E-Print Network (OSTI)

4-D Particle Tracking Velocimetry Applied to Gas-Liquid Reactors Michael St¨ohr12 , Christoph Garbe bubbles through space and time (4-D) in a liquid container, e.g. in a gas-liquid reactor. The method cameras looking into the gas-liquid reactor. The air bubbles are visualized by light refracted

Garbe, Christoph S.

55

Improved vortex reactor system  

DOE Patents (OSTI)

An improved vortex reactor system is described for affecting fast pyrolysis of biomass and Refuse Derived Fuel (RDF) feed materials comprising: a vortex reactor having its axis vertically disposed in relation to a jet of a horizontally disposed steam ejector that impels feed materials from a feeder and solids from a recycle loop along with a motive gas into a top part of said reactor. 12 figs.

Diebold, J.P.; Scahill, J.W.

1995-05-09T23:59:59.000Z

56

Vortex Formation in Ellipsoidal Thermal Bubbles  

Science Conference Proceedings (OSTI)

The rise of an isolated dry thermal bubble in a quiescent unstratified environment is a prototypical natural convective flow. This study considers the rise of an isolated dry thermal bubble of ellipsoidal shape (elliptical in both horizontal and ...

Alan Shapiro; Katharine M. Kanak

2002-07-01T23:59:59.000Z

57

Gas Bubbles as Oceanographic Tracers  

Science Conference Proceedings (OSTI)

Air bubbles can be used as oceanographic tracers that indicate the strength of a downwelling current by which they are subducted. In a tidal front in the Fraser Estuary, British Columbia, Canada, vertical currents of up to 0.70 m s?1 subduct ...

Burkard Baschek; David M. Farmer

2010-01-01T23:59:59.000Z

58

LRL 25-inch Bubble Chamber  

DOE R&D Accomplishments (OSTI)

The recently completed 25-inch hydrogen bubble chamber combines excellent picture quality with a fast operating cycle. The chamber has a unique optical system and is designed to take several pictures each Bevatron pulse, in conjunction with the Bevatron rapid beam ejection system.

Alvarez, L. W.; Gow, J. D.; Barrera, F.; Eckman, G.; Shand, J.; Watt, R.; Norgren, D.; Hernandez, H. P.

1964-07-08T23:59:59.000Z

59

Novel techniques for slurry bubble column hydrodynamics  

Science Conference Proceedings (OSTI)

The objective of this cooperative research effort between Washington University, Ohio State University and Exxon Research Engineering Company was to improve the knowledge base for scale-up and operation of slurry bubble column reactors for syngas conversion and other coal conversion processes by increased reliance on experimentally verified hydrodynamic models. During the first year (July 1, 1995--June 30, 1996) of this three year program novel experimental tools (computer aided radioactive particle tracking (CARPT), particle image velocimetry (PIV), heat probe, optical fiber probe and gamma ray tomography) were developed and tuned for measurement of pertinent hydrodynamic quantities, such as velocity field, holdup distribution, heat transfer and bubble size. The accomplishments were delineated in the First Technical Annual Report. The second year (July, 1996--June 30, 1997) was spent on further development and tuning of the novel experimental tools (e.g., development of Monte Carlo calibration for CARPT, optical probe development), building up the hydrodynamic data base using these tools and comparison of the two techniques (PIV and CARPT) for determination of liquid velocities. A phenomenological model for gas and liquid backmixing was also developed. All accomplishments were summarized in the Second Annual Technical Report. During the third and final year of the program (July 1, 1997--June 30, 1998) and during the nine months no cost extension, the high pressure facility was completed and a set of data was taken at high pressure conditions. Both PIV, CT and CARPT were used. More fundamental hydrodynamic modeling was also undertaken and model predictions were compared to data. The accomplishments for this period are summarized in this report.

Dudukovic, M.P.

1999-05-14T23:59:59.000Z

60

Bubble Universe Dynamics After Free Passage  

E-Print Network (OSTI)

We consider bubble collisions in single scalar field theories with multiple vacua. Recent work has argued that at sufficiently high impact velocities, collisions between such bubble vacua are governed by 'free passage' dynamics in which field interactions can be ignored during the collision, providing a systematic process for populating local minima without quantum nucleation. We focus on the time period that follows the bubble collision and provide evidence that, for certain potentials, interactions can drive significant deviations from the free-passage bubble profile, thwarting the production of bubbles with different field values.

Pontus Ahlqvist; Kate Eckerle; Brian Greene

2013-10-22T23:59:59.000Z

Note: This page contains sample records for the topic "jet bubbling reactor" 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

Dynamics of quasi-two-dimensional turbulent jets  

E-Print Network (OSTI)

they can provide, jets have been used in various indus- trial applications, such as waste water disposal (Yannopoulos, 2006), chemical reactors (Jirka & Harleman, 1979), or as a means of propulsion (Stanley, Sarkar & Mellado, 2002). In geophysical flows... .1 Introduction The study of turbulent plane jets is relevant to a wide variety of problems where both qualitative and quantitative knowledge of the concentration in time and space of tracers transported by the jet is needed (Kotsovinos, 1975). In many industrial...

Landel, Julien Rémy Dominique Gérard

2012-11-13T23:59:59.000Z

62

Mathematical modeling of Fischer-Tropsch synthesis in an industrial slurry bubble column - article no. A 23  

SciTech Connect

The increase in society's need for fuels and decrease in crude oil resources are important reasons to make more interest for both academic and industry in converting gas to liquids. Fischer-Tropsch synthesis is one of the most attractive methods of Gas-to-Liquids (GTL) processes and the reactor in which, this reaction occurs, is the heart of this process. This work deals with modeling of a commercial size slurry bubble column reactor by two different models, i.e. single bubble class model (SBCM) and double bubble class model (DBCM). The reactor is assumed to work in a churn-turbulent flow regime and the reaction kinetic is a Langmuir-Hinshelwood type. Cobalt-based catalyst is used for this study as it plays an important role in preparing heavy cuts and the higher yield of the liquid products. Parameter sensitivity analysis was carried out for different conditions such as catalyst concentration, superficial gas velocity, H{sub 2} over CO ratio, and column diameter. The results of the SBCM and DBCM revealed that there is no significant difference between single and double bubble class models in terms of temperature, concentration and conversion profiles in the reactor, so the simpler SBCM with less number of model parameters can be a good and reliable model of choice for analyzing the slurry bubble column reactors.

Nasim Hooshyar; Shohreh Fatemi; Mohammad Rahmani [University of Tehran (Iran)

2009-07-01T23:59:59.000Z

63

Author manuscript, published in "8th World Congress of Chemical Engineering, Montréal: Canada (2009)" A SIMPLE GAS-LIQUID MASS TRANSFER JET SYSTEM,  

E-Print Network (OSTI)

Abstract: An original gas-liquid contacting system is proposed, consisting of a pump, an orifice, a vertical tube coaxial to the orifice and an impinging plate. The pump generates a downward vertical liquid jet through the orifice situated above the gas-liquid dispersion level. The two phase jet is directed towards an impinging plate near the bottom of the tank and dispersed in the volume of the liquid. Liquid is withdrawn below the impinging plate and recycled. This reactor may be used for gas-liquid reactions (ie hydrogenations) and also to mix liquids, to disperse particles, to oxygenate waste water etc…. Performances and design rules of this equipment are proposed. Then, the results are compared to performances of bubble columns, stirred tanks, and other academic and industrial jet systems. It is shown that, at a given energy dissipation, this system yields much higher mass transfer densities than a classical stirred tank provided with a Rushton turbine. Finally some suggestions about mass transfer mechanisms and efficiency of dissipated power are given.

Roger Botton; Dominique Cosserat; Souhila Poncin; Gabriel Wild

2009-01-01T23:59:59.000Z

64

A computational study of highly viscous impinging jets  

SciTech Connect

Two commercially-available computational fluid dynamics codes, FIDAP (Fluent, Inc., Lebanon, NH) and FLOW-3D (Flow Science, Inc., Los Alamos, NM), were used to simulate the landing region of jets of highly viscous fluids impinging on flat surfaces. The volume-of-fluid method was combined with finite difference and finite element approaches to predict the jet behavior. Several computational models with varying degrees of physical realism were developed, and the results were compared with experimental observations. In experiments, the jet exhibited several complex behaviors. As soon as it exited the nozzle, the jet began to neck down and become narrower. When it impacted the solid surface, the jet developed an instability near the impact point and buckled to the side. This buckling became a spiraling motion, and the jet spiraled about the impact point. As the jet spiraled around, a cone-shaped pile was build up which eventually became unstable and slumped to the side. While all of these behaviors were occurring, air bubbles, or voids, were being entrapped in the fluid pool. The results obtained from the FLOW-3D models more closely matched the behavior of real jets than the results obtained from /the FIDAP models. Most of the FLOW-3D models predicted all of the significant jet behaviors observed in experiments: necking, buckling, spiraling, slumping, and void entrapment. All of the FIDAP models predicted that the jet would buckle relatively far from the point of impact, whereas the experimentally observed jet behavior indicates that the jets buckle much nearer the impact point. Furthermore, it was shown that FIDAP is incapable of incorporating heat transfer effects into the model, making it unsuitable for this work.

Silva, M.W. [Univ. of Texas, Austin, TX (United States). Dept. of Mechanical Engineering

1998-11-01T23:59:59.000Z

65

BUBBLE MOTION AND SIZE VARIATION DURING THERMAL ...  

Science Conference Proceedings (OSTI)

... For a water-steam system conditions are determined for a stationary bubble in which the effects of buoyancy and thermal migration are balanced. ...

66

Hydrodynamic causes and effects of air bubbles rising in very viscous media  

E-Print Network (OSTI)

Detailed understanding of two-phase gas liquid flows is imperative for developing efficient multi-phase reactors through precise control of mixing and reaction kinetics. The bubble column is a good apparatus for elementary studies of such flows. In the current study experiments are conducted to assess the effect of liquid viscosity on flow dynamics inside a bubble column. Corn oil and water are used as the continuous media, and air was the dispersed media. The objective of this effort is to use the results for a qualitative validation of the numerical simulations.

Ravinuthala, Sharad Chand

2013-01-01T23:59:59.000Z

67

Air entrainment by a plunging jet under intermittent vortex conditions  

E-Print Network (OSTI)

This fluid dynamic video entry to the 2011 APS-DFD Gallery of Fluid Motion details the transient evolution of the free surface surrounding the impact region of a low-viscosity laminar liquid jet as it enters a quiescent pool. The close-up images depict the destabilization and breakup of the annular air gap and the subsequent entrainment of bubbles into the bulk liquid.

Kim, Kevin Jin; Li, Kevin; Kiger, Ken T

2011-01-01T23:59:59.000Z

68

Fluid mechanics of bubble capture by the diving bell spider  

E-Print Network (OSTI)

The water spider, a unique member of its species, is used as inspiration for a bubble capture mechanism. Bubble mechanics are studied in the pursuit of a biomimetic solution for transporting air bubbles underwater. Careful ...

Brooks, Alice (Alice P.)

2010-01-01T23:59:59.000Z

69

Bubbles in the Near-Surface Ocean: Their Various Structures  

Science Conference Proceedings (OSTI)

Air is entrained by breaking waves to produce bubbles. A highly transient macrobubble cloud is first generated under the breaker, with larger bubbles returning sooner to the sea surface. Those remaining smaller bubbles are then dispersed by near-...

Jin Wu

1994-09-01T23:59:59.000Z

70

Optical Measurement of Bubbles: System Design and Application  

Science Conference Proceedings (OSTI)

Affordable high quality charge-coupled device (CCD) video cameras and image processing software are powerful tools for bubble measurements. Because of the wide variation between bubble populations, different bubble measurement systems (BMSs) are ...

Ira Leifer; Gerrit de Leeuw; Leo H. Cohen

2003-09-01T23:59:59.000Z

71

Visualizing Buoyant Burning Bubbles in Type Ia Supernovae at...  

NLE Websites -- All DOE Office Websites (Extended Search)

Burning in Supernovae Buoyant Burning Bubbles in Type Ia Supernovae bubble-s.jpeg Flame ignition in type Ia supernovae leads to isolated bubbles of burning buoyant fluid. As a...

72

Artificial Bubble Cloud Targets for Underwater Acoustic Remote Sensing  

Science Conference Proceedings (OSTI)

This article describes a technique that uses polymer additives to suspend air bubbles to form stable artificial bubble clouds. The results presented include the range of polymer concentrations for an effective bubble suspension; the void fraction,...

Paul A. Hwang; Ronald A. Roy; Lawrence A. Crum

1995-12-01T23:59:59.000Z

73

Air Bubbles Produced by Breaking Wind Waves: A Laboratory Study  

Science Conference Proceedings (OSTI)

Air bubbles produced by breaking wind waves are measured in a laboratory tank to study bubble clouds produced in freshwater under various wind and wave conditions. Vertical entrainment of bubbles and their size compositions are found to be ...

Paul A. Hwang; Y-H. L. Hsu; Jin Wu

1990-01-01T23:59:59.000Z

74

The Effect of Bubbles on Internal Waves  

Science Conference Proceedings (OSTI)

The influence of gas bubbles on the properties of internal waves in a continuously stratified fluid is studied in the framework of a two-dimensional model of a diluted locally monodisperse mixture of an incompressible fluid with gas bubbles. The ...

R. H. J. Grimshaw; K. R. Khusnutdinova

2004-02-01T23:59:59.000Z

75

Control of reactor coolant flow path during reactor decay heat removal  

DOE Patents (OSTI)

An improved reactor vessel auxiliary cooling system for a sodium cooled nuclear reactor is disclosed. The sodium cooled nuclear reactor is of the type having a reactor vessel liner separating the reactor hot pool on the upstream side of an intermediate heat exchanger and the reactor cold pool on the downstream side of the intermediate heat exchanger. The improvement includes a flow path across the reactor vessel liner flow gap which dissipates core heat across the reactor vessel and containment vessel responsive to a casualty including the loss of normal heat removal paths and associated shutdown of the main coolant liquid sodium pumps. In normal operation, the reactor vessel cold pool is inlet to the suction side of coolant liquid sodium pumps, these pumps being of the electromagnetic variety. The pumps discharge through the core into the reactor hot pool and then through an intermediate heat exchanger where the heat generated in the reactor core is discharged. Upon outlet from the heat exchanger, the sodium is returned to the reactor cold pool. The improvement includes placing a jet pump across the reactor vessel liner flow gap, pumping a small flow of liquid sodium from the lower pressure cold pool into the hot pool. The jet pump has a small high pressure driving stream diverted from the high pressure side of the reactor pumps. During normal operation, the jet pumps supplement the normal reactor pressure differential from the lower pressure cold pool to the hot pool. Upon the occurrence of a casualty involving loss of coolant pump pressure, and immediate cooling circuit is established by the back flow of sodium through the jet pumps from the reactor vessel hot pool to the reactor vessel cold pool. The cooling circuit includes flow into the reactor vessel liner flow gap immediate the reactor vessel wall and containment vessel where optimum and immediate discharge of residual reactor heat occurs.

Hunsbedt, Anstein N. (Los Gatos, CA)

1988-01-01T23:59:59.000Z

76

Math of Popping Bubbles in a Foam  

NLE Websites -- All DOE Office Websites (Extended Search)

Math of Popping Math of Popping Bubbles in a Foam Math of Popping Bubbles in a Foam Berkeley Lab researchers mathematically describe the complex evolution and disappearance of foamy bubbles May 9, 2013 | Tags: Hopper, Math & Computer Science Media Contacts: UC Berkeley: Robert Sanders, rsanders@berkeley.edu, (510) 643-6998 Berkeley Lab: Linda Vu, lvu@lbl.gov, (510) 495-2404 Written By Robert Sanders Bubble baths and soapy dishwater, the refreshing head on a beer and the luscious froth on a cappuccino. All are foams, beautiful yet ephemeral as the bubbles pop one by one. Now, two researchers from the Department of Energy's (DOE's) Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California, Berkeley have described mathematically the successive stages in the complex evolution and disappearance of foamy

77

Numerical simulation of jet mixing concepts in Tank 241-SY-101  

SciTech Connect

The episodic gas release events (GRES) that have characterized the behavior of Tank 241-SY-101 for the past several years are thought to result from gases generated by the waste material in it that become trapped in the layer of settled solids at the bottom of the tank. Several concepts for mitigating the GREs have been proposed. One concept involves mobilizing the solid particles with mixing jets. The rationale behind this idea is to prevent formation of a consolidated layer of settled solids at the bottom of the tank, thus inhibiting the accumulation of gas bubbles in this layer. Numerical simulations were conducted using the TEMPEST computer code to assess the viability and effectiveness of the proposed jet discharge concepts and operating parameters. Before these parametric studies were commenced, a series of turbulent jet studies were conducted that established the adequacy of the TEMPEST code for this application. Configurations studied for Tank 241-SY-101 include centrally located downward discharging jets, draft tubes, and horizontal jets that are either stationary or rotating. Parameter studies included varying the jet discharge velocity, jet diameter, discharge elevation, and material properties. A total of 18 simulations were conducted and are reported in this document. The effect of gas bubbles on the mixing dynamics was not included within the scope of this study.

Trent, D.S.; Michener, T.E.

1993-03-01T23:59:59.000Z

78

MAGNETIC TOPOLOGY OF BUBBLES IN QUIESCENT PROMINENCES  

Science Conference Proceedings (OSTI)

We study a polar-crown prominence with a bubble and its plume observed in several coronal filters by the SDO/AIA and in H{alpha} by the MSDP spectrograph in Bialkow (Poland) to address the following questions: what is the brightness of prominence bubbles in EUV with respect to the corona outside of the prominence and the prominence coronal cavity? What is the geometry and topology of the magnetic field in the bubble? What is the nature of the vertical threads seen within prominences? We find that the brightness of the bubble and plume is lower than the brightness of the corona outside of the prominence, and is similar to that of the coronal cavity. We constructed linear force-free models of prominences with bubbles, where the flux rope is perturbed by inclusion of parasitic bipoles. The arcade field lines of the bipole create the bubble, which is thus devoid of magnetic dips. Shearing the bipole or adding a second one can lead to cusp-shaped prominences with bubbles similar to the observed ones. The bubbles have complex magnetic topology, with a pair of coronal magnetic null points linked by a separator outlining the boundary between the bubble and the prominence body. We conjecture that plume formation involves magnetic reconnection at the separator. Depending on the viewing angle, the prominence can appear either anvil-shaped with predominantly horizontal structures, or cusp-shaped with predominantly vertical structuring. The latter is an artifact of the alignment of magnetic dips with respect to the prominence axis and the line of sight.

Dudik, J. [DAPEM, Faculty of Mathematics Physics and Computer Science, Comenius University, Mlynska Dolina F2, 84248 Bratislava (Slovakia); Aulanier, G.; Schmieder, B. [Observatoire de Paris, LESIA, UMR 8109 (CNRS), F-92195 Meudon Principal Cedex (France); Zapior, M. [Astronomical Institute, University of Wroclaw, Kopernika 11, 51622 Wroclaw (Poland); Heinzel, P., E-mail: dudik@fmph.uniba.sk [Astronomical Institute of the Academy of Sciences of the Czech Republic, Fricova 298, 25165 Ondrejov (Czech Republic)

2012-12-10T23:59:59.000Z

79

Diffusive Accumulation of Methane Bubbles in Seabed  

E-Print Network (OSTI)

We consider seabed bearing methane bubbles. In the absence of fractures the bubbles are immovably trapped in a porous matrix by surface tension forces; therefore the dominant mechanism of transfer of gas mass becomes the diffusion of gas molecules through the liquid. The adequate description of this process requires accounting "other-than-normal" (non-Fickian) diffusion effects, thermodiffusion and gravity action. We evaluate the diffusive flux of aqueous methane and predict the possibility of existence of bubble mass accumulation zones (which can appear independently from the presence/absence of hydrate stability zone) and effect of non-Fickian drift on the capacity of shallow and deep methane-hydrate deposits.

Goldobin, D S; Levesley, J; Lovell, M A; Rochelle, C A; Jackson, P; Haywood, A; Hunter, S; Rees, J

2010-01-01T23:59:59.000Z

80

Formation of jet-like spikes from the ablative Rayleigh-Taylor instability  

Science Conference Proceedings (OSTI)

The mechanism of jet-like spike formation from the ablative Rayleigh-Taylor instability (ARTI) in the presence of preheating is reported. It is found that the preheating plays an essential role in the formation of the jet-like spikes. In the early stage, the preheating significantly increases the plasma density gradient, which can reduce the linear growth of ARTI and suppress its harmonics. In the middle stage, the preheating can markedly increase the vorticity convection and effectively reduce the vorticity intensity resulting in a broadened velocity shear layer near the spikes. Then the growth of ablative Kelvin-Helmholtz instability is dramatically suppressed and the ARTI remains dominant. In the late stage, nonlinear bubble acceleration further elongates the bubble-spike amplitude and eventually leads to the formation of jet-like spikes.

Wang, L. F.; Ye, W. H.; He, X. T. [HEDPS and CAPT, Peking University, Beijing 100871 (China); Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Zhang, W. Y. [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Sheng, Z. M. [Key Laboratory for Laser Plasmas (MoE) and Department of Physics, Shanghai Jiaotong University, Shanghai 200240 (China); Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China); Yu, M. Y. [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China); Institute for Theoretical Physics I, Ruhr University, Bochum D-44780 (Germany)

2012-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "jet bubbling reactor" 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

Hypervelocity impact jet formation  

SciTech Connect

The hypervelocity impact of a particle on a surface generates a jet of shocked material which is thrown from the impact site. A simple analytic model has been developed to obtain expressions for the evolution of this jet of ejecta. The analysis is based on applying the conservation equations of mass and momentum to the problem of a normal impact of a sphere against a semi-infinite flat target. Expressions are developed for the evolution of the jet velocity, jet release point and the locus of points which describe the ejecta envelope. These analytical ejecta profiles are compared with high speed photographs of impact jet formation. 6 refs., 7 figs.

Ang, J.A.

1991-01-01T23:59:59.000Z

82

Scattering of Ultra Cold Neutrons on Nano-size Bubbles  

E-Print Network (OSTI)

Inelastic scattering of ultra cold neutrons on bubbles with the size of nanometers is considered. It is shown that neutron-bubble cross section is large and sensitive to different vibration modes of bubbles. This process could be used for study of dynamics of nano-size bubbles and for new methods of ultra cold neutron production.

Vladimir Gudkov

2006-02-07T23:59:59.000Z

83

Large Scale Simulations of Jets in Dense and Magnetised Environments  

E-Print Network (OSTI)

We report two simulations that have been carried out at the SX-5 at HLRS (Stuttgart). One simulation is axisymmetric and purely hydrodynamic, but with a resolution of 20 points per beam-radius (ppb). The bipolar jet is injected in the center of a spherically symmetric King profile, initially underdense to its environment by a factor of 10,000. As expected from our previous work, the jet starts with producing a spherical bubble around it, bounded by the bow shock. The bubble slowly elongates, first with roughly elliptical shape, and then forms narrower extensions in beam direction. The final aspect ratio of the bow shock is 1.8. We have transformed the results on a 3D-rectangular grid and integrated the emission properties to compare the results with observed central cluster radio galaxies. In the particular case of Cygnus A, we come to convincing consistency, morphologically, regarding the size of the influenced region by the jet, size, and cylindrical shape of the radio cocoon, and source age. This strongly supports our earlier hypothesis on the nature of the jet in Cygnus A, and the derived constraints on other jet parameters like a power of $8 \\times 10^{46}$ erg/s and an age of 27 Myr. But, the simulation also clearly shows the shortcoming of the model: The jet's beam is very unstable, reaching the tip of the bow shock only very seldom. Also, the contact discontinuity between shocked beam plasma and shocked ambient gas is quite disrupted by the action of the Kelvin-Helmholtz-instability. This is not seen in observations, and necessitates the presence of dynamically important magnetic fields or an at least moderately relativistic flow, or both. [abridged

Martin G. H. Krause; Max Camenzind

2003-07-08T23:59:59.000Z

84

Searches for charmed particles using bubble chambers  

SciTech Connect

Searches for charm particle production using bubble chambers are summarized. These searches depend on the detection of neutral strange particles. Upper limits are given for the different charmed mass regions and methods of search. (auth)

Harris, R.

1975-10-01T23:59:59.000Z

85

Bubble Behavior in a Taylor Vortex  

E-Print Network (OSTI)

We present an experimental study on the behavior of bubbles captured in a Taylor vortex. The gap between a rotating inner cylinder and a stationary outer cylinder is filled with a Newtonian mineral oil. Beyond a critical ...

Deng, Rensheng

86

Nucleate boiling bubble growth and departure  

E-Print Network (OSTI)

The vapor bubble formation on the heating surface during pool boiling has been studied experimentally. Experiments were made at the atmospheric pressure 28 psi and 40 psi, using degassed distilled water and ethanol. The ...

Staniszewski, Bogumil E.

1959-01-01T23:59:59.000Z

87

Acoustic Energy Storage in Single Bubble Sonoluminescence  

E-Print Network (OSTI)

Single bubble sonoluminescence is understood in terms of a shock focusing towards the bubble center. We present a mechanism for significantly enhancing the effect of shock focusing, arising from the storage of energy in the acoustic modes of the gas. The modes with strongest coupling are not spherically symmetric. The storage of acoustic energy gives a framework for understanding how light intensities depend so strongly on ambient gases and liquids and suggests that the light intensities of successive flashes are highly correlated.

Michael P. Brenner; Sascha Hilgenfeldt; Detlef Lohse; Rodolfo R. Rosales

1996-05-07T23:59:59.000Z

88

The ATLAS jet trigger  

E-Print Network (OSTI)

The ATLAS jet trigger system has a 3-level structure, and was designed based on the concept of Regions Of Interest, where only regions of the detector around interesting Level-1 objects are reconstructed at the higher levels. This philosophy has changed during 2011, and there now exists the possibility to unpacking the full calorimeter at Event Filter. In 2012, full calorimeter unpacking is also available at Level-2, in addition jet energies are now calibrated to jet energy scale, and cleaning cuts are applied to reduce rate spikes. This paper presents the performance of the jet trigger in 2011 and an overview of the new features available for 2012.

Tamsett, M; The ATLAS collaboration

2012-01-01T23:59:59.000Z

89

Jet Mass Spectra in Higgs + One Jet at NNLL  

E-Print Network (OSTI)

The invariant mass of a jet is a benchmark variable describing the structure of jets at the LHC. We calculate the jet mass spectrum for Higgs plus one jet at the LHC at next-to-next-to-leading logarithmic (NNLL) order using a factorization formula. At this order, the cross section becomes sensitive to perturbation theory at the soft m_jet^2/p_T^jet scale. Our calculation is exclusive and uses the 1-jettiness global event shape to implement a veto on additional jets. The dominant dependence on the jet veto is removed by normalizing the spectrum, leaving residual dependence from non-global logarithms depending on the ratio of the jet mass and jet veto variables. For our exclusive jet cross section these non-global logarithms are parametrically smaller than in the inclusive case, allowing us to obtain a complete NNLL result. Results for the dependence of the jet mass spectrum on the kinematics, jet algorithm, and jet size R are given. Using individual partonic channels we illustrate the difference between the jet mass spectra for quark and gluon jets. We also study the effect of hadronization and underlying event on the jet mass in PYTHIA. To highlight the similarity of inclusive and exclusive jet mass spectra, a comparison to LHC data is presented.

Teppo T. Jouttenus; Iain W. Stewart; Frank J. Tackmann; Wouter J. Waalewijn

2013-02-04T23:59:59.000Z

90

SPECIAL TOPIC INTERNATIONAL TOKAMAK REACTOR -  

E-Print Network (OSTI)

(beyond the present generation of large tokamaks) in the world tokamak programme; (2) to assess experiment in the tokamak programme between the present generation of large tokamaks (TFTR, JET, JT-60, T-15 of the development and integration of full-scale components which can be extra- polated to a commercial reactor; (d

Abdou, Mohamed

91

THE DETECTION OF BOILING IN A WATER-COOLED NUCLEAR REACTOR  

SciTech Connect

Measurements made at ORNL to study the feasibility of boiling detection in a water-cooled nuclear reactor are described. The methods selected for the detection of boiling include measurement of the acoustical noise produced by the generation of bubbles and measurement of changes in the reactor-power spectral density produced by bubbles. Preliminary results indicating that both methods could detect boiling are shown. (auth)

Colomb, A.L.; Binford, F.T.

1962-08-17T23:59:59.000Z

92

FastJet user manual  

E-Print Network (OSTI)

FastJet is a C++ package that provides a broad range of jet finding and analysis tools. It includes efficient native implementations of all widely used 2-to-1 sequential recombination jet algorithms for pp and e+e- collisions, as well as access to 3rd party jet algorithms through a plugin mechanism, including all currently used cone algorithms. FastJet also provides means to facilitate the manipulation of jet substructure, including some common boosted heavy-object taggers, as well as tools for estimation of pileup and underlying-event noise levels, determination of jet areas and subtraction or suppression of noise in jets.

Matteo Cacciari; Gavin P. Salam; Gregory Soyez

2011-11-25T23:59:59.000Z

93

Jet production at HERA  

E-Print Network (OSTI)

Recent results from jet production in deep inelastic ep scattering to investigate parton dynamics at low x are reviewed. The results on jet production in deep inelastic scattering and photoproduction used to test perturbative QCD are discussed and the values of alphas(Mz) extracted from a QCD analysis of the data are presented

C. Glasman

2004-10-07T23:59:59.000Z

94

Ideal magnetohydrodynamic simulations of unmagnetized dense plasma jet injection into a hot strongly magnetized plasma  

E-Print Network (OSTI)

We present results from three-dimensional ideal magnetohydrodynamic simulations of unmagnetized dense plasma jet injection into a hot strongly magnetized plasma, with the aim of providing insight into core fueling of a tokamak with parameters relevant for ITER (International Thermonuclear Experimental Reactor) and NSTX (National Spherical Torus Experiment). Unmagnetized jet injection is similar to compact toroid injection but with higher possible injection density and total mass, as well as a potentially smaller footprint for the injector hardware. Our simulation results show that the unmagnetized dense jet is quickly magnetized upon injection. The penetration depth of the jet into the tokamak plasma is mostly dependent on the jet's initial kinetic energy while the jet's magnetic field determines its interior evolution. A key requirement for spatially precise fueling is for the jet's slowing-down time to be less than the time for the perturbed tokamak magnetic flux to relax due to magnetic reconnection. Thus ...

Liu, Wei

2010-01-01T23:59:59.000Z

95

Bubble visualization in a simulated hydraulic jump  

E-Print Network (OSTI)

This is a fluid dynamics video of two- and three-dimensional computational fluid dynamics simulations carried out at St. Anthony Falls Laboratory. A transient hydraulic jump is simulated using OpenFOAM, an open source numerical solver. A Volume of Fluid numerical method is employed with a realizable k-epsilon turbulence model. The goal of this research is to model the void fraction and bubble size in a transient hydraulic jump. This fluid dynamics video depicts the air entrainment characteristics and bubble behavior within a hydraulic jump of Froude number 4.82.

Witt, Adam; Shen, Lian

2013-01-01T23:59:59.000Z

96

Microstructure, morphology and lifetime of armored bubbles exposed to surfactants  

E-Print Network (OSTI)

We report the behavior of particle-stabilized bubbles (armored bubbles) when exposed to various classes and concentrations of surfactants. The bubbles are non-spherical due to the jamming of the particles on the interface and are stable to dissolution prior to the addition of surfactant. We find that the dissolving bubbles exhibit distinct morphological, microstructural, and lifetime changes, which correlate with the concentration of surfactant employed. For low concentrations of surfactant an armored bubble remains non-spherical while dissolving, while for concentrations close to and above the surfactant CMC a bubble reverts to a spherical shape before dissolving. We propose a microstructural interpretation, supported by our experimental observations of particle dynamics on the bubble interface, that recognizes the role of interfacial jamming and stresses in particle stabilization and surfactant-mediated destabilization of armored bubbles.

Anand Bala Subramaniam; Cecile Mejean; Manouk Abkarian; Howard A. Stone

2006-02-16T23:59:59.000Z

97

Compressibility Consideration in the Boundary of a Strongly Collapsing Bubble  

E-Print Network (OSTI)

Equations of radial motion of a gas bubble in a compressible viscous liquid have been modified to account for compressibility at the bubble boundary. It has been done by deriving a new bubble boundary equation. This equation has a new term due to liquid compressibility. The influence of this term in the bubble dynamics has been numerically investigated using isothermal-adiabatic model for the gas bubble evolution. The results clearly indicate that at the end of the collapse the new term has very significant role and its consideration dramatically changes the bubble characteristics. The effect of this term is more prominent for the more intense collapses, so that its consideration scales up the maximum values of gas pressure and gas temperature. We have also reasoned that the new bubble behavior will be established even when the effects of mass (water vapor) exchange, chemical reactions, and gas dynamics inside the bubble are taken into account in the model.

Moshaii, A; Taeibi-Rahni, M; Moshaii, Ahmad; Sadighi-Bonabi, Rasool; Taeibi-Rahni, Mohammad

2003-01-01T23:59:59.000Z

98

Electrical capacitance volume tomography (ECVT) applied to bubbling fluid beds  

SciTech Connect

These presentation visuals illustrate the apparatus and method for applying Electrical Capacitance Volume Tomography (ECVT) to bubbling fluid beds to their solid fraction and bubble properties. Results are compared to estimated values.

Weber, J., Mei, J.

2012-01-01T23:59:59.000Z

99

Stability of a class of neutral vacuum bubbles  

E-Print Network (OSTI)

A model that gives rise to vacuum bubbles is considered where the domain wall field interacts with another real scalar field, resulting in the formation of domain ribbons within the host domain wall. Ribbon-antiribbon annihilations produce elementary bosons whose mass inside the wall is different from the mass in vacuum. Two cases are considered, where the bosons get trapped either within the bubble wall or the bosons get trapped within the vacuum enclosed by the bubble. The bosonic (meta)stabilization effect on the bubble is examined in each case. It is found that when the bosons become trapped within the bubble wall, the stabilization mechanism lasts for only a limited amount of time, and then the bubble undergoes unchecked collapse. However, when the bosons become trapped within the bubble's interior volume, the bubble can be long-lived, provided that it has a sufficiently thin wall.

J. R. Morris

2013-04-16T23:59:59.000Z

100

Bubble Clouds and Langmuir Circulation: Observations and Models  

Science Conference Proceedings (OSTI)

Concurrent measurements of the rate of dissipation of turbulent kinetic energy and the void fraction and size distribution of near-surface bubbles are described. Relatively high dissipation rates and void fractions are found in bubble bands ...

S. A. Thorpe; T. R. Osborn; D. M. Farmer; S. Vagle

2003-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "jet bubbling reactor" 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

Some Factors Affecting the Size Distributions of Oceanic Bubbles  

Science Conference Proceedings (OSTI)

The effects of water temperature, dissolved gas saturation levels, and particulate concentrations on the size distribution of subsurface bubbles are investigated using numerical models. The input of bubbles, either at a constant rate in a “steady-...

S. A. Thorpe; P. Bowyer; D. K. Woolf

1992-04-01T23:59:59.000Z

102

Heart-shaped bubbles rising in anisotropic liquids  

Science Conference Proceedings (OSTI)

This Letter reports on numerical simulations motivated by experimental observations of an unusual inverted-heart shape for bubbles rising in an anisotropicmicellar solution. We explain the bubble shape by assuming that the micelles are aligned into a nematic phase

Chunfeng Zhou; Pengtao Yue; James J. Feng; Chun Liu; Jie Shen

2007-01-01T23:59:59.000Z

103

Progress in the Development of Compressible, Multiphase Flow Modeling Capability for Nuclear Reactor Flow Applications  

Science Conference Proceedings (OSTI)

In nuclear reactor safety and optimization there are key issues that rely on in-depth understanding of basic two-phase flow phenomena with heat and mass transfer. Within the context of multiphase flows, two bubble-dynamic phenomena – boiling (heterogeneous) and flashing or cavitation (homogeneous boiling), with bubble collapse, are technologically very important to nuclear reactor systems. The main difference between boiling and flashing is that bubble growth (and collapse) in boiling is inhibited by limitations on the heat transfer at the interface, whereas bubble growth (and collapse) in flashing is limited primarily by inertial effects in the surrounding liquid. The flashing process tends to be far more explosive (and implosive), and is more violent and damaging (at least in the near term) than the bubble dynamics of boiling. However, other problematic phenomena, such as crud deposition, appear to be intimately connecting with the boiling process. In reality, these two processes share many details.

R. A. Berry; R. Saurel; F. Petitpas; E. Daniel; O. Le Metayer; S. Gavrilyuk; N. Dovetta

2008-10-01T23:59:59.000Z

104

Cometabolic degradation of trichloroethylene in a bubble column bioscrubber  

SciTech Connect

A bubble column bioreactor was used as bioscrubber to carry out a feasibility study for the cometabolic degradation of trichloroethylene (TCE). Phenol was used as cosubstrate and inducer. The bioreactor was operated like a conventional chemostat with regard to the cosubstrate and low dilution rates were used to minimize the liquid outflow. TCE degradation measurements were carried out using superficial gas velocities between 0.47 and 4.07 cm s{sup {minus}1} and TCE gas phase loads between 0.07 and 0.40 mg L{sup {minus}1}. Depending on the superficial gas velocity used, degrees of conversion between 30% and 80% were obtained. A simplified reactor model using plug flow for the gas phase, mixed flow for the liquid phase, and pseudo first order reaction kinetics for the conversion of TCE was established. The model is able to give a reasonable approximation of the experimental data. TCE degradation at the used experimental conditions is mainly limited by reaction rate rather than by mass transfer rate. The model can be used to calculate the reactor value and the biomass concentration for a required conversion.

Hecht, V.; Brebbermann, D.; Bremer, P.; Deckwer, W.D. [Bereich Bioverfahrenstechnik, Braunschweig (Germany). Gesellschaft fuer Biotechnologische Forschung mbH

1995-08-20T23:59:59.000Z

105

Particle production by the expanding thin-walled bubble  

E-Print Network (OSTI)

Neglecting the effect of particle production at the moment of bubble nucleation, the spectrum of created particles during the bubble expansion is evaluated in the thin-wall approximation. It is shown that the expanding thin-walled bubble makes the dominant contribution to the particle production.

Michael Maziashvili

2003-11-27T23:59:59.000Z

106

Jet Quenching at LHC  

E-Print Network (OSTI)

We review up-to-date results on high-pt particles and jets in heavy ion collisions by three major LHC experiments, ALICE, ATLAS, and CMS. Results of analyses of 2010 and 2011 Pb+Pb data at $\\sqrt{s_{NN}} = 2.76$ TeV are discussed. We concentrate mainly on results by fully reconstructed jets and discuss similarities and important differences in measurements among experiments. We point to the importance of understanding the results in a view of difference between quark-initiated and gluon-initiated jets

Martin Spousta

2013-05-28T23:59:59.000Z

107

Angular Scaling In Jets  

SciTech Connect

We introduce a jet shape observable defined for an ensemble of jets in terms of two-particle angular correlations and a resolution parameter R. This quantity is infrared and collinear safe and can be interpreted as a scaling exponent for the angular distribution of mass inside the jet. For small R it is close to the value 2 as a consequence of the approximately scale invariant QCD dynamics. For large R it is sensitive to non-perturbative effects. We describe the use of this correlation function for tests of QCD, for studying underlying event and pile-up effects, and for tuning Monte Carlo event generators.

Jankowiak, Martin; Larkoski, Andrew J.; /SLAC

2012-02-17T23:59:59.000Z

108

Jets with Variable R  

E-Print Network (OSTI)

We introduce a new class of jet algorithms designed to return conical jets with a variable Delta R radius. A specific example, in which Delta R scales as 1/pT, proves particularly useful in capturing the kinematic features of a wide variety of hard scattering processes. We implement this Delta R scaling in a sequential recombination algorithm and test it by reconstructing resonance masses and kinematic endpoints. These test cases show 10-20% improvements in signal efficiency compared to fixed Delta R algorithms. We also comment on cuts useful in reducing continuum jet backgrounds.

David Krohn; Jesse Thaler; Lian-Tao Wang

2009-03-02T23:59:59.000Z

109

Unveiling the composition of radio plasma bubbles in galaxy clusters with the Sunyaev-Zel'dovich effect  

E-Print Network (OSTI)

The Chandra X-ray Observatory is finding a large number of cavities in the X-ray emitting intra-cluster medium which often coincide with the lobes of the central radio galaxy. We propose high-resolution Sunyaev-Zel'dovich (SZ) observations in order to infer the still unknown dynamically dominating component of the radio plasma bubbles. This work calculates the thermal and relativistic SZ emission of different compositions of these plasma bubbles while simultaneously allowing for the cluster's kinetic SZ effect. As examples, we present simulations of an Atacama Large Millimeter Array (ALMA) observation and of a Green Bank Telescope (GBT) observation of the cores of the Perseus cluster and Abell 2052. We predict a 5 sigma detection of the southern radio bubble of Perseus in a few hours with the GBT and ALMA while assuming a relativistic electron population within the bubble. In Abell 2052, a similar detection would require a few ten hours with either telescope, the longer exposures mainly being the result of the higher redshift and the lower central temperature of this cluster. Future high-sensitivity multi-frequency SZ observations will be able to infer the energy spectrum of the dynamically dominating electron population in order to measure its temperature or spectral characteristics. This knowledge can yield indirect indications for an underlying radio jet model.

Christoph Pfrommer; Torsten A. Ensslin; Craig L. Sarazin

2004-10-01T23:59:59.000Z

110

Effects of Bulk Viscosity in Non-linear Bubble Dynamics  

E-Print Network (OSTI)

The non-linear bubble dynamics equations in a compressible liquid have been modified considering the effects of compressibility of both the liquid and the gas at the bubble interface. A new bubble boundary equation has been derived, which includes a new term resulted from the liquid bulk viscosity effects. The influence of this term has been numerically investigated considering the effects of water vapor and chemical reactions on the bubble evolution. The results clearly indicate that the new term has an important damping role at the collapse, so that its consideration decreases the amplitude of the bubble rebounds after the collapse. This damping feature is more remarkable for higher deriving pressures.

Moshaii, A; Taeibi-Rahni, M; Moshaii, Ahmad; Sadighi-Bonabi, Rasool; Taeibi-Rahni, Mohammad

2003-01-01T23:59:59.000Z

111

WATER BOILER REACTOR  

DOE Patents (OSTI)

As its name implies, this reactor utilizes an aqueous solution of a fissionable element salt, and is also conventional in that it contains a heat exchanger cooling coil immersed in the fuel. Its novelty lies in the utilization of a cylindrical reactor vessel to provide a critical region having a large and constant interface with a supernatant vapor region, and the use of a hollow sleeve coolant member suspended from the cover assembly in coaxial relation with the reactor vessel. Cool water is circulated inside this hollow coolant member, and a gap between its outer wall and the reactor vessel is used to carry off radiolytic gases for recombination in an external catalyst chamber. The central passage of the coolant member defines a reflux condenser passage into which the externally recombined gases are returned and condensed. The large and constant interface between fuel solution and vapor region prevents the formation of large bubbles and minimizes the amount of fuel salt carried off by water vapor, thus making possible higher flux densities, specific powers and power densities.

King, L.D.P.

1960-11-22T23:59:59.000Z

112

Request for Naval Reactors Comment on Proposed Prometheus Space Flight Nuclear Reactor High Tier Reactor Safety Requirements and for Naval Reactors Approval to Transmit These Requirements to JPL  

SciTech Connect

The purpose of this letter is to request Naval Reactors comments on the nuclear reactor high tier requirements for the PROMETHEUS space flight reactor design, pre-launch operations, launch, ascent, operation, and disposal, and to request Naval Reactors approval to transmit these requirements to Jet Propulsion Laboratory to ensure consistency between the reactor safety requirements and the spacecraft safety requirements. The proposed PROMETHEUS nuclear reactor high tier safety requirements are consistent with the long standing safety culture of the Naval Reactors Program and its commitment to protecting the health and safety of the public and the environment. In addition, the philosophy on which these requirements are based is consistent with the Nuclear Safety Policy Working Group recommendations on space nuclear propulsion safety (Reference 1), DOE Nuclear Safety Criteria and Specifications for Space Nuclear Reactors (Reference 2), the Nuclear Space Power Safety and Facility Guidelines Study of the Applied Physics Laboratory.

D. Kokkinos

2005-04-28T23:59:59.000Z

113

Thermal Interaction Between Molten Metal Jet and Sodium Pool: Effect of Principal Factors Governing Fragmentation of the Jet  

SciTech Connect

To clarify the effects of the principal factors that govern the thermal fragmentation of a molten metallic fuel jet in the course of fuel-coolant interaction, which is important in evaluating the sequence of core disruptive accidents (CDAs) for metallic fuel fast reactors, basic experiments were carried out using molten metallic fuel simulants (copper and silver) and a sodium pool.Fragmentation of a molten metal jet with a solid crust was caused by internal pressure produced by the boiling of sodium, which is locally entrapped inside the jet due to hydrodynamic motion between the jet and the coolant. The superheating and the latent heat of fusion of the jet are the principal factors governing this type of thermal fragmentation. On the other hand, the effect of the initial sodium temperature is regarded as negligible in the case of thermal conditions expected to result in CDAs for practical metallic fuel cores. Based on the fragmentation data for several kinds of jets (Cu, Ag, SUS, U, and U-5 wt% Zr alloy), an empirical correlation is proposed that is applicable to the calculation of a mass median diameter of fragments produced by the thermal fragmentation of the jet with a solid crust under low ambient Weber number conditions.

Nishimura, Satoshi [Central Research Institute of Electric Power Industry (CRIEPI) (Japan); Kinoshita, Izumi [Central Research Institute of Electric Power Industry (CRIEPI) (Japan); Sugiyama, Ken-Ichiro [Hokkaido University (Japan); Ueda, Nobuyuki [Central Research Institute of Electric Power Industry (CRIEPI) (Japan)

2005-02-15T23:59:59.000Z

114

Dissolution Arrest and Stability of Armored Bubbles  

E-Print Network (OSTI)

Dissolving armored bubbles stabilize with nonspherical shapes by jamming the initially Brownian particles adsorbed on their interfaces. In a gas-saturated solution, these shapes are characterized by planar facets or folds for decreasing ratios of the particle to bubble radii. We perform numerical simulations that mimic dissolution, and show that the faceted shape represents a local minimum of energy during volume reduction. This minimum is marked by the vanishing of the Laplace overpressure $\\Delta P$, which together with the existence of a $V$-interval where $d\\Delta P/dV>0$ guarantees stability against dissolution. The reduction of $\\Delta P$ is due to the saddle-shape deformation of most of the interface which accompanies the reduction in the mean curvature of the interface.

Manouk Abkarian; Anand Bala Subramaniam; Shin-Hyun Kim; Ryan Larsen; Seung-Man Yang; Howard A. Stone

2007-03-25T23:59:59.000Z

115

Experimental characterisation of bubbly flow using MRI  

E-Print Network (OSTI)

the hydrophilic head resides in the water. These surfactants lower the surface tension, which decreases bubble sizes and thus increases liquid hold-up. By accumulating at the interface the surfactant molecules alter the interfacial shear condition, which can range... .1 Basic principles of NMR . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 2.1.1 Zeeman splitting . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 2.1.2 Bloch vector model . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2.1.3 Signal...

Tayler, Alexander B.

2011-11-08T23:59:59.000Z

116

Nuclear Reactors  

NLE Websites -- All DOE Office Websites (Extended Search)

Reactors Nuclear reactors created not only large amounts of plutonium needed for the weapons programs, but a variety of other interesting and useful radioisotopes. They produced...

117

Dysbaric gas bubble disease in dogs. IV. Acclimatization to diving  

Science Conference Proceedings (OSTI)

Acclimatization to diving was documented to occur in dogs. An increase in the number of repetitive dives which could be tolerated, as well as a decrease in the total number of pulmonary artery venous gas emboli resulting from individual dives were observed. The results from the experimental subject ''Jason'' indicate that acclimatization involves a reduction in the number of bubbles, and not an increase in the ability of the body to tolerate bubbles. Acclimatization is principally a physical rather than a physiological event. Bubbles forming in vivo must grow from nuclei of some sort. If these nuclei are stable, discrete structure that are destroyed when they grow into gross bubbles, then repetitive diving might markedly reduce by attrition the number of such bubble micronuclei. This would result in fewer bubbles being formed during subsequent dives, thus leading to the observed acclimatization effect. 7 refs., 3 figs., 4 tabs.

Kunkle, T.D.; Morita, A.; Beckman, E.L.

1986-01-01T23:59:59.000Z

118

Jet Fuel from Microalgal Lipids  

DOE Green Energy (OSTI)

A fact sheet on production of jet fuel or multi-purpose military fuel from lipids produced by microalgae.

Not Available

2006-07-01T23:59:59.000Z

119

Organic vapor jet printing system  

DOE Patents (OSTI)

An organic vapor jet printing system includes a pump for increasing the pressure of an organic flux.

Forrest, Stephen R

2012-10-23T23:59:59.000Z

120

Bubble coalescence dynamics and supersaturation in electrolytic gas evolution  

SciTech Connect

The apparatus and procedures developed in this research permit the observation of electrolytic bubble coalescence, which heretofore has not been possible. The influence of bubble size, electrolyte viscosity, surface tension, gas type, and pH on bubble coalescence was examined. The Navier-Stokes equations with free surface boundary conditions were solved numerically for the full range of experimental variables that were examined. Based on this study, the following mechanism for bubble coalescence emerges: when two gas bubbles coalesce, the surface energy decreases as the curvature and surface area of the resultant bubble decrease, and the energy is imparted into the surrounding liquid. The initial motion is driven by the surface tension and slowed by the inertia and viscosity of the surrounding fluid. The initial velocity of the interface is approximately proportional to the square root of the surface tension and inversely proportional to the square root of the bubble radius. Fluid inertia sustains the oblate/prolate oscillations of the resultant bubble. The period of the oscillations varies with the bubble radius raised to the 3/2 power and inversely with the square root of the surface tension. Viscous resistance dampens the oscillations at a rate proportional to the viscosity and inversely proportional to the square of the bubble radius. The numerical simulations were consistent with most of the experimental results. The differences between the computed and measured saddle point decelerations and periods suggest that the surface tension in the experiments may have changed during each run. By adjusting the surface tension in the simulation, a good fit was obtained for the 150-{micro}m diameter bubbles. The simulations fit the experiments on larger bubbles with very little adjustment of surface tension. A more focused analysis should be done to elucidate the phenomena that occur in the receding liquid film immediately following rupture.

Stover, R.L. [Univ. of California, Berkeley, CA (United States). Dept. of Chemical Engineering]|[Lawrence Berkeley National Lab., CA (United States). Energy and Environment Div.

1996-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "jet bubbling reactor" 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

The hydrogen bubble chamber and the strange resonances  

SciTech Connect

The author's recollections of his experience in the use of bubble chambers and the discoveries of strange resonances are given. (LEW)

Alvarez, L.W.

1985-06-01T23:59:59.000Z

122

Hydrodynamic Interactions of Two Micro-bubbles Due to an ...  

Science Conference Proceedings (OSTI)

Presentation Title, Hydrodynamic Interactions of Two Micro-bubbles Due to an ... A Review of Pyro, Hydro and Electro-metallurgical Processes for Recovering ...

123

Ultrasound Removing Oxygen Gas Bubbles on Anode and ...  

Science Conference Proceedings (OSTI)

Cell voltage varies as the bubbles formed on the anodes surface. ... A Study on Heat Transfer Coefficient Distribution in High Pressure Hydrogen Quenching.

124

Bubble Pump Design for Single Pressure Absorption Refrigeration Cycles  

E-Print Network (OSTI)

A model has been developed for the design and optimization of a small bubble pump to be used in a single pressure absorption refrigeration cycle to lift the working fluid mixture against gravity and overcome flow friction. This analytical model is developed from two-phase flow fundamentals and incorporates the design parameters of the bubble pump. Parametric studies are carried out and a design optimization for maximum efficiency is performed for various operating conditions. Optimum efficiency is defined as the liquid pumped per unit of bubble pump heat input. The results show the optimum bubble pump tube diameter over a range of operating conditions.

Sam V. Shelton; Susan White Stewart

2002-01-01T23:59:59.000Z

125

Simulation of Rising Bubbles Dynamics Using the Lattice Boltzmann Method.  

E-Print Network (OSTI)

?? The main purpose of this thesis was to propose and test a new approach that captures the features of single and multiple bubbles dynamics… (more)

Ngachin, Merlin

2011-01-01T23:59:59.000Z

126

Application of Reactive Oily Bubble Flotation Technology to Rare ...  

Science Conference Proceedings (OSTI)

... bubbles covered by a thin layer of oil containing oil-soluble collectors) as a ... Impurities from Multi-Source Concentrates Feeding a Rare Earths Refinery.

127

Luis Alvarez, the Hydrogen Bubble Chamber, Tritium, and Dinosaurs  

Office of Scientific and Technical Information (OSTI)

Luis Alvarez, the Hydrogen Bubble Chamber, Tritium, and Dinosaurs Resources with Additional Information Patents Luis Alvarez Courtesy Lawrence Berkeley National Laboratory 'Luis...

128

The Fundamentals of Gas Bubbling into Liquid Metals  

Science Conference Proceedings (OSTI)

Presentation Title, The Fundamentals of Gas Bubbling into Liquid Metals ... Engineering and Human Resource Development: Design as a Common Language ... Tundish Process Performance Improvement: Some Indian Case Studies.

129

The hydrogen bubble chamber and the strange resonances  

DOE Green Energy (OSTI)

The author's recollections of his experience in the use of bubble chambers and the discoveries of strange resonances are given. (LEW)

Alvarez, L.W.

1985-06-01T23:59:59.000Z

130

Ammonia chemistry in a flameless jet  

Science Conference Proceedings (OSTI)

In this paper, the nitrogen chemistry in an ammonia (NH{sub 3}) doped flameless jet is investigated using a kinetic reactor network model. The reactor network model is used to explain the main differences in ammonia chemistry for methane (CH{sub 4})-containing fuels and methane-free fuels. The chemical pathways of nitrogen oxides (NO{sub x}) formation and destruction are identified using rate-of-production analysis. The results show that in the case of natural gas, ammonia reacts relatively late at fuel lean condition leading to high NO{sub x} emissions. In the pre-ignition zone, the ammonia chemistry is blocked due to the absence of free radicals which are consumed by methane-methyl radical (CH{sub 3}) conversion. In the case of methane-free gas, the ammonia reacted very rapidly and complete decomposition was reached in the fuel rich region of the jet. In this case the necessary radicals for the ammonia conversion are generated from hydrogen (H{sub 2}) oxidation. (author)

Zieba, Mariusz; Schuster, Anja; Scheffknecht, Guenter [Institute of Process Engineering and Power Plant Technology, University of Stuttgart, Pfaffenwaldring 23, D-70569 Stuttgart (Germany); Brink, Anders; Hupa, Mikko [Process Chemistry Centre, Aabo Akademi University, Biskopsgatan 8, 20500 Aabo (Finland)

2009-10-15T23:59:59.000Z

131

Fresh Equatorial Jets  

Science Conference Proceedings (OSTI)

A vertically sheared eastward jet in the equatorial Pacific in late 1991 and early 1992 carried relatively fresh water from the western Pacific overriding the saltier surface layer of the central region. Salinity anomalies of about ?1.0 psu were ...

Dean Roemmich; Michele Morris; W. R. Young; J. R. Donguy

1994-03-01T23:59:59.000Z

132

Biofuels – Jet fuel  

This is a process for producing jet fuel from biological feed stock, including animal fats and oils, vegetable oils, and crop seed oils. The aviation and fuel-producing communities would have the option of leveraging available renewable and/or ...

133

Air Entrainment Processes and Bubble Size Distributions in the Surf Zone  

Science Conference Proceedings (OSTI)

A new optical instrument was deployed in the surf zone in a trial experiment to measure bubble size distributions and visualize air entrainment and bubble formation mechanisms within breaking surf. Images of bubbles and the evolving air–water ...

Grant B. Deane; M. Dale Stokes

1999-07-01T23:59:59.000Z

134

Flow cytometer jet monitor system  

DOE Patents (OSTI)

A direct jet monitor illuminates the jet of a flow cytometer in a monitor wavelength band which is substantially separate from the substance wavelength band. When a laser is used to cause fluorescence of the substance, it may be appropriate to use an infrared source to illuminate the jet and thus optically monitor the conditions within the jet through a CCD camera or the like. This optical monitoring may be provided to some type of controller or feedback system which automatically changes either the horizontal location of the jet, the point at which droplet separation occurs, or some other condition within the jet in order to maintain optimum conditions. The direct jet monitor may be operated simultaneously with the substance property sensing and analysis system so that continuous monitoring may be achieved without interfering with the substance data gathering and may be configured so as to allow the front of the analysis or free fall area to be unobstructed during processing.

Van den Engh, Ger (Seattle, WA)

1997-01-01T23:59:59.000Z

135

Analytical and experimental study of the acoustics and the flow field characteristics of cavitating self-resonating water jets  

DOE Green Energy (OSTI)

Waterjet nozzles (STRATOJETS) have been developed which achieve passive structuring of cavitating submerged jets into discrete ring vortices, and which possess cavitation incipient numbers six times higher than obtained with conventional cavitating jet nozzles. In this study we developed analytical and numerical techniques and conducted experimental work to gain an understanding of the basic phenomena involved. The achievements are: (1) a thorough analysis of the acoustic dynamics of the feed pipe to the nozzle; (2) a theory for bubble ring growth and collapse; (3) a numerical model for jet simulation; (4) an experimental observation and analysis of candidate second-generation low-sigma STRATOJETS. From this study we can conclude that intensification of bubble ring collapse and design of highly resonant feed tubes can lead to improved drilling rates. The models here described are excellent tools to analyze the various parameters needed for STRATOJET optimizations. Further analysis is needed to introduce such important factors as viscosity, nozzle-jet interaction, and ring-target interaction, and to develop the jet simulation model to describe the important fine details of the flow field at the nozzle exit.

Chahine, G.L.; Genoux, P.F.; Johnson, V.E. Jr.; Frederick, G.S.

1984-09-01T23:59:59.000Z

136

Photo of the Week: Not Your Typical Jet Engine | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Not Your Typical Jet Engine Not Your Typical Jet Engine Photo of the Week: Not Your Typical Jet Engine November 23, 2012 - 11:57am Addthis As part of the Aircraft Nuclear Propulsion Program, the U.S. conducted extensive research showing that nuclear fission could power an aircraft. The research involved a series of Heat Transfer Reactor Experiments (HTREs), which tested if different types of jet engines could be run by nuclear power. In 1955, however, the project was cancelled, and a safe, operational prototype aircraft was never developed. In this 1988 photo, the two HTRE reactors are shown in transport to Idaho National Laboratory's EBR-1 visitor center, where they remain today. | Photo courtesy of Idaho National Laboratory. As part of the Aircraft Nuclear Propulsion Program, the U.S. conducted

137

Condensation enhancement on a pool surface caused by a submerged liquid jet  

SciTech Connect

One advanced nuclear reactor design has a residual heat removal (RHR) pipe connected to the bottom of a steam generator outlet plenum. The water in the plenum can become thermally stratified during postulated loss of coolant accidents. Cold water injected through the RHR pipe has the potential effect of increasing the steam condensation on the pool surface due to the stirring action of the jet. The amount of increase depends on a number of factors, including the jet velocity and the pool height above the jet injection point. Prediction of steam condensation rates, before and after the jet breaks the pool surface, is the topic of this paper. Data and correlations exist for pre surface breakthrough and a method has been developed for post breakthrough. The models have been incorporated into the reactor safety analysis computer software known as RELAP5. Comparisons of predictions against data are presented.

Shumway, R.W.

1997-05-01T23:59:59.000Z

138

CONFERENCES AND SYMPOSIA FUSION REACTOR DESIGN IV  

E-Print Network (OSTI)

step and present large scale tokamak design groups should be encouraged. 3. The next reactor design (8th April 1984). These devices are the so called 'Large Tokamaks', because their parameters (Table 1 AND SYMPOSIA TABLE 1-1. CURRENT DATA BASE FOR LARGE TOKAMAKS Parameter/data TFTR JET JT-6O T-15 Major radius (m

Abdou, Mohamed

139

Fluid sampling system for a nuclear reactor  

DOE Patents (OSTI)

A system of extracting fluid samples, either liquid or gas, from the interior of a nuclear reactor containment utilizes a jet pump. To extract the sample fluid, a nonradioactive motive fluid is forced through the inlet and discharge ports of a jet pump located outside the containment, creating a suction that draws the sample fluid from the containment through a sample conduit connected to the pump suction port. The mixture of motive fluid and sample fluid is discharged through a return conduit to the interior of the containment. The jet pump and means for removing a portion of the sample fluid from the sample conduit can be located in a shielded sample grab station located next to the containment. A non-nuclear grade active pump can be located outside the grab sampling station and the containment to pump the nonradioactive motive fluid through the jet pump. 1 fig.

Lau, L.K.; Alper, N.I.

1994-11-22T23:59:59.000Z

140

Destabilization of Neutron Stars by Type I Dimension Bubbles  

E-Print Network (OSTI)

An inhomogeneous compactification of a higher dimensional spacetime can result in the formation of type I dimension bubbles, i.e., nontopological solitons which tend to absorb and entrap massive particle modes. We consider possible consequences of a neutron star that harbors such a soliton. The astrophysical outcome depends upon the model parameters for the dimension bubble, with a special sensitivity to the bubble's energy scale. For relatively small energy scales, the bubble tends to rapidly consume the star without forming a black hole. For larger energy scales, the bubble grows to a critical mass, then forms a black hole within the star, which subsequently causes the remaining star to collapse. It is possible that the latter scenario is associated with core collapse explosions and gamma ray bursts.

E. I. Guendelman; J. R. Morris

2005-01-16T23:59:59.000Z

Note: This page contains sample records for the topic "jet bubbling reactor" 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

Mechanisms of stability of armored bubbles: FY 1996 Final Report  

SciTech Connect

Theoretical and experimental studies examine how a coating, or {open_quotes}armor,{close_quotes} of partially wetted solid particles can stabilize tiny bubbles against diffusion of gas into the surrounding liquid, in spite of the high capillary pressures normally associated with such bubbles. Experiments with polymethylmethacrylate (PNMA) beads and carbonated water demonstrate that armored bubbles can persist for weeks in liquid unsaturated with respect to the gas in the bubbles. This question is of concern regarding gas discharges from waste tanks at the Hanford reservation. The stresses on the solid-solid contacts between particles in such cases is large and could drive sintering of the particles into a rigid framework. Stability analysis suggests that a slightly shrunken bubble would not expel a solid particle from its armor to relieve stress and allow the bubble to shrink further. Expulsion of particles from more stressed bubbles at zero capillary pressure is energetically favored in some cases. It is not clear, however, whether this expulsion would proceed spontaneously from a small perturbation or require a large initial disturbance of the bubble. In some cases, it appears that a bubble would expel some particles and shrink, but the bubble would approach a final, stable size rather than disappear completely. This simplified analysis leaves out several factors. For instance, only one perturbation toward expelling a solid from the armor is considered; perhaps other perturbations would be more energetically favored than that tested. Other considerations (particle deformation, surface roughness, contact-angle hysteresis, and adhesion or physical bonding between adjacent particles) would make expelling solids more difficult than indicated by this theoretical study.

Rossen, W.R.; Kam, S.I.

1996-11-01T23:59:59.000Z

142

Impact of tangled magnetic fields on AGN-blown bubbles  

E-Print Network (OSTI)

There is growing consensus that feedback from AGN is the main mechanism responsible for stopping cooling flows in clusters of galaxies. AGN are known to inflate buoyant bubbles that supply mechanical power to the intracluster gas (ICM). High Reynolds number hydrodynamical simulations show that such bubbles get entirely disrupted within 100 Myr, as they rise in cluster atmospheres, which is contrary to observations. This artificial mixing has consequences for models trying to quantify the amount of heating and star formation in cool core clusters of galaxies. It has been suggested that magnetic fields can stabilize bubbles against disruption. We perform MHD simulations of fossil bubbles in the presence of tangled magnetic fields using the high order PENCIL code. We focus on the physically-motivated case where thermal pressure dominates over magnetic pressure and consider randomly oriented fields with and without maximum helicity and a case where large scale external fields drape the bubble.We find that helicity has some stabilizing effect. However, unless the coherence length of magnetic fields exceeds the bubble size, the bubbles are quickly shredded. As observations of Hydra A suggest that lengthscale of magnetic fields may be smaller then typical bubble size, this may suggest that other mechanisms, such as viscosity, may be responsible for stabilizing the bubbles. However, since Faraday rotation observations of radio lobes do not constrain large scale ICM fields well if they are aligned with the bubble surface, the draping case may be a viable alternative solution to the problem. A generic feature found in our simulations is the formation of magnetic wakes where fields are ordered and amplified. We suggest that this effect could prevent evaporation by thermal conduction of cold Halpha filaments observed in the Perseus cluster.

M. Ruszkowski; T. A. Ensslin; M. Bruggen; S. Heinz; C. Pfrommer

2007-03-30T23:59:59.000Z

143

Theoretical Study of the Thermal Decomposition of a Jet Fuel Surrogate  

E-Print Network (OSTI)

In a scramjet, the fuel can be used to cool down the engine walls. The thermal decomposition of the jet fuel changes the reacting mixture before its combustion. A numerical study of the pyrolysis of norbornane, a jet fuel surrogate, has been performed. Rate constants of some sensitive reaction channels have been calculated by means of quantum chemical calculations at the CBS-QB3 level of theory. The mechanism has been validated against experimental results obtained in a jet-stirred reactor and important and/or sensitive pathways have been derived.

Sirjean, Baptiste; Glaude, Pierre-Alexandre; Ruiz-Lopez, M F; Fournet, René

2009-01-01T23:59:59.000Z

144

Methods for Investigating Gas Bubble Formation in Uranium-Zirconium Alloys  

E-Print Network (OSTI)

Uranium-zirconium alloy nuclear fuels have many advantages as compared with ceramic fuels, especially for fast reactor systems. However, metallic fuels aren’t currently used in commercial power production due in part to issues with fuel swelling during irradiation. A major contributor to this expansion issue, the formation of fission gasses into bubbles, is examined here. Methods to evaluate evolution of fission gas bubbles within a U-Zr alloy are discussed and refined. Specifically, transmission electron microscopy (TEM) for viewing bubbles within the interior of the alloy is investigated. One constraint on the use of the TEM is the lack of literature pertaining to what thinning techniques are successful for U-10Zr alloy. Both initial and final thinning techniques were investigated. After thinning was complete, the specimens were viewed via TEM to determine their suitability. In addition, samples of U-Zr alloy were irradiated with gas atoms in an accelerator to simulate bubble initiation and formation and viewed via TEM. Only preliminary investigations were completed. Evaluated electrolyte solutions included one part phosphoric acid to two parts sulfuric acid and two parts water (A), one part phosphoric acid to one part ethanol and one part glycerol (B), one part hydrochloric acid to one part water (C), two parts methanol to 13 parts phosphoric acid (D), and one part perchloric acid to nine parts acetic acid (G). Positive responses were received from the solutions A, C, and G which generated electron transparent areas with few to no process induced artifacts. TEM trials with each electrolyte were performed on un-irradiated U-10Zr alloy. These trials indicated that the polishing methods would work but are not yet optimal. In addition, U-10Zr alloy was irradiated and viewed in the TEM where those polished with electrolyte A consistently included the presence of large circular features that could indicate bubbles or voids. The foundation was laid for further study to be done on this topic through the use of electropolishing solutions as final thinning techniques. Additional work that is recommended includes: electropolishing parameter refinement; implantation of heavier gas atoms or at elevated temperatures; annealing of the implanted alloy; and computer modeling of resulting first principles phenomena.

Mews, Kathryn Ann Wright

2013-05-01T23:59:59.000Z

145

Effective Compressibility of a Bubbly Slurry: I. Theory of the Behavior of Bubbles Trapped in Porous Media  

SciTech Connect

Bubbles trapped within the slurry at the bottom of waste tanks at the Hanford Site expand and contract in response to ambient pressure changes. These bubbles contain hydrogen and other flammable gases that can pose a safety hazard. Determining the effective compressibility of bubbles in the slurry could allow one to make improved estimates of the quantity of gas trapped in the slurry from changes in slurry volume with ambient pressure changes. Numerical calculations based on a one-dimensional biconical-pore-network model show that the effective compressibility of a population of bubbles shows hysteresis with pressure increase and decrease. This hysteresis is caused by the unsteady, impulsive movements of interfaces from pore throat to throat during a pressure decrease and from pore body to body during a pressure increase. Snap-off may occur during these jumps but does not significantly alter the effective compressibility of the population of bubbles.

Kam, Seung I. (PEMEX REFINACION); Gauglitz, Phillip A. (BATTELLE (PACIFIC NW LAB)); Rossen, William R. (UNKNOWN)

2000-12-01T23:59:59.000Z

146

Jet initiation of PBX 9502  

SciTech Connect

This report details the progress of an effort to determine the quantitative aspects of the initiation of PBX 9502 (95% TATB, 5% Kel-F 800) by copper jets. The particular jet used was that produced by the LAW warhead (66-mm diameter, 42/sup 0/ angle cone, copper-lined, conical shaped charge). Fifteen experiments, in various configurations, have been fired to define the essential parameters for quantitatively measuring the jet performance and initiation of bare PBX 9502. 7 refs., 8 figs.

McAfee, J.M.

1987-07-01T23:59:59.000Z

147

Stellar Wind Bubbles: H-Deficient . . .  

E-Print Network (OSTI)

We present simplified one-dimensional numerical models for stellar wind bubbles (SWB), investigating two aspects: the effect of H-deicient winds, such as observed in [WR]-type centrals stars of planetary nebulae (PN) and massive Wolf-Rayet stars (WR), and the X-ray spectra produced by SWBs. For the H-deficient winds, we find that the extra cooling caused by the extremely high metal abundances influences the structure and evolution of their SWBs, although they remain mostly energy-driven. For the X-ray spectra we find that a standard SWB model cannot explain the observed spectra, and some extra physical effect is needed. We show that thermal conduction with low efficiency can be this effect.

G. Mellema

2003-01-01T23:59:59.000Z

148

Photon + jets at D0  

E-Print Network (OSTI)

Photon plus jet production has been studied by the D0 experiment in Run II of the Fermilab Tevatron Collider at a centre of mass energy of sqrt{s}=1.96 TeV. Measurements of the inclusive photon, inclusive photon plus jet, photon plus heavy flavour jet cross sections and double parton interactions in photon plus three jet events are presented. They are based on integrated luminosities between 0.4 fb$^-1 and 1.0 fb^-1. The results are compared to perturbative QCD calculations in various approximations.

Lars Sonnenschein

2009-06-15T23:59:59.000Z

149

Reactor control rod timing system  

DOE Patents (OSTI)

A fluid driven jet-edge whistle timing system for control rods of a nuclear reactor for producing real-time detection of the timing of each control rod in its scram operation. An important parameter in reactor safety, particularly for liquid metal fast breeder reactors (LMFBR), is the time deviation between the time the control rod is released and the time the rod actually reaches the down position. The whistle has a nearly pure tone signal with center frequency (above 100 kHz) far above the frequency band in which the energy of the background noise is concentrated. Each control rod can be fitted with a whistle with a different frequency so that there is no ambiguity in differentiating the signal from each control rod.

Wu, Peter T. K. (Clifton Park, NY)

1982-01-01T23:59:59.000Z

150

NUCLEAR REACTOR  

DOE Patents (OSTI)

A boiling-water nuclear reactor is described wherein control is effected by varying the moderator-to-fuel ratio in the reactor core. This is accomplished by providing control tubes containing a liquid control moderator in the reactor core and providing means for varying the amount of control moderatcr within the control tubes.

Treshow, M.

1961-09-01T23:59:59.000Z

151

NEUTRONIC REACTOR  

DOE Patents (OSTI)

A reactor in which at least a portion of the moderator is in the form of movable refractory balls is described. In addition to their moderating capacity, these balls may serve as carriers for fissionable material or fertile material, or may serve in a coolant capacity to remove heat from the reactor. A pneumatic system is used to circulate the balls through the reactor.

Daniels, F.

1959-10-27T23:59:59.000Z

152

Moduli Vacuum Bubbles Produced by Evaporating Black Holes  

E-Print Network (OSTI)

We consider a model with a toroidally compactified extra dimension giving rise to a temperature-dependent 4d effective potential with one-loop contributions due to the Casimir effect, along with a 5d cosmological constant. The forms of the effective potential at low and high temperatures indicates a possibility for the formation of a domain wall bubble, formed by the modulus scalar field, surrounding an evaporating black hole. This is viewed as an example of a recently proposed black hole vacuum bubble arising from matter-sourced moduli fields in the vicinity of an evaporating black hole [D. Green, E. Silverstein, and D. Starr, Phys. Rev. D74, 024004 (2006), arXiv:hep-th/0605047]. The black hole bubble can be highly opaque to lower energy particles and photons, and thereby entrap them within. For high temperature black holes, there may also be a symmetry-breaking black hole bubble of false vacuum of the type previously conjectured by Moss [I.G. Moss, Phys. Rev. D32,1333 (1985)], tending to reflect low energy particles from its wall. A double bubble composed of these two different types of bubble may form around the black hole, altering the hole's emission spectrum that reaches outside observers. Smaller mass black holes that have already evaporated away could have left vacuum bubbles behind that contribute to the dark matter.

J. R. Morris

2007-08-14T23:59:59.000Z

153

Measurements of Gas Bubble Size Distributions in Flowing Liquid Mercury  

Science Conference Proceedings (OSTI)

ABSTRACT Pressure waves created in liquid mercury pulsed spallation targets have been shown to induce cavitation damage on the target container. One way to mitigate such damage would be to absorb the pressure pulse energy into a dispersed population of small bubbles, however, measuring such a population in mercury is difficult since it is opaque and the mercury is involved in a turbulent flow. Ultrasonic measurements have been attempted on these types of flows, but the flow noise can interfere with the measurement, and the results are unverifiable and often unrealistic. Recently, a flow loop was built and operated at Oak Ridge National Labarotory to assess the capability of various bubbler designs to deliver an adequate population of bubbles to mitigate cavitation damage. The invented diagnostic technique involves flowing the mercury with entrained gas bubbles in a steady state through a horizontal piping section with a glass-window observation port located on the top. The mercury flow is then suddenly stopped and the bubbles are allowed to settle on the glass due to buoyancy. Using a bright-field illumination and a high-speed camera, the arriving bubbles are detected and counted, and then the images can be processed to determine the bubble populations. After using this technique to collect data on each bubbler, bubble size distributions were built for the purpose of quantifying bubbler performance, allowing the selection of the best bubbler options. This paper presents the novel procedure, photographic technique, sample visual results and some example bubble size distributions. The best bubbler options were subsequently used in proton beam irradiation tests performed at the Los Alamos National Laboratory. The cavitation damage results from the irradiated test plates in contact with the mercury are available for correlation with the bubble populations. The most effective mitigating population can now be designed into prototypical geometries for implementation into an actual SNS target.

Wendel, Mark W [ORNL; Riemer, Bernie [ORNL; Abdou, Ashraf A [ORNL

2012-01-01T23:59:59.000Z

154

Variability of Southern Ocean Jets Near Topography  

Science Conference Proceedings (OSTI)

The interaction of jets with topography in the Southern Ocean is investigated using 19 years of altimetry data. In particular, the “jet jumping” mode of variability, by which two or more jets passing close to the same topographic feature show ...

Christopher C. Chapman; Rosemary Morrow

155

Growing bubbles in a slightly supersaturated liquid solution  

E-Print Network (OSTI)

We have designed and constructed an experimental system to study gas bubble growth in slightly supersatu- rated liquids. This is achieved by working with carbon dioxide dissolved in water, pressurized at a maximum of 1 MPa and applying a small pressure drop from saturation conditions. Bubbles grow from hydrophobic cavities etched on silicon wafers, which allows us to control their number and position. Hence, the experiment can be used to investigate the interaction among bubbles growing in close proximity when the main mass transfer mechanism is diffusion and there is a limited availability of the dissolved species.

Enríquez, Oscar R; Bruggert, Gert-Wim; Lohse, Detlef; Prosperetti, Andrea; van der Meer, Devaraj; Sun, Chao

2013-01-01T23:59:59.000Z

156

CONVECTION REACTOR  

DOE Patents (OSTI)

An homogeneous nuclear power reactor utilizing convection circulation of the liquid fuel is proposed. The reactor has an internal heat exchanger looated in the same pressure vessel as the critical assembly, thereby eliminating necessity for handling the hot liquid fuel outside the reactor pressure vessel during normal operation. The liquid fuel used in this reactor eliminates the necessity for extensive radiolytic gas rocombination apparatus, and the reactor is resiliently pressurized and, without any movable mechanical apparatus, automatically regulates itself to the condition of criticality during moderate variations in temperature snd pressure and shuts itself down as the pressure exceeds a predetermined safe operating value.

Hammond, R.P.; King, L.D.P.

1960-03-22T23:59:59.000Z

157

Jet Joint Undertaking  

E-Print Network (OSTI)

Recent experience with the use of tritium fuel in the Tokamak Fusion Test Reactor and the Joint European Torus, together with progress in developing the technical design of the International Thermonuclear Experimental Reactor has expanded the technical knowledge base for tritium issues in fusion. This paper reports on an IEA workshop that brought together scientists and engineers to share experience and expertise on all fusion related tritium issues. Extensive discussion periods were devoted to exploring outstanding issues and identifying potential R&D avenues to address them. This paper summarizes the presentations, discussions and recommendations.

C H Skinner; C Gentile; J Hosea; D Mueller; P Coad; Abingdon Ox Ea; G Federici; Garching Germany; R Haange

1998-01-01T23:59:59.000Z

158

Shroud for a submerged jet cutting nozzle  

DOE Patents (OSTI)

A shroud for a submerged jet cutting nozzle is described which separates the jet from surrounding fluid environment and enhances the cutting effect.

Schwab, Thomas L. (1369 Windsor Way, Livermore, CA 94550)

1978-01-01T23:59:59.000Z

159

On the breakup of air bubbles in Hele-Shaw cell  

E-Print Network (OSTI)

We study the problem of breakup of an air bubble in a Hele-Shaw cell. In particular, we propose some sufficient conditions of breakup of the bubble, and ways to find the contraction points of its parts. We also study regulated contraction of a pair of bubbles (in which the rates of air extraction from the bubbles is controlled), and study various asymptotic questions (such as the asymptotics of contraction of a bubble to a degenerate critical point, and asymptotics of contraction of a small bubble in presence of a big bubble).

Vladimir Entov; Pavel Etingof

2008-04-30T23:59:59.000Z

160

Interferometric Visualization of Jet Flames  

Science Conference Proceedings (OSTI)

This paper presents visualizations of reacting, round jets of the premixed and nonpremixed type realized by using interferometry and, complementarily, direct photography. The available interferometer, proposed by Carlomagno (1986), employs low-cost components ... Keywords: coherent structures, combustion, destabilization, interferometry, jet flames

A. Stella; G. Guj; A. Mataloni

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "jet bubbling reactor" 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

Jet quenching and heavy quarks  

E-Print Network (OSTI)

Jet quenching and more generally physics at high transverse momentum P_T scales is a cornerstone of the heavy-ion physics program at the LHC. In this work, the current understanding of jet quenching in terms of a QCD shower evolution being modified by the surrounding medium is reviewed along with the evidence for this picture from light parton high P_T observables. Conceptually, the same QCD shower description should also be relevant for heavy quarks, but with several important modifications introduced by the quark masses. Thus especially in the limit of small jet energy over quark mass E_jet/m_q, the relevant physics may be rather different from light quark jets, and several attempts to explain the observed phenomenology of heavy quarks at high P_T are discussed here.

Thorsten Renk

2013-09-12T23:59:59.000Z

162

Numerical Simulation of Fission Gas Bubble Coarsening in Nuclear ...  

Science Conference Proceedings (OSTI)

The gas from these bubbles is periodically re-dissolved back in the nuclear fuel by very high-energy fission fragments that pass either through or near the gas ...

163

Patterns of Bubble Clouds organized by Langmuir Circulation  

Science Conference Proceedings (OSTI)

A commonly observed property of near-surface bubble distributions is their collective organization into long rows aligned with the wind under the influence of Langmuir circulation. Time series observations with sonars having fixed orientation ...

David Farmer; Ming Li

1995-06-01T23:59:59.000Z

164

The Measurement of Bubble-Size Distributions by Acoustical Backscatter  

Science Conference Proceedings (OSTI)

A multifrequency acoustical-backscatter technique is described for determining the size distribution of bubbles with radii between 8 and 130 µm. The method makes use of the resonance in the microbubbles and operates at six frequencies ranging ...

Svein Vagle; David M. Farmer

1992-10-01T23:59:59.000Z

165

Effects of interfacial surfactant contamination on bubble gas transfer  

E-Print Network (OSTI)

rmed the expectations that gas and liquid side interfacialAlves, S.S. , 2002. Gas–liquid mass transfer to singlefocuses on ?ne-bubble gas–liquid interfaces. Environmental

Rosso, D; Huo, D L; Stenstrom, M K

2006-01-01T23:59:59.000Z

166

Production Functions of Film Drops by Bursting Bubbles  

Science Conference Proceedings (OSTI)

Experimental results of Blanchard and Syzdek and of Resch and Afeti on the production of film drops by bubbles bursting at the surface of seawater were parameterized earlier by Wu. More recently, comprehensive observations have been carried out ...

Jin Wu

2001-11-01T23:59:59.000Z

167

Bubble-induced damping in displacement-driven microfluidic flows  

E-Print Network (OSTI)

Bubble damping in displacement-driven microfluidic flows was theoretically and experimentally investigated for a Y-channel microfluidic network. The system was found to exhibit linear behavior for typical microfluidic flow ...

Lee, Jongho

168

Bubbles Produced by Breaking Waves in Fresh and Salt Waters  

Science Conference Proceedings (OSTI)

A greater volume of air is entrained by breaking waves to produce many more bubbles in salt, than in fresh, water. There are, however, little differences in their sizes. These results are consistent with reported observations of whitecaps over ...

Jin Wu

2000-07-01T23:59:59.000Z

169

Engineered and Natural Marine Seep, Bubble-Driven Buoyancy Flows  

Science Conference Proceedings (OSTI)

Bubble-plume upwelling flows were studied in the marine environment through dye releases into engineered plumes and a natural hydrocarbon seep plume. For engineered plumes, these experiments measured the water column–averaged upwelling flow Vup(z...

Ira Leifer; Henrik Jeuthe; Svein Helge Gjøsund; Vegar Johansen

2009-12-01T23:59:59.000Z

170

The Fermi Bubbles as Starburst Wind Termination Shocks  

E-Print Network (OSTI)

The enhanced star formation in the inner 100 pc of the Galaxy launches a superwind, reaching ~1600 km/s for M82-like parameters. The ram pressure of the wind is very low compared to more powerful starburst winds. I show that halo gas stops the wind a few kpc from the Galactic Center. I argue that the termination shock accelerates cosmic rays, and that the resulting Inverse Compton gamma-rays are visible as the Fermi Bubbles. The Bubbles are thus wind bubbles, which the starburst can inflate within 10 Myr. They remain in steady state as long as the starburst lasts. The shock may accelerate PeV electrons and ultra-high energy protons. The Bubbles may be analogs of galactic wind termination shocks in the intergalactic medium. I discuss the advantages and problems of this model.

Lacki, Brian C

2013-01-01T23:59:59.000Z

171

The transition from two phase bubble flow to slug flow  

E-Print Network (OSTI)

The process of transition from bubble to slug flow in a vertical pipe has been studied analytically and experimentally. An equation is presented which gives the agglomeration time as a function of void fraction, channel ...

Radovcich, Nick A.

1962-01-01T23:59:59.000Z

172

Steam bubble collapse, water hammer and piping network response  

E-Print Network (OSTI)

Work on steam bubble collapse, water hammer and piping network response was carried out in two closely related but distinct sections. Volume I of ,,is report details the experiments and analyses carried out in conjunction ...

Gruel, R.

173

Photon Bubbles and the Vertical Structure of Accretion Disks  

E-Print Network (OSTI)

We consider the effects of "photon bubble" shock trains on the vertical structure of radiation pressure-dominated accretion disks. These density inhomogeneities are expected to develop spontaneously in radiation-dominated accretion disks where magnetic pressure exceeds gas pressure, even in the presence of magnetorotational instability. They increase the rate at which radiation escapes from the disk, and may allow disks to exceed the Eddington limit by a substantial factor. We first generalize the theory of photon bubbles to include the effects of finite optical depths and radiation damping. Modifications to the diffusion law at low optical depth tend to fill in the low-density regions of photon bubbles, while radiation damping inhibits the formation of photon bubbles at large radii, small accretion rates, and small heights above the equatorial plane. Accretion disks dominated by photon bubble transport may reach luminosities of 10 to >100 times the Eddington limit (L_E), depending on the mass of the central object, while remaining geometrically thin. However, photon bubble-dominated disks with alpha-viscosity are subject to the same thermal and viscous instabilities that plague standard radiation pressure-dominated disks, suggesting that they may be intrinsically unsteady. Photon bubbles can lead to a "core-halo" vertical disk structure. In super-Eddington disks the halo forms the base of a wind, which carries away substantial energy and mass, but not enough to prevent the luminosity from exceeding L_E. Photon bubble-dominated disks may have smaller color corrections than standard accretion disks of the same luminosity. They remain viable contenders for some ultraluminous X-ray sources and may play a role in the rapid growth of supermassive black holes at high redshift.

Mitchell C. Begelman

2006-02-01T23:59:59.000Z

174

Program on Technology Innovation: Sonoluminescence of Nano and Submicron Bubbles  

Science Conference Proceedings (OSTI)

In sonochemistry, ultrasound is used to alter chemical reactions and processes. The applied ultrasonic field results in the development and, later, catastrophic collapse of gas-filled bubbles in liquid through a process known as acoustic cavitation. When oscillating under an ultrasonic field, gas-filled bubbles emit brief flashes of light8212sonoluminescence. The phenomenon was discovered and first described in 1934. Although sonoluminescence has been the focus of intense research over the past 15 years,...

2007-03-30T23:59:59.000Z

175

NEUTRONIC REACTOR  

DOE Patents (OSTI)

A neutronic reactor in which neutron moderation is achieved primarily in its reflector is described. The reactor structure consists of a cylindrical central "island" of moderator and a spherical moderating reflector spaced therefrom, thereby providing an annular space. An essentially unmoderated liquid fuel is continuously passed through the annular space and undergoes fission while contained therein. The reactor, because of its small size, is particularly adapted for propulsion uses, including the propulsion of aircraft. (AEC)

Fraas, A.P.; Mills, C.B.

1961-11-21T23:59:59.000Z

176

REACTOR COOLING  

DOE Patents (OSTI)

A nuclear reactor with provisions for selectively cooling the fuel elements is described. The reactor has a plurality of tubes extending throughout. Cylindrical fuel elements are disposed within the tubes and the coolant flows through the tubes and around the fuel elements. The fuel elements within the central portion of the reactor are provided with roughened surfaces of material. The fuel elements in the end portions of the tubes within the reactor are provlded with low conduction jackets and the fuel elements in the region between the central portion and the end portions are provided with smooth surfaces of high heat conduction material.

Quackenbush, C.F.

1959-09-29T23:59:59.000Z

177

Water cooled steam jet  

DOE Patents (OSTI)

A water cooled steam jet for transferring fluid and preventing vapor lock, or vaporization of the fluid being transferred, has a venturi nozzle and a cooling jacket. The venturi nozzle produces a high velocity flow which creates a vacuum to draw fluid from a source of fluid. The venturi nozzle has a converging section connected to a source of steam, a diffuser section attached to an outlet and a throat portion disposed therebetween. The cooling jacket surrounds the venturi nozzle and a suction tube through which the fluid is being drawn into the venturi nozzle. Coolant flows through the cooling jacket. The cooling jacket dissipates heat generated by the venturi nozzle to prevent vapor lock.

Wagner, Jr., Edward P. (Idaho Falls, ID)

1999-01-01T23:59:59.000Z

178

Jet fuel from LPG  

SciTech Connect

Explains how jet fuel can be manufactured from propane and/or butane with attractive rates of return. This scheme is advantageous where large reserves of LPG-bearing gas is available or LPG is in excess. The following sequence of processes in involved: dehydrogenation of propane (and/or butane) to propylene (and/or butylene); polymerization of this monomer to a substantial yield of the desired polymer by recycling undesired polymer; and hydrotreating the polymer to saturate double bonds. An attribute of this process scheme is that each of the individual processes has been practiced commercially. The process should have appeal in those parts of the world which have large reserves of LPG-bearing natural gas but little or no crude oil, or where large excesses of LPG are available. Concludes that economic analysis shows attractive rates of return in a range of reasonable propane costs and product selling prices.

Maples, R.E.; Jones, J.R.

1983-02-01T23:59:59.000Z

179

Bubble masks for time-encoded imaging of fast neutrons.  

SciTech Connect

Time-encoded imaging is an approach to directional radiation detection that is being developed at SNL with a focus on fast neutron directional detection. In this technique, a time modulation of a detected neutron signal is induced-typically, a moving mask that attenuates neutrons with a time structure that depends on the source position. An important challenge in time-encoded imaging is to develop high-resolution two-dimensional imaging capabilities; building a mechanically moving high-resolution mask presents challenges both theoretical and technical. We have investigated an alternative to mechanical masks that replaces the solid mask with a liquid such as mineral oil. Instead of fixed blocks of solid material that move in pre-defined patterns, the oil is contained in tubing structures, and carefully introduced air gaps-bubbles-propagate through the tubing, generating moving patterns of oil mask elements and air apertures. Compared to current moving-mask techniques, the bubble mask is simple, since mechanical motion is replaced by gravity-driven bubble propagation; it is flexible, since arbitrary bubble patterns can be generated by a software-controlled valve actuator; and it is potentially high performance, since the tubing and bubble size can be tuned for high-resolution imaging requirements. We have built and tested various single-tube mask elements, and will present results on bubble introduction and propagation as a function of tubing size and cross-sectional shape; real-time bubble position tracking; neutron source imaging tests; and reconstruction techniques demonstrated on simple test data as well as a simulated full detector system.

Brubaker, Erik; Brennan, James S.; Marleau, Peter; Nowack, Aaron B.; Steele, John; Sweany, Melinda; Throckmorton, Daniel J.

2013-09-01T23:59:59.000Z

180

NEUTRONIC REACTOR  

DOE Patents (OSTI)

A nuclear reactor for isotope production is described. This reactor is designed to provide a maximum thermal neutron flux in a region adjacent to the periphery of the reactor rather than in the center of the reactor. The core of the reactor is generally centrally located with respect tn a surrounding first reflector, constructed of beryllium. The beryllium reflector is surrounded by a second reflector, constructed of graphite, which, in tune, is surrounded by a conventional thermal shield. Water is circulated through the core and the reflector and functions both as a moderator and a coolant. In order to produce a greatsr maximum thermal neutron flux adjacent to the periphery of the reactor rather than in the core, the reactor is designed so tbat the ratio of neutron scattering cross section to neutron absorption cross section averaged over all of the materials in the reflector is approximately twice the ratio of neutron scattering cross section to neutron absorption cross section averaged over all of the material of the core of the reactor.

Wigner, E.P.

1958-04-22T23:59:59.000Z

Note: This page contains sample records for the topic "jet bubbling reactor" 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

BWRVIP-41, Revision 3: BWR Vessel and Internals Project, BWR Jet Pump Assembly Inspection and Flaw Evaluation Guidelines  

Science Conference Proceedings (OSTI)

The Boiling Water Reactor Vessel and Internals Project (BWRVIP), formed in June 1994, is an association of utilities focused exclusively on BWR vessel and internals issues. This BWRVIP report provides information on potential failure locations in BWR/3-6 jet pump components and recommends an inspection program designed to ensure that the integrity of all jet pump safety functions is maintained. EPRI published a previous version of this report as BWRVIP-41, Revision 2 (EPRI 1019570). This report (EPRI Rep...

2010-09-10T23:59:59.000Z

182

Phase-Field Simulation of Intergranular Bubble Growth and ...  

Science Conference Proceedings (OSTI)

CASL: The Consortium for Advanced Simulation of Light Water Reactors: A U.S. ... Strategies for Studying High Dose Irradiation Effects in Reactor Components.

183

NUCLEAR REACTOR FUEL ELEMENT ASSEMBLY  

DOE Patents (OSTI)

A method of fabricating nuclear reactor fuel element assemblies having a plurality of longitudinally extending flat fuel elements in spaced parallel relation to each other to form channels is presented. One side of a flat side plate is held contiguous to the ends of the elements and a welding means is passed along the other side of the platertransverse to the direction of the longitudinal extension of the elements. The setting and speed of travel of the welding means is set to cause penetration of the side plate with welds at bridge the gap in each channel between adjacent fuel elements with a weld-through bubble of predetermined size. The fabrication of a high strength, dependable fuel element is provided, and the reduction of distortion and high production costs are facilitated by this method. (AEC)

Stengel, F.G.

1963-12-24T23:59:59.000Z

184

Sensitivity of Perturbation Variance and Fluxes in Turbulent Jets to Changes in the Mean Jet  

Science Conference Proceedings (OSTI)

Synoptic-scale eddy variance and fluxes of heat and momentum in midlatitude jets are sensitive to small changes in mean jet velocity, dissipation, and static stability. In this work the change in the jet producing the greatest increase in ...

Brian F. Farrell; Petros J. Ioannou

2004-11-01T23:59:59.000Z

185

The effect of a micro bubble dispersed gas phase on hydrogen isotope transport in liquid metals under nuclear irradiation  

E-Print Network (OSTI)

The present work intend to be a first step towards the understanding and quantification of the hydrogen isotope complex phenomena in liquid metals for nuclear technology. Liquid metals under nuclear irradiation in,e.g., breeding blankets of a nuclear fusion reactor would generate tritium which is to be extracted and recirculated as fuel. At the same time that tritium is bred, helium is also generated and may precipitate in the form of nano bubbles. Other liquid metal systems of a nuclear reactor involve hydrogen isotope absorption processes, e.g., tritium extraction system. Hence, hydrogen isotope absorption into gas bubbles modelling and control may have a capital importance regarding design, operation and safety. Here general models for hydrogen isotopes transport in liquid metal and absorption into gas phase, that do not depend on the mass transfer limiting regime, are exposed and implemented in OpenFOAMR CFD tool for 0D to 3D simulations. Results for a 0D case show the impact of a He dispersed phase of na...

Fradera, Jorge

2013-01-01T23:59:59.000Z

186

Plasma jet ignition device  

DOE Patents (OSTI)

An ignition device of the plasma jet type is disclosed. The device has a cylindrical cavity formed in insulating material with an electrode at one end. The other end of the cylindrical cavity is closed by a metal plate with a small orifice in the center which plate serves as a second electrode. An arc jumping between the first electrode and the orifice plate causes the formation of a highly-ionized plasma in the cavity which is ejected through the orifice into the engine cylinder area to ignite the main fuel mixture. Two improvements are disclosed to enhance the operation of the device and the length of the plasma plume. One improvement is a metal hydride ring which is inserted in the cavity next to the first electrode. During operation, the high temperature in the cavity and the highly excited nature of the plasma breaks down the metal hydride, liberating hydrogen which acts as an additional fuel to help plasma formation. A second improvement consists of a cavity insert containing a plurality of spaced, metal rings. The rings act as secondary spark gap electrodes reducing the voltage needed to maintain the initial arc in the cavity.

McIlwain, Michael E. (Franklin, MA); Grant, Jonathan F. (Wayland, MA); Golenko, Zsolt (North Reading, MA); Wittstein, Alan D. (Fairfield, CT)

1985-01-15T23:59:59.000Z

187

Mechanical cutting of irradiated reactor internal components  

Science Conference Proceedings (OSTI)

Mechanical cutting methods to volume reduce and package reactor internal components are now a viable solution for stakeholders challenged with the retirement of first generation nuclear facilities. The recent completion of the removal of the Reactor Vessel Internals (RVI) from within the Sacramento Municipal Utility District's (SMUD) Rancho Seco Nuclear Power Plant demonstrates that unlike previous methods, inclusive of plasma arc and abrasive water-jet cutting, mechanical cutting minimizes exposure to workers, costly water cleanup, and excessive secondary waste generation. Reactor internal components were segmented, packaged, and removed from the reactor building for shipment or storage, allowing the reactor cavity to be drained and follow-on reactor segmentation activities to proceed in the dry state. Area exposure rates at the work positions during the segmentation process were generally 1 mR per hr. Radiological exposure documented for the underwater segmentation processes totaled 13 person rem. The reactor internals weighing 343,000 pounds were segmented into over 200 pieces for maximum shipping package efficiency and produced 5,600 lb of stainless steel chips and shavings which were packaged in void spaces of existing disposal containers, therefore creating no additional disposal volume. Because no secondary waste was driven into suspension in the reactor cavity water, the water was free released after one pass through a charcoal bed and ion exchange filter system. Mechanical cutting techniques are capable of underwater segmentation of highly radioactive components on a large scale. This method minimized radiological exposure and costly water cleanup while creating no secondary waste.

Anderson, Michael G. [MOTA Corporation: 3410 Sunset Boulevard, West Columbia, SC, 29169 (United States)

2008-01-15T23:59:59.000Z

188

NUCLEAR REACTOR  

DOE Patents (OSTI)

A heterogeneous, natural uranium fueled, solid moderated, gas cooled reactor is described, in which the fuel elements are in the form of elongated rods and are dlsposed within vertical coolant channels ln the moderator symmetrically arranged as a regular lattice in groups. This reactor employs control rods which operate in vertical channels in the moderator so that each control rod is centered in one of the fuel element groups. The reactor is enclosed in a pressure vessel which ls provided with access holes at the top to facilitate loading and unloadlng of the fuel elements, control rods and control rod driving devices.

Moore, R.V.; Bowen, J.H.; Dent, K.H.

1958-12-01T23:59:59.000Z

189

Micro Bubble Technologies Inc MBT | Open Energy Information  

Open Energy Info (EERE)

Micro Bubble Technologies Inc MBT Micro Bubble Technologies Inc MBT Jump to: navigation, search Name Micro Bubble Technologies, Inc (MBT) Place Barrington, Illinois Sector Carbon Product US-Korean maker of cleaner burning fuel and carbon nanotube batteries. Coordinates 41.740155°, -71.308294° 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":41.740155,"lon":-71.308294,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

190

Tiny Glass Bubbles With Big Potential | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Tiny Glass Bubbles With Big Potential Tiny Glass Bubbles With Big Potential Tiny Glass Bubbles With Big Potential August 19, 2011 - 12:32pm Addthis SRNL's Porous Walled Hollow Glass Microspheres (which are about half the width of a human hair in diameter) have a network of interconnected pores that enable them to be filled with, hold and release gases and other materials. | Image courtesy of SRNL SRNL's Porous Walled Hollow Glass Microspheres (which are about half the width of a human hair in diameter) have a network of interconnected pores that enable them to be filled with, hold and release gases and other materials. | Image courtesy of SRNL Liisa O'Neill Liisa O'Neill Former New Media Specialist, Office of Public Affairs What are the key facts? SRNL's porous walled glass microspheres allow the potential for

191

Bubble Acceleration in the Ablative Rayleigh-Taylor Instability  

Science Conference Proceedings (OSTI)

The highly nonlinear evolution of the single-mode Rayleigh-Taylor instability (RTI) at the ablation front of an accelerated target is investigated in the parameter range typical of inertial confinement fusion implosions. A new phase of the nonlinear bubble evolution is discovered. After the linear growth phase and a short constant-velocity phase, it is found that the bubble is accelerated to velocities well above the classical value. This acceleration is driven by the vorticity accumulation inside the bubble resulting from the mass ablation adn vorticity convection off the ablation front. While the albative growth rates are slower than their classical values in the linear regime, the ablative RTI grows faster than the classical RTI in the nonlinear regime for deuterium and tritium ablators.

Betti, R.; Sanz, J.

2006-11-20T23:59:59.000Z

192

Bubble Acceleration in the Ablative Rayleigh-Taylor Instability  

SciTech Connect

The highly nonlinear evolution of the single-mode Rayleigh-Taylor instability (RTI) at the ablation front of an accelerated target is investigated in the parameter range typical of inertial confinement fusion implosions. A new phase of the nonlinear bubble evolution is discovered. After the linear growth phase and a short constant-velocity phase, it is found that the bubble is accelerated to velocities well above the classical value. This acceleration is driven by the vorticity accumulation inside the bubble resulting from the mass ablation and vorticity convection off the ablation front. While the ablative growth rates are slower than their classical values in the linear regime, the ablative RTI grows faster than the classical RTI in the nonlinear regime for deuterium and tritium ablators.

Betti, R.; Sanz, J. [Fusion Science Center for Extreme States of Matter and Fast Ignition Physics, Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States)

2006-11-17T23:59:59.000Z

193

Jet Performance and Jet Energy Scale Determination at CMS  

Science Conference Proceedings (OSTI)

We describe the jet response of the CMS calorimeter which will be used to study pp collisions at Large Hadron Collider at CERN, Geneva, Switzerland at {radical}(s) = 14 TeV. The electromagnetic section of calorimeter consists of lead tungstate crystals which gives an excellent resolution for electrons. The hadron section is brass-scintillator sampling calorimeter read by wavelength shifting fibers in the central region (vertical bar {eta} vertical bar < 3.0) and steel/quartz-fibers in the forward (3.0 < vertical bar {eta} vertical bar < 5.0) region. Extensive test beam calibration data has been collected. A GEANT-based calorimeter simulation has been tuned to reproduce the test beam measurements. The calorimeter response to jets has been determined using this tuned simulation. We describe the calorimeter response to jets, the jet energy resolution, and the procedure we plan to use to establish the jet energy scale from a combination of test beam and pp data when we start taking data in September 2007.

Bhatti, Anwar A. [Experimental Physics Laboratory, The Rockefeller University, 1230 York Ave, New York NY 10021 (United States)

2006-10-27T23:59:59.000Z

194

Dark matter limits froma 15 kg windowless bubble chamber  

SciTech Connect

The COUPP collaboration has successfully used bubble chambers, a technology previously applied only to high-energy physics experiments, as direct dark matter detectors. It has produced the world's most stringent spin-dependent WIMP limits, and increasingly competitive spin-independent limits. These limits were achieved by capitalizing on an intrinsic rejection of the gamma background that all other direct detection experiments must address through high-density shielding and empirically-determined data cuts. The history of COUPP, including its earliest prototypes and latest results, is briefly discussed in this thesis. The feasibility of a new, windowless bubble chamber concept simpler and more inexpensive in design is discussed here as well. The dark matter limits achieved with a 15 kg windowless chamber, larger than any previous COUPP chamber (2 kg, 4 kg), are presented. Evidence of the greater radiopurity of synthetic quartz compared to natural is presented using the data from this 15 kg device, the first chamber to be made from synthetic quartz. The effective reconstruction of the three-dimensional positions of bubbles in a highly distorted optical field, with ninety-degree bottom lighting similar to cloud chamber lighting, is demonstrated. Another innovation described in this thesis is the use of the sound produced by bubbles recorded by an array of piezoelectric sensors as the primary means of bubble detection. In other COUPP chambers, cameras have been used as the primary trigger. Previous work on bubble acoustic signature differentiation using piezos is built upon in order to further demonstrate the ability to discriminate between alpha- and neutron-induced events.

Szydagis, Matthew Mark; /Chicago U.

2010-12-01T23:59:59.000Z

195

Reactor Materials  

Energy.gov (U.S. Department of Energy (DOE))

The reactor materials crosscut effort will enable the development of innovative and revolutionary materials and provide broad-based, modern materials science that will benefit all four DOE-NE...

196

NEUTRONIC REACTORS  

DOE Patents (OSTI)

A nuclear reactor is described wherein horizontal rods of thermal- neutron-fissionable material are disposed in a body of heavy water and extend through and are supported by spaced parallel walls of graphite.

Wigner, E.P.

1960-11-22T23:59:59.000Z

197

REACTOR SHIELD  

DOE Patents (OSTI)

Radiation shield construction is described for a nuclear reactor. The shield is comprised of a plurality of steel plates arranged in parallel spaced relationship within a peripheral shell. Reactor coolant inlet tubes extend at right angles through the plates and baffles are arranged between the plates at right angles thereto and extend between the tubes to create a series of zigzag channels between the plates for the circulation of coolant fluid through the shield. The shield may be divided into two main sections; an inner section adjacent the reactor container and an outer section spaced therefrom. Coolant through the first section may be circulated at a faster rate than coolant circulated through the outer section since the area closest to the reactor container is at a higher temperature and is more radioactive. The two sections may have separate cooling systems to prevent the coolant in the outer section from mixing with the more contaminated coolant in the inner section.

Wigner, E.P.; Ohlinger, L.E.; Young, G.J.; Weinberg, A.M.

1959-02-17T23:59:59.000Z

198

NUCLEAR REACTOR  

DOE Patents (OSTI)

A nuclear reactor incorporating seed and blanket assemblies is designed. Means are provided for obtaining samples of the coolant from the blanket assemblies and for varying the flow of coolant through the blanket assemblies. (AEC)

Sherman, J.; Sharbaugh, J.E.; Fauth, W.L. Jr.; Palladino, N.J.; DeHuff, P.G.

1962-10-23T23:59:59.000Z

199

Homogeneous bubble nucleation predicted by a molecular interaction model  

SciTech Connect

The homogenous bubble nucleation of various hydrocarbons was estimated by the modified classical nucleation theory. In this modification, the kinetic formalism of the classical theory is retained while the surface energy needed for the bubble formation is calculated form the interaction energy between molecules. With a nucleation rate value of J{sub n{sub c}} = 10{sup 22} nuclei/cm{sup 3}s, this modified model gives a very good prediction of the superheat limits of liquids. In another test of the model the complete evaporation time of a butane droplet at its superheat limit is compared with experiments and found to be in good agreement.

Hoyoung Kwak; Sangbum Lee (Chung-Ang Univ., Seoul (Korea))

1991-08-01T23:59:59.000Z

200

Bubbles Help Break Energy Storage Record for Lithium Air-Batteries  

NLE Websites -- All DOE Office Websites (Extended Search)

Bubbles Help Break Energy Storage Record for Lithium Air-Batteries Bubbles Help Break Energy Storage Record for Lithium Air-Batteries Foam-base graphene keeps oxygen flowing in...

Note: This page contains sample records for the topic "jet bubbling reactor" 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

An overview of potential financial bubbles in the US financial markets  

E-Print Network (OSTI)

Financial bubbles have presented a challenge for the financial markets for a long time and caused steep losses for many investors. This thesis has two main goals relating to financial bubbles. The first is to try to determine ...

Sadalla, Marco Antonio V. (Marco Antonio Vieira)

2013-01-01T23:59:59.000Z

202

A Study on the Temperature Variation of Rise Velocity for Large Clean Bubbles  

Science Conference Proceedings (OSTI)

A series of microphysical laboratory experiments studying the hydrodynamics of single bubbles were conducted to measure the variation of rise velocity, VB, with temperature, T, and radius, r. Bubbles with an equivalent spherical radius between ...

Ira Leifer; Ranjan K. Patro; Peter Bowyer

2000-10-01T23:59:59.000Z

203

Fission Gas Bubble Nucleation in Bulk and at Grain-Boundaries of ...  

Science Conference Proceedings (OSTI)

Abstract Scope, At the very early stage of bubble nucleation in the oxide fuel, the ... The xenon and uranium vacancy ratio in the xenon bubbles are investigated next. ... A Multiscale Metal/Hydride Mechanical Model for Used-Fuel Zircaloy ...

204

NUCLEAR REACTOR  

DOE Patents (OSTI)

High temperature reactors which are uniquely adapted to serve as the heat source for nuclear pcwered rockets are described. The reactor is comprised essentially of an outer tubular heat resistant casing which provides the main coolant passageway to and away from the reactor core within the casing and in which the working fluid is preferably hydrogen or helium gas which is permitted to vaporize from a liquid storage tank. The reactor core has a generally spherical shape formed entirely of an active material comprised of fissile material and a moderator material which serves as a diluent. The active material is fabricated as a gas permeable porous material and is interlaced in a random manner with very small inter-connecting bores or capillary tubes through which the coolant gas may flow. The entire reactor is divided into successive sections along the direction of the temperature gradient or coolant flow, each section utilizing materials of construction which are most advantageous from a nuclear standpoint and which at the same time can withstand the operating temperature of that particular zone. This design results in a nuclear reactor characterized simultaneously by a minimum critiral size and mass and by the ability to heat a working fluid to an extremely high temperature.

Grebe, J.J.

1959-07-14T23:59:59.000Z

205

Moving Character Observation of Bubble Rising in Vertical Gas?Liquid Two?Phase Flow  

Science Conference Proceedings (OSTI)

The study of bubble motion in water is a basic subject in gas?liquid two?phase flow research. A suit of visualized experimental device was designed and set up. Bubble rising in stagnant liquid in a vertical translucent rectangular tank was studied using the high?speed video system combined with digital image process methods. Several bubble parameters were calculated base on the processed images. Bubble track

H. Y. Wang; F. Dong

2010-01-01T23:59:59.000Z

206

The Connection between Bubble Size Spectra and Energy Dissipation Rates in the Upper Ocean  

Science Conference Proceedings (OSTI)

A formula for the maximum size of a bubble for which surface tension forces can prevent bubble breakup by inertial forces, combined with the observed sizes of air bubbles in breaking waves, implies an energy dissipation rate. One dataset from the ...

Chris Garrett; Ming Li; David Farmer

2000-09-01T23:59:59.000Z

207

Spatial point pattern analysis applied to bubble nucleation in silicate melts  

Science Conference Proceedings (OSTI)

Experimental bubble nucleation studies are used for determining the nucleation mechanism as a function of experimental conditions, the resulting bubble number density, and can also yield estimates of the melt-vapor surface tension. This provides important ... Keywords: Bubble, Experiments, Nucleation, Spatial statistics, Spatstat

Joanna Mongrain; Jessica F. Larsen

2009-09-01T23:59:59.000Z

208

Advanced thermally stable jet fuels: Technical progress report, October 1994--December 1994  

DOE Green Energy (OSTI)

There are five tasks within this project on thermally stable coal-based jet fuels. Progress on each of the tasks is described. Task 1, Investigation of the quantitative degradation chemistry of fuels, has 5 subtasks which are described: Literature review on thermal stability of jet fuels; Pyrolytic and catalytic reactions of potential endothermic fuels: cis- and trans-decalin; Use of site specific {sup 13}C-labeling to examine the thermal stressing of 1-phenylhexane: A case study for the determination of reaction kinetics in complex fuel mixtures versus model compound studies; Estimation of critical temperatures of jet fuels; and Surface effects on deposit formation in a flow reactor system. Under Task 2, Investigation of incipient deposition, the subtask reported is Uncertainty analysis on growth and deposition of particles during heating of coal-derived aviation gas turbine fuels; under Task 3, Characterization of solid gums, sediments, and carbonaceous deposits, is subtask, Studies of surface chemistry of PX-21 activated carbon during thermal degradation of jet A-1 fuel and n-dodecane; under Task 4, Coal-based fuel stabilization studies, is subtask, Exploratory screening and development potential of jet fuel thermal stabilizers over 400 C; and under Task 5, Exploratory studies on the direct conversion of coal to high quality jet fuels, are 4 subtasks: Novel approaches to low-severity coal liquefaction and coal/resid co-processing using water and dispersed catalysts; Shape-selective naphthalene hydrogenation for production of thermally stable jet fuels; Design of a batch mode and a continuous mode three-phase reactor system for the liquefaction of coal and upgrading of coal liquids; and Exploratory studies on coal liquids upgrading using mesopores molecular sieve catalysts. 136 refs., 69 figs., 24 tabs.

Schobert, H.H.; Eser, S.; Song, C.; Hatcher, P.G.; Boehman, A.; Coleman, M.M.

1995-02-01T23:59:59.000Z

209

Research reactors - an overview  

SciTech Connect

A broad overview of different types of research and type reactors is provided in this paper. Reactor designs and operating conditions are briefly described for four reactors. The reactor types described include swimming pool reactors, the High Flux Isotope Reactor, the Mark I TRIGA reactor, and the Advanced Neutron Source reactor. Emphasis in the descriptions is placed on safety-related features of the reactors. 7 refs., 7 figs., 2 tabs.

West, C.D.

1997-03-01T23:59:59.000Z

210

Calculations of slurry pump jet impingement loads  

SciTech Connect

This paper presents a methodology to calculate the impingement load in the region of a submerged turbulent jet where a potential core exits and the jet is not fully developed. The profile of the jet flow velocities is represented by a piece-wise linear function which satisfies the conservation of momentum flux of the jet flow. The adequacy of the of the predicted jet expansion is further verified by considering the continuity of the jet flow from the region of potential core to the fully developed region. The jet impingement load can be calculated either as a direct impingement force or a drag force using the jet velocity field determined by the methodology presented.

Wu, T.T.

1996-03-04T23:59:59.000Z

211

Eddy Formation in 2½-Layer, Quasigeostrophic Jets  

Science Conference Proceedings (OSTI)

The formation of nonlinear eddies in unstable 2½-layer, quasigeostrophic jets is investigated using a piecewise constant potential vorticity, “contour dynamical” model. Both infinite and semi-infinite jet dynamics are explored, considering a ...

Ilson C. A. da Silveira; Glenn R. Flierl

2002-03-01T23:59:59.000Z

212

African Easterly Jet: Structure and Maintenance  

Science Conference Proceedings (OSTI)

This article investigates the African easterly jet (AEJ), its structure, and the forcings contributing to its maintenance, critically revisiting previous work that attributed the maintenance of the jet to soil moisture gradients over tropical ...

Man-Li C. Wu; Oreste Reale; Siegfried D. Schubert; Max J. Suarez; Randy D. Koster; Philip J. Pegion

2009-09-01T23:59:59.000Z

213

Dynamics of the Southern Hemisphere Spiral Jet  

Science Conference Proceedings (OSTI)

The formation of the Southern Hemisphere spiral jet is investigated using observations over a 40-yr period. It is found that between late March and early April, the upper-tropospheric westerly jet in the Southern Hemisphere undergoes a transition ...

Lindsey N. Williams; Sukyoung Lee; Seok-Woo Son

2007-02-01T23:59:59.000Z

214

BioJet Corporation | Open Energy Information  

Open Energy Info (EERE)

93940 Sector Carbon Product Monterey-based carbon credit developer and producer of bio-jet fuel derived from jatropha. References BioJet Corporation1 LinkedIn Connections...

215

Advanced thermally stable jet fuels  

Science Conference Proceedings (OSTI)

The Pennsylvania State University program in advanced thermally stable coal-based jet fuels has five broad objectives: (1) Development of mechanisms of degradation and solids formation; (2) Quantitative measurement of growth of sub-micrometer and micrometer-sized particles suspended in fuels during thermal stressing; (3) Characterization of carbonaceous deposits by various instrumental and microscopic methods; (4) Elucidation of the role of additives in retarding the formation of carbonaceous solids; (5) Assessment of the potential of production of high yields of cycloalkanes by direct liquefaction of coal. Future high-Mach aircraft will place severe thermal demands on jet fuels, requiring the development of novel, hybrid fuel mixtures capable of withstanding temperatures in the range of 400--500 C. In the new aircraft, jet fuel will serve as both an energy source and a heat sink for cooling the airframe, engine, and system components. The ultimate development of such advanced fuels requires a thorough understanding of the thermal decomposition behavior of jet fuels under supercritical conditions. Considering that jet fuels consist of hundreds of compounds, this task must begin with a study of the thermal degradation behavior of select model compounds under supercritical conditions. The research performed by The Pennsylvania State University was focused on five major tasks that reflect the objectives stated above: Task 1: Investigation of the Quantitative Degradation of Fuels; Task 2: Investigation of Incipient Deposition; Task 3: Characterization of Solid Gums, Sediments, and Carbonaceous Deposits; Task 4: Coal-Based Fuel Stabilization Studies; and Task 5: Exploratory Studies on the Direct Conversion of Coal to High Quality Jet Fuels. The major findings of each of these tasks are presented in this executive summary. A description of the sub-tasks performed under each of these tasks and the findings of those studies are provided in the remainder of this volume (Sections 1 through 5).

Schobert, H.H.

1999-01-31T23:59:59.000Z

216

Diving decompression models and bubble metrics: Modern computer syntheses  

Science Conference Proceedings (OSTI)

A quantitative summary of computer models in diving applications is presented, underscoring dual phase dynamics and quantifying metrics in tissue and blood. Algorithms covered include the multitissue, diffusion, split phase gradient, linear-exponential, ... Keywords: Bubble metrics, Computer algorithms, Decompression models, Dive computers, Diver staging

B. R. Wienke

2009-04-01T23:59:59.000Z

217

The oil price really is a speculative bubble  

E-Print Network (OSTI)

The oil price really is a speculative bubble. Yet only recently has the U.S. Congress, for example, showed recognition that this might even be a possibility. In general there seems to be a preference for the claim that the ...

Eckaus, Richard S.

2008-01-01T23:59:59.000Z

218

Aeration Due to Breaking Waves. Part I: Bubble Populations  

Science Conference Proceedings (OSTI)

The population of bubbles produced by breaking waves in (10 m) winds of up to 12 m s?1 is analyzed using calibrated images from a vertical pencil-beam sonar system placed on the seabed near the Dutch coast. The structure in the images is ...

A. Graham; D. K. Woolf; A. J. Hall

2004-05-01T23:59:59.000Z

219

Molecular dynamics simulation of Li surface erosion and bubble formation  

E-Print Network (OSTI)

Molecular dynamics simulation of Li surface erosion and bubble formation Z. Insepov *, A. Hassanein Structure and dynamical properties of liquid Li containing He atoms were studied by the Molecular Dynamics devices. Molecular dynamics (MD) method is capable of studying important collision processes and providing

Harilal, S. S.

220

Slow closure of denaturation bubbles in DNA: twist matters  

E-Print Network (OSTI)

The closure of long equilibrated denaturation bubbles in DNA is studied using Brownian dynamics simulations. A minimal mesoscopic model is used where the double-helix is made of two interacting bead-spring freely rotating strands, with a non-zero torsional modulus in the duplex state, $\\kappa_\\phi=$200 to 300 kT. For DNAs of lengths N=40 to 100 base-pairs (bps) with a large initial bubble in their middle, long closure times of 0.1 to 100 microseconds are found. The bubble starts winding from both ends until it reaches a 10 bp metastable state. The final closure is limited by three competing mechanisms depending on $\\kappa_\\phi$ and N: arms diffusion until their alignment, bubble diffusion along the DNA until one end is reached, or local Kramers process (crossing over a torsional energy barrier). For clamped ends or long DNAs, the closure occurs via this latter temperature activated mechanism, yielding for the first time a good quantitative agreement with experiments.

Anil Kumar Dasanna; Nicolas Destainville; John Palmeri; Manoel Manghi

2013-02-07T23:59:59.000Z

Note: This page contains sample records for the topic "jet bubbling reactor" 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

NEUTRONIC REACTOR  

DOE Patents (OSTI)

This patent relates to neutronic reactors of the heterogeneous water cooled type, and in particular to a fuel element charging and discharging means therefor. In the embodiment illustrated the reactor contains horizontal, parallel coolant tubes in which the fuel elements are disposed. A loading cart containing a magnzine for holding a plurality of fuel elements operates along the face of the reactor at the inlet ends of the coolant tubes. The loading cart is equipped with a ram device for feeding fuel elements from the magazine through the inlot ends of the coolant tubes. Operating along the face adjacent the discharge ends of the tubes there is provided another cart means adapted to receive irradiated fuel elements as they are forced out of the discharge ends of the coolant tubes by the incoming new fuel elements. This cart is equipped with a tank coataining a coolant, such as water, into which the fuel elements fall, and a hydraulically operated plunger to hold the end of the fuel element being discharged. This inveation provides an apparatus whereby the fuel elements may be loaded into the reactor, irradiated therein, and unloaded from the reactor without stopping the fiow of the coolant and without danger to the operating personnel.

Ohlinger, L.A.; Wigner, E.P.; Weinberg, A.M.; Young, G.J.

1958-09-01T23:59:59.000Z

222

Inclusive jet production at Tevatron  

Science Conference Proceedings (OSTI)

The CDF and D0 Collaborations have measured the inclusive jet cross section using 1992--93 collider data at {radical}s = 1,800 GeV. The D0 measurement is higher than NLO QCD predictions, though within systematic uncertainties. The CDF measurement is in very good agreement with NLO QCD predictions for transverse energies (E{sub T}) below 200 GeV. However it is systemically higher than NLO QCD predictions for E{sub T} above 200 GeV. The CDF measurement of two-jet mass and total transverse energy spectra also show a similar excess above QCD predictions at higher E{sub T}.

Bhatti, A.A.; CDF Collaboration; D0 Collaboration

1995-07-01T23:59:59.000Z

223

Brookhaven Medical Research Reactor  

NLE Websites -- All DOE Office Websites (Extended Search)

Medical Research Reactor BMRR The last of the Lab's reactors, the Brookhaven Medical Research Reactor (BMRR), was shut down in December 2000. The BMRR was a three megawatt...

224

Jet physics at HERA, Tevatron and LHC  

E-Print Network (OSTI)

In this short report, we discuss the Jet Physics results and perspectives at HERA, Tevatron and LHC.

C. Royon

2008-11-10T23:59:59.000Z

225

Inclusive jet production at the Tevatron  

SciTech Connect

Preliminary results on inclusive jet production in proton-antiproton collisions at {radical}s = 1.96 TeV based on 1 fb{sup -1} of CDF Run II data are presented. Measurements are preformed using different jet algorithms in a wide range of jet transverse momentum and jet rapidity. The measured cross sections are compared to next-to-leading order perturbative QCD calculations

Norniella, Olga; /Barcelona, IFAE

2006-08-01T23:59:59.000Z

226

Production of biocomponent containing jet fuels  

Science Conference Proceedings (OSTI)

Recent demands for low aromatic content jet fuels have shown significant increase in the last 20 years. This was generated by the growing of aviation. Further than quality requirements were more aggravated in front of jet fuels. This was generated by ... Keywords: aromatic content, biocomponent, crystallization point, jet fuel, kerosene, vegetable oil

Z. Eller; P. Solymosi; T. Kasza; Z. Varga; J. Hancsók

2011-12-01T23:59:59.000Z

227

REACTOR CONTROL  

DOE Patents (OSTI)

A control system employed with a high pressure gas cooled reactor in which a control rod is positioned for upward and downward movement into the neutron field from a position beneath the reactor is described. The control rod is positioned by a coupled piston cylinder releasably coupled to a power drive means and the pressurized coolant is directed against the lower side of the piston. The coolant pressure is offset by a higher fiuid pressure applied to the upper surface of the piston and means are provided for releasing the higher pressure on the upper side of the piston so that the pressure of the coolant drives the piston upwardly, forcing the coupled control rod into the ncutron field of the reactor. (AEC)

Fortescue, P.; Nicoll, D.

1962-04-24T23:59:59.000Z

228

NUCLEAR REACTOR  

DOE Patents (OSTI)

A nuclear reactor of the homogeneous liquid fuel type is described wherein the fissionable isotope is suspended or dissolved in a liquid moderator such as water. The reactor core is comprised essentially of a spherical vessel for containing the reactive composition surrounded by a reflector, preferably of beryllium oxide. The reactive composition may be an ordinary water solution of a soluble salt of uranium, the quantity of fissionable isotope in solution being sufficient to provide a critical mass in the vessel. The liquid fuel is stored in a tank of non-crtttcal geometry below the reactor vessel and outside of the reflector and is passed from the tank to the vessel through a pipe connecting the two by air pressure means. Neutron absorbing control and safety rods are operated within slots in the reflector adjacent to the vessel.

Christy, R.F.

1958-07-15T23:59:59.000Z

229

POWER REACTOR  

DOE Patents (OSTI)

A fast nuclear reactor system ls described for producing power and radioactive isotopes. The reactor core is of the heterogeneous, fluid sealed type comprised of vertically arranged elongated tubular fuel elements having vertical coolant passages. The active portion is surrounded by a neutron reflector and a shield. The system includes pumps and heat exchangers for the primary and secondary coolant circuits. The core, primary coolant pump and primary heat exchanger are disposed within an irapenforate tank which is filled with the primary coolant, in this case a liquid metal such as Na or NaK, to completely submerge these elements. The tank is completely surrounded by a thick walled concrete shield. This reactor system utilizes enriched uranium or plutonium as the fissionable material, uranium or thorium as a diluent and thorium or uranium containing less than 0 7% of the U/sup 235/ isotope as a fertile material.

Zinn, W.H.

1958-07-01T23:59:59.000Z

230

Catalytic reactor  

DOE Patents (OSTI)

A catalytic reactor is provided with one or more reaction zones each formed of set(s) of reaction tubes containing a catalyst to promote chemical reaction within a feed stream. The reaction tubes are of helical configuration and are arranged in a substantially coaxial relationship to form a coil-like structure. Heat exchangers and steam generators can be formed by similar tube arrangements. In such manner, the reaction zone(s) and hence, the reactor is compact and the pressure drop through components is minimized. The resultant compact form has improved heat transfer characteristics and is far easier to thermally insulate than prior art compact reactor designs. Various chemical reactions are contemplated within such coil-like structures such that as steam methane reforming followed by water-gas shift. The coil-like structures can be housed within annular chambers of a cylindrical housing that also provide flow paths for various heat exchange fluids to heat and cool components.

Aaron, Timothy Mark (East Amherst, NY); Shah, Minish Mahendra (East Amherst, NY); Jibb, Richard John (Amherst, NY)

2009-03-10T23:59:59.000Z

231

NEUTRONIC REACTORS  

DOE Patents (OSTI)

A method is presented for loading and unloading rod type fuel elements of a neutronic reactor of the heterogeneous, solld moderator, liquid cooled type. In the embodiment illustrated, the fuel rods are disposed in vertical coolant channels in the reactor core. The fuel rods are loaded and unloaded through the upper openings of the channels which are immersed in the coolant liquid, such as water. Unloading is accomplished by means of a coffer dam assembly having an outer sleeve which is placed in sealing relation around the upper opening. A radiation shield sleeve is disposed in and reciprocable through the coffer dam sleeve. A fuel rod engaging member operates through the axial bore in the radiation shield sleeve to withdraw the fuel rod from its position in the reactor coolant channel into the shield, the shield snd rod then being removed. Loading is accomplished in the reverse procedure.

Wigner, E.P.; Young, G.J.

1958-10-14T23:59:59.000Z

232

NUCLEAR REACTOR  

DOE Patents (OSTI)

This patent covers a power-producing nuclear reactor in which fuel rods of slightly enriched U are moderated by heavy water and cooled by liquid metal. The fuel rods arranged parallel to one another in a circle are contained in a large outer closed-end conduit that extends into a tank containing the heavy water. Liquid metal is introduced into the large conduit by a small inner conduit that extends within the circle of fuel rods to a point near the lower closed end of the outer conduit. (AEC) Production Reactors

Young, G.

1963-01-01T23:59:59.000Z

233

NEUTRONIC REACTOR  

DOE Patents (OSTI)

A nuclear reactor which uses uranium in the form of elongated tubes as fuel elements and liquid as a coolant is described. Elongated tubular uranium bodies are vertically disposed in an efficient neutron slowing agent, such as graphite, for example, to form a lattice structure which is disposed between upper and lower coolant tanks. Fluid coolant tubes extend through the uranium bodies and communicate with the upper and lower tanks and serve to convey the coolant through the uranium body. The reactor is also provided with means for circulating the cooling fluid through the coolant tanks and coolant tubes, suitable neutron and gnmma ray shields, and control means.

Wigner, E.P.; Weinberg, A.W.; Young, G.J.

1958-04-15T23:59:59.000Z

234

Power Burst Facility (PBF) Reactor Reactor Decommissioning  

NLE Websites -- All DOE Office Websites (Extended Search)

Reactor Decommissioning Click here to view Click here to view Reactor Decommissioning Click on an image to enlarge A crane removes the reactor vessel from the Power Burst Facility...

235

Anomalous capillary pressure, stress, and stability of solids-coated bubbles  

Science Conference Proceedings (OSTI)

Concern about gas discharges from waste tanks at the Hanford nuclear reservation has led to the study of the mechanisms by which gas is trapped in and then episodically released from these tanks. A two-dimensional theoretical model for solids-coated, or armored, bubbles shows how the armor can support a liquid-vapor interface of reduced or reversed curvature between the particles, giving the bubble zero or even negative capillary pressure. The inward capillary force pulling the particles into the center of the bubble are balanced by large contact forces between the particles in the armor. Thus the bubble is stabilized against dissolution of gas into surrounding liquid, which otherwise would rapidly collapse the bubble. The stresses between particles in such cases are large and could drive sintering of the particles into a rigid framework. Earlier work on solids-coated bubbles assumed that solids can freely enter or leave the bubble surface as the bubble shrinks or expands. In such a case, armored bubbles would not be stable to gas dissolution into surrounding liquid. A new free-energy analysis, however, suggests that a shrunken bubble would not spontaneously expel a solid particle from its armor to relieve stress and allow the bubble to shrink further. Implications and limitations of the theory are discussed.

Kam, S.I.; Rossen, W.R. [Univ. of Texas, Austin, TX (United States). Dept. of Petroleum and Geosystems Engineering] [Univ. of Texas, Austin, TX (United States). Dept. of Petroleum and Geosystems Engineering

1999-05-15T23:59:59.000Z

236

NEUTRONIC REACTOR  

DOE Patents (OSTI)

A reactor is described comprising a plurality of horizontal trays containing a solution of a fissionable material, the trays being sleeved on a vertical tube which contains a vertically-reciprocable control rod, a gas-tight chamber enclosing the trays, and means for conducting vaporized moderator from the chamber and for replacing vaporized moderator in the trays. (AEC)

Wigner, E.P.

1962-12-25T23:59:59.000Z

237

Neutronic reactor  

DOE Patents (OSTI)

A safety rod for a nuclear reactor has an inner end portion having a gamma absorption coefficient and neutron capture cross section approximately equal to those of the adjacent shield, a central portion containing materials of high neutron capture cross section and an outer end portion having a gamma absorption coefficient at least equal to that of the adjacent shield.

Wende, Charles W. J. (West Chester, PA)

1976-08-17T23:59:59.000Z

238

NEUTRONIC REACTOR  

DOE Patents (OSTI)

BS>A reactor cooled by water, biphenyl, helium, or other fluid with provision made for replacing the fuel rods with the highest plutonium and fission product content without disassembling the entire core and for promptly cooling the rods after their replacement in order to prevent build-up of heat from fission product activity is described.

Creutz, E.C.; Ohlinger, L.A.; Weinberg, A.M.; Wigner, E.P.; Young, G.J.

1959-10-27T23:59:59.000Z

239

NEUTRONIC REACTORS  

DOE Patents (OSTI)

The design of control rods for nuclear reactors are described. In this design the control rod consists essentially of an elongated member constructed in part of a neutron absorbing material and having tube means extending therethrough for conducting a liquid to cool the rod when in use.

Anderson, H.L.

1958-10-01T23:59:59.000Z

240

NUCLEAR REACTOR  

DOE Patents (OSTI)

A nuclear reactor is described that includes spaced vertical fuel elements centrally disposed in a pressure vessel, a mass of graphite particles in the pressure vessel, means for fluidizing the graphite particles, and coolant tubes in the pressure vessel laterally spaced from the fuel elements. (AEC)

Post, R.G.

1963-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "jet bubbling reactor" 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

NUCLEAR REACTOR  

DOE Patents (OSTI)

This patent relates to a combination useful in a nuclear reactor and is comprised of a casing, a mass of graphite irapregnated with U compounds in the casing, and at least one coolant tube extending through the casing. The coolant tube is spaced from the mass, and He is irtroduced irto the space between the mass and the coolant tube. (AEC)

Starr, C.

1963-01-01T23:59:59.000Z

242

Reactor control rod timing system. [LMFBR  

DOE Patents (OSTI)

A fluid driven jet-edge whistle timing system is described for control rods of a nuclear reactor for producing real-time detection of the timing of each control rod in its scram operation. An important parameter in reactor safety, particularly for liquid metal fast breeder reactors (LMFBR), is the time deviation between the time the control rod is released and the time the rod actually reaches the down position. The whistle has a nearly pure tone signal with center frequency (above 100 kHz) far above the frequency band in which the energy of the background noise is concentrated. Each control rod can be fitted with a whistle with a different frequency so that there is no ambiguity in differentiating the signal from each control rod.

Wu, P.T.K.

1980-03-18T23:59:59.000Z

243

Hydrodynamic models for slurry bubble column reactors. Fifth technical progress report  

DOE Green Energy (OSTI)

The objective of this work is to convert our `learning gas-solid-liquid` fluidization model into a predictive design model. The IIT hydrodynamic model computes the phase velocities and the volume fractions of gas, liquid, and particulate phases. Model verification involves a comparison of these computed velocities and volume fractions to experimental values.

Gidaspow, D.

1995-10-01T23:59:59.000Z

244

REACTOR UNLOADING  

DOE Patents (OSTI)

This patent is related to gas cooled reactors wherein the fuel elements are disposed in vertical channels extending through the reactor core, the cooling gas passing through the channels from the bottom to the top of the core. The invention is a means for unloading the fuel elements from the core and comprises dump values in the form of flat cars mounted on wheels at the bottom of the core structure which support vertical stacks of fuel elements. When the flat cars are moved, either manually or automatically, for normal unloading purposes, or due to a rapid rise in the reproduction ratio within the core, the fuel elements are permtted to fall by gravity out of the core structure thereby reducing the reproduction ratio or stopping the reaction as desired.

Leverett, M.C.

1958-02-18T23:59:59.000Z

245

NUCLEAR REACTOR  

DOE Patents (OSTI)

A neuclear reactor is described of the heterogeneous type and employing replaceable tubular fuel elements and heavy water as a coolant and moderator. A pluraltty of fuel tubesa having their axes parallel, extend through a tank type pressure vessel which contatns the liquid moderator. The fuel elements are disposed within the fuel tubes in the reaetive portion of the pressure vessel during normal operation and the fuel tubes have removable plug members at each end to permit charging and discharging of the fuel elements. The fuel elements are cylindrical strands of jacketed fissionable material having helical exterior ribs. A bundle of fuel elements are held within each fuel tube with their longitudinal axes parallel, the ribs serving to space them apart along their lengths. Coolant liquid is circulated through the fuel tubes between the spaced fuel elements. Suitable control rod and monitoring means are provided for controlling the reactor.

Treshow, M.

1958-08-19T23:59:59.000Z

246

Neutronic reactor  

DOE Patents (OSTI)

A graphite-moderated, water-cooled nuclear reactor including a plurality of rectangular graphite blocks stacked in abutting relationship in layers, alternate layers having axes which are normal to one another, alternate rows of blocks in alternate layers being provided with a channel extending through the blocks, said channeled blocks being provided with concave sides and having smaller vertical dimensions than adjacent blocks in the same layer, there being nuclear fuel in the channels.

Lewis, Warren R. (Richland, WA)

1978-05-30T23:59:59.000Z

247

NUCLEAR REACTORS  

DOE Patents (OSTI)

An active portion assembly for a fast neutron reactor is described wherein physical distortions resulting in adverse changes in the volume-to-mass ratio are minimized. A radially expandable locking device is disposed within a cylindrical tube within each fuel subassembly within the active portion assembly, and clamping devices expandable toward the center of the active portion assembly are disposed around the periphery thereof. (AEC)

Koch, L.J.; Rice, R.E. Jr.; Denst, A.A.; Rogers, A.J.; Novick, M.

1961-12-01T23:59:59.000Z

248

Bubble study could improve industrial splash control | Argonne National  

NLE Websites -- All DOE Office Websites (Extended Search)

The evolution process during drop impact: inertial retraction of an air film, contraction of the top air surface into a toroidbubble, and pinch-off of a daughter droplet in the bubble. The solid-line arrows denote the propagation of capillary waves, and the dashed-line arrow indicates the contact between the crest and the substrate. To view a larger version of the image, click on it. The evolution process during drop impact: inertial retraction of an air film, contraction of the top air surface into a toroidbubble, and pinch-off of a daughter droplet in the bubble. The solid-line arrows denote the propagation of capillary waves, and the dashed-line arrow indicates the contact between the crest and the substrate. To view a larger version of the image, click on it. The evolution process during drop impact: inertial retraction of an air film, contraction of the top air surface into a toroidbubble, and pinch-off of a daughter droplet in the bubble. The solid-line arrows denote the propagation of capillary waves, and the dashed-line arrow indicates the contact between the crest and the substrate. To view a larger version of the image, click on it.

249

REACTOR CONTROL  

DOE Patents (OSTI)

This patent relates to nuclear reactors of the type which utilize elongited rod type fuel elements immersed in a liquid moderator and shows a design whereby control of the chain reaction is obtained by varying the amount of moderator or reflector material. A central tank for containing liquid moderator and fuel elements immersed therein is disposed within a surrounding outer tank providing an annular space between the two tanks. This annular space is filled with liquid moderator which functions as a reflector to reflect neutrons back into the central reactor tank to increase the reproduction ratio. Means are provided for circulating and cooling the moderator material in both tanks and additional means are provided for controlling separately the volume of moderator in each tank, which latter means may be operated automatically by a neutron density monitoring device. The patent also shows an arrangement for controlling the chain reaction by injecting and varying an amount of poisoning material in the moderator used in the reflector portion of the reactor.

Ruano, W.J.

1957-12-10T23:59:59.000Z

250

Beaming and Jets in GRBs  

E-Print Network (OSTI)

The origin of GRBs have been a mystery for almost 30 years. The afterglowobserved in the last few years enabled redshift determination for a handful ofbursts, and the cosmological origin is now firmly established. Though thedistance scale is settled, there still remains orders of magnitude uncertaintyin their rate and in the total energy that is released in the explosion due tothe possibility that the emission is not spherical but jet-like. Contrary tothe GRB itself, the afterglow can be measured up to months and even years afterthe burst, and it can provide crucial information on the geometry of theejecta. We review the theory of afterglow from jets and discuss the evidencethat at least some of the bursts are not spherical. We discuss the prospects ofpolarization measurements, and show that this is a powerful tool inconstraining the geometry of the explosion.

Sari, R

2000-01-01T23:59:59.000Z

251

Light Water Reactors Technology Development - Nuclear Reactors  

NLE Websites -- All DOE Office Websites (Extended Search)

Light Water Reactors Light Water Reactors About Director's Welcome Organization Achievements Highlights Fact Sheets, Brochures & Other Documents Multimedia Library Visit Argonne Work with Argonne Contact us Nuclear Energy Why Nuclear Energy? Why are some people afraid of Nuclear Energy? How do nuclear reactors work? Cheaper & Safer Nuclear Energy Helping to Solve the Nuclear Waste Problem Nuclear Reactors Nuclear Reactors Early Exploration Training Reactors Basic and Applied Science Research LWR Technology Development BORAX-III lighting Arco, Idaho (Press Release) Heavy Water and Graphite Reactors Fast Reactor Technology Integral Fast Reactor Argonne Reactor Tree CP-1 70th Anniversary CP-1 70th Anniversary Argonne's Nuclear Science and Technology Legacy Argonne's Nuclear Science and Technology Legacy

252

Effects of inclined jets on turbulent oxy-flame characteristics in a triple jet burner  

Science Conference Proceedings (OSTI)

The reactants are generally injected into the industrial furnaces by jets. An effective method to act on combustion in such systems is to control the way injection jets. The present study concerns the control of turbulent flames by the jets deflection in a natural gas-oxygen burner with separated jets. The burner of 25 kW power is constituted with three aligned jets, one central natural gas jet surrounded by two oxygen jets. The principal idea is to confine the fuel jet by oxygen jets to favour the mixing in order to improve the flame stability and consequently to reduce the pollutant emissions like NO{sub x}. The flame stability and its structural properties are analyzed by the OH chemiluminescence. The Particle Image Velocimetry technique has been used to characterize the dynamic field. Results show that the control by inclined jets has a considerable effect on the dynamic behaviour and flame topology. Indeed, the control by incline of oxygen jets towards fuel jet showed a double interest: a better stabilization of flame and a significant reduction of nitrogen oxides. Measurements showed that the deflection favours the mixing and accelerates the fusion of jets allowing the flame stabilization. (author)

Boushaki, T.; Mergheni, M.A.; Sautet, J.C. [CORIA UMR 6614 CNRS-Universite et INSA de ROUEN, Avenue de l'Universite, 76 801 Saint Etienne du Rouvray, Cedex (France); Labegorre, B. [Air Liquide CRCD, Les Loges en Josas, BP 126, 78350 Jouy en Josas (France)

2008-07-15T23:59:59.000Z

253

Gamma-Ray Bursts in Pulsar Wind Bubbles: Putting the Pieces Together  

E-Print Network (OSTI)

We present the main observational features expected for GRBs that occur inside pulsar wind bubbles (PWBs). This is the most natural outcome of supranova model where initially a supernova explosion takes place, leaving a supra-massive NS, which loses its rotational energy over a time t_sd and collapses to a BH, triggering a GRB explosion. We find that the time delay t_sd between the supernova and GRB events is the most important parameter that determines the behavior of the system. We consider the afterglow, prompt GRB and direct emission from the PWB. The observational signatures for different t_sd are described and joined together into one coherent framework. Constraints on the model are derived for a spherical PWB, from the lack of detection of the PWB emission and afterglow observations. For very low values of t_sdreduces to the collapsar model; 0.4iron lines seen in some X-ray afterglows. However, we find that for a spherical PWB, this implies no detectable radio afterglow, a small jet break time and non-relativistic transition time, in disagreement with observations for some of these GRBs. These discrepancies with the observations may be reconciled by resorting to a non-spherical geometry. We find that light element lines, recently detected in a few X-ray afterglows, are expected to dominate over iron lines for small t_sd, while for large t_sd the situation is reversed. Finally, we predict that external Compton scattering of the PWB photons by the afterglow relativistic electrons, should lead to high energy emission during the early afterglow that may explain the GeV photons detected by EGRET in some GRBs, and should be detectable by future missions (GLAST).

Jonathan Granot; Dafne Guetta

2002-11-07T23:59:59.000Z

254

Advanced thermally stable jet fuels: Technical progress report, July 1994--September 1994  

DOE Green Energy (OSTI)

There are five tasks within this project on thermally stable coal-based jet fuels. Progress on each of the tasks is described. Task 1, Investigation of the quantitative degradation chemistry of fuels, has 3 subtasks which are described: Pyrolysis of n-alkylbenzenes; Thermal decomposition of n-tetradecane in near-critical region; and Re-examining the effects of reactant and inert gas pressure on tetradecane pyrolysis--Effect of cold volume in batch reactor. Under Task 2, Investigation of incipient deposition, the subtask reported is Uncertainty analysis on growth and deposition of particles during heating of coal-derived aviation gas turbine fuels; under Task 3, Investigation of the quantitative degradation chemistry of fuels, is subtask, Effects of high surface area activated carbon and decalin on thermal degradation of jet A-1 fuel and n-dodecane; under Task 4, Coal-based fuel stabilization studies, is subtask, Screening potential jet fuel stabilizers using the model compound dodecane; and under Task 5, Exploratory studies on the direct conversion of coal to high quality jet fuels, is subtask, Shape-selective naphthalene hydrogenation for production of thermally stable jet fuels. 25 refs., 64 figs., 22 tabs.

Schobert, H.H.; Eser, S.; Song, C.; Hatcher, P.G.; Boehman, A.; Coleman, M.M.

1994-07-01T23:59:59.000Z

255

The ATLAS b-Jet Trigger  

E-Print Network (OSTI)

The online event selection is crucial to reject most of the events containing uninteresting background collisions while preserving as much as possible the interesting physical signals. The b-jet selection is part of the trigger strategy of the ATLAS experiment and a set of dedicated triggers was contributing to the event selection for the 2011 running. The b-jets acceptance is increased and the background reduced by lowering jet transverse energy thresholds at the first trigger level and applying b-tagging techniques at the subsequent levels. Different physics channels, especially topologies containing more than one b-jet where higher rejection factors are achieved, benefit from using the b-jet trigger. An overview of the b-jet trigger menu and performance on data is presented.

Per Hansson

2011-11-17T23:59:59.000Z

256

Turbulent fluid jet excavation in cohesive soil : with particular application to jet grouting  

E-Print Network (OSTI)

This thesis reviews the jet grouting methodology, and the current state of practice and research. Current methods of prediction of jet grout diameters are highly empirical and site specific, and do not take into account ...

Ho, Chu Eu

2005-01-01T23:59:59.000Z

257

Nucleation and evolution of false vacuum bubbles in scalar-tensor gravity  

E-Print Network (OSTI)

In this presentation, we discuss the nucleation and subsequent evolution of false vacuum bubbles in the scalar-tensor gravity. First, we transform the scalar-tensor type theory of gravity to the standard Brans-Dicke type. Second, we transform the Brans-Dicke type theory from the Jordan frame to the Einstein frame. For a certain potential, a true vacuum bubble in the Einstein frame can be transformed to a false vacuum bubble in the Jordan frame by a conformal transformation. Thus, in the Jordan frame, the nucleation of a false vacuum bubble can be possible and its subsequent evolution can be described with the help of thin-wall approximation. False vacuum bubbles have physical importance: a set of false vacuum bubbles might generate a negative energy bath and it has further theoretical implications.

Bum-Hoon Lee; Dong-han Yeom

2011-11-01T23:59:59.000Z

258

Nuclear reactor  

DOE Patents (OSTI)

A nuclear reactor in which the core components, including fuel-rod assemblies, control-rod assemblies, fertile rod-assemblies, and removable shielding assemblies, are supported by a plurality of separate inlet modular units. These units are referred to as inlet module units to distinguish them from the modules of the upper internals of the reactor. The modular units are supported, each removable independently of the others, in liners in the supporting structure for the lower internals of the reactor. The core assemblies are removably supported in integral receptacles or sockets of the modular units. The liners, units, sockets and assmblies have inlet openings for entry of the fluid. The modular units are each removably mounted in the liners with fluid seals interposed between the opening in the liner and inlet module into which the fluid enters and the upper and lower portion of the liner. Each assembly is similarly mounted in a corresponding receptacle with fluid seals interposed between the openings where the fluid enters and the lower portion of the receptacle or fitting closely in these regions. As fluid flows along each core assembly a pressure drop is produced along the fluid so that the fluid which emerges from each core assembly is at a lower pressure than the fluid which enters the core assembly. However because of the seals interposed in the mountings of the units and assemblies the pressures above and below the units and assemblies are balanced and the units are held in the liners and the assemblies are held in the receptacles by their weights as they have a higher specific gravity than the fluid. The low-pressure spaces between each module and its liner and between each core assembly and its module is vented to the low-pressure regions of the vessel to assure that fluid which leaks through the seals does not accumulate and destroy the hydraulic balance.

Pennell, William E. (Greensburg, PA); Rowan, William J. (Monroeville, PA)

1977-01-01T23:59:59.000Z

259

Research on the Flow Pattern of Bubble Plume in an Aeration Tank  

Science Conference Proceedings (OSTI)

The flow pattern of gas?liquid two?phase flow in an aeration tank is of critical effect upon mass transfer by the convection. Bubble plume provides unsteadily fluctuating two?phase flow during the aeration. This paper the study on the unsteady structure of bubble plume is dealt with from experiment. The time?serial bubble plume images of different cases in tank have been analyzed. The RCC?PIV has been employed to calculate the velocities in those cases

W. H. Liu; T. Wan; W. Cheng; Yuichi Murai

2010-01-01T23:59:59.000Z

260

ELECTRONUCLEAR REACTOR  

DOE Patents (OSTI)

An electronuclear reactor is described in which a very high-energy particle accelerator is employed with appropriate target structure to produce an artificially produced material in commercial quantities by nuclear transformations. The principal novelty resides in the combination of an accelerator with a target for converting the accelerator beam to copious quantities of low-energy neutrons for absorption in a lattice of fertile material and moderator. The fertile material of the lattice is converted by neutron absorption reactions to an artificially produced material, e.g., plutonium, where depleted uranium is utilized as the fertile material.

Lawrence, E.O.; McMillan, E.M.; Alvarez, L.W.

1960-04-19T23:59:59.000Z

Note: This page contains sample records for the topic "jet bubbling reactor" 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

Photocatalytic reactor  

DOE Patents (OSTI)

A photocatalytic reactor for processing selected reactants from a fluid medium comprising at least one permeable photocatalytic membrane having a photocatalytic material. The material forms an area of chemically active sites when illuminated by light at selected wavelengths. When the fluid medium is passed through the illuminated membrane, the reactants are processed at these sites separating the processed fluid from the unprocessed fluid. A light source is provided and a light transmitting means, including an optical fiber, for transmitting light from the light source to the membrane.

Bischoff, Brian L. (Knoxville, TN); Fain, Douglas E. (Oak Ridge, TN); Stockdale, John A. D. (Knoxville, TN)

1999-01-01T23:59:59.000Z

262

Computational fluid dynamic modeling of fluidized-bed polymerization reactors  

SciTech Connect

Polyethylene is one of the most widely used plastics, and over 60 million tons are produced worldwide every year. Polyethylene is obtained by the catalytic polymerization of ethylene in gas and liquid phase reactors. The gas phase processes are more advantageous, and use fluidized-bed reactors for production of polyethylene. Since they operate so close to the melting point of the polymer, agglomeration is an operational concern in all slurry and gas polymerization processes. Electrostatics and hot spot formation are the main factors that contribute to agglomeration in gas-phase processes. Electrostatic charges in gas phase polymerization fluidized bed reactors are known to influence the bed hydrodynamics, particle elutriation, bubble size, bubble shape etc. Accumulation of electrostatic charges in the fluidized-bed can lead to operational issues. In this work a first-principles electrostatic model is developed and coupled with a multi-fluid computational fluid dynamic (CFD) model to understand the effect of electrostatics on the dynamics of a fluidized-bed. The multi-fluid CFD model for gas-particle flow is based on the kinetic theory of granular flows closures. The electrostatic model is developed based on a fixed, size-dependent charge for each type of particle (catalyst, polymer, polymer fines) phase. The combined CFD model is first verified using simple test cases, validated with experiments and applied to a pilot-scale polymerization fluidized-bed reactor. The CFD model reproduced qualitative trends in particle segregation and entrainment due to electrostatic charges observed in experiments. For the scale up of fluidized bed reactor, filtered models are developed and implemented on pilot scale reactor.

Rokkam, Ram [Ames Laboratory

2012-11-02T23:59:59.000Z

263

Increasing jet entrainment, mixing and spreading  

DOE Patents (OSTI)

A free jet of air is disturbed at a frequency that substantially matches natural turbulences in the free jet to increase the entrainment, mixing, and spreading of air by the free jet, for example in a room or other enclosure. The disturbances are created by pulsing the flow of air that creates the free jet at the desired frequency. Such pulsing of the flow of air can be accomplished by sequentially occluding and opening a duct that confines and directs the flow of air, such as by rotating a disk on an axis transverse to the flow of air in the duct. 11 figs.

Farrington, R.B.

1994-08-16T23:59:59.000Z

264

Increasing jet entrainment, mixing and spreading  

DOE Patents (OSTI)

A free jet of air is disturbed at a frequency that substantially matches natural turbulences in the free jet to increase the entrainment, mixing, and spreading of air by the free jet, for example in a room or other enclosure. The disturbances are created by pulsing the flow of air that creates the free jet at the desired frequency. Such pulsing of the flow of air can be accomplished by sequentially occluding and opening a duct that confines and directs the flow of air, such as by rotating a disk on an axis transverse to the flow of air in the duct.

Farrington, Robert B. (Wheatridge, CO)

1994-01-01T23:59:59.000Z

265

Safe Fluids for Jet Engine Texts  

Science Conference Proceedings (OSTI)

... industry and DoD use NIST calibration services for hydrocarbon liquid flow to ensure agreement and quality of measurements of jet fuel flow and ...

2012-08-29T23:59:59.000Z

266

Moving window unit root test| Locating real estate price bubbles in Seoul apartment market.  

E-Print Network (OSTI)

?? Bubbles are characterized by rapid expansion followed by a contraction. Evans (1991) shows that stationarity tests suggested by Hamilton and Whiteman (1985) and Diba… (more)

Shi, Shuping

2011-01-01T23:59:59.000Z

267

Fermionic and Bosonic Stabilizing Effects for Type I and Type II Dimension Bubbles  

E-Print Network (OSTI)

We consider two types of "dimension bubbles", which are viewed as 4d nontopological solitons that emerge from a 5d theory with a compact extra dimension. The size of the extra dimension varies rapidly within the domain wall of the soliton. We consider the cases of type I (II) bubbles where the size of the extra dimension inside the bubble is much larger (smaller) than outside. Type I bubbles with thin domain walls can be stabilized by the entrapment of various particle modes whose masses become much smaller inside than outside the bubble. This is demonstrated here for the cases of scalar bosons, fermions, and massive vector bosons, including both Kaluza-Klein zero modes and Kaluza-Klein excitation modes. Type II bubbles expel massive particle modes but both types can be stabilized by photons. Plasma filled bubbles containing a variety of massless or nearly massless radiation modes may exist as long-lived metastable states. Furthermore, in contrast to the case with a "gravitational bag", the metric for a fluid-filled dimension bubble does not exhibit a naked singularity at the bubble's center.

J. R. Morris

2004-05-21T23:59:59.000Z

268

Mechanisms of Jet Formation on the Giant Planets  

Science Conference Proceedings (OSTI)

The giant planet atmospheres exhibit alternating prograde (eastward) and retrograde (westward) jets of different speeds and widths, with an equatorial jet that is prograde on Jupiter and Saturn and retrograde on Uranus and Neptune. The jets are ...

Junjun Liu; Tapio Schneider

2010-11-01T23:59:59.000Z

269

SpartyJet 4.0 User's Manual  

E-Print Network (OSTI)

SpartyJet is a set of software tools for jet finding and analysis, built around the FastJet library of jet algorithms. SpartyJet provides four key extensions to FastJet: a simple Python interface to most FastJet features, a powerful framework for building up modular analyses, extensive input file handling capabilities, and a graphical browser for viewing analysis output and creating new on-the-fly analyses. Many of these capabilities rely on a ROOT-based backend. Beyond finding jets, many jet tools in SpartyJet perform measurement of jet or event variables, available to subsequent tools and stored in the final output. SpartyJet can be downloaded from HepForge at http://projects.hepforge.org/spartyjet.

Pierre-Antoine Delsart; Kurtis L. Geerlings; Joey Huston; Brian T. Martin; Christopher K. Vermilion

2012-01-17T23:59:59.000Z

270

Nuclear reactor containment spray testing system. [PWR  

SciTech Connect

Disclosed is a method for periodic testing of a spray system in a nuclear reactor containment. The method includes injecting a gas into the spray system such that a temperature differential exists between the gas and the containment atmosphere. Scanning the gas jet discharged from the spray nozzles with infrared apparatus then provides a real-time thermal image on a monitor, such as a cathode ray tube, and detects any partially or completely blocked nozzles in the spray system. The scanning may be performed from the containment operating deck. 1 claim, 4 figures.

Rubin, K.

1978-01-10T23:59:59.000Z

271

Angular Energy Distribution of Collapsar-Jets  

E-Print Network (OSTI)

Collapsars are fast-spinning, massive stars, whose core collapse liberates an energy, that can be channeled in the form of ultrarelativistic jets. These jets transport the energy from the collapsed core to large distances, where it is dissipated in the form of long-duration gamma-ray bursts. In this paper we study the dynamics of ultrarelativistic jets produced in collapsars. Also we extrapolate our results to infer the angular energy distribution of the produced outflows in the afterglow phase. Our main focus is to look for global energetical properties which can be imprinted by the different structure of different progenitor stars. Thus, we employ a number of pre-supernova, stellar models (with distinct masses and metallicities), and inject in all of them jets with fixed initial conditions. We assume that at the injection nozzle, the jet is mildly relativistic (Lorentz factor $\\sim 5$), has a finite half-opening angle ($5^\\circ$), and carries a power of $10^{51} $erg s$^{-1}$. These jets arrive intact to the stellar surface and break out of it. A large Lorentz factor region $\\Gamma\\simmore 100$ develops well before the jet reaches the surface of the star, in the unshocked part of the beam, located between the injection nozzle and the first recollimation shock. These high values of $\\Gamma$ are possible because the finite opening angle of the jet allows for free expansion towards the radial direction. We find a strong correlation between the angular energy distribution of the jet, after its eruption from the progenitor surface, and the mass of the progenitors. The angular energy distribution of the jets from light progenitor models is steeper than that of the jets injected in more massive progenitor stars. This trend is also imprinted in the angular distribution of isotropic equivalent energy.

Akira Mizuta; Miguel A. Aloy

2008-12-28T23:59:59.000Z

272

Heat transfer investigations in a slurry bubble column  

SciTech Connect

Slurry bubble columns, for use in Fisher-Tropsch synthesis, have been investigated. Two bubble columns (0.108 and 0.305 m internal diameter) were set up and experiments were conducted to determine gas holdup and heat transfer coefficients. These columns were equipped with either single heat transfer probes of different diameters, or bundles of five-, seven- or thirty-seven tubes. The experiments were conducted for two- and three-phase systems; employing for gas phase: air and nitrogen, liquid phase: water and Therminol-66, and solid phase: red iron oxide (1.02, 1.70 and 2.38 {mu}m), glass beads (50.0, 90.0, 119.0 and 143.3 {mu}m), silica sand (65 {mu}), and magnetite (28.0, 35.7, 46.0, 58.0, 69.0, 90.5, 115.5, and 137.5 {mu}m). The column temperature was varied between 298--523 K, gas velocity between 0--40 cm/s, and solids concentration between 0--50 weight percent. The holdup and heat transfer data as a function of operating and system parameters were employed to assess the available correlations and semitheoretical models, and to develop new correlations. Information concerning the design and scale-up of larger units is presented. Specific research work that need to be undertaken to understand the phenomena of heat transfer and gas holdup is outlined so that efficient gas conversion and catalyst usage may be accomplished in slurry bubble columns. 130 refs., 177 figs., 54 tabs.

Saxena, S.C.; Rao, N.S.; Vadivel, R.; Shrivastav, S.; Saxena, A.C.; Patel, B.B.; Thimmapuram, P.R.; Kagzi, M.Y.; Khan, I.A.; Verma, A.K.

1991-02-01T23:59:59.000Z

273

CONTROL MEANS FOR REACTOR  

DOE Patents (OSTI)

An apparatus for controlling a nuclear reactor includes a tank just below the reactor, tubes extending from the tank into the reactor, and a thermally expansible liquid neutron absorbent material in the tank. The liquid in the tank is exposed to a beam of neutrons from the reactor which heats the liquid causing it to expand into the reactor when the neutron flux in the reactor rises above a predetermincd danger point. Boron triamine may be used for this purpose.

Manley, J.H.

1961-06-27T23:59:59.000Z

274

Helix untwisting and bubble formation in circular DNA  

E-Print Network (OSTI)

The base pair fluctuations and helix untwisting are examined for a circular molecule. A realistic mesoscopic model including twisting degrees of freedom and bending of the molecular axis is proposed. The computational method, based on path integral techniques, simulates a distribution of topoisomers with various twist numbers and finds the energetically most favorable molecular conformation as a function of temperature. The method can predict helical repeat, openings loci and bubble sizes for specific sequences in a broad temperature range. Some results are presented for a short DNA circle recently identified in mammalian cells.

Zoli, Marco

2013-01-01T23:59:59.000Z

275

Fast Magnetic Reconnection in Laser-Produced Plasma Bubbles  

SciTech Connect

Recent experiments have observed magnetic reconnection in high-energy-density, laser-produced plasma bubbles, with reconnection rates observed to be much higher than can be explained by classical theory. Based on fully kinetic particle simulations we find that fast reconnection in these strongly driven systems can be explained by magnetic flux pileup at the shoulder of the current sheet and subsequent fast reconnection via two-fluid, collisionless mechanisms. In the strong drive regime with two-fluid effects, we find that the ultimate reconnection time is insensitive to the nominal system Alfven time.

Fox, W.; Bhattacharjee, A.; Germaschewski, K. [Center for Integrated Computation and Analysis of Reconnection and Turbulence, and Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas, University of New Hampshire, Durham, New Hampshire 03824 (United States)

2011-05-27T23:59:59.000Z

276

HEFA and F-T jet fuel cost analyses  

E-Print Network (OSTI)

Aviation and the Environment 2. HEFA jet fuel from vegetable oil bottom-up cost study 3. HEFA jet fuel from microalgae bottom-up cost

Nick Carter; Michael Bredehoeft; Christoph Wollersheim; Hakan Olcay; James Hileman; Steven Barrett; Website Lae. Mit. Edu

2012-01-01T23:59:59.000Z

277

Jet Fuel Supply/Price Outlook - Fueling the Recovery  

U.S. Energy Information Administration (EIA)

Jet Fuel Supply/Price Outlook: Fueling the Recovery Energy Information Administration Presentation to 4th International Jet Fuel Conference February ...

278

Aerosol Jet® Material Deposition for High Resolution Printed ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Aerosol Jet printing, is finding wide use in a number of ... The Aerosol Jet systems deposit a wide variety of functional materials onto a wide ...

279

Nuclear Reactor Accidents  

NLE Websites -- All DOE Office Websites (Extended Search)

Reactor Accidents The accidents at the Three Mile Island (TMI) and Chernobyl nuclear reactors have triggered particularly intense concern about radiation hazards. The TMI accident,...

280

Principles of Reactor Physics  

NLE Websites -- All DOE Office Websites (Extended Search)

Nuclear Reactor Physics M A Smith Argonne National Laboratory Nuclear Engineering Division Phone: 630-252-9747, Email: masmith@anl.gov Abstract: Nuclear reactor physics deals with...

Note: This page contains sample records for the topic "jet bubbling reactor" 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

Liquid uranium alloy-helium fission reactor  

DOE Patents (OSTI)

This invention describes a nuclear fission reactor which has a core vessel and at least one tandem heat exchanger vessel coupled therewith across upper and lower passages to define a closed flow loop. Nuclear fuel such as a uranium alloy in its liquid phase fills these vessels and flow passages. Solid control elements in the reactor core vessel are adapted to be adjusted relative to one another to control fission reaction of the liquid fuel therein. Moderator elements in the other vessel and flow passages preclude fission reaction therein. An inert gas such as helium is bubbled upwardly through the heat exchanger vessel operable to move the liquid fuel upwardly therein and unidirectionally around the closed loop and downwardly through the core vessel. This helium gas is further directed to heat conversion means outside of the reactor vessels to utilize the heat from the fission reaction to generate useful output. The nuclear fuel operates in the 1200 to 1800/sup 0/C range, and even higher to 2500/sup 0/C.

Minkov, V.

1984-06-13T23:59:59.000Z

282

Liquid uranium alloy-helium fission reactor  

SciTech Connect

This invention teaches a nuclear fission reactor having a core vessel and at least one tandem heat exchanger vessel coupled therewith across upper and lower passages to define a closed flow loop. Nuclear fuel such as a uranium alloy in its liquid phase fills these vessels and flow passages. Solid control elements in the reactor core vessel are adapted to be adjusted relative to one another to control fission reaction of the liquid fuel therein. Moderator elements in the other vessel and flow passages preclude fission reaction therein. An inert gas such as helium is bubbled upwardly through the heat exchanger vessel operable to move the liquid fuel upwardly therein and unidirectionally around the closed loop and downwardly through the core vessel. This helium gas is further directed to heat conversion means outside of the reactor vessels to utilize the heat from the fission reaction to generate useful output. The nuclear fuel operates in the 1200.degree.-1800.degree. C. range, and even higher to 2500.degree. C., limited only by the thermal effectiveness of the structural materials, increasing the efficiency of power generation from the normal 30-35% with 300.degree.-500.degree. C. upper limit temperature to 50-65%. Irradiation of the circulating liquid fuel, as contrasted to only localized irradiation of a solid fuel, provides improved fuel utilization.

Minkov, Vladimir (Skokie, IL)

1986-01-01T23:59:59.000Z

283

NEUTRONIC REACTOR  

DOE Patents (OSTI)

A power plant is described comprising a turbine and employing round cylindrical fuel rods formed of BeO and UO/sub 2/ and stacks of hexagonal moderator blocks of BeO provided with passages that loosely receive the fuel rods so that coolant may flow through the passages over the fuels to remove heat. The coolant may be helium or steam and fiows through at least one more heat exchanger for producing vapor from a body of fluid separate from the coolant, which fluid is to drive the turbine for generating electricity. By this arrangement the turbine and directly associated parts are free of particles and radiations emanating from the reactor. (AEC)

Daniels, F.

1962-12-18T23:59:59.000Z

284

Electro jet drilling using hybrid NNGA approach  

Science Conference Proceedings (OSTI)

This paper presents a hybrid neural network and genetic algorithm (NNGA) approach for the multi-response optimization of the electro jet drilling (EJD) process. The approach first uses a neural network model to predict the response parameters of the ... Keywords: Electro jet drilling, Electrochemical machining, Genetic algorithm, Multi-response, Neural network, Optimization

Mohan Sen; H. S. Shan

2007-02-01T23:59:59.000Z

285

Formation of Jets by Baroclinic Turbulence  

Science Conference Proceedings (OSTI)

Turbulent fluids are frequently observed to spontaneously self-organize into large spatial-scale jets; geophysical examples of this phenomenon include the Jovian banded winds and the earth’s polar-front jet. These relatively steady large-scale ...

Brian F. Farrell; Petros J. Ioannou

2008-11-01T23:59:59.000Z

286

Inertial Resonance Induced by an Oceanic Jet  

Science Conference Proceedings (OSTI)

The dynamics of the mixed layer in the presence of an embedded geostrophic jet has been investigated using a simple 1½-layer model and a two-dimensional primitive equation model. The jet vorticity induces a spatial variability of the wind-driven ...

P. Klein; A. M. Treguier

1993-09-01T23:59:59.000Z

287

Dynamics of the West African Westerly Jet  

Science Conference Proceedings (OSTI)

The West African westerly jet (WAWJ) is a low-level westerly jet located at 8°–11°N over the eastern Atlantic and the West African coast. It is clearly distinguished from the monsoon westerly flow by its structure and dynamics, and plays an ...

Bing Pu; Kerry H. Cook

2010-12-01T23:59:59.000Z

288

Ditau jets in Higgs searches  

SciTech Connect

Understanding and identifying ditau jets--jets consisting of pairs of tau particles--can be of crucial importance and may even turn out to be a necessity if the Higgs boson decays dominantly to new light scalars which, on the other hand, decay to tau pairs. As often seen in various models beyond the standard model such as in the next-to-minimal supersymmetric standard model, Higgs portals, etc., the lightness of these new states ensures their large transverse momenta and, as a consequence, the collinearity of their decay products. We show that the nonstandard signatures of these objects, which can easily be missed by standard analysis techniques, can be superbly exploited in an analysis based on subjet observables. When combined with additional selection strategies, this analysis can even facilitate an early discovery of the Higgs boson. To be specific, a light Higgs can be found with S/{radical}(B) > or approx. 5 from L{approx_equal}12 fb{sup -1} of data. We combine all these observables into a single discriminating likelihood that can be employed toward the construction of a realistic and standalone ditau tagger.

Englert, Christoph; Roy, Tuhin S.; Spannowsky, Michael [Institute for Theoretical Physics, Heidelberg University, 69120 Heidelberg (Germany); Department of Physics, University of Washington, Seattle, Washington 98195 (United States); Institute of Theoretical Science, University of Oregon, Eugene, Oregon 97403 (United States)

2011-10-01T23:59:59.000Z

289

Hypervelocity jets from conical hollow-charges  

Science Conference Proceedings (OSTI)

In this article the formation of jets by means of the implosion of conical targets is analyzed. This implosion might be induced by high intensity lasers or X rays. It is known of experiments with explosive and numeric simulations that the formation of jets depends critically on the aperture of the cone. It is found in these simulations that for a given collapsing speed an angle of the cone exists below which jet doesn't take place. This critical angle grows with the collapsing speed. The numerical simulations seem to indicate that the production of jets is related to the separation of the shock wave that takes place in the collapsing region. We will also analyze the mass and kinetic energy of the jets taken place as a function of the initial opening of the cone.

Velarde, P. M.; Martinez-Val, J. M.; Eliezer, S.; Piera, M.; Guillen, J.; Cobo, M. D.; Ogando, F.; Crisol, A.; Gonzalez, L.; Prieto, J.; Velarde, G. [Instituto de Fusion Nuclear Universidad Politecnico de Madrid Jose Gutierrez Abascal 2, 28006 Madrid (Spain)

1997-04-15T23:59:59.000Z

290

A dichotomy in radio jet orientations  

E-Print Network (OSTI)

We examine the relative orientations of radio jets, central dust and stars in low-power (i.e., FR I and FR I/II) radio galaxies. We use the position angles of jet and dust to constrain the three-dimensional angle $\\theta_{\\rm DJ}$ between jet and dust. For galaxies with filamentary dust 'lanes' (which tend to be misaligned with the galaxy major axis) the jet is approximately perpendicular to the dust structure, while for galaxies with elliptical dust distributions (typically aligned with the galaxy major axis) there is a much wider distribution of $\\theta_{\\rm DJ}$. nThe dust ellipses are consistent with being nearly circular thin disks viewed at random viewing angles. The lanes are likely warped, unsettled dust structures. We consider two scenarios to explain the dust/jet orientation dichotomy.

Gijs Verdoes Kleijn; Tim de Zeeuw

2005-11-30T23:59:59.000Z

291

Comparison of heat transfer characteristics of axisymmetric and two dimensional reattachment jet nozzles to conventional jet impingement nozzles.  

E-Print Network (OSTI)

??The Radial Jet Reattachment (RJR) nozzle was developed over the past decade as a modification of the In-Line Jet (ILJ) nozzle in order to enhance… (more)

Narayanan, Vinod

2012-01-01T23:59:59.000Z

292

CO observation of the Galactic bubble N4  

E-Print Network (OSTI)

We presented a study on the Galactic bubble N4 using the 13.7 m millimeter telescope of Purple Mountain Observatory at the Qinghai Station. N4 is one of the science demonstration regions for the Milky Way Imaging Scroll Painting (WMISP). Simultaneous observations of $^{12}$CO (J = 1$-$0), $^{13}$CO (J = 1$-$0) and C$^{18}$O (J = 1$-$0) line emission towards N4 were carried out. We analyzed the spectral profile and the distribution of the molecular gas. Morphologically, the CO emissions correlate well with Spitzer IRAC 8.0 $\\mu$m emission. The channel map and velocity-position diagram shows that N4 is more likely an inclined expanding ring than a spherical bubble. We calculated the physical parameters of N4 including the mass, size, column density and optical depth. Some massive star candidates were discovered in the region of N4 using (J, J$-$H) color-magnitude diagram. We found an energy source candidate for the expansion of N4, a massive star with a mass of ${\\sim} 15\\,M_{\\odot}$ and an age of $\\sim$ 1 Myr....

Li, Junyu; Liu, Yao; Wang, Yuan

2013-01-01T23:59:59.000Z

293

Reactor and method of operation  

DOE Patents (OSTI)

A nuclear reactor having a flattened reactor activity curve across the reactor includes fuel extending over a lesser portion of the fuel channels in the central portion of the reactor than in the remainder of the reactor.

Wheeler, John A. (Princeton, NJ)

1976-08-10T23:59:59.000Z

294

Ellipsoidal model of the rise of a Taylor bubble in a round tube T. Funada a  

E-Print Network (OSTI)

November 2004 Abstract The rise velocity of long gas bubbles (Taylor bubbles) in round tubes is modeled in Eo; the composition of these separate power laws emerge as 0301-9322/$ - see front matter Ã? 2005 rising steadily in a li- quid is in a balance of buoyant weight and drag. It is natural to think

Joseph, Daniel D.

295

Hydrodynamic simulation of air bubble implosion using a level set approach  

Science Conference Proceedings (OSTI)

The hydrodynamics of the implosion and rebound of a small (10 µm diameter) air bubble in water was studied using a three-dimensional direct numerical simulation (DNS). To study this problem, we developed a novel stabilized finite element method ... Keywords: bubble implosion, finite element, level set, two phase-flow

Sunitha Nagrath; Kenneth Jansen; Richard T. Lahey, Jr.; Iskander Akhatov

2006-06-01T23:59:59.000Z

296

Gas Exchange and Bubble-Induced Supersaturation in a Wind-Wave Tank  

Science Conference Proceedings (OSTI)

Gas exchange and bubble-induced supersaturation were measured in a wind-wave tank using total gas saturation meters. The water in the tank was subjected to bubbling using a large number of frits at a depth of 0.6 m.

Peter Bowyer; David Woolf

2004-12-01T23:59:59.000Z

297

Vessel-Spanning Bubble Formation in K-Basin Sludge Stored in Large-Diameter Containers  

DOE Green Energy (OSTI)

The K Basin sludge to be retrieved and stored in the large diameter containers (LDCs) contains some fraction of uranium metal that generates hydrogen gas, which introduces potential upset conditions. One postulated upset condition is a rising plug of sludge supported by a hydrogen bubble that is driven into the vent filters at the top of the container. In laboratory testing with actual K Basin sludge, vessel-spanning bubbles that lifted plugs of sludge were observed in 3-inch-diameter graduated cylinders. This report presents a series of analytical assessments performed by the Pacific Northwest National Laboratory to address the potential for the generation of a vessel spanning bubble in the LDCs. The assessments included the development and evaluation of static and dynamic bubble formation models over the projected range of K Basin sludge physical properties. Additionally, the theory of circular plates was extrapolated to examine conditions under which a plug of sludge would collapse and release a spanning bubble.

Terrones, Guillermo; Gauglitz, Phillip A.

2002-03-01T23:59:59.000Z

298

Reactor safety method  

DOE Patents (OSTI)

This invention relates to safety means for preventing a gas cooled nuclear reactor from attaining criticality prior to start up in the event the reactor core is immersed in hydrogenous liquid. This is accomplished by coating the inside surface of the reactor coolant channels with a neutral absorbing material that will vaporize at the reactor's operating temperature.

Vachon, Lawrence J. (Clairton, PA)

1980-03-11T23:59:59.000Z

299

NEUTRONIC REACTOR MANIPULATING DEVICE  

DOE Patents (OSTI)

A cable connecting a control rod in a reactor with a motor outside the reactor for moving the rod, and a helical conduit in the reactor wall, through which the cable passes are described. The helical shape of the conduit prevents the escape of certain harmful radiations from the reactor. (AEC)

Ohlinger, L.A.

1962-08-01T23:59:59.000Z

300

The Effect of Bubbles Released from a Melting Ice Wall on the Melt-Driven Convection in Salt Water  

Science Conference Proceedings (OSTI)

The buoyancy created by the release of air bubbles from melting glacial ice walls results from both the upward drag of the bubbles and the density defect caused by the steady-state distribution of bubbles in the water. Calculations using typical ...

Edward G. Josberger

1980-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "jet bubbling reactor" 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

Composite Octet Searches with Jet Substructure  

Science Conference Proceedings (OSTI)

Many new physics models with strongly interacting sectors predict a mass hierarchy between the lightest vector meson and the lightest pseudoscalar mesons. We examine the power of jet substructure tools to extend the 7 TeV LHC sensitivity to these new states for the case of QCD octet mesons, considering both two gluon and two b-jet decay modes for the pseudoscalar mesons. We develop both a simple dijet search using only the jet mass and a more sophisticated jet substructure analysis, both of which can discover the composite octets in a dijet-like signature. The reach depends on the mass hierarchy between the vector and pseudoscalar mesons. We find that for the pseudoscalar-to-vector meson mass ratio below approximately 0.2 the simple jet mass analysis provides the best discovery limit; for a ratio between 0.2 and the QCD-like value of 0.3, the sophisticated jet substructure analysis has the best discovery potential; for a ratio above approximately 0.3, the standard four-jet analysis is more suitable.

Bai, Yang; /SLAC; Shelton, Jessie; /Yale U.

2012-02-14T23:59:59.000Z

302

An Engineering Test Reactor  

SciTech Connect

A relatively inexpensive reactor for the specific purpose of testing a sub-critical portion of another reactor under conditions that would exist during actual operation is discussed. It is concluded that an engineering tool for reactor development work that bridges the present gap between exponential and criticality experiments and the actual full scale operating reactor is feasible. An example of such a test reactor which would not entail development effort to ut into operation is depicted.

Fahrner, T.; Stoker, R.L.; Thomson, A.S.

1951-03-16T23:59:59.000Z

303

Numerical Simulations of Boiling Jet Impingement Cooling in Power Electronics  

DOE Green Energy (OSTI)

This paper explores turbulent boiling jet impingement for cooling power electronic components in hybrid electric vehicles.

Narumanchi, S.; Troshko, A.; Hassani, V.; Bharathan, D.

2006-12-01T23:59:59.000Z

304

THE RHIC HYDROGEN JET LUMINESCENCE MONITOR.  

DOE Green Energy (OSTI)

A hydrogen jet polarimeter was developed for the RHIC accelerator to improve the process of measuring polarization. Particle beams intersecting with gas molecules can produce light by the process known as luminescence. This light can then be focused, collected, and processed giving important information such as size, position, emittance, motion, and other parameters. The RHIC hydrogen jet polarimeter was modified in 2005 with specialized optics, vacuum windows, light transport, and a new camera system making it possible to monitor the luminescence produced by polarized protons intersecting the hydrogen beam. This paper describes the configuration and preliminary measurements taken using the RHIC hydrogen jet polarimeter as a luminescence monitor.

RUSSO,T.; BELLAVIA, S.; GASSNER, D.; THIEBERGER, P.; TRBOJEVIC, D.; TSANG, T.

2007-06-25T23:59:59.000Z

305

Jet spoiler arrangement for wind turbine  

DOE Patents (OSTI)

An air jet spoiler arrangement is provided for a Darrieus-type vertical axis wind-powered turbine. Air is drawn into hollow turbine blades through air inlets at the ends thereof and is ejected in the form of air jets through small holes or openings provided along the lengths of the blades. The air jets create flow separation at the surfaces of the turbine blades, thereby inducing stall conditions and reducing the output power. A feedback control unit senses the power output of the turbine and controls the amount of air drawn into the air inlets accordingly.

Cyrus, Jack D. (Corrales, NM); Kadlec, Emil G. (Albuquerque, NM); Klimas, Paul C. (Albuquerque, NM)

1985-01-01T23:59:59.000Z

306

Jet spoiler arrangement for wind turbine  

DOE Patents (OSTI)

An air jet spoiler arrangement is provided for a Darrieus-type vertical axis wind-powered turbine. Air is drawn into hollow turbine blades through air inlets at the end thereof and is ejected in the form of air jets through small holes or openings provided along the lengths of the blades. The air jets create flow separation at the surfaces of the turbine blades, thereby including stall conditions and reducing the output power. A feedback control unit senses the power output of the turbine and controls the amount of air drawn into the air inlets accordingly.

Cyrus, J.D.; Kadlec, E.G.; Klimas, P.C.

1983-09-15T23:59:59.000Z

307

Study of falling-jet flash evaporators  

DOE Green Energy (OSTI)

Experimental results of flash evaporation from sheets of water, 3.2 mm and 6.3 mm thick and 27.9 cm wide, falling freely in the presence of their own vapor, are reported. With no flashing the jets fall in coherent sheets, but with flashing the jets were observed to spread and break up into droplets. Flashing was characterized by an effectiveness parameter, which was found to increase with increasing water temperature and jet length. Variations in water flow rate and heat flux did not influence the effectiveness appreciably.

Kreith, F.; Olson, D.A.; Bharathan, D.; Green, H.J.

1982-11-01T23:59:59.000Z

308

Reactor Pressure Vessel Task of Light Water Reactor Sustainability...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Reactor Pressure Vessel Task of Light Water Reactor Sustainability Program: Milestone Report on Materials and Machining of Specimens for the ATR-2 Experiment Reactor Pressure...

309

Bubbles, Jumps, and Scaling from Properly Anticipated Prices  

E-Print Network (OSTI)

Prices in financial markets exhibit extreme jumps far more often than can be accounted for by external news. Further, magnitudes of price changes are correlated over long times. These so called stylized facts are quantified by scaling laws similar to, for example, turbulent fluids. They are believed to reflect the complex interactions of heterogenous agents which give rise to irrational herding. Therefore, the stylized facts have been argued to provide evidence against the efficient market hypothesis which states that prices rapidly reflect available information and therefore are described by a martingale. Here we show, that in very simple bidding processes efficiency is not opposed to, but causative to scaling properties observed in real markets. Thereby, we link the stylized facts not only to price efficiency, but also to the economic theory of rational bubbles. We then demonstrate effects predicted from our normative model in the dynamics of groups of real human subjects playing a modified minority game. A...

Patzelt, Felix

2013-01-01T23:59:59.000Z

310

Investigation of a Sodium Vapor Compressor Jet for Nuclear Propulsion of Aircraft  

SciTech Connect

?Analysis indicates that, in order to achieve supersonic flight with nuclear powered aircraft, a reactor -power plant combination capable of operating at temperatures considerably in excess of current practice must be developed. It is pointed out that there exist two general avenues of approach toward the goal of attaining high temperature reactors and power plants. The first approach involves the continuation and augmentation of research along the lines pursued by the conventional turbo-jet engine manufacturer, namely a search for material coatings or materials that will retain structural strength in high temperature oxidizing atmospheres. The second approach seeks to take advantage of the peculiar characteristics of the compressor-jet engine that permit the operation of the high temperature components in a non-oxidizing atmosphere. The results of a preliminary design study of a supersonic aircraft powered by a high temperature sodium, liquid vapor compressor -jet engine are summarized. The analysis considered, in as much detail as was warranted by the limited experimental information available, the characteristics of the reactor, power plant and airframe involved in determining performance. This study has been conducted for the purpose of guiding future, long -t e r rn , research work along the lines of high temperature reactors and power plants for aircraft propulsion. The sodium vapor compressor -jet is not presented as an engine that is presently considered feasible nor is any attempt made to establish a time table for its development. ?The present status of reactor -power plant combinations of the type discussed in this report is such that the configurations presented and the thermodynamic requirements set forth are highly c onj ectural. However, in light of the promising results thus far obtained from very limited experimentation in the field of high temperature materials not subject to oxidizing atmospheres, it appears worthwhile to continue a research effort along these lines in the expectation of making high temperature, high performance aircraft a reality. This report is based upon studies conducted for the Atomic Energy Commission under Contract AT-40-l-GEN-1064. These studies were concluded on September 1, 1951, and were informally made available to the Aircraft Nuclear Propulsion Group at ORNL at that time.

Schwartz, H.

1953-06-25T23:59:59.000Z

311

Memorandum on Chemical Reactors and Reactor Hazards  

SciTech Connect

Two important problems in the investigation of reactor hazards are the chemical reactivity of various materials employed in reactor construction and the chracteristics of heat transfer under transient conditions, specifically heat transfer when driven by an exponentially increasing heat source (exp t/T). Although these problems are independent of each other, when studied in relation to reactor hazards they may occur in a closely coupled sequence. For example the onset of a dangerous chemical reactor may be due to structural failure of various reactor components under an exponentially rising heat source originating with a runaway nuclear reactor. For this reason, these two problems should eventually be studied together after an exploratory experimental survey has been made in which they are considered separately.

Mills, M.M.; Pearlman, H.; Ruebsamen, W.; Steele, G., Chrisney, J.

1951-07-05T23:59:59.000Z

312

Jet production in muon scattering at Fermilab E665  

SciTech Connect

Measurements of multi-jet production rates from Muon-Nucleon and Muon-Nuclei scattering at Fermilab-E665 are presented. Jet rates are defined by the JADE clustering algorithm. Rates in Muon-Nucleon deep-inelastic scattering are compared to Monte Carlo model predictions. Preliminary results from jet production on heavy targets, in the shadowing region, show a higher suppression of two-forward jets as compared to one-forward jet production.

Salgado, C.W.; E665 Collaboration

1993-11-01T23:59:59.000Z

313

Stochastic Dynamics of the Midlatitude Atmospheric Jet  

Science Conference Proceedings (OSTI)

The innate tendency of the background straining field of the midlatitude atmospheric jet to preferentially amplify a subset of disturbances produces a characteristic response to stochastic perturbation whether the perturbations are internally ...

Brian F. Farrell; Peteros J. Ioannou

1995-05-01T23:59:59.000Z

314

Internal shocks model for microquasar jets  

E-Print Network (OSTI)

We present an internal shocks model to investigate particle acceleration and radiation production in microquasar jets. The jet is modelled with discrete ejecta at various time intervals. These ejecta (or 'shells') may have different properties including the bulk velocity. Faster shells can catch up and collide with the slower ones, thus giving rise to shocks. The particles are accelerated inside the shocked plasma. Each collision results in a new shell, which may take part in any subsequent collisions as well as radiate due to synchrotron radiation. Almost continuous energy dissipation along the jet can be obtained with a large number of shell collisions. We investigate the spectral energy distribution of such jets as well as the physical significance of various parameters (e.g. the time interval between ejections and the shell size).

Omar Jamil; Rob Fender; Christian Kaiser

2008-11-20T23:59:59.000Z

315

Jet Fuel from Bio-Diesel  

NLE Websites -- All DOE Office Websites (Extended Search)

Jet Fuel from Bio-Diesel Background Due to concerns with limited resources of petroleum-based fuels, the demand for using renewable feedstocks, such as vegetable oils and animal...

316

Current-driven instability of magnetic jets  

E-Print Network (OSTI)

MHD instabilities can be responsible for the complex morphology of astrophysical jets. We consider the stability properties of jets containing both the azimuthal and axial field of subthermal strength. The presence of the magnetic field with complex topology in jets is suggested by theoretical models and it is consistent with recent observations. Stability is discussed by means of a linear analysis of the ideal MHD equations.We argue that, in the presence of azimuthal and axial magnetic fields, the jet is always unstable to non-axisymmetric perturbations. Stabilization does not occur even if the strengths of these field components are comparable. If the axial field is weaker than the azimuthal one, instability occurs for perturbations with any azimuthal wave number $m$, and the growth rate reach a saturation value for small values of $m$. If the axial field is stronger than the toroidal one, the instability shows off for perturbations with relatively large $m$.

Bonanno, Alfio

2010-01-01T23:59:59.000Z

317

Jets (relativistic and non) in astrophysics  

E-Print Network (OSTI)

Let's take stock of the situation on one of the most studied astrophysical phenomena during the latest years: the jets escaping from protostars, stellar singularities, GRB and active galactic nuclei.

Foschini, Luigi

2010-01-01T23:59:59.000Z

318

String model for spinning quark jets  

Science Conference Proceedings (OSTI)

A string model of quark hadronization, taking the quark spin degree of freedom into account, is proposed. The method for using the model in a Monte-Carlo code for jet generation is given.

Artru, X.; Belghobsi, Z. [Universite de Lyon, CNRS/IN2P3 and Universite Lyon 1, Institut de Physique Nucleaire de Lyon, Laboratoire de Physique Theorique, Universite de Jijel (Algeria)

2012-06-27T23:59:59.000Z

319

Mixing Processes within the Polar Night Jet  

Science Conference Proceedings (OSTI)

Lagrangian material line simulations are performed using U.K. Meteorological Office assimilated winds and temperatures to examine mixing processes in the middle- and lower-stratospheric polar night jet during the 1992 Southern Hemisphere spring ...

R. Bradley Pierce; T. Duncan Fairlie; William L. Grose; Richard Swinbank; Alan O'Neill

1994-10-01T23:59:59.000Z

320

Developments of the ATLAS Jet Trigger  

E-Print Network (OSTI)

There have been a lot of recent changes in the ATLAS jet trigger. The standard strategy, based on Regions Of Interest, is not well-suited for multi-jet events since it leads to pathologies and efficiency losses. This philosophy has been changed for the jet trigger, and we now have the possibility of unpacking the full calorimeter at Event Filter and (even for a small subset of the events) at an intermediate level between Level-1 and Level-2. We also moved to the use of calibrated scale at trigger level, and to the application of noise cuts to reduce rate spikes. We will present the performance of the jet trigger in 2011, when most of these changes were operational

Lopes, L; The ATLAS collaboration

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "jet bubbling reactor" 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

Performance of the ATLAS Jet Trigger  

E-Print Network (OSTI)

There have been a lot of recent changes in the ATLAS jet trigger. The standard strategy, based on Regions Of Interest, is not well-suited for multi-jet events since it leads to pathologies and efficiency losses. This philosophy has been changed for the jet trigger, and we now have the possibility of unpacking the full calorimeter at Event Filter and (even for a small subset of the events) at an intermediate level between Level-1 and Level-2. We also moved to the use of calibrated scale at trigger level, and to the application of noise cuts to reduce rate spikes. We will present the performance of the jet trigger in 2011, when most of these changes were operational

Lopes, L; The ATLAS collaboration

2012-01-01T23:59:59.000Z

322

The Initial Composition of Jet Condensation Trails  

Science Conference Proceedings (OSTI)

Physicochemical processes that generate and transform aerosols in jet aircraft plumes are discussed on the basis of theoretical models and recent observations of young contrails in the upper troposphere. The initial evolution of optical depth and ...

B. Kärcher; Th Peter; U. M. Biermann; U. Schumann

1996-11-01T23:59:59.000Z

323

Persistent Multiple Jets and PV Staircase  

Science Conference Proceedings (OSTI)

The persistence of multiple jets is investigated with a quasigeostrophic, two-layer, ?-plane channel model. Linearly unstable normal modes are found to be capable of qualitatively describing the eddy fluxes of the nonlinear model. For a ...

Changhyun Yoo; Sukyoung Lee

2010-07-01T23:59:59.000Z

324

Advanced thermally stable jet fuels. Technical progress report, April 1995--June 1995  

Science Conference Proceedings (OSTI)

Research continued on thermally stable jet fuel from coal liquids and petroleum distillates. The oxidative and thermal stabilities of ten fuels have been studied by differential scanning calorimetry and in microautoclave reactors. The compositions of the stressed fuels (as well as the unreacted fuels) were characterized by gas chromatography and gas chromatography/mass spectrometry. In addition, simulated distillation curves were determined by thermogravimetric analysis. The product distributions and reaction mechanisms for the thermal decomposition of n-alkanes in near-critical and supercritical regions were studied. The emphasis of the work in this reporting period has been placed on reaction mechanisms and product distributions. Work is continuing on obtaining additional {sup 13}C-labeled jet fuel components for future thermal stressing studies. Compounds of current interest include 6-{sup 13}C-dodecane and 1-cyclohexyl-1-{sup 13}C-hexane. Further analysis of the formation of solids from the thermal stressing of decane and decalin has been performed.

Schobert, H.H.; Eser, S.; Boehman, A.; Song, C. [and others

1995-08-01T23:59:59.000Z

325

New results on jet fragmentation at CDF  

SciTech Connect

Presented are the latest results of jet fragmentation studies at the Tevatron using the CDF Run II detector. Studies include the distribution of transverse momenta (Kt) of particles jets, two-particle momentum correlations, and indirectly global event shapes in p{bar p} collisions. Results are discussed within the context of recent Next-to-Leading Log calculations as well as earlier experimental results from the Tevatron and e{sup +}e{sup -} colliders.

Jindariani, Sergo; /Florida U.

2006-12-01T23:59:59.000Z

326

Dark Matter Jets at the LHC  

SciTech Connect

We argue that dark matter particles which have strong interactions with the Standard Model particles are not excluded by current astrophysical constraints. These dark matter particles have unique signatures at colliders; instead of missing energy, the dark matter particles produce jets. We propose a new search strategy for such strongly interacting particles by looking for a signal of two trackless jets. We show that suitable cuts can plausibly allow us to find these signals at the LHC even in early data.

Bai, Yang; /SLAC; Rajaraman, Arvind; /UC, Irvine

2012-03-28T23:59:59.000Z

327

Supersonic Jet Excitation using Flapping Injection  

E-Print Network (OSTI)

Supersonic jet noise reduction is important for high speed military aircraft. Lower acoustic levels would reduce structural fatigue leading to longer lifetime of the jet aircraft. It is not solely structural aspects which are of importance, health issues of the pilot and the airfield per- sonnel are also very important, as high acoustic levels may result in severe hearing damage. It remains a major challenge to reduce the overall noise levels of the aircraft, where the supersonic exhaust is the main noise source for near ground operation. Fluidic injection into the supersonic jet at the nozzle exhaust has been shown as a promising method for noise reduction. It has been shown to speed up the mix- ing process of the main jet, hence reducing the kinetic energy level of the jet and the power of the total acoustic radiation. Furthermore, the interaction mechanism between the fluidic injection and the shock structure in the jet exhaust plays a crucial role in the total noise radia- tion. In this study, LES is used...

Hafsteinsson, Haukur; Andersson, Niklas; Cuppoletti, Daniel; Gutmark, Ephraim; Prisell, Erik

2013-01-01T23:59:59.000Z

328

Gas generation and bubble formation model for crystalline silicotitanate ion exchange columns  

SciTech Connect

The authors developed a transient model to describe the process of gas generation due to radiolysis and bubble formation in crystalline silicotitanate (CST) ion exchange (IX) columns using the Aspen Custom Modeler (ACM) software package. The model calculates gas concentrations and onset of bubble formation for large CST IX columns. The calculations include cesium loading as a function of time, gas generation as a function of cesium loading, and bubble formation as a function of gas solubility. This report summarizes the model development and predictions.

Hang, T.

2000-07-19T23:59:59.000Z

329

U.S. Exports of Kerosene-Type Jet Fuel (Thousand Barrels per Day)  

U.S. Energy Information Administration (EIA)

Kerosene-Type Jet Fuel Exports; Kerosene-Type Jet Fuel Exports by Destination; Kerosene-Type Jet Fuel Supply and Disposition ...

330

Basic and Applied Science Research Reactors - Reactors designed...  

NLE Websites -- All DOE Office Websites (Extended Search)

BORAX-III lighting Arco, Idaho (Press Release) Heavy Water and Graphite Reactors Fast Reactor Technology Integral Fast Reactor Argonne Reactor Tree CP-1 70th Anniversary CP-1 70th...

331

Jet energy scale determination in the D0 experiment  

E-Print Network (OSTI)

The calibration of jet energy measured in the \\DZero detector is presented, based on ppbar collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider. Jet energies are measured using a sampling calorimeter composed of uranium and liquid argon as the passive and active media, respectively. This paper describes the energy calibration of jets performed with photon+jet, Z+jet and dijet{} events, with jet transverse momentum pT > 6 GeV and pseudorapidity range |eta| energy in simulation and in particular of the effects due to the flavor of the parton originating the jet, correcting biases up to 3%-4% in jets with low pT originating from gluons and up to 6%-8% in jets from b quarks.

D0 Collaboration

2013-12-24T23:59:59.000Z

332

Attrition reactor system  

DOE Patents (OSTI)

A reactor vessel for reacting a solid particulate with a liquid reactant has a centrifugal pump in circulatory flow communication with the reactor vessel for providing particulate attrition, resulting in additional fresh surface where the reaction can occur.

Scott, Charles D. (Oak Ridge, TN); Davison, Brian H. (Knoxvile, TN)

1993-01-01T23:59:59.000Z

333

Reactor Sharing Program  

Science Conference Proceedings (OSTI)

Progress achieved at the University of Florida Training Reactor (UFTR) facility through the US Department of Energy's University Reactor Sharing Program is reported for the period of 1991--1992.

Vernetson, W.G.

1993-01-01T23:59:59.000Z

334

Guidebook to nuclear reactors  

SciTech Connect

A general introduction to reactor physics and theory is followed by descriptions of commercial nuclear reactor types. Future directions for nuclear power are also discussed. The technical level of the material is suitable for laymen.

Nero, A.V. Jr.

1976-05-01T23:59:59.000Z

335

Attrition reactor system  

DOE Patents (OSTI)

A reactor vessel for reacting a solid particulate with a liquid reactant has a centrifugal pump in circulatory flow communication with the reactor vessel for providing particulate attrition, resulting in additional fresh surface where the reaction can occur. 2 figures.

Scott, C.D.; Davison, B.H.

1993-09-28T23:59:59.000Z

336

AIAA Paper 2006-0102 Analysis of Jet Effects on Co-Flow Jet Airfoil  

E-Print Network (OSTI)

.-C. Zha, C. Paxton, A. Conley, A. Wells, and B. Carroll, "Effect of Injection Slot Size on High in this paper to analyze the jet effect on co-flow jet airfoil with injection and suction and the airfoil with injection only. The ducts reaction forces formulations to be included for lift and drag calculation

Zha, Gecheng

337

Formation of NOx precursors during Chinese pulverized coal pyrolysis in an arc plasma jet  

Science Conference Proceedings (OSTI)

The formation of NOx precursors (HCN and NH{sub 3}) from the pyrolysis of several Chinese pulverized coals in an arc plasma jet was investigated through both thermodynamic analysis of the C-H-O-N system and experiments. Results of thermodynamic analysis show that the dominant N-containing gaseous species is HCN together with a small amount of ammonia above the temperature of 2000 K. The increase of H content advances the formation of HCN and NH{sub 3}, but the yields of HCN and NH{sub 3} are decreased with a high concentration of O in the system. These results are accordant with the experimental data. The increasing of input power promotes the formation of HCN and NH{sub 3} from coal pyrolysis in an arc plasma jet. Tar-N is not formed during the process. The yield of HCN changes insignificantly with the changing of the residence time of coal particles in the reactor, but that of NH{sub 3} decreases as residence times increase because of the relative instability at high temperature. Adsorption and gasification of CO{sub 2} on the coal surface also can restrain the formation of HCN and NH{sub 3} compare to the results in an Ar plasma jet. Yields of HCN and NH{sub 3} are sensitive to the coal feeding rate, indicating that NOx precursors could interact with the nascent char to form other N-containing species. The formation of HCN and NH{sub 3} during coal pyrolysis in a H{sub 2}/Ar plasma jet are not dependent on coal rank. The N-containing gaseous species is released faster than others in the volatiles during coal pyrolysis in an arc plasma jet, and the final nitrogen content in the char is lower than that in the parent coal, which it is independent of coal type. 16 refs., 9 figs., 1 tab.

Wei-ren Bao; Jin-cao Zhang; Fan Li; Li-ping Chang [Taiyuan University of Technology, Taiyuan (China). Key Laboratory of Coal Science and Technology

2007-08-15T23:59:59.000Z

338

Scaling Laws for Reduced-Scale Tests of Pulse Jet Mixing Systems in Non-Newtonian Slurries: Gas Retention and Release Behavior  

Science Conference Proceedings (OSTI)

The Waste Treatment Plant (WTP) under construction at the Hanford Site will use pulse jet mixer (PJM) technology for mixing and gas retention control applications in tanks expected to contain waste slurries exhibiting a non-Newtonian rheology. This paper presents the results of theoretical and experimental studies performed to establish the methodology to perform reduced-scale gas retention and release tests with PJM systems in non-Newtonian fluids with gas generation. The technical basis for scaled testing with unsteady jet mixing systems in gas-generating non-Newtonian fluids is presented in the form of a bubble migration model that accounts for the gas generation rate, the average bubble rise velocity, and the geometry of the vessel. Scaling laws developed from the model were validated with gas holdup and release tests conducted at three scales: large scale, 1/4 scale, and 1/9 scale. Experiments were conducted with two non-Newtonian simulants with in-situ gas generation by decomposition of hydrogen peroxide. The data were compared non-dimensionally, and the important scale laws were examined. From these results, scaling laws are developed which allow the design of mixing systems at a reduced scale.

Stewart, Charles W.; Meyer, Perry A.; Kurath, Dean E.; Barnes, Steven M.

2006-03-02T23:59:59.000Z

339

NEUTRONIC REACTOR POWER PLANT  

DOE Patents (OSTI)

This patent relates to a nuclear reactor power plant incorporating an air-cooled, beryllium oxide-moderated, pebble bed reactor. According to the invention means are provided for circulating a flow of air through tubes in the reactor to a turbine and for directing a sidestream of the circu1ating air through the pebble bed to remove fission products therefrom as well as assist in cooling the reactor. (AEC)

Metcalf, H.E.

1962-12-25T23:59:59.000Z

340

Bubbles Hot Spring Pool & Spa Low Temperature Geothermal Facility | Open  

Open Energy Info (EERE)

Bubbles Hot Spring Pool & Spa Low Temperature Geothermal Facility Bubbles Hot Spring Pool & Spa Low Temperature Geothermal Facility Jump to: navigation, search Name Bubbles Hot Spring Pool & Spa Low Temperature Geothermal Facility Facility Bubbles Hot Spring Sector Geothermal energy Type Pool and Spa Location Catron County, New Mexico Coordinates 34.1515173°, -108.4276047° 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":[]}

Note: This page contains sample records for the topic "jet bubbling reactor" 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

Mixing State of Submicrometer Sea Spray Particles Enriched by Insoluble Species in Bubble-Bursting Experiments  

Science Conference Proceedings (OSTI)

Measurements of size distribution, hygroscopicity, and volatility of submicrometer sea spray particles produced by the bubble busting of artificial and natural seawater were conducted to determine their mixing state and volume fractions of ...

Ji Yeon Park; Sungil Lim; Kihong Park

2014-01-01T23:59:59.000Z

342

Effect of Air Bubbles on Absorption of Solar Radiation by Water Droplets  

Science Conference Proceedings (OSTI)

It was suggested that absorption by a weakly absorbing droplet may be increased substantially by the presence of air bubbles within a droplet. The authors use an exact solution of the scattering of electromagnetic waves by a spherical particle ...

Petr Chýlek; Gorden Videen; Dat Ngo

1998-02-01T23:59:59.000Z

343

Characterization of single and colliding laser-produced plasma bubbles using Thomson scattering and proton radiography  

E-Print Network (OSTI)

Time-resolved measurements of electron and ion temperatures using Thomson scattering have been combined with proton radiography data for comprehensive characterization of individual laser-produced plasma bubbles or the ...

Rosenberg, Michael Jonathan

344

The Role of Whitecap Bubbles in Air–Sea Heat and Moisture Exchange  

Science Conference Proceedings (OSTI)

In high winds, the sea surface is no longer simply connected. Whitecap bubbles and sea spray provide additional surfaces that may enhance the transfer of any quantity normally exchanged at the air–sea interface. This paper investigates the role ...

Edgar L. Andreas; Edward C. Monahan

2000-02-01T23:59:59.000Z

345

Bubble Convection Experiments with a Semi-implicit Formulation of the Euler Equations  

Science Conference Proceedings (OSTI)

Atmospheric models based on the Euler equations exist and are used occasionally to carry out numerical experiments. Such a model is used here to simulate the motion of warm bubbles in a dry isentropic atmosphere. For the time integration, this ...

André Robert

1993-07-01T23:59:59.000Z

346

Analysis on electro-thermal property of micro-bubble generator using carbon nanotube heating elements  

Science Conference Proceedings (OSTI)

Localized high temperature due to Joule heating in Carbon Nanotubes (CNTs) can generate micron-sized bubbles. Electro-thermal property of CNTs-based microbubble generator is characterized by finite element analysis in this paper. Water circumstance with ...

Wenli Zhou; Sanping Wan; Chao Zhu

2009-01-01T23:59:59.000Z

347

Formation of seep bubble plumes in the Coal Oil Point seep field  

E-Print Network (OSTI)

hydrocarbon seeps near Coal Oil Point, California. Marof seep bubble plumes in the Coal Oil Point seep field Irameasurement system in the Coal Oil Point seep field in the

Leifer, Ira; Culling, Daniel

2010-01-01T23:59:59.000Z

348

A Free-Flooding Acoustical Resonator for Measurement of Bubble Size Distributions  

Science Conference Proceedings (OSTI)

An instrument for the measurement of bubble size distributions is described. The sensing element exploits the free-flooding resonator design of Medwin with modifications to overcome the limitations in the original implementation, especially those ...

David M. Farmer; Svein Vagle; A. Donald Booth

1998-10-01T23:59:59.000Z

349

Molecular dynamics simulation of deuterium trapping and bubble formation in tungsten  

E-Print Network (OSTI)

Molecular dynamics simulation of deuterium trapping and bubble formation in tungsten Xue Yang using classical molecular dynamic methods. " Low energy deuterium atoms tend to affix to high environment. The deuterium bombardment of monocrystalline tungsten was modeled by molecular dynamics

Harilal, S. S.

350

Investigation of the eigenfrequencies of two interacting gas bubbles using the direct-numerical-simulation technique  

E-Print Network (OSTI)

The recent theory regarding the eigenfrequencies of two mutually interacting gas bubbles in an acoustic field is verified numerically. The theory given by Ida [e-Print physics/0111133; (submitted)] predicts the existence of three eigenfrequencies per bubble, which make the phase difference between a bubble's pulsation and an external sound be $\\pi / 2$, while readymade theories predict only two natural frequencies. The direct-numerical-simulation technique, in which the compressible Navier-Stokes equation is selected as the governing equation, is employed for numerical experiments. We investigate the eigenfrequencies by observing the direction of the secondary Bjerknes force acting between pulsating bubbles, which changes as the driving frequency varies. The numerical results show that the theoretical prediction is valid at least in a qualitative sense.

Ida, M

2001-01-01T23:59:59.000Z

351

Bubble behavior in subcooled flow boiling on surfaces of variable wettability  

E-Print Network (OSTI)

Flow boiling is important in energy conversion and thermal management due to its potential for very high heat fluxes. By improving understanding of the conditions leading to bubble departure, surfaces can be designed that ...

Tow, Emily W

2012-01-01T23:59:59.000Z

352

Measurements with an Automatically Recording Inverted Echo Sounder; ARIES and the Bubble Clouds  

Science Conference Proceedings (OSTI)

We report here analysis of the first observations with a new instrument, ARIES, designed to record the acoustic backscatter from bubble clouds at several levels below the surface of the ocean. The instrument is deployed on a subsurface mooring ...

S. A. Thorpe

1986-08-01T23:59:59.000Z

353

At Solar System's Edge, There be...Bubbles? - NERSC Science News, June 9,  

NLE Websites -- All DOE Office Websites (Extended Search)

At Solar System's At Solar System's Edge, There be...Bubbles? At Solar System's Edge, There be...Bubbles? Voyagers, Computer Models Find Surprising Magnetic Froth June 9, 2011 | Tags: Astrophysics, Franklin, Fusion Energy, Fusion Energy Sciences (FES), Hopper Margie Wylie, mwylie@lbl.gov, +1 510 486 7421 This animated computer simulation shows how magnetic bubbles form at the edge of our solar system. It was created on NERSC's "Franklin" supercomputer using 8,192 processor cores simultaneously running for 20 hours. (Credit: James F. Drake) NASA's Voyager probes have reached the end of our solar system where they've found neither giants nor dragons, but something nearly as surprising-a turbulent froth of magnetic bubbles. Using new computer models to analyze Voyager data, scientists computing at

354

High solids fermentation reactor  

DOE Patents (OSTI)

A fermentation reactor and method for fermentation of materials having greater than about 10% solids. The reactor includes a rotatable shaft along the central axis, the shaft including rods extending outwardly to mix the materials. The reactor and method are useful for anaerobic digestion of municipal solid wastes to produce methane, for production of commodity chemicals from organic materials, and for microbial fermentation processes.

Wyman, Charles E. (Lakewood, CO); Grohmann, Karel (Littleton, CO); Himmel, Michael E. (Littleton, CO); Richard, Christopher J. (Lakewood, CO)

1993-01-01T23:59:59.000Z

355

FAST NEUTRON REACTOR  

DOE Patents (OSTI)

A reactor comprising fissionable material in concentration sufficiently high so that the average neutron enengy within the reactor is at least 25,000 ev is described. A natural uranium blanket surrounds the reactor, and a moderating reflector surrounds the blanket. The blanket is thick enough to substantially eliminate flow of neutrons from the reflector.

Soodak, H.; Wigner, E.P.

1961-07-25T23:59:59.000Z

356

NUCLEAR REACTOR CONTROL SYSTEM  

DOE Patents (OSTI)

A control system is described for a nuclear reactor using enriched uranium fuel of the type of the swimming pool and other heterogeneous nuclear reactors. Circuits are included for automatically removing and inserting the control rods during the course of normal operation. Appropriate safety circuits close down the nuclear reactor in the event of emergency.

Epler, E.P.; Hanauer, S.H.; Oakes, L.C.

1959-11-01T23:59:59.000Z

357

Bubble statistics and coarsening dynamics for quasi-two dimensional foams with increasing liquid content  

E-Print Network (OSTI)

We report on the statistics of bubble size, topology, and shape and on their role in the coarsening dynamics for foams consisting of bubbles compressed between two parallel plates. The design of the sample cell permits control of the liquid content, through a constant pressure condition set by the height of the foam above a liquid reservoir. We find that in the scaling state, all bubble distributions are independent not only of time but also of liquid content. For coarsening, the average rate decreases with liquid content due to the blocking of gas diffusion by Plateau borders inflated with liquid. By observing the growth rate of individual bubbles, we find that von Neumann's law becomes progressively violated with increasing wetness and with decreasing bubble size. We successfully model this behavior by explicitly incorporating the border blocking effect into the von Neumann argument. Two dimensionless bubble shape parameters naturally arise, one of which is primarily responsible for the violation of von Neumann's law for foams that are not perfectly dry.

A. E. Roth; C. D. Jones; D. J. Durian

2012-06-30T23:59:59.000Z

358

The Argonaut Reactor - Reactors designed/built by Argonne National  

NLE Websites -- All DOE Office Websites (Extended Search)

Achievements > Achievements > Argonne Reactors > Training Reactors About Director's Welcome Organization Achievements Highlights Fact Sheets, Brochures & Other Documents Multimedia Library Visit Argonne Work with Argonne Contact us Nuclear Energy Why Nuclear Energy? Why are some people afraid of Nuclear Energy? How do nuclear reactors work? Cheaper & Safer Nuclear Energy Helping to Solve the Nuclear Waste Problem Nuclear Reactors Nuclear Reactors Early Exploration Training Reactors Basic and Applied Science Research LWR Technology Development BORAX-III lighting Arco, Idaho (Press Release) Heavy Water and Graphite Reactors Fast Reactor Technology Integral Fast Reactor Argonne Reactor Tree CP-1 70th Anniversary CP-1 70th Anniversary Argonne's Nuclear Science and Technology Legacy

359

Nuclear reactor overflow line  

DOE Patents (OSTI)

The overflow line for the reactor vessel of a liquid-metal-cooled nuclear reactor includes means for establishing and maintaining a continuous bleed flow of coolant amounting to 5 to 10% of the total coolant flow through the overflow line to prevent thermal shock to the overflow line when the reactor is restarted following a trip. Preferably a tube is disposed concentrically just inside the overflow line extending from a point just inside the reactor vessel to an overflow tank and a suction line is provided opening into the body of liquid metal in the reactor vessel and into the annulus between the overflow line and the inner tube.

Severson, Wayne J. (Pittsburgh, PA)

1976-01-01T23:59:59.000Z

360

Reactor vessel support system  

DOE Patents (OSTI)

A reactor vessel support system includes a support ring at the reactor top supported through a box ring on a ledge of the reactor containment. The box ring includes an annular space in the center of its cross-section to reduce heat flow and is keyed to the support ledge to transmit seismic forces from the reactor vessel to the containment structure. A coolant channel is provided at the outside circumference of the support ring to supply coolant gas through the keyways to channels between the reactor vessel and support ledge into the containment space.

Golden, Martin P. (Trafford, PA); Holley, John C. (McKeesport, PA)

1982-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "jet bubbling reactor" 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

Radiation Effects on Transport and Bubble Formation in Silicate Glasses  

DOE Green Energy (OSTI)

Using advanced magnetic resonance spectroscopies and small-cluster modeling, atomic structure of radiation-induced point defects in alkali borate, silicate, and borosilicate glasses is fully characterized. It is shown that in boron-containing glasses, most of these point defects are electrons/holes trapped by cation/anion vacancies, such as O1 - - O3 + valence-alternation pairs. In microscopically phase-separated borosilicate glasses, radiation-induced defects are found to cluster at the interface between the borate and silicate phases. Reaction and diffusion dynamics of defect-annealing interstitial hydrogen atoms in boron and silica oxide glasses are studied. The yield of radiolytic O2 is estimated. This oxygen is shown to be the final product of triplet exciton decay. Plausible mechanisms for the oxygen bubble formation are put forward. Two practical conclusions relevant for the EMSP mission are made: First, the yield of radiolytic oxygen is shown to be too low to interfere with the storage of vitrified radioactive waste in the first 10 Kyr. Second, microscopic phase separation is demonstrated to increase both the chemical and radiation stability of borosilicate glass.

Trifunac, A.D.; Shkrob, I.A.; Werst, D.W.

2001-12-31T23:59:59.000Z

362

PROBING THE ROSETTE NEBULA STELLAR BUBBLE WITH FARADAY ROTATION  

SciTech Connect

We report the results of Faraday rotation measurements of 23 background radio sources whose lines of sight pass through or close to the Rosette Nebula. We made linear polarization measurements with the Karl G. Jansky Very Large Array (VLA) at frequencies of 4.4 GHz, 4.9 GHz, and 7.6 GHz. We find the background Galactic contribution to the rotation measure in this part of the sky to be +147 rad m{sup -2}. Sources whose lines of sight pass through the nebula have an excess rotation measure of 50-750 rad m{sup -2}, which we attribute to the plasma shell of the Rosette Nebula. We consider two simple plasma shell models and how they reproduce the magnitude and sign of the rotation measure, and its dependence on distance from the center of the nebula. These two models represent different modes of interaction of the Rosette Nebula star cluster with the surrounding interstellar medium. Both can reproduce the magnitude and spatial extent of the rotation measure enhancement, given plausible free parameters. We contend that the model based on a stellar bubble more closely reproduces the observed dependence of rotation measure on distance from the center of the nebula.

Savage, Allison H.; Spangler, Steven R.; Fischer, Patrick D. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States)] [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States)

2013-03-01T23:59:59.000Z

363

ON THE STRUCTURE AND STABILITY OF MAGNETIC TOWER JETS  

SciTech Connect

Modern theoretical models of astrophysical jets combine accretion, rotation, and magnetic fields to launch and collimate supersonic flows from a central source. Near the source, magnetic field strengths must be large enough to collimate the jet requiring that the Poynting flux exceeds the kinetic energy flux. The extent to which the Poynting flux dominates kinetic energy flux at large distances from the engine distinguishes two classes of models. In magneto-centrifugal launch models, magnetic fields dominate only at scales {approx}< 100 engine radii, after which the jets become hydrodynamically dominated (HD). By contrast, in Poynting flux dominated (PFD) magnetic tower models, the field dominates even out to much larger scales. To compare the large distance propagation differences of these two paradigms, we perform three-dimensional ideal magnetohydrodynamic adaptive mesh refinement simulations of both HD and PFD stellar jets formed via the same energy flux. We also compare how thermal energy losses and rotation of the jet base affects the stability in these jets. For the conditions described, we show that PFD and HD exhibit observationally distinguishable features: PFD jets are lighter, slower, and less stable than HD jets. Unlike HD jets, PFD jets develop current-driven instabilities that are exacerbated as cooling and rotation increase, resulting in jets that are clumpier than those in the HD limit. Our PFD jet simulations also resemble the magnetic towers that have been recently created in laboratory astrophysical jet experiments.

Huarte-Espinosa, M.; Frank, A.; Blackman, E. G. [Department of Physics and Astronomy, University of Rochester, 600 Wilson Boulevard, Rochester, NY 14627-0171 (United States); Ciardi, A. [LERMA, Universite Pierre et Marie Curie, Observatoire de Paris, F-92195 Meudon (France); Hartigan, P. [Department of Physics and Astronomy, Rice University, 6100 S. Main, Houston, TX 77521-1892 (United States); Lebedev, S. V.; Chittenden, J. P. [Blackett Laboratory, Imperial College London, SW7 2BW London (United Kingdom)

2012-09-20T23:59:59.000Z

364

Hydrocracking is an important source of diesel and jet fuel ...  

U.S. Energy Information Administration (EIA)

Hydrogen is also used to control the temperature of the reactor—it is fed into the reactor at different points. This keeps the reactor temperature from cooling ...

365

Spinning fluids reactor  

SciTech Connect

A spinning fluids reactor, includes a reactor body (24) having a circular cross-section and a fluid contactor screen (26) within the reactor body (24). The fluid contactor screen (26) having a plurality of apertures and a circular cross-section concentric with the reactor body (24) for a length thus forming an inner volume (28) bound by the fluid contactor screen (26) and an outer volume (30) bound by the reactor body (24) and the fluid contactor screen (26). A primary inlet (20) can be operatively connected to the reactor body (24) and can be configured to produce flow-through first spinning flow of a first fluid within the inner volume (28). A secondary inlet (22) can similarly be operatively connected to the reactor body (24) and can be configured to produce a second flow of a second fluid within the outer volume (30) which is optionally spinning.

Miller, Jan D; Hupka, Jan; Aranowski, Robert

2012-11-20T23:59:59.000Z

366

Determining Reactor Neutrino Flux  

E-Print Network (OSTI)

Flux is an important source of uncertainties for a reactor neutrino experiment. It is determined from thermal power measurements, reactor core simulation, and knowledge of neutrino spectra of fuel isotopes. Past reactor neutrino experiments have determined the flux to (2-3)% precision. Precision measurements of mixing angle $\\theta_{13}$ by reactor neutrino experiments in the coming years will use near-far detector configurations. Most uncertainties from reactor will be canceled out. Understanding of the correlation of uncertainties is required for $\\theta_{13}$ experiments. Precise determination of reactor neutrino flux will also improve the sensitivity of the non-proliferation monitoring and future reactor experiments. We will discuss the flux calculation and recent progresses.

Cao, Jun

2011-01-01T23:59:59.000Z

367

Reactor water cleanup system  

DOE Patents (OSTI)

A reactor water cleanup system includes a reactor pressure vessel containing a reactor core submerged in reactor water. First and second parallel cleanup trains are provided for extracting portions of the reactor water from the pressure vessel, cleaning the extracted water, and returning the cleaned water to the pressure vessel. Each of the cleanup trains includes a heat exchanger for cooling the reactor water, and a cleaner for cleaning the cooled reactor water. A return line is disposed between the cleaner and the pressure vessel for channeling the cleaned water thereto in a first mode of operation. A portion of the cooled water is bypassed around the cleaner during a second mode of operation and returned through the pressure vessel for shutdown cooling.

Gluntz, Douglas M. (San Jose, CA); Taft, William E. (Los Gatos, CA)

1994-01-01T23:59:59.000Z

368

Determining Reactor Neutrino Flux  

E-Print Network (OSTI)

Flux is an important source of uncertainties for a reactor neutrino experiment. It is determined from thermal power measurements, reactor core simulation, and knowledge of neutrino spectra of fuel isotopes. Past reactor neutrino experiments have determined the flux to (2-3)% precision. Precision measurements of mixing angle $\\theta_{13}$ by reactor neutrino experiments in the coming years will use near-far detector configurations. Most uncertainties from reactor will be canceled out. Understanding of the correlation of uncertainties is required for $\\theta_{13}$ experiments. Precise determination of reactor neutrino flux will also improve the sensitivity of the non-proliferation monitoring and future reactor experiments. We will discuss the flux calculation and recent progresses.

Jun Cao

2011-01-12T23:59:59.000Z

369

Fission reactors and materials  

SciTech Connect

The American-designed boiling water reactor and pressurized water reactor dominate the designs currently in use and under construction worldwide. As in all energy systems, materials problems have appeared during service; these include stress-corrosion of stainless steel pipes and heat exchangers and questions regarding crack behavior in pressure vessels. To obtain the maximum potential energy from our limited uranium supplies is is essential to develop the fast breeder reactor. The materials in these reactors are subjected to higher temperatures and neutron fluxes but lower pressures than in the water reactors. The performance required of the fuel elements is more arduous in the breeder than in water reactors. Extensive materials programs are in progress in test reactors and in large test rigs to ensure that materials will be available to meet these conditions.

Frost, B.R.T.

1981-12-01T23:59:59.000Z

370

High energy emission from galactic jets  

E-Print Network (OSTI)

In this chapter we review some aspects of X-ray binaries, particularly those presenting steady jets, i.e. microquasars. Because of their proximity and similarities with active galactic nuclei (AGN), galactic jet sources are unique laboratories to test astrophysical theories of a universal scope. Due to recent observational progress made with the new generation of gamma-ray imaging atmospheric Cherenkov telescopes and in view of the upcoming km3-size neutrino detectors, we focus especially on the possible high-energy gamma radiation and neutrino emission. In connection with this, we also comment about astrophysical jets present in young stellar objects, and we briefly discuss similarities and differences with extragalactic AGN and gamma-ray bursters.

H. R. Christiansen

2013-06-07T23:59:59.000Z

371

The Dynamical Relationship between Subtropical and Eddy-Driven Jets  

Science Conference Proceedings (OSTI)

This study examines the impact of a subtropical jet on the development of baroclinic waves and polar-front jets with an idealized multilevel primitive equation model. Linear stability analysis and initial-value approaches suggest that baroclinic ...

Sukyoung Lee; Hyun-kyung Kim

2003-06-01T23:59:59.000Z

372

Jet physics from static charges in AdS space  

E-Print Network (OSTI)

Soft interactions with high-energy jets are explored in radial coordinates which exploit the approximately conformal behavior of perturbative gauge theories. In these coordinates, the jets, approximated by Wilson lines, ...

Stewart, Iain

373

Formation of Jets and Equatorial Superrotation on Jupiter  

Science Conference Proceedings (OSTI)

The zonal flow in Jupiter’s upper troposphere is organized into alternating retrograde and prograde jets, with a prograde (superrotating) jet at the equator. Existing models posit as the driver of the flow either differential radiative heating of ...

Tapio Schneider; Junjun Liu

2009-03-01T23:59:59.000Z

374

Recirculation Gyres Forced by a Beta-Plane Jet  

Science Conference Proceedings (OSTI)

A numerical model, with quasigeostrophic and barotropic dynamics, is used to study the forcing of mean flows by an unstable jet. The initially zonal jet has specified shape and transport at the western inflow boundary and is sufficiently intense ...

Steven R. Jayne; Nelson G. Hogg; Paola Malanotte-Rizzoli

1996-04-01T23:59:59.000Z

375

Jet Jumping: Low-Frequency Variability in the Southern Ocean  

Science Conference Proceedings (OSTI)

The authors study intrinsic variability in the position of jets in a ?-plane channel ocean with simple topography using a quasigeostrophic numerical model. This study links the variability in jet position with abyssal anticyclones that form as a ...

Christopher C. Chapman; Andrew McC. Hogg

2013-05-01T23:59:59.000Z

376

Optimized Parameters for a Mercury Jet Target  

Science Conference Proceedings (OSTI)

A study of target parameters for a high-power, liquid mercury jet target system for a neutrino factory or muon collider is presented. Using the MARS code, we simulate particle production initiated by incoming protons with kinetic energies between 2 and 100 GeV. For each proton beam energy, we maximize production by varying the geometric parameters of the target: the mercury jet radius, the incoming proton beam angle, and the crossing angle between the mercury jet and the proton beam. The number of muons surviving through an ionization cooling channel is determined as a function of the proton beam energy. We optimize the mercury jet target parameters: the mercury jet radius, the incoming proton beam angle and the crossing angle between the mercury jet and the proton beam for each proton beam energy. The optimized target radius varies from about 0.4 cm to 0.6 cm as the proton beam energy increases. The optimized beam angle varies from 75 mrad to 120 mrad. The optimized crossing angle is near 20 mrad for energies above 5 GeV. These values differ from earlier choices of 67 mrad for the beam angle and 33 mrad for the crossing angle. These new choices for the beam parameters increase the meson production by about 20% compared to the earlier parameters. Our study demonstrates that the maximum meson production efficiency per unit proton beam power occurs when the proton kinetic energy is in the range of 5-15 GeV. Finally, the dependence on energy of the number of muons at the end of the cooling channel is nearly identical to the dependence on energy of the meson production 50 m from the target. This demonstrates that the target parameters can be optimized without the additional step of running the distribution through a code such as ICOOL that simulates the bunching, phase rotation, and cooling.

Ding, X.; Kirk, H.

2010-12-01T23:59:59.000Z

377

Gamma-Ray Bursts: Jets and Energetics  

E-Print Network (OSTI)

The relativistic outflows from gamma-ray bursts are now thought to be narrowly collimated into jets. After correcting for this jet geometry there is a remarkable constancy of both the energy radiated by the burst and the kinetic energy carried by the outflow. Gamma-ray bursts are still the most luminous explosions in the Universe, but they release energies that are comparable to supernovae. The diversity of cosmic explosions appears to be governed by the fraction of energy that is coupled to ultra-relativistic ejecta.

D. A. Frail

2003-11-12T23:59:59.000Z

378

Gravity waves from vortex dipoles and jets  

E-Print Network (OSTI)

The dissertation first investigates gravity wave generation and propagation from jets within idealized vortex dipoles using a nonhydrostatic mesoscale model. Several initially balanced and localized jets induced by vortex dipoles are examined here. Within these dipoles, inertia-gravity waves with intrinsic frequencies 1-2 times the Coriolis parameter are simulated in the jet exit region. The ray tracing analysis reveals strong variation of wave characteristics along ray paths. The dependence of wave amplitude on the Rossby number is examined through experiments in which the two vortices are initially separated by a large distance but subsequently approach each other and form a vortex dipole with an associated amplifying localized jet. The amplitude of stationary gravity waves in the simulations with a 90-km grid spacing increases nearly linearly with the square of the Rossby number but significantly more rapidly when smaller grid spacing is used. To further address the source mechanism of the gravity waves within the vortex dipole, a linear numerical framework is developed based on the framework proposed by Plougonven and Zhang (2007). Using the nonlinearly balanced fields as the basic state and driven by three types of large scale forcing, the vorticity, divergence and thermodynamic forcing, this linear model is utilized to obtain linear wave responses. The wave packets in the linear responses compare reasonably well with the MM5 simulated gravity waves. It is suggested that the vorticity forcing is the leading contribution to both gravity waves in the jet exit region and the ascent/descent feature in the jet core. This linear model is also adopted to study inertia-gravity waves in the vicinity of a baroclinic jet during the life cycle of an idealized baroclinic wave. It is found that the thermodynamic forcing and the vorticity forcing are equally important to the gravity waves in the low stratosphere, but the divergence forcing is again playing a lesser role. Two groups of wave packets are present in the linear responses; their sources appear to locate either near the surface front or near the middle/upper tropospheric jet.

Wang, Shuguang

2008-08-01T23:59:59.000Z

379

Centrifugally driven electrostatic instability in extragalactic jets  

SciTech Connect

The stability problem of the rotation-induced electrostatic wave in extragalactic jets is presented. Solving a set of equations describing dynamics of a relativistic plasma flow of active galactic nuclei (AGN) jets, an expression of the instability rate has been derived and analyzed for typical values of AGNs. The growth rate was studied versus the wavelength and the inclination angle and it has been found that the instability process is very efficient with respect to the accretion disk evolution, indicating high efficiency of the instability.

Osmanov, Z. [Georgian National Astrophysical Observatory, Kazbegi ave. 2a, Tbilisi 0160 (Georgia)

2008-03-15T23:59:59.000Z

380

The Cambridge Jet algorithm: features and applications  

E-Print Network (OSTI)

Jet clustering algorithms are widely used to analyse hadronic events in high energy collisions. Recently a new clustering method, known as `Cambridge', has been introduced. In this article we present an algorithm to determine the transition values of y_cut for this clustering scheme, which allows to resolve any event to a definite number of jets in the final state. We discuss some particularities of the Cambridge clustering method and compare its performance to the Durham clustering scheme for Monte Carlo generated e+e- annihilation events.

Stan Bentvelsen; Irmtraud Meyer

1998-03-12T23:59:59.000Z

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


381

High pressure water jet mining machine  

DOE Patents (OSTI)

A high pressure water jet mining machine for the longwall mining of coal is described. The machine is generally in the shape of a plowshare and is advanced in the direction in which the coal is cut. The machine has mounted thereon a plurality of nozzle modules each containing a high pressure water jet nozzle disposed to oscillate in a particular plane. The nozzle modules are oriented to cut in vertical and horizontal planes on the leading edge of the machine and the coal so cut is cleaved off by the wedge-shaped body.

Barker, Clark R. (Rolla, MO)

1981-05-05T23:59:59.000Z

382

Enhancement of wall jet transport properties  

DOE Patents (OSTI)

By enhancing the natural instabilities in the boundary layer and in the free shear layer of a wall jet, the boundary is minimized thereby increasing the transport of heat and mass. Enhancing the natural instabilities is accomplished by pulsing the flow of air that creates the wall jet. Such pulsing of the flow of air can be accomplished by sequentially occluding and opening a duct that confines and directs the flow of air, such as by rotating a disk on an axis transverse to the flow of air in the duct.

Claunch, Scott D. (Broomfield, CO); Farrington, Robert B. (Golden, CO)

1997-01-01T23:59:59.000Z

383

Jets and the hadronic final state at HERA  

E-Print Network (OSTI)

Recent results on jets and the hadronic final state from the HERA collaborations H1 and ZEUS are reviewed.

T. Schoerner-Sadenius

2004-10-07T23:59:59.000Z

384

Photon - Jet Correlations and Constraints on Fragmentation Functions  

E-Print Network (OSTI)

We study the production of a large-pT photon in association with a jet in proton-proton collisions. We examine the sensitivity of the jet rapidity distribution to the gluon distribution function in the proton. We then assess the sensitivity of various photon + jet correlation observables to the photon fragmentation functions. We argue that RHIC data on photon-jet correlations can be used to constrain the photon fragmentation functions in a region which was barely accessible in LEP experiments.

Z. Belghobsi; M. Fontannaz; J. -Ph. Guillet; G. Heinrich; E. Pilon; M. Werlen

2009-03-27T23:59:59.000Z

385

Gauge/gravity duality and jets in strongly coupled plasma  

E-Print Network (OSTI)

We discuss jets in strongly coupled N = 4 supersymmetric Yang-Mills plasma and their dual gravitational description.

Chesler, Paul M

2009-01-01T23:59:59.000Z

386

Gauge/gravity duality and jets in strongly coupled plasma  

E-Print Network (OSTI)

We discuss jets in strongly coupled N = 4 supersymmetric Yang-Mills plasma and their dual gravitational description.

Paul M. Chesler

2009-07-26T23:59:59.000Z

387

Michigan Refinery Catalytic Hydrotreating, Kerosene/Jet Fuel ...  

U.S. Energy Information Administration (EIA)

Cat. Hydro.. Kerosene/Jet Fuel Downstream Charge Capacity (B/SD) Michigan Downstream Charge Capacity of Operable Petroleum Refineries ...

388

Puerto Rico Refinery Catalytic Hydrotreating, Kerosene/Jet Fuel ...  

U.S. Energy Information Administration (EIA)

Puerto Rico Refinery Catalytic Hydrotreating, Kerosene/Jet Fuel Downstream Charge Capacity as of January 1 (Barrels per Stream Day)

389

On the Counter-jet Emission in GRB Afterglows  

Science Conference Proceedings (OSTI)

We investigate the dynamical evolution of double-sided jets and present detailed numerical studies on the emission from the receding jet of gamma-ray bursts. It is found that the receding jet emission is generally very weak and only manifests as a plateau in the late time radio afterglow light curves. Additionally, we find that the effect of synchrotron self-absorption can influence the peak time of the receding jet emission significantly.

Wang Xin; Huang, Y. F. [Department of Astronomy, Nanjing University, Nanjing 210093 (China)

2010-10-15T23:59:59.000Z

390

Enhanced Generic Phase-field Model of Irradiation Materials: Fission Gas Bubble Growth Kinetics in Polycrystalline UO2  

SciTech Connect

Experiments show that inter-granular and intra-granular gas bubbles have different growth kinetics which results in heterogeneous gas bubble microstructures in irradiated nuclear fuels. A science-based model predicting the heterogeneous microstructure evolution kinetics is desired, which enables one to study the effect of thermodynamic and kinetic properties of the system on gas bubble microstructure evolution kinetics and morphology, improve the understanding of the formation mechanisms of heterogeneous gas bubble microstructure, and provide the microstructure to macroscale approaches to study their impact on thermo-mechanical properties such as thermo-conductivity, gas release, volume swelling, and cracking. In our previous report 'Mesoscale Benchmark Demonstration, Problem 1: Mesoscale Simulations of Intra-granular Fission Gas Bubbles in UO2 under Post-irradiation Thermal Annealing', we developed a phase-field model to simulate the intra-granular gas bubble evolution in a single crystal during post-irradiation thermal annealing. In this work, we enhanced the model by incorporating thermodynamic and kinetic properties at grain boundaries, which can be obtained from atomistic simulations, to simulate fission gas bubble growth kinetics in polycrystalline UO2 fuels. The model takes into account of gas atom and vacancy diffusion, vacancy trapping and emission at defects, gas atom absorption and resolution at gas bubbles, internal pressure in gas bubbles, elastic interaction between defects and gas bubbles, and the difference of thermodynamic and kinetic properties in matrix and grain boundaries. We applied the model to simulate gas atom segregation at grain boundaries and the effect of interfacial energy and gas mobility on gas bubble morphology and growth kinetics in a bi-crystal UO2 during post-irradiation thermal annealing. The preliminary results demonstrate that the model can produce the equilibrium thermodynamic properties and the morphology of gas bubbles at grain boundaries for given grain boundary properties. More validation of the model capability in polycrystalline is underway.

Li, Yulan; Hu, Shenyang Y.; Montgomery, Robert O.; Gao, Fei; Sun, Xin

2012-05-30T23:59:59.000Z

391

Atomistic model of helium bubbles in gallium-stabilized plutonium alloys  

Science Conference Proceedings (OSTI)

The varying thermodynamic stability of gallium- (Ga-) stabilized plutonium (Pu) alloys with temperature affords a unique setting for the development of self-irradiation damage. Here, fundamental characteristics of helium (He) bubbles in these alloys with respect to temperature, gallium concentration, and He-to-vacancy ratio are modeled at the atomistic level with a modified embedded atom potential that takes account of this varying stability. Aside from the bubbles themselves, the surrounding matrix material is single-crystal metal or alloy. As a function of temperature, with a 2:1 He-to-vacancy ratio in a 5-at. % Ga fcc lattice, a 1.25-nm bubble is very stable up to about 1000 K. At 1000 K, the bubble distorts the surrounding lattice and precipitates a liquid zone, as is consistent with the phase diagram for the model material. Between 300 and 500 K, this same bubble relaxes slightly through interstitial emission. At 300 K, with a 2:1 He-to-vacancy ratio in a 2.5-at. % Ga fcc lattice, the Ga stabilization is less effective in the model to the point where the bubble distorts the local lattice and expands significantly. Similarly, at 300 K, if the He-to-vacancy ratio is increased to 3:1, there is significant local lattice distortion, as well as ejection of some He atoms into the lattice. The formation of new bubbles is not observed, because those events take place on a longer time scale than can be simulated with the present approach.

Valone, S. M.; Baskes, M. I. [Materials Science and Technology Division and Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Martin, R. L. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2006-06-01T23:59:59.000Z

392

Natural Fueling of a Tokamak Fusion Reactor  

E-Print Network (OSTI)

A natural fueling mechanism that helps to maintain the main core deuterium and tritium (DT) density profiles in a tokamak fusion reactor is discussed. In H-mode plasmas dominated by ion- temperature gradient (ITG) driven turbulence, cold DT ions near the edge will naturally pinch radially inward towards the core. This mechanism is due to the quasi-neutral heat flux dominated nature of ITG turbulence and still applies when trapped and passing kinetic electron effects are included. Fueling using shallow pellet injection or supersonic gas jets is augmented by an inward pinch of could DT fuel. The natural fueling mechanism is demonstrated using the three-dimensional toroidal electromagnetic gyrokinetic turbulence code GEM and is analyzed using quasilinear theory. Profiles similar to those used for conservative ITER transport modeling that have a completely flat density profile are examined and it is found that natural fueling actually reduces the linear growth rates and energy transport.

Wan, Weigang; Chen, Yang; Perkins, Francis W

2009-01-01T23:59:59.000Z

393

Jet impact on a soap film Geoffroy Kirstetter, Christophe Raufaste,  

E-Print Network (OSTI)

of the micro-jet or con- versely on its destabilization through the control of the liquid jet atomization, such as impacts, have recently raised some interest and uses for sound absorp- tion or bomb explosion safety [15 can be used to guide and control the jet direction. In the second one, a new class of flow is reported

Paris-Sud XI, Université de

394

Structure and Spacing of Jets in Barotropic Turbulence  

Science Conference Proceedings (OSTI)

Turbulent flows are often observed to be organized into large-spatial-scale jets such as the familiar zonal jets in the upper levels of the Jovian atmosphere. These relatively steady large-scale jets are not forced coherently but are maintained ...

Brian F. Farrell; Petros J. Ioannou

2007-10-01T23:59:59.000Z

395

Jet pump feeds corrosion inhibitor in Russian waterflood  

SciTech Connect

The Russian company Orenburgneft JSC tested a proportioning jet pump for injecting corrosion inhibitor into the water injection system at its Tananykskoye waterflood. The jet pump has no moving parts and, therefore, provides an hermetic system with zero emissions of pumped and working fluid. This pump reduces weight, dimensions, and costs compared to mechanical pumps. The paper describes jet pumping and the pump design.

Yuden, I.S. [JKX Oil and Gas, Guildford (United Kingdom); Sazanov, Y.A.; Yeliseev, V.N.; Malov, B.A. [Orenburgneft JSC, Moscow (Russian Federation)

1997-01-27T23:59:59.000Z

396

Studying Z/gamma*+Jet Production  

SciTech Connect

The production of jets in association with a Z/{gamma}* boson is an example of an important class of processes at hadron colliders, namely vector boson + jet (V + jet) production. Comparisons of measurements of this class of processes with theory predictions constitute an important, fundamental test of the Standard Model of particle physics, and of the theory of QCD in particular. While having a smaller cross section than other V +jet processes, Z/{gamma}*({yields} e{sup +}e{sup -}) + jets production, with Z/{gamma}* {yields} e{sup +}e{sup -}/{mu}{sup +}{mu}{sup -}, has a distinct experimental signature allowing for measurements characterized by low backgrounds and a direct, precise measurement of the properties of the decay products of the Z/{gamma}* boson. In this thesis, several new measurements of the properties of jets produced in association with a Z/{gamma}* boson in p{bar p} collisions at {radical}s = 1.96 TeV are presented. The cross section for Z/{gamma}*({yields} e{sup +}e{sup -}) + N jet production (N {le} 3) is measured, differential in the transverse momentum of the Nth jet in the event, normalized to the inclusive Z/{gamma}* cross section. Also, the cross section for Z/{gamma}*({yields} e{sup +}e{sup -}) + N jets (N {ge} 1) is measured, differential in the difference in azimuthal angle between the di-electron system and any jet in the event, normalized to unity. The data used in the measurements were collected by the D0 experiment located at the Tevatron Collider of the Fermi National Accelerator Laboratory and correspond to an integrated luminosity of 1.04 fb{sup -1}. The measured jet transverse momentum spectra are compared with the predictions of perturbative calculations at the next-to-leading order in the strong coupling constant. Given the low sensitivity of the calculations to model parameters, these comparisons represent a stringent test of perturbative QCD. One of the main goals currently being pursued in particle physics is the discovery of the only particle predicted by the Standard Model which has so far no been detected experimentally, namely the Higgs boson. It is assumed that the ATLAS and CMS experiments located at the Large Hadron Collider (LHC), a proton-proton collider at {radical}s = 14 TeV, will be able to detect the Higgs boson, or rule out its existence, within the next few years. The collisions delivered by the LHC will also be used to perform a long range of searches for other new particles, for instance particles predicted by models based on the principle of supersymmetry. The associated production of vector bosons with jets has relatively large production rates at the LHC and can produce a long list of different final states which can include charged leptons, missing transverse energy, as well as light- and heavy-flavour jets. This makes V + jet production a major source of background events to many searches for new particles. Most techniques used for estimating the expected number of background events to searches rely on passing the stable final-state particles of simulated hadron collisions generated using a so-called event generator code, through a simulation of the experimental detector system. The development of event generators which are capable of reliably predicting the properties of jets produced in association with a core process, e.g. the production of a vector boson, has been the subject of a large amount of research activity during the last ten years. These efforts have led to the appearance of the CKKW and MLM algorithms which are implemented in several event generators, among them SHERPA and ALPGEN + PYTHIA. The large data sample collected by the D0 experiment during Run II offers an excellent opportunity for validating these new event generators against experimental measurements of V + jet production. As argued above, the Z/{gamma}*({yields} e{sup +}e{sup -}) + jets process offers the combination of a clean experimental signature and large production rates, making it the process of choice for these studies.

Nilsen, Henrik Wold; /Freiburg U.

2009-07-01T23:59:59.000Z

397

A BUBBLING NEARBY MOLECULAR CLOUD: COMPLETE SHELLS IN PERSEUS  

SciTech Connect

We present a study of the shells (and bubbles) in the Perseus molecular cloud using the COMPLETE survey large-scale {sup 12}CO(1-0) and {sup 13}CO(1-0) maps. The 12 shells reported here are spread throughout most of the Perseus cloud and have circular or arc-like morphologies with a range in radius of about 0.1-3 pc. Most of them have not been detected before most likely because maps of the region lacked the coverage and resolution needed to distinguish them. The majority of the shells are coincident with infrared nebulosity of similar shape and have a candidate powering source near the center. We suggest that they are formed by the interaction of spherical or very wide angle winds powered by young stars inside or near the Perseus molecular cloud-a cloud that is commonly considered to be forming mostly low-mass stars. Two of the 12 shells are powered by high-mass stars close to the cloud, while the others appear to be powered by low- or intermediate-mass stars in the cloud. We argue that winds with a mass loss rate of about 10{sup -8} to 10{sup -6} M{sub Sun} yr{sup -1} are required to produce the observed shells. Our estimates indicate that the energy input rate from these stellar winds is similar to the turbulence dissipation rate. We conclude that in Perseus the total energy input from both collimated protostellar outflows and powerful spherical winds from young stars is sufficient to maintain the turbulence in the molecular cloud. Large-scale molecular line and IR continuum maps of a sample of clouds will help determine the frequency of this phenomenon in other star-forming regions.

Arce, Hector G. [Department of Astronomy, Yale University, New Haven, CT 06520 (United States); Borkin, Michelle A. [School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138 (United States); Goodman, Alyssa A. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Pineda, Jaime E. [ESO, 85748 Garching (Germany); Beaumont, Christopher N., E-mail: hector.arce@yale.edu, E-mail: michelle_borkin@harvard.edu, E-mail: agoodman@cfa.harvard.edu, E-mail: jaime.pineda@manchester.ac.uk, E-mail: beaumont@ifa.hawaii.edu, E-mail: cbeaumont@cfa.harvard.edu [Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)

2011-12-01T23:59:59.000Z

398

A Parametric Investigation of Gas Bubble Growth and Pinch-Off Dynamics from Capillary-Tube Orifices in Liquid Pools.  

E-Print Network (OSTI)

??The air-bubble dynamics phenomena in adiabatic liquid pools has been studied so as to present a better understanding of the parameters which that govern the… (more)

Kalaikadal, Deepak Saagar

2012-01-01T23:59:59.000Z

399

Generation -IV Reactor Concepts  

NLE Websites -- All DOE Office Websites (Extended Search)

Generation-IV Reactor Concepts Generation-IV Reactor Concepts Thomas H. Fanning Argonne National Laboratory 9700 South Cass Avenue Argonne, Illinois 60439, USA The Generation-IV International Forum (GIF) is a multi-national research and development (R&D) collaboration. The GIF pursues the development of advanced, next generation reactor technology with goals to improve: a) sustainability (effective fuel utilization and minimization of waste) b) economics (competitiveness with respect to other energy sources) c) safety and reliability (e.g., no need for offsite emergency response), and d) proliferation resistance and physical protection The GIF Technology Roadmap exercise selected six generic systems for further study: the Gas- cooled Fast Reactor (GFR), the Lead-cooled Fast Reactor (LFR), the Molten Salt Reactor (MSR),

400

HORIZONTAL BOILING REACTOR SYSTEM  

DOE Patents (OSTI)

Reactors of the boiling water type are described wherein water serves both as the moderator and coolant. The reactor system consists essentially of a horizontal pressure vessel divided into two compartments by a weir, a thermal neutronic reactor core having vertical coolant passages and designed to use water as a moderator-coolant posltioned in one compartment, means for removing live steam from the other compartment and means for conveying feed-water and water from the steam compartment to the reactor compartment. The system further includes auxiliary apparatus to utilize the steam for driving a turbine and returning the condensate to the feed-water inlet of the reactor. The entire system is designed so that the reactor is self-regulating and has self-limiting power and self-limiting pressure features.

Treshow, M.

1958-11-18T23:59:59.000Z

Note: This page contains sample records for the topic "jet bubbling reactor" 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

Internal Wave Interactions with Equatorial Deep Jets. Part II: Acceleration of the Jets  

Science Conference Proceedings (OSTI)

What drives the equatorial deep jets is a puzzle because of their isolation from surface forcing by the intervening main pycnocline and the Equatorial Undercurrent, and from lateral boundaries by distances of tens of thousands of kilometers. It ...

Joanna E. Muench; Eric Kunze

2000-08-01T23:59:59.000Z

402

The JET2000 Project: Aircraft Observations of the African Easterly Jet and African Easterly Waves  

Science Conference Proceedings (OSTI)

Scientific background and motivation for the JET2000 aircraft observing campaign that took place in West Africa during the last week of August 2000 are presented. The Met Research Flight C130 aircraft made two flights along the African easterly ...

C. D. Thorncroft; D. J. Parker; R. R. Burton; M. Diop; J. H. Ayers; H. Barjat; S. Devereau; A. Diongue; R. Dumelow; D. R. Kindred; N. M. Price; M. Saloum; C. M. Tayor; A. M. Tompkins

2003-03-01T23:59:59.000Z

403

Three dimensional analysis of turbulent steam jets in enclosed structures : a CFD approach.  

SciTech Connect

This paper compares the three-dimensional numerical simulation with the experimental data of a steam blowdown event in a light water reactor containment building. The temperature and pressure data of a steam blowdown event was measured at the Purdue University Multi-Dimensional Integrated Test Assembly (PUMA), a scaled model of the General Electric simplified Boiling Water Reactor. A three step approach was used to analyze the steam jet behavior. First, a 1-Dimensional, system level RELAP5/Mod3.2 model of the steam blowdown event was created and the results used to set the initial conditions for the PUMA blowdown experiments. Second, 2-Dimensional CFD models of the discharged steam jets were computed using PHOENICS, a commercially available CFD package. Finally, 3-Dimensional model of the PUMA drywell was created with the boundary conditions based on experimental measurements. The results of the 1-D and 2-D models were reported in the previous meeting. This paper discusses in detail the formulation and the results of the 3-Dimensional PHOENICS model of the PUMA drywell. It is found that the 3-D CFD solutions compared extremely well with the measured data.

Ishii, M.; NguyenLe, Q.

1999-04-20T23:59:59.000Z

404

THERMAL NEUTRONIC REACTOR  

DOE Patents (OSTI)

A novel thermal reactor was designed in which a first reflector formed from a high atomic weight, nonmoderating material is disposed immediately adjacent to the reactor core. A second reflector composed of a moderating material is disposed outwardly of the first reflector. The advantage of this novel reflector arrangement is that the first reflector provides a high slow neutron flux in the second reflector, where irradiation experiments may be conducted with a small effect on reactor reactivity.

Spinrad, B.I.

1960-01-12T23:59:59.000Z

405

NUCLEAR REACTORS AND EARTHQUAKES  

SciTech Connect

A book is presented which supplies pertinent seismological information to engineers in the nuclear reactor field. Data are presented on the occurrence, intensity, and wave shapes. Techniques are described for evaluating the response of structures to such events. Certain reactor types and their modes of operation are described briefly. Various protection systems are considered. Earthquake experience in industrial and reactor plants is described. (D.L.C.)

1961-01-01T23:59:59.000Z

406

Gluon Polarization and Jet Production at STAR  

Science Conference Proceedings (OSTI)

I will discuss the most recent measurements of the inclusive jet longitudinal spin asymmetry A LL in polarized proton?proton collisions. STAR collected its largest data sample thus far 4.7? pb ?1 of integrated luminosity at an average beam polarization of ?57%

Pibero Djawotho; the STAR Collaboration

2009-01-01T23:59:59.000Z

407

Online b-jets tagging at CDF  

Science Conference Proceedings (OSTI)

We propose a method to identify b-quark jets at trigger level which exploits recently increased CDF trigger system capabilities. b-quark jets identification is of central interest for the CDF high-P{sub T} physics program, and the possibility to select online b-jets enriched samples can extend the physics reaches especially for light Higgs boson searches where the H {yields} b{bar b} decay mode is dominant. Exploiting new trigger primitives provided by two recent trigger upgrades, the Level2 XFT stereo tracking and the improved Level2 cluster-finder, in conjunction with the existing Silicon Vertex Tracker (SVT), we design an online trigger algorithm aimed at selecting good purity b-jets samples useful for many physics measurements, the most important being inclusive H {yields} b{bar b} searches. We discuss the performances of the proposed b-tagging algorithm which must guarantee reasonable trigger rates at luminosity greater than 2 x 10{sup 32} cm{sup -2}s{sup -1} and provide high efficiency on H {yields} b{bar b} events.

Casarsa, M.; /Fermilab; Ristori, L.; /INFN, Pisa; Amerio, S.; Lucchesi, D.; Pagan Griso, S.; /INFN, Padua; Torre, S.T.; /Frascati; Cortiana, G.; /Padua U., Astron. Dept.

2007-04-01T23:59:59.000Z

408

HOT ELECTROMAGNETIC OUTFLOWS. II. JET BREAKOUT  

Science Conference Proceedings (OSTI)

We consider the interaction between radiation, matter, and a magnetic field in a compact, relativistic jet. The entrained matter accelerates outward as the jet breaks out of a star or other confining medium. In some circumstances, such as gamma-ray bursts (GRBs), the magnetization of the jet is greatly reduced by an advected radiation field while the jet is optically thick to scattering. Where magnetic flux surfaces diverge rapidly, a strong outward Lorentz force develops and radiation and matter begin to decouple. The increase in magnetization is coupled to a rapid growth in Lorentz factor. We take two approaches to this problem. The first examines the flow outside the fast magnetosonic critical surface, and calculates the flow speed and the angular distribution of the radiation field over a range of scattering depths. The second considers the flow structure on both sides of the critical surface in the optically thin regime, using a relaxation method. In both approaches, we find how the terminal Lorentz factor and radial profile of the outflow depend on the radiation intensity and optical depth at breakout. The effect of bulk Compton scattering on the radiation spectrum is calculated by a Monte Carlo method, while neglecting the effects of internal dissipation. The peak of the scattered spectrum sits near the seed peak if radiation pressure dominates the acceleration, but is pushed to a higher frequency if the Lorentz force dominates. The unscattered seed radiation can form a distinct, low-frequency component of the spectrum, especially if the magnetic Poynting flux dominates.

Russo, Matthew [Department of Physics, University of Toronto, 60 St. George Street, Toronto, ON M5S 1A7 (Canada); Thompson, Christopher [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, Toronto, ON M5S 3H8 (Canada)

2013-08-20T23:59:59.000Z

409

Pressurized fluidized bed reactor  

DOE Patents (OSTI)

A pressurized fluid bed reactor power plant includes a fluidized bed reactor contained within a pressure vessel with a pressurized gas volume between the reactor and the vessel. A first conduit supplies primary gas from the gas volume to the reactor, passing outside the pressure vessel and then returning through the pressure vessel to the reactor, and pressurized gas is supplied from a compressor through a second conduit to the gas volume. A third conduit, comprising a hot gas discharge, carries gases from the reactor, through a filter, and ultimately to a turbine. During normal operation of the plant, pressurized gas is withdrawn from the gas volume through the first conduit and introduced into the reactor at a substantially continuously controlled rate as the primary gas to the reactor. In response to an operational disturbance of the plant, the flow of gas in the first, second, and third conduits is terminated, and thereafter the pressure in the gas volume and in the reactor is substantially simultaneously reduced by opening pressure relief valves in the first and third conduits, and optionally by passing air directly from the second conduit to the turbine.

Isaksson, Juhani (Karhula, FI)

1996-01-01T23:59:59.000Z

410

Pressurized fluidized bed reactor  

DOE Patents (OSTI)

A pressurized fluid bed reactor power plant includes a fluidized bed reactor contained within a pressure vessel with a pressurized gas volume between the reactor and the vessel. A first conduit supplies primary gas from the gas volume to the reactor, passing outside the pressure vessel and then returning through the pressure vessel to the reactor, and pressurized gas is supplied from a compressor through a second conduit to the gas volume. A third conduit, comprising a hot gas discharge, carries gases from the reactor, through a filter, and ultimately to a turbine. During normal operation of the plant, pressurized gas is withdrawn from the gas volume through the first conduit and introduced into the reactor at a substantially continuously controlled rate as the primary gas to the reactor. In response to an operational disturbance of the plant, the flow of gas in the first, second, and third conduits is terminated, and thereafter the pressure in the gas volume and in the reactor is substantially simultaneously reduced by opening pressure relief valves in the first and third conduits, and optionally by passing air directly from the second conduit to the turbine. 1 fig.

Isaksson, J.

1996-03-19T23:59:59.000Z

411

Tokamak reactor first wall  

DOE Patents (OSTI)

This invention relates to an improved first wall construction for a tokamak fusion reactor vessel, or other vessels subjected to similar pressure and thermal stresses.

Creedon, R.L.; Levine, H.E.; Wong, C.; Battaglia, J.

1984-11-20T23:59:59.000Z

412

Advanced Nuclear Research Reactor  

SciTech Connect

This report describes technical modifications implemented by INVAP to improve the safety of the Research Reactors the company designs and builds.

Lolich, J.V.

2004-10-06T23:59:59.000Z

413

HOMOGENEOUS NUCLEAR POWER REACTOR  

DOE Patents (OSTI)

A homogeneous nuclear power reactor utilizing forced circulation of the liquid fuel is described. The reactor does not require fuel handling outside of the reactor vessel during any normal operation including complete shutdown to room temperature, the reactor being selfregulating under extreme operating conditions and controlled by the thermal expansion of the liquid fuel. The liquid fuel utilized is a uranium, phosphoric acid, and water solution which requires no gus exhaust system or independent gas recombining system, thereby eliminating the handling of radioiytic gas.

King, L.D.P.

1959-09-01T23:59:59.000Z

414

Nucleation kinetics of vapor bubbles in a liquid with arbitrary viscosity  

E-Print Network (OSTI)

The theory of vapor bubbles nucleation in single-component liquids developed in [J. Phys. Chem. B 116, 9445 (2012)] for the case of high viscosity (the (V,/rho,T)- theory) is extended to the case of arbitrary viscosity. For this purpose, Langevin's approach in the theory of Brownian motion, or Kramers' model of chemical reactions, is employed. The obtained expression for the bubbles nucleation rate is valid for arbitrary relations between the kinetic parameters controlling the nucleation process: viscosity, inertia of a liquid, the rate of evaporation into a bubble and the rate of heat exchange between the bubble and ambient liquid. So, the presented theory together with the (V,/rho,T)- theory gives a complete description of the vapor-bubbles nucleation kinetics in one-component liquids. Limiting cases with respect to the mentioned parameters are considered, in particular, the low viscosity limit. It is shown that the low- and high-viscosity nucleation rates differ from each other qualitatively and quantitatively. The possibility of application of the theory to cavitation in superfluid helium-4 is discussed.

Nikolay V. Alekseechkin

2013-02-21T23:59:59.000Z

415

Spike deceleration and bubble acceleration in the ablative Rayleigh-Taylor instability  

Science Conference Proceedings (OSTI)

The nonlinear evolutions of the Rayleigh-Taylor instability (RTI) with preheat is investigated by numerical simulation (NS). A new phase of the spike deceleration evolution in the nonlinear ablative RTI (ARTI) is discovered. It is found that nonlinear evolution of the RTI can be divided into the weakly nonlinear regime (WNR) and the highly nonlinear regime (HNR) according to the difference of acceleration velocities for the spike and the bubble. With respect to the classical RTI (i.e., without heat conduction), the bubble first accelerates in the WNR and then decelerates in the HNR while the spike holds acceleration in the whole nonlinear regime (NR). With regard to the ARTI, on the contrary, the spike first accelerates in the WNR and then decelerates in the HNR while the bubble keeps acceleration in the whole NR. The NS results indicate that it is the nonlinear overpressure effect at the spike tip and the vorticity accumulation inside the bubble that lead to, respectively, the spike deceleration and bubble acceleration, in the nonlinear ARTI. In addition, it is found that in the ARTI the spike saturation velocity increases with the perturbation wavelength.

Ye, W. H.; He, X. T. [Department of Physics, Zhejiang University, Hangzhou 310027 (China); CAPT, Peking University, Beijing 100871 (China) and LCP, Institute of Applied Physics Computational Mathematics, Beijing 100088 (China); Wang, L. F. [CAPT, Peking University, Beijing 100871 (China) and LCP, Institute of Applied Physics Computational Mathematics, Beijing 100088 (China); SMCE, China University of Mining and Technology, Beijing 100083 (China)

2010-12-15T23:59:59.000Z

416

Bubble confinement in flow boiling of FC-72 in a ''rectangular'' microchannel of high aspect ratio  

SciTech Connect

Boiling in microchannels remains elusive due to the lack of full understanding of the mechanisms involved. A powerful tool in achieving better comprehension of the mechanisms is detailed imaging and analysis of the two-phase flow at a fundamental level. Boiling is induced in a single microchannel geometry (hydraulic diameter 727 {mu}m), using a refrigerant FC-72, to investigate the effect of channel confinement on bubble growth. A transparent, metallic, conductive deposit has been developed on the exterior of the rectangular microchannel, allowing simultaneous uniform heating and visualisation to be achieved. The data presented in this paper is for a particular case with a uniform heat flux applied to the microchannel and inlet liquid mass flowrate held constant. In conjunction with obtaining high-speed images and videos, sensitive pressure sensors are used to record the pressure drop across the microchannel over time. Bubble nucleation and growth, as well as periodic slug flow, are observed in the microchannel test section. The periodic pressure fluctuations evidenced across the microchannel are caused by the bubble dynamics and instances of vapour blockage during confined bubble growth in the channel. The variation of the aspect ratio and the interface velocities of the growing vapour slug over time, are all observed and analysed. We follow visually the nucleation and subsequent both 'free' and 'confined' growth of a vapour bubble during flow boiling of FC-72 in a microchannel, from analysis of our results, images and video sequences with the corresponding pressure data obtained. (author)

Barber, Jacqueline [School of Engineering, University of Edinburgh, The King's Buildings, Mayfield Road, Edinburgh, EH9 3JL (United Kingdom); Aix-Marseille Universite (UI, UII) - CNRS Laboratoire IUSTI, UMR 6595, 5 Rue Enrico Fermi, Marseille 13453 (France); Brutin, David; Tadrist, Lounes [Aix-Marseille Universite (UI, UII) - CNRS Laboratoire IUSTI, UMR 6595, 5 Rue Enrico Fermi, Marseille 13453 (France); Sefiane, Khellil [School of Engineering, University of Edinburgh, The King's Buildings, Mayfield Road, Edinburgh, EH9 3JL (United Kingdom)

2010-11-15T23:59:59.000Z

417

Magnetized and collimated millimeter scale plasma jets with astrophysical relevance  

Science Conference Proceedings (OSTI)

Magnetized collimated plasma jets are created in the laboratory to extend our understanding of plasma jet acceleration and collimation mechanisms with particular connection to astrophysical jets. In this study, plasma collimated jets are formed from supersonic unmagnetized flows, mimicking a stellar wind, subject to currents and magnetohydrodynamic forces. It is found that an external poloidal magnetic field, like the ones found anchored to accretion disks, is essential to stabilize the jets against current-driven instabilities. The maximum jet length before instabilities develop is proportional to the field strength and the length threshold agrees well with Kruskal-Shafranov theory. The plasma evolution is modeled qualitatively using MHD theory of current-carrying flux tubes showing that jet acceleration and collimation arise as a result of electromagnetic forces.

Brady, Parrish C.; Quevedo, Hernan J. [Texas Center for High Intensity Laser Science, University of Texas at Austin, Austin, Texas 78712 (United States); Valanju, Prashant M. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712-1060 (United States); Bengtson, Roger D.; Ditmire, Todd [Department of Physics, University of Texas at Austin, Austin, Texas 78712 (United States)

2012-01-15T23:59:59.000Z

418

Foreign Research Reactor/Domestic Research Reactor Receipt Coordinator...  

National Nuclear Security Administration (NNSA)

Research ReactorDomestic Research Reactor Receipt Coordinator, Savannah River Nuclear Solutions | National Nuclear Security Administration Our Mission Managing the Stockpile...

419

Random-Walk Monte Carlo Simulation of Intergranular Gas Bubble Nucleation in UO2 Fuel  

Science Conference Proceedings (OSTI)

Using a random-walk particle algorithm, we investigate the clustering of fission gas atoms on grain bound- aries in oxide fuels. The computational algorithm implemented in this work considers a planar surface representing a grain boundary on which particles appear at a rate dictated by the Booth flux, migrate two dimensionally according to their grain boundary diffusivity, and coalesce by random encounters. Specifically, the intergranular bubble nucleation density is the key variable we investigate using a parametric study in which the temperature, grain boundary gas diffusivity, and grain boundary segregation energy are varied. The results reveal that the grain boundary bubble nucleation density can vary widely due to these three parameters, which may be an important factor in the observed variability in intergranular bubble percolation among grain boundaries in oxide fuel during fission gas release.

Yongfeng Zhang; Michael R. Tonks; S. B. Biner; D.A. Andersson

2012-11-01T23:59:59.000Z

420

Gravitational wave generation from bubble collisions in first-order phase transitions: an analytic approach  

E-Print Network (OSTI)

Gravitational wave production from bubble collisions was calculated in the early nineties using numerical simulations. In this paper, we present an alternative analytic estimate, relying on a different treatment of stochasticity. In our approach, we provide a model for the bubble velocity power spectrum, suitable for both detonations and deflagrations. From this, we derive the anisotropic stress and analytically solve the gravitational wave equation. We provide analytical formulae for the peak frequency and the shape of the spectrum which we compare with numerical estimates. In contrast to the previous analysis, we do not work in the envelope approximation. This paper focuses on a particular source of gravitational waves from phase transitions. In a companion article, we will add together the different sources of gravitational wave signals from phase transitions: bubble collisions, turbulence and magnetic fields and discuss the prospects for probing the electroweak phase transition at LISA.

Caprini, Chiara; Servant, Géraldine

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "jet bubbling reactor" 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

Gravitational wave generation from bubble collisions in first-order phase transitions: an analytic approach  

E-Print Network (OSTI)

Gravitational wave production from bubble collisions was calculated in the early nineties using numerical simulations. In this paper, we present an alternative analytic estimate, relying on a different treatment of stochasticity. In our approach, we provide a model for the bubble velocity power spectrum, suitable for both detonations and deflagrations. From this, we derive the anisotropic stress and analytically solve the gravitational wave equation. We provide analytical formulae for the peak frequency and the shape of the spectrum which we compare with numerical estimates. In contrast to the previous analysis, we do not work in the envelope approximation. This paper focuses on a particular source of gravitational waves from phase transitions. In a companion article, we will add together the different sources of gravitational wave signals from phase transitions: bubble collisions, turbulence and magnetic fields and discuss the prospects for probing the electroweak phase transition at LISA.

Chiara Caprini; Ruth Durrer; Geraldine Servant

2007-11-16T23:59:59.000Z

422

ADMINISTRATION OF ORNL RESEARCH REACTORS  

SciTech Connect

Organization of the ORNL Operations division for administration of the Oak Ridge Research Reactor, the Low Intensity Testing Reactor, and the Oak Ridge Graphite Reactor is described. (J.R.D.)

Casto, W.R.

1962-08-20T23:59:59.000Z

423

Production reactor characteristics  

SciTech Connect

Reactors for the production of special nuclear materials share many similarities with commercial nuclear power plants. Each relies on nuclear fission, uses uranium fuel, and produces large quantities of thermal power. However, there are some important differences in production reactor characteristics that may best be discussed in terms of mission, role, and technology.

Thiessen, C.W.; Hootman, H.E.

1990-01-01T23:59:59.000Z

424

Advanced converter reactors  

SciTech Connect

Advanced converter reactors (ACRs) of primary US interest are those which can be commercialized within about 20 years, and are: Advanced Light-Water Reactors, Spectral-Shift-Control Reactors, Heavy-Water Reactors (CANDU type), and High-Temperature Gas-Cooled Reactors. These reactors can operate on uranium, thorium, or uranium-thorium fuel cycles, but have the greatest fuel utilization on thorium type cycles. The water reactors tend to operate more economically on uranium cycles, while the HTGR is more economical on thorium cycles. Thus, the HTGR had the greatest practical potential for improving fuel utilization. If the US has 3.4 to 4 million tons U/sub 3/O/sub 8/ at reasonable costs, ACRs can make important contributions to maintaining a high nuclear power level for many decades; further, they work well with fast breeder reactors in the long term under symbiotic fueling conditions. Primary nuclear data needs of ACRs are integral measurements of reactivity coefficients and resonance absorption integrals.

Kasten, P.R.

1979-01-01T23:59:59.000Z

425

NEUTRONIC REACTOR SYSTEM  

DOE Patents (OSTI)

A reactor system incorporating a reactor of the heterogeneous boiling water type is described. The reactor is comprised essentially of a core submerged adwater in the lower half of a pressure vessel and two distribution rings connected to a source of water are disposed within the pressure vessel above the reactor core, the lower distribution ring being submerged adjacent to the uppcr end of the reactor core and the other distribution ring being located adjacent to the top of the pressure vessel. A feed-water control valve, responsive to the steam demand of the load, is provided in the feedwater line to the distribution rings and regulates the amount of feed water flowing to each distribution ring, the proportion of water flowing to the submerged distribution ring being proportional to the steam demand of the load. This invention provides an automatic means exterior to the reactor to control the reactivity of the reactor over relatively long periods of time without relying upon movement of control rods or of other moving parts within the reactor structure.

Treshow, M.

1959-02-10T23:59:59.000Z

426

NEUTRONIC REACTOR BURIAL ASSEMBLY  

DOE Patents (OSTI)

A burial assembly is shown whereby an entire reactor core may be encased with lead shielding, withdrawn from the reactor site and buried. This is made possible by a five-piece interlocking arrangement that may be easily put together by remote control with no aligning of bolt holes or other such close adjustments being necessary.

Treshow, M.

1961-05-01T23:59:59.000Z

427

The Integral Fast Reactor  

SciTech Connect

Argonne National Laboratory, since 1984, has been developing the Integral Fast Reactor (IFR). This paper will describe the way in which this new reactor concept came about; the technical, public acceptance, and environmental issues that are addressed by the IFR; the technical progress that has been made; and our expectations for this program in the near term. 5 refs., 3 figs.

Till, C.E.; Chang, Y.I. (Argonne National Lab., IL (USA)); Lineberry, M.J. (Argonne National Lab., Idaho Falls, ID (USA))

1990-01-01T23:59:59.000Z

428

Creating Small Gas Bubbles in Flowing Mercury Using Turbulence at an Orifice  

Science Conference Proceedings (OSTI)

Pressure waves created in liquid mercury pulsed spallation targets have been shown to create cavitation damage to the target container. One way to mitigate such damage would be to absorb the pressure pulse energy into a dispersed population of small bubbles, however, creating such a population in mercury is difficult due to the high surface tension and particularly the non-wetting behavior of mercury on gas-injection hardware. If the larger injected gas bubbles can be broken down into small bubbles after they are introduced to the flow, then the material interface problem is avoided. Research at the Oak Ridge National Labarotory is underway to develop a technique that has shown potential to provide an adequate population of small-enough bubbles to a flowing spallation target. This technique involves gas injection at an orifice of a geometry that is optimized to the turbulence intensity and pressure distribution of the flow, while avoiding coalescence of gas at injection sites. The most successful geometry thus far can be described as a square-toothed orifice having a 2.5 bar pressure drop in the nominal flow of 12 L/s for one of the target inlet legs. High-speed video and high-resolution photography have been used to quantify the bubble population on the surface of the mercury downstream of the gas injection sight. Also, computational fluid dynamics has been used to optimize the dimensions of the toothed orifice based on a RANS computed mean flow including turbulent energies such that the turbulent dissipation and pressure field are best suited for turbulent break-up of the gas bubbles.

Wendel, Mark W [ORNL; Abdou, Ashraf A [ORNL; Paquit, Vincent C [ORNL; Felde, David K [ORNL; Riemer, Bernie [ORNL

2010-01-01T23:59:59.000Z

429

Gas Bubble Disease Monitoring and Research of Juvenile Salmonids : Annual Report 1996.  

DOE Green Energy (OSTI)

This document describes the project activities 1996--1997 contract year. This report is composed of three chapters which contain data and analyses of the three main elements of the project: field research to determine the vertical distribution of migrating juvenile salmonids, monitoring of juvenile migrants at dams on the Snake and Columbia rivers, and laboratory experiments to describe the progression of gas bubble disease signs leading to mortality. The major findings described in this report are: A miniature pressure-sensitive radio transmitter was found to be accurate and precise and, after compensation for water temperature, can be used to determine the depth of tagged-fish to within 0.32 m of the true depth (Chapter 1). Preliminary data from very few fish suggest that depth protects migrating juvenile steelhead from total dissolved gas supersaturation (Chapter 1). As in 1995, few fish had any signs of gas bubble disease, but it appeared that prevalence and severity increased as fish migrated downstream and in response to changing gas supersaturation (Chapter 2). It appeared to gas bubble disease was not a threat to migrating juvenile salmonids when total dissolved gas supersaturation was < 120% (Chapter 2). Laboratory studies suggest that external examinations are appropriate for determining the severity of gas bubble disease in juvenile salmonids (Chapter 3). The authors developed a new method for examining gill arches for intravascular bubbles by clamping the ventral aorta to reduce bleeding when arches were removed (Chapter 3). Despite an outbreak of bacterial kidney disease in the experimental fish, the data indicate that gas bubble disease is a progressive trauma that can be monitored (Chapter 3).

Maule, Alec G.; Beeman, John W.; Hans, Karen M.; Mesa, M.G.; Haner, P.; Warren, J.J. [Geological Survey, Cook, WA (United States). Columbia River Research Lab.

1997-10-01T23:59:59.000Z

430

Energy enhancement of proton acceleration in combinational radiation pressure and bubble by optimizing plasma density  

Science Conference Proceedings (OSTI)

The combinational laser radiation pressure and plasma bubble fields to accelerate protons are researched through theoretical analysis and numerical simulations. The dephasing length of the accelerated protons bunch in the front of the bubble and the density gradient effect of background plasma on the accelerating phase are analyzed in detail theoretically. The radiation damping effect on the accelerated protons energy is also considered. And it is demonstrated by two-dimensional particle-in-cell simulations that the protons bunch energy can be increased by using the background plasma with negative density gradient. However, radiation damping makes the maximal energy of the accelerated protons a little reduction.

Bake, Muhammad Ali; Xie Baisong [Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Shan Zhang [Department of Mathematics and Physics, Shijiazhuang Tiedao University, Shijiazhuang 050043 (China); Hong Xueren [College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); Wang Hongyu [Department of Physics, Anshan Normal University, Anshan 114005 (China); Shanghai Bright-Tech Information Technology Co. Ltd, Shanghai 200136 (China)

2012-08-15T23:59:59.000Z

431

Synchrotron Radiation from a Laser Plasma Accelerator in the Bubble Regime  

Science Conference Proceedings (OSTI)

A laser wakefield accelerator is shown to operate in the highly non-linear bubble regime, following the characteristic scaling of energy gain with density and leading to monoenergetic electron beams with up to 400 MeV and hundreds of pC charge. The bubble acts at the same time as a miniature undulator, causing the electrons to give off a beam of betatron x-rays with milliradian divergence, {mu}m source size, 1-100 keV photon energy and 10{sup 22} ph/mm{sup 2}/mrad{sup 2}s/0.1% BW.

Kneip, S. [Blackett Laboratory, Imperial College London, London, SW7 2BZ (United Kingdom); Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, MI, 48109 (United States); McGuffey, C.; Chvykov, V.; Dollar, F.; Kalintchenko, G.; Maksimchuk, T.; Matsuoka, T.; Thomas, A. G. R.; Krushelnick, K. [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, MI, 48109 (United States); Mangles, S. P. D.; Nagel, S. R.; Palmer, C. A. J.; Schreiber, J.; Najmudin, Z. [Blackett Laboratory, Imperial College London, London, SW7 2BZ (United Kingdom); Ta Phuoc, K. [Laboratoire d'Optique Appliquee, ENSTA, Ecole Polytechnique, Palaiseau, 91761 (France)

2010-11-04T23:59:59.000Z

432

Analytic model of electron self-injection in a plasma wakefield accelerator in the strongly nonlinear bubble regime  

Science Conference Proceedings (OSTI)

Self-injection of background electrons in plasma wakefield accelerators in the highly nonlinear bubble regime is analyzed using particle-in-cell and semi-analytic modeling. It is shown that the return current in the bubble sheath layer is crucial for accurate determination of the trapped particle trajectories.

Yi, S. A.; Khudik, V.; Siemon, C.; Shvets, G. [Department of Physics and Institute for Fusion Studies, University of Texas at Austin, One University Station C1500, Austin, Texas (United States)

2012-12-21T23:59:59.000Z

433

REACTOR DEVELOPMENT PROGRAM PROGRESS REPORT  

SciTech Connect

Progress on reactor programs and in general engineering research and development programs is summarized. Research and development are reported on water-cooled reactors including EBWR and Borax-V, sodium-cooled reactors including ZPR-III, IV, and IX, Juggernaut, and EBR-I and II. Other work included a review of fast reactor technology, and studies on nuclear superheat, thermal and fast reactor safety, and reactor physics. Effort was also devoted to reactor materials and fuels development, heat engineering, separation processes and advanced reactor concepts. (J.R.D.)

1961-04-01T23:59:59.000Z

434

Fundamental study on transient bubble (slug) behavior by characterizing transient forces of solid particles in fluidized beds. 1990 Annual report  

SciTech Connect

The objective of this work is to recognize and interpret the signals of transient motion of bubbles (slugs) in fluidized beds by measuring and utilizing the signals of transient motion of solid particles. The two signals were measured simultaneously and also synchronized by using the TTL signal technique in the same fluidized beds. Also, a simultaneous study of video bubble image, transient force and pressure signals was initiated in a two dimensional fluidized bed. we successfully synchronized three signals so that the relationship of bubble behavior and force pressure signals can be identified and characterized. It has been found that bubble image can well be correlated to the transient force signal of solid particles under certain conditions in three dimensional fluidized beds. Accordingly, it seems that the transient force signals can significantly help understanding the transient motion of bubbles (slugs), which is important to design the fluidized beds.

Kono, H.O.

1991-01-01T23:59:59.000Z

435

Fundamental study on transient bubble (slug) behavior by characterizing transient forces of solid particles in fluidized beds  

Science Conference Proceedings (OSTI)

The objective of this work is to recognize and interpret the signals of transient motion of bubbles (slugs) in fluidized beds by measuring and utilizing the signals of transient motion of solid particles. The two signals were measured simultaneously and also synchronized by using the TTL signal technique in the same fluidized beds. Also, a simultaneous study of video bubble image, transient force and pressure signals was initiated in a two dimensional fluidized bed. we successfully synchronized three signals so that the relationship of bubble behavior and force pressure signals can be identified and characterized. It has been found that bubble image can well be correlated to the transient force signal of solid particles under certain conditions in three dimensional fluidized beds. Accordingly, it seems that the transient force signals can significantly help understanding the transient motion of bubbles (slugs), which is important to design the fluidized beds.

Kono, H.O.

1991-01-01T23:59:59.000Z

436

Transmission Line Analogy for Relativistic Poynting-Flux Jets  

E-Print Network (OSTI)

Radio emission, polarization, and Faraday rotation maps of the radio jet of the galaxy 3C 303 have shown that one knot of this jet carries a {\\it galactic}-scale electric current and that it is magnetically dominated. We develop the theory of magnetically dominated or Poynting-flux jets by making an analogy of a Poynting jet with a transmission line or waveguide carrying a net current and having a potential drop across it (from the jet's axis to its radius) and a definite impedance which we derive. Time-dependent but not necessarily small perturbations of a Poynting-flux jet are described by the "telegrapher's equations." These predict the propagation speed of disturbances and the effective wave impedance for forward and backward propagating wave components. A localized disturbance of a Poynting jet gives rise to localized dissipation in the jet which may explain the enhanced synchrotron radiation in the knots of the 3C 303 jet, and also in the apparently stationary knot HST-1 in the jet near the nucleus of t...

Lovelace, R V E

2012-01-01T23:59:59.000Z

437

Cryogenic target formation using cold gas jets  

DOE Patents (OSTI)

A method and apparatus using cold gas jets for producing a substantially uniform layer of cryogenic materials on the inner surface of hollow spherical members having one or more layers, such as inertially imploded targets are disclosed. By vaporizing and quickly refreezing cryogenic materials contained within a hollow spherical member, a uniform layer of the materials is formed on an inner surface of the spherical member. Basically the method involves directing cold gas jets onto a spherical member having one or more layers or shells and containing the cryogenic material, such as a deuterium-tritium (DT) mixture, to freeze the contained material, momentarily heating the spherical member so as to vaporize the contained material, and quickly refreezing the thus vaporized material forming a uniform layer of cryogenic material on an inner surface of the spherical member. 4 figs.

Hendricks, C.D.

1980-02-26T23:59:59.000Z

438

Catalytic Fast Pyrolysis of Biomass in a Bubbling Fluidized Bed Reactor with Gallium Promoted ZSM-5 Catalyst.  

E-Print Network (OSTI)

??The huge energy demand of our society is causing fossil fuel resources to diminish rapidly. Therefore, it is critical to search for alternative energy resources.… (more)

Shi, Jian

2012-01-01T23:59:59.000Z

439

ON THE ORIGIN OF INTERGRANULAR JETS  

SciTech Connect

We observe that intergranular jets, originating in the intergranular space surrounding individual granules, tend to be associated with granular fragmentation, in particular, with the formation and evolution of a bright granular lane (BGL) within individual granules. The BGLs have recently been identified as vortex tubes by Steiner et al. We further discover the development of a well-defined bright grain located between the BGL and the dark intergranular lane to which it is connected. Signatures of a BGL may reach the lower chromosphere and can be detected in off-band H{alpha} images. Simulations also indicate that vortex tubes are frequently associated with small-scale magnetic fields. We speculate that the intergranular jets detected in the New Solar Telescope (NST) data may result from the interaction between the turbulent small-scale fields associated with the vortex tube and the larger-scale fields existing in the intergranular lanes. The intergranular jets are much smaller and weaker than all previously known jet-like events. At the same time, they appear much more numerous than the larger events, leading us to the speculation that the total energy release and mass transport by these tiny events may not be negligible in the energy and mass-flux balance near the temperature minimum atop the photosphere. The study is based on the photospheric TiO broadband (1.0 nm) filter data acquired with the 1.6 m NST operating at the Big Bear Solar Observatory. The data set also includes NST off-band H{alpha} images collected through a Zeiss Lyot filter with a passband of 0.025 nm.

Yurchyshyn, V. B.; Goode, P. R.; Abramenko, V. I. [Big Bear Solar Observatory, New Jersey Institute of Technology, Big Bear City, CA 92314 (United States); Steiner, O. [Kiepenheuer-Institut fuer Sonnenphysik, Schoeneckstrasse 6, D-79104 Freiburg (Germany)

2011-08-01T23:59:59.000Z

440

Nuclear reactor control column  

DOE Patents (OSTI)

The nuclear reactor control column comprises a column disposed within the nuclear reactor core having a variable cross-section hollow channel and containing balls whose vertical location is determined by the flow of the reactor coolant through the column. The control column is divided into three basic sections wherein each of the sections has a different cross-sectional area. The uppermost section of the control column has the greatest cross-sectional area, the intermediate section of the control column has the smallest cross-sectional area, and the lowermost section of the control column has the intermediate cross-sectional area. In this manner, the area of the uppermost section can be established such that when the reactor coolant is flowing under normal conditions therethrough, the absorber balls will be lifted and suspended in a fluidized bed manner in the upper section. However, when the reactor coolant flow falls below a predetermined value, the absorber balls will fall through the intermediate section and into the lowermost section, thereby reducing the reactivity of the reactor core and shutting down the reactor.

Bachovchin, Dennis M. (Plum Borough, PA)

1982-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "jet bubbling reactor" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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to obtain the most current and comprehensive results.


441

Slurry reactor design studies  

SciTech Connect

The objective of these studies was to perform a realistic evaluation of the relative costs of tublar-fixed-bed and slurry reactors for methanol, mixed alcohols and Fischer-Tropsch syntheses under conditions where they would realistically be expected to operate. The slurry Fischer-Tropsch reactor was, therefore, operated at low H{sub 2}/CO ratio on gas directly from a Shell gasifier. The fixed-bed reactor was operated on 2.0 H{sub 2}/CO ratio gas after adjustment by shift and CO{sub 2} removal. Every attempt was made to give each reactor the benefit of its optimum design condition and correlations were developed to extend the models beyond the range of the experimental pilot plant data. For the methanol design, comparisons were made for a recycle plant with high methanol yield, this being the standard design condition. It is recognized that this is not necessarily the optimum application for the slurry reactor, which is being proposed for a once-through operation, coproducing methanol and power. Consideration is also given to the applicability of the slurry reactor to mixed alcohols, based on conditions provided by Lurgi for an Octamix{trademark} plant using their standard tubular-fixed reactor technology. 7 figs., 26 tabs.

Fox, J.M.; Degen, B.D.; Cady, G.; Deslate, F.D.; Summers, R.L. (Bechtel Group, Inc., San Francisco, CA (USA)); Akgerman, A. (Texas A and M Univ., College Station, TX (USA)); Smith, J.M. (California Univ., Davis, CA (USA))

1990-06-01T23:59:59.000Z

442

Event-by-event jet quenching  

SciTech Connect

High momentum jets and hadrons can be used as probes for the quark gluon plasma (QGP) formed in nuclear collisions at high energies. We investigate the influence of fluctuations in the fireball on jet quenching observables by comparing propagation of light quarks and gluons through averaged, smooth QGP fireballs with event-by-event jet quenching using realistic inhomogeneous fireballs. We find that the transverse momentum and impact parameter dependence of the nuclear modification factor R{sub AA} can be fit well in an event-by-event quenching scenario within experimental errors. However the transport coefficient {cflx q} extracted from fits to the measured nuclear modification factor R{sub AA} in averaged fireballs underestimates the value from event-by-event calculations by up to 50%. On the other hand, after adjusting {cflx q} to fit R{sub AA} in the event-by-event analysis we find residual deviations in the azimuthal asymmetry v{sub 2} and in two-particle correlations, that provide a possible faint signature for a spatial tomography of the fireball. We discuss a correlation function that is a measure for spatial inhomogeneities in a collision and can be constrained from data.

Fries, R.J.; Rodriguez, R.; Ramirez, E.

2010-08-14T23:59:59.000Z

443

Ejector device for direct injection fuel jet  

SciTech Connect

Disclosed is a device for increasing entrainment and mixing in an air/fuel zone of a direct fuel injection system. The device comprises an ejector nozzle in the form of an inverted funnel whose central axis is aligned along the central axis of a fuel injector jet and whose narrow end is placed just above the jet outlet. It is found that effective ejector performance is achieved when the ejector geometry is adjusted such that it comprises a funnel whose interior surface diverges about 7.degree. to about 9.degree. away from the funnel central axis, wherein the funnel inlet diameter is about 2 to about 3 times the diameter of the injected fuel plume as the fuel plume reaches the ejector inlet, and wherein the funnel length equal to about 1 to about 4 times the ejector inlet diameter. Moreover, the ejector is most effectively disposed at a separation distance away from the fuel jet equal to about 1 to about 2 time the ejector inlet diameter.

Upatnieks, Ansis (Livermore, CA)

2006-05-30T23:59:59.000Z

444

Numerical Analysis of the Dynamics of Two- and Three-Dimensional Fluidized Bed Reactors using an Euler-Lagrange Approach  

SciTech Connect

Biomass thermochemical conversion, often done in fluidized beds, recently gained a lot of attention due to its potential to efficiently produce renewable liquid fuels. Optimization of reactor design and operating conditions, however, requires a fundamental understanding of bed dynamics. In this work, a numerical framework based on an Euler-Lagrange approach is developed and used to perform and analyze large-scale simulations of two- and three-dimensional periodic fluidized beds. Collisions are handled using a soft-sphere model. An efficient parallel implementation allows one to explicitly track over 30 million particles, which is representative of the number of particles found in lab-scale reactor, therefore demonstrating the capability of Lagrangian approaches to simulate realistic systems at that scale. An on-the-fly bubble identification and tracking algorithm is used to characterize bubble dynamics for inlet velocities up to 9 times the minimum fluidization velocity. Statistics for gas volume fraction, gas and particle velocities, bed expansion, and bubble size and velocity, is compared across the two- and three-dimensional configurations, and comparison with literature data generally shows good agreement. The wide distribution of gas residence times observed in the simulations is linked to the different gas hold-up characteristics of the gas-solid system.

Pepiot, P.; Desjardins, O.

2012-04-01T23:59:59.000Z

445

Nuclear reactor reflector  

DOE Patents (OSTI)

A nuclear reactor reflector is disclosed that comprises a stack of reflector blocks with vertical water flow passages to cool the reflector. The interface between blocks is opposite support points for reactor fuel rods. Water flows between the reflector and the reactor barrel from passages in a bottom block. The top block contains a flange to limit this flow and the flange has a slot to receive an alignment pin that is welded to the barrel. The pin is held in the slot by two removable shims. Alignment bars extend the length of the stack in slots machined in each block when the stack is assembled.

Hopkins, Ronald J. (Pensacola, FL); Land, John T. (Pensacola, FL); Misvel, Michael C. (Pensacola, FL)

1994-01-01T23:59:59.000Z

446

Nuclear reactor reflector  

DOE Patents (OSTI)

A nuclear reactor reflector is disclosed that comprises a stack of reflector blocks with vertical water flow passages to cool the reflector. The interface between blocks is opposite support points for reactor fuel rods. Water flows between the reflector and the reactor barrel from passages in a bottom block. The top block contains a flange to limit this flow and the flange has a slot to receive an alignment pin that is welded to the barrel. The pin is held in the slot by two removable shims. Alignment bars extend the length of the stack in slots machined in each block when the stack is assembled. 12 figs.

Hopkins, R.J.; Land, J.T.; Misvel, M.C.

1994-06-07T23:59:59.000Z

447

Microfluidic electrochemical reactors  

DOE Patents (OSTI)

A microfluidic electrochemical reactor includes an electrode and one or more microfluidic channels on the electrode, where the microfluidic channels are covered with a membrane containing a gas permeable polymer. The distance between the electrode and the membrane is less than 500 micrometers. The microfluidic electrochemical reactor can provide for increased reaction rates in electrochemical reactions using a gaseous reactant, as compared to conventional electrochemical cells. Microfluidic electrochemical reactors can be incorporated into devices for applications such as fuel cells, electrochemical analysis, microfluidic actuation, pH gradient formation.

Nuzzo, Ralph G. (Champaign, IL); Mitrovski, Svetlana M. (Urbana, IL)

2011-03-22T23:59:59.000Z

448

Fast Breeder Reactor studies  

Science Conference Proceedings (OSTI)

This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts.

Till, C.E.; Chang, Y.I.; Kittel, J.H.; Fauske, H.K.; Lineberry, M.J.; Stevenson, M.G.; Amundson, P.I.; Dance, K.D.

1980-07-01T23:59:59.000Z

449

NUCLEAR REACTOR FUEL SYSTEMS  

DOE Patents (OSTI)

Homogeneous reactor fuel solutions are reported which provide automatic recombination of radiolytic gases and exhibit large thermal expansion characteristics, thereby providing stability at high temperatures and enabling reactor operation without the necessity of apparatus to recombine gases formed by the radiolytic dissociation of water in the fuel and without the necessity of liquid fuel handling outside the reactor vessel except for recovery processes. The fuels consist of phosphoric acid and water solutions of enriched uranium, wherein the uranium is in either the hexavalent or tetravalent state.

Thamer, B.J.; Bidwell, R.M.; Hammond, R.P.

1959-09-15T23:59:59.000Z

450

Spherical torus fusion reactor  

DOE Patents (OSTI)

The object of this invention is to provide a compact torus fusion reactor with dramatic simplification of plasma confinement design. Another object of this invention is to provide a compact torus fusion reactor with low magnetic field and small aspect ratio stable plasma confinement. In accordance with the principles of this invention there is provided a compact toroidal-type plasma confinement fusion reactor in which only the indispensable components inboard of a tokamak type of plasma confinement region, mainly a current conducting medium which carries electrical current for producing a toroidal magnet confinement field about the toroidal plasma region, are retained.

Martin Peng, Y.K.M.

1985-10-03T23:59:59.000Z

451

CONTROL FOR NEUTRONIC REACTOR  

DOE Patents (OSTI)

S>A control rod operating device in a nuclear reactor of the type in which the control rod is gradually withdrawn from the reactor to a position desired during stable operation is described. The apparatus is comprised essentially of a stop member movable in the direction of withdrawal of the control rod, a follower on the control rod engageable with the stop and means urging the follower against the stop in the direction of withdrawal. A means responsive to disengagement of the follower from the stop is provided for actuating the control rod to return to the reactor shut-down position.

Lichtenberger, H.V.; Cameron, R.A.

1959-03-31T23:59:59.000Z

452

Composition, collimation, contamination: the jet of Cygnus X-1  

E-Print Network (OSTI)

We model the observed size and brightness of the VLBA radio core of the jet in Cygnus X-1 to derive an expression for the jet power as a function of basic jet parameters. We apply this expression to recent constraints on the jet power from observations of a large scale shocked shell around the source by Gallo et al. 2005, which leads us to a set of alternative conclusions: either (a) the jet contains large amounts of protons: more than 2000 protons per radio emitting electron, (b) it has a very low radio volume filling factor of f source of the kinetic energy powering the ISM shell, or (d) its asymptotic behavior differs fundamentally from a broad set of plausible analytic jet models.

Sebastian Heinz

2005-09-26T23:59:59.000Z

453

Dissolution of carbon dioxide bubbles and microfluidic multiphase flows Ruopeng Sun and Thomas Cubaud*  

E-Print Network (OSTI)

. Introduction Carbon dioxide gas is widespread in natural and industrial processes. At the small scale composition and the gas injection pressure. For short periods of time, ``sharp'' concentration gradients and the channel geometry. By contrast, the bubble dissolution rate is found to depend on the inlet gas pressure

Cubaud, Thomas

454

Bubble merger model for the nonlinear Rayleigh-Taylor instability driven by a strong blast wave  

Science Conference Proceedings (OSTI)

A bubble merger model is presented for the nonlinear evolution of the Rayleigh-Taylor instability driven by a strong blast wave. Single bubble motion is determined by an extension of previous buoyancy-drag models extended to the blast wave driven case, and a simple bubble merger law in the spirit of the Sharp-Wheeler model allows for the generation of larger scales. The blast wave driven case differs in several respects from the classical case of incompressible fluids in a uniform gravitational field. Because of material decompression in the rarefaction behind the blast front, the asymptotic bubble velocity and the merger time depend on time as well as the transverse scale and the drive. For planar blast waves, this precludes the emergence of a self-similar regime independent of the initial conditions. With higher-dimensional blast waves, divergence restores the properties necessary for the establishment of the self-similar state, but its establishment requires a very high initial characteristic mode number and a high Mach number for the incident blast wave.

Miles, A R

2004-03-18T23:59:59.000Z

455

A Gas-Capture Buoy for Measuring Bubbling Gas Flux in Oceans and Lakes  

Science Conference Proceedings (OSTI)

The design, calibration, and deployment of a buoy and gas-capture assembly for measuring bubbling gas flux in oceans and lakes are described. The assembly collects gas in a chamber while continuously measuring the position of the gas–water ...

Libe Washburn; Cyril Johnson; Chris C. Gotschalk; E. Thor Egland

2001-08-01T23:59:59.000Z

456

Vibration and Nonlinear Resonance in the Break-up of an Underwater Bubble  

E-Print Network (OSTI)

We use high-speed X-ray phase-contrast imaging, weakly nonlinear analysis and boundary integral simulations to characterize the final stage of underwater bubble break-up. The X-ray imaging study shows that an initial azimuthal perturbation to the shape of the bubble neck gives rise to oscillations that increasingly distort the cross-section shape. These oscillations terminate in a pinch-off where the bubble surface develops concave regions that contact similar to what occurs when two liquid drops coalesce. We also present a weakly nonlinear analysis that shows that this coalescence-like mode of pinch-off occurs when the initial shape oscillation interferes constructively with the higher harmonics it generates and thus reinforce each other's effects in bringing about bubble break-up. Finally we present numerical results that confirm the weakly nonlinear analysis scenario as well as provide insight into observed shape reversals. They demonstrate that when the oscillations interfere destructively, a qualitativel...

Lai, Lipeng; Fezzaa, Kamel; Zhang, Wendy W; Nagel, Sidney R

2013-01-01T23:59:59.000Z

457

Can Propagation of Gas Bubbles Lead to Detached Solidification? Experiments on Freezing of Water  

E-Print Network (OSTI)

. The ampoules were ap- proximately 30-cm long and were filled to about 12 cm with water. The heater velocity versus heater temperature. The water was saturated with air and the ampoule was coated with TeflonCan Propagation of Gas Bubbles Lead to Detached Solidification? Experiments on Freezing of Water

Regel, Liya L.

458

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

SciTech Connect

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

459

FARADAY ROTATION DISTRIBUTIONS FROM STELLAR MAGNETISM IN WIND-BLOWN BUBBLES  

SciTech Connect

Faraday rotation is a valuable tool for detecting magnetic fields. Here, the technique is considered in relation to wind-blown bubbles. In the context of spherical winds with azimuthal or split monopole stellar magnetic field geometries, we derive maps of the distribution of position angle (P.A.) rotation of linearly polarized radiation across projected bubbles. We show that the morphology of maps for split monopole fields are distinct from those produced by the toroidal field topology; however, the toroidal case is the one most likely to be detectable because of its slower decline in field strength with distance from the star. We also consider the important case of a bubble with a spherical sub-volume that is field-free to approximate crudely a 'swept-up' wind interaction between a fast wind (or possibly a supernova ejecta shell) overtaking a slower magnetized wind from a prior state of stellar evolution. With an azimuthal field, the resultant P.A. map displays two arc-like features of opposite rotation measure, similar to observations of the supernova remnant G296.5+10.0. We illustrate how P.A. maps can be used to disentangle Faraday rotation contributions made by the interstellar medium versus the bubble. Although our models involve simplifying assumptions, their consideration leads to a number of general robust conclusions for use in the analysis of radio mapping data sets.

Ignace, R. [Department of Physics and Astronomy, East Tennessee State University, Johnson City, TN 37614 (United States)] [Department of Physics and Astronomy, East Tennessee State University, Johnson City, TN 37614 (United States); Pingel, N. M., E-mail: ignace@etsu.edu, E-mail: nmpingle@wisc.edu [Department of Astronomy, University of Wisconsin-Madison, Madison, WI 53711 (United States)

2013-03-01T23:59:59.000Z

460

Neutralization of H/sup -/ beams with gas jets  

DOE Green Energy (OSTI)

A test facility was constructed to create a compact curtain-shaped gas jet as a first-generation operational neutralizer for the 150 keV H/sup -/ beam. Different gases and vapors were considered, their optimum target thicknesses and neutralization efficiencies with respect to beam energies were explored. Two techniques of gas jet formation were compared. Multiparallel-channel effusive jets of CO/sub 2/ and H/sub 2/ were selected as test candidates.

Lam, C.K.

1977-01-01T23:59:59.000Z

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461

MEASURING THE JET POWER OF FLAT-SPECTRUM RADIO QUASARS  

SciTech Connect

We use frequency-dependent position shifts of flat-spectrum radio cores to estimate the kinetic power of active galactic nucleus (AGN) jets. We find a correlation between the derived jet powers and AGN narrow-line luminosity, consistent with the well-known relation for radio galaxies and steep spectrum quasars. This technique can be applied to intrinsically weak jets even at high redshift.

Shabala, S. S.; Santoso, J. S. [School of Mathematics and Physics, University of Tasmania, Private Bag 37, Hobart, TAS 7001 (Australia); Godfrey, L. E. H. [International Centre for Radio Astronomy Research, Curtin University, GPO Box U1987, Perth, Western Australia 6845 (Australia)

2012-09-10T23:59:59.000Z

462

Reactor hot spot analysis  

SciTech Connect

The principle methods for performing reactor hot spot analysis are reviewed and examined for potential use in the Applied Physics Division. The semistatistical horizontal method is recommended for future work and is now available as an option in the SE2-ANL core thermal hydraulic code. The semistatistical horizontal method is applied to a small LMR to illustrate the calculation of cladding midwall and fuel centerline hot spot temperatures. The example includes a listing of uncertainties, estimates for their magnitudes, computation of hot spot subfactor values and calculation of two sigma temperatures. A review of the uncertainties that affect liquid metal fast reactors is also presented. It was found that hot spot subfactor magnitudes are strongly dependent on the reactor design and therefore reactor specific details must be carefully studied. 13 refs., 1 fig., 5 tabs.

Vilim, R.B.

1985-08-01T23:59:59.000Z

463

Reactor Thermal-Hydraulics  

NLE Websites -- All DOE Office Websites (Extended Search)

Thermal-Hydraulics Thermal-Hydraulics Dr. Tanju Sofu, Argonne National Laboratory In a power reactor, the energy produced in fission reaction manifests itself as heat to be removed by a coolant and utilized in a thermodynamic energy conversion cycle to produce electricity. A simplified schematic of a typical nuclear power plant is shown in the diagram below. Primary coolant loop Steam Reactor Heat exchanger Primary pump Secondary pump Condenser Turbine Water Although this process is essentially the same as in any other steam plant configuration, the power density in a nuclear reactor core is typically four orders of magnitude higher than a fossil fueled plant and therefore it poses significant heat transfer challenges. Maximum power that can be obtained from a nuclear reactor is often limited by the

464

Compact power reactor  

DOE Patents (OSTI)

There is disclosed a small compact nuclear reactor operating in the epithermal neutron energy range for supplying power at remote locations, as for a satellite. The core contains fuel moderator elements of Zr hydride with 7 w/o of 93% enriched uranium alloy. The core has a radial beryllium reflector and is cooled by liquid metal coolant such as NaK. The reactor is controlled and shut down by moving portions of the reflector.

Wetch, Joseph R. (Woodland Hills, CA); Dieckamp, Herman M. (Canoga Park, CA); Wilson, Lewis A. (Canoga Park, CA)

1978-01-01T23:59:59.000Z

465

Molten metal reactors  

SciTech Connect

A molten metal reactor for converting a carbon material and steam into a gas comprising hydrogen, carbon monoxide, and carbon dioxide is disclosed. The reactor includes an interior crucible having a portion contained within an exterior crucible. The interior crucible includes an inlet and an outlet; the outlet leads to the exterior crucible and may comprise a diffuser. The exterior crucible may contain a molten alkaline metal compound. Contained between the exterior crucible and the interior crucible is at least one baffle.

Bingham, Dennis N; Klingler, Kerry M; Turner, Terry D; Wilding, Bruce M

2013-11-05T23:59:59.000Z

466

Choked-Flow Inlet Orifice Bubbler for Creating Small Bubbles in Mercury  

Science Conference Proceedings (OSTI)

Pressure waves created in liquid mercury pulsed spallation targets like the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory, induce cavitation damage on the target container. The cavitation damage is thought to limit the lifetime of the target for power levels at and above 1 MW. One way to mitigate the damage would be to absorb the pressure pulse energy into a dispersed population of small bubbles, however, creating a bubble size distribution that is sufficiently large and disperse in mercury is challenging due to the high surface tension. Also, measuring the population is complicated by the opacity and the high level of turbulent mixing. Recent advances in bubble diagnostics by batch sampling the mercury made it possible to compare bubble populations for different techniques in a SNS-1/20th scale test loop. More than 10 bubblers were tested and the most productive bubblers were taken for in-beam testing at the Los Alamos Neutron Science Center (LANSCE) WNR user facility. One bubbler design, referred to as the inlet-orifice bubbler, that showed moderate success in creating populations also has an added advantage that it could easily be included in the existing SNS full-scale mercury target configuration. Improvements to the bubbler were planned including a reduction of the nozzle size to choke the gas injection, thus steadying the injected mass flow and allowing multiple nozzles to work off of a common plenum. For the first time, reliable bubble population data are available in the prototypical target geometry and can be compared with populations that mitigated cavitation damage. This paper presents those experimental results.

Wendel, Mark W [ORNL; Abdou, Ashraf A [ORNL; Riemer, Bernie [ORNL

2013-01-01T23:59:59.000Z

467

Gas Bubble Trauma Monitoring and Research of Juvenile Salmonids, 1994-1995 Progress Report.  

DOE Green Energy (OSTI)

This report describes laboratory and field monitoring studies of gas bubble trauma (GBT) in migrating juvenile salmonids in the Snake and Columbia rivers. The first chapter describes laboratory studies of the progression of GBT signs leading to mortality and the use of the signs for GBT assessment. The progression and severity of GBT signs in juvenile salmonids exposed to different levels of total dissolved gas (TDG) and temperatures was assessed and quantified. Next, the prevalence, severity, and individual variation of GBT signs was evaluated to attempt to relate them to mortality. Finally, methods for gill examination in fish exposed to high TDG were developed and evaluated. Primary findings were: (1) no single sign of GBT was clearly correlated with mortality, but many GBT signs progressively worsened; (2) both prevalence and severity of GBT signs in several tissues is necessary; (3) bubbles in the lateral line were the earliest sign of GBT, showed progressive worsening, and had low individual variation but may develop poorly during chronic exposures; (4) fin bubbles had high prevalence, progressively worsened, and may be a persistent sign of GBT; and (5) gill bubbles appear to be the proximate cause of death but may only be relevant at high TDG levels and are difficult to examine. Chapter Two describes monitoring results of juvenile salmonids for signs of GBT. Emigrating fish were collected and examined for bubbles in fins and lateral lines. Preliminary findings were: (1) few fish had signs of GBT, but prevalence and severity appeared to increase as fish migrated downstream; (2) there was no apparent correlation between GBT signs in the fins, lateral line, or gills; (3) prevalence and severity of GBT was suggestive of long-term, non-lethal exposure to relatively low level gas supersaturated water; and (4) it appeared that GBT was not a threat to migrating juvenile salmonids. 24 refs., 26 figs., 3 tabs.

Hans, Karen M.

1997-07-01T23:59:59.000Z

468

Injection Molding of Tungsten Powder Treated by Jet Mill  

Science Conference Proceedings (OSTI)

Tungsten powder was firstly treated by jet mill, resulting in the improvement of ... and Welding Conditions of Monopile and Transition for Offshore Wind Plant.

469

Shattering Kraft Recovery Boiler Smelt by a Steam Jet.  

E-Print Network (OSTI)

??Kraft recovery boiler smelt is shattered into small droplets by an impinging steam jet to prevent smelt-water explosions in the dissolving tank. Inadequate shattering increases… (more)

Taranenko, Anton

2013-01-01T23:59:59.000Z

470

Simulations of Jets Driven by Black Hole Rotation  

E-Print Network (OSTI)

The origin of jets emitted from black holes is not well understood, however there are two possible energy sources, the accretion disk or the rotating black hole. Magnetohydrodynamic simulations show a well-defined jet that extracts energy from a black hole. If plasma near the black hole is threaded by large-scale magnetic flux, it will rotate with respect to asymptotic infinity creating large magnetic stresses. These stresses are released as a relativistic jet at the expense of black hole rotational energy. The physics of the jet initiation in the simulations is described by the theory of black hole gravitohydromagnetics.

Vladimir Semenov; Sergey Dyadechkin; Brian Punsly

2004-08-20T23:59:59.000Z

471

Electronic spectroscopy of jet-cooled combustion radicals. Final report  

Science Conference Proceedings (OSTI)

Jet-cooled spectra of 1-methylvinoxy and 2-methylvinoxy are reported and analyzed with help from high-level electronic structure calculations.

Weisshaar, James C.

2002-03-11T23:59:59.000Z

472

Relativistic Poynting-Flux Jets as Transmission Lines  

E-Print Network (OSTI)

Recent radio emission, polarization, and Faraday rotation maps of the radio jet of the galaxy 3C 303 have shown that one knot of this jet has a {\\it galactic}-scale electric current of $\\sim 3\\times 10^{18}$ Amp\\`ere flowing along the jet axis (Kronberg et al. 2011). We develop the theory of relativistic Poynting-flux jets which are modeled as a transmission line carrying a DC current $I_0$, having a potential drop $V_0$, and a definite impedance ${\\cal Z}_0 =90(u_z/c)\\Omega$, where $u_z$ is the bulk velocity of the jet plasma. The electromagnetic energy flow in the jet is ${\\cal Z}_0 I_0^2$. The observed current in 3C 303 can be used to calculate the electromagnetic energy flow in this magnetically dominated jet. Time-dependent but not necessarily small perturbations of a Poynting-flux jet - possibly triggered by a gas cloud penetrating the jet - are described by "telegrapher's equations," which predict the p