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1

ENGINEERING DEVELOPMENT OF SLURRY BUBBLE COLUMN REACTOR (SBCR) TECHNOLOGY  

SciTech Connect (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. Washington University's work during the reporting period involved the implementation of the automated calibration device, which will provide an advanced method of determining liquid and slurry velocities at high pressures. This new calibration device is intended to replace the original calibration setup, which depended on fishing lines and hooks to position the radioactive particle. The report submitted by Washington University contains a complete description of the new calibration device and its operation. Improvements to the calibration program are also discussed. Iowa State University utilized air-water bubble column simulations in an effort to determine the domain size needed to represent all of the flow scales in a gas-liquid column at a high superficial velocity. Ohio State's report summarizes conclusions drawn from the completion of gas injection phenomena studies, specifically with respect to the characteristics of bubbling-jetting at submerged single orifices in liquid-solid suspensions.

Bernard A. Toseland

2000-12-31T23:59:59.000Z

2

ENGINEERING DEVELOPMENT OF SLURRY BUBBLE COLUMN REACTOR (SBCR) TECHNOLOGY  

SciTech Connect (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 past three months of research have been focused on two major areas of bubble column hydrodynamics: (1) pressure and temperature effects on gas holdup and (2) region transition using a sparger as a gas distributor.

Bernard A. Toseland, Ph.D.

1999-03-01T23:59:59.000Z

3

Engineering Development of Slurry Bubble Column Reactor (SBCR) Technology  

SciTech Connect (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.

1998-10-29T23:59:59.000Z

4

ENGINEERING DEVELOPMENT OF SLURRY BUBBLE COLUMN REACTOR (SBCR) TECHNOLOGY  

SciTech Connect (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 rector 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

1998-06-30T23:59:59.000Z

5

Sound Waves Excitation by Jet-Inflated Bubbles in Clusters of Galaxies  

E-Print Network [OSTI]

We show that repeated sound waves in the intracluster medium (ICM) can be excited by a single inflation episode of an opposite bubble pair. To reproduce this behavior in numerical simulations the bubbles should be inflated by jets, rather than being injected artificially. The multiple sound waves are excited by the motion of the bubble-ICM boundary that is caused by vortices inside the inflated bubbles and the backflow (`cocoon') of the ICM around the bubble. These sound waves form a structure that can account for the ripples observed in the Perseus cooling flow cluster. We inflate the bubbles using slow massive jets, with either a wide opening angle or that are precessing. The jets are slow in the sense that they are highly sub-relativistic, $v_j \\sim 0.01c-0.1c$, and they are massive in the sense that the pair of bubbles carry back to the ICM a large fraction of the cooling mass, i.e., $\\sim 1-50 M_\\odot \\yr^{-1}$. We use a two-dimensional axisymmetric (referred to as 2.5D) hydrodynamical numerical code (VH-1).

Assaf Sternberg; Noam Soker

2008-08-17T23:59:59.000Z

6

Inflating Fat Bubbles in Clusters of Galaxies by Precessing Massive Slow Jets  

E-Print Network [OSTI]

We conduct hydrodynamical numerical simulations and find that precessing massive slow jets can inflate fat bubbles, i.e., more or less spherical bubbles, that are attached to the center of clusters of galaxies. To inflate a fat bubble the jet should precess fast. The precessing angle $\\theta$ should be large, or change over a large range $ 0 \\le \\theta \\le \\theta_{\\max} \\sim 30-70 ^\\circ$ (depending also on other parameters), where $\\theta=0$ is the symmetry axis. The constraints on the velocity and mass outflow rate are similar to those on wide jets to inflate fat bubbles. The velocity should be $v_j \\sim 10^4 \\kms$, and the mass loss rate of the two jets should be $ 2 \\dot M_j \\simeq 1-50 \\dot M_\\odot \\yr^{-1} $. These results, and our results from a previous paper dealing with slow wide jets, support the claim that a large fraction of the feedback heating in cooling flow clusters and in the processes of galaxy formation is done by slow massive jets.

Assaf Sternberg; Noam Soker

2008-01-09T23:59:59.000Z

7

Inflating Fat Bubbles in Clusters of Galaxies by Precessing Massive Slow Jets  

E-Print Network [OSTI]

We conduct hydrodynamical numerical simulations and find that precessing massive slow jets can inflate fat bubble, i.e., more or less spherical, attached to the center of clusters of galaxies. To inflate a fat bubble the jet should precess fast. The precessing angle $\\theta$ should be large, or change over a large range $ 0 \\le \\theta \\le \\theta_{\\max} \\sim 30-70 ^\\circ$ (depending also on other parameters), where $\\theta=0$ is the symmetry axis. The constraints on the velocity and mass outflow rate are similar to those on wide jets to inflate fat bubbles. The velocity should be $v_j \\sim 10^4 \\km \\s^{-1}$, and the mass loss rate of the two jets should be $ 2 \\dot M_j \\simeq 1-50 \\dot M_\\odot \\yr^{-1} $. These results and our results from a previous paper dealing with slow wide jets support the claim that a large fraction of the feedback heating in cooling flow clusters and in the processes of galaxy formation is done by slow massive jets.

Sternberg, Assaf

2007-01-01T23:59:59.000Z

8

COMPUTATIONAL AND EXPERIMENTAL MODELING OF SLURRY BUBBLE COLUMN REACTORS  

SciTech Connect (OSTI)

This project is a collaborative effort between the University of Akron, Illinois Institute of Technology and two industries: UOP and Energy International. The tasks involve the development of transient two and three dimensional computer codes for slurry bubble column reactors, optimization, comparison to data, and measurement of input parameters, such as the viscosity and restitution coefficients. To understand turbulence, measurements were done in the riser with 530 micron glass beads using a PIV technique. This report summarizes the measurements and simulations completed as described in details in the attached paper, ''Computational and Experimental Modeling of Three-Phase Slurry-Bubble Column Reactor.'' The Particle Image Velocimetry method described elsewhere (Gidaspow and Huilin, 1996) was used to measure the axial and tangential velocities of the particles. This method was modified with the use of a rotating colored transparent disk. The velocity distributions obtained with this method shows that the distribution is close to Maxwellian. From the velocity measurements the normal and the shear stresses were computed. Also with the use of the CCD camera a technique was developed to measure the solids volume fraction. The granular temperature profile follows the solids volume fraction profile. As predicted by theory, the granular temperature is highest at the center of the tube. The normal stress in the direction of the flow is approximately 10 times larger than that in the tangential direction. The <{nu}{prime}{sub z}{nu}{prime}{sub z}> is lower at the center where the <{nu}{prime}{sub {theta}}{nu}{prime}{sub {theta}}> is higher at that point. The Reynolds shear stress was small, producing a restitution coefficient near unity. The normal Reynolds stress in the direction of flow is large due to the fact that it is produced by the large gradient of velocity in the direction of flow compared to the small gradient in the {theta} and r directions. The kinetic theory gives values of viscosity that agree with our previous measurements (Gidaspow, Wu and Mostofi, 1999). The values of viscosity obtained from pressure drop minus weight of bed measurements agree at the center of the tube.

Paul Lam; Dimitri Gidaspow

2001-08-01T23:59:59.000Z

9

Recent Steps Towards a Controlled Thermonuclear Fusion Reactor with Results from the JET Tokamak Device  

E-Print Network [OSTI]

Recent Steps Towards a Controlled Thermonuclear Fusion Reactor with Results from the JET Tokamak Device

10

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

SciTech Connect (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

11

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

E-Print Network [OSTI]

process of a solar reformer of dry methane reforming was proposed to operate in a temperature range of 600SOLAR UPGRADE OF METHANE USING DRY REFORMING IN DIRECT CONTACT BUBBLE REACTOR Khalid Al-Ali 1 including lower melting point, thermal and chemical stability, acting simultaneously as heat transport

Paris-Sud XI, Université de

12

A Study of Vertical Gas Jets in a Bubbling Fluidized Bed  

SciTech Connect (OSTI)

A detailed experimental study of a vertical gas jet impinging a fluidized bed of particles has been conducted with the help of Laser Doppler Velocimetry measurements. Mean and fluctuating velocity profiles of the two phases have been presented and analyzed for different fluidization states of the emulsion. The results of this work would be greatly helpful in understanding the complex two-phase mixing phenomenon that occurs in bubbling beds, such as in coal and biomass gasification, and also in building more fundamental gas-solid Eulerian/Lagrangian models which can be incorporated into existing CFD codes. Relevant simulations to supplement the experimental findings have also been conducted using the Department of Energyâ??s open source code MFIX. The goal of these simulations was two-fold. One was to check the two-dimensional nature of the experimental results. The other was an attempt to improve the existing dense phase Eulerian framework through validation with the experimental results. In particular the sensitivity of existing frictional models in predicting the flow was investigated. The simulation results provide insight on wall-bounded turbulent jets and the effect frictional models have on gas-solid bubbling flows. Additionally, some empirical minimum fluidization correlations were validated for non-spherical particles with the idea of extending the present study to non-spherical particles which are more common in industries.

Steven Ceccio; Jennifer Curtis

2011-01-18T23:59:59.000Z

13

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

14

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

15

Progress in Understanding Low-Temperature Organic Compound Oxidation Using a Jet-Stirred Reactor  

E-Print Network [OSTI]

1 Progress in Understanding Low-Temperature Organic Compound Oxidation Using a Jet-Stirred Reactor Lorraine, CNRS, ENSIC, BP 20451, 1 rue Grandville, 54000 Nancy, France Abstract The jet-stirred reactor compounds that can be found in fuels and biofuels. Such an improvement in understanding requires

16

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

SciTech Connect (OSTI)

This report summarizes the accomplishment made during the third year of this cooperative research effort between Washington University, Ohio State University and Air Products and Chemicals. Data processing of the performed Computer Automated Radioactive Particle Tracking (CARPT) experiments in 6 inch column using air-water-glass beads (150 {micro}m) system has been completed. Experimental investigation of time averaged three phases distribution in air-Therminol LT-glass beads (150 {micro}m) system in 6 inch column has been executed. Data processing and analysis of all the performed Computed Tomography (CT) experiments have been completed, using the newly proposed CT/Overall gas holdup methodology. The hydrodynamics of air-Norpar 15-glass beads (150 {micro}m) have been investigated in 2 inch slurry bubble column using Dynamic Gas Disengagement (DGD), Pressure Drop fluctuations, and Fiber Optic Probe. To improve the design and scale-up of bubble column reactors, a correlation for overall gas holdup has been proposed based on Artificial Neural Network and Dimensional Analysis.

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

2002-07-25T23:59:59.000Z

17

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

SciTech Connect (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

18

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

19

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

20

Analysis of reactor material experiments investigating corium crust stability and heat transfer in jet impingement flow  

SciTech Connect (OSTI)

Presented is an analysis of the results of the CSTI-1, CSTI-3, and CWTI-11 reactor material experiments in which a jet of molten corium initially at 3080/sup 0/K was directed downward upon a stainless steel plate. The experiments are a continuation of a program of reactor material tests investigating LWR severe accident phenomena. Objective of the present analysis is to determine the existence or nonexistence of a corium crust during impingement from comparison of the measured heatup of the plate (as measured by thermocouples imbedded immediately beneath the steel surface) with model calculations assuming alternately the presence and absence of a stable crust during impingement.

Sienicki, J.J.; Spencer, B.W.

1985-01-01T23:59:59.000Z

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.


21

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

22

Dynamic Modeling and Control Studies of a Two-Stage Bubbling Fluidized Bed Adsorber-Reactor for Solid-Sorbent CO{sub 2} Capture  

SciTech Connect (OSTI)

A one-dimensional, non-isothermal, pressure-driven dynamic model has been developed for a two-stage bubbling fluidized bed (BFB) adsorber-reactor for solid-sorbent carbon dioxide (CO{sub 2}) capture using Aspen Custom Modeler® (ACM). The BFB model for the flow of gas through a continuous phase of downward moving solids considers three regions: emulsion, bubble, and cloud-wake. Both the upper and lower reactor stages are of overflow-type configuration, i.e., the solids leave from the top of each stage. In addition, dynamic models have been developed for the downcomer that transfers solids between the stages and the exit hopper that removes solids from the bottom of the bed. The models of all auxiliary equipment such as valves and gas distributor have been integrated with the main model of the two-stage adsorber reactor. Using the developed dynamic model, the transient responses of various process variables such as CO{sub 2} capture rate and flue gas outlet temperatures have been studied by simulating typical disturbances such as change in the temperature, flowrate, and composition of the incoming flue gas from pulverized coal-fired power plants. In control studies, the performance of a proportional-integral-derivative (PID) controller, feedback-augmented feedforward controller, and linear model predictive controller (LMPC) are evaluated for maintaining the overall CO{sub 2} capture rate at a desired level in the face of typical disturbances.

Modekurti, Srinivasarao; Bhattacharyya, Debangsu; Zitney, Stephen E.

2013-07-31T23:59:59.000Z

23

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  

SciTech Connect (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

24

First operation with the JET International Thermonuclear Experimental Reactor-like wall  

SciTech Connect (OSTI)

To consolidate International Thermonuclear Experimental Reactor (ITER) design choices and prepare for its operation, Joint European Torus (JET) has implemented ITER's plasma facing materials, namely, Be for the main wall and W in the divertor. In addition, protection systems, diagnostics, and the vertical stability control were upgraded and the heating capability of the neutral beams was increased to over 30 MW. First results confirm the expected benefits and the limitations of all metal plasma facing components (PFCs) but also yield understanding of operational issues directly relating to ITER. H-retention is lower by at least a factor of 10 in all operational scenarios compared to that with C PFCs. The lower C content (? factor 10) has led to much lower radiation during the plasma burn-through phase eliminating breakdown failures. Similarly, the intrinsic radiation observed during disruptions is very low, leading to high power loads and to a slow current quench. Massive gas injection using a D{sub 2}/Ar mixture restores levels of radiation and vessel forces similar to those of mitigated disruptions with the C wall. Dedicated L-H transition experiments indicate a 30% power threshold reduction, a distinct minimum density, and a pronounced shape dependence. The L-mode density limit was found to be up to 30% higher than for C allowing stable detached divertor operation over a larger density range. Stable H-modes as well as the hybrid scenario could be re-established only when using gas puff levels of a few 10{sup 21} es{sup ?1}. On average, the confinement is lower with the new PFCs, but nevertheless, H factors up to 1 (H-Mode) and 1.3 (at ?{sub N}?3, hybrids) have been achieved with W concentrations well below the maximum acceptable level.

Neu, R. [EFDA-CSU, Boltzmannstr. 2, 85748 Garching (Germany) [EFDA-CSU, Boltzmannstr. 2, 85748 Garching (Germany); Max-Planck-Institut für Plasmaphysik, Euratom Association, Boltzmannstr. 2, 85748 Garching (Germany); Arnoux, G.; Beurskens, M.; Challis, C.; Giroud, C.; Lomas, P.; Maddison, G.; Matthews, G.; Mayoral, M.-L.; Meigs, A.; Rimini, F. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)] [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Bobkov, V.; Dux, R.; Hobirk, J.; Lang, P.; Maggi, C.; Pütterich, T.; Sertoli, M.; Sieglin, B. [Max-Planck-Institut für Plasmaphysik, Euratom Association, Boltzmannstr. 2, 85748 Garching (Germany)] [Max-Planck-Institut für Plasmaphysik, Euratom Association, Boltzmannstr. 2, 85748 Garching (Germany); Brezinsek, S. [IEK-4, Association EURATOM/Forschungszentrum Jülich GmbH, Jülich 52425 (Germany)] [IEK-4, Association EURATOM/Forschungszentrum Jülich GmbH, Jülich 52425 (Germany); and others

2013-05-15T23:59:59.000Z

25

Bubbling bed catalytic hydropyrolysis process utilizing larger catalyst particles and smaller biomass particles featuring an anti-slugging reactor  

SciTech Connect (OSTI)

This invention relates to a process for thermochemically transforming biomass or other oxygenated feedstocks into high quality liquid hydrocarbon fuels. In particular, a catalytic hydropyrolysis reactor, containing a deep bed of fluidized catalyst particles is utilized to accept particles of biomass or other oxygenated feedstocks that are significantly smaller than the particles of catalyst in the fluidized bed. The reactor features an insert or other structure disposed within the reactor vessel that inhibits slugging of the bed and thereby minimizes attrition of the catalyst. Within the bed, the biomass feedstock is converted into a vapor-phase product, containing hydrocarbon molecules and other process vapors, and an entrained solid char product, which is separated from the vapor stream after the vapor stream has been exhausted from the top of the reactor. When the product vapor stream is cooled to ambient temperatures, a significant proportion of the hydrocarbons in the product vapor stream can be recovered as a liquid stream of hydrophobic hydrocarbons, with properties consistent with those of gasoline, kerosene, and diesel fuel. Separate streams of gasoline, kerosene, and diesel fuel may also be obtained, either via selective condensation of each type of fuel, or via later distillation of the combined hydrocarbon liquid.

Marker, Terry L; Felix, Larry G; Linck, Martin B; Roberts, Michael J

2014-09-23T23:59:59.000Z

26

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

SciTech Connect (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

27

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

SciTech Connect (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

28

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

SciTech Connect (OSTI)

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

29

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

30

Analysis of reactor material experiments investigating oxide fuel crust stability and heat transfer in jet impingement flow  

SciTech Connect (OSTI)

An analysis is presented of the crust stability and heat transfer behavior in the CSTI-1, CSTI-3, and CWTI-11 reactor material experiments in which a jet of molten oxide fuel at approx. 160/sup 0/K above its freezing temperature was impinged normally upon stainless steel plates initially at 300 and 385 K. The major issue is the existence of nonexistence of a stable solidified layer of fuel, or crust, interstitial to the flowing hot fuel and the steel substrate, tending to insulate the steel from the hot molten fuel. A computer model was developed to predict the heatup of thermocouples imbedded immediately beneath the surface of the plate for both of the cases in which a stable crust is assumed to be either present or absent during the impingement phase. Comparison of the model calculations with the measured thermocouple temperatures indicates that a protective crust was present over nearly all of the plate surface area throughout the impingement process precluding major melting of the plate steel. However, the experiments also show evidence for very localized and isolated steel melting as revealed by localized and isolated pitting of the steel surface and the response of thermocouples located within the pitted region.

Sienicki, J.J.; Spencer, B.W.

1985-01-01T23:59:59.000Z

31

Measurement and modeling of Ar/H2/CH4 arc jet discharge chemical vapor deposition reactors. I. Intercomparison  

E-Print Network [OSTI]

of thin, polycrystalline diamond films, and the results of a two-dimensional r,z computer model domains. dc arc jets offer considerable advantages as a route to deposition of polycrystalline diamond

Bristol, University of

32

Giant bubble pinch-off  

E-Print Network [OSTI]

Self-similarity has been the paradigmatic picture for the pinch-off of a drop. Here we will show through high-speed imaging and boundary integral simulations that the inverse problem, the pinch-off of an air bubble in water, is not self-similar in a strict sense: A disk is quickly pulled through a water surface, leading to a giant, cylindrical void which after collapse creates an upward and a downward jet. Only in the limiting case of large Froude number the neck radius $h$ scales as $h(-\\log h)^{1/4} \\propto \\tau^{1/2}$, the purely inertial scaling. For any finite Froude number the collapse is slower, and a second length-scale, the curvature of the void, comes into play. Both length-scales are found to exhibit power-law scaling in time, but with different exponents depending on the Froude number, signaling the non-universality of the bubble pinch-off.

Raymond Bergmann; Devaraj van der Meer; Mark Stijnman; Marijn Sandtke; Andrea Prosperetti; Detlef Lohse

2006-01-24T23:59:59.000Z

33

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

34

Rotating bubble membrane radiator  

DOE Patents [OSTI]

A heat radiator useful for expelling waste heat from a power generating system aboard a space vehicle is disclosed. Liquid to be cooled is passed to the interior of a rotating bubble membrane radiator, where it is sprayed into the interior of the bubble. Liquid impacting upon the interior surface of the bubble is cooled and the heat radiated from the outer surface of the membrane. Cooled liquid is collected by the action of centrifical force about the equator of the rotating membrane and returned to the power system. Details regarding a complete space power system employing the radiator are given.

Webb, Brent J. (West Richland, WA); Coomes, Edmund P. (West Richland, WA)

1988-12-06T23:59:59.000Z

35

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

36

Modeling of Taylor bubble rising in a vertical mini noncircular channel filled with a stagnant liquid  

E-Print Network [OSTI]

of the liquid phase coupled with the equations of the force balance at the bubble interface. The predicted drift by the interfacial curvature variations along bubble length, gravity, and viscous force. The interfacial profiles gas reservoir during gas production, in chemical and nuclear reactors, and numerous heat transport

Zhao, Tianshou

37

Heating the bubbly gas of galaxy clusters with weak shocks and sound waves  

E-Print Network [OSTI]

Using hydrodynamic simulations and a technique to extract the rotational component of the velocity field, we show how bubbles of relativistic gas inflated by AGN jets in galaxy clusters act as a catalyst, transforming the energy carried by sound and shock waves to heat. The energy is stored in a vortex field around the bubbles which can subsequently be dissipated. The efficiency of this process is set mainly by the fraction of the cluster volume filled by (sub-)kpc scale filaments and bubbles of relativistic plasma.

S. Heinz; E. Churazov

2005-09-26T23:59:59.000Z

38

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

39

Quantum Subcritical Bubbles  

E-Print Network [OSTI]

We quantize subcritical bubbles which are formed in the weakly first order phase transition. We find that the typical size of the thermal fluctuation reduces in the quantum-statistical physics. We estimate the typical size and the amplitude of thermal fluctuations near the critical temperature in the electroweak phase transition using quantum statistical average. Furthermore based on our study, we give implication on the dynamics of phase transition.

Tomoko Uesugi; Masahiro Morikawa; Tetsuya Shiromizu

1996-06-26T23:59:59.000Z

40

Measurement and modeling of Ar/H2/CH4 arc jet discharge chemical vapor deposition reactors II: Modeling of the spatial dependence of expanded  

E-Print Network [OSTI]

and used to deposit thin films of polycrystalline diamond. This reactor has been the subject of many prior of micro- and nanocrystalline diamond and diamondlike carbon films. The model incorporates gas activation-containing radical species incident on the growing diamond surface C atoms and CH radicals within this reactor

Bristol, University of

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

Neutrino Factory / Muon Collider Target Meeting Numerical Simulations for Jet-Proton  

E-Print Network [OSTI]

breakup observed in simulations Mercury is able to sustain very large tension Jet oscillates after on the surface of a hydrofoil Pressure contour in mercury target. #12;13 The Bubble Insertion Model Numerical

McDonald, Kirk

42

Helium bubble bursting in tungsten  

SciTech Connect (OSTI)

Molecular dynamics simulations have been used to systematically study the pressure evolution and bursting behavior of sub-surface helium bubbles and the resulting tungsten surface morphology. This study specifically investigates how bubble shape and size, temperature, tungsten surface orientation, and ligament thickness above the bubble influence bubble stability and surface evolution. The tungsten surface is roughened by a combination of adatom “islands,” craters, and pinholes. The present study provides insight into the mechanisms and conditions leading to various tungsten topology changes, which we believe are the initial stages of surface evolution leading to the formation of nanoscale fuzz.

Sefta, Faiza [University of California, Berkeley, California 94720 (United States); Juslin, Niklas [University of Tennessee, Knoxville, Tennessee 37996 (United States); Wirth, Brian D., E-mail: bdwirth@utk.edu [University of Tennessee, Oak Ridge National Laboratory, Knoxville, Tennessee 37996 (United States)

2013-12-28T23:59:59.000Z

43

Prevention of tissue damage by water jet during cavitation Daniel Palanker,a)  

E-Print Network [OSTI]

Prevention of tissue damage by water jet during cavitation Daniel Palanker,a) Alexander Vankov Cavitation bubbles accompany explosive vaporization of water following pulsed energy deposition in liquid can produce tissue damage at a distance exceeding the radius of the cavitation bubble by a factor of 4

Palanker, Daniel

44

Microfluidic Actuation Using Electrochemically Generated Bubbles  

E-Print Network [OSTI]

Microfluidic Actuation Using Electrochemically Generated Bubbles Susan Z. Hua,*, Frederick Sachs, Buffalo, New York 14260 Bubble-based actuation in microfluidic applications is attractive owing closing) rate increases with applied voltage, small microfluidic dimensions accelerate bubble deflation

Sachs, Frederick

45

A prediction for bubbling geometries  

E-Print Network [OSTI]

We study the supersymmetric circular Wilson loops in N=4 Yang-Mills theory. Their vacuum expectation values are computed in the parameter region that admits smooth bubbling geometry duals. The results are a prediction for the supergravity action evaluated on the bubbling geometries for Wilson loops.

Takuya Okuda

2008-02-11T23:59:59.000Z

46

Modeling air entrainment in plunging jet using 3DYNAFS  

E-Print Network [OSTI]

As the liquid jet plunges into a free surface, significant air is entrained into the water and forms air pockets. These air pockets eventually break up into small bubbles, which travel downstream to form a bubbly wake. To better understand the underlying flow physics involved in the bubble entrainment, in the linked videos, air entrainment due to a water jet plunging onto a pool of stationary water was numerically studied by using the 3DYNAFS software suit. The flow field is simulated by directly solving the Navier-Stokes equations through the viscous module, 3DYNAFS-VIS, using a level set method for capturing the free surface. The breakup of entrained air pockets and the resulting bubbly flow were modeled by coupling 3DYNAFS-VIS with a Lagrangian multi-bubble tracking model, 3DYNAFS-DSM (Hsiao & Chahine, 2003), which emits bubbles into the liquid according to local liquid/gas interface flow conditions based on the sub-grid air entrainment modeling proposed by Ma et al. (2011), and tracks all bubbles in t...

Hsiao, Chao-Tsung; Wu, Xiongjun; Chahine, Georges L

2011-01-01T23:59:59.000Z

47

Astrophysical Jets  

SciTech Connect (OSTI)

Many astrophysical sources - especially those powered by release of gravitational energy - are associated with an outflow of material, generally taking place along the axis of symmetry of the system. In the most extreme cases, the outflow is accelerated to relativistic speeds; such a phenomenon is known as an astrophysical jet. When a relativistic jet points close to our line of sight, the observed radiation is strongly Doppler-boosted. Most spectacular cases of astrophysical jets are those produced by active galactic nuclei, where the measured spectrum - presumably dominated by the radiation from the jet - reaches up to the multi-GeV range. Our knowledge of these jets is limited: we don't fully understand how are they formed, collimated, and accelerated, and what is the process of conversion of the bulk energy of the jet into radiation. We anticipate that the increased sensitivity of GLAST will provide us with spectacular data yielding new insights as to their origin and structure.

Madejski, Grzegorz (SLAC) [SLAC

2006-05-01T23:59:59.000Z

48

Stellar jets  

E-Print Network [OSTI]

With a goal of understanding the conditions under which jets might be produced in novae and related objects, I consider the conditions under which jets are produced from other classes of accreting compact objects. I give an overview of accretion disk spectral states, including a discussion of in which states these jets are seen. I highlight the differences between neutron stars and black holes, which may help give us insights about when and how the presence of a solid surface may help or inhibit jet production.

Thomas J. Maccarone

2008-05-23T23:59:59.000Z

49

Experimental investigation of bubbling in particle beds with high solid holdup  

SciTech Connect (OSTI)

A series of experiments on bubbling behavior in particle beds was performed to clarify three-phase flow dynamics in debris beds formed after core-disruptive accident (CDA) in sodium-cooled fast breeder reactors (FBRs). Although in the past, several experiments have been performed in packed beds to investigate flow patterns, most of these were under comparatively higher gas flow rate, which may be not expected during an early sodium boiling period in debris beds. The current experiments were conducted under two dimensional (2D) and three dimensional (3D) conditions separately, in which water was used as liquid phase, and bubbles were generated by injecting nitrogen gas from the bottom of the viewing tank. Various particle-bed parameters were varied, including particle-bed height (from 30 mm to 200 mm), particle diameter (from 0.4 mm to 6 mm) and particle type (beads made of acrylic, glass, alumina and zirconia). Under these experimental conditions, three kinds of bubbling behavior were observed for the first time using digital image analysis methods that were further verified by quantitative detailed analysis of bubbling properties including surface bubbling frequency and surface bubble size under both 2D and 3D conditions. This investigation, which hopefully provides fundamental data for a better understanding and an improved estimation of CDAs in FBRs, is expected to benefit future analysis and verification of computer models developed in advanced fast reactor safety analysis codes. (author)

Cheng, Songbai; Hirahara, Daisuke; Tanaka, Youhei; Gondai, Yoji; Zhang, Bin; Matsumoto, Tatsuya; Morita, Koji; Fukuda, Kenji [Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395 (Japan); Yamano, Hidemasa; Suzuki, Tohru; Tobita, Yoshiharu [Advanced Nuclear System R and D Directorate, Japan Atomic Energy Agency, 4002 Narita, O-arai, Ibaraki 311-1393 (Japan)

2011-02-15T23:59:59.000Z

50

Cavitation bubble behavior inside a liquid jet Etienne Robert,1,  

E-Print Network [OSTI]

Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland 2 European Organization for Nuclear a 60 Hz is impinging on a flowing mercury target confined in a stainless steel tube. Preliminary test- ing have shown pitting erosion on the target vessel which limits its service lifetime. It is thought

McDonald, Kirk

51

Emerging Jets  

E-Print Network [OSTI]

In this work, we propose a novel search strategy for new physics at the LHC that utilizes calorimeter jets that (i) are composed dominantly of displaced tracks and (ii) have many different vertices within the jet cone. Such emerging jet signatures are smoking guns for models with a composite dark sector where a parton shower in the dark sector is followed by displaced decays of dark pions back to SM jets. No current LHC searches are sensitive to this type of phenomenology. We perform a detailed simulation for a benchmark signal with two regular and two emerging jets, and present and implement strategies to suppress QCD backgrounds by up to six orders of magnitude. At the 14 TeV LHC, this signature can be probed with mediator masses as large as 1.5 TeV for a range of dark pion lifetimes, and the reach is increased further at the high-luminosity LHC. The emerging jet search is also sensitive to a broad class of long-lived phenomena, and we show this for a supersymmetric model with R-parity violation. Possibilities for discovery at LHCb are also discussed.

Pedro Schwaller; Daniel Stolarski; Andreas Weiler

2015-02-24T23:59:59.000Z

52

Emerging Jets  

E-Print Network [OSTI]

In this work, we propose a novel search strategy for new physics at the LHC that utilizes calorimeter jets that (i) are composed dominantly of displaced tracks and (ii) have many different vertices within the jet cone. Such emerging jet signatures are smoking guns for models with a composite dark sector where a parton shower in the dark sector is followed by displaced decays of dark pions back to SM jets. No current LHC searches are sensitive to this type of phenomenology. We perform a detailed simulation for a benchmark signal with two regular and two emerging jets, and present and implement strategies to suppress QCD backgrounds by up to six orders of magnitude. At the 14 TeV LHC, this signature can be probed with mediator masses as large as 1.5 TeV for a range of dark pion lifetimes, and the reach is increased further at the high-luminosity LHC. The emerging jet search is also sensitive to a broad class of long-lived phenomena, and we show this for a supersymmetric model with R-parity violation. Possibilit...

Schwaller, Pedro; Weiler, Andreas

2015-01-01T23:59:59.000Z

53

Interactions of a Light Hypersonic Jet with a Non-Uniform Interstellar Medium  

E-Print Network [OSTI]

We present three dimensional simulations of the interaction of a light hypersonic jet with an inhomogeneous thermal and turbulently supported disk in an elliptical galaxy. We model the jet as a light, supersonic non-relativistic flow with parameters selected to be consistent with a relativistic jet with kinetic power just above the FR1/FR2 break. We identify four generic phases in the evolution of such a jet with the inhomogeneous interstellar medium: 1) an initial ``flood and channel'' phase, where progress is characterized by high pressure gas finding changing weak points in the ISM, flowing through channels that form and re-form over time, 2) a spherical, energy-driven bubble phase, were the bubble is larger than the disk scale, but the jet remains fully disrupted close to the nucleus, 3) a rapid, jet break--out phase the where jet breaks free of the last dense clouds, becomes collimated and pierces the spherical bubble, and 4) a classical phase, the jet propagates in a momentum-dominated fashion leading to the classical jet + cocoon + bow-shock structure. Mass transport in the simulations is investigated, and we propose a model for the morphology and component proper motions in the well-studied Compact Symmetric Object 4C31.04.

R. S. Sutherland; G. V. Bicknell

2007-07-25T23:59:59.000Z

54

Gas-bubble growth mechanisms in the analysis of metal fuel swelling  

SciTech Connect (OSTI)

During steady-state irradiation, swelling rates associated with growth of fission-gas bubbles in metallic fast reactor fuels may be expected to remain small. As a consequence, bubble-growth mechanisms are not a major consideration in modeling the steady-state fuel behavior, and it is usually adequate to consider the gas pressure to be in equilibrium with the external pressure and surface tension restraint. On transient time scales, however, various bubble-growth mechanisms become important components of the swelling rate. These mechanisms include growth by diffusion, for bubbles within grains and on grain boundaries; dislocation nucleation at the bubble surface, or ''punchout''; and bubble growth by creep. Analyses of these mechanisms are presented and applied to provide information on the conditions and the relative time scales for which the various processes should dominate fuel swelling. The results are compared to a series of experiments in which the swelling of irradiated metal fuel was determined after annealing at various temperatures and pressures. The diffusive growth of bubbles on grain boundaries is concluded to be dominant in these experiments.

Gruber, E.E.; Kramer, J.M.

1986-06-01T23:59:59.000Z

55

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

56

Bubble formation in Rangely Field, Colorado  

E-Print Network [OSTI]

tc Determine the Effect of Times Of. Standing on Time &equired for Bubble Formation at 67 psi Supersaturaticns. Page 20 Tests to Determine Bubble Frequency. Average Bubble Frequency Data. 23 27 The data reported in this thesis deal... if present, or would tend to form one. However, as the pressure on the saturated oil declines, the oil becomes supersatur- ated, except as bubbles may form and diffusion take place tc eliminate the supersaturation. This research is devoted to a study...

Wood, J. W

1953-01-01T23:59:59.000Z

57

Active microuidic mixer and gas bubble lter driven by thermal bubble micropump$  

E-Print Network [OSTI]

to be proportional to the one-third power of the input pulse frequency. Furthermore, a gas bubble ®lter is integratedActive micro¯uidic mixer and gas bubble ®lter driven by thermal bubble micropump$ Jr-Hung Tsaia Abstract A micro¯uidic mixer with a gas bubble ®lter activated by a thermal bubble actuated nozzle

Lin, Liwei

58

Interactions of a Light Hypersonic Jet with a Non-Uniform Interstellar Medium  

E-Print Network [OSTI]

We present three dimensional simulations of the interaction of a light hypersonic jet with an inhomogeneous thermal and turbulently supported disk in an elliptical galaxy. We model the jet as a light, supersonic non-relativistic flow with parameters selected to be consistent with a relativistic jet with kinetic power just above the FR1/FR2 break. We identify four generic phases in the evolution of such a jet with the inhomogeneous interstellar medium: 1) an initial ``flood and channel'' phase, where progress is characterized by high pressure gas finding changing weak points in the ISM, flowing through channels that form and re-form over time, 2) a spherical, energy-driven bubble phase, were the bubble is larger than the disk scale, but the jet remains fully disrupted close to the nucleus, 3) a rapid, jet break--out phase the where jet breaks free of the last dense clouds, becomes collimated and pierces the spherical bubble, and 4) a classical phase, the jet propagates in a momentum-dominated fashion leading t...

Sutherland, R S

2007-01-01T23:59:59.000Z

59

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

2014-12-26T23:59:59.000Z

60

Tiny Bubbles in my BEC  

SciTech Connect (OSTI)

Ultracold atomic gases provide a unique way for exploring many-body quantum phenomena that are inaccessible to conventional low-temperature experiments. Nearly two decades ago the Bose-Einstein condensate (BEC) - an ultracold gas of bosons in which almost all bosons occupy the same single-particle state - became experimentally feasible. Because a BEC exhibits superfluid properties, it can provide insights into the behavior of low-temperature helium liquids. We describe the case of a single distinguishable atom (an impurity) embedded in a BEC and strongly coupled to the BEC bosons. Depending on the strength of impurity-boson and boson-boson interactions, the impurity self-localizes into two fundamentally distinct regimes. The impurity atom can behave as a tightly localized 'polaron,' akin to an electron in a dielectric crystal, or as a 'bubble,' an analog to an electron bubble in superfluid helium. We obtain the ground state wavefunctions of the impurity and BEC by numerically solving the two coupled Gross-Pitaevskii equations that characterize the system. We employ the methods of imaginary time propagation and conjugate gradient descent. By appropriately varying the impurity-boson and boson-boson interaction strengths, we focus on the polaron to bubble crossover. Our results confirm analytical predictions for the polaron limit and uncover properties of the bubble regime. With these results we characterize the polaron to bubble crossover. We also summarize our findings in a phase diagram of the BEC-impurity system, which can be used as a guide in future experiments.

Blinova, Alina A. [Los Alamos National Laboratory

2012-08-01T23:59:59.000Z

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.


61

Collapse of Kaluza-Klein Bubbles  

E-Print Network [OSTI]

Kaluza-Klein theory admits ``bubble" configurations, in which the circumference of the fifth dimension shrinks to zero on some compact surface. A three parameter family of such bubble initial data at a moment of time-symmetry (some including a magnetic field) has been found by Brill and Horowitz, generalizing the (zero-energy) ``Witten bubble" solution. Some of these data have negative total energy. We show here that all the negative energy bubble solutions start out expanding away from the moment of time symmetry, while the positive energy bubbles can start out either expanding or contracting. Thus it is unlikely that the negative energy bubbles would collapse and produce a naked singularity.

Steven Corley; Ted Jacobson

1994-03-09T23:59:59.000Z

62

Bremsstrahlung Radiation At a Vacuum Bubble Wall  

E-Print Network [OSTI]

When charged particles collide with a vacuum bubble, they can radiate strong electromagnetic waves due to rapid deceleration. Owing to the energy loss of the particles by this bremsstrahlung radiation, there is a non-negligible damping pressure acting on the bubble wall even when thermal equilibrium is maintained. In the non-relativistic region, this pressure is proportional to the velocity of the wall and could have influenced the bubble dynamics in the early universe.

Jae-Weon Lee; Kyungsub Kim; Chul H. Lee; Ji-ho Jang

2007-04-06T23:59:59.000Z

63

E-Print Network 3.0 - ajustable para reactores Sample Search...  

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

Summary: diagnostic measurements of acetylene absorption in hot-filament and DC-arc plasma jet reactors operating... deposition. The acetylene was widely4 2 distributed...

64

Modeling the influence of bubble pressure on grain boundary separation and fission gas release  

SciTech Connect (OSTI)

Grain boundary (GB) separation as a mechanism for fission gas release (FGR), complementary to gas bubble interlinkage, has been experimentally observed in irradiated light water reactor fuel. However there has been limited effort to develop physics-based models incorporating this mechanism for the analysis of FGR. In this work, a computational study is carried out to investigate GB separation in UO2 fuel under the effect of gas bubble pressure and hydrostatic stress. A non-dimensional stress intensity factor formula is obtained through 2D axisymmetric analyses considering lenticular bubbles and Mode-I crack growth. The obtained functional form can be used in higher length-scale models to estimate the contribution of GB separation to FGR.

Pritam Chakraborty; Michael R. Tonks; Giovanni Pastore

2014-09-01T23:59:59.000Z

65

The impact of bubble diffusivity on confined oscillated bubbly liquid Sergey Shklyaev1  

E-Print Network [OSTI]

their volume. In other words, in a liquid containing bubbles the speed of sound cb can b oscillations4,5 to the frequency of external driving. Here, k= /c0 is the wave number, c0 is the speed of soundThe impact of bubble diffusivity on confined oscillated bubbly liquid Sergey Shklyaev1 and Arthur V

Straube, Arthur V.

66

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

67

The incorporation of bubbles into a computer graphics fluid simulation  

E-Print Network [OSTI]

We present methods for incorporating bubbles into a photorealistc fluid simulation. Previous methods of fluid simulation in computer graphics do not include bubbles. Our system automatically creates bubbles, which are simulated on top of the fluid...

Greenwood, Shannon Thomas

2005-08-29T23:59:59.000Z

68

A hot bubble at the centre of M81  

E-Print Network [OSTI]

Context. Messier 81 has the nearest active nucleus with broad H$\\alpha$ emission. A detailed study of this galaxy's centre is important for understanding the innermost structure of the AGN phenomenon. Aims. Our goal is to seek previously undetected structures using additional techniques to reanalyse a data cube obtained with the GMOS-IFU installed on the Gemini North telescope (Schnorr M\\"uller et al. 2011). Method. We analysed the data cube using techniques of noise reduction, spatial deconvolution, starlight subtraction, PCA tomography, and comparison with HST images. Results. We identified a hot bubble with T $>$ 43500 K that is associated with strong emission of [N II]$\\lambda$5755\\AA\\ and a high [O I]$\\lambda$6300/H$\\alpha$ ratio; the bubble displays a bluish continuum, surrounded by a thin shell of H$\\alpha$ + [N II] emission. We also reinterpret the outflow found by Schnorr M\\"uller et al. (2011) showing that the blueshifted cone nearly coincides with the radio jet, as expected. Conclusions. We interpr...

Ricci, T V; Giansante, L

2015-01-01T23:59:59.000Z

69

Inclusive Jets in PHP  

E-Print Network [OSTI]

Differential inclusive-jet cross sections have been measured in photoproduction for boson virtualities Q^2 < 1 GeV^2 with the ZEUS detector at HERA using an integrated luminosity of 300 pb^-1. Jets were identified in the laboratory frame using the k_T, anti-k_T or SIScone jet algorithms. Cross sections are presented as functions of the jet pseudorapidity, eta(jet), and the jet transverse energy, E_T(jet). Next-to-leading-order QCD calculations give a good description of the measurements, except for jets with low E_T(jet) and high eta(jet). The cross sections have the potential to improve the determination of the PDFs in future QCD fits. Values of alpha_s(M_Z) have been extracted from the measurements based on different jet algorithms. In addition, the energy-scale dependence of the strong coupling was determined.

Roloff, Philipp

2013-01-01T23:59:59.000Z

70

Inclusive Jets in PHP  

E-Print Network [OSTI]

Differential inclusive-jet cross sections have been measured in photoproduction for boson virtualities Q^2 < 1 GeV^2 with the ZEUS detector at HERA using an integrated luminosity of 300 pb^-1. Jets were identified in the laboratory frame using the k_T, anti-k_T or SIScone jet algorithms. Cross sections are presented as functions of the jet pseudorapidity, eta(jet), and the jet transverse energy, E_T(jet). Next-to-leading-order QCD calculations give a good description of the measurements, except for jets with low E_T(jet) and high eta(jet). The cross sections have the potential to improve the determination of the PDFs in future QCD fits. Values of alpha_s(M_Z) have been extracted from the measurements based on different jet algorithms. In addition, the energy-scale dependence of the strong coupling was determined.

Philipp Roloff

2013-10-23T23:59:59.000Z

71

ARTIGO INTERNET Professores visitam o maior reactor de Fuso Nuclear  

E-Print Network [OSTI]

ARTIGO INTERNET Professores visitam o maior reactor de Fusão Nuclear in http reactor de Fusão Nuclear Experiência aproxima investigação das futuras gerações Doze professores do ensino secundário visitaram o maior reactor de fusão nuclear da Terra (JET), no Reino Unido, na semana passada

Instituto de Sistemas e Robotica

72

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

73

Hydrogen Bubbles and Formation of Nanoporous Silicon during Electroche...  

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

Bubbles and Formation of Nanoporous Silicon during Electrochemical Etching. Hydrogen Bubbles and Formation of Nanoporous Silicon during Electrochemical Etching. Abstract: Many...

74

Oscillating plasma bubbles. II. Pulsed experiments  

SciTech Connect (OSTI)

Time-dependent phenomena have been investigated in plasma bubbles which are created by inserting spherical grids into an ambient plasma and letting electrons and ions form a plasma of different parameters than the ambient one. There are no plasma sources inside the bubble. The grid bias controls the particle flux. There are sheaths on both sides of the grid, each of which passes particle flows in both directions. The inner sheath or plasma potential develops self consistently to establish charge neutrality and divergence free charge and mass flows. When the electron supply is restricted, the inner sheath exhibits oscillations near the ion plasma frequency. When all electrons are excluded, a virtual anode forms on the inside sheath, reflects all ions such that the bubble is empty. By pulsing the ambient plasma, the lifetime of the bubble plasma has been measured. In an afterglow, plasma electrons are trapped inside the bubble and the bubble decays as slow as the ambient plasma. Pulsing the grid voltage yields the time scale for filling and emptying the bubble. Probes have been shown to modify the plasma potential. Using pulsed probes, transient ringing on the time scale of ion transit times through the bubble has been observed. The start of sheath oscillations has been investigated. The instability mechanism has been qualitatively explained. The dependence of the oscillation frequency on electrons in the sheath has been clarified.

Stenzel, R. L.; Urrutia, J. M. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States)

2012-08-15T23:59:59.000Z

75

Gas bubble dynamics in soft materials  

E-Print Network [OSTI]

Epstein and Plesset's seminal work on the rate of gas bubble dissolution and growth in a simple liquid is generalized to render it applicable to a gas bubble embedded in a soft elastic medium. Both the underlying diffusion equation and the expression for the gas bubble pressure were modified to allow for the non-zero shear modulus of the elastic medium. The extension of the diffusion equation results in a trivial shift (by an additive constant) in the value of the diffusion coefficient, and does not change the form of the rate equations. But the use of a Generalized Young-Laplace equation for the bubble pressure resulted in significant differences on the dynamics of bubble dissolution and growth, relative to a simple liquid medium. Depending on whether the salient parameters (solute concentration, initial bubble radius, surface tension, and shear modulus) lead to bubble growth or dissolution, the effect of allowing for a non-zero shear modulus in the Generalized Young-Laplace equation is to speed up the rate of bubble growth, or to reduce the rate of bubble dissolution, respectively. The relation to previous work on visco-elastic materials is discussed, as is the connection of this work to the problem of Decompression Sickness (specifically, "the bends"). Examples of tissues to which our expressions can be applied are provided. Also, a new phenomenon is predicted whereby, for some parameter values, a bubble can be metastable and persist for long times, or it may grow, when embedded in a homogeneous under-saturated soft elastic medium.

J. M. Solano-Altamirano; John D. Malcolm; Saul Goldman

2014-10-14T23:59:59.000Z

76

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

SciTech Connect (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

77

Reactor Physics  

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

Reactor Physics Reactor and nuclear physics is a key area of research at INL. Much of the research done in reactor physics can be separated into one of three categories:...

78

Microfluidics Formation of Bubbles in a Multisection Flow-Focusing  

E-Print Network [OSTI]

Microfluidics Formation of Bubbles in a Multisection Flow-Focusing Junction Michinao Hashimoto the stable formation of trains of mono-, bi-, and tri-disperse bubbles in microfluidic flow- focusing (FF-assembly through the patterns of flow created by the bubbles. 1.1 Bubbles and Droplets in Microfluidics

Prentiss, Mara

79

Neutron field parameter measurements on the JET tokamak by means of super-heated fluid detectors  

SciTech Connect (OSTI)

The neutron field parameters (fluence and energy distribution) at a specific location outside the JET Torus Hall have been measured by means of super-heated fluid detectors (or 'bubble detectors') in combination with an independent, time-of-flight, technique. The bubble detector assemblies were placed at the end of a vertical line of sight at about 16 m from the tokamak mid plane. Spatial distributions of the neutron fluence along the radial and toroidal directions have been obtained using two-dimensional arrays of bubble detectors. Using a set of three bubble detector spectrometers the neutron energy distribution was determined over a broad energy range, from about 10 keV to above 10 MeV, with an energy resolution of about 30% at 2.5 MeV. The very broad energy response allowed for the identification of energy features far from the main fusion component (around 2.45 MeV for deuterium discharges).

Gherendi, M.; Craciunescu, T.; Pantea, A. [Association EURATOM-MEdC, National Institute for Laser, Plasma and Radiation Physics, Magurele (Romania); Zoita, V. L. [Association EURATOM-MEdC, National Institute for Laser, Plasma and Radiation Physics, Magurele (Romania); EFDA-JET CSU Culham, Culham Science Centre, Abingdon (United Kingdom); Johnson, M. Gatu; Hellesen, C.; Conroy, S. [Association EURATOM-VR, Uppsala University, Uppsala (Sweden); Baltog, I. [Association EURATOM-MEdC, National Institute for Material Physics, Magurele (Romania); Edlington, T.; Kiptily, V.; Popovichev, S. [Association EURATOM-CCFE, Culham Science Centre, Abingdon (United Kingdom); Murari, A. [EFDA-JET CSU Culham, Culham Science Centre, Abingdon (United Kingdom); Association EURATOM-ENEA, RFX, Padova (Italy); Collaboration: JET EFDA Contributors

2012-10-15T23:59:59.000Z

80

REVIEW ARTIC LE MICROSCALE THERMAL BUBBLE FORMATION  

E-Print Network [OSTI]

8 C a thermal diffusivity, m r s 8 C 2 F excess heat conduction shape factor e variable in the heat, and this article discusses microscale bubble formation by using polysilicon microheaters. Figure 1a shows

Lin, Liwei

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

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

82

Analytical Modeling of a Bubble Column Dehumidifier  

E-Print Network [OSTI]

Bubble column dehumidifiers are a compact, inexpensive alternative to conventional fin-tube dehumidifiers for humidification-dehumidification (HDH) desalination, a technology that has promising applications in small-scale ...

Tow, Emily W.

83

aBubbleTree? Thomas H. Parker  

E-Print Network [OSTI]

on Rn \\ {0}. That limit loses energy. A bubble tree is a way of recovering the lost energy by keepingaBubbleTree? Thomas H. Parker 666 NOTICES OF THE AMS VOLUME 50, NUMBER 6 Some of the most important for functions u on a domain in R2, which arises as the variational equation of the energy (2) E(u) = |du|2 dvol

Parker, Thomas H.

84

Jets at all scales  

E-Print Network [OSTI]

I discuss recent developments in the field of relativistic jets in AGNs. After a brief review of our current knowledge of emission from Blazars, I discuss some consequences of the recent detection made by {\\it Chandra} of X-ray emission from extended jets. Finally I report some recent results on the problem of the connection between accretion and jets, study that in principle could shed light on the important issue of jet formation.

F. Tavecchio

2002-12-11T23:59:59.000Z

85

DIMUON PRODUCTION BY HIGH ENERGY NEUTRINOS AND ANTINEUTRINOS IN THE FERMILAB FIFTEEN-FOOT BUBBLE CHAMBER  

E-Print Network [OSTI]

ANTINEUTRINOS IN THE FERMILAB FIFTEEN-FOOT BUBBLE CHAMBERANTINEUTRINOS IN THE FERMILAB FIFTEEN-FOOT BUBBLE CHAMBER*ANTINEUTRINOS IN THE FERMILAB FIFTEEN-FOOT BUBBLE CHAMBER

Orthel, John L.

2010-01-01T23:59:59.000Z

86

Microquasars and Jets  

E-Print Network [OSTI]

I present an overview of past, present and future research on microquasars and jets, showing that microquasars, i.e. galactic jet sources, are among the best laboratories for high energy phenomena. After remindind the analogy with quasars, I focus on one of the best microquasar representatives, probably the archetype, namely GRS 1915+105, and present accretion and ejection phenomena, showing that only a multi-wavelength approach allows a better understanding of phenomena occuring in these sources. Thereafter, I review jets at different scales: compact jets, large-scale jets, and the interactions between ejections and the surrounding medium. I finish by speaking about microblazars and ultraluminous X-ray sources.

Sylvain Chaty

2005-06-01T23:59:59.000Z

87

On the (im)possibility of warp bubbles  

E-Print Network [OSTI]

Various objections against Alcubierre's warp drive geometry are reviewed. Superluminal warp bubbles seem an unlikey possibility within the framework of general relativity and quantum field theory, although subluminal bubbles may still be possible.

Chris Van Den Broeck

2000-05-18T23:59:59.000Z

88

On acoustic cavitation of slightly subcritical bubbles Anthony Harkin  

E-Print Network [OSTI]

On acoustic cavitation of slightly subcritical bubbles Anthony Harkin Department of Mathematics, such as submicron air bubbles in water, where the natural oscilla- tion frequencies are high. In contrast, when

Kaper, Tasso J.

89

Bubble Coalescence DOI: 10.1002/anie.201006552  

E-Print Network [OSTI]

by the surface tension of the liquid. They are vital components in foams, microflui- dics,[1] sonochemical cantilever to pick one bubble up in the size range 50­ 200 mm from a glass substrate, and drive this bubble

Chan, Derek Y C

90

Behavior of shale oil jet fuels at variable severities  

SciTech Connect (OSTI)

Catalytic hydroprocessed shale oil jet fuels in the USA were characterized and compared with petroleum jet fuel to demonstrate their possibility as a conventional jet fuel substitute. The shale oils (Geokinetics, Occidental, Paraho and Tosco II) were hydrotreated in a 0.058m ID by 1.52m long reactor containing Ni/MO/Al/sub 2/O/sub 3/ catalyst. The fractionated hydrogenated shale oils at jet fuel ranges (120-300/sup 0/C) were analyzed for composition and physical properties. The increasing hydroprocessing severity proportionally decreased nitrogen, sulfur, olefins, and aromatics, and increased hydrogen content. The nitrogen content even at high severity conditions was considerably higher than that of conventional jet fuel. Sulfur and olefin contents were lower at all severities. The heat of combustion and the physical properties, except the freezing point, were comparable to petroleum jet fuels. The yields of jet fuels increased proportionally to increased severity. The study showed that high severity hydroprocessing gave better performance in processing shale oils to jet fuels.

Mukherjee, N.L.

1988-01-01T23:59:59.000Z

91

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

92

Engineering development of a bubble tray structure  

E-Print Network [OSTI]

~ ~ ~ e r ~ a e e a pl STRUC'FURRS e ~ ~ ~ e e ~ ~ ~ a ~ e ~ ~ * * ~ ~ 9efkoitkoa end Pox'yoee. Ms@@v@nCages 08 Pxevtouely Existing Marble TII'@g 84~55'gt'SSe Reeogniaatlon oZ @he Need toe a New 98@83, 09$fLCa XX. FRELXKX?ARV X~STXGATXOH AH9... ~ Glibsoh Truss-Type Bubble Tray * ~ ?ultiple Gang Punching oi' Tx'ay Parts. . . . . , . . . . . Special Automatic Slotting Yiachine for Bubble Caps. Special Kulti-spindle Tapping I~iachine. . . . . Special Continuous Conveyor Furnace for Heat Tx...

Glitsch, Hans C

1954-01-01T23:59:59.000Z

93

Hotspots, Jets and Environments  

E-Print Network [OSTI]

I discuss the nature of `hotspots' and `jet knots' in the kpc-scale structures of powerful radio galaxies and their relationship to jet-environment interactions. I describe evidence for interaction between the jets of FRI sources and their local environments, and discuss its relationship to particle acceleration, but the main focus of the paper is the hotspots of FRIIs and on new observational evidence on the nature of the particle acceleration associated with them.

M. J. Hardcastle

2007-07-12T23:59:59.000Z

94

Three-dimensional reconstruction of bubble distribution in two-phase bubbly flows with the dynamic programming method  

E-Print Network [OSTI]

A three-dimensional bubble reconstruction method is proposed in this thesis to analyze two-phase bubbly flows. Gas/liquid two-phase flows have important roles in the nuclear and chemical industries and other engineering fields...

Furukawa, Toru

2002-01-01T23:59:59.000Z

95

Heart-shaped bubbles rising in anisotropic liquids Chunfeng Zhou  

E-Print Network [OSTI]

Heart-shaped bubbles rising in anisotropic liquids Chunfeng Zhou Department of Chemical of an unusual inverted-heart shape for bubbles rising in an anisotropic micellar solution. We explain the bubble heart or a spade a . The upper sur- face has sloped shoulders that join in a point. The bottom

Feng, James J.

96

Learning Overcomplete Spatiotemporal Bubbles from Natural Image Sequences  

E-Print Network [OSTI]

of this dot product is given. Simulation results suggest that the overcomplete bubble coding can be achievedLearning Overcomplete Spatiotemporal Bubbles from Natural Image Sequences Libo Ma, and Liqing Zhang, China malibo@sjtu.edu.cn zhang-lq@cs.sjtu.edu.cn Abstract Recently, bubble coding for natural image

Zhang, Liqing

97

A Scalable Turbulent Mixing Aerosol Reactor for Oxide-Coated Silicon Nanoparticles  

E-Print Network [OSTI]

energy supplied to the reactor by high velocity gas jets. The apparatus described here increased the throughput by a factor of 100 above previous laminar flow reactors, and the induced fast mixing enables scaleA Scalable Turbulent Mixing Aerosol Reactor for Oxide-Coated Silicon Nanoparticles Dean M. Holunga

Atwater, Harry

98

Reactor control rod timing system  

SciTech Connect (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, P.T.

1982-02-09T23:59:59.000Z

99

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

100

Do subcritical bubbles hinder first order phase transition?  

E-Print Network [OSTI]

We consider the role played by subcritical bubbles during the electroweak phase transition, estimate their average size, amplitude and formation rate taking into account the crucial role played by thermalization. We also study the influence of subcritical bubbles on the formation of critical bubbles in the thin wall regime and show that, contrary to some recent claims, subcritical bubbles do not affect the nucleation of critical bubbles in an appreciable way. From this fact we conclude that the electroweak baryogenesis scenarios associated with a first order electroweak phase transition still remain an attractive possibility.

K. Enqvist; A. Riotto; I. Vilja

1995-05-19T23:59:59.000Z

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.


101

Maximal air bubble entrainment at liquid drop impact  

E-Print Network [OSTI]

At impact of a liquid drop on a solid surface an air bubble can be entrapped. Here we show that two competing effects minimize the (relative) size of this entrained air bubble: For large drop impact velocity and large droplets the inertia of the liquid flattens the entrained bubble, whereas for small impact velocity and small droplets capillary forces minimize the entrained bubble. However, we demonstrate experimentally, theoretically, and numerically that in between there is an optimum, leading to maximal air bubble entrapment. Our results have a strong bearing on various applications in printing technology, microelectronics, immersion lithography, diagnostics, or agriculture.

Bouwhuis, Wilco; Tran, Tuan; Keij, Diederik L; Winkels, Koen G; Peters, Ivo R; van der Meer, Devaraj; Sun, Chao; Snoeijer, Jacco H; Lohse, Detlef

2012-01-01T23:59:59.000Z

102

J_{E_T}: A Global Jet Finding Algorithm  

E-Print Network [OSTI]

We introduce a new jet-finding algorithm for a hadron collider based on maximizing a J_{E_T} function for all possible combinations of particles in an event. This function prefers a larger value of the jet transverse energy and a smaller value of the jet mass. The jet shape is proved to be a circular cone in Cartesian coordinates with the geometric center shifted from the jet momentum toward the central region. The jet cone size shrinks for a more forward jet. We have implemented our J_{E_T} algorithm with a reasonable running time scaling as N n^3, where "N" is the total number of particles and "n" (much less than N) is the number of particles in a fiducial region. Many features of our J_{E_T} jets are similar to anti-k_t jets, including the reconstructed jet momentum and the "back-reaction" from soft contamination. Nevertheless, when the jet parameters in the two algorithms are matched using QCD jets, we find that the J_{E_T} algorithm has a larger efficiency than anti-k_t for identifying objects with hard splittings such as a W-jet.

Yang Bai; Zhenyu Han; Ran Lu

2014-11-13T23:59:59.000Z

103

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

104

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.

Lau, Louis K. (Monroeville, PA); Alper, Naum I. (Monroeville, PA)

1994-01-01T23:59:59.000Z

105

Effect of severity on catalytic hydroprocessed shale oil jet fuels  

SciTech Connect (OSTI)

Catalytic hydroprocessed shale oil jet fuels in the USA were characterized and compared with petroleum jet fuel to demonstrate their possibility as a conventional jet fuel substitute. The shale oils (Geokinetics, Occidental, Paraho and Tosco II) were hydrotreated in a 0.0508m ID by K1.524m long reactor containing Ni/Mo/Al/sub 2/O/sub 3/ catalyst. The fractionated hydrogenated shale oils at jet fuel ranges (120-300/degree/C) were analyzed for composition and physical properties. The increasing hydroprocessing severity proportionally decreased nitrogen, sulfur, olefins, aromatics and increased hydrogen content. The nitrogen content was considerable higher even at high severity conditions. Sulfur and olefin contents were lower at all severities. The heat of combustion and the physical properties, except the freezing point, were comparable to petroleum jet fuels. The yields of jet fuels increased proportionally to increased severity. The study showed that high severity hydroprocessing gave better performance in processing shale oils to jet fuels.

Mukherjee, N.L.

1987-01-01T23:59:59.000Z

106

Bubbling the Newly Grown Black Ring Hair  

E-Print Network [OSTI]

New families of BPS black ring solutions with four electric and four dipole magnetic charges have recently been explicitly constructed and uplifted to M-theory. These solutions were found to belong to a CFT with central charge different compared to the one of the STU model. Because of their importance to AdS/CFT, here we give the microstate description of these geometries in terms of topological bubbles and supertubes. The fourth charge results in an additional flux through the topological cycles that resolve the brane singularities. The analog of these solutions in the IIB frame yield a generalized regular supertube with three electric charges and one dipole charge. Direct comparison is also made with the previously-known bubbled geometries.

Orestis Vasilakis

2012-02-08T23:59:59.000Z

107

Angular Scaling In Jets  

SciTech Connect (OSTI)

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

ATLAS Jet Energy Scale  

E-Print Network [OSTI]

Jets originating from the fragmentation of quarks and gluons are the most common, and complicated, final state objects produced at hadron colliders. A precise knowledge of their energy calibration is therefore of great importance at experiments at the Large Hadron Collider at CERN, while is very difficult to ascertain. We present in-situ techniques and results for the jet energy scale at ATLAS using recent collision data. ATLAS has demonstrated an understanding of the necessary jet energy corrections to within \\approx 4% in the central region of the calorimeter.

D. Schouten; A. Tanasijczuk; M. Vetterli; for the ATLAS Collaboration

2012-01-11T23:59:59.000Z

109

Bubble Radiation Detection: Current and Future Capability  

SciTech Connect (OSTI)

Despite a number of noteworthy achievements in other fields, superheated droplet detectors (SDDs) and bubble chambers (BCs) have not been used for nuclear nonproliferation and arms control. This report examines these two radiation-detection technologies in detail and answers the question of how they can be or should be ''adapted'' for use in national security applications. These technologies involve closely related approaches to radiation detection in which an energetic charged particle deposits sufficient energy to initiate the process of bubble nucleation in a superheated fluid. These detectors offer complete gamma-ray insensitivity when used to detect neutrons. They also provide controllable neutron-energy thresholds and excellent position resolution. SDDs are extraordinarily simple and inexpensive. BCs offer the promise of very high efficiency ({approximately}75%). A notable drawback for both technologies is temperature sensitivity. As a result of this problem, the temperature must be controlled whenever high accuracy is required, or harsh environmental conditions are encountered. The primary findings of this work are listed and briefly summarized below: (1) SDDs are ready to function as electronics-free neutron detectors on demand for arms-control applications. The elimination of electronics at the weapon's location greatly eases the negotiability of radiation-detection technologies in general. (2) As a result of their high efficiency and sharp energy threshold, current BCs are almost ready for use in the development of a next-generation active assay system. Development of an instrument based on appropriately safe materials is warranted. (3) Both kinds of bubble detectors are ready for use whenever very high gamma-ray fields must be confronted. Spent fuel MPC and A is a good example where this need presents itself. (4) Both kinds of bubble detectors have the potential to function as low-cost replacements for conventional neutron detectors such as {sup 3}He tubes. For SDDs, this requires finding some way to get boron into the detector. For BCs, this requires finding operating conditions permitting a high duty cycle.

AJ Peurrung; RA Craig

1999-11-15T23:59:59.000Z

110

Assessment of RELAP5/MOD3.1 for gravity-driven injection experiment in the core makeup tank of the CARR Passive Reactor (CP-1300)  

SciTech Connect (OSTI)

The objective of the present work is to improve the analysis capability of RELAP5/MOD3.1 on the direct contact condensation in the core makeup tank (CMT) of passive high-pressure injection system (PHPIS) in the CARR Passive Reactor (CP-1300). The gravity-driven injection experiment is conducted by using a small scale test facility to identify the parameters having significant effects on the gravity-driven injection and the major condensation modes. It turns out that the larger the water subcooling is, the more initiation of injection is delayed, and the sparger and the natural circulation of the hot water from the steam generator accelerate the gravity-driven injection. The condensation modes are divided into three modes: sonic jet, subsonic jet, and steam cavity. RELAP5/MOD3.1 is chosen to evaluate the cod predictability on the direct contact condensation in the CMT. It is found that the predictions of MOD3.1 are in better agreement with the experimental data than those of MOD3.0. From the nodalization study of the test section, the 1-node model shows better agreement with the experimental data than the multi-node models. RELAP5/MOD3.1 identifies the flow regime of the test section as vertical stratification. However, the flow regime observed in the experiment is the subsonic jet with the bubble having the vertical cone shape. To accurately predict the direct contact condensation in the CMT with RELAP5/MOD3.1, it is essential that a new set of the interfacial heat transfer coefficients and a new flow regime map for direct contact condensation in the CMT be developed.

Lee, S.I.; No, H.C. [Korea Advanced Inst. of Science and Technology, Yusung, Taejon (Korea, Republic of). Nuclear Engineering Dept.; Bang, Y.S.; Kim, H.J. [Korea Inst. of Nuclear Safety, Yusung Taejon (Korea, Republic of). Advanced Reactor Dept.

1996-10-01T23:59:59.000Z

111

Deformed bubble growth and coalescence in polymer foam processing  

E-Print Network [OSTI]

34 4. 2 4. 3 4. 4 4. 5 4. 6 4. 7 Effect of viscosity on bubble pressure Effect of viscosity on bubble growth . . Effect of viscosity on film thinning Effect of viscosity on film rupture Effect of thc Hamaker number on bubble pressure... studies are markedly different in many aspects: Kramer (1) did not use the lubrication theory approximation; (2) included all of the normal stresses; (3) used convected coordinates which made it easier to use a more complete constitutive description...

Allaboun, Hussein Raji

1996-01-01T23:59:59.000Z

112

Bubble coalescence dynamics and supersaturation in electrolytic gas evolution  

SciTech Connect (OSTI)

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

113

Evaluation of prompt nucleation of bubbles in annular fuel elements during the initial depressurization transient of a DEGB LOCA  

SciTech Connect (OSTI)

In the first moments following the pipe break, of a DEGB LOCA, the depressurization wave is postulated to propagate rapidly through the system, in the manner of an acoustic or water hammer wave. this is immediately followed by a (reflected) repressurization wave, as the flow of coolant through the break is established. The pressure history is then dictated by the flow from the break and the ability of the pressurizer, pumps and accumulators to supply coolant. The initial sudden drop in pressure may result in the system pressure falling below the saturation pressure of the coolant. This could, in turn, result in bubble formation. Such immediate vapor formation (prompt nucleation of bubbles), in the period before the repressurization wave restores the system pressure to a level above the saturation pressure might initiate flow instability. Such an interruption in flow would allow the fuel tube clad temperature to increase rapidly. Depending on the duration of the flow interruption, the reactor might not be able to survive the initial moments of DEGB LOCA. It has generally been that this phenomenon would not actually occur in an operating reactor. The purpose of this investigation is to evaluate the possibility of occurrence of bubble formation as a result of initial depressurization. 7 refs., 6 figs.

Smith, A.C.

1997-06-01T23:59:59.000Z

114

The hydrogen bubble chamber and the strange resonances  

SciTech Connect (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

115

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

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

simulation was conducted using a specialized low Mach number hydrodynamics code for thermonuclear flames. Adaptive mesh refinement was used to focus resolution on the bubble,...

116

Thermonuclear Supernovae: Is Deflagration Triggered by Floating Bubbles?  

E-Print Network [OSTI]

In recent years, it has become clear from multidimensional simulations that the outcome of deflagrations depends strongly on the initial configuration of the flame. We have studied under which conditions this configuration could consist of a number of scattered, isolated, hot bubbles. Afterwards, we have calculated the evolution of deflagrations starting from different numbers of bubbles. We have found that starting from 30 bubbles a mild explosion is produced M(Ni56)=0.56 solar masses, while starting from 10 bubbles the star becomes only marginally unbound (K = 0.05 foes).

Eduardo Bravo; Domingo Garcia-Senz

2002-11-13T23:59:59.000Z

117

Detecting vapour bubbles in simulations of metastable water  

SciTech Connect (OSTI)

The investigation of cavitation in metastable liquids with molecular simulations requires an appropriate definition of the volume of the vapour bubble forming within the metastable liquid phase. Commonly used approaches for bubble detection exhibit two significant flaws: first, when applied to water they often identify the voids within the hydrogen bond network as bubbles thus masking the signature of emerging bubbles and, second, they lack thermodynamic consistency. Here, we present two grid-based methods, the M-method and the V-method, to detect bubbles in metastable water specifically designed to address these shortcomings. The M-method incorporates information about neighbouring grid cells to distinguish between liquid- and vapour-like cells, which allows for a very sensitive detection of small bubbles and high spatial resolution of the detected bubbles. The V-method is calibrated such that its estimates for the bubble volume correspond to the average change in system volume and are thus thermodynamically consistent. Both methods are computationally inexpensive such that they can be used in molecular dynamics and Monte Carlo simulations of cavitation. We illustrate them by computing the free energy barrier and the size of the critical bubble for cavitation in water at negative pressure.

González, Miguel A.; Abascal, Jose L. F.; Valeriani, Chantal, E-mail: christoph.dellago@univie.ac.at, E-mail: cvaleriani@quim.ucm.es [Departamento de Química Fsica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid (Spain); Menzl, Georg; Geiger, Philipp; Dellago, Christoph, E-mail: christoph.dellago@univie.ac.at, E-mail: cvaleriani@quim.ucm.es [Faculty of Physics and Center for Computational Materials Science, University of Vienna, Boltzmanngasse 5, 1090 Vienna (Austria); Aragones, Juan L. [Departamento de Química Fsica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid (Spain); Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Caupin, Frederic [Laboratoire de Physique de la Matiere Condensee et Nanostructures, Universite Claude Bernard, Lyon 1 et CNRS, Institut Universitaire de France, 43 boulevard du 11 novembre 1918, 69100 Villeurbanne (France)

2014-11-14T23:59:59.000Z

118

COLD BUBBLE FORMATION DURING TOKAMAK DENSITY LIMIT DISRUPTIONS  

E-Print Network [OSTI]

COLD BUBBLE FORMATION DURING TOKAMAK DENSITY LIMIT DISRUPTIONS J. HOWARD, M. PERSSON* Plasma Research Laboratory, Research School of Physical Sciences, Australian National University, Canberra

Howard, John

119

Numerical Simulation of Bubble Formation in Co-Flowing Mercury  

SciTech Connect (OSTI)

In this work, we present computational fluid dynamics (CFD) simulations of helium bubble formation and detachment at a submerged needle in stagnant and co-flowing mercury. Since mercury is opaque, visualization of internal gas bubbles was done with proton radiography (pRad) at the Los Alamos Neutron Science Center (LANSCE2). The acoustic waves emitted at the time of detachment and during subsequent oscillations of the bubble were recorded with a microphone. The Volume of Fluid (VOF) model was used to simulate the unsteady two-phase flow of gas injection in mercury. The VOF model is validated by comparing detailed bubble sizes and shapes at various stages of the bubble growth and detachment, with the experimental measurements at different gas flow rates and mercury velocities. The experimental and computational results show a two-stage bubble formation. The first stage involves growing bubble around the needle, and the second follows as the buoyancy overcomes wall adhesion. The comparison of predicted and measured bubble sizes and shapes at various stages of the bubble growth and detachment is in good agreement.

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

2008-01-01T23:59:59.000Z

120

SciTech Connect: ON THE ANALYSIS OF BUBBLE CHAMBER TRACKS  

Office of Scientific and Technical Information (OSTI)

THE ANALYSIS OF BUBBLE CHAMBER TRACKS Citation Details In-Document Search Title: ON THE ANALYSIS OF BUBBLE CHAMBER TRACKS Since its invention by Glaser in 1953, the bubble...

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

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

SciTech Connect (OSTI)

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

122

Nuclear reactor engineering  

SciTech Connect (OSTI)

Chapters are presented concerning energy from nuclear fission; nuclear reactions and radiations; diffusion and slowing-down of neutrons; principles of reactor analysis; nuclear reactor kinetics and control; energy removal; non-fuel reactor materials; the reactor fuel system; radiation protection and environmental effects; nuclear reactor shielding; nuclear reactor safety; and power reactor systems.

Glasstone, S.; Sesonske, A.

1981-01-01T23:59:59.000Z

123

Research reactors - an overview  

SciTech Connect (OSTI)

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

124

Interaction of a Liquid Gallium Jet with ISTTOK Edge Plasmas  

SciTech Connect (OSTI)

The use of liquid metals as plasma facing components in tokamaks has recently experienced a renewed interest stimulated by their advantages in the development of a fusion reactor. Liquid metals have been proposed to solve problems related to the erosion and neutronic activation of solid walls submitted to high power loads allowing an efficient heat exhaust from fusion devices. Presently the most promising candidate materials are lithium and gallium. However, lithium has a short liquid state range when compared, for example, with gallium that has essentially better thermal properties and lower vapor pressure. To explore further these properties, ISTTOK tokamak is being used to test the interaction of a free flying, fully formed liquid gallium jet with the plasma. The interacting, 2.3 mm diameter, jet is generated by hydrostatic pressure and has a 2.5 m/s flow velocity. The liquid metal injector has been build to allow the positioning of the jet inside the tokamak chamber, within a 13 mm range. This paper presents the first obtained experimental results concerning the liquid gallium jet-plasma interaction. A stable jet has been obtained, which was not noticeably affected by the magnetic field transients. ISTTOK has been successfully operated with the gallium jet without degradation of the discharge or a significant plasma contamination by liquid metal. This observation is supported by spectroscopic measurements showing that gallium radiation is limited to the region around the jet. Furthermore, the power deposited on the jet has been evaluated at different radial locations and the surface temperature increase estimated.

Gomes, R. B.; Fernandes, H.; Silva, C.; Pereira, T.; Figueiredo, J.; Carvalho, B.; Soares, A.; Duarte, P.; Varandas, C. [Associacao EURATOM/IST, Centro de Fusao Nuclear, Av. Rovisco Pais, 1049-001 Lisboa, Porugal (Portugal); Sarakovskis, A.; Lielausis, O.; Klyukin, A.; Platacis, E.; Tale, I. [Association EURATOM/University of Latvia, Institute of Solid State Physics, 8 Kengaraga Str., LV-1063 Riga (Latvia)

2008-04-07T23:59:59.000Z

125

Light Water Reactor Sustainability  

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

3 Light Water Reactor Sustainability Program ACCOMPLISHMENTS REPORT 2013 Accomplishments Report | Light Water Reactor Sustainability 2 T he mission of the Light Water Reactor...

126

Light Water Reactor Sustainability  

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

4 Light Water Reactor Sustainability ACCOMPLISHMENTS REPORT 2014 Accomplishments Report | Light Water Reactor Sustainability 2 T he mission of the Light Water Reactor...

127

E-Print Network 3.0 - acoustic cavitation bubble Sample Search...  

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

Collection: Physics 62 Acoustic saturation in bubbly cavitating flow adjacent to an oscillating wall T. Colonius,a) Summary: Acoustic saturation in bubbly cavitating flow...

128

E-Print Network 3.0 - ads vacuum bubbles Sample Search Results  

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

Department of Applied Physics, TU... October 2000 A new type of apparatus for the production of single bubbles of adjustable size is presented... . A single bubble is generated...

129

acoustic cavitation of slightly subcritical bubbles of Mathematics, Boston University, Boston, Massachusetts 02215  

E-Print Network [OSTI]

On acoustic cavitation of slightly subcritical bubbles Anthony ¡ Harkin Department in liquids when surface tension is the dominant effect, such as submicron air bubbles in water, where

Harkin, Anthony

130

Asymmetric bubble disconnection: persistent vibration evolves into smooth contact  

E-Print Network [OSTI]

the amount of water rushing inwards decreases to 0 as the neck radius goes to 0, all the kinetic energy: Bubble disconnection dynamics. (a) Experimental setup: an air bubble (dark area) is submerged under water: February 2, 2009) Focusing a finite amount of energy dynamically into a vanishingly small amount

Zhang, Wendy

131

Experimental setup for the investigation of bubble mediated gas exchange  

E-Print Network [OSTI]

time. For small bubbles, the gas exchange is therefore directly related to the volume fluxExperimental setup for the investigation of bubble mediated gas exchange Wolfgang Mischler1,2 , Roland Rocholz2 and Bernd J¨ahne1,2 1 Heidelberg Collaboratory for Image Processing, University

Jaehne, Bernd

132

Gas Bubble Formation in Stagnant and Flowing Mercury  

SciTech Connect (OSTI)

Investigations in the area of two-phase flow at the Oak Ridge National Laboratory's (ORNL) Spallation Neutron Source (SNS) facility are progressing. It is expected that the target vessel lifetime could be extended by introducing gas into the liquid mercury target. As part of an effort to validate the two-phase computational fluid dynamics (CFD) model, simulations and experiments of gas injection in stagnant and flowing mercury have been completed. The volume of fluid (VOF) method as implemented in ANSYS-CFX, was used to simulate the unsteady two-phase flow of gas injection into stagnant mercury. Bubbles produced at the upwards-oriented vertical gas injector were measured with proton radiography at the Los Alamos Neutron Science Center. The comparison of the CFD results to the radiographic images shows good agreement for bubble sizes and shapes at various stages of the bubble growth, detachment, and gravitational rise. Although several gas flows were measured, this paper focuses on the case with a gas flow rate of 8 cc/min through the 100-micron-diameter injector needle. The acoustic waves emitted due to the detachment of the bubble and during subsequent bubble oscillations were recorded with a microphone, providing a precise measurement of the bubble sizes. As the mercury flow rate increases, the drag force causes earlier bubble detachment and therefore smaller bubbles.

Wendel, Mark W [ORNL] [ORNL; Abdou, Ashraf A [ORNL] [ORNL; Riemer, Bernie [ORNL] [ORNL; Felde, David K [ORNL] [ORNL

2007-01-01T23:59:59.000Z

133

Multiple jet interactions  

E-Print Network [OSTI]

Type Designation Key Direction of Traverse: A - Axial R ? Radial A CON1 N (1) (3) (2) (2) Probe Type: N - Straight, a=O' S - Slant, a=45' (3) Configuration: CON1 CON2 CON3 CON4 CONS CON6 Jets h/D X/h 8 5. 0 16 2. 5 5. 33 7. 5 8 5. 0..., h/D=8. 0 and 2 Jets, h/D=8. 0. 0. 30 SYM INFORMATION: 8 RUN 24 RCON4N X/0 40 0. 25 oo 0. 20 0. 10 0. 05 0. 00 -0 4 -0 3 -0 2 -0. 1 0 0 0. 1 0 2 0 3 0 4 TyX Fig. 24 Distribution of Turbulence Intensity for 2 Jets, b/D=16. 0. 0. 30 BYN...

Hehr, Roger James

2012-06-07T23:59:59.000Z

134

Jet Substructure by Accident  

E-Print Network [OSTI]

We propose a new search strategy for high-multiplicity hadronic final states. When new particles are produced at threshold, the distribution of their decay products is approximately isotropic. If there are many partons in the final state, it is likely that several will be clustered into the same large-radius jet. The resulting jet exhibits substructure, even though the parent states are not boosted. This "accidental" substructure is a powerful discriminant against background because it is more pronounced for high-multiplicity signals than for QCD multijets. We demonstrate how to take advantage of accidental substructure to reduce backgrounds without relying on the presence of missing energy. As an example, we present the expected limits for several R-parity violating gluino decay topologies. This approach allows for the determination of QCD backgrounds using data-driven methods, which is crucial for the feasibility of any search that targets signatures with many jets and suppressed missing energy.

Timothy Cohen; Eder Izaguirre; Mariangela Lisanti; Hou Keong Lou

2013-04-23T23:59:59.000Z

135

Jet Substructure by Accident  

E-Print Network [OSTI]

We propose a new search strategy for high-multiplicity hadronic final states. When new particles are produced at threshold, the distribution of their decay products is approximately isotropic. If there are many partons in the final state, it is likely that several will be clustered into the same large-radius jet. The resulting jet exhibits substructure, even though the parent states are not boosted. This "accidental" substructure is a powerful discriminant against background because it is more pronounced for high-multiplicity signals than for QCD multijets. We demonstrate how to take advantage of accidental substructure to reduce backgrounds without relying on the presence of missing energy. As an example, we present the expected limits for several R-parity violating gluino decay topologies. This approach allows for the determination of QCD backgrounds using data-driven methods, which is crucial for the feasibility of any search that targets signatures with many jets and suppressed missing energy.

Cohen, Timothy; Lisanti, Mariangela; Lou, Hou Keong

2012-01-01T23:59:59.000Z

136

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

137

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

138

Bioconversion reactor  

DOE Patents [OSTI]

A bioconversion reactor for the anaerobic fermentation of organic material. The bioconversion reactor comprises a shell enclosing a predetermined volume, an inlet port through which a liquid stream containing organic materials enters the shell, and an outlet port through which the stream exits the shell. A series of vertical and spaced-apart baffles are positioned within the shell to force the stream to flow under and over them as it passes from the inlet to the outlet port. The baffles present a barrier to the microorganisms within the shell causing them to rise and fall within the reactor but to move horizontally at a very slow rate. Treatment detention times of one day or less are possible.

McCarty, Perry L. (Stanford, CA); Bachmann, Andre (Palo Alto, CA)

1992-01-01T23:59:59.000Z

139

Relativistic Jets and Long-Duration Gamma-ray Bursts from the Birth of Magnetars  

E-Print Network [OSTI]

We present time-dependent axisymmetric magnetohydrodynamic simulations of the interaction of a relativistic magnetized wind produced by a proto-magnetar with a surrounding stellar envelope, in the first $\\sim 10$ seconds after core collapse. We inject a super-magnetosonic wind with $\\dot E = 10^{51}$ ergs s$^{-1}$ into a cavity created by an outgoing supernova shock. A strong toroidal magnetic field builds up in the bubble of plasma and magnetic field that is at first inertially confined by the progenitor star. This drives a jet out along the polar axis of the star, even though the star and the magnetar wind are each spherically symmetric. The jet has the properties needed to produce a long-duration gamma-ray burst (GRB). At $\\sim 5$ s after core bounce, the jet has escaped the host star and the Lorentz factor of the material in the jet at large radii $\\sim 10^{11}$ cm is similar to that in the magnetar wind near the source. Most of the spindown power of the central magnetar escapes via the relativistic jet. There are fluctuations in the Lorentz factor and energy flux in the jet on $\\sim 0.01-0.1$ second timescale. These may contribute to variability in GRB emission (e.g., via internal shocks).

N. Bucciantini; E. Quataert; J. Arons; B. D. Metzger; Todd A. Thompson

2007-09-26T23:59:59.000Z

140

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

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

Gasoline Jet Fuels  

E-Print Network [OSTI]

C4n= Diesel Gasoline Jet Fuels C O C5: Xylose C6 Fermentation of sugars Biofuel "Nanobowls" are inorganic catalysts that could provide the selectivity for converting sugars to fuels IACT Proposes Synthetic, Inorganic Catalysts to Produce Biofuels Current Process

Kemner, Ken

142

Vortex diode jet  

DOE Patents [OSTI]

A fluid transfer system that combines a vortex diode with a jet ejector to transfer liquid from one tank to a second tank by a gas pressurization method having no moving mechanical parts in the fluid system. The vortex diode is a device that has a high resistance to flow in one direction and a low resistance to flow in the other.

Houck, Edward D. (Idaho Falls, ID)

1994-01-01T23:59:59.000Z

143

Neutronic reactor  

DOE Patents [OSTI]

A nuclear reactor includes an active portion with fissionable fuel and neutron moderating material surrounded by neutron reflecting material. A control element in the active portion includes a group of movable rods constructed of neutron-absorbing material. Each rod is movable with respect to the other rods to vary the absorption of neutrons and effect control over neutron flux.

Wende, Charles W. J. (Augusta, GA); Babcock, Dale F. (Wilmington, DE); Menegus, Robert L. (Wilmington, DE)

1983-01-01T23:59:59.000Z

144

Jet quenching and elliptic flow  

E-Print Network [OSTI]

In jet quenching, a hard QCD parton, before fragmenting into a jet of hadrons, deposits a fraction of its energy in the medium, leading to suppressed production of high-$p_T$ hadrons. Assuming that the deposited energy quickly thermalizes, we simulate the subsequent hydrodynamic evolution of the QGP fluid. Explicit simulation of Au+Au collision with and without a quenching jet indicate that elliptic flow is greatly reduced in a jet event. The result can be used to identify the jet events in heavy ion collisions.

A. K. Chaudhuri

2007-08-29T23:59:59.000Z

145

Rapidity-Dependent Jet Vetoes  

E-Print Network [OSTI]

Jet vetoes are a prominent part of the signal selection in various analyses at the LHC. We discuss jet vetoes for which the transverse momentum of a jet is weighted by a smooth function of the jet rapidity. With a suitable choice of the rapidity-weighting function, such jet-veto variables can be factorized and resummed allowing for precise theory predictions. They thus provide a complementary way to divide phase space into exclusive jet bins. In particular, they provide a natural and theoretically clean way to implement a tight veto on central jets with the veto constraint getting looser for jets at increasingly forward rapidities. We mainly focus our discussion on the 0-jet case in color-singlet processes, using Higgs production through gluon fusion as a concrete example. For one of our jet-veto variables we compare the resummed theory prediction at NLL'+NLO with the recent differential cross section measurement by the ATLAS experiment in the $H\\to\\gamma\\gamma$ channel, finding good agreement. We also propose that these jet-veto variables can be measured and tested against theory predictions in other SM processes, such as Drell-Yan, diphoton, and weak diboson production.

Shireen Gangal; Maximilian Stahlhofen; Frank J. Tackmann

2014-12-15T23:59:59.000Z

146

Dispersion and combustion of a bitumen-based emulsion in bubbling fluidized bed  

SciTech Connect (OSTI)

An experimental program was carried out with ORIMULSION{reg{underscore}sign} as a part of an R and D project aimed at demonstrating the feasibility of contemporary combustion and desulfurization in atmospheric bubbling fluidized bed. ORIMULSION is a bitumen-based emulsion that is produced in Venezuela's Orinoco region with 30% w/w water and about 3% w/w sulfur content (on a dry basis). Two atmospheric, pre-pilot, bubbling bed units were used: a 140 mm ID reactor and a 370 mm ID combustor. The first one provides qualitative and quantitative information on dispersion and in-bed retention of ORIMULSION: to this end the bed is operated batchwise in hot tests without combustion and the fuel can be injected into the bed with or without a gaseous atomization stream. With the second one, steady-state combustion tests are carried out under typical conditions of bubbling FBC. The outcome of the experiments and significance of the results are fully discussed in the paper with reference to the ORIMULSION combustion mechanism. Among the other findings, the following ones appear particularly relevant. (1) A carbon condensed phase is actually formed with the structure of tiny carbon deposits on bed particles, but at a very low rate, as a consequence, combustion (and pollutant formation) is dominated by homogeneous mechanisms. (2) Combustion efficiency is always very high, with values approaching 100% in those tests with higher excess air. (3) The in-bed combustion efficiency is enhanced by those fuel injection conditions that lead to dispersion into fine droplets and to effective mixing within the bed; therefore, contrarily to the case of water suspensions of solid fuels, intense atomization of ORIMULSION is recommended.

Miccio, F.; Miccio, M.; Repetto, L.; Gradassi, A.T.

1999-07-01T23:59:59.000Z

147

Inertial confinement fusion based on the ion-bubble trigger  

SciTech Connect (OSTI)

Triggering the ion-bubble in an inertial confinement fusion, we have developed a novel scheme for the fast ignition. This scheme relies on the plasma cavitation by the wake of an intense laser pulse to generate an ion-bubble. The bubble acts both as an intense electron accelerator and as an electron wiggler. Consequently, the accelerated electrons trapped in the bubble can emit an intense tunable laser light. This light can be absorbed by an ablation layer on the outside surface of the ignition capsule, which subsequently drills it and thereby produces a guide channel in the pellet. Finally, the relativistic electron beam created in the bubble is guided through the channel to the high density core igniting the fusion fuel. The normalized beam intensity and beam energy required for triggering the ignition have been calculated when core is heated by the e-beam. In addition, through solving the momentum transfer, continuity and wave equations, a dispersion relation for the electromagnetic and space-charge waves has been analytically derived. The variations of growth rate with the ion-bubble density and electron beam energy have been illustrated. It is found that the growth rates of instability are significantly controlled by the ions concentration and the e-beam energy in the bubble.

Jafari, S., E-mail: SJafari@guilan.ac.ir; Nilkar, M.; Ghasemizad, A. [Department of Physics, University of Guilan, Rasht 41335-1914 (Iran, Islamic Republic of); Mehdian, H. [Department of Physics and Institute for Plasma Research, Tarbiat Moallem University, Tehran 15614 (Iran, Islamic Republic of)

2014-10-15T23:59:59.000Z

148

Bubble Chambers for Experiments in Nuclear Astrophysics  

E-Print Network [OSTI]

A bubble chamber has been developed to be used as an active target system for low energy nuclear astrophysics experiments. Adopting ideas from dark matter detection with superheated liquids, a detector system compatible with gamma-ray beams has been developed. This detector alleviates some of the limitations encountered in standard measurements of the minute cross sections of interest to stellar environments. While the astrophysically relevant nuclear reaction processes at hydrostatic burning temperatures are dominated by radiative captures, in this experimental scheme we measure the time-reversed processes. Such photodisintegrations allow us to compute the radiative capture cross sections when transitions to excited states of the reaction products are negligible. Due to the transformation of phase space, the photodisintegration cross sections are up to two orders of magnitude higher. The main advantage of the new target-detector system is a density several orders of magnitude higher than conventional gas tar...

DiGiovine, B; Holt, R J; Rehm, K E; Raut, R; Robinson, A; Sonnenschein, A; Rusev, G; Tonchev, A P; Ugalde, C

2015-01-01T23:59:59.000Z

149

Measurements of Gas Bubble Size Distributions in Flowing Liquid Mercury  

SciTech Connect (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

150

Interfacial characteristic measurements in horizontal bubbly two- phase flow  

SciTech Connect (OSTI)

Advances in the study of two-phase flow increasingly require detailed internal structure information upon which theoretical models can be formulated. The void fraction and interfacial area are two fundamental parameters characterizing the internal structure of two-phase flow. However, little information is currently available on these parameters, and its mostly limited to vertical flow configurations. Particularly, there is virtually no data base for the local interfacial area concentration in spite of its necessary in multi-dimensional two-fluid model analysis. In view of the above, the internal phase distribution of cocurrent, air-water bubbly flow in a 50.3 mm diameter transparent pipeline has been experimentally investigated by using a double-sensor resistivity probe. Liquid and gas volumetric superficial velocities ranged from 3.74 to 5.60 m/s and 0.25 to 1.59 m/s, respectively, and average void fractions ranged from 2.12 to 22.5%. The local local values of void fractions, interfacial area concentration, mean bubble diameter, bubble interface velocity, bubble chord-length and bubble frequency distributions were measured. The experimental results indicate that the void fraction, interfacial area concentration and bubble frequency have local maxima near the upper pipe well, and the profiles tend to flatten with increasing void fraction. The observed peak void fraction can reach 0.65, the peak interfacial area can to up to 1000 m{sup 2}/m{sup 3}, and the bubble frequency can reach a value of 2200/s. These ranges of values have never been reported for vertical bubbly flow. It is found that either decreasing the liquid flow rate or increasing the gas flow would increase the local void fraction, the interfacial area concentration and the bubble frequency.

Wang, Z.; Kocamustafaogullari, G.

1990-10-01T23:59:59.000Z

151

Interfacial characteristic measurements in horizontal bubbly two-phase flow  

SciTech Connect (OSTI)

Advances in the study of two-phase flow increasingly require detailed internal structure information upon which theoretical models can be formulated. The void fraction and interfacial area are two fundamental parameters characterizing the internal structure of two-phase flow. However, little information is currently available on these parameters, and it is mostly limited to vertical flow configurations. In view of the above, the internal phase distribution of cocurrent, air-water bubbly flow in a 50.3 mm diameter transparent pipeline has been experimentally investigated by using a double-sensor resistivity probe. Liquid and gas volumetric superficial velocities ranged from 3.74 to 5.60 m/s and 0.25 to 1.59 m/s, respectively, and average void fractions ranged from 2.12 to 22.5%. The local values of void fractions, interfacial area concentration, mean bubble diameter, bubble interface velocity, bubble chord-length and bubble frequency distributions were measured. The experimental results indicate that the void faction, interfacial area concentration and bubble frequency have local maxima near the upper pipe wall, and the profiles tend to flatten with increasing void fraction. The observed peak void fraction can reach 0.65, the peak interfacial area can go up to 900 {approx} 1000 m{sup 2}/m{sup 3}, and the bubble frequency can reach a value of 2200/s. These ranges of values have never been reported for vertical bubbly flow. It is found that either decreasing the liquid flow rate or increasing the gas flow would increase the local void fraction, the interfacial area concentration and the bubble frequency. 85 refs., 124 figs., 2 tabs.

Wang, Z.; Huang, W.D.; Srinivasmurthy, S.; Kocamustafaogullari, G.

1990-10-01T23:59:59.000Z

152

The singularity at the tip of the rising plane bubble: The case of nonzero surface tension  

E-Print Network [OSTI]

The singularity at the tip of the rising plane bubble: The case of nonzero surface tension Prabir pointed bubble in the presenceof surface tension. These bubbles have been recently obtained by Vanden to find the apexangle as a function of the speedof the bubbles for a fixed value of surface tension

Daripa, Prabir

153

Dynamics of Subcritical Bubbles in First Order Phase Transition  

E-Print Network [OSTI]

We derivate the Langevin and the Fokker-Planck equations for the radius of $O(3)$-symmetric subcritical bubbles as a phenomenological model to treat thermal fluctuation. The effect of thermal noise on subcritical bubbles is examined. We find that the fluctuation-dissipation relation holds and that in the high temperature phase the system settles down rapidly to the thermal equilibrium state even if it was in a nonequilibrium state initially. We then estimate the typical size of subcritical bubbles as well as the amplitude of fluctuations on that scale. We also discuss their implication to the electroweak phase transition.

Tetsuya Shiromizu; Masahiro Morikawa; Jun'ichi Yokoyama

1995-09-05T23:59:59.000Z

154

SUBCRITICAL BUBBLES NEAR THE PHASE SPACE DOMAIN WALL  

E-Print Network [OSTI]

We study the subcritical bubble formation near the phase space domain wall. We take into account that the phase of the scalar field can vary using complex U(1) symmetric field and a phenomenological potential with cubic term responsible to symmetry breaking. We show that the presence of the domain wall induces subcritical bubbles so that their formation rate near the wall is considerably larger than far of it. The allowed deviations of the phases of new bubbles are so large that they prevent the system from induced nucleation.

J. Sirkka; I. Vilja

1995-03-31T23:59:59.000Z

155

Fuel Performance Experiments and Modeling: Fission Gas Bubble Nucleation and Growth in Alloy Nuclear Fuels  

SciTech Connect (OSTI)

Advanced fast reactor systems being developed under the DOE's Advanced Fuel Cycle Initiative are designed to destroy TRU isotopes generated in existing and future nuclear energy systems. Over the past 40 years, multiple experiments and demonstrations have been completed using U-Zr, U-Pu-Zr, U-Mo and other metal alloys. As a result, multiple empirical and semi-empirical relationships have been established to develop empirical performance modeling codes. many mechamistic questions about fission as mobility, bubble coalescience, and gas release have been answered through industrial experience, reearch, and empirical understanding. The advent of modern computational materials science, however, opens new doors of development such that physics-based multi-scale models may be developed to enable a new generation of predictive fuel performance codes that are not limited by empiricism.

McDeavitt, Sean; Shao, Lin; Tsvetkov, Pavel; Wirth, Brian; Kennedy, Rory

2014-04-07T23:59:59.000Z

156

The Milky Way Project: Leveraging Citizen Science and Machine Learning to Detect Interstellar Bubbles  

E-Print Network [OSTI]

We present Brut, an algorithm to identify bubbles in infrared images of the Galactic midplane. Brut is based on the Random Forest algorithm, and uses bubbles identified by >35,000 citizen scientists from the Milky Way Project to discover the identifying characteristics of bubbles in images from the Spitzer Space Telescope. We demonstrate that Brut's ability to identify bubbles is comparable to expert astronomers. We use Brut to re-assess the bubbles in the Milky Way Project catalog, and find that 10-30% of the objects in this catalog are non-bubble interlopers. Relative to these interlopers, high-reliability bubbles are more confined to the mid plane, and display a stronger excess of Young Stellar Objects along and within bubble rims. Furthermore, Brut is able to discover bubbles missed by previous searches -- particularly bubbles near bright sources which have low contrast relative to their surroundings. Brut demonstrates the synergies that exist between citizen scientists, professional scientists, and machi...

Beaumont, Christopher; Williams, Jonathan; Kendrew, Sarah; Simpson, Robert

2014-01-01T23:59:59.000Z

157

Fission gas bubble nucleated cavitational swelling of the alpha-uranium phase of irradiated U-Pu-Zr fuel  

SciTech Connect (OSTI)

Cavitational swelling has been identified as a potential swelling mechanism for the alpha uranium phase of irradiated U-Pu-Zr metal fuels for the Integral Fast Reactor being developed at Argonne National Laboratory. The trends of U-Pu-Zr swelling data prior to fuel cladding contact can be interpreted in terms of unrestrained cavitational driven swelling. It is theorized that the swelling mechanisms at work in the alpha uranium phase can be modeled by single vacancy and single interstitial kinetics with intergranular gas bubbles providing the void nuclei, avoiding the use of complicated defect interaction terms required for the calculation of void nucleation. The focus of the kinetics of fission gas evolution as it relates to cavitational swelling is prior to the formation of a significant amount of interconnected porosity and is on the development of small intergranular gas bubbles which can act as void nuclei. Calculations for the evolution of intergranular fission gas bubbles show that they provide critical cavity sizes (i.e., the size above which the cavity will grow by bias-driven vacancy flux) consistent with the observed incubation dose for the onset of rapid swelling and gas release.

Rest, J.

1992-04-01T23:59:59.000Z

158

Modified shielding jet model for twin-jet shielding analysis  

E-Print Network [OSTI]

the slowing of the jet flow due to turbulent mixing and entrainment of particles from the surrounding medium. The empirical formulations and velocity profiles derived for the respective regions of the jet consider this increase in entrained fluid... velocity profiles are integrated over their respective cross sections of the shielding jet to determine the total volumetric flowrate at the specified locations. A slug flow velocity approximation is then determined for each of the desired downstream...

Gilbride, Jennifer Frances

2012-06-07T23:59:59.000Z

159

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

160

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

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

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.

162

Quantum Decoherence of Subcritical Bubble in Electroweak Phase Transition  

E-Print Network [OSTI]

In a weakly first order phase transition the typical scale of a subcritical bubble calculated in our previous papers turned out to be too small. At this scale quantum fluctuations may dominate and our previous classical result may be altered. So we examine the critical size of a subcritical bubble where quantum-to-classical transition occurs through quantum decoherence. We show that this critical size is almost equal to the typical scale which we previously obtained.

Tetsuya Shiromizu

1995-12-14T23:59:59.000Z

163

Relativistic Jets and Long-Duration Gamma-ray Bursts from the Birth of Magnetars  

E-Print Network [OSTI]

We present time-dependent axisymmetric magnetohydrodynamic simulations of the interaction of a relativistic magnetized wind produced by a proto-magnetar with a surrounding stellar envelope, in the first ~10 seconds after core collapse. We inject a super-magnetosonic wind with \\dot E = 10^{51} ergs/s into a cavity created by an outgoing supernova shock. A strong toroidal magnetic field builds up in the bubble of plasma and magnetic field that is at first inertially confined by the progenitor star. This drives a jet out along thepolar axis of the star, even though the star and the magnetar wind are each spherically symmetric. The jet has the properties needed to produce a long-duration gamma-ray burst (GRB). At ~5 s after core bounce, the jet has escaped the host star and the Lorentz factor of the material in the jet at large radii ~10^{11} cm is similar to that in the magnetar wind near the source. Most of the spindown power of the central magnetar escapes via the relativistic jet. There are fluctuations in th...

Bucciantini, N; Arons, J; Metzger, B D; Thompson, Todd A

2007-01-01T23:59:59.000Z

164

Jet initiation of PBX 9502  

SciTech Connect (OSTI)

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

165

Vessel thermal map real-time system for the JET tokamak R. Felton,2  

E-Print Network [OSTI]

temperature than the formerly installed carbon fiber composite tiles, imposes strict thermal restrictions of the tritium retention levels when compared with the previous carbon fiber composite (CFC)-based wall [1]. JET of international thermonuclear experimental reactor-relevant materials for the plasma facing components (PFCs

166

Buoyant jet behavior in confined regions  

E-Print Network [OSTI]

Previous confined jet studies have emphasized the behavior of non-buoyant jets inside ducts or near plane boundaries (Coanda effect). Buoyancy, however, is a major factor in the confined jet behavior experienced in many ...

Fry, David J.

1981-01-01T23:59:59.000Z

167

Hybrid adsorptive membrane reactor  

DOE Patents [OSTI]

A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

Tsotsis, Theodore T. (Huntington Beach, CA); Sahimi, Muhammad (Altadena, CA); Fayyaz-Najafi, Babak (Richmond, CA); Harale, Aadesh (Los Angeles, CA); Park, Byoung-Gi (Yeosu, KR); Liu, Paul K. T. (Lafayette Hill, PA)

2011-03-01T23:59:59.000Z

168

Shocks and Wind Bubbles Around Energetic Pulsars  

E-Print Network [OSTI]

The Crab Nebula demonstrates that neutron stars can interact with their environments in spectacular fashion, their relativistic winds generating nebulae observable across the electromagnetic spectrum. At many previous conferences, astronomers have discussed, debated and puzzled over the complicated structures seen in the Crab, but have been limited to treating most other pulsar wind nebulae (PWNe) as simple calorimeters for a pulsar's spin-down energy. However, with the wealth of high-quality data which have now become available, this situation has changed dramatically. I here review some of the main observational themes which have emerged from these new measurements. Highlights include the ubiquity of pulsar termination shocks, the unambiguous presence of relativistic jets in PWNe, complicated time variability seen in PWN structures, and the use of bow shocks to probe the interaction of pulsar winds with the ambient medium.

Bryan M. Gaensler

2004-05-14T23:59:59.000Z

169

Nuclear reactor engineering  

SciTech Connect (OSTI)

A book is reviewed which emphasizes topics directly related to the light water reactor power plant and the fast reactor power system. Current real-world problems are addressed throughout the text, and a chapter on safety includes much of the postThree Mile Island impact on operating systems. Topics covered include Doppler broadening, neutron resonances, multigroup diffusion theory, reactor kinetics, reactor control, energy removal, nonfuel materials, reactor fuel, radiation protection, environmental effects, and reactor safety.

Glasstone, S.; Sesonske, A.

1982-07-01T23:59:59.000Z

170

Bubble masks for time-encoded imaging of fast neutrons.  

SciTech Connect (OSTI)

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

171

Mercury Jet Studies Tristan Davenne  

E-Print Network [OSTI]

Mercury Jet Studies Tristan Davenne Rutherford Appleton Laboratory Joint UKNF, INO, UKIERI meeting mercury target and reported a radial velocity at surface of mercury jet due to proton beam is 36m/s #12;Numerical simulation of Sievers & Pugnat Result Click on image above to watch video of 2cm mercury target

McDonald, Kirk

172

OPENING ANGLES OF COLLAPSAR JETS  

SciTech Connect (OSTI)

We investigate the jet propagation and breakout from the stellar progenitor for gamma-ray burst (GRB) collapsars by performing two-dimensional relativistic hydrodynamic simulations and analytical modeling. We find that the jet opening angle is given by ?{sub j} ? 1/5?{sub 0} and infer the initial Lorentz factor of the jet at the central engine, ?{sub 0}, is a few for existing observations of ?{sub j}. The jet keeps the Lorentz factor low inside the star by converging cylindrically via collimation shocks under the cocoon pressure and accelerates at jet breakout before the free expansion to a hollow-cone structure. In this new picture, the GRB duration is determined by the sound crossing time of the cocoon, after which the opening angle widens, reducing the apparent luminosity. Some bursts violating the maximum opening angle ?{sub j,{sub max}} ? 1/5 ? 12° imply the existence of a baryon-rich sheath or a long-acting jet. We can explain the slopes in both Amati and Yonetoku spectral relations using an off-centered photosphere model, if we make only one assumption that the total jet luminosity is proportional to the initial Lorentz factor of the jet. We also numerically calibrate the pre-breakout model (Bromberg et al.) for later use.

Mizuta, Akira; Ioka, Kunihito [Theory Center, Institute of Particle and Nuclear Studies, KEK, Tsukuba 305-0801 (Japan)

2013-11-10T23:59:59.000Z

173

Electrical breakdown of a bubble in a water-filled capillary  

SciTech Connect (OSTI)

In this Communication, the electrical breakdown of a static bubble in a water-filled capillary generated in a dc electrical field is studied. We present experimental results which indicate that the liquid layer between capillary and bubble wall can have an important influence on the breakdown mechanism of the bubble. The breakdown electrical field (atmospheric pressure) without a liquid layer in a (vapor) bubble is 18 kV/cm. When a liquid layer is present, the electrical breakdown of an air bubble is observed at electrical fields typically two times smaller. Local plasma formation is observed in this case possibly due to bubble deformation.

Bruggeman, P.J.; Leys, C.A.; Vierendeels, J. A. [Department of Applied Physics, Research Unit Plasma Technology (RUPT), Faculty of Engineering, Ghent University, Rozier 44, B-9000 Ghent (Belgium); Department of Flow, Heat and Combustion Mechanics, Faculty of Engineering, Ghent University, Sint-Pietersnieuwstraat 41, B-9000 Ghent (Belgium)

2006-06-01T23:59:59.000Z

174

Computational fluid dynamic modeling of fluidized-bed polymerization reactors  

SciTech Connect (OSTI)

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

175

Plectoneme tip bubbles: Coupled denaturation and writhing in supercoiled DNA  

E-Print Network [OSTI]

Biological information is not only stored in the digital chemical sequence of double helical DNA, but is also encoded in the mechanical properties of the DNA strands, which can influence biochemical processes involving its readout. For example, loop formation in the Lac operon can regulate the expression of key genes, and DNA supercoiling is closely correlated to rhythmic circardian gene expression in cyanobacteria. Supercoiling is also important for large scale organisation of the genome in both eukaryotic and prokaryotic cells. DNA can respond to torsional stress by writhing to form looped structures called plectonemes, thus transferring energy stored as twist into energy stored in bending. Denaturation bubbles can also relax torsional stress, with the enthalpic cost of breaking bonds being compensated by their ability to absorb undertwist. Here we predict a novel regime where bubbles form at the tips of plectonemes, and study its properties using coarse-grained simulations. These tip bubbles can occur for both positive and negative supercoiling and greatly reduce plectoneme diffusion by a pinning mechanism. They can cause plectonemes to preferentially localise to AT rich regions, because bubbles more easily form there. The tip-bubble regime occurs for supercoiling densities and forces that are typically encountered for DNA in vivo, and may be exploited for biological control of genomic processes.

Christian Matek; Thomas E. Ouldridge; Jonathan P. K. Doye; Ard A. Louis

2014-04-10T23:59:59.000Z

176

Oscillating plasma bubbles. III. Internal electron sources and sinks  

SciTech Connect (OSTI)

An internal electron source has been used to neutralize ions injected from an ambient plasma into a spherical grid. The resultant plasma is termed a plasma 'bubble.' When the electron supply from the filament is reduced, the sheath inside the bubble becomes unstable. The plasma potential of the bubble oscillates near but below the ion plasma frequency. Different modes of oscillations have been observed as well as a subharmonic and multiple harmonics. The frequency increases with ion density and decreases with electron density. The peak amplitude occurs for an optimum current and the instability is quenched at large electron densities. The frequency also increases if Langmuir probes inside the bubble draw electrons. Allowing electrons from the ambient plasma to enter, the bubble changes the frequency dependence on grid voltage. It is concluded that the net space charge density in the sheath determines the oscillation frequency. It is suggested that the sheath instability is caused by ion inertia in an oscillating sheath electric field which is created by ion bunching.

Stenzel, R. L.; Urrutia, J. M. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States)

2012-08-15T23:59:59.000Z

177

Exploring GLIMPSE Bubble N107: Multiwavelength Observations and Simulations  

E-Print Network [OSTI]

Context. Bubble N107 was discovered in the infrared emission of dust in the Galactic Plane observed by the Spitzer Space Telescope (GLIMPSE survey: l ~ 51.0 deg, b ~ 0.1 deg). The bubble represents an example of shell-like structures found all over the Milky Way Galaxy. Aims. We aim to analyse the atomic and molecular components of N107, as well as its radio continuum emission. With the help of numerical simulations, we aim to estimate the bubble age and other parameters which cannot be derived directly from observations. Methods. From the observations of the HI (I-GALFA) and 13CO (GRS) lines we derive the bubble's kinematical distance and masses of the atomic and molecular components. With the algorithm DENDROFIND, we decompose molecular material into individual clumps. From the continuum observations at 1420 MHz (VGPS) and 327 MHz (WSRT), we derive the radio flux density and the spectral index. With the numerical code ring, we simulate the evolution of stellar-blown bubbles similar to N107. Results. The tot...

Sidorin, Vojtech; Palous, Jan; Wunsch, Richard; Ehlerova, Sona

2014-01-01T23:59:59.000Z

178

Impact of boundaries on velocity profiles in bubble rafts  

E-Print Network [OSTI]

Under conditions of sufficiently slow flow, foams, colloids, granular matter, and various pastes have been observed to exhibit shear localization, i.e. regions of flow coexisting with regions of solid-like behavior. The details of such shear localization can vary depending on the system being studied. A number of the systems of interest are confined so as to be quasi-two dimensional, and an important issue in these systems is the role of the confining boundaries. For foams, three basic systems have been studied with very different boundary conditions: Hele-Shaw cells (bubbles confined between two solid plates); bubble rafts (a single layer of bubbles freely floating on a surface of water); and confined bubble rafts (bubbles confined between the surface of water below and a glass plate on top). Often, it is assumed that the impact of the boundaries is not significant in the ``quasi-static limit'', i.e. when externally imposed rates of strain are sufficiently smaller than internal kinematic relaxation times. In this paper, we directly test this assumption for rates of strain ranging from $10^{-3}$ to $10^{-2} {\\rm s^{-1}}$. This corresponds to the quoted quasi-static limit in a number of previous experiments. It is found that the top plate dramatically alters both the velocity profile and the distribution of nonlinear rearrangements, even at these slow rates of strain.

Yuhong Wang; Kapilanjan Krishan; Michael Dennin

2006-01-31T23:59:59.000Z

179

The Formation of a Bubble from a Submerged Orifice  

E-Print Network [OSTI]

The formation of a single bubble from an orifice in a solid surface, submerged in an in- compressible, viscous Newtonian liquid, is simulated. The finite element method is used to capture the multiscale physics associated with the problem and to track the evolution of the free surface explicitly. The results are compared to a recent experimental analysis and then used to obtain the global characteristics of the process, the formation time and volume of the bubble, for a range of orifice radii; Ohnesorge numbers, which combine the material parameters of the liquid; and volumetric gas flow rates. These benchmark calculations, for the parameter space of interest, are then utilised to validate a selection of scaling laws found in the literature for two regimes of bubble formation, the regimes of low and high gas flow rates.

Simmons, Jonathan A; Shikhmurzaev, Yulii D

2015-01-01T23:59:59.000Z

180

Electron bubbles in liquid helium: infrared-absorption spectrum  

E-Print Network [OSTI]

Within Density Functional Theory, we have calculated the energy of the transitions from the ground state to the first two excited states in the electron bubbles in liquid helium at pressures from zero to about the solidification pressure. For $^4$He at low temperatures, our results are in very good agreement with infrared absorption experiments. Above a temperature of $\\sim 2$ K, we overestimate the energy of the $1s-1p$ transition. We attribute this to the break down of the Franck-Condon principle due to the presence of helium vapor inside the bubble. Our results indicate that the $1s-2p$ transition energies are sensitive not only to the size of the electron bubble, but also to its surface thickness. We also present results for the infrared transitions in the case of liquid $^3$He, for which we lack of experimental data.

Víctor Grau; Manuel Barranco; Ricardo Mayol; Martí Pi

2006-01-20T23:59:59.000Z

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

Coolant voiding analysis following SGTR for an HLMC reactor  

SciTech Connect (OSTI)

Concepts are under development at Argonne National Laboratory for a small, modular, proliferation-resistant nuclear power steam supply system. Of primary interest here is the simplified system design, featuring steam generators that are directly immersed in the lead-bismuth eutectic (LBE) coolant of the primary system. To support the safety case for this design approach, model development and analysis of transient coolant voiding during a postulated guillotine-type steam generator tube rupture event has been carried out. For the current design, the blowdown will occur from the steam generator shell into the ruptured 12.7-mm-inside-diameter tube through which the LBE coolant passes. The steam will expand biaxially in the tube, with a portion of the flow vented upward to eventually expand into the cover-gas region, while the balance of the flow is vented downward as a jet into the surrounding downward-flowing LBE. Coolant freezing is not an issue in this case because of high feedwater temperature in relation to the freezing point of the LBE. The specific objectives of the current work are to (a) determine the penetration behavior of the steam jet into the lower cold-leg region, (b) characterize the resultant void behavior in terms of coherent bubble versus breakup into a size distribution of small bubbles, and (c) characterize the motion of the bubbles with regard to rise to the cover-gas region (via the liner-to-coolant vessel gap) versus downward transport with the flowing LBE and subsequent upflow through the core to the cover-gas region.

Farmer, M.T.; Spencer, B.W.; Sienicki, J.J.

2000-07-01T23:59:59.000Z

182

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

183

SRS Small Modular Reactors  

SciTech Connect (OSTI)

The small modular reactor program at the Savannah River Site and the Savannah River National Laboratory.

None

2012-04-27T23:59:59.000Z

184

SRS Small Modular Reactors  

ScienceCinema (OSTI)

The small modular reactor program at the Savannah River Site and the Savannah River National Laboratory.

None

2014-05-21T23:59:59.000Z

185

Radiative Decay of Bubble Oscillations in a Compressible Fluid  

E-Print Network [OSTI]

Consider the dynamics of a gas bubble in an inviscid, compressible liquid with surface tension. Kinematic and dynamic boundary conditions couple the bubble surface deformation dynamics with the dynamics of waves in the fluid. This system has a spherical equilibrium state, resulting from the balance of the pressure at infinity and the gas pressure within the bubble. We study the linearized dynamics about this equilibrium state in a center of mass frame: 1) We prove that the velocity potential and bubble surface perturbation satisfy point-wise in space exponential time-decay estimates. 2) The time-decay rate is governed by scattering resonances, eigenvalues of a non-selfadjoint spectral problem. These are pole singularities in the lower half plane of the analytic continuation of a resolvent operator from the upper half plane, across the real axis into the lower half plane. 3) The time-decay estimates are a consequence of resonance mode expansions for the velocity potential and bubble surface perturbations. 4) For small compressibility (Mach number, a ratio of bubble wall velocity to sound speed, \\epsilon), this is a singular perturbation of the incompressible limit. The scattering resonances which govern the anomalously slow time-decay, are {\\it Rayleigh resonances}. Asymptotics, supported by high-precision numerical studies, indicate that the Rayleigh resonances which are closest to the real axis satisfy | \\frac{\\Im \\lambda_\\star(\\epsilon)}{\\Re \\lambda_\\star(\\epsilon)} | = {\\cal O} (\\exp(-\\kappa\\ \\We\\ \\epsilon^{-2})), \\kappa>0. Here, \\We denotes the Weber number, a dimensionless ratio comparing inertia and surface tension. 5) To obtain the above results we prove a general result, of independent interest, estimating the Neumann to Dirichlet map for the wave equation, exterior to a sphere.

A. M. Shapiro; M. I. Weinstein

2011-01-01T23:59:59.000Z

186

Dark matter limits froma 15 kg windowless bubble chamber  

SciTech Connect (OSTI)

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

187

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

188

Liquid uranium alloy-helium fission reactor  

DOE Patents [OSTI]

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

189

E-Print Network 3.0 - automised loop-type bubble Sample Search...  

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

Information Sciences 7 1 Copyright 2004 by ASME SELF-ALIGNED MICRO BUBBLE ARRAYS BY USING SURFACE TENSION Summary: 1 Copyright 2004 by ASME SELF-ALIGNED MICRO BUBBLE ARRAYS BY...

190

Heat and mass transfer in bubble column dehumidifiers for HDH desalination  

E-Print Network [OSTI]

Heat and mass transfer processes governing the performance of bubble dehumidifier trays are studied in order to develop a predictive model and design rules for efficient and economical design of bubble column dehumidifiers ...

Tow, Emily W

2014-01-01T23:59:59.000Z

191

Some hydrodynamic characteristics of bubbly mixtures flowing vertically upward in tubes  

E-Print Network [OSTI]

An investigation of bubbly flow has been conducted in vertical plexiglass tubes using air and water at atmospheric pressure. The bubbly flow pattern is an entrance condition or a non-fully developed flow. A spontaneous ...

Rose, Sewell C.

1964-01-01T23:59:59.000Z

192

Electrochemical investigations of stable cavitation from bubbles generated during reduction of water  

E-Print Network [OSTI]

Electrochemical investigations of stable cavitation from bubbles generated during reduction April 2014 Keywords: Megasonic cleaning Stable cavitation Microstreaming Hydrogen bubbles Water on wafers without affect- ing the transient cavitation responsible for feature damage. Ã? 2014 Elsevier B

Deymier, Pierre

193

Micromachined chemical jet dispenser  

DOE Patents [OSTI]

A dispenser is disclosed for chemical fluid samples that need to be precisely ejected in size, location, and time. The dispenser is a micro-electro-mechanical systems (MEMS) device fabricated in a bonded silicon wafer and a substrate, such as glass or silicon, using integrated circuit-like fabrication technology which is amenable to mass production. The dispensing is actuated by ultrasonic transducers that efficiently produce a pressure wave in capillaries that contain the chemicals. The 10-200 {micro}m diameter capillaries can be arranged to focus in one spot or may be arranged in a larger dense linear array (ca. 200 capillaries). The dispenser is analogous to some ink jet print heads for computer printers but the fluid is not heated, thus not damaging certain samples. Major applications are in biological sample handling and in analytical chemical procedures such as environmental sample analysis, medical lab analysis, or molecular biology chemistry experiments. 4 figs.

Swierkowski, S.P.

1999-03-02T23:59:59.000Z

194

Micromachined chemical jet dispenser  

DOE Patents [OSTI]

A dispenser for chemical fluid samples that need to be precisely ejected in size, location, and time. The dispenser is a micro-electro-mechanical systems (MEMS) device fabricated in a bonded silicon wafer and a substrate, such as glass or silicon, using integrated circuit-like fabrication technology which is amenable to mass production. The dispensing is actuated by ultrasonic transducers that efficiently produce a pressure wave in capillaries that contain the chemicals. The 10-200 .mu.m diameter capillaries can be arranged to focus in one spot or may be arranged in a larger dense linear array (.about.200 capillaries). The dispenser is analogous to some ink jet print heads for computer printers but the fluid is not heated, thus not damaging certain samples. Major applications are in biological sample handling and in analytical chemical procedures such as environmental sample analysis, medical lab analysis, or molecular biology chemistry experiments.

Swierkowski, Steve P. (Livermore, CA)

1999-03-02T23:59:59.000Z

195

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

196

ADVANCED COMPUTATIONAL MODEL FOR THREE-PHASE SLURRY REACTORS  

SciTech Connect (OSTI)

In the second year of the project, the Eulerian-Lagrangian formulation for analyzing three-phase slurry flows in a bubble column is further developed. The approach uses an Eulerian analysis of liquid flows in the bubble column, and makes use of the Lagrangian trajectory analysis for the bubbles and particle motions. An experimental set for studying a two-dimensional bubble column is also developed. The operation of the bubble column is being tested and diagnostic methodology for quantitative measurements is being developed. An Eulerian computational model for the flow condition in the two-dimensional bubble column is also being developed. The liquid and bubble motions are being analyzed and the results are being compared with the experimental setup. Solid-fluid mixture flows in ducts and passages at different angle of orientations were analyzed. The model predictions were compared with the experimental data and good agreement was found. Gravity chute flows of solid-liquid mixtures is also being studied. Further progress was also made in developing a thermodynamically consistent model for multiphase slurry flows with and without chemical reaction in a state of turbulent motion. The balance laws are obtained and the constitutive laws are being developed. Progress was also made in measuring concentration and velocity of particles of different sizes near a wall in a duct flow. The technique of Phase-Doppler anemometry was used in these studies. The general objective of this project is to provide the needed fundamental understanding of three-phase slurry reactors in Fischer-Tropsch (F-T) liquid fuel synthesis. The other main goal is to develop a computational capability for predicting the transport and processing of three-phase coal slurries. The specific objectives are: (1) To develop a thermodynamically consistent rate-dependent anisotropic model for multiphase slurry flows with and without chemical reaction for application to coal liquefaction. Also establish the material parameters of the model. (2) To provide experimental data for phasic fluctuation and mean velocities, as well as the solid volume fraction in the shear flow devices. (3) To develop an accurate computational capability incorporating the new rate-dependent and anisotropic model for analyzing reacting and nonreacting slurry flows, and to solve a number of technologically important problems related to Fischer-Tropsch (F-T) liquid fuel production processes. (4) To verify the validity of the developed model by comparing the predicted results with the performed and the available experimental data under idealized conditions.

Goodarz Ahmadi

2001-10-01T23:59:59.000Z

197

Jets in heavy ion collisions with ATLAS  

E-Print Network [OSTI]

The energy loss of high-p_T partons provides insight into the transport properties of the medium created in relativistic heavy ion collisions. Evidence for this energy loss was first experimentally established through observation of high-p_T hadron suppression at RHIC. More recently, measurements of fully reconstructed jets have been performed at the LHC. In this summary the latest experimental results from the ATLAS collaboration on jet suppression are presented. In particular the jet suppression in inclusive jet yields, path length dependence of the jet suppression, photon-jet and Z^0-jet correlations, heavy flavor suppression, and jet fragmentation are discussed. These results establish qualitative features of the jet quenching mechanism as experimental fact and provide constraints on models of jet energy loss.

Martin Spousta; for the ATLAS Collaboration

2012-11-14T23:59:59.000Z

198

Nuclear reactor  

DOE Patents [OSTI]

A nuclear reactor comprising a cylindrical pressure vessel, an elongated annular core centrally disposed within and spaced from the pressure vessel, and a plurality of ducts disposed longitudinally of the pressure vessel about the periphery thereof, said core comprising an annular active portion, an annular reflector just inside the active portion, and an annular reflector just outside the active a portion, said annular active portion comprising rectangular slab, porous fuel elements radially disposed around the inner reflector and extending the length of the active portion, wedge-shaped, porous moderator elements disposed adjacent one face of each fuel element and extending the length of the fuel element, the fuel and moderator elements being oriented so that the fuel elements face each other and the moderator elements do likewise, adjacent moderator elements being spaced to provide air inlet channels, and adjacent fuel elements being spaced to provide air outlet channels which communicate with the interior of the peripheral ducts, and means for introducing air into the air inlet channels which passes through the porous moderator elements and porous fuel elements to the outlet channel.

Thomson, Wallace B. (Severna Park, MD)

2004-03-16T23:59:59.000Z

199

How important are shock waves to single-bubble sonoluminescence? H. Y. Cheng,1  

E-Print Network [OSTI]

at the center of the bubble could be high enough to ignite thermonuclear fusion 3 . Previous calculations based

Yuan, Li

200

Plasmas in Multiphase Media: Bubble Enhanced Discharges in Liquids and Plasma/Liquid Phase Boundaries  

SciTech Connect (OSTI)

In this research project, the interaction of atmospheric pressure plasmas with multi-phase media was computationally investigated. Multi-phase media includes liquids, particles, complex materials and porous surfaces. Although this investigation addressed fundamental plasma transport and chemical processes, the outcomes directly and beneficially affected applications including biotechnology, medicine and environmental remediation (e.g., water purification). During this project, we made advances in our understanding of the interaction of atmospheric pressure plasmas in the form of dielectric barrier discharges and plasma jets with organic materials and liquids. We also made advances in our ability to use computer modeling to represent these complex processes. We determined the method that atmospheric pressure plasmas flow along solid and liquid surfaces, and through endoscopic like tubes, deliver optical and high energy ion activation energy to organic and liquid surfaces, and produce reactivity in thin liquid layers, as might cover a wound. We determined the mechanisms whereby plasmas can deliver activation energy to the inside of liquids by sustaining plasmas in bubbles. These findings are important to the advancement of new technology areas such as plasma medicine

Kushner, Mark Jay [University of Michigan] [University of Michigan

2014-07-10T23:59:59.000Z

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.


201

How to calibrate the jet energy scale?  

SciTech Connect (OSTI)

Top quarks dominantly decay into b-quark jets and W bosons, and the W bosons often decay into jets, thus the precise determination of the jet energy scale is crucial in measurements of many top quark properties. I present the strategies used by the CDF and D0 collaborations to determine the jet energy scale. The various cross checks performed to verify the determined jet energy scale and evaluate its systematic uncertainty are also discussed.

Hatakeyama, K.; /Rockefeller U.

2006-01-01T23:59:59.000Z

202

A theory for radial jet reattachment flow  

E-Print Network [OSTI]

, the velocity profile and mass entrainment are given accordrng to Goertler's t. wo- dimensional free jet theory. His analysrs of a free jet also assumes that. the turbulent eddy viscosity is constant ar ross the jet. (6) For the case of laminar flow... of total jet momentum. Laminar jet flow is approximated using Schlichting's velocity profile, whereas turbulent flow calculations are made assuming Goertler's velocity profile. Momentum integral principles are applied to the flow at reattachment...

Hadden, Lynne Loise

2012-06-07T23:59:59.000Z

203

Latest jet results from the Tevatron  

SciTech Connect (OSTI)

A brief overview of the latest status of jet physics studies at the Tevatron in proton-antiproton collisions at {radical}s = 1.96 TeV is presented. In particular, measurements of the inclusive jet production cross-section, dijet production and searches for new physics, the ratio of the 3-jet to 2-jet production cross-sections, and the three-jet mass are discussed.

Price, Darren D.

2010-05-01T23:59:59.000Z

204

Long Term Tritium Trapping in TFTR and JET  

SciTech Connect (OSTI)

Tritium retention in TFTR [Tokamak Fusion Test Reactor] and JET [Joint European Torus] shows striking similarities and contrasts. In TFTR, 5 g of tritium were injected into circular plasmas over a 3.5 year period, mostly by neutral-beam injection. In JET, 35 g were injected into divertor plasmas over a 6 month campaign, mostly by gas puffing. In TFTR, the bumper limiter provided a large source of eroded carbon and a major part of tritium was co-deposited on the limiter and vessel wall. Only a small area of the co-deposit flaked off. In JET, the wall is a net erosion area, and co-deposition occurs principally in shadowed parts of the inner divertor, with heavy flaking. In both machines, the initial tritium retention, after a change from deuterium [D] to tritium [T] gas puffing, is high and is due to isotope exchange with deuterium on plasma-facing surfaces (dynamic inventory). The contribution of co-deposition is lower but cumulative, and is revealed by including periods of D fueling that reversed the T/D isotope exchange. Ion beam analysis of flakes from TFTR showed an atomic D/C ratio of 0.13 on the plasma facing surface, 0.25 on the back surface and 0.11 in the bulk. Data from a JET divertor tile showed a larger D/C ratio with 46% C, 30% D, 20% H and 4% O. Deuterium, tritium, and beryllium profiles have been measured and show a thin less than 50 micron co-deposited layer. Flakes retrieved from the JET vacuum vessel exhibited a high tritium release rate of 2e10 Bq/month/g. BBQ modeling of the effect of lithium on retention in TFTR showed overlapping lithium and tritium implantation and a 1.3x increase in local T retention.

C.H. Skinner; C.A. Gentile; K.M. Young; J.P. Coad; J.T. Hogan; R.-D. Penzhorn; and N. Bekris

2001-07-24T23:59:59.000Z

205

HYLIFE-2 inertial confinement fusion reactor design  

SciTech Connect (OSTI)

The HYLIFE-II inertial fusion power plant design study uses a liquid fall, in the form of jets to protect the first structural wall from neutron damage, x-rays, and blast to provide a 30-y lifetime. HYLIFE-I used liquid lithium. HYLIFE-II avoids the fire hazard of lithium by using a molten salt composed of fluorine, lithium, and beryllium (Li{sub 2}BeF{sub 4}) called Flibe. Access for heavy-ion beams is provided. Calculations for assumed heavy-ion beam performance show a nominal gain of 70 at 5 MJ producing 350 MJ, about 5.2 times less yield than the 1.8 GJ from a driver energy of 4.5 MJ with gain of 400 for HYLIFE-I. The nominal 1 GWe of power can be maintained by increasing the repetition rate by a factor of about 5.2, from 1.5 to 8 Hz. A higher repetition rate requires faster re-establishment of the jets after a shot, which can be accomplished in part by decreasing the jet fall height and increasing the jet flow velocity. Multiple chambers may be required. In addition, although not considered for HYLIFE-I, there is undoubtedly liquid splash that must be forcibly cleared because gravity is too slow, especially at high repetition rates. Splash removal can be accomplished by either pulsed or oscillating jet flows. The cost of electricity is estimated to be 0.09$/kW{center dot}h in constant 1988 dollars, about twice that of future coal and light water reactor nuclear power. The driver beam cost is about one-half the total cost. 12 refs., 9 figs., 5 tabs.

Moir, R.W.

1990-10-04T23:59:59.000Z

206

Bubble tree convergence for the harmonic sequence of harmonic surfaces in CPn  

E-Print Network [OSTI]

] and there are no necks [15], i.e. the energy of the bubble tree map is the limit of the energies of the sequenceBubble tree convergence for the harmonic sequence of harmonic surfaces in CPn Mo Xiaohuan and Sun holomorphic (or anti- holomorphic) map from M to CPn , or a "bubble tree limit" consisting of a har- monic map

Lu, Tiao

207

An Experimental Study of Bubble Formation in Asset Markets Using the Ttonnement Trading Institution  

E-Print Network [OSTI]

. Introduction Price bubbles are not a rare phenomenon. Indeed, there are many historical examples of commodity historical and contemporary relevance. The results show that bubbles are significantly reduced, suggesting Markets, Price Bubbles, Trading Institutions, Tâtonnement * Corresponding author. Address: Department

208

Birth and Growth of Cavitation Bubbles within Water under Tension Confined in a Simple Synthetic Tree  

E-Print Network [OSTI]

Birth and Growth of Cavitation Bubbles within Water under Tension Confined in a Simple Synthetic. Cavitation can spontaneously occur, nucleating a bubble. We investigate the dynamics of spontaneous or triggered cavitation inside water filled microcavities of a hydrogel. Results show that a stable bubble

Ohl, Claus-Dieter

209

Molecular and atomic emission during single-bubble cavitation in concentrated sulfuric acid  

E-Print Network [OSTI]

Molecular and atomic emission during single- bubble cavitation in concentrated sulfuric acid David during cavitation. Single-bubble sonoluminescence (SBSL) from sulfuric acid (H2SO4) is much brighter than occurring during single- bubble cavitation. In fact, SBSL spectra from organic liquids8,9 have been

Suslick, Kenneth S.

210

MODELING SPACE-TIME DEPENDENT HELIUM BUBBLE EVOLUTION IN TUNGSTEN ARMOR UNDER IFE CONDITIONS  

E-Print Network [OSTI]

MODELING SPACE-TIME DEPENDENT HELIUM BUBBLE EVOLUTION IN TUNGSTEN ARMOR UNDER IFE CONDITIONS Qiyang dependent Helium transport in finite geometries, including the simultaneous transient production of defects of Helium bubbles. I. INTRODUCTION Helium production and helium bubble evolution in neutron

Ghoniem, Nasr M.

211

Radial flow pulse jet mixer  

DOE Patents [OSTI]

The disclosure provides a pulse jet mixing vessel for mixing a plurality of solid particles. The pulse jet mixing vessel is comprised of a sludge basin, a flow surface surrounding the sludge basin, and a downcoming flow annulus between the flow surface and an inner shroud. The pulse jet mixing vessel is additionally comprised of an upper vessel pressurization volume in fluid communication with the downcoming flow annulus, and an inner shroud surge volume separated from the downcoming flow annulus by the inner shroud. When the solid particles are resting on the sludge basin and a fluid such as water is atop the particles and extending into the downcoming flow annulus and the inner shroud surge volume, mixing occurs by pressurization of the upper vessel pressurization volume, generating an inward radial flow over the flow surface and an upwash jet at the center of the sludge basin.

VanOsdol, John G.

2013-06-25T23:59:59.000Z

212

Strategic Technology JET PROPULSION LABORATORY  

E-Print Network [OSTI]

Strategic Technology Directions JET PROPULSION LABORATORY National Aeronautics and Space Administration 2 0 0 9 #12;© 2009 California Institute of Technology. Government sponsorship acknowledged. #12;Strategic Technology Directions 2009 offers a distillation of technologies, their links to space missions

Waliser, Duane E.

213

Development of a countercurrent multistage fluidized-bed reactor and mathematical modeling for prediction of removal efficiency of sulfur dioxide from flue gases  

SciTech Connect (OSTI)

A bubbling countercurrent multistage fluidized-bed reactor for the sorption of sulfur dioxide by hydrated lime particles was simulated employing a two-phase model, with the bubble phase assumed to be in plug flow and with the emulsion phase either in plug flow (EGPF model) or in perfectly mixed flow (EGPM model). The model calculations were compared with experimental data in term of percentage removal efficiency of sulfur dioxide. Both models were applied to understand the influence of operating parameters on the reactor performance. The comparison showed that the EGPF model agreed well with the experimental data. From the perspective of use of a multistage fluidized-bed reactor as air pollution control equipment in industry, the model could be considered general enough for predicting the performance of reactors for gas-solid treatment.

Mohanty, C.R.; Malavia, G.; Meikap, B.C. [Indian Institute of Technology, Kharagpur (India). Dept. of Chemical Engineering

2009-02-15T23:59:59.000Z

214

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

SciTech Connect (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

215

Numerical Simulations of Bouncing Jets  

E-Print Network [OSTI]

Bouncing jets are fascinating phenomenons occurring under certain conditions when a jet impinges on a free surface. This effect is observed when the fluid is Newtonian and the jet falls in a bath undergoing a solid motion. It occurs also for non-Newtonian fluids when the jets falls in a vessel at rest containing the same fluid. We investigate numerically the impact of the experimental setting and the rheological properties of the fluid on the onset of the bouncing phenomenon. Our investigations show that the occurrence of a thin lubricating layer of air separating the jet and the rest of the liquid is a key factor for the bouncing of the jet to happen. The numerical technique that is used consists of a projection method for the Navier-Stokes system coupled with a level set formulation for the representation of the interface. The space approximation is done with adaptive finite elements. Adaptive refinement is shown to be very important to capture the thin layer of air that is responsible for the bouncing.

Bonito, Andrea; Lee, Sanghyun

2015-01-01T23:59:59.000Z

216

Bubbling Reactor Technology for Rapid Synthesis of Uniform, Small MFI-Type  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAboutScienceCareersEnergy, science,SciencesEnergy,Energy,--Bruce

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

Geometrical Arrangements of a Collection of Bubbles Roman urikovic  

E-Print Network [OSTI]

. ____________________________________________________________________________________________________________________________________ G ­ slovenský casopis pre geometriu a grafiku, rocník 2 (2005), císlo 1, s. 7 - 16 7 #12;RomanGeometrical Arrangements of a Collection of Bubbles Roman urikovic Faculty of Mathematics, Physics and Informatics Comenius University, Slovakia email: roman.durikovic@fmph.uniba.sk Abstrakt V tomto clánku

Durikovic, Roman

219

Mobius Transformations, Power Diagrams, Lombardi Drawings, and Soap Bubbles  

E-Print Network [OSTI]

M¨obius Transformations, Power Diagrams, Lombardi Drawings, and Soap Bubbles David Eppstein Euro a novel type of power diagram for disks in the plane that is invariant under M¨obius transformations Using For points outside circle, power = (positive) length of tangent segment For points inside circle, power = -1

Eppstein, David

220

Acceleration of Preconditioned Krylov Solvers for Bubbly Flow Problems  

E-Print Network [OSTI]

eigen- values in the spectrum of M-1 A, see also [13]. This phenomenon also holds if we use other, preconditioning, sym- metric positive semi-definite matrices, bubbly flow problems. 1 Introduction Recently of this method is solving the symmetric and positive semi-definite (SPSD) linear system on each time step, which

Vuik, Kees

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

Oscillating plasma bubbles. IV. Grids, geometry, and gradients  

SciTech Connect (OSTI)

Plasma bubbles are created in an ambient plasma. The bubble is formed inside a cavity bounded by a negatively biased grid. Ions are injected through the grid and neutralized by electrons from either the background plasma or an internal electron emitter. The external electron supply is controlled by the grid bias relative to the external plasma potential. When the electron flux is restricted to the ion flux, the sheath of the bubble becomes unstable and causes the plasma potential to oscillate near the ion plasma frequency. The exact frequency depends on the net space charge density in the bubble sheath. The frequency increases with density and grid voltage, provided the grid forms a parallel equipotential surface. The present investigation shows that when the Debye length becomes smaller than the grid openings the electron flux cannot be controlled by the grid voltage. The frequency dependence on grid voltage and density is modified creating frequency and amplitude jumps. Low frequency sheath oscillations modulate the high frequency normal oscillations. Harmonics and subharmonics are excited by electrons in an ion-rich sheath. When the plasma parameters vary over the bubble surface, the sheath may oscillate at different frequencies. A cavity with two isolated grids has been used to investigate anisotropies of the energetic electron flux in a discharge plasma. The frequency dependence on grid voltage is entirely different when the grid controls the energetic electrons or the bulk electrons. These observations are important to several fields of basic plasma physics, such as sheaths, sheath instabilities, diagnostic probes, current, and space charge neutralization of ion beams.

Stenzel, R. L. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States); Urrutia, J. M. [Urrutia Scientific, Van Nuys, California 91406 (United States)

2012-08-15T23:59:59.000Z

222

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

223

Study of electron trapping by a transversely ellipsoidal bubble in the laser wake-field acceleration  

SciTech Connect (OSTI)

We present electron trapping in an ellipsoidal bubble which is not well explained by the spherical bubble model by [Kostyukov et al., Phys. Rev. Lett. 103, 175003 (2009)]. The formation of an ellipsoidal bubble, which is elongated transversely, frequently occurs when the spot size of the laser pulse is large compared to the plasma wavelength. First, we introduce the relation between the bubble size and the field slope inside the bubble in longitudinal and transverse directions. Then, we provide an ellipsoidal model of the bubble potential and investigate the electron trapping condition by numerical integration of the equations of motion. We found that the ellipsoidal model gives a significantly less restrictive trapping condition than that of the spherical bubble model. The trapping condition is compared with three-dimensional particle-in-cell simulations and the electron trajectory in test potential simulations.

Cho, Myung-Hoon [School of Natural Science, UNIST, BanYeon-Ri 100, Ulju-gun, Ulsan 689-798 (Korea, Republic of)] [School of Natural Science, UNIST, BanYeon-Ri 100, Ulju-gun, Ulsan 689-798 (Korea, Republic of); Kim, Young-Kuk; Hur, Min Sup [School of Electrical and Computer Engineering, UNIST, BanYeon-Ri 100, Ulju-gun, Ulsan 689-798 (Korea, Republic of)] [School of Electrical and Computer Engineering, UNIST, BanYeon-Ri 100, Ulju-gun, Ulsan 689-798 (Korea, Republic of)

2013-09-15T23:59:59.000Z

224

Undergraduate reactor control experiment  

SciTech Connect (OSTI)

A sequence of reactor and related experiments has been a central element of a senior-level laboratory course at Pennsylvania State University (Penn State) for more than 20 yr. A new experiment has been developed where the students program and operate a computer controller that manipulates the speed of a secondary control rod to regulate TRIGA reactor power. Elementary feedback control theory is introduced to explain the experiment, which emphasizes the nonlinear aspect of reactor control where power level changes are equivalent to a change in control loop gain. Digital control of nuclear reactors has become more visible at Penn State with the replacement of the original analog-based TRIGA reactor control console with a modern computer-based digital control console. Several TRIGA reactor dynamics experiments, which comprise half of the three-credit laboratory course, lead to the control experiment finale: (a) digital simulation, (b) control rod calibration, (c) reactor pulsing, (d) reactivity oscillator, and (e) reactor noise.

Edwards, R.M.; Power, M.A.; Bryan, M. (Pennsylvania State Univ., University Park (United States))

1992-01-01T23:59:59.000Z

225

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

226

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

227

Reactor Sharing Program  

SciTech Connect (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

228

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.; Grohmann, Karel; Himmel, Michael E.; Richard, Christopher J.

1993-03-02T23:59:59.000Z

229

Advanced Test Reactor Tour  

SciTech Connect (OSTI)

The Advanced Test Reactor at Idaho National Laboratory is the foremost nuclear materials test reactor in the world. This virtual tour describes the reactor, how experiments are conducted, and how spent nuclear fuel is handled and stored. For more information about INL research, visit http://www.facebook.com/idahonationallaboratory.

Miley, Don

2011-01-01T23:59:59.000Z

230

Advanced Test Reactor Tour  

ScienceCinema (OSTI)

The Advanced Test Reactor at Idaho National Laboratory is the foremost nuclear materials test reactor in the world. This virtual tour describes the reactor, how experiments are conducted, and how spent nuclear fuel is handled and stored. For more information about INL research, visit http://www.facebook.com/idahonationallaboratory.

Miley, Don

2013-05-28T23:59:59.000Z

231

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

232

Hypothetical Reactor Accident Study  

E-Print Network [OSTI]

- W 4 DfcSkoollo Rise-R-427 CARNSORE: Hypothetical Reactor Accident Study O. Walmod-Larsen, N. O: HYPOTHETICAL REACTOR ACCIDENT STUDY O. Walmod-Larsen, N.O. Jensen, L. Kristensen, A. Heide, K.L. Nedergård, P-basis accident and a series of hypothetical core-melt accidents to a 600 MWe reactor are de- scribed

233

Sensitivity and uncertainty analyses for thermo-hydraulic calculation of research reactor  

SciTech Connect (OSTI)

The sensitivity and uncertainty analysis of input parameters on thermohydraulic calculations for a research reactor has successfully done in this research. The uncertainty analysis was carried out on input parameters for thermohydraulic calculation of sub-channel analysis using Code COOLOD-N. The input parameters include radial peaking factor, the increase bulk coolant temperature, heat flux factor and the increase temperature cladding and fuel meat at research reactor utilizing plate fuel element. The input uncertainty of 1% - 4% were used in nominal power calculation. The bubble detachment parameters were computed for S ratio (the safety margin against the onset of flow instability ratio) which were used to determine safety level in line with the design of 'Reactor Serba Guna-G. A. Siwabessy' (RSG-GA Siwabessy). It was concluded from the calculation results that using the uncertainty input more than 3% was beyond the safety margin of reactor operation.

Hartini, Entin; Andiwijayakusuma, Dinan [Center for Development of Nuclear Informatics - National Nuclear Energy Agency PUSPIPTEK, Serpong, Tangerang, Banten (Indonesia)] [Center for Development of Nuclear Informatics - National Nuclear Energy Agency PUSPIPTEK, Serpong, Tangerang, Banten (Indonesia); Isnaeni, Muh Darwis [Center for Reactor Technology and Nuclear Safety- National Nuclear Energy Agency PUSPIPTEK, Serpong, Tangerang, Banten (Indonesia)] [Center for Reactor Technology and Nuclear Safety- National Nuclear Energy Agency PUSPIPTEK, Serpong, Tangerang, Banten (Indonesia)

2013-09-09T23:59:59.000Z

234

Cooling molten salt reactors using “gas-lift”  

SciTech Connect (OSTI)

This study briefly describes the selection of a type of two-phase flow, suitable for intensifying the natural flow of nuclear reactors with liquid fuel - cooling mixture molten salts and the description of a “Two-phase flow demonstrator” (TFD) used for experimental study of the “gas-lift” system and its influence on the support of natural convection. The measuring device and the application of the TDF device is described. The work serves as a model system for “gas-lift” (replacing the classic pump in the primary circuit) for high temperature MSR planned for hydrogen production. An experimental facility was proposed on the basis of which is currently being built an experimental loop containing the generator, separator bubbles and necessary accessories. This loop will model the removal of gaseous fission products and tritium. The cleaning of the fuel mixture of fluoride salts eliminates problems from Xenon poisoning in classical reactors.

Zitek, Pavel, E-mail: zitek@kke.zcu.cz, E-mail: klimko@kke.zcu.cz; Valenta, Vaclav, E-mail: zitek@kke.zcu.cz, E-mail: klimko@kke.zcu.cz; Klimko, Marek, E-mail: zitek@kke.zcu.cz, E-mail: klimko@kke.zcu.cz [University of West Bohemia in Pilsen, Univerzitní 8, 306 14 Pilsen (Czech Republic)

2014-08-06T23:59:59.000Z

235

Coupling of twin rectangular supersonic jets  

E-Print Network [OSTI]

Twin jet plumes on aircraft can couple, producing dynamic pressures significant enough to cause structural fatigue. For closely spaced jets with a moderate aspect ratio (e.g. 5), previous work has established that two ...

Raman, G.; Taghavi, Ray

1998-01-01T23:59:59.000Z

236

The Georgi Algorithms of Jet Clustering  

E-Print Network [OSTI]

We reveal the direct link between the jet clustering algorithms recently proposed by Howard Georgi and parton shower kinematics, providing sound support from the theoretical side. The kinematics of this class of elegant algorithms is explored systematically and the jet function is generalized to $J^{(n)}_\\beta$ with a jet function index $n$. Based on three basic requirements that the result of jet clustering is process-independent, for softer subjets the inclusion cone is larger, and that the cone size cannot be too large in order to avoid mixing different jets, we derive constraints on the jet function index $n$ and the jet function parameter $\\beta$ which are closely related to phase space boundaries. Finally, we demonstrate that the jet algorithm is boost invariant.

Shao-Feng Ge

2014-08-30T23:59:59.000Z

237

Neutron behavior, reactor control, and reactor heat transfer. Volume four  

SciTech Connect (OSTI)

Volume four covers neutron behavior (neutron absorption, how big are nuclei, neutron slowing down, neutron losses, the self-sustaining reactor), reactor control (what is controlled in a reactor, controlling neutron population, is it easy to control a reactor, range of reactor control, what happens when the fuel burns up, controlling a PWR, controlling a BWR, inherent safety of reactors), and reactor heat transfer (heat generation in a nuclear reactor, how is heat removed from a reactor core, heat transfer rate, heat transfer properties of the reactor coolant).

Not Available

1986-01-01T23:59:59.000Z

238

Theoretical and Experimental Simulation of Accident Scenarios of the JET Cryogenic Components Part I: The JET In-vessel Cryopump  

E-Print Network [OSTI]

Theoretical and Experimental Simulation of Accident Scenarios of the JET Cryogenic Components Part I: The JET In-vessel Cryopump

239

Theoretical and Experimental Simulation of Accident Scenarios of the JET Cryogenic Components Part II: The JET LHCD Cryopump  

E-Print Network [OSTI]

Theoretical and Experimental Simulation of Accident Scenarios of the JET Cryogenic Components Part II: The JET LHCD Cryopump

240

Advanced thermally stable jet fuels  

SciTech Connect (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

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

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

242

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

243

Inclusive jet production at the Tevatron  

SciTech Connect (OSTI)

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

244

Compression-induced stacking fault tetrahedra around He bubbles in Al  

SciTech Connect (OSTI)

Classic molecular dynamics methods are used to simulate the uniform compression process of the fcc Al containing He bubbles. The formation of stacking fault tetrahedra (SFTs) during the collapse of He bubbles is found, and their dependence on the initial He bubble size (0.6–6?nm in diameter) is presented. Our simulations indicate only elastic deformation in the samples for the He bubble size not more than 2?nm. Instead, increasing the He bubble size, we detect several small SFTs forming on the surface of the He bubble (3?nm), as well as the two intercrossed SFTs around the He bubbles (4–6?nm). All these SFTs are observed to be stable under further compression, though there may appear some SF networks outside the SFTs (5–6?nm). Furthermore, the dynamic analysis on the SFTs shows that the yield pressure keeps a near-linear increase with the initial He bubble pressure, and the potential energy of Al atoms inside the SFTs is lower than outside because of their gliding inwards. In addition, the pressure increments of 2–6?nm He bubbles with strain are less than that of Al, which just provides the opportunity for the He bubble collapse and the SFTs formation. Note that the current work only focuses on the case that the number ratio between He atoms and Al vacancies is 1:1.

Shao, Jian-Li, E-mail: shao-jianli@iapcm.ac.cn; Wang, Pei; He, An-Min [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China)

2014-10-28T23:59:59.000Z

245

Spinning fluids reactor  

DOE Patents [OSTI]

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

246

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

2012-03-08T23:59:59.000Z

247

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. 1 figure.

Gluntz, D.M.; Taft, W.E.

1994-12-20T23:59:59.000Z

248

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

249

Monte Carlo Tools for Jet Quenching  

E-Print Network [OSTI]

A thorough understanding of jet quenching on the basis of multi-particle final states and jet observables requires new theoretical tools. This talk summarises the status and propects of the theoretical description of jet quenching in terms of Monte Carlo generators.

Korinna Zapp

2011-09-07T23:59:59.000Z

250

Micro Bubble Technologies Inc MBT | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy Resources Jump to:46 -Energieprojekte GmbH Jump to:Michigan: Energy Resources Jump to: navigation,Bubble

251

Light water reactor safety research program. Volume 12: quarterly report, Apr-Jun 79  

SciTech Connect (OSTI)

This report summarizes the progress of the Light Water Reactor Safety Research Program during the 2nd quarter of 1979. Specifically, the report summarizes progress in five major areas of research. They are: (1) the molten core/concrete interactions study; (2) steam explosion research phenomena; (3) statistical LOCA analysis; (4) UHI model development; (5) two-phase jet loads.

Berman, M.

1980-05-01T23:59:59.000Z

252

Scaling of bubble growth in a porous medium. Topical report  

SciTech Connect (OSTI)

Processes involving liquid-to-gas phase change in porous media are routinely encountered, for example in the recovery of oil, geothermal processes, nuclear waste disposal or enhanced heat transfer. They involve diffusion (and convection) in the pore space, driven by an imposed supersaturation in pressure or temperature. Phase change proceeds by nucleation and phase growth. Depending on pore surface roughness, a number of nucleation centers exist, thus phase growth occurs from a multitude of clusters. Contrary to growth in the bulk or in a Hele-Shaw cell, however, growth patterns in porous media are disordered and not compact. As in immiscible displacements, they reflect the underlying pore microstructure. The competition between multiple clusters is also different from the bulk. For example, cluster growth may be controlled by a combination of diffusion (e.g. Laplace equation in the quasi-static case) with percolation. Novel growth patterns axe expected from this competition. While multiple cluster growth is important, the simpler problem of single-bubble growth is still not well understood. In this section, we focus on the growth of a single bubble, subject to a fixed far-field supersaturation (e.g. by lowering the pressure in a supersaturated solution or by raising the temperature in a. superheated liquid). Our emphasis is on deriving a scaling theory for growth at conditions of quasi-static diffusion, guided by recent experimental observations. Visualization of bubble growth in model porous media was recently conducted using 2-D etched-glass micromodels.

Satik, C.; Yortsos, Y.; Li, X. [Univ. of Southern California, Los Angeles, CA (United States). Dept. of Chemical Engineering

1995-07-01T23:59:59.000Z

253

Photoproduction of jets at NLO  

E-Print Network [OSTI]

A new next-to-leading order Monte Carlo program for the calculation of fully differential jet cross sections in photoproduction is described. The contributions from both resolved and direct components are included. A comparison between the theoretical predictions and ZEUS data is presented.

B. W. Harris; J. F. Owens

1996-08-20T23:59:59.000Z

254

The Disc-Jet Connection  

E-Print Network [OSTI]

A large body of theoretical and computational work shows that jets - modelled as magnetized disk winds - exert an external torque on their underlying disks that can efficiently remove angular momentum and act as major drivers of disk accretion. These predictions have recently been confirmed in direct HST measurements of the jet rotation and angular momentum transport in low mass protostellar systems. We review the theory of disc winds and show that their physics is universal and scales to jets from both low and high mass star forming regions. This explains the observed properties of outflows in massive star forming regions, before the central massive star generates an ultracompact HII region. We also discuss the recent numerical studies on the formation of massive accretion disks and outflows through gravitational collapse, including our own work on 3D Adaptive Mesh simulations (using the FLASH code) of the hydromagnetic collapse of an initial rotating, and cooling Bonner-Ebert sphere. Magnetized collapse gives rise to outflows. Our own simulations show that both a jet-like disk wind on sub AU scales, and a larger scale molecular outflow occur (Banerjee and Pudritz 2005).

Ralph E. Pudritz; Robi Banerjee

2005-07-11T23:59:59.000Z

255

Laser Created Relativistic Positron Jets  

SciTech Connect (OSTI)

Electron-positron jets with MeV temperature are thought to be present in a wide variety of astrophysical phenomena such as active galaxies, quasars, gamma ray bursts and black holes. They have now been created in the laboratory in a controlled fashion by irradiating a gold target with an intense picosecond duration laser pulse. About 10{sup 11} MeV positrons are emitted from the rear surface of the target in a 15 to 22-degree cone for a duration comparable to the laser pulse. These positron jets are quasi-monoenergetic (E/{delta}E {approx} 5) with peak energies controllable from 3-19 MeV. They have temperatures from 1-4 MeV in the beam frame in both the longitudinal and transverse directions. Positron production has been studied extensively in recent decades at low energies (sub-MeV) in areas related to surface science, positron emission tomography, basic antimatter science such as antihydrogen experiments, Bose-Einstein condensed positronium, and basic plasma physics. However, the experimental tools to produce very high temperature positrons and high-flux positron jets needed to simulate astrophysical positron conditions have so far been absent. The MeV temperature jets of positrons and electrons produced in our experiments offer a first step to evaluate the physics models used to explain some of the most energetic phenomena in the universe.

Chen, H; Wilks, S C; Meyerhofer, D D; Bonlie, J; Chen, C D; Chen, S N; Courtois, C; Elberson, L; Gregori, G; Kruer, W; Landoas, O; Mithen, J; Murphy, C; Nilson, P; Price, D; Scheider, M; Shepherd, R; Stoeckl, C; Tabak, M; Tommasini, R; Beiersdorder, P

2009-10-08T23:59:59.000Z

256

Jet energy scale setting with "photon+Jet" events at LHC energies. Selection of events with a clean "photon+Jet" topology and photon Pt - jet Pt disbalance  

E-Print Network [OSTI]

It is shown in the paper that Pt activity limitation (modulus of the vector sum) of all particle beyond "photon+Jet" system Pt^out leads to the noticeable photon Pt - jet Pt disbalance decreasing. On a simultaneous restriction of the cluster Pt and Pt^out from above it is possible to reach an acceptable balance between photon Pt - jet Pt with a sufficient number of the photon Pt - jet Pt events for the jet energy scale setting and hadron calorimeter calibratiom of the CMS detector at LHC.

D. V. Bandourin; V. F. Konoplyanikov; N. B. Skachkov

2001-04-27T23:59:59.000Z

257

Effects of liquid helium bubble formation in a superconducting cavity cryogenic system  

SciTech Connect (OSTI)

We constructed a simple prototype model based on the geometry of the 56 MHz superconducting cavity for RHIC. We studied the formation, in this prototype, of bubbles of liquid helium and their thermal effects on the cavity. We found that due to the low viscosity of the liquid helium, and its small surface tension, no large bubbles formed. The tiny bubbles, generated from most of the area, behaved like light gas travelling in a free space and escaped from the trapping region. The bubbles that were generated in the trapping area, due to its descending geometry, are much bigger than the other bubbles, but due to the liquid flow generated by heating, they still are negligible compared to the size of the trapping region. We expected that the effects of bubbles in our 56 MHz cavity during operation might well be negligible.

Chang, X.; Wang, E.; Xin, T.

2011-03-01T23:59:59.000Z

258

Invention and History of the Bubble Chamber (LBNL Summer Lecture Series)  

ScienceCinema (OSTI)

Summer Lecture Series 2006: Don Glaser won the 1960 Nobel Prize for Physics for his 1952 invention of the bubble chamber at Berkeley Lab, a type of particle detector that became the mainstay of high-energy physics research throughout the 1960s and 1970s. He discusses how, inspired by bubbles in a glass of beer, he invented the bubble chamber and detected cosmic-ray muons.

Glaser, Don

2011-04-28T23:59:59.000Z

259

Buoyancy and Penrose Process Produce Jets from Rotating Black Holes  

E-Print Network [OSTI]

The exact mechanism by which astrophysical jets are formed is still unknown. It is believed that necessary elements are a rotating (Kerr) black hole and a magnetised accreting plasma. We model the accreting plasma as a collection of magnetic flux tubes/strings. If such a tube falls into a Kerr black hole, then the leading portion loses angular momentum and energy as the string brakes, and to compensate for this loss, momentum and energy is redistributed to the trailing portion of the tube.} {We found that buoyancy creates a pronounced helical magnetic field structure aligned with the spin axis. Along the field lines, the plasma is centrifugally accelerated close to the speed of light. This process leads to unlimited stretching of the flux tube since one part of the tube continues to fall into the black hole and simultaneously the other part of the string is pushed outward. Eventually, reconnection cuts the tube, the inner part is filled with new material and the outer part forms a collimated bubble-structured...

Semenov, V S; Heyn, M F

2014-01-01T23:59:59.000Z

260

Synthetic jets at large Reynolds number and comparison to continuous jets  

SciTech Connect (OSTI)

Experimental measurements and flow visualization of synthetic jets and similar continuous jets are described. The dimensionless stroke length necessary to form a 2-D synthetic jet is between 5 and 10, with wider-nozzle jets consistently requiring a smaller value. Synthetic jets are wider, slower and have more momentum than similar continuous jets. Synthetic jets are generated using four nozzle widths that vary by a factor of four, and the driving frequency is varied over an order of magnitude. The resultant jets are in the range 13.5 < L{sub o}/h < 80.8 and 695 < Re{sub Uo} < 14700. In spite of the large range of stroke lengths, the near-field behavior of the synthetic jets scales with L{sub o}/h.

Smith, B. L. (Barton L.); Swift, G. W. (Gregory W.)

2001-01-01T23:59:59.000Z

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.


261

Ultrasonic effect on the bubble nucleation and heat transfer of oscillating nanofluid  

SciTech Connect (OSTI)

Ultrasonic sound effect on bubble nucleation, oscillating motion activated by bubble formation, and its heat transfer enhancement of nanofluid was experimentally investigated. Nanofluid consists of distilled water and dysprosium (III) oxide (Dy{sub 2}O{sub 3}) nanoparticles with an average size of 98?nm and a mass ratio of 0.5%. Visualization results demonstrate that when the nanoparticles are added in the fluid influenced by the ultrasonic sound, bubble nucleation can be significantly enhanced. The oscillating motion initiated by the bubble formation of nanofluid under the influence of ultrasonic sound can significantly enhance heat transfer of nanofluid in an interconnected capillary loop.

Zhao, Nannan; Fu, Benwei [Institute of Marine Engineering and Thermal Science, College of Marine Engineering, Dalian Maritime University, Dalian 116026 (China); Key Laboratory of Marine, Mechanical and Manufacturing Engineering of the Ministry of Transport, Dalian 116026 (China); Ma, H. B., E-mail: mah@missouri.edu [Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, Missouri 65211 (United States)

2014-06-30T23:59:59.000Z

262

E-Print Network 3.0 - anisotropic bubble nucleation Sample Search...  

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

Engineering 11 Colloids and Surfaces A: Physicochem. Eng. Aspects 263 (2005) 336340 Phenomenology of bubble nucleation in the solid-state Summary: December 2004 Available online 3...

263

Generation of laser-induced cavitation bubbles with a digital hologram  

E-Print Network [OSTI]

C. D. Ohl, “Controlled cavitation-cell interaction: trans-R. Dijkink and C. D. Ohl, “Cavitation based micropump,” Labobservations of laser- induced cavitation bubbles in water,”

Quinto-Su, P. A; Venugopalan, V.; Ohl, C.-D.

2008-01-01T23:59:59.000Z

264

E-Print Network 3.0 - air bubble entrainment Sample Search Results  

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

30 June 4, 2010 Summary: . Finally, bubble entrainment and interaction with traveling vortex tube under dilute loadings are simulated... some conditions, the entrainment of eight...

265

Bubbles Help Break Energy Storage Record for Lithium Air-Batteries  

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

Bubbles Help Break Energy Storage Record for Lithium Air-Batteries Foam-base graphene keeps oxygen flowing in batteries that holds promise for electric vehicles January...

266

E-Print Network 3.0 - airlift bubble column Sample Search Results  

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

volumes of air bubbles into the water column, enhancing wave energy dissipation... The air entrainment coefficient cb determines how many ... Source: Kirby, James T. -...

267

E-Print Network 3.0 - air bubbles mimic Sample Search Results  

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

of Engineering, Chaos Research Group Collection: Engineering 6 Effects of intermittent entrainment of air bubbles by breaking wind waves on ocean reflectance and underwater...

268

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

269

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

270

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

271

Next Generation Reactors  

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

Nuclear Advances We are coordinating the Generation IV Nuclear Systems Initiative - an international effort to develop the next generation of nuclear power reactors. Skip...

272

A TEN MEGAWATT BOILING HETEROGENEOUS PACKAGE POWER REACTOR. Reactor...  

Office of Scientific and Technical Information (OSTI)

A TEN MEGAWATT BOILING HETEROGENEOUS PACKAGE POWER REACTOR. Reactor Design and Feasibility Problem Re-direct Destination: Temp Data Fields Rosen, M. A.; Coburn, D. B.; Flynn, T....

273

The formation of gas bubbles at submerged orifices  

E-Print Network [OSTI]

. t - U i ; ? , Volume of Gas Chamber x 10 (cc.) | JO T * | f ? * *** 1 1 4 f 1 | I i ? \\ Fig. 7. Variation of the Bubble Volume with the Volume of the Gas Chamber d m 0.318 cm. 39 relative magnitudes of the terms constituting Equa? tion (25... at the correlations given, the quantity ? (which is proportional to the drag force) was correlated in the same manner as described for ^ ancl Ag. e corre^a^i?ns f?r ? In (E xp er im en ta l va lu e of ~f O In ("V*calculated by use of Equation 33) 8...

Hayes, William Bell

2013-10-04T23:59:59.000Z

274

Hydrogen Bubbles and Formation of Nanoporous Silicon during Electrochemical  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinementEtching. | EMSL Bubbles and Formation of Nanoporous

275

Brookhaven Graphite Research Reactor Workshop  

Broader source: Energy.gov [DOE]

The Brookhaven Graphite Research Reactor (BGRR) was the first reactor built in the U.S. for peacetime atomic research following World War II.  Construction began in 1947 and the reactor started...

276

Portfolio for fast reactor collaboration  

SciTech Connect (OSTI)

The development of the LMFBR type reactor in the United Kingdom is reviewed. Design characteristics of a commercial demonstration fast reactor are presented and compared with the Super Phenix reactor.

Rippon, S.

1981-12-01T23:59:59.000Z

277

Numerical Simulations of Bouncing Jets  

E-Print Network [OSTI]

downhill gliding of the pool, at about 4mm/s of pool surface velocity. . . . . . . . . . . . . . . . . . . . . . 87 viii 5.7 Overall view of the shampoo jet bouncing of an inclined pool of the same liquid. The white arrow points at he breakup of the air....4 Time discretization . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 3.5 Entropy residual stabilization . . . . . . . . . . . . . . . . . . . . . . 58 3.6 Adaptive mesh refinement . . . . . . . . . . . . . . . . . . . . . . . . 61 iv 3.7...

Lee, Sanghyun

2014-07-18T23:59:59.000Z

278

Fluid jet electric discharge source  

DOE Patents [OSTI]

A fluid jet or filament source and a pair of coaxial high voltage electrodes, in combination, comprise an electrical discharge system to produce radiation and, in particular, EUV radiation. The fluid jet source is composed of at least two serially connected reservoirs, a first reservoir into which a fluid, that can be either a liquid or a gas, can be fed at some pressure higher than atmospheric and a second reservoir maintained at a lower pressure than the first. The fluid is allowed to expand through an aperture into a high vacuum region between a pair of coaxial electrodes. This second expansion produces a narrow well-directed fluid jet whose size is dependent on the size and configuration of the apertures and the pressure used in the reservoir. At some time during the flow of the fluid filament, a high voltage pulse is applied to the electrodes to excite the fluid to form a plasma which provides the desired radiation; the wavelength of the radiation being determined by the composition of the fluid.

Bender, Howard A. (Ripon, CA)

2006-04-25T23:59:59.000Z

279

REACTOR OPERATIONS AND CONTROL  

E-Print Network [OSTI]

REACTOR OPERATIONS AND CONTROL KEYWORDS: core calculations, neural networks, control rod elevation of a control rod, or a group of control rods, is an important parameter from the viewpoint of reactor control DETERMINATION OF PWR CONTROL ROD POSITION BY CORE PHYSICS AND NEURAL NETWORK METHODS NINOS S. GARIS* and IMRE

Pázsit, Imre

280

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

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

Combining Resummed Higgs Predictions Across Jet Bins  

E-Print Network [OSTI]

Experimental analyses often use jet binning to distinguish between different kinematic regimes and separate contributions from background processes. To accurately model theoretical uncertainties in these measurements, a consistent description of the jet bins is required. We present a complete framework for the combination of resummed results for production processes in different exclusive jet bins, focusing on Higgs production in gluon fusion as an example. We extend the resummation of the Higgs + 1-jet cross section into the challenging low transverse momentum region, lowering the uncertainties considerably. We provide combined predictions with resummation for cross sections in the Higgs + 0-jet and Higgs + 1-jet bins, and give an improved theory covariance matrix for use in experimental studies. We estimate that the relevant theoretical uncertainties on the signal strength in the Higgs to WW analysis are reduced by nearly a factor of 2 compared to the current value.

Radja Boughezal; Xiaohui Liu; Frank Petriello; Frank J. Tackmann; Jonathan R. Walsh

2013-12-16T23:59:59.000Z

282

Reactor & Nuclear Systems Publications | ORNL  

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

Nuclear Science Home | Science & Discovery | Nuclear Science | Publications and Reports | Reactor and Nuclear Systems Publications SHARE Reactor and Nuclear Systems Publications...

283

Reed Reactor Facility. Final report  

SciTech Connect (OSTI)

This report discusses the operation and maintenance of the Reed Reactor Facility. The Reed reactor is mostly used for education and train purposes.

Frantz, S.G.

1994-12-31T23:59:59.000Z

284

Study of bubble growth in water pool boiling through synchronized, infrared thermometry and high-speed video  

E-Print Network [OSTI]

High-speed video and infrared thermometry were used to obtain time- and space-resolved information on bubble nucleation and heat transfer in pool boiling of water. The bubble departure diameter and frequency, growth and ...

Gerardi, Craig

285

GLOBAL EXISTENCE FOR A TRANSLATING NEAR-CIRCULAR HELE-SHAW BUBBLE WITH SURFACE TENSION  

E-Print Network [OSTI]

GLOBAL EXISTENCE FOR A TRANSLATING NEAR-CIRCULAR HELE-SHAW BUBBLE WITH SURFACE TENSION J. YE1 AND S for any nonzero surface tension despite the fact that a local planar approximation near the front problem, Dissipative equations, Hele-Shaw prob- lem, Translating bubbles, Surface tension Mathematics

Tanveer, Saleh

286

Extreme organic carbon burial fuels intense methane bubbling in a temperate reservoir  

E-Print Network [OSTI]

Extreme organic carbon burial fuels intense methane bubbling in a temperate reservoir Sebastian. Wehrli (2012), Extreme organic carbon burial fuels intense methane bubbling in a temperate reservoir; revised 25 November 2011; accepted 30 November 2011; published 4 January 2012. [1] Organic carbon (OC

Wehrli, Bernhard

287

Electrokinetic displacement of air bubbles in microchannels Pavlo Takhistov, Alexandra Indeikina, and Hsueh-Chia Chang  

E-Print Network [OSTI]

and further reduces film flow. Within a large window in the total ionic concentration Ct , these mechanisms a higher relative film conductivity. The bubble velocity within the above concentration window is captured is shown to be possible when the film flow around the bubble is less than the bulk flow behind it. In our

Chang, Hsueh-Chia

288

Plasma Line Emission during Single-Bubble Cavitation David J. Flannigan and Kenneth S. Suslick*  

E-Print Network [OSTI]

Plasma Line Emission during Single-Bubble Cavitation David J. Flannigan and Kenneth S. Suslick-bubble cavitation in sulfuric acid are reported. The excited states responsible for these emission lines range 8.3 e the plasma generated during cavitation is comprised of highly energetic particles. DOI: 10.1103/Phys

Suslick, Kenneth S.

289

Luminescence from acoustic-driven laser-induced cavitation bubbles Claus-Dieter Ohl*  

E-Print Network [OSTI]

Luminescence from acoustic-driven laser-induced cavitation bubbles Claus-Dieter Ohl* Drittes and on the cavitation luminescence of a transient laser-induced bubble is investigated experimentally. The variation.60.Mq, 47.55.Bx, 47.55.Dz A vast concentration of energy occurs during the collapse of a cavitation

Ohl, Claus-Dieter

290

Water-Splitting Photoelectrolysis Reaction Rate via Microscopic Imaging of Evolved Oxygen Bubbles  

E-Print Network [OSTI]

to directly split water in a semiconductor photoelectrochemical cell is a promising source of carbon-free fuel Institute of Technology, Pasadena, California 91125, USA Bubble formation and growth on a water of the gas-evolving reaction rate. Optical microscopy was used to record the bubble growth on single

Atwater, Harry

291

The role of colloidal particles on the migration of air bubbles in porous media  

E-Print Network [OSTI]

into account the movement of air bubbles and colloidal particle capture on discrete air-water interface. Generally colloidal particles are treated as suspended particles in the water, so the hypothesis is that the rising air bubble can collect the particles...

Han, Ji-seok

2009-05-15T23:59:59.000Z

292

Impact of boundaries on velocity profiles in bubble rafts Yuhong Wang, Kapilanjan Krishan, and Michael Dennin  

E-Print Network [OSTI]

92697-4575 (Dated: November 7, 2005) Under conditions of sufficiently slow flow, foams, colloids, and an important issue in these systems is the role of the confining boundaries. For foams, three basic systems); and confined bubble rafts (bubbles confined between the surface of water below and a glass plate on top). Often

Dennin, Michael

293

LDV Measurement of Confined Parallel Jet Mixing  

SciTech Connect (OSTI)

Laser Doppler Velocimetry (LDV) measurements were taken in a confinement, bounded by two parallel walls, into which issues a row of parallel jets. Two-component measurements were taken of two mean velocity components and three Reynolds stress components. As observed in isolated three dimensional wall bounded jets, the transverse diffusion of the jets is quite large. The data indicate that this rapid mixing process is due to strong secondary flows, transport of large inlet intensities and Reynolds stress anisotropy effects.

R.F. Kunz; S.W. D'Amico; P.F. Vassallo; M.A. Zaccaria

2001-01-31T23:59:59.000Z

294

Jet physics in Run 2 at CDF  

SciTech Connect (OSTI)

New CDF Run 2 results on the inclusive jet cross section (K{sub T} algorithm) and the b-jet cross section (MidPoint algorithm) are presented and compared with theory. We also study the ''underlying event'' by using the direction of the leading jet to isolate regions of {eta}-{phi} space that are very sensitive to the ''beam-beam'' remnants and to multiple parton interactions.

Field, R.; /Florida U.

2005-01-01T23:59:59.000Z

295

Camera Inspection Arm for Boiling Water Reactors - 13330  

SciTech Connect (OSTI)

Boiling Water Reactor (BWR) outage maintenance tasks can be time-consuming and hazardous. Reactor facilities are continuously looking for quicker, safer, and more effective methods of performing routine inspection during these outages. In 2011, S.A. Technology (SAT) was approached by Energy Northwest to provide a remote system capable of increasing efficiencies related to Reactor Pressure Vessel (RPV) internal inspection activities. The specific intent of the system discussed was to inspect recirculation jet pumps in a manner that did not require manual tooling, and could be performed independently of other ongoing inspection activities. In 2012, SAT developed a compact, remote, camera inspection arm to create a safer, more efficient outage environment. This arm incorporates a compact and lightweight design along with the innovative use of bi-stable composite tubes to provide a six-degree of freedom inspection tool capable of reducing dose uptake, reducing crew size, and reducing the overall critical path for jet pump inspections. The prototype camera inspection arm unit is scheduled for final testing in early 2013 in preparation for the Columbia Generating Station refueling outage in the spring of 2013. (authors)

Martin, Scott; Rood, Marc [S.A. Technology, 3985 S. Lincoln Ave, Loveland, CO 80537 (United States)] [S.A. Technology, 3985 S. Lincoln Ave, Loveland, CO 80537 (United States)

2013-07-01T23:59:59.000Z

296

Nuclear Composition of Magnetized GRB Jets  

E-Print Network [OSTI]

We investigate the fraction of metal nuclei in the relativistic jets of gamma-ray bursts associated with core-collapse supernovae. We simulate the fallback in jet-induced explosions with two-dimensional relativistic hydrodynamics calculations and the jet acceleration with steady, radial, relativistic magnetohydrodynamics calculations, and derive detail nuclear composition of the jet by postprocessing calculation. We found that if the temperature at the jet launch site is above $4.7\\times 10^9$K, quasi-statistical equilibrium (QSE) is established and heavy nuclei are dissociated to light particles such as $^4$He during the acceleration of the jets. The criterion for the survival of metal nuclei is written in terms of the isotropic jet luminosity as $L_{\\rm j}^{\\rm iso} \\lesssim 3.9\\times 10^{50}(R_{\\rm i}/10^7{\\rm cm})^2 (1+\\sigma_{\\rm i})~{\\rm erg~s^{-1}}$, where $R_{\\rm i}$ and $\\sigma_{\\rm i}$ are the initial radius of the jets and the initial magnetization parameter, respectively. If the jet is initially d...

Shibata, Sanshiro

2015-01-01T23:59:59.000Z

297

PHYSICAL PARAMETERS OF STANDARD AND BLOWOUT JETS  

SciTech Connect (OSTI)

The X-ray Telescope on board the Hinode mission revealed the occurrence, in polar coronal holes, of much more numerous jets than previously indicated by the Yohkoh/Soft X-ray Telescope. These plasma ejections can be of two types, depending on whether they fit the standard reconnection scenario for coronal jets or if they include a blowout-like eruption. In this work, we analyze two jets, one standard and one blowout, that have been observed by the Hinode and STEREO experiments. We aim to infer differences in the physical parameters that correspond to the different morphologies of the events. To this end, we adopt spectroscopic techniques and determine the profiles of the plasma temperature, density, and outflow speed versus time and position along the jets. The blowout jet has a higher outflow speed, a marginally higher temperature, and is rooted in a stronger magnetic field region than the standard event. Our data provide evidence for recursively occurring reconnection episodes within both the standard and the blowout jet, pointing either to bursty reconnection or to reconnection occurring at different locations over the jet lifetimes. We make a crude estimate of the energy budget of the two jets and show how energy is partitioned among different forms. Also, we show that the magnetic energy that feeds the blowout jet is a factor of 10 higher than the magnetic energy that fuels the standard event.

Pucci, Stefano; Romoli, Marco [Department of Physics and Astronomy, University of Firenze, I-50121 Firenze (Italy); Poletto, Giannina [INAF-Arcetri Astrophysical Observatory, I-50125 Firenze (Italy); Sterling, Alphonse C., E-mail: stpucci@arcetri.astro.it [Space Science Office, NASA/MSFC, Huntsville, Al 35812 (United States)

2013-10-10T23:59:59.000Z

298

Drying characteristics of slot jet reattachment nozzle and comparison with a slot jet nozzle  

E-Print Network [OSTI]

the same flow power and flow exerted surface peak pressure. The same flow power results showed that +45[] and +20[] SJR nozzles performed better than the slot jet nozzle, while the 0[] SJR had drying characteristics similar to the slot jet. The slot jet...

Alam, Syed Aftab

2012-06-07T23:59:59.000Z

299

A numerical study of mass transfer of ozone dissolution in bubble plumes with an Euler-Lagrange Method  

E-Print Network [OSTI]

, as a model problem for a water purification system. The effect of bubble diameter and plume structure on mass are widely observed and exploited in engineering applications, with water purification using ozone bubble the mass transfer process of ozone dissolution in a bubble plume inside a rectangular water tank

Huang, Huaxiong

300

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,
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

Nuclear reactor control column  

SciTech Connect (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 crosssectional 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, D.M.

1982-08-10T23:59:59.000Z

302

Reactor Safety Research Programs  

SciTech Connect (OSTI)

This document summarizes the work performed by Pacific Northwest Laboratory (PNL) from January 1 through March 31, 1981, for the Division of Reactor Safety Research within the U.S. Nuclear Regulatory Commission (NRC). Evaluations of nondestructive examination (NDE) techniques and instrumentation are reported; areas of investigation include demonstrating the feasibility of determining the strength of structural graphite, evaluating the feasibility of detecting and analyzing flaw growth in reactor pressure boundary systems, examining NDE reliability and probabilistic fracture mechanics, and assessing the integrity of pressurized water reactor (PWR) steam generator tubes where service-induced degradation has been indicated. Experimental data and analytical models are being provided to aid in decision-making regarding pipeto- pipe impacts following postulated breaks in high-energy fluid system piping. Core thermal models are being developed to provide better digital codes to compute the behavior of full-scale reactor systems under postulated accident conditions. Fuel assemblies and analytical support are being provided for experimental programs at other facilities. These programs include loss-ofcoolant accident (LOCA) simulation tests at the NRU reactor, Chalk River, Canada; fuel rod deformation, severe fuel damage, and postaccident coolability tests for the ESSOR reactor Super Sara Test Program, Ispra, Italy; the instrumented fuel assembly irradiation program at Halden, Norway; and experimental programs at the Power Burst Facility, Idaho National Engineering Laboratory (INEL). These programs will provide data for computer modeling of reactor system and fuel performance during various abnormal operating conditions.

Edler, S. K.

1981-07-01T23:59:59.000Z

303

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

304

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

305

Fast Breeder Reactor studies  

SciTech Connect (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

306

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

307

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

308

Space variations in axis height of the jet stream core  

E-Print Network [OSTI]

height of the jet axis relative to the height of the jet maximum for slow vs. fast cases. 13 Mean height of the jet axis relative to the height at the trough. 13 Mean height of the jet axis relative to the height at the ridge. 15 Mean height... of the jet axis relative to the height at the jet maximum, when the maximum is near a trough. 15 Mean height of the jet axis relative to the height at the minimum, when the minimum is near a ridge. 17 Mean height of the jet axis relative to the height...

Leutwyler, Cooke Hearon

1965-01-01T23:59:59.000Z

309

Why Do Disks Form Jets?  

E-Print Network [OSTI]

It is argued that jet modelers have given insufficient study to the natural magneto-static configurations of field wound up in the presence of a confining general pressure. Such fields form towers whose height grows with each twist at a velocity comparable to the circular velocity of the accretion disk that turns them. A discussion of the generation of such towers is preceded by a brief history of the idea that quasars, active galaxies, and galactic nuclei contain giant black holes with accretion disks.

D Lynden-Bell

2002-03-27T23:59:59.000Z

310

Reactor hot spot analysis  

SciTech Connect (OSTI)

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

311

P Reactor Grouting  

SciTech Connect (OSTI)

Filling the P Reactor with grout. This seals the radioactive material and reduces the environmental footprint left from the Cold War. Project sponsored by the Recovery Act at the Savannah River Site.

None

2010-01-01T23:59:59.000Z

312

Miniconference on astrophysical jets P. M. Bellan  

E-Print Network [OSTI]

and numerical modelers of both astrophysical jets and spheromaks, and laboratory experimentalists. The purpose-organization. Spheromaks have been studied for the last two decades and most recently, it has been realized that the physics of spheromak formation has much in common with magnetohydrodynamically driven astrophysical jets

Bellan, Paul M.

313

Jet multiplicities as the QGP thermometer  

E-Print Network [OSTI]

It is proposed to use the energy behavior of mean multiplicities of jets propagating in a nuclear medium as the thermometer of this medium during the collision phases. The qualitative effects are demonstrated in the framework of the fixed coupling QCD with account of jet quenching.

I. M. Dremin; O. S. Shadrin

2006-02-10T23:59:59.000Z

314

Nuclear reactor control  

SciTech Connect (OSTI)

A liquid metal cooled fast breeder nuclear reactor has power setback means for use in an emergency. On initiation of a trip-signal a control rod is injected into the core in two stages, firstly, by free fall to effect an immediate power-set back to a safe level and, secondly, by controlled insertion. Total shut-down of the reactor under all emergencies is avoided. 4 claims.

Ingham, R.V.

1980-01-01T23:59:59.000Z

315

Polymerization reactor control  

SciTech Connect (OSTI)

The principal difficulties in achieving good control of polymerization reactors are related to inadequate on-line measurement, a lack of understanding of the dynamics of the process, the highly sensitive and nonlinear behavior of these reactors, and the lack of well-developed techniques for the control of nonlinear processes. Some illustrations of these problems and a discussion of potential techniques for overcoming some of these difficulties is provided.

Ray, W.H.

1985-01-01T23:59:59.000Z

316

Molten metal reactors  

DOE Patents [OSTI]

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

317

F Reactor Inspection  

SciTech Connect (OSTI)

Workers from Mission Support Alliance, LLC., removed the welds around the steel door of the F Reactor before stepping inside the reactor to complete its periodic inspection. This is the first time the Department of Energy (DOE) has had the reactor open since 2008. The F Reactor is one of nine reactors along the Columbia River at the Department's Hanford Site in southeastern Washington State, where environmental cleanup has been ongoing since 1989. As part of the Tri-Party Agreement, the Department completes surveillance and maintenance activities of cocooned reactors periodically to evaluate the structural integrity of the safe storage enclosure and to ensure confinement of any remaining hazardous materials. "This entry marks a transition of sorts because the Hanford Long-Term Stewardship Program, for the first time, was responsible for conducting the entry and surveillance and maintenance activities," said Keith Grindstaff, Energy Department Long-Term Stewardship Program Manager. "As the River Corridor cleanup work is completed and transitioned to long-term stewardship, our program will manage any on-going requirements."

Grindstaff, Keith; Hathaway, Boyd; Wilson, Mike

2014-10-29T23:59:59.000Z

318

Reactor Safety Research Programs  

SciTech Connect (OSTI)

This document summarizes the work performed by Pacific Northwest laboratory from October 1 through December 31, 1979, for the Division of Reactor Safety Research within the Nuclear Regulatory Commission. Evaluation of nondestructive examination (NDE) techniques and instrumentation are reported; areas of investigation include demonstrating the feasibilty of determining structural graphite strength, evaluating the feasibilty of detecting and analyzing flaw growth in reactor pressure boundary systems, examining NDE reliability and probabilistic fracture mechanics, and assessing the remaining integrity of pressurized water reactor steam generator tubes where service-induced degradation has been indicated. Test assemblies and analytical support are being provided for experimental programs at other facilities. These programs include the loss-of-coolant accident simulation tests at the NRU reactor, Chalk River, Canada; the fuel rod deformation and post-accident coolability tests for the ESSOR Test Reactor Program, lspra, Italy; the blowdown and reflood tests in the test facility at Cadarache, France; the instrumented fuel assembly irradiation program at Halden, Norway; and the experimental programs at the Power Burst Facility, Idaho National Engineering Laboratory. These programs will provide data for computer modeling of reactor system and fuel performance during various abnormal operating conditions.

Dotson, CW

1980-08-01T23:59:59.000Z

319

F Reactor Inspection  

ScienceCinema (OSTI)

Workers from Mission Support Alliance, LLC., removed the welds around the steel door of the F Reactor before stepping inside the reactor to complete its periodic inspection. This is the first time the Department of Energy (DOE) has had the reactor open since 2008. The F Reactor is one of nine reactors along the Columbia River at the Department's Hanford Site in southeastern Washington State, where environmental cleanup has been ongoing since 1989. As part of the Tri-Party Agreement, the Department completes surveillance and maintenance activities of cocooned reactors periodically to evaluate the structural integrity of the safe storage enclosure and to ensure confinement of any remaining hazardous materials. "This entry marks a transition of sorts because the Hanford Long-Term Stewardship Program, for the first time, was responsible for conducting the entry and surveillance and maintenance activities," said Keith Grindstaff, Energy Department Long-Term Stewardship Program Manager. "As the River Corridor cleanup work is completed and transitioned to long-term stewardship, our program will manage any on-going requirements."

Grindstaff, Keith; Hathaway, Boyd; Wilson, Mike

2014-11-24T23:59:59.000Z

320

On He bubbles in neutron irradiated SYLRAMIC type SiC fibers  

SciTech Connect (OSTI)

SylramicTM type SiC fibers, which contain at least 2.3 wt% B, were examined by TEM following neutron irradiation to dose levels of ~7 dpa in HFIR at 800°C and to ~1 dpa in ATR at 1090°C. At these radiation damage dose levels, transmutation of the boron-10 component effectively “dopes” the Sylramic? type fibers with up to 10,000 appm helium. Following irradiation at 800°C, bubble development was too fine to resolve even by high resolution TEM. However, following irradiation at 1090°C helium bubble development was resolvable, but complex. A fine dispersion of 1-nm bubbles was observed within the SiC grains and a coarse, non-uniform distribution of irregular 25-nm bubbles was observed on grain boundaries. In addition, some unusual arrays of planar 2.5-nm thick bubbles were observed in the SiC grains and equiaxed bubbles were observed in the boride precipitate particles contained within the fiber microstructure. Not unexpectedly, helium retention and bubble formation in ?-SiC depends on details of the polycrystalline microstructure as well as the irradiation conditions.

Gelles, David S.; Youngblood, Gerald E.

2006-03-01T23:59:59.000Z

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.


321

Molecular Dynamics Simulation of Cascade-Induced Ballistic Helium Resolutioning from Bubbles in Iron  

SciTech Connect (OSTI)

Molecular dynamics simulations have been used to assess the ability of atomic displacement cascades to eject helium from small bubbles in iron. This study of the ballistic resolutioning mechanism employed a recently-developed Fe-He interatomic potential in concert with an iron potential developed by Ackland and co-workers. The primary variables examined were: irradiation temperature (100 and 600K), cascade energy (5 and 20 keV), bubble radius (0.5 and 1.0 nm), and He-to-vacancy ratio in the bubble (0.25, 0.5 and 1.0). Systematic trends were observed for each of these variables. For example, ballistic resolutioning leads to a greater number of helium atoms being displaced from larger bubbles and from bubbles that have a higher He/vacancy ratio (bubble pressure). He resolutioning was reduced at 600K relative to 100K, and for 20 keV cascades relative to 5 keV cascades. Overall, the results indicate a modest level of He removal by ballistic resolutioning. The results can be used to provide guidance in selection of a resolution parameter that can be employed in cluster dynamics models to predict the bubble size distribution that evolves under irradiation.

Stoller, Roger E [ORNL] [ORNL

2013-01-01T23:59:59.000Z

322

$W/Z$ + jets results from CDF  

SciTech Connect (OSTI)

The CDF Collaboration has a comprehensive program of studying the production of vector bosons, W and Z, in association with energetic jets. Excellent understanding of the standard model W/Z+jets and W/Z+c,b-jets processes is of paramount importance for the top quark physics and for the Higgs boson and many new physics searches. We review the latest CDF results on Z-boson production in association with inclusive and b-quark jets, study of the p{sub T} balance in Z+jet events, and a measurement of the W+charm production cross section. The results are based on 4-5 fb{sup -1} of data and compared to various Monte Carlo and next-to-leading order perturbative QCD predictions.

Camarda, Stefano; /Barcelona, IFAE

2010-01-01T23:59:59.000Z

323

Coalescence of bubbles and drops in an outer fluid  

E-Print Network [OSTI]

When two liquid drops touch, a microscopic connecting liquid bridge forms and rapidly grows as the two drops merge into one. Whereas coalescence has been thoroughly studied when drops coalesce in vacuum or air, many important situations involve coalescence in a dense surrounding fluid, such as oil coalescence in brine. Here we study the merging of gas bubbles and liquid drops in an external fluid. Our data indicate that the flows occur over much larger length scales in the outer fluid than inside the drops themselves. Thus we find that the asymptotic early regime is always dominated by the viscosity of the drops, independent of the external fluid. A phase diagram showing the crossovers into the different possible late-time dynamics identifies a dimensionless number that signifies when the external viscosity can be important.

Joseph D. Paulsen; Rémi Carmigniani; Anerudh Kannan; Justin C. Burton; Sidney R. Nagel

2014-07-24T23:59:59.000Z

324

Mechanical Feedback: From stellar wind bubbles to starbursts  

E-Print Network [OSTI]

The current understanding of mechanical feedback is reviewed by evaluating the standard, adiabatic model for shell formation and evolution. This model is relevant to phenomena ranging from individual stellar-wind bubbles to galactic superwinds, forming the basis for our understanding of the multiphase ISM, IGM, and galactic evolutionary processes. Although significant discrepancies between the model and observation have been identified, to date there are none that require a fundamental revision. A variety of evidence, ranging over three orders of magnitude in spatial scale, is broadly consistent with the standard model. This includes kinematics of individual objects, observations of hot gas, the size distribution of HI shells, and outflow rates from starburst galaxies. However, some of the most pressing issues relating to shell evolution are still outstanding and obstruct efforts to resolve key questions like the fate of the hot gas.

M. S. Oey; C. J. Clarke; P. Massey

2001-03-20T23:59:59.000Z

325

Bubble formation in reservoir fluids at low supersaturations  

E-Print Network [OSTI]

reservoir cox'e, oil and gca obtcfned directly from the Ranf;oly Field in Color: Co, &cod mounted the core in ' Gap'"cr afz'ilier to the coro tlountiflf' re' orted in this ~mr%, Tho oil:nd g:. a ~me reconMned:n the 1abora- tory uith u bubble point ox lg...;te rrd one ron thc c!;-ber ho using, vere coi. "ected to a c ~urce 'f 9. C, current crx'. tc s circuit br+, l. cr &Nicli rc:. iiyc'. ll c. illic-~ores to operate !Lon the v; lvc sto M. ached ti;e pl. ". te the electrical circuit vo 1~'. be closed ~nd...

Wieland, Denton R

1956-01-01T23:59:59.000Z

326

Possible Bubbles of Spacetime Curvature in the South Pacific  

E-Print Network [OSTI]

In 1928, the late Francis Wayland Thurston published a scandalous manuscript in purport of warning the world of a global conspiracy of occultists. Among the documents he gathered to support his thesis was the personal account of a sailor by the name of Gustaf Johansen, describing an encounter with an extraordinary island. Johansen`s descriptions of his adventures upon the island are fantastic, and are often considered the most enigmatic (and therefore the highlight) of Thurston`s collection of documents. We contend that all of the credible phenomena which Johansen described may be explained as being the observable consequences of a localized bubble of spacetime curvature. Many of his most incomprehensible statements (involving the geometry of the architecture, and variability of the location of the horizon) can therefore be said to have a unified underlying cause. We propose a simplified example of such a geometry, and show using numerical computation that Johansen`s descriptions were, for the most part, not ...

Tippett, Benjamin K

2012-01-01T23:59:59.000Z

327

Atmospheric-pressure plasma jet  

DOE Patents [OSTI]

Atmospheric-pressure plasma jet. A .gamma.-mode, resonant-cavity plasma discharge that can be operated at atmospheric pressure and near room temperature using 13.56 MHz rf power is described. Unlike plasma torches, the discharge produces a gas-phase effluent no hotter than 250.degree. C. at an applied power of about 300 W, and shows distinct non-thermal characteristics. In the simplest design, two concentric cylindrical electrodes are employed to generate a plasma in the annular region therebetween. A "jet" of long-lived metastable and reactive species that are capable of rapidly cleaning or etching metals and other materials is generated which extends up to 8 in. beyond the open end of the electrodes. Films and coatings may also be removed by these species. Arcing is prevented in the apparatus by using gas mixtures containing He, which limits ionization, by using high flow velocities, and by properly shaping the rf-powered electrode. Because of the atmospheric pressure operation, no ions survive for a sufficiently long distance beyond the active plasma discharge to bombard a workpiece, unlike low-pressure plasma sources and conventional plasma processing methods.

Selwyn, Gary S. (Los Alamos, NM)

1999-01-01T23:59:59.000Z

328

Can Protostellar Jets Drive Supersonic Turbulence in Molecular Clouds?  

E-Print Network [OSTI]

Jets and outflows from young stellar objects are proposed candidates to drive supersonic turbulence in molecular clouds. Here, we present the results from multi-dimensional jet simulations where we investigate in detail the energy and momentum deposition from jets into their surrounding environment and quantify the character of the excited turbulence with velocity probability density functions. Our study include jet--clump interaction, transient jets, and magnetised jets. We find that collimated supersonic jets do not excite supersonic motions far from the vicinity of the jet. Supersonic fluctuations are damped quickly and do not spread into the parent cloud. Instead subsonic, non-compressional modes occupy most of the excited volume. This is a generic feature which can not be fully circumvented by overdense jets or magnetic fields. Nevertheless, jets are able to leave strong imprints in their cloud structure and can disrupt dense clumps. Our results question the ability of collimated jets to sustain supersonic turbulence in molecular clouds.

Robi Banerjee; Ralf S. Klessen; Christian Fendt

2007-06-25T23:59:59.000Z

329

An inkjet vision measurement technique for high-frequency jetting  

SciTech Connect (OSTI)

Inkjet technology has been used as manufacturing a tool for printed electronics. To increase the productivity, the jetting frequency needs to be increased. When using high-frequency jetting, the printed pattern quality could be non-uniform since the jetting performance characteristics including the jetting speed and droplet volume could vary significantly with increases in jet frequency. Therefore, high-frequency jetting behavior must be evaluated properly for improvement. However, it is difficult to measure high-frequency jetting behavior using previous vision analysis methods, because subsequent droplets are close or even merged. In this paper, we present vision measurement techniques to evaluate the drop formation of high-frequency jetting. The proposed method is based on tracking target droplets such that subsequent droplets can be excluded in the image analysis by focusing on the target droplet. Finally, a frequency sweeping method for jetting speed and droplet volume is presented to understand the overall jetting frequency effects on jetting performance.

Kwon, Kye-Si, E-mail: kskwon@sch.ac.kr; Jang, Min-Hyuck; Park, Ha Yeong [Department of Mechanical Engineering, Soonchunhyang University 22, Soonchunhyang-Ro, Shinchang, Asan Chungnam 336-745 (Korea, Republic of); Ko, Hyun-Seok [Department of Electrical and Robot Engineering, Soonchunhyang University, 22, Soonchunhyang-Ro, Shinchang, Asan Chungnam 336-745 (Korea, Republic of)

2014-06-15T23:59:59.000Z

330

THE FERMI BUBBLES AS A SCALED-UP VERSION OF SUPERNOVA REMNANTS  

SciTech Connect (OSTI)

In this study, we treat Fermi bubbles as a scaled-up version of supernova remnants (SNRs). The bubbles are created through activities of the super-massive black hole (SMBH) or starbursts at the Galactic center (GC). Cosmic-rays (CRs) are accelerated at the forward shocks of the bubbles like SNRs, which means that we cannot decide whether the bubbles were created by the SMBH or starbursts from the radiation from the CRs. We follow the evolution of CR distribution by solving a diffusion-advection equation, considering the reduction of the diffusion coefficient by CR streaming. In this model, gamma rays are created through hadronic interaction between CR protons and the gas in the Galactic halo. In the GeV band, we can well reproduce the observed flat distribution of gamma-ray surface brightness because some amount of gas is left behind the shock. The edge of the bubbles is fairly sharp owing to the high gas density behind the shock and the reduction of the diffusion coefficient there. The latter also contributes the hard gamma-ray spectrum of the bubbles. We find that the CR acceleration at the shock began when the bubbles were small, and the time scale of the energy injection at the GC was much smaller than the age of the bubbles. We predict that if CRs are accelerated to the TeV regime, the apparent bubble size should be larger in the TeV band, which could be used to discriminate our hadronic model from other leptonic models. We also present neutrino fluxes.

Fujita, Yutaka [Department of Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)] [Department of Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Ohira, Yutaka; Yamazaki, Ryo, E-mail: fujita@vega.ess.sci.osaka-u.ac.jp [Department of Physics and Mathematics, Aoyama Gakuin University, Fuchinobe, Chuou-ku, Sagamihara 252-5258 (Japan)] [Department of Physics and Mathematics, Aoyama Gakuin University, Fuchinobe, Chuou-ku, Sagamihara 252-5258 (Japan)

2013-09-20T23:59:59.000Z

331

HYLIFE-II inertial confinement fusion reactor design  

SciTech Connect (OSTI)

The HYLIFE-2 inertial fusion power plant design study uses a liquid fall, in the form of jets to protect the first structural wall from neutron damage, x rays, and blast to provide a 30-y lifetime. HYLIFE-1 used liquid lithium. HYLIFE 2 avoids the fire hazard of lithium by using a molten salt composed of fluorine, lithium, and beryllium (Li{sub 2}BeF{sub 4}) called Flibe. Access for heavy-ion beams is provided. Calculations for assumed heavy-ion beam performance show a nominal gain of 70 at 5 MJ producing 350 MJ, about 5.2 times less yield than the 1.8 GJ from a driver energy of 4.5 MJ with gain of 400 for HYLIFE-1. The nominal 1 GWe of power can be maintained by increasing the repetition rate by a factor of about 5.2, from 1.5 to 8 Hz. A higher repetition rate requires faster re-establishment of the jets after a shot, which can be accomplished in part by decreasing the jet fall height and increasing the jet flow velocity. Multiple chambers may be required. In addition, although not considered for HYLIFE-1, there is undoubtedly liquid splash that must be forcibly cleared because gravity is too slow, especially at high repetition rates. Splash removal can be accomplished by either pulsed or oscillating jet flows. The cost of electricity is estimated to be 0.09 $/kW{center dot}h in constant 1988 dollars, about twice that of future coal and light water reactor nuclear power. The driver beam cost is about one-half the total cost. 15 refs., 9 figs., 3 tabs.

Moir, R.W.

1990-12-14T23:59:59.000Z

332

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

SciTech Connect (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

333

Oxygen quenching in LAB based liquid scintillator and nitrogen bubbling model  

E-Print Network [OSTI]

The oxygen quenching effect in Linear Alkl Benzne (LAB) based liquid scintillator (LAB as the solvent, 3 g/L 2, 5 diphe-nyloxazole (PPO) as the fluor and 15 mg/L $p$-bis-($o$-methylstyryl)-benzene (bis-MSB) as the $\\lambda$-shifter) is studied by measuring the light yield as the function of the nitrogen bubbling time. It is shown that the light yield of the fully purged liquid scintillator is increased by 11% at the room temperature and the room atmosphere pressure. A simple nitrogen bubbling model is proposed to describe the relationship between the relative light yield (oxygen quenching factor) and the bubbling time.

Xiao Hua-Lin

2009-04-08T23:59:59.000Z

334

Analytic model of electromagnetic fields around a plasma bubble in the blow-out regime  

SciTech Connect (OSTI)

An analytic model of the electric and magnetic fields surrounding the nonlinear plasma 'bubble' formed around the high-current electron bunch in a plasma wakefield accelerator is developed. The model, justified by the results of particle-in-cell simulations, accurately captures the thin high-density plasma sheath and extended return current layer surrounding the bubble. The resulting global fields inside and outside the bubble are used to investigate electron self-injection in a plasma with a smooth density gradient. It is shown that accurate description of the current/density sheaths is crucial for quantitative description of self-injection.

Yi, S. A.; Khudik, V.; Siemon, C.; Shvets, G. [Department of Physics and Institute for Fusion Studies, University of Texas, Austin, Texas 78712 (United States)

2013-01-15T23:59:59.000Z

335

REACTOR GROUT THERMAL PROPERTIES  

SciTech Connect (OSTI)

Savannah River Site has five dormant nuclear production reactors. Long term disposition will require filling some reactor buildings with grout up to ground level. Portland cement based grout will be used to fill the buildings with the exception of some reactor tanks. Some reactor tanks contain significant quantities of aluminum which could react with Portland cement based grout to form hydrogen. Hydrogen production is a safety concern and gas generation could also compromise the structural integrity of the grout pour. Therefore, it was necessary to develop a non-Portland cement grout to fill reactors that contain significant quantities of aluminum. Grouts generate heat when they set, so the potential exists for large temperature increases in a large pour, which could compromise the integrity of the pour. The primary purpose of the testing reported here was to measure heat of hydration, specific heat, thermal conductivity and density of various reactor grouts under consideration so that these properties could be used to model transient heat transfer for different pouring strategies. A secondary purpose was to make qualitative judgments of grout pourability and hardened strength. Some reactor grout formulations were unacceptable because they generated too much heat, or started setting too fast, or required too long to harden or were too weak. The formulation called 102H had the best combination of characteristics. It is a Calcium Alumino-Sulfate grout that contains Ciment Fondu (calcium aluminate cement), Plaster of Paris (calcium sulfate hemihydrate), sand, Class F fly ash, boric acid and small quantities of additives. This composition afforded about ten hours of working time. Heat release began at 12 hours and was complete by 24 hours. The adiabatic temperature rise was 54 C which was within specification. The final product was hard and displayed no visible segregation. The density and maximum particle size were within specification.

Steimke, J.; Qureshi, Z.; Restivo, M.; Guerrero, H.

2011-01-28T23:59:59.000Z

336

Experimental studies of unbiased gluon jets from $e^{+}e^{-}$ annihilations using the jet boost algorithm  

E-Print Network [OSTI]

We present the first experimental results based on the jet boost algorithm, a technique to select unbiased samples of gluon jets in e+e- annihilations, i.e. gluon jets free of biases introduced by event selection or jet finding criteria. Our results are derived from hadronic Z0 decays observed with the OPAL detector at the LEP e+e- collider at CERN. First, we test the boost algorithm through studies with Herwig Monte Carlo events and find that it provides accurate measurements of the charged particle multiplicity distributions of unbiased gluon jets for jet energies larger than about 5 GeV, and of the jet particle energy spectra (fragmentation functions) for jet energies larger than about 14 GeV. Second, we apply the boost algorithm to our data to derive unbiased measurements of the gluon jet multiplicity distribution for energies between about 5 and 18 GeV, and of the gluon jet fragmentation function at 14 and 18 GeV. In conjunction with our earlier results at 40 GeV, we then test QCD calculations for the en...

Abbiendi, G; Åkesson, P F; Alexander, G; Allison, J; Amaral, P; Anagnostou, G; Anderson, K J; Arcelli, S; Asai, S; Axen, D A; Azuelos, Georges; Bailey, I; Barberio, E; Barillari, T; Barlow, R J; Batley, J Richard; Bechtle, P; Behnke, T; Bell, K W; Bell, P J; Bella, G; Bellerive, A; Benelli, G; Bethke, Siegfried; Biebel, O; Boeriu, O; Bock, P; Boutemeur, M; Braibant, S; Brigliadori, L; Brown, R M; Büsser, K; Burckhart, H J; Campana, S; Carnegie, R K; Caron, B; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Ciocca, C; Csilling, Akos; Cuffiani, M; Dado, S; de Roeck, A; De Wolf, E A; Desch, Klaus; Dienes, B; Donkers, M; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Etzion, E; Fabbri, Franco Luigi; Feld, L; Ferrari, P; Fiedler, F; Fleck, I; Ford, M; Frey, A; Fürtjes, A; Gagnon, P; Gary, J W; Gaycken, G; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Giunta, M; Goldberg, J; Gross, E; Grunhaus, Jacob; Gruwé, M; Günther, P O; Sen-Gupta, A; Hajdu, C; Hamann, M; Hanson, G G; Harel, A; Hauschild, M; Hawkes, C M; Hawkings, R; Hemingway, Richard J; Hensel, C; Herten, G; Heuer, R D; Hill, J C; Hoffman, K; Horváth, D; Igo-Kemenes, P; Ishii, K; Jeremie, H; Jovanovic, P; Junk, T R; Kanaya, N; Kanzaki, J; Karlen, Dean A; Kawagoe, K; Kawamoto, T; Keeler, Richard K; Kellogg, R G; Kennedy, B W; Klein, K; Klier, A; Kluth, S; Kobayashi, T; Kobel, M; Komamiya, S; Kormos, L L; Kramer, T; Krieger, P; Von Krogh, J; Krüger, K; Kühl, T; Kupper, M; Lafferty, G D; Landsman, Hagar Yaël; Lanske, D; Layter, J G; Lellouch, D; Letts, J; Levinson, L; Lillich, J; Lloyd, S L; Loebinger, F K; Lü, J; Ludwig, A; Ludwig, J; MacPherson, A; Mader, W; Marcellini, S; Martin, A J; Masetti, G; Mashimo, T; Mättig, P; McDonald, W J; McKenna, J A; McMahon, T J; McPherson, R A; Meijers, F; Menges, W; Merritt, F S; Mes, H; Michelini, Aldo; Mihara, S; Mikenberg, G; Miller, D J; Moed, S; Mohr, W; Mori, T; Mutter, A; Nagai, K; Nakamura, I; Nanjo, H; Neal, H A; Nisius, R; O'Neale, S W; Oh, A; Okpara, A N; Oreglia, M J; Orito, S; Pahl, C; Pásztor, G; Pater, J R; Pilcher, J E; Pinfold, J L; Plane, D E; Poli, B; Polok, J; Pooth, O; Przybycien, M B; Quadt, A; Rabbertz, K; Rembser, C; Renkel, P; Roney, J M; Rosati, S; Rozen, Y; Runge, K; Sachs, K; Saeki, T; Sarkisyan-Grinbaum, E; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schieck, J; Schörner-Sadenius, T; Schröder, M; Schumacher, M; Schwick, C; Scott, W G; Seuster, R; Shears, T G; Shen, B C; Sherwood, P; Skuja, A; Smith, A M; Sobie, R J; Söldner-Rembold, S; Spanó, F; Stahl, A; Stephens, K; Strom, D; Ströhmer, R; Tarem, S; Tasevsky, M; Teuscher, R; Thomson, M A; Torrence, E; Toya, D; Tran, P; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Ujvári, B; Vollmer, C F; Vannerem, P; Vertesi, R; Verzocchi, M; Voss, H; Vossebeld, Joost Herman; Waller, D; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wengler, T; Wermes, N; Wetterling, D; Wilson, G W; Wilson, J A; Wolf, G; Wyatt, T R; Yamashita, S; Zer-Zion, D; Zivkovic, L

2004-01-01T23:59:59.000Z

337

ORNL experiments to characterize fuel release from the reactor primary containment in severe LMFBR accidents  

SciTech Connect (OSTI)

This paper presents results from aerosol source term experiments performed in the ORNL Aerosol Release and Transport (ART) Program sponsored by the US NRC. The tests described were performed to provide information on fuel release from an LMFBR primary containment as a result of a hypothetical core-disruptive accident (HCDA). The release path investigated in these tests assumes that a fuel/sodium bubble is formed after disassembly that transports fuel and fission products through the sodium coolant and cover gas to be relased into the reactor secondary containment. Due to the excellent heat transfer characteristics of the sodium, there is potential for large attenuation of the maximum release.

Wright, A.L.; Kress, T.S.; Smith, A.M.

1980-01-01T23:59:59.000Z

338

Full-Volume, Three-Dimensional, Transient Measurements of Bubbly Flows Using Particle Tracking Velocimetry and Shadow Image Velocimetry Coupled with Pattern Recognition Techniques  

SciTech Connect (OSTI)

Develop a state-of-the-art non-intrusive diagnostic tool to perform simultaneous measurements of both the temporal and three-dimensional spatial velocity of the two phases of a bubbly flow. These measurements are required to provide a foundation for studying the constitutive closure relations needed in computational fluid dynamics and best-estimate thermal hydraulic codes employed in nuclear reactor safety analysis and severe accident simulation. Such kinds of full-field measurements are not achievable through the commonly used point-measurement techniques, such as hot wire, conductance probe, laser Doppler anemometry, etc. The results can also be used in several other applications, such as the dynamic transport of pollutants in water or studies of the dispersion of hazardous waste.

Yassin Hassan

2001-11-30T23:59:59.000Z

339

Dark jets in solar coronal holes  

E-Print Network [OSTI]

A new solar feature termed a dark jet is identified from observations of an extended solar coronal hole that was continuously monitored for over 44 hours by the EUV Imaging Spectrometer on board the Hinode spacecraft in 2011 February 8-10. Line-of-sight velocity maps derived from the coronal Fe XII $\\lambda$195.12 emission line, formed at 1.5 MK, revealed a number of large-scale, jet-like structures that showed significant blueshifts. The structures had either weak or no intensity signal in 193 A filter images from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory, suggesting that the jets are essentially invisible to imaging instruments. The dark jets are rooted in bright points and occur both within the coronal hole and at the quiet Sun-coronal hole boundary. They exhibit a wide range of shapes, from narrow columns to fan-shaped structures, and sometimes multiple jets are seen close together. A detailed study of one dark jet showed line-of-sight speeds increasing along the jet axis fr...

Young, Peter R

2015-01-01T23:59:59.000Z

340

Jet Reconstruction in Heavy Ion Collisions  

E-Print Network [OSTI]

Measurements of strong suppression of inclusive hadron distributions and di-hadron correlations at high $p_{T}$, while providing evidence for partonic energy loss, also suffer from geometric biases due to the competition of energy loss and fragmentation. The measurements of fully reconstructed jets is expected to lack these biases as the energy flow is measured independently of the fragmentation details. In this article, we review the recent results from the heavy ion collisions collected by the STAR experiment at RHIC on direct jet reconstruction utilizing the modern sequential recombination and cone jet reconstruction algorithms together with their background subtraction techniques. In order to assess the jet reconstruction biases a comparison with the jet cross section measurement in $\\sqrt{s}=200$ GeV p+p collisions scaled by the number of binary nucleon-nucleon collisions to account for nuclear geometric effects is performed. Comparison of the inclusive jet cross section obtained in central Au+Au events with that in $p+p$ collisions, published previously by STAR, suggests that unbiased jet reconstruction in the complex heavy ion environment indeed may be possible.

Sevil Salur

2009-05-12T23:59:59.000Z

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.


341

Composite Octet Searches with Jet Substructure  

SciTech Connect (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

342

Jet production in ep collisions Pierre Van Mechelen  

E-Print Network [OSTI]

Jet production in ep collisions Pierre Van Mechelen University of Antwerpen Pierre electroproduction #12; Jet production in ep collisions Pierre Van Mechelen HERA, H1 and ZEUS H1 ZEUS p (920 GeV) e ± (27.6 GeV) #12; Jet production in ep collisions Pierre Van Mechelen Jet finding algorithms Clustering

343

Methanation assembly using multiple reactors  

DOE Patents [OSTI]

A methanation assembly for use with a water supply and a gas supply containing gas to be methanated in which a reactor assembly has a plurality of methanation reactors each for methanating gas input to the assembly and a gas delivery and cooling assembly adapted to deliver gas from the gas supply to each of said methanation reactors and to combine water from the water supply with the output of each methanation reactor being conveyed to a next methanation reactor and carry the mixture to such next methanation reactor.

Jahnke, Fred C.; Parab, Sanjay C.

2007-07-24T23:59:59.000Z

344

Power Burst Facility (PBF) Reactor Reactor Decommissioning  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006PhotovoltaicSeptember 22,Reactor Decommissioning Click here to view

345

Geek-Up[6.24.11]: The End of Our Solar System is Bubbly  

Broader source: Energy.gov [DOE]

The Cray XT4 supercomputer at the Lawrence Berkeley National Laboratory’s National Energy Research Scientific Computing Center (NERSC) is helping to explain the froth of apparent "bubbles."

346

iBubble: Multi-keyword Routing Protocol for Heterogeneous Wireless Sensor Networks  

E-Print Network [OSTI]

, Matt Spear, Karl Levitt and S. Felix Wu Department of Computer Science UC Davis, Davis, CA 95616 Email. By utilizing keywords, iBubble bridges many routing and energy problems prevalent in WSN, and provides a simple

California at Davis, University of

347

EFFECTIVE EQUATIONS FOR SOUND AND VOID WAVE PROPAGATION IN BUBBLY FLUIDS  

E-Print Network [OSTI]

;1850 NIANQING WANG AND PETER SMEREKA calculation of the sound speed agrees with those of previous investigators including nonlinear effects. For review of the literature on acoustic waves in bubbly liquids the reader

Smereka, Peter

348

Bubble formation and Kr distribution in Kr-irradiated UO2  

SciTech Connect (OSTI)

In situ and ex situ transmission electron microscopy observation of small Kr bubbles in both single-crystal and polycrystalline UO2 were conducted to understand the inert gas bubble behavior in oxide nuclear fuel. The bubble size and volume swelling are shown as a weak function of ion dose but strongly depend on the temperature. The Kr bubble formation at room temperature was observed for the first time. The depth profiles of implanted Kr determined by atom probe tomography are in good agreement with the calculated profiles by SRIM, but the measured concentration of Kr is about 1/3 of calculated one. This difference is mainly due to low solubility of Kr in UO2 matrix, which has been confirmed by both density-functional theory calculations and chemical equilibrium analysis.

L.F. He; B. Valderrama; A.-R. Hassan; J. Yu; M. Gupta; J. Pakarinen; H.B. Henderson; J. Gan; M.A. Kirk; A.T. Nelson; M.V. Manuel; A. El-Azab; T.R. Allen

2015-01-01T23:59:59.000Z

349

Acoustic studies for alpha background rejection in dark matter bubble chamber detectors  

SciTech Connect (OSTI)

COUPP (Chicagoland Observatory for Underground Particle Physics) is an experiment with bubble chambers able to detect dark matter directly either with Spin-Dependent or with Spin-Independent interactions. The target material is a superheated liquid (usually CF3I) that can be bubble nucleated due to nuclear recoils produced by elastic collisions of dark matter particles. The bubble growth inside the chamber is accompanied with an acoustic signature. The acoustic technique has been successfully used to have a good alpha discrimination (about 99%). In this paper, we present different studies and results related with the characterization of the acoustic properties of the detector and the different phenomena involved in the acoustic measurements of the bubble growth, such as sound generation, sound transmission and optimization of piezoelectric transducers.

Bou-Cabo, M.; Felis, I.; Ardid, M.; Collaboration: COUPP Collaboration

2013-08-08T23:59:59.000Z

350

Correlation of black oil properties at pressures below the bubble-point  

E-Print Network [OSTI]

recourse in such cases is the use of empirically derived correlations This study considers the correlation of black oil Pressure-Volume-Temperature (PVT) properties for pressures at or below the bubble-point pressure. Specifically, we address the following...

Velarde, Jorge Javier

1996-01-01T23:59:59.000Z

351

Jet physics and the underlying event at the Tevatron  

SciTech Connect (OSTI)

Tevatron Run 2 results on the inclusive jet cross section (MidPoint and K{sub T} algorithm) and the b-jet and b{bar b}-jet cross section (MidPoint algorithm) are presented and compared with theory. The CDF b-jet {bar b}-jet {Delta}{phi} distribution is compared with theory and with the D0 jet No.1-jet No.2 {Delta}{phi} distribution. The understanding and modeling of the ''underlying event'' in Run 2 at the Tevatron is reviewed and new CDF results are presented.

Field, Rick; /Florida U.

2005-08-01T23:59:59.000Z

352

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

353

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

354

Squark and gluino production with jets  

SciTech Connect (OSTI)

We present cross section predictions for squark and gluino production at the LHC, in association with up to two additional hard jets. These cross sections can be very large in comparison to the inclusive Born rates. Because hadron collider experiments utilize hard jets in the reconstruction of cascade decays or as a way to separate squark and gluino production, the understanding of these processes is crucial. We show to what degree hard jet radiation can be described by shower algorithms and point out how tuning these showers, for example to top quark pair production, could help reduce theoretical uncertainties for new physics searches at the LHC.

Plehn, T.; /Munich, Max Planck Inst.; Rainwater, D.; /Rochester U.; Skands, P.; /Fermilab

2005-10-01T23:59:59.000Z

355

A TEN MEGAWATT BOILING HETEROGENEOUS PACKAGE POWER REACTOR. Reactor...  

Office of Scientific and Technical Information (OSTI)

A reactor and associated power plant designed to produce 1.05 Mwh and 3.535 Mwh of steam for heating purposes are described. The total thermal output of the reactor is 10 Mwh....

356

Hypersonic Buckshot: Astrophysical Jets as Heterogeneous Collimated Plasmoids  

E-Print Network [OSTI]

Herbig-Haro (HH) jets are commonly thought of as homogeneous beams of plasma traveling at hypersonic velocities. Structure within jet beams is often attributed to periodic or ``pulsed'' variations of conditions at the jet source. Simulations based on this scenario result in knots extending across the jet diameter. Observations and recent high energy density laboratory experiments shed new light on structures below this scale and indicate they may be important for understanding the fundamentals of jet dynamics. In this paper we offer an alternative to ``pulsed'' models of protostellar jets. Using direct numerical simulations we explore the possibility that jets are chains of sub-radial clumps propagating through a moving inter-clump medium. Our models explore an idealization of this scenario by injecting small ($r\\rho_{jet}$) spheres embedded in an otherwise smooth inter-clump jet flow. The spheres are initialized with velocities differing from the jet velocity by $\\sim15$%. We find the consequences of shiftin...

Yirak, Kristopher; Cunningham, Andrew J; Mitran, Sorin

2008-01-01T23:59:59.000Z

357

Heat dissipating nuclear reactor  

DOE Patents [OSTI]

Disclosed is a nuclear reactor containment adapted to retain and cool core debris in the unlikely event of a core meltdown and subsequent breach in the reactor vessel. The reactor vessel is seated in a cavity which has a thick metal sidewall that is integral with a thick metal basemat at the bottom of the cavity. The basemat extends beyond the perimeter of the cavity sidewall. Underneath the basemat is a porous bed with water pipes and steam pipes running into it. Water is introduced into the bed and converted into steam which is vented to the atmosphere. A plurality of metal pilings in the form of H-beams extends from the metal base plate downwardly and outwardly into the earth.

Hunsbedt, Anstein (Los Gatos, CA); Lazarus, Jonathan D. (Sunnyvale, CA)

1987-01-01T23:59:59.000Z

358

Inexpensive Mini Thermonuclear Reactor  

E-Print Network [OSTI]

This proposed design for a mini thermonuclear reactor uses a method based upon a series of important innovations. A cumulative explosion presses a capsule with nuclear fuel up to 100 thousands of atmospheres, the explosive electric generator heats the capsule/pellet up to 100 million degrees and a special capsule and a special cover which keeps these pressure and temperature in capsule up to 0.001 sec. which is sufficient for Lawson criteria for ignition of thermonuclear fuel. Major advantages of these reactors/bombs is its very low cost, dimension, weight and easy production, which does not require a complex industry. The mini thermonuclear bomb can be delivered as a shell by conventional gun (from 155 mm), small civil aircraft, boat or even by an individual. The same method may be used for thermonuclear engine for electric energy plants, ships, aircrafts, tracks and rockets. Key words: Thermonuclear mini bomb, thermonuclear reactor, nuclear energy, nuclear engine,

Alexander Bolonkin; Alexander Bolonkin

359

Nuclear reactor safety device  

DOE Patents [OSTI]

A safety device is disclosed for use in a nuclear reactor for axially repositioning a control rod with respect to the reactor core in the event of an upward thermal excursion. Such safety device comprises a laminated helical ribbon configured as a tube-like helical coil having contiguous helical turns with slidably abutting edges. The helical coil is disclosed as a portion of a drive member connected axially to the control rod. The laminated ribbon is formed of outer and inner laminae. The material of the outer lamina has a greater thermal coefficient of expansion than the material of the inner lamina. In the event of an upward thermal excursion, the laminated helical coil curls inwardly to a smaller diameter. Such inward curling causes the total length of the helical coil to increase by a substantial increment, so that the control rod is axially repositioned by a corresponding amount to reduce the power output of the reactor.

Hutter, Ernest (Wilmette, IL)

1986-01-01T23:59:59.000Z

360

Fusion reactor control  

SciTech Connect (OSTI)

The plasma kinetic temperature and density changes, each per an injected fuel density rate increment, control the energy supplied by a thermonuclear fusion reactor in a power production cycle. This could include simultaneously coupled control objectives for plasma current, horizontal and vertical position, shape and burn control. The minimum number of measurements required, use of indirect (not plasma parameters) system measurements, and distributed control procedures for burn control are to be verifiable in a time dependent systems code. The International Thermonuclear Experimental Reactor (ITER) has the need to feedback control both the fusion output power and the driven plasma current, while avoiding damage to diverter plates. The system engineering of fusion reactors must be performed to assure their development expeditiously and effectively by considering reliability, availability, maintainability, environmental impact, health and safety, and cost.

Plummer, D.A.

1995-12-31T23:59:59.000Z

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

Thermionic Reactor Design Studies  

SciTech Connect (OSTI)

Paper presented at the 29th IECEC in Monterey, CA in August 1994. The present paper describes some of the author's conceptual designs and their rationale, and the special analytical techniques developed to analyze their (thermionic reactor) performance. The basic designs, first published in 1963, are based on single-cell converters, either double-ended diodes extending over the full height of the reactor core or single-ended diodes extending over half the core height. In that respect they are similar to the thermionic fuel elements employed in the Topaz-2 reactor subsequently developed in the Soviet Union, copies of which were recently imported by the U.S. As in the Topaz-2 case, electrically heated steady-state performance tests of the converters are possible before fueling.

Schock, Alfred

1994-08-01T23:59:59.000Z

362

Reactor for exothermic reactions  

DOE Patents [OSTI]

A liquid phase process for oligomerization of C.sub.4 and C.sub.5 isoolefins or the etherification thereof with C.sub.1 to C.sub.6 alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120.degree. to 300.degree. F. Wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled.

Smith, Jr., Lawrence A. (Bellaire, TX); Hearn, Dennis (Houston, TX); Jones, Jr., Edward M. (Friendswood, TX)

1993-01-01T23:59:59.000Z

363

Heat dissipating nuclear reactor  

DOE Patents [OSTI]

Disclosed is a nuclear reactor containment adapted to retain and cool core debris in the unlikely event of a core meltdown and subsequent breach in the reactor vessel. The reactor vessel is seated in a cavity which has a thick metal sidewall that is integral with a thick metal basemat at the bottom of the cavity. The basemat extends beyond the perimeter of the cavity sidewall. Underneath the basemat is a porous bed with water pipes and steam pipes running into it. Water is introduced into the bed and converted into steam which is vented to the atmosphere. A plurality of metal pilings in the form of H-beams extend from the metal base plate downwardly and outwardly into the earth.

Hunsbedt, A.; Lazarus, J.D.

1985-11-21T23:59:59.000Z

364

Reactor for exothermic reactions  

DOE Patents [OSTI]

A liquid phase process is described for oligomerization of C[sub 4] and C[sub 5] isoolefins or the etherification thereof with C[sub 1] to C[sub 6] alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300 F. Wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled.

Smith, L.A. Jr.; Hearn, D.; Jones, E.M. Jr.

1993-03-02T23:59:59.000Z

365

Figure 2: The mercury jet target geometry. The proton beam and mercury jet cross at z=-37.5 cm.  

E-Print Network [OSTI]

Figure 2: The mercury jet target geometry. The proton beam and mercury jet cross at z=-37.5 cm. Figure 3: The layout of multiple proton beam entry directions relative to mercury jet at z=-75 cm. A PION of a free liquid mercury jet with an intense proton beam. We study the variation of meson production

McDonald, Kirk

366

Effect of bubble volume fraction on the shear and extensional rheology of bubbly liquids based on guar gum (a Giesekus fluid) as continuous phase  

E-Print Network [OSTI]

al., 2012). Bubbly liquids are also 57 encountered in nature in the form of magmas (Manga and Loewenberg, 2001; Gonnermann and 58 Manga, 2007) and in other industrial sectors in the form of foamed cement (Ahmed et al., 2009), 59 extracted crude oil... , retarding coalescence and creaming. In 52 the food sector, the bubble phase is usually air and aerated liquid foods are ubiquitous, from 53 beverages to baked products, ice creams, dairy systems and confectionery, e.g. van Aken (2001). 54 Aeration yields...

Torres, M. D.; Hallmark, B.; Wilson, D. I.

2014-09-16T23:59:59.000Z

367

Repair welding of fusion reactor components. Final technical report  

SciTech Connect (OSTI)

The exposure of metallic materials, such as structural components of the first wall and blanket of a fusion reactor, to neutron irradiation will induce changes in both the material composition and microstructure. Along with these changes can come a corresponding deterioration in mechanical properties resulting in premature failure. It is, therefore, essential to expect that the repair and replacement of the degraded components will be necessary. Such repairs may require the joining of irradiated materials through the use of fusion welding processes. The present ITER (International Thermonuclear Experimental Reactor) conceptual design is anticipated to have about 5 km of longitudinal welds and ten thousand pipe butt welds in the blanket structure. A recent study by Buende et al. predict that a failure is most likely to occur in a weld. The study is based on data from other large structures, particularly nuclear reactors. The data used also appear to be consistent with the operating experience of the Fast Flux Test Facility (FFTF). This reactor has a fuel pin area comparable with the area of the ITER first wall and has experienced one unanticipated fuel pin failure after two years of operation. The repair of irradiated structures using fusion welding will be difficult due to the entrapped helium. Due to its extremely low solubility in metals, helium will diffuse and agglomerate to form helium bubbles after being trapped at point defects, dislocations, and grain boundaries. Welding of neutron-irradiated type 304 stainless steels has been reported with varying degree of heat-affected zone cracking (HAZ). The objectives of this study were to determine the threshold helium concentrations required to cause HAZ cracking and to investigate techniques that might be used to eliminate the HAZ cracking in welding of helium-containing materials.

Chin, B.A.; Wang, C.A.

1997-09-30T23:59:59.000Z

368

Fusion reactor pumped laser  

DOE Patents [OSTI]

A nuclear pumped laser capable of producing long pulses of very high power laser radiation is provided. A toroidal fusion reactor provides energetic neutrons which are slowed down by a moderator. The moderated neutrons are converted to energetic particles capable of pumping a lasing medium. The lasing medium is housed in an annular cell surrounding the reactor. The cell includes an annular reflecting mirror at the bottom and an annular output window at the top. A neutron reflector is disposed around the cell to reflect escaping neutrons back into the cell. The laser radiation from the annular window is focused onto a beam compactor which generates a single coherent output laser beam.

Jassby, Daniel L. (Princeton, NJ)

1988-01-01T23:59:59.000Z

369

Fast quench reactor method  

DOE Patents [OSTI]

A fast quench reaction includes a reactor chamber having a high temperature heating means such as a plasma torch at its inlet and a means of rapidly expanding a reactant stream, such as a restrictive convergent-divergent nozzle at its outlet end. Metal halide reactants are injected into the reactor chamber. Reducing gas is added at different stages in the process to form a desired end product and prevent back reactions. The resulting heated gaseous stream is then rapidly cooled by expansion of the gaseous stream.

Detering, Brent A. (Idaho Falls, ID); Donaldson, Alan D. (Idaho Falls, ID); Fincke, James R. (Idaho Falls, ID); Kong, Peter C. (Idaho Falls, ID); Berry, Ray A. (Idaho Falls, ID)

1999-01-01T23:59:59.000Z

370

Fast quench reactor method  

DOE Patents [OSTI]

A fast quench reaction includes a reactor chamber having a high temperature heating means such as a plasma torch at its inlet and a means of rapidly expanding a reactant stream, such as a restrictive convergent-divergent nozzle at its outlet end. Metal halide reactants are injected into the reactor chamber. Reducing gas is added at different stages in the process to form a desired end product and prevent back reactions. The resulting heated gaseous stream is then rapidly cooled by expansion of the gaseous stream. 8 figs.

Detering, B.A.; Donaldson, A.D.; Fincke, J.R.; Kong, P.C.; Berry, R.A.

1999-08-10T23:59:59.000Z

371

Diagnostics for hybrid reactors  

SciTech Connect (OSTI)

The Hybrid Reactor(HR) can be considered an attractive actinide-burner or a fusion assisted transmutation for destruction of transuranic(TRU) nuclear waste. The hybrid reactor has two important subsystems: the tokamak neutron source and the blanket which includes a fuel zone where the TRU are placed and a tritium breeding zone. The diagnostic system for a HR must be as simple and robust as possible to monitor and control the plasma scenario, guarantee the protection of the machine and monitor the transmutation.

Orsitto, Francesco Paolo [ENEA Unita' Tecnica Fusione , Associazione ENEA-EURATOM sulla Fusione C R Frascati v E Fermi 45 00044 Frascati (Italy)

2012-06-19T23:59:59.000Z

372

Perspectives on reactor safety  

SciTech Connect (OSTI)

The US Nuclear Regulatory Commission (NRC) maintains a technical training center at Chattanooga, Tennessee to provide appropriate training to both new and experienced NRC employees. This document describes a one-week course in reactor, safety concepts. The course consists of five modules: (1) historical perspective; (2) accident sequences; (3) accident progression in the reactor vessel; (4) containment characteristics and design bases; and (5) source terms and offsite consequences. The course text is accompanied by slides and videos during the actual presentation of the course.

Haskin, F.E. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Chemical and Nuclear Engineering; Camp, A.L. [Sandia National Labs., Albuquerque, NM (United States)

1994-03-01T23:59:59.000Z

373

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

374

Di-jet hadron pair correlation in a hydrodynamical model with a quenching jet  

E-Print Network [OSTI]

In jet quenching, a hard QCD parton, before fragmenting into a jet of hadrons, deposits a fraction of its energy in the medium, leading to suppressed production of high-$p_T$ hadrons. Assuming that the deposited energy quickly thermalizes, we simulate the subsequent hydrodynamic evolution of the QGP fluid. Hydrodynamic evolution and subsequent particle emission depend on the jet trajectories. Azimuthal distribution of excess $\\pi^-$ due to quenching jet, averaged over all the trajectories, reasonably well reproduce the di-hadron correlation as measured by the STAR and PHENIX collaboration in central and in peripheral Au+Au collisions.

A. K. Chaudhuri

2008-01-15T23:59:59.000Z

375

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

SciTech Connect (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

376

Innovative design of uranium startup fast reactors  

E-Print Network [OSTI]

Sodium Fast Reactors are one of the three candidates of GEN-IV fast reactors. Fast reactors play an important role in saving uranium resources and reducing nuclear wastes. Conventional fast reactors rely on transuranic ...

Fei, Tingzhou

2012-01-01T23:59:59.000Z

377

Reactor operation environmental information document  

SciTech Connect (OSTI)

The Savannah River Site (SRS) produces nuclear materials, primarily plutonium and tritium, to meet the requirements of the Department of Defense. These products have been formed in nuclear reactors that were built during 1950--1955 at the SRS. K, L, and P reactors are three of five reactors that have been used in the past to produce the nuclear materials. All three of these reactors discontinued operation in 1988. Currently, intense efforts are being extended to prepare these three reactors for restart in a manner that protects human health and the environment. To document that restarting the reactors will have minimal impacts to human health and the environment, a three-volume Reactor Operations Environmental Impact Document has been prepared. The document focuses on the impacts of restarting the K, L, and P reactors on both the SRS and surrounding areas. This volume discusses the geology, seismology, and subsurface hydrology. 195 refs., 101 figs., 16 tabs.

Haselow, J.S.; Price, V.; Stephenson, D.E.; Bledsoe, H.W.; Looney, B.B.

1989-12-01T23:59:59.000Z

378

Feasibility Study for a New Business Jet  

E-Print Network [OSTI]

This report demonstrates details of a feasibility study of a new business jet as an effort to complete the requirements for a field project (EMGT 835) in Engineering Management. The study is conducted during global economic crisis to identify a...

Mousa, Yasser Abdullah

2009-05-15T23:59:59.000Z

379

Inclusive jet cross section at CDF  

SciTech Connect (OSTI)

This contribution reports on preliminary measurements of the inclusive jet production cross section in p{bar p} collisions at {radical}s = 1.96 TeV using data collected with CDF corresponding to an integrated luminosity of 385 pb{sup -1}. Two analyzes are presented: one uses the longitudinally invariant k{sub T} algorithm to reconstruct the jets, the other uses the midpoint algorithm. Both are limited to jets with rapidity in the range 0.1 < |y{sup jet}| < 0.7. The measured cross sections are in good agreement with next-to-leading order perturbative QCD predictions after including the non-perturbative corrections necessary to account for underlying event and hadronization effects.

Lefevre, R.; Martinez, M.; /Barcelona, IFAE

2005-01-01T23:59:59.000Z

380

Reactor operation safety information document  

SciTech Connect (OSTI)

The report contains a reactor facility description which includes K, P, and L reactor sites, structures, operating systems, engineered safety systems, support systems, and process and effluent monitoring systems; an accident analysis section which includes cooling system anomalies, radioactive materials releases, and anticipated transients without scram; a summary of onsite doses from design basis accidents; severe accident analysis (reactor core disruption); a description of operating contractor organization and emergency planning; and a summary of reactor safety evolution. (MB)

Not Available

1990-01-01T23:59:59.000Z

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.


381

Reed Reactor Facility Annual Report  

SciTech Connect (OSTI)

This is the report of the operations, experiments, modifications, and other aspects of the Reed Reactor Facility for the year.

Frantz, Stephen G.

2000-09-01T23:59:59.000Z

382

Measuring collinear W emissions inside jets  

E-Print Network [OSTI]

Single and multiple emission of electroweak gauge bosons and in particular of W bosons is discussed in the parton shower language. Algorithms and observables for the reconstruction of both leptonically and hadronically decaying W bosons inside light quark jets are compared, and they are applied to a study of how emission rates of W bosons in light-jet events at the LHC could be measured.

Frank Krauss; Petar Petrov; Marek Schoenherr; Michael Spannowsky

2014-03-19T23:59:59.000Z

383

New results on jet fragmentation at CDF  

SciTech Connect (OSTI)

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

384

Thermal Reactor Safety  

SciTech Connect (OSTI)

Information is presented concerning fire risk and protection; transient thermal-hydraulic analysis and experiments; class 9 accidents and containment; diagnostics and in-service inspection; risk and cost comparison of alternative electric energy sources; fuel behavior and experiments on core cooling in LOCAs; reactor event reporting analysis; equipment qualification; post facts analysis of the TMI-2 accident; and computational methods.

Not Available

1980-06-01T23:59:59.000Z

385

Nuclear reactor building  

DOE Patents [OSTI]

A reactor building for enclosing a nuclear reactor includes a containment vessel having a wetwell disposed therein. The wetwell includes inner and outer walls, a floor, and a roof defining a wetwell pool and a suppression chamber disposed thereabove. The wetwell and containment vessel define a drywell surrounding the reactor. A plurality of vents are disposed in the wetwell pool in flow communication with the drywell for channeling into the wetwell pool steam released in the drywell from the reactor during a LOCA for example, for condensing the steam. A shell is disposed inside the wetwell and extends into the wetwell pool to define a dry gap devoid of wetwell water and disposed in flow communication with the suppression chamber. In a preferred embodiment, the wetwell roof is in the form of a slab disposed on spaced apart support beams which define therebetween an auxiliary chamber. The dry gap, and additionally the auxiliary chamber, provide increased volume to the suppression chamber for improving pressure margin.

Gou, Perng-Fei (Saratoga, CA); Townsend, Harold E. (Campbell, CA); Barbanti, Giancarlo (Sirtori, IT)

1994-01-01T23:59:59.000Z

386

Nuclear reactor building  

DOE Patents [OSTI]

A reactor building for enclosing a nuclear reactor includes a containment vessel having a wetwell disposed therein. The wetwell includes inner and outer walls, a floor, and a roof defining a wetwell pool and a suppression chamber disposed there above. The wetwell and containment vessel define a drywell surrounding the reactor. A plurality of vents are disposed in the wetwell pool in flow communication with the drywell for channeling into the wetwell pool steam released in the drywell from the reactor during a LOCA for example, for condensing the steam. A shell is disposed inside the wetwell and extends into the wetwell pool to define a dry gap devoid of wetwell water and disposed in flow communication with the suppression chamber. In a preferred embodiment, the wetwell roof is in the form of a slab disposed on spaced apart support beams which define there between an auxiliary chamber. The dry gap, and additionally the auxiliary chamber, provide increased volume to the suppression chamber for improving pressure margin. 4 figures.

Gou, P.F.; Townsend, H.E.; Barbanti, G.

1994-04-05T23:59:59.000Z

387

NETL - Chemical Looping Reactor  

ScienceCinema (OSTI)

NETL's Chemical Looping Reactor unit is a high-temperature integrated CLC process with extensive instrumentation to improve computational simulations. A non-reacting test unit is also used to study solids flow at ambient temperature. The CLR unit circulates approximately 1,000 pounds per hour at temperatures around 1,800 degrees Fahrenheit.

None

2014-06-26T23:59:59.000Z

388

Nuclear Reactors and Technology  

SciTech Connect (OSTI)

This publication Nuclear Reactors and Technology (NRT) announces on a monthly basis the current worldwide information available from the open literature on nuclear reactors and technology, including all aspects of power reactors, components and accessories, fuel elements, control systems, and materials. This publication contains the abstracts of DOE reports, journal articles, conference papers, patents, theses, and monographs added to the Energy Science and Technology Database during the past month. Also included are US information obtained through acquisition programs or interagency agreements and international information obtained through the International Energy Agency`s Energy Technology Data Exchange or government-to-government agreements. The digests in NRT and other citations to information on nuclear reactors back to 1948 are available for online searching and retrieval on the Energy Science and Technology Database and Nuclear Science Abstracts (NSA) database. Current information, added daily to the Energy Science and Technology Database, is available to DOE and its contractors through the DOE Integrated Technical Information System. Customized profiles can be developed to provide current information to meet each user`s needs.

Cason, D.L.; Hicks, S.C. [eds.

1992-01-01T23:59:59.000Z

389

Fossil fuel furnace reactor  

DOE Patents [OSTI]

A fossil fuel furnace reactor is provided for simulating a continuous processing plant with a batch reactor. An internal reaction vessel contains a batch of shale oil, with the vessel having a relatively thin wall thickness for a heat transfer rate effective to simulate a process temperature history in the selected continuous processing plant. A heater jacket is disposed about the reactor vessel and defines a number of independent controllable temperature zones axially spaced along the reaction vessel. Each temperature zone can be energized to simulate a time-temperature history of process material through the continuous plant. A pressure vessel contains both the heater jacket and the reaction vessel at an operating pressure functionally selected to simulate the continuous processing plant. The process yield from the oil shale may be used as feedback information to software simulating operation of the continuous plant to provide operating parameters, i.e., temperature profiles, ambient atmosphere, operating pressure, material feed rates, etc., for simulation in the batch reactor.

Parkinson, William J. (Los Alamos, NM)

1987-01-01T23:59:59.000Z

390

The Infrared Jet in 3C31  

E-Print Network [OSTI]

We report the detection of infrared emission from the jet of the nearby FR I radio galaxy 3C 31. The jet was detected with the IRAC instrument on Spitzer at 4.5 micron, 5.8 micron, and 8.0 micron out to 30" (13 kpc) from the nucleus. We measure radio, infrared, optical, and X-ray fluxes in three regions along the jet determined by the infrared and X-ray morphology. Radio through X-ray spectra in these regions demonstrate that the emission can be interpreted as synchrotron emission from a broken power-law distribution of electron energies. We find significant differences in the high energy spectra with increasing distance from the nucleus. Specifically, the high energy slope increases from 0.86 to 1.72 from 1 kpc to 12 kpc along the jet, and the spectral break likewise increases in frequency along the jet from 10-100's of GHz to ~20 THz. Thus the ratio of IR to X-ray flux in the jet increases by at least an order of magnitude with increasing distance from the nucleus. We argue that these changes cannot simply ...

Lanz, Lauranne; Kraft, Ralph P; Birkinshaw, Mark; Lal, Dharam V; Forman, William R; Jones, Christine; Worrall, Diana M

2015-01-01T23:59:59.000Z

391

Comparison of the bubble size distribution in silicate foams using 2-dimensional images and 3-dimensional x-ray microtomography  

SciTech Connect (OSTI)

Three silicate glasses were hydrated at high pressure and then heated at atmospheric pressure to exsolve the water into bubbles and create foams. The bubble size distribution in these foams was measured by x-ray microtomography on the GSECARS BM-13 beamline at the Advanced Photon Source. The bubble area distributions were measured in two dimensions using the image slices produced from the microtomography and the software ImageJ. The bubble volume distributions were measured from the three-dimensional tomographic images with the BLOB3D software. We found that careful analysis of the microtomography data in both two and three dimensions was necessary to avoid the physically unrealistic, experimental artifact of identifying and counting many small bubbles whose surfaces were not defined by a septum of glass. When this artifact was avoided the foams demonstrated power-law distributions of bubble sizes in both two and three dimensions. Conversion of the power-law exponents for bubble areas measured in two dimensions to exponents for bubble volumes usually agreed with the measured three dimensional volume exponents. Furthermore, the power-law distributions for bubble volumes typically agree with multiple theories of bubble growth, all of which yield an exponent of 1 for the cumulative bubble volume distribution. The measured bubble volume distributions with exponents near 0.3 can be explained by diffusive growth as proposed by other authors, but distributions with exponents near 1.4 remain to be explained and are the subject of continuing research on the effects of water concentration and melt viscosity on foaming behavior.

Robert, G.; Baker, D.R.; Rivers, M.L.; Allard, E.; Larocque, J. (McGill); (UC)

2005-02-03T23:59:59.000Z

392

Sound Waves from Quenched Jets  

E-Print Network [OSTI]

Heavy ion collisions at RHIC/LHC energies are well described by the (nearly ideal) hydrodynamics. Last year this success has been extended to higher angular harmonics, $v_n,n=3..9$ induced by initial-state perturbations, in analogy to cosmic microwave background fluctuations. Here we use hydrodynamics to study sound propagation emitted by quenched jets. We use the so called "geometric acoustics" to follow the sound propagation, on top of the expanding fireball. The conical waves, known as "Mach cones", turn out to be strongly distorted. We show that large radial flow makes the observed particle spectra to be determined mostlly by the vicinity of their intersection with the fireball's space-like and time-like freezeout surfaces. We further show how the waves modify the freezeout surfaces and spectra. We end up comparing our calculations to the two-particle correlation functions at RHIC, while emphasizing that studies of dijet events observed at LHC should provide much better test of our theory.

Vladimir Khachatryan; Edward Shuryak

2011-08-15T23:59:59.000Z

393

PHOTOSPHERIC EMISSION FROM STRATIFIED JETS  

SciTech Connect (OSTI)

We explore photospheric emissions from stratified two-component jets, wherein a highly relativistic spine outflow is surrounded by a wider and less relativistic sheath outflow. Thermal photons are injected in regions of high optical depth and propagated until the photons escape at the photosphere. Because of the presence of shear in velocity (Lorentz factor) at the boundary of the spine and sheath region, a fraction of the injected photons are accelerated using a Fermi-like acceleration mechanism such that a high-energy power-law tail is formed in the resultant spectrum. We show, in particular, that if a velocity shear with a considerable variance in the bulk Lorentz factor is present, the high-energy part of observed gamma-ray bursts (GRBs) photon spectrum can be explained by this photon acceleration mechanism. We also show that the accelerated photons might also account for the origin of the extra-hard power-law component above the bump of the thermal-like peak seen in some peculiar bursts (e.g., GRB 090510, 090902B, 090926A). We demonstrate that time-integrated spectra can also reproduce the low-energy spectrum of GRBs consistently using a multi-temperature effect when time evolution of the outflow is considered. Last, we show that the empirical E{sub p}-L{sub p} relation can be explained by differences in the outflow properties of individual sources.

Ito, Hirotaka; Nagataki, Shigehiro; Ono, Masaomi; Lee, Shiu-Hang; Mao, Jirong [Astrophysical Big Bang Laboratory, RIKEN, Saitama 351-0198 (Japan); Yamada, Shoichi [Department of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Pe'er, Asaf [Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Mizuta, Akira [KEK Theory Center, Tsukuba 305-0801 (Japan); Harikae, Seiji, E-mail: hito@yukawa.kyoto-u.ac.jp [Quants Research Department, Financial Engineering Division, Mitsubishi UFJ Morgan Stanley Securities Co., Ltd., Mejirodai Bldg., 3-29-20 Mejirodai, Bunkyo-ku, Tokyo 112-8688 (Japan)

2013-11-01T23:59:59.000Z

394

Reactor vessel support system. [LMFBR  

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, M.P.; Holley, J.C.

1980-05-09T23:59:59.000Z

395

Particle multiplicity of unbiased gluon jets from $e^+ e^-$ three-jet events  

E-Print Network [OSTI]

The charged particle multiplicities of two- and three-jet events from the reaction e+e- -> Z0 -> hadrons are measured for Z0 decays to light quark (uds) flavors. Using recent theoretical expressions to account for biases from event selection, results corresponding to unbiased gluon jets are extracted over a range of jet energies from about 11 to 30 GeV. We find consistency between these results and direct measurements of unbiased gluon jet multiplicity from upsilon and Z0 decays. The unbiased gluon jet data including the direct measurements are compared to corresponding results for quark jets. We perform fits based on analytic expressions for particle multiplicity in jets to determine the ratio r = Ng/Nq of multiplicities between gluon and quark jets as a function of energy. We also determine the ratio of slopes, r(1) = (dNg/dy)/(dNq/dy), and of curvatures, r(2) = (d2Ng/dy2)/(d2Nq/dy2), where y specifies the energy scale. At 30 GeV, we find r = 1.422 +/- 0.051, r(1) = 1.761 +/- 0.071 and r(2) = 1.98 +/- 0.13,...

Abbiendi, G; Åkesson, P F; Alexander, Gideon; Allison, J; Anagnostou, G; Anderson, K J; Arcelli, S; Asai, S; Axen, D A; Azuelos, Georges; Bailey, I; Barberio, E; Barlow, R J; Batley, J Richard; Bechtle, P; Behnke, T; Bell, K W; Bell, P J; Bella, G; Bellerive, A; Benelli, G; Bethke, Siegfried; Biebel, O; Bloodworth, Ian J; Boeriu, O; Bock, P; Böhme, J; Bonacorsi, D; Boutemeur, M; Braibant, S; Brigliadori, L; Brown, R M; Burckhart, H J; Cammin, J; Campana, S; Carnegie, R K; Caron, B; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Clarke, P E L; Clay, E; Cohen, I; Couchman, J; Csilling, Akos; Cuffiani, M; Dado, S; Dallavalle, G M; Dallison, S; de Roeck, A; De Wolf, E A; Dervan, P J; Desch, Klaus; Dienes, B; Donkers, M; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Etzion, E; Fabbri, Franco Luigi; Feld, L; Ferrari, P; Fiedler, F; Fleck, I; Ford, M; Frey, A; Fürtjes, A; Futyan, D I; Gagnon, P; Gary, J W; Gaycken, G; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Giunta, M; Goldberg, J; Graham, K; Gross, E; Grunhaus, Jacob; Gruwé, M; Günther, P O; Sen-Gupta, A; Hajdu, C; Hamann, M; Hanson, G G; Harder, K; Harel, A; Harin-Dirac, M; Hauschild, M; Hauschildt, J; Hawkes, C M; Hawkings, R; Hemingway, Richard J; Hensel, C; Herten, G; Heuer, R D; Hill, J C; Hoffman, K; Homer, R James; Horváth, D; Hossain, K R; Howard, R; Hüntemeyer, P; Igo-Kemenes, P; Ishii, K; Jawahery, A; Jeremie, H; Jones, C R; Jovanovic, P; Junk, T R; Kanaya, N; Kanzaki, J; Karapetian, G V; Karlen, D A; Kartvelishvili, V G; Kawagoe, K; Kawamoto, T; Keeler, Richard K; Kellogg, R G; Kennedy, B W; Kim, D H; Klein, K; Klier, A; Kluth, S; Kobayashi, T; Kobel, M; Kokott, T P; Komamiya, S; Kowalewski, R V; Kramer, T; Kress, T; Krieger, P; Von Krogh, J; Krop, D; Kühl, T; Kupper, M; Kyberd, P; Lafferty, G D; Landsman, Hagar Yaël; Lanske, D; Lawson, I; Layter, J G; Leins, A; Lellouch, Daniel; Letts, J; Levinson, L; Lillich, J; Littlewood, C; Lloyd, S L; Loebinger, F K; Lü, J; Ludwig, J; Macchiolo, A; MacPherson, A L; Mader, W; Marcellini, S; Marchant, T E; Martin, A J; Martin, J P; Martínez, G; Masetti, G; Mashimo, T; Mättig, P; McDonald, W J; McKenna, J A; McMahon, T J; McPherson, R A; Meijers, F; Méndez-Lorenzo, P; Menges, W; Merritt, F S; Mes, H; Michelini, Aldo; Mihara, S; Mikenberg, G; Miller, D J; Moed, S; Mohr, W; Mori, T; Mutter, A; Nagai, K; Nakamura, I; Neal, H A; Nisius, R; O'Neale, S W; Oh, A; Okpara, A N; Oreglia, M J; Orito, S; Pahl, C; Pásztor, G; Pater, J R; Patrick, G N; Pilcher, J E; Pinfold, James L; Plane, D E; Poli, B; Polok, J; Pooth, O; Quadt, A; Rabbertz, K; Rembser, C; Renkel, P; Rick, Hartmut; Rodning, N L; Roney, J M; Rosati, S; Roscoe, K; Rozen, Y; Runge, K; Rust, D R; Sachs, K; Saeki, T; Sahr, O; Sarkisyan-Grinbaum, E; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schröder, M; Schumacher, M; Schwick, C; Scott, W G; Seuster, R; Shears, T G; Shen, B C; Shepherd-Themistocleous, C H; Sherwood, P; Skuja, A; Smith, A M; Snow, G A; Sobie, Randall J; Söldner-Rembold, S; Spagnolo, S; Spanó, F; Sproston, M; Stahl, A; Stephens, K; Strom, D; Ströhmer, R; Stumpf, L; Surrow, B; Tarem, S; Tasevsky, M; Taylor, R J; Teuscher, R; Thomas, J; Thomson, M A; Torrence, E; Toya, D; Trefzger, T M; Tricoli, A; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Ujvári, B; Vachon, B; Vollmer, C F; Vannerem, P; Verzocchi, M; Voss, H; Vossebeld, Joost Herman; Waller, D; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wengler, T; Wermes, N; Wetterling, D; Wilson, G W; Wilson, J A; Wyatt, T R; Yamashita, S; Zacek, V; Zer-Zion, D; 10.1007/s100520200926

2002-01-01T23:59:59.000Z

396

Jet vetoes versus giant K-factors in the exclusive Z+1-jet cross section  

E-Print Network [OSTI]

The ATLAS measurement of the exclusive $Z$+1-jet cross section shows a surprising agreement with fixed-order predictions in the kinematic region expected to be dominated by large jet-veto logarithms. We identify the explanation for this effect: the jet-isolation criterion implemented by ATLAS allows dijet events where an energetic jet is collinear to a final-state lepton. This process contains a giant K-factor arising from the collinear emission of a Z-boson from the dijet configuration which overwhelms the effect of the jet-veto logarithms. We provide numerical results for 7 TeV, 8 TeV and 14 TeV LHC collisions that demonstrate the interplay between the jet-veto logarithms and the giant K-factor in the theoretical prediction. We suggest an alternate isolation criterion that removes the giant K-factor and allows for a direct test of the jet-veto resummation framework in the Z+1-jet process.

Boughezal, Radja; Liu, Xiaohui

2015-01-01T23:59:59.000Z

397

Final Report: AST-0613577 "Experimental study of magnetic bubble expansion as a model for extragalactic radio lobes"  

SciTech Connect (OSTI)

Final report for project "Experimental study of magnetic bubble expansion as a model for extragalactic radio lobes" supported by NSF/DOE Joint Program in Basic Plasma Science.

Lynn, Alan [University of New Mexico

2011-02-18T23:59:59.000Z

398

Nuclear reactor construction with bottom supported reactor vessel  

DOE Patents [OSTI]

An improved liquid metal nuclear reactor construction has a reactor core and a generally cylindrical reactor vessel for holding a large pool of low pressure liquid metal coolant and housing the core within the pool. The reactor vessel has an open top end, a closed flat bottom end wall and a continuous cylindrical closed side wall interconnecting the top end and bottom end wall. The reactor also has a generally cylindrical concrete containment structure surrounding the reactor vessel and being formed by a cylindrical side wall spaced outwardly from the reactor vessel side wall and a flat base mat spaced below the reactor vessel bottom end wall. A central support pedestal is anchored to the containment structure base mat and extends upwardly therefrom to the reactor vessel and upwardly therefrom to the reactor core so as to support the bottom end wall of the reactor vessel and the lower end of the reactor core in spaced apart relationship above the containment structure base mat. Also, an annular reinforced support structure is disposed in the reactor vessel on the bottom end wall thereof and extends about the lower end of the core so as to support the periphery thereof. In addition, an annular support ring having a plurality of inward radially extending linear members is disposed between the containment structure base mat and the bottom end of the reactor vessel wall and is connected to and supports the reactor vessel at its bottom end on the containment structure base mat so as to allow the reactor vessel to expand radially but substantially prevent any lateral motions that might be imposed by the occurrence of a seismic event. The reactor construction also includes a bed of insulating material in sand-like granular form, preferably being high density magnesium oxide particles, disposed between the containment structure base mat and the bottom end wall of the reactor vessel and uniformly supporting the reactor vessel at its bottom end wall on the containment structure base mat so as to insulate the reactor vessel bottom end wall from the containment structure base mat and allow the reactor vessel bottom end wall to freely expand as it heats up while providing continuous support thereof. Further, a deck is supported upon the side wall of the containment structure above the top open end of the reactor vessel, and a plurality of serially connected extendible and retractable annular bellows extend between the deck and the top open end of the reactor vessel and flexibly and sealably interconnect the reactor vessel at its top end to the deck. An annular guide ring is disposed on the containment structure and extends between its side wall and the top open end of the reactor vessel for providing lateral support of the reactor vessel top open end by limiting imposition of lateral loads on the annular bellows by the occurrence of a lateral seismic event.

Sharbaugh, John E. (Bullskin Township, Fayette County, PA)

1987-01-01T23:59:59.000Z

399

MULTIWAVELENGTH OBSERVATIONS OF THE SS 433 JETS  

SciTech Connect (OSTI)

We present observations of the SS 433 jets using the Chandra High Energy Transmission Grating Spectrometer with contemporaneous optical and Very Long Baseline Array observations. The X-ray and optical emission line regions are found to be related but not coincident as the optical line emission persists for days while the X-ray emission lines fade in less than 5000 s. The line Doppler shifts from the optical and X-ray lines match well, indicating that they are less than 3 × 10{sup 14} cm apart. The jet Doppler shifts show aperiodic variations that could result from shocks in interactions with the local environment. These perturbations are consistent with a change in jet direction but not jet speed. The proper motions of the radio knots match the kinematic model only if the distance to SS 433 is 4.5 ± 0.2 kpc. Observations during eclipse show that the occulted emission is very hard, seen only above 2 keV and rising to comprise >50% of the flux at 8 keV. The soft X-ray emission lines from the jet are not blocked, constraining the jet length to ?> 2 × 10{sup 12} cm. The base jet density is in the range 10{sup 10-13} cm{sup –3}, in contrast to our previous estimate based on the Si XIII triplet, which is likely to have been affected by UV de-excitation. There is a clear overabundance of Ni by a factor of about 15 relative to the solar value, which may have resulted from an unusual supernova that formed the compact object.

Marshall, Herman L.; Canizares, Claude R.; Schulz, Norbert S.; Nowak, Michael [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Hillwig, Todd [Department of Physics and Astronomy, Valparaiso University, Valparaiso, IN 46383 (United States); Mioduszewski, Amy; Rupen, Michael [NRAO, P.O. Box 2, Socorro, NM 87801 (United States); Heinz, Sebastian, E-mail: hermanm@space.mit.edu, E-mail: crc@space.mit.edu, E-mail: nss@space.mit.edu, E-mail: mnowak@space.mit.edu, E-mail: todd.hillwig@valpo.edu, E-mail: amiodusz@nrao.edu, E-mail: mrupen@aoc.nrao.edu, E-mail: heinzs@astro.wisc.edu [Astronomy Department, 5408 Sterling Hall, University of Wisconsin, Madison, WI 53706 (United States)

2013-09-20T23:59:59.000Z

400

Spherical torus fusion reactor  

DOE Patents [OSTI]

A fusion reactor is provided having a near spherical-shaped plasma with a modest central opening through which straight segments of toroidal field coils extend that carry electrical current for generating a toroidal magnet plasma confinement fields. By retaining only the indispensable components inboard of the plasma torus, principally the cooled toroidal field conductors and in some cases a vacuum containment vessel wall, the fusion reactor features an exceptionally small aspect ratio (typically about 1.5), a naturally elongated plasma cross section without extensive field shaping, requires low strength magnetic containment fields, small size and high beta. These features combine to produce a spherical torus plasma in a unique physics regime which permits compact fusion at low field and modest cost.

Peng, Yueng-Kay M. (Oak Ridge, TN)

1989-01-01T23:59:59.000Z

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.


401

Nuclear divisional reactor  

SciTech Connect (OSTI)

A nuclear divisional reactor including a reactor core having side and top walls, a heat exchanger substantially surrounding the core, the heat exchanger including a plurality of separate fluid holding and circulating chambers each in contact with a portion of the core, control rod means associated with the core and external of the heat exchanger including control rods and means for moving said control rods, each of the chambers having separate means for delivering and removing fluid therefrom, separate means associated with each of the delivering and removing means for producing useable energy external of the chambers, each of the means for producing useable energy having separate variable capacity energy outputs thereby making available a plurality of individual sources of useable energy of varying degrees.

Administratrix, A.P.; Rugh, J.L.

1982-11-02T23:59:59.000Z

402

Nuclear reactor safety device  

DOE Patents [OSTI]

A safety device is described for use in a nuclear reactor for axially repositioning a control rod with respect to the reactor core in the event of a thermal excursion. It comprises a laminated strip helically configured to form a tube, said tube being in operative relation to said control rod. The laminated strip is formed of at least two materials having different thermal coefficients of expansion, and is helically configured such that the material forming the outer lamina of the tube has a greater thermal coefficient of expansion than the material forming the inner lamina of said tube. In the event of a thermal excursion the laminated strip will tend to curl inwardly so that said tube will increase in length, whereby as said tube increases in length it exerts a force on said control rod to axially reposition said control rod with respect to said core.

Hutter, E.

1983-08-15T23:59:59.000Z

403

Fusion reactor pumped laser  

DOE Patents [OSTI]

A nuclear pumped laser capable of producing long pulses of very high power laser radiation is provided. A toroidal fusion reactor provides energetic neutrons which are slowed down by a moderator. The moderated neutrons are converted to energetic particles capable of pumping a lasing medium. The lasing medium is housed in an annular cell surrounding the reactor. The cell includes an annular reflecting mirror at the bottom and an annular output window at the top. A neutron reflector is disposed around the cell to reflect escaping neutrons back into the cell. The laser radiation from the annular window is focused onto a beam compactor which generates a single coherent output laser beam. 10 figs.

Jassby, D.L.

1987-09-04T23:59:59.000Z

404

E-Print Network 3.0 - african easterly jet Sample Search Results  

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

EasterlyEasterly Jet (AEJ) :Jet (AEJ) : Vent thermique d'Est principalement li ... Nord lors de la priode de mousson. TropicalTropical EasterlyEasterly Jet (TEJ) :Jet (TEJ)...

405

Exploring Light's Interactions with Bubbles and Light Absorbers in Photoelectrochemical Devices using Ray Tracing  

SciTech Connect (OSTI)

Ray tracing was used to perform optical optimization of arrays of photovoltaic microrods and explore the interaction between light and bubbles of oxygen gas on the surface of the microrods. The incident angle of light was varied over a wide range. The percent of incident light absorbed by the microrods and reflected by the bubbles was computed over this range. It was found that, for the 10 ?m diameter, 100 ?m tall SrTiO{sub 3} microrods simulated in the model, the optimal center-­?to-­?center spacing was 14 ?m for a square grid. This geometry produced 75% average and 90% maximum absorbance. For a triangular grid using the same microrods, the optimal center-­?to-­?center spacing was 14 ?m. This geometry produced 67% average and 85% maximum absorbance. For a randomly laid out grid of 5 ?m diameter, 100 ?m tall SrTiO! microrods with an average center-­?to-­?center spacing of 20 ?m, the average absorption was 23% and the maximum absorption was 43%. For a 50% areal coverage fraction of bubbles on the absorber surface, between 2%-­?20% of the incident light energy was reflected away from the rods by the bubbles, depending upon incident angle and bubble morphology.

Stevens, John

2013-12-31T23:59:59.000Z

406

Thin-shell bubbles and information loss problem in anti de Sitter background  

E-Print Network [OSTI]

We study the motion of thin-shell bubbles and their tunneling in anti de Sitter (AdS) background. We are interested in the case when the outside of a shell is a Schwarzschild-AdS space (false vacuum) and the inside of it is an AdS space with a lower vacuum energy (true vacuum). If a collapsing true vacuum bubble is created, classically it will form a Schwarzschild-AdS black hole. However, this collapsing bubble can tunnel to a bouncing bubble that moves out to spatial infinity. Then, although the classical causal structure of a collapsing true vacuum bubble has the singularity and the event horizon, quantum mechanically the wavefunction has support for a history without any singularity nor event horizon which is mediated by the non-perturbative, quantum tunneling effect. This may be regarded an explicit example that shows the unitarity of an asymptotic observer in AdS, while a classical observer who only follows the most probable history effectively lose information due to the formation of an event horizon.

Misao Sasaki; Dong-han Yeom

2014-12-25T23:59:59.000Z

407

Computational Fluid Dynamics Simulation of Fluidized Bed Polymerization Reactors  

SciTech Connect (OSTI)

Fluidized beds (FB) reactors are widely used in the polymerization industry due to their superior heat- and mass-transfer characteristics. Nevertheless, problems associated with local overheating of polymer particles and excessive agglomeration leading to FB reactors defluidization still persist and limit the range of operating temperatures that can be safely achieved in plant-scale reactors. Many people have been worked on the modeling of FB polymerization reactors, and quite a few models are available in the open literature, such as the well-mixed model developed by McAuley, Talbot, and Harris (1994), the constant bubble size model (Choi and Ray, 1985) and the heterogeneous three phase model (Fernandes and Lona, 2002). Most these research works focus on the kinetic aspects, but from industrial viewpoint, the behavior of FB reactors should be modeled by considering the particle and fluid dynamics in the reactor. Computational fluid dynamics (CFD) is a powerful tool for understanding the effect of fluid dynamics on chemical reactor performance. For single-phase flows, CFD models for turbulent reacting flows are now well understood and routinely applied to investigate complex flows with detailed chemistry. For multiphase flows, the state-of-the-art in CFD models is changing rapidly and it is now possible to predict reasonably well the flow characteristics of gas-solid FB reactors with mono-dispersed, non-cohesive solids. This thesis is organized into seven chapters. In Chapter 2, an overview of fluidized bed polymerization reactors is given, and a simplified two-site kinetic mechanism are discussed. Some basic theories used in our work are given in detail in Chapter 3. First, the governing equations and other constitutive equations for the multi-fluid model are summarized, and the kinetic theory for describing the solid stress tensor is discussed. The detailed derivation of DQMOM for the population balance equation is given as the second section. In this section, monovariate population balance, bivariate population balance, aggregation and breakage equation and DQMOM-Multi-Fluid model are described. In the last section of Chapter 3, numerical methods involved in the multi-fluid model and time-splitting method are presented. Chapter 4 is based on a paper about application of DQMOM to polydisperse gas-solid fluidized beds. Results for a constant aggregation and breakage kernel and a kernel developed from kinetic theory are shown. The effect of the aggregation success factor and the fragment distribution function are investigated. Chapter 5 shows the work on validation of mixing and segregation phenomena in gas-solid fluidized beds with a binary mixture or a continuous size distribution. The simulation results are compared with available experiment data and discrete-particle simulation. Chapter 6 presents the project with Univation Technologies on CFD simulation of a Polyethylene pilot-scale FB reactor, The fluid dynamics, mass/heat transfer and particle size distribution are investigated through CFD simulation and validated with available experimental data. The conclusions of this study and future work are discussed in Chapter 7.

Rong Fan

2006-08-09T23:59:59.000Z

408

Thermionic Reactor Design Studies  

SciTech Connect (OSTI)

During the 1960's and early 70's the author performed extensive design studies, analyses, and tests aimed at thermionic reactor concepts that differed significantly from those pursued by other investigators. Those studies, like most others under Atomic Energy Commission (AEC and DOE) and the National Aeronautics and Space Administration (NASA) sponsorship, were terminated in the early 1970's. Some of this work was previously published, but much of it was never made available in the open literature. U.S. interest in thermionic reactors resumed in the early 80's, and was greatly intensified by reports about Soviet ground and flight tests in the late 80's. This recent interest resulted in renewed U.S. thermionic reactor development programs, primarily under Department of Defense (DOD) and Department of Energy (DOE) sponsorship. Since most current investigators have not had an opportunity to study all of the author's previous work, a review of the highlights of that work may be of value to them. The present paper describes some of the author's conceptual designs and their rationale, and the special analytical techniques developed to analyze their performance. The basic designs, first published in 1963, are based on single-cell converters, either double-ended diodes extending over the full height of the reactor core or single-ended diodes extending over half the core height. In that respect they are similar to the thermionic fuel elements employed in the Topaz-2 reactor subsequently developed in the Soviet Union, copies of which were recently imported by the U.S. As in the Topaz-2 case, electrically heated steady-state performance tests of the converters are possible before fueling. Where the author's concepts differed from the later Topaz-2 design was in the relative location of the emitter and the collector. Placing the fueled emitter on the outside of the cylindrical diodes permits much higher axial conductances to reduce ohmic losses in the electrodes of full-core-height diodes. Moreover, placing the fuel on the outside of the diode makes possible reactors with much higher fuel volume fractions, which enable power-flattened fast reactors scalable to very low power levels without the need for life-limiting hydride moderators or the use of efficiency-limiting driver fuel. In addition, with the fuel on the outside its swelling does not increase the emitter diameter or reduce the interelectrode gap. This should permit long lifetimes even with closer spacings, which can significantly improve the system efficiences. This was confirmed by coupled neutronic, thermal, thermionic, and electrical system analyses - some of which are presented in this paper - and by subsequent experiments. A companion paper presented next describes the fabrication and testing of full-scale converter elements, both fueled and unfueled, and summarizes the test results obtained. There is a duplicate copy in the file.

Schock, Alfred

1994-06-01T23:59:59.000Z

409

Nuclear reactor engineering: Reactor systems engineering. Fourth edition, Volume Two  

SciTech Connect (OSTI)

This new edition of this classic reference combines broad yet in-depth coverage of nuclear engineering principles with practical descriptions of their application in the design and operation of nuclear power plants. Extensively updated, the fourth edition includes new materials on reactor safety and risk analysis, regulation, fuel management, waste management and operational aspects of nuclear power. This volume contains the following: the systems concept, design decisions, and information tools; energy transport; reactor fuel management and energy cost considerations; environmental effects of nuclear power and waste management; nuclear reactor safety and regulation; power reactor systems; plant operations; and advanced plants and the future.

Glasstone, S.; Sesonske, A.

1994-12-31T23:59:59.000Z

410

A study of the self-oscillating jet impingement nozzle  

E-Print Network [OSTI]

wave and flow fluctuations that need no external input. The new oscillating jet when used for impingement surface transport was labeled the Self-Oscillating Jet Impingement Nozzle. The objectives of this research were to characterize the gains in heat...

Chinnock, Paul Scott

1993-01-01T23:59:59.000Z

411

Applications of Underexpanded Jets in Hypersonic Aerothermodynamics Research  

E-Print Network [OSTI]

Applications of Underexpanded Jets in Hypersonic Aerothermodynamics Research Vladimir V. Riabov Abstract. A method of underexpanded hypersonic viscous jets has been developed to acquire experimental parameters are revealed. In the case of hypersonic stabilization, the Reynolds number and temperature factor

Riabov, Vladimir V.

412

Feedback control of flow separation using synthetic jets  

E-Print Network [OSTI]

The primary goal of this research is to assess the effect of synthetic jets on flow separation and provide a feedback control strategy for flow separation using synthetic jets. The feedback control synthesis is conducted based upon CFD simulation...

Kim, Kihwan

2006-04-12T23:59:59.000Z

413

Images in Emergency Medicine: Irritant Contact Dermatitis from Jet Fuel  

E-Print Network [OSTI]

and penetration of JP-8 jet fuel and its components. Toxicoland other kerosene-based fuels have been shown to cause skinContact Dermatitis from Jet Fuel Christopher C. Trigger, MD

Trigger, Christopher C; Eilbert, Wesley

2009-01-01T23:59:59.000Z

414

Active noise control of supersonic impinging jet using pulsed microjets  

E-Print Network [OSTI]

This thesis concerns an active noise control of supersonic impinging jet flow using unsteady microjet injection. Supersonic impinging jet involves several problems such as lift loss, ground erosion, significant noise ...

Hong, Seung Hyuck

2009-01-01T23:59:59.000Z

415

Use Steam Jet Ejectors or Thermocompressors to Reduce Venting...  

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

Steam Jet Ejectors or Thermocompressors to Reduce Venting of Low-Pressure Steam Use Steam Jet Ejectors or Thermocompressors to Reduce Venting of Low-Pressure Steam This tip sheet...

416

Mixing enhancement by use of swirling jets  

SciTech Connect (OSTI)

It has been proposed that the mixing of fuel with air in the combustor of scramjet engines might be enhanced by the addition of swirl to the fuel jet prior to injection. This study investigated the effects of swirl on the mixing of a 30 deg wall jet into a Mach 2 flow. Cases with swirl and without swirl were investigated, with both helium and air simulating the fuel. Rayleigh scattering was used to visualize the flow, and seeding the fuel with water allowed it to be traced through the main flow. The results show that the addition of swirl to the fuel jet causes the fuel to mix more rapidly with the main flow, that larger amounts of swirl increase this effect, and that helium spreads better into the main flow than air. 12 refs.

Kraus, D.K.; Cutler, A.D.

1993-01-01T23:59:59.000Z

417

Extragalactic jets on subpc and large scales  

E-Print Network [OSTI]

Jets can be probed in their innermost regions (d~0.1 pc) through the study of the relativistically-boosted emission of blazars. On the other extreme of spatial scales, the study of structure and dynamics of extragalactic relativistic jets received renewed impulse after the discovery, made by Chandra, of bright X-ray emission from regions at distances larger than hundreds of kpc from the central engine. At both scales it is thus possible to infer some of the basic parameters of the flow (speed, density, magnetic field intensity, power). After a brief review of the available observational evidence, I discuss how the comparison between the physical quantities independently derived at the two scales can be used to shed light on the global dynamics of the jet, from the innermost regions to the hundreds of kpc scale.

F. Tavecchio

2007-08-20T23:59:59.000Z

418

On the Misalignment of Jets in Microquasars  

E-Print Network [OSTI]

We discuss the timescales for alignment of black hole and accretion disc spins in the context of binary systems. We show that for black holes that are formed with substantial angular momentum, the alignment timescales are likely to be at least a substantial fraction of the systems' lifetimes. This result explains the observed misalignment of the disc and the jet in the microquasar GRO J 1655-40 and in SAX J 1819-2525 as being likely due to the Bardeen-Petterson effect. We discuss the implications of these results on the mass estimate for GRS 1915+105, which has assumed the jet is perpendicular to the orbital plane of the system and may hence be an underestimate. We show that the timescales for the spin alignment in Cygnus X-3 are consistent with the likely misalignment of disc and jet in that system, and that this is suggested by the observational data.

Thomas J. Maccarone

2002-09-05T23:59:59.000Z

419

Jet Structure in Heavy Ion Collisions  

E-Print Network [OSTI]

We review recent theoretical developments in the study of the structure of jets that are produced in ultra relativistic heavy ion collisions. The core of the review focusses on the dynamics of the parton cascade that is induced by the interactions of a fast parton crossing a quark-gluon plasma. We recall the basic mechanisms responsible for medium induced radiation, underline the rapid disappearance of coherence effects, and the ensuing probabilistic nature of the medium induced cascade. We discuss how large radiative corrections modify the classical picture of the gluon cascade, and how these can be absorbed in a renormalization of the jet quenching parameter $\\hat q $. Then, we analyze the (wave)-turbulent transport of energy along the medium induced cascade, and point out the main characteristics of the angular structure of such a cascade. Finally, color decoherence of the in-cone jet structure is discussed. Modest contact with phenomenology is presented towards the end of the review.

Blaizot, Jean-Paul

2015-01-01T23:59:59.000Z

420

Designing Reactors to Facilitate Decommissioning  

SciTech Connect (OSTI)

Critics of nuclear power often cite issues with tail-end-of-the-fuel-cycle activities as reasons to oppose the building of new reactors. In fact, waste disposal and the decommissioning of large nuclear reactors have proven more challenging than anticipated. In the early days of the nuclear power industry the design and operation of various reactor systems was given a great deal of attention. Little effort, however, was expended on end-of-the-cycle activities, such as decommissioning and disposal of wastes. As early power and test reactors have been decommissioned difficulties with end-of-the-fuel-cycle activities have become evident. Even the small test reactors common at the INEEL were not designed to facilitate their eventual decontamination, decommissioning, and dismantlement. The results are that decommissioning of these facilities is expensive, time consuming, relatively hazardous, and generates large volumes of waste. This situation clearly supports critics concerns about building a new generation of power reactors.

Richard H. Meservey

2006-06-01T23:59:59.000Z

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

QCD Jet Rates with the Inclusive Generalized kt Algorithms  

E-Print Network [OSTI]

We derive generating functions, valid to next-to-double logarithmic accuracy, for QCD jet rates according to the inclusive forms of the kt, Cambridge/Aachen and anti-kt algorithms, which are equivalent at this level of accuracy. We compare the analytical results with jet rates and average jet multiplicities from the SHERPA event generator, and study the transition between Poisson-like and staircase-like behaviour of jet ratios.

Erik Gerwick; Ben Gripaios; Steffen Schumann; Bryan Webber

2013-04-15T23:59:59.000Z

422

On the Counter-jet Emission in GRB Afterglows  

SciTech Connect (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

423

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

2009-10-08T23:59:59.000Z

424

First Results of the Testing of the Liquid Gallium Jet Limiter Concept for ISTTOK  

SciTech Connect (OSTI)

The use of liquid metals as plasma facing components in tokamaks has recently experienced a renewed interest stimulated by their advantages to the development of a fusion reactor. Liquid metals have been proposed to solve problems related to the erosion and neutronic activation of solid walls submitted to high power loads allowing an efficient heat exhaustion from fusion devices. Presently the most promising materials are Lithium and Gallium. ISTTOK, a small size tokamak, will be used to test the behavior of a liquid Gallium jet in the vacuum chamber and its influence on the plasma. This paper presents a description of the conceived setup as well as experimental results. The liquid Gallium jet is generated by hydrostatic pressure and injected in a radial position close to a moveable stainless steel limiter. Both the jet and the limiter positions are variable allowing for a controlled exposure of the liquid Gallium to the edge plasma. The main components of the Gallium loop are a MHD pump, the liquid metal injector and a filtering system. The MHD pump is of the induction type, based on rotating permanent magnets. The injector is build from a stainless steel pipe ended by a shaping nozzle. A setup has been developed to introduce oxide-free Gallium inside the loop's main supply tank. Raw liquid metal is placed inside a chamber heated and degassed under high vacuum while clean Gallium is extracted from the main body of the liquefied metal. Prior to installation on the tokamak, the experimental rig has been implemented using a Pyrex tube as test chamber to investigate the stability of the Gallium jet and its break-up length for several nozzle sizes. Results are presented in this paper. This rig was also useful to assess the behavior of the overall implemented apparatus.

Gomes, R. B.; Fernandes, H.; Silva, C.; Borba, D.; Carvalho, B.; Varandas, C. [Associacao EURATOM/IST, Centro de FuSao Nuclear, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Lielausis, O.; Klyukin, A.; Platacis, E.; Mikelsons, A.; Platnieks, I. [Association EURATOM/University of Latvia, Institute of Physics, 32 Miera Str., Salaspils, LV-2169 (Latvia)

2006-12-04T23:59:59.000Z

425

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

SciTech Connect (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

426

THE HELICAL JET OF THE VELA PULSAR  

SciTech Connect (OSTI)

We have studied the fascinating dynamics of the nearby Vela pulsar's nebula in a campaign comprising 11 40 ks observations with the Chandra X-Ray Observatory. The deepest images yet revealed the shape, structure, and motion of the 2 arcmin long pulsar jet. We find that the jet's shape and dynamics are remarkably consistent with those of a steadily turning helix projected on the sky. We discuss possible implications of our results, including free precession of the neutron star and MHD instability scenarios.

Durant, Martin; Kargaltsev, Oleg [University of Florida, 211 Bryant Space Science Center, Gainesville, FL (United States)] [University of Florida, 211 Bryant Space Science Center, Gainesville, FL (United States); Pavlov, George G. [Pennsylvania State University, 525 Davey Lab, University Park, PA (United States)] [Pennsylvania State University, 525 Davey Lab, University Park, PA (United States); Kropotina, Julia; Levenfish, Kseniya, E-mail: mdurant@sri.utoronto.ca [St.-Petersburg State Polytechnical University, Polytekhnicheskaya ul. 29, St.-Petersburg, 195251 (Russian Federation)] [St.-Petersburg State Polytechnical University, Polytekhnicheskaya ul. 29, St.-Petersburg, 195251 (Russian Federation)

2013-02-15T23:59:59.000Z

427

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

428

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. 17 figs.

Claunch, S.D.; Farrington, R.B.

1997-02-04T23:59:59.000Z

429

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

430

Entrainment and mixing properties of multiphase plumes: Experimental studies on turbulence and scalar structure of a bubble plume  

E-Print Network [OSTI]

, the velocity and concentration field measurements using the developed two-phase PIV and LIF methods are applied for a bubble plume in a density-stratified ambient. The turbulent flow characteristics induced by a bubble plume in a stratified ambient water...

Seol, Dong Guan

2009-05-15T23:59:59.000Z

431

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

SciTech Connect (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

432

A one-way coupled, EulerLagrangian simulation of bubble coalescence in a turbulent pipe flow  

E-Print Network [OSTI]

modifies the speed of sound in the bubbly mixture, which has implications for marine acoustic signatures. Gas­liquid flow at microgravity conditions ­ I. Dispersed bubble and slug flow. Int. J. Multiphase- ical in many heat transfer problems where liquid water contacting a hot surface boils and the resulting

Mahesh, Krishnan

433

High-resolution variations in size, number and arrangement of air bubbles in the EPICA DML (Antarctica) ice core  

E-Print Network [OSTI]

(Antarctica) ice core Verena BENDEL,1Ã Kai J. UELTZHO¨ FFER,2 Johannes FREITAG,3 Sepp KIPFSTUHL,3 Werner F bubbles in the EPICA Dronning Maud Land (EDML) (Antarctica) ice core, down to the end of the bubble with the palaeo-temperature proxy, dd18 O, and the dust concentration, which means that in Holocene ice

Garbe, Christoph S.

434

Effects of intermittent entrainment of air bubbles by breaking wind waves on ocean reflectance and underwater light field  

E-Print Network [OSTI]

Effects of intermittent entrainment of air bubbles by breaking wind waves on ocean reflectance, 2000]. The intermittent nature of air entrainment by breaking waves manifests itself as dramatic, Polish Academy of Sciences, Sopot, Poland Abstract. Light-scattering properties of air bubbles suspended

Stramski, Dariusz

435

Large Eddy Simulations of Jet Flow Interactions Within Rod Bundles  

E-Print Network [OSTI]

The present work investigates the turbulent jet flow mixing of downward impinging jets within a staggered rod bundle based on previous experimental work. The two inlet jets had Reynold's numbers of 11,160 and 6,250 and were chosen to coincide...

Salpeter, Nathaniel O.

2010-07-14T23:59:59.000Z

436

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

SciTech Connect (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

437

Hydrodynamics of bubble columns with application to Fischer-Tropsch synthesis  

E-Print Network [OSTI]

produced hold-up vaiues similar to those of pure liquids, whereas. exper r rent, zvith parafiiu waxes (FT-200 ancl PT-:300) at 265 'C produced iigh hold- p values ar. d large aznounts of foam. But, at 200 'C lov; hold-up raiues were c'iitaired anc small... by the column diameter and superficial gas velocity. In the bubbly flow regime?bubbles may be small and spherical, or larger and non spherical because of the flow of liquid around them. As the superficial gas velocity is increased slug flov' is developed...

Raphael, Matheo Lue

1988-01-01T23:59:59.000Z

438

The effect of bubble growth dynamics on the performance of a gas evolving electrode  

E-Print Network [OSTI]

) studied the growth of electrolytic bubbles on platinum, copper, iron and nickel electrodes of di Ffer- ent diameters at various constant current levels. They used high speed photography and a series of dry cell batteries for a d. c. power source...THE EFFECT OF BUBBLE GRONTH D'rgiAMI CS ON THE PE' FOi&ilANCE OF A GAS EVOLVING ELECTRODE A Thesis By MOHAMMAD SHAMSUL HAgUE Submitted to the Graduate College of the Texas Alg& University in Partial ful fi llment of the requirements...

Haque, Mohammad Shamsul

1967-01-01T23:59:59.000Z

439

Progress Update: Reactor Disassembly Grouting  

SciTech Connect (OSTI)

Grouting the P&R reactors in order to remove these basins as an environmental threat. This will end the Cold War legacy and end the environmental footprint.

Cody, Tom

2010-01-01T23:59:59.000Z

440

Neutrino Oscillation Studies with Reactors  

E-Print Network [OSTI]

Nuclear reactors are one of the most intense, pure, controllable, cost-effective, and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavors are quantum mechanical mixtures. Over the past several decades reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle $\\theta_{13}$. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

Petr Vogel; Liangjian Wen; Chao Zhang

2015-03-03T23:59:59.000Z

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.


441

Neutrino Oscillation Studies with Reactors  

E-Print Network [OSTI]

Nuclear reactors are one of the most intense, pure, controllable, cost-effective, and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavors are quantum mechanical mixtures. Over the past several decades reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle $\\theta_{13}$. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

Vogel, Petr; Zhang, Chao

2015-01-01T23:59:59.000Z

442

Thermonuclear Reflect AB-Reactor  

E-Print Network [OSTI]

The author offers a new kind of thermonuclear reflect reactor. The remarkable feature of this new reactor is a three net AB reflector, which confines the high temperature plasma. The plasma loses part of its energy when it contacts with the net but this loss can be compensated by an additional permanent plasma heating. When the plasma is rarefied (has a small density), the heat flow to the AB reflector is not large and the temperature in the triple reflector net is lower than 2000 - 3000 K. This offered AB-reactor has significantly less power then the currently contemplated power reactors with magnetic or inertial confinement (hundreds-thousands of kW, not millions of kW). But it is enough for many vehicles and ships and particularly valuable for tunnelers, subs and space apparatus, where air to burn chemical fuel is at a premium or simply not available. The author has made a number of innovations in this reactor, researched its theory, developed methods of computation, made a sample computation of typical project. The main point of preference for the offered reactor is its likely cheapness as a power source. Key words: Micro-thermonuclear reactor, Multi-reflex AB-thermonuclear reactor, Self-magnetic AB-thermonuclear reactor, aerospace thermonuclear engine.

Alexander Bolonkin

2008-03-26T23:59:59.000Z

443

Light Water Reactor Sustainability Newsletter  

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

hydraulics software RELAP-7 (which is under development in the Light Water Reactor Sustainability LWRS Program). A novel interaction between the probabilistic part (i.e., RAVEN)...

444

Light Water Reactor Sustainability Newsletter  

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

30-35, August 2012. Clayton, D. A. and M. S. Hileman, 2012, Light Water Reactor Sustainability Non-Destructive Evaluation for Concrete Research and Development Roadmap, ORNLTM-...

445

Progress Update: Reactor Disassembly Grouting  

ScienceCinema (OSTI)

Grouting the P&R reactors in order to remove these basins as an environmental threat. This will end the Cold War legacy and end the environmental footprint.

Cody, Tom

2012-06-14T23:59:59.000Z

446

NONLINEAR RESPONSE OF A SPHERICAL BUBBLE TO A MULTI-FREQUENCY EXCITATION NAYFEH A.H. and MOOK D.T.  

E-Print Network [OSTI]

nonlinear radial oscillations of a spherical gas bubble are / 6 / where the dot denotes d i f f e r e n t iNONLINEAR RESPONSE OF A SPHERICAL BUBBLE TO A MULTI-FREQUENCY EXCITATION NAYFEH A.H. and MOOK D of a spherical gas bubble immersed in a s l i g h t l y compressible f l u i d . The mass of the gas bubble

Paris-Sud XI, Université de

447

A Spouted Bed Reactor Monitoring System for Particulate Nuclear Fuel  

SciTech Connect (OSTI)

Conversion and coating of particle nuclear fuel is performed in spouted (fluidized) bed reactors. The reactor must be capable of operating at temperatures up to 2000°C in inert, flammable, and coating gas environments. The spouted bed reactor geometry is defined by a graphite retort with a 2.5 inch inside diameter, conical section with a 60° included angle, and a 4 mm gas inlet orifice diameter through which particles are removed from the reactor at the completion of each run. The particles may range from 200 µm to 2 mm in diameter. Maintaining optimal gas flow rates slightly above the minimum spouting velocity throughout the duration of each run is complicated by the variation of particle size and density as conversion and/or coating reactions proceed in addition to gas composition and temperature variations. In order to achieve uniform particle coating, prevent agglomeration of the particle bed, and monitor the reaction progress, a spouted bed monitoring system was developed. The monitoring system includes a high-sensitivity, low-response time differential pressure transducer paired with a signal processing, data acquisition, and process control unit which allows for real-time monitoring and control of the spouted bed reactor. The pressure transducer is mounted upstream of the spouted bed reactor gas inlet. The gas flow into the reactor induces motion of the particles in the bed and prevents the particles from draining from the reactor due to gravitational forces. Pressure fluctuations in the gas inlet stream are generated as the particles in the bed interact with the entering gas stream. The pressure fluctuations are produced by bulk movement of the bed, generation and movement of gas bubbles through the bed, and the individual motion of particles and particle subsets in the bed. The pressure fluctuations propagate upstream to the pressure transducer where they can be monitored. Pressure fluctuation, mean differential pressure, gas flow rate, reactor operating temperature data from the spouted bed monitoring system are used to determine the bed operating regime and monitor the particle characteristics. Tests have been conducted to determine the sensitivity of the monitoring system to the different operating regimes of the spouted particle bed. The pressure transducer signal response was monitored over a range of particle sizes and gas flow rates while holding bed height constant. During initial testing, the bed monitoring system successfully identified the spouting regime as well as when particles became interlocked and spouting ceased. The particle characterization capabilities of the bed monitoring system are currently being tested and refined. A feedback control module for the bed monitoring system is currently under development. The feedback control module will correlate changes in the bed response to changes in the particle characteristics and bed spouting regime resulting from the coating and/or conversion process. The feedback control module will then adjust the gas composition, gas flow rate, and run duration accordingly to maintain the bed in the desired spouting regime and produce optimally coated/converted particles.

D. S. Wendt; R. L. Bewley; W. E. Windes

2007-06-01T23:59:59.000Z

448

Acoustic emission associated with the bursting of a gas bubble at the free surface of a non-newtonian fluid  

E-Print Network [OSTI]

We report experimental measurements of the acoustic emission associated with the bursting of a gas bubble at the free surface of a non-newtonian fluid. On account of the viscoelastic properties of the fluid, the bubble is generally elongated. The associated frequency and duration of the acoustic signal are discussed with regard to the shape of the bubble and successfully accounted for by a simple linear model. The acoustic energy exhibits a high sensitivity to the dynamics of the thin film bursting, which demonstrates that, in practice, it is barely possible to deduce from the acoustic measurements the total amount of energy released by the event. Our experimental findings provide clues for the understanding of the signals from either volcanoes or foams, where one observes respectively, the bursting of giant bubbles at the free surface of lava and bubble bursting avalanches.

Thibaut Divoux; Valérie Vidal; Francisco Melo; Jean-Christophe Géminard

2008-07-01T23:59:59.000Z

449

Studying Z/gamma*+Jet Production  

SciTech Connect (OSTI)

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

450

Reactor coolant pump flywheel  

DOE Patents [OSTI]

A flywheel for a pump, and in particular a flywheel having a number of high density segments for use in a nuclear reactor coolant pump. The flywheel includes an inner member and an outer member. A number of high density segments are provided between the inner and outer members. The high density segments may be formed from a tungsten based alloy. A preselected gap is provided between each of the number of high density segments. The gap accommodates thermal expansion of each of the number of segments and resists the hoop stress effect/keystoning of the segments.

Finegan, John Raymond; Kreke, Francis Joseph; Casamassa, John Joseph

2013-11-26T23:59:59.000Z

451

Reactor refueling containment system  

DOE Patents [OSTI]

A method of refueling a nuclear reactor is disclosed whereby the drive mechanism is disengaged and removed by activating a jacking mechanism that raises the closure head. The area between the barrier plate and closure head is exhausted through the closure head penetrations. The closure head, upper drive mechanism, and bellows seal are lifted away and transported to a safe area. The barrier plate acts as the primary boundary and each drive and control rod penetration has an elastomer seal preventing excessive tritium gases from escaping. The individual instrumentation plugs are disengaged allowing the corresponding fuel assembly to be sealed and replaced. 2 figs.

Gillett, J.E.; Meuschke, R.E.

1995-05-02T23:59:59.000Z

452

Reactor refueling containment system  

DOE Patents [OSTI]

A method of refueling a nuclear reactor whereby the drive mechanism is disengaged and removed by activating a jacking mechanism that raises the closure head. The area between the barrier plate and closure head is exhausted through the closure head penetrations. The closure head, upper drive mechanism, and bellows seal are lifted away and transported to a safe area. The barrier plate acts as the primary boundary and each drive and control rod penetration has an elastomer seal preventing excessive tritium gases from escaping. The individual instrumentation plugs are disengaged allowing the corresponding fuel assembly to be sealed and replaced.

Gillett, James E. (Greensburg, PA); Meuschke, Robert E. (Pittsburgh, PA)

1995-01-01T23:59:59.000Z

453

Nuclear reactor control assembly  

SciTech Connect (OSTI)

This patent describes an assembly for providing global power control in a nuclear reactor having the core split into two halves. It comprises a disk assembly formed from at least two disks each machined with an identical surface hole pattern such that rotation of one disk relative to the other causes the hole pattern to open or close, the disk assembly being positioned substantially at the longitudinal center of and coaxial with the core halves; and means for rotating at least one of the disks relative to the other.

Negron, S.B.

1991-06-11T23:59:59.000Z

454

Nuclear reactor control apparatus  

SciTech Connect (OSTI)

Nuclear reactor core safety rod release apparatus comprises a control rod having a detent notch in the form of an annular peripheral recess at its upper end, a control rod support tube for raising and lowering the control rod under normal conditions, latches pivotally mounted on the control support tube with free ends thereof normally disposed in the recess in the control rod, and cam means for pivoting the latches out of the recess in the control rod when a scram condition occurs. One embodiment of the invention comprises an additonal magnetically-operated latch for releasing the control rod under two different conditions, one involving seismic shock.

Sridhar, B.N.

1981-08-28T23:59:59.000Z

455

Biparticle fluidized bed reactor  

DOE Patents [OSTI]

A fluidized bed reactor system which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase is described. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves. 3 figures.

Scott, C.D.

1993-12-14T23:59:59.000Z

456

Biparticle fluidized bed reactor  

DOE Patents [OSTI]

A fluidized bed reactor system utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves. 3 figs.

Scott, C.D.; Marasco, J.A.

1995-04-25T23:59:59.000Z

457

Nuclear reactor control apparatus  

DOE Patents [OSTI]

Nuclear reactor core safety rod release apparatus comprises a control rod having a detent notch in the form of an annular peripheral recess at its upper end, a control rod support tube for raising and lowering the control rod under normal conditions, latches pivotally mounted on the control support tube with free ends thereof normally disposed in the recess in the control rod, and cam means for pivoting the latches out of the recess in the control rod when a scram condition occurs. One embodiment of the invention comprises an additional magnetically-operated latch for releasing the control rod under two different conditions, one involving seismic shock.

Sridhar, Bettadapur N. (Cupertino, CA)

1983-11-01T23:59:59.000Z

458

Licensed reactor nuclear safety criteria applicable to DOE reactors  

SciTech Connect (OSTI)

The Department of Energy (DOE) Order DOE 5480.6, Safety of Department of Energy-Owned Nuclear Reactors, establishes reactor safety requirements to assure that reactors are sited, designed, constructed, modified, operated, maintained, and decommissioned in a manner that adequately protects health and safety and is in accordance with uniform standards, guides, and codes which are consistent with those applied to comparable licensed reactors. This document identifies nuclear safety criteria applied to NRC (Nuclear Regulatory Commission) licensed reactors. The titles of the chapters and sections of USNRC Regulatory Guide 1.70, Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants, Rev. 3, are used as the format for compiling the NRC criteria applied to the various areas of nuclear safety addressed in a safety analysis report for a nuclear reactor. In each section the criteria are compiled in four groups: (1) Code of Federal Regulations, (2) US NRC Regulatory Guides, SRP Branch Technical Positions and Appendices, (3) Codes and Standards, and (4) Supplemental Information. The degree of application of these criteria to a DOE-owned reactor, consistent with their application to comparable licensed reactors, must be determined by the DOE and DOE contractor.

Not Available

1991-04-01T23:59:59.000Z

459

Modular Pebble Bed Reactor High Temperature Gas Reactor  

E-Print Network [OSTI]

Modular Pebble Bed Reactor High Temperature Gas Reactor Andrew C Kadak Massachusetts Institute For 1150 MW Combined Heat and Power Station Oil Refinery Hydrogen Production Desalinization Plant VHTR/Graphite Discrimination system Damaged Sphere ContainerGraphiteReturn FuelReturn Fresh Fuel Container Spent Fuel Tank #12

460

Preliminary Study Using ForwardPreliminary Study Using Forward Reaction Control System JetsReaction Control System Jets  

E-Print Network [OSTI]

Preliminary Study Using ForwardPreliminary Study Using Forward Reaction Control System JetsReaction Control System Jets During Space Shuttle EntryDuring Space Shuttle Entry Carolina Restrepo Currently the shuttle uses only aft RCS jets for yaw control during entry Enough to handle present flight

Valasek, John

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.


461

Maximal Air Bubble Entrainment at Liquid-Drop Impact Wilco Bouwhuis, Roeland C. A. van der Veen, Tuan Tran, Diederik L. Keij, Koen G. Winkels, Ivo R. Peters,  

E-Print Network [OSTI]

Maximal Air Bubble Entrainment at Liquid-Drop Impact Wilco Bouwhuis, Roeland C. A. van der Veen the (relative) size of this entrained air bubble: for large drop impact velocity and large droplets, the inertia on a solid surface, an air bubble can be entrapped. Here, we show that two competing effects minimize

Snoeijer, Jacco

462

HYPERSONIC BUCKSHOT: ASTROPHYSICAL JETS AS HETEROGENEOUS COLLIMATED PLASMOIDS  

SciTech Connect (OSTI)

Herbig-Haro jets are commonly thought of as homogeneous beams of plasma traveling at hypersonic velocities. Structure within jet beams is often attributed to periodic or 'pulsed' variations of conditions at the jet source. Simulations based on this scenario result in knots extending across the jet diameter. Observations and recent high energy density laboratory experiments shed new light on structures below this scale and indicate they may be important for understanding the fundamentals of jet dynamics. In this paper, we offer an alternative to 'pulsed' models of protostellar jets. Using direct numerical simulations we explore the possibility that jets are chains of subradial clumps propagating through a moving interclump medium. Our models explore an idealization of this scenario by injecting small (r < r {sub jet}), dense ({rho}>{rho}{sub jet}) spheres embedded in an otherwise smooth interclump jet flow. The spheres are initialized with velocities differing from the jet velocity by {approx}15%. We find that the consequences of shifting from homogeneous to heterogeneous flows are significant as clumps interact with each other and with the interclump medium in a variety of ways. Structures which mimic what is expected from pulsed-jet models can form, as can be previously unseen, 'subradial' behaviors including backward facing bow shocks and off-axis working surfaces. While these small-scale structures have not been seen before in simulation studies, they are found in high-resolution jet observations. We discuss implications of our simulations for the interpretation of protostellar jets with regard to characterization of knots by a 'lifetime' or 'velocity history' approach as well as linking observed structures with central engines which produce the jets.

Yirak, Kristopher; Frank, Adam; Cunningham, Andrew J. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14620 (United States); Mitran, Sorin [Department of Mathematics, Applied Mathematics Program, University of North Carolina, Chapel Hill, NC 27599 (United States)], E-mail: yirak@pas.rochester.edu

2009-04-20T23:59:59.000Z

463

Fast Reactor Fuel Type and Reactor Safety Performance  

SciTech Connect (OSTI)

Fast Reactor Fuel Type and Reactor Safety Performance R. Wigeland , Idaho National Laboratory J. Cahalan, Argonne National Laboratory The sodium-cooled fast neutron reactor is currently being evaluated for the efficient transmutation of the highly-hazardous, long-lived, transuranic elements that are present in spent nuclear fuel. One of the fundamental choices that will be made is the selection of the fuel type for the fast reactor, whether oxide, metal, carbide, nitride, etc. It is likely that a decision on the fuel type will need to be made before many of the related technologies and facilities can be selected, from fuel fabrication to spent fuel reprocessing. A decision on fuel type should consider all impacts on the fast reactor system, including safety. Past work has demonstrated that the choice of fuel type may have a significant impact on the severity of consequences arising from accidents, especially for severe accidents of low probability. In this paper, the response of sodium-cooled fast reactors is discussed for both oxide and metal fuel types, highlighting the similarities and differences in reactor response and accident consequences. Any fast reactor facility must be designed to be able to successfully prevent, mitigate, or accommodate all consequences of potential events, including accidents. This is typically accomplished by using multiple barriers to the release of radiation, including the cladding on the fuel, the intact primary cooling system, and most visibly the reactor containment building. More recently, this has also included the use of ‘inherent safety’ concepts to reduce or eliminate the potential for serious damage in some cases. Past experience with oxide and metal fuel has demonstrated that both fuel types are suitable for use as fuel in a sodium-cooled fast reactor. However, safety analyses for these two fuel types have also shown that there can be substantial differences in accident consequences due to the neutronic and thermophysical properties of the fuel and their compatibility with the reactor coolant, with corresponding differences in the challenges presented to the reactor developers. Accident phenomena are discussed for the sodium-cooled fast reactor based on the mechanistic progression of conditions from accident initiation to accident termination, whether a benign state is achieved or more severe consequences are expected. General principles connecting accident phenomena and fuel properties are developed from the oxide and metal fuel safety analyses, providing guidelines that can be used as part of the evaluation for selection of fuel type for the sodium-cooled fast reactor.

R. Wigeland; J. Cahalan

2009-09-01T23:59:59.000Z

464

Jet Vetoes Interfering with H->WW  

E-Print Network [OSTI]

Far off-shell Higgs production in $H \\rightarrow WW,ZZ$, is a particularly powerful probe of Higgs properties, allowing one to disentangle Higgs width and coupling information unavailable in on-shell rate measurements. These measurements require an understanding of the cross section in the far off-shell region in the presence of realistic experimental cuts. We analytically study the effect of a $p_T$ jet veto on far off-shell cross sections, including signal-background interference, by utilizing hard functions in the soft collinear effective theory that are differential in the decay products of the $W/Z$. Summing large logarithms of $\\sqrt{\\hat s}/p_T^{veto}$, we find that the jet veto induces a strong dependence on the partonic centre of mass energy, $\\sqrt{\\hat s}$, and modifies distributions in $\\sqrt{\\hat s}$ or $M_T$. The example of $gg\\rightarrow H \\rightarrow WW$ is used to demonstrate these effects at next to leading log order. We also discuss the importance of jet vetoes and jet binning for the recent program to extract Higgs couplings and widths from far off-shell cross sections.

Ian Moult; Iain W. Stewart

2014-09-08T23:59:59.000Z

465

The Rapidity Dependence of Jet Quenching  

E-Print Network [OSTI]

The suppression of high transverse momentum (P_T) jets and hadrons in ultrarelativistic heavy-ion collisions with respect to a p-p baseline in terms of the nuclear suppression factor R_AA is one of the key observables to gauge the density of a hot and dense QCD medium. However, the suppression measured by R_AA is not a straightforward measure of the medium properties, the value of the observable also depends on the ratio of quark to gluon jets and on the slope of the hard parton spectrum, which explains why R_AA is found to be fairly similar at RHIC and LHC despite the very different dynamics. Measuring high P_T jets and hadrons at forward rapidity offers the same possibility of varying medium density, parton mixture and spectral slope without the need to compare across different sqrt(s) and experiments. In this work, the well-tested jet quenching Monte-Carlo (MC) framework YaJEM is utilized to compute the rapidity dependence of R_AA for three test cases.

Thorsten Renk

2014-06-26T23:59:59.000Z

466

The interaction between two radial jets  

E-Print Network [OSTI]

on an impingement surface with high surface heat and mass transfer. The objective of this study was to characterize the flow, surface pressure, and heat transfer for two radial jets as a function of nozzle geometry, in order to be able to design arrays of radial...

Gruber, Thomas Clifton

2012-06-07T23:59:59.000Z

467

Models comparison for JET polarimeter data  

SciTech Connect (OSTI)

A complete comparison between the theory and the measurements in polarimetry was done by using the Far Infrared Polarimeter at JET. More than 300 shots were analyzed, including a wide spectrum of JET scenarios in all critical conditions for polarimetry: high density, high and very low fields, high temperatures.This work is aimed at the demonstration of the robustness of the theoretical models for the JET polarimeter measurements in the perspective of using these models for ITER like plasma scenarios . In this context, an assessment was performed on how the line-integrated plasma density along the central vertical chord of FIR polarimeter could be evaluated using the Cotton-Mouton effect and its possible concrete use to correct fringe jumps of the interferometer.The models considered are: i) the rigorous numerical solution of the Stokes propagation equations, using dielectric tensor evaluated from JET equilibrium and Thomson scattering [1,2]; ii) two types of approximated solutions [2,3] and iii) the Guenther empirical model [4] that considers the mutual effect between Cotton-Mouton and Faraday rotation angle. The model calculations have been compared with polarimeter measurements for the Cotton-Mouton phase shift.The agreement with theory is satisfactory within the limits of experimental errors [3].

Mazzotta, C.; Orsitto, F. P.; Giovannozzi, E. [Centro Ricerche Energia Frascati, Euratom-ENEA Association, Frascati (Italy); Boboc, A.; Tudisco, O.; Zabeo, L. [Association EURATOM-UKAEA Culham Science Centre Abingdon 0X14 3DB (UK) (United Kingdom); Brombin, M.; Murari, A. [Consorzio RFX, Euratom-ENEA Association, Padova (Italy)

2008-03-12T23:59:59.000Z

468

HOT ELECTROMAGNETIC OUTFLOWS. II. JET BREAKOUT  

SciTech Connect (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

469

Gaseous reactor control system  

SciTech Connect (OSTI)

This paper describes a nuclear reactor control system for controlling the reactivity of the core of a nuclear reactor. It includes a control gas having a high neutron cross-section; a first tank containing a first supply of the control gas; a first conduit providing a first fluid passage extending into the core, the first conduit being operatively connected to communicate with the first tank; a first valve operatively connected to regulate the flow of the control gas between the first tank and the first conduit; a second conduit concentrically disposed around the first conduit such that a second fluid passage is defined between the outer surface of the first conduit and the inner surface of the second conduit; a second tank containing a second supply of the control gas, the second tank being operatively connected to communicate with the second fluid passage; a second supply valve operatively connected to regulate the flow of the control gas between the second tank and the second fluid passage.

Abdel-Khalik, S.

1991-09-03T23:59:59.000Z

470

Overview of the US stellarator reactor study  

SciTech Connect (OSTI)

This study, which uses a cost-minimization code that incorporates the ARIES costing and reactor component models with a I-D energy transport calculation, shows that a torsatron reactor could be competitive with a tokamak reactor.

Lyon, J.F. [Oak Ridge National Lab., TN (United States); Gulec, K. [Univ. of Tennessee, Knoxville, TN (United States); Miller, R.L. [Los Alamos National Lab., NM (United States); El-Guebaly, L. [Univ. of Wisconsin, Madison, WI (United States)

1993-12-31T23:59:59.000Z

471

Dynamics, Structure, and Emission of Electron-Positron Jets  

E-Print Network [OSTI]

The theory of gamma-ray emission from e$^{\\pm}$ jets and the implications for jet formation, dynamics and structure are reviewed. In particular, possible carriers of the jet's thrust on small scales, the transition from electromagnetic to particle dominance in Poynting flux jets, formation of pair cascades, synchrotron emission by cascading pairs, and formation of shocks due to unsteadiness in the jet parameters are considered, with emphasis on the observational consequences. Some recent progress in modeling transient emission from blazars is also briefly discussed.

A. Levinson

1997-08-10T23:59:59.000Z

472

?Linear Gas Jet with Tailored Density Profile"  

SciTech Connect (OSTI)

Supersonic, highly collimated gas jets and gas-filled capillary discharge waveguides are two primary targets of choice for Laser Plasma Accelerators (LPA) . Present gas jets have lengths of only 2-4 mm at densities of 1-4E19 cm-3, sufficient for self trapping and electron acceleration to energies up to ~150 MeV. Capillary structures 3 cm long have been used to accelerate beams up to 1 GeV. Capillary discharges used in LPAs serve to guide the pump laser and optimize the energy gain. A wall-stabilized capillary discharge provides a transverse profile across the channel that helps guide the laser and combat diffraction. Gas injection via a fast nozzle at one end provides some longitudinal density control, to improve the coupling. Gas jets with uniform or controlled density profiles may be used to control electron bunch injection and are being integrated into capillary experiments to add tuning of density. The gas jet for electron injection has not yet been optimized. Our Ph-I results have provided the LPA community with an alternative path to realizing a 2-3GeV electron bunch using just a gas jet. For example, our slit/blade combination gives a 15-20mm long acceleration path with tunable density profile, serving as an alternative to a 20-mm long capillary discharge with gas injection at one end. In Ph-II, we will extend these results to longer nozzles, to see whether we can synthesize 30 or 40-mm long plasma channels for LPAs.

KRISHNAN, Mahadevan

2012-12-10T23:59:59.000Z

473

Reactor Cost Analysis Brian James  

E-Print Network [OSTI]

Reactor Cost Analysis Brian James Directed Technologies, Inc. 6-7 November 2007 This presentation specification & optimization · Capital cost estimation · Projected hydrogen $/kg #12;Directed Technologies, Inc/WGS Membrane Reactor OTM/ Water-Splitting ANL With WGS #12;Directed Technologies, Inc. 6-7 November 2007 BILIWG

474

Solvent refined coal reactor quench system  

DOE Patents [OSTI]

There is described an improved SRC reactor quench system using a condensed product which is recycled to the reactor and provides cooling by evaporation. In the process, the second and subsequent reactors of a series of reactors are cooled by the addition of a light oil fraction which provides cooling by evaporation in the reactor. The vaporized quench liquid is recondensed from the reactor outlet vapor stream.

Thorogood, Robert M. (Macungie, PA)

1983-01-01T23:59:59.000Z

475

Solvent refined coal reactor quench system  

DOE Patents [OSTI]

There is described an improved SRC reactor quench system using a condensed product which is recycled to the reactor and provides cooling by evaporation. In the process, the second and subsequent reactors of a series of reactors are cooled by the addition of a light oil fraction which provides cooling by evaporation in the reactor. The vaporized quench liquid is recondensed from the reactor outlet vapor stream. 1 fig.

Thorogood, R.M.

1983-11-08T23:59:59.000Z

476

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

SciTech Connect (OSTI)

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

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

1995-07-01T23:59:59.000Z

477

Bubbly Flow Experiment in Channel Using an Optical Probe and Tracking Algorithm  

E-Print Network [OSTI]

was inserted through a porous media at three superficial gas velocities: 4.6 mm/s, 2.5 mm/s, and 1.4 mm/s. Two techniques were applied in the experiment to measure the bubbly flow: an optical probe and an in-house developed tracking algorithm. Measurements...

Khan, Abdul

2012-10-19T23:59:59.000Z

478

Methods for Investigating Gas Bubble Formation in Uranium-Zirconium Alloys  

E-Print Network [OSTI]

. 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...

Mews, Kathryn Ann Wright

2013-05-06T23:59:59.000Z

479

A mimetic finite difference method for the Stokes problem with elected edge bubbles  

SciTech Connect (OSTI)

A new mimetic finite difference method for the Stokes problem is proposed and analyzed. The unstable P{sub 1}-P{sub 0} discretization is stabilized by adding a small number of bubble functions to selected mesh edges. A simple strategy for selecting such edges is proposed and verified with numerical experiments. The discretizations schemes for Stokes and Navier-Stokes equations must satisfy the celebrated inf-sup (or the LBB) stability condition. The stability condition implies a balance between discrete spaces for velocity and pressure. In finite elements, this balance is frequently achieved by adding bubble functions to the velocity space. The goal of this article is to show that the stabilizing edge bubble functions can be added only to a small set of mesh edges. This results in a smaller algebraic system and potentially in a faster calculations. We employ the mimetic finite difference (MFD) discretization technique that works for general polyhedral meshes and can accomodate non-uniform distribution of stabilizing bubbles.

Lipnikov, K [Los Alamos National Laboratory; Berirao, L [DIPARTMENTO DI MATERMATICA

2009-01-01T23:59:59.000Z

480

Bubble dynamics and interactions with a pair of micro pillars in tandem D. Elcock a  

E-Print Network [OSTI]

Energy Efficiency and Industrial Technology, Idaho National Laboratory, Idaho Falls, ID 83415, USA a r the flow, heat transfer, and bubble dynamics in cross flow over bluff bodies is significantly different, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, NY 12180, United States b Department of Energy

Peles, Yoav

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.