Sample records for br jet bubbling

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

    E-Print Network [OSTI]

    Assaf Sternberg; Noam Soker

    2008-08-17T23:59:59.000Z

    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).

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

    E-Print Network [OSTI]

    Assaf Sternberg; Noam Soker

    2008-01-09T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Sternberg, Assaf

    2007-01-01T23:59:59.000Z

    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.

  4. A Study of Vertical Gas Jets in a Bubbling Fluidized Bed

    SciTech Connect (OSTI)

    Steven Ceccio; Jennifer Curtis

    2011-01-18T23:59:59.000Z

    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.

  5. Energy resolution of gamma-ray spectroscopy of JET plasmas with a LaBr{sub 3} scintillator detector and digital data acquisition

    SciTech Connect (OSTI)

    Nocente, M.; Tardocchi, M.; Grosso, G.; Perelli Cippo, E.; Pietropaolo, A.; Proverbio, I.; Gorini, G. [Dipartimento di Fisica, Universita degli Studi di Milano-Bicocca and Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, 20125 Milano (Italy); Chugunov, I.; Gin, D.; Shevelev, A. [A. F. Ioffe Physico-Technical Institute, St. Petersburg 194021 (Russian Federation); Pereira, R. C.; Fernandes, A. M.; Neto, A.; Sousa, J. [Associacao EURATOM/IST Centro de Fusao Nuclear, Instituto Superior Tecnico, 1049-001 Lisboa (Portugal); Edlington, T.; Kiptily, V.; Syme, B. [Culham Centre for Fusion Energy, Culham OX143DB (United Kingdom); Murari, A. [Consorzio RFX, 35127 Padova (Italy); Collaboration: JET-EFDA Contributors

    2010-10-15T23:59:59.000Z

    A new high efficiency, high resolution, fast {gamma}-ray spectrometer was recently installed at the JET tokamak. The spectrometer is based on a LaBr{sub 3}(Ce) scintillator coupled to a photomultiplier tube. A digital data acquisition system is used to allow spectrometry with event rates in excess of 1 MHz expected in future JET DT plasmas. However, at the lower rates typical of present day experiments, digitization can degrade the energy resolution of the system, depending on the algorithms used for extracting pulse height information from the digitized pulses. In this paper, the digital and analog spectrometry methods were compared for different experimental conditions. An algorithm based on pulse shape fitting was developed, providing energy resolution equivalent to the traditional analog spectrometry method.

  6. br Owner br Facility br Type br Capacity br MW br Commercial br Online

    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:FAQ < RAPID Jump to:SeadovCooperative JumpWilliamsonWoodsonCounty is aYoakumYuHangeZoloFacility br Type br

  7. Bubble diagnostics

    DOE Patents [OSTI]

    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

    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.

  8. Giant bubble pinch-off

    E-Print Network [OSTI]

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

    2006-01-24T23:59:59.000Z

    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.

  9. Rotating bubble membrane radiator

    DOE Patents [OSTI]

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

    1988-12-06T23:59:59.000Z

    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.

  10. The thermodynamics of bubbles

    E-Print Network [OSTI]

    Clark, John A.

    1956-01-01T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    S. Heinz; E. Churazov

    2005-09-26T23:59:59.000Z

    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.

  12. Quantum Subcritical Bubbles

    E-Print Network [OSTI]

    Tomoko Uesugi; Masahiro Morikawa; Tetsuya Shiromizu

    1996-06-26T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    McDonald, Kirk

    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

  14. Helium bubble bursting in tungsten

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Palanker, Daniel

    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

  16. Microfluidic Actuation Using Electrochemically Generated Bubbles

    E-Print Network [OSTI]

    Sachs, Frederick

    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

  17. A prediction for bubbling geometries

    E-Print Network [OSTI]

    Takuya Okuda

    2008-02-11T23:59:59.000Z

    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.

  18. Modeling air entrainment in plunging jet using 3DYNAFS

    E-Print Network [OSTI]

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

    2011-01-01T23:59:59.000Z

    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...

  19. Astrophysical Jets

    SciTech Connect (OSTI)

    Madejski, Grzegorz (SLAC) [SLAC

    2006-05-01T23:59:59.000Z

    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.

  20. Stellar jets

    E-Print Network [OSTI]

    Thomas J. Maccarone

    2008-05-23T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    McDonald, Kirk

    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

  2. Emerging Jets

    E-Print Network [OSTI]

    Pedro Schwaller; Daniel Stolarski; Andreas Weiler

    2015-02-24T23:59:59.000Z

    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.

  3. Emerging Jets

    E-Print Network [OSTI]

    Schwaller, Pedro; Weiler, Andreas

    2015-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    R. S. Sutherland; G. V. Bicknell

    2007-07-25T23:59:59.000Z

    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.

  5. Bubble formation in Rangely Field, Colorado

    E-Print Network [OSTI]

    Wood, J. W

    1953-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Lin, Liwei

    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

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

    E-Print Network [OSTI]

    Sutherland, R S

    2007-01-01T23:59:59.000Z

    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...

  8. ENGINEERING DEVELOPMENT OF SLURRY BUBBLE COLUMN REACTOR (SBCR) TECHNOLOGY

    SciTech Connect (OSTI)

    Bernard A. Toseland

    2000-12-31T23:59:59.000Z

    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.

  9. Bubble formation in reservoir fluids at low supersaturations

    E-Print Network [OSTI]

    Wieland, Denton R

    1956-01-01T23:59:59.000Z

    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...

  10. Bubble Universe Dynamics After Free Passage

    E-Print Network [OSTI]

    Pontus Ahlqvist; Kate Eckerle; Brian Greene

    2014-12-26T23:59:59.000Z

    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.

  11. Tiny Bubbles in my BEC

    SciTech Connect (OSTI)

    Blinova, Alina A. [Los Alamos National Laboratory

    2012-08-01T23:59:59.000Z

    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.

  12. Collapse of Kaluza-Klein Bubbles

    E-Print Network [OSTI]

    Steven Corley; Ted Jacobson

    1994-03-09T23:59:59.000Z

    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.

  13. Bremsstrahlung Radiation At a Vacuum Bubble Wall

    E-Print Network [OSTI]

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

    2007-04-06T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Straube, Arthur V.

    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

  15. Fluid mechanics of bubble capture by the diving bell spider

    E-Print Network [OSTI]

    Brooks, Alice (Alice P.)

    2010-01-01T23:59:59.000Z

    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 ...

  16. The incorporation of bubbles into a computer graphics fluid simulation

    E-Print Network [OSTI]

    Greenwood, Shannon Thomas

    2005-08-29T23:59:59.000Z

    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...

  17. A hot bubble at the centre of M81

    E-Print Network [OSTI]

    Ricci, T V; Giansante, L

    2015-01-01T23:59:59.000Z

    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...

  18. Inclusive Jets in PHP

    E-Print Network [OSTI]

    Roloff, Philipp

    2013-01-01T23:59:59.000Z

    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.

  19. Inclusive Jets in PHP

    E-Print Network [OSTI]

    Philipp Roloff

    2013-10-23T23:59:59.000Z

    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.

  20. Air entrainment by a plunging jet under intermittent vortex conditions

    E-Print Network [OSTI]

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

    2011-01-01T23:59:59.000Z

    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.

  1. 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...

  2. Oscillating plasma bubbles. II. Pulsed experiments

    SciTech Connect (OSTI)

    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

    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.

  3. Gas bubble dynamics in soft materials

    E-Print Network [OSTI]

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

    2014-10-14T23:59:59.000Z

    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.

  4. Microfluidics Formation of Bubbles in a Multisection Flow-Focusing

    E-Print Network [OSTI]

    Prentiss, Mara

    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

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

    SciTech Connect (OSTI)

    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

    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).

  6. REVIEW ARTIC LE MICROSCALE THERMAL BUBBLE FORMATION

    E-Print Network [OSTI]

    Lin, Liwei

    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

  7. Nucleate boiling bubble growth and departure

    E-Print Network [OSTI]

    Staniszewski, Bogumil E.

    1959-01-01T23:59:59.000Z

    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 ...

  8. Analytical Modeling of a Bubble Column Dehumidifier

    E-Print Network [OSTI]

    Tow, Emily W.

    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 ...

  9. aBubbleTree? Thomas H. Parker

    E-Print Network [OSTI]

    Parker, Thomas H.

    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

  10. Jets at all scales

    E-Print Network [OSTI]

    F. Tavecchio

    2002-12-11T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Orthel, John L.

    2010-01-01T23:59:59.000Z

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

  12. Microquasars and Jets

    E-Print Network [OSTI]

    Sylvain Chaty

    2005-06-01T23:59:59.000Z

    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.

  13. High energy XeBr electric discharge laser

    DOE Patents [OSTI]

    Sze, Robert C. (Santa Fe, NM); Scott, Peter B. (Los Alamos, NM)

    1981-01-01T23:59:59.000Z

    A high energy XeBr laser for producing coherent radiation at 282 nm. The XeBr laser utilizes an electric discharge as the excitation source to minimize formation of molecular ions thereby minimizing absorption of laser radiation by the active medium. Additionally, HBr is used as the halogen donor which undergoes harpooning reactions with Xe.sub.M * to form XeBr*.

  14. On the (im)possibility of warp bubbles

    E-Print Network [OSTI]

    Chris Van Den Broeck

    2000-05-18T23:59:59.000Z

    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.

  15. On acoustic cavitation of slightly subcritical bubbles Anthony Harkin

    E-Print Network [OSTI]

    Kaper, Tasso J.

    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

  16. Bubble Coalescence DOI: 10.1002/anie.201006552

    E-Print Network [OSTI]

    Chan, Derek Y C

    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

  17. Bubble visualization in a simulated hydraulic jump

    E-Print Network [OSTI]

    Witt, Adam; Shen, Lian

    2013-01-01T23:59:59.000Z

    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.

  18. Engineering development of a bubble tray structure

    E-Print Network [OSTI]

    Glitsch, Hans C

    1954-01-01T23:59:59.000Z

    ~ ~ ~ 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...

  19. Hotspots, Jets and Environments

    E-Print Network [OSTI]

    M. J. Hardcastle

    2007-07-12T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Furukawa, Toru

    2002-01-01T23:59:59.000Z

    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...

  1. Heart-shaped bubbles rising in anisotropic liquids Chunfeng Zhou

    E-Print Network [OSTI]

    Feng, James J.

    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

  2. Learning Overcomplete Spatiotemporal Bubbles from Natural Image Sequences

    E-Print Network [OSTI]

    Zhang, Liqing

    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

  3. Do subcritical bubbles hinder first order phase transition?

    E-Print Network [OSTI]

    K. Enqvist; A. Riotto; I. Vilja

    1995-05-19T23:59:59.000Z

    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.

  4. Maximal air bubble entrainment at liquid drop impact

    E-Print Network [OSTI]

    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

    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.

  5. J_{E_T}: A Global Jet Finding Algorithm

    E-Print Network [OSTI]

    Yang Bai; Zhenyu Han; Ran Lu

    2014-11-13T23:59:59.000Z

    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.

  6. Bubbling the Newly Grown Black Ring Hair

    E-Print Network [OSTI]

    Orestis Vasilakis

    2012-02-08T23:59:59.000Z

    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.

  7. Angular Scaling In Jets

    SciTech Connect (OSTI)

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

    2012-02-17T23:59:59.000Z

    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.

  8. ATLAS Jet Energy Scale

    E-Print Network [OSTI]

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

    2012-01-11T23:59:59.000Z

    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.

  9. Bubble Radiation Detection: Current and Future Capability

    SciTech Connect (OSTI)

    AJ Peurrung; RA Craig

    1999-11-15T23:59:59.000Z

    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.

  10. Compton profile study of polycrystalline ZnBr{sub 2}

    SciTech Connect (OSTI)

    Dhaka, M. S. [Department of Physics, Engineering College Bikaner, Bikaner, 334004, Rajasthan (India); Sharma, G. [Department of Physics, Bansthali University, Bansthali, 304022, Rajasthan (India); Mishra, M. C.; Kothari, R. K.; Sharma, B. K. [Department of Physics, University of Rajasthan, Jaipur, 302004, Rajasthan (India)

    2010-12-01T23:59:59.000Z

    The first ever Compton profile study of polycrystalline ZnBr{sub 2} is presented in this paper. The measurement of polycrystalline sample of ZnBr{sub 2} is performed using 59.54 keV gamma-rays emanating from an {sup 241}Am radioisotope. Theoretical calculations are performed following the Ionic model calculations for a number of configurations Zn{sup +x}Br{sub 2}{sup -x/2}(0.0{<=}x{<=}2.0 in step of 0.5) utilizing free atom profiles. The ionic model suggest transfer of 2.0 electrons from 4 s state of Zn to 4 p state of two Br atoms. The autocorrelation function B(z) is also derived from experiment and the most favoured ionic valence Compton profiles.

  11. Ca2+-Doped CeBr3 Scintillating Materials

    SciTech Connect (OSTI)

    Guss, Paul [NSTec; Foster, Michael E. [SNL; Wong, Bryan M. [SNL; Doty, F. Patrick [SNL; Shah, Kanai [RMD; Squillante, Michael R. [RMD; Shirwadkar, Urmila [RMD; Hawrami, Rastgo [RMD; Tower, Josh [RMD; Yuan, Ding [NSTec

    2014-01-01T23:59:59.000Z

    Despite the outstanding scintillation performance characteristics of cerium tribromide (CeBr3) and cerium-activated lanthanum tribromide, their commercial availability and application are limited due to the difficulties of growing large, crack-free single crystals from these fragile materials. This investigation employed aliovalent doping to increase crystal strength while maintaining the optical properties of the crystal. One divalent dopant (Ca2+) was used as a dopant to strengthen CeBr3 without negatively impacting scintillation performance. Ingots containing nominal concentrations of 1.9% of the Ca2+ dopant were grown. Preliminary scintillation measurements are presented for this aliovalently doped scintillator. Ca2+-doped CeBr3 exhibited little or no change in the peak fluorescence emission for 371 nm optical excitation for CeBr3. The structural, electronic, and optical properties of CeBr3 crystals were studied using the density functional theory within the generalized gradient approximation. The calculated lattice parameters are in good agreement with the experimental data. The energy band structures and density of states were obtained. The optical properties of CeBr3, including the dielectric function, were calculated.

  12. Deformed bubble growth and coalescence in polymer foam processing

    E-Print Network [OSTI]

    Allaboun, Hussein Raji

    1996-01-01T23:59:59.000Z

    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...

  13. Bubble coalescence dynamics and supersaturation in electrolytic gas evolution

    SciTech Connect (OSTI)

    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

    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.

  14. The hydrogen bubble chamber and the strange resonances

    SciTech Connect (OSTI)

    Alvarez, L.W.

    1985-06-01T23:59:59.000Z

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

  15. 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,...

  16. Thermonuclear Supernovae: Is Deflagration Triggered by Floating Bubbles?

    E-Print Network [OSTI]

    Eduardo Bravo; Domingo Garcia-Senz

    2002-11-13T23:59:59.000Z

    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).

  17. Detecting vapour bubbles in simulations of metastable water

    SciTech Connect (OSTI)

    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

    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.

  18. COLD BUBBLE FORMATION DURING TOKAMAK DENSITY LIMIT DISRUPTIONS

    E-Print Network [OSTI]

    Howard, John

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

  19. Numerical Simulation of Bubble Formation in Co-Flowing Mercury

    SciTech Connect (OSTI)

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

    2008-01-01T23:59:59.000Z

    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.

  20. 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...

  1. 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...

  2. 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...

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

    E-Print Network [OSTI]

    Harkin, Anthony

    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

  4. Matrix isolation and computational study of isodifluorodibromomethane (F{sub 2}CBr-Br): A route to Br{sub 2} formation in CF{sub 2}Br{sub 2} photolysis

    SciTech Connect (OSTI)

    George, Lisa; Kalume, Aimable; Reid, Scott A. [Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201-1881 (United States); El-Khoury, Patrick Z.; Tarnovsky, Alexander [Department of Chemistry and Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403 (United States)

    2010-02-28T23:59:59.000Z

    The photolysis products of dibromodifluoromethane (CF{sub 2}Br{sub 2}) were characterized by matrix isolation infrared and UV/Visible spectroscopy, supported by ab initio calculations. Photolysis at wavelengths of 240 and 266 nm of CF{sub 2}Br{sub 2}:Ar samples ({approx}1:5000) held at {approx}5 K yielded iso-CF{sub 2}Br{sub 2} (F{sub 2}CBrBr), a weakly bound isomer of CF{sub 2}Br{sub 2}, which is characterized here for the first time. The observed infrared and UV/Visible absorptions of iso-CF{sub 2}Br{sub 2} are in excellent agreement with computational predictions at the B3LYP/aug-cc-pVTZ level. Single point energy calculations at the CCSD(T)/aug-cc-pVDZ level on the B3LYP optimized geometries suggest that the isoform is a minimum on the CF{sub 2}Br{sub 2} potential energy surface, lying some 55 kcal/mol above the CF{sub 2}Br{sub 2} ground state. The energies of various stationary points on the CF{sub 2}Br{sub 2} potential energy surface were characterized computationally; taken with our experimental results, these show that iso-CF{sub 2}Br{sub 2} is an intermediate in the Br+CF{sub 2}Br{yields}CF{sub 2}+Br{sub 2} reaction. The photochemistry of the isoform was also investigated; excitation into the intense 359 nm absorption band resulted in isomerization to CF{sub 2}Br{sub 2}. Our results are discussed in view of the rich literature on the gas-phase photochemistry of CF{sub 2}Br{sub 2}, particularly with respect to the existence of a roaming atom pathway leading to molecular products.

  5. Asymmetric bubble disconnection: persistent vibration evolves into smooth contact

    E-Print Network [OSTI]

    Zhang, Wendy

    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

  6. Experimental setup for the investigation of bubble mediated gas exchange

    E-Print Network [OSTI]

    Jaehne, Bernd

    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

  7. Gas Bubble Formation in Stagnant and Flowing Mercury

    SciTech Connect (OSTI)

    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

    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.

  8. Multiple jet interactions

    E-Print Network [OSTI]

    Hehr, Roger James

    2012-06-07T23:59:59.000Z

    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...

  9. Jet Substructure by Accident

    E-Print Network [OSTI]

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

    2013-04-23T23:59:59.000Z

    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.

  10. Jet Substructure by Accident

    E-Print Network [OSTI]

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

    2012-01-01T23:59:59.000Z

    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.

  11. Organic vapor jet printing system

    DOE Patents [OSTI]

    Forrest, Stephen R

    2012-10-23T23:59:59.000Z

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

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

    E-Print Network [OSTI]

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

    2007-09-26T23:59:59.000Z

    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).

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

    SciTech Connect (OSTI)

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

    2010-09-01T23:59:59.000Z

    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.

  14. Gasoline Jet Fuels

    E-Print Network [OSTI]

    Kemner, Ken

    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

  15. Vortex diode jet

    DOE Patents [OSTI]

    Houck, Edward D. (Idaho Falls, ID)

    1994-01-01T23:59:59.000Z

    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.

  16. Jet quenching and elliptic flow

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2007-08-29T23:59:59.000Z

    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.

  17. Rapidity-Dependent Jet Vetoes

    E-Print Network [OSTI]

    Shireen Gangal; Maximilian Stahlhofen; Frank J. Tackmann

    2014-12-15T23:59:59.000Z

    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.

  18. Inertial confinement fusion based on the ion-bubble trigger

    SciTech Connect (OSTI)

    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

    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.

  19. Bubble Chambers for Experiments in Nuclear Astrophysics

    E-Print Network [OSTI]

    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

    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...

  20. Delayed neutron energy spectra of {sup 87}Br, {sup 88}Br, {sup 89}Br, {sup 90}Br, {sup 137}I, {sup 138}I, {sup 139}I, and {sup 186}Te

    SciTech Connect (OSTI)

    Greenwood, R.C.; Watts, K.D. [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States). Idaho National Engineering Lab.

    1997-07-01T23:59:59.000Z

    In prior publications, the authors reported measurements of the energy spectra of delayed neutrons for the isotope-separated fission product precursors {sup 93}Rb, {sup 94}Rb, {sup 95}Rb, {sup 96}Rb, {sup 97}Rb, {sup 143}Cs, {sup 144}Cs, and {sup 145}Cs. Such studies of delayed neutron energy spectra have important applications in reactor physics, primarily relating to the fundamental role played by delayed neutrons in the kinetic behavior of nuclear reactors. Measurement of the energy spectra of delayed neutrons for the isotope-separated, fission product precursors {sup 87}Br, {sup 88}Br, {sup 89}Br, {sup 90}Br, {sup 137}I, {sup 138}I, {sup 139}I, and {sup 136}Te are reported for an energy range up to 1,213 keV and with lower cutoff energies of 11.1, 11.1, 29.9, 48.9, 14.2, 23.3, 29.9, and 48.9 keV, respectively. These data were obtained at the TRISTAN Isotope Separation On-Line facility using H{sub 2} and CH{sub 4} gas-filled proportional counters. The data for each of the bromine, iodine, and tellurium isotopes show good qualitative agreement with the published {sup 3}He ionization chamber data at energies above {approximately}200 keV. In addition, they provide definitive spectral information down to their respective cut-off energies.

  1. Refractive indexes of aqueous LiBr solutions

    SciTech Connect (OSTI)

    Zaltash, A.; Ally, M.R. (Energy Div., Oak Ridge National Lab., Oak Ridge, TN (US))

    1992-01-01T23:59:59.000Z

    This paper reports that the refractive indexes of water-lithium bromide solutions were measured in the temperature range from 5.0 to 80.0 {degrees}C and in the range of salt concentrations from 0.00 (deionized water) to 58.90 mass %. An electrolyte solution of LlBr in water was chosen for study because of its wide use as an absorption chiller fluid. The concentration of LlBr aqueous solution was determined by argentimetric titration using tetrabromofluoresceln (Eosin) as an adsorption indicator and was checked at a few discrete concentrations (10.06, 20.30, and 58.90 mass % LlBr) against the values obtained by gravimetric analysis. The deviation between values obtained using these two techniques was found to be less than 0.27 mass %. The refractive indexes are shown to represent a reliable and convenient way of measuring the concentration of salt (or water) in LlBr solutions with accuracies of {plus minus}0.3 mass % salt.

  2. Measurements of Gas Bubble Size Distributions in Flowing Liquid Mercury

    SciTech Connect (OSTI)

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

    2012-01-01T23:59:59.000Z

    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.

  3. Interfacial characteristic measurements in horizontal bubbly two- phase flow

    SciTech Connect (OSTI)

    Wang, Z.; Kocamustafaogullari, G.

    1990-10-01T23:59:59.000Z

    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.

  4. Interfacial characteristic measurements in horizontal bubbly two-phase flow

    SciTech Connect (OSTI)

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

    1990-10-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Daripa, Prabir

    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

  6. Dynamics of Subcritical Bubbles in First Order Phase Transition

    E-Print Network [OSTI]

    Tetsuya Shiromizu; Masahiro Morikawa; Jun'ichi Yokoyama

    1995-09-05T23:59:59.000Z

    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.

  7. SUBCRITICAL BUBBLES NEAR THE PHASE SPACE DOMAIN WALL

    E-Print Network [OSTI]

    J. Sirkka; I. Vilja

    1995-03-31T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

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

    2014-01-01T23:59:59.000Z

    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...

  9. Modified shielding jet model for twin-jet shielding analysis

    E-Print Network [OSTI]

    Gilbride, Jennifer Frances

    2012-06-07T23:59:59.000Z

    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...

  10. The transition from two phase bubble flow to slug flow

    E-Print Network [OSTI]

    Radovcich, Nick A.

    1962-01-01T23:59:59.000Z

    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 ...

  11. Steam bubble collapse, water hammer and piping network response

    E-Print Network [OSTI]

    Gruel, R.

    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 ...

  12. Quantum Decoherence of Subcritical Bubble in Electroweak Phase Transition

    E-Print Network [OSTI]

    Tetsuya Shiromizu

    1995-12-14T23:59:59.000Z

    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.

  13. Longpath DOAS observations of surface BrO at Summit, Greenland

    E-Print Network [OSTI]

    2011-01-01T23:59:59.000Z

    surface BrO at Summit, Greenland J. Stutz 1 , J. L. Thomasimpact of BrO at Summit, Greenland in 2007 and 2008, Atmos.of peroxy radicals at Summit, Greenland during summer 2003,

  14. Comparison of CsBr and KBr coated Cu photocathodes: Effects of...

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

    Comparison of CsBr and KBr coated Cu photocathodes: Effects of laser irradiation and work function changes. Abstract: Thin films (7 nm layers) of CsBr and KBr were deposited...

  15. Guide to Developing Air-Cooled Lithium Bromide (LiBr) Absorption...

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

    Guide to Developing Air-Cooled Lithium Bromide (LiBr) Absorption for CHP Applications, April 2005 Guide to Developing Air-Cooled Lithium Bromide (LiBr) Absorption for CHP...

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

    E-Print Network [OSTI]

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

    2007-01-01T23:59:59.000Z

    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...

  17. Jet initiation of PBX 9502

    SciTech Connect (OSTI)

    McAfee, J.M.

    1987-07-01T23:59:59.000Z

    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.

  18. The decay of a new nuclide /sup 71/Br

    E-Print Network [OSTI]

    Hagberg, E; Evans, H C; Hardy, J C; Koslowsky, V T; Schmeing, H; Schrewe, U J; Sharma, K S

    1981-01-01T23:59:59.000Z

    The decay of mass-separated samples of the previously unknown nuclide /sup 71/Br have been investigated by means of the Chalk River on-line isotope separator. Eleven gamma -transitions were assigned to the decay of this nuclide and its half-life was measured to be 21.4+or-0.6 s. A simple decay scheme for /sup 71/Br has been constructed incorporating six levels in its daughter, /sup 71/Se. The half-life of the first excited state in /sup 71/Se was measured to be 5.5+or-1.0 mu s and the transition from this state to the ground state was found to be highly converted. Systematic trends in the level schemes of /sup 67 /Zn, /sup 69/Ge and /sup 71/Se are investigated. (16 refs).

  19. Buoyant jet behavior in confined regions

    E-Print Network [OSTI]

    Fry, David J.

    1981-01-01T23:59:59.000Z

    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 ...

  20. Comparison of CeBr3 with LaBr3:Ce, LaCl3:Ce, and NaI:Tl Detectors

    SciTech Connect (OSTI)

    ,

    2010-09-01T23:59:59.000Z

    Energy resolution and detection efficiency were compared between two sizes of cerium bromide (CeBr3) scintillators, three sizes of lanthanum bromide (LaBr3:Ce) scintillators, three sizes of sodium iodide (NaI:Tl) scintillators, and a lanthanum chloride (LaCl3:Ce) scintillator. Comparisons are made of key parameters such as energy resolution, detection efficiency, linearity, and self-activity of CeBr3, LaBr3:Ce, LaCl3:Ce, and NaI:Tl scintillator detectors. The scintillator detectors are tested by comparing the peak separation and identification in the energy range up to 3.0 MeV using 133Ba, 152Eu, and naturally occurring radioactive materials [1]. The study has shown that CeBr3 scintillator detectors provided by Saint-Gobain offer better resolution than NaI:Tl scintillator detectors. CeBr3 detectors could resolve some closely spaced peaks from 133Ba and 152Eu, which NaI:Tl could not. LaBr3:Ce has slightly better resolution, and a slightly higher efficiency than CeBr3. In this work, “self-activity” of each of these four detector types was measured by operating the detectors themselves. A comparison of the intrinsic activity for all of the detectors in this study is demonstrated. For CeBr3, the self-activity present may be reduced, or even eliminated in the future, through improved processes for growing the material. It will be discussed if, and under what conditions, CeBr3 may be better than LaBr3:Ce and LaCl3:Ce for detection of certain special nuclear material ?-rays [2]. An overall advantage of CeBr3 detectors over lanthanum halide and NaI:Tl detectors will be discussed.

  1. Shocks and Wind Bubbles Around Energetic Pulsars

    E-Print Network [OSTI]

    Bryan M. Gaensler

    2004-05-14T23:59:59.000Z

    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.

  2. Bubble masks for time-encoded imaging of fast neutrons.

    SciTech Connect (OSTI)

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

    2013-09-01T23:59:59.000Z

    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.

  3. Mercury Jet Studies Tristan Davenne

    E-Print Network [OSTI]

    McDonald, Kirk

    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

  4. OPENING ANGLES OF COLLAPSAR JETS

    SciTech Connect (OSTI)

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

    2013-11-10T23:59:59.000Z

    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.

  5. Electrical breakdown of a bubble in a water-filled capillary

    SciTech Connect (OSTI)

    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

    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.

  6. Plectoneme tip bubbles: Coupled denaturation and writhing in supercoiled DNA

    E-Print Network [OSTI]

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

    2014-04-10T23:59:59.000Z

    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.

  7. Oscillating plasma bubbles. III. Internal electron sources and sinks

    SciTech Connect (OSTI)

    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

    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.

  8. Exploring GLIMPSE Bubble N107: Multiwavelength Observations and Simulations

    E-Print Network [OSTI]

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

    2014-01-01T23:59:59.000Z

    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...

  9. Impact of boundaries on velocity profiles in bubble rafts

    E-Print Network [OSTI]

    Yuhong Wang; Kapilanjan Krishan; Michael Dennin

    2006-01-31T23:59:59.000Z

    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.

  10. Natural Organobromine in Marine Sediments: New Evidence of Biogeochemical Br Cycling

    SciTech Connect (OSTI)

    A Leri; J Hakala; M Marcus; A Lanzirotti; C Reddy; S Myneni

    2011-12-31T23:59:59.000Z

    Organobromine (Br{sub org}) compounds, commonly recognized as persistent, toxic anthropogenic pollutants, are also produced naturally in terrestrial and marine systems. Several enzymatic and abiotic bromination mechanisms have been identified, as well as an array of natural Br{sub org} molecules associated with various marine organisms. The fate of the carbon-bromine functionality in the marine environment, however, remains largely unexplored. Oceanographic studies have noted an association between bromine (Br) and organic carbon (C{sub org}) in marine sediments. Even so, there has been no direct chemical evidence that Br in the sediments exists in a stable form apart from inorganic bromide (Br{sub inorg}), which is widely presumed conservative in marine systems. To investigate the scope of natural Br{sub org} production and its fate in the environment, we probed Br distribution and speciation in estuarine and marine sediments using in situ X-ray spectroscopy and spectromicroscopy. We show that Br{sub org} is ubiquitous throughout diverse sedimentary environments, occurring in correlation with C{sub org} and metals such as Fe, Ca, and Zn. Analysis of sinking particulate carbon from the seawater column links the Br{sub org} observed in sediments to biologically produced Br{sub org} compounds that persist through humification of natural organic matter (NOM). Br speciation varies with sediment depth, revealing biogeochemical cycling of Br between organic and inorganic forms as part of the burial and degradation of NOM. These findings illuminate the chemistry behind the association of Br with Corg in marine sediments and cast doubt on the paradigmatic classification of Br as a conservative element in seawater systems.

  11. Lifetimes of N = Z Nuclei As-66 and Br-70

    E-Print Network [OSTI]

    Burch, R. H.; Gagliardi, Carl A.; Tribble, Robert E.

    1988-01-01T23:59:59.000Z

    coupling constant Gz of nuclear beta decay to the Fermi coupling constant Gz determined from muon decay, after correcting Gz for "inner" radia- tive effects' that depend upon the assumed substructure of the nucleon. An accurate determination of U... measured. As a first step in an effort to extend our knowledge of superallowed Fermi decays to higher Z systems, we have remeasured the half lives of As and Br, using a detection system that is subject to different systematic efFects from those...

  12. ENGINEERING DEVELOPMENT OF SLURRY BUBBLE COLUMN REACTOR (SBCR) TECHNOLOGY

    SciTech Connect (OSTI)

    Bernard A. Toseland, Ph.D.

    1999-03-01T23:59:59.000Z

    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.

  13. The Formation of a Bubble from a Submerged Orifice

    E-Print Network [OSTI]

    Simmons, Jonathan A; Shikhmurzaev, Yulii D

    2015-01-01T23:59:59.000Z

    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.

  14. Electron bubbles in liquid helium: infrared-absorption spectrum

    E-Print Network [OSTI]

    Víctor Grau; Manuel Barranco; Ricardo Mayol; Martí Pi

    2006-01-20T23:59:59.000Z

    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.

  15. Radiative Decay of Bubble Oscillations in a Compressible Fluid

    E-Print Network [OSTI]

    A. M. Shapiro; M. I. Weinstein

    2011-01-01T23:59:59.000Z

    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.

  16. Dark matter limits froma 15 kg windowless bubble chamber

    SciTech Connect (OSTI)

    Szydagis, Matthew Mark; /Chicago U.

    2010-12-01T23:59:59.000Z

    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.

  17. 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...

  18. Heat and mass transfer in bubble column dehumidifiers for HDH desalination

    E-Print Network [OSTI]

    Tow, Emily W

    2014-01-01T23:59:59.000Z

    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 ...

  19. Some hydrodynamic characteristics of bubbly mixtures flowing vertically upward in tubes

    E-Print Network [OSTI]

    Rose, Sewell C.

    1964-01-01T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    Deymier, Pierre

    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

  1. Micromachined chemical jet dispenser

    DOE Patents [OSTI]

    Swierkowski, S.P.

    1999-03-02T23:59:59.000Z

    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.

  2. Micromachined chemical jet dispenser

    DOE Patents [OSTI]

    Swierkowski, Steve P. (Livermore, CA)

    1999-03-02T23:59:59.000Z

    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.

  3. Water cooled steam jet

    DOE Patents [OSTI]

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

    1999-01-01T23:59:59.000Z

    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.

  4. Jets in heavy ion collisions with ATLAS

    E-Print Network [OSTI]

    Martin Spousta; for the ATLAS Collaboration

    2012-11-14T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Yuan, Li

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

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

    SciTech Connect (OSTI)

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

    2014-07-10T23:59:59.000Z

    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

  7. How to calibrate the jet energy scale?

    SciTech Connect (OSTI)

    Hatakeyama, K.; /Rockefeller U.

    2006-01-01T23:59:59.000Z

    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.

  8. A theory for radial jet reattachment flow

    E-Print Network [OSTI]

    Hadden, Lynne Loise

    2012-06-07T23:59:59.000Z

    , 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...

  9. Latest jet results from the Tevatron

    SciTech Connect (OSTI)

    Price, Darren D.

    2010-05-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Lu, Tiao

    ] 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

  11. 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

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

    E-Print Network [OSTI]

    Ohl, Claus-Dieter

    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

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

    E-Print Network [OSTI]

    Suslick, Kenneth S.

    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

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

    E-Print Network [OSTI]

    Ghoniem, Nasr M.

    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

  15. Radial flow pulse jet mixer

    DOE Patents [OSTI]

    VanOsdol, John G.

    2013-06-25T23:59:59.000Z

    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.

  16. Strategic Technology JET PROPULSION LABORATORY

    E-Print Network [OSTI]

    Waliser, Duane E.

    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

  17. Numerical Simulations of Bouncing Jets

    E-Print Network [OSTI]

    Bonito, Andrea; Lee, Sanghyun

    2015-01-01T23:59:59.000Z

    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.

  18. Babcock and Wilcox BR-100 100-ton rail/barge spent fuel shipping cask

    SciTech Connect (OSTI)

    none,

    1990-02-01T23:59:59.000Z

    This Preliminary Design Report (PDR) provides a detailed description of the design, analyses, and testing programs for the BR-100 cask. The BR-100 is a Type B(U) cask designed for transport by rail or barge. This report presents the preliminary analyses and tests which have been performed for the BR-100 and outlines the confirmatory analyses and tests which will be performed.

  19. The oil price really is a speculative bubble

    E-Print Network [OSTI]

    Eckaus, Richard S.

    2008-01-01T23:59:59.000Z

    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 ...

  20. Geometrical Arrangements of a Collection of Bubbles Roman urikovic

    E-Print Network [OSTI]

    Durikovic, Roman

    . ____________________________________________________________________________________________________________________________________ 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

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

    E-Print Network [OSTI]

    Eppstein, David

    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

  2. Acceleration of Preconditioned Krylov Solvers for Bubbly Flow Problems

    E-Print Network [OSTI]

    Vuik, Kees

    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

  3. Solvent dependent branching between C-I and C-Br bond cleavage following 266 nm excitation of CH{sub 2}BrI

    SciTech Connect (OSTI)

    Anderson, Christopher P.; Spears, Kenneth G.; Wilson, Kaitlynn R.; Sension, Roseanne J. [Department of Chemistry and Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Department of Chemistry and Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2013-11-21T23:59:59.000Z

    It is well known that ultraviolet photoexcitation of halomethanes results in halogen-carbon bond cleavage. Each halogen-carbon bond has a dominant ultraviolet (UV) absorption that promotes an electron from a nonbonding halogen orbital (n{sub X}) to a carbon-halogen antibonding orbital (?*{sub C-X}). UV absorption into specific transitions in the gas phase results primarily in selective cleavage of the corresponding carbon-halogen bond. In the present work, broadband ultrafast UV-visible transient absorption studies of CH{sub 2}BrI reveal a more complex photochemistry in solution. Transient absorption spectra are reported spanning the range from 275 nm to 750 nm and 300 fs to 3 ns following excitation of CH{sub 2}BrI at 266 nm in acetonitrile, 2-butanol, and cyclohexane. Channels involving formation of CH{sub 2}Br + I radical pairs, iso-CH{sub 2}Br-I, and iso-CH{sub 2}I-Br are identified. The solvent environment has a significant influence on the branching ratios, and on the formation and stability of iso-CH{sub 2}Br-I. Both iso-CH{sub 2}Br-I and iso-CH{sub 2}I-Br are observed in cyclohexane with a ratio of ?2.8:1. In acetonitrile this ratio is 7:1 or larger. The observation of formation of iso-CH{sub 2}I-Br photoproduct as well as iso-CH{sub 2}Br-I following 266 nm excitation is a novel result that suggests complexity in the dissociation mechanism. We also report a solvent and concentration dependent lifetime of iso-CH{sub 2}Br-I. At low concentrations the lifetime is >4 ns in acetonitrile, 1.9 ns in 2-butanol and ?1.4 ns in cyclohexane. These lifetimes decrease with higher initial concentrations of CH{sub 2}BrI. The concentration dependence highlights the role that intermolecular interactions can play in the quenching of unstable isomers of dihalomethanes.

  4. Optical characteristics of a HgBr excilamp

    SciTech Connect (OSTI)

    Malinina, A A; Malinin, A N; Shuaibov, A K [Uzhgorod National University, Uzhgorod (Ukraine)

    2013-08-31T23:59:59.000Z

    Optical characteristics of a coaxial HgBr excilamp on multicomponent mercury dibromide vapour mixtures with helium, nitrogen and sulfur hexafluoride are investigated under pumping by a pulse-periodic barrier discharge. Stable excilamp operation was demonstrated at a pump pulse repetition rate of 3 – 9 kHz. The component composition of the working system was determined, which provides a maximal average and pulsed specific radiation power of 48.8 mW cm{sup -3} and 40.6 W cm{sup -3}, respectively, at the efficiency of 7.3 % in the blue-green spectral range with the maximal radiation intensity at the wavelength of 502 nm. The reduction in the radiation power after 2.5 × 10{sup 6} shots is 5 %. Interpretation is given for the results of optimisation of excilamp characteristics. (optical radiation sources)

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

    SciTech Connect (OSTI)

    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

    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.

  6. Plasma jet ignition device

    DOE Patents [OSTI]

    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

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  8. Cu-X-bpy (X ) Cl, Br; bpy ) 4,4-bipyridine) Coordination Polymers: The Stoichiometric

    E-Print Network [OSTI]

    Li, Jing

    the product formation, their structures and topology. Experimental Section Chemicals and Reagents. All with water and acetone and dried in air. I was isolated as a single-phase product. Synthesis of 2 [Cu2Br2 chemicals were used as purchased without further purification, including CuCl2,2H2O (99+%, Aldrich), CuBr2

  9. Coupling of twin rectangular supersonic jets

    E-Print Network [OSTI]

    Raman, G.; Taghavi, Ray

    1998-01-01T23:59:59.000Z

    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 ...

  10. The Georgi Algorithms of Jet Clustering

    E-Print Network [OSTI]

    Shao-Feng Ge

    2014-08-30T23:59:59.000Z

    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.

  11. 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

  12. 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

  13. Advanced thermally stable jet fuels

    SciTech Connect (OSTI)

    Schobert, H.H.

    1999-01-31T23:59:59.000Z

    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).

  14. A Survey of Irradiated Pillars, Globules, and Jets in the Carina Nebul

    E-Print Network [OSTI]

    Hartigan, P; Smith, N; Bally, J

    2015-01-01T23:59:59.000Z

    We present wide-field, deep narrowband H$_2$, Br$\\gamma$, H$\\alpha$, [S II], [O III], and broadband I and K-band images of the Carina star formation region. The new images provide a large-scale overview of all the H$_2$ and Br$\\gamma$ emission present in over a square degree centered on this signature star forming complex. By comparing these images with archival HST and Spitzer images we observe how intense UV radiation from O and B stars affects star formation in molecular clouds. We use the images to locate new candidate outflows and identify the principal shock waves and irradiated interfaces within dozens of distinct areas of star-forming activity. Shocked molecular gas in jets traces the parts of the flow that are most shielded from the intense UV radiation. Combining the H$_2$ and optical images gives a more complete view of the jets, which are sometimes only visible in H$_2$. The Carina region hosts several compact young clusters, and the gas within these clusters is affected by radiation from both the...

  15. Jet physics at HERA, Tevatron and LHC

    E-Print Network [OSTI]

    C. Royon

    2008-11-10T23:59:59.000Z

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

  16. Inclusive jet production at the Tevatron

    SciTech Connect (OSTI)

    Norniella, Olga; /Barcelona, IFAE

    2006-08-01T23:59:59.000Z

    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

  17. Engineering Development of Slurry Bubble Column Reactor (SBCR) Technology

    SciTech Connect (OSTI)

    Toseland, B.A.

    1998-10-29T23:59:59.000Z

    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.

  18. ENGINEERING DEVELOPMENT OF SLURRY BUBBLE COLUMN REACTOR (SBCR) TECHNOLOGY

    SciTech Connect (OSTI)

    Bernard A. Toseland

    1998-06-30T23:59:59.000Z

    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.

  19. Compression-induced stacking fault tetrahedra around He bubbles in Al

    SciTech Connect (OSTI)

    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

    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.

  20. Monte Carlo Tools for Jet Quenching

    E-Print Network [OSTI]

    Korinna Zapp

    2011-09-07T23:59:59.000Z

    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.

  1. 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

  2. Scaling of bubble growth in a porous medium. Topical report

    SciTech Connect (OSTI)

    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

    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.

  3. Photoproduction of jets at NLO

    E-Print Network [OSTI]

    B. W. Harris; J. F. Owens

    1996-08-20T23:59:59.000Z

    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.

  4. The Disc-Jet Connection

    E-Print Network [OSTI]

    Ralph E. Pudritz; Robi Banerjee

    2005-07-11T23:59:59.000Z

    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).

  5. Laser Created Relativistic Positron Jets

    SciTech Connect (OSTI)

    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

    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.

  6. 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]

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

    2001-04-27T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2011-03-01T23:59:59.000Z

    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.

  8. Studies on Ca2+-Doped CeBr3 Scintillating Materials

    SciTech Connect (OSTI)

    Guss, P. [NSTec; Foster, M. E. [SNL; Wong, B. M. [SNL; Doty, F. P. [SNL; Shah, K. [RMD; Squillante, M. [RMD; Glodo, J. [RMD; Yuan, D. [NSTec

    2013-07-03T23:59:59.000Z

    Despite the outstanding scintillation performance characteristics of cerium tribromide (CeBr3) and cerium-activated lanthanum tribromide (LaBr3:Ce), their commercial availability and application is limited due to the difficulties of growing large, crack-free single crystals from these fragile materials. The objective of this investigation was to employ aliovalent doping to increase crystal strength while maintaining the optical properties of the crystal. One divalent dopant (Ca2+) was investigated as a dopant to strengthen CeBr3 without negatively impacting scintillation performance. Ingots containing nominal concentrations of 1.9% of the Ca2+ dopant were grown. Preliminary scintillation measurements are presented for this aliovalently doped scintillator. Ca2+-doped CeBr3 exhibited little or no change in the peak fluorescence emission for 371 nm optical excitation for CeBr3. The structural, electronic, and optical properties of CeBr3 crystals were investigated using the density functional theory within generalized gradient approximation. The calculated lattice parameters are in good agreement with the experimental data. The energy band structures and density of states were obtained. The optical properties of CeBr3, including the dielectric function, were calculated.

  9. Studies on Ca2+-Doped CeBr3 Scintillating Materials

    SciTech Connect (OSTI)

    Guss, P. [NSTec; Foster, M. E. [SNL; Wong, B. M. [SNL; Doty, F. P. [SNL; Shah, K. [RMD; Squillante, M. R. [RMD; Shirwadkar, U. [RMD; Hawrami, R. [RMD; Tower, J. [RMD; Yuan, D. [NSTec

    2013-09-01T23:59:59.000Z

    Despite the outstanding scintillation performance characteristics of cerium tribromide (CeBr3) and cerium-activated lanthanum tribromide (LaBr3:Ce), their commercial availability and application is limited due to the difficulties of growing large, crack-free single crystals from these fragile materials. The objective of this investigation was to employ aliovalent doping to increase crystal strength while maintaining the optical properties of the crystal. One divalent dopant (Ca2+) was investigated as a dopant to strengthen CeBr3 without negatively impacting scintillation performance. Ingots containing nominal concentrations of 1.9% of the Ca2+ dopant were grown. Preliminary scintillation measurements are presented for this aliovalently doped scintillator. Ca2+-doped CeBr3 exhibited little or no change in the peak fluorescence emission for 371 nm optical excitation for CeBr3. The structural, electronic, and optical properties of CeBr3 crystals were investigated using the density functional theory within generalized gradient approximation. The calculated lattice parameters are in good agreement with the experimental data. The energy band structures and density of states were obtained. The optical properties of CeBr3, including the dielectric function, were calculated.

  10. CeBr3 as a High-Resolution Gamma-Ray Detector

    SciTech Connect (OSTI)

    Michael Reed, Paul Guss, Christopher Contreras

    2008-11-13T23:59:59.000Z

    Lanthanum halide (LaBr3:Ce) scintillators have been well-documented as high-resolution gamma-ray detectors that are operated at room temperature. These scintillators have better resolution (<3% at 662 keV) relative to sodium iodide (NaI(Tl)) scintillators (7% at 662 keV), but the naturally occurring radioactive isotope 138La causes self-activity in the crystal that occludes portions of the gamma-ray spectrum. This selfactivity limits the use of LaBr3:Ce in high-sensitivity applications. Cerium, the dopant in the LaBr3:Ce matrix possesses useful scintillation properties, and its selfactivity is on the order of 3750 times less than La; however, Ce has not been fully characterized as the chief component in a scintillation detector. This work investigated Ce as the key scintillation matrix component in a scintillation detector with the hypothesis that CeBr3 promises energy resolution comparable or superior to LaBr3:Ce. The researchers involved with this work believe that CeBr3 may be the answer to obtaining high-temperature, high-resolution spectra with greater sensitivity than LaBr3:Ce.

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

    ScienceCinema (OSTI)

    Glaser, Don

    2011-04-28T23:59:59.000Z

    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.

  12. Buoyancy and Penrose Process Produce Jets from Rotating Black Holes

    E-Print Network [OSTI]

    Semenov, V S; Heyn, M F

    2014-01-01T23:59:59.000Z

    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...

  13. Synthetic jets at large Reynolds number and comparison to continuous jets

    SciTech Connect (OSTI)

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

    2001-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  15. 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...

  16. Generation of laser-induced cavitation bubbles with a digital hologram

    E-Print Network [OSTI]

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

    2008-01-01T23:59:59.000Z

    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,”

  17. 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...

  18. 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...

  19. 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. -...

  20. 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...

  1. Measurement of the Ratio of Branching Fractions Br(Bs -> Ds- pi+)/Br(B -> D- pi+) at CDF-II

    SciTech Connect (OSTI)

    Furic, Ivan Kresimir; /MIT

    2004-03-01T23:59:59.000Z

    The measurement of B{sub s}{sup 0} mixing is one of the flagship analyses for the Run II B physics program. The sensitivity of the measurement to the frequency of B{sub s}{sup 0} oscillations strongly depends on the number of reconstructed B{sub s}{sup 0} mesons. They present the measurement of the ratio of branching fractions Br(B{sub s}{sup 0} {yields} D{sub s}{sup -}{pi}{sup +})/Br(B{sup 0} {yields} D{sup -}{pi}{sup +}), which directly influences the number of B{sub s}{sup 0} events available for the measurement of B{sub s}{sup 0} mixing at CDF-II. They analyze 115 pb{sup -1} of data collected with the CDF-II detector in p{bar p} collisions at {radical}s = 1.96 TeV using a novel displaced track trigger. They reconstruct 78 {+-} 11 B{sub s}{sup 0} {yields} D{sub s}{sup -}{pi}{sup +} decays at 1153 {+-} 45 B{sup 0} {yields} D{sup -}{pi}{sup +} decays with good signal to background ratio. This is the world's largest sample of fully reconstructed B{sub s}{sup 0} {yields} D{sub s}{sup -}{pi}{sup +} decays. They find the ratio of production fractions multiplied by the ratio of branching fractions to be: f{sub s}/f{sub d} {center_dot} Br(B{sub s}{sup 0} {yields} D{sub s}{sup -}{pi}{sup +})/Br(B{sup 0} {yields} D{sup -}{pi}{sup +}) = 0.325 {+-} 0.046(stat) {+-} 0.034(syst) {+-} 0.084 (BR). Using the world average value of f{sub s}/f{sub d} = 0.26 {+-} 0.03, we infer that the ratio of branching fractions is: Br(B{sub s}{sup 0} {yields} D{sub s}{sup -}{pi}{sup +})/Br(B{sup 0} {yields} D{sup -}{pi}{sup +}) = 1.25 {+-} 0.18(stat) {+-} 0.13(syst) {+-} 0.32(BR) {+-} 0.14(PR) where the last uncertainty is due to the uncertainty on the world average measurement of the ratio of B{sub s}{sup 0} to B{sup 0} production rates, f{sub s}/f{sub d}.

  2. Delayed neutron studies of separated isotopes of Br, Rb, I, and Cs

    E-Print Network [OSTI]

    Reeder, R L; Wright, J F

    1976-01-01T23:59:59.000Z

    Discusses delayed neutron studies of separated isotopes of Br, Rb, I, and Cs are currently in progress at the Spectrometer for On-Line Analysis of Radionuclides (SOLAR) facility operated by Battelle, Pacific Northwest Laboratories. (2 refs).

  3. REACTION AND DEACTIVATION OF HC1 (v = 1, 2) BY Cl, Br, AND H ATOMS

    E-Print Network [OSTI]

    Macdonald, R.G.

    2013-01-01T23:59:59.000Z

    1, 2) by Cl, Br, and H ATOMS R. G. Macdonald and C. Bradleyrelaxation of HCl by reactive atoms, av = - 1, at 294 K.aof HCl(v = 2) by Cl atoms from decay rate measurements~ Tab

  4. BrUCE BUrGETT School of Interdisciplinary Arts and Sciences

    E-Print Network [OSTI]

    Queitsch, Christine

    8 BrUCE BUrGETT School of Interdisciplinary Arts and Sciences Burgett earned his bachelor and Scott previously held the title of director of their respective programs. #12;

  5. The formation of gas bubbles at submerged orifices

    E-Print Network [OSTI]

    Hayes, William Bell

    2013-10-04T23:59:59.000Z

    . 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...

  6. 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

  7. Numerical Simulations of Bouncing Jets

    E-Print Network [OSTI]

    Lee, Sanghyun

    2014-07-18T23:59:59.000Z

    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...

  8. Fluid jet electric discharge source

    DOE Patents [OSTI]

    Bender, Howard A. (Ripon, CA)

    2006-04-25T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Ho, Chu Eu

    2005-01-01T23:59:59.000Z

    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 ...

  10. Combining Resummed Higgs Predictions Across Jet Bins

    E-Print Network [OSTI]

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

    2013-12-16T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Gerardi, Craig

    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 ...

  12. Measurement of BR(Bu to phi K)/BR(Bu to J/psi K) at the collider detector at Fermilab

    SciTech Connect (OSTI)

    Napora, Robert A

    2004-10-01T23:59:59.000Z

    This thesis presents evidence for the decay mode B{sup {+-}} {yields} {phi}K{sup {+-}} in p{bar p} collisions at {radical}s = 1.96 TeV using (120 {+-} 7)pb{sup -1} of data collected by the Collider Detector at Fermilab (CDF). This signal is then used to measure the branching ratio relative to the decay mode B{sup {+-}} {yields} J/{psi}K{sup {+-}}. The measurement starts from reconstructing the two decay modes: B{sup {+-}} {yields} {phi}K{sup {+-}}, where {phi} {yields} K{sup +}K{sup -} and B{sup {+-}} {yields} J/{psi}K{sup {+-}}, where J/{psi} {yields} {mu}{sup +}{mu}{sup -}. The measurement yielded 23 {+-} 7 B{sup {+-}} {yields} {phi}K{sup {+-}} events, and 406 {+-} 26 B{sup {+-}} {yields} J/{psi}K{sup {+-}} events. The fraction of B{sup {+-}} {yields} J/{psi}K{sup {+-}} events where the J/{psi} subsequently decayed to two muons (as opposed to two electrons) was found to be f{sub {mu}{mu}} = 0.839 {+-} 0.066. The relative branching ratio of the two decays is then calculated based on the equation: BR(B{sup {+-}} {yields} {phi}K{sup {+-}})/BR(B{sup {+-}} {yields} J/{psi}K{sup {+-}}) = N{sub {phi}K}/N{sub {psi}K} {center_dot}f{sub {mu}{mu}} BR(J/{psi} {yields} {mu}{sup +}{mu}{sup -})/BR({phi} {yields} K{sup +}K{sup -}) {epsilon}{sub {mu}{mu}}K/{epsilon}KKK R({epsilon}{sub iso}). The measurement finds BR(B{sup {+-}} {yields} {phi}K{sup {+-}})/BR(B{sup {+-}} {yields} J/{psi}K{sup {+-}}) = 0.0068 {+-} 0.0021(stat.) {+-} 0.0007(syst.). The B{sup {+-}} {yields} {phi}K{sup {+-}} branching ratio is then found to be BR(B{sup {+-}} {yields} {phi}K{sup {+-}}) = [6.9 {+-} 2.1(stat.) {+-} 0.8(syst.)] x 10{sup -6}. This value is consistent with similar measurements reported by the e{sup +}e{sup -} collider experiments BaBar[1], Belle[2], and CLEO[3].

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

    E-Print Network [OSTI]

    Tanveer, Saleh

    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

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

    E-Print Network [OSTI]

    Wehrli, Bernhard

    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

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

    E-Print Network [OSTI]

    Chang, Hsueh-Chia

    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

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

    E-Print Network [OSTI]

    Suslick, Kenneth S.

    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

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

    E-Print Network [OSTI]

    Ohl, Claus-Dieter

    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

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

    E-Print Network [OSTI]

    Zhao, Tianshou

    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

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

    E-Print Network [OSTI]

    Atwater, Harry

    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

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

    E-Print Network [OSTI]

    Han, Ji-seok

    2009-05-15T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Dennin, Michael

    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

  2. LDV Measurement of Confined Parallel Jet Mixing

    SciTech Connect (OSTI)

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

    2001-01-31T23:59:59.000Z

    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.

  3. Jet physics in Run 2 at CDF

    SciTech Connect (OSTI)

    Field, R.; /Florida U.

    2005-01-01T23:59:59.000Z

    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.

  4. Nuclear Composition of Magnetized GRB Jets

    E-Print Network [OSTI]

    Shibata, Sanshiro

    2015-01-01T23:59:59.000Z

    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...

  5. PHYSICAL PARAMETERS OF STANDARD AND BLOWOUT JETS

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Alam, Syed Aftab

    2012-06-07T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Huang, Huaxiong

    , 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

  8. Space variations in axis height of the jet stream core

    E-Print Network [OSTI]

    Leutwyler, Cooke Hearon

    1965-01-01T23:59:59.000Z

    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...

  9. Why Do Disks Form Jets?

    E-Print Network [OSTI]

    D Lynden-Bell

    2002-03-27T23:59:59.000Z

    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.

  10. Br-Cl-Na systematics in Illinois basin fluids: Constraints on fluid origin and evolution

    SciTech Connect (OSTI)

    Walter, L.M.; Huston, T.J. (Washington Univ., St. Louis, Missouri (USA)); Stueber, A.M. (Southern Illinois Univ., Edwardsville (USA))

    1990-04-01T23:59:59.000Z

    The authors present here bromide, chloride, and sodium data for fluids from reservoirs of Ordovician through Pennsylvania age in the Illinois basic which suggest that remnant marine fluids contribute significantly to fluid Cl budgets. Cl/Br and NaBr ratios for Ordovician through Devonian formation fluids are relatively uniform and near those for seawater, despite greater than a factor of ten range in Cl concentration. In contrast, fluids from Mississippian and Pennsylvanian reservoirs, separated from older reservoirs by the New Albany Shale Group, have more variable fluid Cl/Br and Na/Br ratios, most of which are significantly greater then those of seawater. The 1:1 stoichiometry of Cl and Na increases for Mississippian and Pennsylvanian formation fluids is consistent with halite dissolution. Nevertheless, Br systematics and mass-balance considerations indicate that he overall Cl budget of Illinois basin formation fluids appears to be more significantly influenced by the contribution from subaerially evaporated seawater than by halite dissolution.

  11. Miniconference on astrophysical jets P. M. Bellan

    E-Print Network [OSTI]

    Bellan, Paul M.

    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

  12. Jet multiplicities as the QGP thermometer

    E-Print Network [OSTI]

    I. M. Dremin; O. S. Shadrin

    2006-02-10T23:59:59.000Z

    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.

  13. On He bubbles in neutron irradiated SYLRAMIC type SiC fibers

    SciTech Connect (OSTI)

    Gelles, David S.; Youngblood, Gerald E.

    2006-03-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Stoller, Roger E [ORNL] [ORNL

    2013-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    1986-06-01T23:59:59.000Z

    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.

  16. $W/Z$ + jets results from CDF

    SciTech Connect (OSTI)

    Camarda, Stefano; /Barcelona, IFAE

    2010-01-01T23:59:59.000Z

    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.

  17. Coalescence of bubbles and drops in an outer fluid

    E-Print Network [OSTI]

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

    2014-07-24T23:59:59.000Z

    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.

  18. Mechanical Feedback: From stellar wind bubbles to starbursts

    E-Print Network [OSTI]

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

    2001-03-20T23:59:59.000Z

    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.

  19. Possible Bubbles of Spacetime Curvature in the South Pacific

    E-Print Network [OSTI]

    Tippett, Benjamin K

    2012-01-01T23:59:59.000Z

    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 ...

  20. Measurement of \\Gamma_{ee}(J/\\psi)*Br(J/\\psi->e^+e^-) and \\Gamma_{ee}(J/\\psi)*Br(J/\\psi->\\mu^+\\mu^-)

    E-Print Network [OSTI]

    Anashin, V V; Baldin, E M; Barladyan, A K; Barnyakov, A Yu; Barnyakov, M Yu; Baru, S E; Bedny, I V; Beloborodova, O L; Blinov, A E; Blinov, V E; Bobrov, A V; Bobrovnikov, V S; Bogomyagkov, A V; Bondar, A E; Bondarev, D V; Buzykaev, A R; Eidelman, S I; Glukhovchenko, Yu M; Gulevich, V V; Gusev, D V; Karnaev, S E; Karpov, G V; Karpov, S V; Kharlamova, T A; Kiselev, V A; Kononov, S A; Kotov, K Yu; Kravchenko, E A; Kulikov, V F; Kurkin, G Ya; Kuper, E A; Levichev, E B; Maksimov, D A; Malyshev, V M; Maslennikov, A L; Medvedko, A S; Meshkov, O I; Mishnev, S I; Morozov, I I; Muchnoi, N Yu; Neufeld, V V; Nikitin, S A; Nikolaev, I B; Okunev, I N; Onuchin, A P; Oreshkin, S B; Orlov, I O; Osipov, A A; Peleganchuk, S V; Pivovarov, S G; Piminov, P A; Petrov, V V; Poluektov, A O; Popkov, I N; Prisekin, V G; Ruban, A A; Sandyrev, V K; Savinov, G A; Shamov, A G; Shatilov, D N; Shwartz, B A; Simonov, E A; Sinyatkin, S V; Skovpen, Yu I; Skrinsky, A N; Smaluk, V V; Sokolov, A V; Sukharev, A M; Starostina, E V; Talyshev, A A; Tayursky, V A; Telnov, V I; Tikhonov, Yu A; Todyshev, K Yu; Tumaikin, G M; Usov, Yu V; Vorobiov, A I; Yushkov, A N; Zhilich, V N; Zhulanov, V V; Zhuravlev, A N

    2009-01-01T23:59:59.000Z

    The products of the electron width of the J/\\psi meson and the branching fraction of its decays to the lepton pairs were measured using data from the KEDR experiment at the VEPP-4M electron-positron collider. The results are \\Gamma_{ee}(J/\\psi)*Br(J/\\psi->e^+e^-)=0.3323\\pm0.0064\\pm0.0048 keV, \\Gamma_{ee}(J/\\psi)*Br(J/\\psi->\\mu^+\\mu^-)=0.3318\\pm0.0052\\pm0.0063 keV. Assuming e\\mu universality and using the world average value of the lepton branching fraction, we also determine the leptonic \\Gamma_{ll}=5.59\\pm0.12 keV and total \\Gamma=94.1\\pm2.7 keV widths of the J/\\psi meson.

  1. Atmospheric-pressure plasma jet

    DOE Patents [OSTI]

    Selwyn, Gary S. (Los Alamos, NM)

    1999-01-01T23:59:59.000Z

    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.

  2. Can Protostellar Jets Drive Supersonic Turbulence in Molecular Clouds?

    E-Print Network [OSTI]

    Robi Banerjee; Ralf S. Klessen; Christian Fendt

    2007-06-25T23:59:59.000Z

    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.

  3. An inkjet vision measurement technique for high-frequency jetting

    SciTech Connect (OSTI)

    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

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  5. Measuring BR($h \\to \\tau ^+ \\tau ^-$) at the ILC: a full simulation study

    E-Print Network [OSTI]

    Kawada, Shin-ichi; Suehara, Taikan; Takahashi, Tohru; Tanabe, Tomohiko; Yokoyama, Harumichi

    2015-01-01T23:59:59.000Z

    We evaluate the expected measurement accuracy of the branching ratio of the Standard Model Higgs boson decaying into tau pairs at the ILC with a full simulation of the ILD detector concept. We assume a Higgs mass of 125 GeV, a branching ratio of BR($h \\to \\tau ^+ \\tau ^-$) = 6.32%, a beam polarization of electron (positron) of -0.8(+0.3), and an integrated luminosity of 250 fb$^{-1}$. The Higgs-strahlung process $e^+ e^- \\to Zh$ with $Z \\to q\\overline{q}$ is analyzed. We estimate the measurement accuracy of the branching ratio $\\Delta (\\sigma \\times \\mathrm{BR}) / (\\sigma \\times \\mathrm{BR})$ to be 3.4% with using a multivariate analysis technique.

  6. Oxygen quenching in LAB based liquid scintillator and nitrogen bubbling model

    E-Print Network [OSTI]

    Xiao Hua-Lin

    2009-04-08T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  8. Synthesis and Screening of Thin Films in the CeCl3-CeBr3 System...

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

    compositions, crystal structures, and luminescence characteristics. Citation: Matson DW, GL Graff, JL Male, BR Johnson, Z Nie, AG Joly, and LC Olsen.2010."Synthesis and Screening...

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

    E-Print Network [OSTI]

    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

    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...

  10. Dark jets in solar coronal holes

    E-Print Network [OSTI]

    Young, Peter R

    2015-01-01T23:59:59.000Z

    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...

  11. Jet Reconstruction in Heavy Ion Collisions

    E-Print Network [OSTI]

    Sevil Salur

    2009-05-12T23:59:59.000Z

    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.

  12. Composite Octet Searches with Jet Substructure

    SciTech Connect (OSTI)

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

    2012-02-14T23:59:59.000Z

    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.

  13. 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

  14. 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."

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

    E-Print Network [OSTI]

    California at Davis, University of

    , 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

  16. EFFECTIVE EQUATIONS FOR SOUND AND VOID WAVE PROPAGATION IN BUBBLY FLUIDS

    E-Print Network [OSTI]

    Smereka, Peter

    ;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

  17. Bubble formation and Kr distribution in Kr-irradiated UO2

    SciTech Connect (OSTI)

    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

    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.

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

    SciTech Connect (OSTI)

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

    2013-08-08T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Velarde, Jorge Javier

    1996-01-01T23:59:59.000Z

    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...

  20. Jet physics and the underlying event at the Tevatron

    SciTech Connect (OSTI)

    Field, Rick; /Florida U.

    2005-08-01T23:59:59.000Z

    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.

  1. Jet spoiler arrangement for wind turbine

    DOE Patents [OSTI]

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

    1985-01-01T23:59:59.000Z

    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.

  2. Jet spoiler arrangement for wind turbine

    DOE Patents [OSTI]

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

    1983-09-15T23:59:59.000Z

    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.

  3. Squark and gluino production with jets

    SciTech Connect (OSTI)

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

    2005-10-01T23:59:59.000Z

    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.

  4. Hypersonic Buckshot: Astrophysical Jets as Heterogeneous Collimated Plasmoids

    E-Print Network [OSTI]

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

    2008-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    McDonald, Kirk

    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

  6. COMBINED ADAPTIVE CONTROLLER FOR UAV GUIDANCE B.R. Andrievsky, A.L. Fradkov

    E-Print Network [OSTI]

    COMBINED ADAPTIVE CONTROLLER FOR UAV GUIDANCE B.R. Andrievsky, A.L. Fradkov Institute for Problems vehicle (UAV) homing guidance system is pro- posed. The adaptation algorithm provides prescribed attitude adaptive controller in the case of significant uncertainty of the UAV parameters and time dependence

  7. The solvation of Cl , Br , and I in acetonitrile clusters: Photoelectron spectroscopy and molecular dynamics simulations

    E-Print Network [OSTI]

    Perera, Lalith

    The solvation of Cl , Br , and I in acetonitrile clusters: Photoelectron spectroscopy and molecular in acetonitrile clusters CH3CN n with n 1­33, 1­40, and 1­55, respectively, taken with 7.9 eV photon energy. Anion simulations of halide­acetonitrile clusters reproduce the measured stabilization energies and generate full

  8. 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]

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

    2014-09-16T23:59:59.000Z

    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...

  9. COMPUTATIONAL AND EXPERIMENTAL MODELING OF SLURRY BUBBLE COLUMN REACTORS

    SciTech Connect (OSTI)

    Paul Lam; Dimitri Gidaspow

    2001-08-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

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

    2012-06-30T23:59:59.000Z

    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.

  11. Experimental investigation of bubbling in particle beds with high solid holdup

    SciTech Connect (OSTI)

    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

    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)

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

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2008-01-15T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2006-03-02T23:59:59.000Z

    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.

  14. Feasibility Study for a New Business Jet

    E-Print Network [OSTI]

    Mousa, Yasser Abdullah

    2009-05-15T23:59:59.000Z

    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...

  15. Inclusive jet cross section at CDF

    SciTech Connect (OSTI)

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

    2005-01-01T23:59:59.000Z

    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.

  16. Measuring collinear W emissions inside jets

    E-Print Network [OSTI]

    Frank Krauss; Petar Petrov; Marek Schoenherr; Michael Spannowsky

    2014-03-19T23:59:59.000Z

    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.

  17. New results on jet fragmentation at CDF

    SciTech Connect (OSTI)

    Jindariani, Sergo; /Florida U.

    2006-12-01T23:59:59.000Z

    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.

  18. The Infrared Jet in 3C31

    E-Print Network [OSTI]

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

    2015-01-01T23:59:59.000Z

    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 ...

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

    SciTech Connect (OSTI)

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

    2005-02-03T23:59:59.000Z

    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.

  20. Size Effect on Nuclear Gamma-Ray Energy Spectra Acquired by Different Sized CeBr3, LaBr3:Ce, and NaI:Tl Gamma-Ray Detectors

    SciTech Connect (OSTI)

    Guss, Paul [NSTec; Reed, Michael [NSTec; Yuan, Ding [NSTec; Beller, Denis [UNLV; Cutler, Matthew [UNLV; Contreras, Chris [UNLV; Mukhopadhyay, Sanjoy [NSTec; Wilde, Scott UNLV

    2014-03-01T23:59:59.000Z

    Gamma-ray energy spectra were acquired for different sizes of cerium tribromide (CeBr3), cerium-doped lanthanum tribromide (LaBr3:Ce), and thallium-doped sodium iodide (NaI:Tl) detectors. A comparison was conducted of the energy resolution and detection efficiency of these scintillator detectors for different sizes of detectors. The results of this study are consistent with the observation that for each size detector, LaBr3:Ce offers better resolution than either a CeBr3 or NaI:Tl detector of the same size. In addition, CeBr3 and LaBr3:Ce detectors could resolve some closely spaced peaks in the spectra of several radioisotopes that NaI:Tl could not. As the detector size increased, all three detector materials exhibited higher efficiency, albeit with slightly reduced resolution. Significantly, the very low intrinsic activity of CeBr3 is also demonstrated in this study, which, when combined with energy resolution characteristics for a range of detector sizes, could lead to an improved ability to detect special nuclear materials compared to the other detectors.

  1. Sound Waves from Quenched Jets

    E-Print Network [OSTI]

    Vladimir Khachatryan; Edward Shuryak

    2011-08-15T23:59:59.000Z

    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.

  2. PHOTOSPHERIC EMISSION FROM STRATIFIED JETS

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    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

    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,...

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

    E-Print Network [OSTI]

    Boughezal, Radja; Liu, Xiaohui

    2015-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Lynn, Alan [University of New Mexico

    2011-02-18T23:59:59.000Z

    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.

  6. MULTIWAVELENGTH OBSERVATIONS OF THE SS 433 JETS

    SciTech Connect (OSTI)

    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

    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.

  7. 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)...

  8. MS 211 -CALCULO NUMERICO -1o http://www.ime.unicamp.br/ ms211/

    E-Print Network [OSTI]

    Sussner, Peter

    MS 211 - C´ALCULO NUM´ERICO - 1o SEM/2010 http://www.ime.unicamp.br/ ms211/ Turma Per triangulares. Elimina¸c~ao de Gauss. Pivoteamento Parcial. Decomposi¸c~ao LU. M´etodos iterativos de Jacobi e¸c~ao num´erica. 4. Equa¸c~oes n~ao-lineares: M´etodo da bissec¸c~ao . M´etodo de Newton. M´etodo da Secante

  9. A mathematical model of a Zn/Br? cell on charge

    E-Print Network [OSTI]

    Mader, Michael Joseph

    2012-06-07T23:59:59.000Z

    to the Continuous Model for the Copper Electrowinning Example Vll. Demonstration that the Effective Separator Thickness is an Independent Parameter Vill. Comparison of' the One Step to the Continuous Model for the Zn 'Brs Cell 6 o 70 IX. Current Densities... Subject: Chemical Engineering A MATHEMATICAL MODEL OF A ZN, 'BR, CELL ON CHARGE A Thesi bt MICHAEL JOSEPH MADER Approved as to style and content by: Ralph E. 6'hite (Chairman of Committee) Charles lover Bart Childs (Mentber) Charles D. H lland...

  10. Investigation into Nanostructured Lanthanum Halides and CeBr{sub 3} for Nuclear Radiation Detection

    SciTech Connect (OSTI)

    Guss, P., Guise, R., Mukhopadhyay, S., Yuan, D.

    2011-06-22T23:59:59.000Z

    This slide-show presents work on radiation detection with nanostructured lanthanum halides and CeBr{sub 3}. The goal is to extend the gamma energy response on both low and high-energy regimes by demonstrating the ability to detect low-energy x-rays and relatively high-energy activation prompt gamma rays simultaneously using the nano-structured lanthanum bromide, lanthanum fluoride, cerium bromide, or other nanocrystal material. Homogeneous and nano structure cases are compared.

  11. Abundances of s-process elements in planetary nebulae: Br, Kr & Xe

    E-Print Network [OSTI]

    Y. Zhang; R. Williams; E. Pellegrini; K. Cavagnolo; J. A. Baldwin; B. Sharpee; M. Phillips; X. -W. Liu

    2006-05-06T23:59:59.000Z

    We identify emission lines of post-iron peak elements in very high signal-to-noise spectra of a sample of planetary nebulae. Analysis of lines from ions of Kr and Xe reveals enhancements in most of the PNe, in agreement with the theories of s-process in AGB star. Surprisingly, we did not detect lines from Br even though s-process calculations indicate that it should be produced with Kr at detectable levels.

  12. cnEiFrnr,:-BR,1;q*tsE ns John Franks

    E-Print Network [OSTI]

    Short, Daniel

    cnEiFrnr,:- BR,1;q*tsE ns Acid rain John Franks The liDk betwccn sulphur at|d dtrogen odde5 sofe.i,rc fro; th..f..ts torhesethe6xh6ustsofmiilionsol porlol of acid rain, little has been don. Acid rain was mntioned by Bdish chemistRobenAngus Smirhas a factor in lhe air a.ound Manchesterand 'cor

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

    SciTech Connect (OSTI)

    Stevens, John

    2013-12-31T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Misao Sasaki; Dong-han Yeom

    2014-12-25T23:59:59.000Z

    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.

  15. Optimization of electrode characteristics for the Br2/H2 redox flow cell

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Tucker, Michael C.; Cho, Kyu Taek; Weber, Adam Z.; Lin, Guangyu; Nguyen, Trung V.

    2014-10-01T23:59:59.000Z

    The Br2/H2 redox flow cell shows promise as a high-power, low-cost energy storage device. The effect of various aspects of material selection, processing, and assembly of electrodes on the operation, performance, and efficiency of the system is determined. In particular, (+) electrode thickness, cell compression, hydrogen pressure, and (?) electrode architecture are investigated. Increasing hydrogen pressure and depositing the (?) catalyst layer on the membrane instead of on the carbon paper backing layers have a large positive impact on performance, enabling a limiting current density above 2 A cm?2 and a peak power density of 1.4 W cm?2. Maximum energy efficiency of 79 % is achieved. In addition, the root cause of limiting-current behavior in this system is elucidated, where it is found that Br? reversibly adsorbs at the Pt (?) electrode for potentials exceeding a critical value, and the extent of Br? coverage is potential-dependent. This phenomenon limits maximum cell current density and must be addressed in system modeling and design. These findings are expected to lower system cost and enable higher efficiency.

  16. Spin polarized current injection through HgBr{sub 2} intercalated Bi2212 intrinsic Josephson junctions.

    SciTech Connect (OSTI)

    Ozyuzer, L.; Kurter, C.; Ozdemir, M.; Zasadzinski, J. F.; Gray, K. E.; Hinks, D. G. (Materials Science Division); (Izmir Inst. of Tech.); (Illinois Inst. of Tech.)

    2007-06-01T23:59:59.000Z

    To investigate the effect of polarized current on tunneling characteristics of intrinsic Josephson junctions (IJJs), spin-polarized and spin-degenerate current have been injected through the c-axis of HgBr{sub 2} intercalated Bi{sub 2.1}Sr{sub 1.5}Ca{sub 1.4}Cu{sub 2}O{sub 8+delta} (Bi2212) single crystals on which 10 times 10 mum{sup 2} mesas have been fabricated. These two spin conditions are achieved by depositing either Au (15 nm)/Co (80 nm)/Au (156 nm) multilayers or single Au film on HgBr{sub 2} intercalated Bi2212 with T{sub c} = 74 K followed by photolithography and Ar ion beam etching. The I-V characteristics have been measured with and without a magnetic field parallel to c-axis at 4.2 K. A fine, soft Au wire is used to make a gentle mechanical contact on the top of a particular mesa in the array. Tunneling conductance characteristics were obtained and the magnetic field dependence of sumgap voltage peaks was investigated. These peaks do not change in position with increasing magnetic field for both contact configurations. In addition, the temperature dependence of tunneling characteristics of the IJJs are obtained and existence of pseudogap feature is observed above T{sub c} for HgBr{sub 2} intercalated Bi2212.

  17. Geothermal br Resource br Area Geothermal br Resource br Area...

    Open Energy Info (EERE)

    Basalt K Eburru Geothermal Area Eburru Geothermal Area East African Rift System Kenya Rift Basalt Fukushima Geothermal Area Fukushima Geothermal Area Northeast Honshu Arc...

  18. A study of the self-oscillating jet impingement nozzle

    E-Print Network [OSTI]

    Chinnock, Paul Scott

    1993-01-01T23:59:59.000Z

    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...

  19. Applications of Underexpanded Jets in Hypersonic Aerothermodynamics Research

    E-Print Network [OSTI]

    Riabov, Vladimir V.

    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

  20. Feedback control of flow separation using synthetic jets

    E-Print Network [OSTI]

    Kim, Kihwan

    2006-04-12T23:59:59.000Z

    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...

  1. Images in Emergency Medicine: Irritant Contact Dermatitis from Jet Fuel

    E-Print Network [OSTI]

    Trigger, Christopher C; Eilbert, Wesley

    2009-01-01T23:59:59.000Z

    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

  2. Active noise control of supersonic impinging jet using pulsed microjets

    E-Print Network [OSTI]

    Hong, Seung Hyuck

    2009-01-01T23:59:59.000Z

    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 ...

  3. 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...

  4. Mixing enhancement by use of swirling jets

    SciTech Connect (OSTI)

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

    1993-01-01T23:59:59.000Z

    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.

  5. Extragalactic jets on subpc and large scales

    E-Print Network [OSTI]

    F. Tavecchio

    2007-08-20T23:59:59.000Z

    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.

  6. On the Misalignment of Jets in Microquasars

    E-Print Network [OSTI]

    Thomas J. Maccarone

    2002-09-05T23:59:59.000Z

    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.

  7. Jet Structure in Heavy Ion Collisions

    E-Print Network [OSTI]

    Blaizot, Jean-Paul

    2015-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Pritam Chakraborty; Michael R. Tonks; Giovanni Pastore

    2014-09-01T23:59:59.000Z

    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.

  9. QCD Jet Rates with the Inclusive Generalized kt Algorithms

    E-Print Network [OSTI]

    Erik Gerwick; Ben Gripaios; Steffen Schumann; Bryan Webber

    2013-04-15T23:59:59.000Z

    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.

  10. On the Counter-jet Emission in GRB Afterglows

    SciTech Connect (OSTI)

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

    2010-10-15T23:59:59.000Z

    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.

  11. Gauge/gravity duality and jets in strongly coupled plasma

    E-Print Network [OSTI]

    Paul M. Chesler

    2009-10-08T23:59:59.000Z

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

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

    SciTech Connect (OSTI)

    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

    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.

  13. THE HELICAL JET OF THE VELA PULSAR

    SciTech Connect (OSTI)

    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

    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.

  14. Gamma-Ray Bursts: Jets and Energetics

    E-Print Network [OSTI]

    D. A. Frail

    2003-11-12T23:59:59.000Z

    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.

  15. Enhancement of wall jet transport properties

    DOE Patents [OSTI]

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

    1997-02-04T23:59:59.000Z

    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.

  16. High pressure water jet mining machine

    DOE Patents [OSTI]

    Barker, Clark R. (Rolla, MO)

    1981-05-05T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Seol, Dong Guan

    2009-05-15T23:59:59.000Z

    , 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...

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

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Mahesh, Krishnan

    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

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

    E-Print Network [OSTI]

    Garbe, Christoph S.

    (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

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

    E-Print Network [OSTI]

    Stramski, Dariusz

    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

  2. Large Eddy Simulations of Jet Flow Interactions Within Rod Bundles

    E-Print Network [OSTI]

    Salpeter, Nathaniel O.

    2010-07-14T23:59:59.000Z

    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...

  3. Measurement of $\\boldsymbol{\\ttb}$ production in the tau + jets channel using $\\boldsymbol{p\\bar{p}}$ collisions at $\\boldsymbol{\\sqrt{s} = 1.96}$~TeV

    SciTech Connect (OSTI)

    Abazov, Victor Mukhamedovich; /Dubna, JINR; Abbott, Braden Keim; /Oklahoma U.; Abolins, Maris A.; /Michigan State U.; Acharya, Bannanje Sripath; /Tata Inst.; Adams, Mark Raymond; /Illinois U., Chicago; Adams, Todd; /Florida State U.; Alexeev, Guennadi D.; /Dubna, JINR; Alkhazov, Georgiy D.; /St. Petersburg, INP; Alton, Andrew K.; /Michigan U. /Augustana Coll., Sioux Falls; Alverson, George O.; /Northeastern U.; Alves, Gilvan Augusto; /Rio de Janeiro, CBPF /Nijmegen U.

    2010-08-01T23:59:59.000Z

    We present a measurement of the t{bar t} production cross section multiplied by the branching ratio to tau lepton decaying semi-hadronically ({tau}{sub h}) plus jets, {sigma}(p{bar p} {yields} t{bar t} + X) {center_dot} BR(t{bar t} {yields} {tau}{sub h} + jets), at a center of mass energy {radical}s = 1.96 TeV using 1 fb{sup -1} of integrated luminosity collected with the D0 detector. Assuming a top quark mass of 170 GeV, we measure {sigma}{sub t{bar t}} {center_dot} BR{sub {tau}{sub h}+j} = 0.60{sub -0.22}{sup +0.23}(stat){sub -0.14}{sup +0.15}(syst){+-}0.04 (lumi) pb. In addition, we extract the t{bar t} production cross section using the t{bar t} {yields} {tau}{sub h} + jets topology, with the result {sigma}{sub t{bar t}} = 6.9{sub -1.2}{sup +1.2}(stat){sub -0.7}{sup +0.8}(syst) {+-} 0.4 (lumi) pb. These findings are in good agreement with standard model predictions and measurements performed using other top quark decay channels.

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

    SciTech Connect (OSTI)

    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

    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.

  5. Hydrodynamics of bubble columns with application to Fischer-Tropsch synthesis

    E-Print Network [OSTI]

    Raphael, Matheo Lue

    1988-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Haque, Mohammad Shamsul

    1967-01-01T23:59:59.000Z

    ) 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...

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    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

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

    E-Print Network [OSTI]

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

    2008-07-01T23:59:59.000Z

    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.

  9. Studying Z/gamma*+Jet Production

    SciTech Connect (OSTI)

    Nilsen, Henrik Wold; /Freiburg U.

    2009-07-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Valasek, John

    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

  11. 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]

    Snoeijer, Jacco

    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

  12. br Owner br Facility br Type br Capacity br MW br Commercial...

    Open Energy Info (EERE)

    Magmatic Mendeleevskaya Geothermal Power Plant Ministry of Natural Resources of Russia Single Flash MW Mendeleevskaya Geothermal Area Kuril Kamchatka Arc Mindanao GEPP...

  13. HYPERSONIC BUCKSHOT: ASTROPHYSICAL JETS AS HETEROGENEOUS COLLIMATED PLASMOIDS

    SciTech Connect (OSTI)

    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

    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.

  14. Jet Vetoes Interfering with H->WW

    E-Print Network [OSTI]

    Ian Moult; Iain W. Stewart

    2014-09-08T23:59:59.000Z

    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.

  15. The Rapidity Dependence of Jet Quenching

    E-Print Network [OSTI]

    Thorsten Renk

    2014-06-26T23:59:59.000Z

    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.

  16. The interaction between two radial jets

    E-Print Network [OSTI]

    Gruber, Thomas Clifton

    2012-06-07T23:59:59.000Z

    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...

  17. Models comparison for JET polarimeter data

    SciTech Connect (OSTI)

    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

    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].

  18. HOT ELECTROMAGNETIC OUTFLOWS. II. JET BREAKOUT

    SciTech Connect (OSTI)

    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

    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.

  19. Dynamics, Structure, and Emission of Electron-Positron Jets

    E-Print Network [OSTI]

    A. Levinson

    1997-08-10T23:59:59.000Z

    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.

  20. ?Linear Gas Jet with Tailored Density Profile"

    SciTech Connect (OSTI)

    KRISHNAN, Mahadevan

    2012-12-10T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    1995-07-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Khan, Abdul

    2012-10-19T23:59:59.000Z

    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...

  3. Methods for Investigating Gas Bubble Formation in Uranium-Zirconium Alloys

    E-Print Network [OSTI]

    Mews, Kathryn Ann Wright

    2013-05-06T23:59:59.000Z

    . 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...

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    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

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

    SciTech Connect (OSTI)

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

    2009-01-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Peles, Yoav

    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

  7. TEXTURE-INDUCED CAVITATION BUBBLES AND FRICTION REDUCTION IN THE ELROD-ADAMS MODEL

    E-Print Network [OSTI]

    Buscaglia, Gustavo C.

    TEXTURE-INDUCED CAVITATION BUBBLES AND FRICTION REDUCTION IN THE ELROD-ADAMS MODEL Hugo M. Checoa, Friction reduction, Cavitation, Numerical simulation. Symbol Description a, b the pad occupies the region of textures µ dynamic viscosity cavitation boundary 0 cavitated region + pressurized region 1 INTRODUCTION

  8. FARADAY ROTATION DISTRIBUTIONS FROM STELLAR MAGNETISM IN WIND-BLOWN BUBBLES

    SciTech Connect (OSTI)

    Ignace, R. [Department of Physics and Astronomy, East Tennessee State University, Johnson City, TN 37614 (United States)] [Department of Physics and Astronomy, East Tennessee State University, Johnson City, TN 37614 (United States); Pingel, N. M., E-mail: ignace@etsu.edu, E-mail: nmpingle@wisc.edu [Department of Astronomy, University of Wisconsin-Madison, Madison, WI 53711 (United States)

    2013-03-01T23:59:59.000Z

    Faraday rotation is a valuable tool for detecting magnetic fields. Here, the technique is considered in relation to wind-blown bubbles. In the context of spherical winds with azimuthal or split monopole stellar magnetic field geometries, we derive maps of the distribution of position angle (P.A.) rotation of linearly polarized radiation across projected bubbles. We show that the morphology of maps for split monopole fields are distinct from those produced by the toroidal field topology; however, the toroidal case is the one most likely to be detectable because of its slower decline in field strength with distance from the star. We also consider the important case of a bubble with a spherical sub-volume that is field-free to approximate crudely a 'swept-up' wind interaction between a fast wind (or possibly a supernova ejecta shell) overtaking a slower magnetized wind from a prior state of stellar evolution. With an azimuthal field, the resultant P.A. map displays two arc-like features of opposite rotation measure, similar to observations of the supernova remnant G296.5+10.0. We illustrate how P.A. maps can be used to disentangle Faraday rotation contributions made by the interstellar medium versus the bubble. Although our models involve simplifying assumptions, their consideration leads to a number of general robust conclusions for use in the analysis of radio mapping data sets.

  9. Upper Bound for Neutron Emission from Sonoluminescing Bubbles in Deuterated Acetone C. G. Camara,1

    E-Print Network [OSTI]

    Suslick, Kenneth S.

    of the individual ions would be sufficient to generate thermonuclear fusion [2,6]. Experi- mentally, the search dramatically reduces background. Observation of thermonuclear fusion generated by cav- itation in deuterated search for nuclear fusion inside imploding bubbles of degassed deuterated acetone at 0 C driven by a 15

  10. Two-bubble instabilities in quasi-two-dimensional and S.J. COX 2

    E-Print Network [OSTI]

    Cox, Simon

    in which, instead of a glass plate, the foam was bounded below by the surface of a liquid poolTwo-bubble instabilities in quasi-two-dimensional foams M.F. VAZ 1 and S.J. COX 2 1 Instituto de Ci of the experimental set-up on the structure and rheology of two- dimensional foams. We perform the same experiment

  11. Hypersonic Buckshot: Astrophysical Jets as Heterogeneous Collimated Plasmoids

    E-Print Network [OSTI]

    Kristopher Yirak; Adam Frank; Andrew J. Cunningham; Sorin Mitran

    2008-05-30T23:59:59.000Z

    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 shifting from homogeneous to heterogeneous flows are significant as clumps interact with each other and with the inter-clump medium in a variety of ways. Structures which mimic what is expected from pulsed-jet models can form, as can previously unseen ``sub-radial'' 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.

  12. Choked-Flow Inlet Orifice Bubbler for Creating Small Bubbles in Mercury

    SciTech Connect (OSTI)

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

    2013-01-01T23:59:59.000Z

    Pressure waves created in liquid mercury pulsed spallation targets like the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory, induce cavitation damage on the target container. The cavitation damage is thought to limit the lifetime of the target for power levels at and above 1 MW. One way to mitigate the damage would be to absorb the pressure pulse energy into a dispersed population of small bubbles, however, creating a bubble size distribution that is sufficiently large and disperse in mercury is challenging due to the high surface tension. Also, measuring the population is complicated by the opacity and the high level of turbulent mixing. Recent advances in bubble diagnostics by batch sampling the mercury made it possible to compare bubble populations for different techniques in a SNS-1/20th scale test loop. More than 10 bubblers were tested and the most productive bubblers were taken for in-beam testing at the Los Alamos Neutron Science Center (LANSCE) WNR user facility. One bubbler design, referred to as the inlet-orifice bubbler, that showed moderate success in creating populations also has an added advantage that it could easily be included in the existing SNS full-scale mercury target configuration. Improvements to the bubbler were planned including a reduction of the nozzle size to choke the gas injection, thus steadying the injected mass flow and allowing multiple nozzles to work off of a common plenum. For the first time, reliable bubble population data are available in the prototypical target geometry and can be compared with populations that mitigated cavitation damage. This paper presents those experimental results.

  13. Flow in linearly sheared two dimensional foams: from bubble to bulk scale

    E-Print Network [OSTI]

    Gijs Katgert; Andrzej Latka; Matthias E. Möbius; Martin van Hecke

    2009-03-31T23:59:59.000Z

    We probe the flow of two dimensional foams, consisting of a monolayer of bubbles sandwiched between a liquid bath and glass plate, as a function of driving rate, packing fraction and degree of disorder. First, we find that bidisperse, disordered foams exhibit strongly rate dependent and inhomogeneous (shear banded) velocity profiles, while monodisperse, ordered foams are also shear banded, but essentially rate independent. Second, we introduce a simple model based on balancing the averaged drag forces between the bubbles and the top plate and the averaged bubble-bubble drag forces. This model captures the observed rate dependent flows, and the rate independent flows. Third, we perform independent rheological measurements, both for ordered and disordered systems, and find these to be fully consistent with the scaling forms of the drag forces assumed in the simple model, and we see that disorder modifies the scaling. Fourth, we vary the packing fraction $\\phi$ of the foam over a substantial range, and find that the flow profiles become increasingly shear banded when the foam is made wetter. Surprisingly, our model describes flow profiles and rate dependence over the whole range of packing fractions with the same power law exponents -- only a dimensionless number $k$ which measures the ratio of the pre-factors of the viscous drag laws is seen to vary with packing fraction. We find that $k \\sim (\\phi-\\phi_c)^{-1}$, where $\\phi_c \\approx 0.84$, corresponding to the 2d jamming density, and suggest that this scaling follows from the geometry of the deformed facets between bubbles in contact. Overall, our work suggests a route to rationalize aspects of the ubiquitous Herschel-Bulkley (power law) rheology observed in a wide range of disordered materials.

  14. B-R Colors of Globular Clusters in NGC 6166 (A2199)

    E-Print Network [OSTI]

    T. J. Bridges; D. Carter; W. E. Harris; C. J. Pritchet

    1996-04-26T23:59:59.000Z

    We have analysed new R-band photometry of globular clusters in NGC 6166, the cD galaxy in the cooling flow cluster A2199. In combination with the earlier B photometry of Pritchet \\& Harris (1990), we obtain B$-$R colours for $\\sim$ 40 globular clusters in NGC 6166. The mean B$-$R is 1.26 $\\pm$ 0.11, corresponding to a mean [Fe/H] = $-$1 $\\pm$ 0.4. Given that NGC 6166 is one of the most luminous cD galaxies studied to date, our result implies significant scatter in the relationship between mean cluster [Fe/H] and parent galaxy luminosity. We obtain a globular cluster specific frequency of S$_N$ $\\sim$ 9, with a possible range between 5 and 18. This value is inconsistent with the value of S$_N$ $\\leq$ 4 determined earlier by Pritchet \\& Harris (1990) from B-band photometry, and we discuss possible reasons for the discrepancy. Finally, we reassess whether or not cooling flows are an important mechanism for forming globular clusters in gE/cD galaxies.

  15. Fuel loading of PeBR for a long operation life on the lunar surface

    SciTech Connect (OSTI)

    Schriener, T. M. [Inst. for Space and Nuclear Power Studies, Univ. of New Mexico, Albuquerque, NM (United States); Chemical and Nuclear Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States); El-Genk, M. S. [Inst. for Space and Nuclear Power Studies, Univ. of New Mexico, Albuquerque, NM (United States); Chemical and Nuclear Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States); Mechanical Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States)

    2012-07-01T23:59:59.000Z

    The Pellet Bed Reactor (PeBR) power system could provide 99.3 kW e to a lunar outpost for 66 full power years and is designed for no single point failures. The core of this fast energy spectrum reactor consists of three sectors that are neutronically and thermally coupled, but hydraulically independent. Each sector has a separate Closed Brayton Cycle (CBC) loop for energy conversion and separate water heat-pipes radiator panels for heat rejection. He-Xe (40 g/mole) binary gas mixture serves as the reactor coolant and CBC working fluid. On the lunar surface, the emplaced PeBR below grade is loaded with spherical fuel pellets (1-cm in dia.). It is launched unfueled and the pellets are launched in separate subcritical canisters, one for each core sector. This paper numerically simulates the transient loading of a core sector with fuel pellets on the Moon. The simulation accounts for the dynamic interaction of the pellets during loading and calculates the axial and radial distributions of the volume porosity in the sector. The pellets pack randomly with a volume porosity of 0.39 - 0.41 throughout most of the sector, except near the walls the local porosity is higher. (authors)

  16. Determination of the shear and extensional rheology of bubbly liquids with a shear-thinning continuous phase

    E-Print Network [OSTI]

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

    2015-01-17T23:59:59.000Z

    ;#7;?#7;angular velocity, rad/s#7;#7;Introduction Bubbly liquids are dispersions of a gas, ofair, in a liquid with low to medium volume fraction of the bubble phase so that the bubbles remain discrete, unlike foams, and do not phase separate (cream out) readily... °C and 21 °C, to ensure complete hydration of the gum. Some air was incorporated into the solution during stirring and deaerated samples of the continuous phase were obtained by centrifugation at 2250 rpm (500 g) for 5 min. Aeration of ???-hyb...

  17. Experimental study of elliptical jet from sub to supercritical conditions

    SciTech Connect (OSTI)

    Muthukumaran, C. K.; Vaidyanathan, Aravind, E-mail: aravind7@iist.ac.in [Department of Aerospace Engineering, Indian Institute of Space Science and Technology, Trivandrum, Kerala 695547 (India)] [Department of Aerospace Engineering, Indian Institute of Space Science and Technology, Trivandrum, Kerala 695547 (India)

    2014-04-15T23:59:59.000Z

    The jet mixing at supercritical conditions involves fluid dynamics as well as thermodynamic phenomena. All the jet mixing studies at critical conditions to the present date have focused only on axisymmetric jets. When the liquid jet is injected into supercritical environment, the thermodynamic transition could be well understood by considering one of the important fluid properties such as surface tension since it decides the existence of distinct boundary between the liquid and gaseous phase. It is well known that an elliptical liquid jet undergoes axis-switching phenomena under atmospheric conditions due to the presence of surface tension. The experimental investigations were carried out with low speed elliptical jet under supercritical condition. Investigation of the binary component system with fluoroketone jet and N{sub 2} gas as environment shows that the surface tension force dominates for a large downstream distance, indicating delayed thermodynamic transition. The increase in pressure to critical state at supercritical temperature is found to expedite the thermodynamic transition. The ligament like structures has been observed rather than droplets for supercritical pressures. However, for the single component system with fluoroketone jet and fluoroketone environment shows that the jet disintegrates into droplets as it is subjected to the chamber conditions even for the subcritical pressures and no axis switching phenomenon is observed. For a single component system, as the pressure is increased to critical state, the liquid jet exhibits gas-gas like mixing behavior and that too without exhibiting axis-switching behavior.

  18. Massive young stellar object W42-MME: The discovery of an infrared jet using VLT/NACO near-infrared images

    E-Print Network [OSTI]

    Dewangan, L K; Luna, A; Ojha, D K

    2015-01-01T23:59:59.000Z

    We report on the discovery of an infrared jet from a deeply embedded infrared counterpart of 6.7 GHz methanol maser emission (MME) in W42 (i.e. W42-MME). We also investigate that W42-MME drives a parsec-scale H2 outflow, with detection of bow shock feature at ~0.52 pc to the north. The inner ~0.4 pc part of the H2 outflow has a position angle of ~18 deg and the position angle of ~40 deg is found farther away on either side of outflow from W42-MME. W42-MME is detected at wavelengths longer than 2.2 microns and is a massive young stellar object, with the estimated stellar mass of 19+-4 Msun. We map the inner circumstellar environment of W42-MME using VLT/NACO adaptive optics Ks and L' observations at resolutions ~0.2 arcsec and ~0.1 arcsec, respectively. We discover a collimated jet in the inner 4500 AU using the L' band, which contains prominent Br alpha line emission. The jet is located inside an envelope/cavity (extent ~10640 AU) that is tapered at both ends and is oriented along the north-south direction. S...

  19. Leading Particle Production in Light Flavour Jets

    E-Print Network [OSTI]

    Abbiendi, G; Åkesson, P F; Alexander, Gideon; Allison, J; Anderson, K J; Arcelli, S; Asai, S; Ashby, S F; Axen, D A; Azuelos, Georges; Bailey, I; Ball, A H; Barberio, E; Barlow, R J; Batley, J Richard; Baumann, S; Behnke, T; Bell, K W; Bella, G; Bellerive, A; Bentvelsen, Stanislaus Cornelius Maria; Bethke, Siegfried; Betts, S; Biebel, O; Biguzzi, A; Bloodworth, Ian J; Bock, P; Böhme, J; Boeriu, O; Bonacorsi, D; Boutemeur, M; Braibant, S; Bright-Thomas, P G; Brigliadori, L; Brown, R M; Burckhart, Helfried J; Capiluppi, P; Carnegie, R K; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Chrisman, D; Ciocca, C; Clarke, P E L; Clay, E; Cohen, I; Conboy, J E; Cooke, O C; Couchman, J; Couyoumtzelis, C; Coxe, R L; Cuffiani, M; Dado, S; Dallavalle, G M; Dallison, S; Davis, R; de Roeck, A; Dervan, P J; Desch, Klaus; Dienes, B; Dixit, M S; Donkers, M; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Estabrooks, P G; Etzion, E; Fabbri, Franco Luigi; Fanfani, A; Fanti, M; Faust, A A; Feld, L; Ferrari, P; Fiedler, F; Fierro, M; Fleck, I; Frey, A; Fürtjes, A; Futyan, D I; Gagnon, P; Gary, J W; Gaycken, G; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Gingrich, D M; Glenzinski, D A; Goldberg, J; Gorn, W; Grandi, C; Graham, K; Gross, E; Grunhaus, Jacob; Gruwé, M; Hajdu, C; Hanson, G G; Hansroul, M; Hapke, M; Harder, K; Harel, A; Hargrove, C K; Harin-Dirac, M; Hauschild, M; Hawkes, C M; Hawkings, R; Hemingway, Richard J; Herten, G; Heuer, R D; Hildreth, M D; Hill, J C; Hobson, P R; Höcker, Andreas; Hoffman, K; Homer, R James; Honma, A K; Horváth, D; Hossain, K R; Howard, R; Hüntemeyer, P; Igo-Kemenes, P; Imrie, D C; Ishii, K; Jacob, F R; Jawahery, A; Jeremie, H; Jimack, Martin Paul; Jones, C R; Jovanovic, P; Junk, T R; Kanaya, N; Kanzaki, J I; Karapetian, G V; Karlen, D A; Kartvelishvili, V G; Kawagoe, K; Kawamoto, T; Kayal, P I; Keeler, Richard K; Kellogg, R G; Kennedy, B W; Kim, D H; Klier, A; Kobayashi, T; Kobel, M; Kokott, T P; Kolrep, M; Komamiya, S; Kowalewski, R V; Kress, T; Krieger, P; Von Krogh, J; Kühl, T; Kupper, M; Kyberd, P; Lafferty, G D; Landsman, Hagar Yaël; Lanske, D; Lauber, J; Lawson, I; Layter, J G; Lellouch, Daniel; Letts, J; Levinson, L; Liebisch, R; Lillich, J; List, B; Littlewood, C; Lloyd, A W; Lloyd, S L; Loebinger, F K; Long, G D; Losty, Michael J; Lü, J; Ludwig, J; Macchiolo, A; MacPherson, A L; Mader, W F; Mannelli, M; Marcellini, S; Marchant, T E; Martin, A J; Martin, J P; Martínez, G; Mashimo, T; Mättig, P; McDonald, W J; McKenna, J A; McKigney, E A; McMahon, T J; McPherson, R A; Meijers, F; Méndez-Lorenzo, P; Merritt, F S; Mes, H; Meyer, I; Michelini, Aldo; Mihara, S; Mikenberg, G; Miller, D J; Mohr, W; Montanari, A; Mori, T; Nagai, K; Nakamura, I; Neal, H A; Nisius, R; O'Neale, S W; Oakham, F G; Odorici, F; Ögren, H O; Okpara, A N; Oreglia, M J; Orito, S; Pásztor, G; Pater, J R; Patrick, G N; Patt, J; Pérez-Ochoa, R; Petzold, S; Pfeifenschneider, P; Pilcher, J E; Pinfold, James L; Plane, D E; Poli, B; Polok, J; Przybycien, M B; Quadt, A; Rembser, C; Rick, Hartmut; Robins, S A; Rodning, N L; Roney, J M; Rosati, S; Roscoe, K; Rossi, A M; Rozen, Y; Runge, K; Runólfsson, O; Rust, D R; Sachs, K; Saeki, T; Sahr, O; Sang, W M; Sarkisyan-Grinbaum, E; Sbarra, C; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schieck, J; Schmitt, S; Schöning, A; Schröder, M; Schumacher, M; Schwick, C; Scott, W G; Seuster, R; Shears, T G; Shen, B C; Shepherd-Themistocleous, C H; Sherwood, P; Siroli, G P; Skuja, A; Smith, A M; Snow, G A; Sobie, Randall J; Söldner-Rembold, S; Spagnolo, S; Sproston, M; Stahl, A; Stephens, K; Stoll, K; Strom, D; Ströhmer, R; Surrow, B; Talbot, S D; Taras, P; Tarem, S; Teuscher, R; Thiergen, M; Thomas, J; Thomson, M A; Torrence, E; Towers, S; Trefzger, T M; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Van Kooten, R; Vannerem, P; Verzocchi, M; Voss, H; Wäckerle, F; 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; White, J S; Wilson, G W; Wilson, J A; Wyatt, T R; Yamashita, S; Zacek, V; Zer-Zion, D

    2000-01-01T23:59:59.000Z

    The energy distribution and type of the particle with the highest momentum in quark jets are determined for each of the five quark flavours making only minimal model assumptions. The analysis is based on a large statistics sample of hadronic Z0 decays collected with the OPAL detector at the LEP e+e- collider. These results provide a basis for future studies of light flavour production at other centre-of-mass energies. We use our results to study the hadronisation mechanism in light flavour jets and compare the data to the QCD models JETSET and HERWIG. Within the JETSET model we also directly determine the suppression of strange quarks to be gamma_s=0.422+-0.049 (stat.)+-0.059 (syst.) by comparing the production of charged and neutral kaons in strange and non-strange light quark events. Finally we study the features of baryon production.

  20. Phenomenology of Gamma-Ray Jets

    E-Print Network [OSTI]

    Amir Levinson

    2007-09-10T23:59:59.000Z

    We discuss some phenomenological aspects of $\\gamma$-ray emitting jets. In particular, we present calculations of the $\\gamma$-sphere and $\\pi$-sphere for various target photon fields, and employ them to demonstrate how $\\gamma$-ray observations at very high energies can be used to constraint the Doppler factor of the emitting plasma and the production of VHE neutrinos. We also consider the implications of the rapid TeV variability observed in M87 and the TeV blazars, and propose a model for the very rapid TeV flares observed with HESS and MAGIC in some blazars,that accommodates the relatively small Doppler factors inferred from radio observations. Finally, we briefly discuss the prospects for detecting VHE neutrinos from relativistic jets.

  1. Dense, vertical jet in stagnant homogeneous fluid

    E-Print Network [OSTI]

    Vergara, Ignacio

    2012-06-07T23:59:59.000Z

    30. 4 53. 2 76. 0 21. 5 37. 6 53. 7 17. 5 30. 7 41. 6 3. 1 5. 4 7. 7 G. l 10. 0 15. 4 9. 2 16. 1 21. 9 0. 16 0. 28 0. 40 0. 65 1. 13 l. 62 1. 46 2. 55 3 45 H/D 50. 0 50. 0 50. 0 25. 0 25. 0 25. 0 16. 7 16, 7 16. 7...) m D 120 80 1 m D d Jet Height(from the nozzle) Abraham Jet or nozzle diameter (slope = 1. 94) Riser height H/d 0 5 r liater depth(Tank depth) (slope 1 89) L4 ft. (1. 22 m. )] s 0 pe' H/d = 0. 333 I +Turner (slope = 1. 82) ~~ ~ (slope...

  2. Azimuthal Jet Tomography at RHIC and LHC

    E-Print Network [OSTI]

    Barbara Betz; Miklos Gyulassy

    2014-02-14T23:59:59.000Z

    A generic jet-energy loss model that is coupled to state-of-the-art hydrodynamic fields and interpolates between a wide class of running coupling pQCD-based and AdS/CFT-inspired models is compared to recent data on the azimuthal and transverse momentum dependence of high-pT pion nuclear modification factors and high-pT elliptic flow measured at RHIC and LHC. We find that RHIC data are surprisingly consistent with various scenarios considered. However, extrapolations to LHC energies favor running coupling pQCD-based models of jet-energy loss. While conformal holographic models are shown to be inconsistent with data, recent non-conformal generalizations of AdS holography may provide an alternative description.

  3. Cryogenic target formation using cold gas jets

    DOE Patents [OSTI]

    Hendricks, C.D.

    1980-02-26T23:59:59.000Z

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

  4. Cryogenic target formation using cold gas jets

    DOE Patents [OSTI]

    Hendricks, Charles D. [Livermore, CA

    1980-02-26T23:59:59.000Z

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

  5. Flow control via synthetic jet actuation

    E-Print Network [OSTI]

    Miller, Adam Cole

    2005-02-17T23:59:59.000Z

    4.1 Wind Tunnel Model Showing SJA Drive Through Acrylic Access Panel ..........41 4.2 Cross Section of Trailing Edge Showing Original Plenum Design .....................41 4.3 Cross Section of Trailing Edge Showing Narrow Plenum Design.... ...........................................................48 1 1. INTRODUCTION General This thesis presents a study of the effects of flow control on a NACA0015 airfoil using Synthetic Jet Actuators (SJA) at different locations along the chord. The purpose of this research was to show...

  6. NLO QCD Predictions for W+3 jets

    SciTech Connect (OSTI)

    Maitre, Daniel; /Durham U.; Berger, Carola F.; /MIT; Bern, Zvi; Febres Cordero, Fernando; Ita, Harald; Dixon, Lance J.; Forde, Darren; Gleisberg, Tanju; /UCLA /SLAC; Kosower, David; /Saclay, SPhT

    2009-12-09T23:59:59.000Z

    In this contribution we present results from the NLO computation of the production of a W boson in association with three jets in hadronic collisions. The results are obtained by combining two programs: BlackHat for the virtual one-loop matrix elements and Sherpa for the real-emission contributions. We present results for the Tevatron and the LHC, and address the issue of the choice of a common factorization and renormalization scale for this process.

  7. ON THE ORIGIN OF INTERGRANULAR JETS

    SciTech Connect (OSTI)

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

    2011-08-01T23:59:59.000Z

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

  8. High temperature crystal structures and superionic properties of SrCl{sub 2}, SrBr{sub 2}, BaCl{sub 2} and BaBr{sub 2}

    SciTech Connect (OSTI)

    Hull, Stephen, E-mail: stephen.hull@stfc.ac.uk [The ISIS Facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Norberg, Stefan T. [The ISIS Facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg (Sweden); Ahmed, Istaq; Eriksson, Sten G. [Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg (Sweden); Mohn, Chris E. [Department of Chemistry and Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1033 Blindern, N-0315 Oslo (Norway)

    2011-11-15T23:59:59.000Z

    The structural properties of the binary alkaline-earth halides SrCl{sub 2}, SrBr{sub 2}, BaCl{sub 2} and BaBr{sub 2} have been investigated from ambient temperature up to close to their melting points, using the neutron powder diffraction technique. Fluorite-structured SrCl{sub 2} undergoes a gradual transition to a superionic phase at 900-1100 K, characterised by an increasing concentration of anion Frenkel defects. At a temperature of 920(3) K, the tetragonal phase of SrBr{sub 2} undergoes a first-order transition to a cubic fluorite phase. This high temperature phase shows the presence of extensive disorder within the anion sublattice, which differs from that found in superionic SrCl{sub 2}. BaCl{sub 2} and BaBr{sub 2} both adopt the cotunnite crystal structure under ambient conditions. BaCl{sub 2} undergoes a first-order structural transition at 917(5) K to a disordered fluorite-structured phase. The relationship between the (disordered) crystal structures and the ionic conductivity behaviour is discussed and the influence of the size of the mobile anion on the superionic behaviour is explored. - Graphical abstract: Anomalous behaviour of the lattice expansion of SrCl{sub 2} at temperatures of {approx}1000 K is associated with the gradual transition to a superionic phase, whilst SrBr{sub 2} undergoes a first-order structural transition ({beta}{yields}{alpha}) to a fluorite-structured superionic phase at 920(3) K. Highlights: > Anomalous behaviour of the lattice expansion of SrCl{sub 2} occurs at temperatures {approx}1000 K. > Crystal structure of {beta}-SrBr{sub 2} is described in detail. > On heating, SrBr{sub 2} and BaCl{sub 2} transform to a fluorite-structured superionic phase. > Temperature dependence of the BaCl{sub 2} and BaBr{sub 2} structures is presented. > Nature of the superionic phases within the alkaline-earth halides is discussed.

  9. Microwave-assisted solvothermal synthesis of flower-like Ag/AgBr/BiOBr microspheres and their high efficient photocatalytic degradation for p-nitrophenol

    SciTech Connect (OSTI)

    Li, Tingting, E-mail: tingtingli1983@hotmail.com [Department of Chemistry and Chemical Engineering, Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Changsha 410082 (China); State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082 (China); Department of Environment and Chemical Engineering, Key Laboratory of Jiangxi Province for Ecological Diagnosis, Remediation and Pollution Control, Nanchang Hangkong University, Nanchang 330063 (China); Luo, Shenglian, E-mail: sllou@hnu.edu.cn [Department of Chemistry and Chemical Engineering, Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Changsha 410082 (China); State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082 (China); Department of Environment and Chemical Engineering, Key Laboratory of Jiangxi Province for Ecological Diagnosis, Remediation and Pollution Control, Nanchang Hangkong University, Nanchang 330063 (China); Yang, Lixia [Department of Environment and Chemical Engineering, Key Laboratory of Jiangxi Province for Ecological Diagnosis, Remediation and Pollution Control, Nanchang Hangkong University, Nanchang 330063 (China)

    2013-10-15T23:59:59.000Z

    Flower-like Ag/AgBr/BiOBr microspheres were successfully fabricated by the approach of microwave-assisted solvothermal and in situ photo-assisted reduction. A reactive ionic liquid 1-hexadecyl-3-methylimidazolium bromide ([C{sub 16}mim]Br) was employed as Br source in the presence of surfactant polyvinylpyrrolidone (PVP). The photocatalytic activity of Ag/AgBr/BiOBr towards the decomposition of p-nitrophenol under visible light irradiation was evaluated. The results indicated that Ag/AgBr/BiOBr showed enhanced photocatalytic activity towards p-nitrophenol, comparing with P25, BiOBr and Ag/AgBr. More than 96% of p-nitrophenol was decomposed in 3.5 h under visible-light irradation. The excellent photocatalytic activity of flower-like Ag/AgBr/BiOBr microspheres can be attributed to the large specific surface area, strong visible-light absorption, suitable energy band structure and surface plasmon resonance effect of Ag nanoparticles. The possible photocatalytic mechanism was proposed based on the active species test and band gap structure analysis. - Graphical abstract: The photocatalytic reaction mechanisms of the as-prepared Ag/AgBr/BiOBr. Display Omitted - Highlights: • Successful synthesis of flower-like Ag/AgBr/BiOBr microspheres. • The Ag/AgBr/BiOBr showed much higher photocatalytic activity towards p-nitrophenol as compared to BiOBr and Ag/AgBr. • The reasons for the excellent photocatalytic activity are the large specific surface area, strong visible-light absorption and surface plasmon resonance effect of Ag nanoparticles. • The O{sub 2}·{sup ?}, Br{sup 0} and photogenerated h{sup +} play key roles in the photocatalytic degradation process.

  10. The impact of water flow configuration on crystallisation in LiBr/H2O absorption water heater

    SciTech Connect (OSTI)

    Wang, Kai [ORNL; Abdelaziz, Omar [ORNL; Vineyard, Edward Allan [ORNL

    2011-03-01T23:59:59.000Z

    Lithium Bromide (LiBr) strong solution entering the absorber tends to crystallise when the absorber temperature is increased for a fixed evaporating pressure. This is considered the key technical barrier for the development of a LiBr absorption heat pump water heater. There are several approaches to avoid the crystallisation problem, such as chemical crystallisation inhibitors, heat and mass transfer enhancement and thermodynamic cycle modification. This paper investigates and compares two flow configurations of LiBr absorption heat pump water heater to evaluate the allowable operating conditions for each. The simulation results indicated that introducing the process water through the absorber first results in lower absorber temperature and hence less tendency for crystallisation.

  11. Studies of Relativistic Jets in Active Galactic Nuclei with SKA

    E-Print Network [OSTI]

    Agudo, Ivan; Falcke, Heino; Georganopoulos, Markos; Ghisellini, Gabriele; Giovannini, Gabriele; Giroletti, Marcello; Gomez, Jose L; Gurvits, Leonid; Laing, Robert; Lister, Matthew; Marti, Jose-Maria; Meyer, Eileen T; Mizuno, Yosuke; O'Sullivan, Shane; Padovani, Paolo; Paragi, Zsolt; Perucho, Manel; Schleicher, Dominik; Stawarz, Lukasz; Vlahakis, Nektarios; Wardle, John

    2015-01-01T23:59:59.000Z

    Relativistic jets in active galactic nuclei (AGN) are among the most powerful astrophysical objects discovered to date. Indeed, jetted AGN studies have been considered a prominent science case for SKA, and were included in several different chapters of the previous SKA Science Book (Carilli & Rawlings 2004). Most of the fundamental questions about the physics of relativistic jets still remain unanswered, and await high-sensitivity radio instruments such as SKA to solve them. These questions will be addressed specially through analysis of the massive data sets arising from the deep, all-sky surveys (both total and polarimetric flux) from SKA1. Wide-field very-long-baseline-interferometric survey observations involving SKA1 will serve as a unique tool for distinguishing between extragalactic relativistic jets and star forming galaxies via brightness temperature measurements. Subsequent SKA1 studies of relativistic jets at different resolutions will allow for unprecedented cosmological studies of AGN jets up...

  12. Effects of Carbon Nanotube Coating on Bubble Departure Diameter and Frequency in Pool Boiling on a Flat, Horizontal Heater

    E-Print Network [OSTI]

    Glenn, Stephen T.

    2011-08-08T23:59:59.000Z

    The effects of a carbon nanotube (CNT) coating on bubble departure diameter and frequency in pool boiling experiments was investigated and compared to those on a bare silicon wafer. The pool boiling experiments were performed at liquid subcooling...

  13. Bubble nucleation on nano- to micro-size cavities and posts: An experimental validation of classical theory

    E-Print Network [OSTI]

    Phillips, B.

    Recently reported data suggest that bubble nucleation on surfaces with nano-sized features (cavities and posts) may occur close to the thermodynamic saturation temperature. However, according to the traditional theory of ...

  14. Comparison of water boiling models against recent experimental data, with special emphasis on the bubble ebullition cycle

    E-Print Network [OSTI]

    Virgen, Matthew Miguel

    2011-01-01T23:59:59.000Z

    Using recently collected data which was measured with state-of-the-art techniques, models for nucleation site density, bubble departure diameter, and nucleation frequency were compared against the acquired data. The ...

  15. State-of-the-Art Review on Crystallization Control Technologies for water/LiBr Absorption Heat Pumps

    SciTech Connect (OSTI)

    Wang, Kai [ORNL; Abdelaziz, Omar [ORNL; Kisari, Padmaja [ORNL; Vineyard, Edward Allan [ORNL

    2011-01-01T23:59:59.000Z

    The key technical barrier to using water/lithium bromide (LiBr) as the working fluid in aircooled absorption chillers and absorption heat-pump systems is the risk of crystallization when the absorber temperature rises at fixed evaporating pressure. This article reviews various crystallization control technologies available to resolve this problem: chemical inhibitors, heat and mass transfer enhancement methods, thermodynamic cycle modifications, and absorption system-control strategies. Other approaches, such as boosting absorber pressure and J-tube technology, are reviewed as well. This review can help guide future efforts to develop water/LiBr air-cooled absorption chillers and absorption heatpump systems.

  16. MEASURING THE JET POWER OF FLAT-SPECTRUM RADIO QUASARS

    SciTech Connect (OSTI)

    Shabala, S. S.; Santoso, J. S. [School of Mathematics and Physics, University of Tasmania, Private Bag 37, Hobart, TAS 7001 (Australia); Godfrey, L. E. H. [International Centre for Radio Astronomy Research, Curtin University, GPO Box U1987, Perth, Western Australia 6845 (Australia)

    2012-09-10T23:59:59.000Z

    We use frequency-dependent position shifts of flat-spectrum radio cores to estimate the kinetic power of active galactic nucleus (AGN) jets. We find a correlation between the derived jet powers and AGN narrow-line luminosity, consistent with the well-known relation for radio galaxies and steep spectrum quasars. This technique can be applied to intrinsically weak jets even at high redshift.

  17. CONTROL OF COHERENT STRUCTURE IN COAXIAL SWIRLING TURBULENT JETS

    E-Print Network [OSTI]

    Lee, Wonjoong

    2008-01-01T23:59:59.000Z

    .............................................................. 193 xvi NOMENCLATURE Symbol Description Unit D Jet diameter, Defined in Figure 5.1 m D h Hydraulic jet diameter m f Excitation frequency s -1 G Degree of swirl, Defined... stronger effect than the pilot jet itself, leading to an almost entire removal of coherent structures. 2.2. Flow Instability Swirl is naturally presented in the exhaust from a turbine or an axial flow pump, and may be deliberately generated...

  18. LiCl Dehumidifier LiBr absorption chiller hybrid air conditioning system with energy recovery

    DOE Patents [OSTI]

    Ko, Suk M. (Huntsville, AL)

    1980-01-01T23:59:59.000Z

    This invention relates to a hybrid air conditioning system that combines a solar powered LiCl dehumidifier with a LiBr absorption chiller. The desiccant dehumidifier removes the latent load by absorbing moisture from the air, and the sensible load is removed by the absorption chiller. The desiccant dehumidifier is coupled to a regenerator and the desiccant in the regenerator is heated by solar heated hot water to drive the moisture therefrom before being fed back to the dehumidifier. The heat of vaporization expended in the desiccant regenerator is recovered and used to partially preheat the driving fluid of the absorption chiller, thus substantially improving the overall COP of the hybrid system.

  19. Infrared phonon modes in multiferroic single-crystal FeTe2O5Br

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Miller, K. H.; Xu, X. S.; Berger, H.; Craciun, V.; Xi, Xiaoxiang; Martin, C.; Carr, G. L.; Tanner, D. B.

    2013-06-01T23:59:59.000Z

    Reflection and transmission as a function of temperature (7–300 K and 5–300 K respectively) have been measured on single crystals of the multiferroic compound FeTe2O5Br utilizing light spanning from the far infrared to the visible. The complex dielectric function and other optical properties were obtained via Kramers-Kronig analysis and by fits to a Drude-Lortentz model. Analysis of the anisotropic excitation spectra via Drude-Lorentz fitting and lattice dynamical calculations have led to the observation of 43 of the 53 modes predicted along the b axis of the monoclinic cell. The phonon response parallel to the a and c axes are also presented. Assignments to groups (clusters) of phonons have been made and trends within them are discussed in light of our calculated displacement patterns.

  20. ON RESPONSE CURVES OF BUBBLES THE OSCILLATIONS OF WHICH ARE DAMPED BY SOUND RADIATION Cramer, E. and Lauterborn, W.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -wall velocities beco- me comparable with the speed of sound in the liquid. The bubble model : a) Bubble. To understand (and perhaps utilize) the emission of noise in liquids irradiated by sound of high intensity+c)dt ; that is In this equation c = c(p) denotes the speed of sound in the liauid, and D/Dt = 3/9t + u3/3r is the material

  1. A correlation for the coefficient of isothermal compressibility of black oil at pressures below the bubble point

    E-Print Network [OSTI]

    Villena Lanzi, Alejandro J

    1985-01-01T23:59:59.000Z

    A CORRELATION FOR THE COEFFICIENT OF ISOTHERMAL COMPRESSIBILITY OF BLACK OIL AT PRESSURES BELOW THE BUBBLE POINT A Thesis by ALEJANDRO J. VILLENA LAiVZI Submitted to the Graduate College of Texas AAM University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE December 1985 Major Subject: Petroleum Engineerrng A CORRELATION FOR THE COEFFICIENT OF ISOTHERMAL COMPRESSIBILITY OF BLACK OIL AT PRESSURES BELOW THE BUBBLE POINT A Thesis by ALEJANDRO J. VILLENA LANZI...

  2. Tail Emission of Prompt Gamma-Ray Burst Jets

    E-Print Network [OSTI]

    Yamazaki, R; Ioka, K; Nakamura, T; Yamazaki, Ryo; Toma, Kenji; Ioka, Kunihito; Nakamura, Takashi

    2006-01-01T23:59:59.000Z

    Tail emission of the prompt gamma-ray burst is discussed using a multiple emitting sub-shell (inhomogeneous jet, sub-jets) model. The tail is a superposition of a number of smooth, long-duration, dim, and soft pulses emitted by segments located far from the line of sight. We find that the behavior of the tail is not so much affected by the local inhomogeneity but affected by the global sub-jet distribution. Some observed tails may disfavor the power-law jets.

  3. High Multiplicity Searches at the LHC Using Jet Masses

    SciTech Connect (OSTI)

    Hook, Anson; /SLAC /Stanford U., Appl. Phys. Dept.; Izaguirre, Eder; /SLAC /Stanford U., Phys. Dept.; Lisanti, Mariangela; /Princeton U.; Wacker, Jay G.; /SLAC /Stanford U., ITP

    2012-04-24T23:59:59.000Z

    This article introduces a new class of searches for physics beyond the Standard Model that improves the sensitivity to signals with high jet multiplicity. The proposed searches gain access to high multiplicity signals by reclustering events into large-radius, or 'fat', jets and by requiring that each event has multiple massive jets. This technique is applied to supersymmetric scenarios in which gluinos are pair-produced and then subsequently decay to final states with either moderate quantities of missing energy or final states without missing energy. In each of these scenarios, the use of jet mass improves the estimated reach in gluino mass by 20% to 50% over current LHC searches.

  4. An experimental study of jet impingement on a circular cylinder

    E-Print Network [OSTI]

    Potts, Dennis Wayne

    2012-06-07T23:59:59.000Z

    diameter of 6 5/8 inches. The jet was impinged upon the cylinder at nozzle distances of 7, 15, and 30 nozzle diameters, and at velocities of' 400 and 500 ft/s. The free jet was studied and found to be "typical" by comparing it to earlier studies done... Instrumentation schematic 17 5 Cylindrical suriace coordinate system 22 6 Photograph of the cylinder with "grid" 23 7 Photograph of the wall jet traversing apparatus 24 8 Orientation of the hot film sensor 25 9 Free jet geometry and parameters 30 10 Velocity...

  5. Parsec-Scale Jet-Environment Interactions in AGN

    E-Print Network [OSTI]

    Matthew L. Lister

    2007-07-12T23:59:59.000Z

    Observations made with the VLBA have led to fundamental advances in our understanding of how radio jets in AGN evolve from parsec-scales out to distances exceeding several hundred kiloparsecs. In this review I discuss current models of young radio source evolution, as well as the observational evidence for a rapid change in jet properties on scales of ~1 kpc. A central topic of current debate is the relative importance of intermittent jet fueling versus jet-environment interactions in causing a drop-off in powerful radio sources at this critical evolutionary stage. Recent 3-D hydrodynamical jet simulations suggest that dense environments and cloud collisions can temporarily stifle, but not completely halt powerful relativistic jets. Several VLBA studies of jet-ISM interactions in both blazars and weak Seyfert jets have indicated that collimated outflows are indeed possible in dense environments. At present, the bulk of the evidence favors intermittent AGN accretion as the dominant factor in determining the evolutionary path of large numbers of AGN jets.

  6. Infrared imaging results of an excited planar jet

    SciTech Connect (OSTI)

    Farrington, R.B.

    1991-12-01T23:59:59.000Z

    Planar jets are used for many applications including heating, cooling, and ventilation. Generally such a jet is designed to provide good mixing within an enclosure. In building applications, the jet provides both thermal comfort and adequate indoor air quality. Increased mixing rates may lead to lower short-circuiting of conditioned air, elimination of dead zones within the occupied zone, reduced energy costs, increased occupant comfort, and higher indoor air quality. This paper discusses using an infrared imaging system to show the effect of excitation of a jet on the spread angle and on the jet mixing efficiency. Infrared imaging captures a large number of data points in real time (over 50,000 data points per image) providing significant advantages over single-point measurements. We used a screen mesh with a time constant of approximately 0.3 seconds as a target for the infrared camera to detect temperature variations in the jet. The infrared images show increased jet spread due to excitation of the jet. Digital data reduction and analysis show change in jet isotherms and quantify the increased mixing caused by excitation. 17 refs., 20 figs.

  7. Environmental and economic assessment of microalgae-derived jet fuel

    E-Print Network [OSTI]

    Carter, Nicholas Aaron

    2012-01-01T23:59:59.000Z

    Significant efforts must be undertaken to quantitatively assess various alternative jet fuel pathways when working towards achieving environmental and economic United States commercial and military alternative aviation ...

  8. Inclusive-jet photoproduction at HERA and determination of alphas

    E-Print Network [OSTI]

    ZEUS Collaboration; H. Abramowicz; I. Abt; L. Adamczyk; M. Adamus; R. Aggarwal; S. Antonelli; P. Antonioli; A. Antonov; M. Arneodo; V. Aushev; Y. Aushev; O. Bachynska; A. Bamberger; A. N. Barakbaev; G. Barbagli; G. Bari; F. Barreiro; N. Bartosik; D. Bartsch; M. Basile; O. Behnke; J. Behr; U. Behrens; L. Bellagamba; A. Bertolin; S. Bhadra; M. Bindi; C. Blohm; V. Bokhonov; T. Bold; K. Bondarenko; E. G. Boos; K. Borras; D. Boscherini; D. Bot; I. Brock; E. Brownson; R. Brugnera; N. Brummer; A. Bruni; G. Bruni; B. Brzozowska; P. J. Bussey; B. Bylsma; A. Caldwell; M. Capua; R. Carlin; C. D. Catterall; S. Chekanov; J. Chwastowski; J. Ciborowski; R. Ciesielski; L. Cifarelli; F. Cindolo; A. Contin; A. M. Cooper-Sarkar; N. Coppola; M. Corradi; F. Corriveau; M. Costa; G. D'Agostini; F. Dal Corso; J. del Peso; R. K. Dementiev; S. De Pasquale; M. Derrick; R. C. E. Devenish; D. Dobur; B. A. Dolgoshein; G. Dolinska; A. T. Doyle; V. Drugakov; L. S. Durkin; S. Dusini; Y. Eisenberg; P. F. Ermolov; A. Eskreys; S. Fang; S. Fazio; J. Ferrando; M. I. Ferrero; J. Figiel; M. Forrest; B. Foster; G. Gach; A. Galas; E. Gallo; A. Garfagnini; A. Geiser; I. Gialas; A. Gizhko; L. K. Gladilin; D. Gladkov; C. Glasman; O. Gogota; Yu. A. Golubkov; P. Gottlicher; I. Grabowska-Bold; J. Grebenyuk; I. Gregor; G. Grigorescu; G. Grzelak; O. Gueta; M. Guzik; C. Gwenlan; T. Haas; W. Hain; R. Hamatsu; J. C. Hart; H. Hartmann; G. Hartner; E. Hilger; D. Hochman; R. Hori; K. Horton; A. Huttmann; Z. A. Ibrahim; Y. Iga; R. Ingbir; M. Ishitsuka; H. -P. Jakob; F. Januschek; T. W. Jones; M. Jungst; I. Kadenko; B. Kahle; S. Kananov; T. Kanno; U. Karshon; F. Karstens; I. I. Katkov; M. Kaur; P. Kaur; A. Keramidas; L. A. Khein; J. Y. Kim; D. Kisielewska; S. Kitamura; R. Klanner; U. Klein; E. Koffeman; N. Kondrashova; O. Kononeko; P. Kooijman; Ie. Korol; I. A. Korzhavina; A. Kotanski; U. Kotz; H. Kowalski; O. Kuprash; M. Kuze; A. Lee; B. B. Levchenko; A. Levy; V. Libov; S. Limentani; T. Y. Ling; M. Lisovyi; E. Lobodzinska; W. Lohmann; B. Lohr; E. Lohrmann; K. R. Long; A. Longhin; D. Lontkovskyi; O. Yu. Lukina; J. Maeda; S. Magill; I. Makarenko; J. Malka; R. Mankel; A. Margotti; G. Marini; J. F. Martin; A. Mastroberardino; M. C. K. Mattingly; I. -A. Melzer-Pellmann; S. Mergelmeyer; S. Miglioranzi; F. Mohamad Idris; V. Monaco; A. Montanari; J. D. Morris; K. Mujkic; B. Musgrave; K. Nagano; T. Namsoo; R. Nania; A. Nigro; Y. Ning; T. Nobe; U. Noor; D. Notz; R. J. Nowak; A. E. Nuncio-Quiroz; B. Y. Oh; N. Okazaki; K. Oliver; K. Olkiewicz; Yu. Onishchuk; K. Papageorgiu; A. Parenti; E. Paul; J. M. Pawlak; B. Pawlik; P. G. Pelfer; A. Pellegrino; W. Perlanski; H. Perrey; K. Piotrzkowski; P. Plucinski; N. S. Pokrovskiy; A. Polini; A. S. Proskuryakov; M. Przybycien; A. Raval; D. D. Reeder; B. Reisert; Z. Ren; J. Repond; Y. D. Ri; A. Robertson; P. Roloff; I. Rubinsky; M. Ruspa; R. Sacchi; U. Samson; G. Sartorelli; A. A. Savin; D. H. Saxon; M. Schioppa; S. Schlenstedt; P. Schleper; W. B. Schmidke; U. Schneekloth; V. Schonberg; T. Schorner-Sadenius; J. Schwartz; F. Sciulli; L. M. Shcheglova; R. Shehzadi; S. Shimizu; I. Singh; I. O. Skillicorn; W. Slominski; W. H. Smith; V. Sola; A. Solano; D. Son; V. Sosnovtsev; A. Spiridonov; H. Stadie; L. Stanco; N. Stefaniuk; A. Stern; T. P. Stewart; A. Stifutkin; P. Stopa; S. Suchkov; G. Susinno; L. Suszycki; J. Sztuk-Dambietz; D. Szuba; J. Szuba; A. D. Tapper; E. Tassi; J. Terron; T. Theedt; H. Tiecke; K. Tokushuku; J. Tomaszewska; V. Trusov; T. Tsurugai; M. Turcato; O. Turkot; T. Tymieniecka; M. Vazquez; A. Verbytskyi; O. Viazlo; N. N. Vlasov; R. Walczak; W. A. T. Wan Abdullah; J. J. Whitmore; L. Wiggers; M. Wing; M. Wlasenko; G. Wolf; H. Wolfe; K. Wrona; A. G. Yagues-Molina; S. Yamada; Y. Yamazaki; R. Yoshida; C. Youngman; O. Zabiegalov; A. F. Zarnecki; L. Zawiejski; O. Zenaiev; W. Zeuner; B. O. Zhautykov; N. Zhmak; C. Zhou; A. Zichichi; Z. Zolkapli; D. S. Zotkin

    2012-05-28T23:59:59.000Z

    Inclusive-jet cross sections have been measured in the reaction ep->e+jet+X for photon virtuality Q2 energies in the region 142 energy, ETjet, and pseudorapidity, etajet, for jets with ETjet > 17 GeV and -1 energy-scale dependence of the coupling was determined. The value of alphas(Mz) extracted from the measurements based on the kT jet algorithm is alphas(Mz) = 0.1206 +0.0023 -0.0022 (exp.) +0.0042 -0.0035 (th.); the results from the anti-kT and SIScone algorithms are compatible with this value and have a similar precision.

  9. Microhole Arrays Drilled With Advanced Abrasive Slurry Jet Technology...

    Open Energy Info (EERE)

    Arrays Drilled With Advanced Abrasive Slurry Jet Technology To Efficiently Exploit Enhanced Geothermal Systems Geothermal Project Jump to: navigation, search Last modified on July...

  10. An alternative model of jet suppression at RHIC energies

    E-Print Network [OSTI]

    Roman Lietava; Jan Pisut; Neva Pisutova; Boris Tomasik

    2003-02-10T23:59:59.000Z

    We propose a simple Glauber-type mechanism for suppression of jet production up to transverse momenta of about 10 GeV/c at RHIC. For processes in this kinematic region, the formation time is smaller than the interval between two successive hard partonic collisions and the subsequent collision influences the jet production. Number of jets then roughly scales with the number of participants. Proportionality to the number of binary collisions is recovered for very high transverse momenta. The model predicts suppression of jet production in d+Au collisions at RHIC.

  11. Geographic Area Month Aviation Gasoline Kerosene-Type Jet Fuel

    Gasoline and Diesel Fuel Update (EIA)

    State (Cents per Gallon Excluding Taxes) - Continued Geographic Area Month Aviation Gasoline Kerosene-Type Jet Fuel Kerosene Sales to End Users Sales for Resale Sales to End...

  12. COLLIMATION AND CONFINEMENT OF MAGNETIC JETS BY EXTERNAL MEDIA

    SciTech Connect (OSTI)

    Levinson, Amir [School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel)] [School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel); Begelman, Mitchell C., E-mail: Levinson@wise.tau.ac.il, E-mail: mitch@jila.colorado.edu [JILA, University of Colorado and National Institute of Standards and Technology, 440 UCB, Boulder, CO 80309-0440 (United States)

    2013-02-20T23:59:59.000Z

    We study the collimation of a highly magnetized jet by a surrounding cocoon that forms as a result of the interaction of the jet with the external medium. We show that in regions where the jet is well confined by the cocoon, current-driven instabilities should develop over timescales shorter than the expansion time of the jet's head. We speculate that these instabilities would give rise to complete magnetic field destruction, whereby the jet undergoes a transition from high to low sigma above the collimation zone. Using this assumption, we construct a self-consistent model for the evolution of the jet-cocoon system in an ambient medium of arbitrary density profile. We apply the model to jet breakout in long gamma-ray bursts (GRBs) and show that the jet is highly collimated inside the envelope of the progenitor star and is likely to remain confined well after breakout. We speculate that this strong confinement may provide a channel for magnetic field conversion in GRB outflows, whereby the hot, low-sigma jet section thereby produced is the source of the photospheric emission observed in many bursts.

  13. asian jet stream: Topics by E-print Network

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

    Laboratory Kidston, Joseph 11 Rayleigh Wave-Internal Wave Coupling and Internal Wave Generation Above a Model Jet Stream Mathematics Websites Summary: Rayleigh...

  14. Measurement of b-quark Jet Shapes at CDF

    SciTech Connect (OSTI)

    Lister, Alison; /Zurich, ETH

    2006-03-01T23:59:59.000Z

    The main topic of this thesis is the measurement of b-quark jet shapes at CDF. CDF is an experiment located at Fermilab, in the United States, which studies proton-antiproton collisions at a center of mass energy of 1.96TeV. To reach this energy, the particles are accelerated using the Tevatron accelerator which is currently the highest energy collider in operation. The data used for this analysis were taken between February 2002 and September 2004 and represent an integrated luminosity of about 300 pb{sup -1}. This is the first time that b-quark jet shapes have been measured at hadron colliders. The basis of this measurement lies in the possibility of enhancing the b-quark jet content of jet samples by requiring the jets to be identified as having a displaced vertex inside the jet cone. Such jets are called tagged. This enhances the b-quark jet fraction from about 5% before tagging to 20-40% after tagging, depending on the transverse momentum of the jets. I verified that it is possible to apply this secondary vertex tagging algorithm to different cone jet algorithms (MidPoint and JetClu) and different cone sizes (0.4 and 0.7). I found that the performance of the algorithm does not change significantly, as long as the sub-cone inside which tracks are considered for the tagging is kept at the default value of 0.4. Because the b-quark purity of the jets is still relatively low, it is necessary to extract the shapes of b-quark jets in a statistical manner from the jet shapes both before and after tagging. The other parameters that enter into the unfolding equation used to extract the b-quark jet shapes are the b-jet purities, the biases due to the tagging requirement both for b- and nonbjets and the hadron level corrections. The last of these terms corrects the measured b-jet shapes back to the shapes expected at hadron level which makes comparisons with theoretical models and other experimental results possible. This measurement shows that, despite relatively large systematic uncertainties, the measured b-quark jet shapes are significantly different from those expected from the so-called Pythia Tune A Monte Carlo simulation, the most widely used Leading Order Monte Carlo model at CDF. This difference can be mostly attributed to the fact that the fraction of b-quark jets that originate from flavour creation (where a single b-quark is expected inside the same jet cone) over those that originate from gluon splitting (where two b-quarks are expected to be inside the same jet cone) is slightly different in the Pythia Tune A Monte Carlo predictions than in data. This measurement can help in the tuning of the fraction of gluon splitting to flavour creation b-quark jets in the Monte Carlo simulation. This tuning is particularly important for the extrapolation up to LHC energies where many searches will involve b-quark jets. During the first year of my thesis work, I worked on the implementation of a prototype detector control system for the electromagnetic calorimeter which is being built for the CMS experiment at CERN. The prototype which I implemented was used to monitor and control the high voltage, low voltage, cooling and precision temperature monitoring systems during the summer 2003 test-beam. This was one of the first, almost complete, systems implemented and used by an LHC experiment for test-beam monitoring.

  15. Atomistic studies of formation and diffusion of helium clusters and bubbles in BCC iron

    SciTech Connect (OSTI)

    Stewart, David M [ORNL; Stoller, Roger E [ORNL; Osetskiy, Yury N [ORNL

    2011-01-01T23:59:59.000Z

    In fusion applications, helium created by transmutation plays an important role in the response of reduced-activation ferritic/martensitic (RAFM) steels to neutron radiation damage. We have performed extensive atomistic simulations using the ORNL 3-body Fe He interatomic potential combined with three interatomic potentials for the iron matrix. Some of the results obtained are summarized in this review. Interstitial helium is very mobile and coalesces together to form interstitial clusters. We have investigated the mobility of these clusters. When an interstitial He cluster reaches sufficient size, it punches out an Fe interstitial, creating an immobile helium vacancy cluster. If more helium atoms join it, more Fe interstitials can be created; the He V defect is a nascent bubble. These mechanisms are investigated together in simulations that examine the nucleation of He defects. Mobile interstitial He clusters and helium bubbles 1 to 6 nm across are also simulated separately. Results are compared based on temperature and interatomic potentials used.

  16. Numerical investigation of electron self-injection in the nonlinear bubble regime

    SciTech Connect (OSTI)

    Benedetti, C.; Schroeder, C. B.; Esarey, E.; Leemans, W. P. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Rossi, F. [Department of Physics and Astronomy, University of Bologna and INFN, Via Irnerio 46, 40126 Bologna (Italy)] [Department of Physics and Astronomy, University of Bologna and INFN, Via Irnerio 46, 40126 Bologna (Italy)

    2013-10-15T23:59:59.000Z

    The process of electron self-injection in the nonlinear bubble wake generated by a short and intense laser pulse propagating in a uniform underdense plasma is studied by means of fully self-consistent particle-in-cell simulations and test-particle simulations. We consider a wake generated by a non-evolving laser driver traveling with a prescribed velocity, which then sets the structure and the velocity of the wake, so the injection dynamics is decoupled from driver evolution, but a realistic structure for the wakefield is retained. We show that a threshold for self-injection into a non-evolving bubble wake exists, and we characterize the dependence of the self-injection threshold on laser intensity, wake velocity, and plasma temperature for a range of parameters of interest for current and future laser-plasma accelerators.

  17. Metal wastage design guidelines for bubbling fluidized-bed combustors. Final report

    SciTech Connect (OSTI)

    Lyczkowski, R.W.; Podolski, W.F.; Bouillard, J.X.; Folga, S.M. [Argonne National Lab., IL (United States)

    1992-11-01T23:59:59.000Z

    These metal wastage design guidelines identify relationships between metal wastage and (1) design parameters (such as tube size, tube spacing and pitch, tube bundle and fluidized-bed height to distributor, and heat exchanger tube material properties) and (2) operating parameters (such as fluidizing velocity, particle size, particle hardness, and angularity). The guidelines are of both a quantitative and qualitative nature. Simplified mechanistic models are described, which account for the essential hydrodynamics and metal wastage processes occurring in bubbling fluidized beds. The empirical correlational approach complements the use of these models in the development of these design guidelines. Data used for model and guideline validation are summarized and referenced. Sample calculations and recommended design procedures are included. The influences of dependent variables on metal wastage, such as solids velocity, bubble size, and in-bed pressure fluctuations, are discussed.

  18. Synthesis, crystal structure, spectroscopic and thermal properties of [Et{sub 4}N][Ta{sub 6}Br{sub 12}(H{sub 2}O){sub 6}]Br{sub 4}.4H{sub 2}O (Et=ethyl)-A new compound with the paramagnetic [Ta{sub 6}Br{sub 12}]{sup 3+} cluster core

    SciTech Connect (OSTI)

    Peric, Berislav, E-mail: bperic@irb.h [Ruder Boskovic Institute, Bijenicka cesta 54, 10000 Zagreb (Croatia); Jozic, Drazan [Ruder Boskovic Institute, Bijenicka cesta 54, 10000 Zagreb (Croatia); Planinic, Pavica, E-mail: planinic@irb.h [Ruder Boskovic Institute, Bijenicka cesta 54, 10000 Zagreb (Croatia); Brnicevic, Nevenka [Ruder Boskovic Institute, Bijenicka cesta 54, 10000 Zagreb (Croatia); Giester, Gerald [Institut fuer Mineralogie und Kristallographie, Universitaet Wien-Geozentrum Althanstrasse, 14, 1090 Wien (Austria)

    2009-09-15T23:59:59.000Z

    A new hexanuclear cluster compound, [Et{sub 4}N][Ta{sub 6}Br{sub 12}(H{sub 2}O){sub 6}]Br{sub 4}.4H{sub 2}O (Et=ethyl) (1), with the paramagnetic [Ta{sub 6}Br{sub 12}]{sup 3+} cluster entity, was synthesized and characterized by elemental and TG/DTA analyses, IR and UV/Vis spectroscopy and by a single-crystal X-ray diffraction study. The presence of the paramagnetic [Ta{sub 6}Br{sub 12}]{sup 3+} unit was confirmed also by the room-temperature magnetic and EPR measurements. The compound crystallizes in the tetragonal I4{sub 1}/a space group, with a=14.299(5), c=21.241(5) A, Z=4, R{sub 1}(F)/wR{sub 2}(F{sup 2})=0.0296/0.0811. The structure contains discrete [Ta{sub 6}Br{sub 12}(H{sub 2}O){sub 6}]{sup 3+} cations with an octahedron of metal atoms edge-bridged by bromine atoms and with water molecules occupying all six terminal positions. The cluster units are positioned in the vertices of the three-dimensional (pseudo)diamond lattice. The structure shows similarities with literature reported structures of cluster compounds crystallizing in the diamond (Fd3-barm) space group. - Graphical abstract: Two interpenetrating (pseudo)diamond nets formed by packing of the paramagnetic [Ta{sub 6}Br{sub 12}(H{sub 2}O)]{sup 3+} (octahedral) and diamagnetic [Et{sub 4}N]{sup +} (spheres) cations.

  19. Experimental and theoretical investigation on the mechanism of transient bubble images in fluidized-bed combustors: Systematic interpretation and analysis. Final report, July 1992--July 1995

    SciTech Connect (OSTI)

    Hisashi O. Kono

    1995-08-01T23:59:59.000Z

    For the improvement of the design and operation of the FBC systems, the insight into the intrinsic transient bubbling phenomena in freely bubbling fluidized beds is of vital importance. The authors have found several basic new bubbling mechanisms in this work experimentally, and some of them have not been published in past literature. Using the two dimensional fluidized bed, the images of transient bubbling behavior were recorded by videos, and processed and analyzed by computers. As the results of experiments, the following new experimental facts were found: (1) transient bubbles change and fluctuate their size and shape over very short time intervals (on the order of 30 milliseconds); (2) bubble disappearance and reappearance occurred in the emulsion phase in addition to the known phenomena of coalescence and splitting. The bubble interaction occurred between the bubbles and adjacent emulsion phase and also among the transient bubbles; (3) bubble`s velocity fluctuated significantly, e.g., 0.6 to 3.0 m/s; (4) under one single specific fluidization condition, two different fluidization patterns appeared to occur randomly shifting from one pattern to the other or vice versa; (5) the erosion rates of in-bed tubes at ambient and elevated temperature could be predicted using material property data and transient behavior of bubbles. By introducing a new quantitative criterion which the authors call a gas stress index in the emulsion phase, the comparison of the fluidization quality between two and three dimensional fluidized beds was accomplished. They found reasonable correspondence between the two beds, and concluded that the new findings of transient bubble behavior should hold true for both types of fluidized beds. 32 refs., 85 figs., 13 tabs.

  20. Gas Bubbles and Gas Pancakes at Liquid/Solid Interface: A Continuum Theory Incorporated with Molecular Interactions

    E-Print Network [OSTI]

    Zhaoxia Li; Xuehua Zhang; Lijuan Zhang; Xiaocheng Zeng; Jun Hu; Haiping Fang

    2007-10-27T23:59:59.000Z

    The states of gas accumulated at the liquid-solid interface are analyzed based on the continuum theory where the Hamaker constant is used to describe the long-range interaction at the microscopic scale. The Hamaker constant is always negative, whereas the gas spreading coefficient can be either sign. Despite the complexity of gas, including that the density profile may not be uniform due to absorption on both solid and liquid surfaces, we predict three possible gas states at the liquid-solid interface, i.e. complete wetting, partial wetting and pseudopartial wetting. These possible gas states correspond respectively to a gas pancake (or film) surrounded by a wet solid, a gas bubble with a finite contact angle, and a gas bubble(s) coexisting with a gas pancake. Typical thickness of the gas pancakes is at the nanoscale within the force range of the long-range interaction, whereas the radius of the gas bubbles can be large. The state of gas bubble(s) coexisting with a gas film is predicted theoretically for the first time. Our theoretical results can contribute to the development of a unified picture of gas nucleation at the liquid-solid interface.

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

    DOE Patents [OSTI]

    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

    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.

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

    DOE Patents [OSTI]

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

    1999-08-17T23:59:59.000Z

    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.

  3. Transport of entrained air bubbles in fresh concrete due to pressure variations

    E-Print Network [OSTI]

    Macha, Ravi Kumar

    1993-01-01T23:59:59.000Z

    Alkali (Soluble) on Air Entrainment in Concrete [22]. 31 Figure 11. Figure 12. Effect of Cement Fineness on Air Content of Fresh Concrete [22]. Change in Void Size Distribution on Vibration of Air Entrained Concrete [17]. 32 33 Figure 13. Effect.... Reduction in Water and Sand Contents Made Possible by Various Percentages of Entrained Air Content [21]. 38 Page Figure 16. Relationship of Solubility of Air and Internal Pressure to the Size of an Air Bubble in water at 20 C [14...

  4. Measurement of bubble sizes in fluidised beds using electrical capacitance tomography

    E-Print Network [OSTI]

    Chandrasekera, T. C.; Li, Y.; Moody, D.; Schnellmann, M. A.; Dennis, J. S.; Holland, D. J.

    2015-01-13T23:59:59.000Z

    -mail address: djh79@cam.ac.uk (D.J. Holland). 1 Now at the Ocean Science & Technology Division, Graduate School at Shenzhen, Tsinghua University, China. 2 Now at the Department of Chemical and Process Engineering, University of Canterbury, Christchurch, New... Measurement of bubble sizes in fluidised beds using electrical capacitance tomography T.C. Chandrasekera, Y. Li 1, D. Moody, M.A. Schnellmann, J.S. Dennis, D.J. Holland n,2 Department of Chemical Engineering and Biotechnology, University...

  5. DEEP CHANDRA OBSERVATIONS OF EDGES AND BUBBLES IN THE NGC 5846 GALAXY GROUP

    SciTech Connect (OSTI)

    Machacek, Marie E.; Jerius, Diab; Kraft, Ralph; Forman, William R.; Jones, Christine; Randall, Scott [Harvard-Smithsonian Center for Astrophysics 60 Garden Street, Cambridge, MA 02138 (United States); Giacintucci, Simona [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Sun Ming, E-mail: mmachacek@cfa.harvard.edu [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22901 (United States)

    2011-12-10T23:59:59.000Z

    We use a combined 120 ks Chandra exposure to analyze X-ray edges produced by non-hydrostatic gas motions (sloshing) from galaxy collisions, and cavities formed by active galactic nucleus (AGN) activity. Evidence for gas sloshing is seen in the spiral morphology and multiple cold front edges in NGC 5846's X-ray surface brightness distribution, while the lack of spiral structure in the temperature map suggests that the perturbing interaction was not in the plane of the sky. Density and spectral modeling across the edges indicate that the relative motion of gas in the cold fronts is at most transonic. Evidence for AGN activity is seen in two inner bubbles at 0.6 kpc, filled with 5 GHz and 1.5 GHz radio plasma and coincident with H{alpha} emission, and in a ghost bubble at 5.2 kpc west of NGC 5846's nucleus. The outburst energy and ages for the inner (ghost) bubbles are {approx}10{sup 55} erg and {approx}2 Myr ({approx}5 Multiplication-Sign 10{sup 55} erg and 12 Myr), respectively, implying an AGN duty cycle of 10 Myr. The inner bubble rims are threaded with nine knots, whose total 0.5-2 keV X-ray luminosity is 0.3 Multiplication-Sign 10{sup 40} erg s{sup -1}, a factor {approx}2-3 less than that of the surrounding rims, and 0.7 keV mean temperature is indistinguishable from that of the rims. We suggest that the knots may be transient clouds heated by the recent passage of a shock from the last AGN outburst. We also observe gas stripping from a cE galaxy, NGC 5846A, in a 0.5 kpc long ({approx}10{sup 5} M{sub Sun }) hot gas tail, as it falls toward NGC 5846.

  6. Generation and Propagation of Inertia Gravity Waves from Vortex Dipoles and Jets Shuguang Wang

    E-Print Network [OSTI]

    Generation and Propagation of Inertia Gravity Waves from Vortex Dipoles and Jets Shuguang Wang generation and propagation from jets within idealized vortex dipoles using a nonhydrostatic mesoscale model, moist convection, fronts, upper level jets, geostrophic adjustment and spontaneous generation (Fritts

  7. Nodal effects in a-iron dislocation mobility in the presence of helium bubbles

    SciTech Connect (OSTI)

    Kumar, N. Naveen; Martinez, E; Dutta, B. K.; Dey, G. K.; Caro, J. A.

    2013-01-01T23:59:59.000Z

    Dislocations and dislocation networks act as sinks for irradiation-induced point defects such as vacancies and interstitials, or impurities such as helium. Recently, it has been found that the intersection points of the screw dislocation network formed at twist grain boundaries in Au (experimental) and Cu (simulations) act as nucleation sites for He bubbles, which form an array at the interface [ J. Hetherly, E. Martinez, Z. F. Di, M. Nastasi and A. Caro Scr. Mater. 66 17 (2012)]. The modeling part of that study was based on Monte Carlo algorithms. Here, using molecular dynamics simulations, we have performed shear deformation simulations of small-angle twist grain boundaries in ?-iron. We report on the mechanical properties of this interface in pure as well as He-segregated samples. We find that this particular dislocation array in pure Fe is extremely mobile, with a Peierls stress ten times smaller than the value for a single straight screw dislocation, and that He bubbles induce a colossal increase (>50 times) in Peierls stress with respect to the pristine network. We interpret the results in terms of preexisting kinks and no shear transmission across the He bubbles.

  8. Comparison Between Numerical and Experimental Results on Mechanical Stirrer and Bubbling in a Cylindrical Tank - 13047

    SciTech Connect (OSTI)

    Lima da Silva, M.; Sauvage, E.; Brun, P. [CEA-Marcoule, BP 17171, 30207 Bagnols sur Ceze (France)] [CEA-Marcoule, BP 17171, 30207 Bagnols sur Ceze (France); Gagnoud, A.; Fautrelle, Y. [SIMaP, Grenoble INP, UJF, CNRS, BP 75, 38402 Saint Martin D'Heres (France)] [SIMaP, Grenoble INP, UJF, CNRS, BP 75, 38402 Saint Martin D'Heres (France); Riva, R. [CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble (France)] [CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble (France)

    2013-07-01T23:59:59.000Z

    The process of vitrification in a cold crucible heated by direct induction is used in the fusion of oxides. Its feature is the production of high-purity materials. The high-level of purity of the molten is achieved because this melting technique excludes the contamination of the charge by the crucible. The aim of the present paper is to analyze the hydrodynamic of the vitrification process by direct induction, with the focus in the effects associated with the interaction between the mechanical stirrer and bubbling. Considering the complexity of the analyzed system and the goal of the present work, we simplified the system by not taking into account the thermal and electromagnetic phenomena. Based in the concept of hydraulic similitude, we performed an experimental study and a numerical modeling of the simplified model. The results of these two studies were compared and showed a good agreement. The results presented in this paper in conjunction with the previous work contribute to a better understanding of the hydrodynamics effects resulting from the interaction between the mechanical stirrer and air bubbling in the cold crucible heated by direct induction. Further works will take into account thermal and electromagnetic phenomena in the presence of mechanical stirrer and air bubbling. (authors)

  9. Core-to-valence spectroscopic detection of the CH{sub 2}Br radical and element-specific femtosecond photodissociation dynamics of CH{sub 2}IBr

    SciTech Connect (OSTI)

    Attar, Andrew R.; Piticco, Lorena [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Leone, Stephen R. [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Physics, University of California, Berkeley, California 94720 (United States)

    2014-10-28T23:59:59.000Z

    Element-specific single photon photodissociation dynamics of CH{sub 2}IBr and core-to-valence absorption spectroscopy of CH{sub 2}Br radicals are investigated using femtosecond high-harmonic extreme ultraviolet (XUV) transient absorption spectroscopy. Photodissociation of CH{sub 2}IBr along both the C–I or C–Br reaction coordinates is observed in real-time following excitation at 266 nm. At this wavelength, C–I dissociation is the dominant reaction channel and C–Br dissociation is observed as a minor pathway. Both photodissociation pathways are probed simultaneously through individual 4d(I) N{sub 4/5} and 3d(Br) M{sub 4/5} core-to-valence transitions. The 3d(Br) M{sub 4/5} pre-edge absorption spectrum of the CH{sub 2}Br radical photoproduct corresponding to the C–I dissociation channel is characterized for the first time. Although the radical's singly occupied molecular orbital (SOMO) is mostly localized on the central carbon atom, the 3d(Br) ? ?{sup *}(SOMO) resonances at 68.5 eV and 69.5 eV are detected 2 eV below the parent molecule 3d(Br) ? ?{sup *}(LUMO) transitions. Core-to-valence XUV absorption spectroscopy provides a unique probe of the local electronic structure of the radical species in reference to the Br reporter atom. The measured times for C–I dissociation leading to I and I{sup *} atomic products are 48 ± 12 fs and 44 ± 4 fs, respectively, while the measured C–Br dissociation time leading to atomic Br is 114 ± 17 fs. The investigation performed here demonstrates the capability of femtosecond time-resolved core-level spectroscopy utilizing multiple reporter atoms simultaneously.

  10. PowerJet Wind Turbine Project

    SciTech Connect (OSTI)

    Bartlett, Raymond J

    2008-11-30T23:59:59.000Z

    PROJECT OBJECTIVE The PowerJet wind turbine overcomes problems characteristic of the small wind turbines that are on the market today by providing reliable output at a wide range of wind speeds, durability, silent operation at all wind speeds, and bird-safe operation. Prime Energy�s objective for this project was to design and integrate a generator with an electrical controller and mechanical controls to maximize the generation of electricity by its wind turbine. The scope of this project was to design, construct and test a mechanical back plate to control rotational speed in high winds, and an electronic controller to maximize power output and to assist the base plate in controlling rotational speed in high winds. The test model will continue to operate beyond the time frame of the project, with the ultimate goal of manufacturing and marketing the PowerJet worldwide. Increased Understanding of Electronic & Mechanical Controls Integrated With Electricity Generator The PowerJet back plate begins to open as wind speed exceeds 13.5 mps. The pressure inside the turbine and the turbine rotational speed are held constant. Once the back plate has fully opened at approximately 29 mps, the controller begins pulsing back to the generator to limit the rotational speed of the turbine. At a wind speed in excess of 29 mps, the controller shorts the generator and brings the turbine to a complete stop. As the wind speed subsides, the controller releases the turbine and it resumes producing electricity. Data collection and instrumentation problems prevented identification of the exact speeds at which these events occur. However, the turbine, controller and generator survived winds in excess of 36 mps, confirming that the two over-speed controls accomplished their purpose. Technical Effectiveness & Economic Feasibility Maximum Electrical Output The output of electricity is maximized by the integration of an electronic controller and mechanical over-speed controls designed and tested during the course of this project. The output exceeds that of the PowerJet�s 3-bladed counterparts (see Appendix). Durability All components of the PowerJet turbine assembly�including the electronic and mechanical controls designed, manufactured and field tested during the course of this project�proved to be durable through severe weather conditions, with constant operation and no interruption in energy production. Low Cost Materials for the turbine, generator, tower, charge controllers and ancillary parts are available at reasonable prices. Fabrication of these parts is also readily available worldwide. The cost of assembling and installing the turbine is reduced because it has fewer parts and requires less labor to manufacture and assemble, making it competitively priced compared with turbines of similar output manufactured in the U.S. and Europe. The electronic controller is the unique part to be included in the turbine package. The controllers can be manufactured in reasonably-sized production runs to keep the cost below $250 each. The data logger and 24 sensors are for research only and will be unnecessary for the commercial product. Benefit To Public The PowerJet wind-electric system is designed for distributed wind generation in 3 and 4 class winds. This wind turbine meets DOE�s requirements for a quiet, durable, bird-safe turbine that eventually can be deployed as a grid-connected generator in urban and suburban settings. Results As described more fully below and illustrated in the Appendices, the goals and objectives outlined in 2060 SOPO were fully met. Electronic and mechanical controls were successfully designed, manufactured and integrated with the generator. The turbine, tower, controllers and generators operated without incident throughout the test period, surviving severe winter and summer weather conditions such as extreme temperatures, ice and sustained high winds. The electronic controls were contained in weather-proof electrical boxes and the elec

  11. HPHC COL-06-MA-BR-2010 20-1649-2 Coverage underwritten by HPHC Insurance Company, Inc., an affiliate

    E-Print Network [OSTI]

    Mountziaris, T. J.

    HPHC COL-06-MA-BR-2010 20-1649-2 Coverage underwritten by HPHC Insurance Company, Inc;#12;Welcome to the Harvard Pilgrim Student Health Plan. Your Plan is offered by HPHC Insurance Company at www.uhcsr.com. The web site will allow you to easily search for providers by specialty and location

  12. Appointed BrOadcast (ABO): Reducing Routing Overhead in IEEE 802.11 Mobile Ad Hoc Networks

    E-Print Network [OSTI]

    Chen, Sheng-Wei

    1 Appointed BrOadcast (ABO): Reducing Routing Overhead in IEEE 802.11 Mobile Ad Hoc Networks Chun-enhanced and standard IEEE 802.11 nodes can coexist in a MANET is also discussed. Keywords: mobile ad hoc network, promiscuous mode, broadcast, IEEE 802.11, routing. #12;2 1. Introduction In mobile ad hoc networks (MANETs

  13. E-Print Network 3.0 - annular two-phase jet Sample Search Results

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

    and Annular Structures in Geophysical FluidsJets and Annular Structures in Geophysical Fluids Summary: Chapman Conference onChapman Conference on Jets and Annular Structures in...

  14. E-Print Network 3.0 - atmospheric-pressure plasma jet Sample...

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

    Databases and Resources 3 Atmospheric Pressure Plasma Jet Treatment of Polyethylene Surfaces for Summary: Atmospheric Pressure Plasma Jet Treatment of Polyethylene...

  15. E-Print Network 3.0 - abrasive water jet Sample Search Results

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

    water jet Search Powered by Explorit Topic List Advanced Search Sample search results for: abrasive water jet Page: << < 1 2 3 4 5 > >> 1 Australasian Fluid Mechanics Conference...

  16. Searches in photon and jet states

    SciTech Connect (OSTI)

    Soha, A.; /UC, Davis

    2007-06-01T23:59:59.000Z

    The authors present recent results from the Collider Detector at Fermilab (CDF) and D0 experiments using data from proton-antiproton collisions with {radical}s = 1.96 TeV at Run II of the Fermilab Tevatron. New physics may appear in events with high transverse momentum objects, including photons and quark or gluon jets. The results described here are of signature-based searches and model-based searches probing supersymmetry, leptoquarks, 4th generation quarks, and large extra dimensions.

  17. Radiant Energy Power Source for Jet Aircraft

    SciTech Connect (OSTI)

    Doellner, O.L.

    1992-02-01T23:59:59.000Z

    This report beings with a historical overview on the origin and early beginnings of Radiant Energy Power Source for Jet Aircraft. The report reviews the work done in Phase I (Grant DE-FG01-82CE-15144) and then gives a discussion of Phase II (Grant DE-FG01-86CE-15301). Included is a reasonably detailed discussion of photovoltaic cells and the research and development needed in this area. The report closes with a historical perspective and summary related to situations historically encountered on projects of this nature. 15 refs.

  18. Do high redshift quasars have powerful jets?

    E-Print Network [OSTI]

    Fabian, A. C.; Walker, S. A.; Celotti, A.; Ghisellini, G.; Mocz, P.; Blundell, K. M.; McMahon, R. G.

    2014-06-04T23:59:59.000Z

    for the injection spectrum and surrounding gas profile (set [A] in Mocz et al (2011): the in- jection spectrum is given by a power-law index 2.14 and Lorentz factors ranging between 1 to 106; the surrounding density profile has a powerlaw index of 1.5). We assume... the galaxy hosts of quasars at z > 3 are com- pact (Szomoru et al 2013), and their group and cluster gas have more energy than is explainable by gravitational infall alone (Wu et al 2000; McCarthy et al 2012). Powerful jets are a considerable source of energy...

  19. BioJet Corporation | 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 Center Home5b9fcbce19 NoPublic Utilities Address: 160Benin: Energy ResourcesJersey:form View source History View NewLtdBioFuelsBioJet

  20. Plasma Jet Driven Magneto-Inertial Fusion (PJMIF)

    E-Print Network [OSTI]

    National Security, LLC for NNSA LA-UR-11-07030 #12;Plasma jet experiments can provide cm National Security, LLC for NNSA Imploding plasma liner formed by 30 merging plasma jets with 1.5 MJ, LLC for NNSA MIF ICF Basko et al., Nucl. Fusion, 2000 Magnetic field reduces thermal transport

  1. Energy Conservation Constraints on Multiplicity Correlations in QCD Jets

    E-Print Network [OSTI]

    J. -L. Meunier; R. Peschanski

    1996-03-13T23:59:59.000Z

    We compute analytically the effects of energy conservation on the self-similar structure of parton correlations in QCD jets. The calculations are performed both in the constant and running coupling cases. It is shown that the corrections are phenomenologically sizeable. On a theoretical ground, energy conservation constraints preserve the scaling properties of correlations in QCD jets beyond the leading log approximation.

  2. Atmospheric Pressure Plasma Jet Treatment of Polyethylene Surfaces for

    E-Print Network [OSTI]

    Greifswald, Ernst-Moritz-Arndt-Universität

    Atmospheric Pressure Plasma Jet Treatment of Polyethylene Surfaces for Adhesion Improvement Uwe studied the activation mechanism of polyethylene (PE) for a pretreatment with a commercial APPJ system jet system from Plasmatreat GmbH (Steinhagen, Germany) was used for the Full Paper Polyethylene (PE

  3. INTERNAL GRAVITY WAVES FROM ATMOSPHERIC JETS AND FRONTS

    E-Print Network [OSTI]

    Plougonven, Riwal

    INTERNAL GRAVITY WAVES FROM ATMOSPHERIC JETS AND FRONTS Riwal Plougonven1 and Fuqing Zhang2 consistently highlighted jet exit regions as a favored locus for intense gravity waves, the mechanisms need for improving parameterizations of nonorographic gravity waves in climate models that include

  4. Acid Placement in Acid Jetting Treatments in Long Horizontal Wells

    E-Print Network [OSTI]

    Sasongko, Hari

    2012-07-16T23:59:59.000Z

    In the Middle East, extended reach horizontal wells (on the order of 25,000 feet of horizontal displacement) are commonly acid stimulated by jetting acid out of drill pipe. The acid is jetted onto the face of the openhole wellbore as the drill pipe...

  5. Acid placement and coverage in the acid jetting process

    E-Print Network [OSTI]

    Mikhailov, Miroslav I.

    2009-05-15T23:59:59.000Z

    Many open-hole acid treatments are being conducted by pumping acid through jetting ports placed at the end of coiled tubing or drill pipe. The filter-cake on the bore-hole is broken by the jet; the acid-soluble material is dissolved, creating...

  6. Behavior of shale oil jet fuels at variable severities

    SciTech Connect (OSTI)

    Mukherjee, N.L.

    1988-01-01T23:59:59.000Z

    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.

  7. Modeling of NOx formation in circular laminar jet flames

    E-Print Network [OSTI]

    Siwatch, Vivek

    2007-04-25T23:59:59.000Z

    -premixed isolated circular laminar jet flame. The jet consists of the fuel rich inner region and the O2 rich outer region. The model estimates both thermal NOx and prompt NOx assuming single step kinetics for NOx formation and a thin flame model. Further the amount...

  8. Measurements of Vector Bosons Produced in Association with Jets

    E-Print Network [OSTI]

    Cooper, Ben

    2008-01-01T23:59:59.000Z

    The latest D0 and CDF measurements of the important $W+{\\rm jets}$ and $Z/\\gamma^{*}+{\\rm jets}$ processes are described, along with a discussion of the comparisons that have been made to LO and NLO perturbative QCD predictions.

  9. Characterization of turbulent jet mixing in cylindrical tanks

    E-Print Network [OSTI]

    Schulte, Casey M

    1998-01-01T23:59:59.000Z

    , for the most part, confirms many of the findings of previous studies of jet mixing. First, mixing time in jet-mixed systems depends primarily upon the mass of the fluid in a tank and the amount of addition, to maximize the efficient transfer of momentum...

  10. Modified Black Hole with Polar Jet and Vortex

    E-Print Network [OSTI]

    T. Tmmalm

    2001-12-06T23:59:59.000Z

    There are many models relating an accretion disk of Black Hole to jet outflow. The herein heuristic model describes the continuation of an external accretion disk to an internal accretion disk for less than Black Hole horizon, and subsequent polar jet outflow along polar axis out of polar vortex wherein the event horizon is no longer descriptive.

  11. Search for New Physics in the Jets + Missing ET topology

    SciTech Connect (OSTI)

    Makovec, Nikola Michel; /Orsay

    2006-05-01T23:59:59.000Z

    Although the standard model of particle physics agrees perfectly with experimental data, it is unlikely the final theory describing particles and their interactions. New phenomena has been searched in the jets and missing transverse energy topology. Such phenomena may be due to the pair production of leptoquarks decaying into a quark and a neutrino or the pair production of stops decaying into a charm and a neutralino which is assumed to be the lightest supersymmetric particle. These searches have been performed with the D0 detector at hadronic collider TeVatron with a center of mass energy of 1.96 TeV. This kind of search needs a good understanding of the jet energy calibration. The determination of the relative jet energy scale has allowed them to reduce the systematic uncertainties on the jet energy measurement when comparing the data and the simulation. Moreover a new method has been developed in order to correct simulated jets for the differences observed in the jet energy scale, the jet energy resolution and the jet reconstruction efficiency between the data and the simulation. The data analysis, performed with an integrated luminosity of 310 pb{sup -1}, has not observed any excess. This result is interpreted in terms of limit on the mass of the particles: leptoquarks with a mass smaller than 136 GeV and stops with a mass smaller than 131 GeV, for a neutralino mass equal to 46 GeV, are excluded with 95% confidence level.

  12. Ag/AgBr/g-C{sub 3}N{sub 4}: A highly efficient and stable composite photocatalyst for degradation of organic contaminants under visible light

    SciTech Connect (OSTI)

    Cao, Jing, E-mail: caojing@mail.ipc.ac.cn [College of Chemistry and Materials Science, Huaibei Normal University, Huaibei 235000, Anhui (China); State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Zhao, Yijie; Lin, Haili; Xu, Benyan [College of Chemistry and Materials Science, Huaibei Normal University, Huaibei 235000, Anhui (China); Chen, Shifu, E-mail: chshifu@chnu.edu.cn [College of Chemistry and Materials Science, Huaibei Normal University, Huaibei 235000, Anhui (China)

    2013-10-15T23:59:59.000Z

    Graphical abstract: Ag/AgBr/g-C{sub 3}N{sub 4} composite photocatalysts displayed excellent photocatalytic activities on the degradation of methyl orange (MO) under visible light. The improved photocatalytic performance and stability of Ag/AgBr/g-C{sub 3}N{sub 4} originated from the synergetic effects of AgBr/g-C{sub 3}N{sub 4} interface and metallic Ag nanoparticles. ·O{sub 2}?, one of the reactive species, was responsible for the photodegradation of MO compared to H+ and ·OH. - Highlights: • Novel Ag/AgBr/g-C{sub 3}N{sub 4} composite photocatalyst was reported. • Ag/AgBr/g-C{sub 3}N{sub 4} had novel energy band combination between AgBr and g-C{sub 3}N{sub 4}. • Synergetic effects of AgBr/g-C{sub 3}N{sub 4} interface and metallic Ag nanoparticles. • Electron trapping role of metallic Ag dominated the stability of Ag/AgBr/g-C{sub 3}N{sub 4}. - Abstract: Novel Ag/AgBr/g-C{sub 3}N{sub 4} composite photocatalysts were constructed via deposition–precipitation method and extensively characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and UV–vis diffuse reflectance spectroscopy (DRS). Under visible light (? > 420 nm), Ag/AgBr/g-C{sub 3}N{sub 4} composite photocatalysts displayed much higher photocatalytic activities than those of Ag/AgBr and g-C{sub 3}N{sub 4} for degradation of methyl orange (MO). 50% Ag/AgBr/g-C{sub 3}N{sub 4} presented the best photocatalytic performance, which was mainly attributed to the synergistic effects of AgBr/g-C{sub 3}N{sub 4} interface and the in situ metallic Ag nanoparticles for efficiently separating electron–hole pairs. Furthermore, Ag/AgBr/g-C{sub 3}N{sub 4} remained good photocatalytic activity through 5 times of cycle experiments. Additionally, the radical scavengers experiment indicated that ·O{sub 2}{sup ?} was the main reactive species for the MO degradation under visible light.

  13. Di-jet asymmetric momentum transported by QGP fluid

    E-Print Network [OSTI]

    Yasuki Tachibana; Tetsufumi Hirano

    2014-10-15T23:59:59.000Z

    We study the collective flow of the {QGP}-fluid which transports the energy and momentum deposited from jets. Simulations of the propagation of jets together with expansion of the {QGP}-fluid are performed by solving relativistic hydrodynamic equations numerically in the fully (3+1)-dimensional space. Mach cones are induced by the energy-momentum deposition from jets and extended by the expansion of the {QGP}. As a result, a large fraction of the transverse momentum deposited from jets is compensated by low-$p_{T}$ particles at large angles from the jet axis. This result is consistent with the data from the {CMS} Collaboration and gives a novel interpretation of them.

  14. Spin analyzing power for polarized top decays with jets

    E-Print Network [OSTI]

    Yoshio Kitadono; Hsiang-nan Li

    2014-04-10T23:59:59.000Z

    We perform perturbative QCD factorization of infrared radiations associated with an energetic $b$ quark from a polarized top quark decay, taking the semi-leptonic channel as an example. The resultant formula is expressed as a convolution of an infrared-finite heavy-quark kernel with a $b$-quark jet function. Evaluating the heavy-quark kernel up to leading order in the coupling constant and adopting the jet function from QCD resummation, we predict the dependence of the spin analyzing power for a polarized top quark on the invariant mass of the $b$-quark jet. It is observed that the spin analyzing power could be enhanced by a factor 2 compared to the inclusive case with the jet mass being integrated over. It is worthwhile to test experimentally the enhancement of the spin analyzing power due to the inclusion of jet dynamics.

  15. Phase Space and Jet Definitions in SCET

    E-Print Network [OSTI]

    William Man-Yin Cheung; Michael Luke; Saba Zuberi

    2009-10-13T23:59:59.000Z

    We discuss consistent power counting for integrating soft and collinear degrees of freedom over arbitrary regions of phase space in the soft-collinear effective theory (SCET), and illustrate our results at one loop with several jet algorithms: JADE, Sterman-Weinberg and k_T. Consistently applying SCET power-counting in phase space, along with non-trivial zero-bin subtractions, prevents double-counting of final states. The resulting phase-space integrals over soft and collinear regions are individually ultraviolet divergent, but the phase-space ultraviolet divergences cancel in the sum. Whether the soft and collinear contributions are individually infrared safe depends on the jet definition. We show that while this is true at one loop for JADE and Sterman-Weinberg, the k_T algorithm does not factorize into individually infrared safe soft and collinear pieces in dimensional regularization. We point out that this statement depends on the ultraviolet regulator, and that in a cutoff scheme the soft functions are infrared safe.

  16. Large area atmospheric-pressure plasma jet

    DOE Patents [OSTI]

    Selwyn, Gary S. (Los Alamos, NM); Henins, Ivars (Los Alamos, NM); Babayan, Steve E. (Huntington Beach, CA); Hicks, Robert F. (Los Angeles, CA)

    2001-01-01T23:59:59.000Z

    Large area atmospheric-pressure plasma jet. A 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 planar, parallel electrodes are employed to generate a plasma in the volume 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 spacing the rf-powered electrode. Because of the atmospheric pressure operation, there is a negligible density of ions surviving for a sufficiently long distance beyond the active plasma discharge to bombard a workpiece, unlike the situation for low-pressure plasma sources and conventional plasma processing methods.

  17. First Dark Matter Search Results from a 4-kg CF$_3$I Bubble Chamber Operated in a Deep Underground Site

    SciTech Connect (OSTI)

    Behnke, E.; /Indiana U., South Bend; Behnke, J.; /Indiana U., South Bend; Brice, S.J.; /Fermilab; Broemmelsiek, D.; /Fermilab; Collar, J.I.; /Chicago U., EFI; Conner, A.; /Indiana U., South Bend; Cooper, P.S.; /Fermilab; Crisler, M.; /Fermilab; Dahl, C.E.; /Chicago U., EFI; Fustin, D.; /Chicago U., EFI; Grace, E.; /Indiana U., South Bend /Fermilab

    2012-04-01T23:59:59.000Z

    New data are reported from the operation of a 4.0 kg CF{sub 3}I bubble chamber in the 6800 foot deep SNOLAB underground laboratory. The effectiveness of ultrasound analysis in discriminating alpha decay background events from single nuclear recoils has been confirmed, with a lower bound of >99.3% rejection of alpha decay events. Twenty single nuclear recoil event candidates and three multiple bubble events were observed during a total exposure of 553 kg-days distributed over three different bubble nucleation thresholds. The effective exposure for single bubble recoil-like events was 437.4 kg-days. A neutron background internal to the apparatus, of known origin, is estimated to account for five single nuclear recoil events and is consistent with the observed rate of multiple bubble events. This observation provides world best direct detection constraints on WIMP-proton spin-dependent scattering for WIMP masses >20 GeV/c{sup 2} and demonstrates significant sensitivity for spin-independent interactions.

  18. Retention of Hydrogen in FCC Metals Irradiated at Temperatures Leading to High Densities of Bubbles or Voids

    SciTech Connect (OSTI)

    Garner, Francis A.; Simonen, Edward P.; Oliver, Brian M.; Greenwood, Lawrence R.; Grossbeck, M L.; Wolfer, W. G.; Scott, P M.

    2006-09-15T23:59:59.000Z

    Large amounts of hydrogen and helium are generated in structural metals in accelerator-driven systems. It is shown that under certain conditions, hydrogen can be stored in irradiated nickel and stainless steels at levels strongly in excess of that predicted by Sieverts Law. These conditions are first, the availability of hydrogen from various radiolytic and environmental sources and second, the formation of radiation-induced cavities to store hydrogen. These cavities can be highly pressurized bubbles or under-pressurized voids, with concurrent helium in the cavities at either low or very high levels. Transmutant sources of hydrogen are often insufficient to pressurize these cavities, and therefore environmental sources are required. The stored hydrogen appears to be stable for many years at room temperature. A conceptual model to describe such behavior requires the continuous generation of hydrogen from (n, p) reactions and possibly other radiolytic sources which can create a supersaturation of hydrogen in the metal, leading to the pressurization of voids and helium bubbles. Once captured in a bubble, the hydrogen is assumed to be in molecular form. Dissolution back into the metal requires chemisorption and dissociation on the bubble surface. Both of these processes have large activation barriers, particularly when oxygen, carbohydrates, and other impurities poison the bubble surface. However, these chemisorbed poisons may reduce but not entirely restrict the ingress or egress of atomic hydrogen.

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

    SciTech Connect (OSTI)

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

    1999-07-01T23:59:59.000Z

    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.

  20. Drying: a comparison of radial jet reattachment and standard in-line jets

    E-Print Network [OSTI]

    Habetz, Darren Keith

    2012-06-07T23:59:59.000Z

    line of the nozzle but is shown in two dimensions as seen in the flow visualization. The flow rate of water corresponds to an exit velocity in air of approximately 75 meters per second, using Reynolds number similarity. The reattachment ring.... In this research endeavor, RJR nozzles have been compared to the drying industry's common method of air impingement drying, namely, standard In-Line Jets (ILJ), for several different combinations of flow and geometrical parameters. This gives evidence...

  1. X-ray Emission Processes in Radio Jets

    E-Print Network [OSTI]

    D. E. Harris; H. Krawczynski

    2001-09-27T23:59:59.000Z

    The emission processes responsible for the observed X-rays from radio jets are commonly believed to be non-thermal, but in any particular case, it is unclear if synchrotron emission or one or more varieties of inverse Compton emission predominates. We present a formulation of inverse Compton emission from a relativistically moving jet (``IC/beaming'') which relies on radio emitting synchrotron sources for which the energy densities in particles and fields are comparable. We include the non-isotropic nature of inverse Compton scattering of the relativistic electrons on photons of the cosmic microwave background (CMB) and provide beaming parameters for a number of jets. A list of X-ray emitting jets is given and the jets are classified on the basis of their morphology and spectral energy distribution to determine their likely emission process. We conclude that these jets have significant bulk relativistic velocities on kpc scales; that higher redshift sources require less beaming because the energy density of the CMB is significantly greater than locally; and that for some nearby sources, synchrotron X-ray emission predominates because the jet makes a large angle to the line of sight.

  2. Effect of severity on catalytic hydroprocessed shale oil jet fuels

    SciTech Connect (OSTI)

    Mukherjee, N.L.

    1987-01-01T23:59:59.000Z

    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.

  3. Gamma-ray burst jets: uniform or structured?

    E-Print Network [OSTI]

    Salafia, O S; Nappo, F; Ghisellini, G; Ghirlanda, G; Salvaterra, R; Tagliaferri, G

    2015-01-01T23:59:59.000Z

    The structure of Gamma-Ray Burst (GRB) jets impacts on their prompt and afterglow emission properties. Insights into the still unknown structure of GRBs can be achieved by studying how different structures impact on the luminosity function (LF): i) we show that low ($10^{46} 10^{50}$ erg/s) luminosity GRBs can be described by a unique LF; ii) we find that a uniform jet (seen on- and off-axis) as well as a very steep structured jet (i.e. $\\epsilon(\\theta) \\propto \\theta^{-s}$ with $s > 4$) can reproduce the current LF data; iii) taking into account the emission from the whole jet (i.e. including contributions from mildly relativistic, off-axis jet elements) we find that $E_{\\rm iso}(\\theta_{\\rm v})$ (we dub this quantity "apparent structure") can be very different from the intrinsic structure $\\epsilon(\\theta)$: in particular, a jet with a Gaussian intrinsic structure has an apparent structure which is more similar to a power law. This opens a new viewpoint on the quasi-universal structured jet hypothesis.

  4. The JET Hydrogen-Oxygen Recombination Sensor – A Safety Device for Hydrogen Isotope Processing Systems

    E-Print Network [OSTI]

    The JET Hydrogen-Oxygen Recombination Sensor – A Safety Device for Hydrogen Isotope Processing Systems

  5. Tungsten Transport in JET H-mode Plasmas in Hybrid Scenario, Experimental Observations and Modelling

    E-Print Network [OSTI]

    Tungsten Transport in JET H-mode Plasmas in Hybrid Scenario, Experimental Observations and Modelling

  6. Bouncing jet: A Newtonian liquid rebounding off a free surface Matthew Thrasher,* Sunghwan Jung,

    E-Print Network [OSTI]

    Weeks, Eric R.

    horizontally with respect to the jet. Previous observations of jets rebounding off a bath e.g., the Kaye effect of Newtonian fluids, including mineral oil poured by hand. A thin layer of air separates the bouncing jet from in studying the bouncing jet e.g., noncoalescence, lubrication, and entrainment are ubiq- uitous in fluid

  7. Overview of Transport, Fast Particle and Heating and Current Drive Physics using Tritium in JET plasmas

    E-Print Network [OSTI]

    Overview of Transport, Fast Particle and Heating and Current Drive Physics using Tritium in JET plasmas

  8. Effect of Sawtooth Activity on Tritium and Beam Deuterium Evolution in Trace Tritium Experiments on JET

    E-Print Network [OSTI]

    Effect of Sawtooth Activity on Tritium and Beam Deuterium Evolution in Trace Tritium Experiments on JET

  9. New Safety and Technical Challenges and Operational Experience on the JET First Trace Tritium Experiment

    E-Print Network [OSTI]

    New Safety and Technical Challenges and Operational Experience on the JET First Trace Tritium Experiment

  10. Overview of Transport, Fast Particle and Heating and Current Drive Physics using Tritium in JET Plasmas

    E-Print Network [OSTI]

    Overview of Transport, Fast Particle and Heating and Current Drive Physics using Tritium in JET Plasmas

  11. 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

  12. Algorithms for the Automatic Identification of MARFEs and UFOs in JET Database of Visible Camera Videos

    E-Print Network [OSTI]

    Algorithms for the Automatic Identification of MARFEs and UFOs in JET Database of Visible Camera Videos

  13. Analysis and Measurement of Bubble Dynamics and Associated Flow Field in Subcooled Nucleate Boiling Flows

    SciTech Connect (OSTI)

    Barclay G. Jones

    2008-10-01T23:59:59.000Z

    In recent years, subooled nucleate boiling (SNB) has attrcted expanding research interest owing to the emergence of axial offset anomaly (AOA) or crud-induced power shigt (CIPS) in many operating US PWRs, which is an unexpected deviation in the core axial power distribution from the predicted power curves. Research indicates that the formation of the crud, which directly leads to AOA phenomena, results from the presence of the subcooled nucleate boiling, and is especially realted to bubble motion occurring in the core region.

  14. Method for gas bubble and void control and removal from metals

    DOE Patents [OSTI]

    Siclen, C.D. Van; Wright, R.N.

    1996-02-06T23:59:59.000Z

    A method is described for enhancing the diffusion of gas bubbles or voids attached to impurity precipitates, and biasing their direction of migration out of the host metal (or metal alloy) by applying a temperature gradient across the host metal (or metal alloy). In the preferred embodiment of the present invention, the impurity metal is insoluble in the host metal and has a melting point lower than the melting point of the host material. Also, preferably the impurity metal is lead or indium and the host metal is aluminum or a metal alloy. 2 figs.

  15. Bubble microstructure evolution and helium behavior in He{sup +} implanted Ni-base alloys

    SciTech Connect (OSTI)

    Kalin, B.A.; Chernov, I.I.; Kalashnikov, A.N.; Solovyev, B.G. [Moscow State Engineering Physics Inst., Moscow (Russian Federation). Dept. of Physical Problems of Materials Science

    1996-12-31T23:59:59.000Z

    Behavior of ion-implanted helium in Ni as a function of alloying element concentration (Al or Ti) and irradiation conditions (at 20 or 750 C) have been investigated by means of thermal desorption spectrometry (TDS) and transmission electron microscopy (TEM). Substitution elements in solid solution were demonstrated to have substantial influence on the evolution of implanted helium, shifting the TDS spectrum peaks to higher temperature region and increasing the quantity of helium remaining in the samples after long-time postirradiation annealing. TEM investigations showed that in the case of postirradiation annealing, helium bubbles are formed earlier in quenched alloys than in those annealed.

  16. The prevention of oil spreading on water by pneumatic bubble barrier

    E-Print Network [OSTI]

    McClenan, Cecil Michael

    1971-01-01T23:59:59.000Z

    74 1 g RIVI 2 &RUN 3 ARUN 4 ARUN 5 SG =- 0. 85 0 H = 1. 0 T =. 20 ft TEST 8 ORUN 2 '+RUN 3 QRUN 4 SG = 0. 89 0 II = 1. 0 ft T = 2 0 ft V m: r. (5) SG = 0. 85 0 II = 7. 5 T = 7. 5 ft b, ok 0 0 QQ OO 0. 5 /y 0 0. 0 0. 0 0. 5 1... May 1971 Major Subject: Civil Engineering PREVENTION OF OIL SPREADING ON WATER BY PNEUMATIC BUBBLE BARRIER A Thesis by CECIL MICHAFL MCCLENAN Approved as to style and content by: hazrman of Committee Head of Departme n i(. ~aj ~m Member...

  17. A beta-type fully implicit reservoir simulator with variable bubble point and dew point

    E-Print Network [OSTI]

    Boe, Jarle

    1980-01-01T23:59:59.000Z

    the following equation. V P 5. 617 m g 2 QT 1000 (56) And the R curve can be obtained from the same constant volume Sg depletion by summing up the GPM content of the propane through hep- tanes plus fractions. The B and the R can then be calculated 0 so...A BETA-TYPE FULLY IMPLICIT RESERVOIR SIMULATOR WITH VARIABLE BUBBLE POINT AND DEW POINT A Thesis by JARLE BOE Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER...

  18. Experimental study on bubble collapse phenomena in subcooled water with three-dimensional particle image velocimetry

    E-Print Network [OSTI]

    Yang, Yu-Hsiang

    1998-01-01T23:59:59.000Z

    pressure), rr is surface tension, and p, is the shear viscosity of the liquid. Many researchers were interested in cavitation adjacent to a ngid boundary (Naude and Ellis 1961, and Benjamm and Ellis 1966). Cavitation damage induced by flow is often most... is higher than one without a phase change. This is due to the agitation of the hquid in the boundary layer generated by the growing and collapsing bubbles. The name cavitation was given by R. E. Froude, an English naval architect, m 1895 to descnbe...

  19. Method for gas bubble and void control and removal from metals

    DOE Patents [OSTI]

    Van Siclen, Clinton D. (Idaho Falls, ID); Wright, Richard N. (Idaho Falls, ID)

    1996-01-01T23:59:59.000Z

    A method for enhancing the diffusion of gas bubbles or voids attached to impurity precipitates, and biasing their direction of migration out of the host metal (or metal alloy) by applying a temperature gradient across the host metal (or metal alloy). In the preferred embodiment of the present invention, the impurity metal is insoluble in the host metal and has a melting point lower than the melting point of the host material. Also, preferably the impurity metal is lead or indium and the host metal is aluminum or a metal alloy.

  20. Bubbles Help Break Energy Storage Record for Lithium Air-Batteries

    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 May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone6Energy, science, and technology for theBubbles Help Break

  1. Turbulent round jet under gravity waves

    E-Print Network [OSTI]

    Ryu, Yong Uk

    2002-01-01T23:59:59.000Z

    ) Turbulent shear stress &u'w'&/&u, & versus z/x. . . 26 3-5 Overlapped mean axial velocity &u&/&u, & versus zJx of the case of A = 0. 5 cm at six locations corresponding to figure 3-4(a) . . 28 3-6 Horizontal turbulent velocity &u' &' /&u, & versus zJx... of the case of A = 0. 5 cm with z, = 0 at. the moving jet centerline in the range of (a) x/D = 40 - 95, (b) x/D = 40 ? 57, and (c) x/D = 64 - 95 . . 30 3-7 Vertical turbulent velocity &w' & /&u, & versus z Jx of the case of A = 0. 5 cm FIGURE Page with z...

  2. Higher-Order Corrections to Timelike Jets

    SciTech Connect (OSTI)

    Giele, W.T.; /Fermilab; Kosower, D.A.; /Saclay, SPhT; Skands, P.Z.; /CERN

    2011-02-01T23:59:59.000Z

    We present a simple formalism for the evolution of timelike jets in which tree-level matrix element corrections can be systematically incorporated, up to arbitrary parton multiplicities and over all of phase space, in a way that exponentiates the matching corrections. The scheme is cast as a shower Markov chain which generates one single unweighted event sample, that can be passed to standard hadronization models. Remaining perturbative uncertainties are estimated by providing several alternative weight sets for the same events, at a relatively modest additional overhead. As an explicit example, we consider Z {yields} q{bar q} evolution with unpolarized, massless quarks and include several formally subleading improvements as well as matching to tree-level matrix elements through {alpha}{sub s}{sup 4}. The resulting algorithm is implemented in the publicly available VINCIA plugin to the PYTHIA8 event generator.

  3. A FLUX ROPE ERUPTION TRIGGERED BY JETS

    SciTech Connect (OSTI)

    Guo Juan; Zhang Hongqi; Deng Yuanyong; Lin Jiaben; Su Jiangtao [Key Laboratory of Solar Activity, National Astronomical Observatories, Beijing 100012 (China); Liu Yu, E-mail: guojuan@bao.ac.c [Yunnan Astronomical Observatory, National Astronomical Observatories, Kunming 650011 (China)

    2010-03-10T23:59:59.000Z

    We present an observation of a filament eruption caused by recurrent chromospheric plasma injections (surges/jets) on 2006 July 6. The filament eruption was associated with an M2.5 two-ribbon flare and a coronal mass ejection (CME). There was a light bridge in the umbra of the main sunspot of NOAA 10898; one end of the filament was terminated at the region close to the light bridge, and recurrent surges were observed to be ejected from the light bridge. The surges occurred intermittently for about 8 hr before the filament eruption, and finally a clear jet was found at the light bridge to trigger the filament eruption. We analyzed the evolutions of the relative darkness of the filament and the loaded mass by the continuous surges quantitatively. It was found that as the occurrence of the surges, the relative darkness of the filament body continued growing for about 3-4 hr, reached its maximum, and kept stable for more than 2 hr until it erupted. If suppose 50% of the ejected mass by the surges could be trapped by the filament channel, then the total loaded mass into the filament channelwill be about 0.57x10{sup 16} g with a momentum of 0.57x10{sup 22} g cm s{sup -1} by 08:08 UT, which is a non-negligible effect on the stability of the filament. Based on the observations, we present a model showing the important role that recurrent chromospheric mass injection play in the evolution and eruption of a flux rope. Our study confirms that the surge activities can efficiently supply the necessary material for some filament formation. Furthermore, our study indicates that the continuous mass with momentum loaded by the surge activities to the filament channel could make the filament unstable and cause it to erupt.

  4. AEA Fluidic Pulse Jet Mixer. Innovative Technology Summary Report

    SciTech Connect (OSTI)

    None

    1999-08-01T23:59:59.000Z

    AEA's Fluidic Pulse Jet Mixer was developed to mix and maintain the suspension of solids and to blend process liquids. The mixer can be used to combine a tank's available supernate with the sludge into a slurry that is suitable for pumping. The system uses jet nozzles in the tank coupled to a charge vessel. Then, a jet pump creates a partial vacuum in the charge vessel allowing it to be filled with waste. Next, air pressure is applied to the charge vessel, forcing sludge back into the tank and mixing it with the liquid waste. When the liquid waste contains 10% solids, a batch is pumped out of the tank.

  5. High order harmonic generation in dual gas multi-jets

    SciTech Connect (OSTI)

    Tosa, Valer, E-mail: valer.tosa@itim-cj.ro, E-mail: calin.hojbota@itim-cj.ro; Hojbota, Calin, E-mail: valer.tosa@itim-cj.ro, E-mail: calin.hojbota@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, Donath 65-103, 400293 Cluj-Napoca (Romania)] [National Institute for Research and Development of Isotopic and Molecular Technologies, Donath 65-103, 400293 Cluj-Napoca (Romania)

    2013-11-13T23:59:59.000Z

    High order harmonic generation (HHG) in gas media suffers from a low conversion efficiency that has its origins in the interaction of the atom/molecule with the laser field. Phase matching is the main way to enhance the harmonic flux and several solutions have been designed to achieve it. Here we present numerical results modeling HHG in a system of multi-jets in which two gases alternate: the first gas jet (for example Ne) generates harmonics and the second one which ionizes easier, recover the phase matching condition. We obtain configurations which are experimentally feasible with respect to pressures and dimensions of the jets.

  6. Panchromatic Views of Large-Scale Extragalactic Jets

    SciTech Connect (OSTI)

    Cheung, C.C.; /KIPAC, Menlo Park

    2007-06-01T23:59:59.000Z

    Highlights of recent observations of extended jets in AGN are presented. Specifically, we discuss new spectral constraints enabled by Spitzer, studies of the highest-redshift (z{approx}4) radio/X-ray quasar jets, and a new VLBA detection of superluminal motion in the M87 jet associated with a recent dramatic X-ray outburst. Expanding on the title, inverse Compton emission from extended radio lobes is considered and a testable prediction for the gamma-ray emission in one exemplary example is presented. Prospects for future studies with ALMA and low-frequency radio interferometers are briefly described.

  7. Measurement of electron capture and loss cross section for 41.67 MeV ??Br ions in H?

    E-Print Network [OSTI]

    Burns, James Martin

    1967-01-01T23:59:59.000Z

    . The lab frame is the rest frame of the ion. . . . . . . . . . . . . . . . . 51 Schematic diagram of the Tandem Van de Graaff Accel- erator as used to accelerate 7 Br ions. . . . . , . . . . . . . . . . 52 Schematic diagram of experimental apparatus... of this century. Initial investigations concerned the pas- sage of protons and alpha particles through matter as these were essentially the only high speed particles available at that time. Consequently, much information has been accumulated concerning...

  8. zimas para entender evoluo de leveduras -Terra Brasil 1/1...terra.com.br/.../cientistas-recriam-enzimas-para-entender-evolucao-de-leveduras,a996ed7e34c...

    E-Print Network [OSTI]

    como enzima ligada ao câncer funciona http://noticias.terra.com.br/ciencia parte do tratamento contra... http://noticias.terra.com.br/ciencia evolução de cromossomos sexuais http://noticias.terra.com.br/ciencia

  9. Heart-shaped bubbles rising in anisotropic liquids Chunfeng Zhou1, Pengtao Yue1,2, James J. Feng1,2 , Chun Liu3, Jie Shen4

    E-Print Network [OSTI]

    Shen, Jie

    Heart-shaped bubbles rising in anisotropic liquids Chunfeng Zhou1, Pengtao Yue1,2, James J. Feng1 - This Letter reports numerical simulations motivated by experimental ob- servations of an unusual inverted-heart). Such a bubble assumes a peculiar shape while in the near wake, resembling an inverted heart or a spade (a

  10. STRUCTURE OF PRESSURE PULSES IN LIQUIDS WITH GAS BUBBLES N.V. Malykh, I.A. 0G0R0DNIK0V

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    are predominant. This leads to the sound speed dispersion and determines either the short pulse structure oriSTRUCTURE OF PRESSURE PULSES IN LIQUIDS WITH GAS BUBBLES N.V. Malykh, I.A. 0G0R0DNIK0V Institute. I.-INTRODUCTION - The main specific feature of a liquide with gas bubbles is the great difference

  11. The extreme efficiency of producing bubbles via electrolysis of water has been put to use in a new design for an integrated

    E-Print Network [OSTI]

    Liepmann, Dorian

    ABSTRACT The extreme efficiency of producing bubbles via electrolysis of water has been put to use the complete system cost effective. The valves must use as little power as possible so that the entire system and hydrogen at the electrodes. Since these gas bubbles are the same temperature as their surroundings, they do

  12. Cavitation bubble dynamics in microfluidic gaps of variable height Pedro A. Quinto-Su, Kang Y. Lim, and Claus-Dieter Ohl

    E-Print Network [OSTI]

    Ohl, Claus-Dieter

    . Yet, it has been only until recently that this technique has been combined with micro- fluidic chips 5 with the bubble's acoustic emission using a hydro- phone. The bubbles are created with a tightly focused laser the back aperture of the micro- scope objective. The narrow gap is illuminated from the top through

  13. PHYSICAL STRUCTURE OF THE PLANETARY NEBULA NGC 3242 FROM THE HOT BUBBLE TO THE NEBULAR ENVELOPE

    SciTech Connect (OSTI)

    Ruiz, Nieves; Guerrero, MartIn A. [Instituto de Astrofisica de Andalucia, CSIC, Granada 18008 (Spain); Chu, You-Hua; Gruendl, Robert A., E-mail: nieves@iaa.es, E-mail: mar@iaa.es, E-mail: yhchu@astro.illinois.edu, E-mail: gruendl@astro.illinois.edu [Astronomy Department, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)

    2011-09-15T23:59:59.000Z

    One key feature of the interacting stellar winds model of the formation of planetary nebulae (PNe) is the presence of shock-heated stellar wind confined in the central cavities of PNe. This so-called hot bubble should be detectable in X-rays. Here we present XMM-Newton observations of NGC 3242, a multiple-shell PN whose shell morphology is consistent with the interacting stellar winds model. Diffuse X-ray emission is detected within its inner shell with a plasma temperature of {approx}2.35 x 10{sup 6} K and an intrinsic X-ray luminosity of {approx}2 x 10{sup 30} erg s{sup -1} at the adopted distance of 0.55 kpc. The observed X-ray temperature and luminosity are in agreement with 'ad hoc' predictions of models including heat conduction. However, the chemical abundances of the X-ray-emitting plasma seem to imply little evaporation of cold material into the hot bubble, whereas the thermal pressure of the hot gas is unlikely to drive the nebular expansion as it is lower than that of the inner shell rim. These inconsistencies are compounded by the apparent large filling factor of the hot gas within the central cavity of NGC 3242.

  14. The digital traces of bubbles: feedback cycles between socio-economic signals in the Bitcoin economy

    E-Print Network [OSTI]

    Garcia, David; Mavrodiev, Pavlin; Perony, Nicolas

    2014-01-01T23:59:59.000Z

    What is the role of social interactions in the creation of price bubbles? Answering this question requires obtaining collective behavioural traces generated by the activity of a large number of actors. Digital currencies offer a unique possibility to measure socio-economic signals from such digital traces. Here, we focus on Bitcoin, the most popular cryptocurrency. Bitcoin has experienced periods of rapid increase in exchange rates (price) followed by sharp decline; we hypothesise that these fluctuations are largely driven by the interplay between different social phenomena. We thus quantify four socio-economic signals about Bitcoin from large data sets: price on on-line exchanges, volume of word-of-mouth communication in on-line social media, volume of information search, and user base growth. By using vector autoregression, we identify two positive feedback loops that lead to price bubbles in the absence of exogenous stimuli: one driven by word of mouth, and the other by new Bitcoin adopters. We also observ...

  15. Electrically Modulated Thin Film Dynamics Controlling Bubble Manipulation in Microfluidic Confinement

    E-Print Network [OSTI]

    Debapriya Chakraborty; Suman Chakraborty

    2014-12-03T23:59:59.000Z

    Thin film dynamics and associated instability mechanisms have triggered a wide range of scientific innovations, as attributed to their abilities of creating fascinating patterns over small scales. Here, we demonstrate a new thin film instability phenomenon governed by electro-mechanics and hydrodynamics over interfacial scales in a narrow fluidic confinement. We first bring out the essential physics of this instability mechanism, in consideration with the fact that under the action of axial electrical field in a confined microfluidic environment, perturbations may be induced on the interfaces of thin corner films formed adjacent to the walls of a microchannel, leading to the inception of ordered lateral structures. A critical electric field exists beyond which these structures from the walls of the confinement intermingle to evolve into localized gas pockets in the form of bubbles. These bubbles do not remain static with further changes in electric field, but undergo a sequence of elongation-deformation-breakup episode in a dynamically evolving manner. By elucidating the complex interplay of electro-hydrodynmic forces and surface tension, we offer further insights into a new paradigm of interfacial instability mediated controlled microbubble manipulation for on-chip applications, bearing far-ranging scientific and technological consequences in executing designed fluidic operations in confined miniaturized environment.

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

    SciTech Connect (OSTI)

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

    2002-07-25T23:59:59.000Z

    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.

  17. High density cluster jet target for storage ring experiments

    E-Print Network [OSTI]

    Alexander Täschner; Esperanza Köhler; Hans-Werner Ortjohann; Alfons Khoukaz

    2011-11-02T23:59:59.000Z

    The design and performance of a newly developed cluster jet target installation for hadron physics experiments are presented which, for the first time, is able to generate a hydrogen cluster jet beam with a target thickness of above $10^{15}\\,\\mathrm{atoms/cm}^2$ at a distance of two metres behind the cluster jet nozzle. The properties of the cluster beam and of individual clusters themselves are studied at this installation. Special emphasis is placed on measurements of the target beam density as a function of the relevant parameters as well as on the cluster beam profiles. By means of a time-of-flight setup, measurements of the velocity of single clusters and velocity distributions were possible. The complete installation, which meets the requirements of future internal fixed target experiments at storage rings, and the results of the systematic studies on hydrogen cluster jets are presented and discussed.

  18. Probabilistic picture of in-medium jet evolution

    E-Print Network [OSTI]

    Yacine Mehtar-Tani

    2014-04-29T23:59:59.000Z

    We briefly discuss the recently developed probabilistic picture for in-medium jet evolution that is driven by independent multiple scatterings and branchings. These are controlled by the jet quenching parameter $\\hat q$. In this framework, large radiative corrections to $p_\\perp$-broadening of partons in the jet, enhanced by a double logarithm (DL) of the medium size $L$, are recovered. We argue that these non-local corrections are universal and can be reabsorbed in a renormalization of the jet quenching parameter without spoiling the probabilistic picture. As a consequence, we find that for large media, the mean radiative energy loss result scales as $L^{2+\\gamma}$, where the anomalous dimension $\\gamma=2\\sqrt{\\alpha_sN_c/\\pi}$.

  19. Cellular membrane collapse by atmospheric-pressure plasma jet

    SciTech Connect (OSTI)

    Kim, Kangil; Sik Yang, Sang, E-mail: jsjlee@ajou.ac.kr, E-mail: ssyang@ajou.ac.kr [Department of Electrical and Computer Engineering, Ajou University, Suwon 443-749 (Korea, Republic of); Jun Ahn, Hak; Lee, Jong-Soo, E-mail: jsjlee@ajou.ac.kr, E-mail: ssyang@ajou.ac.kr [Department of Biological Sciences, Ajou University, Suwon 443-749 (Korea, Republic of)] [Department of Biological Sciences, Ajou University, Suwon 443-749 (Korea, Republic of); Lee, Jae-Hyeok; Kim, Jae-Ho [Department of Molecular Science and Technology, Ajou University, Suwon 443-749 (Korea, Republic of)] [Department of Molecular Science and Technology, Ajou University, Suwon 443-749 (Korea, Republic of)

    2014-01-06T23:59:59.000Z

    Cellular membrane dysfunction caused by air plasma in cancer cells has been studied to exploit atmospheric-pressure plasma jets for cancer therapy. Here, we report that plasma jet treatment of cervical cancer HeLa cells increased electrical conductivity across the cellular lipid membrane and caused simultaneous lipid oxidation and cellular membrane collapse. We made this finding by employing a self-manufactured microelectrode chip. Furthermore, increased roughness of the cellular lipid membrane and sequential collapse of the membrane were observed by atomic force microscopy following plasma jet treatment. These results suggest that the cellular membrane catastrophe occurs via coincident altered electrical conductivity, lipid oxidation, and membrane roughening caused by an atmospheric-pressure plasma jet, possibly resulting in cellular vulnerability to reactive species generated from the plasma as well as cytotoxicity to cancer cells.

  20. Hydrodynamics of Hypersonic Jets: Experiments and Numerical Simulations

    E-Print Network [OSTI]

    Belan, Marco; Tordella, Daniela; Massaglia, Silvano; Ferrari, Attilio; Mignone, Andrea; Bodenschatz, Eberhard

    2011-01-01T23:59:59.000Z

    Stars form in regions of the galaxy that are denser and cooler than the mean interstellar medium. These regions are called Giant Molecular Clouds. At the beginning of their life, up to $10^5-10^6$ years, stars accrete matter from their rich surrounding environment and are origin of a peculiar phenomenon that is the jet emission. Jets from Young Stellar Objects (YSOs) are intensively studied by the astrophysical community by observations at different wavelengths, analytical and numerical modeling and laboratory experiments. Indications about the jet propagation and its resulting morphologies are here obtained by means of a combined study of hypersonic jets carried out both in the laboratory and by numerical simulations.

  1. The hydraulic bump: The surface signature of a plunging jet

    E-Print Network [OSTI]

    Labousse, M.

    When a falling jet of fluid strikes a horizontal fluid layer, a hydraulic jump arises downstream of the point of impact, provided a critical flow rate is exceeded. We here examine a phenomenon that arises below this jump ...

  2. De-commoditizing the commercial jet engine business

    E-Print Network [OSTI]

    Soucy, Arthur L

    2007-01-01T23:59:59.000Z

    This thesis project is a comprehensive application of the Delta Model at a major jet engine manufacturer. It will assess and contrast customer segmentation and customer value proposition via primary research. It will also ...

  3. Experimental High Velocity Acid Jetting in Limestone Carbonates

    E-Print Network [OSTI]

    Holland, Christopher

    2014-04-30T23:59:59.000Z

    Acid jetting is a well stimulation technique that is used in carbonate reservoirs. It typically involves injecting acid down hole at high flow rates through small orifices which cause high velocities of acid to strike the borehole wall...

  4. SS433: on the uniqueness of cool relativistic jets

    E-Print Network [OSTI]

    A. A. Panferov

    1999-05-13T23:59:59.000Z

    The relativistic jets of SS433 are outstanding for their optical thermal radiation.The radiation is produced by small clouds ($10^8$ cm) whose lifetime is about $10^3$ times larger than the gas-dynamical crushing time. We show that the clouds reside in thermal and dynamical balance as long as they collisionally interact with the wind of the supercritical accretion disk. The interaction is caused by the precessional movement of the jets and takes place only in the sweep-out zone. Beyond the sweep-out zone the interaction ceases and optical jets just terminate. The cloud magnetic field amplified in course of movement through a medium could play a role in containing a cloud. Thus, the clue to the uniqueness of the optical jets of SS433 is thought to be their precessional movement, which provides an opportunity for collisional interaction of the clouds with the wind.

  5. Microjet based noise control of supersonic jets on carrier decks

    E-Print Network [OSTI]

    Ragaller, Paul Aaron

    2014-01-01T23:59:59.000Z

    The effectiveness of ground plane water microjet control on the noise generated by a supersonic, ideally expanded, Mach 1.5, impinging jet was determined. Using a converging-diverging nozzle with a design Mach number of ...

  6. The reduction of supersonic jet noise using pulsed microjet injection

    E-Print Network [OSTI]

    Ragaller, Paul Aaron

    2007-01-01T23:59:59.000Z

    This thesis is concerned with the active control of supersonic jet noise using pulsed microjet injection at the nozzle exit. Experimental investigations were carried out using this control method on an ideally expanded ...

  7. Eddy-mean flow interactions in western boundary current jets

    E-Print Network [OSTI]

    Waterman, Stephanie N

    2009-01-01T23:59:59.000Z

    This thesis examines the nature of eddy-mean flow interactions in western boundary current jets and recirculation gyre dynamics from both theoretical and observational perspectives. It includes theoretical studies of ...

  8. A critical review of world jet transport safety

    E-Print Network [OSTI]

    Achtmann, Eric D.

    1995-01-01T23:59:59.000Z

    This thesis is intended to serve as a comprehensive introduction to world jet transport safety and aviation fire safety. Divided into six sections, this thesis contains: 1) a statistical review of overall levels of safety ...

  9. Exploration of Plasma Jets Approach to High Energy Density Physics

    SciTech Connect (OSTI)

    Chen, Chiping [Massachusetts Institute of Technology

    2013-08-26T23:59:59.000Z

    High-energy-density laboratory plasma (HEDLP) physics is an emerging, important area of research in plasma physics, nuclear physics, astrophysics, and particle acceleration. While the HEDLP regime occurs at extreme conditions which are often found naturally in space but not on the earth, it may be accessible by colliding high intensity plasmas such as high-energy-density plasma jets, plasmoids or compact toroids from plasma guns. The physics of plasma jets is investigated in the context of high energy density laboratory plasma research. This report summarizes results of theoretical and computational investigation of a plasma jet undergoing adiabatic compression and adiabatic expansion. A root-mean-squared (rms) envelope theory of plasma jets is developed. Comparison between theory and experiment is made. Good agreement between theory and experiment is found.

  10. GRAVITATIONAL WAVES OF JET PRECESSION IN GAMMA-RAY BURSTS

    SciTech Connect (OSTI)

    Sun Mouyuan; Liu Tong; Gu Weimin; Lu Jufu, E-mail: tongliu@xmu.edu.cn [Department of Physics and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen, Fujian 361005 (China)

    2012-06-10T23:59:59.000Z

    The physical nature of gamma-ray bursts (GRBs) is believed to involve an ultra-relativistic jet. The observed complex structure of light curves motivates the idea of jet precession. In this work, we study the gravitational waves of jet precession based on neutrino-dominated accretion disks around black holes, which may account for the central engine of GRBs. In our model, the jet and the inner part of the disk may precess along with the black hole, which is driven by the outer part of the disk. Gravitational waves are therefore expected to be significant from this black-hole-inner-disk precession system. By comparing our numerical results with the sensitivity of some detectors, we find that it is possible for DECIGO and BBO to detect such gravitational waves, particularly for GRBs in the Local Group.

  11. Systematic Studies of Jet Quenching in Hot Nuclear Matter

    E-Print Network [OSTI]

    Delgado, Andrea

    2011-05-04T23:59:59.000Z

    ??????????????????????????????..x CHAPTER I INTRODUCTION????????????????????????...1 Nuclear matter???????????????????????.1 The standard model of elementary particles??..?????????..1 Quark gluon plasma????????????.?????????3 Jet quenching... OF FIGURES FIGURE Page 1.1. Nuclear Matter Phase Transition Diagram????????????....................2 1.2. Colliding Particles Diagram...

  12. Jet Fragmentation in Medium and Vacuum with the PHENIX Detector

    E-Print Network [OSTI]

    Matthew Nguyen for the PHENIX Collaboration

    2010-08-08T23:59:59.000Z

    One of the most active areas of investigation in relativistic heavy-ion collisions is the study of the jet quenching phenomenon whereby hard partons lose their energy as they traverse the hot, dense matter created in such collisions. Strong parton energy loss has been observed in central nucleus-nucleus collisions as evidenced by the a large suppression of the yield of high pT hadrons as compared to the expected yield based on measurements in p+p collisions. Moreover, measurements of back-to-back correlations of charged hadrons suggest that jet shapes are strongly modified modified by the medium. The quantitative interpretation of single and di-hadron measurements is, however, complicated by the fact that the initial parton energy is unknown. A more informative measurement would be one in which the initial parton energy is known, allowing the determination of the fragmentation function, which may be effectively modified from its vacuum form by the presence of the medium. Two measurements in which the initial parton energy may be estimated are discussed in these proceedings: jet reconstruction and two- particle correlations using direct photons. Jet reconstruction in nuclear collisions is challenging due to the large background of soft particles, fluctuations of which give rise to fake jets. Direct photons can be used to estimate the initial parton energy of the recoil jet without recourse to jet reconstruction algorithms. However, such studies suffer from a smaller rate and the direct photon signal must be disentangled from a large background of decay photons. We present jet reconstruction results which use an algorithm suitable for a high multiplicity environment. We also present results of two-particle correlations using direct photons. These results are discussed in the context of medium modification to the fragmentation function.

  13. Pneumatic cleaning of sugarcane utilizing a high velocity air jet

    E-Print Network [OSTI]

    Fisher, John Ray

    2012-06-07T23:59:59.000Z

    - oped to cope with the increased amount of trash present in unburned sugarcane. This research involved the testing and computer simulation of a chopper air jet nozzle assembly. The experimental test setup included a two-stage conveyor. This conveyor... of the system was evaluated. The results of the chopper air jet nozzle assembly tests verified that the air velocity, nozzle size, chopper blade configuration and feed-in rate contributed signifi- cantly to the cleanliness of the billets. The air velo- city...

  14. Interaction of a Liquid Gallium Jet with ISTTOK Edge Plasmas

    SciTech Connect (OSTI)

    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

    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.

  15. Drum drying of black liquor using superheated steam impinging jets

    SciTech Connect (OSTI)

    Shiravi, A.H.; Mujumdar, A.S.; Kubes, G.J. [McGill Univ., Montreal, Quebec (Canada)

    1997-05-01T23:59:59.000Z

    A novel drum dryer for black liquor utilizing multiple impinging jets of superheated steam was designed and built to evaluate the performance characteristics and effects of various operating parameters thereon. Appropriate ranges of parameters such as steam jet temperature and velocity were examined experimentally to quantify the optimal operating conditions for the formation of black liquor film on the drum surface as well as the drying kinetics.

  16. Jet plume injection and combustion system for internal combustion engines

    DOE Patents [OSTI]

    Oppenheim, Antoni K. (Kensington, CA); Maxson, James A. (Berkeley, CA); Hensinger, David M. (Albany, CA)

    1993-01-01T23:59:59.000Z

    An improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as shortening the time period to attain such a maximum pressure.

  17. Transverse liquid fuel jet breakup, burning, and ignition

    SciTech Connect (OSTI)

    Li, H.

    1990-01-01T23:59:59.000Z

    An analytical/numerical study of the breakup, burning, and ignition of liquid fuels injected transversely into a hot air stream is conducted. The non-reacting liquid jet breakup location is determined by the local sonic point criterion first proposed by Schetz, et al. (1980). Two models, one employing analysis of an elliptical jet cross-section and the other employing a two-dimensional blunt body to represent the transverse jet, have been used for sonic point calculations. An auxiliary criterion based on surface tension stability is used as a separate means of determining the breakup location. For the reacting liquid jet problem, a diffusion flame supported by a one-step chemical reaction within the gaseous boundary layer is solved along the ellipse surface in subsonic crossflow. Typical flame structures and concentration profiles have been calculated for various locations along the jet cross-section as a function of upstream Mach numbers. The integrated reaction rate along the jet cross-section is used to predict ignition position, which is found to be situated near the stagnation point. While a multi-step reaction is needed to represent the ignition process more accurately, the present calculation does yield reasonable predictions concerning ignition along a curved surface.

  18. Transverse liquid fuel jet breakup, burning, and ignition

    SciTech Connect (OSTI)

    Li, H.

    1990-12-31T23:59:59.000Z

    An analytical/numerical study of the breakup, burning, and ignition of liquid fuels injected transversely into a hot air stream is conducted. The non-reacting liquid jet breakup location is determined by the local sonic point criterion first proposed by Schetz, et al. (1980). Two models, one employing analysis of an elliptical jet cross-section and the other employing a two-dimensional blunt body to represent the transverse jet, have been used for sonic point calculations. An auxiliary criterion based on surface tension stability is used as a separate means of determining the breakup location. For the reacting liquid jet problem, a diffusion flame supported by a one-step chemical reaction within the gaseous boundary layer is solved along the ellipse surface in subsonic crossflow. Typical flame structures and concentration profiles have been calculated for various locations along the jet cross-section as a function of upstream Mach numbers. The integrated reaction rate along the jet cross-section is used to predict ignition position, which is found to be situated near the stagnation point. While a multi-step reaction is needed to represent the ignition process more accurately, the present calculation does yield reasonable predictions concerning ignition along a curved surface.

  19. Measurements of Vector Bosons Produced in Association with Jets

    SciTech Connect (OSTI)

    Cooper, Ben; /University Coll. London

    2008-07-01T23:59:59.000Z

    The latest D0 and CDF measurements of the W + jets and Z/{gamma}* + jets processes are described, along with a discussion of the comparisons that have been made to LO and NLO perturbative QCD predictions. The direct production of W{sup {+-}}/Z bosons in association with jets is a process of crucial importance at hadron collider experiments. The presence of a vector boson in the hard scatter means that these interactions occur at a scale that should make perturbative QCD applicable, and thus it is an excellent channel to test such predictions. Furthermore, many of the potential discovery channels for the Higgs boson and beyond standard model processes share a final state signature with the W{sup {+-}}/Z + jets process. It is thus vital for the success of existing and future hadron collider experiments that this process is understood, and recently there has been a huge amount of work put into the modeling of this process, with the appearance of many new Monte Carlo generators that are already widely used at both the Tevatron and LHC. In Sections 2 and 3 the latest W + jets and Z/{gamma}* + jets measurements from the Tevatron are presented, and in Section 4 we discuss the results and implications of some of the theory comparisons that have thus far been made.

  20. Jet plume injection and combustion system for internal combustion engines

    DOE Patents [OSTI]

    Oppenheim, A.K.; Maxson, J.A.; Hensinger, D.M.

    1993-12-21T23:59:59.000Z

    An improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as shortening the time period to attain such a maximum pressure. 24 figures.