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Note: This page contains sample records for the topic "br jet bubbling" from the National Library of EnergyBeta (NLEBeta).
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1

Jet Drops Produced by Bubbles Bursting at the Surface of Seawater  

Science Conference Proceedings (OSTI)

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

Jin Wu

2002-11-01T23:59:59.000Z

2

Jet Jet Jet Jet  

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

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

3

Enhanced boiling heat transfer by submerged, vibration induced jets .  

E-Print Network (OSTI)

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

Tillery, Steven W.

2005-01-01T23:59:59.000Z

4

Bubble diagnostics  

DOE Patents (OSTI)

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

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

2003-01-01T23:59:59.000Z

5

Geothermal br Resource br Area Geothermal br Resource br Area Geothermal  

Open Energy Info (EERE)

Tectonic br Setting Host br Rock br Age Host br Rock br Lithology Tectonic br Setting Host br Rock br Age Host br Rock br Lithology Mean br Capacity Mean br Reservoir br Temp Amedee Geothermal Area Amedee Geothermal Area Walker Lane Transition Zone Geothermal Region Extensional Tectonics Mesozoic granite granodiorite MW K Beowawe Hot Springs Geothermal Area Beowawe Hot Springs Geothermal Area Central Nevada Seismic Zone Geothermal Region Extensional Tectonics MW K Blue Mountain Geothermal Area Blue Mountain Geothermal Area Northwest Basin and Range Geothermal Region Extensional Tectonics triassic metasedimentary MW K Brady Hot Springs Geothermal Area Brady Hot Springs Geothermal Area Northwest Basin and Range Geothermal Region Extensional Tectonics MW Coso Geothermal Area Coso Geothermal Area Walker Lane Transition Zone

6

Bubble oscillations and motion under vibration  

E-Print Network (OSTI)

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

O'Hern, Tim; Torczynski, John

2011-01-01T23:59:59.000Z

7

Jet Observables Without Jet Algorithms  

E-Print Network (OSTI)

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

Daniele Bertolini; Tucker Chan; Jesse Thaler

2013-10-28T23:59:59.000Z

8

A Gold Bubble?  

E-Print Network (OSTI)

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

Robert A. Jarrow; Younes Kchia; Philip Protter

2011-01-01T23:59:59.000Z

9

Shaping Planetary Nebulae by Jets  

E-Print Network (OSTI)

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

Muhammad Akashi

2007-09-06T23:59:59.000Z

10

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

Science Conference Proceedings (OSTI)

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

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

2010-11-01T23:59:59.000Z

11

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

Science Conference Proceedings (OSTI)

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

Jin Wu

2000-01-01T23:59:59.000Z

12

Charged Vacuum Bubble Stability  

E-Print Network (OSTI)

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

J. R. Morris

1998-10-20T23:59:59.000Z

13

The thermodynamics of bubbles  

E-Print Network (OSTI)

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

Clark, John A.

1956-01-01T23:59:59.000Z

14

CONTINUOUSLY SENSITIVE BUBBLE CHAMBER  

DOE Patents (OSTI)

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

Good, R.H.

1959-08-18T23:59:59.000Z

15

Mechanisms of gas bubble retention  

Science Conference Proceedings (OSTI)

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

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

1994-09-01T23:59:59.000Z

16

Microsoft Word - HgAcBr  

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

(AC-Br) (DARCO Hg- LH, Norit Americas Inc.) and brominated activated carbon fibers (ACF-Br) (Illinois State Geological Survey and University of Illinois). The AC-Br sorbents...

17

Domain Bubbles of Extra Dimensions  

E-Print Network (OSTI)

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

J. R. Morris

2002-11-19T23:59:59.000Z

18

A computational study of highly viscous impinging jets  

SciTech Connect

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

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

1998-11-01T23:59:59.000Z

19

Vortex Formation in Ellipsoidal Thermal Bubbles  

Science Conference Proceedings (OSTI)

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

Alan Shapiro; Katharine M. Kanak

2002-07-01T23:59:59.000Z

20

Gas Bubbles as Oceanographic Tracers  

Science Conference Proceedings (OSTI)

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

Burkard Baschek; David M. Farmer

2010-01-01T23:59:59.000Z

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


21

LRL 25-inch Bubble Chamber  

DOE R&D Accomplishments (OSTI)

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

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

1964-07-08T23:59:59.000Z

22

Bubble Universe Dynamics After Free Passage  

E-Print Network (OSTI)

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

Pontus Ahlqvist; Kate Eckerle; Brian Greene

2013-10-22T23:59:59.000Z

23

Air entrainment by a plunging jet under intermittent vortex conditions  

E-Print Network (OSTI)

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

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

2011-01-01T23:59:59.000Z

24

BUBBLE MOTION AND SIZE VARIATION DURING THERMAL ...  

Science Conference Proceedings (OSTI)

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

25

Hypervelocity impact jet formation  

SciTech Connect

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

Ang, J.A.

1991-01-01T23:59:59.000Z

26

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

SciTech Connect

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

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

1993-03-01T23:59:59.000Z

27

United States Renewable Energy Technical Potential <br>  

Open Energy Info (EERE)

United States Renewable Energy Technical Potential <br> 2012-07-03T20:56:33Z 2012-07-19T22:42:54Z I am submitting data from researchers within my organization. To complete the...

28

Bubbles in the Near-Surface Ocean: Their Various Structures  

Science Conference Proceedings (OSTI)

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

Jin Wu

1994-09-01T23:59:59.000Z

29

Fluid mechanics of bubble capture by the diving bell spider  

E-Print Network (OSTI)

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

Brooks, Alice (Alice P.)

2010-01-01T23:59:59.000Z

30

Optical Measurement of Bubbles: System Design and Application  

Science Conference Proceedings (OSTI)

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

Ira Leifer; Gerrit de Leeuw; Leo H. Cohen

2003-09-01T23:59:59.000Z

31

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

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

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

32

Artificial Bubble Cloud Targets for Underwater Acoustic Remote Sensing  

Science Conference Proceedings (OSTI)

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

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

1995-12-01T23:59:59.000Z

33

Air Bubbles Produced by Breaking Wind Waves: A Laboratory Study  

Science Conference Proceedings (OSTI)

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

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

1990-01-01T23:59:59.000Z

34

Large Scale Simulations of Jets in Dense and Magnetised Environments  

E-Print Network (OSTI)

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

Martin G. H. Krause; Max Camenzind

2003-07-08T23:59:59.000Z

35

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

Science Conference Proceedings (OSTI)

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

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

2012-10-15T23:59:59.000Z

36

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

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

37

The Effect of Bubbles on Internal Waves  

Science Conference Proceedings (OSTI)

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

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

2004-02-01T23:59:59.000Z

38

Math of Popping Bubbles in a Foam  

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

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

39

The ATLAS jet trigger  

E-Print Network (OSTI)

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

Tamsett, M; The ATLAS collaboration

2012-01-01T23:59:59.000Z

40

Jet Mass Spectra in Higgs + One Jet at NNLL  

E-Print Network (OSTI)

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

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

2013-02-04T23:59:59.000Z

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


41

MAGNETIC TOPOLOGY OF BUBBLES IN QUIESCENT PROMINENCES  

Science Conference Proceedings (OSTI)

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

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

2012-12-10T23:59:59.000Z

42

FastJet user manual  

E-Print Network (OSTI)

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

Matteo Cacciari; Gavin P. Salam; Gregory Soyez

2011-11-25T23:59:59.000Z

43

Scattering of Ultra Cold Neutrons on Nano-size Bubbles  

E-Print Network (OSTI)

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

Vladimir Gudkov

2006-02-07T23:59:59.000Z

44

Diffusive Accumulation of Methane Bubbles in Seabed  

E-Print Network (OSTI)

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

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

2010-01-01T23:59:59.000Z

45

Jet production at HERA  

E-Print Network (OSTI)

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

C. Glasman

2004-10-07T23:59:59.000Z

46

Bubble Behavior in a Taylor Vortex  

E-Print Network (OSTI)

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

Deng, Rensheng

47

Searches for charmed particles using bubble chambers  

SciTech Connect

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

Harris, R.

1975-10-01T23:59:59.000Z

48

Nucleate boiling bubble growth and departure  

E-Print Network (OSTI)

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

Staniszewski, Bogumil E.

1959-01-01T23:59:59.000Z

49

Acoustic Energy Storage in Single Bubble Sonoluminescence  

E-Print Network (OSTI)

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

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

1996-05-07T23:59:59.000Z

50

Jet Quenching at LHC  

E-Print Network (OSTI)

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

Martin Spousta

2013-05-28T23:59:59.000Z

51

Angular Scaling In Jets  

SciTech Connect

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

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

2012-02-17T23:59:59.000Z

52

Jets with Variable R  

E-Print Network (OSTI)

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

David Krohn; Jesse Thaler; Lian-Tao Wang

2009-03-02T23:59:59.000Z

53

Electron sources utilizing thin CsBr coatings  

Science Conference Proceedings (OSTI)

We present experimental results obtained in solid Cu targets coated with ~18nm thick CsBr films operating in a reflection mode. The results indicate a factor of 50X increase in quantum efficiency relative to uncoated Cu samples. The CsBr/Cu samples are ... Keywords: Alkali halides, CsBr, Electron sources, Free electron lasers, Multi electron beam tools, Photocathodes

Juan R. Maldonado; Zhi Liu; D. H. Dowell; Robert E. Kirby; Yun Sun; Piero Pianetta; Fabian Pease

2009-04-01T23:59:59.000Z

54

Microstructure, morphology and lifetime of armored bubbles exposed to surfactants  

E-Print Network (OSTI)

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

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

2006-02-16T23:59:59.000Z

55

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

SciTech Connect

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

Weber, J., Mei, J.

2012-01-01T23:59:59.000Z

56

Compressibility Consideration in the Boundary of a Strongly Collapsing Bubble  

E-Print Network (OSTI)

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

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

2003-01-01T23:59:59.000Z

57

Bubble Clouds and Langmuir Circulation: Observations and Models  

Science Conference Proceedings (OSTI)

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

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

2003-09-01T23:59:59.000Z

58

Some Factors Affecting the Size Distributions of Oceanic Bubbles  

Science Conference Proceedings (OSTI)

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

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

1992-04-01T23:59:59.000Z

59

Stability of a class of neutral vacuum bubbles  

E-Print Network (OSTI)

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

J. R. Morris

2013-04-16T23:59:59.000Z

60

Heart-shaped bubbles rising in anisotropic liquids  

Science Conference Proceedings (OSTI)

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

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

2007-01-01T23:59:59.000Z

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


61

Bubble visualization in a simulated hydraulic jump  

E-Print Network (OSTI)

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

Witt, Adam; Shen, Lian

2013-01-01T23:59:59.000Z

62

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

E-Print Network (OSTI)

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

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

2004-10-01T23:59:59.000Z

63

Particle production by the expanding thin-walled bubble  

E-Print Network (OSTI)

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

Michael Maziashvili

2003-11-27T23:59:59.000Z

64

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

DOE Green Energy (OSTI)

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

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

2010-11-01T23:59:59.000Z

65

Jet Fuel from Microalgal Lipids  

DOE Green Energy (OSTI)

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

Not Available

2006-07-01T23:59:59.000Z

66

Organic vapor jet printing system  

DOE Patents (OSTI)

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

Forrest, Stephen R

2012-10-23T23:59:59.000Z

67

Effects of Bulk Viscosity in Non-linear Bubble Dynamics  

E-Print Network (OSTI)

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

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

2003-01-01T23:59:59.000Z

68

Fresh Equatorial Jets  

Science Conference Proceedings (OSTI)

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

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

1994-03-01T23:59:59.000Z

69

Biofuels – Jet fuel  

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

70

High energy XeBr electric discharge laser  

DOE Patents (OSTI)

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*.

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

1981-01-01T23:59:59.000Z

71

Flow cytometer jet monitor system  

DOE Patents (OSTI)

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

Van den Engh, Ger (Seattle, WA)

1997-01-01T23:59:59.000Z

72

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

DOE Green Energy (OSTI)

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

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

1984-09-01T23:59:59.000Z

73

Dissolution Arrest and Stability of Armored Bubbles  

E-Print Network (OSTI)

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

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

2007-03-25T23:59:59.000Z

74

Experimental characterisation of bubbly flow using MRI  

E-Print Network (OSTI)

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

Tayler, Alexander B.

2011-11-08T23:59:59.000Z

75

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

Science Conference Proceedings (OSTI)

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

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

1986-01-01T23:59:59.000Z

76

Jet initiation of PBX 9502  

SciTech Connect

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

McAfee, J.M.

1987-07-01T23:59:59.000Z

77

Bubble coalescence dynamics and supersaturation in electrolytic gas evolution  

SciTech Connect

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

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

1996-08-01T23:59:59.000Z

78

Photon + jets at D0  

E-Print Network (OSTI)

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

Lars Sonnenschein

2009-06-15T23:59:59.000Z

79

Ultrasound Removing Oxygen Gas Bubbles on Anode and ...  

Science Conference Proceedings (OSTI)

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

80

Bubble Pump Design for Single Pressure Absorption Refrigeration Cycles  

E-Print Network (OSTI)

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

Sam V. Shelton; Susan White Stewart

2002-01-01T23:59:59.000Z

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


81

Simulation of Rising Bubbles Dynamics Using the Lattice Boltzmann Method.  

E-Print Network (OSTI)

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

Ngachin, Merlin

2011-01-01T23:59:59.000Z

82

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

Science Conference Proceedings (OSTI)

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

83

The hydrogen bubble chamber and the strange resonances  

SciTech Connect

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

Alvarez, L.W.

1985-06-01T23:59:59.000Z

84

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

Science Conference Proceedings (OSTI)

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

85

The hydrogen bubble chamber and the strange resonances  

DOE Green Energy (OSTI)

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

Alvarez, L.W.

1985-06-01T23:59:59.000Z

86

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

Office of Scientific and Technical Information (OSTI)

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

87

The Fundamentals of Gas Bubbling into Liquid Metals  

Science Conference Proceedings (OSTI)

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

88

Variability of Southern Ocean Jets Near Topography  

Science Conference Proceedings (OSTI)

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

Christopher C. Chapman; Rosemary Morrow

89

Air Entrainment Processes and Bubble Size Distributions in the Surf Zone  

Science Conference Proceedings (OSTI)

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

Grant B. Deane; M. Dale Stokes

1999-07-01T23:59:59.000Z

90

Shroud for a submerged jet cutting nozzle  

DOE Patents (OSTI)

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

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

1978-01-01T23:59:59.000Z

91

Interferometric Visualization of Jet Flames  

Science Conference Proceedings (OSTI)

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

A. Stella; G. Guj; A. Mataloni

2000-01-01T23:59:59.000Z

92

Jet quenching and heavy quarks  

E-Print Network (OSTI)

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

Thorsten Renk

2013-09-12T23:59:59.000Z

93

Destabilization of Neutron Stars by Type I Dimension Bubbles  

E-Print Network (OSTI)

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

E. I. Guendelman; J. R. Morris

2005-01-16T23:59:59.000Z

94

Mechanisms of stability of armored bubbles: FY 1996 Final Report  

SciTech Connect

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

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

1996-11-01T23:59:59.000Z

95

Impact of tangled magnetic fields on AGN-blown bubbles  

E-Print Network (OSTI)

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

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

2007-03-30T23:59:59.000Z

96

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

DOE Green Energy (OSTI)

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

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

2010-09-01T23:59:59.000Z

97

Water cooled steam jet  

DOE Patents (OSTI)

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

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

1999-01-01T23:59:59.000Z

98

Jet fuel from LPG  

SciTech Connect

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

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

1983-02-01T23:59:59.000Z

99

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

SciTech Connect

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

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

2000-12-01T23:59:59.000Z

100

Stellar Wind Bubbles: H-Deficient . . .  

E-Print Network (OSTI)

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

G. Mellema

2003-01-01T23:59:59.000Z

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


101

Moduli Vacuum Bubbles Produced by Evaporating Black Holes  

E-Print Network (OSTI)

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

J. R. Morris

2007-08-14T23:59:59.000Z

102

Novel techniques for slurry bubble column hydrodynamics  

Science Conference Proceedings (OSTI)

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

Dudukovic, M.P.

1999-05-14T23:59:59.000Z

103

Measurements of Gas Bubble Size Distributions in Flowing Liquid Mercury  

Science Conference Proceedings (OSTI)

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

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

2012-01-01T23:59:59.000Z

104

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

Science Conference Proceedings (OSTI)

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

Brian F. Farrell; Petros J. Ioannou

2004-11-01T23:59:59.000Z

105

Growing bubbles in a slightly supersaturated liquid solution  

E-Print Network (OSTI)

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

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

2013-01-01T23:59:59.000Z

106

Jet Energy Scale Studies and the Search for the Standard Model Higgs Boson in the Channel ZH -> nu anti-nu b anti-b at D�  

SciTech Connect

The D0 experiment is based at the Tevatron, which is currently the world's highest-energy accelerator. The detector comprises three major subsystems: the tracking system, the calorimeter and the muon detector. Jets, seen in the calorimeter, are the most common product of the proton-proton interactions at 2TeV. This thesis is divided into two parts. The first part focuses on jets and describes the derivation of a jet energy scale using p{bar p} {yields} (Z + jets) events as a cross-check of the official D0 jet energy scale (Versions 4.2 and 5.1) which is derived using p{bar p} {yields} {gamma} + jets events. Closure tests were also carried out on the jet energy calibration as a further verification. Jets from b-quarks are commonly produced at D0, readily identified and are a useful physics tool. These require a special correction in the case where the b-jet decays via a muon and a neutrino. Thus a semileptonic correction was also derived as an addition to the standard energy correction for jets. The search for the Higgs boson is one of the largest physics programs at D0. The second part of this thesis describes a search for the Standard Model Higgs boson in the ZH {yields} {nu}{bar {nu}}b{bar b} channel in 52fb{sup -1} of data. The analysis is based on a sequence of event selection criteria optimized on Monte Carlo event samples that simulate four light Higgs boson masses between 105 GeV and 135 GeV and the main backgrounds. For the first time, the data for the analysis are selected using new acoplanarity triggers and the b-quark jets are selected using the D0 neural net b-jet tagging tool. A limit is set for {sigma}(p{bar p} {yields} ZH) x Br(H {yields} b{bar b}).

Lobo, Lydia Mary Isis; /Imperial Coll., London

2006-11-01T23:59:59.000Z

107

On the breakup of air bubbles in Hele-Shaw cell  

E-Print Network (OSTI)

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

Vladimir Entov; Pavel Etingof

2008-04-30T23:59:59.000Z

108

Plasma jet ignition device  

DOE Patents (OSTI)

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

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

1985-01-15T23:59:59.000Z

109

CsBr/GaN Heterojunction Photoelectron Source  

Science Conference Proceedings (OSTI)

Experimental results on a new CsBr/GaN heterojunction photocathode structure are presented. The results indicate a fourfold improvement in photoyield relative to CsBr/Cr photocathodes. A model is presented based on intraband states in CsBr and electron injection from the GaN (with 1% addition of indium) substrate to explain the observed photoyield enhancement. The photocathode lifetime at high current density (>40 A/cm{sup 2}) is limited by laser heating of the small illuminated area. Calculations are presented for sapphire and diamond substrates, indicating a factor of 20 reduction in temperature for the latter. The results are encouraging for the realization of a high photoyield photocathode operating at high current density with long lifetime.

Maldonado, J.R.; /Stanford U., Elect. Eng. Dept.; Liu, Z.; Sun, Y.; /SLAC, SSRL; Schuetter, S.; /Wisconsin U., Madison; Pianetta, P.; /SLAC, SSRL; Pease, R.F.W.; /Stanford U., Elect. Eng. Dept.

2009-04-30T23:59:59.000Z

110

Jet Performance and Jet Energy Scale Determination at CMS  

Science Conference Proceedings (OSTI)

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

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

2006-10-27T23:59:59.000Z

111

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

Science Conference Proceedings (OSTI)

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

112

Patterns of Bubble Clouds organized by Langmuir Circulation  

Science Conference Proceedings (OSTI)

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

David Farmer; Ming Li

1995-06-01T23:59:59.000Z

113

Effects of interfacial surfactant contamination on bubble gas transfer  

E-Print Network (OSTI)

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

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

2006-01-01T23:59:59.000Z

114

Production Functions of Film Drops by Bursting Bubbles  

Science Conference Proceedings (OSTI)

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

Jin Wu

2001-11-01T23:59:59.000Z

115

The Measurement of Bubble-Size Distributions by Acoustical Backscatter  

Science Conference Proceedings (OSTI)

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

Svein Vagle; David M. Farmer

1992-10-01T23:59:59.000Z

116

Steam bubble collapse, water hammer and piping network response  

E-Print Network (OSTI)

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

Gruel, R.

117

Bubble-induced damping in displacement-driven microfluidic flows  

E-Print Network (OSTI)

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

Lee, Jongho

118

Bubbles Produced by Breaking Waves in Fresh and Salt Waters  

Science Conference Proceedings (OSTI)

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

Jin Wu

2000-07-01T23:59:59.000Z

119

Engineered and Natural Marine Seep, Bubble-Driven Buoyancy Flows  

Science Conference Proceedings (OSTI)

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

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

2009-12-01T23:59:59.000Z

120

The Fermi Bubbles as Starburst Wind Termination Shocks  

E-Print Network (OSTI)

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

Lacki, Brian C

2013-01-01T23:59:59.000Z

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


121

The transition from two phase bubble flow to slug flow  

E-Print Network (OSTI)

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

Radovcich, Nick A.

1962-01-01T23:59:59.000Z

122

Program on Technology Innovation: Sonoluminescence of Nano and Submicron Bubbles  

Science Conference Proceedings (OSTI)

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

2007-03-30T23:59:59.000Z

123

Photon Bubbles and the Vertical Structure of Accretion Disks  

E-Print Network (OSTI)

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

Mitchell C. Begelman

2006-02-01T23:59:59.000Z

124

Calculations of slurry pump jet impingement loads  

SciTech Connect

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

Wu, T.T.

1996-03-04T23:59:59.000Z

125

African Easterly Jet: Structure and Maintenance  

Science Conference Proceedings (OSTI)

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

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

2009-09-01T23:59:59.000Z

126

Eddy Formation in 2½-Layer, Quasigeostrophic Jets  

Science Conference Proceedings (OSTI)

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

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

2002-03-01T23:59:59.000Z

127

Dynamics of the Southern Hemisphere Spiral Jet  

Science Conference Proceedings (OSTI)

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

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

2007-02-01T23:59:59.000Z

128

BioJet Corporation | Open Energy Information  

Open Energy Info (EERE)

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

129

Advanced thermally stable jet fuels  

Science Conference Proceedings (OSTI)

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

Schobert, H.H.

1999-01-31T23:59:59.000Z

130

Inclusive jet production at Tevatron  

Science Conference Proceedings (OSTI)

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

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

1995-07-01T23:59:59.000Z

131

Jet physics at HERA, Tevatron and LHC  

E-Print Network (OSTI)

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

C. Royon

2008-11-10T23:59:59.000Z

132

Inclusive jet production at the Tevatron  

SciTech Connect

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

Norniella, Olga; /Barcelona, IFAE

2006-08-01T23:59:59.000Z

133

Bubble masks for time-encoded imaging of fast neutrons.  

SciTech Connect

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

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

2013-09-01T23:59:59.000Z

134

Production of biocomponent containing jet fuels  

Science Conference Proceedings (OSTI)

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

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

2011-12-01T23:59:59.000Z

135

Tiny Glass Bubbles With Big Potential | Department of Energy  

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

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

136

Micro Bubble Technologies Inc MBT | Open Energy Information  

Open Energy Info (EERE)

Micro Bubble Technologies Inc MBT Micro Bubble Technologies Inc MBT Jump to: navigation, search Name Micro Bubble Technologies, Inc (MBT) Place Barrington, Illinois Sector Carbon Product US-Korean maker of cleaner burning fuel and carbon nanotube batteries. Coordinates 41.740155°, -71.308294° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":41.740155,"lon":-71.308294,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

137

Bubble Acceleration in the Ablative Rayleigh-Taylor Instability  

Science Conference Proceedings (OSTI)

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

Betti, R.; Sanz, J.

2006-11-20T23:59:59.000Z

138

Bubble Acceleration in the Ablative Rayleigh-Taylor Instability  

SciTech Connect

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

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

2006-11-17T23:59:59.000Z

139

Dark matter limits froma 15 kg windowless bubble chamber  

SciTech Connect

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

Szydagis, Matthew Mark; /Chicago U.

2010-12-01T23:59:59.000Z

140

An overview of potential financial bubbles in the US financial markets  

E-Print Network (OSTI)

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

Sadalla, Marco Antonio V. (Marco Antonio Vieira)

2013-01-01T23:59:59.000Z

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


141

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

Science Conference Proceedings (OSTI)

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

Ira Leifer; Ranjan K. Patro; Peter Bowyer

2000-10-01T23:59:59.000Z

142

Bubbles Help Break Energy Storage Record for Lithium Air-Batteries  

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

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

143

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

Science Conference Proceedings (OSTI)

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

144

Homogeneous bubble nucleation predicted by a molecular interaction model  

SciTech Connect

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

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

1991-08-01T23:59:59.000Z

145

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

Science Conference Proceedings (OSTI)

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

H. Y. Wang; F. Dong

2010-01-01T23:59:59.000Z

146

Spatial point pattern analysis applied to bubble nucleation in silicate melts  

Science Conference Proceedings (OSTI)

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

Joanna Mongrain; Jessica F. Larsen

2009-09-01T23:59:59.000Z

147

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

Science Conference Proceedings (OSTI)

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

Chris Garrett; Ming Li; David Farmer

2000-09-01T23:59:59.000Z

148

Beaming and Jets in GRBs  

E-Print Network (OSTI)

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

Sari, R

2000-01-01T23:59:59.000Z

149

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

Science Conference Proceedings (OSTI)

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

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

2008-07-15T23:59:59.000Z

150

Diving decompression models and bubble metrics: Modern computer syntheses  

Science Conference Proceedings (OSTI)

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

B. R. Wienke

2009-04-01T23:59:59.000Z

151

The oil price really is a speculative bubble  

E-Print Network (OSTI)

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

Eckaus, Richard S.

2008-01-01T23:59:59.000Z

152

Molecular dynamics simulation of Li surface erosion and bubble formation  

E-Print Network (OSTI)

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

Harilal, S. S.

153

Aeration Due to Breaking Waves. Part I: Bubble Populations  

Science Conference Proceedings (OSTI)

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

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

2004-05-01T23:59:59.000Z

154

Slow closure of denaturation bubbles in DNA: twist matters  

E-Print Network (OSTI)

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

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

2013-02-07T23:59:59.000Z

155

The ATLAS b-Jet Trigger  

E-Print Network (OSTI)

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

Per Hansson

2011-11-17T23:59:59.000Z

156

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

E-Print Network (OSTI)

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

Ho, Chu Eu

2005-01-01T23:59:59.000Z

157

Increasing jet entrainment, mixing and spreading  

DOE Patents (OSTI)

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

Farrington, R.B.

1994-08-16T23:59:59.000Z

158

Increasing jet entrainment, mixing and spreading  

DOE Patents (OSTI)

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

Farrington, Robert B. (Wheatridge, CO)

1994-01-01T23:59:59.000Z

159

Safe Fluids for Jet Engine Texts  

Science Conference Proceedings (OSTI)

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

2012-08-29T23:59:59.000Z

160

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

Science Conference Proceedings (OSTI)

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

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

1999-05-15T23:59:59.000Z

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


161

Mechanisms of Jet Formation on the Giant Planets  

Science Conference Proceedings (OSTI)

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

Junjun Liu; Tapio Schneider

2010-11-01T23:59:59.000Z

162

SpartyJet 4.0 User's Manual  

E-Print Network (OSTI)

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

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

2012-01-17T23:59:59.000Z

163

Angular Energy Distribution of Collapsar-Jets  

E-Print Network (OSTI)

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

Akira Mizuta; Miguel A. Aloy

2008-12-28T23:59:59.000Z

164

HEFA and F-T jet fuel cost analyses  

E-Print Network (OSTI)

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

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

2012-01-01T23:59:59.000Z

165

Jet Fuel Supply/Price Outlook - Fueling the Recovery  

U.S. Energy Information Administration (EIA)

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

166

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

Science Conference Proceedings (OSTI)

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

167

Electro jet drilling using hybrid NNGA approach  

Science Conference Proceedings (OSTI)

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

Mohan Sen; H. S. Shan

2007-02-01T23:59:59.000Z

168

Formation of Jets by Baroclinic Turbulence  

Science Conference Proceedings (OSTI)

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

Brian F. Farrell; Petros J. Ioannou

2008-11-01T23:59:59.000Z

169

Dynamics of the West African Westerly Jet  

Science Conference Proceedings (OSTI)

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

Bing Pu; Kerry H. Cook

2010-12-01T23:59:59.000Z

170

Inertial Resonance Induced by an Oceanic Jet  

Science Conference Proceedings (OSTI)

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

P. Klein; A. M. Treguier

1993-09-01T23:59:59.000Z

171

Ditau jets in Higgs searches  

SciTech Connect

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

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

2011-10-01T23:59:59.000Z

172

Hypervelocity jets from conical hollow-charges  

Science Conference Proceedings (OSTI)

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

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

1997-04-15T23:59:59.000Z

173

A dichotomy in radio jet orientations  

E-Print Network (OSTI)

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

Gijs Verdoes Kleijn; Tim de Zeeuw

2005-11-30T23:59:59.000Z

174

ENGINEERING DEVELOPMENT OF SLURRY BUBBLE COLUMN REACTOR (SBCR)TECHNOLOGY  

SciTech Connect

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

Bernard A. Toseland, Ph.D

2000-06-01T23:59:59.000Z

175

ENGINEERING DEVELOPMENT OF SLURRY BUBBLE COLUMN REACTOR (SBCR) TECHNOLOGY  

SciTech Connect

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

Bernard A. Toseland, Ph.D.

1999-01-01T23:59:59.000Z

176

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

E-Print Network (OSTI)

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

Narayanan, Vinod

2012-01-01T23:59:59.000Z

177

Apparatus for improving the working time of the XeBr laser  

DOE Patents (OSTI)

In XeBr lasers which make use of HBr as the source of bromine, it has been found that the working life of the laser is limited because of dissociation of the HBr in the lasing region to form H/sub 2/ and Br/sub 2/. Accordingly, apparatus is disclosed for substantially improving the working time of the XeBr laser wherein means are provided for recombining H/sub 2/ and Br/sub 2/ into HBr and for continuously circulating the gaseous working medium from the lasing region through the recombination region.

Sander, R.K.; Balog, G.; Seegmiller, E.T.

1980-03-04T23:59:59.000Z

178

Apparatus for improving the working time of the XeBr laser  

SciTech Connect

In XeBr lasers which make use of HBr as the source of bromine, it has been found that the working life of the laser is limited because of dissociation of the HBr in the lasing region to form H.sub.2 and Br.sub.2. Accordingly, apparatus is disclosed for substantially improving the working time of the XeBr laser wherein means are provided for recombining H.sub.2 and Br.sub.2 into HBr and for continuously circulating the gaseous working medium from the lasing region through the recombination region. BACKGROUND OF THE INVENTION

Sander, Robert K. (Los Alamos, MN); Balog, George (Los Alamos, MN); Seegmiller, Emma T. (Los Alamos, MN)

1982-01-01T23:59:59.000Z

179

Bubble study could improve industrial splash control | Argonne National  

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

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

180

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

E-Print Network (OSTI)

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

Jonathan Granot; Dafne Guetta

2002-11-07T23:59:59.000Z

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


181

Jet Energy Scale Studies and the Search for the Standard Model Higgs Boson in the Channel ZH -> nu anti-nu b anti-b at D�  

SciTech Connect

The D0 experiment is based at the Tevatron, which is currently the world's highest-energy accelerator. The detector comprises three major subsystems: the tracking system, the calorimeter and the muon detector. Jets, seen in the calorimeter, are the most common product of the proton-proton interactions at 2TeV. This thesis is divided into two parts. The first part focuses on jets and describes the derivation of a jet energy scale using p{bar p} {yields} (Z + jets) events as a cross-check of the official D0 jet energy scale (Versions 4.2 and 5.1) which is derived using p{bar p} {yields} {gamma} + jets events. Closure tests were also carried out on the jet energy calibration as a further verification. Jets from b-quarks are commonly produced at D0, readily identified and are a useful physics tool. These require a special correction in the case where the b-jet decays via a muon and a neutrino. Thus a semileptonic correction was also derived as an addition to the standard energy correction for jets. The search for the Higgs boson is one of the largest physics programs at D0. The second part of this thesis describes a search for the Standard Model Higgs boson in the ZH {yields} {nu}{bar {nu}}b{bar b} channel in 52fb{sup -1} of data. The analysis is based on a sequence of event selection criteria optimized on Monte Carlo event samples that simulate four light Higgs boson masses between 105 GeV and 135 GeV and the main backgrounds. For the first time, the data for the analysis are selected using new acoplanarity triggers and the b-quark jets are selected using the D0 neural net b-jet tagging tool. A limit is set for {sigma}(p{bar p} {yields} ZH) x Br(H {yields} b{bar b}).

Lobo, Lydia Mary Isis; /Imperial Coll., London

2006-11-01T23:59:59.000Z

182

Performance of LiAlloy/Ag(2)CrO(4) Couples in Molten CsBr-LiBr-KBr Eutectic  

DOE Green Energy (OSTI)

The performance of Li-alloy/CsBr-LiBr-KBr/Ag{sub 2}CrO{sub 4} systems was studied over a temperature range of 250 C to 300 C, for possible use as a power source for geothermal borehole applications. Single cells were discharged at current densities of 15.8 and 32.6 mA/cm{sup 2} using Li-Si and Li-Al anodes. When tested in 5-cell batteries, the Li-Si/CsBr-LiBr-KBr/Ag{sub 2}CrO{sub 4} system exhibited thermal runaway. Thermal analytical tests showed that the Ag{sub 2}CrO{sub 4} cathode reacted exothermically with the electrolyte on activation. Consequently, this system would not be practical for the envisioned geothermal borehole applications.

GUIDOTTI,RONALD A.; REINHARDT,FREDERICK W.

1999-10-18T23:59:59.000Z

183

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

E-Print Network (OSTI)

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

Bum-Hoon Lee; Dong-han Yeom

2011-11-01T23:59:59.000Z

184

Composite Octet Searches with Jet Substructure  

Science Conference Proceedings (OSTI)

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

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

2012-02-14T23:59:59.000Z

185

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

Science Conference Proceedings (OSTI)

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

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

2010-01-01T23:59:59.000Z

186

Numerical Simulations of Boiling Jet Impingement Cooling in Power Electronics  

DOE Green Energy (OSTI)

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

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

2006-12-01T23:59:59.000Z

187

THE RHIC HYDROGEN JET LUMINESCENCE MONITOR.  

DOE Green Energy (OSTI)

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

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

2007-06-25T23:59:59.000Z

188

Jet spoiler arrangement for wind turbine  

DOE Patents (OSTI)

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

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

1985-01-01T23:59:59.000Z

189

Jet spoiler arrangement for wind turbine  

DOE Patents (OSTI)

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

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

1983-09-15T23:59:59.000Z

190

Study of falling-jet flash evaporators  

DOE Green Energy (OSTI)

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

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

1982-11-01T23:59:59.000Z

191

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

E-Print Network (OSTI)

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

J. R. Morris

2004-05-21T23:59:59.000Z

192

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

E-Print Network (OSTI)

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

Shi, Shuping

2011-01-01T23:59:59.000Z

193

Jet production in muon scattering at Fermilab E665  

SciTech Connect

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

Salgado, C.W.; E665 Collaboration

1993-11-01T23:59:59.000Z

194

Stochastic Dynamics of the Midlatitude Atmospheric Jet  

Science Conference Proceedings (OSTI)

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

Brian F. Farrell; Peteros J. Ioannou

1995-05-01T23:59:59.000Z

195

Jets (relativistic and non) in astrophysics  

E-Print Network (OSTI)

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

Foschini, Luigi

2010-01-01T23:59:59.000Z

196

String model for spinning quark jets  

Science Conference Proceedings (OSTI)

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

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

2012-06-27T23:59:59.000Z

197

Mixing Processes within the Polar Night Jet  

Science Conference Proceedings (OSTI)

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

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

1994-10-01T23:59:59.000Z

198

Internal shocks model for microquasar jets  

E-Print Network (OSTI)

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

Omar Jamil; Rob Fender; Christian Kaiser

2008-11-20T23:59:59.000Z

199

Jet Fuel from Bio-Diesel  

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

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

200

Current-driven instability of magnetic jets  

E-Print Network (OSTI)

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

Bonanno, Alfio

2010-01-01T23:59:59.000Z

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


201

The Initial Composition of Jet Condensation Trails  

Science Conference Proceedings (OSTI)

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

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

1996-11-01T23:59:59.000Z

202

Persistent Multiple Jets and PV Staircase  

Science Conference Proceedings (OSTI)

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

Changhyun Yoo; Sukyoung Lee

2010-07-01T23:59:59.000Z

203

Developments of the ATLAS Jet Trigger  

E-Print Network (OSTI)

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

Lopes, L; The ATLAS collaboration

2012-01-01T23:59:59.000Z

204

Performance of the ATLAS Jet Trigger  

E-Print Network (OSTI)

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

Lopes, L; The ATLAS collaboration

2012-01-01T23:59:59.000Z

205

New results on jet fragmentation at CDF  

SciTech Connect

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

Jindariani, Sergo; /Florida U.

2006-12-01T23:59:59.000Z

206

Dark Matter Jets at the LHC  

SciTech Connect

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

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

2012-03-28T23:59:59.000Z

207

Heat transfer investigations in a slurry bubble column  

SciTech Connect

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

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

1991-02-01T23:59:59.000Z

208

Helix untwisting and bubble formation in circular DNA  

E-Print Network (OSTI)

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

Zoli, Marco

2013-01-01T23:59:59.000Z

209

Fast Magnetic Reconnection in Laser-Produced Plasma Bubbles  

SciTech Connect

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

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

2011-05-27T23:59:59.000Z

210

Supersonic Jet Excitation using Flapping Injection  

E-Print Network (OSTI)

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

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

2013-01-01T23:59:59.000Z

211

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

U.S. Energy Information Administration (EIA)

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

212

Characterization of the LiSi/CsBr-LiBr-KBr/FeS(2) System for Potential Use as a Geothermal Borehole Power Source  

DOE Green Energy (OSTI)

We are continuing to study the suitability of modified thermal-battery technology as a potential power source for geothermal borehole applications. Previous work focused on the LiSi/FeS{sub 2} couple over a temperature range of 350 C to 400 C with the LiBr-KBr-LiF eutectic, which melts at 324.5 C. In this work, the discharge processes that take place in LiSi/CsBr-LiBr-KBr eutectic/FeS{sub 2} thermal cells were studied at temperatures between 250 C and 400 C using pelletized cells with immobilized electrolyte. The CsBr-LiBr-KBr eutectic was selected because of its lower melting point (228.5 C). Incorporation of a quasi-reference electrode allowed the determination of the relative contribution of each electrode to the overall cell polarization. The results of single-cell tests and limited battery tests are presented, along with preliminary data for battery stacks tested in a simulated geothermal borehole environment.

GUIDOTTI, RONALD A.; REINHARDT, FREDERICK W.

1999-10-18T23:59:59.000Z

213

Jet energy scale determination in the D0 experiment  

E-Print Network (OSTI)

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

D0 Collaboration

2013-12-24T23:59:59.000Z

214

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

E-Print Network (OSTI)

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

Joseph, Daniel D.

215

Hydrodynamic simulation of air bubble implosion using a level set approach  

Science Conference Proceedings (OSTI)

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

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

2006-06-01T23:59:59.000Z

216

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

E-Print Network (OSTI)

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

Recanati, Catherine

217

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

Science Conference Proceedings (OSTI)

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

Peter Bowyer; David Woolf

2004-12-01T23:59:59.000Z

218

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

E-Print Network (OSTI)

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

Zha, Gecheng

219

CO observation of the Galactic bubble N4  

E-Print Network (OSTI)

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

Li, Junyu; Liu, Yao; Wang, Yuan

2013-01-01T23:59:59.000Z

220

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

DOE Green Energy (OSTI)

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

Terrones, Guillermo; Gauglitz, Phillip A.

2002-03-01T23:59:59.000Z

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


221

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

Science Conference Proceedings (OSTI)

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

Edward G. Josberger

1980-03-01T23:59:59.000Z

222

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

Science Conference Proceedings (OSTI)

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

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

2006-03-02T23:59:59.000Z

223

ON THE STRUCTURE AND STABILITY OF MAGNETIC TOWER JETS  

SciTech Connect

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

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

2012-09-20T23:59:59.000Z

224

COMPUTATIONAL AND EXPERIMENTAL MODELING OF SLURRY BUBBLE COLUMN REACTORS  

Science Conference Proceedings (OSTI)

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

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

2002-05-01T23:59:59.000Z

225

High energy emission from galactic jets  

E-Print Network (OSTI)

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

H. R. Christiansen

2013-06-07T23:59:59.000Z

226

Jet physics from static charges in AdS space  

E-Print Network (OSTI)

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

Stewart, Iain

227

The Dynamical Relationship between Subtropical and Eddy-Driven Jets  

Science Conference Proceedings (OSTI)

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

Sukyoung Lee; Hyun-kyung Kim

2003-06-01T23:59:59.000Z

228

Recirculation Gyres Forced by a Beta-Plane Jet  

Science Conference Proceedings (OSTI)

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

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

1996-04-01T23:59:59.000Z

229

Jet Jumping: Low-Frequency Variability in the Southern Ocean  

Science Conference Proceedings (OSTI)

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

Christopher C. Chapman; Andrew McC. Hogg

2013-05-01T23:59:59.000Z

230

Formation of Jets and Equatorial Superrotation on Jupiter  

Science Conference Proceedings (OSTI)

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

Tapio Schneider; Junjun Liu

2009-03-01T23:59:59.000Z

231

Optimized Parameters for a Mercury Jet Target  

Science Conference Proceedings (OSTI)

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

Ding, X.; Kirk, H.

2010-12-01T23:59:59.000Z

232

LAKESHORE AVON BR ANT-EDEN ALD EN-LANC ASTER AU BURN W SH ELDON  

U.S. Energy Information Administration (EIA) Indexed Site

81 81 § ¨ ¦ 81 LAKESHORE AVON BR ANT-EDEN ALD EN-LANC ASTER AU BURN W SH ELDON CALEDONIA HURON C REEK LEIC EST ER COL DEN ASH FORD INDIAN FALLS LAWTONS SAR DINIA RPD-037 -2 GLENWOOD PU LASKI PAVILION CON CORD COL LINS N ELM A ORC HARD PARK-H AMBU RG DANLEY CORNERS ST ILLWAT ER CHAFF EE-ARCAD E FAYETT E-WATERLOO LAKEVIEW JAVA SEN EC A W ELLER Y AU RORA E ZOAR BU FFALO TIOGA SILVER LAKE AKR ON ROM E RAT HBON E ALM A BET HANY WYOMING ULYSSES BR ANCH W SAN DY CREEK COL LINS BLOOMFIELD E LEBANON STATE LINE ALLEN CHUR CHVILLE BATH ATT ICA ELLI COT VILLE ROU LETT E BR ADFORD BU FFALO CREEK PEN N YAN N BEECH HILL-INDEPENDENC E GERRY-CH ARLOTTE STAGECOACH CHIPMUN K HEBRON VIN CENT BALD WI NSVILLE AKELEY OLEAN COWLESVILLE AN NIN SMET HPORT BR ADLEY BR OOK BU STI FIVE MILE BLOOMFIELD W SEN EC A FALLS NILE STAGECOACH LEWIS R UN BR ADFORD CAMDEN VAN ETT EN ROAN OKE SH ARON RICHBU RG FULTON N FINN EGAN H ILL TONAWANDA

233

Bubbles, Jumps, and Scaling from Properly Anticipated Prices  

E-Print Network (OSTI)

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

Patzelt, Felix

2013-01-01T23:59:59.000Z

234

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

SciTech Connect

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

Isaac K. Gamwo; Dimitri Gidaspow

1999-09-01T23:59:59.000Z

235

Centrifugally driven electrostatic instability in extragalactic jets  

SciTech Connect

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

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

2008-03-15T23:59:59.000Z

236

Gamma-Ray Bursts: Jets and Energetics  

E-Print Network (OSTI)

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

D. A. Frail

2003-11-12T23:59:59.000Z

237

Gravity waves from vortex dipoles and jets  

E-Print Network (OSTI)

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

Wang, Shuguang

2008-08-01T23:59:59.000Z

238

Enhancement of wall jet transport properties  

DOE Patents (OSTI)

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

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

1997-01-01T23:59:59.000Z

239

High pressure water jet mining machine  

DOE Patents (OSTI)

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

Barker, Clark R. (Rolla, MO)

1981-05-05T23:59:59.000Z

240

The Cambridge Jet algorithm: features and applications  

E-Print Network (OSTI)

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

Stan Bentvelsen; Irmtraud Meyer

1998-03-12T23:59:59.000Z

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


241

COMPUTATIONAL AND EXPERIMENTAL MODELING OF SLURRY BUBBLE COLUMN REACTORS  

SciTech Connect

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

Paul Lam; Dimitri Gidaspow

2000-09-01T23:59:59.000Z

242

Jets and the hadronic final state at HERA  

E-Print Network (OSTI)

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

T. Schoerner-Sadenius

2004-10-07T23:59:59.000Z

243

Photon - Jet Correlations and Constraints on Fragmentation Functions  

E-Print Network (OSTI)

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

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

2009-03-27T23:59:59.000Z

244

On the Counter-jet Emission in GRB Afterglows  

Science Conference Proceedings (OSTI)

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

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

2010-10-15T23:59:59.000Z

245

Gauge/gravity duality and jets in strongly coupled plasma  

E-Print Network (OSTI)

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

Chesler, Paul M

2009-01-01T23:59:59.000Z

246

Gauge/gravity duality and jets in strongly coupled plasma  

E-Print Network (OSTI)

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

Paul M. Chesler

2009-07-26T23:59:59.000Z

247

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

U.S. Energy Information Administration (EIA)

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

248

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

U.S. Energy Information Administration (EIA)

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

249

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

E-Print Network (OSTI)

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

Paris-Sud XI, Université de

250

Structure and Spacing of Jets in Barotropic Turbulence  

Science Conference Proceedings (OSTI)

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

Brian F. Farrell; Petros J. Ioannou

2007-10-01T23:59:59.000Z

251

Jet pump feeds corrosion inhibitor in Russian waterflood  

SciTech Connect

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

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

1997-01-27T23:59:59.000Z

252

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

SciTech Connect

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

Hang, T.

2000-07-19T23:59:59.000Z

253

Studying Z/gamma*+Jet Production  

SciTech Connect

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

Nilsen, Henrik Wold; /Freiburg U.

2009-07-01T23:59:59.000Z

254

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

Science Conference Proceedings (OSTI)

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

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

2003-03-01T23:59:59.000Z

255

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

Science Conference Proceedings (OSTI)

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

Joanna E. Muench; Eric Kunze

2000-08-01T23:59:59.000Z

256

Gluon Polarization and Jet Production at STAR  

Science Conference Proceedings (OSTI)

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

Pibero Djawotho; the STAR Collaboration

2009-01-01T23:59:59.000Z

257

HOT ELECTROMAGNETIC OUTFLOWS. II. JET BREAKOUT  

Science Conference Proceedings (OSTI)

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

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

2013-08-20T23:59:59.000Z

258

Online b-jets tagging at CDF  

Science Conference Proceedings (OSTI)

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

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

2007-04-01T23:59:59.000Z

259

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

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

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

260

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

Science Conference Proceedings (OSTI)

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

Ji Yeon Park; Sungil Lim; Kihong Park

2014-01-01T23:59:59.000Z

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


261

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

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

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

262

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

Open Energy Info (EERE)

Bubbles Hot Spring Pool & Spa Low Temperature Geothermal Facility Bubbles Hot Spring Pool & Spa Low Temperature Geothermal Facility Jump to: navigation, search Name Bubbles Hot Spring Pool & Spa Low Temperature Geothermal Facility Facility Bubbles Hot Spring Sector Geothermal energy Type Pool and Spa Location Catron County, New Mexico Coordinates 34.1515173°, -108.4276047° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[]}

263

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

Science Conference Proceedings (OSTI)

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

André Robert

1993-07-01T23:59:59.000Z

264

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

Science Conference Proceedings (OSTI)

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

Petr Chýlek; Gorden Videen; Dat Ngo

1998-02-01T23:59:59.000Z

265

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

E-Print Network (OSTI)

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

Rosenberg, Michael Jonathan

266

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

Science Conference Proceedings (OSTI)

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

Edgar L. Andreas; Edward C. Monahan

2000-02-01T23:59:59.000Z

267

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

E-Print Network (OSTI)

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

Leifer, Ira; Culling, Daniel

2010-01-01T23:59:59.000Z

268

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

Science Conference Proceedings (OSTI)

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

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

1998-10-01T23:59:59.000Z

269

Molecular dynamics simulation of deuterium trapping and bubble formation in tungsten  

E-Print Network (OSTI)

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

Harilal, S. S.

270

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

E-Print Network (OSTI)

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

Ida, M

2001-01-01T23:59:59.000Z

271

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

Science Conference Proceedings (OSTI)

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

Wenli Zhou; Sanping Wan; Chao Zhu

2009-01-01T23:59:59.000Z

272

Bubble behavior in subcooled flow boiling on surfaces of variable wettability  

E-Print Network (OSTI)

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

Tow, Emily W

2012-01-01T23:59:59.000Z

273

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

Science Conference Proceedings (OSTI)

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

S. A. Thorpe

1986-08-01T23:59:59.000Z

274

Magnetized and collimated millimeter scale plasma jets with astrophysical relevance  

Science Conference Proceedings (OSTI)

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

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

2012-01-15T23:59:59.000Z

275

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

E-Print Network (OSTI)

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

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

2012-06-30T23:59:59.000Z

276

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

E-Print Network (OSTI)

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

Roger Botton; Dominique Cosserat; Souhila Poncin; Gabriel Wild

2009-01-01T23:59:59.000Z

277

Radiation Effects on Transport and Bubble Formation in Silicate Glasses  

DOE Green Energy (OSTI)

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

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

2001-12-31T23:59:59.000Z

278

PROBING THE ROSETTE NEBULA STELLAR BUBBLE WITH FARADAY ROTATION  

SciTech Connect

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

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

2013-03-01T23:59:59.000Z

279

Experimental characterization of slurry bubble-column reactor hydrodynamics  

DOE Green Energy (OSTI)

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

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

1997-09-01T23:59:59.000Z

280

Cometabolic degradation of trichloroethylene in a bubble column bioscrubber  

SciTech Connect

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

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

1995-08-20T23:59:59.000Z

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


281

Transmission Line Analogy for Relativistic Poynting-Flux Jets  

E-Print Network (OSTI)

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

Lovelace, R V E

2012-01-01T23:59:59.000Z

282

Cryogenic target formation using cold gas jets  

DOE Patents (OSTI)

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

Hendricks, C.D.

1980-02-26T23:59:59.000Z

283

ON THE ORIGIN OF INTERGRANULAR JETS  

SciTech Connect

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

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

2011-08-01T23:59:59.000Z

284

Event-by-event jet quenching  

SciTech Connect

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

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

2010-08-14T23:59:59.000Z

285

Ejector device for direct injection fuel jet  

SciTech Connect

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

Upatnieks, Ansis (Livermore, CA)

2006-05-30T23:59:59.000Z

286

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

SciTech Connect

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

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

2012-05-30T23:59:59.000Z

287

Atomistic model of helium bubbles in gallium-stabilized plutonium alloys  

Science Conference Proceedings (OSTI)

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

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

2006-06-01T23:59:59.000Z

288

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

E-Print Network (OSTI)

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

Kalaikadal, Deepak Saagar

2012-01-01T23:59:59.000Z

289

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

E-Print Network (OSTI)

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

Sebastian Heinz

2005-09-26T23:59:59.000Z

290

A BUBBLING NEARBY MOLECULAR CLOUD: COMPLETE SHELLS IN PERSEUS  

SciTech Connect

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

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

2011-12-01T23:59:59.000Z

291

Dynamics of quasi-two-dimensional turbulent jets  

E-Print Network (OSTI)

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

Landel, Julien Rémy Dominique Gérard

2012-11-13T23:59:59.000Z

292

MEASURING THE JET POWER OF FLAT-SPECTRUM RADIO QUASARS  

SciTech Connect

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

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

2012-09-10T23:59:59.000Z

293

Neutralization of H/sup -/ beams with gas jets  

DOE Green Energy (OSTI)

A test facility was constructed to create a compact curtain-shaped gas jet as a first-generation operational neutralizer for the 150 keV H/sup -/ beam. Different gases and vapors were considered, their optimum target thicknesses and neutralization efficiencies with respect to beam energies were explored. Two techniques of gas jet formation were compared. Multiparallel-channel effusive jets of CO/sub 2/ and H/sub 2/ were selected as test candidates.

Lam, C.K.

1977-01-01T23:59:59.000Z

294

Injection Molding of Tungsten Powder Treated by Jet Mill  

Science Conference Proceedings (OSTI)

Tungsten powder was firstly treated by jet mill, resulting in the improvement of ... and Welding Conditions of Monopile and Transition for Offshore Wind Plant.

295

Thermal Behavior of a Hot Moving Steel Plate during Jet ...  

Science Conference Proceedings (OSTI)

Presentation Title, Thermal Behavior of a Hot Moving Steel Plate during Jet Impingement Cooling. Author(s), Amir Hossein Nobari, Vladan Prodanovic, ...

296

Simulations of Jets Driven by Black Hole Rotation  

E-Print Network (OSTI)

The origin of jets emitted from black holes is not well understood, however there are two possible energy sources, the accretion disk or the rotating black hole. Magnetohydrodynamic simulations show a well-defined jet that extracts energy from a black hole. If plasma near the black hole is threaded by large-scale magnetic flux, it will rotate with respect to asymptotic infinity creating large magnetic stresses. These stresses are released as a relativistic jet at the expense of black hole rotational energy. The physics of the jet initiation in the simulations is described by the theory of black hole gravitohydromagnetics.

Vladimir Semenov; Sergey Dyadechkin; Brian Punsly

2004-08-20T23:59:59.000Z

297

Idaho Kerosene-Type Jet Fuel Retail Sales by Refiners ...  

U.S. Energy Information Administration (EIA)

Referring Pages: Idaho Kerosene-Type Jet Fuel Refiner Sales Volumes; Idaho Sales to End Users Refiner Sales Volumes of Aviation Fuels, Kerosene, ...

298

Shattering Kraft Recovery Boiler Smelt by a Steam Jet.  

E-Print Network (OSTI)

??Kraft recovery boiler smelt is shattered into small droplets by an impinging steam jet to prevent smelt-water explosions in the dissolving tank. Inadequate shattering increases… (more)

Taranenko, Anton

2013-01-01T23:59:59.000Z

299

Electronic spectroscopy of jet-cooled combustion radicals. Final report  

Science Conference Proceedings (OSTI)

Jet-cooled spectra of 1-methylvinoxy and 2-methylvinoxy are reported and analyzed with help from high-level electronic structure calculations.

Weisshaar, James C.

2002-03-11T23:59:59.000Z

300

Relativistic Poynting-Flux Jets as Transmission Lines  

E-Print Network (OSTI)

Recent radio emission, polarization, and Faraday rotation maps of the radio jet of the galaxy 3C 303 have shown that one knot of this jet has a {\\it galactic}-scale electric current of $\\sim 3\\times 10^{18}$ Amp\\`ere flowing along the jet axis (Kronberg et al. 2011). We develop the theory of relativistic Poynting-flux jets which are modeled as a transmission line carrying a DC current $I_0$, having a potential drop $V_0$, and a definite impedance ${\\cal Z}_0 =90(u_z/c)\\Omega$, where $u_z$ is the bulk velocity of the jet plasma. The electromagnetic energy flow in the jet is ${\\cal Z}_0 I_0^2$. The observed current in 3C 303 can be used to calculate the electromagnetic energy flow in this magnetically dominated jet. Time-dependent but not necessarily small perturbations of a Poynting-flux jet - possibly triggered by a gas cloud penetrating the jet - are described by "telegrapher's equations," which predict the propagation speed of disturbances and the effective wave impedance ${\\cal Z}$. The disturbance of a Po...

Lovelace, R V E; Kronberg, P P

2012-01-01T23:59:59.000Z

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301

COLLIMATION AND CONFINEMENT OF MAGNETIC JETS BY EXTERNAL MEDIA  

Science Conference Proceedings (OSTI)

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.

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

302

An alternative model of jet suppression at RHIC energies  

E-Print Network (OSTI)

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.

Roman Lietava; Jan Pisut; Neva Pisutova; Boris Tomasik

2003-01-16T23:59:59.000Z

303

Environmental and economic assessment of microalgae-derived jet fuel  

E-Print Network (OSTI)

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 ...

Carter, Nicholas Aaron

2012-01-01T23:59:59.000Z

304

U.S. Refinery Catalytic Hydrotreating, Kerosene/Jet Fuel ...  

U.S. Energy Information Administration (EIA)

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

305

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

Science Conference Proceedings (OSTI)

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

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

2010-12-15T23:59:59.000Z

306

Nucleation kinetics of vapor bubbles in a liquid with arbitrary viscosity  

E-Print Network (OSTI)

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

Nikolay V. Alekseechkin

2013-02-21T23:59:59.000Z

307

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

SciTech Connect

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

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

2010-11-15T23:59:59.000Z

308

Measurement of b-quark Jet Shapes at CDF  

SciTech Connect

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.

Lister, Alison; /Zurich, ETH

2006-03-01T23:59:59.000Z

309

PowerJet Wind Turbine Project  

SciTech Connect

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

Bartlett, Raymond J

2008-11-30T23:59:59.000Z

310

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

Science Conference Proceedings (OSTI)

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

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

2012-11-01T23:59:59.000Z

311

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

DOE Green Energy (OSTI)

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

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

1997-12-31T23:59:59.000Z

312

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

E-Print Network (OSTI)

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

Caprini, Chiara; Servant, Géraldine

2008-01-01T23:59:59.000Z

313

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

E-Print Network (OSTI)

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

Chiara Caprini; Ruth Durrer; Geraldine Servant

2007-11-16T23:59:59.000Z

314

Radiant Energy Power Source for Jet Aircraft  

DOE Green Energy (OSTI)

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.

Doellner, O.L.

1992-02-01T23:59:59.000Z

315

Two jet energy and rapidity distributions  

SciTech Connect

The D0 detector has been recording data at the Tevatron [bar p]p Collider since May 1992. Because the D0 calorimeter is hermetic and has large acceptance it is well suited for semi-exclusive final state jet studies. We present a primary measurement of the distribution d[sup 3]N/dE[sub t1]/d[eta][sub 1]/d[eta][sub 2] at [radical]s TeV over a large range of [eta]. The sensitivity of this cross-section to parton momentum distributions and the ability of D0 to discriminate between possible parton distributions is discussed.

Blazey, G.C.

1992-11-01T23:59:59.000Z

316

Infrared safe definition of jet flavor.  

E-Print Network (OSTI)

(energy) and collinear (angular) divergence. For flavour algorithms one should remember that the matrix elements for g ? qq¯ or q ? qg (with a soft quark) have no soft divergence, but just the collinear divergence, [dkj]|M2g?qiq¯j(kj)| ? ?sTR 2? dEj Ei d?2... energy larger than 1TeV and the two hardest jets to have |?| < 1. Three representative channels, qq ? qq (including qq¯ ? qq¯), qq¯ ? gg and qg ? qg are shown in fig. 6, as obtained with Herwig [15]. The standard parton showering in Pythia [23] gives...

Banfi, Andrea; Salam, Gavin P; Zanderighi, Giulia

317

Searches in photon and jet states  

SciTech Connect

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.

Soha, A.; /UC, Davis

2007-06-01T23:59:59.000Z

318

W+3 jet production at the Tevatron  

E-Print Network (OSTI)

We compute the next-to-leading order QCD corrections to the production of W bosons in association with three jets at the Tevatron in the leading color approximation, which we define by considering the number of colors and the number of light flavors as being of the same order of magnitude. The theoretical uncertainty in the next-to-leading order prediction for the cross-section is of the order of 15-25 percent which is a significant improvement compared to the leading order result.

Ellis, R Keith; Zanderighi, Giulia

2009-01-01T23:59:59.000Z

319

W+3 jet production at the Tevatron  

E-Print Network (OSTI)

We compute the next-to-leading order QCD corrections to the production of W bosons in association with three jets at the Tevatron in the leading color approximation, which we define by considering the number of colors and the number of light flavors as being of the same order of magnitude. The theoretical uncertainty in the next-to-leading order prediction for the cross-section is of the order of 15-25 percent which is a significant improvement compared to the leading order result.

R. Keith Ellis; Kirill Melnikov; Giulia Zanderighi

2009-06-08T23:59:59.000Z

320

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

Science Conference Proceedings (OSTI)

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

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

2010-01-01T23:59:59.000Z

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


321

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

DOE Green Energy (OSTI)

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

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

1997-10-01T23:59:59.000Z

322

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

Science Conference Proceedings (OSTI)

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

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

2012-12-21T23:59:59.000Z

323

Missouri Kerosene-Type Jet Fuel Wholesale/Resale Volume by ...  

U.S. Energy Information Administration (EIA)

Referring Pages: Kerosene-Type Jet Fuel Sales for Resale Refiner Sales Volumes; Missouri Kerosene-Type Jet Fuel Refiner Sales Volumes; Missouri Sales for Resale ...

324

New Mexico Kerosene-Type Jet Fuel Wholesale/Resale Volume by ...  

U.S. Energy Information Administration (EIA)

Referring Pages: Kerosene-Type Jet Fuel Sales for Resale Refiner Sales Volumes; New Mexico Kerosene-Type Jet Fuel Refiner Sales Volumes; New Mexico Sales for Resale ...

325

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

E-Print Network (OSTI)

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

Ravinuthala, Sharad Chand

2013-01-01T23:59:59.000Z

326

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

Science Conference Proceedings (OSTI)

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

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

2012-08-15T23:59:59.000Z

327

Synchrotron Radiation from a Laser Plasma Accelerator in the Bubble Regime  

Science Conference Proceedings (OSTI)

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

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

2010-11-04T23:59:59.000Z

328

Higgs Boson Production in Association with Three Jets  

E-Print Network (OSTI)

The scattering amplitudes for Higgs + 5 partons are computed, with the Higgs boson produced via gluon fusion in the large top-quark mass limit. A parton-level analysis of Higgs + 3 jet production via gluon fusion and via weak-boson fusion is presented, and the effectiveness of a central-jet veto is analysed.

V. Del Duca; A. Frizzo; F. Maltoni

2004-04-01T23:59:59.000Z

329

On the Disintegration of the Jet in a Plunging Breaker  

Science Conference Proceedings (OSTI)

An inviscid mechanism is proposed for the breakup of the jet in a plunging surface wave. Streamwise perturbations of the original surface are shown to grow rapidly owing to stretching of the thin jet and to drastic reduction in the normal ...

Michael Longuet-Higgins

1995-10-01T23:59:59.000Z

330

Gravity waves excited by jets: Propagation versus generation R. Plougonven  

E-Print Network (OSTI)

Gravity waves excited by jets: Propagation versus generation R. Plougonven School of Mathematics September 2005. [1] Atmospheric jets are known to be an important source of inertia-gravity waves, yet mechanisms for the gravity waves, with the underlying assumption that the characteristics of the waves were

Plougonven, Riwal

331

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

332

Finite element analysis of the electro jet drilling process  

Science Conference Proceedings (OSTI)

The electro jet drilling (EJD) process is gaining prominence in the machining of micro and macro holes in difficult-to-machine materials used in aerospace, electronics and computers, medical, and automobile industries. As the trend towards miniaturization ... Keywords: electro jet drilling, electrochemical drilling, finite element method, radial overcut

M. Sen; H. S. Shan

2007-01-01T23:59:59.000Z

333

Jet engine's speed controller with constant pressure chamber  

Science Conference Proceedings (OSTI)

The paper deals with an automatic system meant to control a jet engine's rotation speed, through the fuel injection's control, based on a constant pressure chamber controller. One has established the non-linear mathematical model (based on the motion ... Keywords: actuator, control, fuel injection, fuel pump, jet-engine, pressure chamber

Alexandru Nicolae Tudosie

2008-06-01T23:59:59.000Z

334

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

SciTech Connect

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

Kono, H.O.

1991-01-01T23:59:59.000Z

335

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

Science Conference Proceedings (OSTI)

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

Kono, H.O.

1991-01-01T23:59:59.000Z

336

Ammonia chemistry in a flameless jet  

Science Conference Proceedings (OSTI)

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

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

2009-10-15T23:59:59.000Z

337

NETL: News Release - Jet Engine Successful in Fighting Mine Fire  

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

2, 2003 2, 2003 Jet Engine Successful in Fighting Mine Fire Energy Department's Assistance Brings West Virginia Coal Miners Back To Work One Year Early - Australian Jet Engine Successfully Fights West Virginia Mine Fire - By blowing its exhaust into the underground mine, the modified jet engine was able to snuff out the mine fire much faster than traditional methods. FAIRVIEW, WV - A modified jet engine has been used to successfully fight a West Virginia mine fire that had been burning for nearly two months and was the cause of 300 employees being temporarily laid off when mine operations were idled. Positioned at the mouth of the one of the mineshafts, the jet engine was used to blow water vapor and inert gases into the mine to smother the fire by creating an inert environment underground. It was the

338

Inductive and Electrostatic Acceleration in Relativistic Jet-Plasma Interactions  

Science Conference Proceedings (OSTI)

We report on the observation of rapid particle acceleration in numerical simulations of relativistic jet-plasma interactions and discuss the underlying mechanisms. The dynamics of a charge-neutral, narrow, electron-positron jet propagating through an unmagnetized electron-ion plasma was investigated using a three-dimensional, electromagnetic, particle-in-cell computer code. The interaction excited magnetic filamentation as well as electrostatic (longitudinal) plasma instabilities. In some cases, the longitudinal electric fields generated inductively and electrostatically reached the cold plasma wave-breaking limit, and the longitudinal momentum of about half the positrons increased by 50% with a maximum gain exceeding a factor of two. The results are relevant to understanding the micro-physics at the interface region of an astrophysical jet with the interstellar plasma, for example, the edge of a wide jet or the jet-termination point.

Ng, Johnny S.T.; Noble, Robert J.; /SLAC

2005-07-13T23:59:59.000Z

339

Open cycle OTEC system with falling jet evaporator and condenser  

DOE Green Energy (OSTI)

A configuration for the open cycle (OC) Ocean Thermal Energy Conversion (OTEC) system is presented incorporating a countercurrent falling jet evaporator and a concurrent falling jet condenser. The parameters governing performance of the proposed configuration are discussed and the sizing of equipment for a 100-MWe net power output OC OTEC plant is performed, based on recent experimental falling jet heat and mass transfer results. The performance of an OC OTEC plant with falling jet evaporator-condenser is compared with the Westinghouse conceptual design that uses an open-channel evaporator and a surface condenser. Preliminary calculations indicate that falling jet heat and mass transfer, when applied in the proposed configuration, leads to a very simple and compact plant assembly resulting in substantial capital cost savings.

Kogan, A.; Johnson, D. H.; Green, H. J.; Olson, D. A.

1980-07-01T23:59:59.000Z

340

The evolution of magnetic tower jets in the laboratory  

E-Print Network (OSTI)

The evolution of laboratory produced magnetic jets is followed numerically through three-dimensional, non-ideal magnetohydrodynamic simulations. The experiments are designed to study the interaction of a purely toroidal field with an extended plasma background medium. The system is observed to evolve into a structure consisting of an approximately cylindrical magnetic cavity with an embedded magnetically confined jet on its axis. The supersonic expansion produces a shell of swept-up shocked plasma which surrounds and partially confines the magnetic tower. Currents initially flow along the walls of the cavity and in the jet but the development of current-driven instabilities leads to the disruption of the jet and a re-arrangement of the field and currents. The top of the cavity breaks-up and a well collimated, radiatively cooled, 'clumpy' jet emerges from the system.

A. Ciardi; S. V. Lebedev; A. Frank; E. G. Blackman; J. P. Chittenden; C. J. Jennings; D. J. Ampleford; S. N. Bland; S. C. Bott; J. Rapley; G. N. Hall; F. A. Suzuki-Vidal; A. Marocchino; T. Lery; C. Stehle

2006-11-14T23:59:59.000Z

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


341

Gravitational Wave Memory of Gamma-Ray Burst Jets  

E-Print Network (OSTI)

Gamma-Ray Bursts (GRBs) are now considered as relativistic jets. We analyze the gravitational waves from the acceleration stage of the GRB jets. We show that (i) the point mass approximation is not appropriate if the opening half-angle of the jet is larger than the inverse of the Lorentz factor of the jet, (ii) the gravitational waveform has many step function like jumps, and (iii) the practical DECIGO and BBO may detect such an event if the GRBs occur in Local group of galaxy. We found that the light curve of GRBs and the gravitational waveform are anti-correlated so that the detection of the gravitational wave is indispensable to determine the structure of GRB jets.

Norichika Sago; Kunihito Ioka; Takashi Nakamura; Ryo Yamazaki

2004-05-13T23:59:59.000Z

342

Measurement of jet multiplicity in top pair events  

E-Print Network (OSTI)

The normalized differential $t\\bar t$ cross section in jet multiplicity bins is presented, measured in proton-proton collisions using 5.0~fb$^{-1}$ of data collected at $\\sqrt{s}$ = 7~\\TeV. The analysis is performed in the electron + jets and the muon + jets channels. The jet multiplicity distribution is sensitive to initial state radiation. A comparison of the data with different Monte Carlo generators is shown. After background subtraction, the data are in agreement with $t\\bar t$ signal Monte Carlo distributions. Additionally, the measurement of the top quark pair differential cross-section in the number of radiated additional hard partons in the muon + jets channel is presented. The measured fractions of events with $t\\bar t$ + 0, 1, and $\\geq$ 2 additional partons are in good agreement with different Monte Carlo predictions.

CMS Collaboration

2012-01-01T23:59:59.000Z

343

Br-rich Tips of Calcified Crab Claws are Less Hard but More Fracture  

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

Br-rich Tips of Calcified Crab Claws are Br-rich Tips of Calcified Crab Claws are Less Hard but More Fracture Resistant: A Comparison of Mineralized and Heavy-element Biological Materials figure 1 Figure 1. The heavy element biomaterial is the darker material at the tip of the shore crab claws. Figure "b" shows the same claw as "a" but after bead blasting. The claw tips are less eroded by the bead blasting than surrounding calcified material, suggesting a greater resistance to chipping from impact. Scale bar: 2mm Invertebrates modify their jaws, claws, carapaces and other mechanical structures with a variety of inorganic materials. One of the best-known examples is the calcified cuticle of crabs. We have found that many crabs also employ an uncalcified bromine-rich biological material at the tips of

344

Acid Placement in Acid Jetting Treatments in Long Horizontal Wells  

E-Print Network (OSTI)

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 is withdrawn from the well. The jetting action helps to remove the drilling fluid filter cake and promote the acid to penetrate into the formation and form wormholes to stimulate the well. However, with very long sections of wellbore open to flow, the acid placement and subsequent wormhole distribution and penetration depths are uncertain. This study has modeled the acid jetting process using a comprehensive model of acid placement and wormhole propagation in a horizontal well. It is presumed that the acid jetting tool removes the drilling mud filter cake, so that no filter cake exists between the end of the drill pipe and the toe of the well. Correspondingly, the model also assumes that there is an intact, low-permeability filter cake on the borehole wall between the end of the drill pipe and the heel of the well. The drill pipe is modeled as being withdrawn from the well during the acid jetting treatment, as is done in practice. The acidizing simulator predicts the distribution of acid and the depths of wormholes formed as functions of time and position during the acid jetting treatment. The model shows that the acid jetting process as typically applied in these wells preferentially stimulates the toe region of the horizontal well. Comparisons of the simulation predictions with published data for acid jetting treatments in such wells showed good general agreement. Based on the simulation study, this study presents recommendations for improved acid jetting treatment procedures to improve the distribution of acid injected into the formation.

Sasongko, Hari

2012-05-01T23:59:59.000Z

345

jet-compressible-gas-july25.tex 1 Liquid jet in a high Mach number air stream  

E-Print Network (OSTI)

jet-compressible-gas-july25.tex 1 Liquid jet in a high Mach number air stream T.Funada, D velocity airstream is studied assuming that the flow of the viscous gas and liquid is irrotational for the perturbations which depend on all the material properties of the incompressible liquid and compressible gas

Joseph, Daniel D.

346

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

Science Conference Proceedings (OSTI)

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.

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

2011-06-22T23:59:59.000Z

347

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

Open Energy Info (EERE)

Brady Hot Springs Geothermal Area Brady Hot Springs Geothermal Area Northwest Basin and Range Geothermal Region MW K Coso Geothermal Area Coso Geothermal Area Walker Lane...

348

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

Science Conference Proceedings (OSTI)

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.

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

349

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

E-Print Network (OSTI)

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

Cubaud, Thomas

350

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

E-Print Network (OSTI)

We use high-speed X-ray phase-contrast imaging, weakly nonlinear analysis and boundary integral simulations to characterize the final stage of underwater bubble break-up. The X-ray imaging study shows that an initial azimuthal perturbation to the shape of the bubble neck gives rise to oscillations that increasingly distort the cross-section shape. These oscillations terminate in a pinch-off where the bubble surface develops concave regions that contact similar to what occurs when two liquid drops coalesce. We also present a weakly nonlinear analysis that shows that this coalescence-like mode of pinch-off occurs when the initial shape oscillation interferes constructively with the higher harmonics it generates and thus reinforce each other's effects in bringing about bubble break-up. Finally we present numerical results that confirm the weakly nonlinear analysis scenario as well as provide insight into observed shape reversals. They demonstrate that when the oscillations interfere destructively, a qualitativel...

Lai, Lipeng; Fezzaa, Kamel; Zhang, Wendy W; Nagel, Sidney R

2013-01-01T23:59:59.000Z

351

Can Propagation of Gas Bubbles Lead to Detached Solidification? Experiments on Freezing of Water  

E-Print Network (OSTI)

. The ampoules were ap- proximately 30-cm long and were filled to about 12 cm with water. The heater velocity versus heater temperature. The water was saturated with air and the ampoule was coated with TeflonCan Propagation of Gas Bubbles Lead to Detached Solidification? Experiments on Freezing of Water

Regel, Liya L.

352

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

SciTech Connect

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

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

1995-07-01T23:59:59.000Z

353

FARADAY ROTATION DISTRIBUTIONS FROM STELLAR MAGNETISM IN WIND-BLOWN BUBBLES  

SciTech Connect

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

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

2013-03-01T23:59:59.000Z

354

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

Science Conference Proceedings (OSTI)

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

Miles, A R

2004-03-18T23:59:59.000Z

355

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

Science Conference Proceedings (OSTI)

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

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

2001-08-01T23:59:59.000Z

356

Measurement of ratio R = (BR(D{sup 0}{yields}K{pi}{pi}{pi})/BR(D{sup 0}{yields}K{pi})) in {pi}{sup -}-Nucleus interactions at 500 GeV/c  

SciTech Connect

We report a very preliminary result on the measurement of the ratio of branching ratios, for two decays D{sup 0} meson, R = (BR(D{sup 0}{yields}K{pi}{pi}{pi})/BR(D{sup 0}{yields}K{pi})), using data from the E791 experiment. We find R = 1.96{+-}0.0286 (stat){+-}0.06 (sys). This is in agreement with and of similar precision to the current PDG average value 1.97{+-}0.09.

Solano Salinas, C. J. [Instituto de Fisica, Universidad Nacional de Ingenieria (Peru); CINVESTAV Merida (Mexico); Paucarchuco, C. [Instituto de Fisica, Universidad Nacional de Ingenieria (Peru); Fernandez, A. [Benemerita Universidad Autonoma de Puebla (Mexico); Sheaff, M. [University of Wisconsin (United States)

2007-10-26T23:59:59.000Z

357

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

SciTech Connect

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

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

2003-08-01T23:59:59.000Z

358

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

Science Conference Proceedings (OSTI)

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

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

2013-01-01T23:59:59.000Z

359

Gas Bubble Trauma Monitoring and Research of Juvenile Salmonids, 1994-1995 Progress Report.  

DOE Green Energy (OSTI)

This report describes laboratory and field monitoring studies of gas bubble trauma (GBT) in migrating juvenile salmonids in the Snake and Columbia rivers. The first chapter describes laboratory studies of the progression of GBT signs leading to mortality and the use of the signs for GBT assessment. The progression and severity of GBT signs in juvenile salmonids exposed to different levels of total dissolved gas (TDG) and temperatures was assessed and quantified. Next, the prevalence, severity, and individual variation of GBT signs was evaluated to attempt to relate them to mortality. Finally, methods for gill examination in fish exposed to high TDG were developed and evaluated. Primary findings were: (1) no single sign of GBT was clearly correlated with mortality, but many GBT signs progressively worsened; (2) both prevalence and severity of GBT signs in several tissues is necessary; (3) bubbles in the lateral line were the earliest sign of GBT, showed progressive worsening, and had low individual variation but may develop poorly during chronic exposures; (4) fin bubbles had high prevalence, progressively worsened, and may be a persistent sign of GBT; and (5) gill bubbles appear to be the proximate cause of death but may only be relevant at high TDG levels and are difficult to examine. Chapter Two describes monitoring results of juvenile salmonids for signs of GBT. Emigrating fish were collected and examined for bubbles in fins and lateral lines. Preliminary findings were: (1) few fish had signs of GBT, but prevalence and severity appeared to increase as fish migrated downstream; (2) there was no apparent correlation between GBT signs in the fins, lateral line, or gills; (3) prevalence and severity of GBT was suggestive of long-term, non-lethal exposure to relatively low level gas supersaturated water; and (4) it appeared that GBT was not a threat to migrating juvenile salmonids. 24 refs., 26 figs., 3 tabs.

Hans, Karen M.

1997-07-01T23:59:59.000Z

360

Efficient Acceleration of Relativistic Magnetohydrodynamic Jets  

E-Print Network (OSTI)

Relativistic jets in active galactic nuclei, galactic microquasars, and gamma-ray bursts are widely considered to be magnetohydrodynamically driven by black hole accretion systems, although conversion mechanism from Poynting into particle kinetic energy flux is still open. Recent detailed numerical and analytical studies of global structures of steady, axisymmetric magnetohydrodynamic (MHD) flows with specific boundary conditions have not reproduced as rapid an energy conversion as required by observations. In order to find more suitable boundary conditions, we focus on the flow along a poloidal magnetic field line just inside the external boundary, without treating transfield force balance in detail. We find some examples of the poloidal field structure and corresponding external pressure profile for an efficient and rapid energy conversion as required by observations, and that the rapid acceleration requires a rapid decrease of the external pressure above the accretion disk. We also clarify the differences ...

Toma, Kenji

2013-01-01T23:59:59.000Z

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361

Two-phase jet loads. [PWR  

Science Conference Proceedings (OSTI)

Two-phase jets are currently being studied to improve engineering models for the prediction of loads on pipes and structures during LOCAs. Multi-dimensional computer codes such as BEACON/MOD2, CSQ, and TRAC-P1A are being employed to predict flow characteristics and flow-structure loading. Our ultimate goal is to develop a new approximate engineering model which is superior to the F.J. Moody design model. Computer results are compared with data obtained from foreign sources, and a technique for using the TRAC-P1A vessel component as a containment model is presented. In general, good agreement with the data is obtained for saturated stagnation conditions; however, difficulties are encountered for subcooled stagnation conditions, possibly due to nucleation delay and non-equilibrium effects.

Tomasko, D.

1980-01-01T23:59:59.000Z

362

CIRCULAR RIBBON FLARES AND HOMOLOGOUS JETS  

SciTech Connect

Solar flare emissions in the chromosphere often appear as elongated ribbons on both sides of the magnetic polarity inversion line (PIL), which has been regarded as evidence of a typical configuration of magnetic reconnection. However, flares having a circular ribbon have rarely been reported, although it is expected in the fan-spine magnetic topology involving reconnection at a three-dimensional (3D) coronal null point. We present five circular ribbon flares with associated surges, using high-resolution and high-cadence H{alpha} blue wing observations obtained from the recently digitized films of Big Bear Solar Observatory. In all the events, a central parasitic magnetic field is encompassed by the opposite polarity, forming a circular PIL traced by filament material. Consequently, a flare kernel at the center is surrounded by a circular flare ribbon. The four homologous jet-related flares on 1991 March 17 and 18 are of particular interest, as (1) the circular ribbons brighten sequentially, with cospatial surges, rather than simultaneously, (2) the central flare kernels show an intriguing 'round-trip' motion and become elongated, and (3) remote brightenings occur at a region with the same magnetic polarity as the central parasitic field and are co-temporal with a separate phase of flare emissions. In another flare on 1991 February 25, the circular flare emission and surge activity occur successively, and the event could be associated with magnetic flux cancellation across the circular PIL. We discuss the implications of these observations combining circular flare ribbons, homologous jets, and remote brightenings for understanding the dynamics of 3D magnetic restructuring.

Wang Haimin; Liu Chang, E-mail: haimin.wang@njit.edu [Space Weather Research Laboratory, Center for Solar-Terrestrial Research, New Jersey Institute of Technology, University Heights, Newark, NJ 07102-1982 (United States)

2012-12-01T23:59:59.000Z

363

TEST PLAN CHARACTERIZATION OF JET FORCES UPON WASTE TANK COMPONENTS  

Science Conference Proceedings (OSTI)

Westinghouse Hanford Company plans to install mixer pumps in double-shell waste tanks to mobilize and suspend settled sludge to allow eventual retrieval for treatment and permanent storage. The mixer pumps produce high momentum, horizontally directed jets that impact and mobilize the sludge and mix it into slurry for removal. There is concern that the force of the jet may damage tank internal components in its path. This test plan describes scaled experiments designed to characterize the velocity profiles of a near floor jet and to quantify the impact farces and drag coefficients of three tank components: radiation dry well, airlift circulator, and steam coil. The experiments will be conducted in water, at approximately 1/6-scale, using one stationary nozzle to simulate the jet. To measure and confirm the velocity profile of the free, submerged jet, the horizontal and vertical velocity profiles will be measured at several distances from the nozzle. The profile will also be measured after the jet impinges upon the tank floor to determine the·extent of the change in the profile caused by impingement. The jet forces upon the test articles will be measured at a maximum of four velocities and a variety of test article orientations. Each orientation will represent a unique position of the test article relative to the jet and the tank floor. In addition, the steam coil will be tested in three rotational orientations because it is not symmetric. The highest jet velocity will be selected so that the Reynolds number of the test article in the model will match that of the prototype when operating at design conditions. The forces measured upon the model components will be used to calculate the force on the prototype components using geometric scaling factors. In addition, the model force measurements will be used to calculate the component's drag coefficient as a function of the component Reynolds number.

Bamberger, J. A.

1992-01-01T23:59:59.000Z

364

Gas bubble retention and its effect on waste properties: Retention mechanisms, viscosity, and tensile and shear strengths  

SciTech Connect

Several of the underground nuclear storage tanks at Hanford have been placed on a flammable gas watch list, because the waste is either known or suspected to generate, store, and episodically release flammable gases. Because retention and episodic release of flammable gases from these tanks containing radioactive waste slurries are critical safety concerns, Pacific Northwest Laboratory (PNL) is studying physical mechanisms and waste properties that contribute to the episodic gas release from these storage tanks. This study is being conducted for Westinghouse Hanford Company as part of the PNL Flammable Gas project. Previous investigations have concluded that gas bubbles are retained by the slurry or sludge that has settled at the bottom of the tanks; however, the mechanisms responsible for the retention of these bubbles are not well understood. Understanding the rheological behavior of the waste, particularly of the settled sludge, is critical to characterizing the tendency of the waste to retain gas bubbles and the dynamics of how these bubbles are released from the waste. The presence of gas bubbles is expected to affect the rheology of the sludge, specifically its viscosity and tensile and shear strengths, but essentially no literature data are available to assess the effect of bubbles. The objectives of this study were to conduct experiments and develop theories to understand better how bubbles are retained by slurries and sludges, to measure the effect of gas bubbles on the viscosity of simulated slurries, and to measure the effect of gas bubbles on the tensile and shear strengths of simulated slurries and sludges. In addition to accomplishing these objectives, this study developed correlations, based on the new experimental data, that can be used in large-scale computations of waste tank physical phenomena.

Gauglitz, P.A.; Rassat, S.D.; Powell, M.R. [and others

1995-08-01T23:59:59.000Z

365

Photon plus Jet Cross Sections at the Tevatron  

E-Print Network (OSTI)

Photon plus jet production has been studied by the D0 and CDF experiments in Run II of the Fermilab Tevatron Collider at a center of mass energy of sqrt{s}=1.96 TeV. Measurements of the inclusive photon plus jet, di-photon and photon plus b jet cross section are presented. They are based on integrated luminosities between 0.2 fb^-1 and 1.1 fb^-1. The results are compared to perturbative QCD calculations in various approximations.

Lars Sonnenschein

2008-04-03T23:59:59.000Z

366

ePLAS Development for Jet Modeling and Applications  

SciTech Connect

Plasma jets provide an alternate approach to the creation of high energy density laboratory plasmas (HEDLP). For the Plasma Liner Experiment (PLX), typically 30 partially ionized argon jets, produced with mini-rail guns, will be focused into a central volume for subsequent magnetic compression into high density plasma liners that can reach high (0.1 Mbar) peak pressures upon stagnation. The jets are typically 2.5 cm in radius traveling at Mach number 30. Ultimate success will require optimized tuning of the rail configurations, the nozzles injecting the gases, and the careful implementation of pre-ionization. The modeling of plasma jet transport is particularly challenging, due the large space (100 sq cm) and time scales (microseconds) involved. Even traditional implicit methods are insufficient, due to the usual need to track electrons explicitly on the mesh. Wall emission and chemistry must be managed, as must ionization of the jet plasma. Ions in the jets are best followed as particles to account properly for collisions upon jet merger. This Phase I Project developed the code ePLAS to attack and successfully surmount many of these challenges. It invented a new 'super implicit' electromagnetic scheme, using implicit electron moment currents that allowed for modeling of jets over multi-cm and multi-picoseconds on standard, single processor 2 GHz PCs. It enabled merger studies of two jets, in preparation for the multi-jet merger problem. The Project explored particle modeling for the ions, and prepared for the future addition of a grid-base jet ion collision model. Access was added to tabular equations of state for the study of ionization effects in merging jets. The improved code was discussed at the primary plasma meetings (IEEE and APS) during the Project period. Collaborations with National Laboratory and industrial partners were nurtured. Code improvements were made to facilitate code use. See: http://www.researchapplicationscorp.com. The ePLAS code enjoys EAR99 export control treatment, permitting distribution to most foreign countries without a license.

Dr. Rodney J. Mason

2011-09-07T23:59:59.000Z

367

On k-jet field approximations of geodesic deviation equations  

E-Print Network (OSTI)

Let M be a smooth manifold and S a spray defined on the convex cone C of the tangent bundle TM. It is proved that the only non-trivial k-jet approximation of the exact geodesic deviation equation of S, linear on the deviation functions and invariant under arbitrary local coordinate transformations corresponds to the Jacobi equation. However, if linearity in the deviation functions is not required, there are differential equations whose solutions admit k-jet approximations and are invariant under arbitrary coordinate transformations. As an example of higher order geodesic deviation equations we study the first and second order jet geodesic deviation equations for a Finsler spray.

Torromé, Ricardo Gallego

2013-01-01T23:59:59.000Z

368

Vibrational, rotational, and isotopic dependence of CaBr X/sup 2/. sigma. spin-rotational and HFS parameters  

Science Conference Proceedings (OSTI)

The previously published molecular-beam, laser-rf, double-resonance study of the rotational and isotopic dependences of the spin-rotational and hyperfine interactions in the v'' = 0, X/sup 2/..sigma.. state of CaBr is supplemented here with data for v''=1. The vibrational dependence of the parameters is now obtained. The results for CaBr are displayed along with analogous, previously published results for CaF and CaCl.

Childs, W.J.; Cok, D.R.; Goodman, L.S.

1982-01-01T23:59:59.000Z

369

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

SciTech Connect

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

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

2005-02-15T23:59:59.000Z

370

The Daytime Evolution of the East African Jet  

Science Conference Proceedings (OSTI)

We present a combined observational and theoretical study of the daytime evolution of the equatorial East African low-level jet stream. During the daytime, as the flow advects from a suppressed marine environment across the East African coastline ...

David M. Rubenstein

1981-01-01T23:59:59.000Z

371

Horizontal and Vertical Structure of the Lake Turkana Jet  

Science Conference Proceedings (OSTI)

An observational study was undertaken at selected sites in north Kenya (Turkana channel) in February 1983 and in June–July 1984 to investigate the horizontal and vertical extent of the Turkana low-level jet. Observations indicate that strong ...

Joseph Hiri Kinuthia

1992-11-01T23:59:59.000Z

372

Jet Formation and Evolution in Baroclinic Turbulence with Simple Topography  

Science Conference Proceedings (OSTI)

Satellite altimetry and high-resolution ocean models indicate that the Southern Ocean comprises an intricate web of narrow, meandering jets that undergo spontaneous formation, merger, and splitting events, as well as rapid latitude shifts over ...

Andrew F. Thompson

2010-02-01T23:59:59.000Z

373

A Newly Found Jet in North Kenya (Turkana Channel)  

Science Conference Proceedings (OSTI)

On the basis of recent pilot balloon observations which have become available in northern Kenya, it is shown that there exists a strong southeasterly low-level jet in the Turkana Channel which separates the Ethiopian Highlands the East African ...

J. H. Kinuthia; G. C. Asnani

1982-11-01T23:59:59.000Z

374

Production of jets at forward rapidities in hadronic collisions  

E-Print Network (OSTI)

We discuss high-pT production processes at forward rapidities in hadron-hadron collisions, and describe recent results from using QCD high-energy factorization in forward jet production at the LHC.

F. Hautmann

2009-09-07T23:59:59.000Z

375

Tracking Gravity Waves in Baroclinic Jet-Front Systems  

Science Conference Proceedings (OSTI)

Using a two-dimensional Fourier decomposition and a four-dimensional ray-tracing technique, the propagating characteristics and source mechanisms of mesoscale gravity waves simulated in idealized baroclinic jet-front systems are investigated. The ...

Yonghui Lin; Fuqing Zhang

2008-07-01T23:59:59.000Z

376

The Effect of Jet-Streak Curvature on Kinematic Fields  

Science Conference Proceedings (OSTI)

A simple two-layer primitive equation (PE) model is used to study the effect of curvature on jet-streak kinematics, specifically vertical motion. Three types of vertical motion are studied: kinematic (PE) vertical motion, quasigeostrophic (QG) ...

James T. Moore; Glenn E. Vanknowe

1992-11-01T23:59:59.000Z

377

Desalination of seawater using a high-efficiency jet ejector  

E-Print Network (OSTI)

The ability to produce potable water economically is the primary focus of seawater desalination research. There are numerous methods to desalinate water, including reverse osmosis, multi-stage flash distillation, and multi-effect evaporation. These methods cost more than potable water produced from natural resources; hence an attempt is made in this research project to produce potable water using a modified high-efficiency jet ejector in vapor-compression distillation. The greater efficiency of the jet ejector is achieved by properly mixing propelled and motive streams. From experiments conducted using air, the pressure rise across the jet ejector is better in case of one or two mixing vanes and the highest back pressure (pinch valve closed 83.33%). At other pinch valve closings, the air velocity through the jet ejector was high, so the extra surface area from the mixing vanes caused excessive friction and lowered the efficiency.

Vishwanathappa, Manohar D.

2003-05-01T23:59:59.000Z

378

The reduction of supersonic jet noise using pulsed microjet injection  

E-Print Network (OSTI)

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 ...

Ragaller, Paul Aaron

2007-01-01T23:59:59.000Z

379

Jet Stream Winds: Comparisons of Aircraft Observations with Analyses  

Science Conference Proceedings (OSTI)

Wind measurements have been obtained from commercial aircraft crossing the 1992 winter subtropical jet streams over southwest and east Asia. Comparisons of these data with new, high-resolution analyses from four of the major operational centers ...

J. Tenenbaum

1996-06-01T23:59:59.000Z

380

Exhaust-gas measurements from NASAs HYMETS arc jet.  

Science Conference Proceedings (OSTI)

Arc-jet wind tunnels produce conditions simulating high-altitude hypersonic flight such as occurs upon entry of space craft into planetary atmospheres. They have traditionally been used to study flight in Earth's atmosphere, which consists mostly of nitrogen and oxygen. NASA is presently using arc jets to study entry into Mars' atmosphere, which consists of carbon dioxide and nitrogen. In both cases, a wide variety of chemical reactions take place among the gas constituents and with test articles placed in the flow. In support of those studies, we made measurements using a residual gas analyzer (RGA) that sampled the exhaust stream of a NASA arc jet. The experiments were conducted at the HYMETS arc jet (Hypersonic Materials Environmental Test System) located at the NASA Langley Research Center, Hampton, VA. This report describes our RGA measurements, which are intended to be used for model validation in combination with similar measurements on other systems.

Miller, Paul Albert

2010-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "br jet bubbling" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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381

GRAVITATIONAL WAVES OF JET PRECESSION IN GAMMA-RAY BURSTS  

SciTech Connect

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.

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

382

Divergent Barotropic Instability of the Tropical Asymmetric Easterly Jet  

Science Conference Proceedings (OSTI)

The divergent barotropic instability of a zonally averaged, observed, tropical, upper tropospheric, monsoon easterly jet is investigated by numerical integration of a linear spectral model. The Rossby radius of deformation for the upper ...

S. K. Mishra; D. Subrahmanyam; M. K. Tandon

1981-10-01T23:59:59.000Z

383

Jet Structure and Scaling in Southern Ocean Models  

Science Conference Proceedings (OSTI)

The jet structure of the Antarctic Circumpolar Current (ACC) simulated by two general circulation models (GCMs), FRAM (Fine Resolution Antarctic Model) and POP (Parallel Ocean Program), is examined in relation to the bottom topography field. ...

B. Sinha; K. J. Richards

1999-06-01T23:59:59.000Z

384

A Transect of the Southern Circumpolar Jet Stream  

Science Conference Proceedings (OSTI)

Aitken nuclei and ozone concentrations were measured, in concert with meteorological variables, while flying beneath the core of a jet stream at the 400 mb level. Stratospheric air which subsided to the flight level was richer in ozone, but ...

A. W. Hogan

1981-10-01T23:59:59.000Z

385

Lagrangian Motion and Fluid Exchange in a Barotropic Meandering Jet  

Science Conference Proceedings (OSTI)

Kinematic models predict that a coherent structure, such as a jet or an eddy, in an unsteady flow can exchange fluid with its surroundings. The authors consider the significance of this effect for a fully nonlinear, dynamically consistent, ...

A. M. Rogerson; P. D. Miller; L. J. Pratt; C. K. R. T. Jones

1999-10-01T23:59:59.000Z

386

Ooishi's Observation: Viewed in the Context of Jet Stream Discovery  

Science Conference Proceedings (OSTI)

Although aircraft encounters with strong westerly winds during World War II provided the stimulus for postwar research on the jet stream, Wasaburo Ooishi observed these winds in the 1920s. Ooishi's work is reviewed in the context of earlier work ...

John M. Lewis

2003-03-01T23:59:59.000Z

387

Computer modeling of jet mixing in INEL waste tanks  

SciTech Connect

The objective of this study is to examine the feasibility of using submerged jet mixing pumps to mobilize and suspend settled sludge materials in INEL High Level Radioactive Waste Tanks. Scenarios include removing the heel (a shallow liquid and sludge layer remaining after tank emptying processes) and mobilizing and suspending solids in full or partially full tanks. The approach used was to (1) briefly review jet mixing theory, (2) review erosion literature in order to identify and estimate important sludge characterization parameters (3) perform computer modeling of submerged liquid mixing jets in INEL tank geometries, (4) develop analytical models from which pump operating conditions and mixing times can be estimated, and (5) analyze model results to determine overall feasibility of using jet mixing pumps and make design recommendations.

Meyer, P.A.

1994-01-01T23:59:59.000Z

388

University of Michigan-Flint Turbo Jet Engine  

E-Print Network (OSTI)

University of Michigan-Flint Turbo Jet Engine Leon LaVene III, Steven Skorski Michael Isaac, Kyle Stokes & Quamrul Mazumder Assistant Professor, Mechanical Engineering University of Michigan-Flint Flint

Farmer, Michael E.

389

Method and apparatus for water jet drilling of rock  

DOE Patents (OSTI)

Rock drilling method and apparatus utilizing high pressure water jets for drilling holes of relatively small diameter at speeds significantly greater than that attainable with existing drilling tools. Greatly increased drilling rates are attained due to jet nozzle geometry and speed of rotation. The jet nozzle design has two orifices, one pointing axially ahead in the direction of travel and the second inclined at an angle of approximately 30.degree. from the axis. The two orifices have diameters in the ratio of approximately 1:2. Liquid jet velocities in excess of 1,000 ft/sec are used, and the nozzle is rotated at speeds up to 1,000 rpm and higher.

Summers, David A. (Rolla, MO); Mazurkiewicz, Marian (Wroclaw, PL); Bushnell, Dwight J. (Corvallis, OR); Blaine, James (Rolla, MO)

1978-01-01T23:59:59.000Z

390

JET physics in support of ITER: Results and future work  

Science Conference Proceedings (OSTI)

The JET Programme to 1999 concentrates on issues that must be solved before a decision to construct ITER can be taken. The paper discusses three areas representative of the physics support provided: confinement studies

M. Keilhacker; and the JET Team

1995-01-01T23:59:59.000Z

391

Geographic Area Month Aviation Gasoline Kerosene-Type Jet Fuel  

Gasoline and Diesel Fuel Update (EIA)

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

392

Horizontal Divergence Associated with Zonally Isolated Jet Streams  

Science Conference Proceedings (OSTI)

Horizontal divergence in the upper troposphere associated with zonally isolated jet streams in the climatological-mean fold for the Northern Hemisphere winter is examined by using the wind fields obtained from the NMC operational analyses in the ...

Hisashi Nakamura

1993-07-01T23:59:59.000Z

393

A critical review of world jet transport safety  

E-Print Network (OSTI)

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 ...

Achtmann, Eric D.

1995-01-01T23:59:59.000Z

394

Control of flames by tangential jet actuators in oxy-fuel burners  

Science Conference Proceedings (OSTI)

The active control of oxy-fuel flames from burners with separated jets is investigated. The control system consists of four small jet actuators, placed tangential to the exit of the main jets to generate a swirling flow. These actuators are able to modify the flow structure and to act on mixing between the reactants and consequently on the flame behavior. The burner (25 kW) is composed of separated jets, one jet of natural gas and one or two jets of pure oxygen. Experiments are conducted with three burner configurations, according to the number of jets, the jet exit velocities, and the separation distance between the jets. OH chemiluminescence measurements, particle image velocimetry, and measurements of NO{sub x} emissions are used to characterize the flow and the flame structure. Results show that the small jet actuators have a significant influence on the behavior of jets and the flame characteristics, particularly in the stabilization zone. It is shown that the control leads to a decrease in lift-off heights and to better stability of the flame. The use of jet actuators induces high jet spreading and an increase in turbulence intensity, which improves the mixing between the reactants and the surrounding fluid. Pollutant measurements show important results in terms of NO{sub x} reductions (up to 60%), in particular for low swirl intensity. The burner parameters, such as the number of jets and the spacing between the jets, also impact the flame behavior and NO{sub x} formation. (author)

Boushaki, Toufik [CORIA UMR 6614 CNRS-Universite et INSA de ROUEN, Site Universitaire du Madrillet, 76801 Saint Etienne du Rouvray, Cedex (France); Universite de Toulouse-INPT-UPS, IMFT (Institut de Mecanique des Fluides de Toulouse), Allee Camille Soula, F-31400 Toulouse, Cedex (France); Sautet, Jean-Charles [CORIA UMR 6614 CNRS-Universite et INSA de ROUEN, Site Universitaire du Madrillet, 76801 Saint Etienne du Rouvray, Cedex (France); Labegorre, Bernard [Air Liquide, Centre de Recherche Claude-Delorme, Les Loges-en-Josas, B.P. 126 78354 Jouy-en-Josas, Cedex (France)

2009-11-15T23:59:59.000Z

395

Jet Production in Polarized pp Collisions at RHIC  

E-Print Network (OSTI)

The STAR Collaboration has measured the longitudinal double-spin asymmetry for inclusive jet production in polarized p+p collisions at sqrt{s} = 200 GeV. The results set significant new constraints on the gluon polarization within the nucleon. Future measurements of asymmetries for di-jet production will provide direct access to the momentum dependence of the gluon polarization, Delta g(x,Q^2).

C. A. Gagliardi; for the STAR Collaboration

2008-08-06T23:59:59.000Z

396

Very Light Jets I. Axisymmetric Parameter Study and Analytic Approximation  

E-Print Network (OSTI)

The propagation of extragalactic jets is studied by a series of twelve axisymmetric hydrodynamic simulations. Motivated by observational constraints, but unlike most previous simulations, the regime of jet to external medium density (eta) from 10^-5 to 10^-2 is explored, for Mach numbers (M) between 2.6 and 26. The computational domain contained the bow shocks for the whole simulation time. The bow shocks are found to be spherical at source sizes below a critical value r1 (blastwave phase), which can reach up to 10 jet radii. [...] The numerical work is complemented by an analytic approach for the spherical phase. Extending previous work, the radial force balance could be integrated for arbitrary background density and energy input, which results in a global solution. The analytic results are shown to be consistent with the numerical work, and a lower limit to r1 can be calculated, which falls below the numerical results by a few jet radii. It is shown explicitely how a King density distribution changes the discussed aspects of the bow shock propagation. Because the jet head propagates very fast in the blastwave phase, it turns out that it is not possible to ``frustrate'' a jet by a high density environment. This is very important for the class of small radio galaxies (compact symmetric objects / GHz peaked sources): They have to be young. During its blastwave phase, a powerful jet can transfer typically 10^60 erg to the environmental gas. This is enough to balance the radiative losses in a cooling flow, if one of the cluster galaxies harbours a powerful jet every Gigayear.

Martin Krause

2002-11-20T23:59:59.000Z

397

Spin density distribution in CrCl/sub 3/ and CrBr/sub 3/  

SciTech Connect

The magnetization distribution in the layered ionic compounds CrCl/sub 3/ and CrBr/sub 3/ has been studied using polarized neutron diffraction. The results show that in both compounds approx. 20% of the magnetic moment is not located in 3d- like orbitals centered on the chromium ions. This reduction of the 3d moment sets a lower limit (A/sub ..pi..//sup 2/ > .04) on the square of the covalent admixture parameter. The spatial distribution of the delocalized moment has been studied by Fourier techniques which indicate a significant moment density between chromium ions in the chromium layers.

Brown, P.J.; Ziebeck, K.R.A.; Radhakrishna, P.

1982-01-01T23:59:59.000Z

398

Operation features of a longitudinal-capacitive-discharge-pumped CuBr laser  

Science Conference Proceedings (OSTI)

The frequency and energy characteristics of a capacitive-discharge-pumped CuBr laser are investigated. Processes proceeding in the discharge circuit of lasers pumped in this way, in particular, pumped without an external storage capacitor are analysed. It is shown that, depending on the pumping circuit, laser levels are excited either during the charge current flow or during the discharge of electrode capacitances. The differences in the influence of the active HBr addition on the characteristics of the discharge and lasing compared to the case of a usual repetitively pulsed high-current discharge with internal electrodes are established. (lasers)

Gubarev, F A; Shiyanov, D V [V.E. Zuev Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, Tomsk (Russian Federation); Evtushenko, Gennadii S [Tomsk Polytechnical University, Tomsk (Russian Federation); Sukhanov, V B

2010-01-31T23:59:59.000Z

399

A RECOLLIMATION SHOCK 80 mas FROM THE CORE IN THE JET OF THE RADIO GALAXY 3C 120: OBSERVATIONAL EVIDENCE AND MODELING  

Science Conference Proceedings (OSTI)

We present Very Long Baseline Array observations of the radio galaxy 3C 120 at 5, 8, 12, and 15 GHz designed to study a peculiar stationary jet feature (hereafter C80) located {approx}80 mas from the core, which was previously shown to display a brightness temperature {approx}600 times larger than expected at such distances. The high sensitivity of the images-obtained between 2009 December and 2010 June-has revealed that C80 corresponds to the eastern flux density peak of an arc of emission (hereafter A80), downstream of which extends a large ({approx}20 mas in size) bubble-like structure that resembles an inverted bow shock. The linearly polarized emission closely follows that of the total intensity in A80, with the electric vector position angle distributed nearly perpendicular to the arc-shaped structure. Despite the stationary nature of C80/A80, superluminal components with speeds up to 3 {+-} 1 c have been detected downstream from its position, resembling the behavior observed in the HST-1 emission complex in M87. The total and polarized emission of the C80/A80 structure, its lack of motion, and brightness temperature excess are best reproduced by a model based on synchrotron emission from a conical shock with cone opening angle {eta} = 10 Degree-Sign , jet viewing angle {theta} = 16 Degree-Sign , a completely tangled upstream magnetic field, and upstream Lorentz factor {gamma}{sub u} = 8.4. The good agreement between our observations and numerical modeling leads us to conclude that the peculiar feature associated with C80/A80 corresponds to a conical recollimation shock in the jet of 3C 120 located at a de-projected distance of {approx}190 pc downstream from the nucleus.

Agudo, Ivan; Gomez, Jose L.; Casadio, Carolina; Roca-Sogorb, Mar [Instituto de Astrofisica de Andalucia, CSIC, Apartado 3004, 18080 Granada (Spain); Cawthorne, Timothy V., E-mail: jlgomez@iaa.es [School of Computing, Engineering and Physical Science, University of Central Lancashire, Preston PR1 2HE (United Kingdom)

2012-06-20T23:59:59.000Z

400

Minkowski's Object: A Starburst Triggered by a Radio Jet, Revisited  

DOE Green Energy (OSTI)

We present neutral hydrogen, ultraviolet, optical and near-infrared imaging, as well as optical spectroscopic observations of Minkowski's Object (MO), a star forming system at the end of a radio jet associated with NGC541 at the center of a cluster of galaxies, Abell 194. The observations strengthen the evidence, first presented in 1985, that MO is a small, peculiar galaxy in which the star formation has been triggered by the radio jet. Key new results are the discovery of a double H I cloud with a mass of 4.9 x 10{sup 8} M{sub {circle_dot}} straddling the radio jet downstream from MO at the location where the jet changes direction and decollimates; a strong detection of MO at near- and far-UV wavelengths and in H{alpha}, both of which also show a double structure; and what appear to be numerous H II regions and associated clusters in MO. The UV morphology of MO along the radio jet resembles the radio-aligned, rest-frame UV morphologies seen in many high redshift radio galaxies, which are also thought to be caused by jet-induced star formation. The UV, optical, and near-IR data show that the stellar population is dominated by a 7.5Myr-old instantaneous burst, with a total stellar mass of 1.9 x 10{sup 7} M{sub {circle_dot}}.

Croft, S; van Breugel, W; de Vries, W; Dopita, M; Martin, C; Morganti, R; Neff, S; Oosterloo, T; Schiminovich, D; Stanford, S A; van Gorkom, J

2006-02-07T23:59:59.000Z

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


401

Ultraviolet and optical spectroscopy of the R Aquarii symmetrical jet  

Science Conference Proceedings (OSTI)

The first ultraviolet spectrum of the southwest (SW) component of the symmetrical jet in the R Aquarii binary system has been obtained in the range 1200-2000 A with the IUE. These results are compared to more encompassing spectra of the central H II region taken at the same time and also similar spectra of the northeast (NE) jet component obtained six months earlier. Moreover, optical spectra of both the NE and SW jet components in the range 3400-9800 A were obtained within about 6 months and about 1 month, respectively, of the ultraviolet spectra. These highly complementary observations argue that excitation of the symmetrical jet may be due to shock excitation as the jet components overtake and impact the previously ionized material associated with the expanding inner nebulosity. The problems with this shock model as well as problems with competing photoionization models are discussed. It is suggested that the jet components were ejected less than 90 years ago. 28 refs.

Hollis, J.M.; Oliversen, R.J.; Michalitsianos, A.G.; Kafatos, M.; Wagner, R.M. (NASA, Goddard Space Flight Center, Greenbelt, MD (United States) George Mason Univ., Fairfax, VA (United States) Lowell Observatory, Flagstaff, AZ (United States))

1991-08-01T23:59:59.000Z

402

Jet plume injection and combustion system for internal combustion engines  

DOE Patents (OSTI)

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.

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

1993-01-01T23:59:59.000Z

403

Production of jet fuel from coal-derived liquids  

Science Conference Proceedings (OSTI)

Amoco and Lummus Crest, under a contract with the United States Department of Energy, are evaluating the process options and economics for upgrading the naphtha, crude phenols, and tar oil by-products from the Great Plains Coal Gasification Plant to jet fuels and other salable products. Task 1 of the work, in which processes to produce each of the three jet fuels, JP-4, JP-8, and JP-8X, were designed, has been completed. The formal Task 1 report should issue next quarter. Task 2 work was initiated this quarter. In Task 2, process conditions for producing jet fuel from the Great Plains tar oil stream will be verified and samples of each of the three jet fuels will be produced. Experimental work shows that the hydrotreating conditions specified in Task 1 will not convert sufficient aromatics in the tar oil to produce jet fuel. Alternative schemes have been proposed and are being tested in the laboratories at Amoco Research Center. The simplest of these schemes, in which the heavy ends from the hydrotreater are recycled to extinction, was tested and proved infeasible. A second stage, fixed bed hydrotreater will be added to the process along with the expanded bed, first-stage hydrotreater and the hydrocracker specified in the Task 1 design. Future work will include additional experiments to specify the best process configuration and production of samples of each of the three grades of jet fuel. 6 figs., 7 tabs.

Furlong, M.W.; Fox, J.D.; Masin, J.G.; Soderberg, D.J.

1988-01-01T23:59:59.000Z

404

Jet plume injection and combustion system for internal combustion engines  

DOE Patents (OSTI)

This invention is comprised of 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.

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

1992-12-31T23:59:59.000Z

405

Jet plume injection and combustion system for internal combustion engines  

DOE Patents (OSTI)

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.

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

1993-12-21T23:59:59.000Z

406

Pulse Jet Mixing Tests With Noncohesive Solids  

SciTech Connect

This report summarizes results from pulse jet mixing (PJM) tests with noncohesive solids in Newtonian liquid conducted during FY 2007 and 2008 to support the design of mixing systems for the Hanford Waste Treatment and Immobilization Plant (WTP). Tests were conducted at three geometric scales using noncohesive simulants. The test data were used to independently develop mixing models that can be used to predict full-scale WTP vessel performance and to rate current WTP mixing system designs against two specific performance requirements. One requirement is to ensure that all solids have been disturbed during the mixing action, which is important to release gas from the solids. The second requirement is to maintain a suspended solids concentration below 20 weight percent at the pump inlet. The models predict the height to which solids will be lifted by the PJM action, and the minimum velocity needed to ensure all solids have been lifted from the floor. From the cloud height estimate we can calculate the concentration of solids at the pump inlet. The velocity needed to lift the solids is slightly more demanding than "disturbing" the solids, and is used as a surrogate for this metric. We applied the models to assess WTP mixing vessel performance with respect to the two perform¬ance requirements. Each mixing vessel was evaluated against these two criteria for two defined waste conditions. One of the wastes was defined by design limits and one was derived from Hanford waste characterization reports. The assessment predicts that three vessel types will satisfy the design criteria for all conditions evaluated. Seven vessel types will not satisfy the performance criteria used for any of the conditions evaluated. The remaining three vessel types provide varying assessments when the different particle characteristics are evaluated. The assessment predicts that three vessel types will satisfy the design criteria for all conditions evaluated. Seven vessel types will not satisfy the performance criteria used for any of the conditions evaluated. The remaining three vessel types provide varying assessments when the different particle characteristics are evaluated. The HLP-022 vessel was also evaluated using 12 m/s pulse jet velocity with 6-in. nozzles, and this design also did not satisfy the criteria for all of the conditions evaluated.

Meyer, Perry A.; Bamberger, Judith A.; Enderlin, Carl W.; Fort, James A.; Wells, Beric E.; Sundaram, S. K.; Scott, Paul A.; Minette, Michael J.; Smith, Gary L.; Burns, Carolyn A.; Greenwood, Margaret S.; Morgen, Gerald P.; Baer, Ellen BK; Snyder, Sandra F.; White, Michael; Piepel, Gregory F.; Amidan, Brett G.; Heredia-Langner, Alejandro; Bailey, Sharon A.; Bower, John C.; Denslow, Kayte M.; Eakin, David E.; Elmore, Monte R.; Gauglitz, Phillip A.; Guzman, Anthony D.; Hatchell, Brian K.; Hopkins, Derek F.; Hurley, David E.; Johnson, Michael D.; Kirihara, Leslie J.; Lawler, Bruce D.; Loveland, Jesse S.; Mullen, O Dennis; Pekour, Mikhail S.; Peters, Timothy J.; Robinson, Peter J.; Russcher, Michael S.; Sande, Susan; Santoso, Christian; Shoemaker, Steven V.; Silva, Steve M.; Smith, Devin E.; Su, Yin-Fong; Toth, James J.; Wiberg, John D.; Yu, Xiao-Ying; Zuljevic, Nino

2009-05-11T23:59:59.000Z

407

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

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

Geek-Up[6.24.11]: The End of Our Solar System is Bubbly Geek-Up[6.24.11]: The End of Our Solar System is Bubbly Geek-Up[6.24.11]: The End of Our Solar System is Bubbly June 24, 2011 - 6:15pm Addthis Old and new views of the heliosheath. Red and blue spirals are the gracefully curving magnetic field lines of orthodox models. New data from Voyager add a magnetic froth (inset) to the mix. | Courtesy of NASA Old and new views of the heliosheath. Red and blue spirals are the gracefully curving magnetic field lines of orthodox models. New data from Voyager add a magnetic froth (inset) to the mix. | Courtesy of NASA Niketa Kumar Niketa Kumar Public Affairs Specialist, Office of Public Affairs What are the key facts? Nasa's Voyager probes found a turbulent froth of magnetic bubbles, each about 100 million miles wide.

408

Electron self-injection into an evolving plasma bubble: Quasi-monoenergetic laser-plasma acceleration in the blowout regime  

Science Conference Proceedings (OSTI)

An electron density bubble driven in a rarefied uniform plasma by a slowly evolving laser pulse goes through periods of adiabatically slow expansions and contractions. Bubble expansion causes robust self-injection of initially quiescent plasma electrons, whereas stabilization and contraction terminate self-injection thus limiting injected charge; concomitant phase space rotation reduces the bunch energy spread. In regimes relevant to experiments with hundred terawatt- to petawatt-class lasers, bubble dynamics and, hence, the self-injection process are governed primarily by the driver evolution. Collective transverse fields of the trapped electron bunch reduce the accelerating gradient and slow down phase space rotation. Bubble expansion followed by stabilization and contraction suppresses the low-energy background and creates a collimated quasi-monoenergetic electron bunch long before dephasing. Nonlinear evolution of the laser pulse (spot size oscillations, self-compression, and front steepening) can also cause continuous self-injection, resulting in a large dark current, degrading the electron beam quality.

Kalmykov, S. Y.; Shadwick, B. A.; Umstadter, D. P. [Department of Physics and Astronomy, University of Nebraska - Lincoln, Lincoln, Nebraska 68588-0299 (United States); Beck, A.; Lefebvre, E. [CEA, DAM, DIF, Arpajon F-91297 (France); Yi, S. A.; Khudik, V. N.; Downer, M. C. [Department of Physics, C1500, niversity of Texas at Austin, Austin, Texas 78712 (United States)

2011-05-15T23:59:59.000Z

409

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

E-Print Network (OSTI)

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 ...

Phillips, B.

410

Visualization of gas–liquid mass transfer and wake structure of rising bubbles using pH-sensitive PLIF  

E-Print Network (OSTI)

A planar laser-induced fluorescence (PLIF) technique for visualizing gas–liquid mass transfer and wake structure of rising gas bubbles is described. The method uses an aqueous solution of the pH-sensitive dye Naphthofluorescein ...

Stohr, M.

411

Changes in Gas Bubble Disease Signs for Migrating Juvenile Salmonids Experimentally Exposed to Supersaturated Gasses, 1996-1997 Progress Report.  

DOE Green Energy (OSTI)

This study was designed to answer the question of whether gas bubble disease (GBD) signs change as a result of the hydrostatic conditions juvenile salmonids encounter when they enter the turbine intake of hydroelectric projects during their downstream migration.

Absolon, Randall F.

1999-03-01T23:59:59.000Z

412

TRIGGERED STAR FORMATION AROUND MID-INFRARED BUBBLES IN THE G8.14+0.23 H II REGION  

SciTech Connect

Mid-infrared shells or bubbles around expanding H II regions have received much attention due to their ability to initiate a new generation of star formation. We present multi-wavelength observations around two bubbles associated with a southern massive star-forming region G8.14+0.23, to investigate the triggered star formation signature on the edges of the bubbles by the expansion of the H II region. We have found observational signatures of the collected molecular and cold dust material along the bubbles and the {sup 12}CO(J = 3-2) velocity map reveals that the molecular gas in the bubbles is physically associated around the G8.14+0.23 region. We have detected 244 young stellar objects (YSOs) in the region and about 37% of these YSOs occur in clusters. Interestingly, these YSO clusters are associated with the collected material on the edges of the bubbles. We have found good agreement between the dynamical age of the H II region and the kinematical timescale of bubbles (from the {sup 12}CO(J = 3-2) line data) with the fragmentation time of the accumulated molecular materials to explain possible 'collect and collapse' process around the G8.14+0.23 region. However, one cannot entirely rule out the possibility of triggered star formation by compression of the pre-existing dense clumps by the shock wave. We have also found two massive embedded YSOs (about 10 and 22 M{sub Sun }) which are associated with the dense fragmented clump at the interface of the bubbles. We conclude that the expansion of the H II region is also leading to the formation of these two young massive embedded YSOs in the G8.14+0.23 region.

Dewangan, L. K.; Ojha, D. K.; Chakraborti, S. [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005 (India); Anandarao, B. G. [Physical Research Laboratory, Navrangpura, Ahmedabad 380 009 (India); Ghosh, S. K., E-mail: lokeshd@tifr.res.in [National Centre for Radio Astrophysics, Ganeshkhind, Pune 411 007 (India)

2012-09-10T23:59:59.000Z

413

A bubble-powered micro-rotor: conception, manufacturing, assembly, and characterization  

E-Print Network (OSTI)

A steady fluid flow, called microstreaming, can be generated in the vicinity of a micro-bubble excited by ultrasound. In this article, we use this phenomenon to assemble and power a microfabricated rotor at rotation speeds as high as 625 rpm. The extractible power is estimated to be on the order of a few femtowatts. A first series of experiments with uncontrolled rotor shapes is presented, demonstrating the possibility of this novel actuation scheme. A second series of experiments with 65 micron rotors micromanufactured in SU-8 resin are presented. Variables controlling the rotation speed and rotor stability are investigated, such as the bubble diameter, the acoustic excitation frequency and amplitude, and the rotor geometry. Finally, an outlook is provided on developing this micro-rotor into a MEMS-based motor capable of delivering tunable, infinitesimal rotary power at the microscale.

Kao, Jonathan; Warren, John; Xu, Jie; Attinger, Daniel; 10.1088/0960-1317/17/12/010

2009-01-01T23:59:59.000Z

414

Interfacial structures of confined air-water two-phase bubbly flow  

SciTech Connect

The interfacial structure of the two-phase flows is of great importance in view of theoretical modeling and practical applications. In the present study, the focus is made on obtaining detailed local two-phase parameters in the air-water bubbly flow in a rectangular vertical duct using the double-sensor conductivity probe. The characteristic wall-peak is observed in the profiles of the interracial area concentration and the void fraction. The development of the interfacial area concentration along the axial direction of the flow is studied in view of the interfacial area transport and bubble interactions. The experimental data is compared with the drift flux model with C{sub 0} = 1.35.

Kim, S.; Ishii, M.; Wu, Q.; McCreary, D.; Beus, S.G.

2000-08-01T23:59:59.000Z

415

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

Science Conference Proceedings (OSTI)

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.

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

1992-11-01T23:59:59.000Z

416

A Mechanism for Coronal Hole Jets  

E-Print Network (OSTI)

Bald patches are magnetic topologies in which the magnetic field is concave up over part of a photospheric polarity inversion line. A bald patch topology is believed to be the essential ingredient for filament channels and is often found in extrapolations of the observed photospheric field. Using an analytic source-surface model to calculate the magnetic topology of a small bipolar region embedded in a global magnetic dipole field, we demonstrate that although common in closed-field regions close to the solar equator, bald patches are unlikely to occur in the open-field topology of a coronal hole. Our results give rise to the following question: What happens to a bald patch topology when the surrounding field lines open up? This would be the case when a bald patch moves into a coronal hole, or when a coronal hole forms in an area that encompasses a bald patch. Our magnetostatic models show that, in this case, the bald patch topology almost invariably transforms into a null point topology with a spine and a fan. We argue that the time-dependent evolution of this scenario will be very dynamic since the change from a bald patch to null point topology cannot occur via a simple ideal evolution in the corona. We discuss the implications of these findings for recent Hinode XRT observations of coronal hole jets and give an outline of planned time-dependent 3D MHD simulations to fully assess this scenario.

D. A. N. Mueller; S. K. Antiochos

2008-04-24T23:59:59.000Z

417

Molecular Jet of IRAS 04166+2706  

E-Print Network (OSTI)

The molecular outflow from IRAS 04166+2706 was mapped with the Submillimeter Array (SMA) at 350 GHz continuum and CO J = 3$-$2 at an angular resolution of ~1 arcsec. The field of view covers the central arc-minute, which contains the inner four pairs of knots of the molecular jet. On the channel map, conical structures are clearly present in the low velocity range (|V$-$V$_0$|$$|V$-$V$_0$|$>$30 km $s^{-1}$). The higher angular resolution of ~1 arcsec reveals the first blue-shifted knot (B1) that was missing in previous PdBI observation of Sant\\'iago-Garc\\'a et al. (2009) at an offset of ~6 arcsec to the North-East of the central source. This identification completes the symmetric sequence of knots in both the blue- and red-shifted lobes of the outflow. The innermost knots R1 and B1 have the highest velocities within the sequence. Although the general features appear to be similar to previous CO J = 2$-$1 images in Sant\\'iago-Garc\\'a et al. (2009), the emission in CO J = 3$-$2 almost always peaks further away ...

Wang, Liang-Yao; Su, Yu-Nung; Santiago-García, Joaquín; Tafalla, Mario; Zhang, Qizhou; Hirano, Naomi; Lee, Chin-Fei

2013-01-01T23:59:59.000Z

418

Spectrometric Analysis for Pulse Jet Mixer Testing  

Science Conference Proceedings (OSTI)

The Analytical Development Section (ADS) was tasked with providing support for a Hanford River Protection Program-Waste Treatment Program (RPP-WTP) project test involving absorption analysis for non-Newtonian pulse jet mixer testing for small scale (PJM) and prototype (CRV) tanks with sparging. Tanks filled with clay were mixed with various amounts of powdered dye as a tracer. The objective of the entire project was to determine the best mixing protocol (nozzle velocity, number of spargers used, total air flow, etc.) by determining the percent mixed volume through the use of an ultraviolet-visible (UV-Vis) spectrometer. The dye concentration within the sample could be correlated to the volume fraction mixed in the tank. Samples were received in vials, a series of dilutions were generated from the clay, allowed to equilibrate, then centrifuged and siphoned for the supernate liquid to analyze by absorption spectroscopy. Equilibration of the samples and thorough mixing of the samples were a continuous issue with dilution curves being difficult to obtain. Despite these technical issues, useful data was obtained for evaluation of various mix conditions.

ZEIGLER, KRISTINE

2004-07-12T23:59:59.000Z

419

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

DOE Patents (OSTI)

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

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

1999-08-17T23:59:59.000Z

420

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

DOE Patents (OSTI)

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

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

1999-01-01T23:59:59.000Z

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


421

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

DOE Green Energy (OSTI)

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

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

1994-09-01T23:59:59.000Z

422

One-loop fluctuation-dissipation formula for bubble-wall velocity  

Science Conference Proceedings (OSTI)

The limiting bubble wall velocity during a first-order electroweak phase transition is of interest in scenarios for electroweak baryogenesis. Khlebnikov has recently proposed an interesting method for computing this velocity based on the fluctuation-dissipation theorem. It is demonstrated that at one-loop order this method is identical to simple, earlier techniques for computing the wall velocity based on computing the friction from particles reflecting off or transmitting through the wall in the ideal gas limit.

Arnold, P.

1993-06-01T23:59:59.000Z

423

Technological roots and structural implications of the double bubble at the turn of the Century  

E-Print Network (OSTI)

Époque (Europe) Progressive Era (USA) 1908 USA The Age of the Automobile, Oil and Petrochemicals Roaring twenties 1929 USA Post WWII Boom 1971 USA The Age of Information and Digital communications Second Globalisation Double bubble... , the recession, the major losses and the revelations of fraud and general misbehaviour in the financial world generate enough popular indignation and put sufficient pressure on politicians to establish strict controls. After 2000, though, the pressure...

Perez, Carlota

424

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

E-Print Network (OSTI)

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.

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

2006-08-04T23:59:59.000Z

425

Investigation into Nanostructured Lanthanum Halides and CeBr3 for Nuclear Radiation Detection  

SciTech Connect

Nanocomposites may enable the use of scintillator materials such as cerium-doped lanthanum fluoride (LaF3:Ce) and cerium bromide (CeBr3) without requiring the growth of large crystals [1]. Nanostructured detectors may allow us to engineer immensely sized detectors of flexible form factors that will have a broad energy range and an energy resolution sufficient to perform isotopic identification. Furthermore, nanocomposites are easy to prepare and very low in cost. It is much less costly to use nanocomposites rather than grow large whole crystals of scintillator materials; with nanocomposites fabricated on an industrial scale, costs are even less. Nanostructured radiation scintillator detectors may improve quantum efficiency and provide vastly improved detector form factors. Quantum efficiencies up to 60% have been seen in photoluminescence from silicon nanocrystals in a densely-packed ensemble [2]. We have fabricated nanoparticles with sizes <10 nm and characterized their nanocomposite radiation detector properties. This work investigates the properties of the nanostructured radiation scintillator in order 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 nanostructured lanthanum bromide, lanthanum fluoride, or CeBr3. Preliminary results of this investigation are consistent with a significant response of these materials to nuclear radiation.

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

2011-07-06T23:59:59.000Z

426

Does a proton "bubble" structure exist in the low-lying states of 34Si?  

E-Print Network (OSTI)

The possible existence of a "bubble" structure in the proton density of $^{34}$Si has recently attracted a lot of research interest. To examine the existence of the "bubble" structure in low-lying states, we establish a relativistic version of configuration mixing of both particle number and angular momentum projected quadrupole deformed mean-field states and apply this state-of-the-art beyond relativistic mean-field method to study the density distribution of the low-lying states in $^{34}$Si. An excellent agreement with the data of low-spin spectrum and electric multipole transition strengths is achieved without introducing any parameters. We find that the central depression in the proton density is quenched by dynamic quadrupole shape fluctuation, but not as significantly as what has been found in a beyond non-relativistic mean-field study. Our results suggest that the existence of proton "bubble" structure in the low-lying excited $0^+_2$ and $2^+_1$ states is very unlikely.

J. M. Yao; H. Mei; Z. P. Li

2013-05-21T23:59:59.000Z

427

H II REGION DRIVEN GALACTIC BUBBLES AND THEIR RELATIONSHIP TO THE GALACTIC MAGNETIC FIELD  

SciTech Connect

The relative alignments of mid-infrared traced Galactic bubbles are compared to the orientation of the mean Galactic magnetic field in the disk. The orientations of bubbles in the northern Galactic plane were measured and are consistent with random orientations-no preferential alignment with respect to the Galactic disk was found. A subsample of H II region driven Galactic bubbles was identified, and as a single population they show random orientations. When this subsample was further divided into subthermal and suprathermal H II regions, based on hydrogen radio recombination linewidths, the subthermal H II regions showed a marginal deviation from random orientations, but the suprathermal H II regions showed significant alignment with the Galactic plane. The mean orientation of the Galactic disk magnetic field was characterized using new near-infrared starlight polarimetry and the suprathermal H II regions were found to preferentially align with the disk magnetic field. If suprathermal linewidths are associated with younger H II regions, then the evolution of young H II regions is significantly affected by the Galactic magnetic field. As H II regions age, they cease to be strongly linked to the Galactic magnetic field, as surrounding density variations come to dominate their morphological evolution. From the new observations, the ratios of magnetic-to-ram pressures in the expanding ionization fronts were estimated for younger H II regions.

Pavel, Michael D.; Clemens, D. P., E-mail: pavelmi@bu.edu, E-mail: clemens@bu.edu [Institute for Astrophysical Research, Boston University, 725 Commonwealth Ave., Boston, MA 02215 (United States)

2012-12-01T23:59:59.000Z

428

Methods for Investigating Gas Bubble Formation in Uranium-Zirconium Alloys  

E-Print Network (OSTI)

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

Mews, Kathryn Ann Wright

2013-05-01T23:59:59.000Z

429

Pulse Jet Mixing Tests With Noncohesive Solids  

SciTech Connect

This report summarizes results from pulse jet mixing (PJM) tests with noncohesive solids in Newtonian liquid. The tests were conducted during FY 2007 and 2008 to support the design of mixing systems for the Hanford Waste Treatment and Immobilization Plant (WTP). Tests were conducted at three geometric scales using noncohesive simulants, and the test data were used to develop models predicting two measures of mixing performance for full-scale WTP vessels. The models predict the cloud height (the height to which solids will be lifted by the PJM action) and the critical suspension velocity (the minimum velocity needed to ensure all solids are suspended off the floor, though not fully mixed). From the cloud height, the concentration of solids at the pump inlet can be estimated. The predicted critical suspension velocity for lifting all solids is not precisely the same as the mixing requirement for 'disturbing' a sufficient volume of solids, but the values will be similar and closely related. These predictive models were successfully benchmarked against larger scale tests and compared well with results from computational fluid dynamics simulations. The application of the models to assess mixing in WTP vessels is illustrated in examples for 13 distinct designs and selected operational conditions. The values selected for these examples are not final; thus, the estimates of performance should not be interpreted as final conclusions of design adequacy or inadequacy. However, this work does reveal that several vessels may require adjustments to design, operating features, or waste feed properties to ensure confidence in operation. The models described in this report will prove to be valuable engineering tools to evaluate options as designs are finalized for the WTP. Revision 1 refines data sets used for model development and summarizes models developed since the completion of Revision 0.

Meyer, Perry A.; Bamberger, Judith A.; Enderlin, Carl W.; Fort, James A.; Wells, Beric E.; Sundaram, S. K.; Scott, Paul A.; Minette, Michael J.; Smith, Gary L.; Burns, Carolyn A.; Greenwood, Margaret S.; Morgen, Gerald P.; Baer, Ellen BK; Snyder, Sandra F.; White, Michael K.; Piepel, Gregory F.; Amidan, Brett G.; Heredia-Langner, Alejandro

2012-02-17T23:59:59.000Z

430

Sooting characteristics of surrogates for jet fuels  

Science Conference Proceedings (OSTI)

Currently, modeling the combustion of aviation fuels, such as JP-8 and JetA, is not feasible due to the complexity and compositional variation of these practical fuels. Surrogate fuel mixtures, composed of a few pure hydrocarbon compounds, are a key step toward modeling the combustion of practical aviation fuels. For the surrogate to simulate the practical fuel, the composition must be designed to reproduce certain pre-designated chemical parameters such as sooting tendency, H/C ratio, autoignition, as well as physical parameters such as boiling range and density. In this study, we focused only on the sooting characteristics based on the Threshold Soot Index (TSI). New measurements of TSI values derived from the smoke point along with other sooting tendency data from the literature have been combined to develop a set of recommended TSI values for pure compounds used to make surrogate mixtures. When formulating the surrogate fuel mixtures, the TSI values of the components are used to predict the TSI of the mixture. To verify the empirical mixture rule for TSI, the TSI values of several binary mixtures of candidate surrogate components were measured. Binary mixtures were also used to derive a TSI for iso-cetane, which had not previously been measured, and to verify the TSI for 1-methylnaphthalene, which had a low smoke point and large relative uncertainty as a pure compound. Lastly, surrogate mixtures containing three components were tested to see how well the measured TSI values matched the predicted values, and to demonstrate that a target value for TSI can be maintained using various components, while also holding the H/C ratio constant. (author)

Mensch, Amy; Santoro, Robert J.; Litzinger, Thomas A. [Department of Mechanical and Nuclear Engineering, and The Propulsion Engineering Research Center, The Pennsylvania State University, University Park, PA 16802 (United States); Lee, S.-Y. [Department of Mechanical Engineering and Engineering Mechanics, Michigan Technological University, Houghton, MI 49931 (United States)

2010-06-15T23:59:59.000Z

431

Numerical Study on GRB-Jet Formation in Collapsars  

SciTech Connect

Two-dimensional magnetohydrodynamic simulations are performed using the ZEUS-2D code to investigate the dynamics of a collapsar that generates a GRB jet, taking account of realistic equation of state, neutrino cooling and heating processes, magnetic fields, and gravitational force from the central black hole and self gravity. It is found that neutrino heating processes are not so efficient to launch a jet in this study. It is also found that a jet is launched mainly by B{sub {phi}} fields that are amplified by the winding-up effect. However, since the ratio of total energy relative to the rest mass energy in the jet is not so high as several hundred, we conclude that the jets seen in this study are not be a GRB jet. This result suggests that general relativistic effects, which are not included in this study, will be important to generate a GRB jet. Also, the accretion disk with magnetic fields may still play an important role to launch a GRB jet, although a simulation for much longer physical time {approx} 10-100 s is required to confirm this effect. It is shown that considerable amount of {sup 56}Ni is synthesized in the accretion disk. Thus there will be a possibility for the accretion disk to supply sufficient amount of {sup 56}Ni required to explain the luminosity of a hypernova. Also, it is shown that neutron-rich matter due to electron captures with high entropy per baryon is ejected along the polar axis. Moreover, it is found that the electron fraction becomes larger than 0.5 around the polar axis near the black hole by {nu}{sub e} capture at the region. Thus there will be a possibility that r-process and r/p-process nucleosynthesis occur at these regions. Finally, much neutrons will be ejected from the jet, which suggests that signals from the neutron decays may be observed as the delayed bump of the light curve of the afterglow or gamma-rays.

Nagataki, Shigehiro; /Kyoto U., Yukawa Inst., Kyoto /KIPAC, Menlo Park; Takahashi, Rohta; /Tokyo U.; Mizuta, Akira; /Garching, Max Planck Inst.; Takiwaki, Tomoya; /Tokyo U.

2006-08-22T23:59:59.000Z

432

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

SciTech Connect

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.

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

2011-03-01T23:59:59.000Z

433

Formation and destruction of jets in X-ray binaries  

E-Print Network (OSTI)

Neutron-star and black-hole X-ray binaries (XRBs) exhibit radio jets, whose properties depend on the X-ray spectral state and history of the source. In particular, black-hole XRBs emit compact, steady radio jets when they are in the so-called hard state, the jets become eruptive as the sources move toward the soft state, disappear in the soft state, and re-appear when the sources return to the hard state. On the other hand, jets from neutron-star X-ray binaries are typically weaker radio emitters than the black-hole ones at the same X-ray luminosity and in some cases radio emission is detected in the soft state. Significant phenomenology has been accumulated so far regarding the spectral states of neutron-star and black-hole XRBs, and there is general agreement about the type of the accretion disk around the compact object in the various spectral states. Our aim is to investigate whether the phenomenology regarding the X-ray emission on one hand and the jet appearance and disappearance on the other can be put...

Kylafis, N D; Kazanas, D; Christodoulou, D M

2011-01-01T23:59:59.000Z

434

Aspects of jet quenching as a diffractive phenomenon  

E-Print Network (OSTI)

We argue that the collisional aspects of jet quenching in a high energy nuclear collision are perhaps best understood as a diffractive phenomenon. The jet has a large energy, and acquires momentum transverse to its axis more effectively by multiple soft collisions than by few hard scatterings (as known from analogous systems such as $J/\\psi$ production at Hera). Such regime of large E and small momentum transfer is characteristically dominated by the pomeron. From this insight we estimate the jet quenching parameter in the hadron medium (largely a pion gas) at the end of the collision, which is naturally small and increases with temperature in line with the gas density. The treatment of diffraction in the quark-gluon plasma/liquid phase is beset with uncertainties, but we provide a couple of preliminary guesses that suggest indeed that the pomeron-mediated interactions are very relevant and provide a further handle on the jet quenching parameter, that perturbation theory seems to underestimate. Finally, the ocasional hard collisions produce features characteristic of a L\\'evy flight in the ${\\bf q}_\\perp^2$ plane perpendicular to the jet axis. We suggest one- and two-particle ${\\bf q}_\\perp$ correlations as interesting experimental probes.

Carlos Hidalgo-Duque; Felipe J. Llanes-Estrada

2013-09-27T23:59:59.000Z

435

Production of jet fuel from coal-derived liquids  

Science Conference Proceedings (OSTI)

Amoco and Lummus Crest, under a contract with the United States Department of Energy, are evaluating the process options and economics for upgrading the naphtha, crude phenols, and tar oil by-products from the Great Plains Coal Gasification Plant to jet fuels and other salable products. Conceptual processing schemes for maximizing the production of Grades JP-4, JP-8, and high-density (JP-8X) jet fuels, for maximizing profits, and for profitable production of each of the three jet fuels from the by-product liquids have been developed. Economic analyses of the designs show that jet fuel can be produced from the by-products, but not economically. However, jet fuel production could be subsidized profitably by processing the phenolic and naphtha streams to cresols, phenols, BTX, and other valuable chemical by-products. Uncertainties in the studies are marketability of the chemical by-products, replacement fuel costs, and viable schemes to process the phenol stream, among others. 8 figs., 2 tabs.

Furlong, M.W.; Fox, J.D.; Masin, J.G.; Soderberg, D.J.

1990-01-01T23:59:59.000Z

436

Aspects of jet quenching as a diffractive phenomenon  

E-Print Network (OSTI)

We argue that the collisional aspects of jet quenching in a high energy nuclear collision are perhaps best understood as a diffractive phenomenon. The jet has a large energy, and acquires momentum transverse to its axis more effectively by multiple soft collisions than by few hard scatterings (as known from analogous systems such as J/psi production at Hera). Such regime of large E and small momentum transfer is characteristically dominated by the pomeron. From this insight we estimate the jet quenching parameter in the hadron medium (largely a pion gas) at the end of the collision, which is naturally small and increases with temperature in line with the gas density. The treatment of diffraction in the quark-gluon plasma/liquid phase is beset with uncertainties, but we provide a couple of preliminary guesses that suggest indeed that the pomeron-mediated interactions are very relevant and provide a further handle on the jet quenching parameter, that perturbation theory seems to underestimate. Finally, the ocasional hard collisions produce features characteristic of a L\\`evy flight in the q_perp^2 plane perpendicular to the jet axis. We suggest one- and two-particle q_perp correlations as interesting experimental probes.

Carlos Hidalgo-Duque; Felipe J. Llanes-Estrada

2013-09-27T23:59:59.000Z

437

Implementation And Performance of the ATLAS Second Level Jet Trigger  

SciTech Connect

ATLAS is one of the four major LHC experiments, designed to cover a wide range of physics topics. In order to cope with a rate of 40MHz and 25 interactions per bunch crossing, the ATLAS trigger system is divided in three different levels. The jet selection starts at first level with dedicated processors that search for high E{sub T} hadronic energy depositions. At the LVL2, the jet signatures are verified with the execution of a dedicated, fast jet reconstruction algorithm, followed by a calibration algorithm. Three possible granularities have been proposed and are being evaluated: cell based (standard), energy sums calculated at each Front-End Board and the use of the LVL1 Trigger Towers. In this presentation, the design and implementation of the jet trigger of ATLAS will be discussed in detail, emphasazing the major difficulties of each selection step. The performance of the jet algorithm, including timing, efficiencies and rates will also be shown, with detailed comparisons of the different unpacking modes.

Conde Muino, Patricia; /Lisbon, LIFEP; Aracena, I.; /SLAC; Brelier, B.; /Montreal U.; Cranmer, K.; /Brookhaven; Delsart, P.A.; /Montreal U.; Dufour, M.A.; /McGill U.; Eckweiler, S.; /Mainz U., Inst. Phys.; Ferland, J.; /Montreal U.; Idarraga, J.; /Montreal U.; Johns, K.; /Arizona U.; LeCompte, T.; /Argonne; Potter, C.; Robertson, S.; Santamarina Rios, C.; /McGill U.; Segura, E.; /Barcelona, IFAE; Silverstein, D.; /SLAC; Vachon, B.; /McGill U.

2011-11-09T23:59:59.000Z

438

Commissioning of the ITER-like ICRF antenna for JET  

Science Conference Proceedings (OSTI)

The new JET ion cyclotron resonance frequency (ICRF) ITER-like antenna (ILA), which was assembled during 2006, was commissioned on the JET RF testbed prior to installation on the JET torus. The 4 resonant double loops (RDL) of the ILA were tested at high power at 42 MHz up to 42 kV for 5 s in 10 min intervals. Low power matching studies using a saltwater load placed in front of the ILA have allowed testing and optimizing proposed matching algorithms on single RDLs, paired RDLs and finally on the full array. The upper limit of the frequency range of the ILA appears to be limited to 47 49 MHz due to the effect on the electrical lengths of the connection between the capacitors and the conjugate T point. Capacitor position scans have allowed obtaining the necessary data to confirm the RF model of the RDL which is necessary for the scattering matrix arc detection. The latter is deemed necessary in order to detect arcs at the low impedance conjugate T of the circuit. The antenna was installed onto JET during August 2007 and commissioning on plasma started May 2008. At present the commissioning of the ILA on JET is ongoing in a series of dedicated experimental campaigns.

Durodie, F. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Dumortier, P. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Huygen, S. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Jachmich, S. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Lerche, E. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Messiaen, A. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Ongena, J. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Van Eester, D. [Laboratory for Plasma Physics-ERM/KMS (LPP-ERM/KMS), Brussels, Belgium; Vervier, M. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Vrancken, M. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Nightingale, M. [EURATOM / UKAEA, Abingdon, UK; Blackman, T. [EURATOM / UKAEA, Abingdon, UK; Edwards, P. [EURATOM / UKAEA, Abingdon, UK; Fanthome, J. [EURATOM / UKAEA, Abingdon, UK; Graham, M. [EURATOM / UKAEA, Abingdon, UK; Jacquet, P. [EURATOM / UKAEA, Abingdon, UK; Kaye, A. [EURATOM / UKAEA, Abingdon, UK; Mayoral, M. -L. [EURATOM / UKAEA, Abingdon, UK; Monakhov, I. [EURATOM / UKAEA, Abingdon, UK; Nicholls, K. [EURATOM / UKAEA, Abingdon, UK; Stork, D. [EURATOM / UKAEA, Abingdon, UK; Walden, A. [EURATOM / UKAEA, Abingdon, UK; Whitehurst, A. [EURATOM / UKAEA, Abingdon, UK; Zastrow, K. -D. [EURATOM / UKAEA, Abingdon, UK; Argouarch, A. [CEA-Cadarache, St. Paul lex Durance, France; Berger-By, G. [CEA-Cadarache, St. Paul lex Durance, France; Loarer, T. [CEA-Cadarache, St. Paul lex Durance, France; Rimini, F. [CEA-Cadarache, St. Paul lex Durance, France; Castano-Giraldo, C. [University of Illinois, Urbana-Champaign; Caughman, John B [ORNL; Goulding, Richard Howell [ORNL; Cocilovo, V. [Association Euratom-ENEA sulla Fusione, Italy; Frigione, D. [Association Euratom-ENEA sulla Fusione, Italy; Sozzi, C. [Association Euratom-ENEA sulla Fusione, Italy; Hobrik, J. [Max-Planck-Institut fu?r Plasmaphysik, EURATOM Association, Garching, Germany; Lamalle, Philippe [ITER Joint Work Site, Cadarache; Nave, M. F. F. [Association EURATOM/IST, Lisbon, Portugal; Tsalas, M. [Association EURATOM-Hellas, Attica, Greece

2009-06-01T23:59:59.000Z

439

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

SciTech Connect

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.

Ko, Suk M. (Huntsville, AL)

1980-01-01T23:59:59.000Z

440

Robust CsBr/Cu Photocathodes for the Linac Coherent Light Source  

Science Conference Proceedings (OSTI)

The linac coherent light source (LCLS), an x-ray free-electron laser project presently under construction at SLAC, uses a 2.856 GHz rf photocathode gun with a copper cathode for its electron source. While the copper cathode is performing well for the LCLS project, a cathode material with higher quantum efficiency would reduce the drive laser requirements and allow a greater range of operating conditions. Therefore a robust CsBr/Cu photocathode with greater than 50 times the quantum yield at 257 nm relative to the present LCLS copper cathode has been investigated. Preliminary experiments using a dedicated electron source development test stand at SLAC/SSRL are encouraging and are presented in this paper.

Maldonado, Juan R.; /Stanford U., Phys. Dept.; Liu, Zhi; Dowell, D.H.; Kirby, Robert E.; Sun, Yun; Pianetta, Piero; /SLAC; Pease, Fabian; /Stanford U., Phys. Dept.

2011-06-21T23:59:59.000Z

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


441

Comparison of LaBr3:Ce and NaI(Tl) Scintillators for Radio-Isotope Identification Devices  

SciTech Connect

Lanthanum halide (LaBr3:Ce) scintillators offer significantly better resolution (<3 percent at 662 kilo-electron volt [keV]) relative to sodium iodide (NaI(Tl)) and have recently become commercially available in sizes large enough for the hand-held radio-isotope identification device (RIID) market. There are drawbacks to lanthanum halide detectors, however. These include internal radioactivity that contributes to spectral counts and a low-energy response that can cause detector resolution to be lower than that of NaI(Tl) below 100 keV. To study the potential of this new material for RIIDs, we performed a series of measurements comparing a 1.5?1.5 inch LaBr?3:Ce detector with an Exploranium GR 135 RIID, which contains a 1.5-2.2 inch NaI(Tl) detector. Measurements were taken for short time frames, as typifies RIID usage. Measurements included examples of naturally occurring radioactive material (NORM), typically found in cargo, and special nuclear materials. Some measurements were noncontact, involving short distances or cargo shielding scenarios. To facilitate direct comparison, spectra from the different detectors were analyzed with the same isotope identification software (ORTEC ScintiVision TM). In general, the LaBr3:Ce detector was able to find more peaks and find them faster than the NaI(Tl) detector. To the same level of significance, the LaBr3:Ce detector was usually two to three times faster. The notable exception was for 40K containing NORM where interfering internal contamination in the LaBr3:Ce detector exist. NaI(Tl) consistently outperformed LaBr3:Ce for this important isotope. LaBr3:Ce currently costs much more than NaI(Tl), though this cost-difference is expected to diminish (but not completely) with time. As is true of all detectors, LaBr3:Ce will need to be gain-stabilized for RIID applications. This could possibly be done using the internal contaminants themselves. It is the experience of the authors that peak finding software in RIIDs needs to be improved, regardless of the detector material.

Milbrath, Brian D.; Choate, Bethany J.; Fast, Jim E.; Hensley, Walter K.; Kouzes, Richard T.; Schweppe, John E.

2006-07-31T23:59:59.000Z

442

Effects of geometry on slot-jet film cooling performance  

DOE Green Energy (OSTI)

Physics of film cooling for shaped, inclined slot-jets with realistic slot-length-to-width ratios is studied for a range of blowing ratio and density ratio parameters typical of gas turbine operations. Effect of inlet and exit shaping of the slot-jet on both flow and thermal field is isolated, and the dominant mechanisms responsible for differences in these items are documented. A computation method was used to study 4 configurations. Field results and surface phenomena are presented. Both adiabatic film effectiveness and heat transfer coefficient are vital in assessing film cooling performance. Performance of two popular turbulence models were studied to evaluate ability to handle highly elliptic jet/crossflow interaction type processes. The simulations were consistent.

Hyams, D.G.; McGovern, K.T.; Leyiek, J.H. [Clemson Univ., SC (United States). Dept. of Mechanical Engineering

1995-12-31T23:59:59.000Z

443

Production of jet fuels from coal derived liquids  

SciTech Connect

Amoco and Lummus Crest have developed seven cases for upgrading by-product liquids from the Great Plains Coal Gasification Plant to jet fuels, and in several of the cases, saleable chemicals in addition to jet fuels. The analysis shows that the various grades of jet fuel can be produced from the Great Plains tar oil, but not economically. However, the phenolic and naphtha streams do have the potential to significantly increase (on the order of $10--15 million/year) the net revenues at Great Plains by producing chemicals, especially cresylic acid, cresol, and xylenol. The amount of these chemicals, which can be marketed, is a concern, but profits can be generated even when oxygenated chemical sales are limited to 10 percent of the US market. Another concern is that while commercial processes exist to extract phenolic mixtures, these processes have not been demonstrated with the Great Plains phenolic stream. 9 refs., 24 figs., 14 tabs.

Fleming, B.A.; Fox, J.D.; Furlong, M.W.; Masin, J.G.; Sault, L.P.; Tatterson, D.F. (Amoco Oil Co., Naperville, IL (USA). Research and Development Dept.); Fornoff, L.L.; Link, M.A.; Stahlnecker, E.; Torster, K. (Lummus Crest, Inc., Bloomfield, NJ (USA))

1988-09-01T23:59:59.000Z

444

An Independent Derivation of the Oxford Jet Kinetic Luminosity Formula  

E-Print Network (OSTI)

This letter presents a theoretical derivation of an estimate for a radio source jet kinetic luminosity. The expression yields jet powers that are quantitatively similar to a more sophisticated empirical relation published by the Willott, Blundell and Rawlings at Oxford. The formula allows one to estimate the jet kinetic luminosity from the measurement of the optically thin radio lobe emission in quasars and radio galaxies. Motivated by recent X-ray observation, the derivation assumes that most of the energy in the lobes is in plasma thermal energy with a negligible contribution from magnetic energy (not equipartition). The close agreement of the two independent expressions makes the veracity of these estimates seem very plausible.

Brian Punsly

2005-03-11T23:59:59.000Z

445

Integrated coke, asphalt and jet fuel production process and apparatus  

DOE Patents (OSTI)

A process and apparatus for the production of coke, asphalt and jet fuel m a feed of fossil fuels containing volatile carbon compounds therein is disclosed. The process includes the steps of pyrolyzing the feed in an entrained bed pyrolyzing means, separating the volatile pyrolysis products from the solid pyrolysis products removing at least one coke from the solid pyrolysis products, fractionating the volatile pyrolysis products to produce an overhead stream and a bottom stream which is useful as asphalt for road pavement, condensing the overhead stream to produce a condensed liquid fraction and a noncondensable, gaseous fraction, and removing water from the condensed liquid fraction to produce a jet fuel-containing product. The disclosed apparatus is useful for practicing the foregoing process. the process provides a useful method of mass producing and jet fuels from materials such as coal, oil shale and tar sands.

Shang, Jer Y. (McLean, VA)

1991-01-01T23:59:59.000Z

446

Physical properties of blazar jets from VLBI observations  

E-Print Network (OSTI)

(abridged) Relativistic jets, formed in the vicinity of central supermassive black holes in AGN, show ample evidence connecting them to physical conditions in the accretion disc and broad-line region. The jets are responsible for a large fraction of non-thermal continuum emission (particularly during powerful flares), which makes understanding their physics an important aspect of studies of blazars characterised by profound flaring activity arising from extremely compact regions. Imaging and polarimetry of radio emission on milliarcsecond scales provided by very long baseline interferometry (VLBI) offers a range of possibilities for studying ultra-compact regions in relativistic jets and relating them to main manifestations of the blazar activity in AGN. Simultaneous monitoring of optical/high energy variability and evolution of parsec-scale radio structures yields arguably the most detailed picture of the relation between acceleration and propagation of relativistic flows and non-thermal continuum generation...

Lobanov, Andrei

2010-01-01T23:59:59.000Z

447

The Design and Performance of the ATLAS jet trigger  

E-Print Network (OSTI)

The ATLAS jet trigger, in combination with other triggers, provides an important ingredient to studies of Standard Model physics and searches for new physics at the LHC. The ATLAS jet trigger system has undergone substantial modifications over the past few years of LHC operations, as experience developed with triggering in a high luminosity and high event pileup environment. In particular, the region-of-interest (ROI) based strategy has been replaced by a full scan of the calorimeter data at the third trigger level, and by a full scan of the level-1 trigger input at level-2 for some specific trigger chains. Hadronic calibration and cleaning techniques are applied in order to provide improved performance and increased stability in high luminosity data taking conditions. In this presentation we describe the structure and performance of the jet trigger in recent data taking conditions.

Rubbo, F; The ATLAS collaboration

2013-01-01T23:59:59.000Z

448

Heavy Rain in the Middle East Related to Unusual Jet Stream Properties  

Science Conference Proceedings (OSTI)

A major and fatal flooding event illustrative of rare similar cases in the Middle East was related to unusual characteristics of the jet stream. Contrary to the usual conditions, the jet stream had anticyclonic curvature and sloped northward with ...

Uri Dayan; Richard Abramski

1983-10-01T23:59:59.000Z

449

On the Mechanism Underlying the Spontaneous Emergence of Barotropic Zonal Jets  

Science Conference Proceedings (OSTI)

Zonal jets are commonly observed to spontaneously emerge in a ?-plane channel from a background of turbulence that is sustained in a statistical steady state by homogeneous stochastic excitation and dissipation of vorticity. The mechanism for jet ...

Nikolaos A. Bakas; Petros J. Ioannou

2013-07-01T23:59:59.000Z

450

Gas jet disruption mitigation studies on Alcator C-Mod and DIII-D  

E-Print Network (OSTI)

High-pressure noble gas jet injection is a mitigation technique which potentially satisfies the requirements of fast response time and reliability, without degrading subsequent discharges. Previously reported gas jet ...

Hollmann, E. M.

451

Active noise control in supersonic impinging jets using pulsed microjets : actuator design, reduced-order modeling  

E-Print Network (OSTI)

In recent years, it has been demonstrated that direct microjet injection into the shear layer of the main jet disrupts the feedback loop inherent in high speed impinging jet flows, thereby significantly reduces the adverse ...

Choi, Jae Jeen, 1975-

2006-01-01T23:59:59.000Z

452

Climatology of Storm Reports Relative to Upper-Level Jet Streaks  

Science Conference Proceedings (OSTI)

Using quasigeostrophic arguments and numerical simulations, past works have developed conceptual models of vertical circulations induced by linear and curved jet streaks. Because jet-induced vertical motion could influence the development of ...

Adam J. Clark; Christopher J. Schaffer; William A. Gallus Jr.; Kaj Johnson-O’Mara

2009-08-01T23:59:59.000Z

453

The Hydraulics of an Evolving Upwelling Jet Flowing around a Cape  

Science Conference Proceedings (OSTI)

Upwelling jets flow alongshore in approximate geostrophic balance with the onshore pressure gradient induced by coastal upwelling. Observations of such jets have shown that they often move offshore downstream of capes, leaving a pool of upwelled ...

Andrew C. Dale; John A. Barth

2001-01-01T23:59:59.000Z

454

Asymmetry of an Equilibrated Gulf Stream–Type Jet over Topographic Slope  

Science Conference Proceedings (OSTI)

The symmetry properties of the Gulf Stream–type jet equilibrated over topographic slope are investigated in a series of idealized numerical experiments. A baroclinically unstable zonal jet equilibrates over a sloping bottom through the process of ...

Sergei A. Frolov; Georgi G. Sutyrin; Isaac Ginis

2004-05-01T23:59:59.000Z

455

Emergence of Jets from Turbulence in the Shallow-Water Equations on an Equatorial Beta Plane  

Science Conference Proceedings (OSTI)

Coherent jets, such as the Jovian banded winds, are a prominent feature of rotating turbulence. Shallow-water turbulence models capture the essential mechanism of jet formation, which is systematic eddy momentum flux directed up the mean velocity ...

Brian F. Farrell; Petros J. Ioannou

2009-10-01T23:59:59.000Z

456

Generation and Propagation of Inertia–Gravity Waves from Vortex Dipoles and Jets  

Science Conference Proceedings (OSTI)

This study investigates gravity wave generation and propagation from jets within idealized vortex dipoles using a nonhydrostatic mesoscale model. Two types of initially balanced and localized jets induced by vortex dipoles are examined here. ...

Shuguang Wang; Fuqing Zhang; Chris Snyder

2009-05-01T23:59:59.000Z

457

Equatorial Jets in Decaying Shallow-Water Turbulence on a Rotating Sphere  

Science Conference Proceedings (OSTI)

Ensemble experiments of decaying shallow-water turbulence on a rotating sphere are performed to confirm the robustness of the emergence of an equatorial jet. While previous studies have reported that the equatorial jets emerging in shallow-water ...

Yuji Kitamura; Keiichi Ishioka

2007-09-01T23:59:59.000Z

458

MODELING AND ANALYSIS OF CHEMILUMINESCENCE SENSING FOR SYNGAS, METHANE AND JET-A COMBUSTION  

E-Print Network (OSTI)

MODELING AND ANALYSIS OF CHEMILUMINESCENCE SENSING FOR SYNGAS, METHANE AND JET-A COMBUSTION of Technology August 2008 #12;MODELING AND ANALYSIS OF CHEMILUMINESCENCE SENSING FOR SYNGAS, METHANE AND JET

Seitzman, Jerry M.

459

QCD Corrections to Jet Correlations in Weak Boson Fusion  

E-Print Network (OSTI)

Higgs boson production via weak boson fusion is sensitive to the tensor structure of the HVV (V=W,Z) couplings, which distinguishes loop induced vertices from SM expectations. At the CERN Large Hadron Collider this information shows up most clearly in the azimuthal angle correlations of the two forward and backward quark jets which are typical for weak boson fusion. We calculate the next-to-leading order QCD corrections to this process, in the presence of anomalous HVV couplings. Gluon emission does not significantly change the azimuthal jet correlations.

Terrance Figy; Dieter Zeppenfeld

2004-03-30T23:59:59.000Z

460

Upgrade of the JET far infrared interferometer diagnostic  

Science Conference Proceedings (OSTI)

In recent years there has been a major upgrade of the JET far infrared diagnostic system consisting of a new laser system with the wavelength at 118.8 {mu}m at and more advanced processing electronics for phase counting. This provides a second colour measurement of the electron plasma density on the vertical system. Due to the shorter wavelength, the plasma induced laser beam refraction is reduced by a factor of three alleviating density errors caused by loss of signal (so-called 'fringe jumps'[A. Murari et al., Rev. Sci. Instrum. 77, 073505 (2006)]), in particular during high performance plasmas experiments in JET.

Boboc, A.; Edlington, T.; Dorling, S. [EURATOM/CCFE Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Gil, C.; Pastor, P.; Spuig, P. [CEA, IRFM, Cadarache F-13108 Saint-Paul-Lez-Durance (France); Collaboration: JET-EFDA Contributors

2012-10-15T23:59:59.000Z

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


461

Velocity Profiles in a Cylindrical Liquid Jet by Reconstructed Velocimetry  

E-Print Network (OSTI)

in such a way that the jet boundaries appeared sharply focused. The Newtonian liquid used in all the experiments was a mixture of 74.7% glycerol (99.9% pure) with 25.3% tri- distilled water (weight percentage). Its measured properties were: density ? = 1250... dynamics theory (or numerical simulations) for un-wetted nozzles, but to explore the effects of nozzle wetting on the velocity profiles. It is well-known that nozzle face wetting slightly enlarges the jet diameter for some distance down- stream from...

Castrejon-Pita, J.R.; Hoath, S.D.; Hutchings, I.M.

2012-01-01T23:59:59.000Z

462

Single-Phase Self-Oscillating Jets for Enhanced Heat Transfer: Preprint  

DOE Green Energy (OSTI)

Self-oscillating jets have potential to cool insulated gate bipolar transistors in vehicle power electronics modules.

Narumanchi, S.; Kelly, K.; Mihalic, M.; Gopalan, S.; Hester, R.; Vlahinos, A.

2008-06-01T23:59:59.000Z

463

South Carolina Kerosene-Type Jet Fuel All Sales/Deliveries by ...  

U.S. Energy Information Administration (EIA)

South Carolina Kerosene-Type Jet Fuel All Sales/Deliveries by Prime Supplier (Thousand Gallons per Day)

464

Azimuthal decorrelations and multiple parton interactions in photon+2 jet and photon+3 jet events in ppbar collisions at sqrt{s}=1.96 TeV  

SciTech Connect

Samples of inclusive {gamma} + 2 jet and {gamma} + 3 jet events collected by the D0 experiment with an integrated luminosity of about 1 fb{sup -1} in p{bar p} collisions at {radical}s = 1.96 TeV are used to measure cross sections as a function of the angle in the plane transverse to the beam direction between the transverse momentum (p{sub T}) of the {gamma} + leading jet system (jets are ordered in p{sub T}) and p{sub T} of the other jet for {gamma} + 2 jet, or p{sub T} sum of the two other jets for {gamma} + 3 jet events. The results are compared to different models of multiple parton interactions (MPI) in the pythia and sherpa Monte Carlo (MC) generators. The data indicate a contribution from events with double parton (DP) interactions and are well described by predictions provided by the pythia MPI models with p{sub T}-ordered showers and by sherpa with the default MPI model. The {gamma} + 2 jet data are also used to determine the fraction of events with DP interactions as a function of the azimuthal angle and as a function of the second jet p{sub T}.

Abazov, Victor Mukhamedovich; /Dubna, JINR; Abbott, Braden Keim; /Oklahoma 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; Ancu, Lucian Stefan; /Nijmegen U. /Serpukhov, IHEP

2011-01-01T23:59:59.000Z

465

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

SciTech Connect

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

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

2009-07-01T23:59:59.000Z

466

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

SciTech Connect

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.

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

467

Estimated Maximum Gas Retention from Uniformly Dispersed Bubbles in K Basin Sludge Stored in Large-Diameter Containers  

DOE Green Energy (OSTI)

This letter report addresses the KE Basin sludge that will be retrieved and stored in large-diameter containers (LDCs.) A fraction of the hydrogen gas bubbles generated from the corrosion of uranium metal and oxides may be retained within the sludge matrix. Those entrapped bubbles will expand the sludge bed volume and, therefore, will affect how much sludge can be loaded into a container. The entrapped gas bubbles will also impact the overall thermal conductivity and heat capacity of the sludge bed. The evaluation summarized here was performed to estimate the maximum gas holdup (volume fraction gas) that could occur sludge stored in large-diameter containers, assuming uniform gas generation (i.e., uniform distribution of metallic uranium particles). This report represents an evaluation of the retention of uniformly distributed bubbles and an estimate of the maximum gas fraction that might be retained in K Basin LDCs based on existing literature data on bubble retention and Basin sludge characterization data. Existing data show that the maximum gas fraction varies, depending on physical properties and the configuration of the material or waste.

Gauglitz, Phillip A.; Terrones, Guillermo

2002-05-15T23:59:59.000Z

468

CENTIMETER CONTINUUM OBSERVATIONS OF THE NORTHERN HEAD OF THE HH 80/81/80N JET: REVISING THE ACTUAL DIMENSIONS OF A PARSEC-SCALE JET  

SciTech Connect

We present 6 and 20 cm Jansky Very Large Array/Very Large Array observations of the northern head of the HH 80/81/80N jet, one of the largest collimated jet systems known so far, aimed to look for knots farther than HH 80N, the northern head of the jet. Aligned with the jet and 10' northeast of HH 80N, we found a radio source not reported before, with a negative spectral index similar to that of HH 80, HH 81, and HH 80N. The fit of a precessing jet model to the knots of the HH 80/81/80N jet, including the new source, shows that the position of this source is close to the jet path resulting from the modeling. If the new source belongs to the HH 80/81/80N jet, its derived size and dynamical age are 18.4 pc and >9 Multiplication-Sign 10{sup 3} yr, respectively. If the jet is symmetric, its southern lobe would expand beyond the cloud edge resulting in an asymmetric appearance of the jet. Based on the updated dynamical age, we speculate on the possibility that the HH 80/81/80N jet triggered the star formation observed in a dense core found ahead of HH 80N, which shows signposts of interaction with the jet. These results indicate that parsec-scale radio jets can play a role in the stability of dense clumps and the regulation of star formation in the molecular cloud.

Masque, Josep M.; Estalella, Robert [Departament d'Astronomia i Meteorologia, Universitat de Barcelona, Marti i Franques 1, E-08028 Barcelona, Catalunya (Spain); Girart, Josep M. [Institut de Ciencies de l'Espai, (CSIC-IEEC), Campus UAB, Facultat de Ciencies, Torre C5-parell 2, E-08193 Bellaterra, Catalunya (Spain); Rodriguez, Luis F. [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 3-72, 58090 Morelia, Michoacan (Mexico); Beltran, Maria T. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy)

2012-10-10T23:59:59.000Z