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Note: This page contains sample records for the topic "high velocity sdhv" from the National Library of EnergyBeta (NLEBeta).
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1

An insitu borescopic quantitative imaging profiler for the measurement of high concentration sediment velocity  

E-Print Network (OSTI)

of high concentration sediment velocity Edwin A. Cowen •instantaneous velocity in high sediment concentration ?ows,point reveals the sheet ?ow sediment velocities to be highly

Cowen, Edwin A.; Dudley, Russell D.; Liao, Qian; Variano, Evan A.; Liu, Philip L.-F.

2010-01-01T23:59:59.000Z

2

Experimental High Velocity Acid Jetting in Limestone Carbonates  

E-Print Network (OSTI)

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

Holland, Christopher

2014-04-30T23:59:59.000Z

3

High velocity spectroscopic binary orbits from photoelectric radial velocities: BD +30 2129 A  

E-Print Network (OSTI)

The spectroscopic orbit of a high proper motion visual binary system BD +30 2129 component A is determined from 22 CORAVEL-type radial velocity measurements. A period of P = 32.79 days and a moderate eccentricity e = 0.29 are obtained. The visual system AB has a projected spatial separation ~580 AU. The system's barycenter velocity V0 = -35.95 km/s and the transverse velocity Vt = 132.2 km/s. The Galactic spatial velocity components U = +76.7 km/s, V = 110.4 km/s, W = -26.6 km/s, and a large ultraviolet excess give evidence that the star belongs to thick disk population of the Galaxy.

A. Bartkevicius; J. Sperauskas

2007-01-30T23:59:59.000Z

4

High Velocity Spectroscopic Binary Orbits from Photoelectric Radial Velocities: BD +82 565A  

E-Print Network (OSTI)

The spectroscopic orbit of a circumpolar high-proper-motion visual binary BD +82 565 A component is determined from 57 CORAVEL radial velocity measurements. A short period P = 12.69 d and a moderate eccentricity e = 0.30 are obtained. The visual system AB has a projected spatial separation ~830 AU. The system's barycenter velocity V_0 = -86.7 km/s, the transverse velocity V_t = 118.7 km/s and the Galactic spatial velocity components U = -62.6 km/s, V = -84.1 km/s and W = -84.2 km/s give evidence that it belongs to the thick disk of the Galaxy.

A. Bartkevicius; J. Sperauskas

2006-01-10T23:59:59.000Z

5

MAGNETIZED GAS IN THE SMITH HIGH VELOCITY CLOUD  

SciTech Connect

We report the first detection of magnetic fields associated with the Smith High Velocity Cloud. We use a catalog of Faraday rotation measures toward extragalactic radio sources behind the Smith Cloud, new H I observations from the Robert C. Byrd Green Bank Telescope, and a spectroscopic map of H? from the Wisconsin H-Alpha Mapper Northern Sky Survey. There are enhancements in rotation measure (RM) of ?100 rad m{sup –2} which are generally well correlated with decelerated H? emission. We estimate a lower limit on the line-of-sight component of the field of ?8 ?G along a decelerated filament; this is a lower limit due to our assumptions about the geometry. No RM excess is evident in sightlines dominated by H I or H? at the velocity of the Smith Cloud. The smooth H? morphology of the emission at the Smith Cloud velocity suggests photoionization by the Galactic ionizing radiation field as the dominant ionization mechanism, while the filamentary morphology and high (?1 Rayleigh) H? intensity of the lower-velocity magnetized ionized gas suggests an ionization process associated with shocks due to interaction with the Galactic interstellar medium. The presence of the magnetic field may contribute to the survival of high velocity clouds like the Smith Cloud as they move from the Galactic halo to the disk. We expect these data to provide a test for magnetohydrodynamic simulations of infalling gas.

Hill, Alex S.; McClure-Griffiths, Naomi M. [CSIRO Astronomy and Space Science, Marsfield, NSW (Australia); Mao, S. A. [Department of Astronomy, University of Wisconsin-Madison, Madison, WI (United States); Benjamin, Robert A. [Department of Physics, University of Wisconsin-Whitewater, Whitewater, WI (United States); Lockman, Felix J., E-mail: alex.hill@csiro.au, E-mail: naomi.mcclure-griffiths@csiro.au, E-mail: mao@astro.wisc.edu, E-mail: benjamir@uww.edu, E-mail: jlockman@nrao.edu [National Radio Astronomy Observatory, Green Bank, WV (United States)

2013-11-01T23:59:59.000Z

6

High-Velocity Oxygen Fuel Thermal Spray of Fe-Based Amorphous Alloy: a Numerical and Experimental Study  

E-Print Network (OSTI)

High-Velocity Oxygen Fuel Thermal Spray of Fe-Basedusing a high velocity oxygen fuel (HVOF) spray processstructure. [12] High velocity oxygen fuel (HVOF) thermal

Ajdelsztajn, L.; Dannenberg, J.; Lopez, J.; Yang, N.; Farmer, J.; Lavernia, E. J.

2009-01-01T23:59:59.000Z

7

Experimental and numerical studies of high-velocity impact fragmentation  

SciTech Connect

Developments are reported in both experimental and numerical capabilities for characterizing the debris spray produced in penetration events. We have performed a series of high-velocity experiments specifically designed to examine the fragmentation of the projectile during impact. High-strength, well-characterized steel spheres (6.35 mm diameter) were launched with a two-stage light-gas gun to velocities in the range of 3 to 5 km/s. Normal impact with PMMA plates, thicknesses of 0.6 to 11 mm, applied impulsive loads of various amplitudes and durations to the steel sphere. Multiple flash radiography diagnostics and recovery techniques were used to assess size, velocity, trajectory and statistics of the impact-induced fragment debris. Damage modes to the primary target plate (plastic) and to a secondary target plate (aluminum) were also evaluated. Dynamic fragmentation theories, based on energy-balance principles, were used to evaluate local material deformation and fracture state information from CTH, a three-dimensional Eulerian solid dynamics shock wave propagation code. The local fragment characterization of the material defines a weighted fragment size distribution, and the sum of these distributions provides a composite particle size distribution for the steel sphere. The calculated axial and radial velocity changes agree well with experimental data, and the calculated fragment sizes are in qualitative agreement with the radiographic data. A secondary effort involved the experimental and computational analyses of normal and oblique copper ball impacts on steel target plates. High-resolution radiography and witness plate diagnostics provided impact motion and statistical fragment size data. CTH simulations were performed to test computational models and numerical methods.

Kipp, M.E.; Grady, D.E.; Swegle, J.W.

1993-08-01T23:59:59.000Z

8

Velocity alignment leads to high persistence in confined cells  

E-Print Network (OSTI)

Many cell types display random motility on two-dimensional substrates, but crawl persistently in a single direction when confined in a microchannel or on an adhesive micropattern. Does this imply that the motility mechanism of confined cells is fundamentally different from that of unconfined cells? We argue that both free- and confined- cell migration may be described by a generic model of cells as "velocity aligning" active Brownian particles previously proposed to solve a completely separate problem in collective cell migration. Our model can be mapped to a diffusive escape over a barrier and analytically solved to determine the cell's orientation distribution and repolarization rate. In quasi-one-dimensional confinement, velocity-aligning cells maintain their direction for times that can be exponentially larger than their persistence time in the absence of confinement. Our results suggest an important new connection between single- and collective- cell migration: high persistence in confined cells correspo...

Camley, Brian A

2014-01-01T23:59:59.000Z

9

Velocity distribution of high-energy particles and the solar neutrino problem  

E-Print Network (OSTI)

High energy infers high velocity and high velocity is a concept of special relativity. The Maxwellian velocity distribution is corrected to be consistent with special relativity. The corrected distribution reduces to the Maxwellian distribution for small velocities, contains a relatively depleted high-energy tail and vanishes at the velocity of light. This corrected distribution will lower solar neutrino fluxes and change solar neutrino energy spectra but keep solar sound speeds.

Jian-Miin Liu

2001-08-18T23:59:59.000Z

10

The origin of the high-velocity cloud complex C  

E-Print Network (OSTI)

High-velocity clouds consist of cold gas that appears to be raining down from the halo to the disc of the Milky Way. Over the past fifty years, two competing scenarios have attributed their origin either to gas accretion from outside the Galaxy or to circulation of gas from the Galactic disc powered by supernova feedback (galactic fountain). Here we show that both mechanisms are simultaneously at work. We use a new galactic fountain model combined with high-resolution hydrodynamical simulations. We focus on the prototypical cloud complex C and show that it was produced by an explosion that occurred in the Cygnus-Outer spiral arm about 150 million years ago. The ejected material has triggered the condensation of a large portion of the circumgalactic medium and caused its subsequent accretion onto the disc. This fountain-driven cooling of the lower Galactic corona provides the low-metallicity gas required by chemical evolution models of the Milky Way's disc.

Fraternali, F; Armillotta, L; Marinacci, F

2014-01-01T23:59:59.000Z

11

High- and low-temperature-stable thermite composition for producing high-pressure, high-velocity gases  

DOE Patents (OSTI)

A high- and low-temperature-stable thermite composition for producing high-pressure and high-velocity gases comprises an oxidizable metal, an oxidizing reagent, and a high-temperature-stable gas-producing additive selected from the group consisting of metal carbides and metal nitrides.

Halcomb, Danny L. (Camden, OH); Mohler, Jonathan H. (Spring Valley, OH)

1990-10-16T23:59:59.000Z

12

Low inlet gas velocity high throughput biomass gasifier  

DOE Patents (OSTI)

The present invention discloses a novel method of operating a gasifier for production of fuel gas from carbonaceous fuels. The process disclosed enables operating in an entrained mode using inlet gas velocities of less than 7 feet per second, feedstock throughputs exceeding 4000 lbs/ft.sup.2 -hr, and pressures below 100 psia.

Feldmann, Herman F. (Worthington, OH); Paisley, Mark A. (Upper Arlington, OH)

1989-01-01T23:59:59.000Z

13

Hohlraum Designs for High Velocity Implosions on NIF  

SciTech Connect

In this paper, we compare experimental shock and capsule trajectories to design calculations using the radiation-hydrodynamics code HYDRA. The measured trajectories from surrogate ignition targets are consistent with reducing the x-ray flux on the capsule by about 85%. A new method of extracting the radiation temperature as seen by the capsule from x-ray intensity and image data shows that about half of the apparent 15% flux deficit in the data with respect to the simulations can be explained by HYDRA overestimating the x-ray flux on the capsule. The National Ignition Campaign (NIC) point-design target is designed to reach a peak fuel-layer velocity of 370 km/s by ablating 90% of its plastic (CH) ablator. The 192-beam National Ignition Facility laser drives a gold hohlraum to a radiation temperature (T{sub RAD}) of 300 eV with a 20 ns-long, 420 TW, 1.3 MJ laser pulse. The hohlraum x-rays couple to the CH ablator in order to apply the required pressure to the outside of the capsule. In this paper, we compare experimental measurements of the hohlraum T{sub RAD} and the implosion trajectory with design calculations using the code hydra. The measured radial positions of the leading shock wave and the unablated shell are consistent with simulations in which the x-ray flux on the capsule is artificially reduced by 85%. We describe a new method of inferring the T{sub RAD} seen by the capsule from time-dependent x-ray intensity data and static x-ray images. This analysis shows that hydra overestimates the x-ray flux incident on the capsule by {approx}8%.

Meezan, N B; Hicks, D G; Callahan, D A; Olson, R E; Schneider, M S; Thomas, C A; Robey, H F; Celliers, P M; Kline, J K; Dixit, S N; Michel, P A; Jones, O S; Clark, D S; Ralph, J E; Doeppner, T; MacKinnon, A J; Haan, S W; Landen, O L; Glenzer, S H; Suter, L J; Edwards, M J; Macgowan, B J; Lindl, J D; Atherton, L J

2011-10-19T23:59:59.000Z

14

Analysis of particle behavior in High-Velocity Oxy-Fuel thermal spraying process  

Science Journals Connector (OSTI)

This paper analyzes the behavior of coating particle as well as the gas flow both of inside and outside the High-Velocity Oxy-Fuel (HVOF) thermal spraying gun by using quasi-one-dimensional analysis and numerical...

Hiroshi Katanoda; Kazuyasu Matsuo

2003-08-01T23:59:59.000Z

15

Variables Affecting Smooth Particle Hydrodynamics Simulation of High-Velocity Flyer Plate Impact Experiments  

SciTech Connect

This paper describes our work to characterize the variables affecting the smoothed particle hydrodynamics (SPH) method in the LS-DYNA package for simulating high-velocity flyer plate impact experiments. LS-DYNA simulations are compared with one-dimensional experimental data of an oxygen-free high-conductivity (OFHC) copper flyer plate impacting another plate of the same material. The comparison is made by measuring the velocity of a point on the back surface of the impact plate using the velocity interferometer system for any reflector (VISAR) technique.

Somasundaram, Deepak S [UNLV; Trabia, Mohamed [UNLV; O'Toole, Brendan [UNLV; Hixson, Robert S [NSTec

2014-01-23T23:59:59.000Z

16

Moderate Velocity Ball Impact of a Mock High-Explosive  

SciTech Connect

Modeling of thermal and mechanical events in high-explosive materials is complicated by the composite nature of the material, which experiences viscoelastic and plastic deformations and sustains damage in the form of microcracks that can dominate its overall behavior. A mechanical event of interest is projectile interaction with the material, which leads to extreme local deformation and adiabatic heating, which can potentially lead to adverse outcomes in an energetic material. Simulations of such an event predicted large local temperature rises near the path of a spherical projectile, but these were experimentally unconfirmed and hence potentially non-physical. This work concerns the experimental verification of local temperatures both at the surface and in the wake of a spherical projectile penetrating a mock (unreactive) high-explosive at {approx}700 m/s. Fast response thermocouples were embedded radially in a mid-plane of a cylindrical target, which was bonded around the thermocouples with epoxy and recorded by an oscilloscope through a low-pass filter with a bandwidth of 500 Hz. A peak temperature rise of 70 K was measured both at the equator of the projectile and in its wake, in good agreement with the temperature predicted in the minimally distorted elements at those locations by a finite element model in ABAQUS employing the ViscoSCRAM constitutive model. Further work is needed to elucidate the extreme temperature rises in material undergoing crushing or fragmentation, which is difficult to predict with meshed finite element methods due to element distortion, and also challenging to quantify experimentally.

Furmanski, Jevan [Los Alamos National Laboratory; Rae, Philip [Los Alamos National Laboratory; Clements, Bradford E. [Los Alamos National Laboratory

2012-06-05T23:59:59.000Z

17

Velocity of Sound Measurements in High?Pressure, High?Temperature Steam  

Science Journals Connector (OSTI)

Experimental information concerning the acoustic velocity in steam as a function of pressure and temperature is quite limited. Yet it is of particular interest to steam turbine designers who are now planning units as large as 400 000 kw operating at 4500 lb/sq in. and 1200°F so as to increase thermal efficiencies of such units. Apparatus is now in operation for measuring the acoustic velocity up to 2000 lb/sq in. and 750°F using a variable path acoustic interferometer.Measurements are taken at 200?lb/sq in. intervals along a given isotherm using a sound frequency of 750 kc. A special experimental high?pressure boiler is used to generate the steam at the desired pressure and the stem is then increased in temperature by means of a stainless steel superheater before entering the interferometer. The interferometer also of stainless steel is enclosed by an insulated steel vessel maintained at a given constant temperature by another separate steam system. Future work is now being considered up to 6000?lb/sq in. steam pressure based upon results of present experiments.

James Woodburn

1960-01-01T23:59:59.000Z

18

HIGH-RESOLUTION OBSERVATIONS AND THE PHYSICS OF HIGH-VELOCITY CLOUD A0  

SciTech Connect

The neutral hydrogen structure of high-velocity cloud A0 (at about -180 km s{sup -1}) has been mapped with a 9.'1 resolution. Gaussian decomposition of the profiles is used to separately map families of components defined by similarities in center velocities and line widths. About 70% of the H I gas is in the form of a narrow, twisted filament whose typical line widths are of the order of 24 km s{sup -1}. Many bright features with narrow line widths of the order of 6 km s{sup -1}, clouds, are located in and near the filament. A third category with properties between those of the filament and clouds appears in the data. The clouds are not always co-located with the broader line width filament emission as seen projected on the sky. Under the assumption that magnetic fields underlie the presence of the filament, a theorem is developed for its stability in terms of a toroidal magnetic field generated by the flow of gas along field lines. It is suggested that the axial magnetic field strength may be derived from the excess line width of the H I emission over and above that due to kinetic temperature by invoking the role of Alfven waves that create what is in essence a form of magnetic turbulence. At a distance of 200 pc the axial and the derived toroidal magnetic field strengths in the filament are then about 6 {mu}G while for the clouds they are about 4 {mu}G. The dependence of the derived field strength on distance is discussed.

Verschuur, Gerrit L., E-mail: verschuur@aol.com [Physics Department, University of Memphis, Memphis, TN 38152 (United States)

2013-04-01T23:59:59.000Z

19

Critical velocities for deflagration and detonation triggered by voids in a REBO high explosive  

SciTech Connect

The effects of circular voids on the shock sensitivity of a two-dimensional model high explosive crystal are considered. We simulate a piston impact using molecular dynamics simulations with a Reactive Empirical Bond Order (REBO) model potential for a sub-micron, sub-ns exothermic reaction in a diatomic molecular solid. The probability of initiating chemical reactions is found to rise more suddenly with increasing piston velocity for larger voids that collapse more deterministically. A void with radius as small as 10 nm reduces the minimum initiating velocity by a factor of 4. The transition at larger velocities to detonation is studied in a micron-long sample with a single void (and its periodic images). The reaction yield during the shock traversal increases rapidly with velocity, then becomes a prompt, reliable detonation. A void of radius 2.5 nm reduces the critical velocity by 10% from the perfect crystal. A Pop plot of the time-to-detonation at higher velocities shows a characteristic pressure dependence.

Herring, Stuart Davis [Los Alamos National Laboratory; Germann, Timothy C [Los Alamos National Laboratory; Jensen, Niels G [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

20

High-Velocity Oxy-Fuel (HVOF) Suspension Spraying of Mullite Coatings  

Science Journals Connector (OSTI)

Mullite coatings (3Al2O3 · 2SiO2) were deposited by suspension thermal spraying of micron-sized (D50...= 1.8 ?m) feedstock powders, using a high-velocity oxy-fuel gun (HVOF) operated on propylene (DJ-2700) and .....

J. Oberste Berghaus; B.R. Marple

2008-12-01T23:59:59.000Z

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


21

Method and apparatus for optical Doppler tomographic imaging of fluid flow velocity in highly scattering media  

DOE Patents (OSTI)

Optical Doppler tomography permits imaging of fluid flow velocity in highly scattering media. The tomography system combines Doppler velocimetry with high spatial resolution of partially coherent optical interferometry to measure fluid flow velocity at discrete spatial locations. Noninvasive in vivo imaging of blood flow dynamics and tissue structures with high spatial resolutions of the order of 2 to 10 microns is achieved in biological systems. The backscattered interference signals derived from the interferometer may be analyzed either through power spectrum determination to obtain the position and velocity of each particle in the fluid flow sample at each pixel, or the interference spectral density may be analyzed at each frequency in the spectrum to obtain the positions and velocities of the particles in a cross-section to which the interference spectral density corresponds. The realized resolutions of optical Doppler tomography allows noninvasive in vivo imaging of both blood microcirculation and tissue structure surrounding the vessel which has significance for biomedical research and clinical applications.

Nelson, John Stuart (Laguna Niguel, CA); Milner, Thomas Edward (Irvine, CA); Chen, Zhongping (Irvine, CA)

1999-01-01T23:59:59.000Z

22

Electrical method and apparatus for impelling the extruded ejection of high-velocity material jets  

DOE Patents (OSTI)

A method and apparatus (10, 40) for producing high-velocity material jets provided. An electric current pulse generator (14, 42) is attached to an end of a coaxial two-conductor transmission line (16, 44) having an outer cylindrical conductor (18), an inner cylindrical conductor (20), and a solid plastic or ceramic insulator (21) therebetween. A coxial, thin-walled metal structure (22, 30) is conductively joined to the two conductors (18, 20) of the transmission line (16, 44). An electrical current pulse applies magnetic pressure to and possibly explosively vaporizes metal structure (22), thereby collapsing it and impelling the extruded ejection of a high-velocity material jet therefrom. The jet is comprised of the metal of the structure (22), together with the material that comprises any covering layers (32, 34) disposed on the structure. An electric current pulse generator of the explosively driven magnetic flux compression type or variety (42) may be advantageously used in the practice of this invention.

Weingart, Richard C. (Livermore, CA)

1989-01-01T23:59:59.000Z

23

Smith's Cloud: A High-velocity Cloud Colliding with the Milky Way  

E-Print Network (OSTI)

New 21cm HI observations made with the Green Bank Telescope show that the high-velocity cloud known as Smith's Cloud has a striking cometary appearance and many indications of interaction with the Galactic ISM. The velocities of interaction give a kinematic distance of 12.4 +/-1.3 kpc, consistent with the distance derived from other methods. The Cloud is >3 x 1 kpc in size and its tip at (l,b)=(39 deg,-13 deg) is 7.6 kpc from the Galactic center and 2.9 kpc below the Galactic plane. It has greater than 10^6 M solar masses in HI. Its leading section has a total space velocity near 300 km/s, is moving toward the Galactic plane with a velocity of 73+/-26 km/s, and is shedding material to the Galaxy. In the absence of drag the Cloud will cross the plane in about 27 Myr. Smith's Cloud may be an example of the accretion of gas by the Milky Way needed to explain certain persistent anomalies in Galactic chemical evolution.

Lockman, Felix J; Heroux, A J; Langston, Glen I

2008-01-01T23:59:59.000Z

24

Smith's Cloud: A High-velocity Cloud Colliding with the Milky Way  

E-Print Network (OSTI)

New 21cm HI observations made with the Green Bank Telescope show that the high-velocity cloud known as Smith's Cloud has a striking cometary appearance and many indications of interaction with the Galactic ISM. The velocities of interaction give a kinematic distance of 12.4 +/-1.3 kpc, consistent with the distance derived from other methods. The Cloud is >3 x 1 kpc in size and its tip at (l,b)=(39 deg,-13 deg) is 7.6 kpc from the Galactic center and 2.9 kpc below the Galactic plane. It has greater than 10^6 M solar masses in HI. Its leading section has a total space velocity near 300 km/s, is moving toward the Galactic plane with a velocity of 73+/-26 km/s, and is shedding material to the Galaxy. In the absence of drag the Cloud will cross the plane in about 27 Myr. Smith's Cloud may be an example of the accretion of gas by the Milky Way needed to explain certain persistent anomalies in Galactic chemical evolution.

Felix J. Lockman; Robert A. Benjamin; A. J. Heroux; Glen I. Langston

2008-04-25T23:59:59.000Z

25

Multi-Phase Galaxy Formation: High Velocity Clouds and the Missing Baryon Problem  

E-Print Network (OSTI)

The standard treatment of cooling in Cold Dark Matter halos assumes that all of the gas within a ``cooling radius'' cools and contracts monolithically to fuel galaxy formation. Here we take into account the expectation that the hot gas in galactic halos is thermally unstable and prone to fragmentation during cooling and show that the implications are more far-reaching than previously expected: allowing multi-phase cooling fundamentally alters expectations about gas infall in halos and naturally explains the bright-end cutoff in the galaxy luminosity function. We argue that cooling should proceed via the formation of high-density, 10^4 K clouds, pressure-confined within a hot gas background. The background medium has a low density, and can survive as a stable corona with a long cooling time. The fraction of baryons contained in the residual hot core grows with halo mass because the cooling density increases, and this leads to an upper-mass limit in quiescent, non-merged galaxies of ~10^11 Msun. In this scenario, galaxy formation is fueled by the infall of pressure-supported clouds. For Milky-Way-size systems, clouds of mass ~ 5x10^6 Msun that formed or merged within the last several Gyrs should still exist as a residual population in the halo, with a total mass in clouds of ~ 2 x 10^10 Msun. The mass of the Milky Way galaxy is explained naturally in this model, and is a factor of two smaller than would result in the standard treatment without feedback. We expect clouds in galactic halos to be ~ 1 kpc in size and to extend ~150 kpc from galactic centers. The predicted properties of clouds match well the observed radial velocities, angular sizes, column densities, and velocity widths of High Velocity Clouds around our Galaxy. The clouds also explain high-ion absorption systems at z<1.

Ariyeh H. Maller; James S. Bullock

2004-06-28T23:59:59.000Z

26

Diffusion velocity correlation for nuclear graphite gasification at high temperature and low Reynolds numbers  

SciTech Connect

The safety analysis of High-Temperature and Very High Temperature gas-cooled Reactors requires reliable estimates of nuclear graphite gasification as a function of temperature, among other parameters, in the unlikely event of an air ingress accident. Although the rates of the prevailing chemical reactions increase exponentially with temperature, graphite gasification at high temperatures is limited by the oxygen diffusion through the boundary layer. The effective diffusion velocity depends on the total flow rate and pressure of the bulk air-gas mixture. This paper develops a semi-empirical Sherwood number correlation for calculating the oxygen diffusion velocity. The correlation is based on a compiled database of the results of convective heat transfer experiments with wires and cylinders of different diameters in air, water and paraffin oil at 0.006 {<=} Re {<=} 1,604 and 0.068 {<=} Sc {<=} 35.2, and of mass transfer experiments at 4.8 {<=} Re {<=} 77 and 1,300 {<=} Sc {<=} 2,000. The developed correlation is within {+-} 8% of the compiled database of 567 data points and consistent with reported gasification rate measurements at higher temperatures in experiments using different size specimens of nuclear graphite grades of NBG-18 and NB-25, IG-11, IG-110 and IG-430 in atmospheric air at 0.08 {<=} Re {<=} 30. Unlike the Graetz solution that gives a constant Sh of 3.66 at Re {<=} 1.0, the present correlation shows Sh decreases monotonically to much lower values with decreasing Re. (authors)

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

2012-07-01T23:59:59.000Z

27

Seismic Technology Adapted to Analyzing and Developing Geothermal Systems Below Surface-Exposed High-Velocity Rocks  

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

Improved seismic imaging of geology across high-velocity Earth surfaces will allow more rigorous evaluation of geothermal prospects beneath volcanic outcrops. Seismic-based quantification of fracture orientation and intensity will result in optimal positioning of geothermal wells.

28

Numerical modeling of in-flight characteristics of inconel 625 particles during high-velocity oxy-fuel thermal spraying  

Science Journals Connector (OSTI)

A computational fluid dynamics (CFD) model is developed to predict particle dynamic behavior in a high-velocity oxyfuel (HVOF) thermal spray gun in which premixed oxygen and propylene are ... 20 to 40 µm. At a pa...

S. Gu; D. G. McCartney; C. N. Eastwick; K. Simmons

2004-01-01T23:59:59.000Z

29

A DETAILED KINEMATIC MAP OF CASSIOPEIA A'S OPTICAL MAIN SHELL AND OUTER HIGH-VELOCITY EJECTA  

SciTech Connect

We present three-dimensional (3D) kinematic reconstructions of optically emitting material in the young Galactic supernova remnant Cassiopeia A (Cas A). These Doppler maps have the highest spectral and spatial resolutions of any previous survey of Cas A and represent the most complete catalog of its optically emitting material to date. We confirm that the bulk of Cas A's optically bright ejecta populate a torus-like geometry tilted approximately 30 Degree-Sign with respect to the plane of the sky with a -4000 to +6000 km s{sup -1} radial velocity asymmetry. Near-tangent viewing angle effects and an inhomogeneous surrounding circumstellar material/interstellar medium environment suggest that this geometry and velocity asymmetry may not be faithfully representative of the remnant's true 3D structure or the kinematic properties of the original explosion. The majority of the optical ejecta are arranged in several well-defined and nearly circular ring-like structures with diameters between approximately 30'' (0.5 pc) and 2' (2 pc). These ejecta rings appear to be a common phenomenon of young core-collapse remnants and may be associated with post-explosion input of energy from plumes of radioactive {sup 56}Ni-rich ejecta that rise, expand, and compress non-radioactive material. Our optical survey encompasses Cas A's faint outlying ejecta knots and exceptionally high-velocity NE and SW streams of S-rich debris often referred to as ''jets''. These outer knots, which exhibit a chemical make-up suggestive of an origin deep within the progenitor star, appear to be arranged in opposing and wide-angle outflows with opening half-angles of Almost-Equal-To 40 Degree-Sign.

Milisavljevic, Dan [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA, 02138 (United States); Fesen, Robert A., E-mail: dmilisav@cfa.harvard.edu [6127 Wilder Lab, Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States)

2013-08-01T23:59:59.000Z

30

The Ultra Luminous X-ray sources in the High Velocity System of NGC 1275  

E-Print Network (OSTI)

We report the results of a study of X-ray point sources coincident with the High Velocity System (HVS) projected in front of NGC 1275. A very deep X-ray image of the core of the Perseus cluster made with the Chandra Observatory has been used. We find a population of Ultra-Luminous X-ray sources (ULX; 7 sources with LX [0.5-7 keV] > 7x10^39 erg/s). As with the ULX populations in the Antennae and Cartwheel galaxies, those in the HVS are associated with a region of very active star formation. Several sources have possible optical counterparts found on HST images, although the X-ray brightest one does not. Absorbed power-law models fit the X-ray spectra, with most having a photon index between 2 and 3.

O. Gonzalez-Martin; A. C. Fabian; J. S. Sanders

2006-01-09T23:59:59.000Z

31

An X-ray absorption analysis of the high-velocity system in NGC 1275  

E-Print Network (OSTI)

We present an X-ray absorption analysis of the high-velocity system (HVS) in NGC 1275 using results from a deep 200 ks Chandra observation. We are able to describe the morphology of the HVS in more detail than ever before. We present an HST image for comparison, and note close correspondence between the deepest X-ray absorption and the optical absorption. A column density map of the HVS shows an average column density NH of 1x10^21 cm^-2 with a range from ~5x10^20 to 5x10^21 cm^-2. From the NH map we calculate a total mass for the absorbing gas in the HVS of (1.32+-0.05)x10^9 solar masses at solar abundance. 75 per cent of the absorbing mass is contained in the four regions of deepest absorption. We examine temperature maps produced by spectral fitting and find no direct evidence for shocked gas in the HVS. Using deprojection methods and the depth of the observed absorption, we are able to put a lower limit on the distance of the HVS from the nucleus of 57 kpc, showing that the HVS is quite separate from the body of NGC 1275.

K. Gillmon; J. S. Sanders; A. C. Fabian

2003-10-28T23:59:59.000Z

32

The Smith Cloud: high-velocity accretion and dark-matter confinement  

E-Print Network (OSTI)

The Smith Cloud is a massive system of metal-poor neutral and ionized gas M_gas >= 2x10^6 M_sun) that is presently moving at high velocity (V_GSR ~300 km s^-1) with respect to the Galaxy at a distance of 12 kpc from the Sun. The kinematics of the cloud's cometary tail indicates that the gas is in the process of accretion onto the Galaxy, as first discussed by Lockman et al. (2008). Here, we re-investigate the cloud's orbit by considering the possibility that the cloud is confined by a dark matter halo. This is required for the cloud to survive its passage through the Galactic corona. We consider three possible models for the dark matter halo (NFW, Einasto, Burkert) including the effects of tidal disruption and ram-pressure stripping during the cloud's infall onto and passage through the Galactic disk. For the NFW and Einasto dark-matter models, we are able to determine reasonable initial conditions for the Smith Cloud, although this is only marginally possible with the Burkert model. For all three models, the...

Nichols, M

2009-01-01T23:59:59.000Z

33

Searching for Dark Matter Annihilation in the Smith High-Velocity Cloud  

E-Print Network (OSTI)

Recent observations suggest that some high-velocity clouds may be confined by massive dark matter halos. In particular, the proximity and proposed dark matter content of the Smith Cloud make it a tempting target for the indirect detection of dark matter annihilation. We argue that the Smith Cloud may be a better target than some Milky Way dwarf spheroidal satellite galaxies and use gamma-ray observations from the Fermi Large Area Telescope to search for a dark matter annihilation signal. No significant gamma-ray excess is found coincident with the Smith Cloud, and we set strong limits on the dark matter annihilation cross section assuming a spatially-extended dark matter profile consistent with dynamical modeling of the Smith Cloud. Notably, these limits exclude the canonical thermal relic cross section ($\\sim 3\\times10^{-26}{\\rm cm}^{3}{\\rm s}^{-1}$) for dark matter masses $\\lesssim 30$ GeV annihilating via the $b \\bar b$ or $\\tau^{+}\\tau^{-}$ channels for certain assumptions of the dark matter density profile; however, uncertainties in the dark matter content of the Smith Cloud may significantly weaken these constraints.

Alex Drlica-Wagner; German A. Gomez-Vargas; John W. Hewitt; Tim Linden; Luigi Tibaldo

2014-06-30T23:59:59.000Z

34

detonation velocity  

Science Journals Connector (OSTI)

detonation velocity, detonation rate, velocity of detonation, V.O.D., detonating velocity, rate of detonation, detonating rate, detonation speed, detonating speed, speed of detonation ? Detonationsge...

2014-08-01T23:59:59.000Z

35

Boiling during high-velocity impact of water droplets on a hot stainless steel surface  

Science Journals Connector (OSTI)

...rho, V and p 0 are water density, impact velocity and atmospheric pressure, respectively. Assuming water vapour is a perfect...droplet-on-demand generator. Exp. Fluids. 34...of hot surfaces with water sprays. J. Heat Treating...

2006-01-01T23:59:59.000Z

36

High-resolution imaging of velocity-controlled molecular collisions using counterpropagating beams  

E-Print Network (OSTI)

We present ultrahigh-resolution measurements of state-to-state inelastic differential cross sections for NO-Ne and NO-Ar collisions, obtained by combining the Stark deceleration and velocity map imaging techniques. We show that for counterpropagating crossed beam geometries, the effect of the velocity spreads of the reagent beams on the angular resolution of the images is minimized. Futhermore, the counterpropagating geometry results in images that are symmetric with respect to the relative velocity vector. This allows for the use of inverse Abel transformation methods that enhance the resolution further. State-resolved diffraction oscillations in the differential cross sections are measured with an angular resolution approaching 0.3$^\\circ$. Distinct structures observed in the cross sections gauge the quality of recent \\emph{ab initio} potential energy surfaces for NO-rare gas atom collisions with unprecedented precision.

Vogels, Sjoerd N; von Zastrow, Alexander; Groenenboom, Gerrit C; van der Avoird, Ad; van de Meerakker, Sebastiaan Y T

2014-01-01T23:59:59.000Z

37

Characterization and Fabrication of Spoke Cavities for High-Velocity Applications  

SciTech Connect

A 500 MHz, velocity-of-light, two-spoke cavity has been designed and optimized for possible use in a compact light source. Here we present the mechanical analysis and steps taken in fabrication of this cavity at Jefferson Lab.

Hopper, Christopher S. [Old Dominion University, Norfolk, VA (United States); Park, HyeKyoung [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Delayen, Jean R. [Old Dominion University, Norfolk, VA (United States)

2014-02-01T23:59:59.000Z

38

ULTRA-COMPACT HIGH VELOCITY CLOUDS AS MINIHALOS AND DWARF GALAXIES  

SciTech Connect

We present dark matter minihalo models for the Ultra-Compact, High-Velocity H I Clouds (UCHVCs) recently discovered in the 21 cm ALFALFA survey. We assume gravitational confinement of 10{sup 4} K H I gas by flat-cored dark-matter subhalos within the Local Group. We show that for flat cores, typical (median) tidally stripped cosmological subhalos at redshift z = 0 have dark-matter masses of ?10{sup 7} M{sub ?} within the central 300 pc (independent of total halo mass), consistent with the 'Strigari mass scale' observed in low-luminosity dwarf galaxies. Flat-cored subhalos also resolve the mass discrepancy between simulated and observed satellites around the Milky Way. For the UCHVCs, we calculate the photoionization-limited hydrostatic gas profiles for any distance-dependent total observed H I mass and predict the associated (projected) H I half-mass radii, assuming the clouds are embedded in distant (d ?> 300 kpc) and unstripped subhalos. For a typical UCHVC (0.9 Jy km s{sup –1}), we predict physical H I half-mass radii of 0.18 to 0.35 kpc (or angular sizes of 0.'6 to 2.'1) for distances ranging from 300 kpc to 2 Mpc. As a consistency check, we model the gas-rich dwarf galaxy Leo T, for which there is a well-resolved H I column density profile and a known distance (420 kpc). For Leo T, we find that a subhalo with M{sub 300} = 8 (± 0.2) × 10{sup 6} M{sub ?} best fits the observed H I profile. We derive an upper limit of P{sub HIM} ?< 150 cm{sup –3} K for the pressure of any enveloping hot intergalactic medium gas at the distance of Leo T. Our analysis suggests that some of the UCHVCs may in fact constitute a population of 21 cm-selected but optically faint dwarf galaxies in the Local Group.

Faerman, Yakov; Sternberg, Amiel [Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Ramat Aviv 69978 (Israel); McKee, Christopher F., E-mail: yakovfae@post.tau.ac.il [Department of Physics and Department of Astronomy, University of California at Berkeley, Berkeley, CA 94720 (United States)

2013-11-10T23:59:59.000Z

39

Stochastic simulation for the propagation of high-frequency acoustic waves through a random velocity field  

SciTech Connect

In-service inspection of Sodium-Cooled Fast Reactors (SFR) requires the development of non-destructive techniques adapted to the harsh environment conditions and the examination complexity. From past experiences, ultrasonic techniques are considered as suitable candidates. The ultrasonic telemetry is a technique used to constantly insure the safe functioning of reactor inner components by determining their exact position: it consists in measuring the time of flight of the ultrasonic response obtained after propagation of a pulse emitted by a transducer and its interaction with the targets. While in-service the sodium flow creates turbulences that lead to temperature inhomogeneities, which translates into ultrasonic velocity inhomogeneities. These velocity variations could directly impact the accuracy of the target locating by introducing time of flight variations. A stochastic simulation model has been developed to calculate the propagation of ultrasonic waves in such an inhomogeneous medium. Using this approach, the travel time is randomly generated by a stochastic process whose inputs are the statistical moments of travel times known analytically. The stochastic model predicts beam deviations due to velocity inhomogeneities, which are similar to those provided by a determinist method, such as the ray method.

Lu, B.; Darmon, M.; Leymarie, N.; Chatillon, S.; Potel, C. [CEA, LIST, F-91191 Gif-sur-Yvette (France); Laboratoire d'Acoustique de l'Universite du Maine (LAUM), UMR CNRS 6613, 72085 Le Mans Cedex 9 (France)

2012-05-17T23:59:59.000Z

40

The influence of the Al stabilizer layer thickness on the normal zone propagation velocity in high current superconductors  

E-Print Network (OSTI)

The stability of high-current superconductors is challenging in the design of superconducting magnets. When the stability requirements are fulfilled, the protection against a quench must still be considered. A main factor in the design of quench protection systems is the resistance growth rate in the magnet following a quench. The usual method for determining the resistance growth in impregnated coils is to calculate the longitudinal velocity with which the normal zone propagates in the conductor along the coil windings. Here, we present a 2D numerical model for predicting the normal zone propagation velocity in Al stabilized Rutherford NbTi cables with large cross section. By solving two coupled differential equations under adiabatic conditions, the model takes into account the thermal diffusion and the current redistribution process following a quench. Both the temperature and magnetic field dependencies of the superconductor and the metal cladding materials properties are included. Unlike common normal zon...

Shilon, I; Langeslag, S A E; Martins, L P; Kate, H H J ten

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high velocity sdhv" 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

EVIDENCE OF HOT HIGH VELOCITY PHOTOIONIZED PLASMA FALLING ON ACTIVELY ACCRETING T TAURI STARS  

SciTech Connect

The He II (1640 Å) line and the resonance doublet of N V (UV1) provide a good diagnostic tool to constrain the excitation mechanism of hot (T{sub e} > 40,000 K) atmospheric/magnetospheric plasmas in T Tauri stars (TTSs). Making use of the data available in the Hubble Space Telescope archive, this work shows that there are at least two distinct physical components contributing to the radiation in these tracers: the accretion flow sliding on the magnetosphere and the atmosphere. The N V profiles in most sources are symmetric and at rest with respect to the star. The velocity dispersion of the profile increases from non-accreting (? = 40 km s{sup –1}) to accreting (? = 120 km s{sup –1}) TTSs, suggesting that the macroturbulence field in the line formation region decreases as the stars approach the main sequence. Evidence of the N V line being formed in a hot solar-like wind has been found in RW Aur, HN Tau, and AA Tau. The He II profile has a strong narrow component that dominates the line flux; the dispersion of this component ranges from 20 to 60 km s{sup –1}. Current data suggest that both accretion shocks and atmospheric emission might contribute to the line flux. In some sources, the He II line shows a broad and redward-shifted emission component often accompanied by semiforbidden O III] emission that has a critical electron density of ?3.4 × 10{sup 10} cm{sup 3}. In spite of their different origins (inferred from the kinematics of the line formation region), N V and He II fluxes are strongly correlated, with only the possible exception of some of the heaviest accretors.

Gómez de Castro, Ana Ines [Grupo de Investigación Complutense AEGORA and S.D. Astronomía y Geodesia, Fac. de CC Matemáticas, Universidad Complutense, E-28040 Madrid (Spain)

2013-10-01T23:59:59.000Z

42

High-Frequency Effect Due to the Axial Drift Velocity of a Plasma Column  

Science Journals Connector (OSTI)

The scattering of a plane electromagnetic wave with normal incidence (E field perpendicular to the axis) by a plasma column in the presence of a static magnetic induction B0 has been studied earlier. A heretofore unexplained effect, however, is the existence of a scattered axial field EZ even when B0=0. A mechanism responsible for this coupling between the EZ and the transverse E field, in the absence of B0, is investigated here, namely the role of an axial drift velocity vd. The effect observed is a resonance peak of EZ occurring at the same density for which there exists a resonance of the scattered transverse E field which is well explained by a uniform cold-plasma model. The same model is therefore assumed here. In this approximation the plasma can be described by a surface charge density ? due to the HF polarization which gives rise to a surface current density K=?vd. The boundary conditions then lead to the existence of an EZ which, for B0=0, has a sin? dependence when the exciting field has a cos? dependence. When B0?0, a more complicated theoretical spectrum is obtained. Both the position and the angular dependence of the resonances are in very good agreement with experimental data. The effect predicted by this model is, however, more than an order of magnitude below that observed in a mercury plasma column. This phenomenon can be described as the plasma radio-frequency analog of the static field induced by the Roentgen-Eichenwald current.

A. M. Messiaen and P. E. Vandenplas

1966-09-09T23:59:59.000Z

43

GALACTIC ALL-SKY SURVEY HIGH-VELOCITY CLOUDS IN THE REGION OF THE MAGELLANIC LEADING ARM  

SciTech Connect

We present a catalog of high-velocity clouds in the region of the Magellanic Leading Arm. The catalog is based on neutral hydrogen (H I) observations from the Parkes Galactic All-Sky Survey. Excellent spectral resolution allows clouds with narrow-line components to be resolved. The total number of detected clouds is 419. We describe the method of cataloging and present the basic parameters of the clouds. We discuss the general distribution of the high-velocity clouds and classify the clouds based on their morphological type. The presence of a significant number of head-tail clouds and their distribution in the region is discussed in the context of Magellanic System simulations. We suggest that ram-pressure stripping is a more important factor than tidal forces for the morphology and formation of the Magellanic Leading Arm and that different environmental conditions might explain the morphological difference between the Magellanic Leading Arm and Magellanic Stream. We also discuss a newly identified population of clouds that forms the LA IV and a new diffuse bridge-like feature connecting the LA II and III complexes.

For, Bi-Qing; Staveley-Smith, Lister [International Centre for Radio Astronomy Research, University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009 (Australia)] [International Centre for Radio Astronomy Research, University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009 (Australia); McClure-Griffiths, N. M., E-mail: biqing.for@uwa.edu.au [Australia Telescope National Facility, CSIRO Astronomy and Space Science, PO Box 76, Epping, NSW 1710 (Australia)

2013-02-10T23:59:59.000Z

44

Multi-point, high-speed passive ion velocity distribution diagnostic on the Pegasus Toroidal Experiment  

SciTech Connect

A passive ion temperature polychromator has been deployed on Pegasus to study power balance and non-thermal ion distributions that arise during point source helicity injection. Spectra are recorded from a 1 m F/8.6 Czerny-Turner polychromator whose output is recorded by an intensified high-speed camera. The use of high orders allows for a dispersion of 0.02 A/mm in 4th order and a bandpass of 0.14 A ({approx}13 km/s) at 3131 A in 4th order with 100 {mu}m entrance slit. The instrument temperature of the spectrometer is 15 eV. Light from the output of an image intensifier in the spectrometer focal plane is coupled to a high-speed CMOS camera. The system can accommodate up to 20 spatial points recorded at 0.5 ms time resolution. During helicity injection, stochastic magnetic fields keep T{sub e} low ({approx}100 eV) and thus low ionization impurities penetrate to the core. Under these conditions, high core ion temperatures are measured (T{sub i} Almost-Equal-To 1.2 keV, T{sub e} Almost-Equal-To 0.1 keV) using spectral lines from carbon III, nitrogen III, and boron IV.

Burke, M. G.; Fonck, R. J.; Bongard, M. W.; Schlossberg, D. J.; Winz, G. R. [Department of Engineering Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States)

2012-10-15T23:59:59.000Z

45

Laser-based diagnostics for density, temperature, velocity, and dissociation fraction in high temperature hydrogen flows  

SciTech Connect

This paper is essentially a review of the current state of the art in hydrogen atom and hydrogen molecule diagnostics. This paper contains some of our own results and ideas along with results from many other laboratories. This is not intended to be an exhaustive review; instead it summarizes some techniques which we believe are ideally suited as diagnostics for high temperature hydrogen which are of paramount importance for the Space Exploration Initiative (SEI). 31 refs., 1 fig.

Sappey, A.D.; Funk, D.J.

1991-01-01T23:59:59.000Z

46

Velocity determination from velocity spectra  

E-Print Network (OSTI)

. Lithologic and structural information can bc inferred from the interval velocities and thicknesses. Actual seismic exploration data (which are twelvefold sub- surface coverage data taken at Niller County, Arkansas) were used to make the actual velocity...) with decreasing increment of normal incidence time and rms velocity, 2) with in- creasing interval between the initial and final values of time and TRACE NO. & SHOT-GEOPHONE DISTANCE l 2 3 4 3 6 X, X X 4 Xs X~ RMS VELOCITY V ca Jo M A tD M NNO = J o) y...

Yang, Sung Jin

2012-06-07T23:59:59.000Z

47

High frequency sound velocity in the glass former 2Ca(NO3)2?3KNO3: Molecular dynamics simulations  

Science Journals Connector (OSTI)

Molecular dynamics simulations of the fragile glass-forming liquid 2Ca(NO3)2?3KNO3 (CKN) were performed from its molten state at 800K down to its glassy state at 250K. Time correlation functions of mass current fluctuations were calculated in order to investigate sound waves of high wave vectors, 0.18high frequency (THz) sound velocity of CKN was obtained from the slope of the dispersion curve of excitation energy of acoustic modes, ?(k), as a function of temperature across the glass transition. The temperature dependence of the sound velocity of longitudinal acoustic modes is discontinuous in a range that is higher than the glass transition temperature Tg estimated from the T dependence of density and energy. This result demonstrates that the high frequency sound velocity probes the transition from liquidlike to solidlike regimes at a temperature higher than the Tg of the simulated material. The sound velocity of transverse acoustic (TA) modes presents discontinuity at the same value of the thermodynamic derived Tg. It is proposed that the distinct behavior of high frequency TA modes is due to fast reorientational motions of NO3? anions that are able to relieve local shear stresses.

Mauro C. C. Ribeiro

2007-04-06T23:59:59.000Z

48

Development of a High Resolution X-Ray Imaging Crystal Spectrometer for Measurement of Ion-Temperature and Rotation-Velocity Profiles in Fusion Energy Research Plasmas  

SciTech Connect

A new imaging high resolution x-ray crystal spectrometer (XCS) has been developed to measure continuous profiles of ion temperature and rotation velocity in fusion plasmas. Following proof-of-principle tests on the Alcator C-Mod tokamak and the NSTX spherical tokamak, and successful testing of a new silicon, pixilated detector with 1 MHz count rate capability per pixel, an imaging XCS is being designed to measure full profiles of Ti and v? on C-Mod. The imaging XCS design has also been adopted for ITER. Ion-temperature uncertainty and minimum measurable rotation velocity are calculated for the C-Mod spectrometer. The affects of x-ray and uclear-radiation background on the measurement uncertainties are calculated to predict performance on ITER.

Hill, K W; Broennimann, Ch; Eikenberry, E F; Ince-Cushman, A; Lee, S G; Rice, J E; Scott, S

2008-01-29T23:59:59.000Z

49

Performance of high-velocity oxy-fuel-sprayed chromium carbide-nickel chromium coating in an actual boiler environment of a thermal power plant  

SciTech Connect

The present study aims to evaluate the performance of a high-velocity oxy-fuel (HVOF)-sprayed Cr{sub 3}C{sub 2}-NiCr (chromium carbide-nickel chromium) coating on a nickel-based super-alloy in an actual industrial environment of a coal-fired boiler, with the objective to protect the boiler super-heater and reheater tubes from hot corrosion. The tests were performed in the platen super heater zone of a coal-fired boiler for 1,000 h at 900 degrees C under cyclic conditions. The Cr{sub 3}C{sub 2}-NiCr coating imparted the necessary protection to the nickel-based super alloy in the given environment. The dense and flat splat structure of the coating, and the formation of oxides of chromium and nickel and their spinels, might have protected the substrate super alloy from the inward permeation of corrosive species.

Sidhu, T.S.; Prakash, S.; Agrawal, R.D. [Industrial Technology Institute, Roorkee (India)

2007-09-15T23:59:59.000Z

50

Unitaxial constant velocity microactuator  

DOE Patents (OSTI)

A uniaxial drive system or microactuator capable of operating in an ultra-high vacuum environment is disclosed. The mechanism includes a flexible coupling having a bore therethrough, and two clamp/pusher assemblies mounted in axial ends of the coupling. The clamp/pusher assemblies are energized by voltage-operated piezoelectrics therewithin to operatively engage the shaft and coupling causing the shaft to move along its rotational axis through the bore. The microactuator is capable of repeatably positioning to sub-nanometer accuracy while affording a scan range in excess of 5 centimeters. Moreover, the microactuator generates smooth, constant velocity motion profiles while producing a drive thrust of greater than 10 pounds. The system is remotely controlled and piezoelectrically driven, hence minimal thermal loading, vibrational excitation, or outgassing is introduced to the operating environment. 10 figs.

McIntyre, T.J.

1994-06-07T23:59:59.000Z

51

The Effects of Magnetizer Velocity on Magnetic Flux Leakage Signals  

Science Journals Connector (OSTI)

In many magnetic flux leakage applications, the nondestructive inspection constraints suggest the use of high inspection velocities. However, high inspection velocities can compromise the ability to detect and ch...

J. Bruce Nestleroth; Richard J. Davis

1993-01-01T23:59:59.000Z

52

LAB #2 Escape Velocity  

E-Print Network (OSTI)

(6) The above calculations ignore the effect of air resistance on the object. We assume that resistance is proportional to velocity and decreases with increasing

2007-02-02T23:59:59.000Z

53

The Effects of Flux Leakage Magnetizer Velocity on Volumetric Defect Signals  

Science Journals Connector (OSTI)

The inspection requirements of the hundreds of thousands of miles of pipeline worldwide necessitates the use of high inspection velocities. Unfortunately, high inspection velocities can compromise the ability ...

Richard J. Davis; J. Bruce Nestleroth

1995-01-01T23:59:59.000Z

54

Radial velocities of population II binary stars. II  

E-Print Network (OSTI)

Here we publish the second list of radial velocities for 91 Hipparcos stars, mostly high transverse velocity binaries without previous radial velocity measurements. The measurements of radial velocities are done with a CORAVEL-type radial velocity spectrometer with an accuracy better than 1 km/s. We also present the information on eight new radial velocity variables - HD 29696, HD 117466AB, BD +28 4035AB, BD +30 2129A, BD +39 1828AB, BD +69 230A, BD +82 565A and TYC 2267-1300-1 - found from our measurements. Two stars (HD 27961AB and HD 75632AB) are suspected as possible radial velocity variables.

A. Bartkevicius; J. Sperauskas

2006-01-10T23:59:59.000Z

55

ARM - Measurement - Vertical velocity  

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

govMeasurementsVertical velocity govMeasurementsVertical velocity ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Vertical velocity The component of the velocity vector, along the local vertical. Categories Atmospheric State Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments CO2FLX : Carbon Dioxide Flux Measurement Systems ECOR : Eddy Correlation Flux Measurement System KAZR : Ka ARM Zenith Radar MMCR : Millimeter Wavelength Cloud Radar SODAR : Mini Sound Detection and Ranging

56

Vertical Velocity Focus Group  

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

Velocity Focus Group Velocity Focus Group ARM 2008 Science Team Meeting Norfolk, VA March 10-14 Background Vertical velocity measurements have been at the top of the priority list of the cloud modeling community for some time. Doppler measurements from ARM profiling radars operating at 915-MHz, 35-GHz and 94-GHz have been largely unexploited. The purpose of this new focus group is to develop vertical velocity ARM products suitable for modelers. ARM response to their request has been slow. Most ARM instruments are suitable for cloud observations and have limited capabilities in precipitation Using ARM datasets for evaluating and improving cloud parameterization in global climate models (GCMs) is not straightforward, due to gigantic scale mismatches. Consider this... Looking only vertically drastically limits opportunities

57

Velocity of the electric arc in a plasmatron discharge chamber  

Science Journals Connector (OSTI)

An experimental investigation of the velocity of a high-current arc with air injection in the discharge chamber of a coaxial sectioned plasmatron is described. The experiments showed that the velocity of the c...

A. S. Shaboltas

1969-09-01T23:59:59.000Z

58

Velocity distributions in clusters of galaxies  

E-Print Network (OSTI)

We employ a high-resolution dissipationless N-body simulation of a galaxy cluster to investigate the impact of subhalo selection on the resulting velocity distributions. Applying a lower limit on the present bound mass of subhalos leads to high subhalo velocity dispersions compared to the diffuse dark matter (positive velocity bias) and to a considerable deviation from a Gaussian velocity distribution (kurtosis -0.6). However, if subhalos are required to exceed a minimal mass before accretion onto the host, the velocity bias becomes negligible and the velocity distribution is close to Gaussian (kurtosis -0.15). Recently it has been shown that the latter criterion results in subhalo samples that agree well with the observed number-density profiles of galaxies in clusters. Therefore we argue that the velocity distributions of galaxies in clusters are essentially un-biased. The comparison of the galaxy velocity distribution and the sound speed, derived from scaling relations of X-ray observations, results in an average Mach number of 1.24. Altogether 65% of the galaxies move supersonically and 8% have Mach numbers larger than 2 with respect to the intra cluster gas.

A. Faltenbacher; J. Diemand

2006-02-08T23:59:59.000Z

59

The velocity campaign for ignition on NIF  

SciTech Connect

Achieving inertial confinement fusion ignition requires a symmetric, high velocity implosion. Experiments show that we can reach 95 {+-} 5% of the required velocity by using a 420 TW, 1.6 MJ laser pulse. In addition, experiments with a depleted uranium hohlraum show an increase in capsule performance which suggests an additional 18 {+-} 5 {mu}m/ns of velocity with uranium hohlraums over gold hohlraums. Combining these two would give 99 {+-} 5% of the ignition velocity. Experiments show that we have the ability to tune symmetry using crossbeam transfer. We can control the second Legendre mode (P2) by changing the wavelength separation between the inner and outer cones of laser beams. We can control the azimuthal m = 4 asymmetry by changing the wavelength separation between the 23.5 and 30 degree beams on NIF. This paper describes our 'first pass' tuning the implosion velocity and shape on the National Ignition Facility laser [Moses et al., Phys. Plasmas, 16, 041006 (2009)].

Callahan, D. A.; Meezan, N. B.; Glenzer, S. H.; MacKinnon, A. J.; Benedetti, L. R.; Bradley, D. K.; Celeste, J. R.; Celliers, P. M.; Dixit, S. N.; Doeppner, T.; Dzentitis, E. G.; Glenn, S.; Haan, S. W.; Haynam, C. A.; Hicks, D. G.; Hinkel, D. E.; Jones, O. S.; Landen, O. L.; London, R. A.; MacPhee, A. G. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

2012-05-15T23:59:59.000Z

60

Perspectives on Deposition Velocity  

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

Deposition Deposition Velocity ... Going down the rabbit hole to explain that sinking feeling Brian DiNunno, Ph.D. Project Enhancement Corporation June 6 th , 2012 Discussion Framework  Development of the HSS Deposition Velocity Safety Bulletin  Broader discussion of appropriate conservatism within dispersion modeling and DOE-STD-3009 DOE-STD-3009 Dose Comparison "General discussion is provided for source term calculation and dose estimation, as well as prescriptive guidance for the latter. The intent is that calculations be based on reasonably conservative estimates of the various input parameters." - DOE-STD-3009, Appendix A.3 DOE-STD-3009 Dispersion

Note: This page contains sample records for the topic "high velocity sdhv" 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

Velocity pump reaction turbine  

DOE Patents (OSTI)

An expanding hydraulic/two-phase velocity pump reaction turbine including a dual concentric rotor configuration with an inter-rotor annular flow channel in which the inner rotor is mechanically driven by the outer rotor. In another embodiment, the inner rotor is immobilized and provided with gas recovery ports on its outer surface by means of which gas in solution may be recovered. This velocity pump reaction turbine configuration is capable of potential energy conversion efficiencies of up to 70%, and is particularly suited for geothermal applications.

House, Palmer A. (Walnut Creek, CA)

1982-01-01T23:59:59.000Z

62

Velocity pump reaction turbine  

DOE Patents (OSTI)

An expanding hydraulic/two-phase velocity pump reaction turbine including a dual concentric rotor configuration with an inter-rotor annular flow channel in which the inner rotor is mechanically driven by the outer rotor. In another embodiment, the inner rotor is immobilized and provided with gas recovery ports on its outer surface by means of which gas in solution may be recovered. This velocity pump reaction turbine configuration is capable of potential energy conversion efficiencies of up to 70%, and is particularly suited for geothermal applications.

House, Palmer A. (Walnut Creek, CA)

1984-01-01T23:59:59.000Z

63

TEA-0008 - In the Matter of Unico, Inc. | Department of Energy  

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

08 - In the Matter of Unico, Inc. 08 - In the Matter of Unico, Inc. TEA-0008 - In the Matter of Unico, Inc. The present Appeal filed by Unico, Inc. (Unico), relates to a Decision and Order issued by the Office of Hearings and Appeals (OHA) on December 20, 2005, granting exception relief to Energy Savings Products, Ltd. (ESP) from the provisions of 10 C.F.R. Part 430, pertaining to energy conservation standards for central air conditioners and heat pumps (Air Conditioner Standards). Energy Savings Products, Ltd., 29 DOE & 81,015 (2005) (ESP). ESP sought and obtained exception relief on the basis that the firm is a manufacturer of small duct, high velocity (SDHV) air conditioning equipment, and would suffer a gross inequity, serious hardship and an unfair distribution of burdens if forced to comply with

64

TEE-0026 - In the Matter of Energy Savings Products, Ltd. | Department of  

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

6 - In the Matter of Energy Savings Products, Ltd. 6 - In the Matter of Energy Savings Products, Ltd. TEE-0026 - In the Matter of Energy Savings Products, Ltd. This Decision and Order considers an Application for Exception filed by Energy Savings Products, Ltd. (ESP) seeking exception relief from the provisions of 10 C.F.R. Part 430, pertaining to energy conservation standards for central air conditioners and heat pumps (Air Conditioner Standards). ESP is a manufacturer of small duct, high velocity (SDHV) air conditioning equipment. In its exception request, ESP asserts that the firm will suffer a gross inequity, serious hardship and an unfair distribution of burdens if forced to comply with the 13 SEER energy efficiency standard effective January 2006, 10 C.F.R. § 430.32(c). If its Application for Exception were granted, the

65

TEE-0011 - In the Matter of Unico, Inc. | Department of Energy  

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

1 - In the Matter of Unico, Inc. 1 - In the Matter of Unico, Inc. TEE-0011 - In the Matter of Unico, Inc. This Decision and Order considers Applications for Exception filed by SpacePak and Unico, Inc. (Unico), seeking exception relief from the provisions of in C.F.R. Part 430, pertaining to energy conservation standards for central air conditioners and heat pumps (Air Conditioner Standards). SpacePak and Unico are manufacturers of small duct, high velocity (SDHV) air conditioning equipment. In their exception requests, SpacePak and Unico assert that they will suffer a serious hardship and an unfair distribution of burdens if forced to comply with the 13 SEER energy efficiency standard effective January 2006, 10 C.F.R. § 430.32(c). If their Applications for Exception were granted, the firms would receive exception relief from the revised

66

P:\DECISION\0026.tee.wpd  

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

, 2005 , 2005 DECISION AND ORDER OFFICE OF HEARINGS AND APPEALS Application for Exception Case Name: Energy Savings Products, Ltd. Date of Filing: September 28, 2005 Case Number: TEE-0026 This Decision and Order considers an Application for Exception filed by Energy Savings Products, Ltd. (ESP) seeking exception relief from the provisions of 10 C.F.R. Part 430, pertaining to energy conservation standards for central air conditioners and heat pumps (Air Conditioner Standards). ESP is a manufacturer of small duct, high velocity (SDHV) air conditioning equipment. In its exception request, ESP asserts that the firm will suffer a gross inequity, serious hardship and an unfair distribution of burdens if forced to comply with the 13 SEER energy efficiency standard effective

67

Microsoft Word - 0008.tea.wpd  

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

June 30, 2006 June 30, 2006 DECISION AND ORDER OFFICE OF HEARINGS AND APPEALS Appeal Case Name: Unico, Inc. Date of Filing: January 19, 2006 Case Number: TEA-0008 The present Appeal filed by Unico, Inc. (Unico), relates to a Decision and Order issued by the Office of Hearings and Appeals (OHA) on December 20, 2005, granting exception relief to Energy Savings Products, Ltd. (ESP) from the provisions of 10 C.F.R. Part 430, pertaining to energy conservation standards for central air conditioners and heat pumps (Air Conditioner Standards). Energy Savings Products, Ltd., 29 DOE & 81,015 (2005) (ESP). ESP sought and obtained exception relief on the basis that the firm is a manufacturer of small duct, high velocity (SDHV) air conditioning equipment, and would suffer a gross inequity,

68

TEE-0010 - In the Matter of SpacePak | Department of Energy  

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

0 - In the Matter of SpacePak 0 - In the Matter of SpacePak TEE-0010 - In the Matter of SpacePak This Decision and Order considers Applications for Exception filed by SpacePak and Unico, Inc. (Unico), seeking exception relief from the provisions of in C.F.R. Part 430, pertaining to energy conservation standards for central air conditioners and heat pumps (Air Conditioner Standards). SpacePak and Unico are manufacturers of small duct, high velocity (SDHV) air conditioning equipment. In their exception requests, SpacePak and Unico assert that they will suffer a serious hardship and an unfair distribution of burdens if forced to comply with the 13 SEER energy efficiency standard effective January 2006, 10 C.F.R. § 430.32(c). If their Applications for Exception were granted, the firms would receive exception relief from the revised

69

TEE-0010  

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

4, 2004 4, 2004 DECISION AND ORDER OFFICE OF HEARINGS AND APPEALS Applications for Exception Case Names: SpacePak Unico, Inc. Date of Filing: May 24, 2004 Case Numbers: TEE-0010 TEE-0011 This Decision and Order considers Applications for Exception filed by SpacePak and Unico, Inc. (Unico), seeking exception relief from the provisions of in C.F.R. Part 430, pertaining to energy conservation standards for central air conditioners and heat pumps (Air Conditioner Standards). SpacePak and Unico are manufacturers of small duct, high velocity (SDHV) air conditioning equipment. In their exception requests, SpacePak and Unico assert that they will suffer a serious hardship and an unfair distribution of burdens if forced to comply with the 13 SEER energy efficiency standard effective January 2006, 10 C.F.R. § 430.32(c). If their Applications for Exception were

70

MASSIVE AND NEWLY DEAD: DISCOVERY OF A SIGNIFICANT POPULATION OF GALAXIES WITH HIGH-VELOCITY DISPERSIONS AND STRONG BALMER LINES AT z {approx} 1.5 FROM DEEP KECK SPECTRA AND HST/WFC3 IMAGING  

SciTech Connect

We present deep Keck/LRIS spectroscopy and Hubble Space Telescope/WFC3 imaging in the rest-frame optical for a sample of eight galaxies at z {approx} 1.5 with high photometrically determined stellar masses. The data are combined with five Very Large Telescope/X-Shooter spectra. We find that these 13 galaxies have high velocity dispersions, with a median of {sigma} = 301 km s{sup -1}. This high value is consistent with their relatively high stellar masses and compact sizes. We study their stellar populations using the strength of Balmer absorption lines, which are not sensitive to dust absorption. We find a large range in Balmer absorption strength, with many galaxies showing very strong lines indicating young ages. The median H{delta}{sub A} equivalent width, determined directly or inferred from the H10 line, is 5.4 A, indicating a luminosity-weighted age of {approx}1 Gyr. Although this value may be biased toward higher values because of selection effects, high-dispersion galaxies with such young ages are extremely rare in the local universe. Interestingly, we do not find a simple correlation with rest-frame U - V color: some of the reddest galaxies have very strong Balmer absorption lines, which may indicate the importance of multiple bursts of star formation. These results demonstrate that many high-dispersion galaxies at z {approx} 1.5 were recently quenched. This implies that there must be a population of star-forming progenitors at z {approx} 2 with high velocity dispersions or linewidths, which are notoriously absent from CO/H{alpha} selected surveys.

Bezanson, Rachel; Van Dokkum, Pieter [Department of Astronomy, Yale University, New Haven, CT 06520-8101 (United States); Van de Sande, Jesse; Franx, Marijn [Sterrewacht Leiden, Leiden University, NL-2300 RA Leiden (Netherlands); Kriek, Mariska [Department of Astronomy, University of California, Berkeley, CA 94720 (United States)

2013-02-10T23:59:59.000Z

71

Seismic velocity estimation from time migration  

E-Print Network (OSTI)

Seismic images . . . . . . . . . . . . . . . . .Algorithms producing the seismic velocities from thethe Dix velocities and the true seismic velocities in 2D . .

Cameron, Maria Kourkina

2007-01-01T23:59:59.000Z

72

ARM - Measurement - Hydrometeor fall velocity  

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

fall velocity fall velocity ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Hydrometeor fall velocity Fall velocity of hydrometeors (e.g. rain, snow, graupel, hail). Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments DISDROMETER : Impact Disdrometer LDIS : Laser Disdrometer WSACR : Scanning ARM Cloud Radar, tuned to W-Band (95GHz) Field Campaign Instruments DISDROMETER : Impact Disdrometer PDI : Phase Doppler Interferometer

73

Determination of hydrogen cluster velocities and comparison with numerical calculations  

SciTech Connect

The use of powerful hydrogen cluster jet targets in storage ring experiments led to the need of precise data on the mean cluster velocity as function of the stagnation temperature and pressure for the determination of the volume density of the target beams. For this purpose a large data set of hydrogen cluster velocity distributions and mean velocities was measured at a high density hydrogen cluster jet target using a trumpet shaped nozzle. The measurements have been performed at pressures above and below the critical pressure and for a broad range of temperatures relevant for target operation, e.g., at storage ring experiments. The used experimental method is described which allows for the velocity measurement of single clusters using a time-of-flight technique. Since this method is rather time-consuming and these measurements are typically interfering negatively with storage ring experiments, a method for a precise calculation of these mean velocities was needed. For this, the determined mean cluster velocities are compared with model calculations based on an isentropic one-dimensional van der Waals gas. Based on the obtained data and the presented numerical calculations, a new method has been developed which allows to predict the mean cluster velocities with an accuracy of about 5%. For this two cut-off parameters defining positions inside the nozzle are introduced, which can be determined for a given nozzle by only two velocity measurements.

Täschner, A.; Köhler, E.; Ortjohann, H.-W.; Khoukaz, A. [Institut für Kernphysik, Westfälische Wilhelms-Universität Münster, D-48149 Münster (Germany)] [Institut für Kernphysik, Westfälische Wilhelms-Universität Münster, D-48149 Münster (Germany)

2013-12-21T23:59:59.000Z

74

Velocity Distributions from Nonextensive Thermodynamics  

E-Print Network (OSTI)

There is no accepted mechanism that explains the equilibrium structures that form in collisionless cosmological N-body simulations. Recent work has identified nonextensive thermodynamics as an innovative approach to the problem. The distribution function that results from adopting this framework has the same form as for polytropes, but the polytropic index is now related to the degree of nonextensiveness. In particular, the nonextensive approach can mimic the equilibrium structure of dark matter density profiles found in simulations. We extend the investigation of this approach to the velocity structures expected from nonextensive thermodynamics. We find that the nonextensive and simulated N-body rms-velocity distributions do not match one another. The nonextensive rms-velocity profile is either monotonically decreasing or displays little radial variation, each of which disagrees with the rms-velocity distributions seen in simulations. We conclude that the currently discussed nonextensive models require further modifications in order to corroborate dark matter halo simulations. (adapted from TeX)

Eric I. Barnes; Liliya L. R. Williams; Arif Babul; Julianne J. Dalcanton

2006-10-05T23:59:59.000Z

75

Measurement of velocity field in parametrically excited solitary waves  

E-Print Network (OSTI)

Paramerically excited solitary waves emerge as localized structures in high-aspect-ratio free surfaces subject to vertical vibrations. Herein, we provide the first experimental characterization of the hydrodynamics of thess waves using Particle Image Velocimetry. We show that the underlying velocity field of parametrically excited solitary waves is mainly composed by an oscillatory velocity field. Our results confirm the accuracy of Hamiltonian models with added dissipation in describing this field. Remarkably, our measurements also uncover the onset of a streaming velocity field which is shown to be as important as other crucial nonlinear terms in the current theory. The observed streaming pattern is particularly interesting due to the presence of oscillatory meniscii.

Gordillo, Leonardo

2014-01-01T23:59:59.000Z

76

BENCAP, LLC: CAPSULE VELOCITY TEST  

SciTech Connect

Ben Cap, LLC, has a technology that utilizes bebtonite to plug wells. The bentonite is encapsulated in a cardboard capsule, droped down to the bottom of the well where it is allowed to hydrate, causing the bentonite to expand and plug the well. This method of plugging a well is accepted in some, but not all states. This technology can save a significant amount of money when compared to cementing methods currently used to plug and abandon wells. The test objective was to obtain the terminal velocity of the capsule delivery system as it drops through a column of water in a wellbore. Once the terminal velocity is known, the bentonite swelling action can be timed not to begin swelling until it reaches the bottom of the well bore. The results of the test showed that an average speed of 8.93 plus or minus 0.12 ft/sec was achieved by the capsule as it was falling through a column of water. Plotting the data revealed a very linear function with the capsules achieving terminal velocity shortly after being released. The interference of the capsule impacting the casing was not readily apparent in any of the runs, but a siginal sampling anomaly was present in one run. Because the anomaly was so brief and not present in any of the other runs, no solid conclusions could be drawn. Additional testing would be required to determine the effects of capsules impacting a fluid level that is not at surface.

Meidinger, Brian

2005-09-07T23:59:59.000Z

77

Stress anisotropy and velocity anisotropy in low porosity shale  

Science Journals Connector (OSTI)

Shales are known for often marked intrinsic anisotropy of many of their properties, including strength, permeability and velocity for example. In addition, it is well known that anisotropic stress fields can also have a significant impact on anisotropy of velocity, even in an isotropic medium. This paper sets out to investigate the ultrasonic velocity response of well-characterised low porosity shales from the Officer Basin in Western Australia to both isotropic and anisotropic stress fields and to evaluate the velocity response to the changing stress field. During consolidated undrained multi-stage triaxial tests on core plugs cut normal to bedding, Vpv increases monotonically with increasing effective stress and Vs1 behaves similarly although with some scatter. Vph and Vsh remain constant initially but then decrease within each stage of the multi-stage test, although velocity from stage to stage at any given differential stress increases. This has the impact of decreasing both P-wave (?) and S-wave anisotropy (?) through application of differential stress within each loading stage. However, increasing the magnitude of an isotropic stress field has little effect on the velocity anisotropies. The intrinsic anisotropy of the shale remains reasonably high at the highest confining pressures. The results indicate the magnitude and orientation of the stress anisotropy with respect to the shale microfabric has a significant impact on the velocity response to changing stress fields.

U. Kuila; D.N. Dewhurst; A.F. Siggins; M.D. Raven

2011-01-01T23:59:59.000Z

78

Particle Velocity and Deposition Efficiency in the Cold Spray Process  

SciTech Connect

Copper powder was sprayed by the cold-gas dynamic method. In-flight particle velocities were measured with a laser-two-focus system as a function of process parameters such as gas temperature, gas pressure, and powder feed rate. Particle velocities were uniform in a relatively large volume within the plume and agreed with theoretical predictions. The presence of the substrate was found to have no significant effect on particle velocities. Cold-spray deposition efficiencies were measured on aluminum substrates as a function of particle velocity and incident angle of the plume. Deposition efficiencies of up to 95% were achieved. The critical velocity for deposition was determined to be about 640 meters per second. This work investigates both the in-flight characteristics of copper particles in a supersonic cold-spray plume and the build-up of the subsequent coating on aluminum substrates. Velocities were found to be relatively constant within a large volume of the plume. Particle counts dropped off sharply away from the central axis. The presence of a substrate was found to have no effect on the velocity of the particles. A substantial mass-loading effect on the particle velocity was observed; particle velocities begin to drop as the mass ratio of powder to gas flow rates exceeds 3%. The measured variation of velocity with gas pressure and pre-heat temperature was in fairly good agreement with theoretical predictions. Helium may be used as the driving gas instead of air in order to achieve higher particle velocities for a given temperature and pressure. Coating deposition efficiencies were found to increase with particle velocity and decrease with gun- substrate angle. There did not appear to be any dependence of the deposition efficiency on coating thickness. A critical velocity for deposition of about 640 mk appears to fit the data well. The cold-spray technique shows promise as a method for the deposition of materials which are thermally sensitive or may experience rapid oxidation under typical thermal spray conditions. High deposition efficiencies are achievable for certain coating-substrate conditions. Work remains to determine the material and microstructural properties which govern the coating process.

Dykhuizen, R.C.; Gilmore, D.L.; Neiser, R.A.; Roemer, T.J.; Smith, M.F.

1998-11-12T23:59:59.000Z

79

Property:Maximum Velocity(m/s) | Open Energy Information  

Open Energy Info (EERE)

Velocity(m/s) Velocity(m/s) Jump to: navigation, search Property Name Maximum Velocity(m/s) Property Type String Pages using the property "Maximum Velocity(m/s)" Showing 25 pages using this property. (previous 25) (next 25) A Alden Large Flume + 0.9 + B Bucknell Hydraulic Flume + 2.7 + C Carderock Maneuvering & Seakeeping Basin + 7.2 + Carderock Rotating Arm Tow Tank + 25.8 + Carderock Tow Tank 1 + 9.3 + Carderock Tow Tank 2 + 10.3 + Carderock Tow Tank 3 + 25.8 + Chase Tow Tank + 2.5 + D Davidson Laboratory Tow Tank + 18.3 + H Haynes Tow Tank + 1.8 + I Ice Towing Tank + 0.5 + L Lakefront Tow Tank + 2.7 + M MHL Free Surface Channel + 2 + MHL High Speed Cavitation + 25.9 + MHL Tow Tank + 6.7 + MIT Tow Tank + 1.5 + MMA Tugboat/ Barge/ Vessel + 5.1 + Maine Tow Tank + 3 +

80

Property:Velocity(m/s) | Open Energy Information  

Open Energy Info (EERE)

Velocity(m/s) Velocity(m/s) Jump to: navigation, search Property Name Velocity(m/s) Property Type String Pages using the property "Velocity(m/s)" Showing 21 pages using this property. A Alden Small Flume + >0.9 + B Bucknell Hydraulic Flume + 2.7 + C Carderock 2-ft Variable Pressure Cavitation Water Tunnel + 17 + Carderock 3-ft Variable Pressure Cavitation Water Tunnel + 25.8 + Carderock Circulating Water Channel + 5.2 + Carderock Large Cavitation Tunnel + 18 + Carderock Subsonic Wind Tunnel + 83.8 + D DeFrees Flume 1 + 2 + DeFrees Flume 2 + 2 + DeFrees Flume 3 + 2 + DeFrees Flume 4 + 2 + M MHL Free Surface Channel + 2 + MHL High Speed Cavitation + 25.9 + MHL Student Tunnel + 4.6 + P Penn Large Water Tunnel + 16.8 + Penn Small Water Tunnel + 21 + S SAFL Channel + 6.1 +

Note: This page contains sample records for the topic "high velocity sdhv" from the National Library of EnergyBeta (NLEBeta).
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81

Optic-microwave mixing velocimeter for superhigh velocity measurement  

SciTech Connect

The phenomenon that a light beam reflected off a moving object experiences a Doppler shift in its frequency underlies practical interferometric techniques for remote velocity measurements, such as velocity interferometer system for any reflector (VISAR), displacement interferometer system for any reflector (DISAR), and photonic Doppler velocimetry (PDV). While VISAR velocimeters are often bewildered by the fringe loss upon high-acceleration dynamic process diagnosis, the optic-fiber velocimeters such as DISAR and PDV, on the other hand, are puzzled by high velocity measurement over 10 km/s, due to the demand for the high bandwidth digitizer. Here, we describe a new optic-microwave mixing velocimeter (OMV) for super-high velocity measurements. By using currently available commercial microwave products, we have constructed a simple, compact, and reliable OMV device, and have successfully obtained, with a digitizer of bandwidth 6 GH only, the precise velocity history of an aluminum flyer plate being accelerated up to 11.2 km/s in a three stage gas-gun experiment.

Weng Jidong; Wang Xiang; Tao Tianjiong; Liu Cangli; Tan Hua [Laboratory for Shock Waves and Detonation Physics Research, Institute of Fluid Physics, P.O. Box 919-102, Mianyang, Sichuan 621900 (China)

2011-12-15T23:59:59.000Z

82

DOE Workshop - Deposition Velocity Status  

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

Delivering DOE's Vision for the Delivering DOE's Vision for the East Tennessee Technology Park Mission Safely Delivering the Department of Energy's Vision for the East Tennessee Technology Park Mission DOE Workshop Deposition Velocity Status Mike Hitchler, Manager Nuclear Facility Safety June 5, 2012 Safely Delivering DOE's Vision for the East Tennessee Technology Park Mission Existing UCOR Analyses * UCOR facilities at East Tennessee Technology Park (ETTP) and Oak Ridge National Laboratory (ORNL) use various plume models depending on when they were developed and by whom. - Some use MACCS or MACCS2 for dispersion evaluation. (~5 locations) - LLLW uses ingestion modeling (multiple locations)

83

Newberry EGS Seismic Velocity Model  

DOE Data Explorer (OSTI)

We use ambient noise correlation (ANC) to create a detailed image of the subsurface seismic velocity at the Newberry EGS site down to 5 km. We collected continuous data for the 22 stations in the Newberry network, together with 12 additional stations from the nearby CC, UO and UW networks. The data were instrument corrected, whitened and converted to single bit traces before cross correlation according to the methodology in Benson (2007). There are 231 unique paths connecting the 22 stations of the Newberry network. The additional networks extended that to 402 unique paths crossing beneath the Newberry site.

Dennise Templeton

84

Newberry EGS Seismic Velocity Model  

SciTech Connect

We use ambient noise correlation (ANC) to create a detailed image of the subsurface seismic velocity at the Newberry EGS site down to 5 km. We collected continuous data for the 22 stations in the Newberry network, together with 12 additional stations from the nearby CC, UO and UW networks. The data were instrument corrected, whitened and converted to single bit traces before cross correlation according to the methodology in Benson (2007). There are 231 unique paths connecting the 22 stations of the Newberry network. The additional networks extended that to 402 unique paths crossing beneath the Newberry site.

Dennise Templeton

2013-10-01T23:59:59.000Z

85

P And S Wave Velocity Determination  

E-Print Network (OSTI)

There are three general methods that can be used to determine formation velocities from full waveform logs. The first approach is to make use of the data from the entire waveform. This type of velocity analysis is performed ...

Willis, M. E.

1983-01-01T23:59:59.000Z

86

Noise pair velocity and range echo location system  

DOE Patents (OSTI)

An echo-location method for microwaves, sound and light capable of using incoherent and arbitrary waveforms of wide bandwidth to measure velocity and range (and target size) simultaneously to high resolution. Two interferometers having very long and nearly equal delays are used in series with the target interposed. The delays can be longer than the target range of interest. The first interferometer imprints a partial coherence on an initially incoherent source which allows autocorrelation to be performed on the reflected signal to determine velocity. A coherent cross-correlation subsequent to the second interferometer with the source determines a velocity discriminated range. Dithering the second interferometer identifies portions of the cross-correlation belonging to a target apart from clutter moving at a different velocity. The velocity discrimination is insensitive to all slowly varying distortions in the signal path. Speckle in the image of target and antenna lobing due to parasitic reflections is minimal for an incoherent source. An arbitrary source which varies its spectrum dramatically and randomly from pulse to pulse creates a radar elusive to jamming. Monochromatic sources which jigger in frequency from pulse to pulse or combinations of monochromatic sources can simulate some benefits of incoherent broadband sources. Clutter which has a symmetrical velocity spectrum will self-cancel for short wavelengths, such as the apparent motion of ground surrounding target from a sidelooking airborne antenna.

Erskine, David J. (Oakland, CA)

1999-01-01T23:59:59.000Z

87

Noise pair velocity and range echo location system  

DOE Patents (OSTI)

An echo-location method for microwaves, sound and light capable of using incoherent and arbitrary waveforms of wide bandwidth to measure velocity and range (and target size) simultaneously to high resolution is disclosed. Two interferometers having very long and nearly equal delays are used in series with the target interposed. The delays can be longer than the target range of interest. The first interferometer imprints a partial coherence on an initially incoherent source which allows autocorrelation to be performed on the reflected signal to determine velocity. A coherent cross-correlation subsequent to the second interferometer with the source determines a velocity discriminated range. Dithering the second interferometer identifies portions of the cross-correlation belonging to a target apart from clutter moving at a different velocity. The velocity discrimination is insensitive to all slowly varying distortions in the signal path. Speckle in the image of target and antenna lobing due to parasitic reflections is minimal for an incoherent source. An arbitrary source which varies its spectrum dramatically and randomly from pulse to pulse creates a radar elusive to jamming. Monochromatic sources which jigger in frequency from pulse to pulse or combinations of monochromatic sources can simulate some benefits of incoherent broadband sources. Clutter which has a symmetrical velocity spectrum will self-cancel for short wavelengths, such as the apparent motion of ground surrounding target from a sidelooking airborne antenna. 46 figs.

Erskine, D.J.

1999-02-16T23:59:59.000Z

88

Calculation of the Electron Velocity Distribution Function in a Plasma Slab with Large Temperature and Density Gradients  

Science Journals Connector (OSTI)

...velocity. The distribution function for the...calculate the distribution function as a...region of the quiet Sun using several data-sets for temperature and density gradients...high-velocity tail of the distribution function. The...

1990-01-01T23:59:59.000Z

89

Embedded Fiber Optic Probes to Measure Detonation Velocities Using the Photonic Doppler Velocimeter  

SciTech Connect

Detonation velocities for high explosives can be in the 7 to 8 km/s range. Previous work has shown that these velocities may be measured by inserting an optical fiber probe into the explosive assembly and recording the velocity time history using a Fabry-Perot velocimeter. The measured velocity using this method, however, is the actual velocity multiplied times the refractive index of the fiber core, which is on the order of 1.5. This means that the velocimeter diagnostic must be capable of measuring velocities as high as 12 km/s. Until recently, a velocity of 12 km/s was beyond the maximum velocity limit of a homodyne-based velocimeter. The limiting component in a homodyne system is usually the digitizer. Recently, however, digitizers have come on the market with 20 GHz bandwidth and 50 GS/s sample rate. Such a digitizer coupled with high bandwidth detectors now have the total bandwidth required to make velocity measurements in the 12 km/s range. This paper describes measurements made of detonation velocities using a high bandwidth homodyne system.

Hare, D E; Holtkamp, D B; Strand, O T

2010-03-02T23:59:59.000Z

90

Augmented geophysical data interpretation through automated velocity picking in semblance velocity images  

Science Journals Connector (OSTI)

Velocity picking is the problem of picking velocity-time pairs based on a coherence metric between multiple seismic signals. Coherence as a function of velocity and time can be expressed as a 2D color semblance velocity image. Currently, humans pick ...

J. Ross Beveridge; Charlie Ross; Darrell Whitley; Barry Fish

2002-07-01T23:59:59.000Z

91

Low Velocity Boron Micro-Pellet Injector For Edge And Core Impurity Transport Measurements  

E-Print Network (OSTI)

velocities to insure penetration into the cores of high density, high temperature reactor grade plasmas at controlled penetration depths in the edge plasma. Applications involving short penetration distances and;3 required ablation rate. This paper describes a simple Low Velocity Boron Micro-Pellet Injector that has

92

A unified gas kinetic scheme with moving mesh and velocity space adaptation  

Science Journals Connector (OSTI)

There is great difficulty for direct Boltzmann solvers to simulate high Knudsen number flow due to the severe steep slope and high concentration of the gas distribution function in a local particle velocity space. Local mesh adaptation becomes necessary ... Keywords: Adaptive velocity space, Moving mesh, Rarefied gas, Unified gas kinetic scheme

Songze Chen; Kun Xu; Cunbiao Lee; Qingdong Cai

2012-08-01T23:59:59.000Z

93

Ultra-precise particle velocities in pulsed supersonic beams  

SciTech Connect

We describe an improved experimental method for the generation of cold, directed particle bunches, and the highly accurate determination of their velocities in a pulsed supersonic beam, allowing for high-resolution experiments of atoms, molecules, and clusters. It is characterized by a pulsed high pressure jet source with high brilliance and optimum repeatability, a flight distance of few metres that can be varied with a tolerance of setting of 50 {mu}m, and a precision in the mean flight time of particles of better than 10{sup -4}. The technique achieves unmatched accuracies in particle velocities and kinetic energies and also permits the reliable determination of enthalpy changes with very high precision.

Christen, Wolfgang [Institut fuer Chemie, Humboldt-Universitaet zu Berlin, Brook-Taylor-Strasse 2, 12489 Berlin (Germany)

2013-07-14T23:59:59.000Z

94

Cap Bubble Drift Velocity in a Confined Test Section  

SciTech Connect

In the two-group interfacial area transport equation, bubbles are categorized into two groups, i.e., spherical/distorted bubbles as group 1 and cap/slug/churn-turbulent bubbles as group 2. The bubble rise velocities for both groups of bubbles may be estimated by the drift flux model by applying different distribution parameters and drift velocities for both groups. However, the drift velocity for group 2 bubbles is not always applicable (when the wall effect becomes important) as in the current test loop of interest where the flow channel is confined by two parallel flat walls, with a dimension of 200-mm in width and 10-mm in gap. The previous experiments indicated that no stable slug flow existed in this test section, which was designed to permit visualization of the flow patterns and bubble characteristics without the distortion associated with curved surfaces. In fact, distorted cap bubbly and churn-turbulent flow was observed. Therefore, it is essential to developed a correlation for cap bubble drift velocity in this confined flow channel. Since the rise velocity of a cap bubble depends on its size, a high-speed movie camera is used to capture images of cap bubbles to obtain the bubble size information. Meanwhile, the rise velocity of cap and elongated bubbles (called cap bubbles hereafter) is investigated by examining the captured images frame by frame. As a result, the conventional correlation of drift velocity for slug bubbles is modified and acceptable agreements between the measurements and correlation estimation are achieved.

Xiaodong Sun; Seungjin Kim; Mamoru Ishii; Frank W. Lincoln; Stephen G. Beus

2002-10-09T23:59:59.000Z

95

Electromagnetic Energy Velocity in Slow Light  

Science Journals Connector (OSTI)

Group and electromagnetic energy velocities in structural and material slow light are compared. They are equal for structural slow light; the enhancement of linear and nonlinear...

Santagiustina, Marco

96

Field comparison of the point velocity probe with other groundwater velocity measurement methods  

E-Print Network (OSTI)

Field testing of a new tool for measuring groundwater velocities at the centimeter scale, the point velocity probe (PVP), was undertaken at Canadian Forces Base, Borden, Ontario, Canada. The measurements were performed in ...

Labaky, W.; Devlin, J. F.; Gillham, R. W.

2009-03-14T23:59:59.000Z

97

Impact Velocity (2011) | National Nuclear Security Administration  

National Nuclear Security Administration (NNSA)

Impact Velocity (2011) | National Nuclear Security Administration Impact Velocity (2011) | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > Media Room > Video Gallery > Impact Velocity (2011) Impact Velocity (2011) Impact Velocity (2011) From: NNSANews Views: 388 2 ratings Time: 02:26 More in Science & Technology See video Facebook Twitter

98

Observation of Resonant Behavior in the Energy Velocity of Diffused Light  

SciTech Connect

In this Letter we demonstrate Mie resonances mediated transport of light in randomly arranged, monodisperse dielectric spheres packed at high filling fractions. By means of both static and dynamic optical experiments we show resonant behavior in the key transport parameters and, in particular, we find that the energy transport velocity, which is lower than the group velocity, also displays a resonant behavior.

Sapienza, R.; Garcia, P. D.; Blanco, A.; Lopez, C. [Instituto de Ciencia de Materiales de Madrid (CSIC) and Unidad Asociada CSIC-UVigo, Cantoblanco 28049 Madrid (Spain); Bertolotti, J.; Wiersma, D. S. [European Laboratory for Nonlinear Spectroscopy and INFM-BEC, 50019 Sesto Fiorentino (Florence) (Italy); Martin, M. D.; Vina, L. [Departamento de Fisica de Materiales, Universidad Autonoma de Madrid, Cantoblanco 28049 Madrid (Spain)

2007-12-07T23:59:59.000Z

99

Modeling velocity dispersion In Gypsy site, Oklahoma  

E-Print Network (OSTI)

Discrepancies in interval velocities estimated from vertical well measurements made with different source central frequencies at Gypsy site could be primarily explained in terms of intrinsic attenuation. Four intervals ...

Alsaadan, Sami Ibrahim

2010-01-01T23:59:59.000Z

100

Acoustic measurement of potato cannon velocity  

E-Print Network (OSTI)

This article describes measurement of potato cannon velocity with a digitized microphone signal. A microphone is attached to the potato cannon muzzle and a potato is fired at an aluminum target about 10 m away. The potato's flight time can be determined from the acoustic waveform by subtracting the time in the barrel and time for sound to return from the target. The potato velocity is simply the flight distance divided by the flight time.

Courtney, M; Courtney, Amy; Courtney, Michael

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high velocity sdhv" 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

Numerical experiments of fracture-induced velocity and attenuation anisotropy  

Science Journals Connector (OSTI)

......Plata, La Plata, Argentina 4 Department of...phase velocities, energy velocities (wavefronts...112-200801-00952 (CONICET, Argentina). Appendix Appendix...qSV or v SH. The energy-velocity vector...phase velocities, energy velocities (wavefronts...de Buenos Aires Argentina 1179 1191 Geophysical......

J. M. Carcione; S. Picotti; J. E. Santos

2012-12-01T23:59:59.000Z

102

Radial velocities and binarity of southern SIM grid stars  

E-Print Network (OSTI)

We present analysis of precision radial velocities (RV) of 1134 mostly red giant stars in the southern sky, selected as candidate astrometric grid objects for the Space Interferometry Mission (SIM). Only a few (typically, 2 or 3) spectroscopic observations per star have been collected, with the main goal of screening binary systems. The estimated rate of spectroscopic binarity in this sample of red giants is 32% at the 0.95 confidence level, and 46% at the 0.75 confidence. The true binarity rate is likely to be higher, because our method is not quite sensitive to very wide binaries and low-mass companions. The estimated lower and upper bounds of stellar RV jitter for the entire sample are 24 and 51 m/s, respectively; the adopted mean value is 37 m/s. A few objects of interest are identified with large variations of radial velocities, implying abnormally high mass ratios.

Makarov, Valeri V

2014-01-01T23:59:59.000Z

103

Faster-Than-Light Group Velocities and Causality Violation  

Science Journals Connector (OSTI)

...research-article Faster-Than-Light Group Velocities and Causality...group velocities in excess of the speed of light does not imply causality violation...phase velocity shall exceed the speed of light. Application of the theorem leads...

1970-01-01T23:59:59.000Z

104

Pneumatic cleaning of sugarcane utilizing a high velocity air jet  

E-Print Network (OSTI)

- oped to cope with the increased amount of trash present in unburned sugarcane. This research involved the testing and computer simulation of a chopper air jet nozzle assembly. The experimental test setup included a two-stage conveyor. This conveyor... of cleaning produced by the system and the amount of momentum produced by the air jet. When unburned, untopped sugarcane was fed. into the chopper air jet nozzle assembly, a result of 9/~ trash in the bottom conveyor was achieved, A value of 14/ trash...

Fisher, John Ray

2012-06-07T23:59:59.000Z

105

Relation between plasma plume density and gas flow velocity in atmospheric pressure plasma  

SciTech Connect

We have studied atmospheric pressure plasma generated using a quartz tube, helium gas, and copper foil electrode by applying RF high voltage. The atmospheric pressure plasma in the form of a bullet is released as a plume into the atmosphere. To study the properties of the plasma plume, the plasma plume current is estimated from the difference in currents on the circuit, and the drift velocity is measured using a photodetector. The relation of the plasma plume density n{sub plu}, which is estimated from the current and the drift velocity, and the gas flow velocity v{sub gas} is examined. It is found that the dependence of the density on the gas flow velocity has relations of n{sub plu} ? log(v{sub gas}). However, the plasma plume density in the laminar flow is higher than that in the turbulent flow. Consequently, in the laminar flow, the density increases with increasing the gas flow velocity.

Yambe, Kiyoyuki; Taka, Shogo; Ogura, Kazuo [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan)] [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan)

2014-04-15T23:59:59.000Z

106

ARM - Evaluation Product - Convective Vertical Velocity  

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

ProductsConvective Vertical Velocity ProductsConvective Vertical Velocity Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : Convective Vertical Velocity 2011.04.25 - 2011.05.23 Site(s) SGP General Description Convective processes play an important role in Earth's energy balance by distributing heat and moisture throughout the atmosphere. In particular, vertical air motions associated with these processes are inherently linked to the life cycle of these convective systems and are therefore directly tied to their energy budget. However, direct measurements of vertical air motions (e.g., in situ aircraft observations) are sparse, making it difficult to compare them with numerical model output, which relies on convective parameterization schemes that have yet to be extensively

107

Sound velocity bound and neutron stars  

E-Print Network (OSTI)

It has been conjectured that the velocity of sound in any medium is smaller than the velocity of light in vacuum divided by $\\sqrt{3}$. Simple arguments support this bound in non-relativistic and/or weakly coupled theories. The bound has been demonstrated in several classes of strongly coupled theories with gravity duals and is saturated only in conformal theories. We point out that the existence of neutron stars with masses around two solar masses combined with the knowledge of the equation of state of hadronic matter at "low" densities is in strong tension with this bound.

Paulo F. Bedaque; Andrew W. Steiner

2015-01-25T23:59:59.000Z

108

Augmented Geophysical Data Interpretation Through Automated Velocity Picking in Semblance Velocity Images  

E-Print Network (OSTI)

University Fort Collins, CO 80523 ross@cs.colostate.edu Barry Fish Sun Microsystems (Previously at Landmark Graphics) Denver, CO Barry.Fish@central.sun.com Abstract Velocity Picking is the problem of picking velocity-time pairs based on a coherence metric between multiple seismic signals. Coherence as a function

Whitley, Darrell

109

Velocity Shear Stabilization of Centrifugally Confined Plasma  

Science Journals Connector (OSTI)

A magnetized, centrifugally confined plasma is subjected to a 3D MHD stability test. Ordinarily, the system is expected to be grossly unstable to “flute” interchanges of field lines. Numerical simulation shows though that the system is stable on account of velocity shear. This allows consideration of a magnetically confined plasma for thermonuclear fusion that has a particularly simple coil configuration.

Yi-Min Huang and A. B. Hassam

2001-11-16T23:59:59.000Z

110

LATTICE BOLTZMANN SCHEMES WITH RELATIVE VELOCITIES  

E-Print Network (OSTI)

LATTICE BOLTZMANN SCHEMES WITH RELATIVE VELOCITIES FRANÃ?OIS DUBOIS, TONY FEVRIER, AND BENJAMIN GRAILLE Abstract. In this contribution, a new class of lattice Boltzmann schem- es is introduced is then performed to derive the equivalent equations up to third order accuracy. Introduction The lattice Boltzmann

Boyer, Edmond

111

Localized velocity anomalies in the lower mantle  

Science Journals Connector (OSTI)

......projection centred on the Argentina source region. The location...approximately 80" from the Argentina source region. S-waves...Bolivia are dominated by SV energy, and large Sp precursors...closer to the stations than Argentina. Lower mantle velocity anomalies......

Thorne Lay

1983-02-01T23:59:59.000Z

112

Bulk flow velocities in the solar corona  

Science Journals Connector (OSTI)

......bin. In a small but significant number of images the data are defective, largely owing to telemetry drop outs. These images are easily...velocity-height curves. We perform a five-point running-box-car straight-line fit with appropriate weighting and this rate......

D. J. Lewis; G. M. Simnett

2000-10-01T23:59:59.000Z

113

VELOCITY AND MAGNETIC FIELD DISTRIBUTION IN A FORMING PENUMBRA  

SciTech Connect

We present results from the analysis of high-resolution spectropolarimetric and spectroscopic observations of the solar photosphere and chromosphere, obtained shortly before the formation of a penumbra in one of the leading polarity sunspots of NOAA active region 11490. The observations were performed at the Dunn Solar Telescope of the National Solar Observatory on 2012 May 28, using the Interferometric Bidimensional Spectrometer. The data set is comprised of a 1 hr time sequence of measurements in the Fe I 617.3 nm and Fe I 630.25 nm lines (full Stokes polarimetry) and in the Ca II 854.2 nm line (Stokes I only). We perform an inversion of the Fe I 630.25 nm Stokes profiles to derive magnetic field parameters and the line-of-sight (LOS) velocity at the photospheric level. We characterize chromospheric LOS velocities by the Doppler shift of the centroid of the Ca II 854.2 nm line. We find that, before the formation of the penumbra, an annular zone of 3''-5'' width is visible around the sunspot. In the photosphere, we find that this zone is characterized by an uncombed structure of the magnetic field although no visible penumbra has formed yet. We also find that the chromospheric LOS velocity field shows several elongated structures characterized by downflow and upflow motions in the inner and outer parts of the annular zone, respectively.

Romano, P.; Guglielmino, S. L. [INAF-Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95125 Catania (Italy); Frasca, D.; Zuccarello, F. [Dipartimento di Fisica e Astronomia-Sezione Astrofisica, Universita di Catania, Via S. Sofia 78, I-95125 Catania (Italy); Ermolli, I. [INAF-Osservatorio Astronomico di Roma, Via Frascati 33, I-00040 Monte Porzio Catone (Italy); Tritschler, A.; Reardon, K. P., E-mail: prom@oact.inaf.it [National Solar Observatory/Sacramento Peak, P.O. Box 62, Sunspot, NM 88349-0062 (United States)

2013-07-01T23:59:59.000Z

114

Water Velocity Measurements on a Vertical Barrier Screen at the Bonneville Dam Second Powerhouse  

SciTech Connect

Fish screens at hydroelectric dams help to protect rearing and migrating fish by preventing them from passing through the turbines and directing them towards the bypass channels by providing a sweeping flow parallel to the screen. However, fish screens may actually be harmful to fish if they become impinged on the surface of the screen or become disoriented due to poor flow conditions near the screen. Recent modifications to the vertical barrier screens (VBS) at the Bonneville Dam second powerhouse (B2) intended to increase the guidance of juvenile salmonids into the juvenile bypass system (JBS) have resulted in high mortality and descaling rates of hatchery subyearling Chinook salmon during the 2008 juvenile salmonid passage season. To investigate the potential cause of the high mortality and descaling rates, an in situ water velocity measurement study was conducted using acoustic Doppler velocimeters (ADV) in the gatewell slot at Units 12A and 14A of B2. From the measurements collected the average approach velocity, sweep velocity, and the root mean square (RMS) value of the velocity fluctuations were calculated. The approach velocities measured across the face of the VBS varied but were mostly less than 0.3 m/s. The sweep velocities also showed large variances across the face of the VBS with most measurements being less than 1.5 m/s. This study revealed that the approach velocities exceeded criteria recommended by NOAA Fisheries and Washington State Department of Fish and Wildlife intended to improve fish passage conditions.

Hughes, James S.; Deng, Zhiqun; Weiland, Mark A.; Martinez, Jayson J.; Yuan, Yong

2011-11-22T23:59:59.000Z

115

A MAGNETIC CALIBRATION OF PHOTOSPHERIC DOPPLER VELOCITIES  

SciTech Connect

The zero point of measured photospheric Doppler shifts is uncertain for at least two reasons: instrumental variations (from, e.g., thermal drifts); and the convective blueshift, a known correlation between intensity and upflows. Accurate knowledge of the zero point is, however, useful for (1) improving estimates of the Poynting flux of magnetic energy across the photosphere, and (2) constraining processes underlying flux cancellation, the mutual apparent loss of magnetic flux in closely spaced, opposite-polarity magnetogram features. We present a method to absolutely calibrate line-of-sight (LOS) velocities in solar active regions (ARs) near disk center using three successive vector magnetograms and one Dopplergram coincident with the central magnetogram. It exploits the fact that Doppler shifts measured along polarity inversion lines (PILs) of the LOS magnetic field determine one component of the velocity perpendicular to the magnetic field, and optimizes consistency between changes in LOS flux near PILs and the transport of transverse magnetic flux by LOS velocities, assuming that ideal electric fields govern the magnetic evolution. Previous calibrations fitted the center-to-limb variation of Doppler velocities, but this approach cannot, by itself, account for residual convective shifts at the limb. We apply our method to vector magnetograms of AR 11158, observed by the Helioseismic and Magnetic Imager aboard the Solar Dynamics Observatory, and find clear evidence of offsets in the Doppler zero point in the range of 50-550 m s{sup -1}. In addition, we note that a simpler calibration can be determined from an LOS magnetogram and Dopplergram pair from the median Doppler velocity among all near-disk-center PIL pixels. We briefly discuss shortcomings in our initial implementation, and suggest ways to address these. In addition, as a step in our data reduction, we discuss the use of temporal continuity in the transverse magnetic field direction to correct apparently spurious fluctuations in resolution of the 180 Degree-Sign ambiguity.

Welsch, Brian T.; Fisher, George H. [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States); Sun, Xudong [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States)

2013-03-10T23:59:59.000Z

116

Three-dimensional P and S waves velocity structures of the Coso geothermal  

Open Energy Info (EERE)

P and S waves velocity structures of the Coso geothermal P and S waves velocity structures of the Coso geothermal area, California, from microseismic travel time data Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Three-dimensional P and S waves velocity structures of the Coso geothermal area, California, from microseismic travel time data Details Activities (1) Areas (1) Regions (0) Abstract: High precision P and S wave travel times for 2104 microearthquakes with focus <6 km are used in a non-linear inversion to derive high-resolution three-dimensional compressional and shear velocity structures at the Coso Geothermal Area in eastern California. Block size for the inversion is 0.2 km horizontally and 0.5 km vertically and inversions are investigated in the upper 5 km of the geothermal area.

117

Preliminary Estimates of Specific Discharge and TransportVelocities near Borehole NC-EWDP-24PB  

SciTech Connect

This report summarizes fluid electrical conductivity (FEC)and thermal logging data collected in Borehole NC-EWDP-24PB, locatedapproximately 15 km south of the proposed repository at Yucca Mountain.Preliminary analyses of a small fraction of the FEC and temperature dataindicate that relatively large, localized fluid fluxes are likely toexist at this location. The implication that considerable flow is inducedby small gradients, and that flow is highly localized, is significant forthe estimation of groundwater transport velocities and radionuclidetravel times. The sensitivity of the data to potential perturbationsduring testing (i.e., internal wellbore flow in the case of FEC data, andbuoyancy effects in the case of thermal logging data) make it difficultto conclusively derive fluid fluxes and transport velocities without adetailed analysis of all data and processes involved. Such acomprehensive analysis has not yet been performed. However, thepreliminary results suggest that the ambient component of the estimatedflow rates is significant and on the order of liters per minute, yieldinggroundwater transport velocities in the range of kilometers per year. Oneparticular zone in the Bullfrog tuff exhibits estimated velocities on theorder of 10 km/yr. Given that the preliminary estimates of ambient flowrates and transport velocities are relatively high, and considering thepotential impact of high rates and velocities on saturated-zone flow andtransport behavior, we recommend that a comprehensive analysis of all theavailable data be performed. Moreover, additional data sets at otherlocations should be collected to examine whether the current data set isrepresentative of the regional flow system near YuccaMountain.

Freifeld, Barry; Doughty, Christine; Finsterle, Stefan

2006-06-21T23:59:59.000Z

118

3D REGULARIZED VELOCITY FROM 3D DOPPLER RADIAL VELOCITY X. Chen, J.L. Barron, R.E. Mercer  

E-Print Network (OSTI)

3D REGULARIZED VELOCITY FROM 3D DOPPLER RADIAL VELOCITY X. Chen, J.L. Barron, R.E. Mercer Dept, Ontario, M3H 5T4 Paul.Joe@ec.gc.ca ABSTRACT The recent availability of sequences of 3D Doppler radial velocity datasets provides sufficient information to estimate the 3D velocity of Doppler storms. We present

Barron, John

119

high  

Gasoline and Diesel Fuel Update (EIA)

0 0 Summary Our short-term outlook for a wide array of energy prices has been adjusted upward as international and domestic energy supply conditions have tightened. We think that crude oil prices are as likely as not to end the year $2 to $3 per barrel higher than our previous projections. Thus, we think that the probability of West Texas Intermediate costing an average of $30 per barrel or more at midwinter is about 50 percent. On their current track, heating oil prices are likely to be about 30 percent above year-ago levels in the fourth quarter. Prices for Q1 2001 seem more likely now to match or exceed the high level seen in Q1 2000. Tight oil markets this year and an inherent propensity for high gas utilization in incremental power supply have resulted in rising North American natural gas

120

Frictional behaviour of halite/muscovite fault gouge analogues: Effects of sliding velocity and of stepwise acceleration from sub- to co-seismic slip rates.  

E-Print Network (OSTI)

??Investigating the (transient) frictional behaviour of fault rock from low to high velocities is required in experimental research on the stability of faults and earthquake… (more)

Buijze, A.J.L.

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high velocity sdhv" 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

Laser-driven acceleration of a dense matter up to 'thermonuclear' velocities  

Science Journals Connector (OSTI)

The results of theoretical studies and numerical simulations of laser-driven acceleration of a flat foil up to ultrahigh velocity of the order of 1000?km?s?1, which corresponds to the achievement of thermonuclear temperatures due to kinetic energy transition into thermal energy at an inelastic impact, are reported. The behavior of a foil accelerated to such high velocities, in particular, the distribution of foil density, which defines thermonuclear reaction intensity, has been studied. The calculation results are compared with the results of the experiments performed on the Gekko/HIPER laser, where a laser-driven projectile achieved record-breaking velocity. The laser pulse and foil parameters responsible for acceleration of the projectile up to 'thermonuclear' velocities in a dense state have been determined.

S Yu Gus'kov; H Azechi; N N Demchenko; V V Demchenko; I Ya Doskoch; M Murakami; H Nagatomo; V B Rozanov; S Sakaiya; R V Stepanov; N V Zmitrenko

2007-01-01T23:59:59.000Z

122

high  

Gasoline and Diesel Fuel Update (EIA)

0 0 Highlights International Oil Markets Prices. We have raised our world oil price projection by about $2 per barrel for this month because of assumed greater compliance by OPEC to targeted cuts, especially for the second quarter of 2000 (Figure 1). The expected decline in world petroleum inventories continues (Figure 2), and, given the generally stiff resolve of OPEC members to maintain production cuts, any sign of a turnaround in stocks may be postponed until later this year than previously assumed (Q3 instead of Q2). Our current estimate for the average import cost this past January is now $25 per barrel, a nearly $15-per-barrel increase from January 1999. Crude oil prices are expected to remain at relatively high levels for the first half of 2000, but

123

Residual turbulence from velocity shear stabilized interchange instabilities  

SciTech Connect

The stabilizing effect of velocity shear on the macroscopic, broad bandwidth, ideal interchange instability is studied in linear and nonlinear regimes. A 2D dissipative magnetohydrodynamic (MHD) code is employed to simulate the system. For a given flow shear, V Prime , linear growth rates are shown to be suppressed to below the shear-free level at both the small and large wavelengths. With increasing V Prime , the unstable band in wavenumber-space shrinks so that the peak growth results for modes that correspond to relatively high wavenumbers, on the scale of the density gradient. In the nonlinear turbulent steady state, a similar turbulent spectrum obtains, and the convection cells are roughly circular. In addition, the density fluctuation level and the degree of flattening of the initial inverted density profile are found to decrease as V Prime increases; in fact, unstable modes are almost completely stabilized and the density profile reverts to laminar when V Prime is a few times the classic interchange growth rate. Moreover, the turbulent particle flux diminishes with increasing velocity shear such that all the flux is carried by the classical diffusive flux in the asymptotic limit. The simulations are compared with measurements of magnetic fluctuations from the Maryland Centrifugal Experiment, MCX, which investigated interchange modes in the presence of velocity shear. The experimental spectral data, taken in the plasma edge, are in general agreement with the numerical data obtained in higher viscosity simulations for which the level of viscosity is chosen consistent with MCX Reynolds numbers at the edge. In particular, the residual turbulence in both cases is dominated by elongated convection cells. Finally, concomitant Kelvin-Helmholtz instabilities in the system are also examined. Complete stability to interchanges is obtained only in the parameter space wherein the generalized Rayleigh inflexion theorem is satisfied.

Hung, C. P.; Hassam, A. B. [University of Maryland at College Park, College Park, Maryland 20742 (United States)

2013-01-15T23:59:59.000Z

124

IR diagnostics of embedded jets: velocity resolved observations of the HH34 and HH1 jets  

E-Print Network (OSTI)

We present VLT-ISAAC medium resolution spectroscopy of the HH34 and HH1 jets. Our aim is to derive the kinematics and the physical parameters and to study how they vary with jet velocity. We use several important diagnostic lines such as [FeII] 1.644um, 1.600um and H2 2.122um. In the inner jet region of HH34 we find that both the atomic and molecular gas present two components at high and low velocity. The [FeII] LVC in HH34 is detected up to large distances from the source (>1000 AU), at variance with TTauri jets. In H2 2.122um, the LVC and HVC are spatially separated. We detect, for the first time, the fainter red-shifted counterpart down to the central source. In HH1, we trace the jet down to ~1" from the VLA1 driving source: the kinematics of this inner region is again characterised by the presence of two velocity components, one blue-shifted and one red-shifted with respect to the source LSR velocity. In the inner HH34 jet region, ne increases with decreasing velocity. Up to ~10" from the driving source, and along the whole HH1 jet an opposite behaviour is observed instead, with ne increasing with velocity. In both jets the mass flux is carried mainly by the high-velocity gas. A comparison between the position velocity diagrams and derived electron densities with models for MHD jet launching mechanisms has been performed for HH34. While the kinematical characteristics of the line emission at the jet base can be, at least qualitatively, reproduced by both X-winds and disc-wind models, none of these models can explain the extent of the LVC and the dependence of electron density with velocity that we observe. It is possible that the LVC in HH34 represents gas not directly ejected in the jet but instead denser ambient gas entrained by the high velocity collimated jet.

R. Garcia Lopez; B. Nisini; T. Giannini; J. Eisloeffel; F. Bacciotti; L. Podio

2008-05-19T23:59:59.000Z

125

On Approximating the Translational Velocity of Vortex Rings  

E-Print Network (OSTI)

from this configuration and the system scaling. Here, the accuracy of this approximation is presented orifice in a flat plate contain a converging radial component of velocity. For both configurations. By this definition, the piston velocity is the average jet velocity passing through the orifice independent

Mohseni, Kamran

126

LAMINAR BURNING VELOCITY OF GASOLINES WITH ADDITION OF ETHANOL  

E-Print Network (OSTI)

1 LAMINAR BURNING VELOCITY OF GASOLINES WITH ADDITION OF ETHANOL P. Dirrenberger1 , P.A. Glaude*1 (2014) 162-169" DOI : 10.1016/j.fuel.2013.07.015 #12;2 LAMINAR BURNING VELOCITY OF GASOLINES, Sweden Abstract The adiabatic laminar burning velocities of a commercial gasoline and of a model fuel (n

Boyer, Edmond

127

Observations of Velocity Conditions near a Hydroelectric Turbine Draft Tube Exit using ADCP Measurements  

SciTech Connect

Measurement of flow characteristics near hydraulic structures is an ongoing challenge because of the need to obtain rapid measurements of time-varying velocity over a relatively large spatial domain. This paper discusses use of an acoustic Doppler current profiler (ADCP) to measure the rapidly diverging flow exiting from an operating hydroelectric turbine draft tube exit. The resolved three-dimensional velocity vectors show a highly complex and helical flow pattern developed near to and downstream of the exit. Velocity vectors were integrated across the exit and we computed an uneven percentage of flow (67%/33%) passing through the two draft tube barrels at a mid-range turbine discharge, consistent with physical model results. In addition to the three-dimensional velocity vectors, the individual one-dimensional velocities measured by each of the four ADCP beams can be separately used as calibration and validation datasets for numerical and physical models. This technique is demonstrated by comparing along-beam ADCP velocity measurements to data collected in a scaled physical model.

Cook, Christopher B.; Richmond, Marshall C.; Serkowski, John A.

2007-10-01T23:59:59.000Z

128

Relative velocity of dark matter and baryons in clusters of galaxies and measurements of their peculiar velocities  

Science Journals Connector (OSTI)

......Salpeter initial mass function...fixed to get a wind velocity of 1. More...Synthetic maps of observables...call peculiar velocity the mean (and mass-weighted...maximum circular velocity (e.g. mass) of galaxies...kinetic SZ map directly produced......

K. Dolag; R. Sunyaev

2013-01-01T23:59:59.000Z

129

Filament velocity scaling laws for warm ions  

SciTech Connect

The dynamics of filaments or blobs in the scrape-off layer of magnetic fusion devices are studied by magnitude estimates of a comprehensive drift-interchange-Alfvén fluid model. The standard blob models are reproduced in the cold ion case. Even though usually neglected, in the scrape-off layer, the ion temperature can exceed the electron temperature by an order of magnitude. The ion pressure affects the dynamics of filaments amongst others by adding up to the interchange drive and the polarisation current. It is shown how both effects modify the scaling laws for filament velocity in dependence of its size. Simplifications for experimentally relevant limit regimes are given. These are the sheath dissipation, collisional, and electromagnetic regime.

Manz, P. [Physik-Department E28, Technische Universität München, James-Franck-Str. 1, 85748 Garching (Germany) [Physik-Department E28, Technische Universität München, James-Franck-Str. 1, 85748 Garching (Germany); Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany); Carralero, D.; Birkenmeier, G.; Müller, H. W.; Scott, B. D. [Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany)] [Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany); Müller, S. H. [Center for Momentum Transport and Flow Organization, University of California at San Diego, San Diego 92093 (United States)] [Center for Momentum Transport and Flow Organization, University of California at San Diego, San Diego 92093 (United States); Fuchert, G. [Insitut für Grenzflächenverfahrenstechnik und Plasmatechnologie, Universität Stuttgart, 70569 Stuttgart (Germany)] [Insitut für Grenzflächenverfahrenstechnik und Plasmatechnologie, Universität Stuttgart, 70569 Stuttgart (Germany); Stroth, U. [Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany) [Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany); Physik-Department E28, Technische Universität München, James-Franck-Str. 1, 85748 Garching (Germany)

2013-10-15T23:59:59.000Z

130

Single-mode fiber, velocity interferometry  

SciTech Connect

In this paper, we describe a velocity interferometer system based entirely on single-mode fiber optics. This paper includes a description of principles used in developing the single-mode velocity interferometry system (SMV). The SMV design is based on polarization-insensitive components. Polarization adjusters are included to eliminate the effects of residual birefringence and polarization dependent losses in the interferometers. Characterization measurements and calibration methods needed for data analysis and a method of data analysis are described. Calibration is performed directly using tunable lasers. During development, we demonstrated its operation using exploding-foil bridge-wire fliers up to 200 m/s. In a final test, we demonstrated the SMV in a gas gun experiment up to 1.2 km/sec. As a basis for comparison in the gas gun experiment, we used another velocimetry technique that is also based on single-mode fiber optics: photonic Doppler velocimetry (PDV). For the gas gun experiment, we split the light returned from a single target spot and performed a direct comparison of the homodyne (SMV) and heterodyne (PDV) techniques concurrently. The two techniques had a negligible mean difference and a 1.5% standard deviation in the one-dimensional shock zone. Within one interferometer delay time after a sudden Doppler shift, a SMV unencumbered by multimode-fiber dispersion exhibits two color beats. These beats have the same period as PDV beats--this interference occurs between the ''recently'' shifted and ''formerly unshifted'' paths within the interferometer. We believe that recognizing this identity between homodyne and heterodyne beats is novel in the shock-physics field. SMV includes the conveniences of optical fiber, while removing the time resolution limitations associated with the multimode delivery fiber.

Krauter, K. G.; Jacobson, G. F.; Patterson, J. R.; Nguyen, J. H.; Ambrose, W. P. [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore California 94551 (United States)

2011-04-15T23:59:59.000Z

131

Time-synchronized continuous wave laser-induced fluorescence axial velocity measurements in a diverging cusped field thruster  

Science Journals Connector (OSTI)

Measurements are presented of time-synchronized axial ion velocities at three positions in the discharge channel and plume of a diverging cusped field thruster operating on xenon. Xenon axial ion velocities for the thruster are derived from laser-induced fluorescence measurements of the 5d[4]7/2–6p[3]5/2 xenon ion excited state transition centred at ? = 834.72 nm. The thruster is operated in a high-current mode, where the anode discharge current is shown to oscillate quasi-periodically. A sample-hold scheme is implemented to correlate ion velocities to phases along the current cycle. These time-synchronized measurements show that median axial ion velocities decrease as discharge current increases, and that the widths of ion velocity distributions increase with increases in discharge current for positions at the exit plane and outside the thruster channel.

N A MacDonald; M A Cappelli; W A Hargus Jr

2014-01-01T23:59:59.000Z

132

Refinement in the ultrasonic velocity data and estimation of the critical parameters for molten uranium dioxide  

E-Print Network (OSTI)

the reactor and its vicinity. A reliable equation of state for the nuclear fuel, therefore, necessitates, reliable data on the sound prop- agation velocity in molten uranium dioxide have been obtained. An equation reserved. 1. Introduction The analysis of hypothetical and undesirable yet highly improbable accidents

Azad, Abdul-Majeed

133

Nanogenerator as an active sensor for vortex capture and ambient wind-velocity detection  

E-Print Network (OSTI)

and mechanical (wind, water flow, vibration, friction and body movement) energies are common in the ambientNanogenerator as an active sensor for vortex capture and ambient wind-velocity detection Rui Zhang principle, ambient wind-speed measurements with the NG are demonstrated. Due to the simple structure, high

Wang, Zhong L.

134

Coherence, Strain, and Phase Velocity of Strong Ground Motions in the Mississippi Charles A. Langston  

E-Print Network (OSTI)

ground motions in the deep, unconsolidated Mississippi embayment sediments since there are no comparable within the thick, unconsolidated sedimentary column, the high velocity basement rocks, and small is the existence of thick, unconsolidated sediments that blanket the area and attain thicknesses of up to kilometer

Langston, Charles A.

135

Radial velocity measurements of white dwarfs  

E-Print Network (OSTI)

We present 594 radial velocity measurements for 71 white dwarfs obtained during our search for binary white dwarfs and not reported elsewhere. We identify three excellent candidate binaries, which require further observations to confirm our preliminary estimates for their orbital periods, and one other good candidate. We investigate whether our data support the existence of a population of single, low mass (<~0.5 solar masses) white dwarfs (LMWDs). These stars are difficult to explain in standard models of stellar evolution. We find that a model with a mixed single/binary population is at least ~20 times more likely to explain our data than a pure binary population. This result depends on assumed period distributions for binary LMWDs, assumed companion masses and several other factors. Therefore, the evidence in favour of the existence of a population of single LMWDs is not sufficient, in our opinion, to firmly establish the existence of such a population, but does suggest that extended observations of LMWDs to obtain a more convincing result would be worthwhile .

P. F. L. Maxted; T. R. Marsh; C. K. J. Moran

2000-07-11T23:59:59.000Z

136

True Masses of Radial-Velocity Exoplanets  

E-Print Network (OSTI)

We explore the science power of space telescopes used to estimate the true masses of known radial-velocity exoplanets by means of astrometry on direct images. We translate a desired mass accuracy (+/10% in our example) into a minimum goal for the signal-to-noise ratio, which implies a minimum exposure time. When the planet is near a node, the mass measurement becomes difficult if not impossible, because the apparent separation becomes decoupled from the inclination angle of the orbit. The combination of this nodal effect with considerations of solar and anti-solar pointing restrictions, photometric and obscurational completeness, and image blurring due to orbital motion, severely limits the observing opportunities, often to only brief intervals in a five-year mission. We compare the science power of four missions, two with external star shades, EXO-S and WFIRST-S, and two with internal coronagraphs, EXO-C and WFIRST-C. The star shades out-perform the coronagraph in this science program by about a factor of th...

Brown, Robert A

2015-01-01T23:59:59.000Z

137

Shake Table for Calibration of Velocity Pickups  

Science Journals Connector (OSTI)

A Shake Table was developed and built by the Engineering Research Institute to calibrate low?frequency (0 to 200 cps) velocity pickups. The platform that supports the pickup to be tested is 6 in. in diameter and will support a load of approximately 30 lb. This makes the use of a table limited by force it can deliver except at very low frequencies. The table will operate with a 10 lb load to a frequency of 150 cps. The platform displacement is 0.125 in. peak?to?peak. The platform and its load are supported by air bellows. This is an improvement over a spring support due to the fact that it has greater damping and it is more easily adjusted to different loads. The adjustment consists of just putting more air in the bellows. The table is driven by a dc push?pull power amplifier. This delivers a current to a tapped coil on the Shake Table that is located in a magnetic field. The field is set up by a coil energized by 24 volts. The power amplifier can be driven by any convenient source delivering about 1 volt. (Parts of this research were supported by Tri?service Contract No. DA?36?039?sc?52654.)

J. W. Wescott; J. H. Prout; W. H. Follett

1957-01-01T23:59:59.000Z

138

Natural discharge after pulse and cooperative electrodes to enhance droplet velocity in digital microfluidics  

SciTech Connect

Digital Microfluidics (DMF) is a promising technology for biological/chemical micro-reactions due to its distinct droplet manageability via electronic automation, but the limited velocity of droplet transportation has hindered DMF from utilization in high throughput applications. In this paper, by adaptively fitting the actuation voltages to the dynamic motions of droplet movement under real-time feedback monitoring, two control-engaged electrode-driving techniques: Natural Discharge after Pulse (NDAP) and Cooperative Electrodes (CE) are proposed. They together lead to, for the first time, enhanced droplet velocity with lower root mean square voltage value.

Chen, Tianlan; Dong, Cheng; Gao, Jie; Jia, Yanwei; Mak, Pui-In, E-mail: pimak@umac.mo; Vai, Mang-I; Martins, Rui P. [State Key Laboratory of Analog and Mixed-Signal VLSI and FST-ECE, University of Macau, Macao (China)] [State Key Laboratory of Analog and Mixed-Signal VLSI and FST-ECE, University of Macau, Macao (China)

2014-04-15T23:59:59.000Z

139

Two-dimensional Imaging Velocity Interferometry: Technique and Data Analysis  

SciTech Connect

We describe the data analysis procedures for an emerging interferometric technique for measuring motion across a two-dimensional image at a moment in time, i.e. a snapshot 2d-VISAR. Velocity interferometers (VISAR) measuring target motion to high precision have been an important diagnostic in shockwave physics for many years Until recently, this diagnostic has been limited to measuring motion at points or lines across a target. We introduce an emerging interferometric technique for measuring motion across a two-dimensional image, which could be called a snapshot 2d-VISAR. If a sufficiently fast movie camera technology existed, it could be placed behind a traditional VISAR optical system and record a 2d image vs time. But since that technology is not yet available, we use a CCD detector to record a single 2d image, with the pulsed nature of the illumination providing the time resolution. Consequently, since we are using pulsed illumination having a coherence length shorter than the VISAR interferometer delay ({approx}0.1 ns), we must use the white light velocimetry configuration to produce fringes with significant visibility. In this scheme, two interferometers (illuminating, detecting) having nearly identical delays are used in series, with one before the target and one after. This produces fringes with at most 50% visibility, but otherwise has the same fringe shift per target motion of a traditional VISAR. The 2d-VISAR observes a new world of information about shock behavior not readily accessible by traditional point or 1d-VISARS, simultaneously providing both a velocity map and an 'ordinary' snapshot photograph of the target. The 2d-VISAR has been used to observe nonuniformities in NIF related targets (polycrystalline diamond, Be), and in Si and Al.

Erskine, D J; Smith, R F; Bolme, C; Celliers, P; Collins, G

2011-03-23T23:59:59.000Z

140

Waveinduced velocities inside a model seagrass bed Mitul Luhar,1  

E-Print Network (OSTI)

. By damping nearbed water velocities, seagrasses reduce local resuspension and promote the retention the seabed. Reduced resuspension improves water clarity, leading to greater light penetration and increased

Nepf, Heidi M.

Note: This page contains sample records for the topic "high velocity sdhv" 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

Pseudostress-velocity formulation for incompressible Navier-Stokes ...  

E-Print Network (OSTI)

Velocity profiles and streamline portraits for Re=100 with h = 1. 128 and different . Circles in ... of meshes generated by a refining process. The error between ...

2009-05-29T23:59:59.000Z

142

Crusius, John, and Rik Wanninkhof, Gas transfer velocities ...  

Science Journals Connector (OSTI)

Jun 29, 2000 ... 2003, by the American Society of Limnology and Oceanography, Inc. Gas transfer velocities measured at low wind speed over a lake.

2003-05-02T23:59:59.000Z

143

Multipole-specific, model-independent, velocity-change spectra of collisionally perturbed P13-state Yb174 atoms  

Science Journals Connector (OSTI)

Coherent transient (echo) techniques have been employed in a high-precision study of collisional velocity thermalization in a sample of (6s6p)P13, excited-state, Yb174 atoms perturbed by He or Ar. This work probes the comparative response of aligned and oriented atoms to both depolarizing and to weak, nondepolarizing and/or velocity-changing collisions. By direct inversion of our time-domain echo relaxation data, we also provide a model-independent determination of velocity-change spectra (collision kernels) for nondepolarizing collisions.

A. G. Yodh; T. W. Mossberg; J. E. Thomas

1986-12-01T23:59:59.000Z

144

High-Current Accelerators  

E-Print Network (OSTI)

F i g . 13 F i g . 14 A 48 ACCELERATOR F i g . 25 F i g . 16supply. Extrapolation of accelerator energy and current9 . A-48 high-current accelerator, low-velocity end. Fig.

Lawrence, Ernest O.

1955-01-01T23:59:59.000Z

145

Free–energy landscape and the critical velocity of superfluid films  

Science Journals Connector (OSTI)

...P. Boon and P. V. Coveney Free-energy landscape and the critical velocity...superfluids shedding light on the free-energy landscape, the critical velocity...critical velocity|vortex| Free-energy landscape and the critical velocity...

2004-01-01T23:59:59.000Z

146

Velocity of Second Sound in NaF  

Science Journals Connector (OSTI)

The velocity of drifting second sound and the heat capacity per unit volume are calculated for NaF for temperatures from 0 to 40 °K. The velocity of second sound decreases by 24% as the temperature is increased from 10 to 30 °K, because of the dispersion of the phonon frequency spectrum.

Robert J. Hardy and S. S. Jaswal

1971-06-15T23:59:59.000Z

147

Hydrocarbon saturation determination using acoustic velocities obtained through casing  

DOE Patents (OSTI)

Compressional and shear velocities of earth formations are measured through casing. The determined compressional and shear velocities are used in a two component mixing model to provides improved quantitative values for the solid, the dry frame, and the pore compressibility. These are used in determination of hydrocarbon saturation.

Moos, Daniel (Houston, TX)

2010-03-09T23:59:59.000Z

148

Comparing Glider Observed Velocities and Geostrophic Currents Regina Yopak  

E-Print Network (OSTI)

offshore and brings cold, deep water to fill it's place. The upwelling regime creates a unique coastal. This project endeavors to compare calculated geostrophic velocities to the water velocities measured which the net vertical volume of water is transferred 90° to the right which forces warm, surface waters

Kurapov, Alexander

149

On the Structure of the Low Velocity Zone  

Science Journals Connector (OSTI)

......large nuclear explosions at the Nevada Test Site have been used to model the P-velocity...1961. Crustal structure from Nevada Test Site to Kingman, Arizona from seismic...large nuclear explosions at the Nevada Test Site have been used to model the P-velocity......

Donald V. Helmberger

1973-11-01T23:59:59.000Z

150

Tsallis Entropy Based Velocity Distribution in Open Channel Flows  

E-Print Network (OSTI)

............................................................. 94 32 Dimensionless velocity distribution and parameter M ............................... 96 33 um/ umax versus various M ........................................................................... 99 34 Upper Tiber River basin with location... velocity distribution with different m ... 68 9 Computation of M, ?1 and ?V based on um and umax measured on the Po river (Italy) for different verticals at Pontelagoscuro gauged section during flood event that occurred on February 2, 1985...

Luo, Hao

2010-07-14T23:59:59.000Z

151

Tracking moving radar targets with parallel, velocity-tuned filters  

DOE Patents (OSTI)

Radar data associated with radar illumination of a movable target is processed to monitor motion of the target. A plurality of filter operations are performed in parallel on the radar data so that each filter operation produces target image information. The filter operations are defined to have respectively corresponding velocity ranges that differ from one another. The target image information produced by one of the filter operations represents the target more accurately than the target image information produced by the remainder of the filter operations when a current velocity of the target is within the velocity range associated with the one filter operation. In response to the current velocity of the target being within the velocity range associated with the one filter operation, motion of the target is tracked based on the target image information produced by the one filter operation.

Bickel, Douglas L.; Harmony, David W.; Bielek, Timothy P.; Hollowell, Jeff A.; Murray, Margaret S.; Martinez, Ana

2013-04-30T23:59:59.000Z

152

Discrimination of porosity and fluid saturation using seismic velocity analysis  

DOE Patents (OSTI)

The method of the invention is employed for determining the state of saturation in a subterranean formation using only seismic velocity measurements (e.g., shear and compressional wave velocity data). Seismic velocity data collected from a region of the formation of like solid material properties can provide relatively accurate partial saturation data derived from a well-defined triangle plotted in a (.rho./.mu., .lambda./.mu.)-plane. When the seismic velocity data are collected over a large region of a formation having both like and unlike materials, the method first distinguishes the like materials by initially plotting the seismic velocity data in a (.rho./.lambda., .mu./.lambda.)-plane to determine regions of the formation having like solid material properties and porosity.

Berryman, James G. (Danville, CA)

2001-01-01T23:59:59.000Z

153

Detection of electron velocity in graphene by Doppler effect  

Science Journals Connector (OSTI)

Abstract Electron velocity in a two-dimensional electron gas can be measured by Doppler shift. Thus, we construct the Doppler shift of light and apply it to the motion of electrons in a graphene sheet to estimate the electron velocity. Here, a laser beam with initial frequency is incident on the graphene sheet in a parallel direction, and then the frequency of the emitted light can be measured by spectroscopy after detecting the electron velocity. Then, the ratio of frequency shift from the Doppler effect is described in terms of the electron velocity, as well as the incident and the detection angle of laser beam. The thermal broadening of detected frequency as a function of velocity is also shown for different temperatures.

Heetae Kim; Chang-Soo Park; Hak Dong Cho

2014-01-01T23:59:59.000Z

154

Precision Measuring of Velocities via the Relativistic Doppler Effect  

E-Print Network (OSTI)

Just as the ordinary Doppler effect serves as a tool to measure radial velocities of celestial objects, so can the relativistic Doppler effect be implemented to measure a combination of radial and transverse velocities by using recent improvements in observing techniques. A key element that makes a further use of this combination feasible is the periodicity in changes of the orbital velocity direction for the source. Two cases are considered: (i) a binary star; and (ii) a solitary star with the planetary companion. It is shown that, in case (i), several precision Doppler measurements employing the gas absorption cell technique would determine both the total orbital velocity and the inclination angle of the binary orbit disentangled from the peculiar velocity of the system. The necessary condition for that is the measured, at least with a modest precision, proper motion and distance to the system.

Leonid M. Ozernoy

1997-12-26T23:59:59.000Z

155

Inversion of azimuthally dependent NMO velocity in transversely isotropic media with a tilted axis of symmetry  

SciTech Connect

Just as the transversely isotropic model with a vertical symmetry axis (VTI media) is typical for describing horizontally layered sediments, transverse isotropy with a tilted symmetry axis (TTI) describes dipping TI layers (such as tilted shale beds near salt domes) or crack systems. P-wave kinematic signatures in TTI media are controlled by the velocity V{sub PO} in the symmetry direction, Thomsen's anisotropic coefficients {xi} and {delta}, and the orientation (tilt {nu} and azimuth {beta}) of the symmetry axis. Here, the authors show that all five parameters can be obtained from azimuthally varying P-wave NMO velocities measured for two reflectors with different dips and/or azimuths (one of the reflectors can be horizontal). The shear-wave velocity V{sub SO} in the symmetry direction, which has negligible influence on P-wave kinematic signatures, can be found only from the moveout of shear waves. Using the exact NMO equation, the authors examine the propagation of errors in observed moveout velocities into estimated values of the anisotropic parameters and establish the necessary conditions for a stable inversion procedure. Since the azimuthal variation of the NMO velocity is elliptical, each reflection event provides them with up to three constraints on the model parameters. Generally, the five parameters responsible for P-wave velocity can be obtained from two P-wave ellipses, but the feasibility of the moveout inversion strongly depends on the tilt {nu}. While most of the analysis is carried out for a single layer, the authors also extend the inversion algorithm to vertically heterogeneous TTI media above a dipping reflector using the generalized Dix equation. A synthetic example for a strongly anisotropic, stratified TTI medium demonstrates a high accuracy of the inversion.

Grechka, V.; Tsvankin, I.

2000-02-01T23:59:59.000Z

156

Ultrasonic velocity measurements for synthetic gas?hydrate samples  

Science Journals Connector (OSTI)

Laboratory ultrasonic methods offer a way of studying acoustic velocity of a gas?hydrate bearing formation. By measuringultrasonic velocities of the gas?hydrate samples in various temperature and pressure conditions more effective inversion techniques can be developed to quantitatively evaluate gas?hydrate concentration and distributions. Low?temperature laboratory measurements of compressional velocities in compacted samples are conducted. These gas?hydrate samples are synthesized by using various densities at various pressures and temperatures. At ?10°C the compressional velocities of the compacted gas?hydrate samples are from 2440 to 3570 m/s with the density range from 475 to 898 kg/m3. Compressional velocity measurements are made where the temperature and pressure can be controlled. When the pore pressure increases from 10 to 40 MPa the compressional velocities of the sample increases from 2340 to 2600 m/s at 1.5°C. When the temperature decreases from 10° to ?13°C the compressional velocity will increase from 3600 to 3800 m/s at a pore pressure of 6 MPa. Our experimental results are qualitatively in agreement with those of weighted average model and the Biot?Gassmanns model when the gas?hydrate concentration in a sediment bearing sand is about 20%. [Work supported by National Natural Science Fundation of China No. 10534040.

2006-01-01T23:59:59.000Z

157

Two-stream instability with time-dependent drift velocity  

The classical two-stream instability driven by a constant relative drift velocity between two plasma components is extended to the case with time-dependent drift velocity. A solution method is developed to rigorously define and calculate the instability growth rate for linear perturbations relative to the time-dependent unperturbed two-stream motions. Stability diagrams for the oscillating two-stream instability are presented over a large region of parameter space. It is shown that the growth rate for the classical two-stream instability can be significantly reduced by adding an oscillatory component to the relative drift velocity.

Qin, Hong [PPPL; Davidson, Ronald C. [PPPL

2014-01-01T23:59:59.000Z

158

Seismic Velocity And Attenuation Structure Of The Geysers Geothermal Field,  

Open Energy Info (EERE)

Velocity And Attenuation Structure Of The Geysers Geothermal Field, Velocity And Attenuation Structure Of The Geysers Geothermal Field, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Seismic Velocity And Attenuation Structure Of The Geysers Geothermal Field, California Details Activities (1) Areas (1) Regions (0) Abstract: The Geysers geothermal field is located in northern California and is one of the world's largest producers of electricity from geothermal energy. A key resource management issue at this field is the distribution of fluid in the matrix of the reservoir rock. In this paper, we interpret seismic compressional-wave velocity and quality quotient (Q) data at The Geysers in terms of the geologic structure and fluid saturation in the reservoir. Our data consist of waveforms from approximately 300

159

Y-12 Site Experience with Deposition Velocity Issues  

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

Site Experience with Site Experience with Deposition Velocity Issues Douglas Clark Analyst B&W Technical Services Y-12 May 9, 2012 Y-12 Site Experience with Deposition Velocity Issues Y-12 Specific Issues Y-12 Site Experience with Deposition Velocity Issues Windspeed - Calm Wind Conditions at Y-12 Site Y-12 Site Experience with Deposition Velocity Issues Windspeed - Stability Class Determinations * NRC RG 1.23 ΔT-only method * EPA-454/R-99-005 solar- radiation-delta-temperature (SRDT) method * Hybrid SR - DT method * wind direction standard deviation [sigma-theta (σ θ )] * elevation angle standard deviation [sigma-phi (σ φ )] * vertical wind speed standard deviation [sigma-omega (σ ω )], * wind-speed ratio method (u R ) * All evaluated using data from west

160

Elastic constants and velocity surfaces of indurated anisotropic shales  

Science Journals Connector (OSTI)

The velocities of two Devonian-Mississippian shales have been measured to confining pressures of 200 MPa in a laboratory study of anisotropy and wave propagation. Both samples were found to be transversely iso...

Joel E. Johnston; Nikolas I. Christensen

1994-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "high velocity sdhv" 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

Detonation velocity deficit and curvature radius of flexible detonation fuses  

Science Journals Connector (OSTI)

The detonation velocity deficit in bending flexible detonating fuses is studied, based on the detonation wave’s corner effects and delay time ... model and a theoretical mathematical equation of the detonation ve...

Y. -Q. Wen; Ya. -K. Ye; N. Yan

2012-03-01T23:59:59.000Z

162

Effect of Adhesive Tape on the Velocity Profile of Water  

Science Journals Connector (OSTI)

... fully developed turbulent flow in order to discover the effect on the velocity profile of roughening the channel bed by sticking sand grains of various known dimensions to it by means ...

ALAN E. COSSAR

1970-09-05T23:59:59.000Z

163

Velocity of sound in solid methane near melting temperatures  

E-Print Network (OSTI)

VELOCITY OF SOUND IN SOLID METHANE NEAR MELTING TEMPERATURES A Thesis By JOHN MARTIN WHITEHEAD Submitted to the Graduate College of the Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May... 1968 Ma)or Sub)ect: Physics VELOCITY OF SOVND IN SOLID METHANE NEAR MELTING TEMPERATURES A Thesis By JOHN MARTIN WHITEHEAD Approved as to style and content by& (Chairman of Committee) (Head of Departsmnt) (Mem er (Member) May 1968...

Whitehead, John Martin

2012-06-07T23:59:59.000Z

164

Temperature and velocity effects in naphthenic acid corrosion  

SciTech Connect

The effects of temperature and velocity were studied with respect to alloy selection for corrosion resistant service. The amount of molybdenum in the austenitic stainless steel alloys is critical in conferring corrosion resistance on the alloy as the temperature of the environment increases. Velocity effects have been studied in a closed loop hot oil circuit where the stream impinges on the target specimen. Film breakdown is prevented by increasing the molybdenum content.

Craig, H.L. Jr. [Corrosion Prevention and Control, Richmond, VA (United States)

1996-08-01T23:59:59.000Z

165

Spatiotemporal Signal Analysis via the Phase Velocity Transform  

Science Journals Connector (OSTI)

The phase velocity transform (PVT) is an integral transform that divides a function of space and time into components that propagate at uniform phase velocities without distortion. This paper examines the PVT as a method to analyze spatiotemporal fluctuation data. The transform is extended to systems with discretely sampled data on a periodic domain, and applied to data from eight azimuthally distributed probes on the Sustained Spheromak Physics Experiment (SSPX). This reveals features not shown by Fourier analysis, particularly regarding nonsinusoidal mode structure.

Nathan Mattor

2000-06-26T23:59:59.000Z

166

Vertical velocity in oceanic convection off tropical Australia  

E-Print Network (OSTI)

. . . . . . . v Vl Vl I I 1 3 6 10 Description of the Data Data Processing . . Event Criteria 10 15 21 III RESULTS . . . 26 Cores. Environment 26 34 IV COMPARISON WITH OTHER STUDIES . . . . . 40 Cores... Variations with altitude of median and strongest 10'/o-level statistics of (a) average vertical velocity, (b) maximum vertical velocity, (c) mass flux per unit length normal to the flight track and (d) diameter 32 Figure Page Reconstructed temperature...

Lucas, Christopher

2012-06-07T23:59:59.000Z

167

Interrelationships between air velocity and globe thermometer response  

E-Print Network (OSTI)

INTERRELATIONSHIPS BE~ AIR VELOCITY ANIl GLOBE THERMOMETER RESPONSE A Thesis JANES ROBERT THORNTON Submitted to the Graduate College of Texas ARAN University in partial fulfillment of the requirement for the degree of NASTER OF SCIENCE... August 197$ Najor Subject: Industrial Hygiene INTERRELATIONSHIPS BETWEEZ AIR VELOCITY AND GLOBE THERMOMETER RESPONSE A Thesis JAMES ROBERT THORNTON Approved as to style and content by: h z. an o ommmt ee ad o partmen Me er August 1$7$ ABSTRACT...

Thornton, James Robert

1973-01-01T23:59:59.000Z

168

Laser-induced fluorescence velocity measurements of a diverging cusped-field thruster  

Science Journals Connector (OSTI)

Measurements are presented of the most probable time-averaged ion velocities within the acceleration channel and in the plume of a diverging cusped-field thruster operating on xenon. Xenon ion velocities for the thruster are derived from laser-induced fluorescence measurements of the 5d[4]7/2–6p[3]5/2 xenon ion excited state transition centred at ? = 834.72?nm. The thruster is operated in both a high-current mode, where the anode discharge current is shown to oscillate periodically, and a low-current mode where operation is relatively quiescent. In the low-current mode, ion emission is predominantly in the form of a conical jet, whereas in the high-current mode, the emission is still divergent but more diffuse throughout the cone angle. These time-average measurements provide insight into the structure of the acceleration region. However, discerning the mechanism for the diffuse ion emission in the strongly oscillating high-current mode will require ion velocity measurements capable of resolving the time-dependent behaviour of the discharge.

N A MacDonald; M A Cappelli; S R Gildea; M Martínez-Sánchez; W A Hargus Jr

2011-01-01T23:59:59.000Z

169

Exceptional Ground Accelerations and Velocities Caused by Earthquakes  

SciTech Connect

This project aims to understand the characteristics of the free-field strong-motion records that have yielded the 100 largest peak accelerations and the 100 largest peak velocities recorded to date. The peak is defined as the maximum magnitude of the acceleration or velocity vector during the strong shaking. This compilation includes 35 records with peak acceleration greater than gravity, and 41 records with peak velocities greater than 100 cm/s. The results represent an estimated 150,000 instrument-years of strong-motion recordings. The mean horizontal acceleration or velocity, as used for the NGA ground motion models, is typically 0.76 times the magnitude of this vector peak. Accelerations in the top 100 come from earthquakes as small as magnitude 5, while velocities in the top 100 all come from earthquakes with magnitude 6 or larger. Records are dominated by crustal earthquakes with thrust, oblique-thrust, or strike-slip mechanisms. Normal faulting mechanisms in crustal earthquakes constitute under 5% of the records in the databases searched, and an even smaller percentage of the exceptional records. All NEHRP site categories have contributed exceptional records, in proportions similar to the extent that they are represented in the larger database.

Anderson, John

2008-01-17T23:59:59.000Z

170

Smart panels with SISO or MIMO velocity feedback control systems  

Science Journals Connector (OSTI)

This paper summarizes and contrasts the research work that has been carried out on two types of smart panels with ASAC control systems: first a SISO velocity feedback control system with a sensor that detects the volumetric component of the vibration of the panel and an actuator that exerts a uniform force over the surface of the panel and second a MIMO decentralized feedback control system using a grid of sensors that measure the point velocities of the panel and a grid of actuators that generates point excitations in the locations of the sensors. Both theoretical predictions and experimental results are presented for a reference problem of control of sound radiation by a rectangular panel clamped along the perimeter. The simulations carried out for the two systems have shown that the smart panel with the volume velocity sensor and uniform force actuator can in principle give better control performance than the smart panel with the sixteen decentralized control units. However the practical implementation of the smart panel with the volume velocity sensor and uniform force actuator is limited by stability problems which are instead a minor issue for the panel with 16 decentralized velocity feedback control units.

2003-01-01T23:59:59.000Z

171

VELOCITY ANISOTROPY AND SHAPE BIAS IN THE CAUSTIC TECHNIQUE  

SciTech Connect

We use the Millennium Simulation to quantify the statistical accuracy and precision of the escape-velocity technique for measuring cluster-sized halo masses at z {approx} 0.1. We show that in three dimensions one can measure nearly unbiased (<4%) halo masses (>1.5 Multiplication-Sign 10{sup 14} M{sub Sun} h {sup -1}) with 10%-15% scatter. Line-of-sight projection effects increase the scatter to {approx}25%, where we include the known velocity anisotropies. The classical ''caustic'' technique incorporates a calibration factor that is determined from N-body simulations. We derive and test a new implementation that eliminates the need for calibration and utilizes only the observables: the galaxy velocities with respect to the cluster mean v, the projected positions r{sub p} , an estimate of the Navarro-Frenk-White (NFW) density concentration, and an estimate of the velocity anisotropies {beta}. We find that differences between the potential and density NFW concentrations induce a 10% bias in the caustic masses. We also find that large (100%) systematic errors in the observed ensemble average velocity anisotropies and concentrations translate to small (5%-10%) biases in the inferred masses.

Gifford, Daniel; Miller, Christopher J. [Department of Astronomy, University of Michigan, 500 Church St., Ann Arbor, MI 48109 (United States)

2013-05-10T23:59:59.000Z

172

Why should we correct reported pulsation frequencies for stellar line-of-sight Doppler velocity shifts?  

E-Print Network (OSTI)

In the age of Kepler and Corot, extended observations have provided estimates of stellar pulsation frequencies that have achieved new levels of precision, regularly exceeding fractional levels of a few parts in $10^{4}$. These high levels of precision now in principle exceed the point where one can ignore the Doppler shift of pulsation frequencies caused by the motion of a star relative to the observer. We present a correction for these Doppler shifts and use previously published pulsation frequencies to demonstrate the significance of the effect. We suggest that reported pulsation frequencies should be routinely corrected for stellar line-of-sight velocity Doppler shifts, or if a line-of-sight velocity estimate is not available, the frame of reference in which the frequencies are reported should be clearly stated.

Davies, G R; Miglio, A; Campante, T L; Chaplin, W J; Elsworth, Y

2014-01-01T23:59:59.000Z

173

Impacts of Raindrop Fall Velocity and Axis Ratio Errors on Dual-Polarization Radar Rainfall Estimation  

Science Journals Connector (OSTI)

Motivated by the field observations of fall velocity and axis ratio deviations from predicted terminal velocity and equilibrium axis ratio values, the combined effects of raindrop fall velocity and axis ratio deviations on dual-polarization radar ...

Bin Pei; Firat Y. Testik; Mekonnen Gebremichael

2014-10-01T23:59:59.000Z

174

Analytic solutions for seismic travel time and ray path geometry through simple velocity models.  

SciTech Connect

The geometry of ray paths through realistic Earth models can be extremely complex due to the vertical and lateral heterogeneity of the velocity distribution within the models. Calculation of high fidelity ray paths and travel times through these models generally involves sophisticated algorithms that require significant assumptions and approximations. To test such algorithms it is desirable to have available analytic solutions for the geometry and travel time of rays through simpler velocity distributions against which the more complex algorithms can be compared. Also, in situations where computational performance requirements prohibit implementation of full 3D algorithms, it may be necessary to accept the accuracy limitations of analytic solutions in order to compute solutions that satisfy those requirements. Analytic solutions are described for the geometry and travel time of infinite frequency rays through radially symmetric 1D Earth models characterized by an inner sphere where the velocity distribution is given by the function V (r) = A-Br{sup 2}, optionally surrounded by some number of spherical shells of constant velocity. The mathematical basis of the calculations is described, sample calculations are presented, and results are compared to the Taup Toolkit of Crotwell et al. (1999). These solutions are useful for evaluating the fidelity of sophisticated 3D travel time calculators and in situations where performance requirements preclude the use of more computationally intensive calculators. It should be noted that most of the solutions presented are only quasi-analytic. Exact, closed form equations are derived but computation of solutions to specific problems generally require application of numerical integration or root finding techniques, which, while approximations, can be calculated to very high accuracy. Tolerances are set in the numerical algorithms such that computed travel time accuracies are better than 1 microsecond.

Ballard, Sanford

2007-12-01T23:59:59.000Z

175

MACCS2/Deposition Velocity Workshop | Department of Energy  

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

You are here You are here Home » MACCS2/Deposition Velocity Workshop MACCS2/Deposition Velocity Workshop The Department of Energy's Chief of Nuclear Safety hosted a MACCS2/Deposition Velocity Workshop on June 5-6, 2012, in Germantown, Maryland. Approximately 70 participants attended. The purpose of the workshop was to: Discuss MACCS2 and atmospheric dispersion models as applied to DOE consequence analysis. Discuss implementation of HSS Safety Bulletin 2011-2, Accident Analysis Parameter Update, at field sites. Develop a consistent Department-wide approach for responding to the HSS Safety Bulletin. Identify areas for improved DOE guidance for ensuring defensible consequence analyses. June Workshop Agenda- Final.docx Atmospheric Dispersion Modeling in Safety Analyses; GENII

176

Temporal Velocity Variations beneath the Coso Geothermal Field Observed  

Open Energy Info (EERE)

Velocity Variations beneath the Coso Geothermal Field Observed Velocity Variations beneath the Coso Geothermal Field Observed using Seismic Double Difference Tomography of Compressional and Shear Wave Arrival Times Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Temporal Velocity Variations beneath the Coso Geothermal Field Observed using Seismic Double Difference Tomography of Compressional and Shear Wave Arrival Times Details Activities (1) Areas (1) Regions (0) Abstract: Microseismic imaging can be an important tool for characterizing geothermal reservoirs. Since microseismic sources occur more or less continuously both due to the operations of a geothermal field and the naturally occurring background seismicity, passive seismic monitoring is well suited to quantify the temporal variations in the vicinity of a

177

Phase-Resolved Measurements of Ion Velocity in a Radio-Frequency Sheath Brett Jacobs,1,* Walter Gekelman,1  

E-Print Network (OSTI)

-induced fluorescence in a commercial plasma process- ing tool. Discharge parameters were such that the 2.2 MHz rf upon the ratio of the ion transit time through the sheath to the rf period (ion=rf) [11]. In the high-frequencyPhase-Resolved Measurements of Ion Velocity in a Radio-Frequency Sheath Brett Jacobs,1,* Walter

California at Los Angles, University of

178

Backpulse and filter feed velocity effects on Norton filter performance  

SciTech Connect

A series of tests have been conducted using the 2.2 ft{sup 2} Norton filter to solve the fouling problems observed with the ETF Norton system. The objective of these tests was to determine filter efficiency as a function of backpulse strength and feed velocity. Based on experimental results, it is recommend that the filters should be operated at the following conditions: (1) Backpulse Transmembrane Pressure/FeedTransmembrane Pressure (BP/FP) > 1.5, preferably 2 or 3. (2) Feed crossflow velocity = 6--8 f/s. It is expected that operation at these conditions should improve performance by 30--60%.

Siler, J.L.

1990-05-08T23:59:59.000Z

179

Extreme Value Analysis of Tidal Stream Velocity Perturbations  

SciTech Connect

This paper presents a statistical extreme value analysis of maximum velocity perturbations from the mean flow speed in a tidal stream. This study was performed using tidal velocity data measured using both an Acoustic Doppler Velocimeter (ADV) and an Acoustic Doppler Current Profiler (ADCP) at the same location which allows for direct comparison of predictions. The extreme value analysis implements of a Peak-Over-Threshold method to explore the effect of perturbation length and time scale on the magnitude of a 50-year perturbation.

Harding, Samuel; Thomson, Jim; Polagye, Brian; Richmond, Marshall C.; Durgesh, Vibhav; Bryden, Ian

2011-04-26T23:59:59.000Z

180

Fermi velocity renormalization and dynamical gap generation in graphene  

E-Print Network (OSTI)

We study the renormalization of the Fermi velocity by the long-range Coulomb interactions between the charge carriers in the Dirac-cone approximation for the effective low-energy description of the electronic excitations in graphene at half filling. Solving the coupled system of Dyson-Schwinger equations for the dressing functions in the corresponding fermion propagator with various approximations for the particle-hole polarization we observe that Fermi velocity renormalization effects generally lead to a considerable increase of the critical coupling for dynamical gap generation and charge-density wave formation at the semimetal-insulator transition.

C. Popovici; C. S. Fischer; L. von Smekal

2015-01-12T23:59:59.000Z

Note: This page contains sample records for the topic "high velocity sdhv" 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

Dynamic optical properties in graphene: Length versus velocity gauge  

SciTech Connect

The dynamic optical properties of graphene are theoretically investigated in both length gauge and velocity gauge in the presence of ultrafast optical radiation field. The two gauges present different results of dynamic photo-induced carriers and optical conductance due to distinct dependencies on electric field and non-resonant optical absorption, while the two gauges give identical results in the steady state time. It shows that the choice of gauge affects evidently the dynamic optical properties of graphene. The velocity gauge represents an outcome of a real physical experiment.

Dong, H. M.; Han, K., E-mail: han6409@263.net [Department of Physics, China University of Mining and Technology, Xuzhou 221116 (China); Xu, W. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Department of Physics, Yunnan University, Kunming 650091 (China)

2014-02-14T23:59:59.000Z

182

Incorporating Velocity Shear into the Magneto-Boussinesq Approximation  

E-Print Network (OSTI)

Motivated by consideration of the solar tachocline, we derive, via an asymptotic procedure, a new set of equations incorporating velocity shear and magnetic buoyancy into the Boussinesq approximation. We demonstrate, by increasing the magnetic field scale height, how these equations are linked to the magneto-Boussinesq equations of Spiegel and Weiss (1982).

Bowker, Jordan A; Kersalé, Evy

2014-01-01T23:59:59.000Z

183

THE VELOCITY DEPENDENCE OF AERODYNAMIC DRAG: A PRIMER FOR MATHEMATICIANS  

E-Print Network (OSTI)

THE VELOCITY DEPENDENCE OF AERODYNAMIC DRAG: A PRIMER FOR MATHEMATICIANS LYLE N. LONG and HOWARD­entry of the space shuttle into the earth's atmosphere. Dimensional analysis is an important tool in aerodynamics­T E X 1 #12; For detailed information on the aerodynamics and fluid mechanics pertinent to this paper

184

Estimation of boundary layer transition noise from velocity measurements  

Science Journals Connector (OSTI)

Velocity measurements of artificially generatedflow structures in the transition region of an incompressible boundary layer with zero pressure gradient are described. These measurements made in a laminar flow water channel allow calculation of the velocity normal to the wall in a turbulent spot. This velocity specifies the linearized boundary condition for the acoustic equation at the wall. The approach relates the radiated noise to fluctuations in the normal velocity at the plate through fluctuations in the displacement thickness. Although this approach has been previously proposed [H. W. Liepmann unpublished (1954) J. Laufer J. E. Ffowcs?Williams and S. Childress AGARDograph 90 39–42 (1964) G. C. Lauchle J. Acoust. Soc. Am. 69 665–671 (1981) G. C. Lauchle ASME NCA 5 31–38 (1989)] it has never been applied. The results of these experiments will be compared to concurrent experiments run in an anechoic wind tunnel. Ultimately this work will be extended to naturally occurring structures in the transition region. [Work supported by ONR under Grant ?N00014?90?J?1365.

Michael H. Krane; Wayne R. Pauley

1991-01-01T23:59:59.000Z

185

Brady 1D seismic velocity model ambient noise prelim  

SciTech Connect

Preliminary 1D seismic velocity model derived from ambient noise correlation. 28 Green's functions filtered between 4-10 Hz for Vp, Vs, and Qs were calculated. 1D model estimated for each path. The final model is a median of the individual models. Resolution is best for the top 1 km. Poorly constrained with increasing depth.

Robert J. Mellors

2013-10-25T23:59:59.000Z

186

Effect of the q-nonextensive electron velocity distribution on a magnetized plasma sheath  

SciTech Connect

In this work, a sheath model has been developed to investigate the effect of the q-nonextensive electron velocity distribution on the different characteristics of a magnetized plasma. By using Segdeev potential method, a modified Bohm criterion for a magnetized plasma with the nonextensive electron velocity distribution is derived. The sheath model is then used to analyze numerically the sheath structure under different q, the parameter quantifying the nonextensivity degree of the system. The results show that as the q-parameter decreases, the floating potential becomes more negative. The sheath length increases at the lower values of the q-parameter due to the increase in the electron population at the high-energy tail of the distribution function. As q-parameter decreases, the effective temperature of the electrons increases which results in a more extended plasma sheath. The ion velocity and density profiles for the different nonextensivity degrees of the system reflect the gyro-motion of the ions in the presence of the magnetic field. Furthermore, the results coincide with those given by the Maxwellian electron distribution function, when q tends to 1.

Safa, N. Navab, E-mail: n-navabsafa@sbu.ac.ir; Ghomi, H.; Niknam, A. R. [Laser and Plasma Research Institute, Shahid Beheshti University, Tehran 1983963113 (Iran, Islamic Republic of)

2014-08-15T23:59:59.000Z

187

SDSS 0956+5128: A BROAD-LINE QUASAR WITH EXTREME VELOCITY OFFSETS  

SciTech Connect

We report on the discovery of a Type 1 quasar, SDSS 0956+5128, with a surprising combination of extreme velocity offsets. SDSS 0956+5128 is a broad-lined quasar exhibiting emission lines at three substantially different redshifts: a systemic redshift of z {approx} 0.714 based on narrow emission lines, a broad Mg II emission line centered 1200 km s{sup -1} bluer than the systemic velocity, at z {approx} 0.707, and broad H{alpha} and H{beta} emission lines centered at z {approx} 0.690. The Balmer line peaks are 4100 km s{sup -1} bluer than the systemic redshift. There are no previously known objects with such an extreme difference between broad Mg II and broad Balmer emission. The two most promising explanations are either an extreme disk emitter or a high-velocity black hole recoil. However, neither explanation appears able to explain all of the observed features of SDSS 0956+5128, so the object may provide a challenge to our general understanding of quasar physics.

Steinhardt, Charles L.; Schramm, Malte; Silverman, John D. [Kavli IPMU, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa-shi, Chiba (Japan); Alexandroff, Rachael; Pattarakijwanich, Petchara; Strauss, Michael A. [Department of Astrophysical Sciences, Princeton University, Ivy Lane, Princeton, NJ 08544 (United States); Capak, Peter [California Institute of Technology, MC 249-17, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Civano, Francesca; Elvis, Martin [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Masters, Dan; Mobasher, Bahram [Department of Physics and Astronomy, University of California, Riverside, CA 92508 (United States)

2012-11-01T23:59:59.000Z

188

Super Star Cluster Velocity Dispersions and Virial Masses in the M82 Nuclear Starburst  

E-Print Network (OSTI)

We use high-resolution near-infrared spectroscopy from Keck Observatory to measure the stellar velocity dispersions of 19 super star clusters (SSCs) in the nuclear starburst of M82. The clusters have ages on the order of 10 Myr, which is many times longer than the crossing times implied by their velocity dispersions and radii. We therefore apply the Virial Theorem to derive the kinematic mass for 15 of the SSCs. The SSCs have masses of 2 x 10^5 to 4 x 10^6 solar masses, with a total population mass of 1.4 x 10^7 solar masses. Comparison of the loci of the young M82 SSCs and old Milky Way globular clusters in a plot of radius versus velocity dispersion suggests that the SSCs are a population of potential globular clusters. We present the mass function for the SSCs, and find a power law fit with an index of gamma = -1.91 +/- 0.06. This result is nearly identical to the mass function of young SSCs in the Antennae galaxies.

Nate McCrady; James R. Graham

2007-04-04T23:59:59.000Z

189

PROBING THE HALO FROM THE SOLAR VICINITY TO THE OUTER GALAXY: CONNECTING STARS IN LOCAL VELOCITY STRUCTURES TO LARGE-SCALE CLOUDS  

SciTech Connect

This paper presents the first potential connections made between two local features in velocity space found in a survey of M giant stars and stellar spatial inhomogeneities on global scales. Comparison to cosmological, chemodynamical stellar halo models confirms that the M giant population is particularly sensitive to rare, recent and massive accretion events. These events can give rise to locally observed velocity sequences-each made from a small fraction of debris from a massive progenitor, passing at high velocity through the survey volume, near the pericenter of the eccentric orbit of the system. The majority of the debris is found in much larger structures, whose morphologies are more cloud-like than stream-like and which lie at the orbital apocenters. Adopting this interpretation, the full-space motions represented by the observed M giant velocity features are derived under the assumption that the members within each sequence share a common space velocity. Orbit integrations are then used to trace the past and future trajectories of these stars across the sky revealing plausible associations with large, previously discovered, cloud-like structures. The connections made between nearby velocity structures and these distant clouds represent preliminary steps toward developing coherent maps of such giant debris systems. These maps promise to provide new insights into the origin of debris clouds, new probes of Galactic history and structure, and new constraints on the high-velocity tails of the local dark matter distribution that are essential for interpreting direct dark matter particle detection experiments.

Johnston, Kathryn V.; Sheffield, Allyson A. [Department of Astronomy, Columbia University, New York, NY 10027 (United States); Majewski, Steven R. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904-0818 (United States); Sharma, Sanjib [Sydney Institute for Astronomy, School of Physics, University of Sydney, NSW 2006 (Australia); Rocha-Pinto, Helio J., E-mail: kvj@astro.columbia.edu [Observatorio do Valongo, Universidade Federal do Rio de Janeiro (Brazil)

2012-11-20T23:59:59.000Z

190

Low Velocity Sphere Impact of a Soda Lime Silicate Glass  

SciTech Connect

This report summarizes TARDEC-sponsored work at Oak Ridge National Laboratory (ORNL) during the FY11 involving low velocity (< 30 m/s or < 65 mph) ball impact testing of Starphire soda lime silicate glass. The intent was to better understand low velocity impact response in the Starphire for sphere densities that bracketed that of rock. Five sphere materials were used: borosilicate glass, soda-lime silicate glass, steel, silicon nitride, and alumina. A gas gun was fabricated to produce controlled velocity delivery of the spheres against Starphire tile targets. Minimum impact velocities to initiate fracture in the Starphire were measured and interpreted in context to the kinetic energy of impact and the elastic property mismatch between the any of the five sphere-Starphire-target combinations. The primary observations from this low velocity (< 30 m/s or < 65 mph) testing were: (1) Frictional effects contribute to fracture initiation. (2) Spheres with a lower elastic modulus require less force to initiate fracture in the Starphire than spheres with a higher elastic modulus. (3) Contact-induced fracture did not initiate in the Starphire SLS for impact kinetic energies < 150 mJ. Fracture sometimes initiated or kinetic energies between {approx} 150-1100 mJ; however, it tended to occur when lower elastic modulus spheres were impacting it. Contact-induced fracture would always occur for impact energies > 1100 mJ. (4) The force necessary to initiate contact-induced fracture is higher under dynamic or impact conditions than it is under quasi-static indentation conditions. (5) Among the five used sphere materials, silicon nitride was the closest match to 'rock' in terms of both density and (probably) elastic modulus.

Wereszczak, Andrew A [ORNL; Fox, Ethan E [ORNL; Morrissey, Timothy G [ORNL; Vuono, Daniel J [ORNL

2011-10-01T23:59:59.000Z

191

Report of IAU Commission 30 on Radial Velocities (2006-2009)  

E-Print Network (OSTI)

Brief summaries are given on the following subjects: Radial velocities and exoplanets (Toward Earth-mass planets; Retired A stars and their planets; Current status and prospects); Toward higher radial velocity precision; Radial velocities and asteroseismology; Radial velocities in Galactic and extragalactic clusters; Radial velocities for field giants; Galactic structure -- Large surveys (The Geneva-Copenhagen Survey; Sloan Digital Sky Survey; RAVE); Working groups (WG on radial velocity standards; WG on stellar radial velocity bibliography; WG on the catalogue of orbital elements of spectroscopic binaries [SB9]).

G. Torres; E. V. Glushkova; J. A. Johnson; H. Levato; B. Nordström; D. Pourbaix; G. Torres; S. Udry

2008-10-24T23:59:59.000Z

192

Low velocity ion stopping in binary ionic mixtures  

SciTech Connect

Attention is focused on the low ion velocity stopping mechanisms in multicomponent and dense target plasmas built of quasiclassical electron fluids neutralizing binary ionic mixtures, such as, deuterium-tritium of current fusion interest, proton-heliumlike iron in the solar interior or proton-helium ions considered in planetology, as well as other mixtures of fiducial concern in the heavy ion beam production of warm dense matter at Bragg peak conditions. The target plasma is taken in a multicomponent dielectric formulation a la Fried-Conte. The occurrence of projectile ion velocities (so-called critical) for which target electron slowing down equals that of given target ion components is also considered. The corresponding multiquadrature computations, albeit rather heavy, can be monitored analytical through a very compact code operating a PC cluster. Slowing down results are systematically scanned with respect to target temperature and electron density, as well as ion composition.

Tashev, Bekbolat; Baimbetov, Fazylkhan [Department of Physics, Kazakh National University, Tole Bi 96, Almaty 480012 (Kazakhstan); Deutsch, Claude [LPGP (UMR-CNRS 8578), Universite Paris XI, 91405 Orsay (France); Fromy, Patrice [Direction de l'Informatique, Universite Paris XI, 91405 Orsay (France)

2008-10-15T23:59:59.000Z

193

Velocity of sound in relativistic heavy-ion collisions  

Science Journals Connector (OSTI)

We have studied the rapidity distribution of secondary hadrons produced in nucleus-nucleus collisions at ultrarelativistic energies within the ambit of the Landau’s hydrodynamical model. A reasonable description of the data can also be obtained by using the Bjorken’s hydrodynamical model if the boost invariance is restricted to a finite rapidity range. The sensitivity of the hadronic spectra on the equation of state vis-à-vis the velocity of sound has been discussed. The correlation between the velocity of sound and the freeze-out temperature has been indicated. The effects of the nonzero widths of various mesonic and baryonic degrees of freedom up to the mass value ?2.5GeV are seen to be small.

Bedangadas Mohanty and Jan-e Alam

2003-12-11T23:59:59.000Z

194

Measuring In-Situ Mdf Velocity Of Detonation  

DOE Patents (OSTI)

A system for determining the velocity of detonation of a mild detonation fuse mounted on the surface of a device includes placing the device in a predetermined position with respect to an apparatus that carries a couple of sensors that sense the passage of a detonation wave at first and second spaced locations along the fuse. The sensors operate a timer and the time and distance between the locations is used to determine the velocity of detonation. The sensors are preferably electrical contacts that are held spaced from but close to the fuse such that expansion of the fuse caused by detonation causes the fuse to touch the contact, causing an electrical signal to actuate the timer.

Horine, Frank M. (Albuquerque, NM); James, Jr., Forrest B. (Albuquerque, NM)

2005-10-25T23:59:59.000Z

195

On fuel-optimal velocity control of a motor vehicle  

Science Journals Connector (OSTI)

This paper presents the motor vehicle velocity control that, under certain well-defined conditions, ensures a minimum fuel consumption. To this purpose, a vehicle with a stepped mechanical transmission is considered, assuming that the gear is unchanged during the movement. The optimal control problem is formulated for different cases and solved by applying Pontryagin's maximum principle. Whenever there is a singular solution, it is shown to correspond to the uniform motion law. The optimal velocity controls include the following phases that may be combined in different ways: deceleration without engine shut-off (null engine power), strong decelerative braking, constant speed movement and full-throttle acceleration. Examples are presented by using the experimental data on engine fuel consumption. The stress falls on the significant reductions in fuel consumption that can be achieved compared to uniform motion.

A.P. Stoicescu

1995-01-01T23:59:59.000Z

196

Velocity renormalization in graphene from lattice Monte Carlo  

E-Print Network (OSTI)

We compute the Fermi velocity of the Dirac quasiparticles in clean graphene at the charge neutrality point for strong Coulomb coupling alpha_g. We perform a Lattice Monte Carlo calculation within the low-energy Dirac theory, which includes an instantaneous, long-range Coulomb interaction. We find a renormalized Fermi velocity v_FR > v_F, where v_F = c/300. Our results are consistent with a momentum-independent v_FR which increases approximately linearly with alpha_g, although a logarithmic running with momentum cannot be excluded at present. At the predicted critical coupling alpha_gc for the semimetal-insulator transition due to excitonic pair formation, we find v_FR/v_F = 3.3, which we discuss in light of experimental findings for v_FR/v_F at the charge neutrality point in ultra-clean suspended graphene.

Joaquín E. Drut; Timo A. Lähde

2014-03-26T23:59:59.000Z

197

The peculiar velocity field in a quintessence model  

E-Print Network (OSTI)

We investigate the evolution of matter density perturbations and some properties of the peculiar velocity field for a special class of exponential potentials in a scalar field model for quintessence, for which a general exact solution is known. The data from the 2-degree Field Galaxy Redshift Survey (2dFGRS) suggest a value of the today pressureless matter density Omega_M0 = 0.18 +- 0.05.

Claudio Rubano; Mauro Sereno

2002-03-13T23:59:59.000Z

198

Extracting Fish and Water Velocity from Doppler Profiler Data  

E-Print Network (OSTI)

Extracting Fish and Water Velocity from Doppler Profiler Data �º Ð 1 ¸ � � �¹ � Ý�¹� � 2 1 to measure fish swimming speeds. This is possible when fish form schools that are large enough so that the multiple Doppler sonar beams are sampling the fish speeds at the same time. In situations where fish

deYoung, Brad

199

Experimental investigation of velocity biasing in laser Doppler anemometry  

E-Print Network (OSTI)

Tech University; Chair of Advisory Commettee: Dr. Gerald L. Morrison The effects of several velocity bias reduction schemes were invest- igated using a 3-D laser Doppler anemometer and counter type (burst) signal processors. Amongst these schemes... was the McLaughlin Tiederman 3-D weighting factor, time between data weighting factor, equal time interval sampling and analogue instrumentation measurements. The ana- logue instrumentation measurements were obtained from the analogue frequency outputs...

Wiedner, Brian Gregory

1988-01-01T23:59:59.000Z

200

Boltzmann Solver with Adaptive Mesh in Velocity Space  

SciTech Connect

We describe the implementation of direct Boltzmann solver with Adaptive Mesh in Velocity Space (AMVS) using quad/octree data structure. The benefits of the AMVS technique are demonstrated for the charged particle transport in weakly ionized plasmas where the collision integral is linear. We also describe the implementation of AMVS for the nonlinear Boltzmann collision integral. Test computations demonstrate both advantages and deficiencies of the current method for calculations of narrow-kernel distributions.

Kolobov, Vladimir I.; Arslanbekov, Robert R. [CFD Research Corporation, 215 Wynn Dr, Huntsville, AL, 35803 (United States); Frolova, Anna A. [Dorodnicyn Computing Centre of the Russian Academy of Sciences, Vavilova Str., 40, Moscow, 119333 (Russian Federation)

2011-05-20T23:59:59.000Z

Note: This page contains sample records for the topic "high velocity sdhv" 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

Studies of the velocity fields near a submerged rectangular object  

E-Print Network (OSTI)

of the time periodic waves past a submerged rectangular object. For sotne wave conditions, large energy dissipation occurred at the submerged object due to vortex generation. The amount of energy dissipation was examined by comparing incident wave energy... object. A two component laser-Doppler anemometer (LDA) was used to obtain detailed measurements of the instantaneous velocity field and flow visualization was conducted to study the vortex structure around the submerged object. The measured wave...

Kim, Young-Ki

2012-06-07T23:59:59.000Z

202

Time, Distance, Velocity, Redshift: a personal guided tour  

E-Print Network (OSTI)

An attempt to answer the question 'Can we observe galaxies that recede faster than light ?' led to a re-examination of the notions of time, distance, velocity and redshift as they occur in newtonian physics, special relativity, general relativity and cosmology. A number of misconceptions were uncovered. It was found that, once freed of special relativity preconceptions, the above question is easily and unequivocally answered

T. Kiang

2003-08-01T23:59:59.000Z

203

Airflow Simulations around OA Intake Louver with Electronic Velocity Sensors  

SciTech Connect

It is important to control outdoor airflow rates into HVAC systems in terms of energy conservation and healthy indoor environment. Technologies are being developed to measure outdoor air (OA) flow rates through OA intake louvers on a real time basis. The purpose of this paper is to investigate the airflow characteristics through an OA intake louver numerically in order to provide suggestions for sensor installations. Airflow patterns are simulated with and without electronic air velocity sensors within cylindrical probes installed between louver blades or at the downstream face of the louver. Numerical results show quite good agreements with experimental data, and provide insights regarding measurement system design. The simulations indicate that velocity profiles are more spatially uniform at the louver outlet relative to between louver blades, that pressure drops imposed by the sensor bars are smaller with sensor bars at the louver outlet, and that placement of the sensor bars between louver blades substantially increases air velocities inside the louver. These findings suggest there is an advantage to placing the sensor bars at the louver outlet face.

Han, Hwataik; Sullivan, Douglas P.; Fisk, William J.

2009-04-01T23:59:59.000Z

204

The Velocity of Sound in an Absorptive Gas  

Science Journals Connector (OSTI)

The theory of velocity propagation in a gas as conditioned by internal energy exchanges is considered in detail for the simplest case in which the "lags" may be different—namely, the model with three sets of states. This "second order" theory is required for the interpretation of experimental results where the wave period is of the order of the lag for some states. Assuming the first vibration state of CO2 to have the largest lag in accordance with Kneser's interpretation of his recent experiments, the necessary approximations are given explicitly and the results are directly applicable to CO2. The apparent lag as measured in sound velocity experiments is not the simple stationary state mean "collision life" nor the mean life of the energy quantum except under special conditions and then for only one of the states. The velocity increment in the "resonance" region is given more accurately in terms of transition probabilities and is not described completely by the specific heats as might be expected from the "first order" theory. Contrary to the indications of the simple theory with an empirical constant the external energy is always merely the translation term. The status of the assumed lag assignment in CO2 is discussed in the light of the results and underlying theory of this paper.

D. G. Bourgin

1932-12-01T23:59:59.000Z

205

On velocities beyond the speed of light c  

E-Print Network (OSTI)

From a mathematical point of view velocities can be larger than c. It has been shown that Lorentz transformations are easily extended in Minkowski space to address velocities beyond the speed of light. Energy and momentum conservation fixes the relation between masses and velocities larger than c, leading to the possible observation of negative mass squared particles from a standard reference frame. Current data on neutrinos' mass square yeld negative values, making neutrinos as possible candidates for having speed larger than c. In this paper, an original analysis of the SN1987A supernova data is proposed. It is shown that all the data measured in '87 by all the experiments are consistent with the quantistic description of neutrinos as combination of superluminal mass eigenstates. The well known enigma on the arrival times of the neutrino bursts detected at LSD, several hours earlier than at IMB, K2 and Baksan, is explained naturally. It is concluded that experimental evidence for superluminal neutrinos was recorded since the SN1987A explosion, and that data are quantitatively consistent with the introduction of tachyons in Einstein's equation.

S. Giani

1997-12-04T23:59:59.000Z

206

Effect of H2/CO ratio and N2/CO2 dilution rate on laminar burning velocity of syngas investigated by direct measurement and simulation  

Science Journals Connector (OSTI)

Abstract Laminar burning velocities of syngas/air premixed flames, varying with H2/CO ratio (from 5/95 to 75/25) and N2 or CO2 dilution rate (from 0% to 60%), were accurately measured using a Teflon coated Heat Flux burner and OH-PLIF based Bunsen flame method. Experiments were carried out at atmospheric pressure and room temperature, with fuel/air equivalence ratios ranging from fuel-lean to fuel-rich. Coupled with experimental data, three chemical kinetic mechanisms, namely GRI-Mech 3.0, USC Mech II and Davis H2–CO mechanism, were validated. The Davis H2–CO and USC Mech II mechanisms appear to provide a better prediction for the laminar burning velocity. The laminar burning velocity variations with H2 and dilution gas contents were systematically investigated. For given dilution gas fraction, the laminar burning velocity reduction rate was enhanced as H2/CO ratio increasing. Effects of the syngas components and equivalence ratio variation on the concentrations of radical H and OH were also studied. It appears that there is a strong linear correlation between the laminar burning velocity and the maximum concentration of the H radical in the reaction zone for syngas. This characteristic is exclusively different from that in methane air premixed flame. These findings indicated that the high thermal diffusivity of the H radical played an important role in the laminar burning velocity enhancement and affected the laminar burning velocity reduction rate under dilution condition.

Z.H. Wang; W.B. Weng; Y. He; Z.S. Li; K.F. Cen

2014-01-01T23:59:59.000Z

207

TURBULENCE-INDUCED RELATIVE VELOCITY OF DUST PARTICLES. I. IDENTICAL PARTICLES  

SciTech Connect

We study the relative velocity of inertial particles suspended in turbulent flows and discuss implications for dust particle collisions in protoplanetary disks. We simulate a weakly compressible turbulent flow, evolving 14 particle species with friction timescale, ?{sub p}, covering the entire range of scales in the flow. The particle Stokes numbers, St, measuring the ratio of ?{sub p} to the Kolmogorov timescale, are in the range 0.1 ?< St ?< 800. Using simulation results, we show that the model by Pan and Padoan gives satisfactory predictions for the rms relative velocity between identical particles. The probability distribution function (PDF) of the relative velocity is found to be highly non-Gaussian. The PDF tails are well described by a 4/3 stretched exponential function for particles with ?{sub p} ? 1-2 T{sub L}, where T{sub L} is the Lagrangian correlation timescale, consistent with a prediction based on PP10. The PDF approaches Gaussian only for very large particles with ?{sub p} ?> 54 T{sub L}. We split particle pairs at given distances into two types with low and high relative speeds, referred to as continuous and caustic types, respectively, and compute their contributions to the collision kernel. Although amplified by the effect of clustering, the continuous contribution vanishes in the limit of infinitesimal particle distance, where the caustic contribution dominates. The caustic kernel per unit cross section rises rapidly as St increases toward ? 1, reaches a maximum at ?{sub p} ? 2 T{sub L}, and decreases as ?{sub p}{sup -1/2} for ?{sub p} >> T{sub L}.

Pan, Liubin [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Padoan, Paolo, E-mail: lpan@cfa.harvard.edu, E-mail: ppadoan@icc.ub.edu [ICREA and ICC, University of Barcelona, Marti i Franquès 1, E-08028 Barcelona (Spain)

2013-10-10T23:59:59.000Z

208

Measurements of Spatially Resolved Velocity Variations in Shock Compressed Heterogeneous Materials Using a Line-Imaging Velocity Interferometer  

SciTech Connect

Relatively straightforward changes in the optical design of a conventional optically recording velocity interferometer system (ORVIS) can be used to produce a line-imaging velocity interferometer wherein both temporal and spatial resolution can be adjusted over a wide range. As a result line-imaging ORVIS can be tailored to a variety of specific applications involving dynamic deformation of heterogeneous materials as required by the characteristic length scale of these materials (ranging from a few {micro}m for ferroelectric ceramics to a few mm for concrete). A line-imaging ORVIS has been successfully interfaced to the target chamber of a compressed gas gun driver and fielded on numerous tests in combination with simultaneous measurements using a dual delay-leg, ''push-pull'' VISAR system. These tests include shock loading of glass-reinforced polyester composites, foam reverberation experiments (measurements at the free surface of a thin aluminum plate impacted by foam), and measurements of dispersive velocity in a shock-loaded explosive simulant (sugar). Comparison of detailed spatially-resolved material response to the spatially averaged VISAR measurements will be discussed.

ASAY,JAMES R.; CHHABILDAS,LALIT C.; KNUDSON,MARCUS D.; TROTT,WAYNE M.

1999-09-01T23:59:59.000Z

209

Spectroscopic measurement of ion temperature and ion velocity distributions in the flux-coil generated FRC  

SciTech Connect

One aim of the flux-coil generated field reversed configuration at Tri Alpha Energy (TAE) is to establish the plasma where the ion rotational energy is greater than the ion thermal energy. To verify this, an optical diagnostic was developed to simultaneously measure the Doppler velocity-shift and line-broadening using a 0.75 m, 1800 groves/mm, spectrometer. The output spectrum is magnified and imaged onto a 16-channel photomultiplier tube (PMT) array. The individual PMT outputs are coupled to high-gain, high-frequency, transimpedance amplifiers, providing fast-time response. The Doppler spectroscopy measurements, along with a survey spectrometer and photodiode-light detector, form a suite of diagnostics that provide insights into the time evolution of the plasma-ion distribution and current when accelerated by an azimuthal-electric field.

Gupta, D.; Gota, H.; Hayashi, R.; Kiyashko, V.; Morehouse, M.; Primavera, S. [Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States); Bolte, N. [Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States); Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Marsili, P. [Department of Physics, University of Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Roche, T. [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Wessel, F. [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States)

2010-10-15T23:59:59.000Z

210

Photons from Heavy-Ion Collisions at Fermi Velocity  

E-Print Network (OSTI)

'I ~ (+l Ii & & .~ I + I I 'f Il I I PHYSICAL REVIEW C VOLUME 35, NUMBER 5 MAY 1987 Photons from heavy-ion collisions at Fermi velocity Che Ming Ko Center for Theoretical Physics, Physics Department and Cyclotron Institute, Texas Ad... from the first col- lision model are slightly diff'erent from theirs as we treat the distortion of the Fermi spheres more realistically. The angular distribution for 30-MeV photon emission is shown in Fig. 2. The solid curve is the calculated...

Ko, Che Ming; Alchelin, J.

1987-01-01T23:59:59.000Z

211

Derivation of site-specific relationships between hydraulic parameters and p-wave velocities based on hydraulic and seismic tomography  

SciTech Connect

In this study, hydraulic and seismic tomographic measurements were used to derive a site-specific relationship between the geophysical parameter p-wave velocity and the hydraulic parameters, diffusivity and specific storage. Our field study includes diffusivity tomograms derived from hydraulic travel time tomography, specific storage tomograms, derived from hydraulic attenuation tomography, and p-wave velocity tomograms, derived from seismic tomography. The tomographic inversion was performed in all three cases with the SIRT (Simultaneous Iterative Reconstruction Technique) algorithm, using a ray tracing technique with curved trajectories. The experimental set-up was designed such that the p-wave velocity tomogram overlaps the hydraulic tomograms by half. The experiments were performed at a wellcharacterized sand and gravel aquifer, located in the Leine River valley near Göttingen, Germany. Access to the shallow subsurface was provided by direct-push technology. The high spatial resolution of hydraulic and seismic tomography was exploited to derive representative site-specific relationships between the hydraulic and geophysical parameters, based on the area where geophysical and hydraulic tests were performed. The transformation of the p-wave velocities into hydraulic properties was undertaken using a k-means cluster analysis. Results demonstrate that the combination of hydraulic and geophysical tomographic data is a promising approach to improve hydrogeophysical site characterization.

Brauchler, R.; Doetsch, J.; Dietrich, P.; Sauter, M.

2012-01-10T23:59:59.000Z

212

The radial velocity profile of the filament galaxies in the vicinity of the Virgo cluster as a test of gravity  

E-Print Network (OSTI)

The radial velocities of the galaxies in the vicinity of a massive cluster shows deviation from the pure Hubble flow due to their gravitational interaction with the cluster. According to a recent study of Falco et al. with a high-resolution N-body simulation based on General Relativity (GR), the radial velocity profile of the galaxies located at distances larger than three times the virial radius of a neighbour cluster has a universal shape and could be reconstructed from direct observables provided that the galaxies are distributed along one dimensional filament. Analyzing the narrow filamentary structure identified by Kim et al. in the vicinity of the Virgo cluster from the NASA-Sloan-Atlas catalog, we reconstruct the radial velocity profile of the Virgo filament galaxies and compare it with the universal formula derived by Falco et al. It is found that unless the virial mass of the Virgo cluster exceeds $10^{15}\\,h^{-1}M_{\\odot}$ the universal formula fails to describe the reconstructed radial velocity pro...

Lee, Jounghun; Rey, Soo-Chang

2015-01-01T23:59:59.000Z

213

Light bullets and supercontinuum spectrum during femtosecond pulse filamentation under conditions of anomalous group-velocity dispersion in fused silicalicati  

SciTech Connect

We report the results of theoretical and experimental research on spectrum transformation and spatiotemporal distribution of the femtosecond laser radiation intensity during filamentation in fused silica. The formation of light bullets with a high power density is first observed in a femtosecond laser pulse in the anomalous group velocity dispersion regime at a wavelength of 1800 nm. The minimum duration of the light bullet is about two oscillation cycles of the light field. (extreme light fields and their applications)

Chekalin, Sergei V; Kompanets, V O; Smetanina, E O; Kandidov, V P

2013-04-30T23:59:59.000Z

214

Low-velocity cosmic strings in accelerating universe  

E-Print Network (OSTI)

We study the model of the homogeneous and isotropic universe with non-zero cosmological constant filled with a perfect gas of low-velocity cosmic strings (LambdaCS model). It is shown that pressure-free matter can obtain the properties of a gas of low-velocity cosmic strings, if matter is affected by inertial force as described by Sciama's inertial force law. We take notice of the fact that this law, which corresponds to one of the realizations of Mach's principle, follows from quantum geometrodynamical approach. The exact solutions of the Einstein equations for the LambdaCS model are found. It is demonstrated that this model is equivalent to the open de Sitter model. In the limit of zero cosmological constant the corresponding universe evolves as a Milne universe, but in contrast to it, such a universe contains matter with nonzero energy density. The Whitrow-Randall equation is re-derived. We draw a comparison of the standard LambdaCDM and LambdaCS models. It turns out that after the scale transformation of ...

,

2011-01-01T23:59:59.000Z

215

Measurements of parallel electron velocity distributions using whistler wave absorption  

SciTech Connect

We describe a diagnostic to measure the parallel electron velocity distribution in a magnetized plasma that is overdense ({omega}{sub pe} > {omega}{sub ce}). This technique utilizes resonant absorption of whistler waves by electrons with velocities parallel to a background magnetic field. The whistler waves were launched and received by a pair of dipole antennas immersed in a cylindrical discharge plasma at two positions along an axial background magnetic field. The whistler wave frequency was swept from somewhat below and up to the electron cyclotron frequency {omega}{sub ce}. As the frequency was swept, the wave was resonantly absorbed by the part of the electron phase space density which was Doppler shifted into resonance according to the relation {omega}-k{sub ||v||} = {omega}{sub ce}. The measured absorption is directly related to the reduced parallel electron distribution function integrated along the wave trajectory. The background theory and initial results from this diagnostic are presented here. Though this diagnostic is best suited to detect tail populations of the parallel electron distribution function, these first results show that this diagnostic is also rather successful in measuring the bulk plasma density and temperature both during the plasma discharge and into the afterglow.

Thuecks, D. J.; Skiff, F.; Kletzing, C. A. [Department of Physics and Astronomy, University of Iowa, 203 Van Allen Hall, Iowa City, Iowa 52242 (United States)

2012-08-15T23:59:59.000Z

216

Cosmic density and velocity fields in Lagrangian perturbation theory  

E-Print Network (OSTI)

A first- and second-order relation between cosmic density and peculiar-velocity fields is presented. The calculation is purely Lagrangian and it is derived using the second-order solutions of the Lagrange-Newton system obtained by Buchert & Ehlers. The procedure is applied to two particular solutions given generic initial conditions. In this approach, the continuity equation yields a relation between the over-density and peculiar-velocity fields that automatically satisfies Euler's equation because the orbits are derived from the Lagrange-Newton system. This scheme generalizes some results obtained by Nusser et al. (1991) in the context of the Zel'dovich approximation. As opposed to several other reconstruction schemes, in this approach it is not necessary to truncate the expansion of the Jacobian given by the continuity equation in order to calculate a first- or second-order expression for the density field. In these previous schemes, the density contrast given by (a) the continuity equation and (b) Euler's equation are mutually incompatible. This inconsistency arises as a consequence of an improper handling of Lagrangian and Eulerian coordinates in the analysis. Here, we take into account the fact that an exact calculation of the density is feasible in the Lagrangian picture and therefore an accurate and consistent description is obtained.

Mikel Susperregi; Thomas Buchert

1997-08-04T23:59:59.000Z

217

Diagnosis of ion velocity distribution from pin to plate geometry in atmospheric argon dielectric barrier discharge  

SciTech Connect

A new method, fast Fourier transform, is presented to calculate ion velocity distribution by analyzing electromagnetic radiation signal from plasma. This method is based on a dipole model that does not require the assumption of thermodynamic equilibrium. To understand the discharge evolution, the ion velocity distribution is calculated in different oscillation cycles. Results show that the ion velocity distribution deviates from Maxwell distribution over time. The ion velocity and relative ion number fluctuate regularly with time.

Qi, Bing; Pan, Lizhu; Huang, Jianjun; Liu, Ying [Applied Low Temperature Plasma Laboratory, Shenzhen Key Laboratory of Sensors Technology, School of Physics, Shenzhen University, Shenzhen 518060 (China)] [Applied Low Temperature Plasma Laboratory, Shenzhen Key Laboratory of Sensors Technology, School of Physics, Shenzhen University, Shenzhen 518060 (China)

2013-07-15T23:59:59.000Z

218

Anticavitation protection of pressure outlets through regulation of velocities in wall layer of the flow  

Science Journals Connector (OSTI)

1. The tests showed that an installation forming a continuous low-velocity flow along a wall comprising a solid ...

P. R. Khlopenkov; G. A. Chepaikin

1976-08-01T23:59:59.000Z

219

Analysis and forecasting of wind velocity in chetumal, quintana roo, using the single exponential smoothing method  

Science Journals Connector (OSTI)

In this paper the analysis and forecasting of wind velocities in Chetumal, Quintana Roo, Mexico is presented. Measurements were made by the Instituto de Investigaciones Eléctricas (IIE) during two years, from 2004 to 2005. This location exemplifies the wind energy generation potential in the Caribbean coast of Mexico that could be employed in the hotel industry in the next decade. The wind speed and wind direction were measured at 10 m above ground level. Sensors with high accuracy and a low starting threshold were used. The wind velocity was recorded using a data acquisition system supplied by a 10 W photovoltaic panel. The wind speed values were measured with a frequency of 1 Hz and the average wind speed was recorded considering regular intervals of 10 min. First a statistical analysis of the time series was made in the first part of the paper through conventional and robust measures. Also the forecasting of the last day of measurements was made utilizing the single exponential smoothing method (SES). The results showed a very good accuracy of the data with this technique for an ? value of 0.9. Finally the SES method was compared with the artificial neural network (ANN) method showing the former better results.

E. Cadenas; O.A. Jaramillo; W. Rivera

2010-01-01T23:59:59.000Z

220

Characterization of Vertical Velocity and Drop Size Distribution Parameters in Widespread Precipitation at ARM Facilities  

SciTech Connect

Extended, high-resolution measurements of vertical air motion and median volume drop diameter D0 in widespread precipitation from three diverse Atmospheric Radiation Measurement Program (ARM) locations [Lamont, Oklahoma, Southern Great Plains site (SGP); Niamey, Niger; and Black Forest, Germany] are presented. The analysis indicates a weak (0-10 cm{sup -1}) downward air motion beneath the melting layer for all three regions, a magnitude that is to within the typical uncertainty of the retrieval methods. On average, the hourly estimated standard deviation of the vertical air motion is 0.25 m s{sup -1} with no pronounced vertical structure. Profiles of D0 vary according to region and rainfall rate. The standard deviation of 1-min-averaged D0 profiles for isolated rainfall rate intervals is 0.3-0.4 mm. Additional insights into the form of the raindrop size distribution are provided using available dual-frequency Doppler velocity observations at SGP. The analysis suggests that gamma functions better explain paired velocity observations and radar retrievals for the Oklahoma dataset. This study will be useful in assessing uncertainties introduced in the measurement of precipitation parameters from ground-based and spaceborne remote sensors that are due to small-scale variability.

Giangrande S. E.; Luke, E. P.; Kollias, P.

2012-02-01T23:59:59.000Z

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221

Effects of neutral interactions on velocity-shear-driven plasma waves  

SciTech Connect

In a laboratory experiment, we demonstrate the substantial effects that collisions between charged and neutral particles have on low-frequency (?{sub i}????????{sub e}) shear-driven electrostatic lower hybrid waves in a plasma. We establish a strong (up to 2.5?kV/m) highly localized electric field with a length scale shorter than the ion gyroradius, so that the ions in the plasma, unlike the electrons, do not develop the full E?×?B drift velocity. The resulting shear in the particle velocities initiates the electron-ion hybrid (EIH) instability, and we observe the formation of strong waves in the vicinity of the shear with variations in plasma densities of 10% or greater. Our experimental configuration allows us to vary the neutral background density by more than a factor of two while holding the charged particle density effectively constant. Not surprisingly, increasing the neutral density decreases the growth rate/saturation amplitude of the waves and increases the threshold electric field necessary for wave formation, but the presence of neutrals affects the dominant wave frequency as well. We show that a 50% increase in the neutral density decreases the wave frequency by 20% while also suppressing the electric field dependence of the frequency that is observed when fewer neutrals are present. The majority of these effects, as well as the values of the frequencies we observe, closely match the predictions of previously developed linear EIH instability theory, for which we present the results of a numerical solution.

Enloe, C. L. [Physics Department, US Air Force Academy, Colorado Springs, Colorado 80840 (United States); Tejero, E. M.; Amatucci, W. E.; Crabtree, C.; Ganguli, G. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Sotnikov, V. [Sensors Directorate, Air Force Research Laboratory, Dayton, Ohio 45433 (United States)

2014-06-15T23:59:59.000Z

222

GENERALIZED 2D EULER-BOUSSINESQ EQUATIONS WITH A SINGULAR VELOCITY  

E-Print Network (OSTI)

GENERALIZED 2D EULER-BOUSSINESQ EQUATIONS WITH A SINGULAR VELOCITY DURGA KC, DIPENDRA REGMI a system of equations generalizing the two-dimensional incompressible Boussinesq equa- tions. The velocity- value problem of this generalized Boussinesq equations when the velocity is "double logarithmically

Wu, Jiahong

223

Evidence for correlation of electrical resistivity and seismic velocity in heterogeneous near-surface materials  

E-Print Network (OSTI)

-surface materials. For both trends, the resistivity (r) and p-wave velocity (Vp) are related in the form Log10 r = m resistivity and seismic velocity in heterogeneous near-surface materials, Geophys. Res. Lett., 30(7), 1373Evidence for correlation of electrical resistivity and seismic velocity in heterogeneous near

Meju, Max

224

Nested Velocity Feedback Control -1 Presented at CS 2007 Dr Richard Mitchell 2007  

E-Print Network (OSTI)

Nested Velocity Feedback Control - 1 Presented at CS 2007 © Dr Richard Mitchell 2007 Nested tolerant to changes in the plant under control #12;Nested Velocity Feedback Control - 2 Presented at CS path #12;Nested Velocity Feedback Control - 3 Presented at CS 2007 © Dr Richard Mitchell 2007 Cherry

Mitchell, Richard

225

Modeling and Control of High-Velocity Oxygen-Fuel (HVOF) Thermal Spray: A Tutorial Review  

E-Print Network (OSTI)

vs. Fuzzy Logic: Simple Tools to Predict and Control Complexfuzzy logic (Ref 73, 74). For the HVOF thermal spray process, a feedback control

Li, Mingheng; Christofides, Panagiotis D.

2009-01-01T23:59:59.000Z

226

Broad absorption line quasars with redshifted troughs: high-velocity infall or rotationally dominated outflows?  

Science Journals Connector (OSTI)

......Section-5.5). 18 J1034 has an unresolved, red object 4.62arcsec away which was not...K., Kilic M., Anderson S. F., Gates E. AJ (2008) 136:76. Hall P. B...J. ApJ (2012) 746:2. Knigge C. , Woods J. A., Drew J. E. MNRAS (1995) 273......

P. B. Hall; W. N. Brandt; P. Petitjean; I. Pâris; N. Filiz Ak; Yue Shen; R. R. Gibson; É. Aubourg; S. F. Anderson; D. P. Schneider; D. Bizyaev; J. Brinkmann; E. Malanushenko; V. Malanushenko; A. D. Myers; D. J. Oravetz; N. P. Ross; A. Shelden; A. E. Simmons; A. Streblyanska; B. A. Weaver; D. G. York

2013-01-01T23:59:59.000Z

227

High-resolution velocity field imaging around a borehole: Excavation Damaged Zone characterization  

E-Print Network (OSTI)

in the laboratory offers a large number of boreholes. These boreholes form linear excavations with a perfectly round to deploy significant resources with a large number of sensors and boreholes (Balland et al, 2009). Instead induced around a borehole drilled for survey purposes. This would involve the installation of several

Boyer, Edmond

228

EROSIVE WEAR OF DUCTILE METALS BY A PARTICLE-LADEN HIGH-VELOCITY LIQUID-JET  

E-Print Network (OSTI)

angle Concentration of coal ( 0 /o) XBL 8012-2452 20% by wtscale) Equivalent Diameter (11m) Coal Al 2 o 3 SiC Metals (for Fossil Energy, Office of Coal Research, Materials and

Li, Simon Ka-Keung

2014-01-01T23:59:59.000Z

229

Burning Velocities in Catalytically Assisted Self-Propagating High-Temperature Combustion Synthesis Systems  

E-Print Network (OSTI)

the compact yielding a solid product, typically a metal carbide or boride, for example, Me s C s 3 MeC s (1) where Me is a transition metal species such as titanium or tantalum, and C is carbon (graphite, carbon) is included in the system. The transport agent aids in the transport of the metal or carbon (or boron

Wooldridge, Margaret S.

230

Modeling of Sediment Bed Behavior for Critical Velocity in Horizontal Piping  

SciTech Connect

This paper compares results from a predictive tool for modeling transport of a multiphase mixture (solids in a liquid) in a pipeline, (up to and including plugging) with experiments performed to support the Hanford site’s Waste Treatment and Immobilization Plant (WTP). The treatment of high-level waste at the DOE Office of River Protection’s WTP will involve the transfer of high solid content suspensions through pipelines. Pipeline plugging was identified as a significant potential issue by a panel of external experts. In response to their concerns an experimental effort was initiated at PNNL to determine the critical velocities for a variety of operating conditions. A computational method has been developed to predict the dynamic behavior of a sediment bed in response to the surrounding suspension flow. The flow field is modeled using a lattice kinetics method, similar to the lattice Boltzmann method, which scales very well on highly parallel computers. Turbulent quantities are calculated using a k-epsilon RANS model. This work is part of a larger effort to develop a process simulation capability for a wide range of applications. Solids are represented using two different continuum fields. The suspended solids are treated as passive scalars in the flow field, including terms for hindered settling and Brownian diffusion. Normal stresses created by the irreversible collisions of particles during shearing are added to the pressure tensor. The sediment bed interface is represented using a continuum phase field with a diffuse interface. The bed may change with time due to settling, erosion and deposition through convection. The erosion rates are calculated using the local shear stress obtained from the turbulence model. The method is compared with data from the PNNL pipeline experiments conducted at PNNL (Poloski et al. 2008). The experimental flow loop consists of 3-inch schedule 40 piping with instrumentation for determining flow rate and pressure gradient. The simulant test particles ranged in density from 2.5 to 8 g/cc while the nominal particle size ranged from 10 to 100 ?m. At the beginning of each test, the slurry flow velocity was nominally set to 8 ft/sec. The flow was incrementally ramped down, and a steady-state pressure gradient was obtained at each flow condition. A rise in pressure gradient as the flow rate drops indicates that the pipe cross-sectional area is beginning to fill with sediment. This point is referred to as the “critical velocity”. Visualization information is provided using Electrical Resistance Tomography (ERT). The paper will show favorable comparison of results with data.

Rector, David R.; Stewart, Mark L.; Poloski, Adam P.

2009-10-01T23:59:59.000Z

231

Lifetime of nuclear velocity dispersion drops in barred galaxies  

E-Print Network (OSTI)

We have made hydro/N-body simulations with and without star formation to shed some light on the conditions under which a central kinematically cold stellar component (characterized by a velocity dispersion drop or \\sigma-drop) could be created in a hot medium (e.g. a bulge) and survive enough time to be observed. We found that the timescale for a \\sigma-drop formation could be short (less than 500 Myr) whereas its lifetime could be long (more than 1 Gyr) provided that the central region is continuously or regularly fed by fresh gas which leads to a continuous star formation activity. Star formation in the central region, even at a low rate as 1M_{sol} yr^{-1}, is mandatory to sustain a permanent \\sigma-drop by replacing heated particles by new low-\\sigma ones. We moreover show that as soon as star formation is switched off, the \\sigma-drop begins to disappear.

Herve Wozniak; Nicolas Champavert

2006-03-29T23:59:59.000Z

232

Active galactic nuclei-driven outflows without immediate quenching in simulations of high-redshift disc galaxies  

Science Journals Connector (OSTI)

......outflows with velocities km1 and mass outflow rates...Outflowing winds escape perpendicular...summary, high-mass outflow rates...drives high-velocity winds. Since BH...face-on maps of maximum outflow velocity with 1kpc...of stellar mass of the galaxy......

J. M. Gabor; Frédéric Bournaud

2014-01-01T23:59:59.000Z

233

Continued Evaluation of the Pulse-Echo Ultrasonic Instrument for Critical Velocity Determination during Hanford Tank Waste Transfer Operations  

SciTech Connect

Laboratory (PNNL) conducted an extensive evaluation of the ability of three ultrasonic instruments to detect critical velocity for a broad range of simulated Hanford nuclear waste streams containing particles with mean particle sizes of >50 microns. Evaluations were perform using the pipe loop at the Process Development Laboratory – East (PDL-E) at PNNL that was designed and built to evaluate the pipeline plugging issue during slurry transfer operations at the Hanford Waste Treatment Plant. In 2011 the ability of the ultrasonic PulseEcho system to detect critical velocity continued to be evaluated using the PDL-E flow loop and new simulants containing high-density particles with a mean particle size of < 15 microns. The PDL-E flow loop was modified for the 2011 testing to include a new test section that contained 5-MHz and 10-MHz ultrasonic transducers non-invasively mounted to schedule 40 pipe. The test section also contained reference instrumentation to facilitate direct comparison of the real-time PulseEcho transducer responses with experimentally observed critical velocities. This paper presents the results from the 2011 PulseEcho evaluation using a variety of simulated Hanford nuclear waste streams that were selected to encompass the expected high-level waste feed properties.

Denslow, Kayte M.; Bontha, Jagannadha R.; Adkins, Harold E.; Jenks, Jeromy WJ; Burns, Carolyn A.; Schonewill, Philip P.; Hopkins, Derek F.; Thien, Michael G.; Wooley, Theodore A.

2012-04-01T23:59:59.000Z

234

Distributions of velocity and turbulence in a parallel flow along an asymmetric rod bundle  

SciTech Connect

An experimental investigation was performed to obtain detailed information on the velocity and turbulence distributions in a parallel turbulent flow through an asymmetric rod bundle. The rod bundle consisted of four parallel rods arranged asymmetrically in a rectangular channel. The pitch-to-diameter (P/D) ratio of the rods was P/D = 1.072. Experimental results were obtained in two wall subchannels with wall-to-diameter (W/D) ratios of W/D = 1.096 and 1.048, respectively. The experimental results showed high anisotropy of the momentum transport, particularly in the gaps of the rod bundle. Comparisons between the measured wall shear stresses and data computed by the VELASCO code show considerable differences, particularly for the wall subchannel with W/D = 1.048.

Rehme, K.

1982-10-01T23:59:59.000Z

235

Performance testing of lead free primers: blast waves, velocity variations, and environmental testing  

E-Print Network (OSTI)

Results are presented for lead free primers based on diazodinitrophenol (DDNP)compared with tests on lead styphnate based primers. First, barrel friction measurements in 5.56 mm NATO are presented. Second, shot to shot variations in blast waves are presented as determined by detonating primers in a 7.62x51mm rifle chamber with a firing pin, but without any powder or bullet loaded and measuring the blast wave at the muzzle with a high speed pressure transducer. Third, variations in primer blast waves, muzzle velocities, and ignition delay are presented after environmental conditioning (150 days) for two lead based and two DDNP based primers under cold and dry (-25 deg C,0% relative humidity), ambient (20 deg C, 50% relative humidity), and hot & humid (50 deg C, 100% relative humidity) conditions in 5.56 mm NATO. Taken together, these results indicate that DDNP based primers are not sufficiently reliable for service use.

Courtney, Elya; Summer, Peter David; Courtney, Michael

2014-01-01T23:59:59.000Z

236

Optical pin apparatus for measuring the arrival time and velocity of shock waves and particles  

DOE Patents (OSTI)

An apparatus for the detection of the arrival and for the determination of the velocity of disturbances such as shock-wave fronts and/or projectiles. Optical pins using fluid-filled microballoons as the light source and an optical fiber as a link to a photodetector have been used to investigate shock-waves and projectiles. A microballoon filled with a noble gas is affixed to one end of a fiber-optic cable, and the other end of the cable is attached to a high-speed streak camera. As the shock-front or projectile compresses the microballoon, the gas inside is heated and compressed producing a bright flash of light. The flash of light is transmitted via the optic cable to the streak camera where it is recorded. One image-converter streak camera is capable of recording information from more than 100 microballoon-cable combinations simultaneously.

Benjamin, R.F.

1983-10-18T23:59:59.000Z

237

Optical pin apparatus for measuring the arrival time and velocity of shock waves and particles  

DOE Patents (OSTI)

An apparatus for the detection of the arrival and for the determination of the velocity of disturbances such as shock-wave fronts and/or projectiles. Optical pins using fluid-filled microballoons as the light source and an optical fiber as a link to a photodetector have been used to investigate shock-waves and projectiles. A microballoon filled with a noble gas is affixed to one end of a fiber-optic cable, and the other end of the cable is attached to a high-speed streak camera. As the shock-front or projectile compresses the microballoon, the gas inside is heated and compressed producing a bright flash of light. The flash of light is transmitted via the optic cable to the streak camera where it is recorded. One image-converter streak camera is capable of recording information from more than 100 microballoon-cable combinations simultaneously.

Benjamin, Robert F. (315 Rover Blvd., Los Alamos, NM 87544)

1987-01-01T23:59:59.000Z

238

Optical pin apparatus for measuring the arrival time and velocity of shock waves and particles  

DOE Patents (OSTI)

An apparatus is disclosed for the detection of the arrival and for the determination of the velocity of disturbances such as shock-wave fronts and/or projectiles. Optical pins using fluid-filled microballoons as the light source and an optical fiber as a link to a photodetector have been used to investigate shock-waves and projectiles. A microballoon filled with a noble gas is affixed to one end of a fiber-optic cable, and the other end of the cable is attached to a high-speed streak camera. As the shock-front or projectile compresses the microballoon, the gas inside is heated and compressed producing a bright flash of light. The flash of light is transmitted via the optic cable to the streak camera where it is recorded. One image-converter streak camera is capable of recording information from more than 100 microballoon-cable combinations simultaneously. 3 figs.

Benjamin, R.F.

1987-03-10T23:59:59.000Z

239

Particle in cell simulations of Buneman instability of a current-driven plasma with q-nonextensive electron velocity distribution  

SciTech Connect

The nonlinear evolution of low frequency Buneman instability in an unmagnetized current-driven plasma with q-nonextensive electron velocity distribution is investigated using particle in cell simulation. Simulation results show that the generation of electron phase space holes and the counter-streaming current induced in the plasma strongly depend on the q-parameter. It is found that by increasing the nonextensive parameter, the distribution of electron density becomes highly peaked. This density steepening or grating-like pattern occurs at the saturation time. In addition, a generalized dispersion relation is obtained using the kinetic theory. Analysis of the dispersion relation and the temporal evolution of the electric field energy density reveal that the growth rate of instability increases by increasing the q-parameter. Finally, the results of Maxwellian and q-nonextensive velocity distributions have been compared and discussed.

Niknam, A. R., E-mail: a-niknam@sbu.ac.ir; Roozbahani, H.; Komaizi, D. [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran (Iran, Islamic Republic of); Hashemzadeh, M. [Faculty of Physics, Shahrood University, Shahrood (Iran, Islamic Republic of)

2014-09-15T23:59:59.000Z

240

Velocity Anisotropy of shales and sandstones from core sample and well log on the Norwegian Continental shelf.  

E-Print Network (OSTI)

??Abstract Velocity anisotropy referse the directional inequality of velocity on the subsurface. Often sedimentary rocks are anisotropic and occurse at all scales from core plugs… (more)

Meseret, Malaku

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high velocity sdhv" 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

Resuspension studies in cylindrical microcosms: Effects of stirring velocity on the dynamics of redox sensitive elements in a coastal sediment  

Science Journals Connector (OSTI)

Effects of resuspension on the release of dissolved, redox sensitive ... At current velocities below the threshold velocity for resuspension (37 cm s-1), Mn release...

Mario Hose Calado Laima; Henning Matthiesen; Lars Chresten Lund-Hansen…

1998-12-01T23:59:59.000Z

242

Radiation Hydrodynamics Test Problems with Linear Velocity Profiles  

SciTech Connect

As an extension of the works of Coggeshall and Ramsey, a class of analytic solutions to the radiation hydrodynamics equations is derived for code verification purposes. These solutions are valid under assumptions including diffusive radiation transport, a polytropic gas equation of state, constant conductivity, separable flow velocity proportional to the curvilinear radial coordinate, and divergence-free heat flux. In accordance with these assumptions, the derived solution class is mathematically invariant with respect to the presence of radiative heat conduction, and thus represents a solution to the compressible flow (Euler) equations with or without conduction terms included. With this solution class, a quantitative code verification study (using spatial convergence rates) is performed for the cell-centered, finite volume, Eulerian compressible flow code xRAGE developed at Los Alamos National Laboratory. Simulation results show near second order spatial convergence in all physical variables when using the hydrodynamics solver only, consistent with that solver's underlying order of accuracy. However, contrary to the mathematical properties of the solution class, when heat conduction algorithms are enabled the calculation does not converge to the analytic solution.

Hendon, Raymond C. [Los Alamos National Laboratory; Ramsey, Scott D. [Los Alamos National Laboratory

2012-08-22T23:59:59.000Z

243

Teleseismic evidence for a low-velocity body under the Coso geothermal area  

Open Energy Info (EERE)

Teleseismic evidence for a low-velocity body under the Coso geothermal area Teleseismic evidence for a low-velocity body under the Coso geothermal area Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Teleseismic evidence for a low-velocity body under the Coso geothermal area Details Activities (1) Areas (1) Regions (0) Abstract: Teleseismic P wave arrivals were recorded by a dense array of seismograph stations located in the Coso geothermal area, California. The resulting pattern of relative residuals an area showing approximately 0.2-s excess travel time that migrates with changing source azimuth, suggesting that the area is the 'delay shadow' produced by a deep, low-velocity body. Inversion of the relative residual data for three-dimensional velocity structure determines the lateral variations in velocity to a depth of 22.5

244

Propagation Distance Required to Reach Steady-State Detonation Velocity in Finite-Sized Charges  

E-Print Network (OSTI)

The decay of a detonation wave from its initial CJ velocity to its final, steady state velocity upon encountering a finite thickness or diameter charge is investigated numerically and theoretically. The numerical simulations use an ideal gas equation of state and pressure dependent reaction rate in order to ensure a stable wave structure. The confinement is also treated as an ideal gas with variable impedance. The velocity decay along the centerline is extracted from the simulations and compared to predictions base on a front evolution equation that uses the steady state detonation velocity-front curvature relation ($D_n-\\kappa$). This model fails to capture the finite signaling speed of the leading rarefaction resulting from the interaction with the yielding confinement. This signaling speed is verified to be the maximum signal velocity occurring in the ideal ZND wave structure of the initial CJ velocity. A simple heuristic model based on the rarefaction generated by a one-dimensional interaction between the...

Li, Jianling; Higgins, Andrew J

2014-01-01T23:59:59.000Z

245

A numerical study of geometry dependent errors in velocity, temperature, and density measurements from single grid planar retarding potential analyzers  

SciTech Connect

Planar retarding potential analyzers (RPAs) have been utilized numerous times on high profile missions such as the Communications/Navigation Outage Forecast System and the Defense Meteorological Satellite Program to measure plasma composition, temperature, density, and the velocity component perpendicular to the plane of the instrument aperture. These instruments use biased grids to approximate ideal biased planes. These grids introduce perturbations in the electric potential distribution inside the instrument and when unaccounted for cause errors in the measured plasma parameters. Traditionally, the grids utilized in RPAs have been made of fine wires woven into a mesh. Previous studies on the errors caused by grids in RPAs have approximated woven grids with a truly flat grid. Using a commercial ion optics software package, errors in inferred parameters caused by both woven and flat grids are examined. A flat grid geometry shows the smallest temperature and density errors, while the double thick flat grid displays minimal errors for velocities over the temperature and velocity range used. Wire thickness along the dominant flow direction is found to be a critical design parameter in regard to errors in all three inferred plasma parameters. The results shown for each case provide valuable design guidelines for future RPA development.

Davidson, R. L.; Earle, G. D.; Heelis, R. A. [William B. Hanson Center for Space Sciences, University of Texas at Dallas, 800 W. Campbell Road, WT15, Richardson, Texas 75080 (United States); Klenzing, J. H. [Space Weather Laboratory/Code 674, Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)

2010-08-15T23:59:59.000Z

246

Laser initiated reactions in N{sub 2}O clusters studied by time-sliced ion velocity imaging technique  

SciTech Connect

Laser initiated reactions in N{sub 2}O clusters were studied by a time-sliced velocity imaging technique. The N{sub 2}O clusters, (N{sub 2}O){sub n}, generated by supersonic expansion were irradiated by an ultraviolet laser around 204 nm to convert reactant pairs, O({sup 1}D{sub 2})-(N{sub 2}O){sub n?1}. The NO molecules formed from these reactant pairs were ionized by the same laser pulse and their velocity distribution was determined by the time-sliced velocity imaging technique. At low nozzle pressure, lower than 1.5 atm, the speed distribution in the frame moving with the clusters consists of two components. These components were ascribed to the products appeared in the backward and forward directions in the center-of-mass frame, respectively. The former consists of the vibrational ground state and the latter consists of highly vibrational excited states. At higher nozzle pressure, a single broad speed distribution became dominant for the product NO. The pressure and laser power dependences suggested that this component is attributed to the product formed in the clusters larger than dimer, (N{sub 2}O){sub n} (n ? 3)

Honma, Kenji [Graduate School of Material Science, University of Hyogo, 3-2-1 Kohto, Kamigori, Hyogo 678-1297 (Japan)] [Graduate School of Material Science, University of Hyogo, 3-2-1 Kohto, Kamigori, Hyogo 678-1297 (Japan)

2013-07-28T23:59:59.000Z

247

Estimation of Velocity Distribution and Suspended Sediment Discharge in Open Channels Using Entropy  

E-Print Network (OSTI)

up a coordinate system?????..??????.. 30 4.1.2 Velocity isovels?????..??????...?????.. 31 4.1.3 Cumulative distribution function?????...?????.. 32 4.1.4 Verification of cumulative distribution function?????. 38 4.2 1D velocity distribution... a and G values??????... 56 Figure 5.2 Dimensionless velocity distribution for various m values (data from Ponte Felcino River, Italy)????????????????... 59 Figure 5.3 The relationship between G and um/umax??????????... 60 Figure 5.4 Distribution...

Cui, Huijuan

2011-08-08T23:59:59.000Z

248

Experimental techniques for measuring temperature and velocity fields to improve the use and validation of building heat transfer models  

SciTech Connect

When modeling thermal performance of building components and envelopes, researchers have traditionally relied on average surface heat-transfer coefficients that often do not accurately represent surface heat-transfer phenomena at any specific point on the component being evaluated. The authors have developed new experimental techniques that measure localized surface heat-flow phenomena resulting from convection. The data gathered using these new experimental procedures can be used to calculate local film coefficients and validate complex models of room and building envelope heat flows. These new techniques use a computer-controlled traversing system to measure both temperatures and air velocities in the boundary layer near the surface of a building component, in conjunction with current methods that rely on infrared (IR) thermography to measure surface temperatures. Measured data gathered using these new experimental procedures are presented here for two specimens: (1) a Calibrated Transfer Standard (CTS) that approximates a constant-heat-flux, flat plate; and (2) a dual-glazed, low-emittance (low-e), wood-frame window. The specimens were tested under steady-state heat flow conditions in laboratory thermal chambers. Air temperature and mean velocity data are presented with high spatial resolution (0.25- to 25-mm density). Local surface heat-transfer film coefficients are derived from the experimental data by means of a method that calculates heat flux using a linear equation for air temperature in the inner region of the boundary layer. Local values for convection surface heat-transfer rate vary from 1 to 4.5 W/m{sup 2} {center_dot} K. Data for air velocity show that convection in the warm-side thermal chamber is mixed forced/natural, but local velocity maximums occur from 4 to 8 mm from the window glazing.

Griffith, Brent; Turler, Daniel; Goudey, Howdy; Arasteh, Dariush

1998-04-01T23:59:59.000Z

249

CALIBRATING STELLAR VELOCITY DISPERSIONS BASED ON SPATIALLY RESOLVED H-BAND SPECTRA FOR IMPROVING THE M{sub BH}-{sigma}{sub *} RELATION  

SciTech Connect

To calibrate stellar velocity dispersion measurements from optical and near-IR stellar lines, and to improve the black hole mass (M{sub BH})-stellar velocity dispersion ({sigma}{sub *}) relation, we measure {sigma}{sub *} based on high-quality H-band spectra for a sample of 31 nearby galaxies, for which dynamical M{sub BH} is available in the literature. By comparing velocity dispersions measured from stellar lines in the H-band with those measured from optical stellar lines, we find no significant difference, suggesting that optical and near-IR stellar lines represent the same kinematics and that dust effect is negligible for early-type galaxies. Based on the spatially resolved rotation and velocity dispersion measurements along the major axis of each galaxy, we find that a rotating stellar disk is present for 80% of galaxies in the sample. For galaxies with a rotation component, {sigma}{sub *} measured from a single aperture spectrum can vary by up to {approx}20%, depending on the size of the adopted extraction aperture. To correct for the rotational broadening, we derive luminosity-weighted {sigma}{sub *} within the effective radius of each galaxy, providing uniformly measured velocity dispersions to improve the M{sub BH}-{sigma}{sub *} relation.

Kang, Wol-Rang; Woo, Jong-Hak; Park, Daeseong [Astronomy Program, Department of Physics and Astronomy, Seoul National University, 1 Gwanak-ro Gwanak-gu, Seoul, 151-742 (Korea, Republic of)] [Astronomy Program, Department of Physics and Astronomy, Seoul National University, 1 Gwanak-ro Gwanak-gu, Seoul, 151-742 (Korea, Republic of); Schulze, Andreas [Kavli Institute for Astronomy and Astrophysics, Peking University, 100871 Beijing (China)] [Kavli Institute for Astronomy and Astrophysics, Peking University, 100871 Beijing (China); Riechers, Dominik A. [Astronomy Department, Cornell University, 220 Space Science Building, Ithaca, NY 14853 (United States)] [Astronomy Department, Cornell University, 220 Space Science Building, Ithaca, NY 14853 (United States); Kim, Sang Chul [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of)] [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Smolcic, Vernesa, E-mail: woo@astro.snu.ac.kr [Physics Department, University of Zagreb, Bijenicka cesta 32, 10002 Zagreb (Croatia)] [Physics Department, University of Zagreb, Bijenicka cesta 32, 10002 Zagreb (Croatia)

2013-04-10T23:59:59.000Z

250

Model of bubble velocity vector measurement in upward and downward bubbly two-phase flows using a four-sensor optical probe  

Science Journals Connector (OSTI)

Abstract The knowledge of bubble behaviors is of considerable significance for a proper understanding and modeling of two-phase flows. To obtain the information on the bubble motion, a novel model was developed, by which the bubble velocity vector can be directly calculated from six time intervals measured with a four-sensor probe. The measurements of local bubble velocity vector and void fraction were performed in both upward and downward bubbly flows by using a four-sensor optical probe. The area-averaged void fraction and bubble velocity obtained from the probe agree well with those measured by other cross-calibration methods, and the measurement errors are within 15% under various flow conditions. Experimental results of the bubble velocity vector reveal that the bubble lateral migration may be suppressed in upward flows, but be strengthened in downward flows as the liquid flow rate increases. Also, with an increase in gas flow rate, the bubble velocity distribution varies into the power–law profile in upward flows, but into an off-center peak profile in downward flows. In addition, the void fraction shows a core peak distribution at low void fraction for downward flows, but a wall peak distribution for upward flows. However, when the void fraction is relatively high, it displays an off-center peak distribution for downward flows but a core peak distribution for upward flows.

Daogui Tian; Changqi Yan; Licheng Sun

2015-01-01T23:59:59.000Z

251

AN ASSESSMENT OF THE ACCURACY OF MAGENTIC RESONANCE PHASE VELOCITY MAPPING IN TURBULENT FLOW THROUGH ORIFICES.  

E-Print Network (OSTI)

?? Magnetic resonance phase velocity mapping (MRPVM) is an established clinical technique to measure blood flow. The acquired information can be used to diagnose a… (more)

Pidaparthi, Sahitya

2011-01-01T23:59:59.000Z

252

Test Loop Demonstration and Evaluation of Slurry Transfer Line Critical Velocity Measurement Instruments  

SciTech Connect

This report presents the results of the evaluation of three ultrasonic sensors for detecting critical velocity during slurry transfer between the Hanford tank farms and the WTP.

Bontha, Jagannadha R.; Jenks, Jeromy WJ; Morgen, Gerald P.; Peters, Timothy J.; Wilcox, Wayne A.; Adkins, Harold E.; Burns, Carolyn A.; Greenwood, Margaret S.; MacFarlan, Paul J.; Denslow, Kayte M.; Schonewill, Philip P.; Blanchard, Jeremy; Baer, Ellen BK

2010-07-31T23:59:59.000Z

253

Particle Velocity Distributions and Ionization Processes in a Gas-Puff Z Pinch  

Science Journals Connector (OSTI)

We have measured the time-dependent radial velocity distributions of singly to five times ionized ions in an imploding plasma shell by observing the spectral shapes and intensities of emission lines in various directions. An ionization wave propagating much faster than the local radial ion velocities is observed. The ionization front velocity is found to be consistent with estimates of electron heat conduction into the plasma-neutral layer. The ionization and velocity histories of the particles are experimentally determined. The mechanisms of momentum transfer to the particles are also determined and compared with existing models.

M. E. Foord; Y. Maron; G. Davara; L. Gregorian; A. Fisher

1994-06-13T23:59:59.000Z

254

Hot Carrier Velocities in Doped and in Ultra-pure Germanium Crystals at Millikelvin Temperatures  

Science Journals Connector (OSTI)

We present new experimental data for the electron and hole velocity laws in Ge at 20 mK as a function of the field between...

J. Domange; E. Olivieri; A. Broniatowski

2012-06-01T23:59:59.000Z

255

E-Print Network 3.0 - air stream velocities Sample Search Results  

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

and Environment GIS Lab Collection: Engineering 11 1 Copyright 1997 by ASME 1997 ASME Fluids Engineering Division Summer Meeting Summary: or structure velocity u Streamwise...

256

E-Print Network 3.0 - acoustic particle velocity Sample Search...  

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

of Mathematics, Purdue University Collection: Mathematics 44 AIAA 2001-2961 The Rijke Tube Revisited via Laboratory Summary: product of acoustic velocity and pressure, known as...

257

Design of a hypersonic waterjet apparatus driven by high explosives  

SciTech Connect

The design and construction of a hypersonic waterjet apparatus is described. Jet velocities from 0.5 to 5 km/s have been achieved using a high explosive charge. Images are obtained in situ on various target substrates using a high-speed framing camera. Experimental results are shown for the impact of high velocity waterjets on propellants and high explosive samples. By observing the impact of the waterjet at a wide range of velocities a safety threshold can be determined where no reaction takes place.

Weeks, Brandon L.; Klosterman, John; Worsey, Paul N.

2001-08-01T23:59:59.000Z

258

Preliminary assessment of the velocity pump reaction turbine as a geothermal total-flow expander  

SciTech Connect

A preliminary evaluation was made of the Velocity Pump Reaction Turbine (VPRT) as a total flow expander in a geothermal-electric conversion cycle. Values of geofluid effectiveness of VPRT systems were estimated for conditions consisting of: a 360/sup 0/ geothermal resource, 60/sup 0/F wet-bulb ambient temperature, zero and 0.003 mass concentrations of dissolved noncondensible gas in the geofluid, 100 and 120/sup 0/F condensing temperatures, and engine efficiencies ranging from 0.4 to 1.0. Achievable engine efficiencies were estimated to range from 0.47 to 0.77, with plant geofluid effectiveness values ranging as high as 9.5 Watt hr/lbm geofluid for the 360/sup 0/F resource temperature. This value is competitive with magnitudes of geofluid effectiveness projected for advanced binary plants, and is on the order of 40% higher than estimates for dual-flash steam and other total flow systems reviewed. Because of its potentially high performance and relative simplicity, the VPRT system appears to warrant further investigation toward its use in a well-head geothermal plant.

Demuth, O.J.

1984-06-01T23:59:59.000Z

259

Tuning in on Cepheids: Radial velocity amplitude modulations. A source of systematic uncertainty for Baade-Wesselink distances  

E-Print Network (OSTI)

[Abridged] I report the discovery of modulations in radial velocity (RV) curves of four Galactic classical Cepheids and investigate their impact as a systematic uncertainty for Baade-Wesselink distances. Highly precise Doppler measurements were obtained using the Coralie high-resolution spectrograph since 2011. Particular care was taken to sample all phase points in order to very accurately trace the RV curve during multiple epochs and to search for differences in linear radius variations derived from observations obtained at different epochs. Different timescales are sampled, ranging from cycle-to-cycle to months and years. The unprecedented combination of excellent phase coverage obtained during multiple epochs and high precision enabled the discovery of significant modulation in the RV curves of the short-period s-Cepheids QZ Normae and V335 Puppis, as well as the long-period fundamental mode Cepheids l Carinae and RS Puppis. The modulations manifest as shape and amplitude variations that vary smoothly on ...

Anderson, Richard I

2014-01-01T23:59:59.000Z

260

THE 2D EULER-BOUSSINESQ EQUATIONS WITH A LOGARITHMICALLY SUPERCRITICAL VELOCITY  

E-Print Network (OSTI)

THE 2D EULER-BOUSSINESQ EQUATIONS WITH A LOGARITHMICALLY SUPERCRITICAL VELOCITY DURGA KC, DIPENDRA of solutions to a generalized 2D Euler-Boussinesq systems of equations with a logarithmically super- critical Euler- Boussinesq system of equations with a singular velocity t + u · = x1 , t + u · + = 0, u

Wu, Jiahong

Note: This page contains sample records for the topic "high velocity sdhv" 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

Electron velocity distribution function in a plasma with temperature gradient and in the presence of suprathermal  

E-Print Network (OSTI)

Electron velocity distribution function in a plasma with temperature gradient and in the presence of suprathermal electrons: application to incoherent-scatter plasma lines P. Guio1 , J. Lilensten2 , W. Kofman2 arbitrary velocity distribution function with cylindrical symmetry along the magnetic ®eld. The electron

Paris-Sud XI, Université de

262

Monetary circulation, the paradox of profits, and the velocity of money1  

E-Print Network (OSTI)

Monetary circulation, the paradox of profits, and the velocity of money1 Olivier ALLAIN Université of money is higher than one because some monetary units are used in several transactions of goods. Key words: paradox of profits, circulation, endogenous money, velocity of money, stock-flow consistent

Paris-Sud XI, Université de

263

Dip-moveout error in transversely isotropic media with linear velocity variation in depth  

SciTech Connect

Levin modeled the moveout, within common-mid-point (CMP) gathers, of reflection from plane-dipping reflectors beneath homogeneous, transversely isotropic media. For some media, when the axis of symmetry for the anisotropy was vertical, the author found departures in stacking velocity from predictions based upon the familiar cosine-of-dip correction for isotropic media. Here, the author does similar tests, again with transversely isotropic models with vertical axis of symmetry, but now allowing the medium velocity of vary linearly with depth. Results for the same four anisotropic media studied by Levin show behavior of dip-corrected stacking velocity with reflector dip that, for all velocity gradients considered, differs little from that for the counterpart homogeneous media. As with isotropic media, travel times in an inhomogeneous, transversely isotropic medium can be modeled adequately with a homogeneous model with vertical velocity equal to the vertical rms velocity of the inhomogeneous medium. In practice, dip-moveout (DMO) is based on the assumption that either the medium is homogeneous or its velocity varies with depth, but in both cases isotropy is assumed. It turns out that for only one of the traversely isotropic media considered here--shale-limestone--would v(z) DMO fail to give an adequate correction within CMP gathers. For the shale-limestone, fortuitously the constant-velocity DMO gives a better moveout correction than does the v(z) DMO.

Larner, K.L. (Colorado School of Mines, Golden, CO (United States). Dept. of Geophysics)

1993-10-01T23:59:59.000Z

264

Dip-moveout error in transversely isotropic media with linear velocity variation in depth  

SciTech Connect

Levin (1990) modeled the moveout, within Common-midpoint (CMP) gathers, of reflections from plane-dipping reflectors beneath homogeneous, transversely isotropic media. For some media, when the axis of symmetry for the anisotropy was vertical, he found departures in stacking velocity from predictions based upon the familiar cosine-of-dip correction for isotropic media. Here, I do similar tests, again with transversely isotropic models with vertical axis of symmetry, but now allowing the medium velocity to vary linearly with depth. Results for the same four anisotropic media studied by Levin show behavior of dip-corrected stacking velocity with reflector dip that, for all velocity gradients considered, differs little from that for the counterpart homogeneous media. As with isotropic media, traveltimes in an inhomogeneous, transversely isotropic medium can be modeled adequately with a homogeneous model with vertical velocity equal to the vertical rms velocity of the inhomogeneous medium. In practice, dip-moveout (DMO) is based on the assumption that either the medium is homogeneous or its velocity varies with depth, but in both cases isotropy is assumed. It turns out that for only one of the transversely isotropic media considered here --shale-limestone -- would v(z) DMO fail to give an adequate correction within CMP gathers. For the shale-limestone, fortuitously the constant-velocity DMO gives a better moveout correction than does the v(z) DMO.

Larner, K.

1992-01-01T23:59:59.000Z

265

Dip-moveout error in transversely isotropic media with linear velocity variation in depth  

SciTech Connect

Levin (1990) modeled the moveout, within Common-midpoint (CMP) gathers, of reflections from plane-dipping reflectors beneath homogeneous, transversely isotropic media. For some media, when the axis of symmetry for the anisotropy was vertical, he found departures in stacking velocity from predictions based upon the familiar cosine-of-dip correction for isotropic media. Here, I do similar tests, again with transversely isotropic models with vertical axis of symmetry, but now allowing the medium velocity to vary linearly with depth. Results for the same four anisotropic media studied by Levin show behavior of dip-corrected stacking velocity with reflector dip that, for all velocity gradients considered, differs little from that for the counterpart homogeneous media. As with isotropic media, traveltimes in an inhomogeneous, transversely isotropic medium can be modeled adequately with a homogeneous model with vertical velocity equal to the vertical rms velocity of the inhomogeneous medium. In practice, dip-moveout (DMO) is based on the assumption that either the medium is homogeneous or its velocity varies with depth, but in both cases isotropy is assumed. It turns out that for only one of the transversely isotropic media considered here --shale-limestone -- would v(z) DMO fail to give an adequate correction within CMP gathers. For the shale-limestone, fortuitously the constant-velocity DMO gives a better moveout correction than does the v(z) DMO.

Larner, K.

1992-10-01T23:59:59.000Z

266

Design Through Operation of an Image-Based Velocity Estimation System for Mars Landing  

Science Journals Connector (OSTI)

During the Mars Exploration Rover (MER) landings, the Descent Image Motion Estimation System (DIMES) was used for horizontal velocity estimation. The DIMES algorithm combined measurements from a descent camera, a radar altimeter, and an inertial measurement ... Keywords: DIMES, Mars Exploration Rover, Mars lander, computer vision, feature tracking, robotics, velocity estimation

Andrew Johnson; Reg Willson; Yang Cheng; Jay Goguen; Chris Leger; Miguel Sanmartin; Larry Matthies

2007-09-01T23:59:59.000Z

267

Velocities of deep water reservoir sands De-hua Han, University of Houston  

E-Print Network (OSTI)

Velocities of deep water reservoir sands De-hua Han, University of Houston M. Batzle, Colorado for porosity reduction, which incorporates sediment texture such as grain size and sorting. Measured data suggest that porosity, fluid saturation and differential pressure are main parameters to affect velocities

268

On the Velocity of an Implicit Surface JOS STAM and RYAN SCHMIDT  

E-Print Network (OSTI)

On the Velocity of an Implicit Surface JOS STAM and RYAN SCHMIDT Autodesk Research In this paper we a definite velocity. For ex- Authors' addresses: J. Stam and R. Schmidt, Autodesk, Inc., 210 King Street East, Toronto, Ontario, Canada, M5A 1J7; e-mail: Jos.Stam@autodesk.com, rms@dgp.toronto.edu. Permission to make

Kazhdan, Michael

269

A Virtual Velocity Attractor, Harmonic Potential Approach for Joint planning and control of a UAV  

E-Print Network (OSTI)

A Virtual Velocity Attractor, Harmonic Potential Approach for Joint planning and control of a UAV vehicles (UAVs). The method indirectly controls the trajectory of a UAV by regulating its velocity using planner into a well-behaved control signal that can be fed to the actuator of the UAV. I. Introduction

Masoud, Ahmad A.

270

Experimental investigation of burning velocities of ultra-wet methane-air-steam mixtures  

E-Print Network (OSTI)

Experimental investigation of burning velocities of ultra-wet methane-air-steam mixtures Eric Abstract Global burning velocities of methane-air-steam mixtures are measured on prismatic laminar Bunsen flames and lifted turbulent V-flames for various preheating temperatures, equivalence ratios and steam

Paris-Sud XI, Université de

271

Three-Dimensional Structure and Evolution of the Vertical Velocity and Divergence Fields in the MJO  

Science Journals Connector (OSTI)

The features in the planetary-scale wind field that shape the MJO-related vertical velocity field are examined using the linear analysis protocol based on the daily global velocity potential field described in a companion paper, augmented by a ...

Ángel F. Adames; John M. Wallace

2014-12-01T23:59:59.000Z

272

Complete CFD analysis of a Velocity XL-5 RG with flight-test verification  

E-Print Network (OSTI)

The Texas A&M Flight Research Laboratory (FRL) recently received delivery of its newest aircraft, the Velocity XL-5 RG. The Velocity can fly faster than the other aircraft owned by the FRL and does not have a propeller in the front of the aircraft...

Schouten, Shane Michael

2008-10-10T23:59:59.000Z

273

Investigating the velocity structure and X-ray observable properties of simulated galaxy clusters with PHOX  

Science Journals Connector (OSTI)

......is essential for mass estimates based on...motions in the gas velocity field within galaxy...et-al. 2012) maps, obtained with X-ray...on the turbulent velocities in a set of galaxy...the large atomic mass of the Fe-xxv ion...supernova (SN) driven winds (Springel Hernquist......

V. Biffi; K. Dolag; H. Böhringer

2013-01-01T23:59:59.000Z

274

Spatially resolved velocity maps of halo gas around two intermediate-redshift galaxies  

Science Journals Connector (OSTI)

......with the circular velocity of the halo, which is related to halo mass according to km s1...representing halo mass in units of 1012Mo...sightlines near G1 show a velocity width of deltav 90...Detailed H-I maps of nearby galaxy...absorption due to recycled winds (e.g. Oppenheimer......

Hsiao-Wen Chen; Jean-René Gauthier; Keren Sharon; Sean D. Johnson; Preethi Nair; Cameron J. Liang

2014-01-01T23:59:59.000Z

275

Velocity statistics in excited granular media W. Losert, D. G. W. Cooper, and J. Delour  

E-Print Network (OSTI)

Velocity statistics in excited granular media W. Losert, D. G. W. Cooper, and J. Delour Department; accepted for publication 7 May 1999 We present an experimental study of velocity statistics for a partial of parameters accelerations 3­8 times the gravitational acceleration , the probability distribution P

Gollub, Jerry P.

276

Dynamically balanced absolute sea level of the global ocean derived from near-surface velocity observations  

E-Print Network (OSTI)

Dynamically balanced absolute sea level of the global ocean derived from near-surface velocity distribution of the global ocean is computed for the first time from observations of near-surface velocity distribution. NCEP reanalysis winds are used to compute the force due to Ekman currents. The mean sea level

277

The CP2 star ff 2 CVn: radial velocity, magnetic field,  

E-Print Network (OSTI)

with the areas of the magnetic poles (in case of Cr) as with the regions where the magnetic field lines haveThe CP2 star ff 2 CVn: radial velocity, magnetic field, and element distribution G. Hildebrandt­ metric observations made in Tautenburg the radial velocity and the strength of the magnetic field

278

Shirokov's contracting lifetimes and the interpretation of velocity eigenstates for unstable quantons  

E-Print Network (OSTI)

This paper is concerned with the interpretation of velocity eigenstates for unstable quantons, their relationship to space like momentum eigenstates for such quantons and the explanation of Shirokovs contracting lifetimes for such velocity eigenstates. It is an elaboration of a portion of the authors earlier study.

Gordon N. Fleming

2009-11-02T23:59:59.000Z

279

Static Friction Phenomena The following static friction phenomena have a direct dependency on velocity.  

E-Print Network (OSTI)

Coulomb Friction Viscous Friction Stribeck Friction Static Friction Phenomena The following static friction phenomena have a direct dependency on velocity. Static Friction Model: Friction force opposes the direction of motion when the sliding velocity is zero. Coulomb Friction Model: Friction force

Simpkins, Alex

280

Acoustic holography for piston sound radiation with non-uniform velocity profiles  

E-Print Network (OSTI)

Acoustic holography for piston sound radiation with non-uniform velocity profiles Ronald M. Aarts results for the radiation of sound due to a non-uniformly moving, baffled, circular piston for estimating the radially symmetric part of a velocity profile (baffled- piston radiation) from on

Note: This page contains sample records for the topic "high velocity sdhv" 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

NOTES AND CORRESPONDENCE The Effect of Radial Velocity Gridding Artifacts on Variationally  

E-Print Network (OSTI)

Retrieved Vertical Velocities SCOTT COLLIS AND ALAIN PROTAT Centre for Australian Weather and Climate of 2 m s21 . To investigate the impact on vertical velocities re- trieved from a real weather event of metrics (often referred to as cost functions) to be minimized, in this case using a conjugate gradient

Protat, Alain

282

The influence of toughening-particles in CFRPs on low velocity impact damage resistance performance  

E-Print Network (OSTI)

The influence of toughening-particles in CFRPs on low velocity impact damage resistance performance.bull@soton.ac.uk Abstract The role of particle-toughening for increasing impact damage resistance in carbon fibre reinforced velocity impacts ranging from 25 J to 50 J to establish the impact damage resistance of each material

283

Sound beyond the speed of light: Measurement of negative group velocity in an acoustic loop filter  

E-Print Network (OSTI)

Sound beyond the speed of light: Measurement of negative group velocity in an acoustic loop filter of magnitude difference between the speeds of sound and light. © 2007 American Institute of Physics. DOI: 10,2 A central issue is whether the speed of light in vacuum c constituted an upper limit to the group velocity

Robertson, William

284

P wave velocity variations in the Coso region, California, derived from  

Open Energy Info (EERE)

P wave velocity variations in the Coso region, California, derived from P wave velocity variations in the Coso region, California, derived from local earthquake travel times Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: P wave velocity variations in the Coso region, California, derived from local earthquake travel times Details Activities (1) Areas (1) Regions (0) Abstract: Inversion of 4036 P wave travel time residuals from 429 local earthquakes using a tomographic scheme provides information about three-dimensional upper crustal velocity variations in the Indian Wells Valley-Coso region of southeastern California. The residuals are calculated relative to a Coso-specific velocity model, corrected for station elevation, weighted, and back-projected along their ray paths through models defined with layers of blocks. Slowness variations in the surface

285

Deeply-scaled GaN high electron mobility transistors for RF applications  

E-Print Network (OSTI)

Due to the unique combination of large critical breakdown field and high electron velocity, GaN-based high electron mobility transistors (HEMTs) have great potential for next generation high power RF amplifiers. The ...

Lee, Dong Seup

2014-01-01T23:59:59.000Z

286

Modification of Electron Velocity Distribution in Bounded Plasmas by  

E-Print Network (OSTI)

. However, kinetic studies of HT [7,8] reveal the depletion of the high energy tail of EVDF elastic inelastic true SEEyield Energy (eV) 0 500 1000 0 1 2 3 0.01 0.1 1 10 100 1000 0.01 0.1 1 10 100-neutral collisions versus the electron energy. The SEE coefficient (ratio of emitted and incident electron currents

Kaganovich, Igor

287

Velocity-Change-Space-based dynamic motion planning for mobile robots navigation  

Science Journals Connector (OSTI)

Abstract This paper deals with the problem of dynamic motion planning in an unknown environment, where the workspace is cluttered with moving obstacles and robots. First, we give the principle of hybrid velocity obstacles, the definition of the preferred velocity and the collision-avoidance behavior. Second, we give new rules for the size regulation of obstacles and the kinematic and dynamic constraints of wheeled robot. Then, we establish a new Velocity Change Space (VCS) using the changes of the speed and direction of the robot?s velocity as coordinate axis, and map the goal, velocity obstacles and dynamics constraints in this space. Finally, we explore the dynamic motion planning problem in the VCS. Mobile robot making motion planning in its velocity change window is achieved in multiple sensing-acting time steps, and directly gets the new velocity using point search and multi-objective optimization. We apply VCS-based motion planning methods to mobile robots, and simulation is used to illustrate the collision-free, interactive, un-conservative, foresighted and multi-objective optimized navigation of mobile robots.

Xunyu Zhong; Xungao Zhong; Xiafu Peng

2014-01-01T23:59:59.000Z

288

The Equation of State of Water and Seawater as Determined from Sound Velocity Data  

Science Journals Connector (OSTI)

Using the high?pressure (0 to 1000 bars) sound?velocity measurements of Wilson (1960) an equation of state for PVT properties of water and seawater has been developed based on a modified Tait equation of the form V°?V P V°P = 1 B+A 1 P+A 2 P 2 in which V° is the specific volume at atmospheric pressure VP the specific volume at pressureP and B A 1 and A 2 are functions of temperature and salinity. The equation has been fit with a maximum deviation in compressibility of 0.01×10?6 bar?1 for seawater and 0.02×10?6 bar?1 for pure water. The data from this equation will yield specific volumes that show the excellent consistency of Ekman's (1908) measurements with the sound data. The results for pure water show a definite shift in Kell and Whalley's (1965) measurements and the superiority of the PVT data generated from the sound data to direct experimental measurements.

Rana A. Fine; Dong Ping Wang

1973-01-01T23:59:59.000Z

289

Anomalous fluctuations of vertical velocity of Earth and their possible implications for earthquakes  

SciTech Connect

High-quality measurements of seismic activities around the world provide a wealth of data and information that are relevant to understanding of when earthquakes may occur. If viewed as complex stochastic time series, such data may be analyzed by methods that provide deeper insights into their nature, hence leading to better understanding of the data and their possible implications for earthquakes. In this paper, we provide further evidence for our recent proposal [P. Mansour et al., Phys. Rev. Lett. 102, 014101 (2009)] for the existence of a transition in the shape of the probability density function (PDF) of the successive detrended increments of the stochastic fluctuations of Earth's vertical velocity V{sub z}, collected by broadband stations before moderate and large earthquakes. To demonstrate the transition, we carried out extensive analysis of the data for V{sub z} for 12 earthquakes in several regions around the world, including the recent catasrophic one in Haiti. The analysis supports the hypothesis that before and near the time of an earthquake, the shape of the PDF undergoes significant and discernable changes, which can be characterized quantitatively. The typical time over which the PDF undergoes the transition is about 5-10 h prior to a moderate or large earthquake.

Manshour, Pouya [Department of Physics, Sharif University of Technology, Tehran 11155-9161 (Iran, Islamic Republic of); Ghasemi, Fatemeh; Sahimi, Muhammad [Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-1211 (United States); Matsumoto, T. [Division of Physics and Astronomy, Graduate School of Science, Kyoto University, Kitashirakawa Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan); CNRS UMR 6202, Observatoire de la Cote d'Azur, BP 4229, 06304 Nice Cedex 4 (France); Gomez, J. [Earth Sciences Department, University of Zaragoza, Zaragoza 50009 (Spain); Peinke, J. [Institute of Physics, Carl von Ossietzky University, D-26111 Oldenburg (Germany); Pacheco, A. F. [Department of Theoretical Physics, University of Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza (Spain); Tabar, M. Reza Rahimi [Department of Physics, Sharif University of Technology, Tehran 11155-9161 (Iran, Islamic Republic of); CNRS UMR 6202, Observatoire de la Cote d'Azur, BP 4229, 06304 Nice Cedex 4 (France); Institute of Physics, Carl von Ossietzky University, D-26111 Oldenburg (Germany); Fachbereich Physik, Universitaet Osnabrueck, Barbarastrasse, 49706 Osnabrueck (Germany)

2010-09-15T23:59:59.000Z

290

Doppler Effect in Spectra of Positive Rays of Uniform Velocity in Argon, Neon, Helium  

Science Journals Connector (OSTI)

Ions of argon, neon, helium, formed in a low voltage arc have been accelerated to high speeds in a short electric field, forming beams of positive ions which all have the same energy. The spectra of the beams of positive rays of uniform energy observed in the direction of motion show a characteristic Doppler effect, with displaced lines fully as sharp as the rest lines. With the exception of the very intense ?3418 of neon, the arc lines of argon and neon have no Doppler effect, while the lines of the first spark spectrum are accompanied by sharp displaced lines only slightly less intense than the rest lines, whose separation corresponds accurately to the speeds acquired by singly charged ions in the accelerating field, for velocities 9000 to 28,000 volts and several lines of higher spark spectra were observed with displaced lines also corresponding to singly charged ions. Satisfactory observations are made at pressure about 5×10-3 mm, the intensity and sharpness of the displaced lines diminishing with increasing pressure. In helium, the arc lines show relatively faint displaced lines corresponding to singly charged ions; one spark line ?4686 was accompanied by a relatively intense displaced line, while the only other spark line observed, ?4541, had no Doppler effect.

Anna I. McPherson

1933-11-01T23:59:59.000Z

291

Study of velocity-changing collisions in excited Kr using saturation spectroscopy  

Science Journals Connector (OSTI)

A saturated-absorption experiment is used to measure the effects of velocity-changing collisions between Kr* metastable atoms (4p55s[32]2) and He and Ar perturbers. Comparison between experimental profiles and profiles calculated assuming hard-sphere collisions between Kr* and perturber atoms confirms the calculations of Borenstein and Lamb concerning the change of velocity associated with a collision. Furthermore it is found that the rate of velocity-changing collisions is consistent with the predictions of kinetic theory.

C. Brechignac; R. Vetter; P. R. Berman

1978-05-01T23:59:59.000Z

292

Superluminal, subluminal, and negative velocities in free-space electromagnetic propagation  

E-Print Network (OSTI)

In this Chapter the time-domain analysis of the velocity of the electromagnetic field pulses generated by a spatially compact source in free space is presented. Recent simulations and measurements of anomalous superluminal, subluminal, and negative velocities are discussed. It is shown that such velocities are local and instantaneous in nature and do not violate either causality or special relativity. Although these effects are mainly confined to the near- and intermediate-field zones, some of them seem paradoxical and still lack adequate physical interpretation.

Budko, Neil V

2010-01-01T23:59:59.000Z

293

Precision measurement of transverse velocity distribution of a Strontium atomic beam  

E-Print Network (OSTI)

We measure precisely the transverse velocity distribution in a thermal Sr atomic beam with a velocity selective saturated fluorescence spectroscopy. By using the ultrastable laser system and narrow intercombination transition line of Sr atoms, the resolution of the velocity measured can be reached 0.13m/s, corresponding to 90$\\mu K$ in energy unit. The experimental results are agreement very well with a theoretical calculation. With the spectroscopic techniques, the absolute frequency of the intercombination transition of $^{88}$Sr is measured by an optical-frequency comb generator referenced to the SI second through an H maser, which is given by 434 829 121 318(10)kHz.

Gao, F; Xu, P; Tian, X; Wang, Y; Ren, J; Wu, Haibin; Chang, Hong

2013-01-01T23:59:59.000Z

294

Velocity width of the resonant domain in wave-particle interaction  

Science Journals Connector (OSTI)

Wave-particle interaction is a ubiquitous physical mechanism exhibiting locality in velocity space. A single-wave Hamiltonian provides a rich model by which to study the self-consistent interaction between one electrostatic wave and N quasiresonant particles. For the simplest nonintegrable Hamiltonian coupling two particles to one wave, we analytically derive the particle velocity borders separating quasi-integrable motions from chaotic ones. These estimates are fully retrieved through computation of the largest Lyapunov exponent. For the large-N particle self-consistent case, we numerically investigate the localization of stochasticity in velocity space and test a qualitative estimate of the borders of chaos.

Marie-Christine Firpo and Fabrice Doveil

2001-12-19T23:59:59.000Z

295

Groundwater velocities at the Nevada Test Site: {sup 14}Carbon-based estimates  

SciTech Connect

Chemical and isotopic data can be used to constrain and validate groundwater flow models. This study examines probable groundwater flowpaths at the Nevada Test Site (NTS) and estimates groundwater velocities for these flowpaths using water chemistry and carbon isotopes. These velocities are provided for comparison to velocities calculated by a numerical flow model developed by GeoTrans, Inc. Similar to numerical flow models, models of chemical and isotopic evolution are not unique; any number of combinations of reactions can simulate evolution from one water to another, but are no guarantee that the simulation is correct. Knowledge of the hydrology, mineralogy, and chemistry must be combined to produce feasible evolutionary paths.

Chapman, J.B.; Hershey, R.L.; Lyles, B.F.

1995-07-01T23:59:59.000Z

296

Design, fabrication, and characterization of germanium MOSFETs with high-k gate dielectric stacks based on the nitride interfacial layers  

E-Print Network (OSTI)

To improve source injection velocity, and consequently MOSFET performance, high mobility semiconductors are being explored as possible replacements for silicon. Germanium offers enhanced electron mobility and superior hole ...

Ritenour, Andrew P. (Andrew Paul), 1974-

2007-01-01T23:59:59.000Z

297

USING MICRO-SEISMICITY AND SEISMIC VELOCITIES TO MAP SUBSURFACE GEOLOGIC  

Open Energy Info (EERE)

USING MICRO-SEISMICITY AND SEISMIC VELOCITIES TO MAP SUBSURFACE GEOLOGIC USING MICRO-SEISMICITY AND SEISMIC VELOCITIES TO MAP SUBSURFACE GEOLOGIC AND HYDROLOGIC STRUCTURE WITHIN THE COSO GEOTHERMAL FIELD, CALIFORNIA Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: USING MICRO-SEISMICITY AND SEISMIC VELOCITIES TO MAP SUBSURFACE GEOLOGIC AND HYDROLOGIC STRUCTURE WITHIN THE COSO GEOTHERMAL FIELD, CALIFORNIA Details Activities (1) Areas (1) Regions (0) Abstract: We relocate 14 years of seismicity in the Coso Geothermal Field using differential travel times and simultaneously invert for seismic velocities to improve our knowledge of the subsurface geologic and hydrologic structure. We utilize over 60,000 micro-seismic events using waveform crosscorrelation to augment the expansive catalog of Pand S-wave

298

ARM - PI Product - Cloud-Scale Vertical Velocity and Turbulent Dissipation  

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

ProductsCloud-Scale Vertical Velocity and Turbulent ProductsCloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals Site(s) NSA General Description Time-height fields of retrieved in-cloud vertical wind velocity and turbulent dissipation rate, both retrieved primarily from vertically-pointing, Ka-band cloud radar measurements. Files are available for manually-selected, stratiform, mixed-phase cloud cases observed at the North Slope of Alaska (NSA) site during periods covering the Mixed-Phase Arctic Cloud Experiment (MPACE, late September through early November 2004) and the Indirect and Semi-Direct Aerosol Campaign (ISDAC, April-early May

299

ARM - PI Product - SGP and TWP (Manus) Ice Cloud Vertical Velocities  

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

ProductsSGP and TWP (Manus) Ice Cloud Vertical ProductsSGP and TWP (Manus) Ice Cloud Vertical Velocities Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : SGP and TWP (Manus) Ice Cloud Vertical Velocities 1997.01.01 - 2010.12.31 Site(s) SGP TWP General Description Daily netcdf-files of ice-cloud dynamics observed at the ARM sites at SGP (Jan1997-Dec2010) and Manus (Jul1999-Dec2010). The files include variables at different time resolution (10s, 20min, 1hr). Profiles of radar reflectivity factor (dbz), Doppler velocity (vel) as well as retrieved vertical air motion (V_air) and reflectivity-weighted particle terminal fall velocity (V_ter) are given at 10s, 20min and 1hr resolution. Lower level clouds are removed, however a multi-layer flag is included.

300

3-D seismic velocity and attenuation structures in the geothermal field  

SciTech Connect

We conducted delay time tomography to determine 3-D seismic velocity structures (Vp, Vs, and Vp/Vs ratio) using micro-seismic events in the geothermal field. The P-and S-wave arrival times of these micro-seismic events have been used as input for the tomographic inversion. Our preliminary seismic velocity results show that the subsurface condition of geothermal field can be fairly delineated the characteristic of reservoir. We then extended our understanding of the subsurface physical properties through determining of attenuation structures (Qp, Qs, and Qs/Qp ratio) using micro-seismic waveform. We combined seismic velocities and attenuation structures to get much better interpretation of the reservoir characteristic. Our preliminary attanuation structures results show reservoir characterization can be more clearly by using the 3-D attenuation model of Qp, Qs, and Qs/Qp ratio combined with 3-D seismic velocity model of Vp, Vs, and Vp/Vs ratio.

Nugraha, Andri Dian [Global Geophysics Research Group, Faculty of Mining and Petroleum Engineering, Institute of Technology Bandung, Jalan Ganesha No. 10 Bandung, 40132 (Indonesia)] [Global Geophysics Research Group, Faculty of Mining and Petroleum Engineering, Institute of Technology Bandung, Jalan Ganesha No. 10 Bandung, 40132 (Indonesia); Syahputra, Ahmad [Geophyisical Engineering, Faculty of Mining and Petroleum Engineering, Institute of Technology Bandung, Jalan Ganesha No. 10 Bandung, 40132 (Indonesia)] [Geophyisical Engineering, Faculty of Mining and Petroleum Engineering, Institute of Technology Bandung, Jalan Ganesha No. 10 Bandung, 40132 (Indonesia); Fatkhan,; Sule, Rachmat [Applied Geophysics Research Group, Faculty of Mining and Petroleum Engineering, Institute of Technology Bandung, Jalan Ganesha No. 10 Bandung, 40132 (Indonesia)] [Applied Geophysics Research Group, Faculty of Mining and Petroleum Engineering, Institute of Technology Bandung, Jalan Ganesha No. 10 Bandung, 40132 (Indonesia)

2013-09-09T23:59:59.000Z

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


301

An Exact Finite-Amplitude Wave on a Helmholtz Velocity Profile in an Infinite Boussinesq Fluid  

Science Journals Connector (OSTI)

For the Helmholtz velocity profile shown in Fig. 1, it is shown that the interface can support an exact steady finite-amplitude wave which radiates internal gravity waves away from the interface.

R. Grimshaw

1980-12-01T23:59:59.000Z

302

Effect of molecular solutes on the electron drift velocity in liquid Ar, Kr, and Xe  

Science Journals Connector (OSTI)

Measurements of the electron drift velocity in liquid argon, krypton, and xenon were performed in an electric field up to 100 kV cm-1. At higher field strengths saturation velocities were observed in agreement with other authors. The addition of a small concentration of molecular solutes leads to an increase of the electron drift velocity above the saturation value of the pure liquid. The drift velocity either reaches a higher constant value or passes through a maximum at field strengths greater than 104 V cm-1. This effect was investigated as a function of solute concentration for N2, H2, methane, ethane, propane, and butane. Inelastic energy losses in collisions of electrons and solute molecules are assumed and by means of the Cohen-Lekner theory the energy dependence of the loss processes is derived.

K. Yoshino; U. Sowada; W. F. Schmidt

1976-07-01T23:59:59.000Z

303

Shear wave seismic velocity profiling and depth to water table earthquake site  

E-Print Network (OSTI)

..................................................................................................... 6 Summary of seismic refraction/reflection methodsShear wave seismic velocity profiling and depth to water table ­ earthquake site response measurements for Valley County, Idaho Lee M. Liberty and Gabriel M. Gribler, Boise State University Center

Barrash, Warren

304

Stacking-velocity inversion with borehole constraints for tilted TI media Xiaoxiang Wang1  

E-Print Network (OSTI)

- ing an accurate anisotropic velocity model remains a challenging problem. For TI models, transverse isotropy with a tilted symmetry axis TTI is an ap- propriate model for dipping shale layers near

Tsvankin, Ilya

305

A Low-Velocity Zone in the Basement Beneath the Valles Caldera...  

Open Energy Info (EERE)

the Valles Caldera, New Mexico Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: A Low-Velocity Zone in the Basement Beneath the Valles Caldera,...

306

Blind Source Separation of Vibration Signal of Electric Motor Velocity Modulation System  

Science Journals Connector (OSTI)

Blind signal separation technique is the new one for array processing and data analysis. The research object of the paper is the complex and aliasing vibration signal measured from the AC electric motor velocity ...

Xiumei Li; Wen Li; Yannan Sun…

2011-01-01T23:59:59.000Z

307

Inversion for subbottom sound velocity profiles in the deep and shallow ocean  

E-Print Network (OSTI)

This thesis investigates the application of acoustic measurements in the deep and shallow ocean to infer the sound velocity profile (svp) in the seabed. For the deep water ocean, an exact method based on the Gelfand-Levitan ...

Souza, Luiz Alberto Lopes de

2005-01-01T23:59:59.000Z

308

The radial velocity signature of tides raised in stars hosting exoplanets  

E-Print Network (OSTI)

Close-in, massive exoplanets raise significant tides in their stellar hosts. We compute the radial velocity (RV) signal due to this fluid motion in the equilibrium tide approximation. The predicted RVs in the observed ...

Arras, Phil

309

Site-Specific Velocity and Density Model for the Waste Treatment Plant, Hanford, Washington.  

SciTech Connect

This report documents the work conducted under the SBP to develop a shear wave and compressional wave velocity and density model specific to the WTP site. Section 2 provides detailed background information on the WTP site and its underlying geology as well as on the Seismic Boreholes Project activities leading up to the Vs and Vp measurements. In Section 3, methods employed and results obtained are documented for measurements of Vs and Vp velocities in basalts and interbeds. Section 4 provides details on velocity measurements in the sediments underlying the WTP. Borehole gravity measurements of density of the subsurface basalt and sediments are described in Section 5. Section 6 describes the analysis of data presented in section 3-5, and presents the overall velocity and density model for the WTP site.

Rohay, Alan C.; Brouns, Thomas M.

2007-06-27T23:59:59.000Z

310

Statistics of pressure and of pressure-velocity correlations in isotropic turbulence  

E-Print Network (OSTI)

Some pressure and pressure-velocity correlation in a direct numerical simulations of a three-dimensional turbulent flow at moderate Reynolds numbers have been analyzed. We have identified a set of pressure-velocity correlations which posseses a good scaling behaviour. Such a class of pressure-velocity correlations are determined by looking at the energy-balance across any sub-volume of the flow. According to our analysis, pressure scaling is determined by the dimensional assumption that pressure behaves as a ``velocity squared'', unless finite-Reynolds effects are overwhelming. The SO(3) decompositions of pressure structure functions has also been applied in order to investigate anisotropic effects on the pressure scaling.

L. Biferale; P. Gualtieri; F. Toschi

2000-01-17T23:59:59.000Z

311

Influence of Shelves on Air Temperature and Velocity in a Supermarket  

E-Print Network (OSTI)

will be great. According to the analysis of measurement results of a supermarket in Harbin, factors such as relative position of supply and return air inlets, height of shelves and objects with heat generating capabilities influence the velocity fields...

Song, C.; Fang, X.; Tan, Y.

2006-01-01T23:59:59.000Z

312

E-Print Network 3.0 - annular systolic velocity Sample Search...  

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

<< < 1 2 3 4 5 > >> 1 Characterization of Mitral Valve Annular Dynamics in the Beating Heart MANUEL K. RAUSCH,1 Summary: the annular velocity as the temporal derivative of the...

313

Spectral characterization of Ekman velocities in the Southern Ocean based on surface drifter trajectories  

E-Print Network (OSTI)

that Period (days) Ocean Currents Power Spectral Density !2.2 Power rotary spectra of wind stress and ocean velocity2.2 Power rotary spectra of wind stress and ocean ve- locity

Elipot, Shane

2006-01-01T23:59:59.000Z

314

Crustal low-velocity zone south of Shatsky Rise, northwest Pacific Ocean  

Science Journals Connector (OSTI)

The detailed seismic refraction investigation of the oceanic crust south of Shatsky Rise in the Northwestern Pacific revealed a low velocity zone (LVZ) ... upwelling at the place of now “overdeepened” ocean would...

Gennady I. Anosov; Vladimir V. Argentov; Helios S. Gnibidenko

315

Calculation of the ion transverse velocity distribution function under ion cyclotron resonance heating  

Science Journals Connector (OSTI)

The ion transverse velocity distribution functions and the fraction ? of ions heated above a certain energy W 1 are calculated as applied to the ion cyclotron resonance heating method of isotope s...

A. I. Karchevskii; E. P. Potanin

2004-06-01T23:59:59.000Z

316

Effect of microbubble contrast on intracranial blood flow velocity assessed by transcranial Doppler  

Science Journals Connector (OSTI)

Ultrasound contrast agents (UCA) salvage a considerable number of transcranial Doppler (TCD) exams which would have failed ... measured blood flow velocity (BFV). The effect of UCA continuous infusion on measured...

Nicola Logallo; Annette Fromm; Ulrike Waje-Andreassen…

2014-03-01T23:59:59.000Z

317

Nuclear magnetic resonance measurements of velocity distributions in an ultrasonically vibrated granular bed  

Science Journals Connector (OSTI)

...Eakins, Fabrice Pierron and Clive Siviour Nuclear magnetic resonance measurements of velocity...Part 1) . We report the results of nuclear magnetic resonance imaging experiments...granular bed|ultrasonic fluidization|nuclear magnetic resonance|magnetic resonance...

2014-01-01T23:59:59.000Z

318

Energy cost and intracyclic variation of the velocity of the centre of mass in butterfly stroke  

Science Journals Connector (OSTI)

The purpose of this study was to examine the relationship between the intra-cycle variation of the horizontal velocity of displacement (dV) and the energy cost (EC) in butterfly stroke. Five Portuguese ... swim t...

Tiago M. Barbosa; K. L. Keskinen; R. Fernandes…

2005-03-01T23:59:59.000Z

319

QUIZ 2 A ball with mass 2 kg is thrown upward with initial velocity ...  

E-Print Network (OSTI)

A ball with mass 2 kg is thrown upward with initial velocity 100 m/s from the ground. Assume the air resistance is 0.2|v|. For simplicity, just assume that g = 10.

2014-09-24T23:59:59.000Z

320

Analytic theory for the determination of velocity and stability of bubbles in a Hele-Shaw cell  

Science Journals Connector (OSTI)

An asymptotic theory is presented for the determination of velocity and linear stability of a steady symmetric bubble in a Hele-Shaw cell for small ... surface tension. In the first part, the bubble velocity U re...

S. Tanveer

1989-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "high velocity sdhv" 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

Infrasonic?Noise Power Level and Wind?Velocity Correlation Study  

Science Journals Connector (OSTI)

Measurements of infrasonic?noise power and analyses of wind?velocity data were made. Correlation was found between infrasonic?noise power levels at a particular location and wind?velocity measurements taken at a distance of approximately 11 miles away. This information is useful for studying infrasonic?signal data improving the signal?to?noise ratio in physical measurements of infrasonic signals and for the selection of sites for infrasonic stations.

Howard S. Bowman

1965-01-01T23:59:59.000Z

322

Time dependent ellipsoidal residual velocity distributions for self-gravitating systems of collisionless particles  

E-Print Network (OSTI)

TIME DEPENDENT ELLIPSOIDAL RESIDUAL VELOCITY DISTRIBUTIONS FOR SELF-GRAVITATING SYSTEMS OF COLLISIONLESS PARTICLES A Thesis by FRANK ROBERT SINS Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE May 1973 Major Subject: Physi cs TIME DEPENDENT ELLIPSOIDAL RESIDUAL VELOCITY DISTRIBUTIONS FOR SELF-GRAVITATING SYSTEMS OF COLLISIONLESS PARTICLES A Thesis by FRANK ROBERT SIMMS Approved as to style...

Simms, Frank Robert

1973-01-01T23:59:59.000Z

323

Microbial Activity during Biodegradation and its Effects on Groundwater Velocity in a Contaminated Aquifer  

E-Print Network (OSTI)

, toluene, ethylbenzene, and xylene isomers (BTEX) (Yerushalmi et al., 1999; Landmeyer and Bradley 2003). Such passive methods rely on the ambient groundwater velocity to deliver contaminants to the reactive zone. Biostimulation techniques operate... Microbial Activity during Biodegradation and its Effects on Groundwater Velocity in a Contaminated Aquifer by Copyright 2008 Peter Curtis Schillig B.S. (Dept. Hons), Ohio University, 2005 Submitted to the Department...

Schillig, Peter C.

2008-03-26T23:59:59.000Z

324

The development of a low velocity wind tunnel with instrumentation for boundary layer investigations  

E-Print Network (OSTI)

THE DEVELOPMENT OF A LOW VELOCITY WIND TUNNEL WITH INSTRUMENTATION FOR BOUNDARY LAYER INVESTIGATIONS A Dissertation B y John Robert Massey Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial... fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY May 1958 Major Subject: Mechanical Engineering THE DEVELOPMENT OF A LOW VELOCITY WIND TUNNEL WITH INSTRUMENTATION FOR BOUNDARY LAYER INVESTIGATIONS A Dissertation By John Robert...

Massey, John Robert

2013-10-04T23:59:59.000Z

325

Radial velocities from VLT-KMOS spectra of giant stars in the globular cluster NGC 6388  

E-Print Network (OSTI)

We present new radial velocity measurements for 82 stars, members of the Galactic globular cluster NGC 6388, obtained from ESO-VLT KMOS spectra acquired during the instrument Science Verification. The accuracy of the wavelength calibration is discussed and a number of tests of the KMOS response are presented. The cluster systemic velocity obtained (81.3 +/- 1.5 km/sec) is in very good agreement with previous determinations. While a hint of ordered rotation is found between 9'' and 20'' from the cluster centre, where the distribution of radial velocities is clearly bimodal, more data are needed before drawing any firm conclusions. The acquired sample of radial velocities has been also used to determine the cluster velocity dispersion profile between ~9'' and 70'', supplementing previous measurements at r 60'' obtained with ESO-SINFONI and ESO-FLAMES spectroscopy, respectively. The new portion of the velocity dispersion profile nicely matches the previous ones, better defining the knee of the distribution. The...

Lapenna, Emilio; Mucciarelli, Alessio; Lanzoni, Barbara; Ferraro, Francesco Rosario; Dalessandro, Emanuele; Valenti, Elena; Cirasuolo, Michele

2014-01-01T23:59:59.000Z

326

A study of vacuum arc ion velocities using a linear set of probes  

SciTech Connect

The most likely velocity of ions moving away from vacuum arc cathode spots was measured using a set of probes along the path of plasma expansion. The goal was to determine how much, if any, change of the ion drift velocity occurs in the expanded plasma. The arc discharge current was perturbed to create plasma density markers whose travel is picked up by the set of probes. It was found that the perturbation with current oscillations did not result in consistent data because ion current maxima and minima are not only determined by the plasma production but by the transients of the arc pulse and by the asymmetry of the ion velocity distribution function. Perturbation with a short current spike was more conclusive. The ion velocity was measured to be slightly reduced with increasing distance from the cathode, which can be explained by collisions of ions with the background of neutrals. The ion velocity was increased when the arc current was increased, which correlated with enhanced arc voltage and power dissipation. The ion velocity could be enhanced when the plasma was produced in a non-uniform magnetic field.

Hohenbild, Stefan; Grubel, Christoph; Yushkov, Georgy Yu.; Oks, Efim M.; Anders, Andre

2008-07-15T23:59:59.000Z

327

Raindrop axis ratios, fall velocities and size distribution over Sumatra from 2D-Video Disdrometer measurement  

Science Journals Connector (OSTI)

Raindrop axis ratio, falling velocity and size distribution are important in broad list of applications. However, they are not frequently observed in the equatorial region. This paper elucidated the characteristics of raindrop axis ratio, falling velocity and size distribution based on 2D-Video Disdrometer (2DVD) data that have been collected in the equatorial Indonesia, particularly at Kototabang (hereafter called KT), west Sumatra, Indonesia (0.20°S, 100.32°E, 864 m above sea level). A comprehensive follow-up of the previous study on the natural variability of raindrop size distributions (DSDs) is presented. Precipitation was classified through 1.3-GHz wind profiler observation. The dependence of raindrop falling velocity and axis ratio on rainfall type was not clearly observed. Overall, measured raindrop fall velocities were in good agreement with Gunn–Kinzer's data. Raindrop axis ratio at KT was more spherical than that of artificial rain and equilibrium model, and close to the values reported in the turbulent high shear zone of surface layer which can be partially due to the effect of the instrument errors (e.g., location and container shape). Of some natural variations of DSD investigated, the dependence of DSD on rainfall rate and rainfall type as well as diurnal variation was clearly visible. A striking contrast between the stratiform and convective rains is that the size distributions from the stratiform (convective) rains tend to narrow (broaden) with increasing rainfall rates. For rainfall rate R < 10 mm/h, the size distribution of stratiform was broader than that of convective. On the other hand, at higher rainfall rate more large-sized drops were found in convective rain. During the convective rain, very large-sized drops were found mainly at the very start of rain event while for the stratiform they were found to be associated with a strong bright band. In diurnal basis, the \\{DSDs\\} in the morning hours were narrower than those in the evening which was indicated by smaller Dm values in the morning hours than their counterparts in the evening. Rainfall type dependence and diurnal variation of DSD lead to significant variation of Z–R relations so that they must be considered to increase the accuracy of Z–R conversion from weather radar in this region. Consistent with the previous study, lack of seasonal DSD variability was also found in this work that would be due to significant local convective and orographic effect at this region throughout the year. However, Dm values in our result were larger than the typical orographic DSD.

Marzuki; Walter L. Randeu; Toshiaki Kozu; Toyoshi Shimomai; Hiroyuki Hashiguchi; Michael Schönhuber

2013-01-01T23:59:59.000Z

328

Compressional and shear-wave velocities from gas hydrate bearing sediments: Examples from the India and Cascadia margins as well as Arctic permafrost regions  

Science Journals Connector (OSTI)

Abstract Shear wave velocity data have been acquired at several marine gas hydrate drilling expeditions, including the India National Gas Hydrate Program Expedition 1 (NGHP-01), the Ocean Drilling Program (ODP) Leg 204, and Integrated Ocean Drilling Program (IODP) Expedition 311 (X311). In this study we use data from these marine drilling expeditions to develop an understanding of general grain-size control on the P- and S-wave properties of sediments. A clear difference in the downhole trends of P-wave (Vp) and S-wave (Vs) velocity and the Vp/Vs ratio from all three marine regions was observed: the northern Cascadia margin (IODP X311) shows the highest P-wave and S-wave velocity values overall and those from the India margin (Expedition NGHP-01) are the lowest. The southern Cascadia margin (ODP Leg 204) appears to have similar low P-wave and S-wave velocity values as seen off India. S-wave velocity values increase relative to the sites off India, but they are not as high as those seen on the northern Cascadia margin. Such regional differences can be explained by the amount of silt/sand (or lack thereof) occurring at these sites, with northern Cascadia being the region of the highest silt/sand occurrences. This grain-size control on P-wave and S-wave velocity and associated mineral composition differences is amplified when compared to the Arctic permafrost environments, where gas hydrate predominantly occurs in sand- and silt-dominated formations. Using a cross-plot of gamma ray values versus the Vp/Vs ratio, we compare the marine gas hydrate occurrences in these regions: offshore eastern India margin, offshore Cascadia margin, the Ignik-Sikumi site in Alaska, and the Mallik 5L-38 site in the Mackenzie Delta. The log-data from the Arctic permafrost regions show a strongly linear Vp–Vs relationship, similar to the previously defined empirical relationships by Greenberg and Castagna (1992). P- and S-wave velocity data from the India margin and ODP Leg 204 deviate strongly from these linear trends, whereas data from IODP X311 plot closer to the trend of the Arctic data sets and previously published relationships. Three new linear relationships for different grain size marine sediment hosts are suggested:a) mud-dominated (Mahanadi Basin, ODP Leg 204 & NGHP-01-17): Vs = 1.5854 × Vp ? 2.1649 b) silty-mud (KG Basin): Vs = 0.8105 × Vp ? 1.0223 c) silty-sand (IODP X311): Vs = 0.5316 × Vp ? 0.4916 We investigate the relationship of gas hydrate saturation determined from electrical resistivity on the Vp/Vs ratio and found that the sand-dominated Arctic hosts show a clearly decreasing trend of Vp/Vs ratio with gas hydrate saturation. Though limited due to lower overall GH saturations, a similar trend is seen for sites from IODP X311 and at the ash-dominated NGHP-01-17 sediment in the Andaman Sea. Gas hydrate that occurs predominantly in fractured clay hosts show a different trend where the Vp/Vs ratio is much higher than at sand-dominated sites and remains constant or increases slightly with increasing gas hydrate saturation. This trend may be the result of anisotropy in fracture-dominated systems, where P- and S-wave velocities appear higher and Archie-based saturations of gas hydrate are overestimated. Gas hydrate concentrations were also estimated in these three marine settings and at Arctic sites using an effective medium model, combining P- and S-wave velocities as equally weighted constraints on the calculation. The effective medium approach generally overestimates S-wave velocity in high-porosity, clay-dominated sediments, but can be accurately used in sand-rich formations.

M. Riedel; D. Goldberg; G. Guerin

2014-01-01T23:59:59.000Z

329

Velocity model-building by 3D frequency-domain, full-waveform inversion of wide-aperture seismic data  

E-Print Network (OSTI)

Velocity model-building by 3D frequency-domain, full-waveform inversion of wide-aperture seismic, any approach that helps to auto- mate and optimize velocity model-building will speed up the output . The most common approaches for building a PSDM velocity model rely on reflection traveltime tomography e

Vallée, Martin

330

ECG Denoising using Angular Velocity as a State and an Observation in an Extended Kalman Filter Framework  

E-Print Network (OSTI)

ECG Denoising using Angular Velocity as a State and an Observation in an Extended Kalman Filter of synthetic ECG signals. The proposed method considers the angular velocity of ECG signal, as one Terms-- Extended Kalman Filter (EKF), Angular velocity, Electrocardiogram (ECG), ECG Dynamical Model

Paris-Sud XI, Université de

331

Laminar burning velocity with oxygen-enriched air of syngas produced from biomass gasification  

Science Journals Connector (OSTI)

Abstract Several studies on the laminar burning velocity of syngas mixtures have been conducted by various researchers. However, in most of these studies, dry air was used as the oxidizer, whereas very few studies have been conducted on syngas combustion in oxygen – enriched air. In this work, a numerical and experimental study on the laminar burning velocity of a mixture of H2, CO and N2 (20:20:60 vol%) was performed using air enriched with oxygen as the oxidizer, varying the oxygen content from 21% up to 35% for different equivalence ratios. Numerical calculations were conducted using three detailed reaction mechanisms and transport properties. Flames were generated using contoured slot-type nozzle burners, and Schlieren images were used to determine the laminar burning velocity with the angle method. The experiments were performed under the conditions of Medellin (1550 m.a.s.l.), 0.838 atm and 298 K. The laminar burning velocity increases with the concentration of the oxygen in the mixture due to the increase of the reaction rate; for a stoichiometric mixture, the laminar burning velocity increases by almost 25% with an increment of 4% of oxygen in the oxidant. However, the flammability limits also increase, allowing stable flames to exist in a wider range of equivalence ratios.

Hernando A. Yepes; Andres A. Amell

2013-01-01T23:59:59.000Z

332

Laser-optic Measurements of Velocity of Particles in the Powder Stream at Coaxial Laser Cladding  

Science Journals Connector (OSTI)

Abstract The problems of particle velocity and temperature measurement can be solved with commonly-known methods of registration based on spectrometry and a complex of laser and optical means. The diagnostic technique combines two independent methods of particle velocity measurement, namely the passive way which is based on the intrinsic radiation of the heated particles in a gas flow, and the active one which utilizes the effect of the laser beam scattering. It is demonstrated that the laser radiation can affect significantly the particles velocity at the laser cladding. Presented bar charts of statistical distributions of the particles velocities illustrate two modes of the coaxial nozzle performance, with and without ??2-laser radiation. Different types of powders (Al2O3, Mo, Ni, Al) were used in tests, the particle size distributions were typical for the laser cladding; air, nitrogen, argon were used as working gases, continuous radiation of the ??2 laser reached 3 kW. It is shown that in the laser-radiation field, the powder particles undergo extra acceleration due to the laser evaporation and reactive force occurrence resulting from the recoil pressure vapors from the beamed part of particles’ surfaces. The observed effect of particles acceleration depends on the particles concentration in the powder flow. Due to the laser acceleration, the velocities of individual particles may reach the values of about 80 – 100 m/s. The trichromatic pyrometry method was utilized to measure the particles temperature in the powder flow.

D.V. Sergachev; A.A. Mikhal’chenko; O.B. Kovalev; V.I. Kuz’min; G.N. Grachev; P.A. Pinaev

2014-01-01T23:59:59.000Z

333

Measurements of Outflow Velocities in On-Disk Plumes from EIS Hinode Observations  

E-Print Network (OSTI)

The contribution of plumes to the solar wind has been subject to hot debate in the past decades. The EUV Imaging Spectrometer (EIS) on board Hinode provides a unique means to deduce outflow velocities at coronal heights via direct Doppler shift measurements of coronal emission lines. Such direct Doppler shift measurements were not possible with previous spectrometers. We measure the outflow velocity at coronal heights in several on-disk long-duration plumes, which are located in coronal holes and show significant blue shifts throughout the entire observational period. In one case, a plume is measured 4 hours apart. The deduced outflow velocities are consistent, suggesting that the flows are quasi-steady. Furthermore, we provide an outflow velocity profile along the plumes, finding that the velocity corrected for the line-of-sight effect can reach 10 km s$^{-1}$ at 1.02 $R_{\\odot}$, 15 km s$^{-1}$ at 1.03 $R_{\\odot}$, and 25 km s$^{-1}$ at 1.05 $R_{\\odot}$. This clear signature of steady acceleration, combined...

Fu, Hui; Li, Bo; Huang, Zhenghua; Jiao, Fangran; Mou, Chaozhou

2014-01-01T23:59:59.000Z

334

Galaxy peculiar velocities from large-scale supernova surveys as a dark energy probe  

SciTech Connect

Upcoming imaging surveys such as the Large Synoptic Survey Telescope will repeatedly scan large areas of sky and have the potential to yield million-supernova catalogs. Type Ia supernovae are excellent standard candles and will provide distance measures that suffice to detect mean pairwise velocities of their host galaxies. We show that when combining these distance measures with photometric redshifts for either the supernovae or their host galaxies, the mean pairwise velocities of the host galaxies will provide a dark energy probe which is competitive with other widely discussed methods. Adding information from this test to type Ia supernova photometric luminosity distances from the same experiment, plus the cosmic microwave background power spectrum from the Planck satellite, improves the Dark Energy Task Force figure of merit by a factor of 1.8. Pairwise velocity measurements require no additional observational effort beyond that required to perform the traditional supernova luminosity distance test, but may provide complementary constraints on dark energy parameters and the nature of gravity. Incorporating additional spectroscopic redshift follow-up observations could provide important dark energy constraints from pairwise velocities alone. Mean pairwise velocities are much less sensitive to systematic redshift errors than the luminosity distance test or weak lensing techniques, and also are only mildly affected by systematic evolution of supernova luminosity.

Bhattacharya, Suman; Kosowsky, Arthur; Newman, Jeffrey A.; Zentner, Andrew R. [T-2, Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States)

2011-02-15T23:59:59.000Z

335

Enrichment of the dust-to-gas mass ratio in Bondi/Jeans accretion/cloud systems due to unequal changes in dust and gas incoming velocities  

E-Print Network (OSTI)

The ratio of the Bondi and Jeans lengths is used to develop a cloud-accretion model that describes both an inner Bondi-type regime where gas pressure is balanced by the gravity of a central star and an outer Jeans-type regime where gas pressure is balanced by gas self-gravity. The gas density profile provided by this model makes a smooth transition from a wind-type inner solution to a Bonnor-Ebert type outer solution. It is shown that high-velocity dust impinging on this cloud will tend to pile-up due to having a different velocity profile than gas so that the dust-to-gas ratio is substantially enriched above the 1% ISM level.

P. M. Bellan

2008-01-27T23:59:59.000Z

336

Controlling the velocity of jumping nanodroplets via their initial shape and temperature  

SciTech Connect

Controlling the movement of nanoscale objects is a significant goal of nanotechnology. Dewetting-induced ejection of nanodroplets could provide another means of achieving that goal. Molecular dynamics simulations were used to investigate the dewetting-induced ejection of nanoscale liquid copper nanostructures that were deposited on a graphitic substrate. Nanostructures in the shape of a circle, square, equilateral, and isosceles triangle dewet and form nanodroplets that are ejected from the substrate with a velocity that depends on the initial shape and temperature. The dependence of the ejected velocity on shape is ascribed to the temporal asymmetry of the mass coalescence during the droplet formation; the dependence on temperature is ascribed to changes in the density and viscosity. The results suggest that dewetting induced by nanosecond laser pulses could be used to control the velocity of ejected nanodroplets.

Fuentes-Cabrera, Miguel A [ORNL; Rhodes, Bradley H [ORNL; Baskes, Mike I. [Los Alamos National Laboratory (LANL); Terrones Maldonado, Humberto [ORNL; Fowlkes, Jason Davidson [ORNL; Simpson, Michael L [ORNL; Rack, Philip D [ORNL

2011-01-01T23:59:59.000Z

337

Scattering polarization in the CaII Infrared Triplet with Velocity Gradients  

E-Print Network (OSTI)

Magnetic field topology, thermal structure and plasma motions are the three main factors affecting the polarization signals used to understand our star. In this theoretical investigation, we focus on the effect that gradients in the macroscopic vertical velocity field have on the non-magnetic scattering polarization signals, establishing the basis for general cases. We demonstrate that the solar plasma velocity gradients have a significant effect on the linear polarization produced by scattering in chromospheric spectral lines. In particular, we show the impact of velocity gradients on the anisotropy of the radiation field and on the ensuing fractional alignment of the CaII levels, and how they can lead to an enhancement of the zero-field linear polarization signals. This investigation remarks the importance of knowing the dynamical state of the solar atmosphere in order to correctly interpret spectropolarimetric measurements, which is important, among other things, for establishing a suitable zero field refe...

Carlin, E S; Ramos, A Asensio; Bueno, J Trujillo

2012-01-01T23:59:59.000Z

338

Determination of simple constitutive models for borosilicate glass using penetration-velocity data from ballistic experiments  

SciTech Connect

Constitutive models for brittle materials such as glass can be very complex as they are dependent on strains, strain rates, pressures, temperatures, damage and other parameters. There may also be significant (pressure-dependent) strength after failure such that the constitutive response is much different for intact material and failed material. A large number of laboratory tests is required to develop a comprehensive constitutive model. Another approach is to develop simple models by using penetration-velocity data obtained from ballistic experiments. Here various functional forms of simple models (with a limited number of constants) can be used to (computationally) match the penetration velocity over a range of impact velocities. This allows for the determination of the most important parameters and it provides an approximation of the stresses that occur during penetration. This article presents several simple computational models for borosilicate glass, including single-state models and dual-state models (that include an intact strength and a failed strength)

Johnson, G. R.; Holmquist, T. J. [Southwest Research Institute, 5353 Wayzata Blvd., Minneapolis, MN 55416 (United States)

2007-12-12T23:59:59.000Z

339

Precision measurement of transverse velocity distribution of a strontium atomic beam  

SciTech Connect

We measure the transverse velocity distribution in a thermal Sr atomic beam precisely by velocity-selective saturated fluorescence spectroscopy. The use of an ultrastable laser system and the narrow intercombination transition line of Sr atoms mean that the resolution of the measured velocity can reach 0.13 m/s, corresponding to 90 ?K in energy units. The experimental results are in very good agreement with the results of theoretical calculations. Based on the spectroscopic techniques used here, the absolute frequency of the intercombination transition of {sup 88}Sr is measured using an optical-frequency comb generator referenced to the SI second through an H maser, and is given as 434 829 121 318(10) kHz.

Gao, F.; Liu, H.; Tian, X. [CAS Key Laboratory of Time and Frequency Primary Standards, National Time Service Center, Xi'an 710600 (China) [CAS Key Laboratory of Time and Frequency Primary Standards, National Time Service Center, Xi'an 710600 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Xu, P.; Wang, Y.; Ren, J. [CAS Key Laboratory of Time and Frequency Primary Standards, National Time Service Center, Xi'an 710600 (China)] [CAS Key Laboratory of Time and Frequency Primary Standards, National Time Service Center, Xi'an 710600 (China); Wu, Haibin, E-mail: hbwu@phy.ecnu.edu.cn [State Key Laboratory of Precision Spectroscopy, Department of Physics, East China Normal University, Shanghai 200062 (China)] [State Key Laboratory of Precision Spectroscopy, Department of Physics, East China Normal University, Shanghai 200062 (China); Chang, Hong, E-mail: changhong@ntsc.ac.cn [CAS Key Laboratory of Time and Frequency Primary Standards, National Time Service Center, Xi'an 710600 (China) [CAS Key Laboratory of Time and Frequency Primary Standards, National Time Service Center, Xi'an 710600 (China); State Key Laboratory of Precision Spectroscopy, Department of Physics, East China Normal University, Shanghai 200062 (China)

2014-02-15T23:59:59.000Z

340

On the role of spectral resolution in velocity shear layer measurements by Doppler reflectometry  

SciTech Connect

The signal quality of a Doppler reflectometer depends strongly on its spectral resolution, which is influenced by the microwave beam properties and the radius of curvature of the cutoff layer in the plasma. If measured close to a strong perpendicular velocity shear layer, the spectrum of the backscattered signal is influenced by different velocities. This can give rise to two Doppler shifted peaks in the spectrum as observed in TJ-II H-mode plasmas. It is shown by two-dimensional full wave simulations that the two peaks are separable provided the spectral resolution of the system is sufficient. However, if the spectral resolution is poor, the two peaks blend into one and yield an intermediate and incorrect velocity.

Happel, T.; Blanco, E.; Estrada, T. [Laboratorio Nacional de Fusion, Association Euratom-Ciemat, 28040 Madrid (Spain)

2010-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "high velocity sdhv" 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

RADIAL VELOCITIES OF GALACTIC O-TYPE STARS. II. SINGLE-LINED SPECTROSCOPIC BINARIES  

SciTech Connect

We report on new radial velocity measurements of massive stars that are either suspected binaries or lacking prior observations. This is part of a survey to identify and characterize spectroscopic binaries among O-type stars with the goal of comparing the binary fraction of field and runaway stars with those in clusters and associations. We present orbits for HDE 308813, HD 152147, HD 164536, BD-16 Degree-Sign 4826, and HDE 229232, Galactic O-type stars exhibiting single-lined spectroscopic variation. By fitting model spectra to our observed spectra, we obtain estimates for effective temperature, surface gravity, and rotational velocity. We compute orbital periods and velocity semiamplitudes for each system and note the lack of photometric variation for any system. These binaries probably appear single-lined because the companions are faint and because their orbital Doppler shifts are small compared to the width of the rotationally broadened lines of the primary.

Williams, S. J.; Gies, D. R. [Center for High Angular Resolution Astronomy and Department of Physics and Astronomy, Georgia State University, P.O. Box 4106, Atlanta, GA 30302-4106 (United States); Hillwig, T. C. [Department of Physics and Astronomy, Valparaiso University, Valparaiso, IN 46383 (United States); McSwain, M. V. [Department of Physics, Lehigh University, 16 Memorial Drive East, Bethlehem, PA 18015 (United States); Huang, W., E-mail: swilliams@chara.gsu.edu, E-mail: gies@chara.gsu.edu, E-mail: todd.hillwig@valpo.edu, E-mail: mcswain@lehigh.edu, E-mail: hwenjin@astro.washington.edu [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195-1580 (United States)

2013-02-01T23:59:59.000Z

342

Doppler cooling with coherent trains of laser pulses and a tunable velocity comb  

SciTech Connect

We explore the possibility of decelerating and Doppler cooling an ensemble of two-level atoms by a coherent train of short, nonoverlapping laser pulses. We derive analytical expressions for mechanical force exerted by the train. In frequency space the force pattern reflects the underlying frequency comb structure. The pattern depends strongly on the ratio of the atomic lifetime to the repetition time between the pulses and pulse area. For example, in the limit of short lifetimes, the frequency-space peaks of the optical force wash out. We propose to tune the carrier-envelope offset frequency to follow the Doppler-shifted detuning as atoms decelerate; this leads to compression of atomic velocity distribution about comb teeth and results in a ''velocity comb''--a series of narrow equidistant peaks in the velocity space.

Ilinova, Ekaterina; Ahmad, Mahmoud; Derevianko, Andrei [Department of Physics, University of Nevada, Reno, Nevada 89557 (United States)

2011-09-15T23:59:59.000Z

343

The {ital b} Distribution and the Velocity Structure of Absorption Peaks in the Ly{alpha} Forest  

SciTech Connect

A theory is developed that relates the observed {ital b} parameter of a Ly{alpha} absorption line to the velocity curvature of the corresponding peak in the optical depth fluctuation. Its relation to the traditional interpretation of {ital b} as the thermal broadening width is discussed. It is demonstrated that, independent of the details of the cosmological model, the differential {ital b} distribution has a high-{ital b} asymptote of dN/db{proportional_to}b{sup {minus}m}, where m{ge}5, when we make the reasonable assumption that low-curvature fluctuations are statistically favored over high-curvature ones. There in general always exist lines much broader than the thermal width. We develop a linear perturbative analysis of the optical depth fluctuation, which yields a single-parameter prediction for the full {ital b} distribution. In addition to exhibiting the high-velocity tail, it qualitatively explains the observed sharp low-{ital b} cutoff{emdash}a simple reflection of the fact that high-curvature fluctuations are relatively rare. Although the existence of the high-{ital b} asymptote, which is independent of the validity of the linear expansion, is consistent with the observed {ital b} distribution, a detailed comparison of the linear prediction with six observational data sets indicates that higher order corrections are not negligible. The perturbative analysis nonetheless offers valuable insights into the dependence of the {ital b} distribution on cosmological parameters such as {Omega} and the power spectrum. A key parameter is the effective smoothing scale of the optical depth fluctuation, which is in turn determined by three scales: the thermal broadening width, the baryon smoothing scale (approximately the Jeans scale), and the observation/simulation resolution. The first two are determined by reionization history, but are comparable in general, whereas the third varies by about an order of magnitude in current hydrodynamic simulations. Studies with non{endash}resolution-dominated {ital b} distributions can be used to probe the reionization history of the universe. {copyright} {ital {copyright} 1999.} {ital The American Astronomical Society}

Hui, L. [NASA/Fermilab Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States)] [NASA/Fermilab Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Rutledge, R.E. [Max-Planck-Institut fuer extraterrestrische Physik, Postfach 1603, D-85740 Garching (Germany)] [Max-Planck-Institut fuer extraterrestrische Physik, Postfach 1603, D-85740 Garching (Germany)

1999-06-01T23:59:59.000Z

344

The [ital b] Distribution and the Velocity Structure of Absorption Peaks in the Ly[alpha] Forest  

SciTech Connect

A theory is developed that relates the observed [ital b] parameter of a Ly[alpha] absorption line to the velocity curvature of the corresponding peak in the optical depth fluctuation. Its relation to the traditional interpretation of [ital b] as the thermal broadening width is discussed. It is demonstrated that, independent of the details of the cosmological model, the differential [ital b] distribution has a high-[ital b] asymptote of dN/db[proportional to]b[sup [minus]m], where m[ge]5, when we make the reasonable assumption that low-curvature fluctuations are statistically favored over high-curvature ones. There in general always exist lines much broader than the thermal width. We develop a linear perturbative analysis of the optical depth fluctuation, which yields a single-parameter prediction for the full [ital b] distribution. In addition to exhibiting the high-velocity tail, it qualitatively explains the observed sharp low-[ital b] cutoff[emdash]a simple reflection of the fact that high-curvature fluctuations are relatively rare. Although the existence of the high-[ital b] asymptote, which is independent of the validity of the linear expansion, is consistent with the observed [ital b] distribution, a detailed comparison of the linear prediction with six observational data sets indicates that higher order corrections are not negligible. The perturbative analysis nonetheless offers valuable insights into the dependence of the [ital b] distribution on cosmological parameters such as [Omega] and the power spectrum. A key parameter is the effective smoothing scale of the optical depth fluctuation, which is in turn determined by three scales: the thermal broadening width, the baryon smoothing scale (approximately the Jeans scale), and the observation/simulation resolution. The first two are determined by reionization history, but are comparable in general, whereas the third varies by about an order of magnitude in current hydrodynamic simulations. Studies with non[endash]resolution-dominated [ital b] distributions can be used to probe the reionization history of the universe. [copyright] [ital [copyright] 1999.] [ital The American Astronomical Society

Hui, L. (NASA/Fermilab Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States)); Rutledge, R.E. (Max-Planck-Institut fuer extraterrestrische Physik, Postfach 1603, D-85740 Garching (Germany))

1999-06-01T23:59:59.000Z

345

Determination of Non-thermal Velocity Distributions from SERTS Linewidth Observations  

Science Journals Connector (OSTI)

Non-thermal velocities obtained from the measurement of coronal Extreme Ultraviolet (EUV) linewidths have been consistently observed in solar EUV spectral observations and have been theorized to result from many plausible scenarios including wave motions, turbulence, or magnetic reconnection. Constraining these velocities can provide a physical limit for the available energy resulting from unresolved motions in the corona. We statistically determine a series of non-thermal velocity distributions from linewidth measurements of 390 emission lines from a wide array of elements and ionization states observed during the Solar Extreme Ultraviolet Research Telescope and Spectrograph 1991-1997 flights covering the spectral range 174-418 Å and a temperature range from 80,000 K to 12.6 MK. This sample includes 248 lines from active regions, 101 lines from quiet-Sun regions, and 41 lines were observed from plasma off the solar limb. We find a strongly peaked distribution corresponding to a non-thermal velocity of 19-22 km s–1 in all three of the quiet-Sun, active region, and off-limb distributions. For the possibility of Alfvén wave resonance heating, we find that velocities in the core of these distributions do not provide sufficient energy, given typical densities and magnetic field strengths for the coronal plasma, to overcome the estimated coronal energy losses required to maintain the corona at the typical temperatures working as the sole mechanism. We find that at perfect efficiency 50%-60% of the needed energy flux can be produced from the non-thermal velocities measured.

Aaron J. Coyner; Joseph M. Davila

2011-01-01T23:59:59.000Z

346

DETERMINATION OF NON-THERMAL VELOCITY DISTRIBUTIONS FROM SERTS LINEWIDTH OBSERVATIONS  

SciTech Connect

Non-thermal velocities obtained from the measurement of coronal Extreme Ultraviolet (EUV) linewidths have been consistently observed in solar EUV spectral observations and have been theorized to result from many plausible scenarios including wave motions, turbulence, or magnetic reconnection. Constraining these velocities can provide a physical limit for the available energy resulting from unresolved motions in the corona. We statistically determine a series of non-thermal velocity distributions from linewidth measurements of 390 emission lines from a wide array of elements and ionization states observed during the Solar Extreme Ultraviolet Research Telescope and Spectrograph 1991-1997 flights covering the spectral range 174-418 A and a temperature range from 80,000 K to 12.6 MK. This sample includes 248 lines from active regions, 101 lines from quiet-Sun regions, and 41 lines were observed from plasma off the solar limb. We find a strongly peaked distribution corresponding to a non-thermal velocity of 19-22 km s{sup -1} in all three of the quiet-Sun, active region, and off-limb distributions. For the possibility of Alfven wave resonance heating, we find that velocities in the core of these distributions do not provide sufficient energy, given typical densities and magnetic field strengths for the coronal plasma, to overcome the estimated coronal energy losses required to maintain the corona at the typical temperatures working as the sole mechanism. We find that at perfect efficiency 50%-60% of the needed energy flux can be produced from the non-thermal velocities measured.

Coyner, Aaron J. [Department of Physics, Catholic University of America, 620 Michigan Avenue, Washington, DC 20064 (United States); Davila, Joseph M., E-mail: aaron.j.coyner@nasa.gov [Code 671, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2011-12-01T23:59:59.000Z

347

The in situ permeable flow sensor: A device for measuring groundwater flow velocity  

SciTech Connect

A new technology called the In Situ Permeable Flow Sensor has been developed at Sandia National Laboratories. These sensors use a thermal perturbation technique to directly measure the direction and magnitude of the full three dimensional groundwater flow velocity vector in unconsolidated, saturated, porous media. The velocity measured is an average value characteristic of an approximately 1 cubic meter volume of the subsurface. During a test at the Savannah River Site in South Carolina, two flow sensors were deployed in a confined aquifer in close proximity to a well which was screened over the entire vertical extent of the aquifer and the well was pumped at four different pumping rates. In this situation horizontal flow which is radially directed toward the pumping well is expected. The flow sensors measured horizontal flow which was directed toward the pumping well, within the uncertainty in the measurements. The observed magnitude of the horizontal component of the flow velocity increased linearly with pumping rate, as predicted by theoretical considerations. The measured horizontal component of the flow velocity differed from the predicted flow velocity, which was calculated with the assumptions that the hydraulic properties of the aquifer were radially homogeneous and isotropic, by less than a factor of two. Drawdown data obtained from other wells near the pumping well during the pump test indicate that the hydraulic properties of the aquifer are probably not radially homogeneous but the effect of the inhomogeneity on the flow velocity field around the pumping well was not modeled because the degree and distribution of the inhomogeneity are unknown. Grain size analysis of core samples from wells in the area were used to estimate the vertical distribution of hydraulic conductivity.

Ballard, S.; Barker, G.T. [Sandia National Labs., Albuquerque, NM (United States); Nichols, R.L. [Savannah River Technology Center, Aiken, SC (United States)

1994-03-01T23:59:59.000Z

348

Using the Heterodyne Method to Measure Velocities on Shock Physics Experiments  

SciTech Connect

We developed a velocimeter system several years ago that uses the heterodyne method [1]. This system is assembled from commercially available components that were developed for the telecommunications industry. There are several advantages of this system over the traditional VISAR method that has made it increasingly popular. This system is compact, portable, and relatively inexpensive. The maximum velocity of this system is determined by the electrical bandwidth of the electronics and the digitizer sample rate. The maximum velocity for the system described here is over 5 km/s.

Strand, O T; Whitworth, T L

2007-08-10T23:59:59.000Z

349

Using the heterodyne method to measure velocities on shock physics experiments  

SciTech Connect

We developed a velocimeter system several years ago that uses the heterodyne method [1]. This system is assembled from commercially available components that were developed for the telecommunications industry. There are several advantages of this system over the traditional VISAR method that has made it increasingly popular. This system is compact, portable, and relatively inexpensive. The maximum velocity of this system is determined by the electrical bandwidth of the electronics and the digitizer sample rate. The maximum velocity for the system described here is over 5 km/s.

Strand, Oliver T.; Whitworth, Tony L. [Lawrence Livermore National Laboratory, Livermore, CA (United States)

2007-12-12T23:59:59.000Z

350

A model of the near-surface seismic velocity: southern San Joaqin Valley, California  

E-Print Network (OSTI)

at velocity-survey locations during this time perh&d. Afore recent crater-table data consist of hydr?graph plot~ supplied by I'enneco %Vest, formerly the Kern County Land Company. These plots show water-table depths measured semi-annually during the period..., ''1; as a. function of D??/D, . From a representative set of test data, traveltime-versus-depth and water-table-depth measurements &vere plotted to determine these parameters (Figure 3). According to this plot, the velocity (la) in the layer above...

Ferry, James Gerard

2012-06-07T23:59:59.000Z

351

Phase-Resolved Measurements of Ion Velocity in a Radio-Frequency Sheath  

SciTech Connect

The time-dependent argon-ion velocity distribution function above and within the plasma sheath of an rf-biased substrate has been measured using laser-induced fluorescence in a commercial plasma processing tool. Discharge parameters were such that the 2.2 MHz rf-bias period was on the order of the ion transit time through the sheath ({tau}{sub ion}/{tau}{sub rf}=0.3). This work embodies the first time-resolved measurement of ion velocity distribution functions within an rf-biased sheath over a large area (30 cm diameter) silicon wafer substrate.

Jacobs, Brett; Gekelman, Walter; Pribyl, Pat [Department of Physics and Astronomy, University of California--Los Angeles, Los Angeles, California 90024 (United States); Barnes, Michael [MS Barnes Engineering, San Ramon, California 94583 (United States)

2010-08-13T23:59:59.000Z

352

High temperature probe  

DOE Patents (OSTI)

A high temperature probe for sampling, for example, smokestack fumes, and is able to withstand temperatures of 3000.degree. F. The probe is constructed so as to prevent leakage via the seal by placing the seal inside the water jacket whereby the seal is not exposed to high temperature, which destroys the seal. The sample inlet of the probe is also provided with cooling fins about the area of the seal to provide additional cooling to prevent the seal from being destroyed. Also, a heated jacket is provided for maintaining the temperature of the gas being tested as it passes through the probe. The probe includes pressure sensing means for determining the flow velocity of an efficient being sampled. In addition, thermocouples are located in various places on the probe to monitor the temperature of the gas passing there through.

Swan, Raymond A. (Fremont, CA)

1994-01-01T23:59:59.000Z

353

Property:Current Velocity Range(m/s) | Open Energy Information  

Open Energy Info (EERE)

Velocity Range(m/s) Velocity Range(m/s) Jump to: navigation, search Property Name Current Velocity Range(m/s) Property Type String Pages using the property "Current Velocity Range(m/s)" Showing 25 pages using this property. (previous 25) (next 25) 1 1.5-ft Wave Flume Facility + 0.0 + 10-ft Wave Flume Facility + 0.0 + 11-ft Wave Flume Facility + 0.0 + 2 2-ft Flume Facility + 0.0 + 3 3-ft Wave Flume Facility + 0.0 + 5 5-ft Wave Flume Facility + 0.0 + 6 6-ft Wave Flume Facility + 0.0 + A Alden Large Flume + 3.2 + Alden Small Flume + 0.0 + Alden Wave Basin + 0.0 + B Breakwater Research Facility + 0.0 + C Carderock Maneuvering & Seakeeping Basin + 0.0 + Carderock Tow Tank 2 + 0.0 + Carderock Tow Tank 3 + 0.0 + Chase Tow Tank + 0.0 + Coastal Harbors Modeling Facility + 0.0 +

354

Two-Phase Isentropic Compressibility and Two-Phase Sonic Velocity for  

E-Print Network (OSTI)

and sonic velocity are used for a wide range of problems in the production and exploration of hydrocarbon in well testing, metering, and seismic exploration. In this work, a thermo- dynamic model is presented defined on the basis of the thermody- namic path. For an isothermal process, the compressibility relates

Firoozabadi, Abbas

355

Neoproterozoic tectonothermal evolution of the Central Eastern Desert, Egypt: a slow velocity tectonic process  

E-Print Network (OSTI)

Neoproterozoic tectonothermal evolution of the Central Eastern Desert, Egypt: a slow velocity, University of Assiut, Egypt Received 10 January 2001; received in revised form 24 October 2001; accepted 25 in the Central Eastern Desert of Egypt is constraint by 40 Ar/39 Ar ages of hornblende and muscovite from Meatiq

Fritz, Harald

356

Kinematic deprojection and mass inversion of spherical systems of known velocity anisotropy  

Science Journals Connector (OSTI)

......models with the first four of these anisotropy...than 70 per cent (in four cases out of five...practical means to lift the mass-anisotropy...velocity field at each point, or else its moments...except at the innermost point where the mass is...10 per cent in the four anisotropy models......

Gary A. Mamon; Gwenaël Boué

2010-02-01T23:59:59.000Z

357

Lithospheric Velocity Structure of the Anatolain plateau-Caucasus-Caspian Regions  

SciTech Connect

Anatolian Plateau-Caucasus-Caspian region is an area of complex structure accompanied by large variations in seismic wave velocities. Despite the complexity of the region little is known about the detailed lithospheric structure. Using data from 29 new broadband seismic stations in the region, a unified velocity structure is developed using teleseismic receiver functions and surface waves. Love and Rayleigh surface waves dispersion curves have been derived from event-based analysis and ambient-noise correlation. We jointly inverted the receiver functions with the surface wave dispersion curves to determine absolute shear wave velocity and important discontinuities such as sedimentary layer, Moho, lithospheric-asthenospheric boundary. We combined these new station results with Eastern Turkey Seismic Experiment results (29 stations). Caspian Sea and Kura basin underlained by one of the thickest sediments in the world. Therefore, short-period surface waves are observed to be very slow. The strong crustal multiples in receiver functions and the slow velocities in upper crust indicate the presence of thick sedimentary unit (up to 20 km). Crustal thickness varies from 34 to 52 km in the region. The thickest crust is in Lesser Caucasus and the thinnest is in the Arabian Plate. The lithospheric mantle in the Greater Caucasus and the Kura depression is faster than the Anatolian Plateau and Lesser Caucasus. This possibly indicates the presence of cold lithosphere. The lower crust is slowest in the northeastern part of the Anatolian Plateau where Holocene volcanoes are located.

Gok, R; Mellors, R J; Sandvol, E; Pasyanos, M; Hauk, T; Yetirmishli, G; Teoman, U; Turkelli, N; Godoladze, T; Javakishvirli, Z

2009-04-15T23:59:59.000Z

358

Average crack front velocity during subcritical fracture propagation in a heterogeneous medium  

E-Print Network (OSTI)

Average crack front velocity during subcritical fracture propagation in a heterogeneous medium relaxation tests, exploring subcritical to critical regimes. Transparency of the material (PMMA) allows kinetic crack propagation is usually referred to as sub-critical crack growth or sub- critical regime

Paris-Sud XI, Université de

359

Estimation of interval anisotropy parameters using velocity-independent layer stripping  

E-Print Network (OSTI)

by VILS in the shale layer above the reservoir are more plausible and less influenced by noise than those homogeneous VTI overburden. For 3D wide-azimuth data from layered azimuthally anisotropic media, the effective . Unfortunately, NMO velocity often is insufficient to build the ve- locity field for anisotropic media, even

Tsvankin, Ilya

360

Velocity Dependence of Baryon Screening in a Hot Strongly Coupled Plasma  

E-Print Network (OSTI)

The L-dependence of the static potential between Nc quarks arranged in a circle of radius L (a "baryon") immersed in the hot plasma of a gauge theory with Nc colors defines a screening length Ls. We use the AdS/CFT correspondence to compute this screening length for the case of heavy quarks in the plasma of strongly coupled N=4 super Yang-Mills theory moving with velocity v relative to the baryon. We find that in the v -> 1 limit, Ls \\propto (1-v^2)^{1/4}/T, and find that corrections to this velocity dependence are small at lower velocities. This result provides evidence for the robustness of the analogous behavior of the screening length defined by the static quark-antiquark pair, which has been computed previously and in QCD is relevant to quarkonium physics in heavy ion collisions. Our results also show that as long as the hot wind is not blowing precisely perpendicular to the plane of the baryon configuration that we analyze, the Nc different quarks are not all affected by the wind velocity to the same degree, with those quarks lying perpendicular to the wind direction screened most effectively.

Christiana Athanasiou; Hong Liu; Krishna Rajagopal

2008-01-07T23:59:59.000Z

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


361

Velocity Dependence of Baryon Screening in a Hot Strongly Coupled Plasma  

E-Print Network (OSTI)

The L-dependence of the static potential between Nc quarks arranged in a circle of radius L (a "baryon") immersed in the hot plasma of a gauge theory with Nc colors defines a screening length Ls. We use the AdS/CFT correspondence to compute this screening length for the case of heavy quarks in the plasma of strongly coupled N=4 super Yang-Mills theory moving with velocity v relative to the baryon. We find that in the v -> 1 limit, Ls \\propto (1-v^2)^{1/4}/T, and find that corrections to this velocity dependence are small at lower velocities. This result provides evidence for the robustness of the analogous behavior of the screening length defined by the static quark-antiquark pair, which has been computed previously and in QCD is relevant to quarkonium physics in heavy ion collisions. Our results also show that as long as the hot wind is not blowing precisely perpendicular to the plane of the baryon configuration that we analyze, the Nc different quarks are not all affected by the wind velocity to the same de...

Athanasiou, Christiana; Rajagopal, Krishna

2008-01-01T23:59:59.000Z

362

Carbon monoxide oxidation on Rh(111): Velocity and angular distributions of the CO2 product  

E-Print Network (OSTI)

Carbon monoxide oxidation on Rh(111): Velocity and angular distributions of the CO2 product J. I and angular distributions of CO2 produced by CO oxidation on Rh 111 have been measured as a function a fundamental and a practical point of view. CO2 formation serves as a model recombina- tion reaction

Sibener, Steven

363

THE VELOCITY CENTROID PERIODICITY OF L2 PUPPIS' SiO MASER EMISSION  

SciTech Connect

We report the first short term velocity centroid (VC) periodicity derived from SiO maser emission. L2 Puppis, a semi-regular AGB star, was observed using the Mopra radio telescope of the Australia Telescope National Facility in the SiO v = 1, J = 1-0 and v = 1, J = 2-1 transitions. It exhibits a 139 day period in its SiO maser VC based on a period folding analysis and a Lomb Scargle analysis. L2 Pup's SiO maser emission has an unusually large velocity range and an unusual three-peaked spectrum. To create the change in VC the entire spectrum does not shift in velocity, but changes in the relative emission of the peaks generate the variation. The changes in the VC may be due to differential illumination, an asymmetric circumstellar distribution of material, or a mixture of causes. The unusual velocity structure, similar to that observed in Orion source 1, may be due to revolution of the circumstellar material or asymmetries in the circumstellar environment.

McIntosh, Gordon C. [Division of Science and Mathematics, University of Minnesota, Morris, Morris, MN 56267 (United States); Indermuehle, Balthasar [Australia Telescope National Facility, Locked Bag 194, Narrabri, NSW 2390 (Australia)

2013-09-01T23:59:59.000Z

364

Evolution of seismic velocities in heavy oil sand reservoirs during thermal recovery process  

E-Print Network (OSTI)

1 Evolution of seismic velocities in heavy oil sand reservoirs during thermal recovery process localiser la chambre à vapeur. INTRODUCTION [1] Huge quantities of heavy oils (heavy oil, extra heavy oil. Larribau 64018 Pau Cedex, France Oil and Gas Science and Technology 2012, 67 (6), 1029-1039, doi:10

Paris-Sud XI, Université de

365

Time Series Measurements of Temperature, Current Velocity, and Sediment Resuspension in Saginaw Bay  

E-Print Network (OSTI)

Time Series Measurements of Temperature, Current Velocity, and Sediment Resuspension in Saginaw Bay and verification. These measurements will be made as part of this project. Measurements of sediment resuspension sediment resuspension in the bay during the spring. Measurements of sediment resuspension are important

366

Geophysical Prospecting, 2006, 54, 565573 Influence of pore pressure on velocity in low-porosity sandstone  

E-Print Network (OSTI)

than unity for low-porosity rocks and that it varies with porosity, rock texture and wave type. We Pressure strongly influences the mechanical and transport properties of rocks, such as porosity, velocity, permeability and resistivity. In a fluid-saturated rock, both pore pressure and confining pressure control

367

Standard practice for measuring the ultrasonic velocity in polyethylene tank walls using lateral longitudinal (LCR) waves  

E-Print Network (OSTI)

1.1 This practice covers a procedure for measuring the ultrasonic velocities in the outer wall of polyethylene storage tanks. An angle beam lateral longitudinal (LCR) wave is excited with wedges along a circumferential chord of the tank wall. A digital ultrasonic flaw detector is used with sending-receiving search units in through transmission mode. The observed velocity is temperature corrected and compared to the expected velocity for a new, unexposed sample of material which is the same as the material being evaluated. The difference between the observed and temperature corrected velocities determines the degree of UV exposure of the tank. 1.2 The practice is intended for application to the outer surfaces of the wall of polyethylene tanks. Degradation typically occurs in an outer layer approximately 3.2-mm (0.125-in.) thick. Since the technique does not interrogate the inside wall of the tank, wall thickness is not a consideration other than to be aware of possible guided (Lamb) wave effects or reflection...

American Society for Testing and Materials. Philadelphia

2011-01-01T23:59:59.000Z

368

Group-velocity tomography of South America and the surrounding oceans  

E-Print Network (OSTI)

Group-velocity tomography of South America and the surrounding oceans Oleg Vdovin,1 Jose¨ A. Rial,2 propagating across South America and the surrounding oceans. Broad-band waveform data from about 765 events and show that the average resolution across South America is about 60^80 for Rayleigh waves and 70

Ritzwolle, Mike

369

LONG INDUCED VOLTAGE ELECTROMAGNETIC FLOWMETERS AND THE EFFECT OF VELOCITY PROFILE  

Science Journals Connector (OSTI)

......infinitely long electrodes. The effect of non-uniform (plane) magnetic...ELECTROMAGNETIC FLOWMETERS AND THE EFFECT OF VELOCITY PROFILE ByM. K...infinitely long electrodes. The effect of non-uniform (plane) magnetic...which might be the hull of a ship, and as flowmeters for measuring......

M. K. BEVIR

1971-08-01T23:59:59.000Z

370

Temporally resolved ion velocity distribution measurements in a radio-frequency plasma sheath  

E-Print Network (OSTI)

and within a radio-frequency (RF) biased plasma sheath is studied experimentally with a pulsed laserTemporally resolved ion velocity distribution measurements in a radio-frequency plasma sheath B; therefore, radio-frequency (RF) biases which result in zero net electrical current to the substrate

California at Los Angles, University of

371

The Effects of Indoor Air Velocity on Occupant Thermal Comfort in Winter  

E-Print Network (OSTI)

In China the thermal comfort standard that regulates the indoor air velocity cannot exceed 0.15m/s in winter. But many scholars doubt this regulation. This paper presents the results of an experimental research project on thermal comfort...

Wang, J.; Chen, L.

2006-01-01T23:59:59.000Z

372

Application of the velocity-dissipation probability density function model to inhomogeneous turbulent flows  

E-Print Network (OSTI)

Application of the velocity-dissipation probability density function model to inhomogeneous. Fluids A 2, 1437 ( 1990) ] developed a turbulence model based on the one-point Eulerian joint probability were constructed by reference to the known statistics of homogenous turbulence, and the applicability

373

Compressional and shear velocities of dry and saturated jointed rock: a laboratory study  

Science Journals Connector (OSTI)

......classification of rock mass qualities, Geophys...shallow jointed rock, Int. J...a jointed sandstone, in Mechanical...fracture permeability, Int. J...microcrack porosity. By modelling...and steam reservoirs require...hot-dry-rock method are...evaluating the quality of large...and fluid permeability. Seismic...aperture or porosity. Moos...velocity in a sandstone is independent......

R. M. Stesky

1985-10-01T23:59:59.000Z

374

A comparison of velocity measurements from the CUTLASS Finland radar and the EISCAT UHF system  

E-Print Network (OSTI)

A comparison of velocity measurements from the CUTLASS Finland radar and the EISCAT UHF system J. A January 1999 Abstract. The CUTLASS Finland radar, which com- prises an integral part of the Super irregularities within a ®eld-of- view which extends over some four million square kilometres. Within the Finland

Paris-Sud XI, Université de

375

A New Global Rayleigh and Love Wave Group Velocity Dataset For Constraining Lithosphere Properties  

E-Print Network (OSTI)

A New Global Rayleigh and Love Wave Group Velocity Dataset For Constraining Lithosphere Properties features and fit our data very well. This dataset will be used to constrain lithospheric structure globally the global datasets used in Ritzwoller et al. (2002) already consist of more than 100,000 paths, the nature

Laske, Gabi

376

Velocity map imaging studies of the Lyman ? photodissociation mechanism for H atom production from hydrocarbons  

Science Journals Connector (OSTI)

H atoms produced in Lyman ? photolysis of ethane propane and ethylene have been studied using velocity map imaging techniques. Two types of H atoms are identified one formed along with an alkyl radical in the Rydberg state and the other by the subsequent decomposition of this Rydberg radical.

William M. Jackson; Roosevelt J. Price II; D. D. Xu; Jacek D. Wrobel; Musahid Ahmed; Darcy S. Peterka; Arthur G. Suits

1998-01-01T23:59:59.000Z

377

Velocity map imaging studies of the Lyman alpha photodissociationmechanism for H atom production from hydrocarbons  

SciTech Connect

H atoms produced in Lyman ct photolysis of ethane, propane,and ethylene have been studied using velocity map imaging techniques. Twotypes of H atoms are identified, one formed along with an alkyl radicalin the Rydberg state and the other by the subsequent decomposition ofthis Rydberg radical. (C) 1998 American Institute of Physics.

Jackson, William M.; Price, Roosevelt; Wrobel, Jacek; Xu, Dadong; Ahmed, Musahid; Peterka, Darcy S.; Suits, Arthur G.

1998-06-01T23:59:59.000Z

378

Velocity map imaging studies of the Lyman {alpha} photodissociation mechanism for H atom production from hydrocarbons  

SciTech Connect

H atoms produced in Lyman {alpha} photolysis of ethane, propane, and ethylene have been studied using velocity map imaging techniques. Two types of H atoms are identified, one formed along with an alkyl radical in the Rydberg state and the other by the subsequent decomposition of this Rydberg radical. {copyright} {ital 1998 American Institute of Physics.}

Jackson, W.M.; Price, R.J. II; Xu, D.D.; Wrobel, J.D. [Department of Chemistry, University of California, Davis, California 95616 (United States)] [Department of Chemistry, University of California, Davis, California 95616 (United States); Ahmed, M.; Peterka, D.S.; Suits, A.G. [Chemical Dynamics Group, Chemical Sciences Division, Ernest Orlando Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States)] [Chemical Dynamics Group, Chemical Sciences Division, Ernest Orlando Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States)

1998-09-01T23:59:59.000Z

379

Methods for determining infrasound phase velocity direction with an array of line sensors  

E-Print Network (OSTI)

Methods for determining infrasound phase velocity direction with an array of line sensors to the number of these point sensors; additional sensors help attenuate noise and improve direction resolution. An alternative approach is to form an array of directional line sensors, each of which emulates a line of many

Vernon, Frank

380

ATLAS MOTION PLATFORM MECANUM WHEEL JACOBIAN IN THE VELOCITY AND STATIC FORCE DOMAINS  

E-Print Network (OSTI)

ATLAS MOTION PLATFORM MECANUM WHEEL JACOBIAN IN THE VELOCITY AND STATIC FORCE DOMAINS Jonathan J applications. Atlas is a six degree of freedom vehicle op- erating training simulator motion platform where and static force Jacobians; normal forces. JACOBIAN DES ROUES MECANUM DU PLATFORME DE MOTION ATLAS DANS LES

Hayes, John

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


381

ATLAS MOTION PLATFORM MECANUM WHEEL JACOBIAN IN THE VELOCITY AND STATIC FORCE DOMAINS  

E-Print Network (OSTI)

ATLAS MOTION PLATFORM MECANUM WHEEL JACOBIAN IN THE VELOCITY AND STATIC FORCE DOMAINS Jonathan J. Atlas is a six degree of freedom vehicle op- erating training simulator motion platform where orienting force Jacobians; normal forces. MATRICE JACOBIENNE DES ROUES MECANUM SIMULATOUR DE MOUVEMENT ATLAS DANS

Hayes, John

382

Velocity bias from the small-scale clustering of SDSS-III BOSS galaxies  

Science Journals Connector (OSTI)

......results is demonstrated by a variety of tests. We discuss the implications of the existence...velocity bias. We perform a variety of tests to establish the robustness of the results...Section-5. In the appendices, we provide a test of fibre-collision correction with a......

Hong Guo; Zheng Zheng; Idit Zehavi; Kyle Dawson; Ramin A. Skibba; Jeremy L. Tinker; David H. Weinberg; Martin White; Donald P. Schneider

2015-01-01T23:59:59.000Z

383

Optimization of the structural Gabor functions in a homogeneous velocity model  

E-Print Network (OSTI)

Optimization of the structural Gabor functions in a homogeneous velocity model for a zero-o#11;set functions should be optimized, and the Gabor functions should form a frame. We present a simple attempt functions and the space{wavenumber lattice of their central points are optimized analytically

Cerveny, Vlastislav

384

Ris-M-2208 MECHANICAL VELOCITY SELECTOR, NEUTRON FLUX AND Q-RANGE  

E-Print Network (OSTI)

the geometry of the proposed small angle neutron scattering (SANS) instrument. At the end of the tube, corre APPENDIX B 23 APPENDIX C 26 #12;- 5 - I. INTRODUCTION The proposed Small Angle Neutron Scattering (SANSRisø-M-2208 MECHANICAL VELOCITY SELECTOR, NEUTRON FLUX AND Q-RANGE FOR THE SMALL ANGLE NEUTRON

385

A direct method for the Boltzmann equation based on a pseudo-spectral velocity space discretization  

Science Journals Connector (OSTI)

A deterministic method is proposed for solving the Boltzmann equation. The method employs a Galerkin discretization of the velocity space and adopts, as trial and test functions, the collocation basis functions based on weights and roots of a Gauss-Hermite ... Keywords: Boltzmann equation, Deterministic solution, Galerkin method, Gaussian quadrature, Half- and full-range Hermite polynomials

G. P. Ghiroldi; L. Gibelli

2014-02-01T23:59:59.000Z

386

Miocene faulting at plate tectonic velocity in the Himalaya of central Nepal  

E-Print Network (OSTI)

Miocene faulting at plate tectonic velocity in the Himalaya of central Nepal Matthew J. Kohna, Tri-Chandra Campus, Ghantaghar, Kathmandu, Nepal, United States Received 7 April 2004; received (MCT) and affiliated faults in central Nepal. Inferred rates were 1.5F0.9 cm/yr (Langtang Thrust, ~19

387

Velocity Distribution of the Ions Producing Neutrons in a Plasma Focus  

Science Journals Connector (OSTI)

There is evidence for a noncollision dominated velocity distribution (average energy of at least 20 keV) of the ions producing the neutrons in a dense plasma focus. For a group of ions moving in the axial direction the average energy is at least 0.3 MeV.

H. Conrads; P. Cloth; M. Demmeler; R. Hecker

1972-01-01T23:59:59.000Z

388

X-ray driven implosions at ignition relevant velocities on the National Ignition Facility  

SciTech Connect

Backlit convergent ablator experiments on the National Ignition Facility [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)] are indirect drive implosions that study the inflight dynamics of an imploding capsule. Side-on, backlit radiography provides data used by the National Ignition Campaign to measure time-dependent properties of the capsule ablator including its center of mass radius, velocity, and unablated mass. Previously, Callahan [D. A. Callahan et al., Phys. Plasmas 19, 056305 (2012)] and Hicks [D. H. Hicks et al., Phys. Plasmas 19, 122702 (2012)] reported backlit convergent ablator experiments demonstrating velocities approaching those required for ignition. This paper focuses on implosion performance data in the “rocket curve” plane, velocity vs. ablator mass. These rocket curve data, along with supporting numerical simulations, show that the nominal 195 ?m-thick ignition capsule would reach the ignition velocity goal V = 370 km/s with low ablator mass remaining–below the goal of M = 0.25 mg. This finding led to experiments with thicker capsule ablators. A recent symmetry capsule experiment with a 20 ?m thicker capsule driven by 520 TW, 1.86 MJ laser pulse (along with a companion backlit convergent ablator experiment) appears to have demonstrated V?350 km/s with ablator mass remaining above the ignition goal.

Meezan, N. B.; MacKinnon, A. J.; Hicks, D. G.; Dewald, E. L.; Tommasini, R.; Le Pape, S.; Döppner, T.; Ma, T.; Farley, D. R.; Kalantar, D. H.; Di Nicola, P.; Callahan, D. A.; Robey, H. F.; Thomas, C. A.; Prisbrey, S. T.; Jones, O. S.; Milovich, J. L.; Clark, D. S.; Eder, D. C.; Schneider, M. B. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States)] [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States); and others

2013-05-15T23:59:59.000Z

389

The power spectrum of the Milky Way: Velocity fluctuations in the Galactic disk  

E-Print Network (OSTI)

We investigate the kinematics of stars in the mid-plane of the Milky Way on scales between 25 pc and 10 kpc with data from the Apache Point Observatory Galactic Evolution Experiment (APOGEE), the Radial Velocity Experiment (RAVE), and the Geneva-Copenhagen Survey (GCS). Using red-clump stars in APOGEE, we determine the large-scale line-of-sight velocity field out to 5 kpc from the Sun in (0.75 kpc)^2 bins. The solar motion is the largest contribution to the power on large scales after subtracting an axisymmetric rotation field; we determine the solar motion by minimizing the large-scale power to be V_sun = 24+/-1 (ran.)+/-2 (syst [V_c])+/-5 (syst. [large-scale]) km/s, where the systematic uncertainty is due to (a) a conservative 20 km/s uncertainty in V_c and (b) the estimated power on unobserved larger scales. Combining the APOGEE peculiar-velocity field with red-clump stars in RAVE out to 2 kpc from the Sun and with local GCS stars, we determine the power spectrum of residual velocity fluctuations in the Mi...

Bovy, Jo; Pérez, Ana E García; Zasowski, Gail

2014-01-01T23:59:59.000Z

390

Gas Density Fluctuations in the Perseus Cluster: Clumping Factor and Velocity Power Spectrum  

E-Print Network (OSTI)

X-ray surface brightness fluctuations in the core of the Perseus Cluster are analyzed, using deep observations with the Chandra observatory. The amplitude of gas density fluctuations on different scales is measured in a set of radial annuli. It varies from 8 to 12 per cent on scales of ~10-30 kpc within radii of 30-160 kpc from the cluster center and from 9 to 7 per cent on scales of ~20-30 kpc in an outer, 60-220 kpc annulus. Using a statistical linear relation between the observed amplitude of density fluctuations and predicted velocity, the characteristic velocity of gas motions on each scale is calculated. The typical amplitudes of the velocity outside the central 30 kpc region are 90-140 km/s on ~20-30 kpc scales and 70-100 km/s on smaller scales ~7-10 kpc. The velocity power spectrum is consistent with cascade of turbulence and its slope is in a broad agreement with the slope for canonical Kolmogorov turbulence. The gas clumping factor estimated from the power spectrum of the density fluctuations is low...

Zhuravleva, I; Arevalo, P; Schekochihin, A A; Allen, S W; Fabian, A C; Forman, W R; Sanders, J S; Simionescu, A; Sunyaev, R; Vikhlinin, A; Werner, N

2015-01-01T23:59:59.000Z

391

Magnetic Reconnection Flux and Coronal Mass Ejection Velocity Jiong Qiu1,2,3  

E-Print Network (OSTI)

, the CME velocity and kinematic energy are probably independent of magnetic configurations of source 1. Big Bear Solar Observatory, New Jersey Institute of Technology 40386 N. Shore Ln., Big Bear City reconnection flux is an important physi- cal parameter interacting with the flux rope evolution. Independent

Yurchyshyn, Vasyl

392

Vorticity and Divergence of Surface Velocities Near Shore JEROME A. SMITH  

E-Print Network (OSTI)

Vorticity and Divergence of Surface Velocities Near Shore JEROME A. SMITH Scripps Institution, and nearshore mixing-scale motions are generally undersampled (but see, e.g., Smith and Largier 1995; Johnson m 300 m on a side (Smith 2002a,b). Thus, these data focus more toward the small end of the range

Smith, Jerome A.

393

Numerical investigation of low-velocity impacts on monolithic and laminated safety glass  

E-Print Network (OSTI)

Numerical investigation of low-velocity impacts on monolithic and laminated safety glass Researcher objects are one of the most common incidents to impact on glass floors or stairs during day to day experienced during hard body impacts on monolithic and laminated safety glass, mainly of structural use

Birmingham, University of

394

Joint inversion for three dimensional S velocity mantle structure along the Tethyan margin  

E-Print Network (OSTI)

construct a new three dimensional S velocity model and Moho map by jointly inverting regional S and Rayleigh and overlapping nature of the different data sets' resolving power has reduced disparities in resolving power that exist for individual data sets, for example between resolving power for crustal and lower mantle

van der Lee, Suzan

395

CALTECH ASCI TECHNICAL REPORT 129 On Velocity Structure Functions and the Spherical Vortex Model for  

E-Print Network (OSTI)

the stretched-spiral vortex has been suc- cessfully applied to the calculation of the energy spectrum,6 and some for larger scales is perhaps questionable. Most quantitative vortex-based models have utilized tube and sheetCALTECH ASCI TECHNICAL REPORT 129 On Velocity Structure Functions and the Spherical Vortex Model

Barr, Al

396

Summary of groundwater flow direction and velocity in the general separations area  

SciTech Connect

GeoTrans data from the model of groundwater flow and contaminant transport in the central portion of the Savannah River Plant (General Separations Area) was used to compute groundwater flow direction and velocities. This report describes the modeling area, shows method of computations, and illustrates the results in figure form. 1 ref., 12 figs., 2 tabs.

Scott, M.T.

1986-06-18T23:59:59.000Z

397

Bifractality of the Devil's staircase appearing in the Burgers equation with Brownian initial velocity  

E-Print Network (OSTI)

It is shown that the inverse Lagrangian map for the solution of the Burgers equation (in the inviscid limit) with Brownian initial velocity presents a bifractality (phase transition) similar to that of the Devil's staircase for the standard triadic Cantor set. Both heuristic and rigorous derivations are given. It is explained why artifacts can easily mask this phenomenon in numerical simulations.

E. Aurell; U. Frisch; A. Noullez; M. Blank

1996-11-20T23:59:59.000Z

398

Ultra-high-speed optical and electronic distributed devices  

SciTech Connect

This report summarizes work on the development of ultra-high-speed semiconductor optical and electronic devices. High-speed operation is achieved by velocity matching the input stimulus to the output signal along the device`s length. Electronic devices such as field-effect transistors (FET`s), should experience significant speed increases by velocity matching the electrical input and output signals along the device. Likewise, optical devices, which are typically large, can obtain significant bandwidths by velocity matching the light being generated, detected or modulated with the electrical signal on the device`s electrodes. The devices discussed in this report utilize truly distributed electrical design based on slow-wave propagation to achieve velocity matching.

Hietala, V.M.; Plut, T.A.; Kravitz, S.H.; Vawter, G.A.; Wendt, J.R.; Armendariz, M.G.

1995-08-01T23:59:59.000Z

399

Interpreting Velocities from Heat-Based Flow Sensors by NumericalSimulation  

SciTech Connect

We have carried out numerical simulations of three-dimensional non-isothermal flow around an in situ heat-based flow sensor to investigate how formation heterogeneities can affect the interpretation of ground water flow velocities from this instrument. The flow sensor operates by constant heating of a 0.75 m long, 5 cm diameter cylindrical probe, which contains 30 thermistors in contact with the formation. The temperature evolution at each thermistor can be inverted to obtain an estimate of the ground water flow velocity vector using the standard interpretive method, which assumes that the formation is homogeneous. Analysis of data from heat-based flow sensors installed in a sand aquifer at the Former Fort Ord Army Base near Monterey, California suggested an unexpected component of downward flow. The magnitudes of the vertical velocities were expected to be much less than the horizontal velocities at this site because the sensors were installed just above a clay aquitard. Numerical simulations were conducted to examine how differences in thermal conductivities may lead to spurious indications of vertical flow velocities. We found that a decrease in the thermal conductivity near the bottom of the sensor can perturb the temperature profiles along the instrument in such a manner that analyses assuming homogeneous thermal conductivity could indicate a vertical flow component even though flow is actually horizontal. This work demonstrates how modeling can be used to simulate instrument response to formation heterogeneity, and shows that caution must be used in interpreting data from such devices using overly simplistic assumptions.

Su, Grace W.; Freifeld, Barry M.; Oldenburg, Curtis M.; Jordan,Preston D.; Daley, Paul F.

2005-06-13T23:59:59.000Z

400

Migration error in transversely isotropic media with linear velocity variation in depth  

SciTech Connect

Given the sensitivity of imaging accuracy to the velocity used in migration, migration founded (as in practice) on the erroneous assumption that a medium is isotropic can be expected to be inaccurate for steep reflectors. Here, we estimate errors in interpreted reflection time and lateral position as a function of reflector dip for transversely isotropic models in which the axis of symmetry is vertical and the medium velocity varies linearly with depth. We limit consideration to media in which ratios of the various elastic moduli are independent of depth. Tests with reflector dips up to 120 degrees on a variety of anisotropic media show errors that axe tens of wavelengths for dips beyond 90 degrees when the medium (unrealistically) is homogeneous. For a given anisotropy, the errors are smaller for inhomogeneous media; the larger the velocity gradient, the smaller the errors. For gradients that are representative of the subsurface, lateral-position errors tend to be minor for dips less than about 60 degrees, growing to two to five wavelengths as dip passes beyond 90 degrees. These errors depend on reflector depth and average velocity to the reflector only through their ratio, i.e., migrated reflection time. Migration error, which is found to be unrelated to the ratio of horizontal to vertical velocity, is such that reflections with later migrated reflection times tend to be more severely over-migrated than are those with earlier ones. Over a large range of dips, migration errors that arise when anisotropy is ignored but inhomogeneity is honored tend to be considerably smaller than those encountered when inhomogeneity is ignored in migrating data from isotropic, inhomogeneous media.

Larner, K.; Cohen, J.K.

1992-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high velocity sdhv" 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

Migration error in transversely isotropic media with linear velocity variation in depth  

SciTech Connect

Given the sensitivity of imaging accuracy to the velocity used in migration, migration founded (as in practice) on the erroneous assumption that a medium is isotropic can be expected to be inaccurate for steep reflectors. Here, we estimate errors in interpreted reflection time and lateral position as a function of reflector dip for transversely isotropic models in which the axis of symmetry is vertical and the medium velocity varies linearly with depth. We limit consideration to media in which ratios of the various elastic moduli are independent of depth. Tests with reflector dips up to 120 degrees on a variety of anisotropic media show errors that axe tens of wavelengths for dips beyond 90 degrees when the medium (unrealistically) is homogeneous. For a given anisotropy, the errors are smaller for inhomogeneous media; the larger the velocity gradient, the smaller the errors. For gradients that are representative of the subsurface, lateral-position errors tend to be minor for dips less than about 60 degrees, growing to two to five wavelengths as dip passes beyond 90 degrees. These errors depend on reflector depth and average velocity to the reflector only through their ratio, i.e., migrated reflection time. Migration error, which is found to be unrelated to the ratio of horizontal to vertical velocity, is such that reflections with later migrated reflection times tend to be more severely over-migrated than are those with earlier ones. Over a large range of dips, migration errors that arise when anisotropy is ignored but inhomogeneity is honored tend to be considerably smaller than those encountered when inhomogeneity is ignored in migrating data from isotropic, inhomogeneous media.

Larner, K.; Cohen, J.K.

1992-10-01T23:59:59.000Z

402

The Velocity of Propagation of Longitudinal Waves in Liquids at Audio-Frequencies  

Science Journals Connector (OSTI)

A method for measuring the velocity of propagation of longitudinal waves in liquids is described which is at the same time precise and convenient of application. A column of liquid contained in a cylindrical vertical steel tube was brought into resonance vibration at audio frequency by an electromagnetically excited diaphragm at the bottom. From the solution of the equation of propagation it is shown that when the resonance frequency of the system is the same as that of the diaphragm the reaction of the latter on the system is very small. The height of the column of liquid in the tube was adjusted until its natural frequency nearly corresponded with the predetermined resonance frequency of the diaphragm. The height was then varied slightly and the frequency adjusted until resonance occurred. From several observations of this type the appropriate height corresponding to the resonance frequency of the diaphragm was obtained by interpolation. The velocity of propagation of the longitudinal waves was then calculated from the relation V=f0, where f0 is the natural frequency of the diaphragm when clamped in the holder and ? is the wavelength.Correction for the elasticity of the walls of the tube.—The correction formulas of Korteweg, Lamb and Gronwall were tested experimentally on tubes of different dimensions. The latter was found to give the most satisfactory agreement, the two former being unsuitable for precision measurements.Measurements.—The velocity of sound was measured in air-free distilled water at 25°C. The average of 52 observations gave for this velocity 1485.4±2.3 m/sec. From this value the bulk modulus, G, and the adiabatic compressibility, ?, were calculated. Curves were plotted illustrating the variation of the velocity of sound with temperature for the range 25°-70°C and with concentration for solutions of NaCl and KCl of different normalities. Curves for the corresponding variations of G and ? are also given.

Louis Gordon Pooler

1930-04-01T23:59:59.000Z

403

Isokinetic vs still air sampling of asbestos fiber emission from high-velocity, low-volume vacuum systems  

E-Print Network (OSTI)

these types of asbestos is found in Table I. Archeological findings in Finland have shown that man used asbestos as early as 2500 B. C. It was used as a filler to hold pottery together before baking. Although the modern knowledge of 11 asbestos dates back...

Grabowski, John S

1979-01-01T23:59:59.000Z

404

Double seismic zone of the Nazca plate in northern Chile: High-resolution velocity structure, petrological implications,  

E-Print Network (OSTI)

with a partially ($25­30 vol % antigorite, $0­10% vol % brucite, and $4­10 vol % chlorite) hydrated harzburgitic

Vallée, Martin

405

A high-velocity narrow absorption line outflow in the quasar J212329.46 – 005052.9  

Science Journals Connector (OSTI)

......13694 13179 0.075 111 E 1551 4850.6 2.12788 14045 0.180 147 4850.4 2.12775 14056 0.114 142 E 1548 4842.4 2.12776 14056 0.245 154 4842.8 2.12799 14034 0.133 121 1551 4966.3 2.20246 6987 0.024 27.1 - - - - - 1548 4958.1 2......

F. Hamann; N. Kanekar; J. X. Prochaska; M. T. Murphy; S. Ellison; A. L. Malec; N. Milutinovic; W. Ubachs

2011-01-21T23:59:59.000Z

406

Lateral diffusive migration of massive particles in high-velocity vertical pipe flow of moderately dense gas-solid suspensions  

E-Print Network (OSTI)

, Lappeenranta University of Technology, Lappeenranta, Finland John C. Chen Department of Chemical Engineering

Tafreshi, Hooman Vahedi

407

Seismic surface waves and associated phenomena in a system involving a shallow, thin, high-velocity layer  

E-Print Network (OSTI)

Dissertation by JOSEPH MICHAEL EGAR Approved as to style and content by: A ' 1 \\ Co-Chairmen of Committee __ ____________ C 'l .____________________ H??ad of Department of Geology and Geophysics May, 1959 i ii 1 2 3 4 5 7 8 11 13 15 25 25..., p. 193): \\ c o s rH + r H ) + 2 ^ n # V s i o s H - ^ ^ 5s/4 ) f2.-c^ *)(^v/oesi*H + kjf-2sm vH)+ %(Xsin sB -s/&ycossff) \\ = (Z-tffpycfcwcos sH+ % ? s i * s H ) - l - 2 l&(Xsir'ir' H - |r?A-/o?rH) ^ X co s s H + S'A Vsm s h ) 1 2 vkfflk...

Egar, Joseph Michael

1959-01-01T23:59:59.000Z

408

Evaluation of asbestos dust concentration in discharge air from a high-velocity low-volume vacuum system  

E-Print Network (OSTI)

) Increased depth of focus, 2) Higher resolution, 3) greater contrast between fiber and background. The first advantage enables a11 fibers to be focused at one microscope position, Detection of the finer fibers and an increase in the precision of the size...

Daniel, Steven Hall

1977-01-01T23:59:59.000Z

409

Size-velocity correlations in high order moment methods for polydisperse evaporating sprays: modelling and numerical issues  

E-Print Network (OSTI)

, such as internal combustion engine ([1, 2] and references therein), gas turbine [3] or rocket booster [4]. Those developed the Eulerian Multi-Size Moment model (EMSM) which tackles the modelling and the numerical aspects of the disperse phase. The full strategy is evaluated in 1D and 2D cases and shows the ability of the CSVM and its

Paris-Sud XI, Université de

410

The structural and mechanical properties of a Cu??Zr??(at. %) alloy processed by High-Velocity-Injection (HVI)  

E-Print Network (OSTI)

) cooling rate, (3) defects and/or defect structure, (4) density and, (5) purity. The samples investigated in this research will be a copper- zirconium alloy of composition Cu Zr (at. ?) . This alloy was chosen because it is a member of a group...+Zr, C E6 8220C 4~0. 2 a~Zr, Cu 3200 2800 u 2600 ur 2400 g O 2200 ~ 2000 ~ i800 ~ l 600 i 100'C piZrCu3 965'C 935'C 895 C )I Sar I I g 47 92PC ~ 'C 1 400 Zr, cu $ ZrCu R O ZrCu~+Cu l200 lO 20 30 40 50 60 70 80 90 l00 WEIGHT...

Hays, Charles C.

2012-06-07T23:59:59.000Z

411

Nanofriction Mechanisms Derived from the Dependence of Friction on Load and Sliding Velocity from Air to UHV on Hydrophilic Silicon  

Science Journals Connector (OSTI)

This paper examines friction as a function of the sliding velocity and applied normal load from air to UHV in a scanning force microscope (SFM)...

A. Opitz; S. I.-U. Ahmed; M. Scherge; J.A. Schaefer

2005-12-01T23:59:59.000Z

412

Is it Possible to Transfer an Information with the Velocities Exceeding Speed of Light in Empty Space?  

E-Print Network (OSTI)

On the base of the theory of time and space with the fractional dimensions a possibility for information transferring with arbitrary velocities is demonstrated

L. Ya. Kobelev

2000-02-01T23:59:59.000Z

413

Laminar burning velocities of lean hydrogen-air mixtures at pressures up to 1.0 MPa  

SciTech Connect

Values of laminar burning velocity, u{sub l}, and the associated strain rate Markstein number, Ma{sub sr}, of H{sub 2}-air mixtures have been obtained from measurements of flame speeds in a spherical explosion bomb with central ignition. Pressures ranged from 0.1 to 1.0 MPa, with values of equivalence ratio between 0.3 and 1.0. Many of the flames soon became unstable, with an accelerating flame speed, due to Darrieus-Landau and thermodiffusive instabilities. This effect increased with pressure. The flame wrinkling arising from the instabilities enhanced the flame speed. A method is described for allowing for this effect, based on measurements of the flame radii at which the instabilities increased the flame speed. This enabled u{sub l} and Ma{sub sr} to be obtained, devoid of the effects of instabilities. With increasing pressure, the time interval between the end of the ignition spark and the onset of flame instability, during which stable stretched flame propagation occurred, became increasingly small and very high camera speeds were necessary for accurate measurement. Eventually this time interval became so short that first Ma{sub sr} and then u{sub l} could not be measured. Such flame instabilities throw into question the utility of u{sub l} for high pressure, very unstable, flames. The measured values of u{sub l} are compared with those predicted by detailed chemical kinetic models of one-dimensional flames. (author)

Bradley, D.; Lawes, M.; Liu, Kexin; Woolley, R. [School of Mechanical Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom); Verhelst, S. [Department of Flow, Heat and Combustion Mechanics, Ghent University, Sint-Pietersnieuwstraat 41, B-9000 Ghent (Belgium)

2007-04-15T23:59:59.000Z

414

Analysis of the influence of the normal zone propagation velocity on the design of resistive fault current limiters  

Science Journals Connector (OSTI)

Commercial high-temperature superconducting coated conductors (HTS-CCs) have low thermal diffusivity and nonuniform critical current density. These two factors lead commercial HTS-CCs to a partial quench when they are subjected to a transport current around their average critical current (). The consequence is the appearance of localized resistive zones, and a high risk of thermal runaway can arise when HTS-CCs are used for resistive fault current limiter (RFCL) purposes. The enhancement of the normal zone propagation velocity (NZPV) of HTS-CCs is a desirable solution for achieving sufficient thermal stability while keeping the cost of RFCLs under an acceptable threshold. Even though in recent years, several valid methods to increase the NZPV have been proposed, their impact on the design of RFCLs is not clear. For this reason, we developed a one-dimensional numerical model that enables us to simulate HTS-CCs with enhanced NZPV and to study the limitation performance of a HTS-CC-based RFCL in real operating conditions. Our preliminary re sults demonstrate that the NZPV enhancement can effectively limit the needed amount of HTS-CCs with important economic benefits for the design of RFCLs.

Daniele Colangelo; Bertrand Dutoit

2014-01-01T23:59:59.000Z

415

A global 3D P-velocity model of the Earth's crust and mantle for improved event location.  

SciTech Connect

To test the hypothesis that high quality 3D Earth models will produce seismic event locations which are more accurate and more precise, we are developing a global 3D P wave velocity model of the Earth's crust and mantle using seismic tomography. In this paper, we present the most recent version of our model, SALSA3D (SAndia LoS Alamos) version 1.4, and demonstrate its ability to reduce mislocations for a large set of realizations derived from a carefully chosen set of globally-distributed ground truth events. Our model is derived from the latest version of the Ground Truth (GT) catalog of P and Pn travel time picks assembled by Los Alamos National Laboratory. To prevent over-weighting due to ray path redundancy and to reduce the computational burden, we cluster rays to produce representative rays. Reduction in the total number of ray paths is > 55%. The model is represented using the triangular tessellation system described by Ballard et al. (2009), which incorporates variable resolution in both the geographic and radial dimensions. For our starting model, we use a simplified two layer crustal model derived from the Crust 2.0 model over a uniform AK135 mantle. Sufficient damping is used to reduce velocity adjustments so that ray path changes between iterations are small. We obtain proper model smoothness by using progressive grid refinement, refining the grid only around areas with significant velocity changes from the starting model. At each grid refinement level except the last one we limit the number of iterations to prevent convergence thereby preserving aspects of broad features resolved at coarser resolutions. Our approach produces a smooth, multi-resolution model with node density appropriate to both ray coverage and the velocity gradients required by the data. This scheme is computationally expensive, so we use a distributed computing framework based on the Java Parallel Processing Framework, providing us with {approx}400 processors. Resolution of our model is assessed using a variation of the standard checkerboard method, as well as by directly estimating the diagonal of the model resolution matrix based on the technique developed by Bekas, et al. We compare the travel-time prediction and location capabilities of this model over standard 1D models. We perform location tests on a global, geographically-distributed event set with ground truth levels of 5 km or better. These events generally possess hundreds of Pn and P phases from which we can generate different realizations of station distributions, yielding a range of azimuthal coverage and proportions of teleseismic to regional arrivals, with which we test the robustness and quality of relocation. The SALSA3D model reduces mislocation over standard 1D ak135, especially with increasing azimuthal gap. The 3D model appears to perform better for locations based solely or dominantly on regional arrivals, which is not unexpected given that ak135 represents a global average and cannot therefore capture local and regional variations.

Ballard, Sanford; Encarnacao, Andre Villanova; Begnaud, Michael A. (Los Alamos National Laboratories); Rowe, Charlotte A. (Los Alamos National Laboratories); Lewis, Jennifer E.; Young, Christopher John; Chang, Marcus C.; Hipp, James Richard

2010-04-01T23:59:59.000Z

416

Upper mantle structure of South America from joint inversion of waveforms and fundamental mode group velocities of Rayleigh waves  

E-Print Network (OSTI)

Upper mantle structure of South America from joint inversion of waveforms and fundamental mode tomographic S wave velocity model for the upper mantle beneath South America is presented. We developed three-dimensional (3-D) upper mantle S velocity model and a Moho depth model for South America, which

van der Lee, Suzan

417

Boundary problems for the one-dimensional kinetic equation with the collisional frequence proportional to the module velocity of molecules  

E-Print Network (OSTI)

For the one-dimensional linear kinetic equations with collisional frequency of the molecules, proportional to the module velocity of molecules, analytical solutions of problems about temperature jump and weak evaporation (condensation) in rarefied gas are received. Quantities of temperature and concentration jumps are found. Distributions of concentration, mass velocity and temperature are constructed. Necessary numerical calculations and graphic researches are done.

A. V. Latyshev; A. A. Yushkanov

2014-06-08T23:59:59.000Z

418

Minimum-Energy Filtering on the Unit Circle Using Velocity Measurements with Bias and Vectorial state Measurements  

E-Print Network (OSTI)

Minimum-Energy Filtering on the Unit Circle Using Velocity Measurements with Bias and Vectorial consider minimum-energy filtering of a system defined on the unit circle when the angular velocity measure approximate minimum- energy filter for this system using vectorial measurements. This work extends prior work

Trumpf, Jochen

419

Influence of orographic and canopy conditions on friction velocities observed during frontal events using Doppler sodar observations  

SciTech Connect

Sodar friction velocities, obtained during frontal events traversing areas characterized by different orographic and canopy conditions (flat, bare ground, small hills and valleys with agricultural crops and trees, agricultural crops and forest on a flat ground, bare ground on the side of a mountain), are compared in order to identify the influence of topography on this parameter. For some case studies, sounding and sodar data are combined in order to provide a relation between the friction velocity and the low-level jet presence. For the cases analyzed in this paper, the following results are obtained: the frontal passage is associated with a decrease of the horizontal wind speed (about 50% in magnitude) in the surface layer, and an increase of the friction velocity before the frontal passage followed by a decrease just at the time of the frontal passage or with a little delay. Friction velocity is more intense in the cold side of the low-level jet and its maximum represents 2% of the low-level jet maximum magnitude. As it concerns the influence of the terrain conditions on friction velocity, mountain effects yield to more intense friction-velocity values and to a superposition of an oscillating behavior on the time variation of friction velocity, while forest effects induce a shift of the frontal signature on the time variation of friction velocity at higher height levels. 25 refs., 18 figs., 3 tabs.

Kotroni, V.; Amory-Mazaudier, C. (CRPE, Saint-Maur des Fosses (France))

1993-03-01T23:59:59.000Z

420

Measurement of shear wave velocity of heavy oil De-hua Han, Jiajin Liu, University of Houston  

E-Print Network (OSTI)

for measurement of fluid velocity is to measure the travel time of the transmission wave and then the velocity can water, has been used and is good for P-wave measurement for a lot of fluid samples. But the transmission the principle of this method. The shear wave transducer is coupled with a buffer made of some kind of plastic

Note: This page contains sample records for the topic "high velocity sdhv" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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421

Generalized 2D Euler–Boussinesq equations with a singular velocity  

Science Journals Connector (OSTI)

Abstract This paper studies the global (in time) regularity problem concerning a system of equations generalizing the two-dimensional incompressible Boussinesq equations. The velocity here is determined by the vorticity through a more singular relation than the standard Biot–Savart law and involves a Fourier multiplier operator. The temperature equation has a dissipative term given by the fractional Laplacian operator ? ? . We establish the global existence and uniqueness of solutions to the initial-value problem of this generalized Boussinesq equations when the velocity is “double logarithmically” more singular than the one given by the Biot–Savart law. This global regularity result goes beyond the critical case. In addition, we recover a result of Chae, Constantin and Wu [8] when the initial temperature is set to zero.

Durga KC; Dipendra Regmi; Lizheng Tao; Jiahong Wu

2014-01-01T23:59:59.000Z

422

Velocity-dependent total scattering cross sections for metastable helium on Kr and Xe  

Science Journals Connector (OSTI)

Single-beam attenuation measurements of velocity-dependent total scattering cross sections for the interactions of metastable helium (He*) on Kr and Xe targets have been measured in the 1-5-km/s relative-velocity range. The results are compared with cross sections obtained by full quantum calculations for a Lennard-Jones (12-6) potential with the parameters ? and ? adjusted for a best fit. The results (in atomic units) are ?=3.38×10-4 a.u., ?=7.80 a.u., for the He*+Kr system and ?=5.34×10-4 a.u. and ?=7.79 a.u. for the He*+Xe system.

K. A. Hardy and J. W. Sheldon

1984-11-01T23:59:59.000Z

423

Radial velocity distribution and line strengths of 33 carbon stars in the Galactic bulge  

SciTech Connect

This paper presents optical spectra of 33 carbon stars discovered by Azzopardi et al. (1985) in low-extinction windows to the Galactic bulge. From these spectra, the radial velocity distribution for the stars was obtained; the dispersion was found to be 113 + or - 14 km/sec (consistent with that of the bulge K and M giants) and the mean to be -44 + or - 20 km/sec. From the velocity distribution, it was found that the carbon stars do not share the kinematics of the local neighborhood and are likely to be genuine bulge members, making it possible to assign distances and accurate luminosities. Nineteen of the stars showed enhanced C-13, classifying them as J-star candidates. Two stars showed weak C2 absorption, classifying them as CS stars, and thirteen carbon stars appeared to be hydrogen-deficient. 63 refs.

Tyson, N.D.; Rich, R.M. (Columbia Univ., NY (USA))

1991-02-01T23:59:59.000Z

424

The effect of hydrogen on ultrasonic attenuation and Velocity measurements in titanium  

Science Journals Connector (OSTI)

Ultrasonic attenuation and velocity were measured in commercially pure titanium over an ultrasonic frequency range from 10 to 50 mc/s before and after heating in hydrogen. The two ultrasonic quantities changed by large amounts when the metal was heated in hydrogen at temperatures near 550°C. The main feature is that the attenuation decreased with the increasing hydrogen content. The changes induced by heating in hydrogen resulted mainly from the appearance of titaniumhydrogen phases although hydrogen in solution may also have had an effect. Similar treatment of the titanium in vacuum, oxygen, and nitrogen did not produce appreciable changes in attenuation, velocity, or microstructure. Unfortunately the use of attenuation measurement work at these frequencies is in early stages of development and no unique identification of the mechanisms involved can be given at present. As a consequence this paper is limited to discussion of the experimental observations and effects.

C.F Ying; R Truell

1954-01-01T23:59:59.000Z

425

Electron velocity distribution instability in magnetized plasma wakes and artificial electron mass  

E-Print Network (OSTI)

The wake behind a large object (such as the moon) moving rapidly through a plasma (such as the solar wind) contains a region of depleted density, into which the plasma expands along the magnetic field, transverse to the flow. It is shown here that (in addition to any ion instability) a bump-on-tail which is unstable appears on the electrons' parallel velocity distribution function because of the convective non-conservation of parallel energy. It arises regardless of any non-thermal features on the external electron velocity distribution. The detailed electron distribution function throughout the wake is calculated by integration along orbits; and the substantial energy level of resulting electron plasma (Langmuir) turbulence is evaluated quasilinearly. It peaks near the wake axis. If the mass of the electrons is artificially enhanced, for example in order to make numerical simulation feasible, then much more unstable electron distributions arise; but these are caused by the unphysical mass ratio.

Hutchinson, I H

2011-01-01T23:59:59.000Z

426

Doppler-shifted fluorescence imaging of velocity fields in supersonic reacting flows  

SciTech Connect

The application of Doppler-shifted fluorescence imaging of velocity fields in supersonic reacting flows is analyzed. Focussing on fluorescence of the OH molecule in typical H2-air Scramjet flows, the effects of uncharacterized variations in temperature, pressure, and collisional partner composition across the measurement plane are examined. Detailed measurements of the (1,0) band OH lineshape variations in H2-air combustions are used, along with single-pulse and time-averaged measurements of an excimer-pumped dye laser, to predict the performance of a model velocimeter with typical Scramjet flow properties. The analysis demonstrates the need for modification and control of the laser bandshape in order to permit accurate velocity measurements in the presence of multivariant flow properties. 13 refs.

Allen, M.G.; Davis, S.J.; Kessler, W.J.; Sonnenfroh, D.M. (Physical Sciences, Inc., Andover, MA (United States))

1992-07-01T23:59:59.000Z

427

Particle velocity based universal algorithm for numerical simulation of hydraulic fractures  

E-Print Network (OSTI)

In the paper, we propose a new effective mathematical formulation and resulting universal numerical algorithm capable of tackling various HF models in the framework of a unified approach. The presented numerical scheme is not limited to any particular elasticity model or crack propagation regime. Its basic assumptions are: i) proper choice of independent and dependent variables (with the direct utilization of a new one - the reduced particle velocity), ii) tracing the fracture front by use of the speed equation which can be integrated in a closed form and sets an explicit relation between the crack propagation speed and the coefficients in the asymptotic expansion of the crack opening, iii) proper regularization techniques, iv) improved temporal approximation, v) modular algorithm architecture. The application of the new dependent variable, the reduced particle velocity, instead of the usual fluid flow rate, facilitates the computation of the crack propagation speed from the local relation based on the speed ...

Wrobel, Michal

2014-01-01T23:59:59.000Z

428

Vectorial velocity filter for ultracold neutrons based on a surface-disordered mirror system  

Science Journals Connector (OSTI)

We perform classical three-dimensional Monte Carlo simulations of ultracold neutrons scattering through an absorbing-reflecting mirror system in the Earth's gravitational field. We show that the underlying mixed phase space of regular skipping motion and random motion due to disorder scattering can be exploited to realize a vectorial velocity filter for ultracold neutrons. The absorbing-reflecting mirror system proposed allows beams of ultracold neutrons with low angular divergence to be formed. The range of velocity components can be controlled by adjusting the geometric parameters of the system. First experimental tests of its performance are presented. One potential future application is the investigation of transport and scattering dynamics in confined systems downstream of the filter.

L. A. Chizhova; S. Rotter; T. Jenke; G. Cronenberg; P. Geltenbort; G. Wautischer; H. Filter; H. Abele; J. Burgdörfer

2014-03-10T23:59:59.000Z

429

Reverse Doppler effect of magnons with negative group velocity scattered from a moving Bragg grating  

Science Journals Connector (OSTI)

We demonstrate experimentally and theoretically the reverse Doppler effect when magnons with negative group velocity are reflected off a moving Bragg grating. This grating, which represents a moving magnonic crystal, is created in an yttrium-iron-garnet film by the periodic strain induced by a traveling surface acoustic wave. As reflection occurs from a crystal rather than from a single reflecting surface, the wave number of the scattered wave is strictly determined by a momentum conservation law. Magnons scattered from the approaching (receding) magnonic crystal are found to be shifted down (up) in frequency. This result, together with an earlier report of reverse Doppler shift from moving sources [D. D. Stancil et al., Phys. Rev. B, 74, 060404(R) (2006)], establishes that the reverse Doppler effect is a universal phenomenon in systems with negative group velocity and not restricted to left-handed materials.

A. V. Chumak; P. Dhagat; A. Jander; A. A. Serga; B. Hillebrands

2010-04-16T23:59:59.000Z

430

GAS EXCITATION IN ULIRGs: MAPS OF DIAGNOSTIC EMISSION-LINE RATIOS IN SPACE AND VELOCITY  

SciTech Connect

Emission-line spectra extracted at multiple locations across 39 ultraluminous infrared galaxies have been compiled into a spectrophotometric atlas. Line profiles of H{alpha}, [N II], [S II], [O I], H{beta}, and [O III] are resolved and fit jointly with common velocity components. Diagnostic ratios of these line fluxes are presented in a series of plots, showing how the Doppler shift, line width, gas excitation, and surface brightness change with velocity at fixed position and also with distance from the nucleus. One general characteristic of these spectra is the presence of shocked gas extending many kiloparsecs from the nucleus. In some systems, the rotation curves of the emitting gas indicate motions that suggest gas disks, which are most frequent at early merger stages. At these early merger stages, the emission line ratios indicate the presence of shocked gas, which may be triggered by the merger event. We also report the general characteristics of the integrated spectra.

Soto, Kurt T.; Martin, Crystal L. [Physics Department, University of California, Santa Barbara, CA 93106-9530 (United States)

2012-11-15T23:59:59.000Z

431

Shift in the longitudinal sound velocity due to sliding charge-density waves  

Science Journals Connector (OSTI)

The nonlinear conductivity observed for moderate electric fields in NbSe3, TaS3, (TaS4)2I, and K0.3MoO3 below the charge-density-wave-transition is believed to be due to the sliding of the charge-density waves. The sliding motion leads to a Doppler shift of the x-ray diffraction peaks, but this effect has not yet been resolved. We show here that besides the Doppler shift, a sliding incommensurate charge-density wave causes a change in the longitudinal sound velocity of the crystal that is linear in the charge-density-wave velocity. The resulting anisotropic shift is estimated in a mean-field approximation and found to be experimentally observable.

S. N. Coppersmith and C. M. Varma

1984-09-15T23:59:59.000Z

432

Effect of electric field on heat transfer performance of automobile radiator at low frontal air velocity  

Science Journals Connector (OSTI)

The effect of electric field on the performance of automobile radiator is investigated in this work. In this experiment, a louvered fin and flat tube automobile radiator was mounted in a wind tunnel and there was heat exchange between a hot water stream circulating inside the tube and a cold air stream flowing through the external surface. The electric field was supplied on the airside of the heat exchanger and its supply voltage was adjusted from 0 kV to 12 kV. From the experiment, it was found that the unit with electric field pronounced better heat transfer rate, especially at low frontal velocity of air. The correlations for predicting the air-side heat transfer coefficient of the automobile radiator, with and without electric field, at low frontal air velocity were also developed and the predicted results agreed very well with the experimental data.

S. Vithayasai; T. Kiatsiriroat; A. Nuntaphan

2006-01-01T23:59:59.000Z

433

Technical Challenges in Low-velocity SRF Development ATLAS 25th Anniversary Celebration  

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

Challenges in Low-velocity SRF Development Challenges in Low-velocity SRF Development ATLAS 25th Anniversary Celebration October 22-23, 2010 Physics Division, Argonne National Laboratory Building 203, Auditorium Speaker: Mike Kelly ATLAS Energy Upgrade: Commissioned June 2009 14.5 MV in 5 meters using 7 SC Quarter-wave Cavities Superconductivity 1911 - superconductivity discovered by Kamerlingh Onnes in a sample of Hg at 4 Kelvin 1950's: - Ginsburg-Landau theory developed - 1957 - Bardeen, Cooper, and Schrieffer theory First applications such as SC magnets 1964 - SC resonators developed for accelerator applications at Stanford Leiden, ca. 1910 4 Outline Materials from: Ken Shepard, Joel Fuerst I. Some superconductivity background II. Progress in RF superconductivity

434

The Prevalence of Similarity of the Turbulent Wall-bounded Velocity Profile  

E-Print Network (OSTI)

In a now very influential paper, Luciano Castillo and William George used a flow governing equation approach for the outer boundary layer region to seek similarity solutions for the mean velocity and Reynolds shear stress profiles. The development led to a less-constrained version of Clauser's pressure gradient constraint parameter. Using their new pressure gradient constraint parameter equal to a constant as a search criterion, Castillo and George claim to have found many turbulent boundary layer experimental datasets that exhibited velocity profile similarity. In fact Castillo, George, and coworkers examined an extensive set of experimental datasets and claim that most turbulent boundary layers appear to be equilibrium similarity boundary layers. This is in direct contradiction to the classical belief that equilibrium similarity flows are special flows and are difficult to achieve in experiments, a contradiction that Castillo and George themselves acknowledge. The importance of this observation cannot be ov...

Weyburne, David

2014-01-01T23:59:59.000Z

435

Numerical analysis of liquid-solids suspension velocities and concentrations obtained by NMR imaging.  

SciTech Connect

Analyses of some of the steady-state, fully developed, and isothermal carrier fluid velocity and solids concentration data of Altobelli et al. and Sinton and Chow obtained using three-dimensional time-of-flight nuclear magnetic (NMR) imaging techniques are presented. NMR imaging offers powerful techniques to nonintrusively determine three-dimensional time-dependent velocity and concentration fields to assist development and validation of the constitutive models and the computer programs describing concentrated suspensions. These experiments were carefully performed and probably represent the best available open literature data of their kind. COMMIX-M, a three-dimensional transient and steady-state computer program written in Cartesian and cylindrical coordinates, has been used to analyze the NMR data. This computer program is capable of analyzing multiphase flow and heat transfer and utilizes the separate phases model wherein each phase has its own mass, momentum, and energy equations. COMMIX-M contains constitutive relationships for interfacial drag, solids viscosities and stresses to describe the solids rheology, and virtual mass and shear lift forces extended to a continuum from the single particle literature. Also included is a solids partial-slip boundary condition to allow nonzero tangential velocity at the tube walls. This computer program is being developed at Argonne National Laboratory for application to test various interphase interaction models and to predict design and processing of dense fluid-solids suspension systems. Comparisons of computed and measured concentration and velocity profiles provide some insights into the mechanisms governing the observed phenomena. Recommendations for model improvement are given. To the authors knowledge, these are the first such comparisons of theory and experiment

Ding, J.; Lyczkowski, R. W.; Sha, W. T.; Altobelli, S. A.; Fukushima, E.; Lovelace Medical Foundation

1993-01-01T23:59:59.000Z

436

Analysis of liquid-solids suspension velocities and concentrations obtained by NMR imaging  

SciTech Connect

COMMIX-M, a three-dimensional transient and steady-state computer program written in Cartesian and cylindrical coordinates, has been developed by Argonne National Laboratory. This computer program is capable of analyzing multiphase flow and heat transfer and utilizes the separate phases model wherein each phase has its own mass, momentum, and energy equations. This computer program is in its early stages of development for application to test various interphase interaction models and to predict design and processing of dense fluid-solids suspension systems. COMMIX-M contains preliminary constitutive relationships for interfacial drag, solids viscosities and stresses to describe the solids rheology, and shear lift forces from the literature. Also included is a solids partial slip boundary condition to allow non-zero tangential velocity at the tube walls. Analyses of some of the steady-state, fully-developed isothermal carrier fluid velocity and solids concentration data of Altobelli et al. and Sinton and Chow are presented. These experimental data obtained using three-dimensional time-of-flight nuclear magnetic (NMR) imaging techniques were carefully performed and represent some of the best available open literature data of their kind. NMR imaging offers powerful techniques to non-intrusively determine three-dimensional time-dependent velocity and concentration fields to assist development and validation of the constitutive models and the computer programs describing concentrated suspensions. Analyses of these NMR data, together with comparisons of computed and measured concentration and velocity profiles provide some insights into the mechanisms governing the observed phenomena. Recommendations for future research are given. To the authors` knowledge, these are the first such comparisons of theory and experiment.

Ding, J.; Lyczkowski, R.W.; Sha, W.T. [Argonne National Lab., IL (United States); Altobelli, S.A.; Fukushima, E. [Lovelace Medical Foundation, Albuquerque, NM (United States)

1992-09-01T23:59:59.000Z

437

Analysis of liquid-solids suspension velocities and concentrations obtained by NMR imaging  

SciTech Connect

COMMIX-M, a three-dimensional transient and steady-state computer program written in Cartesian and cylindrical coordinates, has been developed by Argonne National Laboratory. This computer program is capable of analyzing multiphase flow and heat transfer and utilizes the separate phases model wherein each phase has its own mass, momentum, and energy equations. This computer program is in its early stages of development for application to test various interphase interaction models and to predict design and processing of dense fluid-solids suspension systems. COMMIX-M contains preliminary constitutive relationships for interfacial drag, solids viscosities and stresses to describe the solids rheology, and shear lift forces from the literature. Also included is a solids partial slip boundary condition to allow non-zero tangential velocity at the tube walls. Analyses of some of the steady-state, fully-developed isothermal carrier fluid velocity and solids concentration data of Altobelli et al. and Sinton and Chow are presented. These experimental data obtained using three-dimensional time-of-flight nuclear magnetic (NMR) imaging techniques were carefully performed and represent some of the best available open literature data of their kind. NMR imaging offers powerful techniques to non-intrusively determine three-dimensional time-dependent velocity and concentration fields to assist development and validation of the constitutive models and the computer programs describing concentrated suspensions. Analyses of these NMR data, together with comparisons of computed and measured concentration and velocity profiles provide some insights into the mechanisms governing the observed phenomena. Recommendations for future research are given. To the authors' knowledge, these are the first such comparisons of theory and experiment.

Ding, J.; Lyczkowski, R.W.; Sha, W.T. (Argonne National Lab., IL (United States)); Altobelli, S.A.; Fukushima, E. (Lovelace Medical Foundation, Albuquerque, NM (United States))

1992-09-01T23:59:59.000Z

438

Relativistic velocity addition law derived from a machine gun analogy and time dilation only  

E-Print Network (OSTI)

We consider a scenario that involves a machine gun, the bullets it fires and a moving target, considered from the rest frame of the machine gun and from the rest frame of the target respectively. Involving the special relativity via its two postulates and the time dilation formula we derive the relativistic velocity addition law showing that it leads to the Lorentz transformations for the space-time coordinates of the same event.

Bernhard Rothenstein; Stefan Popescu

2007-03-15T23:59:59.000Z

439

Effect of Superficial Velocity on Tar from Downdraft Gasification of Biomass  

Science Journals Connector (OSTI)

Many studies, most of which used indirectly heated gasifiers and fluidized bed gasifiers, have been conducted on operational parameters such as temperature, residence time, equivalence ratio, oxygen partial pressure, and gasification medium. ... 18 Superficial velocity (SV), which increases with airflow rate, is independent of gasifier size and permits comparison of gasifiers of different dimensions. ... The majority (85%) of the total particulate matter (TPM) mass was identified, using SEM, as mono-sized spherical primary soot particles with diams. of 70 nm. ...

Takashi Yamazaki; Hirokazu Kozu; Sadamu Yamagata; Naoto Murao; Sachio Ohta; Satoru Shiya; Tatsuo Ohba

2005-03-22T23:59:59.000Z

440

Constraining the Mass Profiles of Stellar Systems: Schwarzschild Modeling of Discrete Velocity Datasets  

E-Print Network (OSTI)

(ABRIDGED) We present a new Schwarzschild orbit-superposition code designed to model discrete datasets composed of velocities of individual kinematic tracers in a dynamical system. This constitutes an extension of previous implementations that can only address continuous data in the form of (the moments of) velocity distributions, thus avoiding potentially important losses of information due to data binning. Furthermore, the code can handle any combination of available velocity components, i.e., only line-of-sight velocities, only proper motions, or a combination of both. It can also handle a combination of discrete and continuous data. The code finds the distribution function (DF, a function of the three integrals of motion E, Lz, and I3) that best reproduces the available kinematic and photometric observations in a given axisymmetric gravitational potential. The fully numerical approach ensures considerable freedom on the form of the DF f(E,Lz,I3). This allows a very general modeling of the orbital structure, thus avoiding restrictive assumptions about the degree of (an)isotropy of the orbits. We describe the implementation of the discrete code and present a series of tests of its performance based on the modeling of simulated datasets generated from a known DF. We find that the discrete Schwarzschild code recovers the original orbital structure, M/L ratios, and inclination of the input datasets to satisfactory accuracy, as quantified by various statistics. The code will be valuable, e.g., for modeling stellar motions in Galactic globular clusters, and those of individual stars, planetary nebulae, or globular clusters in nearby galaxies. This can shed new light on the total mass distributions of these systems, with central black holes and dark matter halos being of particular interest.

Julio Chanamé; Jan Kleyna; Roeland van der Marel

2008-04-21T23:59:59.000Z

Note: This page contains sample records for the topic "high velocity sdhv" 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

Full-field velocity measurements of single and two phase flows using digital pulsed laser velocimetry  

E-Print Network (OSTI)

considered to be based upon qualitative rather that quantitative foundations (Adrian & Landreth 1988). As a direct result of the limitations associated with many of the previously discussed methodologies, the technique of PLV has emerged and advanced... numbers than those currently attainable with numerical solutions and less sophisticated experimental methods (Adrian 1989). Although the PLV method generally measures two dimensional velocity vectors in two dimensional flow domains, extensions to three...

Canaan, Robert Ernst

2012-06-07T23:59:59.000Z

442

Bifractality of the Devil’s staircase appearing in the Burgers equation with Brownian initial velocity  

E-Print Network (OSTI)

Submitted to J. Stat. Phys. It is shown that the inverse Lagrangian map for the solution of the Burgers equation (in the inviscid limit) with Brownian initial velocity presents a bifractality (phase transition) similar to that of the Devil’s staircase for the standard triadic Cantor set. Both heuristic and rigorous derivations are given. It is explained why artifacts can easily mask this phenomenon in numerical simulations. 1

E. Aurell; U. Frisch; A. Noullez; M. Blank

1997-01-01T23:59:59.000Z

443

Interrelationships between air velocity and natural wet-bulb thermometer response  

E-Print Network (OSTI)

INTERRELATIONSHIPS BETWEEN AIR VFLOCITY ANO NATURAL WET-BULB THERMOMETER RESPONSE A Thesis by NATHAN GLENN JONES Submitted to the Graduate Colleqe of Texas ASM University i n partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE AUGUST 1983 Major Subject: Industrial Hygiene INTERRELATIONSHIPS BETWEEN AIR VELOCITY AND NATURAL WET-BULB THERMOMETER RESPONSE A Thesis by NATHAN GLENN JONES Approved as to style an content by: airman o ommittee er Member ~~' A~ Member...

Jones, Nathan Glenn

1983-01-01T23:59:59.000Z

444

The Art and Science in Modeling the Pressure-Velocity Interactions  

E-Print Network (OSTI)

. The figure is for a plane strain case(? = 0). The instability coefficient measures the growth of modal kinetic energy. Thus, a positive value indicates growth and a negative value indicates decay. . . . . . . . . . . . . . . . . . . . 44 2.8 A schematic...) The evolution of the diagonal components of the rapid pressure strain correlation tensor for the case of plane strain. pi33,???; picc,?. . . . . . . . 45 2.10 The figure illustrates the migration of the eigen-directions of the mean velocity gradient tensor...

Mishra, Aashwin A

2014-08-04T23:59:59.000Z

445

Impact of Filtration Velocities and Particulate Matter Characteristics on Diesel Particulate Filter Wall Loading Performance  

SciTech Connect

The impact of different types of diesel particulate matter (PM) and different sampling conditions on the wall deposition and early soot cake build up within diesel particulate filters has been investigated. The measurements were made possible by a newly developed Diesel Exhaust Filtration Analysis (DEFA) system in which in-situ diesel exhaust filtration can be reproduced with in small cordierite wafer disks, which are essentially thin sections of a Diesel Particulate Filter (DPF) wall. The different types of PM were generated from selected engine operating conditions of a single-cylinder heavy-duty diesel engine. Two filtration velocities 4 and 8 cm/s were used to investigate PM deep-bed filtration processes. The loaded wafers were then analyzed in a thermal mass analyzer that measures the Soluble Organic Fraction (SOF) as well as soot and sulfate fractions of the PM. In addition, the soot residing in the wall of the wafer was examined under an optical microscope illuminated with Ultraviolet light and an Environmental Scanning Electron Microscope (E-SEM) to determine the bulk soot penetration depth for each loading condition. It was found that higher filtration velocity results in higher wall loading with approximately the same penetration depth into the wall. PM characteristics impacted both wall loading and soot cake layer characteristics. Results from imaging analysis indicate that soot the penetration depth into the wall was affected more by PM size (which changes with engine operating conditions) rather than filtration velocity.

Lance, Michael J [ORNL; Walker, Larry R [ORNL; Yapaulo, Renato A [ORNL; Orita, Tetsuo [ORNL; Wirojsakunchai, Ekathai [University of Wisconsin; Foster, David [University of Wisconsin; Akard, Michael [Horiba Instruments Inc.

2009-01-01T23:59:59.000Z

446

A derived variable physical photon velocity explains the apparent accelerated universe without invoking dark energy  

E-Print Network (OSTI)

We have derived a group of new coordinate systems which covariantly transform from an open RW system constrained by the requirement that their spatial points move at a negative radial velocity when measured with the RW coordinates and whose clocks are attached to the transformed spatial coordinates. At their origin they all have the same time-variable photon velocity v(t), as determined by clocks and rulers which are physical when v(t) equals c(t), the physical photon velocity. A variable c(t) no longer keeps the Lorentz transform invariant. Instead, locally we have a generalized Lorentz transform and generalized Minkowski metric. By introducing a generalized time for which the differential is c(t)dt, we create a Minkowski metric in order to use Einstein's field equations to calculate c(t). Measurements of the fine structure in clouds of cosmic matter experimentally demonstrate that some physical "constant" do change with cosmic time. We use dependences on c(t) of various physical "constant" which keep a norm...

Fletcher, R C

2003-01-01T23:59:59.000Z

447

IS IGR J11014-6103 A PULSAR WITH THE HIGHEST KNOWN KICK VELOCITY?  

SciTech Connect

We report on Chandra X-ray and Parkes radio observations of IGR J11014-6103, which is a possible pulsar wind nebula with a complex X-ray morphology and a likely radio counterpart. With the superb angular resolution of Chandra, we find evidence that a portion of the extended emission may be related to a bow shock due to the putative pulsar moving through the interstellar medium. The inferred direction of motion is consistent with IGR J11014-6103 having been born in the event that produced the supernova remnant (SNR) MSH 11-61A. If this association is correct, then previous constraints on the expansion of MSH 11-61A imply a transverse velocity for IGR J11014-6103 of 2400-2900 km s{sup -1}, depending on the SNR model used. This would surpass the kick velocities of any known pulsars and rival or surpass the velocities of any compact objects that are associated with SNRs. While it is important to confirm the nature of the source, our radio pulsation search did not yield a detection.

Tomsick, John A.; Bodaghee, Arash; Fornasini, Francesca [Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450 (United States); Rodriguez, Jerome; Chaty, Sylvain [AIM-Astrophysique Interactions Multi-echelles (UMR 7158 CEA/CNRS/Universite Paris 7 Denis Diderot), CEA Saclay, DSM/IRFU/Service d'Astrophysique, Bat. 709, L'Orme des Merisiers, FR-91 191 Gif-sur-Yvette Cedex (France); Camilo, Fernando [Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, New York, NY 10027-6601 (United States); Rahoui, Farid, E-mail: jtomsick@ssl.berkeley.edu [Astronomy Department, Harvard University, 60 Garden Street, Cambridge, MA 02138 (United States)

2012-05-10T23:59:59.000Z

448

Thermal conduction by dark matter with velocity and momentum-dependent cross-sections  

E-Print Network (OSTI)

We use the formalism of Gould and Raffelt to compute the dimensionless thermal conduction coefficients for scattering of dark matter particles with standard model nucleons via cross-sections that depend on the relative velocity or momentum exchanged between particles. Motivated by models invoked to reconcile various recent results in direct detection, we explicitly compute the conduction coefficients $\\alpha$ and $\\kappa$ for cross-sections that go as $v_{\\rm rel}^2$, $v_{\\rm rel}^4$, $v_{\\rm rel}^{-2}$, $q^2$, $q^4$ and $q^{-2}$, where $v_{\\rm rel}$ is the relative DM-nucleus velocity and $q$ is the momentum transferred in the collision. We find that a $v_{\\rm rel}^{-2}$ dependence can significantly enhance energy transport from the inner solar core to the outer core. The same can true for any $q$-dependent coupling, if the dark matter mass lies within some specific range for each coupling. This effect can complement direct searches for dark matter; combining these results with state-of-the-art Solar simulations should greatly increase sensitivity to certain DM models. It also seems possible that the so-called Solar Abundance Problem could be resolved by enhanced energy transport in the solar core due to such velocity- or momentum-dependent scatterings.

Aaron C. Vincent; Pat Scott

2013-11-08T23:59:59.000Z

449

Excitation of solitons by an external resonant wave with a slowly varying phase velocity  

SciTech Connect

A novel mechanism is proposed for the excitation of solitons in nonlinear dispersive media. The mechanism employs an external pumping wave with a varying phase velocity, which provides a continuous resonant excitation of a nonlinear wave in the medium. Two different schemes of a continuous resonant growth (continuous phase-locking) of the induced nonlinear wave are suggested. The first of them requires a definite time dependence of the pumping wave phase velocity and is relatively sensitive to the initial wave phase. The second employs the dynamic autoresonance effect and is insensitive to the exact time dependence of the pumping wave phase velocity. It is demonstrated analytically and numerically, for a particular example of a driven Korteweg-de Vries (KdV) equation with periodic boundary conditions, that as the nonlinear wave grows, it transforms into a soliton, which continues growing and accelerating adiabatically. A fully nonlinear perturbation theory is developed for the driven KdV equation to follow the growing wave into the strongly nonlinear regime and describe the soliton formation.

Aranson, I.; Meerson, B. [Hebrew Univ., Jerusalem (Israel). Racah Inst. of Physics; Tajima, Toshiki [Texas Univ., Austin, TX (United States)

1992-02-01T23:59:59.000Z

450

AN AFFINE-INVARIANT SAMPLER FOR EXOPLANET FITTING AND DISCOVERY IN RADIAL VELOCITY DATA  

SciTech Connect

Markov chain Monte Carlo (MCMC) proves to be powerful for Bayesian inference and in particular for exoplanet radial velocity fitting because MCMC provides more statistical information and makes better use of data than common approaches like chi-square fitting. However, the nonlinear density functions encountered in these problems can make MCMC time-consuming. In this paper, we apply an ensemble sampler respecting affine invariance to orbital parameter extraction from radial velocity data. This new sampler has only one free parameter, and does not require much tuning for good performance, which is important for automatization. The autocorrelation time of this sampler is approximately the same for all parameters and far smaller than Metropolis-Hastings, which means it requires many fewer function calls to produce the same number of independent samples. The affine-invariant sampler speeds up MCMC by hundreds of times compared with Metropolis-Hastings in the same computing situation. This novel sampler would be ideal for projects involving large data sets such as statistical investigations of planet distribution. The biggest obstacle to ensemble samplers is the existence of multiple local optima; we present a clustering technique to deal with local optima by clustering based on the likelihood of the walkers in the ensemble. We demonstrate the effectiveness of the sampler on real radial velocity data.

Hou Fengji; Hogg, David W. [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Goodman, Jonathan; Weare, Jonathan [Courant Institute of Mathematical Sciences, New York University, 251 Mercer Street, New York, NY 10012 (United States); Schwab, Christian, E-mail: fh417@nyu.edu [Department of Astronomy, Yale University, 260 Whitney Avenue, New Haven, CT 06511 (United States)

2012-02-01T23:59:59.000Z

451

High resolution laser induced fluorescence Doppler velocimetry utilizing saturated absorption spectroscopy  

SciTech Connect

A high resolution laser induced fluorescence (LIF) system has been developed to measure the flow velocity field of neutral particles in an electron-cyclotron-resonance argon plasma. The flow velocity has been determined by the Doppler shift of the LIF spectrum, which is proportional to the velocity distribution function. Very high accuracy in velocity determination has been achieved by installing a saturated absorption spectroscopy unit into the LIF system, where the absolute value and scale of laser wavelength are determined by using the Lamb dip and the fringes of a Fabry-Perot interferometer. The minimum detectable flow velocity of a newly developed LIF system is {+-}2 m/s, and this performance remains unchanged in a long-time experiment. From the radial measurements of LIF spectra of argon metastable atoms, it is found that there exists an inward flow of neutral particles associated with neutral depletion.

Aramaki, Mitsutoshi [Department of Electrical Engineering and Computer Science, Nagoya University, Nagoya 464-8603 (Japan); Ogiwara, Kohei; Etoh, Shuzo [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga 816-8580 (Japan); Yoshimura, Shinji [National Institute for Fusion Science, Toki 509-5292 (Japan); Tanaka, Masayoshi Y. [Department of Advanced Energy Engineering Science, Kyushu University, Kasuga 816-8580 (Japan)

2009-05-15T23:59:59.000Z

452

Methods for passivating silicon devices at low temperature to achieve low interface state density and low recombination velocity while preserving carrier lifetime  

DOE Patents (OSTI)

A new process has been developed to achieve a very low SiO.sub.x /Si interface state density D.sub.it, low recombination velocity S (<2 cm/s), and high effective carrier lifetime T.sub.eff (>5 ms) for oxides deposited on silicon substrates at low temperature. The technique involves direct plasma-enhanced chemical vapor deposition (PECVD), with appropriate growth conditions, followed by a photo-assisted rapid thermal annealing (RTA) process. Approximately 500-A-thick SiO.sub.x layers are deposited on Si by PECVD at 250.degree. C. with 0.02 W/cm.sup.-2 rf power, then covered with SiN or an evaporated thin aluminum layer, and subjected to a photo-assisted anneal in forming gas ambient at 350.degree. C., resulting in an interface state density D.sub.it in the range of about 1-4.times.10.sup.10 cm.sup.-2 eV.sup.-1, which sets a record for the lowest interface state density D.sub.it for PECVD oxides fabricated to date. Detailed analysis shows that the PECVD deposition conditions, photo-assisted anneal, forming gas ambient, and the presence of an aluminum layer on top of the oxides during the anneal, all contributed to this low value of interface state density D.sub.it. Detailed metal-oxide semiconductor analysis and model calculations show that such a low recombination velocity S is the result of moderately high positive oxide charge (5.times.10.sup.11 -1.times.10.sup.12 cm.sup.-2) and relatively low midgap interface state density (1.times.10.sup.10 -4.times.10.sup.10 cm.sup.-2 eV.sup.-1). Photo-assisted anneal was found to be superior to furnace annealing, and a forming gas ambient was better than a nitrogen ambient for achieving a very low surface recombination velocity S.

Chen, Zhizhang (Duluth, GA); Rohatgi, Ajeet (Marietta, GA)

1995-01-01T23:59:59.000Z

453

Measuring water velocity using DIDSON and image cross-correlation techniques  

SciTech Connect

To design or operate hydroelectric facilities for maximum power generation and minimum ecological impact, it is critical to understand the biological responses of fish to different flow structures. However, information is still lacking on the relationship between fish behavior and flow structures despite many years of research. Existing field characterization approaches conduct fish behavior studies and flow measurements separately and coupled later using statistical analysis. These types of studies, however, lack a way to determine the specific hydraulic conditions or the specific causes of the biological response. The Dual-Frequency Identification Sonar (DIDSON) has been in wide use for fish behavior studies since 1999. The DIDSON can detect acoustic targets at long ranges in dark or turbid dark water. PIV is a state-of-the-art, non-intrusive, whole-flow-field technique, providing instantaneous velocity vector measurements in a whole plane using image cross-correlating techniques. There has been considerable research in the development of image processing techniques associated with PIV. This existing body of knowledge is applicable and can be used to process the images taken by the DIDSON. This study was conducted in a water flume which is 9 m long, 1.2 m wide, and 1.2 m deep when filled with water. A lab jet flow was setup as the benchmark flow to calibrate DIDSON images. The jet nozzle was 6.35 cm in diameter and core jet velocity was 1.52 m/s. Different particles were used to seed the flow. The flow was characterized based on the results using Laser Doppler Velocimetry (LDV). A DIDSON was mounted about 5 meters away from the jet nozzle. Consecutive DIDSON images with known time delay were divided into small interrogation spots after background was subtracted. Across-correlation was then performed to estimate the velocity vector for each interrogation spot. The estimated average velocity in the core zone was comparable to that obtained using a LDV. This proof-of-principle project demonstrated the feasibility of extracting water flow velocity information from underwater DIDSON images using image cross-correlation techniques.

Deng, Zhiqun; Mueller, Robert P.; Richmond, Marshall C.

2009-08-01T23:59:59.000Z

454

Deposition Velocities of Non-Newtonian Slurries in Pipelines: Complex Simulant Testing  

SciTech Connect

One of the concerns expressed by the External Flowsheet Review Team (EFRT) is about the potential for pipe plugging at the Waste Treatment and Immobilization Plant (WTP). Per the review’s executive summary, “Piping that transports slurries will plug unless it is properly designed to minimize this risk. This design approach has not been followed consistently, which will lead to frequent shutdowns due to line plugging.” To evaluate the potential for plugging, deposition-velocity tests were performed on several physical simulants to determine whether the design approach is conservative. Deposition velocity is defined as the velocity below which particles begin to deposit to form a moving bed of particles on the bottom of a straight horizontal pipe during slurry-transport operations. The deposition velocity depends on the system geometry and the physical properties of the particles and fluid. An experimental program was implemented to test the stability-map concepts presented in WTP-RPT-175 Rev. 01. Two types of simulant were tested. The first type of simulant was similar to the glass-bead simulants discussed in WTP-RPT-175 Rev. 0 ; it consists of glass beads with a nominal particle size of 150 µm in a kaolin/water slurry. The initial simulant was prepared at a target yield stress of approximately 30 Pa. The yield stress was then reduced, stepwise, via dilution or rheological modifiers, ultimately to a level of <1 Pa. At each yield-stress step, deposition-velocity testing was performed. Testing over this range of yield-stress bounds the expected rheological operating window of the WTP and allows the results to be compared to stability-map predictions for this system. The second simulant was a precipitated hydroxide that simulates HLW pretreated sludge from Hanford waste tank AZ-101. Testing was performed in a manner similar to that for the first simulant over a wide range of yield stresses; however, an additional test of net-positive suction-head required (NPSHR) was performed at each yield stress condition. Unlike the previous simulant, the sizes and densities of the particles that can deposit in the piping are a result of the simulant precipitation process; there is expected to be a complex mixture of particles of various sizes and densities that make it difficult to predict a stability map. The objective of the testing is to observe whether behavior consistent with the stability-map concept occurs in complex simulants with mixtures of different sizes and densities.

Poloski, Adam P.; Bonebrake, Michael L.; Casella, Andrew M.; Johnson, Michael D.; Toth, James J.; Adkins, Harold E.; Chun, Jaehun; Denslow, Kayte M.; Luna, Maria; Tingey, Joel M.

2009-07-01T23:59:59.000Z

455

MHL High Speed Cavitation | Open Energy Information  

Open Energy Info (EERE)

High Speed Cavitation High Speed Cavitation Jump to: navigation, search Basic Specifications Facility Name MHL High Speed Cavitation Overseeing Organization University of Michigan Hydrodynamics Hydrodynamic Testing Facility Type Channel Length(m) 0.8 Beam(m) 0.2 Depth(m) 0.2 Cost(per day) $2000(+ Labor/Materials) Towing Capabilities Towing Capabilities Yes Maximum Velocity(m/s) 25.9 Wavemaking Capabilities Wavemaking Capabilities None Channel/Tunnel/Flume Channel/Tunnel/Flume Yes Velocity(m/s) 25.9 Recirculating No Wind Capabilities Wind Capabilities None Control and Data Acquisition Description Custom Data Acquisition System using National Instruments hardware; system compatible with Planing Hull and Floating Beam Dynamometers Number of channels 16 Bandwidth(kHz) 20 Cameras Yes

456

The North Atlantic Subpolar Gyre in Four High-Resolution Models  

Science Journals Connector (OSTI)

The authors present the first quantitative comparison between new velocity datasets and high-resolution models in the North Atlantic subpolar gyre [1/10° Parallel Ocean Program model (POPNA10), Miami Isopycnic Coordinate Ocean Model (MICOM), ?° ...

A. M. Treguier; S. Theetten; E. P. Chassignet; T. Penduff; R. Smith; L. Talley; J. O. Beismann; C. Böning

2005-05-01T23:59:59.000Z

457

THE STRUCTURE OF THE BROAD-LINE REGION IN ACTIVE GALACTIC NUCLEI. I. RECONSTRUCTED VELOCITY-DELAY MAPS  

SciTech Connect

We present velocity-resolved reverberation results for five active galactic nuclei. We recovered velocity-delay maps using the maximum entropy method for four objects: Mrk 335, Mrk 1501, 3C 120, and PG 2130+099. For the fifth, Mrk 6, we were only able to measure mean time delays in different velocity bins of the H{beta} emission line. The four velocity-delay maps show unique dynamical signatures for each object. For 3C 120, the Balmer lines show kinematic signatures consistent with both an inclined disk and infalling gas, but the He II {lambda}4686 emission line is suggestive only of inflow. The Balmer lines in Mrk 335, Mrk 1501, and PG 2130+099 show signs of infalling gas, but the He II emission in Mrk 335 is consistent with an inclined disk. We also see tentative evidence of combined virial motion and infalling gas from the velocity-binned analysis of Mrk 6. The maps for 3C 120 and Mrk 335 are two of the most clearly defined velocity-delay maps to date. These maps constitute a large increase in the number of objects for which we have resolved velocity-delay maps and provide evidence supporting the reliability of reverberation-based black hole mass measurements.

Grier, C. J.; Peterson, B. M.; Pogge, R. W.; De Rosa, G.; Martini, Paul; Kochanek, C. S.; Zu, Y.; Shappee, B.; Beatty, T. G.; Salvo, C. Araya; Bird, J. C. [Department of Astronomy, The Ohio State University, 140 W 18th Ave, Columbus, OH 43210 (United States)] [Department of Astronomy, The Ohio State University, 140 W 18th Ave, Columbus, OH 43210 (United States); Horne, Keith [SUPA Physics and Astronomy, University of St. Andrews, Fife, KY16 9SS Scotland (United Kingdom)] [SUPA Physics and Astronomy, University of St. Andrews, Fife, KY16 9SS Scotland (United Kingdom); Bentz, M. C. [Department of Physics and Astronomy, Georgia State University, Astronomy Offices, One Park Place South SE, Suite 700, Atlanta, GA 30303 (United States)] [Department of Physics and Astronomy, Georgia State University, Astronomy Offices, One Park Place South SE, Suite 700, Atlanta, GA 30303 (United States); Denney, K. D. [Marie Curie Fellow at the Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark)] [Marie Curie Fellow at the Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Siverd, R. [Department of Physics and Astronomy, Vanderbilt University, 5301 Stevenson Center, Nashville, TN 37235 (United States)] [Department of Physics and Astronomy, Vanderbilt University, 5301 Stevenson Center, Nashville, TN 37235 (United States); Sergeev, S. G.; Borman, G. A. [Crimean Astrophysical Observatory, P/O Nauchny Crimea 98409 (Ukraine)] [Crimean Astrophysical Observatory, P/O Nauchny Crimea 98409 (Ukraine); Kaspi, S. [School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel)] [School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Bord, D. J. [Department of Natural Sciences, The University of Michigan - Dearborn, 4901 Evergreen Rd, Dearborn, MI 48128 (United States)] [Department of Natural Sciences, The University of Michigan - Dearborn, 4901 Evergreen Rd, Dearborn, MI 48128 (United States); Che, X. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 41809 (United States)] [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 41809 (United States); and others

2013-02-10T23:59:59.000Z

458

Velocity and concentration studies of flowing suspensions by nuclear magnetic resonance imaging. Final report, October 7, 1994--October 6, 1996  

SciTech Connect

Nuclear magnetic resonance imaging techniques were developed to study concentrated suspension flows. The tasks completed were: (1) materials selection for imaging of both particle and fluid components, (2) pipe flow measurements, and (3) flows in complex geometries. The partially completed task is the development of rapid imaging techniques by analog compensation of eddy currents, generated by the gradient pulses, and real-time image reconstruction from the data. The best combination of materials found is pharmaceutical beads in silicon oil. Their relaxation times T{sub 1} are sufficiently different to permit imaging the two components separately. The pipe flow experiment used 3 mm, neutrally buoyant, plastic particles, up to 40% by volume, in 80--90W transmission oil flowing in a 5 cm diameter pipe. Distances ranging from 60 cm to 6 m downstream from a commercial mixer was studied. The flow is fully developed at 6 m and the concentration and velocity profiles agree with earlier lower resolution experiments. The eddy current compensation scheme works well for two channels and is being extended to eight channels. The authors have also built a rapid reconstruction hardware that processes and displays images in a fraction of a second. They studied the flow of neutrally buoyant concentrated suspension past a step expansion and contraction in a cylindrical pipe. Interesting transition is observed at the expansion whereby the high fluids-fraction outer layer spreads to become the outer layer in the larger pipe.

NONE

1996-12-31T23:59:59.000Z

459

Shock Waves in High-Energy Materials: The Initial Chemical Events in Nitramine RDX  

Science Journals Connector (OSTI)

We extend the reactive force field ReaxFF to describe the high energy nitramine RDX and use it with molecular dynamics (MD) to study its shock-induced chemistry. We studied shock propagation via nonequilibrium MD simulations at various collision velocities. We find that for high impact velocities (>6??km/s) the RDX molecules decompose and react to form a variety of small molecules in very short time scales (<3???ps). These products are consistent with those found experimentally at longer times. For lower velocities only NO2 is formed, also in agreement with experiments.

Alejandro Strachan; Adri C. T. van Duin; Debashis Chakraborty; Siddharth Dasgupta; William A. Goddard; III

2003-08-28T23:59:59.000Z

460

Dissociation of internal energy-selected methyl bromide ion revealed from threshold photoelectron-photoion coincidence velocity imaging  

SciTech Connect

Dissociative photoionization of methyl bromide (CH{sub 3}Br) in an excitation energy range of 10.45–16.90 eV has been investigated by using threshold photoelectron-photoion coincidence (TPEPICO) velocity imaging. The coincident time-of-flight mass spectra indicate that the ground state X{sup 2}E of CH{sub 3}Br{sup +} is stable, and both A{sup 2}A{sub 1} and B{sup 2}E ionic excited states are fully dissociative to produce the unique fragment ion of CH{sub 3}{sup +}. From TPEPICO 3D time-sliced velocity images of CH{sub 3}{sup +} dissociated from specific state-selected CH{sub 3}Br{sup +} ion, kinetic energy release distribution (KERD) and angular distribution of CH{sub 3}{sup +} fragment ion are directly obtained. Both spin-orbit states of Br({sup 2}P) atom can be clearly observed in fast dissociation of CH{sub 3}Br{sup +}(A{sup 2}A{sub 1}) ion along C–Br rupture, while a KERD of Maxwell-Boltzmann profile is obtained in dissociation of CH{sub 3}Br{sup +}(B{sup 2}E) ion. With the aid of the re-calculated potential energy curves of CH{sub 3}Br{sup +} including spin-orbit coupling, dissociation mechanisms of CH{sub 3}Br{sup +} ion in A{sup 2}A{sub 1} and B{sup 2}E states along C–Br rupture are revealed. For CH{sub 3}Br{sup +}(A{sup 2}A{sub 1}) ion, the CH{sub 3}{sup +} + Br({sup 2}P{sub 1/2}) channel is occurred via an adiabatic dissociation by vibration, while the Br({sup 2}P{sub 3/2}) formation is through vibronic coupling to the high vibrational level of X{sup 2}E state followed by rapid dissociation. C–Br bond breaking of CH{sub 3}Br{sup +}(B{sup 2}E) ion can occur via slow internal conversion to the excited vibrational level of the lower electronic states and then dissociation.

Tang, Xiaofeng [Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (China) [Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (China); National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Zhou, Xiaoguo, E-mail: xzhou@ustc.edu.cn, E-mail: yanbing@jlu.edu.cn; Liu, Shilin [Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (China) [Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Sun, Zhongfa [Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (China)] [Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (China); Liu, Fuyi; Sheng, Liusi [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China)] [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Yan, Bing, E-mail: xzhou@ustc.edu.cn, E-mail: yanbing@jlu.edu.cn [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China)] [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China)

2014-01-28T23:59:59.000Z

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461

Comparisons of computed and measured three-dimensional velocity fields in a motored two-stroke engine  

SciTech Connect

Computer simulations are compared with measurements of the three-dimensional, unsteady scavenging flows of a motored two-stroke engine. Laser Doppler velocimetry measurements were made on a modified Suzuki DT-85 ported engine. Calculations were performed using KIVA-3, a computer program that efficiently solves the intake and exhaust port flows along with those in the cylinder. Measured and computed cylinder pressures and velocities are compared. Pressures agree well over the cycle as do the velocities at the intake ports. In-cylinder velocities differ in detail, but the tumbling motion in the cylinder is well replicated in vertical plane passing through the cylinder axis. 20 refs., 7 figs., 3 tabs.

Amsden, A.A.; O'Rourke, P.J.; Butler, T.D. (Los Alamos National Lab., NM (United States)); Meintjes, K.; Fansler, T.D. (General Motors Research Labs., Warren, MI (United States))

1991-01-01T23:59:59.000Z

462

New sensor for measurement of low air flow velocity. Phase I final report  

SciTech Connect

The project described here is the Phase I feasibility study of a two-phase program to integrate existing technologies to provide a system for determining air flow velocity and direction in radiation work areas. Basically, a low air flow sensor referred to as a thermocouple flow sensor has been developed. The sensor uses a thermocouple as its sensing element. The response time of the thermocouple is measured using an existing in-situ method called the Loop Current Step Response (LCSR) test. The response time results are then converted to a flow signal using a response time-versus-flow correlation. The Phase I effort has shown that a strong correlation exists between the response time of small diameter thermocouples and the ambient flow rate. As such, it has been demonstrated that thermocouple flow sensors can be used successfully to measure low air flow rates that can not be measured with conventional flow sensors. While the thermocouple flow sensor developed in this project was very successful in determining air flow velocity, determining air flow direction was beyond the scope of the Phase I project. Nevertheless, work was performed during Phase I to determine how the new flow sensor can be used to determine the direction, as well as the velocity, of ambient air movements. Basically, it is necessary to use either multiple flow sensors or move a single sensor in the monitoring area and make flow measurements at various locations sweeping the area from top to bottom and from left to right. The results can then be used with empirical or physical models, or in terms of directional vectors to estimate air flow patterns. The measurements can be made continuously or periodically to update the flow patterns as they change when people and objects are moved in the monitoring area. The potential for using multiple thermocouple flow sensors for determining air flow patterns will be examined in Phase II.

Hashemian, H.M.; Hashemian, M.; Riggsbee, E.T. [Analysis and Measurement Services Corp., Knoxville, TN (United States)

1995-08-01T23:59:59.000Z

463

Effects of a sheared ion velocity on the linear stability of ITG modes  

SciTech Connect

The linear dispersion of the ion temperature gradient (ITG) modes, in the presence of a non uniform background ion velocity U(parallel sign) U(parallel sign)(x) ez, in the direction of the sheared equilibrium magnetic field B0 = B0(x) ez, has been studied in the frame of the two-fluid guiding center approximation, in slab geometry. Generally speaking, the presence of an ion flow destabilizes the oscillations. The role of the excited K-H instability is discussed.

Lontano, M.; Lazzaro, E. [Istituto di Fisica del Plasma, C.N.R., Euratom-ENEA-CNR Association, Milan (Italy); Varischetti, M. C. [Istituto di Fisica del Plasma, C.N.R., Euratom-ENEA-CNR Association, Milan (Italy); Dipartimento di Fisica, Universita degli Studi di Milano, Milan (Italy)

2006-11-30T23:59:59.000Z

464

Complex-optical-field lidar system for range and vector velocity measurement  

E-Print Network (OSTI)

Complex-optical-field lidar system for range and vector velocity measurement Shuang Gao,1,2 Maurice O’Sullivan,3 and Rongqing Hui2,* 1Department of Electronic Engineering and Information Science, University of Science and Technology of China... lidar system based on the measurement of complex optical field is demonstrated for the first time. An electro-optic in- phase/quadrature (I/Q) modulator is used in the lidar transmitter to realize carrier-suppressed complex optical field modulation...

Gao, Shuang; Sullivan, Maurice O.; Hui, Rongqing

2012-11-01T23:59:59.000Z

465

Reciprocal Collision Avoidance with Acceleration-Velocity Obstacles Jur van den Berg Jamie Snape Stephen J. Guy Dinesh Manocha  

E-Print Network (OSTI)

Reciprocal Collision Avoidance with Acceleration-Velocity Obstacles Jur van den Berg Jamie Snape at Chapel Hill, USA. E-mail: {berg, snape, sjguy, dm}@cs.unc.edu. Website with videos: http

van den Berg, Jur

466

Prediction of a non-uniform freestream velocity distribution for counterrotating propeller configurations and the effect on performance/acoustic  

E-Print Network (OSTI)

aerodynamic loads which are combined with the propeller geometry to predict the radiated acoustics. The effect of the non-uniform freestream velocity distribution on counterrotating propeller design and analysis is shown as well as comparisons with flight...

Allen, Christopher Shane

2012-06-07T23:59:59.000Z

467

Some Comments About Correlations Between Magnetic Field and Velocity, Magnetic Field and Line Intensity in the Undisturbed Photosphere  

Science Journals Connector (OSTI)

Test cross-correlation functions between the magnetic field recordings and the sight-line velocity recordings with East and West relative ... the deviations of the absolute value of the magnetic-field strength |H

G. Y. Vassilyeva; A. K. Tchandaev

1968-01-01T23:59:59.000Z

468

Green's Functions for Surface Waves in a Generic Velocity Structure 1 Victor C. Tsai and Sarun Atiganyanun* 3  

E-Print Network (OSTI)

1 Green's Functions for Surface Waves in a Generic Velocity Structure 1 and Green's functions have been well established 14 for many decades. However, or Green's function surface displacement. We address this gap in the 19 literature

469

Analytic theory for the determination of velocity and stability of bubbles in a Hele-Shaw cell  

Science Journals Connector (OSTI)

Here, we extend the analysis of Part I to determine the linear stability of a bubble in a Hele-Shaw cell analytically. Only ... the solution branch corresponding to the largest possible bubble velocity U for give...

S. Tanveer

1989-05-01T23:59:59.000Z

470

Images of the lines under the MS transformations and the Concept of Velocity in the DSR theories  

E-Print Network (OSTI)

The effect of the Maguejo-Smolin (MS) transformations on a straight line in the energy- momentum space will be studied. We will interpret the slope of this line as velocity $dE/dp$, which can leads to addition rule for the velocities in the MS doubly special relativity (DSR) case. Relation between two expressions $dE/dp$ and $p/E$ for velocity in the momentum space will be investigated more and the energy dependency of the velocities in the DSR theories is related to the geometrical properties of the lines under DSR transformations. The images of two parallel lines under the MS transformations will be studied and we will compute crossing point of these lines under the MS transformations in the energy-momentum space. The linear-fractional transformations don't keep parallelism. The crossing point is on a line in the energy-momentum space with a constant momentum $E_p/c$.

Jafari, Nosrtollah

2015-01-01T23:59:59.000Z

471

Images of the lines under the MS transformations and the Concept of Velocity in the DSR theories  

E-Print Network (OSTI)

The effect of the Maguejo-Smolin (MS) transformations on a straight line in the energy- momentum space will be studied. We will interpret the slope of this line as velocity $dE/dp$, which can leads to addition rule for the velocities in the MS doubly special relativity (DSR) case. Relation between two expressions $dE/dp$ and $p/E$ for velocity in the momentum space will be investigated more and the energy dependency of the velocities in the DSR theories is related to the geometrical properties of the lines under DSR transformations. The images of two parallel lines under the MS transformations will be studied and we will compute crossing point of these lines under the MS transformations in the energy-momentum space. The linear-fractional transformations don't keep parallelism. The crossing point is on a line in the energy-momentum space with a constant momentum $E_p/c$.

Nosrtollah Jafari

2015-01-30T23:59:59.000Z

472

THE USE OF RADIAL VELOCITY DERIVATIVE TO DIAGNOSE ROTATION AND DIVERGENCE Travis M. Smith1,2, *  

E-Print Network (OSTI)

P5.6 THE USE OF RADIAL VELOCITY DERIVATIVE TO DIAGNOSE ROTATION AND DIVERGENCE Travis M. Smith1 was implemented in NSSL's Damaging Downburst Prediction and Detection Algorithm (Smith et al. 2004) for detecting

Smith, Travis

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