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Note: This page contains sample records for the topic "wave velocity variations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

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

Open Energy Info (EERE)

P wave velocity variations in the Coso region, California, derived from local earthquake travel times Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal...

2

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

3

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

4

Temporal Velocity Variations beneath the Coso Geothermal Field...  

Open Energy Info (EERE)

events and determine the compressional and shear wave velocity as well as their ratio. In a first step, we apply traveltime tomography based on the observed microearthquake...

5

On the Diurnal Variation of Mountain Waves  

Science Conference Proceedings (OSTI)

The diurnal variation of mountain waves and wave drag associated with flow past mesoscale ridges has been examined using the Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS) and an analytical boundary layer (BL) model. The wave drag ...

Qingfang Jiang; James D. Doyle

2008-04-01T23:59:59.000Z

6

Mass Transport Velocity in Free Barotropic Poincaré Waves  

Science Conference Proceedings (OSTI)

The mass transport velocity induced by long surface waves in a shallow, rotating viscous ocean is studied theoretically by using a Lagrangian description of motion. The depth is constant, and the water is homogeneous. Such waves are referred to ...

Frode Høydalsvik; Jan Erik Weber

2003-09-01T23:59:59.000Z

7

On the Structure of the Velocity Field over Progressive Mechanically-Generated Water Waves  

Science Conference Proceedings (OSTI)

The structure of the velocity field over a propagating wave of fixed frequency is examined. The vertical and horizontal velocities were measured in a transformed Eulerian wave-following frame of reference in a wind-wave research facility at ...

Yiannis Alex Papadimitrakis; En Yun Hsu; Robert L. Street

1984-12-01T23:59:59.000Z

8

Detonation wave velocity and curvature of brass encased PBXN-111  

Science Conference Proceedings (OSTI)

Detonation velocities and wave front curvatures were measured for PBXN-111 charges encased in 5 mm thick brass tubes. In all the experiments (charge diameters from 19 to 47 mm) the brass case affected the detonation properties of PBXN-111. Steady detonation waves propagated in brass encased charges with diameters as small as 19 mm, which is about half of the unconfined failure diameter. The radii of curvature of the detonation waves at the center of the wave fronts ranged from 52 to 141 mm for charge diameters of 25 to 47 mm. The angles between the detonation wave fronts and the brass/charge interfaces were between 72 and 74 degrees. {copyright} {ital 1996 American Institute of Physics.}

Forbes, J.W.; Lemar, E.R. [Naval Surface Warfare Center, Indian Head Division, Silver Spring, Maryland 20903-5640 (United States)

1996-05-01T23:59:59.000Z

9

Interannual Variations of Total Ozone and Their Relationship to Variations of Planetary Wave Activity  

Science Conference Proceedings (OSTI)

Interannual variations of total ozone at midlatitudes of the Northern Hemisphere are shown to operate coherently with variations of upwelling planetary wave activity from the troposphere. Variations of upwelling wave activity, which modulate ...

Andrew C. Fusco; Murry L. Salby

1999-06-01T23:59:59.000Z

10

Longshore sediment transport rate calculated incorporating wave orbital velocity fluctuations  

E-Print Network (OSTI)

Laboratory experiments were performed to study and improve longshore sediment transport rate predictions. Measured total longshore transport in the laboratory was approximately three times greater for plunging breakers than spilling breakers. Three distinct zones of longshore transport were observed across the surf zone: the incipient breaker zone, inner surf zone, and swash zone. Transport at incipient breaking was influenced by breaker type; inner surf zone transport was dominated by wave height, independent of wave period; and swash zone transport was dependent on wave period. Selected predictive formulas to compute total load and distributed load transport were compared to laboratory and field data. Equations by Kamphuis (1991) and Madsen et al. (2003) gave consistent total sediment transport estimates for both laboratory and field data. Additionally, the CERC formula predicted measurements well if calibrated and applied to similar breaker types. Each of the distributed load models had shortcomings. The energetics model of Bodge and Dean (1987) was sensitive to fluctuations in energy dissipation and often predicted transport peaks that were not present in the data. The Watanabe (1992) equation, based on time-averaged bottom stress, predicted no transport at most laboratory locations. The Van Rijn (1993) model was comprehensive and required hydrodynamic, bedform, and sediment data. The model estimated the laboratory cross-shore distribution well, but greatly overestimated field transport. Seven models were developed in this study based on the principle that transported sediment is mobilized by the total shear stress acting on the bottom and transported by the current at that location. Shear stress, including the turbulent component, was calculated from the wave orbital velocity. Models 1 through 3 gave good estimates of the transport distribution, but underpredicted the transport peak near the plunging wave breakpoint. A suspension term was included in Models 4 through 7, which improved estimates near breaking for plunging breakers. Models 4, 5 and 7 also compared well to the field measurements. It was concluded that breaker type is an important variable in determining the amount of transport that occurs at a location. Lastly, inclusion of the turbulent component of the orbital velocity is vital in predictive sediment transport equations.

Smith, Ernest Ray

2006-08-01T23:59:59.000Z

11

Effects of Wave Breaking on the Near-Surface Profiles of Velocity and Turbulent Kinetic Energy  

Science Conference Proceedings (OSTI)

A theoretical model for the near-surface velocity profile in the presence of breaking waves is presented. Momentum is accumulated by growing waves and is released upon wave breaking. In effect, such a transition is a process involving a time-...

Arne Melsom; Øyvind SÆtra

2004-02-01T23:59:59.000Z

12

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

Science Conference Proceedings (OSTI)

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

Ira Leifer; Ranjan K. Patro; Peter Bowyer

2000-10-01T23:59:59.000Z

13

Effects of CO/sub 2/ flooding on wave velocities in rocks with hydrocarbons  

SciTech Connect

Compressional and shear-wave velocities were measured in the laboratory in seven sandstones (porosities ranging from 6 to 29%) and one unconsolidated sand (37% porosity) saturated with n-hexadecane (C/sub 16/H/sub 34/) both before and after CO/sub 2/ flooding. CO/sub 2/ flooding decreased compressional-wave velocities significantly, while shear-wave velocities were less affected. The magnitude of these effects was found to depend on confining and pore pressures, temperature, and porosities of the rocks. The experimental results and theoretical analysis show that the decreases in compressional-wave velocities caused by CO/sub 2/ flooding may be seismically resolvable in situ. Therefore, seismic--especially high-frequency, high-resolution seismic--methods may be useful in mapping and locating CO/sub 2/ zones, tracking movements of CO/sub 2/ fronts, and monitoring flooding processes in reservoirs undergoing CO/sub 2/ flooding.

Wang, Z. (Core Labs., Calgary (CA)); Nur, A.M. (Stanford Univ., Geophysics Dept., CA (US))

1989-11-01T23:59:59.000Z

14

The upper crustal P-wave velocity structure of Newberry volcano, Central Oregon.  

E-Print Network (OSTI)

?? The upper-crustal seismic-velocity structure of Newberry volcano, central Oregon, is imaged using P-wave travel time tomography. The inversion combines a densely-spaced seismic line collected… (more)

Beachly, Matthew William

2011-01-01T23:59:59.000Z

15

The Upper Crustal P-wave Velocity Structure of Newberry Volcano, Central Oregon.  

E-Print Network (OSTI)

??The upper-crustal seismic-velocity structure of Newberry volcano, central Oregon, is imaged using P-wave travel time tomography. The inversion combines a densely-spaced seismic line collected in… (more)

Beachly, Matthew William, 1986-

2011-01-01T23:59:59.000Z

16

Sources of Gravity Wave Activity Seen in the Vertical Velocities Observed by the Flatland VHF Radar  

Science Conference Proceedings (OSTI)

Observations of vertical velocity made with the Flatland VHF radar located in the extremely flat terrain near Champaign, Illinois, are used to study sources of enhanced variance. The variance is used as an indicator of gravity wave activity. In ...

G. D. Nastrom; M. R. Peterson; J. L. Green; K. S. Gage; T. E. VanZandt

1990-08-01T23:59:59.000Z

17

Effect of an Insoluble Surface Film on the Drift Velocity of Capillary–Gravity Waves  

Science Conference Proceedings (OSTI)

The drift velocity due to capillary-gravity waves in a deep ocean is investigated theoretically. The surface is covered by an insoluble, inextensible film, and the analysis is based an a Lagrangian description of motion. Attenuated as well as ...

Jan Erik Weber; Even Førland

1989-07-01T23:59:59.000Z

18

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.

19

Measurements of plasma temperature in indirect drive targets from the shock wave velocity in aluminum in the Iskra-5 facility  

Science Conference Proceedings (OSTI)

Results are presented from the development of a method for measuring plasma temperature in indirect (X-ray) drive targets by recording the shock wave velocity in the Iskra-5 facility. The samples under investigation were irradiated by X-rays in a converter box, and the shock wave velocity was determined from the time at which the wave reached the back surface of the sample and the surface began to emit visible radiation. This emission, in turn, was detected by a streak camera. The results of experiments on the interaction of X radiation with a hot dense plasma, as well as the accompanying gas-dynamic processes in aluminum samples, are analyzed both theoretically and numerically. In experiments with Al and Pb samples, the shock wave velocity was measured to vary in the range U = 8-35 km/s, and the range of variation of the temperature of the box walls was measured to be T{sub e} = 140-170 eV.

Vatulin, V. V.; Zhidkov, N. V.; Kravchenko, A. G.; Kuznetsov, P. G.; Litvin, D. N.; Mis'ko, V. V.; Pinegin, A. V.; Pleteneva, N. P.; Senik, A. V.; Starodubtsev, K. V.; Tachaev, G. V. [Russian Federal Nuclear Center, All-Russia Research Institute of Experimental Physics (Russian Federation)

2010-05-15T23:59:59.000Z

20

Effect of temperature on wave velocities in sands and sandstones with heavy hydrocarbons  

SciTech Connect

A laboratory investigation was made of the effects of temperature on wave velocities in sandstones and unconsolidated sand saturated with heavy hydrocarbons. The large decreases of the compressional and shear velocities in such sandstones and sand with increasing temperature suggest that seismic methods may be very useful in detecting heat fronts in heavy hydrocarbon reservoirs undergoing steamflooding or in-situ combustion.

Wang, Z.; Nur, A.

1988-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "wave velocity variations" 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

Electromagnetic plane waves with negative phase velocity in charged black strings  

SciTech Connect

We investigate the propagation regions of electromagnetic plane waves with negative phase velocity in the ergosphere of static charged black strings. For such a propagation, some conditions for negative phase velocity are established that depend on the metric components and the choice of the octant. We conclude that these conditions remain unaffected by the negative values of the cosmological constant.

Sharif, M., E-mail: msharif.math@pu.edu.pk; Manzoor, R., E-mail: rubabmanzoor9@yahoo.com [University of the Punjab, Department of Mathematics (Pakistan)

2013-02-15T23:59:59.000Z

22

Effect of wave boundary layer on sea-to-air dimethylsulfide transfer velocity during typhoon passage  

E-Print Network (OSTI)

: Dimethylsulfide; Sea-to-air gas transfer velocity; Wave boundary layer; Tropical cyclone; Drag coefficient in order to accurately calculate aerosol radiative forcing. The sea-to-air DMS flux depends on airside coefficient CD and roughness length z0 has been investigated over small areas of the sea or in wave tanks

Chu, Peter C.

23

On the Group-Velocity Property for Wave-Activity Conservation Laws  

Science Conference Proceedings (OSTI)

The density and the flux of wave-activity conservation laws are generally required to satisfy the group-velocity property: under the WKB approximation (i.e., for nearly monochromatic small-amplitude waves in a slowly varying medium), the flux ...

J. Vanneste; T. G. Shepherd

1998-03-01T23:59:59.000Z

24

Group velocity of extraordinary waves in superdense magnetized quantum plasma with spin-1/2 effects  

Science Conference Proceedings (OSTI)

Based on the one component plasma model, a new dispersion relation and group velocity of elliptically polarized extraordinary electromagnetic waves in a superdense quantum magnetoplasma are derived. The group velocity of the extraordinary wave is modified due to the quantum forces and magnetization effects within a certain range of wave numbers. It means that the quantum spin-1/2 effects can reduce the transport of energy in such quantum plasma systems. Our work should be of relevance for the dense astrophysical environments and the condensed matter physics.

Li Chunhua; Ren Haijun; Yang Weihong [Department of Modern Physics, University of Science and Technology of China, 230026 Hefei (China); Wu Zhengwei [Department of Modern Physics, University of Science and Technology of China, 230026 Hefei (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong)

2012-12-15T23:59:59.000Z

25

Shear wave velocities from noise correlation at local scale  

Science Conference Proceedings (OSTI)

Cross correlations of ambient seismic noise recordings have been studied to infer shear seismic velocities with depth. Experiments have been done in the crowded and noisy historical centre of Napoli over inter-station distances from 50 m to about 400 m, whereas active seismic spreadings are prohibitive, even for just one receiver. Group velocity dispersion curves have been extracted with FTAN method from the noise cross correlations and then the non linear inversion of them has resulted in Vs profiles with depth. The information of near by stratigraphies and the range of Vs variability for samples of Neapolitan soils and rocks confirms the validity of results obtained with our expeditious procedure. Moreover, the good comparison of noise H/V frequency of the first main peak with 1D and 2D spectral amplifications encourages to continue experiments of noise cross-correlation. If confirmed in other geological settings, the proposed approach could reveal a low cost methodology to obtain reliable and detailed Vs velocity profiles.

De Nisco, G.; Nunziata, C. [Dipartimento di Scienze della Terra, Univ. Napoli Federico II (Italy); Vaccari, F. [Dipartimento di Scienze della Terra, Univ. Trieste (Italy); Panza, G. F. [Dipartimento di Scienze della Terra, Univ. Trieste (Italy); The Abdus Salam International Center for Theoretical Physics, ESP-SAND Group, Trieste (Italy)

2008-07-08T23:59:59.000Z

26

Velocity  

Science Conference Proceedings (OSTI)

... Delta t ffl \\Delta t = 1ns. Pulse-Dri ven Wall Motion ( ff = ... varies, can increase (!), eventually decays tozero. Pulse-Dri ven Domain Wall Velocity ( ff = ...

2004-01-16T23:59:59.000Z

27

Crust and upper mantle P wave velocity structure beneath Valles caldera, New Mexico: Results from the Jemez teleseismic tomography experiment  

Science Conference Proceedings (OSTI)

New results are presented from the teleseismic component of the Jemez Tomography Experiment conducted across Valles caldera in northern New Mexico. We invert 4872 relative {ital P} wave arrival times recorded on 50 portable stations to determine velocity structure to depths of 40 km. The three principle features of our model for Valles caldera are: (1) near-surface low velocities of {minus}17{percent} beneath the Toledo embayment and the Valle Grande, (2) midcrustal low velocities of {minus}23{percent} in an ellipsoidal volume underneath the northwest quadrant of the caldera, and (3) a broad zone of low velocities ({minus}15{percent}) in the lower crust or upper mantle. Crust shallower than 20 km is generally fast to the northwest of the caldera and slow to the southeast. Near-surface low velocities are interpreted as thick deposits of Bandelier tuff and postcaldera volcaniclastic rocks. Lateral variation in the thickness of these deposits supports increased caldera collapse to the southeast, beneath the Valle Grande. We interpret the midcrustal low-velocity zone to contain a minimum melt fraction of 10{percent}. While we cannot rule out the possibility that this zone is the remnant 1.2 Ma Bandelier magma chamber, the eruption history and geochemistry of the volcanic rocks erupted in Valles caldera following the Bandelier tuff make it more likely that magma results from a new pulse of intrusion, indicating that melt flux into the upper crust beneath Valles caldera continues. The low-velocity zone near the crust-mantle boundary is consistent with either partial melt in the lower crust or mafic rocks without partial melt in the upper mantle. In either case, this low-velocity anomaly indicates that underplating by mantle-derived melts has occurred. {copyright} 1998 American Geophysical Union

Steck, Lee K.; Fehler, Michael C.; Roberts, Peter M.; Baldridge, W. Scott; Stafford, Darrik G. [Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico (United States); Lutter, William J.; Sessions, Robert [Department of Geology and Geophysics, University of Wisconsin-Madison (United States)

1998-10-01T23:59:59.000Z

28

On Variational Methods in the Physics of Plasma Waves  

SciTech Connect

A fi rst-principle variational approach to adiabatic collisionless plasma waves is described. The focus is made on one-dimensional electrostatic oscillations, including phase-mixed electron plasma waves (EPW) with trapped particles, such as Bernstein-Greene-Kruskal modes. The well known Whitham's theory is extended by an explicit calculation of the EPW Lagrangian, which is related to the oscillation-center energies of individual particles in a periodic fi eld, and those are found by a quadrature. Some paradigmatic physics of EPW is discussed for illustration purposes. __________________________________________________

I.Y. Dodin

2013-03-08T23:59:59.000Z

29

Electromagnetic wave propagation with negative phase velocity in regular black holes  

SciTech Connect

We discuss the propagation of electromagnetic plane waves with negative phase velocity in regular black holes. For this purpose, we consider the Bardeen model as a nonlinear magnetic monopole and the Bardeen model coupled to nonlinear electrodynamics with a cosmological constant. It turns out that the region outside the event horizon of each regular black hole does not support negative phase velocity propagation, while its possibility in the region inside the event horizon is discussed.

Sharif, M., E-mail: msharif.math@pu.edu.pk; Manzoor, R., E-mail: rubabmanzoor9@yahoo.com [University of the Punjab, Department of Mathematics (Pakistan)

2012-12-15T23:59:59.000Z

30

Effect of temperature on wave velocities in sands and sandstones with heavy hydrocarbons  

SciTech Connect

A laboratory investigation was made of the effects of temperature on wave velocities in well cemented Massillon and Boise sandstones and unconsolidated Ottawa sand saturated with heavy hydrocarbons, as well as the dependence of compressional velocities in the hydrocarbons themselves as a function of temperature. The hydrocarbons selected as pore saturants were a commercial paraffin wax, 1-Eicosene, natural heavy crude, and natural tar. The experimental results show that the compressional wave velocities in the hydrocarbons decrease markedly with increasing temperature. In contrast wave velocities in the Massillon and Boise sandstones and unconsolidated Ottawa sand saturated with air or water decrease only little with increasing temperatures. The main reason for the large decreases in rocks with hydrocarbons is the melting of solid hydrocarbons, and high pore pressure. Thermal expansion of the saturants, and possibly thermal cracking of the heavy fractions and vaporization of the light fractions of the hydrocarbons may also contribute. The large decreases of the compressional and shear wave velocities in the hydrocarbon-saturated rocks and sands with temperature, suggest that seismic measurements such as used in seismology or borehole tomography may be very useful in detecting steam fronts in heavy hydrocarbon reservoirs undergoing steam flooding.

Wang, Z.; Nur, A.M.

1986-01-01T23:59:59.000Z

31

Nonlinear pulse propagation and phase velocity of laser-driven plasma waves  

Science Conference Proceedings (OSTI)

Laser evolution and plasma wave excitation by a relativistically-intense short-pulse laser in underdense plasma are investigated in the broad pulse limit, including the effects of pulse steepening, frequency red-shifting, and energy depletion. The nonlinear plasma wave phase velocity is shown to be significantly lower than the laser group velocity and further decreases as the pulse propagates owing to laser evolution. This lowers the thresholds for trapping and wavebreaking, and reduces the energy gain and efficiency of laser-plasma accelerators that use a uniform plasma profile.

Schroeder, Carl B.; Benedetti, Carlo; Esarey, Eric; Leemans, Wim

2011-03-25T23:59:59.000Z

32

On Energy Flux and Group Velocity of Waves in Baroclinic Flows  

Science Conference Proceedings (OSTI)

A modified energy flux is defined by adding a nondivergent term that involves ? to the traditional energy flux. The resultant flux, when normalized by the total eddy energy, is exactly equal to the group velocity of Rossby waves on a ? plane with ...

Edmund K. M. Chang; Isidoro Orlanski

1994-12-01T23:59:59.000Z

33

Increase of shear wave velocity before the 1998 eruption of Merapi volcano (Indonesia)  

E-Print Network (OSTI)

Increase of shear wave velocity before the 1998 eruption of Merapi volcano (Indonesia) U. Wegler,1 of the edifice of Merapi volcano (Java, Indonesia) before its eruption in 1998 by analyzing multiply scattered eruption of Merapi volcano (Indonesia), Geophys. Res. Lett., 33, L09303, doi:10.1029/2006GL025928. 1

Snieder, Roel

34

Velocity and Timing of Multiple Spherically Converging Shock Waves in Liquid Deuterium  

Science Conference Proceedings (OSTI)

The fuel entropy and required drive energy for an inertial confinement fusion implosion are set by a sequence of shocks that must be precisely timed to achieve ignition. This Letter reports measurements of multiple spherical shock waves in liquid deuterium that facilitate timing inertial confinement fusion shocks to the required precision. These experiments produced the highest shock velocity observed in liquid deuterium (U{sub s}=135 km/s at {approx}2500 GPa) and also the first observation of convergence effects on the shock velocity. Simulations model the shock-timing results well when a nonlocal transport model is used in the coronal plasma.

Boehly, T. R.; Goncharov, V. N.; Seka, W.; Hu, S. X.; Marozas, J. A. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Barrios, M. A.; Celliers, P. M.; Hicks, D. G.; Collins, G. W. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Meyerhofer, D. D. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Departments of Mechanical Engineering and Physics, University of Rochester, Rochester, New York 14623 (United States)

2011-05-13T23:59:59.000Z

35

An Adaptive Dealiasing Method Based on Variational Analysis for Radar Radial Velocities Scanned with Small Nyquist Velocities  

Science Conference Proceedings (OSTI)

Previous velocity–azimuth display (VAD)-based methods of dealiasing folded radial velocities have relied heavily on the VAD uniform-wind assumption and, thus, can fail when the uniform-wind assumption becomes poor around azimuthal circles in a ...

Qin Xu; Kang Nai

2012-12-01T23:59:59.000Z

36

Characteristics of Wave Packets in the Upper Troposphere. Part II: Seasonal and Hemispheric Variations  

Science Conference Proceedings (OSTI)

Gridded 300-hPa meridional wind data produced by the ECMWF reanalysis project were analyzed to document the seasonal and hemispheric variations in the properties of upper-tropospheric wave packets. The properties of the wave packets are mainly ...

Edmund K. M. Chang

1999-06-01T23:59:59.000Z

37

EPRI (2004, 2006) Ground-Motion Model (GMM) Review Project: Shear Wave Velocity Measurements at Seismic Recording Stations  

Science Conference Proceedings (OSTI)

This report presents the results of site characterization studies for the EPRI (2004, 2006) Ground-Motion Model Review Project. The primary purpose of this investigation was to develop S-wave velocity (VS) profiles to a depth of 30 m, or more, and to estimate the average shear wave velocity of the upper 30 m (VS30) at thirty three (33) seismic instrument sites located in the Central and Eastern United States. Results are presented in individual seismic recording station site ...

2013-04-15T23:59:59.000Z

38

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

39

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

40

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

Note: This page contains sample records for the topic "wave velocity variations" 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

High-resolution seismic tomography of compressional wave velocity structure at Newberry Volcano, Oregon Cascade Range  

SciTech Connect

Compressional wave velocity structure is determined for the upper crust beneath Newberry Volcano, central Oregon, using a high-resolution active-source seismic-tomography method. Newberry Volcano is a bimodal shield volcano east of the axis of the Cascade Range. It is associated both with the Cascade Range and with northwest migrating silicic volcanism in southeast Oregon. High-frequency (approx.7 Hz) crustal phases, nominally Pg and a midcrustal reflected phase, travel upward through a target volume beneath Newberry Volcano to a dense array of 120 seismographs. This arrangement is limited by station spacing to 1- to 2-km resolution in the upper 5 to 6 km of the crust beneath the volcano's summit caldera. The experiment tests the hypothesis that Cascade Range volcanoes are underlain only by small magma chambers. A small low-velocity anomaly delineated abosut 3 km below the summit caldera supports this hypothesis for Newberry Volcano and is interpreted as a possible magma chamber of a few to a few tens of km/sup 3/ in volume. A ring-shaped high-velocity anomaly nearer the surface coincides with the inner mapped ring fractures of the caldera. It also coincides with a circular gravity high, and we interpret it as largely subsolidus silicic cone sheets. The presence of this anomaly and of silicic vents along the ring fractures suggests that the fractures are a likely eruption path between the small magma chamber and the surface.

Achauer, U.; Evans, J.R.; Stauber, D.A.

1988-09-10T23:59:59.000Z

42

Fiber optic sensor for detecting damage location and shock wave velocity  

DOE Patents (OSTI)

This invention is comprised of a shock velocity and damage location sensor providing a means of measuring shock speed and damage location. The sensor consists of a long series of time-of-arrival `points` constructed with fiber optics. The fiber optic sensor apparatus measures shock velocity as the fiber sensor is progressively crushed as a shock wave proceeds in a direction along the fiber. The light received by a receiving means changes as time-of-arrival points are destroyed as the sensor is disturbed by the shock. The sensor may comprise a transmitting fiber bent into a series of loops and fused to a receiving fiber at various places, time-of-arrival points, along the receiving fibers length. At the `points` of contact, where a portion of the light leaves the transmitting fiber and enters the receiving fiber, the loops would be required to allow the light to travel backwards through the receiving fiber toward a receiving means. The sensor may also comprise a single optical fiber wherein the time-of-arrival points are comprised of reflection planes distributed along the fibers length. In this configuration, as the shock front proceeds along the fiber it destroys one reflector after another. The output received by a receiving means from this sensor may be a series of downward steps produced as the shock wave destroys one time-of-arrival point after another, or a nonsequential pattern of steps in the event time-of-arrival points are destroyed at any point along the sensor.

Weiss, J.D.

1993-12-31T23:59:59.000Z

43

MEASUREMENT OF COMPRESSIONAL-WAVE SEISMIC VELOCITIES IN 29 WELLS AT THE HANFORD SITE  

Science Conference Proceedings (OSTI)

Check shot seismic velocity surveys were collected in 100 B/C, 200 East, 200-PO-1 Operational Unit (OU), and the Gable Gap areas in order to provide time-depth correlation information to aid the interpretation of existing seismic reflection data acquired at the Hanford Site (Figure 1). This report details results from 5 wells surveyed in fiscal year (FY) 2008, 7 wells in FY 2009, and 17 wells in FY 2010 and provides summary compressional-wave seismic velocity information to help guide future seismic survey design as well as improve current interpretations of the seismic data (SSC 1979/1980; SGW-39675; SGW-43746). Augmenting the check shot database are four surveys acquired in 2007 in support of the Bechtel National, Inc. Waste Treatment Plant construction design (PNNL-16559, PNNL-16652), and check shot surveys in three wells to support seismic testing in the 200 West Area (Waddell et al., 1999). Additional sonic logging was conducted during the late 1970s and early 1980s as part of the Basalt Waste Isolation Program (BWIP) (SSC 1979/1980) and check shot/sonic surveys as part of the safety report for the Skagit/Hanford Nuclear project (RDH/10-AMCP-0164). Check shot surveys are used to obtain an in situ measure of compressional-wave seismic velocity for sediment and rock in the vicinity of the well point, and provide the seismic-wave travel time to geologic horizons of interest. The check shot method deploys a downhole seismic receiver (geophone) to record the arrival of seismic waves generated by a source at the ground surface. The travel time of the first arriving seismic-wave is determined and used to create a time-depth function to correlate encountered geologic intervals with the seismic data. This critical tie with the underlying geology improves the interpretation of seismic reflection profile information. Fieldwork for this investigation was conducted by in house staff during the weeks of September 22, 2008 for 5 wells in the 200 East Area (Figure 2); June 1, 2009 for 7 wells in the 200-PO-1 OU and Gable Gap regions (see Figure 3 and Figure 4); and March 22, 2010 and April 19, 2010 for 17 wells in the 200 East, The initial scope of survey work was planned for Wells 299-EI8-1, 699-2-E14, 699-12-18, 699-16-51, 699-42-30, 699-53-55B, 699-54-18D, and 699-84-34B. Well 299-E18-1 could not be entered due to bent casing (prevented removal of the pump), wells 699-12-18 and 699-42-30 could not be safely reached by the logging truck, Well 699-16-51 was decommissioned prior to survey start, Well 699-53-55B did not have its pump pulled, and Wells 699-2-EI4, 699-54-18D, and 699-84-34B are artesian and capped with an igloo structure. Table 1 provides a list of wells that were surveyed and Figure 1 through Figure 5 show the well locations relative to the Hanford Site.

PETERSON SW

2010-10-08T23:59:59.000Z

44

Long-Wave Dynamics of Sea Level Variations during Indian Ocean Dipole Events  

Science Conference Proceedings (OSTI)

Long-wave dynamics of the interannual variations of the equatorial Indian Ocean circulation are studied using an ocean general circulation model forced by the assimilated surface winds and heat flux of the European Centre for Medium-Range Weather ...

Dongliang Yuan; Hailong Liu

2009-05-01T23:59:59.000Z

45

Interannual and Decadal Variations of Planetary Wave Activity, Stratospheric Cooling, and Northern Hemisphere Annular Mode  

Science Conference Proceedings (OSTI)

Using NCEP–NCAR 51-yr reanalysis data, the interannual and decadal variations of planetary wave activity and its relationship to stratospheric cooling, and the Northern Hemisphere Annular mode (NAM), are studied. It is found that winter ...

Yongyun Hu; Ka Kit Tung

2002-07-01T23:59:59.000Z

46

Hurricane Directional Wave Spectrum Spatial Variation at Landfall  

Science Conference Proceedings (OSTI)

The NASA Scanning Radar Altimeter (SRA) flew aboard one of the NOAA WP-3D hurricane research aircraft to document the sea surface directional wave spectrum in the region between Charleston, South Carolina, and Cape Hatteras, North Carolina, as ...

E. J. Walsh; C. W. Wright; D. Vandemark; W. B. Krabill; A. W. Garcia; S. H. Houston; S. T. Murillo; M. D. Powell; P. G. Black; F. D. Marks Jr.

2002-06-01T23:59:59.000Z

47

Correlations of whitecap coverage and gas transfer velocity with microwave brightness temperature for plunging and spilling breaking waves  

DOE Green Energy (OSTI)

Bubbles and bubble plumes generated by wind-induced breaking waves significantly enhance the gas exchange across the interface between the ocean and atmosphere under high-wind conditions. Whitcaps, or active spilling wave crests, are the sea-surface manifestation of the bubbles and bubble plumes in the subsurface mixed layer, and the fractional area of the sea surface covered by which has been proposed to correlate linearly with the air-sea gas transfer velocity. The presence of whitecaps substantially increases the microwave brightness temperature of the sea surface. It could be possible to estimate the whitecap coverage from the sea-surface microwave brightness temperature would also be very helpful in developing a remote-sensing model for predicting air-sea gas transfer velocities from microwave brightness temperatures. As a part of an air-water gas exchange experiment conducted in an outdoor surf pool, measurements were made that were designed to investigate the correlation between whitecap coverage and microwave brightness temperature. A mechanical wave maker was located at the deep end of the pool and the generated waves propagate and break towards the shallow end of the pool. Two wave patterns characteristic of plunging and spilling breaking waves at four wave heights from 0.3 m to 1.2 m were produced.

Wang, Qin; Monahan, E.C. [Connecticut Univ., Groton, CT (United States). Marine Sciences Inst.; Asher, W.E. [Battelle/Marine Sciences Lab., Sequim, WA (United States); Smith, P.M. [Naval Research Lab. Detachment, Stennis Space Center, MS (United States)

1995-07-01T23:59:59.000Z

48

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

49

Estimating Wind Velocities in Mountain Lee Waves Using Sailplane Flight Data  

Science Conference Proceedings (OSTI)

Mountain lee waves are a form of atmospheric gravity wave that is generated by flow over mountain topography. Mountain lee waves are of considerable interest, because they can produce drag that affects the general circulation, windstorms, and ...

R. P. Millane; G. D. Stirling; R. G. Brown; N. Zhang; V. L. Lo; E. Enevoldson; J. E. Murray

2010-01-01T23:59:59.000Z

50

Variational Wave Data Assimilation in a Third-Generation Wave Model  

Science Conference Proceedings (OSTI)

The adjoint of the wave model WAM, which runs operationally performing global wave forecast at the European Centre for Medium-Range Weather Forecasts, has been constructed. In this model, the nonlinear interactions are described by the discrete ...

Miriam M. De Las Heras; Gerrit Burgers; Peter A. E. M. Janssen

1994-10-01T23:59:59.000Z

51

Hurricane Directional Wave Spectrum Spatial Variation in the Open Ocean  

Science Conference Proceedings (OSTI)

The sea surface directional wave spectrum was measured for the first time in all quadrants of a hurricane's inner core over open water. The NASA airborne scanning radar altimeter (SRA) carried aboard one of the NOAA WP-3D hurricane research ...

C. W. Wright; E. J. Walsh; D. Vandemark; W. B. Krabill; A. W. Garcia; S. H. Houston; M. D. Powell; P. G. Black; F. D. Marks

2001-08-01T23:59:59.000Z

52

Shear Wave Velocity Structure of Southern African Crust: Evidence for Compositional Heterogeneity within Archaean and Proterozoic Terrains  

Science Conference Proceedings (OSTI)

Crustal structure in southern Africa has been investigated by jointly inverting receiver functions and Rayleigh wave group velocities for 89 broadband seismic stations spanning much of the Precambrian shield of southern Africa. 1-D shear wave velocity profiles obtained from the inversion yield Moho depths that are similar to those reported in previous studies and show considerable variability in the shear wave velocity structure of the lower part of the crust between some terrains. For many of the Archaean and Proterozoic terrains in the shield, S velocities reach 4.0 km/s or higher over a substantial part of the lower crust. However, for most of the Kimberley terrain and adjacent parts of the Kheis Province and Witwatersrand terrain, as well as for the western part of the Tokwe terrain, mean shear wave velocities of {le} 3.9 km/s characterize the lower part of the crust along with slightly ({approx}5 km) thinner crust. These findings indicate that the lower crust across much of the shield has a predominantly mafic composition, except for the southwest portion of the Kaapvaal Craton and western portion of the Zimbabwe Craton, where the lower crust is intermediate-to-felsic in composition. The parts of the Kaapvaal Craton underlain by intermediate-to-felsic lower crust coincide with regions where Ventersdorp rocks have been preserved, and thus we suggest that the intermediate-to-felsic composition of the lower crust and the shallower Moho may have resulted from crustal melting during the Ventersdorp tectonomagmatic event at c. 2.7 Ga and concomitant crustal thinning caused by rifting.

Kgaswane, E M; Nyblade, A A; Julia, J; Dirks, P H H M; Durrheim, R J; Pasyanos, M E

2008-11-11T23:59:59.000Z

53

Fetch Relations for Wind-Generated Waves as a Function of Wind-Stress Scaling  

Science Conference Proceedings (OSTI)

We present the variation that results when fetch relations for wind-generated wave spectra are sealed by the friction velocity component in the dominant wave direction rather than the magnitude of the friction velocity, using the data collected ...

Will Perrie; Bechara Toulany

1990-11-01T23:59:59.000Z

54

Rossby Wave Frequencies and Group Velocities for Finite Element and Finite Difference Approximations to the Vorticity-Divergence and the Primitive Forms of the Shallow Water Equations  

Science Conference Proceedings (OSTI)

In this paper Rossby wave frequencies and group velocities are analyzed for various finite element and finite difference approximations to the vorticity-divergence form of the shallow water equations. Also included are finite difference solutions ...

Beny Neta; R. T. Williams

1989-07-01T23:59:59.000Z

55

A Systematic Search for Trapped Equatorial Waves in the GATE Velocity Data  

Science Conference Proceedings (OSTI)

Moored current meter data taken over a 60-day period during GATE (GARP Atlantic Tropical Experiment) near the equator at 28°W, have been systematically searched for vertically propagating equatorially trapped waves. Three independent tests ...

A. M. Horigan; R. H. Weisberg

1981-04-01T23:59:59.000Z

56

One dimensional P wave velocity structure of the crust beneath west Java and accurate hypocentre locations from local earthquake inversion  

SciTech Connect

A one-dimensional (1-D) velocity model and station corrections for the West Java zone were computed by inverting P-wave arrival times recorded on a local seismic network of 14 stations. A total of 61 local events with a minimum of 6 P-phases, rms 0.56 s and a maximum gap of 299 Degree-Sign were selected. Comparison with previous earthquake locations shows an improvement for the relocated earthquakes. Tests were carried out to verify the robustness of inversion results in order to corroborate the conclusions drawn out from our reasearch. The obtained minimum 1-D velocity model can be used to improve routine earthquake locations and represents a further step toward more detailed seismotectonic studies in this area of West Java.

Supardiyono; Santosa, Bagus Jaya [Physics Department, Faculty of Mathematics and Natural Sciences, State University of Surabaya, Surabaya (Indonesia) and Physics Department, Faculty of Mathematics and Natural Sciences, Sepuluh Nopember Institute of Technology, Surabaya (Indonesia); Physics Department, Faculty of Mathematics and Natural Sciences, Sepuluh Nopember Institute of Technology, Surabaya (Indonesia)

2012-06-20T23:59:59.000Z

57

Estimating fracture parameters from p-wave velocity profiles about a geothermal well  

DOE Green Energy (OSTI)

The feasibility of locating fracture zones and estimating their crack parameters was examined using an areal well shoot method centered on Utah State Geothermal Well 9-1, Beaver County, Utah. High-resolution travel time measurements were made between a borehole sensor and an array of shot stations distributed radially and azimuthally about the well. Directional velocity behavior in the vicinity of the well was investigated by comparing velocity logs derived from the travel time data. Three fracture zones were identified form the velocity data, corroborating fracture indicators seen in other geophysical logs conducted in Well 9-1. Crack densities and average crack aspect ratios for these fracture zones were estimated using a self-consistent velocity theory (O'Connell and Budiansy 1974). Probable trends of these fracture zones were established from a combination of the data from the more distant shot stations and the results of a gravity survey. The results of this study indicate that the areal well shoot is a potentially powerful tool for the reconnaisance of fracture-controlled fluid and gas reservoirs. Improvements in methodology and hardware could transform it into an operationally viable survey method.

Jenkinson, J.T.; Henyey, T.L.; Sammis, C.G.; Leary, P.C.; McRaney, J.K.

1981-12-01T23:59:59.000Z

58

Electrostatic drift-wave instability in a nonuniform quantum magnetoplasma with parallel velocity shear flows  

SciTech Connect

The propagation of high and low frequency (in comparison with the cyclotron frequency) electrostatic drift-waves is investigated in a nonuniform, dense magnetoplasma (composed of electrons and ions), in the presence of parallel shear flow, by employing the quantum magnetohydrodynamic (QMHD) model. Using QMHD model, a new set of equations is presented in order to investigate linear properties of electrostatic drift-waves with sheared plasma flows for dense plasmas. In this regard, dispersion relations for coupled electron-thermal and drift-ion acoustic modes are derived and several interesting limiting cases are discussed. For instance, it is found that sheared ion flow parallel to the external magnetic field can drive the quantum drift-ion acoustic wave unstable, etc. The present investigation may have relevance in dense astrophysical environments where quantum effects are significant.

Tariq, Sabeen; Mirza, Arshad M. [Department of Physics, Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Masood, W. [Theoretical Plasma Physics Division, PINSTECH, P.O. Box. Nilore, Islamabad 44000, Pakistan and National Center for Physics (NCP), Islamabad 45320 (Pakistan)

2010-10-15T23:59:59.000Z

59

Imaging earth's interior: Tomographic inversions for mantle P-wave velocity structure  

SciTech Connect

A formalism is developed for the tomographic inversion of seismic travel time residuals. The travel time equations are solved both simultaneously, for velocity model terms and corrections to the source locations, and progressively, for each set of terms in succession. The methods differ primarily in their treatment of source mislocation terms. Additionally, the system of equations is solved directly, neglecting source terms. The efficacy of the algorithms is explored with synthetic data as we perform simulations of the general procedure used to produce tomographic images of Earth's mantle from global earthquake data. The patterns of seismic heterogeneity in the mantle that would be returned reliably by a tomographic inversion are investigated. We construct synthetic data sets based on real ray sampling of the mantle by introducing spherical harmonic patterns of velocity heterogeneity and perform inversions of the synthetic data.

Pulliam, R.J.

1991-07-01T23:59:59.000Z

60

Interannual Variations in Mixed Rossby–Gravity Waves and Their Impacts on Tropical Cyclogenesis over the Western North Pacific  

Science Conference Proceedings (OSTI)

The present study investigates the transition from mixed Rossby–gravity (MRG) waves to tropical depression (TD)-type disturbances and its interannual variations over the western North Pacific (WNP), using ECMWF high-resolution data for the years ...

Guanghua Chen; Ronghui Huang

2009-02-01T23:59:59.000Z

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61

Spin-Orbit Alignment of the TrES-4 Transiting Planetary System and Possible Additional Radial-Velocity Variation  

E-Print Network (OSTI)

We report new radial velocities of the TrES-4 transiting planetary system, including observations of

Narita, Norio

62

Minimum variational principles for time-harmonic waves in a dissipative medium and associated variational principles of Hashin--Shtrikman type  

E-Print Network (OSTI)

Minimization variational principles for linear elastodynamic, acoustic, or electromagnetic time-harmonic waves in dissipative media were obtained by Milton, Seppecher and Bouchitt\\'e generalizing the quasistatic variational principles of Cherkaev and Gibiansky. Here a further generalization is made to allow for a much wider variety of boundary conditions, and in particular Dirichlet and Neumann boundary conditions. In addition minimization or maximization principles of the Hashin-Shtrikman type, incorporating "polarization fields", are developed.

Graeme W. Milton; John R. Willis

2010-01-15T23:59:59.000Z

63

The Response of an Open Stratospheric Balloon to the Presence of Inertio-Gravity Waves  

Science Conference Proceedings (OSTI)

Analytic solutions for the vertical response of an open stratospheric balloon to the presence of inertio-gravity waves during its descent are obtained. Monochromatic waves with simultaneous variations in density, velocity, and temperature are ...

P. Alexander; J. Cornejo; A. De la Torre

1996-01-01T23:59:59.000Z

64

Variational Analysis of Oversampled Dual-Doppler Radial Velocity Data and Application to the Analysis of Tornado Circulations  

Science Conference Proceedings (OSTI)

For the detection of severe weather phenomena such as tornados, mesocyclones, and strong wind shear, the azimuthal resolution of radial velocity measurements is more important. The typical azimuthal resolutions of 1° for the Weather Surveillance ...

Ming Xue; Shun Liu; Tian-You Yu

2007-03-01T23:59:59.000Z

65

Latitudinal Variations of the Convective Source and Propagation Condition of Inertio-Gravity Waves in the Tropics  

Science Conference Proceedings (OSTI)

Latitudinal variations of the convective source and vertical propagation condition of inertio-gravity waves (IGWs) in the tropical region (30°S–30°N) are examined using high-resolution Global Cloud Imagery (GCI) and 6-hourly NCEP–NCAR reanalysis ...

Hye-Yeong Chun; Jung-Suk Goh; In-Sun Song; Lucrezia Ricciardulli

2007-05-01T23:59:59.000Z

66

Interdecadal Variations of the East Asian Winter Monsoon and Their Association with Quasi-Stationary Planetary Wave Activity  

Science Conference Proceedings (OSTI)

Interdecadal variations of the East Asian winter monsoon (EAWM) and their association with the quasi-stationary planetary wave activity are analyzed by using the 40-yr European Centre for Medium-Range Weather Forecasts Re-Analysis dataset and the ...

Lin Wang; Ronghui Huang; Lei Gu; Wen Chen; Lihua Kang

2009-09-01T23:59:59.000Z

67

The Effect of the Interference of Traveling and Stationary Waves on Time Variations of the Large-Scale Circulation  

Science Conference Proceedings (OSTI)

It is hypothesized that the interference of stationary and traveling waves of the same longitudinal can cause some of the observed time variations in the large-scale circulation. To explore this hypothesis the eight-winter average structure of a ...

Roland A. Madden

1983-05-01T23:59:59.000Z

68

Seasonal Variations in the Formation of Internal Gravity Waves at a Coastal Site  

Science Conference Proceedings (OSTI)

Atmospheric internal gravity waves that formed over a coastal and an inland site were identified from analog records of wind speed and direction. Internal gravity waves occurred at all hours at the coastal site but only during nights inland. More ...

S. SethuRaman; C. Nagle; G. S. Raynor

1982-02-01T23:59:59.000Z

69

Variations  

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

Variations Variations in Cellulosic Ultrastructure of Poplar Marcus Foston & Christopher A. Hubbell & Mark Davis & Arthur J. Ragauskas Published online: 13 October 2009 # Springer Science + Business Media, LLC. 2009 Abstract A key property involved in plant recalcitrance is cellulose crystallinity. In an attempt to establish the typical diversity in cellulose ultrastructure for poplar, the variation and distribution of supramolecular and ultrastructural features, including the fraction of crystalline cellulose forms I a and I b , para-crystalline cellulose and amorphous cellulose content were characterized. In this study, the percent crystallinity (%Cr) and lateral fibril dimensions of cellulose isolated from poplar were determined for 18 poplar core samples collected in the northwestern region of the USA. Keywords Cellulose . Poplar . Solid-state NMR Introduction

70

Lee Wave Vertical Structure Monitoring Using Height–Time Analysis of VHF?ST Radar Vertical Velocity Data  

Science Conference Proceedings (OSTI)

The strong lee wave event of intensive observation period 3 (14–15 October 1990) of the Pyrenean experiment was studied using a single VHF stratospheric–tropospheric radar installed 35 km downstream from the Pyrenean chain axis. This instrument ...

Jean-Luc Caccia

1998-05-01T23:59:59.000Z

71

Influence of Linear Depth Variation on Poincaré, Kelvin, and Rossby Waves  

Science Conference Proceedings (OSTI)

Exact solutions to the linearized shallow-water equations in a channel with linear depth variation and a mean flow are obtained in terms of confluent hypergeometric functions. These solutions are the generalization to finite s (depth variation ...

A. N. Staniforth; R. T. Williams; B. Neta

1993-04-01T23:59:59.000Z

72

The Effect of Alongshore Topographic Variation and Bottom Friction on Shelf Wave Interactions  

Science Conference Proceedings (OSTI)

The theory of resonant interactions between continental shelf waves developed by Hsieh and Mysak to explain aspects of the shelf wave spectra observed on the Oregon shelf by Cutchin and Smith and Huyer et al. is extended to include the effect of ...

François W. Primeau; Gordon E. Swaters

1994-05-01T23:59:59.000Z

73

In-plane ultrasonic velocity measurement of longitudinal and shear waves in the machine direction with transducers in rotating wheels  

DOE Patents (OSTI)

An improved system for measuring the velocity of ultrasonic signals within the plane of moving web-like materials, such as paper, paperboard and the like. In addition to velocity measurements of ultrasonic signals in the plane of the web in the MD and CD, one embodiment of the system in accordance with the present invention is also adapted to provide on-line indication of the polar specific stiffness of the moving web. In another embodiment of the invention, the velocity of ultrasonic signals in the plane of the web are measured by way of a plurality of ultrasonic transducers carried by synchronously driven wheels or cylinders, thus eliminating undue transducer wear due to any speed differences between the transducers and the web. In order to provide relatively constant contact force between the transducers and the webs, the transducers are mounted in a sensor housings which include a spring for biasing the transducer radially outwardly. The sensor housings are adapted to be easily and conveniently mounted to the carrier to provide a relatively constant contact force between the transducers and the moving web.

Hall, Maclin S. (Marietta, GA); Jackson, Theodore G. (Atlanta, GA); Knerr, Christopher (Lawrenceville, GA)

1998-02-17T23:59:59.000Z

74

In-plane ultrasonic velocity measurement of longitudinal and shear waves in the machine direction with transducers in rotating wheels  

DOE Patents (OSTI)

An improved system for measuring the velocity of ultrasonic signals within the plane of moving web-like materials, such as paper, paperboard and the like. In addition to velocity measurements of ultrasonic signals in the plane of the web in the MD and CD, one embodiment of the system in accordance with the present invention is also adapted to provide on-line indication of the polar specific stiffness of the moving web. In another embodiment of the invention, the velocity of ultrasonic signals in the plane of the web are measured by way of a plurality of ultrasonic transducers carried by synchronously driven wheels or cylinders, thus eliminating undue transducer wear due to any speed differences between the transducers and the web. In order to provide relatively constant contact force between the transducers and the webs, the transducers are mounted in a sensor housings which include a spring for biasing the transducer radially outwardly. The sensor housings are adapted to be easily and conveniently mounted to the carrier to provide a relatively constant contact force between the transducers and the moving web. 37 figs.

Hall, M.S.; Jackson, T.G.; Knerr, C.

1998-02-17T23:59:59.000Z

75

Dust ion-acoustic shock waves in charge varying dusty plasmas with electrons having vortexlike velocity distribution  

Science Conference Proceedings (OSTI)

A weakly nonlinear analysis is carried out to investigate the properties of dust ion-acoustic shock waves in a charge varying dusty plasma with vortexlike electron distribution. We use the ionization model, hot ions with equilibrium streaming speed and a trapped electron charging current derived from the well-known orbit limited motion theory. A new modified Burger equation is derived. Besides nonlinear trapping, this equation involves two kinds of dissipation (the anomalous one inherent to nonadiabatic dust charge fluctuation and the one due to the particle loss and ionization). These two kinds of dissipation can act concurrently. The traveling wave solution has been acquired by employing the modified extended tanh-function method. The shocklike solution is numerically analyzed based on the typical numerical data from laboratory dusty plasma devices. It is found that ion temperature, trapped particles, and weak dissipations significantly modify the shock structures.

Alinejad, H. [Department of Physics, Faculty of Basic Science, Babol University of Technology, Babol 47148-71167 (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha, P.O. Box 55134-441, Maragha 55177-36698 (Iran, Islamic Republic of); Tribeche, M. [Plasma Physics Group (PPG), Theoretical Physics Laboratory (TPL), Faculty of Science-Physics, University of Bab-Ezzouar, USTHB, B.P. 32, El Alia, Algiers (Algeria)

2010-12-15T23:59:59.000Z

76

The Variational Bayesian Approach to Fitting Mixture Models to Circular Wave Direction Data  

Science Conference Proceedings (OSTI)

The emerging variational Bayesian (VB) technique for approximate Bayesian statistical inference is a non-simulation-based and time-efficient approach. It provides a useful, practical alternative to other Bayesian statistical approaches such as ...

Burton Wu; Clare A. McGrory; Anthony N. Pettitt

2012-10-01T23:59:59.000Z

77

SURFACE ALFVEN WAVES IN SOLAR FLUX TUBES  

SciTech Connect

Magnetohydrodynamic (MHD) waves are ubiquitous in the solar atmosphere. Alfven waves and magneto-sonic waves are particular classes of MHD waves. These wave modes are clearly different and have pure properties in uniform plasmas of infinite extent only. Due to plasma non-uniformity, MHD waves have mixed properties and cannot be classified as pure Alfven or magneto-sonic waves. However, vorticity is a quantity unequivocally related to Alfven waves as compression is for magneto-sonic waves. Here, we investigate MHD waves superimposed on a one-dimensional non-uniform straight cylinder with constant magnetic field. For a piecewise constant density profile, we find that the fundamental radial modes of the non-axisymmetric waves have the same properties as surface Alfven waves at a true discontinuity in density. Contrary to the classic Alfven waves in a uniform plasma of infinite extent, vorticity is zero everywhere except at the cylinder boundary. If the discontinuity in density is replaced with a continuous variation of density, vorticity is spread out over the whole interval with non-uniform density. The fundamental radial modes of the non-axisymmetric waves do not need compression to exist unlike the radial overtones. In thin magnetic cylinders, the fundamental radial modes of the non-axisymmetric waves with phase velocities between the internal and the external Alfven velocities can be considered as surface Alfven waves. On the contrary, the radial overtones can be related to fast-like magneto-sonic modes.

Goossens, M.; Andries, J.; Soler, R.; Van Doorsselaere, T. [Centre for Plasma Astrophysics, Department of Mathematics, Katholieke Universiteit Leuven, Celestijnenlaan 200B, 3001 Leuven (Belgium); Arregui, I.; Terradas, J., E-mail: marcel.goossens@wis.kuleuven.be [Solar Physics Group, Departament de Fisica, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain)

2012-07-10T23:59:59.000Z

78

Breaking the waves: improved detection of copy number variation from microarray-based comparative genomic hybridization  

E-Print Network (OSTI)

‡, Tomas Fitzgerald‡, Richard Redon‡, Heike Fiegler‡, T Daniel Andrews‡, Barbara E Stranger‡, Andrew G Lynch†, Emmanouil T Dermitzakis‡, Nigel P Carter‡, Simon Tavaré*† and Matthew E Hurles‡ Addresses: *Computational Biology Group, Department of Applied... identifying CNVs enables more biological information to be extracted from aCGH experiments designed to investigate copy number variation in normal individuals. Published: 25 October 2007 Genome Biology 2007, 8:R228 (doi:10.1186/gb-2007-8-10-r228) Received: 3...

Marioni, John C; Thorne, Natalie P; Valsesia, Armand; Fitzgerald, Tomas; Redon, Richard; Fiegler, Heike; Andrews, T Daniel; Stranger, Barbara E; Lynch, Andrew G; Dermitzakis, Emmanouil T; Carter, Nigel P; Tavare, Simon; Hurles, Matthew E

2007-10-25T23:59:59.000Z

79

Fiber-optic voltage sensor with cladded fiber and evanescent wave variation detection  

DOE Patents (OSTI)

A fiber optic voltage sensor is described which includes a source of light, a reference fiber for receiving a known percentage of the light and an electrostrictive element having terminals across which is applied, a voltage to be measured. The electrostrictive element is responsive to the applied voltage to assume an altered physical state. A measuring fiber also receives a known percentage of light from the light source and is secured about the electrostrictive element. The measuring fiber is provided with a cladding and exhibits an evanescent wave in the cladding. The measuring fiber has a known length which is altered when the electrostrictive element assumes its altered physical state. A differential sensor is provided which senses the intensity of light in both the reference fiber and the measuring fiber and provides an output indicative of the difference between the intensities.

Wood, Charles B. (Lakewood, CO)

1992-01-01T23:59:59.000Z

80

Fiber-optic voltage sensor with cladded fiber and evanescent wave variation detection  

DOE Patents (OSTI)

A fiber optic voltage sensor is described which includes a source of light, a reference fiber for receiving a known percentage of the light and an electrostrictive element having terminals across which is applied, a voltage to be measured. The electrostrictive element is responsive to the applied voltage to assume an altered physical state. A measuring fiber also receives a known percentage of light from the light source and is secured about the electrostrictive element. The measuring fiber is provided with a cladding and exhibits an evanescent wave in the cladding. The measuring fiber has a known length which is altered when the electrostrictive element assumes its altered physical state. A differential sensor is provided which senses the intensity of light in both the reference fiber and the measuring fiber and provides an output indicative of the difference between the intensities. 3 figs.

Wood, C.B.

1992-12-15T23:59:59.000Z

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


81

Variations in the Flow of the Global Atmosphere Associated with a Composite Convectively Coupled Oceanic Kelvin Wave  

Science Conference Proceedings (OSTI)

Kelvin waves in the Pacific Ocean occasionally develop and propagate eastward together with anomalies of deep convection and low-level westerly wind. This pattern suggests coupling between the oceanic waves and atmospheric convection. A simple ...

Paul E. Roundy; Lynn M. Gribble-Verhagen

2010-08-01T23:59:59.000Z

82

Body Wave Tomography For Regional Scale Assessment Of Geothermal Indicators  

Open Energy Info (EERE)

Body Wave Tomography For Regional Scale Assessment Of Geothermal Indicators Body Wave Tomography For Regional Scale Assessment Of Geothermal Indicators In The Western Great Basin Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Body Wave Tomography For Regional Scale Assessment Of Geothermal Indicators In The Western Great Basin Details Activities (8) Areas (4) Regions (0) Abstract: Body and surface wave tomography are two of the primary methods for estimation of regional scale seismic velocity variations. Seismic velocity is affected by temperature and rock composition in complex ways, but when combined with geologic and structural maps, relative temperature can in some cases be estimated. We present preliminary tomographic models for compressional and shear-wave velocity using local and regional earthquakes recorded by Earthscope Transportable Array stations, network

83

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

84

Effects of Stratification and Bottom Topography on the Kuroshio Path Variation South of Japan. Part I: Dependence of the Path Selection on Velocity  

Science Conference Proceedings (OSTI)

Numerical experiments are executed using a two-layer inflow–outflow ocean model with simplified geometry to investigate the effects of stratification and bottom topography on the path variation of the Kuroshio south of Japan. In a flat-bottom ...

Shuhei Masuda; Kazunori Akitomo; Toshiyuki Awaji

1999-09-01T23:59:59.000Z

85

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

86

The Seasonal Variation of the Propagating Diurnal Tide in the Mesosphere and Lower Thermosphere. Part I: The Role of Gravity Waves and Planetary Waves  

Science Conference Proceedings (OSTI)

The seasonal variation of the propagating diurnal tide in the mesosphere and lower thermosphere is examined using results from a 2-yr simulation of the extended version of the Canadian Middle Atmosphere Model (CMAM). The CMAM is shown to be able ...

Charles McLandress

2002-03-01T23:59:59.000Z

87

Three-dimensional V p /V s variations for the Coso region, California |  

Open Energy Info (EERE)

p /V s variations for the Coso region, California p /V s variations for the Coso region, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Three-dimensional V p /V s variations for the Coso region, California Details Activities (1) Areas (1) Regions (0) Abstract: Recent seismological studies of the Coso region of southeastern California document both low P wave velocities and abnormal SV attenuation in Indian Wells Valley, south of the Pleistocene volcanics of the Coso Range. In order to learn more about the physical nature of these colocated anomalies, a tomographic inversion for the three-dimensional variations of Vp /Vs the ratio of compressional to shear velocity was performed. Iterative back projection of 2966 shear and compressional wave travel time residuals from local earthquakes recorded on vertical instruments reveals

88

Wave Breaking Dissipation Observed with “SWIFT” Drifters  

Science Conference Proceedings (OSTI)

Energy dissipation rates during ocean wave breaking are estimated from high-resolution profiles of turbulent velocities collected within 1 m of the surface. The velocity profiles are obtained from a pulse-coherent acoustic Doppler sonar on a wave-...

Jim Thomson

2012-12-01T23:59:59.000Z

89

Topographic Waves Generated by a Transient Wind  

Science Conference Proceedings (OSTI)

The concept of linear mountain waves is generally equated with steady-state stationary waves. This essentially means that the absolute horizontal phase velocity of mountain waves is zero and that their momentum flux profile is independent of ...

François Lott; Hector Teitelbaum

1993-08-01T23:59:59.000Z

90

Spectral Wave–Turbulence Decomposition  

Science Conference Proceedings (OSTI)

A new method of wave–turbulence decomposition is introduced, for which the only instrument required is one high-frequency pointwise velocity sensor. This is a spectral method that assumes equilibrium turbulence and no wave–turbulence interaction. ...

Jeremy D. Bricker; Stephen G. Monismith

2007-08-01T23:59:59.000Z

91

Ion-acoustic cnoidal wave and associated non-linear ion flux in dusty plasma  

Science Conference Proceedings (OSTI)

Using reductive perturbation method with appropriate boundary conditions, coupled evolution equations for first and second order potentials are derived for ion-acoustic waves in a collisionless, un-magnetized plasma consisting of hot isothermal electrons, cold ions, and massive mobile charged dust grains. The boundary conditions give rise to renormalization term, which enable us to eliminate secular contribution in higher order terms. Determining the non secular solution of these coupled equations, expressions for wave phase velocity and averaged non-linear ion flux associated with ion-acoustic cnoidal wave are obtained. Variation of the wave phase velocity and averaged non-linear ion flux as a function of modulus (k{sup 2}) dependent wave amplitude are numerically examined for different values of dust concentration, charge on dust grains, and mass ratio of dust grains with plasma ions. It is found that for a given amplitude, the presence of positively (negatively) charged dust grains in plasma decreases (increases) the wave phase velocity. This behavior is more pronounced with increase in dust concentrations or increase in charge on dust grains or decrease in mass ratio of dust grains. The averaged non-linear ion flux associated with wave is positive (negative) for negatively (positively) charged dust grains in the plasma and increases (decreases) with modulus (k{sup 2}) dependent wave amplitude. For given amplitude, it increases (decreases) as dust concentration or charge of negatively (positively) charged dust grains increases in the plasma.

Jain, S. L. [Poornima Group of Institution, Sitapura, Jaipur 302022 (India); Tiwari, R. S. [Regional College for Education, Research and Technology, Jaipur 302022 (India); Mishra, M. K. [Department of Physics, University of Rajasthan, Jaipur 302004 (India)

2012-10-15T23:59:59.000Z

92

Wave Mechanics and the Fifth Dimension  

E-Print Network (OSTI)

Replacing 4D Minkowski space by 5D canonical space leads to a clearer derivation of the main features of wave mechanics, including the wave function and the velocity of de Broglie waves. Recent tests of wave-particle duality could be adapted to investigate whether de Broglie waves are basically 4D or 5D in nature.

Paul S. Wesson; James M. Overduin

2013-01-28T23:59:59.000Z

93

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

94

Composite Vertical Structure of Vertical Velocity in Nonprecipitating Cumulus Clouds  

Science Conference Proceedings (OSTI)

Vertical transects of Doppler vertical velocity data, obtained from an airborne profiling millimeter-wave cloud radar, are composited for a large number of cumulus clouds (Cu) at various stages of their life cycle, to examine typical circulations ...

Yonggang Wang; Bart Geerts

2013-05-01T23:59:59.000Z

95

P wave anisotropy, stress, and crack distribution at Coso geothermal field,  

Open Energy Info (EERE)

wave anisotropy, stress, and crack distribution at Coso geothermal field, wave anisotropy, stress, and crack distribution at Coso geothermal field, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: P wave anisotropy, stress, and crack distribution at Coso geothermal field, California Details Activities (1) Areas (1) Regions (0) Abstract: A new inversion method for P wave anisotropy (Wu and Lees, 1999a) has been applied to high-precision, microseismic traveltime data collected at Coso geothermal region, California. Direction-dependent P wave velocity and thus its perturbation, are represented by a symmetric positive definite matrix A instead of a scalar. The resulting anisotropy distribution is used to estimate variations in crack density, stress distribution and permeability within the producing geothermal field. A circular dome-like

96

Interactions between Rain and Wind Waves  

Science Conference Proceedings (OSTI)

Effects of rain on surface waves have been investigated in a circulating wind-wave tank. Surface displacement and slope spectra under different wind velocities were measured near the upwind and downwind edges of a region with simulated rains. ...

Ying-Keung Poon; Shih Tang; Jin Wu

1992-09-01T23:59:59.000Z

97

Inertia–Gravity Waves in the Stratosphere  

Science Conference Proceedings (OSTI)

The propagation and refraction of stationary inertia–gravity waves in the winter stratosphere is examined with ray tracing. Due to their smaller vertical group velocity these waves experience more lateral ray movement and horizontal refraction ...

Timothy J. Dunkerton

1984-12-01T23:59:59.000Z

98

Fiber Optic Velocity Interferometry  

SciTech Connect

This paper explores the use of a new velocity measurement technique that has several advantages over existing techniques. It uses an optical fiber to carry coherent light to and from a moving target. A Fabry-Perot interferometer, formed by a gradient index lens and the moving target, produces fringes with a frequency proportional to the target velocity. This technique can measure velocities up to 10 km/s, is accurate, portable, and completely noninvasive.

Neyer, Barry T.

1988-04-01T23:59:59.000Z

99

The Coupling of Vertical Velocity and Signal Power Observed with the SOUSY VHF Radar  

Science Conference Proceedings (OSTI)

The perturbations to the static stability (and hence to the radar reflectivity) and to the velocity in a vertically propagating gravity wave are correlated, and the sign of the correlation depends on whether the wave is propagating upward or ...

G. D. Nastrom; R. Rüster; G. Schmidt

1998-01-01T23:59:59.000Z

100

Noise Effects on Wave-Generated Transport Induced by Ideal Waves  

Science Conference Proceedings (OSTI)

The authors consider the transport velocity in boundary layer flows driven by either noisy monochromatic progressive or standing waves. The central issue addressed here is whether such flows are capable of sustaining a transport velocity when ...

Juan M. Restrepo; Gary K. Leaf

2002-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "wave velocity variations" 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

Sheets Wave Basin | Open Energy Information  

Open Energy Info (EERE)

Sheets Wave Basin Sheets Wave Basin Jump to: navigation, search Basic Specifications Facility Name Sheets Wave Basin Overseeing Organization University of Rhode Island Hydrodynamic Testing Facility Type Wave Basin Length(m) 30.0 Beam(m) 3.6 Depth(m) 1.8 Cost(per day) $750(+ Labor/Materials) Towing Capabilities Towing Capabilities Yes Maximum Velocity(m/s) 2.0 Length of Effective Tow(m) 25.0 Wavemaking Capabilities Wavemaking Capabilities Yes Maximum Wave Height(m) 0.3 Maximum Wave Height(m) at Wave Period(s) 3.0 Maximum Wave Length(m) 10 Wave Period Range(s) 3.0 Current Velocity Range(m/s) 0.0 Programmable Wavemaking Yes Wavemaking Description Pre-programmed for regular and irregular waves, but wavemaker is capable of any input motion. Wave Direction Uni-Directional

102

Traveling-wave photodetector  

DOE Patents (OSTI)

The traveling-wave photodetector of the present invention combines an absorptive optical waveguide and an electrical transmission line, in which optical absorption in the waveguide results in a photocurrent at the electrodes of the electrical transmission line. The optical waveguide and electrical transmission line of the electrically distributed traveling-wave photodetector are designed to achieve matched velocities between the light in the optical waveguide and electrical signal generated on the transmission line. This velocity synchronization provides the traveling-wave photodetector with a large electrical bandwidth and a high quantum efficiency, because of the effective extended volume for optical absorption. The traveling-wave photodetector also provides large power dissipation, because of its large physical size. 4 figures.

Hietala, V.M.; Vawter, G.A.

1993-12-14T23:59:59.000Z

103

Traveling-wave photodetector  

DOE Patents (OSTI)

The traveling-wave photodetector of the present invention combines an absorptive optical waveguide and an electrical transmission line, in which optical absorption in the waveguide results in a photocurrent at the electrodes of the electrical transmission line. The optical waveguide and electrical transmission line of the electrically distributed traveling-wave photodetector are designed to achieve matched velocities between the light in the optical waveguide and electrical signal generated on the transmission line. This velocity synchronization provides the traveling-wave photodetector with a large electrical bandwidth and a high quantum efficiency, because of the effective extended volume for optical absorption. The traveling-wave photodetector also provides large power dissipation, because of its large physical size.

Hietala, V.M.; Vawter, G.A.

1992-12-31T23:59:59.000Z

104

Traveling-wave photodetector  

DOE Patents (OSTI)

The traveling-wave photodetector of the present invention combines an absorptive optical waveguide and an electrical transmission line, in which optical absorption in the waveguide results in a photocurrent at the electrodes of the electrical transmission line. The optical waveguide and electrical transmission line of the electrically distributed traveling-wave photodetector are designed to achieve matched velocities between the light in the optical waveguide and electrical signal generated on the transmission line. This velocity synchronization provides the traveling-wave photodetector with a large electrical bandwidth and a high quantum efficiency, because of the effective extended volume for optical absorption. The traveling-wave photodetector also provides large power dissipation, because of its large physical size.

Hietala, Vincent M. (Placitas, NM); Vawter, Gregory A. (Albuquerque, NM)

1993-01-01T23:59:59.000Z

105

Baroclinic Waves with Parameterized Effects of Moisture Interpreted Using Rossby Wave Components  

Science Conference Proceedings (OSTI)

A theoretical framework is developed for the evolution of baroclinic waves with latent heat release parameterized in terms of vertical velocity. Both wave–conditional instability of the second kind (CISK) and large-scale rain approaches are ...

Hylke de Vries; John Methven; Thomas H. A. Frame; Brian J. Hoskins

2010-09-01T23:59:59.000Z

106

Equatorial Atlantic Velocity and Temperature Observations: February–November 1981  

Science Conference Proceedings (OSTI)

Upper ocean velocity and temperature measurements were obtained in the central equatorial Atlantic using surface moored current meters from February to November 1981. Distinct seasonal variations were observed in the zonal momentum and ...

R. H. Weisberg

1985-05-01T23:59:59.000Z

107

GPS velocity field for the Tien Shan and surrounding regions  

E-Print Network (OSTI)

Measurements at ?400 campaign-style GPS points and another 14 continuously recording stations in central Asia define variations in their velocities both along and across the Kyrgyz and neighboring parts of Tien Shan. They ...

Zubovich, Alexander V.

108

Effects of Radar Proximity on Single-Doppler Velocity Signatures of Axisymmetric Rotation and Divergence  

Science Conference Proceedings (OSTI)

Geometrical and mathematical relationships are developed to explain the variation with radar range of idealized single-Doppler velocity patterns of axisymmetric rotation and divergence regions. The velocity patterns become distorted as they ...

Vincent T. Wood; Rodger A. Brown

1992-12-01T23:59:59.000Z

109

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

110

Cirrus Crystal Terminal Velocities  

Science Conference Proceedings (OSTI)

Cirrus crystal terminal velocities are of primary importance in determining the rate of transport of condensate from upper- to middle-tropospheric levels and profoundly influence the earth’s radiation balance through their effect on the rate of ...

Andrew J. Heymsfield; Jean Iaquinta

2000-04-01T23:59:59.000Z

111

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

112

High-Velocity Rocks Final Report  

DOE Green Energy (OSTI)

The objective of our research was to develop and demonstrate seismic data-acquisition and data-processing technologies that allow geothermal prospects below high-velocity rock outcrops to be evaluated. To do this, we acquired a 3-component seismic test line across an area of exposed high-velocity rocks in Brewster County, Texas, where there is high heat flow and surface conditions mimic those found at numerous geothermal prospects. Seismic contractors have not succeeded in creating good-quality seismic data in this area for companies who have acquired data for oil and gas exploitation purposes. Our test profile traversed an area where high-velocity rocks and low-velocity sediment were exposed on the surface in alternating patterns that repeated along the test line. We verified that these surface conditions cause non-ending reverberations of Love waves, Rayleigh waves, and shallow critical refractions to travel across the earth surface between the boundaries of the fast-velocity and slow-velocity material exposed on the surface. These reverberating surface waves form the high level of noise in this area that does not allow reflections from deep interfaces to be seen and utilized. Our data-acquisition method of deploying a box array of closely spaced geophones allowed us to recognize and evaluate these surface-wave noise modes regardless of the azimuth direction to the surface anomaly that backscattered the waves and caused them to return to the test-line profile. With this knowledge of the surface-wave noise, we were able to process these test-line data to create P-P and SH-SH images that were superior to those produced by a skilled seismic data-processing contractor. Compared to the P-P data acquired along the test line, the SH-SH data provided a better detection of faults and could be used to trace these faults upward to the boundaries of exposed surface rocks. We expanded our comparison of the relative value of S-wave and P-wave seismic data for geothermal applications by inserting into this report a small part of the interpretation we have done with 3C3D data across Wister geothermal field in the Imperial Valley of California. This interpretation shows that P-SV data reveal faults (and by inference, also fractures) that cannot be easily, or confidently, seen with P-P data, and that the combination of P-P and P-SV data allows VP/VS velocity ratios to be estimated across a targeted reservoir interval to show where an interval has more sandstone (the preferred reservoir facies). The conclusion reached from this investigation is that S-wave seismic technology can be invaluable to geothermal operators. Thus we developed a strong interest in understanding the direct-S modes produced by vertical-force sources, particularly vertical vibrators, because if it can be demonstrated that direct-S modes produced by vertical-force sources can be used as effectively as the direct-S modes produced by horizontal-force sources, geothermal operators can acquire direct-S data across many more prospect areas than can be done with horizontal-force sources, which presently are limited to horizontal vibrators. We include some of our preliminary work in evaluating direct-S modes produced by vertical-force sources.

Hardage, Bob A; DeAngelo, Michael V; Ermolaeva, Elena; Hardage, Bob A; Remington, Randy; Sava, Diana; Wagner, Donald; Wei, Shuijion

2013-02-28T23:59:59.000Z

113

Ultrasonic Plate Wave Evaluation Of Natural Fiber Composite Panels  

Science Conference Proceedings (OSTI)

Two key shortcomings of current ultrasonic nondestructive evaluation (NDE) techniques for plywood, medium density fiberboard (MDF), and oriented strandboard are the reliance on empirical correlations and the neglect of valuable waveform information. The research reported herein examined the feasibility of using fundamental mechanics, wave propagation, and laminated, shear deformable plate theories to nondestructively evaluate material properties in natural fiber-based composite panels. Dispersion curves were constructed exhibiting the variation of flexural plate wave phase velocity with frequency. Based on shear deformable laminated plate wave theory, flexural and transverse shear rigidity values for solid transversely isotropic, laminated transversely isotropic, and solid orthotropic natural fiber-based composite panels were obtained from the dispersion curves. Axial rigidity values were obtained directly from extensional plate wave phase velocity. Excellent agreement (within 3%) of flexural rigidity values was obtained between NDE and mechanical testing for most panels. Transverse shear modulus values obtained from plate wave tests were within 4% of values obtained from through-thickness ultrasonic shear wave speed. Tensile and compressive axial rigidity values obtained from NDE were 22% to 41% higher than mechanical tension and compression test results. These differences between NDE and axial mechanical testing results are likely due to load-rate effects; however, these large differences were not apparent in the flexural and transverse shear comparisons. This fundamental research advances the state-of-the-art of NDE of wood-based composites by replacing empirical approaches with a technique based on fundamental mechanics, shear deformation laminated plate theory, and plate wave propagation theory.

Tucker, Brian J. (BATTELLE (PACIFIC NW LAB)); Bender, Donald A. (Washington State University); Pollock, David G. (Washington State University); Wolcott, Michael P. (Washington State University)

2003-04-01T23:59:59.000Z

114

Wave Dragon  

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

Overtopping Wave Devices Wave Dragon ApSLtd HWETTEI - Workshop October 26-28, 2005, Washington, DC Hydrokinetic Technologies Technical and Environmental Issues Workshop the Wave...

115

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 ï‚— Development of the HSS Deposition Velocity Safety Bulletin ï‚— 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

116

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

117

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

118

Coronal Seismology and the Propagation of Acoustic Waves Along Coronal Loops  

E-Print Network (OSTI)

We use a combination of analytical theory, numerical simulation, and data analysis to study the propagation of acoustic waves along coronal loops. We show that the intensity perturbation of a wave depends on a number of factors, including dissipation of the wave energy, pressure and temperature gradients in the loop atmosphere, work action between the wave and a flow, and the sensitivity properties of the observing instrument. In particular, the scale length of the intensity perturbation varies directly with the dissipation scale length (i.e., damping length) and the scale lengths of pressure, temperature, and velocity. We simulate wave propagation in three different equilibrium loop models and find that dissipation and pressure and temperature stratification are the most important effects in the low corona where the waves are most easily detected. Velocity effects are small, and cross-sectional area variations play no direct role for lines-of-sight that are normal to the loop axis. The intensity perturbation scale lengths in our simulations agree very well with the scale lengths we measure in a sample of loops observed by TRACE. The median observed value is 4.35x10^9 cm. In some cases the intensity perturbation increases with height, which is likely an indication of a temperature inversion in the loop (i.e., temperature that decreases with height). Our most important conclusion is that thermal conduction, the primary damping mechanism, is accurately described by classical transport theory. There is no need to invoke anomalous processes to explain the observations.

J. A. Klimchuk; S. E. M. Tanner; I. De Moortel

2004-12-03T23:59:59.000Z

119

HIGH-RESOLUTION SEISMIC VELOCITY AND ATTENUATION MODELS OF THE CAUCASUS-CASPIAN REGION  

SciTech Connect

The southwest edge of Eurasia is a tectonically and structurally complex region that includes the Caspian and Black Sea basins, the Caucasus Mountains, and the high plateaus south of the Caucasus. Using data from 25 broadband stations located in the region, new estimates of crustal and upper mantle thickness, velocity structure, and attenuation are being developed. Receiver functions have been determined for all stations. Depth to Moho is estimated using slant stacking of the receiver functions, forward modeling, and inversion. Moho depths along the Caspian and in the Kura Depression are in general poorly constrained using only receiver functions due to thick sedimentary basin sediments. The best fitting models suggest a low velocity upper crust with Moho depths ranging from 30 to 40 km. Crustal thicknesses increase in the Greater Caucasus with Moho depths of 40 to 50 km. Pronounced variations with azimuth of source are observed indicating 3D structural complexity and upper crustal velocities are higher than in the Kura Depression to the south. In the Lesser Caucasus, south and west of the Kura Depression, the crust is thicker (40 to 50 km) and upper crustal velocities are higher. Work is underway to refine these models with the event based surface wave dispersion and ambient noise correlation measurements from continuous data. Regional phase (Lg and Pg) attenuation models as well as blockage maps for Pn and Sn are being developed. Two methods are used to estimate Q: the two-station method to estimate inter-station Q and the reversed, two-station, two event method. The results are then inverted to create Lg and Pg Q maps. Initial results suggest substantial variations in both Pg and Lg Q in the region. A zone of higher Pg Q extends west from the Caspian between the Lesser and Greater Caucasus and a narrow area of higher Lg Q is observed.

Mellors, R; Gok, R; Pasyanos, M; Skobeltsyn, G; Teoman, U; Godoladze, T; Sandvol, E

2008-07-01T23:59:59.000Z

120

Hinsdale Wave Basin 1 | Open Energy Information  

Open Energy Info (EERE)

Hinsdale Wave Basin 1 Hinsdale Wave Basin 1 Jump to: navigation, search Basic Specifications Facility Name Hinsdale Wave Basin 1 Overseeing Organization Oregon State University Hydrodynamics Hydrodynamic Testing Facility Type Wave Basin Length(m) 104.0 Beam(m) 3.7 Depth(m) 4.6 Cost(per day) $3500 Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities Yes Maximum Wave Height(m) 1.8 Maximum Wave Height(m) at Wave Period(s) 10.0 Wave Period Range(s) 10.0 Current Velocity Range(m/s) 0.0 Programmable Wavemaking Yes Wavemaking Description Monochromatic waves (cnoidal, Stokes, Airy), solitary waves, user-defined free surface timeseries or board displacement timeseries for random waves Wave Direction Uni-Directional Simulated Beach Yes Description of Beach 12' by 12' concrete slabs anchored to flume walls

Note: This page contains sample records for the topic "wave velocity variations" 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

MODELING SUPER-FAST MAGNETOSONIC WAVES OBSERVED BY SDO IN ACTIVE REGION FUNNELS  

SciTech Connect

Recently, quasi-periodic, rapidly propagating waves have been observed in extreme ultraviolet by the Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA) instrument in about 10 flare/coronal mass ejection (CME) events thus far. A typical example is the 2010 August 1 C3.2 flare/CME event that exhibited arc-shaped wave trains propagating in an active region (AR) magnetic funnel with {approx}5% intensity variations at speeds in the range of 1000-2000 km s{sup -1}. The fast temporal cadence and high sensitivity of AIA enabled the detection of these waves. We identify them as fast magnetosonic waves driven quasi-periodically at the base of the flaring region and develop a three-dimensional MHD model of the event. For the initial state we utilize the dipole magnetic field to model the AR and include gravitationally stratified density at coronal temperature. At the coronal base of the AR, we excite the fast magnetosonic wave by periodic velocity pulsations in the photospheric plane confined to a funnel of magnetic field lines. The excited fast magnetosonic waves have similar amplitude, wavelength, and propagation speeds as the observed wave trains. Based on the simulation results, we discuss the possible excitation mechanism of the waves, their dynamical properties, and the use of the observations for coronal MHD seismology.

Ofman, L. [Department of Physics, Catholic University of America, Washington, DC 20064 (United States); Liu, W.; Title, A.; Aschwanden, M. [Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, CA 94304 (United States)

2011-10-20T23:59:59.000Z

122

Field Verification of ADCP Surface Gravity Wave Elevation Spectra  

Science Conference Proceedings (OSTI)

Acoustic Doppler current profilers (ADCPs) can measure orbital velocities induced by surface gravity waves, yet the ADCP estimates of these velocities are subject to a relatively high noise level. The present paper introduces a linear filtration ...

A. J. F. Hoitink; H. C. Peters; M. Schroevers

2007-05-01T23:59:59.000Z

123

Energy Flux and Wavelet Diagnostics of Secondary Mountain Waves  

Science Conference Proceedings (OSTI)

In recent years, aircraft data from mountain waves have been primarily analyzed using velocity and temperature power spectrum and momentum flux estimation. Herein it is argued that energy flux wavelets (i.e., pressure–velocity wavelet cross-...

Bryan K. Woods; Ronald B. Smith

2010-11-01T23:59:59.000Z

124

Hinsdale Wave Basin 2 | Open Energy Information  

Open Energy Info (EERE)

Wave Basin 2 Wave Basin 2 Jump to: navigation, search Basic Specifications Facility Name Hinsdale Wave Basin 2 Overseeing Organization Oregon State University Hydrodynamics Length(m) 48.8 Beam(m) 26.5 Depth(m) 2.1 Water Type Freshwater Cost(per day) $3500 Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities Yes Maximum Wave Height(m) 0.8 Maximum Wave Height(m) at Wave Period(s) 10.0 Wave Period Range(s) 10.0 Current Velocity Range(m/s) 0.0 Programmable Wavemaking Yes Wavemaking Description Monochromatic waves (cnoidal, Stokes, Airy), solitary waves, user-defined free surface timeseries or board displacement timeseries for random waves Wave Direction Both Simulated Beach Yes Description of Beach Built to client specifications, currently rigid concrete over gravel fill

125

Haynes Wave Basin | Open Energy Information  

Open Energy Info (EERE)

Wave Basin Wave Basin Jump to: navigation, search Basic Specifications Facility Name Haynes Wave Basin Overseeing Organization Texas A&M (Haynes) Hydrodynamic Testing Facility Type Wave Basin Length(m) 38.1 Beam(m) 22.9 Depth(m) 1.5 Water Type Freshwater Cost(per day) $150/hour (excluding labor) Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities Yes Maximum Wave Height(m) 0.6 Maximum Wave Height(m) at Wave Period(s) 3.3 Maximum Wave Length(m) 10.7 Wave Period Range(s) 3.3 Current Velocity Range(m/s) 0.2 Programmable Wavemaking Yes Wavemaking Description Directional, irregular, any spectrum, cnoidal or solitary wave Wave Direction Both Simulated Beach Yes Description of Beach Stone Channel/Tunnel/Flume Channel/Tunnel/Flume None

126

Rossby Waves in Zonal Barotropic Flows with Pseudocritical Levels  

Science Conference Proceedings (OSTI)

A pseudocritical level is defined as a region where the wave phase speed c equals the zonal basic flow velocity U and, additionally, the background potential vorticity gradient vanishes. In this study Rossby wave propagation is investigated in ...

Uwe Harlander

2002-09-01T23:59:59.000Z

127

Variational Interpolation of Circulation with Nonlinear, Advective Smoothing  

Science Conference Proceedings (OSTI)

A modified variational algorithm, previously proposed in meteorology, is presented for the interpolation of oceanic hydrographic and velocity data. The technique is anisotropic and involves a variational approach that allows revealing of the ...

G. G. Panteleev; N. A. Maximenko; B. deYoung; C. Reiss; T. Yamagata

2002-09-01T23:59:59.000Z

128

Alden Wave Basin | Open Energy Information  

Open Energy Info (EERE)

Wave Basin Wave Basin Jump to: navigation, search Basic Specifications Facility Name Alden Wave Basin Overseeing Organization Alden Research Laboratory, Inc Hydrodynamic Testing Facility Type Wave Basin Length(m) 33.5 Beam(m) 21.3 Depth(m) 1.2 Water Type Freshwater Cost(per day) Depends on study Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities Yes Maximum Wave Height(m) 0.3 Maximum Wave Height(m) at Wave Period(s) 1.0 Maximum Wave Length(m) 1.8 Wave Period Range(s) 1.0 Current Velocity Range(m/s) 0.0 Programmable Wavemaking Yes Wavemaking Description Period adjustable electronically, height adjustable mechanically Wave Direction Both Simulated Beach Yes Description of Beach Designed as needed using commercially available sand/sediment

129

White light velocity interferometer  

DOE Patents (OSTI)

The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s. 41 figs.

Erskine, D.J.

1997-06-24T23:59:59.000Z

130

White light velocity interferometer  

DOE Patents (OSTI)

The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s.

Erskine, David J. (Oakland, CA)

1997-01-01T23:59:59.000Z

131

White light velocity interferometer  

DOE Patents (OSTI)

The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s.

Erskine, David J. (Oakland, CA)

1999-01-01T23:59:59.000Z

132

White light velocity interferometer  

DOE Patents (OSTI)

The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s. 41 figs.

Erskine, D.J.

1999-06-08T23:59:59.000Z

133

Unitaxial constant velocity microactuator  

SciTech Connect

A uniaxial drive system or microactuator capable of operating in an ultra-high vacuum environment. 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-manometer 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.

McIntyre, Timothy J. (Knoxville, TN)

1994-01-01T23:59:59.000Z

134

Internal Waves in Monterey Submarine Canyon  

Science Conference Proceedings (OSTI)

Velocity, temperature, and salinity profile surveying in Monterey Submarine Canyon during spring tide reveals an internal wave field almost an order of magnitude more energetic than that in the open ocean. Semidiurnal fluctuations and their ...

Eric Kunze; Leslie K. Rosenfeld; Glenn S. Carter; Michael C. Gregg

2002-06-01T23:59:59.000Z

135

Strong Turbulence in the Wave Crest Region  

Science Conference Proceedings (OSTI)

High-resolution vertical velocity profiles in the surface layer of a lake reveal the turbulence structure beneath strongly forced waves. Dissipation rates of turbulence kinetic energy are estimated based on centered second-order structure ...

Johannes Gemmrich

2010-03-01T23:59:59.000Z

136

Shear Excitation of Atmospheric Gravity Waves  

Science Conference Proceedings (OSTI)

Unstable Velocity shears are a Common source of vertically propagating gravity waves in the atmosphere. However, the growth rates of unstable modes predicted by linear theory cannot always amount for their observed importance.

David C. Fritts

1982-09-01T23:59:59.000Z

137

Internal Gravity Wave Generation and Hydrodynamic Instability  

Science Conference Proceedings (OSTI)

Two mechanisms are proposed whereby internal gravity waves (IGW) may radiate from a linearly unstable region of Boussinesq parallel flow that is characterized in the far field by constant horizontal velocity and Brunt-Väisälä frequency. Through ...

B. R. Sutherland; C. P. Caulfield; W. R. Peltier

1994-11-01T23:59:59.000Z

138

Energy Dispersion in African Easterly Waves  

Science Conference Proceedings (OSTI)

The existence of an upstream (eastward) group velocity for African easterly waves (AEWs) is shown based on single-point lag regressions using gridded reanalysis data from 1990 to 2010. The eastward energy dispersion is consistent with the ...

Michael Diaz; Anantha Aiyyer

2013-01-01T23:59:59.000Z

139

Plasma beat-wave accelerator  

Science Conference Proceedings (OSTI)

We perform an analytic study of some quantities relevant to the plasma beat-wave accelerator (PBWA) concept. We obtain analytic expressions for the plasma frequency, longitudinal electron velocity, plasma density and longitudinal plasma electric field of a nonlinear longitudinal electron plasma oscillation with amplitude less than the wave-breaking limit and phase velocity approaching the speed of light. We also estimate the luminosity of a single-pass e/sup +/e/sup -/ linear PBWA collider assuming the energy and collision beamstrahlung are fixed parameters.

Noble, R.J.

1983-06-01T23:59:59.000Z

140

GyPSuM: A Detailed Tomographic Model of Mantle Density and Seismic Wave Speeds  

SciTech Connect

GyPSuM is a tomographic model fo mantle seismic shear wave (S) speeds, compressional wave (P) speeds and detailed density anomalies that drive mantle flow. the model is developed through simultaneous inversion of seismic body wave travel times (P and S) and geodynamic observations while considering realistic mineral physics parameters linking the relative behavior of mantle properties (wave speeds and density). Geodynamic observations include the (up to degree 16) global free-air gravity field, divergence of the tectonic plates, dynamic topography of the free surface, and the flow-induced excess ellipticity of the core-mantle boundary. GyPSuM is built with the philosophy that heterogeneity that most closely resembles thermal variations is the simplest possible solution. Models of the density field from Earth's free oscillations have provided great insight into the density configuration of the mantle; but are limited to very long-wavelength solutions. Alternatively, simply scaling higher resolution seismic images to density anomalies generates density fields that do not satisfy geodynamic observations. The current study provides detailed density structures in the mantle while directly satisfying geodynamic observations through a joint seismic-geodynamic inversion process. Notable density field observations include high-density piles at the base of the superplume structures, supporting the fundamental results of past normal mode studies. However, these features are more localized and lower amplitude than past studies would suggest. When we consider all seismic anomalies in GyPSuM, we find that P and S-wave speeds are strongly correlated throughout the mantle. However, correlations between the high-velocity S zones in the deep mantle ({approx} 2000 km depth) and corresponding P-wave anomalies are very low suggesting a systematic divergence from simplified thermal effects in ancient subducted slab anomalies. Nevertheless, they argue that temperature variations are the primary cause of P-wave, S-wave, and density anomalies in the mantle.

Simmons, N A; Forte, A M; Boschi, L; Grand, S P

2010-03-30T23:59:59.000Z

Note: This page contains sample records for the topic "wave velocity variations" 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

Fast wave current drive system design for DIII-D  

SciTech Connect

DIII-D has a major effort underway to develop the physics and technology of fast wave electron heating and current drive in conjunction with electron cyclotron heating. The present system consists of a four strap antenna driven by one 2 MW transmitter in the 32--60 MHz band. Experiments have been successful in demonstrating the physics of heating and current drive. In order to validate fast wave current drive for future machines a greater power capability is necessary to drive all of the plasma current. Advanced tokamak modeling for DIII-D has indicated that this goal can be met for plasma configurations of interest (i.e. high [beta] VH-mode discharges) with 8 MW of transmitter fast wave capability. It is proposed that four transmitters drive fast wave antennas at three locations in DIII-D to provide the power for current drive and current profile modification. As the next step in acquiring this capability, two modular four strap antennas are in design and the procurement of a high power transmitter in the 30--120 MHz range is in progress. Additionally, innovations in the technology are being investigated, such as the use of a coupled combine antenna to reduce the number of required feedthroughs and to provide for parallel phase velocity variation with a relatively small change in frequency, and the use of fast ferrite tuners to provide millisecond timescale impedance matching. A successful test of a low power fast ferrite prototype was conducted on DIII-D.

deGrassie, J.S.; Callis, R.; Lin-Liu, Y.R.; Moeller, C..; Petty, C.C.; Phelps, D.R.; Pinsker, R.I.; Remsen, D. (General Atomics, San Diego, CA (United States)); Baity, F.W.; Hoffman, D.J.; Taylor, D.J. (Oak Ridge National Lab., TN (United States)); Arnold, W.; Martin, S. (ANT-Nachrichtentechnik GmbH, Backnang (Germany))

1992-09-01T23:59:59.000Z

142

Fast wave current drive system design for DIII-D  

SciTech Connect

DIII-D has a major effort underway to develop the physics and technology of fast wave electron heating and current drive in conjunction with electron cyclotron heating. The present system consists of a four strap antenna driven by one 2 MW transmitter in the 32--60 MHz band. Experiments have been successful in demonstrating the physics of heating and current drive. In order to validate fast wave current drive for future machines a greater power capability is necessary to drive all of the plasma current. Advanced tokamak modeling for DIII-D has indicated that this goal can be met for plasma configurations of interest (i.e. high {beta} VH-mode discharges) with 8 MW of transmitter fast wave capability. It is proposed that four transmitters drive fast wave antennas at three locations in DIII-D to provide the power for current drive and current profile modification. As the next step in acquiring this capability, two modular four strap antennas are in design and the procurement of a high power transmitter in the 30--120 MHz range is in progress. Additionally, innovations in the technology are being investigated, such as the use of a coupled combine antenna to reduce the number of required feedthroughs and to provide for parallel phase velocity variation with a relatively small change in frequency, and the use of fast ferrite tuners to provide millisecond timescale impedance matching. A successful test of a low power fast ferrite prototype was conducted on DIII-D.

deGrassie, J.S.; Callis, R.; Lin-Liu, Y.R.; Moeller, C..; Petty, C.C.; Phelps, D.R.; Pinsker, R.I.; Remsen, D. [General Atomics, San Diego, CA (United States); Baity, F.W.; Hoffman, D.J.; Taylor, D.J. [Oak Ridge National Lab., TN (United States); Arnold, W.; Martin, S. [ANT-Nachrichtentechnik GmbH, Backnang (Germany)

1992-09-01T23:59:59.000Z

143

DeFrees Large Wave Basin | Open Energy Information  

Open Energy Info (EERE)

Large Wave Basin Large Wave Basin Jump to: navigation, search Basic Specifications Facility Name DeFrees Large Wave Basin Overseeing Organization Cornell University Hydrodynamics Hydrodynamic Testing Facility Type Wave Basin Length(m) 32.0 Beam(m) 0.6 Depth(m) 0.9 Water Type Freshwater Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities Yes Maximum Wave Height(m) 0.5 Maximum Wave Height(m) at Wave Period(s) 3.0 Maximum Wave Length(m) 64 Wave Period Range(s) 3.0 Current Velocity Range(m/s) 0.0 Programmable Wavemaking Yes Wavemaking Description Computer controlled 4m hydraulic wave paddle stroke allows a series of solitary waves to be generated; arbitrary wave shape possible Wave Direction Uni-Directional Simulated Beach Yes

144

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

145

MAGNETIC METHOD FOR PRODUCING HIGH VELOCITY SHOCK WAVES IN GASES  

DOE Patents (OSTI)

A device is described for producing high-energy plasmas comprising a tapered shock tube of dielectric material and having a closed small end, an exceedingly low-inductance coll supported about and axially aligned with the small end of the tapered tube. an elongated multiturn coil supported upon the remninder of the exterior wall of the shock tube. a potential source and switch connected in series with the low-inductance coil, a potential source and switch connected in series with the elongated coil, means for hermetically sealing the large end of the tube, means for purging the tube of gases, and means for admitting a selected gas into the shock tube.

Josephson, V.

1960-01-26T23:59:59.000Z

146

APPARATUS FOR PRODUCING HIGH VELOCITY SHOCK WAVES IN GASES  

DOE Patents (OSTI)

>A device for producing a high-energy ionized gas region comprises an evacuated tapered insulating vessel and a substantially hemispherical insulating cap hermetically affixed to the large end of the vessel, an annular electrode having a diameter equal to and supported in the interior wall of the vessel at the large end and having a conductive portion inside the vessel, a second electrode supported at the small end of the vessel, means connected to the vessel for introducing a selected gas therein, a source of high potential having two poles. means for connecting one pole of the high potential source to the annular electrode, and means for connecting the other pole of the potential source to the second electrode.

Scott, F.R.; Josephson, V.

1960-02-01T23:59:59.000Z

147

Is there Lower Limit to Velocity or Velocity Change?  

E-Print Network (OSTI)

Here we explore the possibility of a lower limit to velocity or velocity change which is 20 orders of magnitude smaller than the speed of light and explore the various observable signatures including those in cosmic rays and gamma ray bursts.

B. N. Sreenath; Kenath Arun; C. Sivaram

2012-09-17T23:59:59.000Z

148

Wave Energy  

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

Wave energy technologies extract energy directly from surface waves or from pressure fluctuations below the surface. Renewable energy analysts believe there is enough energy in ocean waves to provide up to 2 terawatts of electricity. (A terawatt is equal to a trillion watts.)

149

Midwinter Suppression of Baroclinic Wave Activity in the Pacific  

Science Conference Proceedings (OSTI)

Seasonal variations in baroclinic wave activity and jet stream structure in the Northern Hemisphere are investigated based upon over 20 years of daily data. Baroclinic wave activity at each grid point is represented for each day by an envelope ...

Hisashi Nakamura

1992-09-01T23:59:59.000Z

150

Dispersion of Small Suspended Particles in a Wave Boundary Layer  

Science Conference Proceedings (OSTI)

The dispersion of heavy suspensions in a wave boundary layer over a nonerodible bed is examined theoretically. Focusing attention on the horizontal variation of the ambient wave pattern, an effective convection-diffusion equation is derived by ...

Chiang C. Mei; Chimin Chian

1994-12-01T23:59:59.000Z

151

Structure of Intraseasonal Kelvin Waves in the Equatorial Pacific Ocean  

Science Conference Proceedings (OSTI)

Previous studies have shown that intraseasonal Kelvin waves are a prominent mode of variability in the eastern and central equatorial Pacific. These waves appear to be remotely forced by wind variations in the western Pacific and propagate ...

Eric S. Johnson; Michael J. Mc Phaden

1993-04-01T23:59:59.000Z

152

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

2013-08-28T23:59:59.000Z

153

OTRC Wave Basin | Open Energy Information  

Open Energy Info (EERE)

OTRC Wave Basin OTRC Wave Basin Jump to: navigation, search Basic Specifications Facility Name OTRC Wave Basin Overseeing Organization Texas A&M (OTRC) Hydrodynamic Testing Facility Type Wave Basin Length(m) 45.7 Beam(m) 30.5 Depth(m) 5.8 Water Type Freshwater Cost(per day) $300/hour (excluding labor) Special Physical Features 4.6m wide x 9.1m long x 16.8m deep pit with adjustable depth floor in test area Towing Capabilities Towing Capabilities Yes Maximum Velocity(m/s) 0.6 Length of Effective Tow(m) 27.4 Wavemaking Capabilities Wavemaking Capabilities Yes Maximum Wave Height(m) 0.9 Maximum Wave Height(m) at Wave Period(s) 4.0 Maximum Wave Length(m) 25 Wave Period Range(s) 4.0 Current Velocity Range(m/s) 0.6 Programmable Wavemaking Yes Wavemaking Description GEDAP 3D wave generation software, 48 hinged flap wave generator

154

Velocity shear-induced effects on electrostatic ion perturbations  

Science Conference Proceedings (OSTI)

Linear evolution of electrostatic perturbations in an unmagnetized electron{endash}ion plasma shear flow is studied. New physical effects, arising due to the non-normality of linear dynamics are disclosed. A new class of {ital nonperiodic collective mode} with vortical motion of ions, characterized by intense energy exchange with the mean flow, is found. It is also shown that the velocity shear induces extraction of the mean flow energy by ion-sound waves and that during the shear-induced evolution the ion-sound waves turn eventually into ion plasma oscillations. {copyright} {ital 1997 American Institute of Physics.}

Rogava, A.D. [Department of Physics, Tbilisi State University, and Department of Theoretical Astrophysics, Abastumani Astrophysical Observatory, Tbilisi, Republic of (Georgia)] [Department of Physics, Tbilisi State University, and Department of Theoretical Astrophysics, Abastumani Astrophysical Observatory, Tbilisi, Republic of (Georgia); Chagelishvili, G.D. [Department of Theoretical Astrophysics, Abastumani Astrophysical Observatory, Tbilisi, Republic of (Georgia)] [Department of Theoretical Astrophysics, Abastumani Astrophysical Observatory, Tbilisi, Republic of (Georgia); [Department of Cosmogeophysics, Space Research Institute, Moscow (Russia); Berezhiani, V.I. [Department of Plasma Physics, Institute of Physics, Tbilisi, Republic of (Georgia)] [Department of Plasma Physics, Institute of Physics, Tbilisi, Republic of (Georgia)

1997-12-01T23:59:59.000Z

155

Ship Waves and Lee Waves  

Science Conference Proceedings (OSTI)

Three-dimensional internal trapped lee wave modes produced by an isolated obstacle in a stratified fluid are shown to have dynamics analogous to surface ship waves on water of finite depth. Two models which allow for vertical trapping of wave ...

R. D. Sharman; M. G. Wurtele

1983-02-01T23:59:59.000Z

156

Extreme wave impinging and overtopping  

E-Print Network (OSTI)

This investigates the velocity fields of a plunging breaking wave impinging on a structure through measurements in a two-dimensional wave tank. As the wave breaks and overtops the structure, so-called green water is generated. The flow becomes multi-phased and chaotic as a highly aerated region is formed in the flow in the vicinity of the structure while water runs up onto the structure. In this study, particle image velocimetry (PIV) was employed to measure the velocity field of the water dominant region. For measurements of an aerated region that cannot be measured by PIV, a new measurement method called bubble image velocimetry (BIV) was developed. The principle and setup of the BIV method were introduced and validated. Mean and turbulence properties were obtained through ensemble averaging repeated tests measured by both methods. The dominant and maximum velocity of the breaking wave and associated green water are discussed for the three distinct phases of the impingement-runup-overtopping sequence. The distribution of the green water velocity along the top of the structure has a nonlinear profile and the maximum velocity occurs near the front of the fast moving water. Using the measured data and applying dimensional analysis, a similarity profile for the green water flow on top of the structure was obtained, and a prediction equation was formulated. The dam breaking solution used for the green water prediction was examined with determining initial water depth based on the experiment conditions. Comparison between measurements, the prediction equation, and the dam breaking flow was made. The prediction equation and the dam break flow with appropriate initial water depth may be used to predict the green water velocity caused by extreme waves in a hurricane. To demonstrate the aeration of the breaking wave and overtopping water, void fraction was also investigated. There is strong aeration in the region of overtopping water front generated by a plunging breaker. Void fraction of overtopping water was measured using a fiber optic reflectometer (FOR). The measured velocity and void fraction were also used to estimate flow rate and water volume of overtopping water.

Ryu, Yong Uk

2006-08-01T23:59:59.000Z

157

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

158

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 +

159

Excitation of fast waves by slow waves near the lower-hybrid frequency  

SciTech Connect

Resonant and non-resonant decays of short wavelength lower hybrid waves into long wave-length whistler waves and ion acoustic waves are considered. It is shown that the dominant coupling to the ion acoustic mode arises from the magnetic force producing a pressure variation along the magnetic field lines. The growth rate and the threshold condition for this decay instability compare favorably with other decay instabilities near the lower-hybrid frequency. (auth)

Berger, R. L.; Chen, L.

1976-02-01T23:59:59.000Z

160

Observations of Near-Surface Oceanic Velocity Strain-Rate Variability during and after Storm Events  

Science Conference Proceedings (OSTI)

During August of 1977, a series of repeated profiles of the upper ocean were made at Ocean Station Papa (145°W, 50°N) with a velocity/temperature microstructure profiler. A strong correlation of wind-speed variations with velocity structures in ...

R. Eward Lange

1981-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "wave velocity variations" 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

Velocity and Attenuation Structure of the Geysers Geothermal Field, California  

DOE Green Energy (OSTI)

The Geysers geothermal field is located in northern California and is one of the world's largest producers of electricity from geothermal energy. The resource consists of primarily dry steam which is produced from a low, porosity fractured graywacke. Over the last several years steam pressure at the Geysers has been dropping. Concern over decline of the resource has prompted research to understand its fundamental nature. A key issue is the distribution of fluid in the matrix of the reservoir rock. In this paper we interpret seismic compressional-wave velocity and attenuation data at the Geysers in terms of the geologic structure and fluid saturation in the reservoir. Our data consist of approximately 300 earthquakes that are of magnitude 1.2 and are distributed in depth between sea level and 2.5 km. Using compressional-wave arrival times, we invert for earthquake location, origin time, and velocity along a three-dimensional grid. Using the initial pulse width of the compressional-wave, we invert for the initial pulse width associated with the source, and the one-dimensional Q structure. We find that the velocity structure correlates with known mapped geologic units, including a velocity high that is correlated with a felsite body at depth that is known from drilling. The dry steam reservoir, which is also known from drilling, is mostly correlated with low velocity. The Q increases with depth to the top of the dry steam reservoir and decreases with depth within the reservoir. The decrease of Q with depth probably indicates that the saturation of the matrix of the reservoir rock increases with depth.

Zucca, J. J.; Hutchings, L. J.; Kasameyer, P. W.

1993-01-01T23:59:59.000Z

162

DeFrees Small Wave Basin | Open Energy Information  

Open Energy Info (EERE)

Wave Basin Wave Basin Jump to: navigation, search Basic Specifications Facility Name DeFrees Small Wave Basin Overseeing Organization Cornell University Hydrodynamics Hydrodynamic Testing Facility Type Wave Basin Length(m) 15.0 Beam(m) 0.8 Depth(m) 0.9 Water Type Freshwater Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities Yes Maximum Wave Height(m) 0.3 Maximum Wave Height(m) at Wave Period(s) 3.0 Maximum Wave Length(m) 30 Wave Period Range(s) 3.0 Current Velocity Range(m/s) 0.0 Programmable Wavemaking Yes Wavemaking Description Computer controlled hydraulic paddle, arbitrary wave shape possible Wave Direction Uni-Directional Simulated Beach Yes Description of Beach 1:10 sloping glass with dissipative horsehair covering if needed

163

Derivation of transformation equations for the parameters that characterize a plane acoustic wave without using phase invariance and Lorentz-Einstein transformation  

E-Print Network (OSTI)

We show that the transformation equations for the parameters that characterize a plane acoustic wave: period, (frequency), wave vector, wave length and phase velocity can be derived without using phase invariance and Lorentz-Einstein transformation

Bernhard Rothenstein

2005-06-20T23:59:59.000Z

164

Wind Forced Internal Waves in the North Pacific and Sargasso Sea  

Science Conference Proceedings (OSTI)

The three-dimensional structure of the near-inertial frequency internal wave field was measured at two open ocean sites using expendable velocity profilers. Both wave fields appear to be dominantly wind forced although their vertical structure ...

Eric A. D'Asaro

1984-04-01T23:59:59.000Z

165

The Direct Estimation of Near-Bottom Turbulent Fluxes in the Presence of Energetic Wave Motions  

Science Conference Proceedings (OSTI)

Velocities produced by energetic waves can contaminate direct covariance estimates of near-bottom turbulent shear stress and turbulent heat flux. A new adaptive filtering technique is introduced to minimize the contribution of wave-induced ...

W. J. Shaw; J. H. Trowbridge

2001-09-01T23:59:59.000Z

166

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

167

Barotropic Continental Shelf Waves on a ?-Plane  

Science Conference Proceedings (OSTI)

In this paper we consider the effect of the variation of the Coriolis parameter with latitude on barotropic shelf waves, using a ?-plane model. Solutions are constructed using the method of inner and outer asymptotic expansions, where the inner ...

A. Dorr; R. Grimshaw

1986-08-01T23:59:59.000Z

168

Original articles: Intelligent multichannel sensors for pulse wave analysis  

Science Conference Proceedings (OSTI)

Aortic pulse wave velocity is an independent predictive indicator for all cause mortality and cardiovascular morbidity. Unfortunately it is only invasively accessible and thus the A. carotis-A. femoralis pulse wave velocity (cfPWV) is recommended as ... Keywords: Arterial stiffness, BP, Cardiovascular risk, ECG, Electrocardiography, FIR, ICA, INA, Idxao, Idxo, Idxs, LED, PTT, PW, PWV, Pulse transit time, Pulse wave velocity, SD, cfPWV, dBP, p'(Idxo), p'(Idxs), p(Idxo), p(Idxs), sBP

S. Rosenkranz; C. Mayer; J. Kropf; S. Wassertheurer

2011-11-01T23:59:59.000Z

169

Simulation of anisotropic wave propagation in Vertical Seismic Profiles  

E-Print Network (OSTI)

The influence of elastic anisotropy on seismic wave propagation is often neglected for the sake of simplicity. However, ignoring anisotropy may lead to significant errors in the processing of seismic data and ultimately in a poor image of the subsurface. This is especially true in wide-aperture Vertical Seismic Profiles where waves travel both vertically and horizontally. Anisotropy has been neglected in wavefront construction methods of seismic ray-tracing until Gibson (2000), who showed they are powerful tools to simulate seismic wave propagation in three-dimensional anisotropic subsurface models. The code is currently under development using a C++ object oriented programming approach because it provides high flexibility in the design of new components and facilitates debugging and maintenance of a complex algorithm. So far, the code was used to simulate propagation in homogeneous or simple heterogeneous anisotropic velocity models mainly designed for testing purposes. In particular, it has never been applied to simulate a field dataset. We propose here an analytical method involving little algebra and that allows the design of realistic heterogeneous anisotropic models using the C++ object oriented programming approach. The new model class can model smooth multi-layered subsurface with gradients or models with many dip variations. It has been used to model first arrival times of a wide-aperture VSP dataset from the Gulf of Mexico to estimate the amount of anisotropy. The proposed velocity model is transversely isotropic. The anisotropy is constant throughout the model and is defined via Thomsen's parameters. Values in the final model are epsilon = 0.055 and delta = -0.115. The model is compatible with the a priori knowledge of the local geology and reduces the RMS average time difference between measured and computed travel times by 51% in comparison to the initial isotropic model. These values are realistic and are similar to other measurements of anisotropy in the Gulf of Mexico.

Durussel, Vincent Bernard

2002-08-01T23:59:59.000Z

170

Dual output acoustic wave sensor for molecular identification  

DOE Patents (OSTI)

The invention comprises a method for the identification and quantification of sorbed chemical species onto a coating of a device capable of generating and receiving an acoustic wave, by measuring the changes in the velocity of the acoustic wave resulting from the sorption of the chemical species into the coating as the wave travels through the coating and by measuring the changes in the attenuation of an acoustic wave resulting from the sorption of the chemical species into the coating as the wave travels through the coating. The inventive method further correlates the magnitudes of the changes of velocity with respect to changes of the attenuation of the acoustic wave to identify the sorbed chemical species. The absolute magnitudes of the velocity changes or the absolute magnitude of the attenuation changes are used to determine the concentration of the identified chemical species.

Frye, G.C.; Martin, S.J.

1990-10-03T23:59:59.000Z

171

Seismic velocity structure and microearthquake source properties at The Geysers, California, geothermal area  

DOE Green Energy (OSTI)

The method of progressive hypocenter-velocity inversion has been extended to incorporate S-wave arrival time data and to estimate S-wave velocities in addition to P-wave velocities. S-wave data to progressive inversion does not completely eliminate hypocenter-velocity tradeoffs, but they are substantially reduced. Results of a P and S-wave progressive hypocenter-velocity inversion at The Geysers show that the top of the steam reservoir is clearly defined by a large decrease of V/sub p//V/sub s/ at the condensation zone-production zone contact. The depth interval of maximum steam production coincides with minimum observed V/sub p//V/sub s/, and V/sub p//V/sub s/ increses below the shallow primary production zone suggesting that reservoir rock becomes more fluid saturated. The moment tensor inversion method was applied to three microearthquakes at The Geysers. Estimated principal stress orientations were comparable to those estimated using P-wave firstmotions as constraints. Well constrained principal stress orientations were obtained for one event for which the 17 P-first motions could not distinguish between normal-slip and strike-slip mechanisms. The moment tensor estimates of principal stress orientations were obtained using far fewer stations than required for first-motion focal mechanism solutions. The three focal mechanisms obtained here support the hypothesis that focal mechanisms are a function of depth at The Geysers. Progressive inversion as developed here and the moment tensor inversion method provide a complete approach for determining earthquake locations, P and S-wave velocity structure, and earthquake source mechanisms.

O'Connell, D.R.

1986-12-01T23:59:59.000Z

172

Seasonal Transport Variations of the Kuroshio: An OGCM Simulation  

Science Conference Proceedings (OSTI)

Numerical simulation is performed using a high-resolution ocean general circulation model to investigate seasonal variations of the Kuroshio transport. The simulated velocity profiles of the Kuroshio agree surprisingly well with ADCP observations ...

Takashi Kagimoto; Toshio Yamagata

1997-03-01T23:59:59.000Z

173

The Velocity-Selecting Cerenkov Counter  

E-Print Network (OSTI)

BAFFLE VELOCITY - SELECTING CERENKOV COUNTER (C 2) FiJI. 1velocity-selectinp: Cerenkov counter. ueaL-31;S CYLINDRICA~

Chamberlain, Owen; Weigand, Clyde

1956-01-01T23:59:59.000Z

174

Experimental Techniques for Measuring Temperature and Velocity...  

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

Measuring Temperature and Velocity Fields to Improve the Use and Validation of Building Heat Transfer Models Title Experimental Techniques for Measuring Temperature and Velocity...

175

The Generation of Random Variates From a Relativistic Maxwellian Distribution  

E-Print Network (OSTI)

A procedure for generating random variates from a relativistic Maxwellian distribution with arbitrary temperature and drift velocity is presented. The algorithm is based on the rejection method and can be used to initialize particle velocities in kinetic simulations of plasmas and gases.

Swisdak, M

2013-01-01T23:59:59.000Z

176

5-ft Wave Flume Facility | Open Energy Information  

Open Energy Info (EERE)

5-ft Wave Flume Facility 5-ft Wave Flume Facility Overseeing Organization United States Army Corp of Engineers (ERDC) Hydrodynamic Testing Facility Type Flume Length(m) 63.4 Beam(m) 1.5 Depth(m) 1.5 Water Type Freshwater Cost(per day) Contact POC Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities Yes Maximum Wave Height(m) 0.5 Maximum Wave Height(m) at Wave Period(s) 10.0 Wave Period Range(s) 10.0 Current Velocity Range(m/s) 0.0 Programmable Wavemaking Yes Simulated Beach No Channel/Tunnel/Flume Channel/Tunnel/Flume Yes Recirculating No Wind Capabilities Wind Capabilities None Control and Data Acquisition Description Automated data acquisition and control system Cameras None Available Sensors Flow, Pressure Range(psi), Turbulence, Velocity, Wave Probe

177

MHL 2D Wind/Wave | Open Energy Information  

Open Energy Info (EERE)

MHL 2D Wind/Wave MHL 2D Wind/Wave Jump to: navigation, search Basic Specifications Facility Name MHL 2D Wind/Wave Overseeing Organization University of Michigan Hydrodynamics Hydrodynamic Testing Facility Type Tunnel Length(m) 35.1 Beam(m) 0.7 Depth(m) 1.2 Cost(per day) $2000 (+ Labor/Materials) Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities Yes Maximum Wave Height(m) 0.2 Wave Period Range(s) 0.0 Current Velocity Range(m/s) 0.0 Programmable Wavemaking Yes Wavemaking Description Regular and irregular wave spectrum Wave Direction Uni-Directional Simulated Beach Yes Description of Beach Removable beach Channel/Tunnel/Flume Channel/Tunnel/Flume Yes Recirculating No Wind Capabilities Wind Capabilities Yes Wind Velocity Range(m/s) 20.4

178

3-ft Wave Flume Facility | Open Energy Information  

Open Energy Info (EERE)

3-ft Wave Flume Facility 3-ft Wave Flume Facility Overseeing Organization United States Army Corp of Engineers (ERDC) Hydrodynamic Testing Facility Type Flume Length(m) 45.1 Beam(m) 0.9 Depth(m) 0.9 Water Type Freshwater Cost(per day) Contact POC Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities Yes Maximum Wave Height(m) 0.2 Maximum Wave Height(m) at Wave Period(s) 10.0 Wave Period Range(s) 10.0 Current Velocity Range(m/s) 0.0 Programmable Wavemaking Yes Simulated Beach No Channel/Tunnel/Flume Channel/Tunnel/Flume None Wind Capabilities Wind Capabilities None Control and Data Acquisition Description Automated data acquisition and control system Cameras None Available Sensors Flow, Pressure Range(psi), Turbulence, Velocity, Wave Probe

179

University of Iowa Wave Basin | Open Energy Information  

Open Energy Info (EERE)

University of Iowa Wave Basin University of Iowa Wave Basin Overseeing Organization University of Iowa Hydrodynamic Testing Facility Type Wave Basin Length(m) 40.0 Beam(m) 20.0 Depth(m) 3.0 Cost(per day) Contact POC Special Physical Features Towed 3DPIV; contactless motion tracking; free surface measurement mappingv Towing Capabilities Towing Capabilities Yes Maximum Velocity(m/s) 2.5 Length of Effective Tow(m) 25.0 Wavemaking Capabilities Wavemaking Capabilities Yes Maximum Wave Height(m) 0.6 Wave Period Range(s) 0.0 Current Velocity Range(m/s) 0.0 Programmable Wavemaking Yes Wavemaking Description Fully programmable for regular or irregular waves Wave Direction Uni-Directional Simulated Beach Yes Description of Beach Trusses overlaid with lattice and matting Channel/Tunnel/Flume

180

Meridional Localization of Planetary Waves in Stochastic Zonal Flows  

Science Conference Proceedings (OSTI)

The effect of stochastic fluctuations in the zonal-mean velocity field on the energy dispersion of planetary stationary waves is considered, using the nondivergent, barotropic vorticity equation. It is found that for small noise levels, the ...

Adam Hugh Monahan; Lionel Pandolfo

2001-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "wave velocity variations" 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

Evidence for Barotropic Wave Radiation from the Gulf Stream  

Science Conference Proceedings (OSTI)

Highly energetic velocity fluctuations associated with topographic Rossby waves are frequently observed over the continental slope and rise off the United States and Canadian east coast. It has been suggested that the energy source for these ...

Amy S. Bower; Nelson G. Hogg

1992-01-01T23:59:59.000Z

182

Infragravity Edge Wave Observations on Two California Beaches  

Science Conference Proceedings (OSTI)

Wavenumber-frequency spectra of the infragravity (periods 20-200 sec) wave velocity field in the surf zone of two California beaches are estimated. Because the longshore arrays of biaxial electromagnetic current meters are relatively short (...

Joan Oltman-Shay; R. T. Guza

1987-05-01T23:59:59.000Z

183

Isothermal Plasma Waves in Gravitomagnetic Planar Analogue  

E-Print Network (OSTI)

We investigate the wave properties of the Kerr black hole with isothermal plasma using 3+1 ADM formalism. The corresponding Fourier analyzed perturbed GRMHD equations are used to obtain the dispersion relations. These relations lead to the real values of the components of wave vector $\\textbf{k}$ which are used to evaluate the quantities like phase and group velocities etc. These have been discussed graphically in the neighborhood of the pair production region. The results obtained verify the conclusion of Mackay et al. according to which rotation of a black hole is required for negative phase velocity propagation.

M. Sharif; Umber Sheikh

2007-09-15T23:59:59.000Z

184

Temporal Variations in Fibril Orientation  

E-Print Network (OSTI)

We measure variations in orientation of fourteen dynamic fibrils as a function of time in a small isolated plage and nearby network using a 10-min time sequence of H-alpha filtergrams obtained by the Dutch Open Telescope. We found motions with average angular velocities of the order of 1 deg/min suggesting systematic turning from one limit position to another, particularly apparent in the case of fibrils with lifetimes of a few minutes. Shorter fibrils tend to turn faster than longer ones, which we interpret as due to vortex flows in the underlying granulation that twist magnetic fields.

J. Koza; P. Sütterlin; A. Kucera; J. Rybák

2007-03-28T23:59:59.000Z

185

Statistical Errors in Variational Data Assimilation–A Theoretical One-Dimensional Analysis Applied to Doppler Wind Retrieval  

Science Conference Proceedings (OSTI)

When the velocity field is retrieved by a variational data assimilation method from the tracer (reflectivity) pattern movement observed by a Doppler radar, the accuracy of the retrieved velocity is affected by the observational error and data ...

Shuowen Yang; Qin Xu

1996-09-01T23:59:59.000Z

186

Waves in the chromosphere: observations  

E-Print Network (OSTI)

I review the literature on observational aspects of waves in the solar chromosphere in the first part of this contribution. High-frequency waves are invoked to build elaborate cool-star chromosphere heating theories but have not been detected decisively so far, neither as magnetic modes in network elements nor as acoustic modes in below-the-canopy internetwork regions. Three-minute upward-propagating acoustic shocks are thoroughly established through numerical simulation as the cause of intermittent bright internetwork grains, but their pistoning and their role in the low-chromosphere energy budget remain in debate. Three-minute wave interaction with magnetic canopies is a newer interest, presently progressing through numerical simulation. Three-minute umbral flashes and running penumbral waves seem a similar acoustic-shock phenomenon awaiting numerical simulation. The low-frequency network Doppler modulation remains enigmatic. In the second part, I address low-frequency ultraviolet brightness variations of t...

Rutten, R J

2010-01-01T23:59:59.000Z

187

L-Shaped Flume Wave Basin | Open Energy Information  

Open Energy Info (EERE)

L-Shaped Flume Wave Basin L-Shaped Flume Wave Basin Jump to: navigation, search Basic Specifications Facility Name L-Shaped Flume Wave Basin Overseeing Organization United States Army Corp of Engineers (ERDC) Hydrodynamic Testing Facility Type Wave Basin Length(m) 76.2 Beam(m) 15.2 Depth(m) 1.8 Water Type Freshwater Special Physical Features Contact POC Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities Yes Maximum Wave Height(m) 0.6 Maximum Wave Height(m) at Wave Period(s) 10.0 Wave Period Range(s) 10.0 Current Velocity Range(m/s) 0.0 Programmable Wavemaking Yes Wave Direction Uni-Directional Simulated Beach No Channel/Tunnel/Flume Channel/Tunnel/Flume None Wind Capabilities Wind Capabilities None Control and Data Acquisition Description Automated data acquisition and control sys

188

Control Of Gravitational Oscillations in Variational Data Assimilation  

Science Conference Proceedings (OSTI)

Variational four-dimensional data assimilation, combined with a penalty method constraining time derivatives of the surface pressure, the divergence, and the gravity-wave components is implemented on an adiabatic version of the National ...

X. Zou; I. M. Navon; J. Sela

1993-01-01T23:59:59.000Z

189

Method of accelerating photons by a relativistic plasma wave  

DOE Patents (OSTI)

Photons of a laser pulse have their group velocity accelerated in a plasma as they are placed on a downward density gradient of a plasma wave of which the phase velocity nearly matches the group velocity of the photons. This acceleration results in a frequency upshift. If the unperturbed plasma has a slight density gradient in the direction of propagation, the photon frequencies can be continuously upshifted to significantly greater values.

Dawson, John M. (Pacific Palisades, CA); Wilks, Scott C. (Santa Monica, CA)

1990-01-01T23:59:59.000Z

190

Lagrangian kinematics of steep waves up to the inception of a spilling breaker  

E-Print Network (OSTI)

Horizontal Lagrangian velocities and accelerations at the surface of steep water-waves are studied by Particle Tracking Velocimetry (PTV) for gradually increasing crest heights up to the inception of a spilling breaker. Localized steep waves are excited using wavemaker-generated Peregrine breather-type wave trains. Actual crest and phase velocities are estimated from video recorded sequences of the instantaneous wave shape as well as from surface elevation measurements by wave gauges. Effects of nonlinearity and spectral width on phase velocity, as well as relation between the phase velocity and crest propagation speed are discussed. The inception of a spilling breaker is associated with the horizontal velocity of water particles at the crest attaining that of the crest, thus confirming the kinematic criterion for inception of breaking.

Shemer, Lev

2013-01-01T23:59:59.000Z

191

Velocity-Space Proton Diffusion in the Solar Wind Turbulence  

E-Print Network (OSTI)

We study a velocity-space quasilinear diffusion of the solar wind protons driven by oblique Alfven turbulence at proton kinetic scales. Turbulent fluctuations at these scales possess properties of kinetic Alfven waves (KAWs) that are efficient in Cherenkov resonant interactions. The proton diffusion proceeds via Cherenkov kicks and forms a quasilinear plateau - nonthermal proton tail in the velocity distribution function (VDF). The tails extend in velocity space along the mean magnetic field from 1 to (1.5-3) VA, depending on the spectral break position, turbulence amplitude at the spectral break, and spectral slope after the break. The most favorable conditions for the tail generation occur in the regions where the proton thermal and Alfven velocities are about the same, VTp/VA = 1. The estimated formation times are within 1-2 h for typical tails at 1 AU, which is much shorter than the solar wind expansion time. Our results suggest that the nonthermal proton tails, observed in-situ at all heliocentric distan...

Voitenko, Yuriy

2013-01-01T23:59:59.000Z

192

Kinematics of Turbulence Convected by a Random Wave Field  

Science Conference Proceedings (OSTI)

Turbulent velocity spectra measured beneath wind waves show a large enhancement about the central wave frequency. A “5/3" frequency dependence can be seen both above and below the central peak, but with an apparent increase in spectral density at ...

J. L. Lumley; E. A. Terray

1983-11-01T23:59:59.000Z

193

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)

194

Variational formulations for resting irreversible fluids with heat flow  

Science Conference Proceedings (OSTI)

Nonequilibrium statistical mechanics helps to estimate corrections to the entropy and energy of the fluid with heat flux in terms of the nonequilibrium distribution function, f. This leads to the coefficients of wave model of heat: relaxation ... Keywords: conservation laws, entropy, grad solution, variational calculus, wave equations

Stanislaw Sieniutycz; Piotr Kuran

2008-09-01T23:59:59.000Z

195

Velocity Probability Density Functions for Oceanic Floats  

Science Conference Proceedings (OSTI)

Probability density functions (PDFs) of daily velocities from subsurface floats deployed in the North Atlantic and equatorial Atlantic Oceans are examined. In general, the PDFs are approximately Gaussian for small velocities, but with significant ...

Annalisa Bracco; J. H. LaCasce; Antonello Provenzale

2000-03-01T23:59:59.000Z

196

Equatorial Velocity Profiles. Part II: Zonal Component  

Science Conference Proceedings (OSTI)

Vertical profiles of horizontal velocity made along 53°E in the western Indian Ocean, during and after he onset of the southwest monsoon in 1976, show features in zonal velocity of relatively small vertical scale. Persistence of the features over ...

Kathleen O'Neill; James R. Luyten

1984-12-01T23:59:59.000Z

197

Determining Vertical Water Velocities from Seaglider  

Science Conference Proceedings (OSTI)

Vertical velocities in the world’s oceans are typically small, less than 1 cm s?1, posing a significant challenge for observational techniques. Seaglider, an autonomous profiling instrument, can be used to estimate vertical water velocity in the ...

Eleanor Frajka-Williams; Charles C. Eriksen; Peter B. Rhines; Ramsey R. Harcourt

2011-12-01T23:59:59.000Z

198

Velocity Probability Density Functions from Altimetry  

Science Conference Proceedings (OSTI)

Probability density functions (pdfs) are employed to evaluate the distribution of velocities in the global ocean. This study computes pdfs of ocean surface velocity using altimetric data from the TOPEX/Poseidon satellite. Results show that the ...

Sarah T. Gille; Stefan G. Llewellyn Smith

2000-01-01T23:59:59.000Z

199

Determining Velocities and Mixing Coefficients from Tracers  

Science Conference Proceedings (OSTI)

The effort to determine oceanic velocities from tracer distributions relies on a knowledge of the effects of mixing. However, the macroscopic diffusion coefficient, K, is generally not known and must be calculated along with the velocity. The ...

Jae Hak Lee; George Veronis

1989-04-01T23:59:59.000Z

200

An Acoustic Doppler and Electromagnetic Velocity Profiler  

Science Conference Proceedings (OSTI)

A freely failing current meter called the Absolute Velocity Profiler (AVP) is described. This profiler is an expansion of a previously developed instrument, the Electro-Magnetic Velocity Profiler (EMVP), with the additional capability of acoustic ...

Thomas B. Sanford; Robert G. Driver; John H. Dunlap

1985-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "wave velocity variations" 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

Equatorial Velocity Profiles. Part I: Meridional Component  

Science Conference Proceedings (OSTI)

A time series or vertical profiles of horizontal velocity was collected in the western equatorial Indian Ocean during late spring of 1976. The meridional velocity component is examined here, the zonal component in Part II of this paper. The ...

Kathleen O'Neill

1984-12-01T23:59:59.000Z

202

Waterspout Velocity Measurements by Airborne Doppler Lidar  

Science Conference Proceedings (OSTI)

A Doppler lidar measures the line-of-sight velocity of cloud droplets in a waterspout much as a meteorological Doppler radar measures the velocity of larger hydrometeors. We discuss details of the application of an airborne Doppler lidar to ...

R. L. Schwiesow; R. E. Cupp; P. C. Sinclair; R. F. Abbey Jr.

1981-04-01T23:59:59.000Z

203

Cold Plasma Wave Analysis in Magneto-Rotational Fluids  

E-Print Network (OSTI)

This paper is devoted to investigate the cold plasma wave properties. The analysis has been restricted to the neighborhood of the pair production region of the Kerr magnetosphere. The Fourier analyzed general relativistic magnetohydrodynamical equations are dealt under special circumstances and dispersion relations are obtained. We find the $x$-component of the complex wave vector numerically. The corresponding components of the propagation vector, attenuation vector, phase and group velocities are shown in graphs. The direction and dispersion of waves are investigated.

M. Sharif; Umber Sheikh

2010-05-25T23:59:59.000Z

204

Oceanic Internal Waves Are Not Weak Waves  

Science Conference Proceedings (OSTI)

It is shown that the oceanic internal wave field is too energetic by roughly two orders of magnitude to be treated theoretically as an assemblage of weakly interacting waves. This may be seen both from recent weak wave theoretical calculations ...

Greg Holloway

1980-06-01T23:59:59.000Z

205

Nonlinear Landau damping of transverse electromagnetic waves in dusty plasmas  

SciTech Connect

High-frequency transverse electromagnetic waves in a collisionless isotropic dusty plasma damp via nonlinear Landau damping. Taking into account the latter we have obtained a generalized set of Zakharov equations with local and nonlocal terms. Then from this coupled set of Zakharov equations a kinetic nonlinear Schroedinger equation with local and nonlocal nonlinearities is derived for special cases. It is shown that the modulation of the amplitude of the electromagnetic waves leads to the modulation instability through the nonlinear Landau damping term. The maximum growth rate is obtained for the special case when the group velocity of electromagnetic waves is close to the dust acoustic velocity.

Tsintsadze, N. L. [E. Andronikashvili Institute of Physics, Tbilisi 0171 (Georgia); Department of Physics, Government College University, Lahore 54000 (Pakistan); Salam Chair in Physics, Government College University, Lahore 54000 (Pakistan); Chaudhary, Rozina [Department of Physics, Government College University, Lahore 54000 (Pakistan); Salam Chair in Physics, Government College University, Lahore 54000 (Pakistan); Shah, H. A. [Department of Physics, Government College University, Lahore 54000 (Pakistan); Murtaza, G. [Salam Chair in Physics, Government College University, Lahore 54000 (Pakistan)

2009-04-15T23:59:59.000Z

206

Ion Bernstein wave heating research  

SciTech Connect

Ion Bernstein wave heating (IBWH) utilizes the ion Bernstein wave (IBW), a hot plasma wave, to carry the radio frequency (rf) power to heat tokamak reactor core. Earlier wave accessibility studies have shown that this finite-Larmor-radius (FLR) mode should penetrate into a hot dense reactor plasma core without significant attenuation. Moreover, the IBW`s low phase velocity ({omega}/k{sub {perpendicular}} {approx} V{sub Ti} {much_lt} V{sub {alpha}}) greatly reduces the otherwise serious wave absorption by the 3.5 MeV fusion {alpha}-particles. In addition, the property of IBW`s that k{sub {perpendicular}} {rho}{sub i} {approx} 1 makes localized bulk ion heating possible at the ion cyclotron harmonic layers. Such bulk ion heating can prove useful in optimizing fusion reactivity. In another vein, with proper selection of parameters, IBW`s can be made subject to strong localized electron Landau damping near the major ion cyclotron harmonic resonance layers. This property can be useful, for example, for rf current drive in the reactor plasma core. This paper discusses this research.

Ono, Masayuki

1992-03-01T23:59:59.000Z

207

Ion Bernstein wave heating research  

Science Conference Proceedings (OSTI)

Ion Bernstein wave heating (IBWH) utilizes the ion Bernstein wave (IBW), a hot plasma wave, to carry the radio frequency (rf) power to heat tokamak reactor core. Earlier wave accessibility studies have shown that this finite-Larmor-radius (FLR) mode should penetrate into a hot dense reactor plasma core without significant attenuation. Moreover, the IBW's low phase velocity ({omega}/k{sub {perpendicular}} {approx} V{sub Ti} {much lt} V{sub {alpha}}) greatly reduces the otherwise serious wave absorption by the 3.5 MeV fusion {alpha}-particles. In addition, the property of IBW's that k{sub {perpendicular}} {rho}{sub i} {approx} 1 makes localized bulk ion heating possible at the ion cyclotron harmonic layers. Such bulk ion heating can prove useful in optimizing fusion reactivity. In another vein, with proper selection of parameters, IBW's can be made subject to strong localized electron Landau damping near the major ion cyclotron harmonic resonance layers. This property can be useful, for example, for rf current drive in the reactor plasma core. This paper discusses this research.

Ono, Masayuki.

1992-03-01T23:59:59.000Z

208

Evolution of a Rossby Wave Packet in Barotropic Flows with Asymmetric Basic Current, Topography and ?-Effect  

Science Conference Proceedings (OSTI)

Using the Rossby wave packet approximation and the WKB method, the evolution of a single geostrophic synoptic disturbance has been studied. The structural changes of the wave packet due to the variation of ? with latitude, the asymmetric basic ...

Huijun Yang

1987-08-01T23:59:59.000Z

209

A Theory for the Statistical Equilibrium Energy Spectrum and Heat Flux Produced by Transient Baroclinic Waves  

Science Conference Proceedings (OSTI)

Obtaining a physically based understanding of the variations with spatial scale of the amplitude and dispersive properties of midlatitude transient baroclinic waves and the heat flux associated with these waves is a central goal of dynamic ...

Brian F. Farrell; Petros J. Ioannou

1994-10-01T23:59:59.000Z

210

Directional Wavelet Analysis of Inhomogeneity in the Surface Wave Field from Aerial Laser Scanning Data  

Science Conference Proceedings (OSTI)

Modern measurement techniques such as aerial laser scanning allow for rapid determination of the spatial variation of sea surface elevation. Wave fields obtained from such data show spatial inhomogeneity associated with the presence of wave ...

Richard M. Gorman; D. Murray Hicks

2005-06-01T23:59:59.000Z

211

VELOCITY INDICATOR FOR EXTRUSION PRESS  

DOE Patents (OSTI)

An indicator is presented for measuring the lowspeed velocity of an object in one direction where the object returns in the opposite direction at a high speed. The indicator comprises a drum having its axis of rotation transverse to the linear movement of the object and a tape wound upon the drum with its free end extending therefrom and adapted to be connected to the object. A constant torque is applied to the drum in a direction to wind the tape on the drum. The speed of the tape in the unwinding direction is indicated on a tachometer which is coupled through a shaft and clutch means to the drum only when the tape is unwinding.

Digney, F.J. Jr.; Bevilacqua, F.

1959-04-01T23:59:59.000Z

212

Plasma wave propagation with a plasma density gradient  

Science Conference Proceedings (OSTI)

Plasma waves with the plasma diffusion velocity u{sub n} due to a plasma density gradient are described in a positive column plasma. The ion wave is generated by the perturbation of the operating frequency 10{sup 6} s{sup -1} and it propagates with the group velocity u{sub g{approx}}c{sub s}{sup 2}/u{sub n{approx}}(10{sup 5}-10{sup 6}) m/s, where c{sub s} is the acoustic velocity in a fine tube fluorescent lamp, while the electron wave cannot be generated with a turbulence of low frequency less than the electron oscillation frequency {omega}{sub pe}. The propagation of the lighting signal observed in long tube fluorescent lamps is well understood with the propagation of ion waves occurring along the plasma density gradient.

Cho, Guangsup; Choi, Eun-Ha; Uhm, Han Sup [Department of Electrophysics, Kwangwoon University, 447-1 Nowon Wallgye, Seoul 139-701 (Korea, Republic of)

2011-03-15T23:59:59.000Z

213

Calculation of Extreme Wave Loads on Coastal Highway Bridges  

E-Print Network (OSTI)

Coastal bridges are exposed to severe wave, current and wind forces during a hurricane. Most coastal bridges are not designed to resist wave loads in such extreme situations, and there are no existing analytical methods to calculate wave loads on coastal highway bridges. This study focuses on developing a new scheme to estimate the extreme wave loads on bridges for designing purpose. In order to do this, a 2D wave velocity potential model (2D Model) is set up for the deterministic analysis of wave force on bridge decks. 2D Model is a linear wave model, which has the capability of calculating wave velocity potential components in time domain based on wave parameters such as wave height, wave period and water depth, and complex structural geometries. 2D Model has Laplace equation as general equation. The free surface boundary, incoming and outgoing wave boundary conditions are linearized, decomposed first, and then solved by the finite difference method. Maximum wave forces results calculated by the linear 2D Model are compared with results from CFD software Flow3D that is using Navier Stokes theory up to the 5th order; and 2D Model is validated by comparing results with experiment data. A case study is conducted for calculating extreme wave forces on I-10 Bridge across Escambia Bay, Florida during Hurricane Ivan in September 2004.SWAN model is adapted to investigate the parameters of wave heights and wave periods around bridge sites. SWAN model has the capability of predicting or hindcasting significant wave heights and wave periods as long as the domain and input parameters are given. The predicted significant wave heights are compared with measurements by Buoy Station 42039 and 42040 nearest to Escambia Bay. A new prediction equation of maximum uplift wave forces on bridge decks is developed in terms of wave height, wave period, water depth, bridge width, water clearance and over top water load. To develop the equations, the relationship is investigated between maximum uplift wave forces and wave parameters, water clearance, green water effects and bridge width. 2D Model is used for up to 1886 cases with difference parameters. Flow3D model is adopted to determine coefficients of water clearance and green water effects, which cannot be calculated by 2D Model.

Meng, Bo

2008-12-01T23:59:59.000Z

214

The collisions of high-velocity clouds with the galactic halo  

E-Print Network (OSTI)

Spiral galaxies are surrounded by a widely distributed hot coronal gas and seem to be fed by infalling clouds of neutral hydrogen gas with low metallicity and high velocities. We numerically study plasma waves produced by the collisions of these high-velocity clouds (HVCs) with the hot halo gas and with the gaseous disk. In particular, we tackle two problems numerically: 1) collisions of HVCs with the galactic halo gas and 2) the dispersion relations to obtain the phase and group velocities of plasma waves from the equations of plasma motion as well as further important physical characteristics such as magnetic tension force, gas pressure, etc. The obtained results allow us to understand the nature of MHD waves produced during the collisions in galactic media and lead to the suggestion that these waves can heat the ambient halo gas. These calculations are aiming at leading to a better understanding of dynamics and interaction of HVCs with the galactic halo and of the importance of MHD waves as a heating proce...

Jelinek, Petr; 10.1016/j.cpc.2011.01.023

2011-01-01T23:59:59.000Z

215

VELOCITY SELECTOR METHOD FOR THE SEPARATION OF ISOTOPES  

DOE Patents (OSTI)

A velocity selector apparatus is described for separating and collecting an enriched fraction of the isotope of a particular element. The invention has the advantage over conventional mass spectrometers in that a magnetic field is not used, doing away with the attendant problems of magnetic field variation. The apparatus separates the isotopes by selectively accelerating the ionized constituents present in a beam of the polyisotopic substance that are of uniform kinetic energy, the acceleration being applied intermittently and at spaced points along the beam and in a direction normal to the direction of the propagation of the uniform energy beam whereby a transverse displacement of the isotopic constituents of different mass is obtained.

Britten, R.J.

1957-12-31T23:59:59.000Z

216

Excavatability Assessment of Weathered Sedimentary Rock Mass Using Seismic Velocity Method  

SciTech Connect

Seismic refraction method is one of the most popular methods in assessing surface excavation. The main objective of the seismic data acquisition is to delineate the subsurface into velocity profiles as different velocity can be correlated to identify different materials. The physical principal used for the determination of excavatability is that seismic waves travel faster through denser material as compared to less consolidated material. In general, a lower velocity indicates material that is soft and a higher velocity indicates more difficult to be excavated. However, a few researchers have noted that seismic velocity method alone does not correlate well with the excavatability of the material. In this study, a seismic velocity method was used in Nusajaya, Johor to assess the accuracy of this seismic velocity method with excavatability of the weathered sedimentary rock mass. A direct ripping run by monitoring the actual production of ripping has been employed at later stage and compared to the ripper manufacturer's recommendation. This paper presents the findings of the seismic velocity tests in weathered sedimentary area. The reliability of using this method with the actual rippability trials is also presented.

Bin Mohamad, Edy Tonnizam; Noor, Muhazian Md; Isa, Mohamed Fauzi Bin Md.; Mazlan, Ain Naadia [Department of Geotechnics and Transportation, Faculty of Civil Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai. Johor (Malaysia); Saad, Rosli [Universiti Sains Malaysia, Penang (Malaysia)

2010-12-23T23:59:59.000Z

217

Locating an active fault zone in Coso geothermal field by analyzing seismic guided waves from microearthquake data  

DOE Green Energy (OSTI)

Active fault systems usually provide high-permeability channels for hydrothermal outflow in geothermal fields. Locating such fault systems is of a vital importance to plan geothermal production and injection drilling, since an active fault zone often acts as a fracture-extensive low-velocity wave guide to seismic waves. We have located an active fault zone in the Coso geothermal field, California, by identifying and analyzing a fault-zone trapped Rayleigh-type guided wave from microearthquake data. The wavelet transform is employed to characterize guided-wave's velocity-frequency dispersion, and numerical methods are used to simulate the guided-wave propagation. The modeling calculation suggests that the fault zone is {approx} 200m wide, and has a P wave velocity of 4.80 km/s and a S wave velocity of 3.00 km/s, which is sandwiched between two half spaces with relatively higher velocities (P wave velocity 5.60 km/s, and S wave velocity 3.20 km/s). zones having vertical or nearly vertical dipping fault planes.

SGP-TR-150-16

1995-01-26T23:59:59.000Z

218

Grading of lumber using stress waves  

E-Print Network (OSTI)

The goal of this research was to develop stress wave grading technology suitable for small lumber mills. Specific goals include: 1) develop an ultrasonic probe configuration to facilitate real-time grain angle and edge knot measurement, 2) determine the statistical correlation between localized stress wave indices and lumber tensile strength and 3) compare the ultrasonic technique with other nondestructive evaluation (NDE) measurements including static MOE, impact stress wave and transverse vibration. Two hundred pieces of 2 x 6 Southern Pine lumber were randomly sampled. Material properties and NDE measurements such as static MOE, impact stress wave and transverse vibration MOEs were collected for the lumber. Before proceeding with final ultrasonic testing, pilot studies were done to study the effect of the strength reducing factors, such as grain angle and edge knots, on ultrasonic wave velocity. Wave velocity decreased as grain angle increased, with more apparent loss taking place at lower angles. The presence of edge knots decreased the wave velocity as measured along the narrow edge of the lumber. Using the knowledge gained from the pilot studies an ultrasonic probe configuration was devised to detect gross grain angle and edge knots. The tests were carried on the lumber using the configuration. Statistical models from localized stress wave indices were developed to predict the tensile strength. The linear correlation between predicted and actual ultimate tensile strength was 0.724. Ultrasonic testing was a slightly better predictor of ultimate tensile strength than shortspan bending, impact stress wave and transverse vibration techniques which had linear correlations of 0.716, 0.696 and 0.716 respectively. Separately including impact stress wave and transverse vibration MOEs into the ultrasonic model resulted in improved linear correlations of 0.769 and 0.787, respectively. In summary, knowledge from this study will be useful in the continuing development of stress wave lumber grading technology. Even though the results were only slightly better than those with short span bending and transverse vibration techniques, the ultrasonic technique appears to be promising for grading of wood.

Bethi, Rajeshwar

1994-01-01T23:59:59.000Z

219

Co-existence of whistler waves with kinetic Alfven wave turbulence for the high-beta solar wind plasma  

SciTech Connect

It is shown that the dispersion relation for whistler waves is identical for a high or low beta plasma. Furthermore, in the high-beta solar wind plasma, whistler waves meet the Landau resonance with electrons for velocities less than the thermal speed, and consequently, the electric force is small compared to the mirror force. As whistlers propagate through the inhomogeneous solar wind, the perpendicular wave number increases through refraction, increasing the Landau damping rate. However, the whistlers can survive because the background kinetic Alfven wave (KAW) turbulence creates a plateau by quasilinear (QL) diffusion in the solar wind electron distribution at small velocities. It is found that for whistler energy density of only {approx}10{sup -3} that of the kinetic Alfven waves, the quasilinear diffusion rate due to whistlers is comparable to KAW. Thus, very small amplitude whistler turbulence can have a significant consequence on the evolution of the solar wind electron distribution function.

Mithaiwala, Manish; Crabtree, Chris; Ganguli, Gurudas [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375-5346 (United States); Rudakov, Leonid [Icarus Research Inc., P.O. Box 30780, Bethesda, Maryland 20824-0780 (United States)

2012-10-15T23:59:59.000Z

220

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

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


221

Influence of the inlet velocity profiles on the prediction of velocity distribution inside an electrostatic precipitator  

SciTech Connect

The influence of the velocity profile at the inlet boundary on the simulation of air velocity distribution inside an electrostatic precipitator is presented in this study. Measurements and simulations were performed in a duct and an electrostatic precipitator (ESP). A four-hole cobra probe was used for the measurement of velocity distribution. The flow simulation was performed by using the computational fluid dynamics (CFD) code FLUENT. Numerical calculations for the air flow were carried out by solving the Reynolds-averaged Navier-Stokes equations coupled with the realizable k-{epsilon} turbulence model equations. Simulations were performed with two different velocity profiles at the inlet boundary - one with a uniform (ideal) velocity profile and the other with a non-uniform (real) velocity profile to demonstrate the effect of velocity inlet boundary condition on the flow simulation results inside an ESP. The real velocity profile was obtained from the velocity measured at different points of the inlet boundary whereas the ideal velocity profile was obtained by calculating the mean value of the measured data. Simulation with the real velocity profile at the inlet boundary was found to predict better the velocity distribution inside the ESP suggesting that an experimentally measured velocity profile could be used as velocity inlet boundary condition for an accurate numerical simulation of the ESP. (author)

Haque, Shah M.E.; Deev, A.V.; Subaschandar, N. [Process Engineering and Light Metals (PELM) Centre, Faculty of Sciences, Engineering and Health, Central Queensland University, Gladstone, Queensland 4680 (Australia); Rasul, M.G.; Khan, M.M.K. [College of Engineering and Built Environment, Faculty of Sciences, Engineering and Health, Central Queensland University, Rockhampton, Queensland 4702 (Australia)

2009-01-15T23:59:59.000Z

222

Modeling fault-zone guided waves of microearthquakes in a geothermal  

Open Energy Info (EERE)

fault-zone guided waves of microearthquakes in a geothermal fault-zone guided waves of microearthquakes in a geothermal reservoir Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Modeling fault-zone guided waves of microearthquakes in a geothermal reservoir Details Activities (1) Areas (1) Regions (0) Abstract: Fault-zone guided waves have been identified in microearthquake seismograms recorded at the Coso Geothermal Field, California. The observed guided waves have particle motions and propagation group velocities similar to Rayleigh wave modes. A numerical method has been employed to simulate the guided-wave propagation through the fault zone. By comparing observed and synthetic waveforms the fault-zone width and its P- and S-wave velocity structure have been estimated. It is suggested here that the identification

223

STEREO QUADRATURE OBSERVATIONS OF THE THREE-DIMENSIONAL STRUCTURE AND DRIVER OF A GLOBAL CORONAL WAVE  

SciTech Connect

We present the first observations of a global coronal wave ('EIT wave') from the two STEREO satellites in quadrature. The wave's initiation site was at the disk center in STEREO-B and precisely on the limb in STEREO-A. These unprecedented observations from the STEREO Extreme Ultraviolet Imaging (EUVI) instruments enable us to gain insight into the wave's kinematics, initiation, and three-dimensional structure. The wave propagates globally over the whole solar hemisphere visible to STEREO-B with a constant velocity of {approx}263 +- 16 km s{sup -1}. From the two STEREO observations, we derive a height of the wave in the range of {approx}80-100 Mm. Comparison of the wave kinematics with the early phase of the erupting coronal mass ejection (CME) structure indicates that the wave is initiated by the CME lateral expansion, and then propagates freely with a velocity close to the fast magnetosonic speed in the quiet solar corona.

Kienreich, I. W.; Temmer, M.; Veronig, A. M., E-mail: ines.kienreich@uni-graz.a, E-mail: mat@igam.uni-graz.a, E-mail: asv@igam.uni-graz.a [Institute of Physics/IGAM, University of Graz, Universitaetsplatz 5, A-8010 Graz (Austria)

2009-10-01T23:59:59.000Z

224

1.5-ft Wave Flume Facility | Open Energy Information  

Open Energy Info (EERE)

-ft Wave Flume Facility -ft Wave Flume Facility Jump to: navigation, search Basic Specifications Facility Name 1.5-ft Wave Flume Facility Overseeing Organization United States Army Corp of Engineers (ERDC) Hydrodynamic Testing Facility Type Flume Length(m) 45.1 Beam(m) 0.5 Depth(m) 0.9 Water Type Freshwater Cost(per day) Contact POC Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities Yes Maximum Wave Height(m) 0.2 Maximum Wave Height(m) at Wave Period(s) 10.0 Wave Period Range(s) 10.0 Current Velocity Range(m/s) 0.0 Programmable Wavemaking Yes Simulated Beach No Channel/Tunnel/Flume Channel/Tunnel/Flume Yes Recirculating No Wind Capabilities Wind Capabilities None Control and Data Acquisition Description Automated data acquisition and control system

225

11-ft Wave Flume Facility | Open Energy Information  

Open Energy Info (EERE)

ft Wave Flume Facility ft Wave Flume Facility Jump to: navigation, search Basic Specifications Facility Name Wave Flume Facility Overseeing Organization United States Army Corp of Engineers (ERDC) Hydrodynamic Testing Facility Type Flume Length(m) 77.4 Beam(m) 3.4 Depth(m) 1.8 Water Type Freshwater Cost(per day) Contact POC Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities Yes Maximum Wave Height(m) 0.4 Maximum Wave Height(m) at Wave Period(s) 10.0 Wave Period Range(s) 10.0 Current Velocity Range(m/s) 0.0 Programmable Wavemaking Yes Simulated Beach No Channel/Tunnel/Flume Channel/Tunnel/Flume None Wind Capabilities Wind Capabilities Yes Control and Data Acquisition Description Automated data acquisition and control system Cameras None

226

10-ft Wave Flume Facility | Open Energy Information  

Open Energy Info (EERE)

ft Wave Flume Facility ft Wave Flume Facility Jump to: navigation, search Basic Specifications Facility Name 10-ft Wave Flume Facility Overseeing Organization United States Army Corp of Engineers (ERDC) Hydrodynamic Testing Facility Type Flume Length(m) 63.4 Beam(m) 3.0 Depth(m) 1.5 Water Type Freshwater Cost(per day) Contact POC Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities Yes Maximum Wave Height(m) 0.5 Maximum Wave Height(m) at Wave Period(s) 10.0 Wave Period Range(s) 0.0 Current Velocity Range(m/s) 0.0 Programmable Wavemaking Yes Simulated Beach No Channel/Tunnel/Flume Channel/Tunnel/Flume Yes Recirculating No Wind Capabilities Wind Capabilities None Control and Data Acquisition Description Automated data acquisition and control system

227

6-ft Wave Flume Facility | Open Energy Information  

Open Energy Info (EERE)

Wave Flume Facility Wave Flume Facility Jump to: navigation, search Basic Specifications Facility Name 6-ft Wave Flume Facility Overseeing Organization United States Army Corp of Engineers (ERDC) Hydrodynamic Testing Facility Type Flume Length(m) 105.2 Beam(m) 1.8 Depth(m) 1.8 Water Type Freshwater Cost(per day) Contact POC Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities Yes Maximum Wave Height(m) 0.4 Maximum Wave Height(m) at Wave Period(s) 10.0 Wave Period Range(s) 10.0 Current Velocity Range(m/s) 0.0 Programmable Wavemaking Yes Simulated Beach No Channel/Tunnel/Flume Channel/Tunnel/Flume Yes Recirculating No Wind Capabilities Wind Capabilities None Control and Data Acquisition Description Automated data acquisition and control system

228

Stable operating regime for traveling wave devices  

DOE Patents (OSTI)

Autophase stability is provided for a traveling wave device (TWD) electron beam for amplifying an RF electromagnetic wave in walls defining a waveguide for said electromagnetic wave. An off-axis electron beam is generated at a selected energy and has an energy noise inherently arising from electron gun. The off-axis electron beam is introduced into the waveguide. The off-axis electron beam is introduced into the waveguide at a second radius. The waveguide structure is designed to obtain a selected detuning of the electron beam. The off-axis electron beam has a velocity and the second radius to place the electron beam at a selected distance from the walls defining the waveguide, wherein changes in a density of the electron beam due to the RF electromagnetic wave are independent of the energy of the electron beam to provide a concomitant stable operating regime relative to the energy noise.

Carlsten, Bruce E. (Los Alamos, NM)

2000-01-01T23:59:59.000Z

229

The Annual Rossby Wave in the Central Equatorial Pacific Ocean  

Science Conference Proceedings (OSTI)

We attribute observed annual variations in the subthermocline thermal structure of the central equatorial Pacific to a forced gravest-meridional-mode Rossby wave. In the region between 300 and 800 m (where the Väisälä frequency varies slowly and ...

Roger Lukas; Eric Firing

1985-01-01T23:59:59.000Z

230

Super-light electromagnetic wave with longitudinal and transversal modes  

E-Print Network (OSTI)

The transformation converting equations invariant under Lorentz into the equations invariant under Galileo is obtained. On this basis: (1) the super-light electromagnetic wave with longitudinal and transversal modes is found out; (2) it is shown the wave velocity coincides with that of de Broglie's wave; (3) the connection between Maxwell's electrodynamics and Shredinger's equation is established; (4) structural elements of space are discovered and "a horizon of visibility" is found. It is shown Bell's inequalities and the principle of the light speed constancy are based on the SRT artifact and "Einstein's local realism" is determined by the wave referred above. Objectivity of results for quantum and classical objects is discussed

M. M. Kononenko

2007-08-20T23:59:59.000Z

231

Wave–Wave Interaction of Unstable Baroclinic Waves  

Science Conference Proceedings (OSTI)

Two slightly unstable baroclinic waves in the two-layer Phillips model are allowed to interact with each other as well as the mean flow. A theory for small dissipation rates is developed to examine the role of wave–wave interaction in the ...

Joseph Pedlosky; Lorenzo M. Polvani

1987-02-01T23:59:59.000Z

232

Mean Vertical Velocities Measured by Indian MST Radar and Comparison with Indirectly Computed Values  

Science Conference Proceedings (OSTI)

Mean vertical velocities and their variations observed with Indian mesosphere–stratosphere–troposphere (MST) radar located at Gadanki (13.5°N, 79.2°E), a tropical station in India, are presented. In this study, a comparison has been made between ...

V. V. M. Jagannadha Rao; D. Narayana Rao; M. Venkat Ratnam; K. Mohan; S. Vijaya Bhaskar Rao

2003-04-01T23:59:59.000Z

233

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

234

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

235

Wave-Driven Rotation In Centrifugal Mirrors  

SciTech Connect

Centrifugal mirrors use supersonic rotation to provide axial confinement and enhanced stability. Usually the rotation is produced using electrodes, but these electrodes have limited the rotation to the Alfven critical ionization velocity, which is too slow to be useful for fusion. Instead, the rotation could be produced using radio frequency waves. A fixed azimuthal ripple is a simple and efficient wave that could produce rotation by harnessing alpha particle energy. This is an extension of the alpha channeling effect. The alpha particle power and efficiency in a simulated devices is sufficient to produce rotation without external energy input. By eliminating the need for electrodes, this opens new opportunities for centrifugal traps.

Abraham J. Fetterman and Nathaniel J. Fisch

2011-03-28T23:59:59.000Z

236

Planetary-Scale Waves in the Venus Atmosphere  

Science Conference Proceedings (OSTI)

A numerical model of planetary-scale waves in Venus’ atmosphere is used to simulate observed wave-like cloud features such as the dark horizontal Y. The model is based on the linearized primitive equations. Observed variations of static stability ...

Curt Covey; Gerald Schubert

1982-11-01T23:59:59.000Z

237

A Thunderstorm Bow Wave  

Science Conference Proceedings (OSTI)

The thunderstorm solitary gust or bow wave, observed by Doviak and Ge, is examined from the viewpoint of boundary layer wave theory. It is concluded that all its well defined characteristics are consistently modeled as a bow wave of ducted ...

G. Chimonas; Carmen J. Nappo

1987-02-01T23:59:59.000Z

238

The Sandia Wave Reflector  

The Sandia wave reflector is a magnetic conductor for wireless transmissions near 433 MHz. The device reflects perpendicular electromagnetic waves in-phase and suppresses surface waves resulting in improved gain performance and effective operation ...

239

Geostrophic Shock Waves  

Science Conference Proceedings (OSTI)

Organized depth discontinuities involving a balance between steepening and dissipation are usually referred to as shock waves. An analytical “educed gravity” model is used to examine a special kind of shock wave. The wave under study is a depth ...

Doron Nof

1986-05-01T23:59:59.000Z

240

Water waves over strongly undulating bottom  

E-Print Network (OSTI)

Two-dimensional free-surface potential flows of an ideal fluid over a strongly inhomogeneous bottom are investigated with the help of conformal mappings. Weakly-nonlinear and exact nonlinear equations of motion are derived by the variational method for arbitrary seabed shape parameterized by an analytical function. The band structure of linear waves over periodic bottoms is calculated.

Ruban, V P

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "wave velocity variations" 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

Momentum Flux and Flux Divergence of Gravity Waves in Directional Shear Flows over Three-Dimensional Mountains  

Science Conference Proceedings (OSTI)

Linear mountain wave theory is used to derive the general formulas of the gravity wave momentum flux (WMF) and its vertical divergence that develop in directionally sheared flows with constant vertical shear. Height variations of the WMF and its ...

Xin Xu; Yuan Wang; Ming Xue

2012-12-01T23:59:59.000Z

242

TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES IN THE  

Open Energy Info (EERE)

TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES IN THE TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES IN THE COSO GEOTHERMAL FIELD FROM ANALYSES OF SHEAR-WAVE SPLITTING Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES IN THE COSO GEOTHERMAL FIELD FROM ANALYSES OF SHEAR-WAVE SPLITTING Details Activities (1) Areas (1) Regions (0) Abstract: This project aims to improve understanding of the subsurface fracture system in the Coso geothermal field, located in the east central California. We applied shear-wave splitting technique on a set of high quality, locally recorded microearthquake (MEQ) data. Four major fracture directions have been identified from the seismograms recorded by the permanent sixteen-station down-hole array: N10- 20W, NS, N20E, and N40-45E,

243

The jump-off velocity of an impulsively loaded spherical shell  

SciTech Connect

We consider a constant temperature spherical shell of isotropic, homogeneous, linearly elastic material with density {rho} and Lame coefficients {lambda} and {mu}. The inner and outer radii of the shell are r{sub i} and r{sub o}, respectively. We assume that the inside of the shell is a void. On the outside of the shell, we apply a uniform, time-varying pressure p(t). We also assume that the shell is initially at rest. We want to compute the jump-off time and velocity of the pressure wave, which are the first time after t = 0 at which the pressure wave from the outer surface reaches the inner surface. This analysis computes the jump-off velocity and time for both compressible and incompressible materials. This differs substantially from [3], where only incompressible materials are considered. We will consider the behavior of an impulsively loaded, exponentially decaying pressure wave p(t) = P{sub 0{sup e}}{sup -{alpha}t}, where {alpha} {ge} 0. We notice that a constant pressure wave P(t) = P{sub 0} is a special case ({alpha} = 0) of a decaying pressure wave. Both of these boundary conditions are considered in [3].

Chabaud, Brandon M. [Los Alamos National Laboratory; Brock, Jerry S. [Los Alamos National Laboratory

2012-04-13T23:59:59.000Z

244

Tide-Induced Variation of the Dynamics of a Salt Wedge Estuary  

Science Conference Proceedings (OSTI)

The time variations of the salt wedge intrusion in the Fraser estuary, British Columbia, were monitored during a variety of tidal and run-off conditions using instruments and sampling methods that provided high resolution of the velocity and ...

W. Rockwell Geyer; David M. Farmer

1989-08-01T23:59:59.000Z

245

Resonant radiation shed by dispersive shock waves  

E-Print Network (OSTI)

We show that dispersive shock waves resulting from the nonlinearity overbalancing a weak leading-order dispersion can emit resonant radiation owing to higher-order dispersive contributions. We analyze such phenomenon for the defocusing nonlinear Schroedinger equation, giving criteria for calculating the radiated frequency based on the estimate of the shock velocity, revealing also a diversity of possible scenarios depending on the order and magnitude of the dispersive corrections.

Conforti, Matteo; Trillo, Stefano

2013-01-01T23:59:59.000Z

246

Chromospheric Doppler Velocity Oscillations in a Sunspot  

E-Print Network (OSTI)

We analyse the chromospheric Doppler velocity oscillations in a sunspot using the high resolution spectral observations obtained from the Fast Imaging Solar Spectrograph(FISS) of the New Solar Telescope at the Big Bear Solar Observatory. The Doppler velocity maps are constructed from the bisectors of the spectral observations. The time series analysis of Doppler velocity maps show enhanced power in the sunspot umbra at higher frequencies and in the penumbra at lower frequencies. We find that the peak power frequency decreases gradually from the umbra to outward.

Maurya, R A

2013-01-01T23:59:59.000Z

247

Boundary Layer Dynamics in a Simple Model for Convectively Coupled Gravity Waves  

Science Conference Proceedings (OSTI)

A simplified model of intermediate complexity for convectively coupled gravity waves that incorporates the bulk dynamics of the atmospheric boundary layer is developed and analyzed. The model comprises equations for velocity, potential ...

Michael L. Waite; Boualem Khouider

2009-09-01T23:59:59.000Z

248

Spectrally Resolved Energy Dissipation Rate and Momentum Flux of Breaking Waves  

Science Conference Proceedings (OSTI)

Video observations of the ocean surface taken from aboard the Research Platform FLIP reveal the distribution of the along-crest length and propagation velocity of breaking wave crests that generate visible whitecaps. The key quantity assessed is ...

Johannes R. Gemmrich; Michael L. Banner; Chris Garrett

2008-06-01T23:59:59.000Z

249

Vertical Structure of Kelvin Waves in the Indonesian Throughflow Exit Passages  

Science Conference Proceedings (OSTI)

The subsurface structure of intraseasonal Kelvin waves in two Indonesian Throughflow (ITF) exit passages is observed and characterized using velocity and temperature data from the 2004–06 International Nusantara Stratification and Transport (...

Kyla Drushka; Janet Sprintall; Sarah T. Gille; Irsan Brodjonegoro

2010-09-01T23:59:59.000Z

250

Quasi-biennial Oscillation and Its Analog under the Assumption of Wave Self-Acceleration  

Science Conference Proceedings (OSTI)

We have investigated numerically, using a slowly varying model, how the behavior of the quasi-biennial oscillation (QBO) in the equatorial stratosphere and its analog in the laboratory water tank are modified when wave phase velocities are ...

Hiroshi Tanaka; Nobuyuki Yoshizawa

1985-11-01T23:59:59.000Z

251

Analytical Modeling of Wave Generation by the Borehole Orbital Vibrator Source  

E-Print Network (OSTI)

of the source as a function of wave frequency and rockon the source-fluid boundary and the fluid-rock boundary. ToP2 1731 m/s Rock S velocity c S2 Source/borehole parameters

Nakagawa, Seiji; Daley, Thomas M.

2004-01-01T23:59:59.000Z

252

PROPAGATION OF GRAVITY WAVES IN A CONVECTIVE LAYER  

SciTech Connect

We perform numerical simulations of gravity mode propagation in a convective layer to investigate the observed association between small spatial scales and low frequencies in the photospheric velocity fields. According to the linear theory, when the fluid layer is convectively unstable, gravity modes are evanescent waves. However, in simple two-dimensional numerical settings, we find that when the equilibrium structure is modified by coherent large-scale convective motions, the waves injected at the bottom of the layer are no longer evanescent. In this situation, gravity waves can be detected at the surface of the layer. In our simplified model the injected wave's frequency remains unchanged, but its amplitude has a spatial modulation determined by the convective structure. This result may explain some analyses done with the proper orthogonal decomposition method of the solar surface velocity field even though solar convection is far more complex than the convection model considered here.

Onofri, M.; Vecchio, A.; Veltri, P. [Dipartimento di Fisica, Universita della Calabria, via P. Bucci, 87036 Rende (Italy); De Masi, G., E-mail: onofri@fis.unical.it [Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, 35127 Padova (Italy)

2012-02-10T23:59:59.000Z

253

Variation of fundamental constants  

E-Print Network (OSTI)

We present a review of recent works devoted to the variation of the fine structure constant alpha, strong interaction and fundamental masses. There are some hints for the variation in quasar absorption spectra, Big Bang nucleosynthesis, and Oklo natural nuclear reactor data. A very promising method to search for the variation of the fundamental constants consists in comparison of different atomic clocks. Huge enhancement of the variation effects happens in transition between accidentally degenerate atomic and molecular energy levels. A new idea is to build a ``nuclear'' clock based on the ultraviolet transition between very low excited state and ground state in Thorium nucleus. This may allow to improve sensitivity to the variation up to 10 orders of magnitude! Huge enhancement of the variation effects is also possible in cold atomic and molecular collisions near Feschbach resonance.

V. V. Flambaum

2006-08-25T23:59:59.000Z

254

Assimilation of Radar Radial Velocity Data with the WRF Hybrid Ensemble–3DVAR System for the Prediction of Hurricane Ike (2008)  

Science Conference Proceedings (OSTI)

An enhanced version of the hybrid ensemble–three-dimensional variational data assimilation (3DVAR) system for the Weather Research and Forecasting Model (WRF) is applied to the assimilation of radial velocity (Vr) data from two coastal Weather ...

Yongzuo Li; Xuguang Wang; Ming Xue

2012-11-01T23:59:59.000Z

255

Fundamental Guided Wave Metrology  

Science Conference Proceedings (OSTI)

Fundamental Guided Wave Metrology. Summary: ... The program is focused on fundamental measurement research for microwave parameters. ...

2010-10-05T23:59:59.000Z

256

Nonlinear fan instability of electromagnetic waves  

Science Conference Proceedings (OSTI)

This paper studies the linear and nonlinear stages of the fan instability, considering electromagnetic waves of the whistler frequency range interacting resonantly with energetic electron fluxes in magnetized plasmas. The main attention is paid to determine the wave-particle interaction processes that can lead to the excitation of intense electromagnetic waves by nonequilibrium particle distributions involving suprathermal tails, and to explain under what conditions and through what mechanisms they can occur, develop, and saturate. This paper presents and discusses two main processes: (i) the linear fan instability and (ii) the nonlinear process of dynamical resonance merging, which can significantly amplify the energy carried by linearly destabilized waves after they saturate due to particle trapping. This study consists of (i) determining analytically and numerically, for parameters typical of space and laboratory plasmas, the linear growth rates of whistlers excited by suprathermal particle fluxes through the fan instability, as well as the corresponding thresholds and the physical conditions at which the instability can appear, (ii) building a theoretical self-consistent 3D model and a related numerical code for describing the nonlinear evolution of the wave-particle system, and (iii) performing numerical simulations to reveal and characterize the nonlinear amplification process at work, its conditions of development, and its consequences, notably in terms of electromagnetic wave radiation. The simulations show that when the waves have reached sufficient energy levels owing to the linear fan instability, they saturate by trapping particles and due to the complex dynamics of these particles in the electromagnetic fields, the resonant velocities' domains of the waves overlap and merge, meanwhile a strong increase of the wave energy occurs.

Krafft, C. [Laboratoire de Physique des Plasmas, Ecole Polytechnique, 91128 Palaiseau Cedex (France) and University Paris Sud, 91405 Orsay Cedex (France); Volokitin, A. [Space Research Institute (IKI), 117997, 84/32 Profsoyuznaya Str., Moscow (Russian Federation)

2010-10-15T23:59:59.000Z

257

Determination of applied stresses in rails using the acoustoelastic effect of ultrasonic waves  

E-Print Network (OSTI)

This research develops a procedure to determine the applied stresses in rails using the acoustoelastic effect of ultrasonic waves. Acoustoelasticity is defined as the stress dependency of ultrasonic wave speed or wave polarization. Analytical models are developed that predict the acoustoelastic effect for longitudinal waves, shear waves, Lamb waves, and Rayleigh waves. Using a programming tool, a numerical simulation of the models is generated to obtain the stress dependent curves of wave velocity and polarization of the various ultrasonic waves propagating in rail steel. A comparison of the sensitivity of the acoustoelastic effect is made to determine the feasibility of ultrasonic waves for further study. Rayleigh waves are found to be most sensitive to stress change. Rayleigh waves are generated using ultrasonic transducer and detected using a laser Doppler vibrometer (LDV). The LDV measures the in-plane and out-of-plane velocities. Polarization is defined as the ratio of in-plane and out-of-plane displacements. Initially, polarization is determined for the specimen in unstressed condition. Thereafter, the rail specimen is stressed in a compression testing machine, the experiment repeated, and the polarization determined. Thus, Rayleigh wave polarization is obtained as a function of applied stress. Finally, the change in polarization obtained experimentally is compared with the analytical model.

Gokhale, Shailesh Ashok

2007-12-01T23:59:59.000Z

258

Stochastic variational inference  

Science Conference Proceedings (OSTI)

We develop stochastic variational inference, a scalable algorithm for approximating posterior distributions. We develop this technique for a large class of probabilistic models and we demonstrate it with two probabilistic topic models, latent Dirichlet ... Keywords: Bayesian inference, Bayesian nonparametrics, stochastic optimization, topic models, variational inference

Matthew D. Hoffman, David M. Blei, Chong Wang, John Paisley

2013-01-01T23:59:59.000Z

259

Mesoscale Thermohaline, Sound Velocity and Baroclinic Flow Structure of the Pacific Subtropical Front During the Winter of 1980  

Science Conference Proceedings (OSTI)

The three-dimensional thermohaline. sound velocity and baroclinic flow structure of the. pacific sub-tropical front during January and February 1990 are discussed. The front is meander-like, with a wavelength of 180 km, a wave amplitude of 55 km, ...

Gunnar I. Roden

1981-05-01T23:59:59.000Z

260

Molecular Dynamics Simulation of Smaller Granular Particles Deposition on a Larger One Due to Velocity Sequence Dependent Electrical Charge Distribution  

E-Print Network (OSTI)

Deposition of smaller granular particles on a larger nucleus particle has been simulated in two-dimension using molecular dynamics method. Variation of sequences of velocity of deposited particles is conducted and reported in this work. The sequences obey a normal distribution function of velocity with the same parameters. It has been observed that for velocity in range of 0 to 0.02 the densest deposited site (15-17 % number of grains) is located at about angle {\\pi}/4 where location of injection point is {\\pi}/4. And the less dense is about {\\pi}/4 + {\\pi}/2. Different sequences give similar result.

Euis Sustini; Siti Nurul Khotimah; Ferry Iskandar; Sparisoma Viridi

2011-07-11T23:59:59.000Z

Note: This page contains sample records for the topic "wave velocity variations" 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

Watching Gravitational Waves  

E-Print Network (OSTI)

In the vicinity of merging neutron strar binaries or supernova remnants, gravitational waves can interact with the prevailing strong magnetic fields. The resulting partial conversion of gravitational waves into electromagnetic (radio) waves might prove to be an indirect way of detecting gravitational waves from such sources. Another interesting interaction considered in this article is the excitation of magnetosonic plasma waves by a gravitational wave passing through the surrounding plasma. The transfer of gravitational wave energy into the plasma might help to fuel the `fireball' of electromagnetic radiation observed in gamma ray bursts. In the last section of the article, a dispersion relation is derived for such magnetosonic plasma waves driven by a gravitational wave.

Joachim Moortgat

2001-04-02T23:59:59.000Z

262

Gravity waves from vortex dipoles and jets  

E-Print Network (OSTI)

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

Wang, Shuguang

2008-08-01T23:59:59.000Z

263

Estimating Spatial Velocity Statistics with Coherent Doppler Lidar  

Science Conference Proceedings (OSTI)

The spatial statistics of a simulated turbulent velocity field are estimated using radial velocity estimates from simulated coherent Doppler lidar data. The structure functions from the radial velocity estimates are processed to estimate the ...

Rod Frehlich; Larry Cornman

2002-03-01T23:59:59.000Z

264

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

265

Impact of Hight Velocity Cold Spray Particles  

SciTech Connect

This paper presents experimental data and an computational model of the cold spray solid particle impact process. Copper particles impacting onto a polished stainless steel substrate are examined. The high velocity impact causes significant plastic deformation of both the particle and the sub- strate, but no melting is observed. The plastic deformation exposes clean surfaces that, under the high impact pressures, result in significant bond strengths between the particle and substrate. Experimental measurements of the splat and crater sizes compare well with the numerical calculations. It is shown that the crater depth is significant and increases with impact velocity. However, the splat diameter is much less sensitive to the impact velocity. It is also shown that the geometric lengths of the splat and crater scale linearly with the diameter of the impacting particle. It is hoped that the results presented will allow better understanding of the bonding process during cold spray.

Dykhuizen, R.C.; Gilmore, D.L.; Jiang, X.; Neiser, R.A.; Sampath, S.; Smith, M.F.

1998-12-01T23:59:59.000Z

266

Visibility graph analysis of solar wind velocity  

E-Print Network (OSTI)

We analyze in situ measurements of solar wind velocity obtained by Advanced Composition Explorer (ACE) spacecraft and Helios spacecraft during the years 1998-2012 and 1975-1983 respectively. The data belong to mainly solar cycle 23 (1996-2008) and solar cycle 21 (1976-1986) respectively. We use Directed Horizontal Visibility graph (DHVg) algorithm and estimate a graph functional, namely, the degree distance (D) as the Kullback-Leibler divergence (KLD) argument to understand time irreversibility of solar wind time series. We estimate this degree distance irreversibility parameter for these time series at different phases of solar activity cycle. Irreversibility parameter is first established for known dynamical data and then applied for solar wind velocity time series. It is observed that irreversibility in solar wind velocity fluctuations show similar behaviour at 0.3 AU (Helios data) and 1 AU (ACE data). Moreover it changes over the different phases of solar activity cycle.

Suyal, Vinita; Singh, Harinder P

2013-01-01T23:59:59.000Z

267

Seismic wave propagation in cracked porous media Tim Pointer,1,  

E-Print Network (OSTI)

, Pi plays an important role. There is much higher attenuation and dispersion for gas (which is more, as for PARTIAL ALIGN, there is no velocity dispersion; there is also increased P and SV attenuation as the gas in there is high attenuation and dispersion of seismic waves. Fluid £ow may be on either a wavelength scale

Edinburgh, University of

268

Mesoscale Waves as a Probe of Jupiter's Deep Atmosphere  

Science Conference Proceedings (OSTI)

Search of the Voyager images of Jupiter reveals a class of mesoscale waves occurring near the extrema of the zonal velocity profile between latitudes 30°S and 30°N. The average horizontal wavelength is 300 km, compared to an atmospheric scale ...

F. M. Flasar; P. J. Gierasch

1986-11-01T23:59:59.000Z

269

Near-Surface Turbulence in the Presence of Breaking Waves  

Science Conference Proceedings (OSTI)

Observations with a three-axis pulse-to-pulse coherent acoustic Doppler profiler and acoustic resonators reveal the turbulence and bubble field beneath breaking waves in the open ocean at wind speeds up to 14 m s?1. About 55%–80% of velocity ...

Johannes R. Gemmrich; David M. Farmer

2004-05-01T23:59:59.000Z

270

The Free Kelvin Wave with Lateral and Vertical Viscosity  

Science Conference Proceedings (OSTI)

Free Kelvin wave solutions of the linear shallow-water equations are described, for an f-plane. Lateral and vertical viscous effects are represented by terms ?2u and du, respectively, where (u,v) is the (onshore, longshore) velocity. Both no-...

Michael K. Davey; William W. Hsieh; Roxana C. Wajsowicz

1983-12-01T23:59:59.000Z

271

Sea-Surface Drift Currents Induced by Wind and Waves  

Science Conference Proceedings (OSTI)

Wind-induced shell currents and wave-induced mass transports at various fetches of both clean and slick sea surfaces are separately estimated. At the clean surface, the ratio between wind-induced current and wind velocity decreases, while the ...

Jin Wu

1983-08-01T23:59:59.000Z

272

Observations of Vortex Rossby Waves Associated with a Mesoscale Cyclone  

Science Conference Proceedings (OSTI)

Short-wavelength (L 100 km) Rossby waves with an eastward zonal phase velocity were observed by high-frequency radio Doppler current meters and moored ADCPs west of Oahu, Hawaii, during spring 2003. They had Rossby numbers Ro = |?/f| = O(1), ...

Cédric P. Chavanne; Pierre Flament; Douglas S. Luther; Klaus-Werner Gurgel

2010-10-01T23:59:59.000Z

273

Manifold constrained variational mixtures  

Science Conference Proceedings (OSTI)

In many data mining applications, the data manifold is of lower dimension than the dimension of the input space. In this paper, it is proposed to take advantage of this additional information in the frame of variational mixtures. The responsibilities ...

Cédric Archambeau; Michel Verleysen

2005-09-01T23:59:59.000Z

274

Application of optical remote sensing to the measurment of wave surface kinematics  

E-Print Network (OSTI)

This research study focused on the development and application of a laboratory instrument utilizing real-time video in conjunction with image processing techniques to accurately measure 3-dimensional wave surface kinematics. This thesis presents the design and results of the instrument in its initial, 2-dimensional measurement, stage of development. The objective was to design a functioning laboratory instrument and use it to measure horizontal surface velocities on a series of waves. These results are compared to those of existing theoretical methods to determine both the accuracy and feasibility of the instrument. Measurement of horizontal surface velocities are conducted on a series of regular and irregular waves. Results of the regular wave measurements are compared to well established higher order wave theory to quantify the accuracy of the laboratory instrument. The results of the irregular wave measurements are compared to predicted velocity time series acquired from the Hybrid Wave Model, Wheeler Stretching and Linear Extrapolation. Adjustments are then made to the measured velocity time series to represent any drift currents that might be present in the flume that theory can not predict. Comparison of the adjusted time series are then made to those predicted by the three theoretical methods. Maximum and Minimum measured velocities for each wave set are also compared to predicted values. Comparisons between measured and theoretical values show that the instrument and the theoretical models are in agreement and thus the laboratory instrument is a capable means of accurately measuring wave surface kinematics. Results also show that considering the agreement between theory and measured values, when taking into account the excessive amount time required to produce velocities from the video images, the instrument, in its current form, is not a practical method for surface kinematic measurements. There is, however, enough evidence to show that expanding the instrument to include 3-dimensional measurement capabilities would produce a valuable laboratory tool.

Riedl, Stephen James

1994-01-01T23:59:59.000Z

275

Radiation of Electron in the Field of Plane Light Wave  

SciTech Connect

Results of integration of a Lorentz equation for a relativistic electron moving in the field of running, plane, linear polarized electromagnetic wave are presented in the paper. It is shown that electron velocities in the field of the wave are almost periodic functions of time. For calculations of angular spectrum of electron radiation intensity expansion of the electromagnetic field in a wave zone into generalized Fourier series was used. Expressions for the radiation intensity spectrum are presented in the paper. Derived results are illustrated for electron and laser beam parameters of NSC KIPT X-ray generator NESTOR. It is shown that for low intensity of the interacting electromagnetic wave the results of energy and angular spectrum calculations in the frame of classical electrodynamics completely coincide with calculation results produced using quantum electrodynamics. Simultaneously, derived expressions give possibilities to investigate dependence of energy and angular Compton radiation spectrum on phase of interaction and the interacting wave intensity.

Zelinsky, A.; Drebot, I.V.; Grigorev, Yu.N.; Zvonareva, O.D.; /Kharkov, KIPT; Tatchyn, R.; /SLAC

2006-02-24T23:59:59.000Z

276

Effect of the Darrieus-Landau instability on turbulent flame velocity  

E-Print Network (OSTI)

Propagation of turbulent premixed flames influenced by the intrinsic hydrodynamic flame instability (the Darrieus-Landau instability) is considered in a two-dimensional case using the model nonlinear equation proposed recently. The nonlinear equation takes into account both influence of external turbulence and intrinsic properties of a flame front, such as small but finite flame thickness and realistically large density variations across the flame front. Dependence of the flame velocity on the turbulent length scale, on the turbulent intensity and on the density variations is investigated in the case of weak non-linearity and weak external turbulence. It is shown that the Darrieus-Landau instability influences the flamelet velocity considerably. The obtained results are in agreement with experimental data on turbulent burning of moderate values of the Reynolds number.

Maxim Zaytsev; Vitaliy Bychkov

2012-11-26T23:59:59.000Z

277

In-Situ Continuous Detonation Velocity Measurements Using Fiber-optic Bragg Grating Sensors  

Science Conference Proceedings (OSTI)

In order to fully calibrate hydrocodes and dynamic chemistry burn models, initiation and detonation research requires continuous measurement of low order detonation velocities as the detonation runs up to full order detonation for a given density and initiation pressure pulse. A novel detector of detonation velocity is presented using a 125 micron diameter optical fiber with an integral chirped fiber Bragg grating as an intrinsic sensor. This fiber is embedded in the explosive under study and interrogated during detonation as the fiber Bragg grating scatters light back along the fiber to a photodiode, producing a return signal dependant on the convolution integral of the grating reflection bandpass, the ASE intensity profile and the photodetector response curve. Detonation velocity is measured as the decrease in reflected light exiting the fiber as the grating is consumed when the detonation reaction zone proceeds along the fiber sensor axis. This small fiber probe causes minimal perturbation to the detonation wave and can measure detonation velocities along path lengths tens of millimeters long. Experimental details of the associated equipment and preliminary data in the form of continuous detonation velocity records within nitromethane and PBX-9502 are presented.

Benterou, J; Udd, E; Wilkins, P; Roeske, F; Roos, E; Jackson, D

2007-07-25T23:59:59.000Z

278

Gravity Waves from Thunderstorms  

Science Conference Proceedings (OSTI)

Gravity waves generated by severe thunderstorms in the eastern Ohio-Pennsylvania area were recorded by an array of microbarovariographs at Palisades, New York and by standard microbarographs across northeastern United States. The waves were ...

Nambath K. Balachandran

1980-06-01T23:59:59.000Z

279

Vehicle Velocity Estimation Based on RSS Measurements  

Science Conference Proceedings (OSTI)

This paper presents a technique which is based on pattern recognition techniques, in order to estimate Mobile Terminal (MT) velocity. The proposed technique applies on received signal strength (RSS) measurements and more precisely on information extracted ... Keywords: HIDden Markov Model, WCDMA, clustering, location based services, pattern recognition, propagation modeling, traffic information

Theodore S. Stamoulakatos; Antonis S. Markopoulos; Miltiadis E. Anagnostou; Michalis E. Theologou

2007-03-01T23:59:59.000Z

280

Aggregate Terminal Velocity/Temperature Relations  

Science Conference Proceedings (OSTI)

Terminal velocities of snow aggregates in storms along the Front Range in eastern Colorado are examined with a ground-based two-dimensional video disdrometer. Power-law relationships for particles having equivalent volume diameters of 0.5–20 mm ...

Edward A. Brandes; Kyoko Ikeda; Gregory Thompson; Michael Schönhuber

2008-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "wave velocity variations" 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

A study of swirl and axial velocity profile effects on orifice flowmeters  

E-Print Network (OSTI)

The objective of this study is to measure the response of the orifice meter to known upstream flow field disturbances generated by a concentric tube flow conditioner and a vane-type swirl generator. These disturbances are characterized by flan measuring the axial and tangential velocity profiles at the upstream tap with no orifice plate present. Two different flow rates are examined which correspond to Reynolds numbers of 91,100 and 120,000 in a 50.8 mm diameter pipe. Eight orifice plates with [ ] ratios of 0.43, 0.45, 0.484, 0.55, 0.6, 0.65, 0.7 and 0.726 are studied at both flow rates. The response of each orifice meter to the disturbance is measured by determining the axial pressure distribution near the orifice plate, and by determining the discharge coefficient. The axial momentum distribution is quantified by calculating the second order moment of axial momentum (91 2[U]) from the velocity profile data. Swirl is quantified by determining the centripetal acceleration flux of the flow, also from the velocity profile data. Surface fits indicating the variation of discharge coefficient as a function of P ratio and 9i2[U] or swirl number are developed. These are useful in evaluating variations in the discharge coefficient for flows where the inlet velocity profile has been measured.

Hauglie, Jayden Edward

1994-01-01T23:59:59.000Z

282

A global 3D P-velocity model of the Earth's crust and mantle for improved event location : SALSA3D.  

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 version 1.5, 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 {approx}50%. 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. We compare the travel-time prediction and location capabilities of SALSA3D to standard 1D models via location tests on a global event set with GT of 5 km or better. These events generally possess hundreds of Pn and P picks from which we generate different realizations of station distributions, yielding a range of azimuthal coverage and ratios of teleseismic to regional arrivals, with which we test the robustness and quality of relocation. The SALSA3D model reduces mislocation over standard 1D ak135 regardless of Pn to P ratio, with the improvement being most pronounced at higher azimuthal gaps.

Young, Christopher John; Steck, Lee K. (Los Alamos National Laboratory); Phillips, William Scott (Los Alamos National Laboratory); Ballard, Sanford; Chang, Marcus C.; Rowe, Charlotte A. (Los Alamos National Laboratory); Encarnacao, Andre Villanova; Begnaud, Michael A. (Los Alamos National Laboratory); Hipp, James Richard

2010-07-01T23:59:59.000Z

283

Horizon effects with surface waves on moving water  

E-Print Network (OSTI)

Surface waves on a stationary flow of water are considered, in a linear model that includes the surface tension of the fluid. The resulting gravity-capillary waves experience a rich array of horizon effects when propagating against the flow. In some cases three horizons (points where the group velocity of the wave reverses) exist for waves with a single laboratory frequency. Some of these effects are familiar in fluid mechanics under the name of wave blocking, but other aspects, in particular waves with negative co-moving frequency and the Hawking effect, were overlooked until surface waves were investigated as examples of analogue gravity [Sch\\"utzhold R and Unruh W G 2002 Phys. Rev. D 66 044019]. A comprehensive presentation of the various horizon effects for gravity-capillary waves is given, with emphasis on the deep water/short wavelength case kh>>1 where many analytical results can be derived. A similarity of the state space of the waves to that of a thermodynamic system is pointed out.

Germain Rousseaux; Philippe Maissa; Christian Mathis; Pierre Coullet; Thomas G. Philbin; Ulf Leonhardt

2010-04-30T23:59:59.000Z

284

The Effect of Wave Breaking on the Wave Energy Spectrum  

Science Conference Proceedings (OSTI)

The effect of wave breaking on the wave energy spectral shape is examined. The Stokes wave-breaking criterion is first extended to random waves and a breaking wave model is established in which the elevation of breaking waves is expressed in ...

C. C. Tung; N. E. Huang

1987-08-01T23:59:59.000Z

285

Solar cycle variations of large scale flows in the Sun  

E-Print Network (OSTI)

Using data from the Michelson Doppler Imager (MDI) instrument on board the Solar and Heliospheric Observatory (SOHO), we study the large-scale velocity fields in the outer part of the solar convection zone using the ring diagram technique. We use observations from four different times to study possible temporal variations in flow velocity. We find definite changes in both the zonal and meridional components of the flows. The amplitude of the zonal flow appears to increase with solar activity and the flow pattern also shifts towards lower latitude with time.

Sarbani Basu; H. M. Antia

2000-01-17T23:59:59.000Z

286

DIRECT IMAGING OF QUASI-PERIODIC FAST PROPAGATING WAVES OF {approx}2000 km s{sup -1} IN THE LOW SOLAR CORONA BY THE SOLAR DYNAMICS OBSERVATORY ATMOSPHERIC IMAGING ASSEMBLY  

Science Conference Proceedings (OSTI)

Quasi-periodic propagating fast mode magnetosonic waves in the solar corona were difficult to observe in the past due to relatively low instrument cadences. We report here evidence of such waves directly imaged in EUV by the new Atmospheric Imaging Assembly instrument on board the Solar Dynamics Observatory. In the 2010 August 1 C3.2 flare/coronal mass ejection event, we find arc-shaped wave trains of 1%-5% intensity variations (lifetime {approx}200 s) that emanate near the flare kernel and propagate outward up to {approx}400 Mm along a funnel of coronal loops. Sinusoidal fits to a typical wave train indicate a phase velocity of 2200 {+-} 130 km s{sup -1}. Similar waves propagating in opposite directions are observed in closed loops between two flare ribbons. In the k-{omega} diagram of the Fourier wave power, we find a bright ridge that represents the dispersion relation and can be well fitted with a straight line passing through the origin. This k-{omega} ridge shows a broad frequency distribution with power peaks at 5.5, 14.5, and 25.1 mHz. The strongest signal at 5.5 mHz (period 181 s) temporally coincides with quasi-periodic pulsations of the flare, suggesting a common origin. The instantaneous wave energy flux of (0.1-2.6) x 10{sup 7} erg cm{sup -2} s{sup -1} estimated at the coronal base is comparable to the steady-state heating requirement of active region loops.

Liu Wei; Title, Alan M.; Schrijver, Carolus J.; Aschwanden, Markus J.; De Pontieu, Bart; Tarbell, Theodore D. [Lockheed Martin Solar and Astrophysics Laboratory, Building 252, 3251 Hanover Street, Palo Alto, CA 94304 (United States); Zhao Junwei [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States); Ofman, Leon [Catholic University of America and NASA Goddard Space Flight Center, Code 671, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States)

2011-07-20T23:59:59.000Z

287

Calculating Reynolds Stresses from ADCP Measurements in the Presence of Surface Gravity Waves Using the Cospectra-Fit Method  

Science Conference Proceedings (OSTI)

Recently, the velocity observations of acoustic Doppler current profilers (ADCPs) have been successfully used to estimate turbulent Reynolds stresses in estuaries and tidal channels. However, the presence of surface gravity waves can ...

Anthony R. Kirincich; Steven J. Lentz; Gregory P. Gerbi

2010-05-01T23:59:59.000Z

288

Gravity Wave – Fine Structure Interactions, Part 1: Influences of Fine-Structure Form and Orientation on Flow Evolution and Instability  

Science Conference Proceedings (OSTI)

Four idealized direct numerical simulations are performed to examine the dynamics arising from the superposition of a monochromatic gravity wave and sinusoidal linear and rotary fine structure in the velocity field. These simulations are motivated ...

David C. Fritts; Ling Wang; Joseph A. Werne

289

Sensitivity of Internal Gravity Waves Solutions to the Time Step of a Semi-Implicit Semi-Lagrangian Nonhydrostatic Model  

Science Conference Proceedings (OSTI)

The combination of semi-implicit and semi-Lagrangian marching algorithms leads to stable integration of the meteorological equations with long time steps even for large advecting velocities and fast-moving free waves. In recent years, however, ...

Philippe Héreil; René Laprise

1996-05-01T23:59:59.000Z

290

Statistical Parameters of the Air Turbulent Boundary Layer over Steep Water Waves Measured by the PIV Technique  

Science Conference Proceedings (OSTI)

A turbulent airflow with a centerline velocity of 4 m s?1 above 2.5-Hz mechanically generated gravity waves of different amplitudes has been studied in experiments using the particle image velocimetry (PIV) technique. Direct measurements of the ...

Yu. Troitskaya; D. Sergeev; O. Ermakova; G. Balandina

2011-08-01T23:59:59.000Z

291

Magnetoacoustic shock waves in dissipative degenerate plasmas  

SciTech Connect

Quantum magnetoacoustic shock waves are studied in homogenous, magnetized, dissipative dense electron-ion plasma by using two fluid quantum magneto-hydrodynamic (QMHD) model. The weak dissipation effects in the system are taken into account through kinematic viscosity of the ions. The reductive perturbation method is employed to derive Korteweg-de Vries Burgers (KdVB) equation for magnetoacoustic wave propagating in the perpendicular direction to the external magnetic field in dense plasmas. The strength of magnetoacoustic shock is investigated with the variations in plasma density, magnetic field intensity, and ion kinematic viscosity of dense plasma system. The necessary condition for the existence of monotonic and oscillatory shock waves is also discussed. The numerical results are presented for illustration by using the data of astrophysical dense plasma situations such as neutron stars exist in the literature.

Hussain, S.; Mahmood, S. [Theoretical Plasma Physics Division (TPPD), PINSTECH, P.O. Nilore Islamabad 44000 (Pakistan) and Department of Physics and Applied Mathematics (DPAM) PIEAS, P.O. Nilore Islamabad 44000 (Pakistan)

2011-11-15T23:59:59.000Z

292

Potential Vorticity and Layer Thickness Variations in the Flow around Jupiter's Great Red Spot and White Oval BC  

Science Conference Proceedings (OSTI)

Layer thickness variations in Jupiter's atmosphere are investigated by treating potential vorticity as a conserved tracer. Starting with the horizontal velocity field measured from Voyager images, fluid trajectories around the Great Red Spot (GRS)...

Timothy E. Dowling; Andrew P. Ingersoll

1988-04-01T23:59:59.000Z

293

Variational Pseudo-Multiple-Doppler Wind Retrieval in the Vertical Plane for Ground-Based Mobile Radar Data  

Science Conference Proceedings (OSTI)

A variational procedure is developed that utilizes mobile ground-based range–height indicator (RHI) Doppler radar velocity data for the synthesis of two-dimensional, RHI plane wind vectors. The radial component winds are obtained with the radar ...

Christopher C. Weiss; Howard B. Bluestein; Robert Conzemius; Evgeni Fedorovich

2007-07-01T23:59:59.000Z

294

Vorticity and Divergence of Surface Velocities Near Shore  

Science Conference Proceedings (OSTI)

The nearshore environment is complex, with many competing dynamical elements. Surface waves and edge waves (a form of surface wave trapped to the shore) can generally be separated from other forms of motion because of their fast propagation ...

Jerome A. Smith

2008-07-01T23:59:59.000Z

295

On the theory of turbulent flame velocity  

E-Print Network (OSTI)

The renormalization ideas of self-similar dynamics of a strongly turbulent flame front are applied to the case of a flame with realistically large thermal expansion of the burning matter. In that case a flame front is corrugated both by external turbulence and the intrinsic flame instability. The analytical formulas for the velocity of flame propagation are obtained. It is demonstrated that the flame instability is of principal importance when the integral turbulent length scale is much larger than the cut off wavelength of the instability. The developed theory is used to analyse recent experiments on turbulent flames propagating in tubes. It is demonstrated that most of the flame velocity increase measured experimentally is provided by the large scale effects like the flame instability, and not by the small-scale external turbulence.

Vitaly Bychkov; Vyacheslav Akkerman; Arkady Petchenko

2012-10-19T23:59:59.000Z

296

Analysis of WACSIS data using a directional hybrid wave model  

E-Print Network (OSTI)

This study focuses on the analysis of measured directional seas using a nonlinear model, named Directional Hybrid Wave Model (DHWM). The model has the capability of decomposing the directional wave field into its free wave components with different frequency, amplitude, direction and initial phase based on three or more time series of measured wave properties. With the information of free waves, the DHWM can predict wave properties accurately up to the second order in wave steepness. In this study, the DHWM is applied to the analyses of the data of Wave Crest Sensor Inter-comparison Study (WACSIS). The consistency between the measurements collected by different sensors in the WACSIS project was examined to ensure the data quality. The wave characteristics at the locations of selected sensors were predicted in time domain and were compared with those recorded at the same location. The degree of agreement between the predictions and the related measurements is an indicator of the consistency among different sensors. To analyze the directional seas in the presence of strong current, the original DHWM was extended to consider the Doppler effects of steady and uniform currents on the directional wave field. The advantage of extended DHWM originates from the use of the intrinsic frequency instead of the apparent frequency to determine the corresponding wavenumber and transfer functions relating wave pressure and velocities to elevation. Furthermore, a new approach is proposed to render the accurate and consistent estimates of the energy spreading parameter and mean wave direction of directional seas based on a cosine-2s model. In this approach, a Maximum Likelihood Method (MLM) is employed. Because it is more tolerant of errors in the estimated cross spectrum than a Directional Fourier Transfer (DFT) used in the conventional approach, the proposed approach is able to estimate the directional spreading parameters more accurately and consistently, which is confirmed by applying the proposed and conventional approach, respectively, to the time series generated by numerical simulation and recorded during the WACSIS project.

Zhang, Shaosong

2005-12-01T23:59:59.000Z

297

Beam loading voltage profile of an accelerating section with a linearly varying group velocity  

E-Print Network (OSTI)

The CLIC Tapered Damped accelerating Structure (TDS) has a 5.4% detuning of the lowest dipole mode. The geometrical variations that produce this detuning range also fix the fundamental mode's group velocity variation - very nearly linear with 0.108c (c is the speed of light) at the structure input to 0.054c at the output. In addition R'/Q also varies approximately linearly, from 22.3 kW/m at the input to 30 kW/m at the output. These variations result in a structure that is neither constant impedance nor constant gradient so the widely used relationships between structure length, input and average accelerating gradient are not applicable. In order to simplify the process of optimizing accelerator parameters an analytic expression for the voltage profile in a structure with a linearly varying group velocity has been derived. A more accurate numerical solution that includes the variation in R'/Q is also presented.

Wuensch, Walter

1999-01-01T23:59:59.000Z

298

Cycloidal Wave Energy Converter  

SciTech Connect

This program allowed further advancing the development of a novel type of wave energy converter, a Cycloidal Wave Energy Converter or CycWEC. A CycWEC consists of one or more hydrofoils rotating around a central shaft, and operates fully submerged beneath the water surface. It operates under feedback control sensing the incoming waves, and converts wave power to shaft power directly without any intermediate power take off system. Previous research consisting of numerical simulations and two dimensional small 1:300 scale wave flume experiments had indicated wave cancellation efficiencies beyond 95%. The present work was centered on construction and testing of a 1:10 scale model and conducting two testing campaigns in a three dimensional wave basin. These experiments allowed for the first time for direct measurement of electrical power generated as well as the interaction of the CycWEC in a three dimensional environment. The Atargis team successfully conducted two testing campaigns at the Texas A&M Offshore Technology Research Center and was able to demonstrate electricity generation. In addition, three dimensional wave diffraction results show the ability to achieve wave focusing, thus increasing the amount of wave power that can be extracted beyond what was expected from earlier two dimensional investigations. Numerical results showed wave cancellation efficiencies for irregular waves to be on par with results for regular waves over a wide range of wave lengths. Using the results from previous simulations and experiments a full scale prototype was designed and its performance in a North Atlantic wave climate of average 30kW/m of wave crest was estimated. A full scale WEC with a blade span of 150m will deliver a design power of 5MW at an estimated levelized cost of energy (LCOE) in the range of 10-17 US cents per kWh. Based on the new results achieved in the 1:10 scale experiments these estimates appear conservative and the likely performance at full scale will exceed this initial performance estimates. In advancing the Technology Readiness Level (TRL) of this type of wave energy converter from 3 to 4, we find the CycWEC to exceed our initial estimates in terms of hydrodynamic performance. Once fully developed and optimized, it has the potential to not just outperform all other WEC technologies, but to also deliver power at a lower LCOE than competing conventional renewables like wind and solar. Given the large wave power resource both domestically and internationally, this technology has the potential to lead to a large improvement in our ability to produce clean electricity at affordable cost.

Stefan G. Siegel, Ph.D.

2012-11-30T23:59:59.000Z

299

Material Property Estimation for Direct Detections of DNAPL using Integrated Ground-Penetrating Radar Velocity, Imaging and Attribute Analysis  

DOE Green Energy (OSTI)

The focus of our work is direct detection of DNAPLs, specifically chlorinated solvents, via material property estimation from surface ground-penetrating radar (GPR) data. We combine sophisticated GPR processing methodology with quantitative attribute analysis and material property estimation to determine the location and extent of residual and/or pooled DNAPL in both the vadose and saturated zones. An important byproduct of our research is state-of-the-art imaging which allows us to pinpoint attribute anomalies, characterize stratigraphy, identify fracture zones, and locate buried objects. Implementation and verification of these methodologies will be a significant advance in GPR research and in meeting DOE's need for reliable in-situ characterization of DNAPL contamination. Chlorinated solvents have much lower electric permittivity and conductivity than water. An electrical property contrast is induced when solvents displace water in the sediment column resulting in an anomalous GPR signature. To directly identify zones of DNAPL contamination, we focus on three aspects of reflected wave behavior--propagation velocity, frequency dependent attenuation, and amplitude variation with offset (AVO). Velocity analysis provides a direct estimate of electric permittivity, attenuation analysis provides a measure of conductivity, and AVO behavior is used to estimate the permittivity ratio at a reflecting boundary. Areas of anomalously low electric permittivity and conductivity are identified as potential DNAPL rich zones. Preliminary work illustrated significant potential for quantitative direct detection methodologies in identifying shallow DNAPL source zones. It is now necessary to verify these methodologies in a field setting. To this end, the project is field oriented and has three primary objectives: (1) Develop a suite of methodologies for direct detection of DNAPLs from surface GPR data (2) Controlled field verification at well characterized, contaminated sites (3) Exploratory contaminant detection in a field setting to be verified through direct sampling Field experiments are being conducted at the Savannah River and Hanford sites, at five DOD sites (Dover AFB, DE; McClellan AFB, CA; Port Hueneme, CA; Wurtsmith AFB, MI; Hill AFB, UT), at a former refinery site near Cincinnati, Ohio, and at a creosote wood preserving site in Fayetville, NC.

Bradford, John; Smithson, Scott B.; Holbrook, W. Stephen

2004-06-14T23:59:59.000Z

300

Comparison of P-wave and S-wave data processed by DIP moveout  

E-Print Network (OSTI)

One of the major goals of seismic data processing is to produce an accurate image of the subsurface of the earth. Unfortunately, when dipping events or diffractions are present, or when velocities vary laterally, the normal-moveout (NMO) correction applied in common midpoint (CMP) stacking fails to convert even primary events on non-zero offset traces to true zero offset. Dip moveout (DMO) is a process that converts non-zerooffset data to true zero offset after NMO has been applied. Direct comparison of compressional (P) and shear (S) wave data in a fractured reservoir can show whether amplitude anomalies on the P-wave section are associated with the presence of gas or change of lithology. The P-wave and S-wave data selected for this study were shot in Burleson County, Texas. After processing, the P-wave and S-wave sections were interpreted. No gas-related DHf (direct hydrocarbon indicator) was seen in both sections. Comparison of both sections before and after DMO shows that DMO has helped imaging the fractures in the Austin Chalk and provided a clear image of the subsurface after migrating the DMO data. Major reflectors such as the Pecan Gap, "Top-of-the-Austin-Chalk", "Bottom-of-theAustin-Chalk", and Buda correlate well with seismic events on the synthetic seismogram which was generated from the sonic log of the Lancier Brinckman #1 well. The difference in depth between the sonic log and the P-wave seismic section is small. The sonic log depths are deeper than the P-wave seismic section depths. The top and bottom of the Austin Chalk reflectors on both sections display laterally varying amplitudes (surface locations 55 to 68). This region coincides with the high-oil production zone (fractured zone).

Al-Misnid, Abdulaziz Mugbel

1994-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "wave velocity variations" 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

Shock Waves in Plane Symmetric Spacetimes  

E-Print Network (OSTI)

We consider Einstein's equations coupled to the Euler equations in plane symmetry, with compact spatial slices and constant mean curvature time. We show that for a wide variety of equations of state and a large class of initial data, classical solutions break down in finite time. The key mathematical result is a new theorem on the breakdown of solutions of systems of balance laws. We also show that an extension of the solution is possible if the spatial derivatives of the energy density and the velocity are bounded, indicating that the breakdown is really due to the formation of shock waves.

Alan D. Rendall; Fredrik Ståhl

2008-06-10T23:59:59.000Z

302

Plasma transport induced by kinetic Alfven wave turbulence  

SciTech Connect

At the Earth's magnetopause that separates the hot-tenuous magnetospheric plasma from the cold dense solar wind plasma, often seen is a boundary layer where plasmas of both origins coexist. Plasma diffusions of various forms have been considered as the cause of this plasma mixing. Here, we investigate the plasma transport induced by wave-particle interaction in kinetic Alfven wave (KAW) turbulence, which is one of the candidate processes. We clarify that the physical origin of the KAW-induced cross-field diffusion is the drift motions of those particles that are in Cerenkov resonance with the wave: E Multiplication-Sign B-like drift that emerges in the presence of non-zero parallel electric field component and grad-B drift due to compressional magnetic fluctuations. We find that KAW turbulence, which has a spectral breakpoint at which an MHD inertial range transits to a dissipation range, causes selective transport for particles whose parallel velocities are specified by the local Alfven velocity and the parallel phase velocity at the spectral breakpoint. This finding leads us to propose a new data analysis method for identifying whether or not a mixed plasma in the boundary layer is a consequence of KAW-induced transport across the magnetopause. The method refers to the velocity space distribution function data obtained by a spacecraft that performs in situ observations and, in principle, is applicable to currently available dataset such as that provided by the NASA's THEMIS mission.

Izutsu, T. [Department of Earth and Planetary Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 133-0033 (Japan); Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Hasegawa, H.; Fujimoto, M. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Nakamura, T. K. M. [X-Computational Physics Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2012-10-15T23:59:59.000Z

303

Fractional Fourier approximations for potential gravity waves on deep water  

E-Print Network (OSTI)

In the framework of the canonical model of hydrodynamics, where fluid is assumed to be ideal and incompressible, waves are potential, two-dimensional, and symmetric, the authors have recently reported the existence of a new type of gravity waves on deep water besides well studied Stokes waves (Phys. Rev. Lett., 2002, v. 89, 164502). The distinctive feature of these waves is that horizontal water velocities in the wave crests exceed the speed of the crests themselves. Such waves were found to describe irregular flows with stagnation point inside the flow domain and discontinuous streamlines near the wave crests. Irregular flows produce a simple model for describing the initial stage of the formation of spilling breakers when a localized jet is formed at the crest following by generating whitecaps. In the present work, a new highly efficient method for computing steady potential gravity waves on deep water is proposed to examine the above results in more detail. The method is based on the truncated fractional a...

Lukomsky, V P; Lukomsky, Vasyl P.; Gandzha, Ivan S.

2003-01-01T23:59:59.000Z

304

RADIATION WAVE DETECTION  

DOE Patents (OSTI)

Radiation waves can be detected by simultaneously measuring radiation- wave intensities at a plurality of space-distributed points and producing therefrom a plot of the wave intensity as a function of time. To this end. a detector system is provided which includes a plurality of nuclear radiation intensity detectors spaced at equal radial increments of distance from a source of nuclear radiation. Means are provided to simultaneously sensitize the detectors at the instant a wave of radiation traverses their positions. the detectors producing electrical pulses indicative of wave intensity. The system further includes means for delaying the pulses from the detectors by amounts proportional to the distance of the detectors from the source to provide an indication of radiation-wave intensity as a function of time.

Wouters, L.F.

1960-08-30T23:59:59.000Z

305

Shock initiation studies of low density HMX using electromagnetic particle velocity and PVDF stress gauges  

Science Conference Proceedings (OSTI)

Magnetic particle velocity and PVDF stress rate gauges have been used to measure the shock response of low density octotetramethylene tetranitramine (HMX) (1.24 &/cm{sup 3}). In experiments done at LANL, magnetic particle velocity gauges were located on both sides of the explosive. In nearly identical experiments done at SNL, PVDF stress rate gauges were located at the same positions so both particle velocity and stress histories were obtained for a particular experimental condition. Unreacted Hugoniot data were obtained and an EOS was developed by combining methods used by Hayes, Sheffield and Mitchell (for describing the Hugoniot of HNS at various densities) with Hermann`s P-{alpha} model. Using this technique, it is only necessary to know some thermodynamic constants or the Hugoniot of the initially solid material and the porous material sound speed to obtain accurate unreacted Hugoniots for the porous explosive. Loading and reaction paths were established in the stress-particle velocity plane for some experimental conditions. This information was used to determine a global reaction rate of {approx} 0.13 {mu}s{sup {minus}1} for porous HMX shocked to 0.8 GPa. At low input stresses the transmitted wave profiles had long rise times (up to 1 {mu}s) due to the compaction processes.

Sheffield, S.A.; Gustavsen, R.L.; Alcon, R.R. [Los Alamos National Lab., NM (United States); Graham, R.A.; Anderson, M.U. [Sandia National Labs., Albuquerque, NM (United States)

1993-09-01T23:59:59.000Z

306

Compression wave studies in Blair dolomite  

DOE Green Energy (OSTI)

Dynamic compression wave studies have been conducted on Blair dolomite in the stress range of 0-7.0 GPa. Impact techniques were used to generate stress impulse input functions, and diffuse surface laser interferometry provided the dynamic instrumentation. Experimental particle velocity profiles obtained by this method were coupled with the conservation laws of mass and momentum to determine the stress-strain and stress-modulus constitutive properties of the material. Comparison between dynamic and quasistatic uniaxial stress-strain curves uncovered significant differences. Energy dissipated in a complete load and unload cycle differed by almost an order of magnitude and the longitudinal moduli differed by as much as a factor of two. Blair dolomite was observed to yield under dynamic loading at 2.5 GPa. Below 2.5 GPa the loading waves had a finite risetime and exhibited steady propagation. A finite linear viscoelastic constitutive model satisfactorily predicted the observed wave propagation. We speculate that dynamic properties of preexisting cracks provides a physical mechanism for both the rate dependent steady wave behavior and the difference between dynamic and quasistatic response.

Grady, D.E.; Hollenbach, R.E.; Schuler, K.W.; Callender, J.F.

1976-02-01T23:59:59.000Z

307

Group velocity and pulse lengthening of mismatched laser pulses in plasma channels  

SciTech Connect

Analytic solutions are presented to the non-paraxial wave equation describing an ultra-short, low-power, laser pulse propagating in aplasma channel. Expressions for the laser pulse centroid motion and laser group velocity are derived, valid for matched and mismatchedpropagation in a parabolic plasma channel, as well as in vacuum, for an arbitrary Laguerre-Gaussian laser mode. The group velocity of amismatched laser pulse, for which the laser spot size is strongly oscillating, is found to be independent of propagation distance andsignificantly less than that of a matched pulse. Laser pulse lengthening of a mismatched pulse owing to laser mode slippage isexamined and found to dominate over that due to dispersive pulse spreading for sufficiently long pulses. Analytic results are shown tobe in excellent agreement with numerical solutions of the full Maxwell equations coupled to the plasma response. Implications for plasmachannel diagnostics are discussed.

Schroeder, Carl; Benedetti, Carlo; Esarey, Eric; van Tilborg, Jeroen; Leemans, Wim

2011-07-07T23:59:59.000Z

308

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

309

The relationship between ELF-VHF waves and magnetic shear at the dayside magnetopause  

SciTech Connect

ELF-VLF waves within the current layer of the dayside magnetopause are studied using ISEE-1 data. The database consists of 272 current layer crossings at the dayside magnetopause from 1977 to 1979. For each crossing, the average intensity of ELF-VLF waves inside the current layer is obtained and the magnetic shear angle across the current layer is calculated from the magnetometer data. It is found that the wave amplitudes (both electric and magnetic fields), after normalization by the average magnetic field strength in the current layer, are proportional to the local magnetic shear angle, i.e. large magnetic shear corresponds to strong wave emission and vice versa. From the dispersion relation of the waves for different shear angles, the phase velocity of the waves increases with the magnetic shear and peaks around 700 Hz to 1 kHz. The dispersion curve of the waves is consistent with that of whistler modes. 21 refs., 3 fig.

Zhu, Z.; Song, P. [National Center for Atmospheric Research, Boulder, CO (United States)] [and others

1996-04-01T23:59:59.000Z

310

WAVE REFLE TOR  

owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration. SAND # 2013-8893 P WAVE REFLE TOR

311

Energy Basics: Wave Energy  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Energy Basics Renewable Energy Printable Version Share this resource Biomass Geothermal Hydrogen Hydropower Ocean Ocean Thermal Energy Conversion Tidal Energy Wave Energy...

312

WAVE REFLE TOR  

electromagnetic wave travels through the rods along their axes it receives a 1/4 period of phase delay be- ... delay, creating positive interference that effectively

313

Trimodal steady water waves  

E-Print Network (OSTI)

We construct three-dimensional families of small-amplitude gravity-driven rotational steady water waves on finite depth. The solutions contain counter-currents and multiple crests in each minimal period. Each such wave generically is a combination of three different Fourier modes, giving rise to a rich and complex variety of wave patterns. The bifurcation argument is based on a blow-up technique, taking advantage of three parameters associated with the vorticity distribution, the strength of the background stream, and the period of the wave.

Mats Ehrnström; Erik Wahlén

2013-10-31T23:59:59.000Z

314

RFI Comments - Wave Systems  

Science Conference Proceedings (OSTI)

... These attacks, such as those planted by rootkits ... PwC leveraged the power of TPMs to ... Wave EMBASSY® Remote Administration Server (ERAS) has ...

2013-04-09T23:59:59.000Z

315

Collapse of Alfven waves  

SciTech Connect

The growth rates are calculated for the collapse of Alfven waves in a low-..beta.. plasma. The relationship to rf heating is discussed.(AIP)

Erokhin, N.S.; Moiseev, S.S.; Mukhin, V.V.

1977-07-01T23:59:59.000Z

316

Stress-wave velocity of wood-based panels: Effect of moisture,  

E-Print Network (OSTI)

, Associate Professor, College of Ma- terial Science and Engineering, Northeast Forestry University, China (ghan1@lsu.edu); Professor, School of Renewable Natural Re- sources, Louisiana State University

317

Extensional wave attenuation and velocity in partially-saturated sand in the sonic frequency range  

E-Print Network (OSTI)

sands can be viewed as an end-member of the spectrum of naturally-occurring granular materials, with tight

Liu, Z.; Rector, J.W.; Nihei, K.T.; Tomutsa, L.; Myer, L.R.; Nakagawa, S.

2002-01-01T23:59:59.000Z

318

Extensional wave attenuation and velocity in partially saturated sand in the sonic frequency range  

E-Print Network (OSTI)

sands can be viewed as an end-member of the spectrum of naturally-occurring granular materials, with tight

Liu, Z.; Rector, J.W.; Nihei, K.T.; Tomutsa, L.; Myer, L.R.; Nakagawa, S.

2001-01-01T23:59:59.000Z

319

Phase-matching enhanced ion heating by nonresonant Alfven waves  

Science Conference Proceedings (OSTI)

Heating of ions by two Alfven waves propagating along an external magnetic field via nonresonant wave-particle interaction in low-{beta} plasmas is studied using test-particle simulation. Due to subcyclotron ion resonance, the heating effect of the left-hand polarized Alfven wave pair is 10% greater than that of the right-hand polarized pair. The results show that the perpendicular and parallel (to the external magnetic field) temperatures, as well as the parallel fluid velocity, vary sinusoidally with the phase difference. Furthermore, the magnitude of the oscillations decreases with the ratio of the frequencies of the two waves. When the frequency ratio reaches above 2, the effect of the phase difference vanishes.

Li Kehua [School of Nuclear Science and Technology, University of South China, Hengyang 421001 (China); Department of Nuclear Engineering and New Energy, The Engineering and Technical College of Chengdu University of Technology, Leshan 614000 (China); Gong Xueyu; Lu Xingqiang; Li Xinxia [School of Nuclear Science and Technology, University of South China, Hengyang 421001 (China); Guo Wei [School of Electrical Engineering, University of South China, Hengyang 421001 (China)

2012-07-15T23:59:59.000Z

320

Amplitude variations on the Extreme Adaptive Optics testbed  

Science Conference Proceedings (OSTI)

High-contrast adaptive optics systems, such as those needed to image extrasolar planets, are known to require excellent wavefront control and diffraction suppression. At the Laboratory for Adaptive Optics on the Extreme Adaptive Optics testbed, we have already demonstrated wavefront control of better than 1 nm rms within controllable spatial frequencies. Corresponding contrast measurements, however, are limited by amplitude variations, including those introduced by the micro-electrical-mechanical-systems (MEMS) deformable mirror. Results from experimental measurements and wave optic simulations of amplitude variations on the ExAO testbed are presented. We find systematic intensity variations of about 2% rms, and intensity variations with the MEMS to be 6%. Some errors are introduced by phase and amplitude mixing because the MEMS is not conjugate to the pupil, but independent measurements of MEMS reflectivity suggest that some error is introduced by small non-uniformities in the reflectivity.

Evans, J; Thomas, S; Dillon, D; Gavel, D; Phillion, D; Macintosh, B

2007-08-14T23:59:59.000Z

Note: This page contains sample records for the topic "wave velocity variations" 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

Scattering of Coastal-Trapped Waves by Irregularities in Coastline and Topography  

Science Conference Proceedings (OSTI)

The scattering of freely-propapting coastal-trapped waves (CTWs) by large variations in coastline and topography is studied using a numerical model which accomodates arbitrary density stratification, bathymetry and coastline. Particular attention ...

John L. Wilkin; David C. Chapman

1990-03-01T23:59:59.000Z

322

Analysis of the Pyrenees Lee Wave Event of 23 March 1982  

Science Conference Proceedings (OSTI)

The results of an independent analysis of mountain wave data gathered by instrumented aircraft during flights over the Pyrenees on 23 March 1982, as part of ALPEX, are presented. The prior synoptic development, cross-flow variation, vertical ...

Karl W. Cox

1986-06-01T23:59:59.000Z

323

The Seasonal Cycle of Gravity Wave Drag in the Middle Atmosphere  

Science Conference Proceedings (OSTI)

Using a variational technique, middle atmosphere gravity wave drag (GWD) is estimated from Met Office middle atmosphere analyses for the year 2002. The technique employs an adjoint model of a middle atmosphere dynamical model to minimize a cost ...

Manuel Pulido; John Thuburn

2008-09-01T23:59:59.000Z

324

Coastal-Trapped Waves off the Coast of South Africa: Generation, Propagation and Current Structures  

Science Conference Proceedings (OSTI)

Coastal sea level variations from six sites around South Africa are used to establish the characteristics of coastal-trapped wave (CTW) propagation. Substantial amplitudes (>50 cm) are found along the south coast, but further propagation on the ...

E. H. Schumann; K. H. Brink

1990-08-01T23:59:59.000Z

325

Analysis of Gravity Waves during the POLINAT Experiment and Some Consequences for Stratosphere–Troposphere Exchange  

Science Conference Proceedings (OSTI)

Measurements of horizontal wind speed and direction obtained during the Pollution from Aircraft Emissions in the North Atlantic Flight Corridor experiment are used to identify some waves propagating near the tropopause level. The variation ...

M. Moustaoui; H. Teitelbaum; P. F. J. van Velthoven; H. Kelder

1999-04-01T23:59:59.000Z

326

Unexplored Aspect of Velocity of light  

E-Print Network (OSTI)

In the post-Maxwellian era, sensing that the tide of discoveries in electromagnetim indicated a decline of the mechanical view, Einstein replaced Newton's three absolutes -- space, time and mass, with a single one, the velocity of light. The magnitude of the velocity of light was first determined and proven to be finite independently by Ole Romer and Bradley in the eighteenth century. In the nineteenth century, Fizeau carried out the first successful measurement of the speed of light using an earthbound apparatus. Thereafter, many earthbound experiments were conducted for its determination till 1983, when its magnitude was frozen at a fixed value after it was determined up to an accuracy level of a fraction of a meter per second. Einstein considered the speed of light derived from terrestrial experiments, to be the limiting speed of all natural phenomena. Einstein stated in connection with his general relativity theory that light rays could curve only when the velocity of propagation of light varies with position. Experiments have been conducted to prove the phenomenon of light deflection to higher and higher accuracy levels, but none so far to determine the speed of light at locations closer to the sun. To verify some essential aspects of general relativity, NASA had commendably planned many costly experiments. Hence, NASA can now be expected to expeditiously plan and execute the low cost experiment proposed here, so as to conclusively verify the effect of the solar gravitational field on the speed of light, as regards the important predictions of Einstein's theory of gravitation and of its remodeled form -- the Remodeled Relativity Theory, which retained and incorporated only experimentally proven concepts and principles.

Abhijit Biswas; Krishnan RS Mani

2008-05-13T23:59:59.000Z

327

Laser Doppler Velocimeter particle velocity measurement system  

DOE Green Energy (OSTI)

This report gives a detailed description of the operation of the Laser Doppler Velocimeter (LDV) system maintained by DIAL at MSU. LDV is used for the measurement of flow velocities and turbulence levels in various fluid flow settings. Ills report details the operation and maintenance of the LDV system and provides a first-time user with pertinent information regarding the system`s setup for a particular application. Particular attention has been given to the use of the Doppler signal analyzer (DSA) and the burst spectrum analyzer (BSA) signal processors and data analysis.

Wilson, W.W.; Srikantaiah, D.V.; Philip, T.; George, A.

1993-10-01T23:59:59.000Z

328

The influence of an electromagnetic field on the wave-current interaction  

E-Print Network (OSTI)

We study the propagation of surface waves on a current in the presence of an electromagnetic field. A horizontal (vertical) field strengthens (weakens) the counter-current which blocks the waves. We compute the phase space diagrams (blocking velocities versus period of the waves) with and without surface tension. Three new dimensionless numbers are introduced to compare the relative strengths of gravity, surface tension and field effects. This work shows the importance of an electromagnetic field in order to design wave-breakers or in microfluidics applications.

Germain Rousseaux; Philippe Maïssa

2010-10-11T23:59:59.000Z

329

Generation of Ultrahigh-Velocity Ionizing Shocks with Petawatt-Class Laser Pulses  

Science Conference Proceedings (OSTI)

Ultrahigh-velocity shock waves (approx10 000 km/s or 0.03c) are generated by focusing a 350-TW laser pulse into low-density helium gas. The collisionless ultrahigh-Mach-number electrostatic shock propagates from the plasma into the surrounding gas, ionizing gas as it becomes collisional. The shock undergoes a corrugation instability due to propagation of the ionizing shock within the gas (the Dyakov-Kontorovich instability). This system may be relevant to the study of very high-Mach-number ionizing shocks in astrophysical situations.

Nilson, P. M.; Mangles, S. P. D.; Willingale, L.; Kaluza, M. C.; Thomas, A. G. R.; Najmudin, Z.; Evans, R. G.; Dangor, A. E.; Krushelnick, K. [Department of Physics, Imperial College, London SW7 2AZ United Kingdom (United Kingdom); Tatarakis, M.; Lancaster, K. L. [Technological Educational Institute of Crete, Romanou, 3-GR73133 Chania (Greece); Clarke, R. J. [CLF, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon., OX11 0QX United Kingdom (United Kingdom); Karsch, S. [Max-Planck Institut fuer Quantenoptik, Hans-Kopfermann-Strasse, D-85748, Garching (Germany); Schreiber, J. [Max-Planck Institut fuer Quantenoptik, Hans-Kopfermann-Strasse, D-85748, Garching (Germany); Ludwig-Maximilians-Universistaet Munchen, Am Coulombwall, D-85748, Garching (Germany)

2009-12-18T23:59:59.000Z

330

Persistent Near-Diurnal Internal Waves Observed above a Site of M2 Barotropic-to-Baroclinic Conversion  

Science Conference Proceedings (OSTI)

Near-diurnal internal waves were observed in velocity and shear measurements from a shipboard survey along a 35-km section of the Kaena Ridge, northwest of Oahu. Individual waves with upward phase propagation could be traced for almost 4 days ...

Glenn S. Carter; Michael C. Gregg

2006-06-01T23:59:59.000Z

331

A Synoptic-Scale Wave of 6–9-Day Period in the Atlantic Tropical Troposphere during Summer 1981  

Science Conference Proceedings (OSTI)

Using the ECMWF analyses, this study documents a tropospheric synoptic-scale wave in the tropical Atlantic during summer 1981. It has a 6–9-day period and a westward velocity of about 8.5° longitude per day. The wave structure has features ...

P. de Felice; A. Viltard; J. Oubuih

1993-05-01T23:59:59.000Z

332

Free-Wave Energy Dissipation in Experimental Breaking Waves  

Science Conference Proceedings (OSTI)

Several transient wave trains containing an isolated plunging or spilling breaker at a prescribed location were generated in a two-dimensional wave flume using an energy focusing technique. Surface elevation measurements of each transient wave ...

Eustorgio Meza; Jun Zhang; Richard J. Seymour

2000-09-01T23:59:59.000Z

333

HALO VELOCITY GROUPS IN THE PISCES OVERDENSITY  

Science Conference Proceedings (OSTI)

We report spectroscopic observations of five faint (V {approx} 20) RR Lyrae stars associated with the Pisces overdensity conducted with the Gemini South Telescope. At a heliocentric and galactocentric distance of {approx}80 kpc, this is the most distant substructure in the Galactic halo known to date. We combined our observations with literature data and confirmed that the substructure is composed of two different kinematic groups. The main group contains eight stars and has (V{sub gsr}) = 50 km s{sup -1}, while the second group contains four stars at a velocity of (V{sub gsr}) = -52 km s{sup -1}, where V{sub gsr} is the radial velocity in the galactocentric standard of rest. The metallicity distribution of RR Lyrae stars in the Pisces overdensity is centered on [Fe/H] = -1.5 dex and has a width of 0.3 dex. The new data allowed us to establish that both groups are spatially extended making it very unlikely that they are bound systems, and are more likely to be debris of a tidally disrupted galaxy or galaxies. Due to small sky coverage, it is still unclear whether these groups have the same or different progenitors.

Sesar, Branimir; Ivezic, Zeljko [Department of Astronomy, University of Washington, P.O. Box 351580, Seattle, WA 98195-1580 (United States); Vivas, A. Katherina [Centro de Investigaciones de Astronomia (CIDA), Apartado Postal 264, Merida 5101-A (Venezuela, Bolivarian Republic of); Duffau, Sonia, E-mail: bsesar@u.washington.ed, E-mail: zi@u.washington.ed, E-mail: akvivas@cida.v, E-mail: sonia.duffau@gmail.co [Astronomisches Rechen-Institut, Zentrum fuer Astronomie der Universitaet Heidelberg, Moenchhofstrasse 12-14, D-69120 Heidelberg (Germany)

2010-07-01T23:59:59.000Z

334

Perturbations in high-velocity gas flow  

DOE Green Energy (OSTI)

High velocity explosive products or other low-density gases are often used to accelerate metal plates to high velocities. Perturbations in otherwise uniform flow configurations are sometimes sufficient to cause interactions that can rapidly destroy the integrity of the plates. In this study perturbations were introduced in uniform gas flows of detonated HE products and strongly shocked polyethylene, CH{sub 2}. The primary diagnostics were smear-camera records obtained when these gases impinged on layers of plexiglas separated by small argon-filled gaps. These records show shock-arrival times at various levels and thus determine not only the size of the perturbation but also its strength. Perturbations in HE gases running into H{sub 2} and in CH{sub 2} into H{sub 2} have been studied. Two-dimensional hydrodynamic calculations are in excellent agreement with the experiments, and enable one to study details of the flow not possible from experimental results. 1 ref., 5 figs.

Harvey, W.B.; McQueen, R.G. (Los Alamos National Lab., NM (USA))

1989-01-01T23:59:59.000Z

335

Radar Wind Profiler Radial Velocity: A Comparison with Doppler Lidar  

Science Conference Proceedings (OSTI)

The accuracy of the radial wind velocity measured with a radar wind profiler will depend on turbulent variability and instrumental noise. Radial velocity estimates of a boundary layer wind profiler are compared with those estimated by a Doppler ...

Stephen A. Cohn; R. Kent Goodrich

2002-12-01T23:59:59.000Z

336

The Accuracy of Vertical Air Velocities from Doppler Radar Data  

Science Conference Proceedings (OSTI)

Eight methods of calculating vertical air velocity in a column are compared. Each method requires some or all of the following data: horizontal divergence, vertical precipitation velocity, hydrometeor terminal fall speed, and vertical air ...

Thomas Matejka; Diana L. Bartels

1998-01-01T23:59:59.000Z

337

Diagnosing Mesoscale Vertical Motion from Horizontal Velocity and Density Data  

Science Conference Proceedings (OSTI)

The mesoscale vertical velocity is obtained by solving a generalized omega equation (? equation) using density and horizontal velocity data from three consecutive quasi-synoptic high-resolution surveys in the Alboran Sea. The Atlantic Jet (AJ) ...

Enric Pallàs Sanz; Álvaro Viúdez

2005-10-01T23:59:59.000Z

338

Terminal Velocity Adjustments for Plate-like Crystals and Graupel  

Science Conference Proceedings (OSTI)

Velocity adjustments are evaluated for altitude changes using Reynolds number-Davies number correlations of the form Re = aXb which have been obtained from empirical fall velocities of ice particles. In general, the altitude adjustment was found ...

Kenneth V. Beard; Andrew J. Heymsfield

1988-11-01T23:59:59.000Z

339

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

Science Conference Proceedings (OSTI)

The objective of our research was to develop and demonstrate seismic data-acquisition and data-processing technologies that allow geothermal prospects below high-velocity rock outcrops to be evaluated. To do this, we acquired a 3-component seismic test line across an area of exposed high-velocity rocks in Brewster County, Texas, where there is high heat flow and surface conditions mimic those found at numerous geothermal prospects. Seismic contractors have not succeeded in creating good-quality seismic data in this area for companies who have acquired data for oil and gas exploitation purposes. Our test profile traversed an area where high-velocity rocks and low-velocity sediment were exposed on the surface in alternating patterns that repeated along the test line. We verified that these surface conditions cause non-ending reverberations of Love waves, Rayleigh waves, and shallow critical refractions to travel across the earth surface between the boundaries of the fast-velocity and slow-velocity material exposed on the surface. These reverberating surface waves form the high level of noise in this area that does not allow reflections from deep interfaces to be seen and utilized. Our data-acquisition method of deploying a box array of closely spaced geophones allowed us to recognize and evaluate these surface-wave noise modes regardless of the azimuth direction to the surface anomaly that backscattered the waves and caused them to return to the test-line profile. With this knowledge of the surface-wave noise, we were able to process these test-line data to create P-P and SH-SH images that were superior to those produced by a skilled seismic data-processing contractor. Compared to the P-P data acquired along the test line, the SH-SH data provided a better detection of faults and could be used to trace these faults upward to the boundaries of exposed surface rocks. We expanded our comparison of the relative value of S-wave and P-wave seismic data for geothermal applications by inserting into this report a small part of the interpretation we have done with 3C3D data across Wister geothermal field in the Imperial Valley of California. This interpretation shows that P-SV data reveal faults (and by inference, also fractures) that cannot be easily, or confidently, seen with P-P data, and that the combination of P-P and P-SV data allows VP/VS velocity ratios to be estimated across a targeted reservoir interval to show where an interval has more sandstone (the preferred reservoir facies). The conclusion reached from this investigation is that S-wave seismic technology can be invaluable to geothermal operators. Thus we developed a strong interest in understanding the direct-S modes produced by vertical-force sources, particularly vertical vibrators, because if it can be demonstrated that direct-S modes produced by vertical-force sources can be used as effectively as the direct-S modes produced by horizontal-force sources, geothermal operators can acquire direct-S data across many more prospect areas than can be done with horizontal-force sources, which presently are limited to horizontal vibrators. We include some of our preliminary work in evaluating direct-S modes produced by vertical-force sources.

Hardage, Bob A; DeAngelo, Michael V; Ermolaeva, Elena; Hardage, Bob A; Remington, Randy; Sava, Diana; Wagner, Donald; Wei, Shuijion

2013-02-28T23:59:59.000Z

340

Resonantly Forced Rossby Waves  

Science Conference Proceedings (OSTI)

A shallow, rotating layer of fluid that supports Rossby waves is subjected to turbulent friction through an Ekman layer at the bottom and is driven by a wave that exerts a shear stress on the upper boundary and for which the phase approximate ...

John Miles

1985-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "wave velocity variations" 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

Wave Energy Conversion Technology  

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

Wave Energy Conversion Technology Wave Energy Conversion Technology Speaker(s): Mirko Previsic Date: August 2, 2001 - 12:00pm Location: Bldg. 90 Seminar Host/Point of Contact: Julie Osborn Scientists have been working on wave power conversion for the past twenty years, but recent advances in offshore and IT technologies have made it economically competitive. Sea Power & Associates is a Berkeley-based renewable energy technology company. We have developed patented technology to generate electricity from ocean wave energy using a system of concrete buoys and highly efficient hydraulic pumps. Our mission is to provide competitively priced, non-polluting, renewable energy for coastal regions worldwide. Mirko Previsic, founder and CEO, of Sea Power & Associates will discuss ocean wave power, existing technologies for its conversion into

342

Surface plasma wave excitation via laser irradiated overdense plasma foil  

SciTech Connect

A laser irradiated overdense plasma foil is seen to be susceptible to parametric excitation of surface plasma wave (SPW) and ion acoustic wave (IAW) on the ion plasma period time scale. The SPW is localised near the front surface of the foil while IAW extends upto the rear. The evanescent laser field and the SPW exert a ponderomotive force on electrons driving the IAW. The density perturbation associated with the latter beats with the laser induced oscillatory electron velocity to drive the SPW. At relativistic laser intensity, the growth rate is of the order of ion plasma frequency.

Kumar, Pawan; Tripathi, V. K. [Department of Physics, Indian Institute of Technology Delhi, New Delhi 110 016 (India)

2012-04-09T23:59:59.000Z

343

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

344

Method and apparatus for millimeter-wave detection of thermal waves for materials evaluation  

DOE Patents (OSTI)

A method and apparatus for generating thermal waves in a sample and for measuring thermal inhomogeneities at subsurface levels using millimeter-wave radiometry. An intensity modulated heating source is oriented toward a narrow spot on the surface of a material sample and thermal radiation in a narrow volume of material around the spot is monitored using a millimeter-wave radiometer; the radiometer scans the sample point-by-point and a computer stores and displays in-phase and quadrature phase components of thermal radiations for each point on the scan. Alternatively, an intensity modulated heating source is oriented toward a relatively large surface area in a material sample and variations in thermal radiation within the full field of an antenna array are obtained using an aperture synthesis radiometer technique.

Gopalsami, Nachappa (Naperville, IL); Raptis, Apostolos C. (Downers Grove, IL)

1991-01-01T23:59:59.000Z

345

Wave Mechanics without Probability  

E-Print Network (OSTI)

The behavior of monochromatic electromagnetic waves in stationary media is shown to be ruled by a frequency dependent function, which we call Wave Potential, encoded in the structure of the Helmholtz equation. Contrary to the common belief that the very concept of "ray trajectory" is reserved to the eikonal approximation, a general and exact ray-based Hamiltonian treatment, reducing to the eikonal approximation in the absence of Wave Potential, shows that its presence induces a mutual, perpendicular ray-coupling, which is the one and only cause of any typically wave-like phenomenon, such as diffraction and interference. Recalling, then, that the time-independent Schroedinger and Klein-Gordon equations (associating stationary "matter waves" to mono-energetic particles) are themselves Helmholtz-like equations, the exact, ray-based treatment developed for classical electromagnetic waves is extended - without resorting to statistical concepts - to the exact, trajectory-based Hamiltonian dynamics of mono-energetic point-like particles, both in the non-relativistic and in the relativistic case. The trajectories turn out to be perpendicularly coupled, once more, by an exact, stationary, energy-dependent Wave Potential, coinciding in the form, but not in the physical meaning, with the statistical, time-varying, energy-independent "Quantum Potential" of Bohm's theory, which views particles, just like the standard Copenhagen interpretation, as traveling wave-packets. These results, together with the connection which is shown to exist between Wave Potential and Uncertainty Principle, suggest a novel, non-probabilistic interpretation of Wave Mechanics.

Adriano Orefice; Raffaele Giovanelli; Domenico Ditto

2013-02-18T23:59:59.000Z

346

Towards Reliable 5Gbps Wave-pipelined and 3Gbps Surfing Interconnect in 65nm FPGAs  

E-Print Network (OSTI)

of Computer Science University of British Columbia bwinters,mrg¡ @cs.ubc.ca Abstract This paper presentsA Negative-Overhead, Self-Timed Pipeline Brian D. Winters and Mark R. Greenstreet Department a novel variation of wave pipelining that we call "surfing." In previous wave pipelined designs, timing

Lemieux, Guy

347

A new two-component system modelling shallow-water waves  

E-Print Network (OSTI)

For propagation of surface shallow-water waves on irrotational flows, we derive a new two-component system. The system is obtained by a variational approach in the Lagrangian formalism. The system has a non-canonical Hamiltonian formulation. We also find its exact solitary-wave solutions.

Delia Ionescu-Kruse

2013-05-22T23:59:59.000Z

348

Real time mass flux measurements of gas-solid suspensions at low velocities  

SciTech Connect

In previous work, measurement of the particulate mass flux was made based upon a novel electrostatic technique. A small conducting wire sensor was inserted in the flow and as each particle hit the sensor an individual pulse of current was identified. Through suitable electronic circuitry, the number of pulses in a given time were counted. This was a direct measure of the number of particle-probe collisions which was related to local particle mass flow. The technique is currently limited to monodisperse suspensions. A primary advantage of the impact counter system is that the output does not depend upon the magnitude of the actual charge transfer. As long as the pulses are sufficiently above the noise level, variations in charge transfer will not affect the measurement. For the current work, the technique was applied to vertical gas-solid flow where the fluid velocity was slightly above the particle terminal velocity. Under these conditions a sufficient signal to noise ratio was not found. The Cheng-Soo charge transfer theory indicated that the low particle-sensor impact velocity was responsible. The probe system was then modified by extracting a particulate sample isokinetically and accelerating the particles to a sufficient velocity by an area reduction in the sampling tube. With this technique the signal to noise ratio was about 12 to 1. Mass flux results are shown to compare favorably with filter collection and weighing.

Saunders, J H; Chao, B T; Soo, S L

1981-01-01T23:59:59.000Z

349

PLASMA DIAGNOSTICS OF AN EIT WAVE OBSERVED BY HINODE/EIS AND SDO/AIA  

Science Conference Proceedings (OSTI)

We present plasma diagnostics of an Extreme-Ultraviolet Imaging Telescope (EIT) wave observed with high cadence in Hinode/Extreme-Ultraviolet Imaging Spectrometer (EIS) sit-and-stare spectroscopy and Solar Dynamics Observatory/Atmospheric Imaging Assembly imagery obtained during the HOP-180 observing campaign on 2011 February 16. At the propagating EIT wave front, we observe downward plasma flows in the EIS Fe XII, Fe XIII, and Fe XVI spectral lines (log T Almost-Equal-To 6.1-6.4) with line-of-sight (LOS) velocities up to 20 km s{sup -1}. These redshifts are followed by blueshifts with upward velocities up to -5 km s{sup -1} indicating relaxation of the plasma behind the wave front. During the wave evolution, the downward velocity pulse steepens from a few km s{sup -1} up to 20 km s{sup -1} and subsequently decays, correlated with the relative changes of the line intensities. The expected increase of the plasma densities at the EIT wave front estimated from the observed intensity increase lies within the noise level of our density diagnostics from EIS Fe XIII 202/203 A line ratios. No significant LOS plasma motions are observed in the He II line, suggesting that the wave pulse was not strong enough to perturb the underlying chromosphere. This is consistent with the finding that no H{alpha} Moreton wave was associated with the event. The EIT wave propagating along the EIS slit reveals a strong deceleration of a Almost-Equal-To -540 m s{sup -2} and a start velocity of v{sub 0} Almost-Equal-To 590 km s{sup -1}. These findings are consistent with the passage of a coronal fast-mode MHD wave, pushing the plasma downward and compressing it at the coronal base.

Veronig, A. M.; Kienreich, I. W.; Muhr, N.; Temmer, M. [Institute of Physics, University of Graz, Universitaetsplatz 5, A-8010 Graz (Austria); Goemoery, P. [Astronomical Institute, Slovak Academy of Sciences, SK-05960 Tatranska Lomnica (Slovakia); Vrsnak, B. [Hvar Observatory, Faculty of Geodesy, Kaciceva 26, 1000 Zagreb (Croatia); Warren, H. P., E-mail: astrid.veronig@uni-graz.at [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

2011-12-10T23:59:59.000Z

350

Program on Technology Innovation: Effect of Seismic Wave Incoherence on Foundation and Building Response  

Science Conference Proceedings (OSTI)

Task S2.1 of the New Plant Seismic Issues Resolution Programa joint effort of EPRI and the Department of Energy (DOE)entails a research program into the effect of seismic wave incoherence on foundation and building response. The tasks objective is to systematically study seismic wave incoherence effects on structures/foundations similar to those being considered for advanced reactor designs. Seismic wave incoherence occurs because of horizontal spatial variation of both horizontal and vertical ground mot...

2006-11-15T23:59:59.000Z

351

The Case of Sharp Velocity Transitions in High Vertical Wind Shear When Measuring Doppler Velocities with Narrow Nyquist Intervals  

Science Conference Proceedings (OSTI)

An investigation was launched following unexpected observations of step-function transitions in Doppler velocities from scanning radars in regions of high vertical wind shear. It revealed that, if wind velocity transitions are sufficiently sharp ...

Frédéric Fabry; Clotilde Augros; Aldo Bellon

2013-03-01T23:59:59.000Z

352

Acoustic wave propagation in a fluid-filled borehole surrounded by a formation with stress-relief-induced anisotropy  

SciTech Connect

The stress relief associated with the drilling of a borehole may lead to an anisotropic formation in the vicinity of the borehole, where the properties in the radial direction differ from those in the axial and tangential directions. Thus, axial and radial compressional acoustic velocities are different, and similarly, the velocity of an axial shear-wave depends on whether the polarization is radial or tangential. A model was developed to describe acoustic wave propagation in a borehole surrounded by a formation with stress-relief-induced radial transverse isotropy (RTI). Acoustic full waveforms due to a monopole source are computed using the real-axis integration method, and dispersion relations are found by tracing poles in the k[sub z] plane. An analytic expression for the low-frequency Stoneley wave is developed. The numerical results confirm the expectations that the compressional refraction is mainly given by the axial compressional velocity, while the shear refraction arrival is due to the shear wave with radial polarization. As a result, acoustic logging in an RTI formation, will indicate a higher v[sub p]/v[sub s] ratio than that existing in the virgin formation. It also follows that the shear velocity may be a better indicator of a mechanically damaged zone near the borehole than the compressional velocity. The Stoneley-wave velocity was found to decrease with the increasing degree of RTI.

Renlie, L. (IKU Petroleum Research, Trondheim (Norway)); Raaen, A.M. (Statoil, Postuttak, Trondheim (Norway))

1993-09-01T23:59:59.000Z

353

German Shepard Variations  

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

German Shepard Variations German Shepard Variations Name: Kyle Status: Student Grade: 4-5 Location: Outside U.S. Country: USA Date: Winter 2009-2010 Question: What are all the different colors a German shepherd can have? Replies: Hi Kyle, This seems like a simple question - yet for German Shepherds it is not so easy to answer because they can be many colors! They can range from solid black to the more common black, tan and white that many people are familiar with, to completely white. The founder of the breed, Max von Stephanitz, has been quoted as saying "No good dog is a bad color". Although they come in many colors, completely white shepherds are not allowed to compete in dog shows in the US, although they are in the UK. German Shepherds whose noses are not completely black are also disqualified from the show ring and dogs with blue, liver or other pale colors in their coats are also not ranked highly.

354

Variational Inequalities and Economic Equilibrium  

Science Conference Proceedings (OSTI)

Variational inequality representations are set up for a general Walrasian model of consumption and production with trading in a market. The variational inequalities are of functional rather than geometric type and therefore are able to accommodate a ... Keywords: Walrasian economic equilibrium, complementarity problems, equilibrium computations, equilibrium constraints, functional variational inequalities

Alejandro Jofré; R. Terry Rockafellar; Roger J-B. Wets

2007-02-01T23:59:59.000Z

355

Wave Energy | Department of Energy  

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

turn, rotates a turbine. Specially built seagoing vessels can also capture the energy of offshore waves. These floating platforms create electricity by funneling waves through...

356

Wave Energy | Open Energy Information  

Open Energy Info (EERE)

TODO: Add description List of Wave Energy Incentives Retrieved from "http:en.openei.orgwindex.php?titleWaveEnergy&oldid267203" Category: Articles with outstanding TODO tasks...

357

Force-velocity relations for multiple-molecular-motor transport  

E-Print Network (OSTI)

A transition rate model of cargo transport by $N$ molecular motors is proposed. Under the assumption of steady state, the force-velocity curve of multi-motor system can be derived from the force-velocity curve of single motor. Our work shows, in the case of low load, the velocity of multi-motor system can decrease or increase with increasing motor number, which is dependent on the single motor force-velocity curve. And most commonly, the velocity decreases. This gives a possible explanation to some recent

Ziqing Wang; Ming Li

2009-06-26T23:59:59.000Z

358

Hohlraum Designs for High Velocity Implosions on NIF  

Science Conference Proceedings (OSTI)

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

359

Evaluation of a Wind-Wave System for Ensemble Tropical Cyclone Wave Forecasting. Part II: Waves  

Science Conference Proceedings (OSTI)

A wind-wave forecast system, designed with the intention of generating unbiased ensemble wave forecasts for extreme wind events, is assessed. Wave hindcasts for 12 tropical cyclones (TCs) are forced using a wind analysis produced from a ...

Steven M. Lazarus; Samuel T. Wilson; Michael E. Splitt; Gary A. Zarillo

2013-04-01T23:59:59.000Z

360

wave | OpenEI  

Open Energy Info (EERE)

9 9 Varnish cache server Browse Upload data GDR 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation: XID: 2142281559 Varnish cache server wave Dataset Summary Description This project estimates the naturally available and technically recoverable U.S. wave energy resources, using a 51-month Wavewatch III hindcast database developed especially for this study by National Oceanographic and Atmospheric Administration's (NOAA's) National Centers for Environmental Prediction. For total resource estimation, wave power density in terms of kilowatts per meter is aggregated across a unit diameter circle. Source Electric Power Research Institute (EPRI) Date Released December 05th, 2011 (3 years ago) Date Updated Unknown Keywords

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361

System and method to estimate compressional to shear velocity (VP/VS) ratio in a region remote from a borehole  

DOE Patents (OSTI)

In some aspects of the disclosure, a method for creating three-dimensional images of non-linear properties and the compressional to shear velocity ratio in a region remote from a borehole using a conveyed logging tool is disclosed. In some aspects, the method includes arranging a first source in the borehole and generating a steered beam of elastic energy at a first frequency; arranging a second source in the borehole and generating a steerable beam of elastic energy at a second frequency, such that the steerable beam at the first frequency and the steerable beam at the second frequency intercept at a location away from the borehole; receiving at the borehole by a sensor a third elastic wave, created by a three wave mixing process, with a frequency equal to a difference between the first and second frequencies and a direction of propagation towards the borehole; determining a location of a three wave mixing region based on the arrangement of the first and second sources and on properties of the third wave signal; and creating three-dimensional images of the non-linear properties using data recorded by repeating the generating, receiving and determining at a plurality of azimuths, inclinations and longitudinal locations within the borehole. The method is additionally used to generate three dimensional images of the ratio of compressional to shear acoustic velocity of the same volume surrounding the borehole.

Vu, Cung; Nihei, Kurt T; Schmitt, Denis P; Skelt, Christopher; Johnson, Paul A; Guyer, Robert; TenCate, James A; Le Bas, Pierre-Yves

2012-10-16T23:59:59.000Z

362

QUASI-PERIODIC FAST-MODE WAVE TRAINS WITHIN A GLOBAL EUV WAVE AND SEQUENTIAL TRANSVERSE OSCILLATIONS DETECTED BY SDO/AIA  

SciTech Connect

We present the first unambiguous detection of quasi-periodic wave trains within the broad pulse of a global EUV wave (so-called EIT wave) occurring on the limb. These wave trains, running ahead of the lateral coronal mass ejection (CME) front of 2-4 times slower, coherently travel to distances {approx}> R{sub Sun }/2 along the solar surface, with initial velocities up to 1400 km s{sup -1} decelerating to {approx}650 km s{sup -1}. The rapid expansion of the CME initiated at an elevated height of 110 Mm produces a strong downward and lateral compression, which may play an important role in driving the primary EUV wave and shaping its front forwardly inclined toward the solar surface. The wave trains have a dominant 2 minute periodicity that matches the X-ray flare pulsations, suggesting a causal connection. The arrival of the leading EUV wave front at increasing distances produces an uninterrupted chain sequence of deflections and/or transverse (likely fast kink mode) oscillations of local structures, including a flux-rope coronal cavity and its embedded filament with delayed onsets consistent with the wave travel time at an elevated (by {approx}50%) velocity within it. This suggests that the EUV wave penetrates through a topological separatrix surface into the cavity, unexpected from CME-caused magnetic reconfiguration. These observations, when taken together, provide compelling evidence of the fast-mode MHD wave nature of the primary (outer) fast component of a global EUV wave, running ahead of the secondary (inner) slow component of CME-caused restructuring.

Liu Wei; Nitta, Nariaki V.; Aschwanden, Markus J.; Schrijver, Carolus J.; Title, Alan M.; Tarbell, Theodore D. [Lockheed Martin Solar and Astrophysics Laboratory, 3251 Hanover Street, Palo Alto, CA 94304 (United States); Ofman, Leon, E-mail: weiliu@lmsal.com [Department of Physics, Catholic University of America, Washingtom, DC 20064 (United States)

2012-07-01T23:59:59.000Z

363

Dynamics of Wave Breaking at a Coastal Sea Wall  

E-Print Network (OSTI)

Structural designs barely consider the dynamic scenario of a well-developed impinging wave hitting the structure. The usual area of focus is on static and stability factors (e.g. drag, inertia, resistive forces related to weight, buoyancy, sliding etc). Even the "Factor of Safety" which is regularly used in designs to account for unknown and/or unforeseen situations which might occur implies a degree of uncertainty about the dynamic scenario of breaking waves in the coastal environment. In the present study the hydrodynamics of a coastal structure-turbulent bore interaction was studied by examination (two-dimensional) of the singular case of a plunging breaking wave forming a well developed turbulent bore which impacted on a model sea wall structure. The turbulent bore impact event was found to display similar characteristics to the impact event of other wave shapes, in particular that of a plunging breaker. Examination of the impact event confirmed the conversion of nearly all horizontal velocity to vertical velocity during the "flip through" event. In accordance with theoretical expectations the location of maximum pressure was found to occur just below the still water level (SWL). Resulting pressure data in the present study consisted of two blunt spikes as opposed to the "church-roof" (high spike) shape seen in other results. The shape of the pressure data was attributed to the following: firstly, to the initial impact of the protruding jet of the breaking wave which causes the first maxima, secondly, to the sensor encountering the bulk of the entrapped air hence causing the drop in pressure between the blunt spikes and lastly, to the inherent hydrostatic pressure combined with the compression of the entrapped air bubbles, by the subsequent forward motion of the water within the wave, which causes the second maxima. The point of maximum pressure was found to always be within the second maxima. Observation of the turbulent bore-structure interaction showed that the consequential maximum pressure was a direct result of the compression of entrapped air by the weight of the water in the wave as it continued forward onto the structure combined with the inherent hydrostatic pressure of the wave. The project was conducted in an attempt to contribute to the vast knowledge of coastal structure-wave interactions and to add to the understanding of the physics and characteristics of breaking waves. Whilst numerous studies and experiments have been carried out on the phenomenon of breaking waves by previous researchers the current project highlights the advent of new equipment and technological advances in existing methods.

Antoine, Arthur L.

2009-12-01T23:59:59.000Z

364

Linear and nonlinear coupled drift and ion acoustic waves in collisional pair ion-electron magnetoplasma  

SciTech Connect

Linear and nonlinear coupled electrostatic drift and ion acoustic waves are studied in inhomogeneous, collisional pair ion-electron plasma. The Korteweg-de Vries-Burgers (KdVB) equation for a medium where both dispersion and dissipation are present is derived. An attempt is made to obtain exact solution of KdVB equation by using modified tanh-coth method for arbitrary velocity of nonlinear drift wave. Another exact solution for KdVB is obtained, which gives a structure of shock wave. Korteweg-de Vries (KdV) and Burgers equations are derived in limiting cases with solitary and monotonic shock solutions, respectively. Effects of species density, magnetic field, obliqueness, and the acoustic to drift velocity ratio on the solitary and shock solutions are investigated. The results discussed are useful in understanding of low frequency electrostatic waves at laboratory pair ion plasmas.

Mushtaq, A. [Theoretical Plasma Physics Division, Pakistan Institute of Nuclear Science and Technology (PINSTECH), Nilore, Islamabad 45660 (Pakistan); School of Physics, University of Sydney, New South Wales 2006 (Australia); Saeed, R.; Haque, Q. [Theoretical Plasma Physics Division, Pakistan Institute of Nuclear Science and Technology (PINSTECH), Nilore, Islamabad 45660 (Pakistan)

2011-04-15T23:59:59.000Z

365

Forced Trench Waves  

Science Conference Proceedings (OSTI)

A general theory for forced barotropic long trench waves in the presence of linear bottom friction is presented. Two specific forcing mechanisms are considered: (i) transverse fluctuations in a western boundary current as it flows across a trench,...

Lawrence A. Mysak; Andrew J. Willmott

1981-11-01T23:59:59.000Z

366

Multiple spherically converging shock waves in liquid deuterium  

Science Conference Proceedings (OSTI)

To achieve ignition, inertial confinement fusion target designs use a sequence of shocks to compress the target before it implodes. To minimize the entropy acquired by the fuel, the strength and timing of these shocks will be precisely set during a series of tuning experiments that adjust the laser pulse to achieve optimal conditions. We report measurements of the velocity and timing of multiple, converging shock waves inside spherical targets filled with liquid (cryogenic) deuterium. These experiments produced the highest reported shock velocity observed in liquid deuterium (U{sub s} = 135 km/s at {approx}25 Mb) and observed an increase in shock velocity due to spherical convergence. These direct-drive experiments are best simulated when hydrodynamic codes use a nonlocal model for the transport of absorbed laser energy from the coronal plasma to the ablation surface.

Boehly, T. R.; Goncharov, V. N.; Seka, W.; Hu, S. X.; Marozas, J. A. [Laboratory for Laser Energetics, 250 East River Road, Rochester, New York 14423-1299 (United States); Meyerhofer, D. D. [Laboratory for Laser Energetics and Departments of Mechanical Engineering and Physics, University of Rochester, Rochester, New York 14627 (United States); Celliers, P. M.; Hicks, D. G.; Barrios, M. A.; Fratanduono, D.; Collins, G. W. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2011-09-15T23:59:59.000Z

367

Alfven Waves in the Lower Solar Atmosphere  

E-Print Network (OSTI)

We report the detection of oscillatory phenomena associated with a large bright-point group that is 430,000 square kilometers in area and located near the solar disk center. Wavelet analysis reveals full-width half-maximum oscillations with periodicities ranging from 126 to 700 seconds originating above the bright point and significance levels exceeding 99%. These oscillations, 2.6 kilometers per second in amplitude, are coupled with chromospheric line-of-sight Doppler velocities with an average blue shift of 23 kilometers per second. A lack of cospatial intensity oscillations and transversal displacements rules out the presence of magneto-acoustic wave modes. The oscillations are a signature of Alfven waves produced by a torsional twist of +/-22 degrees. A phase shift of 180 degrees across the diameter of the bright point suggests that these torsional Alfven oscillations are induced globally throughout the entire brightening. The energy flux associated with this wave mode is sufficient to heat the solar coro...

Jess, D B; Erdelyi, R; Crockett, P J; Keenan, F P; Christian, D J

2009-01-01T23:59:59.000Z

368

Standardization of the cumulative absolute velocity  

SciTech Connect

EPRI NP-5930, A Criterion for Determining Exceedance of the Operating Basis Earthquake,'' was published in July 1988. As defined in that report, the Operating Basis Earthquake (OBE) is exceeded when both a response spectrum parameter and a second damage parameter, referred to as the Cumulative Absolute Velocity (CAV), are exceeded. In the review process of the above report, it was noted that the calculation of CAV could be confounded by time history records of long duration containing low (nondamaging) acceleration. Therefore, it is necessary to standardize the method of calculating CAV to account for record length. This standardized methodology allows consistent comparisons between future CAV calculations and the adjusted CAV threshold value based upon applying the standardized methodology to the data set presented in EPRI NP-5930. The recommended method to standardize the CAV calculation is to window its calculation on a second-by-second basis for a given time history. If the absolute acceleration exceeds 0.025g at any time during each one second interval, the earthquake records used in EPRI NP-5930 have been reanalyzed and the adjusted threshold of damage for CAV was found to be 0.16g-set.

O'Hara, T.F.; Jacobson, J.P. (Yankee Atomic Electric Co., Bolton, MA (United States))

1991-12-01T23:59:59.000Z

369

Out-of-plane ultrasonic velocity measurement  

DOE Patents (OSTI)

A method for improving the accuracy of measuring the velocity and time of flight of ultrasonic signals through moving web-like materials such as paper, paperboard and the like, includes a pair of ultrasonic transducers disposed on opposing sides of a moving web-like material. In order to provide acoustical coupling between the transducers and the web-like material, the transducers are disposed in fluid-filled wheels. Errors due to variances in the wheel thicknesses about their circumference which can affect time of flight measurements and ultimately the mechanical property being tested are compensated by averaging the ultrasonic signals for a predetermined number of revolutions. The invention further includes a method for compensating for errors resulting from the digitization of the ultrasonic signals. More particularly, the invention includes a method for eliminating errors known as trigger jitter inherent with digitizing oscilloscopes used to digitize the signals for manipulation by a digital computer. In particular, rather than cross-correlate ultrasonic signals taken during different sample periods as is known in the art in order to determine the time of flight of the ultrasonic signal through the moving web, a pulse echo box is provided to enable cross-correlation of predetermined transmitted ultrasonic signals with predetermined reflected ultrasonic or echo signals during the sample period. By cross-correlating ultrasonic signals in the same sample period, the error associated with trigger jitter is eliminated.

Hall, Maclin S. (Marietta, GA); Brodeur, Pierre H. (Smyrna, GA); Jackson, Theodore G. (Atlanta, GA)

1998-01-01T23:59:59.000Z

370

Out-of-plane ultrasonic velocity measurement  

DOE Patents (OSTI)

A method for improving the accuracy of measuring the velocity and time of flight of ultrasonic signals through moving web-like materials such as paper, paperboard and the like, includes a pair of ultrasonic transducers disposed on opposing sides of a moving web-like material. In order to provide acoustical coupling between the transducers and the web-like material, the transducers are disposed in fluid-filled wheels. Errors due to variances in the wheel thicknesses about their circumference which can affect time of flight measurements and ultimately the mechanical property being tested are compensated by averaging the ultrasonic signals for a predetermined number of revolutions. The invention further includes a method for compensating for errors resulting from the digitization of the ultrasonic signals. More particularly, the invention includes a method for eliminating errors known as trigger jitter inherent with digitizing oscilloscopes used to digitize the signals for manipulation by a digital computer. In particular, rather than cross-correlate ultrasonic signals taken during different sample periods as is known in the art in order to determine the time of flight of the ultrasonic signal through the moving web, a pulse echo box is provided to enable cross-correlation of predetermined transmitted ultrasonic signals with predetermined reflected ultrasonic or echo signals during the sample period. By cross-correlating ultrasonic signals in the same sample period, the error associated with trigger jitter is eliminated. 20 figs.

Hall, M.S.; Brodeur, P.H.; Jackson, T.G.

1998-07-14T23:59:59.000Z

371

A Hypothetical Burning-Velocity Formula for Very Lean Hydrogen-Air Mixtures  

E-Print Network (OSTI)

K. Fig. 2 Comparisons of burning-velocity predictions withcurve), when an experimental burning velocity (points) of 53and calculated laminar burning velocities of lean hydrogen-

Grcar, Joseph F

2008-01-01T23:59:59.000Z

372

Polarizer reflectivity variations  

SciTech Connect

On Shiva the beam energy along the chain is monitored using available reflections and/or transmission through beam steering, splitting, and polarizing optics without the intrusion of any additional glass for diagnostics. On the preamp table the diagnostic signal is obtained from the signal transmitted through turning mirrors. At the input of each chain the signal is obtained from the transmission through one of the mirrors used for the chain input alignment sensor (CHIP). At the chain output the transmission through the final turning mirror is used. These diagnostics have proved stable and reliable. However, one of the prime diagnostic locations is at the output of the beta rod. The energy at this location is measured by collecting small reflections from the last polarizer surface of the beta Pockels cell polarizer package. Unfortunately, calibration of this diagnostic has varied randomly, seldom remaining stable for a week or more. The cause of this fluctuation has been investigated for the past year and'it has been discovered that polarizer reflectivity varies with humidity. This report will deal with the possible causes that were investigated, the evidence that humidity is causing the variation, and the associated mechanism.

Ozarski, R.G.; Prior, J.

1980-02-22T23:59:59.000Z

373

MHK Technologies/GyroWaveGen | Open Energy Information  

Open Energy Info (EERE)

GyroWaveGen GyroWaveGen < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage GyroWaveGen.jpg Technology Profile Primary Organization Paradyme Systems Technology Type Click here Oscillating Wave Surge Converter Technology Readiness Level Click here TRL 5 6 System Integration and Technology Laboratory Demonstration Technology Description A gyro wave energy transducer is mounted on the buoyant body for translating the pendulum like motions of the buoyant body into rotational motion The gyro wave energy transducer includes a gimbal comprised of first and second frames with the first frame being pivotally mounted to the second frame and the second frame being pivotally mounted to the buoyant body A gyroscope is mounted to the first frame for rotation about an axis perpendicular to the axes of rotation of the first and second frames A motor generator is coupled to the gyroscope for maintaining a controlled rotational velocity for the gyroscope Transferring members are associated with one of the first and second frames for transferring torque of one of the first and second frames to the gyroscope about an axis that is perpendicular to that of the gyroscope which results in rotation of the other of the first and second frames An electrical generator is responsive to the relative rotational movement of the first and se

374

ENERGY CONTENT AND PROPAGATION IN TRANSVERSE SOLAR ATMOSPHERIC WAVES  

SciTech Connect

Recently, a significant amount of transverse wave energy has been estimated propagating along solar atmospheric magnetic fields. However, these estimates have been made with the classic bulk Alfven wave model which assumes a homogeneous plasma. In this paper, the kinetic, magnetic, and total energy densities and the flux of energy are computed for transverse MHD waves in one-dimensional cylindrical flux tube models with a piecewise constant or continuous radial density profile. There are fundamental deviations from the properties for classic bulk Alfven waves. (1) There is no local equipartition between kinetic and magnetic energy. (2) The flux of energy and the velocity of energy transfer have, in addition to a component parallel to the magnetic field, components in the planes normal to the magnetic field. (3) The energy densities and the flux of energy vary spatially, contrary to the case of classic bulk Alfven waves. This last property has the important consequence that the energy flux computed with the well known expression for bulk Alfven waves could overestimate the real flux by a factor in the range 10-50, depending on the flux tube equilibrium properties.

Goossens, M.; Van Doorsselaere, T. [Centre for mathematical Plasma Astrophysics, Mathematics Department, Celestijnenlaan 200B bus 2400, B-3001 Heverlee (Belgium); Soler, R. [Solar Physics Group, Departament de Fisica, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain); Verth, G., E-mail: tom.vandoorsselaere@wis.kuleuven.be [Solar Physics and Space Plasma Research Centre (SP2RC), School of Mathematics and Statistics, University of Sheffield, Hounsfield Road, Hicks Building, Sheffield S3 7RH (United Kingdom)

2013-05-10T23:59:59.000Z

375

Single crystal metal wedges for surface acoustic wave propagation  

DOE Patents (OSTI)

An ultrasonic testing device has been developed to evaluate flaws and inhomogeneities in the near-surface region of a test material. A metal single crystal wedge is used to generate high frequency Rayleigh surface waves in the test material surface by conversion of a slow velocity, bulk acoustic mode in the wedge into a Rayleigh wave at the metal-wedge test material interface. Particular classes of metals have been found to provide the bulk acoustic modes necessary for production of a surface wave with extremely high frequency and angular collimation. The high frequency allows flaws and inhomogeneities to be examined with greater resolution. The high degree of angular collimation for the outgoing ultrasonic beam permits precision angular location of flaws and inhomogeneities in the test material surface.

Fisher, E.S.

1980-05-09T23:59:59.000Z

376

Single crystal metal wedges for surface acoustic wave propagation  

DOE Patents (OSTI)

An ultrasonic testing device has been developed to evaluate flaws and inhomogeneities in the near-surface region of a test material. A metal single crystal wedge is used to generate high frequency Rayleigh surface waves in the test material surface by conversion of a slow velocity, bulk acoustic mode in the wedge into a Rayleigh wave at the metal-wedge test material interface. Particular classes of metals have been found to provide the bulk acoustic modes necessary for production of a surface wave with extremely high frequency and angular collimation. The high frequency allows flaws and inhomogeneities to be examined with greater resolution. The high degree of angular collimation for the outgoing ultrasonic beam permits precision angular location of flaws and inhomogeneities in the test material surface.

Fisher, Edward S. (Wheaton, IL)

1982-01-01T23:59:59.000Z

377

AnisWave2D: User's Guide to the 2d Anisotropic Finite-DifferenceCode  

Science Conference Proceedings (OSTI)

This document describes a parallel finite-difference code for modeling wave propagation in 2D, fully anisotropic materials. The code utilizes a mesh refinement scheme to improve computational efficiency. Mesh refinement allows the grid spacing to be tailored to the velocity model, so that fine grid spacing can be used in low velocity zones where the seismic wavelength is short, and coarse grid spacing can be used in zones with higher material velocities. Over-sampling of the seismic wavefield in high velocity zones is therefore avoided. The code has been implemented to run in parallel over multiple processors and allows large-scale models and models with large velocity contrasts to be simulated with ease.

Toomey, Aoife

2005-01-06T23:59:59.000Z

378

Simultaneous Measurements of Drop Size and Velocity in ...  

Science Conference Proceedings (OSTI)

... of entrained air velocity. An example is presented in Prahl and Wendt (1988) and Wendt and Prahl (1986) where the authors ...

379

Modified definition of group velocity and electromagnetic energy conservation equation  

E-Print Network (OSTI)

The classical definition of group velocity has two flaws: (a) the group velocity can be greater than the phase velocity in a non-dispersive medium; (b) the definition is not consistent with the principle of relativity. To remove the flaws, a modified definition is proposed. A criterion is set up to identify the justification of group velocity definition. A "superluminal power flow" is constructed to show that the electromagnetic energy conservation equation cannot uniquely define the power flow if the principle of Fermat is not taken into account.

Changbiao Wang

2013-06-13T23:59:59.000Z

380

New Insights Into Deep Convective Core Vertical Velocities Using...  

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

Insights Into Deep Convective Core Vertical Velocities Using ARM UHF Wind Profilers For original submission and image(s), see ARM Research Highlights http:www.arm.govscience...

Note: This page contains sample records for the topic "wave velocity variations" 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

Detecting Source Regions of Wave Activities in the Tropical Atmosphere by Applying Beamforming to Interpolated Data Grids  

Science Conference Proceedings (OSTI)

Wave activities are primary sources of weather disturbances and cyclones in the tropical atmosphere. One such activity is the intraseasonal variations in wind, convection, and precipitation in the tropical Indian and western tropical Pacific ...

Qi Hu; Zhaoning Liang; Michael W. Hoffman

2009-02-01T23:59:59.000Z

382

Standing wave compressor  

DOE Green Energy (OSTI)

A compressor for compression-evaporation cooling systems, which requires no moving parts. A gaseous refrigerant inside a chamber is acoustically compressed and conveyed by means of a standing acoustic wave which is set up in the gaseous refrigerant. This standing acoustic wave can be driven either by a transducer, or by direct exposure of the gas to microwave and infrared sources, including solar energy. Input and output ports arranged along the chamber provide for the intake and discharge of the gaseous refrigerant. These ports can be provided with optional valve arrangements, so as to increase the compressor's pressure differential. The performance of the compressor in either of its transducer or electromagnetically driven configurations, can be optimized by a controlling circuit. This controlling circuit holds the wavelength of the standing acoustical wave constant, by changing the driving frequency in response to varying operating conditions.

Lucas, Timothy S. (4614 River Mill Ct., Glen Allen, VA 23060)

1991-01-01T23:59:59.000Z

383

Standing wave compressor  

DOE Patents (OSTI)

A compressor for compression-evaporation cooling systems, which requires no moving parts. A gaseous refrigerant inside a chamber is acoustically compressed and conveyed by means of a standing acoustic wave which is set up in the gaseous refrigerant. This standing acoustic wave can be driven either by a transducer, or by direct exposure of the gas to microwave and infrared sources, including solar energy. Input and output ports arranged along the chamber provide for the intake and discharge of the gaseous refrigerant. These ports can be provided with optional valve arrangements, so as to increase the compressor's pressure differential. The performance of the compressor in either of its transducer or electromagnetically driven configurations, can be optimized by a controlling circuit. This controlling circuit holds the wavelength of the standing acoustical wave constant, by changing the driving frequency in response to varying operating conditions.

Lucas, Timothy S. (4614 River Mill Ct., Glen Allen, VA 23060)

1991-01-01T23:59:59.000Z

384

Piezoelectric wave motor  

DOE Patents (OSTI)

A piezoelectric motor having a stator in which piezoelectric elements are contained in slots formed in the stator transverse to the desired wave motion. When an electric field is imposed on the elements, deformation of the elements imposes a force perpendicular to the sides of the slot, deforming the stator. Appropriate frequency and phase shifting of the electric field will produce a wave in the stator and motion in a rotor. In a preferred aspect, the piezoelectric elements are configured so that deformation of the elements in direction of an imposed electric field, generally referred to as the d.sub.33 direction, is utilized to produce wave motion in the stator. In a further aspect, the elements are compressed into the slots so as to minimize tensile stresses on the elements in use.

Yerganian, Simon Scott (Lee' s Summit, MO)

2001-07-17T23:59:59.000Z

385

Piezoelectric wave motor  

DOE Patents (OSTI)

A piezoelectric motor having a stator in which piezoelectric elements are contained in slots formed in the stator transverse to the desired wave motion. When an electric field is imposed on the elements, deformation of the elements imposes a force perpendicular to the sides of the slot, deforming the stator. Appropriate frequency and phase-shifting of the electric field will produce a wave in the stator and motion in a rotor. In a preferred aspect, the piezoelectric elements are configured so that deformation of the elements in the direction of an imposed electric field, generally referred to as the d.sub.33 direction, is utilized to produce wave motion in the stator. In a further aspect, the elements are compressed into the slots so as to minimize tensile stresses on the elements in use.

Yerganian, Simon Scott (Lee' s Summit, MO)

2003-02-11T23:59:59.000Z

386

TIMING OF SHOCK WAVES  

DOE Patents (OSTI)

This patent relates to means for ascertaining the instant of arrival of a shock wave in an exploslve charge and apparatus utilizing this means to coordinate the timing of two operations involving a short lnterval of time. A pair of spaced electrodes are inserted along the line of an explosive train with a voltage applied there-across which is insufficient to cause discharge. When it is desired to initiate operation of a device at the time the explosive shock wave reaches a particular point on the explosive line, the device having an inherent time delay, the electrodes are located ahead of the point such that the ionization of the area between the electrodes caused by the traveling explosive shock wave sends a signal to initiate operation of the device to cause it to operate at the proper time. The operated device may be photographic equipment consisting of an x-ray illuminating tube.

Tuck, J.L.

1955-03-01T23:59:59.000Z

387

The stability and the growth rate of the electron acoustic traveling wave under transverse perturbations in a magnetized quantum plasma  

Science Conference Proceedings (OSTI)

Theoretical and numerical studies are carried out for the stability of the electron acoustic waves under the transverse perturbation in a magnetized quantum plasma. The Zakharov-Kuznetsov (ZK) equation of the electron-acoustic waves (EAWs) is given by using the reductive perturbation technique. The cut-off frequency is obtained by applying a transverse sinusoidal perturbation to the plane soliton solution of the ZK equation. The propagation velocity of solitary waves, the real cut-off frequency, as well as the growth rate of the higher order perturbation to the traveling solitary wave are obtained.

Gao Dongning; Wang Canglong; Yang Xue; Duan Wenshan [College of Physics and Electronic Engineering and Joint Laboratory of Atomic and Molecular Physics of NWNU and IMP CAS, Northwest Normal University, Lanzhou, 730070 (China) and Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Yang Lei [College of Physics and Electronic Engineering and Joint Laboratory of Atomic and Molecular Physics of NWNU and IMP CAS, Northwest Normal University, Lanzhou, 730070 (China) and Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Department of Physics, Lanzhou University, Lanzhou 730000 (China)

2012-12-15T23:59:59.000Z

388

Ion beam driven ion-acoustic waves in a plasma cylinder with negatively charged dust grains  

SciTech Connect

An ion beam propagating through a magnetized potassium plasma cylinder having negatively charged dust grains drives electrostatic ion-acoustic waves to instability via Cerenkov interaction. The phase velocity of sound wave increases with the relative density of negatively charged dust grains. The unstable wave frequencies and the growth rate increase, with the relative density of negatively charged dust grains. The growth rate of the unstable mode scales as one-third power of the beam density. The real part of frequency of the unstable mode increases with the beam energy and scales as almost the one-half power of the beam energy.

Sharma, Suresh C.; Walia, Ritu [Department of Physics, Maharaja Agrasen Institute of Technology, PSP Area Plot No.-1, Sector-22, Rohini, Delhi 110 086 (India); Sharma, Kavita [Department of Physics, Bhagwan Parshuram Institute of Technology, Sector-17, Rohini, New Delhi 110 089 (India)

2012-07-15T23:59:59.000Z

389

Expanding impulsive gravitational waves  

E-Print Network (OSTI)

We explicitly demonstrate that the known solutions for expanding impulsive spherical gravitational waves that have been obtained by a "cut and paste" method may be considered to be impulsive limits of the Robinson-Trautman vacuum type N solutions. We extend these results to all the generically distinct subclasses of these solutions in Minkowski, de Sitter and anti-de Sitter backgrounds. For these we express the solutions in terms of a continuous metric. Finally, we also extend the class of spherical shock gravitational waves to include a non-zero cosmological constant.

J. Podolsky; J. B. Griffiths

1999-07-06T23:59:59.000Z

390

Ultrasonic shear wave couplant  

DOE Patents (OSTI)

Ultrasonically testing of an article at high temperatures is accomplished by the use of a compact layer of a dry ceramic powder as a couplant in a method which involves providing an ultrasonic transducer as a probe capable of transmitting shear waves, coupling the probe to the article through a thin compact layer of a dry ceramic powder, propagating a shear wave from the probe through the ceramic powder and into the article to develop echo signals, and analyzing the echo signals to determine at least one physical characteristic of the article.

Kupperman, David S. (Oak Park, IL); Lanham, Ronald N. (Lockport, IL)

1985-01-01T23:59:59.000Z

391

Ultrasonic shear wave couplant  

DOE Patents (OSTI)

Ultrasonically testing of an article at high temperatures is accomplished by the use of a compact layer of a dry ceramic powder as a couplant in a method which involves providing an ultrasonic transducer as a probe capable of transmitting shear waves, coupling the probe to the article through a thin compact layer of a dry ceramic powder, propagating a shear wave from the probe through the ceramic powder and into the article to develop echo signals, and analyzing the echo signals to determine at least one physical characteristic of the article.

Kupperman, D.S.; Lanham, R.N.

1984-04-11T23:59:59.000Z

392

Solar off-limb line widths: Alfven waves, ion-cyclotron waves, and preferential heating  

E-Print Network (OSTI)

Alfven waves and ion-cyclotron absorption of high-frequency waves are frequently brought into models devoted to coronal heating and fast solar-wind acceleration. Signatures of ion-cyclotron resonance have already been observed in situ in the solar wind (HELIOS spacecrafts) and, recently, in the upper corona (UVCS/SOHO remote-sensing results). We propose a method to constrain both the Alfven wave amplitude and the preferential heating induced by ion-cyclotron resonance, above a partially developed polar coronal hole observed with the SUMER/SOHO spectrometer. The instrumental stray light contribution is first substracted from the spectra. By supposing that the non-thermal velocity is related to the Alfven wave amplitude, it is constrained through a density diagnostic and the gradient of the width of the Mg X 625 A line. The temperatures of several coronal ions, as functions of the distance above the limb, are then determined by substracting the non-thermal component to the observed line widths. The effect of stray light explains the apparent decrease with height in the width of several spectral lines, this decrease usually starting about 0.1-0.2 Rs above the limb. This result rules out any direct evidence of damping of the Alfven waves, often suggested by other authors. We also find that the ions with the smallest charge-to-mass ratios are the hottest ones at a fixed altitude and that they are subject to a stronger heating, as compared to the others, between 57" and 102" above the limb. This constitutes a serious clue to ion-cyclotron preferential heating.

L. Dolla; J. Solomon

2008-04-18T23:59:59.000Z

393

Annual Cycle and Depth Penetration of Wind-Generated Near-Inertial Internal Waves at Ocean Station Papa in the Northeast Pacific  

Science Conference Proceedings (OSTI)

The downward propagation of near-inertial internal waves following winter storms is examined in the context of a 2-yr record of velocity in the upper 800 m at Ocean Station Papa. The long time series allow accurate estimation of wave frequency, ...

Matthew H. Alford; Meghan F. Cronin; Jody M. Klymak

2012-06-01T23:59:59.000Z

394

Kinetic Alfven Waves at the Magnetopause--Mode Conversion, Transport and Formation of LLBL  

DOE Green Energy (OSTI)

At the magnetopause, large amplitude, low-frequency (ULF), transverse MHD waves are nearly always observed. These waves likely result from mode conversion of compressional MHD waves observed in the magnetosheath to kinetic Alfven waves at the magnetopause where there is a steep gradient in the Alfven velocity [Johnson and Cheng, Geophys. Res. Lett. 24 (1997) 1423]. The mode-conversion process can explain the following wave observations typically found during satellite crossings of the magnetopause: (1) a dramatic change in wave polarization from compressional in the magnetosheath to transverse at the magnetopause, (2) an amplification of wave amplitude at the magnetopause, (3) a change in Poynting flux from cross-field in the magnetosheath to field-aligned at the magnetopause, and (4) a steepening in the wave power spectrum at the magnetopause. We examine magnetic field data from a set of ISEE1, ISEE2, and WIND magnetopause crossings and compare with the predictions of theoretical wave solutions based on the kinetic-fluid model with particular attention to the role of magnetic field rotation across the magnetopause. The results of the study suggest a good qualitative agreement between the observations and the theory of mode conversion to kinetic Alfven waves. Because mode-converted kinetic Alfven waves readily decouple particles from the magnetic field lines, efficient quasilinear transport (D {approx} 109m2/s) can occur. Moreover, if the wave amplitude is sufficiently large (Bwave/B0 > 0.2) stochastic particle transport also occurs. This wave-induced transport can lead to significant heating and particle entry into the low latitude boundary layer across closed field lines.At the magnetopause, large amplitude, low-frequency (ULF), transverse MHD waves are nearly always observed. These waves likely result from mode conversion of compressional MHD waves observed in the magnetosheath to kinetic Alfven waves at the magnetopause where there is a steep gradient in the Alfven velocity [Johnson and Cheng, Geophys. Res. Lett. 24 (1997) 1423]. The mode-conversion process can explain the following wave observations typically found during satellite crossings of the magnetopause: (1) a dramatic change in wave polarization from compressional in the magnetosheath to transverse at the magnetopause, (2) an amplification of wave amplitude at the magnetopause, (3) a change in Poynting flux from cross-field in the magnetosheath to field-aligned at the magnetopause, and (4) a steepening in the wave power spectrum at the magnetopause. We examine magnetic field data from a set of ISEE1, ISEE2, and WIND magnetopause crossings and compare with the predictions of theoretical wave solutions based on the kinetic-fluid model with particular attention to the role of magnetic field rotation across the magnetopause. The results of the study suggest a good qualitative agreement between the observations and the theory of mode conversion to kinetic Alfven waves. Because mode-converted kinetic Alfven waves readily decouple particles from the magnetic field lines, efficient quasilinear transport (D {approx} 10{sup 9}m{sup 2}/s) can occur. Moreover, if the wave amplitude is sufficiently large (B{sub wave}/B{sub 0} > 0.2) stochastic particle transport also occurs. This wave-induced transport can lead to significant heating and particle entry into the low latitude boundary layer across closed field lines.

Jay R. Johnson; C.Z. Cheng

2002-05-31T23:59:59.000Z

395

Measurements of Laminar Flame Velocity for Components of Natural Gas  

E-Print Network (OSTI)

Measurements of Laminar Flame Velocity for Components of Natural Gas Patricia Dirrenberger1 flame velocity of components of natural gas, methane, ethane, propane, and nbutane as well as of binary and tertiary mixtures of these compounds proposed as surrogates for natural gas. These measurements have been

396

Wave refraction in left-handed materials  

E-Print Network (OSTI)

We examine the response of a plane wave incident on a flat surface of a medium characterized by simultaneously negative electric and magnetic susceptibilities by solving Maxwell's equations explicitly and without making any assumptions on the way. In the literature up to date, it has been assumed that negative refractive materials are necessarily frequency dispersive. We propose an alternative to this assumption by suggesting that the requirement of positive energy density should be relaxed, and discuss the implications of such a proposal. More specifically, we show that once negative energy solutions are accepted, the necessity for frequency dispersion is no longer necessary. Finally, we argue that, for the purposes of discussing negative index materials, the use of group velocity as the physically significant quantity is misleading, and suggest that any discussion involving it should be carefully reconsidered.

Chimonidou, Antonia

2008-01-01T23:59:59.000Z

397

Dirac fermion wave guide networks on topological insulator surfaces  

E-Print Network (OSTI)

Magnetic texturing on the surface of a topological insulator allows the design of wave guide networks and beam splitters for domain-wall Dirac fermions. Guided by simple analytic arguments we model a Dirac fermion interferometer consisting of two parallel pathways, whereby a newly developed staggered-grid leap-frog discretization scheme in 2+1 dimensions with absorbing boundary conditions is employed. The net transmission can be tuned between constructive to destructive interference, either by variation of the magnetization (path length) or an applied bias (wave length). Based on this principle, a Dirac fermion transistor is proposed. Extensions to more general networks are discussed.

René Hammer; Christian Ertler; Walter Pötz

2012-05-31T23:59:59.000Z

398

Dust Acoustic Shock Waves in Adiabatic Hot Dusty Plasmas  

Science Conference Proceedings (OSTI)

It is known that to have a monotonic or oscillatory shock wave a source of dissipation is needed. In this study, we considered the dust charge variation as a source of dissipation. By using the reductive perturbation technique, the nonlinear Burgers equation is derived and the shock-like solution is determined. The effects of dust temperature on different characteristics of dust acoustic shock wave are discussed. It is found out that dust thickness is not affected by dust temperature while for every dusty plasma systems there is dust critical temperature T{sub dc}, for which the dust acoustic shock height will be maximum.

Asgari, H.; Muniandy, S. V.; Wong, C. S. [Plasma Research Laboratory, Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2011-03-30T23:59:59.000Z

399

Wave–Turbulence Interactions in a Breaking Mountain Wave  

Science Conference Proceedings (OSTI)

The mean and turbulent structures in a breaking mountain wave are considered through an ensemble of high-resolution (essentially large-eddy simulation) wave-breaking calculations. Of particular interest are the turbulent heat and momentum fluxes ...

Craig C. Epifanio; Tingting Qian

2008-10-01T23:59:59.000Z

400

Effects of Long Waves on Wind-Generated Waves  

Science Conference Proceedings (OSTI)

A model is developed to explain the observation made in several laboratory experiments that short wind-generated waves are suppressed by a train of long, mechanically generated waves. A sheltering mechanism is responsible for generation of the ...

Gang Chen; Stephen E. Belcher

2000-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "wave velocity variations" 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

Mass Flux and Vertical Distribution of Currents Caused by Strong Winds in a Wave Tank  

Science Conference Proceedings (OSTI)

The velocity fields of wind-driven currents under strong winds were measured in a wind-wave tank with a double bottom. The tank has the characteristics to satisfy partially the continuity of the mass flux and to reduce return-flow effects on the ...

Toshinori Ogasawara; Takashi Yasuda

2004-12-01T23:59:59.000Z

402

Changes in fluctuation waves in coherent airflow structures with input perturbation  

Science Conference Proceedings (OSTI)

We predict the development and propagation of the fluctuations in a perturbed ideally-expanded air jet. A non-propagating harmonic perturbation in the density, axial velocity, and pressure is introduced at the inflow with different frequencies to produce ... Keywords: acoustic, air, coherent, fluctuation, jet, perturbation, synchronized, waves

Osama A. Marzouk

2008-10-01T23:59:59.000Z

403

Measurement of Ocean Wave Directional Spectra Using Doppler Side-Scan Sonar Arrays  

Science Conference Proceedings (OSTI)

A technique is presented for extraction of ocean wave directional spectra using Doppler side-scan sonars. Two 103-kHz steerable side-scan beams from a freely drifting subsurface platform are used to estimate horizontal water surface velocity due ...

Mark V. Trevorrow

1995-06-01T23:59:59.000Z

404

An Experimental Study of Baroclinic Flows with and without Two-Wave Bottom Topography  

Science Conference Proceedings (OSTI)

A series of laboratory experiments was performed in a thermally-driven rotating annulus of fluid with and without two-wave bottom topography. Velocity measurements were made by illuminating a thin layer of fluid at mid-depth and photographing ...

Guo-Qing Li; Robin Kung; Richard L. Pfeffer

1986-11-01T23:59:59.000Z

405

Multiple mapping conditioning of velocity in turbulent jet flames  

Science Conference Proceedings (OSTI)

Multiple mapping conditioning (MMC) has emerged as a new approach to model turbulent reacting flows. This study revises the standard MMC closure for velocity in turbulent jet flows from linearity in the reference space to linearity in the composition space. This modeling amendment ensures that the standard velocity model in conditional moment closure studies can now be used for MMC computation as well. A simplified model for the velocity-dependence of MMC drift coefficients is derived without loss of generality and is implemented for the revised velocity closure. Modeling results have been corroborated against the Direct Numerical Simulation database of a spatially evolving, planar turbulent jet flame. The revised model shows marked improvement over standard MMC closure in predicting velocity statistics close to the nozzle. (author)

Vaishnavi, P. [Mechanical Engineering Department, Imperial College, London SW7 2AZ (United Kingdom); Kronenburg, A. [Institut fuer Technische Verbrennung, Universitaet Stuttgart, 70174 Stuttgart (Germany)

2010-10-15T23:59:59.000Z

406

Pulsed wave interconnect  

Science Conference Proceedings (OSTI)

Pulsed wave interconnect is proposed for global interconnect applications. Signals are represented by localized wavepackets that propagate along the interconnect lines at the local speed of light to trigger the receivers. Energy consumption is reduced ... Keywords: CMOS, VLSI, high-speed interconnect, nonlinear transmission line, pulse compression, soliton, wafer-scale-integration

Pingshan Wang; Gen Pei; Edwin Chih-Chuan Kan

2004-05-01T23:59:59.000Z

407

Deflagration Wave Profiles  

SciTech Connect

Shock initiation in a plastic-bonded explosives (PBX) is due to hot spots. Current reactive burn models are based, at least heuristically, on the ignition and growth concept. The ignition phase occurs when a small localized region of high temperature (or hot spot) burns on a fast time scale. This is followed by a growth phase in which a reactive front spreads out from the hot spot. Propagating reactive fronts are deflagration waves. A key question is the deflagration speed in a PBX compressed and heated by a shock wave that generated the hot spot. Here, the ODEs for a steady deflagration wave profile in a compressible fluid are derived, along with the needed thermodynamic quantities of realistic equations of state corresponding to the reactants and products of a PBX. The properties of the wave profile equations are analyzed and an algorithm is derived for computing the deflagration speed. As an illustrative example, the algorithm is applied to compute the deflagration speed in shock compressed PBX 9501 as a function of shock pressure. The calculated deflagration speed, even at the CJ pressure, is low compared to the detonation speed. The implication of this are briefly discussed.

Menikoff, Ralph [Los Alamos National Laboratory

2012-04-03T23:59:59.000Z

408

Water Waves and Integrability  

E-Print Network (OSTI)

The Euler's equations describe the motion of inviscid fluid. In the case of shallow water, when a perturbative asymtotic expansion of the Euler's equations is taken (to a certain order of smallness of the scale parameters), relations to certain integrable equations emerge. Some recent results concerning the use of integrable equation in modeling the motion of shallow water waves are reviewed in this contribution.

Rossen I. Ivanov

2007-07-12T23:59:59.000Z

409

A case for variational geomagnetic data assimilation: insights from a one-dimensional, nonlinear, and sparsely observed MHD system  

E-Print Network (OSTI)

Secular variations of the geomagnetic field have been measured with a continuously improving accuracy during the last few hundred years, culminating nowadays with satellite data. It is however well known that the dynamics of the magnetic field is linked to that of the velocity field in the core and any attempt to model secular variations will involve a coupled dynamical system for magnetic field and core velocity. Unfortunately, there is no direct observation of the velocity. Independently of the exact nature of the above-mentioned coupled system -- some version being currently under construction -- the question is debated in this paper whether good knowledge of the magnetic field can be translated into good knowledge of core dynamics. Furthermore, what will be the impact of the most recent and precise geomagnetic data on our knowledge of the geomagnetic field of the past and future? These questions are cast into the language of variational data assimilation, while the dynamical system considered in this pape...

Fournier, Alexandre; Alboussière, Thierry

2007-01-01T23:59:59.000Z

410

Evolution of a Random Directional Wave and Freak Wave Occurrence  

Science Conference Proceedings (OSTI)

The evolution of a random directional wave in deep water was studied in a laboratory wave tank (50 m long, 10 m wide, 5 m deep) utilizing a directional wave generator. A number of experiments were conducted, changing the various spectral ...

Takuji Waseda; Takeshi Kinoshita; Hitoshi Tamura

2009-03-01T23:59:59.000Z

411

Distinguishing Propagating Waves and Standing Modes: An Internal Wave Model  

Science Conference Proceedings (OSTI)

This paper examines high-frequency (0.1-0.5 cph) internal waves, waves previously characterized by the Garrett and Munk spectral fits (GM72, GM75, GM79) as being vertically symmetric propagating waves (or equivalently “smeared” standing modes—...

M. Benno Blumenthal; Melbourne G. Briscoe

1995-06-01T23:59:59.000Z

412

Wave Activity Diagnostics Applied to Baroclinic Wave Life Cycles  

Science Conference Proceedings (OSTI)

Wave activity diagnostics are calculated for four different baroclinic wave life cycles, including the LC1 and LC2 cases studied by Thorncroft, Hoskins, and McIntyre. The wave activity is a measure of the disturbance relative to some zonally ...

Gudrun Magnusdottir; Peter H. Haynes

1996-08-01T23:59:59.000Z

413

Wave Breaking Dissipation in the Wave-Driven Ocean Circulation  

Science Conference Proceedings (OSTI)

If wave breaking modifies the Lagrangian fluid paths by inducing an uncertainty in the orbit itself and this uncertainty on wave motion time scales is observable as additive noise, it is shown that within the context of a wave–current interaction ...

Juan M. Restrepo

2007-07-01T23:59:59.000Z

414

Numerical Dispersion of Gravity Waves  

Science Conference Proceedings (OSTI)

When atmospheric gravity waves are simulated in numerical models, they are not only dispersive for physical but also for numerical reasons. Their wave properties (e.g., damping or propagation speed and direction) can depend on grid spacing as ...

Guido Schroeder; K. Heinke Schlünzen

2009-12-01T23:59:59.000Z

415

Sodium Nightglow and Gravity Waves  

Science Conference Proceedings (OSTI)

Oscillations in intensity of NaD nightglow attributed to mesospheric gravity waves have bean studied. Fractional atmospheric density perturbations have been obtained by means of the linear gravity waves theory of Hines. Values of other parameters ...

A. Molina

1983-10-01T23:59:59.000Z

416

Diffusive Transport by Breaking Waves  

Science Conference Proceedings (OSTI)

A simple conceptual model of the relationship between advective transport by breaking waves and diffusive transport is derived. line model postulates that the displacement of fluid parcels by a breaking wave is analogous to molecular diffusion (...

Kenneth P. Bowman

1995-07-01T23:59:59.000Z

417

Kinetic Theory of Plasma Waves  

Science Conference Proceedings (OSTI)

Kinetic Wave Theory / Proceedings of the Tenth Carolus Magnus Summer School on Plasma and Fusion Energy Physics

D. Van Eester; E. Lerche

418

Gravitational waves and fundamental physics  

E-Print Network (OSTI)

I give an overview of the motivations for gravitational-wave research, concentrating on the aspects related to ``fundamental'' physics.

Michele Maggiore

2006-02-15T23:59:59.000Z

419

Gravitational Wave Sources: An Overview  

Science Conference Proceedings (OSTI)

With full?sensitivity operation of the first generation of gravitational wave detectors now just around the corner

Bernard F. Schutz

2003-01-01T23:59:59.000Z

420

Energy Loss by Breaking waves  

Science Conference Proceedings (OSTI)

Observations of the frequency of wind wave breaking in deep water are combined with laboratory estimates of the rate of energy loss a from single breaking wave to infer the net rate of energy transfer to the mixed layer from breaking waves, as a ...

S. A. Thorpe

1993-11-01T23:59:59.000Z

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


421

Modification of Proton Velocity Distributions by Alfvenic Turbulence in the Solar Wind  

E-Print Network (OSTI)

In the present paper, the proton velocity distribution function (VDF)in the solar wind is determined by solving numerically the kinetic evolution equation. We compare the results obtained when considering the effects of ex- ternal forces and Coulomb collisions with those obtained by adding effects of Alfven wave turbulence. We use Fokker-Planck diffusion terms due to Alfvenic turbulence, which take into account observed turbulence spectra and kinetic effects of finite proton gyroradius. Assuming a displaced Maxwellian for the proton VDF at the simulation boundary at 14 solar radii, we show that the turbulence leads to a fast (within several solar radii) development of the anti-sunward tail in the proton VDF. Our results provide a natural explanation for the nonthermal tails in the proton VDFs, which are often observed in-situ in the solar wind beyond 0.3 AU.

Pierrard, Viviane

2013-01-01T23:59:59.000Z

422

Shock waves in strongly coupled plasmas  

E-Print Network (OSTI)

Shock waves are supersonic disturbances propagating in a fluid and giving rise to dissipation and drag. Weak shocks, i.e., those of small amplitude, can be well described within the hydrodynamic approximation. On the other hand, strong shocks are discontinuous within hydrodynamics and therefore probe the microscopics of the theory. In this paper we consider the case of the strongly coupled N=4 plasma whose microscopic description, applicable for scales smaller than the inverse temperature, is given in terms of gravity in an asymptotically $AdS_5$ space. In the gravity approximation, weak and strong shocks should be described by smooth metrics with no discontinuities. For weak shocks we find the dual metric in a derivative expansion and for strong shocks we use linearized gravity to find the exponential tail that determines the width of the shock. In particular we find that, when the velocity of the fluid relative to the shock approaches the speed of light $v\\to 1$ the penetration depth $\\ell$ scales as $\\ell\\sim (1-v^2)^{1/4}$. We compare the results with second order hydrodynamics and the Israel-Stewart approximation. Although they all agree in the hydrodynamic regime of weak shocks, we show that there is not even qualitative agreement for strong shocks. For the gravity side, the existence of shock waves implies that there are disturbances of constant shape propagating on the horizon of the dual black holes.

Sergei Khlebnikov; Martin Kruczenski; Georgios Michalogiorgakis

2010-04-21T23:59:59.000Z

423

Shock waves in strongly coupled plasmas II  

E-Print Network (OSTI)

In a recent paper we have analyzed the AdS/CFT duals to shock waves propagating in the N=4 plasma. Here we study further properties of the system. In the gravity description we consider the properties of the dual black holes, showing in particular that they are stationary black holes with expanding horizons. This is possible because the horizon is not compact; in the fluid, this corresponds to the situation when entropy is being produced and carried away to infinity. We also consider shocks in dimensionalities d other than four and find that, for plasmas whose duals are given by asymptotically AdS spaces, the exponential tail of the shock on the supersonic side shrinks as gamma^(-2/d) as the velocity approaches the speed of light (the Lorentz factor gamma goes to infinity). This generalizes the behavior gamma^(-1/2) we have found previously for d=4. Finally, we consider corrugations of the shock front and show that the shock is stable under such perturbations. There are, however, long lived modes, excitations of which describe generation of sound by the shock wave, the energy for this being provided by the incoming fluid.

Sergei Khlebnikov; Martin Kruczenski; Georgios Michalogiorgakis

2011-05-06T23:59:59.000Z

424

Shock waves in strongly coupled plasmas  

Science Conference Proceedings (OSTI)

Shock waves are supersonic disturbances propagating in a fluid and giving rise to dissipation and drag. Weak shocks, i.e., those of small amplitude, can be well described within the hydrodynamic approximation. On the other hand, strong shocks are discontinuous within hydrodynamics and therefore probe the microscopics of the theory. In this paper, we consider the case of the strongly coupled N=4 plasma whose microscopic description, applicable for scales smaller than the inverse temperature, is given in terms of gravity in an asymptotically AdS{sub 5} space. In the gravity approximation, weak and strong shocks should be described by smooth metrics with no discontinuities. For weak shocks, we find the dual metric in a derivative expansion, and for strong shocks we use linearized gravity to find the exponential tail that determines the width of the shock. In particular, we find that, when the velocity of the fluid relative to the shock approaches the speed of light v{yields}1 the penetration depth l scales as l{approx}(1-v{sup 2}){sup 1/4}. We compare the results with second-order hydrodynamics and the Israel-Stewart approximation. Although they all agree in the hydrodynamic regime of weak shocks, we show that there is not even qualitative agreement for strong shocks. For the gravity side, the existence of shock waves implies that there are disturbances of constant shape propagating on the horizon of the dual black holes.

Khlebnikov, Sergei; Kruczenski, Martin; Michalogiorgakis, Georgios [Department of Physics, Purdue University, 525 Northwestern Avenue, West Lafayette, Indiana 47907 (United States)

2010-12-15T23:59:59.000Z

425

Exploring the Roper wave function in Lattice QCD  

E-Print Network (OSTI)

Using a correlation matrix analysis consisting of a variety of smearings, the CSSM Lattice collaboration has successfully isolated states associated with the Roper resonance and other "exotic" excited states such as the $\\Lambda(1405)$ on the lattice at near-physical pion masses. We explore the nature of the Roper by examining the eigenvectors that arise from the variational analysis, demonstrating that the Roper state is dominated by the $\\chi_1$ nucleon interpolator and only poorly couples to $\\chi_2.$ By examining the probability distribution of the Roper on the lattice, we find a structure consistent with a constituent quark model. In particular, the Roper $d$-quark wave function contains a single node consistent with a $2S$ state. A detailed comparison with constituent quark model wave functions is carried out, validating the approach of accessing these states by constructing a variational basis composed of different levels of fermion source and sink smearing.

Kamleh, Waseem; Roberts, Dale S

2013-01-01T23:59:59.000Z

426

Long-Wave Trapping by Oceanic Ridges  

Science Conference Proceedings (OSTI)

Long waves are affected by bottom topography and under certain conditions may be trapped along topographical contours which then act as wave guides transmitting wave energy for great distances with little loss. This study examines waves trapped ...

Richard Paul Shaw; Wayne Neu

1981-10-01T23:59:59.000Z

427

Forcing and Velocity Correlations in a Vibrated Granular Monolayer  

E-Print Network (OSTI)

The role of forcing on the dynamics of a vertically shaken granular monolayer is investigated. Using a flat plate, surprising negative velocity correlations are measured. A mechanism for this anti-correlation is proposed with support from both experimental results and molecular dynamics simulations. Using a rough plate, velocity correlations are positive, and the velocity distribution evolves from a gaussian at very low densities to a broader distribution at high densities. These results are interpreted as a balance between stochastic forcing, interparticle collisions, and friction with the plate.

Alexis Prevost; David A. Egolf; Jeffrey S. Urbach

2002-03-14T23:59:59.000Z

428

Superconducting spoke cavities for high-velocity applications  

SciTech Connect

To date, superconducting spoke cavities have been designed, developed, and tested for particle velocities up to {beta}{sub 0}~0.6, but there is a growing interest in possible applications of multispoke cavities for high-velocity applications. We have explored the design parameter space for low-frequency, high-velocity, double-spoke superconducting cavities in order to determine how each design parameter affects the electromagnetic properties, in particular the surface electromagnetic fields and the shunt impedance. We present detailed design for cavities operating at 325 and 352 MHz and optimized for {beta}{sub 0}~=0.82 and 1.

Hopper, Christopher S. [Old Dominion U.; Delayen, Jean R. [Old Dominion U., JLAB

2013-10-01T23:59:59.000Z

429

Charge Density Wave Compounds  

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

Fisher Research Group Fisher Research Group Layered Chalcogenides 29 February 2008 Controlling the Wave by Brad Plummer, SLAC Communications Stanford University researchers working in part at SSRL have discovered a novel set of properties pertaining to a compound of materials called tritellurides. These compounds, composed of three atoms of tellurium and a single atom of one of the rare earth elements, demonstrate unique electronic properties that can be controlled by altering the temperature of the material. The tritellurides display phenomena known as charge density waves (CDW). In a normal conductive metal, electrons persist in a "sea" wherein they are evenly distributed and equally available, or conductive. A CDW occurs under certain circumstances and causes the electrons to clump together, lowering their availability, and thereby lowering the compound's conductivity. Tellurium, when crystallized into quasi-two-dimensional planes and combined with rare earth elements, produces a material with CDWs that can be manipulated and controlled.

430

Cascade amplification of self-similar frequency-modulated pulses in normal group velocity dispersion active fibres  

SciTech Connect

This paper examines the possibility of efficient amplification of self-similar frequency-modulated wave packets in longitudinally inhomogeneous active fibres. We analyse the dynamics of parabolic pulses with a constant frequency modulation rate and derive algorithms for optimising the group velocity dispersion profile in order to ensure self-similar propagation of such pulses. We demonstrate that the use of a cascade scheme can ensure efficient amplification of individual subpicosecond pulses of this type. (optical fibres, lasers and amplifiers. properties and applications)

Zolotovskii, Igor' O; Okhotnikov, Oleg G; Sementsov, Dmitrii I; Sysolyatin, A A; Fotiadi, A A

2012-09-30T23:59:59.000Z

431

DNA waves and water  

E-Print Network (OSTI)

Some bacterial and viral DNA sequences have been found to induce low frequency electromagnetic waves in high aqueous dilutions. This phenomenon appears to be triggered by the ambient electromagnetic background of very low frequency. We discuss this phenomenon in the framework of quantum field theory. A scheme able to account for the observations is proposed. The reported phenomenon could allow to develop highly sensitive detection systems for chronic bacterial and viral infections.

L. Montagnier; J. Aissa; E. Del Giudice; C. Lavallee; A. Tedeschi; G. Vitiello

2010-12-23T23:59:59.000Z

432

ENERGY CONSERVATION AND GRAVITY WAVES IN SOUND-PROOF TREATMENTS OF STELLAR INTERIORS. II. LAGRANGIAN CONSTRAINED ANALYSIS  

Science Conference Proceedings (OSTI)

The speed of sound greatly exceeds typical flow velocities in many stellar and planetary interiors. To follow the slow evolution of subsonic motions, various sound-proof models attempt to remove fast acoustic waves while retaining stratified convection and buoyancy dynamics. In astrophysics, anelastic models typically receive the most attention in the class of sound-filtered stratified models. Generally, anelastic models remain valid in nearly adiabatically stratified regions like stellar convection zones, but may break down in strongly sub-adiabatic, stably stratified layers common in stellar radiative zones. However, studying stellar rotation, circulation, and dynamos requires understanding the complex coupling between convection and radiative zones, and this requires robust equations valid in both regimes. Here we extend the analysis of equation sets begun in Brown et al., which studied anelastic models, to two types of pseudo-incompressible models. This class of models has received attention in atmospheric applications, and more recently in studies of white-dwarf supernova progenitors. We demonstrate that one model conserves energy but the other does not. We use Lagrangian variational methods to extend the energy conserving model to a general equation of state, and dub the resulting equation set the generalized pseudo-incompressible (GPI) model. We show that the GPI equations suitably capture low-frequency phenomena in both convection and radiative zones in stars and other stratified systems, and we provide recommendations for converting low-Mach number codes to this equation set.

Vasil, Geoffrey M.; Lecoanet, Daniel [Department of Astronomy and Theoretical Astrophysics Center, University of California Berkeley, Berkeley, CA 94720 (United States); Brown, Benjamin P.; Zweibel, Ellen G. [Department of Astronomy, University of Wisconsin, Madison, WI 53706-1582 (United States); Wood, Toby S., E-mail: vasil@cita.utoronto.ca [Department of Applied Mathematics and Statistics, Baskin School of Engineering, University of California, Santa Cruz, CA (United States)

2013-08-20T23:59:59.000Z

433

The influence of waves . . .  

E-Print Network (OSTI)

With the growing interest in offshore wind resources, it has become increasingly important to establish and refine models for the interaction between wind and waves in order to obtain accurate models for the sea surface roughness. The simple Charnock relation that has been applied for open sea conditions does not work well in the shallow water near-coastal areas that are important for offshore wind energy. A model for the surface roughness of the sea has been developed based on this concept, using an expression for the Charnock constant as a function of wave age [1], and then relating the wave `age' to the distance to the nearest upwind coastline. The data used in developing these models originated partly from analysis of data from the Vindeby site, partly from previously published results. The scatter in the data material was considerable and consequently there is a need to test these models further by analysing data from sites exhibiting varying distances to the coast. Results from such analysis of recent data are presented for sites with distances to the coast varying from 10km to several hundreds of km. The model shows a good agreement also with this data.

Bernhard Lange; Jørgen Højstrup

1999-01-01T23:59:59.000Z

434

Efficient Dealiasing of Doppler Velocities Using Local Environment Constraints  

Science Conference Proceedings (OSTI)

A Doppler velocity dealiasing algorithm is described that processes one radial at a time by comparing that radial with a previous radial. This technique has worked reliably on numerous Doppler radar datasets for clear air, thunderstorm, and ...

Michael D. Eilts; Steven D. Smith

1990-02-01T23:59:59.000Z

435

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

436

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 +

437

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 +

438

Vertical Velocity Structures in an Axisymmetric, Nonhydrostatic Tropical Cyclone Model  

Science Conference Proceedings (OSTI)

A statistical analysis of several experiments with different microphysical parameterizations in an axisymmetric, nonhydrostatic tropical cyclone model illustrates the impact of icc-phase microphysics on model vertical velocity structure. The ...

Stephen J. Lord; Jacqueline M. Lord

1988-05-01T23:59:59.000Z

439

Universal Velocity-Field Characteristics for a Nanowire Arbitrary Degeneracy  

Science Conference Proceedings (OSTI)

The effects of electric field on the carrier motion and drift velocity in nanowire (NW) are presented in this paper. When the electric field is applied in NW, the electron is expected to move in anti-parallel direction to the electric field. This is so-called randomness motion is transformed into streamlined motion in extremely high electric field. The normalized Fermi energy and relative electron population as a function of electric field are examined for various degeneracies. It was found that the electric field has lesser influence on the relative electron population with the increased degeneracy. The drift velocity in NW is shown to increase with electric field until it reaches the saturation velocity. Two approximations have been made to simplify the theoretical equation. It is also shown in this paper that when the quantum emission is taken into account, the drift and saturation velocity degrades.

Chek, Desmond C. Y.; Hashim, Abdul Manaf [Faculty of Electrical Eng., Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Tan, Michael Loong Peng [Faculty of Electrical Eng., Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Electrical Engineering Division, Engineering Department, University of Cambridge, 9 J.J. Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Arora, Vijay K. [Faculty of Electrical Eng., Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Division of Engineering and Physics, Wilkes University, Wilkes-Barre, PA 18766 (United States)

2011-05-25T23:59:59.000Z

440

Detiding Three-Dimensional Velocity Survey Data in Coastal Waters  

Science Conference Proceedings (OSTI)

A three-dimensional data interpolation technique is proposed that efficiently removes tidal currents from spatial velocity surveys. The least squares method extends prior two-dimensional detiding methods to three spatial dimensions using ...

Andreas Münchow

2000-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "wave velocity variations" 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

The Finescale Response of Lowered ADCP Velocity Profiles  

Science Conference Proceedings (OSTI)

Lowered acoustic Doppler current profiler (LADCP) velocity profiles are compared with simultaneous higher-resolution expendable current profiler (XCP) profiles to determine the lowered ADCP's response at short wavelengths. Although lowered ADCP ...

Kurt Polzin; Eric Kunze; Jules Hummon; Eric Firing

2002-02-01T23:59:59.000Z

442

TOPS: A Free-Fall Velocity and CTD Profiler  

Science Conference Proceedings (OSTI)

A free-fall instrument, TOPS, measures vertical profiles of horizontal ocean velocity, conductivity and temperature. Profiling capability extends throughout the full water column (6000 db pressure limitation). Larger vertical wavelength (water ...

S. P. Hayes; H. B. Milburn; E. F. Ford

1984-09-01T23:59:59.000Z

443

LOW VELOCITY SHPERE IMPACT OF SODA LIME SILICATE GLASS  

Science Conference Proceedings (OSTI)

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.

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

2012-01-01T23:59:59.000Z

444

Representation of Velocity Gradient Effects in a Gaussian Puff Model  

Science Conference Proceedings (OSTI)

The Gaussian puff model framework is extended to provide a description of velocity shear distortion effects. An efficient splitting-merging algorithm is presented so that a maximum puff size can be specified for a calculation. This localizes the ...

R. I. Sykes; D. S. Henn

1995-12-01T23:59:59.000Z

445

Simulation of Three-Dimensional Turbulent Velocity Fields  

Science Conference Proceedings (OSTI)

New algorithms for the simulation of three-dimensional homogeneous turbulent velocity fields are compared with standard spectral domain algorithms. Results are presented for a von Kármán model of the covariance tensor. For typical atmospheric ...

Rod Frehlich; Larry Cornman; Robert Sharman

2001-02-01T23:59:59.000Z

446

A New Relationship between Mean Doppler Velocity and Differential Reflectivity  

Science Conference Proceedings (OSTI)

A new relationship has been established linking the vertical mean Doppler velocity of raindrop spectra and the accompanying differential reflectivities. It is based upon the specific radar combination of a vertically pointing Doppler and a ...

Matthias Steiner

1991-06-01T23:59:59.000Z

447

Dealiasing of Doppler Radar Velocities Using a Torus Mapping  

Science Conference Proceedings (OSTI)

A novel dealiasing algorithm for Doppler radar velocity data has been developed at the Swedish Meteorological and Hydrological Institute (SMHI). Unlike most other methods, it does not need independent wind information from other instruments (e.g.,...

Günther Haase; Tomas Landelius

2004-10-01T23:59:59.000Z

448

Eulerian and Lagrangian Velocity Distributions in the North Atlantic  

Science Conference Proceedings (OSTI)

Velocity probability density functions (PDFs) are calculated using data from subsurface current meters in the western North Atlantic Ocean. The PDFs are weakly, but significantly, non-Gaussian. They deviate from normality because of an excess of ...

J. H. LaCasce

2005-12-01T23:59:59.000Z

449

Benthic Boundary-Layer Velocity Profiles: Dependence on Averaging Period  

Science Conference Proceedings (OSTI)

The relationship between benthic boundary-layer velocity profiles and current meter averaging time is investigated using detailed (0.61 Hz) current measurements recorded within 1 m of the bottom on the inner continental shelf. The percentage of ...

Barry M. Lesht

1980-06-01T23:59:59.000Z

450

Profiler Measurements of Vertical Velocity Fluctuations in the Ocean  

Science Conference Proceedings (OSTI)

A method is described for measuring the vertical component of velocity fluctuations due to three-dimensional turbulence in the ocean from a freely falling microstructure profiler. The dynamic pressure measurement relies on a commercially ...

J. N. Moum

1990-04-01T23:59:59.000Z

451

Deep Velocity Measurements in the Western Equatorial Indian Ocean  

Science Conference Proceedings (OSTI)

Vertical profiles of horizontal current collected in April and June 1979 in the western Indian Ocean revealed the presence of short vertical scale (150–300 m) deep zonal jets, trapped to within 1° of the equator. Meridional velocity records ...

Rui M. Ponte; James Luyten

1990-01-01T23:59:59.000Z

452

Vorticity from Line-of-Sight Lidar Velocity Scans  

Science Conference Proceedings (OSTI)

A method is presented to compute the spanwise vorticity in polar coordinates from 2D vertical cross sections of high-resolution line-of-sight Doppler wind lidar observations. The method uses the continuity equation to derive the velocity ...

Martin Weissmann; Andreas Dörnbrack; James D. Doyle

2009-12-01T23:59:59.000Z

453

Platform-Motion Correction of Velocity Measured by Doppler Lidar  

Science Conference Proceedings (OSTI)

The NOAA/Earth System Research Laboratory (ESRL) has two coherent Doppler lidar systems that have been deployed on board research vessels to obtain data during several experiments. The instruments measure the wind velocity relative to the motion ...

Reginald J. Hill; W. Alan Brewer; Sara C. Tucker

2008-08-01T23:59:59.000Z

454

VELOCITY EVOLUTION AND THE INTRINSIC COLOR OF TYPE Ia SUPERNOVAE  

SciTech Connect

To understand how best to use observations of Type Ia supernovae (SNe Ia) to obtain precise and accurate distances, we investigate the relations between spectra of SNe Ia and their intrinsic colors. Using a sample of 1630 optical spectra of 255 SNe, based primarily on data from the CfA Supernova Program, we examine how the velocity evolution and line strengths of Si II {lambda}6355 and Ca II H and K are related to the B - V color at peak brightness. We find that the maximum-light velocity of Si II {lambda}6355 and Ca II H and K and the maximum-light pseudo-equivalent width of Si II {lambda}6355 are correlated with intrinsic color, with intrinsic color having a linear relation with the Si II {lambda}6355 measurements. Ca II H and K does not have a linear relation with intrinsic color, but lower-velocity SNe tend to be intrinsically bluer. Combining the spectroscopic measurements does not improve intrinsic color inference. The intrinsic color scatter is larger for higher-velocity SNe Ia-even after removing a linear trend with velocity-indicating that lower-velocity SNe Ia are more 'standard crayons'. Employing information derived from SN Ia spectra has the potential to improve the measurements of extragalactic distances and the cosmological properties inferred from them.

Foley, Ryan J.; Sanders, Nathan E.; Kirshner, Robert P., E-mail: rfoley@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2011-12-01T23:59:59.000Z

455

Design of regulated velocity flow assurance device for petroleum industry  

E-Print Network (OSTI)

The petroleum industry faces problems in transportation of crude petroleum be- cause of the deposition of paraffins, hydrates and asphaltenes on the insides of the pipeline. These are conventionally removed using either chemical inhibitors or mechani- cal devices, called pigs, which travel through the pipeline and mechanically scrape away the deposits. These pigs are propelled by the pipeline product itself and hence travel at the same velocity as the product. Research has indicated that cleaning would be better if the pigs are traveling at a relatively constant velocity of around 70% of the product velocity. This research utilizes the concept of regulating the bypass flow velocity in order to maintain the pig velocity. The bypass flow is regulated by the control unit based on the feedback from the turbine flowmeter, which monitors the bypass flow. A motorized butterfly valve is used for actually controlling the bypass flow. In addition to cleaning, the proposed pig utilizes on-board electronics like accelerom- eter and pressure transducers to store the data gathered during the pig run. This data can then be analyzed and the condition of the pipeline predicted. Thus, this research addresses the problem of designing a pig to maintain a constant velocity in order to achieve better cleaning. It also helps gather elementary data that can be used to predict the internal conditions in the pipe.

Yardi, Chaitanya Narendra

2004-12-01T23:59:59.000Z

456

Geometric phases of the Faraday rotation of electromagnetic waves in magnetized plasmas  

Science Conference Proceedings (OSTI)

Geometric phases of circularly polarized electromagnetic waves in nonuniform magnetized plasmas is studied theoretically. The variation of the propagation direction of circularly polarized waves results in a geometric phase, which also contributes to the Faraday rotation, in addition to the standard dynamical phase. The origin and properties of the geometric phase are investigated. The influence of the geometric phase to plasma diagnostics using the Faraday rotation is discussed as an application of the theory.

Liu Jian [Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Qin Hong [Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

2012-10-15T23:59:59.000Z

457

Precipitation Identification from Radar Wind Profiler Spectral Moment Data: Vertical Velocity Histograms, Velocity Variance, and Signal Power–Vertical Velocity Correlations  

Science Conference Proceedings (OSTI)

Correlations between range-corrected signal power Src and radial vertical velocity Vr, from the vertical beam of a UHF wind profiler can be used to distinguish between air- and precipitation-dominated echoes using an Src–Vr correlation diagram. ...

F. Martin Ralph; Paul J. Neiman; Dominique Ruffieux

1996-06-01T23:59:59.000Z

458

WAVE DELAYING STRUCTURE FOR RECTANGULAR WAVE-GUIDES  

DOE Patents (OSTI)

This patent relates to wave-guides and in particular describes wave delaying structure located within a wave-guide. The disclosed wave-guide has an elongated fiat metal sheet arranged in a central plane of the guide and formed with a series of transverse inductive slots such that each face presents an inductive impedance to the guide. The sheet is thickened in the area between slots to increase the self capacity of the slots. Experimental results indicate that in a wave-guide loaded in accordance with the invention the guided wavelength changes more slowly as the air wavelength is changed than the guided wavelength does in wave-guides loaded by means of corrugations.

Robertson-Shersby-Harvie, R.B.; Dain, J.

1956-11-13T23:59:59.000Z

459

Gravimagnetic shock waves and gravitational-wave experiments  

E-Print Network (OSTI)

Causes of the unsatisfactory condition of the gravitational-wave experiments are discussed and a new outlook at the detection of gravitational waves of astrophysical origin is proposed. It is shown that there are strong grounds for identifying the so-called giant pulses in the pulsar NP 0532 radiation with gravimagnetic shock waves (GMSW) excited in the neutron star magnetosphere by sporadic gravitational radiation of this pulsar.

Yu. G. Ignatyev

2011-01-09T23:59:59.000Z

460

Observation of wave-packet propagation in the ion cyclotron range of frequencies in a tokamak plasma  

DOE Green Energy (OSTI)

Experimental observation of wave-packet propagation in the ion cyclotron range of frequencies in a tokamak plasma is reported. Studies were carried out in the Caltech Research Tokamak (Phys. Fluids {bold 23}, 614 (1980)) in a pure hydrogen plasma and in a regime where fast-wave damping was sufficiently small to permit multiple toroidal transits of the wave packet. Waves were launched by exciting a small loop antenna with a short burst of radio-frequency current and were detected with shielded magnetic probes. Probe scans revealed a large increase in wave-packet amplitude at smaller minor radii, and the packet velocity was found to be independent of radial position. Measurement of the packet transit time yielded direct information about the wave group velocity. Packet velocity was investigated as a function of the fundamental excitation frequency, plasma density, and toroidal magnetic field. Results are compared with the predictions of a cold plasma model that includes a vacuum layer at the edge.

Greene, G.J. (Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (USA)); Gould, R.W. (California Institute of Technology, Pasadena, CA (USA))

1991-02-01T23:59:59.000Z

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461

Dual output acoustic wave sensor for molecular identification  

DOE Patents (OSTI)

A method of identification and quantification of absorbed chemical species by measuring changes in both the velocity and the attenuation of an acoustic wave traveling through a thin film into which the chemical species is sorbed. The dual output response provides two independent sensor responses from a single sensing device thereby providing twice as much information as a single output sensor. This dual output technique and analysis allows a single sensor to provide both the concentration and the identity of a chemical species or permits the number of sensors required for mixtures to be reduced by a factor of two.

Frye, Gregory C. (Cedar Crest, NM); Martin, Stephen J. (Albuquerque, NM)

1991-01-01T23:59:59.000Z

462

Riding the Waves: Harnessing Ocean Wave Energy through ...  

Science Conference Proceedings (OSTI)

... The opportunities for ocean wave power to become a new, reliable and clean source of renewable energy will be discussed, as well as activities of ...

2012-04-04T23:59:59.000Z

463

Practical speed meter designs for QND gravitational-wave interferometers  

E-Print Network (OSTI)

In the quest to develop viable designs for third-generation optical interferometric gravitational-wave detectors (e.g., LIGO-III and EURO), one strategy is to monitor the relative momentum or speed of the test-mass mirrors, rather than monitoring their relative position. A previous paper analyzed a straightforward but impractical design for a {\\it speed-meter interferometer} that accomplishes this. This paper describes some practical variants of speed-meter interferometers. Like the original interferometric speed meter, these designs {\\it in principle} can beat the gravitational-wave standard quantum limit (SQL) by an arbitrarily large amount, over an arbitrarily wide range of frequencies. These variants essentially consist of a Michelson interferometer plus an extra "sloshing" cavity that sends the signal back into the interferometer with opposite phase shift, thereby cancelling the position information and leaving a net phase shift proportional to the relative velocity. {\\it In practice}, the sensitivity of...

Purdue, P; Purdue, Patricia; Chen, Yanbei

2002-01-01T23:59:59.000Z

464

Iterated multidimensional wave conversion  

Science Conference Proceedings (OSTI)

Mode conversion can occur repeatedly in a two-dimensional cavity (e.g., the poloidal cross section of an axisymmetric tokamak). We report on two novel concepts that allow for a complete and global visualization of the ray evolution under iterated conversions. First, iterated conversion is discussed in terms of ray-induced maps from the two-dimensional conversion surface to itself (which can be visualized in terms of three-dimensional rooms). Second, the two-dimensional conversion surface is shown to possess a symplectic structure derived from Dirac constraints associated with the two dispersion surfaces of the interacting waves.

Brizard, A. J. [Dept. Physics, Saint Michael's College, Colchester, VT 05439 (United States); Tracy, E. R.; Johnston, D. [Dept. Physics, College of William and Mary, Williamsburg, VA 23187-8795 (United States); Kaufman, A. N. [LBNL and Physics Dept., UC Berkeley, Berkeley, CA 94720 (United States); Richardson, A. S. [T-5, LANL, Los Alamos, NM 87545 (United States); Zobin, N. [Dept. Mathematics, College of William and Mary, Williamsburg, VA 23187-8795 (United States)

2011-12-23T23:59:59.000Z

465

Gravity Waves in the Sun  

E-Print Network (OSTI)

We present numerical simulations of penetrative convection and gravity wave excitation in the Sun. Gravity waves are self-consistently generated by a convective zone overlying a radiative interior. We produce power spectra for gravity waves in the radiative region as well as estimates for the energy flux of gravity waves below the convection zone. We calculate a peak energy flux in waves below the convection zone to be three orders of magnitude smaller than previous estimates for m=1. The simulations show that the linear dispersion relation is a good approximation only deep below the convective-radiative boundary. Both low frequency propagating gravity waves as well as higher frequency standing modes are generated; although we find that convection does not continually drive the standing g-mode frequencies.

Tamara M. Rogers; Gary A. Glatzmaier

2005-08-25T23:59:59.000Z

466

Effects of flow transients on the burning velocity of hydrogen-air premixed flames  

DOE Green Energy (OSTI)

The effects of unsteady strain rate on the burning velocity of hydrogen-air premixed flames are studied in an opposed nozzle configuration. The numerical method employs adaptive time integration of a system of differential-algebraic equations. Detailed hydrogen-air kinetic mechanism and transport properties are considered. The equivalence ratio is varied from lean to rich premixtures in order to change the effective Lewis number. Steady Markstein numbers for small strain rate are computed and compared with experiment. Different definitions of flame burning velocity are examined under steady and unsteady flow conditions. It is found that, as the unsteady frequency increases, large deviations between different flame speeds are noted depending on the location of the flame speed evaluation. Unsteady flame response is investigated in terms of the Markstein transfer function which depends on the frequency of oscillation. In most cases, the flame speed variation attenuates at higher frequencies, as the unsteady frequency becomes comparable to the inverse of the characteristic flame time. Furthermore, unique resonance-like behavior is observed for a range of rich mixture conditions, consistent with previous studies with linearized theory.

H. G. Im; J. H. Chen

2000-07-30T23:59:59.000Z

467

Trapping and transmission of matter-wave solitons in a collisionally inhomogeneous environment  

E-Print Network (OSTI)

We investigate bright matter-wave solitons in the presence of a spatially varying scattering length. It is demonstrated that, even in the absence of any external trapping potential, a soliton can be confined due to the