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1

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

2

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

E-Print Network (OSTI)

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

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

2014-01-01T23:59:59.000Z

3

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 92, NO. B1, PAGES 393-405, JANUARY 10, 1987 P Wave Velocity Variations in the Coso Region, California,  

E-Print Network (OSTI)

GeophysicsDivision, SandiaNational Laboratories,Albuquerque,New Mexico ROBERT W. CLAYTON Seismological velocity variations in the Indian Wells Valley-Coso region of southeasternCalifornia. The residuals layer reflect local geology, including slow velocities for the sedimentary basins of Indian Wells

Clayton, Robert W.

4

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

5

P And S Wave Velocity Determination  

E-Print Network (OSTI)

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

Willis, M. E.

1983-01-01T23:59:59.000Z

6

Measurement of velocity field in parametrically excited solitary waves  

E-Print Network (OSTI)

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

Gordillo, Leonardo

2014-01-01T23:59:59.000Z

7

Measurements of parallel electron velocity distributions using whistler wave absorption  

SciTech Connect

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

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

2012-08-15T23:59:59.000Z

8

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

SciTech Connect

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

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

2014-06-15T23:59:59.000Z

9

VARIATIONAL BOUSSINESQ MODEL FOR SIMULATION OF COASTAL WAVES AND TSUNAMIS  

E-Print Network (OSTI)

1 VARIATIONAL BOUSSINESQ MODEL FOR SIMULATION OF COASTAL WAVES AND TSUNAMIS DIDIT ADYTIA E. VAN, Enschede, Netherlands In this paper we describe the basic ideas of a so-called Variational Boussinesq Model the background of a Variational Boussinesq Model (VBM) and a finite element implementation for coastal waves

Al Hanbali, Ahmad

10

Assessment of wave energy variation in the Persian Gulf  

Science Journals Connector (OSTI)

Abstract Since wave energy has the highest marine energy density in the coastal areas, assessment of its potential is of great importance. Furthermore, long term variation of wave power must be studied to ensure the availability of stable wave energy. In this paper, wave energy potential is assessed along the southern coasts of Iran, the Persian Gulf. For this purpose, SWAN numerical model and ECMWF wind fields were used to produce the time series of wave characteristics over 25 years from 1984 till 2008. Moreover, three points in the western, central and eastern parts of the Persian Gulf were selected and the time series of energy extracted from the modeled waves were evaluated at these points. The results show that there are both seasonal and decadal variations in the wave energy trends in all considered points due to the climate variability. There was a reduction in wave power values from 1990 to 2000 in comparison with the previous and following years. Comparison of wind speed and corresponding wave power variations indicates that a small variation in the wind speed can cause a large variation in the wave power. The seasonal oscillations lead to variation of the wave power from the lowest value in summer to the highest value in winter in all considered stations. In addition, the seasonal trend of wave power changed during the decadal variation of wave power. Directional variations of wave power were also assessed during the decadal variations and the results showed that the dominant direction of wave propagation changed in the period of 1990 to 2000 especially in the western station.

B. Kamranzad; A. Etemad-shahidi; V. Chegini

2013-01-01T23:59:59.000Z

11

The Velocity of Propagation of Longitudinal Waves in Liquids at Audio-Frequencies  

Science Journals Connector (OSTI)

A method for measuring the velocity of propagation of longitudinal waves in liquids is described which is at the same time precise and convenient of application. A column of liquid contained in a cylindrical vertical steel tube was brought into resonance vibration at audio frequency by an electromagnetically excited diaphragm at the bottom. From the solution of the equation of propagation it is shown that when the resonance frequency of the system is the same as that of the diaphragm the reaction of the latter on the system is very small. The height of the column of liquid in the tube was adjusted until its natural frequency nearly corresponded with the predetermined resonance frequency of the diaphragm. The height was then varied slightly and the frequency adjusted until resonance occurred. From several observations of this type the appropriate height corresponding to the resonance frequency of the diaphragm was obtained by interpolation. The velocity of propagation of the longitudinal waves was then calculated from the relation V=f0, where f0 is the natural frequency of the diaphragm when clamped in the holder and ? is the wavelength.Correction for the elasticity of the walls of the tube.—The correction formulas of Korteweg, Lamb and Gronwall were tested experimentally on tubes of different dimensions. The latter was found to give the most satisfactory agreement, the two former being unsuitable for precision measurements.Measurements.—The velocity of sound was measured in air-free distilled water at 25°C. The average of 52 observations gave for this velocity 1485.4±2.3 m/sec. From this value the bulk modulus, G, and the adiabatic compressibility, ?, were calculated. Curves were plotted illustrating the variation of the velocity of sound with temperature for the range 25°-70°C and with concentration for solutions of NaCl and KCl of different normalities. Curves for the corresponding variations of G and ? are also given.

Louis Gordon Pooler

1930-04-01T23:59:59.000Z

12

Temporal Velocity Variations beneath the Coso Geothermal Field...  

Open Energy Info (EERE)

beneath the Coso Geothermal Field Observed using Seismic Double Difference Tomography of Compressional and Shear Wave Arrival Times Jump to: navigation, search GEOTHERMAL...

13

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

SciTech Connect

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

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

2012-05-17T23:59:59.000Z

14

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

Science Journals Connector (OSTI)

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

R. Grimshaw

1980-12-01T23:59:59.000Z

15

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

Science Journals Connector (OSTI)

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

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

2005-03-01T23:59:59.000Z

16

Velocity width of the resonant domain in wave-particle interaction  

Science Journals Connector (OSTI)

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

Marie-Christine Firpo and Fabrice Doveil

2001-12-19T23:59:59.000Z

17

Variational Structure of Inverse Problems in Wave Propagation and Vibration  

E-Print Network (OSTI)

Variational Structure of Inverse Problems in Wave Propagation and Vibration James G. Berryman in wave propagation (traveltime tomography) and two examples in vibration (the plucked string and free.'' For vibrating systems, the apparently very complex behavior of an excited string, drumhead, or the Earth can

18

Solitary Waves of the MRLW Equation by Variational Iteration Method  

SciTech Connect

In a recent publication, Soliman solved numerically the modified regularized long wave (MRLW) equation by using the variational iteration method (VIM). In this paper, corrected numerical results have been computed, plotted, tabulated, and compared with not only the exact analytical solutions but also the Adomian decomposition method results. Solitary wave solutions of the MRLW equation are exactly obtained as a convergent series with easily computable components. Propagation of single solitary wave, interaction of two and three waves, and also birth of solitons have been discussed. Three invariants of motion have been evaluated to determine the conservation properties of the problem.

Hassan, Saleh M. [Department of Mathematics, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Department of Mathematics, College of Science, Ain Shams University, Abbassia 11566, Cairo (Egypt); Alamery, D. G. [Department of Mathematics, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia)

2009-09-09T23:59:59.000Z

19

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

E-Print Network (OSTI)

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

Barrash, Warren

20

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.

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

Excitation of solitons by an external resonant wave with a slowly varying phase velocity  

SciTech Connect

A novel mechanism is proposed for the excitation of solitons in nonlinear dispersive media. The mechanism employs an external pumping wave with a varying phase velocity, which provides a continuous resonant excitation of a nonlinear wave in the medium. Two different schemes of a continuous resonant growth (continuous phase-locking) of the induced nonlinear wave are suggested. The first of them requires a definite time dependence of the pumping wave phase velocity and is relatively sensitive to the initial wave phase. The second employs the dynamic autoresonance effect and is insensitive to the exact time dependence of the pumping wave phase velocity. It is demonstrated analytically and numerically, for a particular example of a driven Korteweg-de Vries (KdV) equation with periodic boundary conditions, that as the nonlinear wave grows, it transforms into a soliton, which continues growing and accelerating adiabatically. A fully nonlinear perturbation theory is developed for the driven KdV equation to follow the growing wave into the strongly nonlinear regime and describe the soliton formation.

Aranson, I.; Meerson, B. [Hebrew Univ., Jerusalem (Israel). Racah Inst. of Physics; Tajima, Toshiki [Texas Univ., Austin, TX (United States)

1992-02-01T23:59:59.000Z

22

Measurement of shear wave velocity of heavy oil De-hua Han, Jiajin Liu, University of Houston  

E-Print Network (OSTI)

for measurement of fluid velocity is to measure the travel time of the transmission wave and then the velocity can water, has been used and is good for P-wave measurement for a lot of fluid samples. But the transmission the principle of this method. The shear wave transducer is coupled with a buffer made of some kind of plastic

23

Shift in the longitudinal sound velocity due to sliding charge-density waves  

Science Journals Connector (OSTI)

The nonlinear conductivity observed for moderate electric fields in NbSe3, TaS3, (TaS4)2I, and K0.3MoO3 below the charge-density-wave-transition is believed to be due to the sliding of the charge-density waves. The sliding motion leads to a Doppler shift of the x-ray diffraction peaks, but this effect has not yet been resolved. We show here that besides the Doppler shift, a sliding incommensurate charge-density wave causes a change in the longitudinal sound velocity of the crystal that is linear in the charge-density-wave velocity. The resulting anisotropic shift is estimated in a mean-field approximation and found to be experimentally observable.

S. N. Coppersmith and C. M. Varma

1984-09-15T23:59:59.000Z

24

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

E-Print Network (OSTI)

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

Laske, Gabi

25

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

E-Print Network (OSTI)

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

American Society for Testing and Materials. Philadelphia

2011-01-01T23:59:59.000Z

26

Generation of lower hybrid and whistler waves by an ion velocity ring distribution  

SciTech Connect

Using fully kinetic simulations in two and three spatial dimensions, we consider the generation and nonlinear evolution of lower hybrid waves produced by a cold ion ring velocity distribution in a low beta plasma. We show that the initial development of the instability is very similar in two and three dimensions and not significantly modified by electromagnetic effects, consistent with linear theory. At saturation, the level of electric field fluctuations is a small fraction of the background thermal energy; the electric field and corresponding density fluctuations consist of long, field-aligned striations. Energy extracted from the ring goes primarily into heating the background ions and the electrons at comparable rates. The initial growth and saturation of the magnetic components of the lower hybrid waves are related to the electric field components, consistent with linear theory. As the growing electric field fluctuations saturate, parallel propagating whistler waves develop by the interaction of two lower hybrid waves. At later times, these whistlers are replaced by longer wavelength, parallel propagating whistlers that grow through the decay of the lower hybrid fluctuations. Wave matching conditions demonstrate these conversion processes of lower hybrid waves to whistler waves. The conversion efficiency (=ratio of the whistler wave energy to the energy in the saturated lower hybrid waves) is computed and found to be significant ({approx}15%) for the parameters of the three-dimensional simulation (and even larger in the two-dimensional simulation), although when normalized in terms of the initial kinetic energy in the ring ions the overall efficiency is very small (<10{sup -4}). The results are compared with relevant linear and nonlinear theory.

Winske, D.; Daughton, W. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2012-07-15T23:59:59.000Z

27

Green's Functions for Surface Waves in a Generic Velocity Structure 1 Victor C. Tsai and Sarun Atiganyanun* 3  

E-Print Network (OSTI)

1 Green's Functions for Surface Waves in a Generic Velocity Structure 1 and Green's functions have been well established 14 for many decades. However, or Green's function surface displacement. We address this gap in the 19 literature

28

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

SciTech Connect

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

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

1999-09-01T23:59:59.000Z

29

Upper mantle structure of South America from joint inversion of waveforms and fundamental mode group velocities of Rayleigh waves  

E-Print Network (OSTI)

Upper mantle structure of South America from joint inversion of waveforms and fundamental mode tomographic S wave velocity model for the upper mantle beneath South America is presented. We developed three-dimensional (3-D) upper mantle S velocity model and a Moho depth model for South America, which

van der Lee, Suzan

30

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

31

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

32

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

33

Ion Bernstein waves in a plasma with a kappa velocity distribution  

SciTech Connect

Using a Vlasov-Poisson model, a numerical investigation of the dispersion relation for ion Bernstein waves in a kappa-distributed plasma has been carried out. The dispersion relation is found to depend significantly on the spectral index of the ions, ?{sub i}, the parameter whose smallness is a measure of the departure from thermal equilibrium of the distribution function. Over all cyclotron harmonics, the typical Bernstein wave curves are shifted to higher wavenumbers (k) if ?{sub i} is reduced. For waves whose frequency lies above the lower hybrid frequency, ?{sub LH}, an increasing excess of superthermal particles (decreasing ?{sub i}) reduces the frequency, ?{sub peak}, of the characteristic peak at which the group velocity vanishes, while the associated k{sub peak} is increased. As the ratio of ion plasma to cyclotron frequency (?{sub pi}/?{sub ci}) is increased, the fall-off of ? at large k is smaller for lower ?{sub i} and curves are shifted towards larger wavenumbers. In the lower hybrid frequency band and harmonic bands above it, the frequency in a low-?{sub i} plasma spans only a part of the intraharmonic space, unlike the Maxwellian case, thus exhibiting considerably less coupling between adjacent bands for low ?{sub i}. It is suggested that the presence of the ensuing stopbands may be a useful diagnostic for the velocity distribution characteristics. The model is applied to the Earth's plasma sheet boundary layer in which waves propagating perpendicularly to the ambient magnetic field at frequencies between harmonics of the ion cyclotron frequency are frequently observed.

Nsengiyumva, F.; Mace, R. L.; Hellberg, M. A. [School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4000 (South Africa)] [School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4000 (South Africa)

2013-10-15T23:59:59.000Z

34

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

SciTech Connect

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

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

1993-10-01T23:59:59.000Z

35

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

SciTech Connect

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

Larner, K.

1992-01-01T23:59:59.000Z

36

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

SciTech Connect

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

Larner, K.

1992-10-01T23:59:59.000Z

37

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

E-Print Network (OSTI)

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

Protat, Alain

38

Approximate analytical method and its use for calculation of phase velocities of acoustic plane waves in crystals for example LiNbO3  

E-Print Network (OSTI)

By means of the offered analytical method the determinant relation for a phase velocities of elastic waves for an arbitrary propagation directions in a piezoelectric crystal are received. The phase velocities of three normal elastic waves for the crystal of LiNbO3 are calculated. Results of this calculation for each of waves are presented graphically in the form of the cards allowing easily to define phase velocities in any given direction in crystal.

A. A. Golubeva

2010-07-26T23:59:59.000Z

39

The effect of freestream variations on the propagation of detonation and combustion waves  

E-Print Network (OSTI)

THE EFFECT OF FREESTREAM VARIATIONS ON THE PROPAGATION OF DETONATION AND COMBUSTION WAVES A Thesis by MARLON LEE CLARK Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE August 1988 Major Subject: Aerospace Engineering THE EFFECT OF FREESTREAM VARIATIONS ON THE PROPAGATION OF DETONATION AND COMBUSTION WAVES A Thesis by MARLON LEE CLARK Approved as to style and content by: eland A. Garison...

Clark, Marlon Lee

2012-06-07T23:59:59.000Z

40

Red Algae Respond to Waves: Morphological and Mechanical Variation in Mastocarpus papillatus Along  

E-Print Network (OSTI)

Red Algae Respond to Waves: Morphological and Mechanical Variation in Mastocarpus papillatus Along Grove, California, 93950 Abstract. Intertidal algae are exposed to the potentially severe drag forces generated by crashing waves, and several species of brown algae respond, in part, by varying the strength

Denny, Mark

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While these samples are representative of the content of NLEBeta,
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41

Green's Functions for Surface Waves in a Generic Velocity Structure by Victor C. Tsai and Sarun Atiganyanun*  

E-Print Network (OSTI)

Short Note Green's Functions for Surface Waves in a Generic Velocity Structure by Victor C. Tsai displacement/stress eigenfunctions and Green's functions have been well established for many decades. However on frequency, or Green's function surface displacement. We address this gap in the liter- ature and here

42

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

43

PRACTICAL USE OF VARIATIONAL PRINCIPLES FOR MODELING WATER WAVES  

E-Print Network (OSTI)

the equations of Korteweg and de Vries [KdV95], Boussinesq [Bou71], Benjamin et al. [BBM72], Serre [Ser53 Abstract. This paper describes a method for deriving approximate equations for irro- tational water waves combinations, several model equations are derived, some being well-known, other being new. The models obtained

44

Migration error in transversely isotropic media with linear velocity variation in depth  

SciTech Connect

Given the sensitivity of imaging accuracy to the velocity used in migration, migration founded (as in practice) on the erroneous assumption that a medium is isotropic can be expected to be inaccurate for steep reflectors. Here, we estimate errors in interpreted reflection time and lateral position as a function of reflector dip for transversely isotropic models in which the axis of symmetry is vertical and the medium velocity varies linearly with depth. We limit consideration to media in which ratios of the various elastic moduli are independent of depth. Tests with reflector dips up to 120 degrees on a variety of anisotropic media show errors that axe tens of wavelengths for dips beyond 90 degrees when the medium (unrealistically) is homogeneous. For a given anisotropy, the errors are smaller for inhomogeneous media; the larger the velocity gradient, the smaller the errors. For gradients that are representative of the subsurface, lateral-position errors tend to be minor for dips less than about 60 degrees, growing to two to five wavelengths as dip passes beyond 90 degrees. These errors depend on reflector depth and average velocity to the reflector only through their ratio, i.e., migrated reflection time. Migration error, which is found to be unrelated to the ratio of horizontal to vertical velocity, is such that reflections with later migrated reflection times tend to be more severely over-migrated than are those with earlier ones. Over a large range of dips, migration errors that arise when anisotropy is ignored but inhomogeneity is honored tend to be considerably smaller than those encountered when inhomogeneity is ignored in migrating data from isotropic, inhomogeneous media.

Larner, K.; Cohen, J.K.

1992-01-01T23:59:59.000Z

45

Migration error in transversely isotropic media with linear velocity variation in depth  

SciTech Connect

Given the sensitivity of imaging accuracy to the velocity used in migration, migration founded (as in practice) on the erroneous assumption that a medium is isotropic can be expected to be inaccurate for steep reflectors. Here, we estimate errors in interpreted reflection time and lateral position as a function of reflector dip for transversely isotropic models in which the axis of symmetry is vertical and the medium velocity varies linearly with depth. We limit consideration to media in which ratios of the various elastic moduli are independent of depth. Tests with reflector dips up to 120 degrees on a variety of anisotropic media show errors that axe tens of wavelengths for dips beyond 90 degrees when the medium (unrealistically) is homogeneous. For a given anisotropy, the errors are smaller for inhomogeneous media; the larger the velocity gradient, the smaller the errors. For gradients that are representative of the subsurface, lateral-position errors tend to be minor for dips less than about 60 degrees, growing to two to five wavelengths as dip passes beyond 90 degrees. These errors depend on reflector depth and average velocity to the reflector only through their ratio, i.e., migrated reflection time. Migration error, which is found to be unrelated to the ratio of horizontal to vertical velocity, is such that reflections with later migrated reflection times tend to be more severely over-migrated than are those with earlier ones. Over a large range of dips, migration errors that arise when anisotropy is ignored but inhomogeneity is honored tend to be considerably smaller than those encountered when inhomogeneity is ignored in migrating data from isotropic, inhomogeneous media.

Larner, K.; Cohen, J.K.

1992-10-01T23:59:59.000Z

46

E-Print Network 3.0 - acoustic wave velocity Sample Search Results  

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43.30.Ft, 43... short range was deemed desirable for isolating the effects of shallow water internal waves on acoustic... internal waves are not un- usual and it was ......

47

Seasonal variation of upper tropospheric and lower stratospheric equatorial waves over the tropical Pacific  

SciTech Connect

Upper tropospheric and lower stratospheric wind data spanning 31 years from 1964 to 1994 were analyzed at rawinsonde stations in the central/western Pacific. Traditional spectral and cross-spectral analysis led to the conclusion that there is a significant signal with periods between 3 and 4.5 days, which the authors link with the dominant antisymmetric waves predicted by theory to have these periods, mixed Rossby-gravity waves, and equatorial Rossby waves. Then the authors applied the seasonally varying spectral analysis method developed by Madden to study the average seasonal variation of these waves. The seasonally varying analysis suggested that there are significant twice-yearly maxima in equatorial wave activity throughout the upper troposphere and lower stratosphere, with peaks occurring in late winter-spring and in late summer-fall. The twice-yearly signal was most prominent at the 70-hPa and 100-hPa levels. Similar and consistent results were also shown by an autoregressive cyclic spectral analysis. The cyclic spectral analysis suggested that the frequency characteristics of the v-wind wave power are different during the two maxima at some stations. In addition, the seasonally varying squared coherence between the u and v winds and the associated phase implied that there is horizontal momentum flux associated with these waves and that the sign of the flux is different during the two maxima. The differences in wave characteristics during the maxima periods may be related to different wave modes, seasonal variation of the basic zonal state, or possibly to different equatorial wave forcing mechanisms (i.e., convective versus lateral excitations). 52 refs., 12 figs.

Wikle, C.K.; Tsing-Chang Chen [Iowa State Univ., Ames, IA (United States)] [Iowa State Univ., Ames, IA (United States); Madden, R.A. [National Center for Atmospheric Research, Boulder, CO (United States)] [National Center for Atmospheric Research, Boulder, CO (United States)

1997-07-15T23:59:59.000Z

48

Dependence of the Shape of a Detonation Wave Front on the Detonation Wave Velocity upon Detonation of a Cylindrical Charge  

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The transition of a system of partial differential equations which describe the stationary flow behind the shock–wave front of a detonation complex upon detonation of a cylindrical charge to a system...

A. R. Gushanov

2001-01-01T23:59:59.000Z

49

Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume V S-Wave Measurements in Borehole C4996 Seismic Records, Wave-Arrival Identifications and Interpreted S-Wave Velocity Profile.  

SciTech Connect

Velocity measurements in shallow sediments from ground surface to approximately 370 to 400 feet bgs were collected by Redpath Geophysics using impulsive S- and P-wave seismic sources (Redpath 2007). Measurements below this depth within basalt and sedimentary interbeds were made by UTA between October and December 2006 using the T-Rex vibratory seismic source in each of the three boreholes. Results of these measurements including seismic records, wave-arrival identifications and interpreted velocity profiles are presented in the following six volumes: I. P-Wave Measurements in Borehole C4993 II. P-Wave Measurements in Borehole C4996 III. P-Wave Measurements in Borehole C4997 IV. S-Wave Measurements in Borehole C4993 V. S-Wave Measurements in Borehole C4996 VI. S-Wave Measurements in Borehole C4997 In this volume (V), all S-wave measurements are presented that were performed in Borehole C4996 at the WTP with T-Rex as the seismic source and the Lawrence Berkeley National Laboratory (LBNL) 3-D wireline geophone as the at-depth borehole receiver.

Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R.; Menq, Farn-Yuh

2007-06-06T23:59:59.000Z

50

Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume VI S-Wave Measurements in Borehole C4997 Seismic Records, Wave-Arrival Identifications and Interpreted S-Wave Velocity Profile.  

SciTech Connect

Velocity measurements in shallow sediments from ground surface to approximately 370 to 400 feet bgs were collected by Redpath Geophysics using impulsive S- and P-wave seismic sources (Redpath 2007). Measurements below this depth within basalt and sedimentary interbeds were made by UTA between October and December 2006 using the T-Rex vibratory seismic source in each of the three boreholes. Results of these measurements including seismic records, wave-arrival identifications and interpreted velocity profiles are presented in the following six volumes: I. P-Wave Measurements in Borehole C4993 II. P-Wave Measurements in Borehole C4996 III. P-Wave Measurements in Borehole C4997 IV. S-Wave Measurements in Borehole C4993 V. S-Wave Measurements in Borehole C4996 VI. S-Wave Measurements in Borehole C4997 In this volume (VI), all S-wave measurements are presented that were performed in Borehole C4997 at the WTP with T-Rex as the seismic source and the Lawrence Berkeley National Laboratory (LBNL) 3-D wireline geophone as the at-depth borehole receiver.

Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R.; Menq, Farn-Yuh

2007-06-06T23:59:59.000Z

51

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

E-Print Network (OSTI)

for wood-based panel products. In the forest products industry, nondestructive evaluation (NDE) technology, Ross and Pellerin 1994). One NDE technique, which uses stress-wave propagation characteristics, has received considerable atten- tion. Stress-wave-based NDE techniques have been investi- gated extensively

52

Coherent molecular transistor: Control through variation of the gate wave function  

SciTech Connect

In quantum interference transistors (QUITs), the current through the device is controlled by variation of the gate component of the wave function that interferes with the wave function component joining the source and the sink. Initially, mesoscopic QUITs have been studied and more recently, QUITs at the molecular scale have been proposed and implemented. Typically, in these devices the gate lead is subjected to externally adjustable physical parameters that permit interference control through modifications of the gate wave function. Here, we present an alternative model of a molecular QUIT in which the gate wave function is directly considered as a variable and the transistor operation is discussed in terms of this variable. This implies that we specify the gate current as well as the phase of the gate wave function component and calculate the resulting current through the source-sink channel. Thus, we extend on prior works that focus on the phase of the gate wave function component as a control parameter while having zero or certain discrete values of the current. We address a large class of systems, including finite graphene flakes, and obtain analytic solutions for how the gate wave function controls the transistor.

Ernzerhof, Matthias, E-mail: Matthias.Ernzerhof@UMontreal.ca [Département de Chimie, Université de Montréal, C.P. 6128 Succursale A, Montréal, Quebec H3C 3J7 (Canada)] [Département de Chimie, Université de Montréal, C.P. 6128 Succursale A, Montréal, Quebec H3C 3J7 (Canada)

2014-03-21T23:59:59.000Z

53

P- and SV-wave transversely isotropic phase velocities analysis from VSP data  

Science Journals Connector (OSTI)

......Measured anisotropy in Pierre Shale, Geophys. Prosp., 31...been applied to the Pierre Shale data (White, Martineau...elastic wave propagation in anisotropic media is the fact that the...al. (1983) in the Pierre Shale where two neighbouring wells......

J. de Parscau

1991-12-01T23:59:59.000Z

54

Gauge-invariant and infrared-improved variational analysis of the Yang-Mills vacuum wave functional  

SciTech Connect

We study a gauge-invariant variational framework for the Yang-Mills vacuum wave functional. Our approach is built on gauge-averaged Gaussian trial functionals which substantially extend previously used trial bases in the infrared by implementing a general low-momentum expansion for the vacuum-field dispersion (which is taken to be analytic at zero momentum). When completed by the perturbative Yang-Mills dispersion at high momenta, this results in a significantly enlarged trial-functional space which incorporates both dynamical mass generation and asymptotic freedom. After casting the dynamics associated with these wave functionals into an effective action for collections of soft vacuum-field orbits, the leading infrared improvements manifest themselves as four-gradient interactions. Those turn out to significantly lower the minimal vacuum energy density, thus indicating a clear overall improvement of the vacuum description. The dimensional transmutation mechanism and the dynamically generated mass scale remain almost quantitatively robust, however, which ensures that our prediction for the gluon condensate is consistent with standard values. Further results include a finite group velocity for the soft gluonic modes due to the higher-gradient corrections and indications for a negative differential color resistance of the Yang-Mills vacuum.

Forkel, Hilmar [Institut fuer Physik, Humboldt-Universitaet zu Berlin, D-12489 Berlin (Germany)

2010-04-15T23:59:59.000Z

55

Surface wave phase velocities of the Western United States from a two-station method  

Science Journals Connector (OSTI)

......the University of Colorado at Boulder (Lin et-al. 2009), which...Cascade Ranges, Columbia Plateau flood basalts, HLP and NW BR (High...colocated with the Columbia River flood basalts to the east in Washington...observed beneath the Columbia River flood basalt province. Love wave......

Anna Foster; Göran Ekström; Meredith Nettles

2014-01-01T23:59:59.000Z

56

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

Science Journals Connector (OSTI)

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

M. Riedel; D. Goldberg; G. Guerin

2014-01-01T23:59:59.000Z

57

Theory on excitations of drift Alfvén waves by energetic particles. I. Variational formulation  

SciTech Connect

A unified theoretical framework is presented for analyzing various branches of drift Alfvén waves and describing their linear and nonlinear behaviors, covering a wide range of spatial and temporal scales. Nonlinear gyrokinetic quasineutrality condition and vorticity equation, derived for drift Alfvén waves excited by energetic particles in fusion plasmas, are cast in integral form, which is generally variational in the linear limit; and the corresponding gyrokinetic energy principle is obtained. Well known forms of the kinetic energy principle are readily recovered from this general formulation. Furthermore, it is possible to demonstrate that the general fishbone like dispersion relation, obtained within the present theoretical framework, provides a unified description of drift Alfvén waves excited by energetic particles as either Alfvén eigenmodes or energetic particle modes. The advantage of the present approach stands in its capability of extracting underlying linear and nonlinear physics as well as spatial and temporal scales of the considered fluctuation spectrum. For these reasons, this unified theoretical framework can help understanding experimental observations as well as numerical simulation and analytic results with different levels of approximation. Examples and applications are given in Paper II [F. Zonca and L. Chen, “Theory on excitations of drift Alfvén waves by energetic particles. II. The general fishbone-like dispersion relation,” Phys. Plasmas 21, 072121 (2014)].

Zonca, Fulvio, E-mail: fulvio.zonca@enea.it [ENEA C. R. Frascati, Via E. Fermi 45, CP 65-00044 Frascati (Italy); Institute for Fusion Theory and Simulation and Department of Physics, Zhejiang University, Hangzhou 310027 (China); Chen, Liu [Institute for Fusion Theory and Simulation and Department of Physics, Zhejiang University, Hangzhou 310027 (China); Department of Physics and Astronomy, University of California, Irvine, California 92697-4575 (United States)

2014-07-15T23:59:59.000Z

58

Three-body correlations in the variational wave function of liquid He4  

Science Journals Connector (OSTI)

A product of two-body (fij) and three-body (fijk) correlation functions is used as a variational wave function for liquid He4. The fijk take into account the backflows produced by two particles recoiling from each other. The distribution functions, the energy, and its uncertainty are all calculated using the Lennard-Jones-deBoer-Michel potential, and diagrammatic hypernetted-chain summation methods. The calculated equilibrium energy of -6.72 (±0.2)°K, is significantly lower than the -5.9°K obtained with only a product of fij, and agrees with the -6.84°K estimated from a Monte Carlo integration of the many-body Schrödinger equation. The proposed wave function is simple enough to be useful in Fermi liquids.

V. R. Pandharipande

1978-07-01T23:59:59.000Z

59

Variational integrators for the dynamics of thermo-elastic solids with finite speed thermal waves  

E-Print Network (OSTI)

This paper formulates variational integrators for finite element discretizations of deformable bodies with heat conduction in the form of finite speed thermal waves. The cornerstone of the construction consists in taking advantage of the fact that the Green-Naghdi theory of type II for thermo-elastic solids has a Hamiltonian structure. Thus, standard techniques to construct variational integrators can be applied to finite element discretizations of the problem. The resulting discrete-in-time trajectories are then consistent with the laws of thermodynamics for these systems: for an isolated system, they exactly conserve the total entropy, and nearly exactly conserve the total energy over exponentially long periods of time. Moreover, linear and angular momenta are also exactly conserved whenever the exact system does. For definiteness, we construct an explicit second-order accurate algorithm for affine tetrahedral elements in two and three-dimensions, and demonstrate its performance with numerical examples.

Pablo Mata A; Adrian J Lew

2014-03-15T23:59:59.000Z

60

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

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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

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.


61

Fluid Statics When the fluid velocity is zero, called the hydrostatic condition, the pressure variation is due only to the  

E-Print Network (OSTI)

and zdirections can be calculated. The total net force vector, due to pressure, is: Notice that the termFluid Statics When the fluid velocity is zero, called the hydrostatic condition, the pressure the element is at rest, summation of all forces must equal zero. 0 0 1 2 From geometry, . After

Bahrami, Majid

62

Anisotropy of elastic moduli, P-wave velocities, and thermal conductivities of Asan Gneiss, Boryeong Shale, and Yeoncheon Schist in Korea  

Science Journals Connector (OSTI)

This paper presents the anisotropic characteristics of the elastic moduli, P-wave velocities, and thermal conductivities of three types of anisotropic rocks, i.e., Asan gneiss, Boryeong shale, and Yeoncheon schist, occurring in Korea. The experiments were conducted on rock samples that show clear evidence of transverse isotropy. Cylindrical core samples with different anisotropy angles were prepared by coring at 15-degree intervals from the transversely isotropic plane using the laboratory directional coring system established for this study. Elastic moduli, P-wave velocities, and thermal conductivities were determined along the sample axis for different anisotropy angles. The anisotropy ratio is defined as the ratio of the properties parallel to the transversely isotropic plane to those perpendicular to the plane, and the anisotropy ratios for the thermal conductivities (K(90°)/K(0°)) of Asan gneiss, Boryeong shale, and Yeoncheon schist were 1.4, 2.1, and 2.5, respectively. The P-wave velocity anisotropy ratios (VP(90°)/VP(0°)) for Asan gneiss, Boryeong shale, and Yeoncheon schist were 1.2, 1.5, and 2.3, respectively. The elastic moduli, P-wave velocities, and thermal conductivities that were obtained were compared with theoretical predictions by mean prediction error (MPE). The correlations between the measured properties were evidently correlated with some minor scatter in the data. The degree of anisotropy measured in this study suggests that ignoring anisotropy in rock properties may mislead to erroneous results. The application of tensorial transformation evaluations revealed that the three types of rocks chosen for this study can be modeled effectively by a transversely isotropic model.

Hanna Kim; Jung-Woo Cho; Insun Song; Ki-Bok Min

2012-01-01T23:59:59.000Z

63

Downhole Measurements of Shear- and Compression-Wave Velocities in Boreholes C4993, C4996, C4997 and C4998 at the Waste Treatment Plant DOE Hanford Site.  

SciTech Connect

This report describes the procedures and the results of a series of downhole measurements of shear- and compression-wave velocities performed as part of the Seismic Boreholes Project at the site of the Waste Treatment Plant (WTP). The measurements were made in several stages from October 2006 through early February 2007. Although some fieldwork was carried out in conjunction with the University of Texas at Austin (UT), all data acquired by UT personnel are reported separately by that organization.

Redpath, Bruce B.

2007-04-27T23:59:59.000Z

64

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

65

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

Science Journals Connector (OSTI)

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

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

2014-01-01T23:59:59.000Z

66

Heteroclinic standing waves in defocussing DNLS equations -- Variational approach via energy minimization  

E-Print Network (OSTI)

We study heteroclinic standing waves (dark solitons) in discrete nonlinear Schr\\"{o}dinger equations with defocussing nonlinearity. Our main result is a quite elementary existence proof for waves with monotone and odd profile, and relies on minimizing an appropriately defined energy functional. We also study the continuum limit and the numerical approximation of standing waves.

Michael Herrmann

2010-02-08T23:59:59.000Z

67

Mapping Large-Scale Gaseous Outflows in Ultraluminous Galaxies with Keck II ESI Spectra: Variations in Outflow Velocity with Galactic Mass  

E-Print Network (OSTI)

Measurements of interstellar absorption lines in 18 ultraluminous infrared galaxies (ULIGs) have been combined with published data, in order to reassess the dependence of galactic outflow speeds on starburst luminosity and galactic mass. The Doppler shifts reveal outflows of relatively cool gas at $330 \\pm 100$km/s. The outflow speeds increase with the star formation rate (SFR) as roughly $v \\propto SFR^{0.35}$. This result is surprising since, in the traditional model for starburst-driven winds, these relatively cool gas clouds are accelerated by the ram pressure of a hot, supernova-heated wind that exhibits weak (if any) \\x temperature variation with increasing galactic mass. The lack of evidence for much hotter winds is partly a sensitivity issue; but the outflow velocities in ultraluminous starbursts actually are consistent with acceleration by the tepid wind, indicating a hotter component is unlikely to dominate the momentum flux. The \

Crystal L. Martin

2004-10-09T23:59:59.000Z

68

A study of gravity wave induced pressure variations in the presence of a submerged cylinder  

E-Print Network (OSTI)

11 5 Recorder Calibration For A Water Depth of 28 Inches 13 6 Sample Oscillograph Record 16 7 Comparison of Wave Pressure for Three Wave Lengths 23 8 Comparison of Wave Pressure at Different Cylinder Depths 24-25 9 Comparison of Wave Pressure... of sufficiently small height A p = P ft ? 2.9 With no cylinder present, it follows from 2*6 that ( A p ) ^ = p Ao* cosh k(y + d) sin (kx - crt) ? 2*10 In view of relation 2*14 below, relation 2*11 as applied at the bottom (y = - d) reduces to ( A p...

Ellis, Roy

2013-10-04T23:59:59.000Z

69

The Standing Wave on a String as an Oscillator  

Science Journals Connector (OSTI)

In the usual treatment of waves in introductory courses one begins with traveling waves and the frequency/wavelength relationship f??=?v where v is the wave velocity. One then makes the point about superposition and shows that two waves traveling in opposite directions can add up to a standing wave; Eq. (1) still applies. This approach is problematic in two ways: (1) The motion being described standing waves has no apparent “velocity ” and so it seems unnecessarily complex—perhaps unreasonably complex—to construct it out of moving waves; (2) It is not easy to derive the formula for the velocity of waves especially for an audience without calculus or without multi-variate calculus (the wave equation).

Michael Sobel

2007-01-01T23:59:59.000Z

70

detonation velocity  

Science Journals Connector (OSTI)

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

2014-08-01T23:59:59.000Z

71

Rogue waves for a long wave-short wave resonance model with multiple short waves  

E-Print Network (OSTI)

1 Rogue waves for a long wave-short wave resonance model with multiple short waves Hiu Ning Chan (1 waves; Long-short resonance PACS Classification: 02.30.Jr; 05.45.Yv; 47.35.Fg #12;2 ABSTRACT A resonance between long and short waves will occur if the phase velocity of the long wave matches the group velocity

72

Variation of Langmuir wave polarization with electron beam speed in type III radio bursts  

SciTech Connect

Observations by the twin STEREO spacecraft of in-situ electric field waveforms and radio signatures associated with type III radio bursts have demonstrated that the polarization of electron beam-driven waves near the local plasma frequency depends strongly on the speed of the driving electron beam. We expand upon a previous study by including all radio bursts with in-situ waveforms observed by STEREO in 2011. The expanded data set contains five times more radio bursts (35 up from 7) and three times as many Langmuir waves (663 up from 168). While this expanded study supports the results of the original study, that faster (slower) beam electrons drive waves with strong (weak) electric fields perpendicular to the local magnetic field, the larger data set emphasizes that the observation of strong perpendicular electric fields at high electron beam speeds is probabilistic rather than definite. This property supports the interpretation of wave polarization dependence on beam speed as Langmuir/z-mode waves shifted to small wave number through interaction with turbulent solar wind density fluctuations.

Malaspina, David M. [Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303 (United States); Cairns, Iver H. [School of Physics, University of Sydney, New South Wales 2006 (Australia); Ergun, Robert E. [Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303 (United States) and Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80303 (United States)

2013-06-13T23:59:59.000Z

73

2011 Waves -1 STANDING WAVES  

E-Print Network (OSTI)

-multiple of the wavelength: n 2 L ,n 1,2,... . A vibrating string is an example of a transverse wave: its oscillation2011 Waves - 1 STANDING WAVES ON A STRING The objectives of the experiment are: · To show that standing waves can be set up on a string. · To determine the velocity of a standing wave. · To understand

Glashausser, Charles

74

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

75

GLOBAL SEMIGROUP OF CONSERVATIVE SOLUTIONS OF THE NONLINEAR VARIATIONAL WAVE EQUATION  

E-Print Network (OSTI)

. The equation can be derived from the variational principle applied to the functional u2 t - c2 (u)u2 x dxdt. We is given by E(t) = R(u2 t +c2u2 x)(t, x) dx. However, as energy may focus in isolated points, one has

76

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

77

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

78

The various manifestations of collisionless dissipation in wave propagation  

SciTech Connect

The propagation of an electrostatic wave packet inside a collisionless and initially Maxwellian plasma is always dissipative because of the irreversible acceleration of the electrons by the wave. Then, in the linear regime, the wave packet is Landau damped, so that in the reference frame moving at the group velocity, the wave amplitude decays exponentially with time. In the nonlinear regime, once phase mixing has occurred and when the electron motion is nearly adiabatic, the damping rate is strongly reduced compared to the Landau one, so that the wave amplitude remains nearly constant along the characteristics. Yet, we show here that the electrons are still globally accelerated by the wave packet, and in one dimension, this leads to a non local amplitude dependence of the group velocity. As a result, a freely propagating wave packet would shrink, and therefore, so would its total energy. In more than one dimension, not only does the magnitude of the group velocity nonlinearly vary, but also its direction. In the weakly nonlinear regime, when the collisionless damping rate is still significant compared to its linear value, the group velocity is directed towards the outside of the wave packet and tends to increase its transverse extent, while the opposite is true once the wave is essentially undamped. The impact of the nonlinear variation of the group velocity on the transverse size of the wave packet is quantified, and compared to that induced by the self-focussing due to wave front bowing.

Benisti, Didier; Morice, Olivier; Gremillet, Laurent [CEA, DAM, DIF, F-91297 Arpajon (France)

2012-06-15T23:59:59.000Z

79

Waves  

E-Print Network (OSTI)

Waves is the supporting document to the Master of Fine Arts thesis exhibition of the same title. Exhibited March 7-12 2010 in the Art and Design Gallery at the University of Kansas, Waves was comprised of a series of mixed media drawings...

LaCure, Mari Mae

2010-04-29T23:59:59.000Z

80

Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume II P-Wave Measurements in Borehole C4996 Seismic Records, Wave-Arrival Identifications and Interpreted P-Wave Velocity Profile.  

SciTech Connect

In this volume (II), all P-wave measurements are presented that were performed in Borehole C4996 at the Waste Treatment Plant (WTP) with T-Rex as the seismic source and the Lawrence Berkeley National Laboratory (LBNL) 3-D wireline geophone as the at-depth borehole receiver. P-wave measurements were performed over the depth range of 360 to 1400 ft, typically in 10-ft intervals. However, in some interbeds, 5-ft depth intervals were used, while below about 1180 ft, depth intervals of 20 ft were used. Compression (P) waves were generated by moving the base plate of T-Rex for a given number of cycles at a fixed frequency as discussed in Section 2. This process was repeated so that signal averaging in the time domain was performed using 3 to about 15 averages, with 5 averages typically used. In addition to the LBNL 3-D geophone, called the lower receiver herein, a 3-D geophone from Redpath Geophysics was fixed at a depth of 22 ft in Borehole C4996, and a 3-D geophone from the University of Texas was embedded near the borehole at about 1.5 ft below the ground surface. This volume is organized into 12 sections as follows: Section 1: Introduction, Section 2: Explanation of Terminology, Section 3: Vp Profile at Borehole C4996, Sections 4 to 6: Unfiltered P-wave records of lower vertical receiver, reaction mass, and reference receiver, Sections 7 to 9: Filtered P-wave signals of lower vertical receiver, reaction mass and reference receiver, Section 10: Expanded and filtered P-wave signals of lower vertical receiver, and Sections 11 and 12: Waterfall plots of unfiltered and filtered lower vertical receiver signals.

Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R.; Menq, Farn-Yuh

2007-07-06T23:59:59.000Z

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81

Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume I P-Wave Measurements in Borehole C4993 Seismic Records, Wave-Arrival Identifications and Interpreted P-Wave Velocity Profile.  

SciTech Connect

In this volume (I), all P-wave measurements are presented that were performed in Borehole C4993 at the Waste Treatment Plant (WTP) with T-Rex as the seismic source and the Lawrence Berkeley National Laboratory (LBNL) 3-D wireline geophone as the at-depth borehole receiver. P-wave measurements were performed over the depth range of 370 to 1400 ft, typically in 10-ft intervals. However, in some interbeds, 5-ft depth intervals were used, while below about 1200 ft, depth intervals of 20 ft were used. Compression (P) waves were generated by moving the base plate of T-Rex for a given number of cycles at a fixed frequency as discussed in Section 2. This process was repeated so that signal averaging in the time domain was performed using 3 to about 15 averages, with 5 averages typically used. In addition to the LBNL 3-D geophone, called the lower receiver herein, a 3-D geophone from Redpath Geophysics was fixed at a depth of 22 ft in Borehole C4993, and a 3-D geophone from the University of Texas was embedded near the borehole at about 1.5 ft below the ground surface. This volume is organized into 12 sections as follows: Section 1: Introduction, Section 2: Explanation of Terminology, Section 3: Vp Profile at Borehole C4993, Sections 4 to 6: Unfiltered P-wave records of lower vertical receiver, reaction mass, and reference receiver, Sections 7 to 9: Filtered P-wave signals of lower vertical receiver, reaction mass and reference receiver, Section 10: Expanded and filtered P-wave signals of lower vertical receiver, and Sections 11 and 12: Waterfall plots of unfiltered and filtered lower vertical receiver signals.

Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R.; Menq, Farn-Yuh

2007-07-06T23:59:59.000Z

82

Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume III P-Wave Measurements in Borehole C4997 Seismic Records, Wave-Arrival Identifications and Interpreted P-Wave Velocity Profile.  

SciTech Connect

In this volume (III), all P-wave measurements are presented that were performed in Borehole C4997 at the Waste Treatment Plant (WTP) with T-Rex as the seismic source and the Lawrence Berkeley National Laboratory (LBNL) 3-D wireline geophone as the at-depth borehole receiver. P-wave measurements were performed over the depth range of 390 to 1220 ft, typically in 10-ft intervals. However, in some interbeds, 5-ft depth intervals were used. Compression (P) waves were generated by moving the base plate of T-Rex for a given number of cycles at a fixed frequency as discussed in Section 2. This process was repeated so that signal averaging in the time domain was performed using 3 to about 15 averages, with 5 averages typically used. In addition to the LBNL 3-D geophone, called the lower receiver herein, a 3-D geophone from Redpath Geophysics was fixed at a depth of 40 ft (later relocated to 27.5 ft due to visibility in borehole after rain) in Borehole C4997, and a 3-D geophone from the University of Texas was embedded near the borehole at about 1.5 ft below the ground surface. This volume is organized into 12 sections as follows: Section 1: Introduction, Section 2: Explanation of Terminology, Section 3: Vp Profile at Borehole C4997, Sections 4 to 6: Unfiltered P-wave records of lower vertical receiver, reaction mass, and reference receiver, Sections 7 to 9: Filtered P-wave signals of lower vertical receiver, reaction mass and reference receiver, Section 10: Expanded and filtered P-wave signals of lower vertical receiver, and Sections 11 and 12: Waterfall plots of unfiltered and filtered lower vertical receiver signals.

Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R.; Menq, Farn-Yuh

2007-06-06T23:59:59.000Z

83

Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume IV S-Wave Measurements in Borehole C4993 Seismic Records, Wave-Arrival Identifications and Interpreted S-Wave Velocity Profile.  

SciTech Connect

In this volume (IV), all S-wave measurements are presented that were performed in Borehole C4993 at the Waste Treatment Plant (WTP) with T-Rex as the seismic source and the Lawrence Berkeley National Laboratory (LBNL) 3-D wireline geophone as the at-depth borehole receiver. S-wave measurements were performed over the depth range of 370 to 1300 ft, typically in 10-ft intervals. However, in some interbeds, 5-ft depth intervals were used, while below about 1200 ft, depth intervals of 20 ft were used. Shear (S) waves were generated by moving the base plate of T-Rex for a given number of cycles at a fixed frequency as discussed in Section 2. This process was repeated so that signal averaging in the time domain was performed using 3 to about 15 averages, with 5 averages typically used. In addition, a second average shear wave record was recorded by reversing the polarity of the motion of the T-Rex base plate. In this sense, all the signals recorded in the field were averaged signals. In all cases, the base plate was moving perpendicular to a radial line between the base plate and the borehole which is in and out of the plane of the figure shown in Figure 1.1. The definition of “in-line”, “cross-line”, “forward”, and “reversed” directions in items 2 and 3 of Section 2 was based on the moving direction of the base plate. In addition to the LBNL 3-D geophone, called the lower receiver herein, a 3-D geophone from Redpath Geophysics was fixed at a depth of 22 ft in Borehole C4993, and a 3-D geophone from the University of Texas (UT) was embedded near the borehole at about 1.5 ft below the ground surface. The Redpath geophone and the UT geophone were properly aligned so that one of the horizontal components in each geophone was aligned with the direction of horizontal shaking of the T-Rex base plate. This volume is organized into 12 sections as follows. Section 1: Introduction, Section 2: Explanation of Terminology, Section 3: Vs Profile at Borehole C4993, Sections 4 to 6: Unfiltered S-wave records of lower horizontal receiver, reaction mass, and reference receiver, respectively, Sections 7 to 9: Filtered S-wave signals of lower horizontal receiver, reaction mass and reference receiver, respectively, Section 10: Expanded and filtered S-wave signals of lower horizontal receiver, and Sections 11 and 12: Waterfall plots of unfiltered and filtered lower horizontal receiver signals, respectively.

Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R.; Menq, Farn-Yuh

2007-06-06T23:59:59.000Z

84

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

85

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

86

Velocity determination from velocity spectra  

E-Print Network (OSTI)

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

Yang, Sung Jin

2012-06-07T23:59:59.000Z

87

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

88

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

SciTech Connect

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

Grechka, V.; Tsvankin, I.

2000-02-01T23:59:59.000Z

89

MHD Waves in Astrophysical Plasma  

Science Journals Connector (OSTI)

The dependence of the wave velocities on the angle ? between the undisturbed field B 0 and the wave vector k is clearly demonstrated in a polar diagram—the phase velocity diagram. In Fig.?15.2, th...

Boris V. Somov

2012-01-01T23:59:59.000Z

90

Kinematic inversion for the 2-D horizontal and vertical qP-wave velocities and depths to interfaces applied to the TACT seismic profile, southern Alaska  

Science Journals Connector (OSTI)

......the upper 5 km of the crust is anisotropic. The range of anisotropy for...the rock samples, limestone-anisotropic shale. Since the ray path is velocity-dependent...equation (1986) for limestone-anisotropic shale using the following data (Levin......

E. A. Boztepe; L. W. Braile

1994-11-01T23:59:59.000Z

91

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

92

Investigation of Wave Energy Converter Effects on Wave Fields: A Modeling Sensitivity Study in Monterey Bay CA.  

SciTech Connect

A n indust ry standard wave modeling tool was utilized to investigate model sensitivity to input parameters and wave energy converter ( WEC ) array deploym ent scenarios. Wave propagation was investigated d ownstream of the WECs to evaluate overall near - and far - field effects of WEC arrays. The sensitivity study illustrate d that b oth wave height and near - bottom orbital velocity we re subject to the largest pote ntial variations, each decreas ed in sensitivity as transmission coefficient increase d , as number and spacing of WEC devices decrease d , and as the deployment location move d offshore. Wave direction wa s affected consistently for all parameters and wave perio d was not affected (or negligibly affected) by varying model parameters or WEC configuration .

Roberts, Jesse D.; Grace Chang; Jason Magalen; Craig Jones

2014-08-01T23:59:59.000Z

93

Detonation velocity deficit and curvature radius of flexible detonation fuses  

Science Journals Connector (OSTI)

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

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

2012-03-01T23:59:59.000Z

94

Wave Breaking Dissipation Observed with “SWIFT” Drifters  

Science Journals Connector (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

95

Velocities of Wave-Transmission in Rocks  

Science Journals Connector (OSTI)

...excep- tion the fundamental requirement that...interior- wall of boiler-room. This...the buildings safe for operation and providing...amperes for normal operation. A Laon tube...0.1, the fundamental REPORTS AND PAPERS...

L. H. Adams

96

Effective traveling-wave excitation below the speed of light  

Science Journals Connector (OSTI)

We demonstrate that effective traveling-wave excitation of high-gain amplifiers requires velocities that are remarkably slower than the velocity of light. Experiments with a...

Tommasini, Riccardo; Fill, Ernst E

2001-01-01T23:59:59.000Z

97

Resonant Absorption between Moving Atoms due to Doppler Frequency Shift and Quantum Energy Variation  

E-Print Network (OSTI)

By taking both the Doppler frequency shift for electromagnetic wave and the quantum energy variation of matter wave into consideration, a resonant-absorption condition based on the local-ether wave equation is presented to account for a variety of phenomena consistently, including the Ives-Stilwell experiment, the output frequency from ammonia masers, and the M\\"{o}ssbauer rotor experiment. It is found that in the resonant-absorption condition, the major term associated with the laboratory velocity is a dot-product term between this velocity and that of the emitting or absorbing atom. This term appears both in the Doppler frequency shift and the transition frequency variation and then cancels out. Thereby, the experimental results can be independent of the laboratory velocity and hence comply with Galilean relativity, despite the restriction that the involved velocities are referred specifically to the local-ether frame. However, by examining the resonant-absorption condition in the M\\"{o}ssbauer rotor experiment to a higher order, it is found that Galilean relativity breaks down.

Ching-Chuan Su

2002-08-23T23:59:59.000Z

98

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

99

Studies of the velocity fields near a submerged rectangular object  

E-Print Network (OSTI)

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

Kim, Young-Ki

2012-06-07T23:59:59.000Z

100

Localized parallel parametric generation of spin waves in a Ni{sub 81}Fe{sub 19} waveguide by spatial variation of the pumping field  

SciTech Connect

We present the experimental observation of localized parallel parametric generation of spin waves in a transversally in-plane magnetized Ni{sub 81}Fe{sub 19} magnonic waveguide. The localization is realized by combining the threshold character of parametric generation with a spatially confined enhancement of the amplifying microwave field. The latter is achieved by modulating the width of the microstrip transmission line which is used to provide the pumping field. By employing microfocussed Brillouin light scattering spectroscopy, we analyze the spatial distribution of the generated spin waves and compare it with numerical calculations of the field distribution along the Ni{sub 81}Fe{sub 19} waveguide. This provides a local spin-wave excitation in transversally in-plane magnetized waveguides for a wide wave-vector range which is not restricted by the size of the generation area.

Brächer, T. [Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern (Germany); Graduate School Materials Science in Mainz, Gottlieb-Daimler-Strasse 47, D-67663 Kaiserslautern (Germany); Pirro, P.; Heussner, F.; Serga, A. A.; Hillebrands, B. [Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, D-67663 Kaiserslautern (Germany)

2014-03-03T23:59:59.000Z

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

Localized velocity anomalies in the lower mantle  

Science Journals Connector (OSTI)

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

Thorne Lay

1983-02-01T23:59:59.000Z

102

IWA : an analysis program for isentropic wave measurements.  

SciTech Connect

IWA (Isentropic Wave Analysis) is a program for analyzing velocity profiles of isentropic compression experiments. IWA applies incremental impedance matching correction to measured velocity profiles to obtain in-situ particle velocity profiles for Lagrangian wave analysis. From the in-situ velocity profiles, material properties such as wave velocities, stress, strain, strain rate, and strength are calculated. The program can be run in any current version of MATLAB (2008a or later) or as a Windows XP executable.

Ao, Tommy

2009-02-01T23:59:59.000Z

103

PROPAGATING WAVES ALONG SPICULES  

SciTech Connect

Alfvenic waves are thought to play an important role in coronal heating and acceleration of solar wind. Here we investigate the statistical properties of Alfvenic waves along spicules (jets that protrude into the corona) in a polar coronal hole using high-cadence observations of the Solar Optical Telescope on board Hinode. We developed a technique for the automated detection of spicules and high-frequency waves. We detected 89 spicules and found (1) a mix of upward propagating, downward propagating, as well as standing waves (occurrence rates of 59%, 21%, and 20%, respectively); (2) the phase speed gradually increases with height; (3) upward waves dominant at lower altitudes, standing waves at higher altitudes; (4) standing waves dominant in the early and late phases of each spicule, while upward waves were dominant in the middle phase; (5) in some spicules, we find waves propagating upward (from the bottom) and downward (from the top) to form a standing wave in the middle of the spicule; and (6) the medians of the amplitude, period, and velocity amplitude were 55 km, 45 s, and 7.4 km s{sup -1}, respectively. We speculate that upward propagating waves are produced near the solar surface (below the spicule) and downward propagating waves are caused by reflection of (initially) upward propagating waves off the transition region at the spicule top. The mix of upward and downward propagating waves implies that exploiting these waves to perform seismology of the spicular environment requires careful analysis and may be problematic.

Okamoto, Takenori J. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); De Pontieu, Bart, E-mail: joten.okamoto@nao.ac.jp [Lockheed Martin Solar and Astrophysics Laboratory, B/252, 3251 Hanover Street, Palo Alto, CA 94304 (United States)

2011-08-01T23:59:59.000Z

104

Elastic constants and velocity surfaces of indurated anisotropic shales  

Science Journals Connector (OSTI)

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

Joel E. Johnston; Nikolas I. Christensen

1994-09-01T23:59:59.000Z

105

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...

Ryu, Yong Uk

2009-06-02T23:59:59.000Z

106

LAB #2 Escape Velocity  

E-Print Network (OSTI)

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

2007-02-02T23:59:59.000Z

107

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

108

Optimization of Variational Boussinesq Models  

E-Print Network (OSTI)

Optimization of Variational Boussinesq Models 2 4 6 8 10 2 4 6 8 10 0 0.5 1 1.5 2 1 2 Kapp -Kex 0 of Arts and Sciences). Ivan Lakhturov: Optimization of Variational Boussinesq Models c 2012 Printed Boussinesq Model (VBM). The VBM is a model for waves above a layer of ideal fluid, which conserves mass

Al Hanbali, Ahmad

109

Hysteresis of ionization waves  

SciTech Connect

A quasi-logistic, nonlinear model for ionization wave modes is introduced. Modes are due to finite size of the discharge and current feedback. The model consists of competing coupled modes and it incorporates spatial wave amplitude saturation. The hysteresis of wave mode transitions under current variation is reproduced. Sidebands are predicted by the model and found in experimental data. The ad hoc model is equivalent to a general--so-called universal--approach from bifurcation theory.

Dinklage, A. [Max-Planck-Institut fuer Plasmaphysik, EURATOM-Association, Wendelsteinstr. 1, 17491 Greifswald (Germany); Bruhn, B.; Testrich, H. [Institut fuer Physik, E.-M.-Arndt Universitaet Greifswald, Felix-Hausdorff-Str. 6, 17487 Greifswald (Germany); Wilke, C. [Leibniz-Institut fuer Plasmaforschung und Technologie, Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany)

2008-06-15T23:59:59.000Z

110

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

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

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

113

Lithospheric Thickness Modeled from Long Period Surface Wave Dispersion  

SciTech Connect

The behavior of surface waves at long periods is indicative of subcrustal velocity structure. Using recently published dispersion models, we invert surface wave group velocities for lithospheric structure, including lithospheric thickness, over much of the Eastern Hemisphere, encompassing Eurasia, Africa, and the Indian Ocean. Thicker lithosphere under Precambrian shields and platforms are clearly observed, not only under the large cratons (West Africa, Congo, Baltic, Russia, Siberia, India), but also under smaller blocks like the Tarim Basin and Yangtze craton. In contrast, it is found that remobilized Precambrian structures like the Saharan Shield and Sino-Korean Paraplatform do not have well-established lithospheric keels. The thinnest lithospheric thickness is found under oceanic and continental rifts, as well as along convergence zones. We compare our results to thermal models of continental lithosphere, lithospheric cooling models of oceanic lithosphere, lithosphere-asthenosphere boundary (LAB) estimates from S-wave receiver functions, and velocity variations of global tomography models. In addition to comparing results for the broad region, we examine in detail the regions of Central Africa, Siberia, and Tibet. While there are clear differences in the various estimates, overall the results are generally consistent. Inconsistencies between the estimates may be due to a variety of reasons including lateral and depth resolution differences and the comparison of what may be different lithospheric features.

Pasyanos, M E

2008-05-15T23:59:59.000Z

114

A One-Dimensional Propagation of Shock Wave Supported by Atmospheric Millimeter-Wave Plasma  

Science Journals Connector (OSTI)

A shock wave supported by an atmospheric breakdown plasma caused by a high-power millimeter-wave ... was detached from the ionization front of the plasma whenever the propagation velocity of the ionization ... . ...

Yasuhisa Oda; Toshikazu Yamaguchi…

2011-06-01T23:59:59.000Z

115

Traveling-wave photodetector  

SciTech Connect

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

116

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

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)

1982-01-01T23:59:59.000Z

118

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

119

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

E-Print Network (OSTI)

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

Meju, Max

120

Explosive plane-wave lens  

DOE Patents (OSTI)

An explosive plane-wave air lens which enables a spherical wave form to be converted to a planar wave without the need to specially machine or shape explosive materials is described. A disc-shaped impactor having a greater thickness at its center than around its periphery is used to convert the spherical wave into a plane wave. When the wave reaches the impactor, the center of the impactor moves first because the spherical wave reaches the center of the impactor first. The wave strikes the impactor later in time as one moves radially along the impactor. Because the impactor is thinner as one moves radially outward, the velocity of the impactor is greater at the periphery than at the center. An acceptor explosive is positioned so that the impactor strikes the acceptor simultaneously. Consequently, a plane detonation wave is propagated through the acceptor explosive. 4 figs.

Marsh, S.P.

1988-03-08T23:59:59.000Z

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.


121

Explosive plane-wave lens  

DOE Patents (OSTI)

An explosive plane-wave air lens which enables a spherical wave form to be converted to a planar wave without the need to specially machine or shape explosive materials is described. A disc-shaped impactor having a greater thickness at its center than around its periphery is used to convert the spherical wave into a plane wave. When the wave reaches the impactor, the center of the impactor moves first because the spherical wave reaches the center of the impactor first. The wave strikes the impactor later in time as one moves radially along the impactor. Because the impactor is thinner as one moves radially outward, the velocity of the impactor is greater at the periphery than at the center. An acceptor explosive is positioned so that the impactor strikes the acceptor simultaneously. Consequently, a plane detonation wave is propagated through the acceptor explosive. 3 figs., 3 tabs.

Marsh, S.P.

1987-03-12T23:59:59.000Z

122

Explosive plane-wave lens  

DOE Patents (OSTI)

An explosive plane-wave air lens which enables a spherical wave form to be converted to a planar wave without the need to specially machine or shape explosive materials is described. A disc-shaped impactor having a greater thickness at its center than around its periphery is used to convert the spherical wave into a plane wave. When the wave reaches the impactor, the center of the impactor moves first because the spherical wave reaches the center of the impactor first. The wave strikes the impactor later in time as one moves radially along the impactor. Because the impactor is thinner as one moves radially outward, the velocity of the impactor is greater at the periphery than at the center. An acceptor explosive is positioned so that the impactor strikes the acceptor simultaneously. Consequently, a plane detonation wave is propagated through the acceptor explosive.

Marsh, Stanley P. (Los Alamos, NM)

1988-01-01T23:59:59.000Z

123

Seismic velocity estimation from time migration  

E-Print Network (OSTI)

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

Cameron, Maria Kourkina

2007-01-01T23:59:59.000Z

124

Are "EIT Waves" Fast-Mode MHD Waves?  

E-Print Network (OSTI)

We examine the nature of large-scale, coronal, propagating wave fronts (``EIT waves'') and find they are incongruous with solutions using fast-mode MHD plane-wave theory. Specifically, we consider the following properties: non-dispersive single pulse manifestions, observed velocities below the local Alfven speed, and different pulses which travel at any number of constant velocities, rather than at the ``predicted'' fast-mode speed. We discuss the possibility of a soliton-like explanation for these phenomena, and show how it is consistent with the above-mentioned aspects.

M. J. Wills-Davey; C. E. DeForest; J. O. Stenflo

2007-04-23T23:59:59.000Z

125

Scour of simulated Gulf Coast sand beaches due to wave action in front of sea walls and dune barriers  

E-Print Network (OSTI)

versus the deep water wave height for the two wave lengths and for the 15' and 90' walls. For a particular wave length scour increased with increase in wave height, because of the greater energies and velocities associated with higher waves... were identical, Because the wave lengths differed, the deep water wave heights differed. For longer waves the scour increased at all points where the wall was installed. The greater weve length resulted in greater energy and particle velocities and...

Chesnutt, Charles Burgess

2012-06-07T23:59:59.000Z

126

A MAGNETIC CALIBRATION OF PHOTOSPHERIC DOPPLER VELOCITIES  

SciTech Connect

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

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

2013-03-10T23:59:59.000Z

127

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

128

Energy Flux and Wavelet Diagnostics of Secondary Mountain Waves  

Science Journals Connector (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

129

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

E-Print Network (OSTI)

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

Li, Jianling; Higgins, Andrew J

2014-01-01T23:59:59.000Z

130

Vertical velocity in oceanic convection off tropical Australia  

E-Print Network (OSTI)

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

Lucas, Christopher

2012-06-07T23:59:59.000Z

131

Discrimination of porosity and fluid saturation using seismic velocity analysis  

DOE Patents (OSTI)

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

Berryman, James G. (Danville, CA)

2001-01-01T23:59:59.000Z

132

Stress anisotropy and velocity anisotropy in low porosity shale  

Science Journals Connector (OSTI)

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

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

2011-01-01T23:59:59.000Z

133

Slow waves in fractures filled with viscous fluid Valeri Korneev1  

E-Print Network (OSTI)

Slow waves in fractures filled with viscous fluid Valeri Korneev1 ABSTRACT Stoneley guided waves in a fluid-filled fracture generally have larger amplitudes than other waves; therefore, their properties, a simple dispersion equa- tion for wave-propagation velocity is obtained. This velocity is much smaller

Korneev, Valeri A.

134

Radial disk heating by more than one spiral density wave  

E-Print Network (OSTI)

We consider a differentially rotating, 2D stellar disk perturbed by two steady state spiral density waves moving at different patterns speeds. Our investigation is based on direct numerical integration of initially circular test-particle orbits. We examine a range of spiral strengths and spiral speeds and show that stars in this time dependent gravitational field can be heated (their random motions increased). This is particularly noticeable in the simultaneous propagation of a 2-armed spiral density wave near the corotation resonance (CR), and a weak 4-armed one near the inner and outer 4:1 Lindblad resonances. In simulations with 2 spiral waves moving at different pattern speeds we find: (1) the variance of the radial velocity, sigma_R^2, exceeds the sum of the variances measured from simulations with each individual pattern; (2) sigma_R^2 can grow with time throughout the entire simulation; (3) sigma_R^2 is increased over a wider range of radii compared to that seen with one spiral pattern; (4) particles diffuse radially in real space whereas they don't when only one spiral density wave is present. Near the CR with the stronger, 2-armed pattern, test particles are observed to migrate radially. These effects take place at or near resonances of both spirals so we interpret them as the result of stochastic motions. This provides a possible new mechanism for increasing the stellar velocity dispersion in galactic disks. If multiple spiral patterns are present in the Galaxy we predict that there should be large variations in the stellar velocity dispersion as a function of radius.

I. Minchev; A. C. Quillen

2005-10-28T23:59:59.000Z

135

TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES...  

Open Energy Info (EERE)

TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES IN THE COSO GEOTHERMAL FIELD FROM ANALYSES OF SHEAR-WAVE SPLITTING Jump to: navigation, search OpenEI Reference...

136

Measurements and Linear Wave Theory Based Simulations of Vegetated Wave Hydrodynamics for Practical Applications  

E-Print Network (OSTI)

density exceeding some threshold where maximum wave attenuation capabilities are exceeded and lowering of damping ensues. Additionally, wave attenuation increased with higher stem spatial variation due to less wake sheltering. A one-dimensional model...

Anderson, Mary Elizabeth

2011-10-21T23:59:59.000Z

137

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

138

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

139

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

140

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

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

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

142

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

143

Unitaxial constant velocity microactuator  

DOE Patents (OSTI)

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

McIntyre, T.J.

1994-06-07T23:59:59.000Z

144

SHORT TIMESCALE VARIATIONS IN THE ATMOSPHERE OF ANTARES A  

SciTech Connect

We analyze three years of high-resolution spectroscopic data and find radial velocity variations with a characteristic timescale of 100 ± 6 days that are nearly sinusoidal. Simultaneous variations in line-depth ratios imply temperature variations of up to 100 K. No photometric variation is seen on a 100 day timescale. The timescale of the variation and its resonant nature suggest solar-like oscillations driven by large-scale convection.

Pugh, T.; Gray, David F., E-mail: tpugh@uwo.ca [Department of Physics and Astronomy, Western University, London, ON (Canada)

2013-11-01T23:59:59.000Z

145

A Reconsideration of Matter Waves  

E-Print Network (OSTI)

Matter waves were discovered in the early 20th century from their wavelength, predicted by DeBroglie, Planck's constant divided by the particle's momentum, that is, lmw = h/mv. But, the failure to obtain a reasonable theory for the matter wave frequency resulted somewhat in loss of further interest. It was expected that the frequency of the matter wave should correspond to the particle kinetic energy, that is, fmw = 1/2mv^2/h but the resulting velocity of the matter of the particle, v = fmw x lmw, is that the matter wave moves at one half the speed of the particle, obviously absurd as the particle and its wave must move together. If relativistic mass is used (as it should in any case) the problem remains, the same mass appearing in numerator and denominator and canceling. It is no help to hypothesize that the total energy, not just the kinetic energy, yields the matter wave. That attributes a matter wave to a particle at rest. It also gives the resulting velocity as c^2/v, the wave racing ahead of its particle. A reinterpretation of Einstein's derivation of relativistic kinetic energy (which produced his famous E = mc^2) leads to a valid matter wave frequency and a new understanding of particle kinetics and of the atom's stable orbits.

Roger Ellman

2005-05-16T23:59:59.000Z

146

Irregular Magnetic Fields in Interstellar Clouds and Variations in the Observed Circular Polarization of Spectral Lines  

E-Print Network (OSTI)

The strengths of magnetic fields in interstellar gas clouds are obtained through observations of the circular polarization of spectral line radiation. Irregularities in this magnetic field may be present due to turbulence, waves or perhaps other causes, and may play an essential role in the structure and evolution of the gas clouds. To infer information about these irregularities from the observational data, we develop statistical relationships between the rms values of the irregular component of the magnetic field and spatial variations in the circular polarization of the spectral line radiation. The irregularities are characterized in analogy with descriptions of turbulence---by a sum of Fourier waves having a power spectrum with a slope similar to that of Kolmogorov turbulence. For comparison, we also perform computations in which turbulent magnetic and velocity fields from representative MHD simulations by others are utilized. Although the effects of the variations about the mean value of the magnetic field along the path of a ray tend to cancel, a significant residual effect in the polarization of the emergent radiation remains for typical values of the relevant parameters. A map of observed spectra of the 21 cm line toward Orion A is analyzed and the results are compared with our calculations in order to infer the strength of the irregular component of the magnetic field. The rms of the irregular component is found to be comparable in magnitude to the mean magnetic field within the cloud. Hence, the turbulent and Alfven velocities should also be comparable.

W. D. Watson; D. S. Wiebe; R. M. Crutcher

2000-10-13T23:59:59.000Z

147

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

148

Energy Dispersion in African Easterly Waves  

Science Journals Connector (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

149

Wave energy  

Science Journals Connector (OSTI)

Waves receive their energy from the wind by means of a ... whose yield is not yet clearly understood. Energy in the wave is more concentrated than in the wind ... density. For this reason a motor utilizing wave p...

Ferruccio Mosetti

1982-01-01T23:59:59.000Z

150

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

151

Alfv'en Wave Solitons and Solar Intermediate Drift Bursts  

E-Print Network (OSTI)

propagate at velocities of the order of the Alfv'en veloc­ ity in a direction inclined to the magnetic field, the solar wind, and possibly accretion disks, and extra­ galactic jets. In such magnetized plasmas Alfv'en waves are easily excited by various processes. Linear waves propagate at the Alfv'en speed v

Guedel, Manuel

152

Seismic waves in stratified anisotropic media  

Science Journals Connector (OSTI)

......structure response as a function of frequency and radial...group, and energy velocities...structure response as a function of frequency and radial...group, and energy velocities...plane-wave response. This method...for each frequency, data for...amounts of storage required......

Gerard J. Fryer; L. Neil Frazer

1984-09-01T23:59:59.000Z

153

Liu UCD Phy9B 07 1 Ch15. Mechanical Waves  

E-Print Network (OSTI)

Liu UCD Phy9B 07 1 Ch15. Mechanical Waves #12;Liu UCD Phy9B 07 2 15-1. Introduction Source: disturbance + cohesive force between adjacent pieces A wave is a disturbance that propagates through space Mechanical wave: needs a medium to propagate Wave pulse #12;Liu UCD Phy9B 07 3 Distinctions Wave velocity vs

Yoo, S. J. Ben

154

Kinematics measurements of regular, irregular, and rogue waves by PIV/LDV  

E-Print Network (OSTI)

waves. A series of experiments were conducted in a 2-D wave tank at Texas A&M University to measure wave velocities and accelerations using LDV and PIV systems. The wave crests of regular and rogue waves are the focus of this study. With the measured...

Choi, Hae-Jin

2007-04-25T23:59:59.000Z

155

Velocity of Elastic Waves in Granite and Norite  

Science Journals Connector (OSTI)

...excep- tion the fundamental requirement that...interior- wall of boiler-room. This...the buildings safe for operation and providing...amperes for normal operation. A Laon tube...0.1, the fundamental REPORTS AND PAPERS...

L. Don Leet

156

Crust and Upper Mantle P Wave Velocity Structure Beneath Valles...  

Open Energy Info (EERE)

Structure Beneath Valles Caldera, New Mexico- Results from the Jemez Teleseismic Tomography Experiment Jump to: navigation, search OpenEI Reference LibraryAdd to library...

157

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

158

Fermi velocity renormalization and dynamical gap generation in graphene  

E-Print Network (OSTI)

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

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

2015-01-12T23:59:59.000Z

159

Comparison of P-wave and S-wave data in a fractured reservoir  

E-Print Network (OSTI)

-wave and S-wave stations . Table 2 The depths, times, and RMS velocities of the seismic reflectors (Tertiary and Cretaceous systems) at locations 45, 0 and 65. 0 on the P-wave section . 32 Table 3 The RMS velocities, depths of the seismic reflectors...-wave seismic lines were shot, parallel to each other, in Burleson County, Texas. The circles indicate ~ oil-producing wells. The two lines trend northwest-southeast and are appmximately thee and a half miles long (Fig. 2) The contours represent cumulative...

Al-Mustafa, Husam Mustafa

2012-06-07T23:59:59.000Z

160

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

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

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

162

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 +

163

Trapping and Frequency Variability in Electron Acoustic Waves  

E-Print Network (OSTI)

Trapping and Frequency Variability in Electron Acoustic Waves C.F. Driscoll, F. Anderegg, D 92093 USA Abstract. Electron Acoustic Waves (EAWs) with a phase velocity less than twice the plasma Langmuir waves, and at large excitations resonance is observed over a broad range. Laser Induced

California at San Diego, University of

164

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

Science Journals Connector (OSTI)

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

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

1994-06-13T23:59:59.000Z

165

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

166

Penetration and scattering of lower hybrid waves by density fluctuations  

SciTech Connect

Lower Hybrid [LH] ray propagation in toroidal plasma is controlled by a combination of the azimuthal spectrum launched from the antenna, the poloidal variation of the magnetic field, and the scattering of the waves by the density fluctuations. The width of the poloidal and radial RF wave spectrum increases rapidly as the rays penetrate into higher density and scatter from the turbulence. The electron temperature gradient [ETG] spectrum is particularly effective in scattering the LH waves due to its comparable wavelengths and parallel phase velocities. ETG turbulence is also driven by the radial gradient of the electron current density giving rise to an anomalous viscosity spreading the LH-driven plasma currents. The scattered LH spectrum is derived from a Fokker-Planck equation for the distribution of the ray trajectories with a diffusivity proportional to the fluctuations. The LH ray diffusivity is large giving transport in the poloidal and radial wavenumber spectrum in one - or a few passes - of the rays through the core plasma.

Horton, W. [Institute for Fusion Studies, University of Texas at Austin (United States); Goniche, M.; Peysson, Y.; Decker, J.; Ekedahl, A.; Litaudon, X. [CEA, IRFM, F-13108 St-Paul-Lez-Durance (France)

2014-02-12T23:59:59.000Z

167

Direct numerical investigation of detonation waves using a Monte Carlo method.  

E-Print Network (OSTI)

??A detonation wave describes a shock that propagates at supersonic velocity through a chemically unstable gas medium and is driven by the energy released by… (more)

O'Connor, Patrick

2008-01-01T23:59:59.000Z

168

Ultrasonic guided waves in eccentric annular pipes  

SciTech Connect

This paper studies the feasibility of using ultrasonic guided waves to rapidly inspect tubes and pipes for possible eccentricity. While guided waves are well established in the long range inspection of structures such as pipes and plates, studies for more complex cross sections are limited and analytical solutions are often difficult to obtain. Recent developments have made the Semi Analytical Finite Element (SAFE) method widely accessible for researchers to study guided wave properties in complex structures. Here the SAFE method is used to study the effect of eccentricity on the modal structures and velocities of lower order guided wave modes in thin pipes of diameters typically of interest to the industry. Results are validated using experiments. The paper demonstrates that even a small eccentricity in the pipe can strongly affect guided wave mode structures and velocities and hence shows potential for pipe eccentricity inspection.

Pattanayak, Roson Kumar; Balasubramaniam, Krishnan; Rajagopal, Prabhu [Centre for NDE, Indian Institute of Technology - Madras Chennai 600036, T. N. (India)

2014-02-18T23:59:59.000Z

169

Seismic Shear Waves in Deep Seismic Reflection Surveys: Some Notes on Problems and Profits  

Science Journals Connector (OSTI)

—Shear (S) waves differ from compressional (P) waves because of their lower propagation velocities, their lower frequencies and due to the different character of their particle motion. The move-out of travel-time...

E. Lüschen

1999-09-01T23:59:59.000Z

170

Quantitative imaging of the air-water flow fields formed by unsteady breaking waves  

E-Print Network (OSTI)

An experimental method for simultaneously measuring the velocity fields on the air and water side of unsteady breaking waves is presented. The method is applied to breaking waves to investigate the physics of the air and ...

Belden, Jesse (Jesse Levi)

2009-01-01T23:59:59.000Z

171

Guided Wave Propagation in Tubular Section with Multi-Layered Viscoelastic Coating  

E-Print Network (OSTI)

. The dispersion of phase velocity and wave attenuation for coated pipes are evaluated against a baseline model which is the bare, uncoated tubing to establish the propagation characteristics of the guided shear and longitudinal waves in the presence of multiple...

Kuo, Chi-Wei 1982-

2012-11-16T23:59:59.000Z

172

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

173

Original articles: Intelligent multichannel sensors for pulse wave analysis  

Science Journals Connector (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

174

Zones of T-wave excitation in the NE Indian ocean mapped using variations in backazimuth over time obtained from multi-channel correlation of IMS hydrophone triplet data  

Science Journals Connector (OSTI)

......detection is coded in grey shades (light grey 0 to black 1). The...bathymetric features such as Christmas Island more than 3 south of...wave is also observed from the Christmas Island area. The corresponding...reflections from Java, from Christmas Island and from a seamount......

Frank M. Graeber; Pierre-Franck Piserchia

2004-07-01T23:59:59.000Z

175

APRIL 2006 MOUM ET. AL. 1 Energy Transport by Nonlinear Internal Waves  

E-Print Network (OSTI)

APRIL 2006 MOUM ET. AL. 1 Energy Transport by Nonlinear Internal Waves J. N. MOUM1 , J. M. KLYMAK2. The energy transported by these waves includes a nonlinear advection term uE that is negligible in linear internal waves. Unlike linear internal waves, the pressure-velocity energy flux up includes important

176

SEPTEMBER 2006 MOUM ET. AL. 1 Energy Transport by Nonlinear Internal Waves  

E-Print Network (OSTI)

SEPTEMBER 2006 MOUM ET. AL. 1 Energy Transport by Nonlinear Internal Waves J. N. MOUM1 , J. M of coastline. The energy transported by these waves includes a nonlinear advection term uE that is negligible in linear internal waves. Unlike linear internal waves, the pressure-velocity energy flux up includes

177

Renormalization of trial wave functionals using the effective potential  

Science Journals Connector (OSTI)

We introduce a procedure for renormalizing trial variational wave functionals in Fermi and Bose field theories in terms of zero-momentum n-point functions. The method relies on a variational calculation of the effective potential. Two model field theories, ??4 and g?¯??, are treated explicitly with simple trial wave functionals for the Fermi and Bose vacuums.

Ted Barnes and G. I. Ghandour

1980-08-15T23:59:59.000Z

178

wave energy  

Science Journals Connector (OSTI)

wave energy ? Wellenenergie f [Die einer Schwerewelle innewohnende potentielle und kinetische Energie. Sie ist etwa proportional dem Quadrat der Wellenhöhe. Zeichen: E we ...

2014-08-01T23:59:59.000Z

179

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

SciTech Connect

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

Rohay, Alan C.; Brouns, Thomas M.

2007-06-27T23:59:59.000Z

180

A note on the effects of nonuniform spreading velocity of submarine slumps and slides on the near-eld tsunami amplitudes  

E-Print Network (OSTI)

A note on the effects of nonuniform spreading velocity of submarine slumps and slides on the near Accepted 9 February 2002 Abstract The effects of variable speeds of spreading of submarine slides slides and slumps must consider time variations in the spreading velocities, when these velocities

Southern California, University of

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181

Body-wave radiation patterns and AVO in transversely isotropic media  

SciTech Connect

It is well known that the angular dependence of reflection coefficients may be significantly distorted in the presence of elastic anisotropy. However, the influence of anisotropy on amplitude-versus-offset analysis (AVO) is not limited to reflection coefficients. AVO signatures (e.g., AVO gradient) in anisotropic media are also distorted by the redistribution of energy along the wavefront of the wave travelling down to the reflector and back up to the surface. Significant anisotropy above the target horizon may be rather typical of sand-shale sequences commonly encountered in AVO analysis. Here, I examine the influence of P- and S-wave radiation patterns on AVO in the most common anisotropic model - transversely isotropic media. A concise analytic solution, obtained in the weak-anisotropy approximation, provides a convenient way to estimate the impact of the distortions of the radiation patterns on AVO results. It is shown that the shape of the P-wave radiation pattern in the range of angles most important to AVO analysis (0 - 40{degrees}) is mostly dependent on the difference between Thomsen parameters {epsilon} and {beta}. For media with {epsilon} - {beta} > 0 (the most common case), the P-wave amplitude may drop substantially over the first 25{degrees} - 40{degrees} from vertical. There is no simple correlation between the strength of velocity anisotropy and angular amplitude variations: for instance, for models with a fixed positive {epsilon} - {beta} the amplitude distortions are less pronounced for larger anisotropies {epsilon} and {beta}. The distortions of the SV-wave radiation pattern are usually much more significant than those for the P-wave. The anisotropic directivity factor for the incident wave may be of equal or greater importance for AVO than the influence of anisotropy on the reflection coefficient.

Tsvankin, I.

1994-03-01T23:59:59.000Z

182

BENCAP, LLC: CAPSULE VELOCITY TEST  

SciTech Connect

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

Meidinger, Brian

2005-09-07T23:59:59.000Z

183

Vacuum Waves  

E-Print Network (OSTI)

As an example of the unification of gravitation and particle physics, an exact solution of the five-dimensional field equations is studied which describes waves in the classical Einstein vacuum. While the solution is essentially 5D in nature, the waves exist in ordinary 3D space, and may provide a way to test for an extra dimension.

Paul S. Wesson

2012-12-11T23:59:59.000Z

184

Energy density of variational states  

Science Journals Connector (OSTI)

We show, in several important and general cases, that a low variational energy density of a trial state is possible even when the trial state represents a different phase from the ground state. Specifically, we ask whether the ground-state energy density of a Hamiltonian whose ground state is in phase A can be approximated to arbitrary accuracy by a wave function, which represents a different phase B. We show this is indeed the case when A has discrete symmetry breaking order in one dimension or topological order in two dimensions, while B is disordered. We argue that, if reasonable conditions of physicality are imposed upon the trial wave function, then this is not possible when A has discrete symmetry breaking in dimensions greater than one and B is symmetric. Some other situations are also discussed.

Leon Balents

2014-12-08T23:59:59.000Z

185

High-Frequency Internal Waves on the Oregon Continental Shelf  

Science Journals Connector (OSTI)

Measurements of vertical velocity by isopycnal-following, neutrally buoyant floats deployed on the Oregon shelf during the summers of 2000 and 2001 were used to characterize internal gravity waves on the shelf using measurements of vertical ...

Eric A. D’Asaro; Ren-Chieh Lien; Frank Henyey

2007-07-01T23:59:59.000Z

186

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

187

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

188

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

189

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

190

Wave-particle interaction and Hamiltonian dynamics investigated in a traveling wave tube  

SciTech Connect

For wave-particle interaction studies, the one-dimensional (1-D) beam-plasma system can be advantageously replaced by a Traveling Wave Tube (TWT). This led us to a detailed experimental analysis of the self-consistent interaction between unstable waves and a small either cold or warm beam. More recently, a test electron beam has been used to observe its non-self-consistent interaction with externally excited wave(s). The velocity distribution function of the electron beam is investigated with a trochoidal energy analyzer that records the beam energy distribution at the output of the TWT. An arbitrary waveform generator is used to launch a prescribed spectrum of waves along the slow wave structure (a 4 m long helix) of the TWT. The nonlinear synchronization of particles by a single wave responsible for Landau damping is observed. The resonant velocity domain associated to a single wave is also observed, as well as the transition to large-scale chaos when the resonant domains of two waves and their secondary resonances overlap leading to a typical 'devil's staircase' behavior. A new strategy for the control of chaos is tested.

Doveil, Fabrice; Macor, Alessandro [Physique des Interactions Ioniques et Moleculaires, Unite 6633 CNRS-Universite de Provence, Equipe Turbulence Plasma, Case 321, Centre de Saint-Jerome, F-13397 Marseille cedex 20 (France)

2006-05-15T23:59:59.000Z

191

Bending waves due to a moving harmonic force.  

Science Journals Connector (OSTI)

In many structurally induced and flow?induced vibration problems the harmonic forcing function is not stationary but moves with a velocity V 0. The effect of the forcing function velocity V 0 upon the free vibrational wave?number characteristics of a membrane and a plate is analyzed. The Mach numberM is defined to be the ratio of the velocity V 0 to the wave speed of the bending waves. For the membrane the effect of the Mach number is to increase the wave number (shorter wavelength) ahead of the forcing function and to decrease the wave number (longer wavelength) behind it. At supersonic speeds no disturbances travel ahead of the forcing function and both wave numbers lead to trailing waves. These results are equivalent to the classical Doppler?shifted results. The results of the plate are more complex. The right and left traveling waves retain their basic properties with the magnitude of the wave number changing monotomically as a function of the Mach numberM. The near?field decaying disturbances also retain their basic properties but immediately obtain components that induce the decaying disturbances to become left traveling waves with decaying components. At Mach numbers greater than 2 these disturbances become pure waves trailing without any decaying factor. The importance of each of these components as a function of the Mach number is discussed.

Mauro Pierucci

1992-01-01T23:59:59.000Z

192

Compressional-wave and shear-wave velocities from long-spaced sonic waveforms  

E-Print Network (OSTI)

-SPACED SONIC TOOL UT LTF R L TNR 3' Lr TN R LrTFR LT 10' C FR NR 8' D I FRI (( 'I ll NrR ) ( rt I ll ))8. I ) 8 I I I I ) I I I l I I I-I Ii& I ? ? +) ? +l ?? I I~ I lk ) I LT I ? I I 10' A LT Figure 2. Configuration... REFERENCES 56 VITA 58 LIST OF TABLES TABLE Page I Input parameters for synthetic sonic waveforms. 23 2 Synthetic waveform computed slowness error ? 9"-diameter borehole. . . . 25 3 Synthetic waveform computed slowness error ? 4"-diameter borehole...

Lake, Leonard Cornelius

2012-06-07T23:59:59.000Z

193

Measuring In-Situ Mdf Velocity Of Detonation  

DOE Patents (OSTI)

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

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

2005-10-25T23:59:59.000Z

194

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)

195

Newberry EGS Seismic Velocity Model  

DOE Data Explorer (OSTI)

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

Dennise Templeton

196

Newberry EGS Seismic Velocity Model  

SciTech Connect

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

Dennise Templeton

2013-10-01T23:59:59.000Z

197

Estimating wave energy from a wave record  

Science Journals Connector (OSTI)

This note is concerned with the calculation of wave energy from a time series record of wave heights. Various methods are used to estimate the wave energy. For wave records that contain a number of different ... ...

Sasithorn Aranuvachapun; John A. Johnson

1977-01-01T23:59:59.000Z

198

Coherence waves  

Science Journals Connector (OSTI)

In 1955 Wolf noticed that the mutual coherence function ? obeys two wave equations [Proc. R. Soc. London230, 246 (1955)]. The physical optics of this finding is thoroughly presented in...

Lohmann, Adolf W; Mendlovic, David; Shabtay, Gal

1999-01-01T23:59:59.000Z

199

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

200

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

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

Radial velocities and binarity of southern SIM grid stars  

E-Print Network (OSTI)

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

Makarov, Valeri V

2014-01-01T23:59:59.000Z

202

Investigation of Wave Energy Converter Effects on Near-shore Wave Fields: Model Generation Validation and Evaluation - Kaneohe Bay HI.  

SciTech Connect

The numerical model, SWAN (Simulating WAves Nearshore) , was used to simulate wave conditions in Kaneohe Bay, HI in order to determine the effects of wave energy converter ( WEC ) devices on the propagation of waves into shore. A nested SWAN model was validated then used to evaluate a range of initial wave conditions: significant wave heights (H s ) , peak periods (T p ) , and mean wave directions ( MWD) . Differences between wave height s in the presence and absence of WEC device s were assessed at locations in shore of the WEC array. The maximum decrease in wave height due to the WEC s was predicted to be approximately 6% at 5 m and 10 m water depths. Th is occurred for model initiation parameters of H s = 3 m (for 5 m water depth) or 4 m (10 m water depth) , T p = 10 s, and MWD = 330deg . Subsequently, bottom orbital velocities were found to decrease by about 6%.

Roberts, Jesse D.; Chang, Grace; Jones, Craig

2014-09-01T23:59:59.000Z

203

Wave represents displacement Wave represents pressure Source -Sound Waves  

E-Print Network (OSTI)

Wave represents displacement Wave represents pressure Source - Sound Waves Distance between crests is wavelength Number of crests passing a point in 1 second is frequency Wave represents pressure Target - Radio Waves Distance between crests is wavelength Number of crests passing a point in 1 second is frequency

Colorado at Boulder, University of

204

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

E-Print Network (OSTI)

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

205

Group-velocity tomography of South America and the surrounding oceans  

E-Print Network (OSTI)

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

Ritzwolle, Mike

206

Numerical modelling of MHD waves in the solar chromosphere  

Science Journals Connector (OSTI)

...waves and oscillations in the solar plasma organized by Robert Erdelyi...exploration of the properties of the solar chromosphere will have to rely...waves and oscillations in the solar plasma. Figure 1 (a) Magnetic...horizontal). The other three panels show the velocity times the...

2006-01-01T23:59:59.000Z

207

Kinematics of Turbulence Convected by a Random Wave Field  

Science Journals Connector (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

208

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

Science Journals Connector (OSTI)

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

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

2002-07-01T23:59:59.000Z

209

Dispersion of Rayleigh Waves across Australia  

Science Journals Connector (OSTI)

......deformation ; there are considerable sedimentary basins of Paleozoic and Upper Proterozoic age...the wave fronts near the Great Australian Bight. A number of theoretical group velocity...A., 1962. The crust of the Pacific Basin, Geophys. Monograph No. 6, Brune......

B. A. Bolt; M. Niazi

1964-10-01T23:59:59.000Z

210

Long Wave/Short Wave Resonance in Equatorial Waves  

Science Journals Connector (OSTI)

It is shown that resonant coupling between ultra long equatorial Rossby waves and packets of either short Rossby or short westward-traveling gravity waves is possible. Simple analytic formulas give the discrete value of the packet wave number k, ...

John P. Boyd

1983-03-01T23:59:59.000Z

211

Electromagnetic waves with nonlinear dispersion law  

E-Print Network (OSTI)

Last year physicists in Europe have measured the velocity of the neutrinos particles. They found the neutrinos moving faster than the speed of light in vacuum. This result means that Einstein's relativity principle and its consequences in modern physics need a global additional renovation. In present paper the part of this problem is considered in terms of basic Maxwell's method only. By means of introduction a diffusion like displacement current the new super wave equation was derived, which permits of its solution be described the electromagnetic waves moving some faster than the conventional speed of light in vacuum especially in a gamma ray of a very short wave length region. The unique properties of these waves are that they undergo nonlinear dispersion law, uppermost limit of which is restricted. Discussion of further experimental problems and a number of estimations are given for the macro physic super wave equations also.

Pavel Mednis

2012-02-08T23:59:59.000Z

212

Wave–wave interactions and deep ocean acoustics  

Science Journals Connector (OSTI)

Deep ocean acoustics in the absence of shipping and wildlife is driven by surface processes. Best understood is the signal generated by non-linear surface wave interactions the Longuet-Higgins mechanism which dominates from 0.1 to 10?Hz and may be significant for another octave. For this source the spectral matrix of pressure and vector velocity is derived for points near the bottom of a deep ocean resting on an elastic half-space. In the absence of a bottom the ratios of matrix elements are universal constants. Bottom effects vitiate the usual “standing wave approximation ” but a weaker form of the approximation is shown to hold and this is used for numerical calculations. In the weak standing wave approximation the ratios of matrix elements are independent of the surface wave spectrum but depend on frequency and the propagation environment. Data from the Hawaii-2 Observatory are in excellent accord with the theory for frequencies between 0.1 and 1?Hz less so at higher frequencies. Insensitivity of the spectral ratios to wind and presumably waves is indeed observed in the data.

Z. Guralnik; J. Bourdelais; X. Zabalgogeazcoa; W. E. Farrell

2013-01-01T23:59:59.000Z

213

Reverse Doppler effect of magnons with negative group velocity scattered from a moving Bragg grating  

Science Journals Connector (OSTI)

We demonstrate experimentally and theoretically the reverse Doppler effect when magnons with negative group velocity are reflected off a moving Bragg grating. This grating, which represents a moving magnonic crystal, is created in an yttrium-iron-garnet film by the periodic strain induced by a traveling surface acoustic wave. As reflection occurs from a crystal rather than from a single reflecting surface, the wave number of the scattered wave is strictly determined by a momentum conservation law. Magnons scattered from the approaching (receding) magnonic crystal are found to be shifted down (up) in frequency. This result, together with an earlier report of reverse Doppler shift from moving sources [D. D. Stancil et al., Phys. Rev. B, 74, 060404(R) (2006)], establishes that the reverse Doppler effect is a universal phenomenon in systems with negative group velocity and not restricted to left-handed materials.

A. V. Chumak; P. Dhagat; A. Jander; A. A. Serga; B. Hillebrands

2010-04-16T23:59:59.000Z

214

The Velocity of Sound in an Absorptive Gas  

Science Journals Connector (OSTI)

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

D. G. Bourgin

1932-12-01T23:59:59.000Z

215

Vortices in Brain waves  

E-Print Network (OSTI)

2003). Vortices in Brain Waves 62. M. E. Raichle, ScienceVORTICES IN BRAIN WAVES WALTER J. FREEMAN Department ofthat is recorded in brain waves (electroencephalogram, EEG).

Freeman, Walter J III; Vitiello, Giuseppe

2010-01-01T23:59:59.000Z

216

Large-amplitude circularly polarized electromagnetic waves in magnetized plasma  

SciTech Connect

We consider large-amplitude circularly polarized (LACP) waves propagating in a magnetized plasma. It is well-known that the dispersion relation for such waves coincides with the dispersion relation given by the linear theory. We develop the model of LACP wave containing a finite population of Cerenkov resonant particles. We find that the current of resonant particles modifies the linear dispersion relation. Dispersion curves of low-frequency (i.e., whistler and magnetosonic) waves are shifted toward larger values of the wave vector, i.e., waves with arbitrarily large wavelengths do not exist in this case. Dispersion curves of high-frequency waves are modified so that the wave phase velocity becomes smaller than the speed of light.

Vasko, I. Y., E-mail: vaskoiy@gmail.com; Artemyev, A. V.; Zelenyi, L. M. [Space Research Institute, RAS, Moscow (Russian Federation)] [Space Research Institute, RAS, Moscow (Russian Federation)

2014-05-15T23:59:59.000Z

217

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

SciTech Connect

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

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

2013-02-01T23:59:59.000Z

218

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

219

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

SciTech Connect

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

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

2013-09-09T23:59:59.000Z

220

Electromagnetic Energy Velocity in Slow Light  

Science Journals Connector (OSTI)

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

Santagiustina, Marco

Note: This page contains sample records for the topic "wave velocity variations" from the National Library of EnergyBeta (NLEBeta).
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221

Experimental and numerical studies of high-velocity impact fragmentation  

SciTech Connect

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

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

1993-08-01T23:59:59.000Z

222

U-shaped slope gully systems and sediment waves on the passive margin of Gabon (West Africa)  

Science Journals Connector (OSTI)

Abstract 3-D seismic reflection data has enabled the documentation of a system of remarkable modern and buried u-shaped gullies which intimately co-exist with upslope migrating sediment waves along 80 km of the Gabon continental slope. The modern gullies occur on a silty mud-dominated slope in water depths of 150–1500 m on an ~ 50 km wide slope with a gradient of 4.5° decreasing to 1.5°. The gully sets persist laterally for distances of at least 40 km and extend downslope for distances of up to 60 km. The gullies are u-shaped in cross-section, with a relief of 5–30 m, and widths of 50–400 m. Intriguingly, the gullies become narrower and shallower with distance down the slope, as well as increasing in number down slope. The majority of the gullies appear to be erosional but some appear to have resulted from simultaneous aggradation along inter-gully ridges and non-deposition along the adjacent gully floor. Hence, these gullies are interpreted to have formed mainly in response to spatially-variable deposition, rather than erosion. Upslope migrating sediment waves occur in close proximity to the gullies. Gullies cross fields of sediment waves and waves are observed to migrate up-slope locally within both the erosional and aggradational gullies. Evidence is lacking for any slumping or headward erosion in the headwall region of the gullies, which discounts formation by very local sediment gravity flows originating from shelf-edge collapse, as has been observed in other v-shaped gully systems. Based on our new data, and supported by theoretical studies on the mechanics of turbidity currents, we propose that the gullies and related sediment waves were formed by diffuse, sheet-like, mud-rich turbidity currents that presumably originated on the shelf. Instabilities in the turbidity currents generated a wave-shaped perturbation in a cross-flow direction leading to regularly spaced regions of faster and slower flow. For the non-aggradational and erosional gullies it is inferred that gully axes experienced flow velocities that mainly exceeded the settling velocity of the sediment in suspension, and thus no deposition occurred. In contrast, the aggradational gullies indicate lower flow velocities with sediment deposition both within the gully axes and on the gully flanks. Mixed mode gullies are also found which indicate that successive flows can experience variations in flow properties leading to interspersed erosional and depositional events.

Lidia Lonergan; Nur Huda Jamin; Christopher A.-L. Jackson; Howard D. Johnson

2013-01-01T23:59:59.000Z

223

Internal Waves and Tidal Conversion from a Finite Submarine Ridge  

E-Print Network (OSTI)

. The ocean, due to the constantly varying density gradient, effectively has a long boundary gradient across waves. In a density stratified fluid, which in the ocean is caused by variations in salinity

Morrison, Philip J.,

224

Velocity distributions in clusters of galaxies  

E-Print Network (OSTI)

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

A. Faltenbacher; J. Diemand

2006-02-08T23:59:59.000Z

225

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

E-Print Network (OSTI)

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

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

2009-03-14T23:59:59.000Z

226

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

227

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

228

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,

229

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

230

Effects of ion abundances on electromagnetic ion cyclotron wave growth rate in the vicinity of the plasmapause  

SciTech Connect

Electromagnetic ion cyclotron (EMIC) waves in multi-ion species plasmas propagate in branches. Except for the branch corresponding to the heaviest ion species, which has only a resonance at its gyrofrequency, these branches are bounded below by a cutoff frequency and above by a resonant gyrofrequency. The condition for wave growth is determined by the thermal anisotropies of each ion species, j, which sets an upper bound, ?{sub j}{sup ?}, on the wave frequency below which that ion species contributes positively to the growth rate. It follows that the relative positions of the cutoffs and the critical frequencies ?{sub j}{sup ?} play a crucial role in determining whether a particular wave branch will be unstable. The effect of the magnetospheric ion abundances on the growth rate of each branch of the EMIC instability in a model where all the ion species have kappa velocity distributions is investigated by appealing to the above ideas. Using the variation of the cutoff frequencies predicted by cold plasma theory as a guide, optimal ion abundances that maximise the EMIC instability growth rate are sought. When the ring current is comprised predominantly of H{sup +} ions, all branches of the EMIC wave are destabilised, with the proton branch having the maximum growth rate. When the O{sup +} ion abundance in the ring current is increased, a decrease in the growth rate of the proton branch and cyclotron damping of the helium branch are observed. The oxygen branch, on the other hand, experiences an increase in the maximum growth rate with an increase in the O{sup +} ion abundance. When the ring current is comprised predominantly of He{sup +} ions, only the helium and oxygen branches of the EMIC wave are destabilised, with the helium branch having the maximum growth rate.

Henning, F. D., E-mail: farranalfonso@gmail.com; Mace, R. L., E-mail: macer@ukzn.ac.za [School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000 (South Africa)

2014-04-15T23:59:59.000Z

231

Influence of orographic and canopy conditions on friction velocities observed during frontal events using Doppler sodar observations  

SciTech Connect

Sodar friction velocities, obtained during frontal events traversing areas characterized by different orographic and canopy conditions (flat, bare ground, small hills and valleys with agricultural crops and trees, agricultural crops and forest on a flat ground, bare ground on the side of a mountain), are compared in order to identify the influence of topography on this parameter. For some case studies, sounding and sodar data are combined in order to provide a relation between the friction velocity and the low-level jet presence. For the cases analyzed in this paper, the following results are obtained: the frontal passage is associated with a decrease of the horizontal wind speed (about 50% in magnitude) in the surface layer, and an increase of the friction velocity before the frontal passage followed by a decrease just at the time of the frontal passage or with a little delay. Friction velocity is more intense in the cold side of the low-level jet and its maximum represents 2% of the low-level jet maximum magnitude. As it concerns the influence of the terrain conditions on friction velocity, mountain effects yield to more intense friction-velocity values and to a superposition of an oscillating behavior on the time variation of friction velocity, while forest effects induce a shift of the frontal signature on the time variation of friction velocity at higher height levels. 25 refs., 18 figs., 3 tabs.

Kotroni, V.; Amory-Mazaudier, C. (CRPE, Saint-Maur des Fosses (France))

1993-03-01T23:59:59.000Z

232

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

233

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

234

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

235

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

236

Kink waves in solar spicules: observation and modelling  

E-Print Network (OSTI)

Height series of Doppler observation at the solar limb (covering 3800 - 8700 km distance above the photosphere) in $H_{\\alpha}$ spectral line obtained by big coronagraph of Abastumani Astrophysical Observatory \\citep{khu} show the periodic spatial distribution of Doppler velocities in spicules. We suggest that the periodic spatial distribution is caused by propagating kink waves in spicule. The wave length is found to be $\\sim$ 3500 km. Numerical modelling of kink wave propagation from the photosphere to observed heights gives the wave length of kink waves at the photosphere to be $\\sim$ 1000 km, which indicates to the granular origin of the waves. The period of waves is estimated to be in the range of 35-70 s.

V. Kukhianidze; T. V. Zaqarashvili; E. Khutsishvili

2005-10-14T23:59:59.000Z

237

Waves in Plasmas  

SciTech Connect

Quadratic corrections to the metaplectic formulation of mode conversions. In this work we showed how to systematically deal with quadratic corrections beyond the usual linearization of the dispersion matrix at a conversion. The linearization leads to parabolic cylinder functions as the local approximation to the full-wave behavior, but these do not include the variation in amplitude associated with ray refraction in the neighborhood of the conversion. Hence, the region over which they give a good fit to the incoming and outgoing WKB solutions is small. By including higher order corrections it is possible to provide a much more robust matching. We also showed that it was possible, in principle, to extend these methods to arbitrary order. A new normal form for mode conversion. This is based upon our earlier NSF-DOE-funded work on ray helicity. We have begun efforts to apply these new ideas in practical ray tracing algorithms. Group theoretical foundation of path integrals and phase space representations of wave problems. Using the symbol theory of N. Zobin, we developed a new understanding of path integrals on phase space. The initial goal was to find practical computational tools for dealing with non-standard mode conversions. Along the way we uncovered a new way to represent wave functions directly on phase space without the intermediary of a Wigner function. We are exploring the use of these ideas for numerical studies of conversion, with the goal of eventually incorporating kinetic effects. Wave packet studies of gyroresonance crossing. In earlier work, Huanchun Ye and Allan Kaufman -- building upon ideas due to Lazar Friedland -- had shown that gyroresonance crossings could be treated as a double conversion. This perspective is one we have used for many of our papers since then. We are now performing a detailed numerical comparison between full-wave and ray tracing approaches in the study of minority-ion gyroresonance crossing. In this study, a fast magnetosonic wave -- supported by a majority-ion species such as deuterium -- crosses the resonance layer associated with a minority species, such as hydrogen. By using wave packets instead of harmonic solutions, it becomes easy to see the evolution in k-space of the minority-ion disturbance, and the time delay for emission of the reflected fast-wave packet. Iterated conversion in a cavity. When mode conversion occurs in a cavity where rays are trapped, multiple conversions will occur and the resulting absorption profile will typically have a complicated spatial dependence due to overlapping interference patterns. The goal of this work is to develop fast and efficient ray-based methods for computing the cavity response to external driving, and to compute the spatial absorption profile. We have introduced a new approach that allows us to visualize in great detail the underlying iterated ray geometry, and should lead to simpler methods for identifying parameter values where global changes occur in the qualitative response (e.g. global bifurcations).

Tracy, Eugene R

2009-09-21T23:59:59.000Z

238

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

239

Nonlinear extraordinary wave in dense plasma  

SciTech Connect

Conditions for the propagation of a slow extraordinary wave in dense magnetized plasma are found. A solution to the set of relativistic hydrodynamic equations and Maxwell’s equations under the plasma resonance conditions, when the phase velocity of the nonlinear wave is equal to the speed of light, is obtained. The deviation of the wave frequency from the resonance frequency is accompanied by nonlinear longitudinal-transverse oscillations. It is shown that, in this case, the solution to the set of self-consistent equations obtained by averaging the initial equations over the period of high-frequency oscillations has the form of an envelope soliton. The possibility of excitation of a nonlinear wave in plasma by an external electromagnetic pulse is confirmed by numerical simulations.

Krasovitskiy, V. B., E-mail: krasovit@mail.ru [Russian Academy of Sciences, Keldysh Institute of Applied Mathematics (Russian Federation); Turikov, V. A. [Russian University of Peoples’ Friendship (Russian Federation)] [Russian University of Peoples’ Friendship (Russian Federation)

2013-10-15T23:59:59.000Z

240

An investigation of the relationships between mountain waves and clear air turbulence encountered by the XB-70 airplane in the stratosphere  

E-Print Network (OSTI)

. . . . . . . . , . . . ~ . ~ INTRODUCTION BACKGROUND TO THE PROBLEM Theory of Mountain Waves Mountain Waves and Clear Air Turbulence (CAT). Page iv v vi viii The Vertical Propagation and Transfer of Energy of Mountain Waves into the Stratosphere The Influence of Wind... and wave energy under the influence of wind shear (Booker and Bretherton, 1967). A critical level, if it exists, is the level at which the horizontal phase velocity of the wave equals the mean wind speed. If a wave passes through a criti- cal level...

Incrocci, Thomas Paul

2012-06-07T23:59:59.000Z

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

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

242

Wave Energy Converter Effects on Wave Fields: Evaluation of SNL-SWAN and Sensitivity Studies in Monterey Bay CA.  

SciTech Connect

A modified version of an indust ry standard wave modeling tool was evaluated, optimized, and utilized to investigate model sensitivity to input parameters a nd wave energy converter ( WEC ) array deployment scenarios. Wave propagation was investigated d ownstream of the WECs to evaluate overall near - and far - field effects of WEC arrays. The sensitivity study illustrate d that wave direction and WEC device type we r e most sensitive to the variation in the model parameters examined in this study . Generally, the changes in wave height we re the primary alteration caused by the presence of a WEC array. Specifically, W EC device type and subsequently their size directly re sult ed in wave height variations; however, it is important to utilize ongoing laboratory studies and future field tests to determine the most appropriate power matrix values for a particular WEC device and configuration in order to improve modeling results .

Roberts, Jesse D.; Chang, Grace; Magalen, Jason; Jones, Craig

2014-09-01T23:59:59.000Z

243

Dependence of synergy current driven by lower hybrid wave and electron cyclotron wave on the frequency and parallel refractive index of electron cyclotron wave for Tokamaks  

SciTech Connect

The physical mechanism of the synergy current driven by lower hybrid wave (LHW) and electron cyclotron wave (ECW) in tokamaks is investigated using theoretical analysis and simulation methods in the present paper. Research shows that the synergy relationship between the two waves in velocity space strongly depends on the frequency ? and parallel refractive index N{sub //} of ECW. For a given spectrum of LHW, the parameter range of ECW, in which the synergy current exists, can be predicted by theoretical analysis, and these results are consistent with the simulation results. It is shown that the synergy effect is mainly caused by the electrons accelerated by both ECW and LHW, and the acceleration of these electrons requires that there is overlap of the resonance regions of the two waves in velocity space.

Huang, J.; Chen, S. Y., E-mail: sychen531@163.com; Tang, C. J. [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China) [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China)

2014-01-15T23:59:59.000Z

244

Variations ia Variscan Granites  

Science Journals Connector (OSTI)

... the compositional variations within the Caledonian belt, may both be attributed to variations in the geothermal gradient. In Nature Physical Science this week (April 2), he takes these studies ... studies a stage further by showing that the correlation within the belt between composition and geothermal gradient also applies to the Variscan granites.

1973-04-06T23:59:59.000Z

245

Modeling velocity dispersion In Gypsy site, Oklahoma  

E-Print Network (OSTI)

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

Alsaadan, Sami Ibrahim

2010-01-01T23:59:59.000Z

246

Steady magnetic-field generation via surface-plasma-wave excitation  

SciTech Connect

The possibility of inducing a magnetic field via surface plasma-wave excitation is investigated with a simple nonrelativistic hydrodynamic model. A static magnetic field is predicted at the plasma surface, scaling with the square of the surface-wave field amplitude, and the influence of the electron plasma density is studied. In the case of resonant surface-wave excitation by laser this result can be applied to low intensities such that the electron quiver velocity in the field of the surface wave is less than its thermal velocity.

Bigongiari, A.; Raynaud, M.; Riconda, C. [CEA/DSM/LSI, CNRS, Ecole Polytechnique, F-91128 Palaiseau Cedex, France and TIPS/LULI, Universite Paris 6, CNRS, CEA, Ecole Polytechnique, 3, rue Galilee, F-94200, Ivry-sur-Seine (France); CEA/DSM/LSI, CNRS, Ecole Polytechnique, F-91128 Palaiseau Cedex (France); TIPS/LULI, Universite Paris 6, CNRS, CEA, Ecole Polytechnique, 3, rue Galilee, F-94200, Ivry-sur-Seine (France)

2011-07-15T23:59:59.000Z

247

Acoustic measurement of potato cannon velocity  

E-Print Network (OSTI)

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

Courtney, M; Courtney, Amy; Courtney, Michael

2006-01-01T23:59:59.000Z

248

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

249

Modulation of whistler waves in nonthermal plasmas  

SciTech Connect

The modulation of whistler waves in nonthermal plasmas is investigated. The dynamics of the magnetized plasma is described by the fluid equations and the electron velocity distribution function is modeled via a nonthermal {kappa} distribution. A multiscale perturbation analysis based on the Krylov-Bogoliubov-Mitropolsky method is carried out and the nonlinear Schroedinger equation governing the modulation of the high-frequency whistler is obtained. The effect of the superthermal electrons on the stability of the wave envelope and soliton formation is discussed and a comparison with previous results is presented.

Rios, L. A.; Galvao, R. M. O. [Centro Brasileiro de Pesquisas Fisicas and Instituto Nacional de Ciencia e Tecnologia de Sistemas Complexos, Rua Xavier Sigaud 150, 22290-180 Rio de Janeiro (Brazil)

2011-02-15T23:59:59.000Z

250

Plane waves Lumped systems  

E-Print Network (OSTI)

1 Impedance · Plane waves ­ Lumped systems S x y z Impedance · Plane waves ­ Lumped systems · open tube #12;2 Impedance · Plane waves ­ Lumped systems · closed tube Impedance · Cylindrical waves z x y r #12;3 Impedance · Cylindrical waves ­ Circumferential part n=0 n=1 n=2 n=3 Impedance · Cylindrical

Berlin,Technische Universität

251

Slow wave structures using twisted waveguides for charged particle applications  

DOE Patents (OSTI)

A rapidly twisted electromagnetic accelerating structure includes a waveguide body having a central axis, one or more helical channels defined by the body and disposed around a substantially linear central axial channel, with central portions of the helical channels merging with the linear central axial channel. The structure propagates electromagnetic waves in the helical channels which support particle beam acceleration in the central axial channel at a phase velocity equal to or slower than the speed of light in free space. Since there is no variation in the shape of the transversal cross-section along the axis of the structure, inexpensive mechanical fabrication processes can be used to form the structure, such as extrusion, casting or injection molding. Also, because the field and frequency of the resonant mode depend on the whole structure rather than on dimensional tolerances of individual cells, no tuning of individual cells is needed. Accordingly, the overall operating frequency may be varied with a tuning/phase shifting device located outside the resonant waveguide structure.

Kang, Yoon W.; Fathy, Aly E.; Wilson, Joshua L.

2012-12-11T23:59:59.000Z

252

Explicit dispersion relations for elastic waves in extremely deformed soft matter with application to nearly incompressible and auxetic materials  

E-Print Network (OSTI)

We analyze the propagation of elastic waves in soft materials subjected to finite deformations. We derive explicit dispersion relations, and apply these results to study elastic wave propagation in (i) nearly incompressible materials such as biological tissues and polymers, and (ii) negative Poisson's ratio or auxetic materials. We find that for nearly incompressible materials transverse wave velocities exhibit strong dependence on direction of propagation and initial strain state, whereas the longitudinal component is not affected significantly until extreme levels of deformations are attained. For highly compressible materials, we show that both pressure and shear wave velocities depend strongly on initial deformation and direction of propagation. When compression is applied, longitudinal wave velocity decreases in positive bulk modulus materials, and increases for negative bulk modulus materials; this is regardless the direction of wave prorogation. We demonstrate that finite deformations influence elastic wave propagation through combinations of induced effective compressibility and stiffness.

Pavel Galich; Stephan Rudykh

2014-12-31T23:59:59.000Z

253

Investigation of Spatial Variation of Sea States Offshore of Humboldt Bay CA Using a Hindcast Model.  

SciTech Connect

Spatial variability of sea states is an important consideration when performing wave resource assessments and wave resource characterization studies for wave energy converter (WEC) test sites and commercial WEC deployments. This report examines the spatial variation of sea states offshore of Humboldt Bay, CA, using the wave model SWAN . The effect of depth and shoaling on bulk wave parameters is well resolved using the model SWAN with a 200 m grid. At this site, the degree of spatial variation of these bulk wave parameters, with shoaling generally perpendicular to the depth contours, is found to depend on the season. The variation in wave height , for example, was higher in the summer due to the wind and wave sheltering from the protruding land on the coastline north of the model domain. Ho wever, the spatial variation within an area of a potential Tier 1 WEC test site at 45 m depth and 1 square nautical mile is almost negligible; at most about 0.1 m in both winter and summer. The six wave characterization parameters recommended by the IEC 6 2600 - 101 TS were compared at several points along a line perpendicular to shore from the WEC test site . As expected, these parameters varied based on depth , but showed very similar seasonal trends.

Dallman, Ann Renee; Neary, Vincent Sinclair

2014-10-01T23:59:59.000Z

254

Variational Calculation with Harmonic-Oscillator Eigenfunctions  

Science Journals Connector (OSTI)

Variational calculations play an important role in quantum mechanics particularly in determining the ground-state energy of physical systems. Didactic examples in which one can see how the exact energy and wave function are approached by using a family of trial functions are not very numerous. An example was given in a recent book [M. Moshinsky The Harmonic Oscillator in Modern Physics: From Atoms to Quarks (Gordon and Breach New York 1969)] which discusses the ground state of the hydrogen atom using as trial wave function a linear combination of harmonic-oscillator states. In the present paper we carry out a similar analysis for the ground state of a particle of mass m in a three-dimensional square-well potential. We discuss not only the approach to the exact energy when we vary the frequency and the number of oscillator states but also analyze the overlap of the exact and variational wave functions and compare the exact and approximate form factors.

V. C. Aguilera-Navarro; R. M. Méndez V.

1971-01-01T23:59:59.000Z

255

Numerical experiments of fracture-induced velocity and attenuation anisotropy  

Science Journals Connector (OSTI)

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

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

2012-12-01T23:59:59.000Z

256

Nonlinear hydromagnetic waves in a thermally stratified spherical shell: Exact toroidal field solutions  

SciTech Connect

The propagation of nonlinear hydromagnetic waves in a highly conducting, self-gravitating fluid in a spherical geometry, subject to the convective forces produced by a radial temperature gradient, is treated in a Boussinesq approximation. Exact wave solutions of the nonlinear magnetohydrodynamic equations (in the Boussinesq approximation) in the presence of convective forces are obtained for the toroidal velocity and magnetic fields. The solution represents waves propagating along the mean magnetic field with the velocity depending on the mean magnetic (or velocity) field strength and the strength of stratification, under the influence of the azimuthal magnetic and velocity fields and convective forces. The solutions may be applicable to the hydromagnetic waves in the Earth's core and the solar convection zone.

Hamabata, H. (Department of Physics, Faculty of Science, Osaka City University, Osaka 558 (Japan))

1994-08-01T23:59:59.000Z

257

Observations and modeling of wave-acceleration-induced sediment transport in the surfzone  

E-Print Network (OSTI)

Onshore sediment transport and sandbar migration are important to the morphological evolution of beaches, but are not understood well. Here, a new model that accounts for accelerations of wave-orbital velocities predicts ...

Hoefel, Fernanda Gemael, 1973-

2004-01-01T23:59:59.000Z

258

Modeling fault-zone guided waves of microearthquakes in a geothermal...  

Open Energy Info (EERE)

the identification and modeling of such guided waves is an effective tool to locate fracture-induced, low-velocity fault-zone structures in geothermal fields. Authors Lou, M.;...

259

E-Print Network 3.0 - averaged teleseismic p-wave Sample Search...  

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

Zone: A joint teleseismic and local P tomographic study Summary: because the unconsolidated sediment layer has a very low P wave velocity (1.8 kmsec) Chiu et al., 1992......

260

Observations on the Energy Balance of Internal Waves during JASIN [and Discussion  

Science Journals Connector (OSTI)

...research-article Observations on the Energy Balance of Internal Waves during JASIN [and Discussion...variation at one site of internal wave energy over a 40 day period during...wavefield, and the internal wave energy 11 days later. The Royal Society...

1983-01-01T23:59:59.000Z

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.


261

Barometric pressure variations associated with eastern Pacific tropical instability waves  

E-Print Network (OSTI)

with the life cycle of deep convective mixing, i.e., 8-12 hours (Bretherton et al. 1995). Likewise, sounding, USA. E-mail: cronin@pmel.noaa.gov. #12;2 Abstract. Barometric pressure, surface temperature and wind difference also had a spectral peak in the 20-30 day TIW band. Cross- spectral analysis shows that within

Xie, Shang-Ping

262

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

SciTech Connect

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

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

2010-10-15T23:59:59.000Z

263

Instabilities of a circularly polarized wave with trapped particles in an isotropic plasma  

SciTech Connect

The structure and stability of a transverse electromagnetic wave propagating with a velocity lower than the speed of light in an unmagnetized plasma are considered. The stationary finite-amplitude wave is described by exact solutions to the Vlasov-Maxwell equations. However, unlike the well-known electrostatic analog, the Bernstein-Greene-Kruskal wave, the wave structure is determined to a large extent by the presence of trapped particles with a shear of transverse velocities, without which the existence of waves with a refraction index larger than unity is impossible. It is shown that the main origin of the wave instability is the longitudinal motion of trapped particles relative to the background plasma. Expressions for the growth rates in the main instability regimes are found under definite restrictions on the wave parameters.

Krasovsky, V. L., E-mail: vkrasov@iki.rssi.ru [Russian Academy of Sciences, Space Research Institute (Russian Federation)

2013-04-15T23:59:59.000Z

264

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

SciTech Connect

To test the hypothesis that high quality 3D Earth models will produce seismic event locations which are more accurate and more precise, we are developing a global 3D P wave velocity model of the Earth's crust and mantle using seismic tomography. In this paper, we present the most recent version of our model, SALSA3D (SAndia LoS Alamos) version 1.4, and demonstrate its ability to reduce mislocations for a large set of realizations derived from a carefully chosen set of globally-distributed ground truth events. Our model is derived from the latest version of the Ground Truth (GT) catalog of P and Pn travel time picks assembled by Los Alamos National Laboratory. To prevent over-weighting due to ray path redundancy and to reduce the computational burden, we cluster rays to produce representative rays. Reduction in the total number of ray paths is > 55%. The model is represented using the triangular tessellation system described by Ballard et al. (2009), which incorporates variable resolution in both the geographic and radial dimensions. For our starting model, we use a simplified two layer crustal model derived from the Crust 2.0 model over a uniform AK135 mantle. Sufficient damping is used to reduce velocity adjustments so that ray path changes between iterations are small. We obtain proper model smoothness by using progressive grid refinement, refining the grid only around areas with significant velocity changes from the starting model. At each grid refinement level except the last one we limit the number of iterations to prevent convergence thereby preserving aspects of broad features resolved at coarser resolutions. Our approach produces a smooth, multi-resolution model with node density appropriate to both ray coverage and the velocity gradients required by the data. This scheme is computationally expensive, so we use a distributed computing framework based on the Java Parallel Processing Framework, providing us with {approx}400 processors. Resolution of our model is assessed using a variation of the standard checkerboard method, as well as by directly estimating the diagonal of the model resolution matrix based on the technique developed by Bekas, et al. We compare the travel-time prediction and location capabilities of this model over standard 1D models. We perform location tests on a global, geographically-distributed event set with ground truth levels of 5 km or better. These events generally possess hundreds of Pn and P phases from which we can generate different realizations of station distributions, yielding a range of azimuthal coverage and proportions of teleseismic to regional arrivals, with which we test the robustness and quality of relocation. The SALSA3D model reduces mislocation over standard 1D ak135, especially with increasing azimuthal gap. The 3D model appears to perform better for locations based solely or dominantly on regional arrivals, which is not unexpected given that ak135 represents a global average and cannot therefore capture local and regional variations.

Ballard, Sanford; Encarnacao, Andre Villanova; Begnaud, Michael A. (Los Alamos National Laboratories); Rowe, Charlotte A. (Los Alamos National Laboratories); Lewis, Jennifer E.; Young, Christopher John; Chang, Marcus C.; Hipp, James Richard

2010-04-01T23:59:59.000Z

265

The dispersive Alfven wave in the time-stationary limit with a focus on collisional and warm-plasma effects  

SciTech Connect

A nonlinear, collisional, two-fluid model of uniform plasma convection across a field-aligned current (FAC) sheet, describing the stationary Alfven (StA) wave, is presented. In a previous work, Knudsen showed that, for cold, collisionless plasma [D. J. Knudsen, J. Geophys. Res. 101, 10761 (1996)], the stationary inertial Alfven (StIA) wave can accelerate electrons parallel to a background magnetic field and cause large, time-independent plasma-density variations having spatial periodicity in the direction of the convective flow over a broad range of spatial scales and energies. Knudsen suggested that these fundamental properties of the StIA wave may play a role in the formation of discrete auroral arcs. Here, Knudsen's model has been generalized for warm, collisional plasma. From this generalization, it is shown that nonzero ion-neutral and electron-ion collisional resistivity significantly alters the perpendicular ac and dc structure of magnetic-field-aligned electron drift, and can either dissipate or enhance the field-aligned electron energy depending on the initial value of field-aligned electron drift velocity. It is also shown that nonzero values of plasma pressure increase the dominant Fourier component of perpendicular wavenumber.

Finnegan, S. M.; Koepke, M. E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States); Knudsen, D. J. [Department of Physics and Astronomy, University of Calgary, Calgary, Alberta (Canada)

2008-05-15T23:59:59.000Z

266

Tidal waves as yrast states in transitional nuclei  

E-Print Network (OSTI)

The yrast states of transitional nuclei are described as quadrupole waves running over the nuclear surface, which we call tidal waves. In contrast to a rotor, which generates angular momentum by increasing the angular velocity at approximately constant deformation, a tidal wave generates angular momentum by increasing the deformation at approximately constant angular velocity. The properties of the tidal waves are calculated by means of the cranking model in a microscopic way. The calculated energies and E2 transition probabilities of the yrast states in the transitional nuclides with $Z$= 44, 46, 48 and $N=56, 58, ..., 66$ reproduce the experiment in detail. The nonlinear response of the nucleonic orbitals results in a strong coupling between shape and single particle degrees of freedom.

S. Frauendorf; Y. Gu; J. Sun

2010-02-16T23:59:59.000Z

267

Relativistic solitary waves with phase modulation embedded in long laser pulses in plasmas  

SciTech Connect

We investigate the existence of nonlinear phase-modulated relativistic solitary waves embedded in an infinitely long circularly polarized electromagnetic wave propagating through a plasma. These states are exact nonlinear solutions of the 1-dimensional Maxwell-fluid model for a cold plasma composed of electrons and ions. The solitary wave, which consists of an electromagnetic wave trapped in a self-generated Langmuir wave, presents a phase modulation when the group velocity V and the phase velocity V{sub ph} of the long circularly polarized electromagnetic wave do not match the condition VV{sub ph} = c{sup 2}. The main properties of the waves as a function of their group velocities, wavevectors, and frequencies are studied, as well as bifurcations of the dynamical system that describes the waves when the parameter controlling the phase modulation changes from zero to a finite value. Such a transition is illustrated in the limit of small amplitude waves where an analytical solution for a grey solitary wave exists. The solutions are interpreted as the stationary state after the collision of a long laser pulse with an isolated solitary wave.

Sanchez-Arriaga, G.; Siminos, E.; Lefebvre, E. [CEA, DAM, DIF, 91297 Arpajon (France)

2011-08-15T23:59:59.000Z

268

Determination of Non-thermal Velocity Distributions from SERTS Linewidth Observations  

Science Journals Connector (OSTI)

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

Aaron J. Coyner; Joseph M. Davila

2011-01-01T23:59:59.000Z

269

DETERMINATION OF NON-THERMAL VELOCITY DISTRIBUTIONS FROM SERTS LINEWIDTH OBSERVATIONS  

SciTech Connect

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

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

2011-12-01T23:59:59.000Z

270

Discrete Hamiltonian variational integrators  

Science Journals Connector (OSTI)

......Journal of Numerical Analysis (2011) 31, 1497-1532 doi:10.1093/imanum/drq027 Advance Access publication on March 17, 2011 Discrete Hamiltonian variational integrators MELVIN LEOK Department of Mathematics, University of California, San......

Melvin Leok; Jingjing Zhang

2011-10-01T23:59:59.000Z

271

Calculus of Variations  

E-Print Network (OSTI)

Calc. Var. 15, 451–491 (2002). Calculus of Variations. Donatella Danielli ..... u ? W1,p loc (Rn) such that for every ? ? W1,p o. (Rn) with compact support. (2.14).

Katharina Steingraeber Heidelberg 1107 1997 Oct 17 14:59:21

2002-11-18T23:59:59.000Z

272

Faster-Than-Light Group Velocities and Causality Violation  

Science Journals Connector (OSTI)

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

1970-01-01T23:59:59.000Z

273

Doppler-shifted fluorescence imaging of velocity fields in supersonic reacting flows  

SciTech Connect

The application of Doppler-shifted fluorescence imaging of velocity fields in supersonic reacting flows is analyzed. Focussing on fluorescence of the OH molecule in typical H2-air Scramjet flows, the effects of uncharacterized variations in temperature, pressure, and collisional partner composition across the measurement plane are examined. Detailed measurements of the (1,0) band OH lineshape variations in H2-air combustions are used, along with single-pulse and time-averaged measurements of an excimer-pumped dye laser, to predict the performance of a model velocimeter with typical Scramjet flow properties. The analysis demonstrates the need for modification and control of the laser bandshape in order to permit accurate velocity measurements in the presence of multivariant flow properties. 13 refs.

Allen, M.G.; Davis, S.J.; Kessler, W.J.; Sonnenfroh, D.M. (Physical Sciences, Inc., Andover, MA (United States))

1992-07-01T23:59:59.000Z

274

The variation of efficiency with angle of expansion, exit area, and velocity in a square diffuser  

E-Print Network (OSTI)

tapered seotices. Ths ezit tapered section is called the diffuser. The purpose of the diffaser 1s to decelerate the fluid snd raise its statio precede. The difference in pressure betseen the inlet and the azit of the venturi uhieh is a measure... increases ar as ths aLse of the vsnturi tube is in- creased, If the speed of flow through a venturi is gradually increased to an abnormally high value~ the ov~ pressure drop will increase very rapidly after a definite speed has been attained. If...

Weber, Hugh Conrad

2012-06-07T23:59:59.000Z

275

The seasonal variation of the zonal velocity of the Atlantic Equatorial Undercurrent  

E-Print Network (OSTI)

Io (O~ LC lr ) Gr 8 0 4 0 0 Gl no en Co 08 n 8 mo 8 're Gl 'J No al 0 0 0 0 8 m 08 m m nCC om N r me- m ~ 0 Gl CCC ~ Or N mN Co ~ o ejcl 0 8 CD I 8 OID r o or- Co I? o~z Cl 4 CO er ccr 8! Oo I 0 I CD Co C...O. )0 0 IA (0 0 8 0) IO 0 Ip 0 QN 0 0 0) (P ?, elpO N)0 IA 8 8 Od' (0 00 0 8 (") p 0 ~c) 0 00 8 0 0 R 0 Qoeo Q ID eln~- N I 0 ~Q I 0 A 8 Rie 0 Q I (00 8 CA LC) C5 I? o~ (C) Z 4 0 0 4 0 0 0 @ I4 0 A 0 t5 A 4 0 0 0...

Olling, Charles Randolph

2012-06-07T23:59:59.000Z

276

Velocity Variation Assessment of Red Blood Cell Aggregation with Spectral Domain Doppler Optical Coherence Tomography  

E-Print Network (OSTI)

J. G. Fujimoto. Optical coherence tomog- raphy. Science 254:spectral domain low coherence interferometry and retinalsedimentation on optical coherence tomography signals from

Xu, Xiangqun; Yu, Lingfeng; Chen, Zhongping

2010-01-01T23:59:59.000Z

277

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

278

Sound velocity bound and neutron stars  

E-Print Network (OSTI)

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

Paulo F. Bedaque; Andrew W. Steiner

2015-01-25T23:59:59.000Z

279

VELOCITY-SHEAR-INDUCED MODE COUPLING IN THE SOLAR ATMOSPHERE AND SOLAR WIND: IMPLICATIONS FOR PLASMA HEATING AND MHD TURBULENCE  

SciTech Connect

We analytically consider how velocity shear in the corona and solar wind can cause an initial Alfven wave to drive up other propagating signals. The process is similar to the familiar coupling into other modes induced by non-WKB refraction in an inhomogeneous plasma, except here the refraction is a consequence of velocity shear. We limit our discussion to a low-beta plasma, and ignore couplings into signals resembling the slow mode. If the initial Alfven wave is propagating nearly parallel to the background magnetic field, then the induced signals are mainly a forward-going (i.e., propagating in the same sense as the original Alfven wave) fast mode, and a driven signal propagating like a forward-going Alfven wave but polarized like the fast mode; both signals are compressive and subject to damping by the Landau resonance. For an initial Alfven wave propagating obliquely with respect to the magnetic field, the induced signals are mainly forward- and backward-going fast modes, and a driven signal propagating like a forward-going Alfven wave but polarized like the fast mode; these signals are all compressive and subject to damping by the Landau resonance. A backward-going Alfven wave, thought to be important in the development of MHD turbulence, is also produced, but it is very weak. However, we suggest that for oblique propagation of the initial Alfven wave the induced fast-polarized signal propagating like a forward-going Alfven wave may interact coherently with the initial Alfven wave and distort it at a strong-turbulence-like rate.

Hollweg, Joseph V.; Chandran, Benjamin D. G. [Space Science Center, Morse Hall, University of New Hampshire, Durham, NH 03824 (United States); Kaghashvili, Edisher Kh., E-mail: joe.hollweg@unh.edu, E-mail: ekaghash@aer.com, E-mail: benjamin.chandran@unh.edu [Atmospheric and Environmental Research, A Verisk Analytics Company, 131 Hartwell Avenue, Lexington, MA 02421 (United States)

2013-06-01T23:59:59.000Z

280

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

E-Print Network (OSTI)

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

Whitley, Darrell

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

Non-diffracting chirped Bessel waves in optical antiguides  

E-Print Network (OSTI)

Chirped Bessel waves are introduced as stable (non-diffracting) solutions of the paraxial wave equation in optical antiguides with a power-law radial variation in their index of refraction. Through numerical simulations, we investigate the propagation of apodized (finite-energy) versions of such waves, with or without vorticity, in antiguides with practical parameters. The new waves exhibit a remarkable resistance against the defocusing effect of the unstable index potentials, outperforming standard Gaussians with the same full width at half maximum. The chirped profile persists even under conditions of eccentric launching or antiguide bending and is also capable of self-healing like standard diffraction-free beams in free space.

Chremmos, Ioannis

2015-01-01T23:59:59.000Z

282

Ecoclimate: Variations, Interactions, and Teleconnections  

E-Print Network (OSTI)

the covariance of vertical wind speed and concentration tothat the mean vertical velocity wind speed is zero on time

Swann, Abigail Lynn Segal

2010-01-01T23:59:59.000Z

283

Electromagnetic waves destabilized by runaway electrons in near-critical electric fields  

SciTech Connect

Runaway electron distributions are strongly anisotropic in velocity space. This anisotropy is a source of free energy that may destabilize electromagnetic waves through a resonant interaction between the waves and the energetic electrons. In this work, we investigate the high-frequency electromagnetic waves that are destabilized by runaway electron beams when the electric field is close to the critical field for runaway acceleration. Using a runaway electron distribution appropriate for the near-critical case, we calculate the linear instability growth rate of these waves and conclude that the obliquely propagating whistler waves are most unstable. We show that the frequencies, wave numbers, and propagation angles of the most unstable waves depend strongly on the magnetic field. Taking into account collisional and convective damping of the waves, we determine the number density of runaways that is required to destabilize the waves and show its parametric dependences.

Komar, A.; Pokol, G. I. [Department of Nuclear Techniques, Budapest University of Technology and Economics, Association EURATOM, H-1111 Budapest (Hungary); Fueloep, T. [Department of Applied Physics, Nuclear Engineering, Chalmers University of Technology and Euratom-VR Association, Goeteborg (Sweden)

2013-01-15T23:59:59.000Z

284

Ion Heating with Beating Electrostatic Waves  

SciTech Connect

The nonlinear interaction of a magnetized ion with two beating electrostatic waves (BEW) whose frequencies differ by a cyclotron harmonic can lead, under some conditions [Phys. Rev. E 69, 046402 (2004)], to vigorous acceleration for an ion with arbitrarily low initial velocity. When applied to an ensemble of ions, this mechanism promises enhanced heating over single electrostatic wave (SEW) heating for comparable wave energy densities. The extension of single ion acceleration to heating (SEWH and BEWH) of an ensemble of initially thermalized ions was carried out to compare the processes. Using a numerical solution of the Vlasov equation as a guideline, an analytical expression for the heating level was derived with Lie transforms and was used to show BEWH's superiority over all parameter space.

Jorns, B.; Choueiri, E. Y. [Electric Propulsion and Plasma Dynamics Laboratory (EPPDyL), Princeton University, Princeton, New Jersey 08544 (United States)

2011-02-25T23:59:59.000Z

285

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

SciTech Connect

To test the hypothesis that high quality 3D Earth models will produce seismic event locations which are more accurate and more precise, we are developing a global 3D P wave velocity model of the Earth's crust and mantle using seismic tomography. In this paper, we present the most recent version of our model, SALSA3D 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.

Encarnacao, Andre Villanova; Begnaud, Michael A. (Los Alamos National Laboratories); Rowe, Charlotte A. (Los Alamos National Laboratories); Young, Christopher John; Chang, Marcus C.; Ballard, Sally C.; Hipp, James Richard

2010-06-01T23:59:59.000Z

286

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

287

Velocity Shear Stabilization of Centrifugally Confined Plasma  

Science Journals Connector (OSTI)

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

Yi-Min Huang and A. B. Hassam

2001-11-16T23:59:59.000Z

288

LATTICE BOLTZMANN SCHEMES WITH RELATIVE VELOCITIES  

E-Print Network (OSTI)

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

Boyer, Edmond

289

Bulk flow velocities in the solar corona  

Science Journals Connector (OSTI)

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

D. J. Lewis; G. M. Simnett

2000-10-01T23:59:59.000Z

290

Experimental determination of radiated internal wave power without pressure field Frank M. Lee,1  

E-Print Network (OSTI)

in global ocean mixing, it is important to understand the power present in the internal wave fieldExperimental determination of radiated internal wave power without pressure field data Frank M. Lee to determine, using only velocity field data, the time-averaged energy flux J and total radiated power P

Morrison, Philip J.,

291

Waves and the equilibrium range at Ocean Weather Station P J. Thomson,1  

E-Print Network (OSTI)

energy spectra. Observations are consistent with a local balance between wind input and breaking is extended to a wider range of conditions using observations of wave energy spectra and wind speed during a 2 friction velocity u� (and thus wind stress) directly controls wave energy spectra levels at high fre

292

Cyclotron waves in a non-neutral plasma column Daniel H. E. Dubin  

E-Print Network (OSTI)

plasma column with near-Maxwellian velocity distributions. We focus on the z-independent component#12;Cyclotron waves in a non-neutral plasma column Daniel H. E. Dubin Department of Physics April 2013; published online 25 April 2013) A kinetic theory of linear electrostatic plasma waves

California at San Diego, University of

293

Shock-Wave Attenuation and Energy-Dissipation Potential of Granular Materials  

E-Print Network (OSTI)

Shock-Wave Attenuation and Energy-Dissipation Potential of Granular Materials Mica Grujicic, B this approach, both compression shocks and decompression waves are treated as (stress, specific volume, particle velocity, mass-based internal energy density, temperature, and mass-based entropy density) propagating

Grujicic, Mica

294

Electron Climbing a 'Devil's Staircase' in Wave-Particle Interaction  

SciTech Connect

Numerous nonlinear driven systems display spectacular responses to forcing, including chaos and complex phase-locking plateaus characterized by 'devil's staircase', Arnold tongues, and Farey trees. In the universality class of Hamiltonian systems, a paradigm is the motion of a charged particle in two waves, which inspired a renormalization group method for its description. Here we report the observation of the underlying 'devil's staircase' by recording the beam velocity distribution function at the outlet of a traveling wave tube versus the amplitude of two externally induced waves.

Macor, Alessandro; Doveil, Fabrice; Elskens, Yves [Physique des interactions ioniques et moleculaires, Unite 6633 CNRS-Universite de Provence, Equipe turbulence plasma, case 321, Centre de Saint-Jerome, F-13397 Marseille cedex 20 (France)

2005-12-31T23:59:59.000Z

295

Josephson oscillations of charge density waves  

SciTech Connect

The formation of charge density waves in solids was originally proposed as a possible mechanism for superconductivity by Froehlich. Although the experimentally discovered materials with charge density waves (CDW)s are found to have finite resistivity as a result of impurity pinning, they nevertheless reveal many interesting features including motion which is analogous to a resistively shunted Josephson junction of superconductors. The noise spectrum of CDW systems is reviewed with particular emphasis on interactions with normal as well as magnetic impurities. Future prospects for observing an amplitude variation of the noise signals induced by a magnetic field are proposed.

Ruvalds, J.; Tua, P.F.

1985-01-01T23:59:59.000Z

296

An active wave generating–absorbing boundary condition for VOF type numerical model  

Science Journals Connector (OSTI)

The objective of the present work is to discuss the implementation of an active wave generating–absorbing boundary condition for a numerical model based on the Volume Of Fluid (VOF) method for tracking free surfaces. First an overview of the development of VOF type models with special emphasis in the field of coastal engineering is given. A new type of numerical boundary condition for combined wave generation and absorption in the numerical model \\{VOFbreak2\\} is presented. The numerical boundary condition is based on an active wave absorption system that was first developed in the context of physical wave flume experiments, using a wave paddle. The method applies to regular and irregular waves. Velocities are measured at one location inside the computational domain. The reflected wave train is separated from the incident wave field in front of a structure by means of digital filtering and subsequent superposition of the measured velocity signals. The incident wave signal is corrected, so that the reflected wave is effectively absorbed at the boundary. The digital filters are derived theoretically and their practical design is discussed. The practical use of this numerical boundary condition is compared to the use of the absorption system in a physical wave flume. The effectiveness of the active wave generating–absorbing boundary condition finally is proved using analytical tests and numerical simulations with VOFbreak2.

Peter Troch; Julien De Rouck

1999-01-01T23:59:59.000Z

297

Lorentz violation and red shift of gravitational waves in brane-worlds  

E-Print Network (OSTI)

In this paper we study the speed of gravitational waves in a brane world scenario and show that if the extra dimension is space-like, the speed of the propagation of such waves is greater in the bulk than that on the brane. Therefore, the 4D Lorentz invariance is broken in the gravitational sector. A comparison is also made between the red shift of such waves and those of the electromagnetic waves on the brane. Such a comparison is essential for extracting the signature of the extra dimension and thus clarifying the question of maximal velocity of gravitational waves in the bulk.

Fatemeh Ahmadi; Jafar Khodagholizadeh; H. R. Sepangi

2014-11-07T23:59:59.000Z

298

Lecture 11, Corona Waves, Oscillations and Mass Motions  

E-Print Network (OSTI)

. Coronal Waves: Seismological Tools Wei Liu @Stanford-Lockheed 15 Three types of magnetohydrodynamic (MHD fronts) to correct for the sphericity of the Sun; 2. Space-time diagram; 3. Base difference-Lockheed 20 #12;11 Steep stripes at ~2000 km/s Velocity fits on space-time diagrams Wei Liu @Stanford

299

Reflection and transmission of surface waves in laterally varying media  

Science Journals Connector (OSTI)

......regional phases Pg and Lg at the Nevada Test Site, J. geophys. Res., 1981...velocity heterogeneity under the Nevada Test Site on short-period P wave amplitudes...Key 1967). In studies of the Nevada Test Site, Barker, Der & Mrazek (1981......

M. G. Bostock

1992-05-01T23:59:59.000Z

300

Mesoscale Waves as a Probe of Jupiter's Deep Atmosphere  

Science Journals Connector (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

Note: This page contains sample records for the topic "wave velocity variations" from the National Library of EnergyBeta (NLEBeta).
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to obtain the most current and comprehensive results.


301

Radial velocities of population II binary stars. II  

E-Print Network (OSTI)

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

A. Bartkevicius; J. Sperauskas

2006-01-10T23:59:59.000Z

302

Variational calculation of the trapping rate in thermal barriers  

SciTech Connect

A variational calculation of the trapping rate and trapped ion density in thermal barriers is presented. The effects of diffusion in energy as well as pitch angle scattering are retained. The variational formulation uses the actual trapped-passing boundary in velocity space. The boundary condition is that the trapped ion distribution function matches the passing ion distribution function, which is taken to be a Maxwellian, on the boundary. The results compare well with two-dimensional Fokker-Planck code calculations by Futch and LoDestro.

Li, X.Z.; Emmert, G.A.

1982-10-01T23:59:59.000Z

303

Variational transition state theory  

SciTech Connect

This research program involves the development of variational transition state theory (VTST) and semiclassical tunneling methods for the calculation of gas-phase reaction rates and selected applications. The applications are selected for their fundamental interest and/or their relevance to combustion.

Truhlar, D.G. [Univ. of Minnesota, Minneapolis (United States)

1993-12-01T23:59:59.000Z

304

Ion-acoustic cnoidal waves in a quantum plasma  

SciTech Connect

Nonlinear ion-acoustic cnoidal wave structures are studied in an unmagnetized quantum plasma. Using the reductive perturbation method, a Korteweg-de Vries equation is derived for appropriate boundary conditions and nonlinear periodic wave solutions are obtained. The corresponding analytical solution and numerical plots of the ion-acoustic cnoidal waves and solitons in the phase plane are presented using the Sagdeev pseudo-potential approach. The variations in the nonlinear potential of the ion-acoustic cnoidal waves are studied at different values of quantum parameter H{sub e} which is the ratio of electron plasmon energy to electron Fermi energy defined for degenerate electrons. It is found that both compressive and rarefactive ion-acoustic cnoidal wave structures are formed depending on the value of the quantum parameter. The dependence of the wavelength and frequency on nonlinear wave amplitude is also presented.

Mahmood, S. [Physics Institute, Federal University of Rio Grande do Sul, RS, Porto Alegre 915051-970 (Brazil); Theoretical Physics Division (TPD), PINSTECH P.O. Nilore, Islamabad 44000 (Pakistan); Haas, F. [Physics Institute, Federal University of Rio Grande do Sul, RS, Porto Alegre 915051-970 (Brazil)

2014-10-15T23:59:59.000Z

305

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

E-Print Network (OSTI)

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

Barron, John

306

Enhancing the efficiency of slow-wave electron cyclotron masers with the tapered refractive index  

SciTech Connect

The nonlinear analysis of slow-wave electron cyclotron masers (ECM) based on anomalous Doppler effect in a slab waveguide is presented. A method of tapered refractive index (TRI) is proposed to enhance the efficiency of slow-wave ECM. The numerical calculations show that the TRI method can significantly enhance the efficiency of slow-wave ECM with the frequency ranging from the microwave to terahertz band. The effect of beam velocity spread on the efficiency has also been studied. Although the velocity spread suppresses the efficiency significantly, a great enhancement of efficiency can still be introduced by the TRI method.

Kong Lingbao; Hou Zhiling; Jing Jian [School of Science and Beijing Key Laboratory of Environmentally Harmful Chemicals Assessment, Beijing University of Chemical Technology, Beijing 100029 (China); Jin Haibo [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Du Chaohai [Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China)

2013-04-15T23:59:59.000Z

307

Accessibility for lower hybrid waves in PBX-M  

SciTech Connect

Understanding the wave damping mechanism in the presence of a `spectral gap` is an important issue for the current profile control using Lower Hybrid Current Drive (LHCD). The authors examine a traditional explanation based upon upshifting of the wave parallel refractive index (n{sub {parallel}}) and find that there can be an upper bound in the n{sub {parallel}} upshift. The amount of upshift is not sufficient to bridge the spectral gap completely under some PBX-M LHCD conditions. There is experimental evidence, however, that current was driven even under such conditions. Another mechanism is also considered, based upon the 2-D velocity space dynamics coupled with a compound wave spectrum, here consisting of forward- and backward-running waves. The runaway critical speed relative to the phase speeds of these waves plays an important role in this model.

Takahashi, H.; Bell, R.; Bernabei, S.; Chance, M.; Chu, T.K.; Gettelfinger, G.; Greenough, N.; Hatcher, R.; Ignat, D.; Jardin, S.; Kaita, R.; Kaye, S.; Kugel, H.; LeBlanc, B.; Manickam, J.; Okabayashi, M.; Ono, M.; Paul, S.; Perkins, F.; Sauthoff, N.; Sesnic, S.; Sun, Y.; Tighe, W.; Valeo, E.; von Goeler, S. [Princeton Univ., NJ (US). Plasma Physics Lab.; Batha, S.; Levinton, F. [Fusion Physics and Technology, Torrance, CA (US); Dunlap, J.; England, A.; Harris, J.; Hirshman, S.; Isler, R.; Post-Zwicker, A. [Oak Ridge National Lab., TN (US); Jones, S.; Kesner, J.; Luckhardt, S.; Paoletti, F. [Massachusetts Inst. of Tech., Cambridge, MA (US); Schmitz, L.; Tynan, G. [Univ. of California, Los Angeles, CA (US)

1993-07-01T23:59:59.000Z

308

Wave power absorption: Experiments in open sea and simulation  

Science Journals Connector (OSTI)

A full scale prototype of a wave power plant based on a direct drive linear generator driven by a point absorber has been installed at the west coast of Sweden. In this paper experimentally collected data of energy absorption for different electrical loads are used to verify a model of the wave power plant including the interactions of wave buoy generator and external load circuit. The wave-buoy interaction is modeled with linear potential wavetheory. The generator is modeled as a nonlinear mechanical damping function that is dependent on piston velocity and electric load. The results show good agreement between experiments and simulations. Potential wavetheory is well suited for the modeling of a point absorber in normal operation and for the design of future converters. Moreover the simulations are fast which opens up for simulations of wave farms.

M. Eriksson; R. Waters; O. Svensson; J. Isberg; M. Leijon

2007-01-01T23:59:59.000Z

309

Surface electromagnetic wave equations in a warm magnetized quantum plasma  

SciTech Connect

Based on the single-fluid plasma model, a theoretical investigation of surface electromagnetic waves in a warm quantum magnetized inhomogeneous plasma is presented. The surface electromagnetic waves are assumed to propagate on the plane between a vacuum and a warm quantum magnetized plasma. The quantum magnetohydrodynamic model includes quantum diffraction effect (Bohm potential), and quantum statistical pressure is used to derive the new dispersion relation of surface electromagnetic waves. And the general dispersion relation is analyzed in some special cases of interest. It is shown that surface plasma oscillations can be propagated due to quantum effects, and the propagation velocity is enhanced. Furthermore, the external magnetic field has a significant effect on surface wave's dispersion equation. Our work should be of a useful tool for investigating the physical characteristic of surface waves and physical properties of the bounded quantum plasmas.

Li, Chunhua; Yang, Weihong [Department of Modern Physics, University of Science and Technology of China, 230026 Hefei (China); Wu, Zhengwei, E-mail: wuzw@ustc.edu.cn [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); Center of Low Temperature Plasma Application, Yunnan Aerospace Industry Company, Kunming, 650229 Yunnan (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong)

2014-07-15T23:59:59.000Z

310

Interaction of two walkers: Wave-mediated energy and force  

E-Print Network (OSTI)

A bouncing droplet, self-propelled by its interaction with the waves it generates, forms a classical wave-particle association called a "walker." Previous works have demonstrated that the dynamics of a single walker is driven by its global surface wave field that retains information on its past trajectory. Here, we investigate the energy stored in this wave field for two coupled walkers and how it conveys an interaction between them. For this purpose, we characterize experimentally the "promenade modes" where two walkers are bound, and propagate together. Their possible binding distances take discrete values, and the velocity of the pair depends on their mutual binding. The mean parallel motion can be either rectilinear or oscillating. The experimental results are recovered analytically with a simple theoretical framework. A relation between the kinetic energy of the droplets and the total energy of the standing waves is established.

Borghesi, Christian; Labousse, Matthieu; Eddi, Antonin; Fort, Emmanuel; Couder, Yves

2014-01-01T23:59:59.000Z

311

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

E-Print Network (OSTI)

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

A. Bartkevicius; J. Sperauskas

2007-01-30T23:59:59.000Z

312

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

E-Print Network (OSTI)

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

A. Bartkevicius; J. Sperauskas

2006-01-10T23:59:59.000Z

313

Observation of negative-frequency waves in a water tank: A classical analogue to the Hawking effect?  

E-Print Network (OSTI)

The conversion of positive-frequency waves into negative-frequency waves at the event horizon is the mechanism at the heart of the Hawking radiation of black holes. In black-hole analogues, horizons are formed for waves propagating in a medium against the current when and where the flow exceeds the wave velocity. We report on the first direct observation of negative-frequency waves converted from positive-frequency waves in a moving medium. The measured degree of mode conversion is significantly higher than expected from theory.

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

2008-03-01T23:59:59.000Z

314

Analytical modeling of elastic-plastic wave behavior near grain boundaries in crystalline materials  

SciTech Connect

It is well known that changes in material properties across an interface will produce differences in the behavior of reflected and transmitted waves. This is seen frequently in planar impact experiments, and to a lesser extent, oblique impacts. In anisotropic elastic materials, wave behavior as a function of direction is usually accomplished with the aid of velocity surfaces, a graphical method for predicting wave scattering configurations. They have expanded this method to account for inelastic deformation due to crystal plasticity. The set of derived equations could not be put into a characteristic form, but instead led to an implicit problem. to overcome this difficulty an algorithm was developed to search the parameters space defined by a wave normal vector, particle velocity vector, and a wave speed. A solution was said to exist when a set from this parameter space satisfied the governing vector equation. Using this technique they can predict the anisotropic elastic-plastic velocity surfaces and grain boundary scattering configuration for crystalline materials undergoing deformation by slip. Specifically, they have calculated the configuration of scattered elastic-plastic waves in anisotropic NiAl for an incident compressional wave propagating along a <111> direction and contacting a 45 degree inclined grain boundary and found that large amplitude transmitted waves exist owing to the fact that the wave surface geometry forces it to propagate near the zero Schmid factor direction <100>.

Loomis, Eric [Los Alamos National Laboratory; Greenfield, Scott [Los Alamos National Laboratory; Luo, Shengnian [Los Alamos National Laboratory; Swift, Damian [LLNL; Peralta, Pedro [ASU

2009-01-01T23:59:59.000Z

315

AN EXTREME-ULTRAVIOLET WAVE ASSOCIATED WITH A SURGE  

SciTech Connect

Taking advantage of the high temporal and spatial resolution observations from the Solar Dynamics Observatory, we present an extreme-ultraviolet (EUV) wave associated with a surge on 2010 November 13. Due to the magnetic flux cancelation, some surges formed in the source active region (AR). The strongest surge produced our studied event. The surge was deflected by the nearby loops that connected to another AR, and disrupted the overlying loops that slowly expanded and eventually evolved into a weak coronal mass ejection (CME). The surge was likely associated with the core of the CME. The EUV wave happened after the surge deflected. The wave departed far from the flare center and showed a close location relative to the deflected surge. The wave propagated in a narrow angular extent, mainly in the ejection direction of the surge. The close timing and location relations between the EUV wave and the surge indicate that the wave was closely associated with the CME. The wave had a velocity of 310-350 km s{sup -1}, while the speeds of the surge and the expanding loops were about 130 and 150 km s{sup -1}, respectively. All of the results suggest that the EUV wave was a fast-mode wave and was most likely triggered by the weak CME.

Zheng, Ruisheng; Jiang, Yunchun; Yang, Jiayan; Bi, Yi; Hong, Junchao; Yang, Bo; Yang, Dan, E-mail: zhrsh@ynao.ac.cn [National Astronomical Observatories/Yunnan Astronomical Observatory, Chinese Academy of Sciences, Kunming 650011 (China)] [National Astronomical Observatories/Yunnan Astronomical Observatory, Chinese Academy of Sciences, Kunming 650011 (China)

2013-02-10T23:59:59.000Z

316

Propagating and reflecting of spin wave in permalloy nanostrip with 360° domain wall  

SciTech Connect

By micromagnetic simulation, we investigated the interaction between propagating spin wave (or magnonic) and a 360° domain wall in a nanostrip. It is found that propagating spin wave can drive a 360° domain wall motion, and the velocity and direction are closely related to the transmission coefficient of the spin wave of the domain wall. When the spin wave passes through the domain wall completely, the 360° domain wall moves toward the spin wave source. When the spin wave is reflected by the domain wall, the 360° domain wall moves along the spin wave propagation direction. Moreover, when the frequency of the spin wave is coincident with that of the 360° domain wall normal mode, the 360° domain wall velocity will be resonantly enhanced no matter which direction the 360 DW moves along. On the other hand, when the spin wave is reflected from the moving 360° domain wall, we observed the Doppler effect clearly. After passing through a 360° domain wall, the phase of the spin wave is changed, and the phase shift is related to the frequency. Nevertheless, phase shift could be manipulated by the number of 360° domain walls that spin wave passing through.

Zhang, Senfu; Mu, Congpu; Zhu, Qiyuan; Zheng, Qi; Liu, Xianyin; Wang, Jianbo; Liu, Qingfang, E-mail: liuqf@lzu.edu.cn [Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000 (China)

2014-01-07T23:59:59.000Z

317

Kelvin Waves around Antarctica  

Science Journals Connector (OSTI)

The Southern Ocean allows circumpolar structure and the Antarctic coastline plays a role as a waveguide for oceanic Kelvin waves. Under the cyclic conditions, the horizontal wavenumbers and frequencies for circumpolarly propagating waves are ...

Kazuya Kusahara; Kay I. Ohshima

2014-11-01T23:59:59.000Z

318

Surface wave tomography of the western United States from ambient seismic noise: Rayleigh wave group velocity maps  

E-Print Network (OSTI)

, Department of Physics, University of Colorado at Boulder, Campus Box 390, Boulder, Colorado 80309, USA River flood basalts, the Snake River Plain and Yellowstone, and mantle wedge features associated

Ritzwolle, Mike

319

Observation of propagating edge spin waves modes  

SciTech Connect

Broadband magnetization response of equilateral triangular 1000 nm Permalloy dots has been studied under an in-plane magnetic field, applied parallel (buckle state), and perpendicular (Y state) to the triangles base. Micromagnetic simulations identify edge spin waves (E-SWs) in the buckle state as SWs propagating along the two adjacent edges. These quasi one-dimensional spin waves emitted by the vertex magnetic charges gradually transform from propagating to standing due to interference and are weakly affected by dipolar interdot interaction and variation of the aspect ratio. Spin waves in the Y state have a two dimensional character. These findings open perspectives for implementation of the E-SWs in magnonic crystals and thin films.

Lara, A.; Aliev, F. G., E-mail: farkhad.aliev@uam.es [Dpto. Física de la Materia Condensada C-III, Instituto Nicolas Cabrera (INC) and Condensed Matter Physics Institute (IFIMAC), Universidad Autónoma de Madrid, Madrid 28049 (Spain); Metlushko, V. [Department of Electrical and Computer Engineering, University of Illinois, Chicago, Illinois 60607 (United States)

2013-12-07T23:59:59.000Z

320

Wave fronts, pulses and wave trains in photoexcited superlattices behaving as excitable or oscillatory media  

E-Print Network (OSTI)

Undoped and strongly photoexcited semiconductor superlattices with field-dependent recombination behave as excitable or oscillatory media with spatially discrete nonlinear convection and diffusion. Infinitely long, dc-current-biased superlattices behaving as excitable media exhibit wave fronts with increasing or decreasing profiles, whose velocities can be calculated by means of asymptotic methods. These superlattices can also support pulses of the electric field. Pulses moving downstream with the flux of electrons can be constructed from their component wave fronts, whereas pulses advancing upstream do so slowly and experience saltatory motion: they change slowly in long intervals of time separated by fast transitions during which the pulses jump to the previous superlattice period. Photoexcited superlattices can also behave as oscillatory media and exhibit wave trains.

J. I. Arana; L. L. Bonilla; H. T. Grahn

2011-09-30T23:59:59.000Z

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.


321

Gravity perturbed Crapper waves  

Science Journals Connector (OSTI)

...waves are known to have multi-valued height. Using...gravity-capillary waves with multi-valued height. The...of single-valued and multi-valued travelling waves...absence of gravity, a family of exact solutions is...elliptic functions. Building upon the work by Tanveer...

2014-01-01T23:59:59.000Z

322

Observations on waveforms of capillary and gravity-capillary waves  

Science Journals Connector (OSTI)

Due to extreme conditions in the field, there has not been any observational report on three-dimensional waveforms of short ocean surface waves. Three-dimensional waveforms of short wind waves can be found from integrating surface gradient image data (Zhang 1996a). Ocean surface gradient images are captured by an optical surface gradient detector mounted on a raft operating in the water offshore California (Cox and Zhang 1997). Waveforms and spatial structures of short wind waves are compared with early laboratory wind wave data (Zhang 1994, 1995). Although the large-scale wind and wave conditions are quite different, the waveforms are resoundingly similar at the small scale. It is very common, among steep short wind waves, that waves in the capillary range feature sharp troughs and flat crests. The observations show that most short waves are far less steep than the limiting waveform under weak wind conditions. Waveforms that resemble capillary-gravity solitons are observed with a close match to the form theoretically predicted for potential flows (Longuet-Higgins 1989, Vanden-Broeck and Dias 1992). Capillaries are mainly found as parasitic capillaries on the forward face of short gravity waves. The maximum wavelength in a parasitic wave train is less than a centimeter. The profiles of parasitic wave trains and longitudinal variations are shown. The phenomenon of capillary blockage (Phillips 1981) on dispersive freely traveling short waves is observed in the tank but not at sea. The short waves seen at sea propagate in all directions while waves in the tank are much more unidirectional.

Xin Zhang

1999-01-01T23:59:59.000Z

323

Performance Assessment of the Wave Dragon Wave Energy Converter  

E-Print Network (OSTI)

Performance Assessment of the Wave Dragon Wave Energy Converter Based on the EquiMar Methodology S of the wave energy sector, device developers are called to provide reliable estimates on power performanceMar, Nissum Bredning, Hanstholm, North Sea, Ekofisk, Wave-to-wire, Wave energy. I. INTRODUCTION The wave

Hansen, René Rydhof

324

The Effect of Wave Breaking on the Wave Energy Spectrum  

Science Journals Connector (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

325

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

326

WAVE MIXING SPECTROSCOPY  

E-Print Network (OSTI)

is that due to the Doppler effect in gaseous media.velocity due to the Doppler shift effect. In solid state

Smith, Robert William

2010-01-01T23:59:59.000Z

327

Wave Activity Events and the Variability of the Stratospheric Polar Vortex  

Science Journals Connector (OSTI)

During Northern Hemisphere winter, polar stratospheric winds and temperatures exhibit significant variability that is due to the vertical propagation of planetary-scale waves. The most dramatic intraseasonal variations in temperature are ...

Abraham Solomon

2014-10-01T23:59:59.000Z

328

A Representation of SU(2) and Isospin Waves in a Solid Nuclear Matter  

Science Journals Connector (OSTI)

......2) and Isospin Waves in a Solid Nuclear Matter Koichi Takahashi Department...variational evaluation of the ground state energy under pion condensation on a dense...Deformation of Lattice in a Solid Nuclear Matter Koichi Takahashi References......

Koichi Takahashi

1991-09-01T23:59:59.000Z

329

Daytime Variations in Phytoplankton Photosynthesis  

Science Journals Connector (OSTI)

Daytime Variations in Phytoplankton Photosynthesis. JACOB VERDUIN. Bowling Green State University,. Bowling Green, Ohio. ABSTRACT. A study of ...

1999-12-14T23:59:59.000Z

330

Resonant Interactions Between Protons and Oblique Alfven/Ion-Cyclotron Waves  

SciTech Connect

Resonant interactions between ions and Alfven/ion-cyclotron (A/IC) waves may play an important role in the heating and acceleration of the fast solar wind. Although such interactions have been studied extensively for 'parallel' waves, whose wave vectors k are aligned with the background magnetic field B{sub 0}, much less is known about interactions between ions and oblique A/IC waves, for which the angle theta between k and B{sub 0} is nonzero. In this paper, we present new numerical results on resonant cyclotron interactions between protons and oblique A/IC waves in collisionless low-beta plasmas such as the solar corona. We find that if some mechanism generates oblique high-frequency A/IC waves, then these waves initially modify the proton distribution function in such a way that it becomes unstable to parallel waves. Parallel waves are then amplified to the point that they dominate the wave energy at the large parallel wave numbers at which the waves resonate with the particles. Pitch-angle scattering by these waves then causes the plasma to evolve towards a state in which the proton distribution is constant along a particular set of nested 'scattering surfaces' in velocity space, whose shapes have been calculated previously. As the distribution function approaches this state, the imaginary part of the frequency of parallel A/IC waves drops continuously towards zero, but oblique waves continue to undergo cyclotron damping while simultaneously causing protons to diffuse across these kinetic shells to higher energies. We conclude that oblique A/IC waves can be more effective at heating protons than parallel A/IC waves, because for oblique waves the plasma does not relax towards a state in which proton damping of oblique A/IC waves ceases.

Pongkitiwanichakul, Peera; Chandran, Benjamin D. G.; Isenberg, Philip A.; Vasquez, Bernard J. [Institute for the Study of Earth, Oceans and Space, University of New Hampshire, Durham NH, 03824 (United States)

2010-03-25T23:59:59.000Z

331

The Effects of Magnetizer Velocity on Magnetic Flux Leakage Signals  

Science Journals Connector (OSTI)

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

J. Bruce Nestleroth; Richard J. Davis

1993-01-01T23:59:59.000Z

332

Velocity of the electric arc in a plasmatron discharge chamber  

Science Journals Connector (OSTI)

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

A. S. Shaboltas

1969-09-01T23:59:59.000Z

333

THE VELOCITY CENTROID PERIODICITY OF L2 PUPPIS' SiO MASER EMISSION  

SciTech Connect

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

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

2013-09-01T23:59:59.000Z

334

A variational calculation of the trapping rate in thermal barriers  

Science Journals Connector (OSTI)

A variational calculation of the trapping rate and trapped-ion density in thermal barriers is presented. The effects of diffusion in energy as well as pitch-angle scattering are retained. The variational formulation uses the actual trapped/passing boundary in velocity space. The boundary condition is that the trapped-ion distribution function match the passing-ion distribution function, which is taken to be a Maxwellian, on the boundary. The results compare well with the two-dimensional Fokker-Planck code calculations by Futch and LoDestro. The CPU time for a variational calculation is less than 0.1 s using the CRAY-I computer, while a typical Fokker-Planck code calculation takes 10–20 min.

X.Z. Li; G.A. Emmert

1984-01-01T23:59:59.000Z

335

A Variable-resolution Surface Wave Dispersion Study of Eurasia, North Africa, and Surrounding Regions  

SciTech Connect

This paper presents the results of a large-scale study of surface wave dispersion performed across Eurasia and North Africa. Improvements were made to previous surface wave work by enlarging the study region, increasing path density, improving spatial resolution, and expanding the period range. This study expands the coverage area northwards and eastwards relative to a previous dispersion analysis, which covered only North Africa and the Middle East. We have significantly increased the number of seismograms examined and group velocity measurements made. We have now made good quality dispersion measurements for about 30,000 Rayleigh wave and 20,000 Love wave paths, and have incorporated measurements from several other researchers into the study. A conjugate gradient method was employed for the group velocity tomography, which improved the inversion from the previous study by adopting a variable smoothness. This technique allows us to go to higher resolution where the data allow without producing artifacts. The current results include both Love and Rayleigh wave inversions across the region for periods from 7 to 100 seconds at 1{sup o} resolution. Short period group velocities are sensitive to slow velocities associated with large sedimentary features such as the Caspian Sea, West Siberian Platform, Mediterranean Sea, Bay of Bengal, Tarim Basin, and Persian Gulf. Intermediate periods are sensitive to differences in crustal thickness, such as those between oceanic and continental crust or along orogenic zones and continental plateaus. At longer periods, fast velocities are consistently found beneath cratons while slow upper mantle velocities occur along rift systems, subduction zones, and collision zones such as the Tethys Belt. We have compared the group velocities at various periods with features such as sediment thickness, topographic height, crustal thickness, proximity to plate boundaries, lithospheric age and lithospheric thickness, and find significant correlations. We don't find any similar correlation between the longest period surface waves and hot spots.

Pasyanos, M E

2005-03-21T23:59:59.000Z

336

On Approximating the Translational Velocity of Vortex Rings  

E-Print Network (OSTI)

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

Mohseni, Kamran

337

LAMINAR BURNING VELOCITY OF GASOLINES WITH ADDITION OF ETHANOL  

E-Print Network (OSTI)

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

Boyer, Edmond

338

Compressional and Shear-Wave Velocity versus Depth Relations for Common Rock Types in Northern California  

Science Journals Connector (OSTI)

...1 1.638 4 0.31 4 5.28 Merritt sand (Qm) 0.024 0.986 1 0.43 1 2.30 Merritt sand (Qm) 0.030 1.610 1 0.31 1 5.21 Merritt sand (Qm) 0.037 1.610...Pilot Hole Vp and Vs logs. Nick Christensen provided unpublished...

Thomas M. Brocher

339

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

Open Energy Info (EERE)

structures of the Coso geothermal area, California, from microseismic travel time data Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article:...

340

P- and SV-wave transversely isotropic phase velocities analysis from VSP data  

Science Journals Connector (OSTI)

......et al. have been used for the inversion process. Therefore, inverted parameters can be...Expanded obstructs, .5&h Ann. Int. SEG Mtg, Houston, pp. 464-468. Keith, C...Expanded ubstracts, 59th Ann. Int. SEG Mtg, Dallas, pp. Lines, L. R. & Treitel......

J. de Parscau

1991-12-01T23:59:59.000Z

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

3-D shear wave radially and azimuthally anisotropic velocity model of the North American upper mantle  

Science Journals Connector (OSTI)

......partially during the subsequent tectonism of flat Farallon subduction (Humphreys et al...Thick-structured Proterozoic lithosphere of the Rocky Mountain region, GSA Today, 11, 4-9...azimuthal anisotropy beneath the Colorado Rocky Mountains, in The Rocky Mountain Region-An......

Huaiyu Yuan; Barbara Romanowicz; Karen M. Fischer; David Abt

2011-03-01T23:59:59.000Z

342

Shear wave velocity, seismic attenuation, and thermal structure of the continental upper mantle  

Science Journals Connector (OSTI)

......where E* is the activation energy, R is the gas constant, tau...This is achieved by use of a cost function based on the norm...Petrologic and non-steady-state geothermal constraints available for these...1965. Attenuation of seismic energy in upper mantle, J. geophys......

Irina M. Artemieva; Magali Billien; Jean-Jacques Lévêque; Walter D. Mooney

2004-05-01T23:59:59.000Z

343

Prediction of rocks thermal conductivity from elastic wave velocities, mineralogy and microstructure  

Science Journals Connector (OSTI)

......exploitation of geothermal energy rely on the proper...predict TC in a cost-effective way...geometry of the cost-function and...crustal rocks and geothermal applications...Clauser C. Geothermal energy. Landolt Bornstein......

Lucas Pimienta; Joel Sarout; Lionel Esteban; Claudio Delle Piane

2014-01-01T23:59:59.000Z

344

Surface wave phase velocities of the Western United States from a two-station method  

Science Journals Connector (OSTI)

......Columbia Plateau flood basalts, HLP and...Rio Grande Rift), Colorado Plateau, WF (Wasatch...Rocky Mountains in Colorado, possibly reflecting...the Columbia River flood basalts to the east...the Columbia River flood basalts and the northeastern...colocated with the Colorado Plateau, possibly......

Anna Foster; Göran Ekström; Meredith Nettles

2014-01-01T23:59:59.000Z

345

E-Print Network 3.0 - aortic pulse-wave velocity Sample Search...  

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

Fluid Dynamics ECCOMAS CDF 2006 Summary: . Priaux (Eds) TU Delft, Delft The Netherland, 2006 THE INFLUENCE OF ASYMMETRIC INFLOW IN ABDOMINAL AORTIC... the hemodynamics in...

346

A new method to determine phase velocities of Rayleigh waves from microseisms  

Science Journals Connector (OSTI)

...special situations where there are significant contributions from subway lines, pipelines, geothermal processes, and the like. Note...overlapped Fast Fourier Transform processing: IEEE Transactions on Audio Electroacoustics, AU-21 , 337-344. Henstridge, J. D...

Ikuo Cho; Taku Tada; Yuzo Shinozaki

347

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.

348

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

Science Journals Connector (OSTI)

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

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

2014-01-01T23:59:59.000Z

349

THE EFFECT OF THE PRE-DETONATION STELLAR INTERNAL VELOCITY PROFILE ON THE NUCLEOSYNTHETIC YIELDS IN TYPE Ia SUPERNOVA  

SciTech Connect

A common model of the explosion mechanism of Type Ia supernovae is based on a delayed detonation of a white dwarf. A variety of models differ primarily in the method by which the deflagration leads to a detonation. A common feature of the models, however, is that all of them involve the propagation of the detonation through a white dwarf that is either expanding or contracting, where the stellar internal velocity profile depends on both time and space. In this work, we investigate the effects of the pre-detonation stellar internal velocity profile and the post-detonation velocity of expansion on the production of {alpha}-particle nuclei, including {sup 56}Ni, which are the primary nuclei produced by the detonation wave. We perform one-dimensional hydrodynamic simulations of the explosion phase of the white dwarf for center and off-center detonations with five different stellar velocity profiles at the onset of the detonation. In order to follow the complex flows and to calculate the nucleosynthetic yields, approximately 10,000 tracer particles were added to every simulation. We observe two distinct post-detonation expansion phases: rarefaction and bulk expansion. Almost all the burning to {sup 56}Ni occurs only in the rarefaction phase, and its expansion timescale is influenced by pre-existing flow structure in the star, in particular by the pre-detonation stellar velocity profile. We find that the mass fractions of the {alpha}-particle nuclei, including {sup 56}Ni, are tight functions of the empirical physical parameter {rho}{sub up}/v{sub down}, where {rho}{sub up} is the mass density immediately upstream of the detonation wave front and v{sub down} is the velocity of the flow immediately downstream of the detonation wave front. We also find that v{sub down} depends on the pre-detonation flow velocity. We conclude that the properties of the pre-existing flow, in particular the internal stellar velocity profile, influence the final isotopic composition of burned matter produced by the detonation.

Kim, Yeunjin; Jordan, G. C. IV; Graziani, Carlo; Lamb, D. Q.; Truran, J. W. [Astronomy Department, University of Chicago, Chicago, IL 60637 (United States); Meyer, B. S. [Physics and Astronomy Department, Clemson University, Clemson, SC 29634 (United States)

2013-07-01T23:59:59.000Z

350

A global 3D P-Velocity model of the Earth%3CU%2B2019%3Es crust and mantle for improved event location.  

SciTech Connect

To test the hypothesis that high quality 3D Earth models will produce seismic event locations which are more accurate and more precise, we are developing a global 3D P wave velocity model of the Earth's crust and mantle using seismic tomography. In this paper, we present the most recent version of our model, SALSA3D (SAndia LoS Alamos) version 1.4, and demonstrate its ability to reduce mislocations for a large set of realizations derived from a carefully chosen set of globally-distributed ground truth events. Our model is derived from the latest version of the Ground Truth (GT) catalog of P and Pn travel time picks assembled by Los Alamos National Laboratory. To prevent over-weighting due to ray path redundancy and to reduce the computational burden, we cluster rays to produce representative rays. Reduction in the total number of ray paths is > 55%. The model is represented using the triangular tessellation system described by Ballard et al. (2009), which incorporates variable resolution in both the geographic and radial dimensions. For our starting model, we use a simplified two layer crustal model derived from the Crust 2.0 model over a uniform AK135 mantle. Sufficient damping is used to reduce velocity adjustments so that ray path changes between iterations are small. We obtain proper model smoothness by using progressive grid refinement, refining the grid only around areas with significant velocity changes from the starting model. At each grid refinement level except the last one we limit the number of iterations to prevent convergence thereby preserving aspects of broad features resolved at coarser resolutions. Our approach produces a smooth, multi-resolution model with node density appropriate to both ray coverage and the velocity gradients required by the data. This scheme is computationally expensive, so we use a distributed computing framework based on the Java Parallel Processing Framework, providing us with {approx}400 processors. Resolution of our model is assessed using a variation of the standard checkerboard method, as well as by directly estimating the diagonal of the model resolution matrix based on the technique developed by Bekas, et al. We compare the travel-time prediction and location capabilities of this model over standard 1D models. We perform location tests on a global, geographically-distributed event set with ground truth levels of 5 km or better. These events generally possess hundreds of Pn and P phases from which we can generate different realizations of station distributions, yielding a range of azimuthal coverage and proportions of teleseismic to regional arrivals, with which we test the robustness and quality of relocation. The SALSA3D model reduces mislocation over standard 1D ak135, especially with increasing azimuthal gap. The 3D model appears to perform better for locations based solely or dominantly on regional arrivals, which is not unexpected given that ak135 represents a global average and cannot therefore capture local and regional variations.

Ballard, Sanford; Encarnacao, Andre Villanova; Begnaud, Michael A. (Los Alamos National Laboratories); Rowe, Charlotte A. (Los Alamos National Laboratories); Lewis, Jennifer E.; Young, Christopher John; Chang, Marcus C.; Hipp, James Richard

2010-05-01T23:59:59.000Z

351

Generation of electromagnetic structures via modulational instability of drift waves  

SciTech Connect

Generation mechanism for large scale electromagnetic structures (blobs) is considered by employing the technique of four-wave interactions (modulational instability). It is shown that primary electrostatic turbulence may generate elongated electromagnetic structures with poloidal modulations. Such structures are principally related to drift-Alfven waves. The analysis fully takes into account finite ion temperature effects and associated diamagnetic contributions to Reynolds stress. The turbulent generation of blobs has instability growth rates which scale similar to the zonal flow instabilities, {gamma}{approx}, where q is a characteristic wave vector of large scale modes, and V-tilde is a characteristic amplitude of the velocity of turbulent fluctuations. This analysis is shown to be fully consistent with results of an earlier analysis by using the wave kinetic equation.

Smolyakov, A. I. [Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 (Canada); Nuclear Fusion Institute, Russian Research Center 'Kurchatov Institute', 1 Kurchatov Square, 123182, Moscow (Russian Federation); Krasheninnikov, S. I. [University of California at San Diego, 9500 Gilman Dr., La Jolla, California 92093 (United States)

2008-07-15T23:59:59.000Z

352

Whistler Modes with Wave Magnetic Fields Exceeding the Ambient Field  

Science Journals Connector (OSTI)

Whistler-mode wave packets with fields exceeding the ambient dc magnetic field have been excited in a large, high electron-beta plasma. The waves are induced with a loop antenna with dipole moment either along or opposite to the dc field. In the latter case the excited wave packets have the topology of a spheromak but are propagating in the whistler mode along and opposite to the dc magnetic field. Field-reversed configurations with net zero helicity have also been produced. The electron magnetohydrodynamics fields are force free, have wave energy density exceeding the particle energy density, and propagate stably at subelectron thermal velocities through a nearly uniform stationary ion density background.

R. L. Stenzel; J. M. Urrutia; K. D. Strohmaier

2006-03-10T23:59:59.000Z

353

On plane waves in diluted relativistic cold plasmas  

E-Print Network (OSTI)

We briefly report on some exact results [G. Fiore, arXiv:1312.4665 preprint, to appear in J. Phys. A] regarding plane waves in a relativistic cold plasma. If the plasma, initially at rest, is reached by a transverse plane electromagnetic travelling-wave, then its motion has a very simple dependence on this wave in the limit of zero density, otherwise can be determined by an iterative procedure whose accuracy decreases with time or the plasma density. Thus one can describe in particular the impact of a very intense and short laser pulse onto a plasma and determine conditions for the "slingshot effect" [G. Fiore, R. Fedele, U. De Angelis, arXiv:1309.1400 preprint] to occur. The motion in vacuum of a charged test particle subject to a wave of the same kind is also determined, for any initial velocity.

Gaetano Fiore

2014-05-01T23:59:59.000Z

354

About measurements of stopping power behind intense shock waves  

Science Journals Connector (OSTI)

Method of generation of plasma targets with electron densities n e ?10 21 ? cm ?3 behind strong shock wave for study of energy losses of protons and heavy ions is discussed. The problems of matching of large scale accelerator facility and explosive technique are considered. It is suggested to use small (<150 g TNT) vacuum pumped explosive metallic chambers with fast valves in such experiments. Construction of small-sized explosively driven generators of strong shock waves is described. Estimations of stopping power in strong shock waves in hydrogen xenon and argon were carried out. It is shown that to get main contribution of free electrons it is necessary to have velocities of shock wave in xenon and argon more than 20 km/s and in hydrogen more than 60 km/s.

V. Gryaznov; M. Kulish; V. Mintsev; V. Fortov; B. Sharkov; A. Golubev; A. Fertman; N. Mescheryakov; D. H. H. Hoffmann; M. Stetter; C. Stöckl; D. Gardes

1998-01-01T23:59:59.000Z

355

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

Science Journals Connector (OSTI)

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

K. Dolag; R. Sunyaev

2013-01-01T23:59:59.000Z

356

On the fully nonlinear acoustic waves in a plasma with positrons beam impact and superthermal electrons  

SciTech Connect

Arbitrary amplitude ion-acoustic waves in an unmagnetized plasma consisting of cold positive ions, superthermal electrons, and positrons beam are reported. The basic set of fluid equations is reduced to an energy-balance like equation. The latter is numerically analyzed to examine the existence regions for solitary and shock waves. It is found that only solitary waves can propagate, however, the model cannot support shocks. The effects of superthermality and beam parameters (via, positrons concentration and streaming velocity) on the existence region, as well as solitary wave profile have been discussed.

Ali Shan, S. [Theoretical Plasma Physics Division, PINSTECH, Nilore, 44000 Islamabad (Pakistan) [Theoretical Plasma Physics Division, PINSTECH, Nilore, 44000 Islamabad (Pakistan); National Centre For Physics (NCP), Shahdra Valley Road, 44000 Islamabad (Pakistan); Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad (Pakistan); El-Tantawy, S. A.; Moslem, W. M. [Department of Physics, Faculty of Science, Port Said University, Port Said 42521 (Egypt)] [Department of Physics, Faculty of Science, Port Said University, Port Said 42521 (Egypt)

2013-08-15T23:59:59.000Z

357

Experimental Study of Nonlinear Dust Acoustic Solitary Waves in a Dusty Plasma  

Science Journals Connector (OSTI)

The excitation and propagation of finite-amplitude low-frequency solitary waves are investigated in an argon plasma impregnated with kaolin dust particles. A nonlinear longitudinal dust acoustic solitary wave is excited by pulse modulating the discharge voltage with a negative potential. It is found that the velocity of the solitary wave increases and the width decreases with the increase of the modulating voltage, but the product of the solitary wave amplitude and the square of the width remains nearly constant. The experimental findings are compared with analytic soliton solutions of a model Korteveg–de Vries equation.

P. Bandyopadhyay; G. Prasad; A. Sen; P. K. Kaw

2008-08-08T23:59:59.000Z

358

Coupling SPH with a 1-D Boussinesq-type wave Christophe Kassiotis, Martin Ferrand, Damien Violeau, Benedict D. Rogers,  

E-Print Network (OSTI)

Coupling SPH with a 1-D Boussinesq-type wave model Christophe Kassiotis, Martin Ferrand, Damien-D Finite Difference Boussinesq-type model. The latter deals with wave propagations for most. These velocity and water height values are then driven by the Boussinesq-type model. As an illustration

Paris-Sud XI, Université de

359

Filament velocity scaling laws for warm ions  

SciTech Connect

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

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

2013-10-15T23:59:59.000Z

360

Hypersonic wave propagation in the triton X-100 2014 water gelation system as studied by Brillouin spectroscopy  

E-Print Network (OSTI)

1211 Hypersonic wave propagation in the triton X-100 2014 water gelation system as studied, quelle que soit la concentration de triton X-100. Abstract 2014 The hypersonic velocity and absorption refractometer. Analysis of the results show that in the gel phase hypersonic waves propagate effectively through

Paris-Sud XI, Université de

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.


361

A modified variational approach to scattering  

E-Print Network (OSTI)

to the formulation names. By using the variational condition put forth in Eq. (3. 12), we obtain -i ~ = j(l. )~)-Z' p gz J E E. -kz (~~10~)+Z(A+8) (3. 42) r ~ (+I~I61 &4;ILt )(4;lLI ) As stated earlier, this g is related to P through Eq. (3. 9). Com- k bining... that where Wg mr P (rj= ZrZ e (2. 9) in the units Eq. (2. 2). The Schrddinger wave equation for the system, H% = EW, then becomes ? '7- ? ?, +, -, ]I ? E'i t 22 s Ig, Iq &g! where E is the total energy of the system. This may be written [fl+H+ tj~p~](1...

Parnell, Gregory Elliott

2012-06-07T23:59:59.000Z

362

Single-mode fiber, velocity interferometry  

SciTech Connect

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

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

2011-04-15T23:59:59.000Z

363

GEOPHYSICS, VOL. 66, NO. 3 (MAY-JUNE 2001); P. 904910, 7 FIGS., 3 TABLES. Velocity analysis for tilted transversely isotropic media: A physical  

E-Print Network (OSTI)

in conventional imaging, it is important to be able to recon- struct the velocity model suitable for anisotropic depth migration. Here, we discuss the results of anisotropic pa- rameter estimation on a physical and the anisotropic parameters and . The coefficient is obtained using the travel- times of a wave that crosses

Tsvankin, Ilya

364

Finite-frequency sensitivity kernels for global seismic wave propagation based upon adjoint methods  

Science Journals Connector (OSTI)

......wave. P-wave energy enters the shadow...generally has a lower frequency content compared...simulate the seismic response of 2D and 3D geological...2006. Finite-frequency Kernels based upon...2004. Finite-frequency tomography reveals...Circumventing storage limitations in variational......

Qinya Liu; Jeroen Tromp

2008-07-01T23:59:59.000Z

365

Hohlraum Designs for High Velocity Implosions on NIF  

SciTech Connect

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

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

2011-10-19T23:59:59.000Z

366

Wave momentum flux parameter: a descriptor for nearshore waves  

E-Print Network (OSTI)

Wave momentum flux parameter: a descriptor for nearshore waves Steven A. Hughes* US Army Engineer Available online 7 October 2004 Abstract A new parameter representing the maximum depth-integrated wave momentum flux occurring over a wave length is proposed for characterizing the wave contribution

US Army Corps of Engineers

367

Shallow Water Waves and Solitary Waves Willy Hereman  

E-Print Network (OSTI)

Shallow Water Waves and Solitary Waves Willy Hereman Department of Mathematical and Computer of the Subject II. Introduction­Historical Perspective III. Completely Integrable Shallow Water Wave Equations IV. Shallow Water Wave Equations of Geophysical Fluid Dynamics V. Computation of Solitary Wave Solutions VI

Hereman, Willy A.M.

368

Matter Waves and Electricity  

Science Journals Connector (OSTI)

Classical four-dimensional relativity gives a most natural and harmonious interpretation of the three basic phenomena of nature: gravity, electricity, and the wave structure of matter, provided that the basic assumptions of the Einsteinian theory are modified in two respects: (1) the fundamental invariant of the action principle is chosen as a quadratic instead of a linear function of the curvature components; (2) the static equilibrium of the world is replaced by a dynamic equilibrium. Electricity comes out as a second-order resonance effect of the matter waves. The matter waves are gravitational waves but superposed not on an empty Euclidean space but on a space of high average curvature.

Cornelius Lanczos

1942-06-01T23:59:59.000Z

369

kinetic wave energy  

Science Journals Connector (OSTI)

kinetic wave energy ? kinetische Wellenenergie f [Teil der Wellenlänge, die im Feld der Orbitalgeschwindigkeiten unter der Welle enthalten ist und als Orbitalbewegung am Ort verbleibt

2014-08-01T23:59:59.000Z

370

potential wave energy  

Science Journals Connector (OSTI)

potential wave energy ? potentielle Wellenenergie f [Der für die Auslenkung des Wasserspiegels zum Ruhewasserspiegel erforderliche Teil der Wellenenergie, die mit der Wellengeschwindigkeit fortbewegt...

2014-08-01T23:59:59.000Z

371

Seismic wave attenuation in carbonates L. Adam,1,2  

E-Print Network (OSTI)

and permeability between 0.03 and 58.1 mdarcy. Contrary to most observations in sandstones, bulk compressibility waves is common practice in reservoir rock physics. Variations in reservoir seismic properties can more than half of the current major oil and gas reservoirs in the world are in carbonates, these rocks

Boise State University

372

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

373

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

SciTech Connect

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

374

Evaluation of layer thickness in human teeth using higher-order-mode leaky Lamb wave interdigital transducers  

SciTech Connect

An ultrasonic nondestructive evaluation technique of the layer thickness in human teeth is proposed using a leaky Lamb wave device with two arch-shaped interdigital transducers, operating at a plate/water interface. The use of a higher-order-mode leaky Lamb wave with a phase velocity higher than the longitudinal wave velocity in the human tooth is essential to detect reflected ultrasound beams from the tooth section The layer thickness of dentin, estimated from the measured time interval between two reflected echoes, is in good agreement with the optically measured data.

Toda, Shinji; Fujita, Takeshi; Arakawa, Hirohisa; Toda, Kohji [Department of Dental and Public Health, Kanagawa Dental College, 82 Inaoka, Yokosuka 238-8580 (Japan); Department of Electrical and Electronic Engineering, National Defense Academy, 1-10-20 Hashirimizu, Yokosuka 239-8686 (Japan); Department of Dental and Public Health, Kanagawa Dental College, 82 Inaoka, Yokosuka 238-8580 (Japan); Department of Electrical and Electronic Engineering, National Defense Academy, 1-10-20 Hashirimizu, Yokosuka 239-8686 (Japan)

2005-03-01T23:59:59.000Z

375

Theory of steady-state plane tunneling-assisted impact ionization waves  

SciTech Connect

The effect of band-to-band and trap-assisted tunneling on the properties of steady-state plane ionization waves in p{sup +}-n-n{sup +} structures is theoretically analyzed. It is shown that such tunneling-assisted impact ionization waves do not differ in a qualitative sense from ordinary impact ionization waves propagating due to the avalanche multiplication of uniformly distributed seed electrons and holes. The quantitative differences of tunneling-assisted impact ionization waves from impact ionization waves are reduced to a slightly different relation between the wave velocity u and the maximum field strength E{sub M} at the front. It is shown that disregarding impact ionization does not exclude the possibility of the existence of tunneling-assisted ionization waves; however, their structure radically changes, and their velocity strongly decreases for the same E{sub M}. A comparison of the dependences u(E{sub M}) for various ionization-wave types makes it possible to determine the conditions under which one of them is dominant. In conclusion, unresolved problems concerning the theory of tunneling-assisted impact ionization waves are discussed and the directions of further studies are outlined.

Kyuregyan, A. S., E-mail: ask@vei.ru [Lenin All-Russian Electrical-Engineering Institute (Russian Federation)

2013-07-15T23:59:59.000Z

376

ION HEATING BY A SPECTRUM OF OBLIQUELY PROPAGATING LOW-FREQUENCY ALFVEN WAVES  

SciTech Connect

Ion stochastic heating by a monochromatic Alfven wave, which propagates obliquely to the background magnetic field, has been studied by Chen et al. It is shown that ions can be resonantly heated at frequencies a fraction of the ion cyclotron frequency when the wave amplitude is sufficiently large. In this paper, the monochromatic wave is extended to a spectrum of left-hand polarized Alfven waves. When the amplitude of the waves is small, the components of the ion velocity have several distinct frequencies, and their motions are quasi-periodic. However, when the amplitude of the waves is sufficiently large, the components of the ion velocity have a spectrum of continuous frequencies near the ion cyclotron frequency due to the nonlinear coupling between the Alfven waves and the ion gyromotion, and the ion motions are stochastic. Compared with the case of a monochromatic Alfven wave, the threshold of the ion stochastic heating by a spectrum of Alfven waves is much lower. Even when their frequencies are only several percent of the ion cyclotron frequency, the ions can also be stochastically heated. The relevance of this heating mechanism to solar corona is also discussed.

Lu Quanming [CAS Laboratory of Basic Plasma Physics, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026 (China); Chen Liu [Institute for Fusion and Simulation, Zhejiang University, Hangzhou 310027 (China)

2009-10-10T23:59:59.000Z

377

Surface-wave and refraction tomography at the FACT Site, Sandia National Laboratories, Albuquerque, New Mexico.  

SciTech Connect

We present a technique that allows for the simultaneous acquisition and interpretation of both shear-wave and compressive-wave 3-D velocities. The technique requires no special seismic sources or array geometries, and is suited to studies with small source-receiver offsets. The method also effectively deals with unwanted seismic arrivals by using the statistical properties of the data itself to discriminate against spurious picks. We demonstrate the technique with a field experiment at the Facility for Analysis, Calibration, and Testing at Sandia National Laboratories, Albuquerque, New Mexico. The resulting 3-D shear-velocity and compressive-velocity distributions are consistent with surface geologic mapping. The averaged velocities and V{sub p}/V{sub s} ratio in the upper 30 meters are also consistent with examples found in the scientific literature.

Abbott, Robert E.; Bartel, Lewis Clark; Pullammanappallil, Satish (Optim, Inc., Reno, NV); Engler, Bruce Phillip

2006-08-01T23:59:59.000Z

378

Wave runup on cylinders subject to deep water random waves  

E-Print Network (OSTI)

was measured close to the test cylinders are analyzed. These data on wave runup in deepwater random waves were generated at similar water depths with significant wave heights and spectral peak periods. Statistical parameters, zero crossing analysis...

Indrebo, Ann Kristin

2012-06-07T23:59:59.000Z

379

Wave Energy Resource Analysis for Use in Wave Energy Conversion  

E-Print Network (OSTI)

In order to predict the response of wave energy converters an accurate representation of the wave climate resource is crucial. This paper gives an overview of wave resource modeling techniques as well as detailing a methodology for estimating...

Pastor, J.; Liu, Y.; Dou, Y.

2014-01-01T23:59:59.000Z

380

Free-Wave Energy Dissipation in Experimental Breaking Waves  

Science Journals Connector (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

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

Harmonic generation of gravitational wave induced Alfven waves  

E-Print Network (OSTI)

Here we consider the nonlinear evolution of Alfven waves that have been excited by gravitational waves from merging binary pulsars. We derive a wave equation for strongly nonlinear and dispersive Alfven waves. Due to the weak dispersion of the Alfven waves, significant wave steepening can occur, which in turn implies strong harmonic generation. We find that the harmonic generation is saturated due to dispersive effects, and use this to estimate the resulting spectrum. Finally we discuss the possibility of observing the above process.

Mats Forsberg; Gert Brodin

2007-11-26T23:59:59.000Z

382

Self-consistent full wave simulations of lower hybrid waves  

E-Print Network (OSTI)

Self-consistent full wave simulations of lower hybrid waves John C. Wright P. T. Bonoli - MIT E .J for Simulation of Wave-Plasma Interactions L.A. Berry, D.B. Batchelor, E.F. Jaeger, E. D`Azevedo D. Green C. Milanesio #12;3 Outline · Introduction to Lower Hybrid waves · Modeling LH waves ­ Ray tracing ­ Full Wave

Wright, John C.

383

Radial velocity measurements of white dwarfs  

E-Print Network (OSTI)

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

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

2000-07-11T23:59:59.000Z

384

True Masses of Radial-Velocity Exoplanets  

E-Print Network (OSTI)

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

Brown, Robert A

2015-01-01T23:59:59.000Z

385

Shake Table for Calibration of Velocity Pickups  

Science Journals Connector (OSTI)

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

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

1957-01-01T23:59:59.000Z

386

Integrated campaign to study the stationary inertial Alfvn wave in the laboratory and space This article has been downloaded from IOPscience. Please scroll down to see the full text article.  

E-Print Network (OSTI)

are in colour only in the electronic version) 1. Introduction The stationary inertial Alfv´en (StIA) wave [1 of StIA waves is magnetic-field-aligned (s-direction in figure 1) electron drift energy that overcomes of the effective phase velocity vector, as shown, and is approximately zero. The StIA wave vector is approximately

California at Berkeley, University of

387

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

E-Print Network (OSTI)

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

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

2010-01-01T23:59:59.000Z

388

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

389

Wave energy: a Pacific perspective  

Science Journals Connector (OSTI)

...study by Cornett used wind/wave hindcasting to assess Canada's offshore wave energy resource...will probably attract offshore birds, possibly leading...related projects, such as offshore wind farms. If wave energy development...

2012-01-01T23:59:59.000Z

390

Rainbow trapping of guided waves  

E-Print Network (OSTI)

Rainbow trapping of guided waves Javier Polanco and Rosa M.the propagation of a wave packet that is a superpositionof three s-polarized guided waves with different frequencies

Polanco, Javier; Fitzgerald, Rosa M; Leskova, Tamara A; Maradudin, Alexei A

2011-01-01T23:59:59.000Z

391

Center for Wave Phenomena Wave Phenomena  

E-Print Network (OSTI)

into a life of scientific discovery." Kurang Mehta, Ph.D. Class of 2007 Shell Exploration and Production Phil research and education program in seismic exploration, monitoring and wave propagation. The main focus and efficiency of seismic processing algorithms, especially for application to regions of structural complexity

392

Wireless power transmission using ultrasonic guided waves  

Science Journals Connector (OSTI)

The unavailability of suitable power supply at desired locations is currently an important obstacle in the development of distributed, wireless sensor networks for applications such as structural health monitoring of aircraft. Proposed solutions range from improved batteries to energy harvesting from vibration, temperature gradients and other sources. A novel approach is being investigated at Cardiff University School of Engineering in cooperation with Airbus. It aims to utilise ultrasonic guided Lamb waves to transmit energy through the aircraft skin. A vibration generator is to be placed in a location where electricity supply is readily available. Ultrasonic waves generated by this device will travel through the aircraft structure to a receiver in a remote wireless sensor node. The receiver will convert the mechanical vibration of the ultrasonic waves back to electricity, which will be used to power the sensor node. This paper describes the measurement and modelling of the interference pattern which emerges when Lamb waves are transmitted continuously as in this power transmission application. The discovered features of the pattern, such as a large signal amplitude variation and a relatively high frequency, are presented and their importance for the development of a power transmission system is discussed.

A Kural; R Pullin; C Featherston; C Paget; K Holford

2011-01-01T23:59:59.000Z

393

Waveinduced velocities inside a model seagrass bed Mitul Luhar,1  

E-Print Network (OSTI)

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

Nepf, Heidi M.

394

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

E-Print Network (OSTI)

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

2009-05-29T23:59:59.000Z

395

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

Science Journals Connector (OSTI)

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

2003-05-02T23:59:59.000Z

396

Propagation of sound waves through a spatially homogeneous but smoothly time-dependent medium  

SciTech Connect

The propagation of sound through a spatially homogeneous but non-stationary medium is investigated within the framework of fluid dynamics. For a non-vortical fluid, especially, a generalized wave equation is derived for the (scalar) potential of the fluid velocity distribution in dependence of the equilibrium mass density of the fluid and the sound wave velocity. A solution of this equation for a finite transition period ? is determined in terms of the hypergeometric function for a phenomenologically realistic, sigmoidal change of the mass density and sound wave velocity. Using this solution, it is shown that the energy flux of the sound wave is not conserved but increases always for the propagation through a non-stationary medium, independent of whether the equilibrium mass density is increased or decreased. It is found, moreover, that this amplification of the transmitted wave arises from an energy exchange with the medium and that its flux is equal to the (total) flux of the incident and the reflected wave. An interpretation of the reflected wave as a propagation of sound backward in time is given in close analogy to Feynman and Stueckelberg for the propagation of anti-particles. The reflection and transmission coefficients of sound propagating through a non-stationary medium is analyzed in more detail for hypersonic waves with transition periods ? between 15 and 200 ps as well as the transformation of infrasound waves in non-stationary oceans. -- Highlights: •Analytically exact study of sound propagation through a non-stationary medium. •Energy exchange between the non-stationary medium and the sound wave. •Transformation of hypersonic and ultrasound frequencies in non-stationary media. •Propagation of sound backward in time in close analogy to anti-particles. •Prediction of tsunamis both in spatially and temporally inhomogeneous oceans.

Hayrapetyan, A.G., E-mail: armen@physi.uni-heidelberg.de [Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, D-69120 Heidelberg (Germany); Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Grigoryan, K.K.; Petrosyan, R.G. [Yerevan State University, 1 Alex Manoogian Str., 0025 Yerevan (Armenia)] [Yerevan State University, 1 Alex Manoogian Str., 0025 Yerevan (Armenia); Fritzsche, S. [Helmholtz-Institut Jena, Fröbelstieg 3, D-07743 Jena (Germany) [Helmholtz-Institut Jena, Fröbelstieg 3, D-07743 Jena (Germany); Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, D-07743 Jena (Germany)

2013-06-15T23:59:59.000Z

397

Wave Energy | Open Energy Information  

Open Energy Info (EERE)

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

398

ALFVÉN WAVES IN SIMULATIONS OF SOLAR PHOTOSPHERIC VORTICES  

SciTech Connect

Using advanced numerical magneto-hydrodynamic simulations of the magnetized solar photosphere, including non-gray radiative transport and a non-ideal equation of state, we analyze plasma motions in photospheric magnetic vortices. We demonstrate that apparent vortex-like motions in photospheric magnetic field concentrations do not exhibit 'tornado'-like behavior or a 'bath-tub' effect. While at each time instance the velocity field lines in the upper layers of the solar photosphere show swirls, the test particles moving with the time-dependent velocity field do not demonstrate such structures. Instead, they move in a wave-like fashion with rapidly changing and oscillating velocity field, determined mainly by magnetic tension in the magnetized intergranular downflows. Using time-distance diagrams, we identify horizontal motions in the magnetic flux tubes as torsional Alfvén perturbations propagating along the nearly vertical magnetic field lines with local Alfvén speed.

Shelyag, S.; Cally, P. S. [Monash Centre for Astrophysics, School of Mathematical Sciences, Monash University, Victoria 3800 (Australia)] [Monash Centre for Astrophysics, School of Mathematical Sciences, Monash University, Victoria 3800 (Australia); Reid, A.; Mathioudakis, M. [Astrophysics Research Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN (United Kingdom)] [Astrophysics Research Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN (United Kingdom)

2013-10-10T23:59:59.000Z

399

Characterization of mechanical properties of a hollow cylinder with zero group velocity Lamb modes  

Science Journals Connector (OSTI)

Hollow cylinders used in the industry must be regularly inspected. Elasticguided waves similar to Lamb modes in a plate can propagate in the axial direction or around the circumference. They are sensitive to geometrical and mechanical parameters of the cylindrical shell. The objective of this paper is to show that zero group velocity (ZGV) Lamb modes can be used to bring out anisotropy and to measureelastic constants of the material. This study provides experimental and numerical investigations on a Zirconium alloy tube extensively used by the nuclear industry in reactor core components. A non-contact method based on laser ultrasound techniques and ZGV Lamb modes demonstrates that the difference observed between axial and circumferential guided waves cannot be explained by an isotropic model. Then a transverse isotropic model is used for the Zircaloy tube. Four of the five elastic constants are directly extracted from ZGV resonance frequencies. The last one is deduced from the measureddispersion spectra. With this complete set of constants a good agreement is obtained between theoretical and experimental dispersion curves for both axially and circumferentially propagating guided waves.

M. Cès; D. Royer; C. Prada

2012-01-01T23:59:59.000Z

400

Wave-wave interactions in solar type III radio bursts  

SciTech Connect

The high time resolution observations from the STEREO/WAVES experiment show that in type III radio bursts, the Langmuir waves often occur as localized magnetic field aligned coherent wave packets with durations of a few ms and with peak intensities well exceeding the strong turbulence thresholds. Some of these wave packets show spectral signatures of beam-resonant Langmuir waves, down- and up-shifted sidebands, and ion sound waves, with frequencies, wave numbers, and tricoherences satisfying the resonance conditions of the oscillating two stream instability (four wave interaction). The spectra of a few of these wave packets also contain peaks at f{sub pe}, 2f{sub pe} and 3 f{sub pe} (f{sub pe} is the electron plasma frequency), with frequencies, wave numbers and bicoherences (computed using the wavelet based bispectral analysis techniques) satisfying the resonance conditions of three wave interactions: (1) excitation of second harmonic electromagnetic waves as a result of coalescence of two oppositely propagating Langmuir waves, and (2) excitation of third harmonic electromagnetic waves as a result of coalescence of Langmuir waves with second harmonic electromagnetic waves. The implication of these findings is that the strong turbulence processes play major roles in beam stabilization as well as conversion of Langmuir waves into escaping radiation in type III radio bursts.

Thejappa, G. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); MacDowall, R. J. [NASA/Goddard Space Flight Center, Greenbelt MD 20771 (United States)

2014-02-11T23:59:59.000Z

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.


401

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

402

Free–energy landscape and the critical velocity of superfluid films  

Science Journals Connector (OSTI)

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

2004-01-01T23:59:59.000Z

403

Linear wave propagation in relativistic magnetohydrodynamics  

Science Journals Connector (OSTI)

The properties of linear Alfvén slow and fast magnetoacoustic waves for uniform plasmas in relativistic magnetohydrodynamics(MHD) are discussed augmenting the well-known expressions for their phase speeds with knowledge on the group speed. A 3 + 1 formalism is purposely adopted to make direct comparison with the Newtonian MHD limits easier and to stress the graphical representation of their anisotropic linear wave properties using the phase and group speed diagrams. By drawing these for both the fluid rest frame and for a laboratory Lorentzian frame which sees the plasma move with a three-velocity having an arbitrary orientation with respect to the magnetic field a graphical view of the relativistic aberrationeffects is obtained for all three MHD wave families. Moreover it is confirmed that the classical Huygens construction relates the phase and group speed diagram in the usual way even for the lab frame viewpoint. Since the group speed diagrams correspond to exact solutions for initial conditions corresponding to a localized point perturbation their formulae and geometrical construction can serve to benchmark current high-resolution algorithms for numerical relativistic MHD.

R. Keppens; Z. Meliani

2008-01-01T23:59:59.000Z

404

Linear wave propagation in relativistic magnetohydrodynamics  

E-Print Network (OSTI)

The properties of linear Alfv\\'en, slow, and fast magnetoacoustic waves for uniform plasmas in relativistic magnetohydrodynamics (MHD) are discussed, augmenting the well-known expressions for their phase speeds with knowledge on the group speed. A 3+1 formalism is purposely adopted to make direct comparison with the Newtonian MHD limits easier and to stress the graphical representation of their anisotropic linear wave properties using the phase and group speed diagrams. By drawing these for both the fluid rest frame and for a laboratory Lorentzian frame which sees the plasma move with a three-velocity having an arbitrary orientation with respect to the magnetic field, a graphical view of the relativistic aberration effects is obtained for all three MHD wave families. Moreover, it is confirmed that the classical Huygens construction relates the phase and group speed diagram in the usual way, even for the lab frame viewpoint. Since the group speed diagrams correspond to exact solutions for initial conditions co...

Keppens, R

2008-01-01T23:59:59.000Z

405

Linear wave propagation in relativistic magnetohydrodynamics  

SciTech Connect

The properties of linear Alfven, slow, and fast magnetoacoustic waves for uniform plasmas in relativistic magnetohydrodynamics (MHD) are discussed, augmenting the well-known expressions for their phase speeds with knowledge on the group speed. A 3+1 formalism is purposely adopted to make direct comparison with the Newtonian MHD limits easier and to stress the graphical representation of their anisotropic linear wave properties using the phase and group speed diagrams. By drawing these for both the fluid rest frame and for a laboratory Lorentzian frame which sees the plasma move with a three-velocity having an arbitrary orientation with respect to the magnetic field, a graphical view of the relativistic aberration effects is obtained for all three MHD wave families. Moreover, it is confirmed that the classical Huygens construction relates the phase and group speed diagram in the usual way, even for the lab frame viewpoint. Since the group speed diagrams correspond to exact solutions for initial conditions corresponding to a localized point perturbation, their formulae and geometrical construction can serve to benchmark current high-resolution algorithms for numerical relativistic MHD.

Keppens, R. [Centre for Plasma-Astrophysics, K.U. Leuven, Celestijnenlaan 200B, 3001 Heverlee (Belgium); Leuven Mathematical Modeling and Computational Science Centre, K.U. Leuven (Belgium); FOM-Institute for Plasma Physics, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands) and Astronomical Institute, Utrecht University (Netherlands); Meliani, Z. [Centre for Plasma-Astrophysics, K.U. Leuven, Celestijnenlaan 200B, 3001 Heverlee (Belgium)

2008-10-15T23:59:59.000Z

406

Linear wave propagation in relativistic magnetohydrodynamics  

E-Print Network (OSTI)

The properties of linear Alfv\\'en, slow, and fast magnetoacoustic waves for uniform plasmas in relativistic magnetohydrodynamics (MHD) are discussed, augmenting the well-known expressions for their phase speeds with knowledge on the group speed. A 3+1 formalism is purposely adopted to make direct comparison with the Newtonian MHD limits easier and to stress the graphical representation of their anisotropic linear wave properties using the phase and group speed diagrams. By drawing these for both the fluid rest frame and for a laboratory Lorentzian frame which sees the plasma move with a three-velocity having an arbitrary orientation with respect to the magnetic field, a graphical view of the relativistic aberration effects is obtained for all three MHD wave families. Moreover, it is confirmed that the classical Huygens construction relates the phase and group speed diagram in the usual way, even for the lab frame viewpoint. Since the group speed diagrams correspond to exact solutions for initial conditions corresponding to a localized point perturbation, their formulae and geometrical construction can serve to benchmark current high-resolution algorithms for numerical relativistic MHD.

R. Keppens; Z. Meliani

2008-10-14T23:59:59.000Z

407

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 st...

Dolla, L

2008-01-01T23:59:59.000Z

408

SEISMIC WAVES ESTIMATION AND WAVE FIELD DECOMPOSITION WITH FACTOR GRAPHS  

E-Print Network (OSTI)

SEISMIC WAVES ESTIMATION AND WAVE FIELD DECOMPOSITION WITH FACTOR GRAPHS Stefano Maranò Christoph, Dept. Information Technology & Electr. Eng., 8092 Zürich ABSTRACT Physical wave fields are often from sensors of different kinds. In this paper we propose a technique for the analysis of vector wave

Loeliger, Hans-Andrea

409

Taming water waves Case study: Surface Water Waves  

E-Print Network (OSTI)

Taming water waves Case study: Surface Water Waves Few things in nature are as dramatic, and potentially dangerous, as ocean waves. The impact they have on our daily lives extends from shipping to the role they play in driving the global climate. From a theoretical viewpoint water waves pose rich

410

Selfconsistent full wave simulations of lower hybrid waves  

E-Print Network (OSTI)

Selfconsistent full wave simulations of lower hybrid waves John C. Wright P. T. Bonoli MIT E .J. Porkolab Sherwood/Spring APS Denver May 2009 #12; 2 Participants in the Center for Simulation of Wave hybrid (LH) waves have the attractive property of damping strongly via electron Landau resonance

Wright, John C.

411

On Generating Gravity Waves with Matter and Electromagnetic Waves  

E-Print Network (OSTI)

If a homogeneous plane light-like shell collides head-on with a homogeneous plane electromagnetic shock wave having a step-function profile then no backscattered gravitational waves are produced. We demonstrate, by explicit calculation, that if the matter is accompanied by a homogeneous plane electromagnetic shock wave with a step-function profile then backscattered gravitational waves appear after the collision.

C. Barrabes; P. A. Hogan

2008-04-05T23:59:59.000Z

412

Ultrafast ignition with relativistic shock waves induced by high power lasers  

E-Print Network (OSTI)

In this paper we consider laser intensities larger than $10^{16} W/cm^2$ where the ablation pressure is negligible in comparison with the radiation pressure. The radiation pressure is caused by the ponderomotive force acting mainly on the electrons that are separated from the ions to create a double layer (DL). This DL is accelerated into the target, like a piston that pushes the matter in such a way that a shock wave is created. Here we discuss two novel ideas. First is the transition domain between the relativistic and non-relativistic laser induced shock waves. Our solution is based on relativistic hydrodynamics also for the above transition domain. The relativistic shock wave parameters, such as compression, pressure, shock wave and particle flow velocities, sound velocity and rarefaction wave velocity in the compressed target, and the temperature are calculated. Secondly, we would like to use this transition domain for shock wave induced ultrafast ignition of a pre-compressed target. The laser parameters...

Eliezer, Shalom; Pinhasi, Shirly Vinikman; Raicher, Erez; Val, José Maria Martinez

2014-01-01T23:59:59.000Z

413

Variational Methods and the Nuclear Many-Body Problem  

Science Journals Connector (OSTI)

The general form of the energy of the ground state of a many-fermion system is shown to be exactly of the form proposed by Brueckner and Bethe, without approximation. In a variational treatment, if the trial wave function is picked containing only pair correlations, together with all possible unlinked pairs, it is described by a two-body excitation matrix ?m1m2|A|p1p2?. Variation of this matrix in the Ritz-Rayleigh principle yields a set of integral equations of the scattering type for the matrix A. Hole-state energies are given self-consistently in terms of the matrix A, but particle-state energies are Hartree-Fock energies. This may be corrected for by widely enlarging the class of terms admitted into the wave function. If the approximation is then made of omitting a class of terms, defined as cross-linked clusters in ??|H|??, the particle-state energies are easily renormalized. Variation then leads to an infinite hierarchy of integral equations.

R. Brout

1958-09-01T23:59:59.000Z

414

Determination of hydrogen cluster velocities and comparison with numerical calculations  

SciTech Connect

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

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

2013-12-21T23:59:59.000Z

415

Velocity of Second Sound in NaF  

Science Journals Connector (OSTI)

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

Robert J. Hardy and S. S. Jaswal

1971-06-15T23:59:59.000Z

416

Hydrocarbon saturation determination using acoustic velocities obtained through casing  

DOE Patents (OSTI)

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

Moos, Daniel (Houston, TX)

2010-03-09T23:59:59.000Z

417

Comparing Glider Observed Velocities and Geostrophic Currents Regina Yopak  

E-Print Network (OSTI)

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

Kurapov, Alexander

418

On the Structure of the Low Velocity Zone  

Science Journals Connector (OSTI)

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

Donald V. Helmberger

1973-11-01T23:59:59.000Z

419

Tsallis Entropy Based Velocity Distribution in Open Channel Flows  

E-Print Network (OSTI)

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

Luo, Hao

2010-07-14T23:59:59.000Z

420

The role of tides in shelf-scale simulations of the wave energy resource  

Science Journals Connector (OSTI)

Abstract Many regions throughout the world that are suitable for exploitation of the wave energy resource also experience large tidal ranges and associated strong tidal flows. However, tidal effects are not included in the majority of modelling studies which quantify the wave energy resource. This research attempts to quantify the impact of tides on the wave energy resource of the northwest European shelf seas, a region with a significant wave energy resource, and where many wave energy projects are under development. Results of analysis based on linear wave theory, and the application of a non-linear coupled wave-tide model (SWAN–ROMS), suggest that the impact of tides is significant, and can exceed 10% in some regions of strong tidal currents (e.g. headlands). Results also show that the effect of tidal currents on the wave resource is much greater than the contribution of variations in tidal water depth, and that regions which experience lower wave energy (and hence shorter wave periods) are more affected by tides than high wave energy regions. While this research provides general guidelines on the scale of the impact in regions of strong tidal flow, high resolution site-specific coupled wave-tide models are necessary for more detailed analysis.

M. Reza Hashemi; Simon P. Neill

2014-01-01T23:59:59.000Z

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.


421

Neoclassical generation of toroidal zonal flow by drift wave turbulence  

SciTech Connect

Zonal-flow instabilities due to drift-wave turbulence in the presence of toroidicity-induced parallel (neoclassical) viscosity and allowing for the toroidal flow are studied. It is shown that, as a result of the neoclassical viscosity a new type of zonal-flow instability is possible, leading to the generation of the considerable toroidal zonal flow. The toroidal instability is complementary to the previously studied instability resulting in the poloidal flow generation and occurs as a second branch of the general dispersion relation describing the evolution of the poloidal and toroidal flow. Nonlinear saturation of the new instability is studied. It is shown that saturated zonal toroidal velocity, generated in this instability, is large compared to the mean cross-field drift velocity as the ratio q/{epsilon}, where q is the safety factor and {epsilon} is the inverse aspect ratio. In addition to the broad turbulent spectrum of drift waves, a monochromatic wave packet is considered. It is revealed that for the case of sufficiently strong neoclassical viscosity such a wave packet is subjected to generation of the toroidal zonal flow due to instability of hydrodynamic type.

Mikhailovskii, A.B.; Smolyakov, A.I.; Tsypin, V.S.; Kovalishen, E.A.; Shirokov, M.S.; Galvao, R.M.O. [Institute of Nuclear Fusion, Russian Research Centre Kurchatov Institute, Kurchatov Sq., 1, Moscow 123182 (Russian Federation) and Nonlinear Physics Laboratory, Moscow Institute of Physics and Technology, Institutskii per. 9, Dolgoprudnyi 141700, Moscow Region (Russian Federation); University of Saskatchewan, 116 Science place, Saskatoon S7N 5E2 (Canada) and Institute of Nuclear Fusion, Russian Research Centre Kurchatov Institute, Kurchatov Sq., 1, Moscow 123182 (Russian Federation); Physics Institute, University of Sao Paulo, Cidade Universitaria, 05508-900, Sao Paulo (Brazil); Nonlinear Physics Laboratory, Moscow Institute of Physics and Technology, Institutskii per. 9, Dolgoprudnyi 141700, Moscow Region (Russian Federation) and Institute of Nuclear Fusion, Russian Research Centre Kurchatov Institute, Kurchatov Sq., 1, Moscow 123182 (Russian Federation); Institute of Nuclear Fusion, Russian Research Centre Kurchatov Institute, Kurchatov Sq., 1, Moscow 123182 (Russian Federation) and Moscow Engineering Physics Institute, Kashirskoe Shosse 31, Moscow 115409 (Russian Federation); Physics Institute, University of Sao Paulo, Cidade Universitaria, 05508-900, Sao Paulo (Brazil) and Brazilian Center for Research in Physics, Rua Xavier Sigaud, 150, 22290-180, Rio de Janeiro (Brazil)

2006-03-15T23:59:59.000Z

422

MEASUREMENTS OF ANISOTROPIC ION TEMPERATURES, NON-THERMAL VELOCITIES, AND DOPPLER SHIFTS IN A CORONAL HOLE  

SciTech Connect

We present a new diagnostic allowing one to measure the anisotropy of ion temperatures and non-thermal velocities, as well as Doppler shifts with respect to the ambient magnetic field. This method provides new results, as well as an independent test for previous measurements obtained with other techniques. Our spectral data come from observations of a low-latitude, on-disk coronal hole. A potential field source surface model was used to calculate the angle between the magnetic field lines and the line of sight for each spatial bin of the observation. A fit was performed to determine the line widths and Doppler shifts parallel and perpendicular to the magnetic field. For each line width component we derived ion temperatures T {sub i,} and T {sub i, Parallel-To} and non-thermal velocities v {sub nt,} and v {sub nt, Parallel-To }. T {sub i,} was cooler than off-limb polar coronal hole measurements, suggesting increasing collisional cooling with decreasing height. T {sub i, Parallel-To} is consistent with a uniform temperature of (1.8 {+-} 0.2) Multiplication-Sign 10{sup 6} K for each ion. Since parallel ion heating is expected to be weak, this ion temperature should reflect the proton temperature. A comparison between our results and others implies a large proton temperature gradient around 1.02 R {sub Sun }. The non-thermal velocities are thought to be proportional to the amplitudes of various waves. Our results for v {sub nt,} agree with Alfven wave amplitudes inferred from off-limb polar coronal hole line width measurements. Our v {sub nt, Parallel-To} results are consistent with slow magnetosonic wave amplitudes inferred from Fourier analysis of time-varying intensity fluctuations. Doppler shift measurements yield outflows of Almost-Equal-To 5 km s{sup -1} for ions formed over a broad temperature range. This differs from other studies that found a strong Doppler shift dependence on formation temperature.

Hahn, M.; Savin, D. W. [Columbia Astrophysics Laboratory, Columbia University, MC 5247, 550 West 120th Street, New York, NY 10027 (United States)] [Columbia Astrophysics Laboratory, Columbia University, MC 5247, 550 West 120th Street, New York, NY 10027 (United States)

2013-02-15T23:59:59.000Z

423

Tracking moving radar targets with parallel, velocity-tuned filters  

DOE Patents (OSTI)

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

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

2013-04-30T23:59:59.000Z

424

Detection of electron velocity in graphene by Doppler effect  

Science Journals Connector (OSTI)

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

Heetae Kim; Chang-Soo Park; Hak Dong Cho

2014-01-01T23:59:59.000Z

425

Precision Measuring of Velocities via the Relativistic Doppler Effect  

E-Print Network (OSTI)

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

Leonid M. Ozernoy

1997-12-26T23:59:59.000Z

426

Characteristics of ion-acoustic solitary wave in a laboratory dusty plasma under the influence of ion-beam  

SciTech Connect

We study the influence of ion beam and charged dust impurity on the propagation of dust ion-acoustic solitary wave in an unmagnetized plasma consisting of Boltzmann distributed electrons, positive ions, positive ion beam, and negatively charged immobile dusts in a double plasma device. On interacting with an ion beam, the solitary wave is bifurcated into a compressive fast and a rarefactive slow beam mode, and appears along with the primary wave. However, there exists a critical velocity of the beam beyond which the amplitude of the fast solitary wave starts diminishing and rarefactive slow beam mode propagates with growing amplitude. Whereas, the presence of charged dust impurity in the plasma reduces this critical beam velocity and a substantial modification in the phase velocity of the slow beam mode is observed with increasing dust density. Furthermore, the nonlinear wave velocity (Mach number) as well as the width of the compressive solitons are measured for different beam velocity and dust density, and are compared with those obtained from the K-dV equation. The experimental results are found in a well agreement with the theoretical predictions.

Deka, M. K.; Adhikary, N. C.; Bailung, H. [Physical Sciences Division, Institute of Advanced Study in Science and Technology, Vigyan Path, Paschim Boragaon, Garchuk, Guwahati 781035, Assam (India); Misra, A. P. [Department of Mathematics, Siksha Bhavana, Visva-Bharati University, Santiniketan 731 235 (India); Nakamura, Y. [Department of Physics, Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501 (Japan)

2012-10-15T23:59:59.000Z

427

WaveBob (TRL 5 6 System) - Advanced Wave Energy Conversion Project...  

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

WaveBob (TRL 5 6 System) - Advanced Wave Energy Conversion Project WaveBob (TRL 5 6 System) - Advanced Wave Energy Conversion Project WaveBob (TRL 5 6 System) - Advanced Wave...

428

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

429

Sound Waves in the Atmosphere at Infrasonic Frequencies  

Science Journals Connector (OSTI)

Various geophysical processes generate sound waves in the atmosphere. Some typical sources are auroral discharges in the upper atmosphere tornadoes and severe storms surface waves on the oceans volcanic explosions earthquakes and atmospheric oscillations arising from unstable wind flow at the tropopause. Man?made sources include powerful explosions and the shock waves from vehicles moving at supersonic speeds at altitudes below about 125 km. The components of sound?wave energy at infrasonic frequencies (oscillation periods >1.0 sec) are propagated for large distances (thousands of kilometers) over the earth's surface with very little loss of energy from absorption by viscosity and heat conduction. But the propagation depends strongly on (a) the horizontally stratified temperature structure of the atmosphere (b) the influence of gravity at oscillation periods greater than the atmospheric resonance period ?300 sec and (c) the nonuniform distribution of atmospheric winds. The microphones and electroacoustical apparatus at an infrasonics observation station e.g. the one at Washington D. C. measure (1) the amplitude and waveform of incident sound pressure (2) the direction of local propagation of the wave (3) the horizontal trace velocity and (4) the distribution of sound wave energy at various oscillation frequencies. Researches on propagation require observational data from a network of stations separated geographically by large distances coupled with theoretical analysis of sound propagation to arrive at useful results on the acoustics of the atmosphere.

Richard K. Cook

1972-01-01T23:59:59.000Z

430

Detonation wave driven by condensation of supersaturated carbon vapor  

Science Journals Connector (OSTI)

An experimental observation of a detonation wave driven by the energy of condensation of supersaturated carbon vapor is reported. The carbon vapor was formed by the thermal decay of unstable carbon suboxide C3O2 behind shock waves in mixtures containing 10–30% C3O2 in Ar. In the mixture 10% C3O2+Ar the insufficient heat release resulted in a regime of overdriven detonation. In the mixture 20% C3O2+Ar measured values of the pressure and wave velocity coincident with calculated Chapman-Jouguet parameters were attained. In the richest mixture 30% C3O2+Ar an excess heat release caused the slowing down of the condensation rate and the regime of underdriven detonation was observed.

A. Emelianov; A. Eremin; V. Fortov; H. Jander; A. Makeich; H. Gg. Wagner

2009-03-10T23:59:59.000Z

431

Surface wave dynamics in orbital shaken cylindrical containers  

E-Print Network (OSTI)

Be it to aerate a glass of wine before tasting, to accelerate a chemical reaction or to cultivate cells in suspension, the "swirling" (or orbital shaking) of a container ensures good mixing and gas exchange in an efficient and simple way. Despite being used in a large range of applications this intuitive motion is far from being understood and presents a richness of patterns and behaviors which has not yet been reported. The present research charts the evolution of the waves with the operating parameters identifying a large variety of patterns, ranging from single and multiple crested waves to breaking waves. Free surface and velocity fields measurements are compared to a potential sloshing model, highlighting the existence of various flow regimes. Our research assesses the importance of the modal response of the shaken liquids, laying the foundations for a rigorous mixing optimization of the orbital agitation in its applications. Copyright (2014) American Institute of Physics. This article may be downloaded ...

Reclari, Martino; Tissot, Stéphanie; Obreschkow, Danail; Wurm, Florian Maria; Farhat, Mohamed

2014-01-01T23:59:59.000Z

432

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

433

Mathematical Caricature of Large Waves  

E-Print Network (OSTI)

The Kadomtsev-Petviiashvili equation is considered as a mathematical caricature of large and rogue waves.

Mikhail Kovalyov

2014-03-21T23:59:59.000Z

434

Clustering of floaters by waves  

E-Print Network (OSTI)

We study experimentally how waves affect distribution of particles that float on a water surface. We show that clustering of small particles in a standing wave is a nonlinear effect with the clustering time decreasing as the square of the wave amplitude. In a set of random waves, we show that small floaters concentrate on a multi-fractal set.

P. Denissenko; G. Falkovich; S. Lukaschuk

2005-11-22T23:59:59.000Z

435

December 2010 | 23 GUIDED WAVES  

E-Print Network (OSTI)

December 2010 | 23 GUIDED WAVES Tuning Wave Dispersion in Resonant Networks Eyal Feigenbaum with meta-atoms. Resonant guided wave networks (RGWNs) are a new class of artificial photonic material,5 distinct from photonic crystals and metamateri- als, in which localized waves resonate in closed paths

Atwater, Harry

436

Multiple-frequency acoustic wave devices for chemical sensing and materials characterization in both gas and liquid phase  

DOE Patents (OSTI)

A chemical or intrinsic physical property sensor is described comprising: (a) a substrate; (b) an interaction region of said substrate where the presence of a chemical or physical stimulus causes a detectable change in the velocity and/or an attenuation of an acoustic wave traversing said region; and (c) a plurality of paired input and output interdigitated electrodes patterned on the surface of said substrate where each of said paired electrodes has a distinct periodicity, where each of said paired electrodes is comprised of an input and an output electrode; (d) an input signal generation means for transmitting an input signal having a distinct frequency to a specified input interdigitated electrode of said plurality so that each input electrode receives a unique input signal, whereby said electrode responds to said input signal by generating an acoustic wave of a specified frequency, thus, said plurality responds by generating a plurality of acoustic waves of different frequencies; (e) an output signal receiving means for determining an acoustic wave velocity and an amplitude of said acoustic waves at several frequencies after said waves transverses said interaction region and comparing these values to an input acoustic wave velocity and an input acoustic wave amplitude to produce values for perturbations in acoustic wave velocities and for acoustic wave attenuation as a function of frequency, where said output receiving means is individually coupled to each of said output interdigitated electrode; (f) a computer means for analyzing a data stream comprising information from said output receiving means and from said input signal generation means to differentiate a specified response due to a perturbation from a subsequent specified response due to a subsequent perturbation to determine the chemical or intrinsic physical properties desired.

Martin, S.J.; Ricco, A.J.

1993-08-10T23:59:59.000Z

437

Selection Rules for the Nonlinear Interactions of Internal Gravity Waves and Inertia-Gravity Waves  

E-Print Network (OSTI)

Internal Gravity Waves . . . . . . . . . . . . . . 3.2.1 Twodimensional inertia-gravity wave physics . . . . . . . . .Three dimensional inertia-gravity wave physics . . . . . .

Jiang, Chung-Hsiang

2010-01-01T23:59:59.000Z

438

Various Boussinesq solitary wave solutions  

SciTech Connect

The generalized Boussinesq (gB) equations have been used to model nonlinear wave evolution over variable topography and wave interactions with structures. Like the KdV equation, the gB equations support a solitary wave solution which propagates without changing shape, and this solitary wave is often used as a primary test case for numerical studies of nonlinear waves using either the gB or other model equations. Nine different approximate solutions of the generalized Boussinesq equations are presented with simple closed form expressions for the wave elevation and wave speed. Each approximates the free propagation of a single solitary wave, and eight of these solutions are newly obtained. The author compares these solutions with the well known KdV solution, Rayleigh`s solution, Laitone`s higher order solution, and ``exact`` numerical integration of the gB equations. Existing experimental data on solitary wave shape and wave speed are compared with these models.

Yates, G.T. [Univ. of Hong Kong (Hong Kong). Dept. of Mechanical Engineering

1995-12-31T23:59:59.000Z

439

The flexural wave?number response of a string and a beam subjected to a moving harmonic force  

Science Journals Connector (OSTI)

The effect of a moving harmonic force that acts upon either a string or a beam is analyzed according to its spectral wave?number components and the decaying components of the flexural vibrations. The speed of motion of the force is nondimensionalized with respect to the wave flexural speed. For a string the wave number of the right traveling disturbance increases monotonically at subsonic speeds; at supersonic speeds both wave numbers lead to left traveling waves which decrease as a function of Mach number. For a beam the effect of the motion is to produce one right traveling wave with an everincreasing wave number and three disturbances which propagate and decay behind the forcing function. The decaying modes at a Mach number of two become traveling modes. The critical Mach number of two corresponds to a speed of the force equal to the group velocity at that frequency.

Mauro Pierucci

1993-01-01T23:59:59.000Z

440

Compound Effect of Alfv\\'en Waves and Ion-cyclotron Waves on Heating/Acceleration of Minor Ions via the Pickup Process  

E-Print Network (OSTI)

A scenario is proposed to explain the preferential heating of minor ions and differential streaming velocity between minor ions and protons observed in the solar corona and in the solar wind. It is demonstrated by test particle simulations that minor ions can be nearly fully picked up by intrinsic Alfv\\'en-cyclotron waves observed in the solar wind based on the observed wave energy density. Both high frequency ion-cyclotron waves and low frequency Alfv\\'en waves play crucial roles in the pickup process. A minor ion can first gain a high magnetic moment through the resonant wave-particle interaction with ion-cyclotron waves, and then this ion with a large magnetic moment can be trapped by magnetic mirror-like field structures in the presence of the lower-frequency Alfv\\'en waves. As a result, the ion is picked up by these Alfv\\'en-cyclotron waves. However, minor ions can only be partially picked up in the corona due to low wave energy density and low plasma beta. During the pickup process, minor ions are stoch...

Wang, C B; Lee, L C

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "wave velocity variations" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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to obtain the most current and comprehensive results.


441

Is the San Andreas Fracture a bayonet-shaped fracture as inferred from the acoustic body waves in the SAFOD Pilot hole ?  

E-Print Network (OSTI)

a vertical borehole has been applied to the granitic formation penetrated by the SAFOD Pilot hole near, such as the presence of a fault zone of low shear wave velocity, stress rotation measured with depth, and the large. Keywords San Andreas Fault, Borehole, acoustic body waves, in situ stress, anisotropy. Introduction

Boyer, Edmond

442

Noise sustained waves in subexcitable media: From chemical waves to brain waves  

E-Print Network (OSTI)

Noise sustained waves in subexcitable media: From chemical waves to brain waves P. Junga: a subexcitable photosensitive Belousov­Zhabotinsky reaction, hippocampal slices of rat brains, and astrocyte of such a behavior for calcium wave net- works in interconnected brain cells. I. INTRODUCTION Since the early days

Showalter, Kenneth

443

The role of damped Alfven waves on magnetospheric accretion models of young stars  

E-Print Network (OSTI)

We examine the role of Alfven wave damping in heating the plasma in the magnetic funnels of magnetospheric accretion models of young stars. We study four different damping mechanisms of the Alfven waves: nonlinear, turbulent, viscous-resistive and collisional. Two different possible origins for the Alfven waves are discussed: 1) Alfven waves generated at the surface of the star by the shock produced by the infalling matter; and 2) Alfven waves generated locally in the funnel by the Kelvin-Helmholtz instability. We find that, in general, the damping lengths are smaller than the tube length. Since thermal conduction in the tube is not efficient, Alfven waves generated only at the star's surface cannot heat the tube to the temperatures necessary to fit the observations. Only for very low frequency Alfven waves ~10^{-5} the ion cyclotron frequency, is the viscous-resistive damping length greater than the tube length. In this case, the Alfven waves produced at the surface of the star are able to heat the whole tube. Otherwise, local production of Alfven waves is required to explain the observations. The turbulence level is calculated for different frequencies for optically thin and thick media. We find that turbulent velocities varies greatly for different damping mechanisms, reaching \\~100 km s^{-1} for the collisional damping of small frequency waves.

M. J. Vasconcelos; V. Jatenco-Pereira; R. Opher

2002-04-03T23:59:59.000Z

444

HOMOLOGOUS EXTREME ULTRAVIOLET WAVES IN THE EMERGING FLUX REGION OBSERVED BY THE SOLAR DYNAMICS OBSERVATORY  

SciTech Connect

Taking advantage of the high temporal and spatial resolution of the Solar Dynamics Observatory (SDO) observations, we present four homologous extreme ultraviolet (EUV) waves within 3 hr on 2010 November 11. All EUV waves emanated from the same emerging flux region (EFR), propagated in the same direction, and were accompanied by surges, weak flares, and faint coronal mass ejections (CMEs). The waves had the basically same appearance in all EUV wavebands of the Atmospheric Imaging Assembly on SDO. The waves propagated at constant velocities in the range of 280-500 km s{sup -1}, with little angular dependence, which indicated that the homologous waves could be likely interpreted as fast-mode waves. The waves are supposed to likely involve more than one driving mechanism, and it was most probable that the waves were driven by the surges, due to their close timing and location relations. We also propose that the homologous waves were intimately associated with the continuous emergence and cancellation of magnetic flux in the EFR, which could supply sufficient energy and trigger the onsets of the waves.

Zheng Ruisheng; Jiang Yunchun; Yang Jiayan; Bi Yi; Hong Junchao; Yang, B.; Yang Dan, E-mail: zhrsh@ynao.ac.cn [National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, Kunming 650011 (China)

2012-03-01T23:59:59.000Z

445

Electron acceleration by Z-mode and whistler-mode waves  

SciTech Connect

We carried out a series of particle simulations to study electron acceleration by Z-mode and whistler-mode waves generated by an electron ring distribution. The electron ring distribution leads to excitations of X-mode waves mainly in the perpendicular direction, Z-mode waves in the perpendicular and parallel directions, and whistler-mode waves mainly in the parallel direction. The parallel Z- and whistler-mode waves can lead to an effective acceleration of ring electrons. The electron acceleration is mainly determined by the wave amplitude and phase velocity, which in turn is affected by the ratio of electron plasma to cyclotron frequencies. For the initial kinetic energy ranging from 100 to 500 keV, the peak energy of the accelerated electrons is found to reach 2–8 times the initial kinetic energy. We further study the acceleration process by test-particle calculations in which electrons interact with one, two, or four waves. The electron trajectories in the one-wave case are simple diffusion curves. In the multi-wave cases, electrons are accelerated simultaneously by counter-propagating waves and can have a higher final energy.

Lee, K. H. [Institute of Space Science, National Central University, Zhongli, Taiwan (China)] [Institute of Space Science, National Central University, Zhongli, Taiwan (China); Omura, Y. [Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Kyoto (Japan)] [Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Kyoto (Japan); Lee, L. C. [Institute of Space Science, National Central University, Zhongli, Taiwan (China) [Institute of Space Science, National Central University, Zhongli, Taiwan (China); Institute of Earth Science, Academia Sinica, Nankang, Taiwan (China)

2013-11-15T23:59:59.000Z

446

Ultrasonic velocity measurements for synthetic gas?hydrate samples  

Science Journals Connector (OSTI)

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

2006-01-01T23:59:59.000Z

447

Propagation of cylindrical lower hybrid drift solitary wave in an inhomogeneous plasma  

SciTech Connect

The nonlinear cylindrical lower hybrid drift solitary wave in an inhomogeneous, magnetized plasma with the combined effects of electron density inhomogeneity and electron temperature inhomogeneity is investigated in a two-fluid model. The amplitude and width of the solitary wave are found to decrease as the electronic density inhomogeneity increases. When the electron temperature inhomogeneity grows, the amplitude of the soliton decays and the width never changes. It is noted that the decrease of diamagnetic drift velocity will strengthen the cylindrical lower hybrid drift solitary wave height and width.

Liu Haifeng; Wang Shiqing; Fazhan Yang [Southwestern Institute of Physics, Chengdu 610041 (China); Engineering and Technical College of Chengdu University of Technology, Leshan 614000 (China); Li Kehua; Wang Zhanhe; Zhang Weibing; Wang Zhilong; Qiangxiang; Kaihuang; Yaoliu; Silili; Lanchang [Engineering and Technical College of Chengdu University of Technology, Leshan 614000 (China)

2013-04-15T23:59:59.000Z

448

Comparison of wave hindcasts, using Wilson's method, with observation and with other hindcast methods  

E-Print Network (OSTI)

and period charact- erising the waves as they leave the generating area. Second is the determination of the travel time for the wave energy to reach the coast and the decrease in height and 1ncrease in per1od accompanying this travel over a region... Africa. Most of the work was done under United States Navy contract by Sverdrup snd Munk. From a study of the processes by which energy is transmitted from wind to ~aves, they der1ved the, energy relations which related wave height and velocity...

Srivastava, Parmatma Saran

2012-06-07T23:59:59.000Z

449

New Variational Method for the Free Energy  

Science Journals Connector (OSTI)

......New Variational Method for the Free Energy Akihide Oguchi Department of Physics...new variational method for the free energy in statistical physics is proposed. The value of the free energy obtained by using the new variational......

Akihide Oguchi

1984-06-01T23:59:59.000Z

450

Two-stream instability with time-dependent drift velocity  

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

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

2014-01-01T23:59:59.000Z

451

Millimetre-Wave Aperture Synthesis Radiometry for Snow and Ice Mapping Andy R Harvey1  

E-Print Network (OSTI)

surface salinity, soil moisture content and wind velocity [2]. Mechanical, mm-wave pencil beam scanners application to (1) mapping of snow and ice cover and (2) determination of ocean wind vector. The most mature that is push-broom scanned to form a two-dimensional image. Other candidate techniques are the Mills Cross [5

Harvey, Andy

452

Vortices and Rossby waves in cylinder wakes on a parabolic -plane observed by altimetric imaging velocimetry  

E-Print Network (OSTI)

, geostrophic and gradient wind velocity, and potential vorticity fields with very high spatial resolutionVortices and Rossby waves in cylinder wakes on a parabolic -plane observed by altimetric imaging in the wake of a circular cylinder are investigated in a rotating parabolic polar -plane fluid. This system

Afanassiev, Iakov

453

Cyclotron Waves in a Nonneutral Plasma Column Daniel H.E. Dubin  

E-Print Network (OSTI)

plasma column with near-Maxwellian velocity distributions. We focus on the z-independent componentCyclotron Waves in a Nonneutral Plasma Column Daniel H.E. Dubin Department of Physics, University of California at San Diego, La Jolla, California 92093 (Dated: February 22, 2013 [submitted to Phys. Plasmas

California at San Diego, University of

454

Cyclotron waves in a non-neutral plasma column Daniel H. E. Dubin  

E-Print Network (OSTI)

plasma column with near-Maxwellian velocity distributions. We focus on the z-independent componentCyclotron waves in a non-neutral plasma column Daniel H. E. Dubin Citation: Phys. Plasmas 20. Additional information on Phys. Plasmas Journal Homepage: http://pop.aip.org/ Journal Information: http

California at San Diego, University of

455

Relativistic Electron Beam Acceleration by Compton Scattering of Lower-Hybrid Waves  

E-Print Network (OSTI)

and cyclotron damping of the lower-hybrid waves. 1. INTRODUCTION Acceleration and heating of a relativistic and cyclotron damping)4,5 , ( ) cek k v m - - - =k k , (1) where , is the parallel velocity ) is the relativistic electron cyclotron frequency, and ism an integer. The relativistic transport equations using

Boyer, Edmond

456

Coda-wave interferometry analysis of time-lapse VSP data for monitoring geological carbon sequestration  

SciTech Connect

Injection and movement/saturation of carbon dioxide (CO2) in a geological formation will cause changes in seismic velocities. We investigate the capability of coda-wave interferometry technique for estimating CO2-induced seismic velocity changes using time-lapse synthetic vertical seismic profiling (VSP) data and the field VSP datasets acquired for monitoring injected CO2 in a brine aquifer in Texas, USA. Synthetic VSP data are calculated using a finite-difference elastic-wave equation scheme and a layered model based on the elastic Marmousi model. A possible leakage scenario is simulated by introducing seismic velocity changes in a layer above the CO2 injection layer. We find that the leakage can be detected by the detection of a difference in seismograms recorded after the injection compared to those recorded before the injection at an earlier time in the seismogram than would be expected if there was no leakage. The absolute values of estimated mean velocity changes, from both synthetic and field VSP data, increase significantly for receiver positions approaching the top of a CO2 reservoir. Our results from field data suggest that the velocity changes caused by CO2 injection could be more than 10% and are consistent with results from a crosswell tomogram study. This study demonstrates that time-lapse VSP with coda-wave interferometry analysis can reliably and effectively monitor geological carbon sequestration.

Zhou, R.; Huang, L.; Rutledge, J.T.; Fehler, M.; Daley, T.M.; Majer, E.L.

2009-11-01T23:59:59.000Z

457

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

458

Measurement of sound speed vs. depth in South Pole ice: pressure waves and shear waves  

SciTech Connect

We have measured the speed of both pressure waves and shear waves as a function of depth between 80 and 500 m depth in South Pole ice with better than 1% precision. The measurements were made using the South Pole Acoustic Test Setup (SPATS), an array of transmitters and sensors deployed in the ice at the South Pole in order to measure the acoustic properties relevant to acoustic detection of astrophysical neutrinos. The transmitters and sensors use piezoceramics operating at {approx}5-25 kHz. Between 200 m and 500 m depth, the measured profile is consistent with zero variation of the sound speed with depth, resulting in zero refraction, for both pressure and shear waves. We also performed a complementary study featuring an explosive signal propagating vertically from 50 to 2250 m depth, from which we determined a value for the pressure wave speed consistent with that determined for shallower depths, higher frequencies, and horizontal propagation with the SPATS sensors. The sound speed profile presented here can be used to achieve good acoustic source position and emission time reconstruction in general, and neutrino direction and energy reconstruction in particular. The reconstructed quantities could also help separate neutrino signals from background.

IceCube Collaboration; Klein, Spencer

2009-06-04T23:59:59.000Z

459

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

460

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

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461

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 +

462

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 +

463

Experimental High Velocity Acid Jetting in Limestone Carbonates  

E-Print Network (OSTI)

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

Holland, Christopher

2014-04-30T23:59:59.000Z

464

Effect of Adhesive Tape on the Velocity Profile of Water  

Science Journals Connector (OSTI)

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

ALAN E. COSSAR

1970-09-05T23:59:59.000Z

465

Direct and precise measurement of displacement and velocity of flexible web in roll-to-roll manufacturing systems  

SciTech Connect

Interest in the production of printed electronics using a roll-to-roll system has gradually increased due to its low mass-production costs and compatibility with flexible substrate. To improve the accuracy of roll-to-roll manufacturing systems, the movement of the web needs to be measured precisely in advance. In this paper, a novel measurement method is developed to measure the displacement and velocity of the web precisely and directly. The proposed algorithm is based on the traditional single field encoder principle, and the scale grating has been replaced with a printed grating on the web. Because a printed grating cannot be as accurate as a scale grating in a traditional encoder, there will inevitably be variations in pitch and line-width, and the motion of the web should be measured even though there are variations in pitch and line-width in the printed grating patterns. For this reason, the developed algorithm includes a precise method of estimating the variations in pitch. In addtion, a method of correcting the Lissajous curve is presented for precision phase interpolation to improve measurement accuracy by correcting Lissajous circle to unit circle. The performance of the developed method is evaluated by simulation and experiment. In the experiment, the displacement error was less than 2.5 ?m and the velocity error of 1? was about 0.25%, while the grating scale moved 30 mm.

Kang, Dongwoo; Lee, Eonseok; Choi, Young-Man; Lee, Taik-Min [Advanced Manufacturing Systems Research Division, Korea Institute of Machinery and Materials, 156 Gajeongbuk-Ro, Yuseong-Gu, Daejeon 305-343 (Korea, Republic of)] [Advanced Manufacturing Systems Research Division, Korea Institute of Machinery and Materials, 156 Gajeongbuk-Ro, Yuseong-Gu, Daejeon 305-343 (Korea, Republic of); Kim, Duk Young [Nano-Opto-Mechatronics Lab., Dept. of Mechanical Eng., KAIST, 335 Gwahangno, Yuseong