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1

wave power density | OpenEI  

Open Energy Info (EERE)

power density power density 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 (2 years ago) Date Updated Unknown Keywords EPRI MHK NREL ocean Virginia Tech wave wave power density Data application/pdf icon Download Full Report (pdf, 8.8 MiB) Quality Metrics Level of Review Some Review Comment

2

Effect of electron density profile on power absorption of high frequency electromagnetic waves in plasma  

SciTech Connect

Considering different typical electron density profiles, a multi slab approximation model is built up to study the power absorption of broadband (0.75-30 GHz) electromagnetic waves in a partially ionized nonuniform magnetized plasma layer. Based on the model, the power absorption spectra for six cases are numerically calculated and analyzed. It is shown that the absorption strongly depends on the electron density fluctuant profile, the background electron number density, and the collision frequency. A potential optimum profile is also analyzed and studied with some particular parameters.

Xi Yanbin; Liu Yue [MOE Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

2012-07-15T23:59:59.000Z

3

Charge Density Wave Compounds  

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

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

4

Global coherence of dust density waves  

SciTech Connect

The coherence of self-excited three-dimensional dust density waves has been experimentally investigated by comparing global and local wave properties. For that purpose, three-dimensional dust clouds have been confined in a radio frequency plasma with thermophoretic levitation. Global wave properties have been measured from the line-of-sight integrated dust density obtained from homogenous light extinction measurements. Local wave properties have been obtained from thin, two-dimensional illuminated laser slices of the cloud. By correlating the simultaneous global and local wave properties, the spatial coherence of the waves has been determined. We find that linear waves with small amplitudes tend to be fragmented, featuring an incoherent wave field. Strongly non-linear waves with large amplitudes, however, feature a strong spatial coherence throughout the dust cloud, indicating a high level of synchronization.

Killer, Carsten; Melzer, André [Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald (Germany)

2014-06-15T23:59:59.000Z

5

Definition: Power density | Open Energy Information  

Open Energy Info (EERE)

density density Jump to: navigation, search Dictionary.png Power density The rate of energy flow (power) per unit volume, area or mass. Common metrics include: horsepower per cubic inch, watts per square meter and watts per kilogram.[1][2] View on Wikipedia Wikipedia Definition Power density (or volume power density or volume specific power) is the amount of power (time rate of energy transfer) per unit volume. In energy transformers like batteries, fuel cells, motors, etc. but also power supply units or similar, power density refers to a volume. It is then also called volume power density which is expressed as W/m. Volume power density is sometimes an important consideration where space is constrained. In reciprocated internal combustion engines, power density- power per swept

6

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

7

Advanced, High Power, Next Scale, Wave Energy Conversion Device...  

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

Advanced, High Power, Next Scale, Wave Energy Conversion Device Advanced, High Power, Next Scale, Wave Energy Conversion Device Advanced, High Power, Next Scale, Wave Energy...

8

Hydrodynamic principles of wave power extraction  

Science Journals Connector (OSTI)

...Based on statistical data, Thorpe [12] has estimated the wave power potential along various...and K. Budal1982Wave-power absorption by parallel...de2008Phase control through load control of oscillating-body...and C. C. Mei2009Wave power extraction by a compact...

2012-01-01T23:59:59.000Z

9

Energy-momentum Density of Gravitational Waves  

E-Print Network (OSTI)

In this paper, we elaborate the problem of energy-momentum in general relativity by energy-momentum prescriptions theory. Our aim is to calculate energy and momentum densities for the general form of gravitational waves. In this connection, we have extended the previous works by using the prescriptions of Bergmann and Tolman. It is shown that they are finite and reasonable. In addition, using Tolman prescription, exactly, leads to same results that have been obtained by Einstein and Papapetrou prescriptions.

Amir M. Abbassi; Saeed Mirshekari

2014-11-29T23:59:59.000Z

10

Density waves in a transverse electric field  

Science Journals Connector (OSTI)

In a quasi-one-dimensional conductor with an open Fermi surface, a charge- or a spin-density-wave phase can be destroyed by an electric field perpendicular to the direction of high conductivity. This mechanism, due to the breakdown of electron-hole symmetry, is very similar to the orbital destruction of superconductivity by a magnetic field, due to time-reversal symmetry.

Gilles Montambaux

1996-12-15T23:59:59.000Z

11

Energy-Momentum Density of Gravitational Waves  

E-Print Network (OSTI)

In this paper, we elaborate the problem of energy-momentum in general relativity by energy-momentum prescriptions theory. Our aim is to calculate energy and momentum densities for the general form of gravitational waves. In this connection, we have extended the previous works by using the prescriptions of Bergmann and Tolman. It is shown that they are finite and reasonable. In addition, using Tolman prescription, exactly, leads to same results that have been obtained by Einstein and Papapetrou prescriptions.

Amir M. Abbassi; Saeed Mirshekari

2009-08-03T23:59:59.000Z

12

Limit cycle analysis of nuclear coupled density-wave oscillations  

SciTech Connect

Recent tests at commercial boiling water reactors (BWRs) have demonstrated the existence of limit cycles for nuclear coupled density-wave oscillations (NCDWOs) at off-normal conditions. This paper presents the application of a simplified nonlinear BWR core model to determine the potential magnitude and limiting mechanisms of severe NCDWOs, and an approximate determination of the limit cycle using singular perturbation analysis. In this model, the point kinetics equation with infinite-delayed approximation and linear reactivity feedback to both fuel temperature and coolant density is used. This model correctly predicts the magnitude of the Vermont Yankee power oscillations.

Ward, M.E.; Lee, J.C.

1986-01-01T23:59:59.000Z

13

Power recycling for an interferometric gravitational wave  

E-Print Network (OSTI)

THESIS Power recycling for an interferometric gravitational wave detector Masaki Ando Department . . . . . . . . . . . . . . 48 3.3 Power recycling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 3.3.1 Principle of power recycling . . . . . . . . . . . . . . . . . 50 3.3.2 Recycling cavity

Ejiri, Shinji

14

Wave Power Demonstration Project at Reedsport, Oregon  

SciTech Connect

Ocean wave power can be a significant source of large?scale, renewable energy for the US electrical grid. The Electrical Power Research Institute (EPRI) conservatively estimated that 20% of all US electricity could be generated by wave energy. Ocean Power Technologies, Inc. (OPT), with funding from private sources and the US Navy, developed the PowerBuoy? to generate renewable energy from the readily available power in ocean waves. OPT's PowerBuoy converts the energy in ocean waves to electricity using the rise and fall of waves to move the buoy up and down (mechanical stroking) which drives an electric generator. This electricity is then conditioned and transmitted ashore as high?voltage power via underwater cable. OPT's wave power generation system includes sophisticated techniques to automatically tune the system for efficient conversion of random wave energy into low cost green electricity, for disconnecting the system in large waves for hardware safety and protection, and for automatically restoring operation when wave conditions normalize. As the first utility scale wave power project in the US, the Wave Power Demonstration Project at Reedsport, OR, will consist of 10 PowerBuoys located 2.5 miles off the coast. This U.S. Department of Energy Grant funding along with funding from PNGC Power, an Oregon?based electric power cooperative, was utilized for the design completion, fabrication, assembly and factory testing of the first PowerBuoy for the Reedsport project. At this time, the design and fabrication of this first PowerBuoy and factory testing of the power take?off subsystem are complete; additionally the power take?off subsystem has been successfully integrated into the spar.

Mekhiche, Mike [Principal Investigator] [Principal Investigator; Downie, Bruce [Project Manager] [Project Manager

2013-10-21T23:59:59.000Z

15

Considering Air Density in Wind Power Production  

E-Print Network (OSTI)

In the wind power production calculations the air density is usually considered as constant in time. Using the CIPM-2007 equation for the density of moist air as a function of air temperature, air pressure and relative humidity, we show that it is worth taking the variation of the air density into account, because higher accuracy can be obtained in the calculation of the power production for little effort.

Farkas, Zénó

2011-01-01T23:59:59.000Z

16

Considering Air Density in Wind Power Production  

E-Print Network (OSTI)

In the wind power production calculations the air density is usually considered as constant in time. Using the CIPM-2007 equation for the density of moist air as a function of air temperature, air pressure and relative humidity, we show that it is worth taking the variation of the air density into account, because higher accuracy can be obtained in the calculation of the power production for little effort.

Zénó Farkas

2011-03-11T23:59:59.000Z

17

Nonlocal theory of electromagnetic wave decay into two electromagnetic waves in a rippled density plasma channel  

SciTech Connect

Parametric decay of a large amplitude electromagnetic wave into two electromagnetic modes in a rippled density plasma channel is investigated. The channel is taken to possess step density profile besides a density ripple of axial wave vector. The density ripple accounts for the momentum mismatch between the interacting waves and facilitates nonlinear coupling. For a given pump wave frequency, the requisite ripple wave number varies only a little w.r.t. the frequency of the low frequency decay wave. The radial localization of electromagnetic wave reduces the growth rate of the parametric instability. The growth rate decreases with the frequency of low frequency electromagnetic wave.

Sati, Priti; Tripathi, V. K. [Indian Institute of Technology, Hauz Khas, Delhi 110054 (India)

2012-12-15T23:59:59.000Z

18

Kinetic Wave Power | Open Energy Information  

Open Energy Info (EERE)

Wave Power Address: 2861 N Tupelo St Place: Midland Zip: 48642 Region: United States Sector: Marine and Hydrokinetic Phone Number: 989-839-9757 Website: http:...

19

Wave Power Plant Inc | Open Energy Information  

Open Energy Info (EERE)

Powered Compressed Air Stations This article is a stub. You can help OpenEI by expanding it. Retrieved from "http:en.openei.orgwindex.php?titleWavePowerPlantInc&oldid76915...

20

Fabrication of nanoscale charge density wave systems  

Science Journals Connector (OSTI)

Nanoscale charge density wave systems of quasi-one-dimensional o ? TaS 3 crystals were fabricated.Goldelectrodes 400 nm wide were made by standard lift-off technique on o ? TaS 3 nanocrystals prepared by deposition on silicon substrates. Interface resistance was higher than 100 G ? just after evaporation and were significantly reduced by electron-beam irradiation. The electrodes were tested down to 80 mK and were found quite durable for cryogenic measurement. The temperature dependence of the resistance of the nanocrystal was represented as the variable-range-hopping-type conduction with one dimension over the wide range of temperature from 4.2 to 100 K. This behavior was different from that of conventional bulk samples.

Katsuhiko Inagaki; Takeshi Toshima; Satoshi Tanda; Kazuhiko Yamaya; Shinya Uji

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "wave power density" 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

Wave Power: Destroyer of Rocks; Creator of Clean Energy  

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

E E PG&E Wave Energy Wave Energy Federal Utility Partnership Federal Utility Partnership Working Group Meeting Working Group Meeting Wave Energy Wave Energy Development Development Ontario, CA Ontario, CA November 18 November 18- -19, 200 19, 2009 9 Donald G. Price Donald G. Price Senior Consulting Scientist, PG&E Senior Consulting Scientist, PG&E Wave Power Overview Wave Power Overview * * What is Wave Power? What is Wave Power? o o Wave power or wave energy is the energy contained in ocean Wave power or wave energy is the energy contained in ocean o o Wave power or wave energy is the energy contained in ocean Wave power or wave energy is the energy contained in ocean waves that is converted into electricity by various means. waves that is converted into electricity by various means. o o It is a clean, renewable energy resource capable of being utilized

22

High-power-density spot cooling using bulk thermoelectrics  

E-Print Network (OSTI)

3D electrothermal model, the cooling power densities of themax , and increasing the cooling power densities 2–24 times.the advantages of high cooling power densities and is less

Zhang, Y; Shakouri, A; Zeng, G H

2004-01-01T23:59:59.000Z

23

Hydrodynamic principles of wave power extraction  

Science Journals Connector (OSTI)

...Despite the abundance of wave power in the sea, technologies...extraction share with offshore wind power at least two similar challenges...present, the estimated power-generating capacity of...20-40 buoys to match a wind turbine of 2MW capacity...

2012-01-01T23:59:59.000Z

24

MHK Technologies/Yongsoo Wave Power Plant | Open Energy Information  

Open Energy Info (EERE)

Yongsoo Wave Power Plant < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Yongsoo Wave Power Plant.jpg Technology Profile Technology Type Click...

25

Measuring Tiny Waves with High Power Particle Beams | Princeton...  

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

Measuring Tiny Waves with High Power Particle Beams American Fusion News Category: U.S. Universities Link: Measuring Tiny Waves with High Power Particle Beams...

26

Floating type ocean wave power station equipped with hydroelectric unit  

Science Journals Connector (OSTI)

The authors have invented the unique ocean wave power station, which is composed of the floating ... wave pitch and the counter-rotating type wave power unit, its runners are submerged in the ... as requested, be...

Shun Okamoto; Toshiaki Kanemoto; Toshihiko Umekage

2013-10-01T23:59:59.000Z

27

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

28

Offshore wave power measurements—A review  

Science Journals Connector (OSTI)

The first wave power patent was filed in 1799. Since then, hundreds of ideas for extraction of energy from ocean waves have surfaced. In the process of developing a concept, it is important to learn from previous successes and failures, and this is not least important when moving into the ocean. In this paper, a review has been made with the purpose of finding wave power projects that have made ocean trials, and that also have reported what has been measured during the trials, and how it has been measured. In relation to how many projects have done work on wave power, surprisingly few have reported on such measurements. There can be many reasons for this, but one is likely the great difficulties in working with experiments in an ocean environment. Many of the projects have reported on sensor failures, unforeseen events, and other general problems in making measurements at sea. The most common site measurement found in this review was wave height. Such measurements was almost universal, although the technologies used differed somewhat. The most common device measurements were electric voltages and/or currents and system pressures (air and water). Device motion and mooring forces were also commonly measured. The motion measurements differed the most between the projects, and many varying methods were used, such as accelerometers, wire sensors, GPS systems, optical systems and echo sounders.

Simon Lindroth; Mats Leijon

2011-01-01T23:59:59.000Z

29

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

30

Metal-insulator Transition by Holographic Charge Density Waves  

E-Print Network (OSTI)

We construct a gravity dual for charge density waves (CDW) in which the translational symmetry along one spatial direction is spontaneously broken. Our linear perturbation calculation on the gravity side produces the frequency dependence of the optical conductivity, which exhibits the two familiar features of charge density waves, namely the pinned collective mode and gapped single-particle excitation. These two features indicate that our gravity dual also provides a new mechanism to implement the metal to insulator phase transition by CDW, which is further supported by the fact that d.c. conductivity decreases with the decreased temperature below the critical temperature.

Yi Ling; Chao Niu; Jianpin Wu; Zhuoyu Xian; Hongbao Zhang

2014-04-03T23:59:59.000Z

31

Columbia Power Technologies, Inc. Deploys its Direct Drive Wave...  

Energy Savers (EERE)

Columbia Power Technologies, Inc. Deploys its Direct Drive Wave Energy Buoy Columbia Power Technologies, Inc. Deploys its Direct Drive Wave Energy Buoy April 9, 2013 - 12:00am...

32

Theoretical power density from salinity gradients using reverse electrodialysis  

Science Journals Connector (OSTI)

Reverse electrodialysis (RED) is a technology to generate power from mixing waters with different salinity. The net power density (i.e. power per membrane area) is determined by 1) the membrane potential, 2) the ohmic resistance, 3) the resistance due to changing bulk concentrations, 4) the boundary layer resistance and 5) the power required to pump the feed water. Previous power density estimations often neglected the latter three terms. This paper provides a set of analytical equations to estimate the net power density obtainable from RED stacks with spacers and RED stacks with profiled membranes. With the current technology, the obtained maximum net power density is calculated at 2.7 W/m2. Higher power densities could be obtained by changing the cell design, in particular the membrane resistance and the cell length. Changing these parameters one and two orders of magnitude respectively, the calculated net power density is close to 20 W/m2.

David A. Vermaas; Enver Guler; Michel Saakes; Kitty Nijmeijer

2012-01-01T23:59:59.000Z

33

Inverter System Design and Control for a Wave Power Substation.  

E-Print Network (OSTI)

?? This Master thesis has been performed as part of the Lysekil wave power project at the Division of Electricity, Uppsala University. Power electronics, placed… (more)

Ekström, Rickard

2009-01-01T23:59:59.000Z

34

New Wave Power Project In Oregon | Department of Energy  

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

Wave Power Project In Oregon Wave Power Project In Oregon New Wave Power Project In Oregon June 17, 2011 - 3:12pm Addthis Mike Reed Water Power Program Manager, Water Power Program What does this project do? Promises to add tremendous value to the wave energy industry, reinforcing utility-scale viability, collecting ground-breaking environmental impact data and exploring avenues for cost reduction. Has issued localized manufacturing contracts for the PB150 to several Oregon companies. If you've ever been surfing, or gone swimming in choppy water, you've experienced first-hand the striking power of waves. In fact, further offshore, wave activity becomes even more powerful, making it an excellent resource for generating clean, renewable energy. That's exactly what the Department of Energy and its partner Ocean Power Technologies (OPT) are

35

wind power density | OpenEI  

Open Energy Info (EERE)

density density Dataset Summary Description This dataset was developed by the National Renewable Energy Laboratory (NREL) for the U.S. Source National Renewable Energy Lab (NREL) Date Released Unknown Date Updated Unknown Keywords afghanistan dataset GIS Wind Power wind power density Data application/zip icon Wind Power Density at 50-m Above Ground Level GIS Data (zip, 1.4 MiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Time Period License License Other or unspecified, see optional comment below Comment DISCLAIMER NOTICE This GIS data was developed by the National Renewable Energy Laboratory ("NREL"), which is operated by the Alliance for Sustainable Energy, LLC for the U.S. Department of Energy ("DOE"). The user is granted the right, without any fee or cost, to use, copy, modify, alter, enhance and distribute this data for any purpose whatsoever, provided that this entire notice appears in all copies of the data. Further, the user of this data agrees to credit NREL in any publications or software that incorporate or use the data. Access to and use of the GIS data shall further impose the following obligations on the User. The names DOE/NREL may not be used in any advertising or publicity to endorse or promote any product or commercial entity using or incorporating the GIS data unless specific written authorization is obtained from DOE/NREL. The User also understands that DOE/NREL shall not be obligated to provide updates, support, consulting, training or assistance of any kind whatsoever with regard to the use of the GIS data. THE GIS DATA IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL DOE/NREL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER, INCLUDING BUT NOT LIMITED TO CLAIMS ASSOCIATED WITH THE LOSS OF DATA OR PROFITS, WHICH MAY RESULT FROM AN ACTION IN CONTRACT, NEGLIGENCE OR OTHER TORTIOUS CLAIM THAT ARISES OUT OF OR IN CONNECTION WITH THE ACCESS OR USE OF THE GIS DATA. The User acknowledges that access to the GIS data is subject to U.S. Export laws and regulations and any use or transfer of the GIS data must be authorized under those regulations. The User shall not use, distribute, transfer, or transmit GIS data or any products incorporating the GIS data except in compliance with U.S. export regulations. If requested by DOE/NREL, the User agrees to sign written assurances and other export-related documentation as may be required to comply with U.S. export regulations. DISCLAIMER NOTICE This GIS data was developed by the National Renewable Energy Laboratory ("NREL"), which is operated by the Alliance for Sustainable Energy, LLC for the U.S. Department of Energy ("DOE"). The user is granted the right, without any fee or cost, to use, copy, modify, alter, enhance and distribute this data for any purpose whatsoever, provided that this entire notice appears in all copies of the data. Further, the user of this data agrees to credit NREL in any publications or software that incorporate or use the data. Access to and use of the GIS data shall further impose the following obligations on the User. The names DOE/NREL may not be used in any advertising or publicity to endorse or promote any product or commercial entity using or incorporating the GIS data unless specific written authorization is obtained from DOE/NREL. The User also understands that DOE/NREL shall not be obligated to provide updates, support, consulting, training or assistance of any kind whatsoever with regard to the use of the GIS data. THE GIS DATA IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL DOE/NREL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER, INCLUDING BUT NOT LIMITED TO CLAIMS ASSOCIATED WITH THE LOSS OF DATA OR PROFITS, WHICH MAY RESULT FROM AN ACTION IN CONTRACT, NEGLIGENCE OR OTHER TORTIOUS CLAIM THAT ARISES OUT OF OR IN CONNECTION WITH THE ACCESS OR USE OF THE GIS DATA. The User acknowledges that access to the GIS data is subject to U.S. Export laws and regulations and any use or transfer of the GIS data must be authorized under those regulations. The User shall not use, distribute, transfer, or transmit GIS data or any products incorporating the GIS data except in compliance with U.S. export regulations. If requested by DOE/NREL, the User agrees to sign written assurances and other export-related documentation as may be required to comply with U.S. export regulations.

36

Design and Control of High Power Density Motor Drive.  

E-Print Network (OSTI)

??This dissertation aims at developing techniques to achieve high power density in motor drives under the performance requirements for transportation system. Four main factors influencing… (more)

Jiang, Dong

2011-01-01T23:59:59.000Z

37

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

38

Estimating the potential of ocean wave power resources  

Science Journals Connector (OSTI)

The realistic assessment of an ocean wave energy resource that can be converted to an electrical power at various offshore sites depends upon many factors, and these include estimating the resource recognizing the random nature of the site-specific wave field, and optimizing the power conversion from particular wave energy conversion devices. In order to better account for the uncertainty in wave power resource estimates, conditional probability distribution functions of wave power in a given sea-state are derived. Theoretical expressions for the deep and shallow water limits are derived and the role of spectral width is studied. The theoretical model estimates were compared with the statistics obtained from the wave-by-wave analysis of JONSWAP based ocean wave time-series. It was shown that the narrow-band approximation is appropriate when the variability due to wave period is negligible. The application of the short-term models in evaluating the long-term wave power resource at a site was illustrated using wave data measured off the California coast. The final example illustrates the procedure for incorporating the local wave data and the sea-state model together with a wave energy device to obtain an estimate of the potential wave energy that could be converted into a usable energy resource.

Amir H. Izadparast; John M. Niedzwecki

2011-01-01T23:59:59.000Z

39

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

40

NO FLARES FROM GAMMA-RAY BURST AFTERGLOW BLAST WAVES ENCOUNTERING SUDDEN CIRCUMBURST DENSITY CHANGE  

SciTech Connect

Afterglows of gamma-ray bursts are observed to produce light curves with the flux following power-law evolution in time. However, recent observations reveal bright flares at times on the order of minutes to days. One proposed explanation for these flares is the interaction of a relativistic blast wave with a circumburst density transition. In this paper, we model this type of interaction computationally in one and two dimensions, using a relativistic hydrodynamics code with adaptive mesh refinement called RAM, and analytically in one dimension. We simulate a blast wave traveling in a stellar wind environment that encounters a sudden change in density, followed by a homogeneous medium, and compute the observed radiation using a synchrotron model. We show that flares are not observable for an encounter with a sudden density increase, such as a wind termination shock, nor for an encounter with a sudden density decrease. Furthermore, by extending our analysis to two dimensions, we are able to resolve the spreading, collimation, and edge effects of the blast wave as it encounters the change in circumburst medium. In all cases considered in this paper, we find that a flare will not be observed for any of the density changes studied.

Gat, Ilana; Van Eerten, Hendrik; MacFadyen, Andrew [Center for Cosmology and Particle Physics, Physics Department, New York University, New York, NY 10003 (United States)

2013-08-10T23:59:59.000Z

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


41

Wave Power: Destroyer of Rocks; Creator of Clean Energy  

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

Presentation covers the topic of wave power at the Federal Utility Partnership Working Group (FUPWG) meeting, held on November 18-19, 2009.

42

Sandia National Laboratories: convert wave power into electricity  

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

wave power into electricity WEC-Sim Code Development Meeting at the National Renewable Energy Laboratory On April 29, 2014, in Computational Modeling & Simulation, Energy, News,...

43

MHK Technologies/SyncWave Power Resonator | Open Energy Information  

Open Energy Info (EERE)

Power Resonator Power Resonator < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage SyncWave Power Resonator.jpg Technology Profile Primary Organization Marinus Power Technology Resource Click here Wave Technology Type Click here Point Absorber - Floating Technology Readiness Level Click here TRL 1 3 Discovery Concept Def Early Stage Dev Design Engineering Technology Description The SyncWave Power Resonator makes power by capturing the motion differential due to the phase lag between the two concentric float structures the Float and the Spar each having a very different resonance characteristic in waves The power generated from this phase lag is maximized under varying ocean wave conditions via a proprietary variable inertia tuning system SWELS located inside the central Spar Power is captured by an hydraulic power take off which drives a variable speed generator Power outputs conditioned by modern power electronics from several SyncWave Units in a wave farm will be collected and converted to in farm power in a sea bed mounted collector hub then transmitted ashore by subsea cable for interconnection to a shoreside load

44

Grating formation by a high power radio wave in near-equator ionosphere  

SciTech Connect

The formation of a volume grating in the near-equator regions of ionosphere due to a high power radio wave is investigated. The radio wave, launched from a ground based transmitter, forms a standing wave pattern below the critical layer, heating the electrons in a space periodic manner. The thermal conduction along the magnetic lines of force inhibits the rise in electron temperature, limiting the efficacy of heating to within a latitude of few degrees around the equator. The space periodic electron partial pressure leads to ambipolar diffusion creating a space periodic density ripple with wave vector along the vertical. Such a volume grating is effective to cause strong reflection of radio waves at a frequency one order of magnitude higher than the maximum plasma frequency in the ionosphere. Linearly mode converted plasma wave could scatter even higher frequency radio waves.

Singh, Rohtash; Sharma, A. K.; Tripathi, V. K. [Department of Physics, Indian Institute of Technology Delhi, New Delhi-110016 (India)

2011-11-15T23:59:59.000Z

45

High Energy Density Science with High Peak Power Light Sources  

Science Journals Connector (OSTI)

High energy density (HED) science is a growing sub-field of plasma and condensed matter physics. I will examine how recent technological developments in high peak power, petawatt-class...

Ditmire, Todd

46

Magnetohydrodynamic density waves in a composite disc system of interstellar medium and cosmic ray gas  

Science Journals Connector (OSTI)

......Dispersion Relations of Spiral mhd density waves Parker first investigated...hydromagnetic waves using the MHD perturbation equations in a thermal...that there is a in the phase diagram for the fast mode in the direction...alone (Appendix B). For spiral MHD density waves in a thin self-gravitating......

Yu-Qing Lou; Zuhui Fan

2003-05-21T23:59:59.000Z

47

MHK Technologies/Float Wave Electric Power Station | Open Energy  

Open Energy Info (EERE)

Wave Electric Power Station Wave Electric Power Station < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Float Wave Electric Power Station.jpg Technology Profile Primary Organization Applied Technologies Company Ltd Technology Resource Click here Wave Technology Type Click here Point Absorber - Floating Technology Readiness Level Click here TRL 5 6 System Integration and Technology Laboratory Demonstration Technology Description The module of FWEPS is an oblong axisymmetrical capsule float which is located on the sea surface Inside the capsule there is a mechanical wave energy converter consisting of an oscillatory system and drive and an electric generator and energy accumulator Under the wave effect the capsule float and inner oscillatory system of the mechanical converter are in continuous oscillatory motion while the drive engaged with the system provides a continuous turn for the electric generator

48

Evidence against a charge density wave on Bi(111)  

SciTech Connect

The Bi(111) surface was studied by scanning tunneling microscopy (STM), transmission electron microscopy (TEM) and angle-resolved photoemission (ARPES) in order to verify the existence of a recently proposed surface charge density wave (CDW) [Ch. R. Ast and H. Hoechst Phys. Rev. Lett. 90, 016403 (2003)]. The STM and TEM results to not support a CDW scenario at low temperatures. Furthermore, the quasiparticle interference pattern observed in STM confirms the spin-orbit split character of the surface states which prevents the formation of a CDW, even in the case of good nesting. The dispersion of the electronic states observed with ARPES agrees well with earlier findings. In particular, the Fermi contour of the electron pocket at the centre of the surface Brillouin zone is found to have a hexagonal shape. However, no gap opening or other signatures of a CDW phase transition can be found in the temperature-dependent data.

Kim, T.K.; Wells, J.; Kirkegaard, C.; Li, Z.; Hoffmann, S.V.; Gayone, J.E.; Fernancez-Torrente, I.; Haberle, P.; Pascual, J.I.; Moore,K.T.; Schwartz, A.J.; He, H.; Spence, J.C.H.; Downing, K.H.; Lazar, S.; Tichelaar, F.D.; Borisenko, S.V.; Knupfer, M.; Hofmann, Ph.

2005-05-01T23:59:59.000Z

49

Power Maximization in Wave-Energy Converters Using Sampled -Data Extremum Seeking /  

E-Print Network (OSTI)

Power Maximization in Wave-Energy Converters Using Sampled-design optimization of wave energy converters con- sistingN. Sahinkaya. A review of wave energy converter technology.

Chen, Tianjia

2013-01-01T23:59:59.000Z

50

On the application of circular–cylindrical waves to ocean wave power absorption  

Science Journals Connector (OSTI)

This study derives mathematical forms for the waves radiated from a heaving, surging and swaying point source on the surface of a three dimensional ocean. The interactions between a monochromatic plane wave and monochromatic circular–cylindrical radiated waves are examined, and solutions to the time averaged power are calculated. These calculations confirm pre-existing theoretical maximum absorption lengths for both a heaving and surging point source. The derivations also lead to the definition of the amplitude, phase and form of the radiated waves required to achieve these maximums. Two experimental case studies match measured radiated wave with circular waves. These matches demonstrate a correlation between the body motions and the dominant form of radiated waves as well as higher frequency waves. The study develops three general guidelines for the design of efficient point absorber wave energy converters (PAWECs). Optimum power absorption occurs when the PAWEC radiates theoretical heave and surge waves of the appropriate amplitude and phase. Theoretical sway type waves should be minimized as these radiate energy and do not interact with the incident wave. Similarly, the radiation of higher harmonic waves should also be minimized for the same reasons.

Matthew Wypych; Lan Le-Ngoc; Keith Alexander; Alister Gardner

2012-01-01T23:59:59.000Z

51

MHK Technologies/Gyroscopic wave power generation system | Open Energy  

Open Energy Info (EERE)

Gyroscopic wave power generation system Gyroscopic wave power generation system < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Technology Profile Primary Organization Gyrodynamics Corporation Technology Resource Click here Wave Technology Type Click here Attenuator Technology Readiness Level Click here TRL 5 6 System Integration and Technology Laboratory Demonstration Technology Description This gyroscopic wave power generation system is a pure rotational mechanical system that does not use conventional air turbines and is housed on a unique floating platform float In particular its outstanding feature is that it utilizes the gyroscopic spinning effect A motor is used to turn a 1 meter diameter steel disc flywheel inside the apparatus and when the rolling action of waves against the float tilts it at an angle the gyroscopic effect causes the disc to rotate longitudinally This energy turns a generator producing electricity

52

WAVE-ENERGY DENSITY AND WAVE-MOMENTUM DENSITY OF EACH SPECIES OF A COLLISION-LESS PLASMA  

E-Print Network (OSTI)

case, the electrons have negative wave energy for 2w ne w wave energy for 2w . > w > 0 nlw/k to the negative wave energy of the electrons. positive

Cary, John R.

2012-01-01T23:59:59.000Z

53

Protective, Modular Wave Power Generation System  

SciTech Connect

The concept of small wave energy conversion modules that can be built into large, scalable arrays, in the same vein as solar panels, has been developed. This innovation lends itself to an organic business and development model, and enables the use of large-run manufacturing technology to reduce system costs. The first prototype module has been built to full-scale, and tested in a laboratory wave channel. The device has been shown to generate electricity and dissipate wave energy. Improvements need to be made to the electrical generator and a demonstration of an array of modules should be made in natural conditions.

Vvedensky, Jane M.; Park, Robert Y.

2012-11-27T23:59:59.000Z

54

Scattering of Radio Frequency Waves by Edge Density Blobs in Tokamak Plasmas  

SciTech Connect

The density blobs and fluctuations present in the edge region of magnetic fusion devices can scatter radio frequency (RF) waves through refraction and diffraction. The scattering can diffuse the rays in space and in wave-vector space. The diffusion in space can make the rays miss their intended target region, while the diffusion in wave-vector space can broaden the wave spectrum and modify the wave damping and current profile.

Ram, A. K. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Hizanidis, K.; Kominis, Y. [National Technical University of Athens, Association EURATOM-Hellenic Republic, Zografou, Athens 15773 (Greece)

2011-12-23T23:59:59.000Z

55

The Effects of the Scattering by Edge Plasma Density Fluctuations on Lower Hyybrid Wave Propagation  

SciTech Connect

Scattering effects induced by edge density fluctuations on lower hybrid (LH) wave propagation are investigated. The scattering model used here is based on the work of Bonoli and Ott [Phys. Fluids 25 (1982) 361]. It utilizes an electromagnetic wave kinetic equation solved by a Monte Carlo technique. This scattering model has been implemented in GENRAY , a ray tracing code which explicitly simulates wave propagation, as well as collisionless and collisional damping processes, over the entire plasma discharge, including the scrape-off layer (SOL) that extends from the separatrix to the vessel wall. A numerical analysis of the LH wave trajectories and the power deposition profile with and without scattering is presented for Alcator CMod discharges. Comparisons between the measured hard x-ray emission on Alcator C-Mod and simulations of the data obtained from the synthetic diagnostic included in the GENRAY/CQL3D package are shown, with and without the combination of scattering and collisional damping. Implications of these results on LH current drive are discussed.

Bertelli, N; Bonoli, P T; Harvey, R W; Smirnov, A P; Baek, S G; Parker, R R; Phillips, C K; Valeo, E J; Wilson, J R

2012-08-27T23:59:59.000Z

56

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

57

Langlee Wave Power AS | Open Energy Information  

Open Energy Info (EERE)

Power AS Address: Smedsvingen 4 Entrance B 1st floor Place: Hvalstad Zip: 1395 Region: Norway Sector: Marine and Hydrokinetic Phone Number: +47 90044104 Website: http:...

58

Tapping into Wave and Tidal Ocean Power: 15% Water Power by 2030 |  

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

Tapping into Wave and Tidal Ocean Power: 15% Water Power by 2030 Tapping into Wave and Tidal Ocean Power: 15% Water Power by 2030 Tapping into Wave and Tidal Ocean Power: 15% Water Power by 2030 January 27, 2012 - 11:30am Addthis A map generated by Georgia Tech's tidal energy resource database shows mean current speed of tidal streams. The East Coast, as shown above, has strong tides that could be tapped to produce energy. | Photo courtesy of Georgia Institute of Technology A map generated by Georgia Tech's tidal energy resource database shows mean current speed of tidal streams. The East Coast, as shown above, has strong tides that could be tapped to produce energy. | Photo courtesy of Georgia Institute of Technology Hoyt Battey Water Power Market Acceleration and Deployment Team Lead, Wind and Water Power Program

59

High Power Superconducting Continuous Wave Linacs for Protons and  

Office of Science (SC) Website

Power Superconducting Continuous Power Superconducting Continuous Wave Linacs for Protons and Heavy-Ions Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Spinoff Applications Spinoff Archives SBIR/STTR Applications of Nuclear Science and Technology Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: sc.np@science.doe.gov More Information » Spinoff Archives High Power Superconducting Continuous Wave Linacs for Protons and Heavy-Ions Print Text Size: A A A RSS Feeds FeedbackShare Page Application/instrumentation: High Power Superconducting Continuous Wave Linacs for Protons and Heavy-Ions

60

Columbia Power Technologies, Inc. Deploys its Direct Drive Wave Energy Buoy  

Office of Energy Efficiency and Renewable Energy (EERE)

Columbia Power Technologies, Inc. is working to advance their wave energy buoy to commercial readiness.

Note: This page contains sample records for the topic "wave power density" 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

Inferring Magnetospheric Heavy Ion Density using EMIC Waves  

SciTech Connect

We present a method to infer heavy ion concentration ratios from EMIC wave observations that result from ionion hybrid (IIH) resonance. A key feature of the ion-ion hybrid resonance is the concentration of wave energy in a field-aligned resonant mode that exhibits linear polarization. This mode converted wave is localized at the location where the frequency of a compressional wave driver matches the IIH resonance condition, which depends sensitively on the heavy ion concentration. This dependence makes it possible to estimate the heavy ion concentration ratio. In this letter, we evaluate the absorption coefficients at the IIH resonance at Earth's geosynchronous orbit for variable concentrations of He+ and field-aligned wave numbers using a dipole magnetic field. Although wave absorption occurs for a wide range of heavy ion concentrations, it only occurs for a limited range of field-aligned wave numbers such that the IIH resonance frequency is close to, but not exactly the same as the crossover frequency. Using the wave absorption and observed EMIC waves from GOES-12 satellite, we demonstrate how this technique can be used to estimate that the He+ concentration is around 4% near L = 6.6.

Kim, Eun-Hwa; Johnson, Jay R.; Kim, Hyomin; Lee, Dong-Hun

2014-05-01T23:59:59.000Z

62

Gravitational wave generation in power-law inflationary models  

E-Print Network (OSTI)

We investigate the generation of gravitational waves in power-law inflationary models. The energy spectrum of the gravitational waves is calculated using the method of continuous Bogoliubov coefficients. We show that, by looking at the interval of frequencies between 10^(-5) and 10^5 Hz and also at the GHz range, important information can be obtained, both about the inflationary period itself and about the thermalization regime between the end of inflation and the beginning of the radiation-dominated era. We thus deem the development of gravitational wave detectors, covering the MHz/GHz range of frequencies, to be an important task for the future.

Paulo M. Sá; Alfredo B. Henriques

2008-06-06T23:59:59.000Z

63

Thermodynamic, Energy Efficiency, and Power Density Analysis of Reverse Electrodialysis Power Generation with Natural Salinity Gradients  

Science Journals Connector (OSTI)

Thermodynamic, Energy Efficiency, and Power Density Analysis of Reverse Electrodialysis Power Generation with Natural Salinity Gradients ... solns. of different salinities. ... River mouths are potentially abundant locations for the exploitation of the clean and renewable salinity gradient energy (SGE) as here perpetually fresh water mixes with saline seawater. ...

Ngai Yin Yip; David A. Vermaas; Kitty Nijmeijer; Menachem Elimelech

2014-04-03T23:59:59.000Z

64

Magnetocaloric materials and the optimization of cooling power density  

Science Journals Connector (OSTI)

Abstract The magnetocaloric effect is the thermal response of a material to an external magnetic field. This manuscript focuses on the physics and the properties of materials which are commonly used for magnetic refrigeration at cryogenic temperatures. After a brief overview of the magnetocaloric effect and associated thermodynamics, typical requirements on refrigerants are discussed from a standpoint of cooling power density optimization. Finally, a compilation of the most important properties of several common magnetocaloric materials is presented.

Patrick Wikus; Edgar Canavan; Sarah Trowbridge Heine; Koichi Matsumoto; Takenori Numazawa

2014-01-01T23:59:59.000Z

65

Advanced, High Power, Next Scale, Wave Energy Conversion Device  

SciTech Connect

The project conducted under DOE contract DE?EE0002649 is defined as the Advanced, High Power, Next Scale, Wave Energy Converter. The overall project is split into a seven?stage, gated development program. The work conducted under the DOE contract is OPT Stage Gate III work and a portion of Stage Gate IV work of the seven stage product development process. The project effort includes Full Concept Design & Prototype Assembly Testing building on our existing PowerBuoy? technology to deliver a device with much increased power delivery. Scaling?up from 150kW to 500kW power generating capacity required changes in the PowerBuoy design that addressed cost reduction and mass manufacturing by implementing a Design for Manufacturing (DFM) approach. The design changes also focused on reducing PowerBuoy Installation, Operation and Maintenance (IO&M) costs which are essential to reducing the overall cost of energy. In this design, changes to the core PowerBuoy technology were implemented to increase capability and reduce both CAPEX and OPEX costs. OPT conceptually envisaged moving from a floating structure to a seabed structure. The design change from a floating structure to seabed structure would provide the implementation of stroke? unlimited Power Take?Off (PTO) which has a potential to provide significant power delivery improvement and transform the wave energy industry if proven feasible.

Mekhiche, Mike [Principal Investigator] [Principal Investigator; Dufera, Hiz [Project Manager] [Project Manager; Montagna, Deb [Business Point of Contact] [Business Point of Contact

2012-10-29T23:59:59.000Z

66

Using Radio Waves to Control Fusion Plasma Density  

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

simulation shows turbulent density fluctuations in the core of the Alcator C-Mod tokamak during strong electron heating. Image: Darin Ernst, MIT Recent fusion experiments on...

67

Model for Density Waves in Gravity-Driven Granular Flow in Narrow Pipes  

E-Print Network (OSTI)

A gravity-driven flow of grains through a narrow pipe in vacuum is studied by means of a one-dimensional model with two coefficients of restitution. Numerical simulations show clearly how density waves form when a strikingly simple criterion is fulfilled: that dissipation due to collisions between the grains and the walls of the pipe is greater per collision than that which stems from collisions between particles. Counterintuitively, the highest flow rate is observed when the number of grains per density wave grows large. We find strong indication that the number of grains per density wave always approaches a constant as the particle number tends to infinity, and that collapse to a single wave, which was often observed also in previous simulations, occurs because the number of grains is insufficient for multiple wave formation.

Ellingsen, Simen Å; Grøva, Morten; Hansen, Alex

2010-01-01T23:59:59.000Z

68

Model for Density Waves in Gravity-Driven Granular Flow in Narrow Pipes  

E-Print Network (OSTI)

A gravity-driven flow of grains through a narrow pipe in vacuum is studied by means of a one-dimensional model with two coefficients of restitution. Numerical simulations show clearly how density waves form when a strikingly simple criterion is fulfilled: that dissipation due to collisions between the grains and the walls of the pipe is greater per collision than that which stems from collisions between particles. Counterintuitively, the highest flow rate is observed when the number of grains per density wave grows large. We find strong indication that the number of grains per density wave always approaches a constant as the particle number tends to infinity, and that collapse to a single wave, which was often observed also in previous simulations, occurs because the number of grains is insufficient for multiple wave formation.

Simen Å. Ellingsen; Knut S. Gjerden; Morten Grøva; Alex Hansen

2010-01-05T23:59:59.000Z

69

Creation of nonlinear density gradients for use in internal wave research  

E-Print Network (OSTI)

A method was developed to create a nonlinear density gradient in a tank of water. Such gradients are useful for studying internal waves, an ocean phenomenon that plays an important role in climate and ocean circulation. ...

Harris, Victoria Siân

2007-01-01T23:59:59.000Z

70

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

71

Electron-cyclotron wave scattering by edge density fluctuations in ITER Christos Tsironis,1,2  

E-Print Network (OSTI)

influence on localized heating and current drive. A wave used for electron-cyclotron current drive ECCD must. doi:10.1063/1.3264105 I. INTRODUCTION In the electron-cyclotron resonance heating ECRH sys- temElectron-cyclotron wave scattering by edge density fluctuations in ITER Christos Tsironis,1

Isliker, Heinz

72

High power density test of PXIE MEBT absorber prototype  

E-Print Network (OSTI)

One of the goals of the PXIE program at Fermilab is to demonstrate the capability to form an arbitrary bunch pattern from an initially CW 162.5 MHz H- bunch train coming out of an RFQ. The bunch-by-bunch selection will take place in the 2.1 MeV Medium Energy Beam Transport (MEBT) by directing the undesired bunches onto an absorber that needs to withstand a beam power of up to 21 kW, focused onto a spot with a ~2 mm rms radius. Two prototypes of the absorber were manufactured from molybdenum alloy TZM and tested with a 28 keV DC electron beam up to the peak surface power density required for PXIE, 17W/mm2. Temperatures and flow parameters were measured and compared to analysis. This paper describes the absorber prototypes and key testing results.

Shemyakin, A

2015-01-01T23:59:59.000Z

73

An Improved Method for Estimating the Wind Power Density Distribution Function  

Science Journals Connector (OSTI)

The wind power density (WPD) distribution curve is essential for wind power assessment and wind turbine engineering. The usual practice of estimating this curve from wind speed data is to first estimate the wind speed probability density function ...

Mark L. Morrissey; Werner E. Cook; J. Scott Greene

2010-07-01T23:59:59.000Z

74

High power density AEM combustion for TPV applications  

Science Journals Connector (OSTI)

Various emitter designs and compositions are investigated to improve the performance and reduce the cost of thermophotovoltaic (TPV) devices. In order to maximize the overall system efficiency of combustion-powered TPV devices it is desirable to design an emitter system that will provide a high and uniform volumetric heat release producing a high intensity and uniform in-band photons flux thus enabling reduced size and weight of TPV generators. Quantum Group Inc. (QGI) has developed a high power density radiant burner/emitter technology which we have called Advanced Emissive Matrix (AEM). The AEM system is applicable to broad-band and narrow-band TPV approaches. Several AEM combustors-both broad-band and narrow-band-have been built tested and have consistently demonstrated extremely high power density (up to 30 W/cm3). Radiant emissions greater than 27 W/cm2 were measured from an AEM combustor fired with natural gas at 15% excess air. This level of radiant heat flux enables the utilization of concentrator-type PV cells which is a method of reducing cost size and weight of TPV devices. Additionally it was found that the AEM structure could be engineered to provide a desired radiant emission profile. The influence of the primary combustion parameters on emitter performance will also be presented. Therefore integration of the narrow-band emitter materials into an AEM combustor results in the delivery of high intensity selective and uniform photons to the PV cell face that improves TPV device performance.

Aleksandr S. Kushch; Steven M. Skinner

1999-01-01T23:59:59.000Z

75

A low-power wave union TDC implemented in FPGA  

SciTech Connect

A low-power time-to-digital convertor (TDC) for an application inside a vacuum has been implemented based on the Wave Union TDC scheme in a low-cost field programmable gate array (FPGA) device. Bench top tests have shown that a time measurement resolution better than 30 ps (standard deviation of time differences between two channels) is achieved. Special firmware design practices are taken to reduce power consumption. The measurements indicate that with 32 channels fitting in the FPGA device, the power consumption on the FPGA core voltage is approximately 9.3 mW/channel and the total power consumption including both core and I/O banks is less than 27 mW/channel.

Wu, Jinyuan; /Fermilab; Shi, Yanchen; Zhu, Douglas; /Illinois Math. Sci. Acad.

2011-10-01T23:59:59.000Z

76

On the Energy-Momentum Density of Gravitational Plane Waves  

E-Print Network (OSTI)

By embedding Einstein's original formulation of GR into a broader context we show that a dynamic covariant description of gravitational stress-energy emerges naturally from a variational principle. A tensor $T^G$ is constructed from a contraction of the Bel tensor with a symmetric covariant second degree tensor field $\\Phi$ and has a form analogous to the stress-energy tensor of the Maxwell field in an arbitrary space-time. For plane-fronted gravitational waves helicity-2 polarised (graviton) states can be identified carrying non-zero energy and momentum.

T. Dereli; R. W. Tucker

2004-01-20T23:59:59.000Z

77

Constraining the gravitational wave energy density of the Universe using Earth's ring  

E-Print Network (OSTI)

The search for gravitational waves is one of today's major scientific endeavors. A gravitational wave can interact with matter by exciting vibrations of elastic bodies. Earth itself is a large elastic body whose so-called normal-mode oscillations ring up when a gravitational wave passes. Therefore, precise measurement of vibration amplitudes can be used to search for the elusive gravitational-wave signals. Earth's free oscillations that can be observed after high-magnitude earthquakes have been studied extensively with gravimeters and low-frequency seismometers over many decades leading to invaluable insight into Earth's structure. Making use of our detailed understanding of Earth's normal modes, numerical models are employed for the first time to accurately calculate Earth's gravitational-wave response, and thereby turn a network of sensors that so far has served to improve our understanding of Earth, into an astrophysical observatory exploring our Universe. In this article, we constrain the energy density of gravitational waves to values in the range 0.035 - 0.15 normalized by the critical energy density of the Universe at frequencies between 0.3mHz and 5mHz, using 10 years of data from the gravimeter network of the Global Geodynamics Project that continuously monitors Earth's oscillations. This work is the first step towards a systematic investigation of the sensitivity of gravimeter networks to gravitational waves. Further advance in gravimeter technology could improve sensitivity of these networks and possibly lead to gravitational-wave detection.

Michael Coughlin; Jan Harms

2014-06-04T23:59:59.000Z

78

Heat-and-Run: Leveraging SMT and CMP to Manage Power Density Through the Operating System  

E-Print Network (OSTI)

Heat-and-Run: Leveraging SMT and CMP to Manage Power Density Through the Operating System Mohamed and thermal ability of packages to dissipate heat. Power den- sity is characterized by localized chip hot Performance, Reliability Keywords Power density, heat, CMP, SMT, migration 1 INTRODUCTION Power

Vijaykumar, T. N.

79

Dispersion relation and Landau damping of waves in high-energy density plasmas  

Science Journals Connector (OSTI)

We present a theoretical investigation on the propagation of electromagnetic waves and electron plasma waves in high energy density plasmas using the covariant Wigner function approach. Based on the covariant Wigner function and Dirac equation, a relativistic quantum kinetic model is established to describe the physical processes in high-energy density plasmas. With the zero-temperature Fermi–Dirac distribution, the dispersion relation and Landau damping of waves containing the relativistic quantum corrected terms are derived. The relativistic quantum corrections to the dispersion relation and Landau damping are analyzed by comparing our results with those obtained in classical and non-relativistic quantum plasmas. We provide a detailed discussion on the Landau damping obtained in classical plasmas, non-relativistic Fermi plasmas and relativistic Fermi plasmas. The contributions of the Bohm potential, the Fermi statistics pressure and relativistic effects to the dispersion relation and Landau damping of waves are quantitatively calculated with real plasma parameters.

Jun Zhu; Peiyong Ji

2012-01-01T23:59:59.000Z

80

KRONOSEISMOLOGY: USING DENSITY WAVES IN SATURN'S C RING TO PROBE THE PLANET'S INTERIOR  

SciTech Connect

Saturn's C ring contains multiple spiral patterns that appear to be density waves driven by periodic gravitational perturbations. In other parts of Saturn's rings, such waves are generated by Lindblad resonances with Saturn's various moons, but most of the wave-like C-ring features are not situated near any strong resonance with any known moon. Using stellar occultation data obtained by the Visual and Infrared Mapping Spectrometer on board the Cassini spacecraft, we investigate the origin of six unidentified C-ring waves located between 80,900 and 87,200 km from Saturn's center. By measuring differences in the waves' phases among the different occultations, we are able to determine both the number of arms in each spiral pattern and the speeds at which these patterns rotate around the planet. We find that all six of these waves have between two and four arms and pattern speeds between 1660 Degree-Sign day{sup -1} and 1861 Degree-Sign day{sup -1}. These speeds are too large to be attributed to any satellite resonance. Instead, they are comparable to the predicted pattern speeds of waves generated by low-order normal-mode oscillations within the planet. The precise pattern speeds associated with these waves should therefore provide strong constraints on Saturn's internal structure. Furthermore, we identify multiple waves with the same number of arms and very similar pattern speeds, indicating that multiple m = 3 and m = 2 sectoral (l = m) modes may exist within the planet.

Hedman, M. M.; Nicholson, P. D., E-mail: mmhedman@astro.cornell.edu [Center for Radiophysics and Space Research, Cornell University, Ithaca, NY 14850 (United States)

2013-07-01T23:59:59.000Z

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


81

Constraining the gravitational wave energy density of the Universe using Earth's ring  

E-Print Network (OSTI)

The search for gravitational waves is one of today's major scientific endeavors. A gravitational wave can interact with matter by exciting vibrations of elastic bodies. Earth itself is a large elastic body whose so-called normal-mode oscillations ring up when a gravitational wave passes. Therefore, precise measurement of vibration amplitudes can be used to search for the elusive gravitational-wave signals. Earth's free oscillations that can be observed after high-magnitude earthquakes have been studied extensively with gravimeters and low-frequency seismometers over many decades leading to invaluable insight into Earth's structure. Making use of our detailed understanding of Earth's normal modes, numerical models are employed for the first time to accurately calculate Earth's gravitational-wave response, and thereby turn a network of sensors that so far has served to improve our understanding of Earth, into an astrophysical observatory exploring our Universe. In this article, we constrain the energy density o...

Coughlin, Michael

2014-01-01T23:59:59.000Z

82

Interplay of superconductivity, magnetism, and density waves in rare-earth tritellurides and iron-based superconducting materials  

E-Print Network (OSTI)

3. Magnetism in Metals . . . . . . . . . . . . . . . . .IV Superconductivity and Magnetism in Iron-PnictideIII Superconductivity, Magnetism and Charge-Density Waves in

Zocco, Diego Andrés

2011-01-01T23:59:59.000Z

83

An Exact Calculation of the Energy Density of Cosmological Gravitational Waves  

E-Print Network (OSTI)

In this paper we calculate the Bogoliubov coefficients and the energy density of the stochastic gravitational wave background for a universe that undergoes inflation followed by radiation domination and matter domination, using a formalism that gives the Bogoliubov coefficients as continous functions of time. By making a reasonable assumption for the equation of state during reheating, we obtain in a natural way the expected high frequency cutoff in the spectral energy density.

L. E. Mendes; A. B. Henriques; R. G. Moorhouse

1994-10-24T23:59:59.000Z

84

Near?Millimeter Wave Issues for a Space Power Grid  

Science Journals Connector (OSTI)

This paper reports continuing work on an evolutionary revenue?generating approach to Space Solar Power. The 220 GHz atmospheric transmission window is chosen leaving open the option of using millimeter wave or laser wavelengths. The progression from frequency to system business case is laid out seeking the performance figures needed for a self?sustaining system and to open up Space Solar Power in 15 to 17 years from first launch. An overall transmission efficiency in excess of 30 percent is required from DC to beamed power and back to DC or high?voltage AC to meet a delivered free?market price target of 30 cents per KWH or 20 percent if a price of 45 cents per KWH. Climate data show that rain obscuration is a non?issue for many of the renewable?power sites that comprise the market. The technology of direct solar conversion to DC and to beamed power would satisfy the needed efficiencies but requires advances in nano?scale fabrication with dielectrics.

Narayanan Komerath; Vigneshwar Venkat; Jason Fernandez

2009-01-01T23:59:59.000Z

85

High-Power Thermoelectrically-Cooled and Uncooled Mid-Wave Infrared Quantum Cascade Lasers  

Science Journals Connector (OSTI)

We present high performance thermoelectrically-cooled and uncooled mid-wave infrared (?=4.6 ?m) quantum cascade lasers with continuous-wave output power of 2.9 W and 1 W at room...

Maulini, Richard; Lyakh, Arkadiy; Tsekoun, Alexei; Pflugl, Christian; Diehl, Laurent; Capasso, Federico; Patel, Kumar

86

The characteristics of atmospheric radio frequency discharges with frequency increasing at a constant power density  

SciTech Connect

A computational model is used to investigate the characteristics of atmospheric radio frequency discharges by increasing frequency from 20 to 100 MHz at a constant power density. The simulation results show that increasing frequency can effectively enhance electron density before the transition frequency but after it the ignition is quenched then the electron density decreases. However this simulation also indicates the maximum time-averaged electron energy reduces monotonically with the excitation frequency increasing at a constant power density.

Zhang Yuantao; Li Qingquan; Lou Jie; Li Qingmin [School of Electrical Engineering, Shandong University, Jinan, Shandong Province 250061 (China)

2010-10-04T23:59:59.000Z

87

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.,

88

Wind: wind power density maps at 50m above ground and 1km resolution...  

Open Energy Info (EERE)

maps ... Dataset Activity Stream Wind: wind power density maps at 50m above ground and 1km resolution for Ghana from NREL (Abstract):HTMLREMOVEDHTMLREMOVEDRaster GIS data, 50...

89

Wind: wind power density maps at 50m above ground and 1km resolution...  

Open Energy Info (EERE)

resolution for Central America from NREL (Abstract):HTMLREMOVEDHTMLREMOVED50 m wind power density (Wm2) maps of Central America. (Purpose):HTMLREMOVEDHTMLREMOVEDTo...

90

Wind: wind power density maps at 50 m above ground and 1km resolution...  

Open Energy Info (EERE)

maps ... Dataset Activity Stream Wind: wind power density maps at 50 m above ground and 1km resolution for Cuba from NREL (Abstract):HTMLREMOVEDHTMLREMOVEDRaster GIS data, 50...

91

A New Mechanism of Charge Density Wave Discovered in Transition Metal  

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

8 8 A New Mechanism of Charge Density Wave Discovered in Transition Metal Dichalcogenides Charge density waves (CDW) are a type of coupled electronic-lattice instability found in quasi-low dimensional materials. The driving force behind the instability is the reduction in energy of electrons in the material as a consequence of establishing a spontaneous periodic modulation of the crystalline lattice with an appropriate wave vector. The symmetry of the CDW state is very sensitive to the electronic structure of the host material. Charge density wave has been observed in quasi-one dimensional compounds, high temperature superconductors, manganites and many others.1-4 Conventionally, Fermi surface nesting is the dominant and textbook mechanism for CDW. However, it fails to explain the CDW in the 2H-structured transition metal dichalcogenides (2H-TMD's), which is actually the first two-dimensional CDW materials discovered in 1975.5 Even after three decades of intensive research on this subject, the CDW mechanism of 2H-TMD's remain mysterious and controversial.

92

High-density thermoelectric power generation and nanoscale thermal metrology  

E-Print Network (OSTI)

Thermoelectric power generation has been around for over 50 years but has seen very little large scale implementation due to the inherently low efficiencies and powers available from known materials. Recent material advances ...

Mayer, Peter (Peter Matthew), 1978-

2007-01-01T23:59:59.000Z

93

OXIDATION OF DRY HYDROCARBONS AT HIGH-POWER DENSITY ANODES  

SciTech Connect

This work builds upon discoveries by the University of Pennsylvania and others pertaining to the oxidation of dry hydrocarbon fuels in high temperature solid oxide fuel cells. The work reported here was restricted primarily to dry methane and confirms that YSZ-based cells, having ceria in the anode as a catalyst and copper in the anode as a current collector, can operate on dry methane for extended periods. Thirty-three lab-scale cells of various designs were fabricated and operated under a variety of conditions. The longest-lived cell gave stable performance on dry methane at 800 C for over 305 hours. Only slight carbon deposition was noted at the completion of the test. A corresponding nickel/YSZ-based anode would have lasted for less than an hour under these test conditions (which included open circuit potential measurements) before carbon fouling essentially destroyed the cell. The best performing cell achieved 112 mW/cm{sub 2} on dry methane at 800 C. Several problems were encountered with carbon fouling and declining open circuit voltages in many of the test cells after switching from operation on hydrogen to dry methane. Although not rigorously confirmed by experimentation, the results suggested that air infiltration through less than perfect perimeter seals or pinholes in the electrolytes, or both gave rise to conditions that caused the carbon fouling and OCV decline. Small amounts of air reacting with methane in a partial oxidation reaction could produce carbon monoxide that, in turn, would deposit the carbon. If this mechanism is confirmed, it implies that near perfect hardware is required for extended operation. Some evidence was also found for the formation of electrical shorts, probably from carbon deposits bridging the electrolyte. Work with odorized methane and with methane containing 100-ppm hydrogen sulfide confirmed that copper is stable at 800 C in dry hydrocarbon fuels in the presence of sulfur. In a number of cases, but not exclusively, the performance life on dry methane with sulfur compounds was much longer than with dry methane alone. The effect of sulfur compounds in these cases appeared to correlate with inhibition of carbon deposition. Mixed results were obtained for the effect of the sulfur compounds on power density. Progress also was made in understanding the mechanisms involved in direct utilization of dry natural gas. Evidence was developed for three possible mechanisms for dry methane utilization in addition to the usually cited mechanism--direct oxidation of methane by oxygen anions. Further work is required at a fundamental level before the knowledge gained here can be translated into higher levels of performance.

K.Krist; O. Spaldon-Stewart; R. Remick

2004-03-01T23:59:59.000Z

94

Fermi-liquid interactions and the superfluid density in d-wave superconductors  

Science Journals Connector (OSTI)

We construct a phenomenological superfluid Fermi-liquid-theory for a two-dimensional d-wave superconductor on a square lattice, and study the effect of quasiparticle interactions on the superfluid density. Using simple models for the dispersion and the Landau interaction function, we illustrate the deviation of these results from those for the isotropic superfluid. This allows us to reconcile the value and doping dependence of the superfluid density slope at low temperature obtained from penetration depth measurements, with photoemission data on nodal quasiparticles.

Arun Paramekanti and Mohit Randeria

2002-12-20T23:59:59.000Z

95

Optical investigation of the charge-density-wave phase transitions in NbSe3  

Science Journals Connector (OSTI)

We have measured the optical reflectivity R(?) of the quasi-one-dimensional conductor NbSe3 from the far infrared up to the ultraviolet between 10 and 300 K using light polarized along and normal to the chain axis. We find a depletion of the optical conductivity with decreasing temperature for both polarizations in the mid- to far-infrared region. This leads to a redistribution of spectral weight from low to high energies due to partial gapping of the Fermi surface below the charge-density-wave transitions at 145 K and 59 K. We deduce the bulk magnitudes of the charge-density wave gaps and discuss the scattering of ungapped free charge carriers and the role of fluctuation effects.

A. Perucchi; L. Degiorgi; R. E. Thorne

2004-05-28T23:59:59.000Z

96

Effect of a nonlinear power take off on a wave energy converter   

E-Print Network (OSTI)

This thesis is titled The influence of a nonlinear Power Take Off on a Wave Energy Converter. It looks at the effect that having a nonlinear Power Take Off (PTO) has on an inertial referenced, slack moored, point absorber, ...

Bailey, Helen Louise

2011-11-22T23:59:59.000Z

97

Experimental Investigation on Density Wave Instability of Sodium Boiling Two-Phase Flow in an Annulus  

SciTech Connect

Experiments of density wave instability in a liquid sodium boiling two-phase flow experiments in an annulus were carried out in the following parameters range: heat flux from 80 kW/m{sup 2} to 976 kW/m{sup 2}, inlet subcooling from 25.6 deg. C to 226.8 deg. C, mass flow rate from 7.92 kg/h to 68.9 kg/h, system pressure from 2600 Pa to 0.12 Mpa. Not only the mechanism of the instability, critical conditions and oscillation period, but also the effects of pressure, mass flow rate and inlet subcooling on the density wave instability were explored experimentally and theoretically. From the experimental data, it was found that the lower the inlet temperature was, the higher the system pressure and the mass flow rate that could result in a more stable boiling two-phase flow were. A correlation for the density wave instability was obtained on from the dimensional analysis for the conservation equations of mass, momentum and energy. (authors)

Suizheng Qiu; Dounan Jia [Xi'an Jiaotong University, No.28, Xianning West Road, Xi'an, Shaanxi, 710049 (China); Minoru Takahashi [Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152 (Japan)

2002-07-01T23:59:59.000Z

98

High power continuous-wave titanium:sapphire laser  

DOE Patents (OSTI)

A high-power continuous-wave laser resonator is provided, wherein first, second, third, fourth, fifth and sixth mirrors form a double-Z optical cavity. A first Ti:sapphire rod is disposed between the second and third mirrors and at the mid-point of the length of the optical cavity, and a second Ti:sapphire rod is disposed between the fourth and fifth mirrors at a quarter-length point in the optical cavity. Each Ti:sapphire rod is pumped by two counter-propagating pump beams from a pair of argon-ion lasers. For narrow band operation, a 3-plate birefringent filter and an etalon are disposed in the optical cavity so that the spectral output of the laser consists of 5 adjacent cavity modes. For increased power, seventy and eighth mirrors are disposed between the first and second mirrors to form a triple-Z optical cavity. A third Ti:sapphire rod is disposed between the seventh and eighth mirrors at the other quarter-length point in the optical cavity, and is pumped by two counter-propagating pump beams from a third pair of argon-ion lasers. 5 figures.

Erbert, G.V.; Bass, I.L.; Hackel, R.P.; Jenkins, S.L.; Kanz, V.K.; Paisner, J.A.

1993-09-21T23:59:59.000Z

99

Investigating the impact of wave energy in the electric power system - A case study of southern Sweden.  

E-Print Network (OSTI)

??The aim of this thesis has been to investigate the impact of wave energy in the electric power system of southern Sweden. How does wave… (more)

von Sydow, Tyra

2014-01-01T23:59:59.000Z

100

High-power parametric conversion from near-infrared to short-wave infrared  

E-Print Network (OSTI)

High-power parametric conversion from near-infrared to short-wave infrared Adrien Billat,1,* Steevy.billat@epfl.ch Abstract: We report the design of an all-fiber continuous wave Short-Wave Infrared source capable to output.4370) Nonlinear optics, fibers; (140.3070) Infrared and far-infrared lasers. References and links 1. M. N

Dalang, Robert C.

Note: This page contains sample records for the topic "wave power density" 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

Coupled-Oscillator Arrays for Millimeter-Wave Power-Combining and Mode-Locking  

E-Print Network (OSTI)

. 1. INTRODUCTION Obtaining useful levels of power from solid-state millimeter- wave systems trains of high-energy pulses. This new operation is based on a mode- locking technique similarIF1 P-1 Coupled-Oscillator Arrays for Millimeter-Wave Power-Combining and Mode-Locking Robert A

York, Robert A.

102

Reaction force control implementation of a linear generator in irregular waves for a wave power system.  

E-Print Network (OSTI)

??Most designs for wave energy converters include a hydraulic (or pneumatic) interface between the wave device and the generator to smooth electricity production, but a… (more)

Li, Bin

2012-01-01T23:59:59.000Z

103

A Framework to Determine the Probability Density Function for the Output Power of Wind Farms  

E-Print Network (OSTI)

A Framework to Determine the Probability Density Function for the Output Power of Wind Farms Sairaj to the power output of a wind farm while factoring in the availability of the wind turbines in the farm availability model for the wind turbines, we propose a method to determine the wind-farm power output pdf

Liberzon, Daniel

104

High Energy Density Utracapacitors: Low-Cost, High Energy and Power Density, Nanotube-Enhanced Ultracapacitors  

SciTech Connect

Broad Funding Opportunity Announcement Project: FastCAP is improving the performance of an ultracapacitor—a battery-like electronic device that can complement, and possibly even replace, an HEV or EV battery pack. Ultracapacitors have many advantages over conventional batteries, including long lifespans (over 1 million cycles, as compared to 10,000 for conventional batteries) and better durability. Ultracapacitors also charge more quickly than conventional batteries, and they release energy more quickly. However, ultracapacitors have fallen short of batteries in one key metric: energy density—high energy density means more energy storage. FastCAP is redesigning the ultracapacitor’s internal structure to increase its energy density. Ultracapacitors traditionally use electrodes made of irregularly shaped, porous carbon. FastCAP’s ultracapacitors are made of tiny, aligned carbon nanotubes. The nanotubes provide a regular path for ions moving in and out of the ultracapacitor’s electrode, increasing the overall efficiency and energy density of the device.

None

2010-04-01T23:59:59.000Z

105

MHK Technologies/IVEC Floating Wave Power Plant | Open Energy Information  

Open Energy Info (EERE)

IVEC Floating Wave Power Plant IVEC Floating Wave Power Plant < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage IVEC Floating Wave Power Plant.jpg Technology Profile Primary Organization Ivec Pty Ltd Technology Resource Click here Wave Technology Readiness Level Click here TRL 7 8 Open Water System Testing Demonstration and Operation Technology Description FWP design is based on an array of linked OWC s or chambers Similar to the cylinders of a combustion engine each FWP chamber has inlet low pressure flaps valves and outlet high pressure flaps valves As a wave passes through the FWP the water level and thus the air pressure within each chamber oscillates depending on its position within the wave cycle Mooring Configuration single point

106

MHK Technologies/Ocean Wave Power Spar Buoy Engine | Open Energy  

Open Energy Info (EERE)

Spar Buoy Engine Spar Buoy Engine < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Ocean Wave Power Spar Buoy Engine.jpg Technology Profile Primary Organization Functional Design Engineering Inc Technology Resource Click here Wave Technology Type Click here Point Absorber - Submerged Technology Readiness Level Click here TRL 4 Proof of Concept Technology Description A long period spar buoy supports a subsurface flow augmentor The augmentor directs water from the wave s submarine flow field to a free prime mover piston The prime mover is decoupled from the machine s PTO during times in the wave s cycle when there is little power available for conversion Wave energy is stored in the device until the is enough flow magnetude that power take off can efficiently take place Power can be taken off as high pressure water crankshaft torque or directly as DC electricity

107

Instability and Charge Density Wave of Metallic Quantum Chains on a Silicon Surface  

SciTech Connect

Self-assembled indium linear chains on the Si(111) surface are found to exhibit instability of the metallic phase and 1D charge density wave (CDW). The room-temperature metallic phase of these chains undergoes a temperature-induced, reversible transition into a semiconducting phase. The 1D CDW along the chains is observed directly in real space by scanning tunneling microscopy at low temperature. The Fermi contours of the metallic phase measured by angle-resolved photoemission exhibit a perfect nesting predicting precisely the CDW periodicity.

Takeda, S.; Rotenberg, E.; Matsuda, I.; Horikoshi, K.; Schà ƒ  ƒ à ‚  ¤fer, J.; Lee, C. M.; Kevan, S. D.; Ohta, T.; Nagao, T.

1999-06-14T23:59:59.000Z

108

Density profile in shock wave fronts of partially ionized xenon plasmas  

Science Journals Connector (OSTI)

Results for the reflection coefficient of shock-compressed dense xenon plasmas at pressures of 1.6–20 GPa and temperatures around 30 000 K are interpreted. In addition to former experiments using laser beams with ? = 1.06 µm, measurements at ? = 0.694 µm have been performed recently. Reflectivities typical for metallic systems are found at high densities. Besides free carriers, the theoretical description also takes into account the influence of the neutral component of the plasma on the reflectivity. A consistent description of the measured reflectivities is achieved only if a finite width of the shock wave front is considered.

H Reinholz; G Röpke; I Morozov; V Mintsev; Yu Zaparoghets; V Fortov; A Wierling

2003-01-01T23:59:59.000Z

109

Assessment of Projected Life-Cycle Costs for Wave, Tidal, Ocean Current, and In-Stream Hydrokinetic Power  

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

Assessment of Projected Life-Cycle Costs for Wave, Tidal, Ocean Current, and In-Stream Hydrokinetic Power

110

Evaluation of high power density annular fuel application in the Korean OPR-1000 reactor  

E-Print Network (OSTI)

Compared to the traditional solid fuel geometry for PWRs, the internally and externally cooled annular fuel offers the potential to increase the core power density while maintaining or increasing safety margins. It is ...

Zhang, Liang, Ph. D.. Massachusetts Institute of Technology

2009-01-01T23:59:59.000Z

111

Wind: wind speed and wind power density maps at 10m and 50m above...  

Open Energy Info (EERE)

files of wind speed and wind power density at 10 and 50 m heights. Global data of offshore wind resource as generated by NASA's QuikSCAT SeaWinds scatterometer....

112

Wind: wind speed and wind power density GIS data at 10m and 50m...  

Open Energy Info (EERE)

files of wind speed and wind power density at 10 and 50 m heights. Global data of offshore wind resource as generated by NASA's QuikScat SeaWinds scatterometer....

113

Assessment of helical-cruciform fuel rods for high power density LWRs  

E-Print Network (OSTI)

In order to significantly increase the power density of Light Water Reactors (LWRs), the helical-cruciform (HC) fuel rod assembly has been proposed as an alternative to traditional fuel geometry. The HC assembly is a ...

Conboy, Thomas M

2010-01-01T23:59:59.000Z

114

High Energy Density Sate, Material and Device with High Power Lasers  

Science Journals Connector (OSTI)

High energy density states with photon pressures of more than Tera bar and thermal pressure of more than Mega bar, is now available with high power lasers. Here I present creation of...

Kodama, R

115

X-ray power density spectra of black hole binaries : a new deadtime model for the RXTE PCA  

E-Print Network (OSTI)

The power density spectrum is an essential tool for determining the frequency content of X-ray radiation from astronomical sources. For neutron star systems, power density spectra reveal coherent oscillations for those ...

Wei, Dennis

2006-01-01T23:59:59.000Z

116

Electron Trapping in Shear Alfvén Waves that Power the Aurora  

Science Journals Connector (OSTI)

Results from 1D Vlasov drift-kinetic plasma simulations reveal how and where auroral electrons are accelerated along Earth’s geomagnetic field. In the warm plasma sheet, electrons become trapped in shear Alfvén waves, preventing immediate wave damping. As waves move to regions with larger vTe/vA, their parallel electric field decreases, and the trapped electrons escape their influence. The resulting electron distribution functions compare favorably with in situ observations, demonstrating for the first time a self-consistent link between Alfvén waves and electrons that form aurora.

Clare E. J. Watt and Robert Rankin

2009-01-26T23:59:59.000Z

117

Electron Trapping in Shear Alfven Waves that Power the Aurora  

SciTech Connect

Results from 1D Vlasov drift-kinetic plasma simulations reveal how and where auroral electrons are accelerated along Earth's geomagnetic field. In the warm plasma sheet, electrons become trapped in shear Alfven waves, preventing immediate wave damping. As waves move to regions with larger v{sub Te}/v{sub A}, their parallel electric field decreases, and the trapped electrons escape their influence. The resulting electron distribution functions compare favorably with in situ observations, demonstrating for the first time a self-consistent link between Alfven waves and electrons that form aurora.

Watt, Clare E. J.; Rankin, Robert [University of Alberta, Edmonton, Alberta (Canada)

2009-01-30T23:59:59.000Z

118

Making Wave Power Efficient and Affordable | Department of Energy  

Energy Savers (EERE)

is currently testing its Cycloidal Wave Energy Converter design at the Texas A&M Offshore Technology Research Center in College Station, Texas. The company hopes to...

119

Bragg scattering and wave-power extraction by an array of small buoys  

Science Journals Connector (OSTI)

...studies have been devoted to the potential of power extraction from sea waves by an isolated...Mei et al. 2005; Cruz 2008). To achieve power output comparable to a conventional power plant or a wind-turbine farm, a large array of absorbing...

2010-01-01T23:59:59.000Z

120

Predictive Power Control of Doubly-Fed Induction Generator for Wave Energy Converters  

E-Print Network (OSTI)

the Doubly- fed induction generator (DFIG). This paper deals then with a model-based predictive power control of a DFIG-based Wave Energy Converter (WEC). In the proposed control approach, the predicted output power was calculated using a DFIG linearized state-space model. The DFIG-based WEC power tracking performances further

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "wave power density" 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

Practical limits to the power that can be captured from ocean waves by oscillating bodies  

Science Journals Connector (OSTI)

Abstract The maximum average power that can be captured from ocean waves by an idealised and unconstrained oscillating body depends on two hydrodynamic properties: the wave radiation pattern and the radiation resistance (also called added damping or wave damping coefficient). These properties depend on the body geometry and the mode of oscillation. For such unconstrained motion the limits of absorbed power are well described. Power bounds due to physical restrictions like limited volume stroke or machinery stroke length has also received some attention, but has not been sufficiently explored. This paper looks at such physical bounds to the achievable absorbed power. It is done by physical reasoning leading to analytical expressions for the upper bounds, treating heave, surge and pitch motions separately. It is shown how size, oscillation mode and volume stroke of the oscillating body inherently influence the absorption ability. Furthermore, implications for the practical and economical design of wave energy are identified and discussed.

Jørgen Hals Todalshaug

2013-01-01T23:59:59.000Z

122

A power analysis and data acquisition system for ocean wave energy device testing  

Science Journals Connector (OSTI)

In the testing of ocean wave energy devices, the demand for a portable and robust data acquisition and electrical loading system has become apparent. This paper investigates the development of a 30 kW inclusive system combining loading capabilities, real-time power analysis, and data acquisition for the testing of deployed ocean wave energy devices. Hardware results for ocean testing are included.

Ean Amon; Ted K.A. Brekken; Annette von Jouanne

2011-01-01T23:59:59.000Z

123

Generation of Alfven waves by high power pulse at the electron plasma frequency  

E-Print Network (OSTI)

Generation of Alfve´n waves by high power pulse at the electron plasma frequency B. Van CompernolleG, Helium) capable of supporting Alfve´n waves has been studied. The interaction leads to the generation locations. Citation: Van Compernolle, B., W. Gekelman, P. Pribyl, and T. A. Carter (2005), Generation

California at Los Angles, University of

124

Direct measurement of density oscillation induced by a radio-frequency wave  

SciTech Connect

An O-mode reflectometer at a frequency of 25.85 GHz was applied to plasmas heated by the high harmonic fast wave (21 MHz) in the TST-2 spherical tokamak. An oscillation in the phase of the reflected microwave in the rf range was observed directly for the first time. In TST-2, the rf (250 kW) induced density oscillation depends mainly on the poloidal rf electric field, which is estimated to be about 0.2 kV/m rms by the reflectometer measurement. Sideband peaks separated in frequency by ion cyclotron harmonics from 21 MHz, and peaks at ion cyclotron harmonics which are suggested to be quasimodes generated by parametric decay, were detected.

Yamada, T.; Ejiri, A.; Shimada, Y.; Oosako, T.; Tsujimura, J.; Takase, Y.; Kasahara, H. [Research Institute for Applied Mechanics, Kyushu University, Kasuga 816-8580 (Japan); Graduate School of Frontier Sciences, University of Tokyo, Kashiwa 277-8561 (Japan); National Institute for Fusion Science, Toki 509-5292 (Japan)

2007-08-15T23:59:59.000Z

125

Electronic structure of two-dimensional hexagonal diselenides: Charge density waves and pseudogap behavior  

SciTech Connect

We theoretically study the electronic structure (spectral functions and Fermi surfaces) of incommensurate pseudogap and charge density wave (CDW) and commensurate CDW phases of quasi-two-dimensional diselenides 2H-TaSe{sub 2} and 2H-NbSe{sub 2}. The incommensurate pseudogap regime is described within the scenario based on short-range-order CDW fluctuations, considered within the static Gaussian random field model. In contrast, e.g., to high-T{sub c} cuprates, layered dichalcogenides have several different CDW scattering vectors and an electronic spectrum with two bands at the Fermi level. For this, we present a theoretical background for the description of multiple scattering processes within a multiple-band electronic spectrum. Theoretical spectral functions and Fermi surfaces thus obtained are compared with recent ARPES experimental data, demonstrating rather good qualitative agreement.

Kuchinskii, E. Z., E-mail: kuchinsk@iep.uran.ru; Nekrasov, I. A., E-mail: nekrasov@iep.uran.ru; Sadovskii, M. V. [Russian Academy of Sciences, Institute for Electrophysics, Ural Branch (Russian Federation)

2012-04-15T23:59:59.000Z

126

A Predictive power control of Doubly Fed Induction Generator for Wave Energy Converter  

E-Print Network (OSTI)

using a linearized state- space model. The DFIG-based WEC power tracking performances further converter (WEC), irregular wave, doubly-fed induction generator (DFIG), predictive power control, I rotational motion for connection to a conventional rotating electrical generator as a DFIG (Fig. 1). Fig.1

Brest, Université de

127

Enthusiasm for UK wave power survives high costs  

Science Journals Connector (OSTI)

... drive a turbine. But other proposals include on site conversion to hydrogen, on site desalination or direct use of the mechanical power to make heat.

Joe Schwartz

1978-11-30T23:59:59.000Z

128

Non-power law behavior of the radial profile of phase-space density of halos  

SciTech Connect

We study the pseudo phase-space density, ?(r)/?{sup 3}(r), of ?CDM dark matter halos with and without baryons (baryons+DM, and pure DM), by using the model introduced in Del Popolo (2009), which takes into account the effect of dynamical friction, ordered and random angular momentum, baryons adiabatic contraction and dark matter baryons interplay. We examine the radial dependence of ?(r)/?{sup 3}(r) over 9 orders of magnitude in radius for structures on galactic and cluster of galaxies scales. We find that ?(r)/?{sup 3}(r) is approximately a power-law only in the range of halo radius resolved by current simulations (down to 0.1% of the virial radius) while it has a non-power law behavior below the quoted scale, with inner profiles changing with mass. The non-power-law behavior is more evident for halos constituted both of dark matter and baryons while halos constituted just of dark matter and with angular momentum chosen to reproduce a Navarro-Frenk-White (NFW) density profile, are characterized by an approximately power-law behavior. The results of the present paper lead to conclude that density profiles of the NFW type are compatible with a power-law behavior of ?(r)/?{sup 3}(r), while those flattening to the halo center, like those found in Del Popolo (2009) or the Einasto profile, or the Burkert profile, cannot produce radial profile of the pseudo-phase-space density that are power-laws at all radii. The results argue against universality of the pseudo phase-space density and as a consequence argue against universality of density profiles constituted by dark matter and baryons as also discussed in Del Popolo (2009)

Popolo, A. Del, E-mail: adelpopolo@oact.inaf.it [Dipartimento di Fisica e Astronomia, University Of Catania, Viale Andrea Doria 6, 95125 Catania (Italy)

2011-07-01T23:59:59.000Z

129

Low density, microcellular, dopable, agar/gelatin foams for pulsed power experiments  

SciTech Connect

Low-density, microcellular foams prepared from the natural polymers agar and gelatin have been developed for pulsed-power physics experiments. Numerous experiments were supported with foams having densities at or below 10 mg/cm{sup 3}. For some of the experiments, the agar/gelatin foam was uniformly doped with metallic elements using soluble salts. Depending on the method of preparation, cell sizes were typically below 10 microns and for one process were below 1.0 micron.

McNamara, W.F. [Orion International Technologies, Inc., Albuquerque, NM (United States); Aubert, J.H. [Sandia National Lab., Albuquerque, NM (United States)

1997-04-01T23:59:59.000Z

130

Power spectrum of electron number density perturbations at cosmological recombination epoch  

E-Print Network (OSTI)

The power spectrum of number density perturbations of free electrons is obtained for the epoch of cosmological recombination of hydrogen. It is shown that amplitude of the electron perturbations power spectrum of scales larger than acoustic horizon exceeds by factor of 17 the amplitude of baryon matter density ones (atoms and ions of hydrogen and helium). In the range of the first and second acoustic peaks such relation is 18, in the range of the third one 16. The dependence of such relations on cosmological parameters is analysed too.

B. Venhlovska; B. Novosyadlyj

2008-12-12T23:59:59.000Z

131

Control of offshore marine substation for grid-connection of a wave power farm  

Science Journals Connector (OSTI)

Abstract To grid-connect an offshore wave power farm, an intermediate marine substation is suggested. As a part of the Uppsala University wave power project, a marine substation has been designed, assembled and deployed at sea. The substation is capable of connecting up to seven wave energy converters (WECs), and to transfer the power to the onshore 1 kV-grid. In this article, the control procedure for grid connection of the \\{WECs\\} is described step-by-step, and the practical implementations are presented. The system is designed with autonomous control and will connect or disconnect the WECs, depending on the sea state. Fault handling is taken into account, and grid power quality such as harmonic distortion and flicker are considered in the design. Experimental results are presented to verify the system functionalities.

Rickard Ekström; Mats Leijon

2014-01-01T23:59:59.000Z

132

Stable relativistic/charge-displacement channels in ultrahigh power density (?1021 W/cm3) plasmas  

Science Journals Connector (OSTI)

...the contemporary production of vigorous thermonuclear environments, the achievable power density...acceleration, and the fast ignition of fusion targets. The key to the...Rhodes C K ( 1995 ) Plasma Phys Control Fusion 37 : 569 – 597 . 2 Borisov A B Borovskiy...

A. B. Borisov; J. W. Longworth; K. Boyer; C. K. Rhodes

1998-01-01T23:59:59.000Z

133

Stable relativistic/charge-displacement channels in ultrahigh power density (?1021 W/cm3) plasmas  

Science Journals Connector (OSTI)

...mankind with an origin that predates the Stone Age. From the use of a wooden club to the contemporary production of vigorous thermonuclear environments, the achievable power density (W/cm 3 ) has been advanced by approximately a factor of 20 orders of magnitude...

A. B. Borisov; J. W. Longworth; K. Boyer; C. K. Rhodes

1998-01-01T23:59:59.000Z

134

On the breaking of a plasma wave in a thermal plasma. I. The structure of the density singularity  

SciTech Connect

The structure of the singularity that is formed in a relativistically large amplitude plasma wave close to the wave breaking limit is found by using a simple waterbag electron distribution function. The electron density distribution in the breaking wave has a typical 'peakon' form. The maximum value of the electric field in a thermal breaking plasma is obtained and compared to the cold plasma limit. The results of computer simulations for different initial electron distribution functions are in agreement with the theoretical conclusions. The after-wavebreak regime is then examined, and a semi-analytical model of the density evolution is constructed. Finally the results of two dimensional particle in cell simulations for different initial electron distribution functions are compared, and the role of thermal effects in enhancing particle injection is noted.

Bulanov, Sergei V.; Esirkepov, Timur Zh.; Kando, Masaki; Koga, James K.; Pirozhkov, Alexander S.; Nakamura, Tatsufumi [QuBS, Japan Atomic Energy Agency, 1-8-7 Umemidai, Kizugawa, Kyoto 619-0215 (Japan); Bulanov, Stepan S. [University of California, Berkeley, California 94720 (United States); Schroeder, Carl B.; Esarey, Eric [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Califano, Francesco; Pegoraro, Francesco [Physics Department, University of Pisa, Pisa 56127 (Italy)

2012-11-15T23:59:59.000Z

135

High power water load for microwave and millimeter-wave radio frequency sources  

DOE Patents (OSTI)

A high power water load for microwave and millimeter wave radio frequency sources has a front wall including an input port for the application of RF power, a cylindrical dissipation cavity lined with a dissipating material having a thickness which varies with depth, and a rear wall including a rotating reflector for the reflection of wave energy inside the cylindrical cavity. The dissipation cavity includes a water jacket for removal of heat generated by the absorptive material coating the dissipation cavity, and this absorptive material has a thickness which is greater near the front wall than near the rear wall. Waves entering the cavity reflect from the rotating reflector, impinging and reflecting multiple times on the absorptive coating of the dissipation cavity, dissipating equal amounts of power on each internal reflection.

Ives, R. Lawrence (Saratoga, CA); Mizuhara, Yosuke M. (Palo Alto, CA); Schumacher, Richard V. (Sunnyvale, CA); Pendleton, Rand P. (Saratoga, CA)

1999-01-01T23:59:59.000Z

136

Estimated changes in wind speed and wind power density over the western High Plains, 1971–2000  

Science Journals Connector (OSTI)

This manuscript presents the results of research on the temporal patterns in wind speed and wind power density from 1971 to 2000. The ... Mountains in an area which has a proven wind power resource. Policies and ...

J. Scott Greene; Matthew Chatelain; Mark Morrissey…

2012-08-01T23:59:59.000Z

137

Estimation of Heavy Ion Densities From Linearly Polarized EMIC Waves At Earth  

SciTech Connect

Linearly polarized EMIC waves are expected to concentrate at the location where their wave frequency satisfies the ion-ion hybrid (IIH) resonance condition as the result of a mode conversion process. In this letter, we evaluate absorption coefficients at the IIH resonance in the Earth geosynchronous orbit for variable concentrations of helium and azimuthal and field-aligned wave numbers in dipole magnetic field. Although wave absorption occurs for a wide range of heavy ion concentration, it only occurs for a limited range of azimuthal and field-aligned wave numbers such that the IIH resonance frequency is close to, but not exactly the same as the crossover frequency. Our results suggest that, at L = 6.6, linearly polarized EMIC waves can be generated via mode conversion from the compressional waves near the crossover frequency. Consequently, the heavy ion concentration ratio can be estimated from observations of externally generated EMIC waves that have polarization.

Kim, Eun-Hwa; Johnson, Jay R.; Lee, Dong-Hun

2014-02-24T23:59:59.000Z

138

Inflation that runs naturally: Gravitational waves and suppression of power at large and small scales  

E-Print Network (OSTI)

We point out three correlated predictions of the axion monodromy inflation model: large amplitude of gravitational waves, suppression of power on horizon scales and on scales relevant for the formation of dwarf galaxies. While these predictions are likely generic to models with oscillations in the inflaton potential, the axion monodromy model naturally accommodates the required running spectral index through Planck-scale corrections to the inflaton potential. Applying this model to a combined data set of Planck, ACT, SPT, and WMAP low-$\\ell$ polarization cosmic microwave background (CMB) data, we find a best-fit tensor-to-scalar ratio $r_{0.05} = 0.07^{+0.05}_{-0.04}$ due to gravitational waves, which may have been observed by the BICEP2 experiment. Despite the contribution of gravitational waves, the total power on large scales (CMB power spectrum at low multipoles) is lower than the standard $\\Lambda$CDM cosmology with a power-law spectrum of initial perturbations and no gravitational waves, thus mitigating some of the tension on large scales. There is also a reduction in the matter power spectrum of 20-30\\% at scales corresponding to $k = 10~{\\rm Mpc}^{-1}$, which are relevant for dwarf galaxy formation. This will alleviate some of the unsolved small-scale structure problems in the standard $\\Lambda$CDM cosmology.

Quinn E. Minor; Manoj Kaplinghat

2014-11-03T23:59:59.000Z

139

Journal of Power Sources 153 (2006) 6875 Numerical study of a flat-tube high power density solid oxide fuel cell  

E-Print Network (OSTI)

power density (HPD) solid oxide fuel cell (SOFC) is a geometry based on a tubular type SOFC: Flat-tube; High power density (HPD); Solid oxide fuel cell (SOFC); Simulation; Performance; Optimization 1. Introduction A solid oxide fuel cell (SOFC), like any other fuel cell, produces electrical

140

Innovative Deepwater Platform Aims to Harness Offshore Wind and Wave Power  

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

Deepwater Platform Aims to Harness Offshore Wind and Deepwater Platform Aims to Harness Offshore Wind and Wave Power Innovative Deepwater Platform Aims to Harness Offshore Wind and Wave Power March 28, 2011 - 5:55pm Addthis An employee installs a smart meter as part of a smart grid initiative by EPB. The project is supporting 390 jobs in the Chattanooga area. | Photo courtesy of EPB An employee installs a smart meter as part of a smart grid initiative by EPB. The project is supporting 390 jobs in the Chattanooga area. | Photo courtesy of EPB Mark Higgins Operations Supervisor, Wind & Water Power Technologies Office Principle Power, Inc, of Seattle is using $1.4 million in funding from the Department of Energy's Office of Energy Efficiency and Renewable Energy to develop an innovative technology with the potential to generate electricity

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141

Wave-actuated power take-off device for electricity generation  

SciTech Connect

Since 2008, Resolute Marine Energy, Inc. (RME) has been engaged in the development of a rigidly moored shallow-water point absorber wave energy converter, the "3D-WEC". RME anticipated that the 3D-WEC configuration with a fully buoyant point absorber buoy coupled to three power take off (PTO) units by a tripod array of tethers would achieve higher power capture than a more conventional 1-D configuration with a single tether and PTO. The investigation conducted under this program and documented herein addressed the following principal research question regarding RME'Â?Â?s power take off (PTO) concept for its 3D-WEC: Is RME's winch-driven generator PTO concept, previously implemented at sub-scale and tested at the Ohmsett wave tank facility, scalable in a cost-effective manner to significant power levels Â?Â?e.g., 10 to 100kW?

Chertok, Allan

2013-01-31T23:59:59.000Z

142

Two-dimensional AXUV-based radiated power density diagnostics on NSTX-U  

SciTech Connect

A new set of radiated-power-density diagnostics for the National Spherical Torus Experiment Upgrade (NSTX-U) tokamak have been designed to measure the two-dimensional poloidal structure of the total photon emissivity profile in order to perform power balance, impurity transport, and magnetohydrodynamic studies. Multiple AXUV-diode based pinhole cameras will be installed in the same toroidal angle at various poloidal locations. The local emissivity will be obtained from several types of tomographic reconstructions. The layout and response expected for the new radially viewing poloidal arrays will be shown for different impurity concentrations to characterize the diagnostic sensitivity. The radiated power profile inverted from the array data will also be used for estimates of power losses during transitions from various divertor configurations in NSTX-U. The effect of in-out and top/bottom asymmetries in the core radiation from high-Z impurities will be addressed.

Faust, I.; Parker, R. R. [MIT - Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Delgado-Aparicio, L.; Bell, R. E.; Diallo, A.; Gerhardt, S. P.; LeBlanc, B.; Kozub, T. A. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States); Tritz, K. [The Johns Hopkins University, Baltimore, Maryland 21209 (United States); Stratton, B. C. [MIT - Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States)

2014-11-15T23:59:59.000Z

143

Power spectral density estimation for wireless fluctuation enhanced gas sensor nodes  

E-Print Network (OSTI)

Fluctuation enhanced sensing (FES) is a promising method to improve the selectivity and sensitivity of semiconductor and nanotechnology gas sensors. Most measurement setups include high cost signal conditioning and data acquisition units as well as intensive data processing. However, there are attempts to reduce the cost and energy consumption of the hardware and to find efficient processing methods for low cost wireless solutions. In our paper we propose highly efficient signal processing methods to analyze the power spectral density of fluctuations. These support the development of ultra-low-power intelligent fluctuation enhanced wireless sensor nodes while several further applications are also possible.

Mingesz, Robert; Gingl, Zoltan

2014-01-01T23:59:59.000Z

144

High excitation power photoluminescence studies of ultra-low density GaAs quantum dots  

SciTech Connect

We fabricate GaAs epitaxial quantum dots (QDs) by filling of self-organized nanoholes in AlGaAs. The QDs are fabricated under optimized process conditions and have ultra-low density in the 10{sup 6} cm{sup ?2} regime. At low excitation power the optical emission of single QDs exhibit sharp excitonic lines, which are attributed to the recombination of excitonic and biexcitonic states. High excitation power measurements reveal surprisingly broad emission lines from at least six QD shell states.

Sonnenberg, D.; Graf, A.; Paulava, V.; Heyn, Ch.; Hansen, W. [Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität Hamburg, Jungiusstr. 11, 20355 Hamburg (Germany)

2013-12-04T23:59:59.000Z

145

Durability of Low Pt Fuel Cells Operating at High Power Density  

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

SPIRE Program Kickoff SPIRE Program Kickoff Topic 3A. Cell Degradation Studies / Degradation Studies Durability of Low Pt Fuel Cells Operating at High Power Density US DOE Fuel Cell Projects Kickoff Meeting DOE Award: DE-EE0000469 October 1 st , 2009 Program Objectives The objective of this program is to study and identify strategies to assure durability of fuel cells designed to meet DOE cost targets. Technical Barriers Barrier Approach Strategy A. Durability Reinforced, Stabilized Membrane MEA Partner Durability-Enhanced Electrodes Electrocatalyst/MEA Partner Optimized Operating Conditions Parametric model & experimental studies B. Cost Low Pt Loadings (0.2 mg/cm 2 ) Electrocatalyst/MEA Partner High Power Density (>1.0W/cm 2 ) Open Flowfield Stack Metallic Stack Architecture Incumbent Derivative

146

Wind: wind power density maps at 50m above ground and 1km resolution for  

Open Energy Info (EERE)

924 924 Varnish cache server Browse Upload data GDR 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation: XID: 2142257924 Varnish cache server Wind: wind power density maps at 50m above ground and 1km resolution for Central America from NREL Dataset Summary Description (Abstract): 50 m wind power density (W/m2) maps of Central America. (Purpose): To provide information on the wind resource potential within the following countries in Central America: Belize, El Salvador, Guatemala, Honduras, and Nicaragua. Source NREL Date Released June 30th, 2004 (10 years ago) Date Updated October 30th, 2007 (7 years ago) Keywords Central America GIS maps NREL SWERA UNEP wind Data application/zip icon Download Maps (zip, 2.2 MiB) Quality Metrics

147

Wind: wind power density GIS data at 50m above ground and 1km resolution  

Open Energy Info (EERE)

7018 7018 Varnish cache server Wind: wind power density GIS data at 50m above ground and 1km resolution for Ghana from NREL Dataset Summary Description (Abstract): Raster GIS data, exported as BIL file, 50 m wind power density for Ghana. Note: BIL files can be converted to raster data in ArcInfo using the IMAGEGRID command. (Purpose): To provide information on the wind resource potential in Ghana. Values range from 0 to 620 meters. (Supplemental Information):***** Spatial Reference Information (Beg) *****Projection ParametersCoordinate System:Projection Transverse MercatorZunits W/m2Units MetersSpheroid: WGS84ParametersScale factor at central meridian: 1.0000Longitude of central meridian: -1 0 0.0Latitude of origin: 8 0 0.0False easting: 0False northing: 0Spatial InformationRaster:Number of Columns:

148

A High Power-Density Mediator-Free Microfluidic Biophotovoltaic Device for Cyanobacterial Cells  

E-Print Network (OSTI)

Biophotovoltaics has emerged as a promising technology for generating renewable energy since it relies on living organisms as inexpensive, self-repairing and readily available catalysts to produce electricity from an abundant resource - sunlight. The efficiency of biophotovoltaic cells, however, has remained significantly lower than that achievable through synthetic materials. Here, we devise a platform to harness the large power densities afforded by miniaturised geometries. To this effect, we have developed a soft-lithography approach for the fabrication of microfluidic biophotovoltaic devices that do not require membranes or mediators. Synechocystis sp. PCC 6803 cells were injected and allowed to settle on the anode, permitting the physical proximity between cells and electrode required for mediator-free operation. We demonstrate power densities of above 100 mW/m2 for a chlorophyll concentration of 100 {\\mu}M under white light, a high value for biophotovoltaic devices without extrinsic supply of additional...

Bombelli, Paolo; Herling, Therese W; Howe, Christopher J; Knowles, Tuomas P J

2014-01-01T23:59:59.000Z

149

Unconventional Electronic Reconstruction in Undoped (Ba,Sr)Fe2As2 Across the Spin Density Wave Transition  

SciTech Connect

Through a systematic high-resolution angle-resolved photoemission study of the iron pnictide compounds (Ba,Sr)Fe{sub 2}As{sub 2}, we show that the electronic structures of these compounds are significantly reconstructed across the spin density wave transition, which cannot be described by a simple folding scenario of conventional density wave ordering. Moreover, we find that LDA calculations with an incorporated suppressed magnetic moment of 0.5{mu}{sub B} can match well the details in the reconstructed electronic structure, suggesting that the nature of magnetism in the pnictides is more itinerant than local, while the origin of suppressed magnetic moment remains an important issue for future investigations.

Yi, M.

2010-06-02T23:59:59.000Z

150

Super-radiant backward-wave oscillators with enhanced power conversion  

SciTech Connect

We propose a method for a very significant increase of the peak power of a backward-wave electron oscillator operating in the non-stationary regime of the super-radiation of short rf pulses. This method is based on sectioning: a regular self-oscillator section is supported with a section providing amplification of the super-radiant pulse. Profiling of a resonant parameter in the amplifying section is used to avoid the parasitic self-excitation and to increase the efficiency of the electron-wave interaction. In such systems, the conversion factor (the ratio between the rf pulse power and the electron beam power) can achieve a few hundred percent.

Rostov, V. V. [Institute of High Current Electronics, Siberian Branch of Russian Academy of Science, Tomsk (Russian Federation); Savilov, A. V. [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia, and Lobachevsky State University of Nizhny Novgorod (Russian Federation)

2013-02-15T23:59:59.000Z

151

Experimental Investigation of the Power Generation Performance of Floating-Point Absorber Wave Energy Systems: Preprint  

SciTech Connect

The extraction of energy from ocean waves has gained interest in recent years. The floating-point absorber (FPA) is one of the most promising devices among a wide variety of wave energy conversion technologies. Early theoretical studies mainly focused on understanding the hydrodynamics of the system and on predicting the maximum power that could be extracted by a heaving body. These studies evolve from the investigation of floating-body interactions in offshore engineering and naval architecture disciplines. To our best knowledge, no systematic study has been reported about the investigation of the power generation performance of an FPA with a close-to-commercial design. A series of experimental tests was conducted to investigate the power extraction performance of an FPA system.

Li, Y.; Yu, Y.; Epler, J.; Previsic, M.

2012-04-01T23:59:59.000Z

152

Plasma diagnostics of low pressure high power impulse magnetron sputtering assisted by electron cyclotron wave resonance plasma  

SciTech Connect

This paper reports on an investigation of the hybrid pulsed sputtering source based on the combination of electron cyclotron wave resonance (ECWR) inductively coupled plasma and high power impulse magnetron sputtering (HiPIMS) of a Ti target. The plasma source, operated in an Ar atmosphere at a very low pressure of 0.03 Pa, provides plasma where the major fraction of sputtered particles is ionized. It was found that ECWR assistance increases the electron temperature during the HiPIMS pulse. The discharge current and electron density can achieve their stable maximum 10 {mu}s after the onset of the HiPIMS pulse. Further, a high concentration of double charged Ti{sup ++} with energies of up to 160 eV was detected. All of these facts were verified experimentally by time-resolved emission spectroscopy, retarding field analyzer measurement, Langmuir probe, and energy-resolved mass spectrometry.

Stranak, Vitezslav [Ernst-Moritz-Arndt-Universitaet Greifswald, Institut fuer Physik, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany); University of South Bohemia, Institute of Physics and Biophysics, Branisovska 31, 370 05 Ceske Budejovice (Czech Republic); Herrendorf, Ann-Pierra; Drache, Steffen; Bogdanowicz, Robert; Hippler, Rainer [Ernst-Moritz-Arndt-Universitaet Greifswald, Institut fuer Physik, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany); Cada, Martin; Hubicka, Zdenek [Institute of Physics v. v. i., Academy of Science of the Czech Republic, Na Slovance 2, 182 21 Prague (Czech Republic); Tichy, Milan [Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, 180 00 Prague (Czech Republic)

2012-11-01T23:59:59.000Z

153

The slow-mode nature of compressible wave power in solar wind turbulence  

E-Print Network (OSTI)

We use a large, statistical set of measurements from the Wind spacecraft at 1 AU, and supporting synthetic spacecraft data based on kinetic plasma theory, to show that the compressible component of inertial range solar wind turbulence is primarily in the kinetic slow mode. The zero-lag cross correlation C(delta n, delta B_parallel) between proton density fluctuations delta n and the field-aligned (compressible) component of the magnetic field delta B_parallel is negative and close to -1. The typical dependence of C(delta n,delta B_parallel) on the ion plasma beta_i is consistent with a spectrum of compressible wave energy that is almost entirely in the kinetic slow mode. This has important implications for both the nature of the density fluctuation spectrum and for the cascade of kinetic turbulence to short wavelengths, favoring evolution to the kinetic Alfven wave mode rather than the (fast) whistler mode.

Howes, G G; Klein, K G; Chen, C H K; Salem, C S; TenBarge, J M

2011-01-01T23:59:59.000Z

154

Potential order-of-magnitude enhancement of wind farm power density via counter-rotating vertical-axis wind  

E-Print Network (OSTI)

Potential order-of-magnitude enhancement of wind farm power density via counter-rotating vertical constraint limits the amount of power that can be extracted from a given wind farm footprint. The resulting-axis wind turbines (VAWTs) in order to achieve higher power output per unit land area than existing wind

Dabiri, John O.

155

Gas Density Fluctuations in the Perseus Cluster: Clumping Factor and Velocity Power Spectrum  

E-Print Network (OSTI)

X-ray surface brightness fluctuations in the core of the Perseus Cluster are analyzed, using deep observations with the Chandra observatory. The amplitude of gas density fluctuations on different scales is measured in a set of radial annuli. It varies from 8 to 12 per cent on scales of ~10-30 kpc within radii of 30-160 kpc from the cluster center and from 9 to 7 per cent on scales of ~20-30 kpc in an outer, 60-220 kpc annulus. Using a statistical linear relation between the observed amplitude of density fluctuations and predicted velocity, the characteristic velocity of gas motions on each scale is calculated. The typical amplitudes of the velocity outside the central 30 kpc region are 90-140 km/s on ~20-30 kpc scales and 70-100 km/s on smaller scales ~7-10 kpc. The velocity power spectrum is consistent with cascade of turbulence and its slope is in a broad agreement with the slope for canonical Kolmogorov turbulence. The gas clumping factor estimated from the power spectrum of the density fluctuations is low...

Zhuravleva, I; Arevalo, P; Schekochihin, A A; Allen, S W; Fabian, A C; Forman, W R; Sanders, J S; Simionescu, A; Sunyaev, R; Vikhlinin, A; Werner, N

2015-01-01T23:59:59.000Z

156

Impact of laser power density on tribological properties of Pulsed Laser Deposited DLC films  

SciTech Connect

Fabrication of wear resistant and low friction carbon films on the engineered substrates is considered as a challenging task for expanding the applications of diamond-like carbon (DLC) films. In this paper, pulsed laser deposition (PLD) technique is used to deposit DLC films on two different types of technologically important class of substrates such as silicon and AISI 304 stainless steel. Laser power density is one of the important parameter used to tailor the fraction of sp{sup 2} bonded amorphous carbon (a-C) and tetrahedral amorphous carbon (ta-C) made by sp{sup 3} domain in the DLC film. The I(D)/I(G) ratio decreases with the increasing laser power density which is associated with decrease in fraction of a-C/ta-C ratio. The fraction of these chemical components is quantitatively analyzed by EELS which is well supported to the data obtained from the Raman spectroscopy. Tribological properties of the DLC are associated with chemical structure of the film. However, the super low value of friction coefficient 0.003 is obtained when the film is predominantly constituted by a-C and sp{sup 2} fraction which is embedded within the clusters of ta-C. Such a particular film with super low friction coefficient is measured while it was deposited on steel at low laser power density of 2 GW/cm{sup 2}. The super low friction mechanism is explained by low sliding resistance of a-C/sp{sup 2} and ta-C clusters. Combination of excellent physical and mechanical properties of wear resistance and super low friction coefficient of DLC films is desirable for engineering applications. Moreover, the high friction coefficient of DLC films deposited at 9GW/cm{sup 2} is related to widening of the intergrain distance caused by transformation from sp{sup 2} to sp{sup 3} hybridized structure.

Gayathri, S.; Sridharan, M., E-mail: krish@igcar.gov.in, E-mail: m.sridharan@ece.sastra.edu [Functional Nanomaterials and Devices Lab, Centre for Nanotechnology and Advanced Biomaterials and School of Electrical and Electronics Engineering, SASTRA University, Thanjavur – 613 401 (India); Kumar, N.; Krishnan, R., E-mail: krish@igcar.gov.in, E-mail: m.sridharan@ece.sastra.edu; AmirthaPandian, S.; Ravindran, T. R.; Dash, S.; Tyagi, A. K. [Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam – 603 102 (India)] [Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam – 603 102 (India)

2013-12-15T23:59:59.000Z

157

MHK Projects/Coos County Offshore Wave Energy Power Plant | Open Energy  

Open Energy Info (EERE)

Coos County Offshore Wave Energy Power Plant Coos County Offshore Wave Energy Power Plant < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":5,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"500px","height":"350px","centre":false,"title":"","label":"","icon":"File:Aquamarine-marker.png","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":43.0238,"lon":-124.519,"alt":0,"address":"","icon":"http:\/\/prod-http-80-800498448.us-east-1.elb.amazonaws.com\/w\/images\/7\/74\/Aquamarine-marker.png","group":"","inlineLabel":"","visitedicon":""}]}

158

A binary ACO for controlling all-electric power take off system in wave energy converters  

Science Journals Connector (OSTI)

This paper describes a metaheuristic algorithm for controlling all-electric power take off (PTO) system of wave energy converters. It provides optimal parameter values to the controller following the instantaneously changing sea state. The output of the algorithm is used to tune the electrical control systems in the PTO system in order to provide sufficient time for the point absorber to achieve desired heaving resonance compare with the ocean wave. This maximises the power extraction capability of WECs. The method consists of a binary ant colony optimisation algorithm capable of performing optimisation in continuous space. A binary encoding method is introduced to enhance its search exploration feature, hence allowing it to find optimal solution in short time.

Phen Chiak See; Vin Cent Tai; Marta Molinas

2013-01-01T23:59:59.000Z

159

A novel high power density permanent magnet variable-speed motor  

SciTech Connect

This paper proposes a novel polyphase multipole permanent magnet motor which possesses high power density, high efficiency and excellent controllability, yet can be produced by conventional fabrication technique. The basic operating principles, design features, performance analysis and control system are described. The experimental results of a 5 kW, 1,500 rpm prototype motor and its comparison with other types of motors such as switched reluctance motor and induction motor are given. This proposed motor has the potential to compete in certain applications.

Chan, C.C.; Chen, G.H.; Jiang, J.Z.; Wang, X.Y. (Univ. of Hong Kong (Hong Kong))

1993-06-01T23:59:59.000Z

160

Experimental determination of radiated internal wave power without pressure field data  

SciTech Connect

We present a method to determine, using only velocity field data, the time-averaged energy flux (J) and total radiated power P for two-dimensional internal gravity waves. Both (J) and P are determined from expressions involving only a scalar function, the stream function ?. We test the method using data from a direct numerical simulation for tidal flow of a stratified fluid past a knife edge. The results for the radiated internal wave power given by the stream function method agree to within 0.5% with results obtained using pressure and velocity data from the numerical simulation. The results for the radiated power computed from the stream function agree well with power computed from the velocity and pressure if the starting point for the stream function computation is on a solid boundary, but if a boundary point is not available, care must be taken to choose an appropriate starting point. We also test the stream function method by applying it to laboratory data for tidal flow past a knife edge, and the results are found to agree with the direct numerical simulation. The supplementary material includes a Matlab code with a graphical user interface that can be used to compute the energy flux and power from two-dimensional velocity field data.

Lee, Frank M.; Morrison, P. J. [Physics Department and Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712–1192 (United States)] [Physics Department and Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712–1192 (United States); Paoletti, M. S.; Swinney, Harry L. [Physics Department, The University of Texas at Austin, Austin, Texas 78712–1192 (United States)] [Physics Department, The University of Texas at Austin, Austin, Texas 78712–1192 (United States)

2014-04-15T23:59:59.000Z

Note: This page contains sample records for the topic "wave power density" 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

Improved constraint on the primordial gravitational-wave density using recent cosmological data and its impact on cosmic string models  

E-Print Network (OSTI)

The production of a primordial stochastic gravitational-wave background by processes occuring in the early Universe is expected in a broad range of models. Observing this background would open a unique window onto the Universe's evolutionary history. Probes like the Cosmic Microwave Background (CMB) or the Baryon Acoustic Oscillations (BAO) can be used to set upper limits on the stochastic gravitational-wave background energy density $\\Omega_{GW}$ for frequencies above $10^{-15}$ Hz. We perform a profile likelihood analysis of the Planck CMB temperature anisotropies and gravitational lensing data combined with WMAP low-$\\ell$ polarization, BAO, South Pole Telescope and Atacama Cosmology Telescope data. We find that $\\Omega_{GW}h_{0}^{2} strings, we have derived exclusion limits in th...

Henrot-Versillé, Sophie; Leroy, Nicolas; Plaszczynski, Stéphane; Arnaud, Nicolas; Bizouard, Marie-Anne; Cavalier, Fabien; Christensen, Nelson; Couchot, François; Franco, Samuel; Hello, Patrice; Huet, Dominique; Kasprzack, Marie; Perdereau, Olivier; Spinelli, Marta; Tristram, Matthieu

2014-01-01T23:59:59.000Z

162

Effect of Pressure and Chemical Substitutions on the Charge-Density-Wave in LaAgSb2  

SciTech Connect

We present data on the crystal structure and evolution of the electrical resistivity in lightly doped La{sub 1-x}R{sub x}AgSb{sub 2} (R=Gd, Y, Ce, and Nd) at ambient pressure and in LaAgSb{sub 2} under hydrostatic pressure. The upper charge density wave transition is suppressed by both doping and pressure with substitution-related disorder being the dominant mechanism for this suppression in the former case and the anisotropic pressure dependence of the unit cell dimensions (as seen in the c/a ratio) prevailing in the latter case.

Budko,S.; Weiner, T.; Ribeiro, R.; Canfield, P.; Lee, Y.; Vogt, T.; Lacerda

2006-01-01T23:59:59.000Z

163

Response of the ionosphere to the seismic trigerred acoustic waves: Electron density and electromagnetic fluctuations  

Science Journals Connector (OSTI)

......energy is injected in the atmosphere for frequency larger than 5 mHz via this channel. Moreover...about 3.7 and 4.4 mHz, energy escape to the atmosphere is found to be an order...phenomena, such as, the plasma wave excitation, linear......

E. Alam Kherani; Philippe Lognonné; Nishant Kamath; Francois Crespon; R. Garcia

2009-01-01T23:59:59.000Z

164

Impurity-induced local density of states in a d-wave superconductor carrying a supercurrent  

E-Print Network (OSTI)

direction, the coherence peaks split into double peaks. The modulation wave vectors associated with the elastic scatterings of quasiparticles by the defect from one constant-energy piece of the Fermi surface to another are displayed as bright. or dark spots...

Zhang, DG; Ting, CS; Hu, Chia-Ren.

2005-01-01T23:59:59.000Z

165

Durability of Low Platinum Fuel Cells Operating at High Power Density  

SciTech Connect

Understanding and improving the durability of cost-competitive fuel cell stacks is imperative to successful deployment of the technology. Stacks will need to operate well beyond today’s state-of-the-art rated power density with very low platinum loading in order to achieve the cost targets set forth by DOE ($15/kW) and ultimately be competitive with incumbent technologies. An accelerated cost-reduction path presented by Nuvera focused on substantially increasing power density to address non-PGM material costs as well as platinum. The study developed a practical understanding of the degradation mechanisms impacting durability of fuel cells with low platinum loading (?0.2mg/cm2) operating at high power density (?1.0W/cm2) and worked out approaches for improving the durability of low-loaded, high-power stack designs. Of specific interest is the impact of combining low platinum loading with high power density operation, as this offers the best chance of achieving long-term cost targets. A design-of-experiments approach was utilized to reveal and quantify the sensitivity of durability-critical material properties to high current density at two levels of platinum loading (the more conventional 0.45 mgPt.cm–1 and the much lower 0.2 mgPt.cm–2) across several cell architectures. We studied the relevance of selected component accelerated stress tests (AST) to fuel cell operation in power producing mode. New stress tests (NST) were designed to investigate the sensitivity to the addition of electrical current on the ASTs, along with combined humidity and load cycles and, eventually, relate to the combined city/highway drive cycle. Changes in the cathode electrochemical surface area (ECSA) and average oxygen partial pressure on the catalyst layer with aging under AST and NST protocols were compared based on the number of completed cycles. Studies showed elevated sensitivity of Pt growth to the potential limits and the initial particle size distribution. The ECSA loss was correlated with the upper potential limit in the cycle tests, although the performance degradation was found to be a strong function of initial Pt loading. A large fraction of the voltage degradation was found due to increased mass transfer overpotentials, especially in the lower Pt loading cells. Increased mass transfer overpotentials were responsible for a large fraction of the voltage degradation at high current densities. Analysis of the impedance and polarization data indicated O2 diffusion in the aged electrode ionomer to be the main source of the increased mass transfer overpotentials. Results from the experimental parametric studies were used to inform and calibrate newly developed durability model, simulating lifetime performance of the fuel cell under variety of load-cycle protocols, electrode loadings and throughout wide range of operating conditions, including elevated-to-3.0A/cm2 current densities. Complete durability model included several sub-models: platinum dissolution-and-growth as well as reaction-diffusion model of cathode electrode, applied sequentially to study the lifetime predictions of ECSA and polarization performance in the ASTs and NSTs. These models establish relations between changes in overpotentials, ECSA and oxygen mass transport in fuel cell cathodes. The model was calibrated using single cells with land-channel and open flowfield architectures. The model was validated against Nuvera Orion® (open flowfield) short stack data in the load cycle durability tests. The reaction-diffusion model was used to correlate the effective mass transfer coefficients for O2 diffusion in cathode ionomer and separately in gas pores with the operating conditions (pressure, temperature, gas velocity in flow field and current density), Pt loading, and ageing related growth in Pt particles and thinning of the electrode. Achievements of both modeling and experimental objectives were demonstrated in a full format, subscale stacks operating in a simulated but fully realistic ambient environment, using system-compatible operating protocols.

Polevaya, Olga [Nuvera Fuel Cells Inc.] [Nuvera Fuel Cells Inc.; Blanchet, Scott [Nuvera Fuel Cells Inc.] [Nuvera Fuel Cells Inc.; Ahluwalia, Rajesh [Argonne National Lab] [Argonne National Lab; Borup, Rod [Los-Alamos National Lab] [Los-Alamos National Lab; Mukundan, Rangachary [Los-Alamos National Lab] [Los-Alamos National Lab

2014-03-19T23:59:59.000Z

166

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

167

High power millimeter wave experiment of ITER relevant electron cyclotron heating and current drive system  

SciTech Connect

High power, long pulse millimeter (mm) wave experiments of the RF test stand (RFTS) of Japan Atomic Energy Agency (JAEA) were performed. The system consists of a 1 MW/170 GHz gyrotron, a long and short distance transmission line (TL), and an equatorial launcher (EL) mock-up. The RFTS has an ITER-relevant configuration, i.e., consisted by a 1 MW-170 GHz gyrotron, a mm wave TL, and an EL mock-up. The TL is composed of a matching optics unit, evacuated circular corrugated waveguides, 6-miter bends, an in-line waveguide switch, and an isolation valve. The EL-mock-up is fabricated according to the current design of the ITER launcher. The Gaussian-like beam radiation with the steering capability of 20 deg. - 40 deg. from the EL mock-up was also successfully proved. The high power, long pulse power transmission test was conducted with the metallic load replaced by the EL mock-up, and the transmission of 1 MW/800 s and 0.5 MW/1000 s was successfully demonstrated with no arcing and no damages. The transmission efficiency of the TL was 96%. The results prove the feasibility of the ITER electron cyclotron heating and current drive system.

Takahashi, K.; Kajiwara, K.; Oda, Y.; Kasugai, A.; Kobayashi, N.; Sakamoto, K. [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan); Doane, J.; Olstad, R. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Henderson, M. [ITER Organization, CS90 046, 13067 St. Paul lez Durance Cedex (France)

2011-06-15T23:59:59.000Z

168

Wind: wind speed and wind power density maps at 10m and 50m above surface  

Open Energy Info (EERE)

maps at 10m and 50m above surface maps at 10m and 50m above surface and 0.25 degree resolution for global oceans from NREL Dataset Summary Description (Abstract): Raster GIS ASCII data files of wind speed and wind power density at 10 and 50 m heights. Global data of offshore wind resource as generated by NASA's QuikSCAT SeaWinds scatterometer. (Purpose): To provide information on the wind resource potential of offshore areas. Source NREL Date Released December 31st, 2005 (9 years ago) Date Updated November 01st, 2007 (7 years ago) Keywords GEF GIS NASA NREL SWERA UNEP wind Data application/zip icon Download Maps (zip, 36.3 MiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Time Period 2000 - 2004 License License Other or unspecified, see optional comment below

169

Wind: wind power density GIS data at 50m above ground and 1km resolution  

Open Energy Info (EERE)

Cuba from NREL Cuba from NREL Dataset Summary Description (Abstract): Raster GIS data, exported as BIL file, 50 m wind power density for Cuba. Note: BIL files can be converted to raster data in ArcInfo using the IMAGEGRID command. (Purpose): To provide information on the wind resource potential in Cuba. Values range from 0 to 547. (Supplemental Information): ***** Spatial Reference Information (Beg) *****Projection ParametersCoordinate System:Projection CylindricalZunits W/m2Units MetersSpheroid: SphereParametersProjection Type 1Longitude of central meridian: -79 32 40.2Latitude of standard parallel: 21 33 21.6Spatial InformationRaster:Number of Columns: 1360Number of Rows: 628Pixel Resolution (m): 1000Data Type: integer***** Spatial Reference Information (End) *****

170

Wind: wind power density maps at 50 m above ground and 1km resolution for  

Open Energy Info (EERE)

Cuba from NREL Cuba from NREL Dataset Summary Description (Abstract): Raster GIS data, 50 m wind power density for Cuba. (Purpose): To provide information on the wind resource potential in Cuba. Source NREL Date Released September 02nd, 2004 (10 years ago) Date Updated October 30th, 2007 (7 years ago) Keywords Cuba GEF GIS maps NREL SWERA UNEP wind Data application/zip icon Download Maps (zip, 839.7 KiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Time Period License License Open Data Commons Public Domain Dedication and Licence (PDDL) Comment Rate this dataset Usefulness of the metadata Average vote Your vote Usefulness of the dataset Average vote Your vote Ease of access Average vote Your vote Overall rating Average vote Your vote Comments

171

Wind: wind power density maps at 50m above ground and 1km resolution for  

Open Energy Info (EERE)

Ghana from NREL Ghana from NREL Dataset Summary Description (Abstract): Raster GIS data, 50 m wind power density for Ghana. (Purpose): To provide information on the wind resource potential in Ghana. Source NREL Date Released September 02nd, 2004 (10 years ago) Date Updated November 01st, 2007 (7 years ago) Keywords GEF Ghana GIS maps NREL SWERA UNEP wind Data application/zip icon Download Maps (zip, 661.4 KiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Time Period License License Open Data Commons Public Domain Dedication and Licence (PDDL) Comment Rate this dataset Usefulness of the metadata Average vote Your vote Usefulness of the dataset Average vote Your vote Ease of access Average vote Your vote Overall rating Average vote Your vote

172

Wind: wind power density GIS data at 50m above ground and 1km resolution  

Open Energy Info (EERE)

China from NREL China from NREL Dataset Summary Description (Abstract): Raster GIS data, exported as BIL file, 50 m wind power density for eastern China. (Purpose): To provide information on the wind resource potential in eastern China. Values range from 0 to 3079 W/m2. (Supplemental Information): The modeling regions do not completely cover eastern China. Projection Parameters Projection LAMBERT_AZIMUTHAL Datum WGS84 Zunits METERS Units METERS Spheroid DEFINED Major Axis 6370997.00000 Minor Axis 0.00000 Parameters: radius of the sphere of reference 6370997.00000 Continue? longitude of center of projection 119 0 0.00 latitude of center of projection 33 30 0.000 false easting (meters) 0.00000 false northing (meters) 0.00000 Spatial Information Raster: Number of Columns: 2658 Number of Rows: 3926 Pixel

173

Wind: wind speed and wind power density GIS data at 10m and 50m above  

Open Energy Info (EERE)

10m and 50m above 10m and 50m above surface and 0.25 degree resolution for global oceans from NREL Dataset Summary Description (Abstract): Raster GIS ASCII data files of wind speed and wind power density at 10 and 50 m heights. Global data of offshore wind resource as generated by NASA's QuikScat SeaWinds scatterometer. (Purpose): To provide information on the wind resource potential of offshore areas. Source NREL Date Released December 31st, 2005 (9 years ago) Date Updated November 01st, 2007 (7 years ago) Keywords GEF GIS NASA NREL ocean offshore QuikScat SWERA UNEP wind Data application/msword icon Download Documentation (doc, 53.8 KiB) application/zip icon Download Data (zip, 41 MiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Time Period 01/01/2000 - 12/31/2004

174

Wind: wind power density maps at 50 m above ground and 400m resolution for  

Open Energy Info (EERE)

400m resolution for 400m resolution for Sri Lanka from NREL Dataset Summary Description (Abstract): 50 m wind power density (W/m2) maps of Sri Lanka (Purpose): To provide information on the wind resource potential within Sri Lanka, with supplemental information on political boundaries, transmission lines, roads, and terrain relief. Source NREL Date Released June 30th, 2004 (10 years ago) Date Updated November 01st, 2007 (7 years ago) Keywords GEF GIS maps NREL Sri Lanka SWERA UNEP wind Data application/zip icon Download Maps (zip, 799.1 KiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Time Period License License Open Data Commons Public Domain Dedication and Licence (PDDL) Comment Rate this dataset Usefulness of the metadata Average vote Your vote

175

Wind: wind power density GIS data at 50m above ground and 1km resolution  

Open Energy Info (EERE)

Central America from NREL Central America from NREL Dataset Summary Description (Abstract): Raster GIS data, 50 m wind power density for Central America (Purpose): To provide information on the wind resource potential within the following countries in Central America: Belize, El Salvador, Guatemala, Honduras, and Nicaragua. (Supplemental Information): ***** Spatial Reference Information (Beg) *****Projection ParametersCoordinate System:Lambert_Azimuthal_Equal_AreaFalse_Easting: 0.000000False_Northing: 0.000000Central_Meridian: -87.450000Latitude_Of_Origin: 13.300000GCS_Sphere_ARC_INFODatum: D_Sphere_ARC_INFOPrime Meridian: 0Units: MetersSpatial InformationRaster:Number of Columns: 1374Number of Rows: 1143Pixel Resolution (m): 1000Data Type: integer***** Spatial Reference Information (End) *****

176

Wind: wind power density GIS data at 50m above ground and 400m resolution  

Open Energy Info (EERE)

400m resolution 400m resolution for Sri Lanka from NREL Dataset Summary Description (Abstract): Raster GIS data, 50 m wind power density for Sri Lanka (Purpose): To provide information on the wind resource potential within Sri Lanka and selected offshore areas (Supplemental Information): ***** Spatial Reference Information (Beg) *****Projection ParametersProjection UTMZone 44Datum WGS84Zunits NoneUnits METERSSpheroid WGS84Xshift 0.0000000000Yshift 0.0000000000ParametersSpatial InformationRaster:Number of Columns: 764Number of Rows: 1218Pixel Resolution (m): 400Data Type: real***** Spatial Reference Information (End) ***** Source NREL Date Released June 30th, 2004 (10 years ago) Date Updated November 01st, 2007 (7 years ago) Keywords GIS NREL Sri Lanka SWERA UNEP wind Data application/zip icon Download Data (zip, 771.5 KiB)

177

LOW-TEMPERATURE, ANODE-SUPPORTED HIGH POWER DENSITY SOLID OXIDE FUEL CELLS WITH NANOSTRUCTURED ELECTRODES  

SciTech Connect

A simple, approximate analysis of the effect of differing cathode and anode areas on the measurement of cell performance on anode-supported solid oxide fuel cells, wherein the cathode area is smaller than the anode area, is presented. It is shown that the effect of cathode area on cathode polarization, on electrolyte contribution, and on anode resistance, as normalized on the basis of the cathode area, is negligible. There is a small but measurable effect on anode polarization, which results from concentration polarization. Effectively, it is the result of a greater amount of fuel transported to the anode/electrolyte interface in cases wherein the anode area is larger than the cathode area. Experiments were performed on cells made with differing cathode areas and geometries. Cathodic and anodic overpotentials measured using reference electrodes, and the measured ohmic area specific resistances by current interruption, were in good agreement with expectations based on the analysis presented. At 800 C, the maximum power density measured with a cathode area of {approx}1.1 cm{sup 2} was {approx}1.65 W/cm{sup 2} compared to {approx}1.45 W/cm{sup 2} for cathode area of {approx}2 cm{sup 2}, for anode thickness of {approx}1.3 mm, with hydrogen as the fuel and air as the oxidant. At 750 C, the measured maximum power densities were {approx}1.3 W/cm{sup 2} for the cell with cathode area {approx}1.1 cm{sup 2}, and {approx}1.25 W/cm{sup 2} for the cell with cathode area {approx}2 cm{sup 2}.

Anil V. Virkar

2001-06-21T23:59:59.000Z

178

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

179

Electrochemical noise signature analysis using power and cross-spectral densities  

SciTech Connect

One of the major problems faced by desalination plants is corrosion. Various alloys have been developed, and continue to be developed to combat corrosion. Stainless steels are widely used in the desalination industry, due to their superior corrosion resistance. However, they are prone to localized corrosion in stagnant saline water. The feed water for one of the desalination plants in Bahrain is highly saline, containing reduced sulphur species. The electrochemical potential and current fluctuations for different stainless steels in different environmental conditions prevailing in the desalination plants in Bahrain have been measured. Digital signal processing and analysis methods used in other branches of science and engineering were used for the analysis and interpretation of electrochemical noise signatures. By calculating the power spectral density at various frequencies, the noise signatures were compared. The results calculated using both Fast Fourier Transform and the Maximum Entropy method agree well. The Cross spectrum between the potential and current noise reveals the frequencies held in common in addition to improving the signal to noise ratio. It is suggested that the Cross Spectral Density, which maybe related to the quantity of charge in transients, maybe indicative of localized corrosion.

Alawadhi, A.A. [Ministry of Electricity and Water, Manamq (Bahrain); Cottis, R.A. [Univ. of Manchester (United Kingdom). Corrosion and Protection Centre

1999-11-01T23:59:59.000Z

180

Tools for incorporating a D-wave contribution in Skyrme energy density functionals  

E-Print Network (OSTI)

The possibility of adding a D-wave term to the standard Skyrme effective interaction has been widely considered in the past. Such a term has been shown to appear in the next-to-next-to-leading order of the Skyrme pseudo-potential. The aim of the present article is to provide the necessary tools to incorporate this term in a fitting procedure: first, a mean-field equation written in spherical symmetry in order to describe spherical nuclei and second, the response function to detect unphysical instabilities. With these tools it will be possible to build a new fitting procedure to determine the coupling constants of the new functional.

P. Becker; D. Davesne; J. Meyer; A. Pastore; J. Navarro

2014-06-02T23:59:59.000Z

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


181

Poster presented at the OCEANS'11 Conference, September, 2011 Seeking Optimal Geometry of a Heaving Body for Improved Wave Power  

E-Print Network (OSTI)

1 Poster presented at the OCEANS'11 Conference, September, 2011 Seeking Optimal Geometry of a Heaving Body for Improved Wave Power Absorption Efficiency Rachael Hager, Nelson Fernandez and Michelle H power absorption efficiency with various shaped bodies. The goal is to optimize the geometry of a two

182

Composite Cathode for High-Power Density Solid Oxide Fuel Cells  

SciTech Connect

Reduction of solid oxide fuel cell (SOFC) operating temperature will play a key role in reducing the stack cost by allowing the use of low-cost metallic interconnects and new approaches to sealing, while making applications such as transportation more feasible. Reported results for anode-supported SOFCs show that cathode polarization resistance is the primary barrier to achieving high power densities at operating temperatures of 700 C and lower. This project aims to identify and develop composite cathodes that could reduce SOFC operating temperatures below 700 C. This effort focuses on study and use of (La,Sr)(Co,Fe)O{sub 3} (LSCF) based composite cathodes, which have arguably the best potential to substantially improve on the currently-used, (La,Sr)MnO{sub 3}-Yttria-stabilized Zirconia. During this Phase I, it was successfully demonstrated that high performances can be achieved with LSCF/Gadolinium-Doped Ceria composite cathodes on Ni-based anode supported cells operating at 700 C or lower. We studied electrochemical reactions at LSCF/Yttria-stabilized Zirconia (YSZ) interfaces, and observed chemical reactions between LSCF and YSZ. By using ceria electrolytes or YSZ electrolytes with ceria diffusion barrier layers, the chemical reactions between LSCF and electrolytes were prevented under cathode firing conditions necessary for the optimal adhesion of the cathodes. The protection provided by ceria layer is expected to be adequate for stable long-term cathode performances, but more testing is needed to verify this. Using ceria-based barrier layers, high performance Ni-YSZ anode supported cells have been demonstrated with maximum power densities of 0.8W/cm2 at 700 C and 1.6W/cm{sup 2} at 800 C. Ni-SDC anode supported cells with SDC electrolytes yielded >1W/cm{sup 2} at 600 C. We speculate that the power output of Ni-YSZ anode supported cell at 700 C and lower, was limited by the quality of the Ceria and Ceria YSZ interface. Improvements in the low-temperature performances are expected based on further development of barrier layer fabrication processes and optimization of cathode microstructure.

Ilwon Kim; Scott Barnett; Yi Jiang; Manoj Pillai; Nikkia McDonald; Dan Gostovic; Zhongryang Zhan; Jiang Liu

2004-01-31T23:59:59.000Z

183

High-Harmonic Fast-Wave Power Flow along Magnetic Field Lines in the Scrape-Off Layer of NSTX  

Science Journals Connector (OSTI)

A significant fraction of high-harmonic fast-wave (HHFW) power applied to NSTX can be lost to the scrape-off layer (SOL) and deposited in bright and hot spirals on the divertor rather than in the core plasma. We show that the HHFW power flows to these spirals along magnetic field lines passing through the SOL in front of the antenna, implying that the HHFW power couples across the entire width of the SOL rather than mostly at the antenna face. This result will help guide future efforts to understand and minimize these edge losses in order to maximize fast-wave heating and current drive.

R. J. Perkins; J. C. Hosea; G. J. Kramer; J.-W. Ahn; R. E. Bell; A. Diallo; S. Gerhardt; T. K. Gray; D. L. Green; E. F. Jaeger; M. A. Jaworski; B. P. LeBlanc; A. McLean; R. Maingi; C. K. Phillips; L. Roquemore; P. M. Ryan; S. Sabbagh; G. Taylor; J. R. Wilson

2012-07-27T23:59:59.000Z

184

High-Harmonic Fast-Wave Power Flow Along Magnetic Field Lines in the Scrape-Off Layer of NSTX  

SciTech Connect

A significant fraction of high-harmonic fast-wave (HHFW) power applied to NSTX can be lost to the scrape-off layer (SOL) and deposited in bright and hot spirals on the divertor rather than in the core plasma. We show that the HHFW power flows to these spirals along magnetic field lines passing through the SOL in front of the antenna, implying that the HHFW power couples across the entire width of the SOL rather than mostly at the antenna face. This result will help guide future efforts to understand and minimize these edge losses in order to maximize fast-wave heating and current drive.

Perkins, R. J. [Princeton Plasma Physics Laboratory (PPPL); Hosea, J. [Princeton Plasma Physics Laboratory (PPPL); Kramer, G. [Princeton Plasma Physics Laboratory (PPPL); Ahn, Joonwook [ORNL; Bell, R. E. [Princeton Plasma Physics Laboratory (PPPL); Diallo, A. [Princeton Plasma Physics Laboratory (PPPL); Gerhardt, S. [Princeton Plasma Physics Laboratory (PPPL); Gray, T. K. [Oak Ridge National Laboratory (ORNL); Green, David L [ORNL; Jaeger, Erwin Frederick [ORNL; Jaworski, M. A. [Princeton Plasma Physics Laboratory (PPPL); LeBlanc, B [Princeton Plasma Physics Laboratory (PPPL); McLean, Adam G [ORNL; Maingi, Rajesh [ORNL; Phillips, C. K. [Princeton Plasma Physics Laboratory (PPPL); Roquemore, L. [Princeton Plasma Physics Laboratory (PPPL); Ryan, Philip Michael [ORNL; Sabbagh, S. A. [Columbia University; Taylor, G. [Princeton Plasma Physics Laboratory (PPPL); Wilson, J. R. [Princeton Plasma Physics Laboratory (PPPL)

2012-01-01T23:59:59.000Z

185

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

186

Coexistence of the spini-density-wave and superconductivity in the Ba1-xKxFe2As2  

SciTech Connect

The relation between the spin-density-wave (SDW) and superconducting order is a central topic in current research on the FeAs-based high T{sub c} superconductors. Conflicting results exist in the LaFeAs(O,F)-class of materials, for which whether the SDW and superconductivity are mutually exclusive or they can coexist has not been settled. Here we show that for the (Ba,K)Fe{sub 2}As{sub 2} system, the SDW and superconductivity can coexist in an extended range of compositions. The availability of single crystalline samples and high value of the energy gaps would make the materials a model system to investigate the high T{sub c} ferropnictide superconductivity.

Bao, Wei [Los Alamos National Laboratory; Chen, H [HEFEI NAT. LAB; Ren, Y [ANL; Qiu, Y [NIST CENTER FOR NEUTRON; Liu, R [HEFEI NAT. LAB.; Wu, G H [HEFEI NAT. LAB; Wu, T [HEFEI NAT. LAB.; Xie, Y L [HEFEI NAT. LAB; Wang, F [HEFEI NAT. LAB.; Huang, Q [NIST CENTER FOR NEUTRON; Chen, X H [HEFEI NAT. LAB

2008-01-01T23:59:59.000Z

187

Improved constraint on the primordial gravitational-wave density using recent cosmological data and its impact on cosmic string models  

E-Print Network (OSTI)

The production of a primordial stochastic gravitational-wave background by processes occuring in the early Universe is expected in a broad range of models. Observing this background would open a unique window onto the Universe's evolutionary history. Probes like the Cosmic Microwave Background (CMB) or the Baryon Acoustic Oscillations (BAO) can be used to set upper limits on the stochastic gravitational-wave background energy density $\\Omega_{GW}$ for frequencies above $10^{-15}$ Hz. We perform a profile likelihood analysis of the Planck CMB temperature anisotropies and gravitational lensing data combined with WMAP low-$\\ell$ polarization, BAO, South Pole Telescope and Atacama Cosmology Telescope data. We find that $\\Omega_{GW}h_{0}^{2} strings, we have derived exclusion limits in the cosmic string parameter space. If the size of the loops is determined by gravitational back-reaction, string tension values lower than $\\sim 4 \\times 10^{-9}$ are excluded for a reconnection probability of $10^{-3}$.

Sophie Henrot-Versillé; Florent Robinet; Nicolas Leroy; Stéphane Plaszczynski; Nicolas Arnaud; Marie-Anne Bizouard; Fabien Cavalier; Nelson Christensen; François Couchot; Samuel Franco; Patrice Hello; Dominique Huet; Marie Kasprzack; Olivier Perdereau; Marta Spinelli; Matthieu Tristram

2014-08-22T23:59:59.000Z

188

Journal of Power Sources 140 (2005) 331339 Numerical study of a flat-tube high power density solid oxide fuel cell  

E-Print Network (OSTI)

) solid oxide fuel cell (SOFC) is a new design developed by Siemens Westinghouse, based on their formerly.V. All rights reserved. Keywords: Flat-tube; High power density; Solid oxide fuel cell; Simulation; Heat oxide fuel cell Part I. Heat/mass transfer and fluid flow Yixin Lu1, Laura Schaefer, Peiwen Li2

189

Fast-wave power flow along SOL field lines in NSTX and the associated power deposition profile across the SOL in front of the antenna  

Science Journals Connector (OSTI)

Fast-wave heating and current drive efficiencies can be reduced by a number of processes in the vicinity of the antenna and in the scrape-off layer (SOL). On NSTX from around 25% to more than 60% of the high-harmonic fast-wave power can be lost to the SOL regions, and a large part of this lost power flows along SOL magnetic field lines and is deposited in bright spirals on the divertor floor and ceiling. We show that field-line mapping matches the location of heat deposition on the lower divertor, albeit with a portion of the heat outside of the predictions. The field-line mapping can then be used to partially reconstruct the profile of lost fast-wave power at the midplane in front of the antenna, and the losses peak close to the last closed flux surface as well as the antenna. This profile suggests a radial standing-wave pattern formed by fast-wave propagation in the SOL, and this hypothesis will be tested on NSTX-U. RF codes must reproduce these results so that such codes can be used to understand this edge loss and to minimize RF heat deposition and erosion in the divertor region on ITER.

R.J. Perkins; J.-W. Ahn; R.E. Bell; A. Diallo; S. Gerhardt; T.K. Gray; D.L. Green; E.F. Jaeger; J.C. Hosea; M.A. Jaworski; B.P. LeBlanc; G.J. Kramer; A. McLean; R. Maingi; C.K. Phillips; M. Podestà; L. Roquemore; P.M. Ryan; S. Sabbagh; F. Scotti; G. Taylor; J.R. Wilson

2013-01-01T23:59:59.000Z

190

Fast-wave Power Flow Along SOL Field Lines In NSTX nd The Associated Power Deposition Profile Across The SOL In Front Of The Antenna  

SciTech Connect

Fast-wave heating and current drive efficiencies can be reduced by a number of processes in the vicinity of the antenna and in the scrape off layer (SOL). On NSTX from around 25% to more than 60% of the high-harmonic fast-wave power can be lost to the SOL regions, and a large part of this lost power flows along SOL magnetic field lines and is deposited in bright spirals on the divertor floor and ceiling. We show that field-line mapping matches the location of heat deposition on the lower divertor, albeit with a portion of the heat outside of the predictions. The field-line mapping can then be used to partially reconstruct the profile of lost fast-wave power at the midplane in front of the antenna, and the losses peak close to the last closed flux surface (LCFS) as well as the antenna. This profile suggests a radial standing-wave pattern formed by fast-wave propagation in the SOL, and this hypothesis will be tested on NSTX-U. Advanced RF codes must reproduce these results so that such codes can be used to understand this edge loss and to minimize RF heat deposition and erosion in the divertor region on ITER.

Perkins, Roy

2013-06-21T23:59:59.000Z

191

Analysis and Design of a High Power Density Axial Flux Permanent Magnet Linear Synchronous Machine Used for Stirling System  

Science Journals Connector (OSTI)

a high power density axial flux permanent magnet linear synchronous machine and the stirling system will be introduced. This machine is a tubular axial flux permanent magnet machine. It comprises two parts: stator and mover. With the 2D finite-element ... Keywords: permanent magnet, stirling engine, linear motor

Ping Zheng; Xuhui Gan; Lin Li

2010-09-01T23:59:59.000Z

192

The need for high density energy storage for wind turbine and solar power has proven to be a  

E-Print Network (OSTI)

1 The need for high density energy storage for wind turbine and solar power has proven cost of these components but also considerably improve their lifetime and reliability as it removes. New breakthrough for single-layer ceramic capacitors with high performance #12;2 Benefits ANU has

Botea, Adi

193

An open question: Are topological arguments helpful in setting initial conditions for transport problems and quantization criteria/ quantum computing for Density Wave physics?  

E-Print Network (OSTI)

We present derived I-E curves that match Zenier curves used to fit data experimentally with wavefunctionals congruent with the false vacuum hypothesis. The open question is whether the coefficients picked in both the wavefunctionals and the magnitude of the coefficients of the driven sine Gordon physical system should be picked by topological charge arguments that in principle appear to assign values that have a tie in with the false vacuum hypothesis first presented by Sidney Coleman. Our supposition is that indeed this is useful and that the topological arguments give evidence as to a first order phase transition which gives credence to the observed and calculated I-E curve as evidence of a quantum switching phenomena in density wave physics, one which we think with further development would have applications to quantum computing, via quantum coherent phase evolution, as outlined in this paper . This analysis is enhanced by a new phi to the fourth power field theory treatment of how to model field theory in real time evolution as given to the Author by Dr. Fred Cooper as part of a meeting in KITP, UCSB in early 2008

A. W. Beckwith

2008-05-01T23:59:59.000Z

194

LOW-TEMPERATURE, ANODE-SUPPORTED HIGH POWER DENSITY SOLID OXIDE FUEL CELLS WITH NANOSTRUCTURED ELECTRODES  

SciTech Connect

Anode-supported cells comprising Ni + yttria-stabilized zirconia (YSZ) anode, thin ({approx}10 {micro}m) YSZ electrolyte, and composite cathodes containing a mixture of La{sub 0.8}Sr{sub 0.2}MnO{sub (3-{delta})} (LSM) and La{sub 0.9}Sr{sub 0.1}Ga{sub 0.8}Mg{sub 0.2}O{sub (3-{lambda})} (LSGM) were fabricated. The relative proportions of LSGM and LSM were varied between 30 wt.% LSGM + 70 wt.% LSM and 70 wt.% LSGM + 30 wt.% LSM, while the firing temperature was varied between 1000 and 1200 C. The cathode interlayer composition had a profound effect on cathode performance at 800 C with overpotentials ranging between 60 and 425 mV at 1.0 A/cm{sup 2} and exhibiting a minimum for 50 wt.% LSGM + 50 wt.% LSM. The cathodic overpotential decreased with increasing firing temperature of the composite interlayer in the range 1000 {le} T {le} 1150 C, and then increased dramatically for the interlayer fired at 1200 C. The cell with the optimized cathode interlayer of 50 wt.% LSM + 50 wt.% LSGM fired at 1150 C exhibited an area specific cell resistance of 0.18 {Omega}cm{sup 2} and a maximum power density of 1.4 W/cm{sup 2} at 800 C. Chemical analysis revealed that LSGM reacts with YSZ above 1000 C to form the pyrochlore phase, La{sub 2}Zr{sub 2}O{sub 7}. The formation of the pyrochlore phase at the interface between the LSGM/LSM composite cathode and the YSZ electrolyte limits the firing time and temperature of the cathode interlayer.

Anil V. Virkar

2002-03-26T23:59:59.000Z

195

Low Power Body Sensor Network for Wireless ECG Based on Relaying of Creeping Waves at 2.4GHz1  

E-Print Network (OSTI)

Low Power Body Sensor Network for Wireless ECG Based on Relaying of Creeping Waves at 2.4GHz1 Engineering Rochester Institute of Technology Abstract- A wireless communication platform for ECG operating applications that demand higher data rates than ECG.1 I. INTRODUCTION The Electrocardiogram (ECG) [1

Tsouri, Gill

196

Waves  

Science Journals Connector (OSTI)

The fractal behavior of accidents like the Fukushima dai-ichi disaster gives scientists a tool ... by the projection of nuclear power incidents going forward, in Fig. 1.4c. The likelihood of a reportable incident...

Ted G. Lewis

2014-01-01T23:59:59.000Z

197

High-resolution tangential absolute extreme ultraviolet arrays for radiated power density measurements on NSTX-U  

SciTech Connect

The radiated-power-density diagnostic on the equatorial midplane for the NSTX-U tokamak will be upgraded to measure the radial structure of the photon emissivity profile with an improved radial resolution. This diagnostic will enhance the characterization and studies of power balance, impurity transport, and MHD. The layout and response expected of the new system is shown for different plasma conditions and impurity concentrations. The effect of toroidal rotation driving poloidal asymmetries in the core radiation from high-Z impurities is also addressed.

Delgado-Aparicio, L.; Bell, R. E.; Diallo, A.; Gerhardt, S. P.; Kozub, T. A.; LeBlanc, B. P.; Stratton, B. C. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States); Faust, I. [MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Tritz, K. [The Johns Hopkins University, Baltimore, Maryland 21209 (United States)

2014-11-15T23:59:59.000Z

198

The Effect of Dissolved Helium on the Density and Solvation Power of Supercritical Carbon Dioxide  

Science Journals Connector (OSTI)

......Lincoln, NE) using nitrogen and water, respectively. After...the known densities of nitrogen and water at selected temperatures...used for making the solubility measurements is illustrated...Figure 1. Here, the gas booster pump and syringe......

Zhouyao Zhang; Jerry W. King

1997-10-01T23:59:59.000Z

199

Engineering Density of States of Earth Abundant Semiconductors for Enhanced Thermoelectric Power Factor  

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

In highly mismatched semiconductor alloys, localized states of the impurities hybridize with energy bands of the host and lead to a density of states that can be optimally tuned to enhance the thermoelectric thermopower

200

LOW-TEMPERATURE, ANODE-SUPPORTED HIGH POWER DENSITY SOLID OXIDE FUEL CELLS WITH NANOSTRUCTURED ELECTRODES  

SciTech Connect

This report summarizes the work done during the entire project period, between October 1, 1999 and March 31, 2003, which includes a six-month no-cost extension. During the project, eight research papers have, either been, published, accepted for publication, or submitted for publication. In addition, several presentations have been made in technical meetings and workshops. The project also has provided support for four graduate students working towards advanced degrees. The principal technical objective of the project was to analyze the role of electrode microstructure on solid oxide fuel cell performance. Prior theoretical work conducted in our laboratory demonstrated that the particle size of composite electrodes has a profound effect on cell performance; the finer the particle size, the lower the activation polarization, the better the performance. The composite cathodes examined consisted of electronically conducting perovskites such as Sr-doped LaMnO{sub 3} (LSM) or Sr-doped LaCoO{sub 3} (LSC), which is also a mixed conductor, as the electrocatalyst, and yttria-stabilized zirconia (YSZ) or rare earth oxide doped CeO{sub 2} as the ionic conductor. The composite anodes examined were mixtures of Ni and YSZ. A procedure was developed for the synthesis of nanosize YSZ by molecular decomposition, in which unwanted species were removed by leaching, leaving behind nanosize YSZ. Anode-supported cells were made using the as-synthesized powders, or using commercially acquired powders. The electrolyte was usually a thin ({approx}10 microns), dense layer of YSZ, supported on a thick ({approx}1 mm), porous Ni + YSZ anode. The cathode was a porous mixture of electrocatalyst and an ionic conductor. Most of the cell testing was done at 800 C with hydrogen as fuel and air as the oxidant. Maximum power densities as high as 1.8 W/cm{sup 2} were demonstrated. Polarization behavior of the cells was theoretically analyzed. A limited amount of cell testing was done using liquid hydrocarbon fuels where reforming was achieved internally. Significant polarization losses also occur at the anode, especially at high fuel utilizations. An analysis of polarization losses requires that various contributions are isolated, and their dependence on pertinent parameters is quantitatively described. An investigation of fuel composition on gas transport through porous anodes was investigated and the role of fuel diluents was explored. This work showed that the molecular weight of the diluent has a significant effect on anode concentration polarization. This further showed that the presence of some molecular hydrogen is necessary to minimize polarization losses. Theoretical analysis has shown that the electrode microstructure has a profound effect on cell performance. In a series of experiments, cathode microstructural parameters were varied, without altering other parameters. Cathode microstructural parameters, especially three phase boundary (TPB) length, were estimated using techniques in quantitative stereology. Cell performance was quantitatively correlated with the relevant microstructural parameters, and charge transfer resistivity was explicitly evaluated. This is the first time that a fundamental parameter, which governs the activation polarization, has been quantitatively determined. An important parameter, which governs the cathodic activation polarization, and thus cell performance, is the ionic conductivity of the composite cathode. The traditional composite cathode is a mixture of LSM and YSZ. It is well known that Sr and Mg-doped LaGaO{sub 3} (LSGM), exhibits higher oxygen ion conductivity compared to YSZ. Cells were fabricated with composite cathodes comprising a mixture of LSM and LSGM. Studies demonstrated that LSGM-based composite cathodes exhibit excellent behavior. Studies have shown that Ni + YSZ is an excellent anode. In fact, in most cells, the principal polarization losses, at least at low fuel utilizations, are associated with the cathode. Theoretical analysis conducted in our group has also shown that anode-supported cells exhibi

Professor Anil V. Virkar

2003-05-23T23:59:59.000Z

Note: This page contains sample records for the topic "wave power density" 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

Universal power spectra for acoustic turbulence: Applications to wind waves, 1/f noise, and classical second sound  

Science Journals Connector (OSTI)

A continuum pumped full of waveenergy at an amplitude sufficiently large so that reversible nonlinearities dominate irreversible linear response becomes waveturbulent. In the limit of high nonlinearity acoustic turbulence and wind waveturbulence accumulate at 1/f and 1/f 5 power spectra respectively. A waveturbulent system can support new propagating energy modes analogous to second sound in superfluid He4. This hyperbolic (nondiffusive) transport could account for the anomalous diffusivity observed in plasma devices and for the difficulties faced in achieving confinement. The key to the understanding of these phenomena is the nonlinearity in the continuum mechanics which leads to three basic effects: (1) scattering of sound by sound to produce waves with sum and difference frequencies; (2) refraction of waves by a slowly varying (inhomogeneous) background; (3) reaction of the background due to changes in the distribution of sound waves. Details of these processes are presented in the framework of the Euler equations.

Seth Putterman; A. Larraza; P. H. Roberts

1986-01-01T23:59:59.000Z

202

Experimental Investigation Of Atmospheric Pressure Surface Wave Discharges  

SciTech Connect

Microwave atmospheric pressure discharge in neon sustained by surface waves in a dielectric tube is considered. The plasma column length was measured versus absorbed microwave power for different discharge conditions. This gives a view on the wave propagation characteristics. The predicted dependence of discharge length on the total flux of wave power based on the modified model of non-equilibrium plasma is compared with experimental values. Moreover, we present results of spectroscopic investigations of the electron density. The electron density was determined using the method based on the Stark broadening of H{beta} spectral line. The spectroscopic results we shall use developing of a model of propagation of surface wave.

Czylkowski, D.; Jasinski, M.; Nowakowska, H.; Zakrzewski, Z. [The Szewalski Institute of Fluid-Flow Machinery, Polish Academy of Sciences, Fiszera 14, 80-231 Gdansk (Poland)

2006-01-15T23:59:59.000Z

203

Power Spectrum of the density of cold atomic gas in the Galaxy towards Cas A and Cygnus A  

E-Print Network (OSTI)

We have obtained the power spectral description of the density and opacity fluctuations of the cold HI gas in the Galaxy towards Cas A, and Cygnus A. We have employed a method of deconvolution, based on CLEAN, to estimate the true power spectrum of optical depth of cold HI gas from the observed distribution, taking into account the finite extent of the background source and the incomplete sampling of optical depth over the extent of the source. We investigate the nature of the underlying spectrum of density fluctuations in the cold HI gas which would be consistent with that of the observed HI optical depth fluctuations. These power spectra for the Perseus arm towards Cas A, and for the Outer arm towards Cygnus A have a slope of 2.75 +/- 0.25 (3sigma error). The slope in the case of the Local arm towards Cygnus A is 2.5, and is significantly shallower in comparison. The linear scales probed here range from 0.01 to 3 pc. We discuss the implications of our results, the non-Kolmogorov nature of the spectrum, and the observed HI opacity variations on small transverse scales.

A. A. Deshpande; K. S. Dwarakanath; W. M. Goss

2000-07-25T23:59:59.000Z

204

Riding the Clean Energy Wave: New Projects Aim to Improve Water Power Devices  

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

The Energy Department announces two projects as part of a larger effort to deploy innovative technologies for clean, domestic power generation from water power resources.

205

Topographic power spectral density study of the effect of surface treatment processes on niobium for superconducting radio frequency accelerator cavities  

Microroughness is viewed as a critical issue for attaining optimum performance of superconducting radio frequency accelerator cavities. The principal surface smoothing methods are buffered chemical polish (BCP) and electropolish (EP). The resulting topography is characterized by atomic force microscopy (AFM). The power spectral density (PSD) of AFM data provides a more thorough description of the topography than a single-value roughness measurement. In this work, one dimensional average PSD functions derived from topography of BCP and EP with different controlled starting conditions and durations have been fitted with a combination of power law, K correlation, and shifted Gaussian models to extract characteristic parameters at different spatial harmonic scales. While the simplest characterizations of these data are not new, the systematic tracking of scale-specific roughness as a function of processing is new and offers feedback for tighter process prescriptions more knowledgably targeted at beneficial niobium topography for superconducting radio frequency applications.

Xu, Chen; Tian, Hui; Reece, Charles E.; Kelley, Michael J.

2012-04-01T23:59:59.000Z

206

Power density axial oscillations induced by Xenon dynamics: Parameter identification via genetic algorithms  

Science Journals Connector (OSTI)

In this paper we describe the axial flux oscillations in \\{PWRs\\} by means of the Onega and Kisner model (1978), a two-point xenon oscillation model based on the one-group, one-dimensional neutron diffusion equation with nonlinear power reactivity feedback and on the nonlinear xenon and iodine balance equations. We investigate the feasibility of using genetic algorithms for estimating the effective nuclear parameters involved. This approach has the advantage of allowing the periodic re-estimation of the effective parameter values pertaining to each reactor on the basis of its recent history. By so doing, other effects, such as the burn up, are automatically taken into account.

M. Marseguerra; E. Zio; G. Torri

2003-01-01T23:59:59.000Z

207

Calculation of the thrust of a wave-powered marine propelling device  

SciTech Connect

A scheme for calculating the thrust of a wave propelling device with limiters is proposed. The scheme can be extended to similar propelling devices with a more complex wing suspension or a more complex wing system.

Konstantinov, G.A.; Yakimov, Yu.L.

1995-11-01T23:59:59.000Z

208

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

209

Order-of-magnitude enhancement of wind farm power density via counter-rotating vertical-axis wind turbine arrays  

E-Print Network (OSTI)

Modern wind farms require significant land resources to separate each wind turbine from the adjacent turbine wakes. These aerodynamic constraints limit the amount of power that can be extracted from a given wind farm footprint. We conducted full-scale field tests of vertical-axis wind turbines in counter-rotating configurations under natural wind conditions. Whereas wind farms consisting of propeller-style turbines produce 2 to 3 watts of power per square meter of land area, these field tests indicate that power densities approaching 100 W m^-2 can be achieved by arranging vertical-axis wind turbines in layouts that enable them to extract energy from adjacent wakes. In addition, we calculated that the global wind resource available to 10-m tall turbines based on the present approach is approximately 225 trillion watts (TW), which significantly exceeds the global wind resource available to 80-m tall, propeller-style wind turbines, approximately 75 TW. This improvement is due to the closer spacing that can be a...

Dabiri, John O

2010-01-01T23:59:59.000Z

210

High Current Density, Long Life Cathodes for High Power RF Sources  

SciTech Connect

This program was tasked with improving the quality and expanding applications for Controlled Porosity Reservoir (CPR) cathodes. Calabazas Creek Research, Inc. (CCR) initially developed CPR cathodes on a DOE-funded SBIR program to improve cathodes for magnetron injection guns. Subsequent funding was received from the Defense Advanced Research Projects Agency. The program developed design requirements for implementation of the technology into high current density cathodes for high frequency applications. During Phase I of this program, CCR was awarded the prestigious 2011 R&D100 award for this technology. Subsequently, the technology was presented at numerous technical conferences. A patent was issued for the technology in 2009. These cathodes are now marketed by Semicon Associates, Inc. in Lexington, KY. They are the world’s largest producer of cathodes for vacuum electron devices. During this program, CCR teamed with Semicon Associates, Inc. and Ron Witherspoon, Inc. to improve the fabrication processes and expand applications for the cathodes. Specific fabrications issues included the quality of the wire winding that provides the basic structure and the sintering to bond the wires into a robust, cohesive structure. The program also developed improved techniques for integrating the resulting material into cathodes for electron guns.

Ives, Robert Lawrence [Calabazas Creek Research,, Inc.; Collins, George [Calabazas Creek Research, Inc.; Falce, Lou [Consultant; Schwartzkopf, Steve [Ron Witherspoon, Inc.; Busbaher, Daniel [Semicon Associates

2014-01-22T23:59:59.000Z

211

Electronic Instability in a Zero-Gap Semiconductor: The Charge-Density Wave in (TaSe4)2I  

We report a comprehensive study of the paradigmatic quasi-1D compound (TaSe4)2I performed by means of angle-resolved photoemission spectroscopy (ARPES) and first-principles electronic structure calculations. We find it to be a zero-gap semiconductor in the nondistorted structure, with non-negligible interchain coupling. Theory and experiment support a Peierls-like scenario for the charge-density wave formation below TCDW=263??K, where the incommensurability is a direct consequence of the finite interchain coupling. The formation of small polarons, strongly suggested by the ARPES data, explains the puzzling semiconductor-to-semiconductor transition observed in transport at TCDW.

Tournier-Colletta, C.; Moreschini, L.; Autès, G.; Moser, S.; Crepaldi, A.; Berger, H.; Walter, A. L.; Kim, K. S.; Bostwick, A.; Monceau, P.; Rotenberg, E.; Yazyev, O. V.; Grioni, M.

2013-06-01T23:59:59.000Z

212

Design of a high power density, permanent magnet, axial gap dc motor  

SciTech Connect

In the design of drive motors for undersea vehicles, the premium placed on noise suppression suggests the use of a brush-commutated dc motor. The additional constraints of weight and volume, as well as unusual configuration, presents the axial air-gap configuration, with a permanent magnet field, as a viable candidate. In such a configuration the design of the brushes and commutator and the resulting structure becomes critical. The report describes a novel solution to this problem. The basic motor consists of two discs containing permanent magnets on either side of a magnetic structure containing the copper windings. An advantage of this motor concept is that copper cooling may easily be accomplished through the use of liquid circulating through the stator windings. The role of field and armature in a conventional disc motor configuration are reversed. The two discs containing the permanent magnets are rotating. The brushes are on the discs. The magnetic structure with the coils is stationary. The commutator bars are imbedded in the stationary member. Input power is supplied to the brushes through a brush-and-slip ring assembly. An electromagnetic design analysis for a 92 ft-lb, 700 rpm motor was performed. A finite element analysis has been conducted and the results show that magnetic saturation is not a limiting factor in this design. The motor torque is achievable within weight and volume constraints. 9 figs., 1 tab.

Hawsey, R.A.; Daniel, D.S.; Thomas, R.J. (Oak Ridge National Lab., TN (USA)); Bailey, J.M. (Tennessee Univ., Knoxville, TN (USA))

1990-01-01T23:59:59.000Z

213

ORBITAL FUNCTIONALS IN STATIC AND TIME-DEPENDENT DENSITY FUNCTIONAL THEORY  

E-Print Network (OSTI)

ORBITAL FUNCTIONALS IN STATIC AND TIME-DEPENDENT DENSITY FUNCTIONAL THEORY E.K.U. Gross, T-97074 Wurzburg Germany INTRODUCTION Density functional theory (DFT) is among the most powerful quantum statements: 1 #12; 1. The ground-state density n uniquely determines the ground-state wave function [n

Gross, E.K.U.

214

CONTROL OF POPULATION DENSITIES SURROUNDING NUCLEAR POWER PLANTS. VOLUME 5 OF THE FINAL REPORT ON HEALTH AND SAFETY IMPACTS OF NUCLEAR, GEOTHERMAL, AND FOSSIL-FUEL ELECTRIC GENERATION IN CALIFORNIA  

E-Print Network (OSTI)

Standards for Nuclear Power Plants," by A.V. Nero and Y.C.Response Planning for Nuclear Power Plants in California,"Densities Surrounding Nuclear Power Plants," by A.V. Nero,

Nero, jA.V.

2010-01-01T23:59:59.000Z

215

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

216

Self-interfering matter-wave patterns generated by a moving laser obstacle in a two-dimensional Bose-Einstein condensate inside a power trap cut off by box potential boundaries  

SciTech Connect

We report the observation of highly energetic self-interfering matter-wave (SIMW) patterns generated by a moving obstacle in a two-dimensional Bose-Einstein condensate (BEC) inside a power trap cut off by hard-wall box potential boundaries. The obstacle initially excites circular dispersive waves radiating away from the center of the trap which are reflected from hard-wall box boundaries at the edges of the trap. The resulting interference between outgoing waves from the center of the trap and reflected waves from the box boundaries institutes, to the best of our knowledge, unprecedented SIMW patterns. For this purpose we simulated the time-dependent Gross-Pitaevskii equation using the split-step Crank-Nicolson method and the obstacle was modelled by a moving impenetrable Gaussian potential barrier. Various trapping geometries are considered in which the dynamics of the spatial and momentum density, as well as the energy, are considered. The momentum dynamics reveal an oscillatory behavior for the condensate fraction, indicative of excitations out of and de-excitations back into the condensate state. An oscillatory pattern for the energy dynamics reveals the presence of solitons in the system. Some vortex features are also obtained.

Sakhel, Roger R. [Department of Basic Sciences, Faculty of Information Technology, Isra University, Amman 11622 (Jordan); Sakhel, Asaad R. [Department of Applied Sciences, Faculty of Engineering Technology, Al-Balqa Applied University, Amman 11134 (Jordan); Ghassib, Humam B. [Department of Physics, The University of Jordan, Amman 11942 (Jordan)

2011-09-15T23:59:59.000Z

217

Determination of the relative power density distribution in a heterogeneous reactor from the results of measurements of the reactivity effects and the neutron importance function  

SciTech Connect

A method for experimental determination of the relative power density distribution in a heterogeneous reactor based on measurements of fuel reactivity effects and importance of neutrons from a californium source is proposed. The method was perfected on two critical assembly configurations at the NARCISS facility of the Kurchatov Institute, which simulated a small-size heterogeneous nuclear reactor. The neutron importance measurements were performed on subcritical and critical assemblies. It is shown that, along with traditionally used activation methods, the developed method can be applied to experimental studies of special features of the power density distribution in critical assemblies and reactors.

Bobrov, A. A.; Glushkov, E. S.; Zimin, A. A.; Kapitonova, A. V.; Kompaniets, G. V.; Nosov, V. I., E-mail: rpp@adis.vver.kiae.ru; Petrushenko, R. P.; Smirnov, O. N. [Russian Research Centre Kurchatov Institute (Russian Federation)

2012-12-15T23:59:59.000Z

218

Symmetric Density Functionals  

E-Print Network (OSTI)

Variations in distinct restricted spaces of wave functions generate distinct density functionals. In particular, angular momentum projected Slater determinants define a new density functional, compatible simultaneously with angular momentum quantum number and mean field descriptions.

B. G. Giraud

2005-07-13T23:59:59.000Z

219

High-power and wavelength-tunable traveling-wave semiconductor ring laser  

E-Print Network (OSTI)

in Fig. 3, to direct the TM-mode light to a 50/50 beamsplitter, which deflects 50% of the light out of the ring cavity. With the combination of a Faraday rotator and a X/2-plate, we can operate the ring laser unidirectionally. The direction... of the traveling wave is as indicated in Fig. 1. Unidirectional propagation of light can be achieved as follows: The Faraday rotator is used to rotate the polarization of the light that comes from the k/2-plate by 45', say in the clockwise direction...

Peng, En Titus

2012-06-07T23:59:59.000Z

220

Interferometric adaptive optics for high power laser pointing, wave-front control and phasing  

SciTech Connect

Implementing the capability to perform fast ignition experiments, as well as, radiography experiments on the National Ignition Facility (NIF) places stringent requirements on the control of each of the beam's pointing and overall wavefront quality. One quad of the NIF beams, 4 beam pairs, will be utilized for these experiments and hydrodynamic and particle-in-cell simulations indicate that for the fast ignition experiments, these beams will be required to deliver 50% (4.0 kJ) of their total energy (7.96 kJ) within a 40 {micro}m diameter spot at the end of a fast ignition cone target. This requirement implies a stringent pointing and overall phase conjugation error budget on the adaptive optics system used to correct these beam lines. The overall encircled energy requirement is more readily met by phasing of the beams in pairs but still requires high Strehl ratios, Sr, and rms tip/tilt errors of approximately one {micro}rad. To accomplish this task we have designed an interferometric adaptive optics system capable of beam pointing, high Strehl ratio and beam phasing with a single pixilated MEMS deformable mirror and interferometric wave-front sensor. We present the design of a testbed used to evaluate the performance of this wave-front sensor below along with simulations of its expected performance level.

Baker, K L; Stappaerts, E A; Homoelle, D C; Henesian, M A; Bliss, E S; Siders, C W; Barty, C J

2009-01-21T23:59:59.000Z

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


221

Fast-Wave Current Drive in a Toroidal Plasma  

Science Journals Connector (OSTI)

Fast-wave current drive is demonstrated in the Princeton ACT-I toroidal device. The fast Alfvén wave, in the range of high ion-cyclotron harmonics, produced 40 A of current from 1 kW of rf power coupled into a plasma by a fast-wave loop antenna. This wave excites a steady current by damping on the energetic tail of the electron distribution function in the same way as lower-hybrid current drive, except that fast-wave current drive is appropriate for higher plasma densities.

J. Goree; M. Ono; P. Colestock; R. Horton; D. McNeill; H. Park

1985-10-14T23:59:59.000Z

222

High power, continuous-wave ytterbium-doped fiber laser tunable from 976 to 1120 nm  

E-Print Network (OSTI)

narrow linewidth double-clad fiber ring laser," Opt. Express 10(2), 139­144 (2002). 6. A. Silva, K. J. Paschotta, A. C. Tropper, and D. C. Hanna, "Ring-doped cladding-pumped single- mode three-level fiber laser, and T. Thomas, "Efficient high power Yb3þ-silica fibre laser cladding-pumped at 1064 nm," Opt. Commun

Paris-Sud XI, Université de

223

Probing the plasma near high power wave launchers in fusion devices for static and dynamic electric fields  

SciTech Connect

An exploratory study was carried out in the long-pulse tokamak Tore Supra, to determine if electric fields in the plasma around high-power, RF wave launchers could be measured with non-intrusive, passive, optical emission spectroscopy. The focus was in particular on the use of the external electric field Stark effect. The feasibility was found to be strongly dependent on the spatial extent of the electric fields and overlap between regions of strong (> 1 kV/cm) electric fields and regions of plasma particle recycling and plasma-induced, spectral line emission. Most amenable to the measurement was the RF electric field in edge plasma, in front of a lower hybrid heating and current drive launcher. Electric field strengths and direction, derived from fitting the acquired spectra to a model including time-dependent Stark effect and the tokamak-range magnetic field Zeeman-effect, were found to be in good agreement with full-wave modeling of the observed launcher.

Klepper, C Christopher [ORNL; Martin, Elijah H [ORNL; Isler, Ralph C [ORNL; Colas, L. [French Atomic Energy Commission (CEA), Cadarache, St. Paul lez Durance; Goniche, M. [French Atomic Energy Commission (CEA), Cadarache, St. Paul lez Durance; Hillairet, J. [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM); Panayotis, Stephanie [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM); Jacquot, Jonathan [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM); Lotte, Ph. [French Atomic Energy Commission (CEA), Cadarache, St. Paul lez Durance; Colledani, G. [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM); Biewer, Theodore M [ORNL; Caughman, J. B. O. [Oak Ridge National Laboratory (ORNL); Ekedahl, A. [French Atomic Energy Commission (CEA), Institute for Magnetic Fusion Research (IRFM); Green, David L [ORNL; Harris, Jeffrey H [ORNL; Hillis, Donald Lee [ORNL; Shannon, Prof. Steven [North Carolina State University; Litaudon, X [French Atomic Energy Commission (CEA)

2014-01-01T23:59:59.000Z

224

ARPES study of the evolution of band structure and charge density wave properties in RTe3 ( R=Y , La, Ce, Sm, Gd, Tb, and Dy)  

SciTech Connect

We present a detailed angle-resolved photoemission spectroscopy (ARPES) investigation of the RTe3 family, which sets this system as an ideal"textbook" example for the formation of a nesting driven charge density wave (CDW). This family indeed exhibits the full range of phenomena that can be associated to CDWinstabilities, from the opening of large gaps on the best nested parts of Fermi surface (up to 0.4 eV), to the existence of residual metallic pockets. ARPES is the best suited technique to characterize these features, thanks to its unique ability to resolve the electronic structure in k space. An additional advantage of RTe3 is that theband structure can be very accurately described by a simple two dimensional tight-binding (TB) model, which allows one to understand and easily reproduce many characteristics of the CDW. In this paper, we first establish the main features of the electronic structure by comparing our ARPES measurements with the linear muffin-tinorbital band calculations. We use this to define the validity and limits of the TB model. We then present a complete description of the CDW properties and of their strong evolution as a function of R. Using simple models, we are able to reproduce perfectly the evolution of gaps in k space, the evolution of the CDW wave vector with R, and the shape of the residual metallic pockets. Finally, we give an estimation of the CDWinteraction parameters and find that the change in the electronic density of states n (EF), due to lattice expansion when different R ions are inserted, has the correct order of magnitude to explain the evolution of the CDW properties.

Hussain, Zahid; Brouet, Veronique; Yang, Wanli; Zhou, Xingjiang; Hussain, Zahid; Moore, R.G.; He, R.; Lu, D. H.; Shen, Z.X.; Laverock, J.; Dugdale, S.B.; Ru, N.; Fisher, R.

2008-01-16T23:59:59.000Z

225

Possible phase separation and weak localization in the absence of a charge-density wave in single-phase 1T-VS2  

Science Journals Connector (OSTI)

We report on a systematic study of the structural, magnetic, and transport properties of high-purity 1T-VS2 powder samples prepared under high pressure. The results differ notably from those previously obtained by deintercalating Li from LiVS2. First, no charge-density wave (CDW) is found by transmission electron microscopy down to 94 K, though ab initio phonon calculations unveil a latent CDW instability driven by an acoustic phonon softening at the wave vector qCDW?(0.21,0.21,0) previously reported in deintercalated samples. A further indication of latent lattice instability is given by an anomalous expansion of the V-S bond distance at low temperature. Second, infrared optical absorption and electrical resistivity measurements give evidence of nonmetallic properties, consistent with the observation of no CDW phase. On the other hand, magnetic susceptibility and NMR data suggest the coexistence of localized moments with metallic carriers, in agreement with ab initio band structure calculations. This discrepancy is reconciled by a picture of electron localization induced by disorder or electronic correlations leading to a phase separation of metallic and nonmetallic domains in the nm scale. We conclude that 1T-VS2 is at the verge of a CDW transition and suggest that residual electronic doping in Li deintercalated samples stabilizes a uniform CDW phase with metallic properties.

A. Gauzzi; A. Sellam; G. Rousse; Y. Klein; D. Taverna; P. Giura; M. Calandra; G. Loupias; F. Gozzo; E. Gilioli; F. Bolzoni; G. Allodi; R. De Renzi; G. L. Calestani; P. Roy

2014-06-23T23:59:59.000Z

226

Impact of anisotropic stress of free-streaming particles on gravitational waves induced by cosmological density perturbations  

E-Print Network (OSTI)

Gravitational waves (GWs) are inevitably induced at second-order in cosmological perturbations through non-linear couplings with first order scalar perturbations, whose existence is well established by recent cosmological observations. So far, the evolution and the spectrum of the secondary induced GWs have been derived by taking into account the sources of GWs only from the product of first order scalar perturbations. Here we newly investigate the effects of purely second-order anisotropic stresses of photons and neutrinos on the evolution of GWs, which have been omitted in the literature. We present a full treatment of the Einstein-Boltzmann system to calculate the spectrum of GWs with anisotropic stress based on the formalism of the cosmological perturbation theory. We find that photon anisotropic stress amplifies the amplitude of GWs by about $150 %$ whereas neutrino anisotropic stress suppress that of GWs by about $30 %$ on small scales $k\\gtrsim 1.0 h{\\rm Mpc}^{-1}$ compared to the case without anisotro...

Saga, Shohei; Sugiyama, Naoshi

2014-01-01T23:59:59.000Z

227

Train of high-power femtosecond pulses: Probe wave in a gas of prepared atoms  

E-Print Network (OSTI)

We present a new method for generating a regular train of ultrashort optical pulses in a prepared two-level medium. The train develops from incident monochromatic probe radiation travelling in a medium of atoms, which are in a quantum mechanical superposition of dressed internal states. In the frame of used linear theory for the probe radiation, the energy of individual pulses is an exponentially growing function of atom density and of interaction cross section. Pulse repetition rate is determined by the generalized Rabi frequency and can be around 1 THz and greater. We also show that the terms, extra to the dipole approximation, endow the gas by a new property: non-saturating dependence of refractive index on the dressing monochromatic field intensity. Contribution of these nonsaturating terms can be compatible with the main dipole approximation in the wavelength region of about ten micrometers (the range of CO_2 laser) or larger.

Gevorg Muradyan; A. Zh. Muradyan

2009-08-21T23:59:59.000Z

228

High Core Electron Confinement Regimes in FTU Plasmas with Low- or Reversed-Magnetic Shear and High Power Density Electron-Cyclotron-Resonance Heating  

Science Journals Connector (OSTI)

Electron temperatures in excess of 8 keV have been obtained by electron-cyclotron-resonance heating on FTU plasmas at peak densities up to 8×1019 m -3. The magnetic shear in the plasma core is low or negative, and the electron heat diffusivity remains at, or below, the Ohmic level (0.2 m 2/s), in spite of the very large heating power density (10–20 MW/m 3) which produces extremely high temperature gradients (up to 120 keV/m). The ion heat transport remains at the neoclassical level.

P. Buratti et al.

1999-01-18T23:59:59.000Z

229

Wave power extraction from a bottom-mounted oscillating water column converter with a V-shaped channel  

Science Journals Connector (OSTI)

...CW Finkl. 2009 Ocean energy. Berlin, Germany...ME . 1981 Ocean wave energy conversion. New York, NY: Wiley Interscience...Justino. 1999 OWC wave energy devices with air flow...mathematical tables. New York, NY: Dover. 23 Mavrakos...

2014-01-01T23:59:59.000Z

230

A Case Study of Wave Power Integration into the Ucluelet Area Electrical Grid Louise Anne St.Germain  

E-Print Network (OSTI)

and resulting device scaling. The results of the wave energy conversion with and without storage, as well ...................................................................................................... 9 2.3.5 Compressed air Wild Abstract Technologies exist that can capture and convert wave energy but there are few studies

Victoria, University of

231

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

232

Development of two-variable maximum power point tracking control for ocean wave energy converters utilizing a power analysis and data acquisition system.  

E-Print Network (OSTI)

??Ocean wave energy shows great potential as a developing form of renewable energy. However, challenges arise in maturing this technology to achieve cost-effective energy conversion.… (more)

Amon, Ean A.

2010-01-01T23:59:59.000Z

233

Development of a 10 kW High Temperature High Power Density Three-Phase AC-DC-AC SiC Converter  

SciTech Connect

This paper presents the development and experimental performance of a 10 kW, all SiC, 250 C junction temperature high-power-density three-phase ac-dc-ac converter. The electromagnetic interference filter, thermal system, high temperature package, and gate drive design are discussed in detail. Finally, tests confirming the feasibility and validating the theoretical basis of the prototype converter system are described.

Ning, Puqi [ORNL

2012-01-01T23:59:59.000Z

234

MAGNITUDE AND VARIANCE OF ACOUSTIC ENERGY DENSITY IN MICROCHANNEL ACOUSTOPHORESIS  

E-Print Network (OSTI)

and Martin Wiklund1 1 Dept. of Applied Physics, Royal Institute of Technology (KTH), Stockholm, SWEDEN 2 Dept modulation, Acoustic energy density, Microchannel INTRODUCTION Microchannel acoustophoresis is a powerful) causing a half-wave resonance across the channel width or height. However, a generic problem with SF

235

Kinetic Alfvén wave turbulence and formation of localized structures  

SciTech Connect

This work presents non-linear interaction of magnetosonic wave with kinetic Alfvén wave for intermediate ?-plasma (m{sub e}/m{sub i}???1). A set of dimensionless equations have been developed for analysis by considering ponderomotive force due to pump kinetic Alfvén wave in the dynamics of magnetosonic wave. Stability analysis has been done to study modulational instability or linear growth rate. Further, numerical simulation has been carried out to study the nonlinear stage of instability and resulting power spectrum applicable to solar wind around 1 AU. Due to the nonlinearity, background density of magnetosonic wave gets modified which results in localization of kinetic Alfvén wave. From the obtained results, we observed that spectral index follows k{sup ?3.0}, consistent with observation received by Cluster spacecraft for the solar wind around 1 AU. The result shows the steepening of power spectrum which may be responsible for heating and acceleration of plasma particles in solar wind.

Sharma, R. P. [Centre for Energy Studies, Indian Institute of Technology Delhi, Delhi 110016 (India)] [Centre for Energy Studies, Indian Institute of Technology Delhi, Delhi 110016 (India); Modi, K. V. [Centre for Energy Studies, Indian Institute of Technology Delhi, Delhi 110016 (India) [Centre for Energy Studies, Indian Institute of Technology Delhi, Delhi 110016 (India); Mechanical Engineering Department, Government Engineering College Valsad, Gujarat 396001 (India)

2013-08-15T23:59:59.000Z

236

Kondo effect in the paramagnetic phase of CrFe alloy with the spin-density-wave suppressed by pressure or V doping  

SciTech Connect

The pressure dependence of the resistivity {rho}(T) of (Cr+2.7 at.{percent}Fe){sub 98}V{sub 2} is measured, following a previous study of the temperature dependence of {rho}(T) in the spin-density-wave (SDW) alloy system, (Cr+2.7 at.{percent} Fe){sub 1{minus}x}(V,Mn){sub x}. The minimum in {rho}(T) in the V-doped alloys seen at T{approx_gt}T{sub N} for x{gt}1 at.{percent} is found to move to lower temperatures under pressure p in the alloy containing 2 at.{percent} V, decreasing in magnitude, and eventually, as the Neel temperature T{sub N} goes to zero at p{approx}10 kbar, becoming a very shallow minimum followed by a maximum and a rapid decrease as T{r_arrow}4.2 K. This latter behavior in the paramagnetic phase is believed to be due to the Kondo effect, while the pressure dependent minimum in {rho}(T) in the SDW phase is a manifestation of impurity resonance scattering. {copyright} {ital 1997 American Institute of Physics.}

Galkin, V.Y.; de Camargo, P.C. [Physics Department of Federal University of Parana, Curitiba 81 531 990 (Brazil)] [Physics Department of Federal University of Parana, Curitiba 81 531 990 (Brazil); Budko, S.L.; Saitovitch, E.B. [CBPF, Rio de Janeiro (Brazil)] [CBPF, Rio de Janeiro (Brazil); Fawcett, E. [Physics Department of University of Toronto, Toronto M5S 1A7 (Canada)] [Physics Department of University of Toronto, Toronto M5S 1A7 (Canada)

1997-04-01T23:59:59.000Z

237

Observations of small-scale plasma density depletions in arecibo HF heating experiments  

SciTech Connect

Observations of incoherent scattering of electromagnetic waves at UHF from Langmuir waves by a new scheme involving linear frequency modulation (chirping) of a UHF transmitter and the demodulation (dechirping) of the received signals have been applied during HF heating experiments. These observations show that the high power HF wave used for ionospheric modification creates small-scale plasma depletions instantly on a time scale of 5 ms. For a plasma frequency of 5.1 MHz, plasma frequency gradient of the order of 50 kHz/km, and power density input of the HF heater wave of 8.0 x 10/sup -5/ W/m/sup 2/ the depletion ranged from 3 to 5%. This appears to provide direct evidence that the HF-induced modifications involve Langmuir waves trapped in density cavities. copyrightAmerican Geophysical Union 1987

Isham, B.; Birkmayer, W.; Hagfors, T.; Kofman, W.

1987-05-01T23:59:59.000Z

238

Symmetry-Breaking Orbital Anisotropy Observed for Detwinned Ba(Fe1-xCox)2As2 above the Spin Density Wave Transition  

SciTech Connect

Nematicity, defined as broken rotational symmetry, has recently been observed in competing phases proximate to the superconducting phase in the cuprate high temperature superconductors. Similarly, the new iron-based high temperature superconductors exhibit a tetragonal to orthorhombic structural transition (i.e. a broken C{sub 4} symmetry) that either precedes or is coincident with a collinear spin density wave (SDW) transition in undoped parent compounds, and superconductivity arises when both transitions are suppressed via doping. Evidence for strong in-plane anisotropy in the SDW state in this family of compounds has been reported by neutron scattering, scanning tunneling microscopy, and transport measurements. Here we present an angle resolved photoemission spectroscopy study of detwinned single crystals of a representative family of electron-doped iron-arsenide superconductors, Ba(Fe{sub 1-x}Co{sub x}){sub 2}As{sub 2} in the underdoped region. The crystals were detwinned via application of in-plane uniaxial stress, enabling measurements of single domain electronic structure in the orthorhombic state. At low temperatures, our results clearly demonstrate an in-plane electronic anisotropy characterized by a large energy splitting of two orthogonal bands with dominant d{sub xz} and d{sub yz} character, which is consistent with anisotropy observed by other probes. For compositions x > 0, for which the structural transition (T{sub S}) precedes the magnetic transition (T{sub SDW}), an anisotropic splitting is observed to develop above T{sub SDW}, indicating that it is specifically associated with T{sub S}. For unstressed crystals, the band splitting is observed close to T{sub S}, whereas for stressed crystals the splitting is observed to considerably higher temperatures, revealing the presence of a surprisingly large in-plane nematic susceptibility in the electronic structure.

Yi, Ming

2011-08-19T23:59:59.000Z

239

PHYSICAL REVIEW E 86, 046204 (2012) Impedance and power fluctuations in linear chains of coupled wave chaotic cavities  

E-Print Network (OSTI)

cavities takes place through a small port, and electromagnetic energy flows in a single propagation mode of electromagnetic wave energy through a chain of coupled cavities is considered. The cavities are assumed that can be characterized as an enclosed region with ports for the ingress and egress of waves, less work

Anlage, Steven

240

On-Chip Copper-Based vs. Optical Interconnects: Delay Uncertainty, Latency, Power, and Bandwidth Density Comparative Predictions  

E-Print Network (OSTI)

On-Chip Copper-Based vs. Optical Interconnects: Delay Uncertainty, Latency, Power, and Bandwidth. Albonesi, Philippe M. Fauchet, and Eby G. Friedman Department of Electrical and Computer Engineering of Rochester, Rochester, New York, 14627 Department of Electrical and Computer Engineering,Cornell University

Friedman, Eby G.

Note: This page contains sample records for the topic "wave power density" 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

Heating of beam ions by ion acoustic waves A. Vaivads, K. Ro nnmark, T. Oscarsson, and M. Andre  

E-Print Network (OSTI)

spectral density at frequencies much below the ion gyrofrequency. The wave power decreases with increasingHeating of beam ions by ion acoustic waves A. Vaivads, K. RoÃ? nnmark, T. Oscarsson, and M. AndreÃ? Swedish Institute of Space Physics, University of UmeaÃ? , S-901 87 UMEAÃ? , Sweden Received: 30 April 1997

Paris-Sud XI, Université de

242

Mapping and Assessment of the United States Ocean Wave Energy Resource  

SciTech Connect

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. This approach is fully consistent with accepted global practice and includes the resource made available by the lateral transfer of wave energy along wave crests, which enables wave diffraction to substantially reestablish wave power densities within a few kilometers of a linear array, even for fixed terminator devices. The total available wave energy resource along the U.S. continental shelf edge, based on accumulating unit circle wave power densities, is estimated to be 2,640 TWh/yr, broken down as follows: 590 TWh/yr for the West Coast, 240 TWh/yr for the East Coast, 80 TWh/yr for the Gulf of Mexico, 1570 TWh/yr for Alaska, 130 TWh/yr for Hawaii, and 30 TWh/yr for Puerto Rico. The total recoverable wave energy resource, as constrained by an array capacity packing density of 15 megawatts per kilometer of coastline, with a 100-fold operating range between threshold and maximum operating conditions in terms of input wave power density available to such arrays, yields a total recoverable resource along the U.S. continental shelf edge of 1,170 TWh/yr, broken down as follows: 250 TWh/yr for the West Coast, 160 TWh/yr for the East Coast, 60 TWh/yr for the Gulf of Mexico, 620 TWh/yr for Alaska, 80 TWh/yr for Hawaii, and 20 TWh/yr for Puerto Rico.

Paul T. Jacobson; George Hagerman; George Scott

2011-12-01T23:59:59.000Z

243

A Comprehensive Study Of Fracture Patterns And Densities In The Geysers  

Open Energy Info (EERE)

Study Of Fracture Patterns And Densities In The Geysers Study Of Fracture Patterns And Densities In The Geysers Geothermal Reservoir Using Microearthquake Shear-Wave Splitting Tomography Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: A Comprehensive Study Of Fracture Patterns And Densities In The Geysers Geothermal Reservoir Using Microearthquake Shear-Wave Splitting Tomography Details Activities (1) Areas (1) Regions (0) Abstract: In this project we developed a method for using seismic S-wave data to map the patterns and densities of sub-surface fractures in the NW Geysers Geothermal Field/ (1) This project adds to both the general methods needed to characterize the geothermal production fractures that supply steam for power generation and to the specific knowledge of these in the Geysers area. (2)By locating zones of high fracture density it will be

244

EARLY AFTERGLOWS OF GAMMA-RAY BURSTS IN A STRATIFIED MEDIUM WITH A POWER-LAW DENSITY DISTRIBUTION  

SciTech Connect

A long-duration gamma-ray burst (GRB) has been widely thought to arise from the collapse of a massive star, and it has been suggested that its ambient medium is a homogenous interstellar medium (ISM) or a stellar wind. There are two shocks when an ultra-relativistic fireball that has been ejected during the prompt gamma-ray emission phase sweeps up the circumburst medium: a reverse shock that propagates into the fireball, and a forward shock that propagates into the ambient medium. In this paper, we investigate the temporal evolution of the dynamics and emission of these two shocks in an environment with a general density distribution of n?R {sup –k} (where R is the radius) by considering thick-shell and thin-shell cases. A GRB afterglow with one smooth onset peak at early times is understood to result from such external shocks. Thus, we can determine the medium density distribution by fitting the onset peak appearing in the light curve of an early optical afterglow. We apply our model to 19 GRBs and find that their k values are in the range of 0.4-1.4, with a typical value of k ? 1, implying that this environment is neither a homogenous ISM with k = 0 nor a typical stellar wind with k = 2. This shows that the progenitors of these GRBs might have undergone a new mass-loss evolution.

Yi, Shuang-Xi; Dai, Zi-Gao [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Wu, Xue-Feng, E-mail: dzg@nju.edu.cn [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

2013-10-20T23:59:59.000Z

245

Wind speed and power density analysis based on Weibull and Rayleigh distributions (a case study: Firouzkooh county of Iran)  

Science Journals Connector (OSTI)

Abstract The present study aimed to analyze the wind speed data of Firouzkooh region. For this purpose, the wind speed data for a 3-h period measuring over a 10-year period (2001–2010) were analyzed to calculate and estimate the wind power generation potential. Similar trends of the wind speeds were seen in different years where the highest and the lowest mean wind speeds belonged to May 2010 and June 2002, respectively. The diurnal wind speed analysis demonstrated that the fastest winds blew from 6 am to 3 pm. Weibull and Rayleigh distribution functions were applied to find out the best fitting tool to the wind speed data. Results showed that Weibull and Rayleigh distribution functions can fit the actual values of wind speed well with almost the same coefficient of determination value (R2) of 0.97. The average values of wind power based on mean and root mean cube speed approaches were 203 and 248 W m?2 year?1, respectively indicating that Firouzkooh region stands in class 4 (which is a suitable area for wind turbine establishment). Finally, wind rose diagram revealed that the prevailing wind direction falls in the sector between 180° and 270° clockwise from North.

S.H. Pishgar-Komleh; A. Keyhani; P. Sefeedpari

2015-01-01T23:59:59.000Z

246

An appraisal of the power density of current profile in the Persian Gulf and the Gulf of Oman using numerical simulation  

Science Journals Connector (OSTI)

Abstract Having more than 2000 km tidal coastline, it's expected that Iran could exploit marine renewable energies. Furthermore, marginal countries around these seas are going to develop their energy resources and marine current energy can be a reliable choice. So, the results of a three dimensional numerical model for the study of circulation in the Persian Gulf and the Gulf of Oman, have been used to assess the power density of ocean currents in these prominent water basins. The calculations are performed regarding converter's dimension and accessibility of the generated power. The results show that the current energy, in the upper 50 m layer increases in two periods of the year, late winter to early spring and late summer to early autumn. It can be asserted that the current energy in the study area increases during monsoon periods. According to the model results, the marine current energy in the Persian Gulf and the Gulf of Oman is rather substantial; but it should wait for harnessing as more efficient power conversion systems are available.

Mahmood Akhyani; Vahid Chegini; Abbasali Aliakbari Bidokhti

2015-01-01T23:59:59.000Z

247

MHK Technologies/New Knowledge Wind and Wave Renewable Mobile...  

Open Energy Info (EERE)

Wave Renewable Mobile Wind and Wave Power Plant Platform < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage New Knowledge Wind and Wave Renewable...

248

Photo-carrier radiometry of semiconductors: A novel powerful optoelectronic diffusion-wave technique for silicon process  

E-Print Network (OSTI)

Photo-carrier radiometry of semiconductors: A novel powerful optoelectronic diffusion-defect PCR images thus obtained prove that very-near-surface (where optoelectronic device fabrication takes

Mandelis, Andreas

249

Single-Frequency High-Power Continuous-Wave Oscillation at 1003 nm of an Optically Pumped Semiconductor Laser  

E-Print Network (OSTI)

reduction of the thermal resistance of the active semiconductor medium, resulting in a high power laser powers [1,2]. However the poor thermal conductivity of III-V materials might prevent an efficient heat by bonding it to a material of high thermal conductivity and good optical quality [2,4,5]. In this work we

Boyer, Edmond

250

Performance of a Wave Energy Converter with Mechanical Energy Smoothing.  

E-Print Network (OSTI)

??A wave energy converter which uses a power balancing mechanism for turning intermittent and irregular wave motion input to smoothed continuous electrical power output is… (more)

Josefsson, Andreas; Berghuvud, Ansel; Ahlin, Kjell

2011-01-01T23:59:59.000Z

251

Resuspension of Clays Under Waves  

Science Journals Connector (OSTI)

Owing to their complex form, very small size and relatively low density, clays freshly deposited in a bay are vulnerable to resuspension when agitated by waves. The model of resuspension of clays under wave motio...

Prida Thimakorn

1984-01-01T23:59:59.000Z

252

BOOMERANG: A Balloon-borne Millimeter Wave Telescope and Total Power Receiver for Mapping Anisotropy in the Cosmic Microwave Background  

E-Print Network (OSTI)

We describe BOOMERANG; a balloon-borne microwave telescope designed to map the Cosmic Microwave Background (CMB) at a resolution of 10' from the Long Duration Balloon (LDB) platform. The millimeter-wave receiver employs new technology in bolometers, readout electronics, cold re-imaging optics, millimeter-wave filters, and cryogenics to obtain high sensitivity to CMB anisotropy. Sixteen detectors observe in 4 spectral bands centered at 90, 150, 240 and 410 GHz. The wide frequency coverage, the long duration flight, the optical design and the observing strategy provide strong rejection of systematic effects. We report the flight performance of the instrument during a 10.5 day stratospheric balloon flight launched from McMurdo Station, Antarctica that mapped ~2000 square degrees of the sky.

B. P. Crill; P. A. R. Ade; D. R. Artusa; R. S. Bhatia; J. J. Bock; A. Boscaleri; P. Cardoni; S. E. Church; K. Coble; P. deBernardis; G. deTroia; P. Farese; K. M. Ganga; M. Giacometti; C. V. Haynes; E. Hivon; V. V. Hristov; A. Iacoangeli; W. C. Jones; A. E. Lange; L. Martinis; S. Masi; P. V. Mason; P. D. Mauskopf; L. Miglio; T. Montroy; C. B. Netterfield; C. G. Paine; E. Pascale; F. Piacentini; G. Polenta; F. Pongetti; G. Romeo; J. E. Ruhl; F. Scaramuzzi; D. Sforna; A. D. Turner

2002-06-14T23:59:59.000Z

253

Sandia National Laboratories: wave energy converter  

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

wave energy converter Sandia Funded to Model Power Pods for Utility-Scale Wave-Energy Converter On September 16, 2014, in Computational Modeling & Simulation, Energy, News, News &...

254

1744 OPTICS LETTERS / Vol. 24, No. 23 / December 1, 1999 High-power continuous-wave mid-infrared radiation  

E-Print Network (OSTI)

- perature and powers in excess of 200 mW are required for long-term, sensitive, and continuous monitoring, periodically poled lithium niobate (PPLN) is the nonlinear material of choice. DFG mixing of a Ti

255

Sandia National Laboratories: Water Power  

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

Engineering, Water Power Sandia researchers are investigating the seasonal effects of a wave-energy converter (WEC) array on nearshore wave propagation using SNL-SWAN. WECs were...

256

Acoustic methods to monitor sliver linear density and yarn strength  

DOE Patents (OSTI)

Methods and apparatus are provided for monitoring sliver and yarn characteristics. Transverse waves are generated relative to the sliver or yarn. At least one acoustic sensor is in contact with the sliver or yarn for detecting waves coupled to the sliver or yarn and for generating a signal. The generated signal is processed to identify the predefined characteristics including sliver or yarn linear density. The transverse waves can be generated with a high-powered acoustic transmitter spaced relative to the sliver or yarn with large amplitude pulses having a central frequency in a range between 20 KHz and 40 KHz applied to the transmitter. The transverse waves can be generated by mechanically agitating the sliver or yarn with a tapping member.

Sheen, Shuh-Haw (Naperville, IL); Chien, Hual-Te (Naperville, IL); Raptis, Apostolos C. (Downers Grove, IL)

1997-01-01T23:59:59.000Z

257

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

258

Spectral Effects on Fast Wave Core Heating and Current Drive  

SciTech Connect

Recent results obtained with high harmonic fast wave (HHFW) heating and current drive (CD) on NSTX strongly support the hypothesis that the onset of perpendicular fast wave propagation right at or very near the launcher is a primary cause for a reduction in core heating efficiency at long wavelengths that is also observed in ICRF heating experiments in numerous tokamaks. A dramatic increase in core heating efficiency was first achieved in NSTX L-mode helium majority plasmas when the onset for perpendicular wave propagation was moved away from the antenna and nearby vessel structures. Efficient core heating in deuterium majority L mode and H mode discharges, in which the edge density is typically higher than in comparable helium majority plasmas, was then accomplished by reducing the edge density in front of the launcher with lithium conditioning and avoiding operational points prone to instabilities. These results indicate that careful tailoring of the edge density profiles in ITER should be considered to limit rf power losses to the antenna and plasma facing materials. Finally, in plasmas with reduced rf power losses in the edge regions, the first direct measurements of high harmonic fast wave current drive were obtained with the motional Stark effect (MSE) diagnostic. The location and radial dependence of HHFW CD measured by MSE are in reasonable agreement with predictions from both full wave and ray tracing simulations.

C.K. Phillips, R.E. Bell, L.A. Berry, P.T. Bonoli, R.W. Harvey, J.C. Hosea, E.F. Jaeger, B.P. LeBlanc, P.M. Ryan, G. Taylor, E.J. Valeo, J.R. Wilson, J.C. Wright, H. Yuh, and the NSTX Team

2009-05-11T23:59:59.000Z

259

Analyzing power for ?-p charge exchange in the backward hemisphere from 301 to 625 MeV/c and a test of ?N partial-wave analyses  

Science Journals Connector (OSTI)

The analyzing power of ?-p??0n has been measured for p?=301-625 MeV/c with a transversely polarized target, mainly in the backward hemisphere. The final-state neutron and a ? from the ?0 were detected in coincidence with two counter arrays. Our results are compared with predictions of recent ?N partial-wave analyses by the groups of Karlsruhe-Helsinki, Carnegie-Mellon University-Lawrence Berkeley Laboratory (CMU-LBL), and Virginia Polytechnic Institute (VPI). At the lower incident energies little difference is seen among the three analyses, and there is excellent agreement with our data. At 547 MeV/c and above, our data strongly favor the VPI phases, and disagree with Karlsruhe-Helsinki and CMU-LBL analyses, which are the source of the ?N resonance parameters given in the Particle Data Group table.

G. J. Kim; J. Arends; W. J. Briscoe; J. Engelage; B. M. K. Nefkens; M. E. Sadler; M. Taragin; H. J. Ziock

1990-02-01T23:59:59.000Z

260

Numerical investigation of the physical model of a high-power electromagnetic wave in a magnetically insulated transmission line  

SciTech Connect

An efficient numerical code for simulating the propagation of a high-power electromagnetic pulse in a vacuum transmission line is required to study the physical phenomena occurring in such a line, to analyze the operation of present-day megavolt generators at an {approx}10-TW power level, and to design such new devices. The main physical theoretical principles are presented, and the stability of flows in the near-threshold region at the boundary of the regime of magnetic self-insulation is investigated based on one-dimensional telegraph equations with electron losses. Numerical (difference) methods-specifically, a method of characteristics and a finite-difference scheme-are described and their properties and effectiveness are compared by analyzing the high-frequency modes.

Samokhin, A. A. [Troitsk Institute for Innovation and Fusion Research (Russian Federation)

2010-02-15T23:59:59.000Z

Note: This page contains sample records for the topic "wave power density" 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

Energy Transfer via Solar Wind Driven Ultra Low Frequency Waves in the Earth's Magnetosphere  

E-Print Network (OSTI)

spectral density comparison Wave polarization and energywind to various sinks of wave energy in the magnetosphere.magnetosphere (where wave energy can exit the magnetosphere

Hartinger, Michael David

2012-01-01T23:59:59.000Z

262

Energy Transfer via Solar Wind Driven Ultra Low Frequency Waves in the Earth's Magnetosphere  

E-Print Network (OSTI)

spectral density comparison Wave polarization and energywind to various sinks of wave energy in the magnetosphere.a source or sink of wave energy (Southwood et al. , 1969).

Hartinger, Michael David

2012-01-01T23:59:59.000Z

263

Simultaneous propagation of heat waves induced by sawteeth and electron cyclotron heating power modulation in the RTP tokamak  

Science Journals Connector (OSTI)

The incremental electron heat diffusivity ?inc is determined in Rijnhuizen Tokamak Project plasmas by measurements of simultaneous heat pulses due to (1) the sawtooth instability and (2) modulated electron cyclotron heating. No systematic difference is observed between the two measured ?inc values, which are both significantly larger (?inc/?ePB=2-4) than the diffusivity obtained from power balance analysis, ?ePB.

G. Gorini; P. Mantica; G. M. D. Hogeweij; F. De Luca; A. Jacchia; J. A. Konings; N. J. Lopes Cardozo; M. Peters

1993-09-27T23:59:59.000Z

264

Mapping and Assessment of the United States Ocean Wave Energy Resource |  

Open Energy Info (EERE)

450 450 Varnish cache server Mapping and Assessment of the United States Ocean Wave Energy Resource 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. This approach is fully consistent with accepted global practice and includes the resource made available by the lateral transfer of wave energy along wave crests, which enables densities within a few kilometers of a linear array, even for fixed terminator devices.

265

E-Print Network 3.0 - atomic oxygen densities Sample Search Results  

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

densities Search Powered by Explorit Topic List Advanced Search Sample search results for: atomic oxygen densities...

266

E-Print Network 3.0 - atomic oxygen density Sample Search Results  

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

density Search Powered by Explorit Topic List Advanced Search Sample search results for: atomic oxygen density...

267

Sandia National Laboratories: Wave Energy Resource Characterization...  

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

Impacts of Ivanpah Solar Power Site Sandia Funded to Model Power Pods for Utility-Scale Wave-Energy Converter Wave Energy Resource Characterization at US Test Sites On September...

268

Wind Wave Float | Department of Energy  

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

(TRL 1 2 3 Component) Ocean Power Technologies (TRL 5 6 System) - PB500, 500 kW Utility-Scale PowerBuoy Project WaveBob (TRL 5 6 System) - Advanced Wave Energy Conversion Project...

269

Shock waves on complex networks  

E-Print Network (OSTI)

Power grids, road maps, and river streams are examples of infrastructural networks which are highly vulnerable to external perturbations. An abrupt local change of load (voltage, traffic density, or water level) might propagate in a cascading way and affect a significant fraction of the network. Almost discontinuous perturbations can be modeled by shock waves which can eventually interfere constructively and endanger the normal functionality of the infrastructure. We study their dynamics by solving the Burgers equation under random perturbations on several real and artificial directed graphs. Even for graphs with a narrow distribution of node properties (e.g., degree or betweenness), a steady state is reached exhibiting a heterogeneous load distribution, having a difference of one order of magnitude between the highest and average loads. Unexpectedly we find for the European power grid and for finite Watts-Strogatz networks a broad pronounced bimodal distribution for the loads. To identify the most vulnerable...

Mones, Enys; Vicsek, Tamás; Herrmann, Hans J

2014-01-01T23:59:59.000Z

270

One-dimensional full wave simulation on XB mode conversion in electron cyclotron heating  

SciTech Connect

The XB mode conversion in electron cyclotron resonance frequency heating has been studied in detail through 1D full wave simulation. The field pattern depends on the density scale length, and the wave absorption near upper hybrid resonance is maximized beyond the R(X) mode cutoff density for optimized density scale length. The simulated mode conversion efficiency has been compared with that of an analytic formula, showing good agreements except for the phase dependent term of the X wave. The mode conversion efficiency is calculated for oblique injections as well, and it is found that the efficiency decreases as the injection angles increases. Short magnetic field scale length is confirmed to relax the short density scale length condition maximizing the XB mode conversion efficiency. Finally, the simulation code is used to analyze the mode conversion and power absorption of a pre-ionization plasma in versatile experiment spherical torus.

Kim, S. H., E-mail: shkim95@kaeri.re.kr [Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Lee, H. Y.; Jo, J. G.; Hwang, Y. S. [Seoul National University, Seoul 151-742 (Korea, Republic of)

2014-06-15T23:59:59.000Z

271

Nonlinear Electron Heat Conduction Equation and Self similar method for 1-D Thermal Waves in Laser Heating of Solid Density DT Fuel  

E-Print Network (OSTI)

Electron heat conduction is one of the ways that energy transports in laser heating of fusible target material. The aim of Inertial Confinement Fusion (ICF) is to show that the thermal conductivity is strongly dependent on temperature and the equation of electron heat conduction is a nonlinear equation. In this article, we solve the one-dimensional (1-D) nonlinear electron heat conduction equation with a self-similar method (SSM). This solution has been used to investigate the propagation of 1-D thermal wave from a deuterium-tritium (DT) plane source which occurs when a giant laser pulse impinges onto a DT solid target. It corresponds to the physical problem of rapid heating of a boundary layer of material in which the energy of laser pulse is released in a finite initial thickness.

A. Mohammadian Pourtalari; M. A. Jafarizadeh; M. Ghoranneviss

2011-05-22T23:59:59.000Z

272

Constraining the gravitational wave energy density of the Universe in the Range 0.1 Hz to 1 Hz using the Apollo Seismic Array  

E-Print Network (OSTI)

In this paper, we describe an analysis of Apollo era lunar seismic data that places an upper limit on an isotropic stochastic gravitational-wave background integrated over a year in the frequency range 0.1\\,Hz -- 1\\,Hz. We find that because the Moon's ambient noise background is much quieter than that of the Earth, significant improvements over an Earth based analysis were made. We find an upper limit of $\\Omega_{\\rm GW}<1.2\\times 10^{5}$, which is three orders of magnitude smaller than a similar analysis of a global network of broadband seismometers on Earth and the best limits in this band to date. We also discuss the benefits of a potential Earth-Moon correlation search and compute the time-dependent overlap reduction function required for such an analysis. For this search, we find an upper limit an order of magnitude larger than the Moon-Moon search.

Michael Coughlin; Jan Harms

2014-09-16T23:59:59.000Z

273

Constraining the gravitational wave energy density of the Universe in the Range 0.1 Hz to 1 Hz using the Apollo Seismic Array  

E-Print Network (OSTI)

In this paper, we describe an analysis of Apollo era lunar seismic data that places an upper limit on an isotropic stochastic gravitational-wave background integrated over a year in the frequency range 0.1\\,Hz -- 1\\,Hz. We find that because the Moon's ambient noise background is much quieter than that of the Earth, significant improvements over an Earth based analysis were made. We find an upper limit of $\\Omega_{\\rm GW}<1.2\\times 10^{5}$, which is three orders of magnitude smaller than a similar analysis of a global network of broadband seismometers on Earth and the best limits in this band to date. We also discuss the benefits of a potential Earth-Moon correlation search and compute the time-dependent overlap reduction function required for such an analysis. For this search, we find an upper limit an order of magnitude larger than the Moon-Moon search.

Coughlin, Michael

2014-01-01T23:59:59.000Z

274

Detection of lower hybrid waves in the scrape-off layer of tokamak plasmas with microwave backscattering  

SciTech Connect

Microwave backscattering experiments have been performed on the Alcator C-Mod tokamak in order to investigate the propagation of lower hybrid (LH) waves in reactor-relevant, high-density plasmas. When the line-averaged density is raised above 1?×?10{sup 20} m{sup –3}, lower hybrid current drive efficiency is found to be lower than expected [Wallace et al., Phys. Plasmas 19, 062505 (2012)] and LH power is thought to be dissipated at the plasma edge. Using a single channel (60 GHz) ordinary-mode (O-mode) reflectometer system, we demonstrate radially localized LH wave measurements in the scrape-off layer of high density plasmas (n{sup ¯}{sub e}???0.9×10{sup 20}?m{sup ?3}). Measured backscattered O-mode power varies depending on the magnetic field line mapping, suggesting the resonance cone propagation of LH waves. Backscattered power is also sensitive to variations in plasma density and the launched parallel refractive index of the LH waves. LH ray-tracing simulations have been carried out to interpret the observed variations. To understand the measured LH waves in regions not magnetically connected to the launcher, two hypotheses are examined. One is the weak single pass absorption and the other is scattering of LH waves by non-linear effects.

Baek, S. G., E-mail: sgbaek@mit.edu; Shiraiwa, S.; Parker, R. R.; Bonoli, P. T.; Marmar, E. S.; Wallace, G. M.; Lau, C. [MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States)] [MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Dominguez, A.; Kramer, G. J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2014-01-15T23:59:59.000Z

275

Single-Nucleon Densities  

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

Densities Densities This web page presents single-nucleon densities calculated for a variety of nuclei in the range A=2-10 with some preliminary results for A=11,12. These are from variational Monte Carlo calculations (VMC) using the Argonne v18 two-nucleon and Urbana X three-nucleon potentials (AV18+UX). (Urbana X is intermediate between the Urbana IX and Illinois-7 models; it has the form of UIX supplemented with a two-pion S-wave piece, while the strengths of its terms are taken from the IL7 model. It does NOT have the three-pion-ring term of IL7.) These VMC wave functions are the starting trial functions for a number of recent Green's function Monte Carlo (GFMC) calculations: Brida, et al., Phys. Rev. C 84, 024319 (2011); McCutchan, et al., Phys. Rev. C 86, 024315 (2012);

276

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

277

What can wave energy learn from offshore oil and gas?  

Science Journals Connector (OSTI)

...is happening in the wind power industry. Alternatively...and access and for power valuation. Persistence modelling for wind and wave conditions...components in wave power may be problematic. By analogy with wind turbine gearboxes...

2012-01-01T23:59:59.000Z

278

E-Print Network 3.0 - advanced gravitational wave Sample Search...  

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

gravitational wave Search Powered by Explorit Topic List Advanced Search Sample search results for: advanced gravitational wave Page: << < 1 2 3 4 5 > >> 1 Gravitational waves...

279

Propagating Waves in a Monolayer of Gas-Fluidized Rods  

E-Print Network (OSTI)

We report on an observation of propagating compression waves in a quasi-two-dimensional monolayer of apolar granular rods fluidized by an upflow of air. The collective wave speed is an order of magnitude faster than the speed of the particles. This gives rise to anomalously large number fluctuations dN ~ $N^{0.72 \\pm 0.04}$, which are greater than ordinary number fluctuations of N^{1/2}. We characterize the waves by calculating the spatiotemporal power spectrum of the density. The position of observed peaks, as a function of frequency w and wavevector k, yields a linear dispersion relationship in the long-time, long-wavelength limit and a wavespeed c = w/k. Repeating this analysis for systems at different densities and air speeds, we observe a linear increase in the wavespeed with increasing packing fraction with no dependence on the airflow. Although air-fluidized rods self-propel individually or in dilute collections, the parallel and perpendicular root-mean-square speeds of the rods indicate that they no longer self-propel when propagating waves are present. Based on this mutual exclusivity, we map out the phase behavior for the existence of waves vs self-propulsion as a function of density and fluidizing airflow.

L. J. Daniels; D. J. Durian

2010-11-12T23:59:59.000Z

280

{sup 129}Xe-Cs (D{sub 1},D{sub 2}) versus {sup 129}Xe-Rb (D{sub 1}) spin-exchange optical pumping at high xenon densities using high-power laser diode arrays  

SciTech Connect

We investigate {sup 129}Xe-Cs (D{sub 1},D{sub 2}) spin exchange optical pumping (SEOP) at high Xe densities ({approx}0.12-2.44 amagat) using newly available high-power (>40 W) laser diode arrays and compare with {sup 129}Xe-Rb D{sub 1} SEOP under similar conditions. At elevated Xe densities, the spin-exchange rate (per alkali-metal atom, {gamma}{sup '}) for Cs-{sup 129}Xe is {approx}1.5-fold greater than that for Rb-{sup 129}Xe. Higher spin-exchange rates and lower {sup 129}Xe spin-destruction rates for Cs-{sup 129}Xe versus Rb-{sup 129}Xe contribute to {approx}twofold improvement in {sup 129}Xe nuclear spin polarization measured at 9.4 T - with the largest gains observed at the highest Xe densities.

Whiting, Nicholas; Eschmann, Neil A.; Goodson, Boyd M.; Barlow, Michael J. [Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois 62901 (United States); Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, NG7 2RD (United Kingdom)

2011-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "wave power density" 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

soft X-ray background as a supernova blast wave viewed from inside: solar abundance models  

SciTech Connect

A model of the soft X-ray background is presented in which the Sun is assumed to be inside an active supernova blast wave. The blast wave evolves in a preexisting cavity. The broad band surface brightnesses is explained by such a blast wave with an explosion energy of E sub approx. 5 x 10 to the 50th power ergs and radius 80 to 100 pc, using solar abundances. An approach to treating the problem of large anisotropies in the ambient medium is also explored, accommodating the observed anticorrelation between the soft X-ray surface brightness and the 21 cm column density. It is found that only for post shock temperatures below 10 6 K a shock propagating into a density enhancement will be dimmer than a similar shock in a lower density region.

Edgar, R.J.

1984-01-01T23:59:59.000Z

282

February 5, 2013 10:35 9in x 6in Advances in Wave Turbulence b1517-ch02 2nd Reading Fluctuations of the Energy Flux in Wave Turbulence  

E-Print Network (OSTI)

Measurement of the Injected Power . . . . . . . . . . . . . . . . . . . 60 2.4 Fluctuations of the Energy Flux that involve a finite mean energy flux per unit surface and density across the scales. In the case of a n Fluctuations of the Energy Flux in Wave Turbulence S. Auma^itre , E. Falcon,§ and S. Fauve SPEC, DSM, CEA

Falcon, Eric

283

Roles of Fast-Cyclotron and Alfven-Cyclotron Waves for the Multi-Ion Solar Wind  

E-Print Network (OSTI)

Using linear Vlasov theory of plasma waves and quasi-linear theory of resonant wave-particle interaction, the dispersion relations and the electromagnetic field fluctuations of fast and Alfven waves are studied for a low-beta multi-ion plasma in the inner corona. Their probable roles in heating and accelerating the solar wind via Landau and cyclotron resonances are quantified. We assume that (1) low-frequency Alfven and fast waves have the same spectral shape and the same amplitude of power spectral density; (2) these waves eventually reach ion cyclotron frequencies due to a turbulence cascade; (3) kinetic wave-particle interaction powers the solar wind. The existence of alpha particles in a dominant proton/electron plasma can trigger linear mode conversion between oblique fast-whistler and hybrid alpha-proton cyclotron waves. The fast-cyclotron waves undergo both alpha and proton cyclotron resonances. The alpha cyclotron resonance in fast-cyclotron waves is much stronger than that in Alfven-cyclotron waves. ...

Xiong, Ming

2012-01-01T23:59:59.000Z

284

Comparison between Gaussian-type orbitals and plane wave ab initio density functional theory modeling of layer silicates: Talc [Mg{sub 3}Si{sub 4}O{sub 10}(OH){sub 2}] as model system  

SciTech Connect

The quantum chemical characterization of solid state systems is conducted with many different approaches, among which the adoption of periodic boundary conditions to deal with three-dimensional infinite condensed systems. This method, coupled to the Density Functional Theory (DFT), has been proved successful in simulating a huge variety of solids. Only in relatively recent years this ab initio quantum-mechanic approach has been used for the investigation of layer silicate structures and minerals. In the present work, a systematic comparison of different DFT functionals (GGA-PBEsol and hybrid B3LYP) and basis sets (plane waves and all-electron Gaussian-type orbitals) on the geometry, energy, and phonon properties of a model layer silicate, talc [Mg{sub 3}Si{sub 4}O{sub 10}(OH){sub 2}], is presented. Long range dispersion is taken into account by DFT+D method. Results are in agreement with experimental data reported in literature, with minimal deviation given by the GTO/B3LYP-D* method regarding both axial lattice parameters and interaction energy and by PW/PBE-D for the unit-cell volume and angular values. All the considered methods adequately describe the experimental talc infrared spectrum.

Ulian, Gianfranco; Valdrè, Giovanni, E-mail: giovanni.valdre@unibo.it [Dipartimento di Scienze Biologiche e Geologico-Ambientali, Centro di Ricerca Interdisciplinare di Biomineralogia, Cristallografia e Biomateriali, Università di Bologna “Alma Mater Studiorum” Piazza di Porta San Donato 1, 40126 Bologna (Italy)] [Dipartimento di Scienze Biologiche e Geologico-Ambientali, Centro di Ricerca Interdisciplinare di Biomineralogia, Cristallografia e Biomateriali, Università di Bologna “Alma Mater Studiorum” Piazza di Porta San Donato 1, 40126 Bologna (Italy); Tosoni, Sergio [Departament de Química Física and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, C/ Martí i Franquès 1, E-08028 Barcelona (Spain)] [Departament de Química Física and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, C/ Martí i Franquès 1, E-08028 Barcelona (Spain)

2013-11-28T23:59:59.000Z

285

Finite-temperature second-order many-body perturbation and Hartree–Fock theories for one-dimensional solids: An application to Peierls and charge-density-wave transitions in conjugated polymers  

SciTech Connect

Finite-temperature extensions of ab initio Gaussian-basis-set spin-restricted Hartree–Fock (HF) and second-order many-body perturbation (MP2) theories are implemented for infinitely extended, periodic, one-dimensional solids and applied to the Peierls and charge-density-wave (CDW) transitions in polyyne and all-trans polyacetylene. The HF theory predicts insulating CDW ground states for both systems in their equidistant structures at low temperatures. In the same structures, they turn metallic at high temperatures. Starting from the “dimerized” low-temperature equilibrium structures, the systems need even higher temperatures to undergo a Peierls transition, which is accompanied by geometric as well as electronic distortions from dimerized to non-dimerized forms. The conventional finite-temperature MP2 theory shows a sign of divergence in any phase at any nonzero temperature and is useless. The renormalized finite-temperature MP2 (MP2R) theory is divergent only near metallic electronic structures, but is well behaved elsewhere. MP2R also predicts CDW and Peierls transitions occurring at two different temperatures. The effect of electron correlation is primarily to lower the Peierls transition temperature.

He, Xiao [Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801 (United States) [Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801 (United States); State Key Laboratory of Precision Spectroscopy and Department of Physics, Institute of Theoretical and Computational Science, East China Normal University, Shanghai 200062 (China); Ryu, Shinsei [Department of Physics, University of Illinois at Urbana-Champaign, 1100 West Green Street, Urbana, Illinois 61801 (United States)] [Department of Physics, University of Illinois at Urbana-Champaign, 1100 West Green Street, Urbana, Illinois 61801 (United States); Hirata, So, E-mail: sohirata@illinois.edu [Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801 (United States) [Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801 (United States); CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan)

2014-01-14T23:59:59.000Z

286

HEAVY ION HEATING DUE TO INTERACTIONS WITH OUTWARD AND INWARD ALFVEN WAVE PACKETS  

SciTech Connect

The study of simultaneous cyclotron interactions of heavy ions with outward- and inward-propagating Alfven wave packets in the solar wind was self-consistently conducted with wave-packet dynamics. It was shown that, even when the ratio of intensities of the Alfven waves propagating from the Sun and the inward propagating waves are rather large (a factor of 10 or more), the distribution function of the ions simultaneously interacting with both of the wave packets drastically differs from the distribution function formed by the interaction of ions with waves only propagating from the Sun. In the latter case, the ions acquire a shell-like distribution; in the former case, a new non-shell-type distribution with much larger effective temperatures is formed. The temporal dynamics of the ion-distribution function and the self-consistent modification of the wave-power spectral density for both the outward and inward waves were also investigated. The results refute claims by Isenberg and Hollweg that the outward-propagating waves generate the inward waves through the instability of their resonant particle shell distribution.

Galinsky, V. L.; Shevchenko, V. I., E-mail: vit@ucsd.edu [ECE Department, UC San Diego, MC 407, La Jolla, CA 92093-0407 (United States)

2012-06-01T23:59:59.000Z

287

Highly Robust Thin-Film Composite Pressure Retarded Osmosis (PRO) Hollow Fiber Membranes with High Power Densities for Renewable Salinity-Gradient Energy Generation  

Science Journals Connector (OSTI)

(1) Salinity-gradient energy (i.e., osmotic power) generated from the mixing of solutions with different salinities via pressure retarded osmosis (PRO) represents a high potential source of renewable energy. ... Thorsen, T.; Holt, T.The potential for power production from salinity gradients by pressure retarded osmosis J. Membr. ... When using saline water as the feed soln., the efficiency of the osmotic pressure decreases with increasing feed concn. ...

Gang Han; Peng Wang; Tai-Shung Chung

2013-06-17T23:59:59.000Z

288

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

289

A STUDY OF ALFVÉN WAVE PROPAGATION AND HEATING THE CHROMOSPHERE  

SciTech Connect

Alfvén wave propagation, reflection, and heating of the chromosphere are studied for a one-dimensional solar atmosphere by self-consistently solving plasma, neutral fluid, and Maxwell's equations with incorporation of the Hall effect and strong electron-neutral, electron-ion, and ion-neutral collisions. We have developed a numerical model based on an implicit backward difference formula of second-order accuracy both in time and space to solve stiff governing equations resulting from strong inter-species collisions. A non-reflecting boundary condition is applied to the top boundary so that the wave reflection within the simulation domain can be unambiguously determined. It is shown that due to the density gradient the Alfvén waves are partially reflected throughout the chromosphere and more strongly at higher altitudes with the strongest reflection at the transition region. The waves are damped in the lower chromosphere dominantly through Joule dissipation, producing heating strong enough to balance the radiative loss for the quiet chromosphere without invoking anomalous processes or turbulences. The heating rates are larger for weaker background magnetic fields below ?500 km with higher-frequency waves subject to heavier damping. There is an upper cutoff frequency, depending on the background magnetic field, above which the waves are completely damped. At the frequencies below which the waves are not strongly damped, the interaction of reflected waves with the upward propagating waves produces power at their double frequencies, which leads to more damping. The wave energy flux transmitted to the corona is one order of magnitude smaller than that of the driving source.

Tu, Jiannan; Song, Paul [Physics Department and Center for Atmospheric Research, University of Massachusetts, Lowell, MA 01854 (United States)

2013-11-01T23:59:59.000Z

290

MHK Technologies/Hybrid wave Wind Wave pumps and turbins | Open Energy  

Open Energy Info (EERE)

Wind Wave pumps and turbins Wind Wave pumps and turbins < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Hybrid wave Wind Wave pumps and turbins.jpg Technology Profile Primary Organization Ocean Wave Wind Energy Ltd OWWE Technology Resource Click here Wave Technology Type Click here Point Absorber - Floating Technology Readiness Level Click here TRL 1 3 Discovery Concept Def Early Stage Dev Design Engineering Technology Description 2Wave1Wind The hybrid wave power rig uses two wave converting technologies in addition to wind mills The main system is a pneumatic float in the category of overtopping as Wave Dragon In addition the pneumatic float can house point absorbers The hybrid wave power rig is based on the patented wave energy converter from 2005

291

Quantum coherent switch utilizing commensurate nanoelectrode and charge density periodicities  

DOE Patents (OSTI)

A quantum coherent switch having a substrate formed from a density wave (DW) material capable of having a periodic electron density modulation or spin density modulation, a dielectric layer formed onto a surface of the substrate that is orthogonal to an intrinsic wave vector of the DW material; and structure for applying an external spatially periodic electrostatic potential over the dielectric layer.

Harrison, Neil (Santa Fe, NM); Singleton, John (Los Alamos, NM); Migliori, Albert (Santa Fe, NM)

2008-08-05T23:59:59.000Z

292

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

293

Density | OpenEI  

Open Energy Info (EERE)

Density Density Dataset Summary Description This dataset is part of a larger internal dataset at the National Renewable Energy Laboratory (NREL) that explores various characteristics of large solar electric (both PV and CSP) facilities around the United States. This dataset focuses on the land use characteristics for solar facilities that are either under construction or currently in operation. Source Land-Use Requirements for Solar Power Plants in the United States Date Released June 25th, 2013 (5 months ago) Date Updated Unknown Keywords acres area average concentrating solar power csp Density electric hectares km2 land land requirements land use land-use mean photovoltaic photovoltaics PV solar statistics Data application/vnd.openxmlformats-officedocument.spreadsheetml.sheet icon Master Solar Land Use Spreadsheet (xlsx, 1.5 MiB)

294

E-Print Network 3.0 - acoustic waves propagating Sample Search...  

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

propagating Search Powered by Explorit Topic List Advanced Search Sample search results for: acoustic waves propagating...

295

E-Print Network 3.0 - acoustic waves propagation Sample Search...  

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

propagation Search Powered by Explorit Topic List Advanced Search Sample search results for: acoustic waves propagation...

296

Spectral broadening measurement of the lower hybrid waves during long pulse operation in Tore Supra  

SciTech Connect

On many tokamaks (C-Mod, EAST, FTU, JET, HT-7, TS), a decrease in current drive efficiency of the Lower Hybrid (LH) waves is observed in high electron density plasmas. The cause of this behaviour is believed to be: Parametric Instabilities (PI) and Scattering from Density Fluctuations (SDF). For the ITER LH system, our knowledge must be improved to avoid such effects and to maintain the LH current drive efficiency at high density. The ITPA IOS group coordinates this effort [1] and all experimental data are essential to validate the numerical codes in progress. Usually the broadening of the LH wave frequency spectrum is measured by a probe located in the plasma edge. For this study, the frequency spectrum of a reflected power signal from the LH antenna was used. In addition, the spectrum measurements are compared with the density fluctuations observed on RF probes located at the antenna mouth. Several plasma currents (0.6 to 1.4 MA) and densities up to 5.2 × 10{sup 19} m?3 have been realised on Tore Supra (TS) long pulses and with high injected RF power, up to 5.4 MW-30s. This allowed using a spectrum analyser to make several measurements during the plasma pulse. The side lobe amplitude, shifted by 20-30MHz with respect to the main peak, grows with increasing density. Furthermore, for an increase of plasma current at the same density, the spectra broaden and become asymmetric. Some parametric dependencies are shown in this paper.

Berger-By, G.; Decampy, J.; Goniche, M.; Ekedahl, A.; Delpech, L.; Leroux, F. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Antar, G. Y. [American University of Beirut, Riad el-Solh, Beirut 1107-2020 (Lebanon); Collaboration: Tore Supra Team

2014-02-12T23:59:59.000Z

297

Engineering Density of States of Earth Abundant Semiconductors...  

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

Density of States of Earth Abundant Semiconductors for Enhanced Thermoelectric Power Factor Engineering Density of States of Earth Abundant Semiconductors for Enhanced...

298

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...

299

A Comprehensive Study Of Fracture Patterns And Densities In The...  

Open Energy Info (EERE)

Study Of Fracture Patterns And Densities In The Geysers Geothermal Reservoir Using Microearthquake Shear-Wave Splitting Tomography Jump to: navigation, search OpenEI Reference...

300

Energy and Energy Flux in Planetary Waves  

Science Journals Connector (OSTI)

...research-article Energy and Energy Flux in Planetary Waves V. T. Buchwald The propagation...a thorough study of the energy of these waves in the plane approximation...case of divergent planetary waves, the total energy density being E = T + U...

1972-01-01T23:59:59.000Z

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


301

Recent Developments in High-Harmonic Fast Wave Physics in NSTX  

SciTech Connect

Understanding the interaction between ion cyclotron range of frequency (ICRF) fast waves and the fast-ions created by neutral beam injection (NBI) is critical for future devices such as ITER, which rely on a combination ICRF and NBI. Experiments in NSTX which use 30 MHz High-Harmonic Fast-Wave (HHFW) ICRF and NBI heating show a competition between electron heating via Landau damping and transit-time magnetic pumping, and radio-frequency wave acceleration of NBI generated fast ions. Understanding and mitigating some of the power loss mechanisms outside the last closed flux surface (LCFS) has resulted in improved HHFW heating inside the LCFS. Nevertheless a significant fraction of the HHFW power is diverted away from the enclosed plasma. Part of this power is observed locally on the divertor. Experimental observations point toward the radio-frequency (RF) excitation of surface waves, which disperse wave power outside the LCFS, as a leading loss mechanism. Lithium coatings lower the density at the antenna, thereby moving the critical density for perpendicular fast-wave propagation away from the antenna and surrounding material surfaces. Visible and infrared imaging reveal flows of RF power along open field lines into the divertor region. In L-mode -- low average NBI power -- conditions, the fast-ion D-alpha (FIDA) diagnostic measures a near doubling and broadening of the density profile of the upper energetic level of the fast ions concurrent with the presence of HHFW power launched with k// =-8m-1. We are able to heat NBI-induced H-mode plasmas with HHFW. The captured power is expected to be split between absorption by the electrons and absorption by the fast ions, based on TORIC calculation. In the case discussed here the Te increases over the whole profile when ~2MW of HHFW power with antenna k// =13m-1 is applied after the H-mode transition.. But somewhat unexpectedly fast-ion diagnostics do not observe a change between the HHFW heated NBI discharge and the reference NBI only plasma, although an increase in neutron production is measured. __________________________________________________

B.P. LeBlanc, R.E. Bell, P. Bonoli, R. Harvey, W.W. Heidbrink, J.C. Hosea, S.M. Kaye, D. Liu, R. Maingi, S.S. Medley, M. Ono, M. Podestà, C.K. Phillips, P.M. Ryan, A.L. Roquemore, G. Taylor, J.R. Wilson and the NSTX Team

2010-10-06T23:59:59.000Z

302

Wave Energy Basics | Department of Energy  

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

Wave Energy Basics Wave Energy Basics Wave Energy Basics August 16, 2013 - 4:30pm Addthis Photo of a large wave. Wave energy technologies extract energy directly from surface waves or from pressure fluctuations below the surface. Renewable energy analysts believe there is enough energy in ocean waves to provide up to 2 terawatts of electricity. (A terawatt is equal to a trillion watts.) However, wave energy cannot be harnessed everywhere. Wave power-rich areas of the world include the western coasts of Scotland, northern Canada, southern Africa, and Australia as well as the northeastern and northwestern coasts of the United States. In the Pacific Northwest alone, it is feasible that wave energy could produce 40-70 kilowatts (kW) per 3.3 feet (1 meter) of western coastline. Wave Energy Technologies

303

ANTENNA RADIATION NEAR THE LOCAL PLASMA FREQUENCY BY LANGMUIR WAVE EIGENMODES  

SciTech Connect

Langmuir waves (LWs) in the solar wind are generated by electron beams associated with solar flares, interplanetary shock fronts, planetary bow shocks, and magnetic holes. In principle, LWs localized as eigenmodes of density fluctuations can emit electromagnetic (EM) radiation by an antenna mechanism near the local plasma frequency f{sub p} and twice the local plasma frequency. In this work, analytic expressions are derived for the radiated electric and magnetic fields and power generated near f{sub p} by LW eigenmodes. The EM wave power emitted near f{sub p} is predicted as a function of the eigenmode length scale L, maximum electric field, driving electron beam speed, and the ambient plasma density and temperature. The escape to a distant observer of f{sub p} radiation from a localized Langmuir eigenmode is also briefly explored as a function of the plasma conditions.

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., E-mail: David.Malaspina@lasp.colorado.edu, E-mail: cairns@physics.usyd.edu.au, E-mail: ree@lasp.colorado.edu [Laboratory for Atmospheric and Space Physics, Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80303 (United States)

2012-08-10T23:59:59.000Z

304

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

305

Thermodynamics of the Transformation of Gravitational Waves into Matter Quantums for a Vacuum Space Model  

E-Print Network (OSTI)

It is shown that the entropy of low density monochromatic gravitational waves, waves required for the stabilization of the crystalline structure of vacuum cosmic space, varies with the volume in the same manner as the entropy of an ideal gas formed by particles. This implies that close enough to the big-bang event the energy of all the 10 to the 120 power gravitational waves, under an adiabatic compression process, which stabilizes the crystalline structure of vacuum space behaves thermodynamically as though it is consisted of a number nB = 10 to the 80 power of independent energy or matter quanta (neutrons). PACS numbers: 03.50.De, 03.65.-w, 04.20.-q, 61.50.-f, 65.50.+m, 98.80.Ft, 97.60.Lf

J. A. Montemayor-Aldrete; M. Lopez de Haro; J. R. Morones-Ibarra; A. Morales-Mori; Mendoza-Allende; E. Cabrera-Bravo; A. Montemayor-Varela

2005-09-06T23:59:59.000Z

306

Sandia National Laboratories: Water Power  

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

Water Power Sandia-NREL Wave Energy Converter (WEC)-Sim Development Meeting On August 28, 2013, in Computational Modeling & Simulation, Energy, Partnership, Renewable Energy, Water...

307

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

308

Excitation of lower hybrid waves by a gyrating ion beam in a negative ion plasma  

SciTech Connect

A gyrating ion beam propagating through a magnetized plasma cylinder containing K{sup +} positive ions, electrons, and SF{sub 6}{sup -} negative ions drives electrostatic lower hybrid waves to instability via Cyclotron interaction. Numerical calculations of the unstable mode frequencies and growth rates of both the unstable positive ion and negative ion modes have been carried out for the existing negative ion plasma parameters. It is found that the unstable mode frequencies of both the modes increase, with the relative density of negative ions. In addition, the growth rates of both the unstable modes also increases with relative density of negative ions. Moreover, the growth rates of both the unstable modes scale as the one-third power of the beam density. The frequencies of both the unstable modes also increase with the magnetic fields. The real part of the unstable wave frequency increases as almost the square root of the beam energy.

Sharma, Jyotsna; Jain, V. K. [Physics Group, School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110 067 (India); Sharma, Suresh C. [Department of Applied Physics, Delhi Technological University, Shahbad Daulatpur, Bawana Road, Delhi 110 042 (India); Gahlot, Ajay [Department of Physics, Maharaja Surajmal Institute of Technology, Janakpuri, New Delhi (India)

2013-03-15T23:59:59.000Z

309

Energy in density gradient  

E-Print Network (OSTI)

Inhomogeneous plasmas and fluids contain energy stored in inhomogeneity and they naturally tend to relax into lower energy states by developing instabilities or by diffusion. But the actual amount of energy in such inhomogeneities has remained unknown. In the present work the amount of energy stored in a density gradient is calculated for several specific density profiles in a cylindric configuration. This is of practical importance for drift wave instability in various plasmas, and in particular in its application in models dealing with the heating of solar corona because the instability is accompanied with stochastic heating, so the energy contained in inhomogeneity is effectively transformed into heat. It is shown that even for a rather moderate increase of the density at the axis in magnetic structures in the corona by a factor 1.5 or 3, the amount of excess energy per unit volume stored in such a density gradient becomes several orders of magnitude greater than the amount of total energy losses per unit ...

Vranjes, J

2015-01-01T23:59:59.000Z

310

Generation of Gaussian Density Fields  

E-Print Network (OSTI)

This document describes analytical and numerical techniques for the generation of Gaussian density fields, which represent cosmological density perturbations. The mathematical techniques involved in the generation of density harmonics in k-space, the filtering of the density fields, and the normalization of the power spectrum to the measured temperature fluctuations of the Cosmic Microwave Background, are presented in details. These techniques are well-known amongst experts, but the current literature lacks a formal description. I hope that this technical report will prove useful to new researchers moving into this field, sparing them the task of reinventing the wheel.

Hugo Martel

2005-06-22T23:59:59.000Z

311

5 - Surface Wave Plasma Sources  

Science Journals Connector (OSTI)

Publisher Summary This chapter summarizes the advantages of the surface wave (SW) plasma sources. It includes a summary of the wave and plasma properties of SW sustained plasma columns, review of the essential parts composing a SW plasma source; describes a family of efficient SW launchers for such plasma sources, dwells on three typical experimental arrangements and a brief summary recalling the advantages of SW plasma sources. Surface wave discharges have the advantage of the broadest operating conditions in terms of frequency, tube dimensions and shape, and gas pressure. For example they can be utilized over both the RF (radiofrequency) and microwave domains, which permits one to optimize given processes as a function of frequency (generally through changes in the electron energy distribution function). A further advantage of SW plasmas is that they are the best modeled HF plasmas. This provides insight into HF discharges in general since, to a first approximation, the local plasma properties of SW discharges are the same as in all RF and microwave discharges under given discharge conditions, and for a given HF power density deposited in the plasma. Compared to other RF and microwave plasma sources, SW discharges are undoubtedly the most flexible ones. They also are efficient discharges since very little HF power is lost in the impedance matching circuit. Finally, a major future avenue for these discharges is their operation as magnetized plasmas. As a first approach to presenting surface wave (SW) plasma sources, let us consider their distinctive features with respect to the other plasma sources described in the book:o1. The discharge can be sustained far away from the active zone of the field applicator. This is because the electric field supporting the discharge is provided by a wave that carries away the power from the applicator. It is an electromagnetic surface wave whose sole guiding structure is the plasma column that it sustains and the dielectric tube enclosing it [1]–[3]. This is, thus, a non-cumbersome method for producing long plasma columns; plasma columns up to 6 meters in length have been achieved in our laboratory while launching the wave with a field applicator that surrounded the discharge tube over a few centimeters in length only. [4][5] 2. The range of the applied field frequency f=?/2? is the broadest of all kinds of high frequency (HF) sustained plasma sources. We have succeeded in realizing HF power transfer to the discharge efficiently from approximately 10 \\{MHz\\} to 10 \\{GHz\\} [6] and, with impaired coupling efficiency, down to 200 kHz [7]. This frequency range includes radiofrequencies (RF) and the lower part of the microwave frequency spectrum; we use the term high frequencies to designate RF as well as microwave frequencies. An interesting aspect of this frequency flexibility is the possibility of acting on the electron energy distribution function (EEDF) to optimize a given plasma process [8]. 3. The gas pressure range is extremely large. On the one hand, one can operate SW discharges in the sub-mtorr range under electron cyclotron resonance (ECR) conditions, [9] while, on the other hand, it is possible to sustain a stable plasma of a few millimeters diameter at pressures at least a few times atmospheric pressure [10]. 4. The range of plasma, density, n, is very large. At reduced pressure and with f in the few \\{MHz\\} range, n, can be as low as 108 cm?3, [7] while at atmospheric pressure it can exceed 1015 cm?3[10] A related parameter is the degree of ionization ?i, i.e. the plasma density relative to the initial neutral atom concentration. Under ECR conditions, for example with f=2.45 \\{GHz\\} where n can reach up to a few 1012 cm?3, ?i ranges approximately from 0.1–10%, whereas in the above-mentioned atmospheric pressure case, it is smaller than 10?4. The higher n, the higher the rate of plasma processes depending on ions or on neutral particles (e.g., atoms, radicals) when the latter are obtained through electron collisions [8]. Large ?i values favor the existence of

Michel Moisan; Joëlle Margot; Zenon Zakrzewski

1996-01-01T23:59:59.000Z

312

Studying fast wave propagation and absorption at any cyclotron harmonic using a 2D finite element area coordinates wave equation solver  

SciTech Connect

Fourier analysis in the poloidal direction is a standard ingredient in present-day 2D wave equation solvers describing radio frequency waves in hot tokamak plasmas. Although a powerful and elegant technique, Fourier analysis has the disadvantage that a large number of modes is needed to describe the field pattern on a magnetic surface if a short wavelength mode exists on any - even very small - subpart of the particle trajectory. The present paper examines the potential of a method that does not suffer from this drawback: a finite element technique relying on simple linear or cubic area base functions that are defined on irregular elementary surfaces of triangular shape. The wave equation is solved in its weak Galerkin variational form and for realistic 2D tokamak geometry, accounting for the toroidal curvature but assuming the toroidal angle is ignorable, allowing to study the wave pattern for each of the independent toroidal modes excited by the antenna individually.The locally uniform full hot plasma dielectric tensor to all orders in finite Larmor radius was adopted. As the main intended application is the study of fast wave behavior (heating and current drive) at arbitrary harmonics, the wave vector complex amplitude appearing in the dielectric tensor is determined through a local dispersion root evaluation. High frequency fast wave propagation and damping is provided as an illustration in view of possible application of this type of current drive in future high density reactor-like tokamaks.

Lerche, Ernesto; Van Eester, Dirk [LPP-ERM/KMS, Association Euratom-'Belgian State', TEC Partner, Brussels (Belgium)

2011-12-23T23:59:59.000Z

313

Ultra high vacuum broad band high power microwave window  

DOE Patents (OSTI)

An improved high vacuum microwave window has been developed that utilizes high density polyethylene coated on two sides with SiOx, SiNx, or a combination of the two. The resultant low dielectric and low loss tangent window creates a low outgassing, low permeation seal through which broad band, high power microwave energy may be passed. No matching device is necessary and the sealing technique is simple. The features of the window are broad band transmission, ultra-high vacuum compatibility with a simple sealing technique, low voltage standing wave ratio, high power transmission and low cost.

Nguyen-Tuong, Viet (Seaford, VA); Dylla, III, Henry Frederick (Yorktown, VA)

1997-01-01T23:59:59.000Z

314

Ultra high vacuum broad band high power microwave window  

DOE Patents (OSTI)

An improved high vacuum microwave window has been developed that utilizes high density polyethylene coated on two sides with SiOx, SiNx, or a combination of the two. The resultant low dielectric and low loss tangent window creates a low outgassing, low permeation seal through which broad band, high power microwave energy may be passed. No matching device is necessary and the sealing technique is simple. The features of the window are broad band transmission, ultra-high vacuum compatibility with a simple sealing technique, low voltage standing wave ratio, high power transmission and low cost. 5 figs.

Nguyen-Tuong, V.; Dylla, H.F. III

1997-11-04T23:59:59.000Z

315

The Cosmic Microwave Background: Beyond the Power Spectrum  

E-Print Network (OSTI)

Much recent work on the cosmic microwave background (CMB) has focussed on the angular power spectrum of temperature anisotropies and particularly on the recovery of cosmological parameters from acoustic peaks in the power spectrum. However, there is more that can conceivably be done with CMB measurements. Here I briefly survey a few such ideas: cross-correlation with other cosmic backgrounds as a probe of the density of the Universe; CMB polarization as a gravitational-wave detector; secondary anisotropies and the ionization history of the Universe; tests of alternative-gravity theories; polarization, the Sunyaev-Zeldovich effect, and cosmic variance; and tests for a neutrino mass.

Marc Kamionkowski

1998-09-24T23:59:59.000Z

316

The Power of People  

Science Journals Connector (OSTI)

The Power of People ... Once, about 20 years ago, I was swimming in the ocean along North Carolina's Outer Banks when an innocent-looking wave wiped me out. ...

MADELEINE JACOBS

1996-03-18T23:59:59.000Z

317

CONTROL OF POPULATION DENSITIES SURROUNDING NUCLEAR POWER PLANTS. VOLUME 5 OF THE FINAL REPORT ON HEALTH AND SAFETY IMPACTS OF NUCLEAR, GEOTHERMAL, AND FOSSIL-FUEL ELECTRIC GENERATION IN CALIFORNIA  

E-Print Network (OSTI)

Response Planning for Nuclear Power Plants in California",and Related Standards for Nuclear Power Plants", Lawrencejected lifetime for a nuclear power plant is 40 years, a

Nero, jA.V.

2010-01-01T23:59:59.000Z

318

Traveling wave device for combining or splitting symmetric and asymmetric waves  

DOE Patents (OSTI)

A traveling wave device for the combining or splitting of symmetric and asymmetric traveling wave energy includes a feed waveguide for traveling wave energy, the feed waveguide having an input port and a launching port, a reflector for coupling wave energy between the feed waveguide and a final waveguide for the collection and transport of wave energy to or from the reflector. The power combiner has a launching port for symmetrical waves which includes a cylindrical section coaxial to the feed waveguide, and a launching port for asymmetric waves which includes a sawtooth rotated about a central axis.

Möbius, Arnold (Eggenstein, DE); Ives, Robert Lawrence (Saratoga, CA)

2005-07-19T23:59:59.000Z

319

Gravity Waves in the Sun  

E-Print Network (OSTI)

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

Tamara M. Rogers; Gary A. Glatzmaier

2005-08-25T23:59:59.000Z

320

Theory of heating of hot magnetized plasma by Alfven waves. Application for solar corona  

E-Print Network (OSTI)

The heating of magnetized plasma by propagation of Alfven waves is calculated as a function of the magnetic field spectral density. The results can be applied to evaluate the heating power of the solar corona at known data from satellites' magnetometers. This heating rate can be incorporated in global models for heating of the solar corona and creation of the solar wind. The final formula for the heating power is illustrated with a model spectral density of the magnetic field obtained by analysis of the Voyager 1 mission results. The influence of high frequency dissipative modes is also taken into account and it is concluded that for evaluation of the total coronal heating it is necessary to know the spectral density of the fluctuating component of the magnetic field up to the frequency of electron-proton collisions.

T. M. Mishonov; M. V. Stoev; Y. G. Maneva

2007-01-19T23:59:59.000Z

Note: This page contains sample records for the topic "wave power density" 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

Modification of ordinary-mode reflectometry system to detect lower-hybrid waves in Alcator C-Mod  

SciTech Connect

Backscattering experiments to detect lower-hybrid (LH) waves have been performed in Alcator C-Mod, using the two modified channels (60 GHz and 75 GHz) of an ordinary-mode reflectometry system with newly developed spectral recorders that can continuously monitor spectral power at a target frequency. The change in the baseline of the spectral recorder during the LH wave injection is highly correlated to the strength of the X-mode non-thermal electron cyclotron emission. In high density plasmas where an anomalous drop in the lower hybrid current drive efficiency is observed, the observed backscattered signals are expected to be generated near the last closed flux surface, demonstrating the presence of LH waves within the plasma. This experimental technique can be useful in identifying spatially localized LH electric fields in the periphery of high-density plasmas.

Baek, S. G.; Shiraiwa, S.; Parker, R. R.; Dominguez, A.; Marmar, E. S. [Plasma Science and Fusion Center, MIT, Cambridge, Massachusetts 02139 (United States); Kramer, G. J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2012-10-15T23:59:59.000Z

322

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

323

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

324

Nearshore oscillating wave surge converters and the development of Oyster  

Science Journals Connector (OSTI)

...dramatically less than that offshore. It is true that the...power converters in wave farms with an economic cap...10-20% lower than that offshore-[9]. In 2002, the...power available to a wave farm. Unlike wind farms, wave energy converters...

2012-01-01T23:59:59.000Z

325

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

326

High Power Density Integrated Traction Machine Drive  

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

2011 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation

327

High Energy Density Capacitors  

SciTech Connect

BEEST Project: Recapping is developing a capacitor that could rival the energy storage potential and price of today’s best EV batteries. When power is needed, the capacitor rapidly releases its stored energy, similar to lightning being discharged from a cloud. Capacitors are an ideal substitute for batteries if their energy storage capacity can be improved. Recapping is addressing storage capacity by experimenting with the material that separates the positive and negative electrodes of its capacitors. These separators could significantly improve the energy density of electrochemical devices.

None

2010-07-01T23:59:59.000Z

328

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.,

329

First Plasma Wave Observations at Neptune  

Science Journals Connector (OSTI)

...revealed that Neptune has a large and complex magnetosphere...first observations of plasma waves and low-frequency...from lightning. Such large dispersions would require path lengths and plasma densities that are much larger than anything plausible...

D. A. Gurnett; W. S. Kurth; R. L. Poynter; L. J. Granroth; I. H. Cairns; W. M. Macek; S. L. Moses; F. V. Coroniti; C. F. Kennel; D. D. Barbosa

1989-12-15T23:59:59.000Z

330

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

331

Nonlinear interaction of proton whistler with kinetic Alfvén wave to study solar wind turbulence  

SciTech Connect

This paper presents the nonlinear interaction between small but finite amplitude kinetic Alfvén wave (KAW) and proton whistler wave using two-fluid model in intermediate beta plasma, applicable to solar wind. The nonlinearity is introduced by modification in the background density. This change in density is attributed to the nonlinear ponderomotive force due to KAW. The solutions of the model equations, governing the nonlinear interaction (and its effect on the formation of localized structures), have been obtained using semi-analytical method in solar wind at 1AU. It is concluded that the KAW properties significantly affect the threshold field required for the filament formation and their critical size (for proton whistler). The magnetic and electric field power spectra have been obtained and their relevance with the recent observations of solar wind turbulence by Cluster spacecraft has been pointed out.

Goyal, R.; Sharma, R. P. [Centre for Energy Studies, Indian Institute of Technology, Delhi-110016 (India)] [Centre for Energy Studies, Indian Institute of Technology, Delhi-110016 (India); Goldstein, M. L. [NASA Goddard Space Flight Centre, Code 673, Greenbelt, Maryland 20771 (United States)] [NASA Goddard Space Flight Centre, Code 673, Greenbelt, Maryland 20771 (United States); Dwivedi, N. K. [Austrian Academy of Sciences, Space Research Institute, Schmiedlstrasse 6, 8042 Graz (Austria)] [Austrian Academy of Sciences, Space Research Institute, Schmiedlstrasse 6, 8042 Graz (Austria)

2013-12-15T23:59:59.000Z

332

Topic 5: Renewable Power 1Networking and Distributed Systems  

E-Print Network (OSTI)

Communications and Control in Smart Grid 10 · Wave power is the energy from ocean surface waves. · Orbital motion the device to the ocean floor to hold it. cable Power modules Tubular section #12;Wave Energy Converter DrTopic 5: Renewable Power 1Networking and Distributed Systems Department of Electrical & Computer

Mohsenian-Rad, Hamed

333

Solar coronal heating by magnetosonic waves  

Science Journals Connector (OSTI)

......presence of MHD waves in the solar corona. Saba Strong...data acquired by the Solar Maximum Mission (SMM...emission lines came the SOHO project (Doyle, Teriaca Banerjee...calculated the Alfven wave energy flux density as for...and a combination of Solar Untraviolet Measurements......

E. R. Pekünlü; Ö. Çakirli; E. Özetken

2001-09-11T23:59:59.000Z

334

On the Energy of Rotating Gravitational Waves  

E-Print Network (OSTI)

A class of solutions of the gravitational field equations describing vacuum spacetimes outside rotating cylindrical sources is presented. A subclass of these solutions corresponds to the exterior gravitational fields of rotating cylindrical systems that emit gravitational radiation. The properties of these rotating gravitational wave spacetimes are investigated. In particular, we discuss the energy density of these waves using the gravitational stress-energy tensor.

Bahram Mashhoon; James C. McClune; Enrique Chavez; Hernando Quevedo

1996-09-06T23:59:59.000Z

335

Characterisation of SOL density fluctuations in front of the LHCD PAM launcher in Tore  

SciTech Connect

The density fluctuations, modified by Lower Hybrid Wave (LHW), is analyzed in Tore Supra with reference to the injected LHW power, density and the gap between LCFS (Last Closed Flux Surface) and the PAM (passive-active-multijunction) launcher. The density fluctuations are measured with RF probes installed at the PAM launcher front. A density scan at nominal toroidal field (3.8 T) shows that the fluctuations rate stays nearly constant ({approx}50%) for <3.5x10{sup 19}m{sup -3} and with LHW power up to 2MW. However, when increasing the density above <{approx}4.2x10{sup 19}m{sup -3}, using strong gas puffing, the fluctuation rate increases to >70% and is characterized by strong negative spikes, with typical frequency >100kHz. These are most likely originating from acceleration of electrons in the LHW near field due to parasitic absorption, as evidenced on the IR images, showing hot spots on the side limiters.

Oosako, T.; Ekedahl, A.; Goniche, M.; Achard, J.; Decker, J.; Peysson, Y. [CEA, IRFM, F-13108 Saint Paul-lez-Durance (France)

2011-12-23T23:59:59.000Z

336

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

337

Data Center Power Consumption  

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

Center Power Consumption Center Power Consumption A new look at a growing problem Fact - Data center power density up 10x in the last 10 years 2.1 kW/rack (1992); 14 kW/rack (2007) Racks are not fully populated due to power/cooling constraints Fact - Increasing processor power Moore's law Fact - Energy cost going up 3 yr. energy cost equivalent to acquisition cost Fact - Iterative power life cycle Takes as much energy to cool computers as it takes to power them. Fact - Over-provisioning Most data centers are over-provisioned with cooling and still have hot spots November 2007 SubZero Engineering An Industry at the Crossroads Conflict between scaling IT demands and energy efficiency Server Efficiency is improving year after year Performance/Watt doubles every 2 years Power Density is Going Up

338

High power density propulsion/power system for underwater applications  

SciTech Connect

This patent describes a drive system for an underwater vehicle utilizing open Rankine thermodynamic cycle system having water as working fluid; steam generation means for receiving the working fluid and converting the working fluid to steam; an energy converter adapted to receive the steam and drive a propulsion means; a mixing condenser adapted to receive the steam exits the energy converter and condense the steam to a liquid; means for introducing water into the mixing condensers from a source external to the Rankine cycle, the water mixing with the working fluid to form mixed work fluid.

Blau, A.

1992-06-02T23:59:59.000Z

339

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

340

Rotordynamics in alternative energy power generation.  

E-Print Network (OSTI)

??This thesis analyses and discusses the main alternative energy systems that work with rotordynamics machines to generate power. Hydropower systems, wave and ocean energy, geothermal,… (more)

Cortes-Zambrano, Ivan

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "wave power density" 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

Author's personal copy Wave energy resources along the Hawaiian Island chain  

E-Print Network (OSTI)

Author's personal copy Wave energy resources along the Hawaiian Island chain Justin E. Stopa model Wave atlas Wave energy Wave power a b s t r a c t Hawaii's access to the ocean and remoteness from demand for sustainable energy. The wave resources include swells from distant storms and year-round seas

342

Peculiarities in the energy transfer by waves on strained strings  

E-Print Network (OSTI)

Peculiarities in the energy transfer by waves on strained strings Eugene I. Butikov St. Petersburg of elastic potential energy associated with waves in a stretched string is discussed. The influence of nonlinear coupling between transverse and longitudinal waves on the density of energy is investigated

Butikov, Eugene

343

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

344

MHK Technologies/New Knowledge Wind and Wave Renewable Mobile Wind and Wave  

Open Energy Info (EERE)

Wind and Wave Renewable Mobile Wind and Wave Wind and Wave Renewable Mobile Wind and Wave Power Plant Platform < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage New Knowledge Wind and Wave Renewable Mobile Wind and Wave Power Plant Platform.jpg Technology Profile Primary Organization Darrel Dammen Technology Resource Click here Wave Technology Description Buoyant vessel attached to a lever the lever being attached to a stationary source like near shore Oil Rigs docks or a vessel less affected by swells and waves like large ships floating Oil rigs or boats the levers going up and down creates a torque at the pivot point by the vessel being raised and lowered this works on all size levers making it possible to collect energy from all size Waves with enough levers with in reasonable size and numbers the force can be used hydraulically mechanically or to compress air to power generators Ten tons going up and down is a lot of force when connected to a 100 so connecting to 100 tons then to 50 tons then to 25 tons then to 10 tons to 5 tons to 2 tons continuing down in size and multiplying the levers from the less affected floating object or stationary object will mean We collect energy from 1 foot to 100 foot waves and swells This Wind and Wave with 120 oarsmen showing buoyant vessels are the oarsman in this picture with hund

345

Decays of electron Bernstein waves near plasma edge  

SciTech Connect

Nonlinear wave-wave couplings near the upper hybrid resonance are studied via particle-in-cell simulations. It is found that the decay of an electron Bernstein wave (EBW) depends on the ratio of the incident frequency and electron cyclotron frequency. For ratios less than two, parametric decay into a lower hybrid wave (or an ion Bernstein wave) and EBWs at a lower frequency is observed. For ratios larger than two, the daughter waves could be an electron cyclotron quasi-mode and another EBW or an ion wave and EBW. For sufficiently high incident power, the former process may dominate. Because of the electron cyclotron quasi-mode, electrons can be strongly heated by nonlinear Landau damping. As a result, the bulk of the incident power can be absorbed near plasma edge at high power. The increase in number of decay channels with frequency implies that the allowable power into the plasma must decrease with frequency.

Xiang Nong [Institute of Plasma Physics, CAS, Hefei, Anhui 230031 (China); Center for Integrated Plasma Studies, University of Colorado at Boulder, Boulder, Colorado 80309 (United States); Cary, John R. [Center for Integrated Plasma Studies, University of Colorado at Boulder, Boulder, Colorado 80309 (United States); Tech-X Corporation, Boulder, Colorado 80303 (United States)

2011-12-15T23:59:59.000Z

346

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

347

Superconducting travelling wave ring with high gradient accelerating section  

SciTech Connect

Use of a superconducting traveling wave accelerating (STWA) structure instead of a standing wave cavity has major advantages in increasing the accelerating gradient in the ILC. In contrast with standing wave cavity STWA requires feedback loop, which sends wave from the structure output to input, making a superconducting traveling wave ring (STWR). One or few input couplers need to excite STWR and compensate power dissipations due to beam loading. To control traveling wave regime in the structure two independent knobs can be used for tuning both resonant ring frequency and backward wave. We discuss two variants of the STWR with one and two feed couplers.

Avrakhov, P.; Solyak, N.; /Fermilab

2007-06-01T23:59:59.000Z

348

The dynamics of variable-density turbulence  

SciTech Connect

The dynamics of variable-density turbulent fluids are studied by direct numerical simulation. The flow is incompressible so that acoustic waves are decoupled from the problem, and implying that density is not a thermodynamic variable. Changes in density occur due to molecular mixing. The velocity field, is in general, divergent. A pseudo-spectral numerical technique is used to solve the equations of motion. Three-dimensional simulations are performed using a grid size of 128{sup 3} grid points. Two types of problems are studied: (1) the decay of isotropic, variable-density turbulence, and (2) buoyancy-generated turbulence in a fluid with large density fluctuations. In the case of isotropic, variable-density turbulence, the overall statistical decay behavior, for the cases studied, is relatively unaffected by the presence of density variations when the initial density and velocity fields are statistically independent. The results for this case are in quantitative agreement with previous numerical and laboratory results. In this case, the initial density field has a bimodal probability density function (pdf) which evolves in time towards a Gaussian distribution. The pdf of the density field is symmetric about its mean value throughout its evolution. If the initial velocity and density fields are statistically dependent, however, the decay process is significantly affected by the density fluctuations. For the case of buoyancy-generated turbulence, variable-density departures from the Boussinesq approximation are studied. The results of the buoyancy-generated turbulence are compared with variable-density model predictions. Both a one-point (engineering) model and a two-point (spectral) model are tested against the numerical data. Some deficiencies in these variable-density models are discussed and modifications are suggested.

Sandoval, D.L.

1995-11-01T23:59:59.000Z

349

Conditions for supersonic bent Marshak waves  

E-Print Network (OSTI)

Supersonic radiation diffusion approximation is a useful way to study the radiation transportation. Considering the bent Marshak wave theory in 2-dimensions, and an invariable source temperature, we get the supersonic radiation diffusion conditions which are about the Mach number $M>8(1+\\sqrt{\\ep})/3$, and the optical depth $\\tau>1$. A large Mach number requires a high temperature, while a large optical depth requires a low temperature. Only when the source temperature is in a proper region these conditions can be satisfied. Assuming the material opacity and the specific internal energy depend on the temperature and the density as a form of power law, for a given density, these conditions correspond to a region about source temperature and the length of the sample. This supersonic diffusion region involves both lower and upper limit of source temperature, while that in 1-dimension only gives a lower limit. Taking $\\rm SiO_2$ and the Au for example, we show the supersonic region numerically.

Xu, Qiang; Li, Jing; Dan, Jia-kun; Wang, Kun-lun; Zhou, Shao-tong

2014-01-01T23:59:59.000Z

350

Directional Spectra of Wind-Generated Waves  

Science Journals Connector (OSTI)

...H. Hui From observations of wind and of water surface elevation...the directional spectrum of wind-generated waves on deep water...inversely proportional to the fourth power of the frequency , with the...clearly dependent on the ratio of wind speed to peak wave speed...

1985-01-01T23:59:59.000Z

351

Emergence of exponentially small reflected waves  

E-Print Network (OSTI)

We study the time-dependent scattering of a quantum mechanical wave packet at a barrier for energies larger than the barrier height, in the semi-classical regime. More precisely, we are interested in the leading order of the exponentially small scattered part of the wave packet in the semiclassical parameter when the energy density of the incident wave is sharply peaked around some value. We prove that this reflected part has, to leading order, a Gaussian shape centered on the classical trajectory for all times soon after its birth time. We give explicit formulas and rigorous error bounds for the reflected wave for all of these times.

Volker Betz; Alain Joye; Stefan Teufel

2008-04-23T23:59:59.000Z

352

E-Print Network 3.0 - absorbing column densities Sample Search...  

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

John - National Radio Astronomy Observatory Collection: Physics 3 Characteristics and energy balance of a plasma column sustained by a surface wave Summary: density distribution...

353

Generalized time-dependent density-functional-theory response functions for spontaneous density fluctuations and nonlinear response: Resolving the causality paradox in real time  

E-Print Network (OSTI)

Generalized time-dependent density-functional-theory response functions for spontaneous density shifted the focus of elec- tronic structure theory from the many-body wave function to the charge density response and spontaneous fluctuations of many-electron systems. The pth-order density response functions

Mukamel, Shaul

354

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

355

Power Plant Power Plant  

E-Print Network (OSTI)

Basin Center for Geothermal Energy at University of Nevada, Reno (UNR) 2 Nevada Geodetic LaboratoryStillwater Power Plant Wabuska Power Plant Casa Diablo Power Plant Glass Mountain Geothermal Area Lassen Geothermal Area Coso Hot Springs Power Plants Lake City Geothermal Area Thermo Geothermal Area

Tingley, Joseph V.

356

The dynamics of variable-density turbulence  

SciTech Connect

The dynamics of variable-density turbulent fluids are studied by direct numerical simulation. The flow is incompressible so that acoustic waves are decoupled from the problem, and implying that density is not a thermodynamic variable. Changes in density occur due to molecular mixing. The velocity field is, in general, divergent. A pseudo-spectral numerical technique is used to solve the equations of motion. Three-dimensional simulations are performed using a grid size of 128{sup 3} grid points. Two types of problems are studied: (1) the decay of isotropic, variable-density turbulence, and (2) buoyancy-generated turbulence in a fluid with large density fluctuations (such that the Boussinesq approximation is not valid). In the case of isotropic, variable-density turbulence, the overall statistical decay behavior, for the cases studied, is relatively unaffected by the presence of density variations when the initial density and velocity fields are statistically independent. The results for this case are in quantitative agreement with previous numerical and laboratory results. In this case, the initial density field has a bimodal probability density function (pdf) which evolves in time towards a Gaussian distribution. The pdf of the density field is symmetric about its mean value throughout its evolution. If the initial velocity and density fields are statistically dependent, however, the decay process is significantly affected by the density fluctuations. For this case, the pdf of the density becomes asymmetric about its mean value during the early stages of its evolution. It is argued that these asymmetries in the pdf of the density field are due to different entrainment rates, into the mixing region, that favor the high speed fluid.

Sandoval, D.L.

1995-11-01T23:59:59.000Z

357

Viscous damping of Alfven surface waves in the solar atmosphere  

SciTech Connect

The dispersion relation for the propagation of viscous Alfven surface waves along viscous plasmaplasma interface has been derived. Two modes of Alfven surface waves are found to propagate with their characteristics depend on the interface parameters like magnetic field, density ratio, viscosity, etc. The viscous damping of Alfven surface waves has been studied in the astrophysical point of view. The damping length of Alfven surface waves due to viscosity in the solar atmosphere has been estimated.

Rathinavelu, G. D.; Sivaraman, M. [Gandhigram Rural University, Plasma Physics Group, Department of Physics (India); Narayanan, A. S. [Indian Institute of Astrophysics (India)

2009-11-15T23:59:59.000Z

358

Heating and Non-thermal Particle Acceleration in Relativistic, Transverse Magnetosonic Shock Waves in Proton-Electron-Positron Plasmas  

E-Print Network (OSTI)

We report the results of 1D particle-in-cell simulations of ultrarelativistic shock waves in proton-electron-positron plasmas. We consider magnetized shock waves, in which the upstream medium carries a large scale magnetic field, directed transverse to the flow. Relativistic cyclotron instability of each species as the incoming particles encounter the increasing magnetic field within the shock front provides the basic plasma heating mechanism. The most significant new results come from simulations with mass ratio $m_p/m_\\pm = 100$. We show that if the protons provide a sufficiently large fraction of the upstream flow energy density (including particle kinetic energy and Poynting flux), a substantial fraction of the shock heating goes into the formation of suprathermal power-law spectra of pairs. Cyclotron absorption by the pairs of the high harmonic ion cyclotron waves, emitted by the protons, provides the non-thermal acceleration mechanism. As the proton fraction increases, the non-thermal efficiency increases and the pairs' power-law spectra harden. We suggest that the varying power law spectra observed in synchrotron sources powered by magnetized winds and jets might reflect the correlation of the proton to pair content enforced by the underlying electrodynamics of these sources' outflows, and that the observed correlation between the X-ray spectra of rotation powered pulsars with the X-ray spectra of their nebulae might reflect the same correlation.

Elena Amato; Jonathan Arons

2006-09-01T23:59:59.000Z

359

Power Factor Reactive Power  

E-Print Network (OSTI)

power: 130 watts Induction motor PSERC Incandescent lights 0 0.002 0.004 0.006 0.008 0.01 0.012 0.014 0 power: 150 watts #12;Page 4 PSERC Incandescent Lights PSERC Induction motor with no load #12;Page 5 Incandescent Lights #12;Page 7 PSERC Incandescent lights power: Power = 118 V x 1.3 A = 153 W = 0.15 kW = power

360

Zero Energy of Plane-Waves for ELKOs  

E-Print Network (OSTI)

We consider the ELKO field in interaction through contorsion with its own spin density, and we investigate the form of the consequent autointeractions; to do so we take into account the high-density limit and find plane wave solutions: such plane waves give rise to contorsional autointeractions for which the Ricci metric curvature vanishes and therefore the energy density is equal to zero identically. Consequences are discussed.

Luca Fabbri

2011-02-23T23:59:59.000Z

Note: This page contains sample records for the topic "wave power density" 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 KINETIC MODEL OF SOLAR WIND GENERATION BY OBLIQUE ION-CYCLOTRON WAVES  

SciTech Connect

The fast solar wind is generated by extended perpendicular ion heating in coronal holes, but the kinetic mechanism responsible for this heating has not been determined. One long-standing possibility is the resonant-cyclotron dissipation of ion-cyclotron waves, replenished from a turbulent cascade of interacting counter-propagating Alfven waves. We present results of a kinetic model for proton heating by the quasilinear resonant-cyclotron wave-particle interaction in a coronal hole. The resonant wave spectrum is taken as a power law in wavenumber, uniformly distributed in propagation direction between 0 deg. and 60 deg. with respect to the large-scale radial magnetic field. We obtain the steady-state solution of the kinetic guiding-center equation for the proton distribution in an expanding coronal hole, including the effects of large-scale forces of gravity, charge-separation electric field, Alfven wave ponderomotive force, and mirror force, along with the small-scale scattering from the wave dissipation. We find that plausible wave intensities can yield reasonable flow speeds and temperatures in the heliocentric radial range between 2 and 6 solar radii. We address the claim in earlier work that dissipation of parallel-propagating ion-cyclotron waves cannot provide enough acceleration and show that claim to be incorrect. We find that the combined action of the large-scale forces and the resonant-cyclotron scattering produces proton distribution functions with a characteristic structure: compressed in the sunward half of velocity space with a high-density shell separate from the origin, and relatively expanded in the anti-sunward half of velocity space. We suggest that qualitatively similar proton distributions would result from the kinetic evolution of any sufficiently effective perpendicular heating mechanism operating in an expanding coronal hole.

Isenberg, Philip A.; Vasquez, Bernard J. [Institute for the Study of Earth, Oceans and Space and Department of Physics, University of New Hampshire, Durham, NH 03824 (United States)

2011-04-20T23:59:59.000Z

362

Nonlinear coupling of left and right handed circularly polarized dispersive Alfvén wave  

SciTech Connect

The nonlinear phenomena are of prominent interests in understanding the particle acceleration and transportation in the interplanetary space. The ponderomotive nonlinearity causing the filamentation of the parallel propagating circularly polarized dispersive Alfvén wave having a finite frequency may be one of the mechanisms that contribute to the heating of the plasmas. The contribution will be different of the left (L) handed mode, the right (R) handed mode, and the mix mode. The contribution also depends upon the finite frequency of the circularly polarized waves. In the present paper, we have investigated the effect of the nonlinear coupling of the L and R circularly polarized dispersive Alfvén wave on the localized structures formation and the respective power spectra. The dynamical equations are derived in the presence of the ponderomotive nonlinearity of the L and R pumps and then studied semi-analytically as well as numerically. The ponderomotive nonlinearity accounts for the nonlinear coupling between both the modes. In the presence of the adiabatic response of the density fluctuations, the nonlinear dynamical equations satisfy the modified nonlinear Schrödinger equation. The equations thus obtained are solved in solar wind regime to study the coupling effect on localization and the power spectra. The effect of coupling is also studied on Faraday rotation and ellipticity of the wave caused due to the difference in the localization of the left and the right modes with the distance of propagation.

Sharma, R. P., E-mail: rpsharma@ces.iitd.ac.in; Sharma, Swati, E-mail: swati.sharma704@gmail.com; Gaur, Nidhi, E-mail: nidhiphysics@gmail.com [Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi 110016 (India)

2014-07-15T23:59:59.000Z

363

Modelling and geometry optimisation of wave energy converters  

E-Print Network (OSTI)

Modelling and geometry optimisation of wave energy converters Adi Kurniawan Supervisors: Prof DIY Riding radical wave power" #12;#12;Any device will deliver some energyAny device will deliver some energy #12;What matters is the cost of energy Ultimate problem Given the waves, design a device

Nørvåg, Kjetil

364

Structural power flow measurement  

SciTech Connect

Previous investigations of structural power flow through beam-like structures resulted in some unexplained anomalies in the calculated data. In order to develop structural power flow measurement as a viable technique for machine tool design, the causes of these anomalies needed to be found. Once found, techniques for eliminating the errors could be developed. Error sources were found in the experimental apparatus itself as well as in the instrumentation. Although flexural waves are the carriers of power in the experimental apparatus, at some frequencies longitudinal waves were excited which were picked up by the accelerometers and altered power measurements. Errors were found in the phase and gain response of the sensors and amplifiers used for measurement. A transfer function correction technique was employed to compensate for these instrumentation errors.

Falter, K.J.; Keltie, R.F.

1988-12-01T23:59:59.000Z

365

Harvesting Broadband Kinetic Impact Energy from Mechanical Triggering/Vibration and Water Waves  

Science Journals Connector (OSTI)

(13) Although efforts in utilizing ocean wave energy could be dated back to 1890,(13) there has not been any commercial wave power farms up to now. ... This demonstrates that in addition to water wave energy harvesting our TENG also has the potential for hydrological analysis, which is a very important function for a wave energy farming system. ... Last but not least, the major component for ocean wave harvesting is the offshore wind power. ...

Xiaonan Wen; Weiqing Yang; Qingshen Jing; Zhong Lin Wang

2014-06-25T23:59:59.000Z

366

2D modeling of electromagnetic waves in cold plasmas  

SciTech Connect

The consequences of sheath (rectified) electric fields, resulting from the different mobility of electrons and ions as a response to radio frequency (RF) fields, are a concern for RF antenna design as it can cause damage to antenna parts, limiters and other in-vessel components. As a first step to a more complete description, the usual cold plasma dielectric description has been adopted, and the density profile was assumed to be known as input. Ultimately, the relevant equations describing the wave-particle interaction both on the fast and slow timescale will need to be tackled but prior to doing so was felt as a necessity to get a feeling of the wave dynamics involved. Maxwell's equations are solved for a cold plasma in a 2D antenna box with strongly varying density profiles crossing also lower hybrid and ion-ion hybrid resonance layers. Numerical modelling quickly becomes demanding on computer power, since a fine grid spacing is required to capture the small wavelengths effects of strongly evanescent modes.

Crombé, K. [Laboratory for Plasma Physics, Association EURATOM - Belgian State Trilateral Euregio Cluster, Renaissancelaan 30 Avenue de la Renaissance, B-1000 Brussels, Belgium and Department of Applied Physics, Ghent University, Sint-Pietersnieuwstraat 41 B4, B (Belgium); Van Eester, D.; Koch, R.; Kyrytsya, V. [Laboratory for Plasma Physics, Association EURATOM - Belgian State Trilateral Euregio Cluster, Renaissancelaan 30 Avenue de la Renaissance, B-1000 Brussels (Belgium)

2014-02-12T23:59:59.000Z

367

Whistler mode waves and the electron heat flux in the solar wind: Cluster observations  

E-Print Network (OSTI)

The nature of the magnetic field fluctuations in the solar wind between the ion and electron scales is still under debate. Using the Cluster/STAFF instrument, we make a survey of the power spectral density and of the polarization of these fluctuations at frequencies $f\\in[1,400]$ Hz, during five years (2001-2005), when Cluster was in the free solar wind. In $\\sim 10\\%$ of the selected data, we observe narrow-band, right-handed, circularly polarized fluctuations, with wave vectors quasi-parallel to the mean magnetic field, superimposed on the spectrum of the permanent background turbulence. We interpret these coherent fluctuations as whistler mode waves. The life time of these waves varies between a few seconds and several hours. Here we present, for the first time, an analysis of long-lived whistler waves, i.e. lasting more than five minutes. We find several necessary (but not sufficient) conditions for the observation of whistler waves, mainly a low level of the background turbulence, a slow wind, a relative...

Lacombe, Catherine; Matteini, Lorenzo; Santolik, Ondrej; Cornilleau-Wehrlin, Nicole; Mangeney, Andre; de Conchy, Yvonne; Maksimovic, Milan

2014-01-01T23:59:59.000Z

368

Design of far-infrared three-wave polarimeter-interferometer system for the J-TEXT tokamak  

SciTech Connect

A multichannel three-wave far-infrared polarimeter-interferometer will be constructed on the J-TEXT tokamak (R=1.05 m, a=0.27 m, B{sub T}{<=}3 T, and I{sub P}{<=}350 kA) for current density profile and electron density profile measurements. The system will adopt the three-wave polarimeter configuration which was first introduced on RTP. Three 432.5 {mu}m HCOOH lasers pumped by three CO{sub 2} lasers separately will be adopted, which could generate high output power, nearly 50 mW at each cavity. Two of them will be counter-rotating circularly polarized to probe the Faraday angle, while the third laser will be used as a local oscillator to get the phase shift caused by electron density. Excellent port access (600x76 mm{sup 2}) and high laser power would promise a profile measurement across the whole plasma section with good signal quality. A high-speed digital phase comparator with a few ({approx}2) {mu}s temporal resolution will be developed, so that fast changes of current or density profile could be measured. Six channels will be installed in the first stage.

Chen, J.; Gao, L.; Zhuang, G.; Wang, Z. J. [Institute of Nuclear Fusion and Plasma Physics, College of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China and Key Laboratory of Fusion and Advanced Electromagnetic Technology, Ministry of Education, Wuhan 430074 (China); Gentle, K. W. [Institute of Fusion Studies, University of Texas at Austin, Texas 78712 (United States)

2010-10-15T23:59:59.000Z

369

Time-dependent Density Functional Theory Miguel A. L. Marques and E. K. U. Gross  

E-Print Network (OSTI)

Time-dependent Density Functional Theory Miguel A. L. Marques and E. K. U. Gross 1 Introduction Time-dependent density-functional theory (TDDFT) extends the basic ideas of ground-state density-functional is the one-body electron density, n(r, t). The advantages are clear: The many-body wave-function, a function

Wu, Zhigang

370

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

Science Journals Connector (OSTI)

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

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

1996-01-01T23:59:59.000Z

371

Detonation waves in relativistic hydrodynamics  

Science Journals Connector (OSTI)

This paper is concerned with an algebraic study of the equations of detonation waves in relativistic hydrodynamics taking into account the pressure and the energy of thermal radiation. A new approach to shock and detonation wavefronts is outlined. The fluid under consideration is assumed to be perfect (nonviscous and nonconducting) and to obey the following equation of state: p=(?-1)? where p, ?, and ? are the pressure, the total energy density, and the adiabatic index, respectively. The solutions of the equations of detonation waves are reduced to the problem of finding physically acceptable roots of a quadratic polynomial ?(X) where X is the ratio ?/?0 of dynamical volumes behind and ahead of the detonation wave. The existence and the locations of zeros of this polynomial allow it to be shown that if the equation of state of the burnt fluid is known then the variables characterizing the unburnt fluid obey well-defined physical relations.

Mahdy Cissoko

1992-02-15T23:59:59.000Z

372

ULATION OFPOWERELECTRONICCIRC USED IN WAVE DIGITAL FI  

E-Print Network (OSTI)

mode power supplies already in use in industry. 1. INTRODUCTION Wave digital filters (WDFs) represent Institute for Power Electronics and Electrical Drives University of Paderbom, FB14 Postfach 1621,33098Paderborn, Germany Tel.: ++49 - 5251 -60 3157, FAX: ++49 -5251-60 3443, E-mail: fiedler

Paderborn, Universität

373

Plasma turbulence driven by transversely large-scale standing shear Alfven waves  

SciTech Connect

Using two-dimensional particle-in-cell simulations, we study generation of turbulence consisting of transversely small-scale dispersive Alfven and electrostatic waves when plasma is driven by a large-scale standing shear Alfven wave (LS-SAW). The standing wave is set up by reflecting a propagating LS-SAW. The ponderomotive force of the standing wave generates transversely large-scale density modifications consisting of density cavities and enhancements. The drifts of the charged particles driven by the ponderomotive force and those directly caused by the fields of the standing LS-SAW generate non-thermal features in the plasma. Parametric instabilities driven by the inherent plasma nonlinearities associated with the LS-SAW in combination with the non-thermal features generate small-scale electromagnetic and electrostatic waves, yielding a broad frequency spectrum ranging from below the source frequency of the LS-SAW to ion cyclotron and lower hybrid frequencies and beyond. The power spectrum of the turbulence has peaks at distinct perpendicular wave numbers (k{sub Up-Tack }) lying in the range d{sub e}{sup -1}-6d{sub e}{sup -1}, d{sub e} being the electron inertial length, suggesting non-local parametric decay from small to large k{sub Up-Tack }. The turbulence spectrum encompassing both electromagnetic and electrostatic fluctuations is also broadband in parallel wave number (k{sub ||}). In a standing-wave supported density cavity, the ratio of the perpendicular electric to magnetic field amplitude is R(k{sub Up-Tack }) = |E{sub Up-Tack }(k{sub Up-Tack })/|B{sub Up-Tack }(k{sub Up-Tack })| Much-Less-Than V{sub A} for k{sub Up-Tack }d{sub e} < 0.5, where V{sub A} is the Alfven velocity. The characteristic features of the broadband plasma turbulence are compared with those available from satellite observations in space plasmas.

Singh, Nagendra; Rao, Sathyanarayan [Electrical and Computer Engineering, University of Alabama, Huntsville, Alabama 35899 (United States)

2012-12-15T23:59:59.000Z

374

SeWave | Open Energy Information  

Open Energy Info (EERE)

form form View source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit with form History Facebook icon Twitter icon » SeWave Jump to: navigation, search Name SeWave Place Denmark Zip FO-110 Product Denmark-based 50:50 JV between UK's Wavegen and Faroese electricity company SEV to to design and build a tunnelled demonstration wave power plant in the Faroes Islands. References SeWave[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This company is listed in the Marine and Hydrokinetic Technology Database. This article is a stub. You can help OpenEI by expanding it. SeWave is a company located in Denmark . References ↑ "SeWave"

375

Refrigeration system having standing wave compressor  

DOE Patents (OSTI)

A compression-evaporation refrigeration system, wherein gaseous compression of the refrigerant is provided by a standing wave compressor. The standing wave compressor is modified so as to provide a separate subcooling system for the refrigerant, so that efficiency losses due to flashing are reduced. Subcooling occurs when heat exchange is provided between the refrigerant and a heat pumping surface, which is exposed to the standing acoustic wave within the standing wave compressor. A variable capacity and variable discharge pressure for the standing wave compressor is provided. A control circuit simultaneously varies the capacity and discharge pressure in response to changing operating conditions, thereby maintaining the minimum discharge pressure needed for condensation to occur at any time. Thus, the power consumption of the standing wave compressor is reduced and system efficiency is improved.

Lucas, Timothy S. (Glen Allen, VA)

1992-01-01T23:59:59.000Z

376

Laboratory Density Functionals  

E-Print Network (OSTI)

We compare several definitions of the density of a self-bound system, such as a nucleus, in relation with its center-of-mass zero-point motion. A trivial deconvolution relates the internal density to the density defined in the laboratory frame. This result is useful for the practical definition of density functionals.

B. G. Giraud

2007-07-26T23:59:59.000Z

377

Parametric internal waves in a compressible fluid  

E-Print Network (OSTI)

We describe the effect of vibration on a confined volume of fluid which is density stratified due to its compressibility. We show that internal gravity-acoustic waves can be parametrically destabilized by the vibration. The resulting instability is similar to the classic Faraday instability of surface waves, albeit modified by the compressible nature of the fluid. It may be possible to observe experimentally near a gas-liquid critical point.

Kausik S. Das; Stephen W. Morris; A. Bhattacharyay

2007-10-11T23:59:59.000Z

378

Parametric internal waves in a compressible fluid  

E-Print Network (OSTI)

We describe the effect of vibration on a confined volume of fluid which is density stratified due to its compressibility. We show that internal gravity-acoustic waves can be parametrically destabilized by the vibration. The resulting instability is similar to the classic Faraday instability of surface waves, albeit modified by the compressible nature of the fluid. It may be possible to observe experimentally near a gas-liquid critical point.

Das, Kausik S; Bhattacharyay, A

2007-01-01T23:59:59.000Z

379

Damping of lower hybrid waves in large spectral gap configurations  

SciTech Connect

Extensive experimental data support reliable power deposition and current drive by lower-hybrid (LH) waves in conditions where a large spectral gap exists between the nominal parallel index of refraction prescribed by the antenna characteristics and phasing, and that required for significant Landau damping to take place. We argue that only a significant modification of the initial spectrum at the plasma edge could explain experimental observations. Based on this assumption, a new prescription for reliable simulations of LH current drive using ray-tracing and Fokker-Planck modelling is proposed. A remarkable agreement between experimental observations in the Tore Supra tokamak and simulations is obtained for relevant parametric scans, including electron density and LH waveguide phasing. In an effort to investigate the possible role of fluctuations, it is shown that the spectral gap can be bridged dynamically in the presence of a fluctuating LH spectrum.

Decker, J.; Peysson, Y.; Artaud, J.-F.; Nilsson, E.; Ekedahl, A.; Goniche, M.; Hillairet, J.; Mazon, D. [CEA, IRFM, F-13108 Saint Paul lez Durance (France)

2014-02-12T23:59:59.000Z

380

Particle-Number Projection and the Density Functional Theory  

E-Print Network (OSTI)

In the framework of the Density Functional Theory for superconductors, we study the restoration of the particle number symmetry by means of the projection technique. Conceptual problems are outlined and numerical difficulties are discussed. Both are related to the fact that neither the many-body Hamiltonian nor the wave function of the system appear explicitly in the Density Functional Theory. Similar obstacles are encountered in self-consistent theories utilizing density-dependent effective interactions.

J. Dobaczewski; M. V. Stoitsov; W. Nazarewicz; P. -G. Reinhard

2007-08-03T23:59:59.000Z

Note: This page contains sample records for the topic "wave power density" 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

Unambiguous exchange-correlation energy density Kieron Burke,a)  

E-Print Network (OSTI)

density approximation LDA , the conventional form is eXC unif (r) , the exchange-correlation energy the following definition of an energy density: eXC wave fn. r d3 r P r,r r r 2 r r 1 2 2 r,r s r,r r r , 2 whereUnambiguous exchange-correlation energy density Kieron Burke,a) Federico G. Cruz, and Kin-Chung Lam

Burke, Kieron

382

MHK Technologies/bioWave | Open Energy Information  

Open Energy Info (EERE)

bioWave bioWave < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage BioWave.jpg Technology Profile Primary Organization BioPower Systems Pty Ltd Project(s) where this technology is utilized *MHK Projects/bioWAVE Pilot Plant Technology Resource Click here Wave Technology Type Click here Oscillating Wave Surge Converter Technology Readiness Level Click here TRL 5/6: System Integration and Technology Laboratory Demonstration Technology Description TThe bioWAVE is based on the swaying motion of sea plants in the presence of ocean waves. The hydrodynamic interaction of the buoyant blades with the oscillating flow field is designed for maximum energy absorption. Mooring Configuration Gravity base Optimum Marine/Riverline Conditions 30 to 50M depth 20kW m wave climate or greater

383

Ocean Power Technologies (TRL 5 6 System) - PB500, 500 kW Utility...  

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

technologiesinchart.ppt More Documents & Publications Advanced, High Power, Next Scale, Wave Energy Conversion Device Ocean Power Technologies (TRL 7 8 System) - Reedsport PB150...

384

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

385

E-Print Network 3.0 - alfven waves Sample Search Results  

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

J. Fisch... ; accepted 12 December 2001 Alfven wave propagation in slightly nonuniform cold plasmas is studied by means... of quasistatic plasma density perturbations. The...

386

E-Print Network 3.0 - alfven wave doe Sample Search Results  

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

J. Fisch... ; accepted 12 December 2001 Alfven wave propagation in slightly nonuniform cold plasmas is studied by means... of quasistatic plasma density perturbations. The...

387

E-Print Network 3.0 - alfven wave avalanches Sample Search Results  

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

J. Fisch... ; accepted 12 December 2001 Alfven wave propagation in slightly nonuniform cold plasmas is studied by means... of quasistatic plasma density perturbations. The...

388

Navy Catching Waves in Hawaii | Department of Energy  

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

Navy Catching Waves in Hawaii Navy Catching Waves in Hawaii Navy Catching Waves in Hawaii June 2, 2010 - 11:56am Addthis This experimental power-generating buoy installed off the coast of Oahu can produce enough energy to power 25 homes under optimal conditions. | Photo courtesy of Ocean Power Technologies, Inc. This experimental power-generating buoy installed off the coast of Oahu can produce enough energy to power 25 homes under optimal conditions. | Photo courtesy of Ocean Power Technologies, Inc. To a casual observer, the buoy off the shore of Marine Corps Base Hawaii (MCBH) might look like nothing more than a bright yellow spot in a blue ocean. But this isn't an ordinary buoy - it's a small electrical generator, creating renewable electricity as it bobs up and down on the waves. It's also a test project by the U.S. Navy to see whether a wider

389

Wave and Hydrokinetics Interest Group 1st Meeting of 2009/2010 Year  

E-Print Network (OSTI)

reserved. The State of Wave Energy · Installed Offshore Wave Capacity (as of 6/30/09) - five years . · Economic Status: The first U.S. commercial wave plant project in Reedsport, OR, was made.S. wave power plant license issued by FERC for the 1-MW Makah Bay, WA project was surrendered by Finavera

390

Shock-activated electrochemical power supplies  

DOE Patents (OSTI)

A shock-activated electrochemical power supply is provided which is initiated extremely rapidly and which has a long shelf life. Electrochemical power supplies of this invention are initiated much faster than conventional thermal batteries. Power supplies of this invention comprise an inactive electrolyte and means for generating a high-pressure shock wave such that the shock wave is propagated through the electrolyte rendering the electrolyte electrochemically active. 2 figs.

Benedick, W.B.; Graham, R.A.; Morosin, B.

1987-04-20T23:59:59.000Z

391

Counting energy packets in the electromagnetic wave  

E-Print Network (OSTI)

We discuss the concept of energy packets in respect to the energy transported by electromagnetic waves and we demonstrate that this physical quantity can be used in physical problems involving relativistic effects. This refined concept provides results compatible to those obtained by simpler definition of energy density when relativistic effects apply to the free electromagnetic waves. We found this concept further compatible to quantum theory perceptions and we show how it could be used to conciliate between different physical approaches including the classical electromagnetic wave theory, the special relativity and the quantum theories.

Stefan Popescu; Bernhard Rothenstein

2007-05-18T23:59:59.000Z

392

Energy Storage & Power Electronics 2008 Peer Review - Power Electronics  

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

& Power Electronics 2008 Peer Review - Power & Power Electronics 2008 Peer Review - Power Electronics (PE) Systems Presentations Energy Storage & Power Electronics 2008 Peer Review - Power Electronics (PE) Systems Presentations The 2008 Peer Review Meeting for the DOE Energy Storage and Power Electronics Program (ESPE) was held in Washington DC on Sept. 29-30, 2008. Current and completed program projects were presented and reviewed by a group of industry professionals. The 2008 agenda was composed of 28 projects that covered a broad range of new and ongoing, state-of-the-art, energy storage and power electronics technologies, including updates on the collaborations among DOE/ESPE, CEC in California, and NYSERDA in New York. Power Electronics (PE) Systems presentations are available below. ESPE 2008 Peer Review - High Power Density Silicon Carbide Power Electronic

393

Density scaling and anisotropy in supersonic MHD turbulence  

E-Print Network (OSTI)

We study the statistics of density for supersonic turbulence in a medium with magnetic pressure larger than the gaseous pressure. This study is motivated by molecular cloud research. Our simulations exhibit clumpy density structures, which contrast increases with the Mach number. At 10 Machs densities of some clumps are three orders of magnitude higher than the mean density. These clumps give rise to flat and approximately isotropic density spectrum corresponding to the random distribution of clumps in space. We claim that the clumps originate from our random, isotropic turbulence driving. When the contribution from those clumps is suppressed by studying logarithm of density, the density statistics exhibit scale-dependent anisotropy consistent with the models where density structures arise from shearing by Alfv\\'en waves. It is noteworthy that originally such models were advocated for the case of low-Mach, nearly incompressible turbulence.

A. Beresnyak; A. Lazarian; J. Cho

2005-02-25T23:59:59.000Z

394

Density measurements Viscosity measurements  

E-Print Network (OSTI)

Density measurements Viscosity measurements Temperature measurements Pressure measurements Flow rate measurements Velocity measurements Sensors How to measure fluid flow properties ? Am´elie Danlos Ravelet Experimental methods for fluid flows: an introduction #12;Density measurements Viscosity

Ravelet, Florent

395

Orbital Waves in the A Phase of Superfluid He3  

Science Journals Connector (OSTI)

Orbital waves in the A phase of superfluid He3 are shown to be essentially diffusive. The weak-coupling expression for the "angular superfluid density" tensor C? is obtained.

R. Combescot

1975-12-15T23:59:59.000Z

396

Quantification of the influence of directional sea state parameters over the performances of wave energy converters   

E-Print Network (OSTI)

Accurate predictions of the annual energy yield from wave energy converters are essential to the development of the wave industry. The current method based on power matrices uses only a small part of the data available ...

Pascal, Remy Claude Rene

2012-11-29T23:59:59.000Z

397

E-Print Network 3.0 - atp-induced calcium waves Sample Search...  

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

waves Search Powered by Explorit Topic List Advanced Search Sample search results for: atp-induced calcium waves Page: << < 1 2 3 4 5 > >> 1 Characterization of Calcium-Mediated...

398

Assessment of Projected Life-Cycle Costs for Wave, Tidal, Ocean...  

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

Assessment of Projected Life-Cycle Costs for Wave, Tidal, Ocean Current, and In-Stream Hydrokinetic Power Assessment of Projected Life-Cycle Costs for Wave, Tidal, Ocean Current,...

399

Excitation of electrostatic ion-cyclotron waves by an ion beam in a two-ion component plasma  

SciTech Connect

An ion beam propagating through a magnetized plasma cylinder containing electrons, light positive potassium ions (K{sup +}), and heavy positive cesium ions (Cs{sup +}) drives electrostatic ion cyclotron (EIC) waves to instability via Cerenkov interaction. Two EIC wave modes are present, the K{sup +} and Cs{sup +} modes. The unstable wave frequencies and the growth rate of both the light positive ion and heavy positive ion modes increase with an increase in their relative ion concentrations. The growth rate of both the unstable modes (K{sup +} and Cs{sup +}) scales one-third power of the beam density. The real part of the frequency of both the unstable modes (K{sup +} and Cs{sup +}) increases with the beam energy and scales as almost one-half power of the beam energy. Numerical calculations of the growth rate and mode frequencies have been carried out for the parameters of the experiment of Suszcynsky et al. [J. Geophys. Res. 94, 8966 (1989)]. It is found that the unstable wave frequencies of both the light positive ion and heavy positive ion modes increase with the magnetic fields in accordance with the experimental observations.

Sharma, Jyotsna [Department of Physics, KIIT College of Engineering, Bhondsi Gurgaon 122102 (India); Sharma, Suresh C. [Department of Physics, Maharaja Agrasen Institute of Technology, PSP Area Plot No.-1, Sector-22, Rohini, Delhi 110086 (India)

2010-12-15T23:59:59.000Z

400

PowerPoint Presentation  

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

Arkansas Power Electronics International, Inc. Arkansas Power Electronics International, Inc. DOE Peer Review November 2-3, 2006 Marcelo Schupbach, Ph.D. Senior Engineer APEI, Inc. 535 Research Center Blvd. Fayetteville, AR 72701 Phone: (479)-443-5759 Email: marcelo@apei.net Website: www.apei.net High Temperature and High Power Density SiC Power Electronic Converters Energy Storage Systems Program 2 Overview * APEI, Inc. Corporate Status * Broader Impact of SiC-based Power Converter * DOE Energy Storage System Program Phase I SBIR - SBIR Topic: Wide Band Gap Power Converter Application - APEI's Goals - Phase I Accomplishments * DOE Energy Storage System Program Phase II SBIR - APEI's Goals - Research Team and Partners - Project Status Energy Storage Systems Program 3 APEI, Inc. Mission Statement We are a small business dedicated to

Note: This page contains sample records for the topic "wave power density" 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

Sandia National Laboratories: Sandia Funded to Model Power Pods...  

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

Collaboration for Sandia, UNM Sandia Funded to Model Power Pods for Utility-Scale Wave-Energy Converter On September 16, 2014, in Computational Modeling & Simulation, Energy,...

402

Measuring the Impact of Tidal Power Installations on Endangered...  

Office of Environmental Management (EM)

innovative technologies for clean, domestic power generation from resources such as hydropower, waves, and tides. Addthis Related Articles Portland Company to Receive 1.3 Million...

403

Relic gravitational waves and the generalized second law  

E-Print Network (OSTI)

The generalized second law of gravitational thermodynamics is applied to the present era of accelerated expansion of the Universe. In spite of the fact that the entropy of matter and relic gravitational waves inside the event horizon diminish, the mentioned law is fulfilled provided that the expression for the entropy density of the gravitational waves satisfies a certain condition.

German Izquierdo; Diego Pavon

2005-01-12T23:59:59.000Z

404

Relic gravitational waves and the generalized second law  

SciTech Connect

The generalized second law of gravitational thermodynamics is applied to the present era of accelerated expansion of the Universe. In spite of the fact that the entropy of matter and relic gravitational waves inside the event horizon diminish, the mentioned law is fulfilled provided that the expression for the entropy density of the gravitational waves satisfies a certain condition.

Izquierdo, German; Pavon, Diego [Departamento de Fisica, Universidad Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)

2004-12-15T23:59:59.000Z

405

ccsd00001995, Plasma Production by Helicon Waves with Single  

E-Print Network (OSTI)

ccsd­00001995, version 1 ­ 20 Oct 2004 Plasma Production by Helicon Waves with Single Mode Number density (10 12 10 13 cm 3 ) is obtained with comparatively ease under a low gas pressure of a few hundreds commercially a disadvantage for operating helicon-wave plasma sources with the lower running cost

406

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

407

Neutral depletion and the helicon density limit  

SciTech Connect

It is straightforward to create fully ionized plasmas with modest rf power in a helicon. It is difficult, however, to create plasmas with density >10{sup 20} m{sup ?3}, because neutral depletion leads to a lack of fuel. In order to address this density limit, we present fast (1 MHz), time-resolved measurements of the neutral density at and downstream from the rf antenna in krypton helicon plasmas. At the start of the discharge, the neutral density underneath the antenna is reduced to 1% of its initial value in 15 ?s. The ionization rate inferred from these data implies that the electron temperature near the antenna is much higher than the electron temperature measured downstream. Neutral density measurements made downstream from the antenna show much slower depletion, requiring 14 ms to decrease by a factor of 1/e. Furthermore, the downstream depletion appears to be due to neutral pumping rather than ionization.

Magee, R. M.; Galante, M. E.; Carr, J. Jr.; Lusk, G.; McCarren, D. W.; Scime, E. E. [West Virginia University, Morgantown, West Virginia 26506 (United States)] [West Virginia University, Morgantown, West Virginia 26506 (United States)

2013-12-15T23:59:59.000Z

408

Gravity-related wave function collapse: mass density resolution  

E-Print Network (OSTI)

Selected issues of the concept of spontaneous collapse are discussed, with the emphasis on the gravity-related model. We point out that without spontaneous collapses the Schr\\"odinger cat states would macroscopically violate the standard conservation laws even in the presence of environmental noise. We prove that the collapse time of condensed matter c.o.m. superpositions is not sensitive to the natural uncertainty of the nuclear locations whereas we formulate the conjecture that superfluid He may show an anomalous low rate of spontaneous collapse compared to common condensed matter.

Lajos Diósi

2013-02-21T23:59:59.000Z

409

Using Radio Waves to Control Fusion Plasma Density  

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

heat goes to electrons instead of plasma ions, as would happen in the center of a self-sustaining fusion reaction. Supercomputer simulations run at the Department of Energy's...

410

MHK Technologies/PowerBuoy | Open Energy Information  

Open Energy Info (EERE)

PowerBuoy PowerBuoy < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage PowerBuoy.jpg Technology Profile Primary Organization Oregon Wave Energy Partners LLC Project(s) where this technology is utilized *MHK Projects/Coos Bay OPT Wave Park *MHK Projects/Cornwall Wave Hub *MHK Projects/Griffin Project *MHK Projects/NJBPU 1 5 MW Demonstration Program *MHK Projects/Orkney *MHK Projects/Reedsport OPT Wave Park *MHK Projects/Reedsport OPT Wave Park Expanded Project *MHK Projects/Santona Wave Energy Park *MHK Projects/US Navy Wave Energy Technology WET Program at Marine Corps Base Hawaii MCBH Technology Resource Click here Wave Technology Type Click here Point Absorber Technology Readiness Level Click here TRL 9: Commercial-Scale Production / Application

411

Generation of uniform large-area very high frequency plasmas by launching two specific standing waves simultaneously  

SciTech Connect

With the characteristics of higher electron density and lower ion bombardment energy, large-area VHF (very high frequency) plasma enhanced chemical vapor deposition has become an essential manufacturing equipment to improve the production throughput and efficiency of thin film silicon solar cell. However, the combination of high frequency and large electrodes leads to the so-called standing wave effect causing a serious problem for the deposition uniformity of silicon thin film. In order to address this issue, a technique based on the idea of simultaneously launching two standing waves that possess similar amplitudes and are out of phase by 90° in time and space is proposed in this study. A linear plasma reactor with discharge length of 54?cm is tested with two different frequencies including 60 and 80 MHz. The experimental results show that the proposed technique could effectively improve the non-uniformity of VHF plasmas from >±60% when only one standing wave is applied to <±10% once two specific standing waves are launched at the same time. Moreover, in terms of the reactor configuration adopted in this study, in which the standing wave effect along the much shorter dimension can be ignored, the proposed technique is applicable to different frequencies without the need to alter the number and arrangement of power feeding points.

Chen, Hsin-Liang, E-mail: hlchen@iner.gov.tw; Tu, Yen-Cheng; Hsieh, Cheng-Chang; Lin, Deng-Lain [Physics Division, Institute of Nuclear Energy Research (INER), Longtan, Taoyuan County 32546, Taiwan (China); Leou, Keh-Chyang [Department of Engineering and System Science, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China)

2014-09-14T23:59:59.000Z

412

Nonlinear Mixing of Electromagnetic Waves in Plasmas  

Science Journals Connector (OSTI)

...nc, where ne is the plasma density and n, is...regions X(3) ofa plasma can be orders of magnitude larger than those for other...Conclusions The beat-wave plasma interaction is an important...rapidly growing research area in plasma physics and...

V. STEFAN; B. I. COHEN; C. JOSHI

1989-01-27T23:59:59.000Z

413

Voyager 2 Plasma Wave Observations at Saturn  

Science Journals Connector (OSTI)

...on the basis of plasma probe data) and infer...the weak 3.25-kHz waves represent electro-magnetic...pitch-angle dif-fusion and atmospheric precipitation, but for this low plasma density and high magnetic...f = 0.8 to 1.3 kHz) and a structured...

F. L. SCARF; D. A. GURNETT; W. S. KURTH; R. L. POYNTER

1982-01-29T23:59:59.000Z

414

Generalized F-statistic: Multiple detectors and multiple gravitational wave pulsars  

Science Journals Connector (OSTI)

The F-statistic, derived by Jaranowski, Krolak and Schutz (1998), is the optimal (frequentist) statistic for the detection of nearly periodic gravitational waves from known neutron stars, in the presence of stationary, Gaussian detector noise. The F-statistic was originally derived for the case of a single detector, whose noise spectral density was assumed constant in time, and for a single known neutron star. Here we show how the F-statistic can be straightforwardly generalized to the cases of (1) a network of detectors with time-varying noise curves, and (2) a collection of known sources (e.g., all known millisecond pulsars within some fixed distance). Fortunately, all the important ingredients that go into our generalized F-statistics are already calculated in the single-source/single-detector searches that are currently implemented, e.g., in the Laser Interferometer Gravitational-Wave Observatory software library, so implementation of optimal multidetector, multisource searches should require negligible additional cost in computational power or software development. This paper also includes an analysis of the likely efficacy of a collection-type search, and derives criteria for deciding which candidate sources should be included in a collection, if one is trying to maximize the detectability of the whole. In particular we show that for sources distributed uniformly in a thin disk, the strongest source in the collection should have signal-to-noise-squared ?5 times larger than weakest source, for an optimized collection. We show that gravitational waves from collection of the few brightest (in gravitational waves) neutron stars could perhaps be detected before the single brightest source, but that this is far from guaranteed. Once gravitational waves from the few brightest neutron stars have been discovered, grouping more distant (individually undetectable) pulsars into collections, and then searching for those collections, should be an effective way of measuring the average gravitational-wave strengths of those more distant pulsars.

Curt Cutler and Bernard F. Schutz

2005-09-30T23:59:59.000Z

415

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,

416

Effects of a random spatial variation of the plasma density on the mode conversion in cold, unmagnetized, and stratified plasmas  

SciTech Connect

We study the effects of a random spatial variation of the plasma density on the mode conversion of electromagnetic waves into electrostatic oscillations in cold, unmagnetized, and stratified plasmas. Using the invariant imbedding method, we calculate precisely the electromagnetic field distribution and the mode conversion coefficient, which is defined to be the fraction of the incident wave power converted into electrostatic oscillations, for the configuration where a numerically generated random density variation is added to the background linear density profile. We repeat similar calculations for a large number of random configurations and take an average of the results. We obtain a peculiar nonmonotonic dependence of the mode conversion coefficient on the strength of randomness. As the disorder increases from zero, the maximum value of the mode conversion coefficient decreases initially, then increases to a maximum, and finally decreases towards zero. The range of the incident angle in which mode conversion occurs increases monotonically as the disorder increases. We present numerical results suggesting that the decrease of mode conversion mainly results from the increased reflection due to the Anderson localization effect originating from disorder, whereas the increase of mode conversion of the intermediate disorder regime comes from the appearance of many resonance points and the enhanced tunneling between the resonance points and the cutoff point. We also find a very large local enhancement of the magnetic field intensity for particular random configurations. In order to obtain high mode conversion efficiency, it is desirable to restrict the randomness close to the resonance region.

Jung Yu, Dae [School of Space Research, Kyung Hee University, Yongin 446-701 (Korea, Republic of)] [School of Space Research, Kyung Hee University, Yongin 446-701 (Korea, Republic of); Kim, Kihong [Department of Energy Systems Research, Ajou University, Suwon 443-749 (Korea, Republic of)] [Department of Energy Systems Research, Ajou University, Suwon 443-749 (Korea, Republic of)

2013-12-15T23:59:59.000Z

417

Multiscale modeling of oscillations and spiral waves in Dictyostelium populations  

E-Print Network (OSTI)

Unicellular organisms exhibit elaborate collective behaviors in response to environmental cues. These behaviors are controlled by complex biochemical networks within individual cells and coordinated through cell-to-cell communication. Describing these behaviors requires new mathematical models that can bridge scales -- from biochemical networks within individual cells to spatially structured cellular populations. Here, we present a family of multiscale models for the emergence of spiral waves in the social amoeba Dictyostelium discoideum. Our models exploit new experimental advances that allow for the direct measurement and manipulation of the small signaling molecule cAMP used by Dictyostelium cells to coordinate behavior in cellular populations. Inspired by recent experiments, we model the Dictyostelium signaling network as an excitable system coupled to various pre-processing modules. We use this family of models to study spatially unstructured populations by constructing phase diagrams that relate the properties of population-level oscillations to parameters in the underlying biochemical network. We then extend our models to include spatial structure and show how they naturally give rise to spiral waves. Our models exhibit a wide range of novel phenomena including a density dependent frequency change, bistability, and dynamic death due to slow cAMP dynamics. Our modeling approach provides a powerful tool for bridging scales in modeling of Dictyostelium populations.

Javad Noorbakhsh; David Schwab; Allyson Sgro; Thomas Gregor; Pankaj Mehta

2014-09-12T23:59:59.000Z

418

Electron scattering and nonlinear trapping by oblique whistler waves: The critical wave intensity for nonlinear effects  

SciTech Connect

In this paper, we consider high-energy electron scattering and nonlinear trapping by oblique whistler waves via the Landau resonance. We use recent spacecraft observations in the radiation belts to construct the whistler wave model. The main purpose of the paper is to provide an estimate of the critical wave amplitude for which the nonlinear wave-particle resonant interaction becomes more important than particle scattering. To this aim, we derive an analytical expression describing the particle scattering by large amplitude whistler waves and compare the corresponding effect with the nonlinear particle acceleration due to trapping. The latter is much more rare but the corresponding change of energy is substantially larger than energy jumps due to scattering. We show that for reasonable wave amplitudes ?10–100?mV/m of strong whistlers, the nonlinear effects are more important than the linear and nonlinear scattering for electrons with energies ?10–50?keV. We test the dependencies of the critical wave amplitude on system parameters (background plasma density, wave frequency, etc.). We discuss the role of obtained results for the theoretical description of the nonlinear wave amplification in radiation belts.

Artemyev, A. V., E-mail: ante0226@gmail.com; Vasiliev, A. A. [Space Research Institute, RAS, Moscow (Russian Federation); Mourenas, D.; Krasnoselskikh, V. V. [LPC2E/CNRS—University of Orleans, Orleans (France); Agapitov, O. V. [Space Sciences Laboratory, University of California, Berkeley, California 94720 (United States)

2014-10-15T23:59:59.000Z

419

Field dependence of the vortex structure in d-wave and s-wave superconductors  

Science Journals Connector (OSTI)

We study the vortex structure and its field dependence within the framework of the quasiclassical Eilenberger theory to find the difference between the dx2-y2- and s-wave pairings. We clarify the effect of the dx2-y2-wave nature and the vortex lattice effect on the vortex structure of the pair potential, the internal field and the local density of states. The dx2-y2-wave pairing introduces a fourfold-symmetric structure around each vortex core. With increasing field, their contribution becomes significant to the whole structure of the vortex lattice state, depending on the vortex lattice’s configuration. It is reflected in the form factor of the internal field, which may be detected by small-angle neutron scattering, or the resonance line shape of muon spin resonance and NMR experiments. We also study the induced s- and dxy-wave components around the vortex in dx2-y2-wave superconductors.

Masanori Ichioka; Akiko Hasegawa; Kazushige Machida

1999-04-01T23:59:59.000Z

420

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

Note: This page contains sample records for the topic "wave power density" 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

Evaluation of weld porosity in laser beam seam welds: optimizing continuous wave and square wave modulated processes.  

SciTech Connect

Nd:YAG laser joining is a high energy density (HED) process that can produce high-speed, low-heat input welds with a high depth-to-width aspect ratio. This is optimized by formation of a ''keyhole'' in the weld pool resulting from high vapor pressures associated with laser interaction with the metallic substrate. It is generally accepted that pores form in HED welds due to the instability and frequent collapse of the keyhole. In order to maintain an open keyhole, weld pool forces must be balanced such that vapor pressure and weld pool inertia forces are in equilibrium. Travel speed and laser beam power largely control the way these forces are balanced, as well as welding mode (Continuous Wave or Square Wave) and shielding gas type. A study into the phenomenon of weld pool porosity in 304L stainless steel was conducted to better understand and predict how welding parameters impact the weld pool dynamics that lead to pore formation. This work is intended to aid in development and verification of a finite element computer model of weld pool fluid flow dynamics being developed in parallel efforts and assist in weld development activities for the W76 and future RRW programs.

Ellison, Chad M. (Honeywell FM& T, Kansas City, MO); Perricone, Matthew; Faraone, Kevin M. (Honeywell FM& T, Kansas City, MO); Roach, Robert Allen; Norris, Jerome T.

2007-02-01T23:59:59.000Z

422

Density dependence of reactor performance with thermal confinement scalings  

SciTech Connect

Energy confinement scalings for the thermal component of the plasma published thus far have a different dependence on plasma density and input power than do scalings for the total plasma energy. With such thermal scalings, reactor performance (measured by Q, the ratio of the fusion power to the sum of the ohmic and auxiliary input powers) worsens with increasing density. This dependence is the opposite of that found using scalings based on the total plasma energy, indicating that reactor operation concepts may need to be altered if this density dependence is confirmed in future research.

Stotler, D.P.

1992-03-01T23:59:59.000Z

423

Power Spectra in V-band and Halpha of Nine Irregular Galaxies  

E-Print Network (OSTI)

Fourier transform power spectra of major axis cuts in V and Halpha images were made for a sample of 9 irregular galaxies. These power spectra reveal structure over a wide range of scales. For 6 of the galaxies the power spectrum slopes at intermediate scales (1-400 pc) in the V-band images range from -1.3 to -1.5. The similarity of slopes suggests that the same processes are structuring these systems. These slopes are slightly shallower than what is observed in other galaxies in HI, molecular emission, dust extinction, and optical light. Three of the galaxies have flat power spectra like noise from the sky; these three galaxies are relatively indistinct in the direct images. The power spectrum slope for Halpha steepens with increasing star formation rate, ranging from a shallow value comparable to the noise at low rates to a steep value with a slope of -1.5 at high rates. This change reflects the increasing areal filling factor of Halpha emission with increasing star formation rate, and an apparently universal slope inside the Halpha regions that is comparable to that for Kolmogorov turbulence. The power spectrum of HI in one galaxy has a steeper power law, with a slope of -2.9. The fact that the power laws of star formation are about the same for dwarf galaxies and giant spiral galaxies suggests the microscopic processes are the same, independent of spiral density waves and galaxy size.

Kyle W. Willett; Bruce G. Elmegreen; Deidre A. Hunter

2005-03-14T23:59:59.000Z

424

Can New Nuclear Power Plants be Project Financed?  

E-Print Network (OSTI)

This paper considers the prospects for financing a wave of new nuclear power plants (NPP) using project financing, which is used widely in large capital intensive infrastructure investments, including the power and gas sectors, but has...

Taylor, Simon

425

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

426

Ion temperature in plasmas with intrinsic Alfven waves  

SciTech Connect

This Brief Communication clarifies the physics of non-resonant heating of protons by low-frequency Alfvenic turbulence. On the basis of general definition for wave energy density in plasmas, it is shown that the wave magnetic field energy is equivalent to the kinetic energy density of the ions, whose motion is induced by the wave magnetic field, thus providing a self-consistent description of the non-resonant heating by Alfvenic turbulence. Although the study is motivated by the research on the solar corona, the present discussion is only concerned with the plasma physics of the heating process.

Wu, C. S. [CAS Key Laboratory of Geospace Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei (China); Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742 (United States); Yoon, P. H. [Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742 (United States); School of Space Research, Kyung Hee University, Yongin, Gyeonggi 446-701 (Korea, Republic of); Wang, C. B. [CAS Key Laboratory of Geospace Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei (China)

2014-10-15T23:59:59.000Z

427

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

428

MHK Technologies/Magnetohydrodynamic MHD Wave Energy Converter MWEC | Open  

Open Energy Info (EERE)

Magnetohydrodynamic MHD Wave Energy Converter MWEC Magnetohydrodynamic MHD Wave Energy Converter MWEC < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Magnetohydrodynamic MHD Wave Energy Converter MWEC.jpg Technology Profile Primary Organization Scientific Applications Research Associates Inc SARA Technology Resource Click here Wave Technology Type Click here Point Absorber - Submerged Technology Readiness Level Click here TRL 5 6 System Integration and Technology Laboratory Demonstration Technology Description The Magnetohydrodynamic MHD Wave Energy Converter couples the up down motion of heave based systems A shaft transfers wave motion to the MHD generator which is deep underwater The shaft forces the conducting fluid through a set of powerful permanent magnets creating a low voltage high current electrical energy An electrical inverter converts the electrical energy to commercial quality 60 Hz AC power

429

Title of Document: LONGITUDINAL SPACE-CHARGE WAVES INDUCED BY ENERGY MODULATIONS  

E-Print Network (OSTI)

ABSTRACT Title of Document: LONGITUDINAL SPACE-CHARGE WAVES INDUCED BY ENERGY MODULATIONS Brian L. Modulations in energy or density can induce space-charge waves at low energies which could be problematic at higher energies. This thesis is a study of longitudinal space-charge waves induced by energy modulations

Anlage, Steven

430

Dual use power supply development  

Science Journals Connector (OSTI)

Size weight efficiency and reliability define space power systems. Then years ago NASA re?emphasized that missions such as Space Station needed cost effective critical technologies one being power conversion. Thus NASA began to emphasize ‘‘dual?use’’ technology through its center for Commercial Development of Space (mid 1980s). This CCDS program funded research and development efforts needed for future space missions as well as terrestrial applications for commercial markets. Maxwell and Auburn University (Space Power Institute) jointly developed reliable power systems for manned space projects as well as commercial applications of high power high voltage switchmode power supplies. These serve the medical scientific and industrial markets (lasers accelerators and intense light sources). These applications required improvements in power density efficiency regulation reliability and cost effectiveness to be successful. One of NASA’s first programs at Auburn and Maxwell was a high frequency series resonant power converter optimized for commercial applications. It also meets the needs of space missions (additional space flight qualification is needed). This power converter topology demonstrates dual?use technology for power density power?to?weight regulation reliability and cost effectiveness. All goals were exceeded for both space and terrestrial applications. This was the first product of NASA’s CCDS program producing a family of high voltage capacitor charging power supplies. Maxwell’s CCDS capacitor power supplies are achieving greater acceptance demonstrating the value of the CCDS program.

Alan C. Kolb; Bryan E. Strickland

1995-01-01T23:59:59.000Z

431

Cyclotron waves in a non-neutral plasma column  

SciTech Connect

A kinetic theory of linear electrostatic plasma waves with frequencies near the cyclotron frequency {Omega}{sub c{sub s}} of a given plasma species s is developed for a multispecies non-neutral plasma column with general radial density and electric field profiles. Terms in the perturbed distribution function up to O(1/{Omega}{sub c{sub s}{sup 2}}) are kept, as are the effects of finite cyclotron radius r{sub c} up to O(r{sub c}{sup 2}). At this order, the equilibrium distribution is not Maxwellian if the plasma temperature or rotation frequency is not uniform. For r{sub c}{yields}0, the theory reproduces cold-fluid theory and predicts surface cyclotron waves propagating azimuthally. For finite r{sub c}, the wave equation predicts that the surface wave couples to radially and azimuthally propagating Bernstein waves, at locations where the wave frequency equals the local upper hybrid frequency. The equation also predicts a second set of Bernstein waves that do not couple to the surface wave, and therefore have no effect on the external potential. The wave equation is solved both numerically and analytically in the WKB approximation, and analytic dispersion relations for the waves are obtained. The theory predicts that both types of Bernstein wave are damped at resonances, which are locations where the Doppler-shifted wave frequency matches the local cyclotron frequency as seen in the rotating frame.

Dubin, Daniel H. E. [Department of Physics, University of California at San Diego, La Jolla, California 92093 (United States)

2013-04-15T23:59:59.000Z

432

The Spectrum of High-Frequency Internal Waves in the Atmospheric Waveguide  

Science Journals Connector (OSTI)

The vertical structure and power spectrum of the field of internal waves generated in the atmospheric waveguide by random vertical displacements were considered in this paper.

I. P. Chunchuzov

1996-07-01T23:59:59.000Z

433

Ocean 420 Physical Processes in the Ocean Project 6: Waves  

E-Print Network (OSTI)

that the storm generates 30 min period motion through interactions in the mixed layer. What angle from. The upper layer density is 1028 kg/m3, and the density is 1029 kg/m3 in the lower layer. a) A wind event generates an upwelling internal wave at 30N with a positive deviation in interface height of size 30m. What

Thompson, LuAnne

434

Self-similar solutions for the emergence of energy varying shock waves from plane-parallel atmospheres  

E-Print Network (OSTI)

We present a self-similar solution to describe the propagation of a shock wave whose energy is deposited or lost at the front. Both of the propagation of the shock wave in a medium having a power-law density profile and the expansion of the medium to a vacuum after the shock breakout are described with a Lagrangian coordinate. The Chapman-Jouguet detonation is found to accelerate the medium most effectively. The results are compared with some numerical simulations in the literature. We derive the fractions of the deposited/lost energy at the shock front in some specific cases, which will be useful when applying this solution to actual phenomena.

Akihiro Suzuki; Toshikazu Shigeyama

2007-02-09T23:59:59.000Z

435

Manta Wings: Wave Energy Testing Floats to Puget Sound | Department of  

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

Manta Wings: Wave Energy Testing Floats to Puget Sound Manta Wings: Wave Energy Testing Floats to Puget Sound Manta Wings: Wave Energy Testing Floats to Puget Sound August 6, 2010 - 11:27am Addthis The 1:15 scale prototype being lowered into the wave flume at Oregon State University's O.H. Hinsdale Wave Research Laboratory | Photo courtesy of Columbia Power The 1:15 scale prototype being lowered into the wave flume at Oregon State University's O.H. Hinsdale Wave Research Laboratory | Photo courtesy of Columbia Power Lindsay Gsell Columbia Power Technologies plans to test an intermediate-scale version of its wave energy converter device in Puget Sound later this year. After the successful control tests, the company will move testing to open water in Puget Sound this fall. Columbia will test the intermediate 1:7

436

WEC up! Energy Department Announces Wave Energy Conversion Prize Administrator  

Office of Energy Efficiency and Renewable Energy (EERE)

The Water Power Program today awarded $6.5 million to a Prize Administration Team for the development and execution of the Energy Department’s Wave Energy Conversion (WEC) Prize Competition. The WEC Prize will continue to advance marine and hydrokinetic (MHK) technology as a viable source for America’s clean energy future, in part by providing an opportunity for developers to test their innovative wave energy conversion (WEC) devices in a wave generating basin.

437

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

438

Karhunen–Loeve representation of stochastic ocean waves  

Science Journals Connector (OSTI)

...stochastic ocean wave elevations and wind speed profiles is finally addressed...and design of fixed and floating offshore wind turbines and for the forecasting...wind speeds and power output of wind farms. 2. Spectral decomposition of...

2012-01-01T23:59:59.000Z

439

Sandia National Laboratories: Advanced Controls of Wave Energy...  

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

New Facility Tool at SWiFT Makes Rotor Work More Efficient Advanced Controls of Wave Energy Converters May Increase Power Capture Up to 330% On January 21, 2014, in...

440

Oregon Wave Energy Partners LLC | Open Energy Information  

Open Energy Info (EERE)

PowerBuoy This article is a stub. You can help OpenEI by expanding it. Retrieved from "http:en.openei.orgwindex.php?titleOregonWaveEnergyPartnersLLC&oldid76930...

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


441

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

442

Simulation of anisotropic wave propagation in Vertical Seismic Profiles  

E-Print Network (OSTI)

they are powerful tools to simulate seismic wave propagation in three-dimensional anisotropic subsurface models. The code is currently under development using a C++ object oriented programming approach because it provides high flexibility in the design of new...

Durussel, Vincent Bernard

2004-09-30T23:59:59.000Z

443

High power  

Science Journals Connector (OSTI)

... 1970s technomanic projects such as nuclear power stations were still in vogue. Environmentalists argued that solar power seemed a far safer, cheaper and reassuringly low-tech power source. The technomaniacs ... tech power source. The technomaniacs, fearing that they were losingthis argument, sought to hijack solar power themselves. They proposed an enormously expensive and complicated ...

David Jones

1994-03-03T23:59:59.000Z

444

Frequency spectrum analysis of electromagnetic waves radiated by electrical discharges  

Science Journals Connector (OSTI)

In this study, we analyzed the frequency spectrum of the electromagnetic waves radiated by an electric discharge as a basic method for developing an on-line diagnostic technique for power equipment installed inside closed-switchboards. In order to simulate ... Keywords: closed-switchboard, electromagnetic shielding room, electromagnetic wave, frequency spectrum, local discharge, series arc discharge

Hyeon-Kyu Cha; Sun-Jae Kim; Dae-Won Park; Gyung-Suk Kil

2011-03-01T23:59:59.000Z

445

Surface Ion Cyclotron Waves Propagating Across an External Magnetic Field  

SciTech Connect

Properties of ordinary polarized surface ion cyclotron waves (SICW) propagating along boundary of non-uniform plasma at harmonics of ion cyclotron frequency are studied. Analytical expressions for eigen frequency and damping rates determined by collision and collisionless mechanisms are derived. Influence of plasma waveguide system on spatial distribution of the waves' field and power flow is examined both analytically and numerically.

Girka, Volodymyr O.; Girka, Igor O.; Klyzhka, Anton V.; Pavlenko, Ivan V. [Kharkiv 'Karazin' National University, Department of Physics and Technology, Svobody sq., 4, Kharkiv, 61077 (Ukraine)

2009-11-26T23:59:59.000Z

446

On Heating of Cluster Cooling Flows by Sound Waves  

E-Print Network (OSTI)

We investigate heating of the cool core of a galaxy cluster through the dissipation of sound waves excited by the activities of the central active galactic nucleus (AGN). Using a weak shock theory, we show that this heating mechanism alone cannot reproduce observed temperature and density profiles of a cluster, because the dissipation length of the waves is much smaller than the size of the core and thus the wave energy is not distributed to the whole core. However, we find that if it is combined with thermal conduction from the hot outer layer of the cluster, the wave heating can reproduce the observational results.

Yutaka Fujita; Takeru Ken Suzuki

2005-08-10T23:59:59.000Z

447

The Wave Function and Quantum Reality  

SciTech Connect

We investigate the meaning of the wave function by analyzing the mass and charge density distributions of a quantum system. According to protective measurement, a charged quantum system has effective mass and charge density distributing in space, proportional to the square of the absolute value of its wave function. In a realistic interpretation, the wave function of a quantum system can be taken as a description of either a physical field or the ergodic motion of a particle. The essential difference between a field and the ergodic motion of a particle lies in the property of simultaneity; a field exists throughout space simultaneously, whereas the ergodic motion of a particle exists throughout space in a time-divided way. If the wave function is a physical field, then the mass and charge density will be distributed in space simultaneously for a charged quantum system, and thus there will exist gravitational and electrostatic self-interactions of its wave function. This not only violates the superposition principle of quantum mechanics but also contradicts experimental observations. Thus the wave function cannot be a description of a physical field but be a description of the ergodic motion of a particle. For the later there is only a localized particle with mass and charge at every instant, and thus there will not exist any self-interaction for the wave function. It is further argued that the classical ergodic models, which assume continuous motion of particles, cannot be consistent with quantum mechanics. Based on the negative result, we suggest that the wave function is a description of the quantum motion of particles, which is random and discontinuous in nature. On this interpretation, the square of the absolute value of the wave function not only gives the probability of the particle being found in certain locations, but also gives the probability of the particle being there. The suggested new interpretation of the wave function provides a natural realistic alternative to the orthodox interpretation, and it also implies that the de Broglie-Bohm theory and many-worlds interpretation are wrong and the dynamical collapse theories are in the right direction by admitting wavefunction collapse.

Gao Shan [Unit for History and Philosophy of Science and Centre for Time, SOPHI, University of Sydney, Sydney, NSW 2006 (Australia)

2011-03-28T23:59:59.000Z

448

Density Functional Theory with Dissipation: Transport through Single Molecules  

SciTech Connect

A huge amount of fundamental research was performed on this grant. Most of it focussed on fundamental issues of electronic structure calculations of transport through single molecules, using density functional theory. Achievements were: (1) First density functional theory with dissipation; (2) Pseudopotential plane wave calculations with master equation; (3) Weak bias limit; (4) Long-chain conductance; and (5) Self-interaction effects in tunneling.

Kieron Burke

2012-04-30T23:59:59.000Z

449

MHK Technologies/Wave Water Pump WWP | Open Energy Information  

Open Energy Info (EERE)

Pump WWP Pump WWP < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Wave Water Pump WWP.gif Technology Profile Primary Organization Renewable Energy Wave Pumps Technology Resource Click here Wave Technology Description The Water Wave Pump WWP is a point absorber that uses a submerged water pump to lift a small quantity of water to a higher head collect it in a piping network and feed it to a hydro turbine to produce power Mooring Configuration Gravity base installed at the sea bed Optimum Marine/Riverline Conditions The REWP can pump water to a hgih head fro waves ranging between 1 2 meters to waves in excess of 4 meters high It self adjusts to varyilng sea levels and wave hights It resists storms safe to navigation as red floats are clearly seen during the day and red flashing lights during the night It does not disturb marine life or shore line scenic view

450

Non-linear wave equations Hans Ringstrom  

E-Print Network (OSTI)

105 3. Power type non-linearities 108 4. Global existence for small data 109 5. Observations the Maxwell vacuum equations for an electric and magnetic potential also yields wave equations. In order differential equations (PDE:s) is quite big. The linear theory is based on the fact that by adding two

Ringström, Hans

451

Optical rogue waves D. R. Solli1  

E-Print Network (OSTI)

observations show that the probability of encountering an extremely large rogue wave in the open ocean is much that they arise infrequently from initially smoothpulses owing to power transfer seeded by a small noise for the first time by scientific measurements during an encounter at the Draupner oil platform in the North Sea3

Jalali. Bahram

452

Power Marketing  

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

UGPS' Marketing Service Area Power Marketing As a marketer of Federal power in the Upper Great Plains Region, the Power Marketing staff provides a variety of services for customers...

453

Inner magnetosphere plasma densities  

E-Print Network (OSTI)

The radio plasma imager (RPI) on the IMAGE satellite performs radio sounding in the magnetosphere, transmitting coded signals stepping through the frequency range of interest and receiving the returned echoes. The measurements provide the echo amplitude as a function of frequency and echo delay time on a so-called plasmagram. A newly developed algorithm inverts THE echo traces on a plasmagram to electron density spatial distributions. Based on these observed density distributions, an empirical model is constructed to describe the two-dimensional density distribution in the inner magnetosphere.

Reinisch, B W

2002-01-01T23:59:59.000Z

454

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

455

UTILITY OF EXTRACTING CY PARTICLE ENERGY BY WAVES N.J. FISCH, M.C. HERRMANN  

E-Print Network (OSTI)

UTILITY OF EXTRACTING CY PARTICLE ENERGY BY WAVES N.J. FISCH, M.C. HERRMANN Princeton Plasma. The utility of extracting CY particle power, and then diverting this power to fast fuel ions, is investigated

456

Hydrodynamic Optimisation of point wave-energy converter using laboratory experiments.  

E-Print Network (OSTI)

??Investment in renewable energy technology, such as wave power, is increasingly seen as a beneficial and economically-viable alternative to existing fossil-based power plants. New Zealand… (more)

Kelly, Scott John

2007-01-01T23:59:59.000Z

457

Definition: Wind power | Open Energy Information  

Open Energy Info (EERE)

Wind power Wind power Jump to: navigation, search Dictionary.png Wind power The amount of power available to a wind turbine depends on: air density, wind speed and the swept area of the rotor. While the power is proportional to air density and swept area, it varies with the cube of wind speed, so small changes in wind speed can have a relatively large impact on wind power.[1] View on Wikipedia Wikipedia Definition Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electrical power, windmills for mechanical power, windpumps for water pumping or drainage, or sails to propel ships. Large wind farms consist of hundreds of individual wind turbines which are connected to the electric power transmission network. Offshore wind is steadier and stronger than on land, and offshore farms

458

NREL: Water Power Research Home Page  

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

Aerial photo of ocean waves breaking as they near the shore. Aerial photo of ocean waves breaking as they near the shore. NREL's water power technologies research leverages 35 years of experience developing renewable energy technologies to support the U.S. Department of Energy Water Power Program's efforts to research, test, evaluate, develop and demonstrate deployment of innovative water power technologies. These include marine and hydrokinetic technologies, a suite of renewable technologies that harness the energy from untapped wave, tidal, current and ocean thermal resources, as well as technologies and processes to improve the efficiency, flexibility, and environmental performance of hydropower generation. The vision of the water power team at NREL is to be an essential partner for the technical development and deployment of water power technologies.

459

Magnetic Field Generation by Detonation Waves  

Science Journals Connector (OSTI)

A simple model is given for the spontaneous magnetic field generation by a detonation wave in condensed matter. The field is shown to arise from the noncollinearity of the thermal and electron density gradients near a medium boundary at the detonation shock front. The model allows calculation of approximate values for the field strength at the front and penetration ahead of the detonation wave. For typical explosive media interfaced by air the magnetic field is predicted to lie in the range 0.1 to 15 G.

Michael J. Frankel and Edward T. Toton

1979-12-10T23:59:59.000Z

460

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

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


461

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

462

An Isofactorial Change-of-Scale Model for the Wind Speed Probability Density Function  

Science Journals Connector (OSTI)

The wind speed probability density function (PDF) is used in a variety of applications in meteorology, oceanography, and climatology usually as a dataset comparison tool of a function of a quantity such as momentum flux or wind power density. The ...

Mark L. Morrissey; Angie Albers; J. Scott Greene; Susan Postawko

2010-02-01T23:59:59.000Z

463

Early Type Galaxy Core Phase Densities  

E-Print Network (OSTI)

Early type galaxies, ellipticals and S0's, have two distinct core density profiles, either a power law or nearly flat in projection. The two core types are distributed with substantial overlap in luminosity, radius, mass and velocity dispersion, however, the cores separate into two distinct distributions in their coarse grain phase density, Q_0 = rho/sigma^3,suggesting that dynamical processes played a dominant role in their origin. The transition phase density separating the two elliptical types is approximately 0.003 M_sun pc^-3 km^-3 s^3,. The Q_0*M_c^2 vs M_c diagram shows that globular clusters, nuclear star clusters and power-law cores fall on what is likely a "collisional" sequence of inspiralling globular clusters. on which the relative core mass excess varies as the bulk stellar mass to the -0.34+/-0.08 power, close to predictions, albeit with a correlation coefficient of -0.46. Both power-law and cored galaxies lie on a single sequence of approximately Q_0 ~r_c^-2.2, suggesting that transport proces...

Carlbeg, Raymond

2014-01-01T23:59:59.000Z

464

Study of Density Behavior During LHCD and IBW Heating in the HT-7 Superconducting Tokamak  

Science Journals Connector (OSTI)

A new method using special shape parameters has been introduced to study density behavior with synergy of lower hybrid current drive (LHCD) and ion Bernstein wave (IBW) heating in the HT-7 superconducting tokamak

M. Asif; X. Gao

2004-09-01T23:59:59.000Z

465

Cancellation of four-wave mixing in a single-mode fiber by midway optical phase conjugation  

Science Journals Connector (OSTI)

Cancellation of waves generated by four-wave mixing (FWM) in a single-mode fiber by use of midway optical phase conjugation is proposed and analyzed, and the possible power reduction...

Watanabe, Shigeki

1994-01-01T23:59:59.000Z

466

Observation of ionization fronts in low density foam targets  

SciTech Connect

Ionization fronts have been observed in low density chlorinated foam targets and low density foams confined in gold tubes using time resolved {ital K}-shell absorption spectroscopy. The front was driven by an intense pulse of soft x-rays produced by high power laser irradiation. The density and temperature profiles inferred from the radiographs provided detailed measurement of the conditions. The experimental data were compared to radiation hydrodynamics simulations and reasonable agreement was obtained. {copyright} {ital 1999 American Institute of Physics.}

Hoarty, D. [Imperial College of Science, Technology and Medicine, London (United Kingdom)] [Imperial College of Science, Technology and Medicine, London (United Kingdom); [Radiation Physics Department, AWE Aldermaston, Reading, Berkshire (United Kingdom); Willi, O.; Barringer, L.; Vickers, C. [Imperial College of Science, Technology and Medicine, London (United Kingdom)] [Imperial College of Science, Technology and Medicine, London (United Kingdom); Watt, R. [P24, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [P24, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Nazarov, W. [Chemistry Department, University of Dundee (United Kingdom)] [Chemistry Department, University of Dundee (United Kingdom)

1999-05-01T23:59:59.000Z

467

LOCALIZATION OF DEFECTS IN PIPES USING GUIDED WAVES AND SYNTHETIC APERTURE FOCUSSING TECHNIQUE (SAFT)  

E-Print Network (OSTI)

, 2011, the federal government decided to shut down the nuclear power plants until 2022 and announced problem is solved by the simulation soft- ware Wave3000Plus to determine well-suited wave modes a cylin- drical test structure were performed to verify the simulation results. Varying wave modes provide

Boyer, Edmond

468

Oceanic Internal-Wave Field: Theory of Scale-Invariant Spectra YURI V. LVOV  

E-Print Network (OSTI)

of a nearly universal internal-wave energy spectrum in the ocean, first described by Garrett and Munk (Garrett framework that allows a detailed analysis of power-law spectra of internal waves in the ocean. WeOceanic Internal-Wave Field: Theory of Scale-Invariant Spectra YURI V. LVOV Rensselaer Polytechnic

Tabak, Esteban G.

469

Mechanical Surface Waves Accompany Action Potential Propagation  

E-Print Network (OSTI)

Many studies have shown that a mechanical displacement of the axonal membrane accompanies the electrical pulse defining the Action Potential (AP). Despite a large and diverse body of experimental evidence, there is no theoretical consensus either for the physical basis of this mechanical wave nor its interdependence with the electrical signal. In this manuscript we present a model for these mechanical displacements as arising from the driving of surface wave modes in which potential energy is stored in elastic properties of the neuronal membrane and cytoskeleton while kinetic energy is carried by the axoplasmic fluid. In our model these surface waves are driven by the traveling wave of electrical depolarization that characterizes the AP, altering the compressive electrostatic forces across the membrane as it passes. This driving leads to co-propagating mechanical displacements, which we term Action Waves (AWs). Our model for these AWs allows us to predict, in terms of elastic constants, axon radius and axoplasmic density and viscosity, the shape of the AW that should accompany any traveling wave of voltage, including the AP predicted by the Hodgkin and Huxley (HH) equations. We show that our model makes predictions that are in agreement with results in experimental systems including the garfish olfactory nerve and the squid giant axon. We expect our model to serve as a framework for understanding the physical origins and possible functional roles of these AWs in neurobiology.

Ahmed El Hady; Benjamin B. Machta

2014-07-28T23:59:59.000Z

470

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

471

Improving the assessment of wave energy resources by means of coupled wave-ocean numerical modeling  

Science Journals Connector (OSTI)

Abstract Sea waves energy represents a renewable and sustainable energy resource, that nevertheless needs to be further investigated to make it more cost-effective and economically appealing. A key step in the process of Wave Energy Converters (WEC) deployment is the energy resource assessment at a sea site either measured or obtained through numerical model analysis. In these kind of studies, some approximations are often introduced, especially in the early stages of the process, viz. waves are assumed propagating in deep waters without underneath ocean currents. These aspects are discussed and evaluated in the Adriatic Sea and its northern part (Gulf of Venice) using locally observed and modeled wave data. In particular, to account for a “state of the art” treatment of the Wave–Current Interaction (WCI) we have implemented the Simulating \\{WAves\\} Nearshore (SWAN) model and the Regional Ocean Modeling System (ROMS), fully coupled within the Coupled Ocean Atmosphere Wave Sediment Transport (COAWST) system. COAWST has been applied to a computational grid covering the whole Adriatic Sea and off-line nested to a high-resolution grid in the Gulf of Venice. A 15-year long wave data set collected at the oceanographic tower “Acqua Alta”, located approximately 15 km off the Venice coast, has also been analyzed with the dual purpose of providing a reference to the model estimates and to locally assess the wave energy resource. By using COAWST, we have quantified for the first time to our best knowledge the importance of the WCI effect on wave power estimation. This can vary up to 30% neglecting the current effect. Results also suggest the Gulf of Venice as a suitable testing site for WECs, since it is characterized by periods of calm (optimal for safe installation and maintenance) alternating with severe storms, whose wave energy potentials are comparable to those ordinarily encountered in the energy production sites.

Francesco Barbariol; Alvise Benetazzo; Sandro Carniel; Mauro Sclavo

2013-01-01T23:59:59.000Z

472

Electromagnetic energy storage and power dissipation in nanostructures  

E-Print Network (OSTI)

The processes of storage and dissipation of electromagnetic energy in nanostructures depend on both the material properties and the geometry. In this paper, the distributions of local energy density and power dissipation in nanogratings are investigated using the rigorous coupled-wave analysis. It is demonstrated that the enhancement of absorption is accompanied by the enhancement of energy storage both for material at the resonance of its dielectric function described by the classical Lorentz oscillator and for nanostructures at the resonance induced by its geometric arrangement. The appearance of strong local electric field in nanogratings at the geometry-induced resonance is directly related to the maximum electric energy storage. Analysis of the local energy storage and dissipation can also help gain a better understanding of the global energy storage and dissipation in nanostructures for photovoltaic and heat transfer applications.

Zhao, J M

2014-01-01T23:59:59.000Z

473

Analysis of pulsed high-density HBr and Cl{sub 2} plasmas: Impact of the pulsing parameters on the radical densities  

SciTech Connect

The dynamic of charged particles in pulsed plasma is relatively well known since the 1990s. In contrast, works reporting on the impact of the plasma modulation frequency and duty cycle on the radicals' densities are scarce. In this work, we analyze the impact of these modulation parameters on the radicals' composition in Cl{sub 2} and HBr plasmas. The radicals' densities are measured by broad-band UV and vacuum-ultraviolet (VUV) absorption spectroscopy and modulated-beam mass spectrometry. We show that pulsing the rf power allows controlling the plasma chemistry and gives access to the plasma conditions that cannot be reached in continuous wave plasmas. In particular, we show that above 500 Hz, the pulsing frequency has no influence on the plasma chemistry, whereas in contrast the duty cycle is an excellent knob to control the fragmentation of the parent gas, thus the chemical reactivity of the discharge. At low duty cycle, a reduced gas fragmentation combined with a large ion flux leads to new etching conditions, compared to cw plasmas and the expected consequences on pulsed-etching processes are discussed.

Bodart, P.; Brihoum, M.; Cunge, G.; Joubert, O.; Sadeghi, N. [Laboratoire des Technologies de la Microelectronique, CNRS-LTM, 17 rue des Martyrs, Grenoble 38054 (France)

2011-12-01T23:59:59.000Z

474

MHK Technologies/hyWave | Open Energy Information  

Open Energy Info (EERE)

hyWave hyWave < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage HyWave.png Technology Profile Primary Organization Wavegen subsidiary of Voith Siemens Hydro Power Generation Project(s) where this technology is utilized *MHK Projects/Mutriku *MHK Projects/Wavegen Technology Resource Click here Wave Technology Readiness Level Click here TRL 1-3: Discovery / Concept Definition / Early Stage Development & Design & Engineering Technology Description The hyWave device rests directly on the seabed and is designed to operate in the near-shore environment in a nominal mean water depth of 15m. Optimum performance will be achieved when driven by a long ocean swell. The pneumatic power of the oscillating water column (OWC) is converted to electricity by a Wells generator and specially designed induction generators.

475

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

476

Power Electronics Design of a Solar Powered In-car Wireless Tag for Asset Tracking and Parking Applications  

E-Print Network (OSTI)

Power Electronics Design of a Solar Powered In-car Wireless Tag for Asset Tracking and Parking and testing of a power conditioning circuit for a solar powered in-car wireless tag for asset tracking. A suitable solar cell was chosen for its high power density. Charging circuit, hysteresis control circuit

477

A Universality in PP-Waves  

E-Print Network (OSTI)

We discuss a universality property of any covariant field theory in space-time expanded around pp-wave backgrounds. According to this property the space-time lagrangian density evaluated on a restricted set of field configurations, called universal sector, turns out to be same around all the pp-waves, even off-shell, with same transverse space and same profiles for the background scalars. In this paper we restrict our discussion to tensorial fields only. In the context of bosonic string theory we consider on-shell pp-waves and argue that universality requires the existence of a universal sector of world-sheet operators whose correlation functions are insensitive to the pp-wave nature of the metric and the background gauge flux. Such results can also be reproduced using the world-sheet conformal field theory. We also study such pp-waves in non-polynomial closed string field theory (CSFT). In particular, we argue that for an off-shell pp-wave ansatz with flat transverse space and dilaton independent of transverse coordinates the field redefinition relating the low energy effective field theory and CSFT with all the massive modes integrated out is at most quadratic in fields. Because of this simplification it is expected that the off-shell pp-waves can be identified on the two sides. Furthermore, given the massless pp-wave field configurations, an iterative method for computing the higher massive modes using the CSFT equations of motion has been discussed. All our bosonic string theory analyses can be generalised to the common Neveu-Schwarz sector of superstrings.

Partha Mukhopadhyay

2007-04-09T23:59:59.000Z

478

Density Functional Theory for Superconductors  

E-Print Network (OSTI)

Density Functional Theory for Superconductors LATHIOTAKIS, A. MARQUES, 1,2,3 LU DERS, L. FAST, 2004 words: theory superconductors; density functional theory; critical temperature; exchange matter physics theoretical chemistry is density functional theory (DFT). foundations were established mid

Gross, E.K.U.

479

Relativistic Nuclear Energy Density Functionals  

Science Journals Connector (OSTI)

......research-article Articles Relativistic Nuclear Energy Density Functionals Dario Vretenar...196, 2012 137 Relativistic Nuclear Energy Density Functionals Dario Vretenar...and P. Ring 2. Relativistic nuclear energy density functionals Even though......

Dario Vretenar; Tamara Niksic; Peter Ring

2012-10-01T23:59:59.000Z

480

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