Sample records for tidal wave current

  1. Seasonal patterns of coarse sediment transport on a mixed sand and gravel beach due to vessel wakes, wind waves, and tidal currents

    E-Print Network [OSTI]

    Talke, Stefan

    Seasonal patterns of coarse sediment transport on a mixed sand and gravel beach due to vessel wakes, wind waves, and tidal currents Gregory M. Curtiss a, , Philip D. Osborne b,1 , Alexander R. Horner December 2008 Accepted 29 December 2008 Keywords: mixed sand and gravel beach ferry wake wash beach

  2. 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,...

  3. European Wave and Tidal Energy Conference

    Broader source: Energy.gov [DOE]

    The European Wave and Tidal Energy Conference (EWTEC) series are international, technical and scientific conferences, focussed on ocean renewable energy and widely respected for their commitment to...

  4. Internal wave and boundary current generation by tidal flow over topography Amadeus Dettner, Harry L. Swinney, and M. S. Paoletti

    E-Print Network [OSTI]

    Texas at Austin. University of

    .1063/1.4808163 Negative turbulent production during flow reversal in a stratified oscillating boundary layer on a sloping of Texas at Austin, Austin, Texas 78712, USA (Received 31 May 2013; accepted 10 October 2013; published of a uniformly stratified fluid. The radiated power PIW and kinetic energy density of the boundary currents

  5. Marine Tidal Current Electric Power Generation Technology: State of the Art and Current Status

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    resurgence in development of renewable ocean energy technology. Therefore, several demonstration projects appreciated as a vast renewable energy source. The energy is stored in oceans partly as thermal energy, partly categories: wave energy, marine and tidal current energy, ocean thermal energy, energy from salinity

  6. Status of Wave and Tidal Power Technologies for the United States

    SciTech Connect (OSTI)

    Musial, W.

    2008-08-01T23:59:59.000Z

    This paper presents the status of marine applications for renewable energy as of 2008 from a U.S. perspective. Technologies examined include wave, tidal, and ocean current energy extraction devices.

  7. Regulation of Tidal and Wave Energy Projects (Maine)

    Broader source: Energy.gov [DOE]

    State regulation of tidal and wave energy projects is covered under the Maine Waterway Development and Conservation Act (MWDCA), and complements regulation by the Federal Energy Regulation...

  8. Hydrodynamic analysis of a vertical axis tidal current turbine 

    E-Print Network [OSTI]

    Gretton, Gareth I.

    2009-01-01T23:59:59.000Z

    Tidal currents can be used as a predictable source of sustainable energy, and have the potential to make a useful contribution to the energy needs of the UK and other countries with such a resource. One of the technologies ...

  9. Tidal waves as yrast states in transitional nuclei

    E-Print Network [OSTI]

    S. Frauendorf; Y. Gu; J. Sun

    2010-02-16T23:59:59.000Z

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

  10. Integration of Wave and Tidal Power into the Haida Gwaii Electrical Grid

    E-Print Network [OSTI]

    Victoria, University of

    Integration of Wave and Tidal Power into the Haida Gwaii Electrical Grid by Susan Margot Boronowski Committee Integration of Wave and Tidal Power into the Haida Gwaii Electrical Grid by Susan Margot, Canada that relies heavily on diesel fuel for energy generation. An investigation is done

  11. Cross-shore sediment transport and the equilibrium morphology of mudflats under tidal currents

    E-Print Network [OSTI]

    Hogg, Andrew

    Cross-shore sediment transport and the equilibrium morphology of mudflats under tidal currents D of suspended sediment transport under cross-shore tidal currents on an intertidal mudflat. We employ a Lagrangian formulation to obtain periodic solutions for the sediment transport over idealized bathymetries

  12. New methodologies and scenarios for evaluating tidal current energy potential 

    E-Print Network [OSTI]

    Sankaran Iyer, Abhinaya

    2012-06-25T23:59:59.000Z

    Transition towards a low carbon economy raises concerns of loss of security of supply with high penetrations of renewable generation displacing traditional fossil fuel based generation. While wind and wave resources are ...

  13. Waves on unsteady currents Merrick C. Haller

    E-Print Network [OSTI]

    Haller, Merrick

    Waves on unsteady currents Merrick C. Haller School of Civil and Construction Engineering, Oregon 2007; published online 3 December 2007 Models for surface gravity wave propagation in the presence of currents often assume the current field to be quasi-stationary, which implies that the absolute wave

  14. Feasibility of Tidal and Ocean Current Energy in False Pass, Aleutian Islands, Alaska FINAL REPORT

    SciTech Connect (OSTI)

    Wright, Bruce Albert [Aleutian Pribilof Islands Association] [Aleutian Pribilof Islands Association

    2014-05-07T23:59:59.000Z

    The Aleutian Pribilof Islands Association was awarded a U.S. Department of Energy Tribal Energy Program grant (DE-EE0005624) for the Feasibility of Tidal and Ocean Current Energy in False Pass, Aleutian Islands, Alaska (Project). The goal of the Project was to perform a feasibility study to determine if a tidal energy project would be a viable means to generate electricity and heat to meet long-term fossil fuel use reduction goals, specifically to produce at least 30% of the electrical and heating needs of the tribally-owned buildings in False Pass. The Project Team included the Aleut Region organizations comprised of the Aleutian Pribilof Island Association (APIA), and Aleutian Pribilof Island Community Development Association (APICDA); the University of Alaska Anchorage, ORPC Alaska a wholly-owned subsidiary of Ocean Renewable Power Company (ORPC), City of False Pass, Benthic GeoScience, and the National Renewable Energy Laboratory (NREL). The following Project objectives were completed: collected existing bathymetric, tidal, and ocean current data to develop a basic model of current circulation at False Pass, measured current velocities at two sites for a full lunar cycle to establish the viability of the current resource, collected data on transmission infrastructure, electrical loads, and electrical generation at False Pass, performed economic analysis based on current costs of energy and amount of energy anticipated from and costs associated with the tidal energy project conceptual design and scoped environmental issues. Utilizing circulation modeling, the Project Team identified two target sites with strong potential for robust tidal energy resources in Isanotski Strait and another nearer the City of False Pass. In addition, the Project Team completed a survey of the electrical infrastructure, which identified likely sites of interconnection and clarified required transmission distances from the tidal energy resources. Based on resource and electrical data, the Project Team developed a conceptual tidal energy project design utilizing ORPC’s TidGen® Power System. While the Project Team has not committed to ORPC technology for future development of a False Pass project, this conceptual design was critical to informing the Project’s economic analysis. The results showed that power from a tidal energy project could be provided to the City of False at a rate at or below the cost of diesel generated electricity and sold to commercial customers at rates competitive with current market rates, providing a stable, flat priced, environmentally sound alternative to the diesel generation currently utilized for energy in the community. The Project Team concluded that with additional grants and private investment a tidal energy project at False Pass is well-positioned to be the first tidal energy project to be developed in Alaska, and the first tidal energy project to be interconnected to an isolated micro grid in the world. A viable project will be a model for similar projects in coastal Alaska.

  15. An Introduction to Wave-Current Interactions

    E-Print Network [OSTI]

    Smith, Jerome A.

    -scale wave focusing across a storm can re-direct the wind-stress? #12;1. Adiabatic interaction StartAn Introduction to Wave-Current Interactions Jerry Smith, MPL-SIO-UCSD jasmith@ucsd.edu http just want to hold up your hand. #12;Some Questions in Wave-Current Interaction Physics 1. Adiabatic

  16. CURRENTS DRIVEN BY ELECTRON CYCLOTRON WAVES

    E-Print Network [OSTI]

    Karney, Charles

    CURRENTS DRIVEN BY ELECTRON CYCLOTRON WAVES C.F.F. KARNEY, NJ. FISCH Plasma Physics Laboratory of the generation of steady-state currents by electron cyclotron waves are explored. A numerical solution of electron cyclotron wave absorption appears to be one of the more promising schemes of providing a steady

  17. A comparison of measured and modeled tidal currents in the Gulf of Maine

    E-Print Network [OSTI]

    Cook, Michael S

    1990-01-01T23:59:59.000Z

    to the persistence of the clockwise circulation around the Bank (Garrett er al. , 1978). Loder (1980) has shown theoretically that rectification of the strong semidiurnal tidal current across the steeply sloping northern edge of Georges Bank can produce a... astronomical forcing (Garrett, 1972; Brown and Moody, 1987). Garrett (1972) estimated the natural period of the Gulf of Maine-Bay of Fundy basin to be 13. 3M. 4 hours, which is near the frequency of the semidiurnal tidal constituents. Since the M2 semidiurnal...

  18. Overview of Ocean Wave and Tidal Energy Lingchuan Mei

    E-Print Network [OSTI]

    Lavaei, Javad

    resources such as solar and wind energy, waves and tides have the advantages of having much higher power stronger energy conversion devices lower in capital cost than for other renewable technologies and creating more job opportunities. For these major benefits the marine energy can provide us with, a great

  19. Hydropower, Wave and Tidal Technologies - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickr FlickrGuidedCH2MLLCBasics Hydropower Basics ContentHydropower, Wave

  20. Three-dimensional Numerical Analysis on Blade Response of Vertical Axis Tidal Current Turbine Under Operational Condition

    SciTech Connect (OSTI)

    Li, Ye; Karri, Naveen K.; Wang, Qi

    2014-04-30T23:59:59.000Z

    Tidal power as a large-scale renewable source of energy has been receiving significant attention recently because of its advantages over the wind and other renewal energy sources. The technology used to harvest energy from tidal current is called a tidal current turbine. Though some of the principles of wind turbine design are applicable to tidal current turbines, the design of latter ones need additional considerations like cavitation damage, corrosion etc. for the long-term reliability of such turbines. Depending up on the orientation of axis, tidal current turbines can be classified as vertical axis turbines or horizontal axis turbines. Existing studies on the vertical axis tidal current turbine focus more on the hydrodynamic aspects of the turbine rather than the structural aspects. This paper summarizes our recent efforts to study the integrated hydrodynamic and structural aspects of the vertical axis tidal current turbines. After reviewing existing methods in modeling tidal current turbines, we developed a hybrid approach that combines discrete vortex method -finite element method that can simulate the integrated hydrodynamic and structural response of a vertical axis turbine. This hybrid method was initially employed to analyze a typical three-blade vertical axis turbine. The power coefficient was used to evaluate the hydrodynamic performance, and critical deflection was considered to evaluate the structural reliability. A sensitivity analysis was also conducted with various turbine height-to-radius ratios. The results indicate that both the power output and failure probability increase with the turbine height, suggesting a necessity for optimal design. An attempt to optimize a 3-blade vertical axis turbine design with hybrid method yielded a ratio of turbine height to radius (H/R) about 3.0 for reliable maximum power output.

  1. Structural Design of a Horizontal-Axis Tidal Current Turbine Composite Blade

    SciTech Connect (OSTI)

    Bir, G. S.; Lawson, M. J.; Li, Y.

    2011-10-01T23:59:59.000Z

    This paper describes the structural design of a tidal composite blade. The structural design is preceded by two steps: hydrodynamic design and determination of extreme loads. The hydrodynamic design provides the chord and twist distributions along the blade length that result in optimal performance of the tidal turbine over its lifetime. The extreme loads, i.e. the extreme flap and edgewise loads that the blade would likely encounter over its lifetime, are associated with extreme tidal flow conditions and are obtained using a computational fluid dynamics (CFD) software. Given the blade external shape and the extreme loads, we use a laminate-theory-based structural design to determine the optimal layout of composite laminas such that the ultimate-strength and buckling-resistance criteria are satisfied at all points in the blade. The structural design approach allows for arbitrary specification of the chord, twist, and airfoil geometry along the blade and an arbitrary number of shear webs. In addition, certain fabrication criteria are imposed, for example, each composite laminate must be an integral multiple of its constituent ply thickness. In the present effort, the structural design uses only static extreme loads; dynamic-loads-based fatigue design will be addressed in the future. Following the blade design, we compute the distributed structural properties, i.e. flap stiffness, edgewise stiffness, torsion stiffness, mass, moments of inertia, elastic-axis offset, and center-of-mass offset along the blade. Such properties are required by hydro-elastic codes to model the tidal current turbine and to perform modal, stability, loads, and response analyses.

  2. Analysis of tidal current observations over the northeastern shelf of the Gulf of Mexico

    E-Print Network [OSTI]

    Durham, Donald L

    1967-01-01T23:59:59.000Z

    ANALYSIS OF TIDAL CURRENT OBSERVATIONS OVER THE NORTHEASTERN SHELF OF THE GULF OF MEXICO A Thesis By DONALD LEE DURHAM Submitted to the Graduate College of the Texas A&M University in partial fulfillment of the requirements for the degree... by Project 286 of the Texas A&M Research Foundation; this project is sponsored by the Office of Naval Research under Contract Nonr 2119(04). The Texas State Fellowship which was granted to me by the Graduate College of Texas A&M University...

  3. Fast wave current drive in DEMO

    SciTech Connect (OSTI)

    Lerche, E.; Van Eestera, D.; Messiaen, A. [Association EURATOM-Belgian State, LPP-ERM/KMS, TEC partner, Brussels (Belgium); Franke, T. [Max-Planck-Institut für Plasmaphysik, EURATOM-Assoziation, Garching (Germany); Collaboration: EFDA-PPPT Contributors

    2014-02-12T23:59:59.000Z

    The ability to non-inductively drive a large fraction of the toroidal plasma current in magnetically confined plasmas is an essential requirement for steady state fusion reactors such as DEMO. Besides neutral beam injection (NBI), electron-cyclotron resonance heating (ECRH) and lower hybrid wave heating (LH), ion-cyclotron resonance heating (ICRH) is a promising candidate to drive current, in particular at the high temperatures expected in fusion plasmas. In this paper, the current drive (CD) efficiencies calculated with coupled ICRF wave / CD numerical codes for the DEMO-1 design case (R{sub 0}=9m, B{sub 0}=6.8T, a{sub p}=2.25m) [1] are presented. It will be shown that although promising CD efficiencies can be obtained in the usual ICRF frequency domain (20-100MHz) by shifting the dominant ion-cyclotron absorption layers to the high-field side, operation at higher frequencies (100-300MHz) has a stronger CD potential, provided the parasitic RF power absorption of the alpha particles can be minimized.

  4. Experimental study of a single riser in waves and currents

    E-Print Network [OSTI]

    Guerandel, Vincent Louis Pierre

    1994-01-01T23:59:59.000Z

    This research study focused on wave-current interaction with a single, flexible cylinder representative of a riser in 500 in (1640 ft) of water. Realistic environmental conditions were obtained by combining wave and current conditions which were...

  5. Field Measurements at River and Tidal Current Sites for Hydrokinetic Energy Development: Best Practices Manual

    SciTech Connect (OSTI)

    Neary, Vincent S [ORNL; Gunawan, Budi [Oak Ridge National Laboratory (ORNL)

    2011-09-01T23:59:59.000Z

    In this report, existing data collection techniques and protocols for characterizing open channel flows are reviewed and refined to further address the needs of the MHK industry. The report provides an overview of the hydrodynamics of river and tidal channels, and the working principles of modern acoustic instrumentation, including best practices in remote sensing methods that can be applied to hydrokinetic energy site characterization. Emphasis is placed upon acoustic Doppler velocimeter (ADV) and acoustic-Doppler current profiler (ADCP) instruments, as these represent the most practical and economical tools for use in the MHK industry. Incorporating the best practices as found in the literature, including the parameters to be measured, the instruments to be deployed, the instrument deployment strategy, and data post-processing techniques. The data collected from this procedure aims to inform the hydro-mechanical design of MHK systems with respect to energy generation and structural loading, as well as provide reference hydrodynamics for environmental impact studies. The standard metrics and protocols defined herein can be utilized to guide field experiments with MHK systems.

  6. Water gate array for current flow or tidal movement pneumatic harnessing system

    DOE Patents [OSTI]

    Gorlov, Alexander M. (Brookline, MA)

    1991-01-01T23:59:59.000Z

    The invention, which provides a system for harnessing power from current flow or tidal movement in a body of water, comprises first and second hydro-pneumatic chambers each having ingress and egress below the water surface near the river or ocean floor and water gates operative to open or seal the ports to the passage of water. In an exemplary embodiment, the gates are sychronized by shafts so that the ingress ports of each chamber are connected to the egress ports of each other chamber. Thus, one set of gates is closed, while the other is open, thereby allowing water to flow into one chamber and build air pressure therein and allowing water to flow out of the other chamber and create a partial vacuum therein. A pipe connects the chambers, and an air turbine harnesses the air movement within the pipe. When water levels are equilibrated, the open set of gates is closed by a counterweight, and the other set is allowed to open by natural force of the water differential. The water gates may be comprised of a plurality of louvers which are ganged for simultaneous opening and closing. The system is designed to operate with air turbines or other pneumatic devices. Its design minimizes construction cost and environmental impact, yet provides a clean renewable energy source.

  7. Tidal Waves -- a non-adiabatic microscopic description of the yrast states in near-spherical nuclei

    E-Print Network [OSTI]

    S. Frauendorf; Y. Gu; J. Sun

    2011-09-08T23:59:59.000Z

    The yrast states of nuclei that are spherical or weakly deformed in their ground states are described as quadrupole waves running over the nuclear surface, which we call "tidal waves". The energies and E2 transition probabilities of the yrast states in nuclides with $Z$= 44, 46, 48 and $N=56, ~58,..., 66$ are calculated by means of the cranking model in a microscopic way. The nonlinear response of the nucleonic orbitals results in a strong coupling between shape and single particle degrees of freedom.

  8. Fully nonlinear wave-current interactions and kinematics by a BEM-based numerical wave tank

    E-Print Network [OSTI]

    Lynett, Patrick

    Fully nonlinear wave-current interactions and kinematics by a BEM-based numerical wave tank S. Ryu and the resulting kinematics. In the present paper, the variation of wave amplitude and wave length and minimize wave reflections from the down- stream wall. Nonlinear wave kinematics as a result of nonlinear

  9. Responses of an articulated loading platform in waves and currents

    E-Print Network [OSTI]

    Ran, Zhihuang

    1993-01-01T23:59:59.000Z

    The responses of an articulated loading platform (ALP) in regular and irregular unidirectional waves (with or without currents) are investigated both in frequency and time domain. The first- and second-order wave diffraction radiation are solved...

  10. Asymmetry of Tidal Plume Fronts in an Eastern Boundary Current Regime

    E-Print Network [OSTI]

    Jay, David

    water mass. This vorticity controls the transition of the tidal plume 2 #12;front to a subcritical state bulge, which in turn is embedded in far-field plume and coastal waters. Because of the mixing caused on its upwind or northern side) and marks a transition from supercritical to subcritical flow for 6

  11. Electron Bernstein wave current drive modeling in toroidal plasma confinement

    E-Print Network [OSTI]

    Decker, Joan, 1977-

    2005-01-01T23:59:59.000Z

    The steady-state confinement of tokamak plasmas in a fusion reactor requires non-inductively driven toroidal currents. Radio frequency waves in the electron cyclotron (EC) range of frequencies can drive localized currents ...

  12. Wave-current interaction in water of finite depth

    E-Print Network [OSTI]

    Huang, Zhenhua, 1967-

    2004-01-01T23:59:59.000Z

    In this thesis, the nonlinear interaction of waves and current in water of finite depth is studied. Wind is not included. In the first part, a 2D theory for the wave effect on a turbulent current over rough or smooth bottom ...

  13. Penetration of lower hybrid current drive waves in tokamaks

    SciTech Connect (OSTI)

    Horton, W. [The University of Texas at Austin, Austin, Texas 78712 (United States) [The University of Texas at Austin, Austin, Texas 78712 (United States); Aix-Marseille University, 58, Bd Charles Livon, 13284 Marseille (France); Goniche, M.; Peysson, Y.; Decker, J.; Ekedahl, A.; Litaudon, X. [CEA, IRFM, F-13108 Saint-Paul-Lez Durance (France)] [CEA, IRFM, F-13108 Saint-Paul-Lez Durance (France)

    2013-11-15T23:59:59.000Z

    Lower hybrid (LH) ray propagation in toroidal plasma is shown to be controlled by combination of the azimuthal spectrum launched by the antenna, the poloidal variation of the magnetic field, and the scattering of the waves by the drift wave fluctuations. The width of the poloidal and radial radio frequency wave spectrum increases rapidly as the rays penetrate into higher density and scatter from the drift waves. The electron temperature gradient (ETG) spectrum is particularly effective in scattering the LH waves due to its comparable wavelengths and phase velocities. ETG turbulence is also driven by the radial gradient of the electron current profile giving rise to an anomalous viscosity spreading the LH driven plasma currents. The LH wave scattering is derived from a Fokker-Planck equation for the distribution of the ray trajectories with diffusivities derived from the drift wave fluctuations. The condition for chaotic diffusion for the rays is derived. The evolution of the poloidal and radial mode number spectrum of the lower hybrid waves are both on the antenna spectrum and the spectrum of the drift waves. Antennas launching higher poloidal mode number spectra drive off-axis current density profiles producing negative central shear [RS] plasmas with improved thermal confinement from ETG transport. Core plasma current drive requires antennas with low azimuthal mode spectra peaked at m = 0 azimuthal mode numbers.

  14. The giant star of the symbiotic system YY Her: Rotation, Tidal wave, Solar-type cycle and Spots

    E-Print Network [OSTI]

    Liliana Formiggini; Elia M. Leibowitz

    2006-09-17T23:59:59.000Z

    We analyze the historical light curve of the symbiotic star YY Her, from 1890 up to December 2005. A secular declining trend is detected, at a rate of ~.01 magn in 1000 d, suggesting that the system could belong to the sub-class of symbiotic novae. Several outburst events are superposed on this slow decline. Three independent periodicities are identified in the light curve. A quasi-periodicity of 4650.7 d is detected for the outburst occurrence. We suggest that it is a signature of a solar-type magnetic dynamo cycle in the giant component. A period of 593.2 d modulates the quiescent light curve and it is identified as the binary period of the system. During outburst events the system shows a stable periodic oscillation of 551.4 d. We suggest that it is the rotation period of the giant.The secondary minima detected at some epochs of quiescence are probably due to dark spots on the surface of the rotating giant. The difference between the frequencies of these two last periods is the frequency of a tidal wave in the outer layers of the giant. A period which is a beat between the magnetic cycle and the tidal wave period is also apparent in the light curve. YY Her is a third symbiotic system exhibiting these cycles in their light curve, suggesting that a magnetic dynamo process is prevalent in the giant components of symbiotic stars, playing an important role in the outburst mechanism of some of these systems.

  15. WaveCurrent Interactions in Finite Depth JEROME A. SMITH

    E-Print Network [OSTI]

    Smith, Jerome A.

    Wave­Current Interactions in Finite Depth JEROME A. SMITH Scripps Institution of Oceanography, La (Longuet-Higgins 1969; Hasselmann 1971; Garrett and Smith 1976; and many others). In particular, Hassel) changes in wave momentum that absorb some of the radiation stress gradients. Garrett and Smith (1976

  16. Experimental Wave Tank Test for Reference Model 3 Floating-Point...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    marine and hydrokinetic technologies including current (tidal, open-ocean, and river) turbines and wave energy converters. The objectives of the project were to 1) evaluate the...

  17. Turbulent Flow and Transport Modeling by Long Waves and Currents

    E-Print Network [OSTI]

    Kim, Dae Hong

    2010-10-12T23:59:59.000Z

    This dissertation presents models for turbulent flow and transport by currents and long waves in large domain. From the Navier-Stokes equations, a fully nonlinear depth-integrated equation model for weakly dispersive, turbulent and rotational flow...

  18. Development and Verification of a Computational Fluid Dynamics Model of a Horizontal-Axis Tidal Current Turbine

    SciTech Connect (OSTI)

    Lawson, M. J.; Li, Y.; Sale, D. C.

    2011-10-01T23:59:59.000Z

    This paper describes the development of a computational fluid dynamics (CFD) methodology to simulate the hydrodynamics of horizontal-axis tidal current turbines. Qualitative measures of the CFD solutions were independent of the grid resolution. Conversely, quantitative comparisons of the results indicated that the use of coarse computational grids results in an under prediction of the hydrodynamic forces on the turbine blade in comparison to the forces predicted using more resolved grids. For the turbine operating conditions considered in this study, the effect of the computational timestep on the CFD solution was found to be minimal, and the results from steady and transient simulations were in good agreement. Additionally, the CFD results were compared to corresponding blade element momentum method calculations and reasonable agreement was shown. Nevertheless, we expect that for other turbine operating conditions, where the flow over the blade is separated, transient simulations will be required.

  19. Interactions Between Tidal Flows and Ooid Shoals, Northern Bahamas

    E-Print Network [OSTI]

    Reeder, Stacy Lynn; Rankey, Gene C.

    2008-03-01T23:59:59.000Z

    active sand waves and ripples. Towards the platform margin, tidal currents pass through narrow inlets. The main inlet opening oceanward (NW) of the shoal stretches between two Pleistocene bedrock islands, connected by a bedrock high that extends... include both flood and ebb tidal deltas, with generally lobate forms, convex away from the islands, and with endpoints at the inlets. Although the inner portions of these lobes are mainly seagrass-stabilized muddy peloidal and skeletal sands with local...

  20. Fast wave current drive in DIII-D

    SciTech Connect (OSTI)

    Petty, C.C.; Callis, R.W.; Chiu, S.C.; deGrassie, J.S.; Forest, C.B.; Freeman, R.L.; Gohil, P.; Harvey, R.W.; Ikezi, H.; Lin-Liu, Y.-R. [and others

    1995-02-01T23:59:59.000Z

    The non-inductive current drive from fast Alfven waves launched by a directional four-element antenna was measured in the DIII-D tokamak. The fast wave frequency (60 MHz) was eight times the deuterium cyclotron frequency at the plasma center. An array of rf pickup loops at several locations around the torus was used to verify the directivity of the four-element antenna. Complete non-inductive current drive was achieved using a combination of fast wave current drive (FWCD) and electron cyclotron current drive (ECCD) in discharges for which the total plasma current was inductively ramped down from 400 to 170 kA. For discharges with steady plasma current, up to 110 kA of FWCD was inferred from an analysis of the loop voltage, with a maximum non-inductive current (FWCD, ECCD, and bootstrap) of 195 out of 310 kA. The FWCD efficiency increased linearly with central electron temperature. For low current discharges, the FWCD efficiency was degraded due to incomplete fast wave damping. The experimental FWCD was found to agree with predictions from the CURRAY ray-tracing code only when a parasitic loss of 4% per pass was included in the modeling along with multiple pass damping.

  1. Under consideration for publication in J. Fluid Mech. 1 Reflecting tidal wave beams and local

    E-Print Network [OSTI]

    generation of solitary waves in the ocean thermocline By T. R. A K Y L A S1, R. H. J. G R I M S H A W2, S. R ) It is generally accepted that ocean internal solitary waves can arise from the interaction of the barotropic tide owing to radiation into the lower fluid. De- pending on the intensity of the incident beam, nonlinear

  2. Current transport along grain boundaries in d-wave superconductors.

    SciTech Connect (OSTI)

    Carmody, M.; Marks, L. D.; Merkle, K. L.; Materials Science Division; Northwestern Univ.

    2002-05-01T23:59:59.000Z

    The use of a classic phase retrieval algorithm has been previously used to determine the local critical current J{sub c}(x) along the length of grain boundary Josephson junctions that can be characterized using a standard s-wave model. The phase retrieval approach has been modified for use with d-wave dominated superconductors to allow for negative local currents along the boundary. In general solutions to the 1-D phase problem are not unique, however in the present work special constraints are employed experimentally to ensure uniqueness. The various current distribution solutions and their possible uniqueness are explored. The solutions are consistent with most existing d-wave Josephson junction boundary models and can be used to understand the basic current distribution along 45 degree YaBa{sub 2}Cu{sub 3}O{sub 7-x} grain boundary junctions as well as providing a means for mapping the location of self-generated flux cores.

  3. Dispersion equation for water waves with vorticity and Stokes waves on flows with counter-currents

    E-Print Network [OSTI]

    Vladimir Kozlov; Nikolay Kuznetsov

    2014-06-05T23:59:59.000Z

    The two-dimensional free-boundary problem of steady periodic waves with vorticity is considered for water of finite depth. We investigate how flows with small-amplitude Stokes waves on the free surface bifurcate from a horizontal parallel shear flow in which counter-currents may be present. Two bifurcation mechanisms are described: for waves with fixed Bernoulli's constant and fixed wavelength. In both cases the corresponding dispersion equations serve for defining wavelengths from which Stokes waves bifurcate. Sufficient conditions guaranteeing the existence of roots of these equations are obtained. Two particular vorticity distributions are considered in order to illustrate general results.

  4. Predictions of fast wave heating, current drive, and current drive antenna arrays for advanced tokamaks

    SciTech Connect (OSTI)

    Batchelor, D.B.; Baity, F.W.; Carter, M.D. [and others

    1994-12-31T23:59:59.000Z

    The objective of the advanced tokamak program is to optimize plasma performance leading to a compact tokamak reactor through active, steady state control of the current profile using non-inductive current drive and profile control. To achieve these objectives requires compatibility and flexibility in the use of available heating and current drive systems--ion cyclotron radio frequency (ICRF), neutral beams, and lower hybrid. For any advanced tokamak, the following are important challenges to effective use of fast waves in various roles of direct electron heating, minority ion heating, and current drive: (1) to employ the heating and current drive systems to give self-consistent pressure and current profiles leading to the desired advanced tokamak operating modes; (2) to minimize absorption of the fast waves by parasitic resonances, which limit current drive; (3) to optimize and control the spectrum of fast waves launched by the antenna array for the required mix of simultaneous heating and current drive. The authors have addressed these issues using theoretical and computational tools developed at a number of institutions by benchmarking the computations against available experimental data and applying them to the specific case of TPX.

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-Up fromDepartmentTie Ltd: Scope Change #1Impacts | Department of Energyof Contractand

  6. Wave–current interaction in the presence of a three-dimensional bathymetry: Deep water wave focusing in opposing current conditions

    SciTech Connect (OSTI)

    Rey, V., E-mail: rey@univ-tln.fr; Charland, J., E-mail: jenna.charland@univ-tln.fr; Touboul, J., E-mail: julien.touboul@univ-tln.fr [Université de Toulon, CNRS/INSU, IRD, Mediterranean Institute of Oceanography (MIO), UM 110, F-83957 La Garde (France); Aix Marseille Université, CNRS/INSU, IRD, Mediterranean Institute of Oceanography (MIO), UM 110, 13288 Marseille, Cedex (France)

    2014-09-15T23:59:59.000Z

    Large scale experiments were carried out in the Ocean Engineering Basin FIRST, France. A tri-dimensional bathymetry consisting of two symmetrical submerged mounds was displayed on the flat bed on both sides of the basin. Regular waves of frequency corresponding to deep water conditions above the bathymetry were generated in opposing current conditions. A strong tri-dimensional behaviour is observed for the wave amplitude, leading to a strong focusing (up to twice the incident amplitude) of the wave energy towards the central deeper zone. This amplification cannot be ascribed to the increase of the current intensity in the main wave direction, nor to a current gradient normally to the wave direction. A wave phase gradient, normal to its main direction, is observed up-wave (or downstream) the mounds. This phase lag depends on the wave amplitude, it is the higher for the moderate amplitude case. The experimental data are compared with calculations of a refraction-diffraction model assuming a depth-averaged current. If the model qualitatively predicts the wave amplification in the centerline of the basin, discrepancies are observed in the vicinity of the depth changes. The observed mean current vertical profile shape is then supposed to play a significant role in the wave focusing, especially near the steep slopes down-stream the mounds. In addition, the waves are found to modify substantially both horizontal and vertical current fields.

  7. Hydraulic properties of an artificial tidal inlet through a Texas barrier beach

    E-Print Network [OSTI]

    Prather, Stanley Harold

    1972-01-01T23:59:59.000Z

    . These littoral barriers are depositional structures continually changed by waves, tidal currents, and winds. Often the only connections between the open ocean and the bays are small restricted channels through the barrier beaches. These chan- nels, or tidal... too large on wide barrier beaches to permit sufficient scour. Breakthroughs also have been found to be caused by gradual buildups of water in the bays, followed by wind shifts to an off. ? shore direction (27). This tends to be supported by Price...

  8. Wave-current Interaction and Its Impact on Contaminant Transport Primary Investigator: Meng Xia

    E-Print Network [OSTI]

    Wave-current Interaction and Its Impact on Contaminant Transport Primary Investigator: Meng Xia Co Overview This project is designed to develop a three-dimensional coupled Wave-current model that can simulate and predict wave effects on the structure of currents, water level fluctuations, sediments

  9. Surface current effects on the fetch-limited growth of wave energy Brian K. Haus1

    E-Print Network [OSTI]

    Miami, University of

    Surface current effects on the fetch-limited growth of wave energy Brian K. Haus1 Received 5 the fetch-limited growth of wind wave energy over a region with significant lateral shear of the current. Both the near-surface currents and wave energy and period were mapped over the highly sheared inshore

  10. Wave Energy Converter (WEC) Array Effects on Wave Current and Sediment Circulation: Monterey Bay CA.

    SciTech Connect (OSTI)

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

    2014-09-01T23:59:59.000Z

    The goal s of this study were to develop tools to quantitatively characterize environments where wave energy converter ( WEC ) devices may be installed and to assess e ffects on hydrodynamics and lo cal sediment transport. A large hypothetical WEC array was investigated using wave, hydrodynamic, and sediment transport models and site - specific average and storm conditions as input. The results indicated that there were significant changes in sediment s izes adjacent to and in the lee of the WEC array due to reduced wave energy. The circulation in the lee of the array was also altered; more intense onshore currents were generated in the lee of the WECs . In general, the storm case and the average case show ed the same qualitative patterns suggesting that these trends would be maintained throughout the year. The framework developed here can be used to design more efficient arrays while minimizing impacts on nearshore environmen ts.

  11. Wave-current interaction in strongly sheared mean flows Zhifei Dong and James T. Kirby

    E-Print Network [OSTI]

    Kirby, James T.

    Wave-current interaction in strongly sheared mean flows Zhifei Dong and James T. Kirby Center@udel.edu Abstract We describe a framework for wave-current interaction theory for small-amplitude surface gravity waves propagating on the strongly sheared mean flows. Using a multiple-scale perturbation method, we

  12. Estimate of Extreme Wind, Wave, Surge, and Current Conditions Wilmington Canyon Integrated Design Project

    E-Print Network [OSTI]

    Firestone, Jeremy

    1 Estimate of Extreme Wind, Wave, Surge, and Current Conditions for the Wilmington Canyon. In order to estimate loads during extreme wind and wave events, these events must be defined. The design. This paper does not treat wave spectral analysis, extreme wind shear, veer, clocking, turbulence intensity

  13. Turbulent combined wave-current boundary layer model for application in coastal waters

    E-Print Network [OSTI]

    Humbyrd, Chelsea Joy

    2012-01-01T23:59:59.000Z

    Accurately predicting transport processes, including sediment transport, in the coastal environment is impossible without correct current velocity and shear stress information. A combined wave-current boundary layer theory ...

  14. Simultaneous wave and current forces on a cylinder near the bottom boundary

    E-Print Network [OSTI]

    Knoll, David Alex

    1979-01-01T23:59:59.000Z

    - ing Program and Professor R. O. Raid for their review of this thesis. Special thanks are due to Mrs. Lori Baldwin, Mr. and Mrs. Ron Watanabe and Mr, Kenneth Kim for their co-operation in the preparation of the manuscript. TABLE OF CONTENTS Chapter... Potential of Combined Wave and Current = Velocity Potential of Wave = Velocity Potential of Current Surface Density Spectrum = Velocity Density Spectrum Acceleration Density Spectrum p Density of Fluid v ~ Kinematic Viscosity &o Wave Prequency &uq...

  15. A Bistatic Phased-Array Doppler Sonar for WaveCurrent Research JEROME A. SMITH

    E-Print Network [OSTI]

    Buckingham, Michael

    A Bistatic Phased-Array Doppler Sonar for Wave­Current Research JEROME A. SMITH Scripps Institution; Smith 2006a). In this last case, a discrepancy was identified: the measured response at the surface given below, see Smith (2006a); for a discussion of the wave groups re- sponsible, see Smith

  16. Numerical simulation of inviscid wave-current interaction with an FPSO

    E-Print Network [OSTI]

    Bae, Sang-Yun

    2009-05-15T23:59:59.000Z

    This study investigated Floating Production Storage and Offloading (FPSO) responses under wave and current interactions. A higher order boundary element method (HOBEM) was adopted to probe the behavior of an FPSO. Forces and moment of an FPSO were...

  17. Dynamic control of spin wave spectra using spin-polarized currents

    SciTech Connect (OSTI)

    Wang, Qi; Zhang, Huaiwu, E-mail: hwzhang@uestc.edu.cn; Tang, Xiaoli; Bai, Feiming; Zhong, Zhiyong, E-mail: zzy@uestc.edu.cn [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China); Fangohr, Hans [Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom)

    2014-09-15T23:59:59.000Z

    We describe a method of controlling the spin wave spectra dynamically in a uniform nanostripe waveguide through spin-polarized currents. A stable periodic magnetization structure is observed when the current flows vertically through the center of nanostripe waveguide. After being excited, the spin wave is transmitted at the sides of the waveguide. Numerical simulations of spin-wave transmission and dispersion curves reveal a single, pronounced band gap. Moreover, the periodic magnetization structure can be turned on and off by the spin-polarized current. The switching process from full rejection to full transmission takes place within less than 3?ns. Thus, this type magnonic waveguide can be utilized for low-dissipation spin wave based filters.

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

    SciTech Connect (OSTI)

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

    2014-01-15T23:59:59.000Z

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

  19. 9/18/09 2:43 PM'Big Wave' Theory Offers Alternative to Dark Energy // Current Page 1 of 11http://current.com/items/90718274_big-wave-theory-offers-alternative-to-dark-energy.htm

    E-Print Network [OSTI]

    Temple, Blake

    9/18/09 2:43 PM'Big Wave' Theory Offers Alternative to Dark Energy // Current Page 1 of 11http://current.com/items/90718274_big-wave-theory-offers-alternative-to-dark-energy.htm login | register |home tv shows schedule to Dark Energy // Current Page 2 of 11http://current.com/items/90718274_big-wave-theory-offers-alternative-to-dark-energy

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

    E-Print Network [OSTI]

    Brest, Université de

    's excessive energy demand. An extremely abundant and promising source of energy exists in oceans. Currently be included in one of the following categories: wave energy, marine and tidal current energy, ocean thermalA Predictive power control of Doubly Fed Induction Generator for Wave Energy Converter in Irregular

  1. Forces due to waves in the presence of currents on a submerged model structure

    E-Print Network [OSTI]

    Shields, David Ray

    1985-01-01T23:59:59.000Z

    OF SCIENCE December 1985 Major Subject: Ocean Engineering FORCES DUE TO WAVES IN THE PRESENCE OF CURRENTS ON A SUBMERGED MODEL STRUCTURE A Thesis by DAVID RAY SHIELDS Approved as to style and content by: Jo n . Her &c (Chairman of Committee) K... Engineering Program of the Civil Engineering Department for the use of its wave tank and instrumentation to perform this research. A much needed 8-channel recorder was provided through the courtesy of the Mechanical Engineering Department. A Texas A...

  2. High efficiency off-axis current drive by high frequency fast waves

    SciTech Connect (OSTI)

    Prater, R.; Pinsker, R. I.; Moeller, C. P. [General Atomics, PO Box 85608, San Diego, California 92186-5608 (United States); Porkolab, M.; Vdovin, V. [Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139 (United States)

    2014-02-12T23:59:59.000Z

    Modeling work shows that current drive can be done off-axis with high efficiency, as required for FNSF and DEMO, by using very high harmonic fast waves (“helicons” or “whistlers”). The modeling indicates that plasmas with high electron beta are needed in order for the current drive to take place off-axis, making DIII-D a highly suitable test vehicle for this process. The calculations show that the driven current is not very sensitive to the launched value of n{sub ?}, a result that can be understood from examination of the evolution of n{sub ?} as the waves propagate in the plasma. Because of this insensitivity, relatively large values (?3) of n{sub ?} can be launched, thereby avoiding some of the problems with mode conversion in the boundary found in some previous experiments. Use of a traveling wave antenna provides a very narrow n{sub ?} spectrum, which also helps avoid mode conversion.

  3. Filamentation instability of current-driven dust ion-acoustic waves in a collisional dusty plasma

    SciTech Connect (OSTI)

    Niknam, A. R. [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran 19839-63113 (Iran, Islamic Republic of); Haghtalab, T.; Khorashadizadeh, S. M. [Physics Department, Birjand University, Birjand 97179-63384 (Iran, Islamic Republic of)

    2011-11-15T23:59:59.000Z

    A theoretical investigation has been made of the dust ion-acoustic filamentation instability in an unmagnetized current-driven dusty plasma by using the Lorentz transformation formulas. The effect of collision between the charged particles with neutrals and their thermal motion on this instability is considered. Developing the filamentation instability of the current-driven dust ion-acoustic wave allows us to determine the period and the establishment time of the filamentation structure and threshold for instability development.

  4. Theory of magnetospheric hydromagnetic waves excited by energetic ring-current protons

    SciTech Connect (OSTI)

    Chen, Liu; Hasegawa, Akira

    1987-06-01T23:59:59.000Z

    A general theoretical formulation, allowing finite ion Larmor radii, general magnetic field geometries and plasma equilibria, has been developed to investigate excitations of magnetohydrodynamic (MHD) Alfven waves within the earth's magnetosphere by the storm-time energetic ring-current protons. In particular, it is found that for adiabatically injected protons, various predicted instability properties are consistent with satellite observations. 8 refs.

  5. Wake II model for hydrodynamic forces on marine pipelines for the wave plus current case

    E-Print Network [OSTI]

    Ramirez Sabag, Said

    1999-01-01T23:59:59.000Z

    The concept of the Wake II model for the determination of the hydrodynamic forces on marine pipelines is extended to include the wave plus current case. There are two main differences between the Wake II and the traditional model that uses Morison...

  6. Measuring Program for Wind, Waves and Current for Horns Rev and Ls; Documentation

    E-Print Network [OSTI]

    REPORT Measuring Program for Wind, Waves and Current for Horns Rev and Lćsř; Documentation Documentation of wind sensors, data logs, etc. for Horns Rev is described in folder 2CF/EB001 supplied by ED is described in folder 2 CF/EB003 supplied by ED service centre and TW. Documentation of 3D Sonic Wind

  7. Turbidity current flow over an obstacle and phases of sediment wave generation

    E-Print Network [OSTI]

    Strauss, Moshe

    2011-01-01T23:59:59.000Z

    We study the flow of particle-laden turbidity currents down a slope and over an obstacle. A high-resolution 2D computer simulation model is used, based on the Navier-Stokes equations. It includes poly-disperse particle grain sizes in the current and substrate. Particular attention is paid to the erosion and deposition of the substrate particles, including application of an active layer model. Multiple flows are modeled from a lock release that can show the development of sediment waves (SW). These are stream-wise waves that are triggered by the increasing slope on the downstream side of the obstacle. The initial obstacle is completely erased by the resuspension after a few flows leading to self consistent and self generated SW that are weakly dependant on the initial obstacle. The growth of these waves is directly related to the turbidity current being self sustaining, that is, the net erosion is more than the net deposition. Four system parameters are found to influence the SW growth: (1) slope, (2) current ...

  8. Modeling the dynamics of tidally-interacting binary neutron stars up to merger

    E-Print Network [OSTI]

    Sebastiano Bernuzzi; Alessandro Nagar; Tim Dietrich; Thibault Damour

    2015-02-18T23:59:59.000Z

    The data analysis of the gravitational wave signals emitted by coalescing neutron star binaries requires the availability of an accurate analytical representation of the dynamics and waveforms of these systems. We propose an effective-one-body (EOB) model that describes the general relativistic dynamics of neutron star binaries from the early inspiral up to merger. Our EOB model incorporates an enhanced attractive tidal potential motivated by recent analytical advances in the post-Newtonian and gravitational self-force description of relativistic tidal interactions. No fitting parameters are introduced for the description of tidal interaction in the late, strong-field dynamics. We compare the model energetics and the gravitational wave phasing with new high-resolution multi-orbit numerical relativity simulations of equal-mass configurations with different equations of state. We find agreement within the uncertainty of the numerical data for all configurations. Our model is the first semi-analytical model which captures the tidal amplification effects close to merger. It thereby provides the most accurate analytical representation of binary neutron star dynamics and waveforms currently available.

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    energy resource plan. An extremely abundant and promising source of energy exists in oceans of the following categories: wave energy, marine and tidal current energy, ocean thermal energy, energy fromPredictive Power Control of Doubly-Fed Induction Generator for Wave Energy Converters M.S. Lagoun1

  10. Power Smoothing and Limitation Control of a PMSG-Based Marine Current Turbine under Swell Waves

    E-Print Network [OSTI]

    Boyer, Edmond

    Power Smoothing and Limitation Control of a PMSG-Based Marine Current Turbine under Swell Waves la puissance maximale (MPPT) nécessiterait d'accélérer ou de décélérer fréquemment la turbine à par une turbine marine associée à un générateur synchrone à aimants permanents (GSAP). Un algorithme

  11. The role of linear and voltage-dependent ionic currents in the generation of slow wave oscillations

    E-Print Network [OSTI]

    Bose, Amitabha

    The role of linear and voltage-dependent ionic currents in the generation of slow wave oscillations voltages, re- spectively. Oscillations are created by inward currents driving the cell away from rest voltages and one outward current that repolarizes the cell. Such currents have traditionally been assumed

  12. Spectral analysis of the efficiency of vertical mixing in the deep ocean due to interaction of tidal currents with a ridge running down a continental slope

    SciTech Connect (OSTI)

    Ibragimov, Ranis N.; Tartakovsky, Alexandre M.

    2014-10-29T23:59:59.000Z

    Efficiency of mixing, resulting from the reflection of an internal wave field imposed on the oscillatory background flow with a three-dimensional bottom topography, is investigated using a linear approximation. The radiating wave field is associated with the spectrum of the linear model, which consists of those mode numbers n and slope values ?, for which the solution represents the internal waves of frequencies ? = n?0 radiating upwrad of the topography, where ?0 is the fundamental frequency at which internal waves are generated at the topography. The effects of the bottom topography and the earth’s rotation on the spectrum is analyzed analytically and numerically in the vicinity of the critical slope, which is a slope with the same angle to the horizontal as the internal wave characteristic. In this notation, ? is latitude, f is the Coriolis parameter and N is the buoyancy frequency, which is assumed to be a constant, which corresponds to the uniform stratification.

  13. Tidal heating and tidal evolution in the solar system

    E-Print Network [OSTI]

    Meyer, Jennifer Ann

    2011-01-01T23:59:59.000Z

    In this thesis, we examine the effects of tidal dissipation on solid bodies in application and in theory. First, we study the effects of tidal heating and tidal evolution in the Saturnian satellite system. We constrain the ...

  14. Tidal Wetlands Regulations (Connecticut)

    Broader source: Energy.gov [DOE]

    Most activities occurring in or near tidal wetlands are regulated, and this section contains information on such activities and required permit applications for proposed activities. Applications...

  15. Clarence Strait Tidal Energy Project, Tenax Energy Tropical Tidal...

    Open Energy Info (EERE)

    Test Centre, Jump to: navigation, search 1 Retrieved from "http:en.openei.orgwindex.php?titleClarenceStraitTidalEnergyProject,TenaxEnergyTropicalTidalTestCentre,&o...

  16. Scour around a group of circular piles caused by waves and currents

    E-Print Network [OSTI]

    Lee, Ta-Yang

    1983-01-01T23:59:59.000Z

    Major Subject: Ocean Engineering SCOUR AROUND A GROUP OF CIRCULAR PILES CAUSED BY WAVES AND CURRENTS A Thesis by TA-YANG LEE Approved as to style and content by: John B. Herbich (Chairman of Committee) Robert O. Reid (Member) Gi lio V... ) 50 10 FIG. 2. ? Critical shear stress for Quartz sediment in water as function of grain size 10 10 e a 1 V o 5 upper (tmit "1" 1 " m o 1 5 5 1 o So Mean Sediment Size& mm FIG. 3. ? Critical water velocities for Quartz sediment as function...

  17. Chaos and Tidal Capture

    E-Print Network [OSTI]

    Rosemary A. Mardling

    1995-12-07T23:59:59.000Z

    We review the tidal capture mechanism for binary formation, an important process in globular cluster cores and perhaps open cluster cores. Tidal capture binaries may be the precursors for some of the low-mass X-ray binaries observed in abundance in globular clusters. They may also play an important role in globular cluster dynamics. We summarize the chaos model for tidal interaction (Mardling 1995, ApJ, 450, 722, 732), and discuss how this affects our understanding of the circularization process which follows capture.

  18. Collaborative research: Dynamics of electrostatic solitary waves and their effects on current layers

    SciTech Connect (OSTI)

    Chen, Li-Jen

    2014-04-18T23:59:59.000Z

    The project has accomplished the following achievements including the goals outlined in the original proposal. Generation and measurements of Debye-scale electron holes in laboratory: We have generated by beam injections electron solitary waves in the LAPD experiments. The measurements were made possible by the fabrication of the state-of-the-art microprobes at UCLA to measure Debye-scale electric fields [Chiang et al., 2011]. We obtained a result that challenged the state of knowledge about electron hole generation. We found that the electron holes were not due to two-stream instability, but generated by a current-driven instability that also generated whistler-mode waves [Lefebvre et al., 2011, 2010b]. Most of the grant supported a young research scientist Bertrand Lefebvre who led the dissemination of the laboratory experimental results. In addition to two publications, our work relevant to the laboratory experiments on electron holes has resulted in 7 invited talks [Chen, 2007, 2009; Pickett et al., 2009a; Lefebvre et al., 2010a; Pickett et al., 2010; Chen et al., 2011c, b] (including those given by the co-I Jolene Pickett) and 2 contributed talks [Lefebvre et al., 2009b, a]. Discovery of elecctron phase-space-hole structure in the reconnection electron layer: Our theoretical analyses and simulations under this project led to the discovery of an inversion electric field layer whose phase-space signature is an electron hole within the electron diffusion layer in 2D anti-parallel reconnection [Chen et al., 2011a]. We carried out particle tracing studies to understand the electron orbits that result in the phase-space hole structure. Most importantly, we showed that the current density in the electron layer is limited in collisionless reconnection with negligible guide field by the cyclotron turning of meandering electrons. Comparison of electrostatic solitary waves in current layers observed by Cluster and in LAPD: We compared the ESWs observed in a supersubstorm by the Cluster spacecraft and those measured in LAPD. One of the similarities in the characteristics of ESWs observed in space and in LAPD is that the time duration tends to be approximately the inverse of the electron plasma frequency [Pickett et al., 2009b]. Discovery of suprathermal electron bursts inside a series of magnetic islands: Our effort in examining the roles of ESWs in reconnection current layers resulted in the serendipitous discovery that was published in Nature Physics. In earth’s magnetosphere, we observed through the measurements from the four Cluster spacecraft, a series of magnetic islands and suprathermal electron bursts within the islands. The islands were identified to be effectively acceleration sites for electrons [Chen et al., 2008, 2009].

  19. Modeling the dynamics of tidally-interacting binary neutron stars up to merger

    E-Print Network [OSTI]

    Sebastiano Bernuzzi; Alessandro Nagar; Tim Dietrich; Thibault Damour

    2014-12-15T23:59:59.000Z

    We propose an effective-one-body (EOB) model that describes the general relativistic dynamics of neutron star binaries from the early inspiral up to merger. Our EOB model incorporates an enhanced attractive tidal potential motivated by recent analytical advances in the post-Newtonian and gravitational self-force description of relativistic tidal interactions. No fitting parameters are introduced for the description of tidal interaction in the late, strong-field dynamics. We compare the model dynamics (described by the gauge invariant relation between binding energy and orbital angular momentum), and the gravitational wave phasing, with new high-resolution multi-orbit numerical relativity simulations of equal-mass configurations with different equations of state. We find agreement essentially within the uncertainty of the numerical data for all the configurations. Our model is the first semi-analytical model which captures the tidal amplification effects close to merger. It thereby provides the most accurate analytical representation of binary neutron star dynamics and waveforms currently available.

  20. TIDAL TURBULENCE SPECTRA FROM A COMPLIANT MOORING

    SciTech Connect (OSTI)

    Thomson, Jim; Kilcher, Levi; Richmond, Marshall C.; Talbert, Joe; deKlerk, Alex; Polagye, Brian; Guerra, Maricarmen; Cienfuegos, Rodrigo

    2013-06-13T23:59:59.000Z

    A compliant mooring to collect high frequency turbulence data at a tidal energy site is evaluated in a series of short demon- stration deployments. The Tidal Turbulence Mooring (TTM) improves upon recent bottom-mounted approaches by suspend- ing Acoustic Doppler Velocimeters (ADVs) at mid-water depths (which are more relevant to tidal turbines). The ADV turbulence data are superior to Acoustic Doppler Current Profiler (ADCP) data, but are subject to motion contamination when suspended on a mooring in strong currents. In this demonstration, passive stabilization is shown to be sufficient for acquiring bulk statistics of the turbulence, without motion correction. With motion cor- rection (post-processing), data quality is further improved; the relative merits of direct and spectral motion correction are dis- cussed.

  1. Harmonic oscillator with time-dependent effective-mass and frequency with a possible application to 'chirped tidal' gravitational waves forces affecting interferometric detectors

    E-Print Network [OSTI]

    Yacob Ben-Aryeh

    2008-07-29T23:59:59.000Z

    The general theory of time-dependent frequency and time-dependent mass ('effective mass') is described.The general theory for time-dependent harmonic- oscillator is applied in the present research for studying certain quantum effects in the interferometers for detecting gravitational waves.When an astronomical binary system approaches its point of coalescence the gravitational wave intensity and frequency are increasing and this can lead to strong deviations from the simple description of harmonic-oscillations for the interferometric masses on which the mirrors are placed.It is shown that under such condtions the harmonic-oscillations of these masses can be described by mechanical harmonic-oscillators with time-dependent frequency and effective-mass. In the present theoretical model the effective-mass is decreasing with time describing pumping phenomena in which the oscillator amplitude is increasing with time . The quantization of this system is analyzed by the use of the adiabatic approximation. It is found that the increase of the gravitational wave intensity, within the adiabatic approximation, leads to squeezing phenomena where the quantum noise in one quadrature is increased and in the other quadrature is decreased.

  2. THEORETICAL AND NUMERICAL STUDY OF WAVE-CURRENT INTERACTION IN STRONGLY-SHEARED FLOWS

    E-Print Network [OSTI]

    Kirby, James T.

    made to improve the wave effects as depth dependent radiation stress in ocean circulation model (Mellor to radiation stress (McWilliams et al. 2004). Both of these formulations have been applied in 3D coastal ocean wave train propagating shoreward in the coastal ocean outside of the surf zone. Accordingly, our

  3. Tidal Energy Research

    SciTech Connect (OSTI)

    Stelzenmuller, Nickolas [Univ of Washington; Aliseda, Alberto [Univ of Washington; Palodichuk, Michael [Univ of Washington; Polagye, Brian [Univ of Washington; Thomson, James [Univ of Washington; Chime, Arshiya [Univ of Washington; Malte, Philip [Univ of washington

    2014-03-31T23:59:59.000Z

    This technical report contains results on the following topics: 1) Testing and analysis of sub-scale hydro-kinetic turbines in a flume, including the design and fabrication of the instrumented turbines. 2) Field measurements and analysis of the tidal energy resource and at a site in northern Puget Sound, that is being examined for turbine installation. 3) Conceptual design and performance analysis of hydro-kinetic turbines operating at high blockage ratio, for use for power generation and flow control in open channel flows.

  4. Waves

    E-Print Network [OSTI]

    LaCure, Mari Mae

    2010-04-29T23:59:59.000Z

    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...

  5. A stochastic model to mimic periodic surface currents in embayments

    E-Print Network [OSTI]

    Paternostro, Christopher Lee

    2001-01-01T23:59:59.000Z

    instruments are needing to accurately determine how the tide moves throughout the bay. In addition wind can pile up water in areas adding to the tidal height. Tidal currents are even more difficult to measure. Since wind along coasts is usually persistent... dynamics, some locations have very strong tidal currents (narrow straits or resonant bays). Elsewhere within an embayment, the tidal component may be a fraction of the total current, in any case, a wind-only current model will eventually diverge from...

  6. Modulation of Wave Forces on Kelp Canopies by Alongshore Currents Author(s): Brian Gaylord, Mark W. Denny, Mimi A. R. Koehl

    E-Print Network [OSTI]

    Denny, Mark

    Modulation of Wave Forces on Kelp Canopies by Alongshore Currents Author(s): Brian Gaylord, Mark W-871 ? 2003, by the American Society of Limnology and Oceanography,Inc. Modulation of wave forces on kelp fromtheinteractionof theseorganismswiththepassingfluid. Kelp forests provide essential habitat and food for hun- dreds

  7. Vortex-Induced Vibration of a slender horizontal cylinder in currents and waves

    E-Print Network [OSTI]

    Chitwood, James Scott

    2012-06-07T23:59:59.000Z

    Vortex-Induced Vibration (VIV) is a concern when dealing with slender, flexible structural members of deepwater platforms. While much is known about the characteristics of VIV in uniform and sheared current flows, very little is known about...

  8. Seasonal variations of semidiurnal tidal perturbations in mesopause region temperature and zonal and meridional winds above

    E-Print Network [OSTI]

    .1029/2007JD009687. 1. Introduction [2] Solar thermal tides are global-scale waves that dom- inate to conserve wave energy. When propagating into the MLT region, the horizontal wind tidal amplitude can reach with fluorescence lidar's advantages of high temporal and spatial resolution and the capability of full diurnal

  9. Gravitational self-force corrections to two-body tidal interactions and the effective one-body formalism

    E-Print Network [OSTI]

    Donato Bini; Thibault Damour

    2014-09-24T23:59:59.000Z

    Tidal interactions have a significant influence on the late dynamics of compact binary systems, which constitute the prime targets of the upcoming network of gravitational-wave detectors. We refine the theoretical description of tidal interactions (hitherto known only to the second post-Newtonian level) by extending our recently developed analytic self-force formalism, for extreme mass-ratio binary systems, to the computation of several tidal invariants. Specifically, we compute, to linear order in the mass ratio and to the 7.5$^{\\rm th}$ post-Newtonian order, the following tidal invariants: the square and the cube of the gravitoelectric quadrupolar tidal tensor, the square of the gravitomagnetic quadrupolar tidal tensor, and the square of the gravitoelectric octupolar tidal tensor. Our high-accuracy analytic results are compared to recent numerical self-force tidal data by Dolan et al. \\cite{Dolan:2014pja}, and, notably, provide an analytic understanding of the light ring asymptotic behavior found by them. We transcribe our kinematical tidal-invariant results in the more dynamically significant effective one-body description of the tidal interaction energy. By combining, in a synergetic manner, analytical and numerical results, we provide simple, accurate analytic representations of the global, strong-field behavior of the gravitoelectric quadrupolar tidal factor. A striking finding is that the linear-in-mass-ratio piece in the latter tidal factor changes sign in the strong-field domain, to become negative (while its previously known second post-Newtonian approximant was always positive). We, however, argue that this will be more than compensated by a probable fast growth, in the strong-field domain, of the nonlinear-in-mass-ratio contributions in the tidal factor.

  10. GLOBAL CHANGE AND TIDAL FRESHWATER WETLANDS

    E-Print Network [OSTI]

    Neubauer, Scott C.

    Chapter 23 GLOBAL CHANGE AND TIDAL FRESHWATER WETLANDS: SCENARIOS AND IMPACTS Scott C. Neubauer Tidal Freshwater Wetlands, edited by Aat Barendregt, Dennis Whigham & Andrew Baldwin 2009, viii + 320pp Publishers GmbH This chapter was originally published in the book ,,Tidal Freshwater Wetlands". The copy

  11. Experimental Wave Tank Test for Reference Model 3 Floating-Point Absorber Wave Energy Converter Project

    SciTech Connect (OSTI)

    Yu, Y. H.; Lawson, M.; Li, Y.; Previsic, M.; Epler, J.; Lou, J.

    2015-01-01T23:59:59.000Z

    The U.S. Department of Energy established a reference model project to benchmark a set of marine and hydrokinetic technologies including current (tidal, open-ocean, and river) turbines and wave energy converters. The objectives of the project were to first evaluate the status of these technologies and their readiness for commercial applications. Second, to evaluate the potential cost of energy and identify cost-reduction pathways and areas where additional research could be best applied to accelerate technology development to market readiness.

  12. Tidal Residual Eddies and their Effect on Water Exchange in Puget Sound

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Wang, Taiping

    2013-08-30T23:59:59.000Z

    Tidal residual eddies are one of the important hydrodynamic features in tidally dominant estuaries and coastal bays, and they could have significant effects on water exchange in a tidal system. This paper presents a modeling study of tides and tidal residual eddies in Puget Sound, a tidally dominant fjord-like estuary in the Pacific Northwest coast, using a three-dimensional finite-volume coastal ocean model. Mechanisms of vorticity generation and asymmetric distribution patterns around an island/headland were analyzed using the dynamic vorticity transfer approach and numerical experiments. Model results of Puget Sound show that a number of large twin tidal residual eddies exist in the Admiralty Inlet because of the presence of major headlands in the inlet. Simulated residual vorticities near the major headlands indicate that the clockwise tidal residual eddy (negative vorticity) is generally stronger than the anticlockwise eddy (positive vorticity) because of the effect of Coriolis force. The effect of tidal residual eddies on water exchange in Puget Sound and its sub-basins were evaluated by simulations of dye transport. It was found that the strong transverse variability of residual currents in the Admiralty Inlet results in a dominant seaward transport along the eastern shore and a dominant landward transport along the western shore of the Inlet. A similar transport pattern in Hood Canal is caused by the presence of tidal residual eddies near the entrance of the canal. Model results show that tidal residual currents in Whidbey Basin are small in comparison to other sub-basins. A large clockwise residual circulation is formed around Vashon Island near entrance of South Sound, which can potentially constrain the water exchange between the Central Basin and South Sound.

  13. Planetary waves in the upper stratosphere and lower mesosphere during 2009 Arctic major stratospheric warming

    E-Print Network [OSTI]

    Kishore, P.; Velicogna, I.; Venkat Ratnam, M.; Jiang, J. H; Madhavi, G. N

    2012-01-01T23:59:59.000Z

    J. M. : The quasi-two-day wave studied using the Northernview of nonlinear water waves: the Hilbert spectrum, Annu.Pancheva, D. V. : Quasi-2-day wave and tidal variability

  14. Interaction of waves and currents with kelp forests (Macrocystis pyrifera): Insights from a dynamically scaled laboratory model

    E-Print Network [OSTI]

    Denny, Mark

    a dynamically matched 1/25-scale physical model in a laboratory flume. In experiments with kelp mimics, waves a dynamically scaled laboratory model Johanna H. Rosman,a,* Mark W. Denny,b Robert B. Zeller,c Stephen G between model kelp and water under waves increased wake generation of turbulence, resulting in turbulent

  15. Tidally-induced thermonuclear Supernovae

    E-Print Network [OSTI]

    Stephan Rosswog; Enrico Ramirez-ruiz; W. Raphael Hix

    We discuss the results of 3D simulations of tidal disruptions of white dwarfs by moderate-mass black holes as they may exist in the cores of globular clusters or dwarf galaxies. Our simulations follow self-consistently the hydrodynamic and nuclear evolution from the initial parabolic orbit over the disruption to the build-up of an accretion disk around the black hole. For strong enough encounters (pericentre distances smaller than about 1/3 of the tidal radius) the tidal compression is reversed by a shock and finally results in a thermonuclear explosion. These explosions are not restricted to progenitor masses close to the Chandrasekhar limit, we find exploding examples throughout the whole white dwarf mass range. There is, however, a restriction on the masses of the involved black holes: black holes more massive than 2 × 10 5 M? swallow a typical 0.6 M ? white dwarf before their tidal forces can overwhelm the star’s selfgravity. Therefore, this mechanism is characteristic for black holes of moderate masses. The material that remains bound to the black hole settles into an accretion disk and produces an X-ray flare close to the Eddington limit of LEdd ? 10 41 erg/s (Mbh/1000M?), typically lasting for a few months. The combination of a peculiar thermonuclear supernova together with an X-ray flare thus whistle-blows the existence of such moderate-mass black holes. The next generation of wide field space-based instruments should be able to detect such events. 1.

  16. Tidally-induced thermonuclear Supernovae

    E-Print Network [OSTI]

    S. Rosswog; E. Ramirez-Ruiz; W. R. Hix

    2008-11-13T23:59:59.000Z

    We discuss the results of 3D simulations of tidal disruptions of white dwarfs by moderate-mass black holes as they may exist in the cores of globular clusters or dwarf galaxies. Our simulations follow self-consistently the hydrodynamic and nuclear evolution from the initial parabolic orbit over the disruption to the build-up of an accretion disk around the black hole. For strong enough encounters (pericentre distances smaller than about 1/3 of the tidal radius) the tidal compression is reversed by a shock and finally results in a thermonuclear explosion. These explosions are not restricted to progenitor masses close to the Chandrasekhar limit, we find exploding examples throughout the whole white dwarf mass range. There is, however, a restriction on the masses of the involved black holes: black holes more massive than $2\\times 10^5$ M$_\\odot$ swallow a typical 0.6 M$_\\odot$ dwarf before their tidal forces can overwhelm the star's self-gravity. Therefore, this mechanism is characteristic for black holes of moderate masses. The material that remains bound to the black hole settles into an accretion disk and produces an X-ray flare close to the Eddington limit of $L_{\\rm Edd} \\simeq 10^{41} {\\rm erg/s} M_{\\rm bh}/1000 M$_\\odot$), typically lasting for a few months. The combination of a peculiar thermonuclear supernova together with an X-ray flare thus whistle-blows the existence of such moderate-mass black holes. The next generation of wide field space-based instruments should be able to detect such events.

  17. Modeling the Energy Output from an In-Stream Tidal Turbine Farm

    E-Print Network [OSTI]

    Ye Li; Barbara J. Lence; Sander M. Calisal

    Abstract—This paper is based on a recent paper presented in the 2007 IEEE SMC conference by the same authors [1], discussing an approach to predicting energy output from an instream tidal turbine farm. An in-stream tidal turbine is a device for harnessing energy from tidal currents in channels, and functions in a manner similar to a wind turbine. A group of such turbines distributed in a site is called an in-stream tidal turbine farm which is similar to a wind farm. Approaches to estimating energy output from wind farms cannot be fully transferred to study tidal farms, however, because of the complexities involved in modeling turbines underwater. In this paper, we intend to develop an approach for predicting energy output of an in-stream tidal turbine farm. The mathematical formulation and basic procedure for predicting power output of a stand-alone turbine 1 is presented, which includes several highly nonlinear terms. In order to facilitate the computation and utilize the formulation for predicting power output from a turbine farm, a simplified relationship between turbine distribution and turbine farm energy output is derived. A case study is then conducted by applying the numerical procedure to predict the energy output of the farms. Various scenarios are implemented according to the environmental conditions in Seymour Narrows, British Columbia, Canada. Additionally, energy cost results are presented as an extension. Index Terms—renewable energy, in-stream turbine, tidal current, tidal power, vertical axis turbine, farm system modeling, in-stream tidal turbine farm 1 A stand-alone turbine refers to a turbine around which there is no other turbine that might potentially affect the performance of this turbine.

  18. TIDAL FRICTION AND TIDAL LAGGING. APPLICABILITY LIMITATIONS OF A POPULAR FORMULA FOR THE TIDAL TORQUE

    SciTech Connect (OSTI)

    Efroimsky, Michael; Makarov, Valeri V., E-mail: michael.efroimsky@usno.navy.mil, E-mail: vvm@usno.navy.mil [US Naval Observatory, Washington, DC 20392 (United States)

    2013-02-10T23:59:59.000Z

    Tidal torques play a key role in rotational dynamics of celestial bodies. They govern these bodies' tidal despinning and also participate in the subtle process of entrapment of these bodies into spin-orbit resonances. This makes tidal torques directly relevant to the studies of habitability of planets and their moons. Our work begins with an explanation of how friction and lagging should be built into the theory of bodily tides. Although much of this material can be found in various publications, a short but self-consistent summary on the topic has been lacking in the hitherto literature, and we are filling the gap. After these preparations, we address a popular concise formula for the tidal torque, which is often used in the literature, for planets or stars. We explain why the derivation of this expression, offered in the paper by Goldreich and in the books by Kaula (Equation (4.5.29)) and Murray and Dermott (Equation (4.159)), implicitly sets the time lag to be frequency independent. Accordingly, the ensuing expression for the torque can be applied only to bodies having a very special (and very hypothetical) rheology which makes the time lag frequency independent, i.e., the same for all Fourier modes in the spectrum of tide. This expression for the torque should not be used for bodies of other rheologies. Specifically, the expression cannot be combined with an extra assertion of the geometric lag being constant, because at finite eccentricities the said assumption is incompatible with the constant-time-lag condition.

  19. Characterization of sediment movement in tidal creeks adjacent to the gulf intracoastal waterway at Aransas National Wildlife Refuge, Austwell, TX: study of natural factors and effects of barge-induced drawdown currents

    E-Print Network [OSTI]

    Allison, John Bryan

    2005-08-29T23:59:59.000Z

    , these are the rarest cranes in the world. The wetlands in which they winter are a part of the San Antonio Bay system, a bay that receives constant fresh water flow from the Guadalupe River. Currently there is a plan for using water diverted from the Guadalupe River...

  20. Tidal Electric | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia:FAQ < RAPID Jump to:Seadov Pty LtdSteen,Ltd Jump JumpAl., 1978) |Thrall,Tibagi Energetica Jump to:Tidal

  1. Tidal Heating of Extra-Solar Planets

    E-Print Network [OSTI]

    Brian Jackson; Richard Greenberg; Rory Barnes

    2008-02-29T23:59:59.000Z

    Extra-solar planets close to their host stars have likely undergone significant tidal evolution since the time of their formation. Tides probably dominated their orbital evolution once the dust and gas had cleared away, and as the orbits evolved there was substantial tidal heating within the planets. The tidal heating history of each planet may have contributed significantly to the thermal budget that governed the planet's physical properties, including its radius, which in many cases may be measured by observing transit events. Typically, tidal heating increases as a planet moves inward toward its star and then decreases as its orbit circularizes. Here we compute the plausible heating histories for several planets with measured radii, using the same tidal parameters for the star and planet that had been shown to reconcile the eccentricity distribution of close-in planets with other extra-solar planets. Several planets are discussed, including for example HD 209458 b, which may have undergone substantial tidal heating during the past billion years, perhaps enough to explain its large measured radius. Our models also show that GJ 876 d may have experienced tremendous heating and is probably not a solid, rocky planet. Theoretical models should include the role of tidal heating, which is large, but time-varying.

  2. A Conceptual Restoration Plan and Tidal Hydrology Assessment for Reconnecting Spring Branch Creek to Suisun Marsh, Solano County, California

    E-Print Network [OSTI]

    Olson, Jessica J.

    2012-01-01T23:59:59.000Z

    tidal wetland below MHLW Table 4.19. Performance IndicatorsPerformance Indicator All Tidal wetlands Tidal wetlands All

  3. Half Moon Cove Tidal Project. Feasibility report

    SciTech Connect (OSTI)

    Not Available

    1980-11-01T23:59:59.000Z

    The proposed Half Moon Cove Tidal Power Project would be located in a small cove in the northern part of Cobscook Bay in the vicinity of Eastport, Maine. The project would be the first tidal electric power generating plant in the United States of America. The basin impounded by the barrier when full will approximate 1.2 square miles. The average tidal range at Eastport is 18.2 feet. The maximum spring tidal range will be 26.2 feet and the neap tidal range 12.8 feet. The project will be of the single pool-type single effect in which generation takes place on the ebb tide only. Utilizing an average mean tidal range of 18.2 feet the mode of operation enables generation for approximately ten and one-half (10-1/2) hours per day or slightly in excess of five (5) hours per tide. The installed capacity will be 12 MW utilizing 2 to 6 MW units. An axial flow, or Bulb type of turbine was selected for this study.

  4. Viscoelastic Models of Tidally Heated Exomoons

    E-Print Network [OSTI]

    Dobos, Vera

    2015-01-01T23:59:59.000Z

    Tidal heating of exomoons may play a key role in their habitability, since the elevated temperature can melt the ice on the body even without significant solar radiation. The possibility of life is intensely studied on Solar System moons such as Europa or Enceladus, where the surface ice layer covers tidally heated water ocean. Tidal forces may be even stronger in extrasolar systems, depending on the properties of the moon and its orbit. For studying the tidally heated surface temperature of exomoons, we used a viscoelastic model for the first time. This model is more realistic than the widely used, so-called fixed Q models, because it takes into account the temperature dependency of the tidal heat flux, and the melting of the inner material. With the use of this model we introduced the circumplanetary Tidal Temperate Zone (TTZ), that strongly depends on the orbital period of the moon, and less on its radius. We compared the results with the fixed Q model and investigated the statistical volume of the TTZ usi...

  5. Fitting orbits to tidal streams

    E-Print Network [OSTI]

    James Binney

    2008-02-11T23:59:59.000Z

    Recent years have seen the discovery of many tidal streams through the Galaxy. Relatively straightforward observations of a stream allow one to deduce three phase-space coordinates of an orbit. An algorithm is presented that reconstructs the missing phase-space coordinates from these data. The reconstruction starts from assumed values of the Galactic potential and a distance to one point on the orbit, but with noise-free data the condition that energy be conserved on the orbit enables one to reject incorrect assumptions. The performance of the algorithm is investigated when errors are added to the input data that are comparable to those in published data for the streams of Pal 5. It is found that the algorithm returns distances and proper motions that are accurate to of order one percent, and enables one to reject quite reasonable but incorrect trial potentials. In practical applications it will be important to minimize errors in the input data, and there is considerable scope for doing this.

  6. On the statistical stability of the M2 barotropic and baroclinic tidal characteristics from along-track TOPEX//Poseidon

    E-Print Network [OSTI]

    with internal tidal wave activity and for those who assimilate altimetric data in their models by giving-track TOPEX//Poseidon satellite altimetry analysis Loren Carre`re, Christian Le Provost, and Florent Lyard. [1] An along-track analysis of 7 years of TOPEX/Poseidon (T/P) data has been performed on the global

  7. Refinement and validation of a multi-level assessment method for Mid-Atlantic tidal wetlands

    E-Print Network [OSTI]

    Refinement and validation of a multi-level assessment method for Mid-Atlantic tidal wetlands (EPA of wetland resources across the Mid-Atlantic physiographic region, efforts are currently underway in a number of states, most notably Delaware, Maryland, Pennsylvania and Virginia, to develop and implement wetland

  8. mm-Wave Phase Shifters and Switches

    E-Print Network [OSTI]

    Adabi Firouzjaei, Ehsan

    2010-01-01T23:59:59.000Z

    4.1.1 Slow wave transmissioncombiners . . . . . . . . . . . 5.3 mm-Wave implementationfailed to predict current mm-wave design trend [1] . . . . .

  9. THE INFLUENCE OF ORBITAL ECCENTRICITY ON TIDAL RADII OF STAR CLUSTERS

    SciTech Connect (OSTI)

    Webb, Jeremy J.; Harris, William E.; Sills, Alison [Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1 (Canada)] [Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1 (Canada); Hurley, Jarrod R., E-mail: webbjj@mcmaster.ca [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218, VIC 3122 (Australia)

    2013-02-20T23:59:59.000Z

    We have performed N-body simulations of star clusters orbiting in a spherically symmetric smooth galactic potential. The model clusters cover a range of initial half-mass radii and orbital eccentricities in order to test the historical assumption that the tidal radius of a cluster is imposed at perigalacticon. The traditional assumption for globular clusters is that since the internal relaxation time is larger than its orbital period, the cluster is tidally stripped at perigalacticon. Instead, our simulations show that a cluster with an eccentric orbit does not need to fully relax in order to expand. After a perigalactic pass, a cluster recaptures previously unbound stars, and the tidal shock at perigalacticon has the effect of energizing inner region stars to larger orbits. Therefore, instead of the limiting radius being imposed at perigalacticon, it more nearly traces the instantaneous tidal radius of the cluster at any point in the orbit. We present a numerical correction factor to theoretical tidal radii calculated at perigalacticon which takes into consideration both the orbital eccentricity and current orbital phase of the cluster.

  10. Turbulence and internal waves in tidal flow over topography

    E-Print Network [OSTI]

    Gayen, Bishakhdatta

    2012-01-01T23:59:59.000Z

    water, so as to avoid an unnecessary increase in computational grid points. Simulations at subcritical

  11. European Wave and Tidal Energy Conference | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:Year in Review:Department of Energy Environmental RestorationErik HyrkasMarketsSeeking

  12. Hydropower, Wave and Tidal Technologies Available for Licensing - Energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest Region service area.Portal SolarAboutSeparationsRelevantHydropower

  13. 12th Annual Wave & Tidal 2015 | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:Year in Review: Top Five EERE Blog Posts of 2014 Year in Review:Summer-0 Resources Daysof12th

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

    Energy Savers [EERE]

    Renewable Power Company (ORPC) is conducting a two-year study on the effects of tidal turbines on endangered beluga whales in Cook Inlet, Alaska-home to some of the greatest tidal...

  15. TIDAL FRESHWATER WETLANDS OF THE MID-ATLANTIC AND

    E-Print Network [OSTI]

    Newman, Michael C.

    Chapter 14 TIDAL FRESHWATER WETLANDS OF THE MID-ATLANTIC AND SOUTHEASTERN UNITED STATES James E Publishers, Weikersheim, 2009 Tidal Freshwater Wetlands, edited by Aat Barendregt in the book ,,Tidal Freshwater Wetlands". The copy attached is provided by Margraf Publishers Gmb

  16. On tidal capture of primordial black holes by neutron stars

    E-Print Network [OSTI]

    Guillaume Defillon; Etienne Granet; Petr Tinyakov; Michel H. G. Tytgat

    2014-09-01T23:59:59.000Z

    The fraction of primordial black holes (PBHs) of masses $10^{17} - 10^{26}$ g in the total amount of dark matter may be constrained by considering their capture by neutron stars (NSs), which leads to the rapid destruction of the latter. The constraints depend crucially on the capture rate which, in turn, is determined by the energy loss by a PBH passing through a NS. Two alternative approaches to estimate the energy loss have been used in the literature: the one based on the dynamical friction mechanism, and another on tidal deformations of the NS by the PBH. The second mechanism was claimed to be more efficient by several orders of magnitude due to the excitation of particular oscillation modes reminiscent of the surface waves. We address this disagreement by considering a simple analytically solvable model that consists of a flat incompressible fluid in an external gravitational field. In this model, we calculate the energy loss by a PBH traversing the fluid surface. We find that the excitation of modes with the propagation velocity smaller than that of PBH is suppressed, which implies that in a realistic situation of a supersonic PBH the large contributions from the surface waves are absent and the above two approaches lead to consistent expressions for the energy loss.

  17. Tidal interactions in multi-planet systems

    E-Print Network [OSTI]

    Papaloizou, J C B

    2011-01-01T23:59:59.000Z

    We study systems of close orbiting planets evolving under the influence of tidal circularization. It is supposed that a commensurability forms through the action of disk induced migration and orbital circularization. After the system enters an inner cavity or the disk disperses the evolution continues under the influence of tides due to the central star which induce orbital circularization. We derive approximate analytic models that describe the evolution away from a general first order resonance that results from tidal circularization in a two planet system and which can be shown to be a direct consequence of the conservation of energy and angular momentum. We consider the situation when the system is initially very close to resonance and also when the system is between resonances. We also perform numerical simulations which confirm these models and then apply them to two and four planet systems chosen to have parameters related to the GJ581 and HD10180 systems. We also estimate the tidal dissipation rates t...

  18. Generation of internal waves in the deep ocean J. Nycander

    E-Print Network [OSTI]

    Nycander, Jonas

    Generation of internal waves in the deep ocean by tides J. Nycander Department of Meteorology; published 29 October 2005. [1] A direct computation of the tidal generation of internal waves over and to nonlinear effects caused by supercritical bottom slope. Citation: Nycander, J. (2005), Generation

  19. All Eyes on Eastport: Tidal Energy Project Brings Change, Opportunity...

    Office of Environmental Management (EM)

    Ocean Renewable Power Company will unveil its first commercial-scale tidal turbine before it is deployed underwater to generate power. The pilot project -- supported by...

  20. Temperature and Tidal Dynamics in a Branching Estuarine System

    E-Print Network [OSTI]

    Wagner, Richard Wayne

    2012-01-01T23:59:59.000Z

    Importance of the Interconnectivity of Branching ChannelsImportance of the Interconnectivity of Branching Channels Inquestions about tidal interconnectivity in the Sacramento-

  1. Assessment of Energy Production Potential from Tidal Streams...

    Office of Environmental Management (EM)

    technology. 1023527.pdf More Documents & Publications EA-1949: FERC Draft Environmental Assessment EA-1949: FERC Final Environmental Assessment Tidal Energy Resource Assessment...

  2. EA-1916: Ocean Renewable Power Company Maine, LLC Cobscook Bay Tidal Energy Pilot Project, Cobscook in Washington County, Maine

    Broader source: Energy.gov [DOE]

    Draft Environmental AssessmentThis EA evaluates the environmental impacts of a project that would use the tidal currents of Cobscook Bay to generate electricity via cross-flow Kinetic System turbine generator units (TGU) mounted on the seafloor. The TGUs would capture energy from the flow in both ebb and flood directions.

  3. Active Flow Control on Bidirectional Rotors for Tidal MHK Applications

    SciTech Connect (OSTI)

    Shiu, Henry [Research Engineer; van Dam, Cornelis P. [Professor

    2013-08-22T23:59:59.000Z

    A marine and hydrokinetic (MHK) tidal turbine extracts energy from tidal currents, providing clean, sustainable electricity generation. In general, all MHK conversion technologies are confronted with significant operational hurdles, resulting in both increased capital and operations and maintenance (O&M) costs. To counter these high costs while maintaining reliability, MHK turbine designs can be simplified. Prior study found that a tidal turbine could be cost-effectively simplified by removing blade pitch and rotor/nacelle yaw. Its rotor would run in one direction during ebb and then reverse direction when the current switched to flood. We dubbed such a turbine a bidirectional rotor tidal turbine (BRTT). The bidirectional hydrofoils of a BRTT are less efficient than conventional hydrofoils and capture less energy, but the elimination of the pitch and yaw systems were estimated to reduce levelized cost of energy by 7.8%-9.6%. In this study, we investigated two mechanisms for recapturing some of the performance shortfall of the BRTT. First, we developed a novel set of hydrofoils, designated the yy series, for BRTT application. Second, we investigated the use of active flow control via microtabs. Microtabs are small deployable/retractable tabs, typically located near the leading or trailing edge of an air/hydrofoil with height on the order of the boundary layer thickness (1% - 2% of chord). They deploy approximately perpendicularly to the foil surface and, like gurney flaps and plain flaps, globally affect the aerodynamics of the airfoil. By strategically placing microtabs and selectively deploying them based on the direction of the inflow, performance of a BRTT rotor can be improved while retaining bidirectional operation. The yy foils were computationally designed and analyzed. They exhibited better performance than the baseline bidirectional foil, the ellipse. For example, the yyb07cn-180 had 14.7% higher (l/d)max than an ellipse of equal thickness. The yyb07cn family also had higher c{sub p,min} than equivalently thick ellipses, indicating less susceptibility to cavitation. Microtabs applied on yy foils demonstrated improved energy capture. A series of variable speed and constant speed rotors were developed with the yyb07cn family of hydrofoils. The constant speed yyb07cn rotor (yy-B02-Rcs,opt) captured 0.45% more energy than the equivalent rotor with ellipses (e-B02-Rcs,opt). With microtabs deployed (yy?t-B02-Rcs,opt), the energy capture increase over the rotor with ellipses was 1.05%. Note, however, that microtabs must be applied judiciously to bidirectional foils. On the 18% thick ellipse, performance decreased with the addition of microtabs. Details of hydrofoil performance, microtab sizing and positioning, rotor configurations, and revenue impacts are presented herein.

  4. Tidal inlet processes and deposits along a low energy coastline: easter Barataria Bight, Louisiana

    SciTech Connect (OSTI)

    Moslow, T.F.; Levin, D.R.

    1985-01-01T23:59:59.000Z

    Historical, seismic and vibracore data were used to determine the geologic framework of sand deposits along the predominantly muddy coastline of eastern Barataria Bight, Louisiana. Three inlet types with distinct sand body geometries and morphologies were identified and are found 1) at flanking barrier island systems spread laterally across the front of interdistributary bays; 2) in old distributary channels; 3) at overwash breaches; or 4) combination of these. Barataria Bight, a sheltered barrier island shoreline embayment with limited sand supply, minimal tidal range (36 cm) and low wave energies (30 cm) can be used to show examples of each inlet type. Barataria Pass and Quatre Bayou Pass are inlets located in old distributary channels. However, Barataria Pass has also been affected by construction between barrier islands. Pass Ronquille is located where the coastline has transgressed a low area in the delta plain. This breach is situated in a hydraulically efficient avenue between the Gulf and Bay Long behind it. Pass Abel is a combination of a low-profile barrier breach and the reoccupation of an old distributary channel. Shelf and shoreline sands are reworked from abandoned deltaic distributaries and headlands. Inner shelf sands are concentrated in thick (10 m) shore-normal relict distributary channels with fine grained cross-bedded and ripple laminated sand overlain by burrowed shelf muds. Shoreface sand deposits occur as 2-3 m thick, fine-grained, coarsening upward and burrowed ebb-tidal delta sequences and shore-parallel relict tidal inlet channels filled through lateral accretion.

  5. Study of the Acoustic Effects of Hydrokinetic Tidal Turbines in Admiralty Inlet, Puget Sound

    SciTech Connect (OSTI)

    Brian Polagye; Jim Thomson; Chris Bassett; Jason Wood; Dom Tollit; Robert Cavagnaro; Andrea Copping

    2012-03-30T23:59:59.000Z

    Hydrokinetic turbines will be a source of noise in the marine environment - both during operation and during installation/removal. High intensity sound can cause injury or behavioral changes in marine mammals and may also affect fish and invertebrates. These noise effects are, however, highly dependent on the individual marine animals; the intensity, frequency, and duration of the sound; and context in which the sound is received. In other words, production of sound is a necessary, but not sufficient, condition for an environmental impact. At a workshop on the environmental effects of tidal energy development, experts identified sound produced by turbines as an area of potentially significant impact, but also high uncertainty. The overall objectives of this project are to improve our understanding of the potential acoustic effects of tidal turbines by: (1) Characterizing sources of existing underwater noise; (2) Assessing the effectiveness of monitoring technologies to characterize underwater noise and marine mammal responsiveness to noise; (3) Evaluating the sound profile of an operating tidal turbine; and (4) Studying the effect of turbine sound on surrogate species in a laboratory environment. This study focuses on a specific case study for tidal energy development in Admiralty Inlet, Puget Sound, Washington (USA), but the methodologies and results are applicable to other turbine technologies and geographic locations. The project succeeded in achieving the above objectives and, in doing so, substantially contributed to the body of knowledge around the acoustic effects of tidal energy development in several ways: (1) Through collection of data from Admiralty Inlet, established the sources of sound generated by strong currents (mobilizations of sediment and gravel) and determined that low-frequency sound recorded during periods of strong currents is non-propagating pseudo-sound. This helped to advance the debate within the marine and hydrokinetics acoustic community as to whether strong currents produce propagating sound. (2) Analyzed data collected from a tidal turbine operating at the European Marine Energy Center to develop a profile of turbine sound and developed a framework to evaluate the acoustic effects of deploying similar devices in other locations. This framework has been applied to Public Utility District No. 1 of Snohomish Country's demonstration project in Admiralty Inlet to inform postinstallation acoustic and marine mammal monitoring plans. (3) Demonstrated passive acoustic techniques to characterize the ambient noise environment at tidal energy sites (fixed, long-term observations recommended) and characterize the sound from anthropogenic sources (drifting, short-term observations recommended). (4) Demonstrated the utility and limitations of instrumentation, including bottom mounted instrumentation packages, infrared cameras, and vessel monitoring systems. In doing so, also demonstrated how this type of comprehensive information is needed to interpret observations from each instrument (e.g., hydrophone data can be combined with vessel tracking data to evaluate the contribution of vessel sound to ambient noise). (5) Conducted a study that suggests harbor porpoise in Admiralty Inlet may be habituated to high levels of ambient noise due to omnipresent vessel traffic. The inability to detect behavioral changes associated with a high intensity source of opportunity (passenger ferry) has informed the approach for post-installation marine mammal monitoring. (6) Conducted laboratory exposure experiments of juvenile Chinook salmon and showed that exposure to a worse than worst case acoustic dose of turbine sound does not result in changes to hearing thresholds or biologically significant tissue damage. Collectively, this means that Chinook salmon may be at a relatively low risk of injury from sound produced by tidal turbines located in or near their migration path. In achieving these accomplishments, the project has significantly advanced the District's goals of developing a demonstration-scale tidal energy proj

  6. THE EFFECT OF MASS LOSS ON THE TIDAL EVOLUTION OF EXTRASOLAR PLANET

    E-Print Network [OSTI]

    Guo, Jianheng

    By combining mass loss and tidal evolution of close-in planets, we present a qualitative study on their tidal migrations. We incorporate mass loss in tidal evolution for planets with different masses and find that mass ...

  7. Tocardo Tidal Energy Ltd | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revisionEnvReviewNonInvasiveExplorationUT-gTaguspark JumpDetective: Terminology andInformationTocardo Tidal

  8. Tidal Energy Resource Assessment | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-Up from theDepartment of EnergyThe Sun and Its EnergyMetalofAgreement forTidal Energy

  9. Tidal Energy Test Platform | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia:FAQ < RAPID Jump to:Seadov Pty LtdSteen,Ltd Jump JumpAl., 1978) |Thrall,Tibagi Energetica Jump to:TidalTest

  10. Acoustic Monitoring of Beluga Whale Interactions with Cook Inlet Tidal Energy Project

    SciTech Connect (OSTI)

    Worthington, Monty [Project Director - AK] [Project Director - AK

    2014-02-05T23:59:59.000Z

    Cook Inlet, Alaska is home to some of the greatest tidal energy resources in the U.S., as well as an endangered population of beluga whales (Delphinapterus leucas). Successfully permitting and operating a tidal power project in Cook Inlet requires a biological assessment of the potential and realized effects of the physical presence and sound footprint of tidal turbines on the distribution, relative abundance, and behavior of Cook Inlet beluga whales. ORPC Alaska, working with the Project Team—LGL Alaska Research Associates, University of Alaska Anchorage, TerraSond, and Greeneridge Science—undertook the following U.S. Department of Energy (DOE) study to characterize beluga whales in Cook Inlet – Acoustic Monitoring of Beluga Whale Interactions with the Cook Inlet Tidal Energy Project (Project). ORPC Alaska, LLC, is a wholly-owned subsidiary of Ocean Renewable Power Company, LLC, (collectively, ORPC). ORPC is a global leader in the development of hydrokinetic power systems and eco-conscious projects that harness the power of ocean and river currents to create clean, predictable renewable energy. ORPC is developing a tidal energy demonstration project in Cook Inlet at East Foreland where ORPC has a Federal Energy Regulatory Commission (FERC) preliminary permit (P-13821). The Project collected baseline data to characterize pre-deployment patterns of marine mammal distribution, relative abundance, and behavior in ORPC’s proposed deployment area at East Foreland. ORPC also completed work near Fire Island where ORPC held a FERC preliminary permit (P-12679) until March 6, 2013. Passive hydroacoustic devices (previously utilized with bowhead whales in the Beaufort Sea) were adapted for study of beluga whales to determine the relative abundance of beluga whale vocalizations within the proposed deployment areas. Hydroacoustic data collected during the Project were used to characterize the ambient acoustic environment of the project site pre-deployment to inform the FERC pilot project process. The Project compared results obtained from this method to results obtained from other passive hydrophone technologies and to visual observation techniques performed simultaneously. This Final Report makes recommendations on the best practice for future data collection, for ORPC’s work in Cook Inlet specifically, and for tidal power projects in general. This Project developed a marine mammal study design and compared technologies for hydroacoustic and visual data collection with potential for broad application to future tidal and hydrokinetic projects in other geographic areas. The data collected for this Project will support the environmental assessment of future Cook Inlet tidal energy projects, including ORPC’s East Foreland Tidal Energy Project and any tidal energy developments at Fire Island. The Project’s rigorous assessment of technology and methodologies will be invaluable to the hydrokinetic industry for developing projects in an environmentally sound and sustainable way for areas with high marine mammal activity or endangered populations. By combining several different sampling methods this Project will also contribute to the future preparation of a comprehensive biological assessment of ORPC’s projects in Cook Inlet.

  11. Hysteresis of ionization waves

    SciTech Connect (OSTI)

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

    2008-06-15T23:59:59.000Z

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

  12. Full wave simulations of lower hybrid wave propagation in tokamaks

    E-Print Network [OSTI]

    Wright, John C.

    Full wave simulations of lower hybrid wave propagation in tokamaks J. C. Wright , P. T. Bonoli , C hybrid (LH) waves have the attractive property of damping strongly via electron Landau resonance. Consequently these waves are well-suited to driving current in the plasma periphery where the electron

  13. SKA as a powerful hunter of jetted Tidal Disruption Events

    E-Print Network [OSTI]

    Donnarumma, I; Fender, R; Komossa, S; Paragi, Z; Van Velzen, S; Prandoni, I

    2015-01-01T23:59:59.000Z

    Observational consequences of the tidal disruption of stars by supermassive black holes (SMBHs) can enable us to discover quiescent SMBHs and constrain their mass function. Moreover, observing jetted TDEs (from previously non-active galaxies) provides us with a new means of studying the early phases of jet formation and evolution in an otherwise "pristine" environment. Although several (tens) TDEs have been discovered since 1999, only two jetted TDEs have been recently discovered in hard X-rays, and only one, Swift J1644+57, has a precise localization which further supports the TDE interpretation. These events alone are not sufficient to address those science issues, which require a substantial increase of the current sample. Despite the way they were discovered, the highest discovery potential for {\\em jetted} TDEs is not held by current and up-coming X-ray instruments, which will yield only a few to a few tens events per year. In fact, the best strategy is to use the Square Kilometer Array to detect TDEs an...

  14. Reconstructing the neutron-star equation of state with gravitational-wave detectors from a realistic population of inspiralling binary neutron stars

    E-Print Network [OSTI]

    Benjamin D. Lackey; Leslie Wade

    2014-10-31T23:59:59.000Z

    Gravitational-wave observations of inspiralling binary neutron star systems can be used to measure the neutron-star equation of state (EOS) through the tidally induced shift in the waveform phase that depends on the tidal deformability parameter $\\lambda$. Previous work has shown that $\\lambda$, a function of the neutron-star EOS and mass, is measurable by Advanced LIGO for a single event when including tidal information up to the merger frequency. In this work, we describe a method for stacking measurements of $\\lambda$ from multiple inspiral events to measure the EOS. We use Markov chain Monte Carlo simulations to estimate the parameters of a 4-parameter piecewise polytrope EOS that matches theoretical EOS models to a few percent. We find that, for "realistic" event rates ($\\sim 40$ binary neutron star inspiral events per year with signal-to-noise ratio $> 8$ in a single Advanced LIGO detector), combining a year of gravitational-wave data from a three-detector network with the constraints from causality and recent high mass neutron-star measurements, the EOS above nuclear density can be measured to better than a factor of two in pressure in most cases. We also find that in the mass range $1M_\\odot$--$2M_\\odot$, the neutron-star radius can be measured to better than $\\pm 1$ km and the tidal deformability can be measured to better than $\\pm 1 \\times 10^{36}$ g cm$^2$ s$^2$ (10%--50% depending on the EOS and mass). The overwhelming majority of this information comes from the loudest $\\sim 5$ events. Current uncertainties in the post-Newtonian waveform model, however, lead to systematic errors in the EOS measurement that are as large as the statistical errors, and more accurate waveform models are needed to minimize this error.

  15. Gravity Waves Gravity Waves

    E-Print Network [OSTI]

    Weijgaert, Rien van de

    ;14/03/2014 6 H L H L L Phase & Group Velocity #12;14/03/2014 7 Doppler Effect #12;14/03/2014 8 Shock Waves #12;14/03/2014 14 Supernova Remnant Cassiopeia A Supernova blast waves #12;14/03/2014 15 Tycho's Remnant (SN 1572AD A SNR flythrough Theory of Supernova Blast Waves Supernovae: Type Ia Subsonic deflagration wave turning

  16. Disc formation from stellar tidal disruptions

    E-Print Network [OSTI]

    Bonnerot, Clément; Lodato, Giuseppe; Price, Daniel J

    2015-01-01T23:59:59.000Z

    The potential of tidal disruption of stars to probe otherwise quiescent supermassive black holes cannot be exploited, if their dynamics is not fully understood. So far, the observational appearance of these events has been commonly derived from analytical extrapolations of the debris dynamical properties just after the stellar disruption. In this paper, we perform hydrodynamical simulations of stars in highly eccentric orbits, that follow the stellar debris after disruption and investigate their ultimate fate. We demonstrate that gas debris circularize on an orbital timescale because relativistic apsidal precession causes the stream to self-cross. The higher the eccentricity and/or the deeper the encounter, the faster is the circularization. If the internal energy deposited by shocks during stream self-interaction is readily radiated, the gas forms a narrow ring at the circularization radius. It will then proceed to accrete viscously at a super-Eddington rate, puffing up under radiation pressure. If instead c...

  17. Surface Wave Effects on High-Frequency Currents over a Shelf Edge Bank H. W. WIJESEKERA, D. W. WANG, W. J. TEAGUE, E. JAROSZ, AND W. E. ROGERS

    E-Print Network [OSTI]

    Several acoustic Doppler current profilers and vertical strings of temperature, conductivity, and pressure and thermocline, and play a vital role in climate variability, biological productivity, and marine pollution

  18. Horizontal coherence of low-frequency fixed-path sound in a continental shelf region with internal-wave activity

    E-Print Network [OSTI]

    Horizontal coherence of low-frequency fixed-path sound in a continental shelf region with internal-wave) populated with tidally generated long- and short-wavelength internal waves. Sound paths are 19 km and explain sound field spatial and temporal variability under these conditions. The intermittent internal-wave

  19. Resonant Generation of Internal Waves on a Model Continental Slope H. P. Zhang, B. King, and Harry L. Swinney

    E-Print Network [OSTI]

    Texas at Austin. University of

    Resonant Generation of Internal Waves on a Model Continental Slope H. P. Zhang, B. King, and Harry wave generation in a laboratory model of oscillating tidal flow on a continental margin. Waves are found to be generated only in a near-critical region where the slope of the bottom topography matches

  20. The Maine Coastal Current: Spring Climatological Circulation

    E-Print Network [OSTI]

    on the Coastal Current. The nested calculations also expose finer structure due to river sources, heat flux, river discharges) and remote (Gulf­scale) forcing are examined. Tidal rectification in the Eastern Gulf; otherwise unreal­ istic exchanges with the Gulf occur. An approximate division of local and remote dynamical

  1. Tidal salt marshes of the southeast Atlantic Coast: A community profile

    SciTech Connect (OSTI)

    Wiegert, R.G.; Freeman, B.J.

    1990-09-01T23:59:59.000Z

    This report is part of a series of community profiles on the ecology of wetland and marine communities. This particular profile considers tidal marshes of the southeastern Atlantic coast, from North Carolina south to northern Florida. Alone among the earth's ecosystems, coastal communities are subjected to a bidirectional flooding sometimes occurring twice each day; this flooding affects successional development, species composition, stability, and productivity. In the tidally influenced salt marsh, salinity ranges from less than 1 ppt to that of seawater. Dominant plant species include cordgrasses (Spartina alterniflora and S. cynosuroides), black needlerush (Juncus romerianus), and salt marsh bulrush (Scirpus robustus). Both terrestrail and aquatic animals occur in salt marshes and include herons, egrets ospreys (Pandion haliaetus), bald eagles (Haliaeetus leucocephalus), alligators (Alligator Mississippiensis), manatees (Trichecus manatus), oysters, mussels, and fiddler crabs. Currently, the only significant direct commercial use of the tidal salt marshes is by crabbers seeking the blue crab Callinectes sapidus, but the marshes are quite important recreationally, aesthetically, and educationally. 151 refs., 45 figs., 6 tabs.

  2. Environmental Effects of Sediment Transport Alteration and Impacts on Protected Species: Edgartown Tidal Energy Project

    SciTech Connect (OSTI)

    Barrett, Stephen B.; Schlezinger, David, Ph.D; Cowles, Geoff, Ph.D; Hughes, Patricia; Samimy; Roland, I.; and Terray, E, Ph.D.

    2012-12-29T23:59:59.000Z

    The Islands of Martha�¢����s Vineyard and Nantucket are separated from the Massachusetts mainland by Vineyard and Nantucket Sounds; water between the two islands flows through Muskeget Channel. The towns of Edgartown (on Martha�¢����s Vineyard) and Nantucket recognize that they are vulnerable to power supply interruptions due to their position at the end of the power grid, and due to sea level rise and other consequences of climate change. The tidal energy flowing through Muskeget Channel has been identified by the Electric Power Research Institute as the strongest tidal resource in Massachusetts waters. The Town of Edgartown proposes to develop an initial 5 MW (nameplate) tidal energy project in Muskeget Channel. The project will consist of 14 tidal turbines with 13 providing electricity to Edgartown and one operated by the University of Massachusetts at Dartmouth for research and development. Each turbine will be 90 feet long and 50 feet high. The electricity will be brought to shore by a submarine cable buried 8 feet below the seabed surface which will landfall in Edgartown either on Chappaquiddack or at Katama. Muskeget Channel is located between Martha�¢����s Vineyard and Nantucket. Its depth ranges between 40 and 160 feet in the deepest portion. It has strong currents where water is transferred between Nantucket Sound and the Atlantic Ocean continental shelf to the south. This makes it a treacherous passage for navigation. Current users of the channel are commercial and recreational fishing, and cruising boats. The US Coast Guard has indicated that the largest vessel passing through the channel is a commercial scallop dragger with a draft of about 10 feet. The tidal resource in the channel has been measured by the University of Massachusetts-Dartmouth and the peak velocity flow is approximately 5 knots. The technology proposed is the helical Gorlov-type turbine positioned with a horizontal axis that is positively buoyant in the water column and held down by anchors. This is the same technology proposed by Ocean Renewable Power Company in the Western Passage and Cobscook Bay near Eastport Maine. The blades rotate in two directions capturing the tides energy both during flood and ebb tides. The turbines will be anchored to the bottom and suspended in the water column. Initial depth of the turbines is expected to be about 25 feet below the surface to avoid impacting navigation while also capturing the strongest currents. The Town of Edgartown was initially granted a Preliminary Permit by the Federal Energy Regulatory Commission (FERC) on March 1, 2008, and has recently received a second permit valid through August 2014. The Preliminary Permit gives Edgartown the exclusive right to apply for a power generation license for power generated from the hydrokinetic energy in the water flowing in this area. Edgartown filed a Draft Pilot License Application with FERC on February 1, 2010 and an Expanded Environmental Notification Form with the Massachusetts Environmental Policy Act (MEPA) Office at the same time. It expects to file a Final License Application in late 2013. Harris Miller Miller & Hanson (HMMH) of Burlington Massachusetts is acting as the Project Manager for the Town of Edgartown and collaborating with other partners of the project including the University of Massachusetts - Dartmouth's Marine Renewable Energy Center and the Massachusetts Clean Energy Center. HMMH was awarded a grant under the Department of Energy's Advanced Water Program to conduct marine science and hydrokinetic site-specific environmental studies for projects actively seeking a FERC License. HMMH, on behalf of the Town, is managing this comprehensive study of the marine environment in Muskeget Channel and potential impacts of the tidal project on indicator species and habitats. The University of Massachusetts School of Marine Science and Technology (SMAST) conducted oceanographic studies of tidal currents, tide level, benthic habit

  3. analysing tidally induced: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Tidally-induced thermonuclear Supernovae Astrophysics (arXiv) Summary: We discuss the results of 3D simulations...

  4. Geomorphic structure of tidal hydrodynamics in salt marsh creeks

    E-Print Network [OSTI]

    Fagherazzi, Sergio

    of the tidal signal within the marsh area. Citation: Fagherazzi, S., M. Hannion, and P. D'Odorico (2008 by elegant hydrological and geomorphological theories [Gupta et al., 1980; Rodriguez-Iturbe and Valdes, 1979

  5. Nonrotating black hole in a post-Newtonian tidal environment

    E-Print Network [OSTI]

    Stephanne Taylor; Eric Poisson

    2008-09-11T23:59:59.000Z

    We examine the motion and tidal dynamics of a nonrotating black hole placed within a post-Newtonian external spacetime. The tidal perturbation created by the external environment is treated as a small perturbation. At a large distance from the black hole, the gravitational field of the external distribution of matter is assumed to be sufficiently weak to be adequately described by the (first) post-Newtonian approximation to general relativity. There, the black hole is treated as a monopole contribution to the total gravitational field. There exists an overlap in the domains of validity of each description, and the black-hole and post-Newtonian metrics are matched in the overlap. The matching procedure produces the equations of motion for the black hole and the gravito-electric and gravito-magnetic tidal fields acting on the black hole. We first calculate the equations of motion and tidal fields by making no assumptions regarding the nature of the post-Newtonian environment; this could contain a continuous distribution of matter or any number of condensed bodies. We next specialize our discussion to a situation in which the black hole is a member of a post-Newtonian two-body system. As an application of our results, we examine the geometry of the deformed event horizon and calculate the tidal heating of the black hole, the rate at which it acquires mass as a result of its tidal interaction with the companion body.

  6. MHK Projects/Indian River Tidal Hydrokinetic Energy Project | Open Energy

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy Resources Jump to:46 - 429Lacey,(MonasterLowell Point, Alaska:LuzClick here Current /TidalITRI WEC

  7. Ionization tube simmer current circuit

    DOE Patents [OSTI]

    Steinkraus, Jr., Robert F. (Livermore, CA)

    1994-01-01T23:59:59.000Z

    A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current.

  8. Ionization tube simmer current circuit

    DOE Patents [OSTI]

    Steinkraus, R.F. Jr.

    1994-12-13T23:59:59.000Z

    A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current. 6 figures.

  9. Using Tidal Tails to Probe Dark Matter Halos

    E-Print Network [OSTI]

    John Dubinski; J. Christopher Mihos; Lars Hernquist

    1995-09-04T23:59:59.000Z

    We use simulations of merging galaxies to explore the sensitivity of the morphology of tidal tails to variations of the halo mass distributions in the parent galaxies. Our goal is to constrain the mass of dark halos in well-known merging pairs. We concentrate on prograde encounters between equal mass galaxies which represent the best cases for creating tidal tails, but also look at systems with different relative orientations, orbital energies and mass ratios. As the mass and extent of the dark halo increase in the model galaxies, the resulting tidal tails become shorter and less massive, even under the most favorable conditions for producing these features. Our simulations imply that the observed merging galaxies with long tidal tails ($\\sim 50-100$ kpc) such as NGC 4038/39 (the Antennae) and NGC 7252 probably have halo:disk+bulge mass ratios less than 10:1. These results conflict with the favored values of the dark halo mass of the Milky Way derived from satellite kinematics and the timing argument which give a halo:disk+bulge mass ratio of $\\sim 30:1$. However, the lower bound of the estimated dark halo mass in the Milky Way (mass ratio $\\sim 10:1$) is still consistent with the inferred tidal tail galaxy masses. Our results also conflict with the expectations of $\\Omega=1$ cosmologies such as CDM which predict much more massive and extended dark halos.

  10. Nonlinear spherical Alfven waves

    E-Print Network [OSTI]

    Ulf Torkelsson; G. Christopher Boynton

    1997-09-23T23:59:59.000Z

    We present an one-dimensional numerical study of Alfven waves propagating along a radial magnetic field. Neglecting losses, any spherical Alfven wave, no matter how small its initial amplitude is, becomes nonlinear at sufficiently large radii. From previous simulations of Alfven waves in plane parallel atmospheres we did expect the waves to steepen and produce current sheets in the nonlinear regime, which was confirmed by our new calculations. On the other hand we did find that even the least nonlinear waves were damped out almost completely before 10 solar radii. A damping of that kind is required by models of Alfven wave-driven winds from old low-mass stars as these winds are mainly accelerated within a few stellar radii.

  11. TIDAL DISRUPTION FLARES: THE ACCRETION DISK PHASE

    SciTech Connect (OSTI)

    Montesinos Armijo, Matias; De Freitas Pacheco, Jose A. [Observatoire de la Cote d'Azur, Laboratoire Cassiopee, Universite de Nice Sophia-Antipolis Bd de l'Observatoire, BP 4229, 06304 Nice Cedex 4 (France)

    2011-08-01T23:59:59.000Z

    The evolution of an accretion disk, formed as a consequence of the disruption of a star by a black hole, is followed by solving numerically hydrodynamic equations. The present investigation aims to study the dependence of resulting light curves on dynamical and physical properties of such a transient disk during its existence. One of the main results derived from our simulations is that blackbody fits of X-ray data tend to overestimate the true mean disk temperature. In fact, the temperature derived from blackbody fits should be identified with the color X-ray temperature rather than the average value derived from the true temperature distribution along the disk. The time interval between the beginning of the circularization of the bound debris and the beginning of the accretion process by the black hole is determined by the viscous (or accretion) timescale, which also fixes the rising part of the resulting light curve. The luminosity peak coincides with the beginning of matter accretion by the black hole and the late evolution of the light curve depends on the evolution of the debris fallback rate. Peak bolometric luminosities are in the range 10{sup 45}-10{sup 46} erg s{sup -1}, whereas peak luminosities in soft X-rays (0.2-2.0 keV) are typically one order of magnitude lower. The typical timescale derived from our preferred models for the flare luminosity to decay by two orders of magnitude is about 3-4 yr. Predicted soft X-ray light curves reproduce quite well data on galaxies in which a variable X-ray emission possibly related to a tidal event was detected. In the cases of NGC 3599 and IC 3599, data are reproduced well by models defined by a black hole with mass {approx}10{sup 7} M{sub sun} and a disrupted star of about 1 solar mass. The X-ray variation observed in XMMSL1 is consistent with a model defined by a black hole with mass {approx}3 x 10{sup 6} M{sub sun} and a disrupted star of 1 solar mass, while that observed in the galaxy situated in the cluster A1689 is consistent with a model including a black hole of {approx}10{sup 7} M{sub sun} and a disrupted star of {approx}0.5 M{sub sun}.

  12. Resonant Oscillations and Tidal Heating in Coalescing Binary Neutron Stars

    E-Print Network [OSTI]

    Dong Lai

    1994-04-25T23:59:59.000Z

    Tidal interaction in a coalescing neutron star binary can resonantly excite the g-mode oscillations of the neutron star when the frequency of the tidal driving force equals the intrinsic g-mode frequencies. We study the g-mode oscillations of cold neutron stars using recent microscopic nuclear equations of state, where we determine self-consistently the sound speed and Brunt-V\\"ais\\"al\\"a frequency in the nuclear liquid core. The properties of the g-modes associated with the stable stratification of the core depend sensitively on the pressure-density relation as well as the symmetry energy of the dense nuclear matter. The frequencies of the first ten g-modes lie approximately in the range of $10-100$ Hz. Resonant excitations of these g-modes during the last few minutes of the binary coalescence result in energy transfer and angular momentum transfer from the binary orbit to the neutron star. The angular momentum transfer is possible because a dynamical tidal lag develops even in the absence of fluid viscosity. However, since the coupling between the g-mode and the tidal potential is rather weak, the amount of energy transfer during a resonance and the induced orbital phase error are very small. Resonant excitations of the g-modes play an important role in tidal heating of binary neutron stars. Without the resonances, viscous dissipation is effective only when the stars are close to contact. The resonant oscillations result in dissipation at much larger orbital separation. The actual amount of tidal heating depends on the viscosity of the neutron star. Using the microscopic viscosity, we find that the binary neutron stars are heated to a temperature $\\sim 10^8$ K before they come into contact.

  13. A Conceptual Restoration Plan and Tidal Hydrology Assessment for Reconnecting Spring Branch Creek to Suisun Marsh, Solano County, California

    E-Print Network [OSTI]

    Olson, Jessica J.

    2012-01-01T23:59:59.000Z

    Marsh. UC Berkeley LA 222 Hydrology Term Paper. Orr, M. , S.Restoration Plan and Tidal Hydrology Assessment forthree consists of a tidal hydrology analysis before and

  14. MHK Projects/Cohansey River Tidal Energy | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAK Technologies Jump to:BW2 Tidal <CETOCohansey River Tidal

  15. Natural and Restored Tidal Marshes Natural Marshes

    E-Print Network [OSTI]

    Boyer, Katharyn

    on reestablishment of hydrological func- tion to lands formerly diked for solar salt produc- tion or agriculture currently (see San Francisco Estu- ary Institute's Wetland Portal, http://www .californiawetlands.net/tracker

  16. 2011 Waves -1 STANDING WAVES

    E-Print Network [OSTI]

    Glashausser, Charles

    2011 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 the differences between transverse and longitudinal waves. APPARATUS: Buzzer board with string, meter stick

  17. Analysis of WACSIS data using a directional hybrid wave model

    E-Print Network [OSTI]

    Zhang, Shaosong

    2007-04-25T23:59:59.000Z

    .1 Backgrounds.........................................................................................1 1.2 Objectives.............................................................................................5 II DIRECTIONAL HYBRID WAVE MODEL... ......................................................................41 V ANALYSIS OF DIRECTIONAL WAVE FIELDS WITH STRONG CURRENT ...............................................................................................45 5.1 Introduction...

  18. TIDAL HEATING OF EXTRASOLAR PLANETS Brian Jackson, Richard Greenberg, and Rory Barnes

    E-Print Network [OSTI]

    Barnes, Rory

    TIDAL HEATING OF EXTRASOLAR PLANETS Brian Jackson, Richard Greenberg, and Rory Barnes Lunar and gas cleared away, and as the orbits evolved there was substantial tidal heating within the planets. The tidal heating history of each planet may have contributed significantly to the thermal budget governing

  19. Harmonic generation by reflecting internal waves Bruce Rodenborn, D. Kiefer, H. P. Zhang, and Harry L. Swinney

    E-Print Network [OSTI]

    Texas at Austin. University of

    Harmonic generation by reflecting internal waves Bruce Rodenborn, D. Kiefer, H. P. Zhang, and Harry 2011 The generation of internal gravity waves by tidal flow over topography is an important oceanic­Stokes equations to determine the value of the topographic slope that gives the most intense generation of second

  20. Electric Currents Electric Current

    E-Print Network [OSTI]

    Yu, Jaehoon

    ;Problem 3: At $0.095/kWh, what does it cost to leave a 25W porch light on day and night for a year = 219000 Watt- hour = 219kWh. So, total cost = 219 x$0.095 = $20.8 #12;Problem 4: A 100 W light bulb has of charge per unit time: = . Unit of current: Ampere (A). The purpose of a battery is to produce

  1. LOFT as a discovery machine for jetted Tidal Disruption Events

    E-Print Network [OSTI]

    Rossi, E M; Fender, R; Jonker, P; Komossa, S; Paragi, Z; Prandoni, I; Zampieri, L

    2015-01-01T23:59:59.000Z

    This is a White Paper in support of the mission concept of the Large Observatory for X-ray Timing (LOFT), proposed as a medium-sized ESA mission. We discuss the potential of LOFT for the study of jetted tidal disruption events. For a summary, we refer to the paper.

  2. Heartbeat Stars and the Ringing of Tidal Pulsations Kelly Hambleton

    E-Print Network [OSTI]

    Â?umer, Slobodan

    Heartbeat Stars and the Ringing of Tidal Pulsations Kelly Hambleton Andrej Prsa, Don Kurtz, Jim Fuller, Susan Thompson University of Central Lancashire kmhambleton@uclan.ac.uk March 27, 2014 Kelly 3 Summary Conclusions Future Work Kelly Hambleton (UCLan) Heartbeat Stars March 27, 2014 2 / 33 #12

  3. Tidal Stage Variability of Fecal Coliform and Chlorophyll a

    E-Print Network [OSTI]

    Mallin, Michael

    leachates, leaking sewer mains, wild and do- mestic animal wastes, and runo. However, the inter- action environmental hazards, to enter an estuarine environment characterized by high variability regarding temperature to understanding both the basic ecology of tidal creeks and the applied aspects of sampling protocols and pollutant

  4. Conformally curved binary black hole initial data including tidal deformations and outgoing radiation

    E-Print Network [OSTI]

    Nathan K. Johnson-McDaniel; Nicolas Yunes; Wolfgang Tichy; Benjamin J. Owen

    2009-07-06T23:59:59.000Z

    (Abridged) By asymptotically matching a post-Newtonian (PN) metric to two tidally perturbed Schwarzschild metrics, we generate approximate initial data (in the form of a 4-metric) for a nonspinning black hole binary in a circular orbit. We carry out this matching through O(v^4) in the binary's orbital velocity v, so the resulting data are conformally curved. Far from the holes, we use the appropriate PN metric that accounts for retardation, which we construct using the highest-order PN expressions available to compute the binary's past history. The data set's uncontrolled remainders are thus O(v^5) throughout the timeslice; we also generate an extension to the data set that has uncontrolled remainders of O(v^6) in the purely PN portion of the timeslice (i.e., not too close to the holes). The resulting data are smooth, since we join all the metrics together by smoothly interpolating between them. We perform this interpolation using transition functions constructed to avoid introducing excessive additional constraint violations. Due to their inclusion of tidal deformations and outgoing radiation, these data should substantially reduce the initial spurious ("junk") radiation observed in current simulations that use conformally flat initial data. Such reductions in the nonphysical components of the initial data will be necessary for simulations to achieve the accuracy required to supply Advanced LIGO and LISA with the templates necessary for parameter estimation.

  5. Exploration applications of a transgressive tidal flats model to Mississippian Midale carbonates, eastern Williston Basin

    SciTech Connect (OSTI)

    Porter, L.A.; Reid, R.S.R.

    1985-05-01T23:59:59.000Z

    Midale (Mississippian) production was first established in 1953 in Saskatchewan, Canada. The unit was initially defined in the subsurface as the carbonate interval between the top of the Frobisher Anhydrite and the base of the Midale Anhydrite. That nomenclature is used in this report. During 1953, Midale production was found in the United States portion of the Williston basin in Bottineau County, North Dakota. Later exploration extended Midale production westward into Burke County, North Dakota. Cumulative production from the Midale is approximately 660 million bbl, of which 640 million bbl are from Canadian fields. Initially, hydrocarbon entrapment in the Midale was believed to be controlled by the Mississippian subcrop, with the Burke County production controlled by low-relief structural closure. Petrographic examination of cores and cuttings from the Midale in both Saskatchewan, Canada, and Burke and Bottineau Counties, North Dakota, indicates that production is controlled by facies changes within the unit. Stratigraphic traps are formed by the lateral and vertical changes from grain-supported facies deposited in tidal channel, subtidal bar, or beach settings; seals are formed by mud-rich sediments. Use of a transgressive carbonate tidal flats model best explains current production patterns and indicates substantial potential for additional production in eastern North Dakota and South Dakota.

  6. Exploration applications of a transgressive tidal-flats model to Mississippian Midale carbonates, eastern Williston Basin

    SciTech Connect (OSTI)

    Porter, L.A.; Reid, F.S.

    1985-02-01T23:59:59.000Z

    Midale (Mississippian) production was first indicated in 1953 in Saskatchewan, Canada. The unit was initially defined in the subsurface as the carbonate interval between the top of the Frobisher Anhydrite and the base of the Midale Anhydrite. This same nomenclature is used in this paper. In 1953, Midale production was found on the US side of the Williston basin in Bottineau County, North Dakota. Later exploration extended Midale production westward into Burke County, North Dakota, in 1955. Cumulative production from the Midale is approximately 660 million bbl with 640 million from the Canadian side of the Williston basin. Initially, hydrocarbon entrapment in the Midale was believed to be controlled by the Mississippian subcrop, with the Burke County production controlled by low-relief structural closure. Petrographic examination of cores and cuttings from the Midale in both Saskatchewan, Canada, and Burke and Bottineau Counties, North Dakota, indicates that production is controlled by facies changes within the unit. Stratigraphic traps are formed by the lateral and vertical changes from grain-supported facies deposited in tidal-channel, subtidal-bar, or beach settings; seals are formed by mud-rich sediments. Use of a transgressive carbonate tidal-flats model best explains current production patterns and indicates substantial potential for additional production in eastern North Dakota and South Dakota.

  7. Formation of planetary debris discs around white dwarfs I: Tidal disruption of an extremely eccentric asteroid

    E-Print Network [OSTI]

    Veras, Dimitri; Bonsor, Amy; Gaensicke, Boris T

    2014-01-01T23:59:59.000Z

    25%-50% of all white dwarfs (WDs) host observable and dynamically active remnant planetary systems based on the presence of close-in circumstellar dust and gas and photospheric metal pollution. Currently-accepted theoretical explanations for the origin of this matter include asteroids that survive the star's giant branch evolution at au-scale distances and are subsequently perturbed onto WD-grazing orbits following stellar mass loss. In this work we investigate the tidal disruption of these highly-eccentric (e > 0.98) asteroids as they approach and tidally disrupt around the WD. We analytically compute the disruption timescale and compare the result with fully self-consistent numerical simulations of rubble piles by using the N-body code PKDGRAV. We find that this timescale is highly dependent on the orbit's pericentre and largely independent of its semimajor axis. We establish that spherical asteroids readily break up and form highly eccentric collisionless rings, which do not accrete onto the WD without add...

  8. ULTRAVIOLET/OPTICAL/INFRARED COLOR SEQUENCES ALONG THE TIDAL RING/ARM OF Arp 107

    SciTech Connect (OSTI)

    Lapham, Ryen C.; Smith, Beverly J. [Department of Physics and Astronomy, East Tennessee State University, Johnson City, TN 37614 (United States); Struck, Curtis, E-mail: rlapham@nmt.edu, E-mail: smithbj@etsu.edu, E-mail: curt@iastate.edu [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States)

    2013-05-15T23:59:59.000Z

    We construct UV/optical/IR spectral energy distributions for 29 star forming regions in the interacting galaxy Arp 107, using GALEX UV, Sloan Digitized Sky Survey optical, and Spitzer infrared images. In an earlier study utilizing only the Spitzer data, we found a sequence in the mid-infrared colors of star-forming knots along the strong tidal arm in this system. In the current study, we find sequences in the UV/optical colors along the tidal arm that mirror those in the mid-infrared, with blue UV/optical colors found for regions that are red in the mid-infrared, and vice versa. With single-burst stellar population synthesis models, we find a sequence in the average stellar age along this arm, with younger stars preferentially located further out in the arm. Models that allow two populations of different ages and dust attenuations suggest that there may be both a young component and an older population present in these regions. Thus the observed color sequences may be better interpreted as a sequence in the relative proportion of young and old stars along the arm, with a larger fraction of young stars near the end. Comparison with star forming regions in other interacting galaxies shows that the Arp 107 regions are relatively quiescent, with less intense star formation than in many other systems.

  9. Modeling In-stream Tidal Energy Extraction and Its Potential Environmental Impacts

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Wang, Taiping; Copping, Andrea; Geerlofs, Simon H.

    2014-09-30T23:59:59.000Z

    In recent years, there has been growing interest in harnessing in-stream tidal energy in response to concerns of increasing energy demand and to mitigate climate change impacts. While many studies have been conducted to assess and map tidal energy resources, efforts for quantifying the associated potential environmental impacts have been limited. This paper presents the development of a tidal turbine module within a three-dimensional unstructured-grid coastal ocean model and its application for assessing the potential environmental impacts associated with tidal energy extraction. The model is used to investigate in-stream tidal energy extraction and associated impacts on estuarine hydrodynamic and biological processes in a tidally dominant estuary. A series of numerical experiments with varying numbers and configurations of turbines installed in an idealized estuary were carried out to assess the changes in the hydrodynamics and biological processes due to tidal energy extraction. Model results indicated that a large number of turbines are required to extract the maximum tidal energy and cause significant reduction of the volume flux. Preliminary model results also indicate that extraction of tidal energy increases vertical mixing and decreases flushing rate in a stratified estuary. The tidal turbine model was applied to simulate tidal energy extraction in Puget Sound, a large fjord-like estuary in the Pacific Northwest coast.

  10. Atmospheric heat redistribution and collapse on tidally locked rocky planets

    E-Print Network [OSTI]

    Wordsworth, Robin

    2014-01-01T23:59:59.000Z

    Atmospheric collapse is likely to be of fundamental importance to tidally locked rocky exoplanets but remains understudied. Here, general results on the heat transport and stability of tidally locked terrestrial-type atmospheres are reported. First, the problem is modeled with an idealized 3D general circulation model (GCM) with gray gas radiative transfer. It is shown that over a wide range of parameters the atmospheric boundary layer, rather than the large-scale circulation, is the key to understanding the planetary energy balance. Through a scaling analysis of the interhemispheric energy transfer, theoretical expressions for the day-night temperature difference and surface wind speed are created that reproduce the GCM results without tuning. Next, the GCM is used with correlated-k radiative transfer to study heat transport for two real gases (CO2 and CO). For CO2, empirical formulae for the collapse pressure as a function of planetary mass and stellar flux are produced, and critical pressures for atmospher...

  11. Spatial motion of the Magellanic Clouds. Tidal models ruled out?

    E-Print Network [OSTI]

    Ruzicka, Adam; Palous, Jan

    2008-01-01T23:59:59.000Z

    Recently, Kallivayalil et al. derived new values of the proper motion for the Large and Small Magellanic Clouds (LMC and SMC, respectively). The spatial velocities of both Clouds are unexpectedly higher than their previous values resulting from agreement between the available theoretical models of the Magellanic System and the observations of neutral hydrogen (HI) associated with the LMC and the SMC. Such proper motion estimates are likely to be at odds with the scenarios for creation of the large-scale structures in the Magellanic System suggested so far. We investigated this hypothesis for the pure tidal models, as they were the first ones devised to explain the evolution of the Magellanic System, and the tidal stripping is intrinsically involved in every model assuming the gravitational interaction. The parameter space for the Milky Way (MW)-LMC-SMC interaction was analyzed by a robust search algorithm (genetic algorithm) combined with a fast restricted N-body model of the interaction. Our method extended ...

  12. Investigation of tidal power, Cobscook Bay, Maine. Environmental Appendix

    SciTech Connect (OSTI)

    Not Available

    1980-08-01T23:59:59.000Z

    This report presents information regarding existing terrestrial and marine resources and water quality conditions in the Cobscook Bay area. A preliminary assessment of impacts from a tidal power project is also presented and data gaps are identified. Reports contained in the appendix were prepared by the U.S. Fish and Wildlife Service, the National Marine Fisheries Service, the University of Maine at Orino, School of Forestry Resources and the U.S. Army Corps of Engineers.

  13. Extremely Close-In Giant Planets from Tidal Capture

    E-Print Network [OSTI]

    B. Scott Gaudi

    2003-07-15T23:59:59.000Z

    Planets that form around stars born in dense stellar environments are subject to dynamical perturbations from other stars in the system. These perturbations will strip outer planets, forming a population of free-floating planets, some of which will be tidally captured before they evaporate from the system. For systems with velocity dispersion of 1 km/s, Jupiter-mass planets can be captured into orbits with periods of 0.1-0.4 days, which are generally stable over a Gyr, assuming quadratic suppression of eddy viscosity in the convective zones of the host stars. Under this assumption, and that most stars form several massive planets at separations 5-50 AU, about 0.03% of stars in rich, mature open clusters should have extremely close-in tidally captured planets. Approximately 0.005% of field stars should also have such planets, which may be found in field searches for transiting planets. Detection of a population of tidally-captured planets would indicate that most stars formed in stellar clusters. In globular clusters, the fraction of stars with tidally-captured planets rises to 0.1% -- in conflict with the null result of the transit search in 47 Tuc. This implies that, if the quadratic prescription for viscosity suppression is correct, planetary formation was inhibited in 47 Tuc: less than one planet of Jupiter-mass or greater (bound or free-floating) formed per cluster star. Less than half of the stars formed solar-system analogs. Brown dwarfs can also be captured in tight orbits; the lack of such companions in 47 Tuc in turn implies an upper limit on the initial frequency of brown dwarfs in this cluster. However, this upper limit is extremely sensitive to the highly uncertain timescale for orbital decay, and thus it is difficult to draw robust conclusions about the low-mass end of the mass function in 47 Tuc.

  14. EA-1949: Admiralty Inlet Pilot Tidal Project, Puget Sound, WA

    Broader source: Energy.gov [DOE]

    This EA analyzes the potential environmental effects of a proposal by the Public Utility District No. 1 of Snohomish County, Washington to construct and operate the Admiralty Inlet Tidal Project. The proposed 680-kilowatt project would be located on the east side of Admiralty Inlet in Puget Sound, Washington, about 1 kilometer west of Whidbey Island, entirely within Island County, Washington. The Federal Energy Regulatory Commission (FERC) is the lead agency. The DOE NEPA process for this project has been canceled.

  15. Nonlinear dust acoustic waves and shocks

    SciTech Connect (OSTI)

    Merlino, R. L.; Heinrich, J. R.; Hyun, S.-H.; Meyer, J. K. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States)

    2012-05-15T23:59:59.000Z

    We describe experiments on (1) nonlinear dust acoustic waves and (2) dust acoustic shocks performed in a direct current (DC) glow discharge dusty plasma. First, we describe experiments showing nonlinear dust acoustic waves characterized by waveforms of the dust density that are typically sharper in the wave crests and flatter in the wave troughs (compared to sinusoidal waves), indicating the development of wave harmonics. We discuss this behavior in terms of a second-order fluid theory for dust acoustic waves. Second, experimental observations of the propagation and steepening of large-amplitude dust acoustic waves into dust acoustic shock waves are presented. The observed shock wave evolution is compared with numerical calculations based on the Riemann solution of the fully nonlinear fluid equations for dust acoustic waves.

  16. Resonant oscillations and tidal heating in coalescing binary neutron stars

    E-Print Network [OSTI]

    Lai, D

    1994-01-01T23:59:59.000Z

    Tidal interaction in a coalescing neutron star binary can resonantly excite the g-mode oscillations of the neutron star when the frequency of the tidal driving force equals the intrinsic g-mode frequencies. We study the g-mode oscillations of cold neutron stars using recent microscopic nuclear equations of state, where we determine self-consistently the sound speed and Brunt-V\\"ais\\"al\\"a frequency in the nuclear liquid core. The properties of the g-modes associated with the stable stratification of the core depend sensitively on the pressure-density relation as well as the symmetry energy of the dense nuclear matter. The frequencies of the first ten g-modes lie approximately in the range of 10-100 Hz. Resonant excitations of these g-modes during the last few minutes of the binary coalescence result in energy transfer and angular momentum transfer from the binary orbit to the neutron star. The angular momentum transfer is possible because a dynamical tidal lag develops even in the absence of fluid viscosity. ...

  17. Tidal Capture of Stars by Intermediate-Mass Black Holes

    E-Print Network [OSTI]

    H. Baumgardt; C. Hopman; S. Portegies Zwart; J. Makino

    2005-11-27T23:59:59.000Z

    Recent X-ray observations and theoretical modelling have made it plausible that some ultraluminous X-ray sources (ULX) are powered by intermediate-mass black holes (IMBHs). N-body simulations have also shown that runaway merging of stars in dense star clusters is a way to form IMBHs. In the present paper we have performed N-body simulations of young clusters such as MGG-11 of M82 in which IMBHs form through runaway merging. We took into account the effect of tidal heating of stars by the IMBH to study the tidal capture and disruption of stars by IMBHs. Our results show that the IMBHs have a high chance of capturing stars through tidal heating within a few core relaxation times and we find that 1/3 of all runs contain a ULX within the age limits of MGG-11, a result consistent with the fact that a ULX is found in this galaxy. Our results strengthen the case for some ULX being powered by intermediate-mass black holes.

  18. Modeling Tidal Streams in evolving dark matter halos

    E-Print Network [OSTI]

    Jorge Penarrubia; Andrew J. Benson; David Martinez-Delgado; Hans-Walter Rix

    2005-12-20T23:59:59.000Z

    We explore whether stellar tidal streams can provide information on the secular, cosmological evolution of the Milky Way's gravitational potential and on the presence of subhalos. We carry out long-term (~t_hubble) N-body simulations of disrupting satellite galaxies in a semi-analytic Galaxy potential where the dark matter halo and the subhalos evolve according to a LCDM cosmogony. All simulations are constrained to end up with the same position and velocity at present. Our simulations account for: (i) the secular evolution of the host halo's mass, size and shape, (ii) the presence of subhalos and (iii) dynamical friction. We find that tidal stream particles respond adiabatically to the Galaxy growth so that, at present, the energy and angular momentum distribution is exclusively determined by the present Galaxy potential. In other words, all present-day observables can only constrain the present mass distribution of the Galaxy independent of its past evolution. We also show that, if the full phase-space distribution of a tidal stream is available, we can accurately determine (i) the present Galaxy's shape and (ii) the amount of mass loss from the stream's progenitor, even if this evolution spanned a cosmologically significant epoch.

  19. Tidal Heating of Terrestrial Extra-Solar Planets and Implications for their Habitability

    E-Print Network [OSTI]

    Brian Jackson; Rory Barnes; Richard Greenberg

    2008-08-20T23:59:59.000Z

    The tidal heating of hypothetical rocky (or terrestrial) extra-solar planets spans a wide range of values depending on stellar masses and initial orbits. Tidal heating may be sufficiently large (in many cases, in excess of radiogenic heating) and long-lived to drive plate tectonics, similar to the Earth's, which may enhance the planet's habitability. In other cases, excessive tidal heating may result in Io-like planets with violent volcanism, probably rendering them unsuitable for life. On water-rich planets, tidal heating may generate sub-surface oceans analogous to Europa's with similar prospects for habitability. Tidal heating may enhance the outgassing of volatiles, contributing to the formation and replenishment of a planet's atmosphere. To address these issues, we model the tidal heating and evolution of hypothetical extra-solar terrestrial planets. The results presented here constrain the orbital and physical properties required for planets to be habitable.

  20. MHK Technologies/Uldolmok Pilot Tidal Current Power Plant | Open Energy

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAKGalway Bay IEOWC <SurgeWECSailsOWC.png TechnologyUFCAP

  1. Establishing a Testing Center for Ocean Energy Technologies in...

    Broader source: Energy.gov (indexed) [DOE]

    range of capabilities to support wave and tidal energy development for the United States. Ocean energy, generated from waves, tides, and currents, can be harnessed wherever...

  2. Assessment of Strike of Adult Killer Whales by an OpenHydro Tidal Turbine Blade

    SciTech Connect (OSTI)

    Carlson, Thomas J.; Elster, Jennifer L.; Jones, Mark E.; Watson, Bruce E.; Copping, Andrea E.; Watkins, Michael L.; Jepsen, Richard A.; Metzinger, Kurt

    2012-02-01T23:59:59.000Z

    Report to DOE on an analysis to determine the effects of a potential impact to an endangered whale from tidal turbines proposed for deployment in Puget Sound.

  3. Modeling the Effects of Tidal Energy Extraction on Estuarine Hydrodynamics in a Stratified Estuary

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Wang, Taiping

    2013-08-15T23:59:59.000Z

    A three-dimensional coastal ocean model with a tidal turbine module was used in this paper to study the effects of tidal energy extraction on temperature and salinity stratification and density driven two-layer estuarine circulation. Numerical experiments with various turbine array configurations were carried out to investigate the changes in tidally mean temperature, salinity and velocity profiles in an idealized stratified estuary that connects to coastal water through a narrow tidal channel. The model was driven by tides, river inflow and sea surface heat flux. To represent the realistic size of commercial tidal farms, model simulations were conducted based on a small percentage of the total number of turbines that would generate the maximum extractable energy in the system. Model results indicated that extraction of tidal energy will increase the vertical mixing and decrease the stratification in the estuary. Extraction of tidal energy has stronger impact on the tidally-averaged salinity, temperature and velocity in the surface layer than the bottom. Energy extraction also weakens the two-layer estuarine circulation, especially during neap tides when tidal mixing the weakest and energy extraction is the smallest. Model results also show that energy generation can be much more efficient with higher hub height with relatively small changes in stratification and two-layer estuarine circulation.

  4. Current ramp-up with lower hybrid current drive in EAST B. J. Ding,1

    E-Print Network [OSTI]

    Current ramp-up with lower hybrid current drive in EAST B. J. Ding,1 M. H. Li,1 N. J. Fisch,2 H hybrid current drive. The first stage of cyclic operation would be to ramp up the plasma current with lower hybrid waves alone in low-density plasma. Such a current ramp-up was carried out successfully

  5. Intrusive gravity currents in two-layer

    E-Print Network [OSTI]

    Flynn, Morris R.

    Intrusive gravity currents in two-layer stratified media Morris R. Flynn & Paul F. Linden Dept to as a gravity current · In contrast to waves, gravity currents transport significant mass (e.g. fluid parcels, sediment, insects, etc.) Introduction Gravity currents in the environment www

  6. Current separation and upwelling over the southeast shelf of Vietnam in the South China Sea

    E-Print Network [OSTI]

    Chen, Changsheng

    ] The high-resolution, unstructured grid Finite-Volume Community Ocean Model (FVCOM) was used to examine-shelf coastal current from the north and northeastward buoyancy-driven and stratified tidal-rectified currents, is capable of reproducing the location and tongue-like offshore distribution of temperature as those seen

  7. Near wake properties of horizontal axis marine current L. Myers and A.S. Bahaj

    E-Print Network [OSTI]

    Quartly, Graham

    1 Near wake properties of horizontal axis marine current turbines L. Myers and A.S. Bahaj wake region of a tidal current turbine is strongly driven by the combined wake of the device support-scale horizontal axis turbine has been have been measured in a large water channel facility. A downstream map

  8. A Systemic Design Methodology of PM Generators for Fixed-Pitch Marine Current Turbines

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    A Systemic Design Methodology of PM Generators for Fixed-Pitch Marine Current Turbines Sofiane of permanent magnet (PM) generator associated with fixed-pitch turbine for tidal energy generation. The main problem with marine current turbines systems are the maintenance requirements of the drive

  9. MHK Projects/BW2 Tidal | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAK Technologies Jump to:BW2 Tidal < MHK Projects Jump to:

  10. MHK Projects/Cape May Tidal Energy | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAK Technologies Jump to:BW2 Tidal <CETO La ReunionCape

  11. MHK Projects/Cuttyhunk Tidal Energy Plant | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAK Technologies Jump to:BW2 Tidal <CETOCohanseyHub <

  12. MHK Projects/Deception Pass Tidal Energy Hydroelectric Project | Open

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAK Technologies Jump to:BW2 Tidal

  13. MHK Projects/Dorchester Maurice Tidal | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAK Technologies Jump to:BW2 TidalMar Landing <

  14. MHK Projects/East Foreland Tidal Energy | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAK Technologies Jump to:BW2 TidalMar Landing <DouglasForeland

  15. MHK Projects/Gastineau Channel Tidal | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAK Technologies Jump to:BW2 TidalMarFalmouthVinalhaven ME

  16. MHK Projects/Wiscasset Tidal Energy Plant | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAKGalway Bay IE < MHKInformation BretonMOWiscasset Tidal

  17. MHK Technologies/Deep Gen Tidal Turbines | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAKGalway Bay IE <AirWEC < MHK<Tidal Turbines < MHK

  18. MHK Technologies/KESC Tidal Generator | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAKGalway Bay IE <AirWECHelix <IWAVE < MHKKESC Tidal

  19. MHK Technologies/Rotech Tidal Turbine RTT | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAKGalway Bay IEOWC < MHKPulse-Stream 120 < MHKRotech Tidal

  20. MHK Technologies/Tidal Barrage | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAKGalway Bay IEOWC <SurgeWEC <Generator.jpgTheTidal

  1. MHK Technologies/Tidal Delay | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAKGalway Bay IEOWC <SurgeWEC <Generator.jpgTheTidalDelay

  2. MHK Technologies/Tidal Hydraulic Generators THG | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAKGalway Bay IEOWC <SurgeWEC <Generator.jpgTheTidalDelayTHG

  3. Hydra Tidal Energy Technology AS | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy Resources Jump to: navigation,Ohio:GreerHiCalifornia: Energy ResourcesPark,is aHy9Hydesville,Hydra Tidal

  4. 1 | September 2013 | des courantsWave energyTidal turbines

    E-Print Network [OSTI]

    performance and the ability to maintain this performance through the lifetime of the power plant, at a high Symposium Honolulu ­ Hawaï sept 2013 Floating offshore wind Ocean thermal energy conversion DCNS - Ocean of the adopted technical solutions using both numerical simulations and representative trials. From their adpoted

  5. Energy Department Invests $16 Million to Harness Wave and Tidal Energy |

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:Year in Review: TopEnergyIDIQBusiness Competition |StorageAbengoaEnergyFunding

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy Usage »of Energy StrainClient updateTRI-STATE GENERATION

  7. Southern/Northern California Coastal Processes Annotated Bibliography: Coast of California Storm and Tidal Waves Study

    E-Print Network [OSTI]

    US Army Corps of Engineers, Los Angeles District, Planning Division, Coastal Resources Branch

    1987-01-01T23:59:59.000Z

    Reach Coast of California, Carpinteria to Point Mugu, BeachCell Coast of California, Carpinteria to Point Mugu, Beach1, Coast of California, Carpinteria to Point Mugu, Beach

  8. Constraining the neutron star equation of state with gravitational wave signals from coalescing binary neutron stars

    E-Print Network [OSTI]

    Michalis Agathos; Jeroen Meidam; Walter Del Pozzo; Tjonnie G. F. Li; Marco Tompitak; John Veitch; Salvatore Vitale; Chris Van Den Broeck

    2015-03-18T23:59:59.000Z

    Recently exploratory studies were performed on the possibility of constraining the neutron star equation of state (EOS) using signals from coalescing binary neutron stars, or neutron star-black hole systems, as they will be seen in upcoming advanced gravitational wave detectors such as Advanced LIGO and Advanced Virgo. In particular, it was estimated to what extent the combined information from multiple detections would enable one to distinguish between different equations of state through hypothesis ranking or parameter estimation. Under the assumption of zero neutron star spins both in signals and in template waveforms and considering tidal effects to 1PN order, it was found that O(20) sources would suffice to distinguish between a hard, moderate, and soft equation of state. Here we revisit these results, this time including neutron star tidal effects to the highest order currently known, termination of gravitational waveforms at the contact frequency, neutron star spins, and the resulting quadrupole-monopole interaction. We also take the masses of neutron stars in simulated sources to be distributed according to a relatively strongly peaked Gaussian, as hinted at by observations, but without assuming that the data analyst will necessarily have accurate knowledge of this distribution for use as a mass prior. We find that especially the effect of the latter is dramatic, necessitating many more detections to distinguish between different EOS and causing systematic biases in parameter estimation, on top of biases due to imperfect understanding of the signal model pointed out in earlier work. This would get mitigated if reliable prior information about the mass distribution could be folded into the analyses.

  9. A Tidal Hydrology Assessment for Reconnecting Spring Branch Creek to Suisun Marsh, Solano County CA: Predicting the Impact to the Federally Listed Plant Soft Bird's Beak

    E-Print Network [OSTI]

    Olson, Jessica J.

    2011-01-01T23:59:59.000Z

    this study. Changes in hydrology are not the only potentialA Tidal Hydrology Assessment for Reconnecting Spring Branchmay change the tidal hydrology and impact the area occupied

  10. Vacuum Waves

    E-Print Network [OSTI]

    Paul S. Wesson

    2012-12-11T23:59:59.000Z

    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.

  11. Intracranial Pressure Variation Associated with Changes in End-Tidal CO2

    E-Print Network [OSTI]

    Intracranial Pressure Variation Associated with Changes in End-Tidal CO2 Sunghan Kim, James Mc that the partial pressure of arterial CO2 (PaCO2) can affect cerebral blood flow, cerebral blood volume, and therefore ICP. The end-tidal CO2 (ETCO2) is usually monitored by clinicians as a proxy for PaCO2. We show

  12. Mercury Dynamics in a San Francisco Estuary Tidal Wetland: Assessing Dynamics Using In Situ Measurements

    E-Print Network [OSTI]

    Boss, Emmanuel S.

    Mercury Dynamics in a San Francisco Estuary Tidal Wetland: Assessing Dynamics Using In Situ the tidally driven exchange of mercury (Hg) between the waters of the San Francisco estuary and Browns Island, respectively--together predicted 94 % of the observed variability in measured total mercury concentra- tion

  13. The Magellanic Bridge: The Nearest Purely Tidal Stellar Population

    E-Print Network [OSTI]

    Jason Harris

    2006-12-04T23:59:59.000Z

    We report on observations of the stellar populations in twelve fields spanning the region between the Magellanic Clouds, made with the Mosaic-II camera on the 4-meter telescope at the Cerro-Tololo Inter-American Observatory. The two main goals of the observations are to characterize the young stellar population (which presumably formed in situ in the Bridge and therefore represents the nearest stellar population formed from tidal debris), and to search for an older stellar component (which would have been stripped from either Cloud as stars, by the same tidal forces which formed the gaseous Bridge). We determine the star-formation history of the young inter-Cloud population, which provides a constraint on the timing of the gravitational interaction which formed the Bridge. We do not detect an older stellar population belonging to the Bridge in any of our fields, implying that the material that was stripped from the Clouds to form the Magellanic Bridge was very nearly a pure gas.

  14. Dynamical resonance locking in tidally interacting binary systems

    E-Print Network [OSTI]

    Joshua Burkart; Eliot Quataert; Phil Arras

    2014-10-25T23:59:59.000Z

    We examine the dynamics of resonance locking in detached, tidally interacting binary systems. In a resonance lock, a given stellar or planetary mode is trapped in a highly resonant state for an extended period of time, during which the spin and orbital frequencies vary in concert to maintain the resonance. This phenomenon is qualitatively similar to resonance capture in planetary dynamics. We show that resonance locks can accelerate the course of tidal evolution in eccentric systems and also efficiently couple spin and orbital evolution in circular binaries. Previous analyses of resonance locking have not treated the mode amplitude as a fully dynamical variable, but rather assumed the adiabatic (i.e. Lorentzian) approximation valid only in the limit of relatively strong mode damping. We relax this approximation, analytically derive conditions under which the fixed point associated with resonance locking is stable, and further check these analytic results using numerical integrations of the coupled mode, spin, and orbital evolution equations. These show that resonance locking can sometimes take the form of complex limit cycles or even chaotic trajectories. We provide simple analytic formulae that define the binary and mode parameter regimes in which resonance locks of some kind occur (stable, limit cycle, or chaotic). We briefly discuss the astrophysical implications of our results for white dwarf and neutron star binaries as well as eccentric stellar binaries.

  15. Tidal deformation of a slowly rotating material body. I. External metric

    E-Print Network [OSTI]

    Landry, Philippe

    2015-01-01T23:59:59.000Z

    We construct the external metric of a slowly rotating, tidally deformed material body in general relativity. The tidal forces acting on the body are assumed to be weak and to vary slowly with time, and the metric is obtained as a perturbation of a background metric that describes the external geometry of an isolated, slowly rotating body. The tidal environment is generic and characterized by two symmetric-tracefree tidal moments E_{ab} and B_{ab}, and the body is characterized by its mass M, its radius R, and a dimensionless angular-momentum vector \\chi^a environment requires the introduction of four new quantities, which we designate as rotational-tidal Love numbers. All these Love numbers are gauge ...

  16. Current Rusume

    E-Print Network [OSTI]

    2015-02-09T23:59:59.000Z

    Research Interest Rough paths theory, Stochastic differential equations, ... I am currently working on a problem about stochastic analysis on Riemannian folia-.

  17. Modeling Tidal Stream Energy Extraction and its Effects on Transport Processes in a Tidal Channel and Bay System Using a Three-dimensional Coastal Ocean Model

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Wang, Taiping; Copping, Andrea E.

    2013-02-28T23:59:59.000Z

    This paper presents a numerical modeling study for simulating in-stream tidal energy extraction and assessing its effects on the hydrodynamics and transport processes in a tidal channel and bay system connecting to coastal ocean. A marine and hydrokinetic (MHK) module was implemented in a three-dimensional (3-D) coastal ocean model using the momentum sink approach. The MHK model was validated with the analytical solutions for tidal channels under one-dimensional (1-D) conditions. Model simulations were further carried out to compare the momentum sink approach with the quadratic bottom friction approach. The effects of 3-D simulations on the vertical velocity profile, maximum extractable energy, and volume flux reduction across the channel were investigated through a series of numerical experiments. 3-D model results indicate that the volume flux reduction at the maximum extractable power predicted by the 1-D analytical model or two-dimensional (2-D) depth-averaged numerical model may be overestimated. Maximum extractable energy strongly depends on the turbine hub height in the water column, and which reaches a maximum when turbine hub height is located at mid-water depth. Far-field effects of tidal turbines on the flushing time of the tidal bay were also investigated. Model results demonstrate that tidal energy extraction has a greater effect on the flushing time than volume flux reduction, which could negatively affect the biogeochemical processes in estuarine and coastal waters that support primary productivity and higher forms of marine life.

  18. Primordial Gravitational Waves Enhancement

    E-Print Network [OSTI]

    Maria G. Romania; N. C. Tsamis; R. P. Woodard

    2011-08-08T23:59:59.000Z

    We reconsider the enhancement of primordial gravitational waves that arises from a quantum gravitational model of inflation. A distinctive feature of this model is that the end of inflation witnesses a brief phase during which the Hubble parameter oscillates in sign, changing the usual Hubble friction to anti-friction. An earlier analysis of this model was based on numerically evolving the graviton mode functions after guessing their initial conditions near the end of inflation. The current study is based on an equation which directly evolves the normalized square of the magnitude. We are also able to make a very reliable estimate for the initial condition using a rapidly converging expansion for the sub-horizon regime. Results are obtained for the energy density per logarithmic wave number as a fraction of the critical density. These results exhibit how the enhanced signal depends upon the number of oscillatory periods; they also show the resonant effects associated with particular wave numbers.

  19. Shock wave propagation in composites and active Vinamra Agrawal

    E-Print Network [OSTI]

    Shyamasundar, R.K.

    Shock wave propagation in composites and active Vinamra Agrawal California Institute of Technology travel through a material. These waves are characterized as a discontinuity propagating through shock waves propagate in heterogeneous materials. Shock waves are also being used to o pulsed currents

  20. Tidal Downsizing model. II. Planet-metallicity correlations

    E-Print Network [OSTI]

    Nayakshin, Sergei

    2015-01-01T23:59:59.000Z

    Core Accretion (CA), the de-facto accepted theory of planet formation, requires formation of massive solid cores as a prerequisite for assembly of gas giant planets. The observed metallicity correlations of exoplanets are puzzling in the context of CA. While gas giant planets are found preferentially around metal-rich host stars, planets smaller than Neptune orbit hosts with a wide range of metallicities. We propose an alternative interpretation of these observations in the framework of a recently developed planet formation hypothesis called Tidal Downsizing (TD). We perform population synthesis calculations based on TD, and find that the connection between the populations of the gas giant and the smaller solid-core dominated planets is non linear and not even monotonic. While gas giant planets formed in the simulations in the inner few AU region follow a strong positive correlation with the host star metallicity, the smaller planets do not. The simulated population of these smaller planets shows a shallow pe...

  1. Circularization of Tidally Disrupted Stars around Spinning Supermassive Black Holes

    E-Print Network [OSTI]

    Hayasaki, Kimitake; Loeb, Abraham

    2015-01-01T23:59:59.000Z

    We study the circularization of tidally disrupted stars on bound orbits around spinning supermassive black holes by performing three-dimensional smoothed particle hydrodynamic simulations with Post-Newtonian corrections. Our simulations reveal that debris circularization depends sensitively on the efficiency of radiative cooling. There are two stages in debris circularization if radiative cooling is inefficient: first, the stellar debris streams self-intersect due to relativistic apsidal precession; shocks at the intersection points thermalize orbital energy and the debris forms a geometrically thick, ring-like structure around the black hole. The ring rapidly spreads via viscous diffusion, leading to the formation of a geometrically thick accretion disk. In contrast, if radiative cooling is efficient, the stellar debris circularizes due to self-intersection shocks and forms a geometrically thin ring-like structure. In this case, the dissipated energy can be emitted during debris circularization as a precurso...

  2. SPH simulations of tidally unstable accretion disks in cataclysmic variables

    E-Print Network [OSTI]

    James R. Murray

    1995-11-08T23:59:59.000Z

    We numerically study the precessing disk model for superhump in the SU~UMa subclass of cataclysmic variables, using a two dimensional SPH code specifically designed for thin disk problems. Two disk simulations for a binary with mass ratio $q=\\frac{3}{17}$ (similar to OY~Car) are performed, in order to investigate the Lubow (1991 a,b) tidal resonance instability mechanism. In the first calculation, a disk evolves under steady mass transfer from $L_1$. In the second simulation, mass is added in Keplerian orbit to the inner disk. The two disks follow similar evolutionary paths. However the $L_1$ stream-disk interaction is found to slow the disk's radial expansion and to circularise gas orbits. The initial eccentricity growth in our simulations is exponential at a rate slightly less than predicted by Lubow (1991a). We do not observe a clearing of material from the resonance region via the disk's tidal response to the $m=2$ component of the binary potential as was described in Lubow (1992). Instead the $m=2$ response weakens as the disk eccentricty increases. Both disks reach an eccentric equilibrium state, in which they undergo prograde precession. The rate of viscous energy dissipation in the disks has a periodic excess with a period matching the disk's rotation. The source is identified as a large region in the outer disk, and the mechanism by which it is produced is identified. The time taken for the periodic excess to develop is consistent with the first appearance of superhumps in a superoutburst.

  3. Tidal Energy System for On-Shore Power Generation

    SciTech Connect (OSTI)

    Bruce, Allan J

    2012-06-26T23:59:59.000Z

    Addressing the urgent need to develop LCOE competitive renewable energy solutions for US energy security and to replace fossil-fuel generation with the associated benefits to environment impacts including a reduction in CO2 emissions, this Project focused on the advantages of using hydraulic energy transfer (HET) in large-scale Marine Hydrokinetic (MHK) systems for harvesting off-shore tidal energy in US waters. A recent DOE resource assessment, identifies water power resources have a potential to meet 15% of the US electric supply by 2030, with MHK technologies being a major component. The work covered a TRL-4 laboratory proof-in-concept demonstration plus modeling of a 15MW full scale system based on an approach patented by NASA-JPL, in which submerged high-ratio gearboxes and electrical generators in conventional MHK turbine systems are replaced by a submerged hydraulic radial pump coupled to on-shore hydraulic motors driving a generator. The advantages are; first, the mean-time-between-failure (MTBF), or maintenance, can be extended from approximately 1 to 5 years and second, the range of tidal flow speeds which can be efficiently harvested can be extended beyond that of a conventional submerged generator. The approach uses scalable, commercial-off-the-shelf (COTS) components, facilitating scale-up and commercialization. All the objectives of the Project have been successfully met (1) A TRL4 system was designed, constructed and tested. It simulates a tidal energy turbine, with a 2-m diameter blade in up to a 2.9 m/sec flow. The system consists of a drive motor assembly providing appropriate torque and RPM, attached to a radial piston pump. The pump circulates pressurized, environmentally-friendly, HEES hydraulic fluid in a closed loop to an axial piston motor which drives an electrical generator, with a resistive load. The performance of the components, subsystems and system were evaluated during simulated tidal cycles. The pump is contained in a tank for immersion testing. The COTS pump and motor were selected to scale to MW size and were oversized for the TRL-4 demonstration, operating at only 1-6% of rated values. Nevertheless, in for 2-18 kW drive power, in agreement with manufacturer performance data, we measured efficiencies of 85-90% and 75-80% for the pump and motor, respectively. These efficiencies being 95-96% at higher operating powers. (2) Two follow-on paths were identified. In both cases conventional turbine systems can be modified, replacing existing gear box and generator with a hydraulic pump and on-shore components. On a conventional path, a TRL5/6 15kW turbine system can be engineered and tested on a barge at an existing site in Maine. Alternatively, on an accelerated path, a TRL-8 100kW system can be engineered and tested by modifying a team member's existing MHK turbines, with barge and grid-connected test sites in-place. On both paths the work can be expedited and cost effective by reusing TRL-4 components, modifying existing turbines and using established test sites. (3) Sizing, performance modeling and costing of a scaled 15MW system, suitable for operation in Maine's Western Passage, was performed. COTS components are identified and the performance projections are favorable. The estimated LCOE is comparable to wind generation with peak production at high demand times. (4) We determined that a similar HET approach can be extended to on-shore and off-shore wind turbine systems. These are very large energy resources which can be addressed in parallel for even great National benefit. (5) Preliminary results on this project were presented at two International Conferences on renewable energy in 2012, providing a timely dissemination of information. We have thus demonstrated a proof-in-concept of a novel, tidal HET system that eliminates all submerged gears and electronics to improve reliability. Hydraulic pump efficiencies of 90% have been confirmed in simulated tidal flows between 1 and 3 m/s, and at only 1-6% of rated power. Total system efficiencies have also been modeled, up to MW-scale, for ti

  4. TIDAL DISSIPATION COMPARED TO SEISMIC DISSIPATION: IN SMALL BODIES, EARTHS, AND SUPER-EARTHS

    SciTech Connect (OSTI)

    Efroimsky, Michael, E-mail: michael.efroimsky@usno.navy.mil [U.S. Naval Observatory, Washington, DC 20392 (United States)

    2012-02-20T23:59:59.000Z

    While the seismic quality factor and phase lag are defined solely by the bulk properties of the mantle, their tidal counterparts are determined by both the bulk properties and the size effect (self-gravitation of a body as a whole). For a qualitative estimate, we model the body with a homogeneous sphere, and express the tidal phase lag through the lag in a sample of material. Although simplistic, our model is sufficient to understand that the lags are not identical. The difference emerges because self-gravitation pulls the tidal bulge down. At low frequencies, this reduces strain and the damping rate, making tidal damping less efficient in larger objects. At higher frequencies, competition between self-gravitation and rheology becomes more complex, though for sufficiently large super-Earths the same rule applies: the larger the planet, the weaker the tidal dissipation in it. Being negligible for small terrestrial planets and moons, the difference between the seismic and tidal lagging (and likewise between the seismic and tidal damping) becomes very considerable for large exoplanets (super-Earths). In those, it is much lower than what one might expect from using a seismic quality factor. The tidal damping rate deviates from the seismic damping rate, especially in the zero-frequency limit, and this difference takes place for bodies of any size. So the equal in magnitude but opposite in sign tidal torques, exerted on one another by the primary and the secondary, have their orbital averages going smoothly through zero as the secondary crosses the synchronous orbit. We describe the mantle rheology with the Andrade model, allowing it to lean toward the Maxwell model at the lowest frequencies. To implement this additional flexibility, we reformulate the Andrade model by endowing it with a free parameter {zeta} which is the ratio of the anelastic timescale to the viscoelastic Maxwell time of the mantle. Some uncertainty in this parameter's frequency dependence does not influence our principal conclusions.

  5. Wave represents displacement Wave represents pressure Source -Sound Waves

    E-Print Network [OSTI]

    Colorado at Boulder, University of

    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

  6. Ecology of Juvenile Salmonids in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta, Lower Columbia River, 2007 Annual Report.

    SciTech Connect (OSTI)

    Sobocinski, Kathryn; Johnson, Gary; Sather, Nichole [Pacific Northwest National Laboratory

    2008-03-17T23:59:59.000Z

    This document is the first annual report for the study titled 'Ecology of Juvenile Salmonids in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta in the Lower Columbia River'. Hereafter, we refer to this research as the Tidal Freshwater Monitoring (TFM) Study. The study is part of the research, monitoring, and evaluation effort developed by the Action Agencies (Bonneville Power Administration, U.S. Army Corps of Engineers, U.S. Bureau of Reclamation) in response to obligations arising from the Endangered Species Act as a result of operation of the Federal Columbia River Power System (FCRPS). The project is performed under the auspices of the Northwest Power and Conservation Council's Columbia Basin Fish and Wildlife Program. The goal of the 2007-2009 Tidal Freshwater Monitoring Study is to answer the following questions: In what types of habitats within the tidal freshwater area of the lower Columbia River and estuary (LCRE; Figure 1) are yearling and subyearling salmonids found, when are they present, and under what environmental conditions?1 And, what is the ecological importance2 of shallow (0-5 m) tidal freshwater habitats to the recovery of Upper Columbia River spring Chinook salmon and steelhead and Snake River fall Chinook salmon? Research in 2007 focused mainly on the first question, with fish stock identification data providing some indication of Chinook salmon presence at the variety of habitat types sampled. The objectives and sub-objectives for the 2007 study were as follows: (1) Habitat and Fish Community Characteristics-Provide basic data on habitat and fish community characteristics for yearling and subyearling salmonids at selected sites in the tidal freshwater reach in the vicinity of the Sandy River delta. (1a) Characterize vegetation assemblage percent cover, conventional water quality, substrate composition, and beach slope at each of six sampling sites in various tidal freshwater habitat types. (1b) Determine fish community characteristics, including species composition, abundance, and temporal and spatial distributions. (1c) Estimate the stock of origin for the yearling and subyearling Chinook salmon captured at the sampling sites using genetic analysis. (1d) Statistically assess the relationship between salmonid abundance and habitat parameters, including ancillary variables such as temperature and river stage. (2) Acoustic Telemetry Monitoring-Assess feasibility of applying Juvenile Salmon Acoustic Telemetry System (JSATS) technology to determine migration characteristics from upriver of Bonneville Dam through the study area (vicinity of the Sandy River delta/Washougal River confluence). (2a) Determine species composition, release locations, and distributions of JSATS-tagged fish. (2b) Estimate run timing, residence times, and migration pathways for these fish. Additionally, both objectives serve the purpose of baseline research for a potential tidal rechannelization project on the Sandy River. The U.S. Forest Service, in partnership with the Bonneville Power Administration and the U.S. Army Corps of Engineers, is currently pursuing reconnection of the east (relict) Sandy River channel with the current channel to improve fish and wildlife habitat in the Sandy River delta. Our study design and the location of sampling sites in this reach provide baseline data to evaluate the potential restoration.

  7. Multiscale heterogeneity characterization of tidal channel, tidal delta and foreshore facies, Almond Formation outcrops, Rock Springs uplift, Wyoming

    SciTech Connect (OSTI)

    Schatzinger, R.A.; Tomutsa, L. [BDM Petroleum Technologies, Bartlesville, OK (United States)

    1997-08-01T23:59:59.000Z

    In order to accurately predict fluid flow within a reservoir, variability in the rock properties at all scales relevant to the specific depositional environment needs to be taken into account. The present work describes rock variability at scales from hundreds of meters (facies level) to millimeters (laminae) based on outcrop studies of the Almond Formation. Tidal channel, tidal delta and foreshore facies were sampled on the eastern flank of the Rock Springs uplift, southeast of Rock Springs, Wyoming. The Almond Fm. was deposited as part of a mesotidal Upper Cretaceous transgressive systems tract within the greater Green River Basin. Bedding style, lithology, lateral extent of beds of bedsets, bed thickness, amount and distribution of depositional clay matrix, bioturbation and grain sorting provide controls on sandstone properties that may vary more than an order of magnitude within and between depositional facies in outcrops of the Almond Formation. These features can be mapped on the scale of an outcrop. The products of diagenesis such as the relative timing of carbonate cement, scale of cemented zones, continuity of cemented zones, selectively leached framework grains, lateral variability of compaction of sedimentary rock fragments, and the resultant pore structure play an equally important, although less predictable role in determining rock property heterogeneity. A knowledge of the spatial distribution of the products of diagenesis such as calcite cement or compaction is critical to modeling variation even within a single facies in the Almond Fin. because diagenesis can enhance or reduce primary (depositional) rock property heterogeneity. Application of outcrop heterogeneity models to the subsurface is greatly hindered by differences in diagenesis between the two settings. The measurements upon which this study is based were performed both on drilled outcrop plugs and on blocks.

  8. Professional paper A chronology of freaque wave encounters

    E-Print Network [OSTI]

    seafarers throughout the ages. After being ignored or dismissed for decades, freaque waves have now emerged of wave energy through time and space, through areas of variable surface ocean currents, and through

  9. Direct-current-like Phase Space Manipulation Using Chirped Alternating Current Fields

    SciTech Connect (OSTI)

    P.F. Schmit and N.J. Fisch

    2010-02-01T23:59:59.000Z

    Waves in plasmas can accelerate particles that are resonant with the wave. A dc electric field also accelerates particles, but without a resonance discrimination, which makes the acceleration mechanism profoundly different. Whereas wave-particle acceleration mechanisms have been widely discussed in the literature, this work discusses the direct analogy between wave acceleration and dc field acceleration in a particular parameter regime explored in previous works. Apart from the academic interest of this correspondence, there may be practical advantages in using waves to mimic dc electric fields, for example, in driving plasma current with high efficiency.

  10. 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

  11. Current Titles

    SciTech Connect (OSTI)

    Various

    2006-06-01T23:59:59.000Z

    This booklet is published for those interested in current research being conducted at the National Center for Electron Microscopy. The NCEM is a DOE-designated national user facility and is available at no charge to qualified researchers. Access is controlled by an external steering committee. Interested researchers may contact Jane Cavlina, Administrator, at 510/486-6036.

  12. Analytical Model of Tidal Distortion and Dissipation for a Giant Planet with a Viscoelastic Core

    E-Print Network [OSTI]

    Storch, Natalia I

    2015-01-01T23:59:59.000Z

    We present analytical expressions for the tidal Love numbers of a giant planet with a solid core and a fluid envelope. We model the core as a uniform, incompressible, elastic solid, and the envelope as a non-viscous fluid satisfying the $n=1$ polytropic equation of state. We discuss how the Love numbers depend on the size, density, and shear modulus of the core. We then model the core as a viscoelastic Maxwell solid and compute the tidal dissipation rate in the planet as characterized by the imaginary part of the Love number $k_2$. Our results improve upon existing calculations based on planetary models with a solid core and a uniform ($n=0$) envelope. Our analytical expressions for the Love numbers can be applied to study tidal distortion and viscoelastic dissipation of giant planets with solid cores of various rheological properties, and our general method can be extended to study tidal distortion/dissipation of super-earths.

  13. Division of Water, Parts 660-661: Tidal Wetlands (New York)

    Broader source: Energy.gov [DOE]

    These regulations require permits for any activity which directly or indirectly may have a significant adverse effect on the existing condition of any tidal wetland, including but not limited to...

  14. E-Print Network 3.0 - arterial-end tidal carbon Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    kWh range. Typical cost ranges include: Tidal generation - between 16 and 38pkWh Offshore wind - between 15... account of multiple factors for each generation type...

  15. Groundwater response to dual tidal fluctuations in a peninsula or an elongated island

    E-Print Network [OSTI]

    Zhan, Hongbin

    1 , Hongbin Zhan2,3, *, and Zhonghua Tang1 1 School of Environmental Studies, China University of the tidal fluctuations. This is called quasi-steady state condition *Correspondence to: Hongbin Zhan

  16. Wave forces on monotower structures fitted with icebreaking cones

    E-Print Network [OSTI]

    Harrington, Michael Gerard

    2012-06-07T23:59:59.000Z

    and theory presently used in the design of offshore tower structures. Presently, wave forces are predicted using a wave- structure interaction approach, diffraction theory, or some combination of the two. An alternative wave force theory was presented... of structures fitted with icebreaking cones. THEORETICAL DEVELOPMENT One of the major difficulties in analyzing the dynamic response of offshore structures is determining the wave-induced excitation forces. There are currently two methods of predicting wave...

  17. Vortices in Brain waves

    E-Print Network [OSTI]

    Freeman, Walter J III; Vitiello, Giuseppe

    2010-01-01T23:59:59.000Z

    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).

  18. A Modeling Study of the Potential Water Quality Impacts from In-Stream Tidal Energy Extraction

    SciTech Connect (OSTI)

    Wang, Taiping; Yang, Zhaoqing; Copping, Andrea E.

    2013-11-09T23:59:59.000Z

    To assess the effects of tidal energy extraction on water quality in a simplified estuarine system, which consists of a tidal bay connected to the coastal ocean through a narrow channel where energy is extracted using in-stream tidal turbines, a three-dimensional coastal ocean model with built-in tidal turbine and water quality modules was applied. The effects of tidal energy extraction on water quality were examined for two energy extraction scenarios as compared with the baseline condition. It was found, in general, that the environmental impacts associated with energy extraction depend highly on the amount of power extracted from the system. Model results indicate that, as a result of energy extraction from the channel, the competition between decreased flushing rates in the bay and increased vertical mixing in the channel directly affects water quality responses in the bay. The decreased flushing rates tend to cause a stronger but negative impact on water quality. On the other hand, the increase of vertical mixing could lead to higher bottom dissolved oxygen at times. As the first modeling effort directly aimed at examining the impacts of tidal energy extraction on estuarine water quality, this study demonstrates that numerical models can serve as a very useful tool for this purpose. However, more careful efforts are warranted to address system-specific environmental issues in real-world, complex estuarine systems.

  19. "Circularization" vs. Accretion -- What Powers Tidal Disruption Events?

    E-Print Network [OSTI]

    Piran, Tsvi; Krolik, Julian; Cheng, Roseanne M; Shiokawa, Hotaka

    2015-01-01T23:59:59.000Z

    A tidal disruption event (TDE) takes place when a star passes near enough to a massive black hole to be disrupted. About half the star's matter is given elliptical trajectories with large apocenter distances, the other half is unbound. To "circularize", i.e., to form an accretion flow, the bound matter must lose a significant amount of energy, with the actual amount depending on the characteristic scale of the flow measured in units of the black hole's gravitational radius (~ 10^{51} (R/1000R_g)^{-1} erg). Recent numerical simulations (Shiokawa et al., 2015) have revealed that the circularization scale is close to the scale of the most-bound initial orbits, ~ 10^3 M_{BH,6.5}^{-2/3} R_g ~ 10^{15} M_{BH,6.5}^{1/3} cm from the black hole, and the corresponding circularization energy dissipation rate is $\\sim 10^{44} M_{BH,6.5}^{-1/6}$~erg/s. We suggest that the energy liberated during circularization, rather then energy liberated by accretion onto the black hole, powers the observed optical TDE candidates (e.g.A...

  20. Internal tide generation by tall ocean ridges

    E-Print Network [OSTI]

    Echeverri Mondragón, Paula

    2009-01-01T23:59:59.000Z

    Internal tides are internal waves of tidal period generated by tidal currents flowing over submarine topography. Tall ridges that are nominally two-dimensional (2-D) are sites of particularly strong generation. The subsequent ...

  1. Current Contracts

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation InInformationCenterResearchCASLNanoporousTestimonyContact Us -SeparationsRelevantCurrent

  2. Possible new wave phenomena in the brain

    E-Print Network [OSTI]

    Jerzy Szwed

    2009-08-10T23:59:59.000Z

    We propose to search for new wave phenomena in the brain by using interference effects in analogy to the well-known double slit (Young) experiment. This method is able to extend the range of oscillation frequencies to much higher values than currently accessible. It is argued that such experiments may test the hypothesis of the wave nature of information coding.

  3. Deepwater Internal Wave Study and Application

    E-Print Network [OSTI]

    Jiang, Lei

    2013-12-10T23:59:59.000Z

    and ocean currents. Although their effects on floating drilling platforms and their riser systems have not been extensively studied, in the past these waves have seriously disrupted offshore exploration and drilling operations. In particular, a drill pipe...

  4. Modeling of In-stream Tidal Energy Development and its Potential Effects in Tacoma Narrows, Washington, USA

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Wang, Taiping; Copping, Andrea E.; Geerlofs, Simon H.

    2014-10-01T23:59:59.000Z

    Understanding and providing proactive information on the potential for tidal energy projects to cause changes to the physical system and to key water quality constituents in tidal waters is a necessary and cost-effective means to avoid costly regulatory involvement and late stage surprises in the permitting process. This paper presents a modeling study for evaluating the tidal energy extraction and its potential impacts on the marine environment in a real world site - Tacoma Narrows of Puget Sound, Washington State, USA. An unstructured-grid coastal ocean model, fitted with a module that simulates tidal energy devices, was applied to simulate the tidal energy extracted by different turbine array configurations and the potential effects of the extraction at local and system-wide scales in Tacoma Narrows and South Puget Sound. Model results demonstrated the advantage of an unstructured-grid model for simulating the far-field effects of tidal energy extraction in a large model domain, as well as assessing the near-field effect using a fine grid resolution near the tidal turbines. The outcome shows that a realistic near-term deployment scenario extracts a very small fraction of the total tidal energy in the system and that system wide environmental effects are not likely; however, near-field effects on the flow field and bed shear stress in the area of tidal turbine farm are more likely. Model results also indicate that from a practical standpoint, hydrodynamic or water quality effects are not likely to be the limiting factor for development of large commercial-scale tidal farms. Results indicate that very high numbers of turbines are required to significantly alter the tidal system; limitations on marine space or other environmental concerns are likely to be reached before reaching these deployment levels. These findings show that important information obtained from numerical modeling can be used to inform regulatory and policy processes for tidal energy development.

  5. Coda wave interferometry 1 Coda wave interferometry

    E-Print Network [OSTI]

    Snieder, Roel

    Coda wave interferometry 1 Coda wave interferometry An interferometer is an instrument that is sensitive to the interference of two or more waves (optical or acoustic). For example, an optical interferometer uses two interfering light beams to measure small length changes. Coda wave interferometry

  6. On the circulation and tidal flushing of Mobile Bay, Alabama

    E-Print Network [OSTI]

    Austin, George Belden

    1953-01-01T23:59:59.000Z

    . Temperature-Salinity Data (Mobile River) . . . . . . . . . . . ~ . . 56 III. Current and Wind Data 57 Current and Wind Data (continued) Current and Wind Data (continued) IV, Mobile River-Bay Volume Segments 59 V. Mobile River-Bay Cumulative Volume... wind velocities from the South and Nest), a "norther" blew in on the 28th of October bringing lower temperatures and strong northeast winds. This situation lasted for two days, and the effects on the water movements in the bay are rather clearly...

  7. Holographic p-wave Josephson junction

    E-Print Network [OSTI]

    Wang, Yong-Qiang; Zhao, Zhen-Hua

    2011-01-01T23:59:59.000Z

    In this work we generalized holographic model for s-wave DC Josephson junction constructed in arXiv:1101.3326[hep-th] to a holographic description for p-wave Josephson junction. By solving numerically the coupled equations of motion of Yang-Mills theory for a non-Abelian SU(2) gauge fields in (3+1)-dimensional AdS spacetimes, we shown that DC current of the p-wave Josephson junction is proportional to the sine of the phase difference across the junction like the s-wave case.

  8. Holographic p-wave Josephson junction

    E-Print Network [OSTI]

    Yong-Qiang Wang; Yu-Xiao Liu; Zhen-Hua Zhao

    2011-09-20T23:59:59.000Z

    In this work we generalized holographic model for s-wave DC Josephson junction constructed in arXiv:1101.3326[hep-th] to a holographic description for p-wave Josephson junction. By solving numerically the coupled equations of motion of Yang-Mills theory for a non-Abelian SU(2) gauge fields in (3+1)-dimensional AdS spacetimes, we shown that DC current of the p-wave Josephson junction is proportional to the sine of the phase difference across the junction like the s-wave case.

  9. Shrinking binary and planetary orbits by Kozai cycles with tidal friction

    E-Print Network [OSTI]

    Daniel Fabrycky; Scott Tremaine

    2007-05-30T23:59:59.000Z

    At least two arguments suggest that the orbits of a large fraction of binary stars and extrasolar planets shrank by 1-2 orders of magnitude after formation: (i) the physical radius of a star shrinks by a large factor from birth to the main sequence, yet many main-sequence stars have companions orbiting only a few stellar radii away, and (ii) in current theories of planet formation, the region within ~0.1 AU of a protostar is too hot and rarefied for a Jupiter-mass planet to form, yet many "hot Jupiters" are observed at such distances. We investigate orbital shrinkage by the combined effects of secular perturbations from a distant companion star (Kozai oscillations) and tidal friction. We integrate the relevant equations of motion to predict the distribution of orbital elements produced by this process. Binary stars with orbital periods of 0.1 to 10 days, with a median of ~2 d, are produced from binaries with much longer periods (10 d to 10^5 d), consistent with observations indicating that most or all short-period binaries have distant companions (tertiaries). We also make two new testable predictions: (1) For periods between 3 and 10 d, the distribution of the mutual inclination between the inner binary and the tertiary orbit should peak strongly near 40 deg and 140 deg. (2) Extrasolar planets whose host stars have a distant binary companion may also undergo this process, in which case the orbit of the resulting hot Jupiter will typically be misaligned with the equator of its host star.

  10. General Relativistic Hydrodynamic Simulation of Accretion Flow from a Stellar Tidal Disruption

    E-Print Network [OSTI]

    Shiokawa, Hotaka; Cheng, Roseanne M; Piran, Tsvi; Noble, Scott C

    2015-01-01T23:59:59.000Z

    We study how the matter dispersed when a supermassive black hole tidally disrupts a star joins an accretion flow. Combining a relativistic hydrodynamic simulation of the stellar disruption with a relativistic hydrodynamics simulation of the tidal debris motion, we track such a system until ~80% of the stellar mass bound to the black hole has settled into an accretion flow. Shocks near the stellar pericenter and also near the apocenter of the most tightly-bound debris dissipate orbital energy, but only enough to make the characteristic radius comparable to the semi-major axis of the most-bound material, not the tidal radius as previously thought. The outer shocks are caused by post-Newtonian effects, both on the stellar orbit during its disruption and on the tidal forces. Accumulation of mass into the accretion flow is non-monotonic and slow, requiring ~3--10x the orbital period of the most tightly-bound tidal streams, while the inflow time for most of the mass may be comparable to or longer than the mass accu...

  11. Wave Heating of the Solar Atmosphere

    E-Print Network [OSTI]

    Arregui, I

    2015-01-01T23:59:59.000Z

    Magnetic waves are a relevant component in the dynamics of the solar atmosphere. Their significance has increased because of their potential as a remote diagnostic tool and their presumed contribution to plasma heating processes. We discuss our current understanding on coronal heating by magnetic waves, based on recent observational evidence and theoretical advances. The discussion starts with a selection of observational discoveries that have brought magnetic waves to the forefront of the coronal heating discussion. Then, our theoretical understanding on the nature and properties of the observed waves and the physical processes that have been proposed to explain observations are described. Particular attention is given to the sequence of processes that link observed wave characteristics with concealed energy transport, dissipation, and heat conversion. We conclude with a commentary on how the combination of theory and observations should help us understanding and quantifying magnetic wave heating of the sola...

  12. MHD Wave Propagation in the Neighbourhood of Two Null Points

    E-Print Network [OSTI]

    J. A. McLaughlin; A. W. Hood

    2007-12-11T23:59:59.000Z

    The nature of fast magnetoacoustic and Alfv\\'en waves is investigated in a zero $\\beta$ plasma in the neighbourhood of a pair of two-dimensional null points. This gives an indication of wave propagation in the low $\\beta$ solar corona, for a more complicated magnetic configuration than that looked at by McLaughlin & Hood (2004). It is found that the fast wave is attracted to the null points and that the front of the wave slows down as it approaches the null point pair, with the wave splitting and part of the wave accumulating at one null and the rest at the other. Current density will then accumulate at these points and ohmic dissipation will then extract the energy in the wave at these points. This suggests locations where wave heating will occur in the corona. The Alfv\\'en wave behaves in a different manner in that the wave accumulates along the separatrices. Hence, the current density will accumulate at this part of the topology and this is where wave heating will occur. However, the phenomenon of wave accumulation at a specific place is a feature of both wave types, and illustrates the importance of studying the topology of the corona when considering MHD wave propagation.

  13. Plane waves Lumped systems

    E-Print Network [OSTI]

    Berlin,Technische Universität

    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

  14. A model-dye comparison experiment in the tidal mixing front zone on the southern flank of Georges Bank

    E-Print Network [OSTI]

    Chen, Changsheng

    A model-dye comparison experiment in the tidal mixing front zone on the southern flank of Georges; revised 8 June 2007; accepted 30 October 2007; published 9 February 2008. [1] A process-oriented model-dye the observed movement of dye across the tidal mixing front on the southern flank of Georges Bank during 22

  15. Puget Sound Tidal Energy In-Water Testing and Development Project Final Technical Report

    SciTech Connect (OSTI)

    Craig W. Collar

    2012-11-16T23:59:59.000Z

    Tidal energy represents potential for the generation of renewable, emission free, environmentally benign, and cost effective energy from tidal flows. A successful tidal energy demonstration project in Puget Sound, Washington may enable significant commercial development resulting in important benefits for the northwest region and the nation. This project promoted the United States Department of Energy�s Wind and Hydropower Technologies Program�s goals of advancing the commercial viability, cost-competitiveness, and market acceptance of marine hydrokinetic systems. The objective of the Puget Sound Tidal Energy Demonstration Project is to conduct in-water testing and evaluation of tidal energy technology as a first step toward potential construction of a commercial-scale tidal energy power plant. The specific goal of the project phase covered by this award was to conduct all activities necessary to complete engineering design and obtain construction approvals for a pilot demonstration plant in the Admiralty Inlet region of the Puget Sound. Public Utility District No. 1 of Snohomish County (The District) accomplished the objectives of this award through four tasks: Detailed Admiralty Inlet Site Studies, Plant Design and Construction Planning, Environmental and Regulatory Activities, and Management and Reporting. Pre-Installation studies completed under this award provided invaluable data used for site selection, environmental evaluation and permitting, plant design, and construction planning. However, these data gathering efforts are not only important to the Admiralty Inlet pilot project. Lessons learned, in particular environmental data gathering methods, can be applied to future tidal energy projects in the United States and other parts of the world. The District collaborated extensively with project stakeholders to complete the tasks for this award. This included Federal, State, and local government agencies, tribal governments, environmental groups, and others. All required permit and license applications were completed and submitted under this award, including a Final License Application for a pilot hydrokinetic license from the Federal Energy Regulatory Commission. The tasks described above have brought the project through all necessary requirements to construct a tidal pilot project in Admiralty Inlet with the exception of final permit and license approvals, and the selection of a general contractor to perform project construction.

  16. Tidal hydraulics of San Luis Pass, Texas: a field and numerical investigation

    E-Print Network [OSTI]

    Morton, Scott Jerome

    1980-01-01T23:59:59.000Z

    TIDAL HYDPAULICS OF SAN LUIS PASS, TEXAS: A FIELD AND VBKRICAL INSTIGATION A Thesis by SCOTT JEROME MORTON Submitted to the Graduate College of Texas A(II University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE August 1980 i&Iajor Subject: Ocean Engineering TIDAL HyDRAULICS OF SAN LUIS PASS, TEXAS: A FIELD AND M&IERICAL INVESTIGATION A Thesis by SCOTI' JEROIIE MORTON Approved as to style and content by: (C?airman of Committee) (Member) /member...

  17. Accessibility for lower hybrid waves in PBX-M

    SciTech Connect (OSTI)

    Takahashi, H.; Bell, R.; Bernabei, S.; Chance, M.; Chu, T.K.; Gettelfinger, G.; Greenough, N.; Hatcher, R.; Ignat, D.; Jardin, S.; Kaita, R.; Kaye, S.; Kugel, H.; LeBlanc, B.; Manickam, J.; Okabayashi, M.; Ono, M.; Paul, S.; Perkins, F.; Sauthoff, N.; Sesnic, S.; Sun, Y.; Tighe, W.; Valeo, E.; von Goeler, S. (Princeton Univ., NJ (United States). Plasma Physics Lab.); Batha, S.; Levinton, F. (Fusion Physics and Technology

    1993-07-01T23:59:59.000Z

    Understanding the wave damping mechanism in the presence of a spectral gap' is an important issue for the current profile control using Lower Hybrid Current Drive (LHCD). The authors examine a traditional explanation based upon upshifting of the wave parallel refractive index (n[sub [parallel

  18. MHK Projects/Orient Point Tidal | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAKGalway Bay IE < MHK Projects JumpInformationWave

  19. Smooth sandwich gravitational waves

    E-Print Network [OSTI]

    J. Podolsky

    1998-07-16T23:59:59.000Z

    Gravitational waves which are smooth and contain two asymptotically flat regions are constructed from the homogeneous pp-waves vacuum solution. Motion of free test particles is calculated explicitly and the limit to an impulsive wave is also considered.

  20. Gravitational waves from gravitational collapse

    SciTech Connect (OSTI)

    Fryer, Christopher L [Los Alamos National Laboratory; New, Kimberly C [Los Alamos National Laboratory

    2008-01-01T23:59:59.000Z

    Gravitational wave emission from stellar collapse has been studied for nearly four decades. Current state-of-the-art numerical investigations of collapse include those that use progenitors with more realistic angular momentum profiles, properly treat microphysics issues, account for general relativity, and examine non-axisymmetric effects in three dimensions. Such simulations predict that gravitational waves from various phenomena associated with gravitational collapse could be detectable with ground-based and space-based interferometric observatories. This review covers the entire range of stellar collapse sources of gravitational waves: from the accretion induced collapse of a white dwarf through the collapse down to neutron stars or black holes of massive stars to the collapse of supermassive stars.

  1. A numerical study of horizontal dispersion in a macro tidal basin

    E-Print Network [OSTI]

    Maine, University of

    in Cobscook Bay, a macro tidal basin, is simulated using the three-dimensional, nonlinear, finite element regimes in different parts of Cobscook Bay. It is found that the effective Lagrangian dispersion ocean model, QUODDY_dry. Numerical particles are released from various transects in the bay at different

  2. Numerical study of the diapycnal flow through a tidal front with passive tracers

    E-Print Network [OSTI]

    Dong, Changming "Charles"

    . This qualitatively agrees with a recent field experiment using a dye tracer on Georges Bank. Additional experiments are performed to investigate the sensitivity of the tracer dispersion to the tidal phase and the location, the previous studies indicated Eulerian cross-front mean circu- lation maybe is in a multiple-cell structure

  3. Role of ocean heat transport in climates of tidally locked exoplanets around M dwarf stars

    E-Print Network [OSTI]

    Hu, Yongyun

    stellar radiation, ocean heat transport can even lead to complete deglaciation of the nightside. OurRole of ocean heat transport in climates of tidally locked exoplanets around M dwarf stars Yongyun Hu1 and Jun Yang Laboratory for Climate and Atmosphere­Ocean Studies, Department of Atmospheric

  4. PHYSIOLOGICAL PERFORMANCE OF INTERTIDAL CORALLINE ALGAE DURING A SIMULATED TIDAL CYCLE1

    E-Print Network [OSTI]

    Martone, Patrick T.

    PHYSIOLOGICAL PERFORMANCE OF INTERTIDAL CORALLINE ALGAE DURING A SIMULATED TIDAL CYCLE1 Rebecca J, Lobban and Harrison 1997, Helmuth and Hofmann 2001). During high tide, intertidal algae are underwater algae may be emerged and exposed to increased light stress, elevated air tem- peratures, and increased

  5. Tidal Interactions and Disruptions of Giant Planets on Highly Eccentric Orbits

    E-Print Network [OSTI]

    Joshua A. Faber; Frederic A. Rasio; Bart Willems

    2004-11-15T23:59:59.000Z

    We calculate the evolution of planets undergoing a strong tidal encounter using smoothed particle hydrodynamics (SPH), for a range of periastron separations. We find that outside the Roche limit, the evolution of the planet is well-described by the standard model of linear, non-radial, adiabatic oscillations. If the planet passes within the Roche limit at periastron, however, mass can be stripped from it, but in no case do we find enough energy transferred to the planet to lead to complete disruption. In light of the three new extrasolar planets discovered with periods shorter than two days, we argue that the shortest-period cases observed in the period-mass relation may be explained by a model whereby planets undergo strong tidal encounters with stars, after either being scattered by dynamical interactions into highly eccentric orbits, or tidally captured from nearly parabolic orbits. Although this scenario does provide a natural explanation for the edge found for planets at twice the Roche limit, it does not explain how such planets will survive the inevitable expansion that results from energy injection during tidal circularization.

  6. Gravity and tectonic patterns of Mercury: Effect of tidal deformation, spin-orbit resonance, nonzero

    E-Print Network [OSTI]

    Nimmo, Francis

    Gravity and tectonic patterns of Mercury: Effect of tidal deformation, spin-orbit resonance of spin-orbit resonance, nonzero eccentricity, despinning, and reorientation on Mercury's gravity and tectonic pattern. Large variations of the gravity and shape coefficients from the synchronous rotation

  7. Covariation of coastal water temperature and microbial pollution at interannual to tidal periods

    E-Print Network [OSTI]

    Winant, Clinton D.

    Covariation of coastal water temperature and microbial pollution at interannual to tidal periods, California, USA Daniel B. Lluch-Cota Centro de Investigaciones Biologicas del Noroeste, La Paz, Mexico-period cooling are coincident with elevated levels of microbial pollution in the surf zone. This relationship can

  8. Nitrogen Cycling and Ecosystem Exchanges in a Virginia Tidal Freshwater Marsh

    E-Print Network [OSTI]

    Neubauer, Scott C.

    loading due to watershed development and urbanization. We present a process-based mass balance model of N habitats for juvenile fishes, and buffering storm and flood waters (Odum et al. 1984; Mitsch and Gosselink dominated tidal freshwater marsh in the York River estuary, Virginia. The model, which was based

  9. Final Report for Sea-level Rise Response Modeling for San Francisco Bay Estuary Tidal

    E-Print Network [OSTI]

    Fleskes, Joe

    i Final Report for Sea-level Rise Response Modeling for San Francisco Bay Estuary Tidal Marshes Refuge in northern San Francisco Bay, California. #12;iii Final Report for Sea-level Rise Response)................................................................... 7 Sea-level rise scenario model inputs

  10. A CLASS OF ECCENTRIC BINARIES WITH DYNAMIC TIDAL DISTORTIONS DISCOVERED WITH KEPLER

    SciTech Connect (OSTI)

    Thompson, Susan E.; Barclay, Thomas; Howell, Steve B.; Still, Martin; Ibrahim, Khadeejah A. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Everett, Mark [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Mullally, Fergal; Rowe, Jason; Christiansen, Jessie L.; Twicken, Joseph D.; Clarke, Bruce D. [SETI Institute, 189 Bernardo Avenue, Suite 100, Mountain View, CA 94043 (United States); Kurtz, Donald W.; Hambleton, Kelly, E-mail: susan.e.thompson@nasa.gov [Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE (United Kingdom)

    2012-07-01T23:59:59.000Z

    We have discovered a class of eccentric binary systems within the Kepler data archive that have dynamic tidal distortions and tidally induced pulsations. Each has a uniquely shaped light curve that is characterized by periodic brightening or variability at timescales of 4-20 days, frequently accompanied by shorter period oscillations. We can explain the dominant features of the entire class with orbitally varying tidal forces that occur in close, eccentric binary systems. The large variety of light curve shapes arises from viewing systems at different angles. This hypothesis is supported by spectroscopic radial velocity measurements for five systems, each showing evidence of being in an eccentric binary system. Prior to the discovery of these 17 new systems, only four stars, where KOI-54 is the best example, were known to have evidence of these dynamic tides and tidally induced oscillations. We perform preliminary fits to the light curves and radial velocity data, present the overall properties of this class, and discuss the work required to accurately model these systems.

  11. Dissolved oxygen stratification in two micro-tidal partially-mixed estuaries

    E-Print Network [OSTI]

    Mallin, Michael

    Dissolved oxygen stratification in two micro-tidal partially-mixed estuaries Jing Lin a,*, Lian Xie online 21 August 2006 Abstract The controlling physical factors for vertical oxygen stratification that vertical stratification of dissolved oxygen (DO) concentration can be explained by the extended Hansen

  12. Asymmetry of Columbia River tidal plume fronts David A. Jay a,

    E-Print Network [OSTI]

    Hickey, Barbara

    or northern side and mark a transition from supercritical to subcritical flow for up to 12 h after high water plume water mass. This vorticitycontrols the transition of the tidal plume front to a subcritical state plume may overlie newly upwelled waters, these fronts can mix nutrients into the plume. Symmetry would

  13. Hydrodynamic Modeling, Optimization and Performance Assessment for Ducted and Non-ducted Tidal Turbines

    E-Print Network [OSTI]

    Victoria, University of

    Turbines by Michael Robert Shives B.Eng., Carleton University, 2008 A Thesis Submitted in Partial Hydrodynamic Modeling, Optimization and Performance Assessment for Ducted and Non-ducted Tidal Turbines examines methods for designing and analyzing kinetic turbines based on blade element momentum (BEM) theory

  14. Hydrodynamic Modeling, Optimization and Performance Assessment for Ducted and Non-ducted Tidal Turbines

    E-Print Network [OSTI]

    Pedersen, Tom

    Turbines by Michael Robert Shives B.Eng., Carleton University, 2008 A Dissertation Submitted in Partial Hydrodynamic Modeling, Optimization and Performance Assessment for Ducted and Non-ducted Tidal Turbines) #12;iii ABSTRACT This thesis examines methods for designing and analyzing kinetic turbines based

  15. An analytical solution of groundwater response to tidal fluctuation in a leaky confined aquifer

    E-Print Network [OSTI]

    Jiao, Jiu Jimmy

    of China. 1. Introduction In most coastal areas, groundwater and seawater are in con- stant communicationAn analytical solution of groundwater response to tidal fluctuation in a leaky confined aquifer Jiu of the solution presented in this paper. This solution is based on a conceptual model under the assumption

  16. Tidal mixing around the Maritime continent: implications for1 paleoclimate simulations2

    E-Print Network [OSTI]

    of mechanical energy for the ocean circulation and as such is 6 being incorporated changes in the ocean thermal structure, including 12 a ~1o C warming into state-of-the-art climate models. Calculation of the tidal energy flux depends on 7

  17. Assessing Soil and Hydrologic Properties for the Successful Creation of Non-Tidal Wetlands

    E-Print Network [OSTI]

    Darby, Dennis

    1 Assessing Soil and Hydrologic Properties for the Successful Creation of Non-Tidal Wetlands W. Lee, VA 23529-0276 rwhittec@odu.edu Introduction Federal and state wetlands protection regulations require the mitigation of impacts to jurisdictional wetlands via avoidance and minimization of damage whenever possible

  18. Inventory and Ventilation Efficiency of Nonnative and Native Phragmites australis (Common Reed) in Tidal

    E-Print Network [OSTI]

    NOTE Inventory and Ventilation Efficiency of Nonnative and Native Phragmites australis (Common Reed: 3 July 2012 # Coastal and Estuarine Research Federation 2012 Abstract Nonnative Phragmites is among the most in- vasive plants in the U.S. Atlantic coast tidal wetlands, whereas the native Phragmites has

  19. Wave Energy Machine Louise Butler, Bilal Demir, Caleb Lee, Joe Meiners, Christian Rodin

    E-Print Network [OSTI]

    Provancher, William

    Wave Energy Machine Louise Butler, Bilal Demir, Caleb Lee, Joe Meiners, Christian Rodin Advisor: Dr. Introduction Design Kinematic Model Testing Current wave energy technology harvests the vertical motion. Project Statement: Design a wave energy machine that harnesses underwater wave motion and converts

  20. Energy current imaging method for time reversal in elastic media

    SciTech Connect (OSTI)

    Anderson, Brian E [Los Alamos National Laboratory; Ulrich, Timothy J [Los Alamos National Laboratory; Le Bas, Pierre - Yves A [Los Alamos National Laboratory; Larmat, Carene [Los Alamos National Laboratory; Johnson, Paul A [Los Alamos National Laboratory; Guyer, Robert A [UNR; Griffa, Michele [ETH ZURICH

    2009-01-01T23:59:59.000Z

    An energy current imaging method is presented for use in locating sources of wave energy during the back propagation stage of the time reversal process. During the back propagation phase of an ideal time reversal experiment, wave energy coalesces from all angles of incidence to recreate the source event; after the recreation, wave energy diverges in every direction. An energy current imaging method based on this convergence/divergence behavior has been developed. The energy current imaging method yields a smaller spatial distribution for source reconstruction than is possible with traditional energy imaging methods.

  1. Environmental impact assessment and process simulation of the tidal current energy resource in the Strait of Messina 

    E-Print Network [OSTI]

    El-Geziry, Tarek Mohamed Ahmed

    2010-01-01T23:59:59.000Z

    Interest in exploring renewable energy resources has increased globally, especially with recent worldwide intentions to maintain the global climate. Looking at the oceans as a vast sustainable clean energy resource to ...

  2. Water Waves Roger Grimshaw

    E-Print Network [OSTI]

    ,2) provide a kinematic description of water waves, which to this point means that the conditionsWater Waves Roger Grimshaw May 7, 2003 Abstract A short review of the theory of weakly nonlinear water waves, prepared for the forthcoming Encyclopedia of Nonlinear Science 1 Introduction Water waves

  3. Pool spacing, channel morphology, and the restoration of tidal forested wetlands of the Columbia River, U.S.A.

    SciTech Connect (OSTI)

    Diefenderfer, Heida L.; Montgomery, David R.

    2008-10-09T23:59:59.000Z

    Tidal forested wetlands have sustained substantial areal losses, and restoration practitioners lack a description of many ecosystem structures associated with these late-successional systems in which surface water is a significant controlling factor on the flora and fauna. The roles of large woody debris in terrestrial and riverine ecosystems have been well described compared to functions in tidal areas. This study documents the role of large wood in forcing channel morphology in Picea-sitchensis (Sitka spruce) dominated freshwater tidal wetlands in the floodplain of the Columbia River, U.S.A. near the Pacific coast. The average pool spacing documented in channel surveys of three freshwater tidal forested wetlands near Grays Bay were 2.2 ± 1.3, 2.3 ± 1.2, and 2.5 ± 1.5. There were significantly greater numbers of pools on tidal forested wetland channels than on a nearby restoration site. On the basis of pool spacing and the observed sequences of log jams and pools, the tidal forested wetland channels were classified consistent with a forced step-pool class. Tidal systems, with bidirectional flow, have not previously been classified in this way. The classification provides a useful basis for restoration project design and planning in historically forested tidal freshwater areas, particularly in regard to the use of large wood in restoration actions and the development of pool habitats for aquatic species. Significant modifications by beaver on these sites warrant further investigation to explore the interactions between these animals and restoration actions affecting hydraulics and channel structure in tidal areas.

  4. Electromagnetic waves with nonlinear dispersion law

    E-Print Network [OSTI]

    Pavel Mednis

    2012-02-08T23:59:59.000Z

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

  5. Experimental Observation of Simultaneous Wave and Particle Behaviors in a Narrowband Single Photon's Wave Packe

    E-Print Network [OSTI]

    H. Yan; K. Liao; Z. Deng; J. He; Z. Y. Xue; Z. M. Zhang; S. L. Zhu

    2014-12-04T23:59:59.000Z

    Light's wave-particle duality is at the heart of quantum mechanics and can be well illustrated by Wheeler's delayed-choice experiment. The choice of inserting or removing the second classical (quantum) beam splitter in a Mach-Zehnder interferometer determines the classical (quantum) wave-particle behaviors of a photon. In this paper, we report our experiment using the classical beam splitter to observe the simultaneous wave-particle behaviors in the wave-packet of a narrowband single photon. This observation suggests that it is necessary to generalize the current quantum wave-particle duality theory. Our experiment demonstrates that the produced wave-particle state can be considered an additional degree of freedom and can be utilized in encoding quantum information.

  6. NREL Uses Computing Power to Investigate Tidal Power (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-10-01T23:59:59.000Z

    Until now, wind turbine controls that reduce the impacts of wind gusts and turbulence were always reactive - responding to the wind rather than anticipating it. But with today's laser-based sensors that measure wind speed ahead of the turbine, researchers at the National Renewable Energy Laboratory (NREL) and their industry partners are developing more intelligent controls. The world's first field tests of these controls are currently underway at the National Wind Technology Center (NWTC) at NREL, with plans for future commercialization.

  7. Large-amplitude circularly polarized electromagnetic waves in magnetized plasma

    SciTech Connect (OSTI)

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

    2014-05-15T23:59:59.000Z

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

  8. PROPAGATING WAVES ALONG SPICULES

    SciTech Connect (OSTI)

    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

    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.

  9. the wave model A traveling wave is an organized disturbance

    E-Print Network [OSTI]

    Winokur, Michael

    1 waves the wave model A traveling wave is an organized disturbance propagating at a well-defined wave speed v. · In transverse waves the particles of the medium move perpendicular to the direction of wave propagation. · In longitudinal waves the particles of the medium move parallel to the direction

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

    E-Print Network [OSTI]

    Pascal, Remy Claude Rene

    2012-11-29T23:59:59.000Z

    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 ...

  11. Gravity Waves on Hot Extrasolar Planets: I. Propagation and Interaction with the Background

    E-Print Network [OSTI]

    Watkins, Chris

    2010-01-01T23:59:59.000Z

    We study the effects of gravity waves, or g-modes, on hot extrasolar planets. These planets are expected to possess stably-stratified atmospheres, which support gravity waves. In this paper, we review the derivation of the equation that governs the linear dynamics of gravity waves and describe its application to a hot extrasolar planet, using HD209458 b as a generic example. We find that gravity waves can exhibit a wide range of behaviors, even for a single atmospheric profile. The waves can significantly accelerate or decelerate the background mean flow, depending on the difference between the wave phase and mean flow speeds. In addition, the waves can provide significant heating (~100 to ~1000 K per planetary rotation), especially to the region of the atmosphere above about 10 scale heights from the excitation region. Furthermore, by propagating horizontally, gravity waves provide a mechanism for transporting momentum and heat from the dayside of a tidally locked planet to its nightside. We discuss work tha...

  12. Magnetohydrodynamics wave propagation in the neighbourhood of two dipoles

    E-Print Network [OSTI]

    J. A. McLaughlin; A. W. Hood

    2007-12-11T23:59:59.000Z

    This paper is the third in a series of investigations by the authors. The nature of fast magnetoacoustic and Alfv\\'en waves is investigated in a 2D $\\beta=0$ plasma in the neighbourhood of two dipoles. We use both numerical simulations (two-step Lax-Wendroff scheme) and analytical techniques (WKB approximation). It is found that the propagation of the linear fast wave is dictated by the Alfv\\'en speed profile and that close to the null, the wave is attracted to the neutral point. However, it is also found that in this magnetic configuration some of the wave can escape the refraction effect; this had not been seen in previous investigations by the authors. The wave split occurs near the regions of very high Alfv\\'en speed (found near the loci of the two dipoles). Also, for the set-up investigated it was found that 40% of the wave energy accumulates at the null. Ohmic dissipation will then extract the wave energy at this point. The Alfv\\'en wave behaves in a different manner in that part of the wave accumulates along the separatrices and part escapes. Hence, the current density will accumulate at this part of the topology and this is where wave heating will occur. The phenomenon of wave accumulation at a specific place is a feature of both wave types, as is the result that a fraction of the wave can now escape the numerical box when propagating in this magnetic configuration.

  13. Photon wave function

    E-Print Network [OSTI]

    Iwo Bialynicki-Birula

    2005-08-26T23:59:59.000Z

    Photon wave function is a controversial concept. Controversies stem from the fact that photon wave functions can not have all the properties of the Schroedinger wave functions of nonrelativistic wave mechanics. Insistence on those properties that, owing to peculiarities of photon dynamics, cannot be rendered, led some physicists to the extreme opinion that the photon wave function does not exist. I reject such a fundamentalist point of view in favor of a more pragmatic approach. In my view, the photon wave function exists as long as it can be precisely defined and made useful.

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

    SciTech Connect (OSTI)

    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

    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.

  15. MHK Projects/Humboldt County Wave Project | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy Resources Jump to:46 - 429Lacey,(MonasterLowell Point, Alaska:LuzClick here Current /Tidal ProjectCA

  16. Substructure and Tidal Debris in Local Galaxies: Models and Observations

    E-Print Network [OSTI]

    James E. Taylor

    2004-11-18T23:59:59.000Z

    One of the generic predictions of modern cosmological models is that large galaxies should have experienced many mergers with smaller galaxies at some point in their past. Debris from such encounters will leave spatially distinct substructure in the stellar haloes of nearby galaxies, detectable for a few orbital periods after the final merger. In the case of the Milky Way, kinematic data from surveys such as RAVE and satellite missions such as GAIA will allow us to probe much more of the merger history, and to connect the properties of the stellar halo with those of local dwarf galaxies. To estimate what these programmes may discover, we review current observations of minor mergers in nearby galaxies, and compare these with predictions from a semi-analytic model of galaxy formation.

  17. Rogue Wave Modes for the Long Wave-Short Wave Resonance Kwok Wing CHOW*(1)

    E-Print Network [OSTI]

    1 Rogue Wave Modes for the Long Wave-Short Wave Resonance Model Kwok Wing CHOW*(1) , Hiu Ning CHAN.45.Yv; 47.35.Fg ABSTRACT The long wave-short wave resonance model arises physically when the phase velocity of a long wave matches the group velocity of a short wave. It is a system of nonlinear evolution

  18. EVOLUTION OF PLANETARY ORBITS WITH STELLAR MASS LOSS AND TIDAL DISSIPATION

    SciTech Connect (OSTI)

    Adams, Fred C. [Physics Department, University of Michigan, Ann Arbor, MI 48109 (United States)] [Physics Department, University of Michigan, Ann Arbor, MI 48109 (United States); Bloch, Anthony M. [Math Department, University of Michigan, Ann Arbor, MI 48109 (United States)] [Math Department, University of Michigan, Ann Arbor, MI 48109 (United States)

    2013-11-10T23:59:59.000Z

    Intermediate mass stars and stellar remnants often host planets, and these dynamical systems evolve because of mass loss and tides. This paper considers the combined action of stellar mass loss and tidal dissipation on planetary orbits in order to determine the conditions required for planetary survival. Stellar mass loss is included using a so-called Jeans model, described by a dimensionless mass loss rate ? and an index ?. We use an analogous prescription to model tidal effects, described here by a dimensionless dissipation rate ? and two indices (q, p). The initial conditions are determined by the starting value of angular momentum parameter ?{sub 0} (equivalently, the initial eccentricity) and the phase ? of the orbit. Within the context of this model, we derive an analytic formula for the critical dissipation rate ?, which marks the boundary between orbits that spiral outward due to stellar mass loss and those that spiral inward due to tidal dissipation. This analytic result ? = ?(?, ?, q, p, ?{sub 0}, ?) is essentially exact for initially circular orbits and holds to within an accuracy of ?50% over the entire multi-dimensional parameter space, where the individual parameters vary by several orders of magnitude. For stars that experience mass loss, the stellar radius often displays quasi-periodic variations, which produce corresponding variations in tidal forcing; we generalize the calculation to include such pulsations using a semi-analytic treatment that holds to the same accuracy as the non-pulsating case. These results can be used in many applications, e.g., to predict/constrain properties of planetary systems orbiting white dwarfs.

  19. Fast Wave Current Drive Modeling in Tokamaks John C. Wright

    E-Print Network [OSTI]

    Wright, John C.

    ; graduate student has been the company of my classmates. It is often the case that the best resource. Hans Herrmann (no relation to Mark), was my steady workout partner throughout the years as we logged

  20. Fast Wave Current Drive Modeling in Tokamaks John C. Wright

    E-Print Network [OSTI]

    Wright, John C.

    has been the company of my classmates. It is often the case that the best resource is not an article (no relation to Mark), was my steady workout partner throughout the years as we logged hundreds

  1. Ocean Wave Converters: State of the Art and Current Status

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    to 8x106 TWh/year, which is about 100 times the total hydroelectricity generation of the whole planet

  2. Observed Variability of Ocean Wave Stokes Drift, and the Eulerian Response to Passing Groups

    E-Print Network [OSTI]

    Smith, Jerome A.

    ­current interactions are also considered important in generating and maintaining Langmuir circulation (LC), a prominent 2005, in final form 13 September 2005) ABSTRACT Waves and currents interact via exchanges of mass with current theory. 1. Introduction Surface waves are of central importance in general to air­sea interactions

  3. Formation of Hot Planets by a combination of planet scattering, tidal circularization, and Kozai mechanism

    E-Print Network [OSTI]

    M. Nagasawa; S. Ida; T. Bessho

    2008-01-09T23:59:59.000Z

    We have investigated the formation of close-in extrasolar giant planets through a coupling effect of mutual scattering, Kozai mechanism, and tidal circularization, by orbital integrations. We have carried out orbital integrations of three planets with Jupiter-mass, directly including the effect of tidal circularization. We have found that in about 30% runs close-in planets are formed, which is much higher than suggested by previous studies. We have found that Kozai mechanism by outer planets is responsible for the formation of close-in planets. During the three-planet orbital crossing, the Kozai excitation is repeated and the eccentricity is often increased secularly to values close enough to unity for tidal circularization to transform the inner planet to a close-in planet. Since a moderate eccentricity can remain for the close-in planet, this mechanism may account for the observed close-in planets with moderate eccentricities and without nearby secondary planets. Since these planets also remain a broad range of orbital inclinations (even retrograde ones), the contribution of this process would be clarified by more observations of Rossiter-McLaughlin effects for transiting planets.

  4. New wave generation

    E-Print Network [OSTI]

    Mercier, Matthieu J.

    We present the results of a combined experimental and numerical study of the generation of internal waves using the novel internal wave generator design of Gostiaux et al. (Exp. Fluids, vol. 42, 2007, pp. 123–130). This ...

  5. Accessibility for lower hybrid waves in PBX-M

    SciTech Connect (OSTI)

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

    1993-07-01T23:59:59.000Z

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

  6. MHK Projects/Humboldt County WaveConnect | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy Resources Jump to:46 - 429Lacey,(MonasterLowell Point, Alaska:LuzClick here Current /Tidal

  7. IWA : an analysis program for isentropic wave measurements.

    SciTech Connect (OSTI)

    Ao, Tommy

    2009-02-01T23:59:59.000Z

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

  8. Performance Assessment of the Wave Dragon Wave Energy Converter

    E-Print Network [OSTI]

    Hansen, René Rydhof

    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

  9. Dust-Acoustic Waves: Visible Sound Waves Robert L. Merlino

    E-Print Network [OSTI]

    Merlino, Robert L.

    Dust-Acoustic Waves: Visible Sound Waves Robert L. Merlino Department of Physics and Astronomy with their announcement that: "We find that a new type of sound wave, namely, the dust-acoustic waves, can appear" [1 and experimental work on dust acoustic waves is given. The basic physics of the dust acoustic wave and some

  10. System and method for generating current by selective electron heating

    DOE Patents [OSTI]

    Fisch, Nathaniel J. (Princeton, NJ); Boozer, Allen H. (Rocky Hill, NJ)

    1984-01-01T23:59:59.000Z

    A system for the generation of toroidal current in a plasma which is prepared in a toroidal magnetic field. The system utilizes the injection of high-frequency waves into the plasma by means of waveguides. The wave frequency and polarization are chosen such that when the waveguides are tilted in a predetermined fashion, the wave energy is absorbed preferentially by electrons traveling in one toroidal direction. The absorption of energy in this manner produces a toroidal electric current even when the injected waves themselves do not have substantial toroidal momentum. This current can be continuously maintained at modest cost in power and may be used to confine the plasma. The system can operate efficiently on fusion grade tokamak plasmas.

  11. Research and Technology in Wave Energy for Electric Mobility

    E-Print Network [OSTI]

    Frandsen, Jannette B.

    generated by ocean current and energy extraction through ocean thermal conversion (OTEC). For wave energy renewable energy in the oceans, the utilization of such power has been far from full or even effectiveResearch and Technology in Wave Energy for Electric Mobility Reza Ghorbani Assistant Professor

  12. Excitation of terahertz nanoantennas by Rabi waves

    SciTech Connect (OSTI)

    Slepyan, G. Ya.; Yerchak, Y. D.; Maksimenko, S. A. [Institute for Nuclear Problems, Belarus State University, Bobruiskaya 11, 220030 Minsk (Belarus); Hoffmann, A. [Institut fuer Festkoerperphysik, Technische Universitaet Berlin, Hardenbergstrasse 36, 10623 Berlin (Germany); Bass, F. G. [Department of Physics, Bar-Ilan University, 52900 Ramat-Gan (Israel)

    2011-10-03T23:59:59.000Z

    Theoretical model of quantum dot ring, strongly coupled with classical electromagnetic field, is developed. We demonstrate, that tunnel current in the QD-ring has low-frequency component, excited by Rabi waves, propagating into the ring, and the ring can be considered as a candidate for role of terahertz magnetic loop antenna. The low-frequency current is inspired by the asymmetry of electron tunneling.

  13. Simulation of anisotropic wave propagation in Vertical Seismic Profiles

    E-Print Network [OSTI]

    Durussel, Vincent Bernard

    2004-09-30T23:59:59.000Z

    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...

  14. Theoretical modelling of two wave-power devices

    E-Print Network [OSTI]

    Lovas, Stéphanie

    2010-01-01T23:59:59.000Z

    Many wave energy devices are currently studied. In this thesis we focus on two specific devices: the Oscillating Water Column (OWC), and the buoys. In the first part of this thesis we examine the effects of coastline ...

  15. Current measurement apparatus

    DOE Patents [OSTI]

    Umans, Stephen D. (Belmont, MA)

    2008-11-11T23:59:59.000Z

    Apparatus and methods are provided for a system for measurement of a current in a conductor such that the conductor current may be momentarily directed to a current measurement element in order to maintain proper current without significantly increasing an amount of power dissipation attributable to the current measurement element or adding resistance to assist in current measurement. The apparatus and methods described herein are useful in superconducting circuits where it is necessary to monitor current carried by the superconducting elements while minimizing the effects of power dissipation attributable to the current measurement element.

  16. MAKING WAVES AT FAU FLORIDA ATLANTIC UNIVERSITY

    E-Print Network [OSTI]

    Fernandez, Eduardo

    to generate energy by harnessing the power of Florida's ocean currents. FAU has been named to Military TimesMAKING WAVES AT FAU FLORIDA ATLANTIC UNIVERSITY QUICK FACTS #12;About FAu 1 PeoPle 7 AcAdemics 12 Marine Renewable Energy Center, a federally funded research facility that is developing technology

  17. Gravitational waves emitted by solar-type stars excited by orbiting planets

    E-Print Network [OSTI]

    Emanuele Berti; Valeria Ferrari

    2000-11-30T23:59:59.000Z

    The possibility of exciting the g-modes of a solar-type star as a consequence of the gravitational interaction with a close companion (a planet or a brown dwarf) is studied by a perturbative approach. The amplitude of the emitted gravitational wave is computed and compared with the quadrupole emission of the system, showing that in some cases it can be considerably larger. The effects of radiation reaction are considered to evaluate the timescale of the emission process, and a Roche lobe analysis is used to establish the region where the companion can orbit without being disrupted by tidal interactions with the star.

  18. A comparison between matter wave and light wave interferometers for the detection of gravitational waves

    E-Print Network [OSTI]

    Pacôme Delva; Marie-Christine Angonin; Philippe Tourrenc

    2006-09-20T23:59:59.000Z

    We calculate and compare the response of light wave interferometers and matter wave interferometers to gravitational waves. We find that metric matter wave interferometers will not challenge kilometric light wave interferometers such as Virgo or LIGO, but could be a good candidate for the detection of very low frequency gravitational waves.

  19. Cycloidal Wave Energy Converter

    SciTech Connect (OSTI)

    Stefan G. Siegel, Ph.D.

    2012-11-30T23:59:59.000Z

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

  20. TIDAL TAIL EJECTION AS A SIGNATURE OF TYPE Ia SUPERNOVAE FROM WHITE DWARF MERGERS

    SciTech Connect (OSTI)

    Raskin, Cody; Kasen, Daniel [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

    2013-07-20T23:59:59.000Z

    The merger of two white dwarfs may be preceded by the ejection of some mass in ''tidal tails,'' creating a circumstellar medium around the system. We consider the variety of observational signatures from this material, which depend on the lag time between the start of the merger and the ultimate explosion (assuming one occurs) of the system in a Type Ia supernova (SN Ia). If the time lag is fairly short, then the interaction of the supernova ejecta with the tails could lead to detectable shock emission at radio, optical, and/or X-ray wavelengths. At somewhat later times, the tails produce relatively broad NaID absorption lines with velocity widths of the order of the white dwarf escape speed ({approx}1000 km s{sup -1}). That none of these signatures have been detected in normal SNe Ia constrains the lag time to be either very short ({approx}< 100 s) or fairly long ({approx}> 100 yr). If the tails have expanded and cooled over timescales {approx}10{sup 4} yr, then they could be observable through narrow NaID and Ca II H and K absorption lines in the spectra, which are seen in some fraction of SNe Ia. Using a combination of three-dimensional and one-dimensional hydrodynamical codes, we model the mass loss from tidal interactions in binary systems, and the subsequent interactions with the interstellar medium, which produce a slow-moving, dense shell of gas. We synthesize NaID line profiles by ray casting through this shell, and show that in some circumstances tidal tails could be responsible for narrow absorptions similar to those observed.

  1. Vehicle Trajectory Reconstruction for Signalized Intersections Using Variational Formulation of Kinematic Waves

    E-Print Network [OSTI]

    Ban, Xuegang "Jeff"

    of Kinematic Waves Zhanbo Sun Department of Civil and Environmental Engineering Rensselaer Polytechnic trajectories are considered. The method is5 based on the Variational Formulation of kinematic wave theory; Kinematic Wave Theory; Shortest Path Search17 #12;2 1. Introduction and Motivation18 Current traffic

  2. Do flares in Sagittarius A* reflect the last stage of tidal capture?

    E-Print Network [OSTI]

    A. Cadez; M. Calvani; A. Gomboc; U. Kostic

    2007-09-03T23:59:59.000Z

    In recent years the case for the presence of 3-4 10^6 M_sun black hole in our Galactic Center has gained strength from results of stellar dynamics observations and from the detection of several rapid X-ray and IR flares observed in the Sagittarius A* from 2000 to 2004. Here we explore the idea that such flares are produced when the central black hole tidally captures and disrupts a small body - e.g. a comet or an asteroid.

  3. MHK Projects/Cape Cod Tidal Energy Project | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAK Technologies Jump to:BW2 Tidal <CETO La Reunion

  4. MHK Projects/Cape Islands Tidal Energy Project | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAK Technologies Jump to:BW2 Tidal <CETO La ReunionCape Islands

  5. MHK Projects/Central Cook Inlet Alaska Tidal Energy Project | Open Energy

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAK Technologies Jump to:BW2 Tidal <CETO LaCat Island

  6. MHK Projects/Central Cook Inlet Tidal Energy Project | Open Energy

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAK Technologies Jump to:BW2 Tidal <CETO LaCat

  7. MHK Projects/Edgar Town Nantucket Tidal Energy | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAK Technologies Jump to:BW2 TidalMar Landing

  8. MHK Projects/Fishers Island Tidal Energy Project | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAK Technologies Jump to:BW2 TidalMarFalmouth < MHKFigueira

  9. Electron Bernstein Wave Studies in MST

    SciTech Connect (OSTI)

    Seltzman, Andrew H.; Anderson, Jay K.; Nonn, Paul D.; Kauffold, Jason X.; Forest, Cary B. [University of Wisconsin-Madison, Dept. Of Physics, 1150 University Ave., Madison, WI 53706 (United States); Diem, Stephanie J. [Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831 (United States)

    2011-12-23T23:59:59.000Z

    The overdense plasma in an RFP prevents electromagnetic waves from propagating past the edge, however use of the electron Bernstein wave (EBW) has the potential to heat and drive current in the plasma. MHD simulations have demonstrated that resistive tearing mode stability is very sensitive to gradients in the edge current density profile allowing EBW to potentially be a stabilizing influence. A new MW level experiment is being commissioned on MST to evaluate the potential use of the EBW for current profile control on the RFP. The development of new equipment includes a 5.5 GHz klystron driven by a novel switchmode power supply. A quartz window has been constructed and coupling with a cylindrical molybdenum wave guide antenna has been studied. Due to the steep edge density gradient in the RFP, it is possible to efficiently couple to the EBW with O or X mode launch. The EBW is strongly damped at the electron cyclotron resonance where it couples to the electron gyromotion and alters the electron distribution. Either Fisch-Boozer or Ohkawa current drive mechanisms can be activated to drive off axis current in the plasma. Preliminary experiments have been performed to verify high power coupling and understand heating via observed x-ray emission when compared to Fokker-Plank modeling in CQL3D.

  10. Electron Bernstein waves in spherical torus plasmas

    SciTech Connect (OSTI)

    Saveliev, A. N. [A.F.Ioffe Physico-Technical Institute, Politekhnicheskaya 26, 194021 St. Petersburg (Russian Federation)

    2006-11-30T23:59:59.000Z

    Propagation and absorption of the electron Bernstein waves (EBWs) in spherical tokamaks (STs) have been intensively discussed in recent years because the EBWs coupled with an externally launched electromagnetic beam seem to be the only opportunity for microwave plasma heating and current drive in the electron cyclotron (EC) frequency range in the STs. The whole problem of the electron Bernstein heating and current drive (EBWHCD) in spherical plasmas is naturally divided into three major parts: coupling of incident electromagnetic waves (EMWs) to the EBWs near the upper hybrid resonance (UHR) surface, propagation and absorption of the EBWs in the plasma interior and generation of noninductive current driven by the EBWs. The present paper is a brief survey of the most important theoretical and numerical results on the issue of EBWs.

  11. Structure-borne sound Flexural wave (bending wave)

    E-Print Network [OSTI]

    Berlin,Technische Universität

    1 Structure-borne sound · Flexural wave (bending wave) »One dimensional (beam) +(/x)dx +(/x)dx = (/x) (/x)dx=(2/x2)dx Mz +(Mz/x)dx Mz vy Fy Fy +(Fy/x)dx Structure-borne sound · Bending wave ­ flexural wave #12;2 Structure-borne sound · Two obliquely propagating waves + - + + - + - Structure

  12. Wave Propagation Theory 2.1 The Wave Equation

    E-Print Network [OSTI]

    2 Wave Propagation Theory 2.1 The Wave Equation The wave equation in an ideal fluid can be derived #12;66 2. Wave Propagation Theory quantities of the quiescent (time independent) medium are identified perturbations is much smaller than the speed of sound. 2.1.1 The Nonlinear Wave Equation Retaining higher

  13. Wave momentum flux parameter: a descriptor for nearshore waves

    E-Print Network [OSTI]

    US Army Corps of Engineers

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

  14. Shallow Water Waves and Solitary Waves Willy Hereman

    E-Print Network [OSTI]

    Hereman, Willy A.M.

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

  15. New wave generation

    E-Print Network [OSTI]

    Mercier, Matthieu J; Mathur, Manikandan; Gostiaux, Louis; Peacock, Thomas; Dauxois, Thierry

    2015-01-01T23:59:59.000Z

    We present the results of a combined experimental and numerical study of the generation of internal waves using the novel internal wave generator design of Gostiaux et al. (2007). This mechanism, which involves a tunable source comprised of oscillating plates, has so far been used for a few fundamental studies of internal waves, but its full potential has yet to be realized. Our studies reveal that this approach is capable of producing a wide variety of two-dimensional wave fields, including plane waves, wave beams and discrete vertical modes in finite-depth stratifications. The effects of discretization by a finite number of plates, forcing amplitude and angle of propagation are investigated, and it is found that the method is remarkably efficient at generating a complete wave field despite forcing only one velocity component in a controllable manner. We furthermore find that the nature of the radiated wave field is well predicted using Fourier transforms of the spatial structure of the wave generator.

  16. Directed Relativistic Blast Wave

    E-Print Network [OSTI]

    Andrei Gruzinov

    2007-04-23T23:59:59.000Z

    A spherically symmetrical ultra-relativistic blast wave is not an attractor of a generic asymmetric explosion. Spherical symmetry is reached only by the time the blast wave slows down to non-relativistic velocities, when the Sedov-Taylor-von Neumann attractor solution sets in. We show however, that a directed relativistic explosion, with the explosion momentum close to the explosion energy, produces a blast wave with a universal intermediate asymptotic -- a selfsimilar directed ultra-relativistic blast wave. This universality might be of interest for the astrophysics of gamma-ray burst afterglows.

  17. Nonlinear Lattice Waves in Random Potentials

    E-Print Network [OSTI]

    Sergej Flach

    2014-09-10T23:59:59.000Z

    Localization of waves by disorder is a fundamental physical problem encompassing a diverse spectrum of theoretical, experimental and numerical studies in the context of metal-insulator transition, quantum Hall effect, light propagation in photonic crystals, and dynamics of ultra-cold atoms in optical arrays. Large intensity light can induce nonlinear response, ultracold atomic gases can be tuned into an interacting regime, which leads again to nonlinear wave equations on a mean field level. The interplay between disorder and nonlinearity, their localizing and delocalizing effects is currently an intriguing and challenging issue in the field. We will discuss recent advances in the dynamics of nonlinear lattice waves in random potentials. In the absence of nonlinear terms in the wave equations, Anderson localization is leading to a halt of wave packet spreading. Nonlinearity couples localized eigenstates and, potentially, enables spreading and destruction of Anderson localization due to nonintegrability, chaos and decoherence. The spreading process is characterized by universal subdiffusive laws due to nonlinear diffusion. We review extensive computational studies for one- and two-dimensional systems with tunable nonlinearity power. We also briefly discuss extensions to other cases where the linear wave equation features localization: Aubry-Andre localization with quasiperiodic potentials, Wannier-Stark localization with dc fields, and dynamical localization in momentum space with kicked rotors.

  18. A Synthesis of Environmental and Plant Community Data for Tidal Wetland Restoration Planning in the Lower Columbia River and Estuary

    SciTech Connect (OSTI)

    Diefenderfer, Heida L.; Borde, Amy B.; Cullinan, Valerie I.

    2013-12-01T23:59:59.000Z

    This report reanalyzes and synthesizes previously existing environmental and plant community data collected by PNNL at 55 tidal wetlands and 3 newly restored sites in the lower Columbia River and estuary (LCRE) between 2005 and 2011. Whereas data were originally collected for various research or monitoring objectives of five studies, the intent of this report is to provide only information that will have direct utility in planning tidal wetland restoration projects. Therefore, for this report, all tidal wetland data on plants and the physical environment, which were originally developed and reported by separate studies, were tabulated and reanalyzed as a whole. The geographic scope of the data collected in this report is from Bonneville Lock and Dam to the mouth of the Columbia River

  19. GRB060218 AS A TIDAL DISRUPTION OF A WHITE DWARF BY AN INTERMEDIATE-MASS BLACK HOLE

    SciTech Connect (OSTI)

    Shcherbakov, Roman V.; Reynolds, Christopher S. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Pe'er, Asaf [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Haas, Roland [Theoretical AstroPhysics Including Relativity, California Institute of Technology, Pasadena, CA 91125 (United States); Bode, Tanja; Laguna, Pablo [Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, Atlanta, GA 30332 (United States)

    2013-06-01T23:59:59.000Z

    The highly unusual pair of a gamma-ray burst (GRB) GRB060218 and an associated supernova, SN2006aj, has puzzled theorists for years. A supernova shock breakout and a jet from a newborn stellar mass compact object have been proposed to explain this pair's multiwavelength signature. Alternatively, we propose that the source is naturally explained by another channel: the tidal disruption of a white dwarf (WD) by an intermediate-mass black hole (IMBH). This tidal disruption is accompanied by a tidal pinching, which leads to the ignition of a WD and a supernova. Some debris falls back onto the IMBH, forms a disk, which quickly amplifies the magnetic field, and launches a jet. We successfully fit soft X-ray spectra with the Comptonized blackbody emission from a jet photosphere. The optical/UV emission is consistent with self-absorbed synchrotron emission from the expanding jet front. The temporal dependence of the accretion rate M-dot (t) in a tidal disruption provides a good fit to the soft X-ray light curve. The IMBH mass is found to be about 10{sup 4} M{sub Sun} in three independent estimates: (1) fitting the tidal disruption M-dot (t) to the soft X-ray light curve, (2) computing the jet base radius in a jet photospheric emission model, and (3) inferring the mass of the central black hole based on the host dwarf galaxy's stellar mass. The position of the supernova is consistent with the center of the host galaxy, while the low supernova ejecta mass is consistent with that of a WD. The high expected rate of tidal disruptions in dwarf galaxies is consistent with one source observed by the Swift satellite over several years at a distance of 150 Mpc measured for GRB060218. Encounters with WDs provide much fuel for the growth of IMBHs.

  20. Hydraulic Geometry and Microtopography of Tidal Freshwater Forested Wetlands and Implications for Restoration, Columbia River, U.S.A.

    SciTech Connect (OSTI)

    Diefenderfer, Heida L.; Coleman, Andre M.; Borde, Amy B.; Sinks, Ian A.

    2008-01-01T23:59:59.000Z

    The hydrologic reconnection of tidal channels, riverine floodplains, and main stem channels are among responses by ecological restoration practitioners to the increasing fragmentation and land conversion occurring in coastal and riparian zones. Design standards and monitoring of such ecological restoration depend upon the characterization of reference sites that vary within and among regions. Few locales, such as the 235 km tidal portion of the Columbia River on the West Coast U.S.A., remain in which the reference conditions and restoration responses of tidal freshwater forested wetlands on temperate zone large river floodplains can be compared. This study developed hydraulic geometry relationships for Picea sitchensis (Sitka spruce) dominated tidal forests (swamps) in the vicinity of Grays Bay on the Columbia River some 37 km from the Pacific Coast using field surveys and Light Detection and Ranging (LiDAR) data. Scaling relationships between catchment area and the parameters of channel cross-sectional area at outlet and total channel length were comparable to tidally influenced systems of San Francisco Bay and the United Kingdom. Dike breaching, culvert replacement, and tide gate replacement all affected channel cross-sectional geometry through changes in the frequency of over-marsh flows. Radiocarbon dating of buried wood provided evidence of changes in sedimentation rates associated with diking, and restoration trajectories may be confounded by historical subsidence behind dikes rendering topographical relationships with water level incomparable to reference conditions. At the same time, buried wood is influencing the development of channel morphology toward characteristics resembling reference conditions. Ecological restoration goals and practices in tidal forested wetland regions of large river floodplains should reflect the interactions of these controlling factors.

  1. Soft Capacitors for Wave Energy Harvesting

    E-Print Network [OSTI]

    Karsten Ahnert; Markus Abel; Matthias Kollosche; Per Jřrgen Jřrgensen; Guggi Kofod

    2011-10-14T23:59:59.000Z

    Wave energy harvesting could be a substantial renewable energy source without impact on the global climate and ecology, yet practical attempts have struggle d with problems of wear and catastrophic failure. An innovative technology for ocean wave energy harvesting was recently proposed, based on the use of soft capacitors. This study presents a realistic theoretical and numerical model for the quantitative characterization of this harvesting method. Parameter regio ns with optimal behavior are found, and novel material descriptors are determined which simplify analysis dramatically. The characteristics of currently ava ilable material are evaluated, and found to merit a very conservative estimate of 10 years for raw material cost recovery.

  2. Supercurrent in a p-wave holographic superconductor

    SciTech Connect (OSTI)

    Zeng Huabi [Department of Physics, Nanjing University, Nanjing 210093 (China); Sun Weimin; Zong Hongshi [Department of Physics, Nanjing University, Nanjing 210093 (China); Joint Center for Particle, Nuclear Physics and Cosmology, Nanjing 210093 (China)

    2011-02-15T23:59:59.000Z

    The p-wave and p+ip-wave holographic superconductors with fixed DC supercurrent are studied by introducing a nonvanishing vector potential. We find that close to the critical temperature T{sub c} of zero current, the numerical results of both the p-wave model and the p+ip model are the same as those of Ginzburg-Landau (GL) theory; for example, the critical current is j{sub c}{approx}(T{sub c}-T){sup 3/2} and the phase transition in the presence of a DC current is a first-order transition. Beside the similar results between both models, the p+ip superconductor shows isotropic behavior for the supercurrent, while the p-wave superconductor shows anisotropic behavior for the supercurrent.

  3. Deployment Effects of Marine Renewable Energy Technologies: Wave Energy Scenarios

    SciTech Connect (OSTI)

    Mirko Previsic

    2010-06-17T23:59:59.000Z

    Given proper care in siting, design, deployment, operation and maintenance, wave energy conversion could become one of the more environmentally benign sources of electricity generation. In order to accelerate the adoption of these emerging hydrokinetic and marine energy technologies, navigational and environmental concerns must be identified and addressed. All developing hydrokinetic projects involve a wide variety of stakeholders. One of the key issues that site developers face as they engage with this range of stakeholders is that, due to a lack of technical certainty, many of the possible conflicts (e.g., shipping and fishing) and environmental issues are not well-understood,. In September 2008, re vision consulting, LLC was selected by the Department of Energy (DoE) to apply a scenario-based assessment to the emerging hydrokinetic technology sector in order to evaluate the potential impact of these technologies on the marine environment and navigation constraints. The project’s scope of work includes the establishment of baseline scenarios for wave and tidal power conversion at potential future deployment sites. The scenarios capture variations in technical approaches and deployment scales to properly identify and characterize environmental effects and navigational effects. The goal of the project is to provide all stakeholders with an improved understanding of the potential range of technical attributes and potential effects of these emerging technologies and focus all stakeholders on the critical issues that need to be addressed. By identifying and addressing navigational and environmental concerns in the early stages of the industry’s development, serious mistakes that could potentially derail industry-wide development can be avoided. This groundwork will also help in streamlining siting and associated permitting processes, which are considered key hurdles for the industry’s development in the U.S. today. Re vision is coordinating its efforts with two other project teams funded by DoE which are focused on regulatory issues (Pacific Energy Ventures) and navigational issues (PCCI). The results of this study are structured into three reports: (1) Wave power scenario description (2) Tidal power scenario description (3) Framework for Identifying Key Environmental Concerns This is the first report in the sequence and describes the results of conceptual feasibility studies of wave power plants deployed in Humboldt County, California and Oahu, Hawaii. These two sites contain many of the same competing stakeholder interactions identified at other wave power sites in the U.S. and serve as representative case studies. Wave power remains at an early stage of development. As such, a wide range of different technologies are being pursued by different manufacturers. In order to properly characterize potential effects, it is useful to characterize the range of technologies that could be deployed at the site of interest. An industry survey informed the process of selecting representative wave power devices. The selection criteria requires that devices are at an advanced stage of development to reduce technical uncertainties, and that enough data are available from the manufacturers to inform the conceptual design process of this study. Further, an attempt is made to cover the range of different technologies under development to capture variations in potential environmental effects. Table 1 summarizes the selected wave power technologies. A number of other developers are also at an advanced stage of development, but are not directly mentioned here. Many environmental effects will largely scale with the size of the wave power plant. In many cases, the effects of a single device may not be measurable, while larger scale device arrays may have cumulative impacts that differ significantly from smaller scale deployments. In order to characterize these effects, scenarios are established at three deployment scales which nominally represent (1) a small pilot deployment, (2) a small commercial deployment, and (3) a large commercial sc

  4. High-Current Accelerators

    E-Print Network [OSTI]

    Lawrence, Ernest O.

    1955-01-01T23:59:59.000Z

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

  5. Ecology of Juvenile Salmon in Shallow Tidal Freshwater Habitats of the Lower Columbia River, 2007–2010

    SciTech Connect (OSTI)

    Johnson, Gary E.; Storch, Adam; Skalski, J. R.; Bryson, Amanda J.; Mallette, Christine; Borde, Amy B.; Van Dyke, E.; Sobocinski, Kathryn L.; Sather, Nichole K.; Teel, David; Dawley, Earl M.; Ploskey, Gene R.; Jones, Tucker A.; Zimmerman, Shon A.; Kuligowski, D. R.

    2011-03-01T23:59:59.000Z

    The TFM study was designed to investigate the ecology and early life history of juvenile salmonids within shallow (<5 m) tidal freshwater habitats of the LCRE. We started collecting field data in June 2007. Since then, monthly sampling has occurred in the vicinity of the Sandy River delta (rkm 192–208) and at other sites and times in lower river reaches of tidal freshwater (rkm 110 to 141). This report provides a comprehensive synthesis of data covering the field period from June 2007 through April 2010.

  6. OBLIQUITIES OF HOT JUPITER HOST STARS: EVIDENCE FOR TIDAL INTERACTIONS AND PRIMORDIAL MISALIGNMENTS

    SciTech Connect (OSTI)

    Albrecht, Simon; Winn, Joshua N. [Department of Physics, and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Johnson, John A. [Department of Astrophysics, California Institute of Technology, MC249-17, Pasadena, CA 91125 (United States); Howard, Andrew W.; Marcy, Geoffrey W. [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); Butler, R. Paul [Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road NW, Washington, DC 20015 (United States); Arriagada, Pamela [Department of Astronomy, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile); Crane, Jeffrey D.; Shectman, Stephen A.; Thompson, Ian B. [The Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Hirano, Teruyuki [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Bakos, Gaspar; Hartman, Joel D. [Department of Astrophysical Sciences, Princeton University, Peyton Hall, Princeton, NJ 08544 (United States)

    2012-09-20T23:59:59.000Z

    We provide evidence that the obliquities of stars with close-in giant planets were initially nearly random, and that the low obliquities that are often observed are a consequence of star-planet tidal interactions. The evidence is based on 14 new measurements of the Rossiter-McLaughlin effect (for the systems HAT-P-6, HAT-P-7, HAT-P-16, HAT-P-24, HAT-P-32, HAT-P-34, WASP-12, WASP-16, WASP-18, WASP-19, WASP-26, WASP-31, Gl 436, and Kepler-8), as well as a critical review of previous observations. The low-obliquity (well-aligned) systems are those for which the expected tidal timescale is short, and likewise the high-obliquity (misaligned and retrograde) systems are those for which the expected timescale is long. At face value, this finding indicates that the origin of hot Jupiters involves dynamical interactions like planet-planet interactions or the Kozai effect that tilt their orbits rather than inspiraling due to interaction with a protoplanetary disk. We discuss the status of this hypothesis and the observations that are needed for a more definitive conclusion.

  7. The flattenings of the layers of rotating planets and satellites deformed by a tidal potential

    E-Print Network [OSTI]

    Folonier, Hugo; Kholshevnikov, Konstantin V

    2015-01-01T23:59:59.000Z

    We consider the Clairaut theory of the equilibrium ellipsoidal figures for differentiated non-homogeneous bodies in non-synchronous rotation adding to it a tidal deformation due to the presence of an external gravitational force. We assume that the body is a fluid formed by $n$ homogeneous layers of ellipsoidal shape and we calculate the external polar flattenings and the mean radius of each layer, or, equivalently, their semiaxes. To first order in the flattenings, the general solution can be written as $\\epsilon_k={\\cal H}_k*\\epsilon_h$ and $\\mu_k={\\cal H}_k*\\mu_h$, where $\\cal{H}_k$ is a characteristic coefficient for each layer which only depends on the internal structure of the body and $\\epsilon_h, \\mu_h$ are the flattenings of the equivalent homogeneous problem. For the continuous case, we study the Clairaut differential equation for the flattening profile, using the Radau transformation to find the boundary conditions when the tidal potential is added. Finally, the theory is applied to several example...

  8. Revealing the escape mechanism of three-dimensional orbits in a tidally limited star cluster

    E-Print Network [OSTI]

    Euaggelos E. Zotos

    2014-11-18T23:59:59.000Z

    The aim of this work is to explore the escape process of three-dimensional orbits in a star cluster rotating around its parent galaxy in a circular orbit. The gravitational field of the cluster is represented by a smooth, spherically symmetric Plummer potential, while the tidal approximation was used to model the steady tidal field of the galaxy. We conduct a thorough numerical analysis distinguishing between regular and chaotic orbits as well as between trapped and escaping orbits, considering only unbounded motion for several energy levels. It is of particular interest to locate the escape basins towards the two exit channels and relate them with the corresponding escape times of the orbits. For this purpose, we split our investigation into three cases depending on the initial value of the $z$ coordinate which was used for launching the stars. The most noticeable finding is that the majority of stars initiated very close to the primary $(x,y)$ plane move in chaotic orbits and they remain trapped for vast time intervals, while orbits with relatively high values of $z_0$ on the other hand, form well-defined basins of escape. It was also observed, that for energy levels close to the critical escape energy the escape rates of orbits are large, while for much higher values of energy most of the orbits have low escape periods or they escape immediately to infinity. We hope our outcomes to be useful for a further understanding of the dissolution process and the escape mechanism in open star clusters.

  9. Wave runup on cylinders subject to deep water random waves

    E-Print Network [OSTI]

    Indrebo, Ann Kristin

    2012-06-07T23:59:59.000Z

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

  10. Wave-Corpuscle Mechanics for Electric Charges

    E-Print Network [OSTI]

    Babin, Anatoli; Figotin, Alexander

    2010-01-01T23:59:59.000Z

    superposition in nonlinear wave dynamics. Rev. Math. Phys.6. Babin, A. , Figotin, A. : Wave-corpuscle mechanics forV. , Fortunato, D. : Solitary waves in the nonlinear wave

  11. Method and apparatus for generating motor current spectra to enhance motor system fault detection

    DOE Patents [OSTI]

    Linehan, Daniel J. (Knoxville, TN); Bunch, Stanley L. (Oak Ridge, TN); Lyster, Carl T. (Knoxville, TN)

    1995-01-01T23:59:59.000Z

    A method and circuitry for sampling periodic amplitude modulations in a nonstationary periodic carrier wave to determine frequencies in the amplitude modulations. The method and circuit are described in terms of an improved motor current signature analysis. The method insures that the sampled data set contains an exact whole number of carrier wave cycles by defining the rate at which samples of motor current data are collected. The circuitry insures that a sampled data set containing stationary carrier waves is recreated from the analog motor current signal containing nonstationary carrier waves by conditioning the actual sampling rate to adjust with the frequency variations in the carrier wave. After the sampled data is transformed to the frequency domain via the Discrete Fourier Transform, the frequency distribution in the discrete spectra of those components due to the carrier wave and its harmonics will be minimized so that signals of interest are more easily analyzed.

  12. Method and apparatus for generating motor current spectra to enhance motor system fault detection

    DOE Patents [OSTI]

    Linehan, D.J.; Bunch, S.L.; Lyster, C.T.

    1995-10-24T23:59:59.000Z

    A method and circuitry are disclosed for sampling periodic amplitude modulations in a nonstationary periodic carrier wave to determine frequencies in the amplitude modulations. The method and circuit are described in terms of an improved motor current signature analysis. The method insures that the sampled data set contains an exact whole number of carrier wave cycles by defining the rate at which samples of motor current data are collected. The circuitry insures that a sampled data set containing stationary carrier waves is recreated from the analog motor current signal containing nonstationary carrier waves by conditioning the actual sampling rate to adjust with the frequency variations in the carrier wave. After the sampled data is transformed to the frequency domain via the Discrete Fourier Transform, the frequency distribution in the discrete spectra of those components due to the carrier wave and its harmonics will be minimized so that signals of interest are more easily analyzed. 29 figs.

  13. Current to Current | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 NoPublic Utilities Address: 160Benin:EnergyWisconsin:2003)Crowley County,Curran, Illinois: EnergyCurrentCurrent to

  14. Self-consistent full wave simulations of lower hybrid waves

    E-Print Network [OSTI]

    Wright, John C.

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

  15. Harmonic generation of gravitational wave induced Alfven waves

    E-Print Network [OSTI]

    Mats Forsberg; Gert Brodin

    2007-11-26T23:59:59.000Z

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

  16. Developing de Broglie Wave

    E-Print Network [OSTI]

    J X Zheng-Johansson; P-I Johansson

    2006-08-27T23:59:59.000Z

    The electromagnetic component waves, comprising together with their generating oscillatory massless charge a material particle, will be Doppler shifted when the charge hence particle is in motion, with a velocity $v$, as a mere mechanical consequence of the source motion. We illustrate here that two such component waves generated in opposite directions and propagating at speed $c$ between walls in a one-dimensional box, superpose into a traveling beat wave of wavelength ${\\mit\\Lambda}_d$$=(\\frac{v}{c}){\\mit\\Lambda}$ and phase velocity $c^2/v+v$ which resembles directly L. de Broglie's hypothetic phase wave. This phase wave in terms of transporting the particle mass at the speed $v$ and angular frequency ${\\mit\\Omega}_d=2\\pi v /{\\mit\\Lambda}_d$, with ${\\mit\\Lambda}_d$ and ${\\mit\\Omega}_d$ obeying the de Broglie relations, represents a de Broglie wave. The standing-wave function of the de Broglie (phase) wave and its variables for particle dynamics in small geometries are equivalent to the eigen-state solutions to Schr\\"odinger equation of an identical system.

  17. Generation of the longitudinal current by the transversal electromagnetic field in classical and quantum plasmas

    E-Print Network [OSTI]

    Latyshev, A V

    2015-01-01T23:59:59.000Z

    From Vlasov kinetic equation for collisionless plasmas distribution function in square-law approximation on size of electromagnetic field is received. Formulas for calculation electric current at any temperature (any degree of degeneration of electronic gas) are deduced. The case of small values of the wave numbers is considered. It is shown, that the nonlinearity account leads to occurrence the longitudinal electric current directed along a wave vector. This longitudinal current orthogonal to known transversal classical current, received at the linear analysis. From the kinetic equation with Wigner integral for collisionless quantum plasma distribution function is received in square-law on vector potential approximation. Formulas for calculation electric current at any temperature are deduced. The case of small values of wave number is considered. It is shown, that size of a longitudinal current at small values of wave number and for classical plasma and for quantum plasma coincide. Graphic comparison of dim...

  18. Secondary dust density waves excited by nonlinear dust acoustic waves

    SciTech Connect (OSTI)

    Heinrich, J. R.; Kim, S.-H.; Meyer, J. K.; Merlino, R. L. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States); Rosenberg, M. [Department of Electrical and Computer Engineering, University of California, San Diego, California 92093 (United States)

    2012-08-15T23:59:59.000Z

    Secondary dust density waves were observed in conjunction with high amplitude (n{sub d}/n{sub d0}>2) dust acoustic waves (DAW) that were spontaneously excited in a dc glow discharge dusty plasma in the moderately coupled, {Gamma}{approx}1, state. The high amplitude dust acoustic waves produced large dust particle oscillations, displacements, and trapping. Secondary dust density waves were excited in the wave troughs of the high amplitude DAWs. The waveforms, amplitudes, wavelengths, and wave speeds of the primary DAWs and the secondary waves were measured. A dust-dust streaming instability is discussed as a possible mechanism for the production of the secondary waves.

  19. Center for Wave Phenomena Wave Phenomena

    E-Print Network [OSTI]

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

  20. Rainbow trapping of guided waves

    E-Print Network [OSTI]

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

    2011-01-01T23:59:59.000Z

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

  1. Arnold Schwarzenegger CALIFORNIA OCEAN WAVE

    E-Print Network [OSTI]

    Arnold Schwarzenegger Governor CALIFORNIA OCEAN WAVE ENERGY ASSESSMENT Prepared For: California this report as follows: Previsic, Mirko. 2006. California Ocean Wave Energy Assessment. California Energy Systems Integration · Transportation California Ocean Wave Energy Assessment is the final report

  2. Experimental determination of radiated internal wave power without pressure field data

    SciTech Connect (OSTI)

    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

    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.

  3. Diagonalization of pp-waves

    E-Print Network [OSTI]

    B. V. Ivanov

    1997-05-21T23:59:59.000Z

    A coordinate transformation is found which diagonalizes the axisymmetric pp-waves. Its effect upon concrete solutions, including impulsive and shock waves, is discussed.

  4. Wave-wave interactions in solar type III radio bursts

    SciTech Connect (OSTI)

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

    2014-02-11T23:59:59.000Z

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

  5. JULY 2005 1 An estimate of tidal energy lost to turbulence at the Hawaiian Ridge

    E-Print Network [OSTI]

    Klymak, Jody M.

    of 2) spring-neap variation in dissipation was observed. The observations also suggest a kinematic-integrated dissipation (D), such that D E1±0.5 at sites along the ridge. This kinematic relationship is supported by combining a simple knife-edge model to estimate internal tide generation with wave-wave interaction time

  6. Environmental links to interannual variability in shellfish toxicity in Cobscook Bay and eastern Maine, a strongly tidally mixed coastal region

    E-Print Network [OSTI]

    Townsend, David W.

    Environmental links to interannual variability in shellfish toxicity in Cobscook Bay and eastern e i n f o Keywords: Harmful algal blooms Gulf of Maine Cobscook Bay Shellfish toxicity a b s t r a c of Cobscook Bay, where strong tidal mixing tends to reduce seasonal variability in oceanographic properties

  7. NAME: Sears Point Tidal Restoration Project LOCATION: Near Petaluma, CA, in the San Pablo Bay and Tolay Creek Watersheds

    E-Print Network [OSTI]

    US Army Corps of Engineers

    of estuarine habitat comprised of deep and shallow water habitat, mudflats, salt marsh, and wetlandNAME: Sears Point Tidal Restoration Project LOCATION: Near Petaluma, CA, in the San Pablo Bay PROJECT DESCRIPTION: Sears Point, the proposed project site, consists of approximately 960 acres of diked

  8. Tidally-induced thermonuclear Supernovae Stephan Rosswog1, Enrico Ramirez-Ruiz2, W. Raphael Hix3

    E-Print Network [OSTI]

    Rosswog, Stephan

    Tidally-induced thermonuclear Supernovae Stephan Rosswog1, Enrico Ramirez-Ruiz2, W. Raphael Hix3 1 in a thermonuclear explosion. These explosions are not restricted to progenitor masses close to the Chandrasekhar thermonuclear supernova together with an X-ray flare thus whistle-blows the existence of such moderate

  9. Electric current locator

    DOE Patents [OSTI]

    King, Paul E. (Corvallis, OR); Woodside, Charles Rigel (Corvallis, OR)

    2012-02-07T23:59:59.000Z

    The disclosure herein provides an apparatus for location of a quantity of current vectors in an electrical device, where the current vector has a known direction and a known relative magnitude to an input current supplied to the electrical device. Mathematical constants used in Biot-Savart superposition equations are determined for the electrical device, the orientation of the apparatus, and relative magnitude of the current vector and the input current, and the apparatus utilizes magnetic field sensors oriented to a sensing plane to provide current vector location based on the solution of the Biot-Savart superposition equations. Description of required orientations between the apparatus and the electrical device are disclosed and various methods of determining the mathematical constants are presented.

  10. Current Testbed Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Current Testbed Research Previous Testbed Research Proposal Process Terms and Conditions Dark Fiber Testbed Performance (perfSONAR) Software & Tools Development Partnerships...

  11. Theoretical study of ion toroidal rotation in the presence of lower hybrid current drive in a tokamak

    E-Print Network [OSTI]

    Lee, Jungpyo

    2013-01-01T23:59:59.000Z

    In this thesis, the effect of the lower hybrid current drive on ion toroidal rotation in a tokamak is investigated theoretically. Lower hybrid frequency waves are utilized to drive non-inductive current for steady state ...

  12. SEISMIC WAVES ESTIMATION AND WAVE FIELD DECOMPOSITION WITH FACTOR GRAPHS

    E-Print Network [OSTI]

    Loeliger, Hans-Andrea

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

  13. Taming water waves Case study: Surface Water Waves

    E-Print Network [OSTI]

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

  14. Selfconsistent full wave simulations of lower hybrid waves

    E-Print Network [OSTI]

    Wright, John C.

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

  15. On Generating Gravity Waves with Matter and Electromagnetic Waves

    E-Print Network [OSTI]

    C. Barrabes; P. A. Hogan

    2008-04-05T23:59:59.000Z

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

  16. Effect of non-uniform slow wave structure in a relativistic backward wave oscillator with a resonant reflector

    SciTech Connect (OSTI)

    Chen, Changhua; Xiao, Renzhen; Sun, Jun; Song, Zhimin; Huo, Shaofei; Bai, Xianchen; Shi, Yanchao; Liu, Guozhi [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024 (China)] [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024 (China)

    2013-11-15T23:59:59.000Z

    This paper provides a fresh insight into the effect of non-uniform slow wave structure (SWS) used in a relativistic backward wave oscillator (RBWO) with a resonant reflector. Compared with the uniform SWS, the reflection coefficient of the non-uniform SWS is higher, leading to a lower modulating electric field in the resonant reflector and a larger distance to maximize the modulation current. Moreover, for both types of RBWOs, stronger standing-wave field takes place at the rear part of the SWS. In addition, besides Cerenkov effects, the energy conversion process in the RBWO strongly depends on transit time effects. Thus, the matching condition between the distributions of harmonic current and standing wave field provides a profound influence on the beam-wave interaction. In the non-uniform RBWO, the region with a stronger standing wave field corresponds to a higher fundamental harmonic current distribution. Particle-in-cell simulations show that with a diode voltage of 1.02 MV and beam current of 13.2 kA, a microwave power of 4 GW has been obtained, compared to that of 3 GW in the uniform RBWO.

  17. A Tidally-Disrupted Asteroid Around the White Dwarf G29-38

    E-Print Network [OSTI]

    M. Jura

    2003-01-21T23:59:59.000Z

    The infrared excess around the white dwarf G29-38 can be explained by emission from an opaque flat ring of dust with an inner radius 0.14 of the radius of the Sun and an outer radius approximately equal to the Sun's. This ring lies within the Roche region of the white dwarf where an asteroid could have been tidally destroyed, producing a system reminiscent of Saturn's rings. Accretion onto the white dwarf from this circumstellar dust can explain the observed calcium abundance in the atmosphere of G29-38. Either as a bombardment by a series of asteroids or because of one large disruption, the total amount of matter accreted onto the white dwarf may have been comparable to the total mass of asteroids in the Solar System, or, equivalently, about 1% of the mass in the asteroid belt around the main sequence star zeta Lep.

  18. Surface wave interferometry 

    E-Print Network [OSTI]

    Halliday, David Fraser

    2009-01-01T23:59:59.000Z

    This thesis concerns the application of seismic interferometry to surface waves. Seismic interferometry is the process by which the wavefield between two recording locations is estimated, resulting in new recordings at ...

  19. Traveling-wave photodetector

    DOE Patents [OSTI]

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

    1993-12-14T23:59:59.000Z

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

  20. Traveling-wave photodetector

    SciTech Connect (OSTI)

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

    1992-12-31T23:59:59.000Z

    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.

  1. On the tidal interaction of massive extra-solar planets on highly eccentric orbit

    E-Print Network [OSTI]

    P. B. Ivanov; J. C. B. Papaloizou

    2003-10-09T23:59:59.000Z

    In this paper we develop a theory of disturbances induced by the stellar tidal field in a fully convective slowly rotating planet orbiting on a highly eccentric orbit around a central star. We show that there are two contributions to the mode energy and angular momentum gain due to impulsive tidal interaction: a) 'the quasi-static' contribution which requires dissipative processes operating in the planet; b) the dynamical contribution associated with excitation of modes of oscillation. These contributions are obtained self-consistently from a single set of the governing equations. We calculate a critical 'equilibrium' value of angular velocity of the planet \\Omega_{crit} determined by the condition that action of the dynamical tides does not alter the angular velocity at that rotation rate. We show that this can be much larger than the corresponding rate associated with quasi-static tides and that at this angular velocity, the rate of energy exchange is minimised. We also investigate the conditions for the stochastic increase in oscillation energy that may occur if many periastron passages are considered. We make some simple estimates of time scale of circularization of initially eccentric orbit due to tides, using a realistic model of the planet, for orbits withperiods after circularization typical of those observed for extra-solar planets P_{obs} > 3days. We find that dynamic tides could have produced a very large decrease of the semi-major axis of a planet with mass of the order of the Jupiter mass M_{J} and final periods P_{obs} < 4.5days on a time-scale < a few Gyrs. We also discuss several unresolved issues in the context of the scenario of the orbit circularization due to dynamic tides.

  2. Evidence for tidal interaction and merger as the origin of galaxy morphology evolution in compact groups

    E-Print Network [OSTI]

    R. Coziol; I. Plauchu-Frayn

    2007-02-10T23:59:59.000Z

    We present the results of a morphological study based on NIR images of 25 galaxies, with different levels of nuclear activity, in 8 Compact Groups of Galaxies (CGs). We perform independently two different analysis: a isophotal study and a study of morphological asymmetries. The results yielded by the two analysis are highly consistent. For the first time, it is possible to show that deviations from pure ellipses are produced by inhomogeneous stellar mass distributions related to galaxy interactions and mergers. We find evidence of mass asymmetries in 74% of the galaxies in our sample. In 59% of these cases, the asymmetries come in pairs, and are consistent with tidal effects produced by the proximity of companion galaxies. The symmetric galaxies are generally small in size or mass, inactive, and have an early-type morphology. In 20% of the galaxies we find evidence for cannibalism. In 36% of the early-type galaxies the color gradient is positive (blue nucleus) or flat. Summing up these results, as much as 52% of the galaxies in our sample could show evidence of an on going or past mergers. Our observations suggest that galaxies in CGs merge more frequently under ``dry'' conditions. The high frequency of interacting and merging galaxies observed in our study is consistent with the bias of our sample towards CGs of type B, which represents the most active phase in the evolution of the groups. In these groups we also find a strong correlation between asymmetries and nuclear activity in early-type galaxies. This correlation allows us to identify tidal interactions and mergers as the cause of galaxy morphology transformation in CGs.[abridge

  3. Current to Current Corporation | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 NoPublic Utilities Address: 160Benin:EnergyWisconsin:2003)Crowley County,Curran, Illinois: EnergyCurrent

  4. Ultracapacitor current collector

    DOE Patents [OSTI]

    Jerabek, Elihu Calfin (Glenmont, NY); Mikkor, Mati (Ann Arbor, MI)

    2001-10-16T23:59:59.000Z

    An ultracapacitor having two solid, nonporous current collectors, two porous electrodes separating the collectors, a porous separator between the electrodes and an electrolyte occupying the pores in the electrodes and separator. At least one of the current collectors comprises a conductive metal substrate coated with a metal nitride, carbide or boride coating.

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

    Broader source: Energy.gov (indexed) [DOE]

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

  6. Voltage controlled current source

    DOE Patents [OSTI]

    Casne, Gregory M. (Pittsburgh, PA)

    1992-01-01T23:59:59.000Z

    A seven decade, voltage controlled current source is described for use in testing intermediate range nuclear instruments that covers the entire test current range of from 10 picoamperes to 100 microamperes. High accuracy is obtained throughout the entire seven decades of output current with circuitry that includes a coordinated switching scheme responsive to the input signal from a hybrid computer to control the input voltage to an antilog amplifier, and to selectively connect a resistance to the antilog amplifier output to provide a continuous output current source as a function of a preset range of input voltage. An operator controlled switch provides current adjustment for operation in either a real-time simulation test mode or a time response test mode.

  7. Mathematical Caricature of Large Waves

    E-Print Network [OSTI]

    Mikhail Kovalyov

    2014-03-21T23:59:59.000Z

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

  8. Clustering of floaters by waves

    E-Print Network [OSTI]

    P. Denissenko; G. Falkovich; S. Lukaschuk

    2005-11-22T23:59:59.000Z

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

  9. December 2010 | 23 GUIDED WAVES

    E-Print Network [OSTI]

    Atwater, Harry

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

  10. Autoresonant Excitation of Diocotron Waves

    E-Print Network [OSTI]

    Wurtele, Jonathan

    of the wave, the pump and the wave will phase lock at very low wave amplitude. When the pump reachesAutoresonant Excitation of Diocotron Waves J. Fajans E. Gilson U.C. Berkeley L. Friedland Hebrew of phase with the oscillator, and the os- cillator's amplitude will decrease, eventually reaching zero

  11. Radio frequency wave experiments on the MST reversed field pinch

    SciTech Connect (OSTI)

    Forest, C.B.; Chattopadhyay, P.K.; Nornberg, M.D.; Prager, S.C.; Thomas, M.A. [Univ. of Wisconsin, Madison, WI (United States). Physics Dept.; Uchimoto, E. [Univ. of Montana, Missoula, MT (United States). Dept. of Physics and Astronomy; Smirnov, A.P. [Moscow State Univ. (Russian Federation); Harvey, R.W. [CompX, Del Mar, CA (United States); Ram, A.K. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Plasma Fusion Center

    1999-04-01T23:59:59.000Z

    Experiments, simulations, and theory all indicate that the magnetic fluctuations responsible for the poor confinement in the reversed field pinch (RFP) can be controlled by altering the radial profile of the current density. The magnetic fluctuations in the RFP are due to resistive MHD instabilities caused by current profile peaking; thus confinement in the RFP is ultimately the result of a misalignment between inductively driven current profiles and the stable current profiles characteristic of the Taylor state. If a technique such as rf current drive can be developed to non-inductively sustain a Taylor state (a current profile linearly stable to all tearing modes), the confinement of the RFP and its potential as a reactor concept are likely to increase. Whether there is a self-consistent path from poor confinement to greatly improved confinement through current profile modification is an issue for future experiments to address if and only if near term experiments can demonstrate: (1) coupling to and the propagation of rf waves in RFP plasmas, (2) efficient current drive, and (3) control of the power deposition which will make it possible to control the current profile. In this paper, modeling results and experimental plans are presented for two rf experiments which have the potential of satisfying these three goals: high-n{sub {parallel}} lower hybrid (LH) waves and electron Bernstein waves (EBWs).

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

    E-Print Network [OSTI]

    Jiang, Chung-Hsiang

    2010-01-01T23:59:59.000Z

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

  13. Gravitational wave detection using high precision pulsar observations

    E-Print Network [OSTI]

    G. Hobbs

    2008-02-10T23:59:59.000Z

    Pulsar timing experiments are reaching sufficient sensitivity to detect a postulated stochastic gravitational wave background generated by merging supermassive black hole systems in the cores of galaxies. We describe the techniques behind the pulsar timing detection method, provide current upper bounds on the amplitude of any gravitational wave background, describe theoretical models predicting the existence of such a background and highlight new techniques for providing a statistically rigorous detection of the background.

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

    E-Print Network [OSTI]

    Showalter, Kenneth

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

  15. System and method for generating current by selective minority species heating

    DOE Patents [OSTI]

    Fisch, Nathaniel J. (Princeton, NJ)

    1983-01-01T23:59:59.000Z

    A system for the generation of toroidal current in a plasma which is prepared in a toroidal magnetic field. The system utilizes the injection of low-frequency waves into the plasma by means of phased antenna arrays or phased waveguide arrays. The plasma is prepared with a minority ion species of different charge state and different gyrofrequency from the majority ion species. The wave frequency and wave phasing are chosen such that the wave energy is absorbed preferentially by minority species ions traveling in one toroidal direction. The absorption of energy in this manner produces a toroidal electric current even when the injected waves themselves do not have substantial toroidal momentum. This current can be continuously maintained at modest cost in power and may be used to confine the plasma. The system can operate efficiently on fusion grade tokamak plasmas.

  16. Benchmark Modeling of the Near-Field and Far-Field Wave Effects of Wave Energy Arrays

    SciTech Connect (OSTI)

    Rhinefrank, Kenneth E.; Haller, Merrick C.; Ozkan-Haller, H. Tuba

    2013-01-26T23:59:59.000Z

    This project is an industry-led partnership between Columbia Power Technologies and Oregon State University that will perform benchmark laboratory experiments and numerical modeling of the near-field and far-field impacts of wave scattering from an array of wave energy devices. These benchmark experimental observations will help to fill a gaping hole in our present knowledge of the near-field effects of multiple, floating wave energy converters and are a critical requirement for estimating the potential far-field environmental effects of wave energy arrays. The experiments will be performed at the Hinsdale Wave Research Laboratory (Oregon State University) and will utilize an array of newly developed BuoysĂ?Â?Ă?Â?Ă?Â?Ă?Âť that are realistic, lab-scale floating power converters. The array of Buoys will be subjected to realistic, directional wave forcing (1:33 scale) that will approximate the expected conditions (waves and water depths) to be found off the Central Oregon Coast. Experimental observations will include comprehensive in-situ wave and current measurements as well as a suite of novel optical measurements. These new optical capabilities will include imaging of the 3D wave scattering using a binocular stereo camera system, as well as 3D device motion tracking using a newly acquired LED system. These observing systems will capture the 3D motion history of individual Buoys as well as resolve the 3D scattered wave field; thus resolving the constructive and destructive wave interference patterns produced by the array at high resolution. These data combined with the device motion tracking will provide necessary information for array design in order to balance array performance with the mitigation of far-field impacts. As a benchmark data set, these data will be an important resource for testing of models for wave/buoy interactions, buoy performance, and far-field effects on wave and current patterns due to the presence of arrays. Under the proposed project we will initiate high-resolution (fine scale, very near-field) fluid/structure interaction simulations of buoy motions, as well as array-scale, phase-resolving wave scattering simulations. These modeling efforts will utilize state-of-the-art research quality models, which have not yet been brought to bear on this complex problem of large array wave/structure interaction problem.

  17. Current control circuitry

    DOE Patents [OSTI]

    Taubman, Matthew S. (Richland, WA)

    2005-03-15T23:59:59.000Z

    Among the embodiments of the present invention is an apparatus that includes a transistor (30), a servo device (40), and a current source (50). The servo device (40) is operable to provide a common base mode of operation of the transistor (30) by maintaining an approximately constant voltage level at the transistor base (32b). The current source (150) is operable to provide a bias current to the transistor (30). A first device (24) provides an input signal to an electrical node (70) positioned between the emitter (32e) of the transistor (30) and the current source (50). A second device (26) receives an output signal from the collector (32c) of the transistor (30).

  18. Geothermal Energy: Current abstracts

    SciTech Connect (OSTI)

    Ringe, A.C. (ed.)

    1988-02-01T23:59:59.000Z

    This bulletin announces the current worldwide information available on the technologies required for economic recovery of geothermal energy and its use as direct heat or for electric power production. (ACR)

  19. Effects of Tidal Turbine Noise on Fish Hearing and Tissues - Draft Final Report - Environmental Effects of Marine and Hydrokinetic Energy

    SciTech Connect (OSTI)

    Halvorsen, Michele B.; Carlson, Thomas J.; Copping, Andrea E.

    2011-09-30T23:59:59.000Z

    Snohomish Public Utility District No.1 plans to deploy two 6 meter OpenHydro tidal turbines in Admiralty Inlet in Puget Sound, under a FERC pilot permitting process. Regulators and stakeholders have raised questions about the potential effect of noise from the turbines on marine life. Noise in the aquatic environment is known to be a stressor to many types of aquatic life, including marine mammals, fish and birds. Marine mammals and birds are exceptionally difficult to work with for technical and regulatory reasons. Fish have been used as surrogates for other aquatic organisms as they have similar auditory structures. This project was funded under the FY09 Funding Opportunity Announcement (FOA) to Snohomish PUD, in partnership with the University of Washington - Northwest National Marine Renewable Energy Center, the Sea Mammal Research Unit, and Pacific Northwest National Laboratory. The results of this study will inform the larger research project outcomes. Proposed tidal turbine deployments in coastal waters are likely to propagate noise into nearby waters, potentially causing stress to native organisms. For this set of experiments, juvenile Chinook salmon (Oncorhynchus tshawytscha) were used as the experimental model. Plans exist for prototype tidal turbines to be deployed into their habitat. Noise is known to affect fish in many ways, such as causing a threshold shift in auditory sensitivity or tissue damage. The characteristics of noise, its spectra and level, are important factors that influence the potential for the noise to injure fish. For example, the frequency range of the tidal turbine noise includes the audiogram (frequency range of hearing) of most fish. This study was performed during FY 2011 to determine if noise generated by a 6-m diameter OpenHydro turbine might affect juvenile Chinook salmon hearing or cause barotrauma. Naturally spawning stocks of Chinook salmon that utilize Puget Sound are listed as threatened (http://www.nwr.noaa.gov/ESA-Salmon-Listings/Salmon-Populations/Chinook/CKPUG.cfm); the fish used in this experiment were hatchery raised and their populations are not in danger of depletion. After they were exposed to simulated tidal turbine noise, the hearing of juvenile Chinook salmon was measured and necropsies performed to check for tissue damage. Experimental groups were (1) noise exposed, (2) control (the same handling as treatment fish but without exposure to tidal turbine noise), and (3) baseline (never handled). Experimental results indicate that non-lethal, low levels of tissue damage may have occurred but that there were no effects of noise exposure on the auditory systems of the test fish.

  20. Beam current sensor

    DOE Patents [OSTI]

    Kuchnir, M.; Mills, F.E.

    1984-09-28T23:59:59.000Z

    A current sensor for measuring the dc component of a beam of charged particles employs a superconducting pick-up loop probe, with twisted superconducting leads in combination with a Superconducting Quantum Interference Device (SQUID) detector. The pick-up probe is in the form of a single-turn loop, or a cylindrical toroid, through which the beam is directed and within which a first magnetic flux is excluded by the Meisner effect. The SQUID detector acts as a flux-to-voltage converter in providing a current to the pick-up loop so as to establish a second magnetic flux within the electrode which nulls out the first magnetic flux. A feedback voltage within the SQUID detector represents the beam current of the particles which transit the pick-up loop. Meisner effect currents prevent changes in the magnetic field within the toroidal pick-up loop and produce a current signal independent of the beam's cross-section and its position within the toroid, while the combination of superconducting elements provides current measurement sensitivities in the nano-ampere range.

  1. Beam current sensor

    DOE Patents [OSTI]

    Kuchnir, Moyses (Elmhurst, IL); Mills, Frederick E. (Elburn, IL)

    1987-01-01T23:59:59.000Z

    A current sensor for measuring the DC component of a beam of charged particles employs a superconducting pick-up loop probe, with twisted superconducting leads in combination with a Superconducting Quantum Interference Device (SQUID) detector. The pick-up probe is in the form of a single-turn loop, or a cylindrical toroid, through which the beam is directed and within which a first magnetic flux is excluded by the Meisner effect. The SQUID detector acts as a flux-to-voltage converter in providing a current to the pick-up loop so as to establish a second magnetic flux within the electrode which nulls out the first magnetic flux. A feedback voltage within the SQUID detector represents the beam current of the particles which transit the pick-up loop. Meisner effect currents prevent changes in the magnetic field within the toroidal pick-up loop and produce a current signal independent of the beam's cross-section and its position within the toroid, while the combination of superconducting elements provides current measurement sensitivites in the nano-ampere range.

  2. Covariant Spectator Theory of np scattering: Isoscalar interaction currents

    SciTech Connect (OSTI)

    Gross, Franz L. [JLAB

    2014-06-01T23:59:59.000Z

    Using the Covariant Spectator Theory (CST), one boson exchange (OBE) models have been found that give precision fits to low energy $np$ scattering and the deuteron binding energy. The boson-nucleon vertices used in these models contain a momentum dependence that requires a new class of interaction currents for use with electromagnetic interactions. Current conservation requires that these new interaction currents satisfy a two-body Ward-Takahashi (WT), and using principals of {\\it simplicity\\/} and {\\it picture independence\\/}, these currents can be uniquely determined. The results lead to general formulae for a two-body current that can be expressed in terms of relativistic $np$ wave functions, ${\\it \\Psi}$, and two convenient truncated wave functions, ${\\it \\Psi}^{(2)}$ and $\\widehat {\\it \\Psi}$, which contain all of the information needed for the explicit evaluation of the contributions from the interaction current. These three wave functions can be calculated from the CST bound or scattering state equations (and their off-shell extrapolations). A companion paper uses this formalism to evaluate the deuteron magnetic moment.

  3. Covariant Spectator Theory of np scattering: Isoscalar interaction currents

    E-Print Network [OSTI]

    Franz Gross

    2014-04-06T23:59:59.000Z

    Using the Covariant Spectator Theory (CST), one boson exchange (OBE) models have been found that give precision fits to low energy np scattering and the deuteron binding energy. The boson-nucleon vertices used in these models contain a momentum dependence that requires a new class of interaction currents for use with electromagnetic interactions. Current conservation requires that these new interaction currents satisfy a two-body Ward-Takahashi identity, and using principals of simplicity and picture independence, these currents can be uniquely determined. The results lead to general formulae for a two-body current that can be expressed in terms of relativistic np wave functions, Psi, and two convenient truncated wave functions, ${\\it \\Psi}^{(2)}$ and $\\widehat {\\it \\Psi}$, which contain all of the information needed for the explicit evaluation of the contributions from the interaction current. These three wave functions can be calculated from the CST bound or scattering state equations (and their off-shell extrapolations). A companion paper uses this formalism to evaluate the deuteron magnetic moment.

  4. Explosive plane-wave lens

    DOE Patents [OSTI]

    Marsh, S.P.

    1987-03-12T23:59:59.000Z

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

  5. Explosive plane-wave lens

    DOE Patents [OSTI]

    Marsh, S.P.

    1988-03-08T23:59:59.000Z

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

  6. HIGH ACCURACY BEAM CURRENT MONITOR SYSTEM FOR CEBAF'S EXPERIMENTAL HALL A *

    E-Print Network [OSTI]

    HIGH ACCURACY BEAM CURRENT MONITOR SYSTEM FOR CEBAF'S EXPERIMENTAL HALL A * J.-C. Denard , A. Saha CEBAF accelerator delivers continuous wave (CW) electron beams to three experimental Halls. In Hall A is described. 1 INTRODUCTION The CEBAF accelerator delivers continuous wave (CW) electron beams to three

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

    E-Print Network [OSTI]

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

    2011-09-30T23:59:59.000Z

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

  8. IR Hot Wave

    SciTech Connect (OSTI)

    Graham, T. B.

    2010-04-01T23:59:59.000Z

    The IR Hot Wave{trademark} furnace is a breakthrough heat treatment system for manufacturing metal components. Near-infrared (IR) radiant energy combines with IR convective heating for heat treating. Heat treatment is an essential process in the manufacture of most components. The controlled heating and cooling of a metal or metal alloy alters its physical, mechanical, and sometimes chemical properties without changing the object's shape. The IR Hot Wave{trademark} furnace offers the simplest, quickest, most efficient, and cost-effective heat treatment option for metals and metal alloys. Compared with other heat treatment alternatives, the IR Hot Wave{trademark} system: (1) is 3 to 15 times faster; (2) is 2 to 3 times more energy efficient; (3) is 20% to 50% more cost-effective; (4) has a {+-}1 C thermal profile compared to a {+-}10 C thermal profile for conventional gas furnaces; and (5) has a 25% to 50% smaller footprint.

  9. Piezoelectric wave motor

    DOE Patents [OSTI]

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

    2003-02-11T23:59:59.000Z

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

  10. Piezoelectric wave motor

    DOE Patents [OSTI]

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

    2001-07-17T23:59:59.000Z

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

  11. Standing wave compressor

    DOE Patents [OSTI]

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

    1991-01-01T23:59:59.000Z

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

  12. Gravitational wave astronomy - astronomy of the 21st century

    E-Print Network [OSTI]

    S. V. Dhurandhar

    2011-04-15T23:59:59.000Z

    An enigmatic prediction of Einstein's general theory of relativity is gravitational waves. With the observed decay in the orbit of the Hulse-Taylor binary pulsar agreeing within a fraction of a percent with the theoretically computed decay from Einstein's theory, the existence of gravitational waves was firmly established. Currently there is a worldwide effort to detect gravitational waves with interferometric gravitational wave observatories or detectors and several such detectors have been built or being built. The initial detectors have reached their design sensitivities and now the effort is on to construct advanced detectors which are expected to detect gravitational waves from astrophysical sources. The era of gravitational wave astronomy has arrived. This article describes the worldwide effort which includes the effort on the Indian front - the IndIGO project -, the principle underlying interferometric detectors both on ground and in space, the principal noise sources that plague such detectors, the astrophysical sources of gravitational waves that one expects to detect by these detectors and some glimpse of the data analysis methods involved in extracting the very weak gravitational wave signals from detector noise.

  13. An unstructured C-grid based method for 3-D global ocean dynamics: Free-surface formulations and tidal test cases

    E-Print Network [OSTI]

    Peltier, W. Richard

    and tidal test cases G.R. Stuhne *, W.R. Peltier Department of Physics, University of Toronto, 60 St. George rights reserved. 1. Introduction In a previous paper (Stuhne and Peltier, 2006, hereafter SP), we

  14. MHD wave propagation in the neighbourhood of a two-dimensional null point

    E-Print Network [OSTI]

    J. A. McLaughlin; A. W. Hood

    2007-12-11T23:59:59.000Z

    The nature of fast magnetoacoustic and Alfv\\'en waves is investigated in a zero $\\beta$ plasma. This gives an indication of wave propagation in the low $\\beta$ solar corona. It is found that for a two-dimensional null point, the fast wave is attracted to that point and the front of the wave slows down as it approaches the null point, causing the current density to accumulate there and rise rapidly. Ohmic dissipation will extract the energy in the wave at this point. This illustrates that null points play an important role in the rapid dissipation of fast magnetoacoustic waves and suggests the location where wave heating will occur in the corona. The Alfv\\'en wave behaves in a different manner in that the wave energy is dissipated along the separatrices. For Alfv\\'en waves that are decoupled from fast waves, the value of the plasma $\\beta$ is unimportant. However, the phenomenon of dissipating the majority of the wave energy at a specific place is a feature of both wave types.

  15. Adaptive multiconfigurational wave functions

    SciTech Connect (OSTI)

    Evangelista, Francesco A., E-mail: francesco.evangelista@emory.edu [Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322 (United States)

    2014-03-28T23:59:59.000Z

    A method is suggested to build simple multiconfigurational wave functions specified uniquely by an energy cutoff ?. These are constructed from a model space containing determinants with energy relative to that of the most stable determinant no greater than ?. The resulting ?-CI wave function is adaptive, being able to represent both single-reference and multireference electronic states. We also consider a more compact wave function parameterization (?+SD-CI), which is based on a small ?-CI reference and adds a selection of all the singly and doubly excited determinants generated from it. We report two heuristic algorithms to build ?-CI wave functions. The first is based on an approximate prescreening of the full configuration interaction space, while the second performs a breadth-first search coupled with pruning. The ?-CI and ?+SD-CI approaches are used to compute the dissociation curve of N{sub 2} and the potential energy curves for the first three singlet states of C{sub 2}. Special attention is paid to the issue of energy discontinuities caused by changes in the size of the ?-CI wave function along the potential energy curve. This problem is shown to be solvable by smoothing the matrix elements of the Hamiltonian. Our last example, involving the Cu{sub 2}O{sub 2}{sup 2+} core, illustrates an alternative use of the ?-CI method: as a tool to both estimate the multireference character of a wave function and to create a compact model space to be used in subsequent high-level multireference coupled cluster computations.

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

    E-Print Network [OSTI]

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

    2008-03-01T23:59:59.000Z

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

  17. Real-time Water Waves with Wave Particles

    E-Print Network [OSTI]

    Yuksel, Cem

    2010-10-12T23:59:59.000Z

    This dissertation describes the wave particles technique for simulating water surface waves and two way fluid-object interactions for real-time applications, such as video games. Water exists in various different forms in our environment...

  18. Structural health monitoring by ultrasonic guided waves

    E-Print Network [OSTI]

    Bartoli, Ivan

    2007-01-01T23:59:59.000Z

    E. (2005) “Modeling guided wave propagation with applicationMultiple Guided Ultrasonic Wave Features,” ASME Journal ofto-spar joints using guided waves and macro fiber composite

  19. Heat Waves, Global Warming, and Mitigation

    E-Print Network [OSTI]

    Carlson, Ann E.

    2008-01-01T23:59:59.000Z

    Heat Waves, Global Warming, and Mitigation Ann E. Carlson*II. HEAT WAVE DEFINITIONS .. A . HCHANGE AND HEAT WAVES .. CLIMATE III. IV. HEAT

  20. Heat Waves, Global Warming, and Mitigation

    E-Print Network [OSTI]

    Carlson, Ann E.

    2008-01-01T23:59:59.000Z

    Heat Waves, Global Warming, and Mitigation Ann E. Carlson*2008]HEAT WAVES, GLOBAL WARMING, AND MITIGATION 175 stroke2001). 2008]HEAT WAVES, GLOBAL WARMING, AND MITIGATION 177

  1. Propagation of seismic waves through liquefied soils

    E-Print Network [OSTI]

    Taiebat, Mahdi; Jeremic, Boris; Dafalias, Yannis; Kaynia, Amir; Cheng, Zhao

    2010-01-01T23:59:59.000Z

    the mechanisms of wave propagation and ARTICLE IN PRESS M.Numerical analysis Wave propagation Earthquake Liquefactionenergy during any wave propagation. This paper summarizes

  2. Wave refraction and wave energy on Cayo Arenas

    E-Print Network [OSTI]

    Walsh, Donald Eugene

    1962-01-01T23:59:59.000Z

    WAVE REFRACTION AND WAVE ENERGY ON CAYO ARENAS A Thesis By Donald E. Welsh Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... January 1962 Major Subject: Physical Oceanography WAVE REFRACTION AND WAVE ENERGY ON CAYO ARENAS A Thesis Donald E. Walsh Approved as to style and content by: Chairman of the Committee ead of Department ' / January 1962 ACKNOWLEDGMENTS...

  3. LIGO and the Search for Gravitational Waves

    SciTech Connect (OSTI)

    Robertson, Norna A.

    2006-10-16T23:59:59.000Z

    Gravitational waves, predicted to exist by Einstein's General Theory of Relativity but as yet undetected, are expected to be emitted during violent astrophysical events such as supernovae, black hole interactions and the coalescence of compact binary systems. Their detection and study should lead to a new branch of astronomy. However the experimental challenge is formidable: ground-based detection relies on sensing displacements of order 10{sup -18} m over a frequency range of tens of hertz to a few kHz. There is currently a large international effort to commission and operate long baseline interferometric detectors including those that comprise LIGO - the Laser Interferometer Gravitational-Wave Observatory - in the USA. In this talk I will give an introduction to the topic of gravitational wave detection and in particular review the status of the LIGO project which is currently taking data at its design sensitivity. I will also look to the future to consider planned improvements in sensitivity for such detectors, focusing on Advanced LIGO, the proposed upgrade to the LIGO project.

  4. Fault current limiter

    DOE Patents [OSTI]

    Darmann, Francis Anthony

    2013-10-08T23:59:59.000Z

    A fault current limiter (FCL) includes a series of high permeability posts for collectively define a core for the FCL. A DC coil, for the purposes of saturating a portion of the high permeability posts, surrounds the complete structure outside of an enclosure in the form of a vessel. The vessel contains a dielectric insulation medium. AC coils, for transporting AC current, are wound on insulating formers and electrically interconnected to each other in a manner such that the senses of the magnetic field produced by each AC coil in the corresponding high permeability core are opposing. There are insulation barriers between phases to improve dielectric withstand properties of the dielectric medium.

  5. Tides and Tidal Capture in post-Main Sequence Binaries: A Period Gap for Planets Around White Dwarfs

    E-Print Network [OSTI]

    Nordhaus, J; Ibgui, L; Goodman, J; Burrows, A

    2010-01-01T23:59:59.000Z

    The presence of a close, low-mass companion is thought to play a substantial and perhaps necessary role in shaping post-Asymptotic Giant Branch and Planetary Nebula outflows. During post-main-sequence evolution, radial expansion of the primary star, accompanied by intense winds, can significantly alter the binary orbit via tidal dissipation and mass loss. To investigate this, we couple stellar evolution models (from the zero-age main-sequence through the end of the post-main sequence) to a tidal evolution code. The binary's fate is determined by the initial masses of the primary and the companion, the initial orbit (taken to be circular), and the Reimer's mass-loss parameter. For a range of these parameters, we determine whether the orbit expands due to mass loss or decays due to tidal torques. Where a common envelope phase (CEP) ensues, we estimate the final orbital separation based on the energy required to unbind the envelope. These calculations predict a period gap for planetary companions to white dwarfs...

  6. Secular Sediment Waves, Channel Bed Waves, and Legacy Sediment

    E-Print Network [OSTI]

    James, L. Allan

    Secular Sediment Waves, Channel Bed Waves, and Legacy Sediment L. Allan James* Geography Department, University South Carolina Abstract The concept of sediment waves is reviewed and clarifications are proposed for nomenclature con- cerning vertical channel responses to large fluvial sediment fluxes over a period of a decade

  7. Water Waves and Integrability

    E-Print Network [OSTI]

    Rossen I. Ivanov

    2007-07-12T23:59:59.000Z

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

  8. Zonal flow and field generation by finite beta drift waves and kinetic drift-Alfven waves

    E-Print Network [OSTI]

    Rubloff, Gary W.

    Zonal flow and field generation by finite beta drift waves and kinetic drift-Alfve´n waves P. N magnetic fields by finite beta drift waves and kinetic drift-Alfve´n waves is presented. The analysis by electrostatic drift waves to finite beta drift waves and kinetic drift-Alfve´n waves. The drift wave driven

  9. Long Term Spectral Evolution of Tidal Disruption Candidates Selected by Strong Coronal Lines

    E-Print Network [OSTI]

    Yang, Chenwei; Ferland, Gary; Yuan, Weimin; Zhou, Hongyan; Jiang, Peng

    2013-01-01T23:59:59.000Z

    We present results of follow-up optical spectroscopic observations of seven rare, extreme coronal line emitting galaxies reported by Wang et al. (2012) with Multi-Mirror Telescope (MMT). Large variations in coronal lines are found in four objects, making them strong candidates of tidal disruption events (TDE). For the four TDE candidates, all the coronal lines with ionization status higher than [Fe VII] disappear within 5-9 years. The [Fe VII] faded by a factor of about five in one object (J0952+2143) within 4 years, whereas emerged in other two without them previously. A strong increment in the [O III] flux is observed, shifting the line ratios towards the loci of active galactic nucleus on the BPT diagrams. Surprisingly, we detect a non-canonical [O III]5007/[O III]4959 2 in two objects, indicating a large column density of O$^{2+}$ and thus probably optical thick gas. This also requires a very large ionization parameter and relatively soft ionizing spectral energy distribution (e.g. blackbody with $T < ...

  10. Transformative Wave Technologies Kent, Washington

    E-Print Network [OSTI]

    California at Davis, University of

    Transformative Wave Technologies Kent, Washington www.transformativewave.com #12;#12;North America are shifted to off peak times #12;#12;Transformative Wave Technologies www.transformativewave.com #12

  11. Current address: Samuel Johnson

    E-Print Network [OSTI]

    Johnson, Samuel

    CV: E-mail : Homepage: Current address: Samuel Johnson samuel.johnson@imperial.ac.uk www. #12;Submitted work 1. The meaning of niche: Cause or consequence of food-web structure?, S. Johnson, V learning, S. Johnson, J. Marro, and J.J. Torres, PLoS ONE 8(1): e50276 (2013) 3. Enhancing neural network

  12. Hydrogen Delivery- Current Technology

    Broader source: Energy.gov [DOE]

    Hydrogen is transported from the point of production to the point of use via pipeline, over the road in cryogenic liquid trucks or gaseous tube trailers, or by rail or barge. Read on to learn more about current hydrogen delivery and storage technologies.

  13. The Contribution of Environmental Siting and Permitting Requirements to the Cost of Energy for Wave Energy Devices

    SciTech Connect (OSTI)

    Copping, Andrea E.; Geerlofs, Simon H.; Hanna, Luke A.

    2014-06-30T23:59:59.000Z

    Responsible deployment of marine and hydrokinetic (MHK) devices in estuaries, coastal areas, and major rivers requires that biological resources and ecosystems be protected through siting and permitting (consenting) processes. Scoping appropriate deployment locations, collecting pre-installation (baseline) and post-installation data all add to the cost of developing MHK projects, and hence to the cost of energy. Under the direction of the U.S. Department of Energy, Pacific Northwest National Laboratory scientists have developed logic models that describe studies and processes for environmental siting and permitting. Each study and environmental permitting process has been assigned a cost derived from existing and proposed tidal, wave, and riverine MHK projects. Costs have been developed at the pilot scale and for commercial arrays for a surge wave energy converter

  14. Spherical waves r Legendre polynomials

    E-Print Network [OSTI]

    Berlin,Technische Universität

    1 Impedance · Spherical waves r er e e Impedance · Legendre polynomials P0(x) = 1 P1(x) = x P2(x · Spherical waves ­ Spherical Hankel functions hn (2)(kr)=jn(kr)-iyn(kr) Impedance · Spherical waves Order: 0 1 4 Circumferential And azimuthal: 0,0 1,1 3,2 #12;3 Impedance · Spherical waves ­ Arbitrary

  15. Wind and tidal response of a semi-enclosed bay, Bahía Concepción, Baja California

    E-Print Network [OSTI]

    Ponte, Aurélien L. S.

    2009-01-01T23:59:59.000Z

    Observed response to diurnal winds . . . . . 4.1Thermal wind balance . . . . . . . . . . . . . . . . . . . .level response to wind . . . . . . . . . . . . 4.3 Current

  16. Gravitational Waves from Coalescing Binary Black Holes: Theoretical and Experimental Challenges

    ScienceCinema (OSTI)

    None

    2011-10-06T23:59:59.000Z

    A network of ground-based interferometric gravitational wave detectors (LIGO/VIRGO/GEO/...) is currently taking data near its planned sensitivity. Coalescing black hole binaries are among the most promising, and most exciting, gravitational wave sources for these detectors. The talk will review the theoretical and experimental challenges that must be met in order to successfully detect gravitational waves from coalescing black hole binaries, and to be able to reliably measure the physical parameters of the source (masses, spins, ...).

  17. 2, 70177025, 2014 Freaque wave

    E-Print Network [OSTI]

    NHESSD 2, 7017­7025, 2014 Freaque wave occurrences in 2013 P. C. Liu Title Page Abstract to the corresponding final paper in NHESS if available. Brief Communication: Freaque wave occurrences in 2013 P. C. Liu­7025, 2014 Freaque wave occurrences in 2013 P. C. Liu Title Page Abstract Introduction Conclusions References

  18. 2014 Tube -1 STANDING WAVES

    E-Print Network [OSTI]

    Glashausser, Charles

    2014 Tube - 1 STANDING WAVES IN AN AIR COLUMN The objective of the experiment is: · To study the harmonic structure of standing waves in an air column. APPARATUS: Computer, FFTScope software, PC speaker, meterstick, sound tube apparatus, thermometer, microphone INTRODUCTION traveling wave of sinusoidal shape

  19. GENERATING ELECTRICITY USING OCEAN WAVES

    E-Print Network [OSTI]

    Bradbeer, Robin Sarah

    GENERATING ELECTRICITY USING OCEAN WAVES A RENEWABLE SOURCE OF ENERGY REPORT FOR THE HONG KONG ELECTRIC COMPANY LIMITED Dr L F Yeung Mr Paul Hodgson Dr Robin Bradbeer July 2007 #12;Ocean Waves and construction of equipment that could measure and log wave conditions and tide levels at Hoi Ha Wan. Prototypes

  20. Extreme wave impinging and overtopping

    E-Print Network [OSTI]

    Ryu, Yong Uk

    2009-06-02T23:59:59.000Z

    This investigates the velocity fields of a plunging breaking wave impinging on a structure through measurements in a two-dimensional wave tank. As the wave breaks and overtops the structure, so-called green water is generated. The flow becomes multi...

  1. Gas Explosion Characterization, Wave Propagation

    E-Print Network [OSTI]

    s & Dt^boooo^j Risø-R-525 Gas Explosion Characterization, Wave Propagation (Small-Scale Experiments EXPLOSION CHARACTERIZATION, WAVE PROPAGATION (Small-Scale Experiments) G.C. Larsen Abstract. A number characteristics 14 3.5. Characteristics of the primary pressure wave 21 3.6. Pressure propagation over a hard

  2. Study of Magnetohydrodynamic Surface Waves on Liquid Gallium

    SciTech Connect (OSTI)

    Hantao Ji; William Fox; David Pace; H.L. Rappaport

    2004-05-13T23:59:59.000Z

    Magnetohydrodynamic (MHD) surface waves on liquid gallium are studied theoretically and experimentally in the small magnetic Reynolds number limit. A linear dispersion relation is derived when a horizontal magnetic field and a horizontal electric current is imposed. No wave damping is found in the shallow liquid limit while waves always damp in the deep liquid limit with a magnetic field parallel to the propagation direction. When the magnetic field is weak, waves are weakly damped and the real part of the dispersion is unaffected, while in the opposite limit waves are strongly damped with shortened wavelengths. In a table-top experiment, planar MHD surface waves on liquid gallium are studied in detail in the regime of weak magnetic field and deep liquid. A non-invasive diagnostic accurately measures surface waves at multiple locations by reflecting an array of lasers off the surface onto a screen, which is recorded by an Intensified-CCD camera. The measured dispersion relation is consistent with the linear theory with a reduced surface tension likely due to surface oxidation. In excellent agreement with linear theory, it is observed that surface waves are damped only when a horizontal magnetic field is imposed parallel to the propagation direction. No damping is observed under a perpendicular magnetic field. The existence of strong wave damping even without magnetic field suggests the importance of the surface oxide layer. Implications to the liquid metal wall concept in fusion reactors, especially on the wave damping and a Rayleigh-Taylor instability when the Lorentz force is used to support liquid metal layer against gravity, are discussed.

  3. Electromagnetic WavesElectromagnetic Waves In this chapter we will review selected properties of electromagnetic waves since

    E-Print Network [OSTI]

    Rutledge, Steven

    Electromagnetic WavesElectromagnetic Waves In this chapter we will review selected properties of electromagnetic waves since radar involves the transmission, propagation and scattering of EM waves by various is the electrostatic force between two point charges. #12;Electromagnetic WavesElectromagnetic Waves Electric fields

  4. Introduction Modeling of large ocean waves Propagation speed Coherent wavetrains Near-shore wave dynamics Conclusions Tsunamis and ocean waves

    E-Print Network [OSTI]

    Craig, Walter

    Introduction Modeling of large ocean waves Propagation speed Coherent wavetrains Near-shore wave waves #12;Introduction Modeling of large ocean waves Propagation speed Coherent wavetrains NearMaster University Tsunamis and ocean waves #12;Introduction Modeling of large ocean waves Propagation speed Coherent

  5. Nonlinear phenomena of generation of longitudinal electric current by transversal electromagnetic field in plasmas

    E-Print Network [OSTI]

    Latyshev, A V

    2015-01-01T23:59:59.000Z

    The analysis of nonlinear interaction of transversal electromagnetic field with collisionless plasma is carried out. Formulas for calculation electric current in collisionless plasma with arbitrary degree of degeneration of electronic gas are deduced. It has appeared, that the nonlinearity account leads to occurrence of the longitudinal electric current directed along a wave vector. This second current is orthogonal to the known transversal current, received at the classical linear analysis.

  6. Aternating current photovoltaic building block

    DOE Patents [OSTI]

    Bower, Ward Issac; Thomas, Michael G.; Ruby, Douglas S.

    2004-06-15T23:59:59.000Z

    A modular apparatus for and method of alternating current photovoltaic power generation comprising via a photovoltaic module, generating power in the form of direct current; and converting direct current to alternating current and exporting power via one or more power conversion and transfer units attached to the module, each unit comprising a unitary housing extending a length or width of the module, which housing comprises: contact means for receiving direct current from the module; one or more direct current-to-alternating current inverters; an alternating current bus; and contact means for receiving alternating current from the one or more inverters.

  7. On the vertical structure of adiabatic wave forcing for the ocean circulation

    E-Print Network [OSTI]

    : wave-current coupling, radiation stresses, MARS3D, WAVEWATCH III Three-dimensional oceanic flows canOn the vertical structure of adiabatic wave forcing for the ocean circulation Part I: Theory submitted to Ocean Modelling October 5, 2010 hal-00523388,version2-5Oct2010 #12;can be developed. Keywords

  8. Dyadic Green's functions and guided surface waves for a surface conductivity model of graphene

    E-Print Network [OSTI]

    Hanson, George

    Dyadic Green's functions and guided surface waves for a surface conductivity model of graphene current in the presence of a surface conductivity model of graphene. The graphene is represented and transmission is presented, and surface wave propagation along graphene is studied via the poles

  9. Wave run-up on a high-energy dissipative beach Peter Ruggiero

    E-Print Network [OSTI]

    Wave run-up on a high-energy dissipative beach Peter Ruggiero Coastal and Marine Geology Program, U in foreshore beach morphology, wave run-up data collected along the central Oregon coast during February 1996 stand in contrast to run-up data currently available in the literature. During a single data run lasting

  10. Current Annualized Request

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy UsageAUDITVehiclesTankless orAChiefAppropriation FY 2012 FY 2013 FY 2014 Current

  11. System studies of rf current drive for MST

    SciTech Connect (OSTI)

    Anderson, J. K.; Burke, D. R.; Forest, C. B.; Goetz, J. A.; Hendries, E. R.; Seltzman, A. H.; Thomas, M. A. [Department of Physics, University of Wisconsin, Madison, WI (United States); Diem, S. [Oak Ridge National Laboratory, Oak Ridge TN (United States); Harvey, R. W. [CompX, Del Mar, CA (United States); Kaufman, M. C. [Department of Physics, University of Wisconsin, Madison, WI (United States); Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    2011-12-23T23:59:59.000Z

    Two rf schemes are being studied on the MST reversed field pinch for their potential in current profile control experiments. MHD modeling has shown that a substantial externally-driven off axis parallel current can improve stability of the dominant core tearing modes. A radially localized axisymmetric population of fast electrons has been observed by SXR emission during LH injection (100kW at 800MHz), and is consistent with CQL3D modeling which predicts a small driven current. Computational work suggests that doubling the input power will statistically improve the LH-induced SXR signal to background ratio, and that about 2MW of injected power (an order of magnitude increase) will drive enough current for stabilization of tearing modes. Additionally, a 1 MW 5.5 GHz electron Bernstein wave (EBW) experiment is under construction, which utilizes a very simple and compact antenna compatible with the demands of the RFP. EBW allows access to electron cyclotron heating and current drive in the overdense plasma. Coupling of the external electromagnetic wave to the EBW has been demonstrated, and initial tests at {approx}100kW power have produced a small, localized xray flux consistent with rf heating and high diffusivity of fast electrons. Computational work is currently underway to answer the very important questions of how much power is required, and what level of electron diffusivity is tolerable, to generate a consequential amount of EBW current.

  12. Circulation in the Columbia River estuary is influenced by tidal forcing, river discharge and wind stress. Through their interac-

    E-Print Network [OSTI]

    - board observations and data collected by underwater unmanned vehicles (AUVs) during a CMOP research. APPROACH Internal waves are underwater waves on subsurface density gra- dients. They move the surface very

  13. Spatiotemporal synchronization of drift waves in a magnetron sputtering plasma

    SciTech Connect (OSTI)

    Martines, E.; Zuin, M.; Cavazzana, R.; Antoni, V.; Serianni, G.; Spolaore, M.; Vianello, N. [Consorzio RFX, Padova (Italy); Adámek, J. [Institute of Plasma Physics AS CR, Prague (Czech Republic)

    2014-10-15T23:59:59.000Z

    A feedforward scheme is applied for drift waves control in a magnetized magnetron sputtering plasma. A system of driven electrodes collecting electron current in a limited region of the explored plasma is used to interact with unstable drift waves. Drift waves actually appear as electrostatic modes characterized by discrete wavelengths of the order of few centimeters and frequencies of about 100 kHz. The effect of external quasi-periodic, both in time and space, travelling perturbations is studied. Particular emphasis is given to the role played by the phase relation between the natural and the imposed fluctuations. It is observed that it is possible by means of localized electrodes, collecting currents which are negligible with respect to those flowing in the plasma, to transfer energy to one single mode and to reduce that associated to the others. Due to the weakness of the external action, only partial control has been achieved.

  14. Nonlinear Hysteretic Torsional Waves

    E-Print Network [OSTI]

    J. Cabaret; P. Béquin; G. Theocharis; V. Andreev; V. E. Gusev; V. Tournat

    2015-01-09T23:59:59.000Z

    We theoretically study and experimentally report the propagation of nonlinear hysteretic torsional pulses in a vertical granular chain made of cm-scale, self-hanged magnetic beads. As predicted by contact mechanics, the torsional coupling between two beads is found nonlinear hysteretic. This results in a nonlinear pulse distortion essentially different from the distortion predicted by classical nonlinearities, and in a complex dynamic response depending on the history of the wave particle angular velocity. Both are consistent with the predictions of purely hysteretic nonlinear elasticity and the Preisach-Mayergoyz hysteresis model, providing the opportunity to study the phenomenon of nonlinear dynamic hysteresis in the absence of other type of material nonlinearities. The proposed configuration reveals a plethora of interesting phenomena including giant amplitude-dependent attenuation, short term memory as well as dispersive properties. Thus, it could find interesting applications in nonlinear wave control devices such as strong amplitude-dependent filters.

  15. Nonlinear Hysteretic Torsional Waves

    E-Print Network [OSTI]

    Cabaret, J; Theocharis, G; Andreev, V; Gusev, V E; Tournat, V

    2015-01-01T23:59:59.000Z

    We theoretically study and experimentally report the propagation of nonlinear hysteretic torsional pulses in a vertical granular chain made of cm-scale, self-hanged magnetic beads. As predicted by contact mechanics, the torsional coupling between two beads is found nonlinear hysteretic. This results in a nonlinear pulse distortion essentially different from the distortion predicted by classical nonlinearities, and in a complex dynamic response depending on the history of the wave particle angular velocity. Both are consistent with the predictions of purely hysteretic nonlinear elasticity and the Preisach-Mayergoyz hysteresis model, providing the opportunity to study the phenomenon of nonlinear dynamic hysteresis in the absence of other type of material nonlinearities. The proposed configuration reveals a plethora of interesting phenomena including giant amplitude-dependent attenuation, short term memory as well as dispersive properties. Thus, it could find interesting applications in nonlinear wave control de...

  16. DNA waves and water

    E-Print Network [OSTI]

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

    2010-12-23T23:59:59.000Z

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

  17. Fractional Electromagnetic Waves

    E-Print Network [OSTI]

    J. F. Gómez; J. J. Rosales; J. J. Bernal; V. I. Tkach; M. Guía

    2011-08-31T23:59:59.000Z

    In the present work we consider the electromagnetic wave equation in terms of the fractional derivative of the Caputo type. The order of the derivative being considered is 0 <\\gamma<1. A new parameter \\sigma, is introduced which characterizes the existence of the fractional components in the system. We analyze the fractional derivative with respect to time and space, for \\gamma = 1 and \\gamma = 1/2 cases.

  18. Gravitational wave astronomy and cosmology

    E-Print Network [OSTI]

    Scott A. Hughes

    2014-05-02T23:59:59.000Z

    The first direct observation of gravitational waves' action upon matter has recently been reported by the BICEP2 experiment. Advanced ground-based gravitational-wave detectors are being installed. They will soon be commissioned, and then begin searches for high-frequency gravitational waves at a sensitivity level that is widely expected to reach events involving compact objects like stellar mass black holes and neutron stars. Pulsar timing arrays continue to improve the bounds on gravitational waves at nanohertz frequencies, and may detect a signal on roughly the same timescale as ground-based detectors. The science case for space-based interferometers targeting millihertz sources is very strong. The decade of gravitational-wave discovery is poised to begin. In this writeup of a talk given at the 2013 TAUP conference, we will briefly review the physics of gravitational waves and gravitational-wave detectors, and then discuss the promise of these measurements for making cosmological measurements in the near future.

  19. Surface Wave Enhanced Turbulence as an important source energy

    E-Print Network [OSTI]

    ) Pulling by wind stress & surface waves 9/15/2006 4 Heating Cooling Heating Cooling CoolingHeating . . Wind) Surface heating/cooling cannot maintain THC observed in the oceans. Sandstrom Theorem and the new debate 3 balance in the oceans Geostrophic Currents Ekman Drift Freshwater Flux 0.05 KE GPE Mean State Geothermal

  20. Current meter data report, September 1980 - December 1980: mooring OTEC-HB

    SciTech Connect (OSTI)

    Roman, T M; Wang, D P

    1981-03-01T23:59:59.000Z

    Data tapes contained current meter records from instrumented mooring OTEC-HB near the OTEC-1 site approximately 14 nautical miles northwest of Keahole Point, Island of Hawaii. Deployed in 1345 m of water, the mooring had five Aanderaa RCM-5 current meters, one at each of the following depths: 47 m, 70m, 99m, 154m, and 829 m. Raw data consisted of east-west (U) velocity, north-south (V) velocity, temperature (T), and pressure (P) time series from September 23, 1980, through December 20, 1980, with a recording interval of 15 min. The series (U, V, T) were filtered into various frequency domains, thereby removing very high frequencies and separating tidal oscillations from very low frequencies. Spectral analyses were performed on the nontidal U and V time series.

  1. CONSTRAINTS ON THE LIFETIMES OF DISKS RESULTING FROM TIDALLY DESTROYED ROCKY PLANETARY BODIES

    SciTech Connect (OSTI)

    Girven, J.; Gaensicke, B. T.; Marsh, T. R. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Brinkworth, C. S.; Hoard, D. W. [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Farihi, J. [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Koester, D., E-mail: j.m.girven@warwick.ac.uk [Institut fuer Theoretische Physik und Astrophysik, University of Kiel, 24098 Kiel (Germany)

    2012-04-20T23:59:59.000Z

    Spitzer IRAC observations of 15 metal-polluted white dwarfs reveal infrared excesses in the spectral energy distributions of HE 0110-5630, GD 61, and HE 1349-2305. All three of these stars have helium-dominated atmospheres, and their infrared emissions are consistent with warm dust produced by the tidal destruction of (minor) planetary bodies. This study brings the number of metal-polluted, helium and hydrogen atmosphere white dwarfs surveyed with IRAC to 53 and 38, respectively. It also nearly doubles the number of metal-polluted helium-rich white dwarfs found to have closely orbiting dust by Spitzer. From the increased statistics for both atmospheric types with circumstellar dust, we derive a typical disk lifetime of log [t{sub disk}(yr)] = 5.6 {+-} 1.1 (ranging from 3 Multiplication-Sign 10{sup 4} to 5 Multiplication-Sign 10{sup 6} yr). This assumes a relatively constant rate of accretion over the timescale where dust persists, which is uncertain. We find that the fraction of highly metal-polluted helium-rich white dwarfs that have an infrared excess detected by Spitzer is only 23%, compared to 48% for metal-polluted hydrogen-rich white dwarfs, and we conclude from this difference that the typical lifetime of dusty disks is somewhat shorter than the diffusion timescales of helium-rich white dwarf. We also find evidence for higher time-averaged accretion rates onto helium-rich stars compared to the instantaneous accretion rates onto hydrogen-rich stars; this is an indication that our picture of evolved star-planetary system interactions is incomplete. We discuss some speculative scenarios that can explain the observations.

  2. Ice shelf-ocean interactions in a general circulation model : melt-rate modulation due to mean flow and tidal currents

    E-Print Network [OSTI]

    Dansereau, Véronique

    2012-01-01T23:59:59.000Z

    Interactions between the ocean circulation in sub-ice shelf cavities and the overlying ice shelf have received considerable attention in the context of observed changes in flow speeds of marine ice sheets around Antarctica. ...

  3. Estuarine Conditions and Water Exchange in Fjords of Prince William Sound, Alaska

    E-Print Network [OSTI]

    Gay, Shelton Mann

    2014-01-09T23:59:59.000Z

    atypically high FWC values due to subsurface freshening. The currents at Simpson Bay reveal a complex flow structure forced by tides interacting with bathymetry and moderated by stratification, tidal volume flux, internal waves and winds. Baroclinic...

  4. Current Testbed Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phases onOrganization FY 2012 FY 2013 FY 2014|Current Test Procedure

  5. Current Transmission Rates

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phases onOrganization FY 2012 FY 2013 FY 2014|Current Test

  6. Fizeau interferometer for measurement of plasma electron current

    SciTech Connect (OSTI)

    Brower, D.L.; Ding, W.X.; Deng, B.H.; Mahdavi, M.A.; Mirnov, V.; Prager, S.C. [Electrical Engineering Department, University of California, Los Angeles, Los Angeles, California 90095 (United States); General Atomics, San Diego, California 92121 (United States); Physics Department, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

    2004-10-01T23:59:59.000Z

    A high-resolution, vertically viewing far-infrared polarimeter-interferometer system is currently used on the Madison symmetric torus (MST) reversed-field pinch (RFP) to measure the plasma electron density and toroidal current density via Faraday rotation. In this article, we propose a scheme to measure the well-known Fizeau effect, whereby through modest modification of the existing apparatus, the line-integrated poloidal current density can also be directly measured. This parameter is important, since the RFP toroidal magnetic field is largely determined by currents flowing within the plasma. The Fizeau effect is a phase shift of an electromagnetic wave associated with movement of a dielectric medium. This motion can be related directly to the plasma electron current. Determining the Fizeau effect involves measurement of the phase shift between two collinear, orthogonally polarized, counterpropagating laser beams. Estimates indicate a phase shift of {approx}2 deg. is expected for typical MST parameters, well within the existing system resolution.

  7. Measuring ocean waves from space; Proceedings of the Symposium, Johns Hopkins University, Laurel, MD, Apr. 15-17, 1986

    SciTech Connect (OSTI)

    Beal, R.C.

    1987-03-01T23:59:59.000Z

    Papers are presented on ocean-wave prediction; the quasi-universal form of the spectra of wind-generated gravity waves at different stages of their development; the limitations of the spectral measurements and observations of the group structure of surface waves; the effect of swell on the growth of wind wave; operational wave forecasting; ocean-wave models, and seakeeping using directional wave spectra. Consideration is given to microwave measurements of the ocean-wave directional spectra; SIR research; estimating wave energy spectra from SAR imagery, with the radar ocean-wave spectrometer, and SIR-B; the wave-measurement capabilities of the surface contour radar and the airborne oceanographic lidar; and SIR-B ocean-wave enhancement with fast-Fourier transform techniques. Topics discussed include wave-current interaction; the design and applicability of Spectrasat; the need for a global wave monitoring system; the age and source of ocean swell observed in Hurricane Josephine; and the use of satellite technology for insulin treatment.

  8. Method and apparatus for actively controlling a micro-scale flexural plate wave device

    DOE Patents [OSTI]

    Dohner, Jeffrey L. (Albuquerque, NM)

    2001-01-01T23:59:59.000Z

    An actively controlled flexural plate wave device provides a micro-scale pump. A method of actively controlling a flexural plate wave device produces traveling waves in the device by coordinating the interaction of a magnetic field with actively controlled currents. An actively-controlled flexural plate wave device can be placed in a fluid channel and adapted for use as a micro-scale fluid pump to cool or drive micro-scale systems, for example, micro-chips, micro-electrical-mechanical devices, micro-fluid circuits, or micro-scale chemical analysis devices.

  9. Wave Propagation in Jointed Geologic Media

    SciTech Connect (OSTI)

    Antoun, T

    2009-12-17T23:59:59.000Z

    Predictive modeling capabilities for wave propagation in a jointed geologic media remain a modern day scientific frontier. In part this is due to a lack of comprehensive understanding of the complex physical processes associated with the transient response of geologic material, and in part it is due to numerical challenges that prohibit accurate representation of the heterogeneities that influence the material response. Constitutive models whose properties are determined from laboratory experiments on intact samples have been shown to over-predict the free field environment in large scale field experiments. Current methodologies for deriving in situ properties from laboratory measured properties are based on empirical equations derived for static geomechanical applications involving loads of lower intensity and much longer durations than those encountered in applications of interest involving wave propagation. These methodologies are not validated for dynamic applications, and they do not account for anisotropic behavior stemming from direcitonal effects associated with the orientation of joint sets in realistic geologies. Recent advances in modeling capabilities coupled with modern high performance computing platforms enable physics-based simulations of jointed geologic media with unprecedented details, offering a prospect for significant advances in the state of the art. This report provides a brief overview of these modern computational approaches, discusses their advantages and limitations, and attempts to formulate an integrated framework leading to the development of predictive modeling capabilities for wave propagation in jointed and fractured geologic materials.

  10. Journal of Coastal Research, Special Issue 50, 2007 Journal of Coastal Research SI 50 pg -pg ICS2007 (Proceedings) Australia ISSN

    E-Print Network [OSTI]

    accelerate through the narrow, erosion-resistant rocky strait spanned by the Golden Gate Bridge, forming one. During peak flow tidal currents approach 3 m/s at the Golden Gate, a 1 km wide entrance that connects San radially. ADDITIONAL INDEX WORDS: Sand waves, Tidal delta, Littoral, Sediment transport THE GOLDEN GATE

  11. NOAA Great Lakes Environmental Research Laboratory, 4840 South State Road, Ann Arbor, MI 48108. Email: jia.wang@noaa.gov Jia Wang and Haoguo Hu

    E-Print Network [OSTI]

    , JGR). It is coupled ice dynamic and thermodynamic model (Hibler 1980, MWR) to the Princeton Ocean Model (POM) with two improvements: a) wave mixing effect and b) tidal mixing. Since the tidal current. Email: jia.wang@noaa.gov Jia Wang and Haoguo Hu A modeling study of sea ice and plankton in the Bering

  12. The Effect of Tidal Inflation Instability on the Mass and Dynamical Evolution of Extrasolar Planets with Ultra-Short Periods

    E-Print Network [OSTI]

    Pin-Gao Gu; Doug Lin; Peter Bodenheimer

    2003-03-17T23:59:59.000Z

    We investigate the possibility of substantial inflation of short-period Jupiter-mass planets, as a result of their internal tidal dissipation associated with the synchronization and circularization of their orbits. We employ the simplest prescription based on an equilibrium model with a constant lag angle for all components of the tide. We show that for young Jupiter-mass planets, with a period less than 3 days, an initial radius about 2 Jupiter radii, and an orbital eccentricity greater than 0.2, the energy dissipated during the circularization of their orbits is sufficiently intense and protracted to inflate their sizes up to their Roche radii.

  13. Spin waves in the (

    SciTech Connect (OSTI)

    Lipscombe, O. J. [University of Tennessee, Knoxville (UTK); Chen, G. F. [The Institute of Physics, Chinese Academy of Sciences; Fang, Chen [Purdue University; Perring, T. G. [ISIS Facility, Rutherford Appleton Laboratory; Abernathy, Douglas L [ORNL; Christianson, Andrew D [ORNL; Egami, Takeshi [ORNL; Wang, Nanlin [The Institute of Physics, Chinese Academy of Sciences; Hu, Jiangping [Purdue University and Chinese Academy of Sciences; Dai, Pengcheng [University of Tennessee, Knoxville (UTK)

    2011-01-01T23:59:59.000Z

    We use neutron scattering to show that spin waves in the iron chalcogenide Fe{sub 1.05}Te display novel dispersion clearly different from both the first principles density functional calculations and recent observations in the related iron pnictide CaFe{sub 2}As{sub 2}. By fitting to a Heisenberg Hamiltonian, we find that although the nearest-neighbor exchange couplings in the two systems are quite different, their next-nearest-neighbor (NNN) couplings are similar. This suggests that superconductivity in the pnictides and chalcogenides share a common magnetic origin that is intimately associated with the NNN magnetic coupling between the irons.

  14. Gravity Waves in the Sun

    E-Print Network [OSTI]

    Tamara M. Rogers; Gary A. Glatzmaier

    2005-08-25T23:59:59.000Z

    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.

  15. Quasi-Optical Propagation of an EC Gaussian Beam, Absorption and Current Drive in Tokamaks

    SciTech Connect (OSTI)

    Farina, Daniela [Istituto di Fisica del Plasma, Consiglio Nazionale delle Ricerche, EURATOM-ENEA-CNR Association, Milan (Italy)

    2006-11-30T23:59:59.000Z

    The issue of quasi-optical propagation of a Gaussian beam of electron cyclotron waves, and of the power absorption and driven current is reviewed for the case of a general tokamak equilibrium. The propagation of a general astigmatic Gaussian beam is described in terms of a set of quasi-optical rays which describe diffraction effects, within the framework of the complex eikonal approach. The absorbed power and the driven current density are computed along each ray solving the fully relativistic dispersion relation for electron cyclotron wave and by means of the neoclassical response function for the current. Results obtained with the new code GRAY in ITER are presented.

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

    SciTech Connect (OSTI)

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

    2014-03-21T23:59:59.000Z

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

  17. Wave Decay in MHD Turbulence

    E-Print Network [OSTI]

    Andrey Beresnyak; Alex Lazarian

    2008-05-06T23:59:59.000Z

    We present a model for nonlinear decay of the weak wave in three-dimensional incompressible magnetohydrodynamic (MHD) turbulence. We show that the decay rate is different for parallel and perpendicular waves. We provide a general formula for arbitrarily directed waves and discuss particular limiting cases known in the literature. We test our predictions with direct numerical simulations of wave decay in three-dimensional MHD turbulence, and discuss the influence of turbulent damping on the development of linear instabilities in the interstellar medium and on other important astrophysical processes.

  18. A Reconsideration of Matter Waves

    E-Print Network [OSTI]

    Roger Ellman

    2005-05-16T23:59:59.000Z

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

  19. Oscillatory nonohomic current drive for maintaining a plasma current

    DOE Patents [OSTI]

    Fisch, N.J.

    1984-01-01T23:59:59.000Z

    Apparatus and methods are described for maintaining a plasma current with an oscillatory nonohmic current drive. Each cycle of operation has a generation period in which current driving energy is applied to the plasma, and a relaxation period in which current driving energy is removed. Plasma parameters, such as plasma temperature or plasma average ionic charge state, are modified during the generation period so as to oscillate plasma resistivity in synchronism with the application of current driving energy. The invention improves overall current drive efficiencies.

  20. MHD simulation of RF current drive in MST

    SciTech Connect (OSTI)

    Hendries, E. R.; Anderson, J. K.; Forest, C. B.; Reusch, J. A.; Seltzman, A. H.; Sovinec, C. R. [University of Wisconsin, Madison WI (United States); Diem, S. [Oak Ridge National Laboratory, Oak Ridge TN (United States); Harvey, R. W. [CompX, Del Mar, CA (United States)

    2014-02-12T23:59:59.000Z

    Auxiliary heating and current drive using RF waves such as the electron Bernstein wave (EBW) promises to advance the performance of the reversed field pinch (RFP). In previous computational work [1], a hypothetical edge-localized current drive is shown to suppress the tearing activity which governs the macroscopic transport properties of the RFP. The ideal conditions for tearing stabilization include a reduced toroidal induction, and precise width and radial position of the Gaussian-shaped external current drive. In support of the EBW experiment on the Madison Symmetric Torus, an integrated modeling scheme now incorporates ray tracing and Fokker-Plank predictions of auxiliary current into single fluid MHD. Simulations at low Lundquist number (S ? 10{sup 4}) generally agree with the previous work; significantly more burdensome simulations at MST-like Lundquist number (S ? 3×10{sup 6}) show unexpected results. The effect on nonlinearly saturated current profile by a particular RF-driven external force decreases in magnitude and widens considerably as the Lundquist number increases toward experimental values. Simulations reproduce the periodic current profile relaxation events observed in experiment (sawteeth) in the absence of current profile control. Reduction of the tearing mode amplitudes is still observable; however, reduction is limited to periods between the large bursts of magnetic activity at each sawtooth. The sawtoothing pattern persists with up to 10 MW of externally applied RF power. Periods with prolonged low tearing amplitude are predicted with a combination of external current drive and a reduced toroidal loop voltage, consistent with previous conclusions. Finally, the resistivity profile is observed to have a strong effect on the optimal externally driven current profile for mode stabilization.

  1. Topological horseshoes in travelling waves of discretized nonlinear wave equations

    SciTech Connect (OSTI)

    Chen, Yi-Chiuan, E-mail: YCChen@math.sinica.edu.tw [Institute of Mathematics, Academia Sinica, Taipei 10617, Taiwan (China)] [Institute of Mathematics, Academia Sinica, Taipei 10617, Taiwan (China); Chen, Shyan-Shiou, E-mail: sschen@ntnu.edu.tw [Department of Mathematics, National Taiwan Normal University, Taipei 11677, Taiwan (China)] [Department of Mathematics, National Taiwan Normal University, Taipei 11677, Taiwan (China); Yuan, Juan-Ming, E-mail: jmyuan@pu.edu.tw [Department of Financial and Computational Mathematics, Providence University, Shalu, Taichung 43301, Taiwan (China)] [Department of Financial and Computational Mathematics, Providence University, Shalu, Taichung 43301, Taiwan (China)

    2014-04-15T23:59:59.000Z

    Applying the concept of anti-integrable limit to coupled map lattices originated from space-time discretized nonlinear wave equations, we show that there exist topological horseshoes in the phase space formed by the initial states of travelling wave solutions. In particular, the coupled map lattices display spatio-temporal chaos on the horseshoes.

  2. Discrete wave turbulence of rotational capillary water waves

    E-Print Network [OSTI]

    Adrian Constantin; Elena Kartashova; Erik Wahlén

    2010-05-12T23:59:59.000Z

    We study the discrete wave turbulent regime of capillary water waves with constant non-zero vorticity. The explicit Hamiltonian formulation and the corresponding coupling coefficient are obtained. We also present the construction and investigation of resonance clustering. Some physical implications of the obtained results are discussed.

  3. Modeling a nonperturbative spinor vacuum interacting with a strong gravitational wave

    E-Print Network [OSTI]

    Vladimir Dzhunushaliev; Vladimir Folomeev

    2015-03-15T23:59:59.000Z

    We consider the propagation of strong gravitational waves interacting with a nonperturbative vacuum of spinor fields. To described the latter, we suggest an approximate model. The corresponding Einstein equation has the form of the Schr\\"odinger equation. Its gravitational-wave solution is analogous to the solution of the Schr\\"odinger equation for an electron moving in a periodic potential. The general solution for the periodic gravitational waves is found. The analog of the Kronig-Penney model for gravitational waves is considered. It is shown that the suggested gravitational-wave model permits the existence of weak electric charge and current densities concomitant with the gravitational wave. Based on this observation, a possible experimental verification of the model is suggested.

  4. Modeling a nonperturbative spinor vacuum interacting with a strong gravitational wave

    E-Print Network [OSTI]

    Dzhunushaliev, Vladimir

    2015-01-01T23:59:59.000Z

    We consider the propagation of strong gravitational waves interacting with a nonperturbative vacuum of spinor fields. To described the latter, we suggest an approximate model. The corresponding Einstein equation has the form of the Schr\\"odinger equation. Its gravitational-wave solution is analogous to the solution of the Schr\\"odinger equation for an electron moving in a periodic potential. The general solution for the periodic gravitational waves is found. The analog of the Kronig-Penney model for gravitational waves is considered. It is shown that the suggested gravitational-wave model permits the existence of weak electric charge and current densities concomitant with the gravitational wave. Based on this observation, a possible experimental verification of the model is suggested.

  5. Mode conversion and absorption of fast waves at high ion cyclotron harmonics in inhomogeneous magnetic fields

    SciTech Connect (OSTI)

    Cho, Suwon, E-mail: swcho@kgu.ac.kr [Department of Physics, Kyonggi University, Suwon, Kyonggi-Do 443-760 (Korea, Republic of)] [Department of Physics, Kyonggi University, Suwon, Kyonggi-Do 443-760 (Korea, Republic of); Kwak, Jong-Gu [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of)] [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of)

    2014-04-15T23:59:59.000Z

    The propagation and absorption of high harmonic fast waves is of interest for non-inductive current drives in fusion experiments. The fast wave can be coupled with the ion Bernstein wave that propagates in the high magnetic field side of an ion cyclotron harmonic resonance layer. This coupling and the absorption are analyzed using the hot plasma dispersion relation and a wave equation that was converted from an approximate dispersion relation for the case where ?{sub i}=k{sub ?}{sup 2}?{sub i}{sup 2}/2?1 (where k{sub ?} is the perpendicular wave number and ?{sub i} is the ion Larmor radius). It is found that both reflection and conversion may occur near the harmonic resonance layer but that they decrease rapidly, giving rise to a sharp increase in the absorption as the parallel wave number increases.

  6. Laboratory Studies of Nonlinear and Breaking Surface Waves

    E-Print Network [OSTI]

    Drazen, David

    2006-01-01T23:59:59.000Z

    A. Breaking-wave generation . . . . . . . . . . . . . . . .of the wave tank. . . . . . . . . . . . . . . . . . . .On steep gravity waves meeting a vertical wall: a triple

  7. Circulating current battery heater

    DOE Patents [OSTI]

    Ashtiani, Cyrus N. (West Bloomfield, MI); Stuart, Thomas A. (Toledo, OH)

    2001-01-01T23:59:59.000Z

    A circuit for heating energy storage devices such as batteries is provided. The circuit includes a pair of switches connected in a half-bridge configuration. Unidirectional current conduction devices are connected in parallel with each switch. A series resonant element for storing energy is connected from the energy storage device to the pair of switches. An energy storage device for intermediate storage of energy is connected in a loop with the series resonant element and one of the switches. The energy storage device which is being heated is connected in a loop with the series resonant element and the other switch. Energy from the heated energy storage device is transferred to the switched network and then recirculated back to the battery. The flow of energy through the battery causes internal power dissipation due to electrical to chemical conversion inefficiencies. The dissipated power causes the internal temperature of the battery to increase. Higher internal temperatures expand the cold temperature operating range and energy capacity utilization of the battery. As disclosed, either fixed frequency or variable frequency modulation schemes may be used to control the network.

  8. Mon. Not. R. Astron. Soc. 391, 237245 (2008) doi:10.1111/j.1365-2966.2008.13868.x Tidal heating of terrestrial extrasolar planets and implications for their

    E-Print Network [OSTI]

    Barnes, Rory

    these issues, we model the tidal heating and evolution of hypothetical extrasolar terrestrial planets, Greenberg & Barnes 2008b). If such a planet is on an eccentric orbit, the dissipation of tidal energy within extrasolar planets are observed to be larger than theoretical modelling predicts (e.g. Bodenheimer, E

  9. Wave Evolution On the Evolution of Curvelets

    E-Print Network [OSTI]

    Smith, Hart F.

    Curvelets Wave Evolution On the Evolution of Curvelets by the Wave Equation Hart F. Smith of Curvelets by the Wave Equation #12;Curvelets Wave Evolution Curvelets and the Second Dyadic Decomposition Curvelets A curvelet frame {} is a wave packet frame on L2(R2) based on second dyadic decomposition. f

  10. Wave Mechanics and the Fifth Dimension

    E-Print Network [OSTI]

    Paul S. Wesson; James M. Overduin

    2013-01-28T23:59:59.000Z

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

  11. The fundamental properties of current controlled current source amplifiers

    E-Print Network [OSTI]

    Terry, Michael Buford

    1978-01-01T23:59:59.000Z

    The thesis studies the fundamental properties of current controlled current source (CCCS) amplifiers for use in a wide bandwidth voltage gain application. Theoretical expressions are derived which describe the p'erformance of the CCCS in terms of circuit... of this research was to conduct a theoretical and experimental study of the fundamental properties of Current Controlled Current Source (CCCS) amplifiers. Of particular interest was the bandwidth independence on the closed loop voltage gain of the CCCS used...

  12. Stray current interference control for HVDC earth currents

    SciTech Connect (OSTI)

    Fitzgerald, J.H. III [PSG Corrosion Engineering/Corrpro Cos., Detroit, MI (United States); Kroon, D.H. [Corrpro Companies Inc., Spring, TX (United States)

    1995-06-01T23:59:59.000Z

    High-voltage direct current (HVDC) transmission lines exist around the world, with several in the US. When one conductor must be taken out of operation (in case of emergency), the earth may be used as an alternate conductor. The earth current may be accumulated on and discharged from underground metallic structures that cross the voltage gradient created by the current. Test results on two lines showed that stray current interference is not a major problem if mitigated properly.

  13. Experimental studies of irregular water wave component interactions with comparisons to the hybrid wave model

    E-Print Network [OSTI]

    Longridge, Jonathon Kent

    1993-01-01T23:59:59.000Z

    computed by Wheeler Stretching and Linear Extrapolation modifications to Linear Random Wave Theory and the Hybrid Wave Model. Extreme wave acceleration fields arc compared with Hybrid Wave Model acceleration fields only. Comparisons between measurements...

  14. An Evidence-Based Evaluation of the Cumulative Effects of Tidal Freshwater and Estuarine Ecosystem Restoration on Endangered Juvenile Salmon in the Columbia River: Final Report

    SciTech Connect (OSTI)

    Diefenderfer, Heida L.; Johnson, Gary E.; Thom, Ronald M.; Borde, Amy B.; Woodley, Christa M.; Weitkamp, Laurie A.; Buenau, Kate E.; Kropp, Roy K.

    2013-12-01T23:59:59.000Z

    The listing of 13 salmon and steelhead stocks in the Columbia River basin (hereafter collectively referred to as “salmon”) under the Endangered Species Act of 1973, as amended, has stimulated tidal wetland restoration in the lower 235 kilometers of the Columbia River and estuary for juvenile salmon habitat functions. The purpose of the research reported herein was to evaluate the effect on listed salmon of the restoration effort currently being conducted under the auspices of the federal Columbia Estuary Ecosystem Restoration Program (CEERP). Linking changes in the quality and landscape pattern of tidal wetlands in the lower Columbia River and estuary (LCRE) to salmon recovery is a complex problem because of the characteristics of the ecosystem, the salmon, the restoration actions, and available sampling technologies. Therefore, we designed an evidence-based approach to develop, synthesize, and evaluate information to determine early-stage (~10 years) outcomes of the CEERP. We developed an ecosystem conceptual model and from that, a primary hypothesis that habitat restoration activities in the LCRE have a cumulative beneficial effect on juvenile salmon. There are two necessary conditions of the hypothesis: • habitat-based indicators of ecosystem controlling factors, processes, and structures show positive effects from restoration actions, and • fish-based indicators of ecosystem processes and functions show positive effects from restoration actions and habitats undergoing restoration. Our evidence-based approach to evaluate the primary hypothesis incorporated seven lines of evidence, most of which are drawn from the LCRE. The lines of evidence are spatial and temporal synergies, cumulative net ecosystem improvement, estuary-wide meta-analysis, offsite benefits to juvenile salmon, landscape condition evaluation, and evidence-based scoring of global literature. The general methods we used to develop information for the lines of evidence included field measurements, data analyses, modeling, meta-analysis, and reanalysis of previously collected data sets. We identified a set of 12 ancillary hypotheses regarding habitat and salmon response. Each ancillary hypothesis states that the response metric will trend toward conditions at relatively undisturbed reference sites. We synthesized the evidence for and against the two necessary conditions by using eleven causal criteria: strength, consistency, specificity, temporality, biological gradient, plausibility, coherence, experiment, analogy, complete exposure pathway, and predictive performance. Our final evaluation included cumulative effects assessment because restoration is occurring at multiple sites and the collective effect is important to salmon recovery. We concluded that all five lines of evidence from the LCRE indicated positive habitat-based and fish-based responses to the restoration performed under the CEERP, although tide gate replacements on small sloughs were an exception. Our analyses suggested that hydrologic reconnections restore access for fish to move into a site to find prey produced there. Reconnections also restore the potential for the flux of prey from the site to the main stem river, where our data show that they are consumed by salmon. We infer that LCRE ecosystem restoration supports increased juvenile salmon growth and enhanced fitness (condition), thereby potentially improving survival rates during the early ocean stage.

  15. Pumping single-file colloids: Absence of current reversal

    E-Print Network [OSTI]

    Debasish Chaudhuri; Archishman Raju; Abhishek Dhar

    2014-09-24T23:59:59.000Z

    We consider the single-file motion of colloidal particles interacting via short-ranged repulsion and placed in a traveling wave potential, that varies periodically in time and space. Under suitable driving conditions, a directed time-averaged flow of colloids is generated. We obtain analytic results for the model using a perturbative approach to solve the Fokker-Planck equations. The predictions show good agreement with numerical simulations. We find peaks in the time-averaged directed current as a function of driving frequency, wavelength and particle density and discuss possible experimental realizations. Surprisingly, unlike a closely related exclusion dynamics on a lattice, the directed current in the present model does not show current reversal with density. A linear response formula relating current response to equilibrium correlations is also proposed.

  16. MHK Projects/Shelter Island Tidal Energy Project | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat JumpIncMAKGalway Bay IE < MHK Project CitySantona WaveSeatricityCity

  17. Creating Wave-Focusing Materials

    E-Print Network [OSTI]

    A. G. Ramm

    2008-05-16T23:59:59.000Z

    Basic ideas for creating wave-focusing materials by injecting small particles in a given material are described. The number of small particles to be injected around any point is calculated. Inverse scattering problem with fixed wavenumber and fixed incident direction of the plane acoustic wave is formulated and solved.

  18. Colliding axisymmetric pp-waves

    E-Print Network [OSTI]

    B. V. Ivanov

    1997-10-21T23:59:59.000Z

    An exact solution is found describing the collision of axisymmetric pp-waves with M=0. They are impulsive in character and their coordinate singularities become point curvature singularities at the boundaries of the interaction region. The solution is conformally flat. Concrete examples are given, involving an ultrarelativistic black hole against a burst of pure radiation or two colliding beam- like waves.

  19. Momentum Imparted by Gravitational Waves

    E-Print Network [OSTI]

    M. Sharif

    2003-04-04T23:59:59.000Z

    We calculate momentum imparted by colliding gravitational waves in a closed Friedmann Robertson-Walker background and also by gravitational waves with toroidal wavefronts using an operational procedure. The results obtained for toroidal wavefronts are well behaved and reduce to the spherical wavefronts for a special choice.

  20. Tube-wave seismic imaging

    DOE Patents [OSTI]

    Korneev, Valeri A. (Lafayette, CA); Bakulin, Andrey (Houston, TX)

    2009-10-13T23:59:59.000Z

    The detailed analysis of cross well seismic data for a gas reservoir in Texas revealed two newly detected seismic wave effects, recorded approximately 2000 feet above the reservoir. A tube-wave (150) is initiated in a source well (110) by a source (111), travels in the source well (110), is coupled to a geological feature (140), propagates (151) through the geological feature (140), is coupled back to a tube-wave (152) at a receiver well (120), and is and received by receiver(s) (121) in either the same (110) or a different receiving well (120). The tube-wave has been shown to be extremely sensitive to changes in reservoir characteristics. Tube-waves appear to couple most effectively to reservoirs where the well casing is perforated, allowing direct fluid contact from the interior of a well case to the reservoir.