National Library of Energy BETA

Sample records for modeling performance tidal

  1. Dynamical modeling of tidal streams

    SciTech Connect (OSTI)

    Bovy, Jo, E-mail: bovy@ias.edu [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States)

    2014-11-01

    I present a new framework for modeling the dynamics of tidal streams. The framework consists of simple models for the initial action-angle distribution of tidal debris, which can be straightforwardly evolved forward in time. Taking advantage of the essentially one-dimensional nature of tidal streams, the transformation to position-velocity coordinates can be linearized and interpolated near a small number of points along the stream, thus allowing for efficient computations of a stream's properties in observable quantities. I illustrate how to calculate the stream's average location (its 'track') in different coordinate systems, how to quickly estimate the dispersion around its track, and how to draw mock stream data. As a generative model, this framework allows one to compute the full probability distribution function and marginalize over or condition it on certain phase-space dimensions as well as convolve it with observational uncertainties. This will be instrumental in proper data analysis of stream data. In addition to providing a computationally efficient practical tool for modeling the dynamics of tidal streams, the action-angle nature of the framework helps elucidate how the observed width of the stream relates to the velocity dispersion or mass of the progenitor, and how the progenitors of 'orphan' streams could be located. The practical usefulness of the proposed framework crucially depends on the ability to calculate action-angle variables for any orbit in any gravitational potential. A novel method for calculating actions, frequencies, and angles in any static potential using a single orbit integration is described in the Appendix.

  2. Sandia Energy - Tidal & Current Modeling Development and Validation

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

    Tidal & Current Modeling Development and Validation Home Stationary Power Energy Conversion Efficiency Water Power Technology Development Tidal & Current Modeling Development and...

  3. ARRAY OPTIMIZATION FOR TIDAL ENERGY EXTRACTION IN A TIDAL CHANNEL – A NUMERICAL MODELING ANALYSIS

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Wang, Taiping; Copping, Andrea

    2014-04-18

    This paper presents an application of a hydrodynamic model to simulate tidal energy extraction in a tidal dominated estuary in the Pacific Northwest coast. A series of numerical experiments were carried out to simulate tidal energy extraction with different turbine array configurations, including location, spacing and array size. Preliminary model results suggest that array optimization for tidal energy extraction in a real-world site is a very complex process that requires consideration of multiple factors. Numerical models can be used effectively to assist turbine siting and array arrangement in a tidal turbine farm for tidal energy extraction.

  4. The rotation and fracture history of Europa from modeling of tidal-tectonic processes

    E-Print Network [OSTI]

    Rhoden, Alyssa Rose

    2011-01-01

    the tidal stresses. They adopted a power-law viscoelasticpower of the model. However, the mechanics of tidal walking

  5. Tidal Downsizing model. I. Numerical methods: saving giant planets from tidal disruptions

    E-Print Network [OSTI]

    Nayakshin, Sergei

    2014-01-01

    Tidal Downsizing (TD) is a recently developed planet formation theory that supplements the classical Gravitational disc Instability (GI) model with planet migration inward and tidal disruptions of GI fragments in the inner regions of the disc. Numerical methods for a detailed population synthesis of TD planets are presented here. As an example application, the conditions under which GI fragments collapse faster than they migrate into the inner $a\\sim$ few AU disc are considered. It is found that most gas fragments are tidally or thermally disrupted unless (a) their opacity is $\\sim 3$ orders of magnitude less than the interstellar dust opacity at metallicities typical of the observed giant planets, or (b) the opacity is high but the fragments accrete large dust grains (pebbles) from the disc. Case (a) models produce very low mass solid cores ($M_{\\rm core} < 0.1$ Earth masses) and follow a negative correlation of giant planet frequency with host star metallicity. In contrast, case (b) models produce massiv...

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

    SciTech Connect (OSTI)

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

    2014-09-30

    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.

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

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Wang, Taiping

    2013-08-15

    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.

  8. 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.

    2013-02-28

    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.

  9. 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

  10. Reference Model #1 - Tidal Energy: Resource Dr. Brian Polagye

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

    constituents, as well as the aharmonic response to these currents induced by local topography and bathymetry. Aharmonic currents are not described by tidal constituents, but are...

  11. Comparing the escape dynamics in tidally limited star cluster models

    E-Print Network [OSTI]

    Euaggelos E. Zotos

    2015-08-21

    The aim of this work is to compare the orbital dynamics in three different models describing the properties of a star cluster rotating around its parent galaxy in a circular orbit. In particular, we use the isochrone and the Hernquist potentials to model the spherically symmetric star cluster and we compare our results with the corresponding ones of a previous work in which the Plummer model was applied for the same purpose. Our analysis takes place both in the configuration $(x,y)$ and in the phase $(x,\\dot{x})$ space in order to elucidate the escape process as well as the overall orbital properties of the tidally limited star cluster. We restrict our investigation into two dimensions and we conduct a thorough numerical analysis distinguishing between ordered and chaotic orbits as well as between trapped and escaping orbits, considering only unbounded motion for several energy levels above the critical escape energy. It is of particular interest to determine the escape basins towards the two exit channels (near the Lagrangian points $L_1$ and $L_2$) and relate them with the corresponding escape times of the orbits.

  12. Comparing the escape dynamics in tidally limited star cluster models

    E-Print Network [OSTI]

    Zotos, Euaggelos E

    2015-01-01

    The aim of this work is to compare the orbital dynamics in three different models describing the properties of a star cluster rotating around its parent galaxy in a circular orbit. In particular, we use the isochrone and the Hernquist potentials to model the spherically symmetric star cluster and we compare our results with the corresponding ones of a previous work in which the Plummer model was applied for the same purpose. Our analysis takes place both in the configuration $(x,y)$ and in the phase $(x,\\dot{x})$ space in order to elucidate the escape process as well as the overall orbital properties of the tidally limited star cluster. We restrict our investigation into two dimensions and we conduct a thorough numerical analysis distinguishing between ordered and chaotic orbits as well as between trapped and escaping orbits, considering only unbounded motion for several energy levels above the critical escape energy. It is of particular interest to determine the escape basins towards the two exit channels (n...

  13. 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.

    2013-11-09

    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.

  14. 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.

    2014-10-01

    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.

  15. Sandia Energy - Tidal & Current Modeling Development and Validation

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II)GeothermalFuel Magnetization andStochasticunique wind(CREW)Tidal &

  16. An Alternative Model for the Tidal Evolution of the Earth-Moon-Sun System

    E-Print Network [OSTI]

    Arbab I. Arbab

    2007-09-12

    We have found that the expansion of the universe has immense consequences on our local systems. We present a model based on cosmic expansion that fits well with observation. The close approach problem inflicting tidal theory is averted in this model. We have shown that the astronomical and geological changes of our local systems are of the order of Hubble constant.

  17. Modeling tidal flow in the Great Bay Estuary, New Hampshire, using a depth averaged

    E-Print Network [OSTI]

    Modeling tidal flow in the Great Bay Estuary, New Hampshire, using a depth averaged flooding, University of New Hampshire, USA. 2 Numerical Methods Lab., Dartmouth College, USA. 3 Ocean Process Analysis Lab., University of New Hampshire, USA. Abstract Current, sea level and bed load transport

  18. Tidal Downsizing Model. IV. Destructive feedback in planets

    E-Print Network [OSTI]

    Nayakshin, Sergei

    2015-01-01

    I argue that feedback is as important to formation of planets as it is to formation of stars and galaxies. Energy released by massive solid cores puffs up pre-collapse gas giant planets, making them vulnerable to tidal disruptions by their host stars. I find that feedback is the ultimate reason for some of the most robust properties of the observed exoplanet populations: the rarity of gas giants at all separations from $\\sim 0.1$ to $\\sim 100$~AU, the abundance of $\\sim 10 M_\\oplus$ cores but dearth of planets more massive than $\\sim 20 M_\\oplus$. Feedback effects can also explain (i) rapid assembly of massive cores at large separations as needed for Uranus, Neptune and the suspected HL Tau planets; (ii) the small core in Jupiter yet large cores in Uranus and Neptune; (iii) the existence of rare "metal monster" planets such as CoRoT-20b, a gas giant made of heavy elements by up to $\\sim 50$\\%.

  19. IR DIAL performance modeling

    SciTech Connect (OSTI)

    Sharlemann, E.T.

    1994-07-01

    We are developing a DIAL performance model for CALIOPE at LLNL. The intent of the model is to provide quick and interactive parameter sensitivity calculations with immediate graphical output. A brief overview of the features of the performance model is given, along with an example of performance calculations for a non-CALIOPE application.

  20. Stellar and gas dynamical model for tidal disruption events in a quiescent galaxy

    E-Print Network [OSTI]

    Mageshwaran, T

    2015-01-01

    A detailed model of the tidal disruption events (TDE) has been constructed using stellar dynamical and gas dynamical inputs that include black hole mass $M_{\\bullet}$, specific orbital energy $E$ and angular momentum $J$, star mass $M_{\\star}$ and radius $R_{\\star}$ and pericenter of the star orbit $r_{p}(E,\\hspace{1mm}J,\\hspace{1mm}M_{\\bullet})$. We have solved the steady state Fokker- Planck equation using the standard loss cone theory for the galactic density profile $\\rho (r) \\propto r^{-\\gamma}$ and stellar mass function $\\xi(m) $ where $m=M_{\\star}/M_{\\odot}$ and obtained the feeding rate of stars to the black hole integrated over the phase space as $\\dot{N}_{t} \\propto M_{\\bullet}^\\beta$ where $\\beta= -0.3\\pm 0.01$ for $M_{\\bullet}>10^7 M_{\\odot}$ and $\\sim 6.8 \\hspace{1mm} \\times 10^{-5}$ Yr$^{-1}$ for $\\gamma=0.7$. Using this we model the in fall rate of the disrupted debris, $\\dot{M}(E,\\hspace{1mm}J,\\hspace{1mm}m,\\hspace{1mm}t)$ and discuss conditions for the disk formation and find that the accreti...

  1. Tidal Downsizing Model. III. Planets from sub-Earths to Brown Dwarfs: structure and metallicity preferences

    E-Print Network [OSTI]

    Nayakshin, Sergei

    2015-01-01

    We present improved population synthesis calculations in the context of the Tidal Downsizing (TD) hypothesis for planet formation. Our models provide natural explanations and/or quantitative match to exoplanet observations in the following categories: (i) most abundant planets being super-Earths; (ii) cores more massive than $\\sim 5-15 M_\\oplus$ are enveloped by massive metal-rich atmospheres; (iii) the frequency of occurrence of close-in gas giant planets correlates strongly with metallicity of the host star; (iv) no such correlation is found for sub-Neptune planets; (v) presence of massive cores in giant planets; (vi) the composition of gas giant planets is over-abundant in metals compared to their host stars; (vii) this over-abundance decreases with planet's mass, as observed; (viii) a deep valley in the planet mass function between masses of $\\sim 10-20 M_\\oplus$ and $\\sim 100 M_\\oplus$. We provide a number of observational predictions distinguishing the model from Core Accretion: (a) composition of the m...

  2. Modeling Tidal Freshwater Marsh Sustainability in the Sacramento–San Joaquin Delta Under a Broad Suite of Potential Future Scenarios

    E-Print Network [OSTI]

    Swanson, Kathleen M.; Drexler, Judith Z.; Fuller, Christopher C.; Schoellhamer, David H.

    2015-01-01

    Tidal Freshwater Marsh Sustainability in the Sacramento–Sanof pulsing events to sustainability. Estuaries Coasts 18:Evaluating tidal marsh sustainability in the face of sea-

  3. Dissecting the pressure field in tidal flow

    E-Print Network [OSTI]

    amplitude [N x 107 ] phase relative to the velocity [deg] power [W x107 ] 1 2 3 4 tidal excursion parameterDissecting the pressure field in tidal flow past a headland: When is form drag "real?" Sally Warner waves eddies H L LHH H L L LH #12;Numerical model Gaussian-shaped headland Barotropic tidal velocity D L

  4. Modeling Tidal Freshwater Marsh Sustainability in the Sacramento–San Joaquin Delta Under a Broad Suite of Potential Future Scenarios

    E-Print Network [OSTI]

    Swanson, Kathleen M.; Drexler, Judith Z.; Fuller, Christopher C.; Schoellhamer, David H.

    2015-01-01

    tidal freshwater marsh sites in the Delta Site name Coordinates Area (ha) Elevation above MSL (cm) Salinity regime Energy

  5. Modeling Tidal Freshwater Marsh Sustainability in the Sacramento–San Joaquin Delta Under a Broad Suite of Potential Future Scenarios

    E-Print Network [OSTI]

    Swanson, Kathleen M.; Drexler, Judith Z.; Fuller, Christopher C.; Schoellhamer, David H.

    2015-01-01

    Table 1 Location and basic characteristics of tidal freshwater marsh sites in the Delta Site name Coordinates

  6. NATIONAL GEODATABASE OF TIDAL STREAM POWER RESOURCE IN USA

    SciTech Connect (OSTI)

    Smith, Brennan T; Neary, Vincent S; Stewart, Kevin M

    2012-01-01

    A geodatabase of tidal constituents is developed to present the regional assessment of tidal stream power resource in the USA. Tidal currents are numerically modeled with the Regional Ocean Modeling System (ROMS) and calibrated with the available measurements of tidal current speeds and water level surfaces. The performance of the numerical model in predicting the tidal currents and water levels is assessed by an independent validation. The geodatabase is published on a public domain via a spatial database engine with interactive tools to select, query and download the data. Regions with the maximum average kinetic power density exceeding 500 W/m2 (corresponding to a current speed of ~1 m/s), total surface area larger than 0.5 km2 and depth greater than 5 m are defined as hotspots and documented. The regional assessment indicates that the state of Alaska (AK) has the largest number of locations with considerably high kinetic power density, followed by, Maine (ME), Washington (WA), Oregon (OR), California (CA), New Hampshire (NH), Massachusetts (MA), New York (NY), New Jersey (NJ), North and South Carolina (NC, SC), Georgia (GA), and Florida (FL).

  7. In: J. Waterway, Port, Coastal, and Ocean Engineering, 126(3): 305-313, 2000. Reservoir Model of Ebb-Tidal Shoal Evolution and Sand Bypassing

    E-Print Network [OSTI]

    US Army Corps of Engineers

    of Ebb-Tidal Shoal Evolution and Sand Bypassing By Nicholas C. Kraus,1 Member, ASCE ABSTRACT A mathematical model is presented for calculating the change in volume and sand-bypassing rate at ebb reservoir can fill to a maximum (equilibrium) volume. The ratio of the input longshore sand transport rate

  8. A TWO-COMPONENT JET MODEL FOR THE TIDAL DISRUPTION EVENT SWIFT J164449.3+573451

    SciTech Connect (OSTI)

    Liu, Dangbo; Pe'er, Asaf; Loeb, Abraham

    2015-01-01

    We analyze both the early- and late-time radio and X-ray data of the tidal disruption event (TDE) Swift J1644+57. The data at early times (? 5 days) necessitate separation of the radio and X-ray emission regions, either spatially or in velocity space. This leads us to suggest a two-component jet model, in which the inner jet is initially relativistic with Lorentz factor ? ? 15, while the outer jet is trans-relativistic, with ? ? 1.2. This model enables a self-consistent interpretation of the late-time radio data, both in terms of peak frequency and flux. We solve the dynamics, radiative cooling, and expected radiation from both jet components. We show that while during the first month synchrotron emission from the outer jet dominates the radio emission, at later times, radiation from ambient gas collected by the inner jet dominates. This provides a natural explanation to the observed re-brightening, without the need for late-time inner engine activity. After 100 days, the radio emission peak is in the optically thick regime, leading to a decay of both the flux and peak frequency at later times. Our model's predictions for the evolution of radio emission in jetted TDEs can be tested by future observations.

  9. Tidal Energy Research

    SciTech Connect (OSTI)

    Stelzenmuller, Nickolas; Aliseda, Alberto; Palodichuk, Michael; Polagye, Brian; Thomson, James; Chime, Arshiya; Malte, Philip

    2014-03-31

    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.

  10. Air Conditioner Compressor Performance Model

    SciTech Connect (OSTI)

    Lu, Ning; Xie, YuLong; Huang, Zhenyu

    2008-09-05

    During the past three years, the Western Electricity Coordinating Council (WECC) Load Modeling Task Force (LMTF) has led the effort to develop the new modeling approach. As part of this effort, the Bonneville Power Administration (BPA), Southern California Edison (SCE), and Electric Power Research Institute (EPRI) Solutions tested 27 residential air-conditioning units to assess their response to delayed voltage recovery transients. After completing these tests, different modeling approaches were proposed, among them a performance modeling approach that proved to be one of the three favored for its simplicity and ability to recreate different SVR events satisfactorily. Funded by the California Energy Commission (CEC) under its load modeling project, researchers at Pacific Northwest National Laboratory (PNNL) led the follow-on task to analyze the motor testing data to derive the parameters needed to develop a performance models for the single-phase air-conditioning (SPAC) unit. To derive the performance model, PNNL researchers first used the motor voltage and frequency ramping test data to obtain the real (P) and reactive (Q) power versus voltage (V) and frequency (f) curves. Then, curve fitting was used to develop the P-V, Q-V, P-f, and Q-f relationships for motor running and stalling states. The resulting performance model ignores the dynamic response of the air-conditioning motor. Because the inertia of the air-conditioning motor is very small (H<0.05), the motor reaches from one steady state to another in a few cycles. So, the performance model is a fair representation of the motor behaviors in both running and stalling states.

  11. Tidal Energy Basics

    Broader source: Energy.gov [DOE]

    Some of the oldest ocean energy technologies use tidal power. For tidal differences to be harnessed into electricity, the difference between high and low tides must be more than 16 feet (or at least 5 meters). However, there are only about 40 sites on Earth with tidal ranges of this magnitude.

  12. Tidal networks 3. Landscape-forming discharges and studies

    E-Print Network [OSTI]

    Fagherazzi, Sergio

    Tidal networks 3. Landscape-forming discharges and studies in empirical geomorphic relationships peak ebb and flood discharges throughout a tidal network and use this model to investigate scaling flows are driven by spring (astronomical) tidal fluctuations (rather than precipitation- induced runoff

  13. Research papers Tidal characteristics of the gulf of Tonkin

    E-Print Network [OSTI]

    calibration derived from a set of sensitivity experiments to model parameters. The tidal energy budgetResearch papers Tidal characteristics of the gulf of Tonkin Nguyen Nguyet Minh a,c , Marchesiello of this study is to revisit the dominant physical processes that characterize tidal dynamics in the Gulf

  14. TEA - a linear frequency domain finite element model for tidal embayment analysis

    E-Print Network [OSTI]

    Westerink, Joannes J.

    1984-01-01

    A frequency domain (harmonic) finite element model is developed for the numerical prediction of depth average circulation within small embayments. Such embayments are often characterized by irregular boundaries and bottom ...

  15. Sandia Energy - PV Reliability & Performance Model

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

    Model PV Reliability & Performance ModelTara Camacho-Lopez2015-06-01T20:13:00+00:00 This Web Demo model is a simplified "player" version of the Photovoltaic Reliability Performance...

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

    Open Energy Info (EERE)

    Page Edit History Clarence Strait Tidal Energy Project, Tenax Energy Tropical Tidal Test Centre, Jump to: navigation, search 1 Retrieved from "http:en.openei.orgw...

  17. Maine Tidal Power Initiative: Environmental Impact Protocols For Tidal Power

    SciTech Connect (OSTI)

    Peterson, Michael Leroy; Zydlewski, Gayle Barbin; Xue, Huijie; Johnson, Teresa R.

    2014-02-02

    The Maine Tidal Power Initiative (MTPI), an interdisciplinary group of engineers, biologists, oceanographers, and social scientists, has been conducting research to evaluate tidal energy resources and better understand the potential effects and impacts of marine hydro-kinetic (MHK) development on the environment and local community. Project efforts include: 1) resource assessment, 2) development of initial device design parameters using scale model tests, 3) baseline environmental studies and monitoring, and 4) human and community responses. This work included in-situ measurement of the environmental and social response to the pre-commercial Turbine Generator Unit (TGU®) developed by Ocean Renewable Power Company (ORPC) as well as considering the path forward for smaller community scale projects.

  18. Statistical Performance Modeling of SRAMs 

    E-Print Network [OSTI]

    Zhao, Chang

    2011-02-22

    Yield analysis is a critical step in memory designs considering a variety of performance constraints. Traditional circuit level Monte-Carlo simulations for yield estimation of Static Random Access Memory (SRAM) cell is quite time consuming due...

  19. ORIGINAL PAPER Predicting Avian Abundance Within and Across Tidal

    E-Print Network [OSTI]

    Kelly, Maggi

    ORIGINAL PAPER Predicting Avian Abundance Within and Across Tidal Marshes Using Fine Scientists 2010 Abstract Tidal marsh monitoring and restoration can benefit from the union of fine developed statistical models with relatively high explanatory power. In each case, models were improved

  20. TEG On-Vehicle Performance & Model Validation

    Broader source: Energy.gov [DOE]

    Details efforts and results of steady-state and transient models validated with bench, engine dynamometer, and on-vehicle tests to measure actual performance

  1. CONTROL ID: 1187959 TITLE: Climate destabilization on tidally locked exoplanets

    E-Print Network [OSTI]

    CONTROL ID: 1187959 TITLE: Climate destabilization on tidally locked exoplanets PRESENTATION TYPE-zone rocky planets, should be tidally locked. We will discuss two different feedbacks that can destabilize cause a runaway climate shift. We use an idealized energy balance model to illustrate the scope

  2. 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

    2014-04-30

    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.

  3. Generic CSP Performance Model for NREL's System Advisor Model: Preprint

    SciTech Connect (OSTI)

    Wagner, M. J.; Zhu, G.

    2011-08-01

    The suite of concentrating solar power (CSP) modeling tools in NREL's System Advisor Model (SAM) includes technology performance models for parabolic troughs, power towers, and dish-Stirling systems. Each model provides the user with unique capabilities that are catered to typical design considerations seen in each technology. Since the scope of the various models is generally limited to common plant configurations, new CSP technologies, component geometries, and subsystem combinations can be difficult to model directly in the existing SAM technology models. To overcome the limitations imposed by representative CSP technology models, NREL has developed a 'Generic Solar System' (GSS) performance model for use in SAM. This paper discusses the formulation and performance considerations included in this model and verifies the model by comparing its results with more detailed models.

  4. Performance analysis and modeling of GYRO 

    E-Print Network [OSTI]

    Lively, Charles Wesley, III

    2006-10-30

    and the system used for execution. In particular, models can be used to predict the relative performance of different systems used to execute an application. Recently, a significant effort has been devoted to gaining a more detailed understanding...

  5. Improving recognition performance by modelling pronunciation variation. 

    E-Print Network [OSTI]

    Kessens, Judith M; Wester, Mirjam

    1997-01-01

    This paper describes a method for improving the performance of a continuous speech recognizer by modelling pronunciation variation. Although the improvements obtained with this method are small, they are in line with those ...

  6. Modeling well performance in compartmentalized gas reservoirs 

    E-Print Network [OSTI]

    Yusuf, Nurudeen

    2009-05-15

    and performance characteristics of each compartment in such reservoirs given production data. A geomechanics model was developed using available correlation in the industry to estimate variable pore volume compressibility, reservoir compaction and permeability...

  7. Underestimation of the UK Tidal David J.C. MacKay

    E-Print Network [OSTI]

    MacKay, David J.C.

    there and would deliver up to 40 GW (peak). In this note, I present back­of­envelope models of tidal power special cases) the power in tidal waves is not equal to the kinetic energy flux across a plane. These backUnder­estimation of the UK Tidal Resource David J.C. MacKay Cavendish Laboratory, University

  8. Under-estimation of the UK Tidal David J.C. MacKay

    E-Print Network [OSTI]

    MacKay, David J.C.

    there and would deliver up to 40 GW (peak). In this note, I present back-of-envelope models of tidal power special cases) the power in tidal waves is not equal to the kinetic energy flux across a plane. These backUnder-estimation of the UK Tidal Resource David J.C. MacKay Cavendish Laboratory, University

  9. Internal hydraulic jumps and overturning generated by tidal flow over a tall steep ridge

    E-Print Network [OSTI]

    Klymak, Jody M.

    that tidal energy is both converted into internal waves, which radiate away from the topography, and used of tidal mixing for global climate models, the physical processes governing the transfer of energy fromInternal hydraulic jumps and overturning generated by tidal flow over a tall steep ridge Sonya Legg

  10. Dissipation at tidal and seismic frequencies in a melt-free Moon U. H. Faul,2

    E-Print Network [OSTI]

    Nimmo, Francis

    Dissipation at tidal and seismic frequencies in a melt-free Moon F. Nimmo,1 U. H. Faul,2 and E. J. Successful models can reproduce the dissipation factor (Q) measured at both tidal and seismic frequencies, and the tidal Love numbers h2 and k2, without requiring any mantle melting. However, the frequency

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

    E-Print Network [OSTI]

    into state-of-the-art climate models. Calculation of the tidal energy flux depends on 7 1 Tidal mixing around the Maritime continent: implications for1 paleoclimate simulations2, New Haven, CT, 06511 4 Abstract 5 Tidal mixing provides an important source

  12. Europa: Tidal heating of upwelling thermal plumes and the origin of lenticulae and chaos melting

    E-Print Network [OSTI]

    Head III, James William

    ; Pappalardo and Head, 2001], and 3) a seafloor plume model in which tidal energy focused in the silicate ice in the shallow crust of Europa. We show that tidal energy can be preferentially focused in risingEuropa: Tidal heating of upwelling thermal plumes and the origin of lenticulae and chaos melting

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

    SciTech Connect (OSTI)

    Wright, Bruce Albert

    2014-05-07

    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.

  14. Low-Order Modelling of Blade-Induced Turbulence for RANS Actuator Disk Computations of Wind and Tidal Turbines

    E-Print Network [OSTI]

    Nishino, Takafumi

    2012-01-01

    Modelling of turbine blade-induced turbulence (BIT) is discussed within the framework of three-dimensional Reynolds-averaged Navier-Stokes (RANS) actuator disk computations. We first propose a generic (baseline) BIT model, which is applied only to the actuator disk surface, does not include any model coefficients (other than those used in the original RANS turbulence model) and is expected to be valid in the limiting case where BIT is fully isotropic and in energy equilibrium. The baseline model is then combined with correction functions applied to the region behind the disk to account for the effect of rotor tip vortices causing a mismatch of Reynolds shear stress between short- and long-time averaged flow fields. Results are compared with wake measurements of a two-bladed wind turbine model of Medici and Alfredsson [Wind Energy, Vol. 9, 2006, pp. 219-236] to demonstrate the capability of the new model.

  15. PV performance modeling workshop summary report.

    SciTech Connect (OSTI)

    Stein, Joshua S.; Tasca, Coryne Adelle (SRA International, Inc., Fairfax, VA); Cameron, Christopher P.

    2011-05-01

    During the development of a solar photovoltaic (PV) energy project, predicting expected energy production from a system is a key part of understanding system value. System energy production is a function of the system design and location, the mounting configuration, the power conversion system, and the module technology, as well as the solar resource. Even if all other variables are held constant, annual energy yield (kWh/kWp) will vary among module technologies because of differences in response to low-light levels and temperature. A number of PV system performance models have been developed and are in use, but little has been published on validation of these models or the accuracy and uncertainty of their output. With support from the U.S. Department of Energy's Solar Energy Technologies Program, Sandia National Laboratories organized a PV Performance Modeling Workshop in Albuquerque, New Mexico, September 22-23, 2010. The workshop was intended to address the current state of PV system models, develop a path forward for establishing best practices on PV system performance modeling, and set the stage for standardization of testing and validation procedures for models and input parameters. This report summarizes discussions and presentations from the workshop, as well as examines opportunities for collaborative efforts to develop objective comparisons between models and across sites and applications.

  16. Climate Modeling using High-Performance Computing

    SciTech Connect (OSTI)

    Mirin, A A

    2007-02-05

    The Center for Applied Scientific Computing (CASC) and the LLNL Climate and Carbon Science Group of Energy and Environment (E and E) are working together to improve predictions of future climate by applying the best available computational methods and computer resources to this problem. Over the last decade, researchers at the Lawrence Livermore National Laboratory (LLNL) have developed a number of climate models that provide state-of-the-art simulations on a wide variety of massively parallel computers. We are now developing and applying a second generation of high-performance climate models. Through the addition of relevant physical processes, we are developing an earth systems modeling capability as well.

  17. Modeling Tidal Freshwater Marsh Sustainability in the Sacramento–San Joaquin Delta Under a Broad Suite of Potential Future Scenarios

    E-Print Network [OSTI]

    Swanson, Kathleen M.; Drexler, Judith Z.; Fuller, Christopher C.; Schoellhamer, David H.

    2015-01-01

    energy zones because of their higher inorganic sediment supply.supply (25 suites of 18 model scenarios each), we could not clearly define a single tertiary The high- and low-energy

  18. Smart Grid Cybersecurity: Job Performance Model Report and Phase...

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

    Cybersecurity: Job Performance Model Report and Phase 1 Overview (August 2012) Smart Grid Cybersecurity: Job Performance Model Report and Phase 1 Overview (August 2012) In the...

  19. Fuel Cell Power Model for CHHP System Economics and Performance...

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

    Model for CHHP System Economics and Performance Analysis Fuel Cell Power Model for CHHP System Economics and Performance Analysis Presented at the Renewable Hydrogen Workshop, Nov....

  20. System Advisor Model: Flat Plate Photovoltaic Performance Modeling Validation Report

    SciTech Connect (OSTI)

    Freeman, J.; Whitmore, J.; Kaffine, L.; Blair, N.; Dobos, A. P.

    2013-12-01

    The System Advisor Model (SAM) is a free software tool that performs detailed analysis of both system performance and system financing for a variety of renewable energy technologies. This report provides detailed validation of the SAM flat plate photovoltaic performance model by comparing SAM-modeled PV system generation data to actual measured production data for nine PV systems ranging from 75 kW to greater than 25 MW in size. The results show strong agreement between SAM predictions and field data, with annualized prediction error below 3% for all fixed tilt cases and below 8% for all one axis tracked cases. The analysis concludes that snow cover and system outages are the primary sources of disagreement, and other deviations resulting from seasonal biases in the irradiation models and one axis tracking issues are discussed in detail.

  1. Tidal heating in multilayered terrestrial exoplanets

    SciTech Connect (OSTI)

    Henning, Wade G.; Hurford, Terry

    2014-07-01

    The internal pattern and overall magnitude of tidal heating for spin-synchronous terrestrial exoplanets from 1 to 2.5 R{sub E} is investigated using a propagator matrix method for a variety of layer structures. Particular attention is paid to ice-silicate hybrid super-Earths, where a significant ice mantle is modeled to rest atop an iron-silicate core, and may or may not contain a liquid water ocean. We find multilayer modeling often increases tidal dissipation relative to a homogeneous model, across multiple orbital periods, due to the ability to include smaller volume low viscosity regions, and the added flexure allowed by liquid layers. Gradations in parameters with depth are explored, such as allowed by the Preliminary Earth Reference Model. For ice-silicate hybrid worlds, dramatically greater dissipation is possible beyond the case of a silicate mantle only, allowing non-negligible tidal activity to extend to greater orbital periods than previously predicted. Surface patterns of tidal heating are found to potentially be useful for distinguishing internal structure. The influence of ice mantle depth and water ocean size and position are shown for a range of forcing frequencies. Rates of orbital circularization are found to be 10-100 times faster than standard predictions for Earth-analog planets when interiors are moderately warmer than the modern Earth, as well as for a diverse range of ice-silicate hybrid super-Earths. Circularization rates are shown to be significantly longer for planets with layers equivalent to an ocean-free modern Earth, as well as for planets with high fractions of either ice or silicate melting.

  2. Performance model assessment for multi-junction concentrating photovoltaic systems.

    SciTech Connect (OSTI)

    Riley, Daniel M.; McConnell, Robert.; Sahm, Aaron; Crawford, Clark; King, David L.; Cameron, Christopher P.; Foresi, James S.

    2010-03-01

    Four approaches to modeling multi-junction concentrating photovoltaic system performance are assessed by comparing modeled performance to measured performance. Measured weather, irradiance, and system performance data were collected on two systems over a one month period. Residual analysis is used to assess the models and to identify opportunities for model improvement.

  3. High performance computing and numerical modelling

    E-Print Network [OSTI]

    ,

    2014-01-01

    Numerical methods play an ever more important role in astrophysics. This is especially true in theoretical works, but of course, even in purely observational projects, data analysis without massive use of computational methods has become unthinkable. The key utility of computer simulations comes from their ability to solve complex systems of equations that are either intractable with analytic techniques or only amenable to highly approximative treatments. Simulations are best viewed as a powerful complement to analytic reasoning, and as the method of choice to model systems that feature enormous physical complexity such as star formation in evolving galaxies, the topic of this 43rd Saas Fee Advanced Course. The organizers asked me to lecture about high performance computing and numerical modelling in this winter school, and to specifically cover the basics of numerically treating gravity and hydrodynamics in the context of galaxy evolution. This is still a vast field, and I necessarily had to select a subset ...

  4. Temperature and Tidal Dynamics in a Branching Estuarine System

    E-Print Network [OSTI]

    Wagner, Richard Wayne

    2012-01-01

    distribution of tidal energy. When specific locations ordissipation which may alter tidal energy in other parts ofAdditionally, changes to tidal energy reflection within a

  5. Microsoft Word - RM1_Tidal Turbine_UW Tidal Resource-Abstract...

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

    turbine operating in a narrow, tidal channel. The site is a generalized version of Tacoma Narrows, Puget Sound, Washington. The resource is a mixed, mainly semidiurnal tidal...

  6. Performance Modeling for 3D Visualization in a Heterogeneous...

    Office of Scientific and Technical Information (OSTI)

    and partitioning of the data analysis workflow. We explore a methodology for building a model of overall application performance using a composition of the analytic models...

  7. Sandia Energy - PV Performance Modeling Collaborative's New and...

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

    Modeling & Simulation Solar Newsletter Photovoltaic Systems Evaluation Laboratory (PSEL) PV Performance Modeling Collaborative's New and Improved Website Is Launched Previous Next...

  8. Numerical and Analytical Estimates of M2 Tidal Conversion at Steep Oceanic Ridges EMANUELE DI LORENZO

    E-Print Network [OSTI]

    Young, William R.

    of mechanical energy required to mix the global ocean (Garrett and St. Laurent 2002). Tidal forces perform aboutNumerical and Analytical Estimates of M2 Tidal Conversion at Steep Oceanic Ridges EMANUELE DI) ABSTRACT Numerical calculations of the rate at which energy is converted from the external to internal

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

    SciTech Connect (OSTI)

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

    2011-10-01

    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.

  10. Tidal evolution of close binary asteroid systems

    E-Print Network [OSTI]

    Taylor, PA; Margot, JL

    2010-01-01

    a positive fractional power of the tidal frequency (at leasttidal bulges of the components as these will depend on the square (or higher powers)power, natural deviations from a spherical shape may exceed the amplitude of the tidal

  11. 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.

    1997-08-01

    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.

  12. Tidal Energy System for On-Shore Power Generation

    SciTech Connect (OSTI)

    Bruce, Allan J

    2012-06-26

    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

  13. CALIBRATION OF PHOTOVOLTAIC MODULE PERFORMANCE MODELS USING MONITORED SYSTEM DATA

    E-Print Network [OSTI]

    CALIBRATION OF PHOTOVOLTAIC MODULE PERFORMANCE MODELS USING MONITORED SYSTEM DATA Clifford W Facilities Inc, Tokyo, Japan, hakuta22@ntt-f.co.jp ABSTRACT: Calibration of a photovoltaic module performance and validate methods to calibrate the Sandia Photovoltaic Array Performance Model and the California Energy

  14. Applying High Performance Computing to Analyzing by Probabilistic Model Checking

    E-Print Network [OSTI]

    Schneider, Carsten

    Applying High Performance Computing to Analyzing by Probabilistic Model Checking Mobile Cellular on the use of high performance computing in order to analyze with the proba- bilistic model checker PRISM. The Figure Generation Script 22 2 #12;1. Introduction We report in this paper on the use of high performance

  15. A Variable Cell Model for Simulating Gas Condensate Reservoir Performance

    E-Print Network [OSTI]

    Al-Majed, Abdulaziz Abdullah

    , SPE-~~~ SPE 21428 A Variable Cell Model for Simulating Gas Condensate Reservoir Performance A of depletion performance of gas condensate reservoirs report the existence of a A variable cell model for simulating gas relatively high, near-constant, oil saturation in condensate reeervoir performance has been

  16. System Identification and Modelling of a High Performance Hydraulic Actuator

    E-Print Network [OSTI]

    Hayward, Vincent

    System Identification and Modelling of a High Performance Hydraulic Actuator Benoit Boulet, Laeeque with the experimental identification and modelling of the nonlinear dynamics ofa high performance hydraulic actuator. The actuator properties and performance are also discussed. 1 Introduction Hydraulic actuation used to be

  17. Modeling well performance in compartmentalized gas reservoirs 

    E-Print Network [OSTI]

    Yusuf, Nurudeen

    2008-10-10

    for consolidated reservoir cases while synthetic data (generated by the model using known parameters) was used for unconsolidated reservoir cases. In both cases, the Compartmentalized Depletion Model was used to analyze data, and estimate the OGIP and Jg of each...

  18. Palomar 5 and its Tidal Tails: A Search for New Members in the Tidal Stream

    E-Print Network [OSTI]

    Kuzma, Pete; Keller, Stefan; Maunder, Elizabeth

    2014-01-01

    In this paper we present the results of a search for members of the globular cluster Palomar 5 and its associated tidal tails. The analysis has been performed using intermediate and low resolution spectroscopy with the AAOmega spectrograph on the Anglo-Australian Telescope. Based on kinematics, line strength and photometric information, we identify 39 new red giant branch stars along $\\sim$20$^{\\circ}$ of the tails, a larger angular extent than has been previously studied. We also recover eight previously known tidal tail members. Within the cluster, we find seven new red giant and one blue horizontal branch members and confirm a further twelve known red giant members. In total, we provide velocity data for 67 stars in the cluster and the tidal tails. Using a maximum likelihood technique, we derive a radial velocity for Pal 5 of $-57.4 \\pm 0.3$ km s$^{-1}$ and a velocity dispersion of $1.2\\pm0.3$ km s$^{-1}$. We confirm and extend the linear velocity gradient along the tails of $1.0 \\pm 0.1$ km s$^{-1}$ deg$^...

  19. A spatial characterization of the Sagittarius dwarf galaxy tidal tails

    SciTech Connect (OSTI)

    Newby, Matthew; Cole, Nathan; Newberg, Heidi Jo; Willett, Benjamin [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Desell, Travis [Department of Computer Science, U. of North Dakota, Grand Forks, ND 52802 (United States); Magdon-Ismail, Malik; Szymanski, Boleslaw; Varela, Carlos [Department of Computer Science, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Yanny, Brian, E-mail: newbym2@rpi.edu, E-mail: heidi@rpi.edu [Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States)

    2013-06-01

    We measure the spatial density of F turnoff stars in the Sagittarius dwarf tidal stream, from Sloan Digital Sky Survey data, using statistical photometric parallax. We find a set of continuous, consistent parameters that describe the leading Sgr stream's position, direction, and width for 15 stripes in the north Galactic cap, and three stripes in the south Galactic cap. We produce a catalog of stars that has the density characteristics of the dominant leading Sgr tidal stream that can be compared with simulations. We find that the width of the leading (north) tidal tail is consistent with recent triaxial and axisymmetric halo model simulations. The density along the stream is roughly consistent with common disruption models in the north, but possibly not in the south. We explore the possibility that one or more of the dominant Sgr streams has been misidentified, and that one or more of the ''bifurcated'' pieces is the real Sgr tidal tail, but we do not reach definite conclusions. If two dwarf progenitors are assumed, fits to the planes of the dominant and ''bifurcated'' tidal tails favor an association of the Sgr dwarf spheroidal galaxy with the dominant southern stream and the ''bifurcated'' stream in the north. In the north Galactic cap, the best fit Hernquist density profile for the smooth component of the stellar halo is oblate, with a flattening parameter q = 0.53, and a scale length of r {sub 0} = 6.73. The southern data for both the tidal debris and the smooth component of the stellar halo do not match the model fits to the north, although the stellar halo is still overwhelmingly oblate. Finally, we verify that we can reproduce the parameter fits on the asynchronous MilkyWay@home volunteer computing platform.

  20. Micro-Architecture Independent Analytical Processor Performance and Power Modeling

    E-Print Network [OSTI]

    Eeckhout, Lieven

    Micro-Architecture Independent Analytical Processor Performance and Power Modeling Sam Van den models that allow us to produce performance and power estimates across a large design space almost models. In this work we present a micro-architecture independent profiler and associated analytical

  1. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. ???, XXXX, DOI:10.1029/, Dissipation at tidal and seismic frequencies in a melt-free,

    E-Print Network [OSTI]

    Nimmo, Francis

    be readily detectable with future seismological observations. 1. Introduction The rate at which tidal energyJOURNAL OF GEOPHYSICAL RESEARCH, VOL. ???, XXXX, DOI:10.1029/, Dissipation at tidal and seismic of Phobos provides a constraint on the tidal dissipation factor, Q, within Mars. We model viscoelastic

  2. Scaling laws to quantify tidal dissipation in star-planet systems

    E-Print Network [OSTI]

    Auclair-Desrotour, Pierre; Poncin-Lafitte, Christophe Le

    2015-01-01

    Planetary systems evolve over secular time scales. One of the key mechanisms that drive this evolution is tidal dissipation. Submitted to tides, stellar and planetary fluid layers do not behave like rocky ones. Indeed, they are the place of resonant gravito-inertial waves. Therefore, tidal dissipation in fluid bodies strongly depends on the excitation frequency while this dependence is smooth in solid ones. Thus, the impact of the internal structure of celestial bodies must be taken into account when studying tidal dynamics. The purpose of this work is to present a local model of tidal gravito-inertial waves allowing us to quantify analytically the internal dissipation due to viscous friction and thermal diffusion, and to study the properties of the resonant frequency spectrum of the dissipated energy. We derive from this model scaling laws characterizing tidal dissipation as a function of fluid parameters (rotation, stratification, diffusivities) and discuss them in the context of star-planet systems.

  3. Hybrid Model of Existing Buildings for Transient Thermal Performance Estimation 

    E-Print Network [OSTI]

    Xu, X.; Wang, S.

    2006-01-01

    Building level energy models are important to provide accurate prediction of energy consumption for building performance diagnosis and energy efficiency assessment of retrofitting alternatives for building performance upgrading. Simplified...

  4. Degradation Pathway Models for Photovoltaics Module Lifetime Performance

    E-Print Network [OSTI]

    Rollins, Andrew M.

    Degradation Pathway Models for Photovoltaics Module Lifetime Performance Nicholas R. Wheeler, Laura data from Underwriter Labs, featuring measurements taken on 18 identical photovoltaic (PV) modules in modules and their effects on module performance over lifetime. Index Terms--photovoltaics, statistical

  5. Motivation Literature Network Performance Measure Network Robustness SCN Model Fin. Net. Model Conclusions Network Efficiency/Performance Measurement

    E-Print Network [OSTI]

    Nagurney, Anna

    Conclusions Network Efficiency/Performance Measurement with Vulnerability and Robustness Analysis Conclusions 1 Motivation 2 Literature Review 3 Network Efficiency/Performance Measure Variational Inequality Robustness SCN Model Fin. Net. Model Conclusions 1 Motivation 2 Literature Review 3 Network Efficiency/Performance

  6. Quality Assurance for Performance Assessment Modeling

    Broader source: Energy.gov [DOE]

    Presentation from the 2015 Annual Performance and Risk Assessment (P&RA) Community of Practice (CoP) Technical Exchange Meeting held in Richland, Washington on December 15-16, 2015.

  7. General relativistic tidal heating for Moller pseudotensor

    E-Print Network [OSTI]

    Lau Loi So

    2015-09-30

    Thorne elucidated that the relativistic tidal heating is the same as the Newtonian theory. Moreover, Thorne also claimed that the tidal heating is independent of how one localizes gravitational energy and is unambiguously given by a certain formula. Purdue and Favata calculated the tidal heating for different classical pseudotensors including Moller and obtained the results all matched with the Newtonian perspective. After re-examined this Moller pseudotensor, we find that there does not exist any tidal heating value. Thus we claim that the relativistic tidal heating is pseudotensor independent under the condition that if the peusdotensor is a Freud typed superpotential.

  8. General relativistic tidal heating for Moller pseudotensor

    E-Print Network [OSTI]

    So, Lau Loi

    2015-01-01

    Thorne elucidated that the relativistic tidal heating is the same as the Newtonian theory. Moreover, Thorne also claimed that the tidal heating is independent of how one localizes gravitational energy and is unambiguously given by a certain formula. Purdue and Favata calculated the tidal heating for different classical pseudotensors including Moller and obtained the results all matched with the Newtonian perspective. After re-examined this Moller pseudotensor, we find that there does not exist any tidal heating value. Thus we claim that the relativistic tidal heating is pseudotensor independent under the condition that if the peusdotensor is a Freud typed superpotential.

  9. Modeling the Mechanical Performance of Die Casting Dies

    SciTech Connect (OSTI)

    R. Allen Miller

    2004-02-27

    The following report covers work performed at Ohio State on modeling the mechanical performance of dies. The focus of the project was development and particularly verification of finite element techniques used to model and predict displacements and stresses in die casting dies. The work entails a major case study performed with and industrial partner on a production die and laboratory experiments performed at Ohio State.

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

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Wang, Taiping

    2013-08-30

    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.

  11. Detailed Performance Model for Photovoltaic Systems: Preprint

    SciTech Connect (OSTI)

    Tian, H.; Mancilla-David, F.; Ellis, K.; Muljadi, E.; Jenkins, P.

    2012-07-01

    This paper presents a modified current-voltage relationship for the single diode model. The single-diode model has been derived from the well-known equivalent circuit for a single photovoltaic cell. The modification presented in this paper accounts for both parallel and series connections in an array.

  12. Developing an Energy Performance Modeling Startup Kit

    SciTech Connect (OSTI)

    none,

    2012-10-01

    In 2011, the NAHB Research Center began assessing the needs and motivations of residential remodelers regarding energy performance remodeling. This report outlines: the current remodeling industry and the role of energy efficiency; gaps and barriers to adding energy efficiency into remodeling; and support needs of professional remodelers to increase sales and projects involving improving home energy efficiency.

  13. An Investigation into Satellite Drag Modeling Performance

    E-Print Network [OSTI]

    Mance, Stephen

    2010-03-23

    The errors in current atmospheric drag modeling are the primary source of error for orbit determination for objects in low Earth orbit (LEO) at lower altitudes in periods of high solar activity. This is a direct result of significant advancements...

  14. Performance Modelling of Database Contention using Queueing Petri Nets

    E-Print Network [OSTI]

    Knottenbelt, William J.

    Performance Modelling of Database Contention using Queueing Petri Nets David Coulden Rasha Osman Petri Net model of table-level database locking. We show that this model predicts mean response times modelling, database locking. 1. INTRODUCTION The data landscape has changed dramatically in size

  15. HIDDENARTICULATOR MARKOV MODELS: PERFORMANCE IMPROVEMENTS AND ROBUSTNESS TO NOISE

    E-Print Network [OSTI]

    Noble, William Stafford

    HIDDEN­ARTICULATOR MARKOV MODELS: PERFORMANCE IMPROVEMENTS AND ROBUSTNESS TO NOISE Matt Richardson@cs}.washington.edu ABSTRACT A Hidden­Articulator Markov Model (HAMM) is a Hidden Markov Model (HMM) in which each state], we extended the articulatory­feature model introduced by Erler [7] by using diphone units and a new

  16. Influence of two dynamic predictive clothing insulation models on building energy performance

    E-Print Network [OSTI]

    Lee, Kwang Ho; Schiavon, Stefano

    2013-01-01

    Clothing Model Impact on Building Energy PerformanceInsulation Models on Building Energy Performance K. H. LeeModel Impact on Building Energy Performance is one of the

  17. Modeling and Analysis of WAP Performance over Wireless Links

    E-Print Network [OSTI]

    Shen, Xuemin "Sherman"

    Modeling and Analysis of WAP Performance over Wireless Links Humphrey Rutagemwa, Student Member the performance behaviors of wireless application protocol (WAP) over wireless links is proposed. A Rayleigh fading channel model is used to characterize the behaviors of wireless channel. Mathematical expressions

  18. Tidally-induced thermonuclear Supernovae

    E-Print Network [OSTI]

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

    2008-11-13

    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.

  19. Performance Modeling of Shared Memory Programsof SharedMemory Programs

    E-Print Network [OSTI]

    Teo, Yong-Meng

    nus edu sg/~teoymURL: www.comp.nus.edu.sg/ teoym 7th Workshop on High Performance Computing UPM Analysis l i l d l­ Analytical Model · Summary 1 November 2011 47th Workshop on High Performance Computing November 2011 57th Workshop on High Performance Computing (invited talk) #12;R l t d W kRelated Work

  20. Developing an Energy Performance Modeling Startup Kit

    SciTech Connect (OSTI)

    Wood, A.

    2012-10-01

    In 2011, the NAHB Research Center began the first part of the multi-year effort by assessing the needs and motivations of residential remodelers regarding energy performance remodeling. The scope is multifaceted - all perspectives will be sought related to remodeling firms ranging in size from small-scale, sole proprietor to national. This will allow the Research Center to gain a deeper understanding of the remodeling and energy retrofit business and the needs of contractors when offering energy upgrade services. To determine the gaps and the motivation for energy performance remodeling, the NAHB Research Center conducted (1) an initial series of focus groups with remodelers at the 2011 International Builders' Show, (2) a second series of focus groups with remodelers at the NAHB Research Center in conjunction with the NAHB Spring Board meeting in DC, and (3) quantitative market research with remodelers based on the findings from the focus groups. The goal was threefold, to: Understand the current remodeling industry and the role of energy efficiency; Identify the gaps and barriers to adding energy efficiency into remodeling; and Quantify and prioritize the support needs of professional remodelers to increase sales and projects involving improving home energy efficiency. This report outlines all three of these tasks with remodelers.

  1. Cost and Performance Assumptions for Modeling Electricity Generation Technologies

    SciTech Connect (OSTI)

    Tidball, R.; Bluestein, J.; Rodriguez, N.; Knoke, S.

    2010-11-01

    The goal of this project was to compare and contrast utility scale power plant characteristics used in data sets that support energy market models. Characteristics include both technology cost and technology performance projections to the year 2050. Cost parameters include installed capital costs and operation and maintenance (O&M) costs. Performance parameters include plant size, heat rate, capacity factor or availability factor, and plant lifetime. Conventional, renewable, and emerging electricity generating technologies were considered. Six data sets, each associated with a different model, were selected. Two of the data sets represent modeled results, not direct model inputs. These two data sets include cost and performance improvements that result from increased deployment as well as resulting capacity factors estimated from particular model runs; other data sets represent model input data. For the technologies contained in each data set, the levelized cost of energy (LCOE) was also evaluated, according to published cost, performance, and fuel assumptions.

  2. 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.

    2011-09-30

    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.

  3. TIDAL NOVAE IN COMPACT BINARY WHITE DWARFS

    SciTech Connect (OSTI)

    Fuller, Jim; Lai Dong [Department of Astronomy, Cornell University, Ithaca, NY 14850 (United States)

    2012-09-01

    Compact binary white dwarfs (WDs) undergoing orbital decay due to gravitational radiation can experience significant tidal heating prior to merger. In these WDs, the dominant tidal effect involves the excitation of outgoing gravity waves in the inner stellar envelope and the dissipation of these waves in the outer envelope. As the binary orbit decays, the WDs are synchronized from outside in (with the envelope synchronized first, followed by the core). We examine the deposition of tidal heat in the envelope of a carbon-oxygen WD and study how such tidal heating affects the structure and evolution of the WD. We show that significant tidal heating can occur in the star's degenerate hydrogen layer. This layer heats up faster than it cools, triggering runaway nuclear fusion. Such 'tidal novae' may occur in all WD binaries containing a CO WD, at orbital periods between 5 minutes and 20 minutes, and precede the final merger by 10{sup 5}-10{sup 6} years.

  4. Disc formation from stellar tidal disruptions

    E-Print Network [OSTI]

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

    2015-01-01

    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...

  5. How does vegetation affect sedimentation on tidal marshes? Investigating particle capture and hydrodynamic controls

    E-Print Network [OSTI]

    Mudd, Simon Marius

    How does vegetation affect sedimentation on tidal marshes? Investigating particle capture stems, or enhanced settling due to a reduction in turbulent kinetic energy within flows through kinetic energy in the fertilized canopy. Our newly developed models of biologically mediated sedimentation

  6. Performance modelling of a proton exchange membrane fuel cell

    SciTech Connect (OSTI)

    Marr, C.; Li, X.

    1998-12-31

    This paper presents a performance model of a proton exchange membrane fuel cell that has sufficient accuracy for engineering applications with reduced computational requirements. The model includes electrochemical reaction in the catalyst layers and formulation for electrical resistance in the membrane, electrodes and bipolar plates, and employs engineering correlation for the reactant gas transport in the flow channels and through the electrodes. It is shown that the present model predictions are in reasonable agreement with known experimental observations, indicating that the present model can be employed for fuel cell stack and system modeling. The effect of various operating and design parameters on the cell performance has been investigated. It is found that mass transport limitations are the largest cause of performance loss in the cell when graphite is used as the material for bipolar plates and electrodes. If conducting polymers are substituted as construction materials, cell performance is expected to suffer considerably at high current densities due to their reduced electrical conductivity.

  7. Acoustic Effects of Hydrokinetic Tidal Turbines

    SciTech Connect (OSTI)

    Polagye, Brian

    2011-11-01

    This presentation from the Water Peer Review highlights one of the program's marine and hyrokinetics environmental projects to determine the likely acoustic effects from a tidal energy device.

  8. Milky Way mass and potential recovery using tidal streams in a realistic halo

    SciTech Connect (OSTI)

    Bonaca, Ana; Geha, Marla; Küpper, Andreas H. W.; Johnston, Kathryn V.; Diemand, Jürg; Hogg, David W.

    2014-11-01

    We present a new method for determining the Galactic gravitational potential based on forward modeling of tidal stellar streams. We use this method to test the performance of smooth and static analytic potentials in representing realistic dark matter halos, which have substructure and are continually evolving by accretion. Our FAST-FORWARD method uses a Markov Chain Monte Carlo algorithm to compare, in six-dimensional phase space, an 'observed' stream to models created in trial analytic potentials. We analyze a large sample of streams that evolved in the Via Lactea II (VL2) simulation, which represents a realistic Galactic halo potential. The recovered potential parameters are in agreement with the best fit to the global, present-day VL2 potential. However, merely assuming an analytic potential limits the dark matter halo mass measurement to an accuracy of 5%-20%, depending on the choice of analytic parameterization. Collectively, the mass estimates using streams from our sample reach this fundamental limit, but individually they can be highly biased. Individual streams can both under- and overestimate the mass, and the bias is progressively worse for those with smaller perigalacticons, motivating the search for tidal streams at galactocentric distances larger than 70 kpc. We estimate that the assumption of a static and smooth dark matter potential in modeling of the GD-1- and Pal5-like streams introduces an error of up to 50% in the Milky Way mass estimates.

  9. Uncovering CDM halo substructure with tidal streams

    E-Print Network [OSTI]

    R. A. Ibata; G. F. Lewis; M. J. Irwin

    2001-10-31

    Models for the formation and growth of structure in a cold dark matter dominated universe predict that galaxy halos should contain significant substructure. Studies of the Milky Way, however, have yet to identify the expected few hundred sub-halos with masses greater than about 10^6 Msun. Here we propose a test for the presence of sub-halos in the halos of galaxies. We show that the structure of the tidal tails of ancient globular clusters is very sensitive to heating by repeated close encounters with the massive dark sub-halos. We discuss the detection of such an effect in the context of the next generation of astrometric missions, and conclude that it should be easily detectable with the GAIA dataset. The finding of a single extended cold stellar stream from a globular cluster would support alternative theories, such as self-interacting dark matter, that give rise to smoother halos.

  10. 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 Center Home Page| Open Energy Information Serbia-EnhancingEt Al., 2013)Open Energy Information ThreeTianDi GrowthTibagiTidal

  11. A Linear Parabolic Trough Solar Collector Performance Model 

    E-Print Network [OSTI]

    Qu, M.; Archer, D.; Masson, S.

    2006-01-01

    A performance model has been programmed for solar thermal collector based on a linear, tracking parabolic trough reflector focused on a surface-treated metallic pipe receiver enclosed in an evacuated transparent tube: a ...

  12. PI CONTROLLERS PERFORMANCES FOR A PROCESS MODEL WITH VARYING DELAY

    E-Print Network [OSTI]

    the obtained performances on a simplified hy- drodesulfurization process model we use as test case. 2 PI by a relay feedback as shown in [1]. Ziegler and Nichols then studied on a simple real process

  13. Centrifuge Modelling of the Performance of Liquefaction Mitigation Measures for

    E-Print Network [OSTI]

    Centrifuge Modelling of the Performance of Liquefaction Mitigation Measures for Shallow Foundations Centrifuge Stored Angular Momentum Actuator Equivalent Shear Beam Container Automatic Sand Pourer Hostun Sand Methylcellulose 3 #12;Experimental Techniques and Materials 10 m Turner Beam Centrifuge Stored

  14. Turbulence and internal waves in tidal flow over topography

    E-Print Network [OSTI]

    Gayen, Bishakhdatta

    2012-01-01

    M. C. 2006 An estimate of tidal energy lost to turbulence atcant loss of low-mode tidal energy at 28.9 ? . Geophys. Res.of turbulent kinetic energy over a tidal cycle. Maximum T KE

  15. Dispersion and Tidal Dynamics of Channel-Shoal Estuaries

    E-Print Network [OSTI]

    Holleman, Christopher Dean

    2013-01-01

    San Pablo Bay: ? M 2 and tidal energy flux for the hNS0? M 2 and tidal energy flux for hNS0. . . . . . . . . . .areas dissipate incident tidal energy, countering the added

  16. Models used to assess the performance of photovoltaic systems.

    SciTech Connect (OSTI)

    Stein, Joshua S.; Klise, Geoffrey T.

    2009-12-01

    This report documents the various photovoltaic (PV) performance models and software developed and utilized by researchers at Sandia National Laboratories (SNL) in support of the Photovoltaics and Grid Integration Department. In addition to PV performance models, hybrid system and battery storage models are discussed. A hybrid system using other distributed sources and energy storage can help reduce the variability inherent in PV generation, and due to the complexity of combining multiple generation sources and system loads, these models are invaluable for system design and optimization. Energy storage plays an important role in reducing PV intermittency and battery storage models are used to understand the best configurations and technologies to store PV generated electricity. Other researcher's models used by SNL are discussed including some widely known models that incorporate algorithms developed at SNL. There are other models included in the discussion that are not used by or were not adopted from SNL research but may provide some benefit to researchers working on PV array performance, hybrid system models and energy storage. The paper is organized into three sections to describe the different software models as applied to photovoltaic performance, hybrid systems, and battery storage. For each model, there is a description which includes where to find the model, whether it is currently maintained and any references that may be available. Modeling improvements underway at SNL include quantifying the uncertainty of individual system components, the overall uncertainty in modeled vs. measured results and modeling large PV systems. SNL is also conducting research into the overall reliability of PV systems.

  17. Symposium on Human Performance Modeling Wayne D. Gray (Organizer)

    E-Print Network [OSTI]

    Gray, Wayne

    -TG) of the Human Factors & Ergonomics Society. Three Research Talks and a Panel Discussion were presented. Each The Human Performance Modeling Technical Group (HPM-TG) of the Human Factors and Ergonomics Society (HFES by Pew (2007, 2008). Technical Talks An Accessible Cognitive Modeling Tool for Evaluation of Pilot

  18. Accurate CUDA Performance Modeling for Sparse Matrix-Vector Multiplication

    E-Print Network [OSTI]

    Wang, Liqiang

    of 8 widely-used testing matrices on NVIDIA Tesla C2050, the execution times predicted by our model of instrumenting, benchmark matrices are generated according to a GPU's architecture features, then Sp by NVIDIA [1] and NVIDIA Tesla C2050 for our performance modeling and experiments. However, the proposed

  19. Tidal deformations of a spinning compact object

    E-Print Network [OSTI]

    Pani, Paolo; Maselli, Andrea; Ferrari, Valeria

    2015-01-01

    The deformability of a compact object induced by a perturbing tidal field is encoded in the tidal Love numbers, which depend sensibly on the object's internal structure. These numbers are known only for static, spherically-symmetric objects. As a first step to compute the tidal Love numbers of a spinning compact star, here we extend powerful perturbative techniques to compute the exterior geometry of a spinning object distorted by an axisymmetric tidal field to second order in the angular momentum. The spin of the object introduces couplings between electric and magnetic deformations and new classes of induced Love numbers emerge. For example, a spinning object immersed in a quadrupolar, electric tidal field can acquire some induced mass, spin, quadrupole, octupole and hexadecapole moments to second order in the spin. The deformations are encoded in a set of inhomogeneous differential equations which, remarkably, can be solved analytically in vacuum. We discuss certain subtleties in defining the multipole mom...

  20. Analytic models of supercomputer performance in multiprogramming environments

    SciTech Connect (OSTI)

    Menasce, D.A. ); Almeida, V.A.F. )

    1989-01-01

    Supercomputers run multiprogrammed time-sharing operating systems, so their facilities can be shared by many local and remote users. Therefore, it is important to be able to assess the performance of supercomputers and multiprogrammed environments. Analytic models based on Queueing Networks (QNs) and Stochastic Petri Nets (SPNs) are used in this paper with two purposes: to evaluate the performance of supercomputers in multiprogrammed environments, and to compare, performance-wise, conventional supercomputer architectures with a novel architecture proposed here. It is shown, with the aid of the analytic models, that the proposed architecture is preferable performance-wise over the existing conventional supercomputer architectures. A three-level workload characterization model for supercomputers is presented. Input data for the numerical examples discussed here are extracted from the well-known Los Alamos benchmark, and the results are validated by simulation.

  1. Better Buildings Neighborhood Program Business Models Guide: Home Performance Contractor Business Model

    Broader source: Energy.gov [DOE]

    The home performance contractor model walks through the “one-stop-shop” model for home energy upgrades. It illustrates both the opportunities and barriers for starting as a home performance contractor company from the beginning, rather than expanding from an existing model, such as a remodeler.

  2. OUTDOOR PV PERFORMANCE EVALUATION OF THREE DIFFERENT MODELS: SINGLE-DIODE, SAPM AND LOSS FACTOR MODEL

    E-Print Network [OSTI]

    OUTDOOR PV PERFORMANCE EVALUATION OF THREE DIFFERENT MODELS: SINGLE-DIODE, SAPM AND LOSS FACTOR.steveransome.com ABSTRACT: This study examines the accuracy and value of three different PV module performance modeling. The equivalent circuit diode models (e.g., PVsyst, PV*SOL, CEC, etc.) are popular, but include technology

  3. Human performance modeling for system of systems analytics :soldier fatigue.

    SciTech Connect (OSTI)

    Lawton, Craig R.; Campbell, James E.; Miller, Dwight Peter

    2005-10-01

    The military has identified Human Performance Modeling (HPM) as a significant requirement and challenge of future systems modeling and analysis initiatives as can be seen in the Department of Defense's (DoD) Defense Modeling and Simulation Office's (DMSO) Master Plan (DoD 5000.59-P 1995). To this goal, the military is currently spending millions of dollars on programs devoted to HPM in various military contexts. Examples include the Human Performance Modeling Integration (HPMI) program within the Air Force Research Laboratory, which focuses on integrating HPMs with constructive models of systems (e.g. cockpit simulations) and the Navy's Human Performance Center (HPC) established in September 2003. Nearly all of these initiatives focus on the interface between humans and a single system. This is insufficient in the era of highly complex network centric SoS. This report presents research and development in the area of HPM in a system-of-systems (SoS). Specifically, this report addresses modeling soldier fatigue and the potential impacts soldier fatigue can have on SoS performance.

  4. Tidal deformations of a spinning compact object

    E-Print Network [OSTI]

    Paolo Pani; Leonardo Gualtieri; Andrea Maselli; Valeria Ferrari

    2015-06-30

    The deformability of a compact object induced by a perturbing tidal field is encoded in the tidal Love numbers, which depend sensibly on the object's internal structure. These numbers are known only for static, spherically-symmetric objects. As a first step to compute the tidal Love numbers of a spinning compact star, here we extend powerful perturbative techniques to compute the exterior geometry of a spinning object distorted by an axisymmetric tidal field to second order in the angular momentum. The spin of the object introduces couplings between electric and magnetic deformations and new classes of induced Love numbers emerge. For example, a spinning object immersed in a quadrupolar, electric tidal field can acquire some induced mass, spin, quadrupole, octupole and hexadecapole moments to second order in the spin. The deformations are encoded in a set of inhomogeneous differential equations which, remarkably, can be solved analytically in vacuum. We discuss certain subtleties in defining the multipole moments of the central object, which are due to the difficulty in separating the tidal field from the linear response of the object in the solution. By extending the standard procedure to identify the linear response in the static case, we prove analytically that the Love numbers of a Kerr black hole remain zero to second order in the spin. As a by-product, we provide the explicit form for a slowly-rotating, tidally-deformed Kerr black hole to quadratic order in the spin, and discuss its geodesic and geometrical properties.

  5. Infrared emission from tidal disruption events --- probing the pc-scale dust content around galactic nuclei

    E-Print Network [OSTI]

    Lu, Wenbin; Evans, Neal J

    2015-01-01

    Recent UV-optical surveys have been successful in finding tidal disruption events (TDEs), in which a star is tidally disrupted by a supermassive black hole (BH). These TDEs release a huge amount of radiation energy ~ 10^51-52 erg into the circum-nuclear medium. If the medium is dusty, most of the radiation energy will be absorbed by dust grains within ~ 1 pc from the BH and re-radiated in the infrared. We calculate the dust emission lightcurve from a 1-D radiative transfer model, taking into account the time-dependent heating, cooling and sublimation of dust grains. We show that the dust emission peaks at 3-10 microns and has typical luminosities ~ 10^42-43 erg/s (with sky covering factor of dusty clouds ranging from 0.1-1). This is detectable by current generation of telescopes. In the near future, James Webb Space Telescope will be able to perform photometric and spectroscopic measurements, in which silicate or polycyclic aromatic hydrocarbon (PAH) features may be found. Observations at rest-frame wavelengt...

  6. PORFLOW Modeling Supporting The H-Tank Farm Performance Assessment

    SciTech Connect (OSTI)

    Jordan, J. M.; Flach, G. P.; Westbrook, M. L.

    2012-08-31

    Numerical simulations of groundwater flow and contaminant transport in the vadose and saturated zones have been conducted using the PORFLOW code in support of an overall Performance Assessment (PA) of the H-Tank Farm. This report provides technical detail on selected aspects of PORFLOW model development and describes the structure of the associated electronic files. The PORFLOW models for the H-Tank Farm PA, Rev. 1 were updated with grout, solubility, and inventory changes. The aquifer model was refined. In addition, a set of flow sensitivity runs were performed to allow flow to be varied in the related probabilistic GoldSim models. The final PORFLOW concentration values are used as input into a GoldSim dose calculator.

  7. Cost and Performance Model for Redox Flow Batteries

    SciTech Connect (OSTI)

    Viswanathan, Vilayanur V.; Crawford, Aladsair J.; Stephenson, David E.; Kim, Soowhan; Wang, Wei; Li, Bin; Coffey, Greg W.; Thomsen, Edwin C.; Graff, Gordon L.; Balducci, Patrick J.; Kintner-Meyer, Michael CW; Sprenkle, Vincent L.

    2014-02-01

    A cost model was developed for all vanadium and iron-vanadium redox flow batteries. Electrochemical performance modeling was done to estimate stack performance at various power densities as a function of state of charge. This was supplemented with a shunt current model and a pumping loss model to estimate actual system efficiency. The operating parameters such as power density, flow rates and design parameters such as electrode aspect ratio, electrolyte flow channel dimensions were adjusted to maximize efficiency and minimize capital costs. Detailed cost estimates were obtained from various vendors to calculate cost estimates for present, realistic and optimistic scenarios. The main drivers for cost reduction for various chemistries were identified as a function of the energy to power ratio of the storage system. Levelized cost analysis further guided suitability of various chemistries for different applications.

  8. ADVANCED WUFI COMPUTER MODELING WORKSHOP FOR WALL DESIGN AND PERFORMANCE

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    TRANSFER IN BUILDING ENVELOPES) Napa, CA, January 30 - February 1, 2012 WUFI/ORNL1 Program made availableADVANCED WUFI COMPUTER MODELING WORKSHOP FOR WALL DESIGN AND PERFORMANCE (HEAT AND MOISTURE-Institut für Bauphysik (IBP) and co-sponsored by the National Institute of Building Sciences (NIBS)/ Building

  9. Issues in Performance Modeling of Applications with Garbage Collection

    E-Print Network [OSTI]

    collector (GC) inside Sun Java Virtual Machine. Although its algorithm is reasonably well documented [9 Vodárenskou vezí 2, 182 07 Prague, Czech Republic ABSTRACT Even though garbage collectors are incorporated in many service oriented systems, service performance models typi- cally treat garbage collector overhead

  10. Panorama: Modeling The Performance of Scientific Workflows Ewa Deelman1

    E-Print Network [OSTI]

    Deelman, Ewa

    Monitoring of Extreme Science Work- flows". The development of the neutron scattering simulation workflow performance of complex scientific workflows is to integrate extreme-scale systems testbed exper- imentation, structured analytical modeling and par- allel systems simulation into a comprehensive work- flow framework

  11. A Model of Extranet Implementation Success Effects on Business Performance

    E-Print Network [OSTI]

    Wu, Qinglin

    A Model of Extranet Implementation Success Effects on Business Performance Sanna M. Kallioranta Ph and Justification The eBusiness revolution is impossible to ignore. It has transformed businesses in virtually every and services, and eBusiness has transformed the way companies interact with customers, partners and employees

  12. Fourier and autocorrelation analysis of estuarine tidal rhythmites, lower Breathitt Formation (Pennsylvania), eastern Kentucky, USA

    SciTech Connect (OSTI)

    Martino, R.L.; Sanderson, D.D. (Marshall Univ., Huntington, WV (United States))

    1993-01-01

    Outcrops of the Pennsylvanian Breathitt Formation in eastern Kentucky reveal a rhythmic pattern of siliciclastic sedimentation in a marginal marine coastal setting. A 15-23 m thick stratigraphic interval of thinly interbedded, fine sandstone and shale displays tidally generated features such as flaser and wavy current ripple bedding, bipolar paleocurrents, and cyclic thickening and thinning of mud-draped sandstone layers. A statistical analysis of sand layer thickness was carried out using shale partings as bounding surfaces for the individual sand units. Fourier and autocorrelation analyses were performed on two vertical sequences containing a total of over 2,100 layers. The results reveal the presence of four cycles of thickness variation. First-order cycles consist of alternating thick-thin sand layers. These daily couplets may reflect unequal flood and ebb currents during a single tidal cycle or dominant and subordinate tidal deposits in an ebb or flood dominated semidiurnal or mixed system. Second-order cycles typically consist of 11-14 sand layers and reflect spring-neap variations in tidal range and current velocities. Third-order cycles are usually composed of 24-35 layers and are formed in response to monthly variations in tidal range resulting from the ellipticity of the moon's orbit. Fourth-order cycles generally contain about 150 layers (range, 100-166) and were caused by seasonal maxima in tidal range associated with the solstice (winter, summer) and seasonal minima associated with the equinox (spring, fall).

  13. A Programming Model Performance Study Using the NAS Parallel Benchmarks

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Shan, Hongzhang; Blagojevi?, Filip; Min, Seung-Jai; Hargrove, Paul; Jin, Haoqiang; Fuerlinger, Karl; Koniges, Alice; Wright, Nicholas J.

    2010-01-01

    Harnessing the power of multicore platforms is challenging due to the additional levels of parallelism present. In this paper we use the NAS Parallel Benchmarks to study three programming models, MPI, OpenMP and PGAS to understand their performance and memory usage characteristics on current multicore architectures. To understand these characteristics we use the Integrated Performance Monitoring tool and other ways to measure communication versus computation time, as well as the fraction of the run time spent in OpenMP. The benchmarks are run on two different Cray XT5 systems and an Infiniband cluster. Our results show that in general the threemore »programming models exhibit very similar performance characteristics. In a few cases, OpenMP is significantly faster because it explicitly avoids communication. For these particular cases, we were able to re-write the UPC versions and achieve equal performance to OpenMP. Using OpenMP was also the most advantageous in terms of memory usage. Also we compare performance differences between the two Cray systems, which have quad-core and hex-core processors. We show that at scale the performance is almost always slower on the hex-core system because of increased contention for network resources.« less

  14. 12th Annual Wave & Tidal 2015

    Broader source: Energy.gov [DOE]

    The UK is currently the undisputed global leader in marine energy, with more wave and tidal stream devices installed than the rest of the world combined. This leading position is built on an...

  15. Reference Manual for the System Advisor Model's Wind Power Performance Model

    SciTech Connect (OSTI)

    Freeman, J.; Jorgenson, J.; Gilman, P.; Ferguson, T.

    2014-08-01

    This manual describes the National Renewable Energy Laboratory's System Advisor Model (SAM) wind power performance model. The model calculates the hourly electrical output of a single wind turbine or of a wind farm. The wind power performance model requires information about the wind resource, wind turbine specifications, wind farm layout (if applicable), and costs. In SAM, the performance model can be coupled to one of the financial models to calculate economic metrics for residential, commercial, or utility-scale wind projects. This manual describes the algorithms used by the wind power performance model, which is available in the SAM user interface and as part of the SAM Simulation Core (SSC) library, and is intended to supplement the user documentation that comes with the software.

  16. MODELING THE PERFORMANCE OF HIGH BURNUP THORIA AND URANIA PWR FUEL

    E-Print Network [OSTI]

    Long, Y.

    Fuel performance models have been developed to assess the performance of ThO[subscript 2]-UO[subscript 2]

  17. PHARAO Laser Source Flight Model: Design and Performances

    E-Print Network [OSTI]

    Lévèque, Thomas; Esnault, François-Xavier; Delaroche, Christophe; Massonnet, Didier; Grosjean, Olivier; Buffe, Fabrice; Torresi, Patrizia; Bomer, Thierry; Pichon, Alexandre; Béraud, Pascal; Lelay, Jean-Pierre; Thomin, Stéphane; Laurent, Philippe

    2015-01-01

    In this paper, we describe the design and the main performances of the PHARAO laser source flight model. PHARAO is a laser cooled cesium clock specially designed for operation in space and the laser source is one of the main sub-systems. The flight model presented in this work is the first remote-controlled laser system designed for spaceborne cold atom manipulation. The main challenges arise from mechanical compatibility with space constraints, which impose a high level of compactness, a low electric power consumption, a wide range of operating temperature and a vacuum environment. We describe the main functions of the laser source and give an overview of the main technologies developed for this instrument. We present some results of the qualification process. The characteristics of the laser source flight model, and their impact on the clock performances, have been verified in operational conditions.

  18. A New Model to Simulate Energy Performance of VRF Systems

    SciTech Connect (OSTI)

    Hong, Tianzhen; Pang, Xiufeng; Schetrit, Oren; Wang, Liping; Kasahara, Shinichi; Yura, Yoshinori; Hinokuma, Ryohei

    2014-03-30

    This paper presents a new model to simulate energy performance of variable refrigerant flow (VRF) systems in heat pump operation mode (either cooling or heating is provided but not simultaneously). The main improvement of the new model is the introduction of the evaporating and condensing temperature in the indoor and outdoor unit capacity modifier functions. The independent variables in the capacity modifier functions of the existing VRF model in EnergyPlus are mainly room wet-bulb temperature and outdoor dry-bulb temperature in cooling mode and room dry-bulb temperature and outdoor wet-bulb temperature in heating mode. The new approach allows compliance with different specifications of each indoor unit so that the modeling accuracy is improved. The new VRF model was implemented in a custom version of EnergyPlus 7.2. This paper first describes the algorithm for the new VRF model, which is then used to simulate the energy performance of a VRF system in a Prototype House in California that complies with the requirements of Title 24 ? the California Building Energy Efficiency Standards. The VRF system performance is then compared with three other types of HVAC systems: the Title 24-2005 Baseline system, the traditional High Efficiency system, and the EnergyStar Heat Pump system in three typical California climates: Sunnyvale, Pasadena and Fresno. Calculated energy savings from the VRF systems are significant. The HVAC site energy savings range from 51 to 85percent, while the TDV (Time Dependent Valuation) energy savings range from 31 to 66percent compared to the Title 24 Baseline Systems across the three climates. The largest energy savings are in Fresno climate followed by Sunnyvale and Pasadena. The paper discusses various characteristics of the VRF systems contributing to the energy savings. It should be noted that these savings are calculated using the Title 24 prototype House D under standard operating conditions. Actual performance of the VRF systems for real houses under real operating conditions will vary.

  19. EQUATORIAL SUPERROTATION ON TIDALLY LOCKED EXOPLANETS

    SciTech Connect (OSTI)

    Showman, Adam P. [Department of Planetary Sciences and Lunar and Planetary Laboratory, University of Arizona, 1629 University Blvd., Tucson, AZ 85721 (United States); Polvani, Lorenzo M., E-mail: showman@lpl.arizona.edu [Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY (United States)

    2011-09-01

    The increasing richness of exoplanet observations has motivated a variety of three-dimensional (3D) atmospheric circulation models of these planets. Under strongly irradiated conditions, models of tidally locked, short-period planets (both hot Jupiters and terrestrial planets) tend to exhibit a circulation dominated by a fast eastward, or 'superrotating', jet stream at the equator. When the radiative and advection timescales are comparable, this phenomenon can cause the hottest regions to be displaced eastward from the substellar point by tens of degrees longitude. Such an offset has been subsequently observed on HD 189733b, supporting the possibility of equatorial jets on short-period exoplanets. Despite its relevance, however, the dynamical mechanisms responsible for generating the equatorial superrotation in such models have not been identified. Here, we show that the equatorial jet results from the interaction of the mean flow with standing Rossby waves induced by the day-night thermal forcing. The strong longitudinal variations in radiative heating-namely intense dayside heating and nightside cooling-trigger the formation of standing, planetary-scale equatorial Rossby and Kelvin waves. The Rossby waves develop phase tilts that pump eastward momentum from high latitudes to the equator, thereby inducing equatorial superrotation. We present an analytic theory demonstrating this mechanism and explore its properties in a hierarchy of one-layer (shallow-water) calculations and fully 3D models. The wave-mean-flow interaction produces an equatorial jet whose latitudinal width is comparable to that of the Rossby waves, namely the equatorial Rossby deformation radius modified by radiative and frictional effects. For conditions typical of synchronously rotating hot Jupiters, this length is comparable to a planetary radius, explaining the broad scale of the equatorial jet obtained in most hot-Jupiter models. Our theory illuminates the dependence of the equatorial jet speed on forcing amplitude, strength of friction, and other parameters, as well as the conditions under which jets can form at all.

  20. Correlation between human observer performance and model observer performance in differential phase contrast CT

    SciTech Connect (OSTI)

    Li, Ke; Garrett, John; Chen, Guang-Hong

    2013-11-15

    Purpose: With the recently expanding interest and developments in x-ray differential phase contrast CT (DPC-CT), the evaluation of its task-specific detection performance and comparison with the corresponding absorption CT under a given radiation dose constraint become increasingly important. Mathematical model observers are often used to quantify the performance of imaging systems, but their correlations with actual human observers need to be confirmed for each new imaging method. This work is an investigation of the effects of stochastic DPC-CT noise on the correlation of detection performance between model and human observers with signal-known-exactly (SKE) detection tasks.Methods: The detectabilities of different objects (five disks with different diameters and two breast lesion masses) embedded in an experimental DPC-CT noise background were assessed using both model and human observers. The detectability of the disk and lesion signals was then measured using five types of model observers including the prewhitening ideal observer, the nonprewhitening (NPW) observer, the nonprewhitening observer with eye filter and internal noise (NPWEi), the prewhitening observer with eye filter and internal noise (PWEi), and the channelized Hotelling observer (CHO). The same objects were also evaluated by four human observers using the two-alternative forced choice method. The results from the model observer experiment were quantitatively compared to the human observer results to assess the correlation between the two techniques.Results: The contrast-to-detail (CD) curve generated by the human observers for the disk-detection experiments shows that the required contrast to detect a disk is inversely proportional to the square root of the disk size. Based on the CD curves, the ideal and NPW observers tend to systematically overestimate the performance of the human observers. The NPWEi and PWEi observers did not predict human performance well either, as the slopes of their CD curves tended to be steeper. The CHO generated the best quantitative agreement with human observers with its CD curve overlapping with that of human observer. Statistical equivalence between CHO and humans can be claimed within 11% of the human observer results, including both the disk and lesion detection experiments.Conclusions: The model observer method can be used to accurately represent human observer performance with the stochastic DPC-CT noise for SKE tasks with sizes ranging from 8 to 128 pixels. The incorporation of the anatomical noise remains to be studied.

  1. Instruction-level performance modeling and characterization of multimedia applications

    SciTech Connect (OSTI)

    Luo, Y.; Cameron, K.W.

    1999-06-01

    One of the challenges for characterizing and modeling realistic multimedia applications is the lack of access to source codes. On-chip performance counters effectively resolve this problem by monitoring run-time behaviors at the instruction-level. This paper presents a novel technique of characterizing and modeling workloads at the instruction level for realistic multimedia applications using hardware performance counters. A variety of instruction counts are collected from some multimedia applications, such as RealPlayer, GSM Vocoder, MPEG encoder/decoder, and speech synthesizer. These instruction counts can be used to form a set of abstract characteristic parameters directly related to a processor`s architectural features. Based on microprocessor architectural constraints and these calculated abstract parameters, the architectural performance bottleneck for a specific application can be estimated. Meanwhile, the bottleneck estimation can provide suggestions about viable architectural/functional improvement for certain workloads. The biggest advantage of this new characterization technique is a better understanding of processor utilization efficiency and architectural bottleneck for each application. This technique also provides predictive insight of future architectural enhancements and their affect on current codes. In this paper the authors also attempt to model architectural effect on processor utilization without memory influence. They derive formulas for calculating CPI{sub 0}, CPI without memory effect, and they quantify utilization of architectural parameters. These equations are architecturally diagnostic and predictive in nature. Results provide promise in code characterization, and empirical/analytical modeling.

  2. Large-Eddy Simulation Study of Wake Propagation and Power Production in an Array of Tidal-Current Turbines: Preprint

    SciTech Connect (OSTI)

    Churchfield, M. J.; Li, Y.; Moriarty, P. J.

    2012-07-01

    This paper presents our initial work in performing large-eddy simulations of tidal turbine array flows. First, a horizontally-periodic precursor simulation is performed to create turbulent flow data. Then that data is used as inflow into a tidal turbine array two rows deep and infinitely wide. The turbines are modeled using rotating actuator lines, and the finite-volume method is used to solve the governing equations. In studying the wakes created by the turbines, we observed that the vertical shear of the inflow combined with wake rotation causes lateral wake asymmetry. Also, various turbine configurations are simulated, and the total power production relative to isolated turbines is examined. Staggering consecutive rows of turbines in the simulated configurations allows the greatest efficiency using the least downstream row spacing. Counter-rotating consecutive downstream turbines in a non-staggered array shows a small benefit. This work has identified areas for improvement, such as the use of a larger precursor domain to better capture elongated turbulent structures, the inclusion of salinity and temperature equations to account for density stratification and its effect on turbulence, improved wall shear stress modelling, and the examination of more array configurations.

  3. Large-Eddy Simulation Study of Wake Propagation and Power Production in an Array of Tidal-Current Turbines: Preprint

    SciTech Connect (OSTI)

    Churchfield, M. J.; Li, Y.; Moriarty, P. J.

    2011-07-01

    This paper presents our initial work in performing large-eddy simulations of tidal turbine array flows. First, a horizontally-periodic precursor simulation is performed to create turbulent flow data. Then that data is used to determine the inflow into a tidal turbine array two rows deep and infinitely wide. The turbines are modeled using rotating actuator lines, and the finite-volume method is used to solve the governing equations. In studying the wakes created by the turbines, we observed that the vertical shear of the inflow combined with wake rotation causes lateral wake asymmetry. Also, various turbine configurations are simulated, and the total power production relative to isolated turbines is examined. Staggering consecutive rows of turbines in the simulated configurations allows the greatest efficiency using the least downstream row spacing. Counter-rotating consecutive downstream turbines in a non-staggered array shows a small benefit. This work has identified areas for improvement, such as the use of a larger precursor domain to better capture elongated turbulent structures, the inclusion of salinity and temperature equations to account for density stratification and its effect on turbulence, improved wall shear stress modeling, and the examination of more array configurations.

  4. Duct thermal performance models for large commercial buildings

    SciTech Connect (OSTI)

    Wray, Craig P.

    2003-10-01

    Despite the potential for significant energy savings by reducing duct leakage or other thermal losses from duct systems in large commercial buildings, California Title 24 has no provisions to credit energy-efficient duct systems in these buildings. A substantial reason is the lack of readily available simulation tools to demonstrate the energy-saving benefits associated with efficient duct systems in large commercial buildings. The overall goal of the Efficient Distribution Systems (EDS) project within the PIER High Performance Commercial Building Systems Program is to bridge the gaps in current duct thermal performance modeling capabilities, and to expand our understanding of duct thermal performance in California large commercial buildings. As steps toward this goal, our strategy in the EDS project involves two parts: (1) developing a whole-building energy simulation approach for analyzing duct thermal performance in large commercial buildings, and (2) using the tool to identify the energy impacts of duct leakage in California large commercial buildings, in support of future recommendations to address duct performance in the Title 24 Energy Efficiency Standards for Nonresidential Buildings. The specific technical objectives for the EDS project were to: (1) Identify a near-term whole-building energy simulation approach that can be used in the impacts analysis task of this project (see Objective 3), with little or no modification. A secondary objective is to recommend how to proceed with long-term development of an improved compliance tool for Title 24 that addresses duct thermal performance. (2) Develop an Alternative Calculation Method (ACM) change proposal to include a new metric for thermal distribution system efficiency in the reporting requirements for the 2005 Title 24 Standards. The metric will facilitate future comparisons of different system types using a common ''yardstick''. (3) Using the selected near-term simulation approach, assess the impacts of duct system improvements in California large commercial buildings, over a range of building vintages and climates. This assessment will provide a solid foundation for future efforts that address the energy efficiency of large commercial duct systems in Title 24. This report describes our work to address Objective 1, which includes a review of past modeling efforts related to duct thermal performance, and recommends near- and long-term modeling approaches for analyzing duct thermal performance in large commercial buildings.

  5. Cross-industry Performance Modeling: Toward Cooperative Analysis

    SciTech Connect (OSTI)

    Reece, Wendy Jane; Blackman, Harold Stabler

    1998-10-01

    One of the current unsolved problems in human factors is the difficulty in acquiring information from lessons learned and data collected among human performance analysts in different domains. There are several common concerns and generally accepted issues of importance for human factors, psychology and industry analysts of performance and safety. Among these are the need to incorporate lessons learned in design, to carefully consider implementation of new designs and automation, and the need to reduce human performance-based contributions to risk. In spite of shared concerns, there are several roadblocks to widespread sharing of data and lessons learned from operating experience and simulation, including the fact that very few publicly accessible data bases exist (Gertman & Blackman, 1994, and Kirwan, 1997). There is a need to draw together analysts and analytic methodologies to comprise a centralized source of data with sufficient detail to be meaningful while ensuring source anonymity. We propose that a generic source of performance data and a multi-domain data store may provide the first steps toward cooperative performance modeling and analysis across industries.

  6. Dispersion mechanisms of a tidal river junction in the Sacramento–San Joaquin Delta, California

    SciTech Connect (OSTI)

    Gleichauf, Karla T.; Wolfram, Philip J.; Monsen, Nancy E.; Fringer, Oliver B.; Monismith, Stephen G.

    2014-12-17

    In branching channel networks, such as in the Sacramento–San Joaquin River Delta, junction flow dynamics contribute to dispersion of ecologically important entities such as fish, pollutants, nutrients, salt, sediment, and phytoplankton. Flow transport through a junction largely arises from velocity phasing in the form of divergent flow between junction channels for a portion of the tidal cycle. Field observations in the Georgiana Slough junction, which is composed of the North and South Mokelumne rivers, Georgiana Slough, and the Mokelumne River, show that flow phasing differences between these rivers arise from operational, riverine, and tidal forcing. A combination of Acoustic Doppler Current Profile (ADCP) boat transecting and moored ADCPs over a spring–neap tidal cycle (May to June 2012) monitored the variability of spatial and temporal velocity, respectively. Two complementary drifter studies enabled assessment of local transport through the junction to identify small-scale intrajunction dynamics. We supplemented field results with numerical simulations using the SUNTANS model to demonstrate the importance of phasing offsets for junction transport and dispersion. Different phasing of inflows to the junction resulted in scalar patchiness that is characteristic of MacVean and Stacey’s (2011) advective tidal trapping. Furthermore, we observed small-scale junction flow features including a recirculation zone and shear layer, which play an important role in intra-junction mixing over time scales shorter than the tidal cycle (i.e., super-tidal time scales). Thus, the study period spanned open- and closed-gate operations at the Delta Cross Channel. Synthesis of field observations and modeling efforts suggest that management operations related to the Delta Cross Channel can strongly affect transport in the Delta by modifying the relative contributions of tidal and riverine flows, thereby changing the junction flow phasing.

  7. Dispersion mechanisms of a tidal river junction in the Sacramento–San Joaquin Delta, California

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gleichauf, Karla T.; Wolfram, Philip J.; Monsen, Nancy E.; Fringer, Oliver B.; Monismith, Stephen G.

    2014-12-17

    In branching channel networks, such as in the Sacramento–San Joaquin River Delta, junction flow dynamics contribute to dispersion of ecologically important entities such as fish, pollutants, nutrients, salt, sediment, and phytoplankton. Flow transport through a junction largely arises from velocity phasing in the form of divergent flow between junction channels for a portion of the tidal cycle. Field observations in the Georgiana Slough junction, which is composed of the North and South Mokelumne rivers, Georgiana Slough, and the Mokelumne River, show that flow phasing differences between these rivers arise from operational, riverine, and tidal forcing. A combination of Acoustic Dopplermore »Current Profile (ADCP) boat transecting and moored ADCPs over a spring–neap tidal cycle (May to June 2012) monitored the variability of spatial and temporal velocity, respectively. Two complementary drifter studies enabled assessment of local transport through the junction to identify small-scale intrajunction dynamics. We supplemented field results with numerical simulations using the SUNTANS model to demonstrate the importance of phasing offsets for junction transport and dispersion. Different phasing of inflows to the junction resulted in scalar patchiness that is characteristic of MacVean and Stacey’s (2011) advective tidal trapping. Furthermore, we observed small-scale junction flow features including a recirculation zone and shear layer, which play an important role in intra-junction mixing over time scales shorter than the tidal cycle (i.e., super-tidal time scales). Thus, the study period spanned open- and closed-gate operations at the Delta Cross Channel. Synthesis of field observations and modeling efforts suggest that management operations related to the Delta Cross Channel can strongly affect transport in the Delta by modifying the relative contributions of tidal and riverine flows, thereby changing the junction flow phasing.« less

  8. MECHANICAL PROPERTY CHARACTERIZATIONS AND PERFORMANCE MODELING OF SOFC SEALS

    SciTech Connect (OSTI)

    Koeppel, Brian J.; Vetrano, John S.; Nguyen, Ba Nghiep; Sun, Xin; Khaleel, Mohammad A.

    2008-03-26

    This study provides modeling tools for the design of reliable seals for SOFC stacks. The work consists of 1) experimental testing to determine fundamental properties of SOFC sealing materials, and 2) numerical modeling of stacks and sealing systems. The material tests capture relevant temperature-dependent physical and mechanical data needed by the analytical models such as thermal expansion, strength, fracture toughness, and relaxation behavior for glass-ceramic seals and other materials. Testing has been performed on both homogenous specimens and multiple material assemblies to investigate the effect of interfacial reactions. A viscoelastic continuum damage model for a glass-ceramic seal was developed to capture the nonlinear behavior of this material at high temperatures. This model was implemented in the MSC MARC finite element code and was used for a detailed analysis of a planar SOFC stack under thermal cycling conditions. Realistic thermal loads for the stack were obtained using PNNL’s in-house multiphysics solver. The accumulated seal damage and component stresses were evaluated for multiple thermal loading cycles, and regions of high seal damage susceptible to cracking were identified. Selected test results, numerical model development, and analysis results will be presented.

  9. International Conference on Ocean Energy, 6 October, Bilbao Computational Analysis of Ducted Turbine Performance

    E-Print Network [OSTI]

    Pedersen, Tom

    Turbine Performance M. Shives1 and C. Crawford2 Dept. of Mechanical Engineering, University of Victoria turbine designs using computational fluid dynamics (CFD) simulation. Analytical model coefficients is proposed for the base pressure coefficient. Keywords: base-pressure, CFD, diffuser-augmented turbine, tidal

  10. A Bayesian Approach to Online Performance Modeling for Database Appliances using Gaussian Models

    E-Print Network [OSTI]

    Poupart, Pascal

    - tain peak performance for database management systems (DBMS), database administrators (DBAs) need. Accurately predicting response times of DBMS queries is necessary for a DBA to effectively achieve and highly accurate online DBMS performance model that is robust in the face of changing workloads, data

  11. Tidal Forces in Naked Singularity Backgrounds

    E-Print Network [OSTI]

    Goel, Akash; Roy, Pratim; Sarkar, Tapobrata

    2015-01-01

    The end stage of a gravitational collapse process can generically result in a black hole or a naked singularity. Here we undertake a comparative analysis of the nature of tidal forces in these backgrounds. The effect of such forces is generically exemplified by the Roche limit, which predicts the distance within which a celestial object disintegrates due to the tidal effects of a second more massive object. In this paper, using Fermi normal coordinates, we numerically compute the Roche limit for a class of non-rotating naked singularity backgrounds, and compare them with known results for Schwarzschild black holes. Our analysis indicates that there might be substantially large deviations in the magnitudes of tidal forces in naked singularity backgrounds, compared to the black hole cases. If observationally established, these can prove to be an effective indicator of the nature of the singularity at a galactic centre.

  12. 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

    2013-06-13

    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.

  13. Tidal analysis of water level in continental boreholes Version 2.2

    E-Print Network [OSTI]

    Brodsky, Emily

    tidal analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 4.3.1 The "credo

  14. An analytical model of axial compressor off-design performance

    SciTech Connect (OSTI)

    Camp, T.R.; Horlock, J.H. . Whittle Lab.)

    1994-07-01

    An analysis is presented of the off-design performance of multistage axial-flow compressors. It is based on an analytical solution, valid for small perturbations in operating conditions from the design point, and provides an insight into the effects of choices made during the compressor design process on performance and off-design stage matching. It is shown that the mean design value of stage loading coefficient ([psi] = [Delta]h[sub 0]/U[sup 2]) has a dominant effect on off-design performance, whereas the stage-wise distribution of stage loading coefficient and the design value of flow coefficient have little influence. The powerful effects of variable stator vanes on stage-matching are also demonstrated and these results are shown to agree well with previous work. The slope of the working line of a gas turbine engine, overlaid on overall compressor characteristics, is shown to have a strong effect on the off-design stage-matching through the compressor. The model is also used to analyze design changes to the compressor geometry and to show how errors in estimates of annulus blockage, decided during the design process, have less effect on compressor performance than has previously been thought.

  15. Tidal wave in 102Pd: Rotating condensate of up to seven d-bosons

    E-Print Network [OSTI]

    S. Frauendorf; M. A. Caprio; J. Sun

    2012-02-08

    The yrast states of even even vibrational and transitional nuclei are inter- preted as a rotating condensate of interacting d-bosons and the corresponding semi-classical tidal wave concept. A simple experimental manifestation of the anharmonicity caused by the boson interaction is found. The interpretation is substantiated by calculations based on the Collective Model and the Cranking Model.

  16. 2/27/2001 Systems Modeling -Spring 2001 1 Availability and Performability

    E-Print Network [OSTI]

    Browne, James C.

    2/27/2001 Systems Modeling - Spring 2001 1 Availability and Performability Coverage Definitions State Models Reliability Block Diagrams Success Diagrams Fault Trees Availability Performability Reward Rates Representations Examples #12;2/27/2001 Systems Modeling - Spring 2001 2 Availability

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

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

    project documented in this report created a national database of tidal stream energy potential, as well as a GIS tool usable by industry in order to accelerate the market for tidal...

  18. 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 numerical framework based on an energy-con- serving Arakawa C-grid discretization could be applied to ocean models. Tidal simulations are much more manageable that full-fledged OGCM climate simulations, being

  19. Detection of Gravitational Wave Emission by Supermassive Black Hole Binaries Through Tidal Disruption Flares

    E-Print Network [OSTI]

    Hayasaki, Kimitake

    2015-01-01

    Galaxy mergers produce binaries of supermassive black holes, which emit gravitational waves prior to their coalescence. We perform three-dimensional hydrodynamic simulations to study the tidal disruption of stars by such a binary in the final centuries of its life. We find that the gas stream of the stellar debris moves chaotically in the binary potential and forms accretion disks around both black holes. The accretion light curve is modulated over the binary orbital period owing to relativistic beaming. This periodic signal allows to detect the decay of the binary orbit due to gravitational wave emission by observing two tidal disruption events that are separated by more than a decade.

  20. Tidal networks 2. Watershed delineation and comparative network morphology

    E-Print Network [OSTI]

    Fagherazzi, Sergio

    of three, we quantify various tidal network properties including common power law relationships which have common power law relationships quantified for terrestrial systems to tidal systems and use these analysesTidal networks 2. Watershed delineation and comparative network morphology Andrea Rinaldo,1 Sergio

  1. Enhancing Electrical Supply by Pumped Storage in Tidal Lagoons

    E-Print Network [OSTI]

    MacKay, David J.C.

    to demand into high­value demand­following power; and second, it can simultaneously serve as a tidal powerEnhancing Electrical Supply by Pumped Storage in Tidal Lagoons David J.C. MacKay Cavendish/3/07 Summary The principle that the net energy delivered by a tidal pool can be increased by pumping extra

  2. Rotational stability of tidally deformed planetary I. Matsuyama1

    E-Print Network [OSTI]

    Nimmo, Francis

    Rotational stability of tidally deformed planetary bodies I. Matsuyama1 and F. Nimmo2 Received 11 consider the true polar wander (rotational variations driven by mass redistribution) of tidally deformed planetary bodies. The rotation pole of bodies without tidal deformation is stabilized by the component

  3. TIDAL FRESHWATER WETLANDS OF THE MID-ATLANTIC AND

    E-Print Network [OSTI]

    Fabrizio, Mary C.

    Chapter 14 TIDAL FRESHWATER WETLANDS OF THE MID-ATLANTIC AND SOUTHEASTERN UNITED STATES James E Jensen& Aat Barendregt 7. Animal communities in North American tidal fresh- water wetlands Christopher W Struyf, Tom Maris, Tom Cox & Patrick Meire 12. Carbon flows, nutrient cycling, and food webs in tidal

  4. 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)

    2011-08-01

    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}.

  5. Dissecting the pressure field in tidal flow

    E-Print Network [OSTI]

    Dissecting the pressure field in tidal flow past a headland: When is form drag "real?" Sally Warner of oscillating flow H L HL velocity form drag power average power floodslack work done on system #12;0 0 0 0 90 180 270 360 90 180 270 360 0 degrees Drag of oscillating flow H L HL velocity form drag power average

  6. Architecture, Data Model and Real-Time Performance Evaluation of the Streamonas Data Stream Management System

    E-Print Network [OSTI]

    Michael, Panayiotis Adamos

    2015-01-01

    a new model and architecture for data stream management”.Order Processing: A New Architecture for High- PerformanceDistributed Streamonas Architecture – and its Performance

  7. Direct-Steam Linear Fresnel Performance Model for NREL's System Advisor Model

    SciTech Connect (OSTI)

    Wagner, M. J.; Zhu, G.

    2012-09-01

    This paper presents the technical formulation and demonstrated model performance results of a new direct-steam-generation (DSG) model in NREL's System Advisor Model (SAM). The model predicts the annual electricity production of a wide range of system configurations within the DSG Linear Fresnel technology by modeling hourly performance of the plant in detail. The quasi-steady-state formulation allows users to investigate energy and mass flows, operating temperatures, and pressure drops for geometries and solar field configurations of interest. The model includes tools for heat loss calculation using either empirical polynomial heat loss curves as a function of steam temperature, ambient temperature, and wind velocity, or a detailed evacuated tube receiver heat loss model. Thermal losses are evaluated using a computationally efficient nodal approach, where the solar field and headers are discretized into multiple nodes where heat losses, thermal inertia, steam conditions (including pressure, temperature, enthalpy, etc.) are individually evaluated during each time step of the simulation. This paper discusses the mathematical formulation for the solar field model and describes how the solar field is integrated with the other subsystem models, including the power cycle and optional auxiliary fossil system. Model results are also presented to demonstrate plant behavior in the various operating modes.

  8. Computational Human Performance Modeling For Alarm System Design

    SciTech Connect (OSTI)

    Jacques Hugo

    2012-07-01

    The introduction of new technologies like adaptive automation systems and advanced alarms processing and presentation techniques in nuclear power plants is already having an impact on the safety and effectiveness of plant operations and also the role of the control room operator. This impact is expected to escalate dramatically as more and more nuclear power utilities embark on upgrade projects in order to extend the lifetime of their plants. One of the most visible impacts in control rooms will be the need to replace aging alarm systems. Because most of these alarm systems use obsolete technologies, the methods, techniques and tools that were used to design the previous generation of alarm system designs are no longer effective and need to be updated. The same applies to the need to analyze and redefine operators’ alarm handling tasks. In the past, methods for analyzing human tasks and workload have relied on crude, paper-based methods that often lacked traceability. New approaches are needed to allow analysts to model and represent the new concepts of alarm operation and human-system interaction. State-of-the-art task simulation tools are now available that offer a cost-effective and efficient method for examining the effect of operator performance in different conditions and operational scenarios. A discrete event simulation system was used by human factors researchers at the Idaho National Laboratory to develop a generic alarm handling model to examine the effect of operator performance with simulated modern alarm system. It allowed analysts to evaluate alarm generation patterns as well as critical task times and human workload predicted by the system.

  9. A CONCEPT TO ASSESS THE PERFORMANCE OF A PERMAFROST MODEL RUN FULLY COUPLED WITH A CLIMATE MODEL

    E-Print Network [OSTI]

    Moelders, Nicole

    A CONCEPT TO ASSESS THE PERFORMANCE OF A PERMAFROST MODEL RUN FULLY COUPLED WITH A CLIMATE MODEL APPROVED: Dean, College of Natural Science and Mathematics Dean of the Graduate School Date #12;A CONCEPT TO ASSESS THE PERFORMANCE OF A PERMAFROST MODEL RUN FULLY COUPLED WITH A CLIMATE MODEL A DISSERTATION

  10. PHOTOVOLTAIC ARRAY PERFORMANCE MODEL D. L. King, W. E. Boyson, J. A. Kratochvil

    E-Print Network [OSTI]

    PHOTOVOLTAIC ARRAY PERFORMANCE MODEL D. L. King, W. E. Boyson, J. A. Kratochvil Sandia National Photovoltaic Array Performance Model David L. King, William E. Boyson, Jay A. Kratochvil Photovoltaic System R This document summarizes the equations and applications associated with the photovoltaic array performance model

  11. PowerPerformance Modeling and Tradeoff Analysis for a High End Microprocessor

    E-Print Network [OSTI]

    Singh, Jaswinder Pal

    Power­Performance Modeling and Tradeoff Analysis for a High End Microprocessor David Brooks@us.ibm.com Abstract We describe a new power­performance modeling toolkit, developed to aid in the evaluation and defini­ tion of future power­efficient, PowerPC TM processors. The base performance models in use

  12. AGING PERFORMANCE OF MODEL 9975 PACKAGE FLUOROELASTOMER O-RINGS

    SciTech Connect (OSTI)

    Hoffman, E.; Daugherty, W.; Skidmore, E.; Dunn, K.; Fisher, D.

    2011-05-31

    The influence of temperature and radiation on Viton{reg_sign} GLT and GLT-S fluoroelastomer O-rings is an ongoing research focus at the Savannah River National Laboratory. The O-rings are credited for leaktight containment in the Model 9975 shipping package used for transportation of plutonium-bearing materials. At the Savannah River Site, the Model 9975 packages are being used for interim storage. Primary research efforts have focused on surveillance of O-rings from actual packages, leak testing of seals at bounding aging conditions and the effect of aging temperature on compression stress relaxation behavior, with the goal of service life prediction for long-term storage conditions. Recently, an additional effort to evaluate the effect of aging temperature on the oxidation of the materials has begun. Degradation in the mechanical properties of elastomers is directly related to the oxidation of the polymer. Sensitive measurements of the oxidation rate can be performed in a more timely manner than waiting for a measurable change in mechanical properties, especially at service temperatures. Measuring the oxidation rate therefore provides a means to validate the assumption that the degradation mechanisms(s) do not change from the elevated temperatures used for accelerated aging and the lower service temperatures. Monitoring the amount of oxygen uptake by the material over time at various temperatures can provide increased confidence in lifetime predictions. Preliminary oxygen consumption analysis of a Viton GLT-based fluoroelastomer compound (Parker V0835-75) using an Oxzilla II differential oxygen analyzer in the temperature range of 40-120 C was performed. Early data suggests oxygen consumption rates may level off within the first 100,000 hours (10-12 years) at 40 C and that sharp changes in the degradation mechanism (stress-relaxation) are not expected over the temperature range examined. This is consistent with the known long-term heat aging resistance of fluoroelastomers relative to hydrocarbon-based elastomers, and in absence of antioxidants that may be consumed over time. Additional experimental effort will be undertaken in the short term range within the first 100 hours of thermal aging to capture further details of the oxygen consumption rate.

  13. Tidal Dwarf Galaxies: Disc Formation at z=0

    E-Print Network [OSTI]

    Lelli, Federico; Brinks, Elias; McGaugh, Stacy S

    2015-01-01

    Collisional debris around interacting and post-interacting galaxies often display condensations of gas and young stars that can potentially form gravitationally bound objects: Tidal Dwarf Galaxies (TDGs). We summarise recent results on TDGs, which are originally published in Lelli et al. (2015, A&A). We study a sample of six TDGs around three different interacting systems, using high-resolution HI observations from the Very Large Array. We find that the HI emission associated to TDGs can be described by rotating disc models. These discs, however, would have undergone less than one orbit since the time of the TDG formation, raising the question of whether they are in dynamical equilibrium. Assuming that TDGs are in dynamical equilibrium, we find that the ratio of dynamical mass to baryonic mass is consistent with one, implying that TDGs are devoid of dark matter. This is in line with the results of numerical simulations where tidal forces effectively segregate dark matter in the halo from baryonic matter i...

  14. 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 RankADVANCEDInstallers/ContractorsPhotovoltaicsState ofSavings for Specific2HeldTidal Energy Resource

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

    SciTech Connect (OSTI)

    Craig W. Collar

    2012-11-16

    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. Using Machine Learning to Create Turbine Performance Models (Presentation)

    SciTech Connect (OSTI)

    Clifton, A.

    2013-04-01

    Wind turbine power output is known to be a strong function of wind speed, but is also affected by turbulence and shear. In this work, new aerostructural simulations of a generic 1.5 MW turbine are used to explore atmospheric influences on power output. Most significant is the hub height wind speed, followed by hub height turbulence intensity and then wind speed shear across the rotor disk. These simulation data are used to train regression trees that predict the turbine response for any combination of wind speed, turbulence intensity, and wind shear that might be expected at a turbine site. For a randomly selected atmospheric condition, the accuracy of the regression tree power predictions is three times higher than that of the traditional power curve methodology. The regression tree method can also be applied to turbine test data and used to predict turbine performance at a new site. No new data is required in comparison to the data that are usually collected for a wind resource assessment. Implementing the method requires turbine manufacturers to create a turbine regression tree model from test site data. Such an approach could significantly reduce bias in power predictions that arise because of different turbulence and shear at the new site, compared to the test site.

  17. Accelerating Energy Savings Performance Contracting Through Model Statewide Programs

    Broader source: Energy.gov [DOE]

    Provides suggestions on how to accelerateEnergy Savings Performance Contracting programs and information about the types of assistance provided under the 'Accelerated Energy Savings Performance Contracting' initiative. Author: Energy Services Coalition

  18. A 22 Degree Tidal Tail for Palomar 5

    E-Print Network [OSTI]

    C. J. Grillmair; O. Dionatos

    2006-03-02

    Using Data Release 4 of the Sloan Digital Sky Survey, we have applied an optimal contrast, matched filter technique to trace the trailing tidal tail of the globular cluster Palomar 5 to a distance of 18.5 degrees from the center of the cluster. This more than doubles the total known length of the tail to some 22 degrees on the sky. Based on a simple model of the Galaxy, we find that the stream's orientation on the sky is consistent at the 1.7 sigma level with existing proper motion measurements. We find that a spherical Galactic halo is adequate to model the stream over its currently known length, and we are able to place new constraints on the current space motion of the cluster.

  19. Modeling the Performance of Engineered Systems for Closure and...

    Office of Environmental Management (EM)

    Management Environmental Management Agenda * Overview of DOE Performance Assessment Practices * Focused Discussions - Role of PA Process in Risk Communication and...

  20. Transformations of galaxies. III. Encounter dynamics and tidal response as functions of galaxy structure

    E-Print Network [OSTI]

    Barnes, Joshua E

    2015-01-01

    Tidal interactions between disc galaxies depend on galaxy structure, but the details of this relationship are incompletely understood. I have constructed a three-parameter grid of bulge/disc/halo models broadly consistent with $\\Lambda$CDM, and simulated an extensive series of encounters using these models. Halo mass and extent strongly influence the dynamics of orbit evolution. In close encounters, the transfer of angular momentum mediated by the dynamical response of massive, extended haloes can reverse the direction of orbital motion of the central galaxies after their first passage. Tidal response is strongly correlated with the ratio $v_\\mathrm{e} / v_\\mathrm{c}$ of escape to circular velocity within the participating discs. Moreover, the same ratio also correlates with the rate at which tidal tails are reaccreted by their galaxies of origin; consequently, merger remnants with `twin tails', such as NGC 7252, may prove hard to reproduce unless $(v_\\mathrm{e} / v_\\mathrm{c})^2 \\lesssim 5.5$. The tidal morp...

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

    E-Print Network [OSTI]

    Hayasaki, Kimitake; Loeb, Abraham

    2015-01-01

    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. Performance assessment model of a single waste package (Conference...

    Office of Scientific and Technical Information (OSTI)

    12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; 11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; WASTE FORMS; PERFORMANCE; P CODES; RADIOACTIVE...

  3. First Commercial, Grid-Connected, Hydrokinetic Tidal Energy Project...

    Office of Science (SC) Website

    First Commercial, Grid-Connected, Hydrokinetic Tidal Energy Project in North America Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR) SBIR...

  4. Performance and Portability of an Air Quality Model Donald Dabdub

    E-Print Network [OSTI]

    Manohar, Rajit

    and planning for the control of air pollution episodes. The California Institute of Technology (CIT) photochemical model is one such air quality model. It is used to predict the pollution dynamics in the South Coast Air Basin of California. It has also been modified to model pollution in South Korea, Mexico

  5. Case Studies Comparing System Advisor Model (SAM) Results to Real Performance Data: Preprint

    SciTech Connect (OSTI)

    Blair, N.; Dobos, A.; Sather, N.

    2012-06-01

    NREL has completed a series of detailed case studies comparing the simulations of the System Advisor Model (SAM) and measured performance data or published performance expectations. These case studies compare PV measured performance data with simulated performance data using appropriate weather data. The measured data sets were primarily taken from NREL onsite PV systems and weather monitoring stations.

  6. Tidal heating of Earth-like exoplanets around M stars: Thermal, magnetic, and orbital evolutions

    E-Print Network [OSTI]

    Driscoll, Peter

    2015-01-01

    The internal thermal and magnetic evolution of rocky exoplanets is critical to their habitability. We focus on the thermal-orbital evolution of Earth-mass planets around low mass M stars whose radiative habitable zone overlaps with the "tidal zone". We develop a thermal-orbital evolution model calibrated to Earth that couples tidal dissipation, with a temperature-dependent Maxwell rheology, to orbital circularization and migration. We illustrate thermal-orbital steady states where surface heat flow is balanced by tidal dissipation and cooling can be stalled for billions of years until circularization occurs. Orbital energy dissipated as tidal heat in the interior drives both inward migration and circularization, with a circularization time that is inversely proportional to the dissipation rate. We identify a peak in the internal dissipation rate as the mantle passes through a visco-elastic state at mantle temperatures near 1800 K. Planets orbiting a 0.1 solar-mass star within $0.07$ AU circularize before 10 G...

  7. Tidal constituent database. West Coast of the United States and Eastern North pacific ocean. Technical note

    SciTech Connect (OSTI)

    NONE

    1995-01-01

    This technical note describes a database of tidal elevation boundary condition information generated in support of the `Long-Term Fate of Dredged Material Disposed in Open Water` research of the Dredging Research Program (DRP), being conducted at the U.S. Army Engineer Waterways Experiment Station. The database, described in detail by Hench and others (1994), allows the user to manually generate time series of tidal elevations or to use a program to access the full database to generate time series of both tidal elevations and currents for any location along the West Coast of the United States and Eastern North Pacific Ocean, extending from Seal Cape on Unimak Island, Alaska, in the North to Punta Parada, Peru, in the South. The land boundary includes the Pacific shorelines of Alaska, Canada, mainland United States, Mexico, Guatemala, El Salvador, Nicaragua, Costa Rica, Panama, Columbia, and Northern Peru. Although the capability to generate these time series was developed to provide input to the Long-Term Fate and Stability Model (LTFATE), the generated time series can be used for any application requiring tidal forcing data.

  8. TIDAL INTERACTION AS THE ORIGIN OF EARLY-TYPE DWARF GALAXIES IN GROUP ENVIRONMENTS

    SciTech Connect (OSTI)

    Paudel, Sanjaya; Ree, Chang H.

    2014-11-20

    We present a sample of dwarf galaxies that suffer ongoing disruption by the tidal forces of nearby massive galaxies. By analyzing structural and stellar population properties using the archival imaging and spectroscopic data from the Sloan Digital Sky Survey (SDSS), we find that they are likely a ''smoking gun'' example of the formation through tidal stirring of early-type dwarf galaxies (dEs) in the galaxy group environment. The inner cores of these galaxies are fairly intact and the observed light profiles are well fit by the Sérsic functions while the tidally stretched stellar halos are prominent in the outer parts. They are all located within a sky-projected distance of 50 kpc from the centers of the host galaxies and no dwarf galaxies have relative line-of-sight velocities larger than 205 km s{sup –1} to their hosts. We derive the Composite Stellar Population properties of these galaxies by fitting the SDSS optical spectra to a multiple-burst composite stellar population model. We find that these galaxies accumulate a significant fraction of stellar mass within the last 1 Gyr and contain a majority stellar population with an intermediate age of 2 to 4 Gyr. Based on this evidence, we argue that tidal stirring, particularly through the galaxy-galaxy interaction, might have an important role in the formation and evolution of dEs in the group environment where the influence of other gas stripping mechanism might be limited.

  9. Investigation of Tidal Exchange and the Formation of Tidal Vortices at Aransas Pass, Texas, USA 

    E-Print Network [OSTI]

    Whilden, Kerri Ann

    2015-08-11

    Laboratory and field measurements are presented as part of a study of tidal exchange through Aransas Pass, Texas. At the mouth of Aransas Pass, the input of circulation by the ebb tide forces the formation of a starting-jet dipole vortex...

  10. The importance of tidal creek ecosystems Keywords: Estuary; Tidal creek; Pollution

    E-Print Network [OSTI]

    Mallin, Michael

    . They are most abundant along the Atlantic Seaboard from New Jersey to Florida, and along the Gulf Coast). Tidal creeks are especially abundant in low-energy systems such as protected areas behind barrier. As an example, the four southernmost coastal counties in North Carolina (Onslow, Pender, New Hanover

  11. A Model-Driven Approach to Service Performance Prediction and Analysis

    E-Print Network [OSTI]

    de Lara, Juan

    the analysis or simulation of the original model. An important issue in systems validation, and in particular, to identify performance bottlenecks and load limits. If this activity is done in the modelling phase BPEL [A07] models, which are annotated by a profiling engineer with performance estimations

  12. Comments on: High Fidelity Evaluation of Tidal Turbine Performance for

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C

  13. Sandia Energy - High Fidelity Evaluation of Tidal Turbine Performance for

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II)Geothermal Energy & Drilling TechnologyHeavy Duty HomeHeavyIndustry

  14. 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 Center Home Page| Open Energy Information Serbia-EnhancingEt Al., 2013)Open Energy Information ThreeTianDi GrowthTibagiTidalTest

  15. Wind and tidal response of a semi-enclosed bay, Bahía Concepción, Baja California

    E-Print Network [OSTI]

    Ponte, Aurélien L. S.

    2009-01-01

    J. H. , 1973: Tidal patterns and energy balance in the GulfTable 4.1). Because the tidal energy is similar between boththe mouth. Some energy is captured by the tidal analysis at

  16. Ocean Tidal Dissipation and its Role in Solar System Satellite Evolution

    E-Print Network [OSTI]

    Chen, Erinna

    2013-01-01

    Significant dissipation of tidal energy in the deep ocean2001. Estimates of M 2 tidal energy dissipation from TOPEX/e.g. the ocean kinetic energy and tidal dissipation, using a

  17. Snacktime for Hungry Black Holes: Theoretical Studies of the Tidal Disruption of Stars

    E-Print Network [OSTI]

    Strubbe, Linda Elisabeth

    2011-01-01

    tidal disruption rate as a function of pericenter distance at various energies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Tidal disruption rate as a function of pericenter distance at various energies2.5: Spectral energy distributions for tidal flares around a

  18. Binary asteroid systems: Tidal end states and estimates of material properties

    E-Print Network [OSTI]

    Taylor, PA; Margot, JL

    2011-01-01

    tidal evolution and then discuss stability limits and energyon tidal evolution. Angular momentum and energy content Theenergy can be dissipated as heat as a result of internal friction due to tidal ?

  19. An integrated performance model for high temperature gas cooled reactor coated particle fuel

    E-Print Network [OSTI]

    Wang, Jing, 1976-

    2004-01-01

    The performance of coated fuel particles is essential for the development and deployment of High Temperature Gas Reactor (HTGR) systems for future power generation. Fuel performance modeling is indispensable for understanding ...

  20. The influence of team mental models and team planning on team performance 

    E-Print Network [OSTI]

    Leiva Neuenschwander, Pedro Ignacio

    2009-06-02

    Since Cannon-Bowers, Salas, and Converse (1993) introduced the concept of mental models (MMs) to team performance research, theory and research have supported the idea that common cognitions among team members facilitate team performance. One...

  1. Generation IV benchmarking of TRISO fuel performance models under accident conditions. Modeling input data

    SciTech Connect (OSTI)

    Blaise Collin

    2014-09-01

    This document presents the benchmark plan for the calculation of particle fuel performance on safety testing experiments that are representative of operational accidental transients. The benchmark is dedicated to the modeling of fission product release under accident conditions by fuel performance codes from around the world, and the subsequent comparison to post-irradiation experiment (PIE) data from the modeled heating tests. The accident condition benchmark is divided into three parts: the modeling of a simplified benchmark problem to assess potential numerical calculation issues at low fission product release; the modeling of the AGR-1 and HFR-EU1bis safety testing experiments; and, the comparison of the AGR-1 and HFR-EU1bis modeling results with PIE data. The simplified benchmark case, thereafter named NCC (Numerical Calculation Case), is derived from ''Case 5'' of the International Atomic Energy Agency (IAEA) Coordinated Research Program (CRP) on coated particle fuel technology [IAEA 2012]. It is included so participants can evaluate their codes at low fission product release. ''Case 5'' of the IAEA CRP-6 showed large code-to-code discrepancies in the release of fission products, which were attributed to ''effects of the numerical calculation method rather than the physical model''[IAEA 2012]. The NCC is therefore intended to check if these numerical effects subsist. The first two steps imply the involvement of the benchmark participants with a modeling effort following the guidelines and recommendations provided by this document. The third step involves the collection of the modeling results by Idaho National Laboratory (INL) and the comparison of these results with the available PIE data. The objective of this document is to provide all necessary input data to model the benchmark cases, and to give some methodology guidelines and recommendations in order to make all results suitable for comparison with each other. The participants should read this document thoroughly to make sure all the data needed for their calculations is provided in the document. Missing data will be added to a revision of the document if necessary.

  2. Multidimensional approaches to performance evaluation of competing forecasting models 

    E-Print Network [OSTI]

    Xu, Bing

    2009-01-01

    The purpose of my research is to contribute to the field of forecasting from a methodological perspective as well as to the field of crude oil as an application area to test the performance of my methodological contributions ...

  3. A Microcomputer Model of Crossflow Cooling Tower Performance 

    E-Print Network [OSTI]

    Reichelt, G. E; Jones, J. W.

    1984-01-01

    to evaluate its response; moreover, a subprogram can evaluate pressure drop and motor/fan characteristics. Determination of the energy required to operate the tower enables its performance to be compared against energy-saving operations such as variable speed...

  4. Improving Face Recognition Performance Using a Hierarchical Bayesian Model

    E-Print Network [OSTI]

    Shikaripur Nadig, Ashwini

    2010-04-27

    which can result in an improved recognition performance over already existing baseline approaches. We use Kernelized Fisher Discriminant Analysis (KFLD) as our baseline as it is superior to PCA in a way that it produces well separated classes even under...

  5. Accelerating Energy Savings Performance Contracting Through Model Statewide Programs

    Broader source: Energy.gov [DOE]

    Provides information on Energy Savings Performance Contracing (ESPC), including links to best practices and tools as well as the Accelerated ESCP initiative and types of assistance available. Author: Energy Services Coalition

  6. Development of a High-Performance Office Building Simulation Model for a Hot and Humid Climate 

    E-Print Network [OSTI]

    Cho, S.; Haberl, J.

    2009-01-01

    applicable to office buildings in hot and humid climates and to develop a high-performance (maximum energy-efficient) building model that only uses technologies readily available in the contemporary market. The high-performance model showed 48% total... HIGH-PERFORMANCE OFFICE BUILDING SIMULATION MODEL FOR A HOT AND HUMID CLIMATE Soolyeon Cho1 and Jeff S. Haberl2 1The Catholic University of America, Washington, D.C., USA 2Texas A&M University, College Station, TX, USA ABSTRACT...

  7. Methodology for Modeling Building Energy Performance across the Commercial Sector

    SciTech Connect (OSTI)

    Griffith, B.; Long, N.; Torcellini, P.; Judkoff, R.; Crawley, D.; Ryan, J.

    2008-03-01

    This report uses EnergyPlus simulations of each building in the 2003 Commercial Buildings Energy Consumption Survey (CBECS) to document and demonstrate bottom-up methods of modeling the entire U.S. commercial buildings sector (EIA 2006). The ability to use a whole-building simulation tool to model the entire sector is of interest because the energy models enable us to answer subsequent 'what-if' questions that involve technologies and practices related to energy. This report documents how the whole-building models were generated from the building characteristics in 2003 CBECS and compares the simulation results to the survey data for energy use.

  8. Summary Results for Brine Migration Modeling Performed by LANL...

    Energy Savers [EERE]

    modeling related to coupled processes involving brine and vapor migration in geologic salt, focusing on recent developments and studies conducted at Sandia, Los Alamos, and...

  9. Summary Results for Brine Migration Modeling Performed by LANL...

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

    tightly coupled solutions (Kim, 2010; Prevost, 2014). Tight coupling does not require freezing state variables or iterating between models, but it requires more computer memory and...

  10. Fuel Cell Power Model for CHHP System Economics and Performance Analysis (Presentation)

    SciTech Connect (OSTI)

    Steward, D.

    2009-11-16

    Presentation about Fuel Cell Power (FCPower) Model used to analyze the economics and performance of combined heat, hydrogen, and power (CHHP) systems.

  11. Lyman Alpha Absorption and Tidal Debris

    E-Print Network [OSTI]

    Simon L. Morris

    1994-09-29

    The origin and evolution of structure in the Universe is one of the major questions occupying astronomers today. An understanding of the Lyalpha absorbers seen in QSO spectra is an important part of this program since such absorbers can be traced back to very high redshifts. Their mere existence places constraints on the physical state of the intergalactic medium. The discovery of Lyalpha absorbers at low redshift allows us to estimate for the first time what fraction of low redshift Lyalpha absorbers are (i) randomly distributed, (ii) distributed like galaxies but not physically associated with luminous objects, (iii) actually part of the halos of luminous galaxies, or (iv) tidal tails within galaxy groups. Results from the sightline to the QSO 3C273 suggest that the majority of the absorbers are not associated with galaxies, but that there is a significant subset that are. The absorbers associated with galaxies may be produced in enormous gaseous disks surrounding normal spiral galaxies, or may be tidal material bound up in small groups of galaxies

  12. Personal Computer-Based Model for Cool Storage Performance Simulation 

    E-Print Network [OSTI]

    Kasprowicz, L. M.; Jones, J. W.; Hitzfelder, J.

    1990-01-01

    A personal computer based hourly simulation model was developed based on the CBS/ICE routines in the DOE-2.1 mainframe building simulation software. The menu driven new model employs more efficient data and information handling than the previous...

  13. Virginia Wetlands Report Tools of the Tidal Shoreline

    E-Print Network [OSTI]

    Virginia Wetlands Report Tools of the Tidal Shoreline Management Trade Friday, October 13, 2006) technology with digital aerial photographs and the power of the Internet. They are accessible from desktop Comprehensive Coastal Inventory has produced several GIS tools for the tidal shoreline management trade

  14. Enhancing tidal harmonic analysis: Robust (hybrid L1 ) solutions

    E-Print Network [OSTI]

    Hickey, Barbara

    Enhancing tidal harmonic analysis: Robust (hybrid L1 =L2 ) solutions Keith E. Leffler Ã, David A 24 February 2008 Accepted 28 April 2008 Keywords: Tides Tidal analysis Harmonic analysis Robust is calculated from the power spectrum of the residual, a calculation that filters broad spectrum noise

  15. Tilted Baroclinic Tidal Vortices MIGUEL CANALS AND GENO PAWLAK

    E-Print Network [OSTI]

    MacCready, Parker

    Tilted Baroclinic Tidal Vortices MIGUEL CANALS AND GENO PAWLAK Department of Ocean and Resources coherence. It is suggested that this may lead to a conversion of potential energy into kinetic energy. 1 mixing of coastal waters (Mul- ler and Garrett 2003). Of particular importance is the tidally driven case

  16. Tidal Conversion at a Submarine Ridge FRANOIS PTRLIS

    E-Print Network [OSTI]

    Young, William R.

    ). Satellite altimetry has shown deep-sea tidal energy losses concentrated at submarine ridges and island arcsTidal Conversion at a Submarine Ridge FRANÇOIS PÉTRÉLIS Laboratoire de Physique Statistique, Ecole received 30 July 2003, in final form 20 January 2004) ABSTRACT The radiative flux of internal wave energy

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

    SciTech Connect (OSTI)

    Worthington, Monty

    2014-02-05

    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.

  18. Modeling the Impact of Product Portfolio on the Economic and Environmental Performance of Recycling Systems

    E-Print Network [OSTI]

    Dahmus, Jeffrey B.

    hrough the development of a general model of electronics recycling systems, the effect of product portfolio choices on economic and environmental system performance is explored. The general model encompasses the three main ...

  19. Performance of Assisted History Matching Techniques When Utilizing Multiple Initial Geologic Models 

    E-Print Network [OSTI]

    Aggarwal, Akshay

    2011-11-15

    History matching is a process wherein changes are made to an initial geologic model of a reservoir, so that the predicted reservoir performance matches with the known production history. Changes are made to the model parameters which include rock...

  20. Improving the Performance of a Dutch CSR by Modeling Pronunciation Variation 

    E-Print Network [OSTI]

    Wester, Mirjam; Kessens, Judith M; Strik, Helmer

    This paper describes how the performance of a continuous speech recognizer for Dutch has been improved by modeling pronunciation variation. We used three methods in order to model pronunciation variation. First, within-word ...

  1. An improved structural mechanics model for the FRAPCON nuclear fuel performance code

    E-Print Network [OSTI]

    Mieloszyk, Alexander James

    2012-01-01

    In order to provide improved predictions of Pellet Cladding Mechanical Interaction (PCMI) for the FRAPCON nuclear fuel performance code, a new model, the FRAPCON Radial-Axial Soft Pellet (FRASP) model, was developed. This ...

  2. Tidal deformation of a slowly rotating material body. External metric

    E-Print Network [OSTI]

    Philippe Landry; Eric Poisson

    2015-07-31

    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 new quantities, which we designate as rotational-tidal Love numbers. All these Love numbers are gauge invariant in the usual sense of perturbation theory, and all vanish when the body is a black hole.

  3. Confusion around the tidal force and the centrifugal force

    E-Print Network [OSTI]

    Matsuda, Takuya; Boffin, Henri M J

    2015-01-01

    We discuss the tidal force, whose notion is sometimes misunderstood in the public domain literature. We discuss the tidal force exerted by a secondary point mass on an extended primary body such as the Earth. The tidal force arises because the gravitational force exerted on the extended body by the secondary mass is not uniform across the primary. In the derivation of the tidal force, the non-uniformity of the gravity is essential, and inertial forces such as the centrifugal force are not needed. Nevertheless, it is often asserted that the tidal force can be explained by the centrifugal force. If we literally take into account the centrifugal force, it would mislead us. We therefore also discuss the proper treatment of the centrifugal force.

  4. A fluiddynamic performance model of a helicon , M. Merino

    E-Print Network [OSTI]

    Carlos III de Madrid, Universidad

    magnetic nozzle are derived, for a known amount of absorbed power from rf waves. 2D plasma structure of helicon thruster performances in terms of power, thrust and efficiency. I. Introduction Research to gain a share in space propulsion. Different prototypes have been tested [1­4]. Opportunities

  5. WUFI COMPUTER MODELING WORKSHOP FOR WALL DESIGN AND PERFORMANCE

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    from rain, solar radiation and other crucial weather events on an hourly basis. Both vapor and liquid which can easily be selected from a map. The temporal behavior of the computed quantities (temperatures tell me ­ performance predicting · Mold growth predictions ­ new post-processing modules · Development

  6. HIDDENARTICULATOR MARKOV MODELS: PERFORMANCE IMPROVEMENTS AND ROBUSTNESS TO NOISE

    E-Print Network [OSTI]

    Bilmes, Jeff

    ], we extended the articulatory­feature model introduced by Erler [7] by using diphone units and a new] discuss the analysis­by­synthesis approach, which attempts to estimate the parameters of the Coker [3

  7. Abstract--Eventually, prediction of transformer thermal performance for dynamic loading will be made using models

    E-Print Network [OSTI]

    1 Abstract--Eventually, prediction of transformer thermal performance for dynamic loading will be made using models distilled from measure data, rather than models derived from transformer heat for measuring the acceptability of transformer thermal models. For a model to be acceptable, it must have

  8. Tidal Disruption Flares as the Source of Ultra-high Energy Cosmic Rays

    E-Print Network [OSTI]

    Glennys R. Farrar

    2012-10-03

    The optical spectral energy distributions of two tidal disruption flares identified by van Velzen et al. (2011) in archival SDSS data, are found to be well-fit by a thin-accretion-disk model. Furthermore, the inferred Supermassive Black Hole mass values agree well with the SMBH masses estimated from the host galaxy properties. Integrating the model SEDs to include shorter wavelength contributions provides an estimate of the bolometric luminosities of the accretion disks. The resultant bolometric luminosities are well in excess of the minimum required for accelerating UHECR protons. In combination with the recent observational estimate of the TDF rate (van Velzen and Farrar, these Proceedings), the results presented here strengthen the case that transient jets formed in tidal disruption events may be responsible for accelerating all or most UHECRs.

  9. Tidal Disruption Flares as the Source of Ultra-high Energy Cosmic Rays

    E-Print Network [OSTI]

    Farrar, Glennys R

    2012-01-01

    The optical spectral energy distributions of two tidal disruption flares identified by van Velzen et al. (2011) in archival SDSS data, are found to be well-fit by a thin-accretion-disk model. Furthermore, the inferred Supermassive Black Hole mass values agree well with the SMBH masses estimated from the host galaxy properties. Integrating the model SEDs to include shorter wavelength contributions provides an estimate of the bolometric luminosities of the accretion disks. The resultant bolometric luminosities are well in excess of the minimum required for accelerating UHECR protons. In combination with the recent observational estimate of the TDF rate (van Velzen and Farrar, these Proceedings), the results presented here strengthen the case that transient jets formed in tidal disruption events may be responsible for accelerating all or most UHECRs.

  10. Performance and Degradation Modeling of Batteries | 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 RankADVANCED MANUFACTURINGEnergy Bills andOrder 422.1, CONDUCT PDepartment ofPerformance Measurement of

  11. Performance of High-Performance Glazing in IECC Compliant Building Simulation Model 

    E-Print Network [OSTI]

    Mukhopadhyay, J.; Haberl, J. S.

    2006-01-01

    . The TMY2 weather file (NREL, 1995) for Houston is used to carry out simulations. ? Selection of high-performance glazing Six glazing options were selected for this set of simulations to represent a range of current and potential window types... in hot and humid climates. Masters thesis, Department of Architecture, Texas A&M University. NREL. 1995. Users Manual for TMY2's. NRELlSP? 463-7668, and TMY2s, Typical Meteorological Years Derived from the 1961-1990. National Solar Radiation Data...

  12. Analysis of Molten Carbonate Fuel Cell Performance Using a Three-Phase Homogeneous Model

    E-Print Network [OSTI]

    Popov, Branko N.

    Analysis of Molten Carbonate Fuel Cell Performance Using a Three-Phase Homogeneous Model N-phase homogeneous model was developed to simulate the performance of the molten carbonate fuel cell MCFC cathode received June 18, 2002. Available electronically November 15, 2002. Molten carbonate fuel cells MCFCs

  13. A data-based approach for multivariate model predictive control performance monitoring$

    E-Print Network [OSTI]

    Chen, Sheng

    A data-based approach for multivariate model predictive control performance monitoring$ Xuemin Tian of Petroleum (Hua Dong), Donying, Shandong 257061, China b School of Electronics and Computer Science by J. Zhang Available online 20 October 2010 Keywords: Model predictive control Performance monitoring

  14. A Methodology for Developing Simple and Robust Power Models Using Performance Monitoring Events

    E-Print Network [OSTI]

    Fedorova, Alexandra

    A Methodology for Developing Simple and Robust Power Models Using Performance Monitoring Events Kishore Kumar Pusukuri UC Riverside kishore@cs.ucr.edu David Vengerov Sun Microsystems Laboratories david.vengerov@sun a methodology for develop- ing simple and robust power models using performance monitoring events for AMD Quad

  15. Performance Modeling of Transmission Schedulers for Sensor Networks Capable of Energy Harvesting

    E-Print Network [OSTI]

    Sikdar, Biplab

    Performance Modeling of Transmission Schedulers for Sensor Networks Capable of Energy Harvesting transmit is formulated as a Markov Decision Process (MDP) and the performance of the transmission policy such as vibration and motion, light, and heat. However, to improve the performance of energy harvesting WSNs

  16. Modeling the Logistics Performance in Developing Countries: An exploratory study of Moroccan context

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Modeling the Logistics Performance in Developing Countries: An exploratory study of Moroccan to raise their levels of logistics performance. This article is a research progress; it presents, Technological Practices, Supply Chain performance, Morocco. 1. INTRODUCTION: Logistic in Morocco is still

  17. The variation of the tidal quality factor of convective envelopes of rotating low-mass stars along their evolution

    E-Print Network [OSTI]

    Mathis, S

    2015-01-01

    More than 1500 exoplanets have been discovered around a large diversity of host stars (from M- to A-type stars). Tidal dissipation in their convective envelope is a key actor that shapes the orbital architecture of short-period systems and that still remains unknown. Using a simplified two-layer assumption and grids of stellar models, we compute analytically an equivalent modified tidal quality factor, which is proportional to the inverse of the frequency-averaged dissipation due to the viscous friction applied by turbulent convection on tidal waves. It leads the conversion of their kinetic energy into heat and tidal evolution of orbits and spin. During their Pre-Main-Sequence, all low-mass stars have a decrease of the equivalent modified tidal quality factor for a fixed angular velocity of their convective envelope. Next, it evolves on the Main Sequence to an asymptotic value that is minimum for $0.6M_{\\odot}$ K-type stars and that increases by several orders of magnitude with increasing stellar mass. Finall...

  18. Stochastic modeling and performance monitoring of wind farm power production

    E-Print Network [OSTI]

    Milan, Patrick; Peinke, Joachim

    2015-01-01

    We present a new stochastic approach to describe and remodel the conversion process of a wind farm at a sampling frequency of 1Hz. When conditioning on various wind direction sectors, the dynamics of the conversion process appear as a fluctuating trajectory around an average IEC-like power curve, see section II. Our approach is to consider the wind farm as a dynamical system that can be described as a stochastic drift/diffusion model, where a drift coefficient describes the attraction towards the power curve and a diffusion coefficient quantifies additional turbulent fluctuations. These stochastic coefficients are inserted into a Langevin equation that, once properly adapted to our particular system, models a synthetic signal of power output for any given wind speed/direction signals, see section III. When combined with a pre-model for turbulent wind fluctuations, the stochastic approach models the power output of the wind farm at a sampling frequency of 1Hz using only ten-minute average values of wind speed ...

  19. A structured performance modelling formalism Stephen Gilmore1

    E-Print Network [OSTI]

    Gilmore, Stephen

    ]). The combination of stochastic Petri nets with queueing networks in particular has been a source of inspiration's Dynamic Queueing Networks [12]. An extension of (non-stochastic) Petri nets which provides modelling language for labelled stochas- tic Petri nets. Viewed in another way, the net is used to provide

  20. Incorporating Control Performance Tuning into Economic Model Predictive Control

    E-Print Network [OSTI]

    Olanrewaju, Olumuyiwa I.; Maciejowski, Jan M.

    2015-01-01

    [1] A. Singh, J. Forbes, P. Vermeer, and S. Woo, “Model-based real-time optimization of automotive gasoline blending operations,” Journal of Process Control, vol. 10, no. 1, pp. 43 – 58, 2000. [2] A. Toumi and S. Engell, “Optimization-based control...

  1. 18 Modeling high-performance HBTs D.L. Pulfrey

    E-Print Network [OSTI]

    Pulfrey, David L.

    which may be useful in the engineering design of high-frequency and high-speed devices-off frequency, fT which, in its turn, is related to the unity gain, power cut-off frequency, fmax. These two circuit suitable for the simulation of HBTs in switching applications. 18.2 Microscopic modeling of HBTs

  2. FRAPCON-3: Modifications to fuel rod material properties and performance models for high-burnup application

    SciTech Connect (OSTI)

    Lanning, D.D.; Beyer, C.E.; Painter, C.L.

    1997-12-01

    This volume describes the fuel rod material and performance models that were updated for the FRAPCON-3 steady-state fuel rod performance code. The property and performance models were changed to account for behavior at extended burnup levels up to 65 Gwd/MTU. The property and performance models updated were the fission gas release, fuel thermal conductivity, fuel swelling, fuel relocation, radial power distribution, solid-solid contact gap conductance, cladding corrosion and hydriding, cladding mechanical properties, and cladding axial growth. Each updated property and model was compared to well characterized data up to high burnup levels. The installation of these properties and models in the FRAPCON-3 code along with input instructions are provided in Volume 2 of this report and Volume 3 provides a code assessment based on comparison to integral performance data. The updated FRAPCON-3 code is intended to replace the earlier codes FRAPCON-2 and GAPCON-THERMAL-2. 94 refs., 61 figs., 9 tabs.

  3. CASL-U-2015-0162-000 Performance Model

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room News PublicationsAudits &Bradbury Science Museum6 Shares1-000 SMR Fuel2-000 Performance

  4. Measurement of the rate of stellar tidal disruption flares

    SciTech Connect (OSTI)

    Van Velzen, Sjoert

    2014-09-01

    We report an observational estimate of the rate of stellar tidal disruption flares (TDFs) in inactive galaxies based on a successful search for these events among transients in galaxies using archival Sloan Digital Sky Survey (SDSS) multi-epoch imaging data (Stripe 82). This search yielded 186 nuclear flares in galaxies, 2 of which are excellent TDF candidates. Because of the systematic nature of the search, the very large number of galaxies, the long time of observation, and the fact that non-TDFs were excluded without resorting to assumptions about TDF characteristics, this study provides an unparalleled opportunity to measure the TDF rate. To compute the rate of optical stellar tidal disruption events, we simulate our entire pipeline to obtain the efficiency of detection. The rate depends on the light curves of TDFs, which are presently still poorly constrained. Using only the observed part of the SDSS light curves gives a model-independent upper limit to the optical TDF rate, N-dot <2×10{sup ?4} yr{sup ?1} galaxy{sup ?1} (90% CL), under the assumption that the SDSS TDFs are representative examples. We develop three empirical models of the light curves based on the two SDSS light curves and two more recent and better-sampled Pan-STARRS TDF light curves, leading to our best estimate of the rate: N-dot {sub TDF}=(1.5--2.0){sub ?1.3}{sup +2.7}×10{sup ?5} yr{sup ?1} galaxy{sup ?1}. We explore the modeling uncertainties by considering two theoretically motivated light curve models, as well as two different relationships between black hole mass and galaxy luminosity, and two different treatments of the cutoff in the visibility of TDFs at large M {sub BH}. From this we conclude that these sources of uncertainty are not significantly larger than the statistical ones. Our results are applicable for galaxies hosting black holes with mass in the range of a few 10{sup 6}-10{sup 8} M {sub ?}, and translates to a volumetric TDF rate of (4-8) × 10{sup –8±0.4} yr{sup –1} Mpc{sup –3}, with the statistical uncertainty in the exponent.

  5. Models Used to Assess the Performance of Photovoltaic Systems | Department

    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 RankADVANCED MANUFACTURING OFFICESpecialAPPENDIX F Wetlandsof Energy ModelSEI Layer | Department ofof

  6. WATER TRAPPING ON TIDALLY LOCKED TERRESTRIAL PLANETS REQUIRES SPECIAL CONDITIONS

    SciTech Connect (OSTI)

    Yang, Jun; Abbot, Dorian S.; Liu, Yonggang; Hu, Yongyun

    2014-12-01

    Surface liquid water is essential for standard planetary habitability. Calculations of atmospheric circulation on tidally locked planets around M stars suggest that this peculiar orbital configuration lends itself to the trapping of large amounts of water in kilometers-thick ice on the night side, potentially removing all liquid water from the day side where photosynthesis is possible. We study this problem using a global climate model including coupled atmosphere, ocean, land, and sea ice components as well as a continental ice sheet model driven by the climate model output. For a waterworld, we find that surface winds transport sea ice toward the day side and the ocean carries heat toward the night side. As a result, nightside sea ice remains O(10 m) thick and nightside water trapping is insignificant. If a planet has large continents on its night side, they can grow ice sheets O(1000 m) thick if the geothermal heat flux is similar to Earth's or smaller. Planets with a water complement similar to Earth's would therefore experience a large decrease in sea level when plate tectonics drives their continents onto the night side, but would not experience complete dayside dessiccation. Only planets with a geothermal heat flux lower than Earth's, much of their surface covered by continents, and a surface water reservoir O(10%) of Earth's would be susceptible to complete water trapping.

  7. Comparison of Demand Response Performance with an EnergyPlus Model in a Low Energy Campus Building

    E-Print Network [OSTI]

    Dudley, Junqiao Han

    2010-01-01

    Performance with an EnergyPlus Model in a Low Energy CampusPerformance with an EnergyPlus Model in a Low Energy Campusevents. In this paper, an EnergyPlus model of the building

  8. Sensitivity of Concentrating Solar Power Trough Performance, Cost and Financing with Solar Advisor Model

    SciTech Connect (OSTI)

    Blair, N.; Mehos, M.; Christensen, C.

    2008-03-01

    A comprehensive solar technology systems analysis model, the Solar Advisor Model (SAM) was developed to support the federal R&D community and the solar industry. This model, developed by staff at NREL and Sandia National Laboratory, is able to model the costs, finances, and performance of concentrating solar power and photovoltaics (PV). Currently, parabolic troughs and concentrating PV are the two concentrating technologies modeled within the SAM environment.

  9. Modeling Photovoltaic and Concentrating Solar Power Trough Performance, Cost, and Financing with the Solar Advisor Model: Preprint

    SciTech Connect (OSTI)

    Blair, N.; Mehos, M.; Christensen, C.; Cameron, C.

    2008-05-01

    A comprehensive solar technology systems analysis model, the Solar Advisor Model (SAM), has been developed to support the federal R&D community and the solar industry by staff at the National Renewable Energy Laboratory (NREL) and Sandia National Laboratory. This model is able to model the finances, incentives, and performance of flat-plate photovoltaic (PV), concentrating PV, and concentrating solar power (specifically, parabolic troughs). The primary function of the model is to allow users to investigate the impact of variations in performance, cost, and financial parameters to better understand their impact on key figures of merit. Figures of merit related to the cost and performance of these systems include, but aren't limited to, system output, system efficiencies, levelized cost of energy, return on investment, and system capital and O&M costs. There are several models within SAM to model the performance of photovoltaic modules and inverters. This paper presents an overview of each PV and inverter model, introduces a new generic model, and briefly discusses the concentrating solar power (CSP) parabolic trough model. A comparison of results using the different PV and inverter models is also presented.

  10. Hybrid Model for Building Performance Diagnosis and Optimal Control 

    E-Print Network [OSTI]

    Wang, S.; Xu, X.

    2003-01-01

    S. (1983). Raising the open U value by passive means. Proc. 8th Nat. Passive Solar Conf. Glorieta, NM, pp.839-842. Bahai H. and Esat I.I. (1994). A hybrid model for analysis of complex stress distribution in threaded connectors. Computers... Research Centre of Finland. Kalogirou SA, Neocleous CC and Schizas CN. (1997). Heating load estimation using artificial neural networks. In: Proc. CLIMA 2000 Conf., Brussels (Belgium). Klein S.A., Beckman W.A. et al. (1994). TRNSYS-A Transient System...

  11. Sandia Energy - PV Performance Modeling Collaborative's New and

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II)Geothermal Energy &WaterNew CREWOnline Abstracts andPV Modeling

  12. Measurement of Tidal Form Drag Using Seafloor Pressure Sensors SALLY J. WARNER AND PARKER MACCREADY

    E-Print Network [OSTI]

    MacCready, Parker

    tides. The tidally averaged power removed from the tidal currents by form drag was 0.2 W m22 , whichMeasurement of Tidal Form Drag Using Seafloor Pressure Sensors SALLY J. WARNER AND PARKER MACCREADY the tidal form drag on a sloping ridge in 200 m of water that forms a 1-km headland at the surface in Puget

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

    E-Print Network [OSTI]

    were generated locally by a propagating beam of internal tidal energy which had originatedUnder consideration for publication in J. Fluid Mech. 1 Reflecting tidal wave beams and local generation mecha- nism: tidal flow over steep topography forces a propagating beam of internal tidal wave

  14. Results and Comparison from the SAM Linear Fresnel Technology Performance Model: Preprint

    SciTech Connect (OSTI)

    Wagner, M. J.

    2012-04-01

    This paper presents the new Linear Fresnel technology performance model in NREL's System Advisor Model. The model predicts the financial and technical performance of direct-steam-generation Linear Fresnel power plants, and can be used to analyze a range of system configurations. This paper presents a brief discussion of the model formulation and motivation, and provides extensive discussion of the model performance and financial results. The Linear Fresnel technology is also compared to other concentrating solar power technologies in both qualitative and quantitative measures. The Linear Fresnel model - developed in conjunction with the Electric Power Research Institute - provides users with the ability to model a variety of solar field layouts, fossil backup configurations, thermal receiver designs, and steam generation conditions. This flexibility aims to encompass current market solutions for the DSG Linear Fresnel technology, which is seeing increasing exposure in fossil plant augmentation and stand-alone power generation applications.

  15. GEOPHYSICAL RESEARCH LETTERS, VOL. 28, NO. 5, PAGES 811-814, MARCH 1, 2001 Parameterizing Tidal Dissipation over Rough

    E-Print Network [OSTI]

    Jayne, Steven

    of barotropic tidal energy. The first line of evidence comes from observations of mix- ing in the abyssal Brazil ocean, the energy flux carried by internal waves generated over rough topog- raphy dominates the energy issues. The first is whether including a parameterization for internal wave energy-flux in a model

  16. Stress and Productivity Performance in the Workforce Modelled with Binary Decision Automata

    E-Print Network [OSTI]

    Ashlock, Dan

    Stress and Productivity Performance in the Workforce Modelled with Binary Decision Automata Matthew of stress in the workplace. Stress and stress-related health problems are a serious matter but, prior to this series of studies, quantitative modeling of stress has been substantially neglected. This model builds

  17. The X-ray through Optical Fluxes and Line Strengths of Tidal Disruption Events

    E-Print Network [OSTI]

    Roth, Nathaniel; Guillochon, James; Ramirez-Ruiz, Enrico

    2015-01-01

    Observations of luminous flares resulting from the possible tidal disruption of stars by supermassive black holes have raised a number of puzzles. Outstanding questions include the origin of the optical and ultraviolet (UV) flux, the weakness of hydrogen lines in the spectrum, and the occasional simultaneous observation of x-rays. Here we study the emission from tidal disruption events (TDEs) produced as radiation from black hole accretion propagates through an extended, optically thick envelope formed from stellar debris. We analytically describe key physics controlling spectrum formation, and present detailed radiative transfer calculations that model the spectral energy distribution (SED) and optical line strengths of TDEs near peak brightness. The steady-state transfer is coupled to a non local thermodynamic equilibrium treatment of the excitation and ionization states of hydrogen, helium and oxygen (as a representative metal). Our calculations show how an extended envelope can reprocess a fraction of sof...

  18. Hydrodynamic analysis of a vertical axis tidal current turbine 

    E-Print Network [OSTI]

    Gretton, Gareth I.

    2009-01-01

    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 ...

  19. Numerical and Experimental Investigation of Tidal Current Energy Extraction 

    E-Print Network [OSTI]

    Sun, Xiaojing

    2008-01-01

    Numerical and experimental investigations of tidal current energy extraction have been conducted in this study. A laboratory-scale water flume was simulated using commercial computational fluid dynamics (CFD) code FLUENT. ...

  20. Geomorphic structure of tidal hydrodynamics in salt marsh creeks

    E-Print Network [OSTI]

    Fagherazzi, Sergio

    .1029/2007WR006289. 1. Introduction [2] Salt marshes are important transitional areas between terrestrial providing preferen- tial pathways for marsh flooding and drainage during the tidal cycle. Because

  1. Supercomputer and cluster performance modeling and analysis efforts:2004-2006.

    SciTech Connect (OSTI)

    Sturtevant, Judith E.; Ganti, Anand; Meyer, Harold Edward; Stevenson, Joel O.; Benner, Robert E., Jr.; Goudy, Susan Phelps; Doerfler, Douglas W.; Domino, Stefan Paul; Taylor, Mark A.; Malins, Robert Joseph; Scott, Ryan T.; Barnette, Daniel Wayne; Rajan, Mahesh; Ang, James Alfred; Black, Amalia Rebecca; Laub, Thomas William; Vaughan, Courtenay Thomas; Franke, Brian Claude

    2007-02-01

    This report describes efforts by the Performance Modeling and Analysis Team to investigate performance characteristics of Sandia's engineering and scientific applications on the ASC capability and advanced architecture supercomputers, and Sandia's capacity Linux clusters. Efforts to model various aspects of these computers are also discussed. The goals of these efforts are to quantify and compare Sandia's supercomputer and cluster performance characteristics; to reveal strengths and weaknesses in such systems; and to predict performance characteristics of, and provide guidelines for, future acquisitions and follow-on systems. Described herein are the results obtained from running benchmarks and applications to extract performance characteristics and comparisons, as well as modeling efforts, obtained during the time period 2004-2006. The format of the report, with hypertext links to numerous additional documents, purposefully minimizes the document size needed to disseminate the extensive results from our research.

  2. Improvement of capabilities of the Distributed Electrochemistry Modeling Tool for investigating SOFC long term performance

    SciTech Connect (OSTI)

    Gonzalez Galdamez, Rinaldo A.; Recknagle, Kurtis P.

    2012-04-30

    This report provides an overview of the work performed for Solid Oxide Fuel Cell (SOFC) modeling during the 2012 Winter/Spring Science Undergraduate Laboratory Internship at Pacific Northwest National Laboratory (PNNL). A brief introduction on the concept, operation basics and applications of fuel cells is given for the general audience. Further details are given regarding the modifications and improvements of the Distributed Electrochemistry (DEC) Modeling tool developed by PNNL engineers to model SOFC long term performance. Within this analysis, a literature review on anode degradation mechanisms is explained and future plans of implementing these into the DEC modeling tool are also proposed.

  3. Architecture and Performance Models for Scalable IP Lookup Engines on FPGA*

    E-Print Network [OSTI]

    Hwang, Kai

    requirement of the IP lookup engine. In particular, a simple but realistic model of DDR3 memory is used designs achieve 5.6x ­ 70x the energy efficiency of TCAM, and have performance independent of the prefix

  4. Thermal mass performance in residential construction : an energy analysis using a cube model

    E-Print Network [OSTI]

    Ledwith, Alison C. (Alison Catherine)

    2012-01-01

    Given the pervasiveness of energy efficiency concerns in the built environment, this research aims to answer key questions regarding the performance of thermal mass construction. The work presents the Cube Model, a simplified ...

  5. Design optimization and analysis of coated particle fuel using advanced fuel performance modeling techniques

    E-Print Network [OSTI]

    Soontrapa, Chaiyod

    2005-01-01

    Modifying material properties provides another approach to optimize coated particle fuel used in pebble bed reactors. In this study, the MIT fuel performance model (TIMCOAT) was applied after benchmarking against the ...

  6. Towards a Computational Model of Musical Accompaniment: Disambiguation of Musical Analyses by Reference to Performance Data 

    E-Print Network [OSTI]

    Curry, Benjamin David

    A goal of Artificial Intelligence is to develop computational models of what would be considered intelligent behaviour in a human. One such task is that of musical performance. This research specifically focuses on aspects ...

  7. Modeling the Impact of Operator Trust on Performance in Multiple Robot Control,

    E-Print Network [OSTI]

    Gao, F.

    We developed a system dynamics model to simulate the impact of operator trust on performance in multiple robot control. Analysis of a simulated urban search and rescue experiment showed that operators decided to manually ...

  8. Improved Building Energy Performance Modelling through Comparison of Measured Data with Simulated Results 

    E-Print Network [OSTI]

    Bambrook, S.; Jacob, D.

    2008-01-01

    the building and comparing simulated results to the measured data. The simulated building energy performance results achieved in the first stage of computer modelling show a reasonable correlation with measured data, however, further work is required to create...

  9. Microsoft Word - NRAP-TRS-III-002-2012_Modeling the Performance...

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

    Modeling the Performance of Large- Scale CO 2 Storage Systems: A Comparison of Different Sensitivity Analysis Methods 24 October 2012 Office of Fossil Energy NRAP-TRS-III-002-2012...

  10. Systems, methods and computer-readable media for modeling cell performance fade of rechargeable electrochemical devices

    DOE Patents [OSTI]

    Gering, Kevin L

    2013-08-27

    A system includes an electrochemical cell, monitoring hardware, and a computing system. The monitoring hardware periodically samples performance characteristics of the electrochemical cell. The computing system determines cell information from the performance characteristics of the electrochemical cell. The computing system also develops a mechanistic level model of the electrochemical cell to determine performance fade characteristics of the electrochemical cell and analyzing the mechanistic level model to estimate performance fade characteristics over aging of a similar electrochemical cell. The mechanistic level model uses first constant-current pulses applied to the electrochemical cell at a first aging period and at three or more current values bracketing a first exchange current density. The mechanistic level model also is based on second constant-current pulses applied to the electrochemical cell at a second aging period and at three or more current values bracketing the second exchange current density.

  11. Sandia Energy - Tidal Energy Resource Assessment in the East River Tidal

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II)GeothermalFuel Magnetization andStochasticunique wind(CREW)Tidal

  12. Simulation of heavy oil reservoir performance using a non-Newtonian flow model 

    E-Print Network [OSTI]

    Narahara, Gene Masao

    1983-01-01

    SIMULATION OF HEAVY OIL RESERVOIR PERFORMANCE USING A NON-NEWTONIAN FLOW MODEL A Thesis by GENE MASAO NARAHARA Submitted to the Graduate College of Texas AILM University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE December 1983 Major Subject: Petroleum Engineering SIMULATION OF HEAVY OIL RESERVOIR PERFORMANCE USING A NON-NEWTONIAN FLOW MODEL A Thesis by GENE MASAO NARAHARA Approved as to style and content by: lng . U an of Committee) R. . Morse...

  13. A Bright Year for Tidal Disruptions?

    E-Print Network [OSTI]

    Metzger, Brian D

    2015-01-01

    When a star is tidally disrupted by a supermassive black hole (BH), roughly half of its mass falls back to the BH at super-Eddington rates. Being tenuously gravitationally bound and unable to cool radiatively, only a small fraction f_in few 1e4 K, converting the emission to optical/near-UV wavelengths where photons more readily escape due to the lower opacity. This can explain the unexpectedly low and temporally constant effective temperatures of optically-discovered TDE flares. For BHs with relatively high masses M_BH > 1e7 M_sun the ejecta can become ionized at an earlier stage, or for a wider range of viewing angles, producing a TDE flare which is instead dominated by thermal X-ray emission. We predict total radiated energies consistent with those of observed TDE flares, and ejecta velocities that agree with the measured emission line widths. The peak optical luminosity for M_BH wind, possibly contributing to the unexpected dearth of o...

  14. Modeling and evaluating the performance of Brillouin distributed optical fiber sensors

    E-Print Network [OSTI]

    Dalang, Robert C.

    Modeling and evaluating the performance of Brillouin distributed optical fiber sensors Marcelo A analysis of the key factors impacting on the performance of Brillouin distributed optical fiber sensors-of-merit offers to the research community and to potential users the possibility to evaluate with an objective

  15. Modeling Multithreaded Architectures in PAMELA for Realtime High Performance Applications \\Lambda

    E-Print Network [OSTI]

    Modeling Multi­threaded Architectures in PAMELA for Real­time High Performance Applications \\Lambda­threading is fast evolving as an alternative architecture for high performance applica­ tions. In such architectures Faculty of Electrical Engineering Indian Institute of Science Delft University of Technology Bangalore

  16. A HUMAN PERFORMANCE MODEL OF COMMERCIAL JETLINER TAXIING Michael D. Byrne, Jeffrey C. Zemla

    E-Print Network [OSTI]

    Byrne, Mike

    performance between large-scale engineering-oriented simulations and human-in-the-loop experiments. In order are limited in several ways. One common method is to employ human-in-the-loop (HITL) experiments. In orderA HUMAN PERFORMANCE MODEL OF COMMERCIAL JETLINER TAXIING Michael D. Byrne, Jeffrey C. Zemla Rice

  17. MODELING THE EFFECT OF FLOW FIELD DESIGN ON PEM FUEL CELL PERFORMANCE

    E-Print Network [OSTI]

    Van Zee, John W.

    and transportation applications. One aspect that is crucial to optimizing the performance of PEM fuel cellsMODELING THE EFFECT OF FLOW FIELD DESIGN ON PEM FUEL CELL PERFORMANCE Jeffrey Glandt, Sirivatch Shimpalee, Woo-kum Lee, and John W. Van Zee Fuel Cell Research Laboratory Department of Chemical Engineering

  18. An accurate performance model of shared buffer ATM switches under hot spot traffic

    E-Print Network [OSTI]

    Atiquzzaman, Mohammed

    An accurate performance model of shared buffer ATM switches under hot spot traffic M. Saleha , M Abstract Asynchronous transfer mode (ATM) switches based on shared buffering are known to have better performance and buffer utilization than input or output queued switches. Shared buffer switches do not suffer

  19. Modeling the performance of high burnup thoria and urania PWR fuel

    E-Print Network [OSTI]

    Long, Yun, 1972-

    2002-01-01

    Fuel performance models have been developed to assess the performance of ThO?-UO? fuels that can be operated to a high burnup up to 80-100MWd/kgHM in current and future Light Water Reactors (LWRs). Among the various issues ...

  20. Tidal torques dynamical friction and the structure of clusters of galaxies

    E-Print Network [OSTI]

    A. Del Popolo; M. Gambera

    2001-05-22

    We study the joint effect of tidal torques and dynamical friction on the collapse of density peaks solving numerically the equations of motion of a shell of barionic matter falling into the central regions of a cluster of galaxies. We calculate the evolution of the expansion parameter, a(t), of the perturbation using a coefficient of dynamical friction eta_{cl} obtained from a clustered system and taking into account the gravitational interaction of the quadrupole moment of the system with the tidal field of the matter of the neighboring proto-galaxies. We show that within high-density environments, such as rich clusters of galaxies, tidal torques and dynamical friction slow down the collapse of low-nu peaks producing an observable variation of the parameter of expansion of the shell. As a consequence a bias of dynamical nature arises because high-density peaks preferentially collapse to form halos within which visible objects eventually will condense. For a standard Cold Dark Matter model this dynamical bias can account for a substantial part of the total bias required by observations on cluster scales.

  1. Jet and disk luminosities in tidal disruption events

    E-Print Network [OSTI]

    Piran, Tsvi; Tchekhovskoy, Alexander

    2015-01-01

    Tidal disruption events (TDE) in which a star is devoured by a massive black hole at a galac- tic center pose a challenge to our understanding of accretion processes. Within a month the accretion rate reaches super-Eddington levels. It then drops gradually over a time scale of a year to sub-Eddington regimes. The initially geometrically thick disk becomes a thin one and eventually an ADAF at very low accretion rates. As such, TDEs explore the whole range of accretion rates and configurations. A challenging question is what the corresponding light curves of these events are. We explore numerically the disk luminosity and the conditions within the inner region of the disk using a fully general relativistic slim disk model. Those conditions determine the magnitude of the magnetic field that engulfs the black hole and this, in turn, determines the Blandford-Znajek jet power. We estimate this power in two different ways and show that they are self-consistent. We find, as expected earlier from analytic argu- ments ...

  2. Adaptation and Validation of an Agent Model of Functional State and Performance for Individuals

    E-Print Network [OSTI]

    Treur, Jan

    functional state model to the individual and validation of the resulting model. First, human experiments have mostly qualitative theories from Psychology, but was not validated yet using human experiments been performed by taking a number of steps. First of all, an experiment with 31 human subjects has been

  3. Gyrokinetic Modeling of Macro-Instabilities in High Performance Tokamak Plasmas

    E-Print Network [OSTI]

    Jaun, André

    on two separate fronts. The #12;rst accounted for the resonant e#11;ects in the energetic particleGyrokinetic Modeling of Macro-Instabilities in High Performance Tokamak Plasmas A Jauny, A Fasoliz, Switzerland E-mail: jaun@fusion.kth.se Abstract. The modeling of Alfv#19;enic instabilities is discussed from

  4. Performance of Ecient Minimization Algorithms as Applied to Models of Peptides and Proteins

    E-Print Network [OSTI]

    Performance of EÆcient Minimization Algorithms as Applied to Models of Peptides and Proteins C minimization algorithms as applied to models of pep- tides and proteins; they are, the limited memory quasi - Pro 2 -Phe 3 -Val 4 -Leu 5 -Pro 6 -Val 7 ), 62 atoms], and the protein bovine pancreatic trypsin

  5. 2 CONCEPT OF MODEL BASED TAMPERING FOR 3 IMPROVING PROCESS PERFORMANCE

    E-Print Network [OSTI]

    Bukkapatnam, Satish T.S.

    1 2 CONCEPT OF MODEL BASED TAMPERING FOR 3 IMPROVING PROCESS PERFORMANCE: 4 AN ILLUSTRATIVE 14 This paper presents the concept of a methodology called Model Based 15 Tampering (MBT based tampering (MBT), which is conceptualized in this paper, will 38 become necessary in order to meet

  6. Filament-Level Modeling of Aramid-Based High-Performance Structural Materials

    E-Print Network [OSTI]

    Grujicic, Mica

    Filament-Level Modeling of Aramid-Based High-Performance Structural Materials M. Grujicic, W/ filaments. These fibers can be considered as prototypes for advanced high strength/high-stiffness fibers to be most affected by the presence of sheet stacking faults. Keywords filament-level modeling, Kevlar

  7. A Distributed Electrochemistry Modeling Tool for Simulating SOFC Performance and Degradation

    SciTech Connect (OSTI)

    Recknagle, Kurtis P.; Ryan, Emily M.; Khaleel, Mohammad A.

    2011-10-13

    This report presents a distributed electrochemistry (DEC) model capable of investigating the electrochemistry and local conditions with the SOFC MEA based on the local microstructure and multi-physics. The DEC model can calculate the global current-voltage (I-V) performance of the cell as determined by the spatially varying local conditions through the thickness of the electrodes and electrolyte. The simulation tool is able to investigate the electrochemical performance based on characteristics of the electrode microstructure, such as particle size, pore size, electrolyte and electrode phase volume fractions, and triple-phase-boundary length. It can also investigate performance as affected by fuel and oxidant gas flow distributions and other environmental/experimental conditions such as temperature and fuel gas composition. The long-term objective for the DEC modeling tool is to investigate factors that cause electrode degradation and the decay of SOFC performance which decrease longevity.

  8. Systems, methods and computer-readable media to model kinetic performance of rechargeable electrochemical devices

    DOE Patents [OSTI]

    Gering, Kevin L.

    2013-01-01

    A system includes an electrochemical cell, monitoring hardware, and a computing system. The monitoring hardware samples performance characteristics of the electrochemical cell. The computing system determines cell information from the performance characteristics. The computing system also analyzes the cell information of the electrochemical cell with a Butler-Volmer (BV) expression modified to determine exchange current density of the electrochemical cell by including kinetic performance information related to pulse-time dependence, electrode surface availability, or a combination thereof. A set of sigmoid-based expressions may be included with the modified-BV expression to determine kinetic performance as a function of pulse time. The determined exchange current density may be used with the modified-BV expression, with or without the sigmoid expressions, to analyze other characteristics of the electrochemical cell. Model parameters can be defined in terms of cell aging, making the overall kinetics model amenable to predictive estimates of cell kinetic performance along the aging timeline.

  9. User's Manual for Data for Validating Models for PV Module Performance

    SciTech Connect (OSTI)

    Marion, W.; Anderberg, A.; Deline, C.; Glick, S.; Muller, M.; Perrin, G.; Rodriguez, J.; Rummel, S.; Terwilliger, K.; Silverman, T. J.

    2014-04-01

    This user's manual describes performance data measured for flat-plate photovoltaic (PV) modules installed in Cocoa, Florida, Eugene, Oregon, and Golden, Colorado. The data include PV module current-voltage curves and associated meteorological data for approximately one-year periods. These publicly available data are intended to facilitate the validation of existing models for predicting the performance of PV modules, and for the development of new and improved models. For comparing different modeling approaches, using these public data will provide transparency and more meaningful comparisons of the relative benefits.

  10. A Comparison of HCCI Engine Performance Data and Kinetic Modeling Results over a Wide Rangeof Gasoline Range Surrogate Fuel Blends

    Broader source: Energy.gov [DOE]

    Kinetic models of fuels are needed to allow the simulation of engine performance for research, design, or verification purposes.

  11. Modeling and performance evaluation of flexible manufacturing systems using Petri nets

    SciTech Connect (OSTI)

    Callotta, M.P.; Cimenez, C.; Tazza, M.

    1996-12-31

    A timed Petri net approach is used to model resource allocation-utilization-release patterns for performance evaluation. First, simple resource utilization sequences are derived from a directed graph representing the process plan of parts. Second, the place-transitions sequences are connected introducing places whose marking models the resources needed to perform the manufacturing operation indicated in the process plan. Time is introduced as a permanence time of tokens at the place-transition sequence, modeling the utilization time of resources. The corresponding model leads to a simultaneous resource possession problem. Finally, flow equations for the description of the quantitative behavior of the resulting timed Petri net are presented. A major conclusion of the paper is that performance evaluation can be adequately abstracted and analytically solved, in a simple way, even in presence of complicating factors like resource sharing and routing flexibility in process plans.

  12. Methodology for Constructing Reduced-Order Power Block Performance Models for CSP Applications: Preprint

    SciTech Connect (OSTI)

    Wagner, M.

    2010-10-01

    The inherent variability of the solar resource presents a unique challenge for CSP systems. Incident solar irradiation can fluctuate widely over a short time scale, but plant performance must be assessed for long time periods. As a result, annual simulations with hourly (or sub-hourly) timesteps are the norm in CSP analysis. A highly detailed power cycle model provides accuracy but tends to suffer from prohibitively long run-times; alternatively, simplified empirical models can run quickly but don?t always provide enough information, accuracy, or flexibility for the modeler. The ideal model for feasibility-level analysis incorporates both the detail and accuracy of a first-principle model with the low computational load of a regression model. The work presented in this paper proposes a methodology for organizing and extracting information from the performance output of a detailed model, then using it to develop a flexible reduced-order regression model in a systematic and structured way. A similar but less generalized approach for characterizing power cycle performance and a reduced-order modeling methodology for CFD analysis of heat transfer from electronic devices have been presented. This paper builds on these publications and the non-dimensional approach originally described.

  13. Better Buildings Neighborhood Program Business Models Guide: Home Performance Contractor Business Model Conclusion

    Broader source: Energy.gov [DOE]

    The summary details important observations on home performance contractors and those observations’ impact on potential expansion into the residential energy efficiency market. Understanding these impacts can help home performance contractors, program administrators, and other actors create and/or sustain a business that promotes energy efficiency.

  14. Advanced modeling and simulation to design and manufacture high performance and reliable advanced microelectronics and microsystems.

    SciTech Connect (OSTI)

    Nettleship, Ian (University of Pittsburgh, Pittsburgh, PA); Hinklin, Thomas; Holcomb, David Joseph; Tandon, Rajan; Arguello, Jose Guadalupe, Jr. (,; .); Dempsey, James Franklin; Ewsuk, Kevin Gregory; Neilsen, Michael K.; Lanagan, Michael (Pennsylvania State University, University Park, PA)

    2007-07-01

    An interdisciplinary team of scientists and engineers having broad expertise in materials processing and properties, materials characterization, and computational mechanics was assembled to develop science-based modeling/simulation technology to design and reproducibly manufacture high performance and reliable, complex microelectronics and microsystems. The team's efforts focused on defining and developing a science-based infrastructure to enable predictive compaction, sintering, stress, and thermomechanical modeling in ''real systems'', including: (1) developing techniques to and determining materials properties and constitutive behavior required for modeling; (2) developing new, improved/updated models and modeling capabilities, (3) ensuring that models are representative of the physical phenomena being simulated; and (4) assessing existing modeling capabilities to identify advances necessary to facilitate the practical application of Sandia's predictive modeling technology.

  15. General relativistic tidal work for Papapetrou, Weinberg and Goldberg pseudotensors

    E-Print Network [OSTI]

    Lau Loi So

    2015-05-18

    In 1998 Thorne claimed that all pseudotensors give the same tidal work as the Newtonian theory. In 1999, Purdue used the Landau-Lifshitz pseudotensor to calculate the tidal heating and the result matched with the Newtonian gravity. Soon after in 2001, Favata employed the same method to examine the Einstein, Bergmann-Thomson and M{\\o}ller pseudotensors, all of them give the same result as Purdue did. Inspired by the work of Purdue and Favata, for the completeness, here we manipulate the tidal work for Papapetrou, Weinberg and Goldberg pseudotensors. We obtained the same tidal work as Purdue achieved. In addition, we emphasize that a suitable gravitational energy-momentum pseudotensor requires fulfill the inside matter condition and all of the classical pseudotensors pass this test except M$\\o$ller. Moreover, we constructed a general pseudotesnor which is modified by 13 linear artificial higher order terms combination with Einstein pseudotensor. We find that the result agrees with Thorne's prediction, i.e., relativistic tidal work is pseudotensor independent.

  16. Variability in tidal disruption events: gravitationally unstable streams

    E-Print Network [OSTI]

    Coughlin, Eric R

    2015-01-01

    We present simulations of the tidal disruption of a solar mass star by a $10^6M_{\\odot}$ black hole. These, for the first time, cover the full time evolution of the tidal disruption event, starting well before the initial encounter and continuing until more than 90% of the bound material has returned to the vicinity of the hole. Our results are compared to the analytical prediction for the rate at which tidally-stripped gas falls back. We find that, for our chosen parameters, the overall scaling of the fallback rate, $\\dot{M}_{\\rm{fb}}$, closely follows the canonical $t^{-5/3}$ power-law. However, our simulations also show that the self-gravity of the tidal stream, which dominates the tidal gravity of the hole at large distances, causes some of the debris to recollapse into bound fragments before returning to the hole. This causes $\\dot{M}_{\\rm{fb}}$ to vary significantly around the $t^{-5/3}$ average. We discuss the implications of our findings in the context of the event Swift J1644+57.

  17. The variation of tidal dissipation in the convective envelope of low-mass stars along their evolution

    E-Print Network [OSTI]

    Mathis, S

    2015-01-01

    Since 1995, more than 1500 exoplanets have been discovered around a large diversity of host stars (from M- to A-type stars). Tidal dissipation in stellar convective envelopes is a key actor that shapes the orbital architecture of short-period systems. Our objective is to understand and evaluate how tidal dissipation in the convective envelope of low-mass stars (from M to F types) depends on their mass, evolutionary stage and rotation. Using a simplified two-layer assumption, we compute analytically the frequency-averaged tidal dissipation in their convective envelope. This dissipation is due to the conversion into heat of the kinetic energy of tidal non wave-like/equilibrium flow and inertial waves because of the viscous friction applied by turbulent convection. Using grids of stellar models allows us to study the variation of the dissipation as a function of stellar mass and age on the Pre-Main-Sequence and on the Main-Sequence for stars with masses spanning from $0.4$ to $1.4M_{\\odot}$. As shown by observat...

  18. Analysis report for WIPP colloid model constraints and performance assessment parameters

    SciTech Connect (OSTI)

    Mariner, Paul E.; Sassani, David Carl

    2014-03-01

    An analysis of the Waste Isolation Pilot Plant (WIPP) colloid model constraints and parameter values was performed. The focus of this work was primarily on intrinsic colloids, mineral fragment colloids, and humic substance colloids, with a lesser focus on microbial colloids. Comments by the US Environmental Protection Agency (EPA) concerning intrinsic Th(IV) colloids and Mg-Cl-OH mineral fragment colloids were addressed in detail, assumptions and data used to constrain colloid model calculations were evaluated, and inconsistencies between data and model parameter values were identified. This work resulted in a list of specific conclusions regarding model integrity, model conservatism, and opportunities for improvement related to each of the four colloid types included in the WIPP performance assessment.

  19. Understanding the Effect of Baseline Modeling Implementation Choices on Analysis of Demand Response Performance

    SciTech Connect (OSTI)

    University of California, Berkeley; Addy, Nathan; Kiliccote, Sila; Mathieu, Johanna; Callaway, Duncan S.

    2012-06-13

    Accurate evaluation of the performance of buildings participating in Demand Response (DR) programs is critical to the adoption and improvement of these programs. Typically, we calculate load sheds during DR events by comparing observed electric demand against counterfactual predictions made using statistical baseline models. Many baseline models exist and these models can produce different shed calculations. Moreover, modelers implementing the same baseline model can make different modeling implementation choices, which may affect shed estimates. In this work, using real data, we analyze the effect of different modeling implementation choices on shed predictions. We focused on five issues: weather data source, resolution of data, methods for determining when buildings are occupied, methods for aligning building data with temperature data, and methods for power outage filtering. Results indicate sensitivity to the weather data source and data filtration methods as well as an immediate potential for automation of methods to choose building occupied modes.

  20. REVIEW OF MECHANISTIC UNDERSTANDING AND MODELING AND UNCERTAINTY ANALYSIS METHODS FOR PREDICTING CEMENTITIOUS BARRIER PERFORMANCE

    SciTech Connect (OSTI)

    Langton, C.; Kosson, D.

    2009-11-30

    Cementitious barriers for nuclear applications are one of the primary controls for preventing or limiting radionuclide release into the environment. At the present time, performance and risk assessments do not fully incorporate the effectiveness of engineered barriers because the processes that influence performance are coupled and complicated. Better understanding the behavior of cementitious barriers is necessary to evaluate and improve the design of materials and structures used for radioactive waste containment, life extension of current nuclear facilities, and design of future nuclear facilities, including those needed for nuclear fuel storage and processing, nuclear power production and waste management. The focus of the Cementitious Barriers Partnership (CBP) literature review is to document the current level of knowledge with respect to: (1) mechanisms and processes that directly influence the performance of cementitious materials (2) methodologies for modeling the performance of these mechanisms and processes and (3) approaches to addressing and quantifying uncertainties associated with performance predictions. This will serve as an important reference document for the professional community responsible for the design and performance assessment of cementitious materials in nuclear applications. This review also provides a multi-disciplinary foundation for identification, research, development and demonstration of improvements in conceptual understanding, measurements and performance modeling that would be lead to significant reductions in the uncertainties and improved confidence in the estimating the long-term performance of cementitious materials in nuclear applications. This report identifies: (1) technology gaps that may be filled by the CBP project and also (2) information and computational methods that are in currently being applied in related fields but have not yet been incorporated into performance assessments of cementitious barriers. The various chapters contain both a description of the mechanism or and a discussion of the current approaches to modeling the phenomena.

  1. Empirical Performance Model-Driven Data Layout Optimization and Library Call Selection for Tensor Contraction Expressions

    SciTech Connect (OSTI)

    Lu, Qingda; Gao, Xiaoyang; Krishnamoorthy, Sriram; Baumgartner, Gerald; Ramanujam, J.; Sadayappan, Ponnuswamy

    2012-03-01

    Empirical optimizers like ATLAS have been very effective in optimizing computational kernels in libraries. The best choice of parameters such as tile size and degree of loop unrolling is determined by executing different versions of the computation. In contrast, optimizing compilers use a model-driven approach to program transformation. While the model-driven approach of optimizing compilers is generally orders of magnitude faster than ATLAS-like library generators, its effectiveness can be limited by the accuracy of the performance models used. In this paper, we describe an approach where a class of computations is modeled in terms of constituent operations that are empirically measured, thereby allowing modeling of the overall execution time. The performance model with empirically determined cost components is used to perform data layout optimization together with the selection of library calls and layout transformations in the context of the Tensor Contraction Engine, a compiler for a high-level domain-specific language for expressing computational models in quantum chemistry. The effectiveness of the approach is demonstrated through experimental measurements on representative computations from quantum chemistry.

  2. Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC).

    SciTech Connect (OSTI)

    Schultz, Peter Andrew

    2011-12-01

    The objective of the U.S. Department of Energy Office of Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC) is to provide an integrated suite of computational modeling and simulation (M&S) capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive-waste storage facility or disposal repository. Achieving the objective of modeling the performance of a disposal scenario requires describing processes involved in waste form degradation and radionuclide release at the subcontinuum scale, beginning with mechanistic descriptions of chemical reactions and chemical kinetics at the atomic scale, and upscaling into effective, validated constitutive models for input to high-fidelity continuum scale codes for coupled multiphysics simulations of release and transport. Verification and validation (V&V) is required throughout the system to establish evidence-based metrics for the level of confidence in M&S codes and capabilities, including at the subcontiunuum scale and the constitutive models they inform or generate. This Report outlines the nature of the V&V challenge at the subcontinuum scale, an approach to incorporate V&V concepts into subcontinuum scale modeling and simulation (M&S), and a plan to incrementally incorporate effective V&V into subcontinuum scale M&S destined for use in the NEAMS Waste IPSC work flow to meet requirements of quantitative confidence in the constitutive models informed by subcontinuum scale phenomena.

  3. FRAMEWORK AND APPLICATION FOR MODELING CONTROL ROOM CREW PERFORMANCE AT NUCLEAR POWER PLANTS

    SciTech Connect (OSTI)

    Ronald L Boring; David I Gertman; Tuan Q Tran; Brian F Gore

    2008-09-01

    This paper summarizes an emerging project regarding the utilization of high-fidelity MIDAS simulations for visualizing and modeling control room crew performance at nuclear power plants. The key envisioned uses for MIDAS-based control room simulations are: (i) the estimation of human error associated with advanced control room equipment and configurations, (ii) the investigative determination of contributory cognitive factors for risk significant scenarios involving control room operating crews, and (iii) the certification of reduced staffing levels in advanced control rooms. It is proposed that MIDAS serves as a key component for the effective modeling of cognition, elements of situation awareness, and risk associated with human performance in next generation control rooms.

  4. Development of long-term performance models for radioactive waste forms

    SciTech Connect (OSTI)

    Bacon, Diana H.; Pierce, Eric M.

    2011-03-22

    The long-term performance of solid radioactive waste is measured by the release rate of radionuclides into the environment, which depends on corrosion or weathering rates of the solid waste form. The reactions involved depend on the characteristics of the solid matrix containing the radioactive waste, the radionuclides of interest, and their interaction with surrounding geologic materials. This chapter describes thermo-hydro-mechanical and reactive transport models related to the long-term performance of solid radioactive waste forms, including metal, ceramic, glass, steam reformer and cement. Future trends involving Monte-Carlo simulations and coupled/multi-scale process modeling are also discussed.

  5. Modeling the Integrated Performance of Dispersion and Monolithic U-Mo Based Fuels

    SciTech Connect (OSTI)

    Daniel M. Wachs; Douglas E. Burkes; Steven L. Hayes; Karen Moore; Greg Miller; Gerard Hofman; Yeon Soo Kim

    2006-10-01

    The evaluation and prediction of integrated fuel performance is a critical component of the Reduced Enrichment for Research and Test Reactors (RERTR) program. The PLATE code is the primary tool being developed and used to perform these functions. The code is being modified to incorporate the most recent fuel/matrix interaction correlations as they become available for both aluminum and aluminum/silicon matrices. The code is also being adapted to treat cylindrical and square pin geometries to enhance the validation database by including the results gathered from various international partners. Additional modeling work has been initiated to evaluate the thermal and mechanical performance requirements unique to monolithic fuels during irradiation.

  6. Laboratory Analysis of Vortex Dynamics For Shallow Tidal Inlets 

    E-Print Network [OSTI]

    Whilden, Kerri Ann

    2010-10-12

    OF VORTEX DYNAMICS FOR SHALLOW TIDAL INLETS A Thesis by KERRI ANN WHILDEN Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements for the degree of MASTER OF SCIENCE August 2009 Major Subject: Ocean... Engineering LABORATORY ANALYSIS OF VORTEX DYNAMICS FOR SHALLOW TIDAL INLETS A Thesis by KERRI ANN WHILDEN Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements for the degree of MASTER OF SCIENCE Approved...

  7. MHK Projects/Highlands 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 Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 JumpCoos Bay OPTHalf Moon Cove TidalTidal Energy

  8. MHK Projects/Housatonic 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 Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 JumpCoos Bay OPTHalf Moon Cove TidalTidalHope

  9. Multiscale modeling and characterization for performance and safety of lithium-ion batteries

    SciTech Connect (OSTI)

    Pannala, Sreekanth; Turner, John A; Allu, Srikanth; Elwasif, Wael R; Kalnaus, Sergiy; Simunovic, Srdjan; Kumar, Abhishek; Billings, Jay Jay; Wang, Hsin; Nanda, Jagjit

    2015-01-01

    Lithium-ion batteries are highly complex electrochemical systems whose performance and safety are governed by coupled nonlinear electrochemical-electrical-thermal-mechanical processes over a range of spatiotemporal scales. In this paper we describe a new, open source computational framework for Lithium-ion battery simulations that is designed to support a variety of model types and formulations. This framework has been used to create three-dimensional cell and battery pack models that explicitly simulate all the battery components (current collectors, electrodes, and separator). The models are used to predict battery performance under normal operations and to study thermal and mechanical safety aspects under adverse conditions. The model development and validation are supported by experimental methods such as IR-imaging, X-ray tomography and micro-Raman mapping.

  10. On the Natural Frequency of Tidal Current Power Systems - A Discussion...

    Office of Scientific and Technical Information (OSTI)

    On the Natural Frequency of Tidal Current Power Systems - A Discussion of Sea Testing Citation Details In-Document Search Title: On the Natural Frequency of Tidal Current Power...

  11. Snacktime for Hungry Black Holes: Theoretical Studies of the Tidal Disruption of Stars

    E-Print Network [OSTI]

    Strubbe, Linda Elisabeth

    2011-01-01

    bound gas onto the BH powers the tidal disruption flare, andof an X-ray Power-law The candidate tidal disruption eventstidal disruption spectra will contain a high-energy power-

  12. 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,...

  13. Assessment of Energy Production Potential from Tidal Streams in the United States

    SciTech Connect (OSTI)

    Haas, Kevin A.; Fritz, Hermann M.; French, Steven P.; Smith, Brennan T.; Neary, Vincent

    2011-06-29

    The project documented in this report created a national database of tidal stream energy potential, as well as a GIS tool usable by industry in order to accelerate the market for tidal energy conversion technology.

  14. On the implications of incompressibility of the quantum mechanical wavefunction in the presence of tidal gravitational fields

    E-Print Network [OSTI]

    Minter, Stephen

    2010-01-01

    of being the tidal gravitational potential energy operator,the energy shift is negative, the tidal gravitational …eldtidal gravitational …eld is treated as a perturbation to the energy

  15. Evaluation of PV performance models and their impact on project risk.

    SciTech Connect (OSTI)

    Stein, Joshua S.; Hansen, Clifford W.; Cameron, Christopher P.

    2010-12-01

    Photovoltaic systems are often priced in $/W{sub p}, where Wp refers to the DC power rating of the modules at Standard Test Conditions (1000 W/m{sup 2}, 25 C cell temperature) and $ refers to the installed cost of the system. However, the true value of the system is in the energy it will produce in kWhs, not the power rating. System energy production is a function of the system design and location, the mounting configuration, the power conversion system, and the module technology, as well as the solar resource. Even if all other variables are held constant, the annual energy yield (kWh/kW{sup p}) will vary among module technologies because of differences in response to low-light levels and temperature. Understanding energy yield is a key part of understanding system value. System performance models are used during project development to estimate the expected output of PV systems for a given design and location. Performance modeling is normally done by the system designer/system integrator. Often, an independent engineer will also model system output during a due diligence review of a project. A variety of system performance models are available. The most commonly used modeling tool for project development and due diligence in the United States is probably PVsyst, while those seeking a quick answer to expected energy production may use PVWatts. In this paper, we examine the variation in predicted energy output among modeling tools and users and compare that to measured output.

  16. A Model-Based Impedance Control Scheme for High-Performance Hydraulic Joints

    E-Print Network [OSTI]

    Papadopoulos, Evangelos

    A Model-Based Impedance Control Scheme for High-Performance Hydraulic Joints Glen Bilodeau1, Greece Abstract Impedance control of a hydraulic servoactuator joint system is discussed in this paper individually. Due to nonlinear properties of hydraulic actuators, impedance control is difficult. The control

  17. Automated, Retargetable Back-Annotation for Host Compiled Performance and Power Modeling

    E-Print Network [OSTI]

    Gerstlauer, Andreas

    and back- annotation of basic code blocks with all possible predeces- sors. Results from applying ourAutomated, Retargetable Back-Annotation for Host Compiled Performance and Power Modeling Suhas typical front- and back-end optimiza- tions by working at the compiler-generated intermediate rep

  18. PERFORMANCE ANALYSIS OF INDUSTRIAL ETHERNET NETWORKS BY MEANS OF TIMED MODEL-CHECKING

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    technologies in manufacturing automation but they have not been specifically intended for industrial controlPERFORMANCE ANALYSIS OF INDUSTRIAL ETHERNET NETWORKS BY MEANS OF TIMED MODEL-CHECKING Daniel Witsch networks are promising for the harmonization of the communication technologies in manufacturing automation

  19. A Performance Model to Estimate Execution Time of Scientific Workflows on the Cloud

    E-Print Network [OSTI]

    Sakellariou, Rizos

    . In the evaluation, three real-world scientific workflows are used to compare the estimated makespan calculatedA Performance Model to Estimate Execution Time of Scientific Workflows on the Cloud Ilia Pietri.K Information Sciences Institute, University of Southern California, USA Abstract--Scientific workflows, which

  20. On a test of the modified BCS theory performance in the picket fence model

    E-Print Network [OSTI]

    Nguyen Dinh Dang

    2009-04-03

    The errors in the arguments, numerical results, and conclusions in the paper "Test of a modified BCS theory performance in the picket fence model" [Nucl. Phys. A 822 (2009) 1] by V.Yu. Ponomarev and A.I. Vdovin are pointed out. Its repetitions of already published material are also discussed.

  1. 2006 IEEE Electrical Performance of Electronic Packaging Efficient Modeling of Package Power Delivery Networks with

    E-Print Network [OSTI]

    Swaminathan, Madhavan

    73 2006 IEEE Electrical Performance of Electronic Packaging Efficient Modeling of Package Power* and Madhavan Swaminathan+ Kazuhide Uriu1 and Toru Yamada2 Packaging Research Centre EMC Design Group School are computationally expensive given the complexity of packaging structures in modern mixed signal systems. Fast

  2. VALIDATION OF PV PERFORMANCE MODELS USING SATELLITE-BASED IRRADIANCE MEASUREMENTS: A CASE STUDY

    E-Print Network [OSTI]

    Perez, Richard R.

    VALIDATION OF PV PERFORMANCE MODELS USING SATELLITE-BASED IRRADIANCE MEASUREMENTS: A CASE STUDY Clean Power Research Kirkland, WA e-mail: aparkins@cleanpower.com ABSTRACT Photovoltaic (PV) system and existing PV systems under a wide variety of environmental conditions. Ground based meteorological

  3. Modeling and Performance of MEMSBased Storage Devices John Linwood Griffin, Steven Schlosser, Gregory Ganger, David Nagle

    E-Print Network [OSTI]

    stores, and proved DRAM devices. storage technology, based on microelectromechanical systems (MEMS), hasModeling and Performance of MEMS­Based Storage Devices John Linwood Griffin, Steven Schlosser@cs.cmu.edu ABSTRACT MEMS-based storage devices seen many promis- alternatives to drives. Fabricated using conven

  4. Performance modeling and cell design for high concentration methanol fuel cells

    E-Print Network [OSTI]

    Chapter 50 Performance modeling and cell design for high concentration methanol fuel cells C. E The direct methanol fuel cell (DMFC) has become a lead- ing contender to replace the lithium-ion (Li density of liquid methanol (CH3OH) fuel is 4800 Wh l-1 , whereas the theoretical energy density of Li

  5. Scientific Programming 11 (2003) 159176 159 A performance-prediction model for PIC

    E-Print Network [OSTI]

    Vlad, Gregorio

    2003-01-01

    Scientific Programming 11 (2003) 159­176 159 IOS Press A performance-prediction model for PIC hierarchical workload decomposition strategies for particle in cell (PIC) codes on Clusters of Symmetric Multi of parallelization efficiency are compared with the predicted results. 1. Introduction Particle-in-cell (PIC

  6. Propagating Uncertainty in Solar Panel Performance for Life Cycle Modeling in Early Stage Design

    E-Print Network [OSTI]

    Yang, Maria

    Propagating Uncertainty in Solar Panel Performance for Life Cycle Modeling in Early Stage Design. This work is conducted in the context of an amorphous photovoltaic (PV) panel, using data gathered from the National Solar Radiation Database, as well as realistic data collected from an experimental hardware setup

  7. Better Buildings Neighborhood Program Business Models Guide: Home Performance Contractor Introduction

    Broader source: Energy.gov [DOE]

    The home performance contractor is a firm whose business is to deliver customized and complete home energy upgrade solutions directly to consumers. This is a relatively new contractor model; it addresses companies that provide services from the energy assessment stage of the home energy upgrade process through the installation and quality assurance stages.

  8. ARSA: A Sentiment-Aware Model for Predicting Sales Performance Using Blogs

    E-Print Network [OSTI]

    Huang, Jimmy

    ARSA: A Sentiment-Aware Model for Predicting Sales Performance Using Blogs Yang Liu1 , Xiangji, Toronto, Canada 2 School of Information Technology York University, Toronto, Canada yliu@cse.yorku.ca, jhuang@yorku.ca, aan@cse.yorku.ca, xhyu@yorku.ca ABSTRACT Due to its high popularity, Weblogs (or blogs

  9. An Estimate of Tidal Energy Lost to Turbulence at the Hawaiian Ridge JODY M. KLYMAK

    E-Print Network [OSTI]

    Balasubramanian, Ravi

    An Estimate of Tidal Energy Lost to Turbulence at the Hawaiian Ridge JODY M. KLYMAK Scripps an estimate of 3 1.5 GW of tidal energy lost to turbulence dissipation within 60 km of the ridge and Toole 1997). Another closely related question is that of where tidal energy gets removed from the ocean

  10. The E ect of Barriers on The Tidal Range in Yong Ming Tang

    E-Print Network [OSTI]

    interest in constructing tidal barrages, either to control the tide or to extract power. CorrespondinglyThe E ect of Barriers on The Tidal Range in Estuaries Yong Ming Tang Abstract Numerical simulations of the shallow water equations are used to study the e ect of topographic barriers on the tidal range

  11. Three-Dimensional Tidal Flow in an Elongated, Rotating Basin CLINTON D. WINANT

    E-Print Network [OSTI]

    Winant, Clinton D.

    Three-Dimensional Tidal Flow in an Elongated, Rotating Basin CLINTON D. WINANT Integrative-dimensional tidal circulation in an elongated basin of arbitrary depth is described with a linear, constant parcels tend to corkscrew into and out of the basin in a tidal period. The axial flow is only weakly

  12. 2306 JOURNAL OF THE ATMOSPHERIC SCIENCES Chaotic Trajectories of Tidally Perturbed Inertial Oscillations

    E-Print Network [OSTI]

    Boss, Emmanuel S.

    2306 JOURNAL OF THE ATMOSPHERIC SCIENCES Chaotic Trajectories of Tidally Perturbed Inertial ABSTRACT It is shown that tidal perturbations of a geopotential height in an inviscid, barot~opic atmos formulation of both ~he free, inertial, and the tidally forced problems permitted the application o~ the twi

  13. MARCH 2007 1 Tidal mixing hotspots governed by rapid parametric subharmonic instability

    E-Print Network [OSTI]

    MacKinnon, Jennifer

    at 21S demonstrate a rapid transfer of energy (over only a few days) to waves of half the tidal the generation site; overall 40 % of the tidal energy is dissipated locally. Further simulations indicate.9nearly 80 % of tidal energy is dissipated locally. Poleward of the critical latitude, M2/2

  14. Are mesoscale eddies in shelf seas formed by baroclinic instability of tidal fronts?

    E-Print Network [OSTI]

    Williams, Ric

    Are mesoscale eddies in shelf seas formed by baroclinic instability of tidal fronts? G. Badin,1 R; accepted 23 July 2009; published 27 October 2009. [1] The formation of eddies along tidal fronts signals are dampened by air-sea interaction and eroded by wind and tidal mixing. High-resolution CTD

  15. Critical bifurcation of shallow microtidal landforms in tidal flats and salt marshes

    E-Print Network [OSTI]

    Fagherazzi, Sergio

    Critical bifurcation of shallow microtidal landforms in tidal flats and salt marshes Sergio by the Editorial Board April 14, 2006 (received for review September 25, 2005) Shallow tidal basins are characterized by extensive tidal flats and salt marshes that lie within specific ranges of elevation, whereas

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

    E-Print Network [OSTI]

    to conserve wave energy. When propagating into the MLT region, the horizontal wind tidal amplitude can reachSeasonal variations of semidiurnal tidal perturbations in mesopause region temperature and zonal, Colorado (40.6°N, 105.1°W). The observed monthly results are in good agreement with MF radar tidal

  17. Spatial variability within a single parautochthonous Paratethyan tidal flat deposit (Karpatian, Lower Miocene Kleinebersdorf, Lower Austria)

    E-Print Network [OSTI]

    Zuschin, Martin

    Spatial variability within a single parautochthonous Paratethyan tidal flat deposit (Karpatian and Diplodonta rotundata points to a low-energy coastal setting with at least partly nutrient-rich sediment the interpretation of a parautochthonous to slightly transported tidal flat deposit. Key words: tidal flat, diversity

  18. Tidal and Wind Mixing versus Thermal Stratification in the South Atlantic Bight.

    E-Print Network [OSTI]

    North Carolina at Chapel Hill, University of

    ) these fluctuations are controlled by the cycles of tidally forced mixing, heat flux, wind and river discharge. During overcome the tendency for tidal power to produce a well-mixed system". Additionally, they expressed some: heat flux, evaporation-precipitation, fresh water input, wind stress work, bottom tidal work

  19. Virtual Seafloor Reduces Internal Wave Generation by Tidal Flow Likun Zhang*

    E-Print Network [OSTI]

    the applicability of linear theory to global predictions of the conversion of tidal energy into internal wave energy of the energy budget of the oceans requires a determination of the efficiency of conversion of tidal energyVirtual Seafloor Reduces Internal Wave Generation by Tidal Flow Likun Zhang* and Harry L. Swinney

  20. Using gaps in N-body tidal streams to probe missing satellites

    SciTech Connect (OSTI)

    Ngan, W. H. W.; Carlberg, R. G., E-mail: ngan@astro.utoronto.ca [Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S3H4 (Canada)

    2014-06-20

    We use N-body simulations to model the tidal disruption of a star cluster in a Milky-Way-sized dark matter halo, which results in a narrow stream comparable to (but slightly wider than) Pal-5 or GD-1. The mean Galactic dark matter halo is modeled by a spherical Navarro-Frenk-White potential with subhalos predicted by the ?CDM cosmological model. The distribution and mass function of the subhalos follow the results from the Aquarius simulation. We use a matched filter approach to look for 'gaps' in tidal streams at 12 length scales from 0.1 kpc to 5 kpc, which appear as characteristic dips in the linear densities along the streams. We find that, in addition to the subhalos' perturbations, the epicyclic overdensities (EOs) due to the coherent epicyclic motions of particles in a stream also produce gap-like signals near the progenitor. We measure the gap spectra—the gap formation rates as functions of gap length—due to both subhalo perturbations and EOs, which have not been accounted for together by previous studies. Finally, we project the simulated streams onto the sky to investigate issues when interpreting gap spectra in observations. In particular, we find that gap spectra from low signal-to-noise observations can be biased by the orbital phase of the stream. This indicates that the study of stream gaps will benefit greatly from high-quality data from future missions.

  1. SUMO, System performance assessment for a high-level nuclear waste repository: Mathematical models

    SciTech Connect (OSTI)

    Eslinger, P.W.; Miley, T.B.; Engel, D.W.; Chamberlain, P.J. II

    1992-09-01

    Following completion of the preliminary risk assessment of the potential Yucca Mountain Site by Pacific Northwest Laboratory (PNL) in 1988, the Office of Civilian Radioactive Waste Management (OCRWM) of the US Department of Energy (DOE) requested the Performance Assessment Scientific Support (PASS) Program at PNL to develop an integrated system model and computer code that provides performance and risk assessment analysis capabilities for a potential high-level nuclear waste repository. The system model that has been developed addresses the cumulative radionuclide release criteria established by the US Environmental Protection Agency (EPA) and estimates population risks in terms of dose to humans. The system model embodied in the SUMO (System Unsaturated Model) code will also allow benchmarking of other models being developed for the Yucca Mountain Project. The system model has three natural divisions: (1) source term, (2) far-field transport, and (3) dose to humans. This document gives a detailed description of the mathematics of each of these three divisions. Each of the governing equations employed is based on modeling assumptions that are widely accepted within the scientific community.

  2. High-Performance Computing Modeling Advances Accelerator Science for High-Energy Physics

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Amundson, James; Macridin, Alexandru; Spentzouris, Panagiotis

    2014-11-01

    The development and optimization of particle accelerators are essential for advancing our understanding of the properties of matter, energy, space and time. Particle accelerators are complex devices whose behavior involves many physical effects on multiple scales. Therefore, advanced computational tools utilizing high-performance computing (HPC) are essential for accurately modeling them. In the past decade, the DOE SciDAC program has produced such accelerator-modeling tools, which have beem employed to tackle some of the most difficult accelerator science problems. In this article we discuss the Synergia beam-dynamics framework and its applications to high-intensity particle accelerator physics. Synergia is an accelerator simulation packagemore »capable of handling the entire spectrum of beam dynamics simulations. We present the design principles, key physical and numerical models in Synergia and its performance on HPC platforms. Finally, we present the results of Synergia applications for the Fermilab proton source upgrade, known as the Proton Improvement Plan (PIP).« less

  3. High-Performance Computing Modeling Advances Accelerator Science for High-Energy Physics

    SciTech Connect (OSTI)

    Amundson, James; Macridin, Alexandru; Spentzouris, Panagiotis

    2014-11-01

    The development and optimization of particle accelerators are essential for advancing our understanding of the properties of matter, energy, space and time. Particle accelerators are complex devices whose behavior involves many physical effects on multiple scales. Therefore, advanced computational tools utilizing high-performance computing (HPC) are essential for accurately modeling them. In the past decade, the DOE SciDAC program has produced such accelerator-modeling tools, which have beem employed to tackle some of the most difficult accelerator science problems. In this article we discuss the Synergia beam-dynamics framework and its applications to high-intensity particle accelerator physics. Synergia is an accelerator simulation package capable of handling the entire spectrum of beam dynamics simulations. We present the design principles, key physical and numerical models in Synergia and its performance on HPC platforms. Finally, we present the results of Synergia applications for the Fermilab proton source upgrade, known as the Proton Improvement Plan (PIP).

  4. Identifying Pollutant Sources in Tidally Mixed Systems: Case Study

    E-Print Network [OSTI]

    Winant, Clinton D.

    sitessas a primary source of fecal indicator bacteria in the water column and subtidal sediments and magnitude of pollutant sources potentially responsible for the impairment. While this information mayIdentifying Pollutant Sources in Tidally Mixed Systems: Case Study of Fecal Indicator Bacteria from

  5. Squeezars: Tidally powered stars orbiting a massive black hole

    E-Print Network [OSTI]

    Alexander, T; Alexander, Tal; Morris, Mark

    2003-01-01

    We propose that there exists a class of transient sources, "squeezars", which are stars caught in highly eccentric orbits around a massive (m<10^8 Mo) black hole (MBH), whose atypically high luminosity (up to a significant fraction of their Eddington luminosity) is powered by tidal interactions with the MBH. Their existence follows from the presence of a mass sink, the MBH, in the galactic center, which drives a flow of stars into nearly radial orbits to replace those it has destroyed. We consider two limits for the stellar response to tidal heating: surface heating with radiative cooling ("hot squeezars") and bulk heating with adiabatic expansion ("cold squeezars"), and calculate the evolution of the squeezar orbit, size, luminosity and effective temperature. The squeezar formation rate is only ~0.05 that of tidal disruption flares, but squeezar lifetimes are many orders of magnitude longer, and so future observations of squeezars in nearby galaxies can probe the tidal process that feeds MBHs and the effe...

  6. General relativistic tidal work for Papapetrou, Weinberg and Goldberg pseudotensors

    E-Print Network [OSTI]

    So, Lau Loi

    2015-01-01

    In 1998 Thorne claimed that all pseudotensors give the same tidal work as the Newtonian theory. In 1999, Purdue used the Landau-Lifshitz pseudotensor to calculate the tidal heating and the result matched with the Newtonian gravity. Soon after in 2001, Favata employed the same method to examine the Einstein, Bergmann-Thomson and M{\\o}ller pseudotensors, all of them give the same result as Purdue did. Inspired by the work of Purdue and Favata, for the completeness, here we manipulate the tidal work for Papapetrou, Weinberg and Goldberg pseudotensors. We obtained the same tidal work as Purdue achieved. In addition, we emphasize that a suitable gravitational energy-momentum pseudotensor requires fulfill the inside matter condition and all of the classical pseudotensors pass this test except M$\\o$ller. Moreover, we constructed a general pseudotesnor which is modified by 13 linear artificial higher order terms combination with Einstein pseudotensor. We find that the result agrees with Thorne's prediction, i.e., rel...

  7. Squeezars: Tidally powered stars orbiting a massive black hole

    E-Print Network [OSTI]

    Tal Alexander; Mark Morris

    2003-05-05

    We propose that there exists a class of transient sources, "squeezars", which are stars caught in highly eccentric orbits around a massive (mpowered by tidal interactions with the MBH. Their existence follows from the presence of a mass sink, the MBH, in the galactic center, which drives a flow of stars into nearly radial orbits to replace those it has destroyed. We consider two limits for the stellar response to tidal heating: surface heating with radiative cooling ("hot squeezars") and bulk heating with adiabatic expansion ("cold squeezars"), and calculate the evolution of the squeezar orbit, size, luminosity and effective temperature. The squeezar formation rate is only ~0.05 that of tidal disruption flares, but squeezar lifetimes are many orders of magnitude longer, and so future observations of squeezars in nearby galaxies can probe the tidal process that feeds MBHs and the effects of extreme tides on stars. The mean number of squeezars orbiting the Galactic MBH is estimated at 0.1-1.

  8. Pasture and Soil Management Following Tidal Saltwater Intrusion 

    E-Print Network [OSTI]

    Provin, Tony; Redmon, Larry; McFarland, Mark L.; Feagley, Sam E.

    2009-05-26

    When land is flooded by saltwater, as after a hurricane tidal surge, it can long-term effects on soil productivity and fertility. This publication explains how to reclaim flooded pasture land. Having soil tested for salinity is an important step....

  9. Examining the Impacts of Tidal Energy Capture from an Ecosystem

    E-Print Network [OSTI]

    Leslie, Heather

    ; however, the contribution of alternative fuel sources to overall energy is still small. In the United are under development in the Northeast, includ- ing Roosevelt Island in New York City's East RiverP A P E R Examining the Impacts of Tidal Energy Capture from an Ecosystem Services Perspective A U

  10. Tidal Conversion by Supercritical Topography NEIL J. BALMFORTH

    E-Print Network [OSTI]

    Balmforth, Neil

    Tidal Conversion by Supercritical Topography NEIL J. BALMFORTH University of British Columbia topography on the ocean floor. The ocean is treated as infinitely deep, and the topography consists. The calculations extend the previous results of Balmforth et al. for subcritical topography (wherein waves

  11. First-post-Newtonian quadrupole tidal interactions in binary systems

    E-Print Network [OSTI]

    Justin Vines; Éanna É. Flanagan

    2014-10-09

    We consider tidal coupling in a binary stellar system to first-post-Newtonian order. We derive the orbital equations of motion for bodies with spins and mass quadrupole moments and show that they conserve the total linear momentum of the binary. We note that spin-orbit coupling must be included in a 1PN treatment of tidal interactions in order to maintain consistency (except in the special case of adiabatically induced quadrupoles); inclusion of 1PN quadrupolar tidal effects while omitting spin effects would lead to a failure of momentum conservation for generic evolution of the quadrupoles. We use momentum conservation to specialize our analysis to the system's center-of-mass-energy frame; we find the binary's relative equation of motion in this frame and also present a generalized Lagrangian from which it can be derived. We then specialize to the case in which the quadrupole moment is adiabatically induced by the tidal field (in which case it is consistent to ignore spin effects). We show how the adiabatic dynamics for the quadrupole can be incorporated into our action principle and present the simplified orbital equations of motion and conserved energy for the adiabatic case. These results are relevant to gravitational wave signals from inspiralling binary neutron stars.

  12. Performance Modeling of an Air-Based Photovoltaic/Thermal (PV/T) Collector

    SciTech Connect (OSTI)

    Casey, R. D.; Brandemuehl, M. J.; Merrigan, T.; Burch, J.

    2010-01-01

    This paper studies a collector design that utilizes unglazed photovoltaic/thermal (PV/T) collectors preheating air for glazed air heating modules. The performance modeling of these collectors is examined both individually and in series. For each collector type, a dynamic, finite difference, first-law model has been created using literature correlations for friction. The models were compared to performance data, calibrating the models by scaling of friction terms for best fit. The calibrated models generally agree well with the experimental data; even during sudden changes to ambient conditions. The root mean square error between the unglazed PV/T model and experiment results for the useful thermal energy gain and the outlet air temperature are 7.12 W/m{sup 2} and 1.07 C, respectively. The annual source energy performance of the building-integrated PV/T (BIPV/T) array is then simulated for residential applications in seven climate zones of the United States of America. The performance of the BIPV/T array is characterized by the amount of net electrical energy and useful thermal energy produced. The useful thermal energy is defined as the amount of energy offset by the BIPV/T system for water heating and space conditioning. A BIPV/T system composed 87.5% of PV modules, and 12.5% of glazed air heating modules, offsets the same amount of source energy as a roof-mounted PV system of the same area. This array composition increases the thermal energy gain by 47% over a BIPV/T array composed solely of PV modules.

  13. Energy Localization Invariance of Tidal Work in General Relativity

    E-Print Network [OSTI]

    Marc Favata

    2000-08-24

    It is well known that, when an external general relativistic (electric-type) tidal field E(t) interacts with the evolving quadrupole moment I(t) of an isolated body, the tidal field does work on the body (``tidal work'') -- i.e., it transfers energy to the body -- at a rate given by the same formula as in Newtonian theory: dW/dt = -1/2 E dI/dt. Thorne has posed the following question: In view of the fact that the gravitational interaction energy between the tidal field and the body is ambiguous by an amount of order E(t)I(t), is the tidal work also ambiguous by this amount, and therefore is the formula dW/dt = -1/2 E dI/dt only valid unambiguously when integrated over timescales long compared to that for I(t) to change substantially? This paper completes a demonstration that the answer is no; dW/dt is not ambiguous in this way. More specifically, this paper shows that dW/dt is unambiguously given by -1/2 E dI/dt independently of one's choice of how to localize gravitational energy in general relativity. This is proved by explicitly computing dW/dt using various gravitational stress-energy pseudotensors (Einstein, Landau-Lifshitz, Moller) as well as Bergmann's conserved quantities which generalize many of the pseudotensors to include an arbitrary function of position. A discussion is also given of the problem of formulating conservation laws in general relativity and the role played by the various pseudotensors.

  14. Seasonal versus Episodic Performance Evaluation for an Eulerian Photochemical Air Quality Model

    SciTech Connect (OSTI)

    Jin, Ling; Brown, Nancy J.; Harley, Robert A.; Bao, Jian-Wen; Michelson, Sara A; Wilczak, James M

    2010-04-16

    This study presents detailed evaluation of the seasonal and episodic performance of the Community Multiscale Air Quality (CMAQ) modeling system applied to simulate air quality at a fine grid spacing (4 km horizontal resolution) in central California, where ozone air pollution problems are severe. A rich aerometric database collected during the summer 2000 Central California Ozone Study (CCOS) is used to prepare model inputs and to evaluate meteorological simulations and chemical outputs. We examine both temporal and spatial behaviors of ozone predictions. We highlight synoptically driven high-ozone events (exemplified by the four intensive operating periods (IOPs)) for evaluating both meteorological inputs and chemical outputs (ozone and its precursors) and compare them to the summer average. For most of the summer days, cross-domain normalized gross errors are less than 25% for modeled hourly ozone, and normalized biases are between {+-}15% for both hourly and peak (1 h and 8 h) ozone. The domain-wide aggregated metrics indicate similar performance between the IOPs and the whole summer with respect to predicted ozone and its precursors. Episode-to-episode differences in ozone predictions are more pronounced at a subregional level. The model performs consistently better in the San Joaquin Valley than other air basins, and episodic ozone predictions there are similar to the summer average. Poorer model performance (normalized peak ozone biases <-15% or >15%) is found in the Sacramento Valley and the Bay Area and is most noticeable in episodes that are subject to the largest uncertainties in meteorological fields (wind directions in the Sacramento Valley and timing and strength of onshore flow in the Bay Area) within the boundary layer.

  15. A STATISTICAL METHOD FOR MEASURING THE GALACTIC POTENTIAL AND TESTING GRAVITY WITH COLD TIDAL STREAMS

    SciTech Connect (OSTI)

    Penarrubia, Jorge; Walker, Matthew G.

    2012-11-20

    We introduce the Minimum Entropy Method, a simple statistical technique for constraining the Milky Way gravitational potential and simultaneously testing different gravity theories directly from 6D phase-space surveys and without adopting dynamical models. We demonstrate that orbital energy distributions that are separable (i.e., independent of position) have an associated entropy that increases under wrong assumptions about the gravitational potential and/or gravity theory. Of known objects, 'cold' tidal streams from low-mass progenitors follow orbital distributions that most nearly satisfy the condition of separability. Although the orbits of tidally stripped stars are perturbed by the progenitor's self-gravity, systematic variations of the energy distribution can be quantified in terms of the cross-entropy of individual tails, giving further sensitivity to theoretical biases in the host potential. The feasibility of using the Minimum Entropy Method to test a wide range of gravity theories is illustrated by evolving restricted N-body models in a Newtonian potential and examining the changes in entropy introduced by Dirac, MONDian, and f(R) gravity modifications.

  16. IDENTIFICATION OF A GENERAL MODEL FOR THE MPP PERFORMANCE OF PV-MODULES FOR THE APPLICATION IN A PROCEDURE FOR THE PERFORMANCE CHECK

    E-Print Network [OSTI]

    Heinemann, Detlev

    IDENTIFICATION OF A GENERAL MODEL FOR THE MPP PERFORMANCE OF PV-MODULES FOR THE APPLICATION. ABSTRACT: To assure the maximal energy yield of grid connected PV systems, system faults have of this model for the application to grid connected PV systems using cSi, aSi and CIS modules is demonstrated. 1

  17. Evaluation of Model Results and Measured Performance of Net-Zero Energy Homes in Hawaii: Preprint

    SciTech Connect (OSTI)

    Norton, P.; Kiatreungwattana, K.; Kelly, K. J.

    2013-03-01

    The Kaupuni community consists of 19 affordable net-zero energy homes that were built within the Waianae Valley of Oahu, Hawaii in 2011. The project was developed for the native Hawaiian community led by the Department of Hawaiian Homelands. This paper presents a comparison of the modeled and measured energy performance of the homes. Over the first year of occupancy, the community as a whole performed within 1% of the net-zero energy goals. The data show a range of performance from house to house with the majority of the homes consistently near or exceeding net-zero, while a few fall short of the predicted net-zero energy performance. The impact of building floor plan, weather, and cooling set point on this comparison is discussed. The project demonstrates the value of using building energy simulations as a tool to assist the project to achieve energy performance goals. Lessons learned from the energy performance monitoring has had immediate benefits in providing feedback to the homeowners, and will be used to influence future energy efficient designs in Hawaii and other tropical climates.

  18. SIMPLIFIED PREDICTIVE MODELS FOR CO? SEQUESTRATION PERFORMANCE ASSESSMENT RESEARCH TOPICAL REPORT ON TASK #3 STATISTICAL LEARNING BASED MODELS

    SciTech Connect (OSTI)

    Mishra, Srikanta; Schuetter, Jared

    2014-11-01

    We compare two approaches for building a statistical proxy model (metamodel) for CO? geologic sequestration from the results of full-physics compositional simulations. The first approach involves a classical Box-Behnken or Augmented Pairs experimental design with a quadratic polynomial response surface. The second approach used a space-filling maxmin Latin Hypercube sampling or maximum entropy design with the choice of five different meta-modeling techniques: quadratic polynomial, kriging with constant and quadratic trend terms, multivariate adaptive regression spline (MARS) and additivity and variance stabilization (AVAS). Simulations results for CO? injection into a reservoir-caprock system with 9 design variables (and 97 samples) were used to generate the data for developing the proxy models. The fitted models were validated with using an independent data set and a cross-validation approach for three different performance metrics: total storage efficiency, CO? plume radius and average reservoir pressure. The Box-Behnken–quadratic polynomial metamodel performed the best, followed closely by the maximin LHS–kriging metamodel.

  19. Science-Based Simulation Model of Human Performance for Human Reliability Analysis

    SciTech Connect (OSTI)

    Dana L. Kelly; Ronald L. Boring; Ali Mosleh; Carol Smidts

    2011-10-01

    Human reliability analysis (HRA), a component of an integrated probabilistic risk assessment (PRA), is the means by which the human contribution to risk is assessed, both qualitatively and quantitatively. However, among the literally dozens of HRA methods that have been developed, most cannot fully model and quantify the types of errors that occurred at Three Mile Island. Furthermore, all of the methods lack a solid empirical basis, relying heavily on expert judgment or empirical results derived in non-reactor domains. Finally, all of the methods are essentially static, and are thus unable to capture the dynamics of an accident in progress. The objective of this work is to begin exploring a dynamic simulation approach to HRA, one whose models have a basis in psychological theories of human performance, and whose quantitative estimates have an empirical basis. This paper highlights a plan to formalize collaboration among the Idaho National Laboratory (INL), the University of Maryland, and The Ohio State University (OSU) to continue development of a simulation model initially formulated at the University of Maryland. Initial work will focus on enhancing the underlying human performance models with the most recent psychological research, and on planning follow-on studies to establish an empirical basis for the model, based on simulator experiments to be carried out at the INL and at the OSU.

  20. Performance Engineering of the Community Climate System Model (PECCSM) PRINCIPAL INVESTIGATOR: Patrick H. Worley (Co-PI with

    E-Print Network [OSTI]

    performance computing systems. The CCSM has evolved recently to become a first-generation Earth system model, and has been renamed the Community Earth System Model (CESM). The CESM will be used to explore new science

  1. Improving the performance of a Dutch CSR by modeling within-word and cross-word pronunciation variation 

    E-Print Network [OSTI]

    Kessens, Judith M; Wester, Mirjam; Strik, Helmer

    1999-01-01

    This article describes how the performance of a Dutch continuous speech recognizer was improved by modeling pronunciation variation. We propose a general procedure for modeling pronunciation variation. In short, it consists ...

  2. Fuel Performance Experiments and Modeling: Fission Gas Bubble Nucleation and Growth in Alloy Nuclear Fuels

    SciTech Connect (OSTI)

    McDeavitt, Sean; Shao, Lin; Tsvetkov, Pavel; Wirth, Brian; Kennedy, Rory

    2014-04-07

    Advanced fast reactor systems being developed under the DOE's Advanced Fuel Cycle Initiative are designed to destroy TRU isotopes generated in existing and future nuclear energy systems. Over the past 40 years, multiple experiments and demonstrations have been completed using U-Zr, U-Pu-Zr, U-Mo and other metal alloys. As a result, multiple empirical and semi-empirical relationships have been established to develop empirical performance modeling codes. Many mechanistic questions about fission as mobility, bubble coalescience, and gas release have been answered through industrial experience, research, and empirical understanding. The advent of modern computational materials science, however, opens new doors of development such that physics-based multi-scale models may be developed to enable a new generation of predictive fuel performance codes that are not limited by empiricism.

  3. Structural Models and Endogeneity in Corporate Finance: The Link Between Managerial Ownership and Corporate Performance

    E-Print Network [OSTI]

    Coles, Jeffrey L.; Lemmon, Michael L.; Meschke, Felix

    2012-01-01

    Jeffrey L. Coles Arizona State University (ASU) - Finance Department Michael L. Lemmon University of Utah - Department of Finance Felix Meschke University of Kansas - Finance Area This version: April 14, 2011 Paper citation: Jeffrey L.... Coles, Michael L. Lemmon, J. Felix Meschke, Structural models and endogeneity in corporate finance: The link between managerial ownership and corporate performance, Journal of Financial Economics, Volume 103, Issue 1, January 2012, Pages 149-168, ISSN...

  4. Performance Assessment Modeling and Sensitivity Analyses of Generic Disposal System Concepts.

    SciTech Connect (OSTI)

    Sevougian, S. David; Freeze, Geoffrey A.; Gardner, William Payton; Hammond, Glenn Edward; Mariner, Paul

    2014-09-01

    directly, rather than through simplified abstractions. It also a llows for complex representations of the source term, e.g., the explicit representation of many individual waste packages (i.e., meter - scale detail of an entire waste emplacement drift). This report fulfills the Generic Disposal System Analysis Work Packa ge Level 3 Milestone - Performance Assessment Modeling and Sensitivity Analyses of Generic Disposal System Concepts (M 3 FT - 1 4 SN08080 3 2 ).

  5. Modeling and Quantification of Team Performance in Human Reliability Analysis for Probabilistic Risk Assessment

    SciTech Connect (OSTI)

    Jeffrey C. JOe; Ronald L. Boring

    2014-06-01

    Probabilistic Risk Assessment (PRA) and Human Reliability Assessment (HRA) are important technical contributors to the United States (U.S.) Nuclear Regulatory Commission’s (NRC) risk-informed and performance based approach to regulating U.S. commercial nuclear activities. Furthermore, all currently operating commercial NPPs in the U.S. are required by federal regulation to be staffed with crews of operators. Yet, aspects of team performance are underspecified in most HRA methods that are widely used in the nuclear industry. There are a variety of "emergent" team cognition and teamwork errors (e.g., communication errors) that are 1) distinct from individual human errors, and 2) important to understand from a PRA perspective. The lack of robust models or quantification of team performance is an issue that affects the accuracy and validity of HRA methods and models, leading to significant uncertainty in estimating HEPs. This paper describes research that has the objective to model and quantify team dynamics and teamwork within NPP control room crews for risk informed applications, thereby improving the technical basis of HRA, which improves the risk-informed approach the NRC uses to regulate the U.S. commercial nuclear industry.

  6. Climate Modeling using High-Performance Computing The Center for Applied Scientific Computing (CASC) and the LLNL Climate and Carbon

    E-Print Network [OSTI]

    and NCAR in the development of a comprehensive, earth systems model. This model incorporates the most-performance climate models. Through the addition of relevant physical processes, we are developing an earth systems modeling capability as well. Our collaborators in climate research include the National Center

  7. Reference Model #1 - Tidal Energy: Resource Dr. Brian Polagye

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMassR&D100 Winners * Impactsand engineersAcquisition Officereference

  8. An Approach to Enhance pnetCDF Performance in Environmental Modeling Applications

    SciTech Connect (OSTI)

    Wong, David; Yang, Cheng-En; Fu, Joshua S.; Wong, Kwai; Gao, Yang

    2015-01-01

    I/O has been considered as a bottleneck in parallel applications. The software package, pnetCDF which works with parallel file systems, was developed to address this issue and provide parallel I/O capability. This study examines the performance of a novel approach which performs data aggregation along either row or column dimension of the spatial domain, and then applies the pnetCDF parallel I/O paradigm. The test was done with three different domain sizes which represents small, moderately large and large data domains, using a small scale Community Multi-scale Air Quality model (CMAQ) mocked up code. The examination includes comparing I/O performance with traditional serial I/O technique, straight application of pnetCDF, and the data aggregation along row and column dimension before applying pnetCDF. After the comparison, “optimal” I/O configurations for this new novel approach were quantified. Data aggregation along the row dimension (pnetCDFcr) works better than along the column dimension (pnetCDFcc) although it may perform slightly worse than straight the pnetCDF method with a small number of processors. When the number of processors becomes larger, pnetCDFcr out performs pnetCDF significantly. If the number of processors keeps increasing, pnetCDF reaches a point that the performance is even worse than the serial I/O technique. This new approach has also been tested on a real application where it performs two times better than the straight pnetCDF paradigm.

  9. Modeling the performance and cost of lithium-ion batteries for electric-drive vehicles.

    SciTech Connect (OSTI)

    Nelson, P. A. Gallagher, K. G. Bloom, I. Dees, D. W.

    2011-10-20

    This report details the Battery Performance and Cost model (BatPaC) developed at Argonne National Laboratory for lithium-ion battery packs used in automotive transportation. The model designs the battery for a specified power, energy, and type of vehicle battery. The cost of the designed battery is then calculated by accounting for every step in the lithium-ion battery manufacturing process. The assumed annual production level directly affects each process step. The total cost to the original equipment manufacturer calculated by the model includes the materials, manufacturing, and warranty costs for a battery produced in the year 2020 (in 2010 US$). At the time this report is written, this calculation is the only publically available model that performs a bottom-up lithium-ion battery design and cost calculation. Both the model and the report have been publically peer-reviewed by battery experts assembled by the U.S. Environmental Protection Agency. This report and accompanying model include changes made in response to the comments received during the peer-review. The purpose of the report is to document the equations and assumptions from which the model has been created. A user of the model will be able to recreate the calculations and perhaps more importantly, understand the driving forces for the results. Instructions for use and an illustration of model results are also presented. Almost every variable in the calculation may be changed by the user to represent a system different from the default values pre-entered into the program. The distinct advantage of using a bottom-up cost and design model is that the entire power-to-energy space may be traversed to examine the correlation between performance and cost. The BatPaC model accounts for the physical limitations of the electrochemical processes within the battery. Thus, unrealistic designs are penalized in energy density and cost, unlike cost models based on linear extrapolations. Additionally, the consequences on cost and energy density from changes in cell capacity, parallel cell groups, and manufacturing capabilities are easily assessed with the model. New proposed materials may also be examined to translate bench-scale values to the design of full-scale battery packs providing realistic energy densities and prices to the original equipment manufacturer. The model will be openly distributed to the public in the year 2011. Currently, the calculations are based in a Microsoft{reg_sign} Office Excel spreadsheet. Instructions are provided for use; however, the format is admittedly not user-friendly. A parallel development effort has created an alternate version based on a graphical user-interface that will be more intuitive to some users. The version that is more user-friendly should allow for wider adoption of the model.

  10. POSSIBLE ORIGIN OF THE G2 CLOUD FROM THE TIDAL DISRUPTION OF A KNOWN GIANT STAR BY SGR A*

    SciTech Connect (OSTI)

    Guillochon, James; Loeb, Abraham [Harvard-Smithsonian Center for Astrophysics, The Institute for Theory and Computation, 60 Garden Street, Cambridge, MA 02138 (United States); MacLeod, Morgan; Ramirez-Ruiz, Enrico, E-mail: jguillochon@cfa.harvard.edu [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

    2014-05-10

    The discovery of the gas cloud G2 on a near-radial orbit about Sgr A* has prompted much speculation on its origin. In this Letter, we propose that G2 formed out of the debris stream produced by the removal of mass from the outer envelope of a nearby giant star. We perform hydrodynamical simulations of the returning tidal debris stream with cooling and find that the stream condenses into clumps that fall periodically onto Sgr A*. We propose that one of these clumps is the observed G2 cloud, with the rest of the stream being detectable at lower Br? emissivity along a trajectory that would trace from G2 to the star that was partially disrupted. By simultaneously fitting the orbits of S2, G2, and ?2000 candidate stars, and by fixing the orbital plane of each candidate star to G2 (as is expected for a tidal disruption), we find that several stars have orbits that are compatible with the notion that one of them was tidally disrupted to produce G2. If one of these stars were indeed disrupted, it last encountered Sgr A* hundreds of years ago and has likely encountered Sgr A* repeatedly. However, while these stars are compatible with the giant disruption scenario given their measured positions and proper motions, their radial velocities are currently unknown. If one of these stars' radial velocity is measured to be compatible with a disruptive orbit, it would strongly suggest that its disruption produced G2.

  11. Tidal dissipation in a homogeneous spherical body. I. Methods

    SciTech Connect (OSTI)

    Efroimsky, Michael; Makarov, Valeri V. E-mail: vvm@usno.navy.mil

    2014-11-01

    A formula for the tidal dissipation rate in a spherical body is derived from first principles to correct some mathematical inaccuracies found in the literature. The development is combined with the Darwin-Kaula formalism for tides. Our intermediate results are compared with those by Zschau and Platzman. When restricted to the special case of an incompressible spherical planet spinning synchronously without libration, our final formula can be compared with the commonly used expression from Peale and Cassen. However, the two turn out to differ, as in our expression the contributions from all Fourier modes are positive-definite, which is not the case with the formula from Peale and Cassen. Examples of the application of our expression for the tidal damping rate are provided in the work by Makarov and Efroimsky (Paper II) published back to back with the current paper.

  12. A scaling relation of the evolving tidal fields in a ?CDM cosmology

    SciTech Connect (OSTI)

    Lee, Jounghun [Astronomy Program, FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Springel, Volker, E-mail: jounghun@astro.snu.ac.kr, E-mail: volker@mpa-garching.mpg.de [Max-Planck Institut fuer Astrophysik, Karl-Schwarzschild Strasse 1, D-85748 Garching (Germany)

    2010-05-01

    We report the finding of a scaling relation among the cosmic-web anisotropy parameter A, the linear density rms fluctuation ?(r) and the linear growth factor D(z). Using the tidal field derived from the Millennium Simulation on 512{sup 3} grids at z = 0,2,5 and 127, we calculate the largest eigenvalues ? of the local tidal tensor at each grid resolution and measure its distance-averaged two-point correlation function, ?{sub ?}, as a function of the cosines of polar angles cos ? in the local principal axis frame. We show that ?{sub ?} is quite anisotropic, increasing toward the directions of minimal matter compression, and that the anisotropy of ?{sub ?} increases as the redshift z decreases and as the upper distance cutoff r{sub c} decreases. Fitting the numerical results to an analytic fitting model ?{sub ?}(cos ?)?(1+Acos {sup n}?){sup ?1}, it is found that the best fit value of A, dubbed the cosmic-web anisotropy parameter, varies systematically with ?(r{sub c}) and D(z), allowing us to determine the simple empiral scaling relation A(r{sub c},z) = 0.8 D{sup 0.76}(z) ?(r{sub c})

  13. On large and small tidal lags. The virtual identity of two rheophysical theories

    E-Print Network [OSTI]

    Ferraz-Mello, Sylvio

    2015-01-01

    The aim of this letter is to discuss the virtual identity of two recent tidal theories: the creep tide theory of Ferraz-Mello (Cel. Mech. Dyn. Astron. 116, 109, 2013) and the Maxwell model developed by Correia et al. (Astron. Astrophys. 571, A50, 2014). It includes the discussion of the basic equations of the theories, which, in both cases, include an elastic and an anelastic component, and shows that the basic equations of the two theories are equivalent and differ by only a numerical factor in the anelastic tide. It also includes a discussion of the lags: the lag of the full tide (geodetic), dominated by the elastic component, and the phase of the anelastic tide. In rotating rocky bodies not trapped in a spin-orbit resonance (e.g., the Earth) the geodetic lag is close to zero and the phase of the anelastic tide is close to 90 degrees. The results obtained from combining tidal solutions from satellite tracking data and from Topex/Poseidon satellite altimeter data, by Ray et al., are extended to determine the...

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

    E-Print Network [OSTI]

    Euaggelos E. Zotos

    2014-11-18

    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.

  15. Probing the tidal disruption flares of massive black holes with high-energy neutrinos

    E-Print Network [OSTI]

    Wang, Xiang-Yu; Dai, Zi-Gao; Cheng, K S

    2011-01-01

    The recently discovered high-energy transient Swift J164449.3+573451 (Sw J1644+57) is thought to arise from the tidal disruption of a passing star by a dormant massive black hole. Modeling of the broadband emission suggests the presence of a powerful relativistic jet, which contributes dominantly to the observed X-ray emission. Here we suggest that high energy protons accelerated by internal shocks in the jets produce ~0.1-10 PeV neutrinos through photomeson interactions with X-ray photons. The large X-ray fluence (7*10^{-4} erg cm^{-2}) and high photopion efficiency, together with the insignificant cooling of secondary mesons, result in bright neutrino emission expected from Sw J1644+57 if the jet composition is matter-dominated. One to several neutrinos may be detected by a Km^3-scale detector from one tidal disruption event similar to Sw J1644+57, thereby providing a powerful probe of the composition of the jets.

  16. High-Performance Computer Modeling of the Cosmos-Iridium Collision

    SciTech Connect (OSTI)

    Olivier, S; Cook, K; Fasenfest, B; Jefferson, D; Jiang, M; Leek, J; Levatin, J; Nikolaev, S; Pertica, A; Phillion, D; Springer, K; De Vries, W

    2009-08-28

    This paper describes the application of a new, integrated modeling and simulation framework, encompassing the space situational awareness (SSA) enterprise, to the recent Cosmos-Iridium collision. This framework is based on a flexible, scalable architecture to enable efficient simulation of the current SSA enterprise, and to accommodate future advancements in SSA systems. In particular, the code is designed to take advantage of massively parallel, high-performance computer systems available, for example, at Lawrence Livermore National Laboratory. We will describe the application of this framework to the recent collision of the Cosmos and Iridium satellites, including (1) detailed hydrodynamic modeling of the satellite collision and resulting debris generation, (2) orbital propagation of the simulated debris and analysis of the increased risk to other satellites (3) calculation of the radar and optical signatures of the simulated debris and modeling of debris detection with space surveillance radar and optical systems (4) determination of simulated debris orbits from modeled space surveillance observations and analysis of the resulting orbital accuracy, (5) comparison of these modeling and simulation results with Space Surveillance Network observations. We will also discuss the use of this integrated modeling and simulation framework to analyze the risks and consequences of future satellite collisions and to assess strategies for mitigating or avoiding future incidents, including the addition of new sensor systems, used in conjunction with the Space Surveillance Network, for improving space situational awareness.

  17. Quantum modeling of thermoelectric performance of strained Si/Ge/Si superlattices using the nonequilibrium Green's function method

    E-Print Network [OSTI]

    Walker, D. Greg

    Quantum modeling of thermoelectric performance of strained Si/Ge/Si superlattices using 2007 The cross-plane thermoelectric performance of strained Si/Ge/Si superlattices is studied from such that thermoelectric performance is independent of layer thickness between 2 and 4 nm germanium barrier layers

  18. 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.

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

    E-Print Network [OSTI]

    Austin, George Belden

    1953-01-01

    of Symbols, Tables ~ . . . I, INTRODUCTION Historical B. Classification of Estuaries C. Ob]ectives II. GENERAL DISCUSSION OF NOBILE BAY A. Geomorphological B. Geological C. Biological iii ~ ~ vi ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ o sic.... Collection of Data 27 2B V, ANALYSIS OF THE DATA A. Methods B. Distribution of Temperature, Salinity, and Fresh Water Page 30 30 C. Circulation D. Mass Transport . E. Tidal Flushing of Mobile Bay . VI ~ SUMMAHY AND CONCLUSIONS VII, BIBLIOGRAPHY...

  20. Severn Tidal Power Group STpg | 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 Home Page| Open Energy Information Serbia-Enhancing Capacity for Low Emission DevelopmentLakes, North Carolina:Severn Tidal

  1. Evaluation of Blade-Strike Models for Estimating the Biological Performance of Large Kaplan Hydro Turbines

    SciTech Connect (OSTI)

    Deng, Zhiqun; Carlson, Thomas J.; Ploskey, Gene R.; Richmond, Marshall C.

    2005-11-30

    BioIndex testing of hydro-turbines is sought as an analog to the hydraulic index testing conducted on hydro-turbines to optimize their power production efficiency. In BioIndex testing the goal is to identify those operations within the range identified by Index testing where the survival of fish passing through the turbine is maximized. BioIndex testing includes the immediate tailrace region as well as the turbine environment between a turbine's intake trashracks and the exit of its draft tube. The US Army Corps of Engineers and the Department of Energy have been evaluating a variety of means, such as numerical and physical turbine models, to investigate the quality of flow through a hydro-turbine and other aspects of the turbine environment that determine its safety for fish. The goal is to use these tools to develop hypotheses identifying turbine operations and predictions of their biological performance that can be tested at prototype scales. Acceptance of hypotheses would be the means for validation of new operating rules for the turbine tested that would be in place when fish were passing through the turbines. The overall goal of this project is to evaluate the performance of numerical blade strike models as a tool to aid development of testable hypotheses for bioIndexing. Evaluation of the performance of numerical blade strike models is accomplished by comparing predictions of fish mortality resulting from strike by turbine runner blades with observations made using live test fish at mainstem Columbia River Dams and with other predictions of blade strike made using observations of beads passing through a 1:25 scale physical turbine model.

  2. Forced libration of tidally synchronized planets and moons

    E-Print Network [OSTI]

    Makarov, Valeri V; Dorland, Bryan

    2015-01-01

    Tidal dissipation of kinetic energy, when it is strong enough, tends to synchronize the rotation of planets and moons with the mean orbital motion, or drive it into long-term stable spin-orbit resonances. As the orbital motion undergoes periodic acceleration due to a finite orbital eccentricity, the spin rate oscillates around the equilibrium mean value too, giving rise to the forced, or eccentricity-driven, librations. Both the shape and amplitude of forced librations of synchronous viscoelastic planets and moons are defined by a combination of two different types of perturbative torque, the tidal torque and the triaxial torque. Consequently, forced librations can be tidally dominated (e.g., Io and possibly Titan) or deformation-dominated (e.g., the Moon) depending on a set of orbital, rheological, and other physical parameters. With small eccentricities, for the former kind, the largest term in the libration angle can be minus cosine of the mean anomaly, whereas for the latter kind, it is minus sine of the ...

  3. The Arches Cluster: Extended Structure and Tidal Radius

    E-Print Network [OSTI]

    Hosek, Matthew W; Anderson, Jay; Ghez, Andrea M; Morris, Mark R; Clarkson, William I

    2015-01-01

    At a projected distance of ~26 pc from Sgr A*, the Arches cluster provides insight to star formation in the extreme Galactic Center (GC) environment. Despite its importance, many key properties such as the cluster's internal structure and orbital history are not well known. We present an astrometric and photometric study of the outer region of the Arches cluster (R > 6.25") using HST WFC3IR. Using proper motions we calculate membership probabilities for stars down to F153M = 20 mag (~2.5 M_sun) over a 120" x 120" field of view, an area 144 times larger than previous astrometric studies of the cluster. We construct the radial profile of the Arches to a radius of 75" (~3 pc at 8 kpc), which can be well described by a single power law. From this profile we place a 3-sigma lower limit of 2.8 pc on the observed tidal radius, which is larger than the predicted tidal radius (1 - 2.5 pc). Evidence of mass segregation is observed throughout the cluster and no tidal tail structures are apparent along the orbital path. ...

  4. In-Service Design & Performance Prediction of Advanced Fusion Material Systems by Computational Modeling and Simulation

    SciTech Connect (OSTI)

    G. R. Odette; G. E. Lucas

    2005-11-15

    This final report on "In-Service Design & Performance Prediction of Advanced Fusion Material Systems by Computational Modeling and Simulation" (DE-FG03-01ER54632) consists of a series of summaries of work that has been published, or presented at meetings, or both. It briefly describes results on the following topics: 1) A Transport and Fate Model for Helium and Helium Management; 2) Atomistic Studies of Point Defect Energetics, Dynamics and Interactions; 3) Multiscale Modeling of Fracture consisting of: 3a) A Micromechanical Model of the Master Curve (MC) Universal Fracture Toughness-Temperature Curve Relation, KJc(T - To), 3b) An Embrittlement DTo Prediction Model for the Irradiation Hardening Dominated Regime, 3c) Non-hardening Irradiation Assisted Thermal and Helium Embrittlement of 8Cr Tempered Martensitic Steels: Compilation and Analysis of Existing Data, 3d) A Model for the KJc(T) of a High Strength NFA MA957, 3e) Cracked Body Size and Geometry Effects of Measured and Effective Fracture Toughness-Model Based MC and To Evaluations of F82H and Eurofer 97, 3-f) Size and Geometry Effects on the Effective Toughness of Cracked Fusion Structures; 4) Modeling the Multiscale Mechanics of Flow Localization-Ductility Loss in Irradiation Damaged BCC Alloys; and 5) A Universal Relation Between Indentation Hardness and True Stress-Strain Constitutive Behavior. Further details can be found in the cited references or presentations that generally can be accessed on the internet, or provided upon request to the authors. Finally, it is noted that this effort was integrated with our base program in fusion materials, also funded by the DOE OFES.

  5. Inefficient highly eccentric accretion and the low luminosity of stellar tidal disruption events

    E-Print Network [OSTI]

    Svirski, Gilad; Krolik, Julian

    2015-01-01

    Models for tidal disruption events (TDEs) in which a supermassive black hole disrupts a star commonly assume that the highly eccentric streams of bound stellar debris promptly form a circular accretion disk at the pericenter scale. However, the bolometric peak luminosity of most TDE candidates, $\\sim10^{44}\\,\\rm{erg\\,s^{-1}}$, implies that we observe only $\\sim1\\%$ of the energy expected from accretion. Moreover, recent numerical simulations (Shiokawa et al. 2015) have shown that dissipation via hydrodynamical shocks is insufficient to circularize debris orbits on the pericenter scale, and the debris flow retains its initial semi-major axis scale throughout the first $\\sim10$ orbits of the event. Motivated by these numerical results, Piran et al. (2015) suggested that the observed optical TDE emission is powered by shocks at the apocenter between freshly infalling material and earlier-arriving matter. This model explains the small radiated energy, the low temperature, and the large radius implied by the obser...

  6. Electromagnetic Transients Powered by Nuclear Decay in the Tidal Tails of Coalescing Compact Binaries

    E-Print Network [OSTI]

    Roberts, Luke F; Lee, William H; Ramirez-Ruiz, Enrico

    2011-01-01

    The possibility that long tidal tails formed during compact object mergers may power optical transients through the decay of freshly synthesized r-process material is investigated. Precise modeling of the merger dynamics allows for a realistic determination of the thermodynamic conditions in the ejected debris. The results of hydrodynamic and full nuclear network calculations are combined to calculate the resultant r-process abundances and the heating of the material by their decays. The subsequent homologous structure is mapped into a radiative transfer code to synthesize emergent model light curves and determine how their properties (variability and color evolution) depend on the mass ratio and orientation of the merging binary. The radiation emanating from the ejected debris, though less spectacular than a typical supernova, should be observable in transient surveys and we estimate the associated detection rates. The case for (or against) compact object mergers as the progenitors of short gamma-ray bursts ...

  7. Modeling of the performance of weapons MOX fuel in light water reactors

    SciTech Connect (OSTI)

    Alvis, J.; Bellanger, P.; Medvedev, P.G.; Peddicord, K.L.; Gellene, G.I.

    1999-05-01

    Both the Russian Federation and the US are pursing mixed uranium-plutonium oxide (MOX) fuel in light water reactors (LWRs) for the disposition of excess plutonium from disassembled nuclear warheads. Fuel performance models are used which describe the behavior of MOX fuel during irradiation under typical power reactor conditions. The objective of this project is to perform the analysis of the thermal, mechanical, and chemical behavior of weapons MOX fuel pins under LWR conditions. If fuel performance analysis indicates potential questions, it then becomes imperative to assess the fuel pin design and the proposed operating strategies to reduce the probability of clad failure and the associated release of radioactive fission products into the primary coolant system. Applying the updated code to anticipated fuel and reactor designs, which would be used for weapons MOX fuel in the US, and analyzing the performance of the WWER-100 fuel for Russian weapons plutonium disposition are addressed in this report. The COMETHE code was found to do an excellent job in predicting fuel central temperatures. Also, despite minor predicted differences in thermo-mechanical behavior of MOX and UO{sub 2} fuels, the preliminary estimate indicated that, during normal reactor operations, these deviations remained within limits foreseen by fuel pin design.

  8. Advanced Pellet Cladding Interaction Modeling Using the US DOE CASL Fuel Performance Code: Peregrine

    SciTech Connect (OSTI)

    Jason Hales; Various

    2014-06-01

    The US DOE’s Consortium for Advanced Simulation of LWRs (CASL) program has undertaken an effort to enhance and develop modeling and simulation tools for a virtual reactor application, including high fidelity neutronics, fluid flow/thermal hydraulics, and fuel and material behavior. The fuel performance analysis efforts aim to provide 3-dimensional capabilities for single and multiple rods to assess safety margins and the impact of plant operation and fuel rod design on the fuel thermomechanical- chemical behavior, including Pellet-Cladding Interaction (PCI) failures and CRUD-Induced Localized Corrosion (CILC) failures in PWRs. [1-3] The CASL fuel performance code, Peregrine, is an engineering scale code that is built upon the MOOSE/ELK/FOX computational FEM framework, which is also common to the fuel modeling framework, BISON [4,5]. Peregrine uses both 2-D and 3-D geometric fuel rod representations and contains a materials properties and fuel behavior model library for the UO2 and Zircaloy system common to PWR fuel derived from both open literature sources and the FALCON code [6]. The primary purpose of Peregrine is to accurately calculate the thermal, mechanical, and chemical processes active throughout a single fuel rod during operation in a reactor, for both steady state and off-normal conditions.

  9. Foundation Heat Exchanger Final Report: Demonstration, Measured Performance, and Validated Model and Design Tool

    SciTech Connect (OSTI)

    Hughes, Patrick [ORNL; Im, Piljae [ORNL

    2012-01-01

    Geothermal heat pumps, sometimes called ground-source heat pumps (GSHPs), have been proven capable of significantly reducing energy use and peak demand in buildings. Conventional equipment for controlling the temperature and humidity of a building, or supplying hot water and fresh outdoor air, must exchange energy (or heat) with the building's outdoor environment. Equipment using the ground as a heat source and heat sink consumes less non-renewable energy (electricity and fossil fuels) because the earth is cooler than outdoor air in summer and warmer in winter. The most important barrier to rapid growth of the GSHP industry is high first cost of GSHP systems to consumers. The most common GSHP system utilizes a closed-loop ground heat exchanger. This type of GSHP system can be used almost anywhere. There is reason to believe that reducing the cost of closed-loop systems is the strategy that would achieve the greatest energy savings with GSHP technology. The cost premium of closed-loop GSHP systems over conventional space conditioning and water heating systems is primarily associated with drilling boreholes or excavating trenches, installing vertical or horizontal ground heat exchangers, and backfilling the excavations. This project investigates reducing the cost of horizontal closed-loop ground heat exchangers by installing them in the construction excavations, augmented when necessary with additional trenches. This approach applies only to new construction of residential and light commercial buildings or additions to such buildings. In the business-as-usual scenario, construction excavations are not used for the horizontal ground heat exchanger (HGHX); instead the HGHX is installed entirely in trenches dug specifically for that purpose. The potential cost savings comes from using the construction excavations for the installation of ground heat exchangers, thereby minimizing the need and expense of digging additional trenches. The term foundation heat exchanger (FHX) has been coined to refer exclusively to ground heat exchangers installed in the overcut around the basement walls. The primary technical challenge undertaken by this project was the development and validation of energy performance models and design tools for FHX. In terms of performance modeling and design, ground heat exchangers in other construction excavations (e.g., utility trenches) are no different from conventional HGHX, and models and design tools for HGHX already exist. This project successfully developed and validated energy performance models and design tools so that FHX or hybrid FHX/HGHX systems can be engineered with confidence, enabling this technology to be applied in residential and light commercial buildings. The validated energy performance model also addresses and solves another problem, the longstanding inadequacy in the way ground-building thermal interaction is represented in building energy models, whether or not there is a ground heat exchanger nearby. Two side-by-side, three-level, unoccupied research houses with walkout basements, identical 3,700 ft{sup 2} floor plans, and hybrid FHX/HGHX systems were constructed to provide validation data sets for the energy performance model and design tool. The envelopes of both houses are very energy efficient and airtight, and the HERS ratings of the homes are 44 and 45 respectively. Both houses are mechanically ventilated with energy recovery ventilators, with space conditioning provided by water-to-air heat pumps with 2 ton nominal capacities. Separate water-to-water heat pumps with 1.5 ton nominal capacities were used for water heating. In these unoccupied research houses, human impact on energy use (hot water draw, etc.) is simulated to match the national average. At House 1 the hybrid FHX/HGHX system was installed in 300 linear feet of excavation, and 60% of that was construction excavation (needed to construct the home). At House 2 the hybrid FHX/HGHX system was installed in 360 feet of excavation, 50% of which was construction excavation. There are six pipes in all excavations (three par

  10. The effect of simplifying the building description on the numerical modeling of its thermal performance

    SciTech Connect (OSTI)

    Stetiu, C.

    1993-07-01

    A thermal building simulation program is a numerical model that calculates the response of the building envelopes to weather and human activity, simulates dynamic heating and cooling loads, and heating and cooling distribution systems, and models building equipment operation. The scope of the research is to supply the users of such programs with information about the dangers and benefits of simplifying the input to their models. The Introduction describes the advantages of modeling the heat transfer mechanisms in a building. The programs that perform this type of modeling have, however, limitations. The user is therefore often put in the situation of simplifying the floor plans of the building under study, but not being able to check the effects that this approximation introduces in the results of the simulation. Chapter 1 is a description of methods. It also introduces the floor plans for the office building under study and the ``reasonable`` floor plans simplifications. Chapter 2 presents DOE-2, the thermal building simulation program used in the sensitivity study. The evaluation of the accuracy of the DOE-2 program itself is also presented. Chapter 3 contains the sensitivity study. The complicated nature of the process of interpreting the temperature profile inside a space leads to the necessity of defining different building modes. The study compares the results from the model of the detailed building description with the results from the models of the same building having simplified floor plans. The conclusion is reached that a study of the effects of simplifying the floor plans of a building is important mainly for defining the cases in which this approximation is acceptable. Different results are obtained for different air conditioning/load regimes of the building. 9 refs., 24 figs.

  11. Modeling and Simulation of HVAC Faulty Operations and Performance Degradation due to Maintenance Issues

    SciTech Connect (OSTI)

    Wang, Liping; Hong, Tianzhen

    2013-01-01

    Almost half of the total energy used in the U.S. buildings is consumed by heating, ventilation and air conditionings (HVAC) according to EIA statistics. Among various driving factors to energy performance of building, operations and maintenance play a significant role. Many researches have been done to look at design efficiencies and operational controls for improving energy performance of buildings, but very few study the impacts of HVAC systems maintenance. Different practices of HVAC system maintenance can result in substantial differences in building energy use. If a piece of HVAC equipment is not well maintained, its performance will degrade. If sensors used for control purpose are not calibrated, not only building energy usage could be dramatically increased, but also mechanical systems may not be able to satisfy indoor thermal comfort. Properly maintained HVAC systems can operate efficiently, improve occupant comfort, and prolong equipment service life. In the paper, maintenance practices for HVAC systems are presented based on literature reviews and discussions with HVAC engineers, building operators, facility managers, and commissioning agents. We categorize the maintenance practices into three levels depending on the maintenance effort and coverage: 1) proactive, performance-monitored maintenance; 2) preventive, scheduled maintenance; and 3) reactive, unplanned or no maintenance. A sampled list of maintenance issues, including cooling tower fouling, boiler/chiller fouling, refrigerant over or under charge, temperature sensor offset, outdoor air damper leakage, outdoor air screen blockage, outdoor air damper stuck at fully open position, and dirty filters are investigated in this study using field survey data and detailed simulation models. The energy impacts of both individual maintenance issue and combined scenarios for an office building with central VAV systems and central plant were evaluated by EnergyPlus simulations using three approaches: 1) direct modeling with EnergyPlus, 2) using the energy management system feature of EnergyPlus, and 3) modifying EnergyPlus source code. The results demonstrated the importance of maintenance for HVAC systems on energy performance of buildings. The research is intended to provide a guideline to help practitioners and building operators to gain the knowledge of maintaining HVAC systems in efficient operations, and prioritize HVAC maintenance work plan. The paper also discusses challenges of modeling building maintenance issues using energy simulation programs.

  12. Renewable Power Options for Electrical Generation on Kaua'i: Economics and Performance Modeling

    SciTech Connect (OSTI)

    Burman, K.; Keller, J.; Kroposki, B.; Lilienthal, P.; Slaughter, R.; Glassmire, J.

    2011-11-01

    The Hawaii Clean Energy Initiative (HCEI) is working with a team led by the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to assess the economic and technical feasibility of increasing the contribution of renewable energy in Hawaii. This part of the HCEI project focuses on working with Kaua'i Island Utility Cooperative (KIUC) to understand how to integrate higher levels of renewable energy into the electric power system of the island of Kaua'i. NREL partnered with KIUC to perform an economic and technical analysis and discussed how to model PV inverters in the electrical grid.

  13. On the tidal radius of satellites on prograde and retrograde orbits

    E-Print Network [OSTI]

    Gajda, Grzegorz

    2015-01-01

    A tidal radius is a distance from a satellite orbiting in a host potential beyond which its material is stripped by the tidal force. We derive a revised expression for the tidal radius of a rotating satellite which properly takes into account the possibility of prograde and retrograde orbits of stars. Besides the eccentricity of the satellite orbit, the tidal radius depends also on the ratio of the satellite internal angular velocity to the orbital angular velocity. We compare our formula to the results of two $N$-body simulations of dwarf galaxies orbiting a Milky Way-like host on a prograde and retrograde orbit. The tidal radius for the retrograde case is larger than for the prograde. We introduce a kinematic radius separating stars still orbiting the dwarf galaxy from those already stripped and following the potential of the host galaxy. We find that the tidal radius matches very well the kinematic radius.

  14. Microscopic unitary description of tidal excitations in high-energy string-brane collisions

    E-Print Network [OSTI]

    Giuseppe D'Appollonio; Paolo Di Vecchia; Rodolfo Russo; Gabriele Veneziano

    2013-11-15

    The eikonal operator was originally introduced to describe the effect of tidal excitations on higher-genus elastic string amplitudes at high energy. In this paper we provide a precise interpretation for this operator through the explicit tree-level calculation of generic inelastic transitions between closed strings as they scatter off a stack of parallel Dp-branes. We perform this analysis both in the light-cone gauge, using the Green-Schwarz vertex, and in the covariant formalism, using the Reggeon vertex operator. We also present a detailed discussion of the high energy behaviour of the covariant string amplitudes, showing how to take into account the energy factors that enhance the contribution of the longitudinally polarized massive states in a simple way.

  15. Microscopic unitary description of tidal excitations in high-energy string-brane collisions

    E-Print Network [OSTI]

    D'Appollonio, Giuseppe; Vecchia, Paolo; Veneziano, Gabriele

    2013-01-01

    The eikonal operator was originally introduced to describe the effect of tidal excitations on higher-genus elastic string amplitudes at high energy. In this paper we provide a precise interpretation for this operator through the explicit tree-level calculation of generic inelastic transitions between closed strings as they scatter off a stack of parallel Dp-branes. We perform this analysis both in the light-cone gauge, using the Green-Schwarz vertex, and in the covariant formalism, using the Reggeon vertex operator. We also present a detailed discussion of the high energy behaviour of the covariant string amplitudes, showing how to take into account the energy factors that enhance the contribution of the longitudinally polarized massive states in a simple way.

  16. PORFLOW MODELING FOR A PRELIMINARY ASSESSMENT OF THE PERFORMANCE OF NEW SALTSTONE DISPOSAL UNIT DESIGNS

    SciTech Connect (OSTI)

    Smith, F.

    2012-08-06

    At the request of Savannah River Remediation (SRR), SRNL has analyzed the expected performance obtained from using seven 32 million gallon Saltstone Disposal Units (SDUs) in the Z-Area Saltstone Disposal Facility (SDF) to store future saltstone grout. The analysis was based on preliminary SDU final design specifications. The analysis used PORFLOW modeling to calculate the release of 20 radionuclides from an SDU and transport of the radionuclides and daughters through the vadose zone. Results from this vadose zone analysis were combined with previously calculated releases from existing saltstone vaults and FDCs and a second PORFLOW model run to calculate aquifer transport to assessment points located along a boundary 100 m from the nearest edge of the SDF sources. Peak concentrations within 12 sectors spaced along the 100 m boundary were determined over a period of evaluation extending 20,000 years after SDF closure cap placement. These peak concentrations were provided to SRR to use as input for dose calculations.

  17. Performance of corrosion inhibiting admixtures for structural concrete -- assessment methods and predictive modeling

    SciTech Connect (OSTI)

    Yunovich, M.; Thompson, N.G.

    1998-12-31

    During the past fifteen years corrosion inhibiting admixtures (CIAs) have become increasingly popular for protection of reinforced components of highway bridges and other structures from damage induced by chlorides. However, there remains considerable debate about the benefits of CIAs in concrete. A variety of testing methods to assess the performance of CIA have been reported in the literature, ranging from tests in simulated pore solutions to long-term exposures of concrete slabs. The paper reviews the published techniques and recommends the methods which would make up a comprehensive CIA effectiveness testing program. The results of this set of tests would provide the data which can be used to rank the presently commercially available CIA and future candidate formulations utilizing a proposed predictive model. The model is based on relatively short-term laboratory testing and considers several phases of a service life of a structure (corrosion initiation, corrosion propagation without damage, and damage to the structure).

  18. Possible future projection of Indian Summer Monsoon Rainfall (ISMR) with the evaluation of model performance in Coupled

    E-Print Network [OSTI]

    Phipps, Steven J.

    Possible future projection of Indian Summer Monsoon Rainfall (ISMR) with the evaluation of model assessment of future projected rainfall will be important for policy framework. Evaluation of models performance in Coupled Model Inter-comparison Project Phase 5 (CMIP5) P. Parth Sarthi , Soumik Ghosh, Praveen

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

    E-Print Network [OSTI]

    Durham, Donald L

    1967-01-01

    LIST OF FIGURES Chapter TABLE OF CONTENTS Page vi vii IV INTRODUCTION A. Statement of Problem B. Literature Review 1. Tidal Current Theory 2. Tidal Current Observations INSTRUMENTATION AND DATA COLLECTION A. Selection and Modification... of Equipment B. September 1965 Survey DATA ANALYSIS AND RESULTS A. The Surface Tide 1. General 2. Gulf of Mexico B. Current Components C. Spectral Analysis D. Harmonic Analysis E. Tidal Ellipse F, Temperature CONCLUSIONS 1 1 2 2 11 15 15 21...

  20. Summary Results for Brine Migration Modeling Performed by LANL LBNL and SNL for the UFD Program.

    SciTech Connect (OSTI)

    Kuhlman, Kristopher L

    2014-09-01

    This report summarizes laboratory and field observations and numerical modeling related to coupled processes involving brine and vapor migration in geologic salt, focusing on recent developments and studies conducted at Sandia, Los Alamos, and Berkeley National Laboratories. Interest into the disposal of heat-generating waste in salt has led to interest into water distribution and migration in both run-of-mine crushed and intact geologic salt. Ideally a fully coupled thermal-hydraulic-mechanical-chemical simulation is performed using numerical models with validated constitutive models and parameters. When mechanical coupling is not available, mechanical effects are prescribed in hydraulic models as source, boundary, or initial conditions. This report presents material associated with developing appropriate initial conditions for a non-mechanical hydrologic simulation of brine migration in salt. Due to the strong coupling between the mechanical and hydrologic problems, the initial saturation will be low for the excavation disturbed zone surrounding the excavation. Although most of the material in this report is not new, the author hopes it is presented in a format making it useful to other salt researchers.

  1. Coupling a transient solvent extraction module with the separations and safeguards performance model.

    SciTech Connect (OSTI)

    DePaoli, David W.; Birdwell, Joseph F.; Gauld, Ian C.; Cipiti, Benjamin B.; de Almeida, Valmor F.

    2009-10-01

    A number of codes have been developed in the past for safeguards analysis, but many are dated, and no single code is able to cover all aspects of materials accountancy, process monitoring, and diversion scenario analysis. The purpose of this work was to integrate a transient solvent extraction simulation module developed at Oak Ridge National Laboratory, with the Separations and Safeguards Performance Model (SSPM), developed at Sandia National Laboratory, as a first step toward creating a more versatile design and evaluation tool. The SSPM was designed for materials accountancy and process monitoring analyses, but previous versions of the code have included limited detail on the chemical processes, including chemical separations. The transient solvent extraction model is based on the ORNL SEPHIS code approach to consider solute build up in a bank of contactors in the PUREX process. Combined, these capabilities yield a more robust transient separations and safeguards model for evaluating safeguards system design. This coupling and initial results are presented. In addition, some observations toward further enhancement of separations and safeguards modeling based on this effort are provided, including: items to be addressed in integrating legacy codes, additional improvements needed for a fully functional solvent extraction module, and recommendations for future integration of other chemical process modules.

  2. Mechanisms generating modification of benthos following tidal flat invasion by a Spartina hybrid

    E-Print Network [OSTI]

    Neira, C; Grosholz, E D; Levin, L A; Blake, R

    2006-01-01

    1997. Kinetics of tidal resuspension of microbiota: testingare susceptible to resuspension following bio- turbation (in barnacle recruitment and resuspension of adult benthic

  3. MECHANISMS GENERATING MODIFICATION OF BENTHOS FOLLOWING TIDAL FLAT INVASION BY A SPARTINA HYBRID

    E-Print Network [OSTI]

    Neira, Carlos; Grosholz, Edwin D; Levin, Lisa A; Blake, Rachael

    2006-01-01

    1997. Kinetics of tidal resuspension of microbiota: testingare susceptible to resuspension following bio- turbation (in barnacle recruitment and resuspension of adult benthic

  4. 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

    2012-02-01

    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.

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

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

    Office What are the key documents? Mapping and Assessment of the United States Ocean Wave Energy Resource pdf here Assessment of Energy Production Potential from Tidal Streams...

  6. Performance Task using Video Analysis and Modelling to promote K12 eight practices of science

    E-Print Network [OSTI]

    Wee, Loo Kang

    2015-01-01

    We will share on the use of Tracker as a pedagogical tool in the effective learning and teaching of physics performance tasks taking root in some Singapore Grade 9 (Secondary 3) schools. We discuss the pedagogical use of Tracker help students to be like scientists in these 6 to 10 weeks where all Grade 9 students are to conduct a personal video analysis and where appropriate the 8 practices of sciences (1. ask question, 2. use models, 3. Plan and carry out investigation, 4. Analyse and interpret data, 5. Using mathematical and computational thinking, 6. Construct explanations, 7. Discuss from evidence and 8. Communicating information). We will situate our sharing on actual students work and discuss how tracker could be an effective pedagogical tool. Initial research findings suggest that allowing learners conduct performance task using Tracker, a free open source video analysis and modelling tool, guided by the 8 practices of sciences and engineering, could be an innovative and effective way to mentor authent...

  7. Performance Modeling of a Wide Field Ground Layer Adaptive Optics System

    E-Print Network [OSTI]

    D. Andersen; J. Stoesz; S. Morris; M. Lloyd-Hart; D. Crampton; T. Butterley; B. Ellerbroek; L. Jollissaint; N. M. Milton; R. Myers; K. Szeto; A. Tokovinin; J. -P. Veran; R. Wilson

    2006-10-03

    Using five independent analytic and Monte Carlo simulation codes, we have studied the performance of wide field ground layer adaptive optics (GLAO), which can use a single, relatively low order deformable mirror to correct the wavefront errors from the lowest altitude turbulence. GLAO concentrates more light from a point source in a smaller area on the science detector, but unlike traditional adaptive optics, images do not become diffraction-limited. Rather the GLAO point spread function (PSF) has the same functional form as a seeing-limited PSF, and can be characterized by familiar performance metrics such as Full-Width Half-Max (FWHM). The FWHM of a GLAO PSF is reduced by 0.1" or more for optical and near-infrared wavelengths over different atmospheric conditions. For the Cerro Pachon atmospheric model this correction is even greater when the image quality is worst, which effectively eliminates "bad-seeing" nights; the best seeing-limited image quality, available only 20% of the time, can be achieved 60 to 80% of the time with GLAO. This concentration of energy in the PSF will reduce required exposure times and improve the efficiency of an observatory up to 30 to 40%. These performance gains are relatively insensitive to a number of trades including the exact field of view of a wide field GLAO system, the conjugate altitude and actuator density of the deformable mirror, and the number and configuration of the guide stars.

  8. Nuclear Energy Advanced Modeling and Simulation (NEAMS) waste Integrated Performance and Safety Codes (IPSC) : gap analysis for high fidelity and performance assessment code development.

    SciTech Connect (OSTI)

    Lee, Joon H.; Siegel, Malcolm Dean; Arguello, Jose Guadalupe, Jr.; Webb, Stephen Walter; Dewers, Thomas A.; Mariner, Paul E.; Edwards, Harold Carter; Fuller, Timothy J.; Freeze, Geoffrey A.; Jove-Colon, Carlos F.; Wang, Yifeng

    2011-03-01

    This report describes a gap analysis performed in the process of developing the Waste Integrated Performance and Safety Codes (IPSC) in support of the U.S. Department of Energy (DOE) Office of Nuclear Energy Advanced Modeling and Simulation (NEAMS) Campaign. The goal of the Waste IPSC is to develop an integrated suite of computational modeling and simulation capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive waste storage or disposal system. The Waste IPSC will provide this simulation capability (1) for a range of disposal concepts, waste form types, engineered repository designs, and geologic settings, (2) for a range of time scales and distances, (3) with appropriate consideration of the inherent uncertainties, and (4) in accordance with rigorous verification, validation, and software quality requirements. The gap analyses documented in this report were are performed during an initial gap analysis to identify candidate codes and tools to support the development and integration of the Waste IPSC, and during follow-on activities that delved into more detailed assessments of the various codes that were acquired, studied, and tested. The current Waste IPSC strategy is to acquire and integrate the necessary Waste IPSC capabilities wherever feasible, and develop only those capabilities that cannot be acquired or suitably integrated, verified, or validated. The gap analysis indicates that significant capabilities may already exist in the existing THC codes although there is no single code able to fully account for all physical and chemical processes involved in a waste disposal system. Large gaps exist in modeling chemical processes and their couplings with other processes. The coupling of chemical processes with flow transport and mechanical deformation remains challenging. The data for extreme environments (e.g., for elevated temperature and high ionic strength media) that are needed for repository modeling are severely lacking. In addition, most of existing reactive transport codes were developed for non-radioactive contaminants, and they need to be adapted to account for radionuclide decay and in-growth. The accessibility to the source codes is generally limited. Because the problems of interest for the Waste IPSC are likely to result in relatively large computational models, a compact memory-usage footprint and a fast/robust solution procedure will be needed. A robust massively parallel processing (MPP) capability will also be required to provide reasonable turnaround times on the analyses that will be performed with the code. A performance assessment (PA) calculation for a waste disposal system generally requires a large number (hundreds to thousands) of model simulations to quantify the effect of model parameter uncertainties on the predicted repository performance. A set of codes for a PA calculation must be sufficiently robust and fast in terms of code execution. A PA system as a whole must be able to provide multiple alternative models for a specific set of physical/chemical processes, so that the users can choose various levels of modeling complexity based on their modeling needs. This requires PA codes, preferably, to be highly modularized. Most of the existing codes have difficulties meeting these requirements. Based on the gap analysis results, we have made the following recommendations for the code selection and code development for the NEAMS waste IPSC: (1) build fully coupled high-fidelity THCMBR codes using the existing SIERRA codes (e.g., ARIA and ADAGIO) and platform, (2) use DAKOTA to build an enhanced performance assessment system (EPAS), and build a modular code architecture and key code modules for performance assessments. The key chemical calculation modules will be built by expanding the existing CANTERA capabilities as well as by extracting useful components from other existing codes.

  9. Lagrangian analysis of a tidal plume Initial Expansion of the Columbia River Tidal Plume

    E-Print Network [OSTI]

    Jay, David

    numerical model (with five mixing formulations) are tested. Model results are compared to SAR images and vessel radar data to verify that the predicted fron- tal properties are realistic. The models show, and it is important to include the horizontal gradient in F as well as surface slope in the pressure gradient driving

  10. Yardstick and Ex-post Regulation by Norm Model: Empirical Equivalence, Pricing Effect, and Performance in Sweeden

    E-Print Network [OSTI]

    Jamasb, Tooraj; Söderberg, M.

    Contact tooraj.jamasb@econ.cam.ac.uk Publication Financial Support UK Economic and Social Research Council 5 January 2009 Yardstick and Ex-Post Regulation by Norm Model: Empirical Equivalence, Pricing Response, and Firm Performance... . In the regulatory context norm models have been regarded as a means to reduce the information asymmetry between the regulator and the regulated firm. Norm models can be regarded as a bottom-up approach to benchmarking, whereas real firm models of benchmarking...

  11. Model-Driven Dashboards for Business Performance Reporting Pawan Chowdhary, Themis Palpanas, Florian Pinel, Shyh-Kwei Chen, Frederick Y. Wu

    E-Print Network [OSTI]

    Palpanas, Themis

    Model-Driven Dashboards for Business Performance Reporting Pawan Chowdhary, Themis Palpanas, skchen, fywu}@us.ibm.com Abstract Business performance modeling and model-driven business transformation an approach for dashboard development that is model-driven and can be integrated with the business performance

  12. Jets from Tidal Disruptions of Stars by Black Holes

    E-Print Network [OSTI]

    Julian H. Krolik; Tsvi Piran

    2012-02-07

    Tidal disruption of main sequence stars by black holes has generally been thought to lead to a signal dominated by UV emission. If, however, the black hole spins rapidly and the poloidal magnetic field intensity on the black hole horizon is comparable to the inner accretion disk pressure, a powerful jet may form whose luminosity can easily exceed the thermal UV luminosity. When the jet beam points at Earth, its non-thermal luminosity can dominate the emitted spectrum. The thermal and non-thermal components decay differently with time. In particular, the thermal emission should remain roughly constant for a significant time after the period of maximum accretion, beginning to diminish only after a delay, whereas after the peak accretion rate, the non-thermal jet emission decays, but then reaches a plateau. Both transitions are tied to a characteristic timescale $t_{\\rm Edd}$ at which the accretion rate falls below Eddington. Making use of this timescale in a new parameter-inference formalism for tidal disruption events with significant emission from a jet, we analyze the recent flare source Swift J2058. It is consistent with an event in which a main sequence solar-type staris disrupted by a black hole of mass $\\sim 4 \\times 10^7 M_{\\odot}$. The beginning of the flat phase in the non-thermal emission from this source can possibly be seen in the late-time lightcurve. Optical photometry over the first $\\simeq 40$ d of this flare is also consistent with this picture, but is only weakly constraining because the bolometric correction is very uncertain. We suggest that future searches for main sequence tidal disruptions use methods sensitive to jet radiation as well as to thermal UV radiation.

  13. Tidal-Fluvial and Estuarine Processes in the Lower Columbia River: I. Along-channel Water Level Variations, Pacific Ocean to Bonneville Dam

    SciTech Connect (OSTI)

    Jay, D. A.; Leffler, K.; Diefenderfer, Heida L.; Borde, Amy B.

    2014-06-07

    This two-part paper provides comprehensive time and frequency domain analyses and models of along-channel water level variations in the 234km-long Lower Columbia River and Estuary (LCRE) and documents the response of floodplain wetlands thereto. In Part I, power spectra, continuous wavelet transforms, and harmonic analyses are used to understand the influences of tides, river flow, upwelling and downwelling, and hydropower operations ("power-peaking") on the water level regime. Estuarine water levels are influenced primarily by astronomical tides and coastal processes, and secondarily by river flow. The importance of coastal and tidal influences decreases in the landward direction, and water levels are increasingly controlled by river flow variations at periods from ?1day to years. Water level records are only slightly non-stationary near the ocean, but become increasingly irregular upriver. Although astronomically forced tidal constituents decrease above the estuary, tidal fortnightly and overtide variations increase for 80-200km landward, both relative to major tidal constituents and in absolute terms.

  14. TRISO Fuel Performance: Modeling, Integration into Mainstream Design Studies, and Application to a Thorium-fueled Fusion-Fission Hybrid Blanket

    E-Print Network [OSTI]

    Powers, Jeffrey

    2011-01-01

    Quantification in Fuel Performance Modeling . . . . . . .3.4 Integration with Fuel Performance Calculations ivmicroscopic image of a TRISO fuel particle cracked open to

  15. Literature Review and Assessment of Plant and Animal Transfer Factors Used in Performance Assessment Modeling

    SciTech Connect (OSTI)

    Robertson, David E.; Cataldo, Dominic A.; Napier, Bruce A.; Krupka, Kenneth M.; Sasser, Lyle B.

    2003-07-20

    A literature review and assessment was conducted by Pacific Northwest National Laboratory (PNNL) to update information on plant and animal radionuclide transfer factors used in performance-assessment modeling. A group of 15 radionuclides was included in this review and assessment. The review is composed of four main sections, not including the Introduction. Section 2.0 provides a review of the critically important issue of physicochemical speciation and geochemistry of the radionuclides in natural soil-water systems as it relates to the bioavailability of the radionuclides. Section 3.0 provides an updated review of the parameters of importance in the uptake of radionuclides by plants, including root uptake via the soil-groundwater system and foliar uptake due to overhead irrigation. Section 3.0 also provides a compilation of concentration ratios (CRs) for soil-to-plant uptake for the 15 selected radionuclides. Section 4.0 provides an updated review on radionuclide uptake data for animal products related to absorption, homeostatic control, approach to equilibration, chemical and physical form, diet, and age. Compiled transfer coefficients are provided for cow’s milk, sheep’s milk, goat’s milk, beef, goat meat, pork, poultry, and eggs. Section 5.0 discusses the use of transfer coefficients in soil, plant, and animal modeling using regulatory models for evaluating radioactive waste disposal or decommissioned sites. Each section makes specific suggestions for future research in its area.

  16. Benchmarking of the MIT High Temperature Gas-cooled Reactor TRISO-coated particle fuel performance model

    E-Print Network [OSTI]

    Stawicki, Michael A

    2006-01-01

    MIT has developed a Coated Particle Fuel Performance Model to study the behavior of TRISO nuclear fuels. The code, TIMCOAT, is designed to assess the mechanical and chemical condition of populations of coated particles and ...

  17. Modeling within-word and cross-word pronunciation variation to improve the performance of a Dutch CSR. 

    E-Print Network [OSTI]

    Kessens, Judith M; Wester, Mirjam; Strik, Helmer

    1999-01-01

    This paper describes how the performance of a continuous speech recognizer for Dutch has been improved by modeling within-word and cross-word pronunciation variation. Within-word variants were automatically generated by ...

  18. MHK Projects/Rockaway 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 Home Page on QA:QAsource History View NewTexas:Montezuma,Information MHKMHK5 < MHKKembla < MHK Projects JumpRockaway Tidal

  19. The Wash Tidal Barrier 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 Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoop Inc JumpHeterInformation Policy andInstitute JumpWash Tidal Barrier

  20. List of Tidal Energy Incentives | 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 Home Page on QA:QA J-E-1 SECTION J APPENDIXsource History ViewInformationWindsCompressedList of RefuelingRoomList ofSolarTidal

  1. MHK Projects/Avalon 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 Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 Jump to:Projects/Alaska 31 <Avalon Tidal < MHK

  2. 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 Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 Jump to:Projects/Alaska 31 <Avalon Tidal <BW2

  3. 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 Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 Jump to:Projects/Alaska 31BondurantCETO3May Tidal

  4. MHK Projects/Killisnoo 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 Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 JumpCoos Bay OPTHalf MoonKillisnoo Tidal Energy <

  5. MHK Projects/Kingsbridge 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 Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 JumpCoos Bay OPTHalf MoonKillisnoo Tidal Energy

  6. MHK Projects/Margate 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 Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 JumpCoos Bay OPTHalf| Open EnergyMaineMargate Tidal

  7. MHK Projects/Maurice River 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 Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 JumpCoos Bay OPTHalf| OpenMaurice River Tidal <

  8. MHK Projects/Salem 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 Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 JumpCoos BayOysterReliance LightSalem Tidal Energy

  9. MHK Technologies/Sabella subsea tidal turbine | 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 Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050Enermar <OMIS D E < MHKSPERBOY <subsea tidal

  10. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation CurrentHenry Bellamy, Ph.D.FoodHydropower, Wave and Tidal » Technology

  11. TRISO-Fuel Element Performance Modeling for the Hybrid LIFE Engine with Pu Fuel Blanket

    SciTech Connect (OSTI)

    DeMange, P; Marian, J; Caro, M; Caro, A

    2010-02-18

    A TRISO-coated fuel thermo-mechanical performance study is performed for the hybrid LIFE engine to test the viability of TRISO particles to achieve ultra-high burnup of a weapons-grade Pu blanket. Our methodology includes full elastic anisotropy, time and temperature varying material properties for all TRISO layers, and a procedure to remap the elastic solutions in order to achieve fast fluences up to 30 x 10{sup 25} n {center_dot} m{sup -2} (E > 0.18 MeV). In order to model fast fluences in the range of {approx} 7 {approx} 30 x 10{sup 25} n {center_dot} m{sup -2}, for which no data exist, careful scalings and extrapolations of the known TRISO material properties are carried out under a number of potential scenarios. A number of findings can be extracted from our study. First, failure of the internal pyrolytic carbon (PyC) layer occurs within the first two months of operation. Then, the particles behave as BISO-coated particles, with the internal pressure being withstood directly by the SiC layer. Later, after 1.6 years, the remaining PyC crumbles due to void swelling and the fuel particle becomes a single-SiC-layer particle. Unrestrained by the PyC layers, and at the temperatures and fluences in the LIFE engine, the SiC layer maintains reasonably-low tensile stresses until the end-of-life. Second, the PyC creep constant, K, has a striking influence on the fuel performance of TRISO-coated particles, whose stresses scale almost inversely proportional to K. Obtaining more reliable measurements, especially at higher fluences, is an imperative for the fidelity of our models. Finally, varying the geometry of the TRISO-coated fuel particles results in little differences in the scope of fuel performance. The mechanical integrity of 2-cm graphite pebbles that act as fuel matrix has also been studied and it is concluded that they can reliable serve the entire LIFE burnup cycle without failure.

  12. Modification and Validation of a Universal Thermodynamic Chiller Model Used to Evaluate the Performance of Water-Cooled Centrifugal Chillers 

    E-Print Network [OSTI]

    Figueroa, I. E.; Cathey, M.; Medina, M. A.; Nutter, D. W.

    1998-01-01

    at the condenser. The model was developed as a tool for analyzing chiller performance. It was designed to predict the coefficient of performance (COP) and the total electrical energy consumed by the compressor. The input parameters included time-series values...

  13. Determination of Electrochemical Performance and Thermo-Mechanical-Chemical Stability of SOFCs from Defect Modeling

    SciTech Connect (OSTI)

    Eric Wachsman; Keith L. Duncan

    2006-09-30

    This research was focused on two distinct but related issues. The first issue concerned using defect modeling to understand the relationship between point defect concentration and the electrochemical, thermo-chemical and mechano-chemical properties of typical solid oxide fuel cell (SOFC) materials. The second concerned developing relationships between the microstructural features of SOFC materials and their electrochemical performance. To understand the role point defects play in ceramics, a coherent analytical framework was used to develop expressions for the dependence of thermal expansion and elastic modulus on point defect concentration in ceramics. These models, collectively termed the continuum-level electrochemical model (CLEM), were validated through fits to experimental data from electrical conductivity, I-V characteristics, elastic modulus and thermo-chemical expansion experiments for (nominally pure) ceria, gadolinia-doped ceria (GDC) and yttria-stabilized zirconia (YSZ) with consistently good fits. The same values for the material constants were used in all of the fits, further validating our approach. As predicted by the continuum-level electrochemical model, the results reveal that the concentration of defects has a significant effect on the physical properties of ceramic materials and related devices. Specifically, for pure ceria and GDC, the elastic modulus decreased while the chemical expansion increased considerably in low partial pressures of oxygen. Conversely, the physical properties of YSZ remained insensitive to changes in oxygen partial pressure within the studied range. Again, the findings concurred exactly with the predictions of our analytical model. Indeed, further analysis of the results suggests that an increase in the point defect content weakens the attractive forces between atoms in fluorite-structured oxides. The reduction treatment effects on the flexural strength and the fracture toughness of pure ceria were also evaluated at room temperature. The results reveal that the flexural strength decreases significantly after heat treatment in very low oxygen partial pressure environments; however, in contrast, fracture toughness is increased by 30-40% when the oxygen partial pressure was decreased to 10{sup -20} to 10{sup -22} atm range. Fractographic studies show that microcracks developed at 800 oC upon hydrogen reduction are responsible for the decreased strength. To understand the role of microstructure on electrochemical performance, electrical impedance spectra from symmetric LSM/YSZ/LSM cells was de-convoluted to obtain the key electrochemical components of electrode performance, namely charge transfer resistance, surface diffusion of reactive species and bulk gas diffusion through the electrode pores. These properties were then related to microstructural features, such as triple-phase boundary length and tortuosity. From these experiments we found that the impedance due to oxygen adsorption obeys a power law with pore surface area, while the impedance due to charge transfer is found to obey a power-law with respect to triple phase boundary length. A model based on kinetic theory explaining the power-law relationships observed was then developed. Finally, during our EIS work on the symmetric LSM/YSZ/LSM cells a technique was developed to improve the quality of high-frequency impedance data and their subsequent de-convolution.

  14. The Use Of Computational Human Performance Modeling As Task Analysis Tool

    SciTech Connect (OSTI)

    Jacuqes Hugo; David Gertman

    2012-07-01

    During a review of the Advanced Test Reactor safety basis at the Idaho National Laboratory, human factors engineers identified ergonomic and human reliability risks involving the inadvertent exposure of a fuel element to the air during manual fuel movement and inspection in the canal. There were clear indications that these risks increased the probability of human error and possible severe physical outcomes to the operator. In response to this concern, a detailed study was conducted to determine the probability of the inadvertent exposure of a fuel element. Due to practical and safety constraints, the task network analysis technique was employed to study the work procedures at the canal. Discrete-event simulation software was used to model the entire procedure as well as the salient physical attributes of the task environment, such as distances walked, the effect of dropped tools, the effect of hazardous body postures, and physical exertion due to strenuous tool handling. The model also allowed analysis of the effect of cognitive processes such as visual perception demands, auditory information and verbal communication. The model made it possible to obtain reliable predictions of operator performance and workload estimates. It was also found that operator workload as well as the probability of human error in the fuel inspection and transfer task were influenced by the concurrent nature of certain phases of the task and the associated demand on cognitive and physical resources. More importantly, it was possible to determine with reasonable accuracy the stages as well as physical locations in the fuel handling task where operators would be most at risk of losing their balance and falling into the canal. The model also provided sufficient information for a human reliability analysis that indicated that the postulated fuel exposure accident was less than credible.

  15. Performance and cost models for the direct sulfur recovery process. Task 1 Topical report, Volume 3

    SciTech Connect (OSTI)

    Frey, H.C. [North Carolina State Univ., Raleigh, NC (United States); Williams, R.B. [Carneigie Mellon Univ., Pittsburgh, PA (United States)

    1995-09-01

    The purpose of this project is to develop performance and cost models of the Direct Sulfur Recovery Process (DSRP). The DSRP is an emerging technology for sulfur recovery from advanced power generation technologies such as Integrated Gasification Combined Cycle (IGCC) systems. In IGCC systems, sulfur present in the coal is captured by gas cleanup technologies to avoid creating emissions of sulfur dioxide to the atmosphere. The sulfur that is separated from the coal gas stream must be collected. Leading options for dealing with the sulfur include byproduct recovery as either sulfur or sulfuric acid. Sulfur is a preferred byproduct, because it is easier to handle and therefore does not depend as strongly upon the location of potential customers as is the case for sulfuric acid. This report describes the need for new sulfur recovery technologies.

  16. Low Cost Carbon Fibre: Applications, Performance and Cost Models - Chapter 17

    SciTech Connect (OSTI)

    Warren, Charles David; Wheatley, Dr. Alan; Das, Sujit

    2014-01-01

    Weight saving in automotive applications has a major bearing on fuel economy. It is generally accepted that, typically, a 10% weight reduction in an automobile will lead to a 6-8% improvement in fuel economy. In this respect, carbon fibre composites are extremely attractive in their ability to provide superlative mechanical performance per unit weight. That is why they are specified for high-end uses such as Formula 1 racing cars and the latest aircraft (e.g. Boeing 787, Airbus A350 and A380), where they comprise over 50% by weight of the structure However, carbon fibres are expensive and this renders their composites similarly expensive. Research has been carried out at Oak Ridge National Laboratories (ORNL), Tennessee, USA for over a decade with the aim of reducing the cost of carbon fibre such that it becomes a cost-effective option for the automotive industry. Aspects of this research relating to the development of low cost carbon fibre have been reported in Chapter 3 of this publication. In this chapter, the practical industrial applications of low-cost carbon fibre are presented, together with considerations of the performance and cost models which underpin the work.

  17. A SIMULATION MODEL FOR THE PERFORMANCE ANALYSIS OF ROOF POND SYSTEMS FOR HEATING AND COOLING

    E-Print Network [OSTI]

    Tavana, Medhi

    2011-01-01

    on Heating Performance of Roof Pond XSL803-6664 Fig. 4.on Heating Performance of Roof Pond Phoenix, Arizona Auguston Cooling Performance of Roof Pond HOur of the doy (solar

  18. RED CLUMP STARS IN THE SAGITTARIUS TIDAL STREAMS

    SciTech Connect (OSTI)

    Carrell, Kenneth; Chen Yuqin; Wilhelm, Ronald

    2012-07-15

    We have probed a section (l {approx} 150, b {approx} -60) of the trailing tidal arm of the Sagittarius dwarf spheroidal galaxy by identifying a sample of Red Clump (RC) stream stars. RC stars are not generally found in the halo field, but are found in significant numbers in both the Sagittarius galaxy and its tidal streams, making them excellent probes of stream characteristics. Our target sample was selected using photometric data from the Sloan Digital Sky Survey, Data Release 6, which was constrained in color to match the Sagittarius RC stars. Spectroscopic observations of the target stars were conducted at Kitt Peak National Observatory using the WIYN telescope. The resulting spectroscopic sample is magnitude limited and contains both main-sequence disk stars and evolved RC stars. We have developed a method to systematically separate these two stellar classes using kinematic information and a Bayesian approach for surface gravity determination. The resulting RC sample allows us to determine an absolute stellar density of {rho} = 2.7 {+-} 0.5 RC stars kpc{sup -3} at this location in the stream. Future measurements of stellar densities for a variety of populations and at various locations along the streams will lead to a much improved understanding of the original nature of the Sagittarius galaxy and the physical processes controlling its disruption and subsequent stream generation.

  19. Relativistic effects on tidal disruption kicks of solitary stars

    E-Print Network [OSTI]

    Gafton, Emanuel; Guillochon, James; Korobkin, Oleg; Rosswog, Stephan

    2015-01-01

    Solitary stars that wander too close to their galactic centres can become tidally disrupted, if the tidal forces due to the supermassive black hole (SMBH) residing there overcome the self-gravity of the star. If the star is only partially disrupted, so that a fraction survives as a self-bound object, this remaining core will experience a net gain in specific orbital energy, which translates into a velocity "kick" of up to $\\sim 10^3$ km/s. In this paper, we present the result of smoothed particle hydrodynamics (SPH) simulations of such partial disruptions, and analyse the velocity kick imparted on the surviving core. We compare $\\gamma$ = 5/3 and $\\gamma$ = 4/3 polytropes disrupted in both a Newtonian potential, and a generalized potential that reproduces most relativistic effects around a Schwarzschild black hole either exactly or to excellent precision. For the Newtonian case, we confirm the results of previous studies that the kick velocity of the surviving core is virtually independent of the ratio of the...

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

    E-Print Network [OSTI]

    Jason Harris

    2006-12-04

    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.

  1. Preliminary performance assessment for the Waste Isolation Pilot Plant, December 1992. Volume 3, Model parameters: Sandia WIPP Project

    SciTech Connect (OSTI)

    Not Available

    1992-12-29

    This volume documents model parameters chosen as of July 1992 that were used by the Performance Assessment Department of Sandia National Laboratories in its 1992 preliminary performance assessment of the Waste Isolation Pilot Plant (WIPP). Ranges and distributions for about 300 modeling parameters in the current secondary data base are presented in tables for the geologic and engineered barriers, global materials (e.g., fluid properties), and agents that act upon the WIPP disposal system such as climate variability and human-intrusion boreholes. The 49 parameters sampled in the 1992 Preliminary Performance Assessment are given special emphasis with tables and graphics that provide insight and sources of data for each parameter.

  2. HAWAIIAN OCEAN MIXING EXPERIMENT (HOME): FARFIELD PROGRAM HAWAIIAN TIDAL ENERGY BUDGET

    E-Print Network [OSTI]

    Dushaw, Brian

    HAWAIIAN OCEAN MIXING EXPERIMENT (HOME): FARFIELD PROGRAM HAWAIIAN TIDAL ENERGY BUDGET Principal). This tidal energy budget will determine limits on the energy dissipated in the nearfield of the Hawaiian and ocean acoustic tomography have brought a new dimension to the subject. We propose to measure the energy

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

    E-Print Network [OSTI]

    Klymak, Jody M.

    JULY 2005 1 An estimate of tidal energy lost to turbulence at the Hawaiian Ridge JODY M. KLYMAK1 of the ridge, giving an estimate of 3±1.5 GW of tidal energy lost to turbulence dissipation within 60 km relation- ship between the energy in the semi-diurnal internal tide (E) and the depth

  4. ORNL/TM-2012/301 Experimental Test Plan DOE Tidal

    E-Print Network [OSTI]

    Siefert, Chris

    ORNL/TM-2012/301 Experimental Test Plan ­ DOE Tidal And River Reference Turbines August 2012 Test Plan ­ DOE Tidal and River Reference Turbines Vincent S. Neary1 Craig Hill2 Leonardo P. Chamorro 2 16, 2012 Prepared for: Wind and Water Power Technologies Program Office of Energy Efficiency

  5. time scale observed in some close binary systems (19), and tidal dissipation (20)

    E-Print Network [OSTI]

    Stanley, H. Eugene

    time scale observed in some close binary systems (19), and tidal dissipation (20) may also cause). At this stage, the core of star A undergoes collapse, and the residual nuclear fuel is ignited to power aware that both tidal and general relativistic ef- fects will be important in this system

  6. Post Doctoral (OR Research Engineer) fellowship Distributed Control of a Tidal Farm

    E-Print Network [OSTI]

    Condat, Laurent

    Post Doctoral (OR Research Engineer) fellowship Distributed Control of a Tidal Farm Context on con- trol systems and power systems) and ALSTOM-ocean (world- wide leader in turbines construction and operating a tidal farm of 30-200 MW. Successful applicants will work at GIPSA-lab (Grenoble) (http

  7. Can Earth's rotation and tidal despinning drive plate tectonics? Federica Riguzzi a,c,

    E-Print Network [OSTI]

    Can Earth's rotation and tidal despinning drive plate tectonics? Federica Riguzzi a,c, , Giuliano January 2009 Accepted 10 June 2009 Available online xxxx Keywords: Plate tectonics Earth's rotation Tidal despinning Earth's energy budget We re-evaluate the possibility that Earth's rotation contributes to plate

  8. Vibrio litoralis sp. nov., isolated from a Yellow Sea tidal flat in Korea

    E-Print Network [OSTI]

    Bae, Jin-Woo

    Vibrio litoralis sp. nov., isolated from a Yellow Sea tidal flat in Korea Young-Do Nam,1,2 Ho-negative, facultatively anaerobic bacterial strains, MANO22DT and MANO22P, were isolated from a tidal flat area of Dae and energy sources. A phylogenetic analysis based on 16S rRNA gene sequences revealed that the strains belong

  9. Expressions for Tidal Conversion at Seafloor Topography using Physical-Space Integrals

    E-Print Network [OSTI]

    Schörghofer, Norbert

    Expressions for Tidal Conversion at Seafloor Topography using Physical-Space Integrals Norbert and a potential source of the required mechanical energy is the generation and breaking of internal gravity waves (Egbert and Ray, 2000; Ledwell et al., 2000). Tidal dissipation has long been recognized as important

  10. Laboratory studies of eddy structures and exchange processes through tidal inlets 

    E-Print Network [OSTI]

    Nicolau del Roure, Francisco

    2009-06-02

    , Germany, which has the capability to generate a sinusoidal flow that simulates a series of tidal cycles. A set of idealized inlets were arranged in the tank, and by varying the tidal period and the maximum velocity, three different types of life...

  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. Cross-shore suspended sediment transport under tidal currents Andrew J. Hogg1

    E-Print Network [OSTI]

    Hogg, Andrew

    Cross-shore suspended sediment transport under tidal currents Andrew J. Hogg1 and David Pritchard2-mail: david@bpi.cam.ac.uk Abstract The transport of sediment over an intertidal mudflat by a cross-shore tidal-layer approximation. It is found that the sediment transport comprises advection with the mean flow, deposition

  13. Chapter 5 -Sediment, Nutrient, and Vegetation Trends Along the Tidal, Forested Pocomoke

    E-Print Network [OSTI]

    Chapter 5 - Sediment, Nutrient, and Vegetation Trends Along the Tidal, Forested Pocomoke River-tidal upstream sites. Floodplain sediments in the past W.H. Conner, T.W. Doyle, and K.W. Krauss (eds.), Ecology]). These sediments overlie hundreds of meters of Tertiary (2-65 mybp) greensands and clay- silt. The Tertiary

  14. 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 only be practical at power penetration levels less than 20%. #12;iv Table of Contents Supervisory

  15. Constraining the High-Density Behavior of Nuclear Symmetry Energy with the Tidal Polarizability of Neutron Stars

    E-Print Network [OSTI]

    F. J. Fattoyev; J. Carvajal; W. G. Newton; Bao-An Li

    2012-10-12

    Using a set of model equations of state satisfying the latest constraints from both terrestrial nuclear experiments and astrophysical observations as well as state-of-the-art nuclear many-body calculations of the pure neutron matter equation of state, the tidal polarizability of canonical neutron stars in coalescing binaries is found to be a very sensitive probe of the high-density behavior of nuclear symmetry energy which is among the most uncertain properties of dense neutron-rich nucleonic matter. Moreover, it changes less than $\\pm 10%$ by varying various properties of symmetric nuclear matter and symmetry energy around the saturation density within their respective ranges of remaining uncertainty.

  16. Constraining the High-Density Behavior of Nuclear Symmetry Energy with the Tidal Polarizability of Neutron Stars

    E-Print Network [OSTI]

    Fattoyev, F J; Newton, W G; Li, Bao-An

    2012-01-01

    Using a set of model equations of state satisfying the latest constraints from both terrestrial nuclear experiments and astrophysical observations as well as state-of-the-art nuclear many-body calculations of the pure neutron matter equation of state, the tidal polarizability of canonical neutron stars in coalescing binaries is found to be a very sensitive probe of the high-density behavior of nuclear symmetry energy which is among the most uncertain properties of dense neutron-rich nucleonic matter. Moreover, it changes less than $\\pm 10%$ by varying various properties of symmetric nuclear matter and symmetry energy around the saturation density within their respective ranges of remaining uncertainty.

  17. MODELING OF TRIPLE JUNCTION A-SI SOLAR CELLS USING ASA: ANALYSIS OF DEVICE PERFORMANCE UNDER VARIOUS FAILURE SCENARIOS

    E-Print Network [OSTI]

    Deng, Xunming

    solar cells and/or the comparison of these predicted results with real multi-junction devices have beenMODELING OF TRIPLE JUNCTION A-SI SOLAR CELLS USING ASA: ANALYSIS OF DEVICE PERFORMANCE UNDER, University of Toledo, Toledo, OH 43606 ABSTRACT Triple junction a-Si solar cells have been modeled

  18. Video Analysis and Modeling Performance Task to promote becoming like scientists in classrooms

    E-Print Network [OSTI]

    Wee, Loo Kang

    2015-01-01

    This paper aims to share the use of Tracker a free open source video analysis and modeling tool that is increasingly used as a pedagogical tool for the effective learning and teaching of Physics for Grade 9 Secondary 3 students in Singapore schools to make physics relevant to the real world. We discuss the pedagogical use of Tracker, guided by the Framework for K-12 Science Education by National Research Council, USA to help students to be more like scientists. For a period of 6 to 10 weeks, students use a video analysis coupled with the 8 practices of sciences such as 1. Ask question, 2. Use models, 3. Plan and carry out investigation, 4. Analyse and interpret data, 5. Use mathematical and computational thinking, 6. Construct explanations, 7. Argue from evidence and 8. Communicate information. This papers focus in on discussing some of the performance task design ideas such as 3.1 flip video, 3.2 starting with simple classroom activities, 3.3 primer science activity, 3.4 integrative dynamics and kinematics l...

  19. Modeling Constituent Redistribution in U-Pu-Zr Metallic Fuel Using the Advanced Fuel Performance Code BISON

    SciTech Connect (OSTI)

    Douglas Porter; Steve Hayes; Various

    2014-06-01

    The Advanced Fuels Campaign (AFC) metallic fuels currently being tested have higher zirconium and plutonium concentrations than those tested in the past in EBR reactors. Current metal fuel performance codes have limitations and deficiencies in predicting AFC fuel performance, particularly in the modeling of constituent distribution. No fully validated code exists due to sparse data and unknown modeling parameters. Our primary objective is to develop an initial analysis tool by incorporating state-of-the-art knowledge, constitutive models and properties of AFC metal fuels into the MOOSE/BISON (1) framework in order to analyze AFC metallic fuel tests.

  20. Model Analysis on the Performance for an Inertial Aided FLL-Assisted-PLL Carrier-

    E-Print Network [OSTI]

    Stanford University

    Integrity Performance Panel (WIPP) that focuses on the implementation of WAAS and the development of its

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

    E-Print Network [OSTI]

    to characterize the conversion of tidal energy to radiated internal wave power. Whether the hydrostatic ( , shape)/SIW, where Ptide is the effective tidal power that interacts with the topography, and /8 of the oceans. Therefore, it is useful to measure the total power PIW converted from barotropic tidal motions

  2. Estimation vido haute frquence de la topographie inter-tidale d'une plage sableuse : application la

    E-Print Network [OSTI]

    Estimation vidéo haute fréquence de la topographie inter- tidale d'une plage sableuse : application outil vidéo d'estimation haute fréquence de la topographie inter-tidale. Cet outil est basé sur le suivi : We present a tool to estimate inter-tidal topography using video images. This tool is based

  3. Tidal front affects the size of prey used by a top marine predator, the short-tailed shearwater (Puffinus tenuirostris)

    E-Print Network [OSTI]

    Tidal front affects the size of prey used by a top marine predator, the short-tailed shearwater densities of small euphausiids were associated with a tidal front on the north side of Akutan Pass. At most sites elsewhere in the Bering Sea, away from tidal fronts, shearwaters selected larger (14.2­20.1 mm

  4. OPTICAL DISCOVERY OF PROBABLE STELLAR TIDAL DISRUPTION FLARES

    SciTech Connect (OSTI)

    Van Velzen, Sjoert; Farrar, Glennys R. [Center for Cosmology and Particle Physics, New York University, NY 10003 (United States); Gezari, Suvi [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Morrell, Nidia [Carnegie Observatories, Las Campanas Observatory, Casillas 601, La Serena (Chile); Zaritsky, Dennis [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Oestman, Linda [Institut de Fisica d'Altes Energies, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Barcelona) (Spain); Smith, Mathew [Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch, 7701 (South Africa); Gelfand, Joseph [New York University-Abu Dhabi, Abu Dhabi (United Arab Emirates); Drake, Andrew J., E-mail: s.vanvelzen@astro.ru.nl [Center for Advance Computing Research, California Institute of Technology, Pasadena, CA 91225 (United States)

    2011-11-10

    Using archival Sloan Digital Sky Survey (SDSS) multi-epoch imaging data (Stripe 82), we have searched for the tidal disruption of stars by supermassive black holes in non-active galaxies. Two candidate tidal disruption events (TDEs) are identified. The TDE flares have optical blackbody temperatures of 2 Multiplication-Sign 10{sup 4} K and observed peak luminosities of M{sub g} = -18.3 and -20.4 ({nu}L{sub {nu}} = 5 Multiplication-Sign 10{sup 42}, 4 Multiplication-Sign 10{sup 43} erg s{sup -1}, in the rest frame); their cooling rates are very low, qualitatively consistent with expectations for tidal disruption flares. The properties of the TDE candidates are examined using (1) SDSS imaging to compare them to other flares observed in the search, (2) UV emission measured by GALEX, and (3) spectra of the hosts and of one of the flares. Our pipeline excludes optically identifiable AGN hosts, and our variability monitoring over nine years provides strong evidence that these are not flares in hidden AGNs. The spectra and color evolution of the flares are unlike any SN observed to date, their strong late-time UV emission is particularly distinctive, and they are nuclear at high resolution arguing against these being first cases of a previously unobserved class of SNe or more extreme examples of known SN types. Taken together, the observed properties are difficult to reconcile with an SN or an AGN-flare explanation, although an entirely new process specific to the inner few hundred parsecs of non-active galaxies cannot be excluded. Based on our observed rate, we infer that hundreds or thousands of TDEs will be present in current and next-generation optical synoptic surveys. Using the approach outlined here, a TDE candidate sample with O(1) purity can be selected using geometric resolution and host and flare color alone, demonstrating that a campaign to create a large sample of TDEs, with immediate and detailed multi-wavelength follow-up, is feasible. A by-product of this work is quantification of the power spectrum of extreme flares in AGNs.

  5. Technical Approach for Determining Key Parameters Needed for Modeling the Performance of Cast Stone for the Integrated Disposal Facility Performance Assessment

    SciTech Connect (OSTI)

    Yabusaki, Steven B.; Serne, R. Jeffrey; Rockhold, Mark L.; Wang, Guohui; Westsik, Joseph H.

    2015-03-30

    Washington River Protection Solutions (WRPS) and its contractors at Pacific Northwest National Laboratory (PNNL) and Savannah River National Laboratory (SRNL) are conducting a development program to develop / refine the cementitious waste form for the wastes treated at the ETF and to provide the data needed to support the IDF PA. This technical approach document is intended to provide guidance to the cementitious waste form development program with respect to the waste form characterization and testing information needed to support the IDF PA. At the time of the preparation of this technical approach document, the IDF PA effort is just getting started and the approach to analyze the performance of the cementitious waste form has not been determined. Therefore, this document looks at a number of different approaches for evaluating the waste form performance and describes the testing needed to provide data for each approach. Though the approach addresses a cementitious secondary aqueous waste form, it is applicable to other waste forms such as Cast Stone for supplemental immobilization of Hanford LAW. The performance of Cast Stone as a physical and chemical barrier to the release of contaminants of concern (COCs) from solidification of Hanford liquid low activity waste (LAW) and secondary wastes processed through the Effluent Treatment Facility (ETF) is of critical importance to the Hanford Integrated Disposal Facility (IDF) total system performance assessment (TSPA). The effectiveness of cementitious waste forms as a barrier to COC release is expected to evolve with time. PA modeling must therefore anticipate and address processes, properties, and conditions that alter the physical and chemical controls on COC transport in the cementitious waste forms over time. Most organizations responsible for disposal facility operation and their regulators support an iterative hierarchical safety/performance assessment approach with a general philosophy that modeling provides the critical link between the short-term understanding from laboratory and field tests, and the prediction of repository performance over repository time frames and scales. One common recommendation is that experiments be designed to permit the appropriate scaling in the models. There is a large contrast in the physical and chemical properties between the Cast Stone waste package and the IDF backfill and surrounding sediments. Cast Stone exhibits low permeability, high tortuosity, low carbonate, high pH, and low Eh whereas the backfill and native sediments have high permeability, low tortuosity, high carbonate, circumneutral pH, and high Eh. These contrasts have important implications for flow, transport, and reactions across the Cast Stone – backfill interface. Over time with transport across the interface and subsequent reactions, the sharp geochemical contrast will blur and there will be a range of spatially-distributed conditions. In general, COC mobility and transport will be sensitive to these geochemical variations, which also include physical changes in porosity and permeability from mineral reactions. Therefore, PA modeling must address processes, properties, and conditions that alter the physical and chemical controls on COC transport in the cementitious waste forms over time. Section 2 of this document reviews past Hanford PAs and SRS Saltstone PAs, which to date have mostly relied on the lumped parameter COC release conceptual models for TSPA predictions, and provides some details on the chosen values for the lumped parameters. Section 3 provides more details on the hierarchical modeling strategy and processes and mechanisms that control COC release. Section 4 summarizes and lists the key parameters for which numerical values are needed to perform PAs. Section 5 provides brief summaries of the methods used to measure the needed parameters and references to get more details.

  6. An improved blade passage model for estimating off-design axial compressor performance

    E-Print Network [OSTI]

    Brand, Maximilian Lewis

    2013-01-01

    Accurate estimates of multistage axial compressor performance at off-design operating conditions are essential to the determination of key performance metrics of aircraft gas turbine engines, such as fuel burn, thrust ...

  7. Tidal Charged Black Holes as Particle Accelerators to Arbitrarily High Energy

    E-Print Network [OSTI]

    Pradhan, Parthapratim

    2014-01-01

    We show that Randall Sundrum tidal charged spherically symmetric vacuum brane black holes could be act as a particle accelerator with ultrahigh center-of-mass energy in the limiting case of \\emph{ maximal black hole tidal charge}. For non-extremal Randall Sundrum tidal charged black hole, the center-of-mass energy is finite. While for maximally Randall Sundrum tidal charged black hole, the center-of-mass energy is \\emph{infinite}. We have also derived the center-of-mass energy at ISCO(Innermost Stable Circular Orbit) or LSCO(Last Stable Circular Orbit) or MSCO(Marginally Stable Circular Orbit) and MBCO (Marginally Bound Circular Orbit) for maximally Randall Sundrum tidal charged black hole. We show visually the differences between Reissner-Nordstr{\\o}m black hole and Randall Sundrum tidal charged BH. We have found that for maximally Randall Sundrum tidal charged black hole the center-of-mass energy is satisfied the following inequality: $E_{cm}\\mid_{r_{+}}>E_{cm}\\mid_{r_{mb}}>E_{cm}\\mid_{r_{ISCO}}$ i.e. $E_{c...

  8. Tidal Charged Black Holes as Particle Accelerators to Arbitrarily High Energy

    E-Print Network [OSTI]

    Parthapratim Pradhan

    2014-12-28

    We show that Randall Sundrum tidal charged spherically symmetric vacuum brane black holes could be act as a particle accelerator with ultrahigh center-of-mass energy in the limiting case of \\emph{ maximal black hole tidal charge}. For non-extremal Randall Sundrum tidal charged black hole, the center-of-mass energy is finite. While for maximally Randall Sundrum tidal charged black hole, the center-of-mass energy is \\emph{infinite}. We have also derived the center-of-mass energy at ISCO(Innermost Stable Circular Orbit) or LSCO(Last Stable Circular Orbit) or MSCO(Marginally Stable Circular Orbit) and MBCO (Marginally Bound Circular Orbit) for maximally Randall Sundrum tidal charged black hole. We show visually the differences between Reissner-Nordstr{\\o}m black hole and Randall Sundrum tidal charged BH. We have found that for maximally Randall Sundrum tidal charged black hole the center-of-mass energy is satisfied the following inequality: $E_{cm}\\mid_{r_{+}}>E_{cm}\\mid_{r_{mb}}>E_{cm}\\mid_{r_{ISCO}}$ i.e. $E_{cm}\\mid_{r_{+} = \\frac{M}{M_{p}^2}}: E_{cm}\\mid_{r_{mb} = \\left(\\frac{3+\\sqrt{5}}{2}\\right)\\frac{M}{M_{p}^2}}:E_{cm}\\mid_{r_{ISCO} = 4\\frac{M}{M_{p}^2}} = \\infty: 3.23 : 2.6$. Which is exactly \\emph{similar} to the spherically symmetric extreme Reissner-Nordstr\\"{o}m black hole.}

  9. Modeling and Simulation Environment for Photonic Interconnection Networks in High Performance Computing

    E-Print Network [OSTI]

    Bergman, Keren

    at the scale of high performance computer clusters and warehouse scale data centers, system level simulations and results for rack scale photonic interconnection networks for high performance computing. Keywords: optical to the newsworthy power consumption [3], latency [4] and bandwidth challenges [5] of high performance computing (HPC

  10. Architecture, Data Model and Real-Time Performance Evaluation of the Streamonas Data Stream Management System

    E-Print Network [OSTI]

    Michael, Panayiotis Adamos

    2015-01-01

    in active databases: Model and implementation”. In VLDB,Bassam Islam, "Stack Database Model/View of Multimedia Data"implementing a fragmented database model of Spatio-Temporal

  11. Low Temperature Performance: Performance Modeling

    Broader source: Energy.gov [DOE]

    Presentation from the U.S. DOE Office of Vehicle Technologies "Mega" Merit Review 2008 on February 25, 2008 in Bethesda, Maryland.

  12. Microsoft Word - RM1_Tidal Turbine_UW Tidal Resource-Abstract.doc

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on77 PAGE OFDetection of Hydrates onRHUBC Operations2,Reference Model

  13. Hyperaccretion during tidal disruption events: Weakly bound debris envelopes and jets

    SciTech Connect (OSTI)

    Coughlin, Eric R.; Begelman, Mitchell C., E-mail: eric.coughlin@colorado.edu, E-mail: mitch@jila.colorado.edu [Also at Department of Astrophysical and Planetary Sciences, University of Colorado, UCB 391, Boulder, CO 80309, USA. (United States)

    2014-02-01

    After the destruction of the star during a tidal disruption event (TDE), the cataclysmic encounter between a star and the supermassive black hole (SMBH) of a galaxy, approximately half of the original stellar debris falls back onto the hole at a rate that can initially exceed the Eddington limit by orders of magnitude. We argue that the angular momentum of this matter is too low to allow it to attain a disk-like configuration with accretion proceeding at a mildly super-Eddington rate, the excess energy being carried away by a combination of radiative losses and radially distributed winds. Instead, we propose that the infalling gas traps accretion energy until it inflates into a weakly bound, quasi-spherical structure with gas extending nearly to the poles. We study the structure and evolution of such 'zero-Bernoulli accretion' flows as a model for the super-Eddington phase of TDEs. We argue that such flows cannot stop extremely super-Eddington accretion from occurring, and that once the envelope is maximally inflated, any excess accretion energy escapes through the poles in the form of powerful jets. We compare the predictions of our model to Swift J1644+57, the putative super-Eddington TDE, and show that it can qualitatively reproduce some of its observed features. Similar models, including self-gravity, could be applicable to gamma-ray bursts from collapsars and the growth of SMBH seeds inside quasi-stars.

  14. Tidal Stream Morphology as an Indicator of Dark Matter Halo Geometry: the Case of Palomar 5

    E-Print Network [OSTI]

    Pearson, Sarah; Johnston, Kathryn V; Price-Whelan, Adrian M

    2014-01-01

    This paper presents an example where the morphology of a single stellar stream can be used to rule out a specific galactic potential form without the need for velocity information. We investigate the globular cluster Palomar5 (Pal 5), which is tidally disrupting into a cold, thin stream mapped over 22 degrees on the sky with a typical width of 0.7 degrees. We generate models of this stream by fixing Pal 5's present-day position, distance and radial velocity via observations, while allowing its proper motion to vary. In a spherical dark matter halo we easily find models that fit the observed morphology. However, no plausible Pal 5 model could be found in the triaxial potential of Law & Majewski (2010), which has been proposed to explain the properties of the Sagittarius stream. In this case, the long, thin and curved morphology of the Pal5 stream alone can be used to rule out such a potential configuration. Pal 5 like streams in this potential are either too straight, missing the curvature of the observati...

  15. ScoPred--Scalable User-Directed Performance Prediction Using Complexity Modeling and Historical Data

    E-Print Network [OSTI]

    Feitelson, Dror

    complexity models, good prediction accuracy can be obtained. 1 Introduction The typical approach in parallel, partic

  16. A Multi-Methods Approach to HRA and Human Performance Modeling: A Field Assessment

    SciTech Connect (OSTI)

    Jacques Hugo; David I Gertman

    2012-06-01

    The Advanced Test Reactor (ATR) is a research reactor at the Idaho National Laboratory is primarily designed and used to test materials to be used in other, larger-scale and prototype reactors. The reactor offers various specialized systems and allows certain experiments to be run at their own temperature and pressure. The ATR Canal temporarily stores completed experiments and used fuel. It also has facilities to conduct underwater operations such as experiment examination or removal. In reviewing the ATR safety basis, a number of concerns were identified involving the ATR canal. A brief study identified ergonomic issues involving the manual handling of fuel elements in the canal that may increase the probability of human error and possible unwanted acute physical outcomes to the operator. In response to this concern, that refined the previous HRA scoping analysis by determining the probability of the inadvertent exposure of a fuel element to the air during fuel movement and inspection was conducted. The HRA analysis employed the SPAR-H method and was supplemented by information gained from a detailed analysis of the fuel inspection and transfer tasks. This latter analysis included ergonomics, work cycles, task duration, and workload imposed by tool and workplace characteristics, personal protective clothing, and operational practices that have the potential to increase physical and mental workload. Part of this analysis consisted of NASA-TLX analyses, combined with operational sequence analysis, computational human performance analysis (CHPA), and 3D graphical modeling to determine task failures and precursors to such failures that have safety implications. Experience in applying multiple analysis techniques in support of HRA methods is discussed.

  17. Topological Performance Measures as Surrogates for Physical Flow Models for Risk and Vulnerability Analysis for Electric Power Systems

    E-Print Network [OSTI]

    LaRocca, Sarah; Hassel, Henrik; Guikema, Seth

    2013-01-01

    Critical infrastructure systems must be both robust and resilient in order to ensure the functioning of society. To improve the performance of such systems, we often use risk and vulnerability analysis to find and address system weaknesses. A critical component of such analyses is the ability to accurately determine the negative consequences of various types of failures in the system. Numerous mathematical and simulation models exist which can be used to this end. However, there are relatively few studies comparing the implications of using different modeling approaches in the context of comprehensive risk analysis of critical infrastructures. Thus in this paper, we suggest a classification of these models, which span from simple topologically-oriented models to advanced physical flow-based models. Here, we focus on electric power systems and present a study aimed at understanding the tradeoffs between simplicity and fidelity in models used in the context of risk analysis. Specifically, the purpose of this pa...

  18. Recommended Method To Account For Daughter Ingrowth For The Portsmouth On-Site Waste Disposal Facility Performance Assessment Modeling

    SciTech Connect (OSTI)

    Phifer, Mark A.; Smith, Frank G. III

    2013-06-21

    A 3-D STOMP model has been developed for the Portsmouth On-Site Waste Disposal Facility (OSWDF) at Site D as outlined in Appendix K of FBP 2013. This model projects the flow and transport of the following radionuclides to various points of assessments: Tc-99, U-234, U-235, U-236, U-238, Am-241, Np-237, Pu-238, Pu-239, Pu-240, Th-228, and Th-230. The model includes the radioactive decay of these parents, but does not include the associated daughter ingrowth because the STOMP model does not have the capability to model daughter ingrowth. The Savannah River National Laboratory (SRNL) provides herein a recommended method to account for daughter ingrowth in association with the Portsmouth OSWDF Performance Assessment (PA) modeling.

  19. Model-Based Functional Performance Testing of AHU in Kista Entre 

    E-Print Network [OSTI]

    Carling, P.; Isakson, P.

    2004-01-01

    A seasonal functional performance test based on detailed system simulation together with intensive trending is used to commission a large AHU in the office building, Kista Entré, Sweden....

  20. Modeling and Simulation Approaches to Developing Human Performance Measures in Nuclear Industry

    SciTech Connect (OSTI)

    Bruce P. Hallbert; Jeffrey C. Joe; Molly J. Keefe; Julius J. Persensky

    2007-08-01

    Human performance is a key component to the safe operation of nuclear power plants. Further, human performance is quite variable, and while some variability may be random, much of it may be attributed to factors that are difficult to assess. There is a need to identify and assess aspects of human performance that relate to plant safety and to develop measures that can be used to successfully assess human performance for purposes of research that can lead to technical basis for developing human factors review criteria.

  1. Model-Based Performance Risk Analysis Vittorio Cortellessa, Katerina Goseva-Popstojanova, Senior Member, IEEE, Kalaivani Appukkutty,

    E-Print Network [OSTI]

    Goseva-Popstojanova, Katerina

    Model-Based Performance Risk Analysis Vittorio Cortellessa, Katerina Goseva-Popstojanova, Senior such type of risk analysis. Finally, we introduce a methodology to obtain, from annotated Sequence Diagrams introduces the basic concepts of risk analysis along with an overview of the related work. In Section 3, we

  2. Preliminary Review of Models, Assumptions, and Key Data used in Performance Assessments and Composite Analysis at the Idaho National Laboratory

    SciTech Connect (OSTI)

    Arthur S. Rood; Swen O. Magnuson

    2009-07-01

    This document is in response to a request by Ming Zhu, DOE-EM to provide a preliminary review of existing models and data used in completed or soon to be completed Performance Assessments and Composite Analyses (PA/CA) documents, to identify codes, methodologies, main assumptions, and key data sets used.

  3. 1 Oxidation of Ethidium Using TAML Activators: A Model for High 2 School Research Performed in Partnership with University Scientists

    E-Print Network [OSTI]

    Blumberg, Bruce

    1 Oxidation of Ethidium Using TAML Activators: A Model for High 2 School Research Performed Bruce Blumberg,§ Terrence J. Collins, and Steven G. Sogo*, 6 Laguna Beach High School, Laguna Beach ABSTRACT: A chemical research program at a public high school has been 12 developed. The full-year Advanced

  4. Device modeling and simulation of the performance of Cu(In1x,Gax)Se2 solar cells

    E-Print Network [OSTI]

    Anderson, Timothy J.

    -junction Cu(In1Àx,Gax)Se2 (CIGS) solar cells. Increasing the open-circuit voltage (Voc) to improve the overallDevice modeling and simulation of the performance of Cu(In1Àx,Gax)Se2 solar cells Jiyon Song solar cell have been carried out. A variety of graded band-gap structures, including space charge region

  5. Performance Assessment Transport Modeling of Uranium at the Area 5 Radioactive Waste Management Site at the Nevada National Security Site

    SciTech Connect (OSTI)

    NSTec Radioactive Waste

    2010-10-12

    Following is a brief summary of the assumptions that are pertinent to the radioactive isotope transport in the GoldSim Performance Assessment model of the Area 5 Radioactive Waste Management Site, with special emphasis on the water-phase reactive transport of uranium, which includes depleted uranium products.

  6. Quantifying uncertainty in estimates of mineral dust flux: An intercomparison of model performance over the Bodele Depression,

    E-Print Network [OSTI]

    's radiation budget through absorption and scattering of solar and terrestrial radiation, (2) the indirect and regional, but to date, there have been few attempts to compare the performance of these models impact of mineral dust in particular is relatively poorly understood, despite evidence that the radiative

  7. Supply Chain Performance Assessment and Supplier and Component Importance Identification General Competitive Multitiered Supply Chain Network Model

    E-Print Network [OSTI]

    Nagurney, Anna

    Supply Chain Performance Assessment and Supplier and Component Importance Identification competitive supply chain network game theory model, which includes the supplier tier. The firms components from one or more suppliers, who also are capacitated. The firms compete in a Cournot-Nash fashion

  8. Effects of Tidal Turbine Noise on Fish Task 2.1.3.2: Effects on Aquatic Organisms: Acoustics/Noise - Fiscal Year 2011 - Progress Report - Environmental Effects of Marine and Hydrokinetic Energy

    SciTech Connect (OSTI)

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

    2011-09-30

    Naturally spawning stocks of Chinook salmon (Oncorhynchus tshawytscha) that utilize Puget Sound are listed as threatened (http://www.nwr.noaa.gov/ESA-Salmon-Listings/Salmon-Populations/ Chinook/CKPUG.cfm). 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 (Effects on Aquatic Organisms, Subtask 2.1.3.2: Acoustics) was performed during FY 2011 to determine if noise generated by a 6-m-diameter open-hydro turbine might affect juvenile Chinook salmon hearing or cause barotrauma. 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). Preliminary results indicate that 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.

  9. Tidal energy effects of dark matter halos on early-type galaxies

    E-Print Network [OSTI]

    Valentinuzzi, T; D'Onofrio, M

    2010-01-01

    Tidal interactions between neighboring objects span across the whole admissible range of lengths in nature: from, say, atoms to clusters of galaxies i.e. from micro to macrocosms. According to current cosmological theories, galaxies are embedded within massive non-baryonic dark matter (DM) halos, which affects their formation and evolution. It is therefore highly rewarding to understand the role of tidal interaction between the dark and luminous matter in galaxies. The current investigation is devoted to Early-Type Galaxies (ETGs), looking in particular at the possibility of establishing whether the tidal interaction of the DM halo with the luminous baryonic component may be at the origin of the so-called "tilt" of the Fundamental Plane (FP). The extension of the tensor virial theorem to two-component matter distributions implies the calculation of the self potential energy due to a selected subsystem, and the tidal potential energy induced by the other one. The additional assumption of homeoidally striated d...

  10. Sudden increase in tidal response linked to calving and acceleration at a large Greenland outlet glacier

    E-Print Network [OSTI]

    de Juan, J.; Elosegui, P.; Nettles, M.; Larsen, T. B.; Davis, J. L.; Hamilton, Gordon S.; Stearns, Leigh; Anderson, M. L.; Ekstrom, G.; Ahlstrom, A. P.; Stenseng, L.; Khan, S. A.; Forsberg, R.

    2010-06-23

    [1] Large calving events at Greenland's largest outlet glaciers are associated with glacial earthquakes and near-instantaneous increases in glacier flow speed. At some glaciers and ice streams, flow is also modulated in a regular way by ocean tidal...

  11. Saltwater Incursion into Micro Tidal Wetlands: Case Studies from Matagorda, Texas and Humacao, Puerto Rico 

    E-Print Network [OSTI]

    Colon, Ricardo J.

    2013-08-27

    Global climate change threatens the survival of microtidal wetlands by altering fundamental hydrological aspects such as precipitation patterns and tidal exchange. The combination of these stressors results in increased flooding period and soil...

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

    SciTech Connect (OSTI)

    Musial, W.

    2008-08-01

    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.

  13. Maine Project Takes Historic Step Forward in U.S. Tidal Energy...

    Energy Savers [EERE]

    contracts will be in place for 20 years -- making them the first long-term tidal energy power purchase agreements in the United States. The implications of these agreements are...

  14. Dispersion Mechanisms of a Tidal River Junction in the Sacramento–San Joaquin Delta, California

    E-Print Network [OSTI]

    Gleichauf, Karla T.; Wolfram, Phillip J.; Monsen, Nancy E.; Fringer, Oliver B.; Monismith, Stephen G.

    2014-01-01

    a Tidal River Junction in the Sacramento–San Joaquin Delta,networks, such as in the Sacramento–San Joaquin River Delta,transport and fate in the Sacramento–San Joaquin delta using

  15. Microsoft Word - RM1_Tidal Turbine_NREL Bir, Lawson, Li_2011...

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

    Arctic Engineering OMAE2011 June 19-24, 20111, Rotterdam, the Netherland OMAE2011-50063 STRUCTURAL DESIGN OF A HORIZONTAL-AXIS TIDAL CURRENT TURBINE COMPOSITE BLADE ABSTRACT This...

  16. ORGANIC MATTER DISTRIBUTION AND TURNOVER ALONG A GRADIENT FROM FOREST TO TIDAL CREEK

    E-Print Network [OSTI]

    Lawrence, Deborah

    i ORGANIC MATTER DISTRIBUTION AND TURNOVER ALONG A GRADIENT FROM FOREST TO TIDAL CREEK A Thesis. A nested plot design was used to harvest vegetation, obtain soil cores, and collect quantitative data... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .18 Qualitative Vegetation Analysis

  17. Maine Deploys First U.S. Commercial, Grid-Connected Tidal Energy...

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

    of President Obama's all-of-the-above energy strategy to create jobs and strengthen U.S. global competitiveness," said Energy Secretary Steven Chu. "The Eastport tidal energy...

  18. A biomathematical model of the restoring effects of caffeine on cognitive performance during sleep deprivation

    E-Print Network [OSTI]

    Squared Error n Correspondence to: DoD Biotechnology High Performance Computing Soft- ware Applications , Gary H. Kamimori b , Thomas J. Balkin b , Jaques Reifman a,n a DoD Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army

  19. EVIDENCE FOR A MILKY WAY TIDAL STREAM REACHING BEYOND 100 kpc

    SciTech Connect (OSTI)

    Drake, A. J.; Djorgovski, S. G.; Graham, M. J.; Mahabal, A.; Donalek, C.; Williams, R. [California Institute of Technology, 1200 E. California Blvd., CA 91225 (United States); Catelan, M.; Torrealba, G. [Pontificia Universidad Catolica de Chile, Departamento de Astronomia y Astrofisica, Facultad de Fisica, Av. Vicuna Mackena 4860, 782-0436 Macul, Santiago (Chile); Prieto, J. L. [Department of Astronomy, Princeton University, 4 Ivy Lane, Princeton, NJ 08544 (United States); Larson, S.; Christensen, E.; Beshore, E. [Department of Planetary Sciences, University of Arizona, Lunar and Planetary Laboratory, 1629 E. University Blvd., Tucson AZ 85721 (United States)

    2013-03-10

    We present the analysis of 1207 RR Lyrae found in photometry taken by the Catalina Survey's Mount Lemmon telescope. By combining accurate distances for these stars with measurements for {approx}14,000 type-ab RR Lyrae from the Catalina Schmidt telescope, we reveal an extended association that reaches Galactocentric distances beyond 100 kpc and overlaps the Sagittarius stream system. This result confirms earlier evidence for the existence of an outer halo tidal stream resulting from a disrupted stellar system. By comparing the RR Lyrae source density with that expected based on halo models, we find the detection has {approx}8{sigma} significance. We investigate the distances, radial velocities, metallicities, and period-amplitude distribution of the RR Lyrae. We find that both radial velocities and distances are inconsistent with current models of the Sagittarius stream. We also find tentative evidence for a division in source metallicities for the most distant sources. Following prior analyses, we compare the locations and distances of the RR Lyrae with photometrically selected candidate horizontal branch stars and find supporting evidence that this structure spans at least 60 Degree-Sign of the sky. We investigate the prospects of an association between the stream and the unusual globular cluster NGC 2419.

  20. Reference Models and Incentive Regulation of Electricity Distribution Networks: An Evaluation of Sweden’s Network Performance Assessment Model (NPAM)

    E-Print Network [OSTI]

    Jamasb, Tooraj; Pollitt, Michael G.

    (Capex), quality of service, and network losses in a single model. Aggregation of these important elements into a single model has useful efficiency and incentive properties. Firms can adjust their inputs and outputs more efficiently by weighting... long-term benchmarking model, the NPAM incorporates the main inputs and outputs of regulatory concern such as operating and maintenance expenditures (Opex), capital expenditures (Capex), service quality, and network energy losses. It is generally...