National Library of Energy BETA

Sample records for larger core models

  1. The core legion object model

    SciTech Connect (OSTI)

    Lewis, M.; Grimshaw, A.

    1996-12-31

    The Legion project at the University of Virginia is an architecture for designing and building system services that provide the illusion of a single virtual machine to users, a virtual machine that provides secure shared object and shared name spaces, application adjustable fault-tolerance, improved response time, and greater throughput. Legion targets wide area assemblies of workstations, supercomputers, and parallel supercomputers, Legion tackles problems not solved by existing workstation based parallel processing tools; the system will enable fault-tolerance, wide area parallel processing, inter-operability, heterogeneity, a single global name space, protection, security, efficient scheduling, and comprehensive resource management. This paper describes the core Legion object model, which specifies the composition and functionality of Legion`s core objects-those objects that cooperate to create, locate, manage, and remove objects in the Legion system. The object model facilitates a flexible extensible implementation, provides a single global name space, grants site autonomy to participating organizations, and scales to millions of sites and trillions of objects.

  2. The role of subsurface flows in solar surface convection: modeling the spectrum of supergranular and larger scale flows

    SciTech Connect (OSTI)

    Lord, J. W.; Rast, M. P.; Cameron, R. H.; Rempel, M.; Roudier, T.

    2014-09-20

    We model the solar horizontal velocity power spectrum at scales larger than granulation using a two-component approximation to the mass continuity equation. The model takes four times the density scale height as the integral (driving) scale of the vertical motions at each depth. Scales larger than this decay with height from the deeper layers. Those smaller are assumed to follow a Kolmogorov turbulent cascade, with the total power in the vertical convective motions matching that required to transport the solar luminosity in a mixing length formulation. These model components are validated using large-scale radiative hydrodynamic simulations. We reach two primary conclusions. (1) The model predicts significantly more power at low wavenumbers than is observed in the solar photospheric horizontal velocity spectrum. (2) Ionization plays a minor role in shaping the observed solar velocity spectrum by reducing convective amplitudes in the regions of partial helium ionization. The excess low wavenumber power is also seen in the fully nonlinear three-dimensional radiative hydrodynamic simulations employing a realistic equation of state. This adds to other recent evidence suggesting that the amplitudes of large-scale convective motions in the Sun are significantly lower than expected. Employing the same feature tracking algorithm used with observational data on the simulation output, we show that the observed low wavenumber power can be reproduced in hydrodynamic models if the amplitudes of large-scale modes in the deep layers are artificially reduced. Since the large-scale modes have reduced amplitudes, modes on the scale of supergranulation and smaller remain important to convective heat flux even in the deep layers, suggesting that small-scale convective correlations are maintained through the bulk of the solar convection zone.

  3. Comprehensive chemical kinetic modeling of the oxidation of C8 and larger n-alkanes and 2-methylalkanes

    SciTech Connect (OSTI)

    Sarathy, S M; Westbrook, C K; Pitz, W J; Mehl, M; Togbe, C; Dagaut, P; Wang, H; Oehlschlaeger, M; NIemann, U; Seshadri, K; Veloo, P S; Ji, C; Egolfopoulos, F; Lu, T

    2011-03-16

    Conventional petroleum jet and diesel fuels, as well as alternative Fischer-Tropsch (FT) fuels and hydrotreated renewable jet (HRJ) fuels, contain high molecular weight lightly branched alkanes (i.e., methylalkanes) and straight chain alkanes (n-alkanes). Improving the combustion of these fuels in practical applications requires a fundamental understanding of large hydrocarbon combustion chemistry. This research project presents a detailed and reduced chemical kinetic mechanism for singly methylated iso-alkanes (i.e., 2-methylalkanes) ranging from C{sub 8} to C{sub 20}. The mechanism also includes an updated version of our previously published C{sub 8} to C{sub 16} n-alkanes model. The complete detailed mechanism contains approximately 7,200 species 31,400 reactions. The proposed model is validated against new experimental data from a variety of fundamental combustion devices including premixed and nonpremixed flames, perfectly stirred reactors and shock tubes. This new model is used to show how the presence of a methyl branch affects important combustion properties such as laminar flame propagation, ignition, and species formation.

  4. Recent Developments in No-Core Shell-Model Calculations

    SciTech Connect (OSTI)

    Navratil, P; Quaglioni, S; Stetcu, I; Barrett, B R

    2009-03-20

    We present an overview of recent results and developments of the no-core shell model (NCSM), an ab initio approach to the nuclear many-body problem for light nuclei. In this aproach, we start from realistic two-nucleon or two- plus three-nucleon interactions. Many-body calculations are performed using a finite harmonic-oscillator (HO) basis. To facilitate convergence for realistic inter-nucleon interactions that generate strong short-range correlations, we derive effective interactions by unitary transformations that are tailored to the HO basis truncation. For soft realistic interactions this might not be necessary. If that is the case, the NCSM calculations are variational. In either case, the ab initio NCSM preserves translational invariance of the nuclear many-body problem. In this review, we, in particular, highlight results obtained with the chiral two- plus three-nucleon interactions. We discuss efforts to extend the applicability of the NCSM to heavier nuclei and larger model spaces using importance-truncation schemes and/or use of effective interactions with a core. We outline an extension of the ab initio NCSM to the description of nuclear reactions by the resonating group method technique. A future direction of the approach, the ab initio NCSM with continuum, which will provide a complete description of nuclei as open systems with coupling of bound and continuum states is given in the concluding part of the review.

  5. Core melt/coolant interactions: modelling. [PWR; BWR

    SciTech Connect (OSTI)

    Berman, M.; McGlaun, J.M.; Corradini, M.L.

    1983-01-01

    If there is not adequate cooling water in the core of a light-water reactor (LWR), the fission product decay heat would eventually cause the reactor fuel and cladding to melt. This could lead to slumping of the molten core materials into the lower plenum of the reactor vessel, possibly followed by failure of the vessel wall and pouring of the molten materials into the reactor cavity. When the molten core materials enter either region, there is a strong possibility of molten core contacting water. This paper focuses on analysis of recent FITS experiments, mechanistic and probabilistic model development, and the application of these models to reactor considerations.

  6. SCDAP/RELAP5 Lower Core Plate Model

    SciTech Connect (OSTI)

    Coryell, Eric Wesley; Griffin, F. P.

    1999-10-01

    The SCDAP/RELAP5 computer code is a best-estimate analysis tool for performing nuclear reactor severe accident simulations. This report describes the justification, theory, implementation, and testing of a new modeling capability which will refine the analysis of the movement of molten material from the core region to the vessel lower head. As molten material moves from the core region through the core support structures it may encounter conditions which will cause it to freeze in the region of the lower core plate, delaying its arrival to the vessel head. The timing of this arrival is significant to reactor safety, because during the time span for material relocation to the lower head, the core may be experiencing steam-limited oxidation. The time at which hot material arrives in a coolant-filled lower vessel head, thereby significantly increasing the steam flow rate through the core region, becomes significant to the progression and timing of a severe accident. This report is a revision of a report INEEL/EXT-00707, entitled "Preliminary Design Report for SCDAP/RELAP5 Lower Core Plate Model".

  7. SCDAP/RELAP5 lower core plate model

    SciTech Connect (OSTI)

    Coryell, E.W.; Griffin, F.P.

    1999-09-01

    The SCDAP/RELAP5 computer code is a best-estimate analysis tool for performing nuclear reactor severe accident simulations. This report describes the justification, theory, implementation, and testing of a new modeling capability which will refine the analysis of the movement of molten material from the core region to the vessel lower head. As molten material moves from the core region through the core support structures it may encounter conditions which will cause it to freeze in the region of the lower core plate, delaying its arrival to the vessel head. The timing of this arrival is significant to reactor safety, because during the time span for material relocation to the lower head, the core may be experiencing steam-limited oxidation. The time at which hot material arrives in a coolant-filled lower vessel head, thereby significantly increasing the steam flow rate through the core region, becomes significant to the progression and timing of a severe accident. This report is a revision of a report INEEL/EXT-00707, entitled ``Preliminary Design Report for SCDAP/RELAP5 Lower Core Plate Model''.

  8. Summary of multi-core hardware and programming model investigations

    SciTech Connect (OSTI)

    Kelly, Suzanne Marie; Pedretti, Kevin Thomas Tauke; Levenhagen, Michael J.

    2008-05-01

    This report summarizes our investigations into multi-core processors and programming models for parallel scientific applications. The motivation for this study was to better understand the landscape of multi-core hardware, future trends, and the implications on system software for capability supercomputers. The results of this study are being used as input into the design of a new open-source light-weight kernel operating system being targeted at future capability supercomputers made up of multi-core processors. A goal of this effort is to create an agile system that is able to adapt to and efficiently support whatever multi-core hardware and programming models gain acceptance by the community.

  9. Simulating High Flux Isotope Reactor Core Thermal-Hydraulics via Interdimensional Model Coupling

    SciTech Connect (OSTI)

    Travis, Adam R

    2014-05-01

    A coupled interdimensional model is presented for the simulation of the thermal-hydraulic characteristics of the High Flux Isotope Reactor core at Oak Ridge National Laboratory. The model consists of two domains a solid involute fuel plate and the surrounding liquid coolant channel. The fuel plate is modeled explicitly in three-dimensions. The coolant channel is approximated as a twodimensional slice oriented perpendicular to the fuel plate s surface. The two dimensionally-inconsistent domains are linked to one another via interdimensional model coupling mechanisms. The coupled model is presented as a simplified alternative to a fully explicit, fully three-dimensional model. Involute geometries were constructed in SolidWorks. Derivations of the involute construction equations are presented. Geometries were then imported into COMSOL Multiphysics for simulation and modeling. Both models are described in detail so as to highlight their respective attributes in the 3D model, the pursuit of an accurate, reliable, and complete solution; in the coupled model, the intent to simplify the modeling domain as much as possible without affecting significant alterations to the solution. The coupled model was created with the goal of permitting larger portions of the reactor core to be modeled at once without a significant sacrifice to solution integrity. As such, particular care is given to validating incorporated model simplifications. To the greatest extent possible, the decrease in solution time as well as computational cost are quantified versus the effects such gains have on the solution quality. A variant of the coupled model which sufficiently balances these three solution characteristics is presented alongside the more comprehensive 3D model for comparison and validation.

  10. Development of a land ice core for the Model for Prediction Across...

    Office of Scientific and Technical Information (OSTI)

    Conference: Development of a land ice core for the Model for Prediction Across Scales (MPAS) Citation Details In-Document Search Title: Development of a land ice core for the Model ...

  11. TWO-DIMENSIONAL CORE-COLLAPSE SUPERNOVA MODELS WITH MULTI-DIMENSIONAL

    Office of Scientific and Technical Information (OSTI)

    TRANSPORT (Journal Article) | SciTech Connect TWO-DIMENSIONAL CORE-COLLAPSE SUPERNOVA MODELS WITH MULTI-DIMENSIONAL TRANSPORT Citation Details In-Document Search Title: TWO-DIMENSIONAL CORE-COLLAPSE SUPERNOVA MODELS WITH MULTI-DIMENSIONAL TRANSPORT We present new two-dimensional (2D) axisymmetric neutrino radiation/hydrodynamic models of core-collapse supernova (CCSN) cores. We use the CASTRO code, which incorporates truly multi-dimensional, multi-group, flux-limited diffusion (MGFLD)

  12. Advanced Test Reactor Core Modeling Update Project Annual Report for Fiscal Year 2011

    SciTech Connect (OSTI)

    David W. Nigg; Devin A. Steuhm

    2011-09-01

    Legacy computational reactor physics software tools and protocols currently used for support of Advanced Test Reactor (ATR) core fuel management and safety assurance and, to some extent, experiment management are obsolete, inconsistent with the state of modern nuclear engineering practice, and are becoming increasingly difficult to properly verify and validate (V&V). Furthermore, the legacy staff knowledge required for application of these tools and protocols from the 1960s and 1970s is rapidly being lost due to staff turnover and retirements. In 2009 the Idaho National Laboratory (INL) initiated a focused effort to address this situation through the introduction of modern high-fidelity computational software and protocols, with appropriate V&V, within the next 3-4 years via the ATR Core Modeling and Simulation and V&V Update (or 'Core Modeling Update') Project. This aggressive computational and experimental campaign will have a broad strategic impact on the operation of the ATR, both in terms of improved computational efficiency and accuracy for support of ongoing DOE programs as well as in terms of national and international recognition of the ATR National Scientific User Facility (NSUF). The ATR Core Modeling Update Project, targeted for full implementation in phase with the anticipated ATR Core Internals Changeout (CIC) in the 2014 time frame, began during the last quarter of Fiscal Year 2009, and has just completed its first full year. Key accomplishments so far have encompassed both computational as well as experimental work. A new suite of stochastic and deterministic transport theory based reactor physics codes and their supporting nuclear data libraries (SCALE, KENO-6, HELIOS, NEWT, and ATTILA) have been installed at the INL under various permanent sitewide license agreements and corresponding baseline models of the ATR and ATRC are now operational, demonstrating the basic feasibility of these code packages for their intended purpose. Furthermore, a capability for rigorous sensitivity analysis and uncertainty quantification based on the TSUNAMI system is being implemented and initial computational results have been obtained. This capability will have many applications in 2011 and beyond as a tool for understanding the margins of uncertainty in the new models as well as for validation experiment design and interpretation. Finally we note that although full implementation of the new computational models and protocols will extend over a period 3-4 years as noted above, interim applications in the much nearer term have already been demonstrated. In particular, these demonstrations included an analysis that was useful for understanding the cause of some issues in December 2009 that were triggered by a larger than acceptable discrepancy between the measured excess core reactivity and a calculated value that was based on the legacy computational methods. As the Modeling Update project proceeds we anticipate further such interim, informal, applications in parallel with formal qualification of the system under the applicable INL Quality Assurance procedures and standards.

  13. Development of COBRA-TF for Modeling Full-Core Reactor Operating Cycles

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Development of COBRA-TF for Modeling Full-Core Reactor Operating Cycles Citation Details In-Document Search Title: Development of COBRA-TF for Modeling Full-Core Reactor Operating Cycles Authors: Salko, Robert K [1] ; Lange, Travis L [1] ; Kucukboyaci, Vefa [2] ; Sung, Yixing [2] ; Palmtag, Scott [3] ; Gehin, Jess C [1] ; Avramova, Maria [4] + Show Author Affiliations ORNL Westinghouse Electric Company, Cranberry Township Core Physics, Inc. Pennsylvania State

  14. Development of a land ice core for the Model for Prediction Across...

    Office of Scientific and Technical Information (OSTI)

    for the Model for Prediction Across Scales (MPAS) Citation Details In-Document Search Title: Development of a land ice core for the Model for Prediction Across Scales (MPAS) No ...

  15. Development of a land ice core for the Model for Prediction Across...

    Office of Scientific and Technical Information (OSTI)

    for the Model for Prediction Across Scales (MPAS) Citation Details In-Document Search Title: Development of a land ice core for the Model for Prediction Across Scales (MPAS) ...

  16. Continuously Optimized Reliable Energy (CORE) Microgrid: Models & Tools (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-07-01

    This brochure describes Continuously Optimized Reliable Energy (CORE), a trademarked process NREL employs to produce conceptual microgrid designs. This systems-based process enables designs to be optimized for economic value, energy surety, and sustainability. Capabilities NREL offers in support of microgrid design are explained.

  17. Ab Initio Study of 40Ca with an Importance Truncated No-Core Shell Model

    SciTech Connect (OSTI)

    Roth, R; Navratil, P

    2007-05-22

    We propose an importance truncation scheme for the no-core shell model, which enables converged calculations for nuclei well beyond the p-shell. It is based on an a priori measure for the importance of individual basis states constructed by means of many-body perturbation theory. Only the physically relevant states of the no-core model space are considered, which leads to a dramatic reduction of the basis dimension. We analyze the validity and efficiency of this truncation scheme using different realistic nucleon-nucleon interactions and compare to conventional no-core shell model calculations for {sup 4}He and {sup 16}O. Then, we present the first converged calculations for the ground state of {sup 40}Ca within no-core model spaces including up to 16{h_bar}{Omega}-excitations using realistic low-momentum interactions. The scheme is universal and can be easily applied to other quantum many-body problems.

  18. Development of COBRA-TF for Modeling Full-Core Reactor Operating...

    Office of Scientific and Technical Information (OSTI)

    Title: Development of COBRA-TF for Modeling Full-Core Reactor Operating Cycles Authors: Salko, Robert K 1 ; Lange, Travis L 1 ; Kucukboyaci, Vefa 2 ; Sung, Yixing 2 ; ...

  19. Electric Dipole Transitions Within The Ab initio No-Core Shell Model With

    Office of Scientific and Technical Information (OSTI)

    Continuum (Technical Report) | SciTech Connect Technical Report: Electric Dipole Transitions Within The Ab initio No-Core Shell Model With Continuum Citation Details In-Document Search Title: Electric Dipole Transitions Within The Ab initio No-Core Shell Model With Continuum Authors: Quaglioni, S ; Baroni, S ; Navratil, P Publication Date: 2012-10-01 OSTI Identifier: 1053666 Report Number(s): LLNL-TR-588973 DOE Contract Number: W-7405-ENG-48 Resource Type: Technical Report Research Org:

  20. Modeling of the Reactor Core Isolation Cooling Response to Beyond Design Basis Operations - Interim Report

    SciTech Connect (OSTI)

    Ross, Kyle; Cardoni, Jeffrey N.; Wilson, Chisom Shawn; Morrow, Charles; Osborn, Douglas; Gauntt, Randall O.

    2015-12-01

    Efforts are being pursued to develop and qualify a system-level model of a reactor core isolation (RCIC) steam-turbine-driven pump. The model is being developed with the intent of employing it to inform the design of experimental configurations for full-scale RCIC testing. The model is expected to be especially valuable in sizing equipment needed in the testing. An additional intent is to use the model in understanding more fully how RCIC apparently managed to operate far removed from its design envelope in the Fukushima Daiichi Unit 2 accident. RCIC modeling is proceeding along two avenues that are expected to complement each other well. The first avenue is the continued development of the system-level RCIC model that will serve in simulating a full reactor system or full experimental configuration of which a RCIC system is part. The model reasonably represents a RCIC system today, especially given design operating conditions, but lacks specifics that are likely important in representing the off-design conditions a RCIC system might experience in an emergency situation such as a loss of all electrical power. A known specific lacking in the system model, for example, is the efficiency at which a flashing slug of water (as opposed to a concentrated jet of steam) could propel the rotating drive wheel of a RCIC turbine. To address this specific, the second avenue is being pursued wherein computational fluid dynamics (CFD) analyses of such a jet are being carried out. The results of the CFD analyses will thus complement and inform the system modeling. The system modeling will, in turn, complement the CFD analysis by providing the system information needed to impose appropriate boundary conditions on the CFD simulations. The system model will be used to inform the selection of configurations and equipment best suitable of supporting planned RCIC experimental testing. Preliminary investigations with the RCIC model indicate that liquid water ingestion by the turbine decreases the developed turbine torque; the RCIC speed then slows, and thus the pump flow rate to the RPV decreases. Subsequently, RPV water level decreases due to continued boiling and the liquid fraction flowing to the RCIC decreases, thereby accelerating the RCIC and refilling the RPV. The feedback cycle then repeats itself and/or reaches a quasi-steady equilibrium condition. In other words, the water carry-over is limited by cyclic RCIC performance degradation, and hence the system becomes self-regulating. The indications achieved to date with the system model are more qualitative than quantitative. The avenues being pursued to increase the fidelity of the model are expected to add quantitative realism. The end product will be generic in the sense that the RCIC model will be incorporable within the larger reactor coolant system model of any nuclear power plant or experimental configuration.

  1. Structure and thermodynamics of core-softened models for alcohols

    SciTech Connect (OSTI)

    Munaò, Gianmarco; Urbic, Tomaz

    2015-06-07

    The phase behavior and the fluid structure of coarse-grain models for alcohols are studied by means of reference interaction site model (RISM) theory and Monte Carlo simulations. Specifically, we model ethanol and 1-propanol as linear rigid chains constituted by three (trimers) and four (tetramers) partially fused spheres, respectively. Thermodynamic properties of these models are examined in the RISM context, by employing closed formulæ for the calculation of free energy and pressure. Gas-liquid coexistence curves for trimers and tetramers are reported and compared with already existing data for a dimer model of methanol. Critical temperatures slightly increase with the number of CH{sub 2} groups in the chain, while critical pressures and densities decrease. Such a behavior qualitatively reproduces the trend observed in experiments on methanol, ethanol, and 1-propanol and suggests that our coarse-grain models, despite their simplicity, can reproduce the essential features of the phase behavior of such alcohols. The fluid structure of these models is investigated by computing radial distribution function g{sub ij}(r) and static structure factor S{sub ij}(k); the latter shows the presence of a low−k peak at intermediate-high packing fractions and low temperatures, suggesting the presence of aggregates for both trimers and tetramers.

  2. State space modeling of reactor core in a pressurized water reactor

    SciTech Connect (OSTI)

    Ashaari, A.; Ahmad, T.; M, Wan Munirah W.; Shamsuddin, Mustaffa; Abdullah, M. Adib

    2014-07-10

    The power control system of a nuclear reactor is the key system that ensures a safe operation for a nuclear power plant. However, a mathematical model of a nuclear power plant is in the form of nonlinear process and time dependent that give very hard to be described. One of the important components of a Pressurized Water Reactor is the Reactor core. The aim of this study is to analyze the performance of power produced from a reactor core using temperature of the moderator as an input. Mathematical representation of the state space model of the reactor core control system is presented and analyzed in this paper. The data and parameters are taken from a real time VVER-type Pressurized Water Reactor and will be verified using Matlab and Simulink. Based on the simulation conducted, the results show that the temperature of the moderator plays an important role in determining the power of reactor core.

  3. Ex-Vessel Core Melt Modeling Comparison between MELTSPREAD-CORQUENCH and MELCOR 2.1

    SciTech Connect (OSTI)

    Robb, Kevin R.; Farmer, Mitchell; Francis, Matthew W.

    2014-03-01

    System-level code analyses by both United States and international researchers predict major core melting, bottom head failure, and corium-concrete interaction for Fukushima Daiichi Unit 1 (1F1). Although system codes such as MELCOR and MAAP are capable of capturing a wide range of accident phenomena, they currently do not contain detailed models for evaluating some ex-vessel core melt behavior. However, specialized codes containing more detailed modeling are available for melt spreading such as MELTSPREAD as well as long-term molten corium-concrete interaction (MCCI) and debris coolability such as CORQUENCH. In a preceding study, Enhanced Ex-Vessel Analysis for Fukushima Daiichi Unit 1: Melt Spreading and Core-Concrete Interaction Analyses with MELTSPREAD and CORQUENCH, the MELTSPREAD-CORQUENCH codes predicted the 1F1 core melt readily cooled in contrast to predictions by MELCOR. The user community has taken notice and is in the process of updating their systems codes; specifically MAAP and MELCOR, to improve and reduce conservatism in their ex-vessel core melt models. This report investigates why the MELCOR v2.1 code, compared to the MELTSPREAD and CORQUENCH 3.03 codes, yield differing predictions of ex-vessel melt progression. To accomplish this, the differences in the treatment of the ex-vessel melt with respect to melt spreading and long-term coolability are examined. The differences in modeling approaches are summarized, and a comparison of example code predictions is provided.

  4. Neutronics modeling of the SPERT III E-Core critical experiments with MPACT

    Office of Scientific and Technical Information (OSTI)

    and KENO (Journal Article) | SciTech Connect Neutronics modeling of the SPERT III E-Core critical experiments with MPACT and KENO Citation Details In-Document Search This content will become publicly available on May 28, 2017 Title: Neutronics modeling of the SPERT III E-Core critical experiments with MPACT and KENO Authors: Cao, Liangzhi Search SciTech Connect for author "Cao, Liangzhi" Search SciTech Connect for ORCID "000000022872011X" Search orcid.org for ORCID

  5. No-Core Shell Model Analysis Of Light Nuclei (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Conference: No-Core Shell Model Analysis Of Light Nuclei Citation Details In-Document Search Title: No-Core Shell Model Analysis Of Light Nuclei Authors: Quaglioni, S ; Navratil, P ; Hupin, G ; Langhammee, J ; Romero-Redondo, C ; Roth, R Publication Date: 2012-09-24 OSTI Identifier: 1053647 Report Number(s): LLNL-PROC-586292 DOE Contract Number: W-7405-ENG-48 Resource Type: Conference Resource Relation: Conference: Presented at: 20th International IUPAP Conference on Few-Body Problems in Physics

  6. No-Core Shell Model Analysis Of Light Nuclei (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Conference: No-Core Shell Model Analysis Of Light Nuclei Citation Details In-Document Search Title: No-Core Shell Model Analysis Of Light Nuclei × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in energy science and technology. A paper copy of this document is also available for sale

  7. Development of a land ice core for the Model for Prediction Across Scales

    Office of Scientific and Technical Information (OSTI)

    (MPAS) (Conference) | SciTech Connect of a land ice core for the Model for Prediction Across Scales (MPAS) Citation Details In-Document Search Title: Development of a land ice core for the Model for Prediction Across Scales (MPAS) No abstract prepared. Authors: Hoffman, Matthew J [1] + Show Author Affiliations Los Alamos National Laboratory Publication Date: 2012-06-25 OSTI Identifier: 1044843 Report Number(s): LA-UR-12-22469 TRN: US201214%%525 DOE Contract Number: AC52-06NA25396 Resource

  8. Upscaling of the waterflood reservoir properties on the core level: Laboratory study, macro and micro modelling

    SciTech Connect (OSTI)

    Bedrikovetsky, P.G.; Polyanin, A.D.; Zhurov, A.I.; Potsch, K.T.

    1995-10-01

    The aim of the paper is to develop a mathematical model for waterflooding at high velocities in short cores under laboratory conditions. The model is based on the theory of non-equilibrium two-phase flow in a porous medium. The asymptotic solution includes the capillary pressure and non-equilibrium effects. It allows for determining an expression for he stabilized zone, which leads to an optimal core length and an optimal displacement velocity. With these parameters it is possible to plan waterflooding tests for determining the relative phase permeabilities with a given accuracy.

  9. Investigation of approximations in thermal-hydraulic modeling of core conversions

    SciTech Connect (OSTI)

    Garner, Patrick L.; Hanan, Nelson A.

    2008-07-15

    Neutronics analyses for core conversions are usually fairly detailed, for example representing all 4 flats and all 4 corners of all 6 tubes of all 20 IRT-3M or -4M fuel assemblies in the core of the VVR-SM reactor in Uzbekistan. The coupled neutronics and thermal-hydraulic analysis for safety analysis transients is usually less detailed, for example modeling only a hot and an average fuel plate and the associated coolant. Several of the approximations have been studied using the RELAP5 and PARET computer codes in order to provide assurance that the lack of full detail is not important to the safety analysis. Two specific cases studied are (1) representation of a core of same- type fuel assemblies by a hot and an average assembly each having multiple channels as well as by merely a hot and average channel and (2) modeling a core containing multiple fuel types as the sum of fractional core models for each fuel type. (author)

  10. Development of high frequency spice models for ferrite core inductors and transformers

    SciTech Connect (OSTI)

    Muyshondt, G.P.; Portnoy, W.M. . Dept. of Electrical Engineering)

    1989-01-01

    In this work high frequency SPICE models were developed to simulate the hysteresis and saturation effects of toroidal shaped ferrite core inductors and transformers. The models include the nonlinear, multi-valued B-H characteristic of the core material, leakage flux, stray capacitances, and core losses. The saturation effects were modeled using two diode clamping arrangements in conjunction with nonlinear dependent sources. Two possible controlling schemes were developed for the saturation switch. One of the arrangements used the current flowing through a series RC branch to control the switch, while the other used a NAND gate. The NAND gate implementation of the switch proved to be simpler and the parameters associated with it were easier to determine from the measurements and the B-H characteristics of the material. Lumped parameters were used to simulate the parasitic effects. Techniques for measuring these parasitic are described. The models were verified using manganese-zinc ferrite-type toroidal cores and they have general applicability to all circuit analysis codes equivalent function blocks such as multipliers, adders, and logic components. 7 refs., 22 figs.

  11. Scientists detect methane levels three times larger than expected...

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

    Methane levels larger over Four Corners region Scientists detect methane levels three times larger than expected over Four Corners region Study is first to show space-based...

  12. Upcoming Funding Opportunity to Develop Larger Wind Turbine Blades...

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

    Upcoming Funding Opportunity to Develop Larger Wind Turbine Blades Upcoming Funding Opportunity to Develop Larger Wind Turbine Blades February 20, 2015 - 4:55pm Addthis On February...

  13. Failure Predictions for VHTR Core Components using a Probabilistic Contiuum Damage Mechanics Model

    SciTech Connect (OSTI)

    Fok, Alex

    2013-10-30

    The proposed work addresses the key research need for the development of constitutive models and overall failure models for graphite and high temperature structural materials, with the long-term goal being to maximize the design life of the Next Generation Nuclear Plant (NGNP). To this end, the capability of a Continuum Damage Mechanics (CDM) model, which has been used successfully for modeling fracture of virgin graphite, will be extended as a predictive and design tool for the core components of the very high- temperature reactor (VHTR). Specifically, irradiation and environmental effects pertinent to the VHTR will be incorporated into the model to allow fracture of graphite and ceramic components under in-reactor conditions to be modeled explicitly using the finite element method. The model uses a combined stress-based and fracture mechanics-based failure criterion, so it can simulate both the initiation and propagation of cracks. Modern imaging techniques, such as x-ray computed tomography and digital image correlation, will be used during material testing to help define the baseline material damage parameters. Monte Carlo analysis will be performed to address inherent variations in material properties, the aim being to reduce the arbitrariness and uncertainties associated with the current statistical approach. The results can potentially contribute to the current development of American Society of Mechanical Engineers (ASME) codes for the design and construction of VHTR core components.

  14. NUMERICAL VERIFICATION OF THE RELAP-7 CORE CHANNEL SINGLE-PHASE MODEL

    SciTech Connect (OSTI)

    Haihua Zhao; Ling Zou; Hongbin Zhang; Richard Martineau

    2014-06-01

    The RELAP-7 code is the next generation of nuclear reactor system safety analysis code being developed at the Idaho National Laboratory (INL). All the physics in RELAP-7 are fully coupled and the errors resulted from the traditional operator-splitting approach are eliminated. By using 2nd order methods in both time and space and eliminating operator-splitting errors, the numerical error of RELAP-7 can be minimized. Numerical verification is the process to verify the orders of numerical methods. It is an important part of modern verification and validation process. The core channel component in RELAP-7 is designed to simulate coolant flow as well as the conjugated heat transfer between coolant flow and the fuel rod. A special treatment at fuel centerline to avoid numerical singularity for the cylindrical heat conduction in the continuous finite element mesh is discussed. One steady state test case and one fast power up transient test case are utilized for the verification of the core channel model with single-phase flow. Analytical solution for the fuel pin temperature and figures of merit such as peak clad temperature and peak fuel temperature are used to define numerical errors. These cases prove that the mass and energy are well conserved and 2nd order convergence rates for both time and space are achieved in the core channel model.

  15. TRACE/PARCS Core Modeling of a BWR/5 for Accident Analysis of ATWS Events

    SciTech Connect (OSTI)

    Cuadra A.; Baek J.; Cheng, L.; Aronson, A.; Diamond, D.; Yarsky, P.

    2013-11-10

    The TRACE/PARCS computational package [1, 2] isdesigned to be applicable to the analysis of light water reactor operational transients and accidents where the coupling between the neutron kinetics (PARCS) and the thermal-hydraulics and thermal-mechanics (TRACE) is important. TRACE/PARCS has been assessed for itsapplicability to anticipated transients without scram(ATWS) [3]. The challenge, addressed in this study, is to develop a sufficiently rigorous input model that would be acceptable for use in ATWS analysis. Two types of ATWS events were of interest, a turbine trip and a closure of main steam isolation valves (MSIVs). In the first type, initiated by turbine trip, the concern is that the core will become unstable and large power oscillations will occur. In the second type,initiated by MSIV closure,, the concern is the amount of energy being placed into containment and the resulting emergency depressurization. Two separate TRACE/PARCS models of a BWR/5 were developed to analyze these ATWS events at MELLLA+ (maximum extended load line limit plus)operating conditions. One model [4] was used for analysis of ATWS events leading to instability (ATWS-I);the other [5] for ATWS events leading to emergency depressurization (ATWS-ED). Both models included a large portion of the nuclear steam supply system and controls, and a detailed core model, presented henceforth.

  16. Modeling of BWR core meltdown accidents - for application in the MELRPI. MOD2 computer code

    SciTech Connect (OSTI)

    Koh, B R; Kim, S H; Taleyarkhan, R P; Podowski, M Z; Lahey, Jr, R T

    1985-04-01

    This report summarizes improvements and modifications made in the MELRPI computer code. A major difference between this new, updated version of the code, called MELRPI.MOD2, and the one reported previously, concerns the inclusion of a model for the BWR emergency core cooling systems (ECCS). This model and its computer implementation, the ECCRPI subroutine, account for various emergency injection modes, for both intact and rubblized geometries. Other changes to MELRPI deal with an improved model for canister wall oxidation, rubble bed modeling, and numerical integration of system equations. A complete documentation of the entire MELRPI.MOD2 code is also given, including an input guide, list of subroutines, sample input/output and program listing.

  17. A moist aquaplanet variant of the HeldSuarez test for atmospheric model dynamical cores

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

    Thatcher, D. R.; Jablonowski, C.

    2015-09-29

    A moist idealized test case (MITC) for atmospheric model dynamical cores is presented. The MITC is based on the HeldSuarez (HS) test that was developed for dry simulations on a flat Earth and replaces the full physical parameterization package with a Newtonian temperature relaxation and Rayleigh damping of the low-level winds. This new variant of the HS test includes moisture and thereby sheds light on the non-linear dynamics-physics moisture feedbacks without the complexity of full physics parameterization packages. In particular, it adds simplified moist processes to the HS forcing to model large-scale condensation, boundary layer mixing, and the exchange ofmorelatent and sensible heat between the atmospheric surface and an ocean-covered planet. Using a variety of dynamical cores of NCAR's Community Atmosphere Model (CAM), this paper demonstrates that the inclusion of the moist idealized physics package leads to climatic states that closely resemble aquaplanet simulations with complex physical parameterizations. This establishes that the MITC approach generates reasonable atmospheric circulations and can be used for a broad range of scientific investigations. This paper provides examples of two application areas. First, the test case reveals the characteristics of the physics-dynamics coupling technique and reproduces coupling issues seen in full-physics simulations. In particular, it is shown that sudden adjustments of the prognostic fields due to moist physics tendencies can trigger undesirable large-scale gravity waves, which can be remedied by a more gradual application of the physical forcing. Second, the moist idealized test case can be used to intercompare dynamical cores. These examples demonstrate the versatility of the MITC approach and suggestions are made for further application areas. The new moist variant of the HS test can be considered a test case of intermediate complexity.less

  18. Modeling Stress Strain Relationships and Predicting Failure Probabilities For Graphite Core Components

    SciTech Connect (OSTI)

    Duffy, Stephen

    2013-09-09

    This project will implement inelastic constitutive models that will yield the requisite stress-strain information necessary for graphite component design. Accurate knowledge of stress states (both elastic and inelastic) is required to assess how close a nuclear core component is to failure. Strain states are needed to assess deformations in order to ascertain serviceability issues relating to failure, e.g., whether too much shrinkage has taken place for the core to function properly. Failure probabilities, as opposed to safety factors, are required in order to capture the bariability in failure strength in tensile regimes. The current stress state is used to predict the probability of failure. Stochastic failure models will be developed that can accommodate possible material anisotropy. This work will also model material damage (i.e., degradation of mechanical properties) due to radiation exposure. The team will design tools for components fabricated from nuclear graphite. These tools must readily interact with finite element software--in particular, COMSOL, the software algorithm currently being utilized by the Idaho National Laboratory. For the eleastic response of graphite, the team will adopt anisotropic stress-strain relationships available in COMSO. Data from the literature will be utilized to characterize the appropriate elastic material constants.

  19. Inference of ICF implosion core mix using experimental data and theoretical mix modeling

    SciTech Connect (OSTI)

    Sherrill, Leslie Welser; Haynes, Donald A; Cooley, James H; Sherrill, Manolo E; Mancini, Roberto C; Tommasini, Riccardo; Golovkin, Igor E; Haan, Steven W

    2009-01-01

    The mixing between fuel and shell materials in Inertial Confinement Fusion (lCF) implosion cores is a current topic of interest. The goal of this work was to design direct-drive ICF experiments which have varying levels of mix, and subsequently to extract information on mixing directly from the experimental data using spectroscopic techniques. The experimental design was accomplished using hydrodynamic simulations in conjunction with Haan's saturation model, which was used to predict the mix levels of candidate experimental configurations. These theoretical predictions were then compared to the mixing information which was extracted from the experimental data, and it was found that Haan's mix model predicted trends in the width of the mix layer as a function of initial shell thickness. These results contribute to an assessment of the range of validity and predictive capability of the Haan saturation model, as well as increasing confidence in the methods used to extract mixing information from experimental data.

  20. Advanced Test Reactor Core Modeling Update Project Annual Report for Fiscal Year 2012

    SciTech Connect (OSTI)

    David W. Nigg, Principal Investigator; Kevin A. Steuhm, Project Manager

    2012-09-01

    Legacy computational reactor physics software tools and protocols currently used for support of Advanced Test Reactor (ATR) core fuel management and safety assurance, and to some extent, experiment management, are inconsistent with the state of modern nuclear engineering practice, and are difficult, if not impossible, to properly verify and validate (V&V) according to modern standards. Furthermore, the legacy staff knowledge required for application of these tools and protocols from the 1960s and 1970s is rapidly being lost due to staff turnover and retirements. In late 2009, the Idaho National Laboratory (INL) initiated a focused effort, the ATR Core Modeling Update Project, to address this situation through the introduction of modern high-fidelity computational software and protocols. This aggressive computational and experimental campaign will have a broad strategic impact on the operation of the ATR, both in terms of improved computational efficiency and accuracy for support of ongoing DOE programs as well as in terms of national and international recognition of the ATR National Scientific User Facility (NSUF). The ATR Core Modeling Update Project, targeted for full implementation in phase with the next anticipated ATR Core Internals Changeout (CIC) in the 2014-2015 time frame, began during the last quarter of Fiscal Year 2009, and has just completed its third full year. Key accomplishments so far have encompassed both computational as well as experimental work. A new suite of stochastic and deterministic transport theory based reactor physics codes and their supporting nuclear data libraries (HELIOS, KENO6/SCALE, NEWT/SCALE, ATTILA, and an extended implementation of MCNP5) has been installed at the INL under various licensing arrangements. Corresponding models of the ATR and ATRC are now operational with all five codes, demonstrating the basic feasibility of the new code packages for their intended purpose. Of particular importance, a set of as-run core depletion HELIOS calculations for all ATR cycles since August 2009, Cycle 145A through Cycle 151B, was successfully completed during 2012. This major effort supported a decision late in the year to proceed with the phased incorporation of the HELIOS methodology into the ATR Core Safety Analysis Package (CSAP) preparation process, in parallel with the established PDQ-based methodology, beginning late in Fiscal Year 2012. Acquisition of the advanced SERPENT (VTT-Finland) and MC21 (DOE-NR) Monte Carlo stochastic neutronics simulation codes was also initiated during the year and some initial applications of SERPENT to ATRC experiment analysis were demonstrated. These two new codes will offer significant additional capability, including the possibility of full-3D Monte Carlo fuel management support capabilities for the ATR at some point in the future. Finally, a capability for rigorous sensitivity analysis and uncertainty quantification based on the TSUNAMI system has been implemented and initial computational results have been obtained. This capability will have many applications as a tool for understanding the margins of uncertainty in the new models as well as for validation experiment design and interpretation.

  1. New Report Shows Trend Toward Larger Offshore Wind Systems, with...

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

    Report Shows Trend Toward Larger Offshore Wind Systems, with 11 Advanced Stage Projects ... in offshore wind farms, increasing the amount of electricity delivered to consumers. ...

  2. Generic disposal concepts and thermal load management for larger...

    Office of Scientific and Technical Information (OSTI)

    Generic disposal concepts and thermal load management for larger waste packages. Citation Details In-Document Search Title: Generic disposal concepts and thermal load management...

  3. Effect of a detailed radial core expansion reactivity feedback model on ATWS calculations using SASSYS/SAS4A

    SciTech Connect (OSTI)

    Wigeland, R.A.

    1986-01-01

    The present emphasis on inherent safety and inherently safe designs for liquid-metal reactors has resulted in a need to represent the various reactivity feedback mechanisms as accurately as possible. In particular, the reactivity feedback from radial core expansion has been found to provide the dominant negative feedback contribution in postulated anticipated transient without scram (ATWS) events. Review of the existing modeling in the SASSYS/SAS4A computer code system revealed that while the modeling may be adequate for the early phases of various unprotected transients, the accuracy would be less than desirable for the extended transients which typically occur for inherently safe designs. The existing model for calculating the reactivity feedback from radial core expansion uses a feedback from radial core expansion uses a feedback coefficient in conjunction with changes in the temperatures of the grid support plate and the above-core load pad. The accuracy of this approach is determined partly by the conditions used in deriving the feedback coefficient, and their relevance to the transient being investigated. Accuracy is also affected by the need to include effects other than those that could be directly related to changes in the grid plate and above-core load pad temperatures, such as subassembly bowing and the potential for clearances to occur between subassemblies in the above-core load pad region. As a result, a detailed model was developed in an attempt to account for these and other effects in a more mechanistic form.

  4. Advanced Test Reactor Core Modeling Update Project Annual Report for Fiscal Year 2013

    SciTech Connect (OSTI)

    David W. Nigg

    2013-09-01

    Legacy computational reactor physics software tools and protocols currently used for support of Advanced Test Reactor (ATR) core fuel management and safety assurance, and to some extent, experiment management, are inconsistent with the state of modern nuclear engineering practice, and are difficult, if not impossible, to verify and validate (V&V) according to modern standards. Furthermore, the legacy staff knowledge required for effective application of these tools and protocols from the 1960s and 1970s is rapidly being lost due to staff turnover and retirements. In late 2009, the Idaho National Laboratory (INL) initiated a focused effort, the ATR Core Modeling Update Project, to address this situation through the introduction of modern high-fidelity computational software and protocols. This aggressive computational and experimental campaign will have a broad strategic impact on the operation of the ATR, both in terms of improved computational efficiency and accuracy for support of ongoing DOE programs as well as in terms of national and international recognition of the ATR National Scientific User Facility (NSUF).

  5. Origin of Macrostrains and Microstrains in Daimond-SiC Nanocomposites Based on the Core-shell Model

    SciTech Connect (OSTI)

    Palosz,B.; Stelmakh, S.; Grzanka, E.; Gierlotka, S.; Nauyoks, S.; Zerda, T.; Palosz, W.

    2007-01-01

    SiC-diamond nanocomposites were synthesized from nanodiamond and nanosilicon powders. A core-shell model of the composite nanocrystals was examined assuming that interatomic distances in the grain interior, the core, and at the surface shell (grain boundaries in nanocrystalline solids) are different. The samples were investigated by x-ray diffraction using synchrotron source. The powder diffractograms were elaborated based on the apparent lattice parameter methodology. The structure of the composites and its dependence on the sintering conditions is discussed. It is shown that as the sintering temperature increases the interatomic distances in the grain cores decrease, while the opposite occurs in the grain shells (forming the grain boundaries). Under some sintering temperature the interatomic distances in the core and in the shell get equal. However, for diamond this happens under different temperature than for SiC, thus internal strains in the composites are unavoidable.

  6. CORCON-MOD3: An integrated computer model for analysis of molten core-concrete interactions. User`s manual

    SciTech Connect (OSTI)

    Bradley, D.R.; Gardner, D.R.; Brockmann, J.E.; Griffith, R.O.

    1993-10-01

    The CORCON-Mod3 computer code was developed to mechanistically model the important core-concrete interaction phenomena, including those phenomena relevant to the assessment of containment failure and radionuclide release. The code can be applied to a wide range of severe accident scenarios and reactor plants. The code represents the current state of the art for simulating core debris interactions with concrete. This document comprises the user`s manual and gives a brief description of the models and the assumptions and limitations in the code. Also discussed are the input parameters and the code output. Two sample problems are also given.

  7. Developing Fully Coupled Dynamical Reactor Core Isolation System Models in RELAP-7 for Extended Station Black-Out Analysis

    SciTech Connect (OSTI)

    Haihua Zhao; Ling Zou; Hongbin Zhang; David Andrs; Richard Martineau

    2014-04-01

    The reactor core isolation cooling (RCIC) system in a boiling water reactor (BWR) provides makeup water to the reactor vessel for core cooling when the main steam lines are isolated and the normal supply of water to the reactor vessel is lost. It was one of the very few safety systems still available during the Fukushima Daiichi accidents after the tsunamis hit the plants and the system successfully delayed the core meltdown for a few days for unit 2 & 3. Therefore, detailed models for RCIC system components are indispensable to understand extended station black-out accidents (SBO) for BWRs. As part of the effort to develop the new generation reactor system safety analysis code RELAP-7, major components to simulate the RCIC system have been developed. This paper describes the models for those components such as turbine, pump, and wet well. Selected individual component test simulations and a simplified SBO simulation up to but before core damage is presented. The successful implementation of the simplified RCIC and wet well models paves the way to further improve the models for safety analysis by including more detailed physical processes in the near future.

  8. Extended-soft-core baryon-baryon model. II. Hyperon-nucleon interaction

    SciTech Connect (OSTI)

    Rijken, Th.A.; Yamamoto, Y.

    2006-04-15

    The YN results are presented from the extended soft-core (ESC) interactions. They consist of local and nonlocal potentials because of (i) one-boson exchanges (OBE), which are the members of nonets of pseudoscalar, vector, scalar, and axial mesons; (ii) diffractive exchanges; (iii) two-pseudoscalar exchange; and (iv) meson-pair exchange (MPE). Both the OBE and pair vertices are regulated by Gaussian form factors producing potentials with a soft behavior near the origin. The assignment of the cutoff masses for the baryon-baryon-meson (BBM) vertices is dependent on the SU(3) classification of the exchanged mesons for OBE and a similar scheme for MPE. The particular version of the ESC model, called ESC04 [T. A. Rijken, Phys. Rev. C 73, 044007 (2006)], describes nucleon-nucleon (NN) and hyperon-nucleon (YN) interactions in a unified way using broken SU(3) symmetry. Novel ingredients are the inclusion of (i) the axial-vector meson potentials and (ii) a zero in the scalar- and axial-vector meson form factors. These innovations made it possible for the first time to keep the parameters of the model close to the predictions of the {sup 3}P{sub 0} quark-antiquark creation model. This is also the case for the F/(F+D) ratios. Furthermore, the introduction of the zero helped to avoid the occurrence of unwanted bound states. Broken SU(3) symmetry serves to connect the NN and the YN channels, which leaves after fitting NN only a few free parameters for the determination of the YN interactions. In particular, the meson-baryon coupling constants are calculated via SU(3) using the coupling constants of the NN analysis as input. Here, as a novel feature, medium-strong flavor-symmetry breaking (FSB) of the coupling constants was allowed, using the {sup 3}P{sub 0} model with a Gell-Mann-Okubo hypercharge breaking for the BBM coupling. Very good fits for ESC model with and without FSB were obtained. The charge-symmetry breaking in the {lambda}p and {lambda}n channels, which is an SU(2) isospin breaking, is included in the OBE, TME, and MPE potentials. Simultaneous fits to the NN- and the YN-scattering data are described, using different options for the ESC model. For the selected 4233 NN data with energies 0{<=}T{sub lab}{<=}350 MeV, a {chi}{sup 2}/N{sub data}=1.22 was typically reached. For the usual set of 35 YN data and 3 {sigma}{sup +}p cross sections from a recent KEK experiment E289 {chi}{sup 2}/YN{sub data}{approx_equal}0.63 was obtained. In particular, we were able to fit the precise experimental datum r{sub R}=0.468{+-}0.010 for the inelastic capture ratio at rest rather well. The four versions (a,b,c, and d) of ESC04 presented in this article, give different results for hypernuclei. The reported G-matrix calculations are performed for YN ({lambda}N,{sigma}N,{xi}N) pairs in nuclear matter. The obtained well depths (U{sub {lambda}},U{sub {sigma}},U{sub {xi}}) reveal distinct features of ESC04a-d. The {lambda}{lambda} interactions are demonstrated to be consistent with the observed data of {sub {lambda}}{sub {lambda}}{sup 6}He. The possible three-body effects are investigated by considering phenomenologically the changes of the vector-meson masses.

  9. Benchmark of Atucha-2 PHWR RELAP5-3D control rod model by Monte Carlo MCNP5 core calculation

    SciTech Connect (OSTI)

    Pecchia, M.; D'Auria, F.; Mazzantini, O.

    2012-07-01

    Atucha-2 is a Siemens-designed PHWR reactor under construction in the Republic of Argentina. Its geometrical complexity and peculiarities require the adoption of advanced Monte Carlo codes for performing realistic neutronic simulations. Therefore core models of Atucha-2 PHWR were developed using MCNP5. In this work a methodology was set up to collect the flux in the hexagonal mesh by which the Atucha-2 core is represented. The scope of this activity is to evaluate the effect of obliquely inserted control rod on neutron flux in order to validate the RELAP5-3D{sup C}/NESTLE three dimensional neutron kinetic coupled thermal-hydraulic model, applied by GRNSPG/UNIPI for performing selected transients of Chapter 15 FSAR of Atucha-2. (authors)

  10. Effect of attractive interactions on the water-like anomalies of a core-softened model potential

    SciTech Connect (OSTI)

    Pant, Shashank; Gera, Tarun; Choudhury, Niharendu E-mail: niharc2002@yahoo.com

    2013-12-28

    It is now well established that water-like anomalies can be reproduced by a spherically symmetric potential with two length scales, popularly known as core-softened potential. In the present study we aim to investigate the effect of attractive interactions among the particles in a model fluid interacting with core-softened potential on the existence and location of various water-like anomalies in the temperature-pressure plane. We employ extensive molecular dynamic simulations to study anomalous nature of various order parameters and properties under isothermal compression. Order map analyses have also been done for all the potentials. We observe that all the systems with varying depth of attractive wells show structural, dynamic, and thermodynamic anomalies. As many of the previous studies involving model water and a class of core softened potentials have concluded that the structural anomaly region encloses the diffusion anomaly region, which in turn, encloses the density anomaly region, the same pattern has also been observed in the present study for the systems with less depth of attractive well. For the systems with deeper attractive well, we observe that the diffusion anomaly region shifts toward higher densities and is not always enclosed by the structural anomaly region. Also, density anomaly region is not completely enclosed by diffusion anomaly region in this case.

  11. Extended step characteristic model for quarter-core gamma heating calculations

    SciTech Connect (OSTI)

    DeHart, M.D.; Webb, R.L. )

    1993-01-01

    Discrete ordinates codes are seldom used in lattice or core calculation, because of their limitation to simple geometries, which can be represented using an orthogonal mesh in a given coordinate system. Rough geometric approximations are often applied to obtain an estimate for a flux distribution. However, other methods, such as integral transport or Monte Carlo approaches, are generally more suited to irregular geometries. Each of these methods has its own weaknesses: integral transport methods are limited to problems in which the angular variation of the flux is isotropic or linearly anisotropic; Monte Carlo methods can be time consuming. The extended step characteristic (ESC) method has been developed to apply the discrete ordinates approximation to complicated geometries for which other methods provide less satisfactory solutions. The CENTAUR code has been developed to solve the two-dimensional transport equation using the ESC approach. This paper presents results of CENTAUR calculations for a quarter-core gamma redistribution problem for the Savannah River site (SRS) K reactor, under drained tank conditions following a postulated double-ended guillotine break loss-of-coolant accident. The calculations were used to confirm TWOTRAN calculations, which were based on a coarse approximation of the core geometry. A comparison of the results serves to demonstrate the capabilities and efficiency of the ESC approach.

  12. Core Specialization

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

    Core Specialization Core Specialization Core Specialization (CS) is a feature of the Cray operating system that allows the user to reserve one or more cores per node for handling system services, and thus reduce the effects of timing jitter due to interruptions from the operating system at the expense of (possibly) requiring more nodes to run an application. The specialized cores may also be used in conjunction with Cray's MPI asynchronous progress engine [1] to improve the overlap of

  13. SELF-CONSISTENT MODEL OF THE INTERSTELLAR PICKUP PROTONS, ALFVENIC TURBULENCE, AND CORE SOLAR WIND IN THE OUTER HELIOSPHERE

    SciTech Connect (OSTI)

    Gamayunov, Konstantin V.; Zhang Ming; Rassoul, Hamid K.; Pogorelov, Nikolai V.; Heerikhuisen, Jacob

    2012-09-20

    A self-consistent model of the interstellar pickup protons, the slab component of the Alfvenic turbulence, and core solar wind (SW) protons is presented for r {>=} 1 along with the initial results of and comparison with the Voyager 2 (V2) observations. Two kinetic equations are used for the pickup proton distribution and Alfvenic power spectral density, and a third equation governs SW temperature including source due to the Alfven wave energy dissipation. A fraction of the pickup proton free energy, f{sub D} , which is actually released in the waveform during isotropization, is taken from the quasi-linear consideration without preexisting turbulence, whereas we use observations to specify the strength of the large-scale driving, C{sub sh}, for turbulence. The main conclusions of our study can be summarized as follows. (1) For C{sub sh} Almost-Equal-To 1-1.5 and f{sub D} Almost-Equal-To 0.7-1, the model slab component agrees well with the V2 observations of the total transverse magnetic fluctuations starting from {approx}8 AU. This indicates that the slab component at low-latitudes makes up a majority of the transverse magnetic fluctuations beyond 8-10 AU. (2) The model core SW temperature agrees well with the V2 observations for r {approx}> 20 AU if f{sub D} Almost-Equal-To 0.7-1. (3) A combined effect of the Wentzel-Kramers-Brillouin attenuation, large-scale driving, and pickup proton generated waves results in the energy sink in the region r {approx}< 10 AU, while wave energy is pumped in the turbulence beyond 10 AU. Without energy pumping, the nonlinear energy cascade is suppressed for r {approx}< 10 AU, supplying only a small energy fraction into the k-region of dissipation by the core SW protons. A similar situation takes place for the two-dimensional turbulence. (4) The energy source due to the resonant Alfven wave damping by the core SW protons is small at heliocentric distances r {approx}< 10 AU for both the slab and the two-dimensional turbulent components. As a result, adiabatic cooling mostly controls the model SW temperature in this region, and the model temperature disagrees with the V2 observations in the region r {approx}< 20 AU.

  14. Properties of a soft-core model of methanol: An integral equation theory and computer simulation study

    SciTech Connect (OSTI)

    Hu, Matej; Urbic, Tomaz; Muna, Gianmarco

    2014-10-28

    Thermodynamic and structural properties of a coarse-grained model of methanol are examined by Monte Carlo simulations and reference interaction site model (RISM) integral equation theory. Methanol particles are described as dimers formed from an apolar Lennard-Jones sphere, mimicking the methyl group, and a sphere with a core-softened potential as the hydroxyl group. Different closure approximations of the RISM theory are compared and discussed. The liquid structure of methanol is investigated by calculating site-site radial distribution functions and static structure factors for a wide range of temperatures and densities. Results obtained show a good agreement between RISM and Monte Carlo simulations. The phase behavior of methanol is investigated by employing different thermodynamic routes for the calculation of the RISM free energy, drawing gas-liquid coexistence curves that match the simulation data. Preliminary indications for a putative second critical point between two different liquid phases of methanol are also discussed.

  15. RECONCILING MODELS OF LUMINOUS BLAZARS WITH MAGNETIC FLUXES DETERMINED BY RADIO CORE-SHIFT MEASUREMENTS

    SciTech Connect (OSTI)

    Nalewajko, Krzysztof; Begelman, Mitchell C.; Sikora, Marek

    2014-11-20

    Estimates of magnetic field strength in relativistic jets of active galactic nuclei, obtained by measuring the frequency-dependent radio core location, imply that the total magnetic fluxes in those jets are consistent with the predictions of the magnetically arrested disk (MAD) scenario of jet formation. On the other hand, the magnetic field strength determines the luminosity of the synchrotron radiation, which forms the low-energy bump of the observed blazar spectral energy distribution (SED). The SEDs of the most powerful blazars are strongly dominated by the high-energy bump, which is most likely due to the external radiation Compton mechanism. This high Compton dominance may be difficult to reconcile with the MAD scenario, unless (1) the geometry of external radiation sources (broad-line region, hot-dust torus) is quasi-spherical rather than flat, or (2) most gamma-ray radiation is produced in jet regions of low magnetization, e.g., in magnetic reconnection layers or in fast jet spines.

  16. TWO-DIMENSIONAL CORE-COLLAPSE SUPERNOVA MODELS WITH MULTI-DIMENSIONAL...

    Office of Scientific and Technical Information (OSTI)

    Our main motivation for carrying out this study is to compare with recent 2D models produced by other groups who have obtained explosions for some progenitor stars and with recent ...

  17. Dynamic model verification studies for the thermal response of the Fort St. Vrain HTGR Core

    SciTech Connect (OSTI)

    Ball, S J

    1980-01-01

    The safety research program for high-temperature gas-cooled reactors at ORNL is directed primarily at addressing licensing questions on the Fort St. Vrain reactor near Denver, CO. An important part of the program is to make use of experimental data from the reactor to at least partially verify the dynamic simulations that are used to predict the effects of postulated accident sequences. Comparisons were made of predictions with data from four different reactor scram (trip) events from operating power levels between 30 and 50%. An optimization program was used to rationalize the differences between predictions and measurements, and, in general, excellent agreement can be obtained by adjustment of models and parameters within their uncertainty ranges. Although the optimized models are not necessarily unique, results of the study have identified areas in which some of the models were deficient.

  18. Continuum-kinetic-microscopic model of lung clearance due to core-annular fluid entrainment

    SciTech Connect (OSTI)

    Mitran, Sorin

    2013-07-01

    The human lung is protected against aspirated infectious and toxic agents by a thin liquid layer lining the interior of the airways. This airway surface liquid is a bilayer composed of a viscoelastic mucus layer supported by a fluid film known as the periciliary liquid. The viscoelastic behavior of the mucus layer is principally due to long-chain polymers known as mucins. The airway surface liquid is cleared from the lung by ciliary transport, surface tension gradients, and airflow shear forces. This work presents a multiscale model of the effect of airflow shear forces, as exerted by tidal breathing and cough, upon clearance. The composition of the mucus layer is complex and variable in time. To avoid the restrictions imposed by adopting a viscoelastic flow model of limited validity, a multiscale computational model is introduced in which the continuum-level properties of the airway surface liquid are determined by microscopic simulation of long-chain polymers. A bridge between microscopic and continuum levels is constructed through a kinetic-level probability density function describing polymer chain configurations. The overall multiscale framework is especially suited to biological problems due to the flexibility afforded in specifying microscopic constituents, and examining the effects of various constituents upon overall mucus transport at the continuum scale.

  19. Core Specialization

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

    the user to reserve one or more cores per node for handling system services, and thus reduce the effects of timing jitter due to interruptions from the operating system at the...

  20. Extended-soft-core baryon-baryon model. I. Nucleon-nucleon scattering with the ESC04 interaction

    SciTech Connect (OSTI)

    Rijken, Th.A.

    2006-04-15

    The NN results are presented from the extended-soft-core (ESC) interactions. They consist of local and nonlocal potentials due to (i) one-boson-exchanges (OBE), which are the members of nonets of pseudoscalar, vector, scalar, and axial mesons (ii) diffractive exchanges (iii) two-pseudoscalar exchanges (PS-PS), and (iv) meson-pair exchanges (MPE). We describe a fit to the pp and np data for 0{<=}T{sub lab}{<=}350 MeV, having a typical {chi}{sup 2}/N{sub data}=1.155. Here, we used {approx}20 quasi-free physical parameters, which are coupling constants and cutoff masses. A remarkable feature of the couplings is that we were able to require them to follow rather closely the pattern predicted by the {sup 3}P{sub 0} quark-pair-creation (QPC) model. As a result the 11 OBE couplings are rather constrained, i.e., quasi free. Also, the deuteron binding energy and the several NN scattering lengths are fitted.

  1. MCNP LWR Core Generator

    SciTech Connect (OSTI)

    Fischer, Noah A.

    2012-08-14

    The reactor core input generator allows for MCNP input files to be tailored to design specifications and generated in seconds. Full reactor models can now easily be created by specifying a small set of parameters and generating an MCNP input for a full reactor core. Axial zoning of the core will allow for density variation in the fuel and moderator, with pin-by-pin fidelity, so that BWR cores can more accurately be modeled. LWR core work in progress: (1) Reflectivity option for specifying 1/4, 1/2, or full core simulation; (2) Axial zoning for moderator densities that vary with height; (3) Generating multiple types of assemblies for different fuel enrichments; and (4) Parameters for specifying BWR box walls. Fuel pin work in progress: (1) Radial and azimuthal zoning for generating further unique materials in fuel rods; (2) Options for specifying different types of fuel for MOX or multiple burn assemblies; (3) Additional options for replacing fuel rods with burnable poison rods; and (4) Control rod/blade modeling.

  2. Non-local equilibrium two-phase flow model with phase change in porous media and its application to reflooding of a severely damaged reactor core

    SciTech Connect (OSTI)

    Bachrata, A.; Fichot, F.; Quintard, M.; Repetto, G.; Fleurot, J.

    2012-05-15

    A generalized non local-equilibrium, three-equation model was developed for the macroscopic description of two-phase flow heat and mass transfer in porous media subjected to phase change. Six pore-scale closure problems were proposed to determine all the effective transport coefficients for representative unit cells. An improved model is presented in this paper with the perspective of application to intense boiling phenomena. The objective of this paper is to present application of this model to the simulation of reflooding of severely damaged nuclear reactor cores. In case of accident at a nuclear power plant, water sources may not be available for a long period of time and the core heats up due to the residual power. Any attempt to inject water during core degradation can lead to quenching and further fragmentation of the core material. The fragmentation of fuel rods and melting of reactor core materials may result in the formation of a {sup d}ebris bed{sup .} The typical particle size in a debris bed might reach few millimeters (characteristic length-scale: 1 to 5 mm), which corresponds to a high permeability porous medium. The proposed two-phase flow model is implemented in the ICARECATHARE code, developed by IRSN to study severe accident scenarios in pressurized water reactors. Currently, the French IRSN has set up two experimental facilities to study debris bed reflooding, PEARL and PRELUDE, with the objective to validate safety models. The PRELUDE program studies the complex two phase flow of water and steam in a porous medium (diameter 180 mm, height 200 mm), initially heated to a high temperature (400 deg. C or 700 deg. C). The series of PRELUDE experiments achieved in 2010 constitute a significant complement to the database of high temperature bottom reflood experimental data. They provide relevant data to understand the progression of the quench front and the intensity of heat transfer. Modeling accurately these experiments required improvements to the reflooding model, especially in terms of the existence of various saturation regimes. The improved two-phase flow model shows a good agreement with PRELUDE experimental results.

  3. Scientists detect methane levels three times larger than expected over Four

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

    Corners region Methane levels larger over Four Corners region Scientists detect methane levels three times larger than expected over Four Corners region Study is first to show space-based techniques can successfully verify international regulations on fossil energy emissions. December 22, 2014 Scientists detect methane levels three times larger than expected over Four Corners region Study is first to show space-based techniques can successfully verify international regulations on fossil

  4. Unified ab initio approach to bound and unbound states: No-core shell model with continuum and its application to 7He

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

    Baroni, Simone; Navratil, Petr; Quaglioni, Sofia

    2013-03-26

    In this study, we introduce a unified approach to nuclear bound and continuum states based on the coupling of the no-core shell model (NCSM), a bound-state technique, with the no-core shell model/resonating group method (NCSM/RGM), a nuclear scattering technique. This new ab initio method, no-core shell model with continuum (NCSMC), leads to convergence properties superior to either NCSM or NCSM/RGM while providing a balanced approach to different classes of states. In the NCSMC, the ansatz for the many-nucleon wave function includes (i) a square-integrable A-nucleon component expanded in a complete harmonic oscillator basis and (ii) a binary-cluster component with asymptoticmore » boundary conditions that can properly describe weakly bound states, resonances, and scattering. The Schrödinger equation is transformed into a system of coupled-channel integral-differential equations that we solve using a modified microscopic R-matrix formalism within a Lagrange mesh basis. We demonstrate the usefulness of the approach by investigating the unbound 7He nucleus.« less

  5. Core Capabilities | Argonne National Laboratory

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

    The Advanced Photon Source is one of the brightest sources of X-rays in the Western Hemisphere. Photons are accelerated to over 99% of the speed of light around its ring, which is the size of a baseball stadium. Click to enlarge. The Center for Nanoscale Materials at Argonne is a premier user facility, providing expertise, instruments, and infrastructure for interdisciplinary nanoscience and nanotechnology research. To view a larger version of the image, click on it. Core Capabilities Argonne's

  6. Ionic Liquid Pretreatment Process for Biomass Is Successfully Implemented at Larger Scale

    Broader source: Energy.gov [DOE]

    DOE-funded researchers have shown that a new, highly effective pretreatment process used in the production of biofuel can be executed at a larger scale than ever achieved before.

  7. DoE Early Career Research Program: Final Report: Model-Independent Dark-Matter Searches at the ATLAS Experiment and Applications of Many-core Computing to High Energy Physics

    SciTech Connect (OSTI)

    Farbin, Amir

    2015-07-15

    This is the final report of for DoE Early Career Research Program Grant Titled "Model-Independent Dark-Matter Searches at the ATLAS Experiment and Applications of Many-core Computing to High Energy Physics".

  8. Using CORE Model-Based Systems Engineering Software to Support Program Management in the U.S. Department of Energy Office of the Biomass Project: Preprint

    SciTech Connect (OSTI)

    Riley, C.; Sandor, D.; Simpkins, P.

    2006-11-01

    This paper describes how a model-based systems engineering software, CORE, is helping the U. S. Department of Energy's Office of Biomass Program assist with bringing biomass-derived biofuels to the market. This software tool provides information to guide informed decision-making as biomass-to-biofuels systems are advanced from concept to commercial adoption. It facilitates management and communication of program status by automatically generating custom reports, Gantt charts, and tables using the widely available programs of Microsoft Word, Project and Excel.

  9. OpenEI:Core content policies | Open Energy Information

    Open Energy Info (EERE)

    Core content policies Jump to: navigation, search OpenEI models its core content policies after those established by the Wikipedia.1 Specifically, the OpenEI core content...

  10. GEOS-CORE

    SciTech Connect (OSTI)

    2014-06-24

    GEOS-CORE is a code that integrates open source Libraries for linear algebra and I/O with two main LLNL-written components: (i) a set of standard finite, discrete, and discontinuous displacement element physics solvers for resolving Darcy fluid flow, explicit mechanics, implicit mechanics, and fluid-mediated fracturing, including resolution of physical behaviors both implicitly and explicitly, and (ii) a MPI-based parallelization implementation for use on generic HPC distributed memory architectures. The resultant code can be used alone for linearly elastic and quasistatic damage problems; problems involving hydraulic fracturing, where the mesh topology is dynamically changed; and general granular materials behavior. The key application domain is for low-rate stimulation and fracture control in subsurface reservoirs (e.g., enhanced geothermal sites and unconventional shale gas stimulation). GEOS-CORE also has interfaces to call external libraries for, e.g., material models and equations fo state; however, LLNL-developed EOS and material models, beyond the aforementioned linear elastic and quasi-static damage models, will not be part of the current release. GEOS-CORE's secondary applications include granular materials behavior under different load paths.

  11. GEOS-CORE

    Energy Science and Technology Software Center (OSTI)

    2014-06-24

    GEOS-CORE is a code that integrates open source Libraries for linear algebra and I/O with two main LLNL-written components: (i) a set of standard finite, discrete, and discontinuous displacement element physics solvers for resolving Darcy fluid flow, explicit mechanics, implicit mechanics, and fluid-mediated fracturing, including resolution of physical behaviors both implicitly and explicitly, and (ii) a MPI-based parallelization implementation for use on generic HPC distributed memory architectures. The resultant code can be used alone formore » linearly elastic and quasistatic damage problems; problems involving hydraulic fracturing, where the mesh topology is dynamically changed; and general granular materials behavior. The key application domain is for low-rate stimulation and fracture control in subsurface reservoirs (e.g., enhanced geothermal sites and unconventional shale gas stimulation). GEOS-CORE also has interfaces to call external libraries for, e.g., material models and equations fo state; however, LLNL-developed EOS and material models, beyond the aforementioned linear elastic and quasi-static damage models, will not be part of the current release. GEOS-CORE's secondary applications include granular materials behavior under different load paths.« less

  12. New Report Shows Trend Toward Larger Offshore Wind Systems, with 11

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

    Advanced Stage Projects Proposed in U.S. Waters | Department of Energy Report Shows Trend Toward Larger Offshore Wind Systems, with 11 Advanced Stage Projects Proposed in U.S. Waters New Report Shows Trend Toward Larger Offshore Wind Systems, with 11 Advanced Stage Projects Proposed in U.S. Waters October 23, 2013 - 10:52am Addthis The Energy Department today released a new report showing progress for the U.S. offshore wind energy market in 2012, including the completion of two commercial

  13. Multi-Group Formulation of the Temperature-Dependent Resonance Scattering Model and its Impact on Reactor Core Parameters

    SciTech Connect (OSTI)

    Ghrayeb, Shadi Z. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Mechanical and Nuclear Engineering; Ougouag, Abderrafi M. [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Ouisloumen, Mohamed [Westinghouse Electric Company, Cranberry Township, PA (United States); Ivanov, Kostadin N. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Mechanical and Nuclear Engineering

    2014-01-01

    A multi-group formulation for the exact neutron elastic scattering kernel is developed. It incorporates the neutron up-scattering effects, stemming from lattice atoms thermal motion and accounts for it within the resulting effective nuclear cross-section data. The effects pertain essentially to resonant scattering off of heavy nuclei. The formulation, implemented into a standalone code, produces effective nuclear scattering data that are then supplied directly into the DRAGON lattice physics code where the effects on Doppler Reactivity and neutron flux are demonstrated. The correct accounting for the crystal lattice effects influences the estimated values for the probability of neutron absorption and scattering, which in turn affect the estimation of core reactivity and burnup characteristics. The results show an increase in values of Doppler temperature feedback coefficients up to -10% for UOX and MOX LWR fuels compared to the corresponding values derived using the traditional asymptotic elastic scattering kernel. This paper also summarizes the results done on this topic to date.

  14. Larger sized wire arrays on 1.5 MA Z-pinch generator

    SciTech Connect (OSTI)

    Safronova, A. S. Kantsyrev, V. L. Weller, M. E. Shlyaptseva, V. V. Shrestha, I. K. Esaulov, A. A. Stafford, A.; Chuvatin, A. S.; Coverdale, C. A.; Jones, B.

    2014-12-15

    Experiments on the UNR Zebra generator with Load Current Multiplier (LCM) allow for implosions of larger sized wire array loads than at standard current of 1 MA. Advantages of larger sized planar wire array implosions include enhanced energy coupling to plasmas, better diagnostic access to observable plasma regions, and more complex geometries of the wire loads. The experiments with larger sized wire arrays were performed on 1.5 MA Zebra with LCM (the anode-cathode gap was 1 cm, which is half the gap used in the standard mode). In particular, larger sized multi-planar wire arrays had two outer wire planes from mid-atomic-number wires to create a global magnetic field (gmf) and plasma flow between them. A modified central plane with a few Al wires at the edges was put in the middle between outer planes to influence gmf and to create Al plasma flow in the perpendicular direction (to the outer arrays plasma flow). Such modified plane has different number of empty slots: it was increased from 6 up to 10, hence increasing the gap inside the middle plane from 4.9 to 7.7 mm, respectively. Such load configuration allows for more independent study of the flows of L-shell mid-atomic-number plasma (between the outer planes) and K-shell Al plasma (which first fills the gap between the edge wires along the middle plane) and their radiation in space and time. We demonstrate that such configuration produces higher linear radiation yield and electron temperatures as well as advantages of better diagnostics access to observable plasma regions and how the load geometry (size of the gap in the middle plane) influences K-shell Al radiation. In particular, K-shell Al radiation was delayed compared to L-shell mid-atomic-number radiation when the gap in the middle plane was large enough (when the number of empty slots was increased up to ten)

  15. Bent core liquid crystal elastomers

    SciTech Connect (OSTI)

    Verduzco, R.; DiMasi, E.; Luchette, P.; Ho Hong, S.; Harden, J.; Palffy-Muhoray, P.; Kilbey II, S.M.; Sprunt, S.; Gleeson, G.T. Jakli, A.

    2010-07-28

    Liquid crystal (LC) elastomers with bent-core side-groups incorporate the properties of bent-core liquid crystals in a flexible and self-supporting polymer network. Bent-core liquid crystal elastomers (BCEs) with uniform alignment were prepared by attaching a reactive bent-core LC to poly(hydrogenmethylsiloxane) and crosslinking with a divinyl crosslinker. Phase behavior studies indicate a nematic phase over a wide temperature range that approaches room temperature, and thermoelastic measurements show that these BCEs can reversibly change their length by more than a factor of two upon heating and cooling. Small-angle X-ray scattering studies reveal multiple, broad low-angle peaks consistent with short-range smectic C order of the bent-core side groups. A comparison of these patterns with predictions of a Landau model for short-range smectic C order shows that the length scale for smectic ordering in BCEs is similar to that seen in pure bent-core LCs. The combination of rubber elasticity and smectic ordering of the bent-core side groups suggests that BCEs may be promising materials for sensing, actuating, and other advanced applications.

  16. EARLIEST STAGES OF PROTOCLUSTER FORMATION: SUBSTRUCTURE AND KINEMATICS OF STARLESS CORES IN ORION

    SciTech Connect (OSTI)

    Lee, Katherine; Looney, Leslie W.; Schnee, Scott; Li Zhiyun

    2013-08-01

    We study the structure and kinematics of nine 0.1 pc scale cores in Orion with the IRAM 30 m telescope and at higher resolution eight of the cores with CARMA, using CS(2-1) as the main tracer. The single-dish moment zero maps of the starless cores show single structures with central column densities ranging from 7 to 42 Multiplication-Sign 10{sup 23} cm{sup -2} and LTE masses from 20 M{sub Sun} to 154 M{sub Sun }. However, at the higher CARMA resolution (5''), all of the cores except one fragment into 3-5 components. The number of fragments is small compared to that found in some turbulent fragmentation models, although inclusion of magnetic fields may reduce the predicted fragment number and improve the model agreement. This result demonstrates that fragmentation from parsec-scale molecular clouds to sub-parsec cores continues to take place inside the starless cores. The starless cores and their fragments are embedded in larger filamentary structures, which likely played a role in the core formation and fragmentation. Most cores show clear velocity gradients, with magnitudes ranging from 1.7 to 14.3 km s{sup -1} pc{sup -1}. We modeled one of them in detail, and found that its spectra are best explained by a converging flow along a filament toward the core center; the gradients in other cores may be modeled similarly. We infer a mass inflow rate of {approx}2 Multiplication-Sign 10{sup -3} M{sub Sun} yr{sup -1}, which is in principle high enough to overcome radiation pressure and allow for massive star formation. However, the core contains multiple fragments, and it is unclear whether the rapid inflow would feed the growth of primarily a single massive star or a cluster of lower mass objects. We conclude that fast, supersonic converging flow along filaments play an important role in massive star and cluster formation.

  17. Core Drilling Demonstration

    Broader source: Energy.gov [DOE]

    Tank Farms workers demonstrate core drilling capabilities for Hanford single-shell tanks. Core drilling is used to determine the current condition of each tank to assist in the overall assessment...

  18. Impacts of rotation on three-dimensional hydrodynamics of core-collapse supernovae

    SciTech Connect (OSTI)

    Nakamura, Ko; Kuroda, Takami; Kotake, Kei [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Takiwaki, Tomoya [Center for Computational Astrophysics, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2014-09-20

    We perform a series of simplified numerical experiments to explore how rotation impacts the three-dimensional (3D) hydrodynamics of core-collapse supernovae. For our systematic study, we employ a light-bulb scheme to trigger explosions and a three-flavor neutrino leakage scheme to treat deleptonization effects and neutrino losses from the proto-neutron-star interior. Using a 15 M {sub ?} progenitor, we compute 30 models in 3D with a wide variety of initial angular momentum and light-bulb neutrino luminosity. We find that the rotation can help the onset of neutrino-driven explosions for the models in which the initial angular momentum is matched to that obtained in recent stellar evolutionary calculations (?0.3-3 rad s{sup 1} at the center). For the models with larger initial angular momentum, the shock surface deforms to be more oblate due to larger centrifugal force. This not only makes the gain region more concentrated around the equatorial plane, but also makes the mass larger in the gain region. As a result, buoyant bubbles tend to be coherently formed and rise in the equatorial region, which pushes the revived shock toward ever larger radii until a global explosion is triggered. We find that these are the main reasons that the preferred direction of the explosion in 3D rotating models is often perpendicular to the spin axis, which is in sharp contrast to the polar explosions around the axis that were obtained in previous two-dimensional simulations.

  19. New development of laser cladding system on larger area for industrial application

    SciTech Connect (OSTI)

    Yang Xichen; Zhao Xin; Wang Baoqi

    1996-12-31

    In this work, a new laser cladding system on larger areas for industrial application has been developed. It consists of wide-band scanning mirror and automatic powder feeder by the rotating feed wheel with bucket-type scoops. It is shown that all kinds of laser cladding powders including not only Ni-base, Fe-base, Co-base, but also superfine and light ceramics powders ZrO{sub 2}, Al{sub 2}O{sub 3} as well as superfine and heavy WC, TiC with spherical and edged grains can be fed. The powder feed rate can be continuously varied from 0.5 to 200g/min, and the measured tolerance limits are less than 2% in all conditions. The powder feeder can deliver powders by both wide-band of 10--35mm and focusing band. Without the carrier gas the powder flow depends mainly on gravity. The powder stream at the nozzle is uniform, and the powder utilization factor is over 98%. Some applications in metallurgical industry have been successfully made.

  20. CORE SHAPES AND ORIENTATIONS OF CORE-SRSIC GALAXIES

    SciTech Connect (OSTI)

    Dullo, Bililign T.; Graham, Alister W., E-mail: Bdullo@astro.swin.edu.au [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, Victoria 3122 (Australia)

    2015-01-01

    The inner and outer shapes and orientations of core-Srsic galaxies may hold important clues to their formation and evolution. We have therefore measured the central and outer ellipticities and position angles for a sample of 24 core-Srsic galaxies using archival Hubble Space Telescope (HST) images and data. By selecting galaxies with core-Srsic break radii R{sub b} a measure of the size of their partially depleted corethat are ? 0.''2, we find that the ellipticities and position angles are quite robust against HST seeing. For the bulk of the galaxies, there is a good agreement between the ellipticities and position angles at the break radii and the average outer ellipticities and position angles determined over R {sub e}/2 < R < R {sub e}, where R {sub e} is the spheroids' effective half light radius. However there are some interesting differences. We find a median ''inner'' ellipticity at R{sub b} of ?{sub med}= 0.13 0.01, rounder than the median ellipticity of the ''outer'' regions ?{sub med}= 0.20 0.01, which is thought to reflect the influence of the central supermassive black hole at small radii. In addition, for the first time we find a trend, albeit weak (2? significance), such that galaxies with larger (stellar deficit-to-supermassive black hole) mass ratiosthought to be a measure of the number of major dry merger eventstend to have rounder inner and outer isophotes, suggesting a connection between the galaxy shapes and their merger histories. We show that this finding is not simply reflecting the well known result that more luminous galaxies are rounder, but it is no doubt related.

  1. Core Design Applications

    Energy Science and Technology Software Center (OSTI)

    1995-07-12

    CORD-2 is intended for core desigh applications of pressurized water reactors. The main objective was to assemble a core design system which could be used for simple calculations (such as frequently required for fuel management) as well as for accurate calculations (for example, core design after refueling).

  2. Developing Renewable Energy Projects Larger Than 10 MWs at Federal Facilities

    SciTech Connect (OSTI)

    2013-03-01

    To accomplish Federal goals for renewable energy, sustainability, and energy security, large-scale renewable energy projects must be developed and constructed on Federal sites at a significant scale with significant private investment. For the purposes of this Guide, large-scale Federal renewable energy projects are defined as renewable energy facilities larger than 10 megawatts (MW) that are sited on Federal property and lands and typically financed and owned by third parties.1 The U.S. Department of Energy’s Federal Energy Management Program (FEMP) helps Federal agencies meet these goals and assists agency personnel navigate the complexities of developing such projects and attract the necessary private capital to complete them. This Guide is intended to provide a general resource that will begin to develop the Federal employee’s awareness and understanding of the project developer’s operating environment and the private sector’s awareness and understanding of the Federal environment. Because the vast majority of the investment that is required to meet the goals for large-scale renewable energy projects will come from the private sector, this Guide has been organized to match Federal processes with typical phases of commercial project development. FEMP collaborated with the National Renewable Energy Laboratory (NREL) and professional project developers on this Guide to ensure that Federal projects have key elements recognizable to private sector developers and investors. The main purpose of this Guide is to provide a project development framework to allow the Federal Government, private developers, and investors to work in a coordinated fashion on large-scale renewable energy projects. The framework includes key elements that describe a successful, financially attractive large-scale renewable energy project. This framework begins the translation between the Federal and private sector operating environments. When viewing the overall

  3. Hopper Multi-Core FAQ

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

    24 cores per node. Franklin had only four. Q. What else is different? A. There is less memory per core. Hopper has 1.3 GB core rather than 2.0 GB core on Franklin. A code using...

  4. CORE - Performance Feedback System

    Energy Science and Technology Software Center (OSTI)

    2009-10-02

    CORE is an architecture to bridge the gaps between disparate data integration and delivery of disparate information visualization. The CORE Technology Program includes a suite of tools and user-centered staff that can facilitate rapid delivery of a deployable integrated information to users.

  5. Internal core tightener

    DOE Patents [OSTI]

    Brynsvold, Glen V.; Snyder, Jr., Harold J.

    1976-06-22

    An internal core tightener which is a linear actuated (vertical actuation motion) expanding device utilizing a minimum of moving parts to perform the lateral tightening function. The key features are: (1) large contact areas to transmit loads during reactor operation; (2) actuation cam surfaces loaded only during clamping and unclamping operation; (3) separation of the parts and internal operation involved in the holding function from those involved in the actuation function; and (4) preloaded pads with compliant travel at each face of the hexagonal assembly at the two clamping planes to accommodate thermal expansion and irradiation induced swelling. The latter feature enables use of a "fixed" outer core boundary, and thus eliminates the uncertainty in gross core dimensions, and potential for rapid core reactivity changes as a result of core dimensional change.

  6. Large-Scale Renewable Energy Guide: Developing Renewable Energy Projects Larger Than 10 MWs at Federal Facilities

    Broader source: Energy.gov [DOE]

    The Large-Scale Renewable Energy Guide: Developing Renewable Energy Projects Larger Than 10 MWs at Federal Facilities provides best practices and other helpful guidance for federal agencies developing large-scale renewable energy projects.

  7. Core shroud corner joints

    DOE Patents [OSTI]

    Gilmore, Charles B.; Forsyth, David R.

    2013-09-10

    A core shroud is provided, which includes a number of planar members, a number of unitary corners, and a number of subassemblies each comprising a combination of the planar members and the unitary corners. Each unitary corner comprises a unitary extrusion including a first planar portion and a second planar portion disposed perpendicularly with respect to the first planar portion. At least one of the subassemblies comprises a plurality of the unitary corners disposed side-by-side in an alternating opposing relationship. A plurality of the subassemblies can be combined to form a quarter perimeter segment of the core shroud. Four quarter perimeter segments join together to form the core shroud.

  8. Core assembly storage structure

    DOE Patents [OSTI]

    Jones, Jr., Charles E.; Brunings, Jay E.

    1988-01-01

    A structure for the storage of core assemblies from a liquid metal-cooled nuclear reactor. The structure comprises an enclosed housing having a substantially flat horizontal top plate, a bottom plate and substantially vertical wall members extending therebetween. A plurality of thimble members extend downwardly through the top plate. Each thimble member is closed at its bottom end and has an open end adjacent said top plate. Each thimble member has a length and diameter greater than that of the core assembly to be stored therein. The housing is provided with an inlet duct for the admission of cooling air and an exhaust duct for the discharge of air therefrom, such that when hot core assemblies are placed in the thimbles, the heat generated will by convection cause air to flow from the inlet duct around the thimbles and out the exhaust duct maintaining the core assemblies at a safe temperature without the necessity of auxiliary powered cooling equipment.

  9. 2000 BTS Core Databook

    Buildings Energy Data Book [EERE]

    0 BTS CORE DATABOOK 2000 BTS CORE DATABOOK OFFICE OF ENERGY EFFICIENCY AND RENEWABLE ENERGY * U.S. DEPARTMENT OF ENERGY This version is dated: August 7, 2000 DISCLAIMER This document was designed for the internal use of the United States Department of Energy. This document was also designed to be occasionally updated and, therefore, this copy may not reflect the most current version. This document was prepared as account of work sponsored by an agency of the United States Government. Neither the

  10. ARM - Coral Reef Cores

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

    PastCoral Reef Cores Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About ARM Global Warming FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans Coral Reef Cores Coral reefs grow in warm, saline water in the tropics and subtropics. They accumulate layer upon layer on an annual basis and leave a record of their growth (and the climate) much like rings on trees or

  11. Nuclear core positioning system

    DOE Patents [OSTI]

    Garkisch, Hans D.; Yant, Howard W.; Patterson, John F.

    1979-01-01

    A structural support system for the core of a nuclear reactor which achieves relatively restricted clearances at operating conditions and yet allows sufficient clearance between fuel assemblies at refueling temperatures. Axially displaced spacer pads having variable between pad spacing and a temperature compensated radial restraint system are utilized to maintain clearances between the fuel elements. The core support plates are constructed of metals specially chosen such that differential thermal expansion produces positive restraint at operating temperatures.

  12. Emergency core cooling system

    DOE Patents [OSTI]

    Schenewerk, William E.; Glasgow, Lyle E.

    1983-01-01

    A liquid metal cooled fast breeder reactor provided with an emergency core cooling system includes a reactor vessel which contains a reactor core comprising an array of fuel assemblies and a plurality of blanket assemblies. The reactor core is immersed in a pool of liquid metal coolant. The reactor also includes a primary coolant system comprising a pump and conduits for circulating liquid metal coolant to the reactor core and through the fuel and blanket assemblies of the core. A converging-diverging venturi nozzle with an intermediate throat section is provided in between the assemblies and the pump. The intermediate throat section of the nozzle is provided with at least one opening which is in fluid communication with the pool of liquid sodium. In normal operation, coolant flows from the pump through the nozzle to the assemblies with very little fluid flowing through the opening in the throat. However, when the pump is not running, residual heat in the core causes fluid from the pool to flow through the opening in the throat of the nozzle and outwardly through the nozzle to the assemblies, thus providing a means of removing decay heat.

  13. Core Values | The Ames Laboratory

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

    Core Values What we do and how we do it is determined by our core values. Our core values are how we operate and what we value most. They are the qualities that define our culture...

  14. THE PHYSICS OF THE NEUTRINO MECHANISM OF CORE-COLLAPSE SUPERNOVAE

    SciTech Connect (OSTI)

    Pejcha, Ondrej; Thompson, Todd A.

    2012-02-10

    Although it is known that the stalled accretion shock in models of core-collapse supernovae turns into explosion when the neutrino luminosity from the proto-neutron star (PNS) exceeds a critical value (L{sup crit}{sub {nu},core}) (the 'neutrino mechanism'), the physics of L{sup crit}{sub {nu},core} has never been systematically explored. We solve the accretion problem between the PNS surface and the accretion shock. We quantify the deep connection between the general problem of accretion flows with bounding shocks and the neutrino mechanism. In particular, we show that there is a maximum, critical sound speed above which the shock jump conditions cannot be satisfied and steady-state accretion is impossible. This physics is general and does not depend on a specific heating mechanism. For the simple model of pressure-less free fall onto a shock bounding an isothermal accretion flow, we show that shock solutions are possible only for sound speed c{sub T} < c{sup crit}{sub T} and that c{sup 2}{sub T}/v{sub esc}{sup 2} = 3/16 = 0.1875 at c{sup crit}{sub T}. We generalize this result to the supernova problem, showing that the same physics determines L{sup crit}{sub {nu},core}. The critical condition for explosion can be written as c{sup 2}{sub S}/v{sup 2}{sub esc} {approx_equal} 0.19, where c{sub S} is the adiabatic sound speed. This 'antesonic' condition describes L{sup crit}{sub {nu},core} over a broad range of parameters, and other criteria proposed in the literature fail to capture this physics. We show that the accretion luminosity reduces L{sup crit}{sub {nu},core} non-trivially. A larger PNS radius decreases L{sup crit}{sub {nu},core}, implying that a stiff high-density equation of state may be preferred. Finally, using an analytic model, we provide evidence that the reduction of L{sup crit}{sub {nu},core} seen in recent multi-dimensional simulations results from reduced cooling efficiency, rather than an increased heating rate.

  15. Grain alignment in starless cores

    SciTech Connect (OSTI)

    Jones, T. J.; Bagley, M.; Krejny, M.; Andersson, B.-G.; Bastien, P.

    2015-01-01

    We present near-IR polarimetry data of background stars shining through a selection of starless cores taken in the K band, probing visual extinctions up to A{sub V}∼48. We find that P{sub K}/τ{sub K} continues to decline with increasing A{sub V} with a power law slope of roughly −0.5. Examination of published submillimeter (submm) polarimetry of starless cores suggests that by A{sub V}≳20 the slope for P versus τ becomes ∼−1, indicating no grain alignment at greater optical depths. Combining these two data sets, we find good evidence that, in the absence of a central illuminating source, the dust grains in dense molecular cloud cores with no internal radiation source cease to become aligned with the local magnetic field at optical depths greater than A{sub V}∼20. A simple model relating the alignment efficiency to the optical depth into the cloud reproduces the observations well.

  16. Molten core retention assembly

    DOE Patents [OSTI]

    Lampe, Robert F.

    1976-06-22

    Molten fuel produced in a core overheating accident is caught by a molten core retention assembly consisting of a horizontal baffle plate having a plurality of openings therein, heat exchange tubes having flow holes near the top thereof mounted in the openings, and a cylindrical, imperforate baffle attached to the plate and surrounding the tubes. The baffle assembly is supported from the core support plate of the reactor by a plurality of hanger rods which are welded to radial beams passing under the baffle plate and intermittently welded thereto. Preferably the upper end of the cylindrical baffle terminates in an outwardly facing lip to which are welded a plurality of bearings having slots therein adapted to accept the hanger rods.

  17. CORE SATURATION BLOCKING OSCILLATOR

    DOE Patents [OSTI]

    Spinrad, R.J.

    1961-10-17

    A blocking oscillator which relies on core saturation regulation to control the output pulse width is described. In this arrangement an external magnetic loop is provided in which a saturable portion forms the core of a feedback transformer used with the thermionic or semi-conductor active element. A first stationary magnetic loop establishes a level of flux through the saturation portion of the loop. A second adjustable magnet moves the flux level to select a saturation point giving the desired output pulse width. (AEC)

  18. Flux harmonics in large SFR cores in relation with core characteristics such as power peaks

    SciTech Connect (OSTI)

    Rimpault, G.; Buiron, L.; Fontaine, B.; Sciora, P.; Tommasi, J.

    2013-07-01

    Designing future Sodium Fast Reactors (SFR) requires enhancing their operational performance and reducing the probability to go into core disruption. As a consequence of these constraints, these novel reactors exhibit rather unusual features compared to past designs. The cores are much larger with rather flat shape. The consequences of that shape on the core characteristics deserve to be studied. The approach taken in this paper is to calculate the eigenvalue associated to the first harmonic and its associated flux. It is demonstrated that these values are linked to some core features, in particular, those sensitive to spatial effects such as power peaks induced by the movement of control rods. The uncertainty associated to these characteristics is being tentatively studied and guidelines for further studied are being identified. In the development strategy of these new SFR designs, a first demonstration plant of limited installed power (around 1500 MWth) will have to be built first. Identifying the possibility of going later to higher power plants (around 3600 MWth) without facing new challenges is an important criterion for designing such a plant. That strategy is being studied, in this paper, focusing on some rather frequent initiator such as the inadvertent control rod withdrawal for different core sizes with the help of the perturbation theory and the flux harmonics. (authors)

  19. NUCLEAR REACTOR CORE DESIGN

    DOE Patents [OSTI]

    Mahlmeister, J.E.; Peck, W.S.; Haberer, W.V.; Williams, A.C.

    1960-03-22

    An improved core design for a sodium-cooled, graphitemoderated nuclear reactor is described. The improved reactor core comprises a number of blocks of moderator material, each block being in the shape of a regular prism. A number of channels, extending the length of each block, are disposed around the periphery. When several blocks are placed in contact to form the reactor core, the channels in adjacent blocks correspond with each other to form closed conduits extending the length of the core. Fuel element clusters are disposed in these closed conduits, and liquid coolant is forced through the annulus between the fuel cluster and the inner surface of the conduit. In a preferred embodiment of the invention, the moderator blocks are in the form of hexagonal prisms with longitudinal channels cut into the corners of the hexagon. The main advantage of an "edge-loaded" moderator block is that fewer thermal neutrons are absorbed by the moderator cladding, as compared with a conventional centrally loaded moderator block.

  20. Electromagnetic pump stator core

    DOE Patents [OSTI]

    Fanning, Alan W.; Olich, Eugene E.; Dahl, Leslie R.

    1995-01-01

    A stator core for supporting an electrical coil includes a plurality of groups of circumferentially abutting flat laminations which collectively form a bore and perimeter. A plurality of wedges are interposed between the groups, with each wedge having an inner edge and a thicker outer edge. The wedge outer edges abut adjacent ones of the groups to provide a continuous path around the perimeter.

  1. Electric Dipole Transitions Within The Ab initio No-Core Shell...

    Office of Scientific and Technical Information (OSTI)

    Within The Ab initio No-Core Shell Model With Continuum Citation Details In-Document Search Title: Electric Dipole Transitions Within The Ab initio No-Core Shell Model With ...

  2. MIGRATION AND GROWTH OF PROTOPLANETARY EMBRYOS. II. EMERGENCE OF PROTO-GAS-GIANT CORES VERSUS SUPER EARTH PROGENITORS

    SciTech Connect (OSTI)

    Liu, Beibei; Zhang, Xiaojia; Lin, Douglas N. C.; Aarseth, Sverre J.

    2015-01-01

    Nearly 15%-20% of solar type stars contain one or more gas giant planets. According to the core-accretion scenario, the acquisition of their gaseous envelope must be preceded by the formation of super-critical cores with masses 10times or larger than that of the Earth. It is natural to link the formation probability of gas giant planets with the supply of gases and solids in their natal disks. However, a much richer population of super Earths suggests that (1) there is no shortage of planetary building block material, (2) a gas giant's growth barrier is probably associated with whether it can merge into super-critical cores, and (3) super Earths are probably failed cores that did not attain sufficient mass to initiate efficient accretion of gas before it is severely depleted. Here we construct a model based on the hypothesis that protoplanetary embryos migrated extensively before they were assembled into bona fide planets. We construct a Hermite-Embryo code based on a unified viscous-irradiation disk model and a prescription for the embryo-disk tidal interaction. This code is used to simulate the convergent migration of embryos, and their close encounters and coagulation. Around the progenitors of solar-type stars, the progenitor super-critical-mass cores of gas giant planets primarily form in protostellar disks with relatively high (? 10{sup 7} M {sub ?} yr{sup 1}) mass accretion rates, whereas systems of super Earths (failed cores) are more likely to emerge out of natal disks with modest mass accretion rates, due to the mean motion resonance barrier and retention efficiency.

  3. Hopper Multi-Core FAQ

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

    Hopper Multi-Core FAQ Hopper Multi-Core FAQ Q. How is Hopper Different than Franklin? A. The new Hopper Phase-II system will have 24 cores per node. Franklin had only four. Q. What else is different? A. There is less memory per core. Hopper has 1.3 GB / core rather than 2.0 GB / core on Franklin. A code using MPI on Hopper may be more likely to exhaust available memory, causing an error. Additionally, Hopper's memory hierarchy is "deeper" and more non-uniform than Franklin's and this

  4. Toroidal core winder

    DOE Patents [OSTI]

    Potthoff, Clifford M.

    1978-01-01

    The disclosure is directed to an apparatus for placing wire windings on a toroidal body, such as a transformer core, having an orifice in its center. The apparatus comprises a wire storage spool, a wire loop holding continuous belt maintained in a C-shaped loop by a belt supporting structure and provision for turning the belt to place and tighten loops of wire on a toroidal body, which is disposed within the gap of the C-shaped belt loop.

  5. Banded electromagnetic stator core

    DOE Patents [OSTI]

    Fanning, Alan W.; Gonzales, Aaron A.; Patel, Mahadeo R.; Olich, Eugene E.

    1996-01-01

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups.

  6. Banded electromagnetic stator core

    DOE Patents [OSTI]

    Fanning, Alan W.; Gonzales, Aaron A.; Patel, Mahadeo R.; Olich, Eugene E.

    1994-01-01

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups.

  7. Banded electromagnetic stator core

    DOE Patents [OSTI]

    Fanning, A.W.; Gonzales, A.A.; Patel, M.R.; Olich, E.E.

    1996-06-11

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups. 5 figs.

  8. Electromagnetic pump stator core

    DOE Patents [OSTI]

    Fanning, A.W.; Olich, E.E.; Dahl, L.R.

    1995-01-17

    A stator core for supporting an electrical coil includes a plurality of groups of circumferentially abutting flat laminations which collectively form a bore and perimeter. A plurality of wedges are interposed between the groups, with each wedge having an inner edge and a thicker outer edge. The wedge outer edges abut adjacent ones of the groups to provide a continuous path around the perimeter. 21 figures.

  9. Variable depth core sampler

    DOE Patents [OSTI]

    Bourgeois, P.M.; Reger, R.J.

    1996-02-20

    A variable depth core sampler apparatus is described comprising a first circular hole saw member, having longitudinal sections that collapses to form a point and capture a sample, and a second circular hole saw member residing inside said first hole saw member to support the longitudinal sections of said first hole saw member and prevent them from collapsing to form a point. The second hole saw member may be raised and lowered inside said first hole saw member. 7 figs.

  10. Variable depth core sampler

    DOE Patents [OSTI]

    Bourgeois, Peter M.; Reger, Robert J.

    1996-01-01

    A variable depth core sampler apparatus comprising a first circular hole saw member, having longitudinal sections that collapses to form a point and capture a sample, and a second circular hole saw member residing inside said first hole saw member to support the longitudinal sections of said first hole saw member and prevent them from collapsing to form a point. The second hole saw member may be raised and lowered inside said first hole saw member.

  11. Banded electromagnetic stator core

    DOE Patents [OSTI]

    Fanning, A.W.; Gonzales, A.A.; Patel, M.R.; Olich, E.E.

    1994-04-05

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups. 5 figures.

  12. Core Analysis | Open Energy Information

    Open Energy Info (EERE)

    Area 1992 K-Ar Dates Of Hydrothermal Clays From Core Hole Vc-2B, Valles Caldera, New Mexico And Their Relation To Alteration In A Large Hydrothermal System Core Analysis At...

  13. OpenStudio Core

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

    Core 2016 Building Technologies Office Peer Review Andrew Parker, andrew.parker@nrel.gov National Renewable Energy Laboratory 2 Project Summary Timeline: Start date: Q1 FY10 Planned end date: Ongoing w/ Frequent Off-Ramping of Components Key Milestones: 1. Quarterly Major Releases 2. V2.0 (Extensive refactor with new patterns) - 9/30/2016 Budget: Total DOE $ to date: $10,106,000* Total Cost Share to date: $5,786,000 Total future DOE $: $3,500,000 Key Partners: Project Outcome: Develop BTO's

  14. OpenStudio Core

    Energy Savers [EERE]

    OpenStudio Core 2014 Building Technologies Office Peer Review Dr. Larry Brackney, larry.brackney@nrel.gov National Renewable Energy Laboratory Oliver Davis, oliver@concept3d.com concept3D Inc. Project Summary Timeline: Key Partners: Start date: Q1 FY10 Planned end date: Ongoing w/ Frequent Off-Ramping of Components Key Milestones: 1. V1.1 (Cloud) - 9/27/2013 2. V1.2 (Refrigeration) - 12/20/2013 3. V1.3 (HVAC/Refrigeration) - 3/28/2014 Budget: Total DOE $ to date: $7,655,000 * Total Cost Share to

  15. RESULTS FROM THE (1) DATA COLLECTION WORKSHOP, (2) MODELING WORKSHOP AND (3) DRILLING AND CORING METHODS WORKSHOP AS PART OF THE JOINT INDUSTRY PARTICIPATION (JIP) PROJECT TO CHARACTERIZE NATURAL GAS HYDRATES IN THE DEEPWATER GULF OF MEXICO

    SciTech Connect (OSTI)

    Stephen A. Holditch; Emrys Jones

    2002-09-01

    In 2000, Chevron began a project to learn how to characterize the natural gas hydrate deposits in the deepwater portions of the Gulf of Mexico. A Joint Industry Participation (JIP) group was formed in 2001, and a project partially funded by the U.S. Department of Energy (DOE) began in October 2001. The primary objective of this project is to develop technology and data to assist in the characterization of naturally occurring gas hydrates in the deepwater Gulf of Mexico. These naturally occurring gas hydrates can cause problems relating to drilling and production of oil and gas, as well as building and operating pipelines. Other objectives of this project are to better understand how natural gas hydrates can affect seafloor stability, to gather data that can be used to study climate change, and to determine how the results of this project can be used to assess if and how gas hydrates act as a trapping mechanism for shallow oil or gas reservoirs. As part of the project, three workshops were held. The first was a data collection workshop, held in Houston during March 14-15, 2002. The purpose of this workshop was to find out what data exist on gas hydrates and to begin making that data available to the JIP. The second and third workshop, on Geoscience and Reservoir Modeling, and Drilling and Coring Methods, respectively, were held simultaneously in Houston during May 9-10, 2002. The Modeling Workshop was conducted to find out what data the various engineers, scientists and geoscientists want the JIP to collect in both the field and the laboratory. The Drilling and Coring workshop was to begin making plans on how we can collect the data required by the project's principal investigators.

  16. PROCESS FOR JACKETING A CORE

    DOE Patents [OSTI]

    Last, G.A.

    1960-07-19

    A process is given for enclosing the uranium core of a nuclear fuel element by placing the core in an aluminum cup and closing the open end of the cup over the core. As the metal of the cup is brought together in a weld over the center of the end of the core, it is extruded inwardly as internal projection into a central recess in the core and outwardly as an external projection. Thus oxide inclusions in the weld of the cup are spread out into the internal and external projections and do not interfere with the integrity of the weld.

  17. NEUTRONIC REACTOR CORE

    DOE Patents [OSTI]

    Thomson, W.B.; Corbin, A. Jr.

    1961-07-18

    An improved core for a gas-cooled power reactor which admits gas coolant at high temperatures while affording strong integral supporting structure and efficient moderation of neutrons is described. The multiplicities of fuel elements constituting the critical amassment of fissionable material are supported and confined by a matrix of metallic structure which is interspersed therebetween. Thermal insulation is interposed between substantially all of the metallic matrix and the fuel elements; the insulation then defines the principal conduit system for conducting the coolant gas in heat-transfer relationship with the fuel elements. The metallic matrix itseif comprises a system of ducts through which an externally-cooled hydrogeneous liquid, such as water, is circulated to serve as the principal neutron moderant for the core and conjointly as the principal coolant for the insulated metallic structure. In this way, use of substantially neutron transparent metals, such as aluminum, becomes possible for the supporting structure, despite the high temperatures of the proximate gas. The Aircraft Nuclear Propulsion program's "R-1" reactor design is a preferred embodiment.

  18. Core fluctuations test. Revision 1

    SciTech Connect (OSTI)

    Betts, W.S.

    1987-06-01

    Fluctuations were first encountered in the Fort St. Vrain reactor early in cycle 1 operation, during the initial rise from 40% to 70% power. Subsequent in-core tests and operation throughout cycles 1 and 2 demonstrated that fluctuations were repeatable, occurring at core pressure drops of between 2.5 psi and 4.0 psi, and that in each instance their characteristics were very similar. Subsequently, tests and analysis were done to understand the core fluctuation phenomenon. These efforts also lead to a design fix which stopped these fluctuations in the FSV reactor core. This fix required that keys be used in addition to the keys in the core support floor which already existed. This report outlines a test plan to validate that core fluctuations will not occur in the MHTGR core. 2 refs., 12 figs., 3 tabs.

  19. core values | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Blog Home core values core values Livermore Field Office sets core values as part of continuous improvement process At their recent off-site continuous improvement session,...

  20. Category:Core Analysis | Open Energy Information

    Open Energy Info (EERE)

    Analysis page? For detailed information on Core Analysis as exploration techniques, click here. Category:Core Analysis Add.png Add a new Core Analysis Technique Pages in...

  1. Large Flow Birefringence of Nematogenic Bent-Core Liquid Crystals

    SciTech Connect (OSTI)

    Bailey, C.; Fodor-Csorba, K; Verduzco, R; Gleeson, J; Sprunt, S; Jakli, A

    2009-01-01

    We have found that bent-core liquid crystalline materials show exceptionally large intrinsic flow birefringence in their isotropic liquid phase. This effect is more than 100 times larger than typical values measured for low molecular weight liquid crystals. The specific flow birefringence (i.e., normalized by the flow viscosity) is an order of magnitude larger than in both side-chain polymeric as well as low molecular weight liquid crystals. We propose that this large enhancement for bent-core compounds may be attributed to nanoscale smecticlike clusters that persist above the nematic-isotropic transition temperature, and shear align under shear flow; however, this mechanism has not yet been definitively confirmed.

  2. Full Core Multiphysics Simulation with Offline Mesh Deformation

    SciTech Connect (OSTI)

    Merzari, E.; Shemon, E. R.; Yu, Y.; Thomas, J. W.; Obabko, A.; Jain, Rajeev; Mahadevan, Vijay; Solberg, Jerome; Ferencz, R.; Whitesides, R.

    2015-12-21

    In this report, building on previous reports issued in FY13 we describe our continued efforts to integrate thermal/hydraulics, neutronics, and structural mechanics modeling codes to perform coupled analysis of a representative fast sodium-cooled reactor core. The focus of the present report is a full core simulation with off-line mesh deformation.

  3. ORIGIN OF THE DENSE CORE MASS FUNCTION IN CONTRACTING FILAMENTS

    SciTech Connect (OSTI)

    Myers, Philip C.

    2013-02-20

    Mass functions of starless dense cores (CMFs) may arise from contraction and dispersal of core-forming filaments. In an illustrative model, a filament contracts radially by self-gravity, increasing the mass of its cores. During this contraction, FUV photoevaporation and ablation by shocks and winds disperse filament gas and limit core growth. The stopping times of core growth are described by a waiting-time distribution. The initial filament column density profile and the resulting CMF each match recent Herschel observations in detail. Then low-mass cores have short growth ages and arise from the innermost filament gas, while massive cores have long growth ages and draw from more extended filament gas. The model fits the initial density profile and CMF best for mean core density 2 Multiplication-Sign 10{sup 4} cm{sup -3} and filament dispersal timescale 0.5 Myr. Then the typical core mass, radius, mean column density, and contraction speed are respectively 0.8 solar masses, 0.06 pc, 6 Multiplication-Sign 10{sup 21} cm{sup -2}, and 0.07 km s{sup -1}, also in accord with observed values.

  4. 2001 BTS Core Databook

    Buildings Energy Data Book [EERE]

    1 BTS CORE DATABOOK OFFICE OF ENERGY EFFICIENCY AND RENEWABLE ENERGY U.S. DEPARTMENT OF ENERGY This version is dated: November 30, 2001 REVISED data tables on the web site that have been changed since November 30, 2001 include tables: 5.6.7 5.6.8 5.6.9 5.10.8 5.10.9 5.10.10 5.10.11 5.10.12 5.10.13 5.10.14 5.10.15 5.10.16 5.10.17 5.10.18 NEW data tables on the web site that have been added since July 13, 2001 include tables: 5.6.14 5.9.7 5.9.8 5.9.9 REVISED data tables on the web site that have

  5. Core File Settings | Argonne Leadership Computing Facility

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

    Settings About Core Files By default, a rank that aborts will dump core, and the control system will signal the other ranks to quit (without dumping core). Multiple core files...

  6. Core Values Postcard | The Ames Laboratory

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

    Core Values Postcard Document Number: NA Effective Date: 09/2014 File (public): PDF icon Print_CoreValuesPostcard

  7. HMX Cooling Core Optimization Software

    Energy Science and Technology Software Center (OSTI)

    2006-08-31

    The Software consists of code which is used to determine the optimal configuration of an HMX cooling core in a heat exchanger.

  8. THE BRIGHTEST CLUSTER GALAXY IN A85: THE LARGEST CORE KNOWN SO FAR

    SciTech Connect (OSTI)

    Lpez-Cruz, O.; Aorve, C.; Ibarra-Medel, H. J.; Birkinshaw, M.; Worrall, D. M.; Barkhouse, W. A.; Torres-Papaqui, J. P.

    2014-11-10

    We have found that the brightest cluster galaxy (BCG) in A85, Holm 15A, displays the largest core known so far. Its cusp radius, r {sub ?} = 4.57 0.06 kpc (4.''26 0.''06), is more than 18 times larger than the mean for BCGs and ? 1 kpc larger than A2261-BCG, hitherto the largest-cored BCG. Holm 15A hosts the luminous amorphous radio source 0039-095B and has the optical signature of a LINER. Scaling laws indicate that this core could host a supermassive black hole (SMBH) of mass M {sub } ? (10{sup 9}-10{sup 11}) M {sub ?}. We suggest that cores this large represent a relatively short phase in the evolution of BCGs, whereas the masses of their associated SBMH might be set by initial conditions.

  9. Generating unstructured nuclear reactor core meshes in parallel

    SciTech Connect (OSTI)

    Jain, Rajeev; Tautges, Timothy J.

    2014-10-24

    Recent advances in supercomputers and parallel solver techniques have enabled users to run large simulations problems using millions of processors. Techniques for multiphysics nuclear reactor core simulations are under active development in several countries. Most of these techniques require large unstructured meshes that can be hard to generate in a standalone desktop computers because of high memory requirements, limited processing power, and other complexities. We have previously reported on a hierarchical lattice-based approach for generating reactor core meshes. Here, we describe efforts to exploit coarse-grained parallelism during reactor assembly and reactor core mesh generation processes. We highlight several reactor core examples including a very high temperature reactor, a full-core model of the Korean MONJU reactor, a ¼ pressurized water reactor core, the fast reactor Experimental Breeder Reactor-II core with a XX09 assembly, and an advanced breeder test reactor core. The times required to generate large mesh models, along with speedups obtained from running these problems in parallel, are reported. A graphical user interface to the tools described here has also been developed.

  10. Heat recuperator having ceramic core

    SciTech Connect (OSTI)

    Kohnken, K.H.

    1987-08-25

    This patent describes a recuperator comprising a ceramic heat-exchanger core within a housing, the core having six faces, two solid and four having openings for the flow of gas therethrough, the improvement comprising a layer of intumescent material disposed between a solid face and the housing.

  11. COVERING A CORE BY EXTRUSION

    DOE Patents [OSTI]

    Karnie, A.J.

    1963-07-16

    A method of covering a cylindrical fuel core with a cladding metal ms described. The metal is forced between dies around the core from both ends in two opposing skirts, and as these meet the ends turn outward into an annular recess in the dics. By cutting off the raised portion formed by the recess, oxide impurities are eliminated. (AEC)

  12. Idaho Cleanup Core Project(ICP-Core) Contract

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

    Core / Fluor Idaho, LLC Contract No. DE-EM0004083 Modifications You are here: DOE-ID Home > Contracts, Financial Assistance & Solicitations > ICP-Core Contract > ICP-Core Basic Contract Blue Line Link to free copy of Acrobat Reader Some of the documents on this page are in the Adobe PDF format. The Adobe Reader is required to access them. If you do not currently have the Acrobat Reader, you may download the Reader FREE by clicking on the icon on the left. Please note that URL

  13. Core Values | Department of Energy

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

    Core Values Core Values People - People are our most important resource. We respect and use our experience and skills and appreciate our diversity. Business Excellence - We are fiscally responsible and actively pursue best business practices. Safety - We protect our human and material resources and promote safe work practices within the office and at our sites. Communication - We take full advantage of our virtual organization's strengths and share information freely across all levels of the

  14. Using Direct Metal Deposition to Fabricate Mold Plates for an Injection Mold Machine Allowing for the Evaluation of Cost Effective Near-Sourcing Opportunities in Larger, High Volume Consumer Products

    SciTech Connect (OSTI)

    Duty, Chad E; Groh, Bill

    2014-10-31

    ORNL collaborated with Radio Systems Corporation to investigate additive manufacturing (AM) of mold plates for plastic injection molding by direct metal deposition. The team s modelling effort identified a 100% improvement in heat transfer through use of conformal cooling lines that could be built into the mold using a revolutionary design enabled by additive manufacturing. Using the newly installed laser deposition system at the ORNL Manufacturing Demonstration Facility (MDF) a stainless steel mold core was printed.

  15. Generating unstructured nuclear reactor core meshes in parallel

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

    Jain, Rajeev; Tautges, Timothy J.

    2014-10-24

    Recent advances in supercomputers and parallel solver techniques have enabled users to run large simulations problems using millions of processors. Techniques for multiphysics nuclear reactor core simulations are under active development in several countries. Most of these techniques require large unstructured meshes that can be hard to generate in a standalone desktop computers because of high memory requirements, limited processing power, and other complexities. We have previously reported on a hierarchical lattice-based approach for generating reactor core meshes. Here, we describe efforts to exploit coarse-grained parallelism during reactor assembly and reactor core mesh generation processes. We highlight several reactor coremore » examples including a very high temperature reactor, a full-core model of the Korean MONJU reactor, a ¼ pressurized water reactor core, the fast reactor Experimental Breeder Reactor-II core with a XX09 assembly, and an advanced breeder test reactor core. The times required to generate large mesh models, along with speedups obtained from running these problems in parallel, are reported. A graphical user interface to the tools described here has also been developed.« less

  16. GreenCore Capital | Open Energy Information

    Open Energy Info (EERE)

    GreenCore Capital Jump to: navigation, search Logo: GreenCore Capital Name: GreenCore Capital Address: 10509 Vista Sorrento Parkway Place: San Diego, California Zip: 92121 Region:...

  17. Electric Dipole Transitions Within The Ab initio No-Core Shell...

    Office of Scientific and Technical Information (OSTI)

    Electric Dipole Transitions Within The Ab initio No-Core Shell Model With Continuum Citation Details In-Document Search Title: Electric Dipole Transitions Within The Ab initio...

  18. Caldicellulosiruptor Core and Pangenomes Reveal Determinants...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Caldicellulosiruptor Core and Pangenomes Reveal Determinants for Citation Details In-Document Search Title: Caldicellulosiruptor Core and Pangenomes Reveal ...

  19. Natural radionuclides in ground waters and cores

    SciTech Connect (OSTI)

    Laul, J.C.; Smith, M.R.; Maiti, T.C.

    1988-01-01

    Investigations of natural radionuclides of uranium and thorium decay series in site-specific ground waters and cores (water/rock interaction) can provide information on the expected migration behavior of their radioactive waste and analog radionuclides in the unlikely event of radioactive releases from a repository. These data in ground waters can provide in situ retardation and sorption/desorption parameters for transport models and their associated kinetics (residence time). These data in cores can also provide information on migration or leaching up to a period of about one million years. Finally, the natural radionuclide data can provide baseline information for future monitoring of possible radioactive waste releases. The natural radionuclides of interest are {sup 238}U, {sup 234}Th, {sup 234}U, {sup 230}Th, {sup 226}Ra, {sup 222}Rn, {sup 210}Pb, {sup 210}Bi, {sup 210}Po, {sup 232}Th, {sup 228}Ra, {sup 228}Th, and {sup 224}Ra. The half-lives of the daughter radionuclides range from 3 days to 2.5 x 10{sup 5} yr. The data discussed are for low ionic strength ground waters from the Hanford (basalt) site and briny ground waters (high ionic strength) and cores from the Deaf Smith salt site. Similar applications of the natural radionuclide data can be extended to the Nevada Tuff repository site and subseabed disposal site. The concentrations of uranium, thorium, radium, lead, and polonium radionuclides are generally very low in ground waters. However, significant differences in disequilibrium exist between basalt and briny ground waters.

  20. Computed microtomography of reservoir core samples

    SciTech Connect (OSTI)

    Coles, M.E.; Muegge, E.L.; Spanne, P.; Jones, K.W.

    1995-03-01

    X-ray computed tomography (CT) is often utilized to evaluate and characterize structural characteristics within reservoir core material systems. Generally, medical CT scanners have been employed because of their availability and ease of use. Of interest lately has been the acquisition of three-dimensional, high resolution descriptions of rock and pore structures for characterization of the porous media and for modeling of single and multiphase transport processes. The spatial resolution of current medical CT scanners is too coarse for pore level imaging of most core samples. Recently developed high resolution computed microtomography (CMT) using synchrotron X-ray sources is analogous to conventional medical CT scanning and provides the ability to obtain three-dimensional images of specimens with a spatial resolution on the order of micrometers. Application of this technique to the study of core samples provides two- and three-dimensional high resolution description of pore structure and mineral distributions. Pore space and interconnectivity is accurately characterized and visualized. Computed microtomography data can serve as input into pore-level simulation techniques. A generalized explanation of the technique is provided, with comparison to conventional CT scanning techniques and results. Computed microtomographic results of several sandstone samples are presented and discussed. Bulk porosity values and mineralogical identification were obtained from the microtomograms and compared with gas porosity and scanning electron microscope results on tandem samples.

  1. Essential Ingredients in Core-collapse Supernovae

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

    Hix, William Raphael; Lentz, E. J.; Endeve, Eirik; Baird, Mark L.; Chertkow, Merek A.; Harris, James A.; Messer, Bronson; Mezzacappa, Anthony; Bruenn, S. W.; Blondin, J. M.

    2014-03-27

    Marking the inevitable death of a massive star, and the birth of a neutron star or black hole, core-collapse supernovae bring together physics at a wide range in spatial scales, from kilometer-sized hydrodynamic motions (eventually growing to gigameter scale) down to femtometer scale nuclear reactions. Carrying 10more » $$^{44}$$ joules of kinetic energy and a rich-mix of newly synthesized atomic nuclei, core-collapse supernovae are the preeminent foundries of the nuclear species which make up ourselves and our solar system. We will discuss our emerging understanding of the convectively unstable, neutrino-driven explosion mechanism, based on increasingly realistic neutrino-radiation hydrodynamic simulations that include progressively better nuclear and particle physics. Recent multi-dimensional models with spectral neutrino transport from several research groups, which slowly develop successful explosions for a range of progenitors, have motivated changes in our understanding of the neutrino reheating mechanism. In a similar fashion, improvements in nuclear physics, most notably explorations of weak interactions on nuclei and the nuclear equation of state, continue to refine our understanding of how supernovae explode. Recent progress on both the macroscopic and microscopic effects that affect core-collapse supernovae are discussed.« less

  2. Modeling particle deposition on HVAC heat exchangers

    SciTech Connect (OSTI)

    Siegel, J.A.; Nazaroff, W.W.

    2002-01-01

    Fouling of fin-and-tube heat exchangers by particle deposition leads to diminished effectiveness in supplying ventilation and air conditioning. This paper explores mechanisms that cause particle deposition on heat exchanger surfaces. We present a model that accounts for impaction, diffusion, gravitational settling, and turbulence. Simulation results suggest that some submicron particles deposit in the heat exchanger core, but do not cause significant performance impacts. Particles between 1 and 10 {micro}m deposit with probabilities ranging from 1-20% with fin edge impaction representing the dominant mechanism. Particles larger than 10 {micro}m deposit by impaction on refrigerant tubes, gravitational settling on fin corrugations, and mechanisms associated with turbulent airflow. The model results agree reasonably well with experimental data, but the deposition of larger particles at high velocities is underpredicted. Geometric factors, such as discontinuities in the fins, are hypothesized to be responsible for the discrepancy.

  3. Reactor core isolation cooling system

    DOE Patents [OSTI]

    Cooke, F.E.

    1992-12-08

    A reactor core isolation cooling system includes a reactor pressure vessel containing a reactor core, a drywell vessel, a containment vessel, and an isolation pool containing an isolation condenser. A turbine is operatively joined to the pressure vessel outlet steamline and powers a pump operatively joined to the pressure vessel feedwater line. In operation, steam from the pressure vessel powers the turbine which in turn powers the pump to pump makeup water from a pool to the feedwater line into the pressure vessel for maintaining water level over the reactor core. Steam discharged from the turbine is channeled to the isolation condenser and is condensed therein. The resulting heat is discharged into the isolation pool and vented to the atmosphere outside the containment vessel for removing heat therefrom. 1 figure.

  4. Reactor core isolation cooling system

    DOE Patents [OSTI]

    Cooke, Franklin E.

    1992-01-01

    A reactor core isolation cooling system includes a reactor pressure vessel containing a reactor core, a drywell vessel, a containment vessel, and an isolation pool containing an isolation condenser. A turbine is operatively joined to the pressure vessel outlet steamline and powers a pump operatively joined to the pressure vessel feedwater line. In operation, steam from the pressure vessel powers the turbine which in turn powers the pump to pump makeup water from a pool to the feedwater line into the pressure vessel for maintaining water level over the reactor core. Steam discharged from the turbine is channeled to the isolation condenser and is condensed therein. The resulting heat is discharged into the isolation pool and vented to the atmosphere outside the containment vessel for removing heat therefrom.

  5. Gelcasting Alumina Cores for Investment Casting

    SciTech Connect (OSTI)

    Janney, M A; Klug, F J

    2001-01-01

    General Electric currently uses silica investment casting cores for making superalloy turbine blades. The silica core technology does not provide the degree of dimensional control needed for advanced turbine system manufacture. The sum of the various process variables in silica core manufacturing produces cores that have more variability than is allowed for in advanced, power-generation gas turbine airfoils.

  6. Core-melt source reduction system

    DOE Patents [OSTI]

    Forsberg, C.W.; Beahm, E.C.; Parker, G.W.

    1995-04-25

    A core-melt source reduction system for ending the progression of a molten core during a core-melt accident and resulting in a stable solid cool matrix. The system includes alternating layers of a core debris absorbing material and a barrier material. The core debris absorbing material serves to react with and absorb the molten core such that containment overpressurization and/or failure does not occur. The barrier material slows the progression of the molten core debris through the system such that the molten core has sufficient time to react with the core absorbing material. The system includes a provision for cooling the glass/molten core mass after the reaction such that a stable solid cool matrix results. 4 figs.

  7. Core-melt source reduction system

    DOE Patents [OSTI]

    Forsberg, Charles W.; Beahm, Edward C.; Parker, George W.

    1995-01-01

    A core-melt source reduction system for ending the progression of a molten core during a core-melt accident and resulting in a stable solid cool matrix. The system includes alternating layers of a core debris absorbing material and a barrier material. The core debris absorbing material serves to react with and absorb the molten core such that containment overpressurization and/or failure does not occur. The barrier material slows the progression of the molten core debris through the system such that the molten core has sufficient time to react with the core absorbing material. The system includes a provision for cooling the glass/molten core mass after the reaction such that a stable solid cool matrix results.

  8. Laminated grid and web magnetic cores

    DOE Patents [OSTI]

    Sefko, John; Pavlik, Norman M.

    1984-01-01

    A laminated magnetic core characterized by an electromagnetic core having core legs which comprise elongated apertures and edge notches disposed transversely to the longitudinal axis of the legs, such as high reluctance cores with linear magnetization characteristics for high voltage shunt reactors. In one embodiment the apertures include compact bodies of microlaminations for more flexibility and control in adjusting permeability and/or core reluctance.

  9. Stability of Molten Core Materials

    SciTech Connect (OSTI)

    Layne Pincock; Wendell Hintze

    2013-01-01

    The purpose of this report is to document a literature and data search for data and information pertaining to the stability of nuclear reactor molten core materials. This includes data and analysis from TMI-2 fuel and INLs LOFT (Loss of Fluid Test) reactor project and other sources.

  10. Large core fiber optic cleaver

    DOE Patents [OSTI]

    Halpin, J.M.

    1996-03-26

    The present invention relates to a device and method for cleaving optical fibers which yields cleaved optical fiber ends possessing high damage threshold surfaces. The device can be used to cleave optical fibers with core diameters greater than 400 {micro}m. 30 figs.

  11. Large core fiber optic cleaver

    DOE Patents [OSTI]

    Halpin, John M.

    1996-01-01

    The present invention relates to a device and method for cleaving optical fibers which yields cleaved optical fiber ends possessing high damage threshold surfaces. The device can be used to cleave optical fibers with core diameters greater than 400 .mu.m.

  12. Fuel Breeding and Core Behavior Analyses on In Core Fuel Management of Water Cooled Thorium Reactors

    SciTech Connect (OSTI)

    Permana, Sidik; Sekimoto, Hiroshi; Waris, Abdul; Subhki, Muhamad Nurul; Ismail,

    2010-12-23

    Thorium fuel cycle with recycled U-233 has been widely recognized having some contributions to improve the water-cooled breeder reactor program which has been shown by a feasible area of breeding and negative void reactivity which confirms that fissile of 233U contributes to better fuel breeding and effective for obtaining negative void reactivity coefficient as the main fissile material. The present study has the objective to estimate the effect of whole core configuration as well as burnup effects to the reactor core profile by adopting two dimensional model of fuel core management. About more than 40 months of cycle period has been employed for one cycle fuel irradiation of three batches fuel system for large water cooled thorium reactors. All position of fuel arrangement contributes to the total core conversion ratio which gives conversion ratio less than unity of at the BOC and it contributes to higher than unity (1.01) at the EOC after some irradiation process. Inner part and central part give the important part of breeding contribution with increasing burnup process, while criticality is reduced with increasing the irradiation time. Feasibility of breeding capability of water-cooled thorium reactors for whole core fuel arrangement has confirmed from the obtained conversion ratio which shows higher than unity. Whole core analysis on evaluating reactivity change which is caused by the change of voided condition has been employed for conservative assumption that 100% coolant and moderator are voided. It obtained always a negative void reactivity coefficient during reactor operation which shows relatively more negative void coefficient at BOC (fresh fuel composition), and it becomes less negative void coefficient with increasing the operation time. Negative value of void reactivity coefficient shows the reactor has good safety properties in relation to the reactivity profile which is the main parameter in term of criticality safety analysis. Therefore, this evaluation has confirmed that breeding condition and negative coefficient can be obtained simultaneously for water-cooled thorium reactor obtains based on the whole core fuel arrangement.

  13. EFFECTS OF RESISTIVITY ON MAGNETIZED CORE-COLLAPSE SUPERNOVAE

    SciTech Connect (OSTI)

    Sawai, H.; Suzuki, H.; Yamada, S.; Kotake, K.

    2013-02-10

    We studied the role of turbulent resistivity in the core-collapse of a strongly magnetized massive star, carrying out two-dimensional resistive-MHD simulations. Three cases with different initial strengths of magnetic field and rotation are investigated: (1) a strongly magnetized rotating core, (2) a moderately magnetized rotating core, and (3) a very strongly magnetized non-rotating core. In each case, one ideal-MHD model and two resistive-MHD models are computed. As a result of these computations, each model shows an eruption of matter assisted by magnetic acceleration (and also by centrifugal acceleration in the rotating cases). We found that resistivity attenuates the explosion in cases 1 and 2, while it enhances the explosion in case 3. We also found that in the rotating cases, the main mechanisms for the amplification of a magnetic field in the post-bounce phase are an outward advection of the magnetic field and a twisting of poloidal magnetic field lines by differential rotation, which are somewhat dampened down with the presence of resistivity. Although magnetorotational instability seems to occur in the rotating models, it plays only a minor role in magnetic field amplification. Another impact of resistivity is that on the aspect ratio. In the rotating cases, a large aspect ratio of the ejected matter, >2.5, attained in an ideal-MHD model is reduced to some extent in a resistive model. These results indicate that resistivity possibly plays an important role in the dynamics of strongly magnetized supernovae.

  14. Logging-while-coring method and apparatus

    DOE Patents [OSTI]

    Goldberg, David S.; Myers, Gregory J.

    2007-01-30

    A method and apparatus for downhole coring while receiving logging-while-drilling tool data. The apparatus includes core collar and a retrievable core barrel. The retrievable core barrel receives core from a borehole which is sent to the surface for analysis via wireline and latching tool The core collar includes logging-while-drilling tools for the simultaneous measurement of formation properties during the core excavation process. Examples of logging-while-drilling tools include nuclear sensors, resistivity sensors, gamma ray sensors, and bit resistivity sensors. The disclosed method allows for precise core-log depth calibration and core orientation within a single borehole, and without at pipe trip, providing both time saving and unique scientific advantages.

  15. Logging-while-coring method and apparatus

    DOE Patents [OSTI]

    Goldberg, David S.; Myers, Gregory J.

    2007-11-13

    A method and apparatus for downhole coring while receiving logging-while-drilling tool data. The apparatus includes core collar and a retrievable core barrel. The retrievable core barrel receives core from a borehole which is sent to the surface for analysis via wireline and latching tool The core collar includes logging-while-drilling tools for the simultaneous measurement of formation properties during the core excavation process. Examples of logging-while-drilling tools include nuclear sensors, resistivity sensors, gamma ray sensors, and bit resistivity sensors. The disclosed method allows for precise core-log depth calibration and core orientation within a single borehole, and without at pipe trip, providing both time saving and unique scientific advantages.

  16. The core mass growth and stellar lifetime of thermally pulsing asymptotic giant branch stars

    SciTech Connect (OSTI)

    Kalirai, Jason S.; Tremblay, Pier-Emmanuel; Marigo, Paola E-mail: paola.marigo@unipd.it

    2014-02-10

    We establish new constraints on the intermediate-mass range of the initial-final mass relation, and apply the results to study the evolution of stars on the thermally pulsing asymptotic giant branch (TP-AGB). These constraints derive from newly discovered (bright) white dwarfs in the nearby Hyades and Praesepe star clusters, including a total of 18 high signal-to-noise ratio measurements with progenitor masses of M {sub initial} = 2.8-3.8 M {sub ?}. We also include a new analysis of existing white dwarfs in the older NGC 6819 and NGC 7789 star clusters, M {sub initial} = 1.6 and 2.0 M {sub ?}. Over this range of initial masses, stellar evolutionary models for metallicity Z {sub initial} = 0.02 predict the maximum growth of the core of TP-AGB stars. By comparing the newly measured remnant masses to the robust prediction of the core mass at the first thermal pulse on the AGB (i.e., from stellar interior models), we establish several findings. First, we show that the stellar core mass on the AGB grows rapidly from 10% to 30% for stars with M {sub initial} = 1.6 to 2.0 M {sub ?}. At larger masses, the core-mass growth decreases steadily to ?10% at M {sub initial} = 3.4 M {sub ?}, after which there is a small hint of a upturn out to M {sub initial} = 3.8 M {sub ?}. These observations are in excellent agreement with predictions from the latest TP-AGB evolutionary models in Marigo et al. We also compare to models with varying efficiencies of the third dredge-up and mass loss, and demonstrate that the process governing the growth of the core is largely the stellar wind, while the third dredge-up plays a secondary, but non-negligible role. Based on the new white dwarf measurements, we perform an exploratory calibration of the most popular mass-loss prescriptions in the literature, as well as of the third dredge-up efficiency as a function of the stellar mass. Finally, we estimate the lifetime and the integrated luminosity of stars on the TP-AGB to peak at t ? 3 Myr and E = 1.2 10{sup 10} L {sub ?} yr for M {sub initial} ? 2 M {sub ?} (t ? 2 Myr for luminosities brighter than the red giant branch tip at log (L/L {sub ?}) > 3.4), decreasing to t = 0.4 Myr and E = 6.1 10{sup 9} L {sub ?} yr for stars with M {sub initial} ? 3.5 M {sub ?}. The implications of these results are discussed, especially with respect to general studies aimed at characterizing the integrated light output of TP-AGB stars in population synthesis models.

  17. Extended core for motor/generator

    DOE Patents [OSTI]

    Shoykhet, Boris A.

    2005-05-10

    An extended stator core in a motor/generator can be utilized to mitigate losses in end regions of the core and a frame of the motor/generator. To mitigate the losses, the stator core can be extended to a length substantially equivalent to or greater than a length of a magnetically active portion in the rotor. Alternatively, a conventional length stator core can be utilized with a shortened magnetically active portion to mitigate losses in the motor/generator. To mitigate the losses in the core caused by stator winding, the core can be extended to a length substantially equivalent or greater than a length of stator winding.

  18. Accelerator driven sub-critical core

    DOE Patents [OSTI]

    McIntyre, Peter M; Sattarov, Akhdiyor

    2015-03-17

    Systems and methods for operating an accelerator driven sub-critical core. In one embodiment, a fission power generator includes a sub-critical core and a plurality of proton beam generators. Each of the proton beam generators is configured to concurrently provide a proton beam into a different area of the sub-critical core. Each proton beam scatters neutrons within the sub-critical core. The plurality of proton beam generators provides aggregate power to the sub-critical core, via the proton beams, to scatter neutrons sufficient to initiate fission in the sub-critical core.

  19. Extended core for motor/generator

    DOE Patents [OSTI]

    Shoykhet, Boris A.

    2006-08-22

    An extended stator core in a motor/generator can be utilized to mitigate losses in end regions of the core and a frame of the motor/generator. To mitigate the losses, the stator core can be extended to a length substantially equivalent to or greater than a length of a magnetically active portion in the rotor. Alternatively, a conventional length stator core can be utilized with a shortened magnetically active portion to mitigate losses in the motor/generator. To mitigate the losses in the core caused by stator winding, the core can be extended to a length substantially equivalent or greater than a length of stator winding.

  20. Laminated electromagnetic pump stator core

    DOE Patents [OSTI]

    Fanning, A.W.

    1995-08-08

    A stator core for an electromagnetic pump includes a plurality of circumferentially abutting tapered laminations extending radially outwardly from a centerline axis to collectively define a radially inner bore and a radially outer circumference. Each of the laminations includes radially inner and outer edges and has a thickness increasing from the inner edge toward the outer edge to provide a substantially continuous path adjacent the circumference. This pump is used in nuclear fission reactors. 19 figs.

  1. Coring in deep hardrock formations

    SciTech Connect (OSTI)

    Drumheller, D.S.

    1988-08-01

    The United States Department of Energy is involved in a variety of scientific and engineering feasibility studies requiring extensive drilling in hard crystalline rock. In many cases well depths extend from 6000 to 20,000 feet in high-temperature, granitic formations. Examples of such projects are the Hot Dry Rock well system at Fenton Hill, New Mexico and the planned exploratory magma well near Mammoth Lakes, California. In addition to these programs, there is also continuing interest in supporting programs to reduce drilling costs associated with the production of geothermal energy from underground sources such as the Geysers area near San Francisco, California. The overall progression in these efforts is to drill deeper holes in higher temperature, harder formations. In conjunction with this trend is a desire to improve the capability to recover geological information. Spot coring and continuous coring are important elements in this effort. It is the purpose of this report to examine the current methods used to obtain core from deep wells and to suggest projects which will improve existing capabilities. 28 refs., 8 figs., 2 tabs.

  2. SolviCore | Open Energy Information

    Open Energy Info (EERE)

    SolviCore is JV between Umicore and Solvay focusing on the development of MEAs for fuel cells. References: SolviCore1 This article is a stub. You can help OpenEI by...

  3. HyCore | Open Energy Information

    Open Energy Info (EERE)

    HyCore Jump to: navigation, search Name: HyCore Place: Norway Sector: Hydro, Solar Product: JV between Umicore and Norsk Hydro to manufacture solar-grade silicon. References:...

  4. Core Program | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Home Core Program The Second Line of Defense (SLD) Core Program installs radiation detection equipment at borders, airports, and strategic feeder ports in Russia, former Soviet Union states, and other key countries. The Second Line of Defense (SLD) Core Program installs radiation detection equipment at borders, airports, and strategic feeder ports in Russia, former Soviet Union states, and other key countries. The Second Line of Defense (SLD) Core Program installs radiation detection equipment

  5. Analysis of fuel options for the breakeven core configuration of the Advanced Recycling Reactor

    SciTech Connect (OSTI)

    Stauff, N.E.; Klim, T.K.; Taiwo, T.A.; Fiorina, C.; Franceschini, F.

    2013-07-01

    A trade-off study is performed to determine the impacts of various fuel forms on the core design and core physics characteristics of the sodium-cooled Toshiba- Westinghouse Advanced Recycling Reactor (ARR). The fuel forms include oxide, nitride, and metallic forms of U and Th. The ARR core configuration is redesigned with driver and blanket regions in order to achieve breakeven fissile breeding performance with the various fuel types. State-of-the-art core physics tools are used for the analyses. In addition, a quasi-static reactivity balance approach is used for a preliminary comparison of the inherent safety performances of the various fuel options. Thorium-fueled cores exhibit lower breeding ratios and require larger blankets compared to the U-fueled cores, which is detrimental to core compactness and increases reprocessing and manufacturing requirements. The Th cores also exhibit higher reactivity swings through each cycle, which penalizes reactivity control and increases the number of control rods required. On the other hand, using Th leads to drastic reductions in void and coolant expansion coefficients of reactivity, with the potential for enhancing inherent core safety. Among the U-fueled ARR cores, metallic and nitride fuels result in higher breeding ratios due to their higher heavy metal densities. On the other hand, oxide fuels provide a softer spectrum, which increases the Doppler effect and reduces the positive sodium void worth. A lower fuel temperature is obtained with the metallic and nitride fuels due to their higher thermal conductivities and compatibility with sodium bonds. This is especially beneficial from an inherent safety point of view since it facilitates the reactor cool-down during loss of power removal transients. The advantages in terms of inherent safety of nitride and metallic fuels are maintained when using Th fuel. However, there is a lower relative increase in heavy metal density and in breeding ratio going from oxide to metallic or nitride Th fuels relative to the U counterpart fuels. (authors)

  6. DIAGNOSING THE TIME DEPENDENCE OF ACTIVE REGION CORE HEATING FROM THE EMISSION MEASURE. II. NANOFLARE TRAINS

    SciTech Connect (OSTI)

    Reep, J. W.; Bradshaw, S. J.; Klimchuk, J. A. E-mail: stephen.bradshaw@rice.edu

    2013-02-20

    The time dependence of heating in solar active regions can be studied by analyzing the slope of the emission measure distribution coolward of the peak. In a previous study we showed that low-frequency heating can account for 0% to 77% of active region core emission measures. We now turn our attention to heating by a finite succession of impulsive events for which the timescale between events on a single magnetic strand is shorter than the cooling timescale. We refer to this scenario as a 'nanoflare train' and explore a parameter space of heating and coronal loop properties with a hydrodynamic model. Our conclusions are (1) nanoflare trains are consistent with 86% to 100% of observed active region cores when uncertainties in the atomic data are properly accounted for; (2) steeper slopes are found for larger values of the ratio of the train duration {Delta} {sub H} to the post-train cooling and draining timescale {Delta} {sub C}, where {Delta} {sub H} depends on the number of heating events, the event duration and the time interval between successive events ({tau} {sub C}); (3) {tau} {sub C} may be diagnosed from the width of the hot component of the emission measure provided that the temperature bins are much smaller than 0.1 dex; (4) the slope of the emission measure alone is not sufficient to provide information about any timescale associated with heating-the length and density of the heated structure must be measured for {Delta} {sub H} to be uniquely extracted from the ratio {Delta} {sub H}/{Delta} {sub C}.

  7. Modeling

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

    Caterpillar, Sandia CRADA Opens Door to Multiple Research Projects Capabilities, Computational Modeling & Simulation, CRF, Materials Science, Modeling, Modeling, Modeling & ...

  8. Generator stator core vent duct spacer posts

    DOE Patents [OSTI]

    Griffith, John Wesley; Tong, Wei

    2003-06-24

    Generator stator cores are constructed by stacking many layers of magnetic laminations. Ventilation ducts may be inserted between these layers by inserting spacers into the core stack. The ventilation ducts allow for the passage of cooling gas through the core during operation. The spacers or spacer posts are positioned between groups of the magnetic laminations to define the ventilation ducts. The spacer posts are secured with longitudinal axes thereof substantially parallel to the core axis. With this structure, core tightness can be assured while maximizing ventilation duct cross section for gas flow and minimizing magnetic loss in the spacers.

  9. Framework Application for Core-Edge Transport Simulations

    Energy Science and Technology Software Center (OSTI)

    2007-06-13

    FACETS is a whole-device model for magnetic-fusion experiments (including ITER) combining physics effects from sources & sinks, wall effects, edge effects, and core effects in an advanced parallel framework which manages allocation of parallel resources, performs runtime performance analysis, and provides tools for interactive steering and visualization. FACETS will be used by fusion researchers to design experimental campaigns, predict and model fusion experimental phenomena, and design and optimize future machines.

  10. DIODE STEERED MANGETIC-CORE MEMORY

    DOE Patents [OSTI]

    Melmed, A.S.; Shevlin, R.T.; Laupheimer, R.

    1962-09-18

    A word-arranged magnetic-core memory is designed for use in a digital computer utilizing the reverse or back current property of the semi-conductor diodes to restore the information in the memory after read-out. In order to ob tain a read-out signal from a magnetic core storage unit, it is necessary to change the states of some of the magnetic cores. In order to retain the information in the memory after read-out it is then necessary to provide a means to return the switched cores to their states before read-out. A rewrite driver passes a pulse back through each row of cores in which some switching has taken place. This pulse combines with the reverse current pulses of diodes for each column in which a core is switched during read-out to cause the particular cores to be switched back into their states prior to read-out. (AEC)

  11. Controlled Release from Core-Shell Nanoporous Silica Particles...

    Office of Scientific and Technical Information (OSTI)

    Controlled Release from Core-Shell Nanoporous Silica Particles for Corrosion Inhibition of Aluminum Alloys Citation Details In-Document Search Title: Controlled Release from Core-S...

  12. Development of Toroidal Core Transformers

    SciTech Connect (OSTI)

    Leon, Francisco

    2014-05-31

    The original objective of this project was to design, build and test a few prototypes of singlephase dry-type distribution transformers of 25 kVA, 2.4 kV primary to 120 V transformers using cores made of a continuous steel strip shaped like a doughnut (toroid). At different points during the development of the project, the scope was enhanced to include the more practical case of a 25 kVA transformer for a 13.8 kV primary system voltage. Later, the scope was further expanded to design and build a 50 kVA unit to transformer voltage from 7.62 kV to 2x120 V. This is a common transformer used by Con Edison of New York and they are willing to test it in the field. The project officially started in September 2009 and ended in May 2014. The progress was reported periodically to DOE in eighteen quarterly reports. A Continuation Application was submitted to DOE in June 2010. In May 2011 we have requested a non-cost extension of the project. In December 2011, the Statement of Project Objectives (SOPO) was updated to reflect the real conditions and situation of the project as of 2011. A second Continuation Application was made and funding was approved in 2013 by DOE and the end date was extended to May 2014.The technical challenges that were overcome in this project include: the development of the technology to pass the impulse tests, derive a model for the thermal performance, produce a sound mechanical design, and estimate the inrush current. However, the greatest challenge that we faced during the development of the project was the complications of procuring the necessary parts and materials to build the transformers. The actual manufacturing process is relatively fast, but getting all parts together is a very lengthy process. The main products of this project are two prototypes of toroidal distribution transformers of 7.62 kV (to be used in a 13.8 kV system) to 2x120 V secondary (standard utilization voltage); one is rated at 25 kVA and the other at 50 kVA. The 25 kVA transformer passed the impulse test in KEMA high-voltage laboratories. Additional products include: nine papers published in the IEEE Transactions on Power Delivery, one patent has been filed, three PhD students were supported from beginning to graduation, five postdoctoral fellows, and three MSc students were partially supported. The electrical characteristics of our dry-type toroidal transformers are similar to those of the oil-immersed pole mounted transformers currently in use by many utilities, but toroids have higher efficiency. The no-load losses of the 50 kVA prototype are only 45 W. A standard transformer has no-load losses between 90 and 240 W. Thus, even the finest transformer built today with standard technology has double the amount of no-load losses than the prototype toroidal transformer. When the manufacturing process is prepared for mass production, the cost of a dry-type toroidal transformer would be similar to the price of an oil-filed standard design. However, because of the greatly reduced losses, the total ownership cost of a toroidal transformer could be about half of a traditional design. We got a grant from Power Bridge NY in the amount of $149,985 from June 2014 to May 2015 to continue developing the transformer with commercialization objectives. We are considering the possibility to incorporate a company to manufacture the transformers and have contacted investors. The current status of the real life testing is as follows: after several months of silence, Con Edison has re-started conversations and has shown willingness to test the transformer. Other companies, PSE&G and National Grid have recently also shown interest and we will present our product to them soon.

  13. Gravitational wave extraction in simulations of rotating stellar core collapse

    SciTech Connect (OSTI)

    Reisswig, C.; Ott, C. D.; Sperhake, U.; Schnetter, E.

    2011-03-15

    We perform simulations of general relativistic rotating stellar core collapse and compute the gravitational waves (GWs) emitted in the core-bounce phase of three representative models via multiple techniques. The simplest technique, the quadrupole formula (QF), estimates the GW content in the spacetime from the mass-quadrupole tensor only. It is strictly valid only in the weak-field and slow-motion approximation. For the first time, we apply GW extraction methods in core collapse that are fully curvature based and valid for strongly radiating and highly relativistic sources. These techniques are not restricted to weak-field and slow-motion assumptions. We employ three extraction methods computing (i) the Newman-Penrose (NP) scalar {Psi}{sub 4}, (ii) Regge-Wheeler-Zerilli-Moncrief master functions, and (iii) Cauchy-characteristic extraction (CCE) allowing for the extraction of GWs at future null infinity, where the spacetime is asymptotically flat and the GW content is unambiguously defined. The latter technique is the only one not suffering from residual gauge and finite-radius effects. All curvature-based methods suffer from strong nonlinear drifts. We employ the fixed-frequency integration technique as a high-pass waveform filter. Using the CCE results as a benchmark, we find that finite-radius NP extraction yields results that agree nearly perfectly in phase, but differ in amplitude by {approx}1%-7% at core bounce, depending on the model. Regge-Wheeler-Zerilli-Moncrief waveforms, while, in general, agreeing in phase, contain spurious high-frequency noise of comparable amplitudes to those of the relatively weak GWs emitted in core collapse. We also find remarkably good agreement of the waveforms obtained from the QF with those obtained from CCE. The results from QF agree very well in phase and systematically underpredict peak amplitudes by {approx}5%-11%, which is comparable to the NP results and is certainly within the uncertainties associated with core collapse physics.

  14. Test report -- Prototype core sampler

    SciTech Connect (OSTI)

    Linschooten, C.G.

    1995-01-17

    The purpose of this test is to determine the adequacy of the prototype sampler, provided to Westinghouse Hanford Company (WHC) by DOE-RL. The sampler was fabricated for DOE-RL by the Concord Company by request of DOE-RL. This prototype sampler was introduced as a technology that can be easily deployed (similar to the current auger system) and will reliably collect representative samples. The sampler is similar to the Universal Sampler i.e., smooth core barrel and piston with an O-ring seal, but lacks a rotary valve near the throat of the sampler. This makes the sampler inappropriate for liquid sampling, but reduces the outside diameter of the sampler considerably, which should improve sample recovery. Recovery testing was performed with the supplied sampler in three different consistencies of Kaolin sludge simulants.

  15. Nuclear core and fuel assemblies

    DOE Patents [OSTI]

    Downs, Robert E.

    1981-01-01

    A fast flux nuclear core of a plurality of rodded, open-lattice assemblies having a rod pattern rotated relative to a rod support structure pattern. Elongated fuel rods are oriented on a triangular array and laterally supported by grid structures positioned along the length of the assembly. Initial inter-assembly contact is through strongbacks at the corners of the support pattern and peripheral fuel rods between adjacent assemblies are nested so as to maintain a triangular pitch across a clearance gap between the other portions of adjacent assemblies. The rod pattern is rotated relative to the strongback support pattern by an angle .alpha. equal to sin .sup.-1 (p/2c), where p is the intra-assembly rod pitch and c is the center-to-center spacing among adjacent assemblies.

  16. Larger foraminifer biostratigraphy of PEACE boreholes, Enewetak Atoll, Western Pacific Ocean. Geologic and geophysical investigations of Enewetak Atoll, Republic of the Marshall Islands. Professional paper

    SciTech Connect (OSTI)

    Gibson, T.G.; Margerum, R.

    1991-01-01

    Larger foraminiferal assemblages, including Lepidocyclina orientalis, Miogypsina thecideaeformis, Miogypsinoides dehaartii, etc., and a smaller foraminifer, Austrotrillina striata, are used to correlate upper Oligocene and lower Miocene strata in the Pacific Atoll Exploration Program (PEACE) boreholes at Enewetak Atoll, Republic of the Marshall Islands, western Pacific Ocean, with the Te and Tf zones of the previously established Tertiary Far East Letter Zonation. Correlation using these two benthic groups is critical because calcareous nannofossils and planktic foraminifers are absent in the lower Miocene strata. Biostratigraphic data from these boreholes delineate a thick (greater than 700 feet) sequence of upper Oligocene and lower Miocene strata corresponding to lower and upper Te zone. These strata document a major period of carbonate accumulation at Enewetak during the Late Oligocene and early Miocene (26 to 18 million years ago).

  17. Magnetic braking of stellar cores in red giants and supergiants

    SciTech Connect (OSTI)

    Maeder, André; Meynet, Georges E-mail: georges.meynet@unige.ch

    2014-10-01

    Magnetic configurations, stable on the long term, appear to exist in various evolutionary phases, from main-sequence stars to white dwarfs and neutron stars. The large-scale ordered nature of these fields, often approximately dipolar, and their scaling according to the flux conservation scenario favor a fossil field model. We make some first estimates of the magnetic coupling between the stellar cores and the outer layers in red giants and supergiants. Analytical expressions of the truncation radius of the field coupling are established for a convective envelope and for a rotating radiative zone with horizontal turbulence. The timescales of the internal exchanges of angular momentum are considered. Numerical estimates are made on the basis of recent model grids. The direct magnetic coupling of the core to the extended convective envelope of red giants and supergiants appears unlikely. However, we find that the intermediate radiative zone is fully coupled to the core during the He-burning and later phases. This coupling is able to produce a strong spin down of the core of red giants and supergiants, also leading to relatively slowly rotating stellar remnants such as white dwarfs and pulsars. Some angular momentum is also transferred to the outer convective envelope of red giants and supergiants during the He-burning phase and later.

  18. Over Core Stress | Open Energy Information

    Open Energy Info (EERE)

    Analysis- Rock Over Core Stress Paleomagnetic Measurements Petrography Analysis Rock Density X-Ray Diffraction (XRD) X-Ray Fluorescence (XRF) References Page Area Activity Start...

  19. Core Program | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    The SLD Core program is also involved in maintaining radiation detection equipment throughout the world to help mitigate the risk of nuclear proliferation and terrorism. The SLD ...

  20. Material with core-shell structure

    DOE Patents [OSTI]

    Luhrs, Claudia; Richard, Monique N.; Dehne, Aaron; Phillips, Jonathan; Stamm, Kimber L.; Fanson, Paul T.

    2011-11-15

    Disclosed is a material having a composite particle, the composite particle including an outer shell and a core. The core is made from a lithium alloying material and the outer shell has an inner volume that is greater in size than the core of the lithium alloying material. In some instances, the outer mean diameter of the outer shell is less than 500 nanometers and the core occupies between 5 and 99% of the inner volume. In addition, the outer shell can have an average wall thickness of less than 100 nanometers.

  1. PRISMATIC CORE COUPLED TRANSIENT BENCHMARK

    SciTech Connect (OSTI)

    J. Ortensi; M.A. Pope; G. Strydom; R.S. Sen; M.D. DeHart; H.D. Gougar; C. Ellis; A. Baxter; V. Seker; T.J. Downar; K. Vierow; K. Ivanov

    2011-06-01

    The Prismatic Modular Reactor (PMR) is one of the High Temperature Reactor (HTR) design concepts that have existed for some time. Several prismatic units have operated in the world (DRAGON, Fort St. Vrain, Peach Bottom) and one unit is still in operation (HTTR). The deterministic neutronics and thermal-fluids transient analysis tools and methods currently available for the design and analysis of PMRs have lagged behind the state of the art compared to LWR reactor technologies. This has motivated the development of more accurate and efficient tools for the design and safety evaluations of the PMR. In addition to the work invested in new methods, it is essential to develop appropriate benchmarks to verify and validate the new methods in computer codes. The purpose of this benchmark is to establish a well-defined problem, based on a common given set of data, to compare methods and tools in core simulation and thermal hydraulics analysis with a specific focus on transient events. The benchmark-working group is currently seeking OECD/NEA sponsorship. This benchmark is being pursued and is heavily based on the success of the PBMR-400 exercise.

  2. Toward connecting core-collapse supernova theory with observations. I. Shock revival in a 15 M {sub ☉} blue supergiant progenitor with SN 1987A energetics

    SciTech Connect (OSTI)

    Handy, Timothy; Plewa, Tomasz; Odrzywołek, Andrzej

    2014-03-10

    We study the evolution of the collapsing core of a 15 M {sub ☉} blue supergiant supernova progenitor from the core bounce until 1.5 s later. We present a sample of hydrodynamic models parameterized to match the explosion energetics of SN 1987A. We find the spatial model dimensionality to be an important contributing factor in the explosion process. Compared to two-dimensional (2D) simulations, our three-dimensional (3D) models require lower neutrino luminosities to produce equally energetic explosions. We estimate that the convective engine in our models is 4% more efficient in 3D than in 2D. We propose that the greater efficiency of the convective engine found in 3D simulations might be due to the larger surface-to-volume ratio of convective plumes, which aids in distributing energy deposited by neutrinos. We do not find evidence of the standing accretion shock instability or turbulence being a key factor in powering the explosion in our models. Instead, the analysis of the energy transport in the post-shock region reveals characteristics of penetrative convection. The explosion energy decreases dramatically once the resolution is inadequate to capture the morphology of convection on large scales. This shows that the role of dimensionality is secondary to correctly accounting for the basic physics of the explosion. We also analyze information provided by particle tracers embedded in the flow and find that the unbound material has relatively long residency times in 2D models, while in 3D a significant fraction of the explosion energy is carried by particles with relatively short residency times.

  3. SU-E-T-567: A Three-Field Mono-Isocentric Inverse Treatment Planning Method for the Patients with Larger Breasts

    SciTech Connect (OSTI)

    Zhang, T; Marina, O; Chen, P; Teahan, M; Liu, Q; Benedetti, L

    2014-06-01

    Purpose: The purpose of this study is to develop a three-field monoisocentric inverse breast treatment planning technique without the use of half-beam block. Methods: Conventional three-field breast treatment with supraclavicular half-beam blocked requires two isocenters when the breast is too large to be contained within half-beam. The inferior border of the supraclavicular field and superior borders of the breast fields are matched on patient's skin with the light field. This method causes a large dose variation in the matching region due to daily setup uncertainties and requires a longer treatment setup time. We developed a three-field mono-isocentric planning method for the treatment of larger breasts. The three fields share the same isocenter located in the breast. Beam matching is achieved by rotating collimator, couch and gantry. Furthermore, we employed a mixed open-IMRT inverse optimization method to improve dose uniformity and coverage. Results: Perfect geometric beam matching was achieved by rotating couch, collimator and gantry together. Treatment setup time was significantly reduced without light-field matching during treatment deliveries. Inverse mixed open-IMRT optimization method achieved better dose uniformity and PTV coverage while keeping sufficient air flash to compensate setup and breast shape changes in daily treatments. Conclusion: By eliminating light field matching, the three-field mono-isocentric treatment method can significantly reduce setup time and uncertainty for large breast patients. Plan quality is further improved by inverse IMRT planning.

  4. Final Report for the "Fusion Application for Core-Edge Transport Simulations (FACETS)"

    SciTech Connect (OSTI)

    Cary, John R; Kruger, Scott

    2014-10-02

    The FACETS project over its lifetime developed the first self-consistent core-edge coupled capabilities, a new transport solver for modeling core transport in tokamak cores, developed a new code for modeling wall physics over long time scales, and significantly improved the capabilities and performance of legacy components, UEDGE, NUBEAM, GLF23, GYRO, and BOUT++. These improved capabilities leveraged the team’s expertise in applied mathematics (solvers and algorithms) and computer science (performance improvements and language interoperability). The project pioneered new methods for tackling the complexity of simulating the concomitant complexity of tokamak experiments.

  5. Experimental and Analytic Study on the Core Bypass Flow in a Very High Temperature Reactor

    SciTech Connect (OSTI)

    Richard Schultz

    2012-04-01

    Core bypass flow has been one of key issues in the very high temperature reactor (VHTR) design for securing core thermal margins and achieving target temperatures at the core exit. The bypass flow in a prismatic VHTR core occurs through the control element holes and the radial and axial gaps between the graphite blocks for manufacturing and refueling tolerances. These gaps vary with the core life cycles because of the irradiation swelling/shrinkage characteristic of the graphite blocks such as fuel and reflector blocks, which are main components of a core's structure. Thus, the core bypass flow occurs in a complicated multidimensional way. The accurate prediction of this bypass flow and counter-measures to minimize it are thus of major importance in assuring core thermal margins and securing higher core efficiency. Even with this importance, there has not been much effort in quantifying and accurately modeling the effect of the core bypass flow. The main objectives of this project were to generate experimental data for validating the software to be used to calculate the bypass flow in a prismatic VHTR core, validate thermofluid analysis tools and their model improvements, and identify and assess measures for reducing the bypass flow. To achieve these objectives, tasks were defined to (1) design and construct experiments to generate validation data for software analysis tools, (2) determine the experimental conditions and define the measurement requirements and techniques, (3) generate and analyze the experimental data, (4) validate and improve the thermofluid analysis tools, and (5) identify measures to control the bypass flow and assess its performance in the experiment.

  6. Core sampling system spare parts assessment

    SciTech Connect (OSTI)

    Walter, E.J.

    1995-04-04

    Soon, there will be 4 independent core sampling systems obtaining samples from the underground tanks. It is desirable that these systems be available for sampling during the next 2 years. This assessment was prepared to evaluate the adequacy of the spare parts identified for the core sampling system and to provide recommendations that may remediate overages or inadequacies of spare parts.

  7. Moving core beam energy absorber and converter

    DOE Patents [OSTI]

    Degtiarenko, Pavel V.

    2012-12-18

    A method and apparatus for the prevention of overheating of laser or particle beam impact zones through the use of a moving-in-the-coolant-flow arrangement for the energy absorbing core of the device. Moving of the core spreads the energy deposition in it in 1, 2, or 3 dimensions, thus increasing the effective cooling area of the device.

  8. Lateral restraint assembly for reactor core

    DOE Patents [OSTI]

    Gorholt, Wilhelm; Luci, Raymond K.

    1986-01-01

    A restraint assembly for use in restraining lateral movement of a reactor core relative to a reactor vessel wherein a plurality of restraint assemblies are interposed between the reactor core and the reactor vessel in circumferentially spaced relation about the core. Each lateral restraint assembly includes a face plate urged against the outer periphery of the core by a plurality of compression springs which enable radial preloading of outer reflector blocks about the core and resist low-level lateral motion of the core. A fixed radial key member cooperates with each face plate in a manner enabling vertical movement of the face plate relative to the key member but restraining movement of the face plate transverse to the key member in a plane transverse to the center axis of the core. In this manner, the key members which have their axes transverse to or subtending acute angles with the direction of a high energy force tending to move the core laterally relative to the reactor vessel restrain such lateral movement.

  9. Method and apparatus for recovering unstable cores

    DOE Patents [OSTI]

    McGuire, Patrick L. (Los Alamos, NM); Barraclough, Bruce L. (Los Alamos, NM)

    1983-01-01

    A method and apparatus suitable for stabilizing hydrocarbon cores are given. Such stabilized cores have not previously been obtainable for laboratory study, and such study is believed to be required before the hydrate reserves can become a utilizable resource. The apparatus can be built using commercially available parts and is very simple and safe to operate.

  10. seca-core-tech-prw-fl | netl.doe.gov

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

    SECA Core Technology Peer Review Workshop January 27-28, 2005 Table of Contents Disclaimer Participants [PDF-21.4KB] Papers and Presentations Fuel Processing Modeling and Simulation Power Electronics, Controls & Diagnostics Special Topics Electrodes Seals Interconnects Posters Peer Review Rating Results Summary [PDF-457KB] Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government or any agency

  11. Weak-interaction processes in core-collapse supernovae

    SciTech Connect (OSTI)

    Langanke, K.

    2015-02-24

    Weak interaction processes play an important role for the dynamics of a core-collapse supernova. Due to progress of nuclear modeling and constrained by data it has been possible to improve the rates of these processes for supernova conditions decisively. This manuscript describes the recent advances and the current status in deriving electron capture rates on nuclei and of inelastic neutrino-nucleus scattering for applications in supernova simulations and briefly discusses their impact on such studies.

  12. Magnetic nuclear core restraint and control

    DOE Patents [OSTI]

    Cooper, Martin H.

    1978-01-01

    A lateral restraint and control system for a nuclear reactor core adaptable to provide an inherent decrease of core reactivity in response to abnormally high reactor coolant fluid temperatures. An electromagnet is associated with structure for radially compressing the core during normal reactor conditions. A portion of the structures forming a magnetic circuit are composed of ferromagnetic material having a curie temperature corresponding to a selected coolant fluid temperature. Upon a selected signal, or inherently upon a preselected rise in coolant temperature, the magnetic force is decreased a given amount sufficient to relieve the compression force so as to allow core radial expansion. The expanded core configuration provides a decreased reactivity, tending to shut down the nuclear reaction.

  13. Magnetic nuclear core restraint and control

    DOE Patents [OSTI]

    Cooper, Martin H.

    1979-01-01

    A lateral restraint and control system for a nuclear reactor core adaptable to provide an inherent decrease of core reactivity in response to abnormally high reactor coolant fluid temperatures. An electromagnet is associated with structure for radially compressing the core during normal reactor conditions. A portion of the structures forming a magnetic circuit are composed of ferromagnetic material having a curie temperature corresponding to a selected coolant fluid temperature. Upon a selected signal, or inherently upon a preselected rise in coolant temperature, the magnetic force is decreased a given amount sufficient to relieve the compression force so as to allow core radial expansion. The expanded core configuration provides a decreased reactivity, tending to shut down the nuclear reaction.

  14. Chapter 13. Exploring Use of the Reserved Core

    SciTech Connect (OSTI)

    Holmen, John; Humphrey, Alan; Berzins, Martin

    2015-07-29

    In this chapter, we illustrate benefits of thinking in terms of thread management techniques when using a centralized scheduler model along with interoperability of MPI and PThread. This is facilitated through an exploration of thread placement strategies for an algorithm modeling radiative heat transfer with special attention to the 61st core. This algorithm plays a key role within the Uintah Computational Framework (UCF) and current efforts taking place at the University of Utah to model next-generation, large-scale clean coal boilers. In such simulations, this algorithm models the dominant form of heat transfer and consumes a large portion of compute time. Exemplified by a real-world example, this chapter presents our early efforts in porting a key portion of a scalability-centric codebase to the Intel Xeon Phi coprocessor. Specifically, this chapter presents results from our experiments profiling the native execution of a reverse Monte-Carlo ray tracing-based radiation model on a single coprocessor. These results demonstrate that our fastest run configurations utilized the 61st core and that performance was not profoundly impacted when explicitly oversubscribing the coprocessor operating system thread. Additionally, this chapter presents a portion of radiation model source code, a MIC-centric UCF cross-compilation example, and less conventional thread management technique for developers utilizing the PThreads threading model.

  15. Modeling

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

    Permalink Wind Generator Modeling Computational Modeling & Simulation, Energy, Energy Surety, Grid Integration, Infrastructure Security, Modeling, Modeling & Analysis, News, News & Events, Renewable Energy, SMART Grid, Systems Analysis, Transmission Grid Integration, Wind Energy Wind Generator Modeling This modular block diagram represents the major components of the generic dynamic wind turbine generator models. Model blocks and parameters are used to represent the different wind

  16. Solid core dipoles and switching power supplies: Lower cost light sources?

    SciTech Connect (OSTI)

    Benesch, Jay; Philip, Sarin

    2015-05-05

    As a result of improvements in power semiconductors, moderate frequency switching supplies can now provide the hundreds of amps typically required by accelerators with zero-to-peak noise in the kHz region ~ 0.06% in current or voltage mode. Modeling was undertaken using a finite electromagnetic program to determine if eddy currents induced in the solid steel of CEBAF magnets and small supplemental additions would bring the error fields down to the 5ppm level needed for beam quality. The expected maximum field of the magnet under consideration is 0.85 T and the DC current required to produce that field is used in the calculations. An additional 0.1% current ripple is added to the DC current at discrete frequencies 360 Hz, 720 Hz or 7200 Hz. Over the region of the pole within 0.5% of the central integrated BdL the resulting AC field changes can be reduced to less than 1% of the 0.1% input ripple for all frequencies, and a sixth of that at 7200 Hz. Doubling the current, providing 1.5 T central field, yielded the same fractional reduction in ripple at the beam for the cases checked. A small dipole was measured at 60, 120, 360 and 720 Hz in two conditions and the results compared to the larger model for the latter two frequencies with surprisingly good agreement. Thus, for light sources with aluminum vacuum vessels and full energy linac injection, the combination of solid core dipoles and switching power supplies may result in significant cost savings.

  17. Code dependencies of pre-supernova evolution and nucleosynthesis in massive stars: evolution to the end of core helium burning

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

    Jones, S.; Hirschi, R.; Pignatari, M.; Heger, A.; Georgy, C.; Nishimura, N.; Fryer, C.; Herwig, F.

    2015-01-15

    We present a comparison of 15M⊙ , 20M⊙ and 25M⊙ stellar models from three different codes|GENEC, KEPLER and MESA|and their nucleosynthetic yields. The models are calculated from the main sequence up to the pre-supernova (pre-SN) stage and do not include rotation. The GENEC and KEPLER models hold physics assumptions that are characteristic of the two codes. The MESA code is generally more flexible; overshooting of the convective core during the hydrogen and helium burning phases in MESA is chosen such that the CO core masses are consistent with those in the GENEC models. Full nucleosynthesis calculations are performed for allmore » models using the NuGrid post-processing tool MPPNP and the key energy-generating nuclear reaction rates are the same for all codes. We are thus able to highlight the key diferences between the models that are caused by the contrasting physics assumptions and numerical implementations of the three codes. A reasonable agreement is found between the surface abundances predicted by the models computed using the different codes, with GENEC exhibiting the strongest enrichment of H-burning products and KEPLER exhibiting the weakest. There are large variations in both the structure and composition of the models—the 15M⊙ and 20M⊙ in particular—at the pre-SN stage from code to code caused primarily by convective shell merging during the advanced stages. For example the C-shell abundances of O, Ne and Mg predicted by the three codes span one order of magnitude in the 15M⊙ models. For the alpha elements between Si and Fe the differences are even larger. The s-process abundances in the C shell are modified by the merging of convective shells; the modification is strongest in the 15M⊙ model in which the C-shell material is exposed to O-burning temperatures and the γ -process is activated. The variation in the s-process abundances across the codes is smallest in the 25M⊙ models, where it is comparable to the impact of nuclear reaction rate uncertainties. In general the differences in the results from the three codes are due to their contrasting physics assumptions (e.g. prescriptions for mass loss and convection). The broadly similar evolution of the 25M⊙ models gives us reassurance that different stellar evolution codes do produce similar results. For the 15M⊙ and 20M⊙ models, however, the different input physics and the interplay between the various convective zones lead to important differences in both the pre-supernova structure and nucleosynthesis predicted by the three codes. For the KEPLER models the core masses are different and therefore an exact match could not be expected.« less

  18. Sensitivity of IceCube-DeepCore to neutralino dark matter in the MSSM-25

    SciTech Connect (OSTI)

    Silverwood, Hamish; Adams, Jenni; Brown, Anthony M; Scott, Pat; Danninger, Matthias; Savage, Christopher; Edsj, Joakim; Hultqvist, Klas E-mail: patscott@physics.mcgill.ca E-mail: savage@physics.utah.edu E-mail: jenni.adams@canterbury.ac.nz E-mail: klas.hultqvist@fysik.su.se

    2013-03-01

    We analyse the sensitivity of IceCube-DeepCore to annihilation of neutralino dark matter in the solar core, generated within a 25 parameter version of the minimally supersymmetric standard model (MSSM-25). We explore the 25-dimensional parameter space using scanning methods based on importance sampling and using DarkSUSY 5.0.6 to calculate observables. Our scans produced a database of 6.02 million parameter space points with neutralino dark matter consistent with the relic density implied by WMAP 7-year data, as well as with accelerator searches. We performed a model exclusion analysis upon these points using the expected capabilities of the IceCube-DeepCore Neutrino Telescope. We show that IceCube-DeepCore will be sensitive to a number of models that are not accessible to direct detection experiments such as SIMPLE, COUPP and XENON100, indirect detection using Fermi-LAT observations of dwarf spheroidal galaxies, nor to current LHC searches.

  19. A NEW RECIPE FOR OBTAINING CENTRAL VOLUME DENSITIES OF PRESTELLAR CORES FROM SIZE MEASUREMENTS

    SciTech Connect (OSTI)

    Tassis, Konstantinos; Yorke, Harold W. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2011-07-10

    We propose a simple analytical method for estimating the central volume density of prestellar molecular cloud cores from their column density profiles. Prestellar cores feature a flat central part of the column density and volume density profiles of the same size indicating the existence of a uniform-density inner region. The size of this region is set by the thermal pressure force which depends only on the central volume density and temperature of the core, and can provide a direct measurement of the central volume density. Thus, a simple length measurement can immediately yield a central density estimate independent of any dynamical model for the core and without the need for fitting. Using the radius at which the column density is 90% of the central value as an estimate of the size of the flat inner part of the column density profile yields an estimate of the central volume density within a factor of two for well-resolved cores.

  20. THE ORIGIN OF COMPLEX ORGANIC MOLECULES IN PRESTELLAR CORES

    SciTech Connect (OSTI)

    Vastel, C.; Ceccarelli, C.; Lefloch, B.; Bachiller, R.

    2014-11-01

    Complex organic molecules (COMs) have been detected in a variety of environments including cold prestellar cores. Given the low temperatures of these objects, these detections challenge existing models. We report here new observations toward the prestellar core L1544. They are based on an unbiased spectral survey of the 3mm band at the IRAM 30m telescope as part of the Large Program ASAI. The observations allow us to provide a full census of the oxygen-bearing COMs in this source. We detected tricarbon monoxide, methanol, acetaldehyde, formic acid, ketene, and propyne with abundances varying from 5 10{sup 11} to 6 10{sup 9}. The non-LTE analysis of the methanol lines shows that they are likely emitted at the border of the core at a radius of ?8000 AU, where T ? 10K and n {sub H{sub 2}} ?2 10{sup 4}cm{sup 3}. Previous works have shown that water vapor is enhanced in the same region because of the photodesorption of water ices. We propose that a non-thermal desorption mechanism is also responsible for the observed emission of methanol and COMs from the same layer. The desorbed oxygen and a small amount of desorbed methanol and ethene are enough to reproduce the abundances of tricarbon monoxide, methanol, acetaldehyde, and ketene measured in L1544. These new findings open the possibility that COMs in prestellar cores originate in a similar outer layer rather than in the dense inner cores, as previously assumed, and that their formation is driven by the non-thermally desorbed species.

  1. Apparatus for controlling molten core debris. [LMFBR

    DOE Patents [OSTI]

    Golden, M.P.; Tilbrook, R.W.; Heylmun, N.F.

    1977-07-19

    Disclosed is an apparatus for containing, cooling, diluting, dispersing and maintaining subcritical the molten core debris assumed to melt through the bottom of a nuclear reactor pressure vessel in the unlikely event of a core meltdown. The apparatus is basically a sacrificial bed system which includes an inverted conical funnel, a core debris receptacle including a spherical dome, a spherically layered bed of primarily magnesia bricks, a cooling system of zig-zag piping in graphite blocks about and below the bed and a cylindrical liner surrounding the graphite blocks including a steel shell surrounded by firebrick. Tantalum absorber rods are used in the receptacle and bed. 9 claims, 22 figures.

  2. Apparatus for controlling molten core debris

    DOE Patents [OSTI]

    Golden, Martin P. [Trafford, PA; Tilbrook, Roger W. [Monroeville, PA; Heylmun, Neal F. [Pittsburgh, PA

    1977-07-19

    Apparatus for containing, cooling, diluting, dispersing and maintaining subcritical the molten core debris assumed to melt through the bottom of a nuclear reactor pressure vessel in the unlikely event of a core meltdown. The apparatus is basically a sacrificial bed system which includes an inverted conical funnel, a core debris receptacle including a spherical dome, a spherically layered bed of primarily magnesia bricks, a cooling system of zig-zag piping in graphite blocks about and below the bed and a cylindrical liner surrounding the graphite blocks including a steel shell surrounded by firebrick. Tantalum absorber rods are used in the receptacle and bed.

  3. Advances in HTGR fuel performance models

    SciTech Connect (OSTI)

    Stansfield, O.M.; Goodin, D.T.; Hanson, D.L.; Turner, R.F.

    1985-02-01

    Fuel performance models based on empirical evidence are used to predict particle failure and fission product release in the design of high-temperature gas-cooled reactors (HTGRs). Advances in HTGR fuel performance models have improved the agreement between observed and predicted performance and contributed to an enhanced position of the HTGR with regard to investment risk and passive safety. Heavy metal contamination is the source of about 55% of the circulating activity in the HTGR during normal operation, and the remainder comes primarily from particles which failed because of defective or missing buffer coatings. These failed particles make up about 5 x 10/sup -4/ fraction of the total core inventory. In addition to prediction of fuel performance during normal operation, the models are used to determine fuel failure and fission product release during core heat-up accident conditions. The mechanistic nature of the models, which incorporate all important failure modes, permits the prediction of performance from the relatively modest accident temperatures of a passively safe HTGR to the much more severe accident conditions of the larger 2240-MW(t) HTGR.

  4. Natural thorium isotopes in marine sediment core off Labuan port

    SciTech Connect (OSTI)

    Hafidz, B. Y.; Asnor, A. S.; Terence, R. C.; Mohamed, C. A. R.

    2014-02-12

    Sediment core was collected from Labuan port and analyzed to determine the radioactivity of thorium (Th) isotopes. The objectives of this study are to determine the possible sources of Th isotopes at Labuan port and estimates the sedimentation rate based on {sup 228}Th/{sup 232}Th model. The results suggest the {sup 230}Th and {sup 232}Th might be originated from terrestrial sedimentary rock while {sup 228}Th originated by authigenic origin. High ratio value of {sup 230}Th/{sup 232}Th detected at the top surface sediment indicates the increasing of {sup 230}Th at the recent years which might be contributed from the anthropogenic sources. The sedimentation rate of core sediment from Labuan Port was successfully estimated by using {sup 228}Th/{sup 232}Th model. The result show high sedimentation rate with 4.67 cm/year indicates rapid deposition occurred at this study area due to the high physical activity at the Labuan port. By assume the constant sedimentation rate at this area; we estimated the age of 142 cm core sediment obtained from Labuan port is 32 years started from 1981 to 2012. This chronology will be used in forthcoming research to investigate the historical profile of anthropogenic activities affecting the Labuan port.

  5. A dynamically collapsing core and a precursor of a core in a filament supported by turbulent and magnetic pressures

    SciTech Connect (OSTI)

    Furuya, Ray S.; Kitamura, Yoshimi; Shinnaga, Hiroko E-mail: kitamura@isas.jaxa.jp

    2014-10-01

    To study physical properties of the natal filament gas around the cloud core harboring an exceptionally young low-mass protostar GF 9-2, we carried out J = 1-0 line observations of {sup 12}CO, {sup 13}CO, and C{sup 18}O molecules using the Nobeyama 45 m telescope. The mapping area covers ? one-fifth of the whole filament. Our {sup 13}CO and C{sup 18}O maps clearly demonstrate that the core formed at the local density maxima of the filament, and the internal motions of the filament gas are totally governed by turbulence with Mach number of ?2. We estimated the scale height of the filament to be H = 0.3-0.7 pc, yielding the central density of n {sub c} = 800-4200 cm{sup 3}. Our analysis adopting an isothermal cylinder model shows that the filament is supported by the turbulent and magnetic pressures against the radial and axial collapse due to self-gravity. Since both the dissipation timescales of the turbulence and the transverse magnetic fields can be comparable to the free-fall time of the filament gas of 10{sup 6} yr, we conclude that the local decay of the supersonic turbulence and magnetic fields made the filament gas locally unstable, hence making the core collapse. Furthermore, we newly detected a gas condensation with velocity width enhancement to ?0.3 pc southwest of the GF 9-2 core. The condensation has a radius of ?0.15 pc and an LTE mass of ?5 M {sub ?}. Its internal motion is turbulent with Mach number of ?3, suggesting a gravitationally unbound state. Considering the uncertainties in our estimates, however, we propose that the condensation is a precursor of a cloud core, which would have been produced by the collision of the two gas components identified in the filament.

  6. Multiple network interface core apparatus and method

    DOE Patents [OSTI]

    Underwood, Keith D.; Hemmert, Karl Scott

    2011-04-26

    A network interface controller and network interface control method comprising providing a single integrated circuit as a network interface controller and employing a plurality of network interface cores on the single integrated circuit.

  7. Armor systems including coated core materials

    DOE Patents [OSTI]

    Chu, Henry S.; Lillo, Thomas M.; McHugh, Kevin M.

    2012-07-31

    An armor system and method involves providing a core material and a stream of atomized coating material that comprises a liquid fraction and a solid fraction. An initial layer is deposited on the core material by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is less than the liquid fraction of the stream of atomized coating material on a weight basis. An outer layer is then deposited on the initial layer by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is greater than the liquid fraction of the stream of atomized coating material on a weight basis.

  8. MODULAR CORE UNITS FOR A NEUTRONIC REACTOR

    DOE Patents [OSTI]

    Gage, J.F. Jr.; Sherer, D.B.

    1964-04-01

    A modular core unit for use in a nuclear reactor is described. Many identical core modules can be placed next to each other to make up a complete core. Such a module includes a cylinder of moderator material surrounding a fuel- containing re-entrant coolant channel. The re-entrant channel provides for the circulation of coolant such as liquid sodium from one end of the core unit, through the fuel region, and back out through the same end as it entered. Thermal insulation surrounds the moderator exterior wall inducing heat to travel inwardly to the coolant channel. Spaces between units may be used to accommodate control rods and support structure, which may be cooled by a secondary gas coolant, independently of the main coolant. (AEC)

  9. Armor systems including coated core materials

    DOE Patents [OSTI]

    2013-10-08

    An armor system and method involves providing a core material and a stream of atomized coating material that comprises a liquid fraction and a solid fraction. An initial layer is deposited on the core material by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is less than the liquid fraction of the stream of atomized coating material on a weight basis. An outer layer is then deposited on the initial layer by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is greater than the liquid fraction of the stream of atomized coating material on a weight basis.

  10. SoCore Energy | Open Energy Information

    Open Energy Info (EERE)

    SoCore Energy Place: Chicago, Illinois Zip: 60601 Sector: Solar Product: Chicago-based solar installer and mounting solution company that also arranges for solar loans and PPAs....

  11. VERA Core Physics Benchmark Progression Problems Specifications

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

    VERA Core Physics Benchmark Progression Problem Specifications Revision 4 August 29, 2014 Andrew T. Godfrey Physics Integration Oak Ridge National Laboratory CASL-U-2012-0131-004 VERA Core Physics Benchmark Problems Consortium for Advanced Simulation of LWRs ii CASL-U-2012-0131-004 Oak Ridge National Laboratory in partnership with Electric Power Research Institute Idaho National Laboratory Los Alamos National Laboratory Massachusetts Institute of Technology North Carolina State University Sandia

  12. Panelized wall system with foam core insulation

    DOE Patents [OSTI]

    Kosny, Jan; Gaskin, Sally

    2009-10-20

    A wall system includes a plurality of wall members, the wall members having a first metal panel, a second metal panel, and an insulating core between the first panel and the second panel. At least one of the first panel and the second panel include ridge portions. The insulating core can be a foam, such as a polyurethane foam. The foam can include at least one opacifier to improve the k-factor of the foam.

  13. Formed Core Sampler Hydraulic Conductivity Testing

    SciTech Connect (OSTI)

    Miller, D. H.; Reigel, M. M.

    2012-09-25

    A full-scale formed core sampler was designed and functionally tested for use in the Saltstone Disposal Facility (SDF). Savannah River National Laboratory (SRNL) was requested to compare properties of the formed core samples and core drilled samples taken from adjacent areas in the full-scale sampler. While several physical properties were evaluated, the primary property of interest was hydraulic conductivity. Differences in hydraulic conductivity between the samples from the formed core sampler and those representing the bulk material were noted with respect to the initial handling and storage of the samples. Due to testing conditions, the site port samples were exposed to uncontrolled temperature and humidity conditions prior to testing whereas the formed core samples were kept in sealed containers with minimal exposure to an uncontrolled environment prior to testing. Based on the results of the testing, no significant differences in porosity or density were found between the formed core samples and those representing the bulk material in the test stand.

  14. Solid oxide fuel cell having monolithic core

    DOE Patents [OSTI]

    Ackerman, J.P.; Young, J.E.

    1983-10-12

    A solid oxide fuel cell is described for electrochemically combining fuel and oxidant for generating galvanic output, wherein the cell core has an array of electrolyte and interconnect walls that are substantially devoid of any composite inert materials for support. Instead, the core is monolithic, where each electrolyte wall consists of thin layers of cathode and anode materials sandwiching a thin layer of electrolyte material therebetween. The electrolyte walls are arranged and backfolded between adjacent interconnect walls operable to define a plurality of core passageways alternately arranged where the inside faces thereof have only the anode material or only the cathode material exposed. Means direct the fuel to the anode-exposed core passageways and means direct the oxidant to the anode-exposed core passageways and means direct the oxidant to the cathode-exposed core passageway; and means also direct the galvanic output to an exterior circuit. Each layer of the electrolyte and interconnect materials is of the order of 0.002 to 0.01 cm thick; and each layer of the cathode and anode materials is of the order of 0.002 to 0.05 cm thick.

  15. TRENDS IN {sup 44}Ti AND {sup 56}Ni FROM CORE-COLLAPSE SUPERNOVAE (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect TRENDS IN {sup 44}Ti AND {sup 56}Ni FROM CORE-COLLAPSE SUPERNOVAE Citation Details In-Document Search Title: TRENDS IN {sup 44}Ti AND {sup 56}Ni FROM CORE-COLLAPSE SUPERNOVAE We compare the yields of {sup 44}Ti and {sup 56}Ni produced from post-processing the thermodynamic trajectories from three different core-collapse models-a Cassiopeia A progenitor, a double shock hypernova progenitor, and a rotating two-dimensional explosion-with the yields from exponential

  16. Characterization of trapped gas saturation and heterogeneity in core sampling using miscible-displacement experiments

    SciTech Connect (OSTI)

    Smith, D.H.; Jikich, S.A.

    1994-12-31

    Trapped gas saturation and permeability heterogeneity were evaluated in Berea cores at reservoir conditions, using standard miscible displacement experiments, with and without surfactants. Pressure and production history were influenced by core heterogeneity and foam lamellae formation when aqueous surfactant was present in the core. The objective of the dispersion-capacitance model was to estimate trapped gas saturations; however longitudinal dispersion and mass transfer also were examined. The results show that the dispersion-capacitance model accurately fits trapped gas saturation controlled by rock heterogeneities and foam lamellae for lamella generating mechanisms that allow a continuous gas phase (leave-behind lamellae). The practical applications resulting from this study can aid in core sample selection and scaling short laboratory corefloods to field dimensions for applications to foam stimulation and underground storage of natural gas.

  17. Probing Core-Hole Localization in Molecular Nitrogen

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

    Probing Core-Hole Localization in Molecular Nitrogen Probing Core-Hole Localization in Molecular Nitrogen Print Wednesday, 25 February 2009 00:00 The behavior of the core hole...

  18. TCEQ-CoreDataForm | Open Energy Information

    Open Energy Info (EERE)

    TCEQ-CoreDataForm Jump to: navigation, search OpenEI Reference LibraryAdd to library Form: TCEQ-CoreDataForm Abstract This is the core data form from the Texas Commission on...

  19. Characterization of trapped gas saturation and heterogeneity in core samples using miscible-displacement experiments

    SciTech Connect (OSTI)

    Smith, D.H.; Jikich, S.A.

    1994-12-31

    Trapped gas saturation and permeability heterogeneity were evaluated in Berea cores at reservoir conditions, using standard miscible displacement experiments, with and without surfactants. Pressure and production history were influenced by core heterogeneity and foam lamellae formation when aqueous surfactant was present in the core. A simple dispersion model and a three-coefficient dispersion-capacitance model (Coates-Smith) were fit to the experimental data. The dispersion-capacitance model successfully matched the experiments in which foam lamella formed, while the simple dispersion model was used only for determining initial core flow heterogeneity. The objective of the dispersion-capacitance model was to estimate trapped gas saturations; however longitudinal dispersion and mass transfer also were examined. The results show that the dispersion-capacitance model accurately fits trapped gas saturation controlled by rock heterogeneities and foam lamellae for lamella generating mechanisms that allow a continuous gas phase (leave-behind lamellae). The practical applications resulting from this study can aid in core sample selection and scaling short laboratory corefloods to field dimensions for applications to foam stimulation and underground storage of natural gas.

  20. Modifications to WRFs dynamical core to improve the treatment of moisture

    Office of Scientific and Technical Information (OSTI)

    for large-eddy simulations (Journal Article) | SciTech Connect WRFs dynamical core to improve the treatment of moisture for large-eddy simulations Citation Details In-Document Search Title: Modifications to WRFs dynamical core to improve the treatment of moisture for large-eddy simulations Yamaguchi and Feingold (2012) note that the cloud fields in their large-eddy simulations (LESs) of marine stratocumulus using the Weather Research and Forecasting (WRF) model exhibit a strong sensitivity

  1. Thermal-stress analysis of a Fort St. Vrain core-support block under accident conditions

    SciTech Connect (OSTI)

    Carruthers, L.M.; Butler, T.A.; Anderson, C.A.

    1982-01-01

    A thermoelastic stress analysis of a graphite core support block in the Fort St. Vrain High Temperature Gas Cooled Reactor is described. The support block is subjected to thermal stresses caused by a loss of forced circulation accident of the reactor system. Two- and three-dimensional finite element models of the core support block are analyzed using the ADINAT and ADINA codes, and results are given that verify the integrity of this structural component under the given accident condition.

  2. CASL - VERA-CS Coupled Multi-physics Capability demonstrated in a Full Core

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

    Simulation VERA-CS Coupled Multi-physics Capability demonstrated in a Full Core Simulation In December, CASL reported on the latest results from its Watts Bar reactor progression problem modeling. The most recent simulation includes quarter-core representation with coupled neutronics (including embedded cross section generation and neutron transport) and thermal - hydraulics. Last July, the team completed a demonstration of physics coupling that included heat generation and thermal-hydraulic

  3. DOE CYBER SECURITY EBK: MINIMUM CORE COMPETENCY TRAINING REQUIREMENTS...

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

    CYBER SECURITY EBK: MINIMUM CORE COMPETENCY TRAINING REQUIREMENTS DOE CYBER SECURITY EBK: MINIMUM CORE COMPETENCY TRAINING REQUIREMENTS puzzle-693870960720.jpg PDF icon DOE CYBER ...

  4. Core Holes At Blue Mountain Geothermal Area (Fairbank & Niggemann...

    Open Energy Info (EERE)

    Activity Details Location Blue Mountain Geothermal Area Exploration Technique Core Holes Activity Date 2002 - 2004 Usefulness useful DOE-funding Unknown Exploration Basis Cores...

  5. Annular Core Research Reactor at Sandia National Laboratories...

    National Nuclear Security Administration (NNSA)

    Jobs Apply for Our Jobs Our Jobs Working at NNSA Blog Home NNSA Blog Annular Core Research Reactor at Sandia National ... Annular Core Research Reactor at Sandia National...

  6. Core Lithology State of Hawail Scientific Observation Hole 2...

    Open Energy Info (EERE)

    core lithology descriptions for the core recovered from the SOH 2 borehole. Authors Elizabeth A. Novak, Frank A. Trusdell and Renee S. Evans Published Department of the Interior,...

  7. Core Analysis At Alum Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    Core Analysis At Alum Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Core Analysis At Alum Area (DOE GTP) Exploration Activity...

  8. Modifications to WRFs dynamical core to improve the treatment...

    Office of Scientific and Technical Information (OSTI)

    Modifications to WRFs dynamical core to improve the treatment of moisture for large-eddy simulations Citation Details In-Document Search Title: Modifications to WRFs dynamical core ...

  9. Modifications to WRF's dynamical core to improve the treatment...

    Office of Scientific and Technical Information (OSTI)

    dynamical core to improve the treatment of moisture for large--eddy simulations Citation Details In-Document Search Title: Modifications to WRF's dynamical core to improve the ...

  10. Resonant amplification of vortex-core oscillations by coherent...

    Office of Scientific and Technical Information (OSTI)

    Resonant amplification of vortex-core oscillations by coherent magnetic-field pulses Citation Details In-Document Search Title: Resonant amplification of vortex-core oscillations ...

  11. Modifications to WRFs dynamical core to improve the treatment...

    Office of Scientific and Technical Information (OSTI)

    Modifications to WRFs dynamical core to improve the treatment of moisture for large-eddy simulations Title: Modifications to WRFs dynamical core to improve the treatment of ...

  12. Core Carbon Group AS CCG | Open Energy Information

    Open Energy Info (EERE)

    Carbon Group AS CCG Jump to: navigation, search Name: Core Carbon Group AS (CCG) Place: Copenhagen, Denmark Zip: DK-1074 Sector: Carbon Product: The Core Carbon Group (formerly...

  13. X-ray and Neutron Scattering Study of the Formation of Core-Shell Type Polyoxometalates

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

    Yin, Panchao; Wu, Bin; Mamontov, Eugene; Daemen, Luke L; Cheng, Yongqiang; Hong, Kunlun; Bonnesen, Peter V; Keum, Jong Kahk; Ramirez-Cuesta, Anibal J

    2016-01-01

    A typical type of core-shell polyoxometalates can be obtained through the Keggin-type polyoxometalate-templated growth of a layer of spherical shell structure of {Mo72Fe30}. Small angle X-ray scattering is used to study the structural features and stability of the core-shell structures in aqueous solutions. Time-resolved small angle X-ray scattering is applied to monitor the synthetic reactions and a three-stage formation mechanism is proposed to describe the synthesis of the core-shell polyoxometalates based on the monitoring results. Quasi-elastic and inelastic neutron scattering are used to probe the dynamics of water molecules in the core-shell structures and two different types of water molecules,morethe confined and structured water, are observed. These water molecules play an important role in bridging core and shell structures and stabilizing the cluster structures.A typical type of core shell polyoxometalates can be obtained through the Keggin-type polyoxometalate-templated growth of a layer of spherical shell structure of {Mo72Fe30}. Small-angle X-ray scattering is used to study the structural features and stability of the core shell structures in aqueous solutions. Time-resolved small-angle X-ray scattering is applied to monitor the synthetic reactions, and a three-stage formation mechanism is proposed to describe the synthesis of the core shell polyoxometalates based on the monitoring results. New protocols have been developed by fitting the X-ray data with custom physical models, which provide more convincing, objective, and completed data interpretation. Quasi-elastic and inelastic neutron scattering are used to probe the dynamics of water molecules in the core shell structures, and two different types of water molecules, the confined and structured water, are observed. These water molecules play an important role in bridging core and shell structures and stabilizing the cluster structures.less

  14. Overview on Hydrate Coring, Handling and Analysis

    SciTech Connect (OSTI)

    Jon Burger; Deepak Gupta; Patrick Jacobs; John Shillinglaw

    2003-06-30

    Gas hydrates are crystalline, ice-like compounds of gas and water molecules that are formed under certain thermodynamic conditions. Hydrate deposits occur naturally within ocean sediments just below the sea floor at temperatures and pressures existing below about 500 meters water depth. Gas hydrate is also stable in conjunction with the permafrost in the Arctic. Most marine gas hydrate is formed of microbially generated gas. It binds huge amounts of methane into the sediments. Worldwide, gas hydrate is estimated to hold about 1016 kg of organic carbon in the form of methane (Kvenvolden et al., 1993). Gas hydrate is one of the fossil fuel resources that is yet untapped, but may play a major role in meeting the energy challenge of this century. In June 2002, Westport Technology Center was requested by the Department of Energy (DOE) to prepare a ''Best Practices Manual on Gas Hydrate Coring, Handling and Analysis'' under Award No. DE-FC26-02NT41327. The scope of the task was specifically targeted for coring sediments with hydrates in Alaska, the Gulf of Mexico (GOM) and from the present Ocean Drilling Program (ODP) drillship. The specific subjects under this scope were defined in 3 stages as follows: Stage 1: Collect information on coring sediments with hydrates, core handling, core preservation, sample transportation, analysis of the core, and long term preservation. Stage 2: Provide copies of the first draft to a list of experts and stakeholders designated by DOE. Stage 3: Produce a second draft of the manual with benefit of input from external review for delivery. The manual provides an overview of existing information available in the published literature and reports on coring, analysis, preservation and transport of gas hydrates for laboratory analysis as of June 2003. The manual was delivered as draft version 3 to the DOE Project Manager for distribution in July 2003. This Final Report is provided for records purposes.

  15. Studies of 3D-cloud optical depth from small to very large values, and of the radiation and remote sensing impacts of larger-drop clustering

    SciTech Connect (OSTI)

    2007-05-04

    We have basically completed all the goals stated in the previous proposal and published or submitted journal papers thereon, the only exception being First-Principles Monte Carlo which has taken more time than expected. We finally finished the comprehensive book on 3D cloud radiative transfer (edited by Marshak and Davis and published by Springer), with many contributions by ARM scientists; this book was highlighted in the 2005 ARM Annual Report. We have also completed (for now) our pioneering work on new models of cloud drop clustering based on ARM aircraft FSSP data, with applications both to radiative transfer and to rainfall. This clustering work was highlighted in the FY07 Our Changing Planet (annual report of the US Climate Change Science Program). Our group published 22 papers, one book, and 5 chapters in that book, during this proposal period. All are listed at the end of this section. Below, we give brief highlights of some of those papers.

  16. Power distributions in fresh and depleted LEU and HEU cores of the MITR reactor.

    SciTech Connect (OSTI)

    Wilson, E.H.; Horelik, N.E.; Dunn, F.E.; Newton, T.H., Jr.; Hu, L.; Stevens, J.G.

    2012-04-04

    The Massachusetts Institute of Technology Reactor (MITR-II) is a research reactor in Cambridge, Massachusetts designed primarily for experiments using neutron beam and in-core irradiation facilities. It delivers a neutron flux comparable to current LWR power reactors in a compact 6 MW core using Highly Enriched Uranium (HEU) fuel. In the framework of its non-proliferation policies, the international community presently aims to minimize the amount of nuclear material available that could be used for nuclear weapons. In this geopolitical context, most research and test reactors both domestic and international have started a program of conversion to the use of Low Enriched Uranium (LEU) fuel. A new type of LEU fuel based on an alloy of uranium and molybdenum (UMo) is expected to allow the conversion of U.S. domestic high performance reactors like the MITR-II reactor. Toward this goal, core geometry and power distributions are presented. Distributions of power are calculated for LEU cores depleted with MCODE using an MCNP5 Monte Carlo model. The MCNP5 HEU and LEU MITR models were previously compared to experimental benchmark data for the MITR-II. This same model was used with a finer spatial depletion in order to generate power distributions for the LEU cores. The objective of this work is to generate and characterize a series of fresh and depleted core peak power distributions, and provide a thermal hydraulic evaluation of the geometry which should be considered for subsequent thermal hydraulic safety analyses.

  17. Modeling

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

    PVLibMatlab Permalink Gallery Sandia Labs Releases New Version of PVLib Toolbox Modeling, News, Photovoltaic, Solar Sandia Labs Releases New Version of PVLib Toolbox Sandia has released version 1.3 of PVLib, its widely used Matlab toolbox for modeling photovoltaic (PV) power systems. The version 1.3 release includes the following added functions: functions to estimate parameters for popular PV module models, including PVsyst and the CEC '5 parameter' model a new model of the effects of solar

  18. Solid oxide fuel cell having monolithic core

    DOE Patents [OSTI]

    Ackerman, John P.; Young, John E.

    1984-01-01

    A solid oxide fuel cell for electrochemically combining fuel and oxidant for generating galvanic output, wherein the cell core has an array of electrolyte and interconnect walls that are substantially devoid of any composite inert materials for support. Instead, the core is monolithic, where each electrolyte wall consists of thin layers of cathode and anode materials sandwiching a thin layer of electrolyte material therebetween, and each interconnect wall consists of thin layers of the cathode and anode materials sandwiching a thin layer of interconnect material therebetween. The electrolyte walls are arranged and backfolded between adjacent interconnect walls operable to define a plurality of core passageways alternately arranged where the inside faces thereof have only the anode material or only the cathode material exposed. Means direct the fuel to the anode-exposed core passageways and means direct the oxidant to the cathode-exposed core passageway; and means also direct the galvanic output to an exterior circuit. Each layer of the electrolyte and interconnect materials is of the order of 0.002-0.01 cm thick; and each layer of the cathode and anode materials is of the order of 0.002-0.05 cm thick.

  19. Synthesis and optical study of green light emitting polymer coated CdSe/ZnSe core/shell nanocrystals

    SciTech Connect (OSTI)

    Tripathi, S.K.; Sharma, Mamta

    2013-05-15

    Highlights: ► Synthesis of Polymer coated core CdSe and CdSe/ZnSe core/shell NCs. ► From TEM image, the spherical nature of CdSe and CdSe/ZnSe is obtained. ► Exhibiting green band photoemission peak at 541 nm and 549 nm for CdSe core and CdSe/ZnSe core/shell NCs. ► The shell thickness has been calculated by using superposition of quantum confinement energy model. - Abstract: CdSe/ZnSe Core/Shell NCs dispersed in PVA are synthesized by chemical method at room temperature. This is characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV/Vis spectra and photoluminescence spectroscopy (PL). TEM image shows the spherical nature of CdSe/ZnSe core/shell NCs. The red shift of absorption and emission peak of CdSe/ZnSe core/shell NCs as compared to CdSe core confirmed the formation of core/shell. The superposition of quantum confinement energy model is used for calculation of thickness of ZnSe shell.

  20. NEUTRONIC REACTOR FUEL ELEMENT AND CORE SYSTEM

    DOE Patents [OSTI]

    Moore, W.T.

    1958-09-01

    This patent relates to neutronic reactors and in particular to an improved fuel element and a novel reactor core system for facilitating removal of contaminating fission products, as they are fermed, from association with the flssionable fuel, so as to mitigate the interferent effects of such fission products during reactor operation. The fuel elements are comprised of tubular members impervious to fluid and contatning on their interior surfaces a thin layer of fissionable material providing a central void. The core structure is comprised of a plurality of the tubular fuel elements arranged in parallel and a closed manifold connected to their ends. In the reactor the core structure is dispersed in a water moderator and coolant within a pressure vessel, and a means connected to said manifuld is provided for withdrawing and disposing of mobile fission product contamination from the interior of the feel tubes and manifold.

  1. NEUTRONIC REACTOR OPERATIONAL METHOD AND CORE SYSTEM

    DOE Patents [OSTI]

    Winters, C.E.; Graham, C.B.; Culver, J.S.; Wilson, R.H.

    1960-07-19

    Homogeneous neutronic reactor systems are described wherein an aqueous fuel solution is continuously circulated through a spherical core tank. The pumped fuel solution-is injected tangentially into the hollow spherical interior, thereby maintaining vigorous rotation of the solution within the tank in the form of a vortex; gaseous radiolytic decomposition products concentrate within the axial vortex cavity. The evolved gas is continuously discharged through a gas- outlet port registering with an extremity of the vortex cavity. and the solution stream is discharged through an annular liquid outlet port concentrically encircling the gas outlet by virtue of which the vortex and its cavity are maintained precisely axially aligned with the gas outlet. A primary heat exchanger extracts useful heat from the hot effluent fuel solution before its recirculation into the core tank. Hollow cylinders and other alternative core- tank configurations defining geometric volumes of revolution about a principal axis are also covered. AEC's Homogeneous Reactor Experiment No. 1 is a preferred embodiment.

  2. Nitride Stabilized Core-Shell Nanoparticles - Energy Innovation Portal

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

    Nitride Stabilized Core-Shell Nanoparticles Brookhaven National Laboratory Contact BNL About This Technology <br type="_moz" /> (A) Comparison of surface strain versus predicted binding energy of oxygen (BE-O) on the Pt<sub>2</sub>MLNi<sub>4</sub>N and Pt nanoparticle models with ~1.7 nm. (B) Pt specific activity against BE-O on PtNiN/C and Pt/C. (C) Schematic of the inner Pt diffusion process to the defective sites at the vertex during cycling in the

  3. A star harbouring a wormhole at its core

    SciTech Connect (OSTI)

    Dzhunushaliev, Vladimir; Folomeev, Vladimir; Kleihaus, Burkhard; Kunz, Jutta E-mail: vfolomeev@mail.ru E-mail: kunz@theorie.physik.uni-oldenburg.de

    2011-04-01

    We consider a configuration consisting of a wormhole filled by a perfect fluid. Such a model can be applied to describe stars as well as neutron stars with a nontrivial topology. The presence of a tunnel allows for motion of the fluid, including oscillations near the core of the system. Choosing the polytropic equation of state for the perfect fluid, we obtain static regular solutions. Based on these solutions, we consider small radial oscillations of the configuration and show that the solutions are stable with respect to linear perturbations in the external region.

  4. Modeling

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

    Engine Combustion/Modeling Modelingadmin2015-10-28T01:54:52+00:00 Modelers at the CRF are developing high-fidelity simulation tools for engine combustion and detailed micro-kinetic, surface chemistry modeling tools for catalyst-based exhaust aftertreatment systems. The engine combustion modeling is focused on developing Large Eddy Simulation (LES). LES is being used with closely coupled key target experiments to reveal new understanding of the fundamental processes involved in engine combustion

  5. Modeling

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

    Reacting Flow/Modeling Modelingadmin2015-10-28T02:39:13+00:00 Turbulence models typically involve coarse-graining and/or time averaging. Though adequate for modeling mean transport, this approach does not address turbulence-microphysics interactions that are important in combustion processes. Subgrid models are developed to represent these interactions. The CRF has developed a fundamentally different representation of these interactions that does not involve distinct coarse-grained and subgrid

  6. Framework Application for Core Edge Transport Simulation (FACETS)

    SciTech Connect (OSTI)

    Krasheninnikov, Sergei; Pigarov, Alexander

    2011-10-15

    The FACETS (Framework Application for Core-Edge Transport Simulations) project of Scientific Discovery through Advanced Computing (SciDAC) Program was aimed at providing a high-fidelity whole-tokamak modeling for the U.S. magnetic fusion energy program and ITER through coupling separate components for each of the core region, edge region, and wall, with realistic plasma particles and power sources and turbulent transport simulation. The project also aimed at developing advanced numerical algorithms, efficient implicit coupling methods, and software tools utilizing the leadership class computing facilities under Advanced Scientific Computing Research (ASCR). The FACETS project was conducted by a multi-discipline, multi-institutional teams, the Lead PI was J.R. Cary (Tech-X Corp.). In the FACETS project, the Applied Plasma Theory Group at the MAE Department of UCSD developed the Wall and Plasma-Surface Interaction (WALLPSI) module, performed its validation against experimental data, and integrated it into the developed framework. WALLPSI is a one-dimensional, coarse grained, reaction/advection/diffusion code applied to each material boundary cell in the common modeling domain for a tokamak. It incorporates an advanced model for plasma particle transport and retention in the solid matter of plasma facing components, simulation of plasma heat power load handling, calculation of erosion/deposition, and simulation of synergistic effects in strong plasma-wall coupling.

  7. Neutronics Analyses of the Minimum Original HEU TREAT Core

    SciTech Connect (OSTI)

    Kontogeorgakos, D.; Connaway, H.; Yesilyurt, G.; Wright, A.

    2014-04-01

    This work was performed to support the feasibility study on the potential conversion of the Transient Reactor Test Facility (TREAT) at Idaho National Laboratory from the use of high-enriched uranium (HEU) fuel to the use of low-enriched uranium (LEU) fuel. The analyses were performed by the GTRI Reactor Conversion staff at the Argonne National Laboratory (ANL). The objective of this study was to validate the MCNP model of the TREAT reactor with the well-documented measurements which were taken during the start-up and early operation of TREAT. Furthermore, the effect of carbon graphitization was also addressed. The graphitization level was assumed to be 100% (ANL/GTRI/TM-13/4). For this purpose, a set of experiments was chosen to validate the TREAT MCNP model, involving the approach to criticality procedure, in-core neutron flux measurements with foils, and isothermal temperature coefficient and temperature distribution measurements. The results of this study extended the knowledge base for the TREAT MCNP calculations and established the credibility of the MCNP model to be used in the core conversion feasibility analysis.

  8. Apparatus for controlling nuclear core debris

    DOE Patents [OSTI]

    Jones, Robert D.

    1978-01-01

    Nuclear reactor apparatus for containing, cooling, and dispersing reactor debris assumed to flow from the core area in the unlikely event of an accident causing core meltdown. The apparatus includes a plurality of horizontally disposed vertically spaced plates, having depressions to contain debris in controlled amounts, and a plurality of holes therein which provide natural circulation cooling and a path for debris to continue flowing downward to the plate beneath. The uppermost plates may also include generally vertical sections which form annular-like flow areas which assist the natural circulation cooling.

  9. DOE CYBER SECURITY EBK: CORE COMPETENCY TRAINING REQUIREMENTS: CA

    Broader source: Energy.gov [DOE]

    DOE CYBER SECURITY EBK: CORE COMPETENCY TRAINING REQUIREMENTS. Key Cyber Security Role: Certification Agent (CA)

  10. Requirements for transporting the TMI-2 core

    SciTech Connect (OSTI)

    Wilkins, D.E.

    1983-08-01

    This report summarizes the requirements associated with the actual transport of core debris from the damaged Three Mile Island Unit 2 reactor to the Idaho National Engineering Laboratory. The requirements are discussed under six headings: accountability, security, quality, safety, environment, and transportation.

  11. ON-SITE RESEARCH CORE COMPETENCIES

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

    Core Competencies Engineering Solutions using an Integrated Approach Computational Science Functional Materials Predictive Geosciences Energy Process Innovation Materials Characterization Structural Materials Engineered Natural Systems Molecular Science Thermal Sciences Computational Science & Engineering Specific Expertise: Multiphase Flow, Multi-scale Simulation & Optimization, Simulation, Data Analysis & Vizualization NETL's Computational Science and Engineering competency

  12. Container Security - part of the CORE system

    Energy Science and Technology Software Center (OSTI)

    2009-10-02

    A data integration system to support the US Customs and Border Protection Officers to supervise and make decisions for container inspections. CORE is designed to act as a framework to bridge the gaps between disparate data integration and delivery of disparate information visualization.

  13. Parallel Access of Out-Of-Core Dense Extendible Arrays

    SciTech Connect (OSTI)

    Otoo, Ekow J; Rotem, Doron

    2007-07-26

    Datasets used in scientific and engineering applications are often modeled as dense multi-dimensional arrays. For very large datasets, the corresponding array models are typically stored out-of-core as array files. The array elements are mapped onto linear consecutive locations that correspond to the linear ordering of the multi-dimensional indices. Two conventional mappings used are the row-major order and the column-major order of multi-dimensional arrays. Such conventional mappings of dense array files highly limit the performance of applications and the extendibility of the dataset. Firstly, an array file that is organized in say row-major order causes applications that subsequently access the data in column-major order, to have abysmal performance. Secondly, any subsequent expansion of the array file is limited to only one dimension. Expansions of such out-of-core conventional arrays along arbitrary dimensions, require storage reorganization that can be very expensive. Wepresent a solution for storing out-of-core dense extendible arrays that resolve the two limitations. The method uses a mapping function F*(), together with information maintained in axial vectors, to compute the linear address of an extendible array element when passed its k-dimensional index. We also give the inverse function, F-1*() for deriving the k-dimensional index when given the linear address. We show how the mapping function, in combination with MPI-IO and a parallel file system, allows for the growth of the extendible array without reorganization and no significant performance degradation of applications accessing elements in any desired order. We give methods for reading and writing sub-arrays into and out of parallel applications that run on a cluster of workstations. The axial-vectors are replicated and maintained in each node that accesses sub-array elements.

  14. Modeling

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

    WVMinputs-outputs Permalink Gallery Sandia Labs releases wavelet variability model (WVM) Modeling, News, Photovoltaic, Solar Sandia Labs releases wavelet variability model (WVM) When a single solar photovoltaic (PV) module is in full sunlight, then is shaded by a cloud, and is back in full sunlight in a matter of seconds, a sharp dip then increase in power output will result. However, over an entire PV plant, clouds will often uncover some modules even as they cover others, [...] By Andrea

  15. Modeling

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

    A rail tank car of the type used to transport crude oil across North America. Recent incidents have raised concerns about the safety of this practice, which the DOE-DOT-sponsored team is investigating. (photo credit: Harvey Henkelmann) Permalink Gallery Expansion of DOE-DOT Tight Oil Research Work Capabilities, Carbon Capture & Storage, Carbon Storage, Energy, Energy Assurance, Energy Assurance, Fuel Options, Infrastructure Assurance, Infrastructure Security, Modeling, Modeling, Modeling

  16. Modeling

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

    Monte Carlo modeling it was found that for noisy signals with a significant background component, accuracy is improved by fitting the total emission data which includes the...

  17. Modeling

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

    ... Renewable Energy, Research & Capabilities, Wind Energy, Wind News|0 Comments Read More ... Energy, Research & Capabilities, Water Power Sandia Modifies Delft3D Turbine Model ...

  18. In-core and ex-core calculations of the VENUS simulated PWR benchmark experiment

    SciTech Connect (OSTI)

    Williams, M.L.; Chowdhury, P.; Landesman, M.; Kam, F.B.K.

    1985-01-01

    The VENUS PWR engineering mockup experiment was established to simulate a beginning-of-life, generic PWR configuration at the zero-power VENUS critical facility located at CEN/SCK, Mol, Belgium. The experimental measurement program consists of (1) gamma scans to determine the core power distribution, (2) in-core and ex-core foil activations, (3) neutron spectrometer measurements, and (4) gamma heating measurements with TLD's. Analysis of the VENUS benchmark has been performed with two-dimensional discrete ordinates transport theory, using the DOT-IV code.

  19. The LASS (Larger Aperture Superconducting Solenoid) spectrometer

    SciTech Connect (OSTI)

    Aston, D.; Awaji, N.; Barnett, B.; Bienz, T.; Bierce, R.; Bird, F.; Bird, L.; Blockus, D.; Carnegie, R.K.; Chien, C.Y.

    1986-04-01

    LASS is the acronym for the Large Aperture Superconducting Solenoid spectrometer which is located in an rf-separated hadron beam at the Stanford Linear Accelerator Center. This spectrometer was constructed in order to perform high statistics studies of multiparticle final states produced in hadron reactions. Such reactions are frequently characterized by events having complicated topologies and/or relatively high particle multiplicity. Their detailed study requires a spectrometer which can provide good resolution in momentum and position over almost the entire solid angle subtended by the production point. In addition, good final state particle identification must be available so that separation of the many kinematically-overlapping final states can be achieved. Precise analyses of the individual reaction channels require high statistics, so that the spectrometer must be capable of high data-taking rates in order that such samples can be acquired in a reasonable running time. Finally, the spectrometer must be complemented by a sophisticated off-line analysis package which efficiently finds tracks, recognizes and fits event topologies and correctly associates the available particle identification information. This, together with complicated programs which perform specific analysis tasks such as partial wave analysis, requires a great deal of software effort allied to a very large computing capacity. This paper describes the construction and performance of the LASS spectrometer, which is an attempt to realize the features just discussed. The configuration of the spectrometer corresponds to the data-taking on K and K interactions in hydrogen at 11 GeV/c which took place in 1981 and 1982. This constitutes a major upgrade of the configuration used to acquire lower statistics data on 11 GeV/c K p interactions during 1977 and 1978, which is also described briefly.

  20. Sabourov_2006 (much larger file).pdf

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

    ... We therefore recommend that the CRC theory not but used to extrapolate the S factor to ... P. Oblozhinsky, V. Plujko, and P. Young. Handbook for calculations of nuclear reaction ...

  1. From detonation to diapers: Los Alamos computer codes at core of advanced

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

    manufacturing tools From detonation to diapers Los Alamos computer codes at core of advanced manufacturing tools The computer codes used for predictive fluid modeling are part of the Los Alamos Computational Fluid Dynamics Library. July 27, 2011 This simulation of a droplet of liquid falling into a pool of liquid was modeled using Los Alamos National Laboratory's Computational Fluid Dynamics Library This simulation of a droplet of liquid falling into a pool of liquid was modeled using Los

  2. Modeling

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

    NASA Earth at Night Video EC, Energy, Energy Efficiency, Global, Modeling, News & Events, Solid-State Lighting, Videos NASA Earth at Night Video Have you ever wondered what the ...

  3. Carbon-Supported IrNi Core-Shell Nanoparticles: Synthesis Characterization and Catalytic Activity

    SciTech Connect (OSTI)

    K Sasaki; K Kuttiyiel; L Barrio; D Su; A Frenkel; N Marinkovic; D Mahajan; R Adzic

    2011-12-31

    We synthesized carbon-supported IrNi core-shell nanoparticles by chemical reduction and subsequent thermal annealing in H{sub 2}, and verified the formation of Ir shells on IrNi solid solution alloy cores by various experimental methods. The EXAFS analysis is consistent with the model wherein the IrNi nanoparticles are composed of two-layer Ir shells and IrNi alloy cores. In situ XAS revealed that the Ir shells completely protect Ni atoms in the cores from oxidation or dissolution in an acid electrolyte under elevated potentials. The formation of Ir shell during annealing due to thermal segregation is monitored by time-resolved synchrotron XRD measurements, coupled with Rietveld refinement analyses. The H{sub 2} oxidation activity of the IrNi nanoparticles was found to be higher than that of a commercial Pt/C catalyst. This is predominantly due to Ni-core-induced Ir shell contraction that makes the surface less reactive for IrOH formation, and the resulting more metallic Ir surface becomes more active for H{sub 2} oxidation. This new class of core-shell nanoparticles appears promising for application as hydrogen anode fuel cell electrocatalysts.

  4. PWR core design, neutronics evaluation and fuel cycle analysis for thorium-uranium breeding recycle

    SciTech Connect (OSTI)

    Bi, G.; Liu, C.; Si, S.

    2012-07-01

    This paper was focused on core design, neutronics evaluation and fuel cycle analysis for Thorium-Uranium Breeding Recycle in current PWRs, without any major change to the fuel lattice and the core internals, but substituting the UOX pellet with Thorium-based pellet. The fuel cycle analysis indicates that Thorium-Uranium Breeding Recycle is technically feasible in current PWRs. A 4-loop, 193-assembly PWR core utilizing 17 x 17 fuel assemblies (FAs) was taken as the model core. Two mixed cores were investigated respectively loaded with mixed reactor grade Plutonium-Thorium (PuThOX) FAs and mixed reactor grade {sup 233}U-Thorium (U{sub 3}ThOX) FAs on the basis of reference full Uranium oxide (UOX) equilibrium-cycle core. The UOX/PuThOX mixed core consists of 121 UOX FAs and 72 PuThOX FAs. The reactor grade {sup 233}U extracted from burnt PuThOX fuel was used to fabrication of U{sub 3}ThOX for starting Thorium-. Uranium breeding recycle. In UOX/U{sub 3}ThOX mixed core, the well designed U{sub 3}ThOX FAs with 1.94 w/o fissile uranium (mainly {sup 233}U) were located on the periphery of core as a blanket region. U{sub 3}ThOX FAs remained in-core for 6 cycles with the discharged burnup achieving 28 GWD/tHM. Compared with initially loading, the fissile material inventory in U{sub 3}ThOX fuel has increased by 7% via 1-year cooling after discharge. 157 UOX fuel assemblies were located in the inner of UOX/U{sub 3}ThOX mixed core refueling with 64 FAs at each cycle. The designed UOX/PuThOX and UOX/U{sub 3}ThOX mixed core satisfied related nuclear design criteria. The full core performance analyses have shown that mixed core with PuThOX loading has similar impacts as MOX on several neutronic characteristic parameters, such as reduced differential boron worth, higher critical boron concentration, more negative moderator temperature coefficient, reduced control rod worth, reduced shutdown margin, etc.; while mixed core with U{sub 3}ThOX loading on the periphery of core has no visible impacts on neutronic characteristics compared with reference full UOX core. The fuel cycle analysis has shown that {sup 233}U mono-recycling with U{sub 3}ThOX fuel could save 13% of natural uranium resource compared with UOX once through fuel cycle, slightly more than that of Plutonium single-recycling with MOX fuel. If {sup 233}U multi-recycling with U{sub 3}ThOX fuel is implemented, more natural uranium resource would be saved. (authors)

  5. Resilient Core Networks for Energy Distribution

    SciTech Connect (OSTI)

    Kuntze, Nicolai; Rudolph, Carsten; Leivesley, Sally; Manz, David O.; Endicott-Popovsky, Barbara E.

    2014-07-28

    Abstract—Substations and their control are crucial for the availability of electricity in today’s energy distribution. Ad- vanced energy grids with Distributed Energy Resources require higher complexity in substations, distributed functionality and communication between devices inside substations and between substations. Also, substations include more and more intelligent devices and ICT based systems. All these devices are connected to other systems by different types of communication links or are situated in uncontrolled environments. Therefore, the risk of ICT based attacks on energy grids is growing. Consequently, security measures to counter these risks need to be an intrinsic part of energy grids. This paper introduces the concept of a Resilient Core Network to interconnected substations. This core network provides essen- tial security features, enables fast detection of attacks and allows for a distributed and autonomous mitigation of ICT based risks.

  6. Mox fuel arrangement for nuclear core

    DOE Patents [OSTI]

    Kantrowitz, Mark L.; Rosenstein, Richard G.

    2001-05-15

    In order to use up a stockpile of weapons-grade plutonium, the plutonium is converted into a mixed oxide (MOX) fuel form wherein it can be disposed in a plurality of different fuel assembly types. Depending on the equilibrium cycle that is required, a predetermined number of one or more of the fuel assembly types are selected and arranged in the core of the reactor in accordance with a selected loading schedule. Each of the fuel assemblies is designed to produce different combustion characteristics whereby the appropriate selection and disposition in the core enables the resulting equilibrium cycle to closely resemble that which is produced using urania fuel. The arrangement of the MOX rods and burnable absorber rods within each of the fuel assemblies, in combination with a selective control of the amount of plutonium which is contained in each of the MOX rods, is used to tailor the combustion. characteristics of the assembly.

  7. MOX fuel arrangement for nuclear core

    DOE Patents [OSTI]

    Kantrowitz, Mark L.; Rosenstein, Richard G.

    1998-01-01

    In order to use up a stockpile of weapons-grade plutonium, the plutonium is converted into a mixed oxide (MOX) fuel form wherein it can be disposed in a plurality of different fuel assembly types. Depending on the equilibrium cycle that is required, a predetermined number of one or more of the fuel assembly types are selected and arranged in the core of the reactor in accordance with a selected loading schedule. Each of the fuel assemblies is designed to produce different combustion characteristics whereby the appropriate selection and disposition in the core enables the resulting equilibrium cycle to closely resemble that which is produced using urania fuel. The arrangement of the MOX rods and burnable absorber rods within each of the fuel assemblies, in combination with a selective control of the amount of plutonium which is contained in each of the MOX rods, is used to tailor the combustion characteristics of the assembly.

  8. MOX fuel arrangement for nuclear core

    DOE Patents [OSTI]

    Kantrowitz, Mark L.; Rosenstein, Richard G.

    2001-07-17

    In order to use up a stockpile of weapons-grade plutonium, the plutonium is converted into a mixed oxide (MOX) fuel form wherein it can be disposed in a plurality of different fuel assembly types. Depending on the equilibrium cycle that is required, a predetermined number of one or more of the fuel assembly types are selected and arranged in the core of the reactor in accordance with a selected loading schedule. Each of the fuel assemblies is designed to produce different combustion characteristics whereby the appropriate selection and disposition in the core enables the resulting equilibrium cycle to closely resemble that which is produced using urania fuel. The arrangement of the MOX rods and burnable absorber rods within each of the fuel assemblies, in combination with a selective control of the amount of plutonium which is contained in each of the MOX rods, is used to tailor the combustion characteristics of the assembly.

  9. MOX fuel arrangement for nuclear core

    DOE Patents [OSTI]

    Kantrowitz, M.L.; Rosenstein, R.G.

    1998-10-13

    In order to use up a stockpile of weapons-grade plutonium, the plutonium is converted into a mixed oxide (MOX) fuel form wherein it can be disposed in a plurality of different fuel assembly types. Depending on the equilibrium cycle that is required, a predetermined number of one or more of the fuel assembly types are selected and arranged in the core of the reactor in accordance with a selected loading schedule. Each of the fuel assemblies is designed to produce different combustion characteristics whereby the appropriate selection and disposition in the core enables the resulting equilibrium cycle to closely resemble that which is produced using urania fuel. The arrangement of the MOX rods and burnable absorber rods within each of the fuel assemblies, in combination with a selective control of the amount of plutonium which is contained in each of the MOX rods, is used to tailor the combustion characteristics of the assembly. 38 figs.

  10. CT Scans of Cores Metadata, Barrow, Alaska 2015

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Katie McKnight; Tim Kneafsey; Craig Ulrich

    2015-03-11

    Individual ice cores were collected from Barrow Environmental Observatory in Barrow, Alaska, throughout 2013 and 2014. Cores were drilled along different transects to sample polygonal features (i.e. the trough, center and rim of high, transitional and low center polygons). Most cores were drilled around 1 meter in depth and a few deep cores were drilled around 3 meters in depth. Three-dimensional images of the frozen cores were constructed using a medical X-ray computed tomography (CT) scanner. TIFF files can be uploaded to ImageJ (an open-source imaging software) to examine soil structure and densities within each core.

  11. PRESSURIZED WATER REACTOR CORE WITH PLUTONIUM BURNUP

    DOE Patents [OSTI]

    Puechl, K.H.

    1963-09-24

    A pressurized water reactor is described having a core containing Pu/sup 240/ in which the effective microscopic neutronabsorption cross section of Pu/sup 240/ in unconverted condition decreases as the time of operation of the reactor increases, in order to compensate for loss of reactivity resulting from fission product buildup during reactor operation. This means serves to improve the efficiency of the reactor operation by reducing power losses resulting from control rods and burnable poisons. (AEC)

  12. DOE GIS core team - a best practice

    SciTech Connect (OSTI)

    Bollinger, J.; Bhaduri, Budhendra; Bleakly, D. R.; Brady-Sabeff, Liz; Guber, Al; Guziel, K. A.; Hargrove, Susan; Lee, J.; Lee, R.; Mickus, Kurt; Morehouse, David; Moore, K.; Ramsdell, Amy; Rich, P. M.

    2004-01-01

    Large government organizations such as the Department of Energy (DOE) are challenged with identifying and implementing best geospatial information management practices to ensure that operational needs are met and government objectives are achieved. Geographic Information System (GIS) professionals, complex wide within the Department, conduct spatial information management practices on a daily basis to complete a wide variety of science and engineering tasks. The DOE Office of the CIO recognized the wealth of geospatial information management knowledge within the DOE complex and formed the DOE GIS Core Team in 2001 as a result. The team is comprised of GIS experts-representing all major DOE labs, site facilities, and programs-who volunteer their time to address issues impacting the entire complex. These include the President's management agenda (with emphasis on the Geospatial One-Stop), homeland security, emergency response, site management, software and geospatial data licensing, and federal, national, and international standards governing the creation and dissemination of geospatial data. The strength of the DOE GIS Core Team is the wide diversity of GIS and scientific expertise represented on the team, which allows it to provide the DOE CIO's office with sound guidance on complex wide issues from a GIS practitioner's perspective. The Core Team's mission is 'to foster technical excellence and communication, to identify and advocate best business practices, and to provide sound recommendations on policy and standards.' As a first step toward identifying best practices the feam conducted a survey of all known GIS assets across the DOE complex. The survey identified each site's GIS expertise, operating systems architecture and software applications, major project areas supported, and a number of other metrics important to the operation of a GIS organization. Results of the survey will be discussed, along with the mission of the Core Team. A broad overview of best practices utilized by many of the leading GIS organizations across the complex will also be provided.

  13. Validation of HELIOS for ATR Core Follow Analyses

    SciTech Connect (OSTI)

    Bays, Samuel E.; Swain, Emily T.; Crawford, Douglas S.; Nigg, David W.

    2015-03-01

    This work summarizes the validation analyses for the HELIOS code to support core design and safety assurance calculations of the Advanced Test Reactor (ATR). Past and current core safety assurance is performed by the PDQ-7 diffusion code; a state of the art reactor physics simulation tool from the nuclear industry’s earlier days. Over the past twenty years, improvements in computational speed have enabled the use of modern neutron transport methodologies to replace the role of diffusion theory for simulation of complex systems, such as the ATR. More exact methodologies have enabled a paradigm-shift away from highly tuned codes that force compliance with a bounding safety envelope, and towards codes regularly validated against routine measurements. To validate HELIOS, the 16 ATR operational cycles from late-2009 to present were modeled. The computed power distribution was compared against data collected by the ATR’s on-line power surveillance system. It was found that the ATR’s lobe-powers could be determined with ±10% accuracy. Also, the ATR’s cold startup shim configuration for each of these 16 cycles was estimated and compared against the reported critical position from the reactor log-book. HELIOS successfully predicted criticality within the tolerance set by the ATR startup procedure for 13 out of the 16 cycles. This is compared to 12 times for PDQ (without empirical adjustment). These findings, as well as other insights discussed in this report, suggest that HELIOS is highly suited for replacing PDQ for core safety assurance of the ATR. Furthermore, a modern verification and validation framework has been established that allows reactor and fuel performance data to be computed with a known degree of accuracy and stated uncertainty.

  14. ZPR-6 assembly 7 high {sup 240}Pu core experiments : a fast reactor core with mixed (Pu,U)-oxide fuel and a centeral high{sup 240}Pu zone.

    SciTech Connect (OSTI)

    Lell, R. M.; Morman, J. A.; Schaefer, R.W.; McKnight, R.D.; Nuclear Engineering Division

    2009-02-23

    ZPR-6 Assembly 7 (ZPR-6/7) encompasses a series of experiments performed at the ZPR-6 facility at Argonne National Laboratory in 1970 and 1971 as part of the Demonstration Reactor Benchmark Program (Reference 1). Assembly 7 simulated a large sodium-cooled LMFBR with mixed oxide fuel, depleted uranium radial and axial blankets, and a core H/D near unity. ZPR-6/7 was designed to test fast reactor physics data and methods, so configurations in the Assembly 7 program were as simple as possible in terms of geometry and composition. ZPR-6/7 had a very uniform core assembled from small plates of depleted uranium, sodium, iron oxide, U{sub 3}O{sub 8} and Pu-U-Mo alloy loaded into stainless steel drawers. The steel drawers were placed in square stainless steel tubes in the two halves of a split table machine. ZPR-6/7 had a simple, symmetric core unit cell whose neutronic characteristics were dominated by plutonium and {sup 238}U. The core was surrounded by thick radial and axial regions of depleted uranium to simulate radial and axial blankets and to isolate the core from the surrounding room. The ZPR-6/7 program encompassed 139 separate core loadings which include the initial approach to critical and all subsequent core loading changes required to perform specific experiments and measurements. In this context a loading refers to a particular configuration of fueled drawers, radial blanket drawers and experimental equipment (if present) in the matrix of steel tubes. Two principal core configurations were established. The uniform core (Loadings 1-84) had a relatively uniform core composition. The high {sup 240}Pu core (Loadings 85-139) was a variant on the uniform core. The plutonium in the Pu-U-Mo fuel plates in the uniform core contains 11% {sup 240}Pu. In the high {sup 240}Pu core, all Pu-U-Mo plates in the inner core region (central 61 matrix locations per half of the split table machine) were replaced by Pu-U-Mo plates containing 27% {sup 240}Pu in the plutonium component to construct a central core zone with a composition closer to that in an LMFBR core with high burnup. The high {sup 240}Pu configuration was constructed for two reasons. First, the composition of the high {sup 240}Pu zone more closely matched the composition of LMFBR cores anticipated in design work in 1970. Second, comparison of measurements in the ZPR-6/7 uniform core with corresponding measurements in the high {sup 240}Pu zone provided an assessment of some of the effects of long-term {sup 240}Pu buildup in LMFBR cores. The uniform core version of ZPR-6/7 is evaluated in ZPR-LMFR-EXP-001. This document only addresses measurements in the high {sup 240}Pu core version of ZPR-6/7. Many types of measurements were performed as part of the ZPR-6/7 program. Measurements of criticality, sodium void worth, control rod worth and reaction rate distributions in the high {sup 240}Pu core configuration are evaluated here. For each category of measurements, the uncertainties are evaluated, and benchmark model data are provided.

  15. Modeling

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

    in warm dense matter experiments with diffuse interface methods in the ALE-AMR code Wangyi Liu ∗ , John Barnard, Alex Friedman, Nathan Masters, Aaron Fisher, Velemir Mlaker, Alice Koniges, David Eder † August 4, 2011 Abstract In this paper we describe an implementation of a single-fluid inter- face model in the ALE-AMR code to simulate surface tension effects. The model does not require explicit information on the physical state of the two phases. The only change to the existing fluid

  16. Drilling and coring methods that minimize the disturbance of...

    Office of Scientific and Technical Information (OSTI)

    Drilling and coring methods that minimize the disturbance of cuttings, core, and rock formation in the unsaturated zone, Yucca Mountain, Nevada Hammermeister, D.P.; Blout, D.O.;...

  17. Mineral Deformation at Earth's Core-Mantle Boundary

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

    (except for its liquid-iron outer core), this convection causes deformation of solid rocks by plastic flow. At the core-mantle boundary (CMB), 2900 km deep, seismologists have...

  18. Armored spring-core superconducting cable and method of construction

    DOE Patents [OSTI]

    McIntyre, Peter M.; Soika, Rainer H.

    2002-01-01

    An armored spring-core superconducting cable (12) is provided. The armored spring-core superconducting cable (12) may include a spring-core (20), at least one superconducting strand (24) wound onto the spring-core (20), and an armored shell (22) that encases the superconducting strands (24). The spring-core (20) is generally a perforated tube that allows purge gases and cryogenic liquids to be circulated through the armored superconducting cable (12), as well as managing the internal stresses within the armored spring-core superconducting cable (12). The armored shell (22) manages the external stresses of the armored spring-core superconducting cable (12) to protect the fragile superconducting strands (24). The armored spring-core superconducting cable (12) may also include a conductive jacket (34) formed outwardly of the armored shell (22).

  19. Core Competency Worksheets for Significant Cybersecurity Roles | Department

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

    of Energy Core Competency Worksheets for Significant Cybersecurity Roles Core Competency Worksheets for Significant Cybersecurity Roles shutterstock_1703802_jpg.jpg The OCIO has developed core competency worksheets that describe the minimum core competencies for each functional cyber role as documented in the DOE Essential Body of Knowledge (EBK). These worksheets can be used by any agency or private entity to assist in developing site or organization-specific, role-based training for cyber

  20. Hanford People Core (HCP) PIA, Richland Operations Office | Department of

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

    Energy People Core (HCP) PIA, Richland Operations Office Hanford People Core (HCP) PIA, Richland Operations Office Hanford People Core (HCP) PIA, Richland Operations Office PDF icon Hanford People Core (HCP) PIA, Richland Operations Office More Documents & Publications E-IDR (Inventory Disclosure Record) PIA, Idaho National Laboratory Occupational Medicine - Assistant PIA, Idaho National Laboratory Integrated Safety Management Workshop Registration, PIA, Idaho National Laboratory

  1. Core Analysis At Raft River Geothermal Area (1981) | Open Energy...

    Open Energy Info (EERE)

    search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Core Analysis At Raft River Geothermal Area (1981) Exploration Activity Details Location Raft River...

  2. Core Analysis At Raft River Geothermal Area (1976) | Open Energy...

    Open Energy Info (EERE)

    search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Core Analysis At Raft River Geothermal Area (1976) Exploration Activity Details Location Raft River...

  3. Core Analysis At Jemez Mountain Area (Eichelberger & Koch, 1979...

    Open Energy Info (EERE)

    Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Core Analysis At Jemez Mountain Area (Eichelberger & Koch, 1979) Exploration Activity...

  4. Mineral Deformation at Earth's Core-Mantle Boundary

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

    Mineral Deformation at Earth's Core-Mantle Boundary Mineral Deformation at Earth's Core-Mantle Boundary Print Wednesday, 31 August 2011 00:00 Earth is a dynamic planet in which convection takes place on the scale of thousands of kilometers. Because Earth is mostly solid (except for its liquid-iron outer core), this convection causes deformation of solid rocks by plastic flow. At the core-mantle boundary (CMB), 2900 km deep, seismologists have discovered that seismic waves travel faster in

  5. Probing Core-Hole Localization in Molecular Nitrogen

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

    Probing Core-Hole Localization in Molecular Nitrogen Probing Core-Hole Localization in Molecular Nitrogen Print Wednesday, 25 February 2009 00:00 The behavior of the core hole created in molecular x-ray photoemission experiments has provided molecular scientists with a valuable window through which to probe the electronic structure and dynamics of molecules. But the answer to one fundamental quantum question-whether the core hole is localized or delocalized-has remained elusive for diatomic

  6. The SNL100-02 blade : advanced core material design studies for the Sandia 100-meter blade.

    SciTech Connect (OSTI)

    Griffith, Daniel

    2013-11-01

    A series of design studies are performed to investigate the effects of advanced core materials and a new core material strategy on blade weight and performance for large blades using the Sandia 100-meter blade designs as a starting point. The initial core material design studies were based on the SNL100-01 100- meter carbon spar design. Advanced core material with improved performance to weight was investigated with the goal to reduce core material content in the design and reduce blade weight. A secondary element of the core study was to evaluate the suitability of core materials from natural, regrowable sources such as balsa and recyclable foam materials. The new core strategy for the SNL100-02 design resulted in a design mass of 59 tons, which is a 20% reduction from the most recent SNL100-01 carbon spar design and over 48% reduction from the initial SNL100-00 all-glass baseline blade. This document provides a description of the final SNL100-02 design, includes a description of the major design modifications, and summarizes the pertinent blade design information. This document is also intended to be a companion document to the distribution of the NuMAD blade model files for SNL100-02 that are made publicly available.

  7. Designing a New Fuel for HFIR-Performance Parameters for LEU Core Configurations

    SciTech Connect (OSTI)

    Ilas, Germina [ORNL; Primm, Trent [ORNL; Gehin, Jess C [ORNL

    2009-01-01

    An engineering design study for a fuel that would enable the conversion of the High Flux Isotope Reactor from highly enriched uranium to low enriched uranium fuel is ongoing as part of an effort sponsored by the U.S. Department of Energy's National Nuclear Security Administration through the Global Threat Reduction Initiative. Given the unique fuel and core design and high power density of the reactor and the requirement that the impact of the fuel change on the core performance and operation be minimal, this conversion study presents a complex and challenging task, requiring improvements in the computational models currently used to support the operation of the reactor and development of new models that would take advantage of newly available simulation methods and tools. The computational models used to search for a fuel design that would meet the requirements for the conversion study and the results obtained with these models are presented and discussed. Estimates of relevant reactor performance parameters for the low enriched uranium fuel core are presented and compared to the corresponding data for the currently operating highly enriched uranium fuel core.

  8. Video: Federal Energy Management Program eTraining Core Courses |

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

    Department of Energy Federal Energy Management Program eTraining Core Courses Video: Federal Energy Management Program eTraining Core Courses Video summarizes the Federal Energy Management Program's eTraining core courses available anytime online on the Whole Building Design Guide website

  9. Core-in-shell sorbent for hot coal gas desulfurization

    DOE Patents [OSTI]

    Wheelock, Thomas D.; Akiti, Jr., Tetteh T.

    2004-02-10

    A core-in-shell sorbent is described herein. The core is reactive to the compounds of interest, and is preferably calcium-based, such as limestone for hot gas desulfurization. The shell is a porous protective layer, preferably inert, which allows the reactive core to remove the desired compounds while maintaining the desired physical characteristics to withstand the conditions of use.

  10. Modeling

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

    Sandia Co-Hosts "Climate Risk Forum: Bridging Climate Science and Actuarial Practice" This Fall event was a follow-up to a Climate and Environment Program Area meeting with the California governor's office in July. There, the California Insurance Commissioner, Dave Jones, recognized the value of Sandia's climate-impact modeling and analysis work, led by Stephen Conrad (manager of Sandia's Resilience and Regulatory Effects Dept.), and wanted to connect that [...] By

  11. Collapse and fragmentation of magnetic molecular cloud cores with the Enzo AMR MHD code. II. Prolate and oblate cores

    SciTech Connect (OSTI)

    Boss, Alan P.; Keiser, Sandra A.

    2014-10-10

    We present the results of a large suite of three-dimensional models of the collapse of magnetic molecular cloud cores using the adaptive mesh refinement code Enzo2.2 in the ideal magnetohydrodynamics approximation. The cloud cores are initially either prolate or oblate, centrally condensed clouds with masses of 1.73 or 2.73 M {sub ?}, respectively. The radial density profiles are Gaussian, with central densities 20 times higher than boundary densities. A barotropic equation of state is used to represent the transition from low density isothermal phases, to high density optically thick phases. The initial magnetic field strength ranges from 6.3 to 100 ?G, corresponding to clouds that are strongly to marginally supercritical, respectively, in terms of the mass to magnetic flux ratio. The magnetic field is initially uniform and aligned with the clouds' rotation axes, with initial ratios of rotational to gravitational energy ranging from 10{sup 4} to 0.1. Two significantly different outcomes for collapse result: (1) formation of single protostars with spiral arms, and (2) fragmentation into multiple protostar systems. The transition between these two outcomes depends primarily on the initial magnetic field strength, with fragmentation occurring for mass to flux ratios greater than about 14 times the critical ratio for prolate clouds. Oblate clouds typically fragment into several times more clumps than prolate clouds. Multiple, rather than binary, system formation is the general rule in either case, suggesting that binary stars are primarily the result of the orbital dissolution of multiple protostar systems.

  12. Hunton Group core workshop and field trip

    SciTech Connect (OSTI)

    Johnson, K.S.

    1993-12-31

    The Late Ordovician-Silurian-Devonian Hunton Group is a moderately thick sequence of shallow-marine carbonates deposited on the south edge of the North American craton. This rock unit is a major target for petroleum exploration and reservoir development in the southern Midcontinent. The workshop described here was held to display cores, outcrop samples, and other reservoir-characterization studies of the Hunton Group and equivalent strata throughout the region. A field trip was organized to complement the workshop by allowing examination of excellent outcrops of the Hunton Group of the Arbuckle Mountains.

  13. Validation Results for Core-Scale Oil Shale Pyrolysis

    SciTech Connect (OSTI)

    Staten, Josh; Tiwari, Pankaj

    2015-03-01

    This report summarizes a study of oil shale pyrolysis at various scales and the subsequent development a model for in situ production of oil from oil shale. Oil shale from the Mahogany zone of the Green River formation was used in all experiments. Pyrolysis experiments were conducted at four scales, powdered samples (100 mesh) and core samples of 0.75”, 1” and 2.5” diameters. The batch, semibatch and continuous flow pyrolysis experiments were designed to study the effect of temperature (300°C to 500°C), heating rate (1°C/min to 10°C/min), pressure (ambient and 500 psig) and size of the sample on product formation. Comprehensive analyses were performed on reactants and products - liquid, gas and spent shale. These experimental studies were designed to understand the relevant coupled phenomena (reaction kinetics, heat transfer, mass transfer, thermodynamics) at multiple scales. A model for oil shale pyrolysis was developed in the COMSOL multiphysics platform. A general kinetic model was integrated with important physical and chemical phenomena that occur during pyrolysis. The secondary reactions of coking and cracking in the product phase were addressed. The multiscale experimental data generated and the models developed provide an understanding of the simultaneous effects of chemical kinetics, and heat and mass transfer on oil quality and yield. The comprehensive data collected in this study will help advance the move to large-scale in situ oil production from the pyrolysis of oil shale.

  14. Three-dimensional thermoelastic analysis of a Fort St. Vrain core support block

    SciTech Connect (OSTI)

    Butler, T.A.; Anderson, C.A.

    1981-09-01

    A thermoelastic stress analysis of a graphite core support block in the Fort St. Vrain High-Temperature Gas-Cooled Reactor is described. The support block is subjected to thermal stresses caused by a loss of forced circulation accident of the reactor system. Two- and three-dimensional finite element models of the core support block are analyzed using the ADINAT and ADINA codes, and results are given that verify the integrity of this structural component under the given accident condition. 10 refs., 39 figs.

  15. Precursors to potential severe core damage accidents: 1992, A status report. Volume 17, Main report and Appendix A

    SciTech Connect (OSTI)

    Cox, D.F.; Cletcher, J.W.; Copinger, D.A.; Cross-Dial, A.E.; Morris, R.H.; Vanden Heuvel, L.N.; Dolan, B.W.; Jansen, J.M.; Minarick, J.W.; Lau, W.; Salyer, W.D.

    1993-12-01

    Twenty-seven operational events with conditional probabilities of subsequent severe core damage of 1.0 {times} 10E-06 or higher occurring at commercial light-water reactors during 1992 are considered to be precursors to potential core damage. These are described along with associated significance estimates, categorization, and subsequent analyses. The report discusses (1) the general rationale for this study, (2) the selection and documentation of events as precursors, (3) the estimation and use of conditional probabilities of subsequent severe core damage to rank precursor events, and (4) the plant models used in the analysis process.

  16. Nijmegen soft-core potential including two-meson exchange

    SciTech Connect (OSTI)

    Stoks, V.G.J.; Rijken, T.A.

    1995-05-10

    We report on the progress of the construction of the extended soft-core (ESC) Nijmegen potential. Next to the standard one-boson-exchange parts, the model includes the pion-meson-exchange potentials due to the parallel and crossed-box diagrams, as well as the one-pair and two-pair diagrams, vertices for which can be identified with similar interactions appearing in chiral-symmetric Lagrangians. Although the ESC potential is still under construction, it already gives an excellent description of all {ital NN} scattering data below 350 MeV with {chi}{sup 2}/datum=1.3. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  17. Modeling

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

    diffuse interface methods in ALE-AMR code with application in modeling NDCX-II experiments Wangyi Liu 1 , John Barnard 2 , Alex Friedman 2 , Nathan Masters 2 , Aaron Fisher 2 , Alice Koniges 2 , David Eder 2 1 LBNL, USA, 2 LLNL, USA This work was part of the Petascale Initiative in Computational Science at NERSC, supported by the Director, Office of Science, Advanced Scientific Computing Research, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. This work was performed

  18. Modeling

    SciTech Connect (OSTI)

    Loth, E.; Tryggvason, G.; Tsuji, Y.; Elghobashi, S. E.; Crowe, Clayton T.; Berlemont, A.; Reeks, M.; Simonin, O.; Frank, Th; Onishi, Yasuo; Van Wachem, B.

    2005-09-01

    Slurry flows occur in many circumstances, including chemical manufacturing processes, pipeline transfer of coal, sand, and minerals; mud flows; and disposal of dredged materials. In this section we discuss slurry flow applications related to radioactive waste management. The Hanford tank waste solids and interstitial liquids will be mixed to form a slurry so it can be pumped out for retrieval and treatment. The waste is very complex chemically and physically. The ARIEL code is used to model the chemical interactions and fluid dynamics of the waste.

  19. Caldicellulosiruptor Core and Pangenomes Reveal Determinants for

    SciTech Connect (OSTI)

    Blumer-Schuette, Sara E.; Giannone, Richard J; Zurawski, Jeffrey V; Ozdemir, Inci; Ma, Qin; Yin, Yanbin; Xu, Ying; Kataeva, Irena; Poole, Farris; Adams, Michael W. W.; Hamilton-Brehm, Scott; Elkins, James G; Larimer, Frank W; Land, Miriam L; Hauser, Loren John; Cottingham, Robert W; Hettich, Robert {Bob} L; Kelly, Robert M

    2012-01-01

    Extremely thermophilic bacteria of the genus Caldicellulosiruptor utilize carbohydrate components of plant cell walls, including cellulose and hemicellulose, facilitated by a diverse set of glycoside hydrolases (GHs). From a biofuel perspective, this capability is crucial for deconstruction of plant biomass into fermentable sugars. While all species from the genus grow on xylan and acidpretreated switchgrass, growth on crystalline cellulose is variable. The basis for this variability was examined using microbiological, genomic, and proteomic analyses of eight globally diverse Caldicellulosiruptor species. The open Caldicellulosiruptor pangenome (4,009 open reading frames [ORFs]) encodes 106 GHs, representing 43 GH families, but only 26 GHs from 17 families are included in the core (noncellulosic) genome (1,543 ORFs). Differentiating the strongly cellulolytic Caldicellulosiruptor species from the others is a specific genomic locus that encodes multidomain cellulases from GH families 9 and 48, which are associated with cellulose-binding modules. This locus also encodes a novel adhesin associated with type IV pili, which was identified in the exoproteome bound to crystalline cellulose. Taking into account the core genomes, pangenomes, and individual genomes, the ancestral Caldicellulosiruptor was likely cellulolytic and evolved, in some cases, into species that lost the ability to degrade crystalline cellulose while maintaining the capacity to hydrolyze amorphous cellulose and hemicellulose.

  20. Energetics of the formation of CuAg coreshell nanoparticles

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

    Chandross, Michael

    2014-10-06

    Our work presents molecular dynamics and Monte Carlo simulations aimed at developing an understanding of the formation of coreshell CuAg nanoparticles. The effects of surface and interfacial energies were considered and used to form a phenomenological model that calculates the energy gained upon the formation of a coreshell structure from two previously distinct, non-interacting nanoparticles. In most cases, the coreshell structure was found to be energetically favored. Specifically, the difference in energy as a function of the radii of the individual Cu and Ag particles was examined, with the assumption that a coreshell structure forms. In general, it was foundmorethat the energetic gain from forming such a structure increased with increasing size of the initial Ag particle. This result was interpreted as a result of the reduction in surface energy. Moreover, for two separate particles, both Cu and Ag contribute to the surface energy; however, for a coreshell structure, the only contribution to the surface energy is from the Ag shell and the Cu contribution is changed to a CuAg interfacial energy, which is always smaller.less

  1. ISOTROPIC HEATING OF GALAXY CLUSTER CORES VIA RAPIDLY REORIENTING ACTIVE GALACTIC NUCLEUS JETS

    SciTech Connect (OSTI)

    Babul, Arif; Sharma, Prateek; Reynolds, Christopher S.

    2013-05-01

    Active galactic nucleus (AGN) jets carry more than sufficient energy to stave off catastrophic cooling of the intracluster medium (ICM) in the cores of cool-core clusters. However, in order to prevent catastrophic cooling, the ICM must be heated in a near-isotropic fashion and narrow bipolar jets with P{sub jet} = 10{sup 44-45} erg s{sup -1}, typical of radio AGNs at cluster centers, are inefficient in heating the gas in the transverse direction to the jets. We argue that due to existent conditions in cluster cores, the supermassive black holes (SMBHs) will, in addition to accreting gas via radiatively inefficient flows, experience short stochastic episodes of enhanced accretion via thin disks. In general, the orientation of these accretion disks will be misaligned with the spin axis of the black holes (BHs) and the ensuing torques will cause the BH's spin axis (and therefore the jet axis) to slew and rapidly change direction. This model not only explains recent observations showing successive generations of jet-lobes-bubbles in individual cool-core clusters that are offset from each other in the angular direction with respect to the cluster center, but also shows that AGN jets can heat the cluster core nearly isotropically on the gas cooling timescale. Our model does require that the SMBHs at the centers of cool-core clusters be spinning relatively slowly. Torques from individual misaligned disks are ineffective at tilting rapidly spinning BHs by more than a few degrees. Additionally, since SMBHs that host thin accretion disks will manifest as quasars, we predict that roughly 1-2 rich clusters within z < 0.5 should have quasars at their centers.

  2. Investigation on the Core Bypass Flow in a Very High Temperature Reactor

    SciTech Connect (OSTI)

    Hassan, Yassin

    2013-10-22

    Uncertainties associated with the core bypass flow are some of the key issues that directly influence the coolant mass flow distribution and magnitude, and thus the operational core temperature profiles, in the very high-temperature reactor (VHTR). Designers will attempt to configure the core geometry so the core cooling flow rate magnitude and distribution conform to the design values. The objective of this project is to study the bypass flow both experimentally and computationally. Researchers will develop experimental data using state-of-the-art particle image velocimetry in a small test facility. The team will attempt to obtain full field temperature distribution using racks of thermocouples. The experimental data are intended to benchmark computational fluid dynamics (CFD) codes by providing detailed information. These experimental data are urgently needed for validation of the CFD codes. The following are the project tasks: • Construct a small-scale bench-top experiment to resemble the bypass flow between the graphite blocks, varying parameters to address their impact on bypass flow. Wall roughness of the graphite block walls, spacing between the blocks, and temperature of the blocks are some of the parameters to be tested. • Perform CFD to evaluate pre- and post-test calculations and turbulence models, including sensitivity studies to achieve high accuracy. • Develop the state-of-the art large eddy simulation (LES) using appropriate subgrid modeling. • Develop models to be used in systems thermal hydraulics codes to account and estimate the bypass flows. These computer programs include, among others, RELAP3D, MELCOR, GAMMA, and GAS-NET. Actual core bypass flow rate may vary considerably from the design value. Although the uncertainty of the bypass flow rate is not known, some sources have stated that the bypass flow rates in the Fort St. Vrain reactor were between 8 and 25 percent of the total reactor mass flow rate. If bypass flow rates are on the high side, the quantity of cooling flow through the core may be considerably less than the nominal design value, causing some regions of the core to operate at temperatures in excess of the design values. These effects are postulated to lead to localized hot regions in the core that must be considered when evaluating the VHTR operational and accident scenarios.

  3. Test report for core drilling ignitability testing

    SciTech Connect (OSTI)

    Witwer, K.S.

    1996-08-08

    Testing was carried out with the cooperation of Westinghouse Hanford Company and the United States Bureau of Mines at the Pittsburgh Research Center in Pennsylvania under the Memorandum of Agreement 14- 09-0050-3666. Several core drilling equipment items, specifically those which can come in contact with flammable gasses while drilling into some waste tanks, were tested under conditions similar to actual field sampling conditions. Rotary drilling against steel and rock as well as drop testing of several different pieces of equipment in a flammable gas environment were the specific items addressed. The test items completed either caused no ignition of the gas mixture, or, after having hardware changes or drilling parameters modified, produced no ignition in repeat testing.

  4. Geologic analysis of Devonian Shale cores

    SciTech Connect (OSTI)

    1982-02-01

    Cleveland Cliffs Iron Company was awarded a DOE contract in December 1977 for field retrieval and laboratory analysis of cores from the Devonian shales of the following eleven states: Michigan, Illinois, Indiana, Ohio, New York, Pennsylvania, West Virginia, Maryland, Kentucky, Tennessee and Virginia. The purpose of this project is to explore these areas to determine the amount of natural gas being produced from the Devonian shales. The physical properties testing of the rock specimens were performed under subcontract at Michigan Technological University (MTU). The study also included LANDSAT information, geochemical research, structural sedimentary and tectonic data. Following the introduction, and background of the project this report covers the following: field retrieval procedures; laboratory procedures; geologic analysis (by state); references and appendices. (ATT)

  5. Understanding core-valence-valence Auger lineshapes

    SciTech Connect (OSTI)

    Jennison, D.R.

    1981-01-01

    As a result of recent advances in understanding, core-valence-valence (CVV) Auger spectroscopy is now being used as a local valence probe of molecular, chemisorbed and solid state species. Analysis of Auger data has led to the discovery of localized multi-hole valence excitations in covalent systems, and there is evidence that these excitations may play a major role in the dissociation of large molecules and in stimulated desorption from semiconductor surfaces. Understanding of the basic physics behind the CVV decay is summarized. The relative importance and applicability of factors which influence the decay amplitudes (local charge density, initial state screening, valence nonorthogonality and configuration mixing) and the Auger energies (independent vs coupled final state holes) are stressed.

  6. Rotary Mode Core Sample System availability improvement

    SciTech Connect (OSTI)

    Jenkins, W.W.; Bennett, K.L.; Potter, J.D.; Cross, B.T.; Burkes, J.M.; Rogers, A.C.

    1995-02-28

    The Rotary Mode Core Sample System (RMCSS) is used to obtain stratified samples of the waste deposits in single-shell and double-shell waste tanks at the Hanford Site. The samples are used to characterize the waste in support of ongoing and future waste remediation efforts. Four sampling trucks have been developed to obtain these samples. Truck I was the first in operation and is currently being used to obtain samples where the push mode is appropriate (i.e., no rotation of drill). Truck 2 is similar to truck 1, except for added safety features, and is in operation to obtain samples using either a push mode or rotary drill mode. Trucks 3 and 4 are now being fabricated to be essentially identical to truck 2.

  7. TOUGH+ v1.5 Core Code

    SciTech Connect (OSTI)

    2015-08-27

    TOUGH+ v1.5 is a numerical code for the simulation of multi-phase, multi-component flow and transport of mass and heat through porous and fractured media, and represents the third update of the code since its first release [Moridis et al., 2008]. TOUGH+ is a successor to the TOUGH2 [Pruess et al., 1991; 2012] family of codes for multi-component, multiphase ?uid and heat ?ow developed at the Lawrence Berkeley National Laboratory. It is written in standard FORTRAN 95/2003, and can be run on any computational platform (workstations, PC, Macintosh). TOUGH+ v1.5 employs dynamic memory allocation, thus minimizing storage requirements. It has a completely modular structure, follows the tenets of Object-Oriented Programming (OOP), and involves the advanced features of FORTRAN 95/2003, i.e., modules, derived data types, the use of pointers, lists and trees, data encapsulation, defined operators and assignments, operator extension and overloading, use of generic procedures, and maximum use of the powerful intrinsic vector and matrix processing operations. TOUGH+ v1.5 is the core code for its family of applications, i.e., the part of the code that is common to all its applications. It provides a description of the underlying physics and thermodynamics of non-isothermal flow, of the mathematical and numerical approaches, as well as a detailed explanation of the general (common to all applications) input requirements, options, capabilities and output specifications. The core code cannot run by itself: it needs to be coupled with the code for the specific TOUGH+ application option that describes a particular type of problem. The additional input requirements specific to a particular TOUGH+ application options and related illustrative examples can be found in the corresponding User?s Manual.

  8. TOUGH+ v1.5 Core Code

    Energy Science and Technology Software Center (OSTI)

    2015-08-27

    TOUGH+ v1.5 is a numerical code for the simulation of multi-phase, multi-component flow and transport of mass and heat through porous and fractured media, and represents the third update of the code since its first release [Moridis et al., 2008]. TOUGH+ is a successor to the TOUGH2 [Pruess et al., 1991; 2012] family of codes for multi-component, multiphase fluid and heat flow developed at the Lawrence Berkeley National Laboratory. It is written in standard FORTRANmore » 95/2003, and can be run on any computational platform (workstations, PC, Macintosh). TOUGH+ v1.5 employs dynamic memory allocation, thus minimizing storage requirements. It has a completely modular structure, follows the tenets of Object-Oriented Programming (OOP), and involves the advanced features of FORTRAN 95/2003, i.e., modules, derived data types, the use of pointers, lists and trees, data encapsulation, defined operators and assignments, operator extension and overloading, use of generic procedures, and maximum use of the powerful intrinsic vector and matrix processing operations. TOUGH+ v1.5 is the core code for its family of applications, i.e., the part of the code that is common to all its applications. It provides a description of the underlying physics and thermodynamics of non-isothermal flow, of the mathematical and numerical approaches, as well as a detailed explanation of the general (common to all applications) input requirements, options, capabilities and output specifications. The core code cannot run by itself: it needs to be coupled with the code for the specific TOUGH+ application option that describes a particular type of problem. The additional input requirements specific to a particular TOUGH+ application options and related illustrative examples can be found in the corresponding User’s Manual.« less

  9. Mass-radius relations and core-envelope decompositions of super-Earths and sub-Neptunes

    SciTech Connect (OSTI)

    Howe, Alex R.; Burrows, Adam; Verne, Wesley E-mail: burrows@astro.princeton.edu

    2014-06-01

    Many exoplanets have been discovered with radii of 1-4 R {sub ?}, between that of Earth and Neptune. A number of these are known to have densities consistent with solid compositions, while others are 'sub-Neptunes' likely to have significant H{sub 2}-He envelopes. Future surveys will no doubt significantly expand these populations. In order to understand how the measured masses and radii of such planets can inform their structures and compositions, we construct models both for solid layered planets and for planets with solid cores and gaseous envelopes, exploring a range of core masses, H{sub 2}-He envelope masses, and associated envelope entropies. For planets in the super-Earth/sub-Neptune regime for which both radius and mass are measured, we estimate how each is partitioned into a solid core and gaseous envelope, associating a specific core mass and envelope mass with a given exoplanet. We perform this decomposition for both ''Earth-like'' rock-iron cores and pure ice cores, and find that the necessary gaseous envelope masses for this important sub-class of exoplanets must range very widely from zero to many Earth masses, even for a given core mass. This result bears importantly on exoplanet formation and envelope evaporation processes.

  10. Framework Application for Core Edge Transport Simulation (FACETS)

    SciTech Connect (OSTI)

    Dr. Allen D. Malony; Dr. Sameer S. Shende; Dr. Kevin A. Huck; Mr. Alan Morris, and Mr. Wyatt Spear

    2012-03-14

    The goal of the FACETS project (Framework Application for Core-Edge Transport Simulations) was to provide a multiphysics, parallel framework application (FACETS) that will enable whole-device modeling for the U.S. fusion program, to provide the modeling infrastructure needed for ITER, the next step fusion confinement device. Through use of modern computational methods, including component technology and object oriented design, FACETS is able to switch from one model to another for a given aspect of the physics in a flexible manner. This enables use of simplified models for rapid turnaround or high-fidelity models that can take advantage of the largest supercomputer hardware. FACETS does so in a heterogeneous parallel context, where different parts of the application execute in parallel by utilizing task farming, domain decomposition, and/or pipelining as needed and applicable. ParaTools, Inc. was tasked with supporting the performance analysis and tuning of the FACETS components and framework in order to achieve the parallel scaling goals of the project. The TAU Performance System® was used for instrumentation, measurement, archiving, and profile / tracing analysis. ParaTools, Inc. also assisted in FACETS performance engineering efforts. Through the use of the TAU Performance System, ParaTools provided instrumentation, measurement, analysis and archival support for the FACETS project. Performance optimization of key components has yielded significant performance speedups. TAU was integrated into the FACETS build for both the full coupled application and the UEDGE component. The performance database provided archival storage of the performance regression testing data generated by the project, and helped to track improvements in the software development.

  11. Benchmark Evaluation of the NRAD Reactor LEU Core Startup Measurements

    SciTech Connect (OSTI)

    J. D. Bess; T. L. Maddock; M. A. Marshall

    2011-09-01

    The Neutron Radiography (NRAD) reactor is a 250-kW TRIGA-(Training, Research, Isotope Production, General Atomics)-conversion-type reactor at the Idaho National Laboratory; it is primarily used for neutron radiography analysis of irradiated and unirradiated fuels and materials. The NRAD reactor was converted from HEU to LEU fuel with 60 fuel elements and brought critical on March 31, 2010. This configuration of the NRAD reactor has been evaluated as an acceptable benchmark experiment and is available in the 2011 editions of the International Handbook of Evaluated Criticality Safety Benchmark Experiments (ICSBEP Handbook) and the International Handbook of Evaluated Reactor Physics Benchmark Experiments (IRPhEP Handbook). Significant effort went into precisely characterizing all aspects of the reactor core dimensions and material properties; detailed analyses of reactor parameters minimized experimental uncertainties. The largest contributors to the total benchmark uncertainty were the 234U, 236U, Er, and Hf content in the fuel; the manganese content in the stainless steel cladding; and the unknown level of water saturation in the graphite reflector blocks. A simplified benchmark model of the NRAD reactor was prepared with a keff of 1.0012 {+-} 0.0029 (1s). Monte Carlo calculations with MCNP5 and KENO-VI and various neutron cross section libraries were performed and compared with the benchmark eigenvalue for the 60-fuel-element core configuration; all calculated eigenvalues are between 0.3 and 0.8% greater than the benchmark value. Benchmark evaluations of the NRAD reactor are beneficial in understanding biases and uncertainties affecting criticality safety analyses of storage, handling, or transportation applications with LEU-Er-Zr-H fuel.

  12. Thermally Stable Nanocatalyst for High Temperature Reactions: Pt-Mesoporous Silica Core-Shell Nanoparticles

    SciTech Connect (OSTI)

    Joo, Sang Hoon; Park, J.Y.; Tsung, C.-K.; Yamada, Y.; Yang, P.; Somorjai, G.A.

    2008-10-25

    Recent advances in colloidal synthesis enabled the precise control of size, shape and composition of catalytic metal nanoparticles, allowing their use as model catalysts for systematic investigations of the atomic-scale properties affecting catalytic activity and selectivity. The organic capping agents stabilizing colloidal nanoparticles, however, often limit their application in high-temperature catalytic reactions. Here we report the design of a high-temperature stable model catalytic system that consists of Pt metal core coated with a mesoporous silica shell (Pt{at}mSiO{sub 2}). While inorganic silica shells encaged the Pt cores up to 750 C in air, the mesopores directly accessible to Pt cores made the Pt{at}mSiO{sub 2} nanoparticles as catalytically active as bare Pt metal for ethylene hydrogenation and CO oxidation. The high thermal stability of Pt{at}mSiO{sub 2} nanoparticles permitted high-temperature CO oxidation studies, including ignition behavior, which was not possible for bare Pt nanoparticles because of their deformation or aggregation. The results suggest that the Pt{at}mSiO{sub 2} nanoparticles are excellent nanocatalytic systems for high-temperature catalytic reactions or surface chemical processes, and the design concept employed in the Pt{at}mSiO{sub 2} core-shell catalyst can be extended to other metal-metal oxide compositions.

  13. A Two-Step Approach to Uncertainty Quantification of Core Simulators

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

    Yankov, Artem; Collins, Benjamin; Klein, Markus; Jessee, Matthew A.; Zwermann, Winfried; Velkov, Kiril; Pautz, Andreas; Downar, Thomas

    2012-01-01

    For the multiple sources of error introduced into the standard computational regime for simulating reactor cores, rigorous uncertainty analysis methods are available primarily to quantify the effects of cross section uncertainties. Two methods for propagating cross section uncertainties through core simulators are the XSUSA statistical approach and the “two-step” method. The XSUSA approach, which is based on the SUSA code package, is fundamentally a stochastic sampling method. Alternatively, the two-step method utilizes generalized perturbation theory in the first step and stochastic sampling in the second step. The consistency of these two methods in quantifying uncertainties in the multiplication factor andmore » in the core power distribution was examined in the framework of phase I-3 of the OECD Uncertainty Analysis in Modeling benchmark. With the Three Mile Island Unit 1 core as a base model for analysis, the XSUSA and two-step methods were applied with certain limitations, and the results were compared to those produced by other stochastic sampling-based codes. Based on the uncertainty analysis results, conclusions were drawn as to the method that is currently more viable for computing uncertainties in burnup and transient calculations.« less

  14. Turbine component casting core with high resolution region

    DOE Patents [OSTI]

    Kamel, Ahmed; Merrill, Gary B.

    2014-08-26

    A hollow turbine engine component with complex internal features can include a first region and a second, high resolution region. The first region can be defined by a first ceramic core piece formed by any conventional process, such as by injection molding or transfer molding. The second region can be defined by a second ceramic core piece formed separately by a method effective to produce high resolution features, such as tomo lithographic molding. The first core piece and the second core piece can be joined by interlocking engagement that once subjected to an intermediate thermal heat treatment process thermally deform to form a three dimensional interlocking joint between the first and second core pieces by allowing thermal creep to irreversibly interlock the first and second core pieces together such that the joint becomes physically locked together providing joint stability through thermal processing.

  15. Mineral Deformation at Earth's Core-Mantle Boundary

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

    Mineral Deformation at Earth's Core-Mantle Boundary Print Earth is a dynamic planet in which convection takes place on the scale of thousands of kilometers. Because Earth is mostly solid (except for its liquid-iron outer core), this convection causes deformation of solid rocks by plastic flow. At the core-mantle boundary (CMB), 2900 km deep, seismologists have discovered that seismic waves travel faster in certain directions. This seismic anisotropy appears to be related to the deformation of

  16. Mineral Deformation at Earth's Core-Mantle Boundary

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

    Mineral Deformation at Earth's Core-Mantle Boundary Print Earth is a dynamic planet in which convection takes place on the scale of thousands of kilometers. Because Earth is mostly solid (except for its liquid-iron outer core), this convection causes deformation of solid rocks by plastic flow. At the core-mantle boundary (CMB), 2900 km deep, seismologists have discovered that seismic waves travel faster in certain directions. This seismic anisotropy appears to be related to the deformation of

  17. Mineral Deformation at Earth's Core-Mantle Boundary

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

    Mineral Deformation at Earth's Core-Mantle Boundary Print Earth is a dynamic planet in which convection takes place on the scale of thousands of kilometers. Because Earth is mostly solid (except for its liquid-iron outer core), this convection causes deformation of solid rocks by plastic flow. At the core-mantle boundary (CMB), 2900 km deep, seismologists have discovered that seismic waves travel faster in certain directions. This seismic anisotropy appears to be related to the deformation of

  18. Graded core/shell semiconductor nanorods and nanorod barcodes

    DOE Patents [OSTI]

    Alivisatos, A. Paul; Scher, Erik C.; Manna, Liberato

    2009-05-19

    Disclosed herein is a graded core/shell semiconductor nanorod having at least a first segment of a core of a Group II-VI, Group III-V or a Group IV semiconductor, a graded shell overlying the core, wherein the graded shell comprises at least two monolayers, wherein the at least two monolayers each independently comprise a Group II-VI, Group III-V or a Group IV semiconductor.

  19. Next Generation Sequencing at the University of Chicago Genomics Core

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Next Generation Sequencing at the University of Chicago Genomics Core Citation Details In-Document Search Title: Next Generation Sequencing at the University of Chicago Genomics Core The University of Chicago Genomics Core provides University of Chicago investigators (and external clients) access to State-of-the-Art genomics capabilities: next generation sequencing, Sanger sequencing / genotyping and micro-arrays (gene expression, genotyping, and methylation).

  20. Mineral Deformation at Earth's Core-Mantle Boundary

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

    Mineral Deformation at Earth's Core-Mantle Boundary Print Earth is a dynamic planet in which convection takes place on the scale of thousands of kilometers. Because Earth is mostly solid (except for its liquid-iron outer core), this convection causes deformation of solid rocks by plastic flow. At the core-mantle boundary (CMB), 2900 km deep, seismologists have discovered that seismic waves travel faster in certain directions. This seismic anisotropy appears to be related to the deformation of

  1. Mineral Deformation at Earth's Core-Mantle Boundary

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

    Mineral Deformation at Earth's Core-Mantle Boundary Print Earth is a dynamic planet in which convection takes place on the scale of thousands of kilometers. Because Earth is mostly solid (except for its liquid-iron outer core), this convection causes deformation of solid rocks by plastic flow. At the core-mantle boundary (CMB), 2900 km deep, seismologists have discovered that seismic waves travel faster in certain directions. This seismic anisotropy appears to be related to the deformation of

  2. Mineral Deformation at Earth's Core-Mantle Boundary

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

    Mineral Deformation at Earth's Core-Mantle Boundary Print Earth is a dynamic planet in which convection takes place on the scale of thousands of kilometers. Because Earth is mostly solid (except for its liquid-iron outer core), this convection causes deformation of solid rocks by plastic flow. At the core-mantle boundary (CMB), 2900 km deep, seismologists have discovered that seismic waves travel faster in certain directions. This seismic anisotropy appears to be related to the deformation of

  3. Mineral Deformation at Earth's Core-Mantle Boundary

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

    Mineral Deformation at Earth's Core-Mantle Boundary Print Earth is a dynamic planet in which convection takes place on the scale of thousands of kilometers. Because Earth is mostly solid (except for its liquid-iron outer core), this convection causes deformation of solid rocks by plastic flow. At the core-mantle boundary (CMB), 2900 km deep, seismologists have discovered that seismic waves travel faster in certain directions. This seismic anisotropy appears to be related to the deformation of

  4. Mineral Deformation at Earth's Core-Mantle Boundary

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

    Mineral Deformation at Earth's Core-Mantle Boundary Print Earth is a dynamic planet in which convection takes place on the scale of thousands of kilometers. Because Earth is mostly solid (except for its liquid-iron outer core), this convection causes deformation of solid rocks by plastic flow. At the core-mantle boundary (CMB), 2900 km deep, seismologists have discovered that seismic waves travel faster in certain directions. This seismic anisotropy appears to be related to the deformation of

  5. SECURITY CORE FUNCTION AND DEFINITION REPORT | Department of Energy

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

    SECURITY CORE FUNCTION AND DEFINITION REPORT SECURITY CORE FUNCTION AND DEFINITION REPORT The first phase of the Lemnos Interoperable Security Program shall lay the foundation for future work by providing a guiding example of the vocabulary, metrics, interoperability requirements and interoperability assurance methodologies used to create interoperable network security products. From a requirements definition perspective, this translates to: PDF icon SECURITY CORE FUNCTION AND DEFINITION REPORT

  6. Probing Core-Hole Localization in Molecular Nitrogen

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

    Probing Core-Hole Localization in Molecular Nitrogen Print The behavior of the core hole created in molecular x-ray photoemission experiments has provided molecular scientists with a valuable window through which to probe the electronic structure and dynamics of molecules. But the answer to one fundamental quantum question-whether the core hole is localized or delocalized-has remained elusive for diatomic molecules in which both atoms are the same element. An international team of scientists

  7. Magnetic Vortex Core Reversal by Low-Field Excitations

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

    Magnetic Vortex Core Reversal by Low-Field Excitations Print In micrometer-sized magnetic thin films, the magnetization typically adopts an in-plane, circular configuration known as a magnetic vortex. At the vortex core, the magnetization turns sharply out of the plane, pointing either up or down. Magnetic data storage based on this binary phenomenon is an intriguing concept, but it would require the ability to flip the vortex cores on demand. Because these structures are highly stable, very

  8. Magnetic Vortex Core Reversal by Low-Field Excitations

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

    Magnetic Vortex Core Reversal by Low-Field Excitations Print In micrometer-sized magnetic thin films, the magnetization typically adopts an in-plane, circular configuration known as a magnetic vortex. At the vortex core, the magnetization turns sharply out of the plane, pointing either up or down. Magnetic data storage based on this binary phenomenon is an intriguing concept, but it would require the ability to flip the vortex cores on demand. Because these structures are highly stable, very

  9. Magnetic Vortex Core Reversal by Low-Field Excitations

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

    Magnetic Vortex Core Reversal by Low-Field Excitations Print In micrometer-sized magnetic thin films, the magnetization typically adopts an in-plane, circular configuration known as a magnetic vortex. At the vortex core, the magnetization turns sharply out of the plane, pointing either up or down. Magnetic data storage based on this binary phenomenon is an intriguing concept, but it would require the ability to flip the vortex cores on demand. Because these structures are highly stable, very

  10. Magnetic Vortex Core Reversal by Low-Field Excitations

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

    Magnetic Vortex Core Reversal by Low-Field Excitations Print In micrometer-sized magnetic thin films, the magnetization typically adopts an in-plane, circular configuration known as a magnetic vortex. At the vortex core, the magnetization turns sharply out of the plane, pointing either up or down. Magnetic data storage based on this binary phenomenon is an intriguing concept, but it would require the ability to flip the vortex cores on demand. Because these structures are highly stable, very

  11. Magnetic Vortex Core Reversal by Low-Field Excitations

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

    Magnetic Vortex Core Reversal by Low-Field Excitations Print In micrometer-sized magnetic thin films, the magnetization typically adopts an in-plane, circular configuration known as a magnetic vortex. At the vortex core, the magnetization turns sharply out of the plane, pointing either up or down. Magnetic data storage based on this binary phenomenon is an intriguing concept, but it would require the ability to flip the vortex cores on demand. Because these structures are highly stable, very

  12. Magnetic Vortex Core Reversal by Low-Field Excitations

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

    Magnetic Vortex Core Reversal by Low-Field Excitations Print In micrometer-sized magnetic thin films, the magnetization typically adopts an in-plane, circular configuration known as a magnetic vortex. At the vortex core, the magnetization turns sharply out of the plane, pointing either up or down. Magnetic data storage based on this binary phenomenon is an intriguing concept, but it would require the ability to flip the vortex cores on demand. Because these structures are highly stable, very

  13. Magnetic Vortex Core Reversal by Low-Field Excitations

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

    Magnetic Vortex Core Reversal by Low-Field Excitations Print In micrometer-sized magnetic thin films, the magnetization typically adopts an in-plane, circular configuration known as a magnetic vortex. At the vortex core, the magnetization turns sharply out of the plane, pointing either up or down. Magnetic data storage based on this binary phenomenon is an intriguing concept, but it would require the ability to flip the vortex cores on demand. Because these structures are highly stable, very

  14. Probing Core-Hole Localization in Molecular Nitrogen

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

    Probing Core-Hole Localization in Molecular Nitrogen Print The behavior of the core hole created in molecular x-ray photoemission experiments has provided molecular scientists with a valuable window through which to probe the electronic structure and dynamics of molecules. But the answer to one fundamental quantum question-whether the core hole is localized or delocalized-has remained elusive for diatomic molecules in which both atoms are the same element. An international team of scientists

  15. Probing Core-Hole Localization in Molecular Nitrogen

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

    Probing Core-Hole Localization in Molecular Nitrogen Print The behavior of the core hole created in molecular x-ray photoemission experiments has provided molecular scientists with a valuable window through which to probe the electronic structure and dynamics of molecules. But the answer to one fundamental quantum question-whether the core hole is localized or delocalized-has remained elusive for diatomic molecules in which both atoms are the same element. An international team of scientists

  16. Probing Core-Hole Localization in Molecular Nitrogen

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

    Probing Core-Hole Localization in Molecular Nitrogen Print The behavior of the core hole created in molecular x-ray photoemission experiments has provided molecular scientists with a valuable window through which to probe the electronic structure and dynamics of molecules. But the answer to one fundamental quantum question-whether the core hole is localized or delocalized-has remained elusive for diatomic molecules in which both atoms are the same element. An international team of scientists

  17. Graded core/shell semiconductor nanorods and nanorod barcodes

    DOE Patents [OSTI]

    Alivisatos, A. Paul; Scher, Erik C.; Manna, Liberato

    2010-12-14

    Graded core/shell semiconductor nanorods and shaped nanorods are disclosed comprising Group II-VI, Group III-V and Group IV semiconductors and methods of making the same. Also disclosed are nanorod barcodes using core/shell nanorods where the core is a semiconductor or metal material, and with or without a shell. Methods of labeling analytes using the nanorod barcodes are also disclosed.

  18. Graded core/shell semiconductor nanorods and nanorod barcodes

    DOE Patents [OSTI]

    Alivisatos, A. Paul; Scher, Erik C.; Manna, Liberato

    2013-03-26

    Graded core/shell semiconductor nanorods and shapped nanorods are disclosed comprising Group II-VI, Group III-V and Group IV semiconductors and methods of making the same. Also disclosed are nanorod barcodes using core/shell nanorods where the core is a semiconductor or metal material, and with or without a shell. Methods of labeling analytes using the nanorod barcodes are also disclosed.

  19. Ultrafast Core-Hole Induced Dynamics in Water

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

    Ultrafast Core-Hole Induced Dynamics in Water Ultrafast Core-Hole Induced Dynamics in Water Print Wednesday, 22 February 2006 00:00 A thorough understanding of the chemical processes that are initiated when radiation interacts with aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a water molecule sets off motions that can affect bonding configurations, which in

  20. VERA Core Simulator Methodology for PWR Cycle Depletion (Conference) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect VERA Core Simulator Methodology for PWR Cycle Depletion Citation Details In-Document Search Title: VERA Core Simulator Methodology for PWR Cycle Depletion Authors: Kochunas, Brendan [1] ; Collins, Benjamin S [2] ; Jabaay, Daniel [1] ; Kim, Kang Seog [2] ; Graham, Aaron [1] ; Stimpson, Shane [1] ; Wieselquist, William A [2] ; Clarno, Kevin T [2] ; Palmtag, Scott [3] ; Downar, Thomas [1] ; Gehin, Jess C [2] + Show Author Affiliations University of Michigan ORNL Core Physics,

  1. Triggering collapse of the presolar dense cloud core and injecting short-lived radioisotopes with a shock wave. III. Rotating three-dimensional cloud cores

    SciTech Connect (OSTI)

    Boss, Alan P.; Keiser, Sandra A.

    2014-06-10

    A key test of the supernova triggering and injection hypothesis for the origin of the solar system's short-lived radioisotopes is to reproduce the inferred initial abundances of these isotopes. We present here the most detailed models to date of the shock wave triggering and injection process, where shock waves with varied properties strike fully three-dimensional, rotating, dense cloud cores. The models are calculated with the FLASH adaptive mesh hydrodynamics code. Three different outcomes can result: triggered collapse leading to fragmentation into a multiple protostar system; triggered collapse leading to a single protostar embedded in a protostellar disk; or failure to undergo dynamic collapse. Shock wave material is injected into the collapsing clouds through Rayleigh-Taylor fingers, resulting in initially inhomogeneous distributions in the protostars and protostellar disks. Cloud rotation about an axis aligned with the shock propagation direction does not increase the injection efficiency appreciably, as the shock parameters were chosen to be optimal for injection even in the absence of rotation. For a shock wave from a core-collapse supernova, the dilution factors for supernova material are in the range of ?10{sup 4} to ?3 10{sup 4}, in agreement with recent laboratory estimates of the required amount of dilution for {sup 60}Fe and {sup 26}Al. We conclude that a type II supernova remains as a promising candidate for synthesizing the solar system's short-lived radioisotopes shortly before their injection into the presolar cloud core by the supernova's remnant shock wave.

  2. Checkerboard seed-blanket thorium fuel core concepts for heavy...

    Office of Scientific and Technical Information (OSTI)

    concepts for heavy water moderated reactors Citation Details In-Document Search Title: Checkerboard seed-blanket thorium fuel core concepts for heavy water moderated reactors ...

  3. Livermore Field Office sets core values as part of continuous...

    National Nuclear Security Administration (NNSA)

    At their recent off-site continuous improvement session, the NNSA Livermore Field Office (LFO) in California unveiled their new set of core values: Integrity - Trustworthy, ...

  4. Core Analysis At Geysers Area (Boitnott, 2003) | Open Energy...

    Open Energy Info (EERE)

    Exploration Activity Details Location Geysers Area Exploration Technique Core Analysis Activity Date Usefulness not indicated DOE-funding Unknown References Greg N. Boitnott...

  5. Core Analysis At International Geothermal Area, Indonesia (Boitnott...

    Open Energy Info (EERE)

    Location International Geothermal Area Indonesia Exploration Technique Core Analysis Activity Date Usefulness not indicated DOE-funding Unknown References Greg N. Boitnott...

  6. Ultrafast Core-Hole Induced Dynamics in Water

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

    aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core...

  7. Core Holes At Steamboat Springs Area (Warpinski, Et Al., 2004...

    Open Energy Info (EERE)

    2004) Exploration Activity Details Location Steamboat Springs Area Exploration Technique Core Holes Activity Date Usefulness not indicated DOE-funding Unknown Notes Update to...

  8. Core Holes At Long Valley Caldera Geothermal Area (Benoit, 1984...

    Open Energy Info (EERE)

    Exploration Basis Several core holes were also drilled in the caldera's west moat by Phillips Petroleum Company in 1982, including: PLV-1, drilled to approximately 711 m depth...

  9. Core Analysis At Coso Geothermal Area (1979) | Open Energy Information

    Open Energy Info (EERE)

    useful DOE-funding Unknown Exploration Basis Compare microcracks between Coso and Raft River geothermal areas Notes Microcracks were observed in core samples from Coso. Both...

  10. Core Analysis At Raft River Geothermal Area (1979) | Open Energy...

    Open Energy Info (EERE)

    Raft River Geothermal Area (1979) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Core Analysis At Raft River Geothermal Area (1979) Exploration...

  11. Core Analysis At Raft River Geothermal Area (2011) | Open Energy...

    Open Energy Info (EERE)

    that were conducted on the core sample are presented. References Jones, C.; Moore, J.; Teplow, W.; Craig, S. (1 January 2011) GEOLOGY AND HYDROTHERMAL ALTERATION OF THE...

  12. Core Holes At Long Valley Caldera Geothermal Area (Urban, Et...

    Open Energy Info (EERE)

    Technique Core Holes Activity Date 1986 - 1986 Usefulness useful DOE-funding Unknown Exploration Basis After several temperature-gradient holes were drilled in 1982 to the...

  13. Core Analysis At Geysers Area (Lambert & Epstein, 1992) | Open...

    Open Energy Info (EERE)

    (Lambert & Epstein, 1992) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Core Analysis At Geysers Area (Lambert & Epstein, 1992) Exploration...

  14. Core Analysis At Coso Geothermal Area (1980) | Open Energy Information

    Open Energy Info (EERE)

    Exploration Activity Details Location Coso Geothermal Area Exploration Technique Core Analysis Activity Date 1980 Usefulness not indicated DOE-funding Unknown Exploration Basis...

  15. Core Analysis At Newberry Caldera Area (Carothers, Et Al., 1987...

    Open Energy Info (EERE)

    Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Core Analysis At Newberry Caldera Area (Carothers, Et Al., 1987) Exploration Activity...

  16. MHK Projects/Cornwall Ontario River Energy CORE | Open Energy...

    Open Energy Info (EERE)

    Cornwall Ontario River Energy CORE < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3",...

  17. DOE Issues Final RFP for Idaho Cleanup Project Core

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

    Environmental Management Consolidated Business Center 250 E. 5th Street, Suite 500, ... DOE Issues Final RFP for Idaho Cleanup Project Core Cincinnati - The U.S. Department of ...

  18. Mineral Deformation at Earth's Core-Mantle Boundary

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

    core-mantle boundary (CMB), 2900 km deep, seismologists have discovered that seismic waves travel faster in certain directions. This seismic anisotropy appears to be related to...

  19. Core Holes At Valles Caldera - Sulphur Springs Geothermal Area...

    Open Energy Info (EERE)

    Goff, Et Al., 1987) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Core Holes At Valles Caldera - Sulphur Springs Geothermal Area (Goff, Et Al.,...

  20. Core Analysis At Flint Geothermal Area (DOE GTP) | Open Energy...

    Open Energy Info (EERE)

    Flint Geothermal Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Core Analysis At Flint Geothermal Area (DOE GTP) Exploration...

  1. Core Analysis At Colrado Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    Colrado Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Core Analysis At Colrado Area (DOE GTP) Exploration Activity Details...

  2. Core Analysis At Mcgee Mountain Area (DOE GTP) | Open Energy...

    Open Energy Info (EERE)

    Mcgee Mountain Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Core Analysis At Mcgee Mountain Area (DOE GTP) Exploration Activity...

  3. Accelerator-driven subcritical fission in molten salt core: Closing...

    Office of Scientific and Technical Information (OSTI)

    Accelerator-driven subcritical fission in molten salt core: Closing the nuclear fuel cycle for green nuclear energy Citation Details In-Document Search Title: Accelerator-driven ...

  4. Core Analysis At Desert Peak Area (Laney, 2005) | Open Energy...

    Open Energy Info (EERE)

    Desert Peak Area (Laney, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Core Analysis At Desert Peak Area (Laney, 2005) Exploration...

  5. Magnetic Vortex Core Reversal by Low-Field Excitations

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

    Although their practical realization is still far off, data storage systems based on this core-switching scheme could have several advantages, including high thermal stability,...

  6. Core excitation effects in the breakup of halo nuclei

    SciTech Connect (OSTI)

    Moro, A. M.; Diego, R. de; Lay, J. A.; Crespo, R.; Johnson, R. C.; Arias, J. M.; Gomez-Camacho, J.

    2012-10-20

    The role of core excitation in the structure and dynamics of two-body halo nuclei is investigated. We present calculations for the resonant breakup of {sup 11}Be on protons at an incident energy of 63.7 MeV/nucleon, where core excitation effects were shown to be important. To describe the reaction, we use a recently developed extension of the DWBA formalism which incorporates these core excitation effects within the no-recoil approximation. The validity of the no-recoil approximation is also examined by comparing with DWBA calculations which take into account core recoil. In addition, calculations with two different continuum representations are presented and compared.

  7. CoreFlow Scientific Solutions Ltd | Open Energy Information

    Open Energy Info (EERE)

    of non-contact substrate processing, handling, and testing equipments for Flat Panel Display (FPD), semiconductor, and solar industries. References: CoreFlow Scientific...

  8. Core Technology Ventures Services CTV | Open Energy Information

    Open Energy Info (EERE)

    An independent advisory team focused on seed and early stage companies developing fuel cell systems and hydrogen storage technologies. References: Core Technology Ventures...

  9. Solid State Lighting LED Core Technology R&D Roundtable

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

    The document should be referenced as: DOE SSL Program, "Solid State Lighting LED Core Technology R&D Roundtable," November 2015. Authors Monica Hansen LED Lighting Advisors Nnamnor ...

  10. Mikro Systems Develops Unique Ceramic Core Casting Technology...

    Office of Science (SC) Website

    Mikro Systems, Inc. developed a unique ceramic core casting technology (TOMOsm) that permits the intricate design and casting of enhanced heat transfer features on gas turbine ...

  11. Magnetic Vortex Core Reversal by Low-Field Excitations

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

    setting), scientists are looking farther down the road at completely new ways to encode binary information. Magnetic vortex cores, being thermally stable and measuring just...

  12. Core-Shell Fuel Cell Electrodes - Energy Innovation Portal

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

    Core-Shell Fuel Cell Electrodes Brookhaven National Laboratory Contact BNL About This Technology Artists rendition of the arrangement of platinum atoms in common use (left) and in ...

  13. Predictions for microlensing planetary events from core accretion theory

    SciTech Connect (OSTI)

    Zhu, Wei; Mao, Shude; Penny, Matthew; Gould, Andrew; Gendron, Rieul

    2014-06-10

    We conduct the first microlensing simulation in the context of a planet formation model. The planet population is taken from the Ida and Lin core accretion model for 0.3 M {sub ?} stars. With 6690 microlensing events, we find that for a simplified Korea Microlensing Telescopes Network (KMTNet), the fraction of planetary events is 2.9%, out of which 5.5% show multiple-planet signatures. The numbers of super-Earths, super-Neptunes, and super-Jupiters detected are expected to be almost equal. Our simulation shows that high-magnification events and massive planets are favored by planet detections, which is consistent with previous expectation. However, we notice that extremely high-magnification events are less sensitive to planets, which is possibly because the 10 minute sampling of KMTNet is not intensive enough to capture the subtle anomalies that occur near the peak. This suggests that while KMTNet observations can be systematically analyzed without reference to any follow-up data, follow-up observations will be essential in extracting the full science potential of very high magnification events. The uniformly high-cadence observations expected for KMTNet also result in ?55% of all detected planets not being caustic crossing, and more low-mass planets even down to Mars mass being detected via planetary caustics. We also find that the distributions of orbital inclinations and planet mass ratios in multiple-planet events agree with the intrinsic distributions.

  14. MIC-SVM: Designing A Highly Efficient Support Vector Machine For Advanced Modern Multi-Core and Many-Core Architectures

    SciTech Connect (OSTI)

    You, Yang; Song, Shuaiwen; Fu, Haohuan; Marquez, Andres; Mehri Dehanavi, Maryam; Barker, Kevin J.; Cameron, Kirk; Randles, Amanda; Yang, Guangwen

    2014-08-16

    Support Vector Machine (SVM) has been widely used in data-mining and Big Data applications as modern commercial databases start to attach an increasing importance to the analytic capabilities. In recent years, SVM was adapted to the field of High Performance Computing for power/performance prediction, auto-tuning, and runtime scheduling. However, even at the risk of losing prediction accuracy due to insufficient runtime information, researchers can only afford to apply offline model training to avoid significant runtime training overhead. To address the challenges above, we designed and implemented MICSVM, a highly efficient parallel SVM for x86 based multi-core and many core architectures, such as the Intel Ivy Bridge CPUs and Intel Xeon Phi coprocessor (MIC).

  15. ACHILLES: Heat Transfer in PWR Core During LOCA Reflood Phase

    SciTech Connect (OSTI)

    2013-11-01

    1. NAME AND TITLE OF DATA LIBRARY ACHILLES -Heat Transfer in PWR Core During LOCA Reflood Phase. 2. NAME AND TITLE OF DATA RETRIEVAL PROGRAMS N/A 3. CONTRIBUTOR AEA Technology, Winfrith Technology Centre, Dorchester DT2 8DH United Kingdom through the OECD Nuclear Energy Agency Data Bank, Issy-les-Moulineaux, France. 4. DESCRIPTION OF TEST FACILITY The most important features of the Achilles rig were the shroud vessel, which contained the test section, and the downcomer. These may be thought of as representing the core barrel and the annular downcomer in the reactor pressure vessel. The test section comprises a cluster of 69 rods in a square array within a circular shroud vessel. The rod diameter and pitch (9.5 mm and 12.6 mm) were typical of PWR dimensions. The internal diameter of the shroud vessel was 128 mm. Each rod was electrically heated over a length of 3.66 m, which is typical of the nuclear heated length in a PWR fuel rod, and each contained 6 internal thermocouples. These were arranged in one of 8 groupings which concentrated the thermocouples in different axial zones. The spacer grids were at prototypic PWR locations. Each grid had two thermocouples attached to its trailing edge at radial locations. The axial power profile along the rods was an 11 step approximation to a "chopped cosine". The shroud vessel had 5 heating zones whose power could be independently controlled. 5. DESCRIPTION OF TESTS The Achilles experiments investigated the heat transfer in the core of a Pressurized Water Reactor during the re-flood phase of a postulated large break loss of coolant accident. The results provided data to validate codes and to improve modeling. Different types of experiments were carried out which included single phase cooling, re-flood under low flow conditions, level swell and re-flood under high flow conditions. Three series of experiments were performed. The first and the third used the same test section but the second used another test section, similar in all respects except that it contained a partial blockage formed by attaching sleeves (or "balloons") to some of the rods. 6. SOURCE AND SCOPE OF DATA Phenomena Tested - Heat transfer in the core of a PWR during a re-flood phase of postulated large break LOCA. Test Designation - Achilles Rig. The programme includes the following types of experiments: - on an unballooned cluster: -- single phase air flow -- low pressure level swell -- low flooding rate re-flood -- high flooding rate re-flood - on a ballooned cluster containing 80% blockage formed by 16 balloon sleeves -- single phase air flow -- low flooding rate re-flood 7. DISCUSSION OF THE DATA RETRIEVAL PROGRAM N/A 8. DATA FORMAT AND COMPUTER Many Computers (M00019MNYCP00). 9. TYPICAL RUNNING TIME N/A 11. CONTENTS OF LIBRARY The ACHILLES package contains test data and associated data processing software as well as the documentation listed above. 12. DATE OF ABSTRACT November 2013. KEYWORDS: DATABASES, BENCHMARKS, HEAT TRANSFER, LOSS-OF-COLLANT ACCIDENT, PWR REACTORS, REFLOODING

  16. ACHILLES: Heat Transfer in PWR Core During LOCA Reflood Phase

    Energy Science and Technology Software Center (OSTI)

    2013-11-01

    1. NAME AND TITLE OF DATA LIBRARY ACHILLES -Heat Transfer in PWR Core During LOCA Reflood Phase. 2. NAME AND TITLE OF DATA RETRIEVAL PROGRAMS N/A 3. CONTRIBUTOR AEA Technology, Winfrith Technology Centre, Dorchester DT2 8DH United Kingdom through the OECD Nuclear Energy Agency Data Bank, Issy-les-Moulineaux, France. 4. DESCRIPTION OF TEST FACILITY The most important features of the Achilles rig were the shroud vessel, which contained the test section, and the downcomer. These maymore » be thought of as representing the core barrel and the annular downcomer in the reactor pressure vessel. The test section comprises a cluster of 69 rods in a square array within a circular shroud vessel. The rod diameter and pitch (9.5 mm and 12.6 mm) were typical of PWR dimensions. The internal diameter of the shroud vessel was 128 mm. Each rod was electrically heated over a length of 3.66 m, which is typical of the nuclear heated length in a PWR fuel rod, and each contained 6 internal thermocouples. These were arranged in one of 8 groupings which concentrated the thermocouples in different axial zones. The spacer grids were at prototypic PWR locations. Each grid had two thermocouples attached to its trailing edge at radial locations. The axial power profile along the rods was an 11 step approximation to a "chopped cosine". The shroud vessel had 5 heating zones whose power could be independently controlled. 5. DESCRIPTION OF TESTS The Achilles experiments investigated the heat transfer in the core of a Pressurized Water Reactor during the re-flood phase of a postulated large break loss of coolant accident. The results provided data to validate codes and to improve modeling. Different types of experiments were carried out which included single phase cooling, re-flood under low flow conditions, level swell and re-flood under high flow conditions. Three series of experiments were performed. The first and the third used the same test section but the second used another test section, similar in all respects except that it contained a partial blockage formed by attaching sleeves (or "balloons") to some of the rods. 6. SOURCE AND SCOPE OF DATA Phenomena Tested - Heat transfer in the core of a PWR during a re-flood phase of postulated large break LOCA. Test Designation - Achilles Rig. The programme includes the following types of experiments: - on an unballooned cluster: -- single phase air flow -- low pressure level swell -- low flooding rate re-flood -- high flooding rate re-flood - on a ballooned cluster containing 80% blockage formed by 16 balloon sleeves -- single phase air flow -- low flooding rate re-flood 7. DISCUSSION OF THE DATA RETRIEVAL PROGRAM N/A 8. DATA FORMAT AND COMPUTER Many Computers (M00019MNYCP00). 9. TYPICAL RUNNING TIME N/A 11. CONTENTS OF LIBRARY The ACHILLES package contains test data and associated data processing software as well as the documentation listed above. 12. DATE OF ABSTRACT November 2013. KEYWORDS: DATABASES, BENCHMARKS, HEAT TRANSFER, LOSS-OF-COLLANT ACCIDENT, PWR REACTORS, REFLOODING« less

  17. Solid oxide fuel cell with monolithic core

    DOE Patents [OSTI]

    McPheeters, C.C.; Mrazek, F.C.

    1988-08-02

    A solid oxide fuel cell in which fuel and oxidant gases undergo an electrochemical reaction to produce an electrical output includes a monolithic core comprised of a corrugated conductive sheet disposed between upper and lower generally flat sheets. The corrugated sheet includes a plurality of spaced, parallel, elongated slots which form a series of closed, linear, first upper and second lower gas flow channels with the upper and lower sheets within which a fuel gas and an oxidant gas respectively flow. Facing ends of the fuel cell are generally V-shaped and provide for fuel and oxidant gas inlet and outlet flow, respectively, and include inlet and outlet gas flow channels which are continuous with the aforementioned upper fuel gas and lower oxidant gas flow channels. The upper and lower flat sheets and the intermediate corrugated sheet are preferably comprised of ceramic materials and are securely coupled together such as by assembly in the green state and sintering together during firing at high temperatures. A potential difference across the fuel cell, or across a stacked array of similar fuel cells, is generated when an oxidant gas such as air and a fuel such as hydrogen gas is directed through the fuel cell at high temperatures, e.g., between 700 C and 1,100 C. 8 figs.

  18. Solid oxide fuel cell with monolithic core

    DOE Patents [OSTI]

    McPheeters, Charles C.; Mrazek, Franklin C.

    1988-01-01

    A solid oxide fuel cell in which fuel and oxidant gases undergo an electrochemical reaction to produce an electrical output includes a monolithic core comprised of a corrugated conductive sheet disposed between upper and lower generally flat sheets. The corrugated sheet includes a plurality of spaced, parallel, elongated slots which form a series of closed, linear, first upper and second lower gas flow channels with the upper and lower sheets within which a fuel gas and an oxidant gas respectively flow. Facing ends of the fuel cell are generally V-shaped and provide for fuel and oxidant gas inlet and outlet flow, respectively, and include inlet and outlet gas flow channels which are continuous with the aforementioned upper fuel gas and lower oxidant gas flow channels. The upper and lower flat sheets and the intermediate corrugated sheet are preferably comprised of ceramic materials and are securely coupled together such as by assembly in the green state and sintering together during firing at high temperatures. A potential difference across the fuel cell, or across a stacked array of similar fuel cells, is generated when an oxidant gas such as air and a fuel such as hydrogen gas is directed through the fuel cell at high temperatures, e.g., between 700.degree. C. and 1100.degree. C.

  19. Evaluating Multi-core Architectures through Accelerating the Three-Dimensional LaxWendroff Correction

    SciTech Connect (OSTI)

    You, Yang; Fu, Haohuan; Song, Shuaiwen; Mehri Dehanavi, Maryam; Gan, Lin; Huang, Xiaomeng; Yang, Guangwen

    2014-07-18

    Wave propagation forward modeling is a widely used computational method in oil and gas exploration. The iterative stencil loops in such problems have broad applications in scientific computing. However, executing such loops can be highly time time-consuming, which greatly limits applications performance and power efficiency. In this paper, we accelerate the forward modeling technique on the latest multi-core and many-core architectures such as Intel Sandy Bridge CPUs, NVIDIA Fermi C2070 GPU, NVIDIA Kepler K20x GPU, and the Intel Xeon Phi Co-processor. For the GPU platforms, we propose two parallel strategies to explore the performance optimization opportunities for our stencil kernels. For Sandy Bridge CPUs and MIC, we also employ various optimization techniques in order to achieve the best.

  20. Coupled Neutronics Thermal-Hydraulic Solution of a Full-Core PWR Using VERA-CS

    SciTech Connect (OSTI)

    Clarno, Kevin T; Palmtag, Scott; Davidson, Gregory G; Salko, Robert K; Evans, Thomas M; Turner, John A; Belcourt, Kenneth; Hooper, Russell; Schmidt, Rodney

    2014-01-01

    The Consortium for Advanced Simulation of Light Water Reactors (CASL) is developing a core simulator called VERA-CS to model operating PWR reactors with high resolution. This paper describes how the development of VERA-CS is being driven by a set of progression benchmark problems that specify the delivery of useful capability in discrete steps. As part of this development, this paper will describe the current capability of VERA-CS to perform a multiphysics simulation of an operating PWR at Hot Full Power (HFP) conditions using a set of existing computer codes coupled together in a novel method. Results for several single-assembly cases are shown that demonstrate coupling for different boron concentrations and power levels. Finally, high-resolution results are shown for a full-core PWR reactor modeled in quarter-symmetry.

  1. Star cell type core configuration for structural sandwich materials

    DOE Patents [OSTI]

    Christensen, Richard M.

    1995-01-01

    A new pattern for cellular core material used in sandwich type structural materials. The new pattern involves star shaped cells intermixed with hexagonal shaped cells. The new patterned cellular core material includes star shaped cells interconnected at points thereof and having hexagonal shape cells positioned adjacent the star points. The new pattern allows more flexibility and can conform more easily to curved shapes.

  2. Mold with improved core for metal casting operation

    DOE Patents [OSTI]

    Gritzner, Verne B.; Hackett, Donald W.

    1977-01-01

    The present invention is directed to a mold containing an improved core for use in casting hollow, metallic articles. The core is formed of, or covered with, a layer of cellular material which possesses sufficient strength to maintain its structural integrity during casting, but will crush to alleviate the internal stresses that build up if the normal contraction during solidification and cooling is restricted.

  3. Core-Shell Diamond as a Support for Solid-Phase Extraction and High-Performance Liquid Chromatography

    SciTech Connect (OSTI)

    Saini, Gaurav; Jensen, David S.; Wiest, Landon A.; Vail, Michael A.; Dadson, Andrew; Lee, Milton L.; Shutthanandan, V.; Linford, Matthew R.

    2010-06-01

    We report the formation of core-shell diamond particles for solid phase extraction (SPE) and high performance liquid chromatography (HPLC) made by layer-by-layer (LbL) deposition. Their synthesis begins with the amine functionalization of microdiamond by its immersion in an aqueous solution of a primary amine-containing polymer (polyallylamine (PAAm)). The amine-terminated microdiamond is then immersed in an aqueous suspension of nanodiamond, which leads to adsorption of the nanodiamond. Alternating (self-limiting) immersions in the solutions of the amine-containing polymer and the suspension of nanodiamond are continued until the desired number of nanodiamond layers is formed around the microdiamond. Finally, the core-shell particles are cross-linked with 1,2,5,6-diepoxycyclooctane or reacted with 1,2-epoxyoctadecane. Layer-by-layer deposition of PAAm and nanodiamond is also studied on planar Si/SiO2 surfaces, which were characterized by SEM, Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis (NRA). Core-shell particles are characterized by diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), environmental scanning electron microscopy (ESEM), and Brunauer Emmett Teller (BET) surface area and pore size measurements. Larger (ca. 50 ?m) core-shell diamond particles have much higher surface areas, and analyte loading capacities in SPE than nonporous solid diamond particles. Smaller (ca. 3 ?m), normal and reversed phase, core-shell diamond particles have been used for HPLC, with 36,300 plates per meter for mesitylene in a separation of benzene and alkyl benzenes on a C18 adsorbent, and 54,800 plates per meter for diazinon in a similar separation of two pesticides.

  4. Process to make core-shell structured nanoparticles

    DOE Patents [OSTI]

    Luhrs, Claudia; Phillips, Jonathan; Richard, Monique N

    2014-01-07

    Disclosed is a process for making a composite material that contains core-shell structured nanoparticles. The process includes providing a precursor in the form of a powder a liquid and/or a vapor of a liquid that contains a core material and a shell material, and suspending the precursor in an aerosol gas to produce an aerosol containing the precursor. In addition, the process includes providing a plasma that has a hot zone and passing the aerosol through the hot zone of the plasma. As the aerosol passes through the hot zone of the plasma, at least part of the core material and at least part of the shell material in the aerosol is vaporized. Vapor that contains the core material and the shell material that has been vaporized is removed from the hot zone of the plasma and allowed to condense into core-shell structured nanoparticles.

  5. Advanced Core Design And Fuel Management For Pebble-Bed Reactors

    SciTech Connect (OSTI)

    Hans D. Gougar; Abderrafi M. Ougouag; William K. Terry

    2004-10-01

    A method for designing and optimizing recirculating pebble-bed reactor cores is presented. At the heart of the method is a new reactor physics computer code, PEBBED, which accurately and efficiently computes the neutronic and material properties of the asymptotic (equilibrium) fuel cycle. This core state is shown to be unique for a given core geometry, power level, discharge burnup, and fuel circulation policy. Fuel circulation in the pebble-bed can be described in terms of a few well?defined parameters and expressed as a recirculation matrix. The implementation of a few heat?transfer relations suitable for high-temperature gas-cooled reactors allows for the rapid estimation of thermal properties critical for safe operation. Thus, modeling and design optimization of a given pebble-bed core can be performed quickly and efficiently via the manipulation of a limited number key parameters. Automation of the optimization process is achieved by manipulation of these parameters using a genetic algorithm. The end result is an economical, passively safe, proliferation-resistant nuclear power plant.

  6. CO2 flood tests on whole core samples of the Mt. Simon sandstone, Illinois Basin

    SciTech Connect (OSTI)

    O'Connor, William K.; Rush, Gilbert E.

    2005-09-01

    Geological sequestration of CO2, whether by enhanced oil recovery (EOR), coal-bed methane (CBM) recovery, or saline aquifer injection is a promising near-term sequestration methodology. While tremendous experience exists for EOR, and CBM recovery has been demonstrated in existing fields, saline aquifer injection studies have only recently been initiated. Studies evaluating the availability of saline aquifers suitable for CO2 injection show great potential, however, the long-term fate of the CO2 injected into these ancient aqueous systems is still uncertain. For the subject study, a series of laboratory-scale CO2 flood tests were conducted on whole core samples of the Mt. Simon sandstone from the Illinois Basin. By conducting these tests on whole core samples rather than crushed core, an evaluation of the impact of the CO2 flood on the rock mechanics properties as well as the geochemistry of the core and brine solution has been possible. This empirical data could provide a valuable resource for the validation of reservoir models under development for these engineered CO2 systems.

  7. Multi-model Mean Nitrogen and Sulfur Deposition from the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP): Evaluation of Historical and Projected Future Changes

    SciTech Connect (OSTI)

    Lamarque, Jean-Francois; Dentener, Frank; McConnell, J.R.; Ro, C-U; Shaw, Mark; Vet, Robert; Bergmann, D.; Cameron-Smith, Philip; Dalsoren, S.; Doherty, R.; Faluvegi, G.; Ghan, Steven J.; Josse, B.; Lee, Y. H.; MacKenzie, I. A.; Plummer, David; Shindell, Drew; Skeie, R. B.; Stevenson, D. S.; Strode, S.; Zeng, G.; Curran, M.; Dahl-Jensen, D.; Das, S.; Fritzsche, D.; Nolan, M.

    2013-08-20

    We present multi-model global datasets of nitrogen and sulfate deposition covering time periods from 1850 to 2100, calculated within the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP). The computed deposition fluxes are compared to surface wet deposition and ice-core measurements. We use a new dataset of wet deposition for 2000-2002 based on critical assessment of the quality of existing regional network data. We show that for present-day (year 2000 ACCMIP time-slice), the ACCMIP results perform similarly to previously published multi-model assessments. The analysis of changes between 1980 and 2000 indicates significant differences between model and measurements over the United States, but less so over Europe. This difference points towards misrepresentation of 1980 NH3 emissions over North America. Based on ice-core records, the 1850 deposition fluxes agree well with Greenland ice cores but the change between 1850 and 2000 seems to be overestimated in the Northern Hemisphere for both nitrogen and sulfur species. Using the Representative Concentration Pathways to define the projected climate and atmospheric chemistry related emissions and concentrations, we find large regional nitrogen deposition increases in 2100 in Latin America, Africa and parts of Asia under some of the scenarios considered. Increases in South Asia are especially large, and are seen in all scenarios, with 2100 values more than double 2000 in some scenarios and reaching >1300 mgN/m2/yr averaged over regional to continental scale regions in RCP 2.6 and 8.5, ~30-50% larger than the values in any region currently (2000). Despite known issues, the new ACCMIP deposition dataset provides novel, consistent and evaluated global gridded deposition fields for use in a wide range of climate and ecological studies.

  8. Pre-conceptual design study of ASTRID core

    SciTech Connect (OSTI)

    Varaine, F.; Marsault, P.; Chenaud, M. S.; Bernardin, B.; Conti, A.; Sciora, P.; Venard, C.; Fontaine, B.; Devictor, N.; Martin, L.; Scholer, A. C.; Verrier, D.

    2012-07-01

    In the framework of the ASTRID project at CEA, core design studies are performed at CEA with the AREVA and EDF support. At the stage of the project, pre-conceptual design studies are conducted in accordance with GEN IV reactors criteria, in particularly for safety improvements. An improved safety for a sodium cooled reactor requires revisiting many aspects of the design and is a rather lengthy process in current design approach. Two types of cores are under evaluation, one classical derived from the SFR V2B and one more challenging called CFV (low void effect core) with a large gain on the sodium void effect. The SFR V2b core have the following specifications: a very low burn-up reactivity swing (due to a small cycle reactivity loss) and a reduced sodium void effect with regard to past designs such as the EFR (around 2$ minus). Its performances are an average burn-up of 100 GWd/t, and an internal conversion ratio equal to one given a very good behavior of this core during a control rod withdrawal transient). The CFV with its specific design offers a negative sodium void worth while maintaining core performances. In accordance of ASTRID needs for demonstration those cores are 1500 MWth power (600 MWe). This paper will focus on the CFV pre-conceptual design of the core and S/A, and the performances in terms of safety will be evaluated on different transient scenario like ULOF, in order to assess its intrinsic behavior compared to a more classical design like V2B core. The gap in term of margin to a severe accident due to a loss of flow initiator underlines the potential capability of this type of core to enhance prevention of severe accident in accordance to safety demonstration. (authors)

  9. Assessment of RELAP5/MOD3.1 for gravity-driven injection experiment in the core makeup tank of the CARR Passive Reactor (CP-1300)

    SciTech Connect (OSTI)

    Lee, S.I.; No, H.C.; Bang, Y.S.; Kim, H.J.

    1996-10-01

    The objective of the present work is to improve the analysis capability of RELAP5/MOD3.1 on the direct contact condensation in the core makeup tank (CMT) of passive high-pressure injection system (PHPIS) in the CARR Passive Reactor (CP-1300). The gravity-driven injection experiment is conducted by using a small scale test facility to identify the parameters having significant effects on the gravity-driven injection and the major condensation modes. It turns out that the larger the water subcooling is, the more initiation of injection is delayed, and the sparger and the natural circulation of the hot water from the steam generator accelerate the gravity-driven injection. The condensation modes are divided into three modes: sonic jet, subsonic jet, and steam cavity. RELAP5/MOD3.1 is chosen to evaluate the cod predictability on the direct contact condensation in the CMT. It is found that the predictions of MOD3.1 are in better agreement with the experimental data than those of MOD3.0. From the nodalization study of the test section, the 1-node model shows better agreement with the experimental data than the multi-node models. RELAP5/MOD3.1 identifies the flow regime of the test section as vertical stratification. However, the flow regime observed in the experiment is the subsonic jet with the bubble having the vertical cone shape. To accurately predict the direct contact condensation in the CMT with RELAP5/MOD3.1, it is essential that a new set of the interfacial heat transfer coefficients and a new flow regime map for direct contact condensation in the CMT be developed.

  10. FY13 Annual Progress Report for SECA Core Technology Program

    SciTech Connect (OSTI)

    Stevenson, Jeffry W.; Koeppel, Brian J.

    2014-01-31

    This progress report covers technical work performed during fiscal year 2013 at PNNL under Field Work Proposal (FWP) 40552. The report highlights and documents technical progress in tasks related to advanced cell and stack component materials development and computational design and simulation. Primary areas of emphasis for the materials development work were metallic interconnects and coatings, cathode and anode stability/degradation, glass seals, and advanced testing under realistic stack conditions: Metallic interconnects and coatings • Effects of surface modifications to AISI 441 (prior to application of protective spinel coatings) on oxide scale growth and adhesion were evaluated as a function of temperature and time. Cathode stability/degradation • Effects of cathode air humidity on performance and stability of SOFC cathodes were investigated by testing anode-supported cells as a function of time and temperature. • In-situ high temperature XRD measurements were used to correlate changes in cathode lattice structure and composition with performance of anode-supported button cells. Anode stability/degradation • Effects of high fuel steam content on Ni/YSZ anodes were investigated over a range of time and temperature. • Vapor infiltration and particulate additions were evaluated as a potential means of improving tolerance of Ni/YSZ anodes to sulfur-bearing fuel species. Glass seals • A candidate compliant glass-based seal materials were evaluated in terms of microstructural evolution and seal performance as a function of time and temperature. Stack fixture testing • The SECA CTP stack test fixture was used for intermediate and long-term evaluation of candidate materials and processes. Primary areas of emphasis for the computational modeling work were coarse methodology, degradation of stack components, and electrochemical modeling: Coarse methodology • Improvements were made to both the SOFC-MP and SOFC ROM simulation tools. Degradation of stack components • Thermo-mechanical modeling and validation experiments were performed to understand/mitigate degradation of interconnects and seals during long-term stack operation. Electrochemical modeling 4 • Modeling tools were developed to improve understanding of electrochemical performance degradation of SOFCs related to changes in electrode microstructure and chemical interactions with contaminants. During FY13, PNNL continued to work with NETL to increase the extent of interaction between the SECA Core Technology Program and the SECA Industry Teams. In addition to using established mechanisms of communication, such as the annual SECA Workshop, representatives from PNNL and NETL participated in telecons and/or face-to-face meetings with all three industry teams during FY13. During these meetings, PNNL’s Core Technology Program work was presented in detail, after which feedback was solicited regarding current and future research topics. Results of PNNL’s SECA CTP work were also distributed via topical reports for the industry teams, DOE reports, technical society presentations, and papers in peer-reviewed technical journals. 5

  11. Comparison of prestellar core elongations and large-scale molecular cloud structures in the Lupus I region

    SciTech Connect (OSTI)

    Poidevin, Frdrick; Ade, Peter A. R.; Hargrave, Peter C.; Nutter, David; Angile, Francesco E.; Devlin, Mark J.; Klein, Jeffrey; Benton, Steven J.; Netterfield, Calvin B.; Chapin, Edward L.; Fissel, Laura M.; Gandilo, Natalie N.; Fukui, Yasuo; Gundersen, Joshua O.; Korotkov, Andrei L.; Matthews, Tristan G.; Novak, Giles; Moncelsi, Lorenzo; Mroczkowski, Tony K.; Olmi, Luca; and others

    2014-08-10

    Turbulence and magnetic fields are expected to be important for regulating molecular cloud formation and evolution. However, their effects on sub-parsec to 100 parsec scales, leading to the formation of starless cores, are not well understood. We investigate the prestellar core structure morphologies obtained from analysis of the Herschel-SPIRE 350 ?m maps of the Lupus I cloud. This distribution is first compared on a statistical basis to the large-scale shape of the main filament. We find the distribution of the elongation position angle of the cores to be consistent with a random distribution, which means no specific orientation of the morphology of the cores is observed with respect to the mean orientation of the large-scale filament in Lupus I, nor relative to a large-scale bent filament model. This distribution is also compared to the mean orientation of the large-scale magnetic fields probed at 350 ?m with the Balloon-borne Large Aperture Telescope for Polarimetry during its 2010 campaign. Here again we do not find any correlation between the core morphology distribution and the average orientation of the magnetic fields on parsec scales. Our main conclusion is that the local filament dynamicsincluding secondary filaments that often run orthogonally to the primary filamentand possibly small-scale variations in the local magnetic field direction, could be the dominant factors for explaining the final orientation of each core.

  12. An In-Core Power Deposition and Fuel Thermal Environmental Monitor for Long-Lived Reactor Cores

    SciTech Connect (OSTI)

    Don W. Miller

    2004-09-28

    The primary objective of this program is to develop the Constant Temperature Power Sensor (CTPS) as in-core instrumentation that will provide a detailed map of local nuclear power deposition and coolant thermal-hydraulic conditions during the entire life of the core.

  13. Relationships Between Complex Core Level Spectra and Materials Properties

    SciTech Connect (OSTI)

    Nelin, Constance J.; Bagus, Paul S.; Ilton, Eugene S.; Chambers, Scott A.; Kuhlenbeck, Helmut; Freund, Hans-Joachim

    2010-12-01

    The XPS of many oxides are quite complex and there may be several peaks of significant intensity for each subshell. These peaks arise from many-electron effects, which normally are treated with configuration interaction (CI) wavefunctions where static correlation effects are taken into account. It is common to use semiempirical methods to determine the matrix elements of the CI Hamiltonian and there are few rigorous CI calculations where parameters are not adjusted to fit experiment. In contrast, we present, in the present work, theoretical XPS spectra obtained with rigorous CI wavefunctions for CeO2 where the XPS are especially complex; several different core levels are studied. This study uses an embedded CeO8 cluster model to represent bulk CeO2 and the relativistic CI wavefunctions are determined using four-component spinors from Dirac-Fock calculations. In particular, we examine the importance of interatomic many-body effects where there is a transfer of electrons from occupied oxygen 2p orbitals into empty cation orbitals as it is common to ascribe the complex XPS to this effect. We also contrast the importance of many-body charge-transfer effects for the isoelectronic cations of Ce4+ and La3+. The long-range goal of this work is to relate the XPS features to the nature of the chemical bonding in CeO2 and we describe our progress toward this goal.

  14. GRAVITATIONAL WAVE SIGNATURES IN BLACK HOLE FORMING CORE COLLAPSE

    SciTech Connect (OSTI)

    Cerd-Durn, Pablo; DeBrye, Nicolas; Aloy, Miguel A.; Font, Jos A.; Obergaulinger, Martin

    2013-12-20

    We present general relativistic numerical simulations of collapsing stellar cores. Our initial model consists of a low metallicity rapidly-rotating progenitor which is evolved in axisymmetry with the latest version of our general relativistic code CoCoNuT, which allows for black hole formation and includes the effects of a microphysical equation of state (LS220) and a neutrino leakage scheme to account for radiative losses. The motivation of our study is to analyze in detail the emission of gravitational waves in the collapsar scenario of long gamma-ray bursts. Our simulations show that the phase during which the proto-neutron star (PNS) survives before ultimately collapsing to a black hole is particularly optimal for gravitational wave emission. The high-amplitude waves last for several seconds and show a remarkable quasi-periodicity associated with the violent PNS dynamics, namely during the episodes of convection and the subsequent nonlinear development of the standing-accretion shock instability (SASI). By analyzing the spectrogram of our simulations we are able to identify the frequencies associated with the presence of g-modes and with the SASI motions at the PNS surface. We note that the gravitational waves emitted reach large enough amplitudes to be detected with third-generation detectors such as the Einstein Telescope within a Virgo Cluster volume at rates ? 0.1yr{sup 1}.

  15. Irradiation-Accelerated Corrosion of Reactor Core Materials. Final Report

    SciTech Connect (OSTI)

    Jiao, Zhujie; Was, Gary; Bartels, David

    2015-04-02

    This project aims to understand how radiation accelerates corrosion of reactor core materials. The combination of high temperature, chemically aggressive coolants, a high radiation flux and mechanical stress poses a major challenge for the life extension of current light water reactors, as well as the success of most all GenIV concepts. Of these four drivers, the combination of radiation and corrosion places the most severe demands on materials, for which an understanding of the fundamental science is simply absent. Only a few experiments have been conducted to understand how corrosion occurs under irradiation, yet the limited data indicates that the effect is large; irradiation causes order of magnitude increases in corrosion rates. Without a firm understanding of the mechanisms by which radiation and corrosion interact in film formation, growth, breakdown and repair, the extension of the current LWR fleet beyond 60 years and the success of advanced nuclear energy systems are questionable. The proposed work will address the process of irradiation-accelerated corrosion that is important to all current and advanced reactor designs, but remains very poorly understood. An improved understanding of the role of irradiation in the corrosion process will provide the community with the tools to develop predictive models for in-reactor corrosion, and to address specific, important forms of corrosion such as irradiation assisted stress corrosion cracking.

  16. Cutting-edge issues of core-collapse supernova theory

    SciTech Connect (OSTI)

    Kotake, Kei; Nakamura, Ko; Kuroda, Takami; Takiwaki, Tomoya

    2014-05-02

    Based on multi-dimensional neutrino-radiation hydrodynamic simulations, we report several cutting-edge issues about the long-veiled explosion mechanism of core-collapse supernovae (CCSNe). In this contribution, we pay particular attention to whether three-dimensional (3D) hydrodynamics and/or general relativity (GR) would or would not help the onset of explosions. By performing 3D simulations with spectral neutrino transport, we show that it is more difficult to obtain an explosion in 3D than in 2D. In addition, our results from the first generation of full general relativistic 3D simulations including approximate neutrino transport indicate that GR can foster the onset of neutrino-driven explosions. Based on our recent parametric studies using a light-bulb scheme, we discuss impacts of nuclear energy deposition behind the supernova shock and stellar rotation on the neutrino-driven mechanism, both of which have yet to be included in the self-consistent 3D supernova models. Finally we give an outlook with a summary of the most urgent tasks to extract the information about the explosion mechanisms from multi-messenger CCSN observables.

  17. One pass core design of a super fast reactor

    SciTech Connect (OSTI)

    Liu, Qingjie; Oka, Yoshiaki

    2013-07-01

    One pass core design for Supercritical-pressure light water-cooled fast reactor (Super FR) is proposed. The whole core is cooled with upward flow in one through flow pattern like PWR. Compared with the previous two pass core design; this new flow pattern can significantly simplify the core concept. Upper core structure, coolant flow scheme as well as refueling procedure are as simple as in PWR. In one pass core design, supercritical-pressure water is at approximately 25.0 MPa and enters the core at 280 C. degrees and is heated up in one through flow pattern upwardly to the average outlet temperature of 500 C. degrees. Great density change in vertical direction can cause significant axial power offset during the cycle. Meanwhile, Pu accumulated in the UO{sub 2} fuel blanket assemblies also introduces great power increase during cycle, which requires large amount of flow for heat removal and makes the outlet temperature of blanket low at the beginning of equilibrium cycle (BOEC). To deal with these issues, some MOX fuel is applied in the bottom region of the blanket assembly. This can help to mitigate the power change in blanket due to Pu accumulation and to increase the outlet temperature of the blanket during cycle. Neutron transport and thermohydraulics coupled calculation shows that this design can satisfy the requirement in the Super FR principle for both 500 C. degrees outlet temperature and negative coolant void reactivity. (authors)

  18. Concentric core optical fiber with multiple-mode signal transmission

    DOE Patents [OSTI]

    Muhs, J.D.

    1997-05-06

    A concentric core optical fiber provides for the simultaneous but independent transmission of signals over a single optical fiber. The concentric optical fiber is constructed of a single-mode or multimode inner optical fiber defined by a core and a cladding of a lower index of refraction than the core and an outer optical fiber defined by additional cladding concentrically disposed around the cladding and of an index of refraction lower than the first mentioned cladding whereby the latter functions as the core of the outer optical fiber. By employing such an optical fiber construction with a single-mode inner core or optical fiber, highly sensitive interferometric and stable less sensitive amplitude based sensors can be placed along the same length of a concentric core optical fiber. Also, by employing the concentric core optical fiber secure telecommunications can be achieved via the inner optical fiber since an intrusion of the concentric optical fiber will first cause a variation in the light being transmitted through the outer optical fiber and this variation of light being used to trigger a suitable alarm indicative of the intrusion. 3 figs.

  19. Concentric core optical fiber with multiple-mode signal transmission

    DOE Patents [OSTI]

    Muhs, Jeffrey D.

    1997-01-01

    A concentric core optical fiber provides for the simultaneous but independent transmission of signals over a single optical fiber. The concentric optical fiber is constructed of a single-mode or multimode inner optical fiber defined by a core and a cladding of a lower index of refraction than the core and an outer optical fiber defined by additional cladding concentrically disposed around the cladding and of an index of refraction lower than the first mentioned cladding whereby the latter functions as the core of the outer optical fiber. By employing such an optical fiber construction with a single-mode inner core or optical fiber, highly sensitive interferometric and stable less sensitive amplitude based sensors can be placed along the same length of a concentric core optical fiber. Also, by employing the concentric core optical fiber secure telecommunications can be achieved via the inner optical fiber since an intrusion of the concentric optical fiber will first cause a variation in the light being transmitted through the outer optical fiber and this variation of light being used to trigger a suitable alarm indicative of the intrusion.

  20. TREAT Transient Analysis Benchmarking for the HEU Core

    SciTech Connect (OSTI)

    Kontogeorgakos, D. C.; Connaway, H. M.; Wright, A. E.

    2014-05-01

    This work was performed to support the feasibility study on the potential conversion of the Transient Reactor Test Facility (TREAT) at Idaho National Laboratory from the use of high enriched uranium (HEU) fuel to the use of low enriched uranium (LEU) fuel. The analyses were performed by the GTRI Reactor Conversion staff at the Argonne National Laboratory (ANL). The objective of this study was to benchmark the transient calculations against temperature-limited transients performed in the final operating HEU TREAT core configuration. The MCNP code was used to evaluate steady-state neutronics behavior, and the point kinetics code TREKIN was used to determine core power and energy during transients. The first part of the benchmarking process was to calculate with MCNP all the neutronic parameters required by TREKIN to simulate the transients: the transient rod-bank worth, the prompt neutron generation lifetime, the temperature reactivity feedback as a function of total core energy, and the core-average temperature and peak temperature as a functions of total core energy. The results of these calculations were compared against measurements or against reported values as documented in the available TREAT reports. The heating of the fuel was simulated as an adiabatic process. The reported values were extracted from ANL reports, intra-laboratory memos and experiment logsheets and in some cases it was not clear if the values were based on measurements, on calculations or a combination of both. Therefore, it was decided to use the term reported values when referring to such data. The methods and results from the HEU core transient analyses will be used for the potential LEU core configurations to predict the converted (LEU) cores performance.

  1. Critical surface for explosions of rotational core-collapse supernovae

    SciTech Connect (OSTI)

    Iwakami, Wakana; Nagakura, Hiroki [Yukawa Institute for Theoretical Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto, 606-8502 (Japan); Yamada, Shoichi, E-mail: wakana@heap.phys.waseda.ac.jp [Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1, Okubo, Shinjuku, Tokyo, 169-8555 (Japan)

    2014-09-20

    The effect of rotation on the explosion of core-collapse supernovae is investigated systematically in three-dimensional simulations. In order to obtain the critical conditions for explosion as a function of mass accretion rate, neutrino luminosity, and specific angular momentum, rigidly rotating matter was injected from the outer boundary with an angular momentum, which is increased every 500 ms. It is found that there is a critical value of the specific angular momentum, above which the standing shock wave revives, for a given combination of mass accretion rate and neutrino luminosity, i.e., an explosion can occur by rotation even if the neutrino luminosity is lower than the critical value for a given mass accretion rate in non-rotational models. The coupling of rotation and hydrodynamical instabilities plays an important role in characterizing the dynamics of shock revival for the range of specific angular momentum that are supposed to be realistic. Contrary to expectations from past studies, the most rapidly expanding direction of the shock wave is not aligned with the rotation axis. Being perpendicular to the rotation axis on average, it can be oriented in various directions. Its dispersion is small when the spiral mode of the standing accretion shock instability (SASI) governs the dynamics, while it is large when neutrino-driven convection is dominant. As a result of the comparison between two-dimensional and three-dimensional rotational models, it is found that m ? 0 modes of neutrino-driven convection or SASI are important for shock revival around the critical surface.

  2. Burnup concept for a long-life fast reactor core using MCNPX.

    SciTech Connect (OSTI)

    Holschuh, Thomas Vernon,; Lewis, Tom Goslee,; Parma, Edward J.,

    2013-02-01

    This report describes a reactor design with a burnup concept for a long-life fast reactor core that was evaluated using Monte Carlo N-Particle eXtended (MCNPX). The current trend in advanced reactor design is the concept of a small modular reactor (SMR). However, very few of the SMR designs attempt to substantially increase the lifetime of a reactor core, especially without zone loading, fuel reshuffling, or other artificial mechanisms in the core that %E2%80%9Cflatten%E2%80%9D the power profile, including non-uniform cooling, non-uniform moderation, or strategic poison placement. Historically, the limitations of computing capabilities have prevented acceptable margins in the temporal component of the spatial excess reactivity in a reactor design, due primarily to the error in burnup calculations. This research was performed as an initial scoping analysis into the concept of a long-life fast reactor. It can be shown that a long-life fast reactor concept can be modeled using MCNPX to predict burnup and neutronics behavior. The inherent characteristic of this conceptual design is to minimize the change in reactivity over the lifetime of the reactor. This allows the reactor to operate substantially longer at full power than traditional Light Water Reactors (LWRs) or other SMR designs. For the purpose of this study, a single core design was investigated: a relatively small reactor core, yielding a medium amount of power (~200 to 400 MWth). The results of this scoping analysis were successful in providing a preliminary reactor design involving metal U-235/U-238 fuel with HT-9 fuel cladding and sodium coolant at a 20% volume fraction.

  3. THE BLUE STRAGGLER STAR POPULATION IN NGC1261: EVIDENCE FOR A POST-CORE-COLLAPSE BOUNCE STATE

    SciTech Connect (OSTI)

    Simunovic, Mirko; Puzia, Thomas H.; Sills, Alison E-mail: tpuzia@astro.puc.cl

    2014-11-01

    We present a multi-passband photometric study of the Blue Straggler Star (BSS) population in the Galactic globular cluster (GC) NGC1261, using available space- and ground-based survey data. The inner BSS population is found to have two distinct sequences in the color-magnitude diagram (CMD), similar to double BSS sequences detected in other GCs. These well defined sequences are presumably linked to single short-lived events such as core collapse, which are expected to boost the formation of BSSs. In agreement with this, we find a BSS sequence in NGC1261 which can be well reproduced individually by a theoretical model prediction of a 2 Gyr old population of stellar collision products, which are expected to form in the denser inner regions during short-lived core contraction phases. Additionally, we report the occurrence of a group of BSSs with unusually blue colors in the CMD, which are consistent with a corresponding model of a 200Myr old population of stellar collision products. The properties of the NGC1261 BSS populations, including their spatial distributions, suggest an advanced dynamical evolutionary state of the cluster, but the core of this GC does not show the classical signatures of core collapse. We argue that these apparent contradictions provide evidence for a post-core-collapse bounce state seen in dynamical simulations of old GCs.

  4. Ignitability testing for core drilling system. Final report

    SciTech Connect (OSTI)

    Cashdollar, K.L.; Furno, A.; Green, G.M.; Thomas, R.A.; Witwer, K.S.

    1995-06-15

    As part of a study of the hazards of the inspection of nuclear waste material stored at the Hanford, WA site, the Department of Energy (DOE) and Westinghouse Hanford Company (WHC) have developed a core drilling system to sample the material in large waste storage tanks. In support of this work, the US Bureau of Mines has studied the probability of ignition while core drilling into simulated salt cake that was permeated with a flammable gas mixture. No ignitions were observed while core drilling into the saltcake with or without a purge gas and no ignitions were observed while drilling into a steel plate.

  5. Evidence for a Weak Iron Core at Earth's Center

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

    Evidence for a Weak Iron Core at Earth's Center Print Seismic waves that pass through the center of the Earth travel faster going from pole to pole than along the equatorial plane-why? One theory is that the grains of iron that make up most of the solid inner core could be aligned in a way that transmits waves more efficiently in one direction than the other. Recent evidence for this "texturing" of iron grains in the Earth's inner core comes from x-ray spectroscopy and diffraction

  6. Evidence for a Weak Iron Core at Earth's Center

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

    Evidence for a Weak Iron Core at Earth's Center Print Seismic waves that pass through the center of the Earth travel faster going from pole to pole than along the equatorial plane-why? One theory is that the grains of iron that make up most of the solid inner core could be aligned in a way that transmits waves more efficiently in one direction than the other. Recent evidence for this "texturing" of iron grains in the Earth's inner core comes from x-ray spectroscopy and diffraction

  7. Evidence for a Weak Iron Core at Earth's Center

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

    Evidence for a Weak Iron Core at Earth's Center Print Seismic waves that pass through the center of the Earth travel faster going from pole to pole than along the equatorial plane-why? One theory is that the grains of iron that make up most of the solid inner core could be aligned in a way that transmits waves more efficiently in one direction than the other. Recent evidence for this "texturing" of iron grains in the Earth's inner core comes from x-ray spectroscopy and diffraction

  8. Evidence for a Weak Iron Core at Earth's Center

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

    Evidence for a Weak Iron Core at Earth's Center Print Seismic waves that pass through the center of the Earth travel faster going from pole to pole than along the equatorial plane-why? One theory is that the grains of iron that make up most of the solid inner core could be aligned in a way that transmits waves more efficiently in one direction than the other. Recent evidence for this "texturing" of iron grains in the Earth's inner core comes from x-ray spectroscopy and diffraction

  9. Evidence for a Weak Iron Core at Earth's Center

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

    Evidence for a Weak Iron Core at Earth's Center Evidence for a Weak Iron Core at Earth's Center Print Wednesday, 30 April 2014 00:00 Seismic waves that pass through the center of the Earth travel faster going from pole to pole than along the equatorial plane-why? One theory is that the grains of iron that make up most of the solid inner core could be aligned in a way that transmits waves more efficiently in one direction than the other. Recent evidence for this "texturing" of iron

  10. Evidence for a Weak Iron Core at Earth's Center

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

    Evidence for a Weak Iron Core at Earth's Center Print Seismic waves that pass through the center of the Earth travel faster going from pole to pole than along the equatorial plane-why? One theory is that the grains of iron that make up most of the solid inner core could be aligned in a way that transmits waves more efficiently in one direction than the other. Recent evidence for this "texturing" of iron grains in the Earth's inner core comes from x-ray spectroscopy and diffraction

  11. Evidence for a Weak Iron Core at Earth's Center

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

    Evidence for a Weak Iron Core at Earth's Center Print Seismic waves that pass through the center of the Earth travel faster going from pole to pole than along the equatorial plane-why? One theory is that the grains of iron that make up most of the solid inner core could be aligned in a way that transmits waves more efficiently in one direction than the other. Recent evidence for this "texturing" of iron grains in the Earth's inner core comes from x-ray spectroscopy and diffraction

  12. CORE ELECTRON HEATING IN SOLAR WIND RECONNECTION EXHAUSTS

    SciTech Connect (OSTI)

    Pulupa, M. P.; Salem, C.; Phan, T. D.; Bale, S. D.; Gosling, J. T.

    2014-08-10

    We present observational evidence of core electron heating in solar wind reconnection exhausts. We show two example events, one which shows clear heating of the core electrons within the exhaust, and one which demonstrates no heating. The event with heating occurred during a period of high inflow Alfvn speed (V {sub AL}), while the event with no heating had a low V {sub AL}. This agrees with the results of a recent study of magnetopause exhausts, and suggests that similar core electron heating can occur in both symmetric (solar wind) and asymmetric (magnetopause) exhausts.

  13. Magnetic Vortex Core Reversal by Low-Field Excitations

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

    Magnetic Vortex Core Reversal by Low-Field Excitations Magnetic Vortex Core Reversal by Low-Field Excitations Print Wednesday, 28 March 2007 00:00 In micrometer-sized magnetic thin films, the magnetization typically adopts an in-plane, circular configuration known as a magnetic vortex. At the vortex core, the magnetization turns sharply out of the plane, pointing either up or down. Magnetic data storage based on this binary phenomenon is an intriguing concept, but it would require the ability to

  14. Co-electrospinning fabrication and photocatalytic performance of TiO{sub 2}/SiO{sub 2} core/sheath nanofibers with tunable sheath thickness

    SciTech Connect (OSTI)

    Cao, Houbao Du, Pingfan; Song, Lixin; Xiong, Jie Yang, Junjie; Xing, Tonghai; Liu, Xin; Wu, Rongrong; Wang, Minchao; Shao, Xiaoli

    2013-11-15

    Graphical abstract: - Highlights: The coresheath TiO{sub 2}/SiO{sub 2} nanofibers were fabricated by co-electrospinning technique. The catalytic property of nanofibers with different sheath thickness was studied. The potential methods of improving catalytic efficiency are suggested. - Abstract: In this paper, core/sheath TiO{sub 2}/SiO{sub 2} nanofibers with tunable sheath thickness were directly fabricated via a facile co-electrospinning technique with subsequent calcination at 500 C. The morphologies and structures of core/sheath TiO{sub 2}/SiO{sub 2} nanofibers were characterized by TGA, FESEM, TEM, FTIR, XPS and BET. It was found that the 1D core/sheath nanofibers are made up of anataserutile TiO{sub 2} core and amorphous SiO{sub 2} sheath. The influences of SiO{sub 2} sheath and its thickness on the photoreactivity were evaluated by observing photo-degradation of methylene blue aqueous solution under the irradiation of UV light. Compared with pure TiO{sub 2} nanofibers, the core/sheath TiO{sub 2}/SiO{sub 2} nanofibers performed a better catalytic performance. That was attributed to not only efficient separation of holeelectron pairs resulting from the formation of heterojunction but also larger surface area and surface silanol group which will be useful to provide higher capacity for oxygen adsorption to generate more hydroxyl radicals. And the optimized core/sheath TiO{sub 2}/SiO{sub 2} nanofibers with a sheath thickness of 37 nm exhibited the best photocatalytic performance.

  15. Apparatus and method for controlling the temperature of the core of a super-conducting transformer

    DOE Patents [OSTI]

    Golner, Thomas; Pleva, Edward; Mehta, Shirish

    2006-10-10

    An apparatus for controlling the temperature of a core of a transformer is provided that includes a core, a shield surrounding the core, a cast formed between the core and the shield, and tubing positioned on the shield. The cast directs heat from the core to the shield and cooling fluid is directed through the tubing to cool the shield.

  16. TREAT Modeling and Simulation Strategy

    SciTech Connect (OSTI)

    DeHart, Mark David

    2015-09-01

    This report summarizes a four-phase process used to describe the strategy in developing modeling and simulation software for the Transient Reactor Test Facility. The four phases of this research and development task are identified as (1) full core transient calculations with feedback, (2) experiment modeling, (3) full core plus experiment simulation and (4) quality assurance. The document describes the four phases, the relationship between these research phases, and anticipated needs within each phase.

  17. Evaluation of Neutron Radiography Reactor LEU-Core Start-Up Measurements

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

    Bess, John D.; Maddock, Thomas L.; Smolinski, Andrew T.; Marshall, Margaret A.

    2014-11-04

    Benchmark models were developed to evaluate the cold-critical start-up measurements performed during the fresh core reload of the Neutron Radiography (NRAD) reactor with Low Enriched Uranium (LEU) fuel. Experiments include criticality, control-rod worth measurements, shutdown margin, and excess reactivity for four core loadings with 56, 60, 62, and 64 fuel elements. The worth of four graphite reflector block assemblies and an empty dry tube used for experiment irradiations were also measured and evaluated for the 60-fuel-element core configuration. Dominant uncertainties in the experimental keff come from uncertainties in the manganese content and impurities in the stainless steel fuel cladding asmore » well as the 236U and erbium poison content in the fuel matrix. Calculations with MCNP5 and ENDF/B-VII.0 neutron nuclear data are approximately 1.4% (9σ) greater than the benchmark model eigenvalues, which is commonly seen in Monte Carlo simulations of other TRIGA reactors. Simulations of the worth measurements are within the 2σ uncertainty for most of the benchmark experiment worth values. The complete benchmark evaluation details are available in the 2014 edition of the International Handbook of Evaluated Reactor Physics Benchmark Experiments.« less

  18. THR-TH: a high-temperature gas-cooled nuclear reactor core thermal hydraulics code

    SciTech Connect (OSTI)

    Vondy, D.R.

    1984-07-01

    The ORNL version of PEBBLE, the (RZ) pebble bed thermal hydraulics code, has been extended for application to a prismatic gas cooled reactor core. The supplemental treatment is of one-dimensional coolant flow in up to a three-dimensional core description. Power density data from a neutronics and exposure calculation are used as the basic information for the thermal hydraulics calculation of heat removal. Two-dimensional neutronics results may be expanded for a three-dimensional hydraulics calculation. The geometric description for the hydraulics problem is the same as used by the neutronics code. A two-dimensional thermal cell model is used to predict temperatures in the fuel channel. The capability is available in the local BOLD VENTURE computation system for reactor core analysis with capability to account for the effect of temperature feedback by nuclear cross section correlation. Some enhancements have also been added to the original code to add pebble bed modeling flexibility and to generate useful auxiliary results. For example, an estimate is made of the distribution of fuel temperatures based on average and extreme conditions regularly calculated at a number of locations.

  19. Performance analysis of distributed symmetric sparse matrix vector multiplication algorithm for multi-core architectures

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

    Oryspayev, Dossay; Aktulga, Hasan Metin; Sosonkina, Masha; Maris, Pieter; Vary, James P.

    2015-07-14

    In this article, sparse matrix vector multiply (SpMVM) is an important kernel that frequently arises in high performance computing applications. Due to its low arithmetic intensity, several approaches have been proposed in literature to improve its scalability and efficiency in large scale computations. In this paper, our target systems are high end multi-core architectures and we use messaging passing interface + open multiprocessing hybrid programming model for parallelism. We analyze the performance of recently proposed implementation of the distributed symmetric SpMVM, originally developed for large sparse symmetric matrices arising in ab initio nuclear structure calculations. We also study important featuresmore » of this implementation and compare with previously reported implementations that do not exploit underlying symmetry. Our SpMVM implementations leverage the hybrid paradigm to efficiently overlap expensive communications with computations. Our main comparison criterion is the "CPU core hours" metric, which is the main measure of resource usage on supercomputers. We analyze the effects of topology-aware mapping heuristic using simplified network load model. Furthermore, we have tested the different SpMVM implementations on two large clusters with 3D Torus and Dragonfly topology. Our results show that the distributed SpMVM implementation that exploits matrix symmetry and hides communication yields the best value for the "CPU core hours" metric and significantly reduces data movement overheads.« less

  20. Evaluation of Neutron Radiography Reactor LEU-Core Start-Up Measurements

    SciTech Connect (OSTI)

    Bess, John D.; Maddock, Thomas L.; Smolinski, Andrew T.; Marshall, Margaret A.

    2014-11-04

    Benchmark models were developed to evaluate the cold-critical start-up measurements performed during the fresh core reload of the Neutron Radiography (NRAD) reactor with Low Enriched Uranium (LEU) fuel. Experiments include criticality, control-rod worth measurements, shutdown margin, and excess reactivity for four core loadings with 56, 60, 62, and 64 fuel elements. The worth of four graphite reflector block assemblies and an empty dry tube used for experiment irradiations were also measured and evaluated for the 60-fuel-element core configuration. Dominant uncertainties in the experimental keff come from uncertainties in the manganese content and impurities in the stainless steel fuel cladding as well as the 236U and erbium poison content in the fuel matrix. Calculations with MCNP5 and ENDF/B-VII.0 neutron nuclear data are approximately 1.4% (9?) greater than the benchmark model eigenvalues, which is commonly seen in Monte Carlo simulations of other TRIGA reactors. Simulations of the worth measurements are within the 2? uncertainty for most of the benchmark experiment worth values. The complete benchmark evaluation details are available in the 2014 edition of the International Handbook of Evaluated Reactor Physics Benchmark Experiments.

  1. Performance analysis of distributed symmetric sparse matrix vector multiplication algorithm for multi-core architectures

    SciTech Connect (OSTI)

    Oryspayev, Dossay; Aktulga, Hasan Metin; Sosonkina, Masha; Maris, Pieter; Vary, James P.

    2015-07-14

    In this article, sparse matrix vector multiply (SpMVM) is an important kernel that frequently arises in high performance computing applications. Due to its low arithmetic intensity, several approaches have been proposed in literature to improve its scalability and efficiency in large scale computations. In this paper, our target systems are high end multi-core architectures and we use messaging passing interface + open multiprocessing hybrid programming model for parallelism. We analyze the performance of recently proposed implementation of the distributed symmetric SpMVM, originally developed for large sparse symmetric matrices arising in ab initio nuclear structure calculations. We also study important features of this implementation and compare with previously reported implementations that do not exploit underlying symmetry. Our SpMVM implementations leverage the hybrid paradigm to efficiently overlap expensive communications with computations. Our main comparison criterion is the "CPU core hours" metric, which is the main measure of resource usage on supercomputers. We analyze the effects of topology-aware mapping heuristic using simplified network load model. Furthermore, we have tested the different SpMVM implementations on two large clusters with 3D Torus and Dragonfly topology. Our results show that the distributed SpMVM implementation that exploits matrix symmetry and hides communication yields the best value for the "CPU core hours" metric and significantly reduces data movement overheads.

  2. Evaluation of Neutron Radiography Reactor LEU-Core Start-Up Measurements

    SciTech Connect (OSTI)

    Bess, John D.; Maddock, Thomas L.; Smolinski, Andrew T.; Marshall, Margaret A.

    2014-11-04

    Benchmark models were developed to evaluate the cold-critical start-up measurements performed during the fresh core reload of the Neutron Radiography (NRAD) reactor with Low Enriched Uranium (LEU) fuel. Experiments include criticality, control-rod worth measurements, shutdown margin, and excess reactivity for four core loadings with 56, 60, 62, and 64 fuel elements. The worth of four graphite reflector block assemblies and an empty dry tube used for experiment irradiations were also measured and evaluated for the 60-fuel-element core configuration. Dominant uncertainties in the experimental keff come from uncertainties in the manganese content and impurities in the stainless steel fuel cladding as well as the 236U and erbium poison content in the fuel matrix. Calculations with MCNP5 and ENDF/B-VII.0 neutron nuclear data are approximately 1.4% (9σ) greater than the benchmark model eigenvalues, which is commonly seen in Monte Carlo simulations of other TRIGA reactors. Simulations of the worth measurements are within the 2σ uncertainty for most of the benchmark experiment worth values. The complete benchmark evaluation details are available in the 2014 edition of the International Handbook of Evaluated Reactor Physics Benchmark Experiments.

  3. Thermal hydraulic method for whole core design analysis of an HTGR

    SciTech Connect (OSTI)

    Huning, A. J.; Garimella, S. [George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA (United States)

    2013-07-01

    A new thermal hydraulic method and initial results are presented for core-wide steady state analysis of prismatic High Temperature Gas-Cooled Reactors (HTGR). The method allows for the complete solution of temperature and coolant mass flow distribution by solving quasi-steady energy balances for the discretized core. Assembly blocks are discretized into unit cells for which the average temperature of each unit cell is determined. Convective heat removal is coupled to the unit cell energy balances by a 1-D axial flow model. The flow model uses established correlations for friction factor and Nusselt number. Bypass flow is explicitly calculated by using an initial guess for mass flow distribution and determining the exit pressure of each flow channel. The mass flow distribution is updated until a uniform core exit pressure condition is reached. Results are obtained for the MHTGR-350 with emphasis on the change in thermal hydraulic parameters due to various steady state power profiles and bypass gap widths. Steady state temperature distribution and its variations are discussed. (authors)

  4. Weak decay processes in pre-supernova core evolution within the gross theory

    SciTech Connect (OSTI)

    Ferreira, R. C.; Dimarco, A. J.; Samana, A. R.; Barbero, C. A.

    2014-03-20

    The beta decay and electron capture rates are of fundamental importance in the evolution of massive stars in a pre-supernova core. The beta decay process gives its contribution by emitting electrons in the plasma of the stellar core, thereby increasing pressure, which in turn increases the temperature. From the other side, the electron capture removes free electrons from the plasma of the star core contributing to the reduction of pressure and temperature. In this work we calculate the beta decay and electron capture rates in stellar conditions for 63 nuclei of relevance in the pre-supernova stage, employing Gross Theory as the nuclear model. We use the abundances calculated with the Saha equations in the hypothesis of nuclear statistical equilibrium to evaluate the time derivative of the fraction of electrons. Our results are compared with other evaluations available in the literature. They have shown to be one order less or equal than the calculated within other models. Our results indicate that these differences may influence the evolution of the star in the later stages of pre-supernova.

  5. Fabrication method for cores of structural sandwich materials including star shaped core cells

    DOE Patents [OSTI]

    Christensen, R.M.

    1997-07-15

    A method for fabricating structural sandwich materials having a core pattern which utilizes star and non-star shaped cells is disclosed. The sheets of material are bonded together or a single folded sheet is used, and bonded or welded at specific locations, into a flat configuration, and are then mechanically pulled or expanded normal to the plane of the sheets which expand to form the cells. This method can be utilized to fabricate other geometric cell arrangements than the star/non-star shaped cells. Four sheets of material (either a pair of bonded sheets or a single folded sheet) are bonded so as to define an area therebetween, which forms the star shaped cell when expanded. 3 figs.

  6. Fabrication method for cores of structural sandwich materials including star shaped core cells

    DOE Patents [OSTI]

    Christensen, Richard M.

    1997-01-01

    A method for fabricating structural sandwich materials having a core pattern which utilizes star and non-star shaped cells. The sheets of material are bonded together or a single folded sheet is used, and bonded or welded at specific locations, into a flat configuration, and are then mechanically pulled or expanded normal to the plane of the sheets which expand to form the cells. This method can be utilized to fabricate other geometric cell arrangements than the star/non-star shaped cells. Four sheets of material (either a pair of bonded sheets or a single folded sheet) are bonded so as to define an area therebetween, which forms the star shaped cell when expanded.

  7. An assessment of coupling algorithms for nuclear reactor core physics simulations

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

    Hamilton, Steven; Berrill, Mark; Clarno, Kevin; Pawlowski, Roger; Toth, Alex; Kelley, C. T.; Evans, Thomas; Philip, Bobby

    2016-04-01

    Here we evaluate the performance of multiphysics coupling algorithms applied to a light water nuclear reactor core simulation. The simulation couples the k-eigenvalue form of the neutron transport equation with heat conduction and subchannel flow equations. We compare Picard iteration (block Gauss–Seidel) to Anderson acceleration and multiple variants of preconditioned Jacobian-free Newton–Krylov (JFNK). The performance of the methods are evaluated over a range of energy group structures and core power levels. A novel physics-based approximation to a Jacobian-vector product was developed to mitigate the impact of expensive on-line cross section processing steps. Numerical simulations demonstrating the efficiency of JFNK andmore » Anderson acceleration relative to standard Picard iteration are performed on a 3D model of a nuclear fuel assembly. Finally, both criticality (k-eigenvalue) and critical boron search problems are considered.« less

  8. Core Analysis At Yellowstone Region (Sturchio, Et Al., 1990)...

    Open Energy Info (EERE)

    were 43 hydrothermal minerals (silica, clay and calcite) from Yellowstone drill cores Y-5, Y-6, Y-7, Y-8, Y-11, Y-12, and Y-13 (Fig. 1). References N. C. Sturchio, T. E. C....

  9. CONTRIBUTION OF GAMMA-RAY-LOUD RADIO GALAXIES' CORE EMISSIONS...

    Office of Scientific and Technical Information (OSTI)

    Title: CONTRIBUTION OF GAMMA-RAY-LOUD RADIO GALAXIES' CORE EMISSIONS TO THE COSMIC MeV AND GeV GAMMA-RAY BACKGROUND RADIATION The Fermi gamma-ray satellite has recently detected ...

  10. Webinar: Review Core Competencies for Appraisers to Value Green Buildings

    Broader source: Energy.gov [DOE]

    The Appraisal Foundation is developing a document to describe the fundamentals of the Valuation of Green Buildings. This document highlights the core skill sets and data necessary for appraisers to...

  11. Evidence for a Weak Iron Core at Earth's Center

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

    going from pole to pole than along the equatorial plane-why? One theory is that the grains of iron that make up most of the solid inner core could be aligned in a way that...

  12. Solid0Core Heat-Pipe Nuclear Batterly Type Reactor

    SciTech Connect (OSTI)

    Ehud Greenspan

    2008-09-30

    This project was devoted to a preliminary assessment of the feasibility of designing an Encapsulated Nuclear Heat Source (ENHS) reactor to have a solid core from which heat is removed by liquid-metal heat pipes (HP).

  13. Descriptive logs, skeletonized samples, and photographs of core...

    Open Energy Info (EERE)

    skeletonized samples, and photographs of core from Presco Energy's thermal gradient wells P3-1, P10-1, and P32-2 in the Rye Patch area, Pershing County, Nevada Jump to:...

  14. Mineral Deformation at Earth's Core-Mantle Boundary

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

    is a dynamic planet in which convection takes place on the scale of thousands of kilometers. Because Earth is mostly solid (except for its liquid-iron outer core), this...

  15. Evidence for a Weak Iron Core at Earth's Center

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

    Evidence for a Weak Iron Core at Earth's Center Print Seismic waves that pass through the center of the Earth travel faster going from pole to pole than along the equatorial...

  16. Fuel and Core Design Experiences in Cofrentes NPP

    SciTech Connect (OSTI)

    Garcia-Delgado, L.; Lopez-Carbonell, M.T.; Gomez-Bernal, I.

    2002-07-01

    The electricity market deregulation in Spain is increasing the need for innovations in nuclear power generation, which can be achieved in the fuel area by improving fuel and core designs and by introducing vendors competition. Iberdrola has developed the GIRALDA methodology for design and licensing of Cofrentes reloads, and has introduced mixed cores with fuel from different vendors. The application of GIRALDA is giving satisfactory results, and is showing its capability to adequately reproduce the core behaviour. The nuclear design team is acquiring an invaluable experience and a deep knowledge of the core, very useful to support cycle operation. Continuous improvements are expected for the future in design strategies as well as in the application of new technologies to redesign the methodology processes. (authors)

  17. Evidence for a Weak Iron Core at Earth's Center

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

    Iron Core at Earth's Center Print Seismic waves that pass through the center of the Earth travel faster going from pole to pole than along the equatorial plane-why? One theory...

  18. Core Analysis At Kilauea East Rift Geothermal Area (Quane, Et...

    Open Energy Info (EERE)

    rates lavas from Kilauea's East Rift Zone. The core analysis revealed that the average rate of lava expelled from the volcano has been remarkably constant for the last 350,000...

  19. Serially connected solid oxide fuel cells having monolithic cores

    DOE Patents [OSTI]

    Herceg, Joseph E. (Naperville, IL)

    1987-01-01

    A solid oxide fuel cell for electrochemically combining fuel and oxidant for generating galvanic output, wherein the cell core has an array of cell segments electrically serially connected in the flow direction, each segment consisting of electrolyte walls and interconnect that are substantially devoid of any composite inert materials for support. Instead, the core is monolithic, where each electrolyte wall consists of thin layers of cathode and anode materials sandwiching a thin layer of electrolyte material therebetween. Means direct the fuel to the anode-exposed core passageways and means direct the oxidant to the cathode-exposed core passageways; and means also direct the galvanic output to an exterior circuit. Each layer of the electrolyte composite materials is of the order of 0.002-0.01 cm thick; and each layer of the cathode and anode materials is of the order of 0.002-0.05 cm thick. Between 2 and 50 cell segments may be connected in series.

  20. Magnetic Vortex Core Reversal by Low-Field Excitations

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

    millitesla (mT) to reverse the direction of a vortex core. ... and their possible application to data storage technologies. ... Is there a physical limit to how far this process can go? At ...

  1. Core Holes At Valles Caldera - Sulphur Springs Geothermal Area...

    Open Energy Info (EERE)

    Dennis L. Nielson, Pisto Larry, C.W. Criswell, R. Gribble, K. Meeker, J.A. Musgrave, T. Smith, D. Wilson (1989) Scientific Core Hole Valles Caldera No. 2B (VC-2B), New Mexico:...

  2. Core Analysis At Fenton Hill HDR Geothermal Area (Brookins &...

    Open Energy Info (EERE)

    Core Analysis Activity Date - 1983 Usefulness useful DOE-funding Unknown Notes See linked abstract for a synopsis of chemical analyses and Rb-Sr age determinations for gneissic...

  3. Thermal barrier and support for nuclear reactor fuel core

    DOE Patents [OSTI]

    Betts, Jr., William S.; Pickering, J. Larry; Black, William E.

    1987-01-01

    A thermal barrier/core support for the fuel core of a nuclear reactor having a metallic cylinder secured to the reactor vessel liner and surrounded by fibrous insulation material. A top cap is secured to the upper end of the metallic cylinder that locates and orients a cover block and post seat. Under normal operating conditions, the metallic cylinder supports the entire load exerted by its associated fuel core post. Disposed within the metallic cylinder is a column of ceramic material, the height of which is less than that of the metallic cylinder, and thus is not normally load bearing. In the event of a temperature excursion beyond the design limits of the metallic cylinder and resulting in deformation of the cylinder, the ceramic column will abut the top cap to support the fuel core post.

  4. Superconducting shielded core reactor with reduced AC losses

    DOE Patents [OSTI]

    Cha, Yung S.; Hull, John R.

    2006-04-04

    A superconducting shielded core reactor (SSCR) operates as a passive device for limiting excessive AC current in a circuit operating at a high power level under a fault condition such as shorting. The SSCR includes a ferromagnetic core which may be either closed or open (with an air gap) and extends into and through a superconducting tube or superconducting rings arranged in a stacked array. First and second series connected copper coils each disposed about a portion of the iron core are connected to the circuit to be protected and are respectively wound inside and outside of the superconducting tube or rings. A large impedance is inserted into the circuit by the core when the shielding capability of the superconducting arrangement is exceeded by the applied magnetic field generated by the two coils under a fault condition to limit the AC current in the circuit. The proposed SSCR also affords reduced AC loss compared to conventional SSCRs under continuous normal operation.

  5. Hanging core support system for a nuclear reactor. [LMFBR

    DOE Patents [OSTI]

    Burelbach, J.P.; Kann, W.J.; Pan, Y.C.; Saiveau, J.G.; Seidensticker, R.W.

    1984-04-26

    For holding the reactor core in the confining reactor vessel, a support is disclosed that is structurally independent of the vessel, that is dimensionally accurate and stable, and that comprises tandem tension linkages that act redundantly of one another to maintain stabilized core support even in the unlikely event of the complete failure of one of the linkages. The core support has a mounting platform for the reactor core, and unitary structure including a flange overlying the top edge of the reactor vessels, and a skirt and box beams between the flange and platform for establishing one of the linkages. A plurality of tension rods connect between the deck closing the reactor vessel and the platform for establishing the redundant linkage. Loaded Belleville springs flexibly hold the tension rods at the deck and separable bayonet-type connections hold the tension rods at the platform.

  6. Core Holes At Valles Caldera - Redondo Geothermal Area (Goff...

    Open Energy Info (EERE)

    Caldera, New Mexico Jamie N. Gardner, Fraser E. Goff, Sue Goff, Larry Maassen, K. Mathews, Daniel Wachs, D. Wilson (1987) Core Lithology, Valles Caldera No. 1, New Mexico John...

  7. Shalf_NUG2006_QuadCore.ppt

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

    Memory Subsystem Performance and QuadCore Predictions John Shalf SDSA Team Leader jshalf@lbl.gov NERSC User Group Meeting September 17, 2007 NERSC User Group Meeting, September 17,...

  8. Dose Rate Calculations for Rotary Mode Core Sampling Exhauster

    SciTech Connect (OSTI)

    FOUST, D.J.

    2000-10-26

    This document provides the calculated estimated dose rates for three external locations on the Rotary Mode Core Sampling (RMCS) exhauster HEPA filter housing, per the request of Characterization Field Engineering.

  9. Simple, Ethanol-Driven Synthesis of Core-Shell Nanoparticles...

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

    Find More Like This Return to Search Simple, Ethanol-Driven Synthesis of Core-Shell ... This "green" synthesis method uses ethanol - a simple solvent for metal precursors "as the ...

  10. Core of First Section of New Accelerator Rolled Out | Jefferson...

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

    and rolled out for further assembly. This "string" of components will become the heart of a cryomodule, which will be added to the lab's particle accelerator in 2012. Core...

  11. Ultrafast Core-Hole Induced Dynamics in Water

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

    Ultrafast Core-Hole Induced Dynamics in Water Print A thorough understanding of the chemical processes that are initiated when radiation interacts with aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a water molecule sets off motions that can affect bonding configurations, which in turn affect subsequent chemical-reaction pathways. However, it is a fundamental

  12. Sandia National Laboratories: Research: Facilities: Annular Core Research

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

    Reactor Facility Annular Core Research Reactor facility Nuclear science photo At the Annular Core Research Reactor (ACRR) facility, Sandia researchers can subject various test objects to a mixed photon and neutron irradiation environment featuring either a very rapid pulse rate or a long-term, steady-state rate. Research and other activities The radiation produced at the ACRR is used for the following research activities: Neutron-scattering experiments Nondestructive testing, including

  13. Modifications to WRF's dynamical core to improve the treatment of

    Office of Scientific and Technical Information (OSTI)

    moisture for large--eddy simulations (Journal Article) | SciTech Connect WRF's dynamical core to improve the treatment of moisture for large--eddy simulations Citation Details In-Document Search Title: Modifications to WRF's dynamical core to improve the treatment of moisture for large--eddy simulations Yamaguchi and Feingold (2012) note that the cloud fields in their Weather Research and Forecasting (WRF) large-eddy simulations (LESs) of marine stratocumulus exhibit a strong sensitivity to

  14. Star cell type core configuration for structural sandwich materials

    DOE Patents [OSTI]

    Christensen, R.M.

    1995-08-01

    A new pattern for cellular core material used in sandwich type structural materials is disclosed. The new pattern involves star shaped cells intermixed with hexagonal shaped cells. The new patterned cellular core material includes star shaped cells interconnected at points thereof and having hexagonal shape cells positioned adjacent the star points. The new pattern allows more flexibility and can conform more easily to curved shapes. 3 figs.

  15. Controlled Release from Core-Shell Nanoporous Silica Particles for

    Office of Scientific and Technical Information (OSTI)

    Corrosion Inhibition of Aluminum Alloys (Journal Article) | SciTech Connect Journal Article: Controlled Release from Core-Shell Nanoporous Silica Particles for Corrosion Inhibition of Aluminum Alloys Citation Details In-Document Search Title: Controlled Release from Core-Shell Nanoporous Silica Particles for Corrosion Inhibition of Aluminum Alloys Cerium (Ce) corrosion inhibitors were encapsulated into hexagonally ordered nanoporous silica particles via single-step aerosol-assisted

  16. Rotary mode core sampling approved checklist: 241-TX-113

    SciTech Connect (OSTI)

    Fowler, K.D.

    1998-08-03

    The safety assessment for rotary mode core sampling was developed using certain bounding assumptions, however, those assumptions were not verified for each of the existing or potential flammable gas tanks. Therefore, a Flammable Gas/Rotary Mode Core Sampling Approved Checklist has been completed for tank 241-TX-113 prior to sampling operations. This transmittal documents the dispositions of the checklist items from the safety assessment.

  17. Rotary mode core sampling approved checklist: 241-TX-116

    SciTech Connect (OSTI)

    FOWLER, K.D.

    1999-02-24

    The safety assessment for rotary mode core sampling was developed using certain bounding assumptions, however, those assumptions were not verified for each of the existing or potential flammable gas tanks. Therefore, a Flammable Gas/Rotary Mode Core Sampling Approved Checklist has been completed for tank 241-TX-116 prior to sampling operations. This transmittal documents the dispositions of the checklist items from the safety assessment.

  18. Ultrafast Core-Hole Induced Dynamics in Water

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

    Ultrafast Core-Hole Induced Dynamics in Water Print A thorough understanding of the chemical processes that are initiated when radiation interacts with aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a water molecule sets off motions that can affect bonding configurations, which in turn affect subsequent chemical-reaction pathways. However, it is a fundamental

  19. Ultrafast Core-Hole Induced Dynamics in Water

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

    Ultrafast Core-Hole Induced Dynamics in Water Print A thorough understanding of the chemical processes that are initiated when radiation interacts with aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a water molecule sets off motions that can affect bonding configurations, which in turn affect subsequent chemical-reaction pathways. However, it is a fundamental

  20. Ultrafast Core-Hole Induced Dynamics in Water

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

    Ultrafast Core-Hole Induced Dynamics in Water Print A thorough understanding of the chemical processes that are initiated when radiation interacts with aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a water molecule sets off motions that can affect bonding configurations, which in turn affect subsequent chemical-reaction pathways. However, it is a fundamental

  1. Ultrafast Core-Hole Induced Dynamics in Water

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

    Ultrafast Core-Hole Induced Dynamics in Water Print A thorough understanding of the chemical processes that are initiated when radiation interacts with aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a water molecule sets off motions that can affect bonding configurations, which in turn affect subsequent chemical-reaction pathways. However, it is a fundamental

  2. Laboratory methods for enhanced oil recovery core floods

    SciTech Connect (OSTI)

    Robertson, E.P.; Bala, G.A.; Thomas, C.P.

    1994-03-01

    Current research at the Idaho National Engineering Laboratory (INEL) is investigating microbially enhanced oil recovery (MEOR) systems for application to oil reservoirs. Laboratory corefloods are invaluable in developing technology necessary for a field application of MEOR. Methods used to prepare sandstone cores for experimentation, coreflooding techniques, and quantification of coreflood effluent are discussed in detail. A technique to quantify the small volumes of oil associated with laboratory core floods is described.

  3. THREE-DIMENSIONAL HYDRODYNAMIC CORE-COLLAPSE SUPERNOVA SIMULATIONS FOR AN 11.2 M{sub Sun} STAR WITH SPECTRAL NEUTRINO TRANSPORT

    SciTech Connect (OSTI)

    Takiwaki, Tomoya; Kotake, Kei; Suwa, Yudai

    2012-04-20

    We present numerical results on three-dimensional (3D) hydrodynamic core-collapse simulations of an 11.2 M{sub Sun} star. By comparing one-dimensional (1D) and two-dimensional (2D) results with those of 3D, we study how the increasing spacial multi-dimensionality affects the postbounce supernova dynamics. The calculations were performed with an energy-dependent treatment of the neutrino transport that is solved by the isotropic diffusion source approximation scheme. In agreement with previous study, our 1D model does not produce explosions for the 11.2 M{sub Sun} star, while the neutrino-driven revival of the stalled bounce shock is obtained in both the 2D and 3D models. The standing accretion-shock instability (SASI) is observed in the 3D models, in which the dominant mode of the SASI is bipolar (l = 2) with its saturation amplitudes being slightly smaller than 2D. By performing a tracer-particle analysis, we show that the maximum residency time of material in the gain region becomes longer in 3D than in 2D due to non-axisymmetric flow motions, which is one of advantageous aspects of 3D models to obtain neutrino-driven explosions. Our results show that convective matter motions below the gain radius become much more violent in 3D than in 2D, making the neutrino luminosity larger for 3D. Nevertheless, the emitted neutrino energies are made smaller due to the enhanced cooling. Our results indicate whether these advantages for driving 3D explosions could or could not overwhelm the disadvantages is sensitive to the employed numerical resolutions. An encouraging finding is that the shock expansion tends to become more energetic for models with finer resolutions. To draw a robust conclusion, 3D simulations with much higher numerical resolutions and with more advanced treatment of neutrino transport and of gravity are needed, which could be practicable by utilizing forthcoming Petaflops-class supercomputers.

  4. TURBULENCE DECAY AND CLOUD CORE RELAXATION IN MOLECULAR CLOUDS

    SciTech Connect (OSTI)

    Gao, Yang; Law, Chung K.; Xu, Haitao

    2015-02-01

    The turbulent motion within molecular clouds is a key factor controlling star formation. Turbulence supports molecular cloud cores from evolving to gravitational collapse and hence sets a lower bound on the size of molecular cloud cores in which star formation can occur. On the other hand, without a continuous external energy source maintaining the turbulence, such as in molecular clouds, the turbulence decays with an energy dissipation time comparable to the dynamic timescale of clouds, which could change the size limits obtained from Jean's criterion by assuming constant turbulence intensities. Here we adopt scaling relations of physical variables in decaying turbulence to analyze its specific effects on the formation of stars. We find that the decay of turbulence provides an additional approach for Jeans' criterion to be achieved, after which gravitational infall governs the motion of the cloud core. This epoch of turbulence decay is defined as cloud core relaxation. The existence of cloud core relaxation provides a more complete understanding of the effect of the competition between turbulence and gravity on the dynamics of molecular cloud cores and star formation.

  5. Core and wing densities of asymmetric coronal spectral profiles: Implications for the mass supply of the solar corona

    SciTech Connect (OSTI)

    Patsourakos, S.; Klimchuk, J. A.; Young, P. R. E-mail: james.a.klimchuk@nasa.gov

    2014-02-01

    Recent solar spectroscopic observations have shown that coronal spectral lines can exhibit asymmetric profiles, with enhanced emissions at their blue wings. These asymmetries correspond to rapidly upflowing plasmas at speeds exceeding ?50 km s{sup 1}. Here, we perform a study of the density of the rapidly upflowing material and compare it with that of the line core that corresponds to the bulk of the plasma. For this task, we use spectroscopic observations of several active regions taken by the Extreme Ultraviolet Imaging Spectrometer of the Hinode mission. The density sensitive ratio of the Fe XIV lines at 264.78 and 274.20 is used to determine wing and core densities. We compute the ratio of the blue wing density to the core density and find that most values are of order unity. This is consistent with the predictions for coronal nanoflares if most of the observed coronal mass is supplied by chromospheric evaporation driven by the nanoflares. However, much larger blue wing-to-core density ratios are predicted if most of the coronal mass is supplied by heated material ejected with type II spicules. Our measurements do not rule out a spicule origin for the blue wing emission, but they argue against spicules being a primary source of the hot plasma in the corona. We note that only about 40% of the pixels where line blends could be safely ignored have blue wing asymmetries in both Fe XIV lines. Anticipated sub-arcsecond spatial resolution spectroscopic observations in future missions could shed more light on the origin of blue, red, and mixed asymmetries.

  6. V-052: Drupal Core Access Bypass and Arbitrary PHP Code Execution

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

    Vulnerabilities | Department of Energy 2: Drupal Core Access Bypass and Arbitrary PHP Code Execution Vulnerabilities V-052: Drupal Core Access Bypass and Arbitrary PHP Code Execution Vulnerabilities December 21, 2012 - 12:15am Addthis PROBLEM: Drupal Core Access Bypass and Arbitrary PHP Code Execution Vulnerabilities PLATFORM: Drupal 6.x versions prior to 6.27 Drupal 7.x versions prior to 7.18 ABSTRACT: Drupal Core Multiple vulnerabilities REFERENCE LINKS: SA-CORE-2012-004 - Drupal core

  7. Annular seed-blanket thorium fuel core concepts for heavy water...

    Office of Scientific and Technical Information (OSTI)

    core concepts for heavy water moderated reactors Citation Details In-Document Search Title: Annular seed-blanket thorium fuel core concepts for heavy water moderated reactors New ...

  8. Core Analysis At Lake City Hot Springs Area (Benoit Et Al., 2005...

    Open Energy Info (EERE)

    Rock core analyses and mineral assemblage investigations References Dick Benoit, Joe Moore, Colin Goranson, David Blackwell (2005) Core Hole Drilling And Testing At The Lake...

  9. Tuning g factors of core-shell nanoparticles by controlled positioning...

    Office of Scientific and Technical Information (OSTI)

    Tuning g factors of core-shell nanoparticles by controlled positioning of magnetic ... 22, 2017 Prev Next Title: Tuning g factors of core-shell nanoparticles by ...

  10. Efficiency of static core turn-off in a system-on-a-chip with variation

    DOE Patents [OSTI]

    Cher, Chen-Yong; Coteus, Paul W; Gara, Alan; Kursun, Eren; Paulsen, David P; Schuelke, Brian A; Sheets, II, John E; Tian, Shurong

    2013-10-29

    A processor-implemented method for improving efficiency of a static core turn-off in a multi-core processor with variation, the method comprising: conducting via a simulation a turn-off analysis of the multi-core processor at the multi-core processor's design stage, wherein the turn-off analysis of the multi-core processor at the multi-core processor's design stage includes a first output corresponding to a first multi-core processor core to turn off; conducting a turn-off analysis of the multi-core processor at the multi-core processor's testing stage, wherein the turn-off analysis of the multi-core processor at the multi-core processor's testing stage includes a second output corresponding to a second multi-core processor core to turn off; comparing the first output and the second output to determine if the first output is referring to the same core to turn off as the second output; outputting a third output corresponding to the first multi-core processor core if the first output and the second output are both referring to the same core to turn off.

  11. Rossi alpha Measurements and Calculations for HEU/Pb Core (Technical...

    Office of Scientific and Technical Information (OSTI)

    Rossi alpha Measurements and Calculations for HEUPb Core Citation Details In-Document Search Title: Rossi alpha Measurements and Calculations for HEUPb Core Rossi alpha ...

  12. Casting core for a cooling arrangement for a gas turbine component

    DOE Patents [OSTI]

    Lee, Ching-Pang; Heneveld, Benjamin E

    2015-01-20

    A ceramic casting core, including: a plurality of rows (162, 166, 168) of gaps (164), each gap (164) defining an airfoil shape; interstitial core material (172) that defines and separates adjacent gaps (164) in each row (162, 166, 168); and connecting core material (178) that connects adjacent rows (170, 174, 176) of interstitial core material (172). Ends of interstitial core material (172) in one row (170, 174, 176) align with ends of interstitial core material (172) in an adjacent row (170, 174, 176) to form a plurality of continuous and serpentine shaped structures each including interstitial core material (172) from at least two adjacent rows (170, 174, 176) and connecting core material (178).

  13. Rossi alpha Measurements and Calculations for HEU/Pb Core (Technical...

    Office of Scientific and Technical Information (OSTI)

    Rossi alpha Measurements and Calculations for HEUPb Core Citation Details In-Document Search Title: Rossi alpha Measurements and Calculations for HEUPb Core You are accessing ...

  14. A Two-Step Approach to Uncertainty Quantification of Core Simulators...

    Office of Scientific and Technical Information (OSTI)

    through core simulators are the XSUSA statistical approach and the "two-step" method. ... the multiplication factor and in the core power distribution was examined in the framework ...

  15. MULTI-DIMENSIONAL FEATURES OF NEUTRINO TRANSFER IN CORE-COLLAPSE SUPERNOVAE

    SciTech Connect (OSTI)

    Sumiyoshi, K. [Numazu College of Technology, Ooka 3600, Numazu, Shizuoka 410-8501 (Japan); Takiwaki, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Matsufuru, H. [Computing Research Center, High Energy Accelerator Research Organization 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Yamada, S., E-mail: sumi@numazu-ct.ac.jp, E-mail: takiwaki.tomoya@nao.ac.jp, E-mail: hideo.matsufuru@kek.jp, E-mail: shoichi@heap.phys.waseda.ac.jp [Science and Engineering and Advanced Research Institute for Science and Engineering, Waseda University, Okubo, 3-4-1, Shinjuku, Tokyo 169-8555 (Japan)

    2015-01-01

    We study the multi-dimensional properties of neutrino transfer inside supernova cores by solving the Boltzmann equations for neutrino distribution functions in genuinely six-dimensional phase space. Adopting representative snapshots of the post-bounce core from other supernova simulations in three dimensions, we solve the temporal evolution to stationary states of neutrino distribution functions using our Boltzmann solver. Taking advantage of the multi-angle and multi-energy feature realized by the S {sub n} method in our code, we reveal the genuine characteristics of spatially three-dimensional neutrino transfer, such as nonradial fluxes and nondiagonal Eddington tensors. In addition, we assess the ray-by-ray approximation, turning off the lateral-transport terms in our code. We demonstrate that the ray-by-ray approximation tends to propagate fluctuations in thermodynamical states around the neutrino sphere along each radial ray and overestimate the variations between the neutrino distributions on different radial rays. We find that the difference in the densities and fluxes of neutrinos between the ray-by-ray approximation and the full Boltzmann transport becomes ?20%, which is also the case for the local heating rate, whereas the volume-integrated heating rate in the Boltzmann transport is found to be only slightly larger (?2%) than the counterpart in the ray-by-ray approximation due to cancellation among different rays. These results suggest that we should carefully assess the possible influences of various approximations in the neutrino transfer employed in current simulations of supernova dynamics. Detailed information on the angle and energy moments of neutrino distribution functions will be profitable for the future development of numerical methods in neutrino-radiation hydrodynamics.

  16. Driven and decaying turbulence simulations of low–mass star formation: From clumps to cores to protostars

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

    Offner, Stella S. R.; Klein, Richard I.; McKee, Christopher F.

    2008-10-20

    Molecular clouds are observed to be turbulent, but the origin of this turbulence is not well understood. As a result, there are two different approaches to simulating molecular clouds, one in which the turbulence is allowed to decay after it is initialized, and one in which it is driven. We use the adaptive mesh refinement (AMR) code, Orion, to perform high-resolution simulations of molecular cloud cores and protostars in environments with both driven and decaying turbulence. We include self-gravity, use a barotropic equation of state, and represent regions exceeding the maximum grid resolution with sink particles. We analyze the propertiesmore » of bound cores such as size, shape, line width, and rotational energy, and we find reasonable agreement with observation. At high resolution the different rates of core accretion in the two cases have a significant effect on protostellar system development. Clumps forming in a decaying turbulence environment produce high-multiplicity protostellar systems with Toomre Q unstable disks that exhibit characteristics of the competitive accretion model for star formation. In contrast, cores forming in the context of continuously driven turbulence and virial equilibrium form smaller protostellar systems with fewer low-mass members. Furthermore, our simulations of driven and decaying turbulence show some statistically significant differences, particularly in the production of brown dwarfs and core rotation, but the uncertainties are large enough that we are not able to conclude whether observations favor one or the other.« less

  17. CHEMICAL AND PHYSICAL CONDITIONS IN MOLECULAR CLOUD CORE DC 000.4-19.5 (SL42) IN CORONA AUSTRALIS

    SciTech Connect (OSTI)

    Hardegree-Ullman, E.; Whittet, D. C. B.; Harju, J.; Juvela, M.; Sipilae, O.; Hotzel, S.

    2013-01-20

    Chemical reactions in starless molecular clouds are heavily dependent on interactions between gas phase material and solid phase dust and ices. We have observed the abundance and distribution of molecular gases in the cold, starless core DC 000.4-19.5 (SL42) in Corona Australis using data from the Swedish ESO Submillimeter Telescope. We present column density maps determined from measurements of C{sup 18}O (J = 2-1, 1-0) and N{sub 2}H{sup +} (J = 1-0) emission features. Herschel data of the same region allow a direct comparison to the dust component of the cloud core and provide evidence for gas phase depletion of CO at the highest extinctions. The dust color temperature in the core calculated from Herschel maps ranges from roughly 10.7 to 14.0 K. This range agrees with the previous determinations from Infrared Space Observatory and Planck observations. The column density profile of the core can be fitted with a Plummer-like density distribution approaching n(r) {approx} r {sup -2} at large distances. The core structure deviates clearly from a critical Bonnor-Ebert sphere. Instead, the core appears to be gravitationally bound and to lack thermal and turbulent support against the pressure of the surrounding low-density material: it may therefore be in the process of slow contraction. We test two chemical models and find that a steady-state depletion model agrees with the observed C{sup 18}O column density profile and the observed N(C{sup 18}O) versus A{sub V} relationship.

  18. Three dimensional core-collapse supernova simulated using a 15 M⊙ progenitor

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

    Lentz, Eric J.; Bruenn, Stephen W.; Hix, W. Raphael; Mezzacappa, Anthony; Messer, O. E. Bronson; Endeve, Eirik; Blondin, John M.; Harris, J. Austin; Marronetti, Pedro; Yakunin, Konstantin N.

    2015-07-10

    We have performed ab initio neutrino radiation hydrodynamics simulations in three and two spatial dimensions (3D and 2D) of core-collapse supernovae from the same 15 M⊙ progenitor through 440 ms after core bounce. Both 3D and 2D models achieve explosions; however, the onset of explosion (shock revival) is delayed by ~100 ms in 3D relative to the 2D counterpart and the growth of the diagnostic explosion energy is slower. This is consistent with previously reported 3D simulations utilizing iron-core progenitors with dense mantles. In the ~100 ms before the onset of explosion, diagnostics of neutrino heating and turbulent kinetic energymore » favor earlier explosion in 2D. During the delay, the angular scale of convective plumes reaching the shock surface grows and explosion in 3D is ultimately lead by a single, large-angle plume, giving the expanding shock a directional orientation not dissimilar from those imposed by axial symmetry in 2D simulations. Finally, we posit that shock revival and explosion in the 3D simulation may be delayed until sufficiently large plumes form, whereas such plumes form more rapidly in 2D, permitting earlier explosions.« less

  19. Vertically aligned P(VDF-TrFE) core-shell structures on flexible pillar arrays

    SciTech Connect (OSTI)

    Choi, Yoon-Young; Yun, Tae Gwang; Qaiser, Nadeem; Paik, Haemin; Roh, Hee Seok; Hong, Jongin; Hong, Seungbum; Han, Seung Min; No, Kwangsoo

    2015-06-04

    PVDF and P(VDF-TrFE) nano- and micro- structures are widely used due to their potential applications in several fields, including sensors, actuators, vital sign transducers, and energy harvesters. In this study, we developed vertically aligned P(VDF-TrFE) core-shell structures using high modulus polyurethane acrylate (PUA) pillars as the support structure to maintain the structural integrity. In addition, we were able to improve the piezoelectric effect by 1.85 times from 40 ± 2 to 74 ± 2 pm/V when compared to the thin film counterpart, which contributes to the more efficient current generation under a given stress, by making an effective use of the P(VDF-TrFE) thin top layer as well as the side walls. We attribute the enhancement of piezoelectric effects to the contributions from the shell component and the strain confinement effect, which was supported by our modeling results. We envision that these organic-based P(VDF-TrFE) core-shell structures will be used widely as 3D sensors and power generators because they are optimized for current generations by utilizing all surface areas, including the side walls of core-shell structures.

  20. THREE-DIMENSIONAL BOLTZMANN HYDRO CODE FOR CORE COLLAPSE IN MASSIVE STARS. I. SPECIAL RELATIVISTIC TREATMENTS

    SciTech Connect (OSTI)

    Nagakura, Hiroki [Yukawa Institute for Theoretical Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan); Sumiyoshi, Kohsuke [Numazu College of Technology, Ooka 3600, Numazu, Shizuoka 410-8501 (Japan); Yamada, Shoichi [Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan)

    2014-10-01

    We propose a novel numerical method for solving multi-dimensional, special relativistic Boltzmann equations for neutrinos coupled with hydrodynamics equations. This method is meant to be applied to simulations of core-collapse supernovae. We handle special relativity in a non-conventional way, taking account of all orders of v/c. Consistent treatment of the advection and collision terms in the Boltzmann equations has been a challenge, which we overcome by employing two different energy grids: Lagrangian remapped and laboratory fixed grids. We conduct a series of basic tests and perform a one-dimensional simulation of core-collapse, bounce, and shock-stall for a 15 M {sub ?} progenitor model with a minimum but essential set of microphysics. We demonstrate in the latter simulation that our new code is capable of handling all phases in core-collapse supernova. For comparison, a non-relativistic simulation is also conducted with the same code, and we show that they produce qualitatively wrong results in neutrino transfer. Finally, we discuss a possible incorporation of general relativistic effects into our method.

  1. The Explosion Mechanism of Core-Collapse Supernovae: Progress in Supernova Theory and Experiments

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

    Foglizzo, Thierry; Kazeroni, Rémi; Guilet, Jérôme; Masset, Frédéric; González, Matthias; Krueger, Brendan K.; Novak, Jérôme; Oertel, Micaela; Margueron, Jérôme; Faure, Julien; et al

    2015-03-17

    The explosion of core-collapse supernova depends on a sequence of events taking place in less than a second in a region of a few hundred kilometers at the center of a supergiant star, after the stellar core approaches the Chandrasekhar mass and collapses into a proto-neutron star, and before a shock wave is launched across the stellar envelope. Theoretical efforts to understand stellar death focus on the mechanism which transforms the collapse into an explosion. Progress in understanding this mechanism is reviewed with particular attention to its asymmetric character. We highlight a series of successful studies connecting observations of supernovamore » remnants and pulsars properties to the theory of core-collapse using numerical simulations. The encouraging results from first principles models in axisymmetric simulations is tempered by new puzzles in 3D. The diversity of explosion paths and the dependence on the pre-collapse stellar structure is stressed, as well as the need to gain a better understanding of hydrodynamical and MHD instabilities such as SASI and neutrino-driven convection. The shallow water analogy of shock dynamics is presented as a comparative system where buoyancy effects are absent. This dynamical system can be studied numerically and also experimentally with a water fountain. Lastly, we analyse the potential of this complementary research tool for supernova theory. We also review its potential for public outreach in science museums.« less

  2. Vertically aligned P(VDF-TrFE) core-shell structures on flexible pillar arrays

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

    Choi, Yoon-Young; Yun, Tae Gwang; Qaiser, Nadeem; Paik, Haemin; Roh, Hee Seok; Hong, Jongin; Hong, Seungbum; Han, Seung Min; No, Kwangsoo

    2015-06-04

    PVDF and P(VDF-TrFE) nano- and micro- structures are widely used due to their potential applications in several fields, including sensors, actuators, vital sign transducers, and energy harvesters. In this study, we developed vertically aligned P(VDF-TrFE) core-shell structures using high modulus polyurethane acrylate (PUA) pillars as the support structure to maintain the structural integrity. In addition, we were able to improve the piezoelectric effect by 1.85 times from 40 ± 2 to 74 ± 2 pm/V when compared to the thin film counterpart, which contributes to the more efficient current generation under a given stress, by making an effective use ofmore » the P(VDF-TrFE) thin top layer as well as the side walls. We attribute the enhancement of piezoelectric effects to the contributions from the shell component and the strain confinement effect, which was supported by our modeling results. We envision that these organic-based P(VDF-TrFE) core-shell structures will be used widely as 3D sensors and power generators because they are optimized for current generations by utilizing all surface areas, including the side walls of core-shell structures.« less

  3. POLARIZATION STRUCTURE IN THE CORE OF 1803+784: A SIGNATURE OF RECOLLIMATION SHOCKS?

    SciTech Connect (OSTI)

    Cawthorne, T. V.; Jorstad, S. G.; Marscher, A. P.

    2013-07-20

    The extragalactic radio source 1803+784 is a BL Lac object that shows rapid variability and strong linear polarization. Very long baseline interferometry observations reveal that the core possesses a distinctive structure in polarized intensity with two maxima on axis and two minima symmetrically placed on either side. The approximately radial pattern of electric field polarization rods is reminiscent of the results obtained earlier by Cawthorne for conical shocks, but, individually, these do not reproduce the main features of the polarized intensity images. In numerical simulations and experiments, these shocks occur in pairs and help to stabilize jets as they adjust to changes in environment. Here, the polarization resulting from such structures is investigated using an approximate, analytical approach, by making some simple assumptions about the nature of the flow between two such shock waves. For fairly small viewing angles, it is found that a reasonable representation of the core polarization of 1803+784 can be obtained. The similarity between the observed and model polarizations supports the view that the core structure in 1803+784 represents a recollimation shock, and that such shock waves may be responsible for the first disturbance and hence brightening of the quiescent flow in astrophysical jets.

  4. Evaluation of the Start-Up Core Physics Tests at Japan's High Temperature Engineering Test Reactor (Annular Core Loadings)

    SciTech Connect (OSTI)

    John D. Bess; Nozomu Fujimoto; James W. Sterbentz; Luka Snoj; Atsushi Zukeran

    2010-03-01

    The High Temperature Engineering Test Reactor (HTTR) of the Japan Atomic Energy Agency (JAEA) is a 30 MWth, graphite-moderated, helium-cooled reactor that was constructed with the objectives to establish and upgrade the technological basis for advanced high-temperature gas-cooled reactors (HTGRs) as well as to conduct various irradiation tests for innovative high-temperature research. The core size of the HTTR represents about one-half of that of future HTGRs, and the high excess reactivity of the HTTR, necessary for compensation of temperature, xenon, and burnup effects during power operations, is similar to that of future HTGRs. During the start-up core physics tests of the HTTR, various annular cores were formed to provide experimental data for verification of design codes for future HTGRs. The Japanese government approved construction of the HTTR in the 1989 fiscal year budget; construction began at the Oarai Research and Development Center in March 1991 and was completed May 1996. Fuel loading began July 1, 1998, from the core periphery. The first criticality was attained with an annular core on November 10, 1998 at 14:18, followed by a series of start-up core physics tests until a fully-loaded core was developed on December 16, 1998. Criticality tests were carried out into January 1999. The first full power operation with an average core outlet temperature of 850ºC was completed on December 7, 2001, and operational licensing of the HTTR was approved on March 6, 2002. The HTTR attained high temperature operation at 950 ºC in April 19, 2004. After a series of safety demonstration tests, it will be used as the heat source in a hydrogen production system by 2015. Hot zero-power critical, rise-to-power, irradiation, and safety demonstration testing , have also been performed with the HTTR, representing additional means for computational validation efforts. Power tests were performed in steps from 0 to 30 MW, with various tests performed at each step to confirm core characteristics, thermal-hydraulic properties, and radiation shielding. The high-temperature test operation at 950 ºC represented the fifth and final phase of the rise-to-power tests. The safety tests demonstrated inherent safety features of the HTTR such as slow temperature response during abnormal events due to the large heat capacity of the core and the negative reactivity feedback. The experimental benchmark performed and currently evaluated in this report pertains to the data available for the annular core criticals from the initial six isothermal, annular and fully-loaded, core critical measurements performed at the HTTR. Evaluation of the start-up core physics tests specific to the fully-loaded core is compiled elsewhere (HTTR-GCR-RESR-001).

  5. Incremental k-core decomposition: Algorithms and evaluation

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

    Sariyuce, Ahmet Erdem; Gedik, Bugra; Jacques-SIlva, Gabriela; Wu, Kun -Lung; Catalyurek, Umit V.

    2016-02-01

    A k-core of a graph is a maximal connected subgraph in which every vertex is connected to at least k vertices in the subgraph. k-core decomposition is often used in large-scale network analysis, such as community detection, protein function prediction, visualization, and solving NP-hard problems on real networks efficiently, like maximal clique finding. In many real-world applications, networks change over time. As a result, it is essential to develop efficient incremental algorithms for dynamic graph data. In this paper, we propose a suite of incremental k-core decomposition algorithms for dynamic graph data. These algorithms locate a small subgraph that ismore » guaranteed to contain the list of vertices whose maximum k-core values have changed and efficiently process this subgraph to update the k-core decomposition. We present incremental algorithms for both insertion and deletion operations, and propose auxiliary vertex state maintenance techniques that can further accelerate these operations. Our results show a significant reduction in runtime compared to non-incremental alternatives. We illustrate the efficiency of our algorithms on different types of real and synthetic graphs, at varying scales. Furthermore, for a graph of 16 million vertices, we observe relative throughputs reaching a million times, relative to the non-incremental algorithms.« less

  6. Hanging core support system for a nuclear reactor

    DOE Patents [OSTI]

    Burelbach, James P.; Kann, William J.; Pan, Yen-Cheng; Saiveau, James G.; Seidensticker, Ralph W.

    1987-01-01

    For holding the reactor core in the confining reactor vessel, a support is disclosed that is structurally independent of the vessel, that is dimensionally accurate and stable, and that comprises tandem tension linkages that act redundantly of one another to maintain stabilized core support even in the unlikely event of the complete failure of one of the linkages. The core support has a mounting platform for the reactor core, and unitary structure including a flange overlying the top edge of the reactor vessels, and a skirt and box beams between the flange and platform for establishing one of the linkages. A plurality of tension rods connect between the deck closing the reactor vessel and the platform for establishing the redundant linkage. Loaded Belleville springs flexibly hold the tension rods at the deck and separable bayonet-type connections hold the tension rods at the platform. Motion or radiation sensing detectors can be provide at the lower ends of the tension rods for obtaining pertinent readings proximate the core.

  7. Laboratory studies evaluating CO2 flood impact on the geomechanics of whole core samples

    SciTech Connect (OSTI)

    O'Connor, William K.

    2005-06-01

    Geological sequestration of CO2, whether by enhanced oil recovery (EOR), coal-bed methane (CBM) recovery, or saline aquifer injection is a promising near-term sequestration methodology. While tremendous experience exists for EOR, and CBM recovery has been demonstrated in existing fields, saline aquifer injection studies have only recently been initiated. Studies evaluating the availability of saline aquifers suitable for CO2 injection show great potential, however, the long-term fate of the injected CO2 in these ancient aqueous systems is still uncertain. Migration of the CO2 beyond the natural reservoir seals could become problematic, thus the identification of means to enhance the natural seals may help lead to the utilization of this sequestration methodology. Co-injection of a mineral reactant slurry, either with the CO2 or in separate, secondary injection wells, could provide a means to enhance the natural reservoir seals by providing the necessary cations for precipitation of mineral carbonates along the periphery of the injection plume. The subject study evaluates the merit of several mineral slurry co-injection strategies, by conduct of a series of laboratory-scale CO2 flood tests on whole core samples of the Mt. Simon sandstone from the Illinois Basin. By conducting these tests on whole core samples rather than crushed core, an evaluation of the impact of the CO2 flood on the rock mechanics properties as well as the geochemistry of the core and brine solution has been possible. This empirical data could provide a valuable resource for the validation of reservoir models under development for these engineered CO2 systems.

  8. The Effect of Accident Conditions on the Molten Core Material Relocation into the Lower Head of a PWR Vessel with Application to TMI-2

    SciTech Connect (OSTI)

    An Xuegao; Dhir, Vijay K.; Okrent, David

    2000-11-15

    The damage progression of the reactor core and the slumping mechanism of molten material to the lower head of the reactor vessel were examined through simulation of severe accident scenarios that lead to large-scale core damage. The calculations were carried out on a Three Mile Island Unit 2 configuration using the computer code SCDAP/RELAP5/MOD3.2.Different accident scenarios were simulated. The high-pressure injection and makeup flow rates were changed. The extreme case with no water being added during the accident was examined. Reflood by restart of coolant pump 2B was also studied. Finally, the size of the power-operated relief valve opening was also changed. The effects of these accident scenarios on the accident progression and the core damage process were studied.It is concluded that, according to code MOD3.2, the molten material slumped to the lower head of the reactor vessel when the junction of the top and side crusts failed after the molten pool had reached the periphery of the core. When the effective stress caused by pressure imbalance inside and outside of the crust became larger than the ultimate strength of the crust, the crust failed mechanically.

  9. TRIGGERING COLLAPSE OF THE PRESOLAR DENSE CLOUD CORE AND INJECTING SHORT-LIVED RADIOISOTOPES WITH A SHOCK WAVE. II. VARIED SHOCK WAVE AND CLOUD CORE PARAMETERS

    SciTech Connect (OSTI)

    Boss, Alan P.; Keiser, Sandra A. E-mail: keiser@dtm.ciw.edu

    2013-06-10

    A variety of stellar sources have been proposed for the origin of the short-lived radioisotopes that existed at the time of the formation of the earliest solar system solids, including Type II supernovae (SNe), asymptotic giant branch (AGB) and super-AGB stars, and Wolf-Rayet star winds. Our previous adaptive mesh hydrodynamics models with the FLASH2.5 code have shown which combinations of shock wave parameters are able to simultaneously trigger the gravitational collapse of a target dense cloud core and inject significant amounts of shock wave gas and dust, showing that thin SN shocks may be uniquely suited for the task. However, recent meteoritical studies have weakened the case for a direct SN injection to the presolar cloud, motivating us to re-examine a wider range of shock wave and cloud core parameters, including rotation, in order to better estimate the injection efficiencies for a variety of stellar sources. We find that SN shocks remain as the most promising stellar source, though planetary nebulae resulting from AGB star evolution cannot be conclusively ruled out. Wolf-Rayet (WR) star winds, however, are likely to lead to cloud core shredding, rather than to collapse. Injection efficiencies can be increased when the cloud is rotating about an axis aligned with the direction of the shock wave, by as much as a factor of {approx}10. The amount of gas and dust accreted from the post-shock wind can exceed that injected from the shock wave, with implications for the isotopic abundances expected for a SN source.

  10. Possible Methods to Estimate Core Location in a Beyond-Design-Basis Accident at a GE BWR with a Mark I Containment Stucture

    SciTech Connect (OSTI)

    Walston, S; Rowland, M; Campbell, K

    2011-07-27

    It is difficult to track to the location of a melted core in a GE BWR with Mark I containment during a beyond-design-basis accident. The Cooper Nuclear Station provided a baseline of normal material distributions and shielding configurations for the GE BWR with Mark I containment. Starting with source terms for a design-basis accident, methods and remote observation points were investigated to allow tracking of a melted core during a beyond-design-basis accident. The design of the GE BWR with Mark-I containment highlights an amazing poverty of expectations regarding a common mode failure of all reactor core cooling systems resulting in a beyond-design-basis accident from the simple loss of electric power. This design is shown in Figure 1. The station blackout accident scenario has been consistently identified as the leading contributor to calculated probabilities for core damage. While NRC-approved models and calculations provide guidance for indirect methods to assess core damage during a beyond-design-basis loss-of-coolant accident (LOCA), there appears to be no established method to track the location of the core directly should the LOCA include a degree of fuel melt. We came to the conclusion that - starting with detailed calculations which estimate the release and movement of gaseous and soluble fission products from the fuel - selected dose readings in specific rooms of the reactor building should allow the location of the core to be verified.

  11. Core coolability following loss-of-heat sink accidents. [LMFBR

    SciTech Connect (OSTI)

    Khatib-Rahbar, M.

    1983-01-01

    Most investigations of core meltdown scenarios in liquid metal fast breeder reactors (LMFBRs) have focused on accidents resulting from unprotected transients. In comparison, protected accidents which may lead to loss of core coolability and subsequent meltdown have received considerably less attention until recently. The sequence of events leading to the protected loss-of-heat sink (LOHS) accident is among other things dependent on plant type and design. The situation is vastly different in pool-type LMFBRs as compared to the loop-type design; this is as a result of major differences in the primary system configuration, coolant inventory and the structural design. The principal aim of the present paper is to address LOHS accidents in a loop-type LMFBR in regard to physical sequences of events which could lead to loss-of-core coolability and subsequent meltdown.

  12. G305.136+0.068: A MASSIVE AND DENSE COLD CORE IN AN EARLY STAGE OF EVOLUTION

    SciTech Connect (OSTI)

    Garay, Guido; Mardones, Diego; Contreras, Yanett; Servajean, Elise; Guzmán, Andrés E.; Pineda, Jaime E.

    2015-01-20

    We report molecular line observations, made with ASTE and SEST, and dust continuum observations at 0.87 mm, made with APEX, toward the cold dust core G305.136+0.068. The molecular observations show that the core is isolated and roughly circularly symmetric and imply that it has a mass of 1.1 × 10{sup 3} M {sub ☉}. A simultaneous model fitting of the spectra observed in four transitions of CS, using a non-LTE radiative transfer code, indicates that the core is centrally condensed, with the density decreasing with radius as r {sup –1.8}, and that the turbulent velocity increases toward the center. The dust observations also indicate that the core is highly centrally condensed and that the average column density is 1.1 g cm{sup –2}, a value slightly above the theoretical threshold required for the formation of high-mass stars. A fit to the spectral energy distribution of the emission from the core indicates a dust temperature of 17 ± 2 K, confirming that the core is cold. Spitzer images show that the core is seen in silhouette from 3.6 to 24.0 μm and that it is surrounded by an envelope of emission, presumably tracing an externally excited photo-dissociated region. We found two embedded sources within a region of 20'' centered at the peak of the core, one of which is young, has a luminosity of 66 L {sub ☉}, and is accreting mass with a high accretion rate of ∼1 × 10{sup –4} M {sub ☉} yr{sup –1}. We suggest that this object corresponds to the seed of a high-mass protostar still in the process of formation. The present observations support the hypothesis that G305.136+0.068 is a massive and dense cold core in an early stage of evolution, in which the formation of a high-mass star has just started.

  13. DARK MATTER HEATING AND EARLY CORE FORMATION IN DWARF GALAXIES

    SciTech Connect (OSTI)

    Madau, Piero; Shen, Sijing [Department of Astronomy and Astrophysics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); Governato, Fabio [Astronomy Department, University of Washington, Seattle, WA 98195 (United States)

    2014-07-01

    We present more results from a fully cosmological ?CDM simulation of a group of isolated dwarf galaxies that has been shown to reproduce the observed stellar mass and cold gas content, resolved star formation histories, and metallicities of dwarfs in the Local Volume. Here we investigate the energetics and timetable of the cusp-core transformation. As suggested by previous work, supernova-driven gas outflows remove dark matter (DM) cusps and create kiloparsec-size cores in all systems having a stellar mass M {sub *} > 10{sup 6} M {sub ?}. The {sup D}M core mass removal efficiency{sup }dark mass ejected per unit stellar massranges today from a few to a dozen, and increases with decreasing host mass. Because dwarfs form the bulk of their stars prior to redshift 1 and the amount of work required for DM heating and core formation scales approximately as M{sub vir}{sup 5/3}, the unbinding of the DM cusp starts early and the formation of cored profiles is not as energetically onerous as previously claimed. DM particles in the cusp typically migrate to 2-3 core radii after absorbing a few percent of the energy released by supernovae. The present-day slopes of the inner DM mass profiles, ? ? dlog M/dlog R ? 2.5-3, of the simulated ''Bashful'' and ''Doc'' dwarfs are similar to those measured in the luminous Fornax and Sculptor dwarf spheroidals. None of the simulated galaxies has a circular velocity profile exceeding 20 km s{sup 1} in the inner 1kpc, implying that supernova feedback is key to solve the ''too-big-to-fail'' problem for Milky Way subhalos.

  14. SURVIVAL OF INTERSTELLAR MOLECULES TO PRESTELLAR DENSE CORE COLLAPSE AND EARLY PHASES OF DISK FORMATION

    SciTech Connect (OSTI)

    Hincelin, U.; Wakelam, V.; Hersant, F.; Guilloteau, S.; Commerçon, B.

    2013-09-20

    An outstanding question of astrobiology is the link between the chemical composition of planets, comets, and other solar system bodies and the molecules formed in the interstellar medium. Understanding the chemical and physical evolution of the matter leading to the formation of protoplanetary disks is an important step for this. We provide some new clues to this long-standing problem using three-dimensional chemical simulations of the early phases of disk formation: we interfaced the full gas-grain chemical model Nautilus with the radiation-magnetohydrodynamic model RAMSES, for different configurations and intensities of the magnetic field. Our results show that the chemical content (gas and ices) is globally conserved during the collapsing process, from the parent molecular cloud to the young disk surrounding the first Larson core. A qualitative comparison with cometary composition suggests that comets are constituted of different phases, some molecules being direct tracers of interstellar chemistry, while others, including complex molecules, seem to have been formed in disks, where higher densities and temperatures allow for an active grain surface chemistry. The latter phase, and its connection with the formation of the first Larson core, remains to be modeled.

  15. Separative analyses of a chromatographic column packed with a core-shell adsorbent for lithium isotope separation

    SciTech Connect (OSTI)

    Sugiyama, T.; Sugura, K.; Enokida, Y.; Yamamoto, I.

    2015-03-15

    Lithium-6 is used as a blanket material for sufficient tritium production in DT fueled fusion reactors. A core-shell type adsorbent was proposed for lithium isotope separation by chromatography. The mass transfer model in a chromatographic column consisted of 4 steps, such as convection and dispersion in the column, transfer through liquid films, intra-particle diffusion and and adsorption or desorption at the local adsorption sites. A model was developed and concentration profiles and time variation in the column were numerically simulated. It became clear that core-shell type adsorbents with thin porous shell were saturated rapidly relatively to fully porous one and established a sharp edge of adsorption band. This is very important feature because lithium isotope separation requires long-distance development of adsorption band. The values of HETP (Height Equivalent of a Theoretical Plate) for core-shell adsorbent packed column were estimated by statistical moments of the step response curve. The value of HETP decreased with the thickness of the porous shell. A core-shell type adsorbent is, then, useful for lithium isotope separation. (authors)

  16. ARCADIA{sup R} - A New Generation of Coupled Neutronics / Core Thermal- Hydraulics Code System at AREVA NP

    SciTech Connect (OSTI)

    Curca-Tivig, Florin; Merk, Stephan; Pautz, Andreas; Thareau, Sebastien

    2007-07-01

    Anticipating future needs of our customers and willing to concentrate synergies and competences existing in the company for the benefit of our customers, AREVA NP decided in 2002 to develop the next generation of coupled neutronics/ core thermal-hydraulic (TH) code systems for fuel assembly and core design calculations for both, PWR and BWR applications. The global CONVERGENCE project was born: after a feasibility study of one year (2002) and a conceptual phase of another year (2003), development was started at the beginning of 2004. The present paper introduces the CONVERGENCE project, presents the main feature of the new code system ARCADIA{sup R} and concludes on customer benefits. ARCADIA{sup R} is designed to meet AREVA NP market and customers' requirements worldwide. Besides state-of-the-art physical modeling, numerical performance and industrial functionality, the ARCADIA{sup R} system is featuring state-of-the-art software engineering. The new code system will bring a series of benefits for our customers: e.g. improved accuracy for heterogeneous cores (MOX/ UOX, Gd...), better description of nuclide chains, and access to local neutronics/ thermal-hydraulics and possibly thermal-mechanical information (3D pin by pin full core modeling). ARCADIA is a registered trademark of AREVA NP. (authors)

  17. COLLAPSE AND FRAGMENTATION OF MAGNETIC MOLECULAR CLOUD CORES WITH THE ENZO AMR MHD CODE. I. UNIFORM DENSITY SPHERES

    SciTech Connect (OSTI)

    Boss, Alan P.; Keiser, Sandra A.

    2013-02-20

    Magnetic fields are important contributors to the dynamics of collapsing molecular cloud cores, and can have a major effect on whether collapse results in a single protostar or fragmentation into a binary or multiple protostar system. New models are presented of the collapse of magnetic cloud cores using the adaptive mesh refinement code Enzo2.0. The code was used to calculate the ideal magnetohydrodynamics (MHD) of initially spherical, uniform density, and rotation clouds with density perturbations, i.e., the Boss and Bodenheimer standard isothermal test case for three-dimensional (3D) hydrodynamics codes. After first verifying that Enzo reproduces the binary fragmentation expected for the non-magnetic test case, a large set of models was computed with varied initial magnetic field strengths and directions with respect to the cloud core axis of rotation (parallel or perpendicular), density perturbation amplitudes, and equations of state. Three significantly different outcomes resulted: (1) contraction without sustained collapse, forming a denser cloud core; (2) collapse to form a single protostar with significant spiral arms; and (3) collapse and fragmentation into binary or multiple protostar systems, with multiple spiral arms. Comparisons are also made with previous MHD calculations of similar clouds with a barotropic equations of state. These results for the collapse of initially uniform density spheres illustrate the central importance of both magnetic field direction and field strength for determining the outcome of dynamic protostellar collapse.

  18. Electroelastic fields in artificially created vortex cores in epitaxial

    Office of Scientific and Technical Information (OSTI)

    BiFeO3 thin films (Journal Article) | SciTech Connect Electroelastic fields in artificially created vortex cores in epitaxial BiFeO3 thin films Citation Details In-Document Search This content will become publicly available on August 4, 2016 Title: Electroelastic fields in artificially created vortex cores in epitaxial BiFeO3 thin films Authors: Winchester, B. [1] ; Balke, N. [2] ; Cheng, X. X. [1] ; Morozovska, A. N. [3] ; Kalinin, S. [2] Search SciTech Connect for author "Kalinin,

  19. On defining core properties for composite sandwich panels

    SciTech Connect (OSTI)

    DeSautel, J.M.; Sikarskie, D.L.

    1997-12-31

    In the interests of performance, fuel economy, as well as other factors, weight reduction in transportation vehicles is receiving considerable attention. It is well know that sandwich construction can provide a structural component that has both high stiffness and high strength per unit weight. In a sandwich structure a low density, low stiffness, low strength core is bonded between two high stiffness, high strength facesheets producing a structure that is particularly efficient in resisting bending loads. A key element in a sandwich construction is the core. Its` properties, particularly its` shear modulus and yield/failure stress, must be accurately known for proper structural design. Two ASTM standards exist for determining these properties; ASTM C273-88 and ASTM C393-94. The ASTM C273-88 is a simple shear test on the core material alone, while the ASTM C393-94 obtains core properties through bending data on sandwich beams. It is well known, particularly for the lower cost cores, e.g. foams, that differences in properties, sometimes appreciable, exist for these two tests. One of the main purposes of the present paper is to show that specimen geometry can have a first order effect on the material properties, i.e. only for ratios of sandwich beam length to thickness in the ASTM C393-94 test greater than 20 do the results of the two ASTM tests approach each other. A second objective of the paper is to determine the effect of the shear test plate thickness in the ASTM C273-88 test. Steel plates of thickness {1/4} inches, 5/8 inches, and 1 inch were used, i.e. bonded to the core specimens and then tested in simple shear. Only for the stiffest cores tested were any statistically different results obtained and then only minor differences for the {1/4} inches plates. Some typical test results through to core yield/failure are shown to demonstrate the different post yield behaviors.

  20. Core-Collapse Supernovae and Host Galaxy Stellar Populations (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Core-Collapse Supernovae and Host Galaxy Stellar Populations Citation Details In-Document Search Title: Core-Collapse Supernovae and Host Galaxy Stellar Populations Authors: Kelly, Patrick L. ; /KIPAC, Menlo Park /SLAC ; Kirshner, Robert P. ; /Harvard-Smithsonian Ctr. Astrophys. Publication Date: 2013-04-05 OSTI Identifier: 1074165 Report Number(s): SLAC-PUB-15213 arXiv:1110.1377 DOE Contract Number: AC02-76SF00515 Resource Type: Journal Article Resource Relation: