National Library of Energy BETA

Sample records for temp bht gradients

  1. Automate avec sortie Automates et le temps

    E-Print Network [OSTI]

    Grigoras, .Romulus

    Automate avec sortie Automates et le temps Automates et l'inni Automates avec contrôle auxiliaire Généralisations Philippe Quéinnec 3 janvier 2011 1 / 26 #12;Automate avec sortie Automates et le temps Automates et l'inni Automates avec contrôle auxiliaire Plan 1 Automate avec sortie 2 Automates et le temps 3

  2. Use of emission spectroscopy for real-time assessment of relative wall erosion rate of BHT-200 hall thruster for various regimes of operation

    E-Print Network [OSTI]

    Celik, Murat Alp

    Radiation emission due to Boron atoms sputtered from the Boron-Nitride ceramic walls of a BHT-200 Hall thruster was measured as

  3. Gravitational solitons, hairy black holes and phase transitions in BHT massive gravity

    E-Print Network [OSTI]

    Alfredo Perez; David Tempo; Ricardo Troncoso

    2011-06-23

    Hairy black holes and gravitational solitons in three dimensions for the new massive gravity theory proposed by Bergshoeff, Hohm and Townsend (BHT) are considered at the special case when there is a unique maximally symmetric solution. Following the Brown-York approach with suitable counterterms, it is shown that the soliton possesses a fixed negative mass which coincides with the one of AdS spacetime regardless the value of the integration constant that describes it. Hence, the soliton can be naturally regarded as a degenerate ground state labeled by a single modulus parameter. The Euclidean action, endowed with suitable counterterms, is shown to be finite and independent of modulus and hair parameters for both classes of solutions, and in the case of hairy black holes the free energy in the semiclassical approximation is reproduced. Modular invariance allows to show that the gravitational hair turns out to be determined by the modulus parameter. According to Cardy's formula, it is shown that the semiclassical entropy agrees with the microscopic counting of states provided the modulus parameter of the ground state is spontaneously fixed, which suggests that the hairy black hole is in a broken phase of the theory. Indeed, it is found that there is a critical temperature characterizing a first order phase transition between the static hairy black hole and the soliton which, due to the existence of gravitational hair, can take place in the semiclassical regime.

  4. track 1: Low Temp | geothermal 2015 peer review | Department...

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

    emp3.1CriticalMaterialswithSorbentStructuresAddleman.pdf Track1LowTemp3.2RareEarthMetalsTusaar.pdf Track1LowTemp3.3MicroorganismstoExtractMineralsCAF.pdf...

  5. Tempe Transportation Division: LNG Turbine Hybrid Electric Buses

    SciTech Connect (OSTI)

    Not Available

    2002-02-01

    Fact sheet describes the performance of liquefied natural gas (LNG) turbine hybrid electric buses used in Tempe's Transportation Division.

  6. Three-dimensional black holes, gravitational solitons, kinks and wormholes for BHT massive gravity

    E-Print Network [OSTI]

    Julio Oliva; David Tempo; Ricardo Troncoso

    2009-07-03

    The theory of massive gravity in three dimensions recently proposed by Bergshoeff, Hohm and Townsend (BHT) is considered. At the special case when the theory admits a unique maximally symmetric solution, a conformally flat space that contains black holes and gravitational solitons for any value of the cosmological constant is found. For negative cosmological constant, the black hole is characterized in terms of the mass and the "gravitational hair" parameter, providing a lower bound for the mass. For negative mass parameter, the black hole acquires an inner horizon, and the entropy vanishes at the extremal case. Gravitational solitons and kinks, being regular everywhere, are obtained from a double Wick rotation of the black hole. A wormhole solution in vacuum that interpolates between two static universes of negative spatial curvature is obtained as a limiting case of the gravitational soliton with a suitable identification. The black hole and the gravitational soliton fit within a set of relaxed asymptotically AdS conditions as compared with the ones of Brown and Henneaux. In the case of positive cosmological constant the black hole possesses an event and a cosmological horizon, whose mass is bounded from above. Remarkably, the temperatures of the event and the cosmological horizons coincide, and at the extremal case one obtains the analogue of the Nariai solution, $dS_{2}\\times S^{1}$. A gravitational soliton is also obtained through a double Wick rotation of the black hole. The Euclidean continuation of these solutions describes instantons with vanishing Euclidean action. For vanishing cosmological constant the black hole and the gravitational soliton are asymptotically locally flat spacetimes. The rotating solutions can be obtained by boosting the previous ones in the $t-\\phi$ plane.

  7. Tempe, Arizona: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page| Open Energy Information Serbia-EnhancingEt Al., 2013) | Open Energy Information DixieGeothermalTelioTelventTempe,

  8. Property:GeofluidTemp | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to: navigation,Property EditMimeTypeGeofluidTemp Jump to: navigation, search

  9. ARM: Microwave Radiometer data (MWR Profiles - QME), water vapor, temp, cloud liquid water, precip water retrievals

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

    Maria Cadeddu

    2004-02-19

    Microwave Radiometer data (MWR Profiles - QME), water vapor, temp, cloud liquid water, precip water retrievals

  10. ARM: Microwave Radiometer data (MWR Profiles - QME), water vapor, temp, cloud liquid water, precip water retrievals

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

    Maria Cadeddu

    Microwave Radiometer data (MWR Profiles - QME), water vapor, temp, cloud liquid water, precip water retrievals

  11. LES TIC, TECHNOLOGIES DE GESTION DU TEMPS ET DE LA DISTANCE

    E-Print Network [OSTI]

    van Tiggelen, Bart

    LES TIC, TECHNOLOGIES DE GESTION DU TEMPS ET DE LA DISTANCE Gérard Valenduc Professeur UNamur et la problématique "impacts sociétaux des TIC" 2 · Le rapport au temps et la gestion du temps 3 · Le centres d'intérêt "TIC et ..." L'emploi (dès les années 1980) Inquiétude concernant le processus de

  12. Paradigmes objets et synchrones dans les systmes temps-rel

    E-Print Network [OSTI]

    André, Charles

    les objets synchrones de F. Boulanger et les machines d'exécution pour langages synchrones. Les SyncParadigmes objets et synchrones dans les systèmes temps-réel Charles ANDR� Laboratoire I3S'équipe SPORTS (Synchronous Programming Of Real-Time Systems) s'intéresse à la conception de systèmes réactifs

  13. Property:USGSMeanReservoirTemp | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource HistoryPotentialRuralUtilityScalePVGeneration Jump to:SpatialResolution JumpTypes ofUSGSMeanReservoirTemp

  14. Property:SanyalTempWellhead | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EA EIS Report Url Jump to:ProgrammableYear Jump to:SanyalTempWellhead Jump

  15. Property:AvgGeoFluidTemp | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsourceII JumpQuarterly SmartDB-2,Information PromotingPropertyAvgGeoFluidTemp Jump

  16. Property:FirstWellTemp | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to: navigation,Property EditMimeType Jump to:FirstWellLog Jump to:FirstWellTemp

  17. Low-Temp Success Stories | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE: Alternative Fuelsof EnergyApril 2014 | InternationalLandLiquefiedof EnergyLow-CostLow-Temp

  18. ESPACE, TEMPS ET COGNITION A PARTIR DES MATHEMATIQUES ET DES SCIENCES DE LA NATURE

    E-Print Network [OSTI]

    Longo, Giuseppe

    1 ESPACE, TEMPS ET COGNITION A PARTIR DES MATHEMATIQUES ET DES SCIENCES DE LA NATURE Francis BAILLY et Giuseppe LONGO RESUME : La cognition humaine paraît étroitement liée à la structure de l'espace et pertinence pour la cognition elle-même. MOTS-CLES : espace, temps, cognition, théories scientifiques

  19. La complexit du temps et la simplicit de l'action protensive du vivant Giuseppe Longo

    E-Print Network [OSTI]

    Longo, Giuseppe

    'un vécu qui permet de construire une géodésique relative à l'espace de l'action. Mais le temps du vivant

  20. SAGEO'2007, pages 00 00 Service Web de constitution en temps rel

    E-Print Network [OSTI]

    SAGEO'2007, pages 00 à 00 Service Web de constitution en temps réel de mini-cubes SOLAP pour solution, basée sur les architectures orientées services et les technologies des services Web, pour adapter architectures and Web services technologies, designed to adapt SOLAP data cubes to the requirements

  1. REGULATION POLITIQUE ET REGULATION D'USAGE DANS LE TEMPS DE TRAVAIL1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 REGULATION POLITIQUE ET REGULATION D'USAGE DANS LE TEMPS DE TRAVAIL1 : par G. de Terssac, J REGULATION AND REGULATION OF USE OVER WORKING TIME In this paper we discuss « social regulations » as defined by Reynaud (1999). These regulations, in our case (working)-time regulations, are multiple. Their combination

  2. 4.5 Rock Coatings RI Dorn, Arizona State University, Tempe, AZ, USA

    E-Print Network [OSTI]

    Dorn, Ron

    4.5 Rock Coatings RI Dorn, Arizona State University, Tempe, AZ, USA r 2013 Elsevier Inc. All rights reserved. 4.5.1 Introduction to Rock Coatings 70 4.5.2 Interpreting Rock Coatings through a Landscape: Subaerial Exposure of Subsurface Coatings 73 4.5.2.3 Third-Order Control: Competition from Lithobionts 78 4

  3. 4.4 Nanoscale: Mineral Weathering Boundary RI Dorn, Arizona State University, Tempe, AZ, USA

    E-Print Network [OSTI]

    Dorn, Ron

    4.4 Nanoscale: Mineral Weathering Boundary RI Dorn, Arizona State University, Tempe, AZ, USA SJ-scattered detector. Biotic weathering Mineral weathering caused by life, including bacteria, fungi, algae, plants of elements such as silica or iron. Etching of minerals Mineral dissolution is not an even produce; areas

  4. Balloon-borne sounding system (BBSS): Vaisala-processed winds, press., temp, and RH

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

    Coulter, Richard; Ritsche, Michael

    Balloon-borne sounding system (BBSS): Vaisala-processed winds, press., temp, and RH. The balloon-borne sounding system (SONDE) provides in situ measurements (vertical profiles) of both the thermodynamic state of the atmosphere, and the wind speed and direction.

  5. Partial SOP for Tube Anneal Furnace, EML: 9/04 Instructions for temp controller for Anneal furnace

    E-Print Network [OSTI]

    Reif, Rafael

    Partial SOP for Tube Anneal Furnace, EML: 9/04 Instructions for temp controller for Anneal furnace the boat into the center of the furnace and replace the quartz and ceramic end caps, carefully aligning

  6. Impact de la configuration de KVM sur les temps de rponse (exemple simple)

    E-Print Network [OSTI]

    Menichi, Luc

    second : OS : Fedora 9 64 bits Kernel : 2.6.26 KVM : kvm-75 Les VM Les VM créées sont : une Fedora 9 32 bits une Fedora 9 64 bits une CentOS 5 64 bits Ces VM sont recopiées sur les 2 hosts et lancées,68 23,92 83,76 Les temps de réponses sont mesurés sur une VM Fedora 9 32 bits, une VM Fedora 9 64 bits

  7. File:TempCampApplicationWorksheet 2011.pdf | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View New Pages RecentTempCampApplicationWorksheet 2011.pdf Jump to: navigation, search File File

  8. Property:Building/MeanAnnualTempCalculationPeriod | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History ViewMayo, Maryland:NPIProtectio1975)EnergyFloorAreaOffices JumpMeanAnnualTempCalculationPeriod Jump

  9. track 1: Low Temp | geothermal 2015 peer review | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematics And Statistics » USAJobsMotion to Withdraw | DepartmentSuite 600, 1901THE6,test test1: Low Temp |

  10. AcuTemp Expands as Appliances Become More Energy Efficient | Department of

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE: Alternative FuelsofProgram:Y-12 Beta-3AUDIT REPORT:FederalEconomic Dialogue |Energy AcuTemp

  11. Hot Pot Contoured Temperature Gradient Map

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

    Lane, Michael

    2013-06-28

    Temperature gradient contours derived from Oski temperature gradient hole program and from earlier published information.

  12. Hot Pot Contoured Temperature Gradient Map

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

    Lane, Michael

    Temperature gradient contours derived from Oski temperature gradient hole program and from earlier published information.

  13. Motivation Smoothing Projected gradient Proximal Gradient Non-Smooth Optimization

    E-Print Network [OSTI]

    Marlin, Benjamin

    Motivation Smoothing Projected gradient Proximal Gradient Non-Smooth Optimization Jason Hartford (with slides from Mark Schmidt) October 2015 #12;Motivation Smoothing Projected gradient Proximal-dimensional problems Nesterov-style and Newton-like methods allow better performance. #12;Motivation Smoothing

  14. TRANSPORT NUMBER GRADIENTS AND SOLID ELECTROLYTE DEGRADATION

    E-Print Network [OSTI]

    De Jonghe, Lutgard C.

    2014-01-01

    NUMBER GRADIENTS AND SOLID ELECTROLYTE DEGRADATION LutgardNUMBER GRADIENTS AND SOLID ELECTROLYTE DEGRADATION LutgardNUMBER GRADIENTS AND SOLID ELECTROLYTE DEGRADATION Lutgard

  15. TRANSPORT NUMBER GRADIENTS AND SOLID ELECTROLYTE DEGRADATION

    E-Print Network [OSTI]

    De Jonghe, Lutgard C.

    2012-01-01

    NUMBER GRADIENTS AND SOLID ELECTROLYTE DEGRADATION LutgardNUMBER GRADIENTS AND SOLID ELECTROLYTE DEGRADATION LutgardNUMBER GRADIENTS AND SOLID ELECTROLYTE DEGRADATION Lutgard

  16. J Low Temp Phys (2008) 151: 684689 DOI 10.1007/s10909-008-9728-3

    E-Print Network [OSTI]

    Golwala, Sunil

    2008-01-01

    whose output power is coupled to MKIDs via in-line color-defining bandpass filters. A prototype software · Submillimeter and millimeter wave detectors PACS 95.55.Jz · 85.25.Pb J. Schlaerth ( ) · J. Glenn Center Jet Propulsion Laboratory, 4800 Oak Grove Drive, M/S: 169-506, Pasadena, CA 91109, USA #12;J Low Temp

  17. ITALY DAILY, WEDNESDAY, JULY 25, 2001 PAGE 3 temp min c/f max c/f

    E-Print Network [OSTI]

    Frischer, Bernard

    Hunting for Horace's Humble Home Did the Poet Live as Modestly as He Said He Did? An Archaeological TeamDISCOVER ITALY DAILY, WEDNESDAY, JULY 25, 2001 PAGE 3 Weather temp min c/f max c/f SUNNY PARTLY in his writing than many of his contemporaries, he left clues as to where he made his home. He wrote

  18. The energy transfer in the TEMP-4M pulsed ion beam accelerator

    SciTech Connect (OSTI)

    Isakova, Y. I.; Pushkarev, A. I.; Khaylov, I. P.

    2013-07-15

    The results of a study of the energy transfer in the TEMP-4M pulsed ion beam accelerator are presented. The energy transfer efficiency in the Blumlein and a self-magnetically insulated ion diode was analyzed. Optimization of the design of the accelerator allows for 85% of energy transferred from Blumlein to the diode (including after-pulses), which indicates that the energy loss in Blumlein and spark gaps is insignificant and not exceeds 10%–12%. Most losses occur in the diode. The efficiency of energy supplied to the diode to the energy of accelerated ions is 8%–9% for a planar strip self-magnetic MID, 12%–15% for focusing diode and 20% for a spiral self-magnetic MID.

  19. Steamboat-Springs:Internet:Internet Applications:Outlook Express 4.5 Folder:Outlook Express Temp:final-masanori.doc 1

    E-Print Network [OSTI]

    Fischer, Gerhard

    Steamboat-Springs:Internet:Internet Applications:Outlook Express 4.5 Folder:Outlook Express Temp for Collaborative, Evolutionary Design____________11 #12;Steamboat-Springs:Internet:Internet Applications

  20. J Low Temp Phys (2015) 179:914 DOI 10.1007/s10909-014-1240-3

    E-Print Network [OSTI]

    Majós, Antonio Badía

    2015-01-01

    J Low Temp Phys (2015) 179:9­14 DOI 10.1007/s10909-014-1240-3 In Plane Vortex Dynamic Anisotropy with the direction in which the dissipation due to vortex movement is minimum, evidencing the existence of pinning with a platelet shape (typical dimensions: 0.7mm2 × 0.02mm) and others as tubes (3.6 × 10-3 mm2 × 0.2mm). Figure 1

  1. Gradient zone boundary control in salt gradient solar ponds

    DOE Patents [OSTI]

    Hull, John R. (Downers Grove, IL)

    1984-01-01

    A method and apparatus for suppressing zone boundary migration in a salt gradient solar pond includes extending perforated membranes across the pond at the boundaries, between the convective and non-convective zones, the perforations being small enough in size to prevent individual turbulence disturbances from penetrating the hole, but being large enough to allow easy molecular diffusion of salt thereby preventing the formation of convective zones in the gradient layer. The total area of the perforations is a sizable fraction of the membrane area to allow sufficient salt diffusion while preventing turbulent entrainment into the gradient zone.

  2. High field gradient particle accelerator

    DOE Patents [OSTI]

    Nation, John A. (Ithaca, NY); Greenwald, Shlomo (Haifa, IL)

    1989-01-01

    A high electric field gradient electron accelerator utilizing short duration, microwave radiation, and capable of operating at high field gradients for high energy physics applications or at reduced electric field gradients for high average current intermediate energy accelerator applications. Particles are accelerated in a smooth bore, periodic undulating waveguide, wherein the period is so selected that the particles slip an integral number of cycles of the r.f. wave every period of the structure. This phase step of the particles produces substantially continuous acceleration in a traveling wave without transverse magnetic or other guide means for the particle.

  3. Gradient characterization in magnetic resonance imaging

    E-Print Network [OSTI]

    Cheng, Joseph Yitan

    2007-01-01

    Special magnetic resonance (MR) scans, such as spiral imaging and echo-planar imaging, require speed and gradient accuracy while putting high demands on the MR gradient system that may cause gradient distortion. Additionally, ...

  4. Gas Exchange, Partial Pressure Gradients,

    E-Print Network [OSTI]

    Riba Sagarra, Jaume

    Gas Exchange, Partial Pressure Gradients, and the Oxygen Window Johnny E. Brian, Jr., M. Inherent unsaturation. Partial pressure vacancy. Most divers with an interest in decompression diving have affect the precise gas exchange occurring in individual areas of the lungs and body tissues. To make

  5. In Proceedings of the International Conference on Modeling and Analysis of Semiconductor Manufacturing, Arizona State University, Tempe, AZ, USA, May, 2000.

    E-Print Network [OSTI]

    Manufacturing, Arizona State University, Tempe, AZ, USA, May, 2000. HIGH-FIDELITY RAPID PROTOTYPING OF THE REAL manufacturing in- dustry has been driven by continuous technological advancement of the underlying production results in Dis- crete Event Systems theory. Furthermore, in addition to the development of the formal

  6. An Introduction to the Conjugate Gradient Method

    E-Print Network [OSTI]

    the convergence of the Jacobi Method, Steepest Descent, and Conjugate Gradients. Other topics includeAn Introduction to the Conjugate Gradient Method Without the Agonizing Pain Jonathan Richard 15213 Abstract The Conjugate Gradient Method is the most prominent iterative method for solving sparse

  7. Time changes in gradient and observed winds 

    E-Print Network [OSTI]

    Carlson, Ronald Dale

    1972-01-01

    OF FIGURES. 1. INXRODUCTION. 2. BACKGROUND AND STATEI'U':NT OF THE PROBLEM. . a. Previous studies. b. Statement of the problem. c. Objectives. 3. THEORETICAL CONSIDERATIONS. a. Gradient wind equation. b. Time rate-of-change of the gradient wind. . 4... for curvature of the height contours on the upper-level synoptic charts. Of the forces and accelerations contained in the complete horizontal equations of motion, those which do not appear in the gradient wind approximation are the frictional force...

  8. Optimization of synchronization in gradient clustered networks

    E-Print Network [OSTI]

    Xingang Wang; Liang Huang; Ying-Cheng Lai; Choy Heng Lai

    2007-11-23

    We consider complex clustered networks with a gradient structure, where sizes of the clusters are distributed unevenly. Such networks describe more closely actual networks in biophysical systems and in technological applications than previous models. Theoretical analysis predicts that the network synchronizability can be optimized by the strength of the gradient field but only when the gradient field points from large to small clusters. A remarkable finding is that, if the gradient field is sufficiently strong, synchronizability of the network is mainly determined by the properties of the subnetworks in the two largest clusters. These results are verified by numerical eigenvalue analysis and by direct simulation of synchronization dynamics on coupled-oscillator networks.

  9. C:\\DOCUME~1\\MARYEL~1\\LOCALS~1\\Temp\\Outside Access to the Sun Network.doc Outside Access to the Sun Network

    E-Print Network [OSTI]

    Califf, Mary Elaine

    C:\\DOCUME~1\\MARYEL~1\\LOCALS~1\\Temp\\Outside Access to the Sun Network.doc Outside Access to the Sun_of_host> Congratulations, you are now logged into a host on the Sun network. NOTE: sadok should only be used when\\Outside Access to the Sun Network.doc Note: The SUN workstations have been updated over Christmas break and new

  10. Approximate error conjugation gradient minimization methods

    DOE Patents [OSTI]

    Kallman, Jeffrey S

    2013-05-21

    In one embodiment, a method includes selecting a subset of rays from a set of all rays to use in an error calculation for a constrained conjugate gradient minimization problem, calculating an approximate error using the subset of rays, and calculating a minimum in a conjugate gradient direction based on the approximate error. In another embodiment, a system includes a processor for executing logic, logic for selecting a subset of rays from a set of all rays to use in an error calculation for a constrained conjugate gradient minimization problem, logic for calculating an approximate error using the subset of rays, and logic for calculating a minimum in a conjugate gradient direction based on the approximate error. In other embodiments, computer program products, methods, and systems are described capable of using approximate error in constrained conjugate gradient minimization problems.

  11. Measurement of thermodynamics using gradient flow

    E-Print Network [OSTI]

    Masakiyo Kitazawa; Masayuki Asakawa; Tetsuo Hatsuda; Takumi Iritani; Etsuko Itou; Hiroshi Suzuki

    2014-12-15

    We analyze bulk thermodynamics and correlation functions of the energy-momentum tensor in pure Yang-Mills gauge theory using the energy-momentum tensor defined by the gradient flow and small flow time expansion. Our results on thermodynamic observables are consistent with those obtained by the conventional integral method. The analysis of the correlation function of total energy supports the energy conservation. It is also addressed that these analyses with gradient flow require less statistics compared with the previous methods. All these results suggest that the energy-momentum tensor can be successfully defined and observed on the lattice with moderate numerical costs with the gradient flow.

  12. The gradient flow in simple field theories

    E-Print Network [OSTI]

    Monahan, Christopher

    2015-01-01

    The gradient flow is a valuable tool for the lattice community, with applications from scale-setting to implementing chiral fermions. Here I focus on the gradient flow as a means to suppress power-divergent mixing. Power-divergent mixing stems from the hypercubic symmetry of the lattice regulator and is a particular difficulty for calculations of, for example, high moments of parton distribution functions. The gradient flow removes power-divergent mixing on the lattice, provided the flow time is kept fixed in physical units, at the expense of introducing a new physical scale in the continuum. One approach to dealing with this new scale is the smeared operator product expansion, a formalism that systematically connects nonperturbative calculations of flowed operators to continuum physics. I study the role of the gradient flow in suppressing power-divergent mixing and present the first nonperturbative study in scalar field theory.

  13. The gradient flow in simple field theories

    E-Print Network [OSTI]

    Christopher Monahan

    2015-12-01

    The gradient flow is a valuable tool for the lattice community, with applications from scale-setting to implementing chiral fermions. Here I focus on the gradient flow as a means to suppress power-divergent mixing. Power-divergent mixing stems from the hypercubic symmetry of the lattice regulator and is a particular difficulty for calculations of, for example, high moments of parton distribution functions. The gradient flow removes power-divergent mixing on the lattice, provided the flow time is kept fixed in physical units, at the expense of introducing a new physical scale in the continuum. One approach to dealing with this new scale is the smeared operator product expansion, a formalism that systematically connects nonperturbative calculations of flowed operators to continuum physics. I study the role of the gradient flow in suppressing power-divergent mixing and present the first nonperturbative study in scalar field theory.

  14. Thermal Gradient Holes At North Brawley Geothermal Area (Matlick...

    Open Energy Info (EERE)

    gradient wells and Grace Geothermal Corporation drilled 13. Unocal's wells were 76 m deep and Grace Geothermal's were 152 m deep. The thermal gradient wells revealed an anomaly...

  15. Thermal Gradient Holes At Northern Basin & Range Region (Pritchett...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Northern Basin & Range Region (Pritchett, 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes...

  16. Scale-up characteristics of salinity gradient power technologies

    E-Print Network [OSTI]

    Feinberg, Benjamin Jacob

    2014-01-01

    gradient power,” Energy and Environmental Science, 4 (2011)gradient power,” Energy and Environmental Science, 4 (2011)to reverse osmosis, Energy & Environmental Science, 3 (2010)

  17. Thermal Gradient Holes At Blue Mountain Geothermal Area (Fairbank...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Blue Mountain Geothermal Area (Fairbank & Ross, 1999) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient...

  18. Thermal Gradient Holes At Central Nevada Seismic Zone Region...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Central Nevada Seismic Zone Region (Pritchett, 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient...

  19. Critical gradient formula for toroidal electron temperature gradient modes F. Jenko, W. Dorland,a)

    E-Print Network [OSTI]

    Hammett, Greg

    Critical gradient formula for toroidal electron temperature gradient modes F. Jenko, W. Dorland and edge plasmas are presented. An algebraic formula for the threshold of the linear instability is derived formula. We discuss the results with respect to previous analytical results and to experimental

  20. GEOTHERMAL GRADIENT DATA FOR UTAH Robert E. Blackett

    E-Print Network [OSTI]

    Laughlin, Robert B.

    of a geothermal system at depth. Temperature logs of boreholes are made by lowering a sensitive thermistor probeGEOTHERMAL GRADIENT DATA FOR UTAH by Robert E. Blackett February 2004 UTAH GEOLOGICAL SURVEY-gradient boreholes in Utah showing relative gradient magnitudes. PLATE Plate 1. Thermal-gradient boreholes in Utah

  1. Gradients of meteorological parameters in convective and nonconvective areas 

    E-Print Network [OSTI]

    McCown, Milton Samuel

    1976-01-01

    involve horizontal gradients. For example, the equations of motion relate wind speed to pressure gradient, and the thermal wind equation relates vertical wind shear to the horizontal temperature gradient. The study of gradients may help... GRADIENTS OF METEOROLOGICAL PARAMETERS IN CONVECTIVE AND NONCONVECTIVE AREAS A Thesis by Milton Samuel McCown Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER...

  2. High pressure liquid chromatographic gradient mixer

    DOE Patents [OSTI]

    Daughton, Christian G. (San Pablo, CA); Sakaji, Richard H. (El Cerrito, CA)

    1985-01-01

    A gradient mixer which effects the continuous mixing of any two miscible solvents without excessive decay or dispersion of the resultant isocratic effluent or of a linear or exponential gradient. The two solvents are fed under low or high pressure by means of two high performance liquid chromatographic pumps. The mixer comprises a series of ultra-low dead volume stainless steel tubes and low dead volume chambers. The two solvent streams impinge head-on at high fluxes. This initial nonhomogeneous mixture is then passed through a chamber packed with spirally-wound wires which cause turbulent mixing thereby homogenizing the mixture with minimum "band-broadening".

  3. High-pressure liquid chromatographic gradient mixer

    DOE Patents [OSTI]

    Daughton, C.G.; Sakaji, R.H.

    1982-09-08

    A gradient mixer effects the continuous mixing of any two miscible solvents without excessive decay or dispersion of the resultant isocratic effluent or of a linear or exponential gradient. The two solvents are fed under low or high pressure by means of two high performance liquid chromatographic pumps. The mixer comprises a series of ultra-low dead volume stainless steel tubes and low dead volume chambers. The two solvent streams impinge head-on at high fluxes. This initial nonhomogeneous mixture is then passed through a chamber packed with spirally-wound wires which cause turbulent mixing thereby homogenizing the mixture with minimum band-broadening.

  4. Short wavelength ion temperature gradient turbulence

    SciTech Connect (OSTI)

    Chowdhury, J.; Ganesh, R. [Institute for Plasma Research, Bhat, Gandhinagar (India); Brunner, S.; Lapillonne, X.; Villard, L. [CRPP, Association EURATOM-Confederation Suisse, EPFL, 1015 Lausanne (Switzerland); Jenko, F. [Max-Planck-Institut fuer Plasmaphysik Boltzmannstr. 2, D-85748 Garching (Germany)

    2012-10-15

    The ion temperature gradient (ITG) mode in the high wavenumber regime (k{sub y}{rho}{sub s}>1), referred to as short wavelength ion temperature gradient mode (SWITG) is studied using the nonlinear gyrokinetic electromagnetic code GENE. It is shown that, although the SWITG mode may be linearly more unstable than the standard long wavelength (k{sub y}{rho}{sub s}<1) ITG mode, nonlinearly its contribution to the total thermal ion heat transport is found to be low. We interpret this as resulting from an increased zonal flow shearing effect on the SWITG mode suppression.

  5. 17 GHz High Gradient Accelerator Research

    SciTech Connect (OSTI)

    Temkin, Richard J.; Shapiro, Michael A.

    2013-07-10

    This is a report on the MIT High Gradient Accelerator Research program which has included: Operation of the 17 GHz, 25 MeV MIT/Haimson Research Corp. electron accelerator at MIT, the highest frequency, stand-alone accelerator in the world; collaboration with members of the US High Gradient Collaboration, including the design and test of novel structures at SLAC at 11.4 GHz; the design, construction and testing of photonic bandgap structures, including metallic and dielectric structures; the investigation of the wakefields in novel structures; and the training of the next generation of graduate students and postdoctoral associates in accelerator physics.

  6. Universal Microfluidic Gradient Generator Daniel Irimia1

    E-Print Network [OSTI]

    Geba, Dan-Andrei

    Universal Microfluidic Gradient Generator Daniel Irimia1 , Dan A Geba2 , Mehmet Toner1 1 Bio, Building 114, 16th St, Charlestown, MA 02129. Email: mtoner@hms.harvard.edu Keywords: microfluidics cells in vitro. While microfluidic devices have shown unmatched capability in generating linear stable

  7. Ant Colony Optimization and Stochastic Gradient Descent

    E-Print Network [OSTI]

    Libre de Bruxelles, Université

    process is biased toward the generation of approximate solutions of improving quality. The historic rst (ACO) for an important logistic problem [R. Palm, personal communication]. As a consequence, the ACO show that some ACO algorithms approximate gradient descent of the expected value of the solution p

  8. Joining of Tungsten Armor Using Functional Gradients

    SciTech Connect (OSTI)

    John Scott O'Dell

    2006-12-31

    The joining of low thermal expansion armor materials such as tungsten to high thermal expansion heat sink materials has been a major problem in plasma facing component (PFC) development. Conventional planar bonding techniques have been unable to withstand the high thermal induced stresses resulting from fabrication and high heat flux testing. During this investigation, innovative functional gradient joints produced using vacuum plasma spray forming techniques have been developed for joining tungsten armor to copper alloy heat sinks. A model was developed to select the optimum gradient architecture. Based on the modeling effort, a 2mm copper rich gradient was selected. Vacuum plasma pray parameters and procedures were then developed to produce the functional gradient joint. Using these techniques, dual cooling channel, medium scale mockups (32mm wide x 400mm length) were produced with vacuum plasma spray formed tungsten armor. The thickness of the tungsten armor was up to 5mm thick. No evidence of debonding at the interface between the heat sink and the vacuum plasma sprayed material was observed.

  9. Multi-gradient drilling method and system

    DOE Patents [OSTI]

    Maurer, William C. (Houston, TX); Medley, Jr., George H. (Spring, TX); McDonald, William J. (Houston, TX)

    2003-01-01

    A multi-gradient system for drilling a well bore from a surface location into a seabed includes an injector for injecting buoyant substantially incompressible articles into a column of drilling fluid associated with the well bore. Preferably, the substantially incompressible articles comprises hollow substantially spherical bodies.

  10. Gradient zone-boundary control in salt-gradient solar ponds

    DOE Patents [OSTI]

    Hull, J.R.

    1982-09-29

    A method and apparatus for suppressing zone boundary migration in a salt gradient solar pond includes extending perforated membranes across the pond at the boundaries, between the convective and non-convective zones, the perforations being small enough in size to prevent individual turbulence disturbances from penetrating the hole, but being large enough to allow easy molecular diffusion of salt thereby preventing the formation of convective zones in the gradient layer. The total area of the perforations is a sizeable fraction of the membrane area to allow sufficient salt diffusion while preventing turbulent entrainment into the gradient zone.

  11. Automated apparatus for producing gradient gels

    DOE Patents [OSTI]

    Anderson, N.L.

    1983-11-10

    Apparatus for producing a gradient gel which serves as a standard medium for a two-dimensional analysis of proteins, the gel having a density gradient along its height formed by a variation in gel composition, with the apparatus including first and second pumping means each including a plurality of pumps on a common shaft and driven by a stepping motor capable of providing small incremental changes in pump outputs for the gel ingredients, the motors being controlled, by digital signals from a digital computer, a hollow form or cassette for receiving the gel composition, means for transferring the gel composition including a filler tube extending near the bottom of the cassette, adjustable horizontal and vertical arms for automatically removing and relocating the filler tube in the next cassette, and a digital computer programmed to automatically control the stepping motors, arm movements, and associated sensing operations involving the filling operation.

  12. High gradient accelerators for linear light sources

    SciTech Connect (OSTI)

    Barletta, W.A.

    1988-09-26

    Ultra-high gradient radio frequency linacs powered by relativistic klystrons appear to be able to provide compact sources of radiation at XUV and soft x-ray wavelengths with a duration of 1 picosecond or less. This paper provides a tutorial review of the physics applicable to scaling the present experience of the accelerator community to the regime applicable to compact linear light sources. 22 refs., 11 figs., 21 tabs.

  13. Steep Gradient Flume | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page| Open Energy Information Serbia-Enhancing CapacityVectren) Jumpand MaintenanceStationary PowerformStecaSteep Gradient

  14. ESTIMATION OF IN-SITU THERMAL CONDUCTIVITIES FROM TEMPERATURE GRADIENT MEASUREMENTS

    E-Print Network [OSTI]

    Hoang, V.T.

    2010-01-01

    to Evaluate Regional Geothermal Gradients t " Journal ofin wells, a linear geothermal gradient profile has beenfluid saturations. The geothermal gradient is caused by the

  15. Polyakov loop renormalization with gradient flow

    E-Print Network [OSTI]

    Peter Petreczky; Hans-Peter Schadler

    2015-11-14

    We propose to use the gradient flow for the renormalization of Polyakov loops in various representations. We study Polyakov loops in 2+1 flavor QCD using the HISQ action and lattices with temporal extents $N_\\tau$=6, 8, 10 and 12 in various representations, including fundamental, sextet, adjoint, decuplet, 15-plet and 27-plet. This alternative renormalization procedure allows for the renormalization over a large temperature range from $T$=100 MeV - 800 MeV, with small errors not only for the fundamental, but also for the higher representations of the Polyakov loop. We discuss the results of this procedure and Casimir scaling of the Polyakov loop.

  16. Pumpernickel Valley Geothermal Project Thermal Gradient Wells

    SciTech Connect (OSTI)

    Z. Adam Szybinski

    2006-01-01

    The Pumpernickel Valley geothermal project area is located near the eastern edge of the Sonoma Range and is positioned within the structurally complex Winnemucca fold and thrust belt of north-central Nevada. A series of approximately north-northeast-striking faults related to the Basin and Range tectonics are superimposed on the earlier structures within the project area, and are responsible for the final overall geometry and distribution of the pre-existing structural features on the property. Two of these faults, the Pumpernickel Valley fault and Edna Mountain fault, are range-bounding and display numerous characteristics typical of strike-slip fault systems. These characteristics, when combined with geophysical data from Shore (2005), indicate the presence of a pull-apart basin, formed within the releasing bend of the Pumpernickel Valley – Edna Mountain fault system. A substantial body of evidence exists, in the form of available geothermal, geological and geophysical information, to suggest that the property and the pull-apart basin host a structurally controlled, extensive geothermal field. The most evident manifestations of the geothermal activity in the valley are two areas with hot springs, seepages, and wet ground/vegetation anomalies near the Pumpernickel Valley fault, which indicate that the fault focuses the fluid up-flow. There has not been any geothermal production from the Pumpernickel Valley area, but it was the focus of a limited exploration effort by Magma Power Company. In 1974, the company drilled one exploration/temperature gradient borehole east of the Pumpernickel Valley fault and recorded a thermal gradient of 160oC/km. The 1982 temperature data from five unrelated mineral exploration holes to the north of the Magma well indicated geothermal gradients in a range from 66 to 249oC/km for wells west of the fault, and ~283oC/km in a well next to the fault. In 2005, Nevada Geothermal Power Company drilled four geothermal gradient wells, PVTG-1, -2, -3, and -4, and all four encountered geothermal fluids. The holes provided valuable water geochemistry, supporting the geothermometry results obtained from the hot springs and Magma well. The temperature data gathered from all the wells clearly indicates the presence of a major plume of thermal water centered on the Pumpernickel Valley fault, and suggests that the main plume is controlled, at least in part, by flow from this fault system. The temperature data also defines the geothermal resource with gradients >100oC/km, which covers an area a minimum of 8 km2. Structural blocks, down dropped with respect to the Pumpernickel Valley fault, may define an immediate reservoir. The geothermal system almost certainly continues beyond the recently drilled holes and might be open to the east and south, whereas the heat source responsible for the temperatures associated with this plume has not been intersected and must be at a depth greater than 920 meters (depth of the deepest well – Magma well). The geological and structural setting and other characteristics of the Pumpernickel Valley geothermal project area are markedly similar to the portions of the nearby Dixie Valley geothermal field. These similarities include, among others, the numerous, unexposed en echelon faults and large-scale pull-apart structure, which in Dixie Valley may host part of the geothermal field. The Pumpernickel Valley project area, for the majority of which Nevada Geothermal Power Company has geothermal rights, represents a geothermal site with a potential for the discovery of a relatively high temperature reservoir suitable for electric power production. Among locations not previously identified as having high geothermal potential, Pumpernickel Valley has been ranked as one of four sites with the highest potential for electrical power production in Nevada (Shevenell and Garside, 2003). Richards and Blackwell (2002) estimated the total heat loss and the preliminary production capacity for the entire Pumpernickel Valley geothermal system to be at 35MW. A more conservative estimate, for

  17. Thermoacoustic mixture separation with an axial temperature gradient

    SciTech Connect (OSTI)

    Geller, Drew W; Swift, Gregory A

    2008-01-01

    The theory of thermoacoustic mixture separation is extended to include the effect of a nonzero axial temperature gradient. The analysis yields a new term in the second-order mole flux that is proportional to the temperature gradient and to the square of the volumetric velocity and is independent of the phasing of the wave. Because of this new term, thermoacoustic separation stops at a critical temperature gradient and changes direction above that gradient. For a traveling wave, this gradient is somewhat higher than that predicted by a simple four-step model. An experiment tests the theory for temperature gradients from 0 to 416 K/m in 50-50 He-Ar mixtures.

  18. Molecular Rotation and Polarization under Thermal Gradients

    E-Print Network [OSTI]

    Alpha A Lee

    2015-10-21

    Recent molecular dynamics simulations show that a thermal gradient induces an electric field in water that is comparable to that seen in ionic thin films and biomembranes. This counterintuitive phenomena of thermo-orientation is also observed more generally in simulations of polar and non-polar size-assymetric dumbbell fluids. However, a microscopic theory for this novel non-equilibrium phenomenon is yet unknown. We develop a microscopic theory of thermo-orientation using a mean-field, local equilibrium approach. Our theory reveals analytically how thermo-orientation depends on the molecular volume, size anisotropy, and dipole moment. Predictions of the theory agree quantitatively with molecular dynamics simulations. Crucially, our framework shows how thermo-orientation can be controlled and maximised by tuning microscopic molecular properties.

  19. Molecular Rotation and Polarization under Thermal Gradients

    E-Print Network [OSTI]

    Lee, Alpha A

    2015-01-01

    Recent molecular dynamics simulations show that a thermal gradient induces an electric field in water that is comparable to that seen in ionic thin films and biomembranes. This counterintuitive phenomena of thermo-orientation is also observed more generally in simulations of polar and non-polar size-assymetric dumbbell fluids. However, a microscopic theory for this novel non-equilibrium phenomenon is yet unknown. We develop a microscopic theory of thermo-orientation using a mean-field, local equilibrium approach. Our theory reveals analytically how thermo-orientation depends on the molecular volume, size anisotropy, and dipole moment. Predictions of the theory agree quantitatively with molecular dynamics simulations. Crucially, our framework shows how thermo-orientation can be controlled and maximised by tuning microscopic molecular properties.

  20. Constant field gradient planar coupled cavity structure

    DOE Patents [OSTI]

    Kang, Y.W.; Kustom, R.L.

    1999-07-27

    A cavity structure is disclosed having at least two opposing planar housing members spaced apart to accommodate the passage of a particle beam through the structure between the members. Each of the housing members have a plurality of serially aligned hollows defined therein, and also passages, formed in the members, which interconnect serially adjacent hollows to provide communication between the hollows. The opposing planar housing members are spaced and aligned such that the hollows in one member cooperate with corresponding hollows in the other member to form a plurality of resonant cavities aligned along the particle beam within the cavity structure. To facilitate the obtaining of a constant field gradient within the cavity structure, the passages are configured so as to be incrementally narrower in the direction of travel of the particle beam. In addition, the spacing distance between the opposing housing members is configured to be incrementally smaller in the direction of travel of the beam. 16 figs.

  1. High gradient lens for charged particle beam

    SciTech Connect (OSTI)

    Chen, Yu-Jiuan

    2014-04-29

    Methods and devices enable shaping of a charged particle beam. A dynamically adjustable electric lens includes a series of alternating a series of alternating layers of insulators and conductors with a hollow center. The series of alternating layers when stacked together form a high gradient insulator (HGI) tube to allow propagation of the charged particle beam through the hollow center of the HGI tube. A plurality of transmission lines are connected to a plurality of sections of the HGI tube, and one or more voltage sources are provided to supply an adjustable voltage value to each transmission line of the plurality of transmission lines. By changing the voltage values supplied to each section of the HGI tube, any desired electric field can be established across the HGI tube. This way various functionalities including focusing, defocusing, acceleration, deceleration, intensity modulation and others can be effectuated on a time varying basis.

  2. Thermal Gradient Holes At Breitenbush Hot Springs Area (Ingebritsen...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Breitenbush Hot Springs Area (Ingebritsen, Et Al., 1993) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal...

  3. Thermal Gradient Holes At Neal Hot Springs Geothermal Area (U...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Neal Hot Springs Geothermal Area (U.S. Geothermal Inc., 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal...

  4. Thermal Gradient Holes At Lightning Dock Geothermal Area (Cunniff...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Lightning Dock Geothermal Area (Cunniff & Bowers, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal...

  5. Thermal Gradient Holes At Long Valley Caldera Geothermal Area...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Long Valley Caldera Geothermal Area (Sorey, Et Al., 1978) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal...

  6. Thermal Gradient Holes At North Brawley Geothermal Area (Edmunds...

    Open Energy Info (EERE)

    of the North Brawley, Heber, East Mesa, and Salton Sea Geothermal Areas. Notes Well logs, thermal gradient data, and magnetic data were correlated to form a better geologic...

  7. Gradient induced liquid motion on laser structured black Si surfaces

    E-Print Network [OSTI]

    Paradisanos, I; Anastasiadis, S H; Stratakis, E

    2015-01-01

    This letter reports on the femtosecond laser fabrication of gradient-wettability micro/nano- patterns on Si surfaces. The dynamics of directional droplet spreading on the surface tension gradients developed is systematically investigated and discussed. It is shown that microdroplets on the patterned surfaces spread at a maximum speed of 505 mm/sec, that is the highest velocity demonstrated so far for liquid spreading on a surface tension gradient in ambient conditions. The application of the proposed laser patterning technique for the precise fabrication of surface tension gradients for open microfluidic systems, liquid management in fuel cells and drug delivery is envisaged.

  8. Thermal Gradient Holes At Long Valley Caldera Geothermal Area...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Long Valley Caldera Geothermal Area (Conservation, 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal...

  9. Thermal Gradient Holes At Long Valley Caldera Geothermal Area...

    Open Energy Info (EERE)

    Area (Farrar, Et Al., 2003) Exploration Activity Details Location Long Valley Caldera Geothermal Area Exploration Technique Thermal Gradient Holes Activity Date 1998 - 2002...

  10. Thermal Gradient Holes At Waunita Hot Springs Geothermal Area...

    Open Energy Info (EERE)

    regional heat flux around the hot springs and potentially identify the location of the geothermal reservoir feeding the hot springs Notes Eight thermal gradient boreholes were...

  11. Generalized Defect Energy in a Gradient Plasticity Framework

    E-Print Network [OSTI]

    Bayerschen, E

    2015-01-01

    A gradient plasticity model is presented that includes a generalized, power-law type defect energy depending on the gradient of an equivalent plastic strain. Numerical regularization for the case of vanishing gradients is employed in the finite element discretization of the theory. Three exemplary choices of the defect energy exponent are compared in finite element simulations of elastic-plastic tricrystals under tensile loading. The influence of the power-law exponent is discussed related to the distribution of gradients and in regard to size effects. In addition, an analytical solution is presented for the single slip case and allows to interpret the numerical findings.

  12. Geology and Temperature Gradient Surveys Blue Mountain Geothermal...

    Open Energy Info (EERE)

    Geology and Temperature Gradient Surveys Blue Mountain Geothermal Discovery, Humboldt County, Nevada Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal...

  13. Permafrost and organic layer interactions over a climate gradient...

    Office of Scientific and Technical Information (OSTI)

    in permafrost occurrence (PF) and organic layer thickness (OLT) in more than 3000 soil pedons across a mean annual temperature (MAT) gradient. Cause and effect relationships...

  14. A Nonmonotone Approach without Differentiability Test for Gradient ...

    E-Print Network [OSTI]

    Elias S. Helou

    2015-03-18

    Mar 18, 2015 ... A Nonmonotone Approach without Differentiability Test for Gradient Sampling Methods. Elias S. Helou(elias ***at*** icmc.usp.br) Sandra A.

  15. Thermal Gradient Holes At Blue Mountain Geothermal Area (Fairbank...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Blue Mountain Geothermal Area (Fairbank & Niggemann, 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal...

  16. Thermal Gradient Holes At Walker-Lane Transitional Zone Region...

    Open Energy Info (EERE)

    Zone Region (Pritchett, 2004) Exploration Activity Details Location Walker-Lane Transition Zone Geothermal Region Exploration Technique Thermal Gradient Holes Activity Date...

  17. Engineering chemoattractant gradients using controlled release polysaccharide microspheres

    E-Print Network [OSTI]

    Wang, Yana, Ph. D. Massachusetts Institute of Technology

    2012-01-01

    Chemoattractant gradients play important roles in the normal function of immune system, from lymphocyte homeostasis to mounting efficient immune responses against infection. Improved fundamental knowledge about the role ...

  18. Thermal Gradient Holes At Upper Hot Creek Ranch Area (Benoit...

    Open Energy Info (EERE)

    gradient holes up to 500' deep were initially planned but higher than anticipated drilling and permitting costs within a fixed budget reduced the number of holes to five....

  19. Hebbian Learning and Gradient Descent Learning Neural Computation : Lecture 5

    E-Print Network [OSTI]

    Bullinaria, John

    Hebbian Learning and Gradient Descent Learning Neural Computation : Lecture 5 © John A. Bullinaria, 2014 1. Hebbian Learning 2. Learning by Error Minimisation 3. Gradient Descent Learning 4. Deriving or persistently takes part in firing it, some growth process or metabolic change takes place on one or both cells

  20. Dynamics of the Dorsal morphogen gradient Jitendra S. Kanodiaa

    E-Print Network [OSTI]

    Shvartsman, Stanislav "Stas"

    Dynamics of the Dorsal morphogen gradient Jitendra S. Kanodiaa , Richa Rikhyb , Yoosik Kima Road, Princeton, NJ 08544; bCell Biology and Metabolism Branch, NIH, Building 32, 18 Library Drive localization gradient of Dorsal (Dl), a protein related to the mammalian NF- B transcription factors. Current

  1. Enhancing Optical Gradient Forces with Metamaterials Vincent Ginis,1

    E-Print Network [OSTI]

    Enhancing Optical Gradient Forces with Metamaterials Vincent Ginis,1 Philippe Tassin,2,* Costas M demonstrate how the optical gradient force between two waveguides can be enhanced using transformation optics perceived by light, resulting in a more than tenfold enhancement of the optical force. This process

  2. Evaluation of liquid lift approach to dual gradient 

    E-Print Network [OSTI]

    Okafor, Ugochukwu Nnamdi

    2009-05-15

    .............................................. 5 2.3 Methods of Achieving Dual Gradient Drilling ...................... 9 2.3.1 Subsea Mudlift Drilling............................................... 10 2.3.2 Hollow Glass Spheres... ................................................... 9 2.5 Schematic diagram of a modified subsea mudlift system .......................... 11 2.6 Hollow glass-spheres dual gradient drilling system................................... 13 2.7 A typical offshore drilling rig modified...

  3. Generalized Hooke's law for isotropic second gradient materials

    E-Print Network [OSTI]

    F. dell'Isola; G. Sciarra; S. Vidoli

    2010-08-17

    In the spirit of Germain the most general objective stored elastic energy for a second gradient material is deduced using a literature result of Fortun\\'e & Vall\\'ee. Linear isotropic constitutive relations for stress and hyperstress in terms of strain and strain-gradient are then obtained proving that these materials are characterized by seven elastic moduli and generalizing previous studies by Toupin, Mindlin and Sokolowski. Using a suitable decomposition of the strain-gradient, it is found a necessary and sufficient condition, to be verified by the elastic moduli, assuring positive definiteness of the stored elastic energy. The problem of warping in linear torsion of a prismatic second gradient cylinder is formulated, thus obtaining a possible measurement procedure for one of the second gradient elastic moduli.

  4. Gradient Flow Analysis on MILC HISQ Ensembles

    E-Print Network [OSTI]

    A. Bazavov; C. Bernard; N. Brown; C. DeTar; J. Foley; Steven Gottlieb; U. M. Heller; J. E. Hetrick; J. Komijani; J. Laiho; L. Levkova; M. Oktay; R. L. Sugar; D. Toussaint; R. S. Van de Water; R. Zhou

    2014-11-14

    We report on a preliminary scale determination with gradient-flow techniques on the $N_f = 2 + 1 + 1$ HISQ ensembles generated by the MILC collaboration. The ensembles include four lattice spacings, ranging from 0.15 to 0.06 fm, and both physical and unphysical values of the quark masses. The scales $\\sqrt{t_0}/a$ and $w_0/a$ are computed using Symanzik flow and the cloverleaf definition of $\\langle E \\rangle$ on each ensemble. Then both scales and the meson masses $aM_\\pi$ and $aM_K$ are adjusted for mistunings in the charm mass. Using a combination of continuum chiral perturbation theory and a Taylor series ansatz in the lattice spacing, the results are simultaneously extrapolated to the continuum and interpolated to physical quark masses. Our preliminary results are $\\sqrt{t_0} = 0.1422(7)$fm and $w_0 = 0.1732(10)$fm. We also find the continuum mass-dependence of $w_0$.

  5. Efficient and robust gradient enhanced Kriging emulators.

    SciTech Connect (OSTI)

    Dalbey, Keith R.

    2013-08-01

    %E2%80%9CNaive%E2%80%9D or straight-forward Kriging implementations can often perform poorly in practice. The relevant features of the robustly accurate and efficient Kriging and Gradient Enhanced Kriging (GEK) implementations in the DAKOTA software package are detailed herein. The principal contribution is a novel, effective, and efficient approach to handle ill-conditioning of GEK's %E2%80%9Ccorrelation%E2%80%9D matrix, RN%CC%83, based on a pivoted Cholesky factorization of Kriging's (not GEK's) correlation matrix, R, which is a small sub-matrix within GEK's RN%CC%83 matrix. The approach discards sample points/equations that contribute the least %E2%80%9Cnew%E2%80%9D information to RN%CC%83. Since these points contain the least new information, they are the ones which when discarded are both the easiest to predict and provide maximum improvement of RN%CC%83's conditioning. Prior to this work, handling ill-conditioned correlation matrices was a major, perhaps the principal, unsolved challenge necessary for robust and efficient GEK emulators. Numerical results demonstrate that GEK predictions can be significantly more accurate when GEK is allowed to discard points by the presented method. Numerical results also indicate that GEK can be used to break the curse of dimensionality by exploiting inexpensive derivatives (such as those provided by automatic differentiation or adjoint techniques), smoothness in the response being modeled, and adaptive sampling. Development of a suitable adaptive sampling algorithm was beyond the scope of this work; instead adaptive sampling was approximated by omitting the cost of samples discarded by the presented pivoted Cholesky approach.

  6. Accuracy of direct gradient sensing by single cells

    E-Print Network [OSTI]

    Robert G. Endres; Ned S. Wingreen

    2009-06-15

    Many types of cells are able to accurately sense shallow gradients of chemicals across their diameters, allowing the cells to move towards or away from chemical sources. This chemotactic ability relies on the remarkable capacity of cells to infer gradients from particles randomly arriving at cell-surface receptors by diffusion. Whereas the physical limits of concentration sensing by cells have been explored, there is no theory for the physical limits of gradient sensing. Here, we derive such a theory, using as models a perfectly absorbing sphere and a perfectly monitoring sphere, which, respectively, infer gradients from the absorbed surface particle density or the positions of freely diffusing particles inside a spherical volume. We find that the perfectly absorbing sphere is superior to the perfectly monitoring sphere, both for concentration and gradient sensing, since previously observed particles are never remeasured. The superiority of the absorbing sphere helps explain the presence at the surfaces of cells of signal degrading enzymes, such as PDE for cAMP in Dictyostelium discoideum (Dicty) and BAR1 for mating factor alpha in Saccharomyces cerevisiae (budding yeast). Quantitatively, our theory compares favorably to recent measurements of Dicty moving up a cAMP gradient, suggesting these cells operate near the physical limits of gradient detection.

  7. Intrinsic Bioprobes, Inc. (Tempe, AZ)

    DOE Patents [OSTI]

    Nelson, Randall W. (Phoenix, AZ); Williams, Peter (Phoenix, AZ); Krone, Jennifer Reeve (Granbury, TX)

    2008-07-15

    Rapid mass spectrometric immunoassay methods for detecting and/or quantifying antibody and antigen analytes utilizing affinity capture to isolate the analytes and internal reference species (for quantification) followed by mass spectrometric analysis of the isolated analyte/internal reference species. Quantification is obtained by normalizing and calibrating obtained mass spectrum against the mass spectrum obtained for an antibody/antigen of known concentration.

  8. AveCryostatTemp.key

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O O DBiomass andAtomsVehicles and Fuels Site Map Printable#$

  9. Linear domain interactome and biological function of anterior gradient

    E-Print Network [OSTI]

    Lawrence, Melanie Laura Alexandra

    2013-11-29

    The Anterior Gradient 2 (AGR2) protein has been implicated in a variety of biological systems linked to cancer and metastasis, tamoxifen-induced drug resistance, pro-inflammatory diseases like IBD and asthma, and limb ...

  10. Osteochondral Interface Tissue Engineering using Macroscopic Gradients of Physicochemical Signals

    E-Print Network [OSTI]

    Dormer, Nathan Henry

    2011-04-25

    . When used in a smaller defect site, such as the New Zealand White rabbit mandibular condyle, the bioactive scaffolds were beneficial in regenerating thicker layers of cartilage. Moreover, this thesis has bridged the gradient-based microsphere scaffold...

  11. Colour Gradients in the Optical and Near-IR

    E-Print Network [OSTI]

    Roelof S. de Jong

    1995-09-01

    For many years broadband colours have been used to obtain insight into the contents of galaxies, in particular to estimate stellar and dust content. Broadband colours are easy to obtain for large samples of objects, making them ideal for statistical studies. In this paper I use the radial distribution of the colours in galaxies, which gives more insight into the local processes driving the global colour differences than integrated colours. Almost all galaxies in my sample of 86 face-on galaxies become systematically bluer with increasing radius. The radial photometry is compared to new dust extinction models and stellar population synthesis models. This comparison shows that the colour gradients in face-on galaxies are best explained by age and metallicity gradients in the stellar populations and that dust reddening plays a minor role. The colour gradients imply $M/L$ gradients, making the `missing light' problem as derived from rotation curve fitting even worse.

  12. Modelling Flow through Porous Media under Large Pressure Gradients 

    E-Print Network [OSTI]

    Srinivasan, Shriram

    2013-11-01

    The most interesting and technologically important problems in the study of flow through porous media involve very high pressures and pressure gradients in the flow do- main such as enhanced oil recovery and carbon dioxide ...

  13. Variational constitutive updates for strain gradient isotropic plasticity

    E-Print Network [OSTI]

    Qiao, Lei, Ph. D. Massachusetts Institute of Technology

    2009-01-01

    In the past decades, various strain gradient isotropic plasticity theories have been developed to describe the size-dependence plastic deformation mechanisms observed experimentally in micron-indentation, torsion, bending ...

  14. A Nonlinear Conjugate Gradient Algorithm with An Optimal Property ...

    E-Print Network [OSTI]

    2011-06-15

    State Key Laboratory of Scientific and Engineering Computing, ..... To establish a basic property for the family of conjugate gradient methods (1.3), (2.11) and ...... of Engineering Economic Systems, Stanford University, Stanford, Calif., 1972. 23

  15. Optical gradient force nano-imaging and -spectroscopy

    E-Print Network [OSTI]

    Yang, Honghua U

    2015-01-01

    Nanoscale forces play an important role in different scanning probe microscopies, most notably atomic force microscopy (AFM). In contrast, in scanning near-field optical microscopy (SNOM) a light-induced coupled local optical polarization between tip and sample is typically detected by scattering to the far field. Measurements of the optical gradient force associated with that optical near-field excitation would offer a novel optical scanning probe modality. Here we provide a generalized theory of optical gradient force nano-imaging and -spectroscopy. We quantify magnitude and distance dependence of the optical gradient force and its spectral response. We show that the optical gradient force is dispersive for single particle electronic and vibrational resonances, distinct from recent claims of its experimental observation. In contrast, the force can be absorptive for collective resonances. We provide a guidance for its measurements and distinction from competing processes such as thermal expansion.

  16. Spatial gradient of protein phosphorylation underlies replicative bacterium

    E-Print Network [OSTI]

    Chen, Y. Erin

    Spatial asymmetry is crucial to development. One mechanism for generating asymmetry involves the localized synthesis of a key regulatory protein that diffuses away from its source, forming a spatial gradient. Although ...

  17. A parametric study of thermomechanical behavior of functionally gradient materials 

    E-Print Network [OSTI]

    Chin, Che-Doong

    1996-01-01

    The dynamic thermoelastic response of functionally gradient cylinders and plates is studied. Thermomechanical coupling is significant in these materials when they are used in high temperature applications, and hence, the coupling is included...

  18. Function of the anterior gradient protein family in cancer 

    E-Print Network [OSTI]

    Fourtouna, Argyro

    2009-01-01

    Proteomic technologies verified Anterior Gradient 2, AGR-2, as a protein over-expressed in human cancers, including breast, prostate and oesophagus cancers, with the ability to inhibit the tumour suppressor protein p53. AGR-2 gene is a hormone...

  19. Field Investigations And Temperature-Gradient Drilling At Marine...

    Open Energy Info (EERE)

    Field Investigations And Temperature-Gradient Drilling At Marine Corps Air-Ground Combat Center (Mcagcc), Twenty-Nine Palms, Ca Jump to: navigation, search OpenEI Reference...

  20. Edge Temperature Gradient as Intrinsic Rotation Drive in AlcatorC...

    Office of Scientific and Technical Information (OSTI)

    Edge Temperature Gradient as Intrinsic Rotation Drive in AlcatorC-Mod Tokamak Plasmas Citation Details In-Document Search Title: Edge Temperature Gradient as Intrinsic Rotation...

  1. Thermal Gradient Holes At Salt Wells Area (Bureau of Land Management...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Salt Wells Area (Bureau of Land Management, 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient...

  2. Abundance gradients in low surface brightness spirals: clues on the origin of common gradients in galactic discs

    E-Print Network [OSTI]

    Bresolin, Fabio

    2015-01-01

    We acquired spectra of 141 HII regions in ten late-type low surface brightness galaxies (LSBGs). The analysis of the chemical abundances obtained from the nebular emission lines shows that metallicity gradients are a common feature of LSBGs, contrary to previous claims concerning the absence of such gradients in this class of galaxies. The average slope, when expressed in units of the isophotal radius, is found to be significantly shallower in comparison to galaxies of high surface brightness. This result can be attributed to the reduced surface brightness range measured across their discs, when combined with a universal surface mass density-metallicity relation. With a similar argument we explain the common abundance gradient observed in high surface brightness galaxy (HSBG) discs and its approximate dispersion. This conclusion is reinforced by our result that LSBGs share the same common abundance gradient with HSBGs, when the slope is expressed in terms of the exponential disc scale length.

  3. Environmental regulation of carbon isotope composition and crassulacean acid metabolism in three plant communities along a water availability gradient

    E-Print Network [OSTI]

    2010-01-01

    gradient Á Tissue acidity Á Yucatan Introduction Crassulacean acid metabolism (metabolism in three plant communities along a water availability gradient

  4. Efficient Computation of Entropy Gradient for Semi-Supervised Conditional Random Fields

    E-Print Network [OSTI]

    McCallum, Andrew

    gradient that is significantly more efficient--having the same asymptotic time complexity as su- pervised

  5. Fabrication and evaluation of uniform and gradient density epoxies

    SciTech Connect (OSTI)

    Domeier, L.A.; Skala, D.M.; Goods, S.H. [and others

    1997-11-01

    Filled epoxy materials which vary in density in a designed manner have been fabricated and their mechanical properties evaluated. Density variations were produced by incorporating different volume fractions of either glass microballoons (GMB) or alumina. Several different sample types were evaluated including uniform density (0.8 g/cm{sup 3} < {rho} < 2.0 g/cm{sup 3}) samples and gradient density samples (GMB only, 0.8 g/cm{sup 3} < {rho} < 1.2 g/cm{sup 3}). The uniform density specimens were evaluated for the effects of filler type and concentration on modulus and toughness. Results indicated that addition of alumina filler significantly increased the resulting modulus while addition of GMB had little measurable effect. These differences could be understood in terms of the differing moduli of the additives relative to that of the epoxy matrix. In the former case the alumina particulates had a modulus much greater than that of the epoxy while in the latter case, the modulus of the GMB additive was only slightly greater than that of the matrix. Addition of either filler significantly degraded the toughness of the composite specimens and precluded the use of gradients to enhance toughness performance. Discontinuous {open_quotes}block{close_quotes} gradients used for testing were fabricated by simple sequential pours of formulations with different GMB loadings and were evaluated for modulus, strength and ductility. Continuous gradients were fabricated in process studies by programmed shifts in the peristaltic pumping/mixing ratio of epoxies filled with either alumina or GMB. None of the continuous gradient materials were mechanically tested. These results suggest that applications utilizing gradient materials containing alumina and similar high modulus fillers to provide designed stiffness rather than improved toughness are the most appropriate targets for future investigation.

  6. Gradient catastrophe and flutter in vortex filament dynamics

    E-Print Network [OSTI]

    B. G. Konopelchenko; G. Ortenzi

    2011-06-02

    Gradient catastrophe and flutter instability in the motion of vortex filament within the localized induction approximation are analyzed. It is shown that the origin if this phenomenon is in the gradient catastrophe for the dispersionless Da Rios system which describes motion of filament with slow varying curvature and torsion. Geometrically this catastrophe manifests as a rapid oscillation of a filament curve in a point that resembles the flutter of airfoils. Analytically it is the elliptic umbilic singularity in the terminology of the catastrophe theory. It is demonstrated that its double scaling regularization is governed by the Painlev\\'e-I equation.

  7. Gradient isolator for flow field of fuel cell assembly

    DOE Patents [OSTI]

    Ernst, William D. (Troy, NY)

    1999-01-01

    Isolator(s) include isolating material and optionally gasketing material strategically positioned within a fuel cell assembly. The isolating material is disposed between a solid electrolyte and a metal flow field plate. Reactant fluid carried by flow field plate channel(s) forms a generally transverse electrochemical gradient. The isolator(s) serve to isolate electrochemically a portion of the flow field plate, for example, transversely outward from the channel(s), from the electrochemical gradient. Further, the isolator(s) serve to protect a portion of the solid electrolyte from metallic ions.

  8. Gradient isolator for flow field of fuel cell assembly

    DOE Patents [OSTI]

    Ernst, W.D.

    1999-06-15

    Isolator(s) include isolating material and optionally gasketing material strategically positioned within a fuel cell assembly. The isolating material is disposed between a solid electrolyte and a metal flow field plate. Reactant fluid carried by flow field plate channel(s) forms a generally transverse electrochemical gradient. The isolator(s) serve to isolate electrochemically a portion of the flow field plate, for example, transversely outward from the channel(s), from the electrochemical gradient. Further, the isolator(s) serve to protect a portion of the solid electrolyte from metallic ions. 4 figs.

  9. Gradient-based Methods for Production Optimization of Oil Reservoirs

    E-Print Network [OSTI]

    Foss, Bjarne A.

    Gradient-based Methods for Production Optimization of Oil Reservoirs Eka Suwartadi Doctoral Thesis at NTNU, 2012:104 Printed by NTNU-Trykk #12;To my wife and my parents 3 #12;4 #12;Summary Production optimization for water flooding in the secondary phase of oil recovery is the main topic in this thesis

  10. Oil displacement through a porous medium with a temperature gradient

    E-Print Network [OSTI]

    Oliveira, C L N; Herrmann, H J

    2011-01-01

    We investigate the effect of a temperature gradient on oil recovery in a two-dimensional pore-network model. The oil viscosity depends on temperature as, $\\mu_o=exp(B/T)$, where $B$ is a physico-chemical parameter depending on the type of oil, and $T$ is the temperature. A temperature gradient is applied across the medium in the flow direction. Initially, the porous medium is saturated with oil and, then, another fluid is injected. We have considered two cases representing different injection strategies. In the first case, the invading fluid viscosity is constant (finite viscosity ratio) while in the second one, the invading fluid is inviscid (infinite viscosity ratio). Our results show that, for the case of finite viscosity ratio, recovery increases with $\\Delta T$ independently on strength or sign of the gradient. For an infinite viscosity ratio, a positive temperature gradient is necessary to enhance recovery. Moreover, we show that, for $\\Delta T>0$, the percentage of oil recovery generally decreases (inc...

  11. Scale Dependent Definitions of Gradient and Aspect and their Computation

    E-Print Network [OSTI]

    Utrecht, Universiteit

    (isoaspects) can aid in digital terrain modelling. Other geomorphological features in terrains are critical. Using such measures and classifications, the goal is for example to derive drainage maps, specify areas numerical value for gradient, and the classification convex or concave for plan and profile curvature

  12. Topological charge using cooling and the gradient flow

    E-Print Network [OSTI]

    Constantia Alexandrou; Andreas Athenodorou; Karl Jansen

    2015-09-14

    The equivalence of cooling to the gradient flow when the cooling step $n_c$ and the continuous flow step of gradient flow $\\tau$ are matched is generalized to gauge actions that include rectangular terms. By expanding the link variables up to subleading terms in perturbation theory, we relate $n_c$ and $\\tau$ and show that the results for the topological charge become equivalent when rescaling $\\tau \\simeq n_c/({3-15 c_1})$ where $c_1$ is the Symanzik coefficient multiplying the rectangular term. We, subsequently, apply cooling and the gradient flow using the Wilson, the Symanzik tree-level improved and the Iwasaki gauge actions to configurations produced with $N_f=2+1+1$ twisted mass fermions. We compute the topological charge, its distribution and the correlators between cooling and gradient flow at three values of the lattice spacing demonstrating that the perturbative rescaling $\\tau \\simeq n_c/({3-15 c_1})$ leads to equivalent results.

  13. Balanced Flow Geostrophic, Inertial, Gradient, and Cyclostrophic Flow

    E-Print Network [OSTI]

    Hennon, Christopher C.

    Balanced Flow Geostrophic, Inertial, Gradient, and Cyclostrophic Flow The types of atmospheric flows describe here have the following characteristics: 1) Steady state (meaning that the flows do surfaces) These are "idealized" flows, created by balances of horizontal forces. They provide a qualitative

  14. GRADIENT THEORY FOR PLASTICITY VIA HOMOGENIZATION OF DISCRETE DISLOCATIONS

    E-Print Network [OSTI]

    Garroni, Adriana

    GRADIENT THEORY FOR PLASTICITY VIA HOMOGENIZATION OF DISCRETE DISLOCATIONS ADRIANA GARRONI theory for plasticity from a model of discrete dislocations. We restrict our analysis to the case of a cylindrical symmetry for the crystal in exam, so that the mathematical formulation will involve a two

  15. Topological charge using cooling and the gradient flow

    E-Print Network [OSTI]

    Alexandrou, Constantia; Jansen, Karl

    2015-01-01

    The equivalence of cooling to the gradient flow when the cooling step $n_c$ and the continuous flow step of gradient flow $\\tau$ are matched is generalized to gauge actions that include rectangular terms. By expanding the link variables up to subleading terms in perturbation theory, we relate $n_c$ and $\\tau$ and show that the results for the topological charge become equivalent when rescaling $\\tau \\simeq n_c/({3-15 c_1})$ where $c_1$ is the Symanzik coefficient multiplying the rectangular term. We, subsequently, apply cooling and the gradient flow using the Wilson, the Symanzik tree-level improved and the Iwasaki gauge actions to configurations produced with $N_f=2+1+1$ twisted mass fermions. We compute the topological charge, its distribution and the correlators between cooling and gradient flow at three values of the lattice spacing demonstrating that the perturbative rescaling $\\tau \\simeq n_c/({3-15 c_1})$ leads to equivalent results.

  16. Evaluation of liquid lift approach to dual gradient drilling 

    E-Print Network [OSTI]

    Okafor, Ugochukwu Nnamdi

    2008-10-10

    In the past, the oil and gas industry has typically used the single gradient system to drill wells offshore. With this system the bottom hole pressure was controlled by a mud column extending from the drilling rig to the bottom of the wellbore...

  17. A latitudinal diversity gradient in planktonic marine bacteria

    E-Print Network [OSTI]

    Brown, James H.

    A latitudinal diversity gradient in planktonic marine bacteria Jed A. Fuhrman* , Joshua A. Steele and attribute this to their high abundance and dispersal capabilities would suggest that bacteria, the smallest. Despite the high abundance and potentially high dispersal of bacteria, they exhibit geographic patterns

  18. Seasonal mass balance gradients in Norway L. A. Rasmussen1

    E-Print Network [OSTI]

    Rasmussen, L.A.

    16 Aug 05 Seasonal mass balance gradients in Norway L. A. Rasmussen1 and L. M. Andreassen2 1 Norwegian Water Resources and Energy Directorate (NVE) P. O. Box 5091 Majorstua, N-0301 Oslo, Norway in Norway exists in their profiles of both seasonal balances, winter bw(z) and summer bs(z). Unlike many

  19. University of Alberta Gradient Temporal-Difference Learning Algorithms

    E-Print Network [OSTI]

    Sutton, Richard S.

    University of Alberta Gradient Temporal-Difference Learning Algorithms by Hamid Reza Maei A thesis, Alberta Permission is hereby granted to the University of Alberta Libraries to reproduce single copies the thesis is converted to, or otherwise made available in digital form, the University of Alberta

  20. Capillary forces and osmotic gradients in salt water -oil systems

    E-Print Network [OSTI]

    Kjelstrup, Signe

    Capillary forces and osmotic gradients in salt water - oil systems Georg Ellila Chemical study. This is to my knowledge the first time the transport mechanisms in capillary oil-salt water and the Vista Program. 1 #12;Abstract This project looks at the capillary systems with salt water and oil

  1. University of Alberta Gradient Temporal-Difference Learning Algorithms

    E-Print Network [OSTI]

    Sutton, Richard S.

    of convergence--in on-policy problems. #12;Acknowledgements This PhD thesis is developed through collaboration;Abstract We present a new family of gradient temporal-difference (TD) learning methods with func- tion- proximation. In particular, convergence cannot be guaranteed for these methods when they are used with off-policy

  2. Intermittency in Turbulent Diffusion Models with a Mean Gradient

    E-Print Network [OSTI]

    Majda, Andrew J.

    Intermittency in Turbulent Diffusion Models with a Mean Gradient Andrew J Majda and Xin T TongE30, 62G32 Submitted to: Nonlinearity 1. Introduction Turbulent diffusion is the transportation and diffusion. Its application ranges from the spread of hazardous plumes and mixing properties of turbulent

  3. Tubular precipitation and redox gradients on a bubbling template

    E-Print Network [OSTI]

    Goldstein, Raymond E.

    Tubular precipitation and redox gradients on a bubbling template David A. Stone* and Raymond E) Tubular structures created by precipitation abound in nature, from chimneys at hydrothermal vents to soda oxides precipitate on the surface of bubbles that linger at the tube rim and then detach, leaving behind

  4. Fabrication process for a gradient index x-ray lens

    DOE Patents [OSTI]

    Bionta, Richard M. (Livermore, CA); Makowiecki, Daniel M. (Livermore, CA); Skulina, Kenneth M. (Livermore, CA)

    1995-01-01

    A process for fabricating high efficiency x-ray lenses that operate in the 0.5-4.0 keV region suitable for use in biological imaging, surface science, and x-ray lithography of integrated circuits. The gradient index x-ray optics fabrication process broadly involves co-sputtering multi-layers of film on a wire, followed by slicing and mounting on block, and then ion beam thinning to a thickness determined by periodic testing for efficiency. The process enables the fabrication of transmissive gradient index x-ray optics for the 0.5-4.0 keV energy range. This process allows the fabrication of optical elements for the next generation of imaging and x-ray lithography instruments m the soft x-ray region.

  5. Gradient Plasticity Model and its Implementation into MARMOT

    SciTech Connect (OSTI)

    Barker, Erin I.; Li, Dongsheng; Zbib, Hussein M.; Sun, Xin

    2013-08-01

    The influence of strain gradient on deformation behavior of nuclear structural materials, such as boby centered cubic (bcc) iron alloys has been investigated. We have developed and implemented a dislocation based strain gradient crystal plasticity material model. A mesoscale crystal plasticity model for inelastic deformation of metallic material, bcc steel, has been developed and implemented numerically. Continuum Dislocation Dynamics (CDD) with a novel constitutive law based on dislocation density evolution mechanisms was developed to investigate the deformation behaviors of single crystals, as well as polycrystalline materials by coupling CDD and crystal plasticity (CP). The dislocation density evolution law in this model is mechanism-based, with parameters measured from experiments or simulated with lower-length scale models, not an empirical law with parameters back-fitted from the flow curves.

  6. Fabrication process for a gradient index x-ray lens

    DOE Patents [OSTI]

    Bionta, R.M.; Makowiecki, D.M.; Skulina, K.M.

    1995-01-17

    A process is disclosed for fabricating high efficiency x-ray lenses that operate in the 0.5-4.0 keV region suitable for use in biological imaging, surface science, and x-ray lithography of integrated circuits. The gradient index x-ray optics fabrication process broadly involves co-sputtering multi-layers of film on a wire, followed by slicing and mounting on block, and then ion beam thinning to a thickness determined by periodic testing for efficiency. The process enables the fabrication of transmissive gradient index x-ray optics for the 0.5-4.0 keV energy range. This process allows the fabrication of optical elements for the next generation of imaging and x-ray lithography instruments in the soft x-ray region. 13 figures.

  7. Radiography to measure the longitudinal density gradients of Pd compacts

    SciTech Connect (OSTI)

    Back, D.D.

    1992-05-14

    This study used radiography to detect and quantify density gradients in green compacts of Palladium powder. Ultrasonic velocity measurements had been tried previously, but they were affected by material properties, in addition to the density, so that an alternative was sought. The alternative technique used radiographic exposures of a series of standard compacts whose density is known and correlated with the radiographic film density. These correlations are used to predict the density in subsequent compacts.

  8. Gradient instabilities of electromagnetic waves in Hall thruster plasma

    SciTech Connect (OSTI)

    Tomilin, Dmitry

    2013-04-15

    This paper presents a linear analysis of gradient plasma instabilities in Hall thrusters. The study obtains and analyzes the dispersion equation of high-frequency electromagnetic waves based on the two-fluid model of a cold plasma. The regions of parameters corresponding to unstable high frequency modes are determined and the dependence of the increments and intrinsic frequencies on plasma parameters is obtained. The obtained results agree with those of previously published studies.

  9. Determination of dispersivities from a natural-gradient dispersion test 

    E-Print Network [OSTI]

    Hoover, Caroline Marie

    1985-01-01

    Model DESCRIPTION OF THE NATURAL-GRADIENT DISPERSION TEST. Site Geology. Methodology Summary of Results. APPLICATION OF METHODS. Ideal Pl ume Study. Characterization of the Iterative Diagrams. . . Sensitivity Analyses. Field Tracer Study... with contaminant hydrogeology. Cherry et al. (1975) defines contaminant hydrogeology as the application of hydrogeological and geochemical theory and practice to the protection of aquifers and surface waters from contamination, and to the design and monitoring...

  10. Preparation of Genomic DNA from Hawaiian Bobtail Squid (Euprymna scolopes) Tissue by Cesium Chloride Gradient

    E-Print Network [OSTI]

    Ruby, Edward G.

    by Cesium Chloride Gradient Centrifugation Patricia N. Lee1,2 , Margaret J. McFall-Ngai3 , Patrick Callaerts from adult bobtail squid (Euprymna scolopes) tissues by cesium chloride (CsCl) gradient centrifugation

  11. Generating spatially and temporally controllable long-range concentration gradients in a microfluidic device

    E-Print Network [OSTI]

    Vidula, Mahesh K.

    Concentration gradients have important applications in chemical and biological studies. Here we have achieved rapid generation of spatially and temporally controllable concentration gradients of diffusible molecules (i.e. ...

  12. Creation of nonlinear density gradients for use in internal wave research

    E-Print Network [OSTI]

    Harris, Victoria Siân

    2007-01-01

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

  13. An evaluation of subsea pump technologies that can be used to achieve dual gradient drilling 

    E-Print Network [OSTI]

    Oluwadairo, Tolulope

    2009-05-15

    Dual Gradient Drilling is an exciting technology which promises to solve the current technical hurdles and economic risks of Deepwater Drilling. Several techniques for Dual Gradient Drilling have been proposed to the ...

  14. Magnetic field gradients in solar wind plasma and geophysics periods

    E-Print Network [OSTI]

    A. Bershadskii

    2006-11-16

    Using recent data obtained by Advanced Composition Explorer (ACE) the pumping scale of the magnetic field gradients of the solar wind plasma has been calculated. This pumping scale is found to be equal to 24h $\\pm$ 2h. The ACE spacecraft orbits at the L1 libration point which is a point of Earth-Sun gravitational equilibrium about 1.5 million km from Earth. Since the Earth's magnetosphere extends into the vacuum of space from approximately 80 to 60,000 kilometers on the side toward the Sun the pumping scale cannot be a consequence of the 24h-period of the Earth's rotation. Vise versa, a speculation is suggested that for the very long time of the coexistence of Earth and of the solar wind the weak interaction between the solar wind and Earth could lead to stochastic synchronization between the Earth's rotation and the pumping scale of the solar wind magnetic field gradients. This synchronization could transform an original period of the Earth's rotation to the period close to the pumping scale of the solar wind magnetic field gradients.

  15. Atmospheric gradients and the stability of expanding jets. [Astrophysics

    SciTech Connect (OSTI)

    Hardee, P.E.; Koupelis, T.; Norman, M.L.; Clarke, D.A. Illinois, University, Urbana )

    1991-05-01

    Numerical simulations of adiabatically expanding slab jets in initial static pressure balance with an external atmosphere have been performed and compared to predictions made by a linear analysis of the stability of expanding jets. It is found that jets are stabilized by jet expansion as predicted by the linear analysis. It is also found that an expanding jet can be destabilized by a positive temperature gradient or temperature jump in the surrounding medium which lowers the Mach number defined by the external sound speed. A temperature gradient or jump is more destabilizing than would be predicted by a linear stability analysis. The enhanced instability compared to an isothermal atmosphere with identical pressure gradient is a result of the reduced external Mach number and a result of a higher jet density relative to the density in the external medium and higher ram speed. Other differences between predictions made by the linear theory and the simulations can be understood qualitatively as a result of a change in wave speed as the wave amplitude increases. 12 refs.

  16. Transcriptomic profiling of the giant kelp, Macrocystis pyrifera, across environmental gradients

    E-Print Network [OSTI]

    Konotchick, Talina Helen

    2012-01-01

    gradients can influence morphology indicating that the nitrate climate can affect change in the regulatory mechanisms and metabolism

  17. A fourth-order nonlinear PDE as gradient flow of the Fisher information in Wasserstein spaces

    E-Print Network [OSTI]

    Savaré, Giuseppe

    A fourth-order nonlinear PDE as gradient flow of the Fisher information in Wasserstein spaces://www.imati.cnr.it/savare A-HYKE2, april 2004 ­ p.1 #12;Plan 1. The fourth order equation and its structure 2. Gradient flows. The fourth order equation and its structure 2. Gradient flows and Wasserstein distance 3. Main results

  18. Eddy currents in a gradient coil, modelled as circular loops of strips

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    Eddy currents in a gradient coil, modelled as circular loops of strips J.M.B. Kroot, S.J.L. van. Due to induction eddy currents occur which lead to the so-called edge-effect. The edge- effect depends the gradient coils themselves. Eddy currents occur, causing perturbations on the expected gradient field

  19. Enhancement of charged macromolecule capture by nanopores in a salt gradient

    E-Print Network [OSTI]

    Levine, Alex J.

    Enhancement of charged macromolecule capture by nanopores in a salt gradient Tom Choua Department. However, recent experiments have shown that salt concentration gradients applied across nanopores can also length, we obtain accurate analytic expressions showing how salt gradients control the local conductivity

  20. Experimental and theoretical studies of oxygen gradients in rat pial microvessels

    E-Print Network [OSTI]

    Popel, Aleksander S.

    no substantial impact on the transmural PO2 gradient. Journal of Cerebral Blood Flow & Metabolism (2008) 28, 1597Experimental and theoretical studies of oxygen gradients in rat pial microvessels Maithili Sharan1 near cortical arterioles and transmural PO2 gradients in the pial arterioles of the rat. Under control

  1. On the Relation Between Steep Monoclinal Flexure Zones and Steep Hydraulic Gradients

    E-Print Network [OSTI]

    Lyakhovsky, Vladimir

    On the Relation Between Steep Monoclinal Flexure Zones and Steep Hydraulic Gradients by Y. Yechieli1, U. Kafri2, S. Wollman2, V. Lyakhovsky2, and R. Weinberger2 Abstract Steep hydraulic gradients of the hydraulic conductivity, which is responsible for the steep gradients, has seldom been studied. We present

  2. General Method for Forming Micrometer-Scale Lateral Chemical Gradients in Polymer Brushes

    E-Print Network [OSTI]

    Braun, Paul

    ABSTRACT: We report a general diffusion based method to form micrometer-scale lateral chemical gradientsGeneral Method for Forming Micrometer-Scale Lateral Chemical Gradients in Polymer Brushes Hyung chemical potential gradients with a diversity of shapes. INTRODUCTION Surfaces presenting chemical

  3. Validation of electron temperature gradient turbulence in the Columbia Linear Machine

    E-Print Network [OSTI]

    Lin, Zhihong

    Validation of electron temperature gradient turbulence in the Columbia Linear Machine X. R. Fu,1 W hydrogen plasma of the Columbia Linear Machine. Electron temperature profiles with strong gradients; published online 6 March 2012) The electron temperature gradient (ETG) mode, which is a universal mechanism

  4. A New Electrochemical Gradient Generator in Thylakoid Membranes of Green Fabrice Rappaport, Giovanni Finazzi, Yves Pierre,| and Pierre Bennoun*,

    E-Print Network [OSTI]

    A New Electrochemical Gradient Generator in Thylakoid Membranes of Green Algae Fabrice Rappaport generator present in the thylakoid membranes. We have studied the permanent electrochemical gradient (µ~)1

  5. Multi-Scale Gradient Expansion of the Turbulent Stress Tensor

    E-Print Network [OSTI]

    Gregory L. Eyink

    2005-12-10

    We develop an expansion of the turbulent stress tensor into a double series of contributions from different scales of motion and different orders of space-derivatives of velocity, a Multi-Scale Gradient (MSG) expansion. The expansion is proved to converge to the exact stress, as a consequence of the locality of cascade both in scale and in space. Simple estimates show, however, that the convergence rate may be slow for the expansion in spatial gradients of very small scales. Therefore, we develop an approximate expansion, based upon an assumption that similar or `coherent' contributions to turbulent stress are obtained from disjoint subgrid regions. This Coherent-Subregions Approximation (CSA) yields an MSG expansion that can be proved to converge rapidly at all scales and is hopefully still reasonably accurate. As an application, we consider the cascades of energy and helicity in three-dimensional turbulence. To first order in velocity-gradients, the stress has three contributions: a tensile stress along principal directions of strain, a contractile stress along vortex lines, and a shear stress proportional to `skew-strain.' While vortex-stretching plays the major role in energy cascade, there is a second, less scale-local contribution from `skew-strain'. For helicity cascade the situation is reversed, and it arises scale-locally from `skew-strain' while the stress along vortex-lines gives a secondary, less scale-local contribution. These conclusions are illustrated with simple exact solutions of 3D Euler equations. In the first, energy cascade occurs by Taylor's mechanism of stretching and spin-up of small-scale vortices due to large-scale strain. In the second, helicity cascade occurs by `twisting' of small-scale vortex filaments due to a large-scale screw.

  6. SLIM, Short-pulse Technology for High Gradient Induction Accelerators

    SciTech Connect (OSTI)

    Arntz, Floyd; Kardo-Sysoev, A.; Krasnykh, A.; /SLAC

    2008-12-16

    A novel short-pulse concept (SLIM) suited to a new generation of a high gradient induction particle accelerators is described herein. It applies advanced solid state semiconductor technology and modern microfabrication techniques to a coreless induction method of charged particle acceleration first proven on a macro scale in the 1960's. Because this approach avoids use of magnetic materials there is the prospect of such an accelerator working efficiently with accelerating pulses in the nanosecond range and, potentially, at megahertz pulse rates. The principal accelerator section is envisioned as a stack of coreless induction cells, the only active element within each being a single, extremely fast (subnanosecond) solid state opening switch: a Drift Step Recovery Diode (DSRD). Each coreless induction cell incorporates an electromagnetic pulse compressor in which inductive energy developed within a transmission-line feed structure over a period of tens of nanoseconds is diverted to the acceleration of the passing charge packet for a few nanoseconds by the abrupt opening of the DSRD switch. The duration of this accelerating output pulse--typically two-to-four nanoseconds--is precisely determined by a microfabricated pulse forming line connected to the cell. Because the accelerating pulse is only nanoseconds in duration, longitudinal accelerating gradients approaching 100 MeV per meter are believed to be achievable without inciting breakdown. Further benefits of this approach are that, (1) only a low voltage power supply is required to produce the high accelerating gradient, and, (2) since the DSRD switch is normally closed, voltage stress is limited to a few nanoseconds per period, hence the susceptibility to hostile environment conditions such as ionizing radiation, mismatch (e.g. in medical applications the peak beam current may be low), strong electromagnetic noise levels, etc is expected to be minimal. Finally, we observe the SLIM concept is not limited to linac applications; for instance, it could be employed to both accelerate the beam and to stabilize the superbunch mode of operation in circular track machines.

  7. Fabrication of high gradient insulators by stack compression

    DOE Patents [OSTI]

    Harris, John Richardson; Sanders, Dave; Hawkins, Steven Anthony; Norona, Marcelo

    2014-04-29

    Individual layers of a high gradient insulator (HGI) are first pre-cut to their final dimensions. The pre-cut layers are then stacked to form an assembly that is subsequently pressed into an HGI unit with the desired dimension. The individual layers are stacked, and alignment is maintained, using a sacrificial alignment tube that is removed after the stack is hot pressed. The HGI's are used as high voltage vacuum insulators in energy storage and transmission structures or devices, e.g. in particle accelerators and pulsed power systems.

  8. Electron geodesic acoustic modes in electron temperature gradient mode turbulence

    SciTech Connect (OSTI)

    Anderson, Johan; Nordman, Hans [Department of Earth and Space Sciences, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden); Singh, Raghvendra; Kaw, Predhiman [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India)

    2012-08-15

    In this work, the first demonstration of an electron branch of the geodesic acoustic mode (el-GAM) driven by electron temperature gradient (ETG) modes is presented. The work is based on a fluid description of the ETG mode retaining non-adiabatic ions and the dispersion relation for el-GAMs driven nonlinearly by ETG modes is derived. A new saturation mechanism for ETG turbulence through the interaction with el-GAMs is found, resulting in a significantly enhanced ETG turbulence saturation level compared to the mixing length estimate.

  9. Conjugate gradient solvers on Intel Xeon Phi and NVIDIA GPUs

    E-Print Network [OSTI]

    O. Kaczmarek; C. Schmidt; P. Steinbrecher; M. Wagner

    2014-11-17

    Lattice Quantum Chromodynamics simulations typically spend most of the runtime in inversions of the Fermion Matrix. This part is therefore frequently optimized for various HPC architectures. Here we compare the performance of the Intel Xeon Phi to current Kepler-based NVIDIA Tesla GPUs running a conjugate gradient solver. By exposing more parallelism to the accelerator through inverting multiple vectors at the same time, we obtain a performance greater than 300 GFlop/s on both architectures. This more than doubles the performance of the inversions. We also give a short overview of the Knights Corner architecture, discuss some details of the implementation and the effort required to obtain the achieved performance.

  10. High and ulta-high gradient quadrupole magnets

    SciTech Connect (OSTI)

    Brunk, W.O.; Walz, D.R.

    1985-05-01

    Small bore conventional dc quadrupoles with apertures from 1 to 2.578cm were designed and prototypes built and measured. New fabrication techniques including the use of wire electric discharge milling (EDM) to economically generate the pole tip contours and aperture tolerances are described. Magnetic measurement data from a prototype of a 1cm aperture quadrupole with possible use in future e/sup +//e/sup -/ super colliders are presented. At a current of 400A, the lens achieved a gradient of 2.475 T/cm, and had an efficiency of 76.6%.

  11. Category:Thermal Gradient Holes | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoopButte County,Camilla,Thermal Gradient Holes Jump to: navigation, search

  12. gradient, df/dz, across the condensate. Such a gradient may be imprinted by a condensate velocity, because df=dz mv=h, where

    E-Print Network [OSTI]

    Ganichev, Sergey

    gradient, df/dz, across the condensate. Such a gradient may be imprinted by a condensate velocity,13 , which accounts for far fewer atoms than the number contained in the initial repulsive condensate. Apparently, most of the atoms from the collapsing condensate are lost, while only a small fraction remain

  13. file://L:\DOE-hanford.gov\public\boards\hab\advice\advice84b.ht

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorkingLosThe 26th Annual Conference onDickAlThe Honorable Federico2000The

  14. file://L:\DOE-hanford.gov\public\boards\hab\advice\advice94b.ht

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorkingLosThe 26th Annual Conference onDickAlThe HonorableJohnJohn 1200

  15. Feedback Mechanism for Microtubule Length Regulation by Stathmin Gradients

    E-Print Network [OSTI]

    Maria Zeitz; Jan Kierfeld

    2014-12-09

    We formulate and analyze a theoretical model for the regulation of microtubule (MT) polymerization dynamics by the signaling proteins Rac1 and stathmin. In cells, the MT growth rate is inhibited by cytosolic stathmin, which, in turn, is inactivated by Rac1. Growing MTs activate Rac1 at the cell edge, which closes a positive feedback loop. We investigate both tubulin sequestering and catastrophe promotion as mechanisms for MT growth inhibition by stathmin. For a homogeneous stathmin concentration in the absence of Rac1, we find a switch-like regulation of the MT mean length by stathmin. For constitutively active Rac1 at the cell edge, stathmin is deactivated locally, which establishes a spatial gradient of active stathmin. In this gradient, we find a stationary bimodal MT length distributions for both mechanisms of MT growth inhibition by stathmin. One subpopulation of the bimodal length distribution can be identified with fast growing and long pioneering MTs in the region near the cell edge, which have been observed experimentally. The feedback loop is closed through Rac1 activation by MTs. For tubulin sequestering by stathmin, this establishes a bistable switch with two stable states: one stable state corresponds to upregulated MT mean length and bimodal MT length distributions, i.e., pioneering MTs; the other stable state corresponds to an interrupted feedback with short MTs. Stochastic effects as well as external perturbations can trigger switching events. For catastrophe promoting stathmin we do not find bistability.

  16. The latitudinal gradient of the NO peak density

    SciTech Connect (OSTI)

    Fesen, C.G.; Rusch, D.W. (Univ. of Colorado, Boulder (United States)); Gerard, J.C. (Univ. de Liege (Belgium))

    1990-11-01

    The latitudinal gradients of the maximum nitric oxide densities near 110 km are presented for solstice and equinox periods from 1982 through 1985 as observed by the Solar Mesosphere Explorer satellite. The data indicate that the response of the maximum NO densities to the declining level of solar activity is latitudinally and seasonally dependent: the polar regions exhibit little sensitivity to solar activity, while the low latitude NO responds strongly. The data also reveal marked asymmetries in the latitudinal structure of the two hemispheres for each season. During June solstice periods, the latitudinal distribution is fairly flat, unlike December solstice periods which tend to show a definite minimum near 30{degree}N. Similarly, March data show very little latitudinal variation in the NO peak density between about {plus minus} 40{degree}, while the September data show marked gradients for the later years. The SME data further indicate that the nitric oxide densities vary considerably from day to day, even during very quiet geomagnetic periods, suggesting that the concept of an average distribution is of limited usefulness in understanding nitric oxide. A two-dimensional model is used to simualte the June solar cycle minimum data. The latitudinally averaged magnitudes of the observed NO peak densities are reproduced reasonably well by the model, but the shape of the latitudinal variation is not.

  17. A linear helicon plasma device with controllable magnetic field gradient

    SciTech Connect (OSTI)

    Barada, Kshitish K.; Chattopadhyay, P. K.; Ghosh, J.; Kumar, Sunil; Saxena, Y. C. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India)

    2012-06-15

    Current free double layers (CFDLs) are localized potential structures having spatial dimensions - Debye lengths and potential drops of more than local electron temperature across them. CFDLs do not need a current for them to be sustained and hence they differ from the current driven double layers. Helicon antenna produced plasmas in an expanded chamber along with an expanding magnetic field have shown the existence of CFDL near the expansion region. A helicon plasma device has been designed, fabricated, and installed in the Institute for Plasma Research, India to study the role of maximum magnetic field gradient as well as its location with respect to the geometrical expansion region of the chamber in CFDL formation. The special feature of this machine consisting of two chambers of different radii is its capability of producing different magnetic field gradients near the physical boundary between the two chambers either by changing current in one particular coil in the direction opposite to that in other coils and/or by varying the position of this particular coil. Although, the machine is primarily designed for CFDL experiments, it is also capable of carrying out many basic plasma physics experiments such as wave propagation, wave coupling, and plasma instabilities in a varying magnetic field topology. In this paper, we will present the details of the machine construction, its specialties, and some preliminary results about the production and characterization of helicon plasma in this machine.

  18. Convergence in gradient systems with branching of equilibria

    SciTech Connect (OSTI)

    Galaktionov, V A [University of Bath (United Kingdom); Pohozaev, Stanislav I [Steklov Mathematical Institute, Russian Academy of Sciences (Russian Federation); Shishkov, A E [Institute of Applied Mathematics and Mechanics of the National Academy of Sciences of Ukraine, Donetsk (Ukraine)

    2007-06-30

    The basic model is a semilinear elliptic equation with coercive C{sup 1} non-linearity: {delta}{psi}+f({psi})=0 in {omega}, {psi}=0 on {partial_derivative}{omega}, where {omega} subset of R{sup N} is a bounded smooth domain. The main hypothesis (H{sub R}) about resonance branching is as follows: if a branching of equilibria occurs at a point {psi} with k-dimensional kernel of the linearized operator {delta}+f'({psi})I, then the branching subset S{sub k} at {psi} is a locally smooth k-dimensional manifold. For N=1 the first result on the stabilization to a single equilibrium is due to Zelenyak (1968). It is shown that Zelenyak's approach, which is based on the analysis of Lyapunov functions, can be extended to general gradient systems in Hilbert spaces with smooth resonance branching. The case of asymptotically small non-autonomous perturbations of such systems is also considered. The approach developed here represents an alternative to Hale's stabilization method (1992) and other similar techniques in the theory of gradient systems. Bibliography: 32 titles.

  19. Circumstellar Disks revealed by $H$/$K$ Flux Variation Gradients

    E-Print Network [OSTI]

    Nuñez, F Pozo; Chini, R; Ramolla, M; Hodapp, K -W

    2015-01-01

    The variability of young stellar objects (YSO) changes their brightness and color preventing a proper classification in traditional color-color and color magnitude diagrams. We have explored the feasibility of the flux variation gradient (FVG) method for YSOs, using $H$ and $K$ band monitoring data of the star forming region RCW\\,38 obtained at the University Observatory Bochum in Chile. Simultaneous multi-epoch flux measurements follow a linear relation $F_{H}=\\alpha + \\beta \\cdot F_{K}$ for almost all YSOs with large variability amplitude. The slope $\\beta$ gives the mean $HK$ color temperature $T_{var}$ of the varying component. Because $T_{var}$ is hotter than the dust sublimation temperature, we have tentatively assigned it to stellar variations. If the gradient does not meet the origin of the flux-flux diagram, an additional non- or less-varying component may be required. If the variability amplitude is larger at the shorter wavelength, e.g. $\\alpha 0$, the component is hotter like a scattering halo or...

  20. Dielectric-Lined High-Gradient Accelerator Structure

    SciTech Connect (OSTI)

    Jay L. Hirshfield

    2012-04-24

    Rectangular particle accelerator structures with internal planar dielectric elements have been studied, with a view towards devising structures with lower surface fields for a given accelerating field, as compared with structures without dielectrics. Success with this concept is expected to allow operation at higher accelerating gradients than otherwise on account of reduced breakdown probabilities. The project involves studies of RF breakdown on amorphous dielectrics in test cavities that could enable high-gradient structures to be built for a future multi-TeV collider. The aim is to determine what the limits are for RF fields at the surfaces of selected dielectrics, and the resulting acceleration gradient that could be achieved in a working structure. The dielectric of principal interest in this study is artificial CVD diamond, on account of its advertised high breakdown field ({approx}2 GV/m for dc), low loss tangent, and high thermal conductivity. Experimental studies at mm-wavelengths on materials and structures for achieving high acceleration gradient were based on the availability of the 34.3 GHz third-harmonic magnicon amplifier developed by Omega-P, and installed at the Yale University Beam Physics Laboratory. Peak power from the magnicon was measured to be about 20 MW in 0.5 {micro}s pulses, with a gain of 54 dB. Experiments for studying RF high-field effects on CVD diamond samples failed to show any evidence after more than 10{sup 5} RF pulses of RF breakdown up to a tangential surface field strength of 153 MV/m; studies at higher fields were not possible due to a degradation in magnicon performance. A rebuild of the tube is underway at this writing. Computed performance for a dielectric-loaded rectangular accelerator structure (DLA) shows highly competitive properties, as compared with an existing all-metal structure. For example, comparisons were made of a DLA structure having two planar CVD diamond elements with a all-metal CERN structure HDS operating at 30 GHz. It was shown that the ratio of maximum surface electric field to accelerating field at the metal wall is only 0.35-0.4 for DLA, much smaller than the value 2.2 for HDS; and the ratio of surface magnetic field to accelerating field is 3.0 mA/V for DLA, compared with 3.45 mA/V for HDS. These values bode well for DLA in helping to avoid breakdown and to reducing pulsed surface heating and fatigue. The shunt impedance is found to be 160-175 M{Omega}/m for DLA, as compared to 99 M{Omega}/m for HDS. Conclusions are reached from this project that CVD diamond appears promising as a dielectric with a high threshold for RF breakdown, and that rectangular accelerator structures can be devised using planar CVD diamond elements that could be operated at higher acceleration gradients with low probability of RF breakdown, as compared with corresponding all-metallic structures.

  1. Improved gradient flow for step scaling function and scale setting

    E-Print Network [OSTI]

    Anna Hasenfratz

    2015-01-30

    The gradient flow renormalized coupling offers a simple and relatively inexpensive way to calculate the step scaling function and the lattice scale, but both applications can be hindered by large lattice artifacts. Recently we introduced an empirical non-perturbative improvement that can reduce, even remove $\\mathcal{O}(a^2)$ lattice artifacts. The method is easy to implement and can be applied to any lattice gauge theory of interest both in step scaling studies and for scale setting. In this talk I will briefly review this improvement method and discuss its application for determining the discrete $\\beta$ function of the 8 and 12 flavor SU(3) systems and for improved scale setting in 2+1+1 flavor QCD

  2. Renormalization of the Polyakov loop with gradient flow

    E-Print Network [OSTI]

    P. Petreczky; H. -P. Schadler

    2015-11-24

    We use the gradient flow for the renormalization of the Polyakov loop in various representations. Using 2+1 flavor QCD with highly improved staggered quarks and lattices with temporal extents of $N_\\tau=6$, $8$, $10$ and $12$ we calculate the renormalized Polyakov loop in many representations including fundamental, sextet, adjoint, decuplet, 15-plet, 24-plet and 27-plet. This approach allows for the calculations of the renormalized Polyakov loops over a large temperature range from $T=116$ MeV up to $T=815$ MeV, with small errors not only for the Polyakov loop in fundamental representation, but also for the Polyakov loops in higher representations. We compare our results with standard renormalization schemes and discuss the Casimir scaling of the Polyakov loops.

  3. On O($a^2$) effects in gradient flow observables

    E-Print Network [OSTI]

    Alberto Ramos; Stefan Sint

    2015-04-18

    In lattice gauge theories, the gradient flow has been used extensively both, for scale setting and for defining finite volume renormalization schemes for the gauge coupling. Unfortunately, rather large cutoff effects have been observed in some cases. We here investigate these effects to leading order in perturbation theory, considering various definitions of the lattice observable, the lattice flow equation and the Yang Mills lattice action. These considerations suggest an improved set- up for which we perform a scaling test in the pure SU(3) gauge theory, demonstrating strongly reduced cutoff effects. We then attempt to obtain a more complete understanding of the structure of O($a^2$) effects by applying Symanzik's effective theory approach to the 4+1 dimensional local field theory with flow time as the fifth dimension. From these considerations we are led to a fully O($a^2$) improved set-up the study of which is left to future work.

  4. Modified Magnicon for High-Gradient Accelerator R&D

    SciTech Connect (OSTI)

    Jay L. Hirshfield

    2011-12-19

    Analysis, and low-power cold tests are described on a modified design intended for the Ka-band pulsed magnicon now in use for high-gradient accelerator R and D and rare elementary particle searches at the Yale University Beam Physics Laboratory. The modification is mainly to the output cavity of the magnicon, which presently operates in the TM310 mode. It is proposed to substitute for this a dual-chamber TE311 cavity structure. The first chamber is to extract about 40% of the beam power (about 25 MW) at 34.272 GHz, while the second chamber is to convey the power to four WR-28 output waveguides. Minor design changes are also proposed for the penultimate 11.424 GHz cavity and the beam collector. The intention of these design changes is to allow the magnicon to operate reliably 24/7, with minor sensitivity to operating parameters.

  5. Operational experience with CW high gradient and high QL cryomodules

    SciTech Connect (OSTI)

    Hovater, J. Curt [JLAB; Allison, Trent L. [JLAB; Bachimanchi, Ramakrishna [JLAB; Daly, Edward F. [JLAB; Drury, Michael A. [JLAB; Lahti, George E. [JLAB; Mounts, Clyde I. [JLAB; Nelson, Richard M. [JLAB; Plawski, Tomasz E. [JLAB

    2014-12-01

    The Continuous Electron Beam Accelerator Facility (CEBAF) energy upgrade from 6 GeV to 12 GeV includes the installation of ten new 100 MV cryomodules (80 cavities). The superconducting RF cavities are designed to operate CW at an accelerating gradient of 19.3 MV/m with a QL of 3×107. The RF system employs single cavity control using new digital LLRF controls and 13 kW klystrons. Recently, all of the new cryomodules and associated RF hardware and software have been commissioned and operated in the CEBAF accelerator. Electrons at linac currents up to 10 ?A have been successfully accelerated and used for nuclear physics experiments. This paper reports on the commissioning and operation of the cryomodules and RF system.

  6. Accretion, radial flows and abundance gradients in spiral galaxies

    E-Print Network [OSTI]

    Pezzulli, Gabriele

    2015-01-01

    The metal-poor gas continuously accreting onto the discs of spiral galaxies is unlikely to arrive from the intergalactic medium (IGM) with exactly the same rotation velocity as the galaxy itself and even a small angular momentum mismatch inevitably drives radial gas flows within the disc, with significant consequences to galaxy evolution. Here we provide some general analytic tools to compute accretion profiles, radial gas flows and abundance gradients in spiral galaxies as a function of the angular momentum of accreting material. We generalize existing solutions for the decomposition of the gas flows, required to reproduce the structural properties of galaxy discs, into direct accretion from the IGM and a radial mass flux within the disc. We then solve the equation of metallicity evolution in the presence of radial gas flows with a novel method, based on characteristic lines, which greatly reduces the numerical demand on the computation and sheds light on the crucial role of boundary conditions on the abunda...

  7. (2+1)-flavor QCD Thermodynamics from the Gradient Flow

    E-Print Network [OSTI]

    Itou, Etsuko; Taniguchi, Yusuke; Umeda, Takashi

    2015-01-01

    Recently, we proposed a novel method to define and calculate the energy-momentum tensor (EMT) in lattice gauge theory on the basis of the Yang-Mills gradient flow [1]. In this proceedings, we summarize the basic idea and technical steps to obtain the bulk thermodynamic quantities in lattice gauge theory using this method for the quenched and $(2+1)$-flavor QCD. The revised results of integration measure (trace anomaly) and entropy density of the quenched QCD with corrected coefficients are shown. Furthermore, we also show the flow time dependence of the parts of EMT including the dynamical fermions. This work is based on a joint-collaboration between FlowQCD and WHOT QCD.

  8. Shape measurement biases from underfitting and ellipticity gradients

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

    Bernstein, Gary M.

    2010-08-21

    With this study, precision weak gravitational lensing experiments require measurements of galaxy shapes accurate to more »and/or by sampling. We propose a new shape-measurement technique that is explicitly confined to observable regions of k-space. A second bias arises for galaxies whose ellipticity varies with radius. For most shape-measurement methods, such galaxies are subject to "ellipticity gradient bias". We show how to reduce such biases by factors of 20–100 within the new shape-measurement method. The resulting shear estimator has multiplicative errors 3 for high-S/N images, even for highly asymmetric galaxies. Without any training or recalibration, the new method obtains Q = 3000 in the GREAT08 Challenge of blind shear reconstruction on low-noise galaxies, several times better than any previous method.« less

  9. Gradient recovery in adaptive finite element methods for parabolic problems

    E-Print Network [OSTI]

    Lakkis, Omar

    2009-01-01

    We derive energy-norm aposteriori error bounds, using gradient recovery (ZZ) estimators to control the spatial error, for fully discrete schemes for the linear heat equation. This appears to be the first completely rigorous derivation of ZZ estimators for fully discrete schemes for evolution problems, without any restrictive assumption on the timestep size. An essential tool for the analysis is the elliptic reconstruction technique. Our theoretical results are backed with extensive numerical experimentation aimed at (a) testing the practical sharpness and asymptotic behaviour of the error estimator against the error, and (b) deriving an adaptive method based on our estimators. An extra novelty provided is an implementation of a coarsening error "preindicator", with a complete implementation guide in ALBERTA.

  10. Coherent structures in ion temperature gradient turbulence-zonal flow

    SciTech Connect (OSTI)

    Singh, Rameswar; Singh, R.; Kaw, P.; Gürcan, Ö. D.; Diamond, P. H.

    2014-10-15

    Nonlinear stationary structure formation in the coupled ion temperature gradient (ITG)-zonal flow system is investigated. The ITG turbulence is described by a wave-kinetic equation for the action density of the ITG mode, and the longer scale zonal mode is described by a dynamic equation for the m?=?n?=?0 component of the potential. Two populations of trapped and untrapped drift wave trajectories are shown to exist in a moving frame of reference. This novel effect leads to the formation of nonlinear stationary structures. It is shown that the ITG turbulence can self-consistently sustain coherent, radially propagating modulation envelope structures such as solitons, shocks, and nonlinear wave trains.

  11. DNA translocation through nanopores with salt gradients: The role of osmotic flow

    E-Print Network [OSTI]

    Hatlo, Marius M; van Roij, René

    2010-01-01

    Recent experiments of translocation of double stranded DNA through nanopores [M. Wanunu et al. Nature Nanotech. 5, 160 (2010)] reveal that the DNA capture rate can be significantly influenced by a salt gradient across the pore. We show that osmotic flow combined with electrophoresis can quantitatively explain the experimental data on the capture rate. The osmotic flow is induced by the salt gradient across the nanopore, and can be the dominant mechanism for DNA translocation through nanopores with a salt gradient.

  12. Mineral density volume gradients in normal and diseased human tissues

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

    Djomehri, Sabra I.; Candell, Susan; Case, Thomas; Browning, Alyssa; Marshall, Grayson W.; Yun, Wenbing; Lau, S. H.; Webb, Samuel; Ho, Sunita P.; Aikawa, Elena

    2015-04-09

    Clinical computed tomography provides a single mineral density (MD) value for heterogeneous calcified tissues containing early and late stage pathologic formations. The novel aspect of this study is that, it extends current quantitative methods of mapping mineral density gradients to three dimensions, discretizes early and late mineralized stages, identifies elemental distribution in discretized volumes, and correlates measured MD with respective calcium (Ca) to phosphorus (P) and Ca to zinc (Zn) elemental ratios. To accomplish this, MD variations identified using polychromatic radiation from a high resolution micro-computed tomography (micro-CT) benchtop unit were correlated with elemental mapping obtained from a microprobe X-raymore »fluorescence (XRF) using synchrotron monochromatic radiation. Digital segmentation of tomograms from normal and diseased tissues (N=5 per group; 40-60 year old males) contained significant mineral density variations (enamel: 2820-3095mg/cc, bone: 570-1415mg/cc, cementum: 1240-1340mg/cc, dentin: 1480-1590mg/cc, cementum affected by periodontitis: 1100-1220mg/cc, hypomineralized carious dentin: 345-1450mg/cc, hypermineralized carious dentin: 1815-2740mg/cc, and dental calculus: 1290-1770mg/cc). A plausible linear correlation between segmented MD volumes and elemental ratios within these volumes was established, and Ca/P ratios for dentin (1.49), hypomineralized dentin (0.32-0.46), cementum (1.51), and bone (1.68) were observed. Furthermore, varying Ca/Zn ratios were distinguished in adapted compared to normal tissues, such as in bone (855-2765) and in cementum (595-990), highlighting Zn as an influential element in prompting observed adaptive properties. Hence, results provide insights on mineral density gradients with elemental concentrations and elemental footprints that in turn could aid in elucidating mechanistic processes for pathologic formations.« less

  13. Sources of stress gradients in electrodeposited Ni MEMS.

    SciTech Connect (OSTI)

    Hearne, Sean Joseph; Floro, Jerrold Anthony; Dyck, Christopher William

    2004-06-01

    The ability of future integrated metal-semiconductor micro-systems such as RF MEMS to perform highly complex functions will depend on developing freestanding metal structures that offer improved conductivity and reflectivity over polysilicon structures. For example, metal-based RF MEMS technology could replace the bulky RF system presently used in communications, navigation, and avionics systems. However, stress gradients that induce warpage of active components have prevented the implementation of this technology. Figure 1, is an interference micrograph image of a series of cantilever beams fabricated from electrodeposited Ni. The curvature in the beams was the result of stress gradients intrinsic to the electrodeposition process. To study the sources of the stress in electrodeposition of Ni we have incorporated a wafer curvature based stress sensor, the multibeam optical stress sensor, into an electrodeposition cell. We have determined that there are two regions of stress induced by electrodepositing Ni from a sulfamate-based bath (Fig 2). The stress evolution during the first region, 0-1000{angstrom}, was determined to be dependent only on the substrate material (Au vs. Cu), whereas the stress evolution during the second region, >1000{angstrom}, was highly dependent on the deposition conditions. In this region, the stress varied from +0.5 GPa to -0.5GPa, depending solely on the deposition rate. We examined four likely sources for the compressive intrinsic stress, i.e. reduction in tensile stress, and determined that only the adatom diffusion into grain boundaries model of Sheldon, et al. could account for the observed compressive stress. In the presentation, we shall discuss the compressive stress generation mechanisms considered and the ramifications of these results on fabrication of electrodeposited Ni for MEMS applications.

  14. Effect of RF Gradient upon the Performance of the Wisconsin SRF Electron Gun

    SciTech Connect (OSTI)

    Bosch, Robert; Legg, Robert A.

    2013-12-01

    The performance of the Wisconsin 200-MHz SRF electron gun is simulated for several values of the RF gradient. Bunches with charge of 200 pC are modeled for the case where emittance compensation is completed during post-acceleration to 85 MeV in a TESLA module. We first perform simulations in which the initial bunch radius is optimal for the design gradient of 41 MV/m. We then optimize the radius as a function of RF gradient to improve the performance for low gradients.

  15. Constraints on the Cosmic-Ray Density Gradient Beyond the Solar...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Constraints on the Cosmic-Ray Density Gradient Beyond the Solar Circle From Fermi Gamma-Ray Observations of the Third Galactic Quadrant Citation Details...

  16. Assessment of temperature gradients in multianvil assemblies using spinel layer growth kinetics

    E-Print Network [OSTI]

    van Westrenen, Wim

    Assessment of temperature gradients in multianvil assemblies using spinel layer growth kinetics Wim Geophysical Laboratory and Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad

  17. Gradient symplectic algorithms for solving the radial Schrdinger equation Siu A. China

    E-Print Network [OSTI]

    Chin, Siu A.

    Gradient symplectic algorithms for solving the radial Schrödinger equation Siu A. China and Petr for their excellent conservation properties. The class of gradient symplectic algorithms is particularly suited. 69, 161 1993 for decomposing time-ordered operators, these algorithms can be easily applied

  18. Gradient flow and IR fixed point in SU(2) with Nf=8 flavors

    E-Print Network [OSTI]

    Viljami Leino; Tuomas Karavirta; Jarno Rantaharju; Teemu Rantalaiho; Kari Rummukainen; Joni M. Suorsa; Kimmo Tuominen

    2015-11-11

    We study the running of the coupling in SU(2) gauge theory with 8 massless fundamental representation fermion flavours, using the gradient flow method with the Schr\\"odinger functional boundary conditions. Gradient flow allows us to measure robust continuum limit for the step scaling function. The results show a clear indication of infrared fixed point consistent with perturbation theory.

  19. Fast Gradient-Descent Methods for Temporal-Difference Learning with Linear Function Approximation

    E-Print Network [OSTI]

    Szepesvari, Csaba

    Fast Gradient-Descent Methods for Temporal-Difference Learning with Linear Function Approximation with both linear function ap- proximation and off-policy training, and whose complexity scales only linearly requirements. 1. Motivation Temporal-difference methods based on gradient descent and linear function

  20. Fluctuation estimates for sub-quadratic gradient field actions David Brydges and Thomas Spencer

    E-Print Network [OSTI]

    Brydges, David

    Fluctuation estimates for sub-quadratic gradient field actions David Brydges and Thomas Spencer) Fluctuation estimates for sub-quadratic gradient field actions David Brydges1 and Thomas Spencer2 1 Department://dx.doi.org/10.1063/1.4747194] Dedicated to Elliott Lieb on the occasion of his 80th birthday The theory

  1. Mobility of large woody debris (LWD) jams in a low gradient channel Joanna C. Curran

    E-Print Network [OSTI]

    Curran, Joanna C.

    Mobility of large woody debris (LWD) jams in a low gradient channel Joanna C. Curran University debris Morphodynamics Wood jams Mobility Mobility of large woody debris (LWD) in low gradient channels is an important but often overlooked transport process. The majority of studies on LWD have focused on its role

  2. Polymer Brushes Patterned with Micrometer-Scale Chemical Gradients Using Laminar Co-Flow

    E-Print Network [OSTI]

    Braun, Paul

    Polymer Brushes Patterned with Micrometer-Scale Chemical Gradients Using Laminar Co-Flow Hyung as narrow as 5 m was created by controlling these parameters. The chemical gradient by laminar co validates the numerical procedures established in this study. Flow of multiple laminar streams of reactive

  3. A COMBINED VARIABLE METRIC -CONJUGATE GRADIENT ALGORITHM FOR A CLASS OF LARGE SCALE UNCONSTRAINED MINIMIZATION

    E-Print Network [OSTI]

    Oren, Shmuel S.

    A COMBINED VARIABLE METRIC - CONJUGATE GRADIENT ALGORITHM FOR A CLASS OF LARGE SCALE UNCONSTRAINED, California Abstract An algorithm is being presented for a special class of unconstrained minimization that is updated by the Rank One update, using gradients obtained in the preceeding steps. Two classes of problems

  4. Stem respiration in tropical forests along an elevation gradient in the Amazon and Andes

    E-Print Network [OSTI]

    Malhi, Yadvinder

    Stem respiration in tropical forests along an elevation gradient in the Amazon and Andes A M A N D metabolism, resulting in the release of carbon dioxide as a by-product. Little is known of how autotrophic respiration components vary across environmental gradients, particularly in tropical ecosystems. Here, we

  5. Intra--modality Image Registration using Gradients Mutawarra Hussain and Ela Claridge

    E-Print Network [OSTI]

    Claridge, Ela

    Intra--modality Image Registration using Gradients Mutawarra Hussain and Ela Claridge School--subject volumetric images has been achieved by using the variance of gradient ratios (VGR) technique. This technique intensity provides functional information on the metabolism of the region to be studied. The temporal

  6. Eddy currents in a gradient coil, modeled as circular loops of strips

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    Eddy currents in a gradient coil, modeled as circular loops of strips J.M.B. Kroot, S.J.L. van to induction, eddy currents occur, resulting in a so-called edge-effect. Higher frequencies cause stronger edge by a gradient coil induces eddy currents in the conducting structures. The eddy currents cause perturbations

  7. Seasonal Changes in Bacterial and Archaeal Gene Expression Patterns across Salinity Gradients in the

    E-Print Network [OSTI]

    their metabolic activities, microbial populations mediate the impact of high gradient regions on ecologicalSeasonal Changes in Bacterial and Archaeal Gene Expression Patterns across Salinity Gradients in nitrogen and carbon metabolism in the CRCM. Initial experiments with the environmental microarrays were

  8. Determination and modeling of the 3-D gradient refractive indices in crystalline lenses

    E-Print Network [OSTI]

    Chan, Derek Y C

    Determination and modeling of the 3-D gradient refractive indices in crystalline lenses Derek Y. C gradient refractive-index profiles in crystalline lenses is proposed. The input data are derivedfrom 2 crystalline lenses.2 This method is based on measuring the total refraction suffered by a light beam

  9. Production of stream habitat gradients by montane watersheds: hypothesis tests based on

    E-Print Network [OSTI]

    that lotic communities are structured by the quality and quantity of energy inputs to a streamProduction of stream habitat gradients by montane watersheds: hypothesis tests based on spatially of mountain watersheds interact to cause gradients in three stream attributes: baseflow stream widths, total

  10. Free-space microwave focusing by a negative-index gradient lens T. Driscolla

    E-Print Network [OSTI]

    Nemat-Nasser, Sia

    Free-space microwave focusing by a negative-index gradient lens T. Driscolla and D. N. Basov gradient-index lens with an index of refraction ranging from -2.67 edge to -0.97 center . Experimentally technology which offers significant design, mechanical, and cost advantages over other microwave lens

  11. SECOND GENERATION HIGH GRADIENT QUADRUPOLES FOR THE LHC INTERACTION REGIONS1

    E-Print Network [OSTI]

    Large Hadron Collider Program

    SECOND GENERATION HIGH GRADIENT QUADRUPOLES FOR THE LHC INTERACTION REGIONS1 T. Sen, J. Strait-gradient Nb3Sn quadrupoles, suitable for use in a second generation LHC interaction region, are presented generation of low-beta quadrupoles for the LHC IR inner triplets based on NbTi superconductor is being

  12. Water transport inside a single-walled carbon nanotube driven by temperature gradient

    E-Print Network [OSTI]

    Maruyama, Shigeo

    Water transport inside a single-walled carbon nanotube driven by temperature gradient J. Shiomi that the water cluster is transported with the average acceleration proportional to the temperature gradient of the confined water is sufficient to realize the transport. Particularly for the system with hydrophobic

  13. Spatially addressable design of gradient index structures through spatial light modulator based holographic lithography

    SciTech Connect (OSTI)

    Ohlinger, Kris; Lutkenhaus, Jeff [Department of Physics, University of North Texas, Denton, Texas 76203 (United States); Arigong, Bayaner; Zhang, Hualiang [Department of Electrical Engineering, University of North Texas, Denton, Texas 76203 (United States); Lin, Yuankun, E-mail: yuankun.lin@unt.edu [Department of Physics, University of North Texas, Denton, Texas 76203 (United States); Department of Electrical Engineering, University of North Texas, Denton, Texas 76203 (United States)

    2013-12-07

    In this paper, we present an achievable gradient refractive index in bi-continuous holographic structures that are formed through five-beam interference. We further present a theoretic approach for the realization of gradient index devices by engineering the phases of the interfering beams with a pixelated spatial light modulator. As an example, the design concept of a gradient index Luneburg lens is verified through full-wave electromagnetic simulations. These five beams with desired phases can be generated through programming gray level super-cells in a diffractive spatial light modulator. As a proof-of-concept, gradient index structures are demonstrated using synthesized and gradient phase patterns displayed in the spatial light modulator.

  14. Gradient flow and scale setting on MILC HISQ ensembles

    E-Print Network [OSTI]

    MILC Collaboration; A. Bazavov; C. Bernard; N. Brown; C. DeTar; J. Foley; Steven Gottlieb; U. M. Heller; J. Komijani; J. Laiho; L. Levkova; R. L. Sugar; D. Toussaint; R. S. Van de Water

    2015-03-24

    We report on a scale determination with gradient-flow techniques on the $N_f=2+1+1$ HISQ ensembles generated by the MILC collaboration. The ensembles include four lattice spacings, ranging from approximately 0.15 to 0.06 fm, and both physical and unphysical values of the quark masses. The scales $\\sqrt{t_0}/a$ and $w_0/a$ and their tree-level improvements, $\\sqrt{t_{0,{\\rm imp}}}$ and $w_{0,{\\rm imp}}$, are computed on each ensemble using Symanzik flow and the cloverleaf definition of the energy density $E$. Using a combination of continuum chiral perturbation theory and a Taylor-series ansatz for the lattice-spacing and strong-coupling dependence, the results are simultaneously extrapolated to the continuum and interpolated to physical quark masses. We determine the scales $\\sqrt{t_0} = 0.1416({}_{-5}^{+8})$ fm and $w_0 = 0.1717({}_{-11}^{+12})$ fm, where the errors are sums, in quadrature, of statistical and all systematic errors. The precision of $w_0$ and $\\sqrt{t_0}$ is comparable to or more precise than the best previous estimates, respectively. We also find the continuum mass-dependence of $w_0$ that will be useful for estimating the scales of other ensembles. We also estimate the integrated autocorrelation length of $\\langle E(t) \\rangle$. For long flow times, the autocorrelation length of $\\langle E \\rangle$ appears to be comparable to or smaller than that of the topological charge.

  15. Analysis Code for High Gradient Dielectric Insulator Surface Breakdown

    SciTech Connect (OSTI)

    Ives, Robert Lawrence [Calabazas Creek Research, Inc.; Verboncoeur, John [University of California - Berkeley; Aldan, Manuel [University of California, Berkeley

    2010-05-30

    High voltage (HV) insulators are critical components in high-energy, accelerator and pulsed power systems that drive diverse applications in the national security, nuclear weapons science, defense and industrial arenas. In these systems, the insulator may separate vacuum/non-vacuum regions or conductors with high electrical field gradients. These insulators will often fail at electric fields over an order of magnitude lower than their intrinsic dielectric strength due to flashover at the dielectric interface. Decades of studies have produced a wealth of information on fundamental processes and mechanisms important for flashover initiation, but only for relatively simple insulator configurations in controlled environments. Accelerator and pulsed power system designers are faced with applying the fundamental knowledge to complex, operational devices with escalating HV requirements. Designers are forced to rely on “best practices” and expensive prototype testing, providing boundaries for successful operation. However, the safety margin is difficult to estimate, and system design must be very conservative for situations where testing is not practicable, or replacement of failed parts is disruptive or expensive. The Phase I program demonstrated the feasibility of developing an advanced code for modeling insulator breakdown. Such a code would be of great interest for a number of applications, including high energy physics, microwave source development, fusion sciences, and other research and industrial applications using high voltage devices.

  16. Gradient flow and scale setting on MILC HISQ ensembles

    E-Print Network [OSTI]

    Bazavov, A; Brown, N; DeTar, C; Foley, J; Gottlieb, Steven; Heller, U M; Komijani, J; Laiho, J; Levkova, L; Sugar, R L; Toussaint, D; Van de Water, R S

    2015-01-01

    We report on a scale determination with gradient-flow techniques on the $N_f=2+1+1$ HISQ ensembles generated by the MILC collaboration. The ensembles include four lattice spacings, ranging from approximately 0.15 to 0.06 fm, and both physical and unphysical values of the quark masses. The scales $\\sqrt{t_0}/a$ and $w_0/a$ and their tree-level improvements, $\\sqrt{t_{0,{\\rm imp}}}$ and $w_{0,{\\rm imp}}$, are computed on each ensemble using Symanzik flow and the cloverleaf definition of the energy density $E$. Using a combination of continuum chiral perturbation theory and a Taylor-series ansatz for the lattice-spacing and strong-coupling dependence, the results are simultaneously extrapolated to the continuum and interpolated to physical quark masses. We determine the scales $\\sqrt{t_0} = 0.1416({}_{-5}^{+8})$ fm and $w_0 = 0.1717({}_{-11}^{+12})$ fm, where the errors are sums, in quadrature, of statistical and all systematic errors. The precision of $w_0$ and $\\sqrt{t_0}$ is comparable to or more precise than...

  17. Exploration geothermal gradient drilling, Platanares, Honduras, Central America

    SciTech Connect (OSTI)

    Goff, S.J.; Laughlin, A.W.; Ruefenacht, H.D.; Goff, F.E.; Heiken, G.; Ramos, N.

    1988-01-01

    This paper is a review and summary of the core drilling operations component of the Honduras Geothermal Resource Development Project at the Platanares geothermal prospect in Honduras, Central America. Three intermediate depth (428 to 679 m) coreholes are the first continuously cored geothermal exploration boreholes in Honduras. These coring operations are part of the Central America Energy Resource Project (CAERP) effort funded by the Agency for International Development (AID) and implemented by the Los Alamos National Laboratory (Los Alamos) in cooperation with the Empresa Nacional de Energia Electrica (ENEE) and the United States Geological Survey (USGS). This report emphasizes coring operations with reference to the stratigraphy, thermal gradient, and flow test data of the boreholes. The primary objectives of this coring effort were (1) to obtain quantitative information on the temperature distribution as a function of depth, (2) to recover fluids associated with the geothermal reservoir, (3) to recover 75% or better core from the subsurface rock units, and (4) to drill into the subsurface rock as deeply as possible in order to get information on potential reservoir rocks, fracture density, permeabilities, and alteration histories of the rock units beneath the site. The three exploration coreholes drilled to depths of 650, 428 and 679 m, respectively, encountered several hot water entries. Coring operations and associated testing began in mid-October 1986 and were completed at the end of June 1987.

  18. Microsoft PowerPoint - temp.ppt

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on darkMicroorganismsnowReportJ.Next Quarter-CenturyFutureSummary

  19. C:\WINDOWS\Temp\SOCpdf.PDF

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room News PublicationsAudits &Bradbury Science Museum6 Shares ofDOE/WIPP-97-2238A

  20. Gradient optimization of analytic controls: the route to high accuracy quantum optimal control

    E-Print Network [OSTI]

    Shai Machnes; David J. Tannor; Frank K. Wilhelm; Elie Assémat

    2015-07-15

    We argue that quantum optimal control can and should be done with analytic control functions, in the vast majority of applications. First, we show that discretizing continuous control functions as piecewise-constant functions prevents high accuracy optimization at reasonable computational costs. Second, we argue that the number of control parameters required is on-par with the dimension of the object manipulated, and therefore one may choose parametrization by other considerations, e.g. experimental suitability and the potential for physical insight into the optimized pulse. Third, we note that optimal control algorithms which make use of the gradient of the goal function with respect to control parameters are generally faster and reach higher final accuracies than non gradient-based methods. Thus, if the gradient can be efficiently computed, it should be used. Fourth, we present a novel way of computing the gradient based on an equation of motion for the gradient, which we evolve in time by the Taylor expansion of the propagator. This allows one to calculate any physically relevant analytic controls to arbitrarily high precision. The combination of the above techniques is GOAT (Gradient Optimization of Analytic conTrols) - gradient-based optimal control for analytic control functions, utilizing exact evolution in time of the derivative of the propagator with respect to arbitrary control parameters.

  1. Vitality and chemistry of roots of red spruce in forest floors of stands with a gradient of soil

    E-Print Network [OSTI]

    David, Mark B.

    Vitality and chemistry of roots of red spruce in forest floors of stands with a gradient of soil Al) dominated by red spruce and with a gradient of forest floor exchangeable Al/Ca ratios. Root vitality

  2. Pararell Electron temperature and Density Gradients measured in the JET Mk I Divertor using Thermal Helium Beams

    E-Print Network [OSTI]

    Pararell Electron temperature and Density Gradients measured in the JET Mk I Divertor using Thermal Helium Beams

  3. An Elementary Extension of Korn's First Inequality to H(Curl) motivated by Gradient Plasticity with Plastic Spin

    E-Print Network [OSTI]

    Patrizio Neff; Dirk Pauly; Karl-Josef Witsch

    2011-06-30

    We prove a Korn-type inequality for tensor fields without gradient structure, which generalizes Korn's first inequality.

  4. A gradient system on the quantum information space that realizes the Karmarkar flow for linear programming

    E-Print Network [OSTI]

    Yoshio Uwano; Hiromi Yuya

    2008-07-25

    In the paper of Uwano [Czech. J. of Phys., vol.56, pp.1311-1316 (2006)], a gradient system is found on the space of density matrices endowed with the quantum SLD Fisher metric (to be referred to as the quantum information space) that realizes a generalization of a gradient system on the space of multinomial distributions studied by Nakamura [Japan J. Indust. Appl. Math., vol.10, pp.179-189 (1993)]. On motived by those papers, the present paper aims to construct a gradient system on the quantum information space that realizes the Karmarkar flow, the continuous limit of the Karmarkar projective scaling algorithm for linear programming.

  5. Proton Gradient Regulation 5-Mediated Cyclic Electron Flow under ATP-or Redox-Limited Conditions: A Study of

    E-Print Network [OSTI]

    Proton Gradient Regulation 5-Mediated Cyclic Electron Flow under ATP- or Redox-Limited Conditions.K.N.) The Chlamydomonas reinhardtii proton gradient regulation5 (Crpgr5) mutant shows phenotypic and functional traits discriminate two pathways for CEF and determine their maximum electron flow rates. The PGR5/proton gradient

  6. Motivation Gradient Method Stochastic Subgradient Finite-Sum Methods Non-Smooth Objectives Modern Convex Optimization Methods for

    E-Print Network [OSTI]

    Marlin, Benjamin

    Motivation Gradient Method Stochastic Subgradient Finite-Sum Methods Non-Smooth Objectives Modern) International Conference on Machine Learning Peter Richt´arik and Mark Schmidt July 2015 #12;Motivation Gradient. Not gigabytes, but terabytes or petabytes (and beyond). #12;Motivation Gradient Method Stochastic Subgradient

  7. Stoichiometry and grazer community composition over gradients of light, nutrients, and predation risk

    E-Print Network [OSTI]

    Hall, Spencer R.; Leibold, Mathew A.; Lytle, David A.; Smith, Val H.

    2004-08-01

    mesocosms (cattle tanks) by creating gradients of resource supply and predation risk, to which we added diverse assemblages of algal producer and zooplankton grazer species. We then characterized the end-point composition of grazer assemblages and quantity...

  8. Stoichiometry and planktonic grazer composition over gradients of light, nutrients, and predation risk

    E-Print Network [OSTI]

    Hall, Spencer R.; Leibold, Mathew A.; Lytle, David A.; Smith, Val H.

    2004-01-01

    mesocosms (cattle tanks) by creating gradients of resource supply and predation risk, to which we added diverse assemblages of algal producer and zooplankton grazer species. We then characterized the end-point composition of grazer assemblages and quantity...

  9. Observation of a Critical Gradient Threshold for Electron Temperature Fluctuations in the DIII-D Tokamak

    E-Print Network [OSTI]

    White, Anne E.

    A critical gradient threshold has been observed for the first time in a systematic, controlled experiment for a locally measured turbulent quantity in the core of a confined high-temperature plasma. In an experiment in the ...

  10. Local genomic adaptation of coral reef-associated microbiomes to gradients of natural variability

    E-Print Network [OSTI]

    Smith, Jennifer E.

    Local genomic adaptation of coral reef-associated microbiomes to gradients of natural variability to have specific microbiomes. In contrast, local environmental factors are predicted to select for specific metabolic pathways in microbes. To reconcile these two predictions, we hypothesized

  11. Evaluation of residual stress gradients in ductile cast iron using critical refracted longitudinal (Lcr) wave technique 

    E-Print Network [OSTI]

    Pfluger, Ron Atlan

    1995-01-01

    Critically refracted longitudinal (LCR) waves have been investigated as a possible technique for the evaluation of the residual stress gradients present in ductile iron castings. Residual stresses are likely to develop in ductile cast iron during...

  12. Quadrature Rotating-Frame Gradient Fields for Ultra-Low Field Nuclear Magnetic Resonance and Imaging

    E-Print Network [OSTI]

    Bouchard, Louis-Serge

    2005-01-01

    Frame Gradient Fields For Ultra-Low Field Nuclear Magneticslow, as in the limit of ultra-low ?elds. In the ?rst case,B. Slice selection in ultra-low ?elds We ?rst examine the

  13. ENERGY SCAVENGING BASED ON TRANSIENT THERMAL GRADIENTS: APPLICATION TO STRUCTURAL HEALTH MONITORING OF AIRCRAFTS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ENERGY SCAVENGING BASED ON TRANSIENT THERMAL GRADIENTS: APPLICATION TO STRUCTURAL HEALTH MONITORING health monitoring 1. INTRODUCTION Aircraft in-service structural health monitoring (SHM) by wireless be considered in the context of aircraft structural health monitoring, we will restrict ourselves

  14. Studies of the superconducting traveling wave cavity for high gradient LINAC

    E-Print Network [OSTI]

    Avrakhov, Pavel; Kanareykin, Alexei; Solyak, Nikolay; Yakovlev, Vyacheslav P

    2015-01-01

    Use of a traveling wave (TW) accelerating structure with a small phase advance per cell instead of standing wave may provide a significant increase of accelerating gradient in a superconducting linear accelerator. The TW section achieves an accelerating gradient 1.2-1.4 larger than TESLA-shaped standing wave cavities for the same surface electric and magnetic fields. Recent tests of an L-band single-cell cavity with a waveguide feedback demonstrated an accelerating gradient comparable to the gradient in a single-cell ILC-type cavity from the same manufacturer. This article presents the next stage of the 3- cell TW resonance ring development which will be tested in the traveling wave regime. The main simulation results of the microphonics and Lorentz Force Detuning (LFD) are also considered.

  15. On a class of strain gradient plasticity theories : formulation and numerical implementation

    E-Print Network [OSTI]

    Lele, Suvrat Pratapsinh

    2008-01-01

    This study develops strain-gradient theories for isotropic and crystal plasticity. The following four theories were developed and numerically implemented: * A one-dimensional theory to understand the basic nature of strain ...

  16. Gradient Projection Anti-windup Scheme on Constrained Planar LTI Systems

    E-Print Network [OSTI]

    Teo, Justin

    2010-03-15

    The gradient projection anti-windup (GPAW) scheme was recently proposed as an anti-windup method for nonlinear multi-input-multi-output systems/controllers, the solution of which was recognized as a largely open problem ...

  17. Osteochondral Tissue Engineering for the TMJ Condyle Using a Novel Gradient Scaffold

    E-Print Network [OSTI]

    Singh, Milind

    2008-10-22

    sustains the greatest damage in TMDs. The objective of this thesis was to characterize the condylar cartilage biomechanics, and to explore novel routes to fabricate integrated gradient-based osteochondral constructs. Pioneering efforts were made toward...

  18. Future applications of the Yang-Mills gradient flow in lattice QCD

    E-Print Network [OSTI]

    Martin Lüscher

    2013-08-26

    The Yang--Mills gradient flow has many interesting applications in lattice QCD. In this talk, some recent and possible future uses of the flow are discussed, emphasizing the underlying theoretical concepts rather than any computational aspects.

  19. Accounting for the Change in the Gradient: Health Inequality among Infants

    E-Print Network [OSTI]

    Lin, Wanchuan

    2006-01-01

    Accounting for the Change in the Gradient: Health InequalityLine Working Paper Series Accounting for the Change in thethe most important factor in accounting for the closing gap.

  20. ORGANIC MATTER DISTRIBUTION AND TURNOVER ALONG A GRADIENT FROM FOREST TO TIDAL CREEK

    E-Print Network [OSTI]

    Lawrence, Deborah

    i ORGANIC MATTER DISTRIBUTION AND TURNOVER ALONG A GRADIENT FROM FOREST TO TIDAL CREEK A Thesis. A nested plot design was used to harvest vegetation, obtain soil cores, and collect quantitative data... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .18 Qualitative Vegetation Analysis

  1. A gradient optimization method for efficient design of three-dimensional deformation processes

    E-Print Network [OSTI]

    Zabaras, Nicholas J.

    A gradient optimization method for efficient design of three-dimensional deformation processes Swagato Acharjee and Nicholas Zabaras Materials Process Design and Control Laboratory, Sibley School processes. The optimization is based on the continuum sensitivity method (CSM). CSM involves differentiation

  2. On the relationship between water-flux and hydraulic gradient for unsaturated and saturated clay

    E-Print Network [OSTI]

    Liu, H.H.

    2014-01-01

    Threshold gradient for water flow in clay systems. Soil.Darcy’s law for the flow of water in soils. Soil Science 93:1970. Saturated flow of water through clay loam subsoil

  3. High-Gradient Tests of the Single-Cell SC Cavity with a Feedback Waveguide

    SciTech Connect (OSTI)

    Yakovlev, V.; Solyak, N.; Wu, G.; Ge, M.; Gonin, I.; Khabiboulline, T.; Ozelis, J.; Rowe, A. [Fermilab, Batavia, IL 60510 (United States); Avrakhov, P.; Kanareykin, A. [Euclid TechLabs, LLC, Solon, Ohio 44139 (United States); Rathke, J. [AES, Medford, NY 11763 (United States)

    2010-11-04

    Use of a superconducting (SC) traveling-wave accelerating (STWA) structure with a small phase advance per cell, rather than a standing-wave structure, may provide a significant increase in the accelerating gradient in the ILC linac [1]. For the same surface electric and magnetic fields, the STWA achieves an accelerating gradient 1.2 larger than TESLA-like standing-wave cavities. In addition, the STWA allows longer acceleration cavities, reducing the number of gaps between them. However, the STWA structure requires a SC feedback waveguide to return the few hundreds of MW of circulating RF power from the structure output to the structure input. A test single-cell cavity with feedback was designed and manufactured to demonstrate the possibility of proper processing to achieve a high accelerating gradient. The first results of high-gradient tests of a prototype 1.3 GHz single-cell cavity with feedback waveguide will be presented.

  4. Highly Parallel Magnetic Resonance Imaging with a Fourth Gradient Channel for Compensation of RF Phase Patterns 

    E-Print Network [OSTI]

    Bosshard, John 1983-

    2012-08-20

    A fourth gradient channel was implemented to provide slice dependent RF coil phase compensation for arrays in dual-sided or "sandwich" configurations. The use of highly parallel arrays for single echo acquisition magnetic resonance imaging allows...

  5. Effect of Density Gradient Centrifugation on Quality and Recovery Rate of Equine Sperm 

    E-Print Network [OSTI]

    Edmond, Ann J.

    2010-07-14

    Density gradient centrifugation of sperm is a common assisted-reproduction procedure in humans used to improve semen quality. The technique allows sperm separation based on their isopycnic points. Sperm with morphologic abnormalities are often more...

  6. Critical gradient for internal erosion in earthen d ams : a comparative analysis of two predictive methodologies

    E-Print Network [OSTI]

    Donohue, Catherine, M. Eng. Massachusetts Institute of Technology

    2013-01-01

    Minimizing the uncertainty in predicting the critical gradient of a dam (i.e. the critical reservoir pool level) is important during the risk analysis of dams. Uncertainty leads to inexact relative risk in portfolio ...

  7. Top hole drilling with dual gradient technology to control shallow hazards 

    E-Print Network [OSTI]

    Elieff, Brandee Anastacia Marie

    2006-10-30

    , shallow gas and shallow water flows. These negative aspects of "Pump and Dump" are in addition to the environmental impact, high drilling fluid (mud) costs and limited mud options. Dual gradient technology offers a closed system, which improves drilling...

  8. Resonance in Optimal Perturbation Evolution. Part II: Effects of a Nonzero Mean PV Gradient

    E-Print Network [OSTI]

    de Vries, Hylke

    Resonance in Optimal Perturbation Evolution. Part II: Effects of a Nonzero Mean PV Gradient H. DE (PV) perturbations and the surface edge wave plays a key role in the surface dynamics (e.g. De Vries

  9. Simultaneous measurement of gravity acceleration and gravity gradient with an atom interferometer

    SciTech Connect (OSTI)

    Sorrentino, F.; Lien, Y.-H.; Rosi, G.; Tino, G. M.; Bertoldi, A.; Bodart, Q.; Cacciapuoti, L.; Angelis, M. de; Prevedelli, M.

    2012-09-10

    We demonstrate a method to measure the gravitational acceleration with a dual cloud atom interferometer; the use of simultaneous atom interferometers reduces the effect of seismic noise on the gravity measurement. At the same time, the apparatus is capable of accurate measurements of the vertical gravity gradient. The ability to determine the gravity acceleration and gravity gradient simultaneously and with the same instrument opens interesting perspectives in geophysical applications.

  10. Computation of Growth Rates and Threshold of the Electromagnetic Electron Temperature Gradient Modes in Tokamaks

    E-Print Network [OSTI]

    Varun Tangri

    2013-01-29

    In this manuscript, eigenvalues of the Electron Temperature Gradient (ETG) modes and Ion Temperature Gradient (ITG) modes are determined numerically using Hermite and Sinc differentiation matrices based methods. It is shown that these methods are very useful for the computation of growth rates and threshold of the ETG and ITG modes. The total number of accurately computed eigenvalues for the modes have also been computed. The ideas developed here are also of relevance to other modes that use Ballooning formalism.

  11. Computation of Growth Rates and Threshold of the Electromagnetic Electron Temperature Gradient Modes in Tokamaks

    E-Print Network [OSTI]

    Tangri, Varun

    2013-01-01

    In this manuscript, eigenvalues of the Electron Temperature Gradient (ETG) modes and Ion Temperature Gradient (ITG) modes are determined numerically using Hermite and Sinc differentiation matrices based methods. It is shown that these methods are very useful for the computation of growth rates and threshold of the ETG and ITG modes. The total number of accurately computed eigenvalues for the modes have also been computed. The ideas developed here are also of relevance to other modes that use Ballooning formalism.

  12. Magneto-Seebeck effect in spin-valve with in-plane thermal gradient

    SciTech Connect (OSTI)

    Jain, S. Bose, A. Palkar, V. R. Tulapurkar, A. A.; Lam, D. D. Suzuki, Y.; Sharma, H. Tomy, C. V.

    2014-12-15

    We present measurements of magneto-Seebeck effect on a spin valve with in-plane thermal gradient. We measured open circuit voltage and short circuit current by applying a temperature gradient across a spin valve stack, where one of the ferromagnetic layers is pinned. We found a clear hysteresis in these two quantities as a function of magnetic field. From these measurements, the magneto-Seebeck effect was found to be same as magneto-resistance effect.

  13. Thomas-BMT equation generalized to electric dipole moments and field gradients

    E-Print Network [OSTI]

    Metodiev, Eric M

    2015-01-01

    An expression is presented for the relativistic equations of motion, including field gradients, of a particle and its spin with electric and magnetic dipole moments aligned along the spin axis. An electromagnetic duality transformation is used to generalize a Thomas-BMT equation with gradient terms. Corrections to particle dynamics in storage rings for precision $(g-2)$ and electric dipole moment measurements are calculated, and applications to precision particle tracking programs are considered.

  14. Effect of pressure gradient on the drag reduction performance of two and three dimensional riblets 

    E-Print Network [OSTI]

    Hall, Aaron Chenault

    1991-01-01

    EFFECT OF PRESSURE GRADIENT ON THE DRAG REDUCTION PERFORMANCE OF TWO AND THREE DIMENSIONAL RIBLETS A Thesis by AARON CHENAULT HALL Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE December 1991 Major Subject: Aerospace Engineering EFFECT OF PRESSURE GRADIENT ON THE DRAG REDUCTION PERFORMANCE OF TWO AND THREE DIMENSIONAL RIBLETS A Thesis by AARON CHENAULT HALL Approved as to style and content by...

  15. Technical and economic feasibility of a Thermal Gradient Utilization Cycle (TGUC) power plant 

    E-Print Network [OSTI]

    Raiji, Ashok

    1980-01-01

    be used to exploit solar, geothermal or other low grade energy sources is to utilize the temperature gradient that naturally occurs in the atmosphere to provide the temperature differential for a power production cycle. This concept known... low grade energy (geothermal, solar oonds, etc. ) to vaporize the working fluid. The following sections describe the operating principles of the TGUC, the digital computer model, the Atmospheric Thermal Gradient Cycle, the parametric study...

  16. Intraarterial Pressure Gradients After Randomized Angioplasty or Stenting of Iliac Artery Lesions

    SciTech Connect (OSTI)

    Tetteroo, Eric; Haaring, Cees [Department of Radiology, Room E.01.132, University Hospital Utrecht, Heidelberglaan 100, NL-3584 CX Utrecht (Netherlands); Graaf, Yolanda van der [Department of Clinical Epidemiology, University Hospital Utrecht, Heidelberglaan 100, NL-3584 CX Utrecht (Netherlands); Schaik, Jan P.J. van; Engelen, A.D. van; Mali, Willem P.T.M. [Department of Radiology, Room E.01.132, University Hospital Utrecht, Heidelberglaan 100, NL-3584 CX Utrecht (Netherlands)

    1996-11-15

    Purpose: To determine initial technical results of percutaneous transluminal angioplasty (PTA) and stent procedures in the iliac artery, mean intraarterial pressure gradients were recorded before and after each procedure. Methods: We randomly assigned 213 patients with typical intermittent claudication to primary stent placement (n= 107) or primary PTA (n= 106), with subsequent stenting in the case of a residual mean pressure gradient of > 10 mmHg (n= 45). Eligibility criteria included angiographic iliac artery stenosis (> 50% diameter reduction) and/or a peak systolic velocity ratio > 2.5 on duplex examination. Mean intraarterial pressures were simultaneously recorded above and below the lesion, at rest and also during vasodilatation in the case of a resting gradient {<=} 10 mmHg. Results: Pressure gradients in the primary stent group were 14.9 {+-} 10.4 mmHg before and 2.9 {+-} 3.5 mmHg after stenting. Pressure gradients in the primary PTA group were 17.3 {+-} 11.3 mmHg pre-PTA, 4.2 {+-} 5.4 mmHg post-PTA, and 2.5 {+-} 2.8 mmHg after selective stenting. Compared with primary stent placement, PTA plus selective stent placement avoided application of a stent in 63% (86/137) of cases, resulting in a considerable cost saving. Conclusion: Technical results of primary stenting and PTA plus selective stenting are similar in terms of residual pressure gradients.

  17. Integrating 3D seismic curvature and curvature gradient attributes for fracture characterization: Methodologies and interpretational implications

    SciTech Connect (OSTI)

    Gao, Dengliang

    2013-03-01

    In 3D seismic interpretation, curvature is a popular attribute that depicts the geometry of seismic reflectors and has been widely used to detect faults in the subsurface; however, it provides only part of the solutions to subsurface structure analysis. This study extends the curvature algorithm to a new curvature gradient algorithm, and integrates both algorithms for fracture detection using a 3D seismic test data set over Teapot Dome (Wyoming). In fractured reservoirs at Teapot Dome known to be formed by tectonic folding and faulting, curvature helps define the crestal portion of the reservoirs that is associated with strong seismic amplitude and high oil productivity. In contrast, curvature gradient helps better define the regional northwest-trending and the cross-regional northeast-trending lineaments that are associated with weak seismic amplitude and low oil productivity. In concert with previous reports from image logs, cores, and outcrops, the current study based on an integrated seismic curvature and curvature gradient analysis suggests that curvature might help define areas of enhanced potential to form tensile fractures, whereas curvature gradient might help define zones of enhanced potential to develop shear fractures. In certain fractured reservoirs such as at Teapot Dome where faulting and fault-related folding contribute dominantly to the formation and evolution of fractures, curvature and curvature gradient attributes can be potentially applied to differentiate fracture mode, to predict fracture intensity and orientation, to detect fracture volume and connectivity, and to model fracture networks.

  18. Vertical two-phase flow regimes and pressure gradients: Effect of viscosity

    SciTech Connect (OSTI)

    Da Hlaing, Nan; Sirivat, Anuvat; Siemanond, Kitipat [The Petroleum and Petrochemical College, Chulalongkorn University, Soi Chula 12, Phayathai Road, Pathumwan, Bangkok 10330 (Thailand); Wilkes, James O. [Department of Chemical Engineering, The University of Michigan, Ann Arbor, MI 48109-2136 (United States)

    2007-05-15

    The effect of liquid viscosity on the flow regimes and the corresponding pressure gradients along the vertical two-phase flow was investigated. Experiment was carried out in a vertical transparent tube of 0.019 m in diameter and 3 m in length and the pressure gradients were measured by a U-tube manometer. Water and a 50 vol.% glycerol solution were used as the working fluids whose kinematic viscosities were 0.85 x 10{sup -6} and 4.0 x 10{sup -6} m{sup 2}/s, respectively. In our air-liquid annular two-phase flow, the liquid film of various thicknesses flowed adjacent to the wall and the gas phase flowed at the center of the tube. The superficial air velocity, j{sub air}, was varied between 0.0021 and 58.7 m/s and the superficial liquid velocity, j{sub liquid}, was varied between 0 and 0.1053 m/s. In the bubble, the slug and the slug-churn flow regimes, the pressure gradients decreased with increasing Reynolds number. But in the annular and the mist flow regimes, pressure gradients increased with increasing Reynolds number. Finally, the experimentally measured pressure gradient values were compared and are in good agreement with the theoretical values. (author)

  19. Design Studies of Nb3Sn High-Gradient Quadrupole Models for LARP

    SciTech Connect (OSTI)

    Andreev, Nikolai; Caspi, Shlomo; Dietderich, Daniel; Ferracin, Paolo; Ghosh, Arup; Kashikhin, Vadim; Lietzke, Al; Novitski, Igor; Zlobin, Alexander; McInturff, Alfred; Sabbi, GianLuca

    2007-06-01

    Insertion quadrupoles with large aperture and high gradient are required to achieve the luminosity upgrade goal of 10{sup 35} cm{sup -2} s{sup -1} at the Large Hadron Collider (LHC). In 2004, the US Department of Energy established the LHC Accelerator Research Program (LARP) to develop a technology base for the upgrade. Nb{sub 3}Sn conductor is required in order to operate at high field and with sufficient temperature margin. We report here on the conceptual design studies of a series of 1 m long 'High-gradient Quadrupoles' (HQ) that will explore the magnet performance limits in terms of peak fields, forces and stresses. The HQ design is expected to provide coil peak fields of more than 15 T, corresponding to gradients above 300 T/m in a 90 mm bore. Conductor requirements, magnetic, mechanical and quench protection issues for candidate HQ designs will be presented and discussed.

  20. Photon storage in Lambda-type optically dense atomic media. IV. Optimal control using gradient ascent

    E-Print Network [OSTI]

    Alexey V. Gorshkov; Tommaso Calarco; Mikhail D. Lukin; Anders S. Sorensen

    2008-04-07

    We use the numerical gradient ascent method from optimal control theory to extend efficient photon storage in Lambda-type media to previously inaccessible regimes and to provide simple intuitive explanations for our optimization techniques. In particular, by using gradient ascent to shape classical control pulses used to mediate photon storage, we open up the possibility of high efficiency photon storage in the non-adiabatic limit, in which analytical solutions to the equations of motion do not exist. This control shaping technique enables an order-of-magnitude increase in the bandwidth of the memory. We also demonstrate that the often discussed connection between time reversal and optimality in photon storage follows naturally from gradient ascent. Finally, we discuss the optimization of controlled reversible inhomogeneous broadening.

  1. The gas metallicity gradient and the star formation activity of disc galaxies

    E-Print Network [OSTI]

    Tissera, Patricia B; Sillero, Emanuel; Vilchez, Jose M

    2015-01-01

    We study oxygen abundance profiles of the gaseous disc components in simulated galaxies in a hierarchical universe. We analyse the disc metallicity gradients in relation to the stellar masses and star formation rates of the simulated galaxies. We find a trend for galaxies with low stellar masses to have steeper metallicity gradients than galaxies with high stellar masses at z ~0. We also detect that the gas-phase metallicity slopes and the specific star formation rate (sSFR) of our simulated disc galaxies are consistent with recently reported observations at z ~0. Simulated galaxies with high stellar masses reproduce the observed relationship at all analysed redshifts and have an increasing contribution of discs with positive metallicity slopes with increasing redshift. Simulated galaxies with low stellar masses a have larger fraction of negative metallicity gradients with increasing redshift. Simulated galaxies with positive or very negative metallicity slopes exhibit disturbed morphologies and/or have a clo...

  2. Gravity-Gradient Subtraction in 3rd Generation Underground Gravitational-Wave Detectors in Homogeneous Media

    E-Print Network [OSTI]

    Jan Harms; Riccardo DeSalvo; Steven Dorsher; Vuk Mandic

    2009-10-15

    In this paper, we develop a new approach to gravity-gradient noise subtraction for underground gravitational-wave detectors in homogeneous rock. The method is based on spatial harmonic expansions of seismic fields. It is shown that gravity-gradient noise produced by seismic fields from distant sources, stationary or non-stationary, can be calculated from seismic data measured locally at the test mass. Furthermore, the formula is applied to seismic fields from stationary local sources. It is found that gravity gradients from these fields can be subtracted using local seismic measurements. The results are confirmed numerically with a finite-element simulation. A new seismic-array design is proposed that provides the additional information about the seismic field required to ensure applicability of the approach to realistic scenarios even with inhomogeneous rock and non-stationary local sources.

  3. Millisecond ordering of block-copolymer films via photo-thermal gradients

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

    Majewski, Pawel W.; Yager, Kevin G.

    2015-03-12

    For the promise of self-assembly to be realized, processing techniques must be developed that simultaneously enable control of the nanoscale morphology, rapid assembly, and, ideally, the ability to pattern the nanostructure. Here, we demonstrate how photo-thermal gradients can be used to control the ordering of block-copolymer thin films. Highly localized laser heating leads to intense thermal gradients, which induce a thermophoretic force on morphological defects. This increases the ordering kinetics by at least 3 orders-of-magnitude, compared to conventional oven annealing. By simultaneously exploiting the thermal gradients to induce shear fields, we demonstrate uniaxial alignment of a block-copolymer film in lessmore »than a second. Finally, we provide examples of how control of the incident light-field can be used to generate prescribed configurations of block-copolymer nanoscale patterns.« less

  4. Summary report of working group 3: High gradient and laser-structure based acceleration

    SciTech Connect (OSTI)

    Solyak, N.; Cowan, B.M.; /Tech-X, Boulder

    2010-01-01

    The charge for the working group on high gradient and laser-structure based acceleration was to assess the current challenges involved in developing an advanced accelerator based on electromagnetic structures, and survey state-of-the-art methods to address those challenges. The topics of more than 50 presentations in the working group covered a very broad range of issues, from ideas, theoretical models and simulations, to design and manufacturing of accelerating structures and, finally, experimental results on obtaining extremely high accelerating gradients in structures from conventional microwave frequency range up to THz and laser frequencies. Workshop discussion topics included advances in the understanding of the physics of breakdown and other phenomena, limiting high gradient performance of accelerating structures. New results presented in this workshop demonstrated significant progress in the fields of conventional vacuum structure-based acceleration, dielectric wakefield acceleration, and laser-structure acceleration.

  5. Dynamics of Ion Temperature Gradient Turbulence and Transport with a Static Magnetic Island

    E-Print Network [OSTI]

    Izacard, Olivier; James, Spencer D; Brennan, Dylan P

    2015-01-01

    The quantification of the interaction mechanism between large-scale magnetohydrodynamics instabilities and small-scale drift-wave microturbulence is essential for predicting and optimizing the performance of magnetic confinement based fusion energy experiments. We report progress on understanding these interactions using both analytic theory and numerical simulation, with BOUT++ [B. Dudson et al., Comput. Phys. Comm. 180, 1467 (2009)] used to evolve simple five-field fluid models in a sheared slab geometry. This work focuses upon understanding the dynamics of the ion temperature gradient instability in the presence of a background static magnetic island in a weakly electromagnetic two-dimensional five-field model as key parameters such as ion temperature gradient, magnetic gradients and static magnetic island size are varied. The simulation results are then used to calculate the effective turbulent transport coefficient (i.e. resistivity) that is compared against classical coefficient. As part of this work, t...

  6. Finite ballooning angle effects on ion temperature gradient driven mode in gyrokinetic flux tube simulations

    SciTech Connect (OSTI)

    Singh, Rameswar, E-mail: rameswar.singh@lpp.polytechnique.fr [Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 (India) [Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 (India); Laboratoire de Physique des Plasmas, Ecole Polytechnique, Route de Saclay, 91128 Palaiseau Cedex (France); Brunner, S. [CRPP, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland)] [CRPP, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland); Ganesh, R. [Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 (India)] [Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 (India); Jenko, F. [Max-Planck-Institut fur Plasmaphysik, EURATOM Association, D-85748 Garching (Germany)] [Max-Planck-Institut fur Plasmaphysik, EURATOM Association, D-85748 Garching (Germany)

    2014-03-15

    This paper presents effects of finite ballooning angles on linear ion temperature gradient (ITG) driven mode and associated heat and momentum flux in Gyrokinetic flux tube simulation GENE. It is found that zero ballooning angle is not always the one at which the linear growth rate is maximum. The ITG mode acquires a short wavelength (SW) branch (k{sub ?}?{sub i}?>?1) when growth rates maximized over all ballooning angles are considered. However, the SW branch disappears on reducing temperature gradient showing characteristics of zero ballooning angle SWITG in case of extremely high temperature gradient. Associated heat flux is even with respect to ballooning angle and maximizes at nonzero ballooning angle while the parallel momentum flux is odd with respect to the ballooning angle.

  7. Study of thermal-gradient-induced migration of brine inclusions in salt. Final report

    SciTech Connect (OSTI)

    Olander, D.R.

    1984-08-01

    Natural salt deposits, which are being considered for high-level waste disposal, contain a small volume fraction of water in the form of brine inclusions distributed throughout the salt. Radioactive decay heating of the nuclear wastes will impose a temperature gradient on the surrounding salt which mobilizes the brine inclusions. Inclusions filled completely with brine (the all-liquid inclusions) migrate up the temperature gradient and eventually accumulate brine near the buried waste forms. The brine may slowly corrode or degrade the waste forms, which is undesirable. Therefore it is important to consider the migration of brine inclusions in salt under imposed temperature gradients to properly evaluate the performance of a future salt repository for nuclear wastes. The migration velocities of the inclusions were found to be dependent on temperature, temperature gradient, and inclusion shape and size. The velocities were also dictated by the interfacial mass transfer resistance at brine/solid interface. This interfacial resistance depends on the dislocation density in the crystal, which in turn, depends on the axial compressive loading of the crystal. At low axial loads, the dependence between the velocity and temperature gradient is nonlinear. At high axial loads, the interfacial resistance is reduced and the migration velocity depends linearly on the temperature gradient. All-liquid inclusions filled with mixed brines were also studied. For gas-liquid inclusions, helium, air and argon were compared. Migration studies were also conducted on single crystallites of natural salt as well as in polycrystalline natural salt samples. The behavior of the inclusions at large-ange grain boundaries was observed.

  8. Coexistence of colossal stress and texture gradients in sputter deposited nanocrystalline ultra-thin metal films

    SciTech Connect (OSTI)

    Kuru, Yener; Welzel, Udo; Mittemeijer, Eric J.

    2014-12-01

    This paper demonstrates experimentally that ultra-thin, nanocrystalline films can exhibit coexisting colossal stress and texture depth gradients. Their quantitative determination is possible by X-ray diffraction experiments. Whereas a uniform texture by itself is known to generally cause curvature in so-called sin{sup 2}? plots, it is shown that the combined action of texture and stress gradients provides a separate source of curvature in sin{sup 2}? plots (i.e., even in cases where a uniform texture does not induce such curvature). On this basis, the texture and stress depth profiles of a nanocrystalline, ultra-thin (50?nm) tungsten film could be determined.

  9. Non-preconditioned conjugate gradient on cell and FPCA-based hybrid supercomputer nodes

    SciTech Connect (OSTI)

    Dubois, David H; Dubois, Andrew J; Boorman, Thomas M; Connor, Carolyn M

    2009-03-10

    This work presents a detailed implementation of a double precision, Non-Preconditioned, Conjugate Gradient algorithm on a Roadrunner heterogeneous supercomputer node. These nodes utilize the Cell Broadband Engine Architecture{trademark} in conjunction with x86 Opteron{trademark} processors from AMD. We implement a common Conjugate Gradient algorithm, on a variety of systems, to compare and contrast performance. Implementation results are presented for the Roadrunner hybrid supercomputer, SRC Computers, Inc. MAPStation SRC-6 FPGA enhanced hybrid supercomputer, and AMD Opteron only. In all hybrid implementations wall clock time is measured, including all transfer overhead and compute timings.

  10. Non-preconditioned conjugate gradient on cell and FPGA based hybrid supercomputer nodes

    SciTech Connect (OSTI)

    Dubois, David H; Dubois, Andrew J; Boorman, Thomas M; Connor, Carolyn M

    2009-01-01

    This work presents a detailed implementation of a double precision, non-preconditioned, Conjugate Gradient algorithm on a Roadrunner heterogeneous supercomputer node. These nodes utilize the Cell Broadband Engine Architecture{sup TM} in conjunction with x86 Opteron{sup TM} processors from AMD. We implement a common Conjugate Gradient algorithm, on a variety of systems, to compare and contrast performance. Implementation results are presented for the Roadrunner hybrid supercomputer, SRC Computers, Inc. MAPStation SRC-6 FPGA enhanced hybrid supercomputer, and AMD Opteron only. In all hybrid implementations wall clock time is measured, including all transfer overhead and compute timings.

  11. High gradient magnetic separation of iron oxide minerals from soil clays 

    E-Print Network [OSTI]

    Schulze, Darrell Gene

    1977-01-01

    steel wool, placed in a strong magnetic field (1. 6 Tesla), provides the magnetic field and magnetic field gradients necessary to trap weakly magnetic, clay size particles flowing through the filter as a dilute suspension in pH 10. 5 Na C03 solution...- magnetic particles. 2. There must be magnetic field gradients across the volume of the particles for magnetic attraction and trapping to occur. A magnetic field on the order of 1-2 Tesla produced by an electro- magnet is necessary to magnetize...

  12. An Enhanced Nonlinear Critical Gradient for Electron Turbulent Transport due to Reversed Magnetic Shear

    SciTech Connect (OSTI)

    Peterson, J. L.; Hammet, G. W.; Mikkelsen, D. R.; Yuh, H. Y.; Candy, J.; Guttenfelder, W.; Kaye, S. M.; LeBlanc, B.

    2011-05-11

    The first nonlinear gyrokinetic simulations of electron internal transport barriers (e-ITBs) in the National Spherical Torus Experiment show that reversed magnetic shear can suppress thermal transport by increasing the nonlinear critical gradient for electron-temperature-gradient-driven turbulence to three times its linear critical value. An interesting feature of this turbulence is non- linearly driven off-midplane radial streamers. This work reinforces the experimental observation that magnetic shear is likely an effective way of triggering and sustaining e-ITBs in magnetic fusion devices.

  13. Effects of Temperature Gradients and Heat Fluxes on High-Temperature Oxidation

    SciTech Connect (OSTI)

    Holcomb, G.R.

    2008-04-01

    The effects of a temperature gradient and heat flux on point defect diffusion in protective oxide scales were examined. Irreversible thermodynamics were used to expand Fick’s first law of diffusion to include a heat-flux term—a Soret effect. Oxidation kinetics were developed for the oxidation of cobalt and of nickel doped with chromium. Research is described to verify the effects of a heat flux by oxidizing pure cobalt in a temperature gradient at 900 °C, and comparing the kinetics to isothermal oxidation. No evidence of a heat flux effect was found.

  14. Plasma size and power scaling of ion temperature gradient driven turbulence

    SciTech Connect (OSTI)

    Idomura, Yasuhiro [Japan Atomic Energy Agency, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8587 (Japan)] [Japan Atomic Energy Agency, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8587 (Japan); Nakata, Motoki [Japan Atomic Energy Agency, Obuchi-Omotedate 2-166, Rokkasho, Kamikita, Aomori 039-3212 (Japan)] [Japan Atomic Energy Agency, Obuchi-Omotedate 2-166, Rokkasho, Kamikita, Aomori 039-3212 (Japan)

    2014-02-15

    The transport scaling with respect to plasma size and heating power is studied for ion temperature gradient driven turbulence using a fixed-flux full-f gyrokinetic Eulerian code. It is found that when heating power is scaled with plasma size, the ion heat diffusivity increases with plasma size in a local limit regime, where fixed-gradient ?f simulations predict a gyro-Bohm scaling. In the local limit regime, the transport scaling is strongly affected by the stiffness of ion temperature profiles, which is related to the power degradation of confinement.

  15. OPEN POSITION: Entomological Taxonomist and Research Associate Improving our understanding of the elevational biodiversity gradient of Rocky Mountain National Park

    E-Print Network [OSTI]

    Ishida, Yuko

    of the elevational biodiversity gradient of Rocky Mountain National Park: arthropod diversity and conservation Range, including from Rocky Mountain National Park. The taxonomic groups of most interest include

  16. Environmental regulation of carbon isotope composition and crassulacean acid metabolism in three plant communities along a water availability gradient

    E-Print Network [OSTI]

    2010-01-01

    communities along a water availability gradient M. Fernandawith decreasing water availability. Overall, variation inrelated to water and light availability and CAM appeared to

  17. Change in biomass of benthic and planktonic algae along a disturbance gradient for 24 Great

    E-Print Network [OSTI]

    McMaster University

    Change in biomass of benthic and planktonic algae along a disturbance gradient for 24 Great Lakes. The PC1 site score was significantly related to both periphyton and phytoplankton biomass, respectively accounted for 18% of the variation in epiphyton biomass. Periphytic and epiphytic biomass were negatively

  18. Policy Gradient Planning for Environmental Decision Making with Existing Mark Crowley and David Poole

    E-Print Network [OSTI]

    Poole, David

    Policy Gradient Planning for Environmental Decision Making with Existing Simulators Mark Crowley policies for sustainable harvest planning of a forest. Introduction In many environmental and natural and David Poole University of British Columbia crowley@cs.ubc.ca poole@cs.ubc.ca Abstract In environmental

  19. Global Convergence of An Iterative Gradient Algorithm for The Nash Equilibrium in An

    E-Print Network [OSTI]

    Pavel, Lacra

    Global Convergence of An Iterative Gradient Algorithm for The Nash Equilibrium in An Extended OSNR constraints within a Nash game framework. In optical wavelength-division multiplexed (WDM) networks, all as the optical link capacity constraint. In our previous work in [1], we proposed an extended OSNR Nash game

  20. Gradient Sensitivity to Within-Category Variation in Words and Syllables Bob McMurray

    E-Print Network [OSTI]

    Makous, Walter

    that during online spoken word recognition, lexical competitors are activated in proportion to their continuous distance from a category boundary. This gradient processing may allow listeners to anticipate a continuous and contextually varying signal into discrete and contextually invariant units such as phonemes

  1. Classification of remotely sensed imagery using stochastic gradient boosting as a refinement of classification tree analysis

    E-Print Network [OSTI]

    Lawrence, Rick L.

    trees) are increasingly being used for analysis and classification of remotely sensed digital imageryClassification of remotely sensed imagery using stochastic gradient boosting as a refinement of classification tree analysis Rick Lawrencea,*, Andrew Bunna , Scott Powellb , Michael Zambona a Department

  2. Modeling proton intensity gradients and radiation dose equivalents in the inner

    E-Print Network [OSTI]

    Pringle, James "Jamie"

    Modeling proton intensity gradients and radiation dose equivalents in the inner heliosphere using exposure in IP space. In this paper, we utilize EMMREM to study the radial dependence of proton peak crossfield diffusion at large radial distances. Our results show that radial dependencies of proton peak

  3. Existence theory for finite-strain crystal plasticity with gradient regularization

    E-Print Network [OSTI]

    Mielke, Alexander

    Existence theory for finite-strain crystal plasticity with gradient regularization Alexander Mielke combine the formal ideas for single-crystal plasticity from [OrR99, Mie03] with the recent analytical and the plastic tensor P, which is driven by the plastic slip strain rates pj. We allow for self-hardening as well

  4. Wax diffusivity under given thermal gradient: a mathematical model , A. Fasano

    E-Print Network [OSTI]

    Primicerio, Mario

    Wax diffusivity under given thermal gradient: a mathematical model S. Correra , A. Fasano , L. Fusi , M. Primicerio , F. Rosso Abstract In this paper we describe how to obtain wax diffusivity and solubility in a saturated crude oil using the measurements of solid wax deposit in the experimental apparatus

  5. Offshore Coastal Wind Speed Gradients: issues for the design and development of large offshore windfarms

    E-Print Network [OSTI]

    Pryor, Sara C.

    -situ and remote sensing data from offshore wind farms in Denmark, are used to examine both horizontal and vertical the area of the wind farm appear to be small and negligible. 1. INTRODUCTION As large offshore wind farmsOffshore Coastal Wind Speed Gradients: issues for the design and development of large offshore

  6. Droplet motion with phase change in a temperature gradient Akira Onuki and Kentaro Kanatani

    E-Print Network [OSTI]

    2005 We examine the droplet motion in one-component fluids in a small temperature gradient by solving changes the hydro- dynamic flow around the droplet. As a result, the temperature becomes almost the Reynolds number Re=vgR/ gR3 1- / / 2 is small. Here = / is the exterior kinematic viscosity. As another

  7. Kirchhoff prestack depth migration in velocity models with and without vertical gradients

    E-Print Network [OSTI]

    Cerveny, Vlastislav

    Kirchhoff prestack depth migration in velocity models with and without vertical gradients-mail: bucha@seis.karlov.mff.cuni.cz Summary The Kirchhoff prestack depth migration is used to calculate. The bottom layer is isotropic and homogeneous. We apply the Kirchhoff prestack depth migration to both

  8. Kirchhoff prestack depth migration in velocity models with and without gradients: Comparison

    E-Print Network [OSTI]

    Cerveny, Vlastislav

    Kirchhoff prestack depth migration in velocity models with and without gradients: Comparison@seis.karlov.mff.cuni.cz Summary We use the Kirchhoff prestack depth migration to calculate migrated sections in simple anisotropic is isotropic and homogeneous. We apply the Kirchhoff prestack depth migration to both heterogeneous

  9. MPC for Wind Power Gradients --Utilizing Forecasts, Rotor Inertia, and Central Energy Storage

    E-Print Network [OSTI]

    MPC for Wind Power Gradients -- Utilizing Forecasts, Rotor Inertia, and Central Energy Storage the control of a wind power plant, possibly consisting of many individual wind turbines. The goal. INTRODUCTION Today, wind power is the most important renewable energy source. For the years to come, many

  10. Habitat change and the scale of habitat selection: shifting gradients used by coexisting Arctic rodents

    E-Print Network [OSTI]

    Morris, Douglas W.

    of association with the structure and composition of habitat. Abundant collared lemmings abandoned stations where altered habitat characteristics caused a shift to new locations along the wet-to-dry gradient convincing case that habitat loss and change thus represent the most pressing issue for the conservation

  11. A Novel Gradient Induced Main Subject Segmentation Algorithm for Digital Still Cameras

    E-Print Network [OSTI]

    Evans, Brian L.

    A Novel Gradient Induced Main Subject Segmentation Algorithm for Digital Still Cameras Serene, it is often rst necessary to detect and seg- ment the main subject. We propose an detection and segmentation, an auto-focus lter rst puts the main subject in focus and takes a picture. Then, we open the shutter

  12. HELIUM CONTAMINATION FROM THE PROGENITOR STARS OF PLANETARY NEBULAE: THE HE/H RADIAL GRADIENT AND

    E-Print Network [OSTI]

    Maciel, Walter Junqueira

    HELIUM CONTAMINATION FROM THE PROGENITOR STARS OF PLANETARY NEBULAE: THE HE/H RADIAL GRADIENT of a sample of disk planetary nebulae (PN). First, an application of corrections owing to the contamination such as 4 He on the basis of these objects, it is necessary to take into account the He contamination

  13. Faunal responses to oxygen gradients on the Pakistan margin: A comparison of foraminiferans, macrofauna and megafauna

    E-Print Network [OSTI]

    Levin, Lisa

    Faunal responses to oxygen gradients on the Pakistan margin: A comparison of foraminiferans Oxygen minimum zone Benthos Arabian Sea Biodiversity Deep sea a b s t r a c t The Pakistan Margin where oxygen levels were lowest. The rarity of larger animals between 300 and 700 m on the Pakistan

  14. Hydroecological factors governing surface water flow on a low-gradient floodplain

    E-Print Network [OSTI]

    to flow reductions associated with flood control. We measured flow velocity, water depth, and wind with the square of water surface slope and the fourth power of stem diameter, decreases in direct proportionHydroecological factors governing surface water flow on a low-gradient floodplain Judson W. Harvey

  15. Temperature-Aware MPSoC Scheduling for Reducing Hot Spots and Gradients

    E-Print Network [OSTI]

    Coskun, Ayse

    to manufacture reliable systems while meeting energy and performance constraints. In this work, we solve the task, San Diego Abstract-- Thermal hot spots and temperature gradients on the die need to be minimized is optimal. We compare our technique against optimal scheduling methods for energy minimization, energy

  16. Systematic variation of bedrock channel gradients in the central Oregon Coast Range: implications for rock uplift

    E-Print Network [OSTI]

    Roering, Joshua J.

    for rock uplift and shallow landsliding Jeremiah S. Kobor*, Joshua J. Roering Department of Geological rock uplift for several million years, did not experience Pleistocene glaciation, boasts a relatively variability in bedrock channel gradients resulting from differential rock uplift or other sources. Consistent

  17. Gradient texture unit coding for texture analysis Chein-I Chang, FELLOW SPIE

    E-Print Network [OSTI]

    Chang, Chein-I

    Gradient texture unit coding for texture analysis Chein-I Chang, FELLOW SPIE Yuan Chen University features to capture in image characteristics. A recent texture unit-based texture spectrum approach, referred to as texture unit coding (TUC) developed by Wang and He has shown promise in texture

  18. Phenotypic Plasticity of Leaf Shape along a Temperature Gradient in Acer rubrum

    E-Print Network [OSTI]

    Royer, Dana

    Phenotypic Plasticity of Leaf Shape along a Temperature Gradient in Acer rubrum Dana L. Royer1 plasticity and genetic determination can be important for understanding how plants respond to environmental change. However, little is known about the plastic response of leaf teeth and leaf dissection

  19. Results of geothermal gradient core hole TCB-1, Tecuamburro volcano geothermal site, Guatemala, Central America

    SciTech Connect (OSTI)

    Adams, A.I.; Chipera, S.; Counce, D.; Gardner, J.; Goff, S.; Goff, F.; Heiken, G.; Laughlin, A.W.; Musgrave, J.; Trujillo, P.E. Jr. (Los Alamos National Lab., NM (United States)); Aycinena, S.; Martinelli, L. (Swissboring Overseas Corp. Ltd., Guatemala City (Guatemala)); Castaneda, O.; Revolorio, M.; Roldan, A. (Unidad de Desarrollo Geotermico, Guatemala City (Guatemala). Inst. Nacional de Electrificacion); D

    1992-02-01

    Results of geological, volcanological, hydrogeochemical, and geophysical field studies conducted in 1988 and 1989 at the Tecuamburro volcano geothermal site in Guatemala indicated that there is a substantial shallow heat source beneath the area of youngest volcanism. To obtain information on subsurface temperatures and temperature gradients, stratigraphy, hydrothermal alteration, fracturing, and possible inflows of hydrothermal fluids, a geothermal gradient core hole (TCB-1) was drilled to 808 m low on the northern flank of the Tecuamburro volcano Complex, 300 km south of a 300-m-diameter phreatic crater, Laguna Ixpaco, dated at 2,910 years. Gases from acid-sulfate springs near Laguna Ixpaco consistently yield maximum estimated subsurface temperatures of 250--300{degrees}C. The temperature versus depth curve from TCB-1 does not show isothermal conditions and the calculated thermal gradients from 500--800 m is 230{degrees}C/km. Bottom hole temperature is 238{degrees}C. Calculated heat flow values are nearly 9 heat flow units (HFU). The integration of results from the TCB-1 gradient core hole with results from field studies provides strong evidence that the Tecuamburro area holds great promise for containing a commercial geothermal resource.

  20. A complete implementation of the conjugate gradient algorithm on a reconfigurable supercomputer

    SciTech Connect (OSTI)

    Dubois, David H [Los Alamos National Laboratory; Dubois, Andrew J [Los Alamos National Laboratory; Connor, Carolyn M [Los Alamos National Laboratory; Boorman, Thomas M [Los Alamos National Laboratory; Poole, Stephen W [ORNL

    2008-01-01

    The conjugate gradient is a prominent iterative method for solving systems of sparse linear equations. Large-scale scientific applications often utilize a conjugate gradient solver at their computational core. In this paper we present a field programmable gate array (FPGA) based implementation of a double precision, non-preconditioned, conjugate gradient solver for fmite-element or finite-difference methods. OUf work utilizes the SRC Computers, Inc. MAPStation hardware platform along with the 'Carte' software programming environment to ease the programming workload when working with the hybrid (CPUIFPGA) environment. The implementation is designed to handle large sparse matrices of up to order N x N where N <= 116,394, with up to 7 non-zero, 64-bit elements per sparse row. This implementation utilizes an optimized sparse matrix-vector multiply operation which is critical for obtaining high performance. Direct parallel implementations of loop unrolling and loop fusion are utilized to extract performance from the various vector/matrix operations. Rather than utilize the FPGA devices as function off-load accelerators, our implementation uses the FPGAs to implement the core conjugate gradient algorithm. Measured run-time performance data is presented comparing the FPGA implementation to a software-only version showing that the FPGA can outperform processors running up to 30x the clock rate. In conclusion we take a look at the new SRC-7 system and estimate the performance of this algorithm on that architecture.

  1. Critical gradients and plasma flows in the edge plasma of Alcator C-Mod

    SciTech Connect (OSTI)

    LaBombard, B.; Hughes, J. W.; Smick, N.; Marr, K.; McDermott, R.; Reinke, M.; Greenwald, M.; Lipschultz, B.; Terry, J. L.; Whyte, D. G.; Graf, A.; Zweben, S. J.

    2008-05-15

    Recent experiments have led to a fundamental shift in our view of edge transport physics; transport near the last-closed flux surface may be more appropriately described in terms of a critical gradient phenomenon rather than a diffusive and/or convective paradigm. Edge pressure gradients, normalized by the square of the poloidal magnetic field strength, appear invariant in plasmas with the same normalized collisionality, despite vastly different currents and magnetic fields--a behavior that connects with first-principles electromagnetic plasma turbulence simulations. Near-sonic scrape-off layer (SOL) flows impose a cocurrent rotation boundary condition on the confined plasma when Bx{nabla}B points toward the active x-point, suggesting a link to the concomitant reduction in input power needed to attain high-confinement modes. Indeed, low-confinement mode plasmas are found to attain higher edge pressure gradients in this configuration, independent of the direction of B, evidence that SOL flows may affect transport and 'critical gradient' values in the edge plasma.

  2. Cosmological constraints from the redshift dependence of the Alcock-Paczynski test: galaxy density gradient field

    SciTech Connect (OSTI)

    Li, Xiao-Dong; Park, Changbom; Forero-Romero, J. E.; Kim, Juhan E-mail: cbp@kias.re.kr E-mail: kjhan@kias.re.kr

    2014-12-01

    We propose a method based on the redshift dependence of the Alcock-Paczynski (AP) test to measure the expansion history of the universe. It uses the isotropy of the galaxy density gradient field to constrain cosmological parameters. If the density parameter ? {sub m} or the dark energy equation of state w are incorrectly chosen, the gradient field appears to be anisotropic with the degree of anisotropy varying with redshift. We use this effect to constrain the cosmological parameters governing the expansion history of the universe. Although redshift-space distortions (RSD) induced by galaxy peculiar velocities also produce anisotropies in the gradient field, these effects are close to uniform in magnitude over a large range of redshift. This makes the redshift variation of the gradient field anisotropy relatively insensitive to the RSD. By testing the method on mock surveys drawn from the Horizon Run 3 cosmological N-body simulations, we demonstrate that the cosmological parameters can be estimated without bias. Our method is complementary to the baryon acoustic oscillation or topology methods as it depends on D{sub AH} , the product of the angular diameter distance and the Hubble parameter.

  3. Development of high gradient laser wakefield accelerators towards nuclear detection applications at LBNL

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    compact systems. Laser-driven, plasma wakefield accelerators (LWFAs) [2] in use at LBNL provide high than conventional linacs, and confirms the anticipated scaling of laser driven accelerators to GeDevelopment of high gradient laser wakefield accelerators towards nuclear detection applications

  4. Dendroclimatic Response along a Moisture Gradient in the Southern Rocky Mountains 

    E-Print Network [OSTI]

    Young, Shelby Lynn

    2015-06-01

    the moisture gradient. Using tree-ring analysis, I found growth to be slower and more sensitive to climate at the low moisture distributional limit than elsewhere within the spatial distribution. Trees at this site were more impacted by the 1950s drought...

  5. Seasonal mass-balance gradients in Norway L.A. RASMUSSEN,1

    E-Print Network [OSTI]

    Rasmussen, L.A.

    Seasonal mass-balance gradients in Norway L.A. RASMUSSEN,1 L.M. ANDREASSEN2,3 1 Department of Earth, Norway 3 Department of Geosciences, University of Oslo, Blindern, NO-0316 Oslo, Norway ABSTRACT. Previously discovered regularity in vertical profiles of net balance, bnðzÞ, on ten glaciers in Norway also

  6. Land use and habitat gradients determine bird community diversity and abundance in suburban, rural

    E-Print Network [OSTI]

    Thomas, David D.

    Land use and habitat gradients determine bird community diversity and abundance in suburban, rural, with reserves slightly below rural. Although reserves were like rural lands in diversity of bird communities bird communities, but differed in grassland and savanna bird communities. The extensive rural forests

  7. A gradient flow approach to an evolution problem arising in superconductivity

    E-Print Network [OSTI]

    Serfaty, Sylvia

    A gradient flow approach to an evolution problem arising in superconductivity Luigi Ambrosio for the evolution of the vortex-density in a superconductor. We treat the case of a bounded domain where vortices in studying the following "mean-field model" (also called hydrodynamic limit) for superconductivity which

  8. Free Energy based Policy Gradients Evangelos A. Theodorou1, Jiri Najemnik2 , and Emo Todorov2

    E-Print Network [OSTI]

    Todorov, Emanuel

    Free Energy based Policy Gradients Evangelos A. Theodorou1, Jiri Najemnik2 , and Emo Todorov2 spaces and continuous time for free energy-like cost functions. The derivation is based on successive, we derive PGs for cost functions that have the form of free energy. Free energy functions appear

  9. Activated Charcoal Based Diffusive Gradients in Thin Films for in Situ Monitoring of Bisphenols in Waters

    E-Print Network [OSTI]

    Ma, Lena

    Activated Charcoal Based Diffusive Gradients in Thin Films for in Situ Monitoring of Bisphenols, Gainesville, Florida 32611, United States *S Supporting Information ABSTRACT: Widespread use of bisphenols monitoring of BPs in waters. Endocrine-disrupting chemicals, including bisphenols (BPs), are widely used

  10. Capacitive Mixing Power Production from Salinity Gradient Energy Enhanced through ExoelectrogenGenerated Ionic Currents

    E-Print Network [OSTI]

    Capacitive Mixing Power Production from Salinity Gradient Energy Enhanced through Exoelectrogen for an external power supply, the voltage window remains limited by the #12;3 3 membrane potential which used. #12;5 5 Fig. 2s: Steady state whole cell power density for three chamber microbial fuel

  11. Roadmaps using Gradient Extremal Paths Ioannis Filippidis and Kostas J. Kyriakopoulos

    E-Print Network [OSTI]

    Low, Steven H.

    Roadmaps using Gradient Extremal Paths Ioannis Filippidis and Kostas J. Kyriakopoulos Abstract-- This work proposes a motion planning method based on the construction of a roadmap connecting the critical methods due to local minima caused by concave obstacles. The roadmap is incre- mentally constructed

  12. Power Grid Analysis Using a Flexible Conjugate Gradient Algorithm with Sparsification

    E-Print Network [OSTI]

    Freund, Roland W.

    Power Grid Analysis Using a Flexible Conjugate Gradient Algorithm with Sparsification Peter power grid analysis. The algorithm allows changing preconditioners and sparsification of the search and sparsification. The algorithm is applied to a number of realistic power grid examples. I. INTRODUCTION The design

  13. Ammonium Bicarbonate Transport in Anion Exchange Membranes for Salinity Gradient Energy

    E-Print Network [OSTI]

    to address global energy needs, such as reverse electro- dialysis1-4 (RED), capacitive energy extraction are the predominant ions in many natural water sources.12 Thermolytic salts, such as aqueous ammonium bicarbonate (AmB), are being considered for salinity gradient energy production because these solutions permit closed

  14. Transient effective hydraulic conductivities under slowly and rapidly varying mean gradients in bounded three-

    E-Print Network [OSTI]

    Tartakovsky, Daniel M.

    Transient effective hydraulic conductivities under slowly and rapidly varying mean gradients it Darcian in real or transformed domains. Each such situation gives rise to an effective hydraulic-time. In this paper we develop first-order analytical expressions for effective hydraulic conductivity under three

  15. Molecular dynamics simulations of a chemical reaction; conditions for local equilibrium in a temperature gradient

    E-Print Network [OSTI]

    Kjelstrup, Signe

    Molecular dynamics simulations of a chemical reaction; conditions for local equilibrium have examined a simple chemical reaction in a temperature gradient; 2F $ F2. A mechanical model molecular dynamics simulations showed that the chemical reaction is in local thermodynamic as well

  16. Kramers' formula for chemical reactions in the context of Wasserstein gradient flows

    E-Print Network [OSTI]

    Michael Herrmann; Barbara Niethammer

    2010-11-05

    We derive Kramers' formula as singular limit of the Fokker-Planck equation with double-well potential. The convergence proof is based on the Rayleigh principle of the underlying Wasserstein gradient structure and complements a recent result by Peletier, Savar\\'e and Veneroni.

  17. Thermal lens elimination by gradient-reduced zone coupling of optical beams

    DOE Patents [OSTI]

    Page, Ralph H. (San Ramon, CA); Beach, Raymond J. (Livermore, CA)

    2000-01-01

    A thermal gradient-reduced-zone laser includes a laser medium and an optically transparent plate with an index of refraction that is less than the index of refraction of the laser medium. The pump face of the laser medium is bonded to a surface of the optically transparent member. Pump light is directed through the transparent plate to optically pump the solid state laser medium. Heat conduction is mainly through the surface of the laser medium where the heat is introduced by the pump light. Heat flows in a direction opposite to that of the pump light because the side of the laser medium that is opposite to that of the pump face is not in thermal contact with a conductor and thus there is no heat flux (and hence, no temperature gradient), thus producing a thermal gradient-reduced zone. A laser cavity is formed around the laser medium such that laser light oscillating within the laser cavity reflects by total-internal-reflection from the interface between the pump face and the optically transparent plate and enters and exits through a thermal gradient-reduced zone.

  18. Manufacture of gradient micro-structures of magnesium alloys using two stage extrusion dies

    SciTech Connect (OSTI)

    Hwang, Yeong-Maw; Huang, Tze-Hui [Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University, No. 70, Lien-Hai Rd., Kaohsiung, 804, Taiwan (China); Alexandrov, Sergei [Institute for Problems in Mechanics, Russian Academy of Sciences, Moscow (Russian Federation); Naimark, Oleg Borisovich [Institute of Continuous Media Mechanics, Russian Academy of Sciences, Perm (Russian Federation); Jeng, Yeau-Ren [Department of Mechanical Engineering and Advanced Institute of Manufacturing with High-tech Innovations, National Chung Cheng University, Ming-Hsiung, Chia-Yi 621, Taiwan (China)

    2013-12-16

    This paper aims to manufacture magnesium alloy metals with gradient micro-structures using hot extrusion process. The extrusion die was designed to have a straight channel part combined with a conical part. Materials pushed through this specially-designed die generate a non-uniform velocity distribution at cross sections inside the die and result in different strain and strain rate distributions. Accordingly, a gradient microstructure product can be obtained. Using the finite element analysis, the forming temperature, effective strain, and effective strain rate distributions at the die exit were firstly discussed for various inclination angles in the conical die. Then, hot extrusion experiments with a two stage die were conducted to obtain magnesium alloy products with gradient micro-structures. The effects of the inclination angle on the grain size distribution at cross sections of the products were also discussed. Using a die of an inclination angle of 15°, gradient micro-structures of the grain size decreasing gradually from 17 ?m at the center to 4 ?m at the edge of product were achieved.

  19. Cancer classification by gradient LDA technique using microarray gene expression data

    E-Print Network [OSTI]

    Cancer classification by gradient LDA technique using microarray gene expression data Alok Sharma a) Dimensionality reduction Cancer classification Feature selection Feature extraction a b s t r a c t Cancer techniques are applied for cancer classification, they face the small sample size (SSS) problem of gene

  20. Modeling Robustness Tradeoffs in Yeast Cell Polarization Induced by Spatial Gradients

    E-Print Network [OSTI]

    Chou, Ching-Shan; Nie, Qing; Yi, Tau-Mu

    2008-01-01

    Yi T-M, Chen S, Chou C-S, Nie Q (2007) Modeling yeast cellGradients Ching-Shan Chou 1 , Qing Nie 1. , Tau-Mu Yi 2. * 1Citation: Chou C-S, Nie Q, Yi T-M (2008) Modeling Robustness

  1. Joint two-dimensional DC resistivity and seismic travel time inversion with cross-gradients constraints

    E-Print Network [OSTI]

    Meju, Max

    Joint two-dimensional DC resistivity and seismic travel time inversion with cross to evaluate the structural features common to both methods. The cross-gradients function is incorporated method. The resultant iterative two-dimensional (2-D) joint inversion scheme is successfully applied

  2. Beryllium7 in soils and vegetation along an arid precipitation gradient in Owens Valley, California

    E-Print Network [OSTI]

    Elmore, Andrew J.

    Beryllium7 in soils and vegetation along an arid precipitation gradient in Owens Valley, California; revised 29 March 2011; accepted 1 April 2011; published 7 May 2011. [1] Beryllium7 is a potentially potential as a sediment tracer in desert environments. Beryllium7 in vegetation and the upper few cm of soil

  3. Quantification of ovarian cancer markers with integrated microfluidic concentration gradient and

    E-Print Network [OSTI]

    Brolo, Alexandre G.

    Quantification of ovarian cancer markers with integrated microfluidic concentration gradient and quantification of ovarian cancer markers. Calibration curves based on controlled concentrations of the analyte. The biosensors were first used to detect the immobilization of ovarian cancer marker antibodies, and subsequently

  4. Development of Ultra High Gradient and High Q{sub 0} Superconducting Radio Frequency Cavities

    SciTech Connect (OSTI)

    Geng, Rongli [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Clemens, William A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Follkie, James E. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Harris, Teena M. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Kushnick, Peter W. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Machie, Danny [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Martin, Robert E. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Palczewski, Ari D. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Perry, Era A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Slack, Gary L. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Williams, R. S. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Adolphsen, C. [SLAC, Menlo Park, California, (United States); Li, Z. [SLAC, Menlo Park, California, (United States); Hao, J. K. [Peking University, Beijing (China); Li, Y. M. [Peking University, Beijing (China); Liu, K. X. [Peking University, Beijing (China)

    2013-06-01

    We report on the recent progress at Jefferson Lab in developing ultra high gradient and high Q{sub 0} superconducting radio frequency (SRF) cavities for future SRF based machines. A new 1300 MHz 9-cell prototype cavity is being fabricated. This cavity has an optimized shape in terms of the ratio of the peak surface field (both magnetic and electric) to the acceleration gradient, hence the name low surface field (LSF) shape. The goal of the effort is to demonstrate an acceleration gradient of 50 MV/m with Q{sub 0} of 10{sup 10} at 2 K in a 9-cell SRF cavity. Fine-grain niobium material is used. Conventional forming, machining and electron beam welding method are used for cavity fabrication. New techniques are adopted to ensure repeatable, accurate and inexpensive fabrication of components and the full assembly. The completed cavity is to be first mechanically polished to a mirror-finish, a newly acquired in-house capability at JLab, followed by the proven ILC-style processing recipe established already at JLab. In parallel, new single-cell cavities made from large-grain niobium material are made to further advance the cavity treatment and processing procedures, aiming for the demonstration of an acceleration gradient of 50 MV/m with Q{sub 0} of 2?10{sup 10} at 2K.

  5. Neighborhood Analyses of Canopy Tree Competition along Environmental Gradients in New England Forests

    E-Print Network [OSTI]

    Uriarte, Maria

    RubensteinSchool of Environmentand Natural Resources, Universityof Vermont, 590 Main St., Burlington, Vermont, available at http://www.jstor.org/page/info/about/policies/terms.jsp. JSTOR's Terms and Conditions of Use of these cases, abundance was displaced to the more resource-poorend of the environmental gradient (either low

  6. Nordic Society Oikos Trophic Control across a Natural Productivity Gradient with Sap-Feeding Herbivores

    E-Print Network [OSTI]

    Uriarte, Maria

    Nordic Society Oikos Trophic Control across a Natural Productivity Gradient with Sap's Terms and Conditions of Use, available at http://www.jstor.org/page/info/about/policies/terms.jsp. JSTOR the discovery and use of these resources. For more information about JSTOR, please contact support

  7. Latitudinal gradients in sea ice and primary production determine Arctic seabird colony

    E-Print Network [OSTI]

    Laidre, Kristin L.

    -scale control on energy flux and primary and secondary production, ultimately reaching the top of the food chainLatitudinal gradients in sea ice and primary production determine Arctic seabird colony size Naturama, Dronningemaen 30, 5700 Svendborg, Denmark 4 Department of Arctic Environment, National

  8. Pulsed Gradient Spin Echo Nuclear Magnetic Resonance Imaging of Diffusion in Granular Flow

    SciTech Connect (OSTI)

    Seymour, Joseph D.; Caprihan, Arvind; Altobelli, Stephen A.; Fukushima, Eiichi

    2000-01-10

    We derive the formalism to obtain spatial distributions of collisional correlation times for macroscopic particles undergoing granular flow from pulsed gradient spin echo nuclear magnetic resonance diffusion data. This is demonstrated with an example of axial motion in the shear flow regime of a 3D granular flow in a horizontal rotating cylinder at one rotation rate. (c) 2000 The American Physical Society.

  9. Nonlinear root-derived carbon sequestration across a gradient of nitrogen and phosphorous deposition

    E-Print Network [OSTI]

    Jackson, Robert B.

    Nonlinear root-derived carbon sequestration across a gradient of nitrogen and phosphorous sequestration of plant-carbon (C) inputs to soil may mitigate rising atmo- spheric carbon dioxide (CO2) concentrations and related climate change but how this sequestration will respond to anthropogenic nitrogen (N

  10. Annealing Thin Colloidal Crystals with Optical Gradient Forces Pamela T. Korda and David G. Grier

    E-Print Network [OSTI]

    Grier, David

    Annealing Thin Colloidal Crystals with Optical Gradient Forces Pamela T. Korda and David G. Grier of Chicago, Chicago, IL 60637 (January 9, 2001) We describe methods for annealing colloidal crystals using a natural tendency to organize themselves into regular three-dimensional arrays known as colloidal crystals

  11. Investigation of Turbulent transition in plane Couette flows Using Energy Gradient Method

    E-Print Network [OSTI]

    Hua-Shu Dou; Boo Cheong Khoo

    2010-06-07

    The energy gradient method has been proposed with the aim of better understanding the mechanism of flow transition from laminar flow to turbulent flow. In this method, it is demonstrated that the transition to turbulence depends on the relative magnitudes of the transverse gradient of the total mechanical energy which amplifies the disturbance and the energy loss from viscous friction which damps the disturbance, for given imposed disturbance. For a given flow geometry and fluid properties, when the maximum of the function K (a function standing for the ratio of the gradient of total mechanical energy in the transverse direction to the rate of energy loss due to viscous friction in the streamwise direction) in the flow field is larger than a certain critical value, it is expected that instability would occur for some initial disturbances. In this paper, using the energy gradient analysis, the equation for calculating the energy gradient function K for plane Couette flow is derived. The result indicates that K reaches the maximum at the moving walls. Thus, the fluid layer near the moving wall is the most dangerous position to generate initial oscillation at sufficient high Re for given same level of normalized perturbation in the domain. The critical value of K at turbulent transition, which is observed from experiments, is about 370 for plane Couette flow when two walls move in opposite directions (anti-symmetry). This value is about the same as that for plane Poiseuille flow and pipe Poiseuille flow (385-389). Therefore, it is concluded that the critical value of K at turbulent transition is about 370-389 for wall-bounded parallel shear flows which include both pressure (symmetrical case) and shear driven flows (anti-symmetrical case).

  12. Root responses along a subambient to elevated CO2 gradient in a C3C4 grassland

    E-Print Network [OSTI]

    Jackson, Robert B.

    Root responses along a subambient to elevated CO2 gradient in a C3­C4 grassland L A U R E L J . A N C3­C4 grassland exposed to a gradient of Ca from preglacial to future levels (230­550 lmol molÀ1 studies have docu- mented increases in belowground plant productivity and metabolism with increased

  13. Environmental effects on distributions of culturable soil oligotrophic bacteria along an elevational gradient in the Chihuahuan Desert

    E-Print Network [OSTI]

    Strauss, Richard E.

    an elevational gradient in the Chihuahuan Desert James H. Campbell*, John C. Zak, Randall M. Jeter, Richard E from five sites along an elevational and vegetational gradient within Big Bend National Park during the first stressors to be investigated. Microbes capable of metabolism at low concentra- tions of carbon

  14. 696 IEEE TRANSACTIONS ON AUTOMATIC CONTROL, VOL. 50, NO. 5, MAY 2005 A Basic Formula for Online Policy Gradient Algorithms

    E-Print Network [OSTI]

    Cao, Xiren

    696 IEEE TRANSACTIONS ON AUTOMATIC CONTROL, VOL. 50, NO. 5, MAY 2005 A Basic Formula for Online Policy Gradient Algorithms Xi-Ren Cao Abstract--This note presents a (new) basic formula for sample learning literature). With this basic formula, many policy-gradient algorithms, including those that have

  15. Radial gradients of phase space density of the outer radiation belt electrons prior to sudden solar wind pressure enhancements

    E-Print Network [OSTI]

    Li, Xinlin

    PSD radial gradient at and beyond GEO prior to a sudden solar wind pressure impact based on the fact by a sudden solar wind pressure enhancement, dayside trapped electrons are transported radially inwards), Radial gradients of phase space density of the outer radiation belt electrons prior to sudden solar wind

  16. Comparing linear ion-temperature-gradient-driven mode stability of the National Compact Stellarator Experiment and a shaped tokamak

    SciTech Connect (OSTI)

    Baumgaertel, J. A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States); Hammett, G. W.; Mikkelsen, D. R. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2013-02-15

    One metric for comparing confinement properties of different magnetic fusion energy configurations is the linear critical gradient of drift wave modes. The critical gradient scale length determines the ratio of the core to pedestal temperature when a plasma is limited to marginal stability in the plasma core. The gyrokinetic turbulence code GS2 was used to calculate critical temperature gradients for the linear, collisionless ion temperature gradient (ITG) mode in the National Compact Stellarator Experiment (NCSX) and a prototypical shaped tokamak, based on the profiles of a JET H-mode shot and the stronger shaping of ARIES-AT. While a concern was that the narrow cross section of NCSX at some toroidal locations would result in steep gradients that drive instabilities more easily, it is found that other stabilizing effects of the stellarator configuration offset this so that the normalized critical gradients for NCSX are competitive with or even better than for the tokamak. For the adiabatic ITG mode, NCSX and the tokamak had similar adiabatic ITG mode critical gradients, although beyond marginal stability, NCSX had larger growth rates. However, for the kinetic ITG mode, NCSX had a higher critical gradient and lower growth rates until a/L{sub T} Almost-Equal-To 1.5 a/L{sub T,crit}, when it surpassed the tokamak's. A discussion of the results presented with respect to a/L{sub T} vs. R/L{sub T} is included.

  17. On the Complete Integrability of Nonlinear Dynamical Systems on Discrete Manifolds within the Gradient-Holonomic Approach

    E-Print Network [OSTI]

    Yarema A. Prykarpatsky; Nikolai N. Bogolubov Jr; Anatoliy K. Prykarpatsky; Valeriy H. Samoylenko

    2011-05-22

    A gradient-holonomic approach for the Lax type integrability analysis of differentialdiscrete dynamical systems is devised. The asymptotical solutions to the related Lax equation are studied, the related gradient identity is stated. The integrability of a discrete nonlinear Schredinger type dynamical system is treated in detail.

  18. Apparatus for the investigation of liquid systems in a shear gradient by small angle neutron scattering (SANS)

    E-Print Network [OSTI]

    Boyer, Edmond

    of small angle neutron scattering from fluids in a constant shear gradient. Typical systems which can angle neutron scattering experiments with liquids have given information about structural pro- perties759 Apparatus for the investigation of liquid systems in a shear gradient by small angle neutron

  19. Algorithm for obtaining the gradient expansion of the local density of states and the free energy of a superconductor

    E-Print Network [OSTI]

    Algorithm for obtaining the gradient expansion of the local density of states and the free energy for obtaining the gauge-invariant gradient expansion of the local density of states and the free energy confirm a recent calculation of the fourth order correction to the free energy by Kosztin, Kos, Stone

  20. The mechanics of coating delamination in thermal gradients A.G. Evans a,, J.W. Hutchinson b

    E-Print Network [OSTI]

    Hutchinson, John W.

    The mechanics of coating delamination in thermal gradients A.G. Evans a,, J.W. Hutchinson b in revised form 16 March 2007 Available online 27 March 2007 Abstract Oxide coatings used for various stress gradient in the coating, governed by these thermal circumstances. Two extreme cool-down scenarios

  1. Dynamics of Singular Vectors in the Semi-Infinite Eady Model: Nonzero but Zero Mean PV Gradient

    E-Print Network [OSTI]

    de Vries, Hylke

    Dynamics of Singular Vectors in the Semi-Infinite Eady Model: Nonzero but Zero Mean PV Gradient H approach based on the potential vorticity (PV) perspective is used to compute the singular vector (SV. The basic-state buoyancy frequency and zonal wind profile are chosen such that the basic-state PV gradient

  2. An Interpretation of Baroclinic Initial Value Problems: Results for Simple Basic States with Nonzero Interior PV Gradients

    E-Print Network [OSTI]

    de Vries, Hylke

    with Nonzero Interior PV Gradients HYLKE DE VRIES, JOHN METHVEN, AND THOMAS H. A. FRAME Department, where the meridional potential vorticity (PV) gradient is zero, perturbation energy growth can, resonance occurs as interior PV anomalies excite the edge waves, and the Orr mechanism involves only

  3. Temperature Gradients are Supported by Cantori in Chaotic S.R.Hudson 1), J.Breslau 1)

    E-Print Network [OSTI]

    Hudson, Stuart

    fields, and show that the temperature, generally a function of three-dimensional space, takes the simple the temperature is a surface function, T = T(), where labels flux surfaces, and gradients can be supportedTH/3-2 Temperature Gradients are Supported by Cantori in Chaotic Fields S.R.Hudson 1), J.Breslau 1

  4. The nucleon electric dipole moment with the gradient flow: the $\\theta$-term contribution

    E-Print Network [OSTI]

    Shindler, Andrea; de Vries, Jordy

    2015-01-01

    We propose a new method to calculate electric dipole moments induced by the strong QCD $\\theta$-term. The method is based on the gradient flow for gauge fields and is free from renormalization ambiguities. We test our method by computing the nucleon electric dipole moments in pure Yang-Mills theory at several lattice spacings, enabling a first-of-its-kind continuum extrapolation. The method is rather general and can be applied for any quantity computed in a $\\theta$ vacuum. This first application of the gradient flow has been successful and demonstrates proof-of-principle, thereby providing a novel method to obtain precise results for nucleon and light nuclear electric dipole moments.

  5. Relativistic transport theory for simple fluids at first order in the gradients: a stable picture

    E-Print Network [OSTI]

    A. Sandoval-Villalbazo; A. L. Garcia-Perciante; L. S. Garcia-Colin

    2009-06-11

    In this paper we show how using a relativistic kinetic equation the ensuing expression for the heat flux can be casted in the form required by Classical Irreversible Thermodynamics. Indeed, it is linearly related to the temperature and number density gradients and not to the acceleration as the so called \\textit{first order in the gradients} theories propose. Since the specific expressions for the transport coefficients are irrelevant for our purposes, the BGK form of the kinetic equation is used. Moreover, from the resulting hydrodynamic equations it is readily seen that the equilibrium state is stable in the presence of the spontaneous fluctuations in the transverse hydrodynamic velocity mode of the simple relativistic fluid. The implications of this result are thoroughly discussed.

  6. Particle Capture Efficiency in a Multi-Wire Model for High Gradient Magnetic Separation

    E-Print Network [OSTI]

    Eisenträger, Almut; Griffiths, Ian M

    2014-01-01

    High gradient magnetic separation (HGMS) is an efficient way to remove magnetic and paramagnetic particles, such as heavy metals, from waste water. As the suspension flows through a magnetized filter mesh, high magnetic gradients around the wires attract and capture the particles, removing them from the fluid. We model such a system by considering the motion of a paramagnetic tracer particle through a periodic array of magnetized cylinders. We show that there is a critical Mason number (ratio of viscous to magnetic forces) below which the particle is captured irrespective of its initial position in the array. Above this threshold, particle capture is only partially successful and depends on the particle's entry position. We determine the relationship between the critical Mason number and the system geometry using numerical and asymptotic calculations. If a capture efficiency below 100% is sufficient, our results demonstrate how operating the HGMS system above the critical Mason number but with multiple separa...

  7. Analytical nuclear gradients for the range-separated many-body dispersion model of noncovalent interactions

    E-Print Network [OSTI]

    Blood-Forsythe, Martin A; DiStasio, Robert A; Car, Roberto; Aspuru-Guzik, Alán

    2015-01-01

    Accurate treatment of the long-range electron correlation energy, including van der Waals (vdW) or dispersion interactions, is essential for describing the structure, dynamics, and function of a wide variety of systems. Among the most accurate models for including dispersion into density functional theory (DFT) is the range-separated many-body dispersion (MBD) method [A. Ambrossetti et al., J. Chem. Phys. 140, 18A508 (2014)], in which the correlation energy is modeled at short-range by a semi-local density functional and at long-range by a model system of coupled quantum harmonic oscillators. In this work, we develop analytical gradients of the MBD energy with respect to nuclear coordinates, including all implicit coordinate dependencies arising from the partitioning of the charge density into Hirshfeld effective volumes. To demonstrate the efficiency and accuracy of these MBD gradients for geometry optimizations of systems with intermolecular and intramolecular interactions, we optimized conformers of the be...

  8. The nucleon electric dipole moment with the gradient flow: the $?$-term contribution

    E-Print Network [OSTI]

    Andrea Shindler; Thomas Luu; Jordy de Vries

    2015-07-09

    We propose a new method to calculate electric dipole moments induced by the strong QCD $\\theta$-term. The method is based on the gradient flow for gauge fields and is free from renormalization ambiguities. We test our method by computing the nucleon electric dipole moments in pure Yang-Mills theory at several lattice spacings, enabling a first-of-its-kind continuum extrapolation. The method is rather general and can be applied for any quantity computed in a $\\theta$ vacuum. This first application of the gradient flow has been successful and demonstrates proof-of-principle, thereby providing a novel method to obtain precise results for nucleon and light nuclear electric dipole moments.

  9. A magnetically shielded room with ultra low residual field and gradient

    SciTech Connect (OSTI)

    Altarev, I.; Chesnevskaya, S.; Gutsmiedl, E.; Kuchler, F.; Lins, T.; Marino, M.; McAndrew, J.; Niessen, B.; Paul, S.; Petzoldt, G.; Singh, J.; Stoepler, R.; Stuiber, S.; Sturm, M.; Taubenheim, B. [Physikdepartment, Technische Universität München, D-85748 Garching (Germany); Babcock, E. [Jülich Center for Neutron Science, Lichtenbergstrasse 1, D-85748 Garching (Germany); Beck, D.; Sharma, S. [Physics Department, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Burghoff, M.; Fan, I. [Physikalisch-Technische Bundesanstalt Berlin, D-10587 Berlin (Germany); and others

    2014-07-15

    A versatile and portable magnetically shielded room with a field of (700 ± 200) pT within a central volume of 1 m × 1 m × 1 m and a field gradient less than 300 pT/m, achieved without any external field stabilization or compensation, is described. This performance represents more than a hundredfold improvement of the state of the art for a two-layer magnetic shield and provides an environment suitable for a next generation of precision experiments in fundamental physics at low energies; in particular, searches for electric dipole moments of fundamental systems and tests of Lorentz-invariance based on spin-precession experiments. Studies of the residual fields and their sources enable improved design of future ultra-low gradient environments and experimental apparatus. This has implications for developments of magnetometry beyond the femto-Tesla scale in, for example, biomagnetism, geosciences, and security applications and in general low-field nuclear magnetic resonance (NMR) measurements.

  10. Vertical two-phase flow regimes and pressure gradients under the influence of SDS surfactant

    SciTech Connect (OSTI)

    Duangprasert, Tanabordee; Sirivat, Anuvat; Siemanond, Kitipat [The Petroleum and Petrochemical College, Chulalongkorn University, Bangkok 10330 (Thailand); Wilkes, James O. [Department of Chemical Engineering, The University of Michigan, Ann Arbor, MI 48109-2136 (United States)

    2008-01-15

    Two-phase gas/liquid flows in vertical pipes have been systematically investigated. Water and SDS surfactant solutions at various concentrations were used as the working fluids. In particular, we focus our work on the influence of surfactant addition on the flow regimes, the corresponding pressure gradients, and the bubble sizes and velocity. Adding the surfactant lowers the air critical Reynolds numbers for the bubble-slug flow and the slug flow transitions. The pressure gradients of SDS solutions are lower than those of pure water especially in the slug flow and the slug-churn flow regimes, implying turbulent drag reduction. At low Re{sub air}, the bubble sizes of the surfactant solution are lower than those of pure water due to the increase in viscosity. With increasing and at high Re{sub air}, the bubble sizes of the SDS solution become greater than those of pure water which is attributed to the effect of surface tension. (author)

  11. The effect of density gradient on the growth rate of relativistic Weibel instability

    SciTech Connect (OSTI)

    Mahdavi, M.; Khodadadi Azadboni, F.

    2014-02-15

    In this paper, the effect of density gradient on the Weibel instability growth rate is investigated. The density perturbations in the near corona fuel, where temperature anisotropy, ?, is larger than the critical temperature anisotropy, ?{sub c}, (??>??{sub c}), enhances the growth rate of Weibel instability due to the sidebands coupled with the electron oscillatory velocity. But for ???2. The analysis shows that relativistic effects and density gradient tend to stabilize the Weibel instability. The growth rate can be reduced by 88% by reducing ? by a factor of 100 and increasing relativistic parameter by a factor of 3.

  12. A genealogy of convex solids via local and global bifurcations of gradient vector fields

    E-Print Network [OSTI]

    Gábor Domokos; Philip Holmes; Zsolt Lángi

    2015-08-19

    Three-dimensional convex bodies can be classified in terms of the number and stability types of critical points on which they can balance at rest on a horizontal plane. For typical bodies these are nondegenerate maxima, minima, and saddle-points, the numbers of which provide a primary classification. Secondary and tertiary classifications use graphs to describe orbits connecting these critical points in the gradient vector field associated with each body. In previous work it was shown that these classifications are complete in that no class is empty. Here we construct 1- and 2-parameter families of convex bodies connecting members of adjacent primary and secondary classes and show that transitions between them can be realized by codimension 1 saddle-node and saddle-saddle (heteroclinic) bifurcations in the gradient vector fields. Our results indicate that all combinatorially possible transitions can be realized in physical shape evolution processes, e.g. by abrasion of sedimentary particles.

  13. Development of Ti/Ti{sub 3}Sn functionally gradient material produced by eutectic bonding method

    SciTech Connect (OSTI)

    Kirihara, S.; Takeda, M.; Tsujimoto, T. [Ibaraki Univ., Hitachi (Japan). Faculty of Engineering] [Ibaraki Univ., Hitachi (Japan). Faculty of Engineering

    1996-07-15

    Although many materials which have a single function have been developed, future needs are anticipated to include materials which have various functions. A functionally gradient material (FGM) which has characteristics of two different materials is a promising candidate for multi-functional material. The present methods for production of FGM, however, are very complicated and costly. In this study the authors answer the serious problem of high production cost by fabricating the FGM by a eutectic bonding method. This fabrication method includes structural control of FGM by changing the cooling process. They describe Ti/Ti{sub 3}Sn FGM obtained by the eutectic bonding method, and tell how the structure of its composition gradient part is changed by controlling the cooling process.

  14. Towards an Optimal Gradient-dependent Energy Functional of the PZ-SIC Form

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

    Jónsson, Elvar Örn; Lehtola, Susi; Jónsson, Hannes

    2015-06-01

    Results of Perdew–Zunger self-interaction corrected (PZ-SIC) density functional theory calculations of the atomization energy of 35 molecules are compared to those of high-level quantum chemistry calculations. While the PBE functional, which is commonly used in calculations of condensed matter, is known to predict on average too high atomization energy (overbinding of the molecules), the application of PZ-SIC gives a large overcorrection and leads to significant underestimation of the atomization energy. The exchange enhancement factor that is optimal for the generalized gradient approximation within the Kohn-Sham (KS) approach may not be optimal for the self-interaction corrected functional. The PBEsol functional, wheremore »the exchange enhancement factor was optimized for solids, gives poor results for molecules in KS but turns out to work better than PBE in PZ-SIC calculations. The exchange enhancement is weaker in PBEsol and the functional is closer to the local density approximation. Furthermore, the drop in the exchange enhancement factor for increasing reduced gradient in the PW91 functional gives more accurate results than the plateaued enhancement in the PBE functional. A step towards an optimal exchange enhancement factor for a gradient dependent functional of the PZ-SIC form is taken by constructing an exchange enhancement factor that mimics PBEsol for small values of the reduced gradient, and PW91 for large values. The average atomization energy is then in closer agreement with the high-level quantum chemistry calculations, but the variance is still large, the F2 molecule being a notable outlier.« less

  15. Gravitational resonance spectroscopy with an oscillating magnetic field gradient in the GRANIT flow through arrangement

    E-Print Network [OSTI]

    G. Pignol; S. Baessler; V. V. Nesvizhevsky; K. Protasov; D. Rebreyend; A. Yu. Voronin

    2014-08-05

    Gravitational resonance spectroscopy consists in measuring the energy spectrum of bouncing ultracold neutrons above a mirror by inducing resonant transitions between different discrete quantum levels. We discuss how to induce the resonances with a flow through arrangement in the GRANIT spectrometer, excited by an oscillating magnetic field gradient. The spectroscopy could be realized in two distinct modes (so called DC and AC) using the same device to produce the magnetic excitation. We present calculations demonstrating the feasibility of the newly proposed AC mode.

  16. Thermodynamics and reference scale of SU(3) gauge theory from gradient flow on fine lattices

    E-Print Network [OSTI]

    Masakiyo Kitazawa; Masayuki Asakawa; Tetsuo Hatsuda; Takumi Iritani; Etsuko Itou; Hiroshi Suzuki

    2015-11-17

    We study the parametrization of lattice spacing and thermodynamics of SU(3) gauge theory on the basis of the Yang-Mills gradient flow on fine lattices. The lattice spacing of the Wilson gauge action is determined over a wide range $6.3\\le\\beta\\le7.5$ with high accuracy. The measurements of the flow time and lattice spacing dependences of the expectation values of the energy-momentum tensor are performed on fine lattices.

  17. High gradient magnetic beneficiation of dry pulverized coal via upwardly directed recirculating fluidization

    DOE Patents [OSTI]

    Eissenberg, David M. (Oak Ridge, TN); Liu, Yin-An (Opelika, AL)

    1980-01-01

    This invention relates to an improved device and method for the high gradient magnetic beneficiation of dry pulverized coal, for the purpose of removing sulfur and ash from the coal whereby the product is a dry environmentally acceptable, low-sulfur fuel. The process involves upwardly directed recirculating air fluidization of selectively sized powdered coal in a separator having sections of increasing diameters in the direction of air flow, with magnetic field and flow rates chosen for optimum separations depending upon particulate size.

  18. Thermodynamics and reference scale of SU(3) gauge theory from gradient flow on fine lattices

    E-Print Network [OSTI]

    Kitazawa, Masakiyo; Hatsuda, Tetsuo; Iritani, Takumi; Itou, Etsuko; Suzuki, Hiroshi

    2015-01-01

    We study the parametrization of lattice spacing and thermodynamics of SU(3) gauge theory on the basis of the Yang-Mills gradient flow on fine lattices. The lattice spacing of the Wilson gauge action is determined over a wide range $6.3\\le\\beta\\le7.5$ with high accuracy. The measurements of the flow time and lattice spacing dependences of the expectation values of the energy-momentum tensor are performed on fine lattices.

  19. Strict convexity of the free energy for non-convex gradient models at moderate $?$

    E-Print Network [OSTI]

    Codina Cotar; Jean-Dominique Deuschel; Stefan Müller

    2008-01-08

    We consider a gradient interface model on the lattice with interaction potential which is a non-convex perturbation of a convex potential. We show using a one-step multiple scale analysis the strict convexity of the surface tension at high temperature. This is an extension of Funaki and Spohn's result, where the strict convexity of potential was crucial in their proof that for every tilt there is a unique, shift invariant, ergodic Gibbs measure for the $\

  20. The building up of the disk galaxy M33 and the evolution of the metallicity gradient

    E-Print Network [OSTI]

    Laura Magrini; Edvige Corbelli; Daniele Galli

    2007-04-24

    The evolution of radial gradients of metallicity in disk galaxies and its relation with the disk formation are not well understood. Theoretical models of galactic chemical evolution make contrasting predictions about the time evolution of metallicity gradients. To test chemical evolution models and trace the star formation and accretion history of low luminosity disk galaxies we focus on the Local Group galaxy M33. We analyze O/H and S/H abundances in planetary nebulae, H{\\sc ii} regions, and young stars, together with known [Fe/H] abundances in the old stellar population of M33. With a theoretical model, we follow the time evolution of gas (diffuse and condensed in clouds), stars, and chemical abundances in the disk of M33, assuming that the galaxy is accreting gas from an external reservoir. Our model is able to reproduce the available observational constraints on the distribution of gas and stars in M33 and to predict the time evolution of several chemical abundances. In particular, we find that a model characterized by a continuous infall of gas on the disk, at a rate of $\\dot M_{\\rm inf}\\approx 1$ $M_\\odot$ yr$^{-1}$, almost constant with time, can also account for the relatively high rate of star formation and for the shallow chemical gradients. Supported by a large sample of high resolution observations for this nearby galaxy, we conclude that the metallicity in the disk of M33 has increased with time at all radii, with a continuous flattening of the gradient over the last $\\sim 8$ Gyr.

  1. The Vertical Metallicity Gradient of the Milky Way Disk: Transitions in [a/Fe] Populations

    E-Print Network [OSTI]

    Schlesinger, Katharine J; Rockosi, Constance M; Lee, Young Sun; Beers, Timothy C; Harding, Paul; Prieto, Carlos Allende; Bird, Jonathan C; Schoenrich, Ralph; Yanny, Brian; Schneider, Donald P; Weaver, Benjamin A; Brinkmann, Jon

    2014-01-01

    Using G dwarfs from the Sloan Extension for Galactic Understanding and Exploration (SEGUE) survey, we have determined a vertical metallicity gradient over a large volume of the Milky Way's disk, and examined how this gradient varies for different [a/Fe] subsamples. This sample contains over 40,000 stars with low-resolution spectroscopy over 144 lines of sight. We employ the SEGUE Stellar Parameter Pipeline (SSPP) to obtain estimates of effective temperature, surface gravity, [Fe/H], and [a/Fe] for each star and extract multiple volume-complete subsamples of approximately 1000 stars each. Based on the survey's consistent target-selection algorithm, we adjust each subsample to determine an unbiased picture of the disk in [Fe/H] and [a/Fe]; consequently, each individual star represents the properties of many. The SEGUE sample allows us to constrain the vertical metallicity gradient for a large number of stars over a significant volume of the disk, between ~0.3 and 1.6 kpc from the Galactic plane, and examine the...

  2. Diffraction Profiles of Elasticity Bent Single Crystals with Constant Strain Gradients

    SciTech Connect (OSTI)

    Yan,H.; Kalenci, O.; Noyan, I.

    2007-01-01

    This work presents a set of equations that can be used to predict the dynamical diffraction profile from a non-transparent single crystal with a constant strain gradient examined in Bragg reflection geometry with a spherical incident X-ray beam. In agreement with previous work, the present analysis predicts two peaks: a primary diffraction peak, which would have still been observed in the absence of the strain gradient and which exits the specimen surface at the intersection point of the incident beam with the sample surface, and a secondary (mirage) peak, caused by the deflection of the wavefield within the material, which exits the specimen surface further from this intersection point. The integrated intensity of the mirage peak increases with increasing strain gradient, while its separation from the primary reflection peak decreases. The directions of the rays forming the mirage peak are parallel to those forming the primary diffraction peak. However, their spatial displacement might cause (fictitious) angular shifts in diffractometers equipped with area detectors or slit optics. The analysis results are compared with experimental data from an Si single-crystal strip bent in cantilever configuration, and the implications of the mirage peak for Laue analysis and high-precision diffraction measurements are discussed.

  3. Propagation of chaos, Wasserstein gradient flows and toric Kahler-Einstein metrics

    E-Print Network [OSTI]

    Robert J. Berman; Magnus Onnheim

    2015-06-09

    Motivated by a probabilistic approach to Kahler-Einstein metrics we consider a general non-equlibrium statistical mechanics model in Euclidean space consisting of the stochastic gradient flow of a given quasi-convex N particle interaction energy. We show that a deterministic macroscopic evolution equation emerges in the large N-limit of many particles. The proof uses the theory of weak gradient flows on the Wasserstein space and in particular De Georgi's notion of minimizing movements. Applied to the setting of permanental point processes at negative temperature the corresponding limiting evolution equation yields a new drift-diffusion equation, coupled to the Monge-Ampere operator, whose static solutions correspond to toric Kahler-Einstein metrics. This drift-diffusion equation is the gradient flow on the Wasserstein space of probability measures of the K-energy functional in Kahler geometry and it can be seen as a fully non-linear version of various extensively studied dissipative evolution equations and conservations laws, including the Keller-Segal equation and Burger's equation. We also obtain a real probabilistic analog of the complex geometric Yau-Tian-Donaldson conjecture in this setting. In another direction applications to singular pair interactions in 1D are given, leading to sharp convergence results. Complex geometric aspects of these results will be discussed elsewhere.

  4. A study of self organized criticality in ion temperature gradient mode driven gyrokinetic turbulence

    SciTech Connect (OSTI)

    Mavridis, M.; Isliker, H.; Vlahos, L.; Görler, T.; Jenko, F.; Told, D.

    2014-10-15

    An investigation on the characteristics of self organized criticality (Soc) in ITG mode driven turbulence is made, with the use of various statistical tools (histograms, power spectra, Hurst exponents estimated with the rescaled range analysis, and the structure function method). For this purpose, local non-linear gyrokinetic simulations of the cyclone base case scenario are performed with the GENE software package. Although most authors concentrate on global simulations, which seem to be a better choice for such an investigation, we use local simulations in an attempt to study the locally underlying mechanisms of Soc. We also study the structural properties of radially extended structures, with several tools (fractal dimension estimate, cluster analysis, and two dimensional autocorrelation function), in order to explore whether they can be characterized as avalanches. We find that, for large enough driving temperature gradients, the local simulations exhibit most of the features of Soc, with the exception of the probability distribution of observables, which show a tail, yet they are not of power-law form. The radial structures have the same radial extent at all temperature gradients examined; radial motion (transport) though appears only at large temperature gradients, in which case the radial structures can be interpreted as avalanches.

  5. Coronal Heating Driven by Magnetic-gradient Pumping Mechanism in Solar Plasmas

    E-Print Network [OSTI]

    Tan, Baolin

    2014-01-01

    The solar coronal heating is a longstanding mystery in astrophysics. Considering that the solar magnetic field is spatially inhomogeneous with considerable magnetic gradient from solar surface to the corona, this work proposes a magnetic gradient pumping (MGP) mechanism and try to explain the formation of hot plasma upflows, such as the hot type II spicules and hot plasma ejections, etc. In MGP mechanism, the magnetic gradients drive the energetic particles to move upwards from the underlying solar atmosphere and form hot upflows. These upflow energetic particles deposit in corona and make it becoming very hot. Roughly estimations indicate that the solar corona can be heated to above 1 million degrees, and the upflow velocity is about 40 km/s in chromosphere and about 130 km/s in the corona. The solar magnetic flux tubes act as pumpers to extract energetic particles from the underlying thermal photosphere, convey them and deposit in the corona. The deposition of energetic particles will make the corona become...

  6. Coronal heating driven by a magnetic gradient pumping mechanism in solar plasmas

    SciTech Connect (OSTI)

    Tan, Baolin

    2014-11-10

    The heating of the solar corona is a longstanding mystery in astrophysics. Considering that the solar magnetic field is spatially inhomogeneous with a considerable magnetic gradient from the solar surface to the corona, this work proposes a magnetic gradient pumping (MGP) mechanism to try to explain the formation of hot plasma upflows, such as hot type II spicules and hot plasma ejections. In the MGP mechanism, the magnetic gradient may drive the energetic particles to move upward from the underlying solar atmosphere and form hot upflows. These upflow energetic particles are deposited in the corona, causing it to become very hot. Rough estimations indicate that the solar corona can be heated to above 1 million degrees, and the upflow velocity is about 40 km s{sup –1} in the chromosphere and about 130 km s{sup –1} in the corona. The solar magnetic flux tubes act as pumpers to extract energetic particles from the underlying thermal photosphere, convey them, and deposit them in the corona. The deposit of these energetic particles causes the corona to become hot, and the escape of such particles from the photosphere leaves it a bit cold. This mechanism can present a natural explanation to the mystery of solar coronal heating.

  7. Subwavelength silicon through-hole arrays as an all-dielectric broadband terahertz gradient index metamaterial

    SciTech Connect (OSTI)

    Park, Sang-Gil; Jeong, Ki-Hun, E-mail: kjeong@kaist.ac.kr [Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); KAIST Institute for Optical Science and Technology, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Lee, Kanghee; Han, Daehoon; Ahn, Jaewook [KAIST Institute for Optical Science and Technology, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2014-09-01

    Structuring at subwavelength scales brings out artificial media with anomalous optical features called metamaterials. All-dielectric metamaterials have high potential for practical applications over the whole electromagnetic spectrum owing to low loss and optical isotropy. Here, we report subwavelength silicon through-hole arrays as an all-dielectric gradient index metamaterial with broadband THz operation. The unit cell consists of a single subwavelength through-hole on highly resistive monocrystalline silicon. Depending on the fill-factor and period, the effective index was linearly modulated at 0.3–1.6 THz. The experimental results also demonstrate silicon gradient refractive index (Si-GRIN) lenses with parabolic index profiles through the spatial modification of a single unit cell along the radial direction. Si-GRIN lenses either focus 0.4–1.6 THz beam to the diffraction-limit or serve as a flat and thin solid immersion lens on the backside of THz photoconductive antenna for highly efficient pulse extraction. This all-dielectric gradient index metamaterial opens up opportunities for integrated THz GRIN optics.

  8. Thermal gradient-induced forces on geodesic reference masses for LISA

    SciTech Connect (OSTI)

    Carbone, L.; Ciani, G.; Dolesi, R.; Hueller, M.; Tombolato, D.; Vitale, S.; Weber, W. J.; Cavalleri, A.

    2007-11-15

    The low frequency sensitivity of space-borne gravitational wave observatories will depend critically on the geodesic purity of the trajectories of orbiting test masses. Fluctuations in the temperature difference across the enclosure surrounding the free-falling test mass can produce noisy forces through several processes, including the radiometric effect, radiation pressure, and outgassing. We present here a detailed experimental investigation of thermal gradient-induced forces for the Laser Interferometer Space Antenna (LISA) gravitational wave mission and the LISA Pathfinder, employing high resolution torsion pendulum measurements of the torque on a LISA-like test mass suspended inside a prototype of the LISA gravitational reference sensor that will surround the test mass in orbit. The measurement campaign, accompanied by numerical simulations of the radiometric and radiation pressure effects, allows a more accurate and representative characterization of thermal-gradient forces in the specific geometry and environment relevant to LISA free-fall. The pressure dependence of the measured torques allows clear identification of the radiometric effect, in quantitative agreement with the model developed. In the limit of zero gas pressure, the measurements are most likely dominated by outgassing, but at a low level that does not threaten the current LISA noise estimate, which assumes a maximum net force per degree of temperature difference of 100(pN/K) for the overall thermal gradient-induced effects.

  9. Groundwater Flow and Thermal Modeling to Support a Preferred Conceptual Model for the Large Hydraulic Gradient North of Yucca Mountain

    SciTech Connect (OSTI)

    McGraw, D.; Oberlander, P.

    2007-12-18

    The purpose of this study is to report on the results of a preliminary modeling framework to investigate the causes of the large hydraulic gradient north of Yucca Mountain. This study builds on the Saturated Zone Site-Scale Flow and Transport Model (referenced herein as the Site-scale model (Zyvoloski, 2004a), which is a three-dimensional saturated zone model of the Yucca Mountain area. Groundwater flow was simulated under natural conditions. The model framework and grid design describe the geologic layering and the calibration parameters describe the hydrogeology. The Site-scale model is calibrated to hydraulic heads, fluid temperature, and groundwater flowpaths. One area of interest in the Site-scale model represents the large hydraulic gradient north of Yucca Mountain. Nearby water levels suggest over 200 meters of hydraulic head difference in less than 1,000 meters horizontal distance. Given the geologic conceptual models defined by various hydrogeologic reports (Faunt, 2000, 2001; Zyvoloski, 2004b), no definitive explanation has been found for the cause of the large hydraulic gradient. Luckey et al. (1996) presents several possible explanations for the large hydraulic gradient as provided below: The gradient is simply the result of flow through the upper volcanic confining unit, which is nearly 300 meters thick near the large gradient. The gradient represents a semi-perched system in which flow in the upper and lower aquifers is predominantly horizontal, whereas flow in the upper confining unit would be predominantly vertical. The gradient represents a drain down a buried fault from the volcanic aquifers to the lower Carbonate Aquifer. The gradient represents a spillway in which a fault marks the effective northern limit of the lower volcanic aquifer. The large gradient results from the presence at depth of the Eleana Formation, a part of the Paleozoic upper confining unit, which overlies the lower Carbonate Aquifer in much of the Death Valley region. The Eleana Formation is absent at borehole UE-25 p#1 at Yucca Mountain, which penetrated the lower Carbonate Aquifer directly beneath the lower volcanic confining unit. The Site-scale model uses an area of very low permeability, referenced as the east-west barrier, to simulate the large hydraulic gradient. The Site-scale model is further refined in this study to provide a base-case model for exploring the geologic causes of the large hydraulic gradient.

  10. The bends in the slopes of radial abundance gradients in the disks of spiral galaxies -- do they exist?

    E-Print Network [OSTI]

    L. S. Pilyugin

    2002-10-17

    Spiral galaxies with a reported bend in the slope of gradient in the oxygen abundances (O/H)_R23, derived with traditionally used R23 - method, were examined. It is shown that the artificial origin of the reported bends can be naturally explained. Two reasons that result in a false bend in the slope of (O/H)_R23 gradient are indicated. It is concluded that at the present time there is no example of a galaxy with an undisputable established bend in the slope of the oxygen abundance gradient.

  11. Noise in the processing and application of magnetic gradients Leon Foks, Kristofer Davis, and Yaoguo Li, Center for Gravity, Electrical, and Magnetics, Colorado School of Mines,

    E-Print Network [OSTI]

    Noise in the processing and application of magnetic gradients Leon Foks, Kristofer Davis SUMMARY The increased use of magnetic gradients brings about the need for reliable noise characterization to characterize noise in magnetic gradient data. We use an equivalent source technique and finite differ- ence

  12. Attachment of Cells to Islands Presenting Gradients of Adhesion Ligands Rafe T. Petty, Hung-Wing Li, Jane H. Maduram, Rustem Ismagilov, and Milan Mrksich*

    E-Print Network [OSTI]

    Ismagilov, Rustem F.

    Attachment of Cells to Islands Presenting Gradients of Adhesion Ligands Rafe T. Petty, Hung-Wing Li@uchicago.edu Mammalian and bacterial cells live in gradients. Soluble and immobilized gradients of signaling proteins guide the trafficking of cells and direct their development and maintenance.1 New methods to determine

  13. Acta Appl.Math., 106, N3, (2009), 473-499. Dynamical Systems Gradient method for solving nonlinear equations with monotone

    E-Print Network [OSTI]

    2009-01-01

    Acta Appl.Math., 106, N3, (2009), 473-499. Dynamical Systems Gradient method for solving nonlinear@math.ksu.edu 1 #12;Dynamical Systems Gradient method for solving nonlinear equations with monotone operators N. S A version of the Dynamical Systems Gradient Method for solving ill-posed nonlinear monotone operator

  14. Design, prototyping, and testing of an apparatus for establishing a linear temperature gradient in experimental fish tanks

    E-Print Network [OSTI]

    Kadri, Romi Sinclair

    2014-01-01

    Immunology researchers require a new type of fish tank that provides a linear thermal gradient for experimental zebrafish in order to improve the accuracy and validity of their research. Zebrafish require the ability to ...

  15. Electrical Circuit Flashover Model of Polluted Insulators under AC Voltage Based on the Arc Root Voltage Gradient Criterion

    E-Print Network [OSTI]

    Yang, Qing

    In order to study the flashover mechanism of polluted insulators under AC voltage, a new arc propagation criterion which is based on an arc root voltage gradient is proposed. This criterion can explain the variation of the ...

  16. Vehicle Technologies Office Merit Review 2015: NMR and Pulse Field Gradient Studies of SEI and Electrode Structure

    Broader source: Energy.gov [DOE]

    Presentation given by U. of Cambridge at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about NMR and pulse field gradient...

  17. Community Metabolism Along Nutrient and Salinity Gradients of the Potomac River Estuary: An Application from Continuous Monitoring Sites

    E-Print Network [OSTI]

    Boynton, Walter R.

    Community Metabolism Along Nutrient and Salinity Gradients of the Potomac River Estuary to make metabolism estimates. We used data from 14 of these locations from March through October 2007

  18. New Solutions of Half-Space Contact Problems Using Potential Theory, Surface Elasticity and Strain Gradient Elasticity 

    E-Print Network [OSTI]

    Zhou, Songsheng

    2012-02-14

    - the adhesive contact mechanics, surface elasticity and strain gradient elasticity - are employed to study the mechanical behaviors of a semi-infinite solid induced by the boundary forces. A unified treatment of axisymmetric adhesive contact problems...

  19. Solutions of Eshelby-Type Inclusion Problems and a Related Homogenization Method Based on a Simplified Strain Gradient Elasticity Theory 

    E-Print Network [OSTI]

    Ma, Hemei

    2011-08-08

    Eshelby-type inclusion problems of an infinite or a finite homogeneous isotropic elastic body containing an arbitrary-shape inclusion prescribed with an eigenstrain and an eigenstrain gradient are analytically solved. The solutions are based on a...

  20. Formation of the Galactic bulge from a two-component stellar disk: Explaining cylindrical rotation and vertical metallicity gradient

    E-Print Network [OSTI]

    Bekki, Kenji

    2011-01-01

    Recent observational studies have revealed that the Galactic bulge has cylindrical rotation and a steeper vertical metallicity gradient. We adopt two representative models for the bulge formation and thereby investigate whether the two models can explain both the observed cylindrical rotation and vertical metallicity gradient in a self-consistent manner. One is the "pure disk scenario" (PDS) in which the bulge is formed from a pure thin stellar disk through spontaneous bar instability. The other is the "two-component disk scenario" (TCDS) in which the bulge is formed from a disk composed of thin and thick disks through bar instability. Our numerical simulations show that although PDS can reproduce the cylindrical rotation, it shows a rather flatter vertical metallicity gradient that is inconsistent with observations. The derived flatter metallicity gradient is due to the vertical mixing of stars with different initial metallicities by the stellar bar. This result implies that the bulge can not be simply forme...

  1. Patterns of water and heat flux across a biome gradient from tropical forest to savanna in Brazil

    E-Print Network [OSTI]

    2009-01-01

    of Mato Grosso, Brasil, Water Resour. Res. , 38(6), 1094,2009 Patterns of water and heat flux across a biome gradientFigueira (2004), Seasonality of water and heat fluxes over a

  2. Numerical simulations of the bending of narrow-angle-tail radio jets by ram pressure or pressure gradients

    SciTech Connect (OSTI)

    Soker, N.; Sarazin, C.L.; O'Dea, C.P.

    1988-04-01

    Three-dimensional numerical hydrodynamic simulations are used to study the bending of radio jets. The simulations are compared with observations of jets in narrow-angle-tail radio sources. Two mechanisms for the observed bending are considered: direct bending of quasi-continuous jets by ram pressure from intergalactic gas and bending by pressure gradients in the interstellar gas of the host galaxy, the pressure gradients themselves being the result of ram pressure by intergalactic gas. It is shown that the pressure gradients are much less effective in bending jets, implying that the jets have roughly 30 times lower momentum fluxes if they are bent by this mechanism. Ram-pressure bending produces jets with kidney-shaped cross sections; when observed from the side, these jets appear to have diffuse extensions on the downstream side. On the other hand, pressure-gradient bending causes the jets to be densest near their upstream side. 31 references.

  3. A gradient analysis of urban landscape pattern: a case study from the Phoenix metropolitan region, Arizona, USA

    E-Print Network [OSTI]

    Wu, Jianguo "Jingle"

    A gradient analysis of urban landscape pattern: a case study from the Phoenix metropolitan region the spatial pattern of urbanization in the Phoenix metropolitan area, Arizona, USA. Several landscape metrics

  4. Relativistic klystron driven compact high gradient accelerator as an injector to an X-ray synchrotron radiation ring

    DOE Patents [OSTI]

    Yu, David U. L. (1912 MacArthur St., Rancho Palos Verdes, CA 90732)

    1990-01-01

    A compact high gradient accelerator driven by a relativistic klystron is utilized to inject high energy electrons into an X-ray synchrotron radiation ring. The high gradients provided by the relativistic klystron enables accelerator structure to be much shorter (typically 3 meters) than conventional injectors. This in turn enables manufacturers which utilize high energy, high intensity X-rays to produce various devices, such as computer chips, to do so on a cost effective basis.

  5. Method and means for a spatial and temporal probe for laser-generated plumes based on density gradients

    DOE Patents [OSTI]

    Yeung, Edward S. (Ames, IA); Chen, Guoying (Laramie, WY)

    1990-05-01

    A method and means for a spatial and temporal probe for laser generated plumes based on density gradients includes generation of a plume of vaporized material from a surface by an energy source. The probe laser beam is positioned so that the plume passes through the probe laser beam. Movement of the probe laser beam caused by refraction from the density gradient of the plume is monitored. Spatial and temporal information, correlated to one another, is then derived.

  6. Overview of high gradient SRF R&D for ILC cavities at Jefferson Lab

    SciTech Connect (OSTI)

    Geng, Rongli [JLAB

    2009-11-01

    We report the progress on high gradient R&D of ILC cavities at Jefferson Lab (JLab) since the Beijing workshop. Routine 9-cell cavity electropolishing (EP) processing and RF testing has been enhanced with added surface mapping and T-mapping instrumentations. 12 new 9-cell cavities (10 of them are baseline fine-grain TESLA-shape cavities: 5 built by ACCEL/Research Instruments, 4 by AES and 1 by JLab; 2 of them are alternative cavities: 1 fine-grain ICHIRO-shape cavity built by KEK/Japan industry and 1 large-grain TESLA-shape cavity built by JLab) are EP processed and tested. 76 EP cycles are accumulated, corresponding to more than 200 hours of active EP time. Field emission (FE) and quench behaviors of electropolished 9-cell cavities are studied. EP process continues to be optimized, resulting in advanced procedures and hence improved cavity performance. Several 9-cell cavities reached 35 MV/m after the first light EP processing. FE-free performance has been demonstrated in 9-cell cavities in 35-40 MV/m range. 1-cell cavity studies explore new techniques for defect removal as well as advanced integrated cavity processing. Surface studies of niobium samples electropolished together with real cavities provide new insight into the nature of field emitters. Close cooperation with the US cavity fabrication industry has been undertaking with the successful achievement of 41 MV/m for the first time in a 9-cell ILC cavity built by AES. As the size of the data set grows, it is now possible to construct gradient yield curves, from which one can see that significant progress has been made in raising the high gradient yield.

  7. Double active shielded magnetic field gradient design with minimum inductance method 

    E-Print Network [OSTI]

    Wang, Xu

    1992-01-01

    ratio, m; may have 2i + 1 values, i, i ? 1, . . . . . . , ? i. For the hydrogen nucleus, the spin is &i, and p is 42. 58 MHz/Tesla. The Hamiltonian for this system in the lab frame can be written as H = H, yg+ H;?u (1. 1. 2) where = p' H, fy ? + V... As has been discussed before, some MRI techniques require fast switching of the gradient. However, in many MRI instruments today, the main static magnetic fields (around the order of 1 Tesla) are provided by superconducting inagnets. They have...

  8. Mitigating illumination gradients in a SAR image based on the image data and antenna beam pattern

    DOE Patents [OSTI]

    Doerry, Armin W.

    2013-04-30

    Illumination gradients in a synthetic aperture radar (SAR) image of a target can be mitigated by determining a correction for pixel values associated with the SAR image. This correction is determined based on information indicative of a beam pattern used by a SAR antenna apparatus to illuminate the target, and also based on the pixel values associated with the SAR image. The correction is applied to the pixel values associated with the SAR image to produce corrected pixel values that define a corrected SAR image.

  9. Renormalization constants of the lattice energy momentum tensor using the gradient flow

    E-Print Network [OSTI]

    Francesco Capponi; Luigi Del Debbio; Agostino Patella; Antonio Rago

    2015-12-14

    We employ a new strategy for a non perturbative determination of the renormalized energy momentum tensor. The strategy is based on the definition of suitable lattice Ward identities probed by observables computed along the gradient flow. The new set of identities exhibits many interesting qualities, arising from the UV finiteness of flowed composite operators. In this paper we show how this method can be used to non perturbatively renormalize the energy momentum tensor for a SU(3) Yang-Mills theory, and report our numerical results.

  10. Functionally gradient material for membrane reactors to convert methane gas into value-added products

    DOE Patents [OSTI]

    Balachandran, U.; Dusek, J.T.; Kleefisch, M.S.; Kobylinski, T.P.

    1996-11-12

    A functionally gradient material for a membrane reactor for converting methane gas into value-added-products includes an outer tube of perovskite, which contacts air; an inner tube which contacts methane gas, of zirconium oxide, and a bonding layer between the perovskite and zirconium oxide layers. The bonding layer has one or more layers of a mixture of perovskite and zirconium oxide, with the layers transitioning from an excess of perovskite to an excess of zirconium oxide. The transition layers match thermal expansion coefficients and other physical properties between the two different materials. 7 figs.

  11. Functionally gradient material for membrane reactors to convert methane gas into value-added products

    DOE Patents [OSTI]

    Balachandran, Uthamalingam (Hinsdale, IL); Dusek, Joseph T. (Lombard, IL); Kleefisch, Mark S. (Napersville, IL); Kobylinski, Thadeus P. (Lisle, IL)

    1996-01-01

    A functionally gradient material for a membrane reactor for converting methane gas into value-added-products includes an outer tube of perovskite, which contacts air; an inner tube which contacts methane gas, of zirconium oxide, and a bonding layer between the perovskite and zirconium oxide layers. The bonding layer has one or more layers of a mixture of perovskite and zirconium oxide, with the layers transitioning from an excess of perovskite to an excess of zirconium oxide. The transition layers match thermal expansion coefficients and other physical properties between the two different materials.

  12. Turbulent electron transport in edge pedestal by electron temperature gradient turbulence

    SciTech Connect (OSTI)

    Singh, R.; Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 ; Jhang, Hogun; Diamond, P. H.; CMTFO and CASS, University of California, San Diego 92093-0424, California

    2013-11-15

    We present a model for turbulent electron thermal transport at the edge pedestal in high (H)-mode plasmas based on electron temperature gradient (ETG) turbulence. A quasi-linear analysis of electrostatic toroidal ETG modes shows that both turbulent electron thermal diffusivity and hyper-resistivity exhibits the Ohkawa scaling in which the radial correlation length of turbulence becomes the order of electron skin depth. Combination of the Ohkawa scales and the plasma current dependence results in a novel confinement scaling inside the pedestal region. It is also shown that ETG turbulence induces a thermoelectric pinch, which may accelerate the density pedestal formation.

  13. Rotating-frame gradient fields for magnetic resonance imaging and nuclear magnetic resonance in low fields

    DOE Patents [OSTI]

    Bouchard, Louis-Serge; Pines, Alexander; Demas, Vasiliki

    2014-01-21

    A system and method for Fourier encoding a nuclear magnetic resonance (NMR) signal is disclosed. A static magnetic field B.sub.0 is provided along a first direction. An NMR signal from the sample is Fourier encoded by applying a rotating-frame gradient field B.sub.G superimposed on the B.sub.0, where the B.sub.G comprises a vector component rotating in a plane perpendicular to the first direction at an angular frequency .omega.in a laboratory frame. The Fourier-encoded NMR signal is detected.

  14. Ion-temperature-gradient sensitivity of the hydrodynamic instability caused by shear in the magnetic-field-aligned plasma flow

    SciTech Connect (OSTI)

    Mikhailenko, V. V.; Mikhailenko, V. S.; Lee, Hae June; Koepke, M. E.

    2014-07-15

    The cross-magnetic-field (i.e., perpendicular) profile of ion temperature and the perpendicular profile of the magnetic-field-aligned (parallel) plasma flow are sometimes inhomogeneous for space and laboratory plasma. Instability caused either by a gradient in the ion-temperature profile or by shear in the parallel flow has been discussed extensively in the literature. In this paper, (1) hydrodynamic plasma stability is investigated, (2) real and imaginary frequency are quantified over a range of the shear parameter, the normalized wavenumber, and the ratio of density-gradient and ion-temperature-gradient scale lengths, and (3) the role of inverse Landau damping is illustrated for the case of combined ion-temperature gradient and parallel-flow shear. We find that increasing the ion-temperature gradient reduces the instability threshold for the hydrodynamic parallel-flow shear instability, also known as the parallel Kelvin-Helmholtz instability or the D'Angelo instability. We also find that a kinetic instability arises from the coupled, reinforcing action of both free-energy sources. For the case of comparable electron and ion temperature, we illustrate analytically the transition of the D'Angelo instability to the kinetic instability as (a) the shear parameter, (b) the normalized wavenumber, and (c) the ratio of density-gradient and ion-temperature-gradient scale lengths are varied and we attribute the changes in stability to changes in the amount of inverse ion Landau damping. We show that near a normalized wavenumber k{sub ?}?{sub i} of order unity (i) the real and imaginary values of frequency become comparable and (ii) the imaginary frequency, i.e., the growth rate, peaks.

  15. Performance of conjugate gradient-like algorithms in transient two-phase subchannel analysis

    SciTech Connect (OSTI)

    Turner, J.A. (Los Alamos National Lab., NM (USA)); Doster, M.J. (North Carolina State Univ., Raleigh, NC (USA). Dept. of Nuclear Engineering)

    1991-01-01

    A transient, drift-flux subchannel analysis code (SWIRL) has been created for the development and evaluation of algorithms for the solution of weakly three-dimensional fluid flow problems. Spatial discretization on a staggered grid, semi-implicit temporal discretization, and algebraic reduction of the conservation equations of mass, energy, and momentum result in nonsymmetric block-tridiagonal linear systems of equations that must be solved for the pressure distribution at each time step of a transient. The solution of these systems of equations is the most time-consuming portion of the code, and direct, stationary iterative, and preconditioned conjugate gradient (CG)-like methods have been investigated both for a simple approach to steady-state and for a severe transient. The best direct algorithm appears to be an efficient implementation of block elimination, and iterative methods are compared to this algorithm for accuracy, robustness, and efficiency. Results presented here indicate that preconditioned CG-like methods such as Sonneveld's conjugate gradients squared are superior to an efficient direct method. 44 refs., 13 figs.

  16. Measurement of laser heating in spin exchange optical pumping by NMR diffusion sensitization gradients

    SciTech Connect (OSTI)

    Parnell, Steven R.; Deppe, Martin H.; Ajraoui, Salma; Parra-Robles, Juan; Wild, Jim M.; Boag, Stephen

    2010-05-15

    This paper details pulsed gradient NMR measurements of the {sup 3}He diffusion coefficient in sealed cells during spin exchange optical pumping. The potential of ultra low field magnetic resonance imgaing (MRI) and NMR for noninvasive measurement of cell pressure is demonstrated. Diffusion sensitization gradients allow measurement of the {sup 3}He diffusion coefficient from which the pressure and/or temperature of the gas can be determined during optical pumping. The pressure measurements were compared with neutron time of flight transmission measurements. Good agreement was observed between the temperature/pressure measurements and predictions based on Chapman-Enskog theory. The technique had sufficient sensitivity to observe the diffusion coefficient increasing with temperature in a sealed cell. With this method, evidence for laser heating of the {sup 3}He during optical pumping was found. The results show that NMR diffusion measurements allow noninvasive measurement of the cell temperature and/or pressure in an optical pumping setup. The method can be expanded using MRI to probe the spatial distribution of the diffusion coefficient. These techniques can be applied to the further investigation of polarization limiting effects such as laser heating.

  17. Thermal gradient-induced forces on geodetic reference masses for LISA

    E-Print Network [OSTI]

    L. Carbone; A. Cavalleri; G. Ciani; R. Dolesi; M. Hueller; D. Tombolato; S. Vitale; W. J. Weber

    2007-06-29

    The low frequency sensitivity of space-borne gravitational wave observatories will depend critically on the geodetic purity of the trajectories of orbiting test masses. Fluctuations in the temperature difference across the enclosure surrounding the free-falling test mass can produce noisy forces through several processes, including the radiometric effect, radiation pressure, and outgassing. We present here a detailed experimental investigation of thermal gradient-induced forces for the LISA gravitational wave mission and the LISA Pathfinder, employing high resolution torsion pendulum measurements of the torque on a LISA-like test mass suspended inside a prototype of the LISA gravitational reference sensor that will surround the test mass in orbit. The measurement campaign, accompanied by numerical simulations of the radiometric and radiation pressure effects, allows a more accurate and representative characterization of thermal-gradient forces in the specific geometry and environment relevant to LISA free-fall. The pressure dependence of the measured torques allows clear identification of the radiometric effect, in quantitative agreement with the model developed. In the limit of zero gas pressure, the measurements are most likely dominated by outgassing, but at a low level that does not threaten the LISA sensitivity goals.

  18. Latest Results of ILC High-Gradient R&D 9-cell Cavities at JLAB

    SciTech Connect (OSTI)

    Rongli Geng

    2008-02-11

    It has been over a year since JLAB started processing and testing ILC 9-cell cavities in the frame work of ILC high-gradient cavity R&D, aiming at the goal of a 35 MV/m gradient at a Q #4; of 1E10 with a yield of 90%. The necessary cavity processing steps include field flatness tuning, electropolishing (EP), hydrogen out-gassing under vacuum, high-pressure water rinsing, clean room assembly, and low temperature bake. These are followed by RF test at 2 Kelvin. Ultrasonic cleaning with Micro-90, an effective post-EP rinsing recipe discovered at JLAB, is routinely used. Seven industry manufactured 9-cell TESLAshape cavities are processed and tested repeatedly. So far, 33 EP cycles are accumulated, corresponding to more than 65 hours of active EP time. An emphasis put on RF testing is to discern cavity quench characteristics, including its nature and its location. Often times, the cavity performance is limited by thermal-magnetic quench instead of field emission. The quench field in some cavities is lower than 20 MV/m and remains unchanged despite repeated EP, implying material and/or fabrication defects. The quench field in some other cavities is high but changes unpredictably after repeated EP, suggesting processing induced defects. Based on our experience and results, several areas are identified where improvement is needed to improve cavity performance as well as yield.

  19. HIGH-GRADIENT, HIGH-TRANSFORMER-RATIO, DIELECTRIC WAKE FIELD ACCELERATOR

    SciTech Connect (OSTI)

    Jay L. Hirshfield

    2012-04-12

    The Phase I work reported here responds to DoE'ss stated need "...to develop improved accelerator designs that can provide very high gradient (>200 MV/m for electrons...) acceleration of intense bunches of particles." Omega-P'�s approach to this goal is through use of a ramped train of annular electron bunches to drive a coaxial dielectric wakefield accelerator (CDWA) structure. This approach is a direct extension of the CDWA concept from acceleration in wake fields caused by a single drive bunch, to the more efficient acceleration that we predict can be realized from a tailored (or ramped) train of several drive bunches. This is possible because of a much higher transformer ratio for the latter. The CDWA structure itself has a number of unique features, including: a high accelerating gradient G, potentially with G > 1 GeV/m; continuous energy coupling from drive to test bunches without transfer structures; inherent transverse focusing forces for particles in the accelerated bunch; highly stable motion of high charge annular drive bunches; acceptable alignment tolerances for a multi-section system. What is new in the present approach is that the coaxial dielectric structure is now to be energized by-not one-�but by a short train of ramped annular-shaped drive bunches moving in the outer coaxial channel of the structure. We have shown that this allows acceleration of an electron bunch traveling along the axis in the inner channel with a markedly higher transformer ratio T than for a single drive bunch. As described in this report, the structure will be a GHz-scale prototype with cm-scale transverse dimensions that is expected to confirm principles that can be applied to the design of a future THz-scale high gradient (> 500 MV/m) accelerator with mm-scale transverse dimensions. We show here a new means to significantly increase the transformer ratio T of the device, and thereby to significantly improve its suitability as a flexible and effective component in a future high energy, high gradient accelerator facility. We predict that the T of a high gradient CDWA can be increased by a substantial factor; this enhancement is dramatically greater than what has been demonstrated heretofore. This large enhancement in T that we predict arises from using a train of three or four drive bunches in which the spacing of the bunches and their respective charges are selected according to a simple principle that requires each bunch lose energy to the wakefields at the same rate, so as not to sacrifice drive beam efficiency�¢����as would be the case if one bunch exhausted its available energy while others had not. It is anticipated that results from the study proposed here can have a direct impact on design of the dielectric accelerator in a TeV-scale collider concept, and in the accelerator for an x-ray FEL.

  20. Convergence and Convergence Rate of Stochastic Gradient Search in the Case of Multiple and Non-Isolated Extrema

    E-Print Network [OSTI]

    Tadic, Vladislav B

    2009-01-01

    The asymptotic behavior of stochastic gradient algorithms is studied. Relying on some results of differential geometry (Lojasiewicz gradient inequality), the almost sure point-convergence is demonstrated and relatively tight almost sure bounds on the convergence rate are derived. In sharp contrast to all exiting result of this kind, the asymptotic results obtained here do not require the objective function (associated with the stochastic gradient search) to have an isolated minimum at which the Hessian of the objective function is strictly positive definite. Using the obtained results, the asymptotic behavior of recursive prediction error identification methods is analyzed. The convergence and convergence rate of supervised learning algorithms are also studied relying on these results.

  1. Determination of Reference Scales for Wilson Gauge Action from Yang--Mills Gradient Flow

    E-Print Network [OSTI]

    Masayuki Asakawa; Takumi Iritani; Masakiyo Kitazawa; Hiroshi Suzuki

    2015-10-08

    A parametrization of the lattice spacing ($a$) in terms of the bare coupling ($\\beta$) for the SU(3) Yang--Mills theory with the Wilson gauge action is given in a wide range of~$\\beta$. The Yang--Mills gradient flow with respect to the flow time~$t$ for the dimensionless observable, $t\\frac{d}{dt}t^2\\langle E(t)\\rangle$, is utilized to determine the parametrization. With fine lattice spacings ($6.3\\le\\beta\\le7.5$) and large lattice volumes ($N_{\\rm s}=64$--$128$), the discretization and finite-volume errors are significantly reduced to the same level as the statistical error.

  2. Dynamics of Air-Fluidized Granular System Measured by the Modulated Gradient Spin-echo

    E-Print Network [OSTI]

    Janez Stepisnik; Samo Lasic; Igor Sersa; Ales Mohoric; Gorazd Planinsic

    2005-10-05

    The power spectrum of displacement fluctuation of beads in the air-fluidized granular system is measured by a novel NMR technique of modulated gradient spin-echo. The results of measurement together with the related spectrum of the velocity fluctuation autocorrelation function fit well to an empiric formula based on to the model of bead caging between nearest neighbours; the cage breaks up after a few collisions \\cite{Menon1}. The fit yields the characteristic collision time, the size of bead caging and the diffusion-like constant for different degrees of system fluidization. The resulting mean squared displacement increases proportionally to the second power of time in the short-time ballistic regime and increases linearly with time in the long-time diffusion regime as already confirmed by other experiments and simulations.

  3. Optimization and analysis of experimental parameters for polarization gradient cooling of cold cesium atoms

    E-Print Network [OSTI]

    Ji, Zhonghua; Zhao, Yanting; Chang, Xuefang; Yang, Yonggang; Xiao, Liantuan; Jia, Suotang

    2013-01-01

    We systematically investigate the dependence of cold cesium atomic temperature in polarization gradient cooling (PGC) on experimental parameters, which contain change modes of cooling laser, interaction time, cooling laser frequency and its intensity. We find that the SR mode of cooling laser is the best for PGC, comparing SS, RS, RR modes. We put forward a statistical explanation and an exponential decay function to explain the variation of cold atomic temperature with the time. The heating effect is observed when the cooling laser intensity is lower than the saturation intensity of cold atoms. After optimization, the lowest temperature of cold cesium atoms is observed to be about 4uK with the number of 2x10^9 and a density of 5x10^10/cm^3. The optimization processes and analyses of controllable experimental parameters are also meaningful for other cold atomic systems.

  4. A second gradient theoretical framework for hierarchical multiscale modeling of materials

    SciTech Connect (OSTI)

    Luscher, Darby J; Bronkhorst, Curt A; Mc Dowell, David L

    2009-01-01

    A theoretical framework for the hierarchical multiscale modeling of inelastic response of heterogeneous materials has been presented. Within this multiscale framework, the second gradient is used as a non local kinematic link between the response of a material point at the coarse scale and the response of a neighborhood of material points at the fine scale. Kinematic consistency between these scales results in specific requirements for constraints on the fluctuation field. The wryness tensor serves as a second-order measure of strain. The nature of the second-order strain induces anti-symmetry in the first order stress at the coarse scale. The multiscale ISV constitutive theory is couched in the coarse scale intermediate configuration, from which an important new concept in scale transitions emerges, namely scale invariance of dissipation. Finally, a strategy for developing meaningful kinematic ISVs and the proper free energy functions and evolution kinetics is presented.

  5. A scaled gradient projection method for the X-ray imaging of solar flares

    E-Print Network [OSTI]

    Bonettini, S

    2013-01-01

    In this paper we present a new optimization algorithm for the reconstruction of X-ray images of solar flares by means of the data collected by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). The imaging concept of the satellite is based of rotating modulation collimator instruments, which allow the use of both Fourier imaging approaches and reconstruction techniques based on the straightforward inversion of the modulated count profiles. Although in the last decade a greater attention has been devoted to the former strategies due to their very limited computational cost, here we consider the latter model and investigate the effectiveness of a scaled gradient projection method for the solution of the corresponding constrained minimization problem. Moreover, regularization is introduced through either an early stopping of the iterative procedure, or a Tikhonov term added to the discrepancy function, by means of a discrepancy principle accounting for the Poisson nature of the noise affecting th...

  6. Wideband radar cross section reduction using two-dimensional phase gradient metasurfaces

    SciTech Connect (OSTI)

    Li, Yongfeng; Qu, Shaobo; Wang, Jiafu; Chen, Hongya; Zhang, Jieqiu; Xu, Zhuo; Zhang, Anxue

    2014-06-02

    Phase gradient metasurface (PGMs) are artificial surfaces that can provide pre-defined in-plane wave-vectors to manipulate the directions of refracted/reflected waves. In this Letter, we propose to achieve wideband radar cross section (RCS) reduction using two-dimensional (2D) PGMs. A 2D PGM was designed using a square combination of 49 split-ring sub-unit cells. The PGM can provide additional wave-vectors along the two in-plane directions simultaneously, leading to either surface wave conversion, deflected reflection, or diffuse reflection. Both the simulation and experiment results verified the wide-band, polarization-independent, high-efficiency RCS reduction induced by the 2D PGM.

  7. Equivalent Plastic Strain Gradient Plasticity with Grain Boundary Hardening and Comparison to Discrete Dislocation Dynamics

    E-Print Network [OSTI]

    Bayerschen, E; Wulfinghoff, S; Weygand, D; Böhlke, T

    2015-01-01

    The gradient crystal plasticity framework of Wulfinghoff et al. [53] incorporating an equivalent plastic strain and grain boundary yielding, is extended with additional grain boundary hardening. By comparison to averaged results from many discrete dislocation dynamics (DDD) simulations of an aluminum type tricrystal under tensile loading, the new hardening parameter in the continuum model is calibrated. It is shown that although the grain boundaries (GBs) in the discrete simulations are impenetrable, an infinite GB yield strength corresponding to microhard GB conditions, is not applicable in the continuum model. A combination of a finite GB yield strength with an isotropic bulk Voce hardening relation alone also fails to model the plastic strain profiles obtained by DDD. Instead, a finite GB yield strength in combination with GB hardening depending on the equivalent plastic strain at the GBs is shown to give a better agreement to DDD results. The differences in the plastic strain profiles obtained in DDD simu...

  8. GPU-Based Conjugate Gradient Solver for Lattice QCD with Domain-Wall Fermions

    E-Print Network [OSTI]

    Ting-Wai Chiu; Tung-Han Hsieh; Yao-Yuan Mao; Kenji Ogawa

    2011-01-02

    We present the first GPU-based conjugate gradient (CG) solver for lattice QCD with domain-wall fermions (DWF). It is well-known that CG is the most time-consuming part in the Hybrid Monte Carlo simulation of unquenched lattice QCD, which becomes even more computational demanding for lattice QCD with exact chiral symmetry. We have designed a CG solver for the general 5-dimensional DWF operator on NVIDIA CUDA architecture with mixed-precision, using the defect correction as well as the reliable updates algorithms. We optimize our computation by even-odd preconditioning in the 4D space-time lattice, plus several innovative techniques for CUDA kernels. For NVIDIA GeForce GTX 285/480, our CG solver attains 180/233 Gflops (sustained).

  9. GPU-Based Conjugate Gradient Solver for Lattice QCD with Domain-Wall Fermions

    E-Print Network [OSTI]

    Chiu, Ting-Wai; Mao, Yao-Yuan; Ogawa, Kenji

    2010-01-01

    We present the first GPU-based conjugate gradient (CG) solver for lattice QCD with domain-wall fermions (DWF). It is well-known that CG is the most time-consuming part in the Hybrid Monte Carlo simulation of unquenched lattice QCD, which becomes even more computational demanding for lattice QCD with exact chiral symmetry. We have designed a CG solver for the general 5-dimensional DWF operator on NVIDIA CUDA architecture with mixed-precision, using the defect correction as well as the reliable updates algorithms. We optimize our computation by even-odd preconditioning in the 4D space-time lattice, plus several innovative techniques for CUDA kernels. For NVIDIA GeForce GTX 285/480, our CG solver attains 180/233 Gflops (sustained).

  10. Can surface cracks and unipolar arcs explain breakdown and gradient limits?

    SciTech Connect (OSTI)

    Insepov, Zeke; Norem, Jim

    2013-01-15

    The authors argue that the physics of unipolar arcs and surface cracks can help understand rf breakdown and vacuum arc data. They outline a model of the basic mechanisms involved in breakdown and explore how the physics of unipolar arcs and cracks can simplify the picture of breakdown and gradient limits in accelerators, tokamaks as well as laser ablation, micrometeorites, and other applications. Cracks are commonly seen in SEM images of arc damage and they are produced as the liquid metal cools. They can produce the required field enhancements to explain field emission data and can produce mechanical failure of the surface that would trigger breakdown events. Unipolar arcs can produce currents sufficient to short out rf structures, and can cause the sort of damage seen in SEM images. They should be unstable, and possibly self-quenching, as seen in optical fluctuations and surface damage. The authors describe some details and consider the predictions of this simple model.

  11. Parallel conjugate gradient: effects of ordering strategies, programming paradigms, and architectural platforms

    SciTech Connect (OSTI)

    Oliker, L.; Li, X.; Heber, G.; Biswas, R.

    2000-05-01

    The Conjugate Gradient (CG) algorithm is perhaps the best-known iterative technique to solve sparse linear systems that are symmetric and positive definite. A sparse matrix-vector multiply (SPMV) usually accounts for most of the floating-point operations with a CG iteration. In this paper, we investigate the effects of various ordering and partitioning strategies on the performance of parallel CG and SPMV using different programming and architectures. Results show that for this class of applications, ordering significantly improves overall performance, that cache reuse may be more important than reducing communication, and that it is possible to achieve message passing performance using shared memory constructs through careful data ordering and distribution. However, a multithreaded implementation of CG on the Tera MTA does not require special ordering or partitioning to obtain high efficiency and scalability.

  12. Scaling of Macroscopic Properties of Porous Sediments Experiencing Compaction: Implications for Geothermal Gradient and Methane Inventory

    E-Print Network [OSTI]

    Goldobin, Denis S

    2011-01-01

    Porous sediments in geological systems experience stress by the above-laying mass and consequent compaction, which may be significantly nonuniform across the massif. We derive scaling laws for the compaction of sediments of similar geological origin. With these laws, we evaluate the dependence of the transport properties of a fluid-saturated porous medium (permeability, effective molecular diffusivity, hydrodynamic dispersion, and thermal conductivity) on its porosity. In particular, we demonstrate irrelevance of the assumption of a uniform geothermal gradient for systems with nonuniform compaction and importance of the derived scaling laws for mathematical modelling of methane hydrate deposits, which are believed to have potential for impact on global climate change and Glacial-Interglacial cycles.

  13. Non-equilibrium isothermal transformations in a temperature gradient from a microscopic dynamics

    E-Print Network [OSTI]

    Stefano Olla; Viviana Letizia

    2015-05-19

    We consider a chain of anharmonic oscillators immersed in a heat bath with a temperature gradient and a time varying tension applied to one end of the chain while the other side is fixed to a point. We prove that under diffusive space-time rescaling the volume strain distribution of the chain evolves following a non-linear diffusive equation. The stationary states of the dynamics are of non-equilibrium and have a positive entropy production, so the classical relative entropy methods cannot be used. We develop new estimates based on entropic hypocoercivity, that allows to control the distribution of the positions configurations of the chain. The macroscopic limit can be used to model isothermal thermodynamic transformations between non-equilibrium stationary states.

  14. Quasi-classical approximation in vortex filament dynamics. Integrable systems, gradient catastrophe and flutter

    E-Print Network [OSTI]

    B. G. Konopelchenko; G. Ortenzi

    2012-06-13

    Quasiclassical approximation in the intrinsic description of the vortex filament dynamics is discussed. Within this approximation the governing equations are given by elliptic system of quasi-linear PDEs of the first order. Dispersionless Da Rios system and dispersionless Hirota equation are among them. They describe motion of vortex filament with slow varying curvature and torsion without or with axial flow. Gradient catastrophe for governing equations is studied. It is shown that geometrically this catastrophe manifests as a fast oscillation of a filament curve around the rectifying plane which resembles the flutter of airfoils. Analytically it is the elliptic umbilic singularity in the terminology of the catastrophe theory. It is demonstrated that its double scaling regularization is governed by the Painleve' I equation.

  15. Standard test method for strain gradient measurements of thin, reflecting films using an optical interferometer

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 This test method covers a procedure for measuring the strain gradient in thin, reflecting films. It applies only to films, such as found in microelectromechanical systems (MEMS) materials, which can be imaged using an optical interferometer. Measurements from cantilevers that are touching the underlying layer are not accepted. 1.2 This test method uses a non-contact optical interferometer with the capability of obtaining topographical 3-D data sets. It is performed in the laboratory. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  16. Grain-scale thermoelastic stresses and spatiotemporal temperature gradients on airless bodies, implications for rock breakdown

    E-Print Network [OSTI]

    Molaro, Jamie L; Langer, Steve A

    2015-01-01

    Thermomechanical processes such as fatigue and shock have been suggested to cause and contribute to rock breakdown on Earth, and on other planetary bodies, particularly airless bodies in the inner solar system. In this study, we modeled grain-scale stresses induced by diurnal temperature variations on simple microstructures made of pyroxene and plagioclase on various solar system bodies. We found that a heterogeneous microstructure on the Moon experiences peak tensile stresses on the order of 100 MPa. The stresses induced are controlled by the coefficient of thermal expansion and Young's modulus of the mineral constituents, and the average stress within the microstructure is determined by relative volume of each mineral. Amplification of stresses occurs at surface-parallel boundaries between adjacent mineral grains and at the tips of pore spaces. We also found that microscopic spatial and temporal surface temperature gradients do not correlate with high stresses, making them inappropriate proxies for investig...

  17. Concentration of isotopic hydrogen by temperature gradient effect in soluble metal

    SciTech Connect (OSTI)

    Uhm, H.S.; Lee, W.W.

    1991-01-01

    This invention relates to the enrichment of isotopic hydrogen in a solid-state metal by use of temperature gradient effects, and is related to the subject matter disclosed in prior copending application Serial No. 07/724,083, filed July 1, 1991. High concentration of isotopic hydrogen in the form of deuterium atoms in a soluble metal such as palladium, is very useful for various electro-chemical studies including nuclear fusion investigations. A conventional technique used for deuterium enrichment purposes involves electrolysis, where a palladium rod is immersed in heavy water as the cathode. According to the prior copending application, aforementioned, deuterium density inside a palladium rod is increased by making use of plasma ion implantation. Patent Applications.

  18. Double-hybrid density-functional theory with meta-generalized-gradient approximations

    SciTech Connect (OSTI)

    Souvi, Sidi M. O. Sharkas, Kamal; Toulouse, Julien; CNRS, UMR 7616, Laboratoire de Chimie Théorique, F-75005 Paris

    2014-02-28

    We extend the previously proposed one-parameter double-hybrid density-functional theory [K. Sharkas, J. Toulouse, and A. Savin, J. Chem. Phys. 134, 064113 (2011)] to meta-generalized-gradient-approximation (meta-GGA) exchange-correlation density functionals. We construct several variants of one-parameter double-hybrid approximations using the Tao-Perdew-Staroverov-Scuseria (TPSS) meta-GGA functional and test them on test sets of atomization energies and reaction barrier heights. The most accurate variant uses the uniform coordinate scaling of the density and of the kinetic energy density in the correlation functional, and improves over both standard Kohn-Sham TPSS and second-order Møller-Plesset calculations.

  19. A model of the large hydraulic gradient at Yucca Mountain, Nevada Test Site, based on hydraulic conductivity contrasts between Cenozoic and Paleozoic rocks 

    E-Print Network [OSTI]

    Strom, Eric William

    1993-01-01

    gradient correlates well in several areas with the contacts between the underlying Paleozoic carbonates and an aquitard known as the Eleana Formation. This study investigates the possibility that the ground water flowing from the Cenozoic volcanics... Formation contact, a moderate gradient to the north, and a very small gradient to the south. ACKNOWLEDGMENTS I would like to thank Dr. Pat Domenico, the chair of my committee, for his ideas, and the knowledge of hydrogeology he has imparted to me...

  20. Accurate gradient approximation for complex interface problems in 3D by an improved coupling interface method

    SciTech Connect (OSTI)

    Shu, Yu-Chen, E-mail: ycshu@mail.ncku.edu.tw [Department of Mathematics, National Cheng Kung University, Tainan 701, Taiwan (China); Mathematics Division, National Center for Theoretical Sciences (South), Tainan 701, Taiwan (China); Chern, I-Liang, E-mail: chern@math.ntu.edu.tw [Department of Applied Mathematics, National Chiao Tung University, Hsin Chu 300, Taiwan (China); Department of Mathematics, National Taiwan University, Taipei 106, Taiwan (China); Mathematics Division, National Center for Theoretical Sciences (Taipei Office), Taipei 106, Taiwan (China); Chang, Chien C., E-mail: mechang@iam.ntu.edu.tw [Institute of Applied Mechanics, National Taiwan University, Taipei 106, Taiwan (China); Department of Mathematics, National Taiwan University, Taipei 106, Taiwan (China)

    2014-10-15

    Most elliptic interface solvers become complicated for complex interface problems at those “exceptional points” where there are not enough neighboring interior points for high order interpolation. Such complication increases especially in three dimensions. Usually, the solvers are thus reduced to low order accuracy. In this paper, we classify these exceptional points and propose two recipes to maintain order of accuracy there, aiming at improving the previous coupling interface method [26]. Yet the idea is also applicable to other interface solvers. The main idea is to have at least first order approximations for second order derivatives at those exceptional points. Recipe 1 is to use the finite difference approximation for the second order derivatives at a nearby interior grid point, whenever this is possible. Recipe 2 is to flip domain signatures and introduce a ghost state so that a second-order method can be applied. This ghost state is a smooth extension of the solution at the exceptional point from the other side of the interface. The original state is recovered by a post-processing using nearby states and jump conditions. The choice of recipes is determined by a classification scheme of the exceptional points. The method renders the solution and its gradient uniformly second-order accurate in the entire computed domain. Numerical examples are provided to illustrate the second order accuracy of the presently proposed method in approximating the gradients of the original states for some complex interfaces which we had tested previous in two and three dimensions, and a real molecule ( (1D63)) which is double-helix shape and composed of hundreds of atoms.

  1. Fast Ion Stabilization of the Ion Temperature Gradient Driven Modes in the Joint European Torus Hybrid-Scenario Plasmas: A Trigger Mechanism for Internal Transport Barrier Formation

    E-Print Network [OSTI]

    Fast Ion Stabilization of the Ion Temperature Gradient Driven Modes in the Joint European Torus Hybrid-Scenario Plasmas: A Trigger Mechanism for Internal Transport Barrier Formation

  2. Optimization of a Single Lithium-ion Battery Cell with a Gradient-based Algorithm , Wenbo Dua

    E-Print Network [OSTI]

    Papalambros, Panos

    Optimization of a Single Lithium-ion Battery Cell with a Gradient-based Algorithm Nansi Xuea for optimal cell designs are independent of discharge rate. Keywords Lithium ion battery Porous electrode for automating the design of lithium-ion cells to maximize cell energy density while meeting specific power

  3. Macroscopic description of microscopically strongly inhomogenous systems: A mathematical basis for the synthesis of higher gradients metamaterials

    E-Print Network [OSTI]

    Antonio Carcaterra; Francesco dell'Isola; Raffaele Esposito; Mario Pulvirenti

    2015-04-29

    We consider the time evolution of a one dimensional $n$-gradient continuum. Our aim is to construct and analyze discrete approximations in terms of physically realizable mechanical systems, called microscopic because they are living on a smaller space scale. We validate our construction by proving a convergence theorem of the microscopic system to the given continuum, as the scale parameter goes to zero.

  4. Dispersal and disease gradients of anther-smut (Ustilago violacea) infection of Silene alba at different life stages

    E-Print Network [OSTI]

    Roche, Bernadette M.; Alexander, Helen M.; Maltby, Arlan D.

    1995-09-01

    to vegetative plants, in small vials on the ground. Spore and disease gradients (number of spores or proportion of plants infected as a function of distance) were best fit with the classic power, Y = aD^-^b. The slope parameter, b, were similar for spore...

  5. Snow water equivalent along elevation gradients in the Merced and Tuolumne River basins of the Sierra Nevada

    E-Print Network [OSTI]

    Dozier, Jeff

    Snow water equivalent along elevation gradients in the Merced and Tuolumne River basins fractional snow-covered area (SCA) at 500 m resolution to estimate snow water equivalent (SWE) across) blending the fractional SCA with SWE interpolated from snow-pillow measurements; and (2) retrospectively

  6. Proposed structure for a crossed-laser beam, GeV per meter gradient, vacuum electron linear accelerator

    E-Print Network [OSTI]

    Byer, Robert L.

    Proposed structure for a crossed-laser beam, GeV per meter gradient, vacuum electron linear We propose a dielectric-based, multistaged, laser-driven electron linear accelerator structure operating in a vacuum that is capable of accelerating electrons to 1 TeV in 1 km. Our study shows that a Ge

  7. Boosting the voltage of a salinity-gradient-power electrochemical cell by means of complex-forming solutions

    E-Print Network [OSTI]

    Carati, Andrea

    Boosting the voltage of a salinity-gradient-power electrochemical cell by means of complex to the formation of complexes. We present the results of a cell for power produc- tion, which has excellent-based light-emitting electrochemical cells J. Appl. Phys. 116, 104504 (2014); 10.1063/1.4895060 Decoupled

  8. Stability of black carbon in soils across a climatic gradient Chih-Hsin Cheng,1,2

    E-Print Network [OSTI]

    Lehmann, Johannes

    5 March 2008; published 4 June 2008. [1] The recalcitrant properties of black carbon (BC) grant carbon dioxide in soils [Lehmann et al., 2006; Lehmann, 2007a, 2007b]. [3] However, the notionStability of black carbon in soils across a climatic gradient Chih-Hsin Cheng,1,2 Johannes Lehmann

  9. 3D Controlled Motion of a Microrobot using Magnetic Gradients Karim Belharet, David Folio and Antoine Ferreira

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    3D Controlled Motion of a Microrobot using Magnetic Gradients Karim Belharet, David Folio to allow 3D navigation of a microdevice in blood vessels, namely: (i) vessel path extraction, (ii) magnetic locations in the human body become accessible. Because the method of propulsion should al- low

  10. Large deviations in stochastic heat-conduction processes provide a gradient-flow structure for heat conduction

    SciTech Connect (OSTI)

    Peletier, Mark A., E-mail: m.a.peletier@tue.nl [Department of Mathematics and Computer Science and Institute for Complex Molecular Systems, Technische Universiteit Eindhoven, Postbus 513, 5600 MB Eindhoven (Netherlands); Redig, Frank, E-mail: f.h.j.redig@tudelft.nl [Delft Institute of Applied Mathematics, Technische Universiteit Delft, Mekelweg 4, 2628 CD Delft (Netherlands); Vafayi, Kiamars, E-mail: k.vafayi@tue.nl [Department of Mathematics and Computer Science, Technische Universiteit Eindhoven, Postbus 513, 5600 MB Eindhoven (Netherlands)

    2014-09-01

    We consider three one-dimensional continuous-time Markov processes on a lattice, each of which models the conduction of heat: the family of Brownian Energy Processes with parameter m (BEP(m)), a Generalized Brownian Energy Process, and the Kipnis-Marchioro-Presutti (KMP) process. The hydrodynamic limit of each of these three processes is a parabolic equation, the linear heat equation in the case of the BEP(m) and the KMP, and a nonlinear heat equation for the Generalized Brownian Energy Process with parameter a (GBEP(a)). We prove the hydrodynamic limit rigorously for the BEP(m), and give a formal derivation for the GBEP(a). We then formally derive the pathwise large-deviation rate functional for the empirical measure of the three processes. These rate functionals imply gradient-flow structures for the limiting linear and nonlinear heat equations. We contrast these gradient-flow structures with those for processes describing the diffusion of mass, most importantly the class of Wasserstein gradient-flow systems. The linear and nonlinear heat-equation gradient-flow structures are each driven by entropy terms of the form -log ?; they involve dissipation or mobility terms of order ?² for the linear heat equation, and a nonlinear function of ? for the nonlinear heat equation.

  11. Concentrating colloids with electric field gradients. II. Phase transitions and crystal buckling of long-ranged repulsive charged spheres

    E-Print Network [OSTI]

    Leunissen, Mirjam

    Concentrating colloids with electric field gradients. II. Phase transitions and crystal buckling of the particle concentration in suspensions of charged colloids, which have long-ranged repulsive interactions the initial fluid phase to a random hexagonal close-packed crystal, as well as a body-centered cubic crystal

  12. Localised mobilisation of metals, as measured by diffusive gradients in thin-films, in soil historically treated with sewage sludge

    E-Print Network [OSTI]

    Ma, Lena

    historically treated with sewage sludge Jun Luo a,c , Hao Zhang a, , William Davison a , Ronald G. McLaren b online 11 September 2012 Keywords: Trace metals Soil Sewage sludge Mn oxide Diffusive gradients in thin was investigated in a sandy loam soil historically treated with sewage sludge. After deployment of two DGT

  13. Assessment of plasma impedance probe for measuring electron density and collision frequency in a plasma with spatial and temporal gradients

    SciTech Connect (OSTI)

    Hopkins, Mark A. King, Lyon B.

    2014-05-15

    Numerical simulations and experimental measurements were combined to determine the ability of a plasma impedance probe (PIP) to measure plasma density and electron collision frequency in a plasma containing spatial gradients as well as time-varying oscillations in the plasma density. A PIP is sensitive to collision frequency through the width of the parallel resonance in the Re[Z]-vs.-frequency characteristic, while also being sensitive to electron density through the zero-crossing of the Im[Z]-vs.-frequency characteristic at parallel resonance. Simulations of the probe characteristic in a linear plasma gradient indicated that the broadening of Re[Z] due to the spatial gradient obscured the broadening due to electron collision frequency, preventing a quantitative measurement of the absolute collision frequency for gradients considered in this study. Simulation results also showed that the PIP is sensitive to relative changes in electron collision frequency in a spatial density gradient, but a second broadening effect due to time-varying oscillations made collision frequency measurements impossible. The time-varying oscillations had the effect of causing multiple zero-crossings in Im[Z] at parallel resonance. Results of experiments and simulations indicated that the lowest-frequency zero-crossing represented the lowest plasma density in the oscillations and the highest-frequency zero-crossing represented the highest plasma density in the oscillations, thus the PIP probe was found to be an effective tool to measure both the average plasma density as well as the maximum and minimum densities due to temporal oscillations.

  14. Electric-field gradients at the Zr sites in Zr3Fe: Measured using perturbed-angular-correlation spectroscopy and calculated using band theory

    E-Print Network [OSTI]

    Motta, Arthur T.

    Electric-field gradients at the Zr sites in Zr3Fe: Measured using perturbed-angular-correlation spectroscopy and calculated using band theory Arthur T. Motta, Stephen E. Cumblidge, and Gary L. Catchen; published 13 December 2001 We have measured the electric-field-gradient EFG parameters VZZ

  15. Enhancement of laser cooling by the use of magnetic gradients This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Wunderlich, Christof

    Enhancement of laser cooling by the use of magnetic gradients This article has been downloaded from cooling by the use of magnetic gradients A Albrecht1,3 , A Retzker1 , C Wunderlich2 and M B Plenio1 1.1088/1367-2630/13/3/033009 Abstract. We present a laser cooling scheme for trapped ions and atoms using a combination of laser

  16. Eddy currents in a transverse MRI gradient coil. J.M.B. Kroot, S.J.L. van Eijndhoven, A.A.F. van de Ven

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    Eddy currents in a transverse MRI gradient coil. J.M.B. Kroot, S.J.L. van Eijndhoven, A.A.F. van de logarithmically singular kernel represents inductive effects related to the occurrence of eddy currents on the development of eddy currents in the gradient coils, which have a negative effect on the uniformity

  17. Investigations of Atmospheric and Plant Physiological Effects along an Urban-To-Rural Gradient in the Houston Metropolitan Area Comparing 2011 to 2012 

    E-Print Network [OSTI]

    Gramann, Jonathan

    2014-09-02

    to rural trees. To study this, an urban0to-rural gradient was set up starting near downtown Houston, TX, and extending north approximately 90 km. Three weather stations were erected along this gradient to continually monitor weather. Photosynthesis rates...

  18. Gradient damage models and their use to approximate brittle fracture Kim Phama,b, Hanen Amorc,, Jean-Jacques Marigod, Corrado Maurinia,b,

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Gradient damage models and their use to approximate brittle fracture Kim Phama,b, Hanen Amorc of gradient damage models. In the present paper, we first formulate the quasi-static evolution problem of damage. These concepts are applied in the particular setting of a one-dimensional traction test

  19. Mechanical and Aerospace Engineering Tempe, Arizona 85287-6106

    E-Print Network [OSTI]

    turbulence. 1. INTRODUCTION Establishing the origins of turbulent flow and transition from laminar to turbulent flow remains an important challenge for fluid mechanics. The common thread connecting aerodynamic the initial condi- tions of disturbance amplitude, frequency, and phase for the breakdown of laminar flow

  20. Attach A to Sample Subcontract - Temp Employee Cost Breakout...

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

    5 9900 5.5 Secretary l 1 1980 5.6 Secretary ll 21 41580 5.7 Secretary lll 2 3960 5.8 Accounting Clerk I 1 1980 5.9 Accounting Clerk II 7 13860 5.1 Accounting Clerk III 3 5940...

  1. Mechanical and Aerospace Engineering Tempe, Arizona 85287-6106

    E-Print Network [OSTI]

    . The material focuses on the crossflow instability that leads to transition on swept wings and rotating disks. Following a brief overview of instability mechanisms and the crossflow problem, a summary of the important geometries are covered. This historical account and literature survey of the crossflow instability are used

  2. Temp Exemption Chap. II - Nevada U1a

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    Temporary relief from DOE O 420.1B requirement of Automatic Fire Suppression in Area 1 of the U1a Complex at the Nevada National Security Site.

  3. C:\\Temp_jhd\\spacers\\spacers_wa_2014.prn

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

    at time of production. It does not represent any legal information or boundaries. BPA GIS Database, 2013. 0 10 20 30 40 Miles N January 27, 2014 bud.bpa.govwggisgisdata2...

  4. C:\\Temp_jhd\\spacers\\spacers_or_2014.prn

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

    created with best available data at time of production. It does not represent any legal information or boundaries. BPA GIS Database, 2013. 0 10 20 30 40 Miles N January 27, 2014...

  5. Property:MeanReservoirTemp | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History ViewMayo,AltFuelVehicle2 Jump to: navigation, searchContDiv JumpTechDsc JumpLabVelocity

  6. Microsoft Word - Final Temp Route _9_23_08_

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on77 PAGE OF PAGESpersonal CERTIFIED MAIL October

  7. Microsoft Word - RFP505545 - Temp Services Personnel FINAL- R2

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on77 PAGE OFDetection of Hydrates on

  8. Property:GeochemReservoirTemp | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to: navigation,Property EditMimeType JumpFuturePlansActionableEntity

  9. Property:SanyalTempReservoir | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EA EIS Report Url Jump to:ProgrammableYear Jump to:

  10. Low-Temp Success Stories | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i nAand DOE Safetyof Energy This Revision 3 of the Low-Level WasteJuly 2,

  11. C:\WINDOWS\Temp\agreementtomediate.PDF | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i n c i p a l DeInsulation at

  12. Kalex Advanced Low Temp Geothemal Power Cycle | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCED MANUFACTURING OFFICE INDUSTRIALU.S. DepartmentJean SeibertJulie CrenshawWestKahuku Wind to

  13. Magnetization Oscillation of a Spinor Condensate Induced by Magnetic Field Gradient

    E-Print Network [OSTI]

    Jie Zhang; Baoguo Yang; Yunbo Zhang

    2011-05-02

    We study the spin mixing dynamics of ultracold spin-1 atoms in a weak non-uniform magnetic field with field gradient $G$, which can flip the spin from +1 to -1 so that the magnetization $m=\\rho_{+}-\\rho_{-}$ is not any more a constant. The dynamics of $m_F=0$ Zeeman component $\\rho_{0}$, as well as the system magnetization $m$, are illustrated for both ferromagnetic and polar interaction cases in the mean-field theory. We find that the dynamics of system magnetization can be tuned between the Josephson-like oscillation similar to the case of double well, and the interesting self-trapping regimes, i.e. the spin mixing dynamics sustains a spontaneous magnetization. Meanwhile the dynamics of $\\rho_0$ may be sufficiently suppressed for initially imbalanced number distribution in the case of polar interaction. A "beat-frequency" oscillation of the magnetization emerges in the case of balanced initial distribution for polar interaction, which vanishes for ferromagnetic interaction.

  14. Theory of factors limiting high gradient operation of warm accelerating structures

    SciTech Connect (OSTI)

    Nusinovich, Gregory S.; Antonsen, Thomas M.; Kishek, Rami

    2014-07-25

    This final report summarizes the research performed during the time period from 8/1/2010 to 7/31/2013. It consists of two parts describing our studies in two directions: (a) analysis of factors limiting operation of dielectric-loaded accelerating (DLA) structures where the main problem is the occurrence of multipactor on dielectric surfaces, and (b) studies of effects associated with either RF magnetic or RF electric fields which may cause the RF breakdown in high-gradient metallic accelerating structures. In the studies of DLA structures, at least, two accomplishments should be mentioned: the development of a 3D non-stationary, self-consistent code describing the multipactor phenomena and yielding very good agreement with some experimental data obtained in joint ANL/NRL experiments. In the metallic structures, such phenomena as the heating and melting of micro-particles (metallic dust) by RF electric and magnetic fields in single-shot and rep-rate regimes is analyzed. Also, such processes in micro-protrusions on the structure surfaces as heating and melting due to the field emitted current and the Nottingham effect are thoroughly investigated with the account for space charge of emitted current on the field emission from the tip.

  15. Standard Test Method for Measuring Heat Flux Using Flush-Mounted Insert Temperature-Gradient Gages

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This test method describes the measurement of the net heat flux normal to a surface using gages inserted flush with the surface. The geometry is the same as heat-flux gages covered by Test Method E 511, but the measurement principle is different. The gages covered by this standard all use a measurement of the temperature gradient normal to the surface to determine the heat that is exchanged to or from the surface. Although in a majority of cases the net heat flux is to the surface, the gages operate by the same principles for heat transfer in either direction. 1.2 This general test method is quite broad in its field of application, size and construction. Two different gage types that are commercially available are described in detail in later sections as examples. A summary of common heat-flux gages is given by Diller (1). Applications include both radiation and convection heat transfer. The gages used for aerospace applications are generally small (0.155 to 1.27 cm diameter), have a fast time response ...

  16. Scrape-off Layer Flows With Pressure Gradient Scale Length ~ {rho}{sub p}

    SciTech Connect (OSTI)

    Robert J. Goldston

    2013-03-08

    A heuristic model for the plasma scrape-off width balances magnetic drifts against parallel loss at c{sub s} /2, resulting in a SOL width ~ {rho}{sub p}. T{sub sep} is calculated from Spitzer–Härm parallel thermal conduction. This results in a prediction for the power scrape-off width in quantitative agreement both in magnitude and scaling with recent experimental data. To achieve the ~ c{sub s} /2 flow assumed in this model and measured experimentally sets requirements on the ratio of upstream to total SOL particle sources, relative to the square-root of the ratio of target to upstream temperature. The Pfisch-Schlüter model for equilibrium flows has been modified to allow near-sonic flows, appropriate for gradient scale lengths of order {rho}{sub p}, resulting in a new quadrupole radial flow pattern. The strong parallel flows and plasma charging implied by this model suggest a mechanism for H-mode transition, consistent with many observations

  17. Thermally-assisted-occupation density functional theory with generalized-gradient approximations

    SciTech Connect (OSTI)

    Chai, Jeng-Da

    2014-05-14

    We extend the recently proposed thermally-assisted-occupation density functional theory (TAO-DFT) [J.-D. Chai, J. Chem. Phys. 136, 154104 (2012)] to generalized-gradient approximation (GGA) exchange-correlation density functionals. Relative to our previous TAO-LDA (i.e., the local density approximation to TAO-DFT), the resulting TAO-GGAs are significantly superior for a wide range of applications, such as thermochemistry, kinetics, and reaction energies. For noncovalent interactions, TAO-GGAs with empirical dispersion corrections are shown to yield excellent performance. Due to their computational efficiency for systems with strong static correlation effects, TAO-LDA and TAO-GGAs are applied to study the electronic properties (e.g., the singlet-triplet energy gaps, vertical ionization potentials, vertical electron affinities, fundamental gaps, and symmetrized von Neumann entropy) of acenes with different number of linearly fused benzene rings (up to 100), which is very challenging for conventional electronic structure methods. The ground states of acenes are shown to be singlets for all the chain lengths studied here. With the increase of acene length, the singlet-triplet energy gaps, vertical ionization potentials, and fundamental gaps decrease monotonically, while the vertical electron affinities and symmetrized von Neumann entropy (i.e., a measure of polyradical character) increase monotonically.

  18. Tecuamburro Volcano, Guatemala geothermal gradient core hole drilling, operations, and preliminary results

    SciTech Connect (OSTI)

    Goff, S.; Heiken, G.; Goff, F.; Gardner, J. (Los Alamos National Lab., NM (USA)); Duffield, W. (Geological Survey, Flagstaff, AZ (USA)); Martinelli, L.; Aycinena, S. (Swissboring Overseas Corp. Ltd., Guatemala City (Guatemala)); Castaneda, O. (Unidad de Desarrollo Geotermico, Guatemala City (Guatemala). Inst. Nacional de Electrificacion)

    1990-01-01

    A geothermal gradient core hole (TCB-1) was drilled to a depth of 700+ m at the Tecuamburro geothermal site, Guatemala during February and March, 1990. The core hole is located low on the northern flank of the Tecuamburro Volcano complex. Preliminary analysis of cores (>98% core recovery) indicates that the hydrothermal system may be centered in the 4-km-diameter Chupadero Crater, which has been proposed as the source of pyroxene pumice deposits in the Tecuamburro area. TCB-1 is located 300 m south of a 300-m-diameter phreatic crater, Laguna Ixpaco; the core hole penetrates the thin edge of a tuff ring surrounding Ixpaco and zones of hydrothermal brecciation within the upper 150 m may be related to the phreatic blast, dated at 2,910 {sup 14}C years. At the time of this writing, the unequilibrated temperature at a depth of 570m was 180{degree}C. Data on fracturing, permeability, hydrothermal alteration, and temperature will be presented. 3 refs., 3 figs.

  19. A Gradient Descent Approach to Optimal Coherent Quantum LQG Controller Design

    E-Print Network [OSTI]

    Arash Kh. Sichani; Igor G. Vladimirov; Ian R. Petersen

    2015-02-01

    This paper is concerned with the Coherent Quantum Linear Quadratic Gaussian (CQLQG) control problem of finding a stabilizing measurement-free quantum controller for a quantum plant so as to minimize an infinite-horizon mean square performance index for the fully quantum closed-loop system. In comparison with the observation-actuation structure of classical controllers, the coherent quantum feedback is less invasive to the quantum dynamics and quantum information. Both the plant and the controller are open quantum systems whose dynamic variables satisfy the canonical commutation relations (CCRs) of a quantum harmonic oscillator and are governed by linear quantum stochastic differential equations (QSDEs). In order to correspond to such oscillators, these QSDEs must satisfy physical realizability (PR) conditions, which are organised as quadratic constraints on the controller matrices and reflect the preservation of CCRs in time. The CQLQG problem is a constrained optimization problem for the steady-state quantum covariance matrix of the plant-controller system satisfying an algebraic Lyapunov equation. We propose a gradient descent algorithm equipped with adaptive stepsize selection for the numerical solution of the problem. The algorithm finds a local minimum of the LQG cost over the parameters of the Hamiltonian and coupling operators of a stabilizing PR quantum controller, thus taking the PR constraints into account. A convergence analysis of the proposed algorithm is presented. A numerical example of a locally optimal CQLQG controller design is provided to demonstrate the algorithm performance.

  20. The application of projected conjugate gradient solvers on graphical processing units

    SciTech Connect (OSTI)

    Lin, Youzuo [Los Alamos National Laboratory; Renaut, Rosemary [ARIZONA STATE UNIV.

    2011-01-26

    Graphical processing units introduce the capability for large scale computation at the desktop. Presented numerical results verify that efficiencies and accuracies of basic linear algebra subroutines of all levels when implemented in CUDA and Jacket are comparable. But experimental results demonstrate that the basic linear algebra subroutines of level three offer the greatest potential for improving efficiency of basic numerical algorithms. We consider the solution of the multiple right hand side set of linear equations using Krylov subspace-based solvers. Thus, for the multiple right hand side case, it is more efficient to make use of a block implementation of the conjugate gradient algorithm, rather than to solve each system independently. Jacket is used for the implementation. Furthermore, including projection from one system to another improves efficiency. A relevant example, for which simulated results are provided, is the reconstruction of a three dimensional medical image volume acquired from a positron emission tomography scanner. Efficiency of the reconstruction is improved by using projection across nearby slices.

  1. Proof of Concept Thin Films and Multilayers Toward Enhanced Field Gradients in SRF Cavities

    SciTech Connect (OSTI)

    Lukaszew, R A; Beringer, D; Roach, W M; Eremeev, G V; Valente-Feliciano, A-M; Reece, C E; Xi, X

    2013-09-01

    Due to the very shallow penetration depth of the RF fields, SRF properties are inherently a surface phenomenon involving a material thickness of less than 1 micron thus opening up the possibility of using thin film coatings to achieve a desired performance. The challenge has been to understand the dependence of the SRF properties on the detailed characteristics of real surfaces and then to employ appropriate techniques to tailor these surface properties for greatest benefit. Our aim is to achieve gradients >100 MV/m and no simple material is known to be capable of sustaining this performance. A theoretical framework has been proposed which could yield such behavior [1] and it requires creation of thin film layered structures. I will present our systematic studies on such proof-of-principle samples. Our overarching goal has been to build a basic understanding of key nano-scale film growth parameters for materials that show promise for SRF cavity multilayer coatings and to demonstrate the ability to elevate the barrier for vortex entry in such layered structures above the bulk value of Hc1 for type-II superconductors and thus to sustain higher accelerating fields.

  2. The VMC survey. XI. Radial stellar population gradients in the galactic globular cluster 47 Tucanae

    SciTech Connect (OSTI)

    Li, Chengyuan; De Grijs, Richard; Deng, Licai; Rubele, Stefano; Girardi, Leo; Gullieuszik, Marco; Wang, Chuchu; Bekki, Kenji; For, Bi-Qing; Cioni, Maria-Rosa L.; Clementini, Gisella; Emerson, Jim; Groenewegen, Martin A. T.; Guandalini, Roald; Marconi, Marcella; Ripepi, Vincenzo; Piatti, Andrés E.; Van Loon, Jacco Th. E-mail: grijs@pku.edu.cn

    2014-07-20

    We present a deep near-infrared color-magnitude diagram of the Galactic globular cluster 47 Tucanae, obtained with the Visible and Infrared Survey Telescope for Astronomy (VISTA) as part of the VISTA near-infrared Y, J, K{sub s} survey of the Magellanic System (VMC). The cluster stars comprising both the subgiant and red giant branches exhibit apparent, continuous variations in color-magnitude space as a function of radius. Subgiant branch stars at larger radii are systematically brighter than their counterparts closer to the cluster core; similarly, red-giant-branch stars in the cluster's periphery are bluer than their more centrally located cousins. The observations can very well be described by adopting an age spread of ?0.5 Gyr as well as radial gradients in both the cluster's helium abundance (Y) and metallicity (Z), which change gradually from (Y = 0.28, Z = 0.005) in the cluster core to (Y = 0.25, Z = 0.003) in its periphery. We conclude that the cluster's inner regions host a significant fraction of second-generation stars, which decreases with increasing radius; the stellar population in the 47 Tuc periphery is well approximated by a simple stellar population.

  3. Exclusion of cosmic rays in protoplanetary disks. II. Chemical gradients and observational signatures

    SciTech Connect (OSTI)

    Cleeves, L. Ilsedore; Bergin, Edwin A.; Adams, Fred C. [Department of Astronomy, University of Michigan, 1085 South University Avenue, Ann Arbor, MI 48109 (United States)

    2014-10-20

    The chemical properties of protoplanetary disks are especially sensitive to their ionization environment. Sources of molecular gas ionization include cosmic rays (CRs), stellar X-rays, and short-lived radionuclides, each of which varies with location in the disk. This behavior leads to a significant amount of chemical structure, especially in molecular ion abundances, which is imprinted in their submillimeter rotational line emission. Using an observationally motivated disk model, we make predictions for the dependence of chemical abundances on the assumed properties of the ionizing field. We calculate the emergent line intensity for abundant molecular ions and simulate sensitive observations with the Atacama Large Millimeter/Sub-millimeter Array (ALMA) for a disk at D = 100 pc. The models readily distinguish between high ionization rates (? ? 10{sup –17} s{sup –1} per H{sub 2}) and below, but it becomes difficult to distinguish between low ionization models when ? ? 10{sup –19} s{sup –1}. We find that H{sub 2}D{sup +} emission is not detectable for sub-interstellar CR rates with ALMA (6h integration), and that N{sub 2}D{sup +} emission may be a more sensitive tracer of midplane ionization. HCO{sup +} traces X-rays and high CR rates (?{sub CR} ? 10{sup –17} s{sup –1}), and provides a handle on the warm molecular ionization properties where CO is present in the gas. Furthermore, species like HCO{sup +}, which emits from a wide radial region and samples a large gradient in temperature, can exhibit ring-like emission as a consequence of low-lying rotational level de-excitation near the star. This finding highlights a scenario where rings are not necessarily structural or chemical in nature, but simply a result of the underlying line excitation properties.

  4. Gradient Analysis and Classification of Carolina Bay Vegetation: A Framework for Bay Wetlands Conservation and Restoration

    SciTech Connect (OSTI)

    Diane De Steven,Ph.D.; Maureen Tone,PhD.

    1997-10-01

    This report address four project objectives: (1) Gradient model of Carolina bay vegetation on the SRS--The authors use ordination analyses to identify environmental and landscape factors that are correlated with vegetation composition. Significant factors can provide a framework for site-based conservation of existing diversity, and they may also be useful site predictors for potential vegetation in bay restorations. (2) Regional analysis of Carolina bay vegetation diversity--They expand the ordination analyses to assess the degree to which SRS bays encompass the range of vegetation diversity found in the regional landscape of South Carolina's western Upper Coastal Plain. Such comparisons can indicate floristic status relative to regional potentials and identify missing species or community elements that might be re-introduced or restored. (3) Classification of vegetation communities in Upper Coastal Plain bays--They use cluster analysis to identify plant community-types at the regional scale, and explore how this classification may be functional with respect to significant environmental and landscape factors. An environmentally-based classification at the whole-bay level can provide a system of templates for managing bays as individual units and for restoring bays to desired plant communities. (4) Qualitative model for bay vegetation dynamics--They analyze present-day vegetation in relation to historic land uses and disturbances. The distinctive history of SRS bays provides the possibility of assessing pathways of post-disturbance succession. They attempt to develop a coarse-scale model of vegetation shifts in response to changing site factors; such qualitative models can provide a basis for suggesting management interventions that may be needed to maintain desired vegetation in protected or restored bays.

  5. Effects of 3D Geometries on Cellular Gradient Sensing and Polarization

    E-Print Network [OSTI]

    Fabian Spill; Vivi Andasari; Michael Mak; Roger D. Kamm; Muhammad H. Zaman

    2015-08-12

    During cell migration, cells become polarized, change their shape, and move in response to various cues, both internal and external. Many existing mathematical models of cell polarization are formulated in one or two spatial dimensions and hence cannot accurately capture the effect of cell shape, as well as the response of the cell to signals from different directions in a three-dimensional environment. To study those effects, we introduce a three-dimensional reaction-diffusion model of a cell. As some key molecules in cell polarization, such as the small GTPases, can exist both membrane bound and soluble in the cytosol, we first look at the role of cell geometry on the membrane binding/unbinding dynamics of such molecules. We derive quite general conditions under which effective existing one or two-dimensional computational models are valid, and find novel renormalizations of parameters in the effective model. We then extend an established one-dimensional cell polarization pathway in our three-dimensional framework. Our simulations indicate that even in some quasi-one-dimensional scenarios, such as polarization of a cell along a linear growth factor gradient, the cell shape can influence the polarization behavior of the cell, with cells of some shape polarizing more efficiently than those of other shapes. We also investigate the role of the previously ignored membrane unbinding rate on polarization. Furthermore, we simulate the response of the cell when the external signal is changing directions, and we find that more symmetric cells can change their polarized state more effectively towards the new stimulus than cells which are elongated along the direction of the original stimulus.

  6. Geothermal Resource/Reservoir Investigations Based on Heat Flow and Thermal Gradient Data for the United States

    SciTech Connect (OSTI)

    D. D. Blackwell; K. W. Wisian; M. C. Richards; J. L. Steele

    2000-04-01

    Several activities related to geothermal resources in the western United States are described in this report. A database of geothermal site-specific thermal gradient and heat flow results from individual exploration wells in the western US has been assembled. Extensive temperature gradient and heat flow exploration data from the active exploration of the 1970's and 1980's were collected, compiled, and synthesized, emphasizing previously unavailable company data. Examples of the use and applications of the database are described. The database and results are available on the world wide web. In this report numerical models are used to establish basic qualitative relationships between structure, heat input, and permeability distribution, and the resulting geothermal system. A series of steady state, two-dimensional numerical models evaluate the effect of permeability and structural variations on an idealized, generic Basin and Range geothermal system and the results are described.

  7. Laser-Doppler acoustic probing of granular media with in-depth property gradient and varying pore pressures

    SciTech Connect (OSTI)

    Bodet, L.; Dhemaied, A.; Mourgues, R.; Tournat, V.; Rejiba, F.

    2012-05-24

    Non-contacting ultrasonic techniques recently proved to be efficient in the physical modeling of seismic-wave propagation at various application scales, as for instance in the context of geological analogue and seismic modeling. An innovative experimental set-up is proposed here to perform laser-Doppler acoustic probing of unconsolidated granular media with varying pore pressures. The preliminary experiments presented here provide reproducible results and exploitable data, thus validating both the proposed medium preparation and pressure gradient generation procedure.

  8. SU-E-T-262: Planning for Proton Pencil Beam Scanning (PBS): Applications of Gradient Optimization for Field Matching

    SciTech Connect (OSTI)

    Lin, H; Kirk, M; Zhai, H; Ding, X; Liu, H; Hill-Kayser, C; Lustig, R; Tochner, Z; Deville, C; Vapiwala, N; McDonough, J; Both, S [University Pennsylvania, Philadelphia, PA (United States)

    2014-06-01

    Purpose: To propose the gradient optimization(GO) approach in planning for matching proton PBS fields and present two commonly used applications in our institution. Methods: GO is employed for PBS field matching in the scenarios that when the size of the target is beyond the field size limit of the beam delivery system or matching is required for beams from different angles to either improve the sparing of important organs or to pass through a short and simple beam path. Overlap is designed between adjacent fields and in the overlapped junction, the dose was optimized such that it gradually decreases in one field and the decrease is compensated by increase from another field. Clinical applications of this approach on craniospinal irradiation(CSI) and whole pelvis treatment were presented. Mathematical model was developed to study the relationships between dose errors, setup errors and junction lengths. Results: Uniform and conformal dose coverage to the entire target volumes was achieved for both applications using GO approach. For CSI, the gradient matching (6.7cm junction) between fields overcame the complexity of planning associated with feathering match lines. A slow dose gradient in the junction area significantly reduced the sensitivity of the treatment to setup errors. For whole pelvis, gradient matching (4cm junction) between posterior fields for superior target and bilateral fields for inferior target provided dose sparing to organs such as bowel, bladder and rectum. For a setup error of 3 mm in longitudinal direction from one field, mathematical model predicted dose errors of 10%, 6% and 4.3% for junction length of 3, 5 and 7cm. Conclusion: This GO approach improves the quality of the PBS treatment plan with matching fields while maintaining the safety of treatment delivery relative to potential misalignments.

  9. Vertical distribution of larval stages of the horn fly, Haematobia irritans irritans (L.), in relation to manure pat temperature gradients 

    E-Print Network [OSTI]

    March, Philip Anderson

    1981-01-01

    control strategists to recommend the mechanical destruction of the intact manure pat by harrowing (Smith 1889). Mariatt ( 1910) suggested placement of swine in cattle pastures to achieve the same purpose. Rapid dessication of the scattered manure...VERTICAL DISTRISUTION OF LARVAL STAGES OF THE HORN FLY, HAEMATOBIA IRRITANS IRRITANS (L. ), IN RELATION TO MANURE PAT TEMPERATURE GRADIENTS A Thesis by PHILIP ANDERSON MARCH Submitted to the Graduate College of Texas AijM University...

  10. A dislocation-based, strain–gradient–plasticity strengthening model for deformation processed metal–metal composites

    SciTech Connect (OSTI)

    Tian, Liang; Russell, Alan; Anderson, Iver

    2014-01-03

    Deformation processed metal–metal composites (DMMCs) are high-strength, high-electrical conductivity composites developed by severe plastic deformation of two ductile metal phases. The extraordinarily high strength of DMMCs is underestimated using the rule of mixture (or volumetric weighted average) of conventionally work-hardened metals. A dislocation-density-based, strain–gradient–plasticity model is proposed to relate the strain-gradient effect with the geometrically necessary dislocations emanating from the interface to better predict the strength of DMMCs. The model prediction was compared with our experimental findings of Cu–Nb, Cu–Ta, and Al–Ti DMMC systems to verify the applicability of the new model. The results show that this model predicts the strength of DMMCs better than the rule-of-mixture model. The strain-gradient effect, responsible for the exceptionally high strength of heavily cold worked DMMCs, is dominant at large deformation strain since its characteristic microstructure length is comparable with the intrinsic material length.

  11. Superconducting open-gradient magnetic separation for the pretreatment of radioactive or mixed waste vitrification feeds. 1997 annual progress report

    SciTech Connect (OSTI)

    Doctor, R.; Nunez, L. [Argonne National Lab., IL (US); Cicero-Herman, C.A. [Westinghouse Savannah River Co., Aiken, SC (US). Savannah River Technology Center; Ritter, J.A. [Univ. of South Carolina, Columbia, SC (US). Chemical Engineering Dept.; Landsberger, S. [Univ. of Texas, Austin, TX (US). Nuclear Engineering Dept.

    1997-01-01

    'Vitrification has been selected as a final waste form technology in the US for long-term storage of high-level radioactive wastes (HLW). However, a foreseeable problem during vitrification in some waste feed streams lies in the presence of elements (e.g., transition metals) in the HLW that may cause instabilities in the final glass product. The formation of spinel compounds, such as Fe{sub 3}O{sub 4} and FeCrO{sub 4}, results in glass phase separation and reduces vitrifier lifetime, and durability of the final waste form. A superconducting open gradient magnetic separation (OGMS) system maybe suitable for the removal of the deleterious transition elements (e.g. Fe, Co, and Ni) and other elements (lanthanides) from vitrification feed streams due to their ferromagnetic or paramagnetic nature. The OGMS systems are designed to deflect and collect paramagnetic minerals as they interact with a magnetic field gradient. This system has the potential to reduce the volume of HLW for vitrification and ensure a stable product. In order to design efficient OGMS and High gradient magnetic separation (HGMS) processes, a fundamental understanding of the physical and chemical properties of the waste feed streams is required. Using HLW simulant and radioactive fly ash and sludge samples from the Savannah River Technology Center, Rocky Flats site, and the Hanford reservation, several techniques were used to characterize and predict the separation capability for a superconducting OGMS system.'

  12. A dislocation-based, strain–gradient–plasticity strengthening model for deformation processed metal–metal composites

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

    Tian, Liang; Russell, Alan; Anderson, Iver

    2014-01-03

    Deformation processed metal–metal composites (DMMCs) are high-strength, high-electrical conductivity composites developed by severe plastic deformation of two ductile metal phases. The extraordinarily high strength of DMMCs is underestimated using the rule of mixture (or volumetric weighted average) of conventionally work-hardened metals. A dislocation-density-based, strain–gradient–plasticity model is proposed to relate the strain-gradient effect with the geometrically necessary dislocations emanating from the interface to better predict the strength of DMMCs. The model prediction was compared with our experimental findings of Cu–Nb, Cu–Ta, and Al–Ti DMMC systems to verify the applicability of the new model. The results show that this model predicts themore »strength of DMMCs better than the rule-of-mixture model. The strain-gradient effect, responsible for the exceptionally high strength of heavily cold worked DMMCs, is dominant at large deformation strain since its characteristic microstructure length is comparable with the intrinsic material length.« less

  13. SU-E-I-41: Non-Cartesian MR Image Reconstruction with Integrated Gradient Non-Linearity Correction

    SciTech Connect (OSTI)

    Tao, S; Trzasko, JD; Polley, TW; Shu, Y; Bernstein, MA [Mayo Clinic, Rochester, MN (United States)

    2014-06-01

    Purpose: Nonlinearities in the spatial encoding gradients of MRI systems cause geometric distortion in images. Typically, this is retrospectively corrected via image-domain interpolation (a.k.a., “gradwarp”) albeit with a loss of spatial resolution. For non-Cartesian MRI, the latter problem is exaggerated by noise and undersampling artifact. In this study, we describe a novel correction strategy that accounts for gradient nonlinearities during — rather than after — non-Cartesian MRI reconstruction, and demonstrate that this approach mitigates the resolution loss that can occur with standard methods. Methods: To test the proposed method, the American College of Radiology (ACR) quality control phantom was scanned on at 1.5 T (General Electric, v16.0, “zoom” gradient) using a 1.6x undersampled 3D non- Cartesian Shells trajectory (GRE, FOV=24 cm3, 120 shells, 16552 shots, 512 readout, matrix=2403). Image reconstruction was first performed via standard k-space density-compensated gridding and retrospectively corrected via cubic spline interpolation. Image reconstruction was then separately performed using a k-space and image-domain densitycompensated type-3 non-uniform fast Fourier transform (NUFFT), which provides a direct mapping between non-Cartesian k-space samples and warped image space voxel locations. Thus, no separate distortion correction procedure is needed for the proposed approach. The gradient distortion field was determined using vendor provided calibration data. Results: Phantom scan results show that both processing approaches successfully correct geometric distortion. However, visual inspection of the ACR phantom spatial resolution inserts shows that the proposed strategy preserves the resolution of the nominal (uncorrected) reconstruction while “gradwarp” imparts marked spatial blurring (especially for the 1.0 and 1.1 mm inserts) and thus resolution loss. Conclusion: We've presented a novel reconstruction strategy for non-Cartesian MRI that corrects for gradient nonlinearities during — rather than after — reconstruction, and thus better preserves image resolution than traditional interpolation-based methods. This approach is expected to be especially advantageous when imaging with non-standard magnet geometries. NIH RR018898; NIH EB10065.

  14. Superconducting Open-Gradient Magnetic Separation for the Pretreatment of Radioactive or Mixed Waste Vitrification Feeds

    SciTech Connect (OSTI)

    Nunez', L.; Kaminsky', M.D.,; Crawford, C.; Ritter, J.A.

    1999-12-31

    An open-gradient magnetic separation (OGMS) process is being considered to separate deleterious elements from radioactive and mixed waste streams prior to vitrification or stabilization. By physically segregating solid wastes and slurries based on the magnetic properties of the solid constituents, this potentially low-cost process may serve the U.S. Department of Energy (DOE) by reducing the large quantities of glass produced from defense-related high-level waste (HLW). Furthermore, the separation of deleterious elements from low-level waste (LLW) also can reduce the total quantity of waste produced in LLW immobilization activities. Many HLW 'and LLW waste' streams at both Hanford and the Savannah River Site (SRS) include constituents deleterious to the durability of borosilicate glass and the melter many of the constituents also possess paramagnetism. For example, Fe, Cr, Ni, and other transition metals may limit the waste loading and affect the durability of the glass by forming spine1 phases at the high operating temperature used in vitrification. Some magnetic spine1 phases observed in glass formation are magnetite (Fe,O,), chromite (FeCrO,), and others [(Fe, Ni, Mg, Zn, Mn)(Al, Fe, Ti, Cr)O,] as described elsewhere [Bates-1994, Wronkiewicz-1994] Stable spine1 phases can cause segregation between the glass and the crystalline phases. As a consequence of the difference in density, the spine1 phases tend to accumulate at the bottom of the glass melter, which decreases the conductivity and melter lifetime [Sproull-1993]. Crystallization also can affect glass durability [Jantzen-1985, Turcotte- 1979, Buechele-1990] by changing the chemical composition of the matrix glass surrounding the crystals or causing stress at the glass/crystal interface. These are some of the effects that can increase leaching [Jantzen-1985]. A SRS glass that was partially crystallized to contain 10% vol. crystals composed of spinels, nepheline, and acmite phases showed minimal changes in short term leachability [Jantzen-1985, Hench-1982]. However, Jantzen et k > al. found that leaching increased preferentially at grain boundary interfaces [Jantzen-1985]. For a SRL 165 glass crystallized up to 30% vol., leachability measured by normalized boron release increased by a factor of three compared to the uncrystallized glass [Kelly-1975, Plodinec-1979]. In general, the magnitude of the crystallization effect depends highly on glass composition and cooling rate.

  15. Digital Manufacturing of Gradient Meshed SOFC Sealing Composites with Self-Healing Capabilities

    SciTech Connect (OSTI)

    Kathy Lu; Christopher Story; W.T. Reynolds

    2007-12-21

    Solid oxide fuel cells (SOFC) hold great promise for clean power generation. However, high temperature stability and long term durability of the SOFC components have presented serious problems in SOFC technological advancement and commercialization. The seals of the fuel cells are the most challenging area to address. A high temperature gas seal is highly needed which is durable against cracking and gas leakage during thermal cycling and extended operation. This project investigates a novel composite seal by integrating 3D printed shape memory alloy (SMA) wires into a glass matrix. The SMA we use is TiNiHf and the glass matrix we use is SrO-La{sub 2}O{sub 3}-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3}-SiO{sub 2} (SLABS). Dilatometry shows to be an extremely useful tool in providing the CTEs. It pinpoints regions of different CTEs under simulated SOFC thermal cycles for the same glass. For the studied SLABS glass system, the region with the greatest CTE mismatch between the glass seal and the adjacent components is 40-500 C, the typical heating and cooling regions for SOFCs. Even for low temperature SOFC development, this region is still present and needs to be addressed. We have demonstrated that the proposed SLABS glass has great potential in mitigating the thermal expansion mismatch issues that are limiting the operation life of SOFCs. TiNiHf alloy has been successfully synthesized with the desired particle size for the 3DP process. The TiNiHf SMA shape memory effect very desirably overlaps with the problematic low CTE region of the glass. This supports the design intent that the gradient structure transition, phase transformation toughening, and self-healing of the SMA can be utilized to mitigate/eliminate the seal problem. For the 3DP process, a new binder has been identified to match with the specific chemistry of the SMA particles. This enables us to directly print SMA particles. Neutron diffraction shows to be an extremely useful tool in providing information regarding the austenite to martensite phase transformation, SMA alloy lattice constant change, and the corresponding thermal stress from the glass matrix. It pinpoints regions of SMA phase transformation and the thermal stress effect under simulated SOFC thermal cycles. The bilayer test shows that there is still much work to be done for the proper integration of the seal components. Large scale production should lower the cost associated with the proposed approach, especially on the raw material cost and 3D printing.

  16. Covariation of climate and long-term erosion rates across a steep rainfall gradient on the Hawaiian island of Kaua'i

    E-Print Network [OSTI]

    Ferrier, Ken L.

    Erosion of volcanic ocean islands creates dramatic landscapes, modulates Earth’s carbon cycle, and delivers sediment to coasts and reefs. Because many volcanic islands have large climate gradients and minimal variations ...

  17. GEOC R Lee Penn Sunday, March 25, 2012 12 -Biogeochemical transformation of Fe-and Mn-along a redox gradient: Implications for carbon sequestration

    E-Print Network [OSTI]

    Sparks, Donald L.

    a redox gradient: Implications for carbon sequestration within the Christina River Basin Critical Zone States Organic carbon (C)-mineral complexation mechanism is crucial in C sequestration. It is a function

  18. Charge Hall effect driven by spin-dependent chemical potential gradients and Onsager relations in mesoscopic systems RID B-8398-2011 RID A-7392-2009 

    E-Print Network [OSTI]

    Hankiewicz, EM; Li, J.; Jungwirth, T.; Niu, Q.; Shen, SQ; Sinova, Jairo.

    2005-01-01

    We study theoretically the spin-Hall effect as well as its reciprocal phenomenon (a transverse charge current driven by a spin-dependent chemical potential gradient) in electron and hole finite size mesoscopic systems. The Landauer...

  19. Long-Gradient Separations Coupled with Selected Reaction Monitoring for Highly Sensitive, Large Scale Targeted Protein Quantification in a Single Analysis

    SciTech Connect (OSTI)

    Shi, Tujin; Fillmore, Thomas L.; Gao, Yuqian; Zhao, Rui; He, Jintang; Schepmoes, Athena A.; Nicora, Carrie D.; Wu, Chaochao; Chambers, Justin L.; Moore, Ronald J.; Kagan, Jacob; Srivastava, Sudhir; Liu, Alvin Y.; Rodland, Karin D.; Liu, Tao; Camp, David G.; Smith, Richard D.; Qian, Weijun

    2013-10-01

    Long-gradient separations coupled to tandem MS were recently demonstrated to provide a deep proteome coverage for global proteomics; however, such long-gradient separations have not been explored for targeted proteomics. Herein, we investigate the potential performance of the long-gradient separations coupled with selected reaction monitoring (LG-SRM) for targeted protein quantification. Direct comparison of LG-SRM (5 h gradient) and conventional LC-SRM (45 min gradient) showed that the long-gradient separations significantly reduced background interference levels and provided an 8- to 100-fold improvement in LOQ for target proteins in human female serum. Based on at least one surrogate peptide per protein, an LOQ of 10 ng/mL was achieved for the two spiked proteins in non-depleted human serum. The LG-SRM detection of seven out of eight endogenous plasma proteins expressed at ng/mL or sub-ng/mL levels in clinical patient sera was also demonstrated. A correlation coefficient of >0.99 was observed for the results of LG-SRM and ELISA measurements for prostate-specific antigen (PSA) in selected patient sera. Further enhancement of LG-SRM sensitivity was achieved by applying front-end IgY14 immunoaffinity depletion. Besides improved sensitivity, LG-SRM offers at least 3 times higher multiplexing capacity than conventional LC-SRM due to ~3-fold increase in average peak widths for a 300-min gradient compared to a 45-min gradient. Therefore, LG-SRM holds great potential for bridging the gap between global and targeted proteomics due to its advantages in both sensitivity and multiplexing capacity.

  20. Bel-Robinson as stress-tensor gradients and their extensions to massive spin (0,1,2)

    E-Print Network [OSTI]

    S. Deser; J. Franklin

    2015-03-12

    We show that the Bel-Robinson (BR) tensor is - generically, as well as in its original GR setting - an autonomously conserved part of the, manifestly conserved, double gradient of a system's stress-tensor. This suggests its natural extension from GR to matter models, first to (known) massless scalars and vectors, then to massive ones, including tensors. These massive versions are to be expected, given that they arise upon KK reduction of massless D+1 ones. We exhibit the resulting spin (0, 1, 2) "massive" BR.

  1. Microfluidic device having an immobilized pH gradient and PAGE gels for protein separation and analysis

    DOE Patents [OSTI]

    Sommer, Gregory J.; Hatch, Anson V.; Singh, Anup K.; Wang, Ying-Chih

    2012-12-11

    Disclosed is a novel microfluidic device enabling on-chip implementation of a two-dimensional separation methodology. Previously disclosed microscale immobilized pH gradients (IPG) are combined with perpendicular polyacrylamide gel electrophoresis (PAGE) microchannels to achieve orthogonal separations of biological samples. Device modifications enable inclusion of sodium dodecyl sulfate (SDS) in the second dimension. The device can be fabricated to use either continuous IPG gels, or the microscale isoelectric fractionation membranes we have also previously disclosed, for the first dimension. The invention represents the first all-gel two-dimensional separation microdevice, with significantly higher resolution power over existing devices.

  2. A comparison of conjugate gradient, SIP, and other iterative methods for the solution of Poisson's equation with irregular boundary conditions

    SciTech Connect (OSTI)

    Bergmann, D.J.

    1990-06-01

    Several well known iterative methods for solving Poisson's equation, including Strongly Implicit Procedure and several preconditioned conjugate gradient methods are first applied to a problem with simple boundary conditions and a known solution. Then a problem with more complicated boundary conditions, similar to those encountered when modeling AVLIS plasmas, is solved. Differences in the solutions of the various methods are examined through the use of Fourier analysis. It was found that combinations of different iterative schemes will in some cases be the most efficient method of solution. 22 refs., 29 figs.

  3. Effect of electron-density gradients on propagation of radio waves in the mid-latitude trough. Master's thesis

    SciTech Connect (OSTI)

    Citrone, P.J.

    1991-01-01

    Partial contents of this thesis include: (1) Radio-wave propagation and the mid-latitude trough; (2) Ionospheric measurements; (3) Modification of time-dependent ionospheric model output with latitudinal electron-density profiles from digisonde trough depictions; (4) Ray-tracing simulations to examine ground range; and (5) Effects of three-dimensional gradients in electron density on radio-wave propagation in the trough region. Data is tabulated for geophysical conditions, solar activity level, geomagnetic activity level, conditions for vertical ray refraction to surface, and ray-tracing fixed-input conditions.

  4. Lattice gradient flow with tree-level $\\mathcal{O}(a^4)$ improvement in pure Yang-Mills theory

    E-Print Network [OSTI]

    Norihiko Kamata; Shoichi Sasaki

    2015-11-19

    Following a recent paper by Fodor et al. (arXiv:1406.0827), we reexamine several types of tree-level improvements on the flow action with various gauge actions in order to reduce the lattice discretization errors in the Yang-Mills gradient flow method. We propose two types of tree-level, $\\mathcal{O}(a^4)$ improved lattice gradient flow including the rectangle term in both the flow and gauge action within the minimal way. We then perform numerical simulations with the simple plaquette gauge action for testing our proposal. Our numerical results of the expectation value of the action density, $\\langle E(t)\\rangle$, show that two $\\mathcal{O}(a^4)$ improved flows significantly eliminate the discretization corrections in the small flow time $t$ regime. On the other hand, the values of $t^2\\langle E(t)\\rangle$ in the large $t$ regime, where the lattice spacing dependence of the tree-level term dies out as inverse powers of $t/a^2$, are different between the results given by two optimal flows leading to the same $\\mathcal{O}(a^4)$ improvement at tree level. This may suggest that non-negligible $\\mathcal{O}(g^2 a^2)$ effect sets in the large $t$ regime, where the running coupling $g(1/\\sqrt{8t})$ becomes large.

  5. Chemical evolution of the inner 2 degrees of the Milky Way bulge: [alpha/Fe] trends and metallicity gradients

    E-Print Network [OSTI]

    Ryde, N; Grieco, V; Matteucci, F; Rich, R M; Uttenthaler, S

    2015-01-01

    The structure, formation, and evolution of the Milky Way bulge is a matter of debate. Important diagnostics for discriminating between bulge models include alpha-abundance trends with metallicity, and spatial abundance and metallicity gradients. Due to the severe optical extinction in the inner Bulge region, only a few detailed investigations have been performed of this region. Here we aim at investigating the inner 2 degrees by observing the [alpha/Fe] element trends versus metallicity, and by trying to derive the metallicity gradient. [alpha/Fe] and metallicities have been determined by spectral synthesis of 2 micron spectra observed with VLT/CRIRES of 28 M-giants, lying along the Southern minor axis at (l,b)=(0,0), (0,-1), and (0,-2). VLT/ISAAC spectra are used to determine the effective temperature of the stars. We present the first connection between the Galactic Center and the Bulge using similar stars, high spectral resolution, and analysis techniques. The [alpha/Fe] trends in all our 3 fields show a l...

  6. Coupling of ion temperature gradient and trapped electron modes in the presence of impurities in tokamak plasmas

    SciTech Connect (OSTI)

    Du, Huarong; Wang, Zheng-Xiong, E-mail: zxwang@dlut.edu.cn [MOE Key Laboratory of Materials Modification by Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [MOE Key Laboratory of Materials Modification by Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Dong, J. Q. [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China) [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China); Southwestern Institute of Physics, Chengdu 610041 (China); Liu, S. F. [School of Physics, Nankai University, Tianjin 300071 (China)] [School of Physics, Nankai University, Tianjin 300071 (China)

    2014-05-15

    The coupling of ion temperature gradient (ITG or ?{sub i}) mode and trapped electron mode (TEM) in the presence of impurity ions is numerically investigated in toroidal collisionless plasmas, using the gyrokinetic integral eigenmode equation. A framework for excitations of the ITG modes and TEMs with respect to their driving sources is formulated first, and then the roles of impurity ions played in are analyzed comprehensively. In particular, the characteristics of the ITG and TEM instabilities in the presence of impurity ions are emphasized for both strong and weak coupling (hybrid and coexistent) cases. It is found that the impurity ions with inwardly (outwardly) peaked density profiles have stabilizing (destabilizing) effects on the hybrid (namely the TE-ITG) modes in consistence with previous works. A new finding of this work is that the impurity ions have stabilizing effects on TEMs in small ?{sub i} (?{sub i}?1) regime regardless of peaking directions of their density profiles whereas the impurity ions with density gradient L{sub ez}=L{sub ne}/L{sub nz}>1 (L{sub ez}<1) destabilize (stabilize) the TEMs in large ?{sub i} (?{sub i}?1) regime. In addition, the dependences of the growth rate, real frequency, eigenmode structure, and wave spectrum on charge concentration, charge number, and mass of impurity ions are analyzed in detail. The necessity for taking impurity ion effects on the features of turbulence into account in future transport experimental data analyses is also discussed.

  7. The development of a high-throughput gradient array apparatus for the study of porous polymer networks.

    SciTech Connect (OSTI)

    Majumdar, Partha; Lee, Elizabeth; Chisholm, Bret J.; Dirk, Shawn M.; Weisz, Michael; Bahr, James; Schiele, Kris

    2010-01-01

    A gradient array apparatus was constructed for the study of porous polymers produced using the process of chemically-induced phase separation (CIPS). The apparatus consisted of a 60 element, two-dimensional array in which a temperature gradient was placed in the y-direction and composition was varied in the x-direction. The apparatus allowed for changes in opacity of blends to be monitored as a function of temperature and cure time by taking images of the array with time. The apparatus was validated by dispense a single blend composition into all 60 wells of the array and curing them for 24 hours and doing the experiment in triplicate. Variations in micron scale phase separation were readily observed as a function of both curing time and temperature and there was very good well-to-well consistency as well as trial-to-trial consistency. Poragen of samples varying with respect to cure temperature was removed and SEM images were obtained. The results obtained showed that cure temperature had a dramatic affect on sample morphology, and combining data obtained from visual observations made during the curing process with SEM data can enable a much better understanding of the CIPS process and provide predictive capability through the relatively facile generation of composition-process-morphology relationships. Data quality could be greatly enhanced by making further improvements in the apparatus. The primary improvements contemplated include the use of a more uniform light source, an optical table, and a CCD camera with data analysis software. These improvements would enable quantification of the amount of scattered light generated from individual elements as a function of cure time. In addition to the gradient array development, porous composites were produced by incorporating metal particles into a blend of poragen, epoxy resin, and crosslinker. The variables involved in the experiment were metal particle composition, primary metal particle size, metal concentration, and poragen composition. A total of 16 different porous composites were produced and characterized using SEM. In general, the results showed that pore morphology and the distribution of metal particles was dependent on multiple factors. For example, the use of silver nanoparticles did not significantly affect pore morphology for composites derived from decanol as the poragen, but exceptionally large pores were obtained with the use of decane as the poragen. With regard to the effect of metal particle size, silver nanoparticles were essentially exclusively dispered in the polymer matrix while silver microparticles were found in pores. For nickel particles, both nanoparticles and microparticles were largely dispersed in the polymer matrix and not in the pores.

  8. Method and apparatus for producing a carbon based foam article having a desired thermal-conductivity gradient

    DOE Patents [OSTI]

    Klett, James W. (Knoxville, TN) [Knoxville, TN; Cameron, Christopher Stan (Sanford, NC) [Sanford, NC

    2010-03-02

    A carbon based foam article is made by heating the surface of a carbon foam block to a temperature above its graphitizing temperature, which is the temperature sufficient to graphitize the carbon foam. In one embodiment, the surface is heated with infrared pulses until heat is transferred from the surface into the core of the foam article such that the graphitizing temperature penetrates into the core to a desired depth below the surface. The graphitizing temperature is maintained for a time sufficient to substantially entirely graphitize the portion of the foam article from the surface to the desired depth below the surface. Thus, the foam article is an integral monolithic material that has a desired conductivity gradient with a relatively high thermal conductivity in the portion of the core that was graphitized and a relatively low thermal conductivity in the remaining portion of the foam article.

  9. Contribution to the Study of Ferrite Nanobeads: Synthesis, Characterization and Investigation of Horizontal Low Gradient Magnetophoresis Behaviour

    SciTech Connect (OSTI)

    Benelmekki, Maria; Caparros, Cristina; Goncalves, Renao; Lanceros-Mendez, Senenxu; Montras, Anna; Martinez, Lluis Miquel

    2010-12-02

    In this work we investigate the possibilities of the use of Horizontal Low Gradient Magnetic Field (HLGMF)(<100 T/m) for filtration, control and separation of the synthesized magnetic particles, considering, the characteristics of the suspension, the size and the type of nanoparticles (NPs) and focusing on the process scale up. Reversible aggregation is considered in the different steps of magnetic nanobeads synthesis. For these purpose, we synthesized Fe{sub 2}O{sub 3}-silica core-shell nanobeads by co-precipitation, monodispersion and silica coating. SQUID, TEM, XRD, and Zeta potential techniques were used to characterize the synthesized nanobeads. An extensive magnetophoresis study was performed at different magnetophoretic conditions. Different reversible aggregation times were observed at different HLGMF, at each step of the synthesis route: Several orders of magnitude differences where observed when comparing citric acid (CA) suspension with silicon coated beads. Reversible aggregation times are correlated with the properties of the NPs at different steps of synthesis.

  10. Structural Evolution and Li Dynamics in Nanophase Li3PS4 by Solid-State and Pulsed Field Gradient NMR

    SciTech Connect (OSTI)

    Gobet, Mallory [Hunter College of the City University of New York] [Hunter College of the City University of New York; Greenbaum, Steve [Hunter College of the City University of New York] [Hunter College of the City University of New York; Sahu, Gayatri [ORNL] [ORNL; Liang, Chengdu [ORNL] [ORNL

    2014-01-01

    The ceramic lithium ion conductor -Li3PS4 has a disordered and nanoporous structure that leads to an enhancement in ionic conductivity by some three orders of magnitude compared to the crystalline phase. The phase is prepared by thermal treatment of an inorganic-organic complex based on Li3PS4 and THF. Multinuclear (1H, 6,7Li, 31P) solid state NMR spectroscopy is used to characterize the structural phase evolution of the starting material at various steps in the thermal treatment. The phase formed after high temperature treatment is recognized as spectroscopically distinct from the bulk -Li3PS4 compound. Also formed is an amorphous lithium thiophosphate phase that is metastable as verified by annealing over an extended period. Lithium ion self-diffusion coefficients are measurable by standard pulsed gradient NMR methods at 100oC and with values consistent with the high ionic conductivity previously reported for this material.

  11. A New Green's Function for the Wake Potential Calculation of the SLAC S-band Constant Gradient Accelerating Section

    SciTech Connect (OSTI)

    Novokhatski, A,; /SLAC

    2012-02-17

    The behavior of the longitudinal wake fields excited by a very short bunch in the SLAC S-band constant gradient accelerating structures has been studied. Wake potential calculations were performed for a bunch length of 10 microns using the author's code to obtain a numerical solution of Maxwell's equations in the time domain. We have calculated six accelerating sections in the series (60-ft) to find the stationary solution. While analyzing the computational results we have found a new formula for the Green's function. Wake potentials, which are calculated using this Green's function are in amazingly good agreement with numerical results over a wide range of bunch lengths. The Green's function simplifies the wake potential calculations and can be easily incorporated into the tracking codes. This is very useful for beam dynamics studies of the linear accelerators of LCLS and FACET.

  12. Momentum transport in the vicinity of q{sub min} in reverse shear tokamaks due to ion temperature gradient turbulence

    SciTech Connect (OSTI)

    Singh, Rameswar; Laboratoire de Physique des Plasmas, Ecole Polytechnique route de Saclay, 91128 Palaiseau Cedex ; Singh, R; WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 ; Jhang, Hogun; Diamond, P. H.; Center for Momentum Transport and Flow Organization, University of California, San Diego, California 92093; Center for Astrophysics and Space Sciences, University of California San Diego, 9500 Gilman Dr., La Jolla, California 92093-0424

    2014-01-15

    We present an analytic study of momentum transport of tokamak plasmas in the vicinity of minimum safety factor (q) position in reversed magnetic shear configuration. Slab ion temperature gradient modes with an equilibrium flow profile are considered in this study. Quasi-linear calculations of momentum flux clearly show the novel effects of q-curvature on the generation of intrinsic rotation and mean poloidal flow without invoking reflectional symmetry breaking of parallel wavenumber (k{sub ?}). This q-curvature effect originates from the inherent asymmetry in k{sub ?} populations with respect to a rational surface due to the quadratic proportionality of k{sub ?} when q-curvature is taken into account. Discussions are made of possible implications of q-curvature induced plasma flows on internal transport barrier formation in reversed shear tokamaks.

  13. Large-scale spatial variability of riverbed temperature gradients in Snake River fall Chinook salmon spawning areas

    SciTech Connect (OSTI)

    Hanrahan, Timothy P.

    2007-02-01

    In the Snake River basin of the Pacific northwestern United States, hydroelectric dam operations are often based on the predicted emergence timing of salmon fry from the riverbed. The spatial variability and complexity of surface water and riverbed temperature gradients results in emergence timing predictions that are likely to have large errors. The objectives of this study were to quantify the thermal heterogeneity between the river and riverbed in fall Chinook salmon spawning areas and to determine the effects of thermal heterogeneity on fall Chinook salmon emergence timing. This study quantified river and riverbed temperatures at 15 fall Chinook salmon spawning sites distributed in two reaches throughout 160 km of the Snake River in Hells Canyon, Idaho, USA, during three different water years. Temperatures were measured during the fall Chinook salmon incubation period with self-contained data loggers placed in the river and at three different depths below the riverbed surface. At all sites temperature increased with depth into the riverbed, including significant differences (p<0.05) in mean water temperature of up to 3.8°C between the river and the riverbed among all the sites. During each of the three water years studied, river and riverbed temperatures varied significantly among all the study sites, among the study sites within each reach, and between sites located in the two reaches. Considerable variability in riverbed temperatures among the sites resulted in fall Chinook salmon emergence timing estimates that varied by as much as 55 days, depending on the source of temperature data used for the estimate. Monitoring of riverbed temperature gradients at a range of spatial scales throughout the Snake River would provide better information for managing hydroelectric dam operations, and would aid in the design and interpretation of future empirical research into the ecological significance of physical riverine processes.

  14. The POTS cascade transient code and the calculation of the times required to get production U-235 gradients at Oak Ridge and Paducah

    SciTech Connect (OSTI)

    Kelleher, D.M. Jr.; Ebel, R.A.

    1988-03-01

    This report describes the POTS Gaseous Diffusion Transient Analysis Code and how it was used to calculate the times that would be required to get production uranium-235 (U-235) gradients in the cascades at the Oak Ridge and Paducah Gaseous Diffusion Plants if the cascades were restarted after an extended shutdown. Version 3.0 of the POTS code, the method used to calculate the times, and plots showing how the U-235 gradients would change after the cascades were restarted are presented.

  15. Calibrating the BOLD signal revisited Calculation of oxygen metabolism for gradient-and spin-echo sequence up to 16.4T , A-C. Zappe1

    E-Print Network [OSTI]

    Calibrating the BOLD signal revisited ­ Calculation of oxygen metabolism for gradient- and spin to the the signal. One goal of quantitative fMRI is to determine oxygen metabolism (CMRO2) from fMRI data. To this end, a calibrated BOLD approach has been proposed calculating oxygen metabolism from combined CBF

  16. Statistical mechanical theory for the structure of steady state systems: Application to a Lennard-Jones fluid with applied temperature gradient

    E-Print Network [OSTI]

    Attard, Phil

    Statistical mechanical theory for the structure of steady state systems: Application to a Lennard-Jones fluid with applied temperature gradient Phil Attard School of Chemistry F11, University of Sydney, New statistical mechanics for inhomogeneous systems may now be applied to determining the structure

  17. 3D joint inversion of gradient and total-field magnetic data Kristofer Davis and Yaoguo Li, Center for Gravity, Electrical, and Magnetics, Colorado School of Mines, Golden,

    E-Print Network [OSTI]

    for Gravity, Electrical, and Magnetics, Colorado School of Mines, Golden, Colorado SUMMARY Recently3D joint inversion of gradient and total-field magnetic data Kristofer Davis and Yaoguo Li, Center and demonstrate it with a synthetic and field example. INTRODUCTION Airborne magnetic gradiometry data

  18. Concentrating colloids with electric field gradients. I. Particle transport and growth mechanism of hard-sphere-like crystals in an electric bottle

    E-Print Network [OSTI]

    Leunissen, Mirjam

    Concentrating colloids with electric field gradients. I. Particle transport and growth mechanism of hard-sphere-like crystals in an electric bottle Mirjam E. Leunissen,1,a ,b Matthew T. Sullivan,2,3,c. Inside a specially designed "electric bottle," we observed our colloids to collect in the regions

  19. K. Pham et alii, Frattura ed Integrit Strutturale, 19 (2012) 5-19; DOI: 10.3221/IGF-ESIS.19.01 Damage localization and rupture with gradient damage models

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    2012-01-01

    Damage localization and rupture with gradient damage models K. Pham Université Pierre et Marie Curie of an elastic-damaging material whose softening behavior is regularized by a gradient damage model. We show that at the center of the localization zone when the damage reaches there the critical value corresponding

  20. Electric field and ionization-gradient effects on inertial-confinement-fusion implosions This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Electric field and ionization-gradient effects on inertial-confinement-fusion implosions.1088/0741-3335/51/12/124048 Electric field and ionization-gradient effects on inertial-confinement-fusion implosions P A Amendt1 , J L-generated electric fields (108 ­109 V m-1 ) in direct-drive, inertial-confinement-fusion capsules has been reported