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1

Hot Pot Contoured Temperature Gradient Map  

SciTech Connect (OSTI)

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

Lane, Michael

2013-06-28T23:59:59.000Z

2

Hot Pot Contoured Temperature Gradient Map  

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

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

Lane, Michael

3

Results of temperature gradient and heat flow in Santiam Pass Area, Oregon, Volume 1  

SciTech Connect (OSTI)

The conclusions of this report are: (1) There is a weakly defined thermal anomaly within the area examined by temperature-gradient holes in the Santiam Pass area. This is a relict anomaly showing differences in permeability between the High Cascades and Western Cascades areas, more than a fundamental difference in shallow crustal temperatures. (2) The anomaly as defined by the 60 F isotherms at 400 feet follows a north-south trend immediately westward of the Cascade axis in the boundary region. It is clear that all holes spudded into High Cascades rocks result in isothermal and reversal gradients. Holes spudded in Western Cascades rocks result in positive gradients. (3) Cold groundwater flow influences and masks temperature gradients in the High Cascades to a depth of at least 700 feet, especially eastward from the major north-south trending faults. Pleistocene and Holocene rocks are very permeable aquifers. (4) Shallow gradient drilling in the lowlands westward of the faults provides more interpretable information than shallow drilling in the cold-water recharge zones. Topographic and climatological effects can be filtered out of the temperature gradient results. (5) The thermal anomaly seems to have 2 centers: one in the Belknap-Foley area, and one northward in the Sand Mountain area. The anomalies may or may not be connected along a north-south trend. (6) A geothermal effect is seen in holes downslope of the Western-High Cascade boundary. Mixing with cold waters is a powerful influence on temperature gradient data. (7) The temperature-gradient program has not yet examined and defined the geothermal resources potential of the area eastward of the Western Cascades-High Cascades boundary. Holes to 1500-2000 feet in depth are required to penetrate the high permeability-cold groundwater regime. (8) Drilling conditions are unfavorable. There are very few accessible level drill sites. Seasonal access problems and environmental restrictions together with frequent lost circulation results in very high costs per foot drilled.

Cox, B.L.; Gardner, M.C.; Koenig, J.B.

1981-08-01T23:59:59.000Z

4

Ballistic dispersion in temperature gradient focusing  

E-Print Network [OSTI]

regime is the most familiar regime in microfluidic systems, an oft-overlooked regime is that of purely kinematic (or ballistic) dispersion. In most microfluidic systems, this dispersion regime is transient systems. Keywords: microfluidics; temperature gradient focusing; kinematic dispersion; Taylor

Santiago, Juan G.

5

Short wavelength ion temperature gradient turbulence  

SciTech Connect (OSTI)

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.

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)

2012-10-15T23:59:59.000Z

6

Measurements of aerosol thermophoretic deposition: Transition with temperature gradient  

SciTech Connect (OSTI)

Thermophoresis is the motion of aerosol particles due to a temperature gradient in the suspending gas. The thermophoretic velocity V{sub T} is expressed as: where a {alpha} = thermal diffusivity v = kinematic viscosity H= Pr K Pr = Prandtl number K = dimensionless coefficient that is a function of several parameters (particle radius, thermal conductivity, gas properties, gas surface interactions). This report describes measurements of the effects of temperature gradients on the deposition of polystyrene latex particles.

Varma, A.; Tompson, R.V.; Loyalka, S.K. [Univ. of Missouri, Columbia, MO (United States)

1995-12-31T23:59:59.000Z

7

North-South Forum Education for Sustainable Development  

E-Print Network [OSTI]

North-South Forum Education for Sustainable Development The Perspective of Swiss Universities Prof. Dr. Doris Wastl-Walter Universität Bern #12;14. November 2012 Education for Sustainable Development Koordination im schweizerischen Hochschulbereich (HFKG)). > Sustainable Development (SD) as a requirement

Richner, Heinz

8

Manipulation of Colloids by Nonequilibrium Depletion Force in Temperature Gradient  

E-Print Network [OSTI]

The non-equilibrium distribution of colloids in a polymer solution under a temperature gradient is studied experimentally. A slight increase of local temperature by a focused laser drives the colloids towards the hot region, resulting in the trapping of the colloids irrespective of their own thermophoretic properties. An amplification of the trapped colloid density with the polymer concentration is measured, and is quantitatively explained by hydrodynamic theory. The origin of the attraction is a migration of colloids driven by a non-uniform polymer distribution sustained by the polymer's thermophoresis. These results show how to control thermophoretic properties of colloids.

Hong-Ren Jiang; Hirofumi Wada; Natsuhiko Yoshinaga; Masaki Sano

2009-04-22T23:59:59.000Z

9

Formation of Complex Structures in Dusty Plasmas under Temperature Gradients  

SciTech Connect (OSTI)

Thermophoretic effects on dust structures under temperature gradients in glow and radio-frequency discharge plasmas are studied experimentally. The geometry of dust structures consisting of micrometer-sized polydisperse grains depends on heat release in the plasma. Thermophoretic forces associated with heat release can control the formation of dust structures of different geometries. A theoretical model is proposed to describe dust separation with respect to grain size caused by the effects of radial electrostatic and thermophoretic forces. The glow discharge currents under critical conditions for grain separation predicted by the model agree with those observed experimentally.

Vasilyak, L.M.; Vetchinin, S.P.; Polyakov, D.N.; Fortov, V.E. [Institute for High Energy Densities, Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow, 125412 (Russian Federation)

2005-05-01T23:59:59.000Z

10

Electron geodesic acoustic modes in electron temperature gradient mode turbulence  

SciTech Connect (OSTI)

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.

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)

2012-08-15T23:59:59.000Z

11

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

SciTech Connect (OSTI)

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.

Holcomb, G.R.

2008-04-01T23:59:59.000Z

12

Three Easy Ways to Order Call: 18007774643 (within North & South America)  

E-Print Network [OSTI]

ORDER FORM Three Easy Ways to Order Call: 1­800­777­4643 (within North & South America) (212) 460­1500 (outside North & South America) Fax: (201) 348­4505 Mail: Birkhäuser, PO Box 2485 Secaucus, NJ 07096 book (within North and South America); $10.00 for the first & $5.00 for each additional book (outside

Sørensen, Michael

13

Coherent structures in ion temperature gradient turbulence-zonal flow  

SciTech Connect (OSTI)

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.

Singh, Rameswar, E-mail: rameswar.singh@lpp.polytechnique.fr [Laboratoire de Physique des Plasmas, Ecole Polytechnique, Route de Saclay, 91128 Palaiseau Cedex (France); Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India); Singh, R. [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India); WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Kaw, P. [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India); Gürcan, Ö. D. [Laboratoire de Physique des Plasmas, Ecole Polytechnique, Route de Saclay, 91128 Palaiseau Cedex (France); Diamond, P. H. [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); CMTFO and CASS, University of California, San Diego, California 92093 (United States)

2014-10-15T23:59:59.000Z

14

Ion temperature gradient driven turbulence with strong trapped ion resonance  

SciTech Connect (OSTI)

A theory to describe basic characterization of ion temperature gradient driven turbulence with strong trapped ion resonance is presented. The role of trapped ion granulations, clusters of trapped ions correlated by precession resonance, is the focus. Microscopically, the presence of trapped ion granulations leads to a sharp (logarithmic) divergence of two point phase space density correlation at small scales. Macroscopically, trapped ion granulations excite potential fluctuations that do not satisfy dispersion relation and so broaden frequency spectrum. The line width from emission due only to trapped ion granulations is calculated. The result shows that the line width depends on ion free energy and electron dissipation, which implies that non-adiabatic electrons are essential to recover non-trivial dynamics of trapped ion granulations. Relevant testable predictions are summarized.

Kosuga, Y., E-mail: kosuga@riam.kyushu-u.ac.jp [Institute for Advanced Study, Kyushu University, Fukuoka (Japan); Research Institute for Applied Mechanics, Kyushu University, Fukuoka (Japan); Itoh, S.-I. [Research Center for Plasma Turbulence, Kyushu University, Fukuoka (Japan); Research Institute for Applied Mechanics, Kyushu University, Fukuoka (Japan); Diamond, P. H. [CASS and CMTFO, University of California at San Diego, La Jolla, California 92093 (United States); WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon (Korea, Republic of); Itoh, K. [National Institute for Fusion Science, Gifu (Japan); Research Center for Plasma Turbulence, Kyushu University, Fukuoka (Japan); Lesur, M. [Research Institute for Applied Mechanics, Kyushu University, Fukuoka (Japan)

2014-10-15T23:59:59.000Z

15

Geology and Temperature Gradient Surveys Blue Mountain Geothermal...  

Open Energy Info (EERE)

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

16

Supercurrent-Induced Temperature Gradient across a Nonequilibrium SNS Josephson Junction M. S. Crosser,1  

E-Print Network [OSTI]

Supercurrent-Induced Temperature Gradient across a Nonequilibrium SNS Josephson Junction M. S direction. The feature represents an effective temperature gradient across the SNS Josephson junction Josephson junction (SNS JJ) into a `` junction'' by driving the electron energy distribution far from

Birge, Norman

17

On the maintenance of weak meridional temperature gradients during warm climates  

E-Print Network [OSTI]

This thesis examines the dynamics of equable climates. The underlying physics of two mechanisms by which weak meridional temperature gradients might be maintained are studied. First, I examine the evolution of stratospheric ...

Korty, Robert Lindsay

2005-01-01T23:59:59.000Z

18

Mirror symmetry breaking with limited enantioselective autocatalysis and temperature gradients: a stability survey  

E-Print Network [OSTI]

We analyze limited enantioselective (LES) autocatalysis in a temperature gradient and with internal flow/recycling of hot and cold material. Microreversibility forbids broken mirror symmetry for LES in the presence of a temperature gradient alone. This symmetry can be broken however when the auto-catalysis and limited enantioselective catalysis are each localized within the regions of low and high temperature, respectively. This scheme has been recently proposed as a plausible model for spontaneous emergence of chirality in abyssal hydrothermal vents. Regions in chemical parameter space are mapped out in which the racemic state is unstable and bifurcates to chiral solutions.

Blanco, Celia; Crusats, Joaquim; El-Hachemi, Zoubir; Moyano, Albert; Hochberg, David; 10.1039/C2CP43488A

2012-01-01T23:59:59.000Z

19

Probing plasma turbulence by modulating the electron temperature gradient  

E-Print Network [OSTI]

The local value of a/L[subscript Te], a turbulence drive term, was modulated with electron cyclotron heating in L-mode discharges on DIII-D [ J. L. Luxon, Nucl. Fusion 42, 614 (2002) ] and the density and electron temperature ...

DeBoo, J. C.

20

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

SciTech Connect (OSTI)

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.

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)

2014-03-15T23:59:59.000Z

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


21

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

E-Print Network [OSTI]

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

Royer, Dana

22

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

E-Print Network [OSTI]

Water transport inside a single-walled carbon nanotube driven by temperature gradient J. Shiomi mass transport of a water cluster inside a single-walled carbon nanotube (SWNT) with the diameter of about 1.4 nm. The influence of the non-equilibrium thermal environment on the confined water cluster has

Maruyama, Shigeo

23

Electron velocity distribution function in a plasma with temperature gradient and in the presence of suprathermal  

E-Print Network [OSTI]

Electron velocity distribution function in a plasma with temperature gradient and in the presence of suprathermal electrons: application to incoherent-scatter plasma lines P. Guio1 , J. Lilensten2 , W. Kofman2 arbitrary velocity distribution function with cylindrical symmetry along the magnetic ®eld. The electron

Paris-Sud XI, Université de

24

Effect of Temperature Gradient on Industrial Coal Slag Infiltration into Porous Refractory Materials in Slagging Gasifiers  

SciTech Connect (OSTI)

Infiltration characteristics of industrial coal slag into alumina (Al{sub 2}O{sub 3}) refractory material with a temperature gradient induced along the slag's penetration direction are compared to those obtained under near-isothermal conditions. Experiments were conducted with a hot-face temperature of 1450°C and a CO/CO{sub 2} ratio of 1.8, which corresponds to an oxygen partial pressure of ~10{sup ?8} atm. The refractory under the near-isothermal temperature profile, with higher average temperatures, demonstrated a greater penetration depth than its counterpart that was under the steeper temperature gradient. Slag that did not infiltrate into the refractory due to the induced temperature gradient, pooled and solidified on the top of the sample. Within the pool, a conglomerated mass of troilite (FeS) formed separately from the surrounding slag. Microscopy of the cross-sectioned infiltrated refractories revealed that the slag preferentially corroded the matrix regions closer to the top surface. Furthermore, the formation of a thick layer of hercynite (FeAl{sub 2}O{sub 4}) at the top of refractory/slag interface significantly depleted the slag of its iron-oxide content with respect to its virgin composition. A qualitative description of the penetration process is provided in this article.

Kaneko, Tetsuya Kenneth; Bennett, James P.; Dridhar, Seetharaman

2011-12-01T23:59:59.000Z

25

Measurements of Electron Thermal Transport due to Electron Temperature Gradient Modes in a Basic Experiment  

SciTech Connect (OSTI)

Production and identification of electron temperature gradient modes have already been reported [X. Wei, V. Sokolov, and A. K. Sen, Phys. Plasmas 17, 042108 (2010)]. Now a measurement of electron thermal conductivity via a unique high frequency triple probe yielded a value of {chi}{sub perpendiculare} ranging between 2 and 10 m{sup 2}/s, which is of the order of a several gyrobohm diffusion coefficient. This experimental result appears to agree with a value of nonlocal thermal conductivity obtained from a rough theoretical estimation and not inconsistent with gyrokinetic simulation results for tokamaks. The first experimental scaling of the thermal conductivity versus the amplitude of the electron temperature gradient fluctuation is also obtained. It is approximately linear, indicating a strong turbulence signature.

Sokolov, V.; Sen, A. K. [Plasma Research Laboratory, Columbia University, New York, New York 10027 (United States)

2011-10-07T23:59:59.000Z

26

Gyrokinetic and Gyrofluid Models for Zonal Flow Dynamics in Ion and Electron Temperature Gradient Turbulence  

SciTech Connect (OSTI)

Collisionless time evolution of zonal flows in ion and electron temperature gradient turbulence in toroidal plasmas is investigated. The responses of the zonal-flow potential to the initial perturbation and to the turbulence source are determined from the gyrokinetic equations combined with the Poisson equation, A novel gyrofluid model is presented, which properly describes the zonal-flow time evolution and reproduces the same residual zonal-flow levels as predicted by the gyrokinetic model.

Sugama, H.; Watanabe, T.-H. [National Institute for Fusion Science, Toki, Gifu, 509-5292 (Japan); Graduate University for Advanced Studies, Toki, Gifu, 509-5292 (Japan); Ferrando i Margalet, S. [National Institute for Fusion Science, Toki, Gifu, 509-5292 (Japan)

2006-11-30T23:59:59.000Z

27

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

SciTech Connect (OSTI)

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.

Mavridis, M.; Isliker, H.; Vlahos, L. [Section of Astrophysics, Astronomy and Mechanics, Department of Physics, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece); Görler, T.; Jenko, F.; Told, D. [Max Planck Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching (Germany)

2014-10-15T23:59:59.000Z

28

Stability threshold of ion temperature gradient driven mode in reversed field pinch plasmas  

SciTech Connect (OSTI)

For the first time in the reversed field pinch (RFP) configuration, the stability threshold of the ion temperature gradient driven (ITG) mode is studied by linear gyrokinetic theory. In comparison with tokamaks, the RFP configuration has a shorter connection length and stronger magnetic curvature drift. These effects result in a stronger instability driving mechanism and a larger growth rate in the fluid limit. However, the kinetic theory shows that the temperature slopes required for the excitation of ITG instability are much steeper than the tokamak ones. This is because the effect of Landau damping also becomes stronger due to the shorter connection length, which is dominant and ultimately determines the stability threshold. The required temperature slope for the instability may only be found in the very edge of the plasma and/or near the border of the dominant magnetic island during the quasi-single helicity state of discharge.

Guo, S. C. [Consorzio RFX, Associazione Euratom-ENEA sulla fusione, Corso Stati Uniti 4, Padova 35127 (Italy)

2008-12-15T23:59:59.000Z

29

Vertical distribution of larval stages of the horn fly, Haematobia irritans irritans (L.), in relation to manure pat temperature gradients  

E-Print Network [OSTI]

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... in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May 1981 Major Subject: Entomology VERTICAL DISTRIBUTION OF LARVAL STAGES OF THE HORN FLY, HAEMATOBIA IRRITANS IRRITANS (L. ), IN RELATION TO MANURE PAT TEMPERATURE GRADIENTS...

March, Philip Anderson

1981-01-01T23:59:59.000Z

30

THE STELLAR NUMBER DENSITY DISTRIBUTION IN THE LOCAL SOLAR NEIGHBORHOOD IS NORTH-SOUTH ASYMMETRIC  

SciTech Connect (OSTI)

We study the number density distribution of a sample of K and M dwarf stars, matched north and south of the Galactic plane within a distance of 2 kpc from the Sun, using observations from the Ninth Data Release of the Sloan Digital Sky Survey. We determine distances using the photometric parallax method, and in this context systematic effects exist which could potentially impact the determination of the number density profile with height from the Galactic plane—and ultimately affect a number density north-south asymmetry. They include: (1) the calibration of the various photometric parallax relations, (2) the ability to separate dwarfs from giants in our sample, (3) the role of stellar population differences such as age and metallicity, (4) the ability to determine the offset of the Sun from the Galactic plane, and (5) the correction for reddening from dust in the Galactic plane, though our stars are at high Galactic latitudes. We find the various analyzed systematic effects to have a negligible impact on our observed asymmetry, and using a new and larger sample of stars we confirm and refine the earlier discovery of Widrow et al. of a significant Galactic north-south asymmetry in the stellar number density distribution.

Yanny, Brian [Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Gardner, Susan [Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506-0055 (United States)

2013-11-10T23:59:59.000Z

31

Comparison of analytical models for zonal flow generation in ion-temperature-gradient mode turbulence  

SciTech Connect (OSTI)

During the past years the understanding of the multi scale interaction problems have increased significantly. However, at present there exists a flora of different analytical models for investigating multi scale interactions and hardly any specific comparisons have been performed among these models. In this work two different models for the generation of zonal flows from ion-temperature-gradient (ITG) background turbulence are discussed and compared. The methods used are the coherent mode coupling model and the wave kinetic equation model (WKE). It is shown that the two models give qualitatively the same results even though the assumption on the spectral difference is used in the (WKE) approach.

Anderson, J.; Miki, K.; Uzawa, K.; Li, J.; Kishimoto, Y. [Dept. Fundamental Energy Science, School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto, 611-0011 (Japan)

2006-11-30T23:59:59.000Z

32

Gyrokinetic-Vlasov simulations of the ion temperature gradient turbulence in tokamak and helical systems  

SciTech Connect (OSTI)

Recent progress of the gyrokinetic-Vlasov simulations on the ion temperature gradient (ITG) turbulence in tokamak and helical systems is reported, where the entropy balance is checked as a reference for the numerical accuracy. The tokamak ITG turbulence simulation carried out on the Earth Simulator clearly captures a nonlinear generation process of zonal flows. The tera-flops and tera-bytes scale simulation is also applied to a helical system with the same poloidal and toroidal periodicities of L = 2 and M = 10 as in the Large Helical Device.

Watanabe, T.-H.; Sugama, H. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Graduate University for Advanced Studies (Sokendai), Toki, Gifu 509-5292 (Japan); Ferrando i Margalet, S. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan)

2006-11-30T23:59:59.000Z

33

Turbulent electron transport in edge pedestal by electron temperature gradient turbulence  

SciTech Connect (OSTI)

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.

Singh, R. [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of) [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 (India); Jhang, Hogun [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of)] [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Diamond, P. H. [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of) [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); CMTFO and CASS, University of California, San Diego 92093-0424, California (United States)

2013-11-15T23:59:59.000Z

34

Fine-Scale Zonal Flow Suppression of Electron Temperature Gradient Turbulence  

SciTech Connect (OSTI)

It is found in collisionless Electron Temperature Gradient (ETG) turbulence simulations that, while zonal flows are weak at early times, the zonal flows continue to grow algebraically (proportional to time). These fine-scale zonal flows have a radial wave number such that kr{rho}i > 1 and kr{rho}e < 1. Eventually, the zonal flows grow to a level that suppresses the turbulence due to ExB shearing. The final electron energy flux is found to be relatively low. These conclusions are based on particle convergence studies with adiabatic ion electrostatic flux-tube gyrokinetic {delta}f particle simulations run for long times. The Rosenbluth-Hinton random walk mechanism is given as an explanation for the long time build up of the zonal flow in ETG turbulence and it is shown that the generation is (k perpendicular {rho}e)2 smaller than for isomorphic Ion Temperature Gradient (ITG) problem. This mechanism for zonal flow generation here is different than the modulational instability mechanism for ITG turbulence. These results are important because previous results indicated zonal flows were unimportant for ETG turbulence. Weak collisional damping of the zonal flow is also shown to be a n important effect.

Parker, S. E.; Kohut, J. J.; Chen, Y. [Center for Integrated Plasma Studies, University of Colorado, Boulder, C0 (United States); Lin, Z. [University of Californian, Irvine, CA (United States); Hinton, F. L. [Hinton Associates, Escondido, CA (United States); Lee, W. W. [Princeton Plasma Physics Laboratory, Princeton, NJ (United States)

2006-11-30T23:59:59.000Z

35

Grain-scale thermoelastic stresses and spatiotemporal temperature gradients on airless bodies, implications for rock breakdown  

E-Print Network [OSTI]

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...

Molaro, Jamie L; Langer, Steve A

2015-01-01T23:59:59.000Z

36

Ion-temperature-gradient sensitivity of the hydrodynamic instability caused by shear in the magnetic-field-aligned plasma flow  

SciTech Connect (OSTI)

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.

Mikhailenko, V. V., E-mail: vladimir@pusan.ac.kr [Plasma Research Center, Pusan National University, Busan 609-735 (Korea, Republic of); Mikhailenko, V. S. [School of Physics and Technology, V.N. Karazin Kharkiv National University, 61108 Kharkiv (Ukraine); Faculty of Transportation Systems, Kharkiv National Automobile and Highway University, 61002 Kharkiv (Ukraine); Lee, Hae June, E-mail: haejune@pusan.ac.kr [Department of Electrical Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Koepke, M. E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States)

2014-07-15T23:59:59.000Z

37

UNITED STATES DEPARTMENT OF THE INTERIOR u.s. FISH AND WILDLIFE SERVICE  

E-Print Network [OSTI]

, north-south temperature gradient occurs in the western Gulf between Sabine Bank and the Gulf of Campeche

38

The 1983 Temperature Gradient and Heat Flow Drilling Project for the State of Washington  

SciTech Connect (OSTI)

During the Summer of 1983, the Washington Division of Geology and Earth Resources carried out a three-hole drilling program to collect temperature gradient and heat flow information near potential geothermal resource target areas. The project was part of the state-coupled US Department of Energy Geothermal Program. Richardson Well Drilling of Tacoma, Washington was subcontracted through the State to perform the work. The general locations of the project areas are shown in figure 1. The first hole, DNR 83-1, was located within the Green River valley northwest of Mount St. Helens. This site is near the Green River Soda Springs and along the projection of the Mount St. Helens--Elk Lake seismic zone. The other two holes were drilled near Mount Baker. Hole DNR 83-3 was sited about 1/4 km west of the Baker Hot Springs, 10.5 km east of Mount Baker, while hole DNR 83-5 was located along Rocky Creek in the Sulphur Creek Valley. The Rocky Creek hole is about 10 km south-southwest of the peak. Two other holes, DNR 83-2 and DNR 83-4, were located on the north side of the Sulphur Creek Valley. Both holes were abandoned at early stages of drilling because of deep overburden and severe caving problems. The sites were apparently located atop old landslide deposits.

Korosec, Michael A.

1983-11-01T23:59:59.000Z

39

Theory of coupled whistler-electron temperature gradient mode in high beta plasma: Application to linear plasma device  

SciTech Connect (OSTI)

This paper presents a theory of coupled whistler (W) and electron temperature gradient (ETG) mode using two-fluid model in high beta plasma. Non-adiabatic ion response, parallel magnetic field perturbation ({delta}B{sub z}), perpendicular magnetic flutter ({delta}B{sub perpendicular}), and electron collisions are included in the treatment of theory. A linear dispersion relation for whistler-electron temperature gradient (W-ETG) mode is derived. The numerical results obtained from this relation are compared with the experimental results observed in large volume plasma device (LVPD) [Awasthi et al., Phys. Plasma 17, 42109 (2010)]. The theory predicts that the instability grows only where the temperature gradient is finite and the density gradient flat. For the parameters of the experiment, theoretically estimated frequency and wave number of W-ETG mode match with the values corresponding to the peak in the power spectrum observed in LVPD. By using simple mixing length argument, estimated level of fluctuations of W-ETG mode is in the range of fluctuation level observed in LVPD.

Singh, S. K.; Awasthi, L. M.; Singh, R.; Kaw, P. K.; Jha, R.; Mattoo, S. K. [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India)

2011-10-15T23:59:59.000Z

40

An experimental investigaion of seawater/basalt interactions: the role of water/rock ratios and temperature gradients  

E-Print Network [OSTI]

of the quench pH data as a function of temperature in temperature-gradient experiments 38 40 LIST OF PLATES Plate Page Ia Ib I la IIb IIIa IIIb IVa Ivb Va Vb VIa Large euhedral anhydrite crystals surrounded by honeycomb-shaped smectite. Run... circulation. Metabasalts ranging from zeolite to amphibolite facies, with greenstones dominating, have been dredged from the ocean floor (Aumento et al. 1971; Miyashi ro et al. 1971; Melson and van Andel, 1966; Shi do et al. , 1974; Bonatti et al. ; 1975...

Archer, Paul Lawrence

1978-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "north-south temperature gradient" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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to obtain the most current and comprehensive results.


41

Large-scale spatial variability of riverbed temperature gradients in Snake River fall Chinook salmon spawning areas  

SciTech Connect (OSTI)

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.

Hanrahan, Timothy P.

2007-02-01T23:59:59.000Z

42

On the nonlinear stability of a quasi-two-dimensional drift kinetic model for ion temperature gradient turbulence  

E-Print Network [OSTI]

We study a quasi-two-dimensional electrostatic drift kinetic system as a model for near-marginal ion temperature gradient (ITG) driven turbulence. A proof is given of the nonlinear stability of this system under conditions of linear stability. This proof is achieved using a transformation that diagonalizes the linear dynamics and also commutes with nonlinear $E\\times B$ advection. For the case when linear instability is present, a corollary is found that forbids nonlinear energy transfer between appropriately defined sets of stable and unstable modes. It is speculated that this may explain the preservation of linear eigenmodes in nonlinear gyrokinetic simulations. Based on this property, a dimensionally reduced ($\\infty\\times\\infty \\rightarrow 1$) system is derived that may be useful for understanding dynamics around the critical gradient of Dimits.

Plunk, G G

2015-01-01T23:59:59.000Z

43

Why molecules move along a temperature gradient Stefan Duhr, and Dieter Braun  

E-Print Network [OSTI]

and polystyrene beads, thermophoretic motion changes sign at lower temperatures. This thermophilicity toward lower

Kersting, Roland

44

Parametric Excitation of Geodesic Acoustic Modes by Electron Drift Waves and Ion Temperature Gradient Modes in Tokamak Plasmas  

SciTech Connect (OSTI)

Geodesic Acoustic Modes (GAMs) have been predicted and subsequently observed in many toroidal plasma devices. Bicoherence studies on various devices have suggested three-wave mode coupling processes between GAMs and high frequency turbulence. Thus the parametric coupling of GAMS to drift waves and/or ion temperature gradient(ITG{r_brace} modes is a potential candidate for excitation of these modes. In this paper we discuss the resonant three-wave coupling mechanism for the excitation of GAMs by ITG and finite beta drift waves in homogeneous and inhomogeneous plasmas and compare theoretical predictions with observed characteristics of the GAMs.

Guzdar, P. N.; Kleva, R. G. [IREAP, University of Maryland, College Park, MD 20742 (United States); Chakrabarti, N. [SINP, Kolkata (India); Kaw, P. K.; Singh, R. [IPR, Gandhinagar, 308423 (India); Naulin, V.; Rasmussen, J. J. [EURATOM, Roskilde (Denmark)

2008-11-01T23:59:59.000Z

45

Coupling of ion temperature gradient and trapped electron modes in the presence of impurities in tokamak plasmas  

SciTech Connect (OSTI)

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.

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)

2014-05-15T23:59:59.000Z

46

Abstract : 2008 APS-DPP Temperature gradients are supported by cantori in chaotic fields  

E-Print Network [OSTI]

(s)+T(s, , ), where s is a radial coordinate. To(s) is generally a smoothed devil's staircase: flat across exceed 1010 . The temperature adapts to the fractal structure of the magnetic field. To show the connection between the fractal structure of the magnetic field and the near-fractal structure

Hudson, Stuart

47

Measuring LCSTs by Novel Temperature Gradient Methods: Evidence for Intermolecular Interactions in Mixed Polymer Solutions  

E-Print Network [OSTI]

the precipitation mechanisms are often complex, it is generally accepted that the desorption of water molecules from the temperature along the tube was a simple matter of measuring the lengthwise position. As a demonstration inverted microscope by employing dark field microscopy (Figure 2). Interestingl

48

Momentum transport in the vicinity of q{sub min} in reverse shear tokamaks due to ion temperature gradient turbulence  

SciTech Connect (OSTI)

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.

Singh, Rameswar, E-mail: rameswar@ipr.res.in [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India) [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India); Laboratoire de Physique des Plasmas, Ecole Polytechnique route de Saclay, 91128 Palaiseau Cedex (France); Singh, R [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India) [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India); WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Jhang, Hogun [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of)] [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Diamond, P. H. [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of) [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Center for Momentum Transport and Flow Organization, University of California, San Diego, California 92093 (United States); Center for Astrophysics and Space Sciences, University of California San Diego, 9500 Gilman Dr., La Jolla, California 92093-0424 (United States)

2014-01-15T23:59:59.000Z

49

Outgassing, Temperature Gradients and the Radiometer Effect in LISA: A Torsion Pendulum Investigation  

E-Print Network [OSTI]

Thermal modeling of the LISA gravitational reference sensor (GRS) includes such effects as outgassing from the proof mass and its housing and the radiometer effect. Experimental data in conditions emulating the LISA GRS are required to confidently predict the GRS performance. Outgassing and the radiometer effect are similar in characteristics and are difficult to decouple experimentally. The design of our torsion balance allows us to investigate differential radiation pressure, the radiometer effect, and outgassing on closely separated conducting surfaces with high sensitivity. A thermally controlled split copper plate is brought near a freely hanging plate-torsion pendulum.We have varied the temperature on each half of the copper plate and have measured the resulting forces on the pendulum. We have determined that to first order the current GRS model for the radiometer effect, outgassing, and radiation pressure are mostly consistent with our torsion balance measurements and therefore these thermal effects do not appear to be a large hindrance to the LISA noise budget. However, there remain discrepancies between the predicted dependence of these effects on the temperature of our apparatus.

Scott E Pollack; Stephan Schlamminger; Jens H Gundlach

2007-02-08T23:59:59.000Z

50

Statistical mechanical theory for the structure of steady state systems: Application to a Lennard-Jones fluid with applied temperature gradient  

E-Print Network [OSTI]

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

Attard, Phil

51

A circular equilibrium model for local gyrokinetic simulations of ion temperature gradient fluctuations in reversed field pinches  

SciTech Connect (OSTI)

A simple large-aspect-ratio (R{sub 0}/r) circular equilibrium model is developed for low-beta reversed field pinch (RFP) geometry. The model is suitable for treating small scale instability and turbulent transport driven by ion temperature gradient (ITG) and related electron drift modes in gyrokinetic simulations. The equilibrium model is an RFP generalization of the common tokamak s-{alpha} model to small safety factor (q), where the poloidal field dominates the toroidal field. The model accommodates the RFP toroidal field reversal (where q vanishes) by generalizing the cylindrical force-free Bessel function model (BFM) [J. B. Taylor, Phys. Rev. Lett. 33, 1139 (1974)] to toroidal geometry. The global equilibrium can be described in terms of the RFP field reversal and pinch parameters [F,{Theta}]. This new toroidal Bessel function model (TBFM) has been incorporated into the gyrokinetic code GYRO [J. Candy and R. E. Waltz, J.Comput. Phys. 186, 545 (2003)] and used here to explore local electrostatic ITG adiabatic electron instability rates for typical low-q RFP parameters.

Tangri, Varun; Terry, P. W. [Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706R (United States); Waltz, R. E. [General Atomics, San Diego, California 92186 (United States)

2011-05-15T23:59:59.000Z

52

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

E-Print Network [OSTI]

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 ...

Kadri, Romi Sinclair

2014-01-01T23:59:59.000Z

53

North-South Universittsspital  

E-Print Network [OSTI]

global P-cycling through intense use of phosphate rock products,primarily as mineral fertiliser. In fact-South Forum Phosphorus ­ A bottleneck of nature Phosphorus: Pollution, resource scarcity and its implications in the fields of global change and sustainable development. Encompassing a network of over 400 researchers

Richner, Heinz

54

North South Forum Boniface Kiteme  

E-Print Network [OSTI]

: Overview and Introduction #12;Graph created from the data in the BP 2006 statistical review 4. Increasing (higher) energy consumption and prices I: Overview and Introduction #12;5. Climate change I: Overview: Basically and largely sectoral Greatly north driven through funding arrangements 4. The Reality Tertiary

Richner, Heinz

55

Introduction Conjugate Gradient Method  

E-Print Network [OSTI]

Introduction Conjugate Gradient Method Deflation Domain Decomposition Research Master Thesis Presentation #12;Introduction Conjugate Gradient Method Deflation Domain Decomposition Research Plaxis Finite Kaliszka Master Thesis Literature Study Presentation #12;Introduction Conjugate Gradient Method Deflation

Vuik, Kees

56

Simplified modeling of liquid sodium medium with temperature and velocity gradient using real thermal-hydraulic data. Application to ultrasonic thermometry in sodium fast reactor  

SciTech Connect (OSTI)

In the framework of the French R and D program for the Generation IV reactors and specifically for the sodium cooled fast reactors (SFR), studies are carried out on innovative instrumentation methods in order to improve safety and to simplify the monitoring of fundamental physical parameters during reactor operation. The aim of the present work is to develop an acoustic thermometry method to follow up the sodium temperature at the outlet of subassemblies. The medium is a turbulent flow of liquid sodium at 550 Degree-Sign C with temperature inhomogeneities. To understand the effect of disturbance created by this medium, numerical simulations are proposed. A ray tracing code has been developed with Matlab Copyright-Sign in order to predict acoustic paths in this medium. This complex medium is accurately described by thermal-hydraulic data which are issued from a simulation of a real experiment in Japan. The analysis of these results allows understanding the effects of medium inhomogeneities on the further thermometric acoustic measurement.

Massacret, N.; Jeannot, J. P. [DEN/DTN/STPA/LIET, CEA Cadarache, Saint Paul Lez Durance (France); Moysan, J.; Ploix, M. A.; Corneloup, G. [Aix-Marseille Univ, LMA UPR 7051 CNRS, site LCND, 13625 Aix-en-Provence (France)

2013-01-25T23:59:59.000Z

57

The ISO Galactic Metallicity Gradient Revisited  

E-Print Network [OSTI]

Two independent groups (Giveon et al. 2002; Martin-Hernandez et al. 2002) have recently investigated the Galactic metallicity gradient as probed by ISO observations of mid-infrared emission lines from HII regions. We show that the different gradients inferred by the two groups are due to differing source selection and differing extinction corrections. We show that both data sets in fact provide consistent results if identical assumptions are made in the analysis. We present a consistent set of gradients in which we account for extinction and variation in electron temperature across the disk.

Uriel Giveon; Christophe Morisset; Amiel Sternberg

2002-07-22T23:59:59.000Z

58

Converting Level Set Gradients to Shape Gradients  

E-Print Network [OSTI]

distance function (SDF) associated with a shape, and differentiate these energies with respect to the SDF to the SDF. We discuss some problematic gradients from the literature, show how they can easily be fixed function (SDF) of , i.e. the function that associates any point x with the signed distance (x) = ±d

Radke, Rich

59

Fast Self-Healing Gradients  

E-Print Network [OSTI]

We present CRF-Gradient, a self-healing gradient algorithm that provably reconfigures in O(diameter) time. Self-healing gradients are a frequently used building block for distributed self-healing systems, but previous ...

Beal, Jacob

60

Inverse estimation of surface heating condition in a three-dimensional object using conjugate gradient method  

E-Print Network [OSTI]

heat conduction Laser Gaussian profile Conjugate gradient method a b s t r a c t Temperature and heat gradient method Jianhua Zhou, Yuwen Zhang *, J.K. Chen, Z.C. Feng Department of Mechanical and Aerospace gradient method (CGM) with temperature and heat flux measured on back surface (opposite to the heated

Zhang, Yuwen

Note: This page contains sample records for the topic "north-south temperature gradient" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Conjugate Gradient Method Numerisches Rechnen  

E-Print Network [OSTI]

Conjugate Gradient Method Numerisches Rechnen (für Informatiker) M. Grepl J. Berger & J.T. Frings Numerisches Rechnen #12;Conjugate Gradient Method The Quadratic Form Steepest Descent Conjugate Directions/Gradients IGPM, RWTH Aachen Numerisches Rechnen #12;Conjugate Gradient Method The Quadratic Form Steepest Descent

62

Temperature, heat flow maps and temperature gradient holes | Open Energy  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revisionEnvReviewNonInvasiveExplorationUT-gTaguspark Jump to: navigation,Telluric Survey Details

63

Conjugate Gradient Methods in Confirmatory Factor Analysis  

E-Print Network [OSTI]

R. I. (1988), "Conjugate Gradient Methods in Confirmatoryapply generalized conjugate gradient methods in an attemptby used. The conjugate gradient method, which is simple and

Jamshardian, Mortaza; Jennrich, Robert

1993-01-01T23:59:59.000Z

64

Conjugate Gradient Acceleration of the EM Algorithm  

E-Print Network [OSTI]

R. I. (1988), "Conjugate Gradient Methods in Confirmatoryapply generalized conjugate gradient methods in an attemptby used. The conjugate gradient method, which is simple and

Mortaza Jamshidian; Robert Jennrich

2011-01-01T23:59:59.000Z

65

Energy in density gradient  

E-Print Network [OSTI]

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

Vranjes, J

2015-01-01T23:59:59.000Z

66

Hierarchically deflated conjugate gradient  

E-Print Network [OSTI]

We present a multi-level algorithm for the solution of five dimensional chiral fermion formulations, including domain wall and Mobius Fermions. The algorithm operates on the red-black preconditioned Hermitian operator, and directly accelerates conjugate gradients on the normal equations. The coarse grid representation of this matrix is next-to-next-to-next-to-nearest neighbour and multiple algorithmic advances are introduced, which help minimise the overhead of the coarse grid. The treatment of the coarse grids is purely four dimensional, and the bulk of the coarse grid operations are nearest neighbour. The intrinsic cost of most of the coarse grid operations is therefore comparable to those for the Wilson case. We also document the implementation of this algorithm in the BAGEL/Bfm software package and report on the measured performance gains the algorithm brings to simulations at the physical point on IBM BlueGene/Q hardware.

P A Boyle

2014-02-11T23:59:59.000Z

67

Gradient Sliding for Composite Optimization  

E-Print Network [OSTI]

Noname manuscript No. (will be inserted by the editor). Gradient Sliding for Composite Optimization. Guanghui Lan the date of receipt and acceptance should ...

2014-06-11T23:59:59.000Z

68

Global energy gradients and size in colonial organisms: Worker mass and worker number  

E-Print Network [OSTI]

Global energy gradients and size in colonial organisms: Worker mass and worker number in ant size varies globally is a key challenge to ecology. Solar energy may shape gradients of body size by its effects on local temperature and net primary productivity (16­20). Rising global temperatures (21

Kaspari, Mike

69

Gradient elution in capillary electrochromatography  

SciTech Connect (OSTI)

In analogy to pressure-driven gradient techniques in high-performance liquid chromatography, a system has been developed for delivering electroosmotically-driven solvent gradients for capillary electrochromatography (CEC). Dynamic gradients with sub-mL/min flow rates are generated by merging two electroosmotic flows that are regulated by computer-controlled voltages. These flows are delivered by two fused-silica capillary arms attached to a T-connector, where they mix and then flow into a capillary column that has been electrokinetically packed with 3-mm reversed-phase particles. The inlet of one capillary arm is placed in a solution reservoir containing one mobile phase and the inlet of the other is placed in a second reservoir containing a second mobile phase. Two independent computer-controlled programmable high-voltage power supplies (0-50 kV)--one providing an increasing ramp and the other providing a decreasing ramp--are used to apply variable high-voltage potentials to the mobile phase reservoirs to regulate the electroosmotic flow in each arm. The ratio of the electroosmotic flow rates between the two arms is changed with time according to the computer-controlled voltages to deliver the required gradient profile to the separation column. Experiments were performed to confirm the composition of the mobile phase during a gradient run and to determine the change of the composition in response to the programmed voltage profile. To demonstrate the performance of electroosmotically-driven gradient elution in CEC, a mixture of 16 polycyclic aromatic hydrocarbons (PAHs) was separated in less than 90 minutes. This gradient technique is expected to be well-suited for generating not only solvent gradients in CEC, but also other types of gradients such as pH- and ionic-strength gradients in capillary electrokinetic separations and analyses.

Anex, D.; Rakestraw, D.J. [Sandia National Labs., Livermore, CA (United States); Yan, Chao; Dadoo, R.; Zare, R.N. [Stanford Univ., CA (United States). Dept. of Chemistry

1997-08-01T23:59:59.000Z

70

Block-conjugate-gradient method  

SciTech Connect (OSTI)

It is shown that by using the block-conjugate-gradient method several, say {ital s}, columns of the inverse Kogut-Susskind fermion matrix can be found simultaneously, in less time than it would take to run the standard conjugate-gradient algorithm {ital s} times. The method improves in efficiency relative to the standard conjugate-gradient algorithm as the fermion mass is decreased and as the value of the coupling is pushed to its limit before the finite-size effects become important. Thus it is potentially useful for measuring propagators in large lattice-gauge-theory calculations of the particle spectrum.

McCarthy, J.F. (Department of Physics, Indiana University, Bloomington, Indiana 47405 (US))

1989-09-15T23:59:59.000Z

71

High field gradient particle accelerator  

DOE Patents [OSTI]

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 is disclosed. 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. 10 figs.

Nation, J.A.; Greenwald, S.

1989-05-30T23:59:59.000Z

72

High field gradient particle accelerator  

DOE Patents [OSTI]

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.

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

1989-01-01T23:59:59.000Z

73

CONJUGATE GRADIENT WITH SUBSPACE OPTIMIZATION 1 ...  

E-Print Network [OSTI]

last update. Unlike some other conjugate gradient methods, our algorithm attains a theoretical ... The method of conjugate gradients (CG) was introduced by.

2011-12-25T23:59:59.000Z

74

Pumpernickel Valley Geothermal Project Thermal Gradient Wells  

SciTech Connect (OSTI)

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

Z. Adam Szybinski

2006-01-01T23:59:59.000Z

75

Geothermal: Sponsored by OSTI -- Temperatures and intervalgeothermal...  

Office of Scientific and Technical Information (OSTI)

Temperatures and interval geothermal-gradient determinations from wells in National Petroleum Reserve in Alaska Geothermal Technologies Legacy Collection HelpFAQ | Site Map |...

76

Human Appropriation of Net Primary Productivity (HANPP) in Texas: A Statewide Analysis of Sustainability in the Agricultural and Timber Sectors  

E-Print Network [OSTI]

in the Panhandle offer shorter growing seasons due to temperature limitations; approximately 5-10?C less than the Gulf Coast Regions (National Oceanic 14 and Atmospheric Administration 2008). In west Texas NPP is limited by water availability without human...). In Texas there is therefore a strong north- south gradient controlled by temperature and an east-west gradient controlled by moisture. Available solar radiation also controls NPP. Nemani et al. (2003) illustrated this by correlating how a decrease...

Graff, Christopher P.

2010-07-14T23:59:59.000Z

77

Variable metric conjugate gradient methods  

SciTech Connect (OSTI)

1.1 Motivation. In this paper we present a framework that includes many well known iterative methods for the solution of nonsymmetric linear systems of equations, Ax = b. Section 2 begins with a brief review of the conjugate gradient method. Next, we describe a broader class of methods, known as projection methods, to which the conjugate gradient (CG) method and most conjugate gradient-like methods belong. The concept of a method having either a fixed or a variable metric is introduced. Methods that have a metric are referred to as either fixed or variable metric methods. Some relationships between projection methods and fixed (variable) metric methods are discussed. The main emphasis of the remainder of this paper is on variable metric methods. In Section 3 we show how the biconjugate gradient (BCG), and the quasi-minimal residual (QMR) methods fit into this framework as variable metric methods. By modifying the underlying Lanczos biorthogonalization process used in the implementation of BCG and QMR, we obtain other variable metric methods. These, we refer to as generalizations of BCG and QMR.

Barth, T.; Manteuffel, T.

1994-07-01T23:59:59.000Z

78

Gas Exchange, Partial Pressure Gradients,  

E-Print Network [OSTI]

Gas Exchange, Partial Pressure Gradients, and the Oxygen Window Johnny E. Brian, Jr., M of circulatory and gas transport physiology, and the best place to start is with normobaric physiology. LIFE affect the precise gas exchange occurring in individual areas of the lungs and body tissues. To make

Riba Sagarra, Jaume

79

Geosynthetics in a salinity-gradient solar pond environment  

SciTech Connect (OSTI)

This paper describes the latest in salinity-gradient solar pond lining systems. The high-temperature, high-salinity environment unique to a salinity-gradient solar pond resulted in failure of the geomembrane liner at the El Paso Solar Pond Test Facility after only eight years of operation. Research involved in pond reconstruction led to the selection of a lining system consisting of a flexible polypropylene (PP) geomembrane for the sidewalls and a specially formulated geosynthetic clay liner (GCL) on the bottom of the pond. The two liners have been installed and a comprehensive test program is being conducted to measure their performance. The environment encountered in a salinity-gradient solar pond will be discussed as well as material selection criteria and the design of the two liners. Preliminary results of the GCL performance monitoring will also be presented.

Lichwardt, M.A.; Comer, A.I.

1997-11-01T23:59:59.000Z

80

Novel concepts in weld science: Role of gradients and composite structure. Final report  

SciTech Connect (OSTI)

The effects of compositional and microstructural gradients on weld metal and simulated weld metal properties were evaluated in this multi-part study. The results obtained on single phase solid solution systems were used as a basis for a fundamental study of the effects of compositional gradients on crack growth, both at low temperatures, in fatigue and at high temperatures during creep. Methods to physically simulate gradients in weld metals with roll bonded laminate composites were applied to analyses of ferrite-austenite and ferrite-sigma-austenite multiphase systems. Finally, results of the physical simulation analyses were utilized to predict the effects of weld process parameters on weld metal properties.

Matlock, D.K.; Olson, D.L.

1994-03-01T23:59:59.000Z

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


81

Conjugate Gradient Algorithms Using Multiple Recursions  

E-Print Network [OSTI]

of Colorado Much is already known about when a conjugate gradient method can be implemented with short and sufficient conditions on the iteration matrix A, in order for a conjugate gradient method to be implemented that the conjugate gradient method for unitary and shifted unitary matrices can be implemented using a single short

82

An Introduction to the Conjugate Gradient Method  

E-Print Network [OSTI]

An Introduction to the Conjugate Gradient Method Without the Agonizing Pain Edition 11 4 Jonathan Abstract The Conjugate Gradient Method is the most prominent iterative method for solving sparse systems, the Conjugate Gradient Method is a composite of simple, elegant ideas that almost anyone can understand

Zhang, Yi

83

An Introduction to the Conjugate Gradient Method  

E-Print Network [OSTI]

An Introduction to the Conjugate Gradient Method Without the Agonizing Pain Edition 1 1 4 Jonathan Abstract The Conjugate Gradient Method is the most prominent iterative method for solving sparse systems, the Conjugate Gradient Method is a composite of simple, elegant ideas that almost anyone can understand

Shewchuk, Jonathan

84

Porting the NAS-NPB Conjugate Gradient  

E-Print Network [OSTI]

.kr/Center_for_Manycore_Programming/SNU_NPB_Suite.html NPB Benchmarks #12;! "A conjugate gradient method is used to compute an approximation to the smallestPorting the NAS-NPB Conjugate Gradient Benchmark to CUDA NVIDIA Corporation #12;Outline ! Overview coding methodologies and architectures. ! Suite of benchmarks: ! Integer Sort ! Conjugate Gradient ! CFD

Crawford, T. Daniel

85

Accurate conjugate gradient methods for shifted systems  

E-Print Network [OSTI]

Accurate conjugate gradient methods for shifted systems by Jasper van den Eshof and Gerard L. G CONJUGATE GRADIENT METHODS FOR SHIFTED SYSTEMS JASPER VAN DEN ESHOF AND GERARD L. G. SLEIJPEN Abstract We present an efficient and accurate variant of the conjugate gradient method for solving families of shifted

Sleijpen, Gerard

86

A parallel scaled conjugate-gradient  

E-Print Network [OSTI]

. The scaled conjugate- gradient method is a powerful technique for solving large sparse linear systems for form-factor computation. Key words: Gathering radiosity -- Scaled conjugate-gradient method -- Parallel, the Gauss--Jacobi (GJ) method is used in the solution phase. The scaled conjugate-gradient (SCG) method

Aykanat, Cevdet

87

An Introduction to the Conjugate Gradient Method  

E-Print Network [OSTI]

An 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 the mumblings of their forebears. Nevertheless, the Conjugate Gradient Method is a composite of simple, elegant

88

Accurate conjugate gradient methods for shifted systems  

E-Print Network [OSTI]

Accurate conjugate gradient methods for shifted systems by Jasper van den Eshof and Gerard L. G CONJUGATE GRADIENT METHODS FOR SHIFTED SYSTEMS JASPER VAN DEN ESHOF # AND GERARD L. G. SLEIJPEN # Abstract We present an e#cient and accurate variant of the conjugate gradient method for solving families

Sleijpen, Gerard

89

Bayesian Policy Gradient and Actor-Critic Algorithms Bayesian Policy Gradient and Actor-Critic Algorithms  

E-Print Network [OSTI]

Bayesian Policy Gradient and Actor-Critic Algorithms Bayesian Policy Gradient and Actor Yaakov Engel yakiengel@gmail.com Editor: Abstract Policy gradient methods are reinforcement learning algorithms that adapt a param- eterized policy by following a performance gradient estimate. Many

Paris-Sud XI, Université de

90

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

Open Energy Info (EERE)

Drilling At Marine Corps Air-Ground Combat Center (Mcagcc), Twenty-Nine Palms, Ca Abstract The U.S. Navy's Geothermal Program Office (GPO) has been conducting geothermal...

91

Field Investigations And Temperature-Gradient Drilling At Marine Corps  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision has beenFfe2fb55-352f-473b-a2dd-50ae8b27f0a6 NoSan Leandro,LawFEMAProjectExpressFeltonAir-Ground Combat

92

Geology and Temperature Gradient Surveys Blue Mountain Geothermal  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision has beenFfe2fb55-352f-473b-a2dd-50ae8b27f0a6TheoreticalFuelCellGemini SolarAssetsofLane:Discovery,

93

Shape reconstruction from gradient data  

SciTech Connect (OSTI)

We present a generalized method for reconstructing the shape of an object from measured gradient data. A certain class of optical sensors does not measure the shape of an object but rather its local slope. These sensors display several advantages, including high information efficiency, sensitivity, and robustness. For many applications, however, it is necessary to acquire the shape, which must be calculated from the slopes by numerical integration. Existing integration techniques show drawbacks that render them unusable in many cases. Our method is based on an approximation employing radial basis functions. It can be applied to irregularly sampled, noisy, and incomplete data, and it reconstructs surfaces both locally and globally with high accuracy.

Ettl, Svenja; Kaminski, Juergen; Knauer, Markus C.; Haeusler, Gerd

2008-04-20T23:59:59.000Z

94

Compensated geothermal gradient: new map of old data  

SciTech Connect (OSTI)

Bottom-hole temperature measurement is one of the oldest forms of downhole information acquired by the oil industry. Old and new geothermal maps that are based on these measurements have invariably been drawn with an assumed constant or average ground surface temperature over the mapped areas. However, near ground-surface equilibrium temperature is a variable rather than a constant over any region; therefore, old and current geothermal gradient mapping methods give a false impression of the true thermal level of subsurface strata, and may lead to erroneous results of temperature-based calculations, such as the TTI. In this paper, a geothermal mapping method is presented in which extrapolated surface temperature is coupled with the corresponding geothermal gradient over the mapped area. The method was tested on areas in the Middle East and Africa. Results indicate that it is especially effective in delineating loci of vertical geothermal heat flux carried upwards by ascending subsurface fluids; such areas are preferential sites for hydrocarbon entrapment, especially in young sedimentary basins where migration is still in progress.

Ibrahim, M.W.

1986-05-01T23:59:59.000Z

95

Optimization Online - A Nonlinear Conjugate Gradient Algorithm ...  

E-Print Network [OSTI]

Jun 28, 2011 ... Abstract: In this paper, we seek the conjugate gradient direction closest to the direction of the scaled memoryless BFGS method and propose a ...

Yu-Hong Dai

2011-06-28T23:59:59.000Z

96

A GLOBALLY CONVERGENT MODIFIED CONJUGATE-GRADIENT ...  

E-Print Network [OSTI]

based upon applying modified variants of either PCG or Lanczos method to the sys- ... conjugate-gradient based strategies for optimizing a constrained ...

2009-10-01T23:59:59.000Z

97

Optimization Online - An Accelerated Proximal Coordinate Gradient ...  

E-Print Network [OSTI]

Jul 7, 2014 ... An Accelerated Proximal Coordinate Gradient Method and its Application to Regularized Empirical Risk Minimization. Qihang Lin(qihang-lin ...

Qihang Lin

2014-07-07T23:59:59.000Z

98

Optimization of synchronization in gradient clustered networks  

E-Print Network [OSTI]

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.

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

2007-11-23T23:59:59.000Z

99

Geothermal gradient map of the conterminous United States. Second edition  

SciTech Connect (OSTI)

The second edition of the Geothermal Gradient Map of the Conterminous United States (Kron and Stix 1982) is described and the changes made since the first edition (Kron and Heiken 1980) are compared. The second edition of the map presents a compilation of over 1700 wells that have been measured for temperature belwo 50 m and whose temperature/depth profiles are linear, or composed of linear segments which reflect changes in the thermal conductivity of the rocks rather than hydrology. The data are displayed at an enlarged scale of 1:2,500,000 and in a new format which shows the location, depth, and gradient of each well in a single color-coded symbol. This edition contains over two times the amount of data shown on the first map and is accompained by a table, listing for each well its location, depth, gradient, heat flow (where available), thermal conductivity (where available), and a reference. Over 200 references have been consulted and are presented with the data.

Kron, A.; Stix, J.

1982-01-01T23:59:59.000Z

100

north-south,100m east-west, 100m  

E-Print Network [OSTI]

the identification of self-sustaining populations. Use of molecular genetic markers can aid in this identification with increasing age of a stand. Thus spatial genetic bubble Materials and Methods For DNA isolation one leaf position of Bolivar Co. (large triangle) population between the Delta NF and Arkansas populations. Other

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


101

Energy, Engineering, Arts and other subjects: North/South  

E-Print Network [OSTI]

integrated utility with generation, supply, transmission and distribution network businesses that bring company on the island of Ireland, are offering five scholarships to students undertaking a recognised to help build all-island innovation in STEM subjects (science, technology, engineering and mathematics

102

NCCR North-South Centre for Development and Environment (CDE)  

E-Print Network [OSTI]

, where poor sanitation services and water pollution continue to cause health prob- lems. Ahead reports putting forth practical so- lutions to sanitation problems. The current system of centralised sanitation in urban centres in Southeast Asia. Further policy recommenda- tions on wastewater management can

Richner, Heinz

103

arctic vegetation damage: Topics by E-print Network  

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

gradient. Here we examine the complex interrelationships between patterned ground, climate, vegetation and soil along a north-south transect through all five bioclimate...

104

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

SciTech Connect (OSTI)

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.

Olander, D.R.

1984-08-01T23:59:59.000Z

105

Approximate error conjugation gradient minimization methods  

DOE Patents [OSTI]

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.

Kallman, Jeffrey S

2013-05-21T23:59:59.000Z

106

Surface Temperature and Surface-Layer Turbulence in a Convective Boundary Layer  

E-Print Network [OSTI]

The vertical gradient of horizontal wind-speed was estimateda larger vertical gradient of horizontal wind-speed in thewind speed, direction, temperature, humidity up to 20 km with a vertical

Garai, Anirban; Pardyjak, Eric; Steeneveld, Gert-Jan; Kleissl, Jan

2013-01-01T23:59:59.000Z

107

Characterization of Min-K TE-1400 Thermal Insulation (Two-Year Gradient Stress Relaxation Testing Update)  

SciTech Connect (OSTI)

Min-K 1400TE insulation material was characterized at Oak Ridge National Laboratory for use in structural applications under gradient temperature conditions. A previous report (ORNL/TM-2008/089) discusses the testing and results from the original three year duration of the project. This testing included compression testing to determine the effect of sample size and test specimen geometry on the compressive strength of Min-K, subsequent compression testing on cylindrical specimens to determine loading rates for stress relaxation testing, isothermal stress relaxation testing, and gradient stress relaxation testing. This report presents the results from the continuation of the gradient temperature stress relaxation testing and the resulting updated modeling.

Hemrick, James Gordon [ORNL; Lara-Curzio, Edgar [ORNL; King, James [ORNL

2009-09-01T23:59:59.000Z

108

Time changes in gradient and observed winds  

E-Print Network [OSTI]

TIME CHANGES IN GRADIENT AND OBSERVED WINDS A Thesis by RONALD DALE CARLSON Submitted to the Graduate College of Texas A&M University in partial fulfillm=n of the requirement for the degree of MASTER OF SCIENCE MAY 1972 Major Subject...: Meteorology TIME CHANGES IN GRADIENT AND OBSERVED WINDS A Thesis by RONALD D. CARLSON Approved as to style and content by: (Chairman of Co , ee) (Member) (Member) May 1972 ABSTRACT Time Changes in Gradient and Observed Winds. (May 1972) Ronald Dale...

Carlson, Ronald Dale

1972-01-01T23:59:59.000Z

109

Measurement of thermodynamics using gradient flow  

E-Print Network [OSTI]

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.

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

2014-12-15T23:59:59.000Z

110

THE MULTIGRID PRECONDITIONED CONJUGATE GRADIENT METHOD Osamu Tatebe  

E-Print Network [OSTI]

THE MULTIGRID PRECONDITIONED CONJUGATE GRADIENT METHOD Osamu Tatebe Department of Information Science University of Tokyo Tokyo, JAPAN SUMMARY A multigrid preconditioned conjugate gradient method iterations and the multigrid preconditioner is a desirable preconditioner of the conjugate gradient method. 1

111

Separation of carbon nanotubes in density gradients  

DOE Patents [OSTI]

The separation of single-walled carbon nanotubes (SWNTs), by chirality and/or diameter, using centrifugation of compositions of SWNTs in and surface active components in density gradient media.

Hersam, Mark C. (Evanston, IL); Stupp, Samuel I. (Chicago, IL); Arnold, Michael S. (Northbrook, IL)

2012-02-07T23:59:59.000Z

112

Separation of carbon nanotubes in density gradients  

DOE Patents [OSTI]

The separation of single-walled carbon nanotubes (SWNTs), by chirality and/or diameter, using centrifugation of compositions of SWNTs in and surface active components in density gradient media.

Hersam, Mark C. (Evanston, IL); Stupp, Samuel I. (Chicago, IL); Arnold, Michael S. (Northbrook, IL)

2010-02-16T23:59:59.000Z

113

A globally convergent modified conjugate-gradient line-search ...  

E-Print Network [OSTI]

Sep 23, 2009 ... Further, we provide a new variant of modified conjugate gradient algorithms ... optimization, trust region methods, conjugate gradient method.

Wenwen Zhou

2009-09-23T23:59:59.000Z

114

Conjugate gradient methods based on secant conditions that ...  

E-Print Network [OSTI]

Sep 28, 2011 ... (2001) proposed a conjugate gradient method based on the secant ... Recently, the conjugate gradient method is paid attention to as an ...

2011-09-28T23:59:59.000Z

115

An inexact accelerated proximal gradient method for large scale ...  

E-Print Network [OSTI]

projected gradient method, and usually has good practical performance on .... conditioned, the conjugate gradient (CG) method would have great difficulty in ...

2011-09-09T23:59:59.000Z

116

On the regularizing behavior of recent gradient methods in the ...  

E-Print Network [OSTI]

Jun 14, 2014 ... On the regularizing behavior of recent gradient methods in the ... can be competitive with the Conjugate Gradient (CG) method, since they are ...

Roberta De Asmundis

2014-06-14T23:59:59.000Z

117

a perry descent conjugate gradient method with restricted spectrum ...  

E-Print Network [OSTI]

A new nonlinear conjugate gradient method, based on Perry's ... Key words and phrases. large scale optimization, conjugate gradient method, descent property ...

2011-05-09T23:59:59.000Z

118

An efficient gradient method using the Yuan steplength  

E-Print Network [OSTI]

Abstract We propose a new gradient method for quadratic programming, named SDC, .... We note that although the Conjugate Gradient (CG) method is still the ...

2014-05-29T23:59:59.000Z

119

Comparative systems biology across an evolutionary gradient within...  

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

systems biology across an evolutionary gradient within the Shewanella genus . Comparative systems biology across an evolutionary gradient within the Shewanella genus . Abstract: To...

120

TitleA Spectroscopy Diagnostic of Plasma Gradients in ICF Imploded Cores  

E-Print Network [OSTI]

TitleA Spectroscopy Diagnostic of Plasma Gradients in ICF Imploded Cores I. Golovkin, R. Mancini, S to be a powerful diagnostic of spatially-averaged temperature and density plasma conditions at the collapse of ICF-broadened line shapes. The next step in the spectroscopy of imploded cores is the bracketing of core plasma

Louis, Sushil J.

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


121

Elevated temperature crack propagation  

SciTech Connect (OSTI)

This paper is a summary of two NASA contracts on high temperature fatigue crack propagation in metals. The first evaluated the ability of fairly simple nonlinear fracture parameters to correlate crack propagation. Hastelloy-X specimens were tested under isothermal and thermomechanical cycling at temperatures up to 980 degrees C (1800 degrees F). The most successful correlating parameter was the crack tip opening displacement derived from the J-integral. The second evaluated the ability of several path-independent integrals to correlate crack propagation behavior. Inconel 718 specimens were tested under isothermal, thermomechanical, temperature gradient, and creep conditions at temperatures up to 650 degrees C (1200 degrees F). The integrals formulated by Blackburn and by Kishimoto correlated the data reasonably well under all test conditions.

Orange, T.W.

1994-02-01T23:59:59.000Z

122

Penrose Well Temperatures  

SciTech Connect (OSTI)

Penrose Well Temperatures Geothermal waters have been encountered in several wells near Penrose in Fremont County, Colorado. Most of the wells were drilled for oil and gas exploration and, in a few cases, production. This ESRI point shapefile utilizes data from 95 wells in and around the Penrose area provided by the Colorado Oil and Gas Conservation Commission (COGCC) database at http://cogcc.state.co.us/ . Temperature data from the database were used to calculate a temperature gradient for each well. This information was then used to estimate temperatures at various depths. Projection: UTM Zone 13 NAD27 Extent: West -105.224871 East -105.027633 North 38.486269 South 38.259507 Originators: Colorado Oil and Gas Conservation Commission (COGCC) Karen Christopherson

Christopherson, Karen

2013-03-15T23:59:59.000Z

123

Electric field gradient, generalized Sternheimer shieldings and electric field gradient polarizabilities by multiconfigurational SCF response  

E-Print Network [OSTI]

Electric field gradient, generalized Sternheimer shieldings and electric field gradient at the nuclei, the generalized Sternheimer shielding constants and the EFG electric dipole polarizabilities discussed by Egstro¨m and co-workers4 and recently in a more general way by Fowler and co-workers.5

Helgaker, Trygve

124

Ch. VII, Temperature, heat flow maps and temperature gradient holes | Open  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 NoPublic Utilities Address: 160Benin:Energy Information on PV2009 | OpenCeradyne Inc Jump to:CerionEnergyEnergy

125

TOWARDS STOCHASTIC CONJUGATE GRADIENT METHODS Nicol N. Schraudolph Thore Graepel  

E-Print Network [OSTI]

TOWARDS STOCHASTIC CONJUGATE GRADIENT METHODS Nicol N. Schraudolph Thore Graepel schraudo of conjugate gradients provides a very effective way to optimize large, deterministic systems by gradient de. Here we explore a number of ways to adopt ideas from conjugate gradient in the stochastic setting

Schraudolph, Nicol N.

126

Relationship between gradient and EM steps in latent variable models.  

E-Print Network [OSTI]

includes random search, standard gradient­based algorithms, line search methods such as conjugate gradient to to first order method operat­ ing on the gradient of a locally reshaped likelihood function. DirectRelationship between gradient and EM steps in latent variable models. Ruslan Salakhutdinov Sam

Roweis, Sam

127

11 SOME PROPERTIES OF A NEW CONJUGATE GRADIENT METHOD  

E-Print Network [OSTI]

11 SOME PROPERTIES OF A NEW CONJUGATE GRADIENT METHOD Y. H. Dai and Y. Yuan State Key Laboratory@cc.ac.cn Abstract: It is proved that the new conjugate gradient method proposed by Dai and Yuan 5] produces problem minf(x) x 2 Rn (1.1) where f is smooth and its gradient g is available. Conjugate gradient methods

Yuan, Ya-xiang

128

Relationship between gradient and EM steps in latent variable models.  

E-Print Network [OSTI]

includes random search, standard gradient-based algorithms, line search methods such as conjugate gradient to to first order method operat- ing on the gradient of a locally reshaped likelihood function. DirectRelationship between gradient and EM steps in latent variable models. Ruslan Salakhutdinov Sam

Roweis, Sam

129

Electron transport and frozen concentration gradients in a mixed valent viologen molten salt  

SciTech Connect (OSTI)

This paper shows that electrolytically generated crossed concentration gradients of viologen (2+) and viologen (1+) in films of its mixed valent molten salt on interdigitated array electrodes can be thermally and stably frozen in place in the interelectrode gaps. A study is presented of properties of the gradient-containing films, as compared to films that are non-mixed valent (V{sup 2+}) or that are mixed valent but lack concentration gradients. Comparisons of charge transport measurements show that the 2-5 {mu}m wide concentration gradients are persistent in the molten salt at lowered temperatures, where ionic motions are quenched relative to electron hopping as shown by differences in conductivity between mixed valent and non-mixed valent films as the temperature is lowered from +50 to -70{degree}C. Differences in the magnitude and shape of high-field current-voltage curves taken from mixed valent nongradient and V{sup 2+}/V{sup +} gradient-containing samples are interpreted with an electron-hopping model that includes a parameter for kinetic dispersity. Differences between the capacitance of the mixed valent and non-mixed valent phase of the viologen molten salt are consistent with the formation of an electronic space charge at the metal/redox conductor interface. 18 refs., 8 figs., 1 tab.

Terrill, R.H.; Hatazawa, Tsuyonobu; Murray, R.W. [Univ. of North Carolina, Chapel Hill, NC (United States)

1995-11-09T23:59:59.000Z

130

Conjugate gradient algorithms using multiple recursions  

SciTech Connect (OSTI)

Much is already known about when a conjugate gradient method can be implemented with short recursions for the direction vectors. The work done in 1984 by Faber and Manteuffel gave necessary and sufficient conditions on the iteration matrix A, in order for a conjugate gradient method to be implemented with a single recursion of a certain form. However, this form does not take into account all possible recursions. This became evident when Jagels and Reichel used an algorithm of Gragg for unitary matrices to demonstrate that the class of matrices for which a practical conjugate gradient algorithm exists can be extended to include unitary and shifted unitary matrices. The implementation uses short double recursions for the direction vectors. This motivates the study of multiple recursion algorithms.

Barth, T.; Manteuffel, T.

1996-12-31T23:59:59.000Z

131

17 GHz High Gradient Accelerator Research  

SciTech Connect (OSTI)

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.

Temkin, Richard J. [MIT] [MIT; Shapiro, Michael A. [MIT] [MIT

2013-07-10T23:59:59.000Z

132

High-pressure liquid chromatographic gradient mixer  

DOE Patents [OSTI]

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.

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

1982-09-08T23:59:59.000Z

133

Universal Microfluidic Gradient Generator Daniel Irimia1  

E-Print Network [OSTI]

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

Geba, Dan-Andrei

134

Fourier Accelerated Conjugate Gradient Lattice Gauge Fixing  

E-Print Network [OSTI]

We provide details of the first implementation of a non-linear conjugate gradient method for Landau and Coulomb gauge fixing with Fourier acceleration. We find clear improvement over the Fourier accelerated steepest descent method, with the average time taken for the algorithm to converge to a fixed, high accuracy, being reduced by a factor of 2 to 4.

R. J. Hudspith

2014-05-22T23:59:59.000Z

135

Multi-gradient drilling method and system  

DOE Patents [OSTI]

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.

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

2003-01-01T23:59:59.000Z

136

Joining of Tungsten Armor Using Functional Gradients  

SciTech Connect (OSTI)

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.

John Scott O'Dell

2006-12-31T23:59:59.000Z

137

Photopolymerization in Microfluidic Gradient Generators: Microscale  

E-Print Network [OSTI]

-compliance profiles that are tunable on the micro- scale. The most straightforward way to create substrates with vari through the development of microfluidic networks,[7,8] with which one can easily generate solution (e microscale gradients with microfluidic networks, and a recent study that demon- strated

138

Gradient zone-boundary control in salt-gradient solar ponds  

DOE Patents [OSTI]

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.

Hull, J.R.

1982-09-29T23:59:59.000Z

139

A linear helicon plasma device with controllable magnetic field gradient  

SciTech Connect (OSTI)

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.

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

2012-06-15T23:59:59.000Z

140

Automated apparatus for producing gradient gels  

DOE Patents [OSTI]

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.

Anderson, Norman L. (Clarendon Hills, IL)

1986-01-01T23:59:59.000Z

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


141

Exploration of very high gradient cavities  

SciTech Connect (OSTI)

Several of the 9-cell ILC cavities processed at Jlab within ongoing ILC R&D program have shown interesting behavior at high fields, such as mode mixing and sudden field emission turn-on during quench. Equipped with thermometry and oscillating superleak transducer (OST) system for quench detection, we couple our RF measurements with local dissipation measurements. In this contribution we report on our findings with high gradient SRF cavities.

Grigory Eremeev

2011-07-01T23:59:59.000Z

142

Fast quantum algorithm for numerical gradient estimation  

E-Print Network [OSTI]

Given a blackbox for f, a smooth real scalar function of d real variables, one wants to estimate the gradient of f at a given point with n bits of precision. On a classical computer this requires a minimum of d+1 blackbox queries, whereas on a quantum computer it requires only one query regardless of d. The number of bits of precision to which f must be evaluated matches the classical requirement in the limit of large n.

Stephen P. Jordan

2005-01-02T23:59:59.000Z

143

Energy Gradient Theory of Hydrodynamic Instability  

E-Print Network [OSTI]

A new universal theory for flow instability and turbulent transition is proposed in this study. Flow instability and turbulence transition have been challenging subjects for fluid dynamics for a century. The critical condition of turbulent transition from theory and experiments differs largely from each other for Poiseuille flows. In this paper, a new mechanism of flow instability and turbulence transition is presented for parallel shear flows and the energy gradient theory of hydrodynamic instability is proposed. It is stated that the total energy gradient in the transverse direction and that in the streamwise direction of the main flow dominate the disturbance amplification or decay. A new dimensionless parameter K for characterizing flow instability is proposed for wall bounded shear flows, which is expressed as the ratio of the energy gradients in the two directions. It is thought that flow instability should first occur at the position of Kmax which may be the most dangerous position. This speculation is confirmed by Nishioka et al's experimental data. Comparison with experimental data for plane Poiseuille flow and pipe Poiseuille flow indicates that the proposed idea is really valid. It is found that the turbulence transition takes place at a critical value of Kmax of about 385 for both plane Poiseuille flow and pipe Poiseuille flow, below which no turbulence will occur regardless the disturbance. More studies show that the theory is also valid for plane Couette flows and Taylor-Couette flows between concentric rotating cylinders.

Hua-Shu Dou

2005-01-28T23:59:59.000Z

144

A Preconditioner for a Primal-Dual Newton Conjugate Gradients ...  

E-Print Network [OSTI]

Dec 30, 2014 ... A Preconditioner for a Primal-Dual Newton Conjugate Gradients Method for Compressed Sensing Problems.

Kimon Fountoulakis

2014-12-30T23:59:59.000Z

145

Optimization Online - Conjugate gradient methods based on secant ...  

E-Print Network [OSTI]

Sep 28, 2011 ... Conjugate gradient methods based on secant conditions that generate descent search directions for unconstrained optimization.

Y Narushima

2011-09-28T23:59:59.000Z

146

A three-term conjugate gradient method with sufficient descent ...  

E-Print Network [OSTI]

Finally, some numerical results of the proposed method are given. keyword; Unconstrained optimization, three-term conjugate gradient method, sufficient.

2009-11-02T23:59:59.000Z

147

AN EXTENDED CLASS OF NONLINEAR CONJUGATE GRADIENT METHODS \\Lambda  

E-Print Network [OSTI]

AN EXTENDED CLASS OF NONLINEAR CONJUGATE GRADIENT METHODS \\Lambda Y. H. Dai and Y. Yuan State Key 100080, P. R. China. Email: dyh,yyx@lsec.cc.ac.cn Abstract Conjugate gradient methods are very important be analyzed uniformly, conjugate gradient methods are often analyzed individually. Recently, Dai and Yuan

Yuan, Ya-xiang

148

AN AUGMENTED CONJUGATE GRADIENT METHOD FOR SOLVING CONSECUTIVE  

E-Print Network [OSTI]

AN AUGMENTED CONJUGATE GRADIENT METHOD FOR SOLVING CONSECUTIVE SYMMETRIC POSITIVE DEFINITE LINEAR definite matrix A. The conjugate gradient method applied to the first system generates a Krylov subspace conjugate gradient method is then applied with a specific initial guess and initial descent direction

Paris-Sud XI, Université de

149

CONVERGENCE PROPERTIES OF NONLINEAR CONJUGATE GRADIENT METHODS1  

E-Print Network [OSTI]

CONVERGENCE PROPERTIES OF NONLINEAR CONJUGATE GRADIENT METHODS1 Yuhong Dai2 , Jiye Han3 , Guanghui contributions on convergence studies of conjugate gradient methods have been made by Gilbert and Nocedal [6 for ensuring the global convergence of conjugate gradient methods. This paper shows that the sufficient descent

Yuan, Ya-xiang

150

ON THE CONNECTION BETWEEN THE CONJUGATE GRADIENT METHOD AND  

E-Print Network [OSTI]

ON THE CONNECTION BETWEEN THE CONJUGATE GRADIENT METHOD AND QUASI-NEWTON METHODS ON QUADRATIC Royal Institute of Technology February 2013 Abstract It is well known that the conjugate gradient method gradient method. In the framework based on a sufficient condition to obtain mutually conjugate search

Forsgren, Anders

151

Preconditioned Conjugate Gradient Methods for Three Dimensional Linear Elasticity  

E-Print Network [OSTI]

Preconditioned Conjugate Gradient Methods for Three Dimensional Linear Elasticity by John Kenneth. A brief review is also made of stopping criteria for conjugate gradient solvers. One method based and tested with poor results. iv #12;Contents 1 Introduction 1 1.1 Preconditioned Conjugate Gradient Methods

Waterloo, University of

152

CG DESCENT, A CONJUGATE GRADIENT METHOD WITH GUARANTEED DESCENT  

E-Print Network [OSTI]

CG DESCENT, A CONJUGATE GRADIENT METHOD WITH GUARANTEED DESCENT #3; WILLIAM W. HAGER y AND HONGCHAO are given. Key words. Conjugate gradient method, unconstrained optimization, convergence, line search, Wolfe nonlinear conjugate gradient method for solving an unconstrained optimization problem min ff(x) : x 2

Zhang, Hongchao

153

Exploiting Matrix Symmetry to Improve FPGA-Accelerated Conjugate Gradient  

E-Print Network [OSTI]

the Conjugate Gradient (CG) method using an FPGA co-processor. As in previous approaches, our coExploiting Matrix Symmetry to Improve FPGA- Accelerated Conjugate Gradient Jason D. Bakos, Krishna, high- performance computing, sparse matrix vector multiply, conjugate gradient I. INTRODUCTION Linear

Bakos, Jason D.

154

A conjugate gradient learning algorithm for recurrent neural networks  

E-Print Network [OSTI]

]. In particular, the conjugate gradient method is commonly used in training BP networks due to its speed1 A conjugate gradient learning algorithm for recurrent neural networks (Revised Version) Wing algorithm by incorporating conjugate gradient computation into its learning procedure. The resulting

Mak, Man-Wai

155

APPROXIMATE INVERSE PRECONDITIONING FOR THE CONJUGATE GRADIENT METHOD  

E-Print Network [OSTI]

APPROXIMATE INVERSE PRECONDITIONING FOR THE CONJUGATE GRADIENT METHOD ON A VECTOR COMPUTER Michele definite matrix, by the preconditioned conjugate gradient method (PCG) (see, e.g., [4]). It is well of the conjugate gradient method reduces to computing a matrix­ vector product with G, an operation which offers

Tůma, Miroslav

156

Gradient-based Methods for Production Optimization of Oil Reservoirs  

E-Print Network [OSTI]

Gradient-based Methods for Production Optimization of Oil Reservoirs Eka Suwartadi Doctoral Thesis oil reservoirs. Gradient- based optimization, which utilizes adjoint-based gradient computation optimization for water flooding in the secondary phase of oil recovery is the main topic in this thesis

Foss, Bjarne A.

157

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

SciTech Connect (OSTI)

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.

Mahdavi, M., E-mail: m.mahdavi@umz.ac.ir [Physics Department, University of Mazandaran, P.O. Box 47415-416, Babolsar (Iran, Islamic Republic of); Khodadadi Azadboni, F., E-mail: f.khodadadi@stu.umz.ac.ir [Physics Department, University of Mazandaran, P.O. Box 47415-416, Babolsar (Iran, Islamic Republic of); Young Researchers Club, Sari Branch, Islamic Azad University, P.O. Box 48161-194, Sari (Iran, Islamic Republic of)

2014-02-15T23:59:59.000Z

158

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

E-Print Network [OSTI]

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 $\

Codina Cotar; Jean-Dominique Deuschel; Stefan Müller

2008-01-08T23:59:59.000Z

159

Gradient Navigation Model for Pedestrian Dynamics  

E-Print Network [OSTI]

We present a new microscopic ODE-based model for pedestrian dynamics: the Gradient Navigation Model. The model uses a superposition of gradients of distance functions to directly change the direction of the velocity vector. The velocity is then integrated to obtain the location. The approach differs fundamentally from force based models needing only three equations to derive the ODE system, as opposed to four in, e.g., the Social Force Model. Also, as a result, pedestrians are no longer subject to inertia. Several other advantages ensue: Model induced oscillations are avoided completely since no actual forces are present. The derivatives in the equations of motion are smooth and therefore allow the use of fast and accurate high order numerical integrators. At the same time, existence and uniqueness of the solution to the ODE system follow almost directly from the smoothness properties. In addition, we introduce a method to calibrate parameters by theoretical arguments based on empirically validated assumptions rather than by numerical tests. These parameters, combined with the accurate integration, yield simulation results with no collisions of pedestrians. Several empirically observed system phenomena emerge without the need to recalibrate the parameter set for each scenario: obstacle avoidance, lane formation, stop-and-go waves and congestion at bottlenecks. The density evolution in the latter is shown to be quantitatively close to controlled experiments. Likewise, we observe a dependence of the crowd velocity on the local density that compares well with benchmark fundamental diagrams.

Felix Dietrich; Gerta Köster

2014-05-14T23:59:59.000Z

160

Preparation and characterization of gradient polymer films  

SciTech Connect (OSTI)

Gradient polymers are multicomponent polymers whose chemical constitution varies with depth in the sample. Although these polymers may possess unique mechanical, optical, and barrier properties they remain relatively unexplored. This work is a study of the preparation of gradient polymers by sequential exposure of films to a diffusing monomer followed by electron beam irradiation. Initial experiments involved immersion of poly(vinyl chloride) (PVC) films in styrene or n-butyl methacrylate (BMA) for various time periods followed by irradiation with 1 or 10 megarads of accelerated electrons. A significant amount of poly(n-butyl methacrylate) (PBMA) formed in PVC/BMA systems, but little polystyrene could be found in the PVC/styrene films. A second set of experiments involved immersion of PVC and polyethylene (PE) films in BMA for 20, 40, 60, and 720 minutes followed by irradiation with 10 megarads of electrons. These films were then characterized using optical microscopy, quantitative transmission Fourier transform infrared spectroscopy (FTIR), and a depth profiling procedure based on quantitative attenuated total reflection (ATR) FTIR. It was concluded that the mechanism of PBMA formation in the polyethylene films was a result of events immediately following irradiation. Atmospheric oxygen diffusing into irradiated films trapped free radicals at the film surfaces. This was followed by storage in an evacuated desiccator where unintentional exposure to BMA vapor took place. This BMA reacted with free radicals that remained within the film cores, polymerizing to PBMA.

Smith, S.C.

1987-01-01T23:59:59.000Z

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


161

Analysis of Bacterial Communities in Seagrass Bed Sediments by Double-Gradient Denaturing Gradient Gel Electrophoresis  

E-Print Network [OSTI]

Microbial Ecology Analysis of Bacterial Communities in Seagrass Bed Sediments by Double, including the presence or absence of vegetation, depth into sediment, and season. Double- gradient of these similarity coefficients were used to group banding patterns by depth into sediment, presence or absence

Sherman, Tim

162

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

DOE Patents [OSTI]

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.

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

2000-01-01T23:59:59.000Z

163

Improving DWF Simulations: the Force Gradient Integrator and the Möbius Accelerated DWF Solver  

E-Print Network [OSTI]

We have implemented a variant of the force gradient integrator proposed by Kennedy et.al. and are using it in our production 2+1 flavor DWF simulations with pion masses of 180 MeV in (4.5fm)3 volumes. We find modest speed-ups (\\sim 20%) from using the force gradient integrator, compared to our previously used Omelyan integrator. On other ensembles, primarily finite temperature 2+1 flavor DWF QCD, we have extensively tuned the Hasenbusch preconditioning masses and achieved speed-ups of 2-3x. Here we have also switched to the force gradient integrator, but this change has not had any impact on the speed. We also report on an improved solver for DWF, which uses M\\"obius fermions, with a smaller fifth dimension than the original DWF fermions, as an intermediate step in the generation of solutions of the Dirac equation. This approach cuts the number of effective Dirac applications by approximately a factor of 2 when the conjugate gradient iteration count is large.

Hantao Yin; Robert D. Mawhinney

2011-11-21T23:59:59.000Z

164

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

SciTech Connect (OSTI)

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.

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)

2013-12-16T23:59:59.000Z

165

Constant field gradient planar coupled cavity structure  

DOE Patents [OSTI]

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.

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

1999-07-27T23:59:59.000Z

166

High gradient lens for charged particle beam  

DOE Patents [OSTI]

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.

Chen, Yu-Jiuan

2014-04-29T23:59:59.000Z

167

High-gradient compact linear accelerator  

DOE Patents [OSTI]

A high-gradient linear accelerator comprises a solid-state stack in a vacuum of five sets of disc-shaped Blumlein modules each having a center hole through which particles are sequentially accelerated. Each Blumlein module is a sandwich of two outer conductive plates that bracket an inner conductive plate positioned between two dielectric plates with different thicknesses and dielectric constants. A third dielectric core in the shape of a hollow cylinder forms a casing down the series of center holes, and it has a dielectric constant different that the two dielectric plates that sandwich the inner conductive plate. In operation, all the inner conductive plates are charged to the same DC potential relative to the outer conductive plates. Next, all the inner conductive plates are simultaneously shorted to the outer conductive plates at the outer diameters. The signal short will propagate to the inner diameters at two different rates in each Blumlein module. A faster wave propagates quicker to the third dielectric core across the dielectric plates with the closer spacing and lower dielectric constant. When the faster wave reaches the inner extents of the outer and inner conductive plates, it reflects back outward and reverses the field in that segment of the dielectric core. All the field segments in the dielectric core are then in unipolar agreement until the slower wave finally propagates to the third dielectric core across the dielectric plates with the wider spacing and higher dielectric constant. During such unipolar agreement, particles in the core are accelerated with gradients that exceed twenty megavolts per meter.

Carder, Bruce M. (205 Rogue River Hwy., Gold Hill, OR 97525)

1998-01-01T23:59:59.000Z

168

High-gradient compact linear accelerator  

DOE Patents [OSTI]

A high-gradient linear accelerator comprises a solid-state stack in a vacuum of five sets of disc-shaped Blumlein modules each having a center hole through which particles are sequentially accelerated. Each Blumlein module is a sandwich of two outer conductive plates that bracket an inner conductive plate positioned between two dielectric plates with different thicknesses and dielectric constants. A third dielectric core in the shape of a hollow cylinder forms a casing down the series of center holes, and it has a dielectric constant different that the two dielectric plates that sandwich the inner conductive plate. In operation, all the inner conductive plates are charged to the same DC potential relative to the outer conductive plates. Next, all the inner conductive plates are simultaneously shorted to the outer conductive plates at the outer diameters. The signal short will propagate to the inner diameters at two different rates in each Blumlein module. A faster wave propagates quicker to the third dielectric core across the dielectric plates with the closer spacing and lower dielectric constant. When the faster wave reaches the inner extents of the outer and inner conductive plates, it reflects back outward and reverses the field in that segment of the dielectric core. All the field segments in the dielectric core are then in unipolar agreement until the slower wave finally propagates to the third dielectric core across the dielectric plates with the wider spacing and higher dielectric constant. During such unipolar agreement, particles in the core are accelerated with gradients that exceed twenty megavolts per meter. 10 figs.

Carder, B.M.

1998-05-26T23:59:59.000Z

169

Pressure &Pressure & TemperatureTemperature  

E-Print Network [OSTI]

to measure atmospheric pressure, and thermometer toprobe to measure atmospheric pressure, and thermometer toprobe to measure atmospheric pressure, and thermometer toprobe to measure atmospheric pressure, and thermometer to measure air temperature.measure air temperature.measure air temperature.measure air temperature

California at Santa Cruz, University of

170

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

E-Print Network [OSTI]

scaled memoryless BFGS method and propose a family of conjugate gradient methods for unconstrained optimization. An improved Wolfe line search is also ...

2011-06-15T23:59:59.000Z

171

Optimization Online - A three-term conjugate gradient method with ...  

E-Print Network [OSTI]

Dec 3, 2009 ... A three-term conjugate gradient method with sufficient descent property for unconstrained optimization. Y Narushima(narusima ***at*** ...

Y Narushima

2009-12-03T23:59:59.000Z

172

Optimization Online - Linearizing the Method of Conjugate Gradients  

E-Print Network [OSTI]

Sep 9, 2012 ... Abstract: The method of conjugate gradients (CG) is widely used for the iterative solution of large sparse systems of equations $Ax=b$, where ...

Serge Gratton

2012-09-09T23:59:59.000Z

173

A Perry Descent Conjugate Gradient Method with Restricted Spectrum  

E-Print Network [OSTI]

Mar 7, 2011 ... Abstract: A new nonlinear conjugate gradient method, based on Perry's idea, is presented. And it is shown that its sufficient descent property is ...

Dongyi Liu

2011-03-07T23:59:59.000Z

174

On the connection between the conjugate gradient method and ...  

E-Print Network [OSTI]

Feb 9, 2013 ... Abstract: It is well known that the conjugate gradient method and a quasi-Newton method, using any well-defined update matrix from the ...

Anders Forsgren

2013-02-09T23:59:59.000Z

175

Concentration Gradient and Information Energy for Decentralized UAV Control1  

E-Print Network [OSTI]

spills, industrial release accidents, or chemical/biological/nuclear terrorist attacks. DependingConcentration Gradient and Information Energy for Decentralized UAV Control1 William J. Pisano2

Mohseni, Kamran

176

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

Open Energy Info (EERE)

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

177

alpine elevation gradient: Topics by E-print Network  

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

Niche expansion leads to small-scale adaptive divergence along an elevation gradient in a medium of the Environment, University of California, Los Angeles, CA 90095, USA Niche...

178

Photo of the Week: The Alternating Gradient Synchrotron | Department...  

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

Gradient Synchrotron (AGS) has been one of the world's premiere particle accelerators, well known for the

179

Spatiotemporal Gradient Modeling with Applications Harrison S. Quick1  

E-Print Network [OSTI]

, and geospatial information storage, analysis, and distribution systems have led to a burgeoning of spatial 2.3 Gradient analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2.5 Data analysis

Carlin, Bradley P.

180

A Sparsity Preserving Stochastic Gradient Method for Composite ...  

E-Print Network [OSTI]

Apr 23, 2011 ... Abstract: We propose new stochastic gradient algorithms for solving convex composite optimization problems. In each iteration, our algorithms ...

Qihang Lin

2011-04-23T23:59:59.000Z

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


181

A Sparsity Preserving Stochastic Gradient Method for Composite ...  

E-Print Network [OSTI]

Apr 23, 2011 ... We propose new stochastic gradient algorithms for solving convex composite optimization problems. In each iteration, our algorithms utilize a ...

2011-04-23T23:59:59.000Z

182

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

Open Energy Info (EERE)

Gradient Holes At Long Valley Caldera Geothermal Area (Conservation, 2009) Exploration Activity Details Location Long Valley Caldera Geothermal Area Exploration Technique Thermal...

183

second-order convex splitting schemes for gradient flows with ...  

E-Print Network [OSTI]

Abstract. We construct unconditionally stable, unconditionally uniquely solvable, and second-order accurate (in time) schemes for gradient flows with energy of ...

2011-11-08T23:59:59.000Z

184

Existence and uniqueness of global classical solutions of a gradient ...  

E-Print Network [OSTI]

This gradient flow is generated by the Laudau-de Gennes energy functional that ... feature of this evolution problem is that it is generated by an energy functional ...

2015-01-22T23:59:59.000Z

185

An accelerated proximal gradient algorithm for nuclear norm ...  

E-Print Network [OSTI]

Mar 27, 2009 ... An accelerated proximal gradient algorithm for nuclear norm regularized least squares problems. Kim-Chuan Toh (mattohkc ***at*** nus.edu.sg)

Kim-Chuan Toh

2009-03-27T23:59:59.000Z

186

Gradient methods for convex minimization: better rates under ...  

E-Print Network [OSTI]

Mar 20, 2013 ... Gradient methods for convex minimization: better rates under weaker conditions. Hui Zhang(hhuuii.zhang ***at*** gmail.com)

Hui Zhang

2013-03-20T23:59:59.000Z

187

Thermal Gradient Holes At Lake City Hot Springs Area (Warpinski...  

Open Energy Info (EERE)

Warpinski, Et Al., 2004) Exploration Activity Details Location Lake City Hot Springs Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness not indicated...

188

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

Open Energy Info (EERE)

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

189

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

Open Energy Info (EERE)

Blue Mountain Geothermal Area (Fairbank & Niggemann, 2004) Exploration Activity Details Location Blue Mountain Geothermal Area Exploration Technique Thermal Gradient Holes Activity...

190

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

Open Energy Info (EERE)

Activity Details Location Long Valley Caldera Geothermal Area Exploration Technique Thermal Gradient Holes Activity Date 1978 - 1985 Usefulness useful DOE-funding Unknown...

191

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

Open Energy Info (EERE)

holes Additional References Retrieved from "http:en.openei.orgwindex.php?titleThermalGradientHolesAtWaunitaHotSpringsGeothermalArea(Zacharakis,1981)&oldid762...

192

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...

193

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

Open Energy Info (EERE)

Thermal Gradient Holes At Lightning Dock Geothermal Area (Cunniff & Bowers, 2005) Exploration Activity Details Location Lightning Dock Geothermal Area Exploration Technique Thermal...

194

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

Open Energy Info (EERE)

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

195

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

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At North Brawley Geothermal Area (Matlick & Jayne, 2008) Exploration...

196

Exploration geothermal gradient drilling, Platanares, Honduras, Central America  

SciTech Connect (OSTI)

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.

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

1988-01-01T23:59:59.000Z

197

Measurement of laser heating in spin exchange optical pumping by NMR diffusion sensitization gradients  

SciTech Connect (OSTI)

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.

Parnell, Steven R.; Deppe, Martin H.; Ajraoui, Salma; Parra-Robles, Juan; Wild, Jim M. [Unit of Academic Radiology, University of Sheffield, Royal Hallamshire Hospital, Glossop Road, Sheffield, S10 2JF (United Kingdom); Boag, Stephen [ISIS, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX (United Kingdom)

2010-05-15T23:59:59.000Z

198

Combining Conjugate Direction Methods with Stochastic Approximation of Gradients  

E-Print Network [OSTI]

Combining Conjugate Direction Methods with Stochastic Approximation of Gradients #3; Nicol N-8092 Zurich, Switzerland http://www.icos.ethz.ch/ Abstract The method of conjugate directions provides from conjugate gra- dient in the stochastic (online) setting, us- ing fast Hessian-gradient products

Schraudolph, Nicol N.

199

Combining Conjugate Direction Methods with Stochastic Approximation of Gradients  

E-Print Network [OSTI]

Combining Conjugate Direction Methods with Stochastic Approximation of Gradients Nicol N-8092 Z¨urich, Switzerland http://www.icos.ethz.ch/ Abstract The method of conjugate directions provides conjugate gra- dient in the stochastic (online) setting, us- ing fast Hessian-gradient products to set up

Schraudolph, Nicol N.

200

Evaluation of liquid lift approach to dual gradient  

E-Print Network [OSTI]

the mudline to the rig floor so as to maintain the bottom hole pressure. Several methods have been developed to achieve the dual gradient drilling principle. For this research project, we paid more attention to the liquid lift, dual gradient drilling (riser...

Okafor, Ugochukwu Nnamdi

2009-05-15T23:59:59.000Z

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


201

Evaluation of liquid lift approach to dual gradient drilling  

E-Print Network [OSTI]

the mudline to the rig floor so as to maintain the bottom hole pressure. Several methods have been developed to achieve the dual gradient drilling principle. For this research project, we paid more attention to the liquid lift, dual gradient drilling (riser...

Okafor, Ugochukwu Nnamdi

2008-10-10T23:59:59.000Z

202

SampleRank: Training Factor Graphs with Atomic Gradients  

E-Print Network [OSTI]

a user-provided loss function to distribute stochastic gradients across an MCMC chain. As a result, parameter updates can be computed between arbitrary MCMC states. Sam- pleRank is not only faster than CD- expensive gradients between the ground-truth and samples along an MCMC chain yielding a stochastic

McCallum, Andrew

203

Generalized Hooke's law for isotropic second gradient materials  

E-Print Network [OSTI]

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.

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

2010-08-17T23:59:59.000Z

204

Natural Conjugate Gradient on Complex Flag Manifolds for Complex Independent Subspace  

E-Print Network [OSTI]

conjugate gradient method yields better convergence compared to the natural gradient geodesic search method is the natural gradient geodesic search method (NGS), and the other is the natural conjugate gradient method (NCG the natural gradient or the Newton's method on complex manifolds, however, the behavior of the conjugate

Plumbley, Mark

205

A conjugate Rosen's gradient projection method with global line search for piecewise linear optimization  

E-Print Network [OSTI]

A conjugate Rosen's gradient projection method with global line search for piecewise linear cutting plane method, simplex method, Rosen's gradient projection, conjugate gradient. 1 Introduction the zig-zagging of the gradient projection, we propose a conjugate gradient version of the face simplex

Beltran-Royo, Cesar

206

Efficient and robust gradient enhanced Kriging emulators.  

SciTech Connect (OSTI)

%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.

Dalbey, Keith R.

2013-08-01T23:59:59.000Z

207

Algorithm PREQN: Fortran 77 Subroutines for Preconditioning the Conjugate Gradient Method  

E-Print Network [OSTI]

Algorithm PREQN: Fortran 77 Subroutines for Preconditioning the Conjugate Gradient Method Jos subroutines for automatically generating pre­ conditioners for the conjugate gradient method. It is designed. Additional Key Words and Phrases: Preconditioning, conjugate gradient method, quasi­ Newton method, Hessian

Nocedal, Jorge

208

COMPARISON OF THE DEFLATED PRECONDITIONED CONJUGATE GRADIENT METHOD AND ALGEBRAIC MULTIGRID FOR COMPOSITE  

E-Print Network [OSTI]

COMPARISON OF THE DEFLATED PRECONDITIONED CONJUGATE GRADIENT METHOD AND ALGEBRAIC MULTIGRID algorithms such as the Preconditioned Conjugate Gradient (PCG) method. This paper considers the Deflated Preconditioned Conjugate Gradient (DPCG) method in which the rigid body modes of sets of elements

MacLachlan, Scott

209

Optimization Online - A conjugate-gradient based approach for ...  

E-Print Network [OSTI]

Feb 29, 2008 ... In particular, it is noted that with a bound on the two-norm of the columns, the method is equivalent to the conjugate-gradient method. Further ...

Fredrik Carlsson

2008-02-29T23:59:59.000Z

210

on the connection between the conjugate gradient method and ...  

E-Print Network [OSTI]

It is well known that the conjugate gradient method and a quasi-Newton method, using any well-defined update matrix from the one-parameter Broy- den family ...

2013-02-07T23:59:59.000Z

211

Potential use of hollow spheres in dual gradient drilling  

E-Print Network [OSTI]

The increasing number of significant deepwater discoveries has pushed the operator and service oil companies to focus their efforts on developing new technologies to drill in deeper water. Dual gradient drilling (DGD) will allow reaching deeper...

Vera Vera, Liliana

2002-01-01T23:59:59.000Z

212

Function of the anterior gradient protein family in cancer   

E-Print Network [OSTI]

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...

Fourtouna, Argyro

2009-01-01T23:59:59.000Z

213

Microsoft PowerPoint - High Gradient Inverse Free Electron Laser...  

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

Hi h G di t Hi h i High Gradient High energy gain Inverse Free Electron Laser at BNL P. Musumeci UCLA Department of Physics and Astronomy ATF user meeting April 2-3 2009 Outline...

214

alternating gradient synchrotron: Topics by E-print Network  

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

sources also have the advantage of a time structure with a high peak neutron flux. The basic requirement is for a... Bryant, P J 1995-01-01 36 Gradient House. Open...

215

CONSERVATION ECOLOGY -ORIGINAL RESEARCH Conservation through connectivity: can isotopic gradients  

E-Print Network [OSTI]

CONSERVATION ECOLOGY - ORIGINAL RESEARCH Conservation through connectivity: can isotopic gradients Abstract Conservation of migratory wildlife requires knowledge of migratory connectivity between breeding conservation efforts for endangered migratory species (Webster et al. 2002; Rubenstein and Hobson 2004; Webster

Richner, Heinz

216

A parametric study of thermomechanical behavior of functionally gradient materials  

E-Print Network [OSTI]

(FSDT) that accounts for the transverse shear strains and the rotations, coupled with a three dimensional heat conduction equation is formulated for a functionally gradient plate. Both problems are studied by varying the volume fraction of a ceramic...

Chin, Che-Doong

1996-01-01T23:59:59.000Z

217

Computational Inversion of Electron Tomography Images -Gradient Flows  

E-Print Network [OSTI]

Computational Inversion of Electron Tomography Images Using L2 -Gradient Flows Guoliang Xu 1) Ming Computing Institute of Computational Mathematics, Academy of Mathematics and System Sciences, Chinese Academy of Sciences, Beijing 100190, China 2) Department of Computer Sciences and Institute

Texas at Austin, University of

218

Thermal Gradient Holes At Lightning Dock Geothermal Area (Arnold...  

Open Energy Info (EERE)

DOE-funding Unknown Exploration Basis Known shallow hot spot in Animas Valley Notes Four thermal gradient holes were authorized to be drilled by AMEX, but no results were...

219

Generation of Gradients Having Complex Shapes Using Microfluidic Networks  

E-Print Network [OSTI]

Generation of Gradients Having Complex Shapes Using Microfluidic Networks Stephan K. W. Dertinger, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138 This paper describes the generation each carrying different concentrations of substances laminarly and side-by-side generated step

Prentiss, Mara

220

A Spectral Conjugate Gradient Method for Unconstrained Optimization  

SciTech Connect (OSTI)

A family of scaled conjugate gradient algorithms for large-scale unconstrained minimization is defined. The Perry, the Polak-Ribiere and the Fletcher-Reeves formulae are compared using a spectral scaling derived from Raydan's spectral gradient optimization method. The best combination of formula, scaling and initial choice of step-length is compared against well known algorithms using a classical set of problems. An additional comparison involving an ill-conditioned estimation problem in Optics is presented.

Birgin, E. G. [Department of Computer Science, IME-USP, University of Sao Paulo, Rua do Matao, 1010 - Cidade Universitaria, 05508-900 Sao Paulo SP (Brazil)], E-mail: egbirgin@ime.usp.br; Martinez, J. M. [Department of Applied Mathematics, IMECC-UNICAMP, University of Campinas, CP 6065, 13081-970 Campinas SP (Brazil)], E-mail: martinez@ime.unicamp.br

2001-07-01T23:59:59.000Z

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


221

Osteochondral Interface Tissue Engineering using Macroscopic Gradients of Physicochemical Signals  

E-Print Network [OSTI]

of tissue interfaces. Yet, just because tissues are separated from one another by type, function, location, or anatomical prevalence, does not necessarily mean that the interfaces are as easily distinguishable, as the interfaces themselves are highly complex... not yield a “true” continuous gradient, it can have many discrete advantages over continuous gradients. Because of the inherent discontinuous fabrication methods (developing sections separately and fusing together), however, design effort must be placed...

Dormer, Nathan Henry

2011-04-25T23:59:59.000Z

222

E-Print Network 3.0 - alternating gradient focusing Sample Search...  

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

gradient focusing Page: << < 1 2 3 4 5 > >> 1 Gradient Estimation in Global Optimization Algorithms Megan Hazen, Member, IEEE and Maya R. Gupta, Member, IEEE Summary:...

223

E-Print Network 3.0 - advanced gradient based Sample Search Results  

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

Gradients of Poly(N-isopropylacrylamide) Polymer Brushes Prepared by Summary: , an electrochemical-potential-gradient- based method has been developed to generate chemical...

224

Mass Function Gradients and the Need for Dark Matter  

E-Print Network [OSTI]

There is substantial evidence that the initial mass function (IMF) may be a function of the local star formation conditions. In particular, the IMF is predicted to flatten with increasing local luminosity density, with the formation of massive stars being preferentially enhanced in brighter regions. If IMF gradients are general features of galaxies, several previous astrophysical measurements, such as the surface mass densities of spirals (obtained assuming constant mass to light ratios), were plagued by substantial systematic errors. In this Letter, calculations which account for possible IMF gradients are presented of surface densities of spiral galaxies. Compared to previous estimates, the mass densities corrected for IMF gradients are higher in the outer regions of the disks. For a model based on the Milky Way but with an IMF scaled according to R136, the rotation curve without the traditional dark halo component falls with Galactocentric radius, though slower than it would without IMF gradients. For a second model of the Milky Way in which the IMF gradient is increased by 50%, the rotation curve is approximately flat in the outer disk, with a rotational velocity below ~220 km/s only before the traditional dark halo component is added. These results, if generalizable to other galaxies, not only call into question the assertion that dark matter halos are compatible with the flat rotation curves of spiral galaxies, but also may clarify our understanding of a wide variety of other astrophysical phenomena such as the G-dwarf problem, metallicity gradients, and the Tully-Fisher relation.

Jason A. Taylor

1998-03-05T23:59:59.000Z

225

Use of Rapid Temperature Measurements at a 2-Meter Depth to Augment...  

Open Energy Info (EERE)

Measurements at a 2-Meter Depth to Augment Deeper Temperature Gradient Drilling Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Use of Rapid...

226

Method and apparatus for producing a carbon based foam article having a desired thermal-conductivity gradient  

DOE Patents [OSTI]

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.

Klett, James W. (Knoxville, TN) [Knoxville, TN; Cameron, Christopher Stan (Sanford, NC) [Sanford, NC

2010-03-02T23:59:59.000Z

227

Validation of electron temperature gradient turbulence in the Columbia Linear Machine  

E-Print Network [OSTI]

%, steady-state oscillations at $ 0:3 Ŕ 0:5 MHz (in the plasma frame), with azimuthal wave numbers m $ 14Ŕ16 cascade of the energy from the fastest growing high-m modes to low-m nonlinear oscillations, which voltage on the inner disk mesh r voltage on the outer ring mesh r1

Lin, Zhihong

228

A Microfluidic Device with a Linear Temperature Gradient for Parallel and Combinatorial Measurements  

E-Print Network [OSTI]

-dimensional grid such as a DNA chip or a multiwell plate. Variables such as buffer conditions, chemical composition on the simple solution to the Fourier heat diffusion equation16 when heat flow is restricted to one direction the direction of heat transfer, and k is the thermal conductivity of the medium in which the heat is flowing

229

Temperature gradient transport growth of potassium tantalate niobate, KTa??xNbxO?, single crystals  

E-Print Network [OSTI]

occurs was not found to vary linearly as reported in references [3, 17) instead the relationship is more parabolic in this region. One reason for this deviation could be the fact that the transition for concentrations x&. 3 are first order but below x... crystallinity, relative dielectric constant and Curie point. Results obtained confirm reported phase diagrams of this system but the relationship between composition and Curie point was found to be a parabolic function instead of a linear relationship...

Goeking, Kent Wayne

1987-01-01T23:59:59.000Z

230

Gravity compensation in dusty-plasmas by application of a temperature gradient  

E-Print Network [OSTI]

Micron sized particles can be suspended or even lifted up in gas by the thermophoretic effect. This has many applications in physics and technology.

Rothermel, H; Morfill, G E; Thomas, H

2001-01-01T23:59:59.000Z

231

Manipulation of Colloids by Nonequilibrium Depletion Force in Temperature Gradient Hong-Ren Jiang1  

E-Print Network [OSTI]

irrespective of their own thermophoretic properties. An amplification of the trapped colloid density's thermophoresis. These results show how to control thermophoretic properties of colloids. PACS numbers: 82.70.Dd

Sano, Masaki

232

Rate of decrease of the specific surface area of dry snow: Isothermal and temperature gradient conditions  

E-Print Network [OSTI]

crystals. These effects drive sublimation/condensation cycles that modify the sizes and shapes of snow through sublimation/condensation and adsorption/desorption cycles. Adsorbed gases can diffuse inside snow variations must be described in models of snow physics and chemistry [Flin et al., 2003; Legagneux and Domine

Domine, Florent

233

Temperature gradients are supported by cantori in chaotic fields S.R. Hudson  

E-Print Network [OSTI]

devil's staircase. [1] T. E. Evans, R. A. Moyer, P. R. Thomas, et al., Phys. Rev. Lett. 92, 235003 (2004

Hudson, Stuart

234

Non-axisymmetric wind-accretion simulations. II. Density gradients  

E-Print Network [OSTI]

The hydrodynamics of a variant of classical Bondi-Hoyle-Lyttleton accretion is investigated: a totally absorbing sphere moves at various Mach numbers (3 and 10) relative to a medium, which is taken to be an ideal gas having a density gradient (of 3%, 20% or 100% over one accretion radius) perpendicular to the relative motion. Similarly to the 3D models published previously, both with velocity gradients and without, the models with a density gradient presented here exhibit non-stationary flow patterns, although the Mach cone remains fairly stable. The accretion rates of mass, linear and angular momenta do not fluctuate as strongly as published previously for 2D models. No obvious trend of the dependency of mass accretion rate fluctuations on the density gradient can be discerned. The average specific angular momentum accreted is roughly between zero and 70% of the total angular momentum available in the accretion cylinder in the cases where the average is prograde. Due to the large fluctuations during accretion, the average angular momentum of some models is retrograde by up to 25%. Small gradients hardly influence the average accretion rates as compared to accretion from a homogeneous medium, while very large ones succeed to dominate and form an accretion flow in which the sense of rotation is not inverted.

M. Ruffert

1999-03-19T23:59:59.000Z

235

Evolutionary and Gradient-Based Algorithms for Lennard-Jones Cluster Optimization  

E-Print Network [OSTI]

gradient method, while Section 3 shows how the asynchronous conjugate gradient method compares and randomized gradient methods with respect to their global search behavior. The randomized gradient method.g., conjugate gra- dient method) is started. With the local minima in- formation, the search is continued

Schraudolph, Nicol N.

236

The Solution of Systems of Linear Equations using the Conjugate Gradient Method  

E-Print Network [OSTI]

The Solution of Systems of Linear Equations using the Conjugate Gradient Method on the Parallel gradient solver on the SPMD­programmable MUSIC­system. We outline the conjugate gradient method, give­associativity of the floating point addition. We investi­ gate the speed of convergence of the conjugate gradient method

Schneider, Jean-Guy

237

Newton-conjugate-gradient methods for solitary wave computations Jianke Yang  

E-Print Network [OSTI]

Newton-conjugate-gradient methods for solitary wave computations Jianke Yang Department's method Conjugate-gradient methods a b s t r a c t In this paper, the Newton-conjugate-gradient methods the linearization operator is self-adjoint, the preconditioned conjugate-gradient method is pro- posed to solve

Yang, Jianke

238

A NONLINEAR CONJUGATE GRADIENT METHOD WITH A STRONG GLOBAL CONVERGENCE PROPERTY  

E-Print Network [OSTI]

A NONLINEAR CONJUGATE GRADIENT METHOD WITH A STRONG GLOBAL CONVERGENCE PROPERTY Y. H. DAI AND Y­182 Abstract. Conjugate gradient methods are widely used for unconstrained optimization, especially large scale gradient methods. This paper presents a new version of the conjugate gradient method, which converges

Yuan, Ya-xiang

239

Algorithm 851: CG DESCENT, a Conjugate Gradient Method with Guaranteed Descent  

E-Print Network [OSTI]

Algorithm 851: CG DESCENT, a Conjugate Gradient Method with Guaranteed Descent WILLIAM W. HAGER In Hager and Zhang [2005] we introduce a new nonlinear conjugate gradient method for solving con- jugate gradient research. The iterates xk, k 0, in conjugate gradient methods satisfy

Zhang, Hongchao

240

A planar ion trap chip with integrated structures for an adjustable magnetic field gradient  

E-Print Network [OSTI]

field necessary for magnetic-gradient- induced coupling between ionic effective spins. We dem- onstrate] magnetic field gradient, however, such coupling is induced. Also, coupling between spin states of different-gradient- induced coupling (MAGIC). A static gradient can be generated by permanent mag- nets [15, 16] or by current

Wunderlich, Christof

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While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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241

High temperature corrosion research at the Albany Research Center  

SciTech Connect (OSTI)

The Severe Environment Corrosion and Erosion Research Facility (SECERF) at the Albany Research Center is operational. SECERF consists of 6 modules that share the availability of up to 10 different gases to produce environments for high temperature corrosion and erosion research. Projects to be conducted in the modules include: corrosion sensors for fossil energy systems, thermal gradient effects on high temperature corrosion, the development of sulfidation resistant alloys, determination of the effects of ash on the corrosion of metals and alloys in coal and waste combustion and coal gasification environments, high temperature erosion-corrosion of metals, and molten slag effects on refractories. Results from two areas, the effect of ash deposits on alloy corrosion and thermal gradient effects on the corrosion of metals, will be highlighted. Ash produced in coal gasifiers, coal combustors, and waste combustors, when deposited on metal surfaces, provides sites for corrosion attack and contributes chemical species that participate in the corrosion reaction. Results are presented for the corrosion of 304L stainless steel, that was either uncoated or coated with ash or with ash containing NaCl or Na2SO4, in air-water vapor mixtures at 600 C. The presence of high heat fluxes and temperature gradients in many fossil energy systems creates the need for an understanding of their effects on corrosion and oxidation. Such information would be useful for both improved alloy design and for better translation of isothermal laboratory results to field use. Temperature gradients in a solid oxide result in two changes that modify diffusion within the oxide. The first is when a gradient in point defect concentration is created within the oxide, for example, where more vacancies are expected at a higher temperature. The second change is when the presence of a temperature gradient biases the diffusion jump of an atom. Results of tests are presented for cobalt with metal surface temperatures of approximately 920-950 C in N2 plus 1-10 vol% O2 environments with a heat flux of about 40 kW/m2. Non-equilibrium thermodynamics were used to develop oxidation rate equations in temperature gradients that were combined with point defect information of CoO to predict oxidation rates.

Covino, Bernard S., Jr.; Holcomb, Gordon R.; Russell, James H.; Cramer, Stephen D.; Bullard, Sophie J.; Ziomek-Moroz, Margaret; Matthes, Steven A.; Chinn, R.E.

2002-01-01T23:59:59.000Z

242

Investigations of low-temperature geothermal potential in New York State  

SciTech Connect (OSTI)

Temperature gradient map and published heat flow data indicate a possible potential for a geothermal resource in western and central New York State. A new analysis of bottom-hole temperature data for New York State confirms the existence of three positive gradient anomalies: the East Aurora, Cayuga, and Elmira anomalies, with gradients as high as 32/sup 0/C/km, 36/sup 0/C/km, and 36/sup 0/C/km, respectively. Ground waters from two of these anomalies are enriched in silica relative to surrounding areas. Heat flows based on silica geothermometry are 50 to 70 mWm/sup -2/ for the anomalies and 41.4 mWm/sup -2/ for bordering regional flux. A correlation between Bouguer gravity anomalies and the temperature gradient map suggests that the geothermal anomalies may occur above radioactive granites in the basement.

Hodge, D.S.; De Rito, R.; Hifiker, K.; Morgan, P.; Swanberg, C.A.

1981-09-01T23:59:59.000Z

243

Gradient isolator for flow field of fuel cell assembly  

DOE Patents [OSTI]

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.

Ernst, William D. (Troy, NY)

1999-01-01T23:59:59.000Z

244

Velocity bunching in travelling wave accelerator with low acceleration gradient  

E-Print Network [OSTI]

We present the analytical and simulated results concerning the influences of the acceleration gradient in the velocity bunching process, which is a bunch compression scheme that uses a traveling wave accelerating structure as a compressor. Our study shows that the bunch compression application with low acceleration gradient is more tolerant to phase jitter and more successful to obtain compressed electron beam with symmetrical longitudinal distribution and low energy spread. We also present a transverse emittance compensation scheme to compensate the emittance growth caused by the increasing of the space charge force in the compressing process that is easy to be adjusted for different compressing factors.

Huang, Rui-Xuan; Li, Wei-Wei; Jia, Qi-Ka

2013-01-01T23:59:59.000Z

245

Discontinuous Galerkin finite element methods for gradient plasticity.  

SciTech Connect (OSTI)

In this report we apply discontinuous Galerkin finite element methods to the equations of an incompatibility based formulation of gradient plasticity. The presentation is motivated with a brief overview of the description of dislocations within a crystal lattice. A tensor representing a measure of the incompatibility with the lattice is used in the formulation of a gradient plasticity model. This model is cast in a variational formulation, and discontinuous Galerkin machinery is employed to implement the formulation into a finite element code. Finally numerical examples of the model are shown.

Garikipati, Krishna. (University of Michigan, Ann Arbor, MI); Ostien, Jakob T.

2010-10-01T23:59:59.000Z

246

Gradients of meteorological parameters in convective and nonconvective areas  

E-Print Network [OSTI]

. SYNOPTIC CONDITIONS 4. STRATIFICATION OF DATA 5. COMPUTATIONAL PROCEDURES 21 25 a. Gridding of rawinsonde data 25 b. Gradients 26 5'' lp t* 27 RESULTS 29 a. Gradients 29 1) Convective areas 29 2) Nonconvective areas 31 3) Combined areas 33 vi... air turbulence. By using airplane data from over the western United States, Scoggins (1975) has shown that CAT at 300 mb occurred 71% of the time when the magnitude of the vector horizontal wind shear -5 -1 exceeded 4. 5 x 10 sec . The horizontal...

McCown, Milton Samuel

1976-01-01T23:59:59.000Z

247

Gradient isolator for flow field of fuel cell assembly  

DOE Patents [OSTI]

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.

Ernst, W.D.

1999-06-15T23:59:59.000Z

248

On Higuchi Ghosts and Gradient Instabilities in Bimetric Gravity  

E-Print Network [OSTI]

We discuss the conditions to satisfy the Higuchi bound and to avoid gradient instabilities in the scalar sector for cosmological solutions in singly coupled bimetric gravity theories. We find that in expanding universes the ratio of the scale factors of the reference and observable metric has to increase at all times. This automatically implies a ghost-free helicity-2 sector and enforces a phantom Dark Energy. Furthermore, the condition for the absence of gradient instabilities in the scalar sector will be analyzed. Finally, we discuss whether cosmological solutions, including exotic evolutions like bouncing cosmologies, can exist, in which both the Higuchi ghost and scalar instabilities are absent at all times.

Könnig, Frank

2015-01-01T23:59:59.000Z

249

Development of Robust Analog and Mixed-Signal Circuits in the Presence of Process- Voltage-Temperature Variations  

E-Print Network [OSTI]

for transconductance amplifiers.................................7 I.2.2. Process variation-aware quantization ...........................................................8 I.2.3. Non-invasive on-chip measurement of thermal gradients and RF power.....9 I.2.4. Analog... .....................................................................................107 V. AN ON-CHIP TEMPERATURE SENSOR TO MEASURE RF POWER DISSIPATION AND THERMAL GRADIENTS.....................................................109 V.1. Background...

Onabajo, Marvin Olufemi

2012-07-16T23:59:59.000Z

250

Solid state electron-hopping transport and frozen concentration gradients in a mixed valent viologen-tetraethylene oxide copolymer  

SciTech Connect (OSTI)

This paper describes electrochemistry and electron-hopping dynamics for a novel viologen-based redox polymer (poly-V{sup 2+}) formed from the copolymerization of tetraethylene glycol di-p-tosylate and 4,4{prime}-bipyridine. Current-potential responses and electron-hopping (i.e., self-exchange) rates have been measured for mixed valent films of poly-V{sup 2+} on interdigitated array electrodes contacted by tetrahydrofuran/acetonitrile/tetrabutylammonium perchlorate electrolyte solution and as dry mixed valent films in vacuum or dry nitrogen. Electron transfer rates vary with the mixed valency composition of poly-V{sup 2+/+} films (judging film composition from the electrolysis potential with the Nernst equation) according to bimolecular reaction theory for solvent-wetted but less well for dry films. Current-potential characteristics are also reported for mixed valent films that contain concentration gradients of the poly-V{sup 2+} and poly-V{sup +} redox states, which we attempt to freeze into place by drying the film under a gradient-generating potential bias so as to immobilize the film`s counterions. Current transients at room and reduced (-30{degree}C) temperature show that the room-temperature responses of films containing concentration gradients are sensitive to small changes in poly-V{sup 2+/+} oxidation state at the electrode/polymer interfaces. 24 refs., 9 figs., 1 tab.

Terrill, R.H.; Hutchison, J.E.; Murray, R.W. [Univ. of North Carolina, Chapel Hill, NC (United States)] [Univ. of North Carolina, Chapel Hill, NC (United States)

1997-02-27T23:59:59.000Z

251

Computing several eigenpairs of Hermitian problems by conjugate gradient iterations  

SciTech Connect (OSTI)

The paper is concerned with algorithms for computing several extreme eigenpairs of Hermitian problems based on the conjugate gradient method. We analyse computational strategies employed by various algorithms of this kind reported in the literature and identify their limitations. Our criticism is illustrated by numerical tests on a set of problems from electronic structure calculations and acoustics.

Ovtchinnikov, E.E. [Harrow School of Computer Science, University of Westminster, Watford Road, Northwick Park, London HA1 3TP (United Kingdom)], E-mail: e_ovtchinnikov@hotmail.com

2008-11-20T23:59:59.000Z

252

BIOGEOCHEMICAL GRADIENTS AS A FRAMEWORK FOR UNDERSTANDING WASTE SITE EVOLUTION  

SciTech Connect (OSTI)

The migration of biogeochemical gradients is a useful framework for understanding the evolution of biogeochemical conditions in groundwater at waste sites contaminated with metals and radionuclides. This understanding is critical to selecting sustainable remedies and evaluating sites for monitored natural attenuation, because most attenuation mechanisms are sensitive to geochemical conditions such as pH and redox potential. Knowledge of how gradients in these parameters evolve provides insights into the behavior of contaminants with time and guides characterization, remedy selection, and monitoring efforts. An example is a seepage basin site at the Savannah River Site in South Carolina where low-level acidic waste has seeped into groundwater. The remediation of this site relies, in part, on restoring the natural pH of the aquifer by injecting alkaline solutions. The remediation will continue until the pH up-flow of the treatment zone increases to an acceptable value. The time required to achieve this objective depends on the time it takes the trailing pH gradient, the gradient separating the plume from influxing natural groundwater, to reach the treatment zone. Predictions of this length of time will strongly influence long-term remedial decisions.

Denham, M; Karen Vangelas, K

2008-10-17T23:59:59.000Z

253

Soil macroaggregate dynamics in a mountain spatial climate gradient  

E-Print Network [OSTI]

Soil macroaggregate dynamics in a mountain spatial climate gradient Lauric Cécillon1,2,* , Nilvania://lauric.cecillon.free.fr/ Key words: Mountain soils; Climate change; Soil aggregation; Soil organic matter; Near infrared reflectance spectroscopy; Soil threats Biogeochemistry 97: 31-43 (2010) http://dx.doi.org/10.1007/s10533

Paris-Sud XI, Université de

254

Gradient Improvement by Removal of Identified Local Defects  

SciTech Connect (OSTI)

Recent experience of ILC cavity processing and testing at Jefferson Lab has shown that some 9-cell cavities are quench limited at a gradient in the range of 15-25 MV/m. Further studies reveal that these quench limits are often correlated with sub-mm sized and highly localized geometrical defects at or near the equator weld. There are increasing evidence to show that these genetic defects have their origin in the material or in the electron beam welding process (for example due to weld irregularities or splatters on the RF surface and welding porosity underneath the surface). A local defect removal method has been proposed at Jefferson Lab by locally re-melting the niobium material. Several 1-cell cavities with known local defects have been treated by using the JLab local e-beam re-melting method, resulting in gradient and Q0 improvement. We also sent 9-cell cavities with known gradient limiting local defects to KEK for local grinding and to FNAL for global mechanical polishing. We report on the results of gradient improvements by removal of local defects in these cavities.

R.L. Geng, W.A. Clemens, C.A. Cooper, H. Hayano, K. Watanabe

2011-07-01T23:59:59.000Z

255

Online gradient descent learning algorithms Yiming Ying and Massimiliano Pontil  

E-Print Network [OSTI]

Online gradient descent learning algorithms Yiming Ying and Massimiliano Pontil Department of Computer Science, University College London Gower Street, London, WC1E 6BT, England, UK {y.ying, m, 62L20. Contact author: Yiming Ying, Telephone: +44 (0)20 7387 0374, Fax: +44 (0)20 7387 1397 1 #12

Pontil, Massimiliano

256

Online gradient descent learning algorithm Yiming Ying and Massimiliano Pontil  

E-Print Network [OSTI]

Online gradient descent learning algorithm Yiming Ying and Massimiliano Pontil Department of Computer Science, University College London Gower Street, London, WC1E 6BT, England, UK {y.ying, m Numbers: 68Q32, 68T05, 62J02, 62L20. Contact author: Yiming Ying, Telephone: +44 (0)20 7679 0374, Fax

Ying, Yiming

257

Simulation of IPA Gradients in Hybrid Network Systems Benjamin Melamed  

E-Print Network [OSTI]

Simulation of IPA Gradients in Hybrid Network Systems Benjamin Melamed Rutgers University Rutgers Atlanta, GA 30332 October 26, 2005 Abstract Infinitesimal Perturbation Analysis (IPA) provides formulas paths of stochastic systems. In practice, IPA derivatives may be computed either from simulation runs

258

Scaling limits for gradient systems in random environment  

E-Print Network [OSTI]

For interacting particle systems that satisfies the gradient condition, the hydrodynamic limit and the equilibrium fluctuations are well known. We prove that under the presence of a symmetric random environment, these scaling limits also hold for almost every choice of the environment, with homogenized coefficients that does not depend on the particular realization of the random environment.

P. Goncalves; M. D. Jara

2007-02-17T23:59:59.000Z

259

Seasonal mass balance gradients in Norway L. A. Rasmussen1  

E-Print Network [OSTI]

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

Rasmussen, L.A.

260

The Urban Environmental Gradient: Anthropogenic Influences on the  

E-Print Network [OSTI]

Georgia, through Atlanta, to the Gulf of Mexico and reflects a steep gradient in population density from as vehicular traffic. Introduction Many of the common anthropogenic pollution problems are focused in urban geographic areas. Suburbia does not contribute much by way of industrial pollution, but it does serve

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


261

Continuous Edge Gradient-Based Template Matching for Articulated  

E-Print Network [OSTI]

Zachmann IfI Technical Report Series IfI-09-01 #12;Impressum Publisher: Institut fĂĽr Informatik, Technische (Technical Computer Science) Prof. Dr. Gabriel Zachmann (Computer Graphics) #12;Continuous Edge Gradient-Based Template Matching for Articulated Objects Daniel Mohr and Gabriel Zachmann Abstract Detection

Zachmann, Gabriel

262

Non-axisymmetric wind-accretion simulations; 2, Density gradients  

E-Print Network [OSTI]

The hydrodynamics of a variant of classical Bondi-Hoyle-Lyttleton accretion is investigated: a totally absorbing sphere moves at various Mach numbers (3 and 10) relative to a medium, which is taken to be an ideal gas having a density gradient (of 3%, 20% or 100% over one accretion radius) perpendicular to the relative motion. Similarly to the 3D models published previously, both with velocity gradients and without, the models with a density gradient presented here exhibit non-stationary flow patterns, although the Mach cone remains fairly stable. The accretion rates of mass, linear and angular momenta do not fluctuate as strongly as published previously for 2D models. No obvious trend of the dependency of mass accretion rate fluctuations on the density gradient can be discerned. The average specific angular momentum accreted is roughly between zero and 70% of the total angular momentum available in the accretion cylinder in the cases where the average is prograde. Due to the large fluctuations during accretio...

Ruffert, M

1999-01-01T23:59:59.000Z

263

A distributed accelerated gradient algorithm for distributed model predictive  

E-Print Network [OSTI]

of hydro power plants is to manage the available water resources efficiently, while following an optimal is applied to the power reference tracking problem of a hydro power valley (HPV) system. The applied power control, Distributed optimization, Accelerated gradient algorithm, Model predictive control

Como, Giacomo

264

A study of microbend test by strain gradient plasticity  

E-Print Network [OSTI]

A study of microbend test by strain gradient plasticity W. Wanga , Y. Huangb, *, K.J. Hsiac , K with plastic deformation is on the order of microns. This size effect cannot be explained by classical plasticity theories since their constitutive relations do not have an intrinsic material length. Strain

Hsia, K Jimmy

265

Treated Wastewater Effluent Reduces Sperm Motility Along an Osmolality Gradient  

E-Print Network [OSTI]

Treated Wastewater Effluent Reduces Sperm Motility Along an Osmolality Gradient H. L. Schoenfuss Ă? 2008 Ă? Springer Science+Business Media, LLC 2008 Abstract Many toxic effects of treated wastewater environment of treated wastewater effluent frequently differs consider- ably from that of its receiving waters

Julius, Matthew L.

266

GEOTHERMAL GRADIENT DATA FOR UTAH Robert E. Blackett  

E-Print Network [OSTI]

GEOTHERMAL GRADIENT DATA FOR UTAH by Robert E. Blackett February 2004 UTAH GEOLOGICAL SURVEY ­ 1:750,000 scale map, showing geology; thermal wells, springs, and geothermal areas; and locations available sources including the Southern Methodist University Geothermal Laboratory, U.S. Geological Survey

Laughlin, Robert B.

267

Geothermal Resource/Reservoir Investigations Based on Heat Flow and Thermal Gradient Data for the United States  

SciTech Connect (OSTI)

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.

D. D. Blackwell; K. W. Wisian; M. C. Richards; J. L. Steele

2000-04-01T23:59:59.000Z

268

Observation of pressure gradient and related flow rate effect on the plasma parameters in plasma processing reactor  

SciTech Connect (OSTI)

In industrial plasma processes, flow rate has been known to a key to control plasma processing results and has been discussed with reactive radical density, gas residence time, and surface reaction. In this study, it was observed that the increase in the flow rate can also change plasma parameters (electron temperature and plasma density) and electron energy distribution function in plasma processing reactor. Based on the measurement of gas pressure between the discharge region and the pumping port region, the considerable differences in the gas pressure between the two regions were found with increasing flow rate. It was also observed that even in the discharge region, the pressure gradient occurs at the high gas flow rate. This result shows that increasing the flow rate results in the pressure gradient and causes the changes in the plasma parameters.

Lee, Hyo-Chang; Kim, Aram; Chung, Chin-Wook [Department of Electrical Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Moon, Se Youn [Solar Energy Group, LG Electronics Advanced Research Institute, 16 Woomyeon-Dong, Seocho-Gu, Seoul 137-724 (Korea, Republic of)

2011-02-15T23:59:59.000Z

269

North-south asymmetry in solar activity: predicting the amplitude of the next solar cycle  

E-Print Network [OSTI]

Using Greenwich and SOON sunspot group data during the period 1874 -- 2005, we find that the sums of the areas of the sunspot groups in $0^\\circ$ -- $10^\\circ$ latitude-interval of the Sun's northern hemisphere and in the time-interval, minus 1.35 year to plus 2.15 year from the time of the preceding minimum--and in the same latitude interval of the southern hemisphere but plus 1.0 year to plus 1.75 year from the time of the maximum--of a sunspot cycle are well correlating with the amplitude (maximum of the smoothed monthly sunspot number) of its immediate following cycle. Using this relationship it is possible to predict the amplitude of a sunspot cycle by about 9 -- 13 years in advance. We predicted $74 \\pm 10$ for the amplitude of the upcoming cycle~24. Variations in solar meridional flows during solar cycles and 9 -- 16 year variations in solar equatorial rotation may be responsible for the aforementioned relationship.

J. Javaraiah

2007-01-31T23:59:59.000Z

270

NCCR North-South Dialogue, no. 38 India and the Millennium  

E-Print Network [OSTI]

, including women and young people 21 3.1 Indicator 4: GDP per person employed 21 3.2 Indicator 5: Employment in India, 1977-78 to 2004-05, in per cent 12 Figure 3: GDP per person employed, India, 1980 to 2008: Proportion of population below minimum level of dietary energy consumption 34 5 The Policy Approach

Richner, Heinz

271

Training Demands in Inter-and Transdisciplinary Research Contexts Photo: NCCR North-South  

E-Print Network [OSTI]

-academic actors (transdisciplinarity) Rethinking ... roles of student and instructors didactics and learning

Richner, Heinz

272

Beamline Temperatures  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAboutScience ProgramBackground8.0.1 PrintTemperatures Energy: 3.0000 GeV

273

Atom interferometric techniques for measuring gravitational acceleration and constant magnetic field gradients  

E-Print Network [OSTI]

We discuss two techniques for probing the effects of a homogeneous force acting on cold atoms, such as that due to gravity or a constant magnetic field gradient, using grating echo-type atom interferometers. A comprehensive theoretical description of signals generated by both two-pulse and three-pulse interferometers, accounting for magnetic sub-levels in the atomic ground state, is shown to agree with experimental results. Laser-cooled samples of $^{85}$Rb with temperatures as low as 2.4 $\\mu$K have been achieved in a relatively large glass cell with well-suppressed magnetic fields. Using transit time limited interferometer signals, we demonstrate sensitivity to externally applied magnetic gradients as small as $\\sim 4$ mG/cm. With these timescales we estimate that precision measurements of the gravitational acceleration, $g$, are possible with both the two-pulse and three-pulse echo interferometers. Whereas the two-pulse signal is a position-sensitive technique to measure the absolute value of $g$, the thre...

Barrett, B

2011-01-01T23:59:59.000Z

274

Daily results of the initial operation of the Los Alamos salt-gradient solar pond  

SciTech Connect (OSTI)

The results of analysis of the initial data obtained on the Los Alamos National Laboratory salt-gradient solar pond, a 232 m/sup 2/ pond constructed for the primary purpose of studying pond hydrodynamics, are presented. The pond and the data-acquisition system were complete and in full operation by August 14, 1982. By September 21, 1982, the lower convecting zone had reached a temperature of 56/sup 0/C. An energy balance was performed over this period and is presented. Soil conductivity determinations have been made from the data, and the method is discussed. As a result of a leak discovered in the pond in September, a method of determining the leak rate was developed, and the results are included.

Hedstrom, J.C.; Jones, G.F.; Meyer, K.A.

1983-01-01T23:59:59.000Z

275

Fabrication process for a gradient index x-ray lens  

DOE Patents [OSTI]

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.

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

1995-01-01T23:59:59.000Z

276

Gradient Plasticity Model and its Implementation into MARMOT  

SciTech Connect (OSTI)

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.

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

2013-08-01T23:59:59.000Z

277

Gradient instabilities of electromagnetic waves in Hall thruster plasma  

SciTech Connect (OSTI)

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.

Tomilin, Dmitry [Department of Electrophysics, Keldysh Research Centre, Moscow 125438 (Russian Federation)

2013-04-15T23:59:59.000Z

278

Determination of dispersivities from a natural-gradient dispersion test  

E-Print Network [OSTI]

, and radioactive wastes. Contaminant hydrogeology is presently a focal point in the realm of hydrologic modeling. Generally, models are designed to represent simplified versions of reality and The style and format of this document was taken from the Journal... dispersivities, v ia a graphical approach, from a natural-gradient dispersion test in which artificial pollution was injected into an aquifer. The dispersion test was conducted by Sud icky et al. (1983) in order to characterize the dispersive properties...

Hoover, Caroline Marie

1985-01-01T23:59:59.000Z

279

Novel geometry gradient coils for MRI designed by genetic algorithm  

E-Print Network [OSTI]

in the Steady State High Performance Computing Facility Herchel Smith Laboratory for Medicinal Chemistry Message Passing Interface Magnetic Resonance Imaging Positron Emission Tomography Radio frequency Electro-motive force Root mean squared IX & x... by the intro­ duction of high performance computing. One of the major disadvantages of this approach . to gradient design is the amount of time taken to produce results, and high performance computing has the potential to reduce this. The amount by which a...

Williams, Guy Barnett

2001-06-19T23:59:59.000Z

280

PATTERNS OF LEAF WETTABILITY ALONG AN EXTREME MOISTURE GRADIENT IN WESTERN PATAGONIA, ARGENTINA  

E-Print Network [OSTI]

PATTERNS OF LEAF WETTABILITY ALONG AN EXTREME MOISTURE GRADIENT IN WESTERN PATAGONIA, ARGENTINA Patagonia, Argentina. Morphological and structural characteristics of leaves significantly affected leaf surfaces. Keywords: leaf wetness, morphology, water droplet, Patagonia, gradient. Introduction A large

Brewer, Carol

Note: This page contains sample records for the topic "north-south temperature gradient" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
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281

Creation of nonlinear density gradients for use in internal wave research  

E-Print Network [OSTI]

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

Harris, Victoria Siân

2007-01-01T23:59:59.000Z

282

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

E-Print Network [OSTI]

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 industry. One such method...

Oluwadairo, Tolulope

2009-05-15T23:59:59.000Z

283

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

E-Print Network [OSTI]

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. ...

Vidula, Mahesh K.

284

CONTINUOUS EDGE GRADIENT-BASED TEMPLATE MATCHING FOR ARTICULATED OBJECTS  

E-Print Network [OSTI]

template matching, deformable object detection, confidence map, edge feature, graphics hardware In this paper, we propose a novel edge gradient based template matching method for object detection. In contrast to other methods, ours does not perform any binarization or discretization during the online matching. This is facilitated by a new continuous edge gradient similarity measure. Its main components are a novel edge gradient operator, which is applied to query and template images, and the formulation as a convolution, which can be computed very efficiently in Fourier space. We compared our method to a state-of-the-art chamfer based matching method. The results demonstrate that our method is much more robust against weak edge response and yields much better confidence maps with fewer maxima that are also more significant. In addition, our method lends itself well to efficient implementation on GPUs: at a query image resolution of 320 × 256 and a template resolution of 80 × 80 we can generate about 330 confidence maps per second. 1

Daniel Mohr; Gabriel Zachmann

285

Statistical Estimates For Channel Flows Driven By A Pressure Gradient  

E-Print Network [OSTI]

We present rigorous estimates for some physical quantities related to turbulent and non-turbulent channel flows driven by a uniform pressure gradient. Such results are based on the concept of stationary statistical solution, which is related to the notion of ensemble average for flows in statistical equilibrium. We provide a lower bound estimate for the mean skin friction coefficient and improve on a previous upper bound estimate for the same quantity; both estimates in terms of the Reynolds number. We also present lower and upper bound estimates for the mean rate of energy dissipation, the mean longitudinal velocity (in the direction of the pressure gradient), and the mean kinetic energy. In particular, we obtain an upper bound related to the energy dissipation law, namely that the mean rate of energy dissipation is essentially bounded by a non-dimensional universal constant times the cube of the mean longitudinal velocity over a characteristic macro-scale length. Finally, we investigate the scale-by-scale energy injection due to the pressure gradient, proving an upper bound estimate for the decrease of this energy injection as the scale length decreases.

Fabio Ramos; Ricardo Rosa; Roger Temam

2006-12-14T23:59:59.000Z

286

Solar rotation rate and its gradients during cycle 23  

E-Print Network [OSTI]

Available helioseismic data now span almost the entire solar activity cycle 23 making it possible to study solar-cycle related changes of the solar rotation rate in detail. In this paper we study how the solar rotation rate, in particular, the zonal flows change with time. In addition to the zonal flows that show a well known pattern in the solar convection zone, we also study changes in the radial and latitudinal gradients of the rotation rate, particularly in the shear layer that is present in the immediate sub-surface layers of the Sun. In the case of the zonal-flow pattern, we find that the band indicating fast rotating region close to the equator seems to have bifurcated around 2005. Our investigation of the rotation-rate gradients show that the relative variation in the rotation-rate gradients is about 20% or more of their average values, which is much larger than the relative variation in the rotation rate itself. These results can be used to test predictions of various solar dynamo models.

H. M. Antia; Sarbani Basu; S. M. Chitre

2008-05-22T23:59:59.000Z

287

Diffusion coefficient and radial gradient of galactic cosmic rays  

E-Print Network [OSTI]

We present the temporal changes of the diffusion coefficient K of galactic cosmic rays (GCRs) at the Earth orbit calculated based on the experimental data using two different methods. The first approach is based on the Parker convection-diffusion approximation of GCR modulation [1]: i.e. K~Vr=dI where dI is the variation of the GCR intensity measured by neutron monitors (NM),V is the solar wind velocity and r is the radial distance. The second approach is based on the interplanetary magnetic field (IMF) data. It was suggested that parallel mean free path can be expressed in terms of B as in [2]-[4]. Using data of the product of the parallel mean free path and radial gradient of GCR calculated based on the GCR anisotropy data (Ahluwalia et al., this conference ICRC 2013, poster ID: 487 [5]), we estimate the temporal changes of the radial gradient of GCR at the Earth orbit. We show that the radial gradient exhibits a strong solar cycle dependence (11-year variation) and a weak solar magnetic cycle dependence (2...

Modzelewska, Renata

2015-01-01T23:59:59.000Z

288

Hottest spot temperatures in ventilated dry type transformers  

SciTech Connect (OSTI)

The hottest spot temperature allowance to be used for the different insulation system temperature classes is a major unknown facing IEEE Working Groups developing standards and loading guides for ventilated dry type transformers. In 1944, the hottest spot temperature allowance for ventilated dry type transformers was established as 30 C for 80 C average winding temperature rise. Since 1944, insulation temperature classes have increased to 220 C but IEEE standards continue to use a constant 30 C hottest spot temperature allowance. IEC standards use a variable hottest spot temperature allowance from 5 to 30 C. Six full size test windings were manufactured with imbedded thermocouples and 133 test runs performed to obtain temperature rise data. The test data indicated that the hottest spot temperature allowance used in IEEE standards for ventilated dry type transformers above 500 kVA is too low. This is due to the large thermal gradient from the bottom to the top of the windings caused by natural convection air flow through the cooling ducts. A constant ratio of hottest spot winding temperature rise to average winding temperature rise should be used in product standards for all insulation temperature classes. A ratio of 1.5 is suggested for ventilated dry type transformers above 500 kVA. This would increase the hottest spot temperature allowance from 30 C to 60 C and decrease the permissible average winding temperature rise from 150 C to 120 C for the 220 C insulation temperature class.

Pierce, L.W. (General Electric Co., Rome, GA (United States))

1994-01-01T23:59:59.000Z

289

RAL-TR-2002-034 A Stopping Criterion for the Conjugate Gradient Algorithm in  

E-Print Network [OSTI]

Method Framework Mario Arioli 1 ABSTRACT The Conjugate Gradient method has always been successfully used for the conjugate gradient method 5 4 Numerical experiments 10 4.1 L-shape test problems stopping criterion for the conjugate gradient algorithm. The #12;nite element method approximates the weak

Mihajlovic, Milan D.

290

Ilya Lashuk and Andrew Knyazev 1 Steepest descent and conjugate gradient methods  

E-Print Network [OSTI]

Ilya Lashuk and Andrew Knyazev 1 Steepest descent and conjugate gradient methods with variable Mountain Conference 2006 Steepest descent and conjugate gradient methods with variable preconditioning #12 Steepest descent and conjugate gradient methods with variable preconditioning #12;Ilya Lashuk and Andrew

Knyazev, Andrew

291

A Set of Conjugate Gradient Routines for Real and Complex Arithmetics  

E-Print Network [OSTI]

The Conjugate Gradient method was proposed in different versions in the early 50s in separate contributionsA Set of Conjugate Gradient Routines for Real and Complex Arithmetics Val´erie Frayss´e Luc Giraud of the preconditioned conjugate gradient (CG) algorithm for both real and complex, single and double precision

292

Preconditioned conjugate gradient method for the sparse generalized eigenvalue problem in electronic structure  

E-Print Network [OSTI]

Preconditioned conjugate gradient method for the sparse generalized eigenvalue problem based on the conjugate gradient method is presented. The method is applied to first­principles elec problem, cast into variational form, is solved by the conjugate gradient method without first transforming

Haynes, Peter

293

Performance and Scalability of Preconditioned Conjugate Gradient Methods on Parallel Computers \\Lambda  

E-Print Network [OSTI]

Performance and Scalability of Preconditioned Conjugate Gradient Methods on Parallel Computers­scale parallel computers, iterative methods such as the Conjugate Gradient method for solving such systems of an iteration of the Preconditioned Conjugate Gradient Algorithm on parallel architectures with a variety

Kumar, Vipin

294

A Set of Conjugate Gradient Routines for Real and Complex Arithmetics  

E-Print Network [OSTI]

systems, Krylov methods, CG, reverse communication, distributed mem­ ory. 1 The Conjugate Gradient algorithm 1.1 General description The Conjugate Gradient method was proposed in di#erent versions with the symmetric Lanczos matrix There is a close relationship between the conjugate gradient method and the Lanczos

295

Solving a Two-Dimensional Elliptic Model Problem with the Conjugate Gradient Method Using  

E-Print Network [OSTI]

Solving a Two-Dimensional Elliptic Model Problem with the Conjugate Gradient Method Using Matrix Preconditioned Conjugate Gradient method in Matlab can be optimized in terms of wall clock time and, more-free Preconditioned Conjugate Gradient method. This superior algorithm computes the same numerical solution to our

Gobbert, Matthias K.

296

Conjugate gradient method for dual-dual mixed formulations Gabriel N. Gatica y Norbert Heuer z  

E-Print Network [OSTI]

Conjugate gradient method for dual-dual mixed formulations #3; Gabriel N. Gatica y Norbert Heuer z, the conjugate gradient method with this special inner product can be used as iterative solver. For a model-dual variational formulation, conjugate gradient method. Mathematics subject classi#12;cations (1991). 65N30, 65N22

Heuer, Norbert

297

Convergence of Three-term Conjugate Gradient Methods Y. H. Dai and Y. Yuan  

E-Print Network [OSTI]

Convergence of Three-term Conjugate Gradient Methods Y. H. Dai and Y. Yuan State Key Laboratory@lsec.cc.ac.cn, yyx@lsec.cc.ac.cn Abstract This paper studies the three-term conjugate gradient method for unconstrained opti- mization. The method includes the classical (two-term) conjugate gradient method

Yuan, Ya-xiang

298

Time Complexity of a Parallel Conjugate Gradient Solver for Light Scattering Simulations  

E-Print Network [OSTI]

parallelization for distributed memory computers of a preconditioned Conjugate Gradient method, applied to solve of the Conjugate Gradient method is analyzed theoretically. First expressions for the execution time for three, preconditioned conjugate gradient method, data decomposition, time complexity analysis, performance measurement

Hoffmann, Walter

299

A fast GPU Implementation of the Deflated Preconditioned Conjugate Gradient method  

E-Print Network [OSTI]

A fast GPU Implementation of the Deflated Preconditioned Conjugate Gradient method List of authors to the fastest method: DIPCG2. · (CGVV) Conjugate Gradient - Vanilla Version, · (CGBIC) Conjugate Gradient Preconditioned Conjugate Gra- dient Method. Most of the important building blocks of this algorithm could

Boyer, Edmond

300

The Role of the Inner Product in Stopping Criteria for Conjugate Gradient Iterations  

E-Print Network [OSTI]

stopping criteria are derived for conjugate gradient (CG) methods, based on iteration parameters criteria, conjugate gradient methods, B-normal matrices 1 Introduction Unlike a direct method, an iterative1 The Role of the Inner Product in Stopping Criteria for Conjugate Gradient Iterations S. F. Ashby

Holst, Michael J.

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


301

Implementation of a parallel conjugate gradient method for simulation of elastic light scattering  

E-Print Network [OSTI]

1 Implementation of a parallel conjugate gradient method for simulation of elastic light scattering solved with (preconditioned) conjugate gradient methods. For realistic problems the size of the matrix gradient method for this type of problems, with emphasis on coarse grain distributed memory implementations

302

Copyright information to be inserted by the Publishers ANALYSIS ON THE CONJUGATE GRADIENT  

E-Print Network [OSTI]

Copyright information to be inserted by the Publishers ANALYSIS ON THE CONJUGATE GRADIENT METHOD YA 17 January 1993) In this paper we analyze the conjugate gradient method when the objective function is quadratic. We apply backward analyses to study the quadratic termination of the conjugate gradient method

Yuan, Ya-xiang

303

Exploiting hyper-sparsity when computing preconditioners for conjugate gradients in interior point methods  

E-Print Network [OSTI]

for conjugate gradients in interior point methods 1 #12;Hyper-sparsity in operations with B-1 Represent B-1 computing preconditioners for conjugate gradients in interior point methods 3 #12;Interior point methods computing preconditioners for conjugate gradients in interior point methods 4 #12;Design

Hall, Julian

304

Algorithm PREQN: Fortran 77 Subroutines for Preconditioning the Conjugate Gradient Method  

E-Print Network [OSTI]

Algorithm PREQN: Fortran 77 Subroutines for Preconditioning the Conjugate Gradient Method Jos subroutines for automatically generating pre­ conditioners for the conjugate gradient method. It is designed the conjugate gradient method. They are designed for solving a sequence of linear systems, A i x = b i ; i = 1

Nocedal, Jorge

305

A conjugate-gradient based approach for approximate solutions of quadratic programs  

E-Print Network [OSTI]

on the two-norm of the columns, the method is equivalent to the conjugate-gradient method. Further, the above, the numerical results demonstrate that, like the conjugate-gradient method, a rapid decrease of the objective. column generation, conjugate-gradient method, intensity-modulated radiation therapy, step

Forsgren, Anders

306

3D Shape from Silhouette Points in Registered 2D Images Using Conjugate Gradient Method  

E-Print Network [OSTI]

3D Shape from Silhouette Points in Registered 2D Images Using Conjugate Gradient Method Andrzej version of the conjugate gradient method. We take advantage of the structure of the problem to make polynomial function. The approximate problem is solved using a nonlinear conjugate gradient solver that takes

Hoff, William A.

307

Algorithm PREQN: Fortran 77 Subroutines for Preconditioning the Conjugate Gradient Method  

E-Print Network [OSTI]

Algorithm PREQN: Fortran 77 Subroutines for Preconditioning the Conjugate Gradient Method Jose Luis for automatically generating pre- conditioners for the conjugate gradient method. It is designed for solving: Preconditioning, conjugate gradient method, quasi- Newton method, Hessian-free Newton method, limited memory

Nocedal, Jorge

308

PRECONDITIONED CONJUGATE GRADIENT METHODS FOR THE INCOMPRESSIBLE NAVIER-STOKES EQUATIONS  

E-Print Network [OSTI]

PRECONDITIONED CONJUGATE GRADIENT METHODS FOR THE INCOMPRESSIBLE NAVIER-STOKES EQUATIONS P. CHIN of using a conjugate gradient type method with an incomplete LU factorization preconditioner for two is to use an iterative matrix method. Recently, several authors have applied conjugate gradient type methods

Waterloo, University of

309

Parallelizable Preconditioned Conjugate Gradient Methods for the Cray Y-MP and the TMC CM-2  

E-Print Network [OSTI]

Parallelizable Preconditioned Conjugate Gradient Methods for the Cray Y-MP and the TMC CM-2 William preconditioned conjugate gradient methods to the numerical solution of the diffusion equation governing the flow provides a comparison of the performance characteristics of several preconditioned conjugate gradient (PCG

Navon, Michael

310

A MULTI-PRECONDITIONED CONJUGATE GRADIENT ROBERT BRIDSON AND CHEN GREIF  

E-Print Network [OSTI]

propose a generalization of the conjugate gradient method that uses multiple preconditioners, combining and differences with the standard and block conjugate gradient methods. Numerical examples illustrate and validate, preconditioning, Krylov subspace solvers 1. Introduction. The conjugate gradient (CG) method is celebrating its 53

Bridson, Robert

311

A SURVEY OF NONLINEAR CONJUGATE GRADIENT METHODS WILLIAM W. HAGER AND HONGCHAO ZHANG  

E-Print Network [OSTI]

A SURVEY OF NONLINEAR CONJUGATE GRADIENT METHODS WILLIAM W. HAGER AND HONGCHAO ZHANG Abstract. This paper reviews the development of different versions of nonlinear conjugate gradient methods, with special attention given to global convergence properties. Key words. Nonlinear conjugate gradient methods

Zhang, Hongchao

312

ON THE BEHAVIOR OF THE CONJUGATE-GRADIENT METHOD ON ILL-CONDITIONED PROBLEMS  

E-Print Network [OSTI]

ON THE BEHAVIOR OF THE CONJUGATE-GRADIENT METHOD ON ILL-CONDITIONED PROBLEMS Anders FORSGREN Abstract We study the behavior of the conjugate-gradient method for solving a set of linear equations. conjugate-gradient method, symmetric positive-definite ma- trix, ill-conditioning AMS subject

Forsgren, Anders

313

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

E-Print Network [OSTI]

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

Lyakhovsky, Vladimir

314

Adaptive Restart for Accelerated Gradient Schemes Brendan O'Donoghue Emmanuel Cand`es  

E-Print Network [OSTI]

Adaptive Restart for Accelerated Gradient Schemes Brendan O'Donoghue Emmanuel Cand`es April 13- matically improve the convergence rate of accelerated gradient schemes. The analysis of the technique relies. In what we refer to as the `high momentum' regime the iterates generated by an accelerated gradient scheme

Candes, Emmanuel J.

315

Solar production of intermediate temperature process heat. Phase I design. Final report. [For sugarcane processing plant in Hawaii  

SciTech Connect (OSTI)

This report is the final effort in the Phase I design of a solar industrial process heat system for the Hilo Coast Processing Company (HCPC) in Pepeekeo, Hawaii. The facility is used to wash, grind and extract sugar from the locally grown sugarcane and it operates 24 hours a day, 305 days per year. The major steam requirements in the industrial process are for the prime movers (mill turbines) in the milling process and heat for evaporating water from the extracted juices. Bagasse (the fibrous residue of milled sugarcane) supplied 84% of the fuel requirement for steam generation in 1979, while 65,000 barrels of No. 6 industrial fuel oil made up the remaining 16%. These fuels are burned in the power plant complex which produces 825/sup 0/F, 1,250 psi superheated steam to power a turbogenerator set which, in addition to serving the factory, generates from 7 to 16 megawatts of electricity that is exported to the local utility company. Extracted steam from the turbo-generator set supplies the plant's process steam needs. The system consists of 42,420 ft./sup 2/ of parabolic trough, single axis tracking, concentrating solar collectors. The collectors will be oriented in a North-South configuration and will track East-West. A heat transfer fluid (Gulf Synfluid 4cs) will be circulated in a closed loop fashion through the solar collectors and a series of heat exchangers. The inlet and outlet fluid temperatures for the collectors are 370/sup 0/F and 450/sup 0/F respectively. It is estimated that the net useable energy delivered to the industrial process will be 7.2 x 10/sup 9/ Btu's per year. With an HCPC boiler efficiency of 78% and 6.2 x 10/sup 6/ Btu's per barrel of oil, the solar energy system will displace 1489 barrels of oil per year. (WHK)

None

1980-08-01T23:59:59.000Z

316

High Temperatures & Electricity Demand  

E-Print Network [OSTI]

High Temperatures & Electricity Demand An Assessment of Supply Adequacy in California Trends.......................................................................................................1 HIGH TEMPERATURES AND ELECTRICITY DEMAND.....................................................................................................................7 SECTION I: HIGH TEMPERATURES AND ELECTRICITY DEMAND ..........................9 BACKGROUND

317

High and ulta-high gradient quadrupole magnets  

SciTech Connect (OSTI)

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%.

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

1985-05-01T23:59:59.000Z

318

The gradient flow running coupling with twisted boundary conditions  

E-Print Network [OSTI]

We study the gradient flow for Yang-Mills theories with twisted boundary conditions. The perturbative behavior of the energy density $\\langle E(t)\\rangle$ is used to define a running coupling at a scale given by the linear size of the finite volume box. We compute the non-perturbative running of the pure gauge $SU(2)$ coupling constant and conclude that the technique is well suited for further applications due to the relatively mild cutoff effects of the step scaling function and the high numerical precision that can be achieved in lattice simulations. We also comment on the inclusion of matter fields.

A. Ramos

2014-09-04T23:59:59.000Z

319

Fabrication of high gradient insulators by stack compression  

DOE Patents [OSTI]

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.

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

2014-04-29T23:59:59.000Z

320

Superconducting travelling wave ring with high gradient accelerating section  

SciTech Connect (OSTI)

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

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

2007-06-01T23:59:59.000Z

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


321

Gradient index liquid crystal devices and method of fabrication thereof  

DOE Patents [OSTI]

Laser beam apodizers using cholesteric liquid crystals provides soft edge profile by use of two separate cholesteric liquid crystal mixtures with different selective reflection bands which in an overlap region have a gradient index where reflectivity changes as a function of position. The apodizers can be configured as a one-dimensional beam apod INTRODUCTION The U.S. government has rights in the invention under Contract No. DE-FC03-85DP40200 between the University of Rochester and the Department of Energy.

Lee, J.C.; Jacobs, S.

1991-10-29T23:59:59.000Z

322

High Gradient Inverse Free Electron Laser (IFEL) Accelerator  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickr FlickrGuidedCH2M HILLAdministration | National|Gradient High

323

Exploring the effect of Al2O3 ALD coating on a high gradient ILC single-cell cavity  

SciTech Connect (OSTI)

Encouraged by work at Argonne National Lab, we investigated atomic layer deposition technique (ALD) for high gradient superconducting RF cavities at JLab with an ALD coating system of Old Dominion University located on the JLab site. The goal of this study was to look into the possibility of coating a dielectric layer on top of RF niobium surface at a lower temperature of 120 C as compared to ANL coatings at 200 C to preserve niobium pentoxide on niobium surface. The initial coatings showed complete, but non-uniform coatings of the surface with several areas exhibiting discoloration, which was probably due to the temperature variation across the cavity surface. The initial coating showed a high RF losses, which were improved after discolored areas on the beam tubes were removed with HF rinse of the beam tubes only. The best result was 2 109 low field Q0 and Eacc = 18 MV/m limited by available power.

Grigory Eremeev, Anne-Marie Valente, Andy Wu, Diefeng Gu

2012-07-01T23:59:59.000Z

324

Opacity and gradients in aluminum wire array z-pinch implosions on the Z pulsed power facility  

SciTech Connect (OSTI)

Aluminum wire array z pinches imploded on the Z generator are an extremely bright source of 1–2?keV radiation, with close to 400?kJ radiated at photon energies >1?keV and more than 50?kJ radiated in a single line (Al Ly-?). Opacity plays a critical role in the dynamics and K-shell radiation efficiency of these pinches. Where significant structure is present in the stagnated pinch this acts to reduce the effective opacity of the system as demonstrated by direct analysis of spectra. Analysis of time-integrated broadband spectra (0.8–25?keV) indicates electron temperatures ranging from a few 100?eV to a few keV are present, indicative of substantial temperature gradients.

Ampleford, D. J., E-mail: damplef@sandia.gov; Hansen, S. B.; Jennings, C. A.; Jones, B.; Coverdale, C. A.; Harvey-Thompson, A. J.; Rochau, G. A.; Dunham, G.; Moore, N. W.; Harding, E. C.; Cuneo, M. E. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Chong, Y.-K.; Clark, R. W.; Ouart, N.; Thornhill, J. W.; Giuliani, J.; Apruzese, J. P. [Naval Research Laboratory, Washington, DC 20375 (United States)] [Naval Research Laboratory, Washington, DC 20375 (United States)

2014-03-15T23:59:59.000Z

325

Ultra-High Gradient Dielectric Wakefield Accelerator Experiments  

SciTech Connect (OSTI)

Ultra-high gradient dielectric wakefield accelerators are a potential option for a linear collider afterburner since they are immune to the ion collapse and electron/positron asymmetry problems implicit in a plasma based afterburner. The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. The experiment took advantage of the unique SLAC FFTB electron beam and its ultra-short pulse lengths and high currents (e.g., {sigma}{sub z} = 20 {micro}m at Q = 3 nC). The FFTB electron beam was successfully focused down and sent through short lengths of fused silica capillary tubing (ID = 200 {micro}m/OD = 325 {micro}m). The pulse length of the electron beam was varied to produce a range of electric fields between 2 and 20 GV/m at the inner surface of the dielectric tubes. We observed a sharp increase in optical emissions from the capillaries in the middle part of this surface field range which we believe indicates the transition between sustainable field levels and breakdown. If this initial interpretation is correct, the surfaced fields that were sustained equate to on axis accelerating field of several GV/m. In future experiments being developed for the SLAC SABER and BNL ATF we plan to use the coherent Cerenkov radiation emitted from the capillary tube as a field strength diagnostic and demonstrate GV/m range particle energy gain.

Thompson, M C; Badakov, H; Rosenzweig, J B; Travish, G; Hogan, M; Ischebeck, R; Kirby, N; Siemann, R; Walz, D; Muggli, P; Scott, A; Yoder, R

2006-08-04T23:59:59.000Z

326

Ultra-High Gradient Dielectric Wakefield Accelerator Experiments  

SciTech Connect (OSTI)

Ultra-high gradient dielectric wakefield accelerators are a potential option for a linear collider afterburner since they are immune to the ion collapse and electron/positron asymmetry problems implicit in a plasma based afterburner. The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. The experiment took advantage of the unique SLAC FFTB electron beam and its ultra-short pulse lengths and high currents (e.g., {sigma}z = 20 {mu}m at Q = 3 nC). The FFTB electron beam was successfully focused down and sent through short lengths of fused silica capillary tubing (ID = 200 {mu}m / OD = 325 {mu}m). The pulse length of the electron beam was varied to produce a range of electric fields between 2 and 20 GV/m at the inner surface of the dielectric tubes. We observed a sharp increase in optical emissions from the capillaries in the middle part of this surface field range which we believe indicates the transition between sustainable field levels and breakdown. If this initial interpretation is correct, the surfaced fields that were sustained equate to on axis accelerating field of several GV/m. In future experiments being developed for the SLAC SABER and BNL ATF we plan to use the coherent Cerenkov radiation emitted from the capillary tube as a field strength diagnostic and demonstrate GV/m range particle energy gain.

Thompson, M. C. [Lawrence Livermore National Laboratory, Livermore, California, 90095 (United States); Badakov, H.; Rosenzweig, J. B.; Travis, G. [UCLA Department of Physics and Astronomy, Los Angeles, California, 90095 (United States); Hogan, M.; Ischebeck, R.; Kirby, N.; Siemann, R.; Walz, D. [Stanford Linear Accelerator Center, Stanford, California, 94309 (United States); Muggli, P. [University of Southern California Los Angeles, California, 90089 (United States); Scott, A. [UCSB Department of Physics, Santa Barbara, California, 93106 (United States); Yoder, R. [Manhattan College, Riverdale, New York, 10471 (United States)

2006-11-27T23:59:59.000Z

327

Analytic energy gradients for constrained DFT-configuration interaction  

SciTech Connect (OSTI)

The constrained density functional theory-configuration interaction (CDFT-CI) method has previously been used to calculate ground-state energies and barrier heights, and to describe electronic excited states, in particular conical intersections. However, the method has been limited to evaluating the electronic energy at just a single nuclear configuration, with the gradient of the energy being available only via finite difference. In this paper, we present analytic gradients of the CDFT-CI energy with respect to nuclear coordinates, which gives the potential for accurate geometry optimization and molecular dynamics on both the ground and excited electronic states, a realm which is currently quite challenging for electronic structure theory. We report the performance of CDFT-CI geometry optimization for representative reaction transition states as well as molecules in an excited state. The overall accuracy of CDFT-CI for computing barrier heights is essentially unchanged whether the energies are evaluated at geometries obtained from quadratic configuration-interaction singles and doubles (QCISD) or CDFT-CI, indicating that CDFT-CI produces very good reaction transition states. These results open up tantalizing possibilities for future work on excited states.

Kaduk, Benjamin; Tsuchimochi, Takashi; Van Voorhis, Troy, E-mail: tvan@mit.edu [Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States)

2014-05-14T23:59:59.000Z

328

Feedback Mechanism for Microtubule Length Regulation by Stathmin Gradients  

E-Print Network [OSTI]

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.

Maria Zeitz; Jan Kierfeld

2014-12-09T23:59:59.000Z

329

Dielectric-Lined High-Gradient Accelerator Structure  

SciTech Connect (OSTI)

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.

Jay L. Hirshfield

2012-04-24T23:59:59.000Z

330

Optimization of the Oktay-Kronfeld Action Conjugate Gradient Inverter  

E-Print Network [OSTI]

Improving the Fermilab action to third order in heavy quark effective theory yields the Oktay-Kronfeld action, a promising candidate for precise calculations of the spectra of heavy quark systems and weak matrix elements relevant to searches for new physics. We have optimized the bi-stabilized conjugate gradient inverter in the SciDAC QOPQDP library and are developing a GPU code. The action is rewritten and the needed gauge-link combinations are precalculated. In tests with a MILC coarse lattice, this procedure accelerates the inverter by a factor of four. The remaining floating-point operations are mostly simple matrix multiplications between gauge links and fermion vectors, which we accelerate by more than an order of magnitude by using CUDA. Further gains could be achieved by using QUDA.

Yong-Chull Jang; Jon A. Bailey; Weonjong Lee; Carleton DeTar; Mehmet B. Oktay; Andreas S. Kronfeld

2013-11-21T23:59:59.000Z

331

Modified Magnicon for High-Gradient Accelerator R&D  

SciTech Connect (OSTI)

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.

Jay L. Hirshfield

2011-12-19T23:59:59.000Z

332

Ducted kinetic Alfven waves in plasma with steep density gradients  

SciTech Connect (OSTI)

Given their high plasma density (n {approx} 10{sup 13} cm{sup -3}), it is theoretically possible to excite Alfven waves in a conventional, moderate length (L {approx} 2 m) helicon plasma source. However, helicon plasmas are decidedly inhomogeneous, having a steep radial density gradient, and typically have a significant background neutral pressure. The inhomogeneity introduces regions of kinetic and inertial Alfven wave propagation. Ion-neutral and electron-neutral collisions alter the Alfven wave dispersion characteristics. Here, we present the measurements of propagating kinetic Alfven waves in helium helicon plasma. The measured wave dispersion is well fit with a kinetic model that includes the effects of ion-neutral damping and that assumes the high density plasma core defines the radial extent of the wave propagation region. The measured wave amplitude versus plasma radius is consistent with the pile up of wave magnetic energy at the boundary between the kinetic and inertial regime regions.

Houshmandyar, Saeid [Solar Observatory Department, Prairie View A and M University, Prairie View, Texas 77446 (United States); Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States); Scime, Earl E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States)

2011-11-15T23:59:59.000Z

333

Sources of stress gradients in electrodeposited Ni MEMS.  

SciTech Connect (OSTI)

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.

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

2004-06-01T23:59:59.000Z

334

On the equivalence of the method of conjugate gradients and quasi ...  

E-Print Network [OSTI]

Mar 9, 2015 ... We show that the set of quasi-Newton schemes that generate parallel search directions to those of the method of conjugate gradients is strictly ...

Anders Forsgren

2015-03-09T23:59:59.000Z

335

On the behavior of the conjugate-gradient method on ill-conditioned ...  

E-Print Network [OSTI]

Jan 9, 2006 ... Abstract: We study the behavior of the conjugate-gradient method for solving a set of linear equations, where the matrix is symmetric and ...

Anders Forsgren

2006-01-09T23:59:59.000Z

336

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

Open Energy Info (EERE)

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

337

E-Print Network 3.0 - alternating gradient ffag Sample Search...  

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

Upton, NY, USA Summary: of interest in the use of fixed field alternating gradient accelerators (FFAGs) for many applications... expensive, so an FFAG is an attractive alternative...

338

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

SciTech Connect (OSTI)

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.

Bosch, Robert [SRC U. Wisconsin-Madison; Legg, Robert A. [JLAB

2013-12-01T23:59:59.000Z

339

E-Print Network 3.0 - azimuthal color gradients Sample Search...  

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

of Hurricane Summary: inward advection of angular momentum past the point of gradient wind balance results in an azimuthal... inflow and a stronger azimuthal wind maximum at...

340

E-Print Network 3.0 - african latitudinal gradient Sample Search...  

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

annurev.ecolsys.34.012103.144032 Summary: on July 11, 2003 LATITUDINAL GRADIENTS OF BIODIVERSITY: Pattern, Process, Scale, and Synthesis M.R. Willig... , biogeography s Abstract...

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


341

Computer program to analyze multipass pressure-temperature-spinner surveys  

SciTech Connect (OSTI)

A computer program has been developed to analyze multipass pressure-temperature-spinner surveys and summarize the data in graphical form on two plots: (1) an overlay of spinner passes along with a fluid velocity profile calculated from the spinner and (2) an overlay of pressure, pressure gradient, and temperature profiles from each pass. The program has been written using SmartWare II Software. Fluid velocity is calculated for each data point using a cross-plot of tool speed and spinner counts to account for changing flow conditions in the wellbore. The program has been used successfully to analyze spinner surveys run in geothermal wells with two-phase flashing flow.

Spielman, Paul

1994-01-20T23:59:59.000Z

342

Gradient-based optimization of mother wavelets Nicola Neretti Nathan Intrator  

E-Print Network [OSTI]

. We develop an unconstrained gradient-based optimization algorithm for a discrete wavelet transform wavelet transforms. In is paper we describe a novel optimization for the pur- pose of wavelet filter1 Gradient-based optimization of mother wavelets Nicola Neretti Nathan Intrator Abstract-- We

Intrator, Nathan

343

Deformation-induced inverted metamorphic eld gradients: an example from the southeastern Canadian Cordillera  

E-Print Network [OSTI]

Deformation-induced inverted metamorphic ®eld gradients: an example from the southeastern Canadian allochthon and Monashee complex, exhibits an inverted metamorphic ®eld gradient. New data presented preserving evidence of strongly diachronous deformation and an apparent inverted metamorphism. # 1999

Gibson, Dan

344

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

E-Print Network [OSTI]

Offshore Coastal Wind Speed Gradients: issues for the design and development of large offshore@globalnet.co.uk · WEB SITE: www.multi-science.co.uk #12;Offshore Coastal Wind Speed Gradients: issues for the design and development of large offshore windfarms R.J. Barthelmie1,2, J. Badger3, S.C. Pryor2, C.B. Hasager3, M

Pryor, Sara C.

345

Integrated thermal-microstructure model to predict the property gradients in resistance spot steel welds  

SciTech Connect (OSTI)

An integrated model approach was proposed for relating resistance welding parameters to weldment properties. An existing microstructure model was used to determine the microstructural and property gradients in resistance spot welds of plain carbon steel. The effect of these gradients on the weld integrity was evaluated with finite element analysis. Further modifications to this integrated thermal-microstructure model are discussed.

Babu, S.S.; Riemer, B.W.; Santella, M.L. [Oak Ridge National Lab., TN (United States); Feng, Z. [Edison Welding Inst., Columbus, OH (United States)

1998-11-01T23:59:59.000Z

346

Effects of pressure gradient on global Alfvén eigenmodes in reversed field pinch  

SciTech Connect (OSTI)

The effects of pressure gradient on the existence of global Alfvén eigenmodes (GAE) in Reversed Field Pinch are studied by numerical calculation. It is found that GAEs near the plasma core can exist when pressure gradient is sufficiently large. The calculated mode frequency and structure are consistent with the experimental results in the Madison Symmetric Torus.

Cai, Huishan, E-mail: hscai@mail.ustc.edu.cn [CAS Key Laboratory of Geospace Environment, Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China)] [CAS Key Laboratory of Geospace Environment, Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China); Fu, Guoyong, E-mail: fu@pppl.gov [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Lin, Liang; Ding, Weixing; Brower, D. L. [Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095 (United States)] [Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095 (United States); Liu, D. Y. [Physics Department, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)] [Physics Department, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Hu, Y. J. [Institute of Plasma Physics, CAS (China)] [Institute of Plasma Physics, CAS (China)

2014-02-15T23:59:59.000Z

347

Quantification of the electrochemical proton gradient and activation of ATP synthase in leaves  

E-Print Network [OSTI]

Quantification of the electrochemical proton gradient and activation of ATP synthase in leaves Available online 12 April 2008 Keywords: ATP synthase Electrochemical proton gradient Membrane potential We of the ATP synthase (Junge, W., Rumberg, B. and Schröder, H., Eur. J. Biochem. 14 (1970) 575

348

Sediment Respiration and Nitrogen Cycling along a Eutrophic Gradient in a Shallow, Coastal Estuary  

E-Print Network [OSTI]

Sediment Respiration and Nitrogen Cycling along a Eutrophic Gradient in a Shallow, Coastal Estuary Respiration and Nitrogen Cycling along a Eutrophic Gradient in a Shallow, Coastal Estuary Semester and denitrification potentials. We found that the more eutrophic sites had higher respiration and ammonification. Our

Vallino, Joseph J.

349

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

E-Print Network [OSTI]

ENERGY SCAVENGING BASED ON TRANSIENT THERMAL GRADIENTS: APPLICATION TO STRUCTURAL HEALTH MONITORING from its environment [2]. A possible source of energy could be thermal gradients. This paper, INSA 3 Thalès Alenia Space, Toulouse, France Abstract: Results about energy capture from

Paris-Sud XI, Université de

350

Ultra-High Gradient Compact S-Band Linac for Laboratory and Industrial Applications  

SciTech Connect (OSTI)

There is growing demand from the industrial and research communities for high gradient, compact RF accelerating structures. The commonly used S-band SLAC-type structure has an operating gradient of only about 20 MV/m; while much higher operating gradients (up to 70 MV/m) have been recently achieved in X-band, as a consequence of the substantial efforts by the Next Linear Collider (NLC) collaboration to push the performance envelope of RF structures towards higher accelerating gradients. Currently however, high power X-band RF sources are not readily available for industrial applications. Therefore, RadiaBeam Technologies is developing a short, standing wave S-band structure which uses frequency scaled NLC design concepts to achieve up to a 50 MV/m operating gradient at 2856 MHz. The design and prototype commissioning plans are presented.

Faillace, Luigi; /RadiaBeam Tech.; Agustsson, Ronald; /RadiaBeam Tech.; Frigola, Pedro; /RadiaBeam Tech.; Murokh, Alex; /RadiaBeam Tech.; Dolgashev, Valery; /SLAC; Rosenzweig, James; /UCLA

2012-07-03T23:59:59.000Z

351

Gradient flow and scale setting on MILC HISQ ensembles  

E-Print Network [OSTI]

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...

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

2015-01-01T23:59:59.000Z

352

Structural Evolution and Li Dynamics in Nanophase Li3PS4 by Solid-State and Pulsed Field Gradient NMR  

SciTech Connect (OSTI)

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.

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

2014-01-01T23:59:59.000Z

353

Analysis of Gradient-Based Routing Protocols in Sensor Networks  

E-Print Network [OSTI]

Sensor networks are envisioned to be widely used for habitat and environmental monitoring where, etc. Every physical event leaves some fingerprints in the environment in terms of the event's effect; e.g., fire increases the temperature, chemical spilling increases the contamination, nuclear leakage

354

Lithologic descriptions and temperature profiles of five wells in the southwestern Valles caldera region, New Mexico  

SciTech Connect (OSTI)

The subsurface stratigraphy and temperature profiles of the southern and western Valles caldera region have been well constrained with the use of data from the VC-1, AET-4, WC 23-4, PC-1 and PC-2 wells. Data from these wells indicate that thermal gradients west of the caldera margin are between 110 and 140)degrees)C/km, with a maximum gradient occurring in the bottom of PC-1 equal to 240)degrees)C/km as a result of thermal fluid flow. Gradients within the caldera reach a maximum of 350)degrees)C/km, while the maximum thermal gradient measured southwest of the caldera in the thermal outflow plume is 140)degrees)C/km. The five wells exhibit high thermal gradients (>60)deghrees)C/km) resulting from high conductive heat flow associated with the Rio Grande rift and volcanism in the Valles caldera, as well as high convective heat flow associated with circulating geothermal fluids. Gamma logs run in four of the five wells appear to be of limited use for stratigraphic correlations in the caldera region. However, stratigraphic and temperature data from the five wells provide information about the structure and thermal regime of the southern and western Valles caldera region. 29 refs., 9 figs. 2 tabs.

Shevenell, L.; Goff, F.; Miles, D.; Waibel, A.; Swanberg, C.

1988-01-01T23:59:59.000Z

355

Digital Manufacturing of Gradient Meshed SOFC Sealing Composites with Self-Healing Capabilities  

SciTech Connect (OSTI)

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.

Kathy Lu; Christopher Story; W.T. Reynolds

2007-12-21T23:59:59.000Z

356

Influence of the Coast and Vegetation on Temperature Gradients across the Los Angeles Basin using Mobile Transect Techniques  

E-Print Network [OSTI]

SURFACES AND SHADE TREES TO REDUCE ENERGY USE AND IMPROVEInfluence of tree cover on summertime surface energy balance19% more energy was measured over an area with 30% tree and

Lee, Audrey

2012-01-01T23:59:59.000Z

357

Influence of the Coast and Vegetation on Temperature Gradients across the Los Angeles Basin using Mobile Transect Techniques  

E-Print Network [OSTI]

from sensible heat flux. Remote Sensing of Environment, 99(heat island study in winter by mobile transect and remote

Lee, Audrey

2012-01-01T23:59:59.000Z

358

Temperature Fluctuation and an Expected Limit of Hubble Parameter in the Self-Consistent Model  

E-Print Network [OSTI]

The temperature gradient of microwave background radiation (CMBR) is calculated in the Self Consistent Model. An expected values for Hubble parameter have been presented in two different cases. In the first case the temperature is treated as a function of time only, while in the other one the temperature depends on relaxation of isotropy condition in the self-consistent model and the assumption that the universe expands adiabatically. The COBE's or WMAP's fluctuations in temperature of CMBR may be used to predict a value for Hubble parameter.

A. B. Morcos

2004-12-08T23:59:59.000Z

359

Strings at finite temperature  

SciTech Connect (OSTI)

We obtain a semiclassical evaluation of the temperature for which the free energy of the strings of spontaneously broken scalar electrodynamics vanishes. We argue that, above this temperature, these objects should play a significant physical role.

Arago C. de; Bazeia, D.; Eboli, O.J.P.; Marques, G.C.

1985-12-15T23:59:59.000Z

360

Design of diamond turned holograms by the nonlinear conjugate gradients method Colin Dankwart, Claas Falldorf and Jurgen Jahns  

E-Print Network [OSTI]

Design of diamond turned holograms by the nonlinear conjugate gradients method Colin Dankwart investigate a different optimization approach, the nonlinear conjugate gradients (NCG) method. The NGC method design algorithm, based on the generalized projections method (GPM) [?] was established, taking

Jahns, Jürgen

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


361

6, 13011320, 2006 Temperature  

E-Print Network [OSTI]

ACPD 6, 1301­1320, 2006 Temperature climatology and trend estimates over Durban, South Africa H and Physics Discussions Temperature climatology and trend estimates in the UTLS region as observed over Commons License. 1301 #12;ACPD 6, 1301­1320, 2006 Temperature climatology and trend estimates over Durban

Boyer, Edmond

362

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

E-Print Network [OSTI]

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

Patrizio Neff; Dirk Pauly; Karl-Josef Witsch

2011-06-30T23:59:59.000Z

363

JOURNAL OF OPTIMIZATION THEORY AND APPLICATIONS: Vol. 66, No. 1, JULY 1990 Vectorization of Conjugate-Gradient Methods  

E-Print Network [OSTI]

of Conjugate-Gradient Methods for Large-Scale Minimization in Meteorology' Io M. NAVON, 2 P. K. H. PHUA, 3 conjugate-gradient methods designed to solve symmetric linear systems of algebraic equations, arising mainly or parallel processing, no such effort was undertaken for the nonlinear conjugate-gradient method for large

Navon, Michael

364

Trace-element geochemistry of gradient hole cuttings: Beowawe geothermal area, Nevada  

SciTech Connect (OSTI)

Multielement geochemical analysis of drill cuttings from 26 shallow temperature-gradient drill holes and of surface rock samples reveals trace element distributions developed within these rocks as a consequence of chemical interaction with thermal fluid within the Beowawe geothermal area. The presently discharging thermal fluids are dilute in all components except silica, suggesting that the residence time of these fluids within the thermal reservoir has been short and that chemical interaction with the reservoir rock minimal. Interaction between these dilute fluids and rocks within the system has resulted in the development of weak chemical signatures. The absence of stronger signatures in rocks associated with the present system suggests that fluids have had a similar dilute chemistry for some time. The spatial distribution of elements commonly associated with geothermal systems, such as As, Hg and Li, and neither laterally nor vertically continuous. This suggests that there is not now, nor has there been in the past, pervasive movement of thermal fluid throughout the sampled rock but, instead, that isolated chemical anomalies represent distinct fluid-flow chanels. Discontinuous As, Li and Hg concentrations near White Canyon to the east of the presently active surface features record the effects of chemical interaction of rocks with fluids chemically unlike the presently discharging fluids. The observed trace element distributions suggest that historically the Beowawe area has been the center of more than one hydrothermal event and that the near-surface portion of the present hot-water geothermal system is controlled by a single source fracture, the Malpais Fault, or an intersection of faults at the sinter terrace.

Christensen, O.D.

1980-12-01T23:59:59.000Z

365

Temperature compensated photovoltaic array  

DOE Patents [OSTI]

A temperature compensated photovoltaic module comprises a series of solar cells having a thermally activated switch connected in parallel with several of the cells. The photovoltaic module is adapted to charge conventional batteries having a temperature coefficient differing from the temperature coefficient of the module. The calibration temperatures of the switches are chosen whereby the colder the ambient temperature for the module, the more switches that are on and form a closed circuit to short the associated solar cells. By shorting some of the solar cells as the ambient temperature decreases, the battery being charged by the module is not excessively overcharged at lower temperatures. PV module is an integrated solution that is reliable and inexpensive. 2 figs.

Mosher, D.M.

1997-11-18T23:59:59.000Z

366

Temperature compensated photovoltaic array  

DOE Patents [OSTI]

A temperature compensated photovoltaic module (20) comprised of a series of solar cells (22) having a thermally activated switch (24) connected in parallel with several of the cells (22). The photovoltaic module (20) is adapted to charge conventional batteries having a temperature coefficient (TC) differing from the temperature coefficient (TC) of the module (20). The calibration temperatures of the switches (24) are chosen whereby the colder the ambient temperature for the module (20), the more switches that are on and form a closed circuit to short the associated solar cells (22). By shorting some of the solar cells (22) as the ambient temperature decreases, the battery being charged by the module (20) is not excessively overcharged at lower temperatures. PV module (20) is an integrated solution that is reliable and inexpensive.

Mosher, Dan Michael (Plano, TX)

1997-11-18T23:59:59.000Z

367

Low Frequency Modulation of Extreme Temperature Regimes in a Changing Climate  

SciTech Connect (OSTI)

The project examines long-term changes in extreme temperature episodes (ETE) associated with planetary climate modes (PCMs) in both the real atmospheric and climate model simulations. The focus is on cold air outbreaks (CAOs) and warm waves (WWs) occurring over the continental US during the past 60 winters. No significant long-term trends in either WWs or CAOs are observed over the US. The annual frequency of CAOs is affected by the (i) North Atlantic Oscillation (NAO) over the Southeast US and (ii) Pacific–North American (PNA) pattern over the Northwest US. WW frequency is influenced by the (i) NAO over the eastern US and (ii) combined influence of PNA, Pacific decadal oscillation (PDO), and ENSO over the southern US. The collective influence of PCMs accounts for as much as 50% of the regional variability in ETE frequency. During CAO (WW) events occurring over the southeast US, there are low (high) pressure anomalies at higher atmospheric levels over the southeast US with oppositely-signed pressure anomalies in the lower atmosphere over the central US. These patterns lead to anomalous northerly (for CAOs) or southerly (for WWs) flow into the southeast leading to cold or warm surface air temperature anomalies, respectively. One distinction is that CAOs involve substantial air mass transport while WW formation is more local in nature. The primary differences among event categories are in the origin and nature of the pressure anomaly features linked to ETE onset. In some cases, PCMs help to provide a favorable environment for event onset. Heat budget analyses indicate that latitudinal transport in the lower atmosphere is the main contributor to regional cooling during CAO onset. This is partly offset by adiabatic warming associated with subsiding air. Additional diagnoses reveal that this latitudinal transport is partly due to the remote physical influence of a shallow cold pool of air trapped along the east side of the Rocky Mountains. ETE and PCM behavior is also studied in (CMIP5) climate model simulations. Although the climate models considered are able to represent the overall behavior of ETEs, the frequency of WWs (CAOs) is too high (low) in many models. While all models qualitatively replicate the overall structure of the PNA pattern, a small minority of models fails to properly simulate the NAO pattern. Model shortcomings in representing the NAO and PNA patterns have important consequences for simulating associated regional variability in surface air temperature and storm track behavior. The influence of PCMs on ETEs is underestimated in most CMIP5 models. In particular, none of the models are able to accurately simulate observed linkages between ETEs and the PDO, due to a gross misrepresentation of the PDO pattern in most models. Our results indicate that predictions of future CAO and WW behavior are currently limited by the ability of climate models to accurately represent PCM characteristics. Our study also considers the behavior of PCMs known as annular modes. It is determined that north-south movements in the stratospheric jet stream (related to the Polar Annular Mode) result in long-lasting impacts upon surface weather conditions including regional air temperature anomalies. The structure and dynamics of the stratospheric northern annular mode (or SNAM, related to changes in the strength of the stratospheric jet stream) was studied in CMIP5 models. In models with poorly-resolved stratospheres, the amplitude of SNAM at stratospheric altitudes is typically too weak, consistent with weaker stratospheric jet variability. However, this distinction does not carry over to the associated tropospheric signature of SNAM. A regional analysis illustrates that most CMIP5 models (regardless of whether the stratosphere is well-resolved) have anomalously weak and eastward shifted (compared to observed SNAM events) storm track and sea level pressure anomaly patterns during SNAM events. Analyses of stratosphere–troposphere coupling reveal that large-scale wave activity in the stratosphere is anomalously weak in CMIP5 model

Black, Robert X.

2014-11-24T23:59:59.000Z

368

Toward Understanding and Modeling Compressibility Effects on Velocity Gradients in Turbulence  

E-Print Network [OSTI]

gradients hold the key to understanding several non-linear processes like material element deformation, energy cascading, intermittency and mixing. Experiments, direct numerical simulation (DNS) and simple mathematical models are three approaches to study...

Suman, Sawan

2011-02-22T23:59:59.000Z

369

Uncertainty Quantification in Viscous Hypersonic Flows using Gradient Information and Surrogate  

E-Print Network [OSTI]

Uncertainty Quantification in Viscous Hypersonic Flows using Gradient Information and Surrogate models for the purposes of uncertainty quantification within the context of viscous hypersonic flows quantification in hypersonic flows. I. Introduction and Motivation The increasing reliance on numerical

Rumpfkeil, Markus Peer

370

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

E-Print Network [OSTI]

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...

Bosshard, John 1983-

2012-08-20T23:59:59.000Z

371

One dimensional electron spin imaging for single spin detection and manipulation using a gradient field  

E-Print Network [OSTI]

magnetic field gradients. These fabricated devices are used to demonstrate this subwavelength imaging technique by imaging single electron spins of the nitrogen-vacancy (NV) defect in diamond. In this demonstration, multiple NV defects, unresolved in a...

Shin, Chang-Seok

2009-05-15T23:59:59.000Z

372

Bell-Plesset effects for an accelerating interface with contiguous density gradients  

SciTech Connect (OSTI)

A Plesset-type treatment [J. Appl. Phys. 25, 96 (1954)] is used to assess the effects of contiguous density gradients at an accelerating spherical classical interface on Rayleigh-Taylor and Bell-Plesset perturbation growth. Analytic expressions are obtained that describe enhanced Rayleigh-Taylor instability growth from contiguous density gradients aligned with the acceleration and which increase the effective Atwood number of the perturbed interface. A new pathway for geometric amplification of surface perturbations on an accelerating interface with contiguous density gradients is identified. A resonance condition between the density-gradient scalelength and the radius of the interface is also predicted based on a linearized analysis of Bernoulli's equation, potentially leading to enhanced perturbation growth. Comparison of the analytic treatment with detailed two-dimensional single-mode growth-factor simulations shows good agreement for low-mode numbers where the effects of spherical geometry are most manifested.

Amendt, P

2005-12-20T23:59:59.000Z

373

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

E-Print Network [OSTI]

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 ...

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

2013-01-01T23:59:59.000Z

374

Studies of the superconducting traveling wave cavity for high gradient LINAC  

E-Print Network [OSTI]

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.

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

2015-01-01T23:59:59.000Z

375

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

SciTech Connect (OSTI)

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.

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)

2010-11-04T23:59:59.000Z

376

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

E-Print Network [OSTI]

gradient volume (height) on stallion sperm quality and recovery rate in sperm pellets following centrifugation. In all three experiments, equine semen was initially centrifuged to increase sperm concentration. In Experiment 1, one-mL aliquots were layered...

Edmond, Ann J.

2010-07-14T23:59:59.000Z

377

The effect of periodic-unsteady wakes, curvature, and pressure gradient on boundary-layer transition  

E-Print Network [OSTI]

Boundary-layer transition on a concave curved plate has been investigated with and without periodic-unsteady inlet flow at zero and negative pressure gradients. The periodicunsteady wakes were created using a rotating squirrel-cage type wake...

Radke, Robert Edward

1994-01-01T23:59:59.000Z

378

Poblano v1.0 : a Matlab toolbox for gradient-based optimization.  

SciTech Connect (OSTI)

We present Poblano v1.0, a Matlab toolbox for solving gradient-based unconstrained optimization problems. Poblano implements three optimization methods (nonlinear conjugate gradients, limited-memory BFGS, and truncated Newton) that require only first order derivative information. In this paper, we describe the Poblano methods, provide numerous examples on how to use Poblano, and present results of Poblano used in solving problems from a standard test collection of unconstrained optimization problems.

Dunlavy, Daniel M.; Acar, Evrim (Sandia National Laboratories, Livermore, CA); Kolda, Tamara Gibson (Sandia National Laboratories, Livermore, CA)

2010-03-01T23:59:59.000Z

379

Double active shielded magnetic field gradient design with minimum inductance method  

E-Print Network [OSTI]

DOUBLE ACTIVE SHIELDED MAGNETIC FIELD GRADIENT DESIGN WITH MINIMUM INDUCTANCE METHOD A Thesis by XU WANG Submitted to the Oflice of Graduate Studies of Texas ASM University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE May 1992 Major Subject: Physics DOUBLE ACTIVE SHIELDED MAGNETIC FIELD GRADIENT DESIGN WITH MINIMUM INDUCTANCE METHOD A Thesis by XU WANG Approved as to style and content by: F. R. Huson (Chair of Committee) Steve Wry (Member) Edward...

Wang, Xu

1992-01-01T23:59:59.000Z

380

High gradient magnetic separation of iron oxide minerals from soil clays  

E-Print Network [OSTI]

HIGH GRADIENT MAGNETIC SEPARATION OF IRON OXIDE MINERALS FROM SOIL CLAYS A Thesis by DARRELL GENE SCHULZE Submitted to the Graduate College of Texas AIM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE... December 1977 Major Subject: Soil Science HIGH GRADIENT MAGNETIC SEPARATION OF IRON OXIDE MINERALS FROM SOIL CLAYS A Thesis DARRELL GENE SCHULZE Approved as to style and content by: (Chairman of C ittee) epartm t) j (Member) (Membe December 1977...

Schulze, Darrell Gene

1977-01-01T23:59:59.000Z

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


381

MILLIMETER-SCALE GENETIC GRADIENTS AND COMMUNITY-LEVEL MOLECULAR CONVERGENCE IN A HYPERSALINE MICROBIAL MAT  

SciTech Connect (OSTI)

To investigate the extent of genetic stratification in structured microbial communities, we compared the metagenomes of 10 successive layers of a phylogenetically complex hypersaline mat from Guerrero Negro, Mexico. We found pronounced millimeter-scale genetic gradients that are consistent with the physicochemical profile of the mat. Despite these gradients, all layers displayed near identical and acid-shifted isoelectric point profiles due to a molecular convergence of amino acid usage indicating that hypersalinity enforces an overriding selective pressure on the mat community.

Fenner, Marsha W; Kunin, Victor; Raes, Jeroen; Harris, J. Kirk; Spear, John R.; Walker, Jeffrey J.; Ivanova, Natalia; Mering, Christian von; Bebout, Brad M.; Pace, Norman R.; Bork, Peer; Hugenholtz, Philip

2008-04-30T23:59:59.000Z

382

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

E-Print Network [OSTI]

Integral Parameters . 4. 2 Law of the Wall Profiles 4. 3 Pressure Gradient Parameters 4. 4 Preston Tube Measurements 4. 5 Roughness Function 4. 6 Growth of the Internal Layer 4. 7 Turbulence Measurements 4. 7. 1 Turbulence intensity 4. 7. 2 Third.... 4 Spectra for favorable pressure gradient 4. 8. 5 Roughness effects on the bursting process V CONCLUSION . REFERENCES APPENDIX A APPENDIX B 50 50 51 94 134 175 177 180 183 . . 185 VITA . . 210 LIST OF FIGURES Figure 1. Proportions...

Hall, Aaron Chenault

1991-01-01T23:59:59.000Z

383

Influence of surface heating on the boundary layer stability of flows with favorable pressure gradients  

E-Print Network [OSTI]

INFLUENCE OF SURFACE HEATING ON THE BOUNDARY LAYER STABILITY OF FLOWS WITH FAVORABI E PRESSURE GRADIENTS A Thesis by DAVID BRIAN LANDRUM Submitted to the Graduate College of Texas AAM University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE August 1986 Major Subject: Aerospace Engineering INFLUENCE OF SURFACE HEATING ON THE BOUNDARY LAYER STABILITY OF FLOWS WITH FAVORABLE PRESSURE GRADIENTS A Thesis by DAVID BRIAN LANDRUM Approved as to style and content...

Landrum, David Brian

2012-06-07T23:59:59.000Z

384

Stellar Population Gradients in Bulges along the Hubble Sequence: II. Relations with Galaxy Properties  

E-Print Network [OSTI]

We present the analysis of the radial gradients of stellar absorption lines in a sample of 32 bulges of edge-on spiral galaxies, spanning nearly the full Hubble sequence (from S0 to Sc types), and a large range of velocity dispersion (from about 60 to 300 km/s). Different diagnostics such as index-index, gradient-gradient diagrams, and simple stellar population models are used to tackle the origin of the variation of the bulge stellar population. We find that the vast majority of bulges show older age, lower metallicity and higher [alpha/Fe] in their outer regions than in their central parts. The radial gradients in [Fe/H] are 2 to 3 times larger than in Log(age). The relation between gradient and bulge velocity dispersion is interpreted as a gradual build up of the gradient mean values and their dispersions from high to low velocity dispersion, rather than a pure correlation. The bulge effective radii and the Hubble type of the parent galaxies seem to play a more minor role in causing the observed spatial distributions. At a given velocity dispersion, bulges and ellipticals share common properties.

P. Jablonka; J. Gorgas; P. Goudfrooij

2007-07-04T23:59:59.000Z

385

Novel concepts in weld metal science: Role of gradients and composite structure  

SciTech Connect (OSTI)

The effects of compositional and microstructural gradients on weld metal properties are being investigated. Crack propagation is solidified alloy structures is being characterized as to solidification orientation and the profile of the compositional variations. The effects of compositional gradients, are considered based on a thermodynamic analysis, referred to as the Cahn-Hillard analysis, which describes the degree to which a local surface energy is modified by the presence of a compositional gradient. The analysis predicts that both ductile and brittle fracture mechanisms are enhanced by the presence of a composition gradient. Special techniques to produce laboratory samples with microstructures which simulate the composition and microstructure gradients in solidified weld metal are used, along with appropriate mathematical models, to evaluate the properties of the composite weld metals. The composite modeling techniques are being applied to describe the effects of compositional and microstructural gradients on weld metal properties in Ni-Cu alloys. The development of metal matrix composition weld deposits on austenitic stainless steels has been studied. The particulate metal matrix composites were produced with ceramic or refractory metal powder filled cored wire, which was gas tungsten arc and gas metal arc welded.

Matlock, D.K.; Olson, D.L.

1991-12-01T23:59:59.000Z

386

Role of Ash Deposits in the High Temperature Corrosion of Boiler Tubes  

SciTech Connect (OSTI)

Ash deposits cause accelerated corrosion of waterwall boiler tubes in waste to energy (WTE) incinerators. To study this effect, a series of experiments were planned to determine the mechanism of corrosion of carbon steel boiler tubes under ash deposits. Results reported here were for carbon steel tubes exposed to an environment consisting of O{sub 2}, CO{sub 2}, N{sub 2}, and water vapor. Future experiments will include HCl and SO{sub 2}. Test procedures included both isothermal and thermal gradient tests. Temperatures ranged from 300 C to 510 C for the isothermal tests and a metal/gas temperature of 450/670 C for the thermal gradient test. Initial results indicated that increasing temperature caused the isothermal corrosion rates of ash-covered samples to increase. A shakedown test of a thermal gradient test apparatus was conducted at a metal/gas temperature of 450/670 C, a more severe environment than normally encountered in WTE waterwalls. Results showed that the corrosion rate under those conditions exceeds the isothermal corrosion rates at the same metal temperature by a factor of 2 or more.

Covino, B.S., Jr.; Russell, J.H.; Cramer, S.D.; Holcomb, G.R.; Bullard, S.J.; Ziomek-Moroz, M.; Matthes, S.A.; White, M.L.

2003-03-16T23:59:59.000Z

387

Solid oxide fuel cell operable over wide temperature range  

DOE Patents [OSTI]

Solid oxide fuel cells having improved low-temperature operation are disclosed. In one embodiment, an interfacial layer of terbia-stabilized zirconia is located between the air electrode and electrolyte of the solid oxide fuel cell. The interfacial layer provides a barrier which controls interaction between the air electrode and electrolyte. The interfacial layer also reduces polarization loss through the reduction of the air electrode/electrolyte interfacial electrical resistance. In another embodiment, the solid oxide fuel cell comprises a scandia-stabilized zirconia electrolyte having high electrical conductivity. The scandia-stabilized zirconia electrolyte may be provided as a very thin layer in order to reduce resistance. The scandia-stabilized electrolyte is preferably used in combination with the terbia-stabilized interfacial layer. The solid oxide fuel cells are operable over wider temperature ranges and wider temperature gradients in comparison with conventional fuel cells.

Baozhen, Li (Essex Junction, VT); Ruka, Roswell J. (Pittsburgh, PA); Singhal, Subhash C. (Murrysville, PA)

2001-01-01T23:59:59.000Z

388

Automatic temperature adjustment apparatus  

DOE Patents [OSTI]

An apparatus for increasing the efficiency of a conventional central space heating system is disclosed. The temperature of a fluid heating medium is adjusted based on a measurement of the external temperature, and a system parameter. The system parameter is periodically modified based on a closed loop process that monitors the operation of the heating system. This closed loop process provides a heating medium temperature value that is very near the optimum for energy efficiency.

Chaplin, James E. (66 Overlook Rd., Bloomingdale, NJ 07403)

1985-01-01T23:59:59.000Z

389

North-South asymmetry in the modeled phytoplankton community response to climate change over the 21st century  

E-Print Network [OSTI]

uxes to destratify the water-column. The wind-driven,westerlies drive deep-water upwelling, exposing nutrientand carbon-rich deep waters to the surface. Increases in

Marinov, Irina; Doney, Scott C; Lima, Ivan D; Lindsay, K.; Moore, J. K; Mahowald, N.

2013-01-01T23:59:59.000Z

390

North-South asymmetry in the modeled phytoplankton community response to climate change over the 21st century  

E-Print Network [OSTI]

of com- plex Earth System Models uses widely differentacross the IPCC AR5 earth system models, manuscript in

Marinov, Irina; Doney, Scott C; Lima, Ivan D; Lindsay, K.; Moore, J. K; Mahowald, N.

2013-01-01T23:59:59.000Z

391

Temperature and RH Targets  

Broader source: Energy.gov [DOE]

Presented by Vishal O Mittal of the Florida Solar Energy Center at the High Temperature Membrane Working Group Meeting, San Francisco, September 14, 2006.

392

OPTICAL-NEAR-INFRARED COLOR GRADIENTS AND MERGING HISTORY OF ELLIPTICAL GALAXIES  

SciTech Connect (OSTI)

It has been suggested that merging plays an important role in the formation and the evolution of elliptical galaxies. While gas dissipation by star formation is believed to steepen metallicity and color gradients of the merger products, mixing of stars through dissipation-less merging (dry merging) is believed to flatten them. In order to understand the past merging history of elliptical galaxies, we studied the optical-near-infrared (NIR) color gradients of 204 elliptical galaxies. These galaxies are selected from the overlap region of the Sloan Digital Sky Survey (SDSS) Stripe 82 and the UKIRT Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS). The use of optical and NIR data (g, r, and K) provides large wavelength baselines, and breaks the age-metallicity degeneracy, allowing us to derive age and metallicity gradients. The use of the deep SDSS Stripe 82 images makes it possible for us to examine how the color/age/metallicity gradients are related to merging features. We find that the optical-NIR color and the age/metallicity gradients of elliptical galaxies with tidal features are consistent with those of relaxed ellipticals, suggesting that the two populations underwent a similar merging history on average and that mixing of stars was more or less completed before the tidal features disappeared. Elliptical galaxies with dust features have steeper color gradients than the other two types, even after masking out dust features during the analysis, which can be due to a process involving wet merging. More importantly, we find that the scatter in the color/age/metallicity gradients of the relaxed and merging feature types decreases as their luminosities (or masses) increase at M > 10{sup 11.4} M{sub Sun} but stays large at lower luminosities. Mean metallicity gradients appear nearly constant over the explored mass range, but a possible flattening is observed at the massive end. According to our toy model that predicts how the distribution of metallicity gradients changes as a result of major dry merging, the mean metallicity gradient should flatten by 40% and its scatter becomes smaller by 80% per a mass-doubling scale if ellipticals evolve only through major dry merger. Our result, although limited by a number statistics at the massive end, is consistent with the picture that major dry merging is an important mechanism for the evolution for ellipticals at M > 10{sup 11.4} M{sub Sun }, but is less important at the lower mass range.

Kim, Duho; Im, Myungshin [Center for the Exploration of the Origin of the Universe (CEOU), Astronomy Program, Department of Physics and Astronomy, Seoul National University, 1 Gwanak-rho, Gwanak-gu, Seoul 151-742 (Korea, Republic of)] [Center for the Exploration of the Origin of the Universe (CEOU), Astronomy Program, Department of Physics and Astronomy, Seoul National University, 1 Gwanak-rho, Gwanak-gu, Seoul 151-742 (Korea, Republic of)

2013-04-01T23:59:59.000Z

393

Density gradient free electron collisionally excited X-ray laser  

DOE Patents [OSTI]

An operational X-ray laser (30) is provided that amplifies 3p-3s transition X-ray radiation along an approximately linear path. The X-ray laser (30) is driven by a high power optical laser. The driving line focused optical laser beam (32) illuminates a free-standing thin foil (34) that may be associated with a substrate (36) for improved structural integrity. This illumination produces a generally cylindrically shaped plasma having an essentially uniform electron density and temperature, that exists over a long period of time, and provides the X-ray laser gain medium. The X-ray laser (30) may be driven by more than one optical laser beam (32, 44). The X-ray laser (30) has been successfully demonstrated to function in a series of experimental tests.

Campbell, Edward M. (Pleasanton, CA); Rosen, Mordecai D. (Berkeley, CA)

1989-01-01T23:59:59.000Z

394

Density gradient free electron collisionally excited x-ray laser  

DOE Patents [OSTI]

An operational x-ray laser is provided that amplifies 3p-3s transition x-ray radiation along an approximately linear path. The x-ray laser is driven by a high power optical laser. The driving line focused optical laser beam illuminates a free-standing thin foil that may be associated with a substrate for improved structural integrity. This illumination produces a generally cylindrically shaped plasma having an essentially uniform electron density and temperature, that exists over a long period of time, and provides the x-ray laser gain medium. The x-ray laser may be driven by more than one optical laser beam. The x-ray laser has been successfully demonstrated to function in a series of experimental tests.

Campbell, E.M.; Rosen, M.D.

1984-11-29T23:59:59.000Z

395

Fiber optic temperature sensor  

SciTech Connect (OSTI)

Our fiber optic temperature measurement sensor and system is a major improvement over methods currently in use in most industrial processes, and it delivers all of the attributes required simplicity, accuracy, and cost efficiency-to help improve all of these processes. Because temperature is a basic physical attribute of nearly every industrial and commercial process, our system can eventually result in significant improvements in nearly every industrial and commercial process. Many finished goods, and the materials that go into them, are critically dependent on the temperature. The better the temperature measurement, the better quality the goods will be and the more economically they can be produced. The production and transmission of energy requires the monitoring of temperature in motors, circuit breakers, power generating plants, and transmission line equipment. The more reliable and robust the methods for measuring these temperature, the more available, stable, and affordable the supply of energy will become. The world is increasingly realizing the threats to health and safety of toxic or otherwise undesirable by products of the industrial economy in the environment. Cleanup of such contamination often depends on techniques that require the constant monitoring of temperature in extremely hazardous environments, which can damage most conventional temperature sensors and which are dangerous for operating personnel. Our system makes such monitoring safer and more economical.

Rabold, D.

1995-12-01T23:59:59.000Z

396

High temperature probe  

DOE Patents [OSTI]

A high temperature probe for sampling, for example, smokestack fumes, and is able to withstand temperatures of 3000.degree. F. The probe is constructed so as to prevent leakage via the seal by placing the seal inside the water jacket whereby the seal is not exposed to high temperature, which destroys the seal. The sample inlet of the probe is also provided with cooling fins about the area of the seal to provide additional cooling to prevent the seal from being destroyed. Also, a heated jacket is provided for maintaining the temperature of the gas being tested as it passes through the probe. The probe includes pressure sensing means for determining the flow velocity of an efficient being sampled. In addition, thermocouples are located in various places on the probe to monitor the temperature of the gas passing there through.

Swan, Raymond A. (Fremont, CA)

1994-01-01T23:59:59.000Z

397

High temperature electrochemical corrosion rate probes  

SciTech Connect (OSTI)

Corrosion occurs in the high temperature sections of energy production plants due to a number of factors: ash deposition, coal composition, thermal gradients, and low NOx conditions, among others. Electrochemical corrosion rate (ECR) probes have been shown to operate in high temperature gaseous environments that are similar to those found in fossil fuel combustors. ECR probes are rarely used in energy production plants at the present time, but if they were more fully understood, corrosion could become a process variable at the control of plant operators. Research is being conducted to understand the nature of these probes. Factors being considered are values selected for the Stern-Geary constant, the effect of internal corrosion, and the presence of conductive corrosion scales and ash deposits. The nature of ECR probes will be explored in a number of different atmospheres and with different electrolytes (ash and corrosion product). Corrosion rates measured using an electrochemical multi-technique capabilities instrument will be compared to those measured using the linear polarization resistance (LPR) technique. In future experiments, electrochemical corrosion rates will be compared to penetration corrosion rates determined using optical profilometry measurements.

Bullard, Sophie J.; Covino, Bernard S., Jr.; Holcomb, Gordon R.; Ziomek-Moroz, M.

2005-09-01T23:59:59.000Z

398

A 28-ka history of sea surface temperature, primary productivity and planktonic community variability in the western Arabian Sea  

E-Print Network [OSTI]

resulted in deep convective mixing, cold SSTs and enhanced primary productivity. In contrast, postdeglacial the northern Indian Ocean and central Asia is a major feature of the Earth's climate. During summer Africa to the Indian subcontinent. As the Tibetan Plateau is heated, a gradient of temperature

399

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

SciTech Connect (OSTI)

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.

Gao, Dengliang

2013-03-01T23:59:59.000Z

400

High Temperature Capacitor Development  

SciTech Connect (OSTI)

The absence of high-temperature electronics is an obstacle to the development of untapped energy resources (deep oil, gas and geothermal). US natural gas consumption is projected to grow from 22 trillion cubic feet per year (tcf) in 1999 to 34 tcf in 2020. Cumulatively this is 607 tcf of consumption by 2020, while recoverable reserves using current technology are 177 tcf. A significant portion of this shortfall may be met by tapping deep gas reservoirs. Tapping these reservoirs represents a significant technical challenge. At these depths, temperatures and pressures are very high and may require penetrating very hard rock. Logistics of supporting 6.1 km (20,000 ft) drill strings and the drilling processes are complex and expensive. At these depths up to 50% of the total drilling cost may be in the last 10% of the well depth. Thus, as wells go deeper it is increasingly important that drillers are able to monitor conditions down-hole such as temperature, pressure, heading, etc. Commercial off-the-shelf electronics are not specified to meet these operating conditions. This is due to problems associated with all aspects of the electronics including the resistors and capacitors. With respect to capacitors, increasing temperature often significantly changes capacitance because of the strong temperature dependence of the dielectric constant. Higher temperatures also affect the equivalent series resistance (ESR). High-temperature capacitors usually have low capacitance values because of these dielectric effects and because packages are kept small to prevent mechanical breakage caused by thermal stresses. Electrolytic capacitors do not operate at temperatures above 150oC due to dielectric breakdown. The development of high-temperature capacitors to be used in a high-pressure high-temperature (HPHT) drilling environment was investigated. These capacitors were based on a previously developed high-voltage hybridized capacitor developed at Giner, Inc. in conjunction with a unique high-temperature electrolyte developed during the course of the program. During this program the feasibility of operating a high voltage hybridized capacitor at 230oC was demonstrated. Capacitor specifications were established in conjunction with potential capacitor users. A method to allow for capacitor operation at both ambient and elevated temperatures was demonstrated. The program was terminated prior to moving into Phase II due to a lack of cost-sharing funds.

John Kosek

2009-06-30T23:59:59.000Z

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


401

ACCURATE TEMPERATURE MEASUREMENTS IN A NATURALLY-ASPIRATED RADIATION SHIELD  

SciTech Connect (OSTI)

Experiments and calculations were conducted with a 0.13 mm fine wire thermocouple within a naturally-aspirated Gill radiation shield to assess and improve the accuracy of air temperature measurements without the use of mechanical aspiration, wind speed or radiation measurements. It was found that this thermocouple measured the air temperature with root-mean-square errors of 0.35 K within the Gill shield without correction. A linear temperature correction was evaluated based on the difference between the interior plate and thermocouple temperatures. This correction was found to be relatively insensitive to shield design and yielded an error of 0.16 K for combined day and night observations. The correction was reliable in the daytime when the wind speed usually exceeds 1 m s{sup -1} but occasionally performed poorly at night during very light winds. Inspection of the standard deviation in the thermocouple wire temperature identified these periods but did not unambiguously locate the most serious events. However, estimates of sensor accuracy during these periods is complicated by the much larger sampling volume of the mechanically-aspirated sensor compared with the naturally-aspirated sensor and the presence of significant near surface temperature gradients. The root-mean-square errors therefore are upper limits to the aspiration error since they include intrinsic sensor differences and intermittent volume sampling differences.

Kurzeja, R.

2009-09-09T23:59:59.000Z

402

Many species of endotherms control their core body temperature (Tb) within narrow limits (2C) even when  

E-Print Network [OSTI]

, fluctuations in Tb were often 1471The Journal of Experimental Biology 206, 1471-1478 © 2003 The Company that the temperature gradient between Tb and air temperature (Ta) was larger and solar radiation was lower in winter when Tb­Ta became positive. The use of heterothermy by oryx resulted in storage of 672.4·kJ·day­1

Williams, Jos. B.

403

Low temperature cryoprobe  

DOE Patents [OSTI]

A portable, hand held probe usable within a small confine to produce a point source of nitrogen or helium at a relatively constant temperatures of 77 degrees Kelvin, is discussed. 3 figs.

Sungaila, Z.F.

1988-04-12T23:59:59.000Z

404

High-Temperature Superconductivity  

ScienceCinema (OSTI)

Like astronomers tweaking images to gain a more detailed glimpse of distant stars, physicists at Brookhaven National Laboratory have found ways to sharpen images of the energy spectra in high-temperature superconductors ? materials that carry electrical c

Peter Johnson

2010-01-08T23:59:59.000Z

405

High temperature pressure gauge  

DOE Patents [OSTI]

A high temperature pressure gauge comprising a pressure gauge positioned in fluid communication with one end of a conduit which has a diaphragm mounted in its other end. The conduit is filled with a low melting metal alloy above the diaphragm for a portion of its length with a high temperature fluid being positioned in the remaining length of the conduit and in the pressure gauge.

Echtler, J. Paul (Pittsburgh, PA); Scandrol, Roy O. (Library, PA)

1981-01-01T23:59:59.000Z

406

A cooperative conjugate gradient method for linear systems permitting multithread implementation of low complexity  

E-Print Network [OSTI]

This paper proposes a generalization of the conjugate gradient (CG) method used to solve the equation $Ax=b$ for a symmetric positive definite matrix $A$ of large size $n$. The generalization consists of permitting the scalar control parameters (= stepsizes in gradient and conjugate gradient directions) to be replaced by matrices, so that multiple descent and conjugate directions are updated simultaneously. Implementation involves the use of multiple agents or threads and is referred to as cooperative CG (cCG), in which the cooperation between agents resides in the fact that the calculation of each entry of the control parameter matrix now involves information that comes from the other agents. For a sufficiently large dimension $n$, the use of an optimal number of cores gives the result that the multithread implementation has worst case complexity $O(n^{2+1/3})$ in exact arithmetic. Numerical experiments, that illustrate the interest of theoretical results, are carried out on a multicore computer.

Bhaya, Amit; Niedu, Guilherme; Pazos, Fernando

2012-01-01T23:59:59.000Z

407

Extended Mixture of MLP Experts by Hybrid of Conjugate Gradient Method and Modified Cuckoo Search  

E-Print Network [OSTI]

This paper investigates a new method for improving the learning algorithm of Mixture of Experts (ME) model using a hybrid of Modified Cuckoo Search (MCS) and Conjugate Gradient (CG) as a second order optimization technique. The CG technique is combined with Back-Propagation (BP) algorithm to yield a much more efficient learning algorithm for ME structure. In addition, the experts and gating networks in enhanced model are replaced by CG based Multi-Layer Perceptrons (MLPs) to provide faster and more accurate learning. The CG is considerably depends on initial weights of connections of Artificial Neural Network (ANN), so, a metaheuristic algorithm, the so-called Modified Cuckoo Search is applied in order to select the optimal weights. The performance of proposed method is compared with Gradient Decent Based ME (GDME) and Conjugate Gradient Based ME (CGME) in classification and regression problems. The experimental results show that hybrid MSC and CG based ME (MCS-CGME) has faster convergence and better performa...

Salimi, Hamid; Soltanshahi, Mohammad Ali; Hatami, Javad

2012-01-01T23:59:59.000Z

408

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

SciTech Connect (OSTI)

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.

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

2009-03-10T23:59:59.000Z

409

Reducing communication costs in the conjugate gradient algorithm on distributed memory multiprocessors  

SciTech Connect (OSTI)

The standard formulation of the conjugate gradient algorithm involves two inner product computations. The results of these two inner products are needed to update the search direction and the computed solution. In a distributed memory parallel environment, the computation and subsequent distribution of these two values requires two separate communication and synchronization phases. In this paper, we present a mathematically equivalent rearrangement of the standard algorithm that reduces the number of communication phases. We give a second derivation of the modified conjugate gradient algorithm in terms of the natural relationship with the underlying Lanczos process. We also present empirical evidence of the stability of this modified algorithm.

D`Azevedo, E.F.; Romine, C.H.

1992-09-01T23:59:59.000Z

410

PRECONDITIONED BI-CONJUGATE GRADIENT METHOD FOR RADIATIVE TRANSFER IN SPHERICAL MEDIA  

SciTech Connect (OSTI)

A robust numerical method called the Preconditioned Bi-Conjugate Gradient (Pre-BiCG) method is proposed for the solution of the radiative transfer equation in spherical geometry. A variant of this method called Stabilized Preconditioned Bi-Conjugate Gradient (Pre-BiCG-STAB) is also presented. These are iterative methods based on the construction of a set of bi-orthogonal vectors. The application of the Pre-BiCG method in some benchmark tests shows that the method is quite versatile, and can handle difficult problems that may arise in astrophysical radiative transfer theory.

Anusha, L. S.; Nagendra, K. N. [Indian Institute of Astrophysics, Koramangala, Bangalore 560 034 (India); Paletou, F.; Leger, L. [Laboratoire d'Astrophysique de Toulouse-Tarbes, Universite de Toulouse, CNRS, 14 Ave. E. Belin, 31400 Toulouse (France)

2009-10-10T23:59:59.000Z

411

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

SciTech Connect (OSTI)

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.

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

2009-01-01T23:59:59.000Z

412

Measurement of Asymmetric Optical Pumping of Ions Accelerating in a Magnetic-field Gradient  

SciTech Connect (OSTI)

We report observations of asymmetric optical pumping of argon ions accelerating in a magnetic field gradient. The signature is a difference in the laser-induced-fluorescence (LIF) emission amplitude from a pair of Zeeman-split states. A model that reproduces the dependence of the asymmetry on magnetic-field and ion-velocity gradients is described. With the model, the fluorescence intensity ratio provides a new method of measuring ion collisionality. This phenomenon has implications for interpreting stellar plasma spectroscopy data which often exhibit unequal Zeeman state intensities.

Xuan Sun; Earl Scime; Mahmood Miah; Samuel Cohen; Frederick Skiff

2004-10-28T23:59:59.000Z

413

Correlation of Beam Parameters to Decelerating Gradient in the E-167 Plasma Wakefield Acceleration Experiment  

SciTech Connect (OSTI)

Recent experiments at SLAC have shown that high gradient acceleration of electrons is achievable in meter scale plasmas [1,2]. Results from these experiments show that the wakefield is sensitive to parameters in the electron beam which drives it. In the experiment the bunch length and beam waist location were varied systematically at constant charge. Here we investigate the correlation of peak beam current to the decelerating gradient. Limits on the transformer ratio will also be discussed. The results are compared to simulation.

Blumenfeld, I.; Berry, M.; Decker, F.-J.; Hogan, M.J.; Ischebeck, R.; Iverson, R.; Kirby, N.; Siemann, R.; Walz, D.; /SLAC; Clayton, C.E.; Huang, C.; Joshi, C.; Lu, W.; Marsh, K.A.; Mori, W.B.; Zhou, M.; /UCLA; Katsouleas, T.C.; Muggli, P.; Oz, E.; /Southern California U.

2007-06-27T23:59:59.000Z

414

Adjustable, rapidly switching microfluidic gradient generation using focused travelling surface acoustic waves  

SciTech Connect (OSTI)

We demonstrate a simple device to generate chemical concentration gradients in a microfluidic channel using focused travelling surface acoustic waves (F-TSAW). A pair of curved interdigitated metal electrodes deposited on the surface of a piezoelectric (LiNbO{sub 3}) substrate disseminate high frequency sound waves when actuated by an alternating current source. The F-TSAW produces chaotic acoustic streaming flow upon its interaction with the fluid inside a microfluidic channel, which mixes confluent streams of chemicals in a controlled fashion for an adjustable and rapidly switching gradient generation.

Destgeer, Ghulam; Im, Sunghyuk; Hang Ha, Byung; Ho Jung, Jin; Ahmad Ansari, Mubashshir; Jin Sung, Hyung, E-mail: hjsung@kaist.ac.kr [Department of Mechanical Engineering, KAIST, 291 Daejak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

2014-01-13T23:59:59.000Z

415

Comparison of the gradient flow with cooling in $SU(3)$ pure gauge theory  

E-Print Network [OSTI]

The gradient (Wilson) flow has been introduced recently in order to provide a solid theoretical framework for the smoothing of ultraviolet noise in lattice gauge configurations. It is interesting to ask how it compares with other, more heuristic and numerically cheaper smoothing techniques, such as standard cooling. In this study we perform such a comparison, focusing on observables related to topology. We show that, already for moderately small lattice spacings, standard cooling and the gradient flow lead to equivalent results, both for average quantities and configuration by configuration.

Claudio Bonati; Massimo D'Elia

2014-05-13T23:59:59.000Z

416

Ratcheting Motion of Liquid Drops on Gradient Surfaces Susan Daniel, Sanjoy Sircar, Jill Gliem, and Manoj K. Chaudhury*  

E-Print Network [OSTI]

Ratcheting Motion of Liquid Drops on Gradient Surfaces Susan Daniel, Sanjoy Sircar, Jill Gliem an interesting scenario when thedropissubjectedtoaperiodicforce.Likeaconventional ratchet, the periodic force

Chaudhury, Manoj K.

417

Variable temperature effects on release rates of readily soluble nuclides  

SciTech Connect (OSTI)

In this paper we study the effect of temperature on the release rate of readily soluble nuclides, as affected by a time-temperature dependent diffusion coefficient. In this analysis ground water fills the voids in the waste package at t = 0 and one percent of the inventories of cesium and iodine are immediately dissolved into the void water. Mass transfer resistance of partly failed container and cladding is conservatively neglected. The nuclides move through the void space into the surrounding rock under a concentration gradient. We use an analytic solution to compute the nuclide concentration in the gap or void, and the mass flux rate into the porous rock. 8 refs., 4 figs.

Kim, C.-L.; Light, W.B.; Lee, W.W.-L.; Chambre, P.L.; Pigford, T.H. (Korea Advanced Energy Research Inst., Daeduk (Republic of Korea); Lawrence Berkeley Lab., CA (USA))

1988-09-01T23:59:59.000Z

418

Temperature initiated passive cooling system  

DOE Patents [OSTI]

A passive cooling system for cooling an enclosure only when the enclosure temperature exceeds a maximum standby temperature comprises a passive heat transfer loop containing heat transfer fluid having a particular thermodynamic critical point temperature just above the maximum standby temperature. An upper portion of the heat transfer loop is insulated to prevent two phase operation below the maximum standby temperature.

Forsberg, Charles W. (Oak Ridge, TN)

1994-01-01T23:59:59.000Z

419

Temperature initiated passive cooling system  

DOE Patents [OSTI]

A passive cooling system for cooling an enclosure only when the enclosure temperature exceeds a maximum standby temperature comprises a passive heat transfer loop containing heat transfer fluid having a particular thermodynamic critical point temperature just above the maximum standby temperature. An upper portion of the heat transfer loop is insulated to prevent two phase operation below the maximum standby temperature. 1 fig.

Forsberg, C.W.

1994-11-01T23:59:59.000Z

420

High temperature thermometric phosphors  

DOE Patents [OSTI]

A high temperature phosphor consists essentially of a material having the general formula LuPO{sub 4}:Dy{sub x},Eu{sub y} wherein: 0.1 wt % {<=} x {<=} 20 wt % and 0.1 wt % {<=} y {<=} 20 wt %. The high temperature phosphor is in contact with an article whose temperature is to be determined. The article having the phosphor in contact with it is placed in the environment for which the temperature of the article is to be determined. The phosphor is excited by a laser causing the phosphor to fluoresce. The emission from the phosphor is optically focused into a beam-splitting mirror which separates the emission into two separate emissions, the emission caused by the dysprosium dopant and the emission caused by the europium dopant. The separated emissions are optically filtered and the intensities of the emission are detected and measured. The ratio of the intensity of each emission is determined and the temperature of the article is calculated from the ratio of the intensities of the separate emissions. 2 figs.

Allison, S.W.; Cates, M.R.; Boatner, L.A.; Gillies, G.T.

1999-03-23T23:59:59.000Z

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


421

High temperature thermometric phosphors  

DOE Patents [OSTI]

A high temperature phosphor consists essentially of a material having the general formula LuPO.sub.4 :Dy.sub.(x),Eu.sub.y) wherein: 0.1 wt %.ltoreq.x.ltoreq.20 wt % and 0.1 wt %.ltoreq.y.ltoreq.20 wt %. The high temperature phosphor is in contact with an article whose temperature is to be determined. The article having the phosphor in contact with it is placed in the environment for which the temperature of the article is to be determined. The phosphor is excited by a laser causing the phosphor to fluoresce. The emission from the phosphor is optically focused into a beam-splitting mirror which separates the emission into two separate emissions, the emission caused by the dysprosium dopant and the emission caused by the europium dopent. The separated emissions are optically filtered and the intensities of the emission are detected and measured. The ratio of the intensity of each emission is determined and the temperature of the article is calculated from the ratio of the intensities of the separate emissions.

Allison, Stephen W. (Knoxville, TN); Cates, Michael R. (Oak Ridge, TN); Boatner, Lynn A. (Oak Ridge, TN); Gillies, George T. (Earlysville, VA)

1999-03-23T23:59:59.000Z

422

Temperature Data Evaluation  

SciTech Connect (OSTI)

Groundwater temperature is sensitive to the competing processes of heat flow from below the advective transport of heat by groundwater flow. Because groundwater temperature is sensitive to conductive and advective processes, groundwater temperature may be utilized as a tracer to further constrain the uncertainty of predictions of advective radionuclide transport models constructed for the Nevada Test Site (NTS). Since heat transport, geochemical, and hydrologic models for a given area must all be consistent, uncertainty can be reduced by devaluing the weight of those models that do not match estimated heat flow. The objective of this study was to identify the quantity and quality of available heat flow data at the NTS. One-hundred-forty-five temperature logs from 63 boreholes were examined. Thirteen were found to have temperature profiles suitable for the determination of heat flow values from one or more intervals within the boreholes. If sufficient spatially distributed heat flow values are obtained, a heat transport model coupled to a hydrologic model may be used to reduce the uncertainty of a nonisothermal hydrologic model of the NTS.

Gillespie, David

2003-03-01T23:59:59.000Z

423

High-temperature Pump Monitoring - High-temperature ESP Monitoring...  

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

7 4.4.4 High-temperature Pump Monitoring - High-temperature ESP Monitoring Presentation Number: 018 Investigator: Dhruva, Brindesh (Schlumberger Technology Corp.) Objectives: To...

424

Complete temperature profiles in ultra-high pressure liquid chromatography columns  

SciTech Connect (OSTI)

The temperature profiles were calculated along and across seven packed columns (lengths 30, 50, 100, and 150 mm, i.d., 1 and 2.1 mm, all packed with Acquity UPLC, BEH-C{sub 18} particles, average d{sub p} {approx} 1.7 {micro}m) and their stainless steel tubes (o.d. 4.53 and 6.35 mm). These columns were kept horizontal and sheltered from forced air convection (i.e., under still air conditions), at room temperature. They were all percolated with pure acetonitrile, either under the maximum pressure drop (1034 bar) or at the maximum flow rate (2 mL/min) permitted by the chromatograph. The heat balance equation of chromatographic columns was discretized and solved numerically with minimum approximation. Both the compressibility and the thermal expansion of the eluent were taken into account. The boundary conditions were determined from the experimental measurements of the column inlet pressure and of the temperature profile along the column wall, which were made with a precision better than {+-}0.1 K. These calculation results provide the 3-D temperature profiles along and across the columns. The axial and radial temperature gradients are discussed in relationship with the experimental conditions used. The temperature map obtained permits a prediction of the chromatographic data obtained under a very high pressure gradient.

Gritti, Fabrice [University of Tennessee, Knoxville (UTK); Guiochon, Georges A [ORNL

2008-01-01T23:59:59.000Z

425

Fluorescent temperature sensor  

DOE Patents [OSTI]

The present invention is a fluorescent temperature sensor or optical thermometer. The sensor includes a solution of 1,3-bis(1-pyrenyl)propane within a 1-butyl-1-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquid solvent. The 1,3-bis(1-pyrenyl)propane remains unassociated when in the ground state while in solution. When subjected to UV light, an excited state is produced that exists in equilibrium with an excimer. The position of the equilibrium between the two excited states is temperature dependent.

Baker, Gary A [Los Alamos, NM; Baker, Sheila N [Los Alamos, NM; McCleskey, T Mark [Los Alamos, NM

2009-03-03T23:59:59.000Z

426

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

SciTech Connect (OSTI)

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.

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

2008-01-01T23:59:59.000Z

427

Full-waveform inversion in the time domain with an energy-weighted gradient  

SciTech Connect (OSTI)

When applying full-waveform inversion to surface seismic reflection data, one difficulty is that the deep region of the model is usually not reconstructed as well as the shallow region. We develop an energy-weighted gradient method for the time-domain full-waveform inversion to accelerate the convergence rate and improve reconstruction of the entire model without increasing the computational cost. Three different methods can alleviate the problem of poor reconstruction in the deep region of the model: the layer stripping, depth-weighting and pseudo-Hessian schemes. The first two approaches need to subjectively choose stripping depths and weighting functions. The third one scales the gradient with only the forward propagation wavefields from sources. However, the Hessian depends on wavefields from both sources and receivers. Our new energy-weighted method makes use of the energies of both forward and backward propagated wavefields from sources and receivers as weights to compute the gradient. We compare the reconstruction of our new method with those of the conjugate gradient and pseudo-Hessian methods, and demonstrate that our new method significantly improves the reconstruction of both the shallow and deep regions of the model.

Zhang, Zhigang [Los Alamos National Laboratory; Huang, Lianjie [Los Alamos National Laboratory; Lin, Youzuo [Los Alamos National Laboratory

2011-01-01T23:59:59.000Z

428

LES of the adverse-pressure gradient turbulent boundary layer M. Inoue a,  

E-Print Network [OSTI]

at the University of Melbourne wind tunnel where a plate section with zero pressure gradient is followed by section accurate simulations, for example, of separated flow on the wings of airplanes or for flow through turbine such as the amplified wake of the mean velocity profile and the increasing turbulence intensity in the outer region

Marusic, Ivan

429

Preservation of contrasting geothermal gradients across the Caribbean-North America plate  

E-Print Network [OSTI]

Preservation of contrasting geothermal gradients across the Caribbean-North America plate boundary the North American and Caribbean plates, document a sharp cooling age discontinuity across the fault the Caribbean-North America plate boundary (Motagua Fault, Guatemala), Tectonics, 32, 993­1010, doi:10.1002/tect

Paris-Sud XI, Université de

430

The influence of surface tension gradients on drop coalescence Franois Blanchette,1  

E-Print Network [OSTI]

The influence of surface tension gradients on drop coalescence François Blanchette,1 Laura Messio,2 to elucidating the influence on the coalescence process of a surface tension difference between drop coalescence may occur. Three distinct regimes, depending on the reservoir to drop surface tension ratio, R

Bush, John W.M.

431

2002 Macmillan Magazines Ltd Ion gradients are widely used in transmembrane signal-  

E-Print Network [OSTI]

. These gradients are established by the active transport of ions from low to high electrochemical potentials across the membrane, driven by coupling transport to an energetically favourable process, such as ATP hydrolysis by ion channels that are located in the postsynaptic membrane and activated by neurotransmitters

Alford, Simon

432

Inverted metamorphic sequence in the Sikkim Himalayas: crystallization history, PT gradient and implications  

E-Print Network [OSTI]

Inverted metamorphic sequence in the Sikkim Himalayas: crystallization history, P­T gradient The metapelitic rocks of the Sikkim Himalayas show an inverted metamorphic sequence (IMS) of the complete to be capable of explaining these observations. Key words: Himalayas; inverted Barrovian zones; main central

Ganguly, Jibamitra

433

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

SciTech Connect (OSTI)

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.

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)

2013-06-01T23:59:59.000Z

434

Mixed Aleatory/Epistemic Uncertainty Quantification for Hypersonic Flows via Gradient-Based Optimization  

E-Print Network [OSTI]

Mixed Aleatory/Epistemic Uncertainty Quantification for Hypersonic Flows via Gradient/aleatory uncertainties is demonstrated within the context of hypersonic flows. Specifically, this work focuses in which experimental data is difficult or impossible to obtain, as is the case with hypersonic flows

Anitescu, Mihai

435

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

E-Print Network [OSTI]

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

McMaster University

436

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

E-Print Network [OSTI]

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

Tartakovsky, Daniel M.

437

Measurement of the gradient of the Casimir force between a nonmagnetic sphere and a magnetic plate  

E-Print Network [OSTI]

We measured the gradient of the Casimir force between an Au sphere and a plate made of ferromagnetic metal (Ni). It is demonstrated that the magnetic properties influence the force magnitude. This opens prospective opportunities for the control of the Casimir force in nanotechnology and for obtaining Casimir repulsion by using ferromagnetic dielectrics.

A. A. Banishev; C. -C. Chang; G. L. Klimchitskaya; V. M. Mostepanenko; U. Mohideen

2012-05-04T23:59:59.000Z

438

OnLine IPA Gradient Estimators in Stochastic Continuous Fluid Models  

E-Print Network [OSTI]

On­Line IPA Gradient Estimators in Stochastic Continuous Fluid Models Yorai Wardi # School Perturbation Analysis (IPA) to loss­related and workload­ related metrics in a class of Stochastic Flow Models parameters of interest, such as bu#er size, service rate and inflow rate. The IPA estimators derived

439

On the role of material property gradients in noncontacting thermoelectric NDE  

E-Print Network [OSTI]

On the role of material property gradients in noncontacting thermoelectric NDE Hector Carreon. The thermoelectric power of metals is sensitive to variety of material properties that can affect the measurement the basic appli- cation of thermoelectric materials characterization is metal sorting [1]. However

Nagy, Peter B.

440

Changes in species assemblages and diets of Collembola along a gradient of metal pollution  

E-Print Network [OSTI]

pollution. Keywords: Collembolan communities, Heavy metals, Gut contents 1. Introduction * Corresponding.1016/S0929-1393(02)00134-8 #12;2 Pollution by heavy metals, due to smelter, mining or agricultural the hypothesis that soil animal communities sampled along a gradient of heavy metal pollution show a) shifts

Paris-Sud XI, Université de

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


441

RIS-M-2260 HEAT GRADIENT INDUCED MIGRATION OF BRINE INCLUSIONS IN ROCK SALT  

E-Print Network [OSTI]

RISŘ-M-2260 HEAT GRADIENT INDUCED MIGRATION OF BRINE INCLUSIONS IN ROCK SALT Mathematical treatment project. Abstract. A mathematical model for the brine migration in rock salt around an infinite line heat source is set up. The tempera- ture field around the time dependent heat source is calculated by use

442

Capacitive mixing power production from salinity gradient energy enhanced through exoelectrogen-  

E-Print Network [OSTI]

to generate electrical power directly from salinity gradient energy using capacitive electrodes have recently generation and wastewater treatment. Introduction Harnessing the entropic energy released when river water with these capacitive electrodes two different ways: either through changes in membrane potentials due to ion

443

Condensation on Surface Energy Gradient Shifts Drop Size Distribution toward Small Drops  

E-Print Network [OSTI]

Condensation on Surface Energy Gradient Shifts Drop Size Distribution toward Small Drops Ashley M condensation from vapor onto a cooled surface, distributions of drops evolve by nucleation, growth is condensed onto a horizontally oriented surface that has been treated by silanization to deliver either

Daniel, Susan

444

Using image gradient as a visual feature for visual servoing Eric Marchand, Christophe Collewet  

E-Print Network [OSTI]

Using image gradient as a visual feature for visual servoing Eric Marchand, Christophe Collewet degrees of freedom are considered. Eric Marchand is with Universit´e de Rennes 1, IRISA UMR 6074, INRIA Rennes-Bretagne Atlantique, Lagadic research group, email: Eric.Marchand@irisa.fr, Christophe Collewet

Paris-Sud XI, Université de

445

Creation of a gradient polymer-fullerene interface in photovoltaic devices by thermally controlled interdiffusion  

E-Print Network [OSTI]

by providing im- proved donor/acceptor proximity throughout the device using interpenetrating polymer networks5Creation of a gradient polymer-fullerene interface in photovoltaic devices by thermally controlled 24062-1704 Received 29 July 2002; accepted 27 September 2002 Efficient polymer-fullerene photovoltaic

Heflin, Randy

446

A gradient flow approach to an evolution problem arising in superconductivity  

E-Print Network [OSTI]

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

Serfaty, Sylvia

447

Top hole drilling with dual gradient technology to control shallow hazards  

E-Print Network [OSTI]

3.2 Riserless Dual Gradient Drilling Technology Description .........................36 3.2.1 Kick Detection.............................................................................37 3.2.2 Well Control ?Modified Driller?s Method... ? PRESSURE @ TOP OF KICK GRAPHS ? SET #1..........................140 ix Page APPENDIX F ? PRESSURE @ TOP OF KICK GRAPHS ? SET #2 ..........................159 VITA...

Elieff, Brandee Anastacia Marie

2006-10-30T23:59:59.000Z

448

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

E-Print Network [OSTI]

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, bnĂ°zĂ?, on ten glaciers in Norway also

Rasmussen, L.A.

449

Double-hybrid density-functional theory with meta-generalized-gradient approximations  

E-Print Network [OSTI]

Double-hybrid density-functional theory with meta-generalized-gradient approximations Sidi Ould-parameter double-hybrid density-functional theory [K. Sharkas, J. Toulouse, and A. Savin, J. Chem. Phys. 134 of the most accurate approximations for electronic-structure calculations within density- functional theory

Paris-Sud XI, Université de

450

MICROBIOLOGY OF AQUATIC SYSTEMS Seasonal Depth-Related Gradients in Virioplankton: Lytic  

E-Print Network [OSTI]

of the deepest waters of Lake Pavin is essentially driven by the dark viral loop (dissolved organic matter communities, some of which may be typical, endemic to the ambient dark, cold and stable deep water masses to be representative of the physico-chemical gradients of the water column of the lake, and of the seasonal variability

Paris-Sud XI, Université de

451

PREDICTION OF MOISTURE CONTENT AND MOISTURE GRADIENT OF AN OVERLAID PARTICLEBOARD1  

E-Print Network [OSTI]

PREDICTION OF MOISTURE CONTENT AND MOISTURE GRADIENT OF AN OVERLAID PARTICLEBOARD1 Qinglin Wu and HPL backer. A model based on the diffusion theory was developed to predict MC and moisture distribution for a multi-ply wood composite panel. The model's prediction of the mean MC for a three-layer PB

452

Bayesian Learning via Stochastic Gradient Langevin Dynamics Max Welling welling@ics.uci.edu  

E-Print Network [OSTI]

Bayesian Learning via Stochastic Gradient Langevin Dynamics Max Welling welling@ics.uci.edu D. Bren on iterative learning from small mini-batches. By adding the right amount of noise to a standard stochastic" and collects sam- ples after it has been surpassed. We apply the method to three models: a mixture of Gaussians

Kaski, Samuel

453

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 iterations. We demonstrate our method in simulations with various wind scenarios and prices for energy. INTRODUCTION Today, wind power is the most important renewable energy source. For the years to come, many

454

Can selection on nest size from nest predation explain the latitudinal gradient in clutch size?  

E-Print Network [OSTI]

Can selection on nest size from nest predation explain the latitudinal gradient in clutch size. 2. The nest size hypothesis posits that higher nest predation in the tropics favours selection for smaller nests and thereby constrains clutch size by shrinking available space for eggs and/or nestlings

Martin, Thomas E.

455

Power Grid Analysis Using a Flexible Conjugate Gradient Algorithm with Sparsification  

E-Print Network [OSTI]

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

Freund, Roland W.

456

VIDEO FINGERPRINTING BASED ON CENTROIDS OF GRADIENT ORIENTATIONS Sunil Lee and Chang D. Yoo  

E-Print Network [OSTI]

VIDEO FINGERPRINTING BASED ON CENTROIDS OF GRADIENT ORIENTATIONS Sunil Lee and Chang D. Yoo Dept the video signal. The goal of a video fingerprinting sys- tem is to judge whether two videos have the same contents by measuring distance between fingerprints extracted from the videos. In this paper, a novel video

Yoo, Chang D.

457

Doxorubicin physical state in solution and inside liposomes loaded via a pH gradient  

E-Print Network [OSTI]

R. Perkins aY * a The Liposome Company, Inc., One Research Way, Princeton, NJ 08540, USA b Department of Physics, Cornell University, Ithaca, NY 14853, USA Received 26 May 1998; accepted 9 September/cholesterol liposomes that were loaded via a transmembrane pH gradient. Using cryogenic electron microscopy (cryo-EM) we

Gruner, Sol M.

458

Volume 0 (1981), Number 0 pp. 112 COMPUTER GRAPHICS forum Non-oriented MLS Gradient Fields  

E-Print Network [OSTI]

Volume 0 (1981), Number 0 pp. 1­12 COMPUTER GRAPHICS forum Non-oriented MLS Gradient Fields Jiazhou discrete inputs, a funda- mental stage for a variety of computer graphics applications such as surface a widespread use in graphics applications, as demonstrated by the variety of our results. Categories

Paris-Sud XI, Université de

459

Comparing Stream Geomorphology and Channel Habitat along a Stream Restoration Gradient Sam Stewart  

E-Print Network [OSTI]

Comparing Stream Geomorphology and Channel Habitat along a Stream Restoration Gradient Sam Stewart University #12;Abstract Stream restoration is a growing science due to the realization that the human into a whole reach study. This involved selecting four stream sites that would create a stream restoration

Vallino, Joseph J.

460

Examining food webs and trophic dynamics across a stream restoration intensity gradient  

E-Print Network [OSTI]

Examining food webs and trophic dynamics across a stream restoration intensity gradient Lena Weiss restoration, food webs, trophic dynamics Abstract: Stream ecosystems provide a plethora of important services in the stream channel itself. While there has been a recent push towards restoring these heavily degraded

Vallino, Joseph J.

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


461

Benthic Invertebrate Community Composition in Four Stream across a Restoration Intensity Gradient  

E-Print Network [OSTI]

Benthic Invertebrate Community Composition in Four Stream across a Restoration Intensity Gradient of cranberry farming on streams. These restoration projects vary in their intensity from low restoration streams with varying degrees of restoration intensity to determine if increased restoration intensity more

Vallino, Joseph J.

462

Collaborative Estimation of Gradient Direction by a Formation of AUVs under Communication Constraints  

E-Print Network [OSTI]

of Autonomous Underwater Vehicles (AUVs). The present paper proposes a distributed solution in which a group], and autonomous systems as underwater and unmanned air ve- hicles (AUVs and UAVs) [6], [7]. Cooperative formation of vehicles uniformly distributed in a fixed circular formation, estimates the gradient direction

Paris-Sud XI, Université de

463

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

E-Print Network [OSTI]

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

Fierer, Noah

464

A HEAVY ISOTOPE IN A SOLID DRIFTS DOWN A THERMAL ENERGY GRADIENT  

E-Print Network [OSTI]

183 A HEAVY ISOTOPE IN A SOLID DRIFTS DOWN A THERMAL ENERGY GRADIENT R. V. HESKETH CEGB Berkeley, and indeed, related to the second law ; to the familar statement that thermal energy diffuses from hot to cold we merely add the corollary even when the carriers of thermal energy are isotopic defects

Paris-Sud XI, Université de

465

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

E-Print Network [OSTI]

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

Poole, David

466

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

E-Print Network [OSTI]

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).

Hua-Shu Dou; Boo Cheong Khoo

2010-06-07T23:59:59.000Z

467

Temperature differential detection device  

DOE Patents [OSTI]

A temperature differential detection device for detecting the temperature differential between predetermined portions of a container wall is disclosed as comprising a Wheatstone bridge circuit for detecting resistance imbalance with a first circuit branch having a first elongated wire element mounted in thermal contact with a predetermined portion of the container wall, a second circuit branch having a second elongated wire element mounted in thermal contact with a second predetermined portion of a container wall with the wire elements having a predetermined temperature-resistant coefficient, an indicator interconnected between the first and second branches remote from the container wall for detecting and indicating resistance imbalance between the first and second wire elements, and connector leads for electrically connecting the wire elements to the remote indicator in order to maintain the respective resistance value relationship between the first and second wire elements. The indicator is calibrated to indicate the detected resistance imbalance in terms of a temperature differential between the first and second wall portions. 2 figs.

Girling, P.M.

1986-04-22T23:59:59.000Z

468

Low Temperature Performance Characterization  

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

0.0036 0.0038 0.004 0.0042 Inverse Temperature, 1K Gen2 Electrodes and 1.2M LiPF6 in EC:EMC (3:7 ww) (BID 1935), 4.1V, 3 Sep. Gen2 Electrodes and 1.2M LiPF6 in EC:EMC (3:7 ww)...

469

Direct optimization of the atomic-orbital density matrix using the conjugate-gradient method with a multilevel preconditioner  

E-Print Network [OSTI]

Direct optimization of the atomic-orbital density matrix using the conjugate-gradient method. The optimization of the density matrix is carried out by the conjugate-gradient method with a multilevel-functional methods that are able to treat large systems such as proteins and other mol- ecules of biological interest

Helgaker, Trygve

470

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

E-Print Network [OSTI]

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

Boyer, Edmond

471

Microfluidic system with integrated electroosmotic pumps, concentration gradient generator and fish cell line (RTgill-W1)--towards water toxicity  

E-Print Network [OSTI]

Microfluidic system with integrated electroosmotic pumps, concentration gradient generator and fish that incorporates electroosmotic pumps, a concentration gradient generator and a fish cell line (rainbow trout gill concentration distribution of toxicant in a cell test chamber, (2) an electroosmotic (EO) pump chip

Le Roy, Robert J.

472

Video Operations in the Gradient Domain Fusion of image sequences is a fundamental operation in numerous video applications and usually  

E-Print Network [OSTI]

1 Video Operations in the Gradient Domain Abstract Fusion of image sequences is a fundamental operation in numerous video applications and usually consists of segmentation, matting and compositing. We present a unified framework for performing these operations on video in the gradient domain. Our approach

Cohen-Or, Daniel

473

On the role of internal atmospheric variability in ENSO dynamics  

E-Print Network [OSTI]

~no is linked to a boreal spring phenomenon referred to as the Pacific Meridional Model (MM). The MM, character- ized by an anomalous north-south SST gradient and anomalous surface circulation in the northeasterly trade regime with maximum variance in boreal...

Zhang, Li

2006-10-30T23:59:59.000Z

474

Camberlin P., 2009 : Nile Basin Climates. In "The Nile : Origin, Environments, Limnology and Human Use", Dumont, Henri J. (Ed.), Monographiae Biologicae, Springer, 307-333.  

E-Print Network [OSTI]

with a deficit (to the north of the basin). The excess energy originates from high solar radiation gains, low the areas north of 18°N remain dry most of the year, to the south there is a gradual increase of monsoon. The Hadley circulation is fuelled by a north-south energy gradient between a zone with excess energy (to

Paris-Sud XI, Université de

475

Atmos. Chem. Phys., 11, 35813593, 2011 www.atmos-chem-phys.net/11/3581/2011/  

E-Print Network [OSTI]

in total column carbon dioxide G. Keppel-Aleks, P. O. Wennberg, and T. Schneider California Institute on surface fluxes of CO2. Here we use a general circulation model with a variety of prescribed carbon fluxes by both local fluxes and advec- tion. On seasonal scales, gradients are set by the north-south flux

Meskhidze, Nicholas

476

Localized temperature stability of low temperature cofired ceramics  

DOE Patents [OSTI]

The present invention is directed to low temperature cofired ceramic modules having localized temperature stability by incorporating temperature coefficient of resonant frequency compensating materials locally into a multilayer LTCC module. Chemical interactions can be minimized and physical compatibility between the compensating materials and the host LTCC dielectrics can be achieved. The invention enables embedded resonators with nearly temperature-independent resonance frequency.

Dai, Steven Xunhu

2013-11-26T23:59:59.000Z

477

Method for producing ceramic composition having low friction coefficient at high operating temperatures  

DOE Patents [OSTI]

A method for producing a stable ceramic composition having a surface with a low friction coefficient and high wear resistance at high operating temperatures. A first deposition of a thin film of a metal ion is made upon the surface of the ceramic composition and then a first ion implantation of at least a portion of the metal ion is made into the near surface region of the composition. The implantation mixes the metal ion and the ceramic composition to form a near surface composite. The near surface composite is then oxidized sufficiently at high oxidizing temperatures to form an oxide gradient layer in the surface of the ceramic composition.

Lankford, Jr., James (San Antonio, TX)

1988-01-01T23:59:59.000Z

478

High Temperature Membrane Working Group  

Broader source: Energy.gov [DOE]

This presentation provides an overview of the High Temperature Membrane Working Group Meeting in May 2007.

479

Engine Cylinder Temperature Control  

DOE Patents [OSTI]

A method and apparatus for controlling a temperature in a combustion cylinder in an internal combustion engine. The cylinder is fluidly connected to an intake manifold and an exhaust manifold. The method and apparatus includes increasing a back pressure associated with the exhaust manifold to a level sufficient to maintain a desired quantity of residual exhaust gas in the cylinder, and varying operation of an intake valve located between the intake manifold and the cylinder to an open duration sufficient to maintain a desired quantity of fresh air from the intake manifold to the cylinder, wherein controlling the quantities of residual exhaust gas and fresh air are performed to maintain the temperature in the cylinder at a desired level.

Kilkenny, Jonathan Patrick (Peoria, IL); Duffy, Kevin Patrick (Metamora, IL)

2005-09-27T23:59:59.000Z

480

Manufacturing High Temperature Systems  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion | Department of Energy Low-TemperatureEnergyAll ManufacturingFoodOctoberto DOE

Note: This page contains sample records for the topic "north-south temperature gradient" from the National Library of EnergyBeta (NLEBeta).
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481

Radial convection of finite ion temperature, high amplitude plasma blobs  

SciTech Connect (OSTI)

We present results from simulations of seeded blob convection in the scrape-off-layer of magnetically confined fusion plasmas. We consistently incorporate high fluctuation amplitude levels and finite Larmor radius (FLR) effects using a fully nonlinear global gyrofluid model. This is in line with conditions found in tokamak scrape-off-layers (SOL) regions. Varying the ion temperature, the initial blob width, and the initial amplitude, we found an FLR dominated regime where the blob behavior is significantly different from what is predicted by cold-ion models. The transition to this regime is very well described by the ratio of the ion gyroradius to the characteristic gradient scale length of the blob. We compare the global gyrofluid model with a partly linearized local model. For low ion temperatures, we find that simulations of the global model show more coherent blobs with an increased cross-field transport compared to blobs simulated with the local model. The maximal blob amplitude is significantly higher in the global simulations than in the local ones. When the ion temperature is comparable to the electron temperature, global blob simulations show a reduced blob coherence and a decreased cross-field transport in comparison with local blob simulations.

Wiesenberger, M., E-mail: Matthias.Wiesenberger@uibk.ac.at; Kendl, A. [Institute for Ion Physics and Applied Physics, Association EURATOM-ÖAW, University of Innsbruck, A-6020 Innsbruck (Austria); Madsen, J. [Association EURATOM-DTU, Department of Physics, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark)

2014-09-15T23:59:59.000Z

482

Imaging diffusion with non-uniform B{sub 1} gradients.  

SciTech Connect (OSTI)

Rotating-frame imaging with the mathematically well-defined, non-constant magnetic field gradient of toroid cavity detectors represents a new technique to evaluate diffusion in solids, fluids or mixed-phase systems. While conventional NMR methods to measure diffusion utilize constant magnetic field gradients and, therefore, constant k-space wave numbers across the sample volume, the hyperbolic B{sub 1} fields of toroid cavity detectors exhibit large ranges of wave numbers radially distributed around the central conductor. As a consequence, signal amplitudes decay depending on the radial distance from the center axis of the torus. Applying a numerical finite-difference procedure to solve partial differential transport equations makes it possible not only to determine diffusion in toroid detectors to a high precision but also to include and accurately reproduce transport phenomena at or through singularities, such as phase transitions, membranes or impermeable boundaries.

Woelk, K.

1998-01-30T23:59:59.000Z

483

Stellar Population Gradients in Bulges along the Hubble Sequence: I. The Data  

E-Print Network [OSTI]

This is the first paper presenting our long-term project aimed at studying the nature of bulges through the analysis of their stellar population gradients. We present deep spectroscopic observations along the minor axis and the data reduction for a sample of 32 bulges of edge-on spiral galaxies. We explain in detail our procedures to measure their dynamical parameters (rotation curves and velocity dispersion profiles) and line-strength indices, including the conversion to the Lick/IDS system. Tables giving the values of the dynamical parameters and line-strength indices at each galactocentric radius are presented (in electronic form) for each galaxy of the sample. The derived line-strength gradients from this dataset will be analyzed in a forthcoming paper to set constraints on the different scenarios for the formation of the bulges.

J. Gorgas; P. Jablonka; P. Goudfrooij

2007-07-03T23:59:59.000Z

484

Beyond-the-Standard-Model matrix elements with the gradient flow  

E-Print Network [OSTI]

At the Forschungszentrum Juelich (FZJ) we have started a long-term program that aims to determine beyond-the-Standard-Model (BSM) matrix elements using the gradient flow, and to understand the impact of BSM physics in nucleon and nuclear observables. Using the gradient flow, we propose to calculate the QCD component of key beyond the Standard Model (BSM) matrix elements related to quark and strong theta CP violation and the strange content within the nucleon. The former set of matrix elements impacts our understanding of Electric Dipole Moments (EDMs) of nucleons and nuclei (a key signature of BSM physics), while the latter contributes to elastic recoil of Dark Matter particles off nucleons and nuclei. If successful, these results will lay the foundation for extraction of BSM observables from future low-energy, high-intensity and high-accuracy experimental measurements.

A. Shindler; J. de Vries; T. Luu

2014-09-10T23:59:59.000Z

485

A magnetically shielded room with ultra low residual field and gradient  

SciTech Connect (OSTI)

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.

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

2014-07-15T23:59:59.000Z

486

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

SciTech Connect (OSTI)

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.

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

1996-07-15T23:59:59.000Z

487

Automatic code generation enables nuclear gradient computations for fully internally contracted multireference theory  

E-Print Network [OSTI]

Analytical nuclear gradients for fully internally contracted complete active space second-order perturbation theory (CASPT2) are reported. This implementation has been realized by an automated code generator that can handle spin-free formulas for the CASPT2 energy and its derivatives with respect to variations of molecular orbitals and reference coefficients. The underlying complete active space self-consistent field and the so-called Z-vector equations are solved using density fitting. With full internal contraction the size of first-order wave functions scales polynomially with the number of active orbitals. The CASPT2 gradient program and the code generator are both publicly available. This work enables the CASPT2 geometry optimization of molecules as complex as those investigated by respective single-point calculations.

MacLeod, Matthew K

2015-01-01T23:59:59.000Z

488

Development of High-Gradient Dielectric Laser-Driven Particle Accelerator Structures  

SciTech Connect (OSTI)

The thrust of Stanford's program is to conduct research on high-gradient dielectric accelerator structures driven with high repetition-rate, tabletop infrared lasers. The close collaboration between Stanford and SLAC (Stanford Linear Accelerator Center) is critical to the success of this project, because it provides a unique environment where prototype dielectric accelerator structures can be rapidly fabricated and tested with a relativistic electron beam.

Byer, Robert L.

2013-11-07T23:59:59.000Z

489

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

E-Print Network [OSTI]

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.

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

2014-08-05T23:59:59.000Z

490

X-band EPR imaging as a tool for gradient dose reconstruction in irradiated bones  

SciTech Connect (OSTI)

Purpose: Various tools are currently available for dose reconstruction in individuals after accidental exposure to ionizing radiation. Among the available biological analyses, Monte Carlo simulations, and biophysical methods, such as electron paramagnetic resonance (EPR), the latter has proved its usefulness for retrospective dosimetry. Although EPR spectroscopy is probably the most sensitive technique, it does not provide spatial dosimetric data. This information is, however, highly desirable when steep dose gradient irradiations are involved. The purpose of this work was to explore the possibilities of EPR imaging (EPRI) for spatial dose reconstruction in irradiated biological material. Methods: X-band EPRI was used to reconstruct ex vivo the relative dose distribution in human bone samples and hydroxyapatite phantoms after irradiation with brachytherapy seeds or x rays. Three situations were investigated: Homogeneous, stepwise gradient, and continuous gradient irradiation. Results: EPRI gave a faithful relative spin density distribution in bone samples and in hydroxyapatite phantoms. Measured dose ratios were in close agreement with the actual delivered dose ratios. EPRI was able to distinguish the dose gradients induced by two different sources ({sup 125}I and {sup 192}Ir). However, the measured spatial resolution of the system was 1.9 mm and this appeared to be a limiting factor. The method could be improved by using new signal postprocessing strategies. Conclusions: This study demonstrates that EPRI can be used to assess the regional relative dose distribution in irradiated bone samples. The method is currently applicable to ex vivo measurements of small size samples with low variation in tissue density but is likely to be adapted for in vivo application using L-band EPRI.

Leveque, Philippe; Godechal, Quentin; Bol, Anne; Trompier, Francois; Gallez, Bernard [Biomedical Magnetic Resonance Unit, Universite catholique de Louvain, B-1200 Brussels (Belgium); Molecular Imaging and Experimental Radiotherapy Unit, Universite catholique de Louvain, B-1200 Brussels (Belgium); Institut de Surete Nucleaire et de Radioprotection, F-92262 Fontenay-aux-Roses (France); Biomedical Magnetic Resonance Unit, Universite catholique de Louvain, B-1200 Brussels (Belgium)

2009-09-15T23:59:59.000Z

491

Semi-Blind Gradient-Newton CMA and SDD Algorithm for MIMO Space-Time Equalisation  

E-Print Network [OSTI]

Semi-Blind Gradient-Newton CMA and SDD Algorithm for MIMO Space-Time Equalisation S. Chen, L. HanzoBJ, UK. E-mails: {sqc, lh, htc1e08}@ecs.soton.ac.uk Abstract-- Semi-blind space-time equalisation-directed scheme is then applied to adapt the STE. The proposed semi-blind adaptive STE is capable of converging

Chen, Sheng

492

Comment on 'Simultaneous gravity and gradient measurements from a recoil-compensated absolute gravimeter'  

E-Print Network [OSTI]

The article (Niebauer et al. 2011 Metrologia 48 154-163) reports on the important innovations enhancing the ability of absolute gravimeter to measure vertical gravity gradient along with the gravity acceleration. This comment suggests experiments to further assess the improvements and the results obtained with the modified instrument, considers some limitations of non-linear models in metrology and ways to overcome them, and discusses possible applications of the described instrument.

Nagornyi, V D

2011-01-01T23:59:59.000Z

493

Spatial Gradients in Particle Reinforced Polymers Characterized by X-Ray Attenuation and Laser Confocal Microscopy  

SciTech Connect (OSTI)

The goal of this work is to develop techniques for measuring gradients in particle concentration within filled polymers, such as encapsulant. A high concentration of filler particles is added to such materials to tailor physical properties such as thermal expansion coefficient. Sedimentation and flow-induced migration of particles can produce concentration gradients that are most severe near material boundaries. Therefore, techniques for measuring local particle concentration should be accurate near boundaries. Particle gradients in an alumina-filled epoxy resin are measured with a spatial resolution of 0.2 mm using an x-ray beam attenuation technique, but an artifact related to the finite diameter of the beam reduces accuracy near the specimen's edge. Local particle concentration near an edge can be measured more reliably using microscopy coupled with image analysis. This is illustrated by measuring concentration profiles of glass particles having 40 {micro}m median diameter using images acquired by a confocal laser fluorescence microscope. The mean of the measured profiles of volume fraction agrees to better than 3% with the expected value, and the shape of the profiles agrees qualitatively with simple theory for sedimentation of monodisperse particles. Extending this microscopy technique to smaller, micron-scale filler particles used in encapsulant for microelectronic devices is illustrated by measuring the local concentration of an epoxy resin containing 0.41 volume fraction of silica.

LAGASSE,ROBERT R.; THOMPSON,KYLE R.

2000-06-12T23:59:59.000Z

494

Effect of resistivity gradient on laser-driven electron transport and ion acceleration  

SciTech Connect (OSTI)

The effect of resistivity gradient on laser-driven electron transport and ion acceleration is investigated using collisional particle-in-cell simulation. The study is motivated by recent proton acceleration experiments [Gizzi et al., Phys. Rev. ST Accel. Beams 14, 011301 (2011)], which showed significant effect of the resistivity gradient in layered targets on the proton angular spread. This effect is reproduced in the present simulations. It is found that resistivity-gradient generation of magnetic fields and inhibition of electron transport is significantly enhanced when the feedback interaction between the magnetic field and the fast-electron current is included. Filamentation of the laser-generated hot electron jets inside the target, considered as the origin of the nonuniform proton patterns observed in the experiments, is clearly suppressed by the resistive magnetic field. As a result, the electrostatic sheath field at the target back surface acquires a relatively smooth profile, which contributes to the superior quality of the proton beams accelerated off layered targets in the experiments.

Zhuo, H. B.; Yang, X. H.; Ma, Y. Y.; Li, X. H. [College of Science, National University of Defense Technology, Changsha 410073 (China)] [College of Science, National University of Defense Technology, Changsha 410073 (China); Zhou, C. T. [College of Science, National University of Defense Technology, Changsha 410073 (China) [College of Science, National University of Defense Technology, Changsha 410073 (China); Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); Yu, M. Y. [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China) [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China); Institute for Theoretical Physics I, Ruhr University, Bochum D-44780 (Germany)

2013-09-15T23:59:59.000Z

495

A new high-gradient correction quadrupole for the Fermilab luminosity upgrade  

SciTech Connect (OSTI)

Special superconducting correction quadrupoles are needed for the luminosity upgrade of the Fermilab Tevatron Collider. These correctors are part of the low-beta system for the interaction regions at B/phi/ and D/phi/. The requirements are high gradient and low current. A quadrupole has been designed that meets the operating gradient of 0.63 T/cm at 1086 A. The one-layer quadrupole is wound with a cable consisting of five individually insulated rectangular strands. The five strands are overwrapped with Kapton and epoxy impregnated glass tape. The winding, curing and collaring of the magnet is accomplished in the same manner as Tevatron-like magnets using Rutherford style cable. Once the magnet is complete the five strands are connected in series. A prototype quadrupole has been assembled and tested. The magnet reached a plateau current of 1560 A corresponding to a gradient of 0.91 T/cm without training. The measured field harmonics are substantially better than required. 8 refs., 6 figs., 4 tabs.

Mantsch, P.; Carson, J.; Riddiford, A.; Lamm, M.J.

1989-03-01T23:59:59.000Z

496

Quasilinear dynamics of a cloud of hot electrons propagating through a plasma with decreasing density and temperature  

SciTech Connect (OSTI)

The effects of plasma inhomogeneities on the propagation of a cloud of hot electrons through a cold background plasma and generation of Langmuir waves are investigated using numerical simulations of the quasilinear equations. It is found that in a plasma with decreasing density the quasilinear relaxation of the electron distribution in velocity space is accelerated and the levels of the generated Langmuir waves are enhanced. The magnitude of the induced emission rate is increased and its maximum value moves to lower velocities. Due to density gradient the height of plateau shows an increase at small distances and a corresponding decrease at large distances. It is also found that in a plasma with decreasing temperature, the relaxation of the beam is retarded, the spectral density of Langmuir waves is broadened, and the height of the plateau decreases below its value in a uniform plasma. In the presence of both density and temperature gradients, at given position, the height and upper boundary of the plateau and the level of Langmuir waves are all increased at small velocities. The spatial expansion of the beam is increased by the plasma inhomogeneities, but its average velocity of propagation decreases. Initially, at a given position, the velocity at the upper boundary of the plateau is smaller in the presence of the density gradient than in the uniform plasma but the reverse is true at longer times. Due to temperature gradient, at large times and small distances, the upper boundary of the plateau is increased above its value in the uniform plasma. Because of fast relaxation, the value of the lower boundary of the plateau in the plasma with decreasing density is always less than its value in the uniform plasma. It is found that the local velocity of the beam decreases when the density gradient is present. The local velocity spread of the beam remains unchanged during the propagation of the beam in the uniform plasma, but increases in the presence of inhomogeneities.

Foroutan, G. [Department of Physics, Faculty of Science, Sahand University of Technology, Tabriz 51335-1996 (Iran, Islamic Republic of); School of Physics, The University of Sydney, Sydney NSW 2006 (Australia); Khalilpour, H.; Moslehi-Fard, M. [Faculty of Physics, Tabriz University, Tabriz 51664 (Iran, Islamic Republic of); Li, B.; Robinson, P. A. [School of Physics, University of Sydney, Sydney NSW 2006 (Australia)

2008-12-15T23:59:59.000Z

497

Nanoparticle manipulation in the near-substrate areas of low-temperature, high-density rf plasmas  

SciTech Connect (OSTI)

Manipulation of a single nanoparticle in the near-substrate areas of high-density plasmas of low-temperature glow discharges is studied. It is shown that the nanoparticles can be efficiently manipulated by the thermophoretic force controlled by external heating of the substrate stage. Particle deposition onto or repulsion from nanostructured carbon surfaces critically depends on the values of the neutral gas temperature gradient in the near-substrate areas, which is directly measured in situ in different heating regimes by originally developed temperature gradient probe. The measured values of the near-surface temperature gradient are used in the numerical model of nanoparticle dynamics in a variable-length presheath. Specific conditions enabling the nanoparticle to overcome the repulsive potential and deposit on the substrate during the discharge operation are investigated. The results are relevant to fabrication of various nanostructured films employing structural incorporation of the plasma-grown nanoparticles, in particular, to nanoparticle deposition in the plasma-enhanced chemical-vapor deposition of carbon nanostructures in hydrocarbon-based plasmas.

Rutkevych, P.P.; Ostrikov, K.; Xu, S. [Plasma Sources and Applications Center, National Institute of Education (NIE), Nanyang Technological University, 1 Nanyang Walk, Singapore 637616 (Singapore); School of Physics, The University of Sydney, Sydney, New South Wales 2006 (Australia); Plasma Sources and Applications Center, National Institute of Education (NIE), Nanyang Technological University, 1 Nanyang Walk, Singapore 637616 (Singapore)

2005-10-01T23:59:59.000Z

498

Thermionic converter temperature controller  

DOE Patents [OSTI]

A method and apparatus for controlling the temperature of a thermionic reactor over a wide range of operating power, including a thermionic reactor having a plurality of integral cesium reservoirs, a honeycomb material disposed about the reactor which has a plurality of separated cavities, a solid sheath disposed about the honeycomb material and having an opening therein communicating with the honeycomb material and cavities thereof, and a shell disposed about the sheath for creating a coolant annulus therewith so that the coolant in the annulus may fill the cavities and permit nucleate boiling during the operation of the reactor.

Shaner, Benjamin J. (McMurray, PA); Wolf, Joseph H. (Pittsburgh, PA); Johnson, Robert G. R. (Trafford, PA)

2001-04-24T23:59:59.000Z

499

Thermionic Converter Temperature Controller  

SciTech Connect (OSTI)

A method and apparatus for controlling the temperature of a thermionic reactor over a wide range of operating power, including a thermionic reactor having a plurality of integral cesium reservoirs, a honeycomb material disposed about the reactor which has a plurality of separated cavities, a solid sheath disposed about the honeycomb material and having an opening therein communicating with the honeycomb material and cavities thereof, and a shell disposed about the sheath for creating a coolant annulus therewith so that the coolant in the annulus may fill the cavities and permit nucleate boiling during the operation of the reactor.

Shaner,B. J.; Wolf, Joseph H.; Johnson, Robert G. R.

1999-08-23T23:59:59.000Z

500

Drexel University Temperature Sensors  

SciTech Connect (OSTI)

This document summarizes background information and presents results related to temperature measurements in the Advanced Test Reactor (ATR) National Scientific User Facility (NSUF) Drexel University Project 31091 irradiation. The objective of this test was to assess the radiation performance of new ceramic materials for advanced reactor applications. Accordingly, irradiations of transition metal carbides and nitrides were performed using the Hydraulic Shuttle Irradiation System (HSIS) in the B-7 position and in static capsules inserted into the A-3 and East Flux Trap Position 5 locations of the ATR.

K. L. Davis; D. L. Knudson; J. L. Rempe; B. M. Chase

2014-09-01T23:59:59.000Z