Sample records for temperature gradient wells

  1. Temperatures and interval geothermal-gradient determinations from wells in National Petroleum Reserve in Alaska

    SciTech Connect (OSTI)

    Blanchard, D.C.; Tailleur, I.L.

    1983-12-15T23:59:59.000Z

    Temperature and related records from 28 wells in the National Petroleum Reserve in Alaska (NPRA) although somewhat constrained from accuracy by data gathering methods, extrapolate to undisturbed formation temperatures at specific depths below permafrost, and lead to calculated geothermal graidents between these depths. Tabulation of the results show that extrapolated undisturbed temperatures range from a minimum of 98/sup 0/F (37/sup 0/C) at 4000 feet (1220 m) to a maximum of 420/sup 0/F (216/sup 0/C) at 20,260 feet (6177 m) and that geothermal gradients range from 0.34/sup 0/F/100' (6/sup 0/C/km) between 4470 feet to 7975 feet (Lisburne No. 1) and 3.15/sup 0/F/100' (57/sup 0/C/km) between 6830 feet to 7940 feet (Drew Point No. 1). Essential information needed for extrapolations consists of: time-sequential bottom-hole temperatures during wire-line logging of intermediate and deep intervals of the borehole; the times that circulating drilling fluids had disturbed the formations; and the subsequent times that non-circulating drilling fluids had been in contact with the formation. In several wells presumed near direct measures of rock temperatures recorded from formation fluids recovered by drill stem tests (DST) across thin (approx. 10-20 foot) intervals are made available. We believe that the results approach actual values close enough to serve as approximations of the thermal regimes in appropriate future investigations. Continuous temperature logs obtained at the start and end of final logging operations, conductivity measurements, and relatively long-term measurements of the recovery from disturbance at shallow depths in many of the wells will permit refinements of our values and provide determination of temperatures at other depths. 4 references, 6 figures, 3 tables.

  2. Penrose Well Temperatures

    SciTech Connect (OSTI)

    Christopherson, Karen

    2013-03-15T23:59:59.000Z

    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

  3. Hot Pot Contoured Temperature Gradient Map

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

    Lane, Michael

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

  4. Hot Pot Contoured Temperature Gradient Map

    SciTech Connect (OSTI)

    Lane, Michael

    2013-06-28T23:59:59.000Z

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

  5. Pumpernickel Valley Geothermal Project Thermal Gradient Wells

    SciTech Connect (OSTI)

    Z. Adam Szybinski

    2006-01-01T23:59:59.000Z

    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

  6. Short wavelength ion temperature gradient turbulence

    SciTech Connect (OSTI)

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

    2012-10-15T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Kaski, Samuel

    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

  8. 9519 biotite granodiorite reacted in a temperature gradient

    SciTech Connect (OSTI)

    Charles, R.W.; Bayhurst, G.K.

    1980-10-01T23:59:59.000Z

    A biotite granodiorite from the Fenton Hill Hot Dry Rock (HDR) geothermal system was reacted in a controlled temperature gradient with initially distilled water for 60d. Polished rock prisms were located in the gradient at 72, 119, 161, 209, 270, and 310/sup 0/C. Scanning electron microscope and microprobe analyses show the appearance of secondary phases: Ca-montmorillonite at 72/sup 0/C and 119/sup 0/C; zeolite, either stilbite or heulandite, at 161/sup 0/C; and another zeolite, thomsonite, at higher temperatures. Solution analyses show a steady state equilibrium exists between solution and overgrowths after about 2 weeks of reaction. The chemographic relations for the system are explored in some detail indicating the divariant assemblages may be placed in a reasonable sequence in intensive variable space. These relations predict high and low temperature effects not directly observed experimentally as well as relevant univariant equilibria. Solution chemistry indicates the Na-Ca-K geothermometer more adequately predicts temperature in this system than does the silica geothermometer.

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

    E-Print Network [OSTI]

    Hammett, Greg

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

  10. Reduction of particle deposition on substrates using temperature gradient control

    DOE Patents [OSTI]

    Rader, Daniel J. (Albuquerque, NM); Dykhuizen, Ronald C. (Albuquerque, NM); Geller, Anthony S. (Albuquerque, NM)

    2000-01-01T23:59:59.000Z

    A method of reducing particle deposition during the fabrication of microelectronic circuitry is presented. Reduction of particle deposition is accomplished by controlling the relative temperatures of various parts of the deposition system so that a large temperature gradient near the surface on which fabrication is taking place exists. This temperature gradient acts to repel particles from that surface, thereby producing cleaner surfaces, and thus obtaining higher yields from a given microelectronic fabrication process.

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

    Open Energy Info (EERE)

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

  12. 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...

  13. Measurements of aerosol thermophoretic deposition: Transition with temperature gradient

    SciTech Connect (OSTI)

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

    1995-12-31T23:59:59.000Z

    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.

  14. Manipulation of Colloids by Nonequilibrium Depletion Force in Temperature Gradient

    E-Print Network [OSTI]

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

    2009-04-22T23:59:59.000Z

    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.

  15. Auburn low-temperature geothermal well. Volume 6. Final report

    SciTech Connect (OSTI)

    Lynch, R.S.; Castor, T.P.

    1983-12-01T23:59:59.000Z

    The Auburn well was drilled to explore for low temperature geothermal resources in central New York State. The Auburn site was selected based on: its proximity to the Cayuga County anomaly (30/sup 0/C/km), its favorable local geological conditions and the potential to provide hot water and space heating to two educational facilities. The well was drilled to a total depth of 5250 feet and into the Pre-Cambrian Basement. The well was extensively logged, flow and stress tested, hydraulically stimulated, and pump (pressure transient analysis) tested. The low-temperature geothermal potential was assessed in terms of: geological environment; hydrological conditions; reservoir characteristics; and recoverable hydrothermal reserves. The average geothermal gradient was measured to be as high as 26.7/sup 0/C/km with a bottom-hole temperature of 126/sup 0/ +- 1/sup 0/F. The proved volumetric resources were estimated to be 3.0 x 10/sup 6/ stock tank barrels (STB) with a maximum initial deliverability of approx.11,600 STB/D and a continuous deliverability of approx.3400 STB/D. The proved hydrothermal reserves were estimated to be 21.58 x 10/sup 10/ Btu based on a volumetric component (4.13 x 10/sup 10/ Btu), and a reinjection component (17.45 x 10/sup 10/ Btu). The conclusion was made that the Auburn low-temperature reservoir could be utilized to provide hot water and space heating to the Auburn School District.

  16. Temperature behavior in the build section of multilateral wells

    E-Print Network [OSTI]

    Romero Lugo, Analis Alejandra

    2005-11-01T23:59:59.000Z

    would be most useful. Parameters that were varied for this experiment included fluid thermal properties, absolute values of temperature and pressure, geothermal gradients, flow rates from each lateral, and the trajectories of each build section. From...

  17. Formation of Complex Structures in Dusty Plasmas under Temperature Gradients

    SciTech Connect (OSTI)

    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

    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.

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

    SciTech Connect (OSTI)

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

    2012-08-15T23:59:59.000Z

    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.

  19. Pagosa Springs Private Wells Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Private Wells Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Pagosa Springs Private Wells Space Heating Low Temperature Geothermal Facility...

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

    SciTech Connect (OSTI)

    Holcomb, G.R.

    2008-04-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    1988-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  3. Tripolar vortex formation in dense quantum plasma with ion-temperature-gradients

    SciTech Connect (OSTI)

    Qamar, Anisa; Ata-ur-Rahman [Institute of Physics and Electronics, University of Peshawar, Khyber Pakhtoon Khwa 25000 (Pakistan); National Center for Physics Shahdrah Valley Road, Islamabad 44000 (Pakistan); Mirza, Arshad M. [Theoretical Plasma Physics Group, Physics Department, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

    2012-05-15T23:59:59.000Z

    We have derived system of nonlinear equations governing the dynamics of low-frequency electrostatic toroidal ion-temperature-gradient mode for dense quantum magnetoplasma. For some specific profiles of the equilibrium density, temperature, and ion velocity gradients, the nonlinear equations admit a stationary solution in the form of a tripolar vortex. These results are relevant to understand nonlinear structure formation in dense quantum plasmas in the presence of equilibrium ion-temperature and density gradients.

  4. 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...

  5. Calcite Mineral Scaling Potentials of High-Temperature Geothermal Wells

    E-Print Network [OSTI]

    Karlsson, Brynjar

    #12;i Calcite Mineral Scaling Potentials of High-Temperature Geothermal Wells Alvin I. Remoroza-Temperature Geothermal Wells Alvin I. Remoroza 60 ECTS thesis submitted in partial fulfillment of a Magister Scientiarum #12;iv Calcite Mineral Scaling Potentials of High-Temperature Geothermal Wells 60 ECTS thesis

  6. Temperature behavior in the build section of multilateral wells 

    E-Print Network [OSTI]

    Romero Lugo, Analis Alejandra

    2005-11-01T23:59:59.000Z

    Intelligent well completions are increasingly being used in horizontal, multilateral, and multi-branching wells. Such completions are equipped with permanent sensors to measure temperature and pressure profiles, which must ...

  7. Lithologic Descriptions and Temperature Profiles of Five Wells...

    Open Energy Info (EERE)

    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....

  8. On the maintenance of weak meridional temperature gradients during warm climates

    E-Print Network [OSTI]

    Korty, Robert Lindsay

    2005-01-01T23:59:59.000Z

    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 ...

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

    SciTech Connect (OSTI)

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

    1981-08-01T23:59:59.000Z

    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.

  10. Interpreting Horizontal Well Flow Profiles and Optimizing Well Performance by Downhole Temperature and Pressure Data

    E-Print Network [OSTI]

    Li, Zhuoyi

    2011-02-22T23:59:59.000Z

    be used to obtain downhole flow conditions, which is key information to control and optimize horizontal well production. However, the fluid flow in the reservoir is often multiphase and complex, which makes temperature and pressure interpretation very...

  11. Probing plasma turbulence by modulating the electron temperature gradient

    E-Print Network [OSTI]

    DeBoo, J. C.

    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 ...

  12. Scalings of energetic particle transport by ion temperature gradient microturbulencea...

    E-Print Network [OSTI]

    Lin, Zhihong

    database4,9 in the large energy regime E/T 10 confirmed this theory prediction by showing that the upper of Basic Plasma Physics, University of Science and Technology of China, Hefei, Anhui 230026, China 3 particles energy E to plasma temperature T ratio because of the averaging effects of the large gyroradius

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

    SciTech Connect (OSTI)

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

    2014-03-15T23:59:59.000Z

    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.

  14. The effects of nonthermal electron distributions on ion-temperature-gradient driven drift-wave instabilities in electron-ion plasma

    SciTech Connect (OSTI)

    Batool, Nazia [Theoretical Plasma Physics Group, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan); National Center of Physics (NCP), Quaid-i-Azam University campus, Islamabad (Pakistan); Masood, W. [National Center of Physics (NCP), Quaid-i-Azam University campus, Islamabad (Pakistan); Theoretical Plasma Physics Division, PINSTECH P. O. Nilore, Islamabad (Pakistan); Mirza, Arshad M. [Theoretical Plasma Physics Group, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

    2012-08-15T23:59:59.000Z

    The effects of nonthermal electron distributions on electrostatic ion-temperature-gradient (ITG) driven drift-wave instabilities in the presence of equilibrium density, temperature, and magnetic field gradients are investigated here. By using Braginskii's transport equations for ions and Cairns as well as Kappa distribution for electrons, the coupled mode equations are derived. The modified ITG driven modes are derived, and it is found both analytically as well as numerically that the nonthermal distribution of electrons significantly modify the real frequencies as well as the growth rate of the ITG driven drift wave instability. The growth rate of ion-temperature-gradient driven instability is found to be maximum for Cairns, intermediate for Kappa, and minimum for the Maxwellian distributed electron case. The results of present investigation might be helpful to understand several wave phenomena in space and laboratory plasmas in the presence of nonthermal electrons.

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

    E-Print Network [OSTI]

    Maruyama, Shigeo

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

  16. Fine-Scale Zonal Flow Suppression of Electron Temperature Gradient Turbulence

    E-Print Network [OSTI]

    Lin, Zhihong

    as an explanation for the long time build up of the zonal flow in ETG turbulence and it is shown that the generationFine-Scale Zonal Flow Suppression of Electron Temperature Gradient Turbulence S.E. Parker , J continue to grow algebraically (proportional to time). These fine-scale zonal flows have a radial wave

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

    E-Print Network [OSTI]

    Royer, Dana

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

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

    SciTech Connect (OSTI)

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

    2011-12-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Korosec, Michael A.

    1983-11-01T23:59:59.000Z

    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.

  20. Study of Turbulent Fluctuations Driven by the Electron Temperature Gradient in the National Spherical Torus Experiment

    SciTech Connect (OSTI)

    Mazzucato, E.; Bell, R. E.; Ethier, S.; Hosea, J. C.; Kaye, S. M.; LeBlanc, B. P.; Lee, W. W.; Ryan, P. M.; Smith, D. R.; Wang, W. X.; Wilson, J. R.

    2009-03-26T23:59:59.000Z

    Various theories and numerical simulations support the conjecture that the ubiquitous problem of anomalous electron transport in tokamaks may arise from a short-scale turbulence driven by the electron temperature gradient. To check whether this turbulence is present in plasmas of the National Spherical Torus Experiment (NSTX), measurements of turbulent fluctuations were performed with coherent scattering of electromagnetic waves. Results from plasmas heated by high harmonic fast waves (HHFW) show the existence of density fluctuations in the range of wave numbers k??e=0.1-0.4, corresponding to a turbulence scale length of the order of the collisionless skin depth. Experimental observations and agreement with numerical results from the linear gyro-kinetic GS2 code indicate that the observed turbulence is driven by the electron temperature gradient. These turbulent fluctuations were not observed at the location of an internal transport barrier driven by a negative magnetic shear.

  1. Effect of entropy on anomalous transport in electron-temperature-gradient-modes

    SciTech Connect (OSTI)

    Yaqub Khan, M., E-mail: myaqubsultani@gmail.com [Department of Basic Sciences, Riphah International University, Islamabad 44000 (Pakistan); National Centre for Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Iqbal, J. [Department of Mathematics, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Ul Haq, A. [Faculty of Engineering and Applied Physics, Riphah International University, Islamabad 44000 (Pakistan)

    2014-05-15T23:59:59.000Z

    Due to the interconnection of entropy with temperature and density of plasma, it would be interesting to investigate plasma related phenomena with respect to entropy. By employing Braginskii transport equations, it is proved that entropy is proportional to a function of potential and distribution function of entropy is re-defined, ?S–drift in obtained. New dispersion relation is derived; it is found that the anomalous transport depends on the gradient of the entropy.

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

    SciTech Connect (OSTI)

    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

    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.

  3. The Temperature Prediction in Deepwater Drilling of Vertical Well 

    E-Print Network [OSTI]

    Feng, Ming

    2012-07-16T23:59:59.000Z

    .................................................................................................. 30 3.4 Geothermal Gradient ................................................................................ 30 3.5 Overall Heat Transfer Coefficient ............................................................ 30... for their love and support v ACKNOWLEDGMENTS During these four years at Texas A&M University I have tried my best to adhere to the requirements of being a qualified...

  4. Single-well Low Temperature CO2- based Engineered Geothemal System...

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

    Single-well Low Temperature CO2- based Engineered Geothemal System Single-well Low Temperature CO2- based Engineered Geothemal System Single-well Low Temperature CO2- based...

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

    SciTech Connect (OSTI)

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

    2008-12-15T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    March, Philip Anderson

    1981-01-01T23:59:59.000Z

    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...

  7. Turbulent electron transport in edge pedestal by electron temperature gradient turbulence

    SciTech Connect (OSTI)

    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

    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.

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

    E-Print Network [OSTI]

    Molaro, Jamie L; Langer, Steve A

    2015-01-01T23:59:59.000Z

    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...

  9. The Temperature Prediction in Deepwater Drilling of Vertical Well

    E-Print Network [OSTI]

    Feng, Ming

    2012-07-16T23:59:59.000Z

    The extreme operating conditions in deepwater drilling lead to serious relative problems. The knowledge of subsea temperatures is of prime interest to petroleum engineers and geo-technologists alike. Petroleum engineers are interested in subsea...

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

    SciTech Connect (OSTI)

    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

    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.

  11. Well Productivity Enhancement of High Temperature Heterogeneous Carbonate Reservoirs

    E-Print Network [OSTI]

    Wang, Guanqun

    2014-05-08T23:59:59.000Z

    Acidizing is one of the most popular techniques for well productivity enhancement during oil and gas production. However, the treatment method is not very effective when the wellbore penetrates through multiple layers of heterogeneous reservoirs...

  12. Linear and nonlinear dynamics of electron temperature gradient mode in non-Maxwellian plasmas

    SciTech Connect (OSTI)

    Zakir, U.; Qamar, A. [Institute of Physics and Electronics, University of Peshawar, Peshawar (Pakistan)] [Institute of Physics and Electronics, University of Peshawar, Peshawar (Pakistan); Haque, Q. [Theoretical Plasma Physics Division, PINSTECH, Islamabad (Pakistan) [Theoretical Plasma Physics Division, PINSTECH, Islamabad (Pakistan); National Centre for Physics, Islamabad (Pakistan)

    2013-05-15T23:59:59.000Z

    The effect of non-Maxwellian distributed ions on electron temperature gradient mode is investigated. The linear dispersion relation of ?{sub e}?mode is obtained which shows that the behavior of this mode changes in the presence of superthermal ions. The growth rate of ?{sub e}?mode driven linear instability is found and is observed to modify due to nonthermal ions. However, it is found that this leaves the electron energy transport coefficient unchanged. In the nonlinear regime, a dipolar vortex solution is derived which indicates that the dynamic behavior of the vortices changes with the inclusion of kappa distributed ions. The importance of present study with respect to space and laboratory plasmas is also pointed out.

  13. Bifurcation Theory of the Transition to Collisionless Ion-temperature-gradient-driven Plasma Turbulence

    SciTech Connect (OSTI)

    Kolesnikov, R.A.; Krommes, J.A.

    2005-09-22T23:59:59.000Z

    The collisionless limit of the transition to ion-temperature-gradient-driven plasma turbulence is considered with a dynamical-systems approach. The importance of systematic analysis for understanding the differences in the bifurcations and dynamics of linearly damped and undamped systems is emphasized. A model with ten degrees of freedom is studied as a concrete example. A four-dimensional center manifold (CM) is analyzed, and fixed points of its dynamics are identified and used to predict a ''Dimits shift'' of the threshold for turbulence due to the excitation of zonal flows. The exact value of that shift in terms of physical parameters is established for the model; the effects of higher-order truncations on the dynamics are noted. Multiple-scale analysis of the CM equations is used to discuss possible effects of modulational instability on scenarios for the transition to turbulence in both collisional and collisionless cases.

  14. R655-1-8 Temperature Gradient Wells | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I GeothermalPotentialBiopowerSolidGenerationMethod JumpGeorgia: Energy Resources Jump to:Qubed

  15. Utilizing Distributed Temperature and Pressure Data To Evaluate The Production Distribution in Multilateral Wells

    E-Print Network [OSTI]

    Al Zahrani, Rashad Madees K.

    2012-07-16T23:59:59.000Z

    -intensive and involve operational risks. An alternative way to measure the production from each lateral is to use Distributed Temperature Sensing (DTS) technology. Recent advances in DTS technology enable measuring the temperature profile in horizontal wells with high...

  16. Room-temperature 1.3 pm electroluminescence from strained Si, -,Ge,/Si quantum wells

    E-Print Network [OSTI]

    Room-temperature 1.3 pm electroluminescence from strained Si, -,Ge,/Si quantum wells Q. Mi, X. Xiao report the first room-temperature 1.3 ,um electroluminescence from strained Sir-,Ge,/Si quantum wells to that from the Sit-,GeX wells. A minimum band offset is required to have effective room

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

    E-Print Network [OSTI]

    Archer, Paul Lawrence

    1978-01-01T23:59:59.000Z

    1978) Paul Lawrence Archer, B. S. , The Pennsylvania State University Chairman of Advisory Committee: Andrew Hajash Natural seawater and mid-ocean ridge tholeiitic basalt were allowed to react at 100-500'C, and 1000 bars at water/rock mass ratios... temperature experiments at 500'C and temperature- gradient experiments reacted from 200'C to 500 C 53 57 LIST OF FIGURES Figure Page Graphs of Na, Ca, K, and Mg concentrations in 5/1 and 50/1 seawater/basalt experiments as a function of temperature 17...

  18. Temperature Prediction Model for Horizontal Well with Multiple Fractures in Shale Reservoir

    E-Print Network [OSTI]

    Yoshida, Nozomu

    2013-04-12T23:59:59.000Z

    Fracture diagnostics is a key technology for well performance prediction of a horizontal well in a shale reservoir. The combination of multiple fracture diagnostic techniques gives reliable results, and temperature data has potential to provide more...

  19. Probing temperature gradients within the GaN buffer layer of AlGaN/GaN high electron mobility transistors with Raman thermography

    SciTech Connect (OSTI)

    Hodges, C., E-mail: chris.hodges@bristol.ac.uk; Pomeroy, J.; Kuball, M. [H. H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL (United Kingdom)

    2014-02-14T23:59:59.000Z

    We demonstrate the ability of confocal Raman thermography using a spatial filter and azimuthal polarization to probe vertical temperature gradients within the GaN buffer layer of operating AlGaN/GaN high electron mobility transistors. Temperature gradients in the GaN layer are measured by using offset focal planes to minimize the contribution from different regions of the GaN buffer. The measured temperature gradient is in good agreement with a thermal simulation treating the GaN thermal conductivity as homogeneous throughout the layer and including a low thermal conductivity nucleation layer to model the heat flow between the buffer and substrate.

  20. Numerical Modeling of Cased-hole Instability in High Pressure and High Temperature Wells 

    E-Print Network [OSTI]

    Shen, Zheng 1983-

    2012-11-12T23:59:59.000Z

    of cemented sections in High Pressure High Temperature (HPHT) wells. The existing analysis shows that, in the perforation zones, casing/cement is subject to instability, particularly in the presence of cavities. This dissertation focuses on the instability...

  1. Utilizing Distributed Temperature Sensors in Predicting Flow Rates in Multilateral Wells

    E-Print Network [OSTI]

    Al Mulla, Jassim Mohammed A.

    2012-07-16T23:59:59.000Z

    The new advancement in well monitoring tools have increased the amount of data that could be retrieved with great accuracy. Downhole pressure and temperature could be precisely determined now by using modern instruments. The new challenge that we...

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

    E-Print Network [OSTI]

    Kersting, Roland

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

  3. Evidence of former higher temperatures from alteration minerals, Bostic 1-A well, Mountain Home, Idaho

    SciTech Connect (OSTI)

    Arney, B.

    1982-01-01T23:59:59.000Z

    Cuttings from the silicic volcanics in the Bostic 1-A well near Mountain Home, Idaho have been examined petrographically with the assistance of x-ray diffraction and electron microprobe analyses. Results indicate that these rocks have been subjected to much higher temperatures than were observed in the well in 1974, when a static temperature log was run. It is not known to what extent the alternation may be due to greater depth of burial in the past, or whether it resulted from an early hydrothermal system of higher temperature than the one now observed.

  4. Temperature dependent band offsets in PbSe/PbEuSe quantum well heterostructures

    SciTech Connect (OSTI)

    Simma, M.; Bauer, G.; Springholz, G. [Institut fuer Halbleiter und Festkoerperphysik, Johannes Kepler Universitaet, A-4040 Linz (Austria)

    2012-10-22T23:59:59.000Z

    The band offsets of PbSe/Pb{sub 1-x}Eu{sub x}Se multi-quantum wells grown by molecular beam epitaxy are determined as a function of temperature and europium content using temperature-modulated differential transmission spectroscopy. The confined quantum well states in the valence and conduction bands are analyzed using a k{center_dot}p model with envelope function approximation. From the fit of the experimental data, the normalized conduction band offset is determined as 0.45{+-}0.15 of the band gap difference, independently of Eu content up to 14% and temperature from 20 to 300 K.

  5. Temperature stability of intersubband transitions in AlN/GaN quantum wells

    SciTech Connect (OSTI)

    Berland, Kristian; Stattin, Martin; Farivar, Rashid; Sultan, D. M. S.; Hyldgaard, Per; Larsson, Anders; Wang, Shu Min; Andersson, Thorvald G. [Department of Microtechnology and Nanoscience, MC2, Chalmers University of Technology, SE-41296 Goeteborg (Sweden)

    2010-07-26T23:59:59.000Z

    Temperature dependence of intersubband transitions in AlN/GaN multiple quantum wells grown with molecular beam epitaxy is investigated both by absorption studies at different temperatures and modeling of conduction-band electrons. For the absorption study, the sample is heated in increments up to 400 deg. C. The self-consistent Schroedinger-Poisson modeling includes temperature effects of the band gap and the influence of thermal expansion on the piezoelectric field. We find that the intersubband absorption energy decreases only by approx6 meV at 400 deg. C relative to its room temperature value.

  6. Temperature-dependent quantum efficiency of Ga(N,As,P) quantum wells

    SciTech Connect (OSTI)

    Rosemann, N. W., E-mail: Nils.Rosemann@Physik.Uni-Marburg.de; Metzger, B.; Volz, K.; Chatterjee, S. [Faculty of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, D-35032 Marburg (Germany)] [Faculty of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, D-35032 Marburg (Germany); Kunert, B. [NAsP III/V GmbH, Am Knechtacker 19, D-35041 Marburg (Germany)] [NAsP III/V GmbH, Am Knechtacker 19, D-35041 Marburg (Germany); Stolz, W. [Faculty of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, D-35032 Marburg (Germany) [Faculty of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, D-35032 Marburg (Germany); NAsP III/V GmbH, Am Knechtacker 19, D-35041 Marburg (Germany)

    2013-12-16T23:59:59.000Z

    The photoluminescence quantum efficiencies of a series of Ga(N,As,P)/GaP multiple quantum wells are analyzed. The external quantum efficiencies are derived from the absorbed and the emitted light intensities measured using an integrating sphere mounted inside a closed-cycle helium cryostat. By taking into account the device layer sequences as well as internal reflections and reabsorption, the internal quantum efficiencies yield values above 90% for all samples at cryogenic temperatures. The temperature-dependence of the quantum efficiencies as a function of active quantum well layer design reveal the internal interfaces as remaining growth challenge in these heterostructures.

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

    E-Print Network [OSTI]

    . If a hot reservoir and a cold sink are separated by a straight wall of thickness L within the plane of position. The principle we adopt for designing linear temperature control into an on-chip device15 rests

  8. High resolution InSb quantum well ballistic nanosensors for room temperature applications

    SciTech Connect (OSTI)

    Gilbertson, Adam; Cohen, L. F. [Blackett Laboratory, Imperial College London, SW7 2BZ (United Kingdom); Lambert, C. J. [Department of Physics, Lancaster University, Lancaster, LA1 4YB (United Kingdom); Solin, S. A. [Department of Physics, Washington University in St. Louis, St. Louis, Missouri 63130 (United States)

    2013-12-04T23:59:59.000Z

    We report the room temperature operation of a quasi-ballistic InSb quantum well Hall sensor that exhibits a high frequency sensitivity of 560nT/?Hz at 20uA bias current. The device utilizes a partitioned buffer layer design that suppresses leakage currents through the mesa floor and can sustain large current densities.

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

    E-Print Network [OSTI]

    Goeking, Kent Wayne

    1987-01-01T23:59:59.000Z

    temperature and Curie point ill KTN compositional analysis . 29 . 30 Ix LIST OF FIGURES FIGURE Page Cubic perovskite structure - paraelectric phase. Tetragonal distorted perovskite structure - ferroelectric phase. . . 3 Ferroelectric polarization vs..., this material was found to display ferroelectric behavior. Unlike early ferroelectrics, BaTIOs had a simple cubic centrosymmetric perovskite structure that allowed extensive investigation into the mechanics of ferroelectricity. Following this discovery...

  10. 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

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

    SciTech Connect (OSTI)

    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

    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.

  12. Modelling of ultrasonic propagation in turbulent liquid sodium with temperature gradient

    SciTech Connect (OSTI)

    Massacret, N. [CEA, DEN, Nuclear Technology Department, F-13108 Saint-Paul-Lez-Durance (France); Aix-Marseille Université, LMA UPR 7051 CNRS, site LCND, 13625 Aix-en-Provence (France); Moysan, J., E-mail: joseph.moysan@univ-amu.fr; Ploix, M. A.; Corneloup, G. [Aix-Marseille Université, LMA UPR 7051 CNRS, site LCND, 13625 Aix-en-Provence (France); Jeannot, J. P. [CEA, DEN, Nuclear Technology Department, F-13108 Saint-Paul-Lez-Durance (France)

    2014-05-28T23:59:59.000Z

    The use of ultrasonic instrumentation in sodium-cooled fast reactors requires to understand and to predict how ultrasonic waves can be deflected, slowed down or speeded up, depending on the thermo-hydraulic characteristics of the liquid sodium. These thermo-hydraulic characteristics are mainly the local temperature and flow speed of the sodium. In this study we show that ray theory can be used to simulate ultrasonic propagation in a medium similar to the core of a sodium-cooled fast reactor, in order to study ultrasonic instrumentation and prepare it installation and utilisation in the sodium of the nuclear reactor. A suitable model has been developed and a set of thermo-hydraulics data has been created, taking account of the particularities of the sodium flow. The results of these simulations are then analysed within the framework of acoustic thermometry, in order to determine which disturbance must be taken into account for the correct operation of the temperature measurement.

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

    SciTech Connect (OSTI)

    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

    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.

  14. Low temperature carrier redistribution dynamics in InGaN/GaN quantum wells

    SciTech Connect (OSTI)

    Badcock, T. J., E-mail: Thomas.badcock@crl.toshiba.co.uk; Dawson, P.; Davies, M. J. [School of Physics and Astronomy, Photon Science Institute, Alan Turing Building, University of Manchester, Manchester M13 9PL (United Kingdom); Kappers, M. J.; Massabuau, F. C.-P.; Oehler, F.; Oliver, R. A.; Humphreys, C. J. [Department of Materials Science and Metallurgy, 27 Charles Babbage Road, University of Cambridge, Cambridge CB3 0FS (United Kingdom)

    2014-03-21T23:59:59.000Z

    We have studied the carrier recombination dynamics in an InGaN/GaN multiple quantum well structure as a function of emission energy and excitation density between temperatures of 10?K and 100?K. Under relatively low levels of excitation, the photoluminescence (PL) intensity and decay time of emission on the high energy side of the luminescence spectrum decrease strongly between 10?K and 50?K. In contrast, for emission detected on the low energy side of the spectrum, the PL intensity and decay time increase over the same temperature range. These results are consistent with a thermally activated carrier redistribution process in which the (temperature dependent) average timescale for carrier transfer into or out of a localised state depends on the energy of the given state. Thus, the transfer time out of shallow, weakly localised states is considerably shorter than the arrival time into more deeply localised states. This picture is consistent with carriers hopping between localisation sites in an uncorrelated disorder potential where the density of localised states decreases with increasing localisation depth, e.g., a exponential or Gaussian distribution resulting from random alloy disorder. Under significantly higher levels of excitation, the increased occupation fraction of the localised states results in a greater average separation distance between unoccupied localised states, causing a suppression of the spectral and dynamic signatures of the hopping transfer of carriers.

  15. 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 |...

  16. Utilizing Distributed Temperature Sensors in Predicting Flow Rates in Multilateral Wells 

    E-Print Network [OSTI]

    Al Mulla, Jassim Mohammed A.

    2012-07-16T23:59:59.000Z

    gradient. Thus the need of accurate and high precision gauges becomes critical. The trade-off of high resolution sensors is the related cost and resulting complication in modeling. Interpreting measured data at real-time to a downhole flow profile...

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

    E-Print Network [OSTI]

    Kadri, Romi Sinclair

    2014-01-01T23:59:59.000Z

    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 ...

  18. Monitoring temperature conditions in recently drilled nonproductive industry boreholes in Oklahoma

    SciTech Connect (OSTI)

    Harrison, W.E.; Luza, K.V.

    1985-06-01T23:59:59.000Z

    Temperature conditions were monitored in seven industry petroleum-test wells (called holes-of-opportunity in this report) that were drilled in central and eastern Oklahoma. Five of these wells provided useful temperature information, and two wells were used to determine the length of time needed for the borehole-fluid temperature to achieve thermal equilibrium with the formation rocks. Four wells were used to verify the validity of a geothermal-gradient map of Oklahoma. Temperature surveys in two wells indicated a gradient lower than the predicted gradients on the geothermal-gradient map. When deep temperature data, between 5000 and 13,000 feet, are adjusted for mud-circulation effects, the adjusted gradients approximate the gradients on the geothermal-gradient map. The temperature-confirmation program appears to substantiate the geographic distribution of the high- and low-thermal-gradient regimes in Oklahoma. 13 refs., 18 figs., 7 tabs.

  19. High Temperature, High Pressure Devices for Zonal Isolation in Geothermal Wells

    Broader source: Energy.gov [DOE]

    DOE Geothermal Peer Review 2010 - Presentation. Project objectives: Design, demonstrate, and qualify high-temperature high pressure zonal isolation devices compatible with the high temperature downhole Enhanced Geothermal Systems (EGS) environment.

  20. High-Temperature Circuit Boards for Use in Geothermal Well Monitoring Applications

    Broader source: Energy.gov [DOE]

    Project objective: Develop and demonstrate high-temperature; multilayer electronic circuits capable of sustained operation at 300? C.

  1. High-Temperature Circuit Boards for Use in Geothermal Well Monitoring...

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

    Technology Development, Inc. High-Temperature Tools and Sensors, Downhole Pumps and Drilling May 19, 2010 This presentation does not contain any proprietary confidential, or...

  2. Detecting and modeling cement failure in high pressure/ high temperature wells using finite-element method

    E-Print Network [OSTI]

    Shahri, Mehdi Abbaszadeh

    2006-04-12T23:59:59.000Z

    conditions and are investigated simultaneously to more accurately predict cement failure. The results of this study show the relevant dependency of stress principles with temperature and pressure. These results clarify the deformation caused by any...

  3. Low temperature barriers with heat interceptor wells for in situ processes

    DOE Patents [OSTI]

    McKinzie, II, Billy John (Houston, TX)

    2008-10-14T23:59:59.000Z

    A system for reducing heat load applied to a frozen barrier by a heated formation is described. The system includes heat interceptor wells positioned between the heated formation and the frozen barrier. Fluid is positioned in the heat interceptor wells. Heat transfers from the formation to the fluid to reduce the heat load applied to the frozen barrier.

  4. Systematic study of different transitions in high operating temperature quantum dots in a well photodetectors

    E-Print Network [OSTI]

    Krishna, Sanjay

    . For example, the readout integrated circuit poses significant limitations on the maximum applied bias, maximum 1 Center for High Technology Materials, University of New Mexico, Albuquerque, New Mexico 87106, USA to large volume low cost infrared imaging systems. High operating temperature allows system design- ers

  5. Detecting and modeling cement failure in high pressure/ high temperature wells using finite-element method 

    E-Print Network [OSTI]

    Shahri, Mehdi Abbaszadeh

    2006-04-12T23:59:59.000Z

    A successful cement job results in complete zonal isolation while saving time and money. To achieve these goals, various factors such as well security, casing centralization, effective mud removal, and gas migration must be considered in the design...

  6. High-Temperature Circuit Boards for use in Geothermal Well Monitoring

    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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdfGetecGtel Jump to: navigation, search Name:HidraliaWells GeothermalApplications

  7. Low-temperature geothermal water in Utah: A compilation of data for thermal wells and springs through 1993

    SciTech Connect (OSTI)

    Blackett, R.E.

    1994-07-01T23:59:59.000Z

    The Geothermal Division of DOE initiated the Low-Temperature Geothermal Resources and Technology Transfer Program, following a special appropriation by Congress in 1991, to encourage wider use of lower-temperature geothermal resources through direct-use, geothermal heat-pump, and binary-cycle power conversion technologies. The Oregon Institute of Technology (OIT), the University of Utah Research Institute (UURI), and the Idaho Water Resources Research Institute organized the federally-funded program and enlisted the help of ten western states to carry out phase one. This first phase involves updating the inventory of thermal wells and springs with the help of the participating state agencies. The state resource teams inventory thermal wells and springs, and compile relevant information on each sources. OIT and UURI cooperatively administer the program. OIT provides overall contract management while UURI provides technical direction to the state teams. Phase one of the program focuses on replacing part of GEOTHERM by building a new database of low- and moderate-temperature geothermal systems for use on personal computers. For Utah, this involved (1) identifying sources of geothermal date, (2) designing a database structure, (3) entering the new date; (4) checking for errors, inconsistencies, and duplicate records; (5) organizing the data into reporting formats; and (6) generating a map (1:750,000 scale) of Utah showing the locations and record identification numbers of thermal wells and springs.

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

    E-Print Network [OSTI]

    Archer, Paul Lawrence

    1978-01-01T23:59:59.000Z

    in the precipitation of Fe-sulfides (pyri te and pyrrhoti te) in both 5/1 and 50/1 water/rock ratio systems. As a result of this precipitation, Fe was effectively fractionated from Mn and the Fe/Mn ratio of the fluid decreased. Because the 50/1 systems had lower pH.... EPR). This investi- gation also provides data potentially useful in predicting the occur- rence and kind of mineralization at ocean spreading centers as a function of the temperature and water/rock ratio regime of that system. 11 METHODS Ex...

  9. Analysis of effect of temperature gradients on surface-tension phenomena in gas-tungsten-arc welds

    SciTech Connect (OSTI)

    Lee, H.A.; Chien, P.S.J.

    1982-10-01T23:59:59.000Z

    Fluid motion directed by surface tension is considered as a contributor to heat penetration in a weld pool. The potential phenomena at the gas-liquid interface were analyzed, and the dependence of surface motion on temperature in the gas-tungsten-arc (GTA) welding process was examined. An existing heat-transfer model was used and was able to predict weld size to +- 50% of the actual value. A momentum-transfer equation was derived by considering the contribution of Lorentz force. The momentum boundary condition was developed and was able to predict the Marangoni effect. The magnitude of surface-tension-driven force is comparable to the gravitational force on one gram. An empirical approach was proposed to couple heat-transfer and momentum-transfer phenomena. A dimensional analysis identified the pertinent dimensionless groups as Reynolds, Weber, Froude, Peclet, and Power numbers and a dimensionless velocity. A simplified form of the correction was developed by combining dimensionless groups to yield a correlation with the Bond, Prandtl, and modified power numbers. Future experimental work was proposed to test the functionality of the dimensionless groups.

  10. Hypoxia is well known to reduce metabolism and body temperature in many vertebrates (Wood and Gonzales, 1996),

    E-Print Network [OSTI]

    Tattersall, Glenn

    using infrared thermography to measure the surface temperatures of the golden-mantled ground squirrel

  11. Core-shell multi-quantum wells in ZnO / ZnMgO nanowires with high optical efficiency at room temperature

    E-Print Network [OSTI]

    Thierry, Robin; Jouneau, Pierre-Henri; Ferret, Pierre; Feuillet, Guy; 10.1088/0957-4484/23/8/085705

    2013-01-01T23:59:59.000Z

    Nanowire-based light-emitting devices require multi-quantum well heterostructures with high room temperature optical efficiencies. We demonstrate that such efficiencies can be attained through the use of ZnO/Zn(1-x)MgxO core shell quantum well heterostructures grown by metal organic vapour phase epitaxy. Varying the barrier Mg concentration from x=0.15 to x=0.3 leads to the formation of misfit induced dislocations in the multi quantum wells. Correlatively, temperature dependant photoluminescence reveals that the radial well luminescence intensity decreases much less rapidly with increasing temperature for the lower Mg concentration. Indeed, about 54% of the 10K intensity is retained at room temperature with x=0.15, against 2% with x=0.30. Those results open the way to the realization of high optical efficiency nanowire-based light emitting diodes.

  12. Influence of temperature on the mechanism of carrier injection in light-emitting diodes based on InGaN/GaN multiple quantum wells

    SciTech Connect (OSTI)

    Prudaev, I. A., E-mail: jaia@pochta.ru; Golygin, I. Yu.; Shirapov, S. B.; Romanov, I. S.; Khludkov, S. S.; Tolbanov, O. P. [Tomsk State University (Russian Federation)] [Tomsk State University (Russian Federation)

    2013-10-15T23:59:59.000Z

    The experimental current-voltage characteristics and dependences of the external quantum yield on the current density of light-emitting diodes based on InGaN/GaN multiple quantum wells for the wide temperature range T = 10-400 K are presented. It is shown that, at low-temperatures T < 100 K, the injection of holes into the quantum wells occurs from localized acceptor states. The low-temperature injection of electrons into p-GaN occurs due to quasi-ballistic transport in the region of multiple quantum wells. An increase in temperature leads to an increase in the current which is governed by thermally activated hole and electron injection from the allowed bands of GaN.

  13. Sub-100 A current operation of strained InGaAs quantum well lasers at low temperatures

    E-Print Network [OSTI]

    . R. Chen, L. E. Eng, Y. H. Zhuang, A. Shakouri, and A. Yariv T. J. Watson Sr. Laboratories of Applied A and external quantum efficiency 1 mW/mA have been demonstrated under cw operation condition at temperatures

  14. Effects of bias and temperature on the intersubband absorption in very long wavelength GaAs/AlGaAs quantum well infrared photodetectors

    SciTech Connect (OSTI)

    Liu, X. H.; Zhou, X. H., E-mail: xhzhou@mail.sitp.ac.cn; Li, N.; Liao, K. S.; Huang, L.; Li, Q.; Li, Z. F.; Chen, P. P.; Lu, W. [National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu-Tian Road, Shanghai 200083 (China); Wang, L.; Sun, Q. L. [Institute of Physics, Chinese Academy of Sciences, Beijing 100080 (China)

    2014-03-28T23:59:59.000Z

    The temperature- and bias-dependent photocurrent spectra of very long wavelength GaAs/AlGaAs quantum well infrared photodetectors (QWIPs) are studied using spectroscopic measurements and corresponding theoretical calculations. It is found that the peak response wavelength will shift as the bias and temperature change. Aided by band structure calculations, we propose a model of the double excited states and explain the experimental observations very well. In addition, the working mechanisms of the quasi-bound state confined in the quantum well, including the processes of tunneling and thermionic emission, are also investigated in detail. We confirm that the first excited state, which belongs to the quasi-bound state, can be converted into a quasi-continuum state induced by bias and temperature. These obtained results provide a full understanding of the bound-to-quasi-bound state and the bound-to-quasi-continuum state transition, and thus allow for a better optimization of QWIPs performance.

  15. Gradient elution in capillary electrochromatography

    SciTech Connect (OSTI)

    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

    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.

  16. Introduction Conjugate Gradient Method

    E-Print Network [OSTI]

    Vuik, Kees

    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

  17. Complete Fiber/Copper Cable Solution for Long-Term Temperature and Pressure Measurement in Supercritical Reservoirs and EGS Wells

    Broader source: Energy.gov [DOE]

    Project objectives: 1. Optical fibers that resist hydrogen Ťdarkening? for several months instead of hours and days at 300 deg. C and higher. 2. Tube encapsulated cable (TEC) construction that functions as a distributed temperature sensor (DTS) and a power source for a downhole pressure sensor.

  18. Relationships between geology and geothermal gradients in Kansas

    SciTech Connect (OSTI)

    Stavnes, S.A.; Steeples, D.W.; Ruscetta, C.A. (ed.)

    1982-07-01T23:59:59.000Z

    Bottom hole temperature values from existing oil and gas wells and thermal logging data from geothermal wells are used to determine the factors responsible for geographic variation in the subsurface temperature distribution in Kansas. Geothermal gradient data range from 25/sup 0/C/km to 55/sup 0/C/km in the upper 300 m. The geologic factors proposed to explain this variation are: (1) topography of the crystalline basement surface; (2) variation in rates of heat production in the crystalline basement; (3) variation in thermal conductivity in the sedimentary section; and (4) possible convection upward and eastward from the Denver-Julesberg Basin. (MJF)

  19. Geosynthetics in a salinity-gradient solar pond environment

    SciTech Connect (OSTI)

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

    1997-11-01T23:59:59.000Z

    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.

  20. In situ X-ray investigation of changing barrier growth temperatures on InGaN single quantum wells in metal-organic vapor phase epitaxy

    SciTech Connect (OSTI)

    Ju, Guangxu, E-mail: g-ju@nuee.nagoya-u.ac.jp; Honda, Yoshio [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603 (Japan); Tabuchi, Masao [Synchrotron Radiation Research Centre, Nagoya University, Nagoya, Aichi 464-8603 (Japan); Takeda, Yoshikazu [Synchrotron Radiation Center, Aichi Science and Technology Foundation, Seto, Aichi 489-0965 (Japan); Nagoya Industrial Science Research Institute, Nagoya, Aichi 464-0819 (Japan); Amano, Hiroshi [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603 (Japan); Akasaki Research Center, Nagoya University, Aichi 464-8603 (Japan)

    2014-03-07T23:59:59.000Z

    The effects of GaN quantum barriers with changing growth temperatures on the interfacial characteristics of GaN/InGaN single quantum well (SQW) grown on GaN templates by metalorganic vapour phase epitaxy were in situ investigated by X-ray crystal truncation rod (CTR) scattering and X-ray reflectivity measurements at growth temperature using a laboratory level X-ray diffractometer. Comparing the curve-fitting results of X-ray CTR scattering spectra obtained at growth temperature with that at room temperature, the In{sub x}Ga{sub 1-x}N with indium composition less than 0.11 was stabile of the indium distribution at the interface during the whole growth processes. By using several monolayers thickness GaN capping layer to protect the InGaN well layer within temperature-ramping process, the interfacial structure of the GaN/InGaN SQW was drastically improved on the basis of the curve-fitting results of X-ray CTR scattering spectra, and the narrow full width at half-maximum and strong luminous intensity were observed in room temperature photoluminescence spectra.

  1. Junction Temperature Measurements and Thermal Modeling of GaInN/GaN Quantum Well Light-Emitting Diodes

    E-Print Network [OSTI]

    Wetzel, Christian M.

    quantum well (QW) light-emitting diodes (LEDs) grown on sapphire and bulk GaN substrate by micro efficiency in dies grown on GaN substrates with a thermal resistance of 75 K/W. For dies on sapphire of GaN-based blue and green LEDs grown on sapphire and GaN substrates using micro-Raman spectroscopy

  2. Room-temperature mid-infrared “M”-type GaAsSb/InGaAs quantum well lasers on InP substrate

    SciTech Connect (OSTI)

    Chang, Chia-Hao; Li, Zong-Lin; Pan, Chien-Hung; Lu, Hong-Ting; Lee, Chien-Ping; Lin, Sheng-Di, E-mail: sdlin@mail.nctu.edu.tw [Department of Electronics Engineering, National Chiao Tung University, 1001 University Road, Hsinchu 30010, Taiwan (China)

    2014-02-14T23:59:59.000Z

    We have demonstrated experimentally the InP-based “M”-type GaAsSb/InGaAs quantum-well (QW) laser lasing at 2.41??m at room temperature by optical pumping. The threshold power density per QW and extracted internal loss were about 234?W/cm{sup 2} and 20.5?cm{sup ?1}, respectively. The temperature-dependent photoluminescence (PL) and lasing spectra revealed interesting characteristics for this type of lasers. Two distinct regions in the temperature dependent threshold behavior were observed and the transition temperature was found to coincide with the cross over point of the PL and lasing emission peaks. The current-voltage characteristic of “M”-type QW laser was superior to the inverse “W”-type one due to its thinner barrier for holes. Further improvement of the “M”-type QW structure could lead to a cost-effective mid-infrared light source.

  3. Evidence Estimation for Bayesian Partially Observed MRFs Yutian Chen Max Welling

    E-Print Network [OSTI]

    Welling, Max

    (2006) use Langevin dynamics with approximate gradients, Welling and Parise (2006); Parise and Welling

  4. Geothermal potential of West-Central New Mexico from geochemical and thermal gradient data

    SciTech Connect (OSTI)

    Levitte, D.; Gambill, D.T.

    1980-11-01T23:59:59.000Z

    To study the low temperature and Hot Dry Rock (HDR) geothermal potential of west-central New Mexico, 46 water samples were collected and geothermal gradient measurements were made in 29 wells. Water chemistry data indicate that all the samples collected are meteoric waters. High temperatures of samples taken from wells between Gallup and Tohatchi indicate these wells may derive water from a warm aquifer below the depth of the wells. The chemistries of the samples farther south on the Zuni Indian reservation suggest these waters are not circulating below 600 m of the surface. Geothermometry calculations support the conclusion that the waters sampled are meteoric. The geothermometry also indicates that the deep reservoir between Gallup and Tohatchi may be greater than 60/sup 0/C. Thermal gradient data indicate an area of high gradient on the Zuni Indian Reservation with a measured maximum of 67/sup 0/C/km between 181 m and 284 m. This high probably is not hydrologically controlled. The maximum gradients in the study area are 76/sup 0/C/km and 138/sup 0/C/km, measured just east of Springerville, Arizona. These gradients are undoubtedly controlled by circulating water, possibly heated by a magmatic source at depth and circulating back to the surface.

  5. Geothermal gradient map of the conterminous United States. Second edition

    SciTech Connect (OSTI)

    Kron, A.; Stix, J.

    1982-01-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Anders Forsgren

    2013-02-09T23:59:59.000Z

    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 ...

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

    SciTech Connect (OSTI)

    Olander, D.R.

    1984-08-01T23:59:59.000Z

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

  8. Magnetic and dielectric behavior of the spin-chain compound Er{sub 2}BaNiO{sub 5} well below its Néel temperature

    SciTech Connect (OSTI)

    Basu, Tathamay; Singh, Kiran; Sampathkumaran, E. V. [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005 (India); Mohapatra, N. [School of Basic Sciences, Indian Institute of Technology Bhubaneshwar, Bhubaneshwar 751013 (India)

    2014-09-21T23:59:59.000Z

    We have recently reported that the Haldane spin-chain system, Er{sub 2}BaNiO{sub 5}, undergoing antiferromagnetic order below (T{sub N}=) 32?K, is characterized by the onset of ferroelectricity near 60?K due to magnetoelectric coupling induced by short-range magnetic-order within spin-chains. We have carried out additional magnetic and dielectric studies to understand the properties well below T{sub N}. We emphasize here on the following: (i) A strong frequency dependent behaviors of ac magnetic susceptibility and complex dielectric properties have been observed at much lower temperatures (<8?K), that is, “reentrant multiglass-like” phenomenon, naturally suggesting the existence of an additional transition well below T{sub N}. (ii) “Magnetoelectric phase coexistence” is observed at very low temperature (e.g., T?=?2?K), where the high-field magnetoelectric phase is partially arrested on returning to zero magnetic field after a cycling through metamagnetic transition.

  9. 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)

    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

    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.

  10. The ISO Galactic Metallicity Gradient Revisited

    E-Print Network [OSTI]

    Uriel Giveon; Christophe Morisset; Amiel Sternberg

    2002-07-22T23:59:59.000Z

    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.

  11. ON THE CONNECTION BETWEEN THE CONJUGATE GRADIENT METHOD AND

    E-Print Network [OSTI]

    Forsgren, Anders

    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

  12. APPROXIMATE INVERSE PRECONDITIONING FOR THE CONJUGATE GRADIENT METHOD

    E-Print Network [OSTI]

    Tůma, Miroslav

    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

  13. Program predicts two-phase pressure gradients

    SciTech Connect (OSTI)

    Jacks, D.C.; Hill, A.D.

    1983-11-18T23:59:59.000Z

    The calculator program discussed, ORK, was designed for the HP-41CV hand-held calculator and uses the Orkiszewski correlation for predicting 2-phase pressure gradients in vertical tubulars. Accurate predictions of pressure gradients in flowing and gas lift wells over a wide range of well conditions can be obtained with this method, which was developed based on data from 148 wells. The correlation is one of the best generalized 2-phase pressure gradient prediction methods developed to date for vertical flow. It is unique in that hold-up is derived from observed physical phenomena, and the pressure gradient is related to the geometrical distribution of the liquid and gas phase (flow regime).

  14. Variable metric conjugate gradient methods

    SciTech Connect (OSTI)

    Barth, T.; Manteuffel, T.

    1994-07-01T23:59:59.000Z

    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.

  15. Observation of room temperature optical absorption in InP/GaAs type-II ultrathin quantum wells and quantum dots

    SciTech Connect (OSTI)

    Singh, S. D., E-mail: devsh@rrcat.gov.in; Porwal, S.; Mondal, Puspen; Srivastava, A. K.; Mukherjee, C.; Dixit, V. K.; Sharma, T. K.; Oak, S. M. [Raja Ramanna Centre for Advanced Technology, Indore-452013, Madhya Pradesh (India)

    2014-06-14T23:59:59.000Z

    Room temperature optical absorption process is observed in ultrathin quantum wells (QWs) and quantum dots (QDs) of InP/GaAs type-II band alignment system using surface photovoltage spectroscopy technique, where no measurable photoluminescence signal is available. Clear signature of absorption edge in the sub band gap region of GaAs barrier layer is observed for the ultrathin QWs and QDs, which red shifts with the amount of deposited InP material. Movement of photogenerated holes towards the sample surface is proposed to be the main mechanism for the generation of surface photovoltage in type-II ultrathin QWs and QDs. QDs of smaller size are found to be free from the dislocations as confirmed by the high resolution transmission electron microscopy images.

  16. Converting Level Set Gradients to Shape Gradients

    E-Print Network [OSTI]

    Radke, Rich

    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

  17. 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...

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

    E-Print Network [OSTI]

    Zhang, Yuwen

    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

  19. Multi-gradient drilling method and system

    DOE Patents [OSTI]

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

    2003-01-01T23:59:59.000Z

    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.

  20. Exploratory Well At North Brawley Geothermal Area (Matlick &...

    Open Energy Info (EERE)

    Exploration Basis Deep exploratory wells were drilled after a phase of thermal gradient wells helped narrow down the best drilling targets. This activity was done for initial...

  1. 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

  2. Pumpernickel Valley Geothermal Project Thermal Gradient Wells | 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 onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I GeothermalPotentialBiopowerSolidGenerationMethod Jump to:ThisPublic PowerKentucky: EnergyPulte

  3. HIGH GRADIENT INDUCTION ACCELERATOR

    SciTech Connect (OSTI)

    Caporaso, G J; Sampayan, S; Chen, Y; Blackfield, D; Harris, J; Hawkins, S; Holmes, C; Krogh, M; Nelson, S; Nunnally, W; Paul, A; Poole, B; Rhodes, M; Sanders, D; Selenes, K; Sullivan, J; Wang, L; Watson, J

    2007-06-21T23:59:59.000Z

    A new type of compact induction accelerator is under development at the Lawrence Livermore National Laboratory that promises to increase the average accelerating gradient by at least an order of magnitude over that of existing induction machines. The machine is based on the use of high gradient vacuum insulators, advanced dielectric materials and switches and is stimulated by the desire for compact flash x-ray radiography sources. Research describing an extreme variant of this technology aimed at proton therapy for cancer will be described. Progress in applying this technology to several applications will be reviewed.

  4. Inboard and outboard radial electric field wells in the H- and I-mode pedestal of Alcator C-Mod and poloidal variations of impurity temperature

    E-Print Network [OSTI]

    Landreman, M.

    We present inboard (HFS) and outboard (LFS) radial electric field (E[subscript r]) and impurity temperature (T[subscript z]) measurements in the I-mode and H-mode pedestal of Alcator C-Mod. These measurements reveal strong ...

  5. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-f <Maintained ByManagement Inc Place:InformationTelluricConventions

  6. Hanford wells

    SciTech Connect (OSTI)

    Chamness, M.A.; Merz, J.K.

    1993-08-01T23:59:59.000Z

    Records describing wells located on or near the Hanford Site have been maintained by Pacific Northwest Laboratory and the operating contractor, Westinghouse Hanford Company. In support of the Ground-Water Surveillance Project, portions of the data contained in these records have been compiled into the following report, which is intended to be used by those needing a condensed, tabular summary of well location and basic construction information. The wells listed in this report were constructed over a period of time spanning almost 70 years. Data included in this report were retrieved from the Hanford Envirorunental Information System (HEIS) database and supplemented with information not yet entered into HEIS. While considerable effort has been made to obtain the most accurate and complete tabulations possible of the Hanford Site wells, omissions and errors may exist. This document does not include data on lithologic logs, ground-water analyses, or specific well completion details.

  7. Polyelectrolyte Complex Nanoparticles for Protection and Delayed Release of Enzymes in Alkaline pH and at Elevated Temperature during Hydraulic Fracturing of Oil Wells

    E-Print Network [OSTI]

    Barati Ghahfarokhi, Reza; Johnson, Stephen J.; McCool, Stan; Green, Don W.; Willhite, G. Paul; Liang, Jenn-Tai

    2012-01-01T23:59:59.000Z

    Polyethylenimine-dextran sulfate polyelectrolyte complexes (PEC) were used to entrap two enzymes used to degrade polymer gels following hydraulic fracturing of oil wells in order to obtain delayed release and to protect ...

  8. WORLD RECORD ACCELERATING GRADIENT ACHIEVED IN A SUPERCONDUCTING NIOBIUM RF CAVITY

    E-Print Network [OSTI]

    Geng, Rong-Li

    WORLD RECORD ACCELERATING GRADIENT ACHIEVED IN A SUPERCONDUCTING NIOBIUM RF CAVITY R.L. Geng On November 16, 2004, a CW accelerating gradient of 46 MV/m was achieved in a superconducting niobium cav- ity/m was achieved. This represents a world record gradient in a niobium RF resonator. At a reduced temperature of 1

  9. Conjugate Gradient Methods in Confirmatory Factor Analysis

    E-Print Network [OSTI]

    Jamshardian, Mortaza; Jennrich, Robert

    1993-01-01T23:59:59.000Z

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

  10. Conjugate Gradient Acceleration of the EM Algorithm

    E-Print Network [OSTI]

    Mortaza Jamshidian; Robert Jennrich

    2011-01-01T23:59:59.000Z

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

  11. Dimensions of Wellness Staying Well

    E-Print Network [OSTI]

    Fernandez, Eduardo

    to protect your physical health by eating a well-balanced diet, getting plenty of physical activity-evaluation and self-assessment. Wellness involves continually learning and making changes to enhance your state) A state in which your mind is engaged in lively interaction with the world around you. Intellectual

  12. Geothermal well stimulation

    SciTech Connect (OSTI)

    Sinclair, A.R.; Pittard, F.J.; Hanold, R.J.

    1980-01-01T23:59:59.000Z

    All available data on proppants and fluids were examined to determine areas in technology that need development for 300 to 500/sup 0/F (150/sup 0/ to 265/sup 0/C) hydrothermal wells. While fluid properties have been examined well into the 450/sup 0/F range, proppants have not been previously tested at elevated temperatures except in a few instances. The latest test data at geothermal temperatures is presented and some possible proppants and fluid systems that can be used are shown. Also discussed are alternative stimulation techniques for geothermal wells.

  13. Growths of staggered InGaN quantum wells light-emitting diodes emitting at 520525 nm employing graded growth-temperature profile

    E-Print Network [OSTI]

    Gilchrist, James F.

    Growths of staggered InGaN quantum wells light-emitting diodes emitting at 520­525 nm employing current spreading and light extraction in GaN-based light emitting diodes Appl. Phys. Lett. 100, 061107 (2012) Electrically driven nanopyramid green light emitting diode Appl. Phys. Lett. 100, 061106 (2012

  14. Monitoring well

    DOE Patents [OSTI]

    Hubbell, Joel M. (Idaho Falls, ID); Sisson, James B. (Idaho Falls, ID)

    1999-01-01T23:59:59.000Z

    A monitoring well including a conduit defining a passageway, the conduit having a proximal and opposite, distal end; a coupler connected in fluid flowing relationship with the passageway; and a porous housing borne by the coupler and connected in fluid flowing relation thereto.

  15. Monitoring well

    DOE Patents [OSTI]

    Hubbell, J.M.; Sisson, J.B.

    1999-06-29T23:59:59.000Z

    A monitoring well is described which includes: a conduit defining a passageway, the conduit having a proximal and opposite, distal end; a coupler connected in fluid flowing relationship with the passageway; and a porous housing borne by the coupler and connected in fluid flowing relation thereto. 8 figs.

  16. Isobaric groundwater well

    DOE Patents [OSTI]

    Hubbell, Joel M. (Idaho Falls, ID); Sisson, James B. (Idaho Falls, ID)

    1999-01-01T23:59:59.000Z

    A method of measuring a parameter in a well, under isobaric conditions, including such parameters as hydraulic gradient, pressure, water level, soil moisture content and/or aquifer properties the method as presented comprising providing a casing having first and second opposite ends, and a length between the ends, the casing supporting a transducer having a reference port; placing the casing lengthwise into the well, second end first, with the reference port vented above the water table in the well; and sealing the first end. A system is presented for measuring a parameter in a well, the system comprising a casing having first and second opposite ends, and a length between the ends and being configured to be placed lengthwise into a well second end first; a transducer, the transducer having a reference port, the reference port being vented in the well above the water table, the casing being screened across and above the water table; and a sealing member sealing the first end. In one embodiment, the transducer is a tensiometer transducer and in other described embodiments, another type transducer is used in addition to a tensiometer.

  17. Monitoring well

    DOE Patents [OSTI]

    Hubbell, Joel M. (Idaho Falls, ID); Sisson, James B. (Idaho Falls, ID)

    2002-01-01T23:59:59.000Z

    The present invention relates to a monitoring well which includes an enclosure defining a cavity and a water reservoir enclosed within the cavity and wherein the reservoir has an inlet and an outlet. The monitoring well further includes a porous housing borne by the enclosure and which defines a fluid chamber which is oriented in fluid communication with the outlet of the reservoir, and wherein the porous housing is positioned in an earthen soil location below-grade. A geophysical monitoring device is provided and mounted in sensing relation relative to the fluid chamber of the porous housing; and a coupler is selectively moveable relative to the outlet of reservoir to couple the porous housing and water reservoir in fluid communication. An actuator is coupled in force transmitting relation relative to the coupler to selectively position the coupler in a location to allow fluid communication between the reservoir and the fluid chamber defined by the porous housing.

  18. Energy in density gradient

    E-Print Network [OSTI]

    Vranjes, J

    2015-01-01T23:59:59.000Z

    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 ...

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

    SciTech Connect (OSTI)

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

    2012-06-15T23:59:59.000Z

    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.

  20. Quantum Well Thermoelectrics for Converting Waste Heat to Electricity

    SciTech Connect (OSTI)

    Saeid Ghamaty

    2007-04-01T23:59:59.000Z

    Fabrication development of high efficiency quantum well (QW) thermoelectric continues with the P-type and N-type Si/Si{sub 80}Ge{sub 20} films with encouraging results. These films are fabricated on Si substrates and are being developed for low as well as high temperature operation. Both isothermal and gradient life testing are underway. One couple has achieved over 4000 hours at T{sub H} of 300 C and T{sub C} of 50 C with little or no degradation. Emphasis is now shifting towards couple and module design and fabrication, especially low resistance joining between N and P legs. These modules can be used in future energy conversion systems as well as for air conditioning.

  1. Thermal well-test method

    DOE Patents [OSTI]

    Tsang, Chin-Fu (Albany, CA); Doughty, Christine A. (Berkeley, CA)

    1985-01-01T23:59:59.000Z

    A well-test method involving injection of hot (or cold) water into a groundwater aquifer, or injecting cold water into a geothermal reservoir. By making temperature measurements at various depths in one or more observation wells, certain properties of the aquifer are determined. These properties, not obtainable from conventional well test procedures, include the permeability anisotropy, and layering in the aquifer, and in-situ thermal properties. The temperature measurements at various depths are obtained from thermistors mounted in the observation wells.

  2. A Spectral Conjugate Gradient Method for Unconstrained Optimization

    SciTech Connect (OSTI)

    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

    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.

  3. Block-conjugate-gradient method

    SciTech Connect (OSTI)

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

    1989-09-15T23:59:59.000Z

    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.

  4. High field gradient particle accelerator

    DOE Patents [OSTI]

    Nation, J.A.; Greenwald, S.

    1989-05-30T23:59:59.000Z

    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.

  5. High field gradient particle accelerator

    DOE Patents [OSTI]

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

    1989-01-01T23:59:59.000Z

    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.

  6. Quantitative analysis of compositional changes in InGaAs/InGaAsP quantum wells on GaAs induced by intermixing with a low temperature grown InGaP cap layer

    SciTech Connect (OSTI)

    Hulko, O.; Thompson, D. A.; Czaban, J. A.; Simmons, J. G. [Centre for Emerging Devices and Technologies (CEDT), McMaster University, Hamilton, Ontario L8S 4L8 (Canada)

    2006-08-07T23:59:59.000Z

    Energy-dispersive x-ray spectroscopy was used to analyze quantum well intermixing between an InGaAs quantum well (QW) and InGaAsP barriers grown on GaAs induced by a low temperature, molecular beam epitaxy grown, InGaP cap. This cap layer produces an enhanced blueshift of the photoluminescence (PL) wavelength following postgrowth annealing, and degradation of the PL signal. Cross-sectional transmission electron microscopy reveals modification of the whole structure, with formation of arsenic precipitates, broadening, and subsequent disappearance of the QWs in the capped structure. Uncapped samples are relatively unchanged. Increased phosphorus observed in the QW for capped structures confirms the diffusion of phosphorus from the P-rich cap.

  7. Fully Coupled Well Models for Fluid Injection and Production

    SciTech Connect (OSTI)

    White, Mark D.; Bacon, Diana H.; White, Signe K.; Zhang, Z. F.

    2013-08-05T23:59:59.000Z

    Wells are the primary engineered component of geologic sequestration systems with deep subsurface reservoirs. Wells provide a conduit for injecting greenhouse gases and producing reservoirs fluids, such as brines, natural gas, and crude oil, depending on the target reservoir. Well trajectories, well pressures, and fluid flow rates are parameters over which well engineers and operators have control during the geologic sequestration process. Current drilling practices provided well engineers flexibility in designing well trajectories and controlling screened intervals. Injection pressures and fluids can be used to purposely fracture the reservoir formation or to purposely prevent fracturing. Numerical simulation of geologic sequestration processes involves the solution of multifluid transport equations within heterogeneous geologic media. These equations that mathematically describe the flow of fluid through the reservoir formation are nonlinear in form, requiring linearization techniques to resolve. In actual geologic settings fluid exchange between a well and reservoir is a function of local pressure gradients, fluid saturations, and formation characteristics. In numerical simulators fluid exchange between a well and reservoir can be specified using a spectrum of approaches that vary from totally ignoring the reservoir conditions to fully considering reservoir conditions and well processes. Well models are a numerical simulation approach that account for local conditions and gradients in the exchange of fluids between the well and reservoir. As with the mathematical equations that describe fluid flow in the reservoir, variation in fluid properties with temperature and pressure yield nonlinearities in the mathematical equations that describe fluid flow within the well. To numerically simulate the fluid exchange between a well and reservoir the two systems of nonlinear multifluid flow equations must be resolved. The spectrum of numerical approaches for resolving these equations varies from zero coupling to full coupling. In this paper we describe a fully coupled solution approach for well model that allows for a flexible well trajectory and screened interval within a structured hexahedral computational grid. In this scheme the nonlinear well equations have been fully integrated into the Jacobian matrix for the reservoir conservation equations, minimizing the matrix bandwidth.

  8. CONJUGATE GRADIENT WITH SUBSPACE OPTIMIZATION 1 ...

    E-Print Network [OSTI]

    2011-12-25T23:59:59.000Z

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

  9. Thermal indicator for wells

    DOE Patents [OSTI]

    Gaven, Jr., Joseph V. (Oakton, VA); Bak, Chan S. (Newbury Park, CA)

    1983-01-01T23:59:59.000Z

    Minute durable plate-like thermal indicators are employed for precision measuring static and dynamic temperatures of well drilling fluids. The indicators are small enough and sufficiently durable to be circulated in the well with drilling fluids during the drilling operation. The indicators include a heat resistant indicating layer, a coacting meltable solid component and a retainer body which serves to unitize each indicator and which may carry permanent indicator identifying indicia. The indicators are recovered from the drilling fluid at ground level by known techniques.

  10. Thermal well-test method

    DOE Patents [OSTI]

    Tsang, C.F.; Doughty, C.A.

    1984-02-24T23:59:59.000Z

    A well-test method involving injection of hot (or cold) water into a groundwater aquifer, or injecting cold water into a geothermal reservoir is disclosed. By making temperature measurements at various depths in one or more observation wells, certain properties of the aquifer are determined. These properties, not obtainable from conventional well test procedures, include the permeability anisotropy, and layering in the aquifer, and in-situ thermal properties. The temperature measurements at various depths are obtained from thermistors mounted in the observation wells.

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

    SciTech Connect (OSTI)

    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

    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.

  12. Gas Exchange, Partial Pressure Gradients,

    E-Print Network [OSTI]

    Riba Sagarra, Jaume

    Gas Exchange, Partial Pressure Gradients, and the Oxygen Window Johnny E. Brian, Jr., M 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

  13. Introduction Importance of temperature in streams

    E-Print Network [OSTI]

    Toran, Laura

    , fish reproduction, and aquatic metabolism rates. Nearly every species is temperature sensitive a downstream gradient as the surface water is exposed to solar radiation. Theurer et al. (1984) listed sources-radiation. Inverted temperature gradients (downstream cooling) have been observed where clear cutting exposed head

  14. GEOTHERMAL GRADIENT DATA FOR UTAH Robert E. Blackett

    E-Print Network [OSTI]

    Laughlin, Robert B.

    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

  15. Scaling limits for gradient systems in random environment

    E-Print Network [OSTI]

    P. Goncalves; M. D. Jara

    2007-02-17T23:59:59.000Z

    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.

  16. Temperatures, heat flow, and water chemistry from drill holes in the Raft River geothermal system, Cassia County, Idaho

    SciTech Connect (OSTI)

    Nathenson, M.; Urban, T.C.; Diment, W.H.; Nehring, N.L.

    1980-01-01T23:59:59.000Z

    The Raft River area of Idaho contains a geothermal system of intermediate temperatures (approx. = 150/sup 0/C) at depths of about 1.5 km. Outside of the geothermal area, temperature measurements in three intermediate-depth drill holes (200 to 400 m) and one deep well (1500 m) indicate that the regional conductive heat flow is about 2.5 ..mu..cal/cm/sup 2/ sec or slightly higher and that temperature gradients range from 50/sup 0/ to 60/sup 0/C/km in the sediments, tuffs, and volcanic debris that fill the valley. Within and close to the geothermal system, temperature gradients in intermediate-depth drill holes (100 to 350 m) range from 120/sup 0/ to more than 600/sup 0/C/km, the latter value found close to an artesian hot well that was once a hot spring. Temperatures measured in three deep wells (1 to 2 km) within the geothermal area indicate that two wells are in or near an active upflow zone, whereas one well shows a temperature reversal. Assuming that the upflow is fault controlled, the flow is estimated to be 6 liter/sec per kilometer of fault length. From shut-in pressure data and the estimated flow, the permeability times thickness of the fault is calculated to be 2.4 darcy m. Chemical analyses of water samples from old flowing wells, recently completed intermediate-depth drill holes, and deep wells show a confused pattern. Geothermometer temperatures of shallow samples suggest significant re-equilibration at temperatures below those found in the deep wells. Silica geothermometer temperatures of water samples from the deep wells are in reasonable agreement with measured temperatures, whereas Na-K-Ca temperatures are significantly higher than measured temperatures. The chemical characteristics of the water, as indicated by chloride concentration, are extremely variable in shallow and deep samples. Chloride concentrations of the deep samples range from 580 to 2200 mg/kg.

  17. Gradient Navigation Model for Pedestrian Dynamics

    E-Print Network [OSTI]

    Felix Dietrich; Gerta Köster

    2014-05-14T23:59:59.000Z

    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.

  18. Do Well, Be Well with Diabetes

    E-Print Network [OSTI]

    Do Well, Be Well with Diabetes Do Well, Be Well with Diabetes Lesson Topics ·WhatisDiabetes? ·Nutrition­FirstSteptoDiabetesManagement ·OneDiabetesDiet­NoLongertheSoleOption ·ManagingYourBloodGlucose ·NutritionalLabels ·DiabetesandExercise ·ForGoodMeasureatHomeandEatingOut ·DiabetesMedicines ·Preventingand

  19. 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

  20. An Introduction to the Conjugate Gradient Method

    E-Print Network [OSTI]

    Zhang, Yi

    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

  1. An Introduction to the Conjugate Gradient Method

    E-Print Network [OSTI]

    Shewchuk, Jonathan

    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

  2. Porting the NAS-NPB Conjugate Gradient

    E-Print Network [OSTI]

    Crawford, T. Daniel

    .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

  3. Accurate conjugate gradient methods for shifted systems

    E-Print Network [OSTI]

    Sleijpen, Gerard

    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

  4. A parallel scaled conjugate-gradient

    E-Print Network [OSTI]

    Aykanat, Cevdet

    . 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

  5. 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

  6. Accurate conjugate gradient methods for shifted systems

    E-Print Network [OSTI]

    Sleijpen, Gerard

    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

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    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

  8. The development of a high-throughput gradient array apparatus for the study of porous polymer networks.

    SciTech Connect (OSTI)

    Majumdar, Partha (North Dakota State University, Fargo, ND); Lee, Elizabeth (North Dakota State University, Fargo, ND); Chisholm, Bret J. (North Dakota State University, Fargo, ND); Dirk, Shawn M.; Weisz, Michael (North Dakota State University, Fargo, ND); Bahr, James (North Dakota State University, Fargo, ND); Schiele, Kris (North Dakota State University, Fargo, ND)

    2010-01-01T23:59:59.000Z

    A gradient array apparatus was constructed for the study of porous polymers produced using the process of chemically-induced phase separation (CIPS). The apparatus consisted of a 60 element, two-dimensional array in which a temperature gradient was placed in the y-direction and composition was varied in the x-direction. The apparatus allowed for changes in opacity of blends to be monitored as a function of temperature and cure time by taking images of the array with time. The apparatus was validated by dispense a single blend composition into all 60 wells of the array and curing them for 24 hours and doing the experiment in triplicate. Variations in micron scale phase separation were readily observed as a function of both curing time and temperature and there was very good well-to-well consistency as well as trial-to-trial consistency. Poragen of samples varying with respect to cure temperature was removed and SEM images were obtained. The results obtained showed that cure temperature had a dramatic affect on sample morphology, and combining data obtained from visual observations made during the curing process with SEM data can enable a much better understanding of the CIPS process and provide predictive capability through the relatively facile generation of composition-process-morphology relationships. Data quality could be greatly enhanced by making further improvements in the apparatus. The primary improvements contemplated include the use of a more uniform light source, an optical table, and a CCD camera with data analysis software. These improvements would enable quantification of the amount of scattered light generated from individual elements as a function of cure time. In addition to the gradient array development, porous composites were produced by incorporating metal particles into a blend of poragen, epoxy resin, and crosslinker. The variables involved in the experiment were metal particle composition, primary metal particle size, metal concentration, and poragen composition. A total of 16 different porous composites were produced and characterized using SEM. In general, the results showed that pore morphology and the distribution of metal particles was dependent on multiple factors. For example, the use of silver nanoparticles did not significantly affect pore morphology for composites derived from decanol as the poragen, but exceptionally large pores were obtained with the use of decane as the poragen. With regard to the effect of metal particle size, silver nanoparticles were essentially exclusively dispered in the polymer matrix while silver microparticles were found in pores. For nickel particles, both nanoparticles and microparticles were largely dispersed in the polymer matrix and not in the pores.

  9. Shape reconstruction from gradient data

    SciTech Connect (OSTI)

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

    2008-04-20T23:59:59.000Z

    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.

  10. Gradient limits and SCRF performance.

    SciTech Connect (OSTI)

    Norem, J.; Pellin, M.

    2007-01-01T23:59:59.000Z

    Superconducting rf gradients are limited by a number of mechanisms, among them are field emission, multipactor, Lorentz detuning, global and local heating, quench fields, Q-Slope, assembly defects, and overall power use. We describe how each of these mechanisms interacts with the cavity fields and show how significant improvements may be possible assuming improvements in control over the cavity surface. New techniques such as Atomic Layer Deposition (ALD), the use of layered composites, Gas Cluster Ion Beam (GCIB) smoothing and Dry Ice Cleaning (DIC) have been proposed as ways to control the surface.

  11. Gradient Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdfGetec AG Contracting JumpGove County, Kansas: EnergyGradient Resources Jump to:

  12. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489InformationFrenchtown,Jump to:Locations2002)

  13. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 NoEurope BV JumpFederal HighwayFernley, Nevada:Controls Jump

  14. Compensated geothermal gradient: new map of old data

    SciTech Connect (OSTI)

    Ibrahim, M.W.

    1986-05-01T23:59:59.000Z

    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.

  15. Risk Distance: The Loss of Strength Gradient and Colombia's Geography of Impunity

    E-Print Network [OSTI]

    Demarest, Geoffrey

    2013-12-31T23:59:59.000Z

    material under- performance and organized violence. The opposite certainly appears true; close proximity of a 4 group of violent armed men can quickly diminish the material well-being of a geographically isolated community. Trying to paint, adjust..., is known as the Loss of Strength Gradient, a term proposed 7 by economist Kenneth Boulding in 1962. (Boulding 1962). Although Professor Boulding used the term in relation to global strategy, the loss of strength gradient applies equally well...

  16. Optimization Online - Using Simplex Gradients of Nonsmooth ...

    E-Print Network [OSTI]

    A. L. Custódio

    2006-10-27T23:59:59.000Z

    Oct 27, 2006 ... Using Simplex Gradients of Nonsmooth Functions in Direct Search Methods. A. L. Custódio (alcustodio ***at*** fct.unl.pt) J. E. Dennis (dennis ...

  17. Optimization Online - A Nonlinear Conjugate Gradient Algorithm ...

    E-Print Network [OSTI]

    Yu-Hong Dai

    2011-06-28T23:59:59.000Z

    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 ...

  18. A GLOBALLY CONVERGENT MODIFIED CONJUGATE-GRADIENT ...

    E-Print Network [OSTI]

    2009-10-01T23:59:59.000Z

    gradient algorithms which implements this strategy in a robust and efficient way. ... Both begin with a second-order Taylor expansion modeling changes in f(xk) ...

  19. Optimization of synchronization in gradient clustered networks

    E-Print Network [OSTI]

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

    2007-11-23T23:59:59.000Z

    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.

  20. High characteristics temperature of strain-compensated 1.3 {micro}m InAsP/InGaP/InP multi-quantum well lasers grown by all solid source molecular beam epitaxy

    SciTech Connect (OSTI)

    Savolainen, P.; Toivonen, M.; Salokatve, A. [Tampere Univ. of Technology (Finland). Dept. of Physics; Asonen, H. [Tutcore Ltd., Tampere (Finland); Murison, R. [EG and G Optoelectronics Canada, Vaudreuil, Quebec (Canada)

    1996-12-31T23:59:59.000Z

    The present lasers have very good characteristic temperature values for the threshold current. In order to maintain such performance in cw mode, one should either use narrow waveguide (buried) type of laser structure or reduce the number of QWs. If the number of QW`s is reduced, total gain decreases and this should be compensated by increasing the optical confinement factor. In this paper the authors have demonstrated the suitability of InAsP/InGaP strain-compensated system for high temperature lasers emitting 1.3 {micro}m and the potential of all solid source molecular beam epitaxy for growth of optoelectronic devices.

  1. BUFFERED WELL FIELD OUTLINES

    U.S. Energy Information Administration (EIA) Indexed Site

    OIL & GAS FIELD OUTLINES FROM BUFFERED WELLS The VBA Code below builds oil & gas field boundary outlines (polygons) from buffered wells (points). Input well points layer must be a...

  2. Geothermal Well and Heat Flow Data for the United States (Southern Methodist University (SMU) Geothermal Laboratory)

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

    Blackwell, D.D. and others

    Southern Methodist University makes two databases and several detailed maps available. The Regional Heat Flow Database for the United States contains information on primarily regional or background wells that determine the heat flow for the United States; temperature gradients and conductivity are used to generate heat flow measurements. Information on geology of the location, porosity, thermal conductivity, water table depth, etc. are also included when known. There are usually three data files for each state or region. The first files were generated in 1989 for the data base creating the Decade of North America Geology (DNAG) Geothermal Map. The second set is from 1996 when the data base was officially updated for the Department of Energy. The third set is from 1999 when the Western U.S. High Temperature Geothermal data base was completed. As new data is received, the files continue to be updated. The second major resource is the Western Geothermal Areas Database, a database of over 5000 wells in primarily high temperature geothermal areas from the Rockies to the Pacific Ocean. The majority of the data are from company documents, well logs, and publications with drilling dates ranging from 1960 to 2000. Many of the wells were not previously accessible to the public. Users will need to register, but will then have free, open access to the databases. The contents of each database can be viewed and downloaded as Excel spreadsheets. See also the heat flow maps at http://www.smu.edu/geothermal/heatflow/heatflow.htm

  3. High Gradient Two-Beam Electron Accelerator

    SciTech Connect (OSTI)

    Jiang, Y. [Beam Physics Laboratory, Yale University, 272 Whitney Ave., New Haven, CT 06511 (United States); Kazakov, S. Yu. [Omega-P, Inc., 258 Bradley St., New Haven, CT 06510 (United States); Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Kuzikov, S. V. [Omega-P, Inc., 258 Bradley St., New Haven, CT 06510 (United States); Institute of Applied Physics, Nizhny Novgorod, 603600 (Russian Federation); Hirshfield, J. L. [Beam Physics Laboratory, Yale University, 272 Whitney Ave., New Haven, CT 06511 (United States); Omega-P, Inc., 258 Bradley St., New Haven, CT 06510 (United States)

    2010-11-04T23:59:59.000Z

    A high-gradient two-beam electron accelerator structure using detuned cavities is described. A self-consistent theory based on a circuit model is presented to calculate idealized acceleration gradient, transformer ratio, and efficiency for energy transfer from the drive beam to the accelerated beam. Experimental efforts are being carried out to demonstrate this acceleration concept.

  4. Regulations of Wells (Florida)

    Broader source: Energy.gov [DOE]

    The Department of Environmental Protection regulates the construction, repair, and abandonment of wells, as well as the persons and businesses undertaking such practices. Governing boards of water...

  5. Groundwater and Wells (Nebraska)

    Broader source: Energy.gov [DOE]

    This section describes regulations relating to groundwater protection, water wells, and water withdrawals, and requires the registration of all water wells in the state.

  6. Molecular Dynamic Approach of Enhanced Self-Propelled Nano-Droplet Motion on Wettability Gradient Surfaces

    E-Print Network [OSTI]

    Chakraborty, Monojit; Bhusan, Richa; DasGupta, Sunando

    2015-01-01T23:59:59.000Z

    Droplet motion over a surface with wettability gradient has been simulated using molecular dynamics (MD) simulation to highlight the underlying physics. GROMACS and Visual Molecular Dynamics (VMD) were used for simulation and intermittent visualization of the droplet configuration respectively. The simulations mimic experiments in a comprehensive manner wherein micro-sized droplets are propelled by surface wettability gradient against a number of retarding forces. The liquid-wall Lennard-Jones interaction parameter and the substrate temperature were varied to explore their effects on the three-phase contact line friction coefficient. The contact line friction was observed to be a strong function of temperature at atomistic scales, confirming the experimentally observed inverse functionality between the coefficient of contact line friction and increase in temperatures. These MD simulation results were successfully compared with the results from a model for self-propelled droplet motion on gradient surfaces.

  7. Approximate error conjugation gradient minimization methods

    DOE Patents [OSTI]

    Kallman, Jeffrey S

    2013-05-21T23:59:59.000Z

    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.

  8. Death Valley Lower Carbonate Aquifer Monitoring Program Wells Down Gradient of the Proposed Yucca Mountain Nuclear Waste Repository, U. S. Department of Energy Grant DE-RW0000233 2010 Project Report, prepared by The Hydrodynamics Group, LLC for Inyo County Yucca Mountain Repository Assessment Office

    SciTech Connect (OSTI)

    King, Michael J; Bredehoeft, John D., Dr.

    2010-09-03T23:59:59.000Z

    Inyo County completed the first year of the U.S. Department of Energy Grant Agreement No. DE-RW0000233. This report presents the results of research conducted within this Grant agreement in the context of Inyo County's Yucca Mountain oversight program goals and objectives. The Hydrodynamics Group, LLC prepared this report for Inyo County Yucca Mountain Repository Assessment Office. The overall goal of Inyo County's Yucca Mountain research program is the evaluation of far-field issues related to potential transport, by ground water, of radionuclide into Inyo County, including Death Valley, and the evaluation of a connection between the Lower Carbonate Aquifer (LCA) and the biosphere. Data collected within the Grant is included in interpretive illustrations and discussions of the results of our analysis. The centeral elements of this Grant prgoram was the drilling of exploratory wells, geophysical surveys, geological mapping of the Southern Funeral Mountain Range. The cullimination of this research was 1) a numerical ground water model of the Southern Funeral Mountain Range demonstrating the potential of a hydraulic connection between the LCA and the major springs in the Furnace Creek area of Death Valley, and 2) a numerical ground water model of the Amargosa Valley to evaluate the potential for radionuclide transport from Yucca Mountain to Inyo County, California. The report provides a description of research and activities performed by The Hydrodynamics Group, LLC on behalf of Inyo County, and copies of key work products in attachments to this report.

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

    SciTech Connect (OSTI)

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

    2009-09-01T23:59:59.000Z

    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.

  10. Unique aspects of drilling and completing hot-dry-rock geothermal wells

    SciTech Connect (OSTI)

    Carden, R.S.; Nicholson, R.W.; Pettitt, R.A.; Rowley, J.C.

    1983-01-01T23:59:59.000Z

    Drilling operations at the Fenton Hill Hot Dry Rock (HDR) Geothermal Test Site have led to numerous developments needed to solve the problems caused by a very harsh downhole environment. A pair of deep wells were drilled to approximately 15,000 ft (4.6 km); formation temperatures were in excess of 600/sup 0/F (300/sup 0/C). The wells were directionally drilled, inclined at 35/sup 0/, one above the other, in a direction orthogonal to the least principal stress field. The well site is near the flank of a young silicic composite volcano in the Jemez Mountains of northern New Mexico. The completion of this pair of wells is unique in reservoir development. The lower well was planned as a cold water injector which will be cooled by the introduced water from the static geothermal gradient to about 80/sup 0/F (25/sup 0/C). The upper well will be heated during production to over 500/sup 0/F (250/sup 0/C). The well pair is designed to perform as a closed loop heat-extraction system connected by hydraulic fractures with a vertical spacing of 1200 ft between the wells. These conditions strongly constrain the drilling technique, casing design, cement formulation, and cementing operations.

  11. Gradient Plasticity Model and its Implementation into MARMOT

    SciTech Connect (OSTI)

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

    2013-08-01T23:59:59.000Z

    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.

  12. Measurement of thermodynamics using gradient flow

    E-Print Network [OSTI]

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

    2014-12-15T23:59:59.000Z

    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.

  13. Time changes in gradient and observed winds 

    E-Print Network [OSTI]

    Carlson, Ronald Dale

    1972-01-01T23:59:59.000Z

    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...

  14. Underground Wells (Oklahoma)

    Broader source: Energy.gov [DOE]

    Class I, III, IV and V injection wells require a permit issued by the Executive Director of the Department of Environmental Quality; Class V injection wells utilized in the remediation of...

  15. Plugging Abandoned Water Wells

    E-Print Network [OSTI]

    Lesikar, Bruce J.

    2002-02-28T23:59:59.000Z

    This brochure explains the threat of abandoned water wells to groundwater resources and the responsibility and liability of Texas property owners. It offers information to landowners on ways to plug such wells....

  16. Horizontal well circulation tool

    SciTech Connect (OSTI)

    Not Available

    1990-11-06T23:59:59.000Z

    This patent describes an apparatus for securement onto one end of a continuous length of remedial tubing introducible into a subterranean well and concentrically insertable through production tubing previously positioned within the well. The well having a deviated configuration including an entry portion communicating with a curved portion extending downwardly in the well from the entry portion, and a generally linear end portion traversable with a production formation.

  17. 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

  18. Developing new high energy gradient concentration cathode material...

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

    new high energy gradient concentration cathode material Developing new high energy gradient concentration cathode material 2009 DOE Hydrogen Program and Vehicle Technologies...

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

    E-Print Network [OSTI]

    Wenwen Zhou

    2009-09-23T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    2011-09-09T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Roberta De Asmundis

    2014-06-14T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    2011-05-09T23:59:59.000Z

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

  3. 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...

  4. Thermal Gradient Holes At Salt Wells Area (Bureau of Land Management, 2009)

    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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-f <MaintainedInformationThe year openEnergy2003)Energy| Open Energy

  5. Gas flow to a barometric pumping well in a multilayer unsaturated Kehua You,1

    E-Print Network [OSTI]

    Zhan, Hongbin

    Gas flow to a barometric pumping well in a multilayer unsaturated zone Kehua You,1 Hongbin Zhan,1. [1] When an open well is installed in an unsaturated zone, gas can flow between the subsurface and the well depending on the gas pressure gradient near the well. This well is called a barometric pumping

  6. Plugging Abandoned Water Wells 

    E-Print Network [OSTI]

    Lesikar, Bruce J.

    2002-02-28T23:59:59.000Z

    is one of our state?s most precious resources. Groundwater from aquifers (underground layers of porous rock or sand containing water, into which wells can be drilled) supplies over half of the water used in the state. Protecting the quality of this vital... of Licensing and Regulation (TDLR). Abandoned wells are a threat to our water supply An abandoned well is a direct channel from the surface to the aquifer below. Contaminants that enter a well are introduced directly into the aquifer with no opportunity...

  7. Solar rotation rate and its gradients during cycle 23

    E-Print Network [OSTI]

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

    2008-05-22T23:59:59.000Z

    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.

  8. CONTINUOUS EDGE GRADIENT-BASED TEMPLATE MATCHING FOR ARTICULATED OBJECTS

    E-Print Network [OSTI]

    Daniel Mohr; Gabriel Zachmann

    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

  9. Multiscale Analysis of the Gradient of Linear Polarisation

    E-Print Network [OSTI]

    Robitaille, J -F

    2015-01-01T23:59:59.000Z

    We propose a new multiscale method to calculate the amplitude of the gradient of the linear polarisation vector using a wavelet-based formalism. We demonstrate this method using a field of the Canadian Galactic Plane Survey (CGPS) and show that the filamentary structure typically seen in gradients of linear polarisation maps depends strongly on the instrumental resolution. Our analysis reveals that different networks of filaments are present on different angular scales. The wavelet formalism allows us to calculate the power spectrum of the fluctuations seen in gradients of linear polarisation maps and to determine the scaling behaviour of this quantity. The power spectrum is found to follow a power law with gamma ~ 2.1. We identify a small drop in power between scales of 80 well to the overlap in the u-v plane between the Effelsberg 100-m telescope and the DRAO 26-m telescope data. We suggest that this drop is due to undersampling present in the 26-m telescope data. I...

  10. C ISOTOPE GRADIENT DERIVED FROM MILLIMETER TRANSITIONS OF CN: THE CASE FOR GALACTIC CHEMICAL EVOLUTION

    E-Print Network [OSTI]

    Ziurys, Lucy M.

    THE 12 C/13 C ISOTOPE GRADIENT DERIVED FROM MILLIMETER TRANSITIONS OF CN: THE CASE FOR GALACTIC kinetic temperature, suggests that chemical fractionation and isotope-selective photodissociation both do be a result of 13 C enrichment since the formation of the solar system, as predicted by recent models. Subject

  11. Spin Gradient Demagnetization Cooling of Ultracold Atoms Patrick Medley,* David M. Weld,

    E-Print Network [OSTI]

    effective spin temperatures of Ć50 pK. The spin system can also be used to cool other degrees of freedomSpin Gradient Demagnetization Cooling of Ultracold Atoms Patrick Medley,* David M. Weld, Hirokazu Miyake, David E. Pritchard, and Wolfgang Ketterle MIT-Harvard Center for Ultracold Atoms, Research

  12. ADVANCED CEMENTS FOR GEOTHERMAL WELLS

    SciTech Connect (OSTI)

    SUGAMA,T.

    2007-01-01T23:59:59.000Z

    Using the conventional well cements consisting of the calcium silicate hydrates (CaO-SiO{sub 2}-H{sub 2}O system) and calcium aluminum silicate hydrates (CaO-Al{sub 2}O{sub 3}-SiO{sub 2}-H{sub 2}O system) for the integrity of geothermal wells, the serious concern confronting the cementing industries was their poor performance in mechanically supporting the metallic well casing pipes and in mitigating the pipe's corrosion in very harsh geothermal reservoirs. These difficulties are particularly acute in two geological regions: One is the deep hot downhole area ({approx} 1700 m depth at temperatures of {approx} 320 C) that contains hyper saline water with high concentrations of CO{sub 2} (> 40,000 ppm) in conjunction with {approx} 100 ppm H{sub 2}S at a mild acid of pH {approx} 5.0; the other is the upper well region between the well's surface and {approx} 1000 m depth at temperatures up to 200 C. The specific environment of the latter region is characterized by highly concentrated H{sub 2}SO{sub 4} (pH < 1.5) brine containing at least 5000 ppm CO{sub 2}. When these conventional cements are emplaced in these harsh environments, their major shortcoming is their susceptibility to reactions with hot CO{sub 2} and H{sub 2}SO4, thereby causing their deterioration brought about by CO{sub 2}-catalyzed carbonation and acid-initiated erosion. Such degradation not only reduced rapidly the strength of cements, lowering the mechanical support of casing pipes, but also increased the extent of permeability of the brine through the cement layer, promoting the rate of the pipe's corrosion. Severely carbonated and acid eroded cements often impaired the integrity of a well in less than one year; in the worst cases, casings have collapsed within three months, leading to the need for costly and time-consuming repairs or redrilling operations. These were the reasons why the geothermal well drilling and cementing industries were concerned about using conventional well cements, and further their deterioration was a major impediment in expediting the development of geothermal energy resources.

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

    SciTech Connect (OSTI)

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

    1995-11-09T23:59:59.000Z

    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.

  14. The gradient flow running coupling with twisted boundary conditions

    E-Print Network [OSTI]

    A. Ramos

    2014-09-04T23:59:59.000Z

    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.

  15. TOWARDS STOCHASTIC CONJUGATE GRADIENT METHODS Nicol N. Schraudolph Thore Graepel

    E-Print Network [OSTI]

    Schraudolph, Nicol N.

    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

  16. Relationship between gradient and EM steps in latent variable models.

    E-Print Network [OSTI]

    Roweis, Sam

    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

  17. 11 SOME PROPERTIES OF A NEW CONJUGATE GRADIENT METHOD

    E-Print Network [OSTI]

    Yuan, Ya-xiang

    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

  18. Relationship between gradient and EM steps in latent variable models.

    E-Print Network [OSTI]

    Roweis, Sam

    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

  19. Drilling and thermal gradient measurements at US Marine Corps Air Ground Combat Center, Twentynine Palms, California. Final report, October 1, 1983-March 31, 1984

    SciTech Connect (OSTI)

    Trexler, D.T.; Flynn, T.; Ghusn, G. Jr.

    1984-01-01T23:59:59.000Z

    Seven temperature gradient holes were drilled at the Marine Corps Air Ground Combat Center, Twentynine Palms, California, as part of a cooperative research and development program, jointly funded by the Navy and Department of Energy. The purpose of this program was to assess geothermal resources at selected Department of Defense installations. Drill site selection was based on geophysical anomalies delineated by combined gravity, ground magnetic and aeromagnetic surveys. Temperature gradients ranged from 1.3/sup 0/C/100 m (1/sup 0/F/100 ft.) in hole No. 1 to 15.3/sup 0/C/100 m (8.3/sup 0/F/100 ft.) in temperature gradient hole No. 6. Large, positive geothermal gradients in temperature gradient holes 5 and 6, combined with respective bottom hole temperatures of 51.6/sup 0/C (125/sup 0/F) and 67/sup 0/C (153/sup 0/F), indicate that an extensive, moderate-temperature geothermal resource is located on the MCAGCC. The geothermal reservoir appears to be situated in old, unconsolidated alluvial material and is structurally bounded on the east by the Mesquite Lake fault and on the west by the Surprise Spring fault. If measured temperature gradients continue to increase at the observed rate, temperatures in excess of 80/sup 0/C (178/sup 0/F) can be expected at a depth of 2000 feet.

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

    E-Print Network [OSTI]

    Helgaker, Trygve

    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

  1. Conjugate gradient algorithms using multiple recursions

    SciTech Connect (OSTI)

    Barth, T.; Manteuffel, T.

    1996-12-31T23:59:59.000Z

    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.

  2. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand JumpConceptual Model, click here.Telluric Survey asWest,CEI Jump to:Cerion EnergyEnergy

  3. High Temperature, High Pressure Devices for Zonal Isolation in...

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

    High Temperature, High Pressure Devices for Zonal Isolation in Geothermal Wells High Temperature, High Pressure Devices for Zonal Isolation in Geothermal Wells High Temperature,...

  4. Subsurface well apparatus

    SciTech Connect (OSTI)

    Rubbo, R.B.; Bangert, D.S.

    1993-07-13T23:59:59.000Z

    An apparatus is described for completing a subterranean well, comprising: a tubular conduit portion made up within a tubular conduit string of the type extending from a point near the surface of the earth to a remote point downwardly within said well and which is in contact with a fluid source within said well, said tubular conduit portion forming an imperforate wall and defining a central bore radially inward and further defining an exterior surface; an activating fluid body in communication with, and disposed at least in-part within, said central bore of tubular conduit portion; signal generating means including at least one sensor member coupled to said exterior surface of said tubular conduit portion for detecting circumferential stress in said imperforate wall defined by said tubular conduit portion and for producing an output signal corresponding thereto; a well bore tool disposed exteriorly of said tubular conduit portion, and including an actuating member for performing at least one desired completion function; and control means responsive to a predetermined output signal from said signal generating means for selectively activating said well bore tool and causing said actuating member to perform at least one desired completion function.

  5. Time changes in gradient and observed winds

    E-Print Network [OSTI]

    Carlson, Ronald Dale

    1972-01-01T23:59:59.000Z

    - cal purposes, represents the changes in the components of the gradient wind speed, as calculated from Eqs. (9) and (10). Equations (9) and (10) were solved by the use of finite dif- ference methods. Due to the long incremental time steps, 3 to 12... hours, the changes in the components of the gradient wind speed obtained numerically from Eqs. (9) and (10) may differ slightly from the changes observed due to the numerical techniques employed. How- ever, the patterns obtained by the two methods...

  6. High-pressure liquid chromatographic gradient mixer

    DOE Patents [OSTI]

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

    1982-09-08T23:59:59.000Z

    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.

  7. High pressure liquid chromatographic gradient mixer

    DOE Patents [OSTI]

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

    1985-01-01T23:59:59.000Z

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

  8. Spacer for deep wells

    SciTech Connect (OSTI)

    Klein, G. D.

    1984-10-23T23:59:59.000Z

    A spacer for use in a deep well that is to have a submersible pump situated downhole and with a string of tubing attached to the pump for delivering the pumped fluid. The pump is electrically driven, and power is supplied via an armored cable which parallels the string of tubing. Spacers are clamped to the cable and have the tubing running through an eccentrically located passage in each spacer. The outside dimensions of a spacer fit freely inside any casing in the well.

  9. Mountain Home Well - Photos

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

    Shervais, John

    The Snake River Plain (SRP), Idaho, hosts potential geothermal resources due to elevated groundwater temperatures associated with the thermal anomaly Yellowstone-Snake River hotspot. Project HOTSPOT has coordinated international institutions and organizations to understand subsurface stratigraphy and assess geothermal potential. Over 5.9km of core were drilled from three boreholes within the SRP in an attempt to acquire continuous core documenting the volcanic and sedimentary record of the hotspot: (1) Kimama, (2) Kimberly, and (3) Mountain Home. The Mountain Home drill hole is located along the western plain and documents older basalts overlain by sediment. Data submitted by project collaborator Doug Schmitt, University of Alberta

  10. STIMULATION TECHNOLOGIES FOR DEEP WELL COMPLETIONS

    SciTech Connect (OSTI)

    Stephen Wolhart

    2003-06-01T23:59:59.000Z

    The Department of Energy (DOE) is sponsoring a Deep Trek Program targeted at improving the economics of drilling and completing deep gas wells. Under the DOE program, Pinnacle Technologies is conducting a project to evaluate the stimulation of deep wells. The objective of the project is to assess U.S. deep well drilling & stimulation activity, review rock mechanics & fracture growth in deep, high pressure/temperature wells and evaluate stimulation technology in several key deep plays. Phase 1 was recently completed and consisted of assessing deep gas well drilling activity (1995-2007) and an industry survey on deep gas well stimulation practices by region. Of the 29,000 oil, gas and dry holes drilled in 2002, about 300 were drilled in the deep well; 25% were dry, 50% were high temperature/high pressure completions and 25% were simply deep completions. South Texas has about 30% of these wells, Oklahoma 20%, Gulf of Mexico Shelf 15% and the Gulf Coast about 15%. The Rockies represent only 2% of deep drilling. Of the 60 operators who drill deep and HTHP wells, the top 20 drill almost 80% of the wells. Six operators drill half the U.S. deep wells. Deep drilling peaked at 425 wells in 1998 and fell to 250 in 1999. Drilling is expected to rise through 2004 after which drilling should cycle down as overall drilling declines.

  11. Efficient Gradient Computation for Dynamical B. Sengupta

    E-Print Network [OSTI]

    Penny, Will

    descriptive length, variational free energy, etc. Generally, optimisation rests on evaluating the localEfficient Gradient Computation for Dynamical Models B. Sengupta , K.J. Friston and W.D. Penny of thousands of neurons using fMRI. Data assimilation involves inverting a generative model that can not only

  12. Application of Gradient Expansion to Inflationary Universe

    E-Print Network [OSTI]

    Yasusada Nambu; Atsushi Taruya

    1994-11-03T23:59:59.000Z

    Using the long wave perturbation scheme(gradient expansion), the effect of inhomogeneity on the inflationary phase is investigated. We solved the perturbation equation of which source term comes from inhomogeneity of a scalar field and a seed metric. The result indicates that sub-horizon scale inhomogeneity strongly affects the onset of inflation.

  13. Gradient Clock Synchronization in Wireless Sensor Networks

    E-Print Network [OSTI]

    Gradient Clock Synchronization in Wireless Sensor Networks Philipp Sommer Computer Engineering- olution. Without doubt, time is a first-class citizen in wireless sensor networks. Without accurate time if the nodes in the wireless sensor network manage to have an adequate agreement of time. Indeed

  14. Universal Microfluidic Gradient Generator Daniel Irimia1

    E-Print Network [OSTI]

    Geba, Dan-Andrei

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

  15. Fourier Accelerated Conjugate Gradient Lattice Gauge Fixing

    E-Print Network [OSTI]

    R. J. Hudspith

    2014-05-22T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

    Hull, J.R.

    1982-09-29T23:59:59.000Z

    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.

  17. Well valve control system

    SciTech Connect (OSTI)

    Schwendemann, K.L.; McCracken, O.W.; Mondon, C.G.; Wortham, L.C.

    1987-01-13T23:59:59.000Z

    A system is described for controlling well testing through an upper and lower test string with a subsea test tree connected therebetween and latch means to release the upper test string from the subsea test tree comprising: a. first and second selectively programmable microprocessor means; b. means for storing system operating limits in each microprocessor means; c. means for changing the operating limits in response to changes in well conditions; d. means for communicating operating fluid pressure to the subsurface test tree and the latch means; e. solenoid pilot valves controlling the flow of the operating fluid pressure to the subsea test tree and the latch means; f. the first microprocessor means located at a central control console; g. the second microprocessor means located near the solenoid valves; h. means for transmitting signals between the first and second microprocessor means and validating the accuracy of the signals; and i. electronic circuits to control operation of the solenoid valves in response to validated signals.

  18. Shock Chlorination of Wells

    E-Print Network [OSTI]

    McFarland, Mark L.; Dozier, Monty

    2003-06-11T23:59:59.000Z

    method) will be necessary to ensure the safety of the water supply. Shock chlorination introduces very high levels of chlorine into a water system. During the disinfec- tion process, water from the system is not suitable for consumption and neither people... system or other continuous disinfection sys- tem. For more information about wellhead protection, see the Tex-A-Syst rural water well assessment pub- lications (B-6023 through B-6032) available from Texas Cooperative Extension. 3 This publication...

  19. Decontaminating Flooded Wells

    E-Print Network [OSTI]

    Boellstorff, Diana; Dozier, Monty; Provin, Tony; Dictson, Nikkoal; McFarland, Mark L.

    2005-09-30T23:59:59.000Z

    ER-011 6-06 Mark L. McFarland, Associate Professor and Extension Water Resources Specialist; Diane E. Boellstorff, Program Specialist Water Quality; Tony L. Provin, Associate Professor and Extension Soil Chemist; Monty C. Dozier, Assistant... and local hospitals may also test water samples for bacteria. The cost of the test ranges from $8 to $30, depending on the lab. Well disinfection does not eliminate hydrocarbons (fuels, oils), pesticides, heavy metals or other types of nonbiological...

  20. Lithologic Descriptions and Temperature Profiles of Five Wells in the

    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 onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal Pwer Plant Jump to:Landowners and WindLightingLinthicum, Maryland:source HistoryLite Trough

  1. Buckhorn Mineral Wells Pool & Spa Low Temperature Geothermal Facility |

    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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:EzfeedflagBiomassSustainable and InnovativeBrookmont,Florida:BryantBuchanan,

  2. Buckhorn Mineral Wells Space Heating Low Temperature Geothermal Facility |

    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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:EzfeedflagBiomassSustainable and InnovativeBrookmont,Florida:BryantBuchanan,Open Energy

  3. Estimation of static formation temperatures in geothermal wells | 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand JumpConceptual Model,DOEHazelPennsylvania: Energy Resources JumpVermont: EnergySystems

  4. Jackson Well Springs Space Heating Low Temperature Geothermal Facility |

    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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdfGetecGtelInterias Solar EnergyEnergyKansas: EnergySouthEnergyParish,

  5. Pagosa Springs Private Wells Space Heating Low Temperature 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 onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal Pwer PlantMunhall,Missouri:EnergyOssian, New York:Ozark,Pacific GasPage" ShowingFacility

  6. Old Wright Well Greenhouse Low Temperature Geothermal Facility | 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 onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal Pwer PlantMunhall,Missouri: EnergyExcellenceOffice of StateOklahomaField,

  7. Countryman Well Greenhouse Low Temperature Geothermal Facility | 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand JumpConceptual Model, clickInformationNew|Core AnalysisCouncil, Idaho: Energy ResourcesWalk,Energy

  8. Temperature Data From Wells in Long Valley Caldera, California | 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 onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro Industries PvtStratosolar Jump to:HoldingsTechint Spa JumpTVCEt Al.,(Biasi,Tempe,Energy

  9. High Temperature Quantum Well Materials | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(Fact Sheet), GeothermalGridHYDROGEND D e e p p a a r r t t m m e e n n t t2

  10. Low temperature geothermal resource evaluation of the Moses Lake-Ritzville-Connell area, Washington

    SciTech Connect (OSTI)

    Widness, S.

    1983-11-01T23:59:59.000Z

    The study area is located in portions of Adams, Grant, Lincoln, and Franklin counties of eastern Washington. The area is representative of a complex stratigraphic and geohydrologic system within the basalt flows of the Columbia River Basalt Group. Fluid temperature data were collected by three different agencies. The Geological Engineering Section (WSU) at Washington State University, runs a continuous fluid temperature (FT) log as part of a complete suite of geophysical logs. The US Geological Survey (USGS) runs a continuous fluid FT log in conjunction with caliper and natural-gamma logs. Southern Methodist University (SMU) and the Washington State Department of Natural Resources, Division of Geology and Earth Resources (DNR), have cooperated in gathering FT data. The DNR-SMU data were collected by taking temperature measurements at 5 m intervals. Bottom-hole temperatures (BHT) and bottom-hole depths (BHD) of selected wells in the study area are given. A technique developed by Biggane (1982) was used to determine the geothermal gradients within the area. A least squares linear regression analysis of the relationship between the BHT and BHD was used to determine the geothermal gradient of a given well data group (WDG).

  11. A Resource Assessment Of Geothermal Energy Resources For Converting Deep Gas Wells In Carbonate Strata Into Geothermal Extraction Wells: A Permian Basin Evaluation

    SciTech Connect (OSTI)

    Erdlac, Richard J., Jr.

    2006-10-12T23:59:59.000Z

    Previously conducted preliminary investigations within the deep Delaware and Val Verde sub-basins of the Permian Basin complex documented bottom hole temperatures from oil and gas wells that reach the 120-180C temperature range, and occasionally beyond. With large abundances of subsurface brine water, and known porosity and permeability, the deep carbonate strata of the region possess a good potential for future geothermal power development. This work was designed as a 3-year project to investigate a new, undeveloped geographic region for establishing geothermal energy production focused on electric power generation. Identifying optimum geologic and geographic sites for converting depleted deep gas wells and fields within a carbonate environment into geothermal energy extraction wells was part of the project goals. The importance of this work was to affect the three factors limiting the expansion of geothermal development: distribution, field size and accompanying resource availability, and cost. Historically, power production from geothermal energy has been relegated to shallow heat plumes near active volcanic or geyser activity, or in areas where volcanic rocks still retain heat from their formation. Thus geothermal development is spatially variable and site specific. Additionally, existing geothermal fields are only a few 10’s of square km in size, controlled by the extent of the heat plume and the availability of water for heat movement. This plume radiates heat both vertically as well as laterally into the enclosing country rock. Heat withdrawal at too rapid a rate eventually results in a decrease in electrical power generation as the thermal energy is “mined”. The depletion rate of subsurface heat directly controls the lifetime of geothermal energy production. Finally, the cost of developing deep (greater than 4 km) reservoirs of geothermal energy is perceived as being too costly to justify corporate investment. Thus further development opportunities for geothermal resources have been hindered. To increase the effective regional implementation of geothermal resources as an energy source for power production requires meeting several objectives. These include: 1) Expand (oil and gas as well as geothermal) industry awareness of an untapped source of geothermal energy within deep permeable strata of sedimentary basins; 2) Identify and target specific geographic areas within sedimentary basins where deeper heat sources can be developed; 3) Increase future geothermal field size from 10 km2 to many 100’s km2 or greater; and 4) Increase the productive depth range for economic geothermal energy extraction below the current 4 km limit by converting deep depleted and abandoned gas wells and fields into geothermal energy extraction wells. The first year of the proposed 3-year resource assessment covered an eight county region within the Delaware and Val Verde Basins of West Texas. This project has developed databases in Excel spreadsheet form that list over 8,000 temperature-depth recordings. These recordings come from header information listed on electric well logs recordings from various shallow to deep wells that were drilled for oil and gas exploration and production. The temperature-depth data is uncorrected and thus provides the lower temperature that is be expected to be encountered within the formation associated with the temperature-depth recording. Numerous graphs were developed from the data, all of which suggest that a log-normal solution for the thermal gradient is more descriptive of the data than a linear solution. A discussion of these plots and equations are presented within the narrative. Data was acquired that enable the determination of brine salinity versus brine density with the Permian Basin. A discussion on possible limestone and dolostone thermal conductivity parameters is presented with the purpose of assisting in determining heat flow and reservoir heat content for energy extraction. Subsurface maps of temperature either at a constant depth or within a target geothermal reservoir are discusse

  12. Analysis of eddy currents in a gradient coil J.M.B. Kroot

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    Analysis of eddy currents in a gradient coil J.M.B. Kroot Eindhoven University of Technology P in the tangential direction as well, due to eddy currents induced by other coils. In order to take the dependence, and the frequency is low enough to allow for a quasi­static approximation. Due to induction eddy currents occur

  13. Analysis of eddy currents in a gradient coil J.M.B. Kroot

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    Analysis of eddy currents in a gradient coil J.M.B. Kroot Eindhoven University of Technology P in the tangential direction as well, due to eddy currents induced by other coils. In order to take the dependence, and the frequency is low enough to allow for a quasi-static approximation. Due to induction eddy currents occur

  14. Stimulation Technologies for Deep Well Completions

    SciTech Connect (OSTI)

    Stephen Wolhart

    2005-06-30T23:59:59.000Z

    The Department of Energy (DOE) is sponsoring the Deep Trek Program targeted at improving the economics of drilling and completing deep gas wells. Under the DOE program, Pinnacle Technologies conducted a study to evaluate the stimulation of deep wells. The objective of the project was to review U.S. deep well drilling and stimulation activity, review rock mechanics and fracture growth in deep, high-pressure/temperature wells and evaluate stimulation technology in several key deep plays. This report documents results from this project.

  15. Development Wells At Salt Wells Area (Nevada Bureau of Mines...

    Open Energy Info (EERE)

    Salt Wells Area (Nevada Bureau of Mines and Geology, 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Development Wells At Salt Wells Area...

  16. Fast quantum algorithm for numerical gradient estimation

    E-Print Network [OSTI]

    Stephen P. Jordan

    2005-01-02T23:59:59.000Z

    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.

  17. Exploration of very high gradient cavities

    SciTech Connect (OSTI)

    Grigory Eremeev

    2011-07-01T23:59:59.000Z

    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.

  18. Feedback Mechanism for Microtubule Length Regulation by Stathmin Gradients

    E-Print Network [OSTI]

    Maria Zeitz; Jan Kierfeld

    2014-12-09T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Kimon Fountoulakis

    2014-12-30T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Y Narushima

    2011-09-28T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    2009-11-02T23:59:59.000Z

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

  2. BASIC GEOPHYSICAL FLUID Lecture 3: Gradient winds, pressure

    E-Print Network [OSTI]

    Read, Peter L.

    cyclostrophic balance. 2 #12;Example of gradient-wind balance: Hurricane Andrew 3 #12;Examples of cyclostrophic

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

    Open Energy Info (EERE)

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

  4. Energy Gradient Theory of Hydrodynamic Instability

    E-Print Network [OSTI]

    Hua-Shu Dou

    2005-01-29T23:59:59.000Z

    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.

  5. Evaluation of liquid lift approach to dual gradient

    E-Print Network [OSTI]

    Okafor, Ugochukwu Nnamdi

    2009-05-15T23:59:59.000Z

    ............................................... 4 2.2 Dual Gradient Drilling Method.............................................. 5 2.3 Methods of Achieving Dual Gradient Drilling ...................... 9 2.3.1 Subsea Mudlift Drilling... ................................................... 9 2.5 Schematic diagram of a modified subsea mudlift system .......................... 11 2.6 Hollow glass-spheres dual gradient drilling system................................... 13 2.7 A typical offshore drilling rig modified...

  6. Evaluation of liquid lift approach to dual gradient drilling

    E-Print Network [OSTI]

    Okafor, Ugochukwu Nnamdi

    2008-10-10T23:59:59.000Z

    ............................................... 4 2.2 Dual Gradient Drilling Method.............................................. 5 2.3 Methods of Achieving Dual Gradient Drilling ...................... 9 2.3.1 Subsea Mudlift Drilling... ................................................... 9 2.5 Schematic diagram of a modified subsea mudlift system .......................... 11 2.6 Hollow glass-spheres dual gradient drilling system................................... 13 2.7 A typical offshore drilling rig modified...

  7. USING SIMPLEX GRADIENTS OF NONSMOOTH FUNCTIONS IN DIRECT SEARCH METHODS

    E-Print Network [OSTI]

    Vicente, Luís Nunes

    USING SIMPLEX GRADIENTS OF NONSMOOTH FUNCTIONS IN DIRECT SEARCH METHODS A. L. CUST´ODIO , J. E by reordering the poll directions according to descent indicators built from simplex gradients. The purpose of this paper is twofold. First, we analyze the properties of simplex gradients of nonsmooth functions

  8. AN EXTENDED CLASS OF NONLINEAR CONJUGATE GRADIENT METHODS \\Lambda

    E-Print Network [OSTI]

    Yuan, Ya-xiang

    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

  9. AN AUGMENTED CONJUGATE GRADIENT METHOD FOR SOLVING CONSECUTIVE

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    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

  10. CONVERGENCE PROPERTIES OF NONLINEAR CONJUGATE GRADIENT METHODS1

    E-Print Network [OSTI]

    Yuan, Ya-xiang

    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

  11. Preconditioned Conjugate Gradient Methods for Three Dimensional Linear Elasticity

    E-Print Network [OSTI]

    Waterloo, University of

    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

  12. CG DESCENT, A CONJUGATE GRADIENT METHOD WITH GUARANTEED DESCENT

    E-Print Network [OSTI]

    Zhang, Hongchao

    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

  13. Exploiting Matrix Symmetry to Improve FPGA-Accelerated Conjugate Gradient

    E-Print Network [OSTI]

    Bakos, Jason D.

    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

  14. A conjugate gradient learning algorithm for recurrent neural networks

    E-Print Network [OSTI]

    Mak, Man-Wai

    ]. 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

  15. Well Monitoring Systems for EGS

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

    cost for well stimulation and improves reservoir tracking. * Well stimulation through hydro-fracturing is very expensive - Our system can be in the well before stimulation,...

  16. Abundance gradients in the Milky Way for alpha elements, Iron peak elements, Barium, Lanthanum and Europium

    E-Print Network [OSTI]

    G. Cescutti; F. Matteucci; P. Francois; C. Chiappini

    2006-09-29T23:59:59.000Z

    We model the abundance gradients in the disk of the Milky Way for several chemical elements (O, Mg, Si, S, Ca, Sc, Ti, Co, V, Fe, Ni, Zn, Cu, Mn, Cr, Ba, La and Eu), and compare our results with the most recent and homogeneous observational data. We adopt a chemical evolution model able to well reproduce the main properties of the solar vicinity. We compute, for the first time, the abundance gradients for all the above mentioned elements in the galactocentric distance range 4 - 22 kpc. The comparison with the observed data on Cepheids in the galactocentric distance range 5-17 kpc gives a very good agreement for many of the studied elements. In addition, we fit very well the data for the evolution of Lanthanum in the solar vicinity for which we present results here for the first time. We explore, also for the first time, the behaviour of the abundance gradients at large galactocentric distances by comparing our results with data relative to distant open clusters and red giants and select the best chemical evolution model model on the basis of that. We find a very good fit to the observed abundance gradients, as traced by Cepheids, for most of the elements, thus confirming the validity of the inside-out scenario for the formation of the Milky Way disk as well as the adopted nucleosynthesis prescriptions.

  17. Temperature, Temperature, Earth, geotherm for

    E-Print Network [OSTI]

    Treiman, Allan H.

    Temperature, Temperature, Earth, geotherm for total global heat flow Venus, geotherm for total global heat flow, 500 Ma #12;Temperature, Temperature, #12;Earth's modern regional continental geotherms Venusian Geotherms, 500 Ma Temperature, Temperature, After Blatt, Tracy, and Owens Petrology #12;Ca2Mg5Si8

  18. Stimulation Technologies for Deep Well Completions

    SciTech Connect (OSTI)

    None

    2003-09-30T23:59:59.000Z

    The Department of Energy (DOE) is sponsoring the Deep Trek Program targeted at improving the economics of drilling and completing deep gas wells. Under the DOE program, Pinnacle Technologies is conducting a study to evaluate the stimulation of deep wells. The objective of the project is to assess U.S. deep well drilling & stimulation activity, review rock mechanics & fracture growth in deep, high pressure/temperature wells and evaluate stimulation technology in several key deep plays. An assessment of historical deep gas well drilling activity and forecast of future trends was completed during the first six months of the project; this segment of the project was covered in Technical Project Report No. 1. The second progress report covers the next six months of the project during which efforts were primarily split between summarizing rock mechanics and fracture growth in deep reservoirs and contacting operators about case studies of deep gas well stimulation.

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

    E-Print Network [OSTI]

    Codina Cotar; Jean-Dominique Deuschel; Stefan Müller

    2008-01-08T23:59:59.000Z

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

  20. Ducted kinetic Alfven waves in plasma with steep density gradients

    SciTech Connect (OSTI)

    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

    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.

  1. Recompletion Report for Well UE-10j

    SciTech Connect (OSTI)

    M. J. Townsend

    2000-05-01T23:59:59.000Z

    Existing Well UE-10j was deepened and recompleted for the U.S. Department of Energy, Nevada Operations Office in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. The well was originally drilled to a total depth of 725.4 meters in 1965 for use as a hydrologic test hole in the northern portion of Yucca Flat in Area 8 of the Nevada Test Site. The well is located up-gradient of the Yucca Flat underground test area and penetrates deep into the Paleozoic rocks that form the lower carbonate aquifer of the NTS and surrounding areas. The original 24.4-centimeter-diameter borehole was drilled to a depth of 725.4 meters and left uncompleted. Water-level measurements were made periodically by the U.S. Geological Survey, but access to the water table was lost between 1979 and 1981 due to hole sloughing. In 1993, the hole was opened to 44.5 centimeters and cased off to a depth of 670.0 meters. The hole diameter was then decreased to 31.1 centimeters for drilling to a total depth of 796.4 meters. The depth to water in the open borehole was measured at 658.7 meters on March 18, 1993.

  2. Single-Well and Cross-Well Seismic At Salt Wells Area (Bureau...

    Open Energy Info (EERE)

    Seismic At Salt Wells Area (Bureau of Land Management, 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Single-Well and Cross-Well Seismic...

  3. The gradient flow running coupling scheme

    E-Print Network [OSTI]

    Zoltan Fodor; Kieran Holland; Julius Kuti; Daniel Nogradi; Chik Him Wong

    2012-11-14T23:59:59.000Z

    The Yang-Mills gradient flow in finite volume is used to define a running coupling scheme. As our main result the discrete beta-function, or step scaling function, is calculated for scale change s=3/2 at several lattice spacings for SU(3) gauge theory coupled to N_f = 4 fundamental massless fermions. The continuum extrapolation is performed and agreement is found with the continuum perturbative results for small renormalized coupling. The case of SU(2) gauge group is briefly commented on.

  4. Steep Gradient Flume | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro Industries Pvt LtdShawangunk,SoutheastSt.Steep Gradient Flume Jump to: navigation, search

  5. Dielectric-Lined High-Gradient Accelerator Structure

    SciTech Connect (OSTI)

    Jay L. Hirshfield

    2012-04-24T23:59:59.000Z

    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.

  6. Well-pump alignment system

    DOE Patents [OSTI]

    Drumheller, Douglas S. (Cedar Crest, NM)

    1998-01-01T23:59:59.000Z

    An improved well-pump for geothermal wells, an alignment system for a well-pump, and to a method for aligning a rotor and stator within a well-pump, wherein the well-pump has a whistle assembly formed at a bottom portion thereof, such that variations in the frequency of the whistle, indicating misalignment, may be monitored during pumping.

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

    SciTech Connect (OSTI)

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

    2013-12-16T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

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

    2000-01-01T23:59:59.000Z

    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.

  9. Well Permits (District of Columbia)

    Broader source: Energy.gov [DOE]

    Well permits are required for the installation of wells in private and public space. Wells are defined as any trest hole, shaft, or soil excavation created by any means including, but not limited...

  10. Radial convection of finite ion temperature, high amplitude plasma blobs

    SciTech Connect (OSTI)

    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

    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.

  11. High gradient lens for charged particle beam

    DOE Patents [OSTI]

    Chen, Yu-Jiuan

    2014-04-29T23:59:59.000Z

    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.

  12. Constant field gradient planar coupled cavity structure

    DOE Patents [OSTI]

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

    1999-07-27T23:59:59.000Z

    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.

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

    Open Energy Info (EERE)

    Zacharakis, 1981) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Waunita Hot Springs Geothermal Area (Zacharakis,...

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

    E-Print Network [OSTI]

    Hui Zhang

    2013-03-20T23:59:59.000Z

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

  15. 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...

  16. 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...

  17. Spatiotemporal Gradient Modeling with Applications Harrison S. Quick1

    E-Print Network [OSTI]

    Carlin, Bradley P.

    , 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

  18. On the application of the spectral projected gradient method in ...

    E-Print Network [OSTI]

    2015-02-17T23:59:59.000Z

    On the application of the spectral projected gradient method in image segmentation. 7. (a) cameraman – 204 × 204. (b) carplate – 285 × 224. (c) granite – 225 × ...

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

    E-Print Network [OSTI]

    2011-11-08T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    2015-01-22T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    Y Narushima

    2009-12-03T23:59:59.000Z

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

  2. Optimization Online - Linearizing the Method of Conjugate Gradients

    E-Print Network [OSTI]

    Serge Gratton

    2012-09-09T23:59:59.000Z

    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 ...

  3. A Perry Descent Conjugate Gradient Method with Restricted Spectrum

    E-Print Network [OSTI]

    Dongyi Liu

    2011-03-07T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    Elias S. Helou

    2015-03-18T23:59:59.000Z

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

  5. Concentration Gradient and Information Energy for Decentralized UAV Control1

    E-Print Network [OSTI]

    Mohseni, Kamran

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

  6. 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 -...

  7. High Gradient Inverse Free Electron Laser (IFEL) Accelerator

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

    Gradient High energy gain Inverse Free Electron Laser P. Musumeci UCLA Department of Physics and Astronomy On Behalf of the RUBICON collaboration ATF user meeting, BNL, October 6...

  8. 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...

  9. An accelerated proximal gradient algorithm for nuclear norm ...

    E-Print Network [OSTI]

    Kim-Chuan Toh

    2009-03-27T23:59:59.000Z

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

  10. 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 1991 - 1991 Usefulness not useful DOE-funding Unknown...

  11. 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...

  12. 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...

  13. 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...

  14. High-gradient compact linear accelerator

    DOE Patents [OSTI]

    Carder, B.M.

    1998-05-26T23:59:59.000Z

    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.

  15. Well-pump alignment system

    DOE Patents [OSTI]

    Drumheller, D.S.

    1998-10-20T23:59:59.000Z

    An improved well-pump for geothermal wells, an alignment system for a well-pump, and to a method for aligning a rotor and stator within a well-pump are disclosed, wherein the well-pump has a whistle assembly formed at a bottom portion thereof, such that variations in the frequency of the whistle, indicating misalignment, may be monitored during pumping. 6 figs.

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

    SciTech Connect (OSTI)

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

    1988-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Parnell, Steven R.; Deppe, Martin H.; Ajraoui, Salma; Parra-Robles, Juan; Wild, Jim M. [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

    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.

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

    SciTech Connect (OSTI)

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

    2011-01-01T23:59:59.000Z

    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.

  19. Geothermal low-temperature reservoir assessment in Dona Ana County, New Mexico. Final report

    SciTech Connect (OSTI)

    Icerman, L.; Lohse, R.L.

    1983-04-01T23:59:59.000Z

    Sixty-four shallow temperature gradient holes were drilled on the Mesilla Valley East Mesa (east of Interstate Highways 10 and 25), stretching from US Highway 70 north of Las Cruces to NM Highway 404 adjacent to Anthony, New Mexico. Using these data as part of the site selection process, Chaffee Geothermal, Ltd. of Denver, Colorado, drilled two low-temperature geothermal production wells to the immediate north and south of Tortugas Mountain and encountered a significant low-temperature reservoir, with a temperature of about 150{sup 0}F and flow rates of 750 to 1500 gallons per minute at depths from 650 to 1250 feet. These joint exploration activities resulted in the discovery and confirmation of a 30-square-mile low-temperature geothermal anomaly just a few miles to the east of Las Cruces that has been newly named as the Las Cruces east Mesa Geothermal Field. Elevated temperature and heat flow data suggest that the thermal anomaly is fault controlled and extends southward to the Texas border covering a 100-square-mile area. With the exception of some localized perturbations, the anomaly appears to decrease in temperature from the north to the south. Deeper drilling is required in the southern part of the anomaly to confirm the existence of commercially-exploitable geothermal waters.

  20. Low Temperature Geothermal Resource Evaluation of the Moses Lake-Ritzville-Connell Area, Washington

    SciTech Connect (OSTI)

    Widness, Scott

    1983-11-01T23:59:59.000Z

    The study area is located in portions of Adams, Grant, Lincoln, and Franklin counties of eastern Washington. The area is representative of a complex stratigraphic and geohydrologic system within the basalt flows of the Columbia River Basalt Group. The regional piezometric surface and stratigraphic units dip towards the southwest. Fluid temperature data were collected by three different agencies. The Geological Engineering Section (WSU) at Washington State University, runs a continuous fluid temperature (FT) log as part of a complete suite of geophysical logs. The US Geological Survey (USGS) runs a continuous fluid FT log in conjunction with caliper and natural-gamma logs. Southern Methodist University (SMU) and the Washington State Department of Natural Resources, Division of Geology and Earth Resources (DNR), have cooperated in gathering FT data. The DNR-SMU data were collected by taking temperature measurements at 5 m intervals. Bottom-hole temperatures (BHT) and bottom-hole depths (BHD) of selected wells in the study area are given in table 2. Some of the BHT data in table 2 may vary from those previously reported by WSU. These discrepancies are the result of changes in the calibration method of the FT tool. A technique developed by Giggane (1982) was used to determine the geothermal gradients within the area. A least squares linear regression analysis of the relationship between the BHT and BHD was used to determine the geothermal gradient of a given well data group (WDG). Well data groups were selected on the premises of geographic proximity, position within the regional groundwater flow system, land slope azimuth, and land slope dip. Some data points have been excluded from the linear regression analysis on the basis of factors such as duplicate logging of the same hole, down-hole flow, holes not logged to total depth, and questionable FT tool responses.

  1. Soda Lake Well Lithology Data and Geologic Cross-Sections

    SciTech Connect (OSTI)

    Faulds, James E.

    2013-12-31T23:59:59.000Z

    Comprehensive catalogue of drill?hole data in spreadsheet, shapefile, and Geosoft database formats. Includes XYZ locations of well heads, year drilled, type of well, operator, total depths, well path data (deviations), lithology logs, and temperature data. Plus, 13 cross?sections in Adobe Illustrator format.

  2. Horizontal well turbulizer and method

    SciTech Connect (OSTI)

    Hopmann, M.E.

    1990-03-20T23:59:59.000Z

    This patent describes an apparatus for securement onto one end of a continuous length of remedial tubing introduceable into a subterranean well and concentrically insertable through production tubing previously positioned within the well. The well having a deviated configuration including an entry portion communicating with a curved portion extending downwardly in the well from the entry portion, and a generally linear end portion traversable with a production formation.

  3. SampleRank: Training Factor Graphs with Atomic Gradients

    E-Print Network [OSTI]

    McCallum, Andrew

    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

  4. The Simplex Gradient and Noisy Optimization Problems \\Lambda

    E-Print Network [OSTI]

    The Simplex Gradient and Noisy Optimization Problems \\Lambda D. M. Bortz C. T. Kelley North the simplex gradient from [14], the first order estimates it satisfies, and its application to the Nelder/or exploit parallelism. The algorithms we discuss in this paper all examine a simplex of points in R N

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

    E-Print Network [OSTI]

    Shvartsman, Stanislav "Stas"

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

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

    E-Print Network [OSTI]

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

  7. Combining Conjugate Direction Methods with Stochastic Approximation of Gradients

    E-Print Network [OSTI]

    Schraudolph, Nicol N.

    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

  8. Combining Conjugate Direction Methods with Stochastic Approximation of Gradients

    E-Print Network [OSTI]

    Schraudolph, Nicol N.

    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

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

    E-Print Network [OSTI]

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

    2010-08-17T23:59:59.000Z

    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.

  10. Well having inhibited microbial growth

    DOE Patents [OSTI]

    Lee, Brady D.; Dooley, Kirk J.

    2006-08-15T23:59:59.000Z

    The invention includes methods of inhibiting microbial growth in a well. A packing material containing a mixture of a first material and an antimicrobial agent is provided to at least partially fill a well bore. One or more access tubes are provided in an annular space around a casing within the well bore. The access tubes have a first terminal opening located at or above a ground surface and have a length that extends from the first terminal opening at least part of the depth of the well bore. The access tubes have a second terminal opening located within the well bore. An antimicrobial material is supplied into the well bore through the first terminal opening of the access tubes. The invention also includes well constructs.

  11. A compact high-performance low-field NMR apparatus for measurements on fluids at very high pressures and temperatures

    SciTech Connect (OSTI)

    Freedman, R.; Anand, V., E-mail: VAnand@slb.com; Ganesan, K.; Tabrizi, P.; Torres, R. [Schlumberger Technology Corp., 110 Schlumberger Drive, Sugar Land, Texas 77478 (United States)] [Schlumberger Technology Corp., 110 Schlumberger Drive, Sugar Land, Texas 77478 (United States); Grant, B. [Grant Innovation, 618 Mesquite Drive, Cedar Creek, Texas 78612 (United States)] [Grant Innovation, 618 Mesquite Drive, Cedar Creek, Texas 78612 (United States); Catina, D. [National Oilwell Varco, 10302 Mula Road, Stafford, Texas 77477 (United States)] [National Oilwell Varco, 10302 Mula Road, Stafford, Texas 77477 (United States); Ryan, D.; Borman, C.; Krueckl, C. [Schlumberger DBR Technology Center, 9450–17 Avenue NW, Edmonton, Alberta (Canada)] [Schlumberger DBR Technology Center, 9450–17 Avenue NW, Edmonton, Alberta (Canada)

    2014-02-15T23:59:59.000Z

    We discuss an innovative new high-performance apparatus for performing low-field Nuclear Magnetic Resonance (NMR) relaxation times and diffusion measurements on fluids at very high pressures and high temperatures. The apparatus sensor design and electronics specifications allow for dual deployment either in a fluid sampling well logging tool or in a laboratory. The sensor and electronics were designed to function in both environments. This paper discusses the use of the apparatus in a laboratory environment. The operating temperature and pressure limits, and the signal-to-noise ratio (SNR) of the new system exceed by a very wide margin what is currently possible. This major breakthrough was made possible by a revolutionary new sensor design that breaks many of the rules of conventional high pressure NMR sensor design. A metallic sample holder capable of operating at high pressures and temperatures is provided to contain the fluid under study. The sample holder has been successfully tested for operation up to 36 Kpsi. A solenoid coil wound on a slotted titanium frame sits inside the metallic sample holder and serves as an antenna to transmit RF pulses and receive NMR signals. The metal sample holder is sandwiched between a pair of gradient coils which provide a linear field gradient for pulsed field gradient diffusion measurements. The assembly sits in the bore of a low-gradient permanent magnet. The system can operate over a wide frequency range without the need for tuning the antenna to the Larmor frequency. The SNR measured on a water sample at room temperature is more than 15 times greater than that of the commercial low-field system in our laboratory. Thus, the new system provides for data acquisition more than 200 times faster than was previously possible. Laboratory NMR measurements of relaxations times and diffusion coefficients performed at pressures up to 25 Kpsi and at temperatures up to 175?°C with crude oils enlivened with dissolved hydrocarbon gases (referred to as “live oils”) are shown. This is the first time low-field NMR measurements have been performed at such high temperatures and pressures on live crude oil samples. We discuss the details of the apparatus design, tuning, calibration, and operation. NMR data acquired at multiple temperatures and pressures on a live oil sample are discussed.

  12. Natural Conjugate Gradient on Complex Flag Manifolds for Complex Independent Subspace

    E-Print Network [OSTI]

    Plumbley, Mark

    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

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

    E-Print Network [OSTI]

    Beltran-Royo, Cesar

    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

  14. Effect of Gas Turbine Exhaust Temperature, Stack Temperature and Ambient Temperature on Overall Efficiency of Combine Cycle Power Plant

    E-Print Network [OSTI]

    unknown authors

    Abstract—The gas turbine exhaust temperature, stack temperature and ambient temperature play a very important role during the predication of the performance of combine cycle power plant. This paper covers parametric analysis of effects of gas turbine exhaust temperature, stack temperature and ambient temperature on the overall efficiency of combine cycle power plant keeping the gas turbine efficiency as well as steam turbine efficiency constant. The results shows that out of three variables i.e. turbine exhaust temperature, stack temperature and ambient temperature, the most dominating factor of increasing the overall efficiency of the combine cycle power plant is the stack temperature.

  15. Well Monitoring System for EGS

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

    Peer Review Well Monitoring Systems for EGS Principal Investigator Randy Normann Perma Works LLC May 19, 2010 This presentation does not contain any proprietary confidential, or...

  16. Abundance gradients in the Milky Way for alpha elements, Iron peak elements, Barium, Lanthanum and Europium

    E-Print Network [OSTI]

    Cescutti, G; François, P; Chiappini, C

    2006-01-01T23:59:59.000Z

    We model the abundance gradients in the disk of the Milky Way for several chemical elements (O, Mg, Si, S, Ca, Sc, Ti, Co, V, Fe, Ni, Zn, Cu, Mn, Cr, Ba, La and Eu), and compare our results with the most recent and homogeneous observational data. We adopt a chemical evolution model able to well reproduce the main properties of the solar vicinity. We compute, for the first time, the abundance gradients for all the above mentioned elements in the galactocentric distance range 4 - 22 kpc. The comparison with the observed data on Cepheids in the galactocentric distance range 5-17 kpc gives a very good agreement for many of the studied elements. In addition, we fit very well the data for the evolution of Lanthanum in the solar vicinity for which we present results here for the first time. We explore, also for the first time, the behaviour of the abundance gradients at large galactocentric distances by comparing our results with data relative to distant open clusters and red giants and select the best chemical evol...

  17. Finite Temperature Effective Actions

    E-Print Network [OSTI]

    Ashok Das; J. Frenkel

    2009-08-27T23:59:59.000Z

    We present, from first principles, a direct method for evaluating the exact fermion propagator in the presence of a general background field at finite temperature, which can be used to determine the finite temperature effective action for the system. As applications, we determine the complete one loop finite temperature effective actions for 0+1 dimensional QED as well as the Schwinger model. These effective actions, which are derived in the real time (closed time path) formalism, generate systematically all the Feynman amplitudes calculated in thermal perturbation theory and also show that the retarded (advanced) amplitudes vanish in these theories.

  18. Progress Toward Luminescence-Based VAATE Turbine Blade And Vane Temperature Measurement

    SciTech Connect (OSTI)

    Jenkins, Tom P. [Metrolaser Corporation; Allison, Stephen W [ORNL; Eldridge, Jeffrey I. [NASA-Glenn Research Center, Cleveland; Niska, R. H. [Honeywell Aerospace Services; Condevaux, J. J. [Williams International; Wolfe, Doug E. [Pennsylvania State University; Jordan, Eric H. [University of Connecticut, Storrs; Heeg, Bauke [Lumium

    2012-01-01T23:59:59.000Z

    Progress towards fielding luminescence-based temperature measurements for the Versatile Affordable Advanced Turbine Engine (VAATE) program is described. The near term programmatic objective is to monitor turbine vane temperatures and health by luminescence from a rare-earth doped thermal barrier coating (TBC), or from a thermographic phosphor layer coated onto a TBC. The first goal is to establish the temperature measurement capability to 1300 C with 1 percent uncertainty in a test engine. An eventual goal is to address rotating turbine blades in an F135 engine. The project consists of four phases, of which the first two have been completed and are described in this paper. The first phase involved laser heating of a 2.54-cm-diameter test sample, coated with a TBC and a thermographic phosphor layer, to produce a thermal gradient across the TBC layer similar to that expected in a turbine engine. Phosphor temperatures correlated well with those measured by long wavelength pyrometry. In the second phase, 10x10- cm coupons were exposed to a jet fuel flame at a burner rig facility. The thermographic phosphor/TBC combination survived the aggressive flame and high exhaust gas velocity, even though the metal substrate melted. Reliable temperature measurements were made up to about 1400 C using YAG:Dy as the thermographic phosphor. In addition, temperature measurements using YAG:Tm showed very desirable background radiation suppression.

  19. Efficient and robust gradient enhanced Kriging emulators.

    SciTech Connect (OSTI)

    Dalbey, Keith R.

    2013-08-01T23:59:59.000Z

    %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.

  20. Imaging diffusion with non-uniform B{sub 1} gradients.

    SciTech Connect (OSTI)

    Woelk, K.

    1998-01-30T23:59:59.000Z

    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.

  1. Well descriptions for geothermal drilling

    SciTech Connect (OSTI)

    Carson, C.C.; Livesay, B.J.

    1981-01-01T23:59:59.000Z

    Generic well models have been constructed for eight major geothermal resource areas. The models define representative times and costs associated with the individual operations that can be expected during drilling and completion of geothermal wells. They were made for and have been used to evaluate the impacts of potential new technologies. Their nature, their construction, and their validation are discussed.

  2. Optimization of fractured well performance of horizontal gas wells

    E-Print Network [OSTI]

    Magalhaes, Fellipe Vieira

    2009-06-02T23:59:59.000Z

    In low-permeability gas reservoirs, horizontal wells have been used to increase the reservoir contact area, and hydraulic fracturing has been further extending the contact between wellbores and reservoirs. This thesis presents an approach...

  3. Gradient projection anti-windup scheme

    E-Print Network [OSTI]

    Teo, Chun Sang Justin

    2011-01-01T23:59:59.000Z

    It is a well-recognized fact that control saturation affects virtually all practical control systems. It leads to controller windup, which degrades/limits the system's closed-loop performance, and may cause catastrophic ...

  4. HTS High Gradient Magnetic Separation system

    SciTech Connect (OSTI)

    Daugherty, M.A.; Coulter, J.Y.; Hults, W.L. [and others

    1996-09-01T23:59:59.000Z

    We report on the assembly, characterization and operation of a high temperature superconducting (HTS) magnetic separator. The magnet is made of 624 m of Silver/BSCCO superconducting wire and has overall dimensions of 18 cm OD, 15.5 cm height and 5 cm ID. The HTS current leads are designed to operate with the warm end at 75 K and the cold end cooled by a two stage Gifford-McMahon cryocooler. The upper stage of the cryocooler cools the thermal shield and two heat pipe thermal intercepts. The lower stage of the cryocooler cools the HTS magnet and the bottom end of the HTS current leads. The HTS magnet was initially characterized in liquid cryogens. We report on the current- voltage (I-V) characteristics of the HTS magnet at temperatures ranging from 15 to 40 K. At 40 K the magnet can generate a central field of 2.0 T at a current of 120 A.

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

    E-Print Network [OSTI]

    Nocedal, Jorge

    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

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

    E-Print Network [OSTI]

    MacLachlan, Scott

    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

  7. Bond Strength Degradation for CFRP and Steel reinforcing Bars in Concrete at Elevated Temperature 

    E-Print Network [OSTI]

    Maluk, Cristian; Bisby, Luke; Terrasi, Giovanni; Green, Mark

    2011-03-01T23:59:59.000Z

    temperature is a complex phenomenon which is influenced by a number of interrelated factors, including the type of prestressing, degradation of the concrete, CFRP, and steel, differential thermal expansion, thermal gradients and stresses, release of moisture...

  8. Modelling Flow through Porous Media under Large Pressure Gradients

    E-Print Network [OSTI]

    Srinivasan, Shriram

    2013-11-01T23:59:59.000Z

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

  9. Distributed Kalman filtering compared to Fourier domain preconditioned conjugate gradient

    E-Print Network [OSTI]

    Greer, Julia R.

    Distributed Kalman filtering compared to Fourier domain preconditioned conjugate gradient for laser of the tomography problem. The second algorithm is the distributed Kalman filter (DKF) developed by Massioni et al

  10. Colour Gradients in the Optical and Near-IR

    E-Print Network [OSTI]

    Roelof S. de Jong

    1995-09-01T23:59:59.000Z

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

  11. 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...

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

    E-Print Network [OSTI]

    Fredrik Carlsson

    2008-02-29T23:59:59.000Z

    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 ...

  13. Function of the anterior gradient protein family in cancer 

    E-Print Network [OSTI]

    Fourtouna, Argyro

    2009-01-01T23:59:59.000Z

    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...

  14. 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...

  15. Energy Flow in Extended Gradient Partial Differential Equations

    E-Print Network [OSTI]

    Energy Flow in Extended Gradient Partial Differential Equations Th. Gallay S. Slijepâ??atiment 425 BijeniŸcka 30 F­91405 Orsay, France 10000 Zagreb, Croatia Thierry.Gallay@math.u­psud.fr slijepce

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

    E-Print Network [OSTI]

    2011-06-15T23:59:59.000Z

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

  17. Spatial gradient of protein phosphorylation underlies replicative bacterium

    E-Print Network [OSTI]

    Chen, Y. Erin

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

  18. A HIGH GRADIENT QUADRUPOLE MAGNET FOR THE SSC

    E-Print Network [OSTI]

    Taylor, C.

    2010-01-01T23:59:59.000Z

    on gradient and qu;;lity, if the buss grooves are located atto accommodate the m;;! in current buss, the lowp.r ']roovewIring and corrector buss, and thp. symmetrically-placed

  19. 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...

  20. Sequential high temperature reduction, low temperature hydrolysis...

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

    high temperature reduction, low temperature hydrolysis for the regeneration of sulfated NOx trap catalysts. Sequential high temperature reduction, low temperature hydrolysis for...

  1. Quantum well multijunction photovoltaic cell

    DOE Patents [OSTI]

    Chaffin, R.J.; Osbourn, G.C.

    1983-07-08T23:59:59.000Z

    A monolithic, quantum well, multilayer photovoltaic cell comprises a p-n junction comprising a p-region on one side and an n-region on the other side, each of which regions comprises a series of at least three semiconductor layers, all p-type in the p-region and all n-type in the n-region; each of said series of layers comprising alternating barrier and quantum well layers, each barrier layer comprising a semiconductor material having a first bandgap and each quantum well layer comprising a semiconductor material having a second bandgap when in bulk thickness which is narrower than said first bandgap, the barrier layers sandwiching each quantum well layer and each quantum well layer being sufficiently thin that the width of its bandgap is between said first and second bandgaps, such that radiation incident on said cell and above an energy determined by the bandgap of the quantum well layers will be absorbed and will produce an electrical potential across said junction.

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

    E-Print Network [OSTI]

    Lin, Wanchuan

    2006-01-01T23:59:59.000Z

    R. 1985. “Social Class Inequality in Mortality from 1921 toin the Gradient: Health Inequality Among Infants Wanchuanin the Gradient: Health Inequality Among Infants * Wanchuan

  3. Mass Function Gradients and the Need for Dark Matter

    E-Print Network [OSTI]

    Jason A. Taylor

    1998-03-05T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

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

    2010-03-02T23:59:59.000Z

    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.

  5. High temperature behavior of metallic inclusions in uranium dioxide

    SciTech Connect (OSTI)

    Yang, R.L.

    1980-08-01T23:59:59.000Z

    The object of this thesis was to construct a temperature gradient furnace to simulate the thermal conditions in the reactor fuel and to study the migration of metallic inclusions in uranium oxide under the influence of temperature gradient. No thermal migration of molybdenum and tungsten inclusions was observed under the experimental conditions. Ruthenium inclusions, however, dissolved and diffused atomically through grain boundaries in slightly reduced uranium oxide. An intermetallic compound (probably URu/sub 3/) was formed by reaction of Ru and UO/sub 2-x/. The diffusivity and solubility of ruthenium in uranium oxide were measured.

  6. Harvesting RNA from 3-D Acinar Cultures 1) Aspirate the media from the wells for harvesting.

    E-Print Network [OSTI]

    Harvesting RNA from 3-D Acinar Cultures 1) Aspirate the media from the wells for harvesting. 2) Add for 15 minutes at room temperature with approximately 20 l DEPC water (for 4 wells of an 8 well chamber

  7. Interlocked optimization and fast gradient algorithm for a seismic inverse problem

    SciTech Connect (OSTI)

    Metivier, Ludovic, E-mail: ludovic.metivier@gmail.com [LAGA, Universite Paris XIII, 99 Avenue Jean-Baptiste Clement, 93000 Epinay-Villetaneuse (France)

    2011-08-10T23:59:59.000Z

    Highlights: {yields} A 2D extension of the 1D nonlinear inversion of well-seismic data is given. {yields} Appropriate regularization yields a well-determined large scale inverse problem. {yields} An interlocked optimization loop acts as an efficient preconditioner. {yields} The adjoint state method is used to compute the misfit function gradient. {yields} Domain decomposition method yields an efficient parallel implementation. - Abstract: We give a nonlinear inverse method for seismic data recorded in a well from sources at several offsets from the borehole in a 2D acoustic framework. Given the velocity field, approximate values of the impedance are recovered. This is a 2D extension of the 1D inversion of vertical seismic profiles . The inverse problem generates a large scale undetermined ill-conditioned problem. Appropriate regularization terms render the problem well-determined. An interlocked optimization algorithm yields an efficient preconditioning. A gradient algorithm based on the adjoint state method and domain decomposition gives a fast parallel numerical method. For a realistic test case, convergence is attained in an acceptable time with 128 processors.

  8. High Temperature Capacitor Development

    SciTech Connect (OSTI)

    John Kosek

    2009-06-30T23:59:59.000Z

    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.

  9. Self-potential, soil co2 flux, and temperature on masaya volcano, nicaragua

    SciTech Connect (OSTI)

    Lewicki, J.L.; Connor, C.; St-Amand, K.; Stix, J.; Spinner, W.

    2003-07-01T23:59:59.000Z

    We investigate the spatial relationship between self-potential (SP), soil CO{sub 2} flux, and temperature and the mechanisms that produce SP anomalies on the flanks of Masaya volcano, Nicaragua. We measured SP, soil CO{sub 2} fluxes (<1 to 5.0 x 10{sup 4} g m{sup -2} d{sup -1}), and temperatures (26 to 80 C) within an area surrounding a normal fault, adjacent to Comalito cinder cone (2002-2003). These variables are well spatially correlated. Wavelengths of SP anomalies are {le}100 m, and high horizontal SP gradients flank the region of elevated flux and temperature. Carbon isotopic compositions of soil CO{sub 2} ({delta}{sup 13}C = -3.3 to -1.1{per_thousand}) indicate a deep gas origin. Given the presence of a deep water table (100 to 150 m), high gas flow rates, and subsurface temperatures above liquid boiling points, we suggest that rapid fluid disruption is primarily responsible for positive SP anomalies here. Concurrent measurement of SP, soil CO{sub 2} flux, and temperature may be a useful tool to monitor intrusive activity.

  10. Sampling for Bacteria in Wells

    E-Print Network [OSTI]

    Lesikar, Bruce J.

    2001-11-15T23:59:59.000Z

    Sampling for Bacteria in Wells E-126 11/01 Water samples for bacteria tests must always be col- lected in a sterile container. The procedure for collect- ing a water sample is as follows: 1. Obtain a sterile container from a Health Department...

  11. Process for cementing geothermal wells

    DOE Patents [OSTI]

    Eilers, Louis H. (Inola, OK)

    1985-01-01T23:59:59.000Z

    A pumpable slurry of coal-filled furfuryl alcohol, furfural, and/or a low molecular weight mono- or copolymer thereof containing, preferably, a catalytic amount of a soluble acid catalyst is used to cement a casing in a geothermal well.

  12. Detection of On-chip Temperature Gradient Using a 1.5V Low Power CMOS Temperature Sensor

    E-Print Network [OSTI]

    Maryland at College Park, University of

    and increasing package density cause self-heating of chips to become an important factor. Self-heating induces

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

    E-Print Network [OSTI]

    2010-01-01T23:59:59.000Z

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

  14. Electron-beam envelopes and matching for a combined wiggler and alternating-gradient quadrupole channel

    SciTech Connect (OSTI)

    Wang, T.F.; Cooper, R.K.

    1985-01-01T23:59:59.000Z

    This work studies the electron-beam envelopes and matching for a combined wiggler and alternating-gradient quadrupole field for a free-electron laser (FEL) that will be operated in the VUV or XUV wavelength region. The quadrupole field is assumed to vary continuously along the symmetry axis. The linearized equations of electron motion are solved analytically by using the two-scale perturbation method for a plane polarized wiggler. The electron-beam envelopes and the envelope equations, as well as the matching conditions in phase space, are obtained from the electron trajectories. A comparison with the numerical solution is presented.

  15. Determination of DNA Melting Temperatures in Diffusion-Generated Chemical Gradients

    E-Print Network [OSTI]

    Ludwig-Maximilians-Universität, München

    material for artificial supramolecular structures and devices.1 In many cases, the TM of a DNA or RNA

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

    E-Print Network [OSTI]

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

    2001-01-01T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Sano, Masaki

    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

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

    E-Print Network [OSTI]

    Lin, Zhihong

    %, 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

  19. TRANSIENT NUMERICAL STUDY OF TEMPERATURE GRADIENTS DURING SUBLIMATION GROWTH OF SiC

    E-Print Network [OSTI]

    mathematical heat transfer model including heat conduction, radiation, and radio frequency (RF) induction

  20. The effect of gradients of temperature of the sea surface on moving groups of cumulus clouds

    E-Print Network [OSTI]

    Stearns, John Robb

    1971-01-01T23:59:59.000Z

    Vl I 4 ~ CO 0 C-l W Cl E1 +~ Q'0 51 Fr O hr'1 Cl Cl rQ Vl r. 0 v, 0 v 0 -8 611 v O bQ O~ Dv Q '0 C3 M 5. D Cd M Or 0 Q Q v- -P 4M 0 0 0 0 m 0 m 4" 5 P O lrl Q -P . r OQ 0~ C', CO Or-P Q P +' C' 0'v Q rQ Q Q Q Cvm4 55 H...

  1. A new well surveying tool

    E-Print Network [OSTI]

    Haghighi, Manuchehr Mehdizabeh

    1966-01-01T23:59:59.000Z

    A NEW WELL SURVEYING TOOL A Thesis By MANUCHEHR MEHDIZABEH HAGHIGHI Submitted to the Graduate College of the Texas ANM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Major Subject: PETROLEUM... by Surveying Device for S and 19 , N and 41 . 21 3. Comparison of Measured Angles and Angles Indicated by Surveying Device for NE snd 9 , W and 45 . . . . . . . ~ 22 ABSTRNl T Ever since the advent of rotary drilling the petroleum industry has been...

  2. Flexible Macroscopic Models for Dense-Fluid Shockwaves: Partitioning Heat and Work; Delaying Stress and Heat Flux; Two-Temperature Thermal Relaxation

    E-Print Network [OSTI]

    Wm. G. Hoover; Carol G. Hoover; Francisco J. Uribe

    2010-05-10T23:59:59.000Z

    Macroscopic models which distinguish the longitudinal and transverse temperatures can provide improved descriptions of the microscopic shock structures as revealed by molecular dynamics simulations. Additionally, we can include three relaxation times in the models, two based on Maxwell's viscoelasticity and its Cattaneo-equation analog for heat flow, and a third thermal, based on the Krook-Boltzmann equation. This approach can replicate the observed lags of stress (which lags behind the strain rate) and heat flux (which lags behind the temperature gradient), as well as the eventual equilibration of the two temperatures. For profile stability the time lags cannot be too large. By partitioning the longitudinal and transverse contributions of work and heat and including a tensor heat conductivity and bulk viscosity, all the qualitative microscopic features of strong simple-fluid shockwave structures can be reproduced.

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

    E-Print Network [OSTI]

    Schraudolph, Nicol N.

    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

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

    E-Print Network [OSTI]

    Schneider, Jean-Guy

    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

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

    E-Print Network [OSTI]

    Yang, Jianke

    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

  6. A NONLINEAR CONJUGATE GRADIENT METHOD WITH A STRONG GLOBAL CONVERGENCE PROPERTY

    E-Print Network [OSTI]

    Yuan, Ya-xiang

    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

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

    E-Print Network [OSTI]

    Zhang, Hongchao

    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

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

    E-Print Network [OSTI]

    McCallum, Andrew

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

  9. Quasi-linear gradients for capillary liquid chromatography with mass and tandem mass

    E-Print Network [OSTI]

    Dabiri, John O.

    Gradient elution, capillary liquid chromatography mass spectrometry was performed with linear, static the use of additional valves, mixers, pumps or software. It took less than 10 minutes to form a gradient-line as static gradients.12­14 The technique of forming static gradients was first proposed by Ishii and co

  10. Investigations of low-temperature geothermal potential in New York State

    SciTech Connect (OSTI)

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

    1981-09-01T23:59:59.000Z

    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.

  11. Low temperature ion source for calutrons

    DOE Patents [OSTI]

    Veach, Allen M. (Oak Ridge, TN); Bell, Jr., William A. (Oak Ridge, TN); Howell, Jr., George D. (Clinton, TN)

    1981-01-01T23:59:59.000Z

    A new ion source assembly for calutrons has been provided for the efficient separation of elements having high vapor pressures. The strategic location of cooling pads and improved insulation permits operation of the source at lower temperatures. A vapor valve constructed of graphite and located in a constantly increasing temperature gradient provides reliable control of the vapor flow from the charge bottle to the arc chamber. A pronounced saving in calutron operating time and equipment maintenance has been achieved with the use of the present ion source.

  12. Sampling for Bacteria in Wells 

    E-Print Network [OSTI]

    Lesikar, Bruce J.

    2001-11-15T23:59:59.000Z

    Sampling for Bacteria in Wells E-126 11/01 Water samples for bacteria tests must always be col- lected in a sterile container. The procedure for collect- ing a water sample is as follows: 1. Obtain a sterile container from a Health Department... immediately after collecting water sample. Refrigerate the sample and transport it to the laborato- ry (in an ice chest) as soon after collection as possible (six hours is best, but up to 30 hours). Many labs will not accept bacteria samples on Friday so check...

  13. Well Deepening | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-fTri GlobalJump to: navigation,Goff, 2002) |Weedpatch,Welcome NewWell

  14. Production Wells | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal PwerPerkins County, Nebraska:Precourt Institute for EnergyWister|Production Wells (Redirected

  15. Observation Wells | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluatingGroup |JilinLuOpenNorth AmericaNorthwestOakdale Electric CoopWells Jump to:

  16. Detection of water or gas entry into horizontal wells by using permanent downhole monitoring systems

    E-Print Network [OSTI]

    Yoshioka, Keita

    2007-09-17T23:59:59.000Z

    distributed temperature sensors (DTS) in intelligent completions. Analyzing such changes will potentially aid the diagnosis of downhole flow conditions. In vertical wells, temperature logs have been used successfully to diagnose the downhole flow conditions...

  17. SOLPOND: a simulation program for salinity gradient solar ponds

    SciTech Connect (OSTI)

    Henderson, J.; Leboeuf, C.M.

    1980-01-01T23:59:59.000Z

    A computer simulation design tool was developed to simulate dynamic thermal performance for salinity gradient solar ponds. Dynamic programming techniques allow the user significant flexibility in analyzing pond performance under realistic load and weather conditions. Finite element techniques describe conduction heat transfer through the pond, earth, and edges. Results illustrate typical thermal performance of salinity gradient ponds. Sensitivity studies of salty pond thermal performance with respect to geometry, load, and optical transmission are included. Experimental validation of the program with an operating pond is also presented.

  18. Radial gradients and metallicities in the galactic disk

    E-Print Network [OSTI]

    W. J. Maciel

    2000-12-08T23:59:59.000Z

    Radial O/H abundance gradients derived from HII regions, hot stars and planetary nebulae are combined with [Fe/H] gradients from open cluster stars in order to derive an independent [O/Fe] x [Fe/H] relation for the galactic disk. A comparison of the obtained relation with recent observational data and theoretical models suggests that the [O/Fe] ratio is not higher than [O/Fe] ~ 0.4, at least within the metallicity range of the considered samples.

  19. Nonlinear elastic free energies and gradient Young-Gibbs measures

    E-Print Network [OSTI]

    Roman Kotecký; Stephan Luckhaus

    2012-06-26T23:59:59.000Z

    We investigate, in a fairly general setting, the limit of large volume equilibrium Gibbs measures for elasticity type Hamiltonians with clamped boundary conditions. The existence of a quasiconvex free energy, forming the large deviations rate functional, is shown using a new interpolation lemma for partition functions. The local behaviour of the Gibbs measures can be parametrized by Young measures on the space of gradient Gibbs measures. In view of unboundedness of the state space, the crucial tool here is an exponential tightness estimate that holds for a vast class of potentials and the construction of suitable compact sets of gradient Gibbs measures.

  20. On Higuchi Ghosts and Gradient Instabilities in Bimetric Gravity

    E-Print Network [OSTI]

    Könnig, Frank

    2015-01-01T23:59:59.000Z

    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.

  1. Gradient isolator for flow field of fuel cell assembly

    DOE Patents [OSTI]

    Ernst, William D. (Troy, NY)

    1999-01-01T23:59:59.000Z

    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.

  2. Velocity bunching in travelling wave accelerator with low acceleration gradient

    E-Print Network [OSTI]

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

    2013-01-01T23:59:59.000Z

    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.

  3. Discontinuous Galerkin finite element methods for gradient plasticity.

    SciTech Connect (OSTI)

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

    2010-10-01T23:59:59.000Z

    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.

  4. Gradients of meteorological parameters in convective and nonconvective areas

    E-Print Network [OSTI]

    McCown, Milton Samuel

    1976-01-01T23:59:59.000Z

    . 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...

  5. Gradient isolator for flow field of fuel cell assembly

    DOE Patents [OSTI]

    Ernst, W.D.

    1999-06-15T23:59:59.000Z

    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.

  6. Assessment of plasma impedance probe for measuring electron density and collision frequency in a plasma with spatial and temporal gradients

    SciTech Connect (OSTI)

    Hopkins, Mark A., E-mail: mahopkin@mtu.edu; King, Lyon B. [Mechanical Engineering-Engineering Mechanics, Michigan Technological University, 815 R. L. Smith BLDG, Houghton, Michigan 49930 (United States)] [Mechanical Engineering-Engineering Mechanics, Michigan Technological University, 815 R. L. Smith BLDG, Houghton, Michigan 49930 (United States)

    2014-05-15T23:59:59.000Z

    Numerical simulations and experimental measurements were combined to determine the ability of a plasma impedance probe (PIP) to measure plasma density and electron collision frequency in a plasma containing spatial gradients as well as time-varying oscillations in the plasma density. A PIP is sensitive to collision frequency through the width of the parallel resonance in the Re[Z]-vs.-frequency characteristic, while also being sensitive to electron density through the zero-crossing of the Im[Z]-vs.-frequency characteristic at parallel resonance. Simulations of the probe characteristic in a linear plasma gradient indicated that the broadening of Re[Z] due to the spatial gradient obscured the broadening due to electron collision frequency, preventing a quantitative measurement of the absolute collision frequency for gradients considered in this study. Simulation results also showed that the PIP is sensitive to relative changes in electron collision frequency in a spatial density gradient, but a second broadening effect due to time-varying oscillations made collision frequency measurements impossible. The time-varying oscillations had the effect of causing multiple zero-crossings in Im[Z] at parallel resonance. Results of experiments and simulations indicated that the lowest-frequency zero-crossing represented the lowest plasma density in the oscillations and the highest-frequency zero-crossing represented the highest plasma density in the oscillations, thus the PIP probe was found to be an effective tool to measure both the average plasma density as well as the maximum and minimum densities due to temporal oscillations.

  7. Geothermal well log interpretation state of the art. Final report

    SciTech Connect (OSTI)

    Sanyal, S.K.; Wells, L.E.; Bickham, R.E.

    1980-01-01T23:59:59.000Z

    An in-depth study of the state of the art in Geothermal Well Log Interpretation has been made encompassing case histories, technical papers, computerized literature searches, and actual processing of geothermal wells from New Mexico, Idaho, and California. A classification scheme of geothermal reservoir types was defined which distinguishes fluid phase and temperature, lithology, geologic province, pore geometry, salinity, and fluid chemistry. Major deficiencies of Geothermal Well Log Interpretation are defined and discussed with recommendations of possible solutions or research for solutions. The Geothermal Well Log Interpretation study and report has concentrated primarily on Western US reservoirs. Geopressured geothermal reservoirs are not considered.

  8. Ultra Thin Quantum Well Materials

    SciTech Connect (OSTI)

    Dr Saeid Ghamaty

    2012-08-16T23:59:59.000Z

    This project has enabled Hi-Z technology Inc. (Hi-Z) to understand how to improve the thermoelectric properties of Si/SiGe Quantum Well Thermoelectric Materials. The research that was completed under this project has enabled Hi-Z Technology, Inc. (Hi-Z) to satisfy the project goal to understand how to improve thermoelectric conversion efficiency and reduce costs by fabricating ultra thin Si/SiGe quantum well (QW) materials and measuring their properties. In addition, Hi-Z gained critical new understanding on how thin film fabrication increases the silicon substrate's electrical conductivity, which is important new knowledge to develop critical material fabrication parameters. QW materials are constructed with alternate layers of an electrical conductor, SiGe and an electrical insulator, Si. Film thicknesses were varied, ranging from 2nm to 10nm where 10 nm was the original film thickness prior to this work. The optimum performance was determined at a Si and SiGe thickness of 4nm for an electrical current and heat flow parallel to the films, which was an important conclusion of this work. Essential new information was obtained on how the Si substrate electrical conductivity increases by up to an order of magnitude upon deposition of QW films. Test measurements and calculations are accurate and include both the quantum well and the substrate. The large increase in substrate electrical conductivity means that a larger portion of the electrical current passes through the substrate. The silicon substrate's increased electrical conductivity is due to inherent impurities and thermal donors which are activated during both molecular beam epitaxy and sputtering deposition of QW materials. Hi-Z's forward looking cost estimations based on future high performance QW modules, in which the best Seebeck coefficient and electrical resistivity are taken from separate samples predict that the electricity cost produced with a QW module could be achieved at <$0.35/W. This price would open many markets for waste heat recovery applications. By installing Hi-Z's materials in applications in which electricity could be produced from waste heat sources could result in significant energy savings as well as emissions reductions. For example, if QW thermoelectric generators could be introduced commercially in 2015, and assuming they could also capture an additional 0.1%/year of the available waste heat from the aluminum, steel, and iron industries, then by 2020, their use would lead to a 2.53 trillion Btu/year reduction in energy consumption. This translates to a $12.9 million/year energy savings, and 383.6 million lb's of CO2 emissions reduction per year. Additionally, Hi-Z would expect that the use of QW TE devices in the automotive, manufacturing, and energy generation industries would reduce the USA's petroleum and fossil fuel dependence, and thus significantly reduce emissions from CO2 and other polluting gasses such as NOx, SOx, and particulate matter (PM), etc.

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

    SciTech Connect (OSTI)

    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

    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.

  10. Low-to-moderate temperature geothermal resource assessment for Nevada, area specific studies. Final report, June 1, 1980-August 30, 1981

    SciTech Connect (OSTI)

    Trexler, D.T.; Koenig, B.A.; Flynn, T.; Bruce, J.L.; Ghusn, G. Jr.

    1981-01-01T23:59:59.000Z

    The Hawthorne study area is located in Mineral County, Nevada and surrounds the municipality of the same name. It encompasses an area of approximately 310 sq. km (120 sq. mi), and most of the land belongs to the US Army Ammunition Plant. The energy needs of the military combined with those of the area population (over 5,000 residents) are substantial. The area is classified as having a high potential for direct applications using the evaluation scheme described in Texler and others (1979). A variety of scientific techniques was employed during area-wide resource assessment. General geologic studies demonstrate the lithologic diversity in the area; these studies also indicate possible sources for dissolved fluid constituents. Geophysical investigations include aero-magnetic and gravity surveys which aid in defining the nature of regional, and to a lesser extent, local variations in subsurface configurations. Surface and near-surface structural features are determined using various types of photo imagery including low sun-angle photography. An extensive shallow depth temperature probe survey indicates two zones of elevated temperature on opposite sides of the Walker Lake basin. Temperature-depth profiles from several wells in the study area indicate significant thermal fluid-bearing aquifers. Fluid chemical studies suggest a wide spatial distribution for the resource, and also suggest a meteoric recharge source in the Wassuk Range. Finally, a soil-mercury survey was not a useful technique in this study area. Two test holes were drilled to conclude the area resource assessment, and thermal fluids were encountered in both wells. The western well has measured temperatures as high as 90 C (194 F) within 150 meters (500 ft) of the surface. Temperature profiles in this well indicate a negative temperature gradient below 180 meters (590 ft). The eastern hole had a bottom hole temperature of 61 C (142 F) at a depth of only 120 meters (395 ft). A positive gradient is observed to a total depth in the well. Several conclusions are drawn from this study: the resource is distributed over a relatively large area; resource fluid temperatures can exceed 90 C (194 F), but are probably limited to a maximum of 125 C (257 F); recharge to the thermal system is meteoric, and flow of the fluids in the near surface (< 500 m) is not controlled by faults; heat supplied to the system may be related to a zone of partially melted crustal rocks in the area 25 km (15 mi) south of Hawthorne. Four papers and an introduction are included. A separate abstract was prepared for each paper. (MHR)

  11. Geothermal Energy Production from Low Temperature Resources,...

    Open Energy Info (EERE)

    Production from Low Temperature Resources, Coproduced Fluids from Oil and Gas Wells, and Geopressured Resources Jump to: navigation, search Geothermal ARRA Funded Projects for...

  12. Estimating Temperature Distributions In Geothermal Areas Using...

    Open Energy Info (EERE)

    an analytical model, showing that the errors in neuronet temperature estimates based on well log data derive from: (a) the neuronet "education level" (which depends on the amount...

  13. Spatially indirect excitons in coupled quantum wells

    SciTech Connect (OSTI)

    Lai, Chih-Wei Eddy

    2004-03-01T23:59:59.000Z

    Microscopic quantum phenomena such as interference or phase coherence between different quantum states are rarely manifest in macroscopic systems due to a lack of significant correlation between different states. An exciton system is one candidate for observation of possible quantum collective effects. In the dilute limit, excitons in semiconductors behave as bosons and are expected to undergo Bose-Einstein condensation (BEC) at a temperature several orders of magnitude higher than for atomic BEC because of their light mass. Furthermore, well-developed modern semiconductor technologies offer flexible manipulations of an exciton system. Realization of BEC in solid-state systems can thus provide new opportunities for macroscopic quantum coherence research. In semiconductor coupled quantum wells (CQW) under across-well static electric field, excitons exist as separately confined electron-hole pairs. These spatially indirect excitons exhibit a radiative recombination time much longer than their thermal relaxation time a unique feature in direct band gap semiconductor based structures. Their mutual repulsive dipole interaction further stabilizes the exciton system at low temperature and screens in-plane disorder more effectively. All these features make indirect excitons in CQW a promising system to search for quantum collective effects. Properties of indirect excitons in CQW have been analyzed and investigated extensively. The experimental results based on time-integrated or time-resolved spatially-resolved photoluminescence (PL) spectroscopy and imaging are reported in two categories. (i) Generic indirect exciton systems: general properties of indirect excitons such as the dependence of exciton energy and lifetime on electric fields and densities were examined. (ii) Quasi-two-dimensional confined exciton systems: highly statistically degenerate exciton systems containing more than tens of thousands of excitons within areas as small as (10 micrometer){sup 2} were observed. The spatial and energy distributions of optically active excitons were used as thermodynamic quantities to construct a phase diagram of the exciton system, demonstrating the existence of distinct phases. Optical and electrical properties of the CQW sample were examined thoroughly to provide deeper understanding of the formation mechanisms of these cold exciton systems. These insights offer new strategies for producing cold exciton systems, which may lead to opportunities for the realization of BEC in solid-state systems.

  14. Fluid-Rock Characterization and Interactions in NMR Well Logging

    SciTech Connect (OSTI)

    George J. Hirasaki; Kishore K. Mohanty

    2005-09-05T23:59:59.000Z

    The objective of this report is to characterize the fluid properties and fluid-rock interactions that are needed for formation evaluation by NMR well logging. The advances made in the understanding of NMR fluid properties are summarized in a chapter written for an AAPG book on NMR well logging. This includes live oils, viscous oils, natural gas mixtures, and the relation between relaxation time and diffusivity. Oil based drilling fluids can have an adverse effect on NMR well logging if it alters the wettability of the formation. The effect of various surfactants on wettability and surface relaxivity are evaluated for silica sand. The relation between the relaxation time and diffusivity distinguishes the response of brine, oil, and gas in a NMR well log. A new NMR pulse sequence in the presence of a field gradient and a new inversion technique enables the T{sub 2} and diffusivity distributions to be displayed as a two-dimensional map. The objectives of pore morphology and rock characterization are to identify vug connectivity by using X-ray CT scan, and to improve NMR permeability correlation. Improved estimation of permeability from NMR response is possible by using estimated tortuosity as a parameter to interpolate between two existing permeability models.

  15. EA-1758: Final Environmental Assessment

    Broader source: Energy.gov [DOE]

    Drilling, Testing, and Monitoring of up to 12 Temperature Gradient/Passive Seismic Geothermal Exploratory Wells

  16. NON-STATIONARY TEMPERATURE STRESSES IN THE INDUSTRIAL STEAM TURBINE ROTOR

    E-Print Network [OSTI]

    Zvonimir Guzovi?; Krešimir Kova?i?; Tihomir Mihali?

    The usage of industrial steam turbines in different industrial branches (chemistry, petrochemistry, refineries, sugar and ethanol plants, etc.) for a generator drive for electricity generation or a mechanical drive for compressors, blowers and pumps, is characterized by the need for high flexibility of operation. High flexibility includes numerous start-ups, shut-downs and power changes during the useful life. Changes in power and steam mass flow lead to changes of the working fluid state in the single turbine stages, and thus their aerodynamic and thermodynamic characteristics. During these transient working regimes in steam turbine rotors, large space and time-dependent temperature gradients appear, which can result in high non-stationary temperature stresses, i.e. increased local stress concentrations, what has a negative impact on the useful life of the rotor. In the worst case they can cause fracture of the turbine rotor. Today, for the determination of thermal stressed state of the steam turbine parts the user softwares based on numerical methods are used. In this paper the results of numerical modelling and calculations of non-stationary temperature fields and related stresses in the rotor of industrial steam turbine of 35 MW power during transient operating regime (a cold startup) will be presented. The results of the calculations serve for estimation of the transient regime impact on the stresses of the rotor, as well as on its entire useful life. Key words: industrial steam turbine, transient regimes, temperature stresses, numerical modelling 1.

  17. A strong polynomial gradient algorithm in Linear Programming

    E-Print Network [OSTI]

    peter bruijs

    2015-03-31T23:59:59.000Z

    Page 1 ... Karmarkar don't have the strong characteristic. ... Probably he had no notion of the concept of a convex space, so that is what will have to be .... For the best direction that is left now, one has to exclude from the gradient c exactly and.

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

    E-Print Network [OSTI]

    Rasmussen, L.A.

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

  19. 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

  20. Gradient expansion of superhorizon perturbations in G-inflation

    SciTech Connect (OSTI)

    Frusciante, Noemi; Zhou, Shuang-Yong; Sotiriou, Thomas P., E-mail: nfruscia@sissa.it, E-mail: szhou@sissa.it, E-mail: sotiriou@sissa.it [SISSA and INFN Sezione di Trieste, Via Bonomea 265, 34136, Trieste (Italy)

    2013-07-01T23:59:59.000Z

    We develop the gradient expansion formalism for shift-symmetric Galileon-type actions. We focus on backgrounds that undergo inflation, work in the synchronous gauge, and obtain a general solution up to second order without imposing extra conditions at first order. The solution simplifies during the late stages of inflation. We also define a curvature perturbation conserved up to first order.

  1. Continuous Edge Gradient-Based Template Matching for Articulated

    E-Print Network [OSTI]

    Zachmann, Gabriel

    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

  2. Computing several eigenpairs of Hermitian problems by conjugate gradient iterations

    SciTech Connect (OSTI)

    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

    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.

  3. BIOGEOCHEMICAL GRADIENTS AS A FRAMEWORK FOR UNDERSTANDING WASTE SITE EVOLUTION

    SciTech Connect (OSTI)

    Denham, M; Karen Vangelas, K

    2008-10-17T23:59:59.000Z

    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.

  4. Soil macroaggregate dynamics in a mountain spatial climate gradient

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    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

  5. Gradient Improvement by Removal of Identified Local Defects

    SciTech Connect (OSTI)

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

    2011-07-01T23:59:59.000Z

    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.

  6. Overfitting in Neural Nets: Backpropagation, Conjugate Gradient, and Early Stopping

    E-Print Network [OSTI]

    Caruana, Rich

    Overfitting in Neural Nets: Backpropagation, Conjugate Gradient, and Early Stopping Rich Caruana is that backprop nets with excess hidden units generalize poorly. We show that nets with excess capacity generalize) Regardless of size, nets learn task subcomponents in similar sequence. Big nets pass through stages similar

  7. SUBMIT TO IEEE TIP 1 Motion-Aware Gradient Domain

    E-Print Network [OSTI]

    O'Brien, James F.

    SUBMIT TO IEEE TIP 1 Motion-Aware Gradient Domain Video Composition Tao Chen, Jun-Yan Zhu, Ariel blending boundary based on a user provided blending trimap for the source video. Our approach extends mean performance. We also provide a user interface and source object positioning method that can efficiently deal

  8. A distributed accelerated gradient algorithm for distributed model predictive

    E-Print Network [OSTI]

    Como, Giacomo

    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

  9. A study of microbend test by strain gradient plasticity

    E-Print Network [OSTI]

    Hsia, K Jimmy

    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

  10. Treated Wastewater Effluent Reduces Sperm Motility Along an Osmolality Gradient

    E-Print Network [OSTI]

    Julius, Matthew L.

    of the Metropolitan Wastewater Treatment Plant, St. Paul, Minnesota, and from an upstream site on the MississippiTreated Wastewater Effluent Reduces Sperm Motility Along an Osmolality Gradient H. L. Schoenfuss Ć 2008 Ó Springer Science+Business Media, LLC 2008 Abstract Many toxic effects of treated wastewater

  11. Thermal gradient-induced forces on geodetic reference masses for LISA

    E-Print Network [OSTI]

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

    2007-06-29T23:59:59.000Z

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

  12. Experimental Observation of the Inverse Spin Hall Effect at Room Temperature

    SciTech Connect (OSTI)

    Liu, Baoli; Shi, Junren; Wang, Wenxin; Zhao, Hongming; Li, Dafang; /Beijing, Inst. Phys.; Zhang, Shoucheng; /Stanford U., Phys. Dept.; Xue, Qikun; Chen, Dongmin; /Beijing, Inst. Phys.

    2010-03-16T23:59:59.000Z

    We observe the inverse spin Hall effect in a two-dimensional electron gas confined in Al-GaAs/InGaAs quantum wells. Specifically, they find that an inhomogeneous spin density induced by the optical injection gives rise to an electric current transverse to both the spin polarization and its gradient. The spin Hall conductivity can be inferred from such a measurement through the Einstein relation and the onsager relation, and is found to have the order of magnitude of 0.5(e{sup 2}/h). The observation is made at the room temperature and in samples with macroscopic sizes, suggesting that the inverse spin Hall effects is a robust macroscopic transport phenomenon.

  13. INVITATIONAL WELL-TESTING SYMPOSIUM PROCEEDINGS

    E-Print Network [OSTI]

    Authors, Various

    2011-01-01T23:59:59.000Z

    Technology and Needs for Drilling and Well Testing. . . . .AND NEEDS FOR DRILLING AND WELL TESTING INSTRUMENTATIONand Needs for Drilling and Well Testing Instrumentation W.

  14. INVITATIONAL WELL-TESTING SYMPOSIUM PROCEEDINGS

    E-Print Network [OSTI]

    Authors, Various

    2011-01-01T23:59:59.000Z

    Education Course on Well Completion and Stimulation, Feb.to provide a reasonable well completion opportunity. Duringinterpretation and well completion strategy. In addition, a

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

    SciTech Connect (OSTI)

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

    1983-01-01T23:59:59.000Z

    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.

  16. Chemical analyses of selected thermal springs and wells in Wyoming

    SciTech Connect (OSTI)

    Heasler, H.P.

    1984-06-01T23:59:59.000Z

    Basic chemical data for 27 selected thermal well and springs in Wyoming are presented. The samples were gathered from 1979 through 1982 in an effort to define geothermal resources in Wyoming. The basic data for the 27 analyzed samples generally include location, temperature, flow, date analyzed, and a description of what the sample is from. The chemical analyses for the sample are listed.

  17. Production Well Performance Enhancement using Sonication Technology

    SciTech Connect (OSTI)

    Adewumi, Michael A; Ityokumbul, M Thaddeus; Watson, Robert W; Eltohami, Eltohami; Farias, Mario; Heckman, Glenn; Houlihan, Brendan; Karoor, Samata Prakash; Miller, Bruce G; Mohammed, Nazia; Olanrewaju, Johnson; Ozdemir, Mine; Rejepov, Dautmamed; Sadegh, Abdallah A; Quammie, Kevin E; Zaghloul, Jose; Hughes, W Jack; Montgomery, Thomas C

    2005-12-31T23:59:59.000Z

    The objective of this project was to develop a sonic well performance enhancement technology that focused on near wellbore formation damage. In order to successfully achieve this objective, a three-year project was defined. The entire project was broken into four tasks. The overall objective of all this was to foster a better understanding of the mechanisms involved in sonic energy interactions with fluid flow in porous media and adapt such knowledge for field applications. The fours tasks are: • Laboratory studies • Mathematical modeling • Sonic tool design and development • Field demonstration The project was designed to be completed in three years; however, due to budget cuts, support was only provided for the first year, and hence the full objective of the project could not be accomplished. This report summarizes what was accomplished with the support provided by the US Department of Energy. Experiments performed focused on determining the inception of cavitation, studying thermal dissipation under cavitation conditions, investigating sonic energy interactions with glass beads and oil, and studying the effects of sonication on crude oil properties. Our findings show that the voltage threshold for onset of cavitation is independent of transducer-hydrophone separation distance. In addition, thermal dissipation under cavitation conditions contributed to the mobilization of deposited paraffins and waxes. Our preliminary laboratory experiments suggest that waxes are mobilized when the fluid temperature approaches 40°C. Experiments were conducted that provided insights into the interactions between sonic wave and the fluid contained in the porous media. Most of these studies were carried out in a slim-tube apparatus. A numerical model was developed for simulating the effect of sonication in the nearwellbore region. The numerical model developed was validated using a number of standard testbed problems. However, actual application of the model for scale-up purposes was limited due to funding constraints. The overall plan for this task was to perlorm field trials with the sonication tooL These trials were to be performed in production and/or injection wells located in Pennsylvania, New York, and West Virginia. Four new wells were drilled in preparation for the field demonstration. Baseline production data were collected and reservoir simulator tuned to simulate these oil reservoirs. The sonication tools were designed for these wells. However, actual field testing could not be carried out because of premature termination of the project.

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

    SciTech Connect (OSTI)

    Geng, Rongli [JLAB

    2009-11-01T23:59:59.000Z

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

  19. Diffusion-assisted selective dynamical recoupling: A new approach to measure background gradients in magnetic resonance

    SciTech Connect (OSTI)

    Álvarez, Gonzalo A.; Shemesh, Noam; Frydman, Lucio, E-mail: lucio.frydman@weizmann.ac.il [Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100 (Israel)] [Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100 (Israel)

    2014-02-28T23:59:59.000Z

    Dynamical decoupling, a generalization of the original NMR spin-echo sequence, is becoming increasingly relevant as a tool for reducing decoherence in quantum systems. Such sequences apply non-equidistant refocusing pulses for optimizing the coupling between systems, and environmental fluctuations characterized by a given noise spectrum. One such sequence, dubbed Selective Dynamical Recoupling (SDR) [P. E. S. Smith, G. Bensky, G. A. Álvarez, G. Kurizki, and L. Frydman, Proc. Natl. Acad. Sci. 109, 5958 (2012)], allows one to coherently reintroduce diffusion decoherence effects driven by fluctuations arising from restricted molecular diffusion [G. A. Álvarez, N. Shemesh, and L. Frydman, Phys. Rev. Lett. 111, 080404 (2013)]. The fully-refocused, constant-time, and constant-number-of-pulses nature of SDR also allows one to filter out “intrinsic” T{sub 1} and T{sub 2} weightings, as well as pulse errors acting as additional sources of decoherence. This article explores such features when the fluctuations are now driven by unrestricted molecular diffusion. In particular, we show that diffusion-driven SDR can be exploited to investigate the decoherence arising from the frequency fluctuations imposed by internal gradients. As a result, SDR presents a unique way of probing and characterizing these internal magnetic fields, given an a priori known free diffusion coefficient. This has important implications in studies of structured systems, including porous media and live tissues, where the internal gradients may serve as fingerprints for the system's composition or structure. The principles of this method, along with full analytical solutions for the unrestricted diffusion-driven modulation of the SDR signal, are presented. The potential of this approach is demonstrated with the generation of a novel source of MRI contrast, based on the background gradients active in an ex vivo mouse brain. Additional features and limitations of this new method are discussed.

  20. Electron temperature fluctuations in NGC 346

    E-Print Network [OSTI]

    V. A. Oliveira; M. V. F. Copetti; A. C. Krabbe

    2008-10-28T23:59:59.000Z

    The existence and origin of large spatial temperature fluctuations in HII regions and planetary nebulae are assumed to explain the differences between the heavy element abundances inferred from collisionally excited and recombination lines, although this interpretation remains significantly controversial. We investigate the spatial variation in electron temperature inside NGC 346, the brightest HII region in the Small Magellanic Cloud. Long slit spectrophotometric data of high signal-to-noise were employed to derive the electron temperature from measurements derived from localized observations of the [OIII]($\\lambda4959 + \\lambda5007)/\\lambda4363$ ratio in three directions across the nebula. The electron temperature was estimated in 179 areas of 5$^{\\prime\\prime}\\times1.5^{\\prime\\prime}$ of size distributed along three different declinations. A largely homogeneous temperature distribution was found with a mean temperature of 12 269 K and a dispersion of 6.1%. After correcting for pure measurements errors, a temperature fluctuation on the plane of the sky of $t^2_{\\rm s} = 0.0021$ (corresponding to a dispersion of 4.5%) was obtained, which indicates a 3D temperature fluctuation parameter of $t^2 \\approx 0.008$. A large scale gradient in temperature of the order of $-5.7\\pm1.3$ K arcsec$^{-1}$ was found. The magnitude of the temperature fluctuations observed agrees with the large scale variations in temperature predicted by standard photoionization models, but is too small to explain the abundance discrepancy problem. However, the possible existence of small spatial scale temperature variations is not excluded.

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

    E-Print Network [OSTI]

    Vidula, Mahesh K.

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

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

    E-Print Network [OSTI]

    Brewer, Carol

    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

  3. INDUSTRIAL AND SYSTEMS ENGINEERING SEMINAR Semi-Stochastic Gradient Descent Methods

    E-Print Network [OSTI]

    Edinburgh, University of

    () of smooth convex loss functions. We propose a new method, S2GD (Semi-StochasticGradient Descent), which runs equivalent to the computation of a single gradient of the loss, is (log(1 / )). This is achieved by running

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

    DOE Patents [OSTI]

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

    1995-01-01T23:59:59.000Z

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

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

    DOE Patents [OSTI]

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

    1995-01-17T23:59:59.000Z

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

  6. Shading curves: vector-based drawing with explicit gradient control

    E-Print Network [OSTI]

    Lieng, Henrik; Tasse, Flora; Kosinka, Ji?í; Dodgson, Neil A.

    2015-01-01T23:59:59.000Z

    gradient. We resolve this problem by using subdivision surfaces that are constructed from shading curves and their shading profiles. Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Picture/Image Gene- ration... potential sources of visual artefacts in Illustrator’s tool: the rendering procedure, the deformation procedure, and blending with underlying layers. Figure 18 shows images coloured with Illustrator’s tool, where arte- facts are visible. In comparison, our...

  7. Gradient instabilities of electromagnetic waves in Hall thruster plasma

    SciTech Connect (OSTI)

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

    2013-04-15T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Hoover, Caroline Marie

    1985-01-01T23:59:59.000Z

    of H drolo can be valuable predictive tool s (Wang and Anderson, 1982). Since the late 1800's, mathematical models have been used in problems of groundwater flow. Their appl ication now extends to problems of contaminant transport and migration...DETERMINATION OF DISPERSIVITIES FROM A NATURAL-GRADIENT DISPERSION TEST A Thesis by CAROLINE MARIE HOOVER Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirements for the degree of MASTER...

  9. The Old Halo metallicity gradient: the trace of a self-enrichment process

    E-Print Network [OSTI]

    G. Parmentier; E. Jehin; P. Magain; A. Noels; A. Thoul

    2000-09-29T23:59:59.000Z

    Based on a model of globular cluster self-enrichment published in a previous paper, we present an explanation for the metallicity gradient observed throughout the galactic Old Halo. Our self-enrichment model is based on the ability of globular cluster progenitor clouds to retain the ejecta of a first generation of Type II Supernovae. The key point is that this ability depends on the pressure exerted on the progenitor cloud by the surrounding protogalactic medium and therefore on the location of the cloud in the protoGalaxy. Since there is no significant (if any) metallicity gradient in the whole halo, we also present a review in favour of a galactic halo partly build via accretions and mergers of satellite systems. Some of them bear their own globular clusters and therefore ``contaminate'' the system of globular clusters formed ``in situ'', namely within the original potential well of the Galaxy. Therefore, the comparison between our self-enrichment model and the observational data should be limited to the genuine galactic globular clusters, the so-called Old Halo group.

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

    E-Print Network [OSTI]

    A. Bershadskii

    2006-11-16T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

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

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

    E-Print Network [OSTI]

    Popel, Aleksander S.

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

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

    E-Print Network [OSTI]

    Mihajlovic, Milan D.

    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

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

    E-Print Network [OSTI]

    Knyazev, Andrew

    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

  15. 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

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

    E-Print Network [OSTI]

    Haynes, Peter

    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

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

    E-Print Network [OSTI]

    Kumar, Vipin

    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

  18. 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

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

    E-Print Network [OSTI]

    Gobbert, Matthias K.

    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

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

    E-Print Network [OSTI]

    Heuer, Norbert

    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

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

    E-Print Network [OSTI]

    Yuan, Ya-xiang

    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

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

    E-Print Network [OSTI]

    Hoffmann, Walter

    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

  3. A fast GPU Implementation of the Deflated Preconditioned Conjugate Gradient method

    E-Print Network [OSTI]

    Boyer, Edmond

    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

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

    E-Print Network [OSTI]

    Holst, Michael J.

    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

  5. 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

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

    E-Print Network [OSTI]

    Yuan, Ya-xiang

    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

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

    E-Print Network [OSTI]

    Hall, Julian

    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

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

    E-Print Network [OSTI]

    Nocedal, Jorge

    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

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

    E-Print Network [OSTI]

    Forsgren, Anders

    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

  10. 3D Shape from Silhouette Points in Registered 2D Images Using Conjugate Gradient Method

    E-Print Network [OSTI]

    Hoff, William A.

    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

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

    E-Print Network [OSTI]

    Nocedal, Jorge

    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

  12. PRECONDITIONED CONJUGATE GRADIENT METHODS FOR THE INCOMPRESSIBLE NAVIER-STOKES EQUATIONS

    E-Print Network [OSTI]

    Waterloo, University of

    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

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

    E-Print Network [OSTI]

    Navon, Michael

    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

  14. A MULTI-PRECONDITIONED CONJUGATE GRADIENT ROBERT BRIDSON AND CHEN GREIF

    E-Print Network [OSTI]

    Bridson, Robert

    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

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

    E-Print Network [OSTI]

    Zhang, Hongchao

    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

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

    E-Print Network [OSTI]

    Forsgren, Anders

    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

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

    E-Print Network [OSTI]

    Lyakhovsky, Vladimir

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

  18. Health and Wellness Guide for Students Introduction

    E-Print Network [OSTI]

    dimensions of health and wellness. The 7 dimensions are: Physical Wellness ­ Taking care of your body Wellness ­ Taking care of what's around you 2Health andWellness Guide for Students #12;Physical Wellness · Communicate with your partner if you have questions or concerns · Meet with a Health Care Provider on campus

  19. IMPROVED NATURAL GAS STORAGE WELL REMEDIATION

    SciTech Connect (OSTI)

    James C. Furness; Donald O. Johnson; Michael L. Wilkey; Lynn Furness; Keith Vanderlee; P. David Paulsen

    2001-12-01T23:59:59.000Z

    This report summarizes the research conducted during Budget Period One on the project ''Improved Natural Gas Storage Well Remediation''. The project team consisted of Furness-Newburge, Inc., the technology developer; TechSavants, Inc., the technology validator; and Nicor Technologies, Inc., the technology user. The overall objectives for the project were: (1) To develop, fabricate and test prototype laboratory devices using sonication and underwater plasma to remove scale from natural gas storage well piping and perforations; (2) To modify the laboratory devices into units capable of being used downhole; (3) To test the capability of the downhole units to remove scale in an observation well at a natural gas storage field; (4) To modify (if necessary) and field harden the units and then test the units in two pressurized injection/withdrawal gas storage wells; and (5) To prepare the project's final report. This report covers activities addressing objectives 1-3. Prototype laboratory units were developed, fabricated, and tested. Laboratory testing of the sonication technology indicated that low-frequency sonication was more effective than high-frequency (ultrasonication) at removing scale and rust from pipe sections and tubing. Use of a finned horn instead of a smooth horn improves energy dispersal and increases the efficiency of removal. The chemical data confirmed that rust and scale were removed from the pipe. The sonication technology showed significant potential and technical maturity to warrant a field test. The underwater plasma technology showed a potential for more effective scale and rust removal than the sonication technology. Chemical data from these tests also confirmed the removal of rust and scale from pipe sections and tubing. Focusing of the underwater plasma's energy field through the design and fabrication of a parabolic shield will increase the technology's efficiency. Power delivered to the underwater plasma unit by a sparkplug repeatedly was interrupted by sparkplug failure. The lifecycle for the plugs was less than 10 hours. An electrode feed system for delivering continuous power needs to be designed and developed. As a result, further work on the underwater plasma technology was terminated. It needs development of a new sparking system and a redesign of the pulsed power supply system to enable the unit to operate within a well diameter of less than three inches. Both of these needs were beyond the scope of the project. Meanwhile, the laboratory sonication unit was waterproofed and hardened, enabling the unit to be used as a field prototype, operating at temperatures to 350 F and depths of 15,000 feet. The field prototype was extensively tested at a field service company's test facility before taking it to the field site. The field test was run in August 2001 in a Nicor Gas storage field observation well at Pontiac, Illinois. Segmented bond logs, gamma ray neutron logs, water level measurements and water chemistry samples were obtained before and after the downhole demonstration. Fifteen tests were completed in the field. Results from the water chemistry analysis showed an increase in the range of calcium from 1755-1984 mg/l before testing to 3400-4028 mg/l after testing. For magnesium, the range increased from 285-296 mg/l to 461-480 mg/l. The change in pH from a range of 3.11-3.25 to 8.23-8.45 indicated a buffering of the acidic well water, probably due to the increased calcium available for buffering. The segmented bond logs showed no damage to the cement bond in the well and the gamma ray neutron log showed no increase in the amount of hydrocarbons present in the formation where the testing took place. Thus, the gas storage bubble in the aquifer was not compromised. A review of all the field test data collected documents the fact that the application of low-frequency sonication technology definitely removes scale from well pipe. Phase One of this project took sonication technology from the concept stage through a successful ''proof-of-concept'' downhole application in a natural gas storage field

  20. Multi-temperature representation of electron velocity distribution functions. I. Fits to numerical results

    SciTech Connect (OSTI)

    Haji Abolhassani, A. A.; Matte, J.-P. [INRS-Energie, Materiaux et Telecommunications, Universite du Quebec, Varennes, Quebec J3X 1S2 (Canada)

    2012-10-15T23:59:59.000Z

    Electron energy distribution functions are expressed as a sum of 6-12 Maxwellians or a sum of 3, but each multiplied by a finite series of generalized Laguerre polynomials. We fitted several distribution functions obtained from the finite difference Fokker-Planck code 'FPI'[Matte and Virmont, Phys. Rev. Lett. 49, 1936 (1982)] to these forms, by matching the moments, and showed that they can represent very well the coexistence of hot and cold populations, with a temperature ratio as high as 1000. This was performed for two types of problems: (1) the collisional relaxation of a minority hot component in a uniform plasma and (2) electron heat flow down steep temperature gradients, from a hot to a much colder plasma. We find that the multi-Maxwellian representation is particularly good if we accept complex temperatures and coefficients, and it is always better than the representation with generalized Laguerre polynomials for an equal number of moments. For the electron heat flow problem, the method was modified to also fit the first order anisotropy f{sub 1}(x,v,t), again with excellent results. We conclude that this multi-Maxwellian representation can provide a viable alternative to the finite difference speed or energy grid in kinetic codes.

  1. Deep Geothermal Reservoir Temperatures in the Eastern Snake River Plain, Idaho using Multicomponent Geothermometry

    SciTech Connect (OSTI)

    Ghanashyam Neupane; Earl D. Mattson; Travis L. McLing; Carl D. Palmer; Robert W. Smith; Thomas R. Wood

    2014-02-01T23:59:59.000Z

    The U.S. Geological survey has estimated that there are up to 4,900 MWe of undiscovered geothermal resources and 92,000 MWe of enhanced geothermal potential within the state of Idaho. Of particular interest are the resources of the Eastern Snake River Plain (ESRP) which was formed by volcanic activity associated with the relative movement of the Yellowstone Hot Spot across the state of Idaho. This region is characterized by a high geothermal gradient and thermal springs occurring along the margins of the ESRP. Masking much of the deep thermal potential of the ESRP is a regionally extensive and productive cold-water aquifer. We have undertaken a study to infer the temperature of the geothermal system hidden beneath the cold-water aquifer of the ESRP. Our approach is to estimate reservoir temperatures from measured water compositions using an inverse modeling technique (RTEst) that calculates the temperature at which multiple minerals are simultaneously at equilibrium while explicitly accounting for the possible loss of volatile constituents (e.g., CO2), boiling and/or water mixing. In the initial stages of this study, we apply the RTEst model to water compositions measured from a limited number of wells and thermal springs to estimate the regionally extensive geothermal system in the ESRP.

  2. 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

  3. Oil and Gas Wells: Regulatory Provisions (Kansas)

    Broader source: Energy.gov [DOE]

    It shall be unlawful for any person, firm or corporation having possession or control of any natural gas well, oil well or coalbed natural gas well, whether as a contractor, owner, lessee, agent or...

  4. Industry survey for horizontal wells. Final report

    SciTech Connect (OSTI)

    Wilson, D.D.; Kaback, D.S. [CDM Federal Programs Corp., Denver, CO (United States); Denhan, M.E. [Westinghouse Savannah River Co., Aiken, SC (United States); Watkins, D. [CDM Federal Programs Corp., Aiken, SC (United States)

    1993-07-01T23:59:59.000Z

    An international survey of horizontal environmental wells was performed during May and June of 1993. The purpose of the survey was to provide the environmental industry with an inventory of horizontal environmental wells and information pertaining to the extent of the use of horizontal environmental wells, the variety of horizontal environmental well applications, the types of geologic and hydrogeologic conditions within which horizontal environmental wells have been installed, and the companies that perform horizontal environmental well installations. Other information, such as the cost of horizontal environmental well installations and the results of tests performed on the wells, is not complete but is provided as general information with the caveat that the information should not be used to compare drilling companies. The result of the survey is a catalogue of horizontal environmental wells that are categorized by the objective or use of the wells, the vertical depth of the wells, and the drilling company contracted to install the wells.

  5. New multilateral well architecture in heterogeneous reservoirs

    E-Print Network [OSTI]

    Jia, Hongqiao

    2004-09-30T23:59:59.000Z

    . The performance of new multilateral well in heterogeneous reservoirs is studied, and that is compared with vertical well architecture also. In order to study the productivity of new multilateral wells, we use a numerical simulation method to set up heterogeneous...

  6. Fluid-Rock Characterization and Interactions in NMR Well Logging

    SciTech Connect (OSTI)

    Hirasaki, George J.; Mohanty, Kishore, K.

    2001-07-13T23:59:59.000Z

    The objective of this project is to characterize the fluid properties and fluid-rock interactions that are needed for formation evaluation by NMR well logging. This is the first annual progress report submitted to the DOE. It reports on the work completed during the reporting period even if it may have started before this period. This project is a partnership between Professor George J. Hirasaki at Rice University and Professor Kishore Mohanty at University of Houston. In addition to the DOE, this project is supported by a consortium of oil companies and service companies. The fluid properties characterization has emphasized the departure of live oils from correlations based on dead oils. Also, asphaltic components can result in a difference between the T1 and T2 relaxation time distributions as well as reduce the hydrogen index. The fluid rock characterizations that are reported here are the effects of wettability and internal magnetic field gradients. A pore reconstruction method ha s been developed to recreate three-dimensional porous media from two-dimensional images that reproduce some of their key statistical properties. A Monte Carlo simulation technique has been developed to calculate the magnetization decay in fluid saturated porous media given their pore structure.

  7. Functionalized Graphene Nanoroads for Quantum Well Device. |...

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

    Nanoroads for Quantum Well Device. Functionalized Graphene Nanoroads for Quantum Well Device. Abstract: Using density functional theory, a series of calculations of structural and...

  8. Nanoparticle characterization by continuous contrast variation in SAXS with a solvent density gradient

    E-Print Network [OSTI]

    Raul Garcia-Diez; Christian Gollwitzer; Michael Krumrey

    2014-10-27T23:59:59.000Z

    Many low-density nanoparticles show a radial inner structure. This work proposes a novel approach to contrast variation with SAXS based on the constitution of a solvent density gradient in a glass capillary in order to resolve this internal morphology. Scattering curves of a polymeric core-shell colloid were recorded at different suspending medium contrasts at the four-crystal monochromator beamline of PTB at the synchrotron radiation facility BESSY II. The mean size and size distribution of the particles as well as an insight into the colloid electron density composition were determined using the position of the isoscattering points in the Fourier region of the scattering curves and by examining the Guinier region in detail. These results were corroborated with a model fit to the experimental data, which provided complementary information about the inner electron density distribution of the suspended nanoparticles.

  9. Helicopter magnetic survey conducted to locate wells

    SciTech Connect (OSTI)

    Veloski, G.A.; Hammack, R.W.; Stamp, V. (Rocky Mountain Oilfield Testing Center); Hall, R. (Rocky Mountain Oilfield Testing Center); Colina, K. (Rocky Mountain Oilfield Testing Center)

    2008-07-01T23:59:59.000Z

    A helicopter magnetic survey was conducted in August 2007 over 15.6 sq mi at the Naval Petroleum Reserve No. 3’s (NPR-3) Teapot Dome Field near Casper, Wyoming. The survey’s purpose was to accurately locate wells drilled there during more than 90 years of continuous oilfield operation. The survey was conducted at low altitude and with closely spaced flight lines to improve the detection of wells with weak magnetic response and to increase the resolution of closely spaced wells. The survey was in preparation for a planned CO2 flood for EOR, which requires a complete well inventory with accurate locations for all existing wells. The magnetic survey was intended to locate wells missing from the well database and to provide accurate locations for all wells. The ability of the helicopter magnetic survey to accurately locate wells was accomplished by comparing airborne well picks with well locations from an intense ground search of a small test area.

  10. Auger recombination in quantum-well InGaAsP heterostructure lasers

    SciTech Connect (OSTI)

    Chiu, L.C.; Yariv, A.

    1982-10-01T23:59:59.000Z

    Interband nonradiative Auger recombination in quantum-well InGaAsP/InP heterostructure lasers has been calculated. It is found that the Auger rate is much reduced in the quasi two-dimensional quantum-well lasers. This suggests that the temperature sensitivity of quantum-well InGaAsP lasers is much less than ordinary structures with much higher values of T/sub 0/ at around room temperatures.

  11. Track 4: Employee Health and Wellness

    Broader source: Energy.gov [DOE]

    ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 4: Employee Health and Wellness

  12. Gradient effects on the fracture of inhomogeneous materials

    SciTech Connect (OSTI)

    Becker, T.L.

    2000-05-01T23:59:59.000Z

    Functionally Graded Materials (FGMs) have a spatial variation in physical properties that can be tailored to meet the needs of a specific application and/or to minimize internal stresses arising from thermal and elastic mismatch. Modeling these materials as inhomogeneous continua allows assessment of the role of the gradient without requiring detailed knowledge of the microstructure. Motivated by the relative difficulty of obtaining analytical solutions to boundary value problems for FGMs, an accurate finite-element code is developed for obtaining numerical planar and axisymmetric linear thermoelastic solutions. In addition an approximate analytical technique for mapping homogeneous-modulus solutions to those for FGMs is assessed and classes of problems to which it applies accurately are identified. The fracture mechanics analysis of FGMs can be characterized by the classic stress intensities, KI and KII, but there has been scarce progress in understanding the role of the modulus gradient in determining fracture initiation and propagation. To address this question, a statistical fracture model is used to correlate near-tip stresses with brittle fracture initiation behavior. This describes the behavior of a material experiencing fracture initiation away from the crack tip. Widely dispersed zones of fracture initiation sites are expected. Finite-length kinks are analyzed to describe the crack path for continuous crack growth. For kink lengths much shorter than the gradient dimension, a parallel stress term describes the deviation of the kinking angle from that for homogeneous materials. For longer kinks there is a divergence of the kink angle predicted by the maximum energy release rate and the pure opening mode criteria.

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

    SciTech Connect (OSTI)

    Arntz, Floyd; /Diversified Tech., Bedford; Kardo-Sysoev, A.; /Ioffe Phys. Tech. Inst.; Krasnykh, A.; /SLAC

    2008-12-16T23:59:59.000Z

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

  14. Potential use of hollow spheres in dual gradient drilling

    E-Print Network [OSTI]

    Vera Vera, Liliana

    2002-01-01T23:59:59.000Z

    . 53 4-18 Relation between the mud level drop inside the drillstring obtained by using both our Spreadsheet and the SMD simulator. A strong linear relationship is depicted. . 53 LIST OF TABLES TABLE Page 2-1 Current subsea pump lifting projects... to the surface, and makes dual gradient possible by keeping the mud hydrostatic pressure in the return lines from being trarismitted to the wellbore. Operationally, the mud returns are diverted from the annulus to the pump suction by a subsea diverter. Some...

  15. High and ulta-high gradient quadrupole magnets

    SciTech Connect (OSTI)

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

    1985-05-01T23:59:59.000Z

    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%.

  16. k-line iterative methods: a conjugate-gradient approach

    SciTech Connect (OSTI)

    Kratzer, D.; Parter, S.V.; Steuerwalt, M.

    1981-03-29T23:59:59.000Z

    The generalized conjugate gradient scheme based on the k-line block Jacobi splitting A = M-N was studied for solving model two-dimensional parabolic and elliptic difference equations AU = F tilde. A represents the matrix ch/sup ..cap alpha../-h/sup 2/..delta../sub h/. Eigenvalues of M/sup -1/N cluster, and the cluster radii decrease as ch/sup ..cap alpha../ or k increases. Computations with k = 4, 8, 16, 32, and ch/sup ..cap alpha../ = 0, h, 2 are discussed.

  17. A stable, rapidly converging conjugate gradient method for energy minimization

    SciTech Connect (OSTI)

    Watowich, S.J.; Meyer, E.S.; Hagstrom, R.; Josephs, R.

    1989-01-01T23:59:59.000Z

    We apply Shanno's conjugate gradient algorithm to the problem of minimizing the potential energy function associated with molecular mechanical calculations. Shanno's algorithm is stable with respect to roundoff errors and inexact line searches and converges rapidly to a minimum. Equally important, this algorithm can improve the rate of convergence to a minimum by a factor of 5 relative to Fletcher-Reeves or Polak-Ribiere minimizers when used within the molecular mechanics package AMBER. Comparable improvements are found for a limited number of simulations when the Polak-Ribiere direction vector is incorporated into the Shanno algorithm. 24 refs., 4 figs., 3 tabs.

  18. Fabrication of high gradient insulators by stack compression

    DOE Patents [OSTI]

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

    2014-04-29T23:59:59.000Z

    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.

  19. Cubic GaN/AlN multiple quantum well photodetector

    SciTech Connect (OSTI)

    DeCuir, E. A. Jr.; Manasreh, M. O. [Department of Electrical Engineering, University of Arkansas, 3217 Bell Engineering Center, Fayetteville, Arkansas 72701 (United States); Tschumak, Elena; Schoermann, J.; As, D. J.; Lischka, K. [Department of Physics, University of Paderborn, Paderborn 33095 (Germany)

    2008-05-19T23:59:59.000Z

    Photodetectors based on intersubband transitions in molecular beam epitaxially grown cubic GaN/AlN multiple quantum wells were fabricated and tested. The presence of the intersubband transition was confirmed by using the optical absorption technique for structures with different well widths. Samples were polished into waveguide configuration on which the devices were fabricated. The photoresponse spectra were collected in the temperature range of 77-215 K under the influence of small bias voltages. All devices exhibit photovoltaic effect where the photoresponse is observed at zero bias voltage. Theoretical calculations of the intersubband transition were performed and found to be in agreement with the observed results.

  20. MEASUREMENTS OF ANISOTROPIC ION TEMPERATURES, NON-THERMAL VELOCITIES, AND DOPPLER SHIFTS IN A CORONAL HOLE

    SciTech Connect (OSTI)

    Hahn, M.; Savin, D. W. [Columbia Astrophysics Laboratory, Columbia University, MC 5247, 550 West 120th Street, New York, NY 10027 (United States)] [Columbia Astrophysics Laboratory, Columbia University, MC 5247, 550 West 120th Street, New York, NY 10027 (United States)

    2013-02-15T23:59:59.000Z

    We present a new diagnostic allowing one to measure the anisotropy of ion temperatures and non-thermal velocities, as well as Doppler shifts with respect to the ambient magnetic field. This method provides new results, as well as an independent test for previous measurements obtained with other techniques. Our spectral data come from observations of a low-latitude, on-disk coronal hole. A potential field source surface model was used to calculate the angle between the magnetic field lines and the line of sight for each spatial bin of the observation. A fit was performed to determine the line widths and Doppler shifts parallel and perpendicular to the magnetic field. For each line width component we derived ion temperatures T {sub i,} and T {sub i, Parallel-To} and non-thermal velocities v {sub nt,} and v {sub nt, Parallel-To }. T {sub i,} was cooler than off-limb polar coronal hole measurements, suggesting increasing collisional cooling with decreasing height. T {sub i, Parallel-To} is consistent with a uniform temperature of (1.8 {+-} 0.2) Multiplication-Sign 10{sup 6} K for each ion. Since parallel ion heating is expected to be weak, this ion temperature should reflect the proton temperature. A comparison between our results and others implies a large proton temperature gradient around 1.02 R {sub Sun }. The non-thermal velocities are thought to be proportional to the amplitudes of various waves. Our results for v {sub nt,} agree with Alfven wave amplitudes inferred from off-limb polar coronal hole line width measurements. Our v {sub nt, Parallel-To} results are consistent with slow magnetosonic wave amplitudes inferred from Fourier analysis of time-varying intensity fluctuations. Doppler shift measurements yield outflows of Almost-Equal-To 5 km s{sup -1} for ions formed over a broad temperature range. This differs from other studies that found a strong Doppler shift dependence on formation temperature.