Sample records for temperature gradient geochemical

  1. 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.

  2. 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.

  3. 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.

  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. 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

  6. 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.

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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...

  17. 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 ...

  18. 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.

  19. 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 ...

  20. 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

  1. 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.

  2. 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

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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...

  11. 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.

  12. 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...

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. DOE/SC0001389 Final technical report: Investigation of uranium attenuation and release at column and pore scales in response to advective geochemical gradients

    SciTech Connect (OSTI)

    Savage, Kaye S. [Wofford College; Zhu, Wenyi [Wofford College; Barnett, Mark O. [Auburn University

    2013-05-13T23:59:59.000Z

    Experimental approach Column experiments were devised to investigate the role of changing fluid composition on mobility of uranium through a sequence of geologic media. Fluids and media were chosen to be relevant to the ground water plume emanating from the former S-3 ponds at the Oak Ridge Integrated Field Research Challenge (ORIFC) site. Synthetic ground waters were pumped upwards at 0.05 mL/minute for 21 days through layers of quartz sand alternating with layers of uncontaminated soil, quartz sand mixed with illite, quartz sand coated with iron oxides, and another soil layer. Increases in pH or concentration of phosphate, bicarbonate, or acetate were imposed on the influent solutions after each 7 pore volumes while uranium (as uranyl) remained constant at 0.1mM. A control column maintained the original synthetic groundwater composition with 0.1mM U. Pore water solutions were extracted to assess U retention and release in relation to the advective ligand or pH gradients. Following the column experiments, subsamples from each layer were characterized using microbeam X-ray absorption spectroscopy (XANES) in conjunction with X-ray fluorescence mapping and compared to sediment core samples from the ORIFC, at SSRL Beam Line 2-3. Results U retention of 55 â?? 67 mg occurred in phosphate >pH >control >acetate >carbonate columns. The mass of U retained in the first-encountered quartz layer in all columns was highest and increased throughout the experiment. The rate of increase in acetate- and bicarbonate-bearing columns declined after ligand concentrations were raised. U also accumulated in the first soil layer; the pH-varied column retained most, followed by the increasing-bicarbonate column. The mass of U retained in the upper layers was far lower. Speciation of U, interpreted from microbeam XANES spectra and XRF maps, varied within and among the columns. Evidence of minor reduction to U(IV) was observed in the first-encountered quartz layer in the phosphate, bicarbonate, and pH columns while only U(VI) was observed in the control and acetate columns. In the soil layer, the acetate and bicarbonate columns both indicate minor reduction to U(IV), but U(VI) predominated in all columns. In the ORIFC soils, U was consistently present as U(VI); sorption appears to be the main mechanism of association for U present with Fe and/or Mn, while U occurring with P appears in discrete particles consistent with a U mineral phase. U in soil locations with no other elemental associations shown by XRF are likely uranium oxide phases.

  19. 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...

  20. HBH-GEOCHEM-GEOPHY

    Energy Science and Technology Software Center (OSTI)

    003015WKSTN00 Hiereachical Bayesian Model for Combining Geochemical and Geophysical Data for Environmental Applications Software   

  1. 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.

  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. Proceedings of the workshop on geochemical modeling

    SciTech Connect (OSTI)

    Not Available

    1986-01-01T23:59:59.000Z

    The following collection of papers was presented at a workshop on geochemical modeling that was sponsored by the Office of Civilian Radioactive Waste Management Program at the Lawrence Livermore National Laboratory (LLNL). The LLNL Waste Management Program sponsored this conference based on their belief that geochemical modeling is particularly important to the radioactive waste disposal project because of the need to predict the consequences of long-term water-rock interactions at the proposed repository site. The papers included in this volume represent a subset of the papers presented at the Fallen Leaf Lake Conference and cover a broad spectrum of detail and breadth in a subject that reflects the diverse research interests of the conference participants. These papers provide an insightful look into the current status of geochemical modeling and illustrate how various geochemical modeling codes have been applied to problems of geochemical interest. The emphasis of these papers includes traditional geochemical modeling studies of individual geochemical systems, the mathematical and theoretical development and refinement of new modeling capabilities, and enhancements of data bases on which the computations are based. The papers in this proceedings volume have been organized into the following four areas: Geochemical Model Development, Hydrothermal and Geothermal Systems, Sedimentary and Low Temperature Environments, and Data Base Development. The participants of this symposium and a complete list of the talks presented are listed in the appendices.

  4. 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

  5. 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...

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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 ...

  12. Novel Coupled Thermochronometric and Geochemical Investigation...

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

    Coupled Thermochronometric and Geochemical Investigation of Blind Geothermal Resources in Fault-Controlled Dilational Corners Novel Coupled Thermochronometric and Geochemical...

  13. Characterizing Microbial Community and Geochemical Dynamics at...

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

    Microbial Community and Geochemical Dynamics at Hydrothermal Vents Using Osmotically Driven Continuous Fluid Characterizing Microbial Community and Geochemical Dynamics at...

  14. WINTERTemplate Geochemical mechanisms of

    E-Print Network [OSTI]

    Borissova, Daniela

    WINTERTemplate 01 Geochemical mechanisms of carbonate equilibria in the system CO2 -H2O-CaCO3 #12 dissolved in soil · Dissolution of CaCO3 · Precipitation of CaCO3 · Physicochemical precipitation (prevention of the CO2 outgassing) #12;07Dissolution of CaCO3 H2CO3 HCO3 - CO3 2- H+ CO3 2- + H+ HCO3 - HCO3

  15. Organic geochemical constraints on tectonic evolution of the North American Midcontinent rift

    SciTech Connect (OSTI)

    Hieshima, G.B. (Exxon Production Research Co., Houston, TX (United States)); Pratt, L.M. (Indiana Univ., Bloomington, IN (United States). Dept. of Geological Sciences)

    1992-01-01T23:59:59.000Z

    The approximately 1.1 Ga Nonesuch Formation, northern Wisconsin and Michigan, represents marine sedimentation in a failed continental rift that is part of the North American Midcontinent rift system. Indicators of thermal maturity based on solvent-extractable (bitumen) and insoluble (kerogen) organic matter suggest marginal to moderate levels of maturity with respect to zones of petroleum generation and preservation. Values of sterane 20S/(20S + 20R) ratio, hopane 22S/(22S + 22R) ratio, methylphenanthrene index, and temperature of maximum pyrolytic yield from Rock-Eval (Tmax) indicate maximum burial temperatures of around 80 C. Geologic constraints indicate maximum burial conditions for the Nonesuch of around 4 km for approximately 50 million years. Overlying sandstones buried the Nonesuch quickly. Assuming a surface temperature of around 20 C yields a geothermal gradient of 15 C/km, significantly lower than predicted based on heat flow in modern rifts. Unless burial histories are grossly inaccurate, geothermal gradients were depressed as a result of thermal insulation by non-radiogenic basalts and/or hydrologic circulation in underlying coarse-grained strata generated an anomalously low geothermal gradient. Hydrothermal circulation was a significant component of mineralization in the structurally complex White Pine deposit, lending credence to the hypothesis that hydrologic circulation caused regionally depressed geothermal gradients. In addition, regional heat flow may have been low as a result of the insulating effect of a thick accumulation of rift basalts represented by the Portage Lake Volcanics. Organic geochemical indicators of thermal alteration provide a framework for interpreting tectonic development of the North American Midcontinent rift system.

  16. 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...

  17. 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.

  18. Geochemical aspects of Michigan waterfloods

    SciTech Connect (OSTI)

    Tinker, G.E.; Barnes, P.F.; Olson, E.E.

    1983-10-01T23:59:59.000Z

    Waterflooding started in the carbonate oil reservoirs of the Northern Michigan Niagaran reef trend in 1978 with Shell's Chester 18 waterflood. Ten projects had been installed by the end of 1982 so that significant operational results are available for evaluation. The design and operating programs initially planned for the projects have been proven successful. Operating data from some of the more mature projects indicate that the understanding and proper management of the geochemical systems for these projects will be crucial to the success of the project. The intent of this paper is to present what is currently known and understood about the geochemistry of Michigan waterfloods. The geochemical system is here defined as all the various interconnected fluid environments constituting the project, namely the fresh water source system, the injection well system, the reservoir, the production wells, the production facilities, and the produced water disposal or reinjection facilities. Problem areas have been identified and corrective action has been taken or planned to counteract the detrimental effects of disruptions to the geochemical system. These upsets are brought about by injection of water into the reservoir where an equilibrium condition had existed between the formation fluids and the rock.

  19. Argonne Geothermal Geochemical Database v2.0

    SciTech Connect (OSTI)

    Harto, Christopher

    2013-05-22T23:59:59.000Z

    A database of geochemical data from potential geothermal sources aggregated from multiple sources as of March 2010. The database contains fields for the location, depth, temperature, pH, total dissolved solids concentration, chemical composition, and date of sampling. A separate tab contains data on non-condensible gas compositions. The database contains records for over 50,000 wells, although many entries are incomplete. Current versions of source documentation are listed in the dataset.

  20. Argonne Geothermal Geochemical Database v2.0

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

    Harto, Christopher

    A database of geochemical data from potential geothermal sources aggregated from multiple sources as of March 2010. The database contains fields for the location, depth, temperature, pH, total dissolved solids concentration, chemical composition, and date of sampling. A separate tab contains data on non-condensible gas compositions. The database contains records for over 50,000 wells, although many entries are incomplete. Current versions of source documentation are listed in the dataset.

  1. 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

  2. Merging high resolution geophysical and geochemical surveys to...

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

    high resolution geophysical and geochemical surveys to reduce exploration risk at Glass Buttes, Oregon Merging high resolution geophysical and geochemical surveys to reduce...

  3. Geochemical aspects of Michigan waterfloods

    SciTech Connect (OSTI)

    Tinker, G.E.; Barnes, P.F.; Olson, E.E.; Wright, M.P.

    1983-01-01T23:59:59.000Z

    Waterflooding started in the carbonate oil reservoirs of the N. Michigan Niagaran reef trend in 1978 with Shell's Chester 18 waterflood. Ten projects had been installed by the end of 1982 so that significant operational results are available for evaluation. This study presents what is currently known and understood about the geochemistry of Michigan waterfloods. Project monitoring procedures, established to control and optimize waterflood operations, have made it possible to develop the proper approach to the geochemical disruptions. The more important items in this program are the measurement of produced and injected volumes, transient pressure analyses, injection well profile surveys, chemical analysis of the injection and production fluid samples, radioactive injection tracers, and continuous bottom-hole pressures from submersible pumps. 15 references.

  4. Microbiological and Geochemical Heterogeneity in an In Situ

    E-Print Network [OSTI]

    Uranium Bioremediation; Field Site; Helen A. Vrionis; Robert T. Anderson; Irene Ortiz-bernad; Kathleen R. O’neill; Philip E. Long; Derek R. Lovley

    2005-01-01T23:59:59.000Z

    The geochemistry and microbiology of a uranium-contaminated subsurface environment that had undergone two seasons of acetate addition to stimulate microbial U(VI) reduction was examined. There were distinct horizontal and vertical geochemical gradients that could be attributed in large part to the manner in which acetate was distributed in the aquifer, with more reduction of Fe(III) and sulfate occurring at greater depths and closer to the point of acetate injection. Clone libraries of 16S rRNA genes derived from sediments and groundwater indicated an enrichment of sulfate-reducing bacteria in the order Desulfobacterales in sediment and groundwater samples. These samples were collected nearest the injection gallery where microbially reducible Fe(III) oxides were highly depleted, groundwater sulfate concentrations were low, and increases in acid volatile sulfide were observed in the sediment. Further down-gradient, metal-reducing conditions were present as indicated by intermediate Fe(II)/Fe(total) ratios, lower acid volatile sulfide values, and increased abundance of 16S rRNA gene sequences belonging to the dissimilatory Fe(III)- and U(VI)-reducing family Geobacteraceae. Maximal Fe(III) and U(VI) reduction correlated with maximal recovery of Geobacteraceae 16S rRNA gene sequences in both groundwater and sediment; however, the sites at which these maxima occurred were spatially separated within the aquifer. The substantial microbial and geochemical heterogeneity at this site demonstrates that attempts should be made to deliver acetate in a more uniform manner and that closely

  5. Geochemical and geomechanical effects on wellbore cement fractures

    SciTech Connect (OSTI)

    Um, Wooyong; Jung, Hun Bok; Kabilan, Senthil; Fernandez, Carlos A.; Brown, Christopher F.

    2014-01-01T23:59:59.000Z

    Experimental studies were conducted using batch reactors, X-ray microtomograpy (XMT), and computational fluid dynamics (CFD) simulation to determine changes in cement fracture surfaces, fluid flow pathways, and permeability with geochemical and geomechanical processes. Composite Portland cement-basalt caprock core with artificial fractures was prepared and reacted with CO2-saturated groundwater at 50°C and 10 MPa for 3 to 3.5 months under static conditions to understand the geochemical and geomechanical effects on the integrity of wellbores containing defects. Cement-basalt interface samples were subjected to mechanical stress at 2.7 MPa before the CO2 reaction. XMT provided three-dimensional (3-D) visualization of the opening and interconnection of cement fractures due to mechanical stress. After the CO2 reaction, XMT images revealed that calcium carbonate precipitation occurred extensively within the fractures in the cement matrix, but only partially along fractures located at the cement-basalt interface. The permeability calculated based on CFD simulation was in agreement with the experimentally measured permeability. The experimental results imply that the wellbore cement with fractures is likely to be healed during exposure to CO2-saturated groundwater under static conditions, whereas fractures along the cement-caprock interface are still likely to remain vulnerable to the leakage of CO2. CFD simulation for the flow of different fluids (CO2-saturated brine and supercritical CO2) using a pressure difference of 20 kPa and 200 kPa along ~2 cm-long cement fractures showed that a pressure gradient increase resulted in an increase of CO2 fluids flux by a factor of only ~3-9 because the friction of CO2 fluids on cement fracture surfaces increased with higher flow rate as well. At the same pressure gradient, the simulated flow rate was higher for supercritical CO2 than CO2-saturated brine by a factor of only ~2-3, because the viscosity of supercritical CO2 is much lower than that of CO2-saturated brine. The study suggests that in deep geological reservoirs the geochemical and geomechanical processes have coupled effects on the wellbore cement fracture evolution and fluid flow along the fracture surfaces.

  6. 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.

  7. 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.

  8. 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

  9. Geochemical Implications of Stirring and Mixing

    E-Print Network [OSTI]

    Rudge, John

    Geochemical Implications of Stirring and Mixing in the Earth's Mantle John Frederick Rudge Trinity Sciences and Applied Mathematics, mostly in the form of papers in my rucksack as I have cycled back constrain the melting, melt mi- gration, and solid state convection that occurs in the Earth's mantle

  10. 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

  11. 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

  12. Geochemical engineering and materials program plan

    SciTech Connect (OSTI)

    None

    1982-08-01T23:59:59.000Z

    The Department of Energy (DOE) was designated as lead agency in discharging the overall legislative mandate for federal R&D to assist the private sector in developing appropriate technology for exploiting geothermal energy resources. The Geochemical Engineering and Materials (GEM) Program was conceived, as part of DOE'S overall strategy, to address specific and plant-wide problems and uncertainties in the use of materials and in geochemical engineering. This program assists industry in the conduct of long-term,high-risk R&D needed to overcome the significant technical and economic GEM-related obstacles faced by developers and potential developers of this alternative energy source. The program focuses on: (1) Increasing the knowledge about the properties of materials and their performance under geothermal energy system conditions; (2) Developing and utilizing more reliable and/or cost-effective materials than previously available; and (3) Developing a greater understanding of and control over geochemical processes during fluid production and transport, energy conversion, and waste management. As a stand-alone program and as support to other DOE geothermal technology development programs, the GEM Program contributes to the feasibility of designing and operating efficient, reliable, and safe fluid handling and energy conversion systems.

  13. 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.

  14. Alteration And Geochemical Zoning In Bodie Bluff, Bodie Mining...

    Open Energy Info (EERE)

    Alteration And Geochemical Zoning In Bodie Bluff, Bodie Mining District, Eastern California Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article:...

  15. Trace Element Geochemical Zoning in the Roosevelt Hot Springs...

    Open Energy Info (EERE)

    Capuano. 1980. Trace Element Geochemical Zoning in the Roosevelt Hot Springs Thermal Area, Utah. In: Transactions. GRC Annual Meeting; 09091980; Salt Lake City, UT. Salt...

  16. Merging High Resolution Geophysical and Geochemical Surveys to...

    Open Energy Info (EERE)

    Buttes, Oregon Geothermal Project Jump to: navigation, search Last modified on July 22, 2011. Project Title Merging High Resolution Geophysical and Geochemical Surveys to Reduce...

  17. Geochemical Controls on Contaminant Uranium in Vadose Hanford...

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

    Controls on Contaminant Uranium in Vadose Hanford Formation Sediments at the 200 Area and 300 Area, Hanford Site, Geochemical Controls on Contaminant Uranium in Vadose Hanford...

  18. Geochemical characterization of geothermal systems in the Great...

    Open Energy Info (EERE)

    for geothermal energy in the Great Basin. In addition, understanding the geochemical evolution of these various types of systems will provide important insights into the possible...

  19. Merging high resolution geophysical and geochemical surveys to...

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

    Merging high resolution geophysical and geochemical surveys to reduce exploration risk at Glass Buttes, Oregon Patrick Walsh Ormat Nevada Inc. Innovative technologies May 19, 2010...

  20. 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.

  1. DNA-based methods of geochemical prospecting

    DOE Patents [OSTI]

    Ashby, Matthew (Mill Valley, CA)

    2011-12-06T23:59:59.000Z

    The present invention relates to methods for performing surveys of the genetic diversity of a population. The invention also relates to methods for performing genetic analyses of a population. The invention further relates to methods for the creation of databases comprising the survey information and the databases created by these methods. The invention also relates to methods for analyzing the information to correlate the presence of nucleic acid markers with desired parameters in a sample. These methods have application in the fields of geochemical exploration, agriculture, bioremediation, environmental analysis, clinical microbiology, forensic science and medicine.

  2. 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

  3. 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

  4. Upscaling geochemical reaction rates using pore-scale network modeling

    E-Print Network [OSTI]

    Peters, Catherine A.

    . To examine the scaling behavior of reaction kinetics, these continuum-scale rates from the network model as a valuable research tool for examining upscaling of geochemical kinetics. The pore-scale model allowsUpscaling geochemical reaction rates using pore-scale network modeling Li Li, Catherine A. Peters

  5. 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

  6. 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

  7. Thermodynamic Data for Geochemical Modeling of Carbonate Reactions Associated with CO2 Sequestration – Literature Review

    SciTech Connect (OSTI)

    Krupka, Kenneth M.; Cantrell, Kirk J.; McGrail, B. Peter

    2010-09-28T23:59:59.000Z

    Permanent storage of anthropogenic CO2 in deep geologic formations is being considered as a means to reduce the concentration of atmospheric CO2 and thus its contribution to global climate change. To ensure safe and effective geologic sequestration, numerous studies have been completed of the extent to which the CO2 migrates within geologic formations and what physical and geochemical changes occur in these formations when CO2 is injected. Sophisticated, computerized reservoir simulations are used as part of field site and laboratory CO2 sequestration studies. These simulations use coupled multiphase flow-reactive chemical transport models and/or standalone (i.e., no coupled fluid transport) geochemical models to calculate gas solubility, aqueous complexation, reduction/oxidation (redox), and/or mineral solubility reactions related to CO2 injection and sequestration. Thermodynamic data are critical inputs to modeling geochemical processes. The adequacy of thermodynamic data for carbonate compounds has been identified as an important data requirement for the successful application of these geochemical reaction models to CO2 sequestration. A review of thermodynamic data for CO2 gas and carbonate aqueous species and minerals present in published data compilations and databases used in geochemical reaction models was therefore completed. Published studies that describe mineralogical analyses from CO2 sequestration field and natural analogue sites and laboratory studies were also reviewed to identify specific carbonate minerals that are important to CO2 sequestration reactions and therefore require thermodynamic data. The results of the literature review indicated that an extensive thermodynamic database exists for CO2 and CH4 gases, carbonate aqueous species, and carbonate minerals. Values of ?fG298° and/or log Kr,298° are available for essentially all of these compounds. However, log Kr,T° or heat capacity values at temperatures above 298 K exist for less than approximately one-third of these compounds. Because the temperatures of host formations that will be used for CO2 injection and sequestration will be at tempera¬tures in the range of 50ºC to 100ºC or greater, the lack of high temperature thermodynamic values for key carbonate compounds especially minerals, will impact the accuracy of some modeling calculations.

  8. 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 ...

  9. Geochemical Data on Waters, Gases, Scales, and Rocks from the...

    Open Energy Info (EERE)

    Jump to: navigation, search OpenEI Reference LibraryAdd to library Report: Geochemical Data on Waters, Gases, Scales, and Rocks from the Dixie Valley Region, Nevada (1996-1999)...

  10. Geochemical Data for 95 Thermal and Nonthermal Waters of the...

    Open Energy Info (EERE)

    Jump to: navigation, search OpenEI Reference LibraryAdd to library Report: Geochemical Data for 95 Thermal and Nonthermal Waters of the Valles Caldera - Southern Jemez Mountains...

  11. Temporal Geochemical Variations In Volatile Emissions From Mount...

    Open Energy Info (EERE)

    Geochemical Variations In Volatile Emissions From Mount St Helens, Usa, 1980-1994 Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Temporal...

  12. A Reconnaissance Geochemical Study Of La Primavera Geothermal...

    Open Energy Info (EERE)

    Study Of La Primavera Geothermal Area, Jalisco, Mexico Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: A Reconnaissance Geochemical Study Of La...

  13. A general-purpose, geochemical reservoir simulator

    SciTech Connect (OSTI)

    Liu, X.; Ortoleva, P.

    1996-12-31T23:59:59.000Z

    A geochemical simulator for the analysis of coupled reaction and transport processes is presented. The simulator is based on the numerical solution of the equations of coupled multi-phase fluid flow, species transport, energy balance and rock/fluid reactions. It also accounts for the effects of grain growth/dissolution and the alteration of porosity and permeability due to mineral reactions. The simulator can be used to analyze core floods, single-well scenarios and multiple production/injection well systems on the reservoir scale. Additionally, the simulator provides two flow options: the Darcy law for fluid flow in porous media and the Brinkman law that subsumes both free and porous medium flows. The simulator was tested using core acidizing data and results were in good agreement with laboratory observations. The simulator was applied to analyze matrix acidizing treatments for a horizontal well. The evolution of the skin factor was predicted and the optimal volume of acid required to remove the near-wellbore damage was determined. Reactive fluid infiltration was shown to lead to reaction-front fingering under certain conditions. Viscosity contrast in multiphase flow could also result in viscous fingering. Examples in this study also address these nonlinear fingering phenomena. A waterflood on the reservoir scale was analyzed and simulation results show that scale formation during waterfloods can occur far beyond injection wells. Two cases of waste disposal by deep well injection were evaluated and our simulation results were consistent with field measured data.

  14. 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.

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

    SciTech Connect (OSTI)

    Christensen, O.D.

    1980-12-01T23:59:59.000Z

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

  16. 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.

  17. 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.

  18. 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.

  19. 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 |...

  20. 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.

  1. 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

  2. Crustal melting in the Himalayan orogen : field, geochemical and geochronological studies in the Everest region, Nepal

    E-Print Network [OSTI]

    Viskupic, Karen M. (Karen Marie), 1975-

    2003-01-01T23:59:59.000Z

    A combination of field studies and geochemical techniques were used to investigate the timing and processes involved in leucogranite generation in the Everest region of the Himalayan orogen. Geochemical investigations ...

  3. PRELIMINARY RESULTS OF THE PETROLOGICAL-GEOCHEMICAL COMPONENT TO THE BATHOLITHS PROJECT

    E-Print Network [OSTI]

    Wetmore, Paul H.

    PRELIMINARY RESULTS OF THE PETROLOGICAL- GEOCHEMICAL COMPONENT TO THE BATHOLITHS PROJECT Paul H. Wetmore Theresa Kayzar Mihai Ducea P. Jonathan Patchett George Gehrels The petrologic during batholith generation. Petrologic and geochemical studies of arc-related, igneous and meta

  4. Geochemical Modeling of ILAW Lysimeter Water Extracts

    SciTech Connect (OSTI)

    Cantrell, Kirk J.

    2014-12-22T23:59:59.000Z

    Geochemical modeling results of water extracts from simulated immobilized low-activity waste (ILAW) glasses, placed in lysimeters for eight years suggest that the secondary phase reaction network developed using product consistency test (PCT) results at 90°C may need to be modified for field conditions. For sediment samples that had been collected from near the glass samples, the impact of glass corrosion could be readily observed based upon the pH of their water extracts. For unimpacted sediments the pH ranged from 7.88 to 8.11 with an average of 8.04. Sediments that had observable impacts from glass corrosion exhibited elevated pH values (as high as 9.97). For lysimeter sediment samples that appear to have been impacted by glass corrosion to the greatest extent, saturation indices determined for analcime, calcite, and chalcedony in the 1:1 water extracts were near equilibrium and were consistent with the secondary phase reaction network developed using PCT results at 90°C. Fe(OH)3(s) also appears to be essentially at equilibrium in extracts impacted by glass corrosion, but with a solubility product (log Ksp) that is approximately 2.13 units lower than that used in the secondary phase reaction network developed using PCT results at 90°C. The solubilities of TiO2(am) and ZrO2(am) also appear to be much lower than that assumed in the secondary phase reaction network developed using PCT results at 90°C. The extent that the solubility of TiO2(am) and ZrO2(am) were reduced relative to that assumed in the secondary phase reaction network developed using PCT results at 90°C could not be quantified because the concentrations of Ti and Zr in the extracts were below the estimated quantification limit. Gibbsite was consistently highly oversaturated in the extract while dawsonite was at or near equilibrium. This suggests that dawsonite might be a more suitable phase for the secondary phase reaction network than gibbsite under field conditions. This may be due to the availability of carbonate that exists in the Hanford sediments as calcite. A significant source of carbonate was not available in the PCTs and this may account for why this phase did not appear in the PCTs. Sepiolite was consistently highly undersaturated, suggesting that another phase controls the solubility of magnesium. For samples that were most impacted by the effects of glass corrosion, magnesite appears to control glass corrosion. For samples that show less impacts from glass corrosion, clinochlore-7A or saponite-Mg appears to control the magnesium concentrations. For zinc, it appears that zincite is a better candidate than Zn(OH)2-? for controlling zinc concentrations in the extracts; however, in some samples all zinc phases considered were highly oversaturated. As a result the phase that controls zinc concentrations in the lysimeter extracts remains uncertain.

  5. Remote Raman - laser induced breakdown spectroscopy (LIBS) geochemical investigation under Venus atmospheric conditions

    SciTech Connect (OSTI)

    Clegg, Sanuel M [Los Alamos National Laboratory; Barefield, James E [Los Alamos National Laboratory; Humphries, Seth D [Los Alamos National Laboratory; Wiens, Roger C [Los Alamos National Laboratory; Vaniman, D. T. [Los Alamos National Laboratory; Sharma, S. K. [UNIV OF HAWAII; Misra, A. K. [UNIV OF HAWAII; Dyar, M. D. [MT. HOLYOKE COLLEGE; Smrekar, S. E. [JET PROPULSION LAB.

    2010-12-13T23:59:59.000Z

    The extreme Venus surface temperatures ({approx}740 K) and atmospheric pressures ({approx}93 atm) create a challenging environment for surface missions. Scientific investigations capable of Venus geochemical observations must be completed within hours of landing before the lander will be overcome by the harsh atmosphere. A combined remote Raman - LIBS (Laser Induced Breakdown Spectroscopy) instrument is capable of accomplishing the geochemical science goals without the risks associated with collecting samples and bringing them into the lander. Wiens et al. and Sharma et al. demonstrated that both analytical techniques can be integrated into a single instrument capable of planetary missions. The focus of this paper is to explore the capability to probe geologic samples with Raman - LIBS and demonstrate quantitative analysis under Venus surface conditions. Raman and LIBS are highly complementary analytical techniques capable of detecting both the mineralogical and geochemical composition of Venus surface materials. These techniques have the potential to profoundly increase our knowledge of the Venus surface composition, which is currently limited to geochemical data from Soviet Venera and VEGA landers that collectively suggest a surface composition that is primarily tholeiitic basaltic with some potentially more evolved compositions and, in some locations, K-rich trachyandesite. These landers were not equipped to probe the surface mineralogy as can be accomplished with Raman spectroscopy. Based on the observed compositional differences and recognizing the imprecise nature of the existing data, 15 samples were chosen to constitute a Venus-analog suite for this study, including five basalts, two each of andesites, dacites, and sulfates, and single samples of a foidite, trachyandesite, rhyolite, and basaltic trachyandesite under Venus conditions. LIBS data reduction involved generating a partial least squares (PLS) model with a subset of the rock powder standards to quantitatively determine the major elemental abundance of the remaining samples. PLS analysis suggests that the major element compositions can be determined with root mean square errors ca. 5% (absolute) for SiO{sub 2}, Al{sub 2}O{sub 3}, Fe{sub 2}O{sub 3}(total), MgO, and CaO, and ca. 2% or less for TiO{sub 2}, Cr{sub 2}O{sub 3}, MnO, K{sub 2}O, and Na{sub 2}O. Finally, the Raman experiments have been conducted under supercritical CO{sub 2} involving single-mineral and mixed-mineral samples containing talc, olivine, pyroxenes, feldspars, anhydrite, barite, and siderite. The Raman data have shown that the individual minerals can easily be identified individually or in mixtures.

  6. argentina mineralogical geochemical: Topics by E-print Network

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

    argentina mineralogical geochemical First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 A shocking state:...

  7. Synthesis of organic geochemical data from the Eastern Gas Shales

    SciTech Connect (OSTI)

    Zielinski, R.E.; McIver, R.D.

    1982-01-01T23:59:59.000Z

    Over 2400 core and cuttings samples of Upper Devonian shales from wells in the Appalachian, Illinois, and Michigan Basins have been characterized by organic geochemical methods to provide a basis for accelerating the exploitation of this unconventional, gas-rich resource. This work was part of a program initiated to provide industry with criteria for locating the best areas for future drilling and for the development of stimulation methods that will make recovery of the resource economically attractive. The geochemical assessment shows that the shale, in much of the Appalachian, Illinois, and Michigan Basins is source rock that is capable of generating enormous quantities of gas. In some areas the shales are also capable of generating large quantities of oil as well. The limiting factors preventing these sources from realizing most of their potential are their very low permeabilities and the paucity of potential reservoir rocks. This geochemical data synthesis gives direction to future selection of sites for stimulation research projects in the Appalachian Basin by pinpointing those areas where the greatest volumes of gas are contained in the shale matrix. Another accomplishment of the geochemical data synthesis is a new estimate of the total resource of the Appalachian Basin. The new estimate of 2500 TCF is 25 percent greater than the highest previous estimates. This gives greater incentive to government and industry to continue the search for improved stimulation methods, as well as for improved methods for locating the sites where those improved stimulation methods can be most effectively applied.

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. Microbial distributions detected by an oligonucleotide microarray across geochemical zones associated with methane in marine sediments from the Ulleung Basin

    SciTech Connect (OSTI)

    Briggs, Brandon R.; Graw, Michael; Brodie, Eoin L.; Bahk, Jang-Jun; Kim, Sung-Han; Hyun, Jung-Ho; Kim, Ji-Hoon; Torres, Marta; Colwell, Frederick S.

    2013-11-01T23:59:59.000Z

    The biogeochemical processes that occur in marine sediments on continental margins are complex; however, from one perspective they can be considered with respect to three geochemical zones based on the presence and form of methane: sulfate–methane transition (SMTZ), gas hydrate stability zone (GHSZ), and free gas zone (FGZ). These geochemical zones may harbor distinct microbial communities that are important in biogeochemical carbon cycles. The objective of this study was to describe the microbial communities in sediments from the SMTZ, GHSZ, and FGZ using molecular ecology methods (i.e. PhyloChip microarray analysis and terminal restriction fragment length polymorphism (T-RFLP)) and examining the results in the context of non-biological parameters in the sediments. Non-metric multidimensional scaling and multi-response permutation procedures were used to determine whether microbial community compositions were significantly different in the three geochemical zones and to correlate samples with abiotic characteristics of the sediments. This analysis indicated that microbial communities from all three zones were distinct from one another and that variables such as sulfate concentration, hydrate saturation of the nearest gas hydrate layer, and depth (or unmeasured variables associated with depth e.g. temperature, pressure) were correlated to differences between the three zones. The archaeal anaerobic methanotrophs typically attributed to performing anaerobic oxidation of methane were not detected in the SMTZ; however, the marine benthic group-B, which is often found in SMTZ, was detected. Within the GHSZ, samples that were typically closer to layers that contained higher hydrate saturation had indicator sequences related to Vibrio-type taxa. These results suggest that the biogeographic patterns of microbial communities in marine sediments are distinct based on geochemical zones defined by methane.

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. Geochemical Prospecting of Hydrocarbons in Frontier Basins of India* By

    E-Print Network [OSTI]

    B. Kumar; D. J. Patil; G. Kalpana; C. Vishnu Vardhan

    India has 26 sedimentary basins with a basinal area of approximately 1.8x 10 6 km 2 (excluding deep waters), out of which seven are producing basins and two have proven potential. Exploration efforts in other basins, called “frontier basins ” are in progress. These basins are characterized by varied geology, age, tectonics, and depositional environments. Hydrocarbon shows in many of these basins are known, and in few basins oil and gas have flowed in commercial /non-commercial quantities. Within the framework of India Hydrocarbon Vision – 2025 and New Exploration Licensing Policy, there is a continuous increase in area under active exploration. The asset management concept with multi-disciplinary teams has created a demand for synergic application of risk-reduction technologies, including surface geochemical surveys. National Geophysical Research Institute (NGRI), Hyderabad, India has initiated/planned surface geochemical surveys composed of gas chromatographic and carbon isotopic analyses in few of the frontier basins of India. The adsorbed soil gas data in one of the basins (Saurashtra basin, Gujarat) has shown varied concentrations of CH4 to C4H10. The C1 concentration varies between 3 to 766 ppb and ??C2+, 1 to 543 ppb. This basin has thin soil cover and the Mesozoic sediments (probable source rocks) are overlain by thick cover of Deccan Traps. The scope and perspective of geochemical surveys in frontier basins of India are presented here.

  2. Geochemical evolution of Mexicali Valley groundwaters

    SciTech Connect (OSTI)

    Makdisi, R.S.; Truesdell, A.H.; Thompson, J.M.; Coplen, T.B.; Sanchez R., J.

    1982-08-10T23:59:59.000Z

    Isotopic and chemical compositions of Mexicali Valley groundwaters vary widely. Observed variations reflect different water origins, mineral-water reactions, lateral variations of delta facies as well as evaporation. Regional treatment of the groundwater data shows that northern and central regions are a mixture of old and new Colorado River water. Variations in water chemistry result from different groundwaters origins and the effects of lateral delta facies changes. Dissolution of gypsum and precipitation of carbonates, silicates, and phosphates are suggested. The eastern Mesa de San Luis and southern region water originates primarily from the Gila River catchment area. This water is undersaturated with respect to gypsum and carbonates and is oversaturated with respect to silicates. Most of the western groundwaters are a mixture of Colorado River and geothermal waters in the proximity of the Cerro Prieto geothermal field. Recharge to the geothermal aquifer is from the west as well as the north and east. Calcite is being precipitated out as the groundwater temperatures rise in response to the geothermal anomaly. Other western groundwaters reflect a dominant mixture of Colorado River water and evaporated lake water. Some Western groundwater samples suggest dilution by local rainwater and/or irrigation water.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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:

  8. 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)

  9. 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

  10. Review of geochemical measurement techniques for a nuclear waste repository in bedded salt

    SciTech Connect (OSTI)

    Knauss, K.G.; Steinborn, T.L.

    1980-05-22T23:59:59.000Z

    A broad, general review is presented of geochemical measurement techniques that can provide data necessary for site selection and repository effectiveness assessment for a radioactive waste repository in bedded salt. The available measurement techniques are organized according to the parameter measured. The list of geochemical parameters include all those measurable geochemical properties of a sample whole values determine the geochemical characteristics or behavior of the system. For each technique, remarks are made pertaining to the operating principles of the measurement instrument and the purpose for which the technique is used. Attention is drawn to areas where further research and development are needed.

  11. Preclosure Monitoring and Performance Confirmation at Yucca Mountain: Applicability of Geophysical, Geohydrological, and Geochemical Methods

    E-Print Network [OSTI]

    Tsang, C.F.

    2010-01-01T23:59:59.000Z

    properties of rock and geochemical properties of rock andDynamic Elastic Properties of Sedimentary Rocks, Geophysics,since the elastic properties of rock are not affected

  12. 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)

  13. High-resolution stratigraphic correlations and geochemical analyses, Cretaceous Niobrara formation, northwestern Denver-Julesburg Basin

    SciTech Connect (OSTI)

    Rodriguez, T.E.; Pratt, L.M.

    1985-05-01T23:59:59.000Z

    The middle Santonian-lower Campanian part of the Smoky Hill Member of the Niobrara Formation represents a fourth-order regressive-transgressive cyclotherm. Studies of this interval have improved our understanding of the influence of depositional environments and structural setting on distributions of organic matter in epicontinental marine strata. Geochemical analyses of fresh quarried sections at Lyons and LaPorte, Colorado, show that, in general, C/sub org/ (organic carbon) levels are highest between mid-regression and mid-transgression. Rhythmic fluctuations of C/sub carb/ (carbonate carbon) and C/sub org/ correspond to limestone-marlstone bedding couplets at a scale of 15-20 cm (6-8 in.). Pronounced lateral variations between Lyons and LaPorte exist in C/sub org/, HI (pyrolytic hydrogen index), sediment accumulation rates, and T/sub max/ (temperature of maximum pyrolytic yield). Comparisons of geochemical averages at Lyons and LaPorte indicate an elevated thermal maturity at Lyons and depositional conditions more favorable for preservation of marine organic matter at LaPorte. In both sections, C/sub org/ and C/sub carb/ show strong negative correlations, possibly reflecting cyclic climatic controls on the development of bedding couplets. High-resolution stratigraphic correlations of 100.000-year or smaller intervals between Boulder and Owl Canyon, Colorado, based on wide-spread bentonites and bedding couplets, reveal a paleostructural high near Lyons. Shallow-water conditions and increased turbulence over this high are reflected in sediment accumulation rates only 60% of those at LaPorte. Increased amounts and hydrogen richness of organic matter at LaPorte may reflect a deeper water, more quiescent depositional setting.

  14. u.s. DEPARTMENT OF ENERGY EERE PROJECT MANAGEMENT CENTER NEPA...

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

    are not limited to (a) Geological, geophysical (sudl as gravity, magnetic, electncal, seismic, radar, and temperature gradient). geochemical, and engineering surveys and mapping,...

  15. 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.

  16. 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.

  17. 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 ...

  18. 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 ...

  19. 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) ...

  20. 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.

  1. Surface and Subsurface Geochemical Monitoring of an EOR-CO2 Field: Buracica, Brazil

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Surface and Subsurface Geochemical Monitoring of an EOR-CO2 Field: Buracica, Brazil C. Magnier1, V Monitoring of an EOR-CO2 Field: Buracica, Brazil -- This paper presents a surface and subsurface geochemical survey of the Buracica EOR-CO2 field onshore Brazil. We adopted a methodology coupling the stable

  2. MULTI-SCALE ANALYSIS OF MULTIPARAMETER GEOPHYSICAL AND GEOCHEMICAL DATA FROM

    E-Print Network [OSTI]

    Williams-Jones, Glyn

    MULTI-SCALE ANALYSIS OF MULTIPARAMETER GEOPHYSICAL AND GEOCHEMICAL DATA FROM ACTIVE VOLCANIC Name: MAURI Guillaume Degree: PhD of Science Title of Thesis: Multi-scale analysis of multiparameter geophysical and geochemical data from active volcanic systems Examining Committee: Chair: Dr John Clague

  3. Geochemical and Isotopic Interpretations of Groundwater Flow in the Oasis Valley Flow System, Southern Nevada

    SciTech Connect (OSTI)

    J.M. Thomas; F.C. Benedict, Jr.; T.P. Rose; R.L. Hershey; J.B. Paces; Z.E. Peterman; I.M. Farnham; K.H. Johannesson; A.K. Singh; K.J. Stetzenbach; G.B. Hudson; J.M. Kenneally; G.F. Eaton; D.K. Smith

    2003-01-08T23:59:59.000Z

    This report summarizes the findings of a geochemical investigation of the Pahute Mesa-Oasis Valley groundwater flow system in southwestern Nevada. It is intended to provide geochemical data and interpretations in support of flow and contaminant transport modeling for the Western and Central Pahute Mesa Corrective Action Units.

  4. Geochemical responses in peat groundwater over Attawapiskat kimberlites, James Bay Lowlands, Canada and their application to

    E-Print Network [OSTI]

    Geochemical responses in peat groundwater over Attawapiskat kimberlites, James Bay Lowlands, Canada.sader@mmg.com) ABSTRACT: Peat groundwater compositions at depths of 0.4 and 1.1 m below ground surface in the Attawapiskat on hydrogeological measurements and variations in peat groundwater geochemical parameters (pH and EC are high

  5. Hydrological and geochemical investigations of selenium behavior at Kesterson Reservoir

    SciTech Connect (OSTI)

    Benson, S.M.; Tokunaga, T.K.; Zawislanski, P.; Yee, A.W.; Daggett, J.S.; Oldfather, J.M.; Tsao, L.; Johannis, P.W.

    1990-10-01T23:59:59.000Z

    From 1985 to the present we have studied the behavior of selenium in various habitats and environments at Kesterson reservoir, shifting emphasis as remedial actions altered the physical setting. Investigations have evaluated the efficacy of several remedial alternatives, from innovative techniques relying on the complex geochemical behavior of selenium alternatives, from innovative techniques relying on the complex geochemical behavior of selenium in aquatic environments to conventional excavation schemes. Results of these studies supported two cost-effective remedial measures; drain water deliveries were terminated in 1986 and, in 1988, 1 million cubic yards of soil were imported and used to fill the low lying areas of the former Kesterson Reservoir. To date, these two actions appear to have eliminated the aquatic habitat that caused waterfowl death and deformity at Kesterson from the early 1980's to 1987. Biological, surface water and groundwater monitoring data collected by the USBR indicate that Kesterson is now a much safer environment than in past years when drainage water containing 300{mu}g/l of selenium was delivered to the Reservoir. The continued presence of a large inventory of selenium within the upper portions of unfilled areas of Kesterson Reservoir and immediately below the fill material requires that a continued awareness of the status of this inventory be maintained and improved upon. 83 refs., 130 figs., 19 tabs.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Temperature Data Evaluation

    SciTech Connect (OSTI)

    Gillespie, David

    2003-03-01T23:59:59.000Z

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

  12. The hydrogeologic-geochemical model of Cerro Prieto revisited

    SciTech Connect (OSTI)

    Lippmann, M.J.; Halfman, S.E.; Truesdell, A.H.; Manon M., A.

    1989-01-01T23:59:59.000Z

    As the exploitation of the Cerro Prieto, Mexico, geothermal field continues, there is increasing evidence that the hydrogeologic model developed by Halfman et al. (1984, 1986) presents the basic features controlling the movement of geothermal fluids in the system. At the present time the total installed capacity at Cerro Prieto is 620 MWe requiring the production of more than 10,500 tonnes/hr of a brine-steam mixture. This significant rate of fluid production has resulted in changes in reservoir thermodynamic conditions and in the chemistry of the produced fluids. After reviewing the hydrogeologic-geochemical model of Cerro Prieto, some of the changes observed in the field due to its exploitation are discussed and interpreted on the basis of the model. 21 refs., 11 figs., 1 tab.

  13. WATEQ3 geochemical model: thermodynamic data for several additional solids

    SciTech Connect (OSTI)

    Krupka, K.M.; Jenne, E.A.

    1982-09-01T23:59:59.000Z

    Geochemical models such as WATEQ3 can be used to model the concentrations of water-soluble pollutants that may result from the disposal of nuclear waste and retorted oil shale. However, for a model to competently deal with these water-soluble pollutants, an adequate thermodynamic data base must be provided that includes elements identified as important in modeling these pollutants. To this end, several minerals and related solid phases were identified that were absent from the thermodynamic data base of WATEQ3. In this study, the thermodynamic data for the identified solids were compiled and selected from several published tabulations of thermodynamic data. For these solids, an accepted Gibbs free energy of formation, ..delta..G/sup 0//sub f,298/, was selected for each solid phase based on the recentness of the tabulated data and on considerations of internal consistency with respect to both the published tabulations and the existing data in WATEQ3. For those solids not included in these published tabulations, Gibbs free energies of formation were calculated from published solubility data (e.g., lepidocrocite), or were estimated (e.g., nontronite) using a free-energy summation method described by Mattigod and Sposito (1978). The accepted or estimated free energies were then combined with internally consistent, ancillary thermodynamic data to calculate equilibrium constants for the hydrolysis reactions of these minerals and related solid phases. Including these values in the WATEQ3 data base increased the competency of this geochemical model in applications associated with the disposal of nuclear waste and retorted oil shale. Additional minerals and related solid phases that need to be added to the solubility submodel will be identified as modeling applications continue in these two programs.

  14. 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.

  15. 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...

  16. 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

  17. 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).

  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. Migratory patterns of American shad (Alosa sapidissima) revealed by natural geochemical tags in otoliths

    E-Print Network [OSTI]

    Walther, Benjamin (Benjamin Dwaine)

    2007-01-01T23:59:59.000Z

    Geochemical signatures in the otoliths of diadromous fishes may allow for retrospective analyses of natal origins. In an assessment of river-specific signatures in American shad (Alosa sapidissima), an anadromous clupeid ...

  5. Geochemical heterogeneity in the Hawaiian plume : constraints from Hawaiian volcanoes and Emperor seamounts

    E-Print Network [OSTI]

    Huang, Shichun

    2005-01-01T23:59:59.000Z

    The 6000-km long, age-progressive linear Hawaii-Emperor Chain is one of the best defined hotspot tracks. This hotspot track plays an important role in the plume hypothesis. In this research, geochemical data on the ...

  6. Up-Scaling Geochemical Reaction Rates Accompanying Acidic CO2-Saturated Brine Flow in Sandstone Aquifers

    E-Print Network [OSTI]

    New York at Stoney Brook, State University of

    1 Up-Scaling Geochemical Reaction Rates Accompanying Acidic CO2-Saturated Brine Flow in Sandstone models. As a step toward this, network flow models were used to simulate the flow of CO2-saturated brine

  7. A Geological and Hydro-Geochemical Study of the Animas Geothermal...

    Open Energy Info (EERE)

    Hydro-Geochemical Study of the Animas Geothermal Area, Hidalgo County, New Mexico Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: A Geological...

  8. The dynamics of oceanic transform faults : constraints from geophysical, geochemical, and geodynamical modeling

    E-Print Network [OSTI]

    Gregg, Patricia Michelle Marie

    2008-01-01T23:59:59.000Z

    Segmentation and crustal accretion at oceanic transform fault systems are investigated through a combination of geophysical data analysis and geodynamical and geochemical modeling. Chapter 1 examines the effect of fault ...

  9. Geochemical Behaviour of S, Cl and Fe in Silicate Melts/Glasses...

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

    Geochemical Behaviour of S, Cl and Fe in Silicate MeltsGlasses Simulating Natural Magmas Monday, March 26, 2012 - 11:00am SSRL Conference Room 137-322 G. Giuli, R. Alonso-Mori, E....

  10. Geochemical evidence for possible natural migration of Marcellus Formation brine to

    E-Print Network [OSTI]

    Geochemical evidence for possible natural migration of Marcellus Formation brine to shallow possible migration of Marcellus brine through naturally occurring pathways. The occurrences of saline water, because of natural hydraulic connections to deeper formations. formation water isotopes Marcellus Shale

  11. 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

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

    E-Print Network [OSTI]

    effective spin temperatures of Æ50 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

  13. MINTEQ2 geochemical code: provisionary organic data base

    SciTech Connect (OSTI)

    Morrey, J.R.; Krupka, K.M.; Dove, F.H.

    1985-10-01T23:59:59.000Z

    Organic components in aqueous radioactive chemical sources, surface waters, and ground waters could substantially alter the mobility of radioactive and other important nonradioactive elements released from a defense waste disposal system. It is therefore important to be able to predict, as accurately as possible, the effects of selected organic components on the solubilities of radionuclides and important nonradioactive elements. The geochemical code MINTEQ2 can be used to assess solubilities provided that appropriate thermochemical data for organic and inorganic aqueous species and solids are available for its use. The code accepts an assemblage of gaseous and solid phases in contact with an aqueous phase and calculates the thermochemical equilibrium between these phases. Unlike typical hydrologic flow and transport codes where the data base is entirely site specific (i.e., parameters particular to the specific site), MINTEQ2 requires an additional generic thermochemical data base. This report discusses the addition of provisionary organic reactions and associated equilibrium constants to the generic data base that can be used by MINTEQ2 in scoping calculations or preliminary performance assessments.

  14. Microbiological and geochemical characterization of fluvially deposited sulfidic mine tailings

    SciTech Connect (OSTI)

    Wielinga, B.; Lucy, J.K.; Moore, J.N.; Seastone, O.F.; Gannon, J.E. [Univ. of Montana, Missoula, MT (United States)

    1999-04-01T23:59:59.000Z

    The fluvial deposition of mine tailings generated from historic mining operations near Butte, Montana, has resulted in substantial surface and shallow groundwater contamination along Silver Bow Creek. Biogeochemical processes in the sediment and underlying hyporheic zone were studied in an attempt to characterize interactions consequential to heavy-metal contamination of shallow groundwater. Sediment cores were extracted and fractionated based on sediment stratification. Subsamples of each fraction were assayed for culturable heterotrophic microbiota, specific microbial guilds involved in metal redox transformations, and both aqueous- and solid-phase geochemistry. Populations of cultivable Fe(III)-reducing bacteria were most prominent in the anoxic, circumneutral pH regions associated with a ferricrete layer or in an oxic zone high in organic carbon and soluble iron. Sulfur- and iron-oxidizing bacteria were distributed in discrete zones throughout the tailings and were often recovered from sections at and below the anoxic groundwater interface. Sulfate-reducing bacteria were also widely distributed in the cores and often occurred in zones overlapping iron and sulfur oxidizers. Sulfate-reducing bacteria were consistently recovered from oxic zones that contained high concentrations of metals in the oxidizable fraction. Altogether, these results suggest a highly varied and complex microbial ecology within a very heterogeneous geochemical environment. Such physical and biological heterogeneity has often been overlooked when remediation strategies for metal contaminated environments are formulated.

  15. 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

  16. 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.

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. 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

  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. TOUGHREACT User's Guide: A Simulation Program for Non-isothermal Multiphase Reactive geochemical Transport in Variable Saturated Geologic Media

    SciTech Connect (OSTI)

    Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

    2004-05-24T23:59:59.000Z

    Coupled modeling of subsurface multiphase fluid and heat flow, solute transport and chemical reactions can be used for the assessment of mineral alteration in hydrothermal systems, waste disposal sites, acid mine drainage remediation, contaminant transport, and groundwater quality. A comprehensive non-isothermal multi-component reactive fluid flow and geochemical transport simulator, TOUGHREACT, has been developed. A wide range of subsurface thermo-physical-chemical processes is considered under various thermohydrological and geochemical conditions of pressure, temperature, water saturation, and ionic strength. The program can be applied to one-, two- or three-dimensional porous and fractured media with physical and chemical heterogeneity. The model can accommodate any number of chemical species present in liquid, gas and solid phases. A variety of equilibrium chemical reactions are considered, such as aqueous complexation, gas dissolution/exsolution, and cation exchange. Mineral dissolution/precipitation can proceed either subject to local equilibrium or kinetic conditions. Changes in porosity and permeability due to mineral dissolution and precipitation can be considered. Linear adsorption and decay can be included. For the purpose of future extensions, surface complexation by double layer model is coded in the program. Xu and Pruess (1998) developed a first version of a non-isothermal reactive geochemical transport model, TOUGHREACT, by introducing reactive geochemistry into the framework of the existing multi-phase fluid and heat flow code TOUGH2 (Pruess, 1991). Xu, Pruess, and their colleagues have applied the program to a variety of problems such as: (1) supergene copper enrichment (Xu et al, 2001), (2) caprock mineral alteration in a hydrothermal system (Xu and Pruess, 2001a), and (3) mineral trapping for CO{sub 2} disposal in deep saline aquifers (Xu et al, 2003b and 2004a). For modeling the coupled thermal, hydrological, and chemical processes during heater tests at proposed nuclear waste disposal site at Yucca Mountain (Nevada), Sonnenthal and Spycher (2000) and Spycher et al. (2003) enhanced TOUGHREACT on (1) high temperature geochemistry, (2) mineral reactive surface area calculations, and (3) porosity and permeability changes due to mineral alteration. On the other hand, Pruess et al. (1999) updated the TOUGH2 simulator to TOUGH2 V2. The present version of TOUGHREACT was developed by introducing the work of Sonnenthal and Spycher (2000) to the original work of Xu and Pruess (1998), and by replacing TOUGH2 (Pruess, 1991) by TOUGH2 V2 (Pruess et al, 1999). The TOUGHREACT program makes use of ''self-documenting'' features. It is distributed with a number of input data files for sample problems. Besides providing benchmarks for proper code installation, these can serve as self-teaching tutorial in the use of TOUGHREACT, and they provide templates to help jump-start new applications. The fluid and heat flow part of TOUGHREACT is derived from TOUGH2 V2, so in addition to the current manual, users must have manual of the TOUGH2 V2 (Pruess et al., 1999). The present version of TOUGHREACT provides the following different TOUGH2 fluid property or ''EOS'' (equation-of-state) modules: (1) EOS1 for water, or two waters with typical applications to hydrothermal problems, (2) EOS2 for multiphase mixtures of water and CO{sub 2} also with typical applications to hydrothermal problems, (3) EOS3 for multiphase mixtures of water and air with typical applications to vadose zone and nuclear waste disposal problems, (4) EOS4 that has the same capabilities as EOS3 but with vapor pressure lowering effects due to capillary pressure, (5) EOS9 for single phase water (Richards. equation) with typical applications to ambient reactive geochemical transport problems, (6) ECO2 for multiphase mixtures of water, CO{sub 2} and NaCl with typical applications to CO{sub 2} disposal in deep brine aquifers.

  9. GEOCHEMICAL MODELING OF F AREA SEEPAGE BASIN COMPOSITION AND VARIABILITY

    SciTech Connect (OSTI)

    Millings, M.; Denham, M.; Looney, B.

    2012-05-08T23:59:59.000Z

    From the 1950s through 1989, the F Area Seepage Basins at the Savannah River Site (SRS) received low level radioactive wastes resulting from processing nuclear materials. Discharges of process wastes to the F Area Seepage Basins followed by subsequent mixing processes within the basins and eventual infiltration into the subsurface resulted in contamination of the underlying vadose zone and downgradient groundwater. For simulating contaminant behavior and subsurface transport, a quantitative understanding of the interrelated discharge-mixing-infiltration system along with the resulting chemistry of fluids entering the subsurface is needed. An example of this need emerged as the F Area Seepage Basins was selected as a key case study demonstration site for the Advanced Simulation Capability for Environmental Management (ASCEM) Program. This modeling evaluation explored the importance of the wide variability in bulk wastewater chemistry as it propagated through the basins. The results are intended to generally improve and refine the conceptualization of infiltration of chemical wastes from seepage basins receiving variable waste streams and to specifically support the ASCEM case study model for the F Area Seepage Basins. Specific goals of this work included: (1) develop a technically-based 'charge-balanced' nominal source term chemistry for water infiltrating into the subsurface during basin operations, (2) estimate the nature of short term and long term variability in infiltrating water to support scenario development for uncertainty quantification (i.e., UQ analysis), (3) identify key geochemical factors that control overall basin water chemistry and the projected variability/stability, and (4) link wastewater chemistry to the subsurface based on monitoring well data. Results from this study provide data and understanding that can be used in further modeling efforts of the F Area groundwater plume. As identified in this study, key geochemical factors affecting basin chemistry and variability included: (1) the nature or chemistry of the waste streams, (2) the open system of the basins, and (3) duration of discharge of the waste stream types. Mixing models of the archetype waste streams indicated that the overall basin system would likely remain acidic much of the time. Only an extended periods of predominantly alkaline waste discharge (e.g., >70% alkaline waste) would dramatically alter the average pH of wastewater entering the basins. Short term and long term variability were evaluated by performing multiple stepwise modeling runs to calculate the oscillation of bulk chemistry in the basins in response to short term variations in waste stream chemistry. Short term (1/2 month and 1 month) oscillations in the waste stream types only affected the chemistry in Basin 1; little variation was observed in Basin 2 and 3. As the largest basin, Basin 3 is considered the primary source to the groundwater. Modeling showed that the fluctuation in chemistry of the waste streams is not directly representative of the source term to the groundwater (i.e. Basin 3). The sequence of receiving basins and the large volume of water in Basin 3 'smooth' or nullify the short term variability in waste stream composition. As part of this study, a technically-based 'charge-balanced' nominal source term chemistry was developed for Basin 3 for a narrow range of pH (2.7 to 3.4). An example is also provided of how these data could be used to quantify uncertainty over the long term variations in waste stream chemistry and hence, Basin 3 chemistry.

  10. Origin and geochemical evolution of the Michigan basin brine

    SciTech Connect (OSTI)

    Wilson, T.P.

    1989-01-01T23:59:59.000Z

    Chemical and isotopic data were collected on 126 oil field brine samples and were used to investigate the origin and geochemical evolution of water in 8 geologic formations in the Michigan basin. Two groups of brine are found in the basin, the Na-Ca-Cl brine in the upper Devonian formations, and Ca-Na-Cl brine from the lower Devonian and Silurian aged formations. Water in the upper Devonian Berea, Traverse, and Dundee formations originated from seawater concentrated into halite facies. This brine evolved by halite precipitation, dolomitization, aluminosilicate reactions, and the removal of SO{sub 4} by bacterial action or by CaSO{sub 4} precipitation. The stable isotopic composition (D, O) is thought to represent dilution of evapo-concentrated seawater by meteoric water. Water in the lower Devonian Richfield, Detroit River Group, and Niagara-Salina formations is very saline Ca-Na-Cl brine. Cl/Br suggest it originated from seawater concentrated through the halite and into the MgSO{sub 4} salt facies, with an origin linked to the Silurian and Devonian salt deposits. Dolomitization and halite precipitation increased the Ca/Na, aluminosilicate reactions removed K, and bacterial action or CaSO{sub 4} precipitation removed SO{sub 4} from this brine. Water chemistry in the Ordovician Trenton-Black River formations indicates dilution of evapo-concentrated seawater by fresh or seawater. Possible saline end-members include Ordovician seawater, present-day upper Devonian brine, or Ca-Cl brine from the deeper areas in the basin.

  11. Factors Controlling The Geochemical Evolution Of Fumarolic Encrustatio...

    Open Energy Info (EERE)

    the fumarolic deposits. High-temperature gasesliquids heavily altered the ejecta glass and mineral phases adjacent to the fumarolic conduit. As the fumaroles cooled. Fe-rich...

  12. Geochemical evidence for the hydrology of a Tamarack-peat bog, Brimfield Township, Portage County, Ohio

    SciTech Connect (OSTI)

    Wilson, T.P.; Miller, L.A. (Kent State Univ., OH (United States). Dept. of Geology and Water Resources)

    1992-01-01T23:59:59.000Z

    Peat Bogs and wetlands represent unique environmental settings what are increasingly subjected to anthropogenic stresses involving inputs of water and chemicals. This study used geochemical and hydrologic monitoring to determine the inputs and fates of elements of the Kent-Brimfield bog located in Portage County, Ohio. Based on physical and chemical information collected over one year, a model is proposed here describing the hydrologic connection between a bog and shallow ground water surrounding the bog. The chemical composition of precipitation, soil water and ground water in the bog vicinity were monitored for one year. Field measurements included water levels, pH, Eh, alkalinity and temperature. Trace metal content of the peat, the pore waters, soil water and ground waters were determined by GFAA, ICP and LIC methods. This bog was found to function as part of a perched water table aquifer. Water in the upper 3 m of the bog is found to be chemically similar to precipitation, but modified by reactions involving dissolution of mineral matter and biologic processes. The chemistry of water deeper in the bog (> 3m) resembles shallow ground water surrounding the bog, modified by weathering of underlying geologic materials and sulfate reduction. This similarity, along with ground water elevations within and outside of the bog, supports that shallow ground water interacts with, and helps maintain water levels in the upper surface of the bog. From these results, a model is proposed for the seasonal variations in hydrologic processes operating in the wetland and surrounding basin, and describes how wetlands may change seasonally from being influent to effluent systems.

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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.

  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. 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.

  1. Elucidating geochemical response of shallow heterogeneous aquifers to CO2 leakage using high-performance computing: Implications for monitoring of CO2 sequestration

    SciTech Connect (OSTI)

    Navarre-Sitchler, Alexis K.; Maxwell, Reed M.; Siirila, Erica R.; Hammond, Glenn E.; Lichtner, Peter C.

    2013-03-01T23:59:59.000Z

    Predicting and quantifying impacts of potential carbon dioxide (CO2) leakage into shallow aquifers that overlie geologic CO2 storage formations is an important part of developing reliable carbon storage techniques. Leakage of CO2 through fractures, faults or faulty wellbores can reduce groundwater pH, inducing geochemical reactions that release solutes into the groundwater and pose a risk of degrading groundwater quality. In order to help quantify this risk, predictions of metal concentrations are needed during geologic storage of CO2. Here, we present regional-scale reactive transport simulations, at relatively fine-scale, of CO2 leakage into shallow aquifers run on the PFLOTRAN platform using high-performance computing. Multiple realizations of heterogeneous permeability distributions were generated using standard geostatistical methods. Increased statistical anisotropy of the permeability field resulted in more lateral and vertical spreading of the plume of impacted water, leading to increased Pb2+ (lead) concentrations and lower pH at a well down gradient of the CO2 leak. Pb2+ concentrations were higher in simulations where calcite was the source of Pb2+ compared to galena. The low solubility of galena effectively buffered the Pb2+ concentrations as galena reached saturation under reducing conditions along the flow path. In all cases, Pb2+ concentrations remained below the maximum contaminant level set by the EPA. Results from this study, compared to natural variability observed in aquifers, suggest that bicarbonate (HCO3) concentrations may be a better geochemical indicator of a CO2 leak under the conditions simulated here.

  2. Soil Iodine Determination in Deccan Syneclise, India: Implications for Near Surface Geochemical Hydrocarbon Prospecting

    SciTech Connect (OSTI)

    Mani, Devleena, E-mail: devleenatiwari@ngri.res.in [National Geophysical Research Institute (Council of Scientific and Industrial Research) (India); Kumar, T. Satish [Oil India Limited (India); Rasheed, M. A.; Patil, D. J.; Dayal, A. M.; Rao, T. Gnaneshwar; Balaram, V. [National Geophysical Research Institute (Council of Scientific and Industrial Research) (India)

    2011-03-15T23:59:59.000Z

    The association of iodine with organic matter in sedimentary basins is well documented. High iodine concentration in soils overlying oil and gas fields and areas with hydrocarbon microseepage has been observed and used as a geochemical exploratory tool for hydrocarbons in a few studies. In this study, we measure iodine concentration in soil samples collected from parts of Deccan Syneclise in the west central India to investigate its potential application as a geochemical indicator for hydrocarbons. The Deccan Syneclise consists of rifted depositional sites with Gondwana-Mesozoic sediments up to 3.5 km concealed under the Deccan Traps and is considered prospective for hydrocarbons. The concentration of iodine in soil samples is determined using ICP-MS and the values range between 1.1 and 19.3 ppm. High iodine values are characteristic of the northern part of the sampled region. The total organic carbon (TOC) content of the soil samples range between 0.1 and 1.3%. The TOC correlates poorly with the soil iodine (r{sup 2} < 1), indicating a lack of association of iodine with the surficial organic matter and the possibility of interaction between the seeping hydrocarbons and soil iodine. Further, the distribution pattern of iodine compares well with two surface geochemical indicators: the adsorbed light gaseous hydrocarbons (methane through butane) and the propane-oxidizing bacterial populations in the soil. The integration of geochemical observations show the occurrence of elevated values in the northern part of the study area, which is also coincident with the presence of exposed dyke swarms that probably serve as conduits for hydrocarbon microseepage. The corroboration of iodine with existing geological, geophysical, and geochemical data suggests its efficacy as one of the potential tool in surface geochemical exploration of hydrocarbons. Our study supports Deccan Syneclise to be promising in terms of its hydrocarbon prospects.

  3. Geochemical relationships of petroleum in Mesozoic reservoirs to carbonate source rocks of Jurassic Smackover Formation, southwestern Alabama

    SciTech Connect (OSTI)

    Claypool, G.E.; Mancini, E.A.

    1989-07-01T23:59:59.000Z

    Algal carbonate mudstones of the Jurassic Smackover Formation are the main source rocks for oil and condensate in Mesozoic reservoir rocks in southwestern Alabama. This interpretation is based on geochemical analyses of oils, condensates, and organic matter in selected samples of shale (Norphlet Formation, Haynesville Formation, Trinity Group, Tuscaloosa Group) and carbonate (Smackover Formation) rocks. Potential and probable oil source rocks are present in the Tuscaloosa Group and Smackover Formation, respectively. Extractable organic matter from Smackover carbonates has molecular and isotopic similarities to Jurassic oil. Although the Jurassic oils and condensates in southwestern Alabama have genetic similarities, they show significant compositional variations due to differences in thermal maturity and organic facies/lithofacies. Organic facies reflect different depositional conditions for source rocks in the various basins. The Mississippi Interior Salt basin was characterized by more continuous marine to hypersaline conditions, whereas the Manila and Conecuh embayments periodically had lower salnity and greater input of clastic debris and terrestrial organic matter. Petroleum and organic matter in Jurassic rocks of southwestern Alabama show a range of thermal transformations. The gas content of hydrocarbons in reservoirs increases with increasing depth and temperature. In some reservoirs where the temperature is above 266/degrees/F(130/degrees/C), gas-condensate is enriched in isotopically heavy sulfur, apparently derived from thermochemical reduction of Jurassic evaporite sulfate. This process also resulted in increase H/sub 2/S and CO in the gas, and depletion of saturated hydrocarbons in the condensate liquids.

  4. 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...

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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...

  12. 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.

  13. 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...

  14. 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...

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. APPROXIMATE INVERSE PRECONDITIONING FOR THE CONJUGATE GRADIENT METHOD

    E-Print Network [OSTI]

    Tùma, 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

  5. Temperatures in ambient mantle and plumes: Constraints from basalts, picrites, and komatiites

    E-Print Network [OSTI]

    below oceanic ridges, islands, and plateaus, on the basis of the petrology and geochemistry of erupted plumes; ambient mantle temperatures; petrology; mid ocean ridge basalt. Index Terms: 3610 Mineralogy and Petrology: Geochemical modeling (1009, 8410); 3619 Mineralogy and Petrology: Magma genesis and partial

  6. Temperature and Microbial Activity Effects on Trace Element Leaching from Metalliferous Peats

    E-Print Network [OSTI]

    Walter, M.Todd

    Temperature and Microbial Activity Effects on Trace Element Leaching from Metalliferous PeatsDue to geochemical processes, peat soils often have elevated con- sulfides (Cannon, 1955). The maximum Zn concentra as high as 10 g kg 1 . Theperatures to vary microbial activity in two metalliferous peats (M7 acidic peat

  7. 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

  8. Geochemical Evidence for an Eolian Sand Dam across the North and South Platte Rivers in Nebraska

    E-Print Network [OSTI]

    Loope, David B.

    Geochemical Evidence for an Eolian Sand Dam across the North and South Platte Rivers in Nebraska that the Nebraska Sand Hills once migrated across the North and South Platte rivers and dammed the largest tributary of the South Platte River, have compositions intermediate between the Nebraska Sand Hills (quartz

  9. AESRC 2012, Kingston March 23-25th THE "SURFACE" EXPRESSION: WHAT DO GEOCHEMICAL ANOMALIES IN

    E-Print Network [OSTI]

    IN SURFACE MEDIA AND SHALLOW SANDSTONES OVERLYING THE PHOENIX URANIUM DEPOSIT, ATHABASCA BASIN, SASKATCHEWAN to examine whether surficial geochemical anomalies exist for such a deeply buried uranium deposit. For our expression in surface media provides excellent exploration tools for deeply seated unconformity

  10. Geochemical composition and provenance discrimination of coastal sediments around Cheju Island in the southeastern Yellow Sea

    E-Print Network [OSTI]

    Yang, Shouye

    in the southeastern Yellow Sea S.Y. Yanga,b,*, D.I. Lima , H.S. Junga , B.C. Ohc a Marine Environment and Climate Change Laboratory, Korea Ocean Research and Development Institute, Ansan P.O. Box 29, Seoul 425) compositions and geochemical discrimination diagrams were revealed to be useful indices for identifying

  11. A GEOCHEMICAL MODULE FOR "AMDTreat" TO COMPUTE CAUSTIC QUANTITY, EFFLUENT QUALITY, AND SLUDGE VOLUME1

    E-Print Network [OSTI]

    of sludge produced by the treatment, a titration simulation is being developed using the geochemical program The AMDTreat computer program ( . Treatment with caustic chemicals typically is used to increase pH (6 to 8), whereas active manganese removal requires treatment to alkaline pH (~10). The treatment

  12. Measuring prehistoric mobility strategies based on obsidian geochemical and technological signatures in the Owens Valley, California

    E-Print Network [OSTI]

    Measuring prehistoric mobility strategies based on obsidian geochemical and technological; Lithic technology; LA-ICP-MS; Mobility strategies; Owens Valley 1. Introduction Obsidian studies compare the organization of obsidian flaked stone technologies in two different time periods at CA-INY-30

  13. Organic geochemical evidence for pine tar production in middle Eastern Sweden during the Roman Iron Age

    E-Print Network [OSTI]

    Organic geochemical evidence for pine tar production in middle Eastern Sweden during the Roman Iron samples were analysed for diterpenoids derived from abietic acid (mainly retene, abietic acid, dehydroa- bietic acid and methyl dehydroabietate) by Gas Chromatography-Mass Spectrometry (GC-MS) in order to test

  14. Geochemical assessment of nuclear waste isolation. Report of activities during fiscal year 1982

    SciTech Connect (OSTI)

    Not Available

    1983-07-01T23:59:59.000Z

    The status of the following investigations is reported: canister/overpack-backfill chemical interactions and mechanisms; backfill and near-field host rock chemical interactions mechanisms; far-field host rock geochemical interactions; verification and improvement of predictive algorithms for radionuclide migration; and geologic systems as analogues for long-term radioactive waste isolation.

  15. Assessing XRF for the geochemical characterization of radiolarian chert artifacts from northeastern North America

    E-Print Network [OSTI]

    Long, Bernard

    Assessing XRF for the geochemical characterization of radiolarian chert artifacts from northeastern 2012 Keywords: Chert XRF Geochemistry Non-destructive Weathering Quarries Quebec a b s t r a c-ray fluorescence (ED-XRF) as a first-order technique to determine chert whole-rock geochemistry for archaeological

  16. Paper #194973 GEOCHEMICAL CHARACTERIZATION OF THE RESERVOIR HOSTING SHALE-GAS AND OIL in

    E-Print Network [OSTI]

    Paper #194973 GEOCHEMICAL CHARACTERIZATION OF THE RESERVOIR HOSTING SHALE-GAS AND OIL a reservoir for shale-gas and oil. We examined organic-rich black shale, known as Macasty shale, of Upper SHALE-GAS AND OIL in THE SUBSURFACE OF ANTICOSTI ISLAND, CANADA Key Words: Provenance, Anticosti Island

  17. 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 $\

  18. A geochemical, petrological, and geophysical case study of Caryn Seamount

    E-Print Network [OSTI]

    Drew, Fred Prescott

    1975-01-01T23:59:59.000Z

    . There is a wealth of information to be obtained from seamount magnetization data, but to date only 20-30 mag- netization determinations have been published (Grossling, 1969). Since Caryn Seamount is volcanic in origin the rock samples are markers... and the specific volume data for water at liquidus temperatures and water pressures at those depths, it is calculated that the rocks with 30% vesicles contained 2. 4% magmatic water and the rocks with 16% vesicles contained 1. 9% magmatic water, assuming...

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. Geochemical and isotopic results for groundwater, drainage waters, snowmelt, permafrost, precipitation in Barrow, Alaska (USA) 2012-2013

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

    Wilson, Cathy; Newman, Brent; Heikoop, Jeff

    Data include a large suite of analytes (geochemical and isotopic) for samples collected in Barrow, Alaska (2012-2013). Sample types are indicated, and include soil pore waters, drainage waters, snowmelt, precipitation, and permafrost samples.

  5. Origin of geochemical heterogeneity in the mantle : constraints from volcanism associated with Hawaiian and Kerguelen mantle plumes

    E-Print Network [OSTI]

    Xu, Guangping

    2007-01-01T23:59:59.000Z

    Lavas derived from long-lived mantle plumes provide important information of mantle compositions and the processes that created the geochemical heterogeneity within the mantle. Kerguelen and Hawaii are two long-lived mantle ...

  6. Geochemical factors affecting radionuclide transport through near and far fields at a Low-Level Waste Disposal Site

    SciTech Connect (OSTI)

    Kaplan, D.I.; Seme, R.J. [Pacific Northwest Lab., Richland, WA (United States); Piepkho, M.G. [Westinghouse Hanford Co., Richland, WA (United States)

    1995-03-01T23:59:59.000Z

    The concentration of low-level waste (LLW) contaminants in groundwater is determined by the amount of contaminant present in the solid waste, rate of release from the waste and surrounding barriers, and a number of geochemical processes including adsorption, desorption, diffusion, precipitation, and dissolution. To accurately predict radionuclide transport through the subsurface, it is essential that the important geochemical processes affecting radionuclide transport be identified and, perhaps more importantly, accurately quantified and described in a mathematically defensible manner.

  7. 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.

  8. 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.

  9. 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,...

  10. 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)

  11. 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...

  12. 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...

  13. 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

  14. 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 × ...

  15. 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 ...

  16. 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 ...

  17. 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*** ...

  18. 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 ...

  19. 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 ...

  20. 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 ...

  1. 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.

  2. 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

  3. 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 -...

  4. 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...

  5. 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...

  6. 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)

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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.

  13. Geochemical evolution of highly alkaline and saline tank wasteplumes during seepage through vadose zone sediments

    SciTech Connect (OSTI)

    Wan, Jiamin; Tokunaga, Tetsu K.; Larsen, Joern T.; Serne, R. Jeff

    2002-12-01T23:59:59.000Z

    Leakage of highly saline and alkaline radioactive waste from storage tanks into underlying sediments is a serious environmental problem at the Hanford Site in Washington State. This study focuses on geochemical evolution of tank waste plumes resulting from interactions between the waste solution and sediment. A synthetic tank waste solution was infused into unsaturated Hanford sediment columns (0.2, 0.6, and 2 m )maintained at 70 C to simulate the field contamination process. Spatially and temporally resolved geochemical profiles of the waste plume were obtained. Thorough OH- neutralization (from an initial pH 14 down to 6.3) was observed. Three broad zones of pore solutions were identified to categorize the dominant geochemical reactions: the silicate dissolution zone (pH>10), pH-neutralized zone (pH 10 to 6.5), and displaced native sediment pore water (pH 6.5 to 8). Elevated concentrations of Si, Fe, and K in plume fluids and their depleted concentrations in plume sediments reflected dissolution of primary minerals within the silicate dissolution zone. The very high Na concentrations in the waste solution resulted in rapid and complete cation exchange, reflected in high concentrations of Ca and Mg at the plume front. The plume-sediment profiles also showed deposition of hydrated solids and carbonates. Fair correspondence was obtained between these results and analyses of field borehole samples from a waste plume at the Hanford Site. Results of this study provide a well-defined framework for understanding waste plumes in the more complex field setting and for understanding geochemical factors controlling transport of contaminant species carried in waste solutions that leaked from single-shell storage tanks in the past.

  14. Geochemical evolution of highly alkaline and saline tank waste plumes during seepage through vadose zone sediments

    SciTech Connect (OSTI)

    Wan, Jiamin; Tokunaga, Tetsu K.; Larsen, Joern T.; Serne, R JEFFREY.

    2004-02-01T23:59:59.000Z

    Leakage of highly saline and alkaline radioactive waste from storage tanks into underlying sediments is a serious environmental problem at the Hanford Site in Washington State. This study focuses on geochemical evolution of tank waste plumes resulting from interactions between the waste solution and sediment. A synthetic tank waste solution was infused into unsaturated Hanford sediment columns (0.2, 0.6, and 2 m) maintained at 70C to simulate the field contamination process. Spatially and temporally resolved geochemical profiles of the waste plume were obtained. Thorough OH neutralization (from an initial pH 14 down to 6.3) was observed. Three broad zones of pore solutions were identified to categorize the dominant geochemical reactions: the silicate dissolution zone (pH > 10), pH-neutralized zone (pH 10 to 6.5), and displaced native sediment pore water (pH 6.5 to 8). Elevated concentrations of Si, Fe, and K in plume fluids and their depleted concentrations in plume sediments reflected dissolution of primary minerals within the silicate dissolution zone. The very high Na concentrations in the waste solution resulted in rapid and complete cation exchange, reflected in high concentrations of Ca and Mg at the plume front. The plume-sediment profiles also showed deposition of hydrated solids and carbonates. Fair correspondence was obtained between these results and analyses of field borehole samples from a waste plume at the Hanford Site. Results of this study provide a well-defined framework for understanding waste plumes in the more complex field setting and for understanding geochemical factors controlling transport of contaminant species carried in waste solutions that leaked from single-shell storage tanks in the past.

  15. Kinetics of Uranium(VI) Desorption from Contaminated Sediments: Effect of Geochemical Conditions and Model Evaluation

    SciTech Connect (OSTI)

    Liu, Chongxuan; Shi, Zhenqing; Zachara, John M.

    2009-09-01T23:59:59.000Z

    Stirred-flow cell experiments were performed to investigate the kinetics of uranyl [U(VI)] desorption from a contaminated sediment collected from the Hanford 300 Area at the US Department of Energy (DOE) Hanford Site, Washington. Three influent solutions of variable pH, Ca and carbonate concentrations that affected U(VI) aqueous and surface speciation were used under dynamic flow conditions to evaluate the effect of geochemical conditions on the rate of U(VI) desorption. The measured rate of U(VI) desorption varied with solution chemical composition that evolved as a result of thermodynamic and kinetic interactions between the influent solutions and sediment. The solution chemical composition that led to a lower equilibrium U(VI) sorption to the solid phase yielded a faster desorption rate. The experimental results were used to evaluate a multi-rate, surface complexation model (SCM) that has been proposed to describe U(VI) desorption kinetics in the Hanford sediment that contained complex sorbed U(VI) species in mass transfer limited domains. The model was modified and supplemented by including multi-rate, ion exchange reactions to describe the geochemical interactions between the solutions and sediment. With the same set of model parameters, the modified model reasonably well described the evolution of major ions and the rates of U(VI) desorption under variable geochemical and flow conditions, implying that the multi-rate SCM is an effective way to describe U(VI) desorption kinetics in subsurface sediments.

  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. Geochemical Data Package for Performance Assessment Calculations Related to the Savannah River Site

    SciTech Connect (OSTI)

    Kaplan, D

    2006-02-28T23:59:59.000Z

    The Savannah River Site disposes of certain types of radioactive waste within subsurface-engineered facilities. One of the tools used to establish the capacity of a given site to safely store radioactive waste (i.e., that a site does not exceed its Waste Acceptance Criteria) is the Performance Assessment (PA). The objective of this document is to provide the geochemical values for the PA calculations. This work is being conducted as part of the on-going maintenance program that permits the PA to periodically update existing calculations when new data becomes available. Because application of values without full understanding of their original purpose may lead to misuse, this document also provides the geochemical conceptual model, approach used for selecting the values, the justification for selecting data, and the assumptions made to assure that the conceptual and numerical geochemical models are reasonably conservative (i.e., reflect conditions that will tend to predict the maximum risk to the hypothetical recipient). The geochemical parameters describe transport processes for 38 elements (>90 radioisotopes) potentially occurring within eight disposal units (Slit Trenches, Engineered Trenches, Low Activity Waste (LAW) Vault, Intermediate Level (ILV) Vaults, TRU-Pad-1, Naval Reactor Waste Pads, Components-in-Grout Trenches, and Saltstone Facility). This work builds upon well-documented work from previous PA calculations (McDowell-Boyer et al. 2000). The new geochemical concepts introduced in this data package are: (1) In the past, solubility products were used only in a few conditions (element existing in a specific environmental setting). This has been expanded to >100 conditions. (2) Radionuclide chemistry in cementitious environments is described through the use of both the Kd and apparent solubility concentration limit. Furthermore, the solid phase is assumed to age during the assessment period (thousands of years), resulting in three main types of controlling solid phases, each possessing a unique set of radionuclide sorption parameters (Kd and solubility concentration limit). (3) A large amount of recent site-specific sorption research has been conducted since the last PA (McDowell-Boyer et al. 2000). These new data have replaced previous Kd values derived from literature values, thus reducing uncertainty and improving accuracy. Finally, because this document will be used by future PA calculations and external acceptance of the document will eventually be required, this document was extensively reviewed. The review process, including the internal review, site review, and external review process is described.

  19. 1992--1993 low-temperature geothermal assessment program, Colorada

    SciTech Connect (OSTI)

    Cappa, J.A.; Hemborg, H.T.

    1995-01-01T23:59:59.000Z

    Previous assessments of Colorado`s low-temperature geothermal resources were completed by the Colorado Geological Survey in 1920 and in the mid- to late-1970s. The purpose of the 1992--1993 low-temperature geothermal resource assessment is to update the earlier physical, geochemical, and utilization data and compile computerized databases of the location, chemistry, and general information of the low-temperature geothermal resources in Colorado. The main sources of the data included published data from the Colorado Geological Survey, the US Geological Survey WATSTOR database, and the files of the State Division of Water Resources. The staff of the Colorado Geological Survey in 1992 and 1993 visited most of the known geothermal sources that were recorded as having temperatures greater than 30{degrees}C. Physical measurements of the conductivity, pH, temperature, flow rate, and notes on the current geothermal source utilization were taken. Ten new geochemical analyses were completed on selected geothermal sites. The results of the compilation and field investigations are compiled into the four enclosed Quattro Pro 4 databases. For the purposes of this report a geothermal area is defined as a broad area, usually less than 3 sq mi in size, that may have several wells or springs. A geothermal site is an individual well or spring within a geothermal area. The 1992-1993 assessment reports that there are 93 geothermal areas in the Colorado, up from the 56 reported in 1978; there are 157 geothermal sites up from the 125 reported in 1978; and a total of 382 geochemical analyses are compiled, up from the 236 reported in 1978. Six geothermal areas are recommended for further investigation: Trimble Hot Springs, Orvis Hot Springs, an area southeast of Pagosa Springs, the eastern San Luis Valley, Rico and Dunton area, and Cottonwood Hot Springs.

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. GEOTECHNICAL/GEOCHEMICAL CHARACTERIZATION OF ADVANCED COAL PROCESS WASTE STREAMS

    SciTech Connect (OSTI)

    Edwin S. Olson; Charles J. Moretti

    1999-11-01T23:59:59.000Z

    Thirteen solid wastes, six coals and one unreacted sorbent produced from seven advanced coal utilization processes were characterized for task three of this project. The advanced processes from which samples were obtained included a gas-reburning sorbent injection process, a pressurized fluidized-bed coal combustion process, a coal-reburning process, a SO{sub x}, NO{sub x}, RO{sub x}, BOX process, an advanced flue desulfurization process, and an advanced coal cleaning process. The waste samples ranged from coarse materials, such as bottom ashes and spent bed materials, to fine materials such as fly ashes and cyclone ashes. Based on the results of the waste characterizations, an analysis of appropriate waste management practices for the advanced process wastes was done. The analysis indicated that using conventional waste management technology should be possible for disposal of all the advanced process wastes studied for task three. However, some wastes did possess properties that could present special problems for conventional waste management systems. Several task three wastes were self-hardening materials and one was self-heating. Self-hardening is caused by cementitious and pozzolanic reactions that occur when water is added to the waste. All of the self-hardening wastes setup slowly (in a matter of hours or days rather than minutes). Thus these wastes can still be handled with conventional management systems if care is taken not to allow them to setup in storage bins or transport vehicles. Waste self-heating is caused by the exothermic hydration of lime when the waste is mixed with conditioning water. If enough lime is present, the temperature of the waste will rise until steam is produced. It is recommended that self-heating wastes be conditioned in a controlled manner so that the heat will be safely dissipated before the material is transported to an ultimate disposal site. Waste utilization is important because an advanced process waste will not require ultimate disposal when it is put to use. Each task three waste was evaluated for utilization potential based on its physical properties, bulk chemical composition, and mineral composition. Only one of the thirteen materials studied might be suitable for use as a pozzolanic concrete additive. However, many wastes appeared to be suitable for other high-volume uses such as blasting grit, fine aggregate for asphalt concrete, road deicer, structural fill material, soil stabilization additives, waste stabilization additives, landfill cover material, and pavement base course construction.

  7. 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.

  8. 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

  9. 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

  10. Preliminary Drill Sites

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

    Lane, Michael

    Preliminary locations for intermediate depth temperature gradient holes and/or resource confirmation wells based on compilation of geological, geophysical and geochemical data prior to carrying out the DOE-funded reflection seismic survey.

  11. Preliminary Drill Sites

    SciTech Connect (OSTI)

    Lane, Michael

    2013-06-28T23:59:59.000Z

    Preliminary locations for intermediate depth temperature gradient holes and/or resource confirmation wells based on compilation of geological, geophysical and geochemical data prior to carrying out the DOE-funded reflection seismic survey.

  12. 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.

  13. 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.

  14. 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

  15. 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

  16. 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...

  17. 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...

  18. 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

  19. 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.

  20. 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...

  1. 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 ...

  2. 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...

  3. 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...

  4. 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

  5. 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

  6. 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 ...

  7. 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

  8. 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...

  9. 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...

  10. 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

  11. 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.

  12. Geochemical fluid characteristics and main achievements about tracer tests at Soultz-sous-Forts (France) 1 EC Contract SES6-CT-2003-502706

    E-Print Network [OSTI]

    Boyer, Edmond

    Geochemical fluid characteristics and main achievements about tracer tests at Soultz Related with Work Package WP1a (Short term fluid circulation tests) and WP1c (Data acquisition) GEOCHEMICAL FLUID CHARACTERISTICS AND MAIN ACHIEVEMENTS ABOUT TRACER TESTS AT SOULTZ-SOUS-FORÃ?TS (FRANCE

  13. Up-Scaling Geochemical Reaction Rates for Carbon Dioxide (CO2) in Deep Saline Aquifers

    SciTech Connect (OSTI)

    Lindquist, W Brent

    2009-03-03T23:59:59.000Z

    The overall goal of the project was to bridge the gap between our knowledge of small-scale geochemical reaction rates and reaction rates meaningful for modeling transport at core scales. The working hypothesis was that reaction rates, determined from laboratory measurements based upon reactions typically conducted in well mixed batch reactors using pulverized reactive media may be significantly changed in in situ porous media flow due to rock microstructure heterogeneity. Specifically we hypothesized that, generally, reactive mineral surfaces are not uniformly accessible to reactive fluids due to the random deposition of mineral grains and to the variation in flow rates within a pore network. Expected bulk reaction rates would therefore have to be correctly up-scaled to reflect such heterogeneity. The specific objective was to develop a computational tool that integrates existing measurement capabilities with pore-scale network models of fluid flow and reactive transport. The existing measurement capabilities to be integrated consisted of (a) pore space morphology, (b) rock mineralogy, and (c) geochemical reaction rates. The objective was accomplished by: (1) characterizing sedimentary sandstone rock morphology using X-ray computed microtomography, (2) mapping rock mineralogy using back-scattered electron microscopy (BSE), X-ray dispersive spectroscopy (EDX) and CMT, (3) characterizing pore-accessible reactive mineral surface area, and (4) creating network models to model acidic CO{sub 2} saturated brine injection into the sandstone rock samples.

  14. Geochemical Implications of CO2 Leakage Associated with Geologic Storage: A Review

    SciTech Connect (OSTI)

    Harvey, Omar R.; Qafoku, Nikolla; Cantrell, Kirk J.; Brown, Christopher F.

    2012-07-09T23:59:59.000Z

    Leakage from deep storage reservoirs is a major risk factor associated with geologic sequestration of carbon dioxide (CO2). Different scientific theories exist concerning the potential implications of such leakage for near-surface environments. The authors of this report reviewed the current literature on how CO2 leakage (from storage reservoirs) would likely impact the geochemistry of near surface environments such as potable water aquifers and the vadose zone. Experimental and modeling studies highlighted the potential for both beneficial (e.g., CO2 re sequestration or contaminant immobilization) and deleterious (e.g., contaminant mobilization) consequences of CO2 intrusion in these systems. Current knowledge gaps, including the role of CO2-induced changes in redox conditions, the influence of CO2 influx rate, gas composition, organic matter content and microorganisms are discussed in terms of their potential influence on pertinent geochemical processes and the potential for beneficial or deleterious outcomes. Geochemical modeling was used to systematically highlight why closing these knowledge gaps are pivotal. A framework for studying and assessing consequences associated with each factor is also presented in Section 5.6.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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

  20. Coupled Geochemical and Hydrological Processes Governing the Fate and Transport of Radionuclides and Toxic Metals Beneath the Hanford Tank Farms

    SciTech Connect (OSTI)

    Scott Fendorf; Phil Jardine

    2006-07-21T23:59:59.000Z

    The goal of this research was to provide an improved understanding and predictive capability of coupled hydrological and geochemical mechanisms that are responsible for the accelerated migration and immobilization of radionuclides and toxic metals in the badose zone beneath the Hanford Tank Farms.

  1. Age, geochemical and SrNdPb isotopic constraints for mantle source characteristics and petrogenesis of Teru Volcanics,

    E-Print Network [OSTI]

    Stern, Robert J.

    Age, geochemical and Sr­Nd­Pb isotopic constraints for mantle source characteristics and petrogenesis of Teru Volcanics, Northern Kohistan Terrane, Pakistan S.D. Khana,*, R.J. Sternb , M.I. Mantonb, University of Peshawar, Pakistan Accepted 21 April 2004 Available online 23 September 2004 Abstract

  2. Geological, geochemical, and geophysical survey of the geothermal resources at Hot Springs Bay Valley, Akutan Island, Alaska

    SciTech Connect (OSTI)

    Motyka, R.J.; Wescott, E.M.; Turner, D.L.; Swanson, S.E.; Romick, J.D.; Moorman, M.A.; Poreda, R.J.; Witte, W.; Petzinger, B.; Allely, R.D.

    1985-01-01T23:59:59.000Z

    An extensive survey was conducted of the geothermal resource potential of Hot Springs Bay Valley on Akutan Island. A topographic base map was constructed, geologic mapping, geophysical and geochemical surveys were conducted, and the thermal waters and fumarolic gases were analyzed for major and minor element species and stable isotope composition. (ACR)

  3. Oxygen is a key element for biology and the cycling of geochemical elements, and has shaped the chemical

    E-Print Network [OSTI]

    Handy, Todd C.

    Oxygen is a key element for biology and the cycling of geochemical elements, and has shaped the chemical and biological evolution of Earth. The oceans appear to be loosing oxygen due to on-going climate change, with resulting impacts on marine ecosystems and global biogeochemical cycles. As oxygen levels

  4. Geochemical evidence of a near-surface history for source rocks of the central Coast Mountains Batholith, British Columbia

    E-Print Network [OSTI]

    Wetmore, Paul H.

    Geochemical evidence of a near-surface history for source rocks of the central Coast Mountains to ,50 Ma, indicate that the source regions for these rocks were relatively uniform and typical abundance of deep crustal or upper-mantle source rocks (DePaolo 1981; Kistler 1990; Chen and Tilton 1991; De

  5. Assessment of peat quality by molecular and bulk geochemical analysis: Application to the Holocene record of the Chautagne

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Assessment of peat quality by molecular and bulk geochemical analysis: Application to the Holocene in general from a limited variety of local plants, peat is however sensitive to physicochemical changes the information on peat quality provided by various families of biochemical components (lipids, lignin, sugars

  6. Numerical modeling of time-lapse seismic data from fractured reservoirs including fluid flow and geochemical processes 

    E-Print Network [OSTI]

    Shekhar, Ravi

    2009-05-15T23:59:59.000Z

    and amplitude variation with offset (AVO) results for our example model predicts that CO2 is easier to detect than brine in the fractured reservoirs. The effects of geochemical processes on seismics are simulated by time-lapse modeling for t = 1000 years. My...

  7. 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

  8. 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.

  9. 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

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

    E-Print Network [OSTI]

    Lin, Zhihong

    %, steady-state oscillations at $ 0:3 À 0:5 MHz (in the plasma frame), with azimuthal wave numbers m $ 14À16 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

  11. 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

  12. 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...

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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.

  2. TOUGHREACT User's Guide: A Simulation Program for Non-isothermal Multiphase Reactive Geochemical Transport in Variably Saturated Geologic Media, V1.2.1

    SciTech Connect (OSTI)

    Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

    2008-09-29T23:59:59.000Z

    Coupled modeling of subsurface multiphase fluid and heat flow, solute transport, and chemical reactions can be applied to many geologic systems and environmental problems, including geothermal systems, diagenetic and weathering processes, subsurface waste disposal, acid mine drainage remediation, contaminant transport, and groundwater quality. TOUGHREACT has been developed as a comprehensive non-isothermal multi-component reactive fluid flow and geochemical transport simulator to investigate these and other problems. A number of subsurface thermo-physical-chemical processes are considered under various thermohydrological and geochemical conditions of pressure, temperature, water saturation, and ionic strength. TOUGHREACT can be applied to one-, two- or three-dimensional porous and fractured media with physical and chemical heterogeneity. The code can accommodate any number of chemical species present in liquid, gas and solid phases. A variety of equilibrium chemical reactions are considered, such as aqueous complexation, gas dissolution/exsolution, and cation exchange. Mineral dissolution/precipitation can take place subject to either local equilibrium or kinetic controls, with coupling to changes in porosity and permeability and capillary pressure in unsaturated systems. Chemical components can also be treated by linear adsorption and radioactive decay. The first version of the non-isothermal reactive geochemical transport code TOUGHREACT was developed (Xu and Pruess, 1998) by introducing reactive geochemistry into the framework of the existing multi-phase fluid and heat flow code TOUGH2 (Pruess, 1991). TOUGHREACT was further enhanced with the addition of (1) treatment of mineral-water-gas reactive-transport under boiling conditions, (2) an improved HKF activity model for aqueous species, (3) gas species diffusion coefficients calculated as a function of pressure, temperature, and molecular properties, (4) mineral reactive surface area formulations for fractured and porous media, and (5) porosity, permeability, and capillary pressure changes owing to mineral precipitation/dissolution (Sonnenthal et al., 1998, 2000, 2001; Spycher et al., 2003a). Subsequently, TOUGH2 V2 was released with additional EOS modules and features (Pruess et al., 1999). The present version of TOUGHREACT includes all of the previous extensions to the original version, along with the replacement of the original TOUGH2 (Pruess, 1991) by TOUGH2 V2 (Pruess et al., 1999). TOUGHREACT has been applied to a wide variety of problems, some of which are included as examples, such as: (1) Supergene copper enrichment (Xu et al., 2001); (2) Mineral alteration in hydrothermal systems (Xu and Pruess, 2001a; Xu et al., 2004b; Dobson et al., 2004); (3) Mineral trapping for CO{sub 2} disposal in deep saline aquifers (Xu et al., 2003b and 2004a); (4) Coupled thermal, hydrological, and chemical processes in boiling unsaturated tuff for the proposed nuclear waste emplacement site at Yucca Mountain, Nevada (Sonnenthal et al., 1998, 2001; Sonnenthal and Spycher, 2000; Spycher et al., 2003a, b; Xu et al., 2001); (5) Modeling of mineral precipitation/dissolution in plug-flow and fracture-flow experiments under boiling conditions (Dobson et al., 2003); (6) Calcite precipitation in the vadose zone as a function of net infiltration (Xu et al., 2003); and (7) Stable isotope fractionation in unsaturated zone pore water and vapor (Singleton et al., 2004). The TOUGHREACT program makes use of 'self-documenting' features. It is distributed with a number of input data files for sample problems. Besides providing benchmarks for proper code installation, these can serve as a self-teaching tutorial in the use of TOUGHREACT, and they provide templates to help jump-start new applications. The fluid and heat flow part of TOUGHREACT is derived from TOUGH2 V2, so in addition to the current manual, users must have the manual of the TOUGH2 V2 (Pruess et al., 1999). The present version of TOUGHREACT provides the following TOUGH2 fluid property or 'EOS' (equation-of-state) modules: (1) EOS1 for

  3. Geochemical evidence for anoxic deep water in the Arabian Sea during the last glaciation

    SciTech Connect (OSTI)

    Sarkar, A.; Bhattacharya, S.K.; Sarin, M.M. (Physical Research Lab., Ahmedabad (India))

    1993-03-01T23:59:59.000Z

    Various paleoceanographic studies have indicated that the deep ocean was probably depleted in dissolved oxygen during the last glacial period ([approximately]18 kyr B.P.; [delta][sup 18]O, stage 2) compared to present time. However, direct evidence of low oxygen content in the deep waters has been lacking. Here, the authors report geochemical evidence of near anoxic conditions in the deep Arabian Sea during the entire last glacial cycle ([delta][sup 18]O; stages 2, 3, and 4). Anoxia is inferred from the concomitant enrichment of organic carbon and authigenic uranium in the glacial sections of a core from the deep eastern Arabian Sea. The anoxic conditions during the last glacial period, probably caused by a change in deep water circulation, evidently enhanced preservation of organic matter and simultaneous removal of uranium from seawater. 57 refs., 3 figs., 2 tabs.

  4. 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.

  5. Geochemical Impacts of Leaking CO2 from Subsurface Storage Reservoirs to Unconfined and Confined Aquifers

    SciTech Connect (OSTI)

    Qafoku, Nikolla; Brown, Christopher F.; Wang, Guohui; Sullivan, E. C.; Lawter, Amanda R.; Harvey, Omar R.; Bowden, Mark

    2013-04-15T23:59:59.000Z

    Experimental research work has been conducted and is undergoing at Pacific Northwest National Laboratory (PNNL) to address a variety of scientific issues related with the potential leaks of the carbon dioxide (CO2) gas from deep storage reservoirs. The main objectives of this work are as follows: • Develop a systematic understanding of how CO2 leakage is likely to influence pertinent geochemical processes (e.g., dissolution/precipitation, sorption/desorption and redox reactions) in the aquifer sediments. • Identify prevailing environmental conditions that would dictate one geochemical outcome over another. • Gather useful information to support site selection, risk assessment, policy-making, and public education efforts associated with geological carbon sequestration. In this report, we present results from experiments conducted at PNNL to address research issues related to the main objectives of this effort. A series of batch and column experiments and solid phase characterization studies (quantitative x-ray diffraction and wet chemical extractions with a concentrated acid) were conducted with representative rocks and sediments from an unconfined, oxidizing carbonate aquifer, i.e., Edwards aquifer in Texas, and a confined aquifer, i.e., the High Plains aquifer in Kansas. These materials were exposed to a CO2 gas stream simulating CO2 gas leaking scenarios, and changes in aqueous phase pH and chemical composition were measured in liquid and effluent samples collected at pre-determined experimental times. Additional research to be conducted during the current fiscal year will further validate these results and will address other important remaining issues. Results from these experimental efforts will provide valuable insights for the development of site-specific, generation III reduced order models. In addition, results will initially serve as input parameters during model calibration runs and, ultimately, will be used to test model predictive capability and competency. The results from these investigations will provide useful information to support site selection, risk assessment, and public education efforts associated with geological, deep subsurface CO2 storage and sequestration.

  6. Geochemical and physical properties of wetland soils at the Savannah River site

    SciTech Connect (OSTI)

    Dixon, K.L; Rogers, V.A.; Conner, S.P.; Cummings, C.L.; Gladden, J.B.; Weber, J.M.

    1996-05-01T23:59:59.000Z

    The Savannah River Site (SRS), located in Aiken, Allendale, and Barnwell Counties, South Carolina, is a nuclear production facility operated for the U.S. Department of Energy (DOE) by Westinghouse Savannah River Company (WSRC). To facilitate future human health and ecological risk assessments, treatability studies, remedial investigations, and feasibility studies for its wetland areas, SRS needs a database of background geochemical and physical properties of wetland soils. These data are needed for comparison to data collected from wetland soils that may have been affected by SRS operations. SRS contains 36,000 acres of wetlands and an additional 5,000 acres of bottom land soils subject to flooding. Recent studies of wetland soils near various waste units at SRS show that some wetlands have been impacted by releases of contaminants resulting from SRS operations (WSRC, 1992). Waste waters originating from the operations facilities typically have been discharged into seepage basins located in upland soils, direct discharge of waste water to wetland areas has been minimal. This suggests that impacted wetland areas have been affected indirectly as a result of transport mechanisms such as surface runoff, groundwater seeps, fluvial or sediment transport, and leaching. Looney et al. (1990) conducted a study to characterize the geochemical and physical properties of upland soils and shallow sediments on the SRS. A primary objective of the upland study was to collect the data needed to assess the qualitative and quantitative impacts of SRS operations on the environment. By comparing the upland soils data to data collected from waste units located in similar soils, SRS impacts could be assessed. The data were also intended to aid in selection of remediation alternatives. Because waste units at SRS have historically been located in upland areas, wetland soils were not sampled. (Abstract Truncated)

  7. Geochemical Characterization Using Geophysical Data and Markov Chain Monte Carolo methods: A Case Study at the South Oyster Bacterial Transport Site in Virginia

    SciTech Connect (OSTI)

    Chen, Jinsong; Hubbard, Susan; Rubin, Yoram; Murray, Chris; Roden, Eric; Majer, Ernest

    2003-11-18T23:59:59.000Z

    The spatial distribution of field-scale geochemical parameters, such as extractable Fe(II) and Fe(III), influences microbial processes and thus the efficacy of bioremediation. Because traditional characterization of those parameters is invasive and laborious, it is rarely performed sufficiently at the field-scale. Since both geochemical and geophysical parameters often correlate to some common physical properties (such as lithofacies), we investigated the utility of tomographic radar attenuation data for improving estimation of geochemical parameters using a Markov Chain Monte Carlo (MCMC) approach. The data used in this study included physical, geophysical, and geochemical measurements collected in and between several boreholes at the DOE South Oyster Bacterial Transport Site in Virginia. Results show that geophysical data, constrained by physical data, provided field-scale information about extractable Fe(II) and Fe(III) in a minimally invasive manner and with a resolution unparalleled by other geochemical characterization methods. This study presents our estimation framework for estimating Fe(II) and Fe(III), and its application to a specific site. Our hypothesis--that geochemical parameters and geophysical attributes can be linked through their mutual dependence on physical properties--should be applicable for estimating other geochemical parameters at other sites.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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...

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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 für 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

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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 Æ 2008 Ó Springer Science+Business Media, LLC 2008 Abstract Many toxic effects of treated wastewater

  14. 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.

  15. Geologic, geophysical, and geochemical aspects of site-specific studies of the geopressured-geothermal energy resource of southern Louisiana. Final report

    SciTech Connect (OSTI)

    Pilger, R.H. Jr. (ed.)

    1985-01-01T23:59:59.000Z

    The report consists of four sections dealing with progress in evaluating geologic, geochemical, and geophysical aspects of geopressured-geothermal energy resources in Louisiana. Separate abstracts have been prepared for the individual sections. (ACR)

  16. Geochemical maps showing the distribution and abundance of selected elements in stream-sediment samples, Solomon and Bendeleben 1 degree by 3 degree quadrangles, Seward Peninsula, Alaska

    SciTech Connect (OSTI)

    Smith, S.C.; King, H.D.; O'Leary, R.M.

    1989-01-01T23:59:59.000Z

    Geochemical maps showing the distribution and abundance of selected elements in stream-sediment samples, Solomon and Bendeleben 1{degree} by 3{degree} quadrangles, Seward Peninsula, Alaska is presented.

  17. 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.

  18. Preburn versus postburn mineralogical and geochemical characteristics of overburden and coal at the Hanna, Wyoming underground coal gasification site

    SciTech Connect (OSTI)

    Oliver, R.L.; Youngberg, A.D.

    1983-12-01T23:59:59.000Z

    Hundreds of mineralogic and geochemical tests were done under US Department of Energy contracts on core samples taken from the Hanna underground coal gasification site. These tests included x-ray diffraction studies of minerals in coal ash, overburden rocks, and heat-altered rocks; x-ray fluorescence analyses of oxides in coal ash and heat-altered rocks; semi-quantitative spectrographic analyses of elements in coal, overburden, and heat-altered rocks; chemical analyses of elements and compounds in coal, overburden, and heat-altered rocks and ASTM proximate and ultimate analyses of coal and heat-altered coal. These data sets were grouped, averaged, and analyzed to provide preburn and postburn mineralogic and geochemical characteristics of rock units at the site. Where possible, the changes in characteristics from the preburn to the postburn state are related to underground coal gasification processes. 11 references, 13 figures, 8 tables.

  19. Up-Scaling Geochemical Reaction Rates for Carbon Dioxide (CO2) in Deep Saline Aquifers

    SciTech Connect (OSTI)

    Peters, Catherine A

    2013-02-28T23:59:59.000Z

    Geochemical reactions in deep subsurface environments are complicated by the consolidated nature and mineralogical complexity of sedimentary rocks. Understanding the kinetics of these reactions is critical to our ability to make long-term predictions about subsurface processes such as pH buffering, alteration in rock structure, permeability changes, and formation of secondary precipitates. In this project, we used a combination of experiments and numerical simulation to bridge the gap between our knowledge of these reactions at the lab scale and rates that are meaningful for modeling reactive transport at core scales. The focus is on acid-driven mineral dissolution, which is specifically relevant in the context of CO2-water-rock interactions in geological sequestration of carbon dioxide. The project led to major findings in three areas. First, we modeled reactive transport in pore-network systems to investigate scaling effects in geochemical reaction rates. We found significant scaling effects when CO2 concentrations are high and reaction rates are fast. These findings indicate that the increased acidity associated with geological sequestration can generate conditions for which proper scaling tools are yet to be developed. Second, we used mathematical modeling to investigate the extent to which SO2, if co-injected with CO2, would acidify formation brines. We found that there exist realistic conditions in which the impact on brine acidity will be limited due to diffusion rate-limited SO2 dissolution from the CO2 phase, and the subsequent pH shift may also be limited by the lack of availability of oxidants to produce sulfuric acid. Third, for three Viking sandstones (Alberta sedimentary basin, Canada), we employed backscattered electron microscopy and energy dispersive X-ray spectroscopy to statistically characterize mineral contact with pore space. We determined that for reactive minerals in sedimentary consolidated rocks, abundance alone is not a good predictor of mineral accessible surface area, and should not be used in reactive transport modeling. Our work showed that reaction rates would be overestimated by three to five times.

  20. GEOCHEMICAL APPROACHES TO THE STUDY OF LIFE AND DEATH OF DINOSAURS FROM THE EARLY CRETACEOUS CEDAR MOUNTAIN FORMATION, UTAH

    E-Print Network [OSTI]

    Suarez, Celina Angelica

    2010-04-22T23:59:59.000Z

    ___________________________ G.L. Macpherson ___________________________ Larry D. Martin Date defended:_______________ iii ABSTRACT Celina A. Suarez, Ph.D. Department of Geology, April 2010 University of Kansas In this dissertation, geochemical analysis..., it can be determined that the proximity of the Western Interior Seaway and the rise of the Sevier Mountains were the cause of isotopic variability and dominant control on regional climate during the Cedar Mountain Formation time. iv...

  1. Enhanced Land Subsidence and Seidment Dynamics in Galveston Bay- Implications for Geochemical Processes and Fate and Transport of Contaminants

    E-Print Network [OSTI]

    Almukaimi, Mohammad E

    2013-07-05T23:59:59.000Z

    ENHANCED LAND SUBSIDENCE AND SEDIMENT DYNAMICS IN GALVESTON BAY- IMPLICATIONS FOR GEOCHEMICAL PROCESSES AND FATE AND TRANSPORT OF CONTAMINANTS A Thesis by MOHAMMAD ALMUKAIMI Submitted to the Office of Graduate Studies of Texas A... August 2013 Major Subject: Oceanography Copyright 2013 Mohammad Almukaimi ii ABSTRACT Galveston Bay is the second largest estuary in the Gulf of Mexico. The bay?s watershed and shoreline contains one of the largest concentrations...

  2. Geochemical and physical properties of soils and shallow sediments at the Savannah River Site

    SciTech Connect (OSTI)

    Looney, B.B.; Eddy, C.A.; Ramdeen, M.; Pickett, J. (Savannah River Lab., Aiken, SC (USA)); Rogers, V. (Soil Conservation Service, Aiken, SC (USA). Savannah River Site Savannah River Lab., Aiken, SC (USA)); Scott, M.T.; Shirley, P.A. (Sirrine Environmental Consultants, Greenville, SC (USA))

    1990-08-31T23:59:59.000Z

    A program to characterize the geochemical and physical properties of the unimpacted soils and shallow sediments at the Savannah River Site (SRS) has been completed. The maximum, minimum, median, standard deviation, and mean values for metals, radionuclides, inorganic anions, organic compounds, and agricultural indicator parameters are summarized for six soil series that were identified as representative of the 29 soil series at SRS. The soils from unimpacted areas of SRS are typical of soils found in moderately aggressive weathering environments, including the southeastern United States. Appendix 8 organic compounds were detected in all samples. Since these constituents are not generally present in soil, this portion of the investigation was intended to assess possible laboratory artifacts. An additional objective of the SRS Soil Study was to determine if the composition of the split spoon sampler biased chemical analysis of the soils. Twenty-five duplicate samples were analyzed for a number of metals, radiological and agricultural parameters, and organics by two laboratories currently contracted with to analyze samples during waste site characterization. In all cases, the absolute values of the average differences are relatively small compared to the overall variability in the population. 31 refs., 14 figs., 48 tabs.

  3. Geophysical Monitoring of Coupled Microbial and Geochemical Processes During Stimulated Subsurface Bioremediation

    SciTech Connect (OSTI)

    Williams, Kenneth H.; Kemna, Andreas; Wilkins, Michael J.; Druhan, Jennifer L.; Arntzen, Evan V.; N'Guessan, A. Lucie; Long, Philip E.; Hubbard, Susan S.; Banfield, Jillian F.

    2009-08-05T23:59:59.000Z

    Understanding how microorganisms alter their physical and chemical environment during bioremediation is hindered by our inability to resolve subsurface microbial activity with high spatial resolution. Here we demonstrate the use of a minimally invasive geophysical technique to monitor stimulated microbial activity during acetate amendment in an aquifer near Rifle, Colorado. During electrical induced polarization (IP) measurements, spatiotemporal variations in the phase response between imposed electric current and the resultant electric field correlated with changes in groundwater geochemistry accompanying stimulated iron and sulfate reduction and sulfide mineral precipitation. The magnitude of the phase response varied with measurement frequency (0.125 and 1 Hz) andwasdependent upon the dominant metabolic process. The spectral effect was corroborated using a biostimulated column experiment containing Rifle sediments and groundwater. Fluids and sediments recovered from regions exhibiting an anomalous phase response were enriched in Fe(II), dissolved sulfide, and cell-associated FeS nanoparticles. The accumulation of mineral precipitates and electroactive ions altered the ability of pore fluids to conduct electrical charge, accounting for the anomalous IP response and revealing the usefulness of multifrequency IP measurements for monitoring mineralogical and geochemical changes accompanying stimulated subsurface bioremediation.

  4. Geochemical evaluation of oils and source rocks from the Western Siberian basin, U. S. S. R

    SciTech Connect (OSTI)

    Peters, K.E.; Huizinga, B.J. (Chevron Overseas Petroleum, Inc., San Ramon, CA (United States)); Moldowan, J.M. (Chevron Oil Field Research Co., Richmond, CA (United States)); Kontorovich, A.E.; Stasova, O. (Siberian Scientific Research Institute for Geology, Geophysics and Mineral Resources, Novobsibirsk (Russian Federation)); Demaison, G.J.

    1991-03-01T23:59:59.000Z

    Although the Western Siberian basin is among the most prolific in the world, there has been disagreement among Soviet geoscientists on the origin of the petroleum within this basin. Screening geochemical analyses were used to select several oils and potential source rocks for a preliminary study using detailed biomarker and supporting geochemistry. Possible sources for this petroleum include rocks of Middle Jurassic, Upper Jurassic, and Lower Cretaceous age. Results indicate that most of the analyzed Western Siberian oils, occurring in reservoirs from Middle Jurassic to Late Cretaceous in age, are derived from the Upper Jurassic Bazhenov Formation. The locations of the samples in the study generally correspond to the distribution of the most effective oil-generative parts of the Bazhenov Formation. Analyses show that the Bazhenov rock samples contain abundant marine algal and bacterial organic matter, preserved under anoxic depositional conditions. Biomarkers show that thermal maturities of the samples range from the early to late oil-generative window and that some are biodegraded. For example, the Salym No. 114 oil, which flowed directly from the Bazhenov Formation, shows a maturity equivalent to the late oil window. The Van-Egan no. 110 oil shows maturity equivalent to the early oil window and is biodegraded. This oil shows preferential microbial conversion of lower homologs of the 17{alpha}, 21{beta}(H)-hopanes to 25-nor-17{alpha}(H)-hopanes.

  5. Integrated geochemical and paleoecological approach to petroleum source rock evaluation, Lower Niobrara Formation (Cretaceous), Lyons, Colorado

    SciTech Connect (OSTI)

    Barlow, L.K.

    1986-10-01T23:59:59.000Z

    A detailed study of paleoecological, geochemical, and stable isotopic properties of the lower Niobrara Formation (upper Turonian to lower Coniacian) was undertaken in order to evaluate petroleum source rock potential and to gain an understanding of the processes affecting variation in organic carbon content. The highest organic carbon contents in the lower Niobrara Formation occur in the lower shale unit of the Smoky Hill Shale Member. Trends in extent of bioturbation, organic carbon contents, and oxygen isotopic ratios of carbonates suggest that paleoclimatic factors influenced bottom water environments during deposition of this unit. A shift toward a more negative oxygen isotopic ratio in the lower shale unit is interpreted to be a result of decreased surface water salinity due to increased fresh water input and possibly to climatic warming. Resultant stratification of the water column limited benthic oxygenation thereby limiting benthic activity, enhancing the preservation of marine organic matter, and increasing source rock potential for petroleum. Data from underlying and overlying units in the lower Niobrara Formation suggest more normal marine conditions with well-oxygenated bottom waters, normal levels of bioturbation, and relatively low organic carbon contents. Pyrolysis data are interpreted to reflect a principally marine source of organic matter with substantial alteration due to bioturbation and thermal evolution. Elevated thermal maturity of the sections at Lyons is inferred to be a local feature caused by local heating associated with fluid movement along fault zones or with emplacement of tertiary sills.

  6. Geochemical studies of crude oil generation, migration, and destruction in Mississippi salt basin

    SciTech Connect (OSTI)

    Sassen, R.; Moore, C.H.; Nunn, J.A.; Meendsen, F.C.; Heydari, E.

    1987-09-01T23:59:59.000Z

    The main source for crude oil in the Mississippi salt basin is the laminated lime mudstone facies of the lower Smackover. Crude oil generation and migration commenced at a level of thermal maturity equivalent to about 0.55% vitrinite reflectance. Short-range lateral migration of crude oil was focused on upper Smackover and Norphlet reservoirs, but vertical migration also charged some overlying Cotton Valley, Rodessa, lower Tuscaloosa, and Eutaw reservoirs. Following migration from the lower Smackover, thermal maturity history of reservoir rocks controls the preservation of crude oil, gas condensate, and methane. Slow thermal cracking of crude oil occurred in deep upper Smackover reservoirs, resulting in formation of gas condensate and precipitation of solid bitumen. The maximum thermal maturity for preservation of condensate is equivalent to about 1.3% vitrinite reflectance. Only methane, pyrobitumen, and nonhydrocarbon gases, including hydrogen sulfide, persist at higher levels of thermal maturity. Early destruction of methane in deep upper Smackover reservoirs near the Wiggins arch is driven by thermochemical sulfate reduction. Lesser availability of sulfate in Norphlet reservoirs could account for methane preservation at higher levels of thermal maturity. One basic geochemical strategy for further exploration of the Mississippi salt basin is to focus exploration effort on traps with reservoirs in the thermal maturity window for hydrocarbon preservation. Another strategy is to avoid drilling traps with overmature reservoir rocks.

  7. 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.

  8. 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. ...

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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...

  15. 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.

  16. 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...

  17. 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.

  18. 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.

  19. 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

  20. 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...

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. Geochemical Data Package for the 2005 Hanford Integrated Disposal Facility Performance Assessment

    SciTech Connect (OSTI)

    Krupka, Kenneth M.; Serne, R JEFFREY.; Kaplan, D I.

    2004-09-30T23:59:59.000Z

    CH2M HILL Hanford Group, Inc. (CH2M HILL) is designing and assessing the performance of an integrated disposal facility (IDF) to receive low-level waste (LLW), mixed low-level waste (MLLW), immobilized low-activity waste (ILAW), and failed or decommissioned melters. The CH2M HILL project to assess the performance of this disposal facility is the Hanford IDF Performance Assessment (PA) activity. The goal of the Hanford IDF PA activity is to provide a reasonable expectation that the disposal of the waste is protective of the general public, groundwater resources, air resources, surface-water resources, and inadvertent intruders. Achieving this goal will require prediction of contaminant migration from the facilities. This migration is expected to occur primarily via the movement of water through the facilities, and the consequent transport of dissolved contaminants in the vadose zone to groundwater where contaminants may be re-introduced to receptors via drinking water wells or mixing in the Columbia River. Pacific Northwest National Laboratory (PNNL) assists CH2M HILL in their performance assessment activities. One of the PNNL tasks is to provide estimates of the geochemical properties of the materials comprising the IDF, the disturbed region around the facility, and the physically undisturbed sediments below the facility (including the vadose zone sediments and the aquifer sediments in the upper unconfined aquifer). The geochemical properties are expressed as parameters that quantify the adsorption of contaminants and the solubility constraints that might apply for those contaminants that may exceed solubility constraints. The common parameters used to quantify adsorption and solubility are the distribution coefficient (Kd) and the thermodynamic solubility product (Ksp), respectively. In this data package, we approximate the solubility of contaminants using a more simplified construct, called the solution concentration limit, a constant value. The Kd values and solution concentration limits for each contaminant are direct inputs to subsurface flow and transport codes used to predict the performance of the IDF system. In addition to the best-estimate Kd values, a reasonable conservative value and a range are provided. The data package does not list estimates for the range in solubility limits or their uncertainty. However, the data package does provide different values for both the Kd values and solution concentration limits for different spatial zones in the IDF system and does supply time-varying Kd values for the cement solidified waste. The Kd values and solution concentration limits presented for each contaminant were previously presented in a report prepared by Kaplan and Serne (2000) for the 2001 ILAW PA, and have been updated to include applicable data from investigations completed since the issuance of that report and improvements in our understanding of the geochemistry specific to Hanford. A discussion is also included of the evolution of the Kd values recommended from the original 1999 ILAW PA through the 2001 ILAW and 2003 Supplement PAs to the current values to be used for the 2005 IDF PA for the key contaminants of concern: Cr(VI), nitrate, 129I, 79Se, 99Tc, and U(VI). This discussion provides the rationale for why certain Kd have changed with time.

  10. Geochemical information for sites contaminated with low-level radioactive wastes. III. Weldon Spring Storage Site

    SciTech Connect (OSTI)

    Seeley, F.G.; Kelmers, A.D.

    1985-02-01T23:59:59.000Z

    The Weldon Spring Storage Site (WSSS), which includes both the chemical site and the quarry, became radioactively contaminated as the result of wastes that were being stored from operations to recover uranium from pitchblende ores in the 1940s and 1950s. The US Department of Energy (DOE) is considering various remedial action options for the WSSS. This report describes the results of geochemical investigations carried out at Oak Ridge National Laboratory (ORNL) to support these activities and to help quantify various remedial action options. Soil and groundwater samples were characterized, and uranium and radium sorption ratios were measured in site soil/groundwater systems by batch contact methodology. Soil samples from various locations around the raffinate pits were found to contain major amounts of silica, along with illite as the primary clay constituent. Particle sizes of the five soil samples were variable (50% distribution point ranging from 12 to 81 ..mu..m); the surface areas varied from 13 to 62 m/sup 2//g. Elemental analysis of the samples showed them to be typical of sandy clay and silty clay soils. Groundwater samples included solution from Pit 3 and well water from Well D. Anion analyses showed significant concentrations of sulfate and nitrate (>350 and >7000 mg/L, respectively) in the solution from Pit 3. These anions were also present in the well water, but in lower concentrations. Uranium sorption ratios for four of the soil samples contacted with the solution from Pit 3 were moderate to high (approx. 300 to approx. 1000 mL/g). The fifth sample had a ratio of only 12 mL/g. Radium sorption ratios for the five samples were moderate to high (approx. 600 to approx. 1000 mL/g). These values indicate that soil at the WSSS may show favorable retardation of uranium and radium in the groundwater. 13 references, 13 figures, 10 tables.

  11. Model-Based Analysis of the Role of Biological, Hydrological and Geochemical Factors Affecting Uranium Bioremediation

    SciTech Connect (OSTI)

    Zhao, Jiao; Scheibe, Timothy D.; Mahadevan, Radhakrishnan

    2011-01-24T23:59:59.000Z

    Uranium contamination is a serious concern at several sites motivating the development of novel treatment strategies such as the Geobacter-mediated reductive immobilization of uranium. However, this bioremediation strategy has not yet been optimized for the sustained uranium removal. While several reactive-transport models have been developed to represent Geobacter-mediated bioremediation of uranium, these models often lack the detailed quantitative description of the microbial process (e.g., biomass build-up in both groundwater and sediments, electron transport system, etc.) and the interaction between biogeochemical and hydrological process. In this study, a novel multi-scale model was developed by integrating our recent model on electron capacitance of Geobacter (Zhao et al., 2010) with a comprehensive simulator of coupled fluid flow, hydrologic transport, heat transfer, and biogeochemical reactions. This mechanistic reactive-transport model accurately reproduces the experimental data for the bioremediation of uranium with acetate amendment. We subsequently performed global sensitivity analysis with the reactive-transport model in order to identify the main sources of prediction uncertainty caused by synergistic effects of biological, geochemical, and hydrological processes. The proposed approach successfully captured significant contributing factors across time and space, thereby improving the structure and parameterization of the comprehensive reactive-transport model. The global sensitivity analysis also provides a potentially useful tool to evaluate uranium bioremediation strategy. The simulations suggest that under difficult environments (e.g., highly contaminated with U(VI) at a high migration rate of solutes), the efficiency of uranium removal can be improved by adding Geobacter species to the contaminated site (bioaugmentation) in conjunction with the addition of electron donor (biostimulation). The simulations also highlight the interactive effect of initial cell concentration and flow rate on U(VI) reduction.

  12. USER’S GUIDE of TOUGH2-EGS: A Coupled Geomechanical and Reactive Geochemical Simulator for Fluid and Heat Flow in Enhanced Geothermal Systems Version 1.0

    SciTech Connect (OSTI)

    Fakcharoenphol, Perapon [Colorado School of Mines; Xiong, Yi [Colorado School of Mines; Hu, Litang; Winterfeld, Philip H. [Colorado School of Mines; Xu, Tianfu [Lawrence Berkeley National Laboratory; Wu, Yu-Shu [Colorado School of Mines

    2013-05-01T23:59:59.000Z

    TOUGH2-EGS is a numerical simulation program coupling geomechanics and chemical reactions for fluid and heat flows in porous media and fractured reservoirs of enhanced geothermal systems. The simulator includes the fully-coupled geomechanical (THM) module, the fully-coupled geochemical (THC) module, and the sequentially coupled reactive geochemistry (THMC) module. The fully-coupled flow-geomechanics model is developed from the linear elastic theory for the thermo-poro-elastic system and is formulated with the mean normal stress as well as pore pressure and temperature. The chemical reaction is sequentially coupled after solution of flow equations, which provides the flow velocity and phase saturation for the solute transport calculation at each time step. In addition, reservoir rock properties, such as porosity and permeability, are subjected to change due to rock deformation and chemical reactions. The relationships between rock properties and geomechanical and chemical effects from poro-elasticity theories and empirical correlations are incorporated into the simulator. This report provides the user with detailed information on both mathematical models and instructions for using TOUGH2-EGS for THM, THC or THMC simulations. The mathematical models include the fluid and heat flow equations, geomechanical equation, reactive geochemistry equations, and discretization methods. Although TOUGH2-EGS has the capability for simulating fluid and heat flows coupled with both geomechanical and chemical effects, it is up to the users to select the specific coupling process, such as THM, THC, or THMC in a simulation. There are several example problems illustrating the applications of this program. These example problems are described in details and their input data are presented. The results demonstrate that this program can be used for field-scale geothermal reservoir simulation with fluid and heat flow, geomechanical effect, and chemical reaction in porous and fractured media.

  13. 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.

  14. 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.

  15. 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.

  16. 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...

  17. 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%.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Sampling designs for geochemical baseline studies in the Colorado oil shale region: a manual for practical application

    SciTech Connect (OSTI)

    Klusman, R. W.; Ringrose, C. D.; Candito, R. J.; Zuccaro, B.; Rutherford, D. W.; Dean, W. E.

    1980-06-01T23:59:59.000Z

    This manual presents a rationale for sampling designs, and results of geochemical baseline studies in the Colorado portion of the oil-shale region. The program consists of a systematic trace element study of soils, stream sediments, and plants carried out in a way to be conservative of human and financial resources and yield maximum information. Extension of this approach to other parameters, other locations, and to environmental baseline studies in general is a primary objective. A baseline for any geochemical parameter can be defined as the concentration of that parameter in a given medium such as soil, the range of its concentration, and the geographic scale of variability. In air quality studies, and to a lesser extent for plants, the temporal scale of variability must also be considered. In studies of soil, the temporal variablility does not become a factor until such time that a study is deemed necessary to evaluate whether or not there have been changes in baseline levels as a result of development. The manual is divided into five major parts. The first is a suggested sampling protocol which is presented in an outline form for guiding baseline studies in this area. The second section is background information on the physical features of the area of study, trace elements of significance occurring in oil shale, and the sample media used in these studies. The third section is concerned primarily with sampling design and its application to the geochemical studies of the oil shale region. The last sections, in the form of appendices, provide actual data and illustrate in a systematic manner, the calculations performed to obtain the various summary data. The last segment of the appendices is a more academic discussion of the geochemistry of trace elements and the parameters of importance influencing their behavior in natural systems.

  3. GIS Regional Spatial Data from the Great Basin Center for Geothermal Energy: Geochemical, Geodesic, Geologic, Geophysical, Geothermal, and Groundwater Data

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

    The Great Basin Center for Geothermal Energy, part of the University of Nevada, Reno, conducts research towards the establishment of geothermal energy as an economically viable energy source within the Great Basin. The Center specializes in collecting and synthesizing geologic, geochemical, geodetic, geophysical, and tectonic data, and using Geographic Information System (GIS) technology to view and analyze this data and to produce favorability maps of geothermal potential. The center also makes its collections of spatial data available for direct download to the public. Data are in Lambert Conformable Conic Projection.

  4. Petrographic and geochemical anatomy of lithotypes from the Blue Gem coal bed, Southeastern Kentucky

    SciTech Connect (OSTI)

    Hower, J.C.; Taulbee, D.N.; Morrell, L.G. [Univ. of Kentucky, Lexington, KY (United States)] [and others

    1994-12-31T23:59:59.000Z

    The nature of the association of major, minor, and trace elements with coal has been the subject of intensive research by coal scientists (Swaine; and references cited therein). Density gradient centrifugation (DGC) offers a technique with which ultrafine coal particles can be partitioned into a density spectrum, portions of which represent nearly pure monomaceral concentrates. DGC has been typically conducted on demineralized coals assuring, particularly at lower specific gravities, that the resulting DGC fractions would have very low ash contents. In order to determine trends in elemental composition, particularly with a view towards maceral vs. mineral association, it is necessary to avoid demineralization. To this end the low-ash, low-sulfur Blue Gem coal bed (Middle Pennsylvanian Breathitt Formation) from Knox County, Kentucky, was selected for study. The objective of this study was to determine the petrography and chemistry, with particular emphasis on the ash geochemistry, of DGC separates of lithotypes of the Blue Gem coal bed.

  5. 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.

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

    SciTech Connect (OSTI)

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

    2009-12-09T23:59:59.000Z

    The conclusions of this paper are: (1) The gradient of the SLIM-based technology is believed to be achievable in the same range as it is for the gradient of a modern rf-linac technology ({approx}100 MeV per meter). (2) The SLIM concept is based on the nsec TEM pulse mode operation with no laser or rf systems. (3) Main components of SLIM are not stressed while the energy is pumped into the induction system. Components can accept the hard environment conditions such as a radiation dose, mismatch, hard electromagnetic nose level, etc. Only for several nanoseconds the switch is OFF and produces a stress in the induction system. At that time, the delivery of energy to the beam takes place. (4) The energy in the induction system initially is storied in the magnetic field when the switch is ON. That fact makes another benefit: a low voltage power supplies can be used. The reliability of a lower voltage power supply is higher and they are cheaper. (5) The coreless SLIM concept offers to work in the MHz range of repetition rate. The induction system has the high electric efficiency (much higher than the DWA). (6) The array of lined up and activated SLIM cells is believed to be a solid state structure of novel accelerating technology. The electron-hole plasma in the high power solid state structure is precisely controlled by the electromagnetic process of a pulsed power supply.

  7. Convergence in gradient systems with branching of equilibria

    SciTech Connect (OSTI)

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

    2007-06-30T23:59:59.000Z

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

  8. Geochemical Processes at the Carbon Steel/Bentonite Interface in Repository Conditions

    SciTech Connect (OSTI)

    Torres, Elena; Turrero, Maria Jesus; Martin, Pedro Luis [Division of Engineered and Geological Barriers, Ciemat, Avenida Complutense 22, Madrid, 28047 (Spain)

    2007-07-01T23:59:59.000Z

    The Deep Geological Repository (DGR) is currently the most accepted management option for the isolation of high level radioactive wastes. The DGR is based on a multi-barrier system, which will limit releases of mobile radionuclides to the biosphere. In the Spanish design of the repository the spent fuel is encapsulated in canisters of carbon steel. The space between the canister and the host geological formation will be filled with bentonite buffer clay. The effects of the reactions occurring in the canister/compacted bentonite interface should be understood for assessing the waste isolation. If canister failure due to corrosion occurs [1] the iron will be in contact with the bentonite affecting its properties, both in terms of the chemical evolution of the pore water and the properties of the bentonite. Iron precipitates can significantly change the properties of bentonite crucial for the migration of radionuclides such as porosity or sorption capacity. Ferrous ions can also pass through bentonite and precipitate as iron oxy-hydroxides that can form pseudocolloids with radionuclides and quickly migrate in the host rock without sorption. But, the major effect of corrosion products will probably be the change of pH and E{sub h} affecting the stability of the barrier and the release rate of radionuclides. There are a number of studies on the corrosion of metals that could be used as canister [2], also studies on the iron-bentonite interaction [3], but not as many studies are focused to the iron-compacted bentonite interaction [4,5] and the associated mineralogical, chemical and physicochemical transformations of the bentonite [6]. The experimental studies conducted by CIEMAT are focused on the iron canister corrosion products interaction with the bentonite system and are based on a series of short term and medium term experiments conceived at different scales, from conventional laboratory experiments and experiments in cylindrical cells, to those specifically designed 3D mock up experiments, the so called 'GAME (Geochemical Mock up experiments) scale'. The experiments proposed in the context of the NF-PRO project (which is focused on understanding physical and numerical modelling of the key processes in the Near-Field, and their coupling, for different host rocks and repository strategies) have two main objectives: the study of the corrosion products generated in the canister/bentonite interface at the repository conditions, and to determine how the corrosion affects the properties of the bentonite. This paper describes the first tests performed to reach the objectives proposed and presents the results on the analyses of the corrosion products from carbon steel in contact with bentonite for a period of six months and one year subjected to heating and hydration. (authors)

  9. Final Report: Molecular Basis for Microbial Adhesion and Geochemical Surface Reactions: A Study Across Scales

    SciTech Connect (OSTI)

    Dixon, David Adams [The University of Alabama

    2013-06-27T23:59:59.000Z

    Computational chemistry was used to help provide a molecular level description of the interactions of Gram-negative microbial membranes with subsurface materials. The goal is to develop a better understanding of the molecular processes involved in microbial metal binding, microbial attachment to mineral surfaces, and, eventually, oxidation/reduction reactions (electron transfer) that can occur at these surfaces and are mediated by the bacterial exterior surface. The project focused on the interaction of the outer microbial membrane, which is dominated by an exterior lipopolysaccharide (LPS) portion, of Pseudomonas aeruginosa with the mineral goethite and with solvated ions in the environment. This was originally a collaborative project with T.P. Straatsma and B. Lowery of the Pacific Northwest National Laboratory. The University of Alabama effort used electronic structure calculations to predict the molecular behavior of ions in solution and the behavior of the sugars which form a critical part of the LPS. The interactions of the sugars with metal ions are expected to dominate much of the microscopic structure and transport phenomena in the LPS. This work, in combination with the molecular dynamics simulations of Straatsma and the experimental electrochemistry and microscopy measurements of Lowry, both at PNNL, is providing new insights into the detailed molecular behavior of these membranes in geochemical environments. The effort at The University of Alabama has three components: solvation energies and structures of ions in solution, prediction of the acidity of the critical groups in the sugars in the LPS, and binding of metal ions to the sugar anions. An important aspect of the structure of the LPS membrane as well as ion transport in the LPS is the ability of the sugar side groups such as the carboxylic acids and the phosphates to bind positively charged ions. We are studying the acidity of the acidic side groups in order to better understand the ability of these groups to bind metal ions. We need to understand the solvation properties of the metal ions in solution and their ability to bind not only to the sugars but to proteins and to other anions. Our goal is then to be able to predict the ability of the side groups to bind metal ions. One result from the earlier molecular dynamics simulations is the exclusion of water from the inner hydrophobic part of the membrane. We thus need to investigate the binding of the cations in media with different dielectric constants.

  10. 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.

  11. Lithium ion diffusion in Li ?-alumina single crystals measured by pulsed field gradient NMR spectroscopy

    SciTech Connect (OSTI)

    Chowdhury, Mohammed Tareque, E-mail: mtareque@mail.tagen.tohoku.ac.jp; Takekawa, Reiji; Iwai, Yoshiki; Kuwata, Naoaki; Kawamura, Junichi [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1, Katahira, Aoba-ku Sendai 980-8577 (Japan)] [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1, Katahira, Aoba-ku Sendai 980-8577 (Japan)

    2014-03-28T23:59:59.000Z

    The lithium ion diffusion coefficient of a 93% Li ?-alumina single crystal was measured for the first time using pulsed field gradient (PFG) NMR spectroscopy with two different crystal orientations. The diffusion coefficient was found to be 1.2 × 10{sup ?11} m{sup 2}/s in the direction perpendicular to the c axis at room temperature. The Li ion diffusion coefficient along the c axis direction was found to be very small (6.4 × 10{sup ?13} m{sup 2}/s at 333 K), which suggests that the macroscopic diffusion of the Li ion in the ?-alumina crystal is mainly two-dimensional. The diffusion coefficient for the same sample was also estimated using NMR line narrowing data and impedance measurements. The impedance data show reasonable agreement with PFG-NMR data, while the line narrowing measurements provided a lower value for the diffusion coefficient. Line narrowing measurements also provided a relatively low value for the activation energy and pre-exponential factor. The temperature dependent diffusion coefficient was obtained in the temperature range 297–333 K by PFG-NMR, from which the activation energy for diffusion of the Li ion was estimated. The activation energy obtained by PFG-NMR was smaller than that obtained by impedance measurements, which suggests that thermally activated defect formation energy exists for 93% Li ?-alumina single crystals. The diffusion time dependence of the diffusion coefficient was observed for the Li ion in the 93% Li ?-alumina single crystal by means of PFG-NMR experiments. Motion of Li ion in fractal dimension might be a possible explanation for the observed diffusion time dependence of the diffusion coefficient in the 93% Li ?–alumina system.

  12. Investigation of Temperature-Driven Water Transport in Polymer Electrolyte Fuel Cell: Phase-Change-Induced Flow

    E-Print Network [OSTI]

    Mench, Matthew M.

    -Change-Induced Flow Soowhan Kim* and M. M. Mench**,z Fuel Cell Dynamics and Diagnostics Laboratory, DepartmentInvestigation of Temperature-Driven Water Transport in Polymer Electrolyte Fuel Cell: Phase electrolyte fuel cell materials subjected to a temperature gradient. Contrary to thermo-osmotic flow in fuel

  13. INEEL Subregional Conceptual Model Report Volume 2: Summary of Existing Knowledge of Geochemical Influences on the Fate and Transport of Contaminants in the Subsurface at the INEEL

    SciTech Connect (OSTI)

    Paul L. Wichlacz; Robert C. Starr; Brennon Orr

    2003-09-01T23:59:59.000Z

    This document summarizes previous descriptions of geochemical system conceptual models for the vadose zone and groundwater zone (aquifer) beneath the Idaho National Engineering and Environmental Laboratory (INEEL). The primary focus is on groundwater because contaminants derived from wastes disposed at INEEL are present in groundwater, groundwater provides a pathway for potential migration to receptors, and because geochemical characteristics in and processes in the aquifer can substantially affect the movement, attenuation, and toxicity of contaminants. The secondary emphasis is perched water bodies in the vadose zone. Perched water eventually reaches the regional groundwater system, and thus processes that affect contaminants in the perched water bodies are important relative to the migration of contaminants into groundwater. Similarly, processes that affect solutes during transport from nearsurface disposal facilities downward through the vadose zone to the aquifer are relevant. Sediments in the vadose zone can affect both water and solute transport by restricting the downward migration of water sufficiently that a perched water body forms, and by retarding solute migration via ion exchange. Geochemical conceptual models have been prepared by a variety of researchers for different purposes. They have been published in documents prepared by INEEL contractors, the United States Geological Survey (USGS), academic researchers, and others. The documents themselves are INEEL and USGS reports, and articles in technical journals. The documents reviewed were selected from citation lists generated by searching the INEEL Technical Library, the INEEL Environmental Restoration Optical Imaging System, and the ISI Web of Science databases. The citation lists were generated using the keywords ground water, groundwater, chemistry, geochemistry, contaminant, INEL, INEEL, and Idaho. In addition, a list of USGS documents that pertain to the INEEL was obtained and manually searched. The documents that appeared to be the most pertinent were selected from further review. These documents are tabulated in the citation list. This report summarizes existing geochemical conceptual models, but does not attempt to generate a new conceptual model or select the ''right'' model. This document is organized as follows. Geochemical models are described in general in Section 2. Geochemical processes that control the transport and fate of contaminants introduced into groundwater are described in Section 3. The natural geochemistry of the Eastern Snake River Plain Aquifer (SRPA) is described in Section 4. The effect of waste disposal on the INEEL subsurface is described in Section 5. The geochemical behavior of the major contaminants is described in Section 6. Section 7 describes the site-specific geochemical models developed for various INEEL facilities.

  14. Development and Application of a Paleomagnetic/Geochemical Method for Constraining the Timing of Burial Diagenetic and Fluid

    SciTech Connect (OSTI)

    Elmore, Richard D.; Engel, Michael H.

    2005-03-10T23:59:59.000Z

    Studies of diagenesis caused by fluid migration or other events are commonly hindered by a lack of temporal control. Our results to date demonstrate that a paleomagnetic/geochemical approach can be used to date fluid migration as well as burial diagenetic events. Our principal working hypothesis is that burial diagenetic processes (e.g., maturation of organic-rich sediments and clay diagenesis) and the migration of fluids can trigger the authigenesis of magnetic mineral phases. The ages of these events can be constrained by comparing chemical remanent magnetizations (CRMs) to independently established Apparent Polar Wander Paths. While geochemical (e.g. stable isotope and organic analyses) and petrographic studies provide important clues for establishing these relationships, the ultimate test of this hypothesis requires the application of independent dating methods to verify the paleomagnetic ages. Towards this end, we have used K-Ar dating of illitization as an alternative method for constraining the ages of magnetic mineral phases in our field areas.

  15. Geochemical characteristics of the Bulgarmarse Granite of the Fall River Pluton in the Avalonian Superterrane of southeastern New England

    SciTech Connect (OSTI)

    Mancuso, C.I.; Puffer, J.H. (Rutgers, The State Univ. of New Jersey, Newark, NJ (United States). Dept. of Geological Sciences)

    1993-03-01T23:59:59.000Z

    The 600 m.y. Bulgarmarsh Granite of the Fall River Pluton crops out along the SE margin of the Pennsylvanian-age Narragansett Basin in the Dedham terrane of the New England Avalonian Superterrane. The Bulgarmarsh is a coarse-grained, quartz-rich, very leucooratic granite, in which mafic minerals, generally less than 5--8%, occur chiefly as chlorite, biotite and garnet disequilibrium intergrowths. Most of the granite is very slightly deformed, but there are many localized zones of deformation, both brittle and plastic, that vary in degree of intensity. The Bulgarmarsh intrudes Basin margin metavolcanics similar to those of Price Neck Formation that crop out within the Basin in Newport and on Gould Island. The Bulgarmarsh Granite has many of the mineralogical and geochemical characteristics of an A-type granite. Its geochemistry places it in the post-orogenic classification of Maniar and Piccoli (1989). New major and minor element geochemical data clearly discriminate between the Bulgarmarsh Granite and the adjacent calc-alkaline Metacom Granite Gneiss. Avalonian Orogeny, occupying a place in geologic history similar to that of the Newport Granite.

  16. Preliminary delineation of natural geochemical reactions, Snake River Plain aquifer system, Idaho National Engineering Laboratory and vicinity, Idaho

    SciTech Connect (OSTI)

    Knobel, L.L.; Bartholomay, R.C.; Orr, B.R.

    1997-05-01T23:59:59.000Z

    The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, is conducting a study to determine the natural geochemistry of the Snake River Plain aquifer system at the Idaho National Engineering Laboratory (INEL), Idaho. As part of this study, a group of geochemical reactions that partially control the natural chemistry of ground water at the INEL were identified. Mineralogy of the aquifer matrix was determined using X-ray diffraction and thin-section analysis and theoretical stabilities of the minerals were used to identify potential solid-phase reactants and products of the reactions. The reactants and products that have an important contribution to the natural geochemistry include labradorite, olivine, pyroxene, smectite, calcite, ferric oxyhydroxide, and several silica phases. To further identify the reactions, analyses of 22 representative water samples from sites tapping the Snake River Plain aquifer system were used to determine the thermodynamic condition of the ground water relative to the minerals in the framework of the aquifer system. Principal reactions modifying the natural geochemical system include congruent dissolution of olivine, diopside, amorphous silica, and anhydrite; incongruent dissolution of labradorite with calcium montmorillonite as a residual product; precipitation of calcite and ferric oxyhydroxide; and oxidation of ferrous iron to ferric iron. Cation exchange reactions retard the downward movement of heavy, multivalent waste constituents where infiltration ponds are used for waste disposal.

  17. Geologic, geochemical, and geographic controls on NORM in produced water from Texas oil, gas, and geothermal reservoirs. Final report

    SciTech Connect (OSTI)

    Fisher, R.

    1995-08-01T23:59:59.000Z

    Water from Texas oil, gas, and geothermal wells contains natural radioactivity that ranges from several hundred to several thousand Picocuries per liter (pCi/L). This natural radioactivity in produced fluids and the scale that forms in producing and processing equipment can lead to increased concerns for worker safety and additional costs for handling and disposing of water and scale. Naturally occurring radioactive materials (NORM) in oil and gas operations are mainly caused by concentrations of radium-226 ({sup 226}Ra) and radium-228 ({sup 228}Ra), daughter products of uranium-238 ({sup 238}U) and thorium-232 ({sup 232}Th), respectively, in barite scale. We examined (1) the geographic distribution of high NORM levels in oil-producing and gas-processing equipment, (2) geologic controls on uranium (U), thorium (Th), and radium (Ra) in sedimentary basins and reservoirs, (3) mineralogy of NORM scale, (4) chemical variability and potential to form barite scale in Texas formation waters, (5) Ra activity in Texas formation waters, and (6) geochemical controls on Ra isotopes in formation water and barite scale to explore natural controls on radioactivity. Our approach combined extensive compilations of published data, collection and analyses of new water samples and scale material, and geochemical modeling of scale Precipitation and Ra incorporation in barite.

  18. Temperature-dependent pulsations of superfluid neutron stars

    E-Print Network [OSTI]

    M. E. Gusakov; N. Andersson

    2006-11-01T23:59:59.000Z

    We examine radial oscillations of superfluid neutron stars at finite internal temperatures. For this purpose we generalize the description of relativistic superfluid hydrodynamics to the case of superfluid mixtures. We show that in a neutron star at hydrostatic and beta-equilibrium the red-shifted temperature gradient is smoothed out by neutron superfluidity (but not by proton superfluidity). We calculate radial oscillation modes of neutron stars assuming "frozen" nuclear composition in the pulsating matter. The resulting pulsation frequencies show a strong temperature dependence in the temperature range (0.1-1) T_cn, where T_cn is the critical temperature of neutron superfluidity. Combining our results with thermal evolution, we obtain a significant evolution of the pulsation spectrum, associated with highly efficient Cooper pairing neutrino emission, for 20 years after superfluidity onset.

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

    SciTech Connect (OSTI)

    Jay L. Hirshfield

    2011-12-19T23:59:59.000Z

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

  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. Operational experience with CW high gradient and high QL cryomodules

    SciTech Connect (OSTI)

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

    2014-12-01T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Alberto Ramos; Stefan Sint

    2015-04-18T23:59:59.000Z

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

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

    SciTech Connect (OSTI)

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

    2013-12-01T23:59:59.000Z

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

  4. Evolution of aquatic insect behaviours across a gradient of disturbance predictability

    E-Print Network [OSTI]

    Evolution of aquatic insect behaviours across a gradient of disturbance predictability David A `sufficient'. At one extreme, large infrequent disturbances such as hurricanes and tsunamis may devastate

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

    E-Print Network [OSTI]

    Anders Forsgren

    2006-01-09T23:59:59.000Z

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

  6. 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...

  7. Sources of stress gradients in electrodeposited Ni MEMS.

    SciTech Connect (OSTI)

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

    2004-06-01T23:59:59.000Z

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

  8. Geochemical monitoring at Soultz-sous-Forts (France) between October 2006 and March 2007 1 EC Contract SES6-CT-2003-502706

    E-Print Network [OSTI]

    Boyer, Edmond

    presents the main results obtained during the geochemical monitoring of the fluids and deposits collected of the fractured areas, and recovering significant amounts of drilling wastes (grease, rests of cuttings), rock was initiated in 2001. Three wells, drilled at a depth of about 5000 m, must make up the heat exchanger. GPK-3

  9. Hydrologic and geochemical controls on soluble benzene migration in sedimentary basins

    E-Print Network [OSTI]

    Polly, David

    , a coupled ground- water flow and heat transfer model computes the hydraulic head, stream function, and temperature in the basin. A coupled mass transport model simulates water washing of benzene from an oil reservoir and its miscible, advective/dispersive transport by groundwater. Benzene mass transfer at the oil­water

  10. AQUIFER BIOTHERMOREMEDIATION USING HEAT PUMPS: SOUND THEORETICAL BASIS AND RESULTS ON THERMAL, GEOCHEMICAL AND

    E-Print Network [OSTI]

    Boyer, Edmond

    example, the long-term use of groundwater heat pumps for air conditioning of homes or buildings can induce and hydrogeological background. The presence of organic pollutants in the aquifer can amplify these phenomena/or the well productivity, (ii) an inappropriate temperature for the use of groundwater heat pumps for air

  11. Author's personal copy Methane seepage along the Hikurangi Margin of New Zealand: Geochemical

    E-Print Network [OSTI]

    Wehrli, Bernhard

    : Methane seepage gas hydrate water column sea surface carbon isotopes Hikurangi Margin The concentration and carbon isotope values of dissolved methane were measured in the water column at Rock Garden, Omakere­Temperature­Depth (CTD) operations were at Faure Site of Rock Garden. Here, seafloor bubble release was observed by ROV

  12. Actualistic and Geochemical Modeling of Reservoir Rock, CO2 and Formation Fluid Interaction, Citronelle Oil Field, Alabama

    SciTech Connect (OSTI)

    Weislogel, Amy

    2014-01-31T23:59:59.000Z

    This report includes description of the Citronelle field study area and the work carried out in the project to characterize the geology and composition of reservoir rock material and to collect an analyze the geochemical composition of produced fluid waters from the Citronelle field. Reservoir rock samples collected from well bore core were made into thin-sections and assessed for textural properties, including pore types and porosity distribution. Compositional framework grain modal data were collected via point-counting, and grain and cement mineralogy was assessed using SEM-EDS. Geochemistry of fluid samples is described and modeled using PHREEQC. Composition of rock and produced fluids were used as inputs for TOUGHREACT reactive transport modeling, which determined the rock-fluid system was in disequilibrium.

  13. Data Package of Samples Collected for Hydrogeologic and Geochemical Characterization: 300 Area RI/FS Sediment Cores

    SciTech Connect (OSTI)

    Lindberg, Michael J.; Bjornstad, Bruce N.; Lanigan, David C.; Williams, Benjamin D.

    2011-05-01T23:59:59.000Z

    This is a data package for sediment samples received from the 300 FF 5 OU. This report was prepared for CHPRC. Between August 16, 2010 and April 25, 2011 sediment samples were received from 300-FF-5 for geochemical studies. The analyses for this project were performed at the 331 building located in the 300 Area of the Hanford Site. The analyses were performed according to Pacific Northwest National Laboratory (PNNL) approved procedures and/or nationally recognized test procedures. The data sets include the sample identification numbers, analytical results, estimated quantification limits (EQL), and quality control data. The preparatory and analytical quality control requirements, calibration requirements, acceptance criteria, and failure actions are defined in the on-line QA plan 'Conducting Analytical Work in Support of Regulatory Programs' (CAW). This QA plan implements the Hanford Analytical Services Quality Assurance Requirements Documents (HASQARD) for PNNL.

  14. Coupling Hydrological and Geochemical Simulations to Assess Spatial Heterogeneity and Chemical Evolution of Groundwaters at Two Candidate Repository Sites in Sweden

    SciTech Connect (OSTI)

    Auque, Luis Francisco; Gimeno, Maria Jose; Gomez, Javier B. [Petrologia y Geoquimica, Universidad de Zaragoza, Depto. Ciencias de la Tierra, Facultad de Ciencias, c/ Pedro Cerbuna 12, Zaragoza, E-50009 (Spain); Puigdomenech, Ignasi [Safety and Science, Swedish Nuclear Fuel and Waste Management Co (SKB), Box 5864, Stockholm, SE-102 40 (Sweden)

    2007-07-01T23:59:59.000Z

    The chemical composition of groundwater surrounding a high level radioactive waste repository is of importance to many factors that affect repository performance. The geochemical characteristics of Swedish groundwater systems are governed by successive mixing events between several end-member waters during their paleogeographic evolution. An approach is proposed here to investigate the spatial and temporal evolution of groundwater geochemical conditions by coupling hydrogeological and geochemical models in a sequential way. The procedure combines hydrogeological results by others [1,2] of a discrete fracture network using CONNECTFLOW with a mixing and reaction-path simulation using PHREEQC. The hydrological results contain mixing proportions of four reference waters (a deep brine, glacial meltwater, marine water, and meteoric infiltration) at each time step and at every node of the 3D model domain. In this work, mixing fractions are fed into PHREEQC using software developed to build formatted input files and to extract the information from output files for subsequent plotting and analysis. The geochemical calculations included both chemical mixing and equilibrium reactions with selected minerals: calcite, chalcedony and an Fe(III) oxyhydroxide. Some results for the Forsmark site, about 170 km north of Stockholm, Sweden, are graphically presented. Cross sections, where each node is color-coded with respect to an important variable (pH, Eh or concentrations of main elements), are used to visualize the future evolution of the site. Sensitivity analyses were made to evaluate the effects of the different reactions and/or assumptions. The proposed methodology has proved useful for evaluating the future geochemical evolution of the repository sites and to increase the confidence in the site descriptions. (authors)

  15. REVIEW OF SCIENTIFIC INSTRUMENTS 83, 034704 (2012) Low temperature laser scanning microscopy of a superconducting

    E-Print Network [OSTI]

    Anlage, Steven

    2012-01-01T23:59:59.000Z

    Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, Virginia 23606, USA of achievable accelerating gradients, has been continuously improving over the years. Niobium, either as a thin in high-temperature superconductors (HTS).6 The origins of the technique go back to electron-beam heating7

  16. Cooled, temperature controlled electrometer

    DOE Patents [OSTI]

    Morgan, John P. (Idaho Falls, ID)

    1992-01-01T23:59:59.000Z

    A cooled, temperature controlled electrometer for the measurement of small currents. The device employs a thermal transfer system to remove heat from the electrometer circuit and its environment and dissipate it to the external environment by means of a heat sink. The operation of the thermal transfer system is governed by a temperature regulation circuit which activates the thermal transfer system when the temperature of the electrometer circuit and its environment exceeds a level previously inputted to the external variable temperature control circuit. The variable temperature control circuit functions as subpart of the temperature control circuit. To provide temperature stability and uniformity, the electrometer circuit is enclosed by an insulated housing.

  17. Cooled, temperature controlled electrometer

    DOE Patents [OSTI]

    Morgan, John P.

    1992-08-04T23:59:59.000Z

    A cooled, temperature controlled electrometer for the measurement of small currents. The device employs a thermal transfer system to remove heat from the electrometer circuit and its environment and dissipate it to the external environment by means of a heat sink. The operation of the thermal transfer system is governed by a temperature regulation circuit which activates the thermal transfer system when the temperature of the electrometer circuit and its environment exceeds a level previously inputted to the external variable temperature control circuit. The variable temperature control circuit functions as subpart of the temperature control circuit. To provide temperature stability and uniformity, the electrometer circuit is enclosed by an insulated housing.

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

    E-Print Network [OSTI]

    MPC for Wind Power Gradients -- Utilizing Forecasts, Rotor Inertia, and Central Energy Storage define an extremely low power output gradient and demonstrate how decentralized energy storage conservative bids on the power market. Energy storage strikes the major problems of wind power and joining

  19. MOSSBAUER SPECTRA IN THE PRESENCE OF A FLUCTUATING ELECTRIC l?IEI,D GRADIENT

    E-Print Network [OSTI]

    Boyer, Edmond

    MOSSBAUER SPECTRA IN THE PRESENCE OF A FLUCTUATING ELECTRIC l?IEI,D GRADIENT A. GERARD and F, un mod61e de calcul des spectres Mossbauer en presence d'un gradient de champ electrique fluctuant Recherchesdu F. N. R. S. MAGNETIC INTERACTIONS IN GOLD (11)-BIS (MALEONITRILEDITHIOLATE) OBSERVED BY lg7AuMOSSBAUER

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

    E-Print Network [OSTI]

    Ruby, Edward G.

    by Cesium Chloride Gradient Centrifugation Patricia N. Lee1,2 , Margaret J. McFall-Ngai3 , Patrick Callaerts from adult bobtail squid (Euprymna scolopes) tissues by cesium chloride (CsCl) gradient centrifugation modifications of nucleic acids are inhibited by these contaminants. The method described here yields high

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

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

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

  2. A THz Coaxial Two-Channel Dielectric Wakefield Structure for High Gradient Acceleration

    SciTech Connect (OSTI)

    Marshall, T. C. [Columbia University, New York, NY (United States); Omega-P, Inc., New Haven, CT (United States); Sotnikov, G. V. [Omega-P, Inc., New Haven, CT (United States); NSC Kharkov Institute of Physics and Technology, Kharkov (Ukraine); Hirshfield, J. L. [Omega-P, Inc., New Haven, CT (United States); Yale University, New Haven, CT (United States)

    2010-11-04T23:59:59.000Z

    A coaxial two-channel dielectric wakefield structure is examined for use as a high gradient accelerator. A THz design, having radius {approx}1 mm, is shown to provide GeV/m--level acceleration gradient, high transformer ratio, and stable accelerated bunch motion when excited by a stable-moving 5-GeV 6-nC annular drive bunch.

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

    E-Print Network [OSTI]

    Malhi, Yadvinder

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

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

    E-Print Network [OSTI]

    Claridge, Ela

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

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

    E-Print Network [OSTI]

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

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

    E-Print Network [OSTI]

    Vallino, Joseph J.

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

  7. Ionosphere Spatial Gradient Threat for LAAS: Mitigation and Tolerable Threat Space

    E-Print Network [OSTI]

    Stanford University

    1 Ionosphere Spatial Gradient Threat for LAAS: Mitigation and Tolerable Threat Space Ming Luo, Sam and a threat space was extrapolated based on the 6 April 2000 ionospheric storm. It was showed that the impact of the ionospheric anomalies depends on the threat parameters, namely, the ionospheric gradient, the slope width

  8. Gradient-based optimization of mother wavelets Nicola Neretti Nathan Intrator

    E-Print Network [OSTI]

    Intrator, Nathan

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

  9. The gradient flow running coupling in SU2 with 8 flavors

    E-Print Network [OSTI]

    Jarno Rantaharju; Tuomas Karavirta; Viljami Leino; Teemu Rantalaiho; Kari Rummukainen; Kimmo Tuominen

    2014-11-18T23:59:59.000Z

    We present preliminary results of the gradient flow running coupling with Dirichlet boundary condition in the SU(2) gauge theory with 8 fermion flavours. Improvements to the gradient flow measurement allow us to obtain a robust continuum limit. The results are consistent with perturbative running in the weak coupling region.

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

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

  11. An investigation of the effect of pore scale flow on average geochemical reaction rates using direct numerical simulation

    SciTech Connect (OSTI)

    Rafa, S. Molins; Trebotich, D.; Steefel, C. I.; Shen, C.

    2012-02-01T23:59:59.000Z

    The scale-dependence of geochemical reaction rates hinders their use in continuum scale models intended for the interpretation and prediction of chemical fate and transport in subsurface environments such as those considered for geologic sequestration of CO{sub 2}. Processes that take place at the pore scale, especially those involving mass transport limitations to reactive surfaces, may contribute to the discrepancy commonly observed between laboratory-determined and continuum-scale or field rates. Here, the dependence of mineral dissolution rates on the pore structure of the porous media is investigated by means of pore scale modeling of flow and multicomponent reactive transport. The pore scale model is comprised of high performance simulation tools and algorithms for incompressible flow and conservative transport combined with a general-purpose multicomponent geochemical reaction code. The model performs direct numerical simulation of reactive transport based on an operator-splitting approach to coupling transport and reactions. The approach is validated with a Poiseuille flow single-pore experiment and verified with an equivalent 1D continuum-scale model of a capillary tube packed with calcite spheres. Using the case of calcite dissolution as an example, the high resolution model is used to demonstrate that non-uniformity in the flow field at the pore scale has the effect of decreasing the overall reactivity of the system, even when systems with identical reactive surface area are considered. The effect becomes more pronounced as the heterogeneity of the reactive grain packing increases, particularly where the flow slows sufficiently such that the solution approaches equilibrium locally and the average rate becomes transport-limited.

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

    SciTech Connect (OSTI)

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

    2012-07-03T23:59:59.000Z

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

  13. 4D STUDY OF STRAIN GRADIENTS EVOLUTION IN TWINNED NiMnGa SINGLE CRYSTALS UNDER MAGNETIC FIELD

    SciTech Connect (OSTI)

    Barabash, Rozaliya [ORNL; Xu, Ruqing [Argonne National Laboratory (ANL); Barabash, Oleg M [ORNL; Sozinov, Alexei [AdaptaMat, Finland

    2014-01-01T23:59:59.000Z

    Time-resolved 3D X-ray microscopy with a submicron beam size was used to follow the evolution of strains in off-stoichiometric NiMnGa twinned crystals near type I (hard) twin boundary under magnetic field. Laminate A/B microstructure was revealed near the twin boundaries in A variant. Large strain gradients are observed in the C variant in the immediate vicinity of the type I twin boundary: the lattice is under large tensile strains ~0.4% along the c- axes within first micron. Distinct a and b lattice parameter evolution with temperature and magnetic field is demonstrated. In an applied magnetic field the strain field was observed at larger distances from the twin boundary and becomes more complex. Stochastic twin boundary motion was observed after the magnetic field reaches a certain critical value.

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

    SciTech Connect (OSTI)

    Gobet, Mallory [Hunter College of the City University of New York] [Hunter College of the City University of New York; Greenbaum, Steve [Hunter College of the City University of New York] [Hunter College of the City University of New York; Sahu, Gayatri [ORNL] [ORNL; Liang, Chengdu [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    The ceramic lithium ion conductor -Li3PS4 has a disordered and nanoporous structure that leads to an enhancement in ionic conductivity by some three orders of magnitude compared to the crystalline phase. The phase is prepared by thermal treatment of an inorganic-organic complex based on Li3PS4 and THF. Multinuclear (1H, 6,7Li, 31P) solid state NMR spectroscopy is used to characterize the structural phase evolution of the starting material at various steps in the thermal treatment. The phase formed after high temperature treatment is recognized as spectroscopically distinct from the bulk -Li3PS4 compound. Also formed is an amorphous lithium thiophosphate phase that is metastable as verified by annealing over an extended period. Lithium ion self-diffusion coefficients are measurable by standard pulsed gradient NMR methods at 100oC and with values consistent with the high ionic conductivity previously reported for this material.

  15. 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.

  16. Gradient flow and scale setting on MILC HISQ ensembles

    E-Print Network [OSTI]

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

    2015-01-01T23:59:59.000Z

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

  17. Analysis Code for High Gradient Dielectric Insulator Surface Breakdown

    SciTech Connect (OSTI)

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

    2010-05-30T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    A. B. Morcos

    2004-12-08T23:59:59.000Z

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

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

    SciTech Connect (OSTI)

    Kathy Lu; Christopher Story; W.T. Reynolds

    2007-12-21T23:59:59.000Z

    Solid oxide fuel cells (SOFC) hold great promise for clean power generation. However, high temperature stability and long term durability of the SOFC components have presented serious problems in SOFC technological advancement and commercialization. The seals of the fuel cells are the most challenging area to address. A high temperature gas seal is highly needed which is durable against cracking and gas leakage during thermal cycling and extended operation. This project investigates a novel composite seal by integrating 3D printed shape memory alloy (SMA) wires into a glass matrix. The SMA we use is TiNiHf and the glass matrix we use is SrO-La{sub 2}O{sub 3}-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3}-SiO{sub 2} (SLABS). Dilatometry shows to be an extremely useful tool in providing the CTEs. It pinpoints regions of different CTEs under simulated SOFC thermal cycles for the same glass. For the studied SLABS glass system, the region with the greatest CTE mismatch between the glass seal and the adjacent components is 40-500 C, the typical heating and cooling regions for SOFCs. Even for low temperature SOFC development, this region is still present and needs to be addressed. We have demonstrated that the proposed SLABS glass has great potential in mitigating the thermal expansion mismatch issues that are limiting the operation life of SOFCs. TiNiHf alloy has been successfully synthesized with the desired particle size for the 3DP process. The TiNiHf SMA shape memory effect very desirably overlaps with the problematic low CTE region of the glass. This supports the design intent that the gradient structure transition, phase transformation toughening, and self-healing of the SMA can be utilized to mitigate/eliminate the seal problem. For the 3DP process, a new binder has been identified to match with the specific chemistry of the SMA particles. This enables us to directly print SMA particles. Neutron diffraction shows to be an extremely useful tool in providing information regarding the austenite to martensite phase transformation, SMA alloy lattice constant change, and the corresponding thermal stress from the glass matrix. It pinpoints regions of SMA phase transformation and the thermal stress effect under simulated SOFC thermal cycles. The bilayer test shows that there is still much work to be done for the proper integration of the seal components. Large scale production should lower the cost associated with the proposed approach, especially on the raw material cost and 3D printing.

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

    E-Print Network [OSTI]

    Jahns, Jürgen

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