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Note: This page contains sample records for the topic "temperature gradient geochemical" from the National Library of EnergyBeta (NLEBeta).
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1

Ion temperature gradient instability and anomalous transport  

SciTech Connect

This report discusses experiments in ion temperature gradient instability and anomalous transport in the CLM steady state device. (LSP).

Sen, A.K.

1991-08-01T23:59:59.000Z

2

Short wavelength ion temperature gradient turbulence  

Science Conference Proceedings (OSTI)

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

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

2012-10-15T23:59:59.000Z

3

Program predicts reservoir temperature and geothermal gradient  

Science Conference Proceedings (OSTI)

This paper reports that a Fortran computer program has been developed to determine static formation temperatures (SFT) and geothermal gradient (GG). A minimum of input data (only two shut-in temperature logs) is required to obtain the values of SFT and GG. Modeling of primary oil production and designing enhanced oil recovery (EOR) projects requires knowing the undisturbed (static) reservoir temperature. Furthermore, the bottom hole circulating temperature (BHCT) is an important factor affecting a cement's thickening time, rheological properties, compressive strength, development, and set time. To estimate the values of BHCT, the geothermal gradient should be determined with accuracy. Recently we obtained an approximate analytical solution which describes the shut-in temperature behavior.

Kutasov, I.M.

1992-06-01T23:59:59.000Z

4

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

DOE Green Energy (OSTI)

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.

Levitte, D.; Gambill, D.T.

1980-11-01T23:59:59.000Z

5

The Response of a Uniform Horizontal Temperature Gradient to Heating  

Science Conference Proceedings (OSTI)

The response of a uniform horizontal temperature gradient to prescribed fixed heating is calculated in the context of an extended version of surface quasigeostrophic dynamics. It is found that for zero mean surface flow and weak cross-gradient ...

Maarten H. P. Ambaum; Panos J. Athanasiadis

2007-10-01T23:59:59.000Z

6

Surface Temperature Gradients as Diagnostic Indicators of Midlatitude Circulation Dynamics  

Science Conference Proceedings (OSTI)

Zonal and meridional surface temperature gradients are considered to be determinants of large-scale atmospheric circulation patterns. However, there has been limited investigation of these gradients as diagnostic aids. Here, the twentieth-century ...

Christina Karamperidou; Francesco Cioffi; Upmanu Lall

2012-06-01T23:59:59.000Z

7

Nonequilibrium thermodynamics of temperature gradient metamorphism in snow.  

E-Print Network (OSTI)

??In the presence of a sufficient temperature gradient, snow evolves from an isotropic network of ice crystals to a transversely isotropic system of depth hoar… (more)

Staron, Patrick Joseph.

2013-01-01T23:59:59.000Z

8

Field Investigations And Temperature-Gradient Drilling At Marine Corps  

Open Energy Info (EERE)

Investigations And Temperature-Gradient Drilling At Marine Corps Investigations And Temperature-Gradient Drilling At Marine Corps Air-Ground Combat Center (Mcagcc), Twenty-Nine Palms, Ca Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Field Investigations And Temperature-Gradient Drilling At Marine Corps Air-Ground Combat Center (Mcagcc), Twenty-Nine Palms, Ca Details Activities (4) Areas (1) Regions (0) Abstract: The U.S. Navy's Geothermal Program Office (GPO) has been conducting geothermal exploration activities in the Camp Wilson area of Marine Corps Air-Ground Combat Center (MCAGCC), Twenty-nine Palms, CA, for almost two years. Work has included self-potential (SP) surveys, fault structure analyses using LiDAR surveys, and drilling and assessment of five (5) temperature-gradient holes. For several decades the GPO has worked

9

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

Open Energy Info (EERE)

years. Work has included self-potential (SP) surveys, fault structure analyses using LiDAR surveys, and drilling and assessment of five (5) temperature-gradient holes. For...

10

Streamer formation in plasma with a temperature gradient  

SciTech Connect

Turbulence produced by a temperature gradient in a collisional plasma is investigated. The system evolves to a state in which highly elongated streams of plasma move up and down the temperature gradient. The resulting transport greatly exceeds estimates based on mixing length arguments. It is argued that such streams are the preferred nonlinear state of turbulent fluctuations driven by both delT/sub e/ and delT/sub i/.

Drake, J.F.; Guzdar, P.N.; Hassam, A.B.

1988-11-07T23:59:59.000Z

11

An Expression for the Temperature Gradient in Chaotic Fields  

SciTech Connect

A coordinate system adapted to the invariant structures of chaotic magnetic fields is constructed. The coordinates are based on a set of ghost-surfaces, defined via an action-gradient flow between the minimax and minimizing periodic orbits. The construction of the chaotic coordinates allows an expression describing the temperature gradient across a chaotic magnetic field to be derived. The results are in close agreement with a numerical calculation.

S.R. Hudson

2008-12-22T23:59:59.000Z

12

Geology and Temperature Gradient Surveys Blue Mountain Geothermal  

Open Energy Info (EERE)

Geology and Temperature Gradient Surveys Blue Mountain Geothermal Geology and Temperature Gradient Surveys Blue Mountain Geothermal Discovery, Humboldt County, Nevada Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Geology and Temperature Gradient Surveys Blue Mountain Geothermal Discovery, Humboldt County, Nevada Abstract Triassic argillite and sandstone of the Grass Valley Formation and phyllitic mudstone of the overlying Raspberry Formation, also of Triassic age, host a blind geothermal system under exploration by Blue Mountain Power Company Inc. with assistance from the Energy & Geoscience Institute. Geologically young, steeply dipping, open fault sets, striking N50-60°E,N50-60°W, and N-S intersect in the geothermal zone providing deep permeability over a wide area. Extensive silicification andhydro

13

Oil displacement through a porous medium with a temperature gradient  

E-Print Network (OSTI)

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

Oliveira, C L N; Herrmann, H J

2011-01-01T23:59:59.000Z

14

Temperature-gradient and heat flow data, Grass Valley, Nevada  

DOE Green Energy (OSTI)

A series of 16 shallow and intermediate-depth temperature-gradient holes were drilled for Sunoco Energy Development Co. in Grass Valley, Pershing County, Nevada, on leases held by Aminoil USA, Inc., under the cost-sharing industry-linked program of the Department of Energy. Thirteen shallow (85-152 m) and 3 intermediate-depth (360-457 m) holes were completed and logged during the period June through September, 1979. The locations of these holes and of pre-existing temperature-gradient holes are shown on plate 1. This report constitutes a final data transmittal and disclosure of results. The drilling subcontractor was Southwest Drilling and Exploration, Inc. of Central, Utah. They provided a Gardner-Denver 15W rig, a 3-man crew, and supporting equipment. A l l holes were drilled with mud as the circulating medium. Drilling histories for each hole are summarized in table 1. GeothermEx, Inc. performed on-site geological descriptions of the cuttings; obtained several temperature profiles for each hole, including an equilibrium profile taken 23 days or more after cessation of drilling; selected samples for thermal conductivity measurements; integrated temperature, temperature-gradient, and heat-flow data obtained in this project with published values; and prepared this report.

Koenig, James B.; Gardner, Murray C.

1979-11-01T23:59:59.000Z

15

How temperature gradients are determined in toroidal plasmas  

SciTech Connect

It is commonly assumed in modern-day toroidal plasmas that the edge ion or electron temperature is sufficiently low so that the edge temperature can be neglected with respect to the center temperature. For example, in a detached plasma, where the boundary condition is understood reasonably well, it is both theoretically and experimentally justified to say that the edge temperature can be approximately zero. Now in a toroidal plasma bounded by a divertor, it is theoretically possible to design a divertor such that each pair of electron and hydrogen ion can carry, on average, 3/2(kTe + kTi). Then, in the absence of recycling, the temperature gradients in the scrape-off layer can be made zero or at least, less than 1/a, where a is the plasma radius. Under that boundary condition, the temperature gradient inside the plasma vanishes. Realizing this in practice is difficult but not impossible. The problem is discussed in this paper. 1 ref.

Yoshikawa, Shoichi.

1990-02-01T23:59:59.000Z

16

Production and identification of the ion-temperature-gradient instability  

SciTech Connect

In order to produce and study the ion-temperature-gradient instability, the Columbia Linear Machine has been modified to yield a peaked ion temperature and flattish density profiles. Under these conditions the parameter {eta}{sub {ital i}} (={ital d} ln{ital T}{sub {ital i}}/{ital d} ln{ital N}) exceeded the critical value and a strong instability has been observed. Further identification has been based on observation of the azimuthal and axial wavelengths, and the real frequency, appropriate for the mode.

Sen, A.K.; Chen, J.; Mauel, M. (Plasma Research Laboratory, Columbia University, New York, New York 10027 (US))

1991-01-28T23:59:59.000Z

17

Manipulation of Colloids by Nonequilibrium Depletion Force in Temperature Gradient  

E-Print Network (OSTI)

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

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

2009-02-24T23:59:59.000Z

18

Electron geodesic acoustic modes in electron temperature gradient mode turbulence  

Science Conference Proceedings (OSTI)

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

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

2012-08-15T23:59:59.000Z

19

Mechanisms Controlling Variability of the Interhemispheric Sea Surface Temperature Gradient in the Tropical Atlantic  

Science Conference Proceedings (OSTI)

The seasonal evolution of sea surface temperature (SST) fields in the tropical Atlantic is explored for composites of extremely STRONG and WEAK northward SST gradients, because these are known to control the basinwide pressure gradient, latitude ...

Richard G. Wagner

1996-09-01T23:59:59.000Z

20

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

SciTech Connect

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.

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

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


21

A Simple Model of a Convectively Coupled Walker Circulation Using the Weak Temperature Gradient Approximation  

Science Conference Proceedings (OSTI)

An idealized model of a Walker circulation based on the weak temperature gradient (WTG) approximation and a single baroclinic vertical mode for all fields is analyzed. The circulation is forced by a sinusoidal variation of sea surface temperature ...

Christopher S. Bretherton; Adam H. Sobel

2002-10-01T23:59:59.000Z

22

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

E-Print Network (OSTI)

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

White, Anne E.

23

Changes in Zonal Surface Temperature Gradients and Walker Circulations in a Wide Range of Climates  

Science Conference Proceedings (OSTI)

Variations in zonal surface temperature gradients and zonally asymmetric tropical overturning circulations (Walker circulations) are examined over a wide range of climates simulated with an idealized atmospheric general circulation model (GCM). ...

Timothy M. Merlis; Tapio Schneider

2011-09-01T23:59:59.000Z

24

On the maintenance of weak meridional temperature gradients during warm climates  

E-Print Network (OSTI)

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

Korty, Robert Lindsay

2005-01-01T23:59:59.000Z

25

An Effective, Economic, Aspirated Radiation Shield for Air Temperature Observations and Its Spatial Gradients  

Science Conference Proceedings (OSTI)

This paper presents the design and evaluates the performance of a double-walled electrically aspirated radiation shield for thermometers measuring air temperature and its gradients in the atmospheric surface layer. Tests were performed to quantify ...

Christoph K. Thomas; Alexander R. Smoot

2013-03-01T23:59:59.000Z

26

Reorganization of Tropical Climate during El Niño: A Weak Temperature Gradient Approach  

Science Conference Proceedings (OSTI)

The applicability of a weak temperature gradient (WTG) formulation for the reorganization of tropical climate during El Niño–Southern Oscillation (ENSO) events is investigated. This idealized dynamical framework solves for the divergent portion ...

Benjamin R. Lintner; John C. H. Chiang

2005-12-01T23:59:59.000Z

27

Sounding the Skin of Water: Sensing Air–Water Interface Temperature Gradients with Interferometry  

Science Conference Proceedings (OSTI)

Evidence for the radiometric determination of air–water interface temperature gradients is presented. Inherent radiometric characteristics in the water molecule cause variations in the absorption coefficient that allow radiation at near-infrared ...

W. McKeown; F. Bretherton; H. L. Huang; W. L. Smith; H. L. Revercomb

1995-12-01T23:59:59.000Z

28

A method for filtering hot spring noise from shallow temperature gradient data  

Science Conference Proceedings (OSTI)

A technique for separating shallow heat source effects from temperature gradient data is presented. The technique makes use of the depth dependent information available in the wave number spectrum of the gradient data. The effectiveness of the technique is demonstrated on a two-dimensional numerical model of a geothermal system containing a deep geothermal reservoir which is masked by a warm, shallow aquifer and a thermal spring. This geothermal system is representative of those found throughout the Basin and Range province. The resulting filtered gradients produce an excellent prediction of the temperatures in the modeled geothermal reservoir.

Li, T.M.C.; Chandler, C.A.; Ferguson, J.F.

1982-10-01T23:59:59.000Z

29

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

DOE Green Energy (OSTI)

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

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

1981-08-01T23:59:59.000Z

30

Heat conductance in nonlinear lattices at small temperature gradients  

E-Print Network (OSTI)

This paper proposes a new methodological framework within which the heat conductance in 1D lattices can be studied. The total process of heat conductance is separated into two parts where the first one is the equilibrium process at equal temperatures $T$ of both ends and the second one -- non-equilibrium with the temperature $\\Delta T$ of one end and zero temperature of the other. This approach allows significant decrease of computational time at $\\Delta T \\to 0$. The threshold temperature $T_{\\rm thr}$ is found which scales $T_{\\rm thr}(N) \\sim N^{-3}$ with the lattice size $N$ and by convention separates two mechanisms of heat conductance: phonon mechanism dominates at $T T_{\\rm thr}$. Solitons and breathers are directly visualized in numerical experiments. The problem of heat conductance in non-linear lattices in the limit $\\Delta T \\to 0$ can be reduced to the heat conductance of harmonic lattice with time-dependent stochastic rigidities determined by the equilibrium process at temperature $T$. The detailed analysis is done for the $\\beta$-FPU lattice though main results are valid for one-dimensional lattices with arbitrary potentials.

T. Yu. Astakhova; V. N. Likhachev; G. A. Vinogradov

2010-06-09T23:59:59.000Z

31

Phase-field modeling of temperature gradient driven pore migration coupling with thermal conduction  

SciTech Connect

Pore migration in a temperature gradient (Soret effect) is investigated by a phase-field model coupled with a heat transfer calculation. Pore migration is observed towards the high temperature domain with velocities that agree with analytical solution. Due to the low thermal conductivity of the pores, the temperature gradient across individual pores is increased, which in turn, accelerates the pore migration. In particular, for pores filled with xenon and helium, the pore velocities are increased by a factor of 2.2 and 2.1, respectively. A quantitative equation is then derived to predict the influence of the low thermal conductivity of pores.

Liangzhe Zhang; Michael R Tonks; Paul C Millett; Yongfeng Zhang; Karthikeyan Chockalingam; Bulent Biner

2012-04-01T23:59:59.000Z

32

Homogeneous Quasi-Geostrophic Turbulence Driven by a Uniform Temperature Gradient  

Science Conference Proceedings (OSTI)

Statistically steady states consistent with a horizontally uniform time-averaged temperature gradient in a two-layer quasi-geostrophic model on a beta-plane are found by numerically integrating the equations for deviations from this mean state in ...

Dale B. Haidvogel; Isaac M. Held

1980-12-01T23:59:59.000Z

33

Evaluating the effects of temperature gradients and currents nonuniformity in on-chip interconnects  

Science Conference Proceedings (OSTI)

The paper provides a compact but accurate electro-thermal model of a long wiring on-chip interconnect embedded in the complex layout of a ULSI digital circuit. The proposed technique takes into account both the effect of temperature gradients over the ... Keywords: Current nonuniformity, Electro-thermal model, On-chip interconnect, Propagation delay

N. Spennagallo; L. Codecasa; D. D'Amore; P. Maffezzoni

2009-07-01T23:59:59.000Z

34

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

SciTech Connect

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

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

2011-12-01T23:59:59.000Z

35

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

Science Conference Proceedings (OSTI)

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

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

2011-10-07T23:59:59.000Z

36

Comparative studies of geothermal surveys in 3-meter and temperature-gradient holes  

Science Conference Proceedings (OSTI)

The reliability of conducting temperature surveys within the upper 3 meters of the surface to map geothermal anomalies is demonstrated in experiments at two prospects in which deeper gradient hole data were obtained. The 3m temperatures faithfully outlined the thermal anomaly at McCoy, Nevada; and in Dixie Valley, NV 3m surveys reproduced and detailed patterns derived from 40m data. These encouraging results led to the development of multi-thermistor strings for logging the seasonal wave within the upper 3 meters. From many such logs, diffusivity variations can be detected, which might otherwise be misconstrued as thermal anomalies. The technique is demonstrated by a typical Basin-Range reconnaissance project. As many as 10 or more 3m holes can be emplaced in the time required for a conventional gradient well, and with considerably less impact on the environment.

Lang, A.L.; Deymonaz, J.; Pilkington, H.D.

1982-10-01T23:59:59.000Z

37

Downward continuation of temperature gradients at MacFarlane's Hot Spring, Northern Nevada  

SciTech Connect

MacFarlane's Hot Spring is located on the eastern margin of the Black Rock Desert of northwest Nevada. Detailed temperature logs from thirty-eight shallow boreholes (500 feet) and six intermediate depth boreholes (1500-2000 feet) have been used to construct a temperature gradient contour map covering approximately 144 square miles, both within and adjacent to the geothermal area. These temperature gradients were then continued downward through a detailed conductivity model to complete the threedimensional thermal picture. The principal results are as follows: The maximum measured temperature is 178/sup 0/F at 2,000 feet, and the maximum projected temperatures at greater depths are not likely to exceed the 250-350/sup 0/F range. The area of hydrothermal activity is confined to the western front of a structural platform bounded by two roughly parallel normal faults. The anomaly is best explained in terms of a simple groundwater flow model. The groundwater flows west through the structural platform and ascends when it intersects the conduit provided by the fault. The faults on the eastern side of the platform permit recharge to the system.

Swanberg, C.A.; Bowers, R.L.

1982-10-01T23:59:59.000Z

38

Application of high temperature superconductors to high-gradient magnetic separation  

Science Conference Proceedings (OSTI)

High Gradient Magnetic Separation (HGMS) is a powerful technique which can be used to separate widely dispersed contaminants from a host material, This technology can separate magnetic solids from other solids, liquids or gases. As the name implies HGMS uses large magnetic field gradients to separate ferromagnetic and paramagnetic particles. HGMS separators usually consist of a high-field solenoid magnet, the bore of which contains a fine-structured, ferromagnetic matrix material. The matrix material locally distorts the magnetic field and creates large field gradients in the vicinity of the matrix elements. These elements then become trapping sites for magnetic particles and are the basis for the magnetic separation. In this paper we discuss the design and construction of a prototype HGMS unit using a magnet made with high temperature superconductors (HTS). The prototype consists of an outer vacuum vessel which contains the HTS solenoid magnet The magnet is surrounded by a thermal radiation shield and multilayer insulation (MLI) blankets. The magnet, thermal shield and current leads all operate in a vacuum and are cooled by a cryocooler. High temperature superconducting current leads are used to reduce the heat leak from the ambient environment to the HTS magnet.

Daugherty, M.A.; Prenger, F.C.; Hill, D.D.; Daney, D.E.; Worl, L.W.; Schake, A.R.; Padilla, D.D.

1994-06-01T23:59:59.000Z

39

Calculation of equilibria at elevated temperatures using the MINTEQ geochemical code  

DOE Green Energy (OSTI)

Coefficients and equations for calculating mineral hydrolysis constants, solubility products and formation constants for 60 minerals and 57 aqueous species in the 13 component thermodynamic system K/sub 2/O-Na/sub 2/O-CaO-MgO-FeO-Al/sub 2/O/sub 3/-SiO/sub 2/-CO/sub 2/-H/sub 2/O-HF-HCl-H/sub 2/S-H/sub 2/SO/sub 4/ are presented in a format suitable for inclusion in the MINTEQ computer code. The temperature functions presented for minerals are based on the MINTEQ data base at 25/degree/C and the integration of analytical heat capacity power functions. This approach ensures that the temperature functions join smoothly with the low-temperature data base. A new subroutine, DEBYE, was added to MINTEQ that is used to calculate the theoretical Debye-Hueckel parameters A and B as a function of temperature. In addition, this subroutine also calculates a universal value of the extended Debye-Hueckel parameter, b/sub i/, as a function of temperature. The coefficients and equations provide the capability to use MINTEQ to more accurately calculate water/rock equilibrium for temperatures of up to 250/degree/C, and in dilute, low-sulfate, near neutral groundwaters to 300/degree/C. 52 refs., 1 fig., 6 tabs.

Smith, R.W.

1988-12-01T23:59:59.000Z

40

On the Role of Sea Surface Temperature Gradients in Forcing Low-Level Winds and Convergence in the Tropics  

Science Conference Proceedings (OSTI)

We examine the importance of pressure gradients due to surface temperature gradients to low-level (p ? 700 mb) flow and convergence in the tropics over time scales 1 month. The latter plays a crucial role in determining the distribution of ...

Richard S. Lindzen; Sumant Nigam

1987-09-01T23:59:59.000Z

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


41

Application of the Wigner–Ville Distribution to Temperature Gradient Microstructure: A New Technique to Study Small-Scale Variations  

Science Conference Proceedings (OSTI)

The Wigner–Ville distribution, a new tool in the time–frequency analysis of signals, is applied to temperature gradient microstructure records. In particular, the Wigner–Ville distribution is used to compute the local instantaneous and maximum ...

Jörg Imberger; Boualem Boashash

1986-12-01T23:59:59.000Z

42

Influences of Sea Surface Temperature Gradients and Surface Roughness Changes on the Motion of Surface Oil: A Simple Idealized Study  

Science Conference Proceedings (OSTI)

The authors' modeling shows that changes in sea surface temperature (SST) gradients and surface roughness between oil-free water and oil slicks influence the motion of the slick. Physically significant changes occur in surface wind speed, surface ...

Yangxing Zheng; Mark A. Bourassa; Paul Hughes

2013-07-01T23:59:59.000Z

43

Relative Roles of Elevated Heating and Surface Temperature Gradients in Driving Anomalous Surface Winds over Tropical Oceans  

Science Conference Proceedings (OSTI)

Elevated heating by cumulus convection and sea surface temperature gradients are both thought to contribute to surface winds over tropical oceans. The relative strength and role of each mechanism is examined by imposing forcing derived from data ...

John C. H. Chiang; Stephen E. Zebiak; Mark A. Cane

2001-06-01T23:59:59.000Z

44

The Influence of Ocean Surface Temperature Gradient and Continentality on the Walker Circulation. Part I: Prescribed Tropical Changes  

Science Conference Proceedings (OSTI)

A coarse-mesh, global climate model developed at the Goddard Institute for Space Studies (GISS) has been used to assess the influence of ocean surface temperature (OST) gradient and continentality on the Walker circulation. The basic model ...

Robert M. Chervin; Leonard M. Druyan

1984-08-01T23:59:59.000Z

45

The momentum flux probability distribution function for ion-temperature-gradient turbulence  

SciTech Connect

There has been overwhelming evidence that coherent structures play a critical role in determining the overall transport in a variety of systems. We compute the probability distribution function (PDF) tails of momentum flux and heat flux in ion-temperature-gradient turbulence, by taking into account the interaction among modons, which are assumed to be coherent structures responsible for bursty and intermittent events, contributing to the PDF tails. The tail of PDF of momentum flux R= is shown to be exponential with the form exp(-{xi}R{sup 3/2}), which is broader than a Gaussian, similar to what was found in the previous local studies. An analogous expression with the same functional dependence is found for the PDF tails of heat flux. Furthermore, we present a detailed numerical study of the dependence of the PDF tail on the temperature and density scale lengths and other physical parameters through the coefficient {xi}.

Anderson, Johan; Kim, Eun-jin [University of Sheffield, Department of Applied Mathematics, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

2008-05-15T23:59:59.000Z

46

Estimation of in-situ thermal conductivities from temperature gradient measurements  

Science Conference Proceedings (OSTI)

A mathematical model has been developed to study the effect of variable thermal conductivity of the formations, and the wellbore characteristics, on the fluid temperature behavior inside the wellbore during injection or production and after shut-in. During the injection or production period the wellbore fluid temperature is controlled mainly by the fluid flow rate and the heat lost from the fluid to the formation. During the shut-in period, the fluid temperature is strongly affected by differences in the formation thermal conductivities. Based on the results of the present analysis, two methods for estimating in-situ thermal conductivity were derived. First, the line source concept is extended to estimate values of the formation thermal conductivities utilizing the fluid temperature record during the transient period of injection or production and shut-in. The second method is applied when a well is under thermal equilibrium conditions. Values of the formation thermal conductivities can also be estimated by using a continuous temperature gradient log and by measuring the thermal conductivity of the formation at a few selected wellbore locations.

Hoang, V.T.

1980-12-01T23:59:59.000Z

47

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

SciTech Connect

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.

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

1983-12-15T23:59:59.000Z

48

Kinetic resonance damping rate of the toroidal ion temperature gradient mode  

Science Conference Proceedings (OSTI)

The linear damping rates of the toroidal ion temperature gradient ({eta}{sub i}) mode due to the toroidal resonance are calculated in the local kinetic limit. The well-known Landau contour method is generalized to treat the analytic continuation problem of the guiding center dispersion function in the toroidal resonance system where the resonance occurs from both the magnetic {Delta}B-curvature drift and the parallel ion transit drift. A detailed numerical analysis is presented for the dependence of the damping rate of the toroidal {eta}{sub i} mode on various parameters such as {var_epsilon}{sub n}, {kappa}{sub y}, and the trapped electron fraction. In addition, a consideration is presented on the decay problem of the ballistic response by the phase mixing in the toroidal system, which is directly related to the present damping problem of the wave normal modes by the toroidal resonance.

Kim, J.Y.; Kishimoto, Y.; Horton, W.; Tajima, T.

1993-09-01T23:59:59.000Z

49

HIGH TEMPERATURE OXIDATION/CORROSION BEHAVIOR OF METALS AND ALLOYS UNDER A HYDROGEN GRADIENT  

Science Conference Proceedings (OSTI)

Metallic interconnects in SOFC stacks, perform in challenging environment, as they are simultaneously exposed to a reducing environment (e.g. hydrogen, reformate) on one side and an oxidizing environment (e.g. air) on the other side at elevated temperatures. To understand the oxidation/corrosion behavior of metals and alloys under the dual exposures and assess their suitability, selected metals and alloys, including nickel, Fe-Cr and Ni-Cr base chromia forming alloys, alumina forming Fecralloy®, were investigated. It was found that the oxidation/corrosion behavior of metals and alloys in the presence of dual environment can be significantly different in terms of scale structure and/or chemistry from their exposure in a single oxidizing or reducing atmosphere. The anomalous oxidization/corrosion is attributed to the presence of hydrogen diffusion flux from the fuel side to the air side under the influence of a hydrogen gradient across the metallic substrates.

Yang, Z Gary; Xia, Gordon; Walker, Matthew S.; Wang, Chong M.; Stevenson, Jeffry W.; Singh, Prabhakar

2007-11-01T23:59:59.000Z

50

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

SciTech Connect

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.

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

2013-05-13T23:59:59.000Z

51

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

DOE Green Energy (OSTI)

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

Korosec, Michael A.

1983-11-01T23:59:59.000Z

52

1983 temperature gradient and heat flow drilling project for the State of Washington  

DOE Green Energy (OSTI)

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

Korosec, M.A.

1983-11-01T23:59:59.000Z

53

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

Science Conference Proceedings (OSTI)

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

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

2011-10-15T23:59:59.000Z

54

Retrieving Horizontal Temperature Gradients and Advections from Single-Station Wind Profiler Observations  

Science Conference Proceedings (OSTI)

Vertical wind shears measured by the Plattevilie, Colorado wind profiler were used in conjunction with the geostrophic thermal wind equation to retrieve the horizontal thermal gradients and associated advections for a case involving an upper-...

Paul J. Neiman; M. A. Shapiro

1989-06-01T23:59:59.000Z

55

Mercury Geochemical, Groundwater Geochemical, And Radiometric Geophysical  

Open Energy Info (EERE)

Geochemical, Groundwater Geochemical, And Radiometric Geophysical Geochemical, Groundwater Geochemical, And Radiometric Geophysical Signatures At Three Geothermal Prospects In Northern Nevada Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Mercury Geochemical, Groundwater Geochemical, And Radiometric Geophysical Signatures At Three Geothermal Prospects In Northern Nevada Details Activities (14) Areas (3) Regions (0) Abstract: Ground water sampling, desorbed mercury soil geochemical surveys and a radiometric geophysical survey was conducted in conjunction with geological mapping at three geothermal prospects in northern Nevada. Orientation sample lines from 610 m (2000 ft.) to 4575 m (15,000 ft.) in length were surveyed at right angles to known and suspected faults. Scintillometer readings (gamma radiation - total counts / second) were also

56

Trace Element Geochemical Zoning in the Roosevelt Hot Springs Thermal Area,  

Open Energy Info (EERE)

Page Page Edit with form History Facebook icon Twitter icon » Trace Element Geochemical Zoning in the Roosevelt Hot Springs Thermal Area, Utah Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Trace Element Geochemical Zoning in the Roosevelt Hot Springs Thermal Area, Utah Abstract Chemical interaction of thermal brines with reservoir rock in the Roosevelt Hot Springs thermal area has resulted in the development of distinctive trace element signatures. Geochemical analysis of soil sample, shallow temperature gradient drill hole cuttings and deep drill hole cutting provides a three dimensional perspective of trace element distributions within the system. Distributions of As, Hg and Li provide the clearest expression of hydrothermal activity. Comparison of these distribution

57

Temperature gradients in a portion of Michigan: a review of the usefulness of data from the AAPG geothermal survey of North America  

DOE Green Energy (OSTI)

Temperature gradient data derived from drill holes in an east-west zone through the center of the southern peninsula of Michigan are analyzed. The purpose of this work is to investigate possible problems in utilizing the American Association of Petroleum Geologists data base. Michigan was chosen because a review of that State's geothermal potential shows inconsistencies between gradients from shallow wells and nearby deeper wells and because the geology of the State is relativey simple. The structure and stratigraphy are discussed because an understanding of Michigan basin geology makes it easier to predict the influence of lithology on the basin's geothermal gradients. Explanations for elevated gradients are reviewed. (MHR)

Vaught, T.L.

1980-08-01T23:59:59.000Z

58

Representative Air Temperature of Thermally Heterogeneous Urban Areas Using the Measured Pressure Gradient  

Science Conference Proceedings (OSTI)

A method to measure an area-averaged ground air temperature based on the hydrostatic equation is shown. The method was devised to overcome the problem of finding the most representative surface air temperature over a wide region, a problem that ...

Hirofumi Sugawara; Ken-ichi Narita; Takehiko Mikami

2004-08-01T23:59:59.000Z

59

Definition: Thermal Gradient Holes | Open Energy Information  

Open Energy Info (EERE)

Gradient Holes Jump to: navigation, search Dictionary.png Thermal Gradient Holes "A hole logged by a temperature probe to determine the thermal gradient. Usually involves a hole...

60

The Doubled CO2 Climate: Impact of the Sea Surface Temperature Gradient  

Science Conference Proceedings (OSTI)

Even though five different general circulation models are all currently producing about a 4° ± 1°C warming for doubled CO2, there is still substantial model disagreement about the degree of high latitude amplification of the surface temperature ...

David Rind

1987-11-01T23:59:59.000Z

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


61

Investigation of electron temperature gradient driven micro-reconnecting modes in toroidal high-energy plasmas  

E-Print Network (OSTI)

Experiments carried out with magnetically confined, high temperature plasmas have revealed important effects that have yet to be justified by existing theory. In particular, there arises an anomalous particle inflow in the ...

Takasaki, Kevin T. (Keven Takao)

2007-01-01T23:59:59.000Z

62

Evaluations of Mesoscale Models' Simulations of Near-Surface Winds, Temperature Gradients, and Mixing Depths  

Science Conference Proceedings (OSTI)

Mesoscale meteorological models are being used to provide inputs of winds, vertical temperature and stability structure, mixing depths, and other parameters to atmospheric transport and dispersion models. An evaluation methodology is suggested ...

Steven R. Hanna; Ruixin Yang

2001-06-01T23:59:59.000Z

63

Radial Temperature Gradients of Overhead Conductors: Impact on Sag and Rating Calculations  

Science Conference Proceedings (OSTI)

It is critical for power companies to have a good understanding of the temperatures at which the bare phase conductors in their overhead transmission lines operate, particularly during system emergencies. Overhead lines are designed to have adequate clearance and normal aging for a maximum allowable conductor temperature (MACT). At or near the MACT, the electrical clearances to people, objects, buildings, and other lower-voltage conductors are at their minimum, and the design limit on loss of ...

2012-12-12T23:59:59.000Z

64

Solar Cycle Signal in Air Temperature in North America: Amplitude, Gradient, Phase and Distribution  

Science Conference Proceedings (OSTI)

The ll-year solar cycle temperature signal in records from North America is further elucidated by single- and two-channel (Morf et al., 1978) high-resolution signal processing. In agreement with earlier analysis (Currie, 1979) the signal Te, is ...

Robert G. Currie

1981-04-01T23:59:59.000Z

65

Development of an Experimental Data Base and Theories for Prediction of Thermodynamic Properties of Aqueous Electrolytes and Nonelectrolytes of Geochemical Significance at Supercritical Temperatures and Pressures.  

DOE Green Energy (OSTI)

The objective of this research was to combine new experimental measurements on heat capacities, volumes, and association constants of key compounds with theoretical equations of state and with first principles quantum mechanical calculations to generate predictions of thermodynamic data. The resulting thermodynamic data allow quantitative models of geochemical processes at high temperatures and pressures. Research funded by a DOE grant to Prof. Robert Wood at the University of Delaware involved the development of new theoretical equations of state for aqueous solutions of electrolytes and non-electrolytes, methods to estimate thermodynamic data not available from experiments, collection of data on model compounds through experiments and predictions of properties using ab initio quantum mechanics. During the last three and a half years, with support from our DOE grant, 16 papers have been accepted or published, and 3 more are in preparation. Results of this research have been reported in numerous invited and contributed presentations at national and international meetings. For this report, we will briefly comment on the highlights of the last 3 and a half years and give a complete list of papers published, accepted, or submitted during these years.

Wood, Robert H.

2005-10-11T23:59:59.000Z

66

Proceedings of the workshop on geochemical modeling  

SciTech Connect

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.

Not Available

1986-01-01T23:59:59.000Z

67

Alpine 1/Federal: Temperature gradients, geothermal potential, and geology. Final report, Part 2  

DOE Green Energy (OSTI)

The Alpine 1/Federal drilling project provided valuable new; information on the geology of the region. Except for drilling into Precambrian rocks, the objectives of the project were accomplished. sufficient temperature and heat-flow information were obtained to assess the near-term HDR geothermal potential of the eastern White Mountains region. Therefore, the primary mission of the project was successful. The HDR potential for near-term electrical power production is not economic. Potential for HDR direct-use space heating is marginal at best and should realistically be considered uneconomic. The Alpine 1/Federal hole should be deepened to Precambrian basement to provide definitive subsurface geological information for this region. Deeper drilling will determine Precambrian lithology and assess if older Paleozoic rock units are present. The hole may be deepened with a BQ drill string. Depth to Precambrian is likely to be between 800 and 2,000 feet below the current 4,505 feet total depth. The failure to reach Precambrian basement due to a previously unknown and unmapped major structural offset highlights the need for detailed surface geological mapping in this poorly understood region.

Witcher, J.C. [New Mexico State Univ., Las Cruces, NM (United States). Southwest Technology Development Inst.; Hahman, W.R. [Hahman (W. Richard), Las Cruces, NM (United States); Swanberg, C.A. [Swanberg (Chandler A.), Phoenix, AZ (United States)

1994-06-01T23:59:59.000Z

68

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

SciTech Connect

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.

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

69

History of Geochemical Modeling  

Science Conference Proceedings (OSTI)

Table 1   Sources of geochemical modeling software...www.telusplanet.net/public/geogams/index SOLVEQ/CHILLER Mark H. Reed Department of Geological

70

Geochemical Techniques | Open Energy Information  

Open Energy Info (EERE)

Geochemical Techniques Geochemical Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Geochemical Techniques Details Activities (0) Areas (0) Regions (0) NEPA(1) Exploration Technique Information Exploration Group: Geochemical Techniques Exploration Sub Group: None Parent Exploration Technique: Exploration Techniques Information Provided by Technique Lithology: Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png Geochemical Techniques: No definition has been provided for this term. Add a Definition Related Techniques Geochemical Techniques Geochemical Data Analysis Geothermometry Gas Geothermometry Isotope Geothermometry Liquid Geothermometry Cation Geothermometers Multicomponent Geothermometers Silica Geothermometers Thermal Ion Dispersion

71

The Determination of Surface-Layer Stability and Eddy Fluxes Using Wind Speed and Vertical Temperature Gradient Measurements  

Science Conference Proceedings (OSTI)

Analytical relations are developed that relate the Monin-Obukhov parameter to a modified bulk Richardson number expressed in terms of measured wind speed and vertical temperature difference. Measured Monin-Obukhov parameters and Richardson ...

I. T. Wang

1981-10-01T23:59:59.000Z

72

The Influence of Sea Surface Temperature Gradients on Stratiform Cloudiness along the Equatorial Front in the Pacific Ocean  

Science Conference Proceedings (OSTI)

Satellite observations of visible cloudiness and sea surface temperature (SST) are used to test the hypothesis that the configuration of cool low-level winds blowing across a sharp SST front in the equatorial eastern Pacific gives rise to ...

Clara Deser; Susan Wahl; John J. Bates

1993-06-01T23:59:59.000Z

73

Geochemical Data Analysis | Open Energy Information  

Open Energy Info (EERE)

Geochemical Data Analysis Geochemical Data Analysis Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Geochemical Data Analysis Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geochemical Techniques Exploration Sub Group: Geochemical Data Analysis Parent Exploration Technique: Geochemical Techniques Information Provided by Technique Lithology: Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png Geochemical Data Analysis: No definition has been provided for this term. Add a Definition References No exploration activities found. Print PDF Retrieved from "http://en.openei.org/w/index.php?title=Geochemical_Data_Analysis&oldid=594157" Categories: Geochemical Techniques Exploration Techniques

74

Geochemical Sampling of Thermal Waters in Nevada | Open Energy Information  

Open Energy Info (EERE)

Geochemical Sampling of Thermal Waters in Nevada Geochemical Sampling of Thermal Waters in Nevada Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Geochemical Sampling of Thermal Waters in Nevada Abstract There are 1000 thermal springs in Nevada for which a location is known, but for which there are no available temperature (or chemical) measurements. Although many of these sites are within known geothermal areas and are located near springs for which temperature and/or geochemical data are available for one of the springs, many of these sites are not so located and require evaluation before the geothermal potential of the area can be assessed. In order to begin filling in data gaps, water sampling commenced in 2002 when over 70 analyses were obtained from springs with previously

75

Influence of river level on temperature and hydraulic gradients in chum and fall Chinook salmon spawning areas downstream of Bonneville Dam, Columbia River  

SciTech Connect

Chum (Oncorhynchus keta) and fall Chinook (O. tshawytscha) salmon segregate spatially during spawning in the Ives Island side channel of the lower Columbia River downstream from Bonneville Dam. Previous research during one spawning season (2000) suggested that these species selected spawning habitats based on differences in hyporheic temperature and vertical hydraulic gradient (VHG) with the river. In this study, we confirmed the spatial segregation of spawning based on hyporheic characteristics over four years (2001–2004) and examined the effects of load-following operations (power generation to meet short-term electrical demand) at Bonneville Dam on hyporheic function and characteristics. We found that during the study period, hyporheic temperature and VHG in chum salmon spawning areas were highly variable during periods of load-following operation when river levels fluctuated. In contrast, hyporheic water temperature and VHG within chum spawning areas fluctuated less when river levels were not changing due to load-following operation. Variable temperature and VHG could affect chum and fall Chinook salmon spawning segregation and incubation success by altering the cues each species uses to select redd sites. Alterations in site selection would result in a breakdown in the spatial segregation of spawning between chum and fall Chinook salmon, which would expose earlier spawning fall Chinook eggs to a greater risk of dislodgement from later spawning chum salmon. Additional research will be required to fully assess the effects of load-following operations on the hyporheic environment and spawning and incubation success of chum and fall Chinook salmon downstream from Bonneville Dam.

Geist, David R.; Arntzen, Evan V.; Murray, Christopher J.; McGrath, Kathy; Bott, Yi-Ju; Hanrahan, Timothy P.

2008-02-01T23:59:59.000Z

76

A Geochemical Reconnaissance Of The Alid Volcaniccenter And Geothermal  

Open Energy Info (EERE)

Geochemical Reconnaissance Of The Alid Volcaniccenter And Geothermal Geochemical Reconnaissance Of The Alid Volcaniccenter And Geothermal System, Danakil Depression, Eritrea Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Geochemical Reconnaissance Of The Alid Volcaniccenter And Geothermal System, Danakil Depression, Eritrea Details Activities (0) Areas (0) Regions (0) Abstract: Geological and geochemical studies indicate that a high-temperature geothermalsystem underlies the Alid volcanic center in the northern Danakil depression of Eritrea Alid is avery late-Pleistocene structural dome formed by shallow intrusion of rhyolitic magma some of which vented as lavas and pyroclastic flows Fumaroles and boiling pools distributed widelyover an area of ~10 km2 on the northern half of Alid suggest that an activehydrothermal system underlies much of that part of

77

Low- to moderate-temperature geothermal resource assessment for Nevada: area specific studies, Pumpernickel Valley, Carlin and Moana. Final report June 1, 1981-July 31, 1982  

DOE Green Energy (OSTI)

Geological, geophysical and geochemical surveys were used in conjunction with temperature gradient hole drilling to assess the geothermal resources in Pumpernickel Valley and Carlin, Nevada. This program is based on a statewide assessment of geothermal resources that was completed in 1979. The exploration techniques are based on previous federally-funded assessment programs that were completed in six other areas in Nevada and include: literature search and compilation of existing data, geologic reconnaissance, chemical sampling of thermal and non-thermal fluids, interpretation of satellite imagery, interpretation of low-sun angle aerial photographs, two-meter depth temperature probe survey, gravity survey, seismic survey, soil-mercury survey, and temperature gradient drilling.

Trexler, D.T.; Flynn, T.; Koenig, B.A.; Bell, E.J.; Ghusn, G. Jr.

1982-01-01T23:59:59.000Z

78

Multielement geochemical exploration data for the Cove Fort-Sulphurdale Known Geothermal Resource Area, Beaver and Millard counties, Utah  

DOE Green Energy (OSTI)

Multielement geochemical exploration data have been acquired for the Cove Fort-Sulphurdale Known Geothermal Resource Area (KGRA). This was accomplished by analysis of both whole rock and +3.3 specific gravity concentrate samples from cuttings composites collected from shallow rotary drill holes. Areal distributions are reported for arsenic, mercury, lead and zinc. These are elements indicated by previous studies to be broadly zoned around thermal centers in geothermal systems and thus to be useful for selecting and prioritizing drilling targets. Results from this work suggest that reservoir temperature and/or reservoir to surface permeability, and thus possibly overall potential for a geothermal resource, increase northward beneath the approximately 18 square mile area containing shallow drill holes, possibly to beyond the northern limits of the area. The data provide a basis for development of three principal target models for the geothermal system but do not permit prioritization of these models. It is recommended that geochemical, geological, and temperature gradient surveys be expanded northward from the present survey area to more fully define the area which appears to have the best resource potential and to aid prioritization of the target models.

Bamford, R.W.; Christensen, O.D.

1979-09-01T23:59:59.000Z

79

Numerical Tests of the Weak Pressure Gradient Approximation  

Science Conference Proceedings (OSTI)

Cloud-resolving simulations of convection over a surface temperature hot spot are used to evaluate the weak pressure gradient (WPG) and weak temperature gradient (WTG) approximations. The premise of the relaxed form of WTG—that vertical velocity ...

David M. Romps

2012-09-01T23:59:59.000Z

80

Category:Geochemical Techniques | Open Energy Information  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Category Edit History Facebook icon Twitter icon » Category:Geochemical Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the Geochemical Techniques page? For detailed information on exploration techniques, click here. Category:Geochemical Techniques Add.png Add a new Geochemical Techniques Technique Subcategories This category has only the following subcategory. G [×] Geochemical Data Analysis‎ 3 pages Pages in category "Geochemical Techniques" This category contains only the following page. G Geochemical Data Analysis Retrieved from "http://en.openei.org/w/index.php?title=Category:Geochemical_Techniques&oldid=689823"

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


81

Merging High Resolution Geophysical and Geochemical Surveys to Reduce  

Open Energy Info (EERE)

Merging High Resolution Geophysical and Geochemical Surveys to Reduce Merging High Resolution Geophysical and Geochemical Surveys to Reduce Exploration Risk at Glass 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 Exploration Risk at Glass Buttes, Oregon Project Type / Topic 1 Recovery Act: Geothermal Technologies Program Project Type / Topic 2 Validation of Innovative Exploration Technologies Project Description This program will combine detailed gravity, high resolution aeromagnetic, and LIDAR data, all of which will be combined for structural modeling, with hyperspectral data, which will identify and map specific minerals and mineral assemblages that may point to upflow zones. The collection of these surveys and analyses of the merged data and model will be used to site deeper slim holes. Slim holes will be flow tested to determine whether or not Ormat can move forward with developing this resource. An innovative combination of geophysical and geochemical tools will significantly reduce risk in exploring this area, and the results will help to evaluate the value of these tools independently and in combination when exploring for blind resources where structure, permeability, and temperature are the most pressing questions. The slim holes will allow testing of models and validation of methods, and the surveys within the wellbores will be used to revise the models and site production wells if their drilling is warranted.

82

Weak Pressure Gradient Approximation and Its Analytical Solutions  

Science Conference Proceedings (OSTI)

A weak pressure gradient (WPG) approximation is introduced for parameterizing supradomain-scale (SDS) dynamics, and this method is compared to the relaxed form of the weak temperature gradient (WTG) approximation in the context of 3D, linearized, ...

David M. Romps

2012-09-01T23:59:59.000Z

83

The Moisture Mode in the Quasi-Equilibrium Tropical Circulation Model. Part I: Analysis Based on the Weak Temperature Gradient Approximation  

Science Conference Proceedings (OSTI)

The moisture mode in a simplified version of the quasi-equilibrium tropical circulation model (QTCM) of Neelin and Zeng is analyzed. Perturbation expansion based on the ratio of temperature tendency to adiabatic cooling simplifies the system and ...

Masahiro Sugiyama

2009-06-01T23:59:59.000Z

84

Lectures on geochemical interpretation of hydrothermal waters | Open Energy  

Open Energy Info (EERE)

form form View source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit with form History Facebook icon Twitter icon » Lectures on geochemical interpretation of hydrothermal waters Jump to: navigation, search OpenEI Reference LibraryAdd to library Report: Lectures on geochemical interpretation of hydrothermal waters Abstract The alkali carbonates, Na, K, and Li, are relatively soluble at all temperatures and generally precipitate only where there is extreme evapora- tion. In contrast, the alkaline earth carbonates. Ca. Ht, Sr, and Ba, are moderately to sparingly soluble and commonly precipitate in bydrothecmal systems. Calcite is by far the most abundant and important carbonate found

85

A geochemical expert system prototype using object-oriented knowledge representation and a production rule system  

Science Conference Proceedings (OSTI)

Keywords: MINEQL, artificial intelligence, expert systems, geochemical expert system, geochemical modeling, geochemistry

Forrest M. Hoffman; Vijay S. Tripathi

1993-01-01T23:59:59.000Z

86

Continuous spray forming of functionally gradient materials  

SciTech Connect

Researchers at Plasma Processes Inc. have produced a Functional Gradient Material (FGM) through advanced vacuum plasma spray processing for high heat flux applications. Outlined in this paper are the manufacturing methods used to develop a four component functional gradient material of copper, tungsten, boron, and boron nitride. The FGM was formed with continuous gradients and integral cooling channels eliminating bondlines and providing direct heat transfer from the high temperature exposed surface to a cooling medium. Metallurgical and x-ray diffraction analyses of the materials formed through innovative VPS (vacuum plasma spray) processing are also presented. Applications for this functional gradient structural material range from fusion reactor plasma facing components to missile nose cones to boilers.

McKechnie, T.N.; Richardson, E.H.

1995-12-01T23:59:59.000Z

87

Testing geochemical modeling codes using New Zealand hydrothermal systems  

DOE Green Energy (OSTI)

Hydrothermal systems in the Taupo Volcanic Zone, North Island, New Zealand are being used as field-based modeling exercises for the EQ3/6 geochemical modeling code package. Comparisons of the observed state and evolution of selected portions of the hydrothermal systems with predictions of fluid-solid equilibria made using geochemical modeling codes will: (1) ensure that we are providing adequately for all significant processes occurring in natural systems; (2) determine the adequacy of the mathematical descriptions of the processes; (3) check the adequacy and completeness of thermodynamic data as a function of temperature for solids, aqueous species and gases; and (4) determine the sensitivity of model results to the manner in which the problem is conceptualized by the user and then translated into constraints in the code input. Preliminary predictions of mineral assemblages in equilibrium with fluids sampled from wells in the Wairakei geothermal field suggest that affinity-temperature diagrams must be used in conjunction with EQ6 to minimize the effect of uncertainties in thermodynamic and kinetic data on code predictions. The kinetics of silica precipitation in EQ6 will be tested using field data from silica-lined drain channels carrying hot water away from the Wairakei borefield.

Bruton, C.J.; Glassley, W.E.; Bourcier, W.L.

1993-12-01T23:59:59.000Z

88

Geochemical exploration for uranium in the Red Desert, Wyoming  

SciTech Connect

Geochemical exploration techniques for uranium were performed at a known deposit, the ENQ uranium deposit, which is in arkosic sandstones of the Battle Spring Formation in the Red Desert of Wyoming. Regional gross-gamma aerial data did not indicate the most favorable terrain for follow-up surveys, but instead the radionuclide distribution mapped radioactive mudstones. The /sup 234/U//sup 238/U activity ratio and total uranium concentration in ground water were successful downflow indicators of the ENQ deposit. Helium concentration increased downflow in the ground water flowing from the deposit, while Cu, Pb, and Ba decreased. Radon emanometric techniques generally produced data that coincided with the equivalent uranium concentrations at shallow depth. Helium content in soil was interpreted to reflect local lithology and gaseous migration. Multielement geochemical analyses on soils were effective in delineating the general vicinity of the orebody. Factor analysis was used to recognize three lithologic subgroups. Leachable uranium in soils was the best indicator of subsurface mineralization for the entire subregional area. Equivalent uranium, as determined from the gamma-spectral borehole logs, revealed a consistent dispersion pattern within the host sand of the Battle Spring Formation, whereas gross gamma logs could not detect the subtle gradients in radioelement content. Halo models developed to explain the distribution of helium, radon, radioelements, and trace elements demonstrate uranium itself as the most mobile indicator. Radon and helium appear to reflect local generation from radium accumulations. Vertical leakage due to hydraulic flow against an impermeable barrier is interpreted to be the major secondary redistribution process responsible for the measureable surface signals.

Pacer, J.C.; Bramlett, L.; Moll, S.

1981-05-01T23:59:59.000Z

89

Geochemical Enhancement Of Enhanced Geothermal System Reservoirs: An Integrated Field And Geochemical Approach  

DOE Green Energy (OSTI)

The geochemical effects of injecting fluids into geothermal reservoirs are poorly understood and may be significantly underestimated. Decreased performance of injection wells has been observed in several geothermal fields after only a few years of service, but the reasons for these declines has not been established. This study had three primary objectives: 1) determine the cause(s) of the loss of injectivity; 2) utilize these observations to constrain numerical models of water-rock interactions; and 3) develop injection strategies for mitigating and reversing the potential effects of these interactions. In this study rock samples from original and redrilled injection wells at Coso and the Salton Sea geothermal fields, CA, were used to characterize the mineral and geochemical changes that occurred as a result of injection. The study documented the presence of mineral scales and at both fields in the reservoir rocks adjacent to the injection wells. At the Salton Sea, the scales consist of alternating layers of fluorite and barite, accompanied by minor anhydrite, amorphous silica and copper arsenic sulfides. Amorphous silica and traces of calcite were deposited at Coso. The formation of silica scale at Coso provides an example of the effects of untreated (unacidified) injectate on the reservoir rocks. Scanning electron microscopy and X-ray diffractometry were used to characterize the scale deposits. The silica scale in the reservoir rocks at Coso was initially deposited as spheres of opal-A 1-2 micrometers in diameter. As the deposits matured, the spheres coalesced to form larger spheres up to 10 micrometer in diameter. Further maturation and infilling of the spaces between spheres resulted in the formation of plates and sheets that substantially reduce the original porosity and permeability of the fractures. Peripheral to the silica deposits, fluid inclusions with high water/gas ratios provide a subtle record of interactions between the injectate and reservoir rocks. In contrast, fluid inclusions trapped prior to injection are relatively gas rich. These results suggest that the rocks undergo extensive microfracturing during injection and that the composition of the fluid inclusions will be biased toward the youngest event. Interactions between the reservoir rocks and injectate were modeled using the non-isothermal reactive geochemical transport code TOUGHREACT. Changes in fluid pH, fracture porosity, fracture permeability, fluid temperature, and mineral abundances were monitored. The simulations predict that amorphous silica will precipitate primarily within a few meters of the injection well and that mineral deposition will lead to rapid declines in fracture porosity and permeability, consistent with field observations. In support of Enhanced Geothermal System development, petrologic studies of Coso well 46A-19RD were conducted to determine the regions that are most likely to fail when stimulated. These studies indicate that the most intensely brecciated and altered rocks in the zone targeted for stimulation (below 10,000 ft (3048 m)) occur between 11,200 and 11,350 ft (3414 and 3459 m). This zone is interpreted as a shear zone that initially juxtaposed quartz diorite against granodiorite. Strong pervasive alteration and veining within the brecciated quartz diorite and granodiorite suggest this shear zone was permeable in the past. This zone of weakness was subsequently exploited by a granophyre dike whose top occurs at 11,350 ft (3459 m). The dike is unaltered. We anticipate, based on analysis of the well samples that failure during stimulation will most likely occur on this shear zone.

Joseph N. Moore

2007-12-31T23:59:59.000Z

90

NUREG/CR-6870 Consideration of Geochemical  

E-Print Network (OSTI)

mining and milling of uranium ore. Nonetheless, the use of leaching fluids to mine uranium contaminatesNUREG/CR-6870 Consideration of Geochemical Issues in Groundwater Restoration at Uranium In in Groundwater Restoration at Uranium In-Situ Leach Mining Facilities Manuscript Completed: December 2006 Date

91

Airborne-temperature-survey maps of heat-flow anomalies for exploration geology  

DOE Green Energy (OSTI)

Precise airborne temperature surveys depicted small predawn surface temperature differences related to heat flow anomalies at the Long Valley, California, KGRA. Zones with conductive heat flow differences of 45 +- 16 ..mu..cal/cm/sup 2/(s) has predawn surface temperature differences of 1.4 +- 0.3/sup 0/C. The warmer zones had hot water circulating in a shallow (less than 60-m-deep) aquifer. Hot water is a useful geochemical indicator of geothermal and mineral resource potential. The precise airborne temperature survey method recorded redundant infrared scanner signals at two wavelengths (10 to 12 ..mu..m and 4.5 to 5.5 ..mu..m) and two elevations (0.3 km and 1.2 km). Ground thermistor probes recorded air and soil temperatures during the survey overflights. Radiometric temperatures were corrected for air-path and reflected-sky-radiation effects. Corrected temperatures were displayed in image form with color-coded maps which depicted 0.24/sup 0/C temperature differences. After accounting for surficial features on the corrected predawn thermal imagery, there remained several anomalous zones. These zones had high temperature gradients at depths from 6 to 30 m, compared to the temperature gradients in nearby areas.

Del Grande, N.K.

1982-11-10T23:59:59.000Z

92

Geochemical engineering problem identification and program description. Final report  

SciTech Connect

The Geochemical Engineering Program has as its goal the improvement of geochemical fluid management techniques. This document presents the strategy and status of the Geochemical Engineering Program. The magnitude and scope of geochemical-related problems constraining geothermal industry productivity are described. The goals and objectives of the DGE Geochemical Engineering Program are defined. The rationale and strategy of the program are described. The structure, priorities, funding, and management of specific elements within the program are delineated, and the status of the overall program is presented.

Crane, C.H.; Kenkeremath, D.C.

1981-05-01T23:59:59.000Z

93

Experimental Geochemical Studies Relevant to Carbon Sequestration  

NLE Websites -- All DOE Office Websites (Extended Search)

Geochemical Studies Relevant to Geochemical Studies Relevant to Carbon Sequestration James G. Blencoe (blencoejg@ornl.gov; 865-574-7041) David R. Cole (coledr@ornl.gov; 865-574-5473) Juske Horita (horitaj@ornl.gov; 865-576-2750) Geochemistry Group Chemical and Analytical Sciences Division Oak Ridge National Laboratory P.O. Box 2008, Building 4500-S Oak Ridge, TN 37831-6110 Gerilynn R. Moline (molinegr@ornl.gov; 865-576-5134) Environmental Sciences Division Oak Ridge National Laboratory P.O. Box 2008, Building 1505 Oak Ridge, TN 37831-6038 Introduction Evidence is mounting that rising levels of atmospheric CO 2 will have profound effects on future global climates (1-2) . Consequently, many experts agree that technologies are needed to slow, and ultimately stop, further buildup (3-5) . One of the strategies proposed to achieve this aim

94

Thermal Gradient Holes At Coso Geothermal Area (1976) | Open Energy  

Open Energy Info (EERE)

Thermal Gradient Holes At Coso Geothermal Area (1976) Thermal Gradient Holes At Coso Geothermal Area (1976) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Coso Geothermal Area (1976) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Thermal Gradient Holes Activity Date 1976 Usefulness useful DOE-funding Unknown Notes Temperatures have been obtained to depths up to 133 m in 22 boreholes with measurements being made at least four times in each borehole. Geothermal gradients ranged from 240C/km to 450 0C/km. References Combs, J. (1 December 1976) Heat flow determinations and implied thermal regime of the Coso geothermal area, California Retrieved from "http://en.openei.org/w/index.php?title=Thermal_Gradient_Holes_At_Coso_Geothermal_Area_(1976)&oldid=511217"

95

On Computing the Horizontal Pressure Gradient Force in Sigma Coordinates  

Science Conference Proceedings (OSTI)

Corby et al. present a finite-difference expression for the horizontal pressure gradient force in sigma coordinates that, in a barotropic atmosphere where the temperature varies linearly with logarithm of pressure, has the same net truncation ...

Maurice Danard; Qing Zhang; John Kozlowski

1993-11-01T23:59:59.000Z

96

Nickel gradient electrode  

SciTech Connect

This invention relates generally to rechargeable batteries, and, in particular, relates to batteries that use nickel electrodes. It provides an improved nickel electrode with a selected gradient of additive materials. The concentration of additives in the impregnating solution are controlled during impregnation such that an additive gradient is generated. In the situation where the highest ionic conductivity is needed at the current collector boundary with the active material, the electrochemical impregnating solution is initially high in additive, and at the end of impregnation has been adjusted to significantly lower additive concentration. For chemical impregnation, the electrodes are similarly dipped in solutions that are initially high in additive. This invention is suitable for conventional additives such as cobalt, cadmium, barium, manganese, and zinc. It is therefore one objective of the invention to provide an improved nickel electrode of a battery cell with an additive in the active material to increase the life of the battery cell. Another objective is to provide for an improved nickel electrode having a greater concentration of additive near the current collector of nickel.

Zimmerman, A.H.

1988-03-31T23:59:59.000Z

97

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

Open Energy Info (EERE)

2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Lake City Hot Springs Area (Warpinski, Et Al., 2004) Exploration Activity Details Location Lake City Hot Springs Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness not indicated DOE-funding Unknown Notes The Lake City site, which is located in far northeastern California, consists of a previously identified geothermal site that has been explored with both geophysics and drilling (Hedel, 1981), but has not been characterized adequately to allow accurate siting or drilling of production wells. Some deep wells, several seismic lines, limited gravity surveys, and geochemical and geological studies have suggested that the geothermal

98

Reservoir simulation and geochemical study of Cerro Prieto I wells  

DOE Green Energy (OSTI)

Combined reservoir simulation and geochemical data analysis are used to investigate the effects of recharge and other reservoir processes occurring in the western part of the Cerro Prieto, Mexico, geothermal field (i.e., Cerro Prieto I area). Enthalpy-based temperatures and bottomhole temperatures are calculated based on simplified models of the system, considering different reservoir boundary conditions and zones of contrasting initial temperatures and reservoir properties. By matching the computed trends with geothermometer-based temperature and enthalpy histories of producing wells, the main processes active in the western area of Cerro Prieto are identified. This part of the geothermal system is strongly influenced by nearby groundwater aquifers; cooler waters readily recharge the reservoirs. In response to exploitation, the natural influx of cold water into the shallower alpha reservoir is mainly from the west and down Fault L, while the recharge to the deeper beta reservoir in this part of the field, seems to be only lateral, from the west and possibly south. 11 refs., 12 figs.

Lippmann, M.J. (Lawrence Berkeley Lab., CA (USA)); Truesdell, A.H. (Geological Survey, Menlo Park, CA (USA))

1990-03-01T23:59:59.000Z

99

Category:Geochemical Data Analysis | Open Energy Information  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Category Edit History Facebook icon Twitter icon » Category:Geochemical Data Analysis Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the Geochemical Data Analysis page? For detailed information on exploration techniques, click here. Category:Geochemical Data Analysis Add.png Add a new Geochemical Data Analysis Technique Pages in category "Geochemical Data Analysis" The following 3 pages are in this category, out of 3 total. G Geothermometry T Thermal Ion Dispersion Thermochronometry Retrieved from "http://en.openei.org/w/index.php?title=Category:Geochemical_Data_Analysis&oldid=689825"

100

Generalized Stochastic Gradient Learning  

E-Print Network (OSTI)

#1;#2;#3;#2;#4;#5;#6;#7;#8;#2; #11;#12; #14;#15;#5;#16;#12;#7;#14; #1;#4;#5; #7;#2;#3;#12; #17;#2;#5;#4;#3;#7;#3;#18; George W. Evans, Seppo Honkapohja and Noah Willams #19;#14;#12; #20;#2;#4; #21;#22;#22;#23; #24;#25;#26;#27; #22;#23;#28;#23; #1... ;#2;#3;#4;#3;#2;#4;#5;#6;#4;#7;#8;#2;#3;#6; #4; #11;#3;#12;#2;#8;#3;#4; #6;#14;#15;#11;#16;#16;#11;#2;#17; Generalized Stochastic Gradient Learning? George W. Evans University of Oregon Seppo Honkapohja University of Cambridge Noah Williams Princeton...

Evans, George W; Honkapohja, Seppo; Williams, Noah

2006-03-14T23:59:59.000Z

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


101

Temporal Geochemical Variations In Volatile Emissions From Mount...  

Open Energy Info (EERE)

Temporal Geochemical Variations In Volatile Emissions From Mount St Helens, Usa, 1980-1994 Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Temporal...

102

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

Open Energy Info (EERE)

Element Geochemical Zoning in the Roosevelt Hot Springs Thermal Area, Utah Abstract Chemical interaction of thermal brines with reservoir rock in the Roosevelt Hot Springs...

103

Gradient Resources | Open Energy Information  

Open Energy Info (EERE)

Resources Resources Jump to: navigation, search Logo: Gradient Resources Name Gradient Resources Address 9670 Gateway Drive, Suite 200 Place Reno, Nevada Zip 89521 Sector Geothermal energy Year founded 1991 Company Type For Profit Phone number (775) 284-8842 Website http://www.gradient.com/ Region Rockies Area References Gradient Resources Website[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! Gradient Resources is a company based in Reno, Nevada. Gradient Resources is engaged in the exploration and development of geothermal resources as well as the construction, ownership and operation of geothermal power plants. The Company is headquartered in Reno, Nevada with a regional office, drilling operations center, and well-cementing

104

DNA-based methods of geochemical prospecting  

Science Conference Proceedings (OSTI)

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.

Ashby, Matthew (Mill Valley, CA)

2011-12-06T23:59:59.000Z

105

Gradient zone boundary control in salt gradient solar ponds  

SciTech Connect

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

Hull, John R. (Downers Grove, IL)

1984-01-01T23:59:59.000Z

106

Field-based tests of geochemical modeling codes using New Zealand hydrothermal systems  

DOE Green Energy (OSTI)

Hydrothermal systems in the Taupo Volcanic Zone, North Island, New Zealand are being used as field-based modeling exercises for the EQ3/6 geochemical modeling code package. Comparisons of the observed state and evolution of the hydrothermal systems with predictions of fluid-solid equilibria made using geochemical modeling codes will determine how the codes can be used to predict the chemical and mineralogical response of the environment to nuclear waste emplacement. Field-based exercises allow us to test the models on time scales unattainable in the laboratory. Preliminary predictions of mineral assemblages in equilibrium with fluids sampled from wells in the Wairakei and Kawerau geothermal field suggest that affinity-temperature diagrams must be used in conjunction with EQ6 to minimize the effect of uncertainties in thermodynamic and kinetic data on code predictions.

Bruton, C.J.; Glassley, W.E.; Bourcier, W.L.

1994-06-01T23:59:59.000Z

107

GEOCHEMICAL CONTROLS ON NUCLEAR MAGNETIC RESONANCE MEASUREMENTS  

Science Conference Proceedings (OSTI)

Proton nuclear magnetic resonance (NMR) is used in the Earth Sciences as a means of obtaining information about the molecular-scale environment of fluids in porous geological materials. Laboratory experiments were conducted to advance our fundamental understanding of the link between the NMR response and the geochemical properties of geological materials. In the first part of this research project, we studied the impact of both the surface-area-to-volume ratio (S/V) of the pore space and the surface relaxivity on the NMR response of fluids in sand-clay mixtures. This study highlighted the way in which these two parameters control our ability to use NMR measurements to detect and quantify fluid saturation in multiphase saturated systems. The second part of the project was designed to explore the way in which the mineralogic form of iron, as opposed to simply the concentration of iron, affects the surface relaxation rate and, more generally, the NMR response of porous materials. We found that the magnitude of the surface relaxation rate was different for the various iron-oxide minerals because of changes in both the surface-area-to-volume ratio of the pore space, and the surface relaxivity. Of particular significance from this study was the finding of an anomalously large surface relaxivity of magnetite compared to that of the other iron minerals. Differences in the NMR response of iron minerals were seen in column experiments during the reaction of ferrihydrite-coated quartz sand with aqueous Fe(II) solutions to form goethite, lepidocrocite and magnetite; indicating the potential use of NMR as a means of monitoring geochemical reactions. The final part of the research project investigated the impact of heterogeneity, at the pore-scale, on the NMR response. This work highlighted the way in which the geochemistry, by controlling the surface relaxivity, has a significant impact on the link between NMR data and the microgeometry of the pore space.

Rosemary Knight

2008-08-25T23:59:59.000Z

108

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

Science Conference Proceedings (OSTI)

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.

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

2010-09-28T23:59:59.000Z

109

Incremental criticality and yield gradients  

Science Conference Proceedings (OSTI)

Criticality and yield gradients are two crucial diagnostic metrics obtained from Statistical Static Timing Analysis (SSTA). They provide valuable information to guide timing optimization and timing-driven physical synthesis. Existing work in the literature, ...

Jinjun Xiong; Vladimir Zolotov; Chandu Visweswariah

2008-03-01T23:59:59.000Z

110

First Look at Gradient Crystals  

NLE Websites -- All DOE Office Websites (Extended Search)

Beamline 7.3.3. When current is applied to the block copolymer, as in charging a battery, a new structure emerges. balsara-gradient cystals (a) "Sundial" x-ray scattering...

111

Quantification of Texture and Microstructure Gradients in ...  

Science Conference Proceedings (OSTI)

Strain Gradient and Degradation in Magnetic Properties: Focus Transformer Steel · Strain Gradient Crystal Plasticity Finite Element Modeling of Alpha-Iron.

112

Analysis and Geochemical Modeling of Vanadium Contamination in Groundwater New Rifle Processing Site, Colorado  

Energy.gov (U.S. Department of Energy (DOE))

Analysis and Geochemical Modeling of Vanadium Contamination in Groundwater New Rifle Processing Site, Colorado

113

Factors Controlling The Geochemical Evolution Of Fumarolic Encrustations,  

Open Energy Info (EERE)

Controlling The Geochemical Evolution Of Fumarolic Encrustations, Controlling The Geochemical Evolution Of Fumarolic Encrustations, Valley Of Ten Thousand Smokes, Alaska Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Factors Controlling The Geochemical Evolution Of Fumarolic Encrustations, Valley Of Ten Thousand Smokes, Alaska Details Activities (3) Areas (1) Regions (0) Abstract: Factor and canonical correlation analysis of geochemical data from eight fossil fumaroles suggest that six major factors controlled the formation and evolution of fumarolic encrustations on the 1912 ash-flow sheet in the Valley of Ten Thousand Smokes (VTTS). The six-factor solution model explains a large proportion (low of 74% for Ni to high of 99% for Si) of the individual element data variance. Although the primary fumarolic

114

Molecular geomicrobiology: genes and geochemical cycling Jennifer Macalady 1  

E-Print Network (OSTI)

Frontiers Molecular geomicrobiology: genes and geochemical cycling Jennifer Macalady 1 , Jillian F occurs. Yet, the field of molecular geomicrobiology remains in its infancy. In the foreseeable future, merging of modern biogeochemistry with molecularly resolved ecological studies will inspire

Macalady, Jenn

115

Geothermal gradient drilling, north-central Cascades of Oregon, 1979  

DOE Green Energy (OSTI)

A geothermal gradient drilling program was conducted on the western flank of the north-central Cascade Mountains in Oregon. Six wells were drilled during this program, although in effect seven were drilled, as two wells were drilled at site 3, the second well, however, actually going to a lesser depth than the first. Three of the wells (3, 4, and 5) were drilled in areas which topographically are subject to strong throughflows of ground water. None of these wells reached the regional water table, and all showed essentially isothermal geothermal gradients. The single well which was started essentially at the water table (well 6) shows a linear temperature rise with depth essentially from the top of the well bore. Well No. 2 shows an isothermal gradient down to the level of the regional water table and then shows a linear gradient of about 70/sup 0/C/km from the regional water table to total depth.

Youngquist, W.

1980-01-01T23:59:59.000Z

116

Pumpernickel Valley Geothermal Project Thermal Gradient Wells  

DOE Green Energy (OSTI)

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

Z. Adam Szybinski

2006-01-01T23:59:59.000Z

117

Scaffold Gradients: Finding the Right Environment for ...  

Science Conference Proceedings (OSTI)

Scaffold Gradients: Finding the Right Environment for Developing Cells. For Immediate Release: May 25, 2010. ...

2013-05-14T23:59:59.000Z

118

Gradient Combinatorial Libraries via Modulated Light ...  

Science Conference Proceedings (OSTI)

... Libraries via Modulated Light Exposure. Bookmark and Share Gradient Combinatorial Libraries via Modulated Light Exposure. ...

119

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

DOE Data Explorer (OSTI)

•\tFavorability and Evidence Data û 7 WinRAR ZIP files and links to detailed metadata. Includes data from regression models, gravity and temperature gradients, dilational strain data, and weighted earthquake epicenter data.

120

Thermal Gradient Holes At Chocolate Mountains Area (Alm, Et Al., 2010) |  

Open Energy Info (EERE)

Chocolate Mountains Area (Alm, Et Al., 2010) Chocolate Mountains Area (Alm, Et Al., 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Chocolate Mountains Area (Alm, Et Al., 2010) Exploration Activity Details Location Chocolate Mountains Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness useful DOE-funding Unknown Notes "Shallow temperature gradient drilling began at the CMAGR in January of 2010. 13 temperature gradient holes were completed to a depth of 500' below ground surface. Sites were selected based on the compilation of previous exploration and resulting data is being integrated into the most recent geologic model. This model will form the basis for the selection of a deeper (2000'-4000') temperature gradient drilling campaign at the CMAGR in

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


121

Spatial And Temporal Geochemical Trends In The Hydrothermal System Of  

Open Energy Info (EERE)

Spatial And Temporal Geochemical Trends In The Hydrothermal System Of Spatial And Temporal Geochemical Trends In The Hydrothermal System Of Yellowstone National Park- Inferences From River Solute Fluxes Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Spatial And Temporal Geochemical Trends In The Hydrothermal System Of Yellowstone National Park- Inferences From River Solute Fluxes Details Activities (2) Areas (1) Regions (0) Abstract: We present and analyze a chemical dataset that includes the concentrations and fluxes of HCO3-, SO42-, Cl-, and F- in the major rivers draining Yellowstone National Park (YNP) for the 2002-2004 water years (1 October 2001 - 30 September 2004). The total (molar) flux in all rivers decreases in the following order, HCO3- > Cl- > SO42- > F-, but each river is characterized by a distinct chemical composition, implying large-scale

122

Hg Anomalies In Soils- A Geochemical Exploration Method For Geothermal  

Open Energy Info (EERE)

Hg Anomalies In Soils- A Geochemical Exploration Method For Geothermal Hg Anomalies In Soils- A Geochemical Exploration Method For Geothermal Areas Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Hg Anomalies In Soils- A Geochemical Exploration Method For Geothermal Areas Details Activities (5) Areas (5) Regions (0) Abstract: Hg contents of soils in geothermal areas in the western U.S. were measured and a three-fold distribution was observed: peak, aureole and background. Peak values (up to several 100 ppm Hg) occur in fumaroles of vapour-dominated systems, around hot springs, and in zones overlying steeply dipping, hot-water aquifers. Aureoic values (up to several 100 ppb Hg) are found in zones surrounding the peak areas and delineate areas with shallow geothermal convection. Background values vary between 7 and 40 ppb

123

A Geochemical Model Of The Platanares Geothermal System, Honduras | Open  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » A Geochemical Model Of The Platanares Geothermal System, Honduras Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Geochemical Model Of The Platanares Geothermal System, Honduras Details Activities (0) Areas (0) Regions (0) Abstract: Results of exploration drilling combined with results of geologic, geophysical, and hydrogeochemical investigations have been used to construct a geochemical model of the Platanares geothermal system, Honduras. Three coreholes were drilled, two of which produced fluids from fractured Miocene andesite and altered Cretaceous to Eocene conglomerate at

124

Temporal Geochemical Variations In Volatile Emissions From Mount St Helens,  

Open Energy Info (EERE)

Temporal Geochemical Variations In Volatile Emissions From Mount St Helens, Temporal Geochemical Variations In Volatile Emissions From Mount St Helens, Usa, 1980-1994 Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Temporal Geochemical Variations In Volatile Emissions From Mount St Helens, Usa, 1980-1994 Details Activities (2) Areas (1) Regions (0) Abstract: Fumarole discharges (95-560°C) collected from the dacite dome inside Mount St. Helens crater show temporal changes in their isotopic and chemical compositions. A ΔD vs. Δ18O plot shows that condensed waters from the gases are mixtures of meteoric and magmatic components, but that the apparent magmatic end-member in 1994 was depleted by about 7‰ in ΔD relative to the apparent end-member in 1980. Based on ΔD modeling, approximately 63% of shallow, post-1980 magma has yet to degas.

125

Alteration And Geochemical Zoning In Bodie Bluff, Bodie Mining District,  

Open Energy Info (EERE)

Alteration And Geochemical Zoning In Bodie Bluff, Bodie Mining District, Alteration And Geochemical Zoning In Bodie Bluff, Bodie Mining District, Eastern California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Alteration And Geochemical Zoning In Bodie Bluff, Bodie Mining District, Eastern California Details Activities (0) Areas (0) Regions (0) Abstract: Banded, epithermal quartz-adularia veins have produced about 1.5 million ounces of gold and 7 million ounces of silver from the Bodie mining district, eastern California. The veins cut dacitic lava flows, pyroclastic rocks and intrusions. Sinter boulders occur in a graben structure at the top of Bodie Bluff and fragments of sinter and mineralized quartz veins occur in hydrothermal breccias nearby. Explosive venting evidently was part of the evolution of the ore-forming geothermal systems which, at one time,

126

A Reconnaissance Geochemical Study Of La Primavera Geothermal Area,  

Open Energy Info (EERE)

Reconnaissance Geochemical Study Of La Primavera Geothermal Area, Reconnaissance Geochemical Study Of La Primavera Geothermal Area, Jalisco, Mexico Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Reconnaissance Geochemical Study Of La Primavera Geothermal Area, Jalisco, Mexico Details Activities (0) Areas (0) Regions (0) Abstract: The Sierra La Primavera, a late Pleistocene rhyolitic caldera complex in Jalisco, Mexico, contains fumaroles and large-discharge 65°C hot springs that are associated with faults related to caldera collapse and to later magma insurgence. The nearly-neutral, sodium bicarbonate, hot springs occur at low elevations at the margins of the complex, whereas the water-rich fumaroles are high and central. The Comision Federal de Electricidad de Mexico (CFE) has recently drilled two deep holes at the

127

Revisiting an Old Concept: The Gradient Wind  

Science Conference Proceedings (OSTI)

The gradient wind is defined as a horizontal wind having the same direction as the geostrophic wind but with a magnitude consistent with a balance of three forces: the pressure gradient force, the Coriolis force, and the centrifugal force arising ...

Keith F. Brill

128

Geochemical assessment of gaseous hydrocarbons: mixing of bacterial and thermogenic methane in the deep subsurface petroleum system, Gulf of Mexico continental slope  

E-Print Network (OSTI)

Mixtures of bacterial and thermogenic methane are found both at vents at the seafloor and in reservoirs in the deep subsurface of the Gulf of Mexico continental slope. The C1-C5 gas that most recently charged reservoirs of Jolliet (GC 184), Genesis (GC 160/161) and Petronius (VK 786) fields is estimated to include 17%-28%, 31%-51%, 31%-49% bacterial methane, respectively. Geochemical assessment of the reservoir gas in the fields show that the gas may be the product of thermal cracking of Upper Jurassic crude oil before final migration to the reservoirs. The gas from three different fields is of similar thermal maturity levels. In contrast to oil in reservoirs in the fields, which shows biodegradation effects, the C1-C5 reservoir gas is unaltered by biodegradation. Late gas migration may have occurred at or near present burial depth and flushed the reservoir system of previously biodegraded hydrocarbon gas to include any previous bacterial methane. Molecular and isotopic properties of reservoir gas and oil suggest that bacterial methane mixed with thermogenic hydrocarbon gas before entering the reservoirs. Thus the source of the bacterial methane is logically deeper than the present depth (>~4 km) and temperatures of the reservoirs. High sedimentation rate and low geothermal gradient may offer conditions favorable for generation and preservation of bacterial methane in deep subsurface petroleum system of the Gulf slope. Bacterial methane dispersed across the large drainage areas of the deep subsurface petroleum system may have been swept by migrating fluids at >4 km, and then charged both vents (GC 185, GC 233 and GC 286) at the seafloor and reservoirs in the deep subsurface. The volume of bacterial methane from geologically significant depth in rapidly subsiding basins may be underestimated.

Ozgul, Ercin

2002-08-01T23:59:59.000Z

129

Distribution and Geochemical Evolution of Fluoride in Groundwater of Taiyuan Basin, China  

Science Conference Proceedings (OSTI)

Hydrogeochemistry data were utilized to understand origin, distribution, and geochemical evolution of the high-fluoride groundwater in Taiyuan basin, China. In the study area, the spatial distribution of the high fluoride groundwater are strictly controlled ... Keywords: fluoride, geochemical mechanism

Xiangquan Li; Xinwei Hou; Zhichao Zhou; Lingxia Liu

2009-10-01T23:59:59.000Z

130

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

E-Print Network (OSTI)

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 ...

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

2003-01-01T23:59:59.000Z

131

Near Boundary Gradient Zone: An Overview  

Science Conference Proceedings (OSTI)

Analyzing Upper Tails of Grain Size Distributions Using Extreme Value ... Strain Gradient and Degradation in Magnetic Properties: Focus Transformer Steel.

132

Locally exact modifications of discrete gradient schemes  

E-Print Network (OSTI)

Locally exact integrators preserve linearization of the original system at every point. We construct energy-preserving locally exact discrete gradient schemes for arbitrary multidimensional canonical Hamiltonian systems by modifying classical discrete gradient schemes. Modifications of this kind are found for any discrete gradient.

Cie?li?ski, Jan L

2013-01-01T23:59:59.000Z

133

Synthesis of organic geochemical data from the Eastern Gas Shales  

Science Conference Proceedings (OSTI)

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.

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

1982-01-01T23:59:59.000Z

134

Long-term behavior of the Atlantic Interhemispheric SST Gradient in the CMIP5 Historical Simulations  

Science Conference Proceedings (OSTI)

Multidecadal and longer changes to the Atlantic Interhemispheric sea surface temperature gradient (AITG) in the Coupled Model Intercomparison Project phase 5 (CMIP5) historical simulations are investigated. Observations show a secular trend to ...

John C. H. Chiang; C.-Y. Chang; M. F. Wehner

135

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

Open Energy Info (EERE)

temperature gradient holes (86-15 O on Pad 1 and 17-16 O on Pad 3); conducted seismic, gravity and magnetotelluric surveys; and drilled deep exploration wells at Pads 6 and 8 and...

136

Double-Diffusive Intrusions in a Stable Salinity Gradient “Heated from Below”  

Science Conference Proceedings (OSTI)

Two-dimensional direct numerical simulations (DNS) are used to investigate the growth and nonlinear equilibration of spatially periodic double-diffusive intrusion for negative vertical temperature Tz < 0 and salinity Sz < 0 gradients, which are ...

Julian Simeonov; Melvin E. Stern

2008-10-01T23:59:59.000Z

137

The Eady Problem for a Basic State with Zero PV Gradient but ? ? 0  

Science Conference Proceedings (OSTI)

The classic Eady problem is modified to include ? ? 0, but with the basic distributions of temperature and zonal flow adjusted to preserve zero meridional gradients of basic-state potential vorticity in the fluid interior. Much of the ...

Richard S. Lindzen

1994-11-01T23:59:59.000Z

138

Double-Diffusive Intrusions in a Stable Salinity Gradient “Heated from Below”  

Science Conference Proceedings (OSTI)

Two-dimensional direct numerical simulations (DNS) are used to investigate the growth and nonlinear equilibration of spatially periodic double-diffusive intrusion for negative vertical temperature Tz gradients, which are ...

Julian Simeonov; Melvin E. Stern

2008-10-01T23:59:59.000Z

139

Validation of the WATEQ4 geochemical model for uranium  

SciTech Connect

As part of the Geochemical Modeling and Nuclide/Rock/Groundwater Interactions Studies Program, a study was conducted to partially validate the WATEQ4 aqueous speciation-solubility geochemical model for uranium. The solubility controls determined with the WATEQ4 geochemical model were in excellent agreement with those laboratory studies in which the solids schoepite (UO/sub 2/(OH)/sub 2/ . H/sub 2/O), UO/sub 2/(OH)/sub 2/, and rutherfordine ((UO/sub 2/CO/sub 3/) were identified as actual solubility controls for uranium. The results of modeling solution analyses from laboratory studies of uranyl phosphate solids, however, identified possible errors in the characterization of solids in the original solubility experiments. As part of this study, significant deficiencies in the WATEQ4 thermodynamic data base for uranium solutes and solids were corrected. Revisions included recalculation of selected uranium reactions. Additionally, thermodynamic data for the hydroxyl complexes of U(VI), including anionic (VI) species, were evaluated (to the extent permitted by the available data). Vanadium reactions were also added to the thermodynamic data base because uranium-vanadium solids can exist in natural ground-water systems. This study is only a partial validation of the WATEQ4 geochemical model because the available laboratory solubility studies do not cover the range of solid phases, alkaline pH values, and concentrations of inorganic complexing ligands needed to evaluate the potential solubility of uranium in ground waters associated with various proposed nuclear waste repositories. Further validation of this or other geochemical models for uranium will require careful determinations of uraninite solubility over the pH range of 7 to 10 under highly reducing conditions and of uranyl hydroxide and phosphate solubilities over the pH range of 7 to 10 under oxygenated conditions.

Krupka, K.M.; Jenne, E.A.; Deutsch, W.J.

1983-09-01T23:59:59.000Z

140

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

SciTech Connect

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

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

1994-03-01T23:59:59.000Z

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


141

Geochemical characterization of geothermal systems in the Great Basin:  

Open Energy Info (EERE)

characterization of geothermal systems in the Great Basin: characterization of geothermal systems in the Great Basin: Implications for exploration, exploitation, and environmental issues Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Geochemical characterization of geothermal systems in the Great Basin: Implications for exploration, exploitation, and environmental issues Details Activities (0) Areas (0) Regions (0) Abstract: The objective of this ongoing project is the development of a representative geochemical database for a comprehensive range of elemental and isotopic parameters (i.e., beyond the typical data suite) for a range of geothermal systems in the Great Basin. Development of this database is one of the first steps in understanding the nature of geothermal systems in the Great Basin. Of particular importance in the Great Basin is utilizing

142

Geochemical modeling of the Raft River geothermal field | Open Energy  

Open Energy Info (EERE)

Page Page Edit History Facebook icon Twitter icon » Geochemical modeling of the Raft River geothermal field Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Geochemical modeling of the Raft River geothermal field Details Activities (1) Areas (1) Regions (0) Abstract: The results to date of chemical modeling of the Raft River KGRA are presented. Earlier work indicated a northwest-southeast anomaly in the contours. Modeling techniques applied to more complete data allowed further definition of the anomaly. Models described in this report show the source of various minerals in the geothermal water. There appears to be a regional heat source that gives rise to uniform conductive heat flow in the region, but convective flow is concentrated near the upwelling in the Crook well

143

Version 4.00 of the MINTEQ geochemical code  

DOE Green Energy (OSTI)

The MINTEQ code is a thermodynamic model that can be used to calculate solution equilibria for geochemical applications. Included in the MINTEQ code are formulations for ionic speciation, ion exchange, adsorption, solubility, redox, gas-phase equilibria, and the dissolution of finite amounts of specified solids. Since the initial development of the MINTEQ geochemical code, a number of undocumented versions of the source code and data files have come into use at the Pacific Northwest Laboratory (PNL). This report documents these changes, describes source code modifications made for the Aquifer Thermal Energy Storage (ATES) program, and provides comprehensive listings of the data files. A version number of 4.00 has been assigned to the MINTEQ source code and the individual data files described in this report.

Eary, L.E.; Jenne, E.A.

1992-09-01T23:59:59.000Z

144

Version 4. 00 of the MINTEQ geochemical code  

DOE Green Energy (OSTI)

The MINTEQ code is a thermodynamic model that can be used to calculate solution equilibria for geochemical applications. Included in the MINTEQ code are formulations for ionic speciation, ion exchange, adsorption, solubility, redox, gas-phase equilibria, and the dissolution of finite amounts of specified solids. Since the initial development of the MINTEQ geochemical code, a number of undocumented versions of the source code and data files have come into use at the Pacific Northwest Laboratory (PNL). This report documents these changes, describes source code modifications made for the Aquifer Thermal Energy Storage (ATES) program, and provides comprehensive listings of the data files. A version number of 4.00 has been assigned to the MINTEQ source code and the individual data files described in this report.

Eary, L.E.; Jenne, E.A.

1992-09-01T23:59:59.000Z

145

Investigation of iron opacity experiment plasma gradients with synthetic data analyses  

Science Conference Proceedings (OSTI)

Experiments have been performed at Sandia National Laboratories Z-facility to validate iron opacity models relevant to the solar convection/radiation zone boundary. Sample conditions were measured by mixing Mg with the Fe and using Mg K-shell line transmission spectra, assuming that the plasma was uniform. We develop a spectral model that accounts for hypothetical gradients, and compute synthetic spectra to quantitatively evaluate the plasma gradient size that can be diagnosed. Two sample designs are investigated, assuming linear temperature and density gradients. First, Mg uniformly mixed with Fe enables temperature gradients greater than 10% to be detected. The second design uses Mg mixed into one side and Al mixed into the other side of the sample in an attempt to more accurately infer the sample gradient. Both temperature and density gradients as small as a few percent can be detected with this design. Experiments have successfully recorded spectra with the second design. In future research, the spectral model will be used to place bounds on gradients that exist in Z opacity experiments.

Nagayama, T.; Bailey, J. E.; Rochau, G. A.; Hansen, S. B. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Mancini, R. C. [Physics Department, University of Nevada, Reno, Nevada 89557 (United States); MacFarlane, J. J.; Golovkin, I. [Prism Computational Sciences, Madison, Wisconsin 53703 (United States)

2012-10-15T23:59:59.000Z

146

Gradient Projection Methods for Quadratic Programs and ...  

E-Print Network (OSTI)

Jul 30, 2003 ... Gradient Projection Methods for Quadratic Programs and Applications in Training Support Vector Machines. Thomas Serafini (serafini.thomas ...

147

Workshop on hydrologic and geochemical monitoring in the Long Valley Caldera: proceedings  

DOE Green Energy (OSTI)

A workshop reviewed the results of hydrologic and geochemical monitoring in the Long Valley caldera. Such monitoring is being done to detect changes in the hydrothermal system induced by ongoing magmatic and tectonic processes. Workshop participants discussed the need to instrument sites for continuous measurements of several parameters and to obtain additional hydrologic and chemical information from intermediate and deep drill holes. In addition to seismic and deformation monitoring, programs are currently in progress to monitor changes in the discharge characteristics of hot springs, fumaroles, and soil gases, as well as pressures and temperatures in wells. Some hydrochemical parameters are measured continuously, others are measured monthly or at longer intervals. This report summarizes the information presented at the hydrologic monitoring workshop, following the workshop agenda which was divided into four sessions: (1) overview of the hydrothermal system; (2) monitoring springs, fumaroles, and wells; (3) monitoring gas emissions; and (4) conclusions and recommendations.

Sorey, M.L.; Farrar, C.D.; Wollenberg, H.A.

1984-10-01T23:59:59.000Z

148

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

Open Energy Info (EERE)

Thermal Gradient Holes At Salt Wells Area (Bureau of Land Management, 2009) Thermal Gradient Holes At Salt Wells Area (Bureau of Land Management, 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Salt Wells Area (Bureau of Land Management, 2009) Exploration Activity Details Location Salt Wells Geothermal Area Exploration Technique Thermal Gradient Holes Activity Date 2008 - 2008 Usefulness not indicated DOE-funding Unknown Exploration Basis Vulcan increased exploration efforts in the summer and fall of 2008, during which time the company drilled two temperature gradient holes (86-15 O on Pad 1 and 17-16 O on Pad 3); conducted seismic, gravity and magnetotelluric surveys; and drilled deep exploration wells at Pads 6 and 8 and binary wells at Pads 1, 2, 4, and 7. Notes

149

Thermal Gradient Holes At Hot Springs Ranch Area (Szybinski, 2006) | Open  

Open Energy Info (EERE)

Thermal Gradient Holes At Hot Springs Ranch Area (Szybinski, 2006) Thermal Gradient Holes At Hot Springs Ranch Area (Szybinski, 2006) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Hot Springs Ranch Area (Szybinski, 2006) Exploration Activity Details Location Hot Springs Ranch Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness useful DOE-funding Unknown Notes 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

150

Geothermal gradient map of the United States  

Science Conference Proceedings (OSTI)

A geothermal gradient map is needed in order to determine the hot dry rock (HDR) geothermal resource of the United States. Based on published and unpublished data (including new measurements) the HDR program will produce updated gradient maps annually, to be used as a tool for resource evaluation and exploration. The 1980 version of this map is presented.

Kron, A.; Heiken, G.

1980-01-01T23:59:59.000Z

151

Effect of Gradient Sequencing on Copolymer Order?Disorder Transitions: Phase Behavior of Styrene/n-Butyl Acrylate Block and Gradient Copolymers  

SciTech Connect

We investigate the effect of gradient sequence distribution in copolymers on order-disorder transitions, using rheometry and small-angle X-ray scattering to compare the phase behavior of styrene/n-butyl acrylate (S/nBA) block and gradient copolymers. Relative to block sequencing, gradient sequencing increases the molecular weight necessary to induce phase segregation by over 3-fold, directly consistent with previous predictions from theory. Results also suggest the existence of both upper and lower order-disorder transitions in a higher molecular weight S/nBA gradient copolymer, made accessible by the shift in order-disorder temperatures from gradient sequencing. The combination of transitions is speculated to be inaccessible in S/nBA block copolymer systems due to their overlap at even modest molecular weights and also their location on the phase diagram relative to the polystyrene glass transition temperature. Finally, we discuss the potential impacts of polydispersity and chain-to-chain monomer sequence variation on gradient copolymer phase segregation.

Mok, Michelle M.; Ellison, Christopher J.; Torkelson, John M. (NWU); (UMM)

2012-11-14T23:59:59.000Z

152

A geochemical model of the Kilauea east rift zone | Open Energy Information  

Open Energy Info (EERE)

A geochemical model of the Kilauea east rift zone A geochemical model of the Kilauea east rift zone Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: A geochemical model of the Kilauea east rift zone Abstract N/A Author Donald Thomas Published Journal US Geological Survey Professional Paper 1350, 1987 DOI Not Provided Check for DOI availability: http://crossref.org Online Internet link for A geochemical model of the Kilauea east rift zone Citation Donald Thomas. 1987. A geochemical model of the Kilauea east rift zone. US Geological Survey Professional Paper 1350. (!) . Retrieved from "http://en.openei.org/w/index.php?title=A_geochemical_model_of_the_Kilauea_east_rift_zone&oldid=682589" Categories: Missing Required Information References Uncited References Geothermal References

153

Thermal Gradient Holes At Lightning Dock Area (Warpinski, Et Al., 2004) |  

Open Energy Info (EERE)

Thermal Gradient Holes At Lightning Dock Area Thermal Gradient Holes At Lightning Dock Area (Warpinski, Et Al., 2004) Exploration Activity Details Location Lightning Dock Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness not indicated DOE-funding Unknown Notes The awardee conducted seismic, gravity, resistivity, and airborne magnetic surveys, drilled temperature-gradient wells, and selected a location for a test well (52-7). The test well was drilled to a total depth of 770 m during 2003. Maximum temperatures approached 140degrees C and a short flow test suggested that a production well could be drilled to 600 m and produce economic volumes of 130-140degrees C fluid. A final assessment of the resource is currently being performed. References N. R. Warpinski, A. R. Sattler, R. Fortuna, D. A. Sanchez, J.

154

Geochemical equilibrium modeling of the Auburn Thermal Energy Storage Field Test  

DOE Green Energy (OSTI)

The objective of the study was to investigate some alternate reservoir damage mechanisms that may have contributed to the loss of well injectivity experienced at the Mobile field site. Specifically, this includes mineral precipitation and/or alteration resulting from: 1) increased temperatures and temperature gradients, 2) presence of oxygen, 3) fluid-fluid incompatibility (mixing of two different aquifer waters), and 4) fluid-rock imcompatibility (introducing foreign groundwaters into storage aquifer sedimentary matrix). The primary investigatory tool used in the study is an Electric Power Research Institute computer program (EQUILIB), which is based on equilibrium chemical thermodynamics. The computer code was utilized to simulate changes in mineralogy and groundwater chemistries due to the interaction of the sediment material and two differing aquifer waters at temperatures of 55/sup 0/C, 100/sup 0/C, and 150/sup 0/C. Conclusions are primarily based on the 55/sup 0/C results since this was the maximum operating temperature for the Auburn experiment.

Stottlemyre, J.A.; Smith, R.P.; Erikson, R.L.

1979-10-01T23:59:59.000Z

155

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

Science Conference Proceedings (OSTI)

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

Olander, D.R.

1984-08-01T23:59:59.000Z

156

Universal Gradient Methods for Convex Optimization Problems  

E-Print Network (OSTI)

Apr 18, 2013 ... methods (e.g. [9], [10], [1]), which increase the rate of convergence of the gradient schemes much above the limits of Black-Box Complexity ...

157

Separation of carbon nanotubes in density gradients  

DOE Patents (OSTI)

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

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

2012-02-07T23:59:59.000Z

158

Separation of carbon nanotubes in density gradients  

DOE Patents (OSTI)

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

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

2010-02-16T23:59:59.000Z

159

Stream sediment detailed geochemical survey for Date Creek Basin, Arizona  

SciTech Connect

Results of the Date Creek Basin detailed geochemical survey are reported. Field and laboratory data are reported for 239 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are displayed. A generalized geologic map of the area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. Based on stream sediment geochemical data, significant concentrations of uranium are restricted to the Anderson Mine area. The 84th percentile concentrations of U-FL, U-NT, and U-FL/U-NT combined with low thorium/U-NT values reflect increased mobility and enrichment of uranium in the carbonate host rocks of that area. Elements characteristically associated with the uranium mineralization include lithium and arsenic. No well defined diffusion halos suggesting outliers of similar uranium mineralization were observed from the stream sediment data in other areas of the Date Creek Basin. Significant concentrations of U-FL or U-NT found outside the mine area are generally coincident with low U-FL/U-NT values and high concentrations of zirconium, titanium, and phosphorus. This suggests that the uranium is related to a resistate mineral assemblage derived from surrounding crystalline igneous and metamorphic rocks.

Butz, T.R.; Tieman, D.J.; Grimes, J.G.; Bard, C.S.; Helgerson, R.N.; Pritz, P.M.

1980-06-30T23:59:59.000Z

160

The gradient flow in a twisted box  

E-Print Network (OSTI)

We study the perturbative behavior of the gradient flow in a twisted box. We apply this information to define a running coupling using the energy density of the flow field. We study the step-scaling function and the size of cutoff effects in SU(2) pure gauge theory. We conclude that the twisted gradient flow running coupling scheme is a valid strategy for step-scaling purposes due to the relatively mild cutoff effects and high precision.

Ramos, A

2013-01-01T23:59:59.000Z

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


161

Monitoring temperature conditions in recently drilled nonproductive industry boreholes in Oklahoma  

SciTech Connect

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.

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

1985-06-01T23:59:59.000Z

162

Modules based on the geochemical model PHREEQC for use in scripting and programming languages  

Science Conference Proceedings (OSTI)

The geochemical model PHREEQC is capable of simulating a wide range of equilibrium reactions between water and minerals, ion exchangers, surface complexes, solid solutions, and gases. It also has a general kinetic formulation that allows modeling of ... Keywords: C, C++, COM, Component object model, Fortran, Geochemical modeling, PHREEQC, Reactive-transport modeling

Scott R. Charlton; David L. Parkhurst

2011-10-01T23:59:59.000Z

163

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

SciTech Connect

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.

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

164

Diversity, Body Mass, and Latitudinal Gradients in Primates  

E-Print Network (OSTI)

gradients in regional diversity of New World birds. GlobalT. (2003). Assessment of the diversity of African primates.of the latitudinal diversity gradient. American Naturalist,

Harcourt, A. H.; Schreier, B. M.

2009-01-01T23:59:59.000Z

165

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

Science Conference Proceedings (OSTI)

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

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

2009-09-01T23:59:59.000Z

166

Thermal Gradient Holes At Hawthorne Area (Lazaro, Et Al., 2010) | Open  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Thermal Gradient Holes At Hawthorne Area (Lazaro, Et Al., 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Hawthorne Area (Lazaro, Et Al., 2010) Exploration Activity Details Location Hawthorne Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness useful DOE-funding Unknown Notes The Navy recently completed a temperature gradient hole (TGH) drilling campaign. Results suggest multiple resources may exist on HAD lands. To further define the shallow resource, the Navy will drill one or two

167

NIST/Industry Developed Temperature Tracking Device for ...  

Science Conference Proceedings (OSTI)

... The group intends to also erect a tower to mount one of the devices to better understand 3-D temperature gradient mapping strategies near the ...

2011-06-07T23:59:59.000Z

168

Development Of 2-Meter Soil Temperature Probes And Results Of...  

Open Energy Info (EERE)

Nevada, Usa edit Details Activities (1) Areas (1) Regions (0) Abstract: Temperature gradient drilling has historically been a key tool in the exploration for geothermal...

169

The hydrogeologic-geochemical model of Cerro Prieto revisited  

DOE Green Energy (OSTI)

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.

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

1989-01-01T23:59:59.000Z

170

Holocene deposition in Northwest Providence Channel, Bahamas: a geochemical approach  

SciTech Connect

The origins and depositional history of Holocene sediment in Northwest Providence Channel, Bahamas (NWPC) have been determined using geochemical measurements coupled with textural data, petrographic examination, and scanning electron microscopy. Most of the channel is 200 to 2000 m deep, and nearly 100% of the sediment is calcium carbonate. Shallow water platform sources contribute 75-90% of the Holocene sediment in NWPC. Bank derived sand is most abundant near the platforms (nearly 100%) and is concentrically distributed around a central area of abundant non-platform sand. Bank-derived mud (<62 ..mu..m) accounts for more than 80% of the mud fraction in NWPC. The coarse silt (62-16 ..mu..m), fine silt (16-4 ..mu..m) and clay (< 4 ..mu..m) fractions from LLB (Bight of Abaco) are geochemically distinct from the mud fractions of Great Bahama Bank (GBB). Their distributions in NWPC demonstrate that both platforms are significant sediment contributors to NWPC. The observed sediment distribution clearly indicates that significant off bank transport occurs. With regard to sediment transport, no windward or leeward effects are observed in Holocene sediment deposition. Gravity flow processes are not significant to Holocene deposition. 80% of the present sedimentation rate results from the banktop flooding and confirms that 75%-90% of the Holocene sediment is derived from platform sources. The C-14 dated Holocene sediment layer is approximately 50 cm thick, and its transition with the Pleistocene occurs over a vertical interval of less than 20 cm as a result of mixing by benthonic organisms. This Holocene sediment layer should remain intact to permanently record this banktop episode, and should have a different diagenetic future from the underlying stable (calcite-rich) sediment.

Boardman, M.R.

1978-01-01T23:59:59.000Z

171

U.S. DEPARTlVIENT OF ENERGY EERE PROJECT MANAGEMENT CENTER NEPA...  

NLE Websites -- All DOE Office Websites (Extended Search)

, geophysical (such as gravity, magnetic, electrical, seismic, radar, and temperature gradient), geochemical , and engineering surveys and mapping, and the establishment of...

172

U.S. DEPARTl\\IIENT OF ENERGY EERE PROJECT MANAGEMENT CENTER  

NLE Websites -- All DOE Office Websites (Extended Search)

geophysical (such as gravity, magnetic, electrical, seismic, radar, and temperature gradient), geochemical, and engineering surveys and mapping, and the establishment of...

173

U.S. DEPARTMENT OF ENERGY EERE PROJECT MANAGEMENT CENTER NEPA...  

NLE Websites -- All DOE Office Websites (Extended Search)

geophysical (such as gravity, magnetic, electrical , seismic, radar, and temperature gradient) , geochemical , and engineering surveys and mapping, and the establishment of...

174

Thermal Gradient Holes | Open Energy Information  

Open Energy Info (EERE)

Thermal Gradient Holes Thermal Gradient Holes Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Thermal Gradient Holes Details Activities (50) Areas (39) Regions (4) NEPA(29) Exploration Technique Information Exploration Group: Drilling Techniques Exploration Sub Group: Exploration Drilling Parent Exploration Technique: Exploration Drilling Information Provided by Technique Lithology: Stratigraphic/Structural: Hydrological: Field wide fluid flow characteristics if an array of wells are drilled Thermal: Mapping and projecting thermal anomalies Cost Information Low-End Estimate (USD): 5.00500 centUSD 0.005 kUSD 5.0e-6 MUSD 5.0e-9 TUSD / foot Median Estimate (USD): 16.501,650 centUSD 0.0165 kUSD 1.65e-5 MUSD 1.65e-8 TUSD / foot High-End Estimate (USD): 50.005,000 centUSD

175

Steep Gradient Flume | Open Energy Information  

Open Energy Info (EERE)

Steep Gradient Flume Steep Gradient Flume Jump to: navigation, search Basic Specifications Facility Name Steep Gradient Flume Overseeing Organization University of Iowa Hydrodynamic Testing Facility Type Flume Length(m) 20.1 Beam(m) 0.9 Depth(m) 0.5 Cost(per day) Contact POC Special Physical Features Tilting flume from -1.5 to +16% slope; <3mm sedimentation recirculation capabilities; instrumentation rails Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities None Channel/Tunnel/Flume Channel/Tunnel/Flume Yes Recirculating Yes Wind Capabilities Wind Capabilities None Control and Data Acquisition Cameras Yes Number of Color Cameras 1 Available Sensors Acoustics, Flow, Thermal, Turbulence, Velocity Data Generation Capability Real-Time Yes

176

METALLICITY GRADIENTS OF THICK DISK DWARF STARS  

Science Conference Proceedings (OSTI)

We examine the metallicity distribution of the Galactic thick disk using F, G, and K dwarf stars selected from the Sloan Digital Sky Survey, Data Release 8. Using the large sample of dwarf stars with proper motions and spectroscopically determined stellar parameters, metallicity gradients in the radial direction for various heights above the Galactic plane and in the vertical direction for various radial distances from the Galaxy center have been found. In particular, we find a vertical metallicity gradient of -0.113 {+-} 0.010 (-0.125 {+-} 0.008) dex kpc{sup -1} using an isochrone (photometric) distance determination in the range 1 kpc solar neighborhood. Metallicity gradients in the thin and thick disks are important probes into possible formation scenarios for our Galaxy and a consistent picture is beginning to emerge from results using large spectroscopic surveys, such as the ones presented here.

Carrell, Kenneth; Chen Yuqin; Zhao Gang, E-mail: carrell@nao.cas.cn [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

2012-12-01T23:59:59.000Z

177

Soil Carbon Dynamics Along an Elevation Gradient in the Southern Appalachian Mountains  

Science Conference Proceedings (OSTI)

The role of soil C dynamics in the exchange of CO{sub 2} between the terrestrial biosphere and the atmosphere is at the center of many science questions related to global climate change. The purpose of this report is to summarize measured trends in environmental factors and ecosystem processes that affect soil C balance along elevation gradients in the southern Appalachian Mountains of eastern Tennessee and western North Carolina, USA. Three environmental factors that have potentially significant effects on soil C dynamics (temperature, precipitation, and soil N availability) vary in a predictable manner with altitude. Forest soil C stocks and calculated turnover times of labile soil C increase with elevation, and there is an apparent inverse relationship between soil C storage and mean annual temperature. Relationships between climate variables and soil C dynamics along elevation gradients must be interpreted with caution because litter chemistry, soil moisture, N availability, and temperature are confounded; all potentially interact in complex ways to regulate soil C storage through effects on decomposition. Some recommendations are presented for untangling these complexities. It is concluded that past studies along elevation gradients have contributed to a better but not complete understanding of environmental factors and processes that potentially affect soil C balance. Furthermore, there are advantages linked to the use of elevation gradients as an approach to climate change research when hypotheses are placed in a strong theoretical or mechanistic framework. Climate change research along elevation gradients can be both convenient and economical. More importantly, ecosystem processes and attributes affecting soil C dynamics along elevation gradients are usually the product of the long-term interactions between climate, vegetation, and soil type. Investigations along elevation gradients are a useful approach to the study of environmental change, and its effect on soil processes, which can complement data obtained from controlled, large-scale, field experiments as well as other empirical and theoretical approaches to climate change research.

Garten Jr., C.T.

2004-04-13T23:59:59.000Z

178

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

DOE Green Energy (OSTI)

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

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

1992-02-01T23:59:59.000Z

179

High-pressure liquid chromatographic gradient mixer  

DOE Patents (OSTI)

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

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

1982-09-08T23:59:59.000Z

180

Thermal Gradient Holes At Upper Hot Creek Ranch Area (Benoit & Blackwell,  

Open Energy Info (EERE)

Hot Creek Ranch Area (Benoit & Blackwell, Hot Creek Ranch Area (Benoit & Blackwell, 2006) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Upper Hot Creek Ranch Area (Benoit & Blackwell, 2006) Exploration Activity Details Location Upper Hot Creek Ranch Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness not useful DOE-funding Unknown Notes Ten temperature gradient holes up to 500' deep were initially planned but higher than anticipated drilling and permitting costs within a fixed budget reduced the number of holes to five. Four of the five holes drilled to depths of 300 to 400' encountered temperatures close to the expected regional thermal background conditions. These four holes failed to find any evidence of a large thermal anomaly surrounding the UHCR hot springs. The

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


181

Multi-gradient drilling method and system  

DOE Patents (OSTI)

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

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

2003-01-01T23:59:59.000Z

182

Joining of Tungsten Armor Using Functional Gradients  

SciTech Connect

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

John Scott O'Dell

2006-12-31T23:59:59.000Z

183

Gradient zone-boundary control in salt-gradient solar ponds  

DOE Patents (OSTI)

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

Hull, J.R.

1982-09-29T23:59:59.000Z

184

A ONE-DIMENSIONAL, ONE-PHASE STEFAN PROBLEM AS GRADIENT FLOW  

E-Print Network (OSTI)

zero. The evolution of the water temperature and of the phase transition wall (water/ice free boundaryA ONE-DIMENSIONAL, ONE-PHASE STEFAN PROBLEM AS GRADIENT FLOW Adrian Tudorascu Department reasonable assumptions on the initial data, we expect the classi- cal solution for the one-phase Stefan

185

Geochemical Data on Waters, Gases, Scales, and Rocks from the Dixie Valley  

Open Energy Info (EERE)

Geochemical Data on Waters, Gases, Scales, and Rocks from the Dixie Valley Geochemical Data on Waters, Gases, Scales, and Rocks from the Dixie Valley Region, Nevada (1996-1999) 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) Abstract This report tabulates an extensive geochemical database on waters, gases, scales,rocks, and hot-spring deposits from the Dixie Valley region, Nevada. The samples fromwhich the data were obtained were collected and analyzed during 1996 to 1999. Thesedata provide useful information for ongoing and future investigations on geothermalenergy, volcanism, ore deposits, environmental issues, and groundwater quality in thisregion. Authors Los Alamos National Laboratory and NM Published

186

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

E-Print Network (OSTI)

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 ...

Huang, Shichun

2005-01-01T23:59:59.000Z

187

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

E-Print Network (OSTI)

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 ...

Gregg, Patricia Michelle Marie

2008-01-01T23:59:59.000Z

188

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

E-Print Network (OSTI)

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 ...

Walther, Benjamin (Benjamin Dwaine)

2007-01-01T23:59:59.000Z

189

A linear helicon plasma device with controllable magnetic field gradient  

Science Conference Proceedings (OSTI)

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

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

2012-06-15T23:59:59.000Z

190

Hydrodynamic gradient expansion in gauge theory plasmas  

E-Print Network (OSTI)

We utilize the fluid-gravity duality to investigate the large order behavior of hydrodynamic gradient expansion of the dynamics of a gauge theory plasma system. This corresponds to the inclusion of dissipative terms and transport coefficients of very high order. Using the dual gravity description, we calculate numerically the form of the stress tensor for a boost-invariant flow in a hydrodynamic expansion up to terms with 240 derivatives. We observe a factorial growth of gradient contributions at large orders, which indicates a zero radius of convergence of the hydrodynamic series. Furthermore, we identify the leading singularity in the Borel transform of the hydrodynamic energy density with the lowest nonhydrodynamic excitation corresponding to a `nonhydrodynamic' quasinormal mode on the gravity side.

Michal P. Heller; Romuald A. Janik; Przemyslaw Witaszczyk

2013-02-04T23:59:59.000Z

191

Automated apparatus for producing gradient gels  

DOE Patents (OSTI)

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

Anderson, Norman L. (Clarendon Hills, IL)

1986-01-01T23:59:59.000Z

192

Direct Evidence of “Sheets” in the Atmospheric Temperature Field  

Science Conference Proceedings (OSTI)

This paper presents experimental evidence showing the ubiquitous presence in the lower atmosphere (at least up to 25 km) of very strong (positive) temperature gradients within very thin layers. The presence of such “sheets” in the temperature ...

Francis Dalaudier; Claude Sidi; Michel Crochet; Jean Vernin

1994-01-01T23:59:59.000Z

193

Energy Gradient Theory of Hydrodynamic Instability  

E-Print Network (OSTI)

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

Hua-Shu Dou

2005-01-28T23:59:59.000Z

194

Thermal Gradient Holes At Hualalai Northwest Rift Area (Thomas, 1986) |  

Open Energy Info (EERE)

Hualalai Northwest Rift Hualalai Northwest Rift Area (Thomas, 1986) Exploration Activity Details Location Hualalai Northwest Rift Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness not useful DOE-funding Unknown Notes Although not part of the current effort, two deep (approximately 2000 m) exploratory wells were drilled on the north flank of Hualalai near Puu Waawaa cinder cone. The geophysical data used for siting these wells were proprietary and hence unavailable for publication; however, the temperatures measured at the bottoms of the wells were reported to be below 20degrees C. Chemical analysis of water samples taken from these wells did not provide useful geothermal data due to contamination of the well water with drilling muds References Donald M. Thomas (1 January 1986) Geothermal Resources Assessment In

195

GEOCHEMICAL MODELING OF F AREA SEEPAGE BASIN COMPOSITION AND VARIABILITY  

SciTech Connect

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.

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

2012-05-08T23:59:59.000Z

196

Irradiance gradients in the presence of participating media and occlusions  

Science Conference Proceedings (OSTI)

In this paper we present a technique for computing translational gradients of indirect surface reflectance in scenes containing participating media and significant occlusions. These gradients describe how the incident radiance field changes with respect ...

Wojciech Jarosz; Matthias Zwicker; Henrik Wann Jensen

2008-06-01T23:59:59.000Z

197

Mixed Layer Restratification Due to a Horizontal Density Gradient  

Science Conference Proceedings (OSTI)

The restratification in the surface mixed layer driven by a horizontal density gradient following a storm is examined. For a constant layer depth H and constant buoyancy gradient |bx| = M2, geostrophic adjustment leads to new stratification with ...

Amit Tandon; Chris Garrett

1994-06-01T23:59:59.000Z

198

Alternatives to the gradient in optimal transfer line buffer allocation  

E-Print Network (OSTI)

This thesis describes several directions to replace the gradient in James Schor's gradient algorithm to solve the dual problem. The alternative directions are: the variance and standard deviation of buffer levels, the ...

Tanizar, Ketty, 1978-

2004-01-01T23:59:59.000Z

199

Geochemical interpretation of Kings Mountain, North Carolina, orientation area  

SciTech Connect

An orientation study has been made of uranium occurrences in the area of Kings Mountain, North Carolina. This is one of the orientation studies of known uranium occurrences that are being conducted in several geologic provinces and under various climatic (weathering) conditions to provide the technical basis for design and interpretation of NURE geochemical reconnaissance programs. The Kings Mountain area was chosen for study primarily because of the reported presence of high-uranium monazite. This 750-mi/sup 2/ area is in the deeply weathered southern Appalachian Piedmont and spans portions of the Inner Piedmont, Kings Mountain, and Charlotte geologic belts. Uranium concentration maps for ground and surface water samples clearly outline the outcrop area of the Cherryville Quartz Monzonite with highs up to 10 ppb uranium near the reported uraninite. Several surface water samples appear to be anomalous because of trace industrial contamination. Uranium concentration maps for -100 to +200 mesh stream sediments indicate the area of monazite abundance. Several samples with >100 ppM uranium content appear to be high in uranium-rich resistate minerals. When the uranium content of sediment samples is ratioed to the sum of Hf, Dy, and Th, the anomaly pattern shifts to coincide with uranium highs in ground and surface water samples. False anomalies from concentrations of monazite (Ce,ThPO/sub 4/), xenotime (Y,DyPO/sub 4/), and zircon (Zr,HfSiO/sub 4/) in stream sediment samples can thus be eliminated. Residual anomalies should be related to unusual uranium enrichment of these common minerals or to the presence of an uncommon uranium-rich mineral. Tantalum, beryllium, and tin in stream sediments correspond to high concentrations of uranium in stream and ground water but not to uranium in sediments. In an initial reconnaissance, several media should be sampled, and it is essential to correct uranium in sediments for the sample mineralogy.

Price, V.; Ferguson, R.B.

1977-01-01T23:59:59.000Z

200

Origin and geochemical evolution of the Michigan basin brine  

Science Conference Proceedings (OSTI)

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.

Wilson, T.P.

1989-01-01T23:59:59.000Z

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


201

Thermal Gradient Holes At Blue Mountain Area (Fairbank & Neggemann...  

Open Energy Info (EERE)

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

202

The long range migration of hydrogen through Zircaloy in response to tensile and compressive stress gradients  

DOE Green Energy (OSTI)

Zircaloy-4, which is used widely as a core structural material in pressurized water reactors (PWRs), picks up hydrogen during service. Hydrogen solubility in Zircaloy-4 is low and zirconium hydride phases precipitate after the Zircaloy-4 lattice becomes supersaturated with hydrogen. These hydrides embrittle the Zircaloy-4, degrading its mechanical performance as a structural material. Because hydrogen can move rapidly through the Zircaloy-4 lattice, the potential exists for large concentrations of hydride to accumulate in local regions of a Zircaloy component remote from its point of entry into the component. Much has been reported in the literature regarding the long range migration of hydrogen through Zircaloy under concentration gradients and temperature gradients. Relatively little has been reported, however, regarding the long range migration of hydrogen under stress gradients. This paper presents experimental results regarding the long range migration of hydrogen through Zircaloy in response to both tensile and compressive stress gradients. The importance of this driving force for hydrogen migration relative to concentration and thermal gradients is discussed.

Kammenzind, B.F.; Berquist, B.M.; Bajaj, R.; Kreyns, P.H.; Franklin, D.G.

1998-11-01T23:59:59.000Z

203

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

DOE Green Energy (OSTI)

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.

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

2004-05-24T23:59:59.000Z

204

A Mineralogical Petrographic And Geochemical Study Of Samples From Wells In  

Open Energy Info (EERE)

Mineralogical Petrographic And Geochemical Study Of Samples From Wells In Mineralogical Petrographic And Geochemical Study Of Samples From Wells In The Geothermal Field Of Milos Island (Greece) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Mineralogical Petrographic And Geochemical Study Of Samples From Wells In The Geothermal Field Of Milos Island (Greece) Details Activities (0) Areas (0) Regions (0) Abstract: This paper presents a study of hydrothermal alteration on Milos island, Greece. Examination of cores and cuttings from the two drill sites, obtained from a depth of about 1100 m in Milos geothermal field, showed that the hydrothermal minerals occurring in the rock include: K-feldspar, albite, chlorite, talc, diopside, epidote, muscovite, tremolite, kaolinite, montmorillonite, alunite, anhydrite, gypsum, calcite, and opaque minerals.

205

A Reconnaissance Geochemical Study Of La Primavera Geothermal...  

Open Energy Info (EERE)

1100 and 1560 mgkg after flashing. Neither of the high-temperature wells produced steam in commercial quantities. The well at the western margin of the Sierra produced fluids...

206

Trace metal speciation in saline waters affected by geothermal brines. [GEOCHEM  

DOE Green Energy (OSTI)

A description is given of the chemical equilibrium computer program GEOCHEM, which has been developed to calculate trace element speciation in soil, irrigation, drainage, or Salton Sea waters affected by geothermal brine. GEOCHEM is applied to irrigation water-brine mixtures and to Salton Sea water-brine mixtures in order to compute the chemical speciation of the elements Cd, Cu, Hg, Ni, Pb, and Zn, along with the oxyanions of As and B. The results suggest that the computer simulation can have an important effect on a program for managing brine spills. Appendices include published papers on related research.

Sposito, G.; Page, A.L.

1977-11-01T23:59:59.000Z

207

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

SciTech Connect

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.

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

2013-03-01T23:59:59.000Z

208

H-mode threshold power scaling and the {gradient}B drift effect  

Science Conference Proceedings (OSTI)

One of the largest influences on the H-mode power threshold (P{sub TH}) is the direction of the ion {gradient}B drift relative to the X-point location, where factors of 2--3 increase in P{sub TH} are observed for the ion {gradient}B drift away from the X-point. It is proposed that the threshold power scaling observed in single-null configurations with the ion {gradient}B drift toward the X-point location (P{sub TH} {approximately} nB, where n is the plasma density, and B is the toroidal field) is due to the scaling of the magnitude of the {gradient}B drift effect. Hinton and later Hinton and Stebler have modeled this effect as neoclassical cross field fluxes of both heat and particles driven by poloidal temperature gradients on the open field lines in the scrape-off layer (SOL). The {gradient}B drift effect influences the power threshold by affecting the edge conditions needed for the L-H transition. It is not essential for the L-H transition itself since transitions are observed with either direction of B. Predictions of this model include saturation of the B scaling of P{sub TH} at high field, 1/B scaling of P{sub TH} with reverse B, and no B scaling of P{sub TH} in balanced double-null configurations. This last prediction is consistent with the observed scaling of p{sub TH} in double-null plasma sin DIII-D.

Carlstrom, T.N.; Burrell, K.H.; Groebner, R.J.; Staebler, G.M.

1997-06-01T23:59:59.000Z

209

Constant field gradient planar cavity structure  

DOE Patents (OSTI)

A cavity structure is described 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.

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

1997-12-01T23:59:59.000Z

210

High-gradient compact linear accelerator  

DOE Patents (OSTI)

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

Carder, B.M.

1995-12-31T23:59:59.000Z

211

Geochemical Journal, Vol. 39, pp. 383 to 389, 2005 *Corresponding author (e-mail: ytakaha@hiroshima-u.ac.jp)  

E-Print Network (OSTI)

383 Geochemical Journal, Vol. 39, pp. 383 to 389, 2005 *Corresponding author (e-mail: ytakaha@hiroshima,3 1 Department of Earth & Planetary Systems Science, Hiroshima University, Higashi-Hiroshima 739 for Multiple Isotope Research for Astro-and Geochemical Evolution (MIRAGE), Hiroshima University, Higashi-Hiroshima

212

GeoSys.Chem: Estimate of reservoir fluid characteristics as first step in geochemical modeling of geothermal systems  

Science Conference Proceedings (OSTI)

A computer code GeoSys.Chem for the calculation of deep geothermal reservoir fluid characteristics from the measured physical-chemical parameters of separated water and condensed vapor samples obtained from drilled wells is presented. It was written ... Keywords: GeoChem, GeoSys.Chem, Geochemical modeling, Los Azufres, VB.NET

Mahendra P. Verma

2012-12-01T23:59:59.000Z

213

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

E-Print Network (OSTI)

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

Codina Cotar; Jean-Dominique Deuschel; Stefan Müller

2008-01-08T23:59:59.000Z

214

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

The Alternating Gradient Synchrotron The Alternating Gradient Synchrotron Photo of the Week: The Alternating Gradient Synchrotron March 11, 2013 - 6:00pm Addthis Since 1960, the Alternating Gradient Synchrotron (AGS) has been one of the world's premiere particle accelerators, well known for the three Nobel Prizes won as a result of research performed there. The AGS name is derived from the concept of alternating gradient focusing, in which the field gradients of the accelerator's 240 magnets are successively alternated inward and outward, permitting particles to be propelled and focused in both the horizontal and vertical plane at the same time. In this 1958 photo, giant magnets await installation into the AGS accelerator ring tunnel at Brookhaven National Laboratory. | Photo courtesy of Brookhaven National Laboratory.

215

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

The Alternating Gradient Synchrotron The Alternating Gradient Synchrotron Photo of the Week: The Alternating Gradient Synchrotron March 11, 2013 - 6:00pm Addthis Since 1960, the Alternating Gradient Synchrotron (AGS) has been one of the world's premiere particle accelerators, well known for the three Nobel Prizes won as a result of research performed there. The AGS name is derived from the concept of alternating gradient focusing, in which the field gradients of the accelerator's 240 magnets are successively alternated inward and outward, permitting particles to be propelled and focused in both the horizontal and vertical plane at the same time. In this 1958 photo, giant magnets await installation into the AGS accelerator ring tunnel at Brookhaven National Laboratory. | Photo courtesy of Brookhaven National Laboratory.

216

High Thermal Gradient Directional Solidification with Liquid Metal ...  

Science Conference Proceedings (OSTI)

Presentation Title, High Thermal Gradient Directional Solidification with Liquid Metal Cooling and Its Application in the Processing of Nickel-Based Superalloys.

217

An accelerated proximal gradient algorithm for nuclear norm  

E-Print Network (OSTI)

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

218

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

Open Energy Info (EERE)

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

219

Thermal Gradient Holes At Mccoy Geothermal Area (DOE GTP) | Open...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Mccoy Geothermal Area (DOE GTP) Exploration Activity Details...

220

Thermal Gradient Holes At Pilgrim Hot Springs Area (DOE GTP)...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Pilgrim Hot Springs Area (DOE GTP) Exploration Activity Details...

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


221

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

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Lake City Hot Springs Area (Warpinski, Et Al., 2004) Exploration...

222

Thermal Gradient Holes At Long Valley Caldera Area (Sorey, Et...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Long Valley Caldera Area (Sorey, Et Al., 1991) Exploration Activity...

223

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

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Upper Hot Creek Ranch Area (Benoit & Blackwell, 2006) Exploration...

224

Thermal Gradient Holes At Obsidian Cliff Area (Hulen, Et Al....  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Obsidian Cliff Area (Hulen, Et Al., 2003) Exploration Activity...

225

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

Open Energy Info (EERE)

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

226

Thermal Gradient Holes At Newberry Caldera Area (DOE GTP) | Open...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Newberry Caldera Area (DOE GTP) Exploration Activity Details...

227

Thermal Gradient Holes At San Emidio Desert Area (DOE GTP) |...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At San Emidio Desert Area (DOE GTP) Exploration Activity Details...

228

Thermal Gradient Holes At Flint Geothermal Area (DOE GTP) | Open...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Flint Geothermal Area (DOE GTP) Exploration Activity Details...

229

Thermal Gradient Holes At Spencer Hot Springs Area (Shevenell...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Spencer Hot Springs Area (Shevenell, Et Al., 2008) Exploration...

230

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

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Walker-Lane Transitional Zone Region (Pritchett, 2004) Exploration...

231

Thermal Gradient Holes At Mcgee Mountain Area (DOE GTP) | Open...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Mcgee Mountain Area (DOE GTP) Exploration Activity Details Location...

232

DC Resistivity Survey (Gradient Array) | Open Energy Information  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: DC Resistivity Survey (Gradient Array) edit Details Activities (0) Areas (0) Regions (0)...

233

Fundamental Limits to Position Determination by Concentration Gradients  

E-Print Network (OSTI)

Position determination in biological systems is often achieved through protein concentration gradients. Measuring the local concentration of such a protein with a spatially-varying distribution allows the measurement of position within the system. In order for these systems to work effectively, position determination must be robust to noise. Here, we calculate fundamental limits to the precision of position determination by concentration gradients due to unavoidable biochemical noise perturbing the gradients. We focus on gradient proteins with first order reaction kinetics. Systems of this type have been experimentally characterised in both developmental and cell biology settings. For a single gradient we show that, through time-averaging, great precision can potentially be achieved even with very low protein copy numbers. As a second example, we investigate the ability of a system with oppositely directed gradients to find its centre. With this mechanism, positional precision close to the centre improves more slowly with increasing averaging time, and so longer averaging times or higher copy numbers are required for high precision. For both single and double gradients, we demonstrate the existence of optimal length scales for the gradients, where precision is maximized, as well as analyzing how precision depends on the size of the concentration measuring apparatus. Our results provide fundamental constraints on the positional precision supplied by concentration gradients in various contexts, including both in developmental biology and also within a single cell.

Filipe Tostevin; Pieter Rein ten Wolde; Martin Howard

2007-04-26T23:59:59.000Z

234

Better Mini-Batch Algorithms via Accelerated Gradient Methods  

E-Print Network (OSTI)

Better Mini-Batch Algorithms via Accelerated Gradient Methods Andrew Cotter Toyota Technological Toyota Technological Institute at Chicago nati@ttic.edu Karthik Sridharan Toyota Technological Institute

235

Engineering chemoattractant gradients using controlled release polysaccharide microspheres  

E-Print Network (OSTI)

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

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

2012-01-01T23:59:59.000Z

236

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

E-Print Network (OSTI)

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

237

Evaluation of the Miamsburg Salt-Gradient, Solar Pond  

SciTech Connect

This project is directed toward data collection and evaluation of the performance of the largest working, salt-gradient, solar pond in the world.

Wittenberg, Layton J.

1978-09-01T23:59:59.000Z

238

Chemie der Erde 65 (2005) 4778 Geochemical and isotopic characteristics and evolution of the  

E-Print Network (OSTI)

Chemie der Erde 65 (2005) 47­78 Geochemical and isotopic characteristics and evolution) and Pichowiak (1994). ARTICLE IN PRESS W. Kramer et al. / Chemie der Erde 65 (2005) 47­7848 #12;These east (Oficina Viz Fm.) on a wide front to the west (Caleta Ligate Fm.). W. Kramer et al. / Chemie der

Siebel, Wolfgang

239

Modeling of concentrated aqueous solutions: Efficient implementation of Pitzer equations in geochemical and reactive transport models  

Science Conference Proceedings (OSTI)

Modeling concentrated solutions demands the use of ion-interaction models such as Pitzer equations, which involve a large number of operations. Implementation of these models in large reactive transport simulations significantly increases the computation ... Keywords: Concentrated solutions, Evaporation of seawater, Geochemical modeling, HMW model, Invariant points, Object-oriented programming, Pitzer, Reactive transport modeling

S. A. Bea; J. Carrera; C. Ayora; F. Batlle

2010-04-01T23:59:59.000Z

240

Geochemical Implications of Gas Leakage Associated with Geologic CO2 Storage - A Qualitative Review  

SciTech Connect

Leakage from deep storage reservoirs is considered the major risk factor associated with geologic sequestration of CO2. Different schools of thought exist concerning the potential implications of such leakage for near-surface environments. We reviewed the current literature on how CO2 leakage (from storage reservoirs) would likely impact the geochemistry of overlying potable aquifers. Results from experimental and modeling studies point to the potential for both beneficial (e.g. contaminant immobilization) and deleterious (e.g. contaminant mobilization) consequences of CO2 intrusion into potable groundwater. However, there are significant discrepancies between studies particularly concerning, what contaminants are of concern and the geochemical processes involved. These discrepancies reflected the lack of a consensus on CO2-induced changes in subsurface geochemical processes and subsequent effects on groundwater chemistry. The development of consistent experimental protocols and the identification of pertinent factors driving CO2-induced geochemical changes in the subsurface were identified as key research needs. Geochemical modeling was used to systematically highlight why a standardization of experimental protocols and the consideration of experimental factors such as gas leakage rates, redox status and the influence of co-transported gases are pertinent. The role of analog studies, reactions occurring in the vadose zone, and the influence of organic contaminants are also discussed.

Harvey, Omar R.; Qafoku, Nikolla; Cantrell, Kirk J.; Lee, Gie Hyeon; Amonette, James E.; Brown, Christopher F.

2013-01-01T23:59:59.000Z

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


241

Geochemical constraints on the Palaeocene^ Miocene evolution of eastern Azerbaijan, with  

E-Print Network (OSTI)

Geochemical constraints on the Palaeocene^ Miocene evolution of eastern AzerbaijanEarth and Environmental Sciences, University of Texas at Arlington, Arlington,TX, USA zAzerbaijan NationalAcademy of Sciences Geology Institute ^ 29 A. H. Javid Pr., Baku, Azerbaijan ABSTRACT Fine-grained Palaeogene

Johnson, Cari

242

Geochemical modeling of the nuclear-waste repository system. A status report  

Science Conference Proceedings (OSTI)

The primary objective of the geochemical modeling task is to develop an understanding of the waste-repository geochemical system and provide a valuable tool for estimating future states of that system. There currently exists a variety of computer codes which can be used in geochemical modeling studies. Some available codes contain the framework for simulating a natural chemical system and estimating, within limits, the response of that system to environmental changes. By data-base enhancement and code development, this modeling technique can be even more usefully applied to a nuclear-waste repository. In particular, thermodynamic data on elements not presently in the data base but identified as being of particular hazard in the waste-repository system, need to be incorporated into the code to estimate the near-field as well as the far-field reactions during a hypothetical breach. A reaction-path-simulation code, which estimates the products of specific rock/water reactions, has been tested using basalt and ground water. Results show that the mass-transfer capabilities of the code will be useful in chemical-evolution studies and scenario analyses. The purpose of this report is to explain the status of geochemical modeling as it currently applies to the chemical system of a hypothetical nuclear-waste repository in basalt and to present the plan proposed for further developmet and application.

Deutsch, W.J.

1980-12-01T23:59:59.000Z

243

Geochemical anomalies in soil and sandstone overlying the Phoenix uranium deposit, Athabasca Basin Natural Resources  

E-Print Network (OSTI)

Collaboration Introduction The Wheeler River Property, host of Denison Mine's Phoenix uranium depositCo Mo Ni UU Geochemical anomalies in soil and sandstone overlying the Phoenix uranium deposit is the most efficient analytical method to detect these anomalies. Athabasca Basin Figure 1: Denison Mine

244

Soil geochemical survey over concealed kimberlites in the Attawapiskat area in northern Canada  

E-Print Network (OSTI)

lengths of 562 m over the Whiskey kimberlite and 740 m over the Yankee kimberlite pipe. B-horizon soil of the kimberlite pipes. Ammonium acetate leach at pH 5 (AA5) dissolves most of these carbonates, and shows geochemical characteristics of kimberlites in com- parison with peridotites, oceanic basalts (MORB

245

Z .Chemical Geology 145 1998 153159 z /Geochemical Earth Reference Model GERM  

E-Print Network (OSTI)

Z .Chemical Geology 145 1998 153­159 z /Geochemical Earth Reference Model GERM : description on a chemical characterization of the Earth, its major reservoirs, and the fluxes between them. The Z .GERM chemical Z . Z .reservoirs of the present-day Earth, from core to atmosphere; 2 present-day fluxes between

Mcdonough, William F.

246

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

247

Oak Ridge Geochemical Reconnaissance Program. [For National Uranium Resource Evaluation Program  

SciTech Connect

The Oak Ridge reconnaissance program is responsible for the geochemical survey in a 12-state area covering Texas, Oklahoma, Kansas, Nebraska, South Dakota, North Dakota, Minnesota, Wisconsin, Michigan, Iowa, Indiana, and Illinois as part of the National Uranium Resource Evaluation Program. The program concept is outlined and the planning and organization of the program is discussed. (JSR)

Arendt, J.W.

1977-03-01T23:59:59.000Z

248

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

DOE Patents (OSTI)

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

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

2000-01-01T23:59:59.000Z

249

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

Science Conference Proceedings (OSTI)

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} 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.

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

250

Exploration geothermal gradient drilling, Platanares, Honduras, Central America  

DOE Green Energy (OSTI)

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

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

1988-01-01T23:59:59.000Z

251

Multi-objective Optimization Design for Gradient Stiffness Leaf Spring  

Science Conference Proceedings (OSTI)

Gradient stiffness leaf spring is of a positive meaning for increasing the ride smooth of vehicle, which has a more stable natural frequency of leaf spring stiffness. A multi-objective optimization model of Gradient stiffness leaf spring of vehicles ... Keywords: leaf spring, multi-objective, optimization design

Qin-man Fan

2011-04-01T23:59:59.000Z

252

Interpreting Conductivity Microstructure: Estimating the Temperature Variance Dissipation Rate  

Science Conference Proceedings (OSTI)

A simple model of the conductivity gradient spectrum is developed and used to interpret oceanic conductivity microstructure observations. A principal goal is to estimate the correction factor E for inferring the temperature variance dissipation ...

Libe Washburn; Timothy F. Duda; David C. Jacobs

1996-12-01T23:59:59.000Z

253

Thermal Gradient Holes At Spencer Hot Springs Area (Shevenell, Et Al.,  

Open Energy Info (EERE)

Hot Springs Area (Shevenell, Et Al., Hot Springs Area (Shevenell, Et Al., 2008) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Spencer Hot Springs Area (Shevenell, Et Al., 2008) Exploration Activity Details Location Spencer Hot Springs Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness useful DOE-funding Unknown Notes Collaboration with the gold mining industry has brought two new geothermal discoveries to the attention of the geothermal community. Exploration holes at Tungsten Mountain and McGuiness Hills (Spencer Hot Springs?) in 2004 and 2005 encountered hot water and steam at depths of meters with fluid geothermometry indicating reservoir temperatures of 170 to 200oC. More information can be obtained from the Nevada Bureau of Mines and Geology web

254

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

Open Energy Info (EERE)

Use of Rapid Temperature Measurements at a 2-Meter Depth to Augment Deeper Use of Rapid Temperature Measurements at a 2-Meter Depth to Augment Deeper Temperature Gradient Drilling Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Use of Rapid Temperature Measurements at a 2-Meter Depth to Augment Deeper Temperature Gradient Drilling Abstract Temperature gradient drilling has historically been a key tool in the exploration for geothermal resources in the Great Basin, USA, but regulatory, environmental, and accessibility issues, as well as the expense of drilling, are increasingly limiting its use. In cases where thermal groundwater is not overlain by near-surface cold aquifers, it is possible to augment temperature gradient drilling with temperatures measured from a 2-meter depth. We discuss the development of a rapid, efficient, and

255

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

Open Energy Info (EERE)

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

256

Spatial and Seasonal Variations of Air Temperature Lapse Rates in Alpine Regions  

Science Conference Proceedings (OSTI)

Air temperature decrease with altitude was estimated by simple linear regression for several regions around northern Italy for minimum, maximum, and mean monthly temperatures. The comparison of the gradients with previous works revealed the ...

Christian Rolland

2003-04-01T23:59:59.000Z

257

Geochemical Aspects of the Carbonation of Magnesium Silicates in an Aqueous Medium  

NLE Websites -- All DOE Office Websites (Extended Search)

GEOCHEMICAL ASPECTS OF THE CARBONATION OF MAGNESIUM GEOCHEMICAL ASPECTS OF THE CARBONATION OF MAGNESIUM SILICATES IN AN AQUEOUS MEDIUM George D. Guthrie, Jr. (gguthrie@lanl.gov 505-665-6340) J. William Carey (bcarey@lanl.gov 505-667-5540) Deborah Bergfeld (debberrg@lanl.gov 505-667-1812) Darrin Byler (dbyler@lanl.gov 505-665-9562) Steve Chipera (chipera@lanl.gov 505-667-1110) Hans-Joachim Ziock (ziock@lanl.gov 505-667-7265) Hydrology, Geochemistry, & Geology Los Alamos National Laboratory Los Alamos, NM 87545 Klaus Lackner (ksl@lanl.gov 505-667-5694) Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM and Columbia University, New York, NY KEYWORDS: CO 2 sequestration, magnesium silicate, mineral carbonation INTRODUCTION The volume of carbon dioxide associated with the use of fossil fuels to produce

258

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

E-Print Network (OSTI)

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 ...

Xu, Guangping

2007-01-01T23:59:59.000Z

259

Force-Gradient Nested Multirate Methods for Hamiltonian System  

E-Print Network (OSTI)

Force-gradient decomposition methods are used to improve the energy preservation of symplectic schemes applied to Hamiltonian systems. If the potential is composed of different parts with strongly varying dynamics, this multirate potential can be exploited by coupling force-gradient decomposition methods with splitting techniques for multi-time scale problems to further increase the accuracy of the scheme and reduce the computational costs. In this paper, we derive novel force-gradient nested methods and test them numerically. Such methods can be used to increase the acceptance rate for the molecular dynamics step of the Hybrid Monte Carlo algorithm (HMC) and hence improve its computational efficiency.

Dmitry Shcherbakov; Matthias Ehrhardt; Michael Günther; Michael Peardon

2013-12-11T23:59:59.000Z

260

Evaluation of selected geochemical anomalies in Colorado and the Southeastern US. Final report  

SciTech Connect

This study demonstrates the utility of HSSR geochemical data from stream sediment in exploration for uranium. In the southeastern US, four uraniferous occurrences and associated radiometric anomalies were identified in areas where uranium mineralization has not been previously reported. At two localities, assays of about .01% have been obtained from saprolite. There is some evidence which suggests that uranium may have been leached at these localities and that higher grades of U are likely at depth.

Carpenter, R H

1980-08-01T23:59:59.000Z

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


261

Proceedings of the second workshop on hydrologic and geochemical monitoring in the Long Valley Caldera  

DOE Green Energy (OSTI)

A workshop was held to review the results of hydrologic and geochemical monitoring and scientific drilling in the Long Valley caldera. Such monitoring is being done to detect changes in the hydrothermal system induced by ongoing magmatic and techonic processes. Data from a 2400-ft deep core hole completed in June 1986 were presented at the 1986 workshop and participants discussed the need and rationale for siting locations for future scientific drilling in the caldera.

Sorey, M.L.; Farrar, C.D.; Wollenberg, H.A. (eds.)

1986-12-01T23:59:59.000Z

262

Forced Disturbances in a Zero Absolute Vorticity Gradient Environment  

Science Conference Proceedings (OSTI)

Observations show the presence of localized regions in the atmosphere with diminished potential vorticity gradients, an example being the tropical upper troposphere where convective heating plays an important role. The present work investigates ...

Paul F. Choboter; Gilbert Brunet; Sherwin A. Maslowe

2000-05-01T23:59:59.000Z

263

High Thermal Gradient Directional Solidification and Its Application ...  

Science Conference Proceedings (OSTI)

By using zone-intensified overheating and liquid-metal cooling, high thermal gradients of up to 800 K/cm were achieved. Application of these methods in the ...

264

On the Computation of Gradients from Observations over Complex Terrain  

Science Conference Proceedings (OSTI)

A mathematical scheme is developed to compute the gradients of observations taken over complex terrain. The method is applied to an artificial example to demonstrate the scheme. An application is made to surface pressure observations between ...

Fred J. Kopp; Paul L. Smith; Harold D. Orville

2001-10-01T23:59:59.000Z

265

A New Horizontal Gradient, Continuous Flow, Ice Thermal Diffusion Chamber  

Science Conference Proceedings (OSTI)

A continuous-flow, horizontal gradient, ice thermal diffusion chamber has been developed and tested for heterogeneous ice nucleation of aerosol particles under accurately controlled supersaturations and supercooling in the absence of a substrate. ...

E. M. Tomlinson; N. Fukuta

1985-12-01T23:59:59.000Z

266

Arizona Cool Season Surface Wind and Pressure Gradient Study  

Science Conference Proceedings (OSTI)

The average sea-level pressure gradients that produce sustained surface winds above 8 kt for at least six consecutive hours during the cool season at predetermined key stations in or adjacent to Arizona are investigated. Only wind directions ...

Ira S. Brenner

1980-02-01T23:59:59.000Z

267

On Computing the Surface Horizontal Pressure Gradient over Elevated Terrain  

Science Conference Proceedings (OSTI)

Methods are proposed for calculating the surface horizontal pressure gradient or geostrophic wind in a local area over elevated terrain from randomly spaced surface observations. These procedures avoid many of the problems associated with sea-...

Maurice Danard

1989-06-01T23:59:59.000Z

268

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

E-Print Network (OSTI)

Sep 28, 2011 ... fukushima-nct.ac.jp) H Yabe(yabe ***at*** rs.kagu.tus.ac.jp). Abstract: Conjugate gradient methods have been paid attention to, because they ...

269

Steady Coastal Circulation Due to Oceanic Alongshore Pressure Gradients  

Science Conference Proceedings (OSTI)

A depth-averaged barotropic model is used to investigate the steady response of the coastal ocean to alongshore pressure gradients imposed by the deep ocean. Solution indicate that the dimensionless continental margin width ? is the appropriate ...

Jason H. Middleton

1987-05-01T23:59:59.000Z

270

Asymmetric Tidal Mixing due to the Horizontal Density Gradient  

Science Conference Proceedings (OSTI)

Stratification and turbulent mixing exhibit a flood–ebb tidal asymmetry in estuaries and continental shelf regions affected by horizontal density gradients. The authors use a large-eddy simulation (LES) model to investigate the penetration of a ...

Ming Li; John Trowbridge; Rocky Geyer

2008-02-01T23:59:59.000Z

271

Time delay learning by gradient descent in recurrent neural networks  

Science Conference Proceedings (OSTI)

Recurrent Neural Networks (RNNs) possess an implicit internal memory and are well adapted for time series forecasting. Unfortunately, the gradient descent algorithms which are commonly used for their training have two main weaknesses: the slowness and ...

Romuald Boné; Hubert Cardot

2005-09-01T23:59:59.000Z

272

Thermal Gradient Holes At Central Nevada Seismic Zone Region (Pritchett,  

Open Energy Info (EERE)

Thermal Gradient Holes At Central Nevada Seismic Zone Region (Pritchett, Thermal Gradient Holes At Central Nevada Seismic Zone Region (Pritchett, 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Central Nevada Seismic Zone Region (Pritchett, 2004) Exploration Activity Details Location Central Nevada Seismic Zone Geothermal Region Exploration Technique Thermal Gradient Holes Activity Date Usefulness useful DOE-funding Unknown Notes NOTE: These are theoretical/computer simulation tests of various methods on eight hypothetical 'model' basing-and-range geothermal systems. "The 300-meter heat flow holes are essentially useless for finding the "hidden" reservoirs. Clearly, the best results are obtained from the SP and MT surveys, with DC resistivity a close third. It is concluded that the best

273

GEOTECHNICAL/GEOCHEMICAL CHARACTERIZATION OF ADVANCED COAL PROCESS WASTE STREAMS  

Science Conference Proceedings (OSTI)

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.

Edwin S. Olson; Charles J. Moretti

1999-11-01T23:59:59.000Z

274

Evaluation of liquid lift approach to dual gradient drilling  

E-Print Network (OSTI)

In the past, the oil and gas industry has typically used the single gradient system to drill wells offshore. With this system the bottom hole pressure was controlled by a mud column extending from the drilling rig to the bottom of the wellbore. This mud column was used to achieve the required bottom hole pressure. But, as the demand for oil and gas increased, the industry started exploring for oil and gas in deep waters. Because of the narrow margin between the pore and fracture pressures it is somewhat difficult to reach total depth with the single gradient system. This led to the invention of the dual gradient system. In the dual gradient method, heavy density fluid runs from the bottom hole to the mudline and a low density fluid from the mudline to the rig floor so as to maintain the bottom hole pressure. Several methods have been developed to achieve the dual gradient drilling principle. For this research project, we paid more attention to the liquid lift, dual gradient drilling (riser dilution method). This method of achieving dual gradient drilling was somewhat different from the others, because it does not utilize elaborate equipment and no major changes are made on the existing drilling rigs. In this thesis the technical feasibility of using the liquid lift method over the other methods of achieving dual gradient drilling was determined. A computer program was developed to simulate the wellbore hydraulics under static and dynamic conditions, injection rate and base fluid density required to dilute the riser fluid and finally, u-tubing phenomena. In this thesis we also identified some problems associated with the liquid lift method and recommendations were made on how these problems can be eliminated or reduced. Emphases were placed on the effect of u-tubing, injection rate of base fluid at the bottom of the riser and well control issues facing this system.

Okafor, Ugochukwu Nnamdi

2007-12-01T23:59:59.000Z

275

Evaluation of liquid lift approach to dual gradient  

E-Print Network (OSTI)

In the past, the oil and gas industry has typically used the single gradient system to drill wells offshore. With this system the bottom hole pressure was controlled by a mud column extending from the drilling rig to the bottom of the wellbore. This mud column was used to achieve the required bottom hole pressure. But, as the demand for oil and gas increased, the industry started exploring for oil and gas in deep waters. Because of the narrow margin between the pore and fracture pressures it is somewhat difficult to reach total depth with the single gradient system. This led to the invention of the dual gradient system. In the dual gradient method, heavy density fluid runs from the bottom hole to the mudline and a low density fluid from the mudline to the rig floor so as to maintain the bottom hole pressure. Several methods have been developed to achieve the dual gradient drilling principle. For this research project, we paid more attention to the liquid lift, dual gradient drilling (riser dilution method). This method of achieving dual gradient drilling was somewhat different from the others, because it does not utilize elaborate equipment and no major changes are made on the existing drilling rigs. In this thesis the technical feasibility of using the liquid lift method over the other methods of achieving dual gradient drilling was determined. A computer program was developed to simulate the wellbore hydraulics under static and dynamic conditions, injection rate and base fluid density required to dilute the riser fluid and finally, u-tubing phenomena. In this thesis we also identified some problems associated with the liquid lift method and recommendations were made on how these problems can be eliminated or reduced. Emphases were placed on the effect of u-tubing, injection rate of base fluid at the bottom of the riser and well control issues facing this system.

Okafor, Ugochukwu Nnamdi

2007-12-01T23:59:59.000Z

276

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

Science Conference Proceedings (OSTI)

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.

Kaplan, D

2006-02-28T23:59:59.000Z

277

Permafrost and organic layer interactions over a climate gradient in a discontinuous permafrost zone  

Science Conference Proceedings (OSTI)

Permafrost is tightly coupled to the organic layer, an interaction that mediates permafrost degradation in response to regional warming. We analyzed changes in permafrost occurrence (PF) and organic layer thickness (OLT) in more than 3000 soil pedons across a mean annual temperature (MAT) gradient. Cause and effect relationships between PF, OLT, and other topographic factors were investigated using structural equation modeling in a multi-group analysis. Groups were defined by slope, soil texture type, and shallow v. deep organic layers. Permafrost probability sharply increased by 0.32 for every 10-cm OLT increase in shallow OLT soils (OLTs) due to an insulation effect, but PF decreased in deep OLT soils (OLTd) by 0.06 for every 10-cm increase. As temperature warmed, sandy soils varied little in PF or OLT, but PF in loamy and sandy soils decreased substantially. The change in OLT was more heterogeneous across soil types in some there was no change while in others OLTs soils thinned and/or OLTd soils thickened as temperature warmed. Furthermore, the rate of thickening with warming for OLTd soils was on average almost 4 times greater than the rate of thinning for OLTs soils across all soil types. If soils follow a trajectory of warming that mimics the spatial gradients found today, then heterogeneities of permafrost degradation and organic layer thinning and thickening should be considered in the regional carbon balance.

Johnson, Kristopher D [University of Alaska, Fairbanks; Harden, Jennifer [United States Geological Service (USGS), Menlo Park; McGuire, A. David [University of Alaska; Clark, Mark [United Stated Department of Agriculture (USDA), Natural Resources Conservation Service; Yuan, Fengming [ORNL; Finley, Andrew [Michigan State University, East Lansing

2013-01-01T23:59:59.000Z

278

Geothermal Gradients in Oregon, 1985-1994  

DOE Green Energy (OSTI)

This data set is comprised of three groups of temperature-depth data. All the sites are located in southeastern Oregon. The first is a set of 7 wells logged during 1993 in south central Oregon in the Basin and Range province. All these wells, with the exception of the Blue Mountain Oil well, are water wells. These wells were part of a geothermal reconnaissance of this area. The Blue Mountain oil well of this set has been described by Sass et al. (1971) as well. Gannet in the vicinity of the Vale, Oregon (Bowen and Blackwell, 1972; Blackwell et al., 1978) geothermal system in Malheur County. These wells were logged in 1986 during a study of the area described by Gannett (1988). There are 17 wells (plus one relog) in this data set. All these wells are in a small area just east of the town of Vale in Malheur County. The second set of data consists of a group of wells that were logged by Marshall The third set of data represents the results of an exploration project in the general area of the Lake Owyhee thermal area in Malheur County. This data set is comprised of 16 wells. This data set was collected by Hunt Energy Corporation and made available though the efforts of Roger Bowers. A small scale map of the locations of the wells is shown in Figure 1. The well location and some pertinent information about the wells is shown in Table 1. The detailed lists of temperature-depth data and plots for each well, either individually or with a group, follow the list of references cited.

Blackwell, D.D.

1995-01-01T23:59:59.000Z

279

Data for the geochemical investigation of UMTRAP designated site at Ambrosia Lake, New Mexico  

SciTech Connect

This report contains the geochemical data and the methods of data collection from the former tailings site at Ambrosia Lake, New Mexico. Data are from a one-time sampling of waters and solid material from the background, the area adjacent to the site, and the site. Selected solid samples are water extracted to remove easily soluble salts and acid extracted to remove carbonates and hydroxides. The waters, extracts, and solid samples were analyzed for selected major and trace elements. 3 refs., 2 figs., 1 tab.

Markos, G.; Bush, K.J.

1983-09-01T23:59:59.000Z

280

Pumpernickel Valley Geothermal Project Thermal Gradient Wells | Open Energy  

Open Energy Info (EERE)

Valley Geothermal Project Thermal Gradient Wells Valley Geothermal Project Thermal Gradient Wells Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Pumpernickel Valley Geothermal Project Thermal Gradient Wells Details Activities (4) Areas (1) Regions (0) Abstract: 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,

Note: This page contains sample records for the topic "temperature gradient geochemical" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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281

Experimental and theoretical investigation of high gradient acceleration  

Science Conference Proceedings (OSTI)

This report contains a technical progress summary of the research conducted under the auspices of DOE Grant No. DE-FG0291ER-40648. Experimental and Theoretical Investigations of High Gradient Acceleration.'' This grant supports three research tasks: Task A consists of the design and fabrication of a 17GHz of photocathode gun, Task B supports the testing of high gradient acceleration using a 33GHz structure, and Task C comprises theoretical investigations, both in support of the experimental tasks and on critical physics issues for the development of high energy linear colliders. This report is organized as follows. The development of an rf gun design and research progress on the picosecond laser system is summarized in Sec. 2, the status of the studies of the LBL/Haimson high gradient structure, using a 50 MW free-electron laser is summarized in Sec. 3, and theoretical research progress is described in Sec. 4. Supporting material is contained in Appendices A-G.

Bekefi, G.; Chen, C.; Chen, S.; Danly, B.; Temkin, R.J.; Wurtele, J.S.

1992-02-01T23:59:59.000Z

282

Universal estimate of the gradient for parabolic equations  

E-Print Network (OSTI)

We suggest a modification of the estimate for weighted Sobolev norms of solutions of parabolic equations such that the matrix of the higher order coefficients is included into the weight for the gradient. More precisely, we found the upper limit estimate that can be achieved by variations of the zero order coefficient. As an example of applications, an asymptotic estimate was obtained for the gradient at initial time. The constant in the estimates is the same for all possible choices of the dimension, domain, time horizon, and the coefficients of the parabolic equation. As an another example of application, existence and regularity results are obtained for parabolic equations with time delay for the gradient.

Nikolai Dokuchaev

2007-09-06T23:59:59.000Z

283

Simulation of a Microfluidic Gradient Generator using Lattice Boltzmann Methods  

E-Print Network (OSTI)

Microfluidics provides a powerful and versatile technology to accurately control spatial and temporal conditions for cell culturing and can therefore be used to study cellular responses to gradients. Here we use Lattice Boltzmann methods (LBM) to solve both the Navier-Stokes equation (NSE) for the fluid and the coupled convection-diffusion equation (CDE) for the compounds that form the diffusion-based gradient. The design of a microfluidic chamber for diffusion-based gradients must avoid flow through the cell chamber. This can be achieved by alternately opening the source and the sink channels. The fast toggling of microfluidic valves requires switching between different boundary conditions. We demonstrate that the LBM is a powerful method for handling complex geometries, high Peclet number conditions, discontinuities in the boundary conditions, and multiphysics coupling.

Simon, Tanaka

2013-01-01T23:59:59.000Z

284

Thermal Gradient Holes At Chena Area (Erkan, Et. Al., 2008) | Open Energy  

Open Energy Info (EERE)

Chena Area (Erkan, Et. Al., Chena Area (Erkan, Et. Al., 2008) Exploration Activity Details Location Chena Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness useful DOE-funding Unknown Notes MULTI-STAGE DRILLING Once a hole is drilled the natural-state pressure distribution with depth is essentially unrecoverable (Grant et al., 1982). One of the best ways to mitigate this effect is to use multi-stage drilling (White et al., 1975; Grant et al., 1982). This type of drilling was applied at Chena and its usefulness in understanding the natural flow regimes is demonstrated. Here, we illustrate how high-quality equilibrium temperature logs can often be used to identify permeable fractures. The independent interpretations of flow regimes based on temperature-depth curves and the

285

Low Speed Nano/Micro/Meso-Scale Rarefied Flows Driven by Temperature and Pressure Gradients  

E-Print Network (OSTI)

no moving parts and is driven by thermal creep flow, which in one version is generated by applying/meso-scale solid state compressor or vacuum pump, now relatively well known as the Knudsen Compressor. It has-equilibrium because of rarefaction effects. Consequently the constitutive relations for the stress tensor and the heat

Alexeenko, Alina

286

Mathematical Modeling and Simulation of Denaturation Temperature Gradient Polymerase Chain Reaction  

E-Print Network (OSTI)

Ji Youn Lee, Hee-Woong Lim , Suk-In Yoo , Byoung-Tak Zhang and Tai Hyun Park School of Chemical amplification of nucleic acids, which is applicable to versatile biochemical applications. PCR plays is formulated with kinetic constants of hybridization reactions while the extension step is formulated

Yoo, SukIn

287

ESTIMATION OF IN-SITU THERMAL CONDUCTIVITIES FROM TEMPERATURE GRADIENT MEASUREMENTS  

E-Print Network (OSTI)

where: pc v • phonon heat capacity, c• phonon velocity,fluid density, the specific heat capacity of the fluid. Thean l8cm Values of heat capacities diameter casing for three

Hoang, V.T.

2010-01-01T23:59:59.000Z

288

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

E-Print Network (OSTI)

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

289

ESTIMATION OF IN-SITU THERMAL CONDUCTIVITIES FROM TEMPERATURE GRADIENT MEASUREMENTS  

E-Print Network (OSTI)

in a Cir- culating Drilling Fluid," Journal of Petroleumtemperature after drilling, or injecting fluid. Bullard [14

Hoang, V.T.

2010-01-01T23:59:59.000Z

290

Objective Satellite-Based Detection of Overshooting Tops Using Infrared Window Channel Brightness Temperature Gradients  

Science Conference Proceedings (OSTI)

Deep convective storms with overshooting tops (OTs) are capable of producing hazardous weather conditions such as aviation turbulence, frequent lightning, heavy rainfall, large hail, damaging wind, and tornadoes. This paper presents a new ...

Kristopher Bedka; Jason Brunner; Richard Dworak; Wayne Feltz; Jason Otkin; Thomas Greenwald

2010-02-01T23:59:59.000Z

291

A Numerical Model Study of Nocturnal Drainage Flows with Strong Wind and Temperature Gradients  

Science Conference Proceedings (OSTI)

A second-moment turbulence-closure model described in Yamada and Bunker is used to simulate nocturnal drainage flows observed during the 1984 ASCOT field expedition in Brush Creek, Colorado. In order to simulate the observed strong wind ...

T. Yamada; S. Bunker

1989-07-01T23:59:59.000Z

292

Modeling of grain growth in UO2 under a temperature gradient  

Science Conference Proceedings (OSTI)

Characterization of MOX fuel pellets by Photothermal microscopy · Correlation Between Thermal Conductivity and Microstructural Evolutions in CeO2 Upon ...

293

ESTIMATION OF IN-SITU THERMAL CONDUCTIVITIES FROM TEMPERATURE GRADIENT MEASUREMENTS  

E-Print Network (OSTI)

By analyzing the heat transfer process inside the tubing andnatural convection heat transfer process, three equationsis the dominant heat transfer process during shut-in, the

Hoang, V.T.

2010-01-01T23:59:59.000Z

294

The impact of Summer Rainfall on the Temperature Gradient along the United States-Mexico Border  

Science Conference Proceedings (OSTI)

The international border running through the Sonoran Desert in southern Arizona and northern Sonora is marked by a sharp discontinuity in albedo and grass cover. The observed differences in surface properties are a result of long-term, severe ...

Robert C. Balling Jr.

1989-04-01T23:59:59.000Z

295

Gradient isolator for flow field of fuel cell assembly  

DOE Patents (OSTI)

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

Ernst, W.D.

1999-06-15T23:59:59.000Z

296

Speed-gradient principle for nonstationary processes in thermodynamics  

E-Print Network (OSTI)

The speed-gradient variational principle (SG-principle) is formulated and applied to thermodynamical systems. It is shown that Prigogine's principle of minimum entropy production and Onsager's symmetry relations can be interpreted in terms of the SG-principle and, therefore, are equivalent to each other. In both cases entropy of the system plays a role of the goal functional. The speed-gradient formulation of thermodynamic principles provide their extended versions, describing transient dynamics of nonstationary systems far from equilibrium. As an example a model of transient (relaxation) dynamics for maximum entropy principle is derived.

Alexander L. Fradkov

2007-01-28T23:59:59.000Z

297

Salt concentration gradient solar ponds: modeling and optimization  

DOE Green Energy (OSTI)

A computer simulation design tool has been developed to simulate dynamic thermal performance for salinity gradient solar ponds. This program will be available to the public through the SERI Solar Analysis Methods Center. Dynamic programming techniques are applied to allow significant user 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 are presented that 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.

Jayadev, T. S.; Henderson, J.

1979-01-01T23:59:59.000Z

298

A simplified implementation of a gradient-enhanced damage model with transient length scale effects  

Science Conference Proceedings (OSTI)

Gradient-enhanced damage models with constant gradient activity suffer from spurious damage growth at high deformation levels. This issue was resolved by Geers et al. (Comput Methods Appl Mech Eng 160(1---2):133---153, 1998) by expressing the gradient ... Keywords: Continuum damage mechanics, Gradient-enhanced damage models, Regularized media, Transient internal length scale

S. Saroukhani; R. Vafadari; A. Simone

2013-06-01T23:59:59.000Z

299

Radiance Temperature  

Science Conference Proceedings (OSTI)

... Temperature using Detectors Calibrated for Absolute Spectral Power Response, HW ... A Third Generation Water Bath Based Blackbody Source, JB ...

2013-06-27T23:59:59.000Z

300

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

SciTech Connect

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.

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

2012-07-09T23:59:59.000Z

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


301

Trace metal speciation in saline waters affected by geothermal brines. Final technical report. [GEOCHEM  

DOE Green Energy (OSTI)

The computer program GEOCHEM was developed and applied to calculate the speciation of trace elements, such as Li, B, Mn, Co, Ni, Cu, Zn, Pb, and As, in mixtures of geothermal brines with soil waters. A typical speciation calculation involved the simultaneous consideration of about 350 inorganic and organic complexes and about 80 possible solid phases that could form among the macro- and microconstituents in the mixtures. The four geothermal brines chosen for study were from the East Mesa, Heber, and Salton Sea KGRA's. Two examples of East Mesa brine were employed in order to illustrate the effect of brine variability within a given KGRA. The soil waters chosen for study were the Holtville, Rosita, and Vint soil solutions and the Vail 4 drain water. These waters were mixed with the four brines to produce 1%, 5%, and 10% brine combinations. The combinations then were analyzed with the help of GEOCHEM and were interpreted in the context of two proposed general contamination scenarios. The results of the speciation calculations pointed to the great importance, in brine, of sulfide as a precipitating agent for trace metals and of borate as a trace metal-complexing ligand. In general, precipitation and/or exchange adsorption in soil were found to reduce the levels of trace metals well below harmful concentrations. The principal exceptions were Li and B, which did not precipitate and which were at or very hear harmful levels in the soil water-brine mixtures.

Sposito, G.

1979-07-01T23:59:59.000Z

302

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

Science Conference Proceedings (OSTI)

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.

Lindquist, W Brent

2009-03-03T23:59:59.000Z

303

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

DOE Green Energy (OSTI)

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.

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

1995-01-01T23:59:59.000Z

304

Scaling limits for gradient systems in random environment  

E-Print Network (OSTI)

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

P. Goncalves; M. D. Jara

2007-02-17T23:59:59.000Z

305

Parallel Stochastic Gradient Algorithms for Large-Scale Matrix ...  

E-Print Network (OSTI)

the decision variable and use incremental gradient methods that operate upon ... P : Rnr×nc ? R will be a matrix regularizer which will control some measure of complexity ...... indicating longer epochs (although the operating system reports 24 processors). .... The power of convex relaxation: Near-optimal matrix completion.

306

Learning to search: Functional gradient techniques for imitation learning  

Science Conference Proceedings (OSTI)

Programming robot behavior remains a challenging task. While it is often easy to abstractly define or even demonstrate a desired behavior, designing a controller that embodies the same behavior is difficult, time consuming, and ultimately expensive. ... Keywords: Autonomous navigation, Functional gradient techniques, Grasping, Imitation learning, Nonparametric optimization, Planning, Quadrupedal locomotion, Robotics, Structured prediction, Subgradient methods

Nathan D. Ratliff; David Silver; J. Andrew Bagnell

2009-07-01T23:59:59.000Z

307

On the Pressure Gradient Force Error in ?-Coordinate Spectral Models  

Science Conference Proceedings (OSTI)

The pressure gradient force error of the spectral technique used in combination with the ? vertical coordinate was examined in an idealized case of an atmosphere at rest and in hydrostatic equilibrium. Small-scale (one-point and three-point) ...

Zavis?a I. Janji?

1989-10-01T23:59:59.000Z

308

An accelerated proximal gradient algorithm for nuclear norm ...  

E-Print Network (OSTI)

Mar 27, 2009 ... algorithm that does not require more than one gradient evaluation at each .... semidefinite program as follows; see [38] for details: .... The expected number svk is set by the following procedure. ...... 12 (1981), 989–1000. ... estimation in multivariate linear regression, Journal of the Royal Statistical Society:.

309

Forest soil carbon inventories and dynamics along an elevation gradient in the southern Appalachian Mountains  

Science Conference Proceedings (OSTI)

Soil organic carbon (SOC) was partitioned between unprotected and protected pools in six forests along an elevation gradient in the southern Appalachian Mountains using two physical methods: flotation in aqueous CaCl{sub 2} (1.4 g/mL) and wet sieving through a 0.053 mm sieve. Both methods produced results that were qualitatively and quantitatively similar. Along the elevation gradient, 28 to 53% of the SOC was associated with an unprotected pool that included forest floor O-layers and other labile soil organic matter (SOM) in various stages of decomposition. Most (71 to 83%) of the C in the mineral soil at the six forest sites was identified as protected because of its association with a heavy soil fraction (> 1.4 g/mL) or a silt-clay soil fraction. Total inventories of SOC in the forests (to a depth of 30 cm) ranged from 384 to 1244 mg C/cm{sup 2}. The turnover time of the unprotected SOC was negatively correlated (r = -0.95, p < 0.05) with mean annual air temperature (MAT) across the elevation gradient. Measured SOC inventories, annual C returns to the forest floor, and estimates of C turnover associated with the protected soil pool were used to parameterize a simple model of SOC dynamics. Steady-state predictions with the model indicated that, with no change in C inputs, the low- (235-335 m), mid- (940-1000 m), and high- (1650-1670 m) elevation forests under study might surrender {approx} 40 to 45% of their current SOC inventory following a 4 C increase in MAT. Substantial losses of unprotected SOM as a result of a warmer climate could have long-term impacts on hydrology, soil quality, and plant nutrition in forest ecosystems throughout the southern Appalachian Mountains.

Garten Jr, Charles T [ORNL; Post, Wilfred M [ORNL; Hanson, Paul J [ORNL; Cooper, Lee W [ORNL

1999-05-01T23:59:59.000Z

310

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

DOE Green Energy (OSTI)

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)

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

311

Geochemical records in the South China Sea: implications for East Asian summer monsoon evolution over the last 20 Ma  

E-Print Network (OSTI)

Geochemical records in the South China Sea: implications for East Asian summer monsoon evolution past changes in the East Asian summer monsoon over the last 20 Ma using samples from Ocean Drilling and combined review suggests that the long-term evolution of the East Asian summer monsoon is similar

Clift, Peter

312

Geochemical Data on Waters, gases, scales, and rocks from the Dixie Valley Region, Nevada (1996-1999)  

DOE Green Energy (OSTI)

This report tabulates an extensive geochemical database on waters, gases, scales, rocks, and hot-spring deposits from the Dixie Valley region, Nevada. The samples from which the data were obtained were collected and analyzed during 1996 to 1999. These data provide useful information for ongoing and future investigations on geothermal energy, volcanism, ore deposits, environmental issues, and groundwater quality in this region.

Goff, Fraser; Bergfeld, Deborah; Janik, C.J.; et al

2002-08-01T23:59:59.000Z

313

VOLTINT: A Matlab®-based program for semi-automated processing of geochemical data acquired by voltammetry  

Science Conference Proceedings (OSTI)

Recent progress has resulted in the development of advanced techniques to acquire geochemical information in situ in aquatic systems. Among these techniques, voltammetry has generated significant interest for its ability to detect several important redox-sensitive ... Keywords: Data processing, Geochemistry, Integration, Matlab®, Software, Voltammetry

Gwendolyn Bristow; Martial Taillefert

2008-02-01T23:59:59.000Z

314

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

Science Conference Proceedings (OSTI)

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)

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

1996-05-01T23:59:59.000Z

315

Hydrogeochemical and stream sediment detailed geochemical survey for Edgemont, South Dakota; Wyoming  

SciTech Connect

Results of the Edgemont detailed geochemical survey are reported. Field and laboratory data are presented for 109 groundwater and 419 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are given. A generalized geologic map of the survey area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. Groundwaters containing greater than or equal to 7.35 ppB uranium are present in scattered clusters throughout the area sampled. Most of these groundwaters are from wells drilled where the Inyan Kara Group is exposed at the surface. The exceptions are a group of samples in the northwestern part of the area sampled and south of the Dewey Terrace. These groundwaters are also produced from the Inyan Kara Group where it is overlain by the Graneros Group and alluvium. The high uranium groundwaters along and to the south of the terrace are characterized by high molybdenum, uranium/specific conductance, and uranium/sulfate values. Many of the groundwaters sampled along the outcrop of the Inyan Kara Group are near uranium mines. Groundwaters have high amounts of uranium and molybdenum. Samples taken downdip are sulfide waters with low values of uranium and high values of arsenic, molybdenum, selenium, and vanadium. Stream sediments containing greater than or equal to 5.50 ppM soluble uranium are concentrated in basins draining the Graneros and Inyan Kara Groups. These values are associated with high values for arsenic, selenium, and vanadium in samples from both groups. Anomalous values for these elements in the Graneros Group may be caused by bentonite beds contained in the rock units. As shown on the geochemical distribution plot, high uranium values that are located in the Inyan Kara Group are almost exclusively draining open-pit uranium mines.

Butz, T.R.; Dean, N.E.; Bard, C.S.; Helgerson, R.N.; Grimes, J.G.; Pritz, P.M.

1980-05-31T23:59:59.000Z

316

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

Science Conference Proceedings (OSTI)

Several activities related to geothermal resources in the western United States are described in this report. A database of geothermal site-specific thermal gradient and heat flow results from individual exploration wells in the western US has been assembled. Extensive temperature gradient and heat flow exploration data from the active exploration of the 1970's and 1980's were collected, compiled, and synthesized, emphasizing previously unavailable company data. Examples of the use and applications of the database are described. The database and results are available on the world wide web. In this report numerical models are used to establish basic qualitative relationships between structure, heat input, and permeability distribution, and the resulting geothermal system. A series of steady state, two-dimensional numerical models evaluate the effect of permeability and structural variations on an idealized, generic Basin and Range geothermal system and the results are described.

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

2000-04-01T23:59:59.000Z

317

Development of 2-Meter Soil Temperature Probes and Results of Temperature  

Open Energy Info (EERE)

Development of 2-Meter Soil Temperature Probes and Results of Temperature Development of 2-Meter Soil Temperature Probes and Results of Temperature Survey Conducted at Desert Peak, Nevada, USA Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Development of 2-Meter Soil Temperature Probes and Results of Temperature Survey Conducted at Desert Peak, Nevada, USA Abstract Temperature gradient drilling has historically been a key tool in the exploration for geothermal resources in the Great Basin, USA but regulatory, environmental, and accessibility issues, as well as the expense of drilling, are increasingly limiting its use. In cases where thermal groundwater is not overlain by near-surface cold aquifers, temperatures measured at a depth of 2-meters is an efficient method for mapping thermal anomalies at a high level of detail. This is useful for augmenting deeper

318

Chiral symmetry and the Yang--Mills gradient flow  

E-Print Network (OSTI)

In the last few years, the Yang--Mills gradient flow was shown to be an attractive tool for non-perturbative studies of non-Abelian gauge theories. Here a simple extension of the flow to the quark fields in QCD is considered. As in the case of the pure-gauge gradient flow, the renormalizability of correlation functions involving local fields at positive flow times can be established using a representation through a local field theory in 4+1 dimensions. Applications of the extended flow in lattice QCD include non-perturbative renormalization and O(a) improvement as well as accurate calculations of the chiral condensate and of the pseudo-scalar decay constant in the chiral limit.

Martin Lüscher

2013-02-21T23:59:59.000Z

319

Elastic Relaxation and Correlation of Local Strain Gradients with  

NLE Websites -- All DOE Office Websites (Extended Search)

Elastic Relaxation and Correlation Elastic Relaxation and Correlation of Local Strain Gradients with Ferroelectric Domains in (001) BiFeO3 Nanostructures Elastic Relaxation and Correlation of Local Strain Gradients with Ferroelectric Domains in (001) BiFeO3 Nanostructures Researchers at Argonne National Laboratory (MSD and CNM) have recently performed first worldwide studies of effects of nanopatterning on fundamental phenomena in mutiferroic BiFeO3 (BFO) nanostructures, using the APS-CNM nanoprobe beam (50 nm diameter). Nano-focused x-ray diffraction microscopy provided new insights into the relationship between film strain and ferroelectric domains in nanostructures, namely: i) an out-of-plane strain enhancement of as much as -1.8% Δc/c in a BFO film-based nanostructure relative to a planar film; ii) out-of-plane BFO C-axis

320

Gradient type optimization methods for electronic structure calculations  

E-Print Network (OSTI)

The density functional theory (DFT) in electronic structure calculations can be formulated as either a nonlinear eigenvalue or direct minimization problem. The most widely used approach for solving the former is the so-called self-consistent field (SCF) iteration. A common observation is that the convergence of SCF is not clear theoretically while approaches with convergence guarantee for solving the latter are often not competitive to SCF numerically. In this paper, we study gradient type methods for solving the direct minimization problem by constructing new iterations along the gradient on the Stiefel manifold. Global convergence (i.e., convergence to a stationary point from any initial solution) as well as local convergence rate follows from the standard theory for optimization on manifold directly. A major computational advantage is that the computation of linear eigenvalue problems is no longer needed. The main costs of our approaches arise from the assembling of the total energy functional and its grad...

Zhang, Xin; Wen, Zaiwen; Zhou, Aihui

2013-01-01T23:59:59.000Z

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


321

Plasma wave propagation with a plasma density gradient  

Science Conference Proceedings (OSTI)

Plasma waves with the plasma diffusion velocity u{sub n} due to a plasma density gradient are described in a positive column plasma. The ion wave is generated by the perturbation of the operating frequency 10{sup 6} s{sup -1} and it propagates with the group velocity u{sub g{approx}}c{sub s}{sup 2}/u{sub n{approx}}(10{sup 5}-10{sup 6}) m/s, where c{sub s} is the acoustic velocity in a fine tube fluorescent lamp, while the electron wave cannot be generated with a turbulence of low frequency less than the electron oscillation frequency {omega}{sub pe}. The propagation of the lighting signal observed in long tube fluorescent lamps is well understood with the propagation of ion waves occurring along the plasma density gradient.

Cho, Guangsup; Choi, Eun-Ha; Uhm, Han Sup [Department of Electrophysics, Kwangwoon University, 447-1 Nowon Wallgye, Seoul 139-701 (Korea, Republic of)

2011-03-15T23:59:59.000Z

322

Fabrication process for a gradient index x-ray lens  

DOE Patents (OSTI)

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

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

1995-01-01T23:59:59.000Z

323

Fabrication process for a gradient index x-ray lens  

DOE Patents (OSTI)

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.

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

1995-01-17T23:59:59.000Z

324

Gradient instabilities of electromagnetic waves in Hall thruster plasma  

SciTech Connect

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

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

2013-04-15T23:59:59.000Z

325

MEASURING LOCAL GRADIENT AND SKEW QUADRUPOLE ERRORS IN RHIC IRS.  

SciTech Connect

The measurement of local linear errors at RHIC interaction regions using an ''action and phase'' analysis of difference orbits has already been presented. This paper evaluates the accuracy of this technique using difference orbits that were taken when known gradient errors and skew quadrupole errors were intentionally introduced. It also presents action and phase analysis of simulated orbits when controlled errors are intentionally placed in a RHIC simulation model.

CARDONA,J.; PEGGS,S.; PILAT,R.; PTITSYN,V.

2004-07-05T23:59:59.000Z

326

High Gradient Operation with the CEBAF Upgrade RF Control System  

SciTech Connect

The CEBAF Accelerator at Jefferson Lab is presently a 6 GeV five pass electron accelerator consisting of two superconducting linacs joined by independent magnetic transport arcs. Energy will be upgraded to 12 GeV with the addition of 10 new high gradient cryomodules (17+ MV/m). The higher gradients pose significant challenges beyond what the present analog low level RF (LLRF) control systems can handle reliably; therefore, a new LLRF control system is needed. A prototype system has been developed incorporating a large FPGA and using digital down and up conversion to minimize the need for analog components. The new system is more flexible and less susceptible to drifts and component nonlinearities. Because resonance control is critical to reach high gradients quickly, the new cryomodules will include a piezoelectric tuner for each cavity, and the LLRF controls must incorporate both feedback and feed-forward methods to achieve optimal resonance control performance. This paper discusses development of the new RF system, system performance for phase and amplitude stability and resonance control under Lorentz detuning measured during recent tests on a prototype cryomodule.

J. Hovater; G. Davis; Hai Dong; Alicia Hofler; Lawrence King; John Musson; Tomasz Plawski

2006-08-16T23:59:59.000Z

327

Sea Surface Temperature and Wind Stress Curl Variability near a Cape  

Science Conference Proceedings (OSTI)

The coupling between sea surface temperature (SST), SST gradients, and wind stress curl variability near a cape off Brazil is investigated using satellite observations and several different SST high-resolution analyses. The cape is characterized ...

Renato M. Castelao

2012-11-01T23:59:59.000Z

328

Electric fields in solar magnetic structures due to gradient driven instabilities: heating and acceleration of particles  

E-Print Network (OSTI)

The electrostatic instabilities driven by the gradients of the density, temperature and magnetic field, are discussed in their application to solar magnetic structures. Strongly growing modes are found for some typical plasma parameters. These instabilities i) imply the presence of electric fields that can accelerate the plasma particles in both perpendicular and parallel directions with respect to the magnetic field vector, and ii) can stochastically heat ions. The perpendicular acceleration is to the leading order determined by the $\\bmath{E}\\times \\bmath{B}$-drift acting equally on both ions and electrons, while the parallel acceleration is most effective on electrons. The experimentally confirmed stochastic heating is shown to act mainly in the direction perpendicular to the magnetic field vector and acts stronger on heavier ions. The energy release rate and heating may exceed for several orders of magnitude the value accepted as necessary for a self-sustained heating in the solar corona. The energy sourc...

Vranjes, J

2009-01-01T23:59:59.000Z

329

Thermal Gradient Holes At Cove Fort Area - Vapor (Warpinski, Et Al., 2002)  

Open Energy Info (EERE)

2) 2) Exploration Activity Details Location Cove Fort Geothermal Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness not indicated DOE-funding Unknown Notes The project at Cove Fort/Sulphurdale in Utah, T26S R6/7W, is concerned with locating and drilling a 900-meter well to explore the western extension of the Cove Fort-Sulphurdale geothermal area. The geophysical exploration consisted of resistivity, ground magnetic, and microgravity surveys that were made to site the well in an optimum location. Drilling of the test well was completed in the fall of 2001 and results are currently being evaluated. The total depth of the well is 598 m with a non-equilibrated maximum temperature probably in the range of 157degrees C and a very complicated geologic structure.

330

Thermal Gradient Holes At Tungsten Mountain Area (Kratt, Et Al., 2008) |  

Open Energy Info (EERE)

Kratt, Et Al., 2008) Kratt, Et Al., 2008) Exploration Activity Details Location Tungsten Mountain Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness useful DOE-funding Unknown Notes twenty-three gold exploration holes were drilled by Newcrest Resources, Inc. during 2005 and 2006 along the range front. These holes approached or exceeded 300 m in depth and all holes encountered hot water and/or steam. Despite the high temperatures encountered at relatively shallow depths, there are no active geothermal features such as hot springs or steam vents at the surface. The presence of small outcrops of argillic alteration containing anomalous gold attracted the interest of exploration geologists. References Christopher Kratt, Mark Coolbaugh, Chris Sladek, Rick Zehner, Robin

331

Two-Gradient Convection in a Vertical Slot with Maxwell-Cattaneo Heat Conduction  

SciTech Connect

We study the effect of the Maxwell-Cattaneo law of heat conduction (MCHC) on the 1D flow in a vertical slot subject to both vertical and horizontal temperature gradients. The gravitational acceleration is allowed to oscillate, which provides an opportunity to investigate the quantitative contribution of thermal inertia as epitomized by MCHC. The addition of the time derivative in MCHC increases the order of the system. We use a spectral expansion with Rayleigh's beam functions as the basis set, which is especially suited to fourth order boundary value problems (BVP). We show that the time derivative (relaxation of the thermal flux) has a dissipative nature and leads to the appearance of purely real negative eigenvalues. Yet it also increases the absolute value of the imaginary part and decreases the absolute value of the real part of the complex eigenvalues. Thus, the system has a somewhat more oscillatory behavior than the one based on Fourier's heat conduction law (FHC)

Papanicolaou, N. C. [Department of Computer Science, University of Nicosia, P.O. Box 24005, 1700 Nicosia (Cyprus); Christov, C. I. [Department of Mathematics, University of Louisiana at Lafayette, LA 70504-1010 (United States); Jordan, P. M. [Entropy Reversal Consultants (L.L.C), P. O. Box 691, Abita Springs, LA 70420 (United States); Code 7181, Naval Research Lab., Stennis Space Ctr., MS 39529 (United States)

2009-10-29T23:59:59.000Z

332

Thermal Gradient Holes At Tungsten Mountain Area (Shevenell, Et Al., 2008)  

Open Energy Info (EERE)

Shevenell, Et Al., 2008) Shevenell, Et Al., 2008) Exploration Activity Details Location Tungsten Mountain Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness useful DOE-funding Unknown Notes Collaboration with the gold mining industry has brought two new geothermal discoveries to the attention of the geothermal community. Exploration holes at Tungsten Mountain and McGuiness Hills (Figure 1) in 2004 and 2005 encountered hot water and steam at depths of meters with fluid geothermometry indicating reservoir temperatures of 170 to 200oC. More information can be obtained from the Nevada Bureau of Mines and Geology web site (www.nbmg.unr.edu/geothermal/gtmap.pdf), and from a PowerPoint presentation titled 'Geothermal Exploration Short Stories' posted on the Geothermal Resources Council web site

333

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

Science Conference Proceedings (OSTI)

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

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

2008-09-29T23:59:59.000Z

334

Wind Mixing In a Turbulent Surface Layer in the Presence of a Horizontal Density Gradient  

Science Conference Proceedings (OSTI)

The effect of a horizontal density gradient of buoyancy on the turbulent kinetic energy budget of the surface mixed layer in the ocean is discussed. The combination of a horizontal buoyancy gradient and a vertical shear of the horizontal velocity ...

Johan Rodhe

1991-07-01T23:59:59.000Z

335

Eddy-Driven Buoyancy Gradients on Eastern Boundaries and Their Role in the Thermocline  

Science Conference Proceedings (OSTI)

It is demonstrated that eddy fluxes of buoyancy at the eastern and western boundaries maintain alongshore buoyancy gradients along the coast. Eddy fluxes arise near the eastern and western boundaries because on both coasts buoyancy gradients ...

Paola Cessi; Christopher L. Wolfe

2009-07-01T23:59:59.000Z

336

The Gradient Genesis of Stratospheric Trace Species in the Subtropics and around the Polar Vortex  

Science Conference Proceedings (OSTI)

Mechanisms that control the formation and decay of meridional gradients in stratospheric trace species in the subtropics and around the polar vortex are investigated using a gradient genesis equation that uses mass-weighted isentropic zonal ...

Kazuyuki Miyazaki; Toshiki Iwasaki

2008-02-01T23:59:59.000Z

337

Spatiotemporal Variation of the Vertical Gradient of Rainfall Rate Observed by the TRMM Precipitation Radar  

Science Conference Proceedings (OSTI)

Seasonal and spatial variation of the vertical gradient of rainfall rate was investigated using global precipitation data observed by the Precipitation Radar (PR) on the Tropical Rainfall Measuring Mission (TRMM) satellite. The vertical gradient ...

Masafumi Hirose; Kenji Nakamura

2004-09-01T23:59:59.000Z

338

Adaptive nearest-nodes finite element method guided by gradient of linear strain energy density  

Science Conference Proceedings (OSTI)

In this paper, an adaptive finite element method is formulated based on the newly developed nearest-nodes finite element method (NN-FEM). In the adaptive NN-FEM, mesh modification is guided by the gradient of strain energy density, i.e., a larger gradient ... Keywords: Gradient of strain energy density, Mesh intensity, Mesh modification operator, Nearest-nodes finite element method

Yunhua Luo

2009-10-01T23:59:59.000Z

339

Data acquisition for low-temperature geothermal well tests and long-term monitoring. Final report  

DOE Green Energy (OSTI)

Groundwater monitoring is an essential part of the development of a low-temperature geothermal field for production and injection wells. State water resource and environmental departments are requiring both geothermal well testing and long-term monitoring as a part of the permitting process for geothermal developments. This report covers water-level measurement methods, instruments used for well testing, geochemical sampling, examples of data acquisition and regulatory mandates on groundwater monitoring.

Lienau, P.J.

1992-09-01T23:59:59.000Z

340

Data acquisition for low-temperature geothermal well tests and long-term monitoring  

DOE Green Energy (OSTI)

Groundwater monitoring is an essential part of the development of a low-temperature geothermal field for production and injection wells. State water resource and environmental departments are requiring both geothermal well testing and long-term monitoring as a part of the permitting process for geothermal developments. This report covers water-level measurement methods, instruments used for well testing, geochemical sampling, examples of data acquisition and regulatory mandates on groundwater monitoring.

Lienau, P.J.

1992-09-01T23:59:59.000Z

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


341

Numerical Simulations of Temperature Field of Coal-Bed Methane with Heat Injection Based on ANSYS  

Science Conference Proceedings (OSTI)

The three-dimensional temperature field of the coal-bed methane with heat injection was numerically calculated by ANSYS. The calculated results revealed that the temperature, the thermal gradients and the thermal flux vector sum of the coal-bed near ... Keywords: heat injection, numerical simulation, temperature

Bing Xiong Lu

2012-03-01T23:59:59.000Z

342

Geochemical data package for the Hanford immobilized low-activity tank waste performance assessment (ILAW PA)  

Science Conference Proceedings (OSTI)

Lockheed Martin Hanford Company (LMHC) is designing and assessing the performance of disposal facilities to receive radioactive wastes that are stored in single- and double-shell tanks at the Hanford Site. The preferred method of disposing of the portion that is classified as low-activity waste is to vitrify the liquid/slurry and place the solid product in near-surface, shallow-land burial facilities. The LMHC project to assess the performance of these disposal facilities is the Hanford Immobilized Low-Activity Tank Waste (ILAW) Performance Assessment (PA) activity. The goal of this project 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 porewater of the vadose zone. Pacific Northwest National Laboratory assists LMHC in their performance assessment activities. One of the PNNL tasks is to provide estimates of the geochemical properties of the materials comprising the disposal facility, 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 (K{sub d}) and the thermodynamic solubility product (K{sub sp}), respectively. In this data package, the authors approximate the solubility of contaminants using a more simplified construct, called the solution concentration limit, a constant value. In future geochemical data packages, they will determine whether a more rigorous measure of solubility is necessary or warranted based on the dose predictions emanating from the ILAW 2001 PA and reviewers' comments. The K{sub d}s and solution concentration limits for each contaminant are direct inputs to subsurface flow and transport codes used to predict the performance of the ILAW system. In addition to the best-estimate K{sub d}s, a reasonable conservative value and a range are provided. They assume that K{sub d} values are log normally distributed over the cited ranges. Currently, they do not give estimates for the range in solubility limits or their uncertainty. However, they supply different values for both the K{sub d}s and solution concentration limits for different spatial zones in the ILAW system and supply time-varying K{sub d}s for the concrete zone, should the final repository design include concrete vaults or cement amendments to buffer the system pH.

DI Kaplan; RJ Serne

2000-02-24T23:59:59.000Z

343

TRENDS: TEMPERATURE  

NLE Websites -- All DOE Office Websites (Extended Search)

Historical Isotopic Temperature Record from the Vostok Ice Core Historical Isotopic Temperature Record from the Vostok Ice Core Graphics Digital Data J.R. Petit, D. Raynaud, and C. Lorius Laboratoire de Glaciogie et Géophysique de l'Environnement, CNRS, Saint Martin d'Hères Cedex, France J. Jouzel and G. Delaygue Laboratoire des Sciences du Climat et de l'Environnement (LSCE), CEA/CNRS, L'Orme des Merisiers, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France N.I. Barkov Arctic and Antarctic Research Institute, Beringa Street 38, 199397 St. Petersburg, Russia V.M. Kotlyakov Institute of Geography, Staromonetny, per 29, Moscow 109017, Russia DOI: 10.3334/CDIAC/cli.006 Period of Record 420,000 years BP-present Methods Because isotopic fractions of the heavier oxygen-18 (18O) and deuterium (D) in snowfall are temperature-dependent and a strong spatial correlation

344

Gradient effects on the fracture of inhomogeneous materials  

SciTech Connect

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.

Becker, T.L.

2000-05-01T23:59:59.000Z

345

The LLNL/UCLA high gradient inverse free electron laser  

SciTech Connect

We describe the Inverse Free Electron Accelerator currently under construction at Lawrence Livermore National Lab. Upon completion of this accelerator, high brightness electrons generated in the photoinjector blowout regime and accelerated to 50 MeV by S-band accelerating sections will interact with > 4 TW peak power Ti:Sapphire laser in a highly tapered 50 cm undulator and experience an acceleration gradient of > 200 MeV/m. We present the final design of the accelerator as well as the results of start-to-end simulations investigating preservation of beam quality and tolerances involved with this accelerator.

Moody, J. T.; Musumeci, P.; Anderson, G.; Anderson, S.; Betts, S.; Fisher, S.; Gibson, D.; Tremaine, A.; Wu, S. [Department of Physics and Astronomy, UCLA, Los Angeles California, 90095 (United States); Lawrence Livermore National Laboratory (United States)

2012-12-21T23:59:59.000Z

346

Gradient index liquid crystal devices and method of fabrication thereof  

DOE Patents (OSTI)

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

Lee, Jae-Cheul (Rochester, NY); Jacobs, Stephen (Pittsford, NY)

1991-01-01T23:59:59.000Z

347

Gradient index liquid crystal devices and method of fabrication thereof  

DOE Patents (OSTI)

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

Lee, J.C.; Jacobs, S.

1991-10-29T23:59:59.000Z

348

Core-based integrated sedimentologic, stratigraphic, and geochemical analysis of the oil shale bearing Green River Formation, Uinta Basin, Utah  

NLE Websites -- All DOE Office Websites (Extended Search)

DOE Award No.: DE-FE0001243 DOE Award No.: DE-FE0001243 Topical Report CORE-BASED INTEGRATED SEDIMENTOLOGIC, STRATIGRAPHIC, AND GEOCHEMICAL ANALYSIS OF THE OIL SHALE BEARING GREEN RIVER FORMATION, UINTA BASIN, UTAH Submitted by: University of Utah Institute for Clean and Secure Energy 155 South 1452 East, Room 380 Salt Lake City, UT 84112 Prepared for: United States Department of Energy National Energy Technology Laboratory April 2011 Oil & Natural Gas Technology Office of Fossil Energy Core-based integrated sedimentologic, stratigraphic, and geochemical analysis of the oil shale bearing Green River Formation, Uinta Basin, Utah Topical Report Reporting Period: October 31, 2009 through March 31, 2011 Authors: Lauren P. Birgenheier, Energy and Geoscience Insitute, University of Utah

349

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

DOE Green Energy (OSTI)

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)

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

1985-01-01T23:59:59.000Z

350

Injection and Reservoir Hazard Management: Mechanical Deformation and Geochemical Alteration at the InSalah CO2 Storage Project  

NLE Websites -- All DOE Office Websites (Extended Search)

Injection and Reservoir Hazard Injection and Reservoir Hazard Management: Mechanical Deformation and Geochemical Alteration at the In Salah CO 2 Storage Project Background Safe and permanent storage of carbon dioxide (CO 2 ) in geologic reservoirs is critical to geologic sequestration. The In Salah Project (joint venture of British Petroleum (BP), Sonatrach, and StatoilHydro) has two fundamental goals: (1) 25-30 years of 9 billion cubic feet per year (bcfy) natural gas production from 8 fields in the Algerian

351

The application of PHREEQCi, a geochemical computer program, to aid in the management of a wastewater treatment wetland  

E-Print Network (OSTI)

In the past decade, constructed wetlands have become popular for treating coal-generated acid mine drainage and leachate from coal-ash disposal areas. The goal of the wetland manager is to design a system in which the pH is neutralized, toxic metals are removed, and wetland discharge meets or exceeds discharge standards for water quality. This is typically accomplished by using a combination of wetlands, ponds, and limestone drains. The treatment capability of a constructed wetland is based on relationships among dissolved oxygen (DO), pH, and metal speciation. The aim of this research was to determine if PHREEQCi, a geochemical computer program, could be used in wetland management and design. The wetland site chosen for this study was at a Texas Municipal Power Agency (TMPA) plant located in Grimes County, Texas and was created to treat leachate from a solid waste disposal area where coal ash and SO? scrubber sludge was deposited. The leachate contains significant concentrations of sulfate, chloride, total dissolved solids (TDS), arsenic, and selenium. Using PHREEQCi, geochemical speciation models were created to study the interrelationships between critical chemical components at the TMPA site in order to establish an optimum set of conditions to improve treatment capability and to avoid wetland failure. The results of the geochemical speciation modeling indicated a challenging situation for a wetland manager because different species precipitate under contrasting environments. In order to apply the geochemical speciation results to the design of the TMPA site, two conditions must be recognized. First, metal removal is best accomplished by generating alkaline and oxidative conditions to promote metal-oxide precipitation. Second, sulfate can be controlled under reducing environments where it is converted to sulfide and metal sulfides precipitate. Chlorides are very soluble and no viable conclusions as to the most appropriate removal method could be postulated. TDS has an ambiguous composition and could not be modeled using PHREEQCi.

Mitzman, Stephanie

1999-01-01T23:59:59.000Z

352

Acceleration disturbances due to local gravity gradients in ASTROD I  

E-Print Network (OSTI)

The Astrodynamical Space Test of Relativity using Optical Devices (ASTROD) mission consists of three spacecraft in separate solar orbits and carries out laser interferometric ranging. ASTROD aims at testing relativistic gravity, measuring the solar system and detecting gravitational waves. Because of the larger arm length, the sensitivity of ASTROD to gravitational waves is estimated to be about 30 times better than Laser Interferometer Space Antenna (LISA) in the frequency range lower than about 0.1 mHz. ASTROD I is a simple version of ASTROD, employing one spacecraft in a solar orbit. It is the first step for ASTROD and serves as a technology demonstration mission for ASTROD. In addition, several scientific results are expected in the ASTROD I experiment. The required acceleration noise level of ASTROD I is 10^-13 m s^-2 Hz^{-1/2} at the frequency of 0.1 mHz. In this paper, we focus on local gravity gradient noise that could be one of the largest acceleration disturbances in the ASTROD I experiment. We have carried out gravitational modelling for the current test-mass design and simplified configurations of ASTROD I by using an analytical method and the Monte Carlo method. Our analyses can be applied to figure out the optimal designs of the test mass and the constructing materials of the spacecraft, and the configuration of compensation mass to reduce local gravity gradients.

Sachie Shiomi

2005-10-10T23:59:59.000Z

353

EFFECTS OF NON-CIRCULAR MOTIONS ON AZIMUTHAL COLOR GRADIENTS  

Science Conference Proceedings (OSTI)

Assuming that density waves trigger star formation, and that young stars preserve the velocity components of the molecular gas where they are born, we analyze the effects that non-circular gas orbits have on color gradients across spiral arms. We try two approaches, one involving semianalytical solutions for spiral shocks, and another with magnetohydrodynamic (MHD) numerical simulation data. We find that, if non-circular motions are ignored, the comparison between observed color gradients and stellar population synthesis models would in principle yield pattern speed values that are systematically too high for regions inside corotation, with the difference between the real and the measured pattern speeds increasing with decreasing radius. On the other hand, image processing and pixel averaging result in systematically lower measured spiral pattern speed values, regardless of the kinematics of stellar orbits. The net effect is that roughly the correct pattern speeds are recovered, although the trend of higher measured OMEGA{sub p} at lower radii (as expected when non-circular motions exist but are neglected) should still be observed. We examine the MartInez-GarcIa et al. photometric data and confirm that this is indeed the case. The comparison of the size of the systematic pattern speed offset in the data with the predictions of the semianalytical and MHD models corroborates that spirals are more likely to end at outer Lindblad resonance, as these authors had already found.

Martinez-Garcia, Eric E. [Centro de Investigaciones de Astronomia, Apartado Postal 264, Merida 5101-A (Venezuela, Bolivarian Republic of); Gonzalez-Lopezlira, Rosa A.; Gomez, Gilberto C., E-mail: emartinez@cida.v, E-mail: r.gonzalez@crya.unam.m, E-mail: g.gomez@crya.unam.m [Centro de Radioastronomia y Astrofisica, UNAM, Campus Morelia, Michoacan, C.P. 58089 (Mexico)

2009-12-20T23:59:59.000Z

354

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

Science Conference Proceedings (OSTI)

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.

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

355

Geochemical Fingerprinting of Coltan Ores by Machine Learning on Uneven Datasets  

Science Conference Proceedings (OSTI)

Two modern machine learning techniques, Linear Programming Boosting (LPBoost) and Support Vector Machines (SVMs), are introduced and applied to a geochemical dataset of niobium-tantalum ('coltan') ores from Central Africa to demonstrate how such information may be used to distinguish ore provenance, i.e., place of origin. The compositional data used include uni- and multivariate outliers and elemental distributions are not described by parametric frequency distribution functions. The 'soft margin' techniques of LPBoost and SVMs can be applied to such data. Optimization of their learning parameters results in an average accuracy of up to c. 92%, if spot measurements are assessed to estimate the provenance of ore samples originating from two geographically defined source areas. A parameterized performance measure, together with common methods for its optimization, was evaluated to account for the presence of uneven datasets. Optimization of the classification function threshold improves the performance, as class importance is shifted towards one of those classes. For this dataset, the average performance of the SVMs is significantly better compared to that of LPBoost.

Savu-Krohn, Christian, E-mail: christian.savu-krohn@unileoben.ac.at; Rantitsch, Gerd, E-mail: gerd.rantitsch@unileoben.ac.at [Montanuniversitaet Leoben, Department of Applied Geosciences and Geophysics (Austria); Auer, Peter, E-mail: auer@unileoben.ac.at [Chair for Information Technology, Montanuniversitaet Leoben (Austria); Melcher, Frank, E-mail: frank.melcher@bgr.de; Graupner, Torsten, E-mail: torsten.graupner@bgr.de [Federal Institute for Geosciences and Natural Resources (Germany)

2011-09-15T23:59:59.000Z

356

Changes in Bacterial And Archaeal Community Structure And Functional Diversity Along a Geochemically Variable Soil Profile  

SciTech Connect

Spatial heterogeneity in physical, chemical, and biological properties of soils allows for the proliferation of diverse microbial communities. Factors influencing the structuring of microbial communities, including availability of nutrients and water, pH, and soil texture, can vary considerably with soil depth and within soil aggregates. Here we investigated changes in the microbial and functional communities within soil aggregates obtained along a soil profile spanning the surface, vadose zone, and saturated soil environments. The composition and diversity of microbial communities and specific functional groups involved in key pathways in the geochemical cycling of nitrogen, Fe, and sulfur were characterized using a coupled approach involving cultivation-independent analysis of both 16S rRNA (bacterial and archaeal) and functional genes (amoA and dsrAB) as well as cultivation-based analysis of Fe(III)-reducing organisms. Here we found that the microbial communities and putative ammonia-oxidizing and Fe(III)-reducing communities varied greatly along the soil profile, likely reflecting differences in carbon availability, water content, and pH. In particular, the Crenarchaeota 16S rRNA sequences are largely unique to each horizon, sharing a distribution and diversity similar to those of the putative (amoA-based) ammonia-oxidizing archaeal community. Anaerobic microenvironments within soil aggregates also appear to allow for both anaerobic- and aerobic-based metabolisms, further highlighting the complexity and spatial heterogeneity impacting microbial community structure and metabolic potential within soils.

Hansel, C.M.; Fendorf, S.; Jardine, P.M.; Francis, C.A.

2009-05-18T23:59:59.000Z

357

Low temperature ion source for calutrons  

DOE Patents (OSTI)

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.

Veach, A.M.; Bell, W.A. Jr.; Howell, G.D. Jr.

1979-10-10T23:59:59.000Z

358

Low temperature ion source for calutrons  

DOE Patents (OSTI)

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.

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

359

Dielectric-Lined High-Gradient Accelerator Structure  

Science Conference Proceedings (OSTI)

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

Jay L. Hirshfield

2012-04-24T23:59:59.000Z

360

Comparison of Forest Soil Carbon Dynamics at Five Sites Along a Latitudinal Gradient  

SciTech Connect

Carbon stocks, and C:N ratios, were measured in the forest floor, mineral soil, and two mineral soil fractions (particulate and mineral-associated organic matter, POM and MOM, respectively) at five forest sites, ranging from 60 to 100 years old, along a latitudinal gradient in the eastern United States. Sampling at four sites was replicated over two consecutive years. For many measurements (like forest floor carbon stocks, cumulative soil organic carbon stocks to 20 cm, and the fraction of whole soil carbon in POM), there was no significant difference between years at each site despite the use of somewhat different sampling methods. With one exception, forest floor and mineral soil carbon stocks increased from warm, southern, sites (with fine-textured soils) to northern, cool, sites (with more coarse-textured soils). The exception was a northern site, with less than 10% silt-clay content, that had a soil organic carbon stock similar to those measured at southern sites. Soil carbon at each site was partitioned into two pools (labile and stable) on the basis of carbon measured in the forest floor and POM and MOM fractions from the mineral soil. A two-compartment steady-state model, with randomly varying parameter values, was used in probabilistic calculations to estimate the turnover time of labile soil organic carbon (MRTU) and the annual transfer of labile carbon to stable carbon (k2) at each site in two different years. Based on empirical data, the turnover time of stable soil carbon (MRTS) was determined by mean annual temperature and increased from 30 to 100 years from south to north. Moving from south to north, MRTU increased from approximately 5 to 14 years. Consistent with prior studies, 13C enrichment factors ( ) from the Rayleigh equation, that describe the rate of change in 13C through the soil profile, were an indicator of soil carbon turnover times along the latitudinal gradient. Consistent with its role in stabilization of soil organic carbon, silt-clay content along the gradient was positively correlated (r = 0.91; P 0.001) with parameter k2. Mean annual temperature was indicated as the environmental factor most strongly associated with south to north differences in the storage and turnover of labile soil carbon. However, soil texture appeared to override the influence of temperature when there was too little silt-clay content to stabilize labile soil carbon and thereby protect it from decomposition. Irrespective of latitudinal differences in measured soil carbon stocks, each study site had a relatively high proportion of labile soil carbon (approximately 50% of whole soil carbon to a depth of 20 cm). Depending on unknown temperature sensitivities, large labile pools of forest soil carbon are potentially at risk of depletion by decomposition in a warming climate, and losses could be disproportionately higher from coarse textured forest soils.

Garten Jr, Charles T [ORNL

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature gradient geochemical" from the National Library of EnergyBeta (NLEBeta).
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361

Geochemical and Petrological Investigations into Mantle Minerals from Experiments and Natural Samples  

E-Print Network (OSTI)

in stable isotope geochemistry. Geochimica et Cosmochimicafor high-temperature geochemistry if relevant fractionationstatistical method to geochemistry. International Geology

Macris, Catherine Amy

2012-01-01T23:59:59.000Z

362

Quantitative analysis of damage in PBX 9501 subjected to a linear thermal gradient  

SciTech Connect

We have conducted a series of experiments in which a cylinder of PBX 9501 is placed in a specially designed fixture with each end fixed at a different temperature. This arrangement sets up a thermal gradient in the explosive that is carefully controlled and maintained for a specified amount of time. This configuration has a number of advantages over thermally damaging separate pieces at a series of different temperatures, the principal one being that damage in this experiment is a continuous function of position. This makes analysis and distinction of regions easier and more straightforward. For the experiments reported in this paper, the explosive samples have been subjected to a series of different analysis techniques. We have used polarized light microscopy, physical adsorption, Raman spectroscopy, and small angle neutron and x-ray scattering in an attempt to characterize the particle morphology, porosity distribution, crack and void formation, and chemical state as a function of thermal treatment. While not all of the efforts were informative, the data clearly show trends and form a basis for understanding the effects of thermal damage on explosive behavior.

Asay, B. W. (Blaine W.); Henson, B. F. (Bryan F.); Peterson, P. D. (Paul D.); Mang, J. T. (Joseph T.); Smilowitz, L. B. (Laura B.); Dickson, P. M. (Peter M.)

2002-01-01T23:59:59.000Z

363

Tecuamburro Volcano, Guatemala geothermal gradient core hole drilling, operations, and preliminary results  

SciTech Connect

A geothermal gradient core hole (TCB-1) was drilled to a depth of 700+ m at the Tecuamburro geothermal site, Guatemala during February and March, 1990. The core hole is located low on the northern flank of the Tecuamburro Volcano complex. Preliminary analysis of cores (>98% core recovery) indicates that the hydrothermal system may be centered in the 4-km-diameter Chupadero Crater, which has been proposed as the source of pyroxene pumice deposits in the Tecuamburro area. TCB-1 is located 300 m south of a 300-m-diameter phreatic crater, Laguna Ixpaco; the core hole penetrates the thin edge of a tuff ring surrounding Ixpaco and zones of hydrothermal brecciation within the upper 150 m may be related to the phreatic blast, dated at 2,910 {sup 14}C years. At the time of this writing, the unequilibrated temperature at a depth of 570m was 180{degree}C. Data on fracturing, permeability, hydrothermal alteration, and temperature will be presented. 3 refs., 3 figs.

Goff, S.; Heiken, G.; Goff, F.; Gardner, J. (Los Alamos National Lab., NM (USA)); Duffield, W. (Geological Survey, Flagstaff, AZ (USA)); Martinelli, L.; Aycinena, S. (Swissboring Overseas Corp. Ltd., Guatemala City (Guatemala)); Castaneda, O. (Unidad de Desarrollo Geotermico, Guatemala City (Guatemala). Inst. Nacional de Electrificacion)

1990-01-01T23:59:59.000Z

364

Salinity gradient solar pond technology applied to potash solution mining  

DOE Green Energy (OSTI)

A solution mining facility at the Eddy Potash Mine, Eddy County, New Mexico has been proposed that will utilize salinity gradient solar pond (SGSP) technology to supply industrial process thermal energy. The process will include underground dissolution of potassium chloride (KCl) from pillars and other reserves remaining after completion of primary room and pillar mining using recirculating solutions heated in the SGSP. Production of KCl will involve cold crystallization followed by a cooling pond stage, with the spent brine being recirculated in a closed loop back to the SGSP for reheating. This research uses SGSP as a renewable, clean energy source to optimize the entire mining process, minimize environmental wastes, provide a safe, more economical extraction process and reduce the need for conventional processing by crushing, grinding and flotation. The applications of SGSP technology will not only save energy in the extraction and beneficiation processes, but also will produce excess energy available for power generation, desalination, and auxiliary structure heating.

Martell, J.A.; Aimone-Martin, C.T.

2000-06-12T23:59:59.000Z

365

Beta function measurement in the Tevatron using quadrupole gradient modulation  

SciTech Connect

Early in Run2, there was an effort to compare the different emittance measurements in the Tevatron (flying wires and synchrotron light) and understand the origin of the observed differences. To measure the beta function at a few key locations near the instruments, air-core quadrupoles were installed. By modulating the gradient of these magnets and measuring the effect on the tune, the lattice parameters can be extracted. Initially, the results seem to disagree with other methods. At the time, the lattice was strongly coupled due to a skew component in the main dipoles, caused by sagging of the cryostat. After a large fraction of the superconducting magnets were shimmed to remove a strong skew quadrupole component, the results now agree with the theoretical values to within 20%.

Jansson, A.; Lebrun, P.; Volk, J.T.; /Fermilab

2005-05-01T23:59:59.000Z

366

Ducted kinetic Alfven waves in plasma with steep density gradients  

SciTech Connect

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

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

2011-11-15T23:59:59.000Z

367

Modeling high gradient magnetic separation from biological fluids.  

SciTech Connect

A proposed portable magnetic separator consists of an array of biocompatible capillary tubing and magnetizable wires immersed in an externally applied homogeneous magnetic field. While subject to the homogeneous magnetic field, the wires create high magnetic field gradients, which aid in the collection of blood-borne magnetic nanospheres from blood flow. In this study, a 3-D numerical model was created using COMSOL Multiphysics 3.2 software to determine the configuration of the wire-tubing array from two possible configurations, one being an array with rows alternating between wires and tubing, and the other being an array where wire and tubing alternate in two directions. The results demonstrated that the second configuration would actually capture more of the magnetic spheres. Experimental data obtained by our group support this numerical result.

Bockenfeld, D.; Chen, H.; Rempfer, D.; Kaminski, M. D.; Rosengart, A. J.; Chemical Engineering; Illinois Inst. of Tech.; Univ. of Chicago, Pritzker School of Medicine

2006-01-01T23:59:59.000Z

368

Modified Magnicon for High-Gradient Accelerator R&D  

Science Conference Proceedings (OSTI)

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

Jay L. Hirshfield

2011-12-19T23:59:59.000Z

369

Thermal Gradient Holes At Coso Geothermal Area (1974) | Open Energy  

Open Energy Info (EERE)

Coso Geothermal Area (1974) Coso Geothermal Area (1974) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Thermal Gradient Holes Activity Date 1974 Usefulness useful DOE-funding Unknown Exploration Basis Use heat flow studies for the first time at Coso to indicate the presence or absence of abnormal heat Notes Located 10 sites for heat flow boreholes using available seismic ground noise and electrical resistivity data; data collected from 9 of 10; thermal conductivity measurements were completed using both the needle probe technique and the divided bar apparatus with a cell arrangement. In the upper few hundred meters of the subsurface heat is being transferred by a conductive heat transfer mechanism with a value of ~ 15 µcal/cm2sec; the background heat flow is ~ 3.5 HFU.

370

Beamline Temperatures  

NLE Websites -- All DOE Office Websites (Extended Search)

Temperatures Temperatures Energy: 3.0000 GeV Current: 493.2242 mA Date: 11-Jan-2014 21:40:00 Beamline Temperatures Energy 3.0000 GeV Current 493.2 mA 11-Jan-2014 21:40:00 LN:MainTankLevel 124.4 in LN:MainTankPress 56.9 psi SPEAR-BL:B120HeFlow 15.4 l/min SPEAR-BL:B131HeFlow 22.2 l/min BL 4 BL02:LCW 0.0 ℃ BL02:M0_LCW 31.5 ℃ BL 4-1 BL04-1:BasePlate -14.0 ℃ BL04-1:Bottom1 46.0 ℃ BL04-1:Bottom2 47.0 ℃ BL04-1:Lower 32.0 ℃ BL04-1:Moly 46.0 ℃ BL04-1:ChinGuard1 31.0 ℃ BL04-1:ChinGuard2 31.0 ℃ BL04-1:FirstXtalA -167.0 ℃ BL04-1:FirstXtalB -172.0 ℃ BL04-1:Pad1 31.0 ℃ BL04-1:Pad2 31.0 ℃ BL04-1:SecondXtalA -177.0 ℃ BL04-1:SecondXtalB -175.0 ℃ BL 4-2 BL04-2:BasePlate -14.0 ℃ BL04-2:Bottom1 24.0 ℃ BL04-2:Bottom2 25.0 ℃

371

THE EXTENSIVE AGE GRADIENT OF THE CARINA DWARF GALAXY  

Science Conference Proceedings (OSTI)

The evolution of small systems such as dwarf spheroidal galaxies (dSphs) is likely to have been a balance between external environmental effects and internal processes within their own relatively shallow potential wells. Assessing how strong such environmental interactions may have been is therefore an important element in understanding the baryonic evolution of dSphs and their derived dark matter distribution. Here we present results from a wide-area CTIO/MOSAIC II photometric survey of the Carina dSph, reaching down to about two magnitudes below the oldest main-sequence turnoff (MSTO). This data set enables us to trace the structure of Carina in detail out to very large distances from its center, and as a function of stellar age. We observe the presence of an extended structure made up primarily of ancient MSTO stars, at distances between 25' and 60' from Carina's center, confirming results in the literature that Carina extends well beyond its nominal tidal radius. The large number statistics of our survey reveals features such as isophote twists and tails that were undetected in other previous, shallower surveys. This is the first time that such unambiguous signs of tidal disruption have been found in a Milky Way 'classical' dwarf other than Sagittarius. We also demonstrate the presence of a negative age gradient in Carina directly from its MSTOs, and trace it out to very large distances from the galaxy center. The signs of interaction with the Milky Way make it unclear whether the age gradient was already in place before Carina underwent tidal disruption.

Battaglia, G. [INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Irwin, M. [Institute of Astronomy, Madingley Road, Cambridge CB03 0HA (United Kingdom); Tolstoy, E.; De Boer, T. [Kapteyn Astronomical Institute, University of Groningen, P.O. Box 800, 9700 AV Groningen (Netherlands); Mateo, M., E-mail: gbattaglia@oabo.inaf.it [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109-1090 (United States)

2012-12-20T23:59:59.000Z

372

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

Science Conference Proceedings (OSTI)

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.

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

2004-09-30T23:59:59.000Z

373

Relationship of the Variances of Temperature and Velocity to Atmospheric Static Stability—Application to Radar and Acoustic Sounding  

Science Conference Proceedings (OSTI)

The relationship between the variances of temperature and vertical velocity fluctuations is examined experimentally and theoretically. Comparison of the variance data and the mean gradient data recorded on the 300 m tower at the Boulder ...

Earl E. Gossard; A. Shelby Frisch

1987-08-01T23:59:59.000Z

374

Heat flow and geothermal gradients of Irian Jaya-Papua New Guinea: Implications for regional hydrocarbon exploration  

Science Conference Proceedings (OSTI)

Compilation of published and unpublished bottom hole temperatures (corrected for circulation times) obtained from open files and reports of the Indonesian Petroleum Association, Papua Geologic Survey, and the Southeast Asia Petroleum Society, together with published oceanographic heat flow analyses from the surrounding seas, allow an analysis of the regional heat flow and geothermal gradients of New Guinea. In two dimensions the thermal trends may be described as a pervasive west-northwest striking Cordilleran core of cool (2 HFU->4{degree}C/100 m) on the northwest, northeast, east, and southwest. As a first approximation, the heat flow may be viewed as directly proportional to the crustal thickness (as demonstrated from north-south transects across the Central Cordillera), inversely proportional to the age of the ocean crust (offshore), and perturbed by crustal heterogeneities proximal to plate boundaries (e.g., the Northern New Guinea Fault System). As a result, the heat flow distribution affords a record of post-Cretaceous tectonic activities of New Guinea. Using the spatial distribution of geothermal gradients and specific source rock ages, kinetic calculations of hydrocarbon maturities confirmed by recent drilling results suggest thermal variations through space and time that cannot be modeled simply as a function of present day static temperatures. Therefore, in terms of utilizing the present thermal information, hydrocarbon basin exploration strategies must also take into account the tectonically perturbed heat flow history of the region.

Bettis, P.K. (Expatriate-Congo, Houston, TX (USA)); Pigott, J.D. (Univ. of Oklahoma, Norman (USA))

1990-06-01T23:59:59.000Z

375

Geochemical engineering design tools for uranium in situ recovery : the HYDROGEOCHEM codes.  

SciTech Connect

Geochemical Engineering Design (GED) is based on applications of the principles and various computer models that describe the biogeochemistry and physics of removal of contaminants from water by adsorption, precipitation and filtration. It can be used to optimize or evaluate the efficiency of all phases of in situ recovery (ISR). The primary tools of GED are reactive transport models; this talk describes the potential application of the HYDROGEOCHEM family of codes to ISR. The codes can describe a complete suite of equilibrium or kinetic aqueous complexation, adsorption-desorption, precipitation-dissolution, redox, and acid-base reactions in variably saturated media with density-dependent fluid flow. Applications to ISR are illustrated with simulations of (1) the effectiveness of a reactive barrier to prevent off-site uranium migration and (2) evaluation of the effect of sorption hysteresis on natural attenuation. In the first example, it can be seen that the apparent effectiveness of the barrier depends on monitoring location and that it changes over time. This is due to changes in pH, saturation of sorption sites, as well as the geometry of the flow field. The second simulation shows how sorption hysteresis leads to observable attenuation of a uranium contamination plume. Different sorption mechanisms including fast (or reversible), slow, and irreversible sorption were simulated. The migration of the dissolved and total uranium plumes for the different cases are compared and the simulations show that when 50-100% of the sites have slow desorption rates, the center of mass of the dissolved uranium plume begins to move upstream. This would correspond to the case in which the plume boundaries begin to shrink as required for demonstration of natural attenuation.

Siegel, Malcolm Dean; Li, Ming-Hsu (National Central University, Jhongli City, Taiwan); Yeh, Gour-Tsyh (University of Central Florida, Orlando, FL)

2010-11-01T23:59:59.000Z

376

Thermal Gradient Holes At Socorro Mountain Area (Owens, Et Al., 2005) |  

Open Energy Info (EERE)

Thermal Gradient Holes At Socorro Mountain Area (Owens, Et Al., 2005) Thermal Gradient Holes At Socorro Mountain Area (Owens, Et Al., 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Socorro Mountain Area (Owens, Et Al., 2005) Exploration Activity Details Location Socorro Mountain Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness not indicated DOE-funding Unknown Notes Pre-existing evidence includes heat gradients of upwards of 490mW/m2 from thermal-gradient wells, tepid spring waters (32oC) and silica geochemistry indicating thermal waters with a minimum of 82 degrees C at depth References Lara Owens, Richard Baars, David Norman, Harold Tobin (2005) New Methods In Exploration At The Socorro Peak Kgra- A Gred Iii Project Retrieved from

377

A real-time implementation of gradient domain high dynamic range compression using a local Poisson solver  

Science Conference Proceedings (OSTI)

This paper presents a real-time hardware implementation of a gradient domain dynamic range compression algorithm for high dynamic range (HDR) images. This technique works by calculating the gradients of the HDR image, manipulating those gradients, and ... Keywords: Embedded hardware, Gradient domain dynamic range compression, Poisson equation, Real time, Tone mapping operator

Lavanya Vytla; Firas Hassan; Joan E. Carletta

2013-06-01T23:59:59.000Z

378

Infrared Imaging of Temperature Distribution in a High Temperature X-Ray Diffraction Furnace  

Science Conference Proceedings (OSTI)

High Temperature X-ray Diffraction (HTXRD) is a very powerful tool for studies of reaction kinetics, phase transformations, and lattice thermal expansion of advanced materials. Accurate temperature measurement is a critical part of the technique. Traditionally, thermocouples, thermistors, and optical pyrometers have been used for temperature control and measurement and temperature could only be measured at a single point. Infrared imaging was utilized in this study to characterize the thermal gradients resulting from various sample and furnace configurations in a commercial strip heater furnace. Furnace configurations include a metallic strip heater, with and without a secondary surround heater, or a surround heater alone. Sample configurations include low and high thermal conductivity powders and solids. The IR imaging results have been used to calibrate sample temperatures in the HTXRD furnace.

Payzant, E.A.; Wang, H.

1999-04-05T23:59:59.000Z

379

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

NLE Websites -- All DOE Office Websites (Extended Search)

their solubility. This project involve the synthesis of silicate glasses with different bulk compositions pressures, temperatures and at controlled redox conditions in the aim of...

380

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

SciTech Connect

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

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

2013-12-01T23:59:59.000Z

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


381

A Cost-Effective Oxygen Separation System Based on Open Gradient...  

NLE Websites -- All DOE Office Websites (Extended Search)

Feed Systems A Cost-Effective Oxygen Separation System Based on Open Gradient Magnetic Field by Polymer Beads ITN Energy Systems, Inc. Project Number: SC0010151 Project Description...

382

Thermal Gradient Holes At Silver Peak Area (DOE GTP) | Open Energy...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Silver Peak Area (DOE GTP) Exploration Activity Details Location...

383

Thermal Gradient Holes At Alum Area (DOE GTP) | Open Energy Informatio...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Alum Geothermal Area (DOE GTP) Exploration Activity Details...

384

Thermal Gradient Holes At Fort Bliss Area (DOE GTP) | Open Energy...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Fort Bliss Area (DOE GTP) Exploration Activity Details Location...

385

Integrating Ecosystem Sampling, Gradient Modeling, Remote Sensing, and Ecosystem Simulation to Create Spatially Explicit Landscape Inventories  

E-Print Network (OSTI)

ecosystem sampling, gradient modeling, remote sensing, and ecosystem simulation to create spatially explicit landscape inventories. RMRS-GTR-92. Fort Collins, CO: U.S. Department

United States; Forest Service; Robert E. Keane; Matthew G. Rollins; Cecilia H. Mcnicoll; Russell A. Parsons Abstract

2002-01-01T23:59:59.000Z

386

Thermal Gradient Holes At Hot Pot Area (DOE GTP) | Open Energy...  

Open Energy Info (EERE)

Hot Pot Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Hot Pot Area (DOE GTP) Exploration Activity...

387

Effects of the Ti/Al atomic ratio on the properties of gradient (Ti,Al)N films synthesized by ion beam assisted deposition  

SciTech Connect

Gradient (Ti,Al)N films were prepared on high speed steel (HSS) and Si (111) wafers by using two Ar{sup +} beams to sputter a titanium target and an aluminum target separately, and a third N{sup +} beam to simultaneously bombard the growing film to assist deposition. The effects of the Ti/Al atomic ratio in the films on properties such as hardness, stress, and adhesion strength were investigated systematically. The results indicated that both the hardness and the adhesion of gradient (Ti,Al)N films to steel substrates exhibited {open_quotes}peak{close_quotes} type changes with an increase of the Ti/Al atomic ratio, and a maximum hardness of 3780thinspkgfthinspmm{sup {minus}2} was reached at a Ti/Al ratio of 5.35. The compressive stress of gradient (Ti,Al)N films increased with increasing Al content in the films. It was found that extreme hardness, high adhesion strength and low stress gradient (Ti,Al)N films can be synthesized on low temperature HSS steel by using the ion beam assisted deposition process.

He, X.; Shu, L.; Xie, Z.W. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

1999-03-01T23:59:59.000Z

388

Modeling brine-rock interactions in an enhanced geothermal system deep fractured reservoir at Soultz-Sous-Forets (France): a joint approach using two geochemical codes: frachem and toughreact  

E-Print Network (OSTI)

150 p. Bächler, D. , Durst, P. , Evans, K. , Hopkirk, R. ,in Mineralogy, 29: 259-308. Durst, P. , (2002). Geochemical1999. Rabemanana, V. , Durst, P. , Bächler, D. , Vuataz,

Andre, Laurent; Spycher, Nicolas; Xu, Tianfu; Vuataz, Francois-D.; Pruess, Karsten.

2006-01-01T23:59:59.000Z

389

Geological, geochemical, and operational summary, aurora well, OCS Y-0943-1, Beaufort Sea, Alaska. Final report  

Science Conference Proceedings (OSTI)

The Aurora well is located just off the coast of the Arctic National Wildlife Refuge (ANWR). The well was spudded November 2, 1987, in 68 ft of water and plugged and abandoned 286 days later on August 30, 1988, after drilling to a total depth (TD) of 18,325 ft below the Kelly Bushing (RKB). The report presents our interpretations of the geologic and geochemical information collected from the Aurora well. Additionally, a significant section of the report is devoted to the operational aspects of drilling the Aurora well.

Paul, L.E.; Choromanski, D.R.; Turner, R.F.; Flett, T.O.; Paul, L.E.

1994-01-01T23:59:59.000Z

390

SER Temperature Coefficient  

SciTech Connect

Experimentally determine the overall isothermal temperature coefficient of the SER up to the design operating temperatures.

Johnson, J.L.

1959-12-31T23:59:59.000Z

391

Geochemical Characterization of Chromate Contamination in the 100 Area Vadose Zone at the Hanford Site  

Science Conference Proceedings (OSTI)

The major objectives of the proposed study were to: 1.) determine the leaching characteristics of hexavalent chromium [Cr(VI)] from contaminated sediments collected from 100 Area spill sites; 2.) elucidate possible Cr(VI) mineral and/or chemical associations that may be responsible for Cr(VI) retention in the Hanford Site 100 Areas through the use of i.) macroscopic leaching studies and ii.) microscale characterization of contaminated sediments; and 3.) provide information to construct a conceptual model of Cr(VI) geochemistry in the Hanford 100 Area vadose zone. In addressing these objectives, additional benefits accrued were: (1) a fuller understanding of Cr(VI) entrained in the vadose zone that will that can be utilized in modeling potential Cr(VI) source terms, and (2) accelerating the Columbia River 100 Area corridor cleanup by providing valuable information to develop remedial action based on a fundamental understanding of Cr(VI) vadose zone geochemistry. A series of macroscopic column experiments were conducted with contaminated and uncontaminated sediments to study Cr(VI) desorption patterns in aged and freshly contaminated sediments, evaluate the transport characteristics of dichromate liquid retrieved from old pipelines of the 100 Area; and estimate the effect of strongly reducing liquid on the reduction and transport of Cr(VI). Column experiments used the with the column studies. Cr(VI) is found as ubiquitous coatings on sediment grain surfaces. Small, higher concentration, chromium sites are associated with secondary clay mineral inclusions, with occasional barium chromate minerals, and reduced to Cr(III) in association with iron oxides that are most likely magnetite primary minerals. Within the restricted access domains of sediment matrix, ferrous iron could also diffuse from in situ, high-surface-area minerals to cause the reductive immobilization of chromate. This process may be favored at microscale geochemical zones where ferrous iron could be supplied. Once nucleated, micrometer-scale precipitates are favored as growing locales for further accumulation, causing the formation of discrete zones of Cr(III).

Dresel, P. Evan; Qafoku, Nikolla; McKinley, James P.; Fruchter, Jonathan S.; Ainsworth, Calvin C.; Liu, Chongxuan; Ilton, Eugene S.; Phillips, J. L.

2008-07-16T23:59:59.000Z

392

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

SciTech Connect

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.

Dixon, David Adams [The University of Alabama

2013-06-27T23:59:59.000Z

393

Vascular flora and gradient analysis of the Natchez Trace Parkway  

E-Print Network (OSTI)

Vascular plant collections were made on the Natchez Trace Parkway over a 15 month period beginning in August 2004. These collections along with previous work done by the National Park Service (NPS) produced a flora of 750 genera and 2196 species in 167 families. Five collection trips were made so as to include as much of the growing season as possible (August 2004, March, May, July and October 2005). Specimens were collected from 500 sites along the Parkway as well as at 50 quadrat locations. The largest families, by species numbers, are Asteraceae (298 species), Poaceae (236 species), Cyperaceae (148 species), Fabaceae (133 species) and Rosaceae (73 species), which accounted for 40.4% of the flora. A Detrended Correspondence Analysis (DCA) and TWINSPAN analysis were performed on data collected from 49 sites along the length of the Natchez Trace Parkway (NATR). It was found that the major environmental gradient (Axis 1) affecting the species composition of the site was to be the level of disturbance. The sites with high levels of disturbance were characterized as grassland field sites, while those areas with low levels of disturbance were characterized as forested sites. The TWINSPAN analysis produced 29 groupings, of which eight were found to be valid groupings. Through the course of the study, almost 450 new species were added to the current knowledge of the Natchez Trace Parkway by the NPS. In addition, one prospective endangered species was located, which will aid the NPS in future management practices within the park.

Phillips, Nena Mae Monique

2006-08-01T23:59:59.000Z

394

GRADIENT INDEX SPHERES BY THE SEQUENTIAL ACCRETION OF GLASS POWDERS  

Science Conference Proceedings (OSTI)

The Department of Energy is seeking a method for fabricating mm-scale spheres having a refractive index that varies smoothly and continuously from the center to its surface [1]. The fabrication procedure must allow the creation of a range of index profiles. The spheres are to be optically transparent and have a refractive index differential greater than 0.2. The sphere materials can be either organic or inorganic and the fabrication technique must be capable of scaling to low cost production. Mo-Sci Corporation proposed to develop optical quality gradient refractive index (GRIN) glass spheres of millimeter scale (1 to 2 mm diameter) by the sequential accretion and consolidation of glass powders. Other techniques were also tested to make GRIN spheres as the powder-accretion method produced non-concentric layers and poor optical quality glass spheres. Potential ways to make the GRIN spheres were (1) by "coating" glass spheres (1 to 2 mm diameter) with molten glass in a two step process; and (2) by coating glass spheres with polymer layers.

MARIANO VELEZ

2008-06-15T23:59:59.000Z

395

Scrape-off Layer Flows With Pressure Gradient Scale Length ~ {rho}{sub p}  

SciTech Connect

A heuristic model for the plasma scrape-off width balances magnetic drifts against parallel loss at c{sub s} /2, resulting in a SOL width ~ {rho}{sub p}. T{sub sep} is calculated from Spitzer–Härm parallel thermal conduction. This results in a prediction for the power scrape-off width in quantitative agreement both in magnitude and scaling with recent experimental data. To achieve the ~ c{sub s} /2 flow assumed in this model and measured experimentally sets requirements on the ratio of upstream to total SOL particle sources, relative to the square-root of the ratio of target to upstream temperature. The Pfisch-Schlüter model for equilibrium flows has been modified to allow near-sonic flows, appropriate for gradient scale lengths of order {rho}{sub p}, resulting in a new quadrupole radial flow pattern. The strong parallel flows and plasma charging implied by this model suggest a mechanism for H-mode transition, consistent with many observations

Robert J. Goldston

2013-03-08T23:59:59.000Z

396

A class of stochastic gradient algorithms with exponentiated error cost functions  

Science Conference Proceedings (OSTI)

A novel class of stochastic gradient descent algorithms is introduced based on the minimisation of convex cost functions with exponential dependence on the adaptation error, instead of the conventional linear combinations of even moments. The derivation ... Keywords: Adaptive filtering, Cost functions, Online optimisation, Stochastic gradient descent

C. Boukis; D. P. Mandic; A. G. Constantinides

2009-03-01T23:59:59.000Z

397

Density-gradient theory: a macroscopic approach to quantum confinement and tunneling in semiconductor devices  

Science Conference Proceedings (OSTI)

Density-gradient theory provides a macroscopic approach to modeling quantum transport that is particularly well adapted to semiconductor device analysis and engineering. After some introductory observations, the basis of the theory in macroscopic and ... Keywords: Continuum, Density-gradient, Electron transport, Quantum confinement, Quantum tunneling, Semiconductor device simulation, Thermodynamics

M. G. Ancona

2011-06-01T23:59:59.000Z

398

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

E-Print Network (OSTI)

ENERGY SCAVENGING BASED ON TRANSIENT THERMAL GRADIENTS: APPLICATION TO STRUCTURAL HEALTH MONITORING from its environment [2]. A possible source of energy could be thermal gradients. This paper the upper limit for the thermal energy that could be captured, let us consider a sealed tank containing 1 g

Paris-Sud XI, Université de

399

An adaptive finite element method for simulating surface tension with the gradient theory of fluid interfaces  

Science Conference Proceedings (OSTI)

The gradient theory for the surface tension of simple fluids and mixtures is rigorously analyzed based on mathematical theory. The finite element approximation of surface tension is developed and analyzed, and moreover, an adaptive finite element method ... Keywords: 49S05, 65N30, 65N50, Adaptive finite element method, Gradient theory, Surface tension

Jisheng Kou, Shuyu Sun

2014-01-01T23:59:59.000Z

400

Measurement Research of Borehole-to-Surface Electric Potential Gradient Method in Monitoring Hydraulic Fracture  

Science Conference Proceedings (OSTI)

As the main measures to improve oil and gas production, hydraulic fracturing has been widely applied in modern oil industry. By means of lower resistance properties of fracturing fluid, borehole-to-surface electric potential gradient method analyses ... Keywords: borehole-to-surface electric method, Ab normal depth, launch current, polar distance, electric potential gradient

Tingting Li; Kaiguang Zhu; Jia Wang; Chunling Qiu; Jun Lin

2012-04-01T23:59:59.000Z

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


401

Geochemical and Petrological Investigations into Mantle Minerals from Experiments and Natural Samples  

E-Print Network (OSTI)

lherzolite) as the fertile source rock (initial compositionsource mass spectrometry (MC-ICPMS) now allows geochemists to measure the high-temperature partitioning of isotopes of some of the heavier rock-

Macris, Catherine Amy

2012-01-01T23:59:59.000Z

402

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

SciTech Connect

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

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

2012-07-03T23:59:59.000Z

403

Thermal Gradient Holes At Lightning Dock Area (Cunniff & Bowers, 2005) |  

Open Energy Info (EERE)

Thermal Gradient Holes At Lightning Dock Area Thermal Gradient Holes At Lightning Dock Area (Cunniff & Bowers, 2005) Exploration Activity Details Location Lightning Dock Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness not indicated DOE-funding Unknown Notes The two gradient holes were sited on federal geothermal leases owned by Lightning Dock Geothermal, Inc. and both were drilled into lakebed sediments some distance from the intense shallow geothermal anomaly located in the eastern half of Section 7, Township 25 South, Range 19 West. References Roy A. Cunniff, Roger L. Bowers (2005) Final Technical Report, Geothermal Resource Evaluation And Definitioni (Gred) Program-Phases I, Ii, And Iii For The Animas Valley, Nm Geothermal Resource Retrieved from "http://en.openei.org/w/index.php?title=Thermal_Gradient_Holes_At_Lightning_Dock_Area_(Cunniff_%26_Bowers,_2005)&oldid=387460"

404

[Geothermal resource/reservoir investigations based on heat flow and thermal gradient data for the US]. 6. quarterly technical progress report  

Science Conference Proceedings (OSTI)

During the second quarter of the second year of the contract activity has focused on the task of implementing the exploration well data base. In addition the author has continued to work on the tasks of the maintenance of the WWW site with the heat flow and gradient data base, and development of a modeling capability for analysis of the geothermal system exploration data. He is implementing the data base template for geothermal system temperature-depth/gradient/heat flow data to be used in conjunction with the regional temperature-depth/gradient/heat flow data base that he had already developed. The implementation this quarter has focused on the state of Nevada as the most number of wells are there and few of the wells have been previously available in a data base. A map is enclosed that updates the state of Nevada from the preliminary map in the first quarterly report. They presently are entering data into the geothermal data base. They now have over 1,000 sites in Nevada with data from the sources that they have access to at this time. The breakdown based on the data now entered into the data base is shown in a table.

Blackwell, D.D.

1998-08-18T23:59:59.000Z

405

[Geothermal resource/reservoir investigations based on heat flow and thermal gradient data for the US]. 7. quarterly technical progress report  

Science Conference Proceedings (OSTI)

During the report period, activity has continued to focus on the task of implementing the exploration well data base. In addition the author has continued to work on the tasks of the maintenance of the WWW site with the heat flow and gradient data base, and development of a modeling capability for analysis of the geothermal system exploration data. He is implementing the data base template for geothermal system temperature-depth/gradient/heat flow data to be used in conjunction with the regional temperature-depth/gradient/heat flow data base that he had already developed. Some results of the implementation are included with this report in the form of graphic summaries of the data prepared from the assembled data base. He has continued to enter data into the geothermal data base. The implementation this quarter has continued to focus on the state of Nevada as the most number of wells are there and few of the wells have been previously available in a data base. During this quarter he has maintained the Internet home page illustrating and having available for distribution the regional data base and maps. The address of the page is http://www.smu.edu/{approximately}geothermal/.

Blackwell, D.D.

1998-10-29T23:59:59.000Z

406

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

DOE Green Energy (OSTI)

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.

Fisher, R.

1995-08-01T23:59:59.000Z

407

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

SciTech Connect

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.

Elmore, Richard D.; Engel, Michael H.

2005-03-10T23:59:59.000Z

408

Microbial community structure of hydrothermal deposits from geochemically different vent fields along the Mid-Atlantic Ridge  

Science Conference Proceedings (OSTI)

To evaluate the effects of local fluid geochemistry on microbial communities associated with active hydrothermal vent deposits, we examined the archaeal and bacterial communities of 12 samples collected from two very different vent fields: the basalt-hosted Lucky Strike (37 17'N, 32 16.3'W, depth 1600-1750 m) and the ultramafic-hosted Rainbow (36 13'N, 33 54.1'W, depth 2270-2330 m) vent fields along the Mid-Atlantic Ridge (MAR). Using multiplexed barcoded pyrosequencing of the variable region 4 (V4) of the 16S rRNA genes, we show statistically significant differences between the archaeal and bacterial communities associated with the different vent fields. Quantitative polymerase chain reaction (qPCR) assays of the functional gene diagnostic for methanogenesis (mcrA), as well as geochemical modelling to predict pore fluid chemistries within the deposits, support the pyrosequencing observations. Collectively, these results show that the less reduced, hydrogen-poor fluids at Lucky Strike limit colonization by strict anaerobes such as methanogens, and allow for hyperthermophilic microaerophiles, like Aeropyrum. In contrast, the hydrogen-rich reducing vent fluids at the ultramafic-influenced Rainbow vent field support the prevalence of methanogens and other hydrogen-oxidizing thermophiles at this site. These results demonstrate that biogeographical patterns of hydrothermal vent microorganisms are shaped in part by large scale geological and geochemical processes.

Flores, Gilberto E [Portland State University; Campbell, James H [ORNL; Kirshtein, Julie D [United States Geological Survey, Reston, VA; Meneghin, Jennifer [Portland State University; Podar, Mircea [ORNL; Steinberg, Joshua [Oregon Episcopal School, Portland, OR; Seewald, Jeffrey S [Woods Hole Oceanographic Institution (WHOI), Woods Hole, MA; Tivey, Margaret Kingston [Woods Hole Oceanographic Institution (WHOI), Woods Hole, MA; Voytek, Mary A [United States Geological Survey & National Aeronautics and Space Administration; Reysenbach, Anna-Louise [Portland State University; Yang, Zamin Koo [ORNL

2011-01-01T23:59:59.000Z

409

Stratigraphy and alteration, 15 shallow thermal gradient holes, Roosevelt Hot Springs KGRA and vicinity, Millard and Beaver Counties, Utah  

DOE Green Energy (OSTI)

Fifteen shallow thermal gradient drill holes were recently completed by Geothermal Power Corporation (GPCR) in the vicinity of the Roosevelt Hot Springs KGRA. Five holes penetrated Tertiary granitic rocks and Precambrian gneiss east of the KGRA. Seven holes completed entirely in alluvium near the southwestern corner of the KGRA encountered a near-surface marker horizon of Pleistocene pumice and perlite. Maximum calculated alluvial sedimentation rates since initial deposition of this pumice and perlite range from 1 foot in 12,500 years to 1 foot in 2,300 years. Three holes east of the Mineral Mountains penetrated late Cenozoic basaltic andesite beneath a thin veneer of alluvium. All 15 GPCR drill holes appear to be peripheral to a central zone of anomalously high thermal gradient and low resisitivity delineated by previous investigations. GPCR-8 and -14, however, are characterized by high heat flow and relatively abundant manganese oxide mineralization, which may reflect a favorable hydrologic system controlling thermal fluid flow at depth. These holes thus seem most encouraging for discovery of a deeper high-temperature geothermal resource.

Hulen, J.B.

1978-09-01T23:59:59.000Z

410

Evaluation of low-temperature geothermal potential in north-central Box Elder County, Utah  

DOE Green Energy (OSTI)

The low-temperature geothermal resources of north-central Box Elder County, Utah were assessed. Exploration techniques used included chemical analyses of water from wells and springs, temperature surveys, and temperature-depth measurements in unused wells within the study area. The highest water temperatures (31/sup 0/, 30/sup 0/, and 29/sup 0/C) recorded in this research were located in three separate geographic regions, suggesting that no single warm water occurrence dominates the study area. Total dissolved solid (TDS) concentrations ranged from 294 to 11,590 mg/l. Areas of warm water occurrences generally had TDS values of greater than 1100 mg/l. Reservoir temperatures were estimated using chemical geothermometers. Calculated temperatures ranged between 50/sup 0/ and 100/sup 0/C. Temperature-depth measurements were logged in 16 unused wells. Thermal gradients calculated from the profiles ranged from isothermal to 267/sup 0/C/km. The background gradient for the study area appears to be slightly above the average Basin and Range gradient of 35/sup 0/C/km. The highest gradients were calculated for the area approximately eight kilometers west of Snowville, Utah, which is also an area of warm water. 61 refs., 15 figs., 6 tabs.

Davis, M.C.; Kolesar, P.T.

1984-12-01T23:59:59.000Z

411

Structure formation in the presence of relativistic heat conduction: corrections to the Jeans wave number with a stable first order in the gradients formalism  

E-Print Network (OSTI)

The problem of structure formation in relativistic dissipative fluids was analyzed in a previous work within Eckart's framework, in which the heat flux is coupled to the hydrodynamic acceleration, additional to the usual temperature gradient term. It was shown that in such case, the pathological behavior of fluctuations leads to the disapperance of the gravitational instability responsible for structure formation. In the present work the problem is revisited now using a constitutive equation derived from relativistic kinetic theory. The new relation, in which the heat flux is not coupled to the hydrodynamic acceleration, leads to a consistent first order in the gradients formalism. In this case the gravitational instability remains, and only relativistic corrections to the Jeans wave number are obtained. In the calculation here shown the non-relativistc limit is recovered, opposite to what happens in Eckart's case.

J. H. Mondragon-Suarez; A. Sandoval-Villalbazo; A. L. Garcia-Perciante

2012-01-21T23:59:59.000Z

412

CDIAC Temperature Data Sets  

NLE Websites -- All DOE Office Websites (Extended Search)

Temperature CDIAC Climate Holdings Containing Temperature Data Global Data Sets Data Set Name Investigators Data TypeFormat Period of Record NASA GISS Surface Temperature...

413

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

414

Geochemical Characterization of Chromate Contamination in the 100 Area Vadose Zone at the Hanford Site  

SciTech Connect

The major objectives of the proposed study were to: 1.) determine the leaching characteristics of hexavalent chromium [Cr(VI)] from contaminated sediments collected from 100 Area spill sites; 2.) elucidate possible Cr(VI) mineral and/or chemical associations that may be responsible for Cr(VI) retention in the Hanford Site 100 Areas through the use of i.) macroscopic leaching studies and ii.) microscale characterization of contaminated sediments; and 3.) provide information to construct a conceptual model of Cr(VI) geochemistry in the Hanford 100 Area vadose zone. In addressing these objectives, additional benefits accrued were: (1) a fuller understanding of Cr(VI) entrained in the vadose zone that will that can be utilized in modeling potential Cr(VI) source terms, and (2) accelerating the Columbia River 100 Area corridor cleanup by providing valuable information to develop remedial action based on a fundamental understanding of Cr(VI) vadose zone geochemistry. A series of macroscopic column experiments were conducted with contaminated and uncontaminated sediments to study Cr(VI) desorption patterns in aged and freshly contaminated sediments, evaluate the transport characteristics of dichromate liquid retrieved from old pipelines of the 100 Area; and estimate the effect of strongly reducing liquid on the reduction and transport of Cr(VI). Column experiments used the < 2 mm fraction of the sediment samples and simulated Hanford groundwater solution. Periodic stop-flow events were applied to evaluate the change in elemental concentration during time periods of no flow and greater fluid residence time. The results were fit using a two-site, one dimensional reactive transport model. Sediments were characterized for the spatial and mineralogical associations of the contamination using an array of microscale techniques such as XRD, SEM, EDS, XPS, XMP, and XANES. The following are important conclusions and implications. Results from column experiments indicated that most of contaminant Cr travels fast through the sediments and appears as Cr(VI) in the effluents. The significance of this for groundwater concentrations would, however, depend on the mass flux of recharge to the water table. adsorption of Cr(VI) to sediments from spiked Cr(VI) solution is low; calculated retardation coefficients are close to one. Calcium polysulfide solutions readily reduced Cr(VI) to Cr(III) in column experiments. However a significant amount of the Cr(VI) was mobilized ahead of the polysulfide solution front. This has significant implications for in-situ reductive remediation techniques. The experiments suggest that it would be difficult to design a remedial measure using infiltration of liquid phase reductants without increasing transport of Cr(VI) toward the water table. The microscopic characterization results are consistent with the column studies. Cr(VI) is found as ubiquitous coatings on sediment grain surfaces. Small, higher concentration, chromium sites are associated with secondary clay mineral inclusions, with occasional barium chromate minerals, and reduced to Cr(III) in association with iron oxides that are most likely magnetite primary minerals. Within the restricted access domains of sediment matrix, ferrous iron could also diffuse from in situ, high-surface-area minerals to cause the reductive immobilization of chromate. This process may be favored at microscale geochemical zones where ferrous iron could be supplied. Once nucleated, micrometer-scale precipitates are favored as growing locales for further accumulation, causing the formation of discrete zones of Cr(III).

Dresel, P. Evan; Qafoku, Nikolla; McKinley, James P.; Fruchter, Jonathan S.; Ainsworth, Calvin C.; Liu, Chongxuan; Ilton, Eugene S.; Phillips, J. L.

2008-07-16T23:59:59.000Z

415

Salt effects on isotope partitioning and their geochemical implications: An overview  

DOE Green Energy (OSTI)

Essential to the use of stable isotopes as natural tracers and geothermometers is the knowledge of equilibrium isotope partitioning between different phases and species, which is usually a function of temperature only. The one exception known to date is oxygen and hydrogen isotope fractionation between liquid water and other phases (steam, gases, minerals), which changes upon the addition of salts to water, i.e., the isotope salt salt effect. Our knowledge of this effect, the difference between activity and composition (a-X) of isotopic water molecules in salt solutions, is very limited and controversial, especially at elevated temperatures. For the last several years, we have been conducting a detailed, systematic experimental study at Oak Ridge National Laboratory to determine the isotope salt effects from room temperature to elevated temperatures (currently to 500{degree}C). From this effort, a simple, coherent picture of the isotope salt effect is emerging, that differs markedly from the complex results reported in the literature. In this communication, we present an overview on the isotope salt effect, obtained chiefly from our study. Observed isotope salt effects in salt solutions are significant even at elevated temperatures. The importance and implications of the isotope salt effect for isotopic studies of brine-dominated systems are also discussed in general terms.

Horita, J.; Cole, D.R.; Fortier, S.M. [and others

1996-01-01T23:59:59.000Z

416

The Moana geothermal system in Reno, Nevada: A hydrologic, geochemical, and thermal analysis  

DOE Green Energy (OSTI)

The Moana geothermal systems, located in Reno, Nevada, is a moderate-temperature geothermal resource used for space heating applications. Both historic and new hydrologic, thermal, and groundwater chemistry data were collected to evaluate the Moana system and to develop a calibrated numerical model of the geothermal aquifer for investigation of resource development scenarios. The new data collection consisted of static water level measurements and temperature with depth measurements for a 13-month period at 26 geothermal wells to investigate hydrologic and thermal changes with time. In addition, groundwater chemistry sampling at 10 wells was used to evaluate mixing of thermal and nonthermal waters. Collected information indicates that in the most heavily used portion of the geothermal aquifer, the hydraulic heads have declined. This decline may induce additional leakage of cooler water from the overlying unconfined aquifer and lead to decreased temperatures at well locations in the geothermal aquifer. The groundwater chemistry data show concentration changes with temperature for boron, chloride, fluoride, lithium, and bicarbonate that are a function of the degree of mixing of thermal and nonthermal waters. Temporal changes in these constituents may be used as an indication of relative temperature changes in the geothermal system caused by mixing at a given location. An attempt was made to use the hydraulic head and maximum temperature data to develop a calibrated numerical model for the Moana geothermal system. However, lack of information about the horizontal and vertical thermal and fluid fluxes made the development of a calibrated model not possible at this time. 25 refs., 54 figs., 6 tabs.

Jacobson, E.A.; Johnston, J.W.

1991-03-01T23:59:59.000Z

417

SLAC/CERN High Gradient Tests of An X Band Accelerating Section  

Science Conference Proceedings (OSTI)

High frequency linear collider schemes envisage the use of rather high accelerating gradients: 50 to 100 MV/m for X-band and 80 MV/m for CLIC. Because these gradients are well above those commonly used in accelerators, high gradient studies of high frequency structures have been initiated and test facilities have been constructed at KEK [1], SLAC [2] and CERN [3]. The studies seek to demonstrate that the above mentioned gradients are both achievable and practical. There is no well-defined criterion for the maximum acceptable level of dark current but it must be low enough not to generate unacceptable transverse wakefields, disturb beam position monitor readings or cause RF power losses. Because there are of the order of 10,000 accelerating sections in a high frequency linear collider, the conditioning process should not be too long or difficult. The test facilities have been instrumented to allow investigation of field emission and RF breakdown mechanisms. With an understanding of these effects, the high gradient performance of accelerating sections may be improved through modifications in geometry, fabrication methods and surface finish. These high gradient test facilities also allow the ultimate performance of high frequency/short pulse length accelerating structures to be probed. This report describes the high gradient test at SLAC of an X-band accelerating section built at CERN using technology developed for CLIC.

Loewen, Roderick J

2003-06-13T23:59:59.000Z

418

Potential use of hollow spheres in dual gradient drilling  

E-Print Network (OSTI)

The increasing number of significant deepwater discoveries has pushed the operator and service oil companies to focus their efforts on developing new technologies to drill in deeper water. Dual gradient drilling (DGD) will allow reaching deeper target depths with greater final hole size, which in turn will permit setting larger tubing strings, and hence allowing for higher production rates. DGD can be accomplished by either lifting the mud returns mechanically or diluting the mud returns at the seafloor level by injecting lightweight components. Recently, a novel concept involving the use of hollow spheres in DGD applications has been introduced. In this research, we have evaluated the technical feasibility of using hollow spheres in DGD. We found that hollow spheres have high potential for such an application. They are stable to the drilling fluid additives and components and decrease the density of the drilling mud. The effect on pressure reduction at the seafloor can be significant even when the concentration of spheres injected is smaller than that required to reduce the mud density to seawater density. If the base mud is the carrier fluid, the hollow spheres DGD systems do not require equipment at the seafloor. Additionally, the injection of spheres does not affect the wellbore hydraulics under dynamic conditions. We have identified the constraints for using hollow spheres in DGD. These include particle size of the spheres, collapse of first spheres to be injected at deeper water depths, achieving high concentrations for systems using the mud base as the carrier fluid, and lack of technology to separate the spheres from the mud. In this research, we have developed a friendly, in-house computer program to model features specific to hollow-spheres DGD systems, such as wellbore hydraulics under static and dynamic conditions and the u-tube phenomenon. The results generated by our model match those produced by a field-tested computer program that performs the same task for a similar application. Our findings can be used for further studies of the constraints on the spheres identified in this research, to field test the advantages we predict that hollow spheres will have, and to develop software to fully model hollow-spheres DGD systems.

Vera Vera, Liliana

2002-01-01T23:59:59.000Z

419

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

SciTech Connect

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

Kathy Lu; Christopher Story; W.T. Reynolds

2007-12-21T23:59:59.000Z

420

Geochemical and hydrodynamic controls on arsenic and trace metal cycling in a seasonally stratified US sub-tropical reservoir  

SciTech Connect

The phase distribution of trace metals and oxyanions was investigated within a South Texas watershed hosting a high density of surface uranium mine pits and tailings. The objectives of the study were to evaluate the potential impact of these old uranium mining sites on the watershed with particular emphasis on spatial and temporal changes in water quality of a reservoir that serves as the major source of freshwater to a population of {approx} 350,000 people in the region. A livestock pond, bordered by uranium mine tailings, was used as a model case-study site to evaluate the cycling of uranium mine-derived oxyanions under changing redox conditions. Although the pond showed seasonal thermal and chemical stratification, geochemical cycling of metals was limited to Co and Pb, which seemed to be mostly associated with redox cycling of Mn mineral phases, and U, which suggested reductive precipitation in the ponds hypolimnion. Uranium levels, however, were too low to support strong inputs from th e tailings into the water column of the pond. The strong relations observed between particulate Cr, Cs, V and Fe suggest that these metals are associated with a stable particulate phase (probably allochthonous aluminosilicates) enriched in unreactive iron. This observation is supported by a parallel relationship in sediments collected across a broad range of sediment depositional processed (and histories) in the basin. Arsenic, though selectively enriched in the ponds water column, remained stable and mostly in solution throughout the depth of the profile and showed no sign of geochemical cycling or interaction with Fe-rich particles. We found no evidence of anthropogenic impacts of U mines beyond the purely local scale. Arsenic does decrease in concentration downstream of uranium mining sites but its presence within the Nueces drainage basin is related to interactions between surface and ground waters with uranium-rich geological formations rather than long-scale transport of contaminants downstream of the U mine pits and tailings. As in Lyssy pond, arsenic (and other oxyanions) in Lake Corpus Christi's water column are not affected by the abundant presence of Fe-rich particles but instead behave conservatively throughout the entire period of study. A quantitative mass balance model, constructed using monthly hydrological data for the reservoir, provides quantitative evidence of seasonal evaporative concentration of as in surface waters demonstrating the predominance of hydrodynamic constraints, over geochemical ones, on the cycling of this metal in selected aquatic systems.

Brandenberger, Jill M.; Louchouarn, Patrick; Herbert, Bruce; Tissot, Philippe

2004-10-01T23:59:59.000Z

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


421

Static Temperature Survey At Coso Geothermal Area (1977) | Open Energy  

Open Energy Info (EERE)

Static Temperature Survey At Coso Geothermal Area Static Temperature Survey At Coso Geothermal Area (1977) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Static Temperature Survey Activity Date 1977 Usefulness not indicated DOE-funding Unknown Notes Temperature logs were taken during and after drilling: Results: Convective heat flow and temperatures greater than 350 F appear to occur only along an open fracture system encountered between depths of 1850 and 2775 feet. Temperature logs indicate a negative thermal gradient below 3000 feet. Water chemistry indicates that this geothermal resource is a hot-water rather than a vapor-dominated system. References Galbraith, R. M. (1 May 1978) Geological and geophysical analysis of Coso Geothermal Exploration Hole No. 1 (CGEH-1), Coso Hot Springs KGRA,

422

Thermal Gradient Holes At Blue Mountain Area (Fairbank & Neggemann, 2004) |  

Open Energy Info (EERE)

Blue Mountain Area (Fairbank & Neggemann, 2004) Blue Mountain Area (Fairbank & Neggemann, 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Blue Mountain Area (Fairbank & Neggemann, 2004) Exploration Activity Details Location Blue Mountain Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness useful DOE-funding Unknown References Brian D. Fairbank, Kim V. Niggemann (2004) Deep Blue No 1- A Slimhole Geothermal Discovery At Blue Mountain, Humboldt County, Nevada Retrieved from "http://en.openei.org/w/index.php?title=Thermal_Gradient_Holes_At_Blue_Mountain_Area_(Fairbank_%26_Neggemann,_2004)&oldid=386709" Category: Exploration Activities What links here Related changes Special pages Printable version Permanent link

423

Using Cepheids to determine the galactic abundance gradient II. Towards the galactic center  

E-Print Network (OSTI)

Based on spectra obtained at the Anglo-Australian Observatory, we present a discussion of the metallicity of the galactic disc derived using Cepheids at galactocentric distances 4-6 kpc. Our new results together with previous gradient determination (Paper I) show that the overall abundance distribution within the galactocentric distances 4-11 kpc cannot by represented by a single gradient value. The distribution is more likely bimodal: it is flatter in the solar neighbourhood with a small gradient, and steepens towards the galactic center. The steepening begins at a distance of about 6.6 kpc.

S. M. Andrievsky; D. Bersier; V. V. Kovtyukh; R. E. Luck; W. J. Maciel; J. R. D. Lepine; Yu. V. Beletsky

2001-12-21T23:59:59.000Z

424

The Key Role of the Western Boundary in Linking the AMOC Strength to the North–South Pressure Gradient  

Science Conference Proceedings (OSTI)

A key idea in the study of the Atlantic meridional overturning circulation (AMOC) is that its strength is proportional to the meridional density gradient or, more precisely, to the strength of the meridional pressure gradient. A physical basis ...

Willem P. Sijp; Jonathan M. Gregory; Remi Tailleux; Paul Spence

2012-04-01T23:59:59.000Z

425

Search for a Critical Electron Temperature Gradient in DIII-D L-Mode Discharges (A24846)  

E-Print Network (OSTI)

Proc. Of 20th IAEA Fusion Energy Conf., Vilamoura, Portugal, 2004, To Be Published On Website20th IAEA Fusion Energy Conference Vilamoura, PT, 2004999610250

DeBoo, J.C.

2004-10-13T23:59:59.000Z

426

Experimental study of layer mixing, relative ionic escape velocity, and electron temperature gradients in spherical multilayered targets by XUV spectroscopy  

SciTech Connect

This past year we have undertaken experiments at the University of Rochester's Laboratory for Laser Energetics investigating layer mixing and expansion velocities of spherical targets uniformly irradiated by high intensity laser light. We performed high resolution spectroscopic measurements of spherical plasmas, produced using the Omega laser, and have observed enhanced broadening of XUV emission lines due to the expansion velocities.

Griem, H.R.

1990-07-01T23:59:59.000Z

427

Observation of a Critical Gradient Threshold for Electron Temperature Fluctuations in the DIII-D Tokamak (A27336)  

E-Print Network (OSTI)

Proceedings Of 39th European Physical Society Conference On Plasma Physics, Stockholm, Sweden, 2012; Http://ocs.ciemat.es/epsicpp2012pap/html/author.html. P5.045.pdf39th EPS Conference on Controlled Fusion and Plasma Physics Stockholm, SE, 2012999619101

Hillesheim, J.C.

2012-06-21T23:59:59.000Z

428

TOUGHREACT-A simulation program for non-isothermal multiphase reactive geochemical transport in variably saturated geologic media: Applications to geothermal injectivity and CO2 geological sequestration  

Science Conference Proceedings (OSTI)

TOUGHREACT is a numerical simulation program for chemically reactive non-isothermal flows of multiphase fluids in porous and fractured media. The program was written in Fortran 77 and developed by introducing reactive geochemistry into the multiphase ... Keywords: CO2 geologic sequestration, Clay swelling, Geochemical transport, Hydrothermal systems, Injectivity enhancement, Mineral scaling, Mineral trapping, Reactive fluid flow, Saline aquifer, TOUGHREACT

Tianfu Xu; Eric Sonnenthal; Nicolas Spycher; Karsten Pruess

2006-03-01T23:59:59.000Z

429

The global geochemical cycles of iron and calcium: using novel isotope systems to understand weathering, global mass budgets, natural reaction rates, and paleoclimate  

E-Print Network (OSTI)

in the sedimentary column, and diagenetic alteration of Ca isotope signals over geologic time scales. The overallThe global geochemical cycles of iron and calcium: using novel isotope systems to understand of Doctor of Philosophy in Geology in the GRADUATE DIVISION of the UNIVERSITY OF CALIFORNIA, BERKELEY

Fantle, Matthew

430

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

Science Conference Proceedings (OSTI)

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.

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

2011-05-01T23:59:59.000Z

431

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

Science Conference Proceedings (OSTI)

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.

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

2012-02-01T23:59:59.000Z

432

Thermal Gradient Holes At Kilauea East Rift Area (Thomas, 1986) | Open  

Open Energy Info (EERE)

Thermal Gradient Holes At Kilauea East Rift Area (Thomas, 1986) Thermal Gradient Holes At Kilauea East Rift Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Kilauea East Rift Area (Thomas, 1986) Exploration Activity Details Location Kilauea East Rift Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness useful DOE-funding Unknown Notes Two separate phases of geothermal exploratory drilling have occurred on the lower East Rift. The first was essentially a wildcat venture with relatively little surface exploratory data having been gathered, whereas the second was initiated after somewhat more geoscience information had been acquired under the Hawaii Geothermal Project. The results of the successful exploratory drilling program on the Kilauea

433

Thermal Gradient Holes At Kilauea Summit Area (Keller, Et Al., 1979) | Open  

Open Energy Info (EERE)

Thermal Gradient Holes At Kilauea Summit Area (Keller, Et Al., 1979) Thermal Gradient Holes At Kilauea Summit Area (Keller, Et Al., 1979) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Kilauea Summit Area (Keller, Et Al., 1979) Exploration Activity Details Location Kilauea Summit Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness useful DOE-funding Unknown Notes A deep borehole was drilled at the summit of Kilauea volcano, Hawaii, between April 6 and July 9, 1973. The hole is located approximately 1 km south of the edge of Halemaumau crater (Figs. 1 and 2), a crater within the summit caldera of the volcano. The total depth of the hole is 1262 m (4141 ft) measured from the derrick floor at an altitude of 1102 m (3616 ft). A description of the drilling program and some of the results obtained have

434

Thermal Gradient Holes At Crump's Hot Springs Area (DOE GTP) | Open Energy  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Thermal Gradient Holes At Crump's Hot Springs Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Crump's Hot Springs Area (DOE GTP) Exploration Activity Details Location Crump's Hot Springs Geothermal Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness not indicated DOE-funding Unknown Notes 8 wells References (1 January 2011) GTP ARRA Spreadsheet Retrieved from "http://en.openei.org/w/index.php?title=Thermal_Gradient_Holes_At_Crump%27s_Hot_Springs_Area_(DOE_GTP)&oldid=402699"

435

A General Pressure Gradient Formulation for Ocean Models. Part I: Scheme Design and Diagnostic Analysis  

Science Conference Proceedings (OSTI)

A Jacobian formulation of the pressure gradient force for use in models with topography-following coordinates is proposed. It can be used in conjunction with any vertical coordinate system and is easily implemented. Vertical variations in the ...

Y. Tony Song

1998-12-01T23:59:59.000Z

436

Conjugate-Gradient Methods for Large-Scale Minimization in Meteorology  

Science Conference Proceedings (OSTI)

During the last few years new meteorological variational analysis methods have evolved, requiring large-scale minimization of a nonlinear objective function described in terms of discrete variables. The conjugate-gradient method was found to ...

I. M. Navon; David M. Legler

1987-08-01T23:59:59.000Z

437

Exploring Self-Correlation in Flux–Gradient Relationships for Stably Stratified Conditions  

Science Conference Proceedings (OSTI)

In this paper, the degree of scatter in flux–gradient relationships for stably stratified conditions is analyzed. It is generally found that scatter in the dimensionless lapse rate h is larger than in the dimensionless shear m when plotted ...

P. Baas; G. J. Steeneveld; B. J. H. van de Wiel; A. A. M. Holtslag

2006-11-01T23:59:59.000Z

438

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

SciTech Connect

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

Amendt, P

2005-12-20T23:59:59.000Z

439

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

SciTech Connect

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

Amendt, Peter [Lawrence Livermore National Laboratory, University of California, Livermore, California 94551 (United States)

2006-04-15T23:59:59.000Z

440

Thermal Gradient Holes At Northern Basin & Range Region (Pritchett, 2004) |  

Open Energy Info (EERE)

Gradient Holes At Northern Basin & Range Region (Pritchett, 2004) Gradient Holes At Northern Basin & Range Region (Pritchett, 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Northern Basin & Range Region (Pritchett, 2004) Exploration Activity Details Location Northern Basin and Range Geothermal Region Exploration Technique Thermal Gradient Holes Activity Date Usefulness not useful DOE-funding Unknown Notes NOTE: These are theoretical/computer simulation tests of various methods on eight hypothetical 'model' basing-and-range geothermal systems. "The 300-meter heat flow holes are essentially useless for finding the "hidden" reservoirs. Clearly, the best results are obtained from the SP and MT surveys, with DC resistivity a close third. It is concluded that the best

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


441

Impact of Density Gradients on Net Sediment Transport into the Wadden Sea  

Science Conference Proceedings (OSTI)

This study tests the hypothesis that horizontal density gradients have the potential to significantly contribute to the accumulation of suspended particulate matter (SPM) in the Wadden Sea. It is shown by means of long-term observations at ...

Hans Burchard; Götz Flöser; Joanna V. Staneva; Thomas H. Badewien; Rolf Riethmüller

2008-03-01T23:59:59.000Z

442

Using Cepheids to determine the galactic abundance gradient I. The solar neighbourhood  

E-Print Network (OSTI)

A number of studies of abundance gradients in the galactic disk have been performed in recent years. The results obtained are rather disparate: from no detectable gradient to a rather significant slope of about -0.1 dex kpc -1. The present study concerns the abundance gradient based on the spectroscopic analysis of a sample of classical Cepheids. These stars enable one to obtain reliable abundances of a variety of chemical elements. Additionally, they have well determined distances which allow an accurate determination of abundance distributions in the galactic disc. Using 236 high resolution spectra of 77 galactic Cepheids, the radial elemental distribution in the galactic disc between galactocentric distances in the range 6-11 kpc has been investigated. Gradients for 25 chemical elements (from carbon to gadolinium) are derived...

S. M. Andrievsky; V. V. Kovtyukh; R. E. Luck; J. R. D. Lepine; D. Bersier; W. J. Maciel; B. Barbuy; V. G. Klochkova; V. E. Panchuk; R. U. Karpischek

2001-12-21T23:59:59.000Z

443

Relationships between Barrier Jet Heights, Orographic Precipitation Gradients, and Streamflow in the Northern Sierra Nevada  

Science Conference Proceedings (OSTI)

The rate of precipitation increase with elevation, termed the orographic precipitation gradient (OPG), is critically important for hydrologic forecasting in mountain basins that receive both rain and snow. Here, the following are examined to see ...

Jessica D. Lundquist; Justin R. Minder; Paul J. Neiman; Ellen Sukovich

2010-10-01T23:59:59.000Z

444

The Advection–Diffusion Problem for Stratospheric Flow. Part II: Probability Distribution Function of Tracer Gradients  

Science Conference Proceedings (OSTI)

This paper is a continuation of the study of the advection–diffusion problem for stratospheric flow, and deals with the probability distribution function (PDF) of gradients of a freely decaying passive tracer. Theoretical arguments are reviewed ...

Yongyun Hu; Raymond T. Pierrehumbert

2002-10-01T23:59:59.000Z

445

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

E-Print Network (OSTI)

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

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

2013-01-01T23:59:59.000Z

446

An Improved Technique for Computing the Horizontal Pressure-Gradient Force at the Earth's Surface  

Science Conference Proceedings (OSTI)

On conventional surface analyses, sea level isobars allow a forecaster to compute the horizontal pressure-gradient force at sea level, which for much of the world is fairly close to the earth's surface. However, over elevated terrain the ...

Wayne E. Sangster

1987-07-01T23:59:59.000Z

447

The Continuous Spectrum in Baroclinic Models with Uniform Potential Vorticity Gradient and Ekman Damping  

Science Conference Proceedings (OSTI)

Analytic solutions of the continuous spectrum are obtained for quasigeostrophic models in which the basic-state meridional potential vorticity (PV) gradient is uniform but nonzero. The modes that form the continuous spectrum—continuum modes—are ...

Hylke de Vries

2009-09-01T23:59:59.000Z

448

Acceleration of a Stratified Current over a Sloping Bottom, Driven by an Alongshelf Pressure Gradient  

Science Conference Proceedings (OSTI)

An idealized theoretical model is developed for the acceleration of a two-dimensional, stratified current over a uniformly sloping bottom, driven by an imposed alongshelf pressure gradient and taking into account the effects of buoyancy advection ...

David C. Chapman; Steven J. Lentz

2005-08-01T23:59:59.000Z

449

Small-Scale Spatial Gradients in Climatological Precipitation on the Olympic Peninsula  

Science Conference Proceedings (OSTI)

Persistent, 10-km-scale gradients in climatological precipitation tied to topography are documented with a finescale rain and snow gauge network in the Matheny Ridge area of the Olympic Mountains of Washington State. Precipitation totals are 50% ...

Alison M. Anders; Gerard H. Roe; Dale R. Durran; Justin R. Minder

2007-10-01T23:59:59.000Z

450

Horizontal Surface Tension Gradients Induced in Monolayers by Gravity Water Wave Action  

Science Conference Proceedings (OSTI)

Surface tension gradients have been measured for three different monolayers (oleyl alcohol, palmitic acid methyl ester and cetyl trimethyl ammonium bromide) spread on a wavy water surface (waves with 1-Hz frequency; 2 cm wave height). The wave-...

Philipp A. Lange; Heinrich Hühnerfuss

1984-10-01T23:59:59.000Z

451

Thermal Gradient Holes At Twenty-Nine Palms Area (Page, Et Al., 2010) |  

Open Energy Info (EERE)

Thermal Gradient Holes At Twenty-Nine Palms Thermal Gradient Holes At Twenty-Nine Palms Geothermal Area (Page, Et Al., 2010) Exploration Activity Details Location Twenty-Nine Palms Geothermal Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness useful DOE-funding Unknown Notes From November 2008 to March 2009, Seabees from the Naval Construction Division (NCD) successfully completed fivetemperature gradient holes for the GPO. Samples taken from each hole were similar in nature; mixtures of sand and conglomerates with the occasional granite sections were typically encountered. Each hole varied slightly in depth, ranging from 600ft to 1,000ft; however, each hole has been completed to acceptable standards of the GPO. Upon completion of drilling, 3" metal tubing was inserted to

452

Thermal Gradient Holes At Twenty-Nine Palms Area (Sabin, Et Al., 2010) |  

Open Energy Info (EERE)

Thermal Gradient Holes At Twenty-Nine Palms Area (Sabin, Et Al., 2010) Thermal Gradient Holes At Twenty-Nine Palms Area (Sabin, Et Al., 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Twenty-Nine Palms Geothermal Area (Sabin, Et Al., 2010) Exploration Activity Details Location Twenty-Nine Palms Geothermal Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness useful DOE-funding Unknown Notes The first and only Seabee drilling project was the installation of five TGHs at the Camp Wilson region of the MCAGCC Marine base near Twenty-Nine Palms, CA. While the program was a success and GPO identified an anomaly where a deep, slim hole is to be drilled in June, 2010, the Seabee rig was sent oversees soon after drilling was completed. If/when another rig

453

Thermal Gradient Holes At Fish Lake Valley Area (DOE GTP) | Open Energy  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Thermal Gradient Holes At Fish Lake Valley Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Fish Lake Valley Area (DOE GTP) Exploration Activity Details Location Fish Lake Valley Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness not indicated DOE-funding Unknown Notes 2 wells References (1 January 2011) GTP ARRA Spreadsheet Retrieved from "http://en.openei.org/w/index.php?title=Thermal_Gradient_Holes_At_Fish_Lake_Valley_Area_(DOE_GTP)&oldid=511222" Categories:

454

Thermal Gradient Holes At Nw Basin & Range Region (Pritchett, 2004) | Open  

Open Energy Info (EERE)

Thermal Gradient Holes At Nw Basin & Range Region (Pritchett, 2004) Thermal Gradient Holes At Nw Basin & Range Region (Pritchett, 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Nw Basin & Range Region (Pritchett, 2004) Exploration Activity Details Location Northwest Basin and Range Geothermal Region Exploration Technique Thermal Gradient Holes Activity Date Usefulness not useful DOE-funding Unknown Notes NOTE: These are theoretical/computer simulation tests of various methods on eight hypothetical 'model' basing-and-range geothermal systems. "The 300-meter heat flow holes are essentially useless for finding the "hidden" reservoirs. Clearly, the best results are obtained from the SP and MT surveys, with DC resistivity a close third. It is concluded that the best

455

The Relationships among Wind, Horizontal Pressure Gradient, and Turbulent Momentum Transport during CASES-99  

Science Conference Proceedings (OSTI)

Relationships among the horizontal pressure gradient, the Coriolis force, and the vertical momentum transport by turbulent fluxes are investigated using data collected from the Cooperative Atmosphere-Surface Exchange Study in 1999 (CASES99). Wind ...

Jielun Sun; Donald H. Lenschow; Larry Mahrt; Carmen Nappo

456

Salt effects on stable isotope partitioning and their geochemical implications for geothermal brines  

DOE Green Energy (OSTI)

It has long been recognized that dissolved salts in water can change oxygen and hydrogen isotope partitioning between water and other phases (i.e., vapor, minerals) due to the hydration of ions upon the dissolution of salts in water. However, their effects have not been well determined at elevated temperatures. We are currently conducting a series of hydrothermal experiments of the system brine-vapor or minerals to 350{degrees}C, in order to determine precisely the effects of dissolved salts abundant in brines on isotope partitioning at temperatures encountered in geothermal systems. The so-called ``isotope salt effect`` has important implications for the interpretation and modeling of isotopic data of brines and rocks obtained from geothermal fields. We will show how to use our new results of isotopic partitioning to help better evaluate energy resources of many geothermal fields.

Horita, J.; Cole, D.R.; Wesolowski, D.J.

1994-06-01T23:59:59.000Z

457

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

SciTech Connect

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

Sorrentino, F.; Lien, Y.-H.; Rosi, G.; Tino, G. M. [Dipartimento di Fisica e Astronomia and LENS, Universita di Firenze, INFN Sezione di Firenze, via Sansone 1, I-50019 Sesto Fiorentino (Italy); Bertoldi, A. [Laboratoire Charles Fabry de l'Institut d'Optique, CNRS and Universite Paris-Sud Campus Polytechnique, RD 128, F-91127 Palaiseau cedex (France); Bodart, Q. [Dipartimento di Fisica e Astronomia and LENS, Universita di Firenze, INFN Sezione di Firenze, via Sansone 1, I-50019 Sesto Fiorentino (Italy); European Space Agency, Research and Scientific Support Department, Keplerlaan 1, 2201 AZ Noordwijk (Netherlands); Cacciapuoti, L. [European Space Agency, Research and Scientific Support Department, Keplerlaan 1, 2201 AZ Noordwijk (Netherlands); Angelis, M. de [Istituto di Fisica Applicata 'Nello Carrara' CNR, via Madonna del Piano 10, I-50019 Sesto Fiorentino (Italy); Prevedelli, M. [Dipartimento di Fisica dell'Universita di Bologna, Via Irnerio 46, I-40126, Bologna (Italy)

2012-09-10T23:59:59.000Z

458

Measuring the Casimir force gradient from graphene on a SiO_2 substrate  

E-Print Network (OSTI)

The gradient of the Casimir force between a Si-SiO${}_2$-graphene substrate and an Au-coated sphere is measured by means of a dynamic atomic force microscope operated in the frequency shift technique. It is shown that the presence of graphene leads to up to 9% increase in the force gradient at the shortest separation considered. This is in qualitative agreement with the predictions of an additive theory using the Dirac model of graphene.

A. A. Banishev; H. Wen; J. Xu; R. K. Kawakami; G. L. Klimchitskaya; V. M. Mostepanenko; U. Mohideen

2013-01-28T23:59:59.000Z

459

Results of the 1988 geothermal gradient test drilling project for the State of Washington  

SciTech Connect

During late summer and early fall of 1988, the Washington Department of Natural Resources, Division of Geology and Earth Resources (DGER) completed drilling eight shallow geothermal gradient test wells in the southern Washington Cascade Range. This report describes the preliminary results of the 1988 drilling and gradient measuring, and summarizes our current perspectives on distribution and magnitude of the geothermal resource potential in the southern Washington Cascades. 18 refs., 11 figs., 11 tabs.

Barnett, D.B.; Korosec, M.A.

1989-05-01T23:59:59.000Z

460

Density gradient free electron collisionally excited x-ray laser  

DOE Patents (OSTI)

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

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

1984-11-29T23:59:59.000Z

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