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1

large map to ther sections  

E-Print Network (OSTI)

intersection at Coolidge and Hagar drives. · After Coolidge makes a sweeping left turn it becomes McLaughlin Dr the Stevenson College driveway and across McLaughlin and look for the stone steps leading to the Garden entrance. Use caution crossing McLaughlin and on the steps, which can be slippery. · Come on in. Welcome

California at Santa Cruz, University of

2

Distributed Energy Harvesting for Energy Neutral Sensor Networks  

E-Print Network (OSTI)

adja@cs.berkeley.edu Energy Harvesting Projects EDITORSdevices that combine energy harvesting and data acquisition.kinetic and ther- mal energy harvesting from human users

Kansal, Aman; Srivastava, Mani B.

2005-01-01T23:59:59.000Z

3

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...

4

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

5

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

6

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

7

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

8

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

9

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...

10

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.

11

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

12

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. ...

13

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

14

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

15

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.

16

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

17

TherML: occupancy prediction for thermostat control  

Science Conference Proceedings (OSTI)

Reducing the large energy consumption of temperature regulation systems is a challenge for researchers and practitioners alike. In this paper, we explore and compare two common types of solutions: A manual systems that encourages reduced energy use, ... Keywords: energy, heating, location, machine learning, prediction

Christian Koehler, Brian D. Ziebart, Jennifer Mankoff, Anind K. Dey

2013-09-01T23:59:59.000Z

18

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...

19

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

20

Section 4.1 Integrated Building Design: Greening Federal Facilities...  

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

1.1 Passive Solar Design in occupied spaces and thermal mass to smooth out temperature fluctuations. A Trombe wall puts the ther- mal mass (e.g., tile floors) directly behind the...

Note: This page contains sample records for the topic "ther mal gradients" 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

Appl. Phys. 18, 271 274 (1979) 9 bySpringer-Verlag1979  

E-Print Network (OSTI)

in thermally depoled La-doped lead zirconate titanate (PLZT) ceramics of composition 8/65/35 and 9/65/35 has on temperature-dependent optical second-harmonic generation (SHG) in ther- mally depoled samples, mainly performed at room temperature, by incomplete ther- mal depoling of the sample and by internal strain. 1

Osnabrück, Universität

22

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...

23

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

24

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

25

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

26

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

27

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

28

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

29

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

30

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

31

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

32

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

33

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

34

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

35

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

36

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

37

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

38

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

39

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

40

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

Note: This page contains sample records for the topic "ther mal gradients" 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

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

42

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 WTGthat vertical velocity ...

David M. Romps

2012-09-01T23:59:59.000Z

43

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

44

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

45

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

46

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

47

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...

48

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

49

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

50

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

51

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.

52

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"

53

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.

54

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.

55

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)

56

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)...

57

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...

58

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...

59

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...

60

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...

Note: This page contains sample records for the topic "ther mal gradients" 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

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...

62

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...

63

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...

64

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...

65

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...

66

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...

67

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...

68

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...

69

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...

70

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)...

71

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

72

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

73

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

74

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

75

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)

76

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

77

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

78

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 Gnther; Michael Peardon

2013-12-11T23:59:59.000Z

79

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

80

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

Note: This page contains sample records for the topic "ther mal gradients" 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

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...

82

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

83

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

84

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

85

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

86

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

87

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

88

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...

89

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

90

Asymmetric Tidal Mixing due to the Horizontal Density Gradient  

Science Conference Proceedings (OSTI)

Stratification and turbulent mixing exhibit a floodebb 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

91

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 Bon; Hubert Cardot

2005-09-01T23:59:59.000Z

92

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

93

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...

94

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

95

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

96

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

97

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

98

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,

99

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

100

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

Note: This page contains sample records for the topic "ther mal gradients" 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

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

102

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

103

COLLOQUE SUR L'APPLICATION INDUSTRIELLE DE LA THERMODYNAMIQUE MOLECULAIRE (InMoTher)  

E-Print Network (OSTI)

with the goal of understanding the atom. probably its first success was to compute accurately the ground state result in this direction was the creation of Thomas­Fermi (TF) theory. They attempted to understand atoms

104

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

105

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

106

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

107

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

108

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

109

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

110

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

E-Print Network (OSTI)

the decision variable and use incremental gradient methods that operate upon ... P : Rnrnc ? 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.

111

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

112

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

113

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), 9891000. ... estimation in multivariate linear regression, Journal of the Royal Statistical Society:.

114

Mechanical engineering Department Seminar  

E-Print Network (OSTI)

power generation gas turbines and jet engines. As the energy efficiency of gas turbines in- creases to pro- vide thermal protection to turbine blades and vanes in the hottest sections of both electric with turbine inlet turbine, advances in turbine efficiency depend on improved ther- mal barrier coatings

115

Effective thermal conductivity of rough spherical packed beds Majid Bahrami *, M. Michael Yovanovich, J. Richard Culham  

E-Print Network (OSTI)

relationships. The present model accounts for the thermophysical properties of spheres and the gas, load-dimensional numerical analysis which makes the FEM modeling extremely expen- sive from the calculative point of view [3]. In addition, ther- mal contact resistance (TCR) of rough spheres must be fed into the software as boundary

Bahrami, Majid

116

860 IEEE TRANSACTIONS ON COMPUTER-AIDED DESIGN OF INTEGRATED CIRCUITS AND SYSTEMS, VOL. 28, NO. 6, JUNE 2009 Multiscale Thermal Analysis for Nanometer-Scale  

E-Print Network (OSTI)

of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, CO 80309 USA (e-mail: li power densities are making this problem more important. Characterizing the thermal profile of an IC in software and used for the full-chip ther- mal analysis and temperature-dependent leakage analysis of an IC

Dick, Robert

117

FUELING THE FUTURE: Meeting Pakistan's Energy Needs in the 21st Century  

E-Print Network (OSTI)

controversy and provincial disagreements associated with storage-based hydroelec- tric power generation of the industries and ther- mal power generating units in the country, and includes 9,060 km of high pressure percent is oil. Nuclear energy accounts for only 3 percent of power generation. Current installed capacity

Vermont, University of

118

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 Lscher

2013-02-21T23:59:59.000Z

119

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

120

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 "ther mal gradients" 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

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

122

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

123

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

124

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

125

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

126

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

127

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

128

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

129

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

130

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

131

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

132

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

133

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

134

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

135

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

136

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

137

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

138

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

139

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

140

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

Note: This page contains sample records for the topic "ther mal gradients" 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

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

142

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

143

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

144

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

145

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

146

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

147

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

148

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

149

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

150

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

151

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

152

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.

153

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

154

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

155

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

156

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

157

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

158

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...

159

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...

160

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...

Note: This page contains sample records for the topic "ther mal gradients" from the National Library of EnergyBeta (NLEBeta).
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161

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...

162

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

163

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...

164

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

165

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

166

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

167

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

168

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

169

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

170

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

171

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

172

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

173

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

174

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

175

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

176

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

177

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"

178

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

179

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

180

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

Note: This page contains sample records for the topic "ther mal gradients" 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

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

182

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

183

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

184

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

185

The Key Role of the Western Boundary in Linking the AMOC Strength to the NorthSouth 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

186

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

187

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

188

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"

189

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

190

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

191

Exploring Self-Correlation in FluxGradient Relationships for Stably Stratified Conditions  

Science Conference Proceedings (OSTI)

In this paper, the degree of scatter in fluxgradient 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

192

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

193

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

194

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

195

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

196

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; Gtz Flser; Joanna V. Staneva; Thomas H. Badewien; Rolf Riethmller

2008-03-01T23:59:59.000Z

197

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

198

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

199

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.

200

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

Note: This page contains sample records for the topic "ther mal gradients" 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 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...

202

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

203

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

204

The AdvectionDiffusion 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 advectiondiffusion 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

205

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

206

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

207

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

208

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

209

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

210

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

211

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 spectrumcontinuum modesare ...

Hylke de Vries

2009-09-01T23:59:59.000Z

212

Reorganization of Tropical Climate during El Nio: 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 NioSouthern 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

213

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

214

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

215

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 Hhnerfuss

1984-10-01T23:59:59.000Z

216

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

Science Conference Proceedings (OSTI)

Evidence for the radiometric determination of airwater 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

217

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

218

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

219

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

220

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:

Note: This page contains sample records for the topic "ther mal gradients" 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 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.

222

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

223

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

224

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

225

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

226

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

227

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

228

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

229

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

230

A Unifying Approach to Quaternion Adaptive Filtering: Addressing the Gradient and Convergence  

E-Print Network (OSTI)

A novel framework for a unifying treatment of quaternion valued adaptive filtering algorithms is introduced. This is achieved based on a rigorous account of quaternion differentiability, the proposed I-gradient, and the use of augmented quaternion statistics to account for real world data with noncircular probability distributions. We first provide an elegant solution for the calculation of the gradient of real functions of quaternion variables (typical cost function), an issue that has so far prevented systematic development of quaternion adaptive filters. This makes it possible to unify the class of existing and proposed quaternion least mean square (QLMS) algorithms, and to illuminate their structural similarity. Next, in order to cater for both circular and noncircular data, the class of widely linear QLMS (WL-QLMS) algorithms is introduced and the subsequent convergence analysis unifies the treatment of strictly linear and widely linear filters, for both proper and improper sources. It is also shown that the proposed class of HR gradients allows us to resolve the uncertainty owing to the noncommutativity of quaternion products, while the involution gradient (I-gradient) provides generic extensions of the corresponding real- and complex-valued adaptive algorithms, at a reduced computational cost. Simulations in both the strictly linear and widely linear setting support the approach.

Cyrus Jahanchahi; Danilo P. Mandic

2013-10-17T23:59:59.000Z

231

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

232

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

233

Efficiency of caviton formation as a function of plasma density gradient  

SciTech Connect

The effect of a zeroth-order density gradient on the development of cavitons has been investigated experimentally and numerically. The cavitons were produced via excitation of electron plasma waves (EPW) with a modest ({ital E}{sup 2}/4{pi}{ital nT}{sub {ital e}}{much lt}1) resonant radio-frequency pump. The location of the resonance, on an inverse-parabolic density profile, was varied, with all other parameters being held constant. The depth of the caviton, and the strength of its associated trapped electric fields, are found to depend strongly on the density gradient scale length at the critical layer, with a maximum occurring when this length is infinite, at the flat top of the density profile. The results are accounted for by the dependence on the density gradient of the EPW convection rate and wave-breaking time. The study helps illuminate recent large-scale ionospheric density modification experiments.

Bauer, B.S.; Wong, A.Y.; Scurry, L.; Decyk, V.K. (Department of Physics, University of California, Los Angeles, Los Angeles, California 90024 (USA))

1990-08-01T23:59:59.000Z

234

Experimental and theoretical investigation of high gradient acceleration. Progress report, June 1, 1991--February 1, 1992  

SciTech Connect

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

235

Collisionless absorption of light waves incident on overdense plasmas with steep density gradients  

Science Conference Proceedings (OSTI)

Collisionless absorption of laser light incident on overdense plasmas with steep density gradients is studied analytically and numerically. For the normal incidence case, it is shown that both sheath inverse bremsstrahlung and the anomalous skin effect are limiting cases of the same collisionless absorption mechanism. Using particle-in-cell (PIC) plasma simulations, the effects of finite sheath-transit time and finite density gradient are investigated. The analyses are extended to oblique incident cases. For p-polarized obliquely incident light, the results are significantly different from those for the normal incidence case. Most noticeable is the absorption enhancement for the p-polarized light due to the interaction of the electrons with the normal (parallel to the density gradient) component of the laser electric field in the sheath region.

Yang, T.Y.B.; Kruer, W.L.; Langdon, A.B.

1995-07-31T23:59:59.000Z

236

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

E-Print Network (OSTI)

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

Jan Harms; Riccardo DeSalvo; Steven Dorsher; Vuk Mandic

2009-10-15T23:59:59.000Z

237

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

238

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

Open Energy Info (EERE)

Thermal Gradient Holes At Chocolate Mountains Area Thermal Gradient Holes At Chocolate Mountains Area (Sabin, Et Al., 2010) Exploration Activity Details Location Chocolate Mountains Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness not indicated DOE-funding Unknown Notes In lieu of Seabee TGH drilling, GPO awarded a large IDIQ TGH drilling contract in December, 2009. Over the next two years, 90 500-ft TGHs will be installed at select sites in California and Nevada. Interim data from this campaign are already available for the Chocolate Mountains and Hawthorne. Results of these programs can be found in the Chocolate Mountains and Hawthorne papers also available in this volume. References Andrew Sabin, S. Bjornstad, M. Lazaro, D. Meade, C. Page, S. Alm, A. Tiedeman, W. C. Huang (2010) Navy's Geothermal Program Office: Overview

239

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

240

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

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241

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

242

HYDROGEN REDISTRIBUTION IN THIN PLATES OF ZIRCONIUM UNDER LARGE THERMAL GRADIENTS  

DOE Green Energy (OSTI)

By using experimental data, the quantities determimng the extent of dissolved H redistribution under a thermal gradient in Zircaloy were calculated. It is concluded that the phenomenon of hydride precipitation by means of thermaI gradient diffusion of dissolved H in Zircaloy fuel plates and cladding places much more severe restrictions on the allowable pre-operation H content of such elements than was hitherto suspected. The specific effects of operating conditions on H content of plates and cladding are presented in detail. (M. H.R.)

Markowitz, J.M.

1958-01-01T23:59:59.000Z

243

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

244

Refractive index gradient measurement across the thickness of a dielectric film by the prism coupling method  

Science Conference Proceedings (OSTI)

A method is proposed for measuring the refractive index gradient n(z) in nonuniformly thick dielectric films. The method is based on the excitation of waveguide modes in a film using the prism coupling technique and on the calculation of n(z) and film thickness H{sub f} with the help of the angular positions of the TE or TM modes. The method can be used for an arbitrary shape of the index modulation over the film thickness in the limit of a small gradient [{Delta} n(z)/n(z) || 1]. (laser applications and other topics in quantum electronics)

Sokolov, Viktor I; Panchenko, Vladislav Ya; Seminogov, V N [Institute of Laser and Information Technologies, Russian Academy of Sciences, Troitsk, Moscow Region (Russian Federation)

2012-08-31T23:59:59.000Z

245

Clackamas 4800-foot thermal gradient hole: Cascade geothermal drilling: Final technical report  

Science Conference Proceedings (OSTI)

Thermal Power Company (Thermal) completed a thermal gradient hole to about 5000 feet (1524 m) total depth in Section 28, Township 8 South, Range 8 East, Willamette Meridian, Marion County, Oregon. The objective was to obtain data for the characterization of the deep hydrothermal regime in the Cascades volcanic region in order to better define its geothermal resource potential. The depth and location of the thermal gradient hole were designed by Thermal to test the basis of the Clackamas geothermal system exploration model developed by Chevron Resources Company.

Iovenitti, J.L.; D'Olier, W.L.

1987-09-30T23:59:59.000Z

246

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

E-Print Network (OSTI)

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

2010-01-01T23:59:59.000Z

247

Exact Conservation Laws of the Gradient Expanded KadanoffBaym Equations  

E-Print Network (OSTI)

Exact Conservation Laws of the Gradient Expanded Kadanoff­Baym Equations J. Knoll1 , Yu. B. Ivanov1 rather than approximate conservation laws related to global symmetries of the system. The conserved approximation. These exact conservations are valid, provided a derivable approximation is used to describe

Knoll, Jörn

248

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

SciTech Connect

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

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

2013-06-01T23:59:59.000Z

249

Intensity and position measuring systems in the booster of the Zero Gradient Synchrotorn  

SciTech Connect

Soon the new booster for the Zero Gradient Synchrotron (ZGS) will be commissioned at Argonne. Three of its diagnostic systems will be described here: (1) the beam position system, (2) the toroid intensity measuring system and (3) the capacitive intensity measuring system.

Brunwell, F.R.; Kliss, R.M.; Schmitt, D.R.

1977-01-01T23:59:59.000Z

250

Long-Range Transport of Air Pollution under Light Gradient Wind Conditions  

Science Conference Proceedings (OSTI)

The long-range transport of air pollution on clew days under light gradient wind conditions is investigated from an analysis of all days with high oxidant concentrations in 1979 at locations in central Japan that are far from pollutant sources. ...

Hidemi Kurita; Kazutoshi Sasaki; Hisao Muroga; Hiromasa Ueda; Shinji Wakamatsu

1985-05-01T23:59:59.000Z

251

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

252

Local control gradients criterion for selection of neuroemulators for model reference adaptive neurocontrol  

Science Conference Proceedings (OSTI)

We discuss neural identification and control of nonlinear dynamic plant. We analyze a problem of selection of a proper neuroemulator for training neurocontrollers, and we propose a new effective criterion based on the analysis of local gradients of neuroemulator's ... Keywords: extended Kalman Filter, neurocontrol, neuroemulator, recurrent neural network

A. N. Chernodub

2012-04-01T23:59:59.000Z

253

Optimal study of distributed generation impact on electrical distribution networks using GA and generalized reduced gradient  

Science Conference Proceedings (OSTI)

This paper presents the effect of Distributed Generators (DG) existence in the electrical power distribution networks taking IEEE 14 and IEEE 30 bus test feeders as proposed systems. The analysis is done to examine the effect on the overall system losses ... Keywords: IEEE 14 bus system, IEEE 30 bus system and optimization, distributed generator (DG), generalized reduced gradient (GRG), genetic algorithms (GA)

Samuel Raafat Fahim; Walid Helmy; Hany M. Hasanien; M. A. L. Badr

2011-03-01T23:59:59.000Z

254

A Mean-Gradient Model of the Dry Convective Boundary Layer  

Science Conference Proceedings (OSTI)

A mean-gradient model of the dry convective boundary layer is developed using a convective mass flux representation of the turbulent fluxes. A top-hat model of thermals is used to represent the average characteristics of updrafts and downdrafts ...

Shouping Wang; Bruce A. Albrecht

1990-01-01T23:59:59.000Z

255

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

256

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

E-Print Network (OSTI)

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

Michael Herrmann; Barbara Niethammer

2010-08-21T23:59:59.000Z

257

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

258

Geostrophic Adjustment and Restratification of a Mixed Layer with Horizontal Gradients above a Stratified Layer  

Science Conference Proceedings (OSTI)

The restratification of a mixed layer with horizontal density gradients above a stratified layer is considered. Solutions are obtained on the assumption that the width across this front is much larger than the local radius of deformation ?bh?/|f| based ...

Amit Tandon; Chris Garrett

1995-10-01T23:59:59.000Z

259

Complex flow in lowest crustal, anastomosing mylonites: Strain gradients in a Kohistan gabbro, northern Pakistan  

E-Print Network (OSTI)

, northern Pakistan L. Arbaret1 and J.-P. Burg Geologisches Institut, ETH-Zentrum, Zurich, Switzerland localization in near paleo-Moho metagabbros of the Kohistan Arc, northern Pakistan, produced anastomosing shear: Strain gradients in a Kohistan gabbro, northern Pakistan, J. Geophys. Res., 108(B10), 2467, doi:10

Paris-Sud XI, Université de

260

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

E-Print Network (OSTI)

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

Levin, Lisa

Note: This page contains sample records for the topic "ther mal gradients" 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

Segmenting images with gradient-based edge detection using Membrane Computing  

Science Conference Proceedings (OSTI)

In this paper, we present a parallel implementation of a new algorithm for segmenting images with gradient-based edge detection by using techniques from Natural Computing. This bio-inspired parallel algorithm has been implemented in a novel device architecture ... Keywords: CUDA, Edge detection, Membrane Computing, Sobel algorithm, Tissue P systems

Daniel DAz-Pernil; Ainhoa Berciano; Francisco PeA-Cantillana; Miguel A. GutiRrez-Naranjo

2013-06-01T23:59:59.000Z

262

Using coevolution and gradient-based learning for the virus game  

Science Conference Proceedings (OSTI)

This paper presents a novel coevolutionary model which is used to create strong game (The Virus Game) playing strategies. We use two approaches to coevolve Artificial Neural Networks (ANN) which evaluate board positions of a two player zero-sum game ... Keywords: artificial neural networks, coevolution, gradient-based learning, virus game

Munir H Naveed; Peter I Cowling

2006-12-01T23:59:59.000Z

263

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

E-Print Network (OSTI)

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

McMaster University

264

A NONLINEAR TWO-PHASE STEFAN PROBLEM WITH MELTING POINT GRADIENT  

E-Print Network (OSTI)

A NONLINEAR TWO-PHASE STEFAN PROBLEM WITH MELTING POINT GRADIENT: A CONSTRUCTIVE APPROACH D. D. Ang-dimensional two-phase Stefan problem, modeling a layer of solid material floating on liquid. The model includes of a cake of ice floating in water after the surface of the ice has received a fresh snowfall

Keinert, Fritz

265

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

266

The Conjugate-Gradient Variational Analysis and Initialization Method: An Application to MONEX SOP 2 Data  

Science Conference Proceedings (OSTI)

A conjugate-gradient variational blending technique, based on the method of direct minimization, has been developed and applied to the problem of initialization in a limited-area model in the summer monsoon region. The aim is to blend gridded ...

Mohan K. Ramamurthy; I. M. Navon

1992-10-01T23:59:59.000Z

267

The effect of the stiffness gradient on the just noticeable difference between surface regions  

Science Conference Proceedings (OSTI)

Numerous studies have considered the ability of humans to perceive differences in forces and how this affects our ability to interpret the properties of materials. Previous research has not considered the effect of the rate of change of the material ... Keywords: JND, exploratory procedures, gradient, perception, stiffness

Umut Koak; Karljohan Lundin Palmerius; Camilla Forsell; Matthew Cooper

2012-06-01T23:59:59.000Z

268

SLAC/CERN high gradient tests on an X-band accelerating section  

E-Print Network (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 grad...

Wang, J W; Loewen, R J; Ruth, Ronald D; Vlieks, A E; Wilson, Ian H; Wuensch, Walter

1995-01-01T23:59:59.000Z

269

Discontinuous Modelling of Crack Propagation in a Gradient-Enhanced Continuum  

E-Print Network (OSTI)

. Baz?ant, Nonlocal damage theory, ASCE Journal of Engi- neering Mechanics, 113, (1987), 15121533. [2] M. G. D. Geers, R. de Borst, W. A. M. Brekelmans, R. H. J. Peerlings, Strain- based transient-gradient damage model for failure analyses, Computer Methods...

Simone, A; Wells, G N; Sluys, L J

270

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

271

Formation of a Sharp Snow Gradient in a Midwestern Heavy Snow Event  

Science Conference Proceedings (OSTI)

A case study of the 1314 March 1999 heavy snow event across southern Missouri and neighboring states is presented. Of the many features that made this storm notable, the very sharp gradient on the northern periphery of the snowfall field was ...

Patrick S. Market; David Cissell

2002-08-01T23:59:59.000Z

272

Ludeman's PL/I FORMAC gradient problem as handled by FORTRAN SYMBOLANG  

Science Conference Proceedings (OSTI)

A program is presented which produces FORTRAN statements defining the gradient of a function of several variables given by an arithmetic expression in the variables and the functions SIN, COS, and EXP. The program is coded in FORTRAN and uses the SLIP ...

Herbert J. Bernstein

1970-01-01T23:59:59.000Z

273

The 1985 Geothermal Gradient Drilling Project for the State of Washington  

Science Conference Proceedings (OSTI)

This report describes seven geothermal gradient test holes in the southern Washington Cascade Mountains. The objectives of the drilling program were to: (1) more accurately define the general extent of potential geothermal resources in the southern Washington Cascades, and (2) evaluate specific targets that are geologically and structurally favorable for the occurrence of geothermal resources. (ACR)

Barnett, B.

1986-02-01T23:59:59.000Z

274

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

E-Print Network (OSTI)

MPC for Wind Power Gradients -- Utilizing Forecasts, Rotor Inertia, and Central Energy Storage iterations. We demonstrate our method in simulations with various wind scenarios and prices for energy. INTRODUCTION Today, wind power is the most important renewable energy source. For the years to come, many

275

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

276

Quantum-limited measurement of magnetic-field gradient with entangled atoms  

E-Print Network (OSTI)

We propose a method to detect the microwave magnetic-field gradient by using a pair of entangled two-component Bose-Einstein condensates. We consider the two spatially separated condensates to be coupled to the two different magnetic fields. The magnetic-field gradient can be determined by measuring the variances of population differences and relative phases between the two-component condensates in two wells. The precision of measurement can reach the Heisenberg limit. We study the effects of one-body and two-body atom losses on the detection. We find that the entangled atoms can outperform the uncorrelated atoms in probing the magnetic fields in the presence of atom losses. The effect of atom-atom interactions is also discussed.

H. T. Ng

2013-01-15T23:59:59.000Z

277

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

Open Energy Info (EERE)

Sabin, Et Al., 2010) Sabin, Et Al., 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Hawthorne Area (Sabin, Et Al., 2010) Exploration Activity Details Location Hawthorne Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness not indicated DOE-funding Unknown Notes In lieu of Seabee TGH drilling, GPO awarded a large IDIQ TGH drilling contract in December, 2009. Over the next two years, 90 500-ft TGHs will be installed at select sites in California and Nevada. Interim data from this campaign are already available for the Chocolate Mountains and Hawthorne. Results of these programs can be found in the Chocolate Mountains and Hawthorne papers also available in this volume. References Andrew Sabin, S. Bjornstad, M. Lazaro, D. Meade, C. Page, S. Alm, A.

278

Thermal Gradient Holes At Walker-Lane Transitional Zone Region (Pritchett,  

Open Energy Info (EERE)

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

279

Thermal Gradient Holes At Cove Fort Area (Warpinski, Et Al., 2002) | Open  

Open Energy Info (EERE)

Et Al., 2002) Et Al., 2002) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Cove Fort Area (Warpinski, Et Al., 2002) 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

280

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

Note: This page contains sample records for the topic "ther mal gradients" 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.


281

Thermal Gradient Holes At Fort Bidwell Area (Lafleur, Et Al., 2010) | Open  

Open Energy Info (EERE)

Bidwell Area (Lafleur, Et Al., 2010) Bidwell Area (Lafleur, Et Al., 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Fort Bidwell Area (Lafleur, Et Al., 2010) Exploration Activity Details Location Fort Bidwell Area Exploration Technique Thermal Gradient Holes Activity Date Usefulness useful DOE-funding Unknown Notes "Four wells have been successfully drilled into this resource since the early 1980s using a combination of funds provided by the California Energy Commission (CEC) and the United State Department of Energy (USDOE). The first three wells, FB-1, -2 and -3 have been discussed in a previous paper (Barker et al., 2005). The current status of the FBIC project to evaluate the potential geothermal resource under the reservation is that a deep

282

Hybrid permanent magnet gradient dipoles for the recycler ring at Fermilab  

SciTech Connect

Hybrid permanent magnets provide the magnetic fields for an anti- proton storage ring which is under construction at Fermilab. Using a combined function lattice, gradient magnets provide the bending, focusing and sextupole correction for the regular cells. Shorter magnets without sextupole are used in dispersion suppressor cells. These magnets use a 4.7 m ( 3 m) long iron shell for flux return, bricks of 25.4 mm thick strontium ferrite supply the flux and transversely tapered iron poles separated by aluminum spacers set the shape of the magnetic field. Central fields of 0.14 T with gradients of {approx}6%/inch ({approx}13%/inch) are required. Field errors are expected to be less than 10{sup -4} of the bend field over an aperture of {+-}40 mm (horizontal) {times} {+-}20 mm (vertical). Design, procurement, fabrication, pole potential adjustment, field shape trimming and measured fields will be reported.

Brown, B.C.; Dimarco, J.; Foster, G.W.; Glass, H.D.; Haggard, J.E.; Harding, D.J.; Jackson, G.R.; May, M.R. Nicol, T.H.; Ostiguy, J.-F.; Schlabach, R.; Volk, J.T.

1997-11-01T23:59:59.000Z

283

A high-gradient high-duty-factor RF photo-cathode electron gun  

Science Conference Proceedings (OSTI)

We describe the analysis and preliminary design of a high-gradient, high-duty factor RF photocathode gun. The gun is designed to operate at high repetition rate or CW, with high gradient on the cathode surface to minimize emittance growth due to space charge forces at high bunch charge. The gun may also be operated in a solenoidal magnetic field for emittance compensation. The design is intended for use in short-pulse, high-charge, and high-repetition rate applications such as linac based X-ray sources. We present and compare the results of gun simulations using different codes, as well as RF and thermal analysis of the structure.

Robert Rimmer; N. Hartman; S. Lidia; S.H. Wang

2002-08-01T23:59:59.000Z

284

Gradient formula for the beta-function of 2d quantum field theory  

E-Print Network (OSTI)

We give a non-perturbative proof of a gradient formula for beta functions of two-dimensional quantum field theories. The gradient formula has the form \\partial_{i}c = - (g_{ij}+\\Delta g_{ij} +b_{ij})\\beta^{j} where \\beta^{j} are the beta functions, c and g_{ij} are the Zamolodchikov c-function and metric, b_{ij} is an antisymmetric tensor introduced by H. Osborn and \\Delta g_{ij} is a certain metric correction. The formula is derived under the assumption of stress-energy conservation and certain conditions on the infrared behaviour the most significant of which is the condition that the large distance limit of the field theory does not exhibit spontaneously broken global conformal symmetry. Being specialized to non-linear sigma models this formula implies a one-to-one correspondence between renormalization group fixed points and critical points of c.

Friedan, Daniel

2009-01-01T23:59:59.000Z

285

Pushing the Gradient Limitations of Superconducting Photonic Band Gap Structure Cells  

SciTech Connect

Superconducting photonic band gap resonators present us with unique means to place higher order mode couples in an accelerating cavity and efficiently extract HOMs. An SRF PBG resonator with round rods was successfully tested at LANL demonstrating operation at 15 MV/m. Gradient in the SRF PBG resonator was limited by magnetic quench. To increase the quench threshold in PBG resonators one must design the new geometry with lower surface magnetic fields and preserve the resonator's effectiveness for HOM suppression. The main objective of this research is to push the limits for the high-gradient operation of SRF PBG cavities. A NCRF PBG cavity technology is established. The proof-of-principle operation of SRF PBG cavities is demonstrated. SRF PBG resonators are effective for outcoupling HOMs. PBG technology can significantly reduce the size of SRF accelerators and increase brightness for future FELs.

Simakov, Evgenya I. [Los Alamos National Laboratory; Haynes, William B. [Los Alamos National Laboratory; Kurennoy, Sergey S. [Los Alamos National Laboratory; Shchegolkov, Dmitry [Los Alamos National Laboratory; O'Hara, James F. [Los Alamos National Laboratory; Olivas, Eric R. [Los Alamos National Laboratory

2012-06-07T23:59:59.000Z

286

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

287

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

288

Heisenberg-limited measurement of magnetic-field gradient with multipartite entangled states  

E-Print Network (OSTI)

We propose a method to detect the magnetic-field gradient using an atomic spin chain. We consider to use W-states, which are a specific class of multipartite entangled states, for precision measurement. The magnetic-field gradient can be determined by measuring the coherence of the state. We find that the Heisenberg-limited measurement can be obtained even using imperfect W-states and in the presence of various types of noises, respectively. We discuss the implementations of the schemes with trapped ions and ultracold atoms in optical lattices. Our proposal can be realized by using an order of several tens of trapped ions with current technology. This robust method may be useful to the applications of magnetic resonance imaging.

H. T. Ng; K. Kim

2013-09-16T23:59:59.000Z

289

Production of radioactivity in local soil at AGS (Alternating Gradient Synchrotron) fast neutrino beam  

Science Conference Proceedings (OSTI)

Brookhaven National Laboratory (BNL) has constructed a new neutrino production target station at the Alternating Gradient Synchrotron (AGS). A study has been conducted in the vicinity of the old target area to determine the radiological consequences of operating this experimental facility. Results from all areas of the study are presented along with estimates of the potential environmental impact of the old and new facilities. 12 refs., 15 figs., 3 tabs.

Gollon, P.J.; Rohrig, N.; Hauptmann, M.G.; McIntyre, K.; Miltenberger, R.; Naidu, J.

1989-10-01T23:59:59.000Z

290

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 Mller

2008-01-08T23:59:59.000Z

291

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

SciTech Connect

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

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

1980-01-01T23:59:59.000Z

292

Major transitions in evolution linked to thermal gradients above hydrothermal vents  

E-Print Network (OSTI)

The emergence of the main divisions of today's life: (1) unicellular prokaryotes, (2) unicellular eukaryotes, (3) multicellular eukaryotes, and (4) metazoans, are examples of the--still unexplained--major transitions in evolution. Regarding the origin of life, I have proposed that primordial life functioned as heat engine (thermosynthesis) while thermally cycled in convecting volcanic hot springs. Here I argue for a role of thermal gradients above submarine hydrothermal vents (SHV) in several major transitions. The last decade has witnessed the emergence of phononics, a novel discipline in physics based on controlled heat transport in thermal gradients. It builds thermal analogs to electronic devices: the thermal diode, the thermal transistor, the thermal switch, the thermal amplifier, the thermal memory--the thermal computer has been proposed. Encouraged by (1) the many similarities between microtubules (MT) and carbon nanotubes, which have a very high thermal conductivity, and (2) the recent discovery of a silk protein which also has a very high thermal conductivity, I combine and extend the mentioned ideas, and propose the general conjecture that several major transitions of evolution were effected by thermal processes, with four additional partial conjectures: (1) The first organisms used heat engines during thermosynthesis in convection cells; (2) The first eukaryotic cells used MT during thermosynthesis in the thermal gradient above SHV; (3) The first metazoans used transport of water or in water during thermosynthesis above SHV under an ice-covered ocean during the Gaskiers Snowball Earth; and (4) The first mammalian brain used a thermal machinery based on thermal gradients in or across the cortex. When experimentally proven these conjectures, which are testable by the methods of synthetic biology, would significantly enhance our understanding of life.

Anthonie W. J. Muller

2012-12-03T23:59:59.000Z

293

In-Plane Focusing of Terahertz Surface Waves on a Gradient Index Metamaterial Film  

E-Print Network (OSTI)

We designed and implemented a gradient index metasurface for the in-plane focusing of confined terahertz surface waves. We measured the spatial propagation of the surface waves by two-dimensional mapping of the complex electric field using a terahertz near-field spectroscope. The surface waves were focused to a diameter of 500 \\micro m after a focal length of approx. 2 mm. In the focus, we measured a field amplitude enhancement of a factor of 3.

Volk, Martin F; Neu, Jens; Beigang, Ren; Rahm, Marco

2013-01-01T23:59:59.000Z

294

Refurbishment of the vacuum system of the Brookhaven Alternating Gradient Synchrotron  

SciTech Connect

Three years ago a program was initiated at Brookhaven National Laboratory to upgrade the Alternating Gradient Synchrotron (AGS) vacuum system. The three objectives of this work were to: (1) improve the vacuum system reliability; (2) improve its maintainability; and (3) improve its operating pressure from the present 2-3 /times/ 10/sup /minus/7/ Torr to < 10/sup /minus/8/ Torr. This paper discusses how these objectives can be met. 9 refs., 8 figs., 1 tab.

Welch, K.M.; Tuozzolo, J.E.; McIntyre, G.T.; Skelton, R.; Brown, J.M.; Gill, S.M.; Barry, J.

1989-01-01T23:59:59.000Z

295

X-band EPR imaging as a tool for gradient dose reconstruction in irradiated bones  

SciTech Connect

Purpose: Various tools are currently available for dose reconstruction in individuals after accidental exposure to ionizing radiation. Among the available biological analyses, Monte Carlo simulations, and biophysical methods, such as electron paramagnetic resonance (EPR), the latter has proved its usefulness for retrospective dosimetry. Although EPR spectroscopy is probably the most sensitive technique, it does not provide spatial dosimetric data. This information is, however, highly desirable when steep dose gradient irradiations are involved. The purpose of this work was to explore the possibilities of EPR imaging (EPRI) for spatial dose reconstruction in irradiated biological material. Methods: X-band EPRI was used to reconstruct ex vivo the relative dose distribution in human bone samples and hydroxyapatite phantoms after irradiation with brachytherapy seeds or x rays. Three situations were investigated: Homogeneous, stepwise gradient, and continuous gradient irradiation. Results: EPRI gave a faithful relative spin density distribution in bone samples and in hydroxyapatite phantoms. Measured dose ratios were in close agreement with the actual delivered dose ratios. EPRI was able to distinguish the dose gradients induced by two different sources ({sup 125}I and {sup 192}Ir). However, the measured spatial resolution of the system was 1.9 mm and this appeared to be a limiting factor. The method could be improved by using new signal postprocessing strategies. Conclusions: This study demonstrates that EPRI can be used to assess the regional relative dose distribution in irradiated bone samples. The method is currently applicable to ex vivo measurements of small size samples with low variation in tissue density but is likely to be adapted for in vivo application using L-band EPRI.

Leveque, Philippe; Godechal, Quentin; Bol, Anne; Trompier, Francois; Gallez, Bernard [Biomedical Magnetic Resonance Unit, Universite catholique de Louvain, B-1200 Brussels (Belgium); Molecular Imaging and Experimental Radiotherapy Unit, Universite catholique de Louvain, B-1200 Brussels (Belgium); Institut de Surete Nucleaire et de Radioprotection, F-92262 Fontenay-aux-Roses (France); Biomedical Magnetic Resonance Unit, Universite catholique de Louvain, B-1200 Brussels (Belgium)

2009-09-15T23:59:59.000Z

296

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

E-Print Network (OSTI)

Critically refracted longitudinal (LCR) waves have been investigated as a possible technique for the evaluation of the residual stress gradients present in ductile iron castings. Residual stresses are likely to develop in ductile cast iron during the cooling phase of a casting process. A LCR probe fabricated for previous research was used to make the velocity measurements. The samples investigated were of different modularity and two were annealed while one was not. The samples were milled at increments of approximately two millimeters and the LCR velocities were taken-at each increment. This provided data for the mapping of velocity versus depth which represents the residual stress gradient. To confirm the presence of the residual stress gradient, strain gages were attached to similar samples and the samples were saw cut with the intent to relieve residual stresses. The strain gages indicated that residual stresses were relieved by the sawcutting. The strain gage data was found to support the LCR velocity map to an extent. Both sets of data indicate compressive stresses on the surface. The data also allowed for an evaluation of the annealing procedure used. The results showed that even after full annealing remnant stresses are still present in the bars tested.

Pfluger, Ron Atlan

1995-01-01T23:59:59.000Z

297

T2CG1, a package of preconditioned conjugate gradient solvers for TOUGH2  

DOE Green Energy (OSTI)

Most of the computational work in the numerical simulation of fluid and heat flows in permeable media arises in the solution of large systems of linear equations. The simplest technique for solving such equations is by direct methods. However, because of large storage requirements and accumulation of roundoff errors, the application of direct solution techniques is limited, depending on matrix bandwidth, to systems of a few hundred to at most a few thousand simultaneous equations. T2CG1, a package of preconditioned conjugate gradient solvers, has been added to TOUGH2 to complement its direct solver and significantly increase the size of problems tractable on PCs. T2CG1 includes three different solvers: a Bi-Conjugate Gradient (BCG) solver, a Bi-Conjugate Gradient Squared (BCGS) solver, and a Generalized Minimum Residual (GMRES) solver. Results from six test problems with up to 30,000 equations show that T2CG1 (1) is significantly (and invariably) faster and requires far less memory than the MA28 direct solver, (2) it makes possible the solution of very large three-dimensional problems on PCs, and (3) that the BCGS solver is the fastest of the three in the tested problems. Sample problems are presented related to heat and fluid flow at Yucca Mountain and WIPP, environmental remediation by the Thermal Enhanced Vapor Extraction System, and geothermal resources.

Moridis, G.; Pruess, K.; Antunez, E. [Lawrence Berkeley Lab., CA (United States). Earth Sciences Div.

1994-03-01T23:59:59.000Z

298

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

299

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 1450C 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

300

Carbon Nitrogen, and Oxygen Galactic Gradients: A Solution to the Carbon Enrichment Problem  

E-Print Network (OSTI)

Eleven models of Galactic chemical evolution, differing in the carbon, nitrogen,and oxygen yields adopted, have been computed to reproduce the Galactic O/H values obtained from H II regions. All the models fit the oxygen gradient, but only two models fit also the carbon gradient, those based on carbon yields that increase with metallicity due to stellar winds in massive stars (MS) and decrease with metallicity due to stellar winds in low and intermediate mass stars (LIMS). The successful models also fit the C/O versus O/H evolution history of the solar vicinity obtained from stellar observations. We also compare the present day N/H gradient and the N/O versus O/H and the C/Fe, N/Fe, O/Fe versus Fe/H evolution histories of the solar vicinity predicted by our two best models with those derived from H II regions and from stellar observations. While our two best models fit the C/H and O/H gradients as well as the C/O versus O/H history, only Model 1 fits well the N/H gradient and the N/O values for metal poor stars but fails to fit the N/H values for metal rich stars. Therefore we conclude that our two best models solve the C enrichment problem, but that further work needs to be done on the N enrichment problem. By adding the C and O production since the Sun was formed predicted by Models 1 and 2 to the observed solar values we find an excellent agreement with the O/H and C/H values of the solar vicinity derived from H II regions O and C recombination lines. One of the most important results of this paper is that the fraction of carbon due to MS and LIMS in the interstellar medium is strongly dependent on time and on the galactocentric distance; at present about half of the carbon in the interstellar medium of the solar vicinity has been produced by MS and half by LIMS.

L. Carigi; M. Peimbert; C. Esteban; J. Garcia-Rojas

2004-08-23T23:59:59.000Z

Note: This page contains sample records for the topic "ther mal gradients" 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

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

302

A Comparison of Methods for Computing the Sigma-Coordinate Pressure Gradient Force for Flow over Sloped Terrain in a Hybrid Theta-Sigma Model  

Science Conference Proceedings (OSTI)

Five methods for computing the pressure gradient force within a sigma domain of a hybrid model are compared for flow over a steeply sloped terrain. The comparison includes pressure gradient calculations determined from a direct transformation to ...

Donald R. Johnson; Louis W. Uccellini

1983-04-01T23:59:59.000Z

303

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

Science Conference Proceedings (OSTI)

The WignerVille distribution, a new tool in the timefrequency analysis of signals, is applied to temperature gradient microstructure records. In particular, the WignerVille distribution is used to compute the local instantaneous and maximum ...

Jrg Imberger; Boualem Boashash

1986-12-01T23:59:59.000Z

304

Gyrokinetic simulations of the nonlinear upshift of the critical density gradient for TEM turbulence in tokamak fusion plasmas  

E-Print Network (OSTI)

The effect of collisionality on a new nonlinear upshift of the critical density gradient for onset of Trapped Electron Mode (TEM) turbulence is investigated in detail. Both linear and nonlinear, high resolution simulations ...

Zeller, Kyle M. (Kyle Montgomery)

2006-01-01T23:59:59.000Z

305

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

306

The Impact of Gradient Wind Imbalance on Potential Intensity of Tropical Cyclones in an Unbalanced Slab Boundary Layer Model  

Science Conference Proceedings (OSTI)

The assumption of gradient wind balance is customarily made so as to derive the theoretical upper-bound intensity of a mature tropical cyclone. Emanuel's theory of hurricane potential intensity (E-PI) makes use of this assumption, whereas more ...

Thomas Frisius; Daria Schnemann; Jonathan Vigh

2013-07-01T23:59:59.000Z

307

Zonal gradients in the lower atmosphere and upper ocean across the windward Antilles in mid-summer 2012  

Science Conference Proceedings (OSTI)

This observational study examines zonal gradients in the lower atmosphere and upper ocean across the windward Antilles in mid-summer of 2012. While earlier work reported on meridional confluence, here the focus is on zonal enrichment of trade ...

Mark R. Jury

308

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

309

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

Science Conference Proceedings (OSTI)

In the Eady model, where the meridional potential vorticity (PV) gradient is zero, perturbation energy growth can be partitioned cleanly into three mechanisms: (i) shear instability, (ii) resonance, and (iii) the Orr mechanism. Shear instability ...

Hylke de Vries; John Methven; Thomas H. A. Frame; Brian J. Hoskins

2009-04-01T23:59:59.000Z

310

Humidity Gradient Profiles from Wind Profiling Radars Using the NOAA/ETL Advanced Signal Processing System (SPS)  

Science Conference Proceedings (OSTI)

An algorithm to compute the magnitude of humidity gradient profiles from the measurements of the zeroth, first, and second moments of wind profiling radar (WPR) Doppler spectra was developed and tested. The algorithm extends the National Oceanic ...

B. Boba Stankov; Earl E. Gossard; Bob L. Weber; Richard J. Lataitis; Allen B. White; Daniel E. Wolfe; David C. Welsh; Richard G. Strauch

2003-01-01T23:59:59.000Z

311

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

312

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

DOE Patents (OSTI)

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

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

1990-01-01T23:59:59.000Z

313

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

DOE Patents (OSTI)

A method and means are disclosed for a spatial and temporal probe for laser generated plumes based on density gradients includes generation of a plume of vaporized material from a surface by an energy source. The probe laser beam is positioned so that the plume passes through the probe laser beam. Movement of the probe laser beam caused by refraction from the density gradient of the plume is monitored. Spatial and temporal information, correlated to one another, is then derived. 15 figs.

Yeung, E.S.; Chen, G.

1990-05-01T23:59:59.000Z

314

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

DOE Patents (OSTI)

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

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

1990-05-01T23:59:59.000Z

315

Probability density function method for variable-density pressure-gradient-driven turbulence and mixing  

SciTech Connect

Probability density function (PDF) methods are extended to variable-density pressure-gradient-driven turbulence. We apply the new method to compute the joint PDF of density and velocity in a non-premixed binary mixture of different-density molecularly mixing fluids under gravity. The full time-evolution of the joint PDF is captured in the highly non-equilibrium flow: starting from a quiescent state, transitioning to fully developed turbulence and finally dissipated by molecular diffusion. High-Atwood-number effects (as distinguished from the Boussinesq case) are accounted for: both hydrodynamic turbulence and material mixing are treated at arbitrary density ratios, with the specific volume, mass flux and all their correlations in closed form. An extension of the generalized Langevin model, originally developed for the Lagrangian fluid particle velocity in constant-density shear-driven turbulence, is constructed for variable-density pressure-gradient-driven flows. The persistent small-scale anisotropy, a fundamentally 'non-Kolmogorovian' feature of flows under external acceleration forces, is captured by a tensorial diffusion term based on the external body force. The material mixing model for the fluid density, an active scalar, is developed based on the beta distribution. The beta-PDF is shown to be capable of capturing the mixing asymmetry and that it can accurately represent the density through transition, in fully developed turbulence and in the decay process. The joint model for hydrodynamics and active material mixing yields a time-accurate evolution of the turbulent kinetic energy and Reynolds stress anisotropy without resorting to gradient diffusion hypotheses, and represents the mixing state by the density PDF itself, eliminating the need for dubious mixing measures. Direct numerical simulations of the homogeneous Rayleigh-Taylor instability are used for model validation.

Bakosi, Jozsef [Los Alamos National Laboratory; Ristorcelli, Raymond J [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

316

Top hole drilling with dual gradient technology to control shallow hazards  

E-Print Network (OSTI)

Currently the "Pump and Dump" method employed by Exploration and Production (E&P) companies in deepwater is simply not enough to control increasingly dangerous and unpredictable shallow hazards. "Pump and Dump" requires a heavy dependence on accurate seismic data to avoid shallow gas zones; the kick detection methods are slow and unreliable, which results in a need for visual kick detection; and it does not offer dynamic well control methods of managing shallow hazards such as methane hydrates, shallow gas and shallow water flows. These negative aspects of "Pump and Dump" are in addition to the environmental impact, high drilling fluid (mud) costs and limited mud options. Dual gradient technology offers a closed system, which improves drilling simply because the mud within the system is recycled. The amount of required mud is reduced, the variety of acceptable mud types is increased and chemical additives to the mud become an option. This closed system also offers more accurate and faster kick detection methods in addition to those that are already used in the "Pump and Dump" method. This closed system has the potential to prevent the formation of hydrates by adding hydrate inhibitors to the drilling mud. And more significantly, this system successfully controls dissociating methane hydrates, over pressured shallow gas zones and shallow water flows. Dual gradient technology improves deepwater drilling operations by removing fluid constraints and offering proactive well control over dissociating hydrates, shallow water flows and over pressured shallow gas zones. There are several clear advantages for dual gradient technology: economic, technical and significantly improved safety, which is achieved through superior well control.

Elieff, Brandee Anastacia Marie

2006-08-01T23:59:59.000Z

317

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

318

Ultra high-gradient energy loss by a pulsed electron beam in a plasma  

SciTech Connect

The plasma wake-field mechanism can be used to couple energy at a high rate from a bunched electron beam into a plasma wave. We will present results from the Fermilab A0 facility where a beam with an initial energy of 14 MeV passes through the plasma to emerge with a much broader energy spread, spanning from a low of 3 MeV to a high of over 20 MeV. Over the 8 cm length of the 10{sup 14} cm{sup -3} plasma, this implies a 140 MeV/m deceleration and 72 MeV/m acceleration gradient.

Nikolai Barov et al.

2001-12-19T23:59:59.000Z

319

3D calculations of a fixed field alternating gradient synchrotron magnet  

SciTech Connect

A Spallation neutron source for materials science studies was designed at Argonne and required a fixed field alternating gradient (FFAG) synchrotron magnet. 3D electrostatic calculations were made to obtain the unsaturated magnet pole shape. This pole shape was refined using 3D magnetostatic calculations that included the steel permeability and coil geometry. Details of the calculations are given concerning such things as: size of the problem and how to split it up, the number and shape of the finite elements, choosing the electrostatic potential correctly and selecting the potential of the desired pole. 5 figs.

Lari, R.J.

1985-01-01T23:59:59.000Z

320

SECONDARY ELECTRON TRAJECTORIES IN HIGH-GRADIENT VACUUM INSULATORS WITH FAST HIGH-VOLTAGE PULSES  

Science Conference Proceedings (OSTI)

Vacuum insulators composed of alternating layers of metal and dielectric, known as high-gradient insulators (HGIs), have been shown to withstand higher electric fields than conventional insulators. Primary or secondary electrons (emitted from the insulator surface) can be deflected by magnetic fields from external sources, the high-current electron beam, the conduction current in the transmission line, or the displacement current in the insulator. These electrons are deflected either toward or away from the insulator surface and this affects the performance of the vacuum insulator. This paper shows the effects of displacement current from short voltage pulses on the performance of high gradient insulators. Generally, vacuum insulator failure is due to surface flashover, initiated by electrons emitted from a triple junction. These electrons strike the insulator surface thus producing secondary electrons, and can lead to a subsequent electron cascade along the surface. The displacement current in the insulator can deflect electrons either toward or away from the insulator surface, and affects the performance of the vacuum insulator when the insulator is subjected to a fast high-voltage pulse. Vacuum insulators composed of alternating layers of metal and dielectric, known as high-gradient insulators (HGIs), have been shown to withstand higher electric fields than conventional insulators. HGIs, being tolerant of the direct view of high-current electron and ion beams, and having desirable RF properties for accelerators, are a key enabling technology for the dielectric-wall accelerators (DWA) being developed at Lawrence Livermore National Laboratory (LLNL). Characteristically, insulator surface breakdown thresholds go up as the applied voltage pulse width decreases. To attain the highest accelerating gradient in the DWA, short accelerating voltage pulses are only applied locally, along the HGI accelerator tube, in sync with the charged particle bunch, and the effects of displacement current on trajectories of electrons emitted from HGI surface are particularly interesting. This paper presents simulated electron trajectories experiencing either constant or short-duration applied voltage pulses. Comparisons of these trajectories clearly indicate the importance of the voltage pulse shape, especially the rise time, in the flashover initiation process for HGIs.

Chen, Y; Blackfield, D; Nelson, S D; Poole, B

2010-04-21T23:59:59.000Z

Note: This page contains sample records for the topic "ther mal gradients" 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

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

DOE Patents (OSTI)

A functionally gradient material for a membrane reactor for converting methane gas into value-added-products includes an outer tube of perovskite, which contacts air; an inner tube which contacts methane gas, of zirconium oxide, and a bonding layer between the perovskite and zirconium oxide layers. The bonding layer has one or more layers of a mixture of perovskite and zirconium oxide, with the layers transitioning from an excess of perovskite to an excess of zirconium oxide. The transition layers match thermal expansion coefficients and other physical properties between the two different materials. 7 figs.

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

1996-11-12T23:59:59.000Z

322

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

DOE Patents (OSTI)

A functionally gradient material for a membrane reactor for converting methane gas into value-added-products includes an outer tube of perovskite, which contacts air; an inner tube which contacts methane gas, of zirconium oxide, and a bonding layer between the perovskite and zirconium oxide layers. The bonding layer has one or more layers of a mixture of perovskite and zirconium oxide, with the layers transitioning from an excess of perovskite to an excess of zirconium oxide. The transition layers match thermal expansion coefficients and other physical properties between the two different materials.

Balachandran, Uthamalingam (Hinsdale, IL); Dusek, Joseph T. (Lombard, IL); Kleefisch, Mark S. (Napersville, IL); Kobylinski, Thadeus P. (Lisle, IL)

1996-01-01T23:59:59.000Z

323

Active particles under confinement: Aggregation at the wall and gradient formation inside a channel  

E-Print Network (OSTI)

I study the confinement-induced aggregation phenomenon in a minimal model of self-propelled particles inside a channel. Starting from first principles, I derive a set of equations that govern the density profile of such a system at the steady-state, and calculate analytically how the aggregation at the walls varies with the physical parameters of the system. I also investigate how the gradient of the particle density varies if the inside of the channel is partitioned into two regions within which the active particles exhibit distinct levels of fluctuations in their directions of travel.

Chiu Fan Lee

2013-04-19T23:59:59.000Z

324

The Cauchy problem for a quasilinear parabolic equation with gradient absorption  

SciTech Connect

The qualitative properties of solutions to the Cauchy problem for a degenerate parabolic equation containing a nonlinear operator of Baouendi-Grushin type and with gradient absorption whose density depends on time, as well as the space variables, are investigated. Bounds for the diameter of the support of the solution which are sharp with respect to time are obtained, together with its maximum. A condition which determines whether or not the phenomenon of decay to zero of the total mass of the solution occurs is discovered. Bibliography: 35 titles.

Markasheva, Vera A; Tedeev, Anatoli F [Institute of Applied Mathematics and Mechanics, Ukraine National Academy of Sciences, Donetsk (Ukraine)

2012-04-30T23:59:59.000Z

325

Comparison of two-equation turbulence models for boundary layers with pressure gradient  

SciTech Connect

This paper compares the performance of eight low Reynolds number k-epsilon and k-omega models for high Reynolds number, incompressible turbulent boundary layers with favorable, zero, and adverse pressure gradients. Results obtained underscore the k-epsilon model's unsuitability for such flows. Even more seriously, the k-epsilon model is demonstrated to be inconsistent with the well-established physical structure of the turbulent boundary layer, and low Reynolds number corrections cannot remove the inconsistency. By contrast, the k-omega model, with and without low Reynolds number modifications, proves to be very accurate for all of the tests conducted. 16 refs.

Wilcox, D.C. (DCW Industries, Inc., La Canada, CA (United States))

1993-08-01T23:59:59.000Z

326

A comparison of the Monte Carlo and the flux gradient method for atmospheric diffusion  

DOE Green Energy (OSTI)

In order to model the dispersal of atmospheric pollutants in the planetary boundary layer, various methods of parameterizing turbulent diffusion have been employed. The purpose of this paper is to use a three-dimensional particle-in-cell transport and diffusion model to compare the Markov chain (Monte Carlo) method of statistical particle diffusion with the deterministic flux gradient (K-theory) method. The two methods are heavily used in the study of atmospheric diffusion under complex conditions, with the Monte Carlo method gaining in popularity partly because of its more direct application of turbulence parameters. The basis of comparison is a data set from night-time drainage flow tracer experiments performed by the US Department of Energy Atmospheric Studies in Complex Terrain (ASCOT) program at the Geysers geothermal region in northern California. The Atmospheric Diffusion Particle-In-Cell (ADPIC) model used is the main model in the Lawrence Livermore National Laboratory emergency response program: Atmospheric Release Advisory Capability (ARAC). As a particle model, it can simulate diffusion in both the flux gradient and Monte Carlo modes. 9 refs., 6 figs.

Lange, R.

1990-05-01T23:59:59.000Z

327

Oxygen transport by oxygen potential gradient in dense ceramic oxide membranes  

DOE Green Energy (OSTI)

Numerous studies have been conducted in recent years on the partial oxidation of methane to synthesis gas (syngas: CO + H{sub 2}) with air as the oxidant. In partial oxidation, a mixed-oxide ceramic membrane selectively transports oxygen from the air; this transport is driven by the oxygen potential gradient. Of the several ceramic materials the authors have tested, a mixed oxide based on the Sr-Fe-Co-O system has been found to be very attractive. Extensive oxygen permeability data have been obtained for this material in methane conversion experiments carried out in a reactor. The data have been analyzed by a transport equation based on the phenomenological theory of diffusion under oxygen potential gradients. Thermodynamic calculations were used to estimate the driving force for the transport of oxygen ions. The results show that the transport equation deduced from the literature describes the permeability data reasonably well and can be used to determine the diffusion coefficients and the associated activation energy of oxygen ions in the ceramic membrane material.

Maiya, P.S.; Balachandran, U.; Dusek, J.T.; Mieville, R.L. [Argonne National Lab., IL (United States). Energy Technology Div.; Kleefisch, M.S.; Udovich, C.A. [Amoco Exploration/Production, Naperville, IL (United States)

1996-05-01T23:59:59.000Z

328

The UCLA/SLAC Ultra-High Gradient Cerenkov Wakefield Accelerator Experiment  

SciTech Connect

An experiment is planned to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range. This new UCLA/SLAC/USC collaboration will take advantage of the unique SLAC FFTB electron beam and its demonstrated ultra-short pulse lengths and high currents (e.g., {delta}{sub z} = 20 {micro}m at Q = 3 nC). The electron beam will be focused down and sent through varying lengths of fused silica capillary tubing with two different sizes: ID = 200 {micro}m/OD = 325 {micro}m and ID = 100 {micro}m/OD = 325 {micro}m. The pulse length of the electron beam will be varied in order to alter the accelerating gradient and probe the breakdown threshold of the dielectric structures. In addition to breakdown studies, we plan to collect and measure coherent Cerenkov radiation emitted from the capillary tube to gain information about the strength of the accelerating fields.

Thompson, M.C.; Badakov, H.; Rosenzweig, J.B.; Travish, G.; /UCLA; Hogan, M.; Ischebec, R.; Siemann, R.; Walz, D.; /SLAC; Scott, A.; /UC, Santa Barbara; Yoder, R.; /Manhattan Coll., Riverdale

2006-01-25T23:59:59.000Z

329

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

330

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

331

HIGH-GRADIENT, HIGH-TRANSFORMER-RATIO, DIELECTRIC WAKE FIELD ACCELERATOR  

SciTech Connect

The Phase I work reported here responds to DoE'ss stated need "...to develop improved accelerator designs that can provide very high gradient (>200 MV/m for electrons...) acceleration of intense bunches of particles." Omega-P'?s approach to this goal is through use of a ramped train of annular electron bunches to drive a coaxial dielectric wakefield accelerator (CDWA) structure. This approach is a direct extension of the CDWA concept from acceleration in wake fields caused by a single drive bunch, to the more efficient acceleration that we predict can be realized from a tailored (or ramped) train of several drive bunches. This is possible because of a much higher transformer ratio for the latter. The CDWA structure itself has a number of unique features, including: a high accelerating gradient G, potentially with G > 1 GeV/m; continuous energy coupling from drive to test bunches without transfer structures; inherent transverse focusing forces for particles in the accelerated bunch; highly stable motion of high charge annular drive bunches; acceptable alignment tolerances for a multi-section system. What is new in the present approach is that the coaxial dielectric structure is now to be energized by-not one-?but by a short train of ramped annular-shaped drive bunches moving in the outer coaxial channel of the structure. We have shown that this allows acceleration of an electron bunch traveling along the axis in the inner channel with a markedly higher transformer ratio T than for a single drive bunch. As described in this report, the structure will be a GHz-scale prototype with cm-scale transverse dimensions that is expected to confirm principles that can be applied to the design of a future THz-scale high gradient (> 500 MV/m) accelerator with mm-scale transverse dimensions. We show here a new means to significantly increase the transformer ratio T of the device, and thereby to significantly improve its suitability as a flexible and effective component in a future high energy, high gradient accelerator facility. We predict that the T of a high gradient CDWA can be increased by a substantial factor; this enhancement is dramatically greater than what has been demonstrated heretofore. This large enhancement in T that we predict arises from using a train of three or four drive bunches in which the spacing of the bunches and their respective charges are selected according to a simple principle that requires each bunch lose energy to the wakefields at the same rate, so as not to sacrifice drive beam efficiency?¢????as would be the case if one bunch exhausted its available energy while others had not. It is anticipated that results from the study proposed here can have a direct impact on design of the dielectric accelerator in a TeV-scale collider concept, and in the accelerator for an x-ray FEL.

Jay L. Hirshfield

2012-04-12T23:59:59.000Z

332

Reduction of Solvent Effect in Reverse Phase Gradient Elution LC-ICP-MS  

DOE Green Energy (OSTI)

Quantification in liquid chromatography (LC) is becoming very important as more researchers are using LC, not as an analytical tool itself, but as a sample introduction system for other analytical instruments. The ability of LC instrumentation to quickly separate a wide variety of compounds makes it ideal for analysis of complex mixtures. For elemental speciation, LC is joined with inductively coupled plasma mass spectrometry (ICP-MS) to separate and detect metal-containing, organic compounds in complex mixtures, such as biological samples. Often, the solvent gradients required to perform complex separations will cause matrix effects within the plasma. This limits the sensitivity of the ICP-MS and the quantification methods available for use in such analyses. Traditionally, isotope dilution has been the method of choice for LC-ICP-MS quantification. The use of naturally abundant isotopes of a single element in quantification corrects for most of the effects that LC solvent gradients produce within the plasma. However, not all elements of interest in speciation studies have multiple naturally occurring isotopes; and polyatomic interferences for a given isotope can develop within the plasma, depending on the solvent matrix. This is the case for reverse phase LC separations, where increasing amounts of organic solvent are required. For such separations, an alternative to isotope dilution for quantification would be is needed. To this end, a new method was developed using the Apex-Q desolvation system (ESI, Omaha, NE) to couple LC instrumentation with an ICP-MS device. The desolvation power of the system allowed greater concentrations of methanol to be introduced to the plasma prior to destabilization than with direct methanol injection into the plasma. Studies were performed, using simulated and actual linear methanol gradients, to find analyte-internal standard (AIS) pairs whose ratio remains consistent (deviations {+-} 10%) over methanol concentration ranges of 5%-35% (simulated) and 8%-32% (actual). Quadrupole (low resolution) and sector field (high resolution) ICP-MS instrumentation were utilized in these studies. Once an AIS pair is determined, quantification studies can be performed. First, an analysis is performed by adding both elements of the AIS pair post-column while performing the gradient elution without sample injection. A comparison of the ratio of the measured intensities to the atomic ratio of the two standards is used to determine a correction factor that can be used to account for the matrix effects caused by the mobile phase. Then, organic and/or biological molecules containing one of the two elements in the AIS pair are injected into the LC column. A gradient method is used to vary the methanol-water mixture in the mobile phase and to separate out the compounds in a given sample. A standard solution of the second ion in the AIS pair is added continuously post-column. By comparing the ratio of the measured intensities to the atomic ratio of the eluting compound and internal standard, the concentration of the injected compound can be determined.

Patrick Allen Sullivan

2005-12-17T23:59:59.000Z

333

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

334

Dense Plasma Focus Z-pinches for High Gradient Particle Acceleration  

SciTech Connect

The final Z-pinch stage of a Dense Plasma Focus (DPF) could be used as a simple, compact, and potentially rugged plasma-based high-gradient accelerator with fields at the 100 MV/m level. In this paper we review previously published experimental beam data that indicate the feasibility of such an DPF-based accelerator, qualitatively discuss the physical acceleration processes in terms of the induced voltages, and as a starting point examine the DPF acceleration potential by numerically applying a self-consistent DPF system model that includes the induced voltage from both macroscopic and instability driven plasma dynamics. Applications to the remote detection of high explosives and a multi-staged acceleration concept are briefly discussed.

Tang, V; Adams, M L; Rusnak, B

2009-07-24T23:59:59.000Z

335

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.

336

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

337

A scaled gradient projection method for the X-ray imaging of solar flares  

E-Print Network (OSTI)

In this paper we present a new optimization algorithm for the reconstruction of X-ray images of solar flares by means of the data collected by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). The imaging concept of the satellite is based of rotating modulation collimator instruments, which allow the use of both Fourier imaging approaches and reconstruction techniques based on the straightforward inversion of the modulated count profiles. Although in the last decade a greater attention has been devoted to the former strategies due to their very limited computational cost, here we consider the latter model and investigate the effectiveness of a scaled gradient projection method for the solution of the corresponding constrained minimization problem. Moreover, regularization is introduced through either an early stopping of the iterative procedure, or a Tikhonov term added to the discrepancy function, by means of a discrepancy principle accounting for the Poisson nature of the noise affecting th...

Bonettini, S

2013-01-01T23:59:59.000Z

338

Spatially Addressable Readout and Erasure of an Image in a Gradient Echo Memory  

E-Print Network (OSTI)

We show that portions of an image written into a gradient echo memory can be individually retrieved or erased on demand, an important step towards processing a spatially multiplexed quantum signal. Targeted retrieval is achieved by locally addressing the transverse plane of the storage medium, a warm 85Rb vapor, with a far-detuned control beam. Spatially addressable erasure is similarly implemented by imaging a bright beam tuned near the 85Rb D1 line in order to scatter photons and induce decoherence. Under our experimental conditions atomic diffusion is shown to impose an upper bound on the effective spatial capacity of the memory. The decoherence induced by the optical eraser is characterized and modeled as the response of a two level atom in the presence of a strong driving field.

Jeremy B. Clark; Quentin Glorieux; Paul D. Lett

2013-02-19T23:59:59.000Z

339

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

340

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

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341

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

342

Timescale for equilibration of N/Z gradients in dinuclear systems  

E-Print Network (OSTI)

Equilibration of N/Z in binary breakup of an excited and transiently deformed projectile-like fragment (PLF*), produced in peripheral collisions of 64Zn + 27Al, 64Zn, 209Bi at E/A = 45 MeV, is examined. The composition of emitted light fragments (3N/Z correlated with the heavy, neutron-rich target. Using the rotation angle as a clock, we deduce that N/Z equilibration persists for times as long as 3-4 zs (1zs = 1 x 10^-21 s = 300 fm/c). The rate of N/Z equilibration is found to depend on the initial neutron gradient within the PLF*.

K. Brown; S. Hudan; R. T. de Souza; J. Gauthier; R. Roy; D. V. Shetty; G. A. Souliotis; S. J. Yennello

2013-05-06T23:59:59.000Z

343

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

344

A second gradient theoretical framework for hierarchical multiscale modeling of materials  

SciTech Connect

A theoretical framework for the hierarchical multiscale modeling of inelastic response of heterogeneous materials has been presented. Within this multiscale framework, the second gradient is used as a non local kinematic link between the response of a material point at the coarse scale and the response of a neighborhood of material points at the fine scale. Kinematic consistency between these scales results in specific requirements for constraints on the fluctuation field. The wryness tensor serves as a second-order measure of strain. The nature of the second-order strain induces anti-symmetry in the first order stress at the coarse scale. The multiscale ISV constitutive theory is couched in the coarse scale intermediate configuration, from which an important new concept in scale transitions emerges, namely scale invariance of dissipation. Finally, a strategy for developing meaningful kinematic ISVs and the proper free energy functions and evolution kinetics is presented.

Luscher, Darby J [Los Alamos National Laboratory; Bronkhorst, Curt A [Los Alamos National Laboratory; Mc Dowell, David L [GEORGIA TECH

2009-01-01T23:59:59.000Z

345

Dosimetry in steep dose-rate gradient radiation fields: A challenge in clinical applications  

Science Conference Proceedings (OSTI)

The fundamental goal of radiotherapy is to reduce the damage to normal tissue and optimize the dose to the tumor with an associated high probability of cure. Because of this, an accurate and precise knowledge of the radiation dose distribution delivered around the tumor volume during radiotherapy treatments such as stereotactic radiosurgery, intensity modulated radiotherapy or brachytherapy with low-energy X-ray and beta particle sources is of great importance. However, in each of these radiation fields, there exists a steep dose-rate gradient which makes it very difficult to perform accurate dose measurements. In this work, the physics phenomena involved in the energy absorption for each of these situations are discussed, and a brief revision of what the Medical Physics community is doing is presented.

Massillon-JL, G. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, A.P. 20-364, 01000 DF (Mexico)

2010-12-07T23:59:59.000Z

346

Scaling of Macroscopic Properties of Porous Sediments Experiencing Compaction: Implications for Geothermal Gradient and Methane Inventory  

E-Print Network (OSTI)

Porous sediments in geological systems experience stress by the above-laying mass and consequent compaction, which may be significantly nonuniform across the massif. We derive scaling laws for the compaction of sediments of similar geological origin. With these laws, we evaluate the dependence of the transport properties of a fluid-saturated porous medium (permeability, effective molecular diffusivity, hydrodynamic dispersion, and thermal conductivity) on its porosity. In particular, we demonstrate irrelevance of the assumption of a uniform geothermal gradient for systems with nonuniform compaction and importance of the derived scaling laws for mathematical modelling of methane hydrate deposits, which are believed to have potential for impact on global climate change and Glacial-Interglacial cycles.

Goldobin, Denis S

2011-01-01T23:59:59.000Z

347

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

348

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

349

Design, construction, and initial operation of the Los Alamos National Laboratory salt-gradient solar pond  

DOE Green Energy (OSTI)

A 232 m/sup 2/ solar pond was constructed at Los Alamos National Laboratory for the purpose of studying pond hydrodynamics on a large scale and to complement the flow visualization and one-dimensional pond simulator experiments that are ongoing at the Laboratory. Design methods and construction techniques, some of which are unique to this pond, are described in detail. The pond was excavated from a soft volcanic rock known as tuff; such rock forms a large fraction of the Los Alamos area surface geology. Because tuff has a small thermal conductivity, little insulation was required to reduce perimeter energy losses. In addition, the strength of tuff permitted the pond to be built with vertical side walls; this design eliminated local side wall convection in the gradient zone that is possible with sloping side walls. Instrumentation in the pond consists of traversing and fixed rakes of thermometers and salinity probes, an underwater pyranometer, and a weather station. The traversing rake is a wheeled trolley driven vertically on a rectangular rail. Installed on the trolley are coplanar platinum RTDs, a point conductivity probe, and an induction salinometer. The stationary rake supports 28 thermocouples and 28 sample-fluid withdrawal taps located every 10 cm. About 127 T of sodium chloride has been introduced and is nearly dissolved. A 120-cm-thick salinity gradient was established and the pond is heating. Preliminary results indicate a lower-convective-zone heating rate of 1.2/sup 0/C/day during the pond's first month of operation. Recommendations on pond design, construction, and instrumentation are presented.

Jones, G.F.; Meyer, K.A.; Hedstrom, J.C.; Dreicer, J.S.; Grimmer, D.P.

1983-01-01T23:59:59.000Z

350

The effect of electron beam pitch angle and density gradient on solar type III radio bursts  

SciTech Connect

1.5D particle-in-cell simulations of a hot, low density electron beam injected into magnetized, maxwellian plasma were used to further explore the alternative non-gyrotropic beam driven electromagnetic (EM) emission mechanism, first studied in Tsiklauri, Phys. Plasmas 18, 052903 (2011). Variation of beam injection angle and background density gradient showed that the emission process is caused by the perpendicular component of the beam injection current, whereas the parallel component only produces Langmuir waves, which play no role in the generation of EM waves in our mechanism. Particular emphasis was put on the case, where the beam is injected perpendicularly to the background magnetic field, as this turned off any electrostatic wave generation along the field and left a purely electromagnetic signal in the perpendicular components. The simulations establish the following key findings: (i) Initially, waves at a few {omega}{sub ce}/{gamma} are excited, mode converted and emitted at Almost-Equal-To {omega}{sub pe} (ii) The emission intensity along the beam axis is proportional to the respective component of the kinetic energy of the beam; (iii) The frequency of the escaping EM emission is independent of the injection angle; (iv) A stronger background density gradient causes earlier emission; (v) The beam electron distribution function in phase space shows harmonic oscillation in the perpendicular components at the relativistic gyrofrequency; (vi) The requirement for cyclotron maser emission, ({partial_derivative}f/{partial_derivative}v{sub Up-Tack })>0, is fulfilled; (vii) The degree of linear polarization of the emission is strongly dependent on the beam injection angle; (viii) The generated electromagnetic emission is left-hand elliptically polarized as the pitch angle tends to 90 Degree-Sign ; and (ix) The generated electromagnetic energy is of the order of 0.1% of the initial beam kinetic energy.

Pechhacker, R.; Tsiklauri, D. [School of Physics and Astronomy, Queen Mary University of London, E1 4NS (United Kingdom)

2012-11-15T23:59:59.000Z

351

Three dimensional nuclear magnetic resonance spectroscopic imaging of sodium ions using stochastic excitation and oscillating gradients  

SciTech Connect

Nuclear magnetic resonance (NMR) spectroscopic imaging of {sup 23}Na holds promise as a non-invasive method of mapping Na{sup +} distributions, and for differentiating pools of Na{sup +} ions in biological tissues. However, due to NMR relaxation properties of {sup 23}Na in vivo, a large fraction of Na{sup +} is not visible with conventional NMR imaging methods. An alternate imaging method, based on stochastic excitation and oscillating gradients, has been developed which is well adapted to measuring nuclei with short T{sub 2}. Contemporary NMR imaging techniques have dead times of up to several hundred microseconds between excitation and sampling, comparable to the shortest in vivo {sup 23}Na T{sub 2} values, causing significant signal loss. An imaging strategy based on stochastic excitation has been developed which greatly reduces experiment dead time by reducing peak radiofrequency (RF) excitation power and using a novel RF circuit to speed probe recovery. Continuously oscillating gradients are used to eliminate transient eddy currents. Stochastic {sup 1}H and {sup 23}Na spectroscopic imaging experiments have been performed on a small animal system with dead times as low as 25{mu}s, permitting spectroscopic imaging with 100% visibility in vivo. As an additional benefit, the encoding time for a 32x32x32 spectroscopic image is under 30 seconds. The development and analysis of stochastic NMR imaging has been hampered by limitations of the existing phase demodulation reconstruction technique. Three dimensional imaging was impractical due to reconstruction time, and design and analysis of proposed experiments was limited by the mathematical intractability of the reconstruction method. A new reconstruction method for stochastic NMR based on Fourier interpolation has been formulated combining the advantage of a several hundredfold reduction in reconstruction time with a straightforward mathematical form.

Frederick, B.deB. [California Univ., Berkeley, CA (United States)]|[Lawrence Berkeley Lab., CA (United States)

1994-12-01T23:59:59.000Z

352

The Stability of Dilute Plasmas with Thermal and Composition Gradients. I. The Slow Conduction Limit: Overstable Gravity Modes  

E-Print Network (OSTI)

We analyze the stability of a dilute plasma with thermal and composition gradients in the limit where conduction is slow compared to the dynamical timescale. We find necessary and sufficient conditions for stability when the background magnetic field is either parallel or perpendicular to the thermal and composition gradients that are parallel to the gravitational field. We provide approximate solutions for all the relevant modes involved, which are driven by gravity, conduction, and diffusion. We discuss the astrophysical implications of our findings for a representative galaxy cluster where helium has sedimented.

Pessah, Martin E

2011-01-01T23:59:59.000Z

353

Well-posedness of a parabolic moving-boundary problem in the setting of Wasserstein gradient flows  

E-Print Network (OSTI)

We develop a gradient-flow framework based on the Wasserstein metric for a parabolic moving-boundary problem that models crystal dissolution and precipitation. In doing so we derive a new weak formulation for this moving-boundary problem and we show that this formulation is well-posed. In addition, we develop a new uniqueness technique based on the framework of gradient flows with respect to the Wasserstein metric. With this uniqueness technique, the Wasserstein framework becomes a complete well-posedness setting for this parabolic moving-boundary problem.

Jacobus W. Portegies; Mark A. Peletier

2008-12-06T23:59:59.000Z

354

Proceedings of the Institute of Transportation 50th Birthday Symposium April 23-24, 1998 The Transportation Enterprise: Challenges of ther 21st Century  

E-Print Network (OSTI)

study of the social costs of transportation (see work byand Costs of Transportation: Review and Prospects, Technical Change in Transportation: Social

Bertini, Robert L.; Orrick, Phyllis

1998-01-01T23:59:59.000Z

355

Finite - difference modeling of the Yucca Mountain, Nevada Area: a study of the regional water table gradients based on hydraulic conductivity contrasts  

E-Print Network (OSTI)

The Nevada Yucca Mountain site is being investigated to determine if it is a suitable site for the construction of a high-level nuclear waste repository. A feature of concern north of the selected site is an abrupt rise in the water table. This high gradient of 0.15 is flanked to the north by a moderate gradient of 0.015 and to the south by a very small gradient of 0.0001. Since the mechanisms creating this feature have the potential to cause changes in the position and configuration of the water table, they must be understood so risk analysis of the site may be performed. The three distinct gradient regions found at the site may be related to the Cenozoic volcanics, the Paleozoic clastic aquitard, and the Paleozoic carbonates. The large hydraulic gradient regionally corresponds with the northern limit of the Paleozoic carbonates, at the contact of the Eleana Formation, a Paleozoic aquitard. This study investigates, using finite difference modeling, the relationship between the steep hydraulic gradient and hydraulic conductivity contrasts. The site was modeled with flow boundaries to investigate the effects of variable gradient input to the flow balance calculation. A model was run with differential volcanic hydraulic conductivity zones with regulated flow into the carbonates. Constant head boundaries were implemented in models to investigate the effect of both a confined and open carbonate zone and with vertical barriers above the argillite/carbonate contact. The results of the study found that vertical and horizontal hydraulic conductivity contrasts do not fully account for the steep gradients, although the vertical contrasts marginally increase the gradient from horizontal contrasts. The confined carbonate zone model produced results that do not correlate with field data. The vertical barrier model did successfully reproduce steep gradients with gradient steepness related to flow restriction. Through the use of flow boundaries the steep gradient was reproduced successfully with a contrast of 0.8 orders of magnitude by allowing flow into the carbonate zone.

Davidson, Timothy Ross

1994-01-01T23:59:59.000Z

356

A composite P&O MPPT control with intelligent orthogonal particle swarm optimization for steepest gradient river current power generation system  

Science Conference Proceedings (OSTI)

This paper proposes a demonstration system of steepest gradient river current (SGRC) power generation with energy storage system. A direct-drive permanent magnet synchronous generator with multiple poles is used to transfer the steepest gradient river ... Keywords: full-bridge DC/DC converter controller, maximum power point tracking (MPPT), orthogonal particle swarm optimization (OPSO), perturbation and observation (P&O) method, steepest gradient river current (SGRC) power generation

Jian-Long Kuo; Chun-Jae Chang

2010-08-01T23:59:59.000Z

357

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

358

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

359

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

E-Print Network (OSTI)

Dual Gradient Drilling is an exciting technology which promises to solve the current technical hurdles and economic risks of Deepwater Drilling. Several techniques for Dual Gradient Drilling have been proposed to the industry. One such method involves installing a subsea booster pump at the seafloor with the aim of returning the drilling fluid back to the rig. The pump will manage annular pressures in the wellbore as circulation rates and mud weights vary and will permit early detection of wellbore influxes. Any such pump chosen to achieve this objective will be subjected to very high differential pressures and will be faced with the onerous task of lifting very abrasive and viscous mud slurries from the sea floor back to the drilling rig. This distance in deep water may be well within the range of about 4, 000 12,000 feet depending on the operating water depth of the rig. Several pump technologies available to the industry were examined. Piston pumps are very efficient and can withstand the high differential pressures encountered in the Mudlift Drilling System. However, their drawbacks are their large size and weight and high initial capital cost and maintenance costs. Centrifugal pumps on the other hand are relatively smaller than piston and diaphragm pumps and are generally less expensive. Disc pumps, with their non-impingement design are able to handle solids and fluids with a high gas volume fraction but, like centrifugal pumps, are generally less efficient than reciprocating pumps. Diaphragm pumps are capable of maintaining a constant rate regardless of pressure fluctuations. They can handle very abrasive solids with limited wear on the pump. They also excel at handling very viscous fluids and they can be modified to handle up to 95% gas volume fraction. Like piston pumps, they have very high efficiencies. The potential of each of these pump technologies to meet the requirements for the Mudlift Drilling System was examined in this thesis. The benefits and drawbacks of each of these pump technologies were highlighted and modifications to meet the demands of the mudlift system evaluated.

Oluwadairo, Tolulope

2007-12-01T23:59:59.000Z

360

Excitonic enhancement of nonradiative energy transfer from a quantum well in the optical near field of energy gradient quantum dots  

E-Print Network (OSTI)

Excitonic enhancement of nonradiative energy transfer from a quantum well in the optical near field of energy gradient quantum dots Sedat Nizamoglu, Pedro Ludwig Hernández-Martínez, Evren Mutlugun, Durmus misfit strains on the band offsets of Zn1-xBexO/ZnO quantum wells: A first-principles analysis J. Appl

Demir, Hilmi Volkan

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


361

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

E-Print Network (OSTI)

, and the results were quantified using a Live/DeadTM cell assay. This work is a preliminary study cell line (RTgill-W1)--towards water toxicity testing Tomasz Glawdel,a Caglar Elbuken,a Lucy E. J. Leeb that incorporates electroosmotic pumps, a concentration gradient generator and a fish cell line (rainbow trout gill

Le Roy, Robert J.

362

On Wind-Driven Mixed Layers with Strong Horizontal GradientsA Theory with Application to Coastal Upwelling  

Science Conference Proceedings (OSTI)

A theory of a two-dimensional wind-driven diabatic ocean mixed layer with strong horizontal gradients is formulated analytically. An equation that allows the relaxation of the strict Ekman balanceCoriolis force against wind stressis derived ...

R. A. De Szoeke; J. G. Richman

1984-02-01T23:59:59.000Z

363

Invariant Range Image Multi-Pose Face Recognition Using Gradient Face, Membership Matching Score and 3-Layer Matching Search  

Science Conference Proceedings (OSTI)

The purpose of this paper is to present the novel technique to solve the recognition errors in invariant range image multi-pose face recognition. The scale, center and pose error problems were solved by using the geometric transform [13]. Range image ... Keywords: multi-pose face recognition, facial range image, gradient transform, membership matching score, geometric transform, 3-Layer Matching Search

Seri Pansang; Boonwat Attachoo; Chom Kimpan; Makoto Sato

2005-02-01T23:59:59.000Z

364

Journal of Crystal Growth 193 (1998) 219--229 Visualization of convection in a simulated gradient freeze cell  

E-Print Network (OSTI)

the predictions of these models with the experiments and numerical simulations. They divided the models into three of the models agreed completely with all experimental data and numerical simulations. To verify the predictions of the above theoretical models, a simulated gradient freeze cell was made out of transparent plastic. The cell

Regel, Liya L.

365

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

366

THE PARABOLIC-PARABOLIC KELLER-SEGEL SYSTEM WITH CRITICAL DIFFUSION AS A GRADIENT FLOW IN Rd  

E-Print Network (OSTI)

THE PARABOLIC-PARABOLIC KELLER-SEGEL SYSTEM WITH CRITICAL DIFFUSION AS A GRADIENT FLOW IN Rd , d 3 ADRIEN BLANCHET1 AND PHILIPPE LAURENC¸OT2 Abstract. It is known that, for the parabolic-elliptic Keller for the parabolic-parabolic Keller-Segel system with critical porous-medium type diffusion in dimension Rd , d 3

Paris-Sud XI, Université de

367

The Open Cluster Chemical Analysis and Mapping Survey: Local Galactic Metallicity Gradient with APOGEE using SDSS DR10  

E-Print Network (OSTI)

The Open Cluster Chemical Analysis and Mapping (OCCAM) Survey aims to produce a comprehensive, uniform, infrared-based dataset for hundreds of open clusters, and constrain key Galactic dynamical and chemical parameters from this sample. This first contribution from the OCCAM survey presents analysis of 141 members stars in 28 open clusters with high-resolution metallicities derived from a large uniform sample collected as part of the SDSS-III/Apache Point Observatory Galactic Evolution Experiment (APOGEE). This sample includes the first high-resolution metallicity measurements for 22 open clusters. With this largest ever uniformly observed sample of open cluster stars we investigate the Galactic disk gradients of both [M/H] and [alpha/M]. We find basically no gradient across this range in [alpha/M], but [M/H] does show a gradient for R_{GC} < 10 kpc and a significant flattening beyond R_{GC} = 10 kpc. In particular, whereas fitting a single linear trend yields an [M/H] gradient of -0.09 +/- 0.03$ dex/kpc -...

Frinchaboy, Peter M; Jackson, Kelly M; O'Connell, Julia; Meyer, Brianne; Zasowski, Gail; Majewski, Steven R; Chojnowksi, S Drew; Johnson, Jennifer A; Prieto, Carlos Allende; Beers, Timothy C; Bizyaev, Dmitry; Brewington, Howard; Cunha, Katia; Ebelke, Garrett; Perez, Ana Elia Garcia; Hearty, Frederick R; Holtzman, Jon; Kinemuchi, Karen; Malanushenko, Elena; Malanushenko, Viktor; Marchante, Moses; Meszaros, Szabolcs; Muna, Demitri; Nidever, David L; Oravetz, Daniel; Pan, Kaike; Schiavon, Ricardo P; Schneider, Donald P; Shetrone, Matthew; Simmons, Audrey; Snedden, Stephanie; Smith, Verne V; Wilson, John C

2013-01-01T23:59:59.000Z

368

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

369

Magnetic field gradient effects on Rayleigh-Taylor instability with continuous magnetic field and density profiles  

SciTech Connect

In this paper, the effects of magnetic field gradient (i.e., the magnetic field transition layer effects) on the Rayleigh-Taylor instability (RTI) with continuous magnetic field and density profiles are investigated analytically. The transition layers of magnetic field and density with two different typical profiles are studied and the analytic expressions of the linear growth rate of the RTI are obtained. It is found that the magnetic field effects strongly reduce the linear growth rate of the RTI, especially when the perturbation wavelength is short. The linear growth rate of the RTI increases with the thickness of the magnetic field transition layer, especially for the case of small thickness of the magnetic field transition layer. When the magnetic field transition layer width is long enough, the linear growth rate of the RTI can be saturated. Thus when one increases the width of the magnetic field transition layer, the linear growth rate of the RTI increases only in a certain range, which depends on the magnetic field strength. The numerical results are compared with the analytic linear growth rates and they agree well with each other.

Yang, B. L. [Graduate School, China Academy of Engineering Physics, Beijing 100088 (China); Wang, L. F.; Ye, W. H. [HEDPS and CAPT, Peking University, Beijing 100871 (China); LCP, Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Xue, C. [LCP, Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)

2011-07-15T23:59:59.000Z

370

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

371

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

372

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 SpitzerHrm 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-Schlter 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

373

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

374

Electron Backscatter Diffraction Analysis of a CZT Growth Tip from a Vertical Gradient Freeze Furnace  

Science Conference Proceedings (OSTI)

Electronic backscatter diffraction (EBSD) was used to characterize the growth-tip region of a 4.2-cm diameter CdZnTe (CZT) boule grown using low-pressure Bridgman method in a vertical gradient freeze furnace. The boule was sectioned and polished and a section taken along the boule longitudinal centerline with an approximate surface area of 1-cm2 was used for optical and scanning electron microscopy. A collage was assembled using EBSD/SEM images to show morphological features, e.g., twin structure, grain structure, and overall crystal growth direction. Severely twinned regions originating from the tip and side walls were observed. The overall growth orientation was close to and directions. In some regions, the (001) poles of the CZT matrix aligned with the growth direction, while twins aligned such that (111) and (112) poles aligned with the growth direction. In some other areas, (112) or (011) poles of the CZT matrix aligned with the growth direction. New relationships between the CZT matrix and large Te polycrystalline particles were revealed: {11 }CZT??{1 00}Te and {001}CZT??{0 1}Te.

Sundaram, S. K.; Henager, Charles H.; Edwards, Danny J.; Schemer-Kohrn, Alan L.; Bliss, Mary; Riley, Brian J.

2011-08-15T23:59:59.000Z

375

Baseline drift effect on the performance of neutron and gamma ray discrimination using frequency gradient analysis  

E-Print Network (OSTI)

Frequency gradient analysis (FGA) effectively discriminates neutrons and gamma rays by examining the frequency-domain features of the photomultiplier tube anode signal. This approach is insensitive to noise but is inevitably affected by the baseline drift, similar to other pulse shape discrimination methods. The baseline drift effect is attributed to the factors such as power line fluctuation, dark current, noise disturbances, hum, and pulse tail in front-end electronics. This effect needs to be elucidated and quantified before the baseline shift can be estimated and removed from the captured signal. Therefore, the effect of baseline shift on the discrimination performance of neutrons and gamma rays with organic scintillation detectors using FGA is investigated in this paper. The relationship between the baseline shift and discrimination parameters of FGA is derived and verified by an experimental system consisting of an americium-beryllium source, a BC501A liquid scintillator detector, and a 5 GSPS 8-bit oscilloscope. Both theoretical and experimental results show that the estimation of the baseline shift is necessary, and the removal of baseline drift from the pulse shapes can improve the discrimination performance of FGA.

Guofu Liu; Xiaoliang Luo; Jun Yang; Cunbao Lin; Qingqing Hu; Jinxian Peng

2013-05-08T23:59:59.000Z

376

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

377

Particle Swarm Optimization and Gradient Descent Methods for Optimization of PI Controller for AGC of Multi-area Thermal-Wind-Hydro Power Plants  

Science Conference Proceedings (OSTI)

The automatic generation control (AGC) of three unequal interconnected Thermal, Wind and Hydro power plant has been designed with PI controller. Further computational intelligent technique Particle Swarm Optimization and conventional Gradient Descent ... Keywords: Automatic generation control, Particle swarm optimization, Gradient Descent method, Generation rate constraint, Area control error, Wind energy conversion system

Naresh Kumari, A N. Jha

2013-04-01T23:59:59.000Z

378

Application of gradient-based optimization methods for a rotor system with static stress, natural frequency,and harmonic response constraints  

Science Conference Proceedings (OSTI)

This paper demonstrates the application of gradient-based optimization methods to the minimal weight design optimization of rotor systems. A nonlinear constrained optimization problem is considered. Design variables are inner radii and wall thicknesses ... Keywords: Gradient projection method, Rotordynamics, Sequential quadratic programming, Sizing optimization, Turbine rotor

Alexander O. Pugachev

2013-06-01T23:59:59.000Z

379

MODELING TRANSPORT IN THE DOWN GRADIENT PORTION OF THE 200-PO-1 OPERABLE UNIT AT THE HANFORD SITE  

SciTech Connect

Remedial Investigations are underway for the 200-PO-l Operable Unit (OU) at the U.S. Department of Energy's Hanford Site in Washington State. To support the baseline risk assessment and evaluation of remedial alternatives, fate and transport modeling is being conducted to predict the future concentration of contaminants of potential concern in the 200-PO-1 OU. This study focuses on modeling the 'down gradient' transport of those contaminants that migrate beyond the 3-D model domain selected for performing detailed 'source area' modeling within the 200-PO-1 OU. The down gradient portion is defined as that region of the 200-PO-1 OU that is generally outside the 200 Area (considered 'source area') of the Hanford Site. A 1-D transport model is developed for performing down gradient contaminant fate and transport modeling. The 1-D transport model is deemed adequate based on the inferred transport pathway of tritium in the past and the observation that most of the contaminant mass remains at or near the water table within the unconfined aquifer of the Hanford Formation and the Cold-Creek/Pre-Missoula Gravel unit. The Pipe Pathway feature of the GoldSim software is used to perform the calculations. The Pipe Pathway uses a Laplace transform approach to provide analytical solutions to a broad range of advection-dominated mass transport systems involving one-dimensional advection, longitudinal dispersion, retardation, decay and ingrowth, and exchanges with immobile storage zones. Based on the historical concentration distribution data for the extensive tritium plume in this area, three Pipe Pathways are deemed adequate for modeling transport of contaminants. Each of these three Pipe Pathways is discretized into several zones, based on the saturated thickness variation in the unconfined aquifer and the location of monitoring wells used for risk assessment calculation. The mass fluxes of contaminants predicted to exit the source area model domain are used as an input to the down gradient model, while the flow velocities applied are based on the present-day hydraulic gradients and estimation of hydraulic conductivity in the unconfined aquifer. The results of the calculation indicate that the future concentrations of contaminants of potential concern in the down gradient portion of the 200-PO-1 OU declines with time and distance.

MEHTA S; ALY AH; MILLER CW; MAYENNA A

2009-12-03T23:59:59.000Z

380

Arsenic Speciation in Blue Mussels (Mytilus edulis) Along a Highly Contaminated Arsenic Gradient  

Science Conference Proceedings (OSTI)

Arsenic is naturally present in marine ecosystems, and these can become contaminated from mining activities, which may be of toxicological concern to organisms that bioaccumulate the metalloid into their tissues. The toxic properties of arsenic are dependent on the chemical form in which it is found (e.g., toxic inorganic arsenicals vs nontoxic arsenobetaine), and two analytical techniques, high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) and X-ray absorption spectroscopy (XAS), were used in the present study to examine the arsenic species distribution in blue mussels (Mytilus edulis) obtained from an area where there is a strong arsenic concentration gradient as a consequence of mining impacted sediments. A strong positive correlation was observed between the concentration of inorganic arsenic species (arsenic compounds with no As-C bonds) and total arsenic concentrations present in M. edulis tissues (R{sup 2} = 0.983), which could result in significant toxicological consequences to the mussels and higher trophic consumers. However, concentrations of organoarsenicals, dominated by arsenobetaine, remained relatively constant regardless of the increasing As concentration in M. edulis tissue (R{sup 2} = 0.307). XANES bulk analysis and XAS two-dimensional mapping of wet M. edulis tissue revealed the presence of predominantly arsenic-sulfur compounds. The XAS mapping revealed that the As(III)-S and/or As(III) compounds were concentrated in the digestive gland. However, arsenobetaine was found in small and similar concentrations in the digestive gland as well as the surrounding tissue suggesting arsenobetaine may being used in all of the mussel's cells in a physiological function such as an intracellular osmolyte.

Whaley-Martin, K.J.; Koch, I.; Moriarty, M.; Reimer, K.J. (Royal)

2012-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "ther mal gradients" 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

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

382

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

383

On Computation of the Design Function Gradient for the Sensor-Location Problem in Variational Data Assimilation  

Science Conference Proceedings (OSTI)

The optimal sensor-location problem is considered in the framework of variational data assimilation for a large-scale dynamical model governed by partial differential equations. This problem is formulated as an optimization problem for the design function ... Keywords: Lanczos method, design function gradient, large-scale flow models, limited-memory inverse Hessian, optimal experiment design, sensor-location problem, variational data assimilation

I. Yu. Gejadze; V. Shutyaev

2012-04-01T23:59:59.000Z

384

Laser-Doppler acoustic probing of granular media with in-depth property gradient and varying pore pressures  

Science Conference Proceedings (OSTI)

Non-contacting ultrasonic techniques recently proved to be efficient in the physical modeling of seismic-wave propagation at various application scales, as for instance in the context of geological analogue and seismic modeling. An innovative experimental set-up is proposed here to perform laser-Doppler acoustic probing of unconsolidated granular media with varying pore pressures. The preliminary experiments presented here provide reproducible results and exploitable data, thus validating both the proposed medium preparation and pressure gradient generation procedure.

Bodet, L.; Dhemaied, A.; Mourgues, R.; Tournat, V.; Rejiba, F. [LPG, UMR CNRS 6112, Universite du Maine, Le Mans (France); UMR CNRS 7619 Sisyphe, Universite Pierre et Marie Curie-Paris 6 (France); LPG, UMR CNRS 6112, Universite du Maine, Le Mans (France); LAUM, CNRS, Universite du Maine, Le Mans (France); UMR CNRS 7619 Sisyphe, Universite Pierre et Marie Curie-Paris 6 (France)

2012-05-24T23:59:59.000Z

385

Functional Conceptual Design Criteria - 5-MW/sub e/ salt-gradient solar pond power plant at Great Salt Lake  

DOE Green Energy (OSTI)

The purpose of this solar pond plant facility would be to provide valid data on the cost, operation, and reliability of salt-gradient solar ponds as a means of producing power. A general facility description is given which includes design code requirements, site selection, site characteristics, and site-specific design requirements. Functional requirements discussed include: civil-structural; mechanical; electrical; and control, instrumentation and alarms. Occupational and environmental safety, security, and quality assurance are also discussed.

Brown, L.M.; Barnhart, J.S.; Cavola, R.G.; Drost, M.K.; Hauser, S.G.; Johnson, B.M.

1983-08-01T23:59:59.000Z

386

Composition-tailored synthesis of gradient transition metal precursor particles for lithium-ion battery cathode materials.  

DOE Green Energy (OSTI)

We report the tailored synthesis of particles with internal gradients in transition metal composition aided by the use of a general process model. Tailored synthesis of transition metal particles was achieved using a coprecipitation reaction with tunable control over the process conditions. Gradients in the internal composition of the particles was monitored and confirmed experimentally by analysis of particles collected during regularly timed intervals. Particles collected from the reactor at the end of the process were used as the precursor material for the solid-state synthesis of Li{sub 1.2}(Mn{sub 0.62}Ni{sub 0.38}){sub 0.8}O{sub 2}, which was electrochemically evaluated as the active cathode material in a lithium battery. The Li{sub 1.2}(Mn{sub 0.62}Ni{sub 0.38}){sub 0.8}O{sub 2} material was the first example of a structurally integrated multiphase material with a tailored internal gradient in relative transition metal composition as the active cathode material in a lithium-ion battery. We believe our general synthesis strategy may be applied to produce a variety of new cathode materials with tunable interior, surface, and overall relative transition metal compositions.

Koenig, G. M.; Belharouak, I.; Deng, H.; Amine, K.; Sun, Y. K. (Chemical Sciences and Engineering Division)

2011-04-12T23:59:59.000Z

387

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

388

JOINT-INDUSTRY PARTNERSHIP TO DEVELOP A HOLLOW SPHERE DUAL-GRADIENT DRILLING SYSTEM  

Science Conference Proceedings (OSTI)

Maurer Technology Inc. (MTI) formed a joint-industry partnership to fund the development of a hollow sphere dual-gradient drilling (DGD) system. Phase I consisted of collecting, compiling, analyzing, and distributing information and data regarding a new DGD system for use by the oil and gas industry. Near the end of Phase I, DOE provided funding to the project that was used to conduct a series of critical follow-on tests investigating sphere separation in weighted waterbase and oilbase muds. Drilling costs in deep water are high because seawater pressure on the ocean floor creates a situation where many strings of casing are required due to the relatively close spacing between fracture and pore pressure curves. Approximately $100 million have been spent during the past five years on DGD systems that place pumps on the seafloor to reduce these drilling problems by reducing the annulus fluid pressure at the bottom of the riser. BP estimates that a DGD system can save $9 million per well in the Thunderhorse Field and Conoco estimates it can save $5 to $15 million per well in its deepwater operations. Unfortunately, previous DGD development projects have been unsuccessful due to the high costs ($20 to $50 million) and reliability problems with seafloor pump systems. MTI has been developing a simple DGD system concept that would pump hollow glass spheres into the bottom of the riser to reduce density of the mud in the riser. This eliminates the requirement for seafloor pumps and replaces them with low cost mud pumps, shale shakers, and other oilfield equipment that can be operated on the rig by conventional crews. A $1.8 million Phase I joint-industry project funded by five service companies and three operators showed that hollow spheres could be pumped well, but difficulties were encountered in separating the spheres from a polymer mud supplied by Halliburton due to the high viscosity of this mud at the low shear rates encountered on oilfield shale shaker screens. As a result, an excessive amount of this polymer mud flowed across the screen with the beads instead of through the screen. At the completion of the Phase I project, it was concluded that the hollow sphere system would not work effectively with the polymer mud tested. ExxonMobil and Shell engineers proposed that additional sphere separation tests needed to be conducted with weighted oilfield waterbase and oilbase muds to determine if the DGD system would work with these muds. The DOE agreed to provide a $200,000 grant for these tests. The DOE-funded tests, described in this report, showed that the spheres could be pumped with conventional oilfield centrifugal and triplex mud pumps and separated effectively from both oilfield waterbase and oilbase muds using conventional oilfield shale shakers and hydrocyclones. As a result of the success of these DOE tests, this DGD system is ready for full-scale field testing, first on land wells and later in the offshore environment. Maurer Technology Inc. is currently proposing a Phase II project to oil companies to further develop this DGD concept. This project would be funded by four to eight operators. If Phase II tests are successful, Noble plans to commercialize this system with a service company partner that will market and operate the DGD system on Noble's and other drilling contractors' rigs.

William C. Maurer; Colin Ruan; Greg Deskins

2003-05-01T23:59:59.000Z

389

The Effect of Basic-State Potential Vorticity Gradients on the Growth of Baroclinic Waves and the Height of the Tropopause  

Science Conference Proceedings (OSTI)

The stability characteristics of normal mode perturbations on idealized basic states that have meridional potential vorticity (PV) gradients that are zero in the troposphere, very large at the tropopause, and order ? in the stratosphere are ...

Nili Harnik; Richard S. Lindzen

1998-02-01T23:59:59.000Z

390

Compact X-ray Free Electron Laser from a Laser-plasma Accelerator using a Transverse Gradient Undulator  

SciTech Connect

Compact laser-plasma accelerators can produce high energy electron beams with low emittance, high peak current but a rather large energy spread. The large energy spread hinders the potential applications for coherent FEL radiation generation. In this paper, we discuss a method to compensate the effects of beam energy spread by introducing a transverse field variation into the FEL undulator. Such a transverse gradient undulator together with a properly dispersed beam can greatly reduce the effects of electron energy spread and jitter on FEL performance. We present theoretical analysis and numerical simulations for SASE and seeded extreme ultraviolet and soft x-ray FELs based on laser plasma accelerators.

Huang, Zhirong; Ding, Yuantao; /SLAC; Schroeder, Carl B.; /LBL, Berkeley

2012-09-13T23:59:59.000Z

391

Optimization and preconceptual design of a 5 MWe salt-gradient solar pond power plant at Great Salt Lake  

DOE Green Energy (OSTI)

The techniques used to optimize and design a solar salt-gradient pond (SSP) power plant for installation at the Great Salt Lake are described. The method and results of the site selection study are described as well as the characteristics of the selected site. The figure of merit used as well as the characteristics of the selected site. The figure of merit used in the optimization study, the general optimization approach, and the specific optimization method used for each subsystem are described. Results are then discussed of the optimization of the pond configuration, total system, and piping. Pond design and ground rule sensitivity studies are reported. (LEW)

Drost, M.K.; Brown, L.M.; Barnhart, J.S.; Cavola, R.G.; Hauser, S.G.; Johnson, B.M.

1983-05-01T23:59:59.000Z

392

Skyrme functional from a three-body pseudo-potential of second-order in gradients. Formalism for central terms  

E-Print Network (OSTI)

In one way or the other, all modern parametrizations of the nuclear energy density functional (EDF) do not respect the exchange symmetry associated with Pauli's principle. It has been recently shown that this practice jeopardizes multi-reference (MR) EDF calculations by contaminating the energy with spurious self-interactions that, for example, lead to finite steps or even divergences when plotting it as a function of collective coordinates. As of today, the only viable option to bypass these pathologies is to rely on EDF kernels that enforce Pauli's principle from the outset by strictly and exactly deriving from a genuine, i.e. density-independent, Hamilton operator. We wish to develop the most general Skyrme-like EDF parametrization containing linear, bilinear and trilinear terms in the density matrices with up to two gradients, under the key constraint that it derives strictly from an effective Hamilton operator. The most general three-body Skyrme-like pseudo-potential containing up to two gradient operators is constructed to generate the trilinear part. The present study is limited to central terms. Spin-orbit and tensor will be addressed in a forthcoming paper. (See paper for full abstract)

J. Sadoudi; T. Duguet; J. Meyer; M. Bender

2013-10-02T23:59:59.000Z

393

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

394

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

395

Transfer coefficients for the Gibbs surface in a two-phase mixture in the non-equilibrium square gradient model  

E-Print Network (OSTI)

In this paper we calculate the transfer coefficients for evaporation and condensation of mixtures. We use the continuous profiles of various thermodynamic quantities through the interface, obtained in our previous works using the square gradient model. Furthermore we introduce the Gibbs surface and obtain the excess entropy production for a surface. Following the traditional non-equilibrium thermodynamic approach we introduce the surface transfer coefficients which we are able to determine from the continuous solution. The knowledge of these coefficients is important for many industrial applications which involve transport through a surface, such as for instance distillation. In our approach the values of the local resistivities in the liquid and the vapor phases are chosen on the basis of experimental values. In the interfacial region there are small peaks in these resistivities. Three amplitudes control the magnitude of these peaks. Possible values of these amplitudes are found by matching the diagonal transfer coefficients to values predicted by kinetic theory. Using these amplitudes we find that the value of the cross resistivities is 1-2 orders of magnitude higher then the one from kinetic theory. The results of both kinetic theory and molecular dynamics simulations support the existence of small peaks in the local resistivities in the interfacial region. The square gradient approach gives an independent way to determine the transfer coefficients for surfaces. The results indicate that kinetic theory underestimates the interfacial transfer coefficients in real fluids.

K. S. Glavatskiy; D. Bedeaux

2009-07-11T23:59:59.000Z

396

Potential net soil N mineralization and decomposition of glycine-13C in forest soils along an elevation gradient  

SciTech Connect

The objective of this research was to better understand patterns of soil nitrogen (N) availability and soil organic matter (SOM) decomposition in forest soils across an elevation gradient (235-1670 m) in the southern Appalachian Mountains. Laboratory studies were used to determine the potential rate of net soil N mineralization and in situ studies of {sup 13}C-labelled glycine were used to infer differences in decomposition rates. Nitrogen stocks, surface soil (0-5 cm) N concentrations, and the pool of potentially mineralizable surface soil N tended to increase from low to high elevations. Rates of potential net soil N mineralization were not significantly correlated with elevation. Increasing soil N availability with elevation is primarily due to greater soil N stocks and lower substrate C-to-N ratios, rather than differences in potential net soil N mineralization rates. The loss rate of {sup 13}C from labelled soils (0-20 cm) was inversely related to study site elevation (r = -0.85; P < 0.05) and directly related to mean annual temperature (+0.86; P<0.05). The results indicated different patterns of potential net soil N mineralization and {sup 13}C loss along the elevation gradient. The different patterns can be explained within a framework of climate, substrate chemistry, and coupled soil C and N stocks. Although less SOM decomposition is indicated at cool, high-elevation sites, low substrate C-to-N ratios in these N-rich systems result in more N release (N mineralization) for each unit of C converted to CO{sub 2} by soil microorganisms.

Garten Jr, Charles T [ORNL

2004-09-01T23:59:59.000Z

397

COMPLEX STRUCTURE IN CLASS 0 PROTOSTELLAR ENVELOPES. III. VELOCITY GRADIENTS IN NON-AXISYMMETRIC ENVELOPES, INFALL, OR ROTATION?  

SciTech Connect

We present an interferometric kinematic study of morphologically complex protostellar envelopes based on observations of the dense gas tracers N{sub 2}H{sup +} and NH{sub 3}. The strong asymmetric nature of most envelopes in our sample leads us to question the common interpretation of velocity gradients as rotation, given the possibility of projection effects in the observed velocities. Several 'idealized' sources with well-ordered velocity fields and envelope structures are now analyzed in more detail. We compare the interferometric data to position-velocity (PV) diagrams of kinematic models for spherical rotating collapse and filamentary rotating collapse. For this purpose, we developed a filamentary parameterization of the rotating collapse model to explore the effects of geometric projection on the observed velocity structures. We find that most envelopes in our sample have PV structures that can be reproduced by an infalling filamentary envelope projected at different angles within the plane of the sky. The infalling filament produces velocity shifts across the envelope that can mimic rotation, especially when viewed at single-dish resolutions and the axisymmetric rotating collapse model does not uniquely describe any data set. Furthermore, if the velocities are assumed to reflect rotation, then the inferred centrifugal radii are quite large in most cases, indicating significant fragmentation potential or more likely another component to the line-center velocity. We conclude that ordered velocity gradients cannot be interpreted as rotation alone when envelopes are non-axisymmetric and that projected infall velocities likely dominate the velocity field on scales larger than 1000 AU.

Tobin, John J.; Hartmann, Lee; Bergin, Edwin [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Chiang, Hsin-Fang; Looney, Leslie W. [Department of Astronomy, University of Illinois at Champaign/Urbana, Urbana, IL 61801 (United States); Chandler, Claire J. [National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States); Maret, Sebastien [UJF-Grenoble 1/CNRS-INSU, Institut de Planetologie et d'Astrophysique de Grenoble (IPAG) UMR 5274, Grenoble F-38041 (France); Heitsch, Fabian, E-mail: jtobin@nrao.edu [Department of Astronomy, University of North Carolina, Chapel Hill, NC (United States)

2012-03-20T23:59:59.000Z

398

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

399

Comparing the performance of neural networks developed by using Levenberg-Marquardt and Quasi-Newton with the gradient descent algorithm for modelling a multiple response grinding process  

Science Conference Proceedings (OSTI)

Monitoring and control of multiple process quality characteristics (responses) in grinding plays a critical role in precision parts manufacturing industries. Precise and accurate mathematical modelling of multiple response process behaviour holds the ... Keywords: Back propagation neural network, Gradient descent algorithm, Levenberg-Marquardt algorithm, Multiple response, Quasi-Newton algorithm

Indrajit Mukherjee; Srikanta Routroy

2012-02-01T23:59:59.000Z

400

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

Note: This page contains sample records for the topic "ther mal gradients" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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401

Large Amplitude Spatial and Temporal Gradients in Atmospheric Boundary Layer CO2 Mole Fractions Detected With a Tower-Based Network in the U.S. Upper Midwest  

Science Conference Proceedings (OSTI)

This study presents observations of atmospheric CO{sub 2} mole fraction from a nine-tower, regional network deployed during the North American Carbon Program's Mid-Continent Intensive during 2007-2009. Within this network in a largely agricultural area, mean atmospheric CO{sub 2} gradients were strongly correlated with both ground-based inventory data and estimates from satellite remote sensing. The average seasonal drawdown for corn-dominated sites (35 ppm) is significantly larger than has been observed at other continental boundary layer sites. Observed growing-season median CO{sub 2} gradients are strongly dependent on local flux. The gradients between cross-vegetation site-pairs, for example, average 2.0 ppm/100 km, four times larger than the similar-vegetation site-pair average. Daily-timescale gradients are as large as 5.5 ppm/100 km, but dominated by advection rather than local flux. Flooding in 2008 led to a region-wide 23 week delay in growing-season minima. The observations show that regional-scale CO{sub 2} mole fraction networks yield large, coherent signals governed largely by regional sources and sinks of CO{sub 2}.

Miles, Natasha; Richardson, S. J.; Davis, Kenneth J.; Lauvaux, Thomas; Andrews, A.; West, Tristram O.; Bandaru, Varaprasad; Crosson, Eric R.

2012-02-21T23:59:59.000Z

402

WATER RESOURCES RESEARCH, VOL. 24, NO. 8, PAGES 1345-1359, AUGUST 1988 Gradient Dynamic Programming for StochasticOptimal Control  

E-Print Network (OSTI)

water quality maintenance in rivers [e.g., Dracupand Fogarty, 1974; Changand Yeh, 1973], to mention only programming ap- plicationsin water resourcescan be found in the works by Yakowitz [1982] and Yeh [1985WATER RESOURCES RESEARCH, VOL. 24, NO. 8, PAGES 1345-1359, AUGUST 1988 Gradient Dynamic Programming

Foufoula-Georgiou, Efi

403

Inner shelf response to cross-shelf wind stress: the importance of the cross-shelf density gradient in an idealized numerical model and field observations  

Science Conference Proceedings (OSTI)

This study investigates the effects of horizontal and vertical density gradients on the inner shelf response to cross-shelf wind stress by using an idealized numerical model and observations from a moored array deployed south of Marthas Vineyard, ...

Rachel Horwitz; Steven J. Lentz

404

3D joint inversion of gradient and total-field magnetic data Kristofer Davis and Yaoguo Li, Center for Gravity, Electrical, and Magnetics, Colorado School of Mines, Golden,  

E-Print Network (OSTI)

field and the derivative of its source to relate both data sets to a common source distribution. Our (Nelson, 1988) as well as enhancing the conventional gridding of total-field data by creating pseudo for the total-field and gradient data using a common 3D source distribution based on relationship between

405

Programmed improvements of the alternating gradient synchrotron complex at Brookhaven National Laboratory, Upton, New York. Environmental assessment  

SciTech Connect

The purpose and need for DOE to undertake the actions described in this document are to improve the efficiency of the Alternating Gradient Synchrotron (AGS) complex. Benefits would include optimization of the AGS scientific program, increased high-energy and nuclear physics experimentation, improved health and safety conditions for workers and users, reduced impact on the environment and the general public, energy conservation, decreased generation of hazardous and radioactive wastes, and completion of actions required to permit the AGS to be the injector to the Relativistic Heavy Ion Collider (RHIC)., Improved efficiency is defined as increasing the AGS`s capabilities to capture and accelerate the proton intensity transferred to the AGS from the AGS booster. Improved capture of beam intensity would reduce the beam losses which equate to lost scientific opportunity for study and increased potential for radiation doses to workers and the general public. The action would also refurbish magnets used in the transfer tunnel which connects the AGS complex to RHIC to permit smooth injection of beam into the RHIC accelerator. These magnets were previously used to direct beam to fixed targets for high energy physics studies but have hot received proper maintenance to be reliable as injectors to RHIC. The document describes alternative actions, the affected environment, and environmental impacts.

NONE

1994-03-01T23:59:59.000Z

406

LITTORAL DRIFT GRADIENT  

Science Conference Proceedings (OSTI)

Classification of Coasts (see Holocene Coastal Geomorphology). Climate Patterns in the Coastal Zone. Coasts, Coastlines, Shores, and Shorelines. Coral Reefs.

407

GRADIENT ELUTION MOVING BOUNDARY ...  

Science Conference Proceedings (OSTI)

... LA Lewis and JJ Opplt. CRC Handbook of Electrophoresis: Lipoproteins: Basic Principles and Concepts, Boca Raton:CRC Press, 1979. Page 12. ...

2010-07-27T23:59:59.000Z

408

Gradient index retroreflector  

DOE Patents (OSTI)

A retroreflector is formed of a graded index lens and a reflective coating at one end. The lens has a length of an odd multiple of a quarter period thereof. Hexagonally shaped graded index lenses may be closely packed in an array to form a retroreflecting surface.

Layne, C.B.

1986-03-06T23:59:59.000Z

409

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

410

[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

411

[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

412

Design of Air-cooled Microchannel Condensers for Mal-distributed Air Flow Conditions .  

E-Print Network (OSTI)

??Air-cooled condensers are routinely designed for a variety of applications, including residential air-conditioning systems. Recent attempts at improving the performance of these heat exchangers have (more)

Subramaniam, Vishwanath

2004-01-01T23:59:59.000Z

413

Electron cyclotron maser emission mode coupling to the z-mode on a longitudinal density gradient in the context of solar type III bursts  

SciTech Connect

A beam of super-thermal, hot electrons was injected into maxwellian plasma with a density gradient along a magnetic field line. 1.5D particle-in-cell simulations were carried out which established that the EM emission is produced by the perpendicular component of the beam injection momentum. The beam has a positive slope in the distribution function in perpendicular momentum phase space, which is the characteristic feature of a cyclotron maser. The cyclotron maser in the overdense plasma generates emission at the electron cyclotron frequency. The frequencies of generated waves were too low to propagate away from the injection region, hence the wavelet transform shows a pulsating wave generation and decay process. The intensity pulsation frequency is twice the relativistic cyclotron frequency. Eventually, a stable wave packet formed and could mode couple on the density gradient to reach frequencies of the order of the plasma frequency that allowed for propagation. The emitted wave is likely to be a z-mode wave. The total electromagnetic energy generated is of the order of 0.1% of the initial beam kinetic energy. The proposed mechanism is of relevance to solar type III radio bursts, as well as other situations, when the injected electron beam has a non-zero perpendicular momentum, e.g., magnetron.

Pechhacker, R.; Tsiklauri, D. [School of Physics and Astronomy, Queen Mary University of London, London E1 4NS (United Kingdom)

2012-11-15T23:59:59.000Z

414

E&PFocus  

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

advances, higher oil prices, advances, higher oil prices, reduced costs, and environmental needs have aligned to create a "perfect storm" of growth opportunity for a well-established method for enhancing oil recovery (EOR) in the U.S.: carbon dioxide (CO 2 ) flooding. The U.S. Department of Energy is sup- porting critical research to help America's oil producers take full advantage of that growth opportunity (see table on p. 3). CO 2 flooding is the fastest-growing EOR technique in the U.S. While production vol- umes and the number of projects for ther- mal, chemical, and other EOR processes have fallen off sharply since 1980, the num- ber of CO 2 projects has more than tripled, to more than 70 projects as of yearend 2004. Meanwhile, CO 2 production volumes have jumped twentyfold since the early 1980s

415

C:\ANNUAL\VENTCHAP.V8\NGAla1109.vp  

Gasoline and Diesel Fuel Update (EIA)

215 215 Energy Information Administration / Natural Gas Annual 2000 Metric and Thermal Conversion Tables Metric Conversions Table B1 presents Summary Statistics for Natural Gas in the United States for 1996 through 2000 in metric units of mea- sure. Volumes are shown in cubic meters instead of cubic feet. Prices are shown in dollars per thousand cubic meters instead of dollars per thousand cubic feet. The data in this ta- ble have been converted from the data that appear in Table 1 of this report. Thermal Conversions Table B2 presents the thermal (Btu) conversion factors and the converted data for natural gas supply and disposition from 1996 through 2000. A brief documentation for the ther- mal conversion factors follows: · Marketed Production. The conversion factor is calcu- lated by adding the total heat content of dry production to the total heat content of extraction loss and dividing

416

Monthly Energy Review - November 2000  

Gasoline and Diesel Fuel Update (EIA)

November 2000 November 2000 www.eia.doe.gov Energy Information Administration On the Web at: www.eia.doe.gov/mer Monthly Energy Review The Monthly Energy Review (MER) presents an overview of the Energy Information Administration's recent monthly energy statistics. The statisti cs cover the major activities of U.S. production, consumption, trade, stocks, and prices for petroleum, natural gas, coal, electricity, and nuclear energy. Also included are international energy and ther- mal and metric conversion factors. Publication of this report is in keeping with responsibilities given to the Energy Information Administration (EIA) in Public Law 95-91 (Department of Energy Organization Act), which states, in part, in Section 205(a)(2), that: The MER is intended for use by Members of Congress, Federal and State agencies, energy analysts, and the general public. EIA welcomes

417

C:\ANNUAL\VENTCHAP.V8\NGA.VP  

Gasoline and Diesel Fuel Update (EIA)

Workmen Workmen adjust valves on a Panhandle Eastern pipeline. Energy Information Administration / Natural Gas Annual 1997 237 Metric and Thermal Conversion Tables Metric Conversions Table B1 presents Summary Statistics for Natural Gas in the United States for 1993 through 1997 in metric units of mea- sure. Volumes are shown in cubic meters instead of cubic feet. Prices are shown in dollars per thousand cubic meters instead of dollars per thousand cubic feet. The data in this ta- ble have been converted from the data that appear in Table 1 of this report. Thermal Conversions Table B2 presents the thermal (Btu) conversion factors and the converted data for natural gas supply and disposition from 1993 through 1997. A brief documentation for the ther- mal conversion factors follows: · Marketed Production. The conversion factor is calcu- lated by adding the total heat content of dry production

418

C:\ANNUAL\VENTCHAP.V8\NewNGA02.vp  

Gasoline and Diesel Fuel Update (EIA)

184 184 Energy Information Administration / Natural Gas Annual 2001 Metric and Thermal Conversion Tables Metric Conversions Table B1 presents Summary Statistics for Natural Gas in the United States for 1997 through 2001 in metric units of mea- sure. Volumes are shown in cubic meters instead of cubic feet. Prices are shown in dollars per thousand cubic meters instead of dollars per thousand cubic feet. The data in this ta- ble have been converted from the data that appear in Table 1 of this report. Thermal Conversions Table B2 presents the thermal (Btu) conversion factors and the converted data for natural gas supply and disposition from 1997 through 2001. A brief documentation for the ther- mal conversion factors follows: · Marketed Production. The conversion factor is calcu- lated by adding the total heat content of dry production to the total heat content of extraction loss and dividing

419

C:\Annual\VENTCHAP.V8\NGA02.vp  

Gasoline and Diesel Fuel Update (EIA)

66 66 Energy Information Administration / Natural Gas Annual 2002 Metric and Thermal Conversion Tables Metric Conversions Table B1 presents Summary Statistics for Natural Gas in the United States for 1998 through 2002 in metric units of mea- sure. Volumes are shown in cubic meters instead of cubic feet. Prices are shown in dollars per thousand cubic meters instead of dollars per thousand cubic feet. The data in this ta- ble have been converted from the data that appear in Table 1 of this report. Thermal Conversions Table B2 presents the thermal (Btu) conversion factors and the converted data for natural gas supply and disposition from 1998 through 2002. A brief documentation for the ther- mal conversion factors follows: · Marketed Production. The conversion factor is calcu- lated by adding the total heat content of dry production to the total heat content of extraction loss and dividing

420

NGA98fin5.vp  

Gasoline and Diesel Fuel Update (EIA)

An An overhead pipeline crossing on the White River near Newport, Arkansas. 237 Energy Information Administration / Natural Gas Annual 1998 Metric and Thermal Conversion Tables Metric Conversions Table B1 presents Summary Statistics for Natural Gas in the United States for 1994 through 1998 in metric units of mea- sure. Volumes are shown in cubic meters instead of cubic feet. Prices are shown in dollars per thousand cubic meters instead of dollars per thousand cubic feet. The data in this ta- ble have been converted from the data that appear in Table 1 of this report. Thermal Conversions Table B2 presents the thermal (Btu) conversion factors and the converted data for natural gas supply and disposition from 1994 through 1998. A brief documentation for the ther- mal conversion factors follows: · Marketed Production. The conversion factor is calcu- lated by adding the total heat content

Note: This page contains sample records for the topic "ther mal gradients" 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

LINE-REVERSAL MEASUREMENTS OF EXCITATION AND ELECTRON TEMPERATURE IN A SHOCK TUBE  

E-Print Network (OSTI)

The spectral line-reversal method has been applied to determine population-temperatures within an (argon-calcium) plasma, generated by a reflected aerodynamic shock. The measurements have been made simultaneously on (a) normal bound-bound Ca 1 lines, (b) lines involving strongly auto-ionizing levels. The agreement of the two sets of values identifies the electron-temperature with the temperature characterizing the populations of the bound excited-states, giving improved confidence in the existence of complete ther-mal equilibrium in the reflected shock. The spectral-line reversal method has been previously applied to transitions between normal bound electronic states of neutral atoms, ions or molecules, (Gaydon and Hurle 1963; Charatis and Wilkerson 1962; Parkinson and Reeves 1964). The

W. R. S. Garton; W. H. Parkinson; E. M. Reeves

1965-01-01T23:59:59.000Z

422

An nual En ergy Re view 2001  

Gasoline and Diesel Fuel Update (EIA)

An nual En ergy Re view 2001 An nual En ergy Re view 2001 The An nual En ergy Re view (AER) pres ents the En ergy In for ma tion Ad min - is tra tion's his tor i cal en ergy sta tis tics. For many se ries, sta tis tics are given for ev ery year from 1949 through 2001. The sta tis tics, ex pressed in ei ther phys i cal units or Brit ish ther mal units, cover all ma jor en ergy ac tiv i ties, in - clud ing con sump tion, pro duc tion, trade, stocks, and prices, for all ma jor en - ergy com mod i ties, in clud ing fos sil fu els, elec tric ity, and re new able en ergy sources. Pub li ca tion of this re port is re quired un der Pub lic Law 95-91 (De part ment of En ergy Or ga ni za tion Act), Sec tion 205(c), and is in keep ing with re spon - si bil i ties given to the En ergy In for ma tion Ad min is tra tion un der Sec tion

423

Stability of critical bubble in stretched fluid of square-gradient density-functional model with triple-parabolic free energy  

E-Print Network (OSTI)

The square-gradient density-functional model with triple-parabolic free energy, that was used previously to study the homogeneous bubble nucleation [J. Chem. Phys. 129, 104508 (2008)], is used to study the stability of the critical bubble nucleated within the bulk under-saturated stretched fluid. The stability of the bubble is studied by solving the Schr\\"odinger equation for the fluctuation. The negative eigenvalue corresponds to the unstable growing mode of the fluctuation. Our results show that there is only one negative eigenvalue whose eigenfunction represents the fluctuation that corresponds to the isotropically growing or shrinking nucleus. In particular, this negative eigenvalue survives up to the spinodal point. Therefore the critical bubble is not fractal or ramified near the spinodal.

Masao Iwamatsu; Yutaka Okabe

2010-06-11T23:59:59.000Z

424

Mindlin second-gradient elastic properties from dilute two-phase Cauchy-elastic composites Part II: Higher-order constitutive properties and application cases  

E-Print Network (OSTI)

Starting from a Cauchy elastic composite with a dilute suspension of randomly distributed inclusions and characterized at first-order by a certain discrepancy tensor (see part I of the present article), it is shown that the equivalent second-gradient Mindlin elastic solid: (i.) is positive definite only when the discrepancy tensor is negative defined; (ii.) the non-local material symmetries are the same of the discrepancy tensor, and (iii.) the nonlocal effective behaviour is affected by the shape of the RVE, which does not influence the first-order homogenized response. Furthermore, explicit derivations of non-local parameters from heterogeneous Cauchy elastic composites are obtained in the particular cases of: (a) circular cylindrical and spherical isotropic inclusions embedded in an isotropic matrix, (b) n-polygonal cylindrical voids in an isotropic matrix, and (c) circular cylindrical voids in an orthortropic matrix.

Bacca Mattia; Bigoni Davide; Dal Corso Francesco; Veber Daniele

2013-05-10T23:59:59.000Z

425

PRESENTED AT THE 1  

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

r i b u t a b l e t o the movement of e l e c t r o n s and ions through a t h e r - mal gradient under t h e i n f l u e n c e o f a v o l t a g e drop. Since 5 + S* T ( t o t...

426

Linear electric field frequency shift (important for next generation electric dipole moment searches) induced in confined gases by a magnetic field gradient  

E-Print Network (OSTI)

The search for particle electric dipole moments (edm) represents a most promising way to search for physics beyond the standard model. A number of groups are planning a new generation of experiments using stored gases of various kinds. In order to achieve the target sensitivities it will be necessary to deal with the systematic error resulting from the interaction of the well-known $\\overrightarrow{v}\\times \\overrightarrow{E}$ field with magnetic field gradients (often referred to as the geometric phase effect (Commins, ED; Am. J. Phys. \\QTR{bf}{59}, 1077 (1991), Pendlebury, JM \\QTR{em}{et al;} Phys. Rev. \\QTR{bf}{A70}, 032102 (2004)). This interaction produces a frequency shift linear in the electric field, mimicking an edm. In this work we introduce an analytic form for the velocity auto-correlation function which determines the velocity-position correlation function which in turn determines the behavior of the frequency shift (Lamoreaux, SK and Golub, R; Phys. Rev \\QTR{bf}{A71}, 032104 (2005)) and show how it depends on the operating conditions of the experiment. We also discuss some additional issues.

Authors A. L. Barabanov; R. Golub; S. K. Lamoreaux

2006-07-17T23:59:59.000Z

427

Critical cavity in the stretched fluid studied using square-gradient density-functional model with triple-parabolic free energy  

E-Print Network (OSTI)

The generic square-gradient density-functional model with triple-parabolic free energy is used to study the stability of a cavity introduced into the stretched liquid. The various properties of the critical cavity, which is the largest stable cavity within the liquid, are compared with those of the critical bubble of the homogeneous bubble nucleation. It is found that the size of the critical cavity is always smaller than that of the critical bubble, while the work of formation of the former is always higher than the latter in accordance with the conjectures made by Punnathanam and Corti [J. Chem. Phys. {\\bf 119}, 10224 (2003)] deduced from the Lennard-Jones fluids. Therefore their conjectures about the critical cavity size and the work of formation would be more general and valid even for other types of liquid such as metallic liquid or amorphous. However, the scaling relations they found for the critical cavity in the Lennard-Jones fluid are marginally satisfied only near the spinodal.

Masao Iwamatsu

2009-04-04T23:59:59.000Z

428

Self-diffusion measurements of methanol and 1-decanol in supercritical CO{sub 2} by {sup 13}C pulsed field gradient NMR  

DOE Green Energy (OSTI)

A small amount of a highly polar compound, such as methanol, is frequently added to supercritical fluid (SCF) carbon dioxide to enhance its ability to dissolve polar molecules in SCF separation technology. Few diffusion coefficients in SCF mixtures have been reported in the literature. The pulsed field gradient spin-echo technique (PGSE) has been used extensively to measure self-diffusion in neat monohydric alcohols under pressure. Hurle et al. and Luedemann et al. showed that the experimental diffusion coefficients of methanol may be explained by a rough hard-sphere model (RHS) with a roughness parameter, A. In this paper, diffusion measurements are reported for CO{sub 2}-methanol and CO{sub 2}-decanol mixtures in supercritical fluids. Since methanol in CO{sub 2} is primarily monomeric at low concentration, the RHS model, that is accurate for most simple, non-associated liquids, should apply. Previous nuclear spin-lattice relaxation studies in SCF CO{sub 2} suggest a large local solvent density enhancement, or solvent clustering, near a alcohol solute molecule under SCF conditions. If solvent clustering occurs in the vicinity of alcohol solute molecules, it should affect the diffusion coefficients. The authors have made the requisite measurements and found that they corroborate their previous spin-relaxation data.

Bai, S.; Mayne, C.L.; Grant, D.M. [Univ. of Utah, Salt Lake City, UT (United States). Dept. of Chemistry; Taylor, C.M.V. [Los Alamos National Lab., NM (United States). Organic Analytical Chemistry Group

1997-10-01T23:59:59.000Z

429

COMPUTATIONAL COMPLEXITY OF INEXACT GRADIENT ...  

E-Print Network (OSTI)

leads to error estimates on the amount of constraint violation and the cost of primal ...... 80EU/2010); Sectoral Operational Programme Human Resources...

430

MODELLING TROPOSPHERIC GRADIENTS AND PARAMETERS  

E-Print Network (OSTI)

with microfibrillated cellulose (MFC) for structural insulating foams, April 22, 2012. 11. University of Maine Student Guard Station New Haven West, Christopher H. $9,500.00 1/26/2012 Development of W2-Multidirectional

Schuh, Harald

431

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 (20012004) 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

432

Experimental determination of the radial dose distribution in high gradient regions around {sup 192}Ir wires: Comparison of electron paramagnetic resonance imaging, films, and Monte Carlo simulations  

SciTech Connect

Purpose: The experimental determination of doses at proximal distances from radioactive sources is difficult because of the steepness of the dose gradient. The goal of this study was to determine the relative radial dose distribution for a low dose rate {sup 192}Ir wire source using electron paramagnetic resonance imaging (EPRI) and to compare the results to those obtained using Gafchromic EBT film dosimetry and Monte Carlo (MC) simulations. Methods: Lithium formate and ammonium formate were chosen as the EPR dosimetric materials and were used to form cylindrical phantoms. The dose distribution of the stable radiation-induced free radicals in the lithium formate and ammonium formate phantoms was assessed by EPRI. EBT films were also inserted inside in ammonium formate phantoms for comparison. MC simulation was performed using the MCNP4C2 software code. Results: The radical signal in irradiated ammonium formate is contained in a single narrow EPR line, with an EPR peak-to-peak linewidth narrower than that of lithium formate ({approx}0.64 and 1.4 mT, respectively). The spatial resolution of EPR images was enhanced by a factor of 2.3 using ammonium formate compared to lithium formate because its linewidth is about 0.75 mT narrower than that of lithium formate. The EPRI results were consistent to within 1% with those of Gafchromic EBT films and MC simulations at distances from 1.0 to 2.9 mm. The radial dose values obtained by EPRI were about 4% lower at distances from 2.9 to 4.0 mm than those determined by MC simulation and EBT film dosimetry. Conclusions: Ammonium formate is a suitable material under certain conditions for use in brachytherapy dosimetry using EPRI. In this study, the authors demonstrated that the EPRI technique allows the estimation of the relative radial dose distribution at short distances for a {sup 192}Ir wire source.

Kolbun, N.; Leveque, Ph.; Abboud, F.; Bol, A.; Vynckier, S.; Gallez, B. [Biomedical Magnetic Resonance Unit, Louvain Drug Research Institute, Universite catholique de Louvain, Avenue Mounier 73.40, B-1200 Brussels (Belgium); Molecular Imaging and Experimental Radiotherapy Unit, Institute of Experimental and Clinical Research, Universite catholique de Louvain, Avenue Hippocrate 55, B-1200 Brussels (Belgium); Biomedical Magnetic Resonance Unit, Louvain Drug Research Institute, Universite catholique de Louvain, Avenue Mounier 73.40, B-1200 Brussels (Belgium)

2010-10-15T23:59:59.000Z

433

Op%mal Scheduling of Combined Heat and Power (CHP) Plants1 under Time-sensi%ve Electricity Prices  

E-Print Network (OSTI)

) Co-genera8on of electricity and heat Storage Microgrids2 1. "Systema%c u. A microgrid refers to a "local grid" that can work autonomously from the central

Grossmann, Ignacio E.

434

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 ?? 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

435

Detailed discussion of a linear electric field frequency shift (important for next generation) electric dipole moment searches) induced in confined gases by a magnetic field gradient: Implications for electric dipole moment experiments (II)  

E-Print Network (OSTI)

The search for particle electric dipole moments represents a most promising way to search for physics beyond the standard model. A number of groups are planning a new generation of experiments using stored gases of various kinds. In order to achieve the target sensitivities it will be necessary to deal with the systematic error resulting from the interaction of the well-known E x v field with magnetic field gradients (often referred to as the geometric phase effect [9,10]). This interaction produces a frequency shift linear in the electric field, mimicking an edm. In this work we introduce an analytic model for the correlation function which determines the behavior of the frequency shift [11], and show in detail how it depends on the operating conditions of the experiment. We also propose a method to directly measure ths correlation function under the exact conditions of a given experiment.

A. L. Barabanov; R. Golub; S. K. Lamoreaux

2005-12-08T23:59:59.000Z

436

USING SIMPLEX GRADIENTS OF NONSMOOTH FUNCTIONS IN ...  

E-Print Network (OSTI)

provided by AFORS F49620-01-1-0013, The Boeing Company, and ExxonMobil Upstream Research. Company. . Departamento de Matemtica, Universidade...

437

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

438

On numerical analysis of conjugate gradient method  

Science Conference Proceedings (OSTI)

Z.I. WO~NICKI. InsLitute of Atomic Energy, ... experiments on test examples representative for nuclear engineering problems. .... negative splitting theory [3].

439

A GLOBALLY CONVERGENT MODIFIED CONJUGATE-GRADIENT ...  

E-Print Network (OSTI)

this algorithm, a preconditioner is used to increase the rate of convergence when near a minimizer. We have found that though a majority of the unconstrained...

440

A Perturbed Gradient Algorithm in Hilbert spaces  

E-Print Network (OSTI)

in this area is the paper [Yin and Zhu, 1990], showing the convergence and giving ... paper [Chen and White, 2002] provides a good understanding of infinite

Note: This page contains sample records for the topic "ther mal gradients" 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

Incremental Accelerated Gradient Methods for SVM Classification ...  

E-Print Network (OSTI)

Vector Machines, Proceedings of the 2010 IEEE International Conference on Data. Mining, pp. 679-688, IEEE Computer Society, Washington, DC, USA, 2010.

442

Optimization Online - An adaptive accelerated proximal gradient ...  

E-Print Network (OSTI)

Apr 5, 2013 ... In case the strong convexity parameter is unknown, we also develop an adaptive scheme that can automatically estimate it on the fly, at the cost...

443

USING INEXACT GRADIENTS IN A MULTILEVEL OPTIMIZATION ...  

E-Print Network (OSTI)

materials, Tech. Report 2011-9036, Sandia National Laboratories, Albuquerque NM and. Livermore CA, December 2011. [2] P. T. Boggs and J. John E. Dennis,...

444

Strain and Dislocation Gradients from Microdiffraction I  

Science Conference Proceedings (OSTI)

Feb 15, 2010 ... The engineering diffractometer VULCAN at the SNS started commissioning since June 26th in 2009. This instrument is designed for materials...

445

Strain and Dislocation Gradients from Microdiffraction II  

Science Conference Proceedings (OSTI)

Feb 17, 2010... testing, providing a direct link between the evolving microstructure and the ... Heating of metals under continuous load drives the observation through .... Alloy 600 has been used as the primary steam generator (SG) tubing...

446

Gradient based variable forgetting factor RLS algorithm  

Science Conference Proceedings (OSTI)

An accurate new variable forgetting factor recursive least-square adaptive algorithm is derived. An improved mean square behaviour analysis is presented, which shows that the theoretical analysis and the simulation results are close to each other. The ... Keywords: RLS algorithm, adaptive filters, variable forgetting factor

C. F. So; S. C. Ng; S. H. Leung

2003-06-01T23:59:59.000Z

447

Inexact projected gradient method for vector optimization  

E-Print Network (OSTI)

For orders induced by different cones, the vector optimization problem does not arise as frequently as the one concerning the point-wise partial order. However...

448

CONJUGATE GRADIENT WITH SUBSPACE OPTIMIZATION 1 ...  

E-Print Network (OSTI)

complexity bound of O(?L/l log(1/?)), where the ratio L/l characterizes the ...... mentation of the algorithm; instead we gather the values of ? and study their trend

449

Alternating Proximal Gradient Method for Convex Minimization ...  

E-Print Network (OSTI)

Sep 9, 2012 ... ??,S? ? log det(S), gives the maximum likelihood estimation of the ...... alternating direction method of multipliers, Foundations and Trends in...

450

Gradient projection anti-windup scheme  

E-Print Network (OSTI)

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

Teo, Chun Sang Justin

2011-01-01T23:59:59.000Z

451

Revisiting TCP congestion control using delay gradients  

Science Conference Proceedings (OSTI)

Traditional loss-based TCP congestion control (CC) tends to induce high queuing delays and perform badly across paths containing links that exhibit packet losses unrelated to congestion. Delay-based TCP CC algorithms infer congestion from delay measurements ...

David A. Hayes; Grenville Armitage

2011-05-01T23:59:59.000Z

452

On the Convergence of Decentralized Gradient Descent  

E-Print Network (OSTI)

?K. Yuan and Q. Ling are with Department of Automation, University of Science and .... for applications where data are collected by and stored in distributed agents, ... 21, 24, 33], multivehicle and multirobot networks [4, 23, 34], smart grids

453

Monthly Energy Review - January 2001  

Gasoline and Diesel Fuel Update (EIA)

January January 2001 www.eia.doe.gov Energy Information Administration On the Web at: www.eia.doe.gov/mer E n e r g y P l u g : E n e r g y E d u c a t i o n R e s o u r c e s M o r e o n R e n e w a b l e E n e r g y ( S e e N e w A p p e n d i x E ) Monthly Energy Review The Monthly Energy Review (MER) presents an overview of the Energy Information Administration's recent monthly energy statistics. The statistics cover the major activities of U.S. production, consumption, trade, stocks, and prices for petroleum, natural gas, coal, electricity, and nuclear energy. Also included are international energy and ther- mal and metric conversion factors. Publication of this report is in keeping with responsibilities given to the Energy Information Administration (EIA) in Public Law 95-91 (Department of Energy Organization Act), which states, in part, in Section 205(a)(2), that: The MER is intended for use by Members of Congress, Federal

454

Dynamic thermal management in chip multiprocessor systems  

E-Print Network (OSTI)

Recently, processor power density has been increasing at an alarming rate result- ing in high on-chip temperature. Higher temperature increases current leakage and causes poor reliability. In our research, we rst propose a Predictive Dynamic Ther- mal Management (PDTM) based on Application-based Thermal Model (ABTM) and Core-based Thermal Model (CBTM) in the multicore systems. Based on predicted temperature from ABTM and CBTM, the proposed PDTM can maintain the system temperature below a desired level by moving the running application from the possi- ble overheated core to the future coolest core (migration) and reducing the processor resources (priority scheduling) within multicore systems. Furthermore, we present the Thermal Correlative Thermal Management (TCDTM), which incorporates three main components: Statistical Workload Estimation (SWE), Future Temperature Estima- tion Model (FTEM) and Temperature-Aware Thread Controller (TATC), to model the thermal correlation eect and distinguish the thermal contributions from appli- cations with dierent workload behaviors at run time in the CMP systems. The pro- posed PDTM and TCDTM enable the exploration of the tradeo between throughput and fairness in temperature-constrained multicore systems.

Liu, Chih-Chun

2008-08-01T23:59:59.000Z

455

TRENDS in Neurosciences Vol.24 No.9 September 2001 http://tins.trends.com  

E-Print Network (OSTI)

-associated virus gene transfer. Gene Ther. 5, 1604­1611 62 Corti, O. et al. (1999) Long-term doxycycline

Schafe, Glenn

456

Department fr Informatik der Fakultt II, Informatik,  

E-Print Network (OSTI)

Kraftwerk wird viel Kohlendioxid produziert; mal davon abgesehen, dass es mit der Kohle irgendwann vorbei

Damm, Werner

457

OCEAN THERMAL ENERGY CONVERSION PROGRAMMATIC ENVIRONMENTAL ASSESSMENT  

E-Print Network (OSTI)

Ocean Thermal Energy Conversion (OTEC) Draft Programmaticof ocean thermal energy conversion technology. U.S. Depart~on Ocean TherUial Energy Conversion, June 18, 1979. Ocean

Sands, M.Dale

2013-01-01T23:59:59.000Z

458

THERMAL PERFORMANCE OF BUILDINGS AND BUILDING ENVELOPE SYSTEMS: AN ANNOTATED BIBLIOGRAPHY  

E-Print Network (OSTI)

in predicting dynamic thermal performance by the admittancea lumped parameter thermal analog model for dynamic ther-5 Presented at the DOE/ASTM Thermal Insulation Conference,

Carroll, William L.

2011-01-01T23:59:59.000Z

459

Swatch Group | Open Energy Information  

Open Energy Info (EERE)

Swatch Group Jump to: navigation, search Name Swatch Group Place Switzerland Product String representation "The Swatch Grou ... ther industries" is too long. References Swatch...

460

Issue 5: High Interest in Hybrid Cars  

E-Print Network (OSTI)

and Associates. (2002). Hybrid Vehicle Consumer Acceptancedefinitely consider a hybrid vehicle, and any of these werepercent or more for a hybrid vehicle. O THER V ARIATIONS IN

Ong, Paul M.; Haselhoff, Kim

2005-01-01T23:59:59.000Z

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


461

Structural analysis of automating measurements of floor gradients  

E-Print Network (OSTI)

It is useful for one owning or buying a house to be able to assess its structure and identify the existence and severity of any damage. No previously existing method appears to make this assessment easily available. This ...

Caplan, Noah S

2011-01-01T23:59:59.000Z

462

Parallel Stochastic Gradient Algorithms for Large-Scale Matrix  

E-Print Network (OSTI)

Apr 26, 2011 ... For example, on the Netflix Prize data set, prior art computes rating predictions in approximately 4 hours, while Jellyfish solves the same...

463

228 Gradient Testing and Thermo-Mechanical Lifetime Modeling of ...  

Science Conference Proceedings (OSTI)

... of LiMnxFe1-xPO4 Glass and Glass-Ceramics for Lithium Ion Battery .... and Comparing the Inhibition Effect of Chromate, Bromate and Molybdate on the...

464

251 Thermal Gradient Cycling with Simultaneous Silicate Particle ...  

Science Conference Proceedings (OSTI)

... of LiMnxFe1-xPO4 Glass and Glass-Ceramics for Lithium Ion Battery .... and Comparing the Inhibition Effect of Chromate, Bromate and Molybdate on the...

465

Ultra-Gradient Test Cavity for Testing SRF Wafer Samples  

SciTech Connect

A 1.3 GHz test cavity has been designed to test wafer samples of superconducting materials. This mushroom shaped cavity, operating in TE01 mode, creates a unique distribution of surface fields. The surface magnetic field on the sample wafer is 3.75 times greater than elsewhere on the Niobium cavity surface. This field design is made possible through dielectrically loading the cavity by locating a hemisphere of ultra-pure sapphire just above the sample wafer. The sapphire pulls the fields away from the walls so the maximum field the Nb surface sees is 25% of the surface field on the sample. In this manner, it should be possible to drive the sample wafer well beyond the BCS limit for Niobium while still maintaining a respectable Q. The sapphire's purity must be tested for its loss tangent and dielectric constant to finalize the design of the mushroom test cavity. A sapphire loaded CEBAF cavity has been constructed and tested. The results on the dielectric constant and loss tangent will be presented

N.J. Pogue, P.M. McIntyre, A.I. Sattarov, C. Reece

2010-11-01T23:59:59.000Z

466

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

467

Gradient Porous Composite Membrane for Fuel Cell Applications  

The heart of current polymer electrolyte fuel cells are the membrane electrode assemblies (MEA), which are composed of (i) an ionomer polymer membrane ...

468

A gradient optimization approach to adaptive multi-robot control  

E-Print Network (OSTI)

This thesis proposes a unified approach for controlling a group of robots to reach a goal configuration in a decentralized fashion. As a motivating example, robots are controlled to spread out over an environment to provide ...

Schwager, Mac

2009-01-01T23:59:59.000Z

469

Effects of Composition and Thermal Gradients on Rapid ...  

Science Conference Proceedings (OSTI)

Differential Characterization of Ikperejere Iron shale and Iron Sandstone Deposit Direct Precipitation of Sr-doped LaP3O9 Thin Film Electrolytes for...

470

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

E-Print Network (OSTI)

An improved Wolfe line search is also proposed, which can ..... Noting that sk = ?k dk, the simple deletion of the last term in (2.3) leads to the conjugate ...... likely to enter some region where the objective function is close to some quadratic...

471

Functionally Graded Material: Carbon Gradient on IF Steel  

Science Conference Proceedings (OSTI)

... Forming Austenitic Stainless Steels for Structural Materials of Nuclear Power ... AND RESIDUAL STRESS FIELDS AND CRITICAL AND ALLOWABLE FLAW...

472

Methods of conjugate gradients for solving linear systems  

Science Conference Proceedings (OSTI)

... the vectors (XI,' . . ,xn ) and (Tcl, ,kn) ' It is assumed that A is nonsingular. Its inverse A - I therefore exists. We denote ...

2013-10-25T23:59:59.000Z

473

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

E-Print Network (OSTI)

Thus, the global convergence is proven by the spectral analysis for non- ...... formed on PC, Intel(R) Core(TM) 2 Duo, E4600 2.40GHz 2.39GHz, RAM. 2.00 GB

474

Decomposition methods based on projected gradient for network ...  

E-Print Network (OSTI)

our convergence analysis. 2 Inexact .... We remark that the convergence analysis of Algorithm IDA can not be derived from ..... machine with 3GByte of RAM.

475

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

E-Print Network (OSTI)

This equivalence does not hold for any quasi-Newton method. .... required. In CG, one only needs to store the most recent previous search direction, pk?1.

476

Enhanced Fatigue Property of a Martensitic Steel with a Gradient ...  

Science Conference Proceedings (OSTI)

Corrosion of Mild Steel in Extreme Oil and Gas Environments Corrosion ... Fluorescent Nanoparticle Tracers for Oil Exploration and Production Formation of...

477

GradientControlled, TypicalDistance Clustering for Global ...  

E-Print Network (OSTI)

the local procedure used, is an implementation of BFGS with a line search and ana ... There is an overhead in the performance of GTC, that is due to the process

478

765kV Transmission line Voltage gradient  

E-Print Network (OSTI)

Corona ring Transmission lines Nowadays, due to the ever increasing energy consumption and power supply optimization, it is required to construct new power plants, substations and transmission lines. In Iran, also, because of increasing demand for electrical energy, for a significant power loss reduction in power transmission over long distances, and to construct high transmission lines that lead to reduction in the economic costs of transmission lines, the transmission lines must be considered at extra high voltage (EHV) levels. These EHV levels should be compared with the low voltage levels in order to extract the benefits. Therefore, in this paper, a review has been conducted on the types of 765 kV transmission lines used in different countries and a comparison between them and the low voltage levels have been performed. Accordingly, the advantages of EHV transmission lines are summarized. Finally, designing a line of 765 kV single-circuit with 6 conductors per bundle based on existing standards is presented.

unknown authors

2012-01-01T23:59:59.000Z

479

On the convergence of the projected gradient method for vector ...  

E-Print Network (OSTI)

Sep 30, 2009... for portfolio selection in security markets vector-valued problems, ...... and assimilative capacity-based ocean disposal decisions, Eur. J. Oper.

480

Paul Tseng . Sangwoon Yun A Coordinate Gradient Descent  

E-Print Network (OSTI)

Sangwoon Y un: D epartment of Mathematics, University of Washington, ...... 1Why43 Fix6587 @9B A587 for some A587 DC domFEG7 and varyH587 .

Note: This page contains sample records for the topic "ther mal gradients" 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.


481

A Robust Gradient Sampling Algorithm for Nonsmooth ... - CECM  

E-Print Network (OSTI)

Oct 20, 2003 ... ?Department of Mathematics, University of Washington, Seattle, WA 98195, U.S.A.. (burke@math.washington.edu). ...... A DC piecewise.

482

A Robust Gradient Sampling Algorithm for Nonsmooth, Nonconvex ...  

E-Print Network (OSTI)

Oct 20, 2003 ... ?Department of Mathematics, University of Washington, Seattle, WA 98195, U.S.A.. (burke@math.washington.edu). ...... A DC piecewise.

483

A Coordinate Gradient Descent Method for Linearly Constrained ...  

E-Print Network (OSTI)

University of Washington ... E-mail: sangwoon@math.washington.edu ..... q ' ( x; J ) is the predicted descent when x is moved along the direction dC' ( x; J ).

484

Thermal Gradient Holes At Cove Fort Area (Warpinski, Et Al.,...  

Open Energy Info (EERE)

not indicated DOE-funding Unknown Notes Update to Warpinski, et al., 2002 References N. R. Warpinski, A. R. Sattler, R. Fortuna, D. A. Sanchez, J. Nathwani (2004) Geothermal...

485

Thermal Gradient Holes At Cove Fort Area - Vapor (Warpinski,...  

Open Energy Info (EERE)

not indicated DOE-funding Unknown Notes Update to Warpinski, et al., 2002 References N. R. Warpinski, A. R. Sattler, R. Fortuna, D. A. Sanchez, J. Nathwani (2004) Geothermal...

486

Distribution of Macroinvertebrates Across a Tidal Gradient, Marin County, California  

E-Print Network (OSTI)

Biological Invasions Grenier J. 2004. Ecology, behavior, andService. 246 p + appendices. Grenier JL, Greenberg R. 2005.Lindsey 3 , and Letitia Grenier 1 ABSTRACT INTRODUCTION The

Robinson, April H.; Cohen, Andrew N.; Lindsey, Brie; Grenier, Letitia

2011-01-01T23:59:59.000Z

487

Representation of Velocity Gradient Effects in a Gaussian Puff Model  

Science Conference Proceedings (OSTI)

The Gaussian puff model framework is extended to provide a description of velocity shear distortion effects. An efficient splitting-merging algorithm is presented so that a maximum puff size can be specified for a calculation. This localizes the ...

R. I. Sykes; D. S. Henn

1995-12-01T23:59:59.000Z

488

Can Gradient Information Be Used to Improve Variational Objective Analysis?  

Science Conference Proceedings (OSTI)

A variational scheme for the analysis of scalar variables is developed and compared to two-pass and three-pass versions of the Barnes analysis scheme. The variational scheme, appropriate for diagnostic studies, is similar to a previously ...

Phillip L. Spencer; Jidong Gao

2004-12-01T23:59:59.000Z

489

A HIGH GRADIENT QUADRUPOLE MAGNET FOR THE SSC  

E-Print Network (OSTI)

Office of High Energy and Nuclear Physics, High EnergyOffice of High Energy and Nuclear Physics, High Energy

Taylor, C.

2010-01-01T23:59:59.000Z

490

Novel geometry gradient coils for MRI designed by genetic algorithm  

E-Print Network (OSTI)

and the irradiating El field from the probe when the latter is used as a transmitter. 12 This is maximal when the field profile of the coil is perpendicular to the main field direction. Hence we want to choose a probe geometry which produces fields perpendicular... to Bo. These probe field are conventionally called El fields. Since we ideally require constant contrast, uniformity is also required across the sample. Probe geometry There are several standard designs of rJ. probes which are used within magnetic...

Williams, Guy Barnett