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1

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...

2

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

3

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"

4

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

5

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...

6

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)...

7

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...

8

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...

9

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...

10

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...

11

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...

12

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...

13

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...

14

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...

15

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...

16

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...

17

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...

18

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...

19

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...

20

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

Note: This page contains sample records for the topic "temperature gradient holes" 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

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

22

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...

23

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...

24

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

25

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

26

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

27

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

28

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

29

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.

30

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

31

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

32

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

33

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

34

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

35

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

36

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

37

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...

38

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...

39

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...

40

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...

Note: This page contains sample records for the topic "temperature gradient holes" 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

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.

42

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

43

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

44

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

45

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

46

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"

47

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

48

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

49

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

50

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

51

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

52

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

53

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

54

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

55

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

56

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"

57

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:

58

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

59

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.

60

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

Note: This page contains sample records for the topic "temperature gradient holes" 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

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

62

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

63

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

64

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

65

Temperatures, heat flow, and water chemistry from drill holes in the Raft  

Open Energy Info (EERE)

Temperatures, heat flow, and water chemistry from drill holes in the Raft Temperatures, heat flow, and water chemistry from drill holes in the Raft River geothermal system, Cassia County, Idaho Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Temperatures, heat flow, and water chemistry from drill holes in the Raft River geothermal system, Cassia County, Idaho Details Activities (1) Areas (1) Regions (0) Abstract: The Raft River area of Idaho contains a geothermal system of intermediate temperatures (approx. = 150 0C) at depths of about 1.5 km. Outside of the geothermal area, temperature measurements in three intermediate-depth drill holes (200 to 400 m) and one deep well (1500 m) indicate that the regional conductive heat flow is about 2.5 mucal/cm 2 sec or slightly higher and that temperature gradients range from 50 0 to 60

66

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

67

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

68

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

69

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

70

Temperatures, heat flow, and water chemistry from drill holes...  

Open Energy Info (EERE)

water chemistry from drill holes in the Raft River geothermal system, Cassia County, Idaho Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Temperatures,...

71

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.

72

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

73

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

74

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

75

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

76

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

77

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

78

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

79

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

80

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 "temperature gradient holes" 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

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

82

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

83

Beowawe geothermal-resource assessment. Final report. Shallow-hole temperature survey geophysics and deep test hole Collins 76-17  

DOE Green Energy (OSTI)

Geothermal resource investigation field efforts in the Beowawe Geysers Area, Eureka County, Nevada are described. The objectives included acquisition of geotechnical data for understanding the nature and extent of the geothermal resource boundaries south of the known resource area. Fourteen shallow (<500 feet) temperature-gradient holes plus geophysics were used to select the site for a deep exploratory well, the Collins 76-17, which was completed to a total depth of 9005 feet. Maximum downhole recorded temperature was 311/sup 0/F, but no flow could be induced.

Jones, N.O.

1983-03-01T23:59:59.000Z

84

Particle-hole symmetry broken pseudogap in high temperature superconductors  

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

Particle-hole symmetry broken pseudogap in Particle-hole symmetry broken pseudogap in high temperature superconductors High-temperature (Tc) superconductivity is one of the most important topics in condensed matter physics. Despite extensive studies over more than two decades, the microscopic mechanism of high temperature superconductivity still remains elusive due to many unconventional properties that are not well understood. Among them, the most mysterious behavior of high-Tc superconductor is the nature of so called "pseudogap", which has been a focus of the field for many years. In conventional superconductors, a gap exists in the energy absorption spectrum only below Tc, corresponding to the energy price to pay for breaking a Cooper pair of electrons. In high-Tc cuprate superconductors, an energy gap called the pseudogap exists above Tc but below T*, and is controversially attributed either to pre-formed superconducting pairs or to competing phases. Recently, by carefully studying the "symmetry" of the gap, researchers Makoto Hashimoto and Rui-Hua He, along with their co-workers in Prof. Zhi-Xun Shen's group at Stanford University, have found crucial evidence suggesting that the particle-hole symmetry required by superconductivity is broken in the pseudogap state.

85

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

86

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

87

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

88

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

89

A Statistical Analysis Of Bottom-Hole Temperature Data In The...  

Open Energy Info (EERE)

Considerable differences in the spread of bottom-hole temperature values from petroleum exploration well logs plotted as a function of depth are observed over a region of...

90

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

91

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.

92

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

93

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

94

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

95

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

96

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

97

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

98

Heat conductance in nonlinear lattices at small temperature gradients  

E-Print Network (OSTI)

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

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

2010-06-09T23:59:59.000Z

99

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

100

A Statistical Analysis Of Bottom-Hole Temperature Data In The Hinton Area  

Open Energy Info (EERE)

A Statistical Analysis Of Bottom-Hole Temperature Data In The Hinton Area A Statistical Analysis Of Bottom-Hole Temperature Data In The Hinton Area Of West-Central Alberta Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Statistical Analysis Of Bottom-Hole Temperature Data In The Hinton Area Of West-Central Alberta Details Activities (0) Areas (0) Regions (0) Abstract: Considerable differences in the spread of bottom-hole temperature values from petroleum exploration well logs plotted as a function of depth are observed over a region of west-central Alberta. The spatial variation of the spread is investigated, and it is found to be greater toward the Rocky Mountain disturbed belt in the west. The spatial variation there does not seem to correspond directly to local topography, and may be partly due

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101

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

102

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

103

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

104

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

105

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

106

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

107

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

108

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

109

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

110

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

111

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

112

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

113

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

DOE Green Energy (OSTI)

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

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

1994-06-01T23:59:59.000Z

114

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

115

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

E-Print Network (OSTI)

Down-hole damages such as borehole collapse, circulation loss and rock tensile/compressive cracking in the open-hole system are well understood at drilling and well completion stages. However, less effort has been made to understand the instability of cemented sections in High Pressure High Temperature (HPHT) wells. The existing analysis shows that, in the perforation zones, casing/cement is subject to instability, particularly in the presence of cavities. This dissertation focuses on the instability mechanism of casing/cement in the non-perforated zones. We investigate the transient thermal behavior in the casing-cement-formation system resulting from the movement of wellbore fluid using finite element method. The critical value of down-hole stresses is identified in both wellbore heating and cooling effects. Differently with the heating effect, the strong cooling effect in a cased hole can produce significant tension inside casing/cement. The confining formation has an obvious influence on the stability of casing/cement. The proposed results reveal that the casing/cement system in the non-homogeneous formation behaves differently from that in homogeneous formation. With this in mind, a three-dimensional layered finite element model is developed to illustrate the casing/cement mechanical behavior in the non-homogeneous formation. The radial stress of cement sheath is found to be highly variable and affected by the contrast in Youngs moduli in the different formation layers. The maximum stress is predicted to concentrate in the casing-cement system confined by the sandstone. Casing wear in the cased-hole system causes significant casing strength reduction, possibly resulting in the casing-cement tangential collapse. In this study, an approach for calculating the stress concentration in the worn casing with considering temperature change is developed, based on boundary superposition. The numerical results indicate that the casing-cement system after casing wear will suffer from severe tangential instability due to the elevated compressive hoop stress. Gas migration during the cementing process results from the fluid cements inability to balance formation pore pressure. Past experience emphasized the application of chemical additives to reduce or control gas migration during the cementing process. This report presents the thermal and mechanical behaviors in a cased hole caused by created gas channels after gas migration. In conclusion, the size and the number of gas channels are two important factors in determining mechanical instability in a casing-cement system.

Shen, Zheng 1983-

2012-12-01T23:59:59.000Z

116

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

117

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

118

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

119

Slim Holes | Open Energy Information  

Open Energy Info (EERE)

Slim Holes Slim Holes Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Slim Holes Details Activities (30) Areas (24) Regions (1) NEPA(6) Exploration Technique Information Exploration Group: Drilling Techniques Exploration Sub Group: Exploration Drilling Parent Exploration Technique: Exploration Drilling Information Provided by Technique Lithology: If core is collected Stratigraphic/Structural: If core is collected Hydrological: Fluid flow and water chemistry Thermal: Thermal gradient or bottom hole temperature Cost Information Low-End Estimate (USD): 100.0010,000 centUSD 0.1 kUSD 1.0e-4 MUSD 1.0e-7 TUSD / foot Median Estimate (USD): 169.8916,989 centUSD 0.17 kUSD 1.6989e-4 MUSD 1.6989e-7 TUSD / foot High-End Estimate (USD): 200.0020,000 centUSD

120

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

Note: This page contains sample records for the topic "temperature gradient holes" 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

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

Science Conference Proceedings (OSTI)

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

Hirofumi Sugawara; Ken-ichi Narita; Takehiko Mikami

2004-08-01T23:59:59.000Z

122

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

Science Conference Proceedings (OSTI)

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

David Rind

1987-11-01T23:59:59.000Z

123

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

E-Print Network (OSTI)

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

Takasaki, Kevin T. (Keven Takao)

2007-01-01T23:59:59.000Z

124

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

Science Conference Proceedings (OSTI)

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

Steven R. Hanna; Ruixin Yang

2001-06-01T23:59:59.000Z

125

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

Science Conference Proceedings (OSTI)

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

2012-12-12T23:59:59.000Z

126

Black hole masking and black hole thermodynamics  

E-Print Network (OSTI)

Masking of black holes means that, for given total mass and Hawking temperatures, these data may correspond to either "pure" black hole or a black hole of a lesser mass surrounded by a massive shell. It is shown that there is one-to one correspondence between this phenomenon and thermodynamics of a black hole in a finite size cavity: masking of black holes is possible if and only if there exists at least one locally unstable black hole solution in the corresponding canonical ensemble.

Zaslavskii, Oleg B

2011-01-01T23:59:59.000Z

127

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

Science Conference Proceedings (OSTI)

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

Robert G. Currie

1981-04-01T23:59:59.000Z

128

On the temperature profile of radiatively efficient geometrically thin disks in black hole binaries with the ASCA GIS  

E-Print Network (OSTI)

X-ray spectra of black hole binaries(BHBs) in the high/soft state were studied comprehensively by using ASCA GIS data, and partially RXTE PCA data. A mathematical disk model was applied to several BHBs to see if the observed accretion disk temperature profile was consistent with that expected from the standard accretion disk model. This model is called p-free disk, and assumes that the spectrum is composed of multi-temperature blackbody emission of which the local temperature T(r) at radius r is given by T(r) ~ r^-p with p being a positive free parameter. The standard disk roughly requires p~3/4, while a small deviation is expected depending on the inner boundary conditions, general relativistic effects and disk vertical structures.Our sample objects included LMC X-1, LMC X-3, XTE J2012+381, and GRO J1655-40. During the ASCA observations, these BHBs showed characteristics of the standard high/soft state. Under the standard modeling of high-state black hole binaries, the sources show Tin=0.76-1.17keV, the disk...

Kubota, A; Makishima, K; Nakazawa, K; Kubota, Aya; Ebisawa, Ken; Makishima, Kazuo; Nakazawa, Kazuhiro

2005-01-01T23:59:59.000Z

129

High-temperature electron-hole transport in PrBaCo{sub 2}O{sub 5+{delta}}  

SciTech Connect

The oxygen content, conductivity and thermopower in the double perovskite-like cobaltite PrBaCo{sub 2}O{sub 5+{delta}} are reported in the oxygen partial pressure range 2x10{sup -6}-0.21 atm and temperatures between 650 and 950 deg. C. The electrical properties are shown to be continuous through the transition from {delta}>0.5 to {delta}<0.5. The variations of transport parameters with temperature and oxygen content reveal hole polaron hopping conduction within oxygen non-stoichiometry domain {delta}<0.5. - Graphical abstract: Electrical properties in PrBaCo{sub 2}O5+{delta} depending on oxygen content at 800 deg. C. Highlights: > The oxygen content in PrBaCo{sub 2}O{sub 5+{delta}} is studied depending on temperature and oxygen partial pressure. > The transport parameter variations reveal hole polaron conduction. > The electrical properties are continuous through the transition from {delta}>0.5 to {delta}<0.5.

Suntsov, A.Yu., E-mail: suntsov@ihim.uran.ru [Institute of Solid State Chemistry, Yekaterinburg 620990 (Russian Federation); Leonidov, I.A.; Patrakeev, M.V.; Kozhevnikov, V.L. [Institute of Solid State Chemistry, Yekaterinburg 620990 (Russian Federation)

2011-08-15T23:59:59.000Z

130

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

131

Signature of Accretion Shocks in Emitted Radiation From a Two Temperature Advective Flows Around Black Holes  

E-Print Network (OSTI)

Centrifugal barrier supported boundary layer (CENBOL) of a black hole affects the spectrum exactly in the same way the boundary layer of a neutron star does. The CENBOL is produced due to standing or oscillating shock waves and these shocks accelerate electrons very efficiently and produce a power-law distribution. The accelerated particles in turn emit synchrotron radiation in presence of the magnetic field. We study the spectral properties of an accretion disk as a function of the shock strength, compression ratio, flow accretion rate and flow geometry. In the absence of a satisfactory description of magnetic fields inside the advective disk, we consider the presence of only stochastic fields and use the ratio of the field energy density to the gravitational energy density to be a parameter. Not surprisingly, stronger fields produce stronger humps due to synchrotron radiation. We not only include `conventional' synchrotron emission and Comptonization due to Maxwell-Bolzmann electrons in the gas, we also com...

Mandal, S; Mandal, Samir; Chakrabarti, Sandip K.

2005-01-01T23:59:59.000Z

132

On the temperature profile of radiatively efficient geometrically thin disks in black hole binaries with the ASCA GIS  

E-Print Network (OSTI)

X-ray spectra of black hole binaries(BHBs) in the high/soft state were studied comprehensively by using ASCA GIS data, and partially RXTE PCA data. A mathematical disk model was applied to several BHBs to see if the observed accretion disk temperature profile was consistent with that expected from the standard accretion disk model. This model is called p-free disk, and assumes that the spectrum is composed of multi-temperature blackbody emission of which the local temperature T(r) at radius r is given by T(r) ~ r^-p with p being a positive free parameter. The standard disk roughly requires p~3/4, while a small deviation is expected depending on the inner boundary conditions, general relativistic effects and disk vertical structures.Our sample objects included LMC X-1, LMC X-3, XTE J2012+381, and GRO J1655-40. During the ASCA observations, these BHBs showed characteristics of the standard high/soft state. Under the standard modeling of high-state black hole binaries, the sources show Tin=0.76-1.17keV, the disk fraction to the total 0.7-10keV flux of 54-98%, and Nh=(0.7--12)E21/cm^2. The best-fit p-values were found in 0.6-0.8, and the standard value of p=3/4 was accepted for all the sources.The obtained p-values are also compared with those expected for the standard accretion disk in the Schwarzschild metric, and they were consistent with those expected from the standard accretion disk.

Aya Kubota; Ken Ebisawa; Kazuo Makishima; Kazuhiro Nakazawa

2005-05-17T23:59:59.000Z

133

Monitoring temperature conditions in recently drilled nonproductive industry boreholes in Oklahoma  

SciTech Connect

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

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

1985-06-01T23:59:59.000Z

134

Development of a High Pressure/High Temperature Down-hole Turbine Generator  

SciTech Connect

As oil & natural gas deposits become more difficult to obtain by conventional means, wells must extend to deeper more heat-intensive environments. The technology of the drilling equipment required to reach these depths has exceeded the availability of electrical power sources needed to operate these tools. Historically, logging while drilling (LWD) and measure while drilling (MWD) devices utilized a wireline to supply power and communication from the operator to the tool. Lithium ion batteries were used in scenarios where a wireline was not an option, as it complicated operations. In current downhole applications, lithium ion battery (LIB) packs are the primary source for electrical power. LIB technology has been proven to supply reliable downhole power at temperatures up to 175 C. Many of the deeper well s reach ambient temperatures above 200 C, creating an environment too harsh for current LIB technology. Other downfalls of LIB technology are cost, limitations on charge cycles, disposal issues and possible safety hazards including explosions and fires. Downhole power generation can also be achieved by utilizing drilling fluid flow and converting it to rotational motion. This rotational motion can be harnessed to spin magnets around a series of windings to produce power proportional to the rpm experienced by the driven assembly. These generators are, in most instances, driven by turbine blades or moyno-based drilling fluid pumps. To date, no commercially available downhole power generators are capable of operating at ambient temperatures of 250 C. A downhole power g enerator capable of operation in a 250 C and 20,000 psi ambient environment will be an absolute necessity in the future. Dexter Magnetic Technologies High-Pressure High-Temperature (HPHT) Downhole Turbine Generator is capable of operating at 250 C and 20, 000 psi, but has not been tested in an actual drilling application. The technology exists, but to date no company has been willing to test the tool.

Ben Plamp

2008-06-30T23:59:59.000Z

135

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

136

Slim Holes At Blue Mountain Area (Fairbank Engineering, 2009) | Open Energy  

Open Energy Info (EERE)

Fairbank Engineering, 2009) Fairbank Engineering, 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Blue Mountain Area (Fairbank Engineering, 2009) Exploration Activity Details Location Blue Mountain Area Exploration Technique Slim Holes Activity Date Usefulness useful DOE-funding Unknown Notes DEEP BLUE No.1, the first slim geothermal observation test hole at Blue Mountain, was drilled under a cost-share program between the DOE and Noramex, under the DOE's Geothermal Resource Exploration and Definition (GRED) program, (Noramex Corp., 2002). The hole was sited to test an area of projected high temperature at depth from gradients measured in shallow holes drilled in the central part of the lease area (Figure 3.1), and to test an area of low apparent resistivity interpreted to reflect possible

137

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

Science Conference Proceedings (OSTI)

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

I. T. Wang

1981-10-01T23:59:59.000Z

138

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

Science Conference Proceedings (OSTI)

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

Clara Deser; Susan Wahl; John J. Bates

1993-06-01T23:59:59.000Z

139

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

140

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

Note: This page contains sample records for the topic "temperature gradient holes" 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

Linear electron-hole-electron pair model of high-temperature superconductivity in La sub 2-x M sub x CuO sub 4 and YBa sub 2 Cu sub 3 O sub 7-y : 2, Dependence of the superconducting transition temperatures on pressure and on hole concentration  

Science Conference Proceedings (OSTI)

On the basis of the linear electron-hole-electron (e-h-e) pair model, we discuss how the number of holes (i.e., formal Cu{sup 3+} sites), and an applied pressure, affect the superconducting transition temperatures {Tc} of La{sub 2-x}M{sub x}CuO{sub 4} and LBa{sub 2}Cu{sub 3}O{sub 7-y}(L = Y, Sm, Eu, Gd, Dy, Ho, Yb). We also examine the origin of the plateaus in the {Tc} vs oxygen content pilot of YBa{sub 2}Cu{sub 3}O{sub 7-y} within the framework of the linear e-h-e pair model. 17 refs.

Whangbo, Myung-Hwan; Evain, M.; Canadell, E.; Williams, J.M. (North Carolina State Univ., Raleigh, NC (USA). Dept. of Chemistry; Paris-11 Univ., 91 - Orsay (France). Lab. de Chimie Theorique; Argonne National Lab., IL (USA))

1989-01-01T23:59:59.000Z

142

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

143

Mt. Hood geothermal exploratory drilling and testing plan. Old Maid Flat holes No. 1 and No. 7A  

DOE Green Energy (OSTI)

This plan has been prepared to establish the objectives and set forth the procedures and guidelines for conducting geothermal exploratory drilling and testing operations in the Old Maid Flat area of Mt. Hood, Oregon, approximately 50 miles east of Portland. The project will be conducted on lands within the Mt. Hood National Forest, which are currently under Federal Lease OR 13994 to the Northwest Geothermal Corporation. The exploratory geothermal operations will consist of (1) testing an existing 4,000-foot temperature gradient hole to determine the quality of geothermal fluids, and (2) drilling and testing a new 5,000-foot hole to determine overall geothermal reservoir characteristics.

Not Available

1980-05-01T23:59:59.000Z

144

Electromagnetically induced transparency over spectral hole-burning  

E-Print Network (OSTI)

Electromagnetically induced transparency over spectral hole-burning temperature in a rare the spectral hole-burning temperature. The transmission of the probe laser beam is increased by a factor of exp over the spectral hole-burning temperature in a rare-earth­doped solid represents important progress

Shahriar, Selim

145

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

146

San Emidio Desert Prospect, Washoe and Pershing Counties, Nevada, for Chevron Oil Co., Wells Se-A and SE-B, Temperature depth data, 19 wells  

DOE Green Energy (OSTI)

During 1977 Chevron Resources conducted numerous temperature hole programs in the San Emidio Desert Prospect, Nevada. These programs were projected to evaluate recently acquired Fee Land and acreage which could be included in a unit package. The 1977 temperature holes (Map 1) were drilled to a maximum depth of 500 feet with a minimum of 100 feet. Maximum temperature encountered in these holes was 232 F with an average gradient of {approx} 9 F/100 feet (300-400 feet) and {approx} 11 F/100 feet (100-200 feet). In addition, shot holes drilled during the seismic program had temperature pipe installed and were also logged. Table 1 reflects data pertinent to the temperature holes drilled in 1977; in addition, complete temperature gradient plots (Appendix A) and lithology descriptions (Appendix B) are included in this report. Water samples from two temperature holes were collected early in the 1977 program and analyzed by Skyline Laboratories (Appendix C). The results of the estimated base temperature calculations are given.

Kehoe, Mark

1977-01-01T23:59:59.000Z

147

Of the Black Hole Thermodynamics  

E-Print Network (OSTI)

About thirty years ago, Bekenstein and Hawking introduced three basic concepts relating to black hole, namely, the "area entropy", "gravitation temperature" and "thermal radiation". The author analyzes these concepts systematically and concludes that they are mostly inadequate or wrong. He points out that a black hole's taking in thermal radiation from the space is an energy-gathering process. It is special, even extraordinary. It reduces entropy, violating Clausius' second law.

Xinyong Fu

2005-01-11T23:59:59.000Z

148

Interpretation of well log data from four drill holes at Roosevelt Hot Springs KGRA  

DOE Green Energy (OSTI)

Well logs from four drill holes, Utah State Geothermal Wells 14-2, 52-21 and 72-16 and Geothermal Power Corporation's thermal gradient hole GPC-15 have been digitized, plotted and studied. This study had three objectives: (1) to present the well log data in a convenient format for easy study, (2) to determine the nature of the geothermal reservoir rock and fluid properties, and (3) to make some inference on fluid entry locations in the boreholes and their effect on heat flow. The temperature logs and gradients computed from these logs have been used to examine heat flow in the vicinity of the four drill holes. Assumed and calculated thermal conductivities have been used in the analyses, 4 mcal/cm /sup 0/C sec for the alluvium and 7 mcal/cm /sup 0/C sec for the crystalline rocks. The data indicate that 14-2 and 72-16 reside in a dominantly convective heat flow environment, whereas GPC-15 and 52-21 reside in a dominantly conductive heat flow environment. The convective regions are believed to be fracture controlled and only portions of each hole reside totally in a convective region; in each case it is the upper bedrock portion of the hole. In every case the alluvium or upper portion of the alluvium acts as a thermal blanket over the system. Maximum heat flow among the holes, 40 ..mu.. cal/cm/sup 2/ sec, occurs in the vicinity of 72-16 and the lowest heat flow, 4 ..mu.. cal/cm/sup 2/ sec, in the vicinity of GPC-15. (MHR)

Glenn, W.E.; Hulen, J.B.

1979-12-01T23:59:59.000Z

149

Quantum Criticality and Black Holes  

SciTech Connect

I will describe the behavior of a variety of condensed matter systems in the vicinity of zero temperature quantum phase transitions. There is a remarkable analogy between the hydrodynamics of such systems and the quantum theory of black holes. I will show how insights from this analogy have shed light on recent experiments on the cuprate high temperature superconductors. Studies of new materials and trapped ultracold atoms are yielding new quantum phases, with novel forms of quantum entanglement. Some materials are of technological importance: e.g. high temperature superconductors. Exact solutions via black hole mapping have yielded first exact results for transport coefficients in interacting many-body systems, and were valuable in determining general structure of hydrodynamics. Theory of VBS order and Nernst effect in cuprates. Tabletop 'laboratories for the entire universe': quantum mechanics of black holes, quark-gluon plasma, neutrons stars, and big-bang physics.

Sachdev, Subir (Harvard)

2007-08-22T23:59:59.000Z

150

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

151

Thermodynamics of Schwarzschild-de Sitter black hole: thermal stability of Nariai black hole  

E-Print Network (OSTI)

We study thermodynamics of the Schwarzschild-de Sitter black hole in five dimensions by introducing two temperatures based on the standard and Bousso-Hawking normalizations. We use the first-law of thermodynamics to derive thermodynamic quantities. The two temperatures indicate that the Nariai black hole is thermodynamically unstable. However, it seems that black hole thermodynamics favors the standard normalization, and does not favor the Bousso-Hawking normalization.

Yun Soo Myung

2007-12-20T23:59:59.000Z

152

Thermodynamics of Schwarzschild-de Sitter black hole: thermal stability of Nariai black hole  

E-Print Network (OSTI)

We study thermodynamics of the Schwarzschild-de Sitter black hole in five dimensions by introducing two temperatures based on the standard and Bousso-Hawking normalization. We use the first-law of thermodynamics to derive thermodynamic quantities. The two temperatures indicate that the Nariai black hole is thermodynamically unstable. However, it seems that black hole thermodynamics favors the standard normalization and disfavors the Bousso-Hawking normalization.

Myung, Yun Soo

2007-01-01T23:59:59.000Z

153

Effects of the Distributions of Energy or Charge Transfer Rates on Spectral Hole Burning in Pigment-Protein Complexes at Low Temperatures  

Science Conference Proceedings (OSTI)

Effects of the distributions of excitation energy transfer (EET) rates (homogeneous line widths) on the nonphotochemical (resonant) spectral hole burning (SHB) processes in photosynthetic chlorophyll-protein complexes (reaction center [RC] and CP43 antenna of Photosystem II from spinach) are considered. It is demonstrated that inclusion of such a distribution results in somewhat more dispersive hole burning kinetics. More importantly, however, inclusion of the EET rate distributions strongly affects the dependence of the hole width on the fractional hole depth. Different types of line width distributions have been explored, including those resulting from Foerster type EET between weakly interacting pigments as well as Gaussian ones, which may be a reasonable approximation for those resulting, for instance, from so-called extended Foerster models. For Gaussian line width distributions, it is possible to determine the parameters of both line width and tunneling parameter distributions from SHB data without a priori knowledge of any of them. Concerning more realistic asymmetric distributions, we demonstrate, using the simple example of CP43 antenna, that one can use SHB modeling to estimate electrostatic couplings between pigments and support or exclude assignment of certain pigment(s) to a particular state.

Herascu, N.; Ahmouda, S.; Picorel, R.; Seibert, M.; Jankowiak, R.; Zazubovich, V.

2011-12-22T23:59:59.000Z

154

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

Science Conference Proceedings (OSTI)

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

Masahiro Sugiyama

2009-06-01T23:59:59.000Z

155

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

156

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

157

Black holes 1. Introduction  

E-Print Network (OSTI)

Black holes 1. Introduction What is a black hole? Roughly it can be described as a region that nothing can escape from it. Light falling into a black hole cannot escape from it. It is called `black' because it does not reflect anything. Since nothing can escape from it, it means that a black hole

Glass, Ian S.

158

Nonstationary artificial black holes  

E-Print Network (OSTI)

We study the existence of artificial non-stationary spherically symmetric black holes. We give examples of the appearance of black holes and of disappearance of white holes. We also discuss the relation between the apparent and the event horizons for the case of artificial black holes.

Eskin, Gregory

2013-01-01T23:59:59.000Z

159

Black Hole Thermodynamics and Electromagnetism  

E-Print Network (OSTI)

We show a strong parallel between the Hawking, Beckenstein black hole Thermodynamics and electromagnetism: When the gravitational coupling constant transform into the electromagnetic coupling constant, the Schwarzchild radius, the Beckenstein temperature, the Beckenstein decay time and the Planck mass transform to respectively the Compton wavelength, the Hagedorn temperature, the Compton time and a typical elementary particle mass. The reasons underlying this parallalism are then discussed in detail.

Burra G. Sidharth

2005-07-15T23:59:59.000Z

160

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...

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


161

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...

162

Thermal Gradient Holes At Northern Basin & Range Region (Pritchett...  

Open Energy Info (EERE)

Date Usefulness not useful DOE-funding Unknown Notes NOTE: These are theoreticalcomputer simulation tests of various methods on eight hypothetical 'model' basing-and-range...

163

Black Hole Horizons and Black Hole Thermodynamics.  

E-Print Network (OSTI)

??This work investigates how black holes can be described in terms of different definitions of horizons. Global definitions in terms of event horizons and Killing (more)

Nielsen, Alex

2007-01-01T23:59:59.000Z

164

Thermodynamics of Dyonic Lifshitz Black Holes  

E-Print Network (OSTI)

Black holes with asymptotic anisotropic scaling are conjectured to be gravity duals of condensed matter system close to quantum critical points with non-trivial dynamical exponent z at finite temperature. A holographic renormalization procedure is presented that allows thermodynamic potentials to be defined for objects with both electric and magnetic charge in such a way that standard thermodynamic relations hold. Black holes in asymptotic Lifshitz spacetimes can exhibit paramagnetic behavior at low temperature limit for certain values of the critical exponent z, whereas the behavior of AdS black holes is always diamagnetic.

Tobias Zingg

2011-07-15T23:59:59.000Z

165

FORCE-FEEDING BLACK HOLES  

SciTech Connect

We propose that the growth of supermassive black holes is associated mainly with brief episodes of highly super-Eddington infall of gas ({sup h}yperaccretion{sup )}. This gas is not swallowed in real time, but forms an envelope of matter around the black hole that can be swallowed gradually, over a much longer timescale. However, only a small fraction of the black hole mass can be stored in the envelope at any one time. We argue that any infalling matter above a few percent of the hole's mass is ejected as a result of the plunge in opacity at temperatures below a few thousand degrees kelvin, corresponding to the Hayashi track. The speed of ejection of this matter, compared to the velocity dispersion {sigma} of the host galaxy's core, determines whether the ejected matter is lost forever or returns eventually to rejoin the envelope, from which it can be ultimately accreted. The threshold between matter recycling and permanent loss defines a relationship between the maximum black hole mass and {sigma} that resembles the empirical M{sub BH}-{sigma} relation.

Begelman, Mitchell C., E-mail: mitch@jila.colorado.edu [Also at Department of Astrophysical and Planetary Sciences, University of Colorado Boulder, CO, USA. (United States)

2012-04-10T23:59:59.000Z

166

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

DOE Green Energy (OSTI)

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

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

1982-01-01T23:59:59.000Z

167

Quantum Harmonic Black Holes  

E-Print Network (OSTI)

Inspired by the recent conjecture that black holes are condensates (of gravitons), we investigate a simple model for the black hole degrees of freedom that is consistent both from the point of view of Quantum mechanics and of General Relativity. Since the two perspectives should converge for small, Planck size, black holes, we expect our construction is useful for understanding the physics of microscopic, quantum black holes.

Casadio, R

2013-01-01T23:59:59.000Z

168

Black holes without firewalls  

E-Print Network (OSTI)

The postulates of black hole complementarity do not imply a firewall for infalling observers at a black hole horizon. The dynamics of the stretched horizon, that scrambles and re-emits information, determines whether infalling observers experience anything out of the ordinary when entering a large black hole. In particular, there is no firewall if the stretched horizon degrees of freedom retain information for a time of order the black hole scrambling time.

Larjo, Klaus; Thorlacius, Larus

2013-01-01T23:59:59.000Z

169

Phantom Black Holes  

E-Print Network (OSTI)

The exact solutions of electrically charged phantom black holes with the cosmological constant are constructed. They are labelled by the mass, the electrical charge, the cosmological constant and the coupling constant between the phantom and the Maxwell field. It is found that the phantom has important consequences on the properties of black holes. In particular, the extremal charged phantom black holes can never be achieved and so the third law of thermodynamics for black holes still holds. The cosmological aspects of the phantom black hole and phantom field are also briefly discussed.

C. J. Gao; S. N. Zhang

2006-04-17T23:59:59.000Z

170

RHIC | Black Holes?  

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

Black Holes at RHIC? Black Holes at RHIC? Further discussion by Physicist Dmitri Kharzeev on why RHIC cannot produce a real gravitational black hole Black holes are among the most mysterious objects in the universe. The gravitational field of a black hole is so strong that Einstein's general relativity tells us that nothing, not even light, can escape from the black hole's interior. However, in 1974 physicist Stephen Hawking demonstrated that black holes must emit radiation once the quantum effects are included. According to quantum mechanics, the physical vacuum is bubbling with short-lived virtual particle-antiparticle pairs. Creation of a particle-antiparticle pair from the vacuum conflicts with energy conservation, but energy need not be conserved at short times in quantum mechanics, according to Heisenberg's

171

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

172

Cold black holes and conformal continuations  

E-Print Network (OSTI)

We study Einstein gravity minimally coupled to a scalar field in a static, spherically symmetric space-time in four dimensions. Black hole solutions are shown to exist for a phantom scalar field whose kinetic energy is negative. These ``scalar black holes'' have an infinite horizon area and zero Hawking temperature and are termed ``cold black holes'' (CBHs). The relevant explicit solutions are well-known in the massless case (the so-called anti-Fisher solution), and we have found a particular example of a CBH with a nonzero potential $V(\\phi)$. All CBHs with $V(\\phi) \

K. A. Bronnikov; M. S. Chernakova; J. C. Fabris; N. Pinto-Neto; M. E. Rodrigues

2006-09-20T23:59:59.000Z

173

Radion clouds around evaporating black holes  

E-Print Network (OSTI)

A Kaluza-Klein model, with a matter source associated with Hawking radiation from an evaporating black hole, is used to obtain a simple form for the radion effective potential. The environmental effect generally causes a matter-induced shift of the radion vacuum, resulting in the formation of a radion cloud around the hole. There is an albedo due to the radion cloud, with an energy dependent reflection coefficient that depends upon the size of the extra dimensions and the temperature of the hole.

J. R. Morris

2009-09-03T23:59:59.000Z

174

Higher Spin Black Holes from CFT  

E-Print Network (OSTI)

Higher spin gravity in three dimensions has explicit black holes solutions, carrying higher spin charge. We compute the free energy of a charged black hole from the holographic dual, a 2d CFT with extended conformal symmetry, and find exact agreement with the bulk thermodynamics. In the CFT, higher spin corrections to the free energy can be calculated at high temperature from correlation functions of W-algebra currents.

Gaberdiel, Matthias R; Jin, Kewang

2012-01-01T23:59:59.000Z

175

Higher Spin Black Holes from CFT  

E-Print Network (OSTI)

Higher spin gravity in three dimensions has explicit black holes solutions, carrying higher spin charge. We compute the free energy of a charged black hole from the holographic dual, a 2d CFT with extended conformal symmetry, and find exact agreement with the bulk thermodynamics. In the CFT, higher spin corrections to the free energy can be calculated at high temperature from correlation functions of W-algebra currents.

Matthias R. Gaberdiel; Thomas Hartman; Kewang Jin

2012-02-29T23:59:59.000Z

176

Static Temperature Survey At Vale Hot Springs Area (Combs, Et Al., 1999) |  

Open Energy Info (EERE)

Vale Hot Springs Area (Combs, Et Al., 1999) Vale Hot Springs Area (Combs, Et Al., 1999) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Static Temperature Survey At Vale Hot Springs Area (Combs, Et Al., 1999) Exploration Activity Details Location Vale Hot Springs Area Exploration Technique Static Temperature Survey Activity Date Usefulness not indicated DOE-funding Unknown Notes Numerous temperature logs were taken with Sandia's platinum-resistance-thermometer (PRT) tool which along with a Sandia logging truck remained on-site for the entire project. Static temperature logs (no flow in hole) were done with this tool when coring operations were suspended for bit trips, rig maintenance, or other time intervals that would permit the hole to warm up near its static temperature gradient.

177

Pressure Temperature Log At Vale Hot Springs Area (Combs, Et Al., 1999) |  

Open Energy Info (EERE)

Vale Hot Springs Area (Combs, Et Al., 1999) Vale Hot Springs Area (Combs, Et Al., 1999) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Pressure Temperature Log At Vale Hot Springs Area (Combs, Et Al., 1999) Exploration Activity Details Location Vale Hot Springs Area Exploration Technique Pressure Temperature Log Activity Date Usefulness not indicated DOE-funding Unknown Notes Numerous temperature logs were taken with Sandia's platinum-resistance-thermometer (PRT) tool which along with a Sandia logging truck remained on-site for the entire project. Static temperature logs (no flow in hole) were done with this tool when coring operations were suspended for bit trips, rig maintenance, or other time intervals that would permit the hole to warm up near its static temperature K580gradient.

178

A Black Hole Levitron  

E-Print Network (OSTI)

We study the problem of spatially stabilising four dimensional extremal black holes in background electric/magnetic fields. Whilst looking for stationary stable solutions describing black holes kept in external fields we find that taking a continuum limit of Denef et al's multi-center solutions provides a supergravity description of such backgrounds within which a black hole can be trapped in a given volume. This is realised by levitating a black hole over a magnetic dipole base. We comment on how such a construction resembles a mechanical Levitron.

Xerxes D. Arsiwalla; Erik P. Verlinde

2009-02-02T23:59:59.000Z

179

Charged fermions tunneling from regular black holes  

SciTech Connect

We study Hawking radiation of charged fermions as a tunneling process from charged regular black holes, i.e., the Bardeen and ABGB black holes. For this purpose, we apply the semiclassical WKB approximation to the general covariant Dirac equation for charged particles and evaluate the tunneling probabilities. We recover the Hawking temperature corresponding to these charged regular black holes. Further, we consider the back-reaction effects of the emitted spin particles from black holes and calculate their corresponding quantum corrections to the radiation spectrum. We find that this radiation spectrum is not purely thermal due to the energy and charge conservation but has some corrections. In the absence of charge, e = 0, our results are consistent with those already present in the literature.

Sharif, M., E-mail: msharif.math@pu.edu.pk; Javed, W., E-mail: wajihajaved84@yahoo.com [University of the Punjab, Department of Mathematics (Pakistan)

2012-11-15T23:59:59.000Z

180

Rotating Hairy Black Holes  

E-Print Network (OSTI)

We construct stationary black holes in SU(2) Einstein-Yang-Mills theory, which carry angular momentum and electric charge. Possessing non-trivial non-abelian magnetic fields outside their regular event horizon, they represent non-perturbative rotating hairy black holes.

B. Kleihaus; J. Kunz

2000-12-20T23:59:59.000Z

Note: This page contains sample records for the topic "temperature gradient holes" 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

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

Open Energy Info (EERE)

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

182

Black Hole Mergers Manuela Campanelli  

E-Print Network (OSTI)

Black Hole Mergers Manuela Campanelli Center for Computa6 Department of Physics Duke University Feb 15-17, 2012 #12;Black Holes Antennae galaxies, op6cal, HST · In General Rela6vity (GR), Black Holes (BHs

Wolpert, Robert L

183

Stationary Black Holes Robert Beig*  

E-Print Network (OSTI)

Stationary Black Holes Robert Beig Abstract We review the theory of stationary black hole solutions of vacuum Einstein equations. Keywords: black holes, event horizons, Schwarzschild metric, Kerr metric, no-hair theorems 1

Chru?ciel, Piotr T.

184

Is spacetime hole-free?  

E-Print Network (OSTI)

which fails to be hole-free. We show that it is extendible.ARTICLE Is spacetime hole-free? John Byron Manchak Received:which fail to be hole-free. We then propose an updated

Manchak, John Byron

2009-01-01T23:59:59.000Z

185

String-corrected dilatonic black holes in d dimensions  

Science Conference Proceedings (OSTI)

We solve the dilaton field equation in the background of a spherically symmetric black hole in bosonic or heterotic string theory with curvature-squared corrections in arbitrary d spacetime dimensions. We then apply this result to obtain a spherically symmetric black hole solution with dilatonic charge and curvature-squared corrections in bosonic or heterotic string theory compactified on a torus. For this black hole, we obtain its free energy, entropy, temperature, specific heat, and mass.

Moura, Filipe [Centro de Matematica da Universidade do Minho, Escola de Ciencias, Campus de Gualtar, 4710-057 Braga (Portugal)

2011-02-15T23:59:59.000Z

186

Lifshits quantum phase transitions and rearrangement of the Fermi surface upon a change in the hole concentration in high-temperature superconductors  

SciTech Connect

Changes in the electronic structure in the normal phase of high-T{sub c} superconductors (HTSCs), viz., layered cuprates, are considered. The results of LDA + GTB calculations of the electron structure and the Fermi surface of La{sub 2-x}Sr{sub x}CuO{sub 4} one-layer cuprates with allowance for strong correlations are compared with ARPES and quantum oscillations data. Two critical points x{sub c1} and x{sub c2} are discovered at which the rear-rangement of the Fermi surface takes place. In the vicinity of these points, changes in the thermodynamic properties at low temperatures are determined using the Lifshits ideology concerning 2.5-order quantum phase transitions. A singularity {delta}(C/T) {proportional_to} (x - x{sub e}){sup 1/2} in the electron heat capacity agrees well with the available experimental data in the vicinity of x{sub c1} {approx} 0.15. Sign reversal of the Hall constant upon doping is also considered qualitatively.

Ovchinnikov, S. G., E-mail: sgo@iph.krasn.ru; Korshunov, M. M.; Shneyder, E. I. [Russian Academy of Sciences, Kirenskii Institute of Physics, Siberian Branch (Russian Federation)

2009-11-15T23:59:59.000Z

187

Black Hole Shadows of Charged Spinning Black Holes  

E-Print Network (OSTI)

We propose a method for measuring the black hole charge by imaging a black hole shadow in a galactic center by future interferometers. Even when the black hole is uncharged, it is possible to confirm the charge neutrality by this method. We first derive the analytic formulae of the black hole shadow in an optically thin medium around a charged spinning black hole, and then investigate how contours of the black hole shadow depend on the spin and the charge of the black hole for several inclination angles between the rotation axis of the black hole and the observer. This method only assumes stationary black hole and general relativity. By fitting the formula of the contours of the shadow to the observed image of the shadow, in addition to the black hole charge, one can also determine the black hole spin and the inclination angle without any degeneracy among the charge, the spin, and the inclination angle unless the inclination angle is null.

Rohta Takahashi

2005-05-16T23:59:59.000Z

188

Moduli Vacuum Bubbles Produced by Evaporating Black Holes  

E-Print Network (OSTI)

We consider a model with a toroidally compactified extra dimension giving rise to a temperature-dependent 4d effective potential with one-loop contributions due to the Casimir effect, along with a 5d cosmological constant. The forms of the effective potential at low and high temperatures indicates a possibility for the formation of a domain wall bubble, formed by the modulus scalar field, surrounding an evaporating black hole. This is viewed as an example of a recently proposed black hole vacuum bubble arising from matter-sourced moduli fields in the vicinity of an evaporating black hole [D. Green, E. Silverstein, and D. Starr, Phys. Rev. D74, 024004 (2006), arXiv:hep-th/0605047]. The black hole bubble can be highly opaque to lower energy particles and photons, and thereby entrap them within. For high temperature black holes, there may also be a symmetry-breaking black hole bubble of false vacuum of the type previously conjectured by Moss [I.G. Moss, Phys. Rev. D32,1333 (1985)], tending to reflect low energy particles from its wall. A double bubble composed of these two different types of bubble may form around the black hole, altering the hole's emission spectrum that reaches outside observers. Smaller mass black holes that have already evaporated away could have left vacuum bubbles behind that contribute to the dark matter.

J. R. Morris

2007-08-14T23:59:59.000Z

189

Gravitational fields with sources, regular black holes, quasiblack holes, and analogue black holes  

E-Print Network (OSTI)

We discuss recent developments in gravitational fields with sources, regular black holes, quasiblack holes, and analogue black holes, related to the talks presented at the corresponding Parallel Session AT3 of the 13th Marcel Grossmann Meeting.

Lemos, Jos P S

2013-01-01T23:59:59.000Z

190

Black holes at accelerators.  

E-Print Network (OSTI)

collision of high-energy particles, Phys. Rev. D 67, 024009 (2003) [arXiv:gr-qc/0209003]. [6] D. M. Eardley and S. B. Giddings, Classical black hole production in high-energy collisions, Phys. Rev. D 66, 044011 (2002) [arXiv:gr-qc/0201034]. [7] H. Yoshino... about black hole formation in high-energy collisions, Class. Quant. Grav. 22, L61 (2005) [arXiv:hep-ph/0505125]. [16] G. T. Horowitz, Higher dimensional generalizations of the Kerr black hole, arXiv:gr-qc/0507080. [17] C. M. Harris and P. Kanti...

Webber, Bryan R

191

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

192

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

193

RHIC | Black Holes?  

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

Black Holes at RHIC? Black Holes at RHIC? Before RHIC began operations in 2000, some were concerned that it would produce black holes that would threaten the earth. Here's why those concerns were unfounded. Committee Review of Speculative "Disaster Scenarios" at RHIC In July 1999, Brookhaven Lab Director John Marburger convened a committee of distinguished physicists to write a comprehensive report on the arguments that address the safety of speculative disaster scenarios at RHIC. The scenarios are: Creation of a black hole that would "eat" ordinary matter. Initiation of a transition to a new, more stable universe. Formation of a "strangelet" that would convert ordinary matter to a new form. jaffee "We conclude that there are no credible mechanisms for catastrophic

194

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

195

Black holes and beyond  

SciTech Connect

The black hole information paradox forces us into a strange situation: we must find a way to break the semiclassical approximation in a domain where no quantum gravity effects would normally be expected. Traditional quantizations of gravity do not exhibit any such breakdown, and this forces us into a difficult corner: either we must give up quantum mechanics or we must accept the existence of troublesome 'remnants'. In string theory, however, the fundamental quanta are extended objects, and it turns out that the bound states of such objects acquire a size that grows with the number of quanta in the bound state. The interior of the black hole gets completely altered to a 'fuzzball' structure, and information is able to escape in radiation from the hole. The semiclassical approximation can break at macroscopic scales due to the large entropy of the hole: the measure in the path integral competes with the classical action, instead of giving a subleading correction. Putting this picture of black hole microstates together with ideas about entangled states leads to a natural set of conjectures on many long-standing questions in gravity: the significance of Rindler and de Sitter entropies, the notion of black hole complementarity, and the fate of an observer falling into a black hole. - Highlights: Black-Right-Pointing-Pointer The information paradox is a serious problem. Black-Right-Pointing-Pointer To solve it we need to find 'hair' on black holes. Black-Right-Pointing-Pointer In string theory we find 'hair' by the fuzzball construction. Black-Right-Pointing-Pointer Fuzzballs help to resolve many other issues in gravity.

Mathur, Samir D., E-mail: mathur.16@osu.edu

2012-11-15T23:59:59.000Z

196

Stationary Black Holes Robert Beig #  

E-Print Network (OSTI)

Stationary Black Holes Robert Beig # Piotr T. Chru?sciel + February 8, 2005 Abstract We review the theory of stationary black hole solutions of vacuum Einstein equations. Keywords: black holes, event. this space­time a natural model for a non­rotating black hole. We can now come back to the problem

Chru?ciel, Piotr T.

197

Physics of AGN Black Holes  

E-Print Network (OSTI)

Physics of AGN Black Holes Heino Falcke MPIfR Bonn Contents: ffl Why Black Holes? ffl What are black holes? ffl Luminosity ffl Observational Evidence Literature: ``An Introduction to Active Galactic. #12; Black Hole Paradigm Not really hollow For typical quasar luminosity of L = 10 46 L 46 erg sec

Falcke, Heino

198

Stationary Black Holes Robert Beig  

E-Print Network (OSTI)

Stationary Black Holes Robert Beig Piotr T. Chru´sciel February 8, 2005 Abstract We review the theory of stationary black hole solutions of vacuum Einstein equations. Keywords: black holes, event-Szekeres extension of the Schwarzschild solution. this space-time a natural model for a non-rotating black hole. We

Chru?ciel, Piotr T.

199

Acoustic analogs of two-dimensional black holes  

E-Print Network (OSTI)

We present a general method for constructing acoustic analogs of the black hole solutions of two-dimensional (2D) dilaton gravity. Because by dimensional reduction every spherically symmetric, four-dimensional (4D) black hole admits a 2D description, the method can be also used to construct analogue models of 4D black holes. We also show that after fixing the gauge degrees of freedom the 2D gravitational dynamics is equivalent to an one-dimensional fluid dynamics. This enables us to find a natural definition of mass $M$, temperature $T$ and entropy $S$ of the acoustic black hole. In particular the first principle of thermodynamics $dM=TdS$ becomes a consequence of the fluid dynamics equations. We also discuss the general solutions of the fluid dynamics and two particular cases, the 2D Anti-de sitter black hole and the 4D Schwarzschild black hole.

Mariano Cadoni

2004-10-28T23:59:59.000Z

200

Generalized Stochastic Gradient Learning  

E-Print Network (OSTI)

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

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

2006-03-14T23:59:59.000Z

Note: This page contains sample records for the topic "temperature gradient holes" 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

Black Hole Thermodynamics and Statistical Mechanics  

E-Print Network (OSTI)

We have known for more than thirty years that black holes behave as thermodynamic systems, radiating as black bodies with characteristic temperatures and entropies. This behavior is not only interesting in its own right; it could also, through a statistical mechanical description, cast light on some of the deep problems of quantizing gravity. In these lectures, I review what we currently know about black hole thermodynamics and statistical mechanics, suggest a rather speculative "universal" characterization of the underlying states, and describe some key open questions.

Steven Carlip

2008-07-28T23:59:59.000Z

202

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

203

Cold Black Holes in the Einstein-Scalar Field System  

E-Print Network (OSTI)

We study Einstein gravity coupled to a massless scalar field in a static spherically symmetric space-time in four dimensions. Black hole solutions exist when the kinetic energy of the scalar field is negative, that is, for a phantom field. These scalar black holes have an infinite horizon area and zero temperature. They are related through a conformal transformation with similar objects in the Jordan frames of scalar-tensor theories of gravity. The thermodynamical properties of these solutions are discussed. It is proved that any static, spherically symmetric black holes with an infinite horizon area have zero Hawking temperature.

K. A. Bronnikov; J. C. Fabris; N. Pinto-neto; M. E. Rodrigues; Icra-cbpf Rua Xavier Sigaud

2008-01-01T23:59:59.000Z

204

Thermodynamics of an Evaporating Schwarzschild Black Hole in Noncommutative Space  

E-Print Network (OSTI)

We investigate the effects of space noncommutativity and the generalized uncertainty principle on the thermodynamics of a radiating Schwarzschild black hole. We show that evaporation process is in such a way that black hole reaches to a maximum temperature before its final stage of evolution and then cools down to a nonsingular remnant with zero temperature and entropy. We compare our results with more reliable results of string theory. This comparison Shows that GUP and space noncommutativity are similar concepts at least from view point of black hole thermodynamics.

Kourosh Nozari; Behnaz Fazlpour

2006-05-11T23:59:59.000Z

205

Black Hole Shadows of Charged Spinning Black Holes  

E-Print Network (OSTI)

We propose a method for measuring the black hole charge by imaging a black hole shadow in a galactic center by future interferometers. Even when the black hole is uncharged, it is possible to confirm the charge neutrality by this method. We first derive the analytic formulae of the black hole shadow in an optically thin medium around a charged spinning black hole, and then investigate how contours of the black hole shadow depend on the spin and the charge of the black hole for several inclination angles between the rotation axis of the black hole and the observer. This method only assumes stationary black hole and general relativity. By fitting the formula of the contours of the shadow to the observed image of the shadow, in addition to the black hole charge, one can also determine the black hole spin and the inclination angle without any degeneracy among the charge, the spin, and the inclination angle unless the inclination angle is null. If the maximum width of the shadow smaller than 4(1 + 2 1/2)M or the minimum width of the shadow smaller than 9M are measured observationally, we can safely conclude that the black hole is charged. Here, M is the gravitational radius, i.e. the half of the Schwarzschild radius. Key words: black hole physicsGalaxy: nucleusgalaxies: nuclei techniques: high angular resolutiontechniques: interferometric 1.

Rohta Takahashi

2005-01-01T23:59:59.000Z

206

Black-hole astrophysics  

SciTech Connect

Black-hole astrophysics is not just the investigation of yet another, even if extremely remarkable type of celestial body, but a test of the correctness of the understanding of the very properties of space and time in very strong gravitational fields. Physicists` excitement at this new prospect for testing theories of fundamental processes is matched by that of astronomers at the possibility to discover and study a new and dramatically different kind of astronomical object. Here the authors review the currently known ways that black holes can be identified by their effects on their neighborhood--since, of course, the hole itself does not yield any direct evidence of its existence or information about its properties. The two most important empirical considerations are determination of masses, or lower limits thereof, of unseen companions in binary star systems, and measurement of luminosity fluctuations on very short time scales.

Bender, P. [Univ. of Colorado, Boulder, CO (United States); Bloom, E. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Cominsky, L. [Sonoma State Univ., Rohnert Park, CA (United States). Dept. of Physics and Astronomy] [and others

1995-07-01T23:59:59.000Z

207

Core Holes | Open Energy Information  

Open Energy Info (EERE)

Core Holes Core Holes Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Core Holes Details Activities (8) Areas (7) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Drilling Techniques Exploration Sub Group: Exploration Drilling Parent Exploration Technique: Exploration Drilling Information Provided by Technique Lithology: Core holes are drilled to identify lithology and mineralization Stratigraphic/Structural: Retrieved samples can be used to identify fracture networks or faults Hydrological: Thermal: Thermal conductivity measurements can be done on retrieved samples. Dictionary.png Core Holes: A core hole is a well that is drilled using a hallow drill bit coated with synthetic diamonds for the purposes of extracting whole rock samples from

208

Low-temperature geothermal resource and stratigraphy of portions of Yakima County, Washington  

DOE Green Energy (OSTI)

The low-temperature geothermal resource of portions of Yakima County, south-central Washington, is defined by several least squares linear regression analyses of bottom-hole temperature and depth data. Intra-borehole flow prevents the use of borehole temperature gradients for geothermal resource assessment. Bottom-hole temperature and depth data were separated into fourteen well data groups based on geographic proximity, land slope azimuth, and position within the regional ground-water flow system. The regression analyses of these well data groups indicate that the projected land-surface temperature and geothermal gradient range from 10.6 to 14.0/sup 0/C and from 24.9 to 52.2/sup 0/C/km, respectively. The depth to the 20/sup 0/C isotherm ranges from 142 to 346m. The average projected land-surface temperature and geothermal gradient are approximately 11.3/sup 0/C and 43.0/sup 0/C/km, respectively. The average depth to the 20/sup 0/C isoterm is approximately 202m. The projected land-surface temperature appears to decrease and the depth to the 20/sup 0/C isotherm appears to increase as the land-surface elevation of the well dat group increases. Stratigraphic correlation diagrams developed from borehole geophysical and lithologic logs are given for localities within the lower Yakima, Black Rock, Moxee, Ahtanum, Cowiche, and Naches valleys. These correlation diagrams are combined with their respective borehole temperatue logs and well data group predicted temperature curves to assess the validity of the regression analyses and to determine aquifer locations, temperatures, and directions of intra-borehole flow.

Biggane, J.

1982-07-30T23:59:59.000Z

209

Information transfer from black holes via white holes  

E-Print Network (OSTI)

It is shown that a black hole can be in two states: one with positive and other with negative surface gravity $k$. The state with $kinformation loss. In the quantization of black hole area the surface of a black hole is divided into a system of independent patches, each of which can be in two states: one with $k>0$ and other with $kinformation can be recovered from the black hole.

K. Ropotenko

2013-09-05T23:59:59.000Z

210

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

211

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

212

Low-temperature geothermal resource and stratigraphy of portions of Yakima County, Washington  

DOE Green Energy (OSTI)

The low-temperature geothermal resource of portions of Yakima County, south-central Washington, is defined by several least squares linear regression analyses of bottom-hole temperature and depth data. Bottom-hole temperature and depth data were separated into fourteen well data groups based on geographic proximity, land slope azimuth, and position within the regional ground-water flow system. The depths of these wells range from over 50m to almost 600m. The regression analyses of these well data groups indicate that the projected land-surface temperature and geothermal gradient range from 10.6 to 14.0/sup 0/C and from 24.9 to 52.2/sup 0/C/km, respectively. Stratigraphic correlation diagrams developed from borehole geophysical and lithologic logs are given for localities within the lower Yakima, Black Rock, Moxee, Ahtanum, Cowiche, and Naches valleys. These correlation diagrams are combined with their respective borehole temperature logs and well data group predicted temperature curves to assess the validity of the regression analyses and to determine aquifer locations, temperatures, and directions of intra-borehole flow. A regression analysis of data from wells of south-central Washington with bottom-hole depths of over 700m to almost 3km suggests that the projected land-surface temperature and geothermal gradient of this depth interval are 21.8/sup 0/C and 31.3/sup 0/C/km, respectively. The depth to the 100/sup 0/C isotherm is approximately 2513m.

Biggane, J.

1982-07-30T23:59:59.000Z

213

Annihilation Emission from the Galactic Black Hole  

E-Print Network (OSTI)

Both diffuse high energy gamma-rays and an extended electron-positron annihilation line emission have been observed in the Galactic Center (GC) region. Although X-ray observations indicate that the galactic black hole Sgr A$^*$ is inactive now, we suggest that Sgr A$^*$ can become active when a captured star is tidally disrupted and matter is accreted into the black hole. As a consequence the galactic black hole could be a powerful source of relativistic protons. We are able to explain the current observed diffuse gamma-rays and the very detailed 511 keV annihilation line of secondary positrons by $p-p$ collisions of such protons, with appropriate injection times and energy. Relativistic protons could have been injected into the ambient material if the black hole captured a 50M$_\\odot$ star at several tens million years ago. An alternative possibility is that the black hole continues to capture stars with $\\sim$1M$_\\odot$ every hundred thousand years. Secondary positrons produced by $p-p$ collisions at energies $\\ga 30$ MeV are cooled down to thermal energies by Coulomb collisions, and annihilate in the warm neutral and ionized phases of the interstellar medium with temperatures about several eV, because the annihilation cross-section reaches its maximum at these temperatures. It takes about ten million years for the positrons to cool down to thermal temperatures so they can diffuse into a very large extended region around the Galactic center. A much more recent star capture may be also able to account for recent TeV observations within 10 pc of the galactic center as well as for the unidentified GeV gamma-ray sources found by EGRET at GC. The spectral difference between the GeV flux and the TeV flux could be explained naturally in this model as well.

K. S. Cheng; D. O. Chernyshov; V. A. Dogiel

2006-03-24T23:59:59.000Z

214

String-Corrected Black Holes  

E-Print Network (OSTI)

for black holes and strings, Phys. Rev. D 55, 6189 (1997) [black holes and elementary string states, Mod. Phys. Lett. A= 2 supergravity and Calabi-Yau string back- grounds, Phys.

Hubeny, Veronika

2009-01-01T23:59:59.000Z

215

Einstein, Black Holes Gravitational Waves  

E-Print Network (OSTI)

1 #12;Einstein, Black Holes and Gravitational Waves Gregory B. Cook Wake Forest University 2 #12 Relativity? · What are some of the consequences of GR? · What are Black Holes like and do they exist? · What? · What are Black Holes like and do they exist? · What can we learn from Gravity Waves? · To do all

Cook, Greg

216

Acoustic black holes Matt Visser  

E-Print Network (OSTI)

Acoustic black holes Matt Visser Physics Department Washington University Saint Louis USA Ole Miss you develop a number of use- ful connections between supersonic uid ow and black holes in general is the basis underlying a deep and fruitful analogy between the black holes of Einstein gravity and supersonic

Visser, Matt

217

Numerical Simulations of Black Holes  

E-Print Network (OSTI)

Numerical Simulations of Black Holes 26 Aug 2009 Frank Herrmann (fherrman@umd.edu) Department · merger of compact objects Much more than just black hole evolutions · Formulations · Hyperboloidal)/2.0; . . . high arithmetic intensity Operator Number of times used 12,961 + 5,398 - 3,438 / 69 14 #12;Black Hole

Maryland at College Park, University of

218

"Exotic" black holes with torsion  

E-Print Network (OSTI)

In the context of three-dimensional gravity with torsion, the concepts of standard and "exotic" Banados-Teitelboim-Zanelli black holes are generalized by going over to black holes with torsion. This approach provides a unified insight into thermodynamics of black holes, with or without torsion.

Blagojevi?, M; Vasili?, M

2013-01-01T23:59:59.000Z

219

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

220

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...

Note: This page contains sample records for the topic "temperature gradient holes" 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

Black Holes and the Third Law of Thermodynamics  

E-Print Network (OSTI)

We discuss in the framework of black hole thermodynamics some aspects relative to the third law in the case of black holes of the Kerr-Newman family. In the light of the standard proof of the equivalence between the unattainability of the zero temperature and the entropic version of the third law it is remarked that the unattainability has a special character in black hole thermodynamics. Also the zero temperature limit which obtained in the case of very massive black holes is discussed and it is shown that a violation of the entropic version in the charged case occurs. The violation of the Bekenstein-Hawking law in favour of zero entropy SE = 0 in the case of extremal black holes is suggested as a natural solution for a possible violation of the second law of thermodynamics. Thermostatic arguments in support of the unattainability are explored, and SE = 0 for extremal black holes is shown to be again a viable solution. The third law of black hole dynamics by W.Israel is then interpreted as a further strong corroboration to the picture of a discontinuity between extremal states and non-extremal ones. PACS: 04.70.Dy, 05.70.-a 1.

F. Belgiorno; M. Martellini

2005-01-01T23:59:59.000Z

222

CFT Duals for Extreme Black Holes  

E-Print Network (OSTI)

It is argued that the general four-dimensional extremal Kerr-Newman-AdS-dS black hole is holographically dual to a (chiral half of a) two-dimensional CFT, generalizing an argument given recently for the special case of extremal Kerr. Specifically, the asymptotic symmetries of the near-horizon region of the general extremal black hole are shown to be generated by a Virasoro algebra. Semiclassical formulae are derived for the central charge and temperature of the dual CFT as functions of the cosmological constant, Newton's constant and the black hole charges and spin. We then show, assuming the Cardy formula, that the microscopic entropy of the dual CFT precisely reproduces the macroscopic Bekenstein-Hawking area law. This CFT description becomes singular in the extreme Reissner-Nordstrom limit where the black hole has no spin. At this point a second dual CFT description is proposed in which the global part of the U(1) gauge symmetry is promoted to a Virasoro algebra. This second description is also found to re...

Hartman, Thomas; Nishioka, Tatsuma; Strominger, Andrew

2009-01-01T23:59:59.000Z

223

CFT Duals for Extreme Black Holes  

E-Print Network (OSTI)

It is argued that the general four-dimensional extremal Kerr-Newman-AdS-dS black hole is holographically dual to a (chiral half of a) two-dimensional CFT, generalizing an argument given recently for the special case of extremal Kerr. Specifically, the asymptotic symmetries of the near-horizon region of the general extremal black hole are shown to be generated by a Virasoro algebra. Semiclassical formulae are derived for the central charge and temperature of the dual CFT as functions of the cosmological constant, Newton's constant and the black hole charges and spin. We then show, assuming the Cardy formula, that the microscopic entropy of the dual CFT precisely reproduces the macroscopic Bekenstein-Hawking area law. This CFT description becomes singular in the extreme Reissner-Nordstrom limit where the black hole has no spin. At this point a second dual CFT description is proposed in which the global part of the U(1) gauge symmetry is promoted to a Virasoro algebra. This second description is also found to reproduce the area law. Various further generalizations including higher dimensions are discussed.

Thomas Hartman; Keiju Murata; Tatsuma Nishioka; Andrew Strominger

2008-11-26T23:59:59.000Z

224

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.

225

Black Holes with Skyrme Hair  

E-Print Network (OSTI)

This paper is intended to give a review of the recent developments on black holes with Skyrme hair. The Einstein-Skyrme system is known to possess black hole solutions with Skyrme hair. The spherically symmetric black hole skyrmion with B=1 was the first discovered counter example of the no-hair conjecture for black holes. Recently we found the B=2 axially symmetric black hole skyrmion. In this system, the black hole at the center of the skyrmion absorbs the baryon number partially, leaving fractional charge outside the horizon. Therefore the baryon number is no longer conserved. We examine the B=1, 2 black hole solutions in detail in this paper. The model has a natural extension to the gauged version which can describe monopole black hole skyrmions. Callan and Witten discussed the monopole catalysis of proton decay within the Skyrme model. We apply the idea to the Einstein-Maxwell-Skyrme system and obtain monopole black hole skyrmions. Remarkably there exist multi-black hole skyrmion solutions in which the gravitational, electromagnetic, and strong forces between the monopoles are all in balance. The solutions turn out to be stable under spherically symmetric linear perturbations.

Noriko Shiiki; Nobuyuki Sawado

2005-01-09T23:59:59.000Z

226

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

227

Planning and drilling geothermal energy extraction hole EE-2: a precisely oriented and deviated hole in hot granitic rock  

DOE Green Energy (OSTI)

During the preceding work (Phase I) of the Hot Dry Rock (HDR) Geothermal Energy Project at Fenton Hill, two holes were drilled to a depth of nearly 3048 m (10,000 ft) and connected by a vertical hydraulic fracture. In this phase, water was pumped through the underground reservoir for approximately 417 days, producing an energy equivalent of 3 to 5 MW(t). Energy Extraction Hole No. 2 (EE-2) is the first of two deep holes that will be used in the Engineering-Resource Development System (Phase II) of the ongoing HDR Project of the Los Alamos National Laboratory. This phase of the work consists of drilling two parallel boreholes, inclined in their lower, open-hole sections at 35/sup 0/ to the vertical and separated by a vertical distance of 366 m (1200 ft) between the inclined parts of the drill holes. The holes will be connected by a series of vertical, hydraulically produced fractures in the Precambrian granitic rock complex. EE-2 was drilled to a depth of 4660 m (15,289 ft), where the bottom-hole temperature is approximately 320/sup 0/C (608/sup 0/F). Directional drilling techniques were used to control the azimuth and deviation of the hole. Upgrading of the temperature capability of existing hardware, and development of new equipment was necessary to complete the drilling of the hole in the extremely hot, hard, and abrasive granitic formation. The drilling history and the problems with bits, directional tools, tubular goods, cementing, and logging are described. A discussion of the problems and recommendations for overcoming them are also presented.

Helmick, C.; Koczan, S.; Pettitt, R.

1982-04-01T23:59:59.000Z

228

Information Storage in Black Holes  

E-Print Network (OSTI)

The information loss paradox for Schwarzschild black holes is examined, using the ADS/CFT correspondence extended to the $M_6 (4,2)$ bulk. It is found that the only option compatible with the preservation of the quantum unitarity is when a regular remnant region of the black hole survives to the black hole evaporation process, where information can be stored and eventually retrieved.

M. D. Maia

2005-05-23T23:59:59.000Z

229

Quantum Mechanics and Black Holes  

E-Print Network (OSTI)

This paper discusses the existence of black holes from the foundations of quantum mechanics. It is found that quantum mechanics rule out a possible gravitational collapse.

Jose N. Pecina-Cruz

2005-11-11T23:59:59.000Z

230

Higgs Boson Production from Black Holes at the LHC  

E-Print Network (OSTI)

If the fundamental Planck scale is near a TeV, then TeV scale black holes should be produced in proton-proton collisions at the LHC where \\sqrt{s} = 14 TeV. As the temperature of the black holes can be ~ 1 TeV we also expect production of Higgs bosons from them via Hawking radiation. This is a different production mode for the Higgs boson, which would normally be produced via direct pQCD parton fusion processes. In this paper we compare total cross sections and transverse momentum distributions d\\sigma/dp_T for Higgs production from black holes at the LHC with those from direct parton fusion processes at next-to-next-to-leading order and next-to-leading order respectively. We find that the Higgs production from black holes can be larger or smaller than the direct pQCD production depending upon the Planck mass and black hole mass. We also find that d\\sigma/dp_T of Higgs production from black holes increases as a function of p_T which is in sharp contrast with the pQCD predictions where d\\sigma/dp_T decreases so we suggest that the measurement of an increase in d\\sigma/dp_T as p_T increases for Higgs (or any other heavy particle) production can be a useful signature for black holes at the LHC.

Gouranga C. Nayak; J. Smith

2006-02-14T23:59:59.000Z

231

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

232

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. ...

233

Raft River Geothermal Exploratory Hole No. 3  

DOE Green Energy (OSTI)

Raft River Geothermal Exploratory Hole No. 3 (RRGE-3) is an exploratory hole with three directional legs, drilled to depths ranging from approximately 5,500 to 6,000 feet into intruded quartz monzonite basement rock of the Raft River valley of southeastern Idaho. The goal of the Raft River Geothermal R and D program is to determine the feasibility of developing and utilizing medium temperature (300/sup 0/F) geothermal resources for power generation and nonelectrical applications. This well was drilled to provide data to further investigate and evaluate the geothermal reservoir, as well as to optimize the location of possible future resource and/or injection wells and to develop methods to reduce the cost of geothermal wells. The drilling and completion of RRGE-3 is described and the daily drilling reports, drill bit records, descriptions of the casing, cementing, logging and coring programs, and the containment techniques employed on RRGE-3 are included.

Shoopman, H.H. (comp.)

1977-06-01T23:59:59.000Z

234

Use of slim holes for geothermal exploration and reservoir assessment: A preliminary report on Japanese experience  

DOE Green Energy (OSTI)

The publicly available Japanese data on the use of slim holes in geothermal exploration and reservoir assessment are reviewed in this report. Slim holes have been used for (1) obtaining core for geological studies, (2) delineating the stratigraphic structure, (3) characterizing reservoir fluid state (pressure, temperature, etc.), and (4) defining the permeability structure for reservoir assessment. Examples of these uses of slim hole data are presented from the Hohi Geothermal Area and the Sumikawa Geothermal Field. Discharge data from slim holes and production wells from the Oguni Geothermal Field indicate that it may be possible to infer the discharge rate of production wells based on slim hole measurements. The Japanese experience suggests that slim holes can provide useful data for cost-effective geothermal reservoir assessment. Therefore, plans for a full scale evaluation of Japanese slim hole data are outlined.

Garg, S.K. [S-Cubed, La Jolla, CA (United States); Combs, J. [Geo Hills Associates, Los Altos Hills, CA (United States)

1993-06-01T23:59:59.000Z

235

The Interplay Between Galaxies and Black Holes  

E-Print Network (OSTI)

The Interplay Between Galaxies and Black Holes A Theoretical Overview Massimo Ricotti (U · Formation of "Seed Black Holes" 1. Primordial Black Holes 2. Pop III Stars Remnants 3. Direct Collapse 4. Stellar Dynamics · Black Hole Growth 1. Gas Accretion vs BH-BH Mergers 2. Feeding Black Holes » M

Maryland at College Park, University of

236

Radiation of the Inner Horizon of the Reissner-Nordstrm Black Hole  

E-Print Network (OSTI)

Despite of over thirty years of research of the black hole thermodynamics our understanding of the possible role played by the inner horizons of Reissner-Nordstr\\"om and Kerr-Newman black holes in black hole thermodynamics is still somewhat incomplete: There are derivations which imply that the temperature of the inner horizon is negative and it is not quite clear what this means. Motivated by this problem we perform a detailed analysis of the radiation emitted by the inner horizon of the Reissner-Nordstr\\"om black hole. As a result we find that in a maximally extended Reissner-Nordstr\\"om spacetime virtual particle-antiparticle pairs are created at the inner horizon of the Reissner-Nordstr\\"om black hole such that real particles with positive energy and temperature are emitted towards the singularity from the inner horizon and, as a consequence, antiparticles with negative energy are radiated away from the singularity through the inner horizon. We show that these antiparticles will come out from the white hole horizon in the maximally extended Reissner-Nordstr\\"om spacetime, at least when the hole is near extremality. The energy spectrum of the antiparticles leads to a positive temperature for the white hole horizon. In other words, our analysis predicts that in addition to the radiation effects of black hole horizons, also the white hole horizon radiates. The black hole radiation is caused by the quantum effects at the outer horizon, whereas the white hole radiation is caused by the quantum effects at the inner horizon of the Reissner-Nordstr\\"om black hole.

A. Peltola; J. Makela

2005-08-23T23:59:59.000Z

237

Nonlinear Electrodynamics and black holes  

E-Print Network (OSTI)

It is addressed the issue of black holes with nonlinear electromagnetic field, focussing mainly in the Born-Infeld case. The main features of these systems are described, for instance, geodesics, energy conditions, thermodynamics and isolated horizon aspects. Also are revised some black hole solutions of alternative nonlinear electrodynamics and its inconveniences.

Nora Breton; Ricardo Garcia-Salcedo

2007-02-01T23:59:59.000Z

238

Cold Black Holes in the Einstein-Scalar Field System  

E-Print Network (OSTI)

We study Einstein gravity coupled to a massless scalar field in a static spherically symmetric space-time in four dimensions. Black hole solutions exist when the kinetic energy of the scalar field is negative, that is, for a phantom field. These ``scalar black holes'' have an infinite horizon area and zero temperature. They are related through a conformal transformation with similar objects in the Jordan frames of scalar-tensor theories of gravity. The thermodynamical properties of these solutions are discussed. It is proved that any \\ssph \\bhs with an infinite horizon area have zero Hawking temperature.

K. A. Bronnikov; J. C. Fabris; N. Pinto-Neto; M. E. Rodrigues

2006-04-11T23:59:59.000Z

239

Definition: Core Holes | Open Energy Information  

Open Energy Info (EERE)

Holes Jump to: navigation, search Dictionary.png Core Holes A core hole is a well that is drilled using a hallow drill bit coated with synthetic diamonds for the purposes of...

240

Black holes, AdS, and CFTs  

E-Print Network (OSTI)

count all states inside the black hole, but only those thatis the bag of gold? . . . . . Black hole entropy AdS/CFT 12000) [arXiv:hep-th/9911230] Black holes, AdS, and CFTs 11.

Marolf, Donald

2009-01-01T23:59:59.000Z

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


241

Spectral hole burning for stopping light  

E-Print Network (OSTI)

We propose a novel protocol for storage and retrieval of photon wave packets in a $\\Lambda$-type atomic medium. This protocol derives from spectral hole burning and takes advantages of the specific properties of solid state systems at low temperature, such as rare earth ion doped crystals. The signal pulse is tuned to the center of the hole that has been burnt previously within the inhomogeneously broadened absorption band. The group velocity is strongly reduced, being proportional to the hole width. This way the optically carried information and energy is carried over to the off-resonance optical dipoles. Storage and retrieval are performed by conversion to and from ground state Raman coherence by using brief $\\pi$-pulses. The protocol exhibits some resemblance with the well known electromagnetically induced transparency process. It also presents distinctive features such as the absence of coupling beam. In this paper we detail the various steps of the protocol, summarize the critical parameters and theoretically examine the recovery efficiency.

R. Lauro; T. Chaneliere; J. -L. Le Gouet

2009-02-16T23:59:59.000Z

242

Black hole remnant of black hole-neutron star coalescing binaries with arbitrary black hole spin  

E-Print Network (OSTI)

A model for determining the dimensionless spin parameter and mass of the black hole remnant of black hole-neutron star mergers with arbitrary initial black hole spin angular momentum, binary mass ratio, and neutron star mass and cold equation of state is formulated. Tests against numerical-relativity results are carried out, showing that both the dimensionless spin parameter and the final mass are accurately reproduced. For the first time, the behaviour of both quantities and of the l = 2, m = 2, n = 0 quasinormal mode frequency is inspected throughout the parameter space. Predictions of this frequency may be exploited to guide gravitational wave modelling and detection efforts, and to extract physical information from detected gravitational wave signals that would help us break degeneracies between binary black hole and black hole-neutron star systems, improve our understanding of compact binary formation, and constrain the neutron star equation of state.

Francesco Pannarale

2013-11-22T23:59:59.000Z

243

Cooper pairing near charged black holes  

E-Print Network (OSTI)

We show that a quartic contact interaction between charged fermions can lead to Cooper pairing and a superconducting instability in the background of a charged asymptotically Anti-de Sitter black hole. For a massless fermion we obtain the zero mode analytically and compute the dependence of the critical temperature T_c on the charge of the fermion. The instability we find occurs at charges above a critical value, where the fermion dispersion relation near the Fermi surface is linear. The critical temperature goes to zero as the marginal Fermi liquid is approached, together with the density of states at the Fermi surface. Besides the charge, the critical temperature is controlled by a four point function of a fermionic operator in the dual strongly coupled field theory.

Hartman, Thomas

2010-01-01T23:59:59.000Z

244

Cooper pairing near charged black holes  

E-Print Network (OSTI)

We show that a quartic contact interaction between charged fermions can lead to Cooper pairing and a superconducting instability in the background of a charged asymptotically Anti-de Sitter black hole. For a massless fermion we obtain the zero mode analytically and compute the dependence of the critical temperature T_c on the charge of the fermion. The instability we find occurs at charges above a critical value, where the fermion dispersion relation near the Fermi surface is linear. The critical temperature goes to zero as the marginal Fermi liquid is approached, together with the density of states at the Fermi surface. Besides the charge, the critical temperature is controlled by a four point function of a fermionic operator in the dual strongly coupled field theory.

Thomas Hartman; Sean A. Hartnoll

2010-03-09T23:59:59.000Z

245

Extracting black hole physics from the lattice  

E-Print Network (OSTI)

We perform lattice simulations of N D0-branes at finite temperature in the decoupling limit, namely 16 supercharge SU(N) Yang-Mills quantum mechanics in the 't Hooft limit. At low temperature this theory is conjectured to be dual to certain supergravity black holes. We emphasize that the existence of a non-compact moduli space renders the partition function of the quantum mechanics theory divergent, and we perform one loop calculations that demonstrate this explicitly. In consequence we use a scalar mass term to regulate this divergence and argue that the dual black hole thermodynamics may be recovered in the appropriate large N limit as the regulator is removed. We report on simulations for N up to 5 including the Pfaffian phase, and N up to 12 in the phase quenched approximation. Interestingly, in the former case, where we may calculate this potentially difficult phase, we find that it appears to play little role dynamically over the temperature range tested, which is certainly encouraging for future simulations of this theory.

Simon Catterall; Toby Wiseman

2009-09-27T23:59:59.000Z

246

Thermoelectric performance of electron and hole doped PtSb2  

Science Conference Proceedings (OSTI)

We investigate the thermoelectric properties of electron and hole doped PtSb2. Our results show that for doping of 0.04 holes per unit cell (1:5 1020 cm 3) PtSb2 shows a high Seebeck coefficient at room temperature, which can also be achieved at other temperatures by controlling the carrier concentration (both electron and hole). The electrical conductivity becomes temperature independent when the doping exceeds some 0.2 electrons/holes per unit cell. The figure of merit at 800 K in electron and hole doped PtSb2 is comparatively low at 0.13 and 0.21, respectively, but may increase significantly with As alloying due to the likely opening of a band gap and reduction of the lattice thermal conductivity

Saeed, Yasir [King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia; Singh, Nirprenda [King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia; Schwingenschlogl, Udo [King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia; Parker, David S [ORNL

2013-01-01T23:59:59.000Z

247

Black Hole Remnants and Dark Matter  

DOE Green Energy (OSTI)

We argue that, when the gravity effect is included, the generalized uncertainty principle (GUP) may prevent black holes from total evaporation in a similar way that the standard uncertainty principle prevents the hydrogen atom from total collapse. Specifically we invoke the GUP to obtain a modified Hawking temperature, which indicates that there should exist non-radiating remnants (BHR) of about Planck mass. BHRs are an attractive candidate for cold dark matter. We investigate an alternative cosmology in which primordial BHRs are the primary source of dark matter.

Chen, Pisin

2002-07-31T23:59:59.000Z

248

Slim Holes At Alvord Hot Springs Area (Combs, Et Al., 1999) | Open Energy  

Open Energy Info (EERE)

Combs, Et Al., 1999) Combs, Et Al., 1999) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Alvord Hot Springs Area (Combs, Et Al., 1999) Exploration Activity Details Location Alvord Hot Springs Area Exploration Technique Slim Holes Activity Date Usefulness not indicated DOE-funding Unknown Notes Anadarko Petroleum Corporation drilled two slimhole discoveries in the 1980s, one at Salt Wells, NV, and the other at Pueblo Valley, OR. Both of these slimholes were hot enough to discharge unassisted and were successfully flow tested. A slimhole at Pueblo Valley, in south-east Oregon was planned and permitted as a test well to evaluate an interval of fractured basalt which had been discovered while drilling an earlier thermal-gradient hole. Using a UDR1500 rig, the hole was rotary-drilled to

249

Charged fermion tunnelling from electrically and magnetically charged rotating black hole in de Sitter space  

E-Print Network (OSTI)

Thermal radiation of electrically charged fermions from rotating black hole with electric and magnetic charges in de Sitter space is considered. The tunnelling probabilities for outgoing and incoming particles are obtained and the Hawking temperature is calculated. The relation for the classical action for the particles in the black hole's background is also found.

M. M. Stetsko

2013-06-10T23:59:59.000Z

250

Fishing in Black Holes  

E-Print Network (OSTI)

The coordinate system $(\\bar{x},\\bar{t})$ defined by $r = 2m + K\\bar{x}- c K \\bar{t}$ and $t=\\bar{x}/cK - 1 /cK \\int_{r_a}^r (1- 2m/r + K^2)^{1/2} (1 - 2m/r)^{-1}dr$ allow us to write the Schwarzschild metric in the form: \\[ds^2=c^2 d\\bar{t}^2 + (W^2/K^2 - 2W/K) d\\bar{x}^2 + 2c (1 + W/K) d\\bar{x}d\\bar{t} - r^2 (d\\theta^2 + cos^2\\theta d\\phi^2)\\] with $W=(1 - 2m/r + K^2)^{1/2}$, in which the coefficients' pathologies are moved to $r_K = 2m/(1+K^2)$. This new coordinate system is used to study the entrance into a black hole of a rigid line (a line in which the shock waves propagate with velocity c).

A. Brotas

2006-09-01T23:59:59.000Z

251

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

252

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.

253

Life in a Tree Hole  

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

Tree Hole Tree Hole Nature Bulletin No. 581 November 21, 1959 Forest Preserve District of Cook County Daniel Ryan, President Roberts Mann, Conservation Editor David H Thompson, Senior Naturalist LIFE IN A TREE HOLE A forest is much more than just trees. It includes all of the underbrush, wildflowers and other vegetation that grow beneath these trees; as well as all of its animal life, both large and small. Sunshine, rain, wind, soil, and the leaf litter on the ground are part of it, too. A forest is a community -- a fabric in which the lives of its inhabitants are woven together and into their surroundings by a complex web of interrelations. Tree holes -- together with the birds, mammals and small life which they shelter -- furnish an important binding force in this forest community.

254

Black Holes in Brane Worlds  

E-Print Network (OSTI)

In a Randall-Sundrum theory (RS1) 3+1 dimensional black holes and higher dimensional black holes are not the natural continuations of each other. 3+1 dimensional black holes decay into a large number of 4+1 dimensional black holes at a critical mass, Mcrit ? 10 32 TeV. Those black holes themselves may become unstable above another, albeit much smaller critical mass, M0 ? 10 3 TeV. Models of the universe with extra dimensions larger than the Planck length have been under intense investigation during the last few years [1, 2, 3, 4]. The general feature of these models is that standard model particles are compelled to live on 3-branes, to satisfy momentum conservation in 3+1 dimensions and to conform to other phenomenological bounds, while gravity pervades all dimensions. Many of these models predict the observation of black holes at future accelerators [1, 5, 6, 7]. The models either use flat but compact extra dimensions(ADD scenario) [1] or a number of branes embedded in AdS space, with warped extra dimension(s) [2, 3]. Black holes in theories with extra dimensions have been studied widely. The classic paper of Myers and Perry [8] found solutions in D-dimensional flat space. Black hole solutions were also found in AdS space [9, 10]. No non-trivial black hole solutions have been found in closed form in brane theories of the Randall Sundrum type. Yet, it is important to learn as much as possible about black holes in such models. The black string solution [11] that extends in a uniform manner from the brane into the extra dimension has the Gregory-Laflamme instability in the ADD scenario [11, 12]. It is easy to invoke an entropy argument [13], to show that an instability will occur at a critical mass. An alternative interpretation is given in [14]. To understand the arguments by Gregory and Laflamme, compare the entropies of standard 3+1 and 4+1 dimensional Schwarzschild black holes of the same mass. Then one obtains a critical mass

P. Suranyi; L. C. R. Wijewardhana; Mcrit M

2008-01-01T23:59:59.000Z

255

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

256

Are Black Holes Elementary Particles?  

E-Print Network (OSTI)

Quantum black holes are the smallest and heaviest conceivable elementary particles. They have a microscopic size but a macroscopic mass. Several fundamental types have been constructed with some remarkable properties. Quantum black holes in the neighborhood of the Galaxy could resolve the paradox of ultra-high energy cosmic rays detected in Earths atmosphere. They may also play a role as dark matter in cosmology. 1 1

Yuan K. Ha

2009-01-01T23:59:59.000Z

257

Low-to-moderate temperature geothermal resource assessment for Nevada: Area specific studies, final report for the period June 1, 1980-August 30, 1981  

DOE Green Energy (OSTI)

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

Trexler, Dennis T.; Koeing, Brian A.; Flynn, Thomas; Bruce, James L.; Ghusn, George Jr.

1981-08-30T23:59:59.000Z

258

PERSPECTIVE Quantum Mechanics of Black Holes  

E-Print Network (OSTI)

PERSPECTIVE Quantum Mechanics of Black Holes Edward Witten The popular conception of black holes reflects the behavior of the massive black holes found by astronomers and described by classical general to understand the behavior of black holes from a quantum mechanical point of view, however, have arrived

259

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

260

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

Note: This page contains sample records for the topic "temperature gradient holes" 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

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

262

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

263

Regular black hole in three dimensions  

E-Print Network (OSTI)

We find a new black hole in three dimensional anti-de Sitter space by introducing an anisotropic perfect fluid inspired by the noncommutative black hole. This is a regular black hole with two horizons. We compare thermodynamics of this black hole with that of non-rotating BTZ black hole. The first-law of thermodynamics is not compatible with the Bekenstein-Hawking entropy.

Yun Soo Myung; Myungseok Yoon

2008-10-01T23:59:59.000Z

264

Preliminary results and status report of the Hawaiian Scientific Observation Hole program  

DOE Green Energy (OSTI)

The Hawaii Natural Energy Institute (HNEI), an institute within the School of Ocean and Earth Science and Technology, at the University of Hawaii at Manoa has drilled three Scientific Observation Holes (SOH) in the Kilauea East Rift Zone to assess the geothermal potential of the Big Island of Hawaii, and to stimulate private development of the resource. The first hole drilled, SOH-4, reached a depth of 2,000 meters and recorded a bottom hole temperature of 306 C. Although evidence of fossil reservoir conditions were encountered, no zones with obvious reservoir potential were found. The second hole, SOH- 1, was drilled to a depth of 1,684 meters, recorded a bottom hole temperature of 206.1 C and effectively defined the northern limit of the Hawaii Geothermal Project-Abbott--Puna Geothermal Venture (HGP-A/PGV) reservoir. The final hole, SOH-2, was drilled to a depth of 2,073 meters, recorded a bottom hole temperature of 350.5 C and has sufficient indicated permeability to be designated as a potential ''discovery''. The SOH program was also highly successful in developing slim hole drilling techniques and establishing subsurface geological conditions.

Olson, Harry J.; Deymonaz, John E.

1992-01-01T23:59:59.000Z

265

Geological and geophysical analysis of Coso Geothermal Exploration Hole No. 1 (CGEH-1), Coso Hot Springs KGRA, California  

DOE Green Energy (OSTI)

The Coso Geothermal Exploration Hole number one (CGEH-1) was drilled in the Coso Hot Springs KGRA, California, from September 2 to December 2, 1977. Chip samples were collected at ten foot intervals and extensive geophysical logging surveys were conducted to document the geologic character of the geothermal system as penetrated by CGEH-1. The major rock units encountered include a mafic metamorphic sequence and a leucogranite which intruded the metamorphic rocks. Only weak hydrothermal alteration was noted in these rocks. Drillhole surveys and drilling rate data indicate that the geothermal system is structurally controlled and that the drillhole itself was strongly influenced by structural zones. Water chemistry indicates that this geothermal resource is a hot-water rather than a vapor-dominated system. Several geophysical logs were employed to characcterize the drillhole geology. The natural gamma and neutron porosity logs indicate gross rock type and the accoustic logs indicate fractured rock and potentially permeable zones. A series of temperature logs run as a function of time during and after the completion of drilling were most useful in delineating the zones of maximum heat flux. Convective heat flow and temperatures greater than 350/sup 0/F appear to occur only along an open fracture system encountered between depths of 1850 and 2775 feet. Temperature logs indicate a negative thermal gradient below 3000 feet.

Galbraith, R.M.

1978-05-01T23:59:59.000Z

266

Hawking radiation via anomaly cancellation for the black holes of five-dimensional minimal gauged supergravity  

E-Print Network (OSTI)

The anomaly cancellation method proposed by Wilczek et al. is applied to the general charged rotating black holes in five-dimensional minimal gauged supergravity. Thus Hawking temperature and fluxes are found. The Hawking ...

Porfyriadis, Achilleas P.

267

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

268

Hole in the ozone layer?  

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

Hole in the ozone layer? Hole in the ozone layer? Name: Kelley Location: N/A Country: N/A Date: N/A Question: Is there really a hole in the ozone layer? Replies: That depends on what one means by a "hole". There is a thinning of the layer that is particularly severe during certain seasons at the poles. But the ozone layer is thinning most everywhere. The thinning around the south pole of earth is particularly stunning, and has been referred to as a hole even though some ozone still exists there, it is much less concentrated. As you may know, this ozone destruction is probably due to human release of pollutants such as clorofluorocarbons (CFCs) an due to natural sources such as chemicals from volcanic eruptions. CFCs are used is cooling systems such as refrigerators and air conditioning. There is an international agreement to phase out the use of these destructive chemicals but they won't be banned entirely for years for fears of losing money. Meanwhile the ozone layer thins and we are exposed to increasingly higher doses of cancer causing radiation

269

Area spectra of near extremal black holes and Kerr black holes  

E-Print Network (OSTI)

Motivated by Maggiore's new interpretation of quasinormal modes, starting from the first law of thermodynamics of black holes, we investigate area spectra of a near extremal Schwarzschild de sitter black hole and a higher dimensional near extremal Reissner-Nordstrom de sitter black hole. Then we apply the method to the Kerr black hole. We show that the logarithmic term does not appear and the area spectra of all these black holes are equally spaced and irrelevant to the parameters of black holes.

Chen, Deyou; Zu, Xiaotao

2010-01-01T23:59:59.000Z

270

Thermodynamic geometry of charged rotating BTZ black holes  

SciTech Connect

We study the thermodynamics and the thermodynamic geometries of charged rotating Banados-Teitelboim-Zanelli black holes in (2+1)-gravity. We investigate the thermodynamics of these systems within the context of the Weinhold and Ruppeiner thermodynamic geometries and the recently developed formalism of geometrothermodynamics. Considering the behavior of the heat capacity and the Hawking temperature, we show that Weinhold and Ruppeiner geometries cannot describe completely the thermodynamics of these black holes and of their limiting case of vanishing electric charge. In contrast, the Legendre invariance imposed on the metric in geometrothermodynamics allows one to describe the charged rotating Banados-Teitelboim-Zanelli black holes and their limiting cases in a consistent and invariant manner.

Akbar, M. [Center for Advanced Mathematics and Physics, National University of Sciences and Technology, H-12, Islamabad (Pakistan); Quevedo, H. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, AP 70543, Mexico, DF 04510 (Mexico); ICRANet, Dipartimento di Fisica, Universita di Roma La Sapienza, I-00185 Roma (Italy); Saifullah, K. [Department of Mathematics, Quaid-i-Azam University, Islamabad (Pakistan); Sanchez, A. [Departamento de Posgrado, CIIDET, AP 752, Queretaro, QRO 76000 (Mexico); Taj, S. [Center for Advanced Mathematics and Physics, National University of Sciences and Technology, H-12, Islamabad (Pakistan); ICRANet, Dipartimento di Fisica, Universita di Roma La Sapienza, I-00185 Roma (Italy)

2011-04-15T23:59:59.000Z

271

Thermodynamics of a charged hairy black hole in (2+1) dimensions  

E-Print Network (OSTI)

In this paper we study thermodynamics, statistics and spectroscopic aspects of a charged black hole with a scalar hair coupled to the gravity in (2+1) dimensions. We obtained effects of the black hole charge and scalar field on the thermodynamical and statistical quantities. We find that scalar charge may increase entropy, temperature and probability, while may decrease black hole mass, free and internal energy. Also electric charge increases probability and decreases temperature and internal energy. Also we investigate stability of the system and find that the thermodynamical stability exists.

J. Sadeghi; H. Farahani

2013-08-05T23:59:59.000Z

272

Schroedinger Equation of the Schwarzschild Black Hole  

E-Print Network (OSTI)

We describe the gravitational degrees of freedom of the Schwarzschild black hole by one free variable. We introduce an equation which we suggest to be the Schroedinger equation of the Schwarzschild black hole corresponding to this model. We solve the Schroedinger equation explicitly and obtain the mass spectrum of the black hole as such as it can be observed by an observer very far away and at rest relative to the black hole. Our equation implies that there is no singularity inside the Schwarzschild black hole, and that the black hole has a certain ground state in which its mass is non-zero.

Jarmo Makela

1996-02-05T23:59:59.000Z

273

Massive Black Holes: formation and evolution  

E-Print Network (OSTI)

Supermassive black holes are nowadays believed to reside in most local galaxies. Observations have revealed us vast information on the population of local and distant black holes, but the detailed physical properties of these dark massive objects are still to be proven. Accretion of gas and black hole mergers play a fundamental role in determining the two parameters defining a black hole: mass and spin. We briefly review here the basic properties of the population of supermassive black holes, focusing on the still mysterious formation of the first massive black holes, and their evolution from early times to now.

Martin J. Rees; Marta Volonteri

2007-01-17T23:59:59.000Z

274

Enhanced Black Hole Horizon Fluctuations  

E-Print Network (OSTI)

We discuss the possible role of quantum horizon fluctuations on black hole radiance, especially whether they can invalidate Hawking's analysis based upon transplanckian modes. We are particularly concerned with ``enhanced'' fluctuations produced by gravitons or matter fields in squeezed vacuum states sent into the black hole after the collapse process. This allows for the possibility of increasing the fluctuations well above the vacuum level. We find that these enhanced fluctuations could significantly alter stimulated emission but have little effect upon the spontaneous emission. Thus the thermal character of the Hawking radiation is remarkably robust.

R. T. Thompson; L. H. Ford

2008-03-13T23:59:59.000Z

275

Information Loss in Black Holes  

E-Print Network (OSTI)

The question of whether information is lost in black holes is investigated using Euclidean path integrals. The formation and evaporation of black holes is regarded as a scattering problem with all measurements being made at infinity. This seems to be well formulated only in asymptotically AdS spacetimes. The path integral over metrics with trivial topology is unitary and information preserving. On the other hand, the path integral over metrics with non-trivial topologies leads to correlation functions that decay to zero. Thus at late times only the unitary information preserving path integrals over trivial topologies will contribute. Elementary quantum gravity interactions do not lose information or quantum coherence.

S. W. Hawking

2005-07-18T23:59:59.000Z

276

Thermodynamic curvature and black holes  

E-Print Network (OSTI)

I give a relatively broad survey of thermodynamic curvature $R$, one spanning results in fluids and solids, spin systems, and black hole thermodynamics. $R$ results from the thermodynamic information metric giving thermodynamic fluctuations. $R$ has a unique status in thermodynamics as being a geometric invariant, the same for any given thermodynamic state. In fluid and solid systems, the sign of $R$ indicates the character of microscopic interactions, repulsive or attractive. $|R|$ gives the average size of organized mesoscopic fluctuating structures. The broad generality of thermodynamic principles might lead one to believe the same for black hole thermodynamics. This paper explores this issue with a systematic tabulation of results in a number of cases.

Ruppeiner, George

2013-01-01T23:59:59.000Z

277

Thermodynamic curvature and black holes  

E-Print Network (OSTI)

I give a relatively broad survey of thermodynamic curvature $R$, one spanning results in fluids and solids, spin systems, and black hole thermodynamics. $R$ results from the thermodynamic information metric giving thermodynamic fluctuations. $R$ has a unique status in thermodynamics as being a geometric invariant, the same for any given thermodynamic state. In fluid and solid systems, the sign of $R$ indicates the character of microscopic interactions, repulsive or attractive. $|R|$ gives the average size of organized mesoscopic fluctuating structures. The broad generality of thermodynamic principles might lead one to believe the same for black hole thermodynamics. This paper explores this issue with a systematic tabulation of results in a number of cases.

George Ruppeiner

2013-09-04T23:59:59.000Z

278

Geothermal modeling of Jackson Hole, Teton County Wyoming: Final report  

DOE Green Energy (OSTI)

This study investigated the possibility of high-temperature-heat sources (greater than 300/sup 0/C) in the area of Jackson Hole, northwestern Wyoming. Analytical and finite-difference numerical models describing conductive and convective terrestrial heat transport were utilized in an attempt to define the thermal regime of this area. This report presents data which were used as constraints for the analytic and numerical thermal models. These data include a general discussion of geology of the area, thermal spring information, subsurface temperature information, and hydrology of the area. Model results are presented with a discussion of interpretations and implications for the existence of high-temperature heat sources in the Jackson Hole area.

Heasler, H.P.

1987-04-01T23:59:59.000Z

279

Research on the Role of Control Hole in Deep-hole Pre-splitting Blasting in Outburst Coal Seams  

Science Conference Proceedings (OSTI)

Mechanical analysis model of blasting and controlling holes was set up combined with a gas outburst mine deep hole pre split blasting test, and the necessity of setting control hole in deep hole pre splitting blasting was analyzed. The theoretical calculation ... Keywords: outburst coal seams, deep-hole pre-splitting blasting, control hole, hole spacing

Gong Min; Liu You-ping

2012-05-01T23:59:59.000Z

280

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

Note: This page contains sample records for the topic "temperature gradient holes" 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

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...

282

Asymptotically Lifshitz brane-world black holes  

SciTech Connect

We study the gravity dual of a Lifshitz field theory in the context of a RSII brane-world scenario, taking into account the effects of the extra dimension through the contribution of the electric part of the Weyl tensor. We study the thermodynamical behavior of such asymptotically Lifshitz black holes. It is shown that the entropy imposes the critical exponent z to be bounded from above. This maximum value of z corresponds to a positive infinite entropy as long as the temperature is kept positive. The stability and phase transition for different spatial topologies are also discussed. - Highlights: Black-Right-Pointing-Pointer Studying the gravity dual of a Lifshitz field theory in the context of brane-world scenario. Black-Right-Pointing-Pointer Studying the thermodynamical behavior of asymptotically Lifshitz black holes. Black-Right-Pointing-Pointer Showing that the entropy imposes the critical exponent z to be bounded from above. Black-Right-Pointing-Pointer Discussing the phase transition for different spatial topologies.

Ranjbar, Arash, E-mail: a_ranjbar@sbu.ac.ir; Sepangi, Hamid Reza, E-mail: hr-sepangi@sbu.ac.ir; Shahidi, Shahab, E-mail: s_shahidi@sbu.ac.ir

2012-12-15T23:59:59.000Z

283

Electrical Generating Capacities of Geothermal Slim Holes  

DOE Green Energy (OSTI)

Theoretical calculations are presented to estimate the electrical generating capacity of the hot fluids discharged from individual geothermal wells using small wellhead generating equipment over a wide range of reservoir and operating conditions. The purpose is to appraise the possibility of employing slim holes (instead of conventional production-size wells) to power such generators for remote off-grid applications such as rural electrification in developing countries. Frequently, the generating capacity desired is less than one megawatt, and can be as low as 100 kilowatts; if slim holes can be usefully employed, overall project costs will be significantly reduced. This report presents the final results of the study. Both self-discharging wells and wells equipped with downhole pumps (either of the ''lineshaft'' or the ''submersible'' type) are examined. Several power plant designs are considered, including conventional single-flash backpressure and condensing steam turbines, binary plants, double-flash steam plants, and steam turbine/binary hybrid designs. Well inside diameters from 75 mm to 300 mm are considered; well depths vary from 300 to 1200 meters. Reservoir temperatures from 100 C to 240 C are examined, as are a variety of reservoir pressures and CO2 contents and well productivity index values.

Pritchett, J.W.

1998-10-01T23:59:59.000Z

284

Estimation of host rock thermal conductivities using the temperature data from the drift-scale test at Yucca Mountain, Nevada  

E-Print Network (OSTI)

the wing heaters, and the RTD temperature holes in the DSTtemperature devices (RTD) placed in 26 boreholes (Borehole

Mukhopadhyay, Sumitra; Tsang, Y.W.

2008-01-01T23:59:59.000Z

285

Black Hole's Life at colliders  

E-Print Network (OSTI)

In the series of papers by Ida, Oda and Park, the complete description of Hawking radiation to the brane localized Standard Model fields from mini black holes in the low energy gravity scenarios are obtained. Here we briefly review what we have learned in those papers.

Seong Chan Park

2007-04-09T23:59:59.000Z

286

Black Hole fragmentation and holography  

E-Print Network (OSTI)

We discuss the entropy change due to fragmentation for black hole solutions in various dimensions. We find three different types of behavior. The entropy may decrease, increase or have a mixed behavior, characterized by the presence of a threshold mass. For two-dimensional (2D) black holes we give a complete characterization of the entropy behavior under fragmentation, in the form of sufficient conditions imposed on the function J, which defines the 2D gravitational model. We compare the behavior of the gravitational solutions with that of free field theories in d dimensions. This excludes the possibility of finding a gravity/field theory realization of the holographic principle for a broad class of solutions, including asymptotically flat black holes. We find that the most natural candidates for holographic duals of the black hole solutions with mixed behavior are field theories with a mass gap. We also discuss the possibility of formulating entropy bounds that make reference only to the energy of a system.

Mariano Cadoni

2003-11-18T23:59:59.000Z

287

Brief History of Black-Holes  

E-Print Network (OSTI)

We show that the gravitational collapse of a black-hole terminates in the birth of a white-hole, due to repulsive gravitation (antigravitation); in particular, the infinite energy density singularity does NOT occur.

Marcelo Samuel Berman

2004-12-12T23:59:59.000Z

288

Does phantom energy produce black hole?  

E-Print Network (OSTI)

We have found an exact solution of spherically symmetrical Einstein equations describing a black hole with a special type phantom energy source. It is surprising to note that our solution is analogous to Reissner-Nordstr\\"{o}m black hole.

F. Rahaman; A. Ghosh; M. Kalam

2006-12-23T23:59:59.000Z

289

Spacetime and orbits of bumpy black holes  

E-Print Network (OSTI)

Our Universe contains a great number of extremely compact and massive objects which are generally accepted to be black holes. Precise observations of orbital motion near candidate black holes have the potential to determine ...

Vigeland, Sarah Jane

290

Use of slim holes for reservoir evaluation at the Steamboat Hills Geothermal Field, Nevada, USA  

SciTech Connect

Three slim holes were drilled at the Steamboat Hills Geothermal Field in northwestern Nevada about 15 km south of Reno. The slim holes were drilled to investigate the geologic conditions, thermal regime and productive characteristics of the geothermal system. They were completed through a geologic sequence consisting of alluvium cemented by geothermal fluids, volcaniclastic materials, and granodiorite. Numerous fractures, mostly sealed, were encountered throughout the drilled depth; however, several open fractures in the granodiorite, dipping between 65 and 90{degree}, had apertures up to 13 mm in width. The depths of the slim holes vary from 262 to 277 m with open-hole diameters of 76 mm. Pressure and temperature logs gave bottom-hole temperatures ranging from 163 to 166{degree} C. During injection testing, downhole pressures were measured using capillary tubing with a surface quartz transducer while temperatures were measured with a Kuster temperature tool located below the capillary tubing pressure chamber. No pressure increase was measured at reservoir depths in any of the three slim holes while injecting 11 kg/s of 29{degree}C water indicating a very high permeability in the geothermal reservoir. These injection test results suggested that productive geothermal fluids could be found at depths sufficient for well pumping equipment and at temperatures needed for electrical power production using binary-type conversion technology.

Combs, Jim; Goranson, Colin

1994-01-20T23:59:59.000Z

291

Steady and unsteady calibration of multi-hole probes  

E-Print Network (OSTI)

This thesis presents the development of a data crographics. reduction algorithm for multi-hole pressure probes. The algorithm has been developed for the reduction of calibration data from miniature non-nulling multi-hole probes in compressible, subsonic flow gelds. The algorithm is able to reduce data from any 5-or 7-hole probe in a subsonic flow field and generate very accurate predictions of the velocity magnitude and direction, total and static pressure, Mach and Reynolds member and fluid properties like the density and viscosity. The algorithm utilizes a local least-squares modeling technique and has been tested on 4 novel miniature 7-hole probes that have been calibrated at NASA Langley Flow Modeling and Control Branch for the entire subsonic regime. Each of the probes had a conical tip with diameter of 0.065''. Excellent prediction capabilities are demonstrated with maximum errors in angle prediction less than 0.6 degrees and maximum errors in velocity prediction less than 1%, both with 99 percent confidence. The development of Micro Electro Mechanical Systems (MEMS) -based, fast-response, multi-sensor pressure probes of miniature size for velocity and pressure measurement applications in unsteady and turbulent flow gelds is also discussed. A new type of pressure sensor has been developed with silicon-nitride diaphragm and a characteristic size of only 250 gm. These pressure sensors are small enough to be mounted close to the surface of a miniature hemispherical-tip probe, obtaining a probe bandwidth and a theoretical frequency response up to 100 kl-lz. Both computational and experimental approaches are employed to develop calibration techniques suitable for highly unsteady flow environments with strong spatial gradients.

Johansen, Espen S

1998-01-01T23:59:59.000Z

292

Growing Supermassive Black Holes by Chaotic Accretion  

E-Print Network (OSTI)

There is recent observational evidence (Barth et al., 2003, Willott et al, 2003) for supermassive black holes (SMBH)

A. R. King; J. E. Pringle

2006-01-01T23:59:59.000Z

293

Hawking Emission and Black Hole Thermodynamics  

E-Print Network (OSTI)

A brief review of Hawking radiation and black hole thermodynamics is given, based largely upon hep-th/0409024.

Don N. Page

2006-12-18T23:59:59.000Z

294

a BLACK HOLES AND FUNDAMENTAL PHYSICS  

E-Print Network (OSTI)

We give a review of classical, thermodynamic and quantum properties of black holes relevant to fundamental physics. 1.

Jos P. S. Lemos; Centro Multidisciplinar; Astrofsica Centra

2005-01-01T23:59:59.000Z

295

Rotating Black Holes in Higher Dimensions  

E-Print Network (OSTI)

The properties of higher-dimensional black holes can differ significantly from those of black holes in four dimensions, since neither the uniqueness theorem, nor the staticity theorem or the topological censorship theorem generalize to higher dimensions. We first discuss black holes of Einstein-Maxwell theory and Einstein-Maxwell-Chern-Simons theory with spherical horizon topology. Here new types of stationary black holes are encountered. We then discuss nonuniform black strings and present evidence for a horizon topology changing transition.

Burkhard Kleihaus; Jutta Kunz; Francisco Navarro-Lerida

2007-10-11T23:59:59.000Z

296

ACCRETION-JET CONNECTION IN BLACK HOLES THE ORIGIN OF STELLAR BLACK HOLES &  

E-Print Network (OSTI)

ACCRETION-JET CONNECTION IN BLACK HOLES THE ORIGIN OF STELLAR BLACK HOLES & THEIR ROLE a very large kinetic energy...Moon @ >.9c" #12;POWERFUL DARK JETS FROM BLACK HOLES Radio (Dubner et al IN BLACK HOLES Fender, Belloni, Gallo (2006) Low-hard X-rays Persistent, flat spectrum radio source: G

Maryland at College Park, University of

297

37Black Hole Power...X Black holes are sometimes surrounded  

E-Print Network (OSTI)

37Black Hole Power...X Black holes are sometimes surrounded by a disk of orbiting matter. This disk is very hot. As matter finally falls into the black hole from the inner edge of that disk, it releases the infalling matter is about 7% of its rest-mass in all forms (heat+ light). The power produced by a black hole

298

Geometric Approach to Hole Segmentation and Hole Closing in 3D Volumetric Objects  

Science Conference Proceedings (OSTI)

Hole segmentation (or hole filling) and hole closing in 3D volumetric objects, visualised in tomographic images, has many potential applications in material science and medicine. On the other hand there is no algorithm for hole segmentation in 3D volumetric ...

Marcin Janaszewski; Michel Couprie; Laurent Babout

2009-11-01T23:59:59.000Z

299

Supermassive Black Holes and the Warm Ionized  

E-Print Network (OSTI)

Supermassive Black Holes and the Warm Ionized Gas in Early-type Galaxies Renbin Yan University stars actively. (late-type galaxies) #12;Prevalence of Supermassive Black Holes in Massive Galaxies MBH merging Right after coalescing Post-merger Star Formation Rate Black Hole Accretion Rate #12;Maintenance

Wang, Ming-Jye

300

Accretion Processes in BlackHole Binaries  

E-Print Network (OSTI)

Accretion Processes in Black­Hole Binaries Roberto Soria A thesis submitted for the degree presented in ``Measuring the Mass of the Black Hole in GRO J1655\\Gamma40'', Soria, R., Wickramasinghe, D. T processes in black­hole bina­ ries, theoretically and observationally, focussing on the role of outflows

Soria, Roberto

Note: This page contains sample records for the topic "temperature gradient holes" 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

Charged Black Holes in New Massive Gravity  

E-Print Network (OSTI)

We construct charged black hole solutions to three-dimensional New Massive Gravity (NMG), by adding electromagnetic Maxwell and Chern-Simons actions. We find charged black holes in the form of warped AdS_3 and "log" solutions in specific critical point. The entropy, mass and angular momentum of these black holes are computed.

Ghodsi, Ahmad

2010-01-01T23:59:59.000Z

302

Gravitational lensing of STU black holes  

E-Print Network (OSTI)

In this paper we study gravitational lensing by STU black holes. We considered extremal limit of two special cases of zero-charged and one-charged black holes, and obtain the deflection angle. We find that the black hole charge increases the deflection angle.

Hassan Saadat

2013-06-03T23:59:59.000Z

303

Gravitational lensing of STU black holes  

E-Print Network (OSTI)

In this paper we study gravitational lensing by STU black holes. We considered extremal limit of two special cases of zero-charged and one-charged black holes, and obtain the deflection angle. We find that the black hole charge increases the deflection angle.

Saadat, Hassan

2013-01-01T23:59:59.000Z

304

Core Hole Drilling And Testing At The Lake City, California Geothermal  

Open Energy Info (EERE)

Hole Drilling And Testing At The Lake City, California Geothermal Hole Drilling And Testing At The Lake City, California Geothermal Field Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Core Hole Drilling And Testing At The Lake City, California Geothermal Field Details Activities (4) Areas (1) Regions (0) Abstract: Unavailable Author(s): Dick Benoit, Joe Moore, Colin Goranson, David Blackwell Published: GRC, 2005 Document Number: Unavailable DOI: Unavailable Core Analysis At Lake City Hot Springs Area (Benoit Et Al., 2005) Core Holes At Lake City Hot Springs Area (Benoit Et Al., 2005) Flow Test At Lake City Hot Springs Area (Benoit Et Al., 2005) Static Temperature Survey At Lake City Hot Springs Area (Benoit Et Al., 2005) Lake City Hot Springs Geothermal Area Retrieved from "http://en.openei.org/w/index.php?title=Core_Hole_Drilling_And_Testing_At_The_Lake_City,_California_Geothermal_Field&oldid=389996

305

Evaluation of Coso Geothermal Exploratory Hole No. 1 (CGEH-1) Coso Hot  

Open Energy Info (EERE)

Coso Geothermal Exploratory Hole No. 1 (CGEH-1) Coso Hot Coso Geothermal Exploratory Hole No. 1 (CGEH-1) Coso Hot Springs: KGRA, China Lake, CA Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Evaluation of Coso Geothermal Exploratory Hole No. 1 (CGEH-1) Coso Hot Springs: KGRA, China Lake, CA Details Activities (1) Areas (1) Regions (0) Abstract: The well, Coso Geothermal Exploratory Hole No. 1 (CGEH-1) was drilled at the China Lake Naval Weapons Center. Drilling was started on 2 September 1977, and the well completed on 1 December 1977 to 4845 ft. The well is an exploratory hole to determine geological and hydrothermal characteristics of the Coso Hot Springs KGRA (Known Geothermal Resource Area). During drilling, numerous geophysical and temperature surveys were performed to evaluate the geological characteristics of CGEH-1. LBL

306

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

307

Problem Statement: Energy Holes Energy Profiling & Proactive Reconfiguration: Overview  

E-Print Network (OSTI)

Problem Statement: Energy Holes Energy Profiling & Proactive Reconfiguration: Overview Holes the Energy Hole Problem of Nonuniform Node Distribution in Wireless Sensor Networks.", MASS 2006 [2 · Inherent nodes redundancy Spatially correlated energy consumption Energy holes are common in WSN Sink

Suri, Neeraj

308

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

309

Developing hot dry rock reservoirs with inflatable open hole packers  

DOE Green Energy (OSTI)

An open hole packer system was designed for high pressure injection operations in high temperature wells at the Fenton Hill, Hot Dry Rock (HDR) Geothermal Site. The packer runs were required to verify that the HDR reservoir fractures had been penetrated during the drilling of well EE-3A. They were also used to stimulate fractures connecting EE-3A to the reservoir and to conduct two massive hydraulic fracture treatments at the bottom of EE-3A. An attempt to use a modified packer design as a temporary well completion system was not successful but with modification the system may prove to be an important HDR completion technique. The eleven packer runs have demonstrated that formation testing, stimulation and HDR reservoir development can now be conducted with an open hole inflatable packer operating over large temperature ranges and high differential pressures.

Dreesen, D.S.; Miller, J.R.; Nicholson, R.W.

1987-01-01T23:59:59.000Z

310

Rotating Black Holes with Monopole Hair  

E-Print Network (OSTI)

We study rotating black holes in Einstein-Yang-Mills-Higgs theory. These black holes emerge from static black holes with monopole hair when a finite horizon angular velocity is imposed. At critical values of the horizon angular velocity and the horizon radius, they bifurcate with embedded Kerr-Newman black holes. The non-Abelian black holes possess an electric dipole moment, but no electric charge is induced by the rotation. We deduce that gravitating regular monopoles possess a gyroelectric ratio g_el=2.

B. Kleihaus; J. Kunz; F. Navarro-Lerida

2004-06-23T23:59:59.000Z

311

Black Hole Radiation and Volume Statistical Entropy  

E-Print Network (OSTI)

The simplest possible equation for Hawking radiation, and other black hole radiated power is derived in terms of black hole density. Black hole density also leads to the simplest possible model of a gas of elementary constituents confined inside a gravitational bottle of Schwarzchild radius at tremendous pressure, which yields identically the same functional dependence as the traditional black hole entropy. Variations of Sbh can be obtained which depend on the occupancy of phase space cells. A relation is derived between the constituent momenta and the black hole radius which is similar to the Compton wavelength relation.

Mario Rabinowitz

2005-06-03T23:59:59.000Z

312

Black holes: from stars to galaxies  

E-Print Network (OSTI)

While until recently they were often considered as exotic objects of dubious existence, in the last decades there have been overwhelming observational evidences for the presence of stellar mass black holes in binary systems, supermassive black holes at the centers of galaxies, and possibly, intermediate-mass black holes observed as ultraluminous X-ray sources in nearby galaxies. Black holes are now widely accepted as real physical entities that play an important role in several areas of modern astrophysics. Here I review the concluding remarks of the IAU Sympposium No 238 on Black Holes, with particular emphasis on the topical questions in this area of research.

I. F. Mirabel

2006-12-07T23:59:59.000Z

313

Accelerating and rotating black holes  

E-Print Network (OSTI)

An exact solution of Einstein's equations which represents a pair of accelerating and rotating black holes (a generalised form of the spinning C-metric) is presented. The starting point is a form of the Plebanski-Demianski metric which, in addition to the usual parameters, explicitly includes parameters which describe the acceleration and angular velocity of the sources. This is transformed to a form which explicitly contains the known special cases for either rotating or accelerating black holes. Electromagnetic charges and a NUT parameter are included, the relation between the NUT parameter $l$ and the Plebanski-Demianski parameter $n$ is given, and the physical meaning of all parameters is clarified. The possibility of finding an accelerating NUT solution is also discussed.

J. B. Griffiths; J. Podolsky

2005-07-06T23:59:59.000Z

314

Supermassive black holes from supermassive stars  

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

Supermassive black holes from supermassive stars Supermassive black holes from supermassive stars 1663 Los Alamos science and technology magazine Latest Issue:November 2013 All Issues » submit Supermassive black holes from supermassive stars Supermassive stars in the early universe gave supermassive black holes a head start March 25, 2013 simulations suggest that star formation conditions back then allowed the first stars to become supermassive themselves In this simulation, a black hole that was just formed by the collapse of a supermassive star is surrounded by a distribution of gas (color indicates density). Because the black hole (located at the center but too small to see) grows by consuming the available gas, simulations like this one help determine how quickly the black hole can grow. The progenitor of this black

315

Modeling Flows Around Merging Black Hole Binaries  

E-Print Network (OSTI)

Coalescing massive black hole binaries are produced by the mergers of galaxies. The final stages of the black hole coalescence produce strong gravitational radiation that can be detected by the space-borne LISA. In cases where the black hole merger takes place in the presence of gas and magnetic fields, various types of electromagnetic signals may also be produced. Modeling such electromagnetic counterparts of the final merger requires evolving the behavior of both gas and fields in the strong-field regions around the black holes. We have taken a step towards solving this problem by mapping the flow of pressureless matter in the dynamic, 3-D general relativistic spacetime around the merging black holes. We find qualitative differences in collision and outflow speeds, including a signature of the merger when the net angular momentum of the matter is low, between the results from single and binary black holes, and between nonrotating and rotating holes in binaries. If future magnetohydrodynamic results confirm ...

van Meter, James R; Miller, M Coleman; Reynolds, Christopher S; Centrella, Joan M; Baker, John G; Boggs, William D; Kelly, Bernard J; McWilliams, Sean T

2009-01-01T23:59:59.000Z

316

Predicting hole enlargement from drilling parameters  

Science Conference Proceedings (OSTI)

This article points out that most problems associated with inadequate hole cleaning stem from hole enlargement. Lower annular velocities are required if no enlargement occurs. However, hole enlargement is often significant and can reduce annular velocities below the critical values. A simple approach is performed to predict well bore hole enlargement from drilling parameters. While the equipment and techniques are available to control mud weight going into the hole, the annular mud weight may become excessive. This annular mud weight is utilized to predict hole enlargement. A balance of the mass rate of cuttings generated and the mass rate of mud pumped is performed in order to predict hole enlargement. Data required for this procedure are inlet mud density, outlet mud density, average formation density, average formation porosity, bit size, mud flow rate and the rate of penetration.

Bizanti, M.S.

1987-01-01T23:59:59.000Z

317

Core hole drilling and the ''rain current'' phenomenon at Newberry Volcano, Oregon  

SciTech Connect

Two core holes have been completed on the flanks of Newberry Volcano, Oregon. Core hole Geo N-1 has a heat flow of 180 mW m/sup -2/, reflecting subsurface temperatures, sufficient for commerical exploitation of geothermally generated electricity. GEO N-3, which has a heat flow of 86 mW m/sup -2/, is less encouraging. We emphasize the ''rain curtain'' effect with the hope that a detailed discussion of this phenomenon at two distinct localities will lead to a better understanding of the physical processes in operation. Cole hole GEO N-1 was cored to a depth of 1387 m at a site located 9.3 km south of the center of the volcano. Core hole GEO N-3 was cored to a depth of 1220 m at a site located 12.6 km north of the center of the volcano. Both core holes penetrated interbedded pyroclastic lava flows and lithic tuffs ranging in composition from basalt to rhyolite, basaltic andesite being the most common rock type. Potassium-argon age dates range up to 2 Ma. Caving and sloughing were encountered in both core holes at depths near the regional water table. Both core holes penetrate three distinct thermal regimes. The uppermost regime is isothemal at mean air temperature down to about 900-1000 m (the rain curtain).

Swanberg, C.A.; Walkey, W.C.; Combs, J.

1988-09-10T23:59:59.000Z

318

Drillstring vibrations create crooked holes  

SciTech Connect

Boreholes in hard formations sometimes deviate when the drillstring runs rough or the kelly bounces severely. This article explains how drillstring vibrations produce crooked holes in hard formations. It shows how to reduce dog-leg severity through vibration control. Dog-legs are known to produce cyclic bending-type fatigue loads in drill pipe and collars. Longitudinal and torsional vibrational stresses are additive to rotational bending and further reduce the life of drillstring tubulars. Vibration-induced dog-legs are therefore more damaging to drillstrings than other dog-leg producing mechanisms because total cyclic fatigue loading is the combined effect of bending stress reversal due to rotation plus vibrational stress variations. The vibration-induced dog-leg concept is based on overall vibration response of drillstrings, resultant dynamic displacements of roller cone drill bits, and corresponding dynamic forces between bit and formation. The concept explains how dynamic forces generated by roller cone rock bits might produce helical bore holes in hard homogeneous formations. Dog-legs in hard formations may be due in part to drillstring vibrations. The wellbore deviation concept relates only to roller cone rock bits and is based on dynamically reorienting three-lobed formation pattern hammered out by bottomhole assembly resonance. Analytical studies are needed to determine the effect of bit force impact point location on chip formation and rock removal. Field studies of various bottom hole assemblies operating at critical rotary speeds coupled with directional surveys are needed to test the validity of this theory.

Dareing, D.W.

1984-01-01T23:59:59.000Z

319

Black Hole Evaporation as a Nonequilibrium Process  

E-Print Network (OSTI)

When a black hole evaporates, there arises a net energy flow from the black hole into its outside environment due to the Hawking radiation and the energy accretion onto black hole. Exactly speaking, due to the net energy flow, the black hole evaporation is a nonequilibrium process. To study details of evaporation process, nonequilibrium effects of the net energy flow should be taken into account. In this article we simplify the situation so that the Hawking radiation consists of non-self-interacting massless matter fields and also the energy accretion onto the black hole consists of the same fields. Then we find that the nonequilibrium nature of black hole evaporation is described by a nonequilibrium state of that field, and we formulate nonequilibrium thermodynamics of non-self-interacting massless fields. By applying it to black hole evaporation, followings are shown: (1) Nonequilibrium effects of the energy flow tends to accelerate the black hole evaporation, and, consequently, a specific nonequilibrium phenomenon of semi-classical black hole evaporation is suggested. Furthermore a suggestion about the end state of quantum size black hole evaporation is proposed in the context of information loss paradox. (2) Negative heat capacity of black hole is the physical essence of the generalized second law of black hole thermodynamics, and self-entropy production inside the matter around black hole is not necessary to ensure the generalized second law. Furthermore a lower bound for total entropy at the end of black hole evaporation is given. A relation of the lower bound with the so-called covariant entropy bound conjecture is interesting but left as an open issue.

Hiromi Saida

2008-11-11T23:59:59.000Z

320

Quasinormal Modes of Charged Fermions and Phase Transition of Black Holes  

E-Print Network (OSTI)

We study the quasinormal modes of massless charged fermions in a Reissner-Nordstrom-anti-de Sitter black hole spacetime. In the probe limit, we find that the imaginary part of quasinormal frequency will become positive when the temperature of the black hole is below a critical value. This indicates an instability of the black hole occurs and a phase transition happens. In the AdS/CFT correspondence, this transition can be viewed as a superconducting phase transition and the bulk fermion is regarded as the order parameter. When the coupling of the fermions and the background electric field becomes stronger, the critical temperature of the phase transition becomes higher. If the interaction between the fermion and the electric field can be ignored, namely in the case of a neutral fermion, the imaginary part of the quasinormal modes is always negative, which indicates that the black hole is stable and no phase transition occurs.

Rong-Gen Cai; Zhang-Yu Nie; Bin Wang; Hai-Qing Zhang

2010-05-07T23:59:59.000Z

Note: This page contains sample records for the topic "temperature gradient holes" 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

Quantization of the black hole area as quantization of the angular momentum component  

E-Print Network (OSTI)

In transforming from Schwarzschild to Euclidean Rindler coordinates the Schwarzschild time transforms to a periodic angle. As is well-known, this allows one to introduce the Hawking temperature and is an origin of black hole thermodynamics. On the other hand, according to quantum mechanics this angle is conjugate to the $z$ component of the angular momentum. From the commutation relation and quantization condition for the angular momentum component it is found that the area of the horizon of a Schwarzschild black hole is quantized with the quantum $\\Delta A = 8\\pi l_P^{2}$. It is shown that this conclusion is also valid for a generic Kerr-Newman black hole.

Kostyantyn Ropotenko

2009-06-10T23:59:59.000Z

322

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

DOE Green Energy (OSTI)

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

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

1983-12-01T23:59:59.000Z

323

Microscopic quantum structure of black hole and vacuum versus quantum statistical origin of gravity  

E-Print Network (OSTI)

The Planckon densely piled model of vacuum is proposed. Based on it, the microscopic quantum structure of Schwarzschild black hole and quantum statistical origin of its gravity are studied. It is shown that thermodynamic temperature equilibrium and mechanical acceleration balance make the space-time of the black hole horizon singular and Casimir effect works inside the horizon. This effect makes the inside vacuum have less zero fluctuation energy than the outside vacuum, and a temperature difference as well as gravity as thermal pressure are created. A dual relation between inside and outside regions of the black hole is found. By the dual relation, an attractor behaviour of the horizon surface is unveiled. Outside horizon, there exist thermodynamic non-equilibrium and mechanical non-balance which lead to outward centrifugal energy flow and inward gravitation energy flow, their compensation establishes local equilibrium. The lost vacuum energy in negative gravitation potential regions has been removed to the black hole surface to form a spherical Planckon shell with the thickness of Planckon diameter. All the particles absorbed by the black hole have fallen down to the horizon and converted into spin 1/2 radiation quanta made of standing waves on the horizon sphere with the mean energy related to Hawking-Unruh temperature, thermodynamic equilibrium and mechanical balance keep them stable and be tightly bound in the horizon. The gravitation mass 2M and physical mass $M$ of the black hole are calculated. The entropy of the black hole, calculated from the microscopic state number of the many-body system of radiation fermion quanta, is well consistent with Hawking. A radical modification of the temperature law of the black hole is made. The accelerating expansion of the universe yields the expansion cosmon and its energy density agrees with dark energy density.

Shun-Jin Wang

2012-12-24T23:59:59.000Z

324

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

325

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...

326

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

327

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

328

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

329

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

DOE Green Energy (OSTI)

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

Icerman, L.; Lohse, R.L.

1983-04-01T23:59:59.000Z

330

Stability of Asymptotically Schroedinger RN Black Hole and Superconductivity  

E-Print Network (OSTI)

We perform a perturbative (near-critical) analysis of the stability of an asymptotically Schroedinger Reissner-Nordstrom black hole with respect to generation of charged scalar hair. We find that apart from the expected instability at low temperatures typical of holographic models of superconductivity, in the presence of certain operators a similar instability appears as well at high temperatures. We propose that the reason for such a phase diagram could be due to peculiar features of the dual gauge theory or the failure of the model to provide a consistent holographic dual of a non-relativistic superconductor.

Stefano Cremonesi; Dmitry Melnikov; Yaron Oz

2009-11-19T23:59:59.000Z

331

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

332

Black Hole Information as Topological Qubits  

E-Print Network (OSTI)

The principle of balanced holography, introduced in [1], posits that black hole information is stored in non-local correlations between the interior and exterior. Based on this concept, we propose that black hole information decomposes into elementary units in the form of topological qubits, and is protected from local sources of decoherence. The topological protection mechanism ensures that the horizon of an evaporating black hole stays young and smooth.

Erik Verlinde; Herman Verlinde

2013-06-03T23:59:59.000Z

333

Black Hole Information as Topological Qubits  

E-Print Network (OSTI)

The principle of balanced holography, introduced in [1], posits that black hole information is stored in non-local correlations between the interior and exterior. Based on this concept, we propose that black hole information decomposes into elementary units in the form of topological qubits, and is protected from local sources of decoherence. The topological protection mechanism ensures that the horizon of an evaporating black hole stays young and smooth.

Verlinde, Erik

2013-01-01T23:59:59.000Z

334

Rotating Einstein-Yang-Mills Black Holes  

E-Print Network (OSTI)

We construct rotating hairy black holes in SU(2) Einstein-Yang-Mills theory. These stationary axially symmetric black holes are asymptotically flat. They possess non-trivial non-Abelian gauge fields outside their regular event horizon, and they carry non-Abelian electric charge. In the limit of vanishing angular momentum, they emerge from the neutral static spherically symmetric Einstein-Yang-Mills black holes, labelled by the node number of the gauge field function. With increasing angular momentum and mass, the non-Abelian electric charge of the solutions increases, but remains finite. The asymptotic expansion for these black hole solutions includes non-integer powers of the radial variable.

B. Kleihaus; J. Kunz; F. Navarro-Lerida

2002-07-10T23:59:59.000Z

335

Quantum Black Holes As Elementary Particles  

E-Print Network (OSTI)

Are black holes elementary particles? Are they fermions or bosons? We investigate the remarkable possibility that quantum black holes are the smallest and heaviest elementary particles. We are able to construct various fundamental quantum black holes: the spin-0, spin-1/2, spin-1, and the Planckcharge cases, using the results in general relativity. Quantum black holes in the neighborhood of the Galaxy could resolve the paradox posed by the Greisen-Zatsepin-Kuzmin limit on the energy of cosmic rays from distant sources. They could also play a role as dark matter in cosmology.

Yuan K. Ha

2008-01-01T23:59:59.000Z

336

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

337

Primordial Black Holes - Recent Developments  

E-Print Network (OSTI)

Recent developments in the study of primordial black holes (PBHs) will be reviewed, with particular emphasis on their formation and evaporation. PBHs could provide a unique probe of the early Universe, gravitational collapse, high energy physics and quantum gravity. Indeed their study may place interesting constraints on the physics relevant to these areas even if they never formed. In the "early Universe" context, particularly useful constraints can be placed on inflationary scenarios, especially if evaporating PBHs leave stable Planck-mass relicts. In the "gravitational collapse" context, the existence of PBHs could provide a unique test of the sort of critical phenomena discovered in recent numerical calculations. In the "high energy physics" context, information may come from gamma-ray bursts (if a subset of these are generated by PBH explosions) or from cosmic rays (if some of these derive from evaporating PBHs). In the "quantum gravity" context, the formation and evaporation of small black holes could lead to observable signatures in cosmic ray events and accelerator experiments, providing there are extra dimensions and providing the quantum gravity scale is around a TeV.

B. J. Carr

2005-04-01T23:59:59.000Z

338

NIST/Industry Developed Temperature Tracking Device for ...  

Science Conference Proceedings (OSTI)

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

2011-06-07T23:59:59.000Z

339

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

Open Energy Info (EERE)

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

340

The Generalized Uncertainty Principle and Black Hole Remnants  

DOE Green Energy (OSTI)

In the current standard viewpoint small black holes are believed to emit black body radiation at the Hawking temperature, at least until they approach Planck size, after which their fate is open to conjecture. A cogent argument against the existence of remnants is that, since no evident quantum number prevents it, black holes should radiate completely away to photons and other ordinary stable particles and vacuum, like any unstable quantum system. Here we argue the contrary, that the generalized uncertainty principle may prevent their total evaporation in exactly the same way that the uncertainty principle prevents the hydrogen atom from total collapse: the collapse is prevented, not by symmetry, but by dynamics, as a minimum size and mass are approached.

Chen, Pisin

2001-06-01T23:59:59.000Z

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


341

Black hole discharge in massive electrodynamics and black hole disappearance in massive gravity  

E-Print Network (OSTI)

We define and calculate the "discharge mode" for a Schwarzschild black hole in massive electrodynamics. For small photon mass, the discharge mode describes the decay of the electric field of a charged star collapsing into a black hole. We argue that a similar "discharge of mass" occurs in massive gravity and leads to a strange process of black hole disappearance.

Mirbabayi, Mehrdad

2013-01-01T23:59:59.000Z

342

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

343

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

344

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

345

CHARYBDIS: A Black hole event generator.  

E-Print Network (OSTI)

]. [15] D. M. Eardley and S. B. Giddings, Classical Black Hole Production in High-Energy Collisions, [gr-qc/0201034]. [16] S. W. Hawking, Particle Creation by Black Holes, Comm. Math. Phys. 43 (1975) 199. [17] R. Emperan, G. T. Horowitz and R. C. Myers...

Harris, Chris M; Richardson, P; Webber, Bryan R

346

Strings, black holes, and quantum information  

SciTech Connect

We find multiple relations between extremal black holes in string theory and 2- and 3-qubit systems in quantum information theory. We show that the entropy of the axion-dilaton extremal black hole is related to the concurrence of a 2-qubit state, whereas the entropy of the STU black holes, Bogomol'nyi-Prasad-Sommerfield (BPS) as well as non-BPS, is related to the 3-tangle of a 3-qubit state. We relate the 3-qubit states with the string theory states with some number of D-branes. We identify a set of large black holes with the maximally entangled Greenberger, Horne, Zeilinger (GHZ) class of states and small black holes with separable, bipartite, and W states. We sort out the relation between 3-qubit states, twistors, octonions, and black holes. We give a simple expression for the entropy and the area of stretched horizon of small black holes in terms of a norm and 2-tangles of a 3-qubit system. Finally, we show that the most general expression for the black hole and black ring entropy in N=8 supergravity/M theory, which is given by the famous quartic Cartan E{sub 7(7)} invariant, can be reduced to Cayley's hyperdeterminant describing the 3-tangle of a 3-qubit state.

Kallosh, Renata; Linde, Andrei [Department of Physics, Stanford University, Stanford, California 94305 (United States)

2006-05-15T23:59:59.000Z

347

Plenary lecture 4: black holes nonholonomic thermodynamics  

Science Conference Proceedings (OSTI)

This Lecture presents the geometry and the interaction of nonholonomic black hole systems using a specialized MAPLE soft for computing. Our point of view is strongly connected to the possibility of describing a nonholonomic black hole system via a Gibbs-Pfaff ...

Constantin Udriste

2010-10-01T23:59:59.000Z

348

Black Hole Spectrum: Continuous or Discrete?  

E-Print Network (OSTI)

We formulate a qualitative argument, based on Heisenberg's uncertainty principle, to support the claim that when the effects of matter fields are assumed to overshadow the effects of quantum mechanics of spacetime, the discrete spectrum of black hole radiation, as such as predicted by Bekenstein's proposal for a discrete black hole area spectrum, reduces to Hawking's black-body spectrum.

Jarmo Makela

1996-08-30T23:59:59.000Z

349

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

350

Slim holes haul in savings  

SciTech Connect

This article reports that during 1986 BP Exploration Company Ltd. successfully drilled six UK land wells with a Microdrill MD-3 ultra-slimhole drilling rig. The objective of the program was to evaluate the slimhole drilling technique, from both a technical and cost-effective viewpoint. Earlier studies indicated up to 30 percent savings in well costs compared to conventionally drilled UK land wells. The technology of drilling slim holes with small rigs is not new. For many years the mineral exploration industry has used small drilling and coring rigs. However, these rigs are not normally equipped with pressure control equipment, oilfield mud and cementing systems or the ability to run complex logs or production test. More recently, the oil industry has made efforts to adapt these rigs to slimhole oil and gas exploration, notably in Australia and Canada. The Microdrill MD-3 rig is a product of this evolution.

Floyd, K.

1987-07-01T23:59:59.000Z

351

How to interpret black hole entropy?  

E-Print Network (OSTI)

We consider a possibility that the entropy of a Schwarzschild black hole has two different interpretations: The black hole entropy can be understood either as an outcome of a huge degeneracy in the mass eigenstates of the hole, or as a consequence of the fact that the interior region of black hole spacetime is separated from the exterior region by a horizon. In the latter case, no degeneracy in the mass eigenstates needs to be assumed. Our investigation is based on calculations performed with Lorentzian partition functions obtained for a whole maximally extended Schwarzschild spacetime, and for its right-hand-side exterior region. To check the correctness of our analysis we reproduce, in the leading order approximation, the Bekenstein--Hawking entropy of the Schwarzschild black hole.

J. Makela; P. Repo

1998-12-21T23:59:59.000Z

352

Single-Holed Regions: Their Relations and Inferences  

Science Conference Proceedings (OSTI)

The discontinuities in boundaries and exteriors that regions with holes expose offer opportunities for inferences that are impossible for regions without holes. A systematic study of the binary relations between single-holed regions shows not only an ...

Maria Vasardani; Max J. Egenhofer

2008-09-01T23:59:59.000Z

353

Probing Core-Hole Localization in Molecular Nitrogen  

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

Probing Core-Hole Localization in Molecular Nitrogen Probing Core-Hole Localization in Molecular Nitrogen Print Wednesday, 25 February 2009 00:00 The behavior of the core hole...

354

Black holes in supergravity: the non-BPS branch  

E-Print Network (OSTI)

The Seed Solution: Non-BPS Black Holes with 5nd that the mass of the non-BPS black hole remains that of aconstruction of regular black hole solutions in supergravity

Gimon, Eric G.

2008-01-01T23:59:59.000Z

355

Black Holes at the LHC: Progress since 2002  

E-Print Network (OSTI)

We review the recent noticeable progresses in black hole physics focusing on the up-coming super-collider, the LHC. We discuss the classical formation of black holes by particle collision, the greybody factors for higher dimensional rotating black holes, the deep implications of black hole physics to the `energy-distance' relation, the security issues of the LHC associated with black hole formation and the newly developed Monte-Carlo generators for black hole events.

Seong Chan Park

2008-09-15T23:59:59.000Z

356

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

357

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

358

T-623: HP Business Availability Center Input Validation Hole...  

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

3: HP Business Availability Center Input Validation Hole Permits Cross-Site Scripting Attacks T-623: HP Business Availability Center Input Validation Hole Permits Cross-Site...

359

Probing Core-Hole Localization in Molecular Nitrogen  

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

Probing Core-Hole Localization in Molecular Nitrogen Print The behavior of the core hole created in molecular x-ray photoemission experiments has provided molecular scientists with...

360

Slim Holes At Maui Area (DOE GTP) | Open Energy Information  

Open Energy Info (EERE)

Slim Holes At Maui Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Maui Area (DOE GTP) Exploration Activity Details...

Note: This page contains sample records for the topic "temperature gradient holes" 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

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

362

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

Science Conference Proceedings (OSTI)

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

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

1981-01-01T23:59:59.000Z

363

The fuzzball proposal for black holes  

E-Print Network (OSTI)

The fuzzball proposal states that associated with a black hole of entropy S there are exp S horizon-free non-singular solutions that asymptotically look like the black hole but generically differ from the black hole up to the horizon scale. These solutions, the fuzzballs, are considered to be the black hole microstates while the original black hole represents the average description of the system. The purpose of this report is to review current evidence for the fuzzball proposal, emphasizing the use of AdS/CFT methods in developing and testing the proposal. In particular, we discuss the status of the proposal for 2 and 3 charge black holes in the D1-D5 system, presenting new derivations and streamlining the discussion of their properties. Results to date support the fuzzball proposal but further progress is likely to require going beyond the supergravity approximation and sharpening the definition of a "stringy fuzzball". We outline how the fuzzball proposal could resolve longstanding issues in black hole physics, such as Hawking radiation and information loss. Our emphasis throughout is on connecting different developments and identifying open problems and directions for future research.

Kostas Skenderis; Marika Taylor

2008-04-03T23:59:59.000Z

364

Modeling Flows Around Merging Black Hole Binaries  

E-Print Network (OSTI)

Coalescing massive black hole binaries are produced by the mergers of galaxies. The final stages of the black hole coalescence produce strong gravitational radiation that can be detected by the space-borne LISA. In cases where the black hole merger takes place in the presence of gas and magnetic fields, various types of electromagnetic signals may also be produced. Modeling such electromagnetic counterparts of the final merger requires evolving the behavior of both gas and fields in the strong-field regions around the black holes. We have taken a step towards solving this problem by mapping the flow of pressureless matter in the dynamic, 3-D general relativistic spacetime around the merging black holes. We find qualitative differences in collision and outflow speeds, including a signature of the merger when the net angular momentum of the matter is low, between the results from single and binary black holes, and between nonrotating and rotating holes in binaries. If future magnetohydrodynamic results confirm these differences, it may allow assessment of the properties of the binaries as well as yielding an identifiable electromagnetic counterpart to the attendant gravitational wave signal.

James R. van Meter; John H. Wise; M. Coleman Miller; Christopher S. Reynolds; Joan M. Centrella; John G. Baker; William D. Boggs; Bernard J. Kelly; Sean T. McWilliams

2009-07-31T23:59:59.000Z

365

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

366

Schwarzschild-de Sitter black hole from entropic viewpoint  

E-Print Network (OSTI)

In a Schwarzschild-de Sitter space, we consider an equipotential surface which consists of two holographic screens. Adapting the Bousso-Hawking's reference point of vanishing force, we divide the space into two regions, which are from the reference point to each holographic screen. These two regions can be treated as independent thermodynamical systems, because the Bousso-Hawking reference point with zero temperature behaves like a thermally insulating wall. The entropy obtained in this way agrees with the conventional results; i) when the holographic screens lie at the black hole and cosmological horizons, ii) in the Nariai limit.

Ee Chang-Young; Myungseok Eune; Kyoungtae Kimm; Daeho Lee

2010-11-17T23:59:59.000Z

367

Slim Holes At Steamboat Springs Area (Warpinski, Et Al., 2002) | Open  

Open Energy Info (EERE)

2) 2) Exploration Activity Details Location Steamboat Springs Area Exploration Technique Slim Holes Activity Date Usefulness useful DOE-funding Unknown Notes Stratigraphic slim hole 24-33 was drilled in a lease area south of current production during March 2001. The well was continuously cored from 235 m to the total depth of 610 m. Several fracture zones were encountered with noticeably large fracture apertures and the maximum recorded temperature was comparable to nearby productive wells. A second well, slim hole 12-33, was drilled to a total depth of 297 m during April 2001. Continuous core was taken from 152 m to total depth. Numerous open fractures were also observed in this well and the maximum recorded temperature was similar to the 24-33 well. References

368

Core Holes At Steamboat Springs Area (Warpinski, Et Al., 2002) | Open  

Open Energy Info (EERE)

2) 2) Exploration Activity Details Location Steamboat Springs Area Exploration Technique Core Holes Activity Date Usefulness not indicated DOE-funding Unknown Notes Stratigraphic slim hole 24-33 was drilled in a lease area south of current production during March 2001. The well was continuously cored from 235 m to the total depth of 610 m. Several fracture zones were encountered with noticeably large fracture apertures and the maximum recorded temperature was comparable to nearby productive wells. A second well, slim hole 12-33, was drilled to a total depth of 297 m during April 2001. Continuous core was taken from 152 m to total depth. Numerous open fractures were also observed in this well and the maximum recorded temperature was similar to the 24-33 well.

369

High Temperature ESP Monitoring  

SciTech Connect

The objective of the High Temperature ESP Monitoring project was to develop a downhole monitoring system to be used in wells with bottom hole well temperatures up to 300C for measuring motor temperature, formation pressure, and formation temperature. These measurements are used to monitor the health of the ESP motor, to track the downhole operating conditions, and to optimize the pump operation. A 220 C based High Temperature ESP Monitoring system was commercially released for sale with Schlumberger ESP motors April of 2011 and a 250 C system with will be commercially released at the end of Q2 2011. The measurement system is now fully qualified, except for the sensor, at 300 C.

Jack Booker; Brindesh Dhruva

2011-06-20T23:59:59.000Z

370

Some aspects of virtual black holes  

SciTech Connect

We first consider consistently third-quantize modified gravity. We then analyze certain aspects of virtual black holes in this third-quantized modified gravity. We see how a statistical mechanical origin for the Bekenstein-Hawking entropy naturally arises in this model. Furthermore, the area and hence the entropy of a real macroscopic black hole is quantized in this model. Virtual black holes cause a loss of quantum coherence, which gives an intrinsic entropy to all physical systems that can be used to define a direction of time and hence provide a solution to the problem of time.

Faizal, M., E-mail: faizal.mir@durham.ac.uk [University of Durham, Department of Mathematics (United Kingdom)

2012-03-15T23:59:59.000Z

371

Slim Holes for Small Power Plants  

DOE Green Energy (OSTI)

Geothermal research study at Sandia National Laboratories has conducted a program in slimhole drilling research since 1992. Although our original interest focused on slim holes as an exploration method, it has also become apparent that they have substantial potential for driving small-scale, off-grid power plants. This paper summarizes Sandia's slim-hole research program, describes technology used in a ''typical'' slimhole drilling project, presents an evaluation of using slim holes for small power plants, and lists some of the research topics that deserve further investigation.

Finger, John T.

1999-08-06T23:59:59.000Z

372

Some remarks on black hole thermodynamics  

E-Print Network (OSTI)

Two thermodynamic "paradoxes" of black hole physics are re-examined. The first is that there is a thermal instability involving two coupled blackbody cavities containing two black holes, and second is that a classical black hole can swallow up entropy in the form of ambient blackbody photons without increasing its mass. The resolution of the second paradox by Bekenstein and by Hawking is re-visited. The link between Hawking radiation and Wigner's superluminal tunneling time is discussed using two equivalent Feynman diagrams, and Feynman's re-interpretation principle.

R. Y. Chiao

2010-12-27T23:59:59.000Z

373

Slim Holes for Small Power Plants  

SciTech Connect

Geothermal research study at Sandia National Laboratories has conducted a program in slimhole drilling research since 1992. Although our original interest focused on slim holes as an exploration method, it has also become apparent that they have substantial potential for driving small-scale, off-grid power plants. This paper summarizes Sandia's slim-hole research program, describes technology used in a ''typical'' slimhole drilling project, presents an evaluation of using slim holes for small power plants, and lists some of the research topics that deserve further investigation.

Finger, John T.

1999-08-06T23:59:59.000Z

374

What Black Holes Can Teach Us  

E-Print Network (OSTI)

Black holes merge together different field of physics. From General Relativity over thermodynamics and quantum field theory, they do now also reach into the regime of particle and collider physics. In the presence of additional compactified dimensions, it would be possible to produce tiny black holes at future colliders. We would be able to test Planck scale physics and the onset of quantum gravity. The understanding of black hole physics is a key knowledge to the phenomenology of these new effects beyond the Standard Model. This article gives a brief introduction into the main issues and is addressed to a non-expert audience.

Sabine Hossenfelder

2004-12-17T23:59:59.000Z

375

Finite Temperature Aging Holography  

E-Print Network (OSTI)

We construct the gravity background which describes the dual field theory with aging invariance. We choose the decay modes of the bulk scalar field in the internal spectator direction to obtain the dissipative behavior of the boundary correlation functions of the dual scalar fields. In particular, the two-time correlation function at zero temperature has the characteristic features of the aging system: power law decay, broken time translation and dynamical scaling. We also construct the black hole backgrounds with asymptotic aging invariance. We extensively study characteristic behavior of the finite temperature two-point correlation function via analytic and numerical methods.

Seungjoon Hyun; Jaehoon Jeong; Bom Soo Kim

2011-08-29T23:59:59.000Z

376

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

377

Holes and Entrainment in Stratocumulus  

Science Conference Proceedings (OSTI)

Aircraft flights through stratocumulus clouds (Sc) during the Dynamics and Chemistry of Marine Stratocumulus II (DYCOMS-II) study off the California coast found narrow in-cloud regions with less liquid water content (LWC) and cooler temperatures ...

H. Gerber; G. Frick; S. P. Malinowski; J-L. Brenguier; F. Burnet

2005-02-01T23:59:59.000Z

378

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

379

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

380

Energy of 4-Dimensional Black Hole, etc  

E-Print Network (OSTI)

In this letter I suggest possible redefinition of mass density, not depending on speed of the mass element, which leads to a more simple stress-energy for an object. I calculate energy of black hole.

Dmitriy Palatnik

2007-04-10T23:59:59.000Z

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


381

A Universal Intrinsic Scale of Hole Concentration for High-Tc Cuprates  

E-Print Network (OSTI)

We have measured thermoelectric power (TEP) as a function of hole concentration per CuO2 layer, Ppl, in Y1-xCaxBa2Cu3O6 (Ppl = x/2) with no oxygen in the Cu-O chain layer. The room-temperature TEP as a function of Ppl, S290(Ppl), of Y1-xCaxBa2Cu3O6 behaves identically to that of La2-zSrzCuO4 (Ppl = z). We argue that S290(Ppl) represents a measure of the intrinsic equilibrium electronic states of doped holes and, therefore, can be used as a common scale for the carrier concentrations of layered cuprates. We shows that the Ppl determined by this new universal scale is consistent with both hole concentration microscopically determined by NQR and the hole concentration macroscopically determined by the Cu valency. We find two characteristic scaling temperatures, TS* and TS2*, in the TEP vs. temperature curves that change systematically with doping. Based on the universal scale, we uncover a universal phase diagram in which almost all the experimentally determined pseudogap temperatures as a function of Ppl fall on two common curves; upper pseudogap temperature defined by the TS* versus Ppl curve and lower pseudogap temperature defined by the TS2* versus Ppl curve. We find that while pseudogaps are intrinsic properties of doped holes of a single CuO2 layer for all high-Tc cuprates, Tc depends on the number of layers, therefore the inter-layer coupling, in each individual system.

T. Honma; P. H. Hor; H. H. Hsieh; M. Tanimoto

2003-09-25T23:59:59.000Z

382

Jordan Algebras and Extremal Black Holes  

E-Print Network (OSTI)

We review various properties of the exceptional Euclidean Jordan algebra of degree three. Euclidean Jordan algebras of degree three and their corresponding Freudenthal triple systems were recently shown to be intimately related to extremal black holes in N=2, d=4 homogeneous supergravities. Using a novel type of eigenvalue problem with eigenmatrix solutions, we elucidate the rich matrix geometry underlying the exceptional N=2, d=4 homogeneous supergravity and explore the relations to extremal black holes.

Michael Rios

2007-03-27T23:59:59.000Z

383

Information Loss in Black Hole Evaporation  

E-Print Network (OSTI)

Parikh-Wilczek tunnelling framework is investigated again. We argue that Parikh-Wilczek's treatment, which satisfies the first law of black hole thermodynamics and consists with an underlying unitary theory, is only suitable for a reversible process. Because of the negative heat capacity, an evaporating black hole is a highly unstable system. That is, the factual emission process is irreversible, the unitary theory will not be satisfied and the information loss is possible.

Jingyi Zhang; Yapeng Hu; Zheng Zhao

2005-12-11T23:59:59.000Z

384

Direct Evidence of Sheets in the Atmospheric Temperature Field  

Science Conference Proceedings (OSTI)

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

Francis Dalaudier; Claude Sidi; Michel Crochet; Jean Vernin

1994-01-01T23:59:59.000Z

385

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

386

Superconducting Cosmic Strings that Connected a Charged Black Hole and Considered as Hair of Black Hole  

E-Print Network (OSTI)

This paper describes that the superconducting cosmic strings can be connected to an electrically charged black hole, and can be considerd as the hair of black hole. What the no-hair theorems show is that a large amount of information is lost when a body collapses to form a black hole. In addition, the no-hair theorem has not been proved for the Yang-Mills field. This paper proves and claims that the superconducting cosmic strings can be connected to an electrically charged hole when the current inside these strings and black holes approaches the critical value. Because, this state is the final state of the gravitational collapse, and the event horizon would be destroyed in this state. Therefore, these strings should be considered as hair of the charged black holes, and may be titled as BHCS (Black Hole Connected Strings). This means that at least the charged black holes have the hair. Thus, the no-hair theorem is not applicable for the charged black holes in the state of the critical current.

Ali Riza Akcay

1999-09-23T23:59:59.000Z

387

Quantum corrections for a black hole in an asymptotically safe gravity with higher derivatives  

E-Print Network (OSTI)

By using the quantum tunneling approach over semiclassical approximations, we study the quantum corrections to the Hawking temperature, entropy and Bekenstein-Hawking entropy-area relation for a black hole in an asymptotically safe gravity with higher derivatives. The leading and non leading corrections to the area law are obtained.

Mubasher Jamil; Farhad Darabi

2011-10-29T23:59:59.000Z

388

Comparing relations with a multi-holed region  

Science Conference Proceedings (OSTI)

Relation models have treated multi-holed regions relations either the same as hole-free regions relations, loosing this way the peculiarities of the holed topology, or with methods dependent on the number of holes. This paper discusses a model of relations ...

Maria Vasardani; Max J. Egenhofer

2009-09-01T23:59:59.000Z

389

Black Hole Complementary Principle and The Noncommutative Membrane  

E-Print Network (OSTI)

In the spirit of Black Hole Complementary Principle, we have found the noncommutative membrane of Scharzchild Black Holes. In this paper we extend our results to Kerr Black Hole and see the same story. Also we make a conjecture that spacetimes is noncommutative on the stretched membrane of the more general Kerr-Newman Black Hole.

Zen Wei

2005-11-14T23:59:59.000Z

390

Solar Wind Forecasting with Coronal Holes  

E-Print Network (OSTI)

An empirical model for forecasting solar wind speed related geomagnetic events is presented here. The model is based on the estimated location and size of solar coronal holes. This method differs from models that are based on photospheric magnetograms (e.g., Wang-Sheeley model) to estimate the open field line configuration. Rather than requiring the use of a full magnetic synoptic map, the method presented here can be used to forecast solar wind velocities and magnetic polarity from a single coronal hole image, along with a single magnetic full-disk image. The coronal hole parameters used in this study are estimated with Kitt Peak Vacuum Telescope He I 1083 nm spectrograms and photospheric magnetograms. Solar wind and coronal hole data for the period between May 1992 and September 2003 are investigated. The new model is found to be accurate to within 10% of observed solar wind measurements for its best one-month periods, and it has a linear correlation coefficient of ~0.38 for the full 11 years studied. Using a single estimated coronal hole map, the model can forecast the Earth directed solar wind velocity up to 8.5 days in advance. In addition, this method can be used with any source of coronal hole area and location data.

S. Robbins; C. J. Henney; J. W. Harvey

2007-01-09T23:59:59.000Z

391

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

392

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

393

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

394

7Falling Into a Black Hole An object that falls into a black hole will cross the  

E-Print Network (OSTI)

7Falling Into a Black Hole An object that falls into a black hole will cross the Event Horizon. Astronomers have determined the mass of this companion to be 8.7 times the sun. As a black hole, its Event determined the mass of this companion to be 8.7 times the sun. As a black hole, its Event Horizon radius

395

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

396

Preliminary estimates of electrical generating capacity of slim holes--a theoretical approach  

SciTech Connect

The feasibility of using small geothermal generators (< 1 MWe) for off-grid electrical power in remote areas or for rural electrification in developing nations would be enhanced if drilling costs could be reduced. This paper examines the electrical generating capacity of fluids which can be produced from typical slim holes (six-inch diameter or less), both by binary techniques (with downhole pumps) and, for hotter reservoir fluids, by conventional spontaneous-discharge flash-steam methods. Depending mainly on reservoir temperature, electrical capacities from a few hundred kilowatts to over one megawatt per slim hole appear to be possible.

Pritchett, John W.

1995-01-26T23:59:59.000Z

397

Observational studies of stellar black hole binaries and ULXs  

E-Print Network (OSTI)

We outline a framework for understanding the X-ray spectra of high mass accretion rate stellar black holes based on X-ray data from RXTE and ASCA. Three spectral regimes can be separated out by the behaviour of the observed disk luminosity and temperature. The well established "standard regime" is seen when the disk dominates the spectrum, where only a small fraction of the luminosity is emitted in the power law tail. These spectra generally satisfy the standard relation expected for thermal emission from a constant area, namely that the disk bolometric luminosity, Ldisk, is proportional to its maximum temperature, Tin^4. However, at higher luminosities this starts to change to Tin^2. This "apparently standard regime" is still dominated by the disk emission, but this difference luminosity-temperature relation and subtle changes in spectral shape may show that another cooling process is required in addition to radiative cooling. At intermediate luminosities there is an anomalous regime (or weak very high state) where the disk temperature and luminosity are less clearly related. These spectra are characterized by the presence of a much stronger comptonized tail indicating high energy electrons. When observed disk emission is corrected for the the effects of comptonisation then these points lie back on the standard relation. The growth of this comptonising corona is also clearly linked to the quasi-periodic oscillations, as these are observed preferentially in the anomalous regime. This presented picture was found to explain the spectral behavior of both black hole binaries in our Galaxy and LMC. Spectral evolution of several bright ULXs observed with ASCA were also successfully explained in the same picture.

Aya Kubota; Kazuo Makishima

2005-07-12T23:59:59.000Z

398

Black Holes or Frozen Stars? A Viable Theory of Gravity without Black Holes  

E-Print Network (OSTI)

Do observations of black hole candidates rule out alternative theories of gravity without horizon formation? This depends on the existence, viability and reasonableness of alternative theories of gravity without black holes. Here a theory of gravity without black hole horizon formation is presented. The gravitational collapse stops shortly before horizon formation and leaves a stable frozen star. In the limit $\\Xi, \\Upsilon\\to 0$ the Einstein equations of GR are recovered, and the frozen stars become observationally indistinguishable from GR black holes. The theory therefore provides a counterexample to recent claims that observational evidence from black hole candidates "all but requires the existence of a horizon". The theory presented here shares its equations with RTG. Nonetheless, as is shown, there remain important conceptual and physical differences. In particular, some serious problems of RTG are not present in the theory proposed here. So it can be argued that the theory is a physically viable and conceptually sound alternative to GR.

I. Schmelzer

2010-03-07T23:59:59.000Z

399

Investigating Dark Energy with Black Hole Binaries  

E-Print Network (OSTI)

The accelerated expansion of the universe is ascribed to the existence of dark energy. Black holes accretion of dark energy induces a mass change proportional to the energy density and pressure of the background dark energy fluid. The time scale during which the mass of black holes changes considerably is too long relative to the age of the universe, thus beyond detection possibilities. We propose to take advantage of the modified black hole masses for exploring the equation of state $w[z]$ of dark energy, by investigating the evolution of supermassive black hole binaries on a dark energy background. Deriving the signatures of dark energy accretion on the evolution of binaries, we find that dark energy imprints on the emitted gravitational radiation and on the changes in the orbital radius of the binary can be within detection limits for certain supermassive black hole binaries. In this talk I describe how binaries can provide a useful tool in obtaining complementary information on the nature of dark energy, based on the work done with A.Kelleher.

Laura Mersini-Houghton; Adam Kelleher

2009-06-08T23:59:59.000Z

400

The Environmental Impact of Supermassive Black Holes  

E-Print Network (OSTI)

The supermassive black holes observed at the centers of almost all present-day galaxies, had a profound impact on their environment. I highlight the principle of self-regulation, by which supermassive black holes grow until they release sufficient energy to unbind the gas that feeds them from their host galaxy. This principle explains several observed facts, including the correlation between the mass of a central black hole and the depth of the gravitational potential well of its host galaxy, and the abundance and clustering properties of bright quasars in the redshift interval of z~2-6. At lower redshifts, quasars might have limited the maximum mass of galaxies through the suppression of cooling flows in X-ray clusters. The seeds of supermassive black holes were likely planted in dwarf galaxies at redshifts z>10, through the collapse of massive or supermassive stars. The minimum seed mass can be identified observationally through the detection of gravitational waves from black hole binaries by Advanced LIGO or LISA. Aside from shaping their host galaxies, quasar outflows filled the intergalactic medium with magnetic fields and heavy elements. Beyond the reach of these outflows, the brightest quasars at z>6 have ionized exceedingly large volumes of gas (tens of comoving Mpc) prior to global reionization, and must have suppressed the faint end of the galaxy luminosity function in these volumes before the same occurred through the rest of the universe.

Abraham Loeb

2004-08-10T23:59:59.000Z

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


401

Geology, drill holes, and geothermal energy potential of the basal Cambrian rock units of the Appalachian Basin of New York State  

DOE Green Energy (OSTI)

The published geologic and geophysical records plus data gathered from deep wells during hydrocarbon exploration were inventoried, discussed and summarized to evaluate hydro-geothermal energy potential in the western counties of New York, south of the 42/sup 0/ latitude. An assessment is provided of local geothermal energy potential based on these data. The assessed potential is a function of the geothermal gradient, the depth of porous Cambrian age sedimentary units and a variety of features thought to be related to deep fracturing and hence enhanced porosity and permeability. The completion history of a selected set of plugged and abandoned deep wells was examined to determine the feasibility and advisability of re-entering these holes for geothermal development. All wells showed extensive cement plugging and uncertain materials introduced for bridging. It was recommended that no attempt be made to re-enter these wells. The hydro-geothermal energy potential in Western New York State is largely comparable to that of other regions possessing porous/permeable units of sedimentary rock at sufficient depth to contain formation waters of useful temperatures (>140/sup 0/F). A comparison of geothermal reservoirs in New York to similar sites now under development in Canada and France has revealed that potential resources in New York State are slightly hotter, though somewhat thicker and less permeable with significantly higher proportions of dissolved constituents.

Pferd, J.W.

1981-06-01T23:59:59.000Z

402

Planning, drilling, logging, and testing of energy extraction hole EE-1, Phases I and II  

DOE Green Energy (OSTI)

Energy Extraction Hole No. 1 (EE-1) is the second deep hole drilled into the Precambrian-age granitic rocks of the Jemez Mountains of north-central New Mexico. EE-1 was drilled to intersect a hydraulic fracture extending outward from near the bottom of previously drilled hole GT-2, thus completing the underground circulation loop required for the hot dry rock geothermal energy extraction experiment. Directional drilling techniques were used to intersect the fracture zone. In addition, high-temperature instrumentation and equipment development, hydraulic fracturing experiments, pressure-flow testing of the fracture systems, and fracture mapping and borehole-ranging technique activities were conducted. The drilling, logging, and testing operations in EE-1 are described.

Pettitt, R.A.

1977-08-01T23:59:59.000Z

403

Slim Holes At Fort Bliss Area (Combs, Et Al., 1999) | Open Energy  

Open Energy Info (EERE)

Fort Bliss Area (Combs, Et Al., 1999) Fort Bliss Area (Combs, Et Al., 1999) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Fort Bliss Area (Combs, Et Al., 1999) Exploration Activity Details Location Fort Bliss Area Exploration Technique Slim Holes Activity Date Usefulness useful DOE-funding Unknown Notes When the U. S. Army was in the planning stages for a geothermal exploration program at Ft. Bliss, they approached the Geothermal Research Department for input on the structure of this progrm, this consultation led to a Work-for-Others (WFO) contract from the Army to Sandia for assistance on the exploratory holes. That assistance included consultation and dmection of drilling operations, numerous temperature logs during and after drilling, and project documentation. This report comprises a summary of

404

Rotating black hole thermodynamics with a particle probe  

Science Conference Proceedings (OSTI)

The thermodynamics of Myers-Perry black holes in general dimensions are studied using a particle probe. When undergoing particle absorption, the changes of the entropy and irreducible mass are shown to be dependent on the particle radial momentum. The black hole thermodynamic behaviors are dependent on dimensionality for specific rotations. For a 4-dimensional Kerr black hole, its black hole properties are maintained for any particle absorption. 5-dimensional black holes can avoid a naked ring singularity by absorbing a particle in specific momenta ranges. Black holes over 6 dimensions become ultraspinning black holes through a specific form of particle absorption. The microscopical changes are interpreted in limited cases of Myers-Perry black holes using Kerr/CFT correspondence. We systematically describe the black hole properties changed by particle absorption in all dimensions.

Gwak, Bogeun; Lee, Bum-Hoon [Department of Physics and Center of Quantum Spacetime, Sogang University, Seoul 121-742 (Korea, Republic of)

2011-10-15T23:59:59.000Z

405

The Revival of White Holes as Small Bangs  

E-Print Network (OSTI)

Black holes are extremely dense and compact objects from which light cannot escape. There is an overall consensus that black holes exist and many astronomical objects are identified with black holes. White holes were understood as the exact time reversal of black holes, therefore they should continuously throw away material. It is accepted, however, that a persistent ejection of mass leads to gravitational pressure, the formation of a black hole and thus to the "death of while holes". So far, no astronomical source has been successfully tagged a white hole. The only known white hole is the Big Bang which was instantaneous rather than continuous or long-lasting. We thus suggest that the emergence of a white hole, which we name a 'Small Bang', is spontaneous - all the matter is ejected at a single pulse. Unlike black holes, white holes cannot be continuously observed rather their effect can only be detected around the event itself. Gamma ray bursts are the most energetic explosions in the universe. Long gamma-ray bursts were connected with supernova eruptions. There is a new group of gamma-ray bursts, which are relatively close to Earth, but surprisingly lack any supernova emission. We propose identifying these bursts with white holes. White holes seem like the best explanation of gamma-ray bursts that appear in voids. We also predict the detection of rare gigantic gamma-ray bursts with energies much higher than typically observed.

Alon Retter; Shlomo Heller

2011-05-13T23:59:59.000Z

406

Temperatures and heat flow in INEL-GT1 and WO-2 boreholes, Snake River Plain, Idaho  

DOE Green Energy (OSTI)

The researchers have logged temperatures in the deep geothermal test at the INEL test site on the eastern Snake River Plains in Idaho (INEL-GT1) three times over a period of 8 years. The first logging was on 8/20/82 when they reached a depth of 2100 m. They were unable to get past the casing shoe at that depth. In 1983 (7/25/83) they relogged the well with a centralizer on the temperature tool and got past the casing hanger to the end of their cable at 2870 m. In both cases the logs were made at a 0.5 m recording interval. In 1990 the researchers relogged the well for a third time and for the first time reached the bottom of the well at 3130 m. In this log the temperatures were measured at 0.2 m intervals. The temperature-depth plots for the last two logs are compared and the gradient logs for the three logs are compared. The differences in temperature are almost too small to see on the plot. The only significant differences are in the depth interval 700 to 1850 m, a section of the hole with a number of fluid disturbances.

Blackwell, D.D. [Southern Methodist Univ., Dallas, TX (United States). Dept. of Geological Sciences

1990-11-01T23:59:59.000Z

407

Propagating MHD waves in coronal holes  

E-Print Network (OSTI)

Coronal holes are the coolest and darkest regions of the solar atmosphere, as observed both on the solar disk and above the solar limb. Coronal holes are associated with rapidly expanding open magnetic fields and the acceleration of the high-speed solar wind. During the years of the solar minima, coronal holes are generally confined to the Sun's polar regions, while at solar maxima they can also be found at lower latitudes. Waves, observed via remote sensing and detected in-situ in the wind streams, are most likely responsible for the wind and several theoretical models describe the role of MHD waves in the acceleration of the fast solar wind. This paper reviews the observational evidences of detection of propa- gating waves in these regions. The characteristics of the waves, like periodicities, amplitude, speed provide input parameters and also act as constraints on theoretical models of coronal heating and solar wind acceleration.

Banerjee, D; Teriaca, L

2010-01-01T23:59:59.000Z

408

Injection of Electrons and Holes into Nanostructures  

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

Injection of Electrons and Holes into Nanostructures Injection of Electrons and Holes into Nanostructures This program targets fundamental understanding of nanoscale charge transfer processes. The proposed work draws on the strengths of the Brookhaven Chemistry Department in the areas of electron transfer experiment and theory, and extends the area of inquiry to nanoscale processes. Electron/hole injection into a wire, a nanocrystal, a nanotube or other nanostructure in solution may be brought about by light absorption, by an electron pulse (pulse radiolysis, LEAF), by a chemical reagent, or through an electrode. These processes are being studied by transient methods by following conductivity, current, but most generally, spectroscopic changes in the solutions to determine the dynamics of charge injection. The observed transient spectra can also provide values for electron-transfer coupling elements and energetics. Theoretical/computational studies can help in materials design and in the interpretation of the experimental results. The experimental systems being examined include molecular wires and metal nanoclusters.

409

Black Holes in Three Dimensional Topological Gravity  

E-Print Network (OSTI)

We investigate the black hole solution to (2+1)-dimensional gravity coupled to topological matter, with a vanishing cosmological constant. We calculate the total energy, angular momentum and entropy of the black hole in this model and compare with results obtained in Einstein gravity. We find that the theory with topological matter reverses the identification of energy and angular momentum with the parameters in the metric, compared with general relativity, and that the entropy is determined by the circumference of the inner rather than the outer horizon. We speculate that this results from the contribution of the topological matter fields to the conserved currents. We also briefly discuss two new possible (2+1)-dimensional black holes.

S. Carlip; J. Gegenberg; R. B. Mann

1994-10-17T23:59:59.000Z

410

Statistical entropy of the Schwarzschild black hole  

E-Print Network (OSTI)

We derive the statistical entropy of the Schwarzschild black hole by considering the asymptotic symmetry algebra near the $\\cal{I^{-}}$ boundary of the spacetime at past null infinity. Using a two-dimensional description and the Weyl invariance of black hole thermodynamics this symmetry algebra can be mapped into the Virasoro algebra generating asymptotic symmetries of anti-de Sitter spacetime. Using lagrangian methods we identify the stress-energy tensor of the boundary conformal field theory and we calculate the central charge of the Virasoro algebra. The Bekenstein-Hawking result for the black hole entropy is regained using Cardy's formula. Our result strongly supports a non-local realization of the holographic principle

Mariano Cadoni

2005-11-09T23:59:59.000Z

411

Thermodynamic Curvature of the BTZ Black Hole  

E-Print Network (OSTI)

Some thermodynamic properties of the Baados-Teitelboim-Zanelli (BTZ) black hole are studied to get the effective dimension of its corresponding statistical model. For this purpose, we make use of the geometrical approach to the thermodynamics: Considering the black hole as a thermodynamic system with two thermodynamic variables (the mass M and the angular momemtum J), we obtain two-dimensional Riemannian thermodynamic geometry described by positive definite Ruppeiner metric. From the thermodynamic curvature we find that the extremal limit is the critical point. The effective spatial dimension of the statistical system corresponding to the near-extremal BTZ black holes is one. Far from the extremal point, the effective dimension becomes less than one, which leads to one possible speculation on the underlying structure for the corresponding statistical model. Typeset using REVTEX

Rong-gen Cai; Jin-ho Cho

1998-01-01T23:59:59.000Z

412

Comments on Information Erasure in Black Hole  

E-Print Network (OSTI)

This paper analyzes a certain model of information erasure by black hole and finds its major contradictions with the known laws of elementary physics. It has been demonstrated that the model in question leads to arbitrarily fast processes of information erasure. The proposed physical interpretation of information freezing at the event horizon as observed by an asymptotic observer is also showed to be fallacious. It has been clearly showed that quantum mechanics doesn't allow any information erasure, whatever the process may be, near the black hole horizon as long as the erasure process conforms to Landauer's principle. The later part of the work demonstrates the actual significance of the so called erasure entropy discussed in connection to quantum information erasure by black hole systems. It has been showed that erasure entropy is actually the mutual information between two subsystems and only arises when correlations between the respective subsystems are ignored.

Moinul Hossain Rahat; Avik Roy; Mishkat Al Alvi; Md. Abdul Matin

2013-11-03T23:59:59.000Z

413

Excited state structure, energy and electron transfer dynamics of photosynthetic reaction centers: A hole burning study  

SciTech Connect

The excited state structure, early time energy and electron transfer dynamics for bacterial photosynthetic reaction center of Rhodoseudomonas viridis, Rhodobacter sphaeroides and green plant photosynthetic reaction center of Photosystem 2 (PS 2) have been determined by hole burning spectroscopy. Transient hole burned spectra of the bacterial reaction centers reveal a special pair Franck-Condon marker mode progression with a superimposed zero phonon hole. Such progression is found to be absent in green plant Photosystem 2 which raises the question of structural similarities between the PS 2 and bacterial reaction centers. The excited state decay times are obtained for all systems and found to be consistent with time domain experiments. Similar temperature dependence of the decay kinetics have been observed for both bacterial and PS 2 reaction centers. Study of different preparations of reaction center of Photosystem 2 utilizing hole burning spectroscopy indicates that Triton X-100 detergent significantly affect the absorption and persistent hole burned spectra and disrupts the energy transfer from the accessory chlorophyll to the active pheophytin. The comparison between the bacterial reaction centers and Photosystem 2 has been presented and discussed in order to understand the difference in their early time dynamics and the excited state structure. A theoretical model has been developed based on the principle of linear electron-phonon coupling and imhomogeneous broadening. Our experimental results are found to be in good agreement with the theoretical calculations. 335 refs., 43 figs.

Tang, De-Ming.

1991-03-22T23:59:59.000Z

414

Simulations of Jets Driven by Black Hole Rotation  

E-Print Network (OSTI)

The origin of jets emitted from black holes is not well understood, however there are two possible energy sources, the accretion disk or the rotating black hole. Magnetohydrodynamic simulations show a well-defined jet that extracts energy from a black hole. If plasma near the black hole is threaded by large-scale magnetic flux, it will rotate with respect to asymptotic infinity creating large magnetic stresses. These stresses are released as a relativistic jet at the expense of black hole rotational energy. The physics of the jet initiation in the simulations is described by the theory of black hole gravitohydromagnetics.

Vladimir Semenov; Sergey Dyadechkin; Brian Punsly

2004-08-20T23:59:59.000Z

415

Thermal Gravitational Waves from Primordial Black Holes  

E-Print Network (OSTI)

Thermal gravitational waves can be generated in various sources such as, in the cores of stars, white dwarfs and neutron stars due to the fermion collisions in the dense degenerate Fermi gas. Such high frequency thermal gravitational waves can also be produced during the collisions in a gamma ray burst or during the final stages of the evaporation of primordial black holes. Here we estimate the thermal gravitational waves from primordial black holes and estimate the integrated energy of the gravitational wave emission over the entire volume of the universe and over Hubble time. We also estimate the gravitational wave flux from gamma ray bursts and jets.

C. Sivaram; Kenath Arun

2010-05-19T23:59:59.000Z

416

Black Hole Superradiance From Kerr/CFT  

E-Print Network (OSTI)

The superradiant scattering of a scalar field with frequency and angular momentum (\\omega,m) by a near-extreme Kerr black hole with mass and spin (M,J) was derived in the seventies by Starobinsky, Churilov, Press and Teukolsky. In this paper we show that for frequencies scaled to the superradiant bound the full functional dependence on (\\omega,m,M,J) of the scattering amplitudes is precisely reproduced by a dual two-dimensional conformal field theory in which the black hole corresponds to a specific thermal state and the scalar field to a specific operator. This striking agreement corroborates a conjectured Kerr/CFT correspondence.

Bredberg, Irene; Song, Wei; Strominger, Andrew

2009-01-01T23:59:59.000Z

417

Black Hole Superradiance From Kerr/CFT  

E-Print Network (OSTI)

The superradiant scattering of a scalar field with frequency and angular momentum (\\omega,m) by a near-extreme Kerr black hole with mass and spin (M,J) was derived in the seventies by Starobinsky, Churilov, Press and Teukolsky. In this paper we show that for frequencies scaled to the superradiant bound the full functional dependence on (\\omega,m,M,J) of the scattering amplitudes is precisely reproduced by a dual two-dimensional conformal field theory in which the black hole corresponds to a specific thermal state and the scalar field to a specific operator. This striking agreement corroborates a conjectured Kerr/CFT correspondence.

Irene Bredberg; Thomas Hartman; Wei Song; Andrew Strominger

2009-07-21T23:59:59.000Z

418

Normal Modes of Black Hole Accretion Disks  

SciTech Connect

This paper studies the hydrodynamical problem of normal modes of small adiabatic oscillations of relativistic barotropic thin accretion disks around black holes (and compact weakly magnetic neutron stars). Employing WKB techniques, we obtain the eigen frequencies and eigenfunctions of the modes for different values of the mass and angular momentum of the central black hole. We discuss the properties of the various types of modes and examine the role of viscosity, as it appears to render some of the modes unstable to rapid growth.

Ortega-Rodriguez, Manuel; /Stanford U., Appl. Phys. Dept. /Costa Rica U.; Silbergleit, Alexander S.; /Stanford U., HEPL; Wagoner, Robert V.; /Stanford U., Phys. Dept.

2006-11-07T23:59:59.000Z

419

Discrete Information from CHL Black Holes  

E-Print Network (OSTI)

AdS_2/CFT_1 correspondence predicts that the logarithm of a Z_N twisted index over states carrying a fixed set of charges grows as 1/N times the entropy of the black hole carrying the same set of charges. In this paper we verify this explicitly by calculating the microscopic Z_N twisted index for a class of states in the CHL models. This demonstrates that black holes carry more information about the microstates than just the total degeneracy.

Ashoke Sen

2010-02-22T23:59:59.000Z

420

Esimation of field-scale thermal conductivities of unsaturated rocks from in-situ temperature data  

E-Print Network (OSTI)

the wing heaters, and the RTD temperature holes in the DSTresistance temperature devices (RTD) placed in 26 boreholes.Sensor 60 being the last RTD in Borehole 79. The selected

Mukhopadhyay, Sumit; Tsang, Yvonne W.; Birkholzer, Jens T.

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature gradient holes" 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

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

422

The Plasma Puddle as a Perturbative Black Hole  

E-Print Network (OSTI)

We argue that the weak coupling regime of a large N gauge theory in the Higgs phase contains black hole-like objects. These so-called ``plasma puddles'' are meta-stable lumps of hot plasma lying in locally un-Higgsed regions of space. They decay via O(1/N) thermal radiation and, perhaps surprisingly, absorb all incident matter. We show that an incident particle of energy E striking the plasma puddle will shower into an enormous number of decay products whose multiplicity grows linearly with E, and whose average energy is independent of E. Once these ultra-soft particles reach the interior they are thermalized by the plasma within, and so the object appears ``black.'' We determine some gross properties like the size and temperature of the the plasma puddle in terms of fundamental parameters in the gauge theory. Interestingly, demanding that the plasma puddle emit thermal Hawking radiation implies that the object is black (i.e. absorbs all incident particles), which implies classical stability, which implies satisfaction of the Bekenstein entropy bound. Because of the AdS/CFT duality and the many similarities between plasma puddles and black holes, we conjecture that black objects are a robust feature of quantum gravity.

Clifford Cheung; Jared Kaplan

2007-04-09T23:59:59.000Z

423

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

424

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

425

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

426

A Mechanism for Coronal Hole Jets  

E-Print Network (OSTI)

Bald patches are magnetic topologies in which the magnetic field is concave up over part of a photospheric polarity inversion line. A bald patch topology is believed to be the essential ingredient for filament channels and is often found in extrapolations of the observed photospheric field. Using an analytic source-surface model to calculate the magnetic topology of a small bipolar region embedded in a global magnetic dipole field, we demonstrate that although common in closed-field regions close to the solar equator, bald patches are unlikely to occur in the open-field topology of a coronal hole. Our results give rise to the following question: What happens to a bald patch topology when the surrounding field lines open up? This would be the case when a bald patch moves into a coronal hole, or when a coronal hole forms in an area that encompasses a bald patch. Our magnetostatic models show that, in this case, the bald patch topology almost invariably transforms into a null point topology with a spine and a fan. We argue that the time-dependent evolution of this scenario will be very dynamic since the change from a bald patch to null point topology cannot occur via a simple ideal evolution in the corona. We discuss the implications of these findings for recent Hinode XRT observations of coronal hole jets and give an outline of planned time-dependent 3D MHD simulations to fully assess this scenario.

D. A. N. Mueller; S. K. Antiochos

2008-04-24T23:59:59.000Z

427

Hamiltonian thermodynamics of the Schwarzschild black hole  

E-Print Network (OSTI)

Kucha\\v{r} has recently given a detailed analysis of the classical and quantum geometrodynamics of the Kruskal extension of the Schwarzschild black hole. In this paper we adapt Kucha\\v{r}'s analysis to the exterior region of a Schwarzschild black hole with a timelike boundary. The reduced Lorentzian Hamiltonian is shown to contain two independent terms, one from the timelike boundary and the other from the bifurcation two-sphere. After quantizing the theory, a thermodynamical partition function is obtained by analytically continuing the Lorentzian time evolution operator to imaginary time and taking the trace. This partition function is in agreement with the partition function obtained from the Euclidean path integral method; in particular, the bifurcation two-sphere term in the Lorentzian Hamiltonian gives rise to the black hole entropy in a way that is related to the Euclidean variational problem. We also outline how Kucha\\v{r}'s analysis of the Kruskal spacetime can be adapted to the $\\RPthree$ geon, which is a maximal extension of the Schwarzschild black hole with $\\RPthree \\setminus \\{p\\}$ spatial topology and just one asymptotically flat region.

Jorma Louko; Bernard F. Whiting

1994-11-08T23:59:59.000Z

428

Publication List Francis Doan Hole, Professor Emeritus,  

E-Print Network (OSTI)

aerial mosaic soil maps of 13 towns of Grant Co.). Soil Survey Div., WGNHS, Univ. of Wisconsin and white or on aerial mosaics of 4 towns of Dodge Co.). Soil Survey Div., WGNHS, Univ. of Wisconsin., WI (with colored soil map). Bul. 74, Soil Survey Div., WGNHS, Univ. of Wisconsin- Madison. Hole, F

Balser, Teri C.

429

Remote down-hole well telemetry  

DOE Patents (OSTI)

The present invention includes an apparatus and method for telemetry communication with oil-well monitoring and recording instruments located in the vicinity of the bottom of gas or oil recovery pipes. Such instruments are currently monitored using electrical cabling that is inserted into the pipes; cabling has a short life in this environment, and requires periodic replacement with the concomitant, costly shutdown of the well. Modulated reflectance, a wireless communication method that does not require signal transmission power from the telemetry package will provide a long-lived and reliable way to monitor down-hole conditions. Normal wireless technology is not practical since batteries and capacitors have to frequently be replaced or recharged, again with the well being removed from service. RF energy generated above ground can also be received, converted and stored down-hole without the use of wires, for actuating down-hole valves, as one example. Although modulated reflectance reduces or eliminates the loss of energy at the sensor package because energy is not consumed, during the transmission process, additional stored extra energy down-hole is needed.

Briles, Scott D. (Los Alamos, NM); Neagley, Daniel L. (Albuquerque, NM); Coates, Don M. (Santa Fe, NM); Freund, Samuel M. (Los Alamos, NM)

2004-07-20T23:59:59.000Z

430

Low hole polaron migration barrier in lithium peroxide  

E-Print Network (OSTI)

We present computational evidence of polaronic hole trapping and migration in lithium peroxide (Li[subscript 2]O[subscript 2]), a material of interest in lithium-air batteries. We find that the hole forms in the ?* antibonding ...

Ong, Shyue Ping

431

Markovs maximon and quantum black holes  

Science Conference Proceedings (OSTI)

It is shown that the modern theory predicts the existence of a minimum mass of quantum black holes. Such minimal black holes are a natural candidate for the maximon

V. A. Berezin

1998-01-01T23:59:59.000Z

432

Phase 2 and 3 Slim Hole Drilling and Testing at the Lake City, California Geothermal Field  

DOE Green Energy (OSTI)

During Phases 2 and 3 of the Lake City GRED II project two slim holes were cored to depths of 1728 and 4727 ft. Injection and production tests with temperature and pressure logging were performed on the OH-1 and LCSH-5 core holes. OH-1 was permanently modified by cementing an NQ tubing string in place below a depth of 947 ft. The LCSH-1a hole was drilled in Quaternary blue clay to a depth of 1727 ft and reached a temperature of 193 oF at a depth of 1649 ft. This hole failed to find evidence of a shallow geothermal system east of the Mud Volcano but the conductive temperature profile indicates temperatures near 325 oF could be present below depth of 4000 ft. The LCSH-5 hole was drilled to a depth of 4727 ft and encountered a significant shallow permeability between depths of 1443 and 1923 ft and below 3955 ft. LCSH-5 drilled impermeable Quaternary fanglomerate to a depth of 1270 ft. Below 1270 ft the rocks consist primarily of Tertiary sedimentary rocks. The most significant formation deep in LCSH-5 appears to be a series of poikoilitic mafic lava flows below a depth of 4244 ft that host the major deep permeable fracture encountered. The maximum static temperature deep in LCSH-5 is 323 oF and the maximum flowing temperature is 329 oF. This hole extended the known length of the geothermal system by of a mile toward the north and is located over mile north of the northernmost hot spring. The OH-1 hole was briefly flow tested prior to cementing the NQ rods in place. This flow test confirmed the zone at 947 ft is the dominant permeability in the hole. The waters produced during testing of OH-1 and LCSH-5 are generally intermediate in character between the deep geothermal water produced by the Phipps #2 well and the thermal springs. Geothermometers applied to deeper fluids tend to predict higher subsurface temperatures with the maximum being 382 oF from the Phipps #2 well. The Lake City geothermal system can be viewed as having shallow (elevation > 4000 ft and temperatures of 270 to 310 oF), intermediate (elevation 2800 to 3700 ft and temperatures 270 to 320 oF ) and deep (elevations < 1000 ft and temperatures 323 to 337 oF) components. In the south part of the field, near Phipps #2 the shallow and deep components are present. In the central part of the field, near OH-1 the shallow and intermediate components are present and presumably the deep component is also present. In the north part of the field, the intermediate and deep components are present. Most or all of the fractures in the core have dips between 45 degrees and vertical and no strong stratigraphic control on the resource has yet been demonstrated. Conceptually, the Lake City geothermal resource seems to be located along the north-south trending range front in a relatively wide zone of fractured rock. The individual fractures do not seem to be associated with any readily identifiable fault. In fact, no major hydraulically conductive faults were identified by the core drilling.

Dick Benoit; David Blackwell; Joe Moore; Colin Goranson

2005-10-27T23:59:59.000Z

433

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.

434

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.

435

On Hawking radiation of 2d Liouville black hole  

E-Print Network (OSTI)

We adapt the method of complex paths to the study of the radiation of Hawking of Liouville black holes.

Chabab, M; Sedra, M B

2011-01-01T23:59:59.000Z

436

On the pattern of black hole information release  

E-Print Network (OSTI)

We propose a resolution to black hole information paradox by analyzing scattering amplitudes of a complex scalar field around a Schwarzschild black hole. The scattering cross section reveals much information on the incoming state but exhibits flux loss at the same time. The flux loss should be temporary, and indicate mass growth of the black hole. The black hole should Hawking-radiate subsequently, thereby, compensating for the flux loss.

Park, I Y

2013-01-01T23:59:59.000Z

437

Black Holes in Born-Infeld Extended New Massive Gravity  

E-Print Network (OSTI)

In this paper we find different types of black holes for the Born-Infeld extended new massive gravity. Our solutions include (un)charged (A)dS warped black holes for four and six derivative expanded action. We also look at the black holes in unexpanded action. In each case we calculate the entropy, angular momentum and the mass of the black holes.

Ghodsi, Ahmad

2010-01-01T23:59:59.000Z

438

The Black Holes do not exist - "Also Sprach Karl Schwarzschild"  

E-Print Network (OSTI)

According to the original theoretical analysis of 1916 by Karl Schwarzschild the black holes do not have a physical reality.

A. Loinger

2004-02-18T23:59:59.000Z

439

"Black Star" or Astrophysical Black Hole? K. Petrovay  

E-Print Network (OSTI)

"Black Star" or Astrophysical Black Hole? K. Petrovay Eötvös University, Department of Astronomy. Recently wide publicity has been given to a claim by T. Vachaspati that "black holes do not exist", that the objects known as black holes in astrophysics should rather be called "black stars" and they not only do

Petrovay, Kristóf

440

The Supermassive Black Hole at the Galactic Center  

E-Print Network (OSTI)

1 The Supermassive Black Hole at the Galactic Center Fulvio Melia 1 Physics Department and Steward, Auf dem Hugel 69, Bonn D-53121, Germany KEYWORDS: accretion, black hole physics, gas dynamics, jets the physics of black hole accretion, magnetized gas dynamics and unusual star formation. The Galactic Center

Falcke, Heino

Note: This page contains sample records for the topic "temperature gradient holes" 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

I. Review of the information problem and black hole complementarity  

E-Print Network (OSTI)

#12;I. Review of the information problem and black hole complementarity II. The firewall argument-th/9306083): Red: Scoarse (= SBekenstein-Hawking) of evaporating black hole. Blue: (SvN of radiation the black hole is still large (green). Asides: RS = M in Planck units, remnants, A vs. A3/4 S O(RS 3

442

A Link Between Black Holes and the Golden Ratio  

E-Print Network (OSTI)

We consider a variational formalism to describe black holes solution in higher dimensions. Our procedure clarifies the arbitrariness of the radius parameter and, in particular, the meaning of the event horizon of a black hole. Moreover, our formalism enables us to find a surprising link between black holes and the golden ratio.

J. A. Nieto

2011-06-02T23:59:59.000Z

443

Horizon Properties of Einstein-Yang-Mills Black Hole  

E-Print Network (OSTI)

We consider static axially symmetric Einstein-Yang-Mills black holes in the isolated horizon formalism. The mass of these hairy black holes is related to the mass of the corresponding particle-like solutions by the horizon mass. The hairy black holes violate the ``quasi-local uniqueness conjecture'', based on the horizon charges.

B. Kleihaus; J. Kunz; A. Sood; M. Wirschins

2001-10-19T23:59:59.000Z

444

An ant algorithm for optimization of hole-making operations  

Science Conference Proceedings (OSTI)

This paper deals with the optimization of hole-making operations in conditions where a hole may need several tools to get completed. The objective of interest in the considered problem is to minimize the summation of tool airtime and tool switch time. ... Keywords: Ant algorithms, Drilling, Hole-making, Optimization

Heidar Ghaiebi; Maghsud Solimanpur

2007-03-01T23:59:59.000Z

445

Black hole/string ball production, possibly at LHC  

E-Print Network (OSTI)

I show a brief historical overview of recent developments on the black hole physics that can be possibly explored at LHC. I comment on the correspondence principle of black holes and strings and show its realization in a differential production cross section of a black hole/string ball with fixed angular momentum.

Oda, Kin-ya

2010-01-01T23:59:59.000Z

446

Guanine tautomerism revealed by UVUV and IRUV hole burning spectroscopy  

E-Print Network (OSTI)

Guanine tautomerism revealed by UV­UV and IR­UV hole burning spectroscopy E. Nir Department spectroscopy. 1-methylguanine, in which the Keto­Enol tautomerism is blocked, shows hole burning spectra from hole burning SHB by using two counter- propagating dye laser pulses with a delay of about 150 ns

de Vries, Mattanjah S.

447

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.

448

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)

449

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)...

450

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

451

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

452

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

453

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)

454

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

455

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

456

Similarities and Differences between Coronal Holes and the Quiet Sun: Are Loop Statistics the Key?  

E-Print Network (OSTI)

Coronal holes (CH) emit significantly less at coronal temperatures than quiet-Sun regions (QS), but can hardly be distinguished in most chromospheric and lower transition region lines. A key quantity for the understanding of this phenomenon is the magnetic field. We use data from SOHO/MDI to reconstruct the magnetic field in coronal holes and the quiet Sun with the help of a potential magnetic model. Starting from a regular grid on the solar surface we then trace field lines, which provide the overall geometry of the 3D magnetic field structure. We distinguish between open and closed field lines, with the closed field lines being assumed to represent magnetic loops. We then try to compute some properties of coronal loops. The loops in the coronal holes (CH) are found to be on average flatter than in the QS. High and long closed loops are extremely rare, whereas short and low-lying loops are almost as abundant in coronal holes as in the quiet Sun. When interpreted in the light of loop scaling laws this result suggests an explanation for the relatively strong chromospheric and transition region emission (many low-lying, short loops), but the weak coronal emission (few high and long loops) in coronal holes. In spite of this contrast our calculations also suggest that a significant fraction of the cool emission in CHs comes from the open flux regions. Despite these insights provided by the magnetic field line statistics further work is needed to obtain a definite answer to the question if loop statistics explain the differences between coronal holes and the quiet Sun.

T. Wiegelmann; S. K. Solanki

2008-02-01T23:59:59.000Z

457

Slim Holes At Reese River Area (Henkle & Ronne, 2008) | Open Energy  

Open Energy Info (EERE)

Reese River Area (Henkle & Ronne, 2008) Reese River Area (Henkle & Ronne, 2008) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Reese River Area (Henkle & Ronne, 2008) Exploration Activity Details Location Reese River Area Exploration Technique Slim Holes Activity Date Usefulness useful DOE-funding Unknown Notes Well RR 56-4, was not successful in intersecting an exploitable geothermal resource. However, the lack of temperature reversal in the well and the geochemistry information obtained from fluid sampling point towards a large resource of moderate temperature. The encouraging results from 56-4 have lead to continued exploration on the project. The geologic and hydrologic information collected from 56-4 has proved an invaluable aid when combined

458

Trumpet-puncture initial data for black holes  

E-Print Network (OSTI)

We propose a new approach, based on the puncture method, to construct black hole initial data in the so-called trumpet geometry, i.e. on slices that asymptote to a limiting surface of non-zero areal radius. Our approach is easy to implement numerically and, at least for non-spinning black holes, does not require any internal boundary conditions. We present numerical results, obtained with a uniform-grid finite-difference code, for boosted black holes and binary black holes. We also comment on generalizations of this method for spinning black holes.

Jason D. Immerman; Thomas W. Baumgarte

2009-08-03T23:59:59.000Z

459

Observational studies of stellar black hole binaries and ULXs  

E-Print Network (OSTI)

We outline a framework for understanding the X-ray spectra of high mass accretion rate stellar black holes based on X-ray data from RXTE and ASCA. Three spectral regimes can be separated out by the behaviour of the observed disk luminosity and temperature. The well established "standard regime" is seen when the disk dominates the spectrum, where only a small fraction of the luminosity is emitted in the power law tail. These spectra generally satisfy the standard relation expected for thermal emission from a constant area, namely that the disk bolometric luminosity, Ldisk, is proportional to its maximum temperature, Tin^4. However, at higher luminosities this starts to change to Tin^2. This "apparently standard regime" is still dominated by the disk emission, but this difference luminosity-temperature relation and subtle changes in spectral shape may show that another cooling process is required in addition to radiative cooling. At intermediate luminosities there is an anomalous regime (or weak very high state...

Kubota, A; Kubota, Aya; Makishima, Kazuo

2005-01-01T23:59:59.000Z

460

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

Note: This page contains sample records for the topic "temperature gradient holes" 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

The hydraulic jump as a white hole  

E-Print Network (OSTI)

In the geometry of the circular hydraulic jump, the velocity of the liquid in the interior region exceeds the speed of capillary-gravity waves (ripplons), whose spectrum is `relativistic' in the shallow water limit. The velocity flow is radial and outward, and thus the relativistic ripplons cannot propagating into the interior region. In terms of the effective 2+1 dimensional Painleve-Gullstrand metric appropriate for the propagating ripplons, the interior region imitates the white hole. The hydraulic jump represents the physical singularity at the white-hole horizon. The instability of the vacuum in the ergoregion inside the circular hydraulic jump and its observation in recent experiments on superfluid 4He by E. Rolley, C. Guthmann, M.S. Pettersen and C. Chevallier in physics/0508200 are discussed.

G. E. Volovik

2005-08-30T23:59:59.000Z

462

Slant hole completion test. Final report  

Science Conference Proceedings (OSTI)

One of the Department of Energy`s (DOE) Strategies and Objectives in the Natural Gas Program is to conduct activities to transfer technology from R&D programs to potential users. The Slant Hole Completion Test has achieved exactly this objective. The Slant Hole site is essentially the same as the Multiwell site and is located in the southeastern portion of the Piceance Basin near Rifle, Colorado. The Piceance Basin is typical of the Western low permeability basins that contain thick sequences of sands, silts and coals deposited during the Cretaceous period. These sequences contain vast amounts of natural gas but have proven to be resistant to commercial production because of the low permeability of the host rocks. Using the knowledge gained from the DOE`s earlier Multiwell experiment, the SHCT-1 was drilled to demonstrate that by intersecting the natural fractures found in these ``tight rocks,`` commercial gas production can be obtained.

Mann, R.L.

1993-07-01T23:59:59.000Z

463

Nonstationary dark energy around a black hole  

Science Conference Proceedings (OSTI)

Numerical simulations of the accretion of test scalar fields with nonstandard kinetic terms (of the k-essence type) onto a Schwarzschild black hole are performed. We find a full dynamical solution for the spherical accretion of a Dirac-Born-Infeld type scalar field. The simulations show that the accretion eventually settles down to a well-known stationary solution. This particular analytical steady state solution maintains two separate horizons. The standard horizon is for the usual particles propagating with the limiting speed of light, while the other sonic horizon is for the k-essence perturbations propagating with the speed of sound around this accreting background. For the case where the k-essence perturbations propagate superluminally, we show that one can send signals from within a black hole during the approach to the stationary solution. We also find that a ghost condensate model settles down to a stationary solution during the accretion process.

Akhoury, Ratindranath; Saotome, Ryo [Michigan Center for Theoretical Physics, Randall Laboratory of Physics, University of Michigan, Ann Arbor, Michigan 48109-1120 (United States); Garfinkle, David [Department of Physics, Oakland University, Rochester, Michigan 48309 (United States); Michigan Center for Theoretical Physics, Randall Laboratory of Physics, University of Michigan, Ann Arbor, Michigan 48109-1120 (United States); Vikman, Alexander [Theory Division, CERN, Geneva 23, CH-1211 (Switzerland)

2011-04-15T23:59:59.000Z

464

Geometric description of BTZ black holes thermodynamics  

E-Print Network (OSTI)

We study the properties of the space of thermodynamic equilibrium states of the Ba\\~nados-Teitelboim-Zanelli (BTZ) black hole in (2+1)-gravity. We use the formalism of geometrothermodynamics to introduce in the space of equilibrium states a $2-$dimensional thermodynamic metric whose curvature is non-vanishing, indicating the presence of thermodynamic interaction, and free of singularities, indicating the absence of phase transitions. Similar results are obtained for generalizations of the BTZ black hole which include a Chern-Simons term and a dilatonic field. Small logarithmic corrections of the entropy turn out to be represented by small corrections of the thermodynamic curvature, reinforcing the idea that thermodynamic curvature is a measure of thermodynamic interaction.

Hernando Quevedo; Alberto Sanchez

2008-11-15T23:59:59.000Z

465

Laser stabilization using spectral hole burning  

E-Print Network (OSTI)

We have frequency stabilized a Coherent CR699-21 dye laser to a transient spectral hole on the 606 nm transition in Pr^{+3}:Y_2SiO_5. A frequency stability of 1 kHz has been obtained on the 10 microsecond timescale together with a long-term frequency drift below 1 kHz/s. RF magnetic fields are used to repopulate the hyperfine levels allowing us to control the dynamics of the spectral hole. A detailed theory of the atomic response to laser frequency errors has been developed which allows us to design and optimize the laser stabilization feedback loop, and specifically we give a stability criterion that must be fulfilled in order to obtain very low drift rates. The laser stability is sufficient for performing quantum gate experiments in Pr^{+3}:Y_2SiO_5.

L. Rippe; B. Julsgaard; A. Walther; S. Krll

2006-11-05T23:59:59.000Z

466

Hydrodynamics of R-charged black holes  

E-Print Network (OSTI)

We consider hydrodynamics of N=4 supersymmetric SU(N_c) Yang-Mills plasma at a nonzero density of R-charge. In the regime of large N_c and large 't Hooft coupling the gravity dual description involves an asymptotically Anti- de Sitter five-dimensional charged black hole solution of Behrnd, Cvetic and Sabra. We compute the shear viscosity as a function of chemical potentials conjugated to the three U(1) \\subset SO(6)_R charges. The ratio of the shear viscosity to entropy density is independent of the chemical potentials and is equal to 1/4\\pi. For a single charge black hole we also compute the thermal conductivity, and investigate the critical behavior of the transport coefficients near the boundary of thermodynamic stability.

Dam T. Son; Andrei O. Starinets

2006-01-20T23:59:59.000Z

467

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

468

Static Temperature Survey At Blue Mountain Area (Fairbank Engineering,  

Open Energy Info (EERE)

Static Temperature Survey At Blue Mountain Area (Fairbank Engineering, Static Temperature Survey At Blue Mountain Area (Fairbank Engineering, 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Static Temperature Survey At Blue Mountain Area (Fairbank Engineering, 2010) Exploration Activity Details Location Blue Mountain Area Exploration Technique Static Temperature Survey Activity Date Usefulness useful DOE-funding Unknown Notes Using a precision thermistor probe, EGI, University of Utah, obtained detailed temperature logs of eleven new mineral exploration holes drilled at Blue Mountain. The holes, ranging in depth from 99 to 244 meters (325 to 800 feet), were drilled in areas to the northeast, northwest and southwest of, and up to distances of two kilometers from, the earlier mineral exploration drill holes that encountered hot artesian flows. Unfortunately,

469

Band or Polaron: The Hole Conduction Mechanism in the p-Type Spinel Rh 2ZnO4  

DOE Green Energy (OSTI)

Given the emerging role of oxide spinels as hole conductors, we discuss in this article the traditional vs. new methodologies of determining the type of conduction mechanism at play - localized polaronic vs. band-like transport. Applying (i) traditional small polaron analysis to our in-situ high temperature four-point conductivity and thermopower measurements, we previously found an activated mobility, which is indicative of the small polaron mechanism. However, (ii) employing the recent developments in correcting density functional methodologies for hole localization, we predict that the self-trapped hole is unstable and that Rh{sub 2}ZnO{sub 4} is instead a band conductor with a large effective mass. The hole mobility measured by high-field room temperature Hall effect also suggests band rather than polaron conduction. The apparent contradiction between the conclusion of the traditional procedure (i) and first-principles theory (ii) is resolved by taking into account in the previous transport analysis the temperature dependence of the effective density of states, which leads to the result that the mobility is actually temperature-independent in Rh{sub 2}ZnO{sub 4}. Our case study on Rh{sub 2}ZnO{sub 4} illustrates the range of experimental and theoretical approaches at hand to determine whether the transport mechanism of a semiconductor is band or small polaron conduction.

Nagaraja, A. R.; Perry, N. H.; Mason, T. O.; Tang, Y.; Grayson, M.; Paudel, T. R.; Lany, S.; Zunger, A.

2012-01-01T23:59:59.000Z

470

Mechanisms Contributing to the Warming Hole and the Consequent U.S. EastWest Differential of Heat Extremes  

Science Conference Proceedings (OSTI)

A linear trend calculated for observed annual mean surface air temperatures over the United States for the second-half of the twentieth century shows a slight cooling over the southeastern part of the country, the so-called warming hole, while ...

Gerald A. Meehl; Julie M. Arblaster; Grant Branstator

2012-09-01T23:59:59.000Z

471

Interpreting Conductivity Microstructure: Estimating the Temperature Variance Dissipation Rate  

Science Conference Proceedings (OSTI)

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

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

1996-12-01T23:59:59.000Z

472

Sources of cosmic microwave radiation and dark matter identified: millimeter black holes (m.b.h.)  

E-Print Network (OSTI)

The universe is filled with blackbody millimeter radiation (CMBR), temperature 2.7{\\deg} Kelvin[1]. Big-bang cosmology explains this by the initial thermalization of photons scattered by electrons[2]. This explanation requires ad hoc previous existence of photons and thermal electrons. On the other hand most of the mass of the universe is unknown dark matter3. It explains anomalous dynamical properties, like that of stars in galaxies[4,5,6] . Alternatively the anomalies have been explained by adjusting and modifying well known laws ("Modified Newtonian dynamics"[7]). Here we show that millimeter black holes (m.b.h.) explain both: the background radiation, by its partial "evaporation", and the dark matter. Black holes emit blackbody radiation (Hawking[8] evaporation), and this is what is observed in the CMBR. Millimeter size black holes emit blackbody radiation at a temperature of 2.7{\\deg} Kelvin, and this is the resulting CMBR . Partial evaporation of ~10^30 m.b.h. gives the observed background field of photons being emitted and absorbed at the same rate by the m.b.h. The number of photons is constant, as observed. Their temperature decreases with time because the mass of the m.b.h. (and therefore its size) increases with time (the mass-boom effect[9]). The total mass of the m.b.h. is the dark matter. Hence dark matter is not so "dark" after all. Two important cosmological items are here identified by only one source: millimeter black holes.

Antonio Alfonso-Faus; Marius Josep Fullana i Alfonso

2010-04-13T23:59:59.000Z

473

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

Open Energy Info (EERE)

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

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