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1

Static downhole characteristics of well CGEH-1 at Coso Hot Springs, China Lake, California  

Microsoft Academic Search

A series of measurements was made in the exploratory well CGEH-1 at Coso Hot Springs. The temperature measurements provide estimates for the thermal equilibration of the well and indicate that the fractures intersecting the well have different temperatures. The hottest fractures are in the upper-cased portion of the well. Downhole chemical sampling suggests that the borehole still contains remnants of

C. Goranson; R. Schroeder

1978-01-01

2

Evaluation of Coso Geothermal Exploratory Hole No. 1 (CGEH-1) Coso Hot Springs: KGRA, China Lake, CA  

Microsoft Academic Search

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,

C. Goranson; R. Schroeder; J. Haney

1979-01-01

3

Coso Hot Springs: A Condensate Fed Geothermal Feature  

Microsoft Academic Search

The Coso Hot Springs are located almost two miles from the Coso geothermal field within the China Lake Naval Air Weapons Station, China Lake, California. The hot springs are about 16 m above the adjacent valley floor and because of their position are not believed to be in good hydrologic connection with the regional groundwater water table. Shortly after the

M. A. Person; D. Cohen; A. Sabin; J. Unruh; C. Gable; G. Zyvoloski; D. Meade; S. Bjornstad; F. Monastero

2007-01-01

4

Coso Hot Springs: A Condensate Fed Geothermal Feature  

NASA Astrophysics Data System (ADS)

The Coso Hot Springs are located almost two miles from the Coso geothermal field within the China Lake Naval Air Weapons Station, China Lake, California. The hot springs are about 16 m above the adjacent valley floor and because of their position are not believed to be in good hydrologic connection with the regional groundwater water table. Shortly after the onset of geothermal production in 1987, both water levels and temperatures within the South Pool of Coso Hot Springs increased. Although water levels appeared to be stable by 1989-1990, temperatures continued to rise until about 1993. We postulate that Coso hot springs are a condensate fed geothermal feature associated with vapor flux emanating from the Coso Wash Fault. We developed a suite of generic and site specific numerical models using FEHM to test whether these measured changes in the hot springs might be due to the removal of fluids associated with production from the Coso geothermal field. The idealized models were based on observed conditions including the locations of faults and geologic framework as well as temperature/pressure/production history of the geothermal field. The model results suggest that pressure declines associated with geothermal production led to an expanded steam cap which resulted in an enhanced vapor flux up the Coso Wash Fault zone.

Person, M. A.; Cohen, D.; Sabin, A.; Unruh, J.; Gable, C.; Zyvoloski, G.; Meade, D.; Bjornstad, S.; Monastero, F.

2007-12-01

5

Significant role of climatic trends on hydrothermal activity Coso Hot Springs, California  

Microsoft Academic Search

The hydrothermal features of Coso Hot Springs have attracted visitors for 130 yr and scientific investigators for two decades. In 1978, anticipating effects of major geothermal developments nearby, the Naval Weapons Center (NWC) initiated a comprehensive monitoring program at a dozen hydrothermal sites in the Coso Hot Springs area. Nine years of monitoring preceded power production in the nearby Coso

Ben E. Lofgren

1990-01-01

6

Variation in sericite compositions from fracture zones within the Coso Hot Springs geothermal system  

Microsoft Academic Search

Two types of white micas are found in drillhole samples within the geothermal system at Coso Hot Springs. Low-permeability zones of the crystalline basement contain coarse-grained relict muscovite, whereas rock alteration near fracture zones at temperatures > 150°C is characterized by abundant finegrained sericite in association with secondary calcite and quartz and unaltered relict microcline. In this hydrothermal sericite there

Barbara P. Bishop; Dennis K. Bird

1987-01-01

7

Three-dimensional Q-1 model of the Coso Hot Springs known geothermal resource area  

Microsoft Academic Search

Observations of teleseismic P waves above geothermal systems exhibit travel time delays and anomalously high seismic attenuation, which is extremely useful in estimating the thermal regime and the potential of the system. A regional telemetered network of sixteen stations was operated by the U.S. Geological Survey in the Coso Hot Springs Known Geothermal Resources Area (KGRA) for such studies from

Chi-Yuh Young; Ronald W. Ward

1980-01-01

8

Alicyclobacillus vulcanalis sp. nov., a thermophilic, acidophilic bacterium isolated from Coso Hot Springs, California, USA.  

PubMed

A thermo-acidophilic Gram-positive bacterium, strain CsHg2T, which grows aerobically at 35-65 degrees C (optimum 55 degrees C) and at pH 2.0-6.0 (optimum 4.0), was isolated from a geothermal pool located in Coso Hot Springs in the Mojave Desert, California, USA. Phylogenetic analysis of 16S rRNA gene sequences showed that this bacterium was most closely related to the type strains of Alicyclobacillus acidocaldarius (97.8 % identity) and Alicyclobacillus sendaiensis (96.9 %), three Japanese strains denoted as UZ-1, KHA-31 and MIH 332 (96.1-96.5 %) and Alicyclobacillus genomic species FR-6 (96.3 %). Phenotypic characteristics including temperature and pH optima, G+C composition, acid production from a variety of carbon sources and sensitivity to different metal salts distinguished CsHg2T from A. acidocaldarius, A. sendaiensis and FR-6. The cell lipid membrane was composed mainly of omega-cyclohexyl fatty acid, consistent with membranes from other Alicyclobacillus species. Very low DNA-DNA hybridization values between CsHg2T and the type strains of Alicyclobacillus indicate that CsHg2T represents a distinct species. On the basis of these results, the name Alicyclobacillus vulcanalis sp. nov. is proposed for this organism. The type strain is CsHg2T (ATCC BAA-915T = DSM 16176T). PMID:15388732

Simbahan, Jessica; Drijber, Rhae; Blum, Paul

2004-09-01

9

Summary of basic hydrologic data collected at Coso Hot Springs, Inyo County, California  

USGS Publications Warehouse

More than 200 wells and springs were visited within a 20-mile radius of Coso Hot Springs, Calif. Hydrologic and geothermal data were collected for each well or spring site. The data includes depth, chemical quality, temperature and specific conductance of water, quantity of flow, well construction, and well logs. These data show that the normal temperature gradient in the ground is about 1.1 degrees Celsius (2 degrees Fahrenheit) per 100 feet. The temperature gradient in the thermal areas is as high as 24.4 degrees Celsius (44 degrees Fahrenheit) per 100 feet. The highest temperature measured for all the wells and springs was 142.2 degrees Celsius (288 degrees Fahrenheit). The chemical quality of water in the study area is generally good except in areas where water evaporates from land surface at Owens Valley playa or where steam escapes into the atmosphere from land surface. Computerized hydrologic and geothermal data are being stored for future use at the U.S. Geological Survey office, Laguna Niguel, Calif. (Woodard-USGS)

Moyle, W.R.

1977-01-01

10

Coso Monitoring Program, October 1992 through September 1993  

SciTech Connect

The Coso Monitoring Program is a continuing effort in support of the Navy's geothermal resources within the Known Geothermal Resource Area (KGRA). Data are presented on the monitoring of steam flow rates and temperatures, water levels in ponds and wells, water chemistry, and rainfall in the Coso Hot Springs Resort Area. A monthly photographic essay of the mudfields and pools shows the variation of the surface water levels throughout the year. Coso monitor program, Steam Flow, Coso hot springs, Barometric pressure, Environmental monitoring, Water analysis, Ambient temperature, Geothermal development, Water level, Relative humidity.

Bjornstad, S.C.; Monahan, J.H.; Sprouse, J.K.

1994-01-01

11

Coso Monitoring Program. Summary report, October 1985-September 1986  

SciTech Connect

The Coso Monitoring Program is a continuing effort in support of the development of the Navy's Geothermal Resources within the Coso Known Geothermal Resource Area (KGRA). Data are presented on the monitoring of steam flow rates and temperatures, water levels in ponds and wells, water chemistry, temperature logs of shallow wells and rainfall in the Coso Hot Springs Resort Area. A weekly photographic essay of the mud pots and pools shows the variation of surface-water levels throughout the year.

Edwards, E.M.

1987-02-01

12

Coso monitoring program, January 1981 through December 1983. Summary report  

SciTech Connect

The Coso monitoring program is a continuing effort in support of the development of the Navy's geothermal resources within the Coso Known Geothermal Resource Area (KGRA). Data are presented on the monitoring of steam flow rates and temperatures, water levels in ponds and wells, water chemistry, temperature logs of shallow wells, and rainfall in the Coso Hot Springs Resort area. A weekly photographic essay of the mud pots and pools shows the variation of surface water levels thoughout the year.

Bjornstad, S.C.; Rodgers, C.R.

1984-09-01

13

75 FR 76455 - Coso Energy Developers; Coso Finance Partners; Coso Power Developers; Notice Of Filing  

Federal Register 2010, 2011, 2012, 2013

...DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL11-4-000] Coso Energy Developers; Coso Finance Partners; Coso Power Developers; Notice Of Filing December 1, 2010. Take notice that on November 18,...

2010-12-08

14

Coso monitoring program, January 1984 through September 1985. Summary report, January 1984-September 1985  

SciTech Connect

The Coso monitoring program is a continuing effort in support of the development of the Navy's geothermal resources within the Coso Known Geothermal Resource Area (KGRA). Data are presented on the monitoring of steam flow rates and temperatures, water levels in ponds and wells, water chemistry, temperature logs of shallow wells, and rainfall in the Coso Hot Springs Resort area. A weekly photographic essay of the mud pots and pools shows the variation of surface-water levels throughout the year.

Bjornstad, S.C.; Edwards, E.M.

1986-01-01

15

Coso Geothermal Corrosion Studies.  

National Technical Information Service (NTIS)

This report documents the results of geothermal corrosion studies conducted at the Coso Thermal Area, Naval Weapons Center, China Lake, California. Nine different common construction-grade piping materials were tested for periods up to about one year in t...

S. A. Finnegan

1977-01-01

16

Heat flow and microearthquake studies, Coso Geothermal Area, China Lake, California. Final report  

Microsoft Academic Search

The present research effort at the Coso Geothermal Area located on the China Lake Naval Weapons Center, China Lake, California, was concerned with: (1) heat flow studies and (2) microearthquake studies associated with the geothermal phenomena in the Coso Hot Springs area. The sites for ten heat flow boreholes were located primarily using the available seismic ground noise and electrical

1975-01-01

17

Interpretation of chemical analyses of waters collected from two geothermal wells at Coso, California  

Microsoft Academic Search

Wellhead and downhole water samples were collected and analyzed from a 114.3-m well at Coso Hot Springs (Coso No. 1) and a 1477-m well (CGEH No. 1) 3.2 km to the west. The same chloride concentration is present in hot waters entering both wells (about 2350 mg\\/kg), indicating that a hot-water-dominated geothermal system is present. The maximum measured temperatures are

R. O. Fournier; J. M. Thompson; C. F. Austin

1980-01-01

18

Isotope Transport and Exchange within the Coso Geothermal System  

NASA Astrophysics Data System (ADS)

We are investigating the plumbing of the Coso geothermal system and the nearby Coso Hot Springs using finite element models of single-phase, variable-density fluid flow, conductive-convective heat transfer, fluid-rock isotope exchange, and groundwater residence times. Using detailed seismic reflection data and geologic mapping, we constructed a regional cross-sectional model that extends laterally from the Sierra Nevada to Wildhorse Mesa, west of the Argus Range. The base of the model terminates at the brittle-ductile transition zone. A sensitivity study was conducted using the model to explore the interaction between local and mountain front recharge, the effects of spatial variations in heat flow, and the role of permeable faults in controlling fluid circulation patterns. The model is constrained by present day bore hole temperature surveys, fluid inclusion temperatures, fluid-rock isotopic alteration patterns, and hot spring activity. While the results are non-unique, the analysis permits us to bracket the likely ranges of permeabilities and heat flow conditions that are consistent with observed data. Our findings suggest that active faults and seismogenic zones in and around the Coso geothermal area have much higher permeability and reactive surface areas than far field crustal rocks such as those in the Sierra Nevada. The Coso Wash fault zone must extend down to brittle- ductile transition zone depths of about 4 km in order for modeled results to match the observed hot spring activity.

Person, M.; Cohen, D.; Sabin, A.; Unruhn, J.; Gable, C.; Zyvoloski, G.; Monastero, F.

2006-12-01

19

Coso monitoring program, October 1993 through September 1994. Report for 1 October 1993-30 September 1994  

SciTech Connect

The Coso Monitoring Program is a continuing effort in support of the Navy`s geothermal resources within the Known Geothermal Resource Area (KGRA). Data are presented on the monitoring of steam flow rates and temperatures, water levels in ponds and wells, water chemistry, and rainfall in the Coso Hot Springs Resort Area. A monthly photographic essay of the mudfields and pools shows the variation of the surface water levels throughout the year.

Bjornstad, S.C.; Monahan, J.H.; Sprouse, J.K.

1995-01-01

20

Coso geothermal - The quiet giant  

SciTech Connect

Now second in size in the US and exceeded in production only by Italy, Mexico, the Philippines, and the US as a whole, the Coso geothermal project remains relatively unknown to both academia and industry. An entrepreneurial minded group of people in the US Navy teamed up with private industry, the California Energy Company, to create a legal/institutional environment within which a fast track geothermal project could go into production. The problems and hurdles were legion - was there even a resource, could Navy weapons projects tolerate a multiple-use mineral project on military lands, could resource people team up with the electron makers to grasp this novel opportunity the navy was making available, could the banking community accept this hybrid type of project The answers have been consistently yes, but not without work by a lot of people. Coso, presently, has six turbines running and three nearing completion for a total of 230 MW. This successful multiple-use mineral project located on a military weapons test range, offers industry and the military community an example and a guide for future multiple-use projects.

Austin, C.F. (American Association of Petroleum Engineering, China Lake, CA (USA)); Moore, J.L. (California Energy Co., Inc., Santa Rosa (USA))

1990-05-01

21

Geologic Study of the Coso Formation  

SciTech Connect

There have been great advances in the last 20 years in understanding the volcanic, structural, geophysical, and petrologic development of the Coso Range and Coso geothermal field. These studies have provided a wealth of knowledge concerning the geology of the area, including general structural characteristics and kinematic history. One element missing from this dataset was an understanding of the sedimentology and stratigraphy of well-exposed Cenozoic sedimentary strata - the Coso Formation. A detailed sedimentation and tectonics study of the Coso Formation was undertaken to provide a more complete picture of the development of the Basin and Range province in this area. Detailed mapping and depositional analysis distinguishes separate northern and southern depocenters, each with its own accommodation and depositional history. While strata in both depocenters is disrupted by faults, these faults show modest displacement, and the intensity and magnitude of faulting does no t record significant extension. For this reason, the extension between the Sierran and Coso blocks is interpreted as minor in comparison to range bounding faults in adjacent areas of the Basin and Range.

D. L. Kamola; J. D. Walker

1999-12-01

22

Coso monitoring program. Summary report Jan-Dec 80  

SciTech Connect

The Coso Monitoring Program is a continuing effort in support of the geothermal development of Coso, which is located within the boundaries of the Naval Weapons Center. Data are presented on the monitoring of steam flows, water levels in ponds and wells, water chemistry, temperature logs of shallow wells, and rainfall at the Coso Resort. A weekly photographic investigation of the mud pots shows the variation of fluid levels in the mud pots during the wet and dry seasons.

Rodgers, C.R.; Edwards, E.M.; Bowles, D.L.

1981-12-01

23

Absence of dynamic triggering inside the Coso geothermal field following the 1992 Mw7.3 Landers earthquake: an indication of low pore pressure?  

NASA Astrophysics Data System (ADS)

Geothermal fields are often considered to be susceptible to dynamic triggering because they are likely to be at near-critical stress state and involved with fluid movement in tectonically active extensional regimes. The 1992 Mw7.3 Landers earthquake dynamically triggered widespread earthquakes, especially at active geothermal areas, such as Long Valley, the Geysers and Coso (Hill et al., 1993). Dynamic triggering in Coso, southern California, is often referred to the broad area around the geothermal field. In this study, we investigate the spatial distribution of triggered events in Coso following the Landers earthquake and find no triggered events inside the geothermal field. The Coso geothermal production area is around 6*10 km2, confined between the Coso Hot Springs and the Sugarloaf Mountain. We estimate the b-value and completeness magnitude from a relocation catalog in the geothermal field to be 1.09 and M1.0, respectively. Based on the relocations for events above magnitude 1.0, we select seven small areas to compare the seismicity rate before and after the Landers earthquake. No seismicity was detected inside the geothermal field within 30 days after the Landers earthquake, whereas the surrounding fault zones outside of the geothermal field display strong elevated seismicity rate, including a segment of the Airport Lake Fault zone where the background seismicity was low before the Landers earthquake. The production area lacking of triggered events correlates with strong subsidence from the InSAR study by Fialko and Simons (2000), which may indicate low pore pressure in the area. This observation is further supported by the low Vp/Vs ratios from our recent 3D tomography model since Vp/Vs ratio decreases with pore pressure reduction (Ito et al., 1979, Christensen, 1984). Our results imply that the geothermal production of hot water and steam in Coso may have decreased the pore pressure and brought the stress state away from the critical state.

Zhang, Q.; Lin, G.; Zhan, Z.

2013-12-01

24

Microearthquake moment tensors from the Coso Geothermal area  

SciTech Connect

The Coso geothermal area, California, has produced hot water and steam for electricity generation for more than 20 years, during which time there has been a substantial amount of microearthquake activity in the area. Seismicity is monitored by a high-quality permanent network of 16 three-component digital borehole seismometers operated by the US Navy and supplemented by a ~ 14-station portable array of surface three-component digital instruments. The portable stations improve focal sphere coverage, providing seismic-wave polarity and amplitude data sets sufficient for determining full moment-tensor microearthquake mechanisms by the linearprogramming inversion method. We have developed a GUI-based interface to this inversion software that greatly increases its ease of use and makes feasible analyzing larger numbers of earthquakes than previously was practical. We show examples from an injection experiment conducted in well 34-9RD2, on the East Flank of the Coso geothermal area. This tight well was re-drilled February – March 2005 with the intention of hydrofracturing it, but instead, pervasive porosity and fractures were encountered at about 2660 m depth. Total drilling mud losses occurred, obviating the need to stimulate the well. These mud losses induced a 50-minute swarm of 44 microearthquakes, with magnitudes in the range -0.3 to 2.6. Most of the largest microearthquakes occurred in the first 2 minutes. Accurate relative relocations and moment tensors for the best-recorded subset reveal fine details of the fracture that was stimulated. This comprised a fault striking at N 20° E and dipping at 75° to the WNW, which propagated to the NNE and upward. Co-injection focal mechanisms reveal combined crack-opening and shear motion. Stress release and mode of failure differed between the pre-, co- and post-swarm periods. Some post-swarm events involved cavity collapse, suggesting that some of the cavity opening caused by the fluid injection was quickly reversed. Stress & mode of failure had not returned to pre-swarm conditions within 1 month following the injection, posing the question of how long stress perturbations persist following a stimulation experiment. This question may be answered by processing data spanning a longer postinjection period, work that is currently underway and will be reported in this presentation.

Julian, B.R.; G.R. Foulger; F. Monastero

2007-04-01

25

The Coso EGS project - Recent developments  

USGS Publications Warehouse

An Engineered Geothermal System (EGS) field experiment will be conducted to hydraulically stimulate injection well 34-9RD2, located on the east flank of the Coso geothermal reservoir, with the objective of increasing the injection rate of this well to 750 gpm at a wellhead pressure of 100 psi or less. The stimulation of this well is expected to create hydraulic communication with the recently drilled production well 38C-9, which is directly south of 34-9RD2. We summarize the results of fracture and stress analyses based upon borehole image logs of 38C-9; petrographic and petrologic analyses of cuttings from both the injection well 34-9RD2 and the production well 38C-9; and plans for the redrilling and stimulation of 34-9RD2.

Rose, P.; Sheridan, J.; McCulloch, J.; Moore, J.N.; Kovac, K.; Spielman, P.; Weidler, R.; Hickman, S.

2004-01-01

26

The coso EGS project - Recent developments  

USGS Publications Warehouse

An Enhanced Geothermal System (EGS) field experiment will be conducted to hydraulically stimulate injection well 34-9RD2, located on the east flank of the Coso geothermal reservoir, with the objective of increasing the injection rate of this well to 750 gpm at a wellhead pressure of 100 psi or less. The stimulation of this well is expected to create hydraulic communication with the recently drilled production well 38C-9, which is directly south of 34-9RD2. We summarize the results of fracture and stress analyses based upon borehole image logs of 38C-9; petrographic and petrologic analyses of cuttings from both the injection well 34-9RD2 and the production well 38C-9; and plans for the redrilling and stimulation of 34-9RD2.

Rose, P.; Sheridan, J.; McCulloch, J.; Moore, J.N.; Kovac, K.; Weidler, R.; Hickman, S.

2005-01-01

27

Coso geothermal environmental overview study ecosystem quality  

SciTech Connect

The Coso Known Geothermal Resource Area is located just east of the Sierra Nevada, in the broad transition zone between the Mohave and Great Basin desert ecosystems. The prospect of large-scale geothermal energy development here in the near future has led to concern for the protection of biological resources. Objectives here are the identification of ecosystem issues, evaluation of the existing data base, and recommendation of additional studies needed to resolve key issues. High-priority issues include the need for (1) site-specific data on the occurrence of plant and animal species of special concern, (2) accurate and detailed information on the nature and extent of the geothermal resource, and (3) implementation of a comprehensive plan for ecosystem protection.

Leitner, P.

1981-09-01

28

A joint geophysical analysis of the Coso geothermal field, south-eastern California  

NASA Astrophysics Data System (ADS)

Three-dimensional density models derived from gravity data and two-dimensional resistivity models derived from magnetotelluric data collected in the vicinity of the Coso geothermal field are analyzed in order to determine the source region of the geothermal field. The derived models show zones of both low resistivity and low density at and below 6 km depth in the Devils Kitchen and the Coso Hot Springs areas. These zones agree with seismic reflection and tomography results which found a high amplitude reflector at 5 km and low velocities zones below 5 km. We interpret the density and resistivity zones to indicate the presence of cooling magmatic material that provides the heat for the shallower geothermal system in these regions. A zone marked by high resistivity and low density was found to lie directly above the interpreted partially melted region extending to within 1 km depth below the surface in the reservoir region where it is capped by a low resistivity clay zone. In addition, the density models indicate that the high density bodies occurring under volcanic outcrops may be mafic intrusions.

Wamalwa, Antony M.; Mickus, Kevin L.; Serpa, Laura F.; Doser, Diane I.

2013-01-01

29

Coso monitoring program. Final report, October 1994-September 1995  

SciTech Connect

The Coso Monitoring Program is a continuing effort in support of the Navy`s geothermal resources within the Known Geothermal Resource Area (KORA). Because the project is essentially the same from year to year, the previously published reports share similarities of text that aren`t repeated in this period`s report. This report concentrates instead on data presentation and interpretation.

Bjornstad, S.C.

1996-01-01

30

Heat flow in the Coso geothermal area, Inyo County, California  

Microsoft Academic Search

Obvious surface manifestations of an anomalous concentration of geothermal resources at the Coso geothermal area, Inyo County, California, include fumarolic activity and associated hydrothermally altered rocks. Pleistocene volcanic rocks associated with the geothermal activity include 38 rhyolite domes occupying a north trending structural and topographic ridge and numerous basaltic cinder cones and lava flows partly surrounding its southern half. In

Jim Combs

1980-01-01

31

Time-Dependent Tomography and Microearthquake Moment Tensors in the Coso Geothermal Area  

NASA Astrophysics Data System (ADS)

The Coso geothermal area, California, has produced hot water and steam for electricity generation for more than a decade. During this time, a permanent network of three-component digital borehole seismometers operated by the U.S. Navy has monitored the abundant microearthquake activity in the producing region. A 14-station portable array of three-component digital instruments has supplemented the Navy network since about September 2003 to improve the monitoring near several wells in which fluid injection/hydrofracturing experiments were planned for enhancing geothermal energy production. This combined network records several thousand microearthquakes each year. We used the data for time-dependent seismic tomography to determine changes in seismic wave-speed structure associated with fluid removal. We also determined high-precision locations and microearthquake mechanisms (moment tensors). Inversions of a 4811-earthquake data set comprising 79,822 P- and S-phase travel times reveal low Vp and Vs wave speeds extending to a maximum depth of about 4 km beneath Coso Basin associated with sedimentary fill in the Coso Wash. A negative Vp/Vs anomaly occurs in the northern and eastern part of the geothermal field at 1 km above sea level, and in the northern and southern parts of the field at sea level. Independent graded inversions for each of the years 1996 - 2004 separately show an irregular strengthening of these anomalies. This progressive reduction in Vp/Vsresults predominately from a progressive relative increase of Vs with respect to Vp. Such an increase can result from processes associated with geothermal operations such as a decrease in fluid pressure and the drying of argillaceous minerals such as illite. We will present moment tensors and high-resolution relative earthquake locations for microearthquakes associated with an injection experiment conducted 22nd Feb - 4th March, 2005 in Well 34-9RD2. This well penetrated a deep zone of high permeability, at which time a burst of microearthquakes occurred, before significant injection work was done.

Julian, B. R.; Foulger, G. R.; Richards-Dinger, K.; Monastero, F.

2005-12-01

32

3D Magnetotelluric characterization of the COSO GeothermalField  

SciTech Connect

Knowledge of the subsurface electrical resistivity/conductivity can contribute to a better understanding of complex hydrothermal systems, typified by Coso geothermal field, through mapping the geometry (bounds and controlling structures) over existing production. Three-dimensional magnetotelluric (MT) inversion is now an emerging technology for characterizing the resistivity structures of complex geothermal systems. The method appears to hold great promise, but histories exploiting truly 3D inversion that demonstrate the advantages that can be gained by acquiring and analyzing MT data in three dimensions are still few in number. This project will address said issue, by applying 3D MT forward modeling and inversion to a MT data set acquired over the Coso geothermal field. The goal of the project is to provide the capability to image large geothermal reservoirs in a single self-consistent model. Initial analysis of the Coso MT data has been carried out using 2D MT imaging technology to construct an initial 3D resistivity model from a series of 2D resistivity images obtained using the inline electric field measurements (Zxy impedance elements) along different measurement transects. This model will be subsequently refined through a 3D inversion process. The initial 3D resistivity model clearly shows the controlling geological structures possibly influencing well production at Coso. The field data however, also show clear three dimensionality below 1 Hz, demonstrating the limitations of 2D resistivity imaging. The 3D MT predicted data arising from this starting model show good correspondence in dominant components of the impedance tensor (Zxy and Zyx) above 1Hz. Below 1 Hz there is significant differences between the field data and the 2D model data.

Newman, Gregory A.; Hoversten, Michael; Gasperikova, Erika; Wannamaker, Philip E.

2005-01-01

33

Microearthquake characterisation of an artificially stimulated hydraulic fracture at the Coso geothermal area, California  

NASA Astrophysics Data System (ADS)

The Coso geothermal area, California, has produced hot water and steam for electricity generation for more than 20 years, during which time intense microearthquake activity has occurred in the area, much of it induced by geothermal production. The seismicity is monitored by a high-quality permanent network of three- component digital borehole seismometers operated by the US Navy and supplemented by a ~ 14-station portable array of surface three-component digital instruments. The purpose of the portable stations is to improve seismic monitoring around wells in which fluid injection/hydrofracturing experiments are conducted. The first injection experiment was conducted in well 34-9RD2, on the East Flank of the Coso geothermal area. This well was re-drilled February - March 2005 with the intention of hydrofracturing it by injecting fluids under pressure. Instead, natural fractures were encountered at about 2,660 m depth. Drilling muds entered the fractures, obviating the need to stimulate the well. These mud losses induced a 50-minute swarm of 44 microearthquakes, with magnitudes in the range -0.3 to 2.6. Most of the largest microearthquakes occurred in the first 2 minutes. Accurate relative relocations and moment tensors for the best-recorded subset reveal fine details of the fracture stimulated. This comprised a fault striking at N 20 deg E and dipping at 75 deg to the WNW, which propagated to the NNE and upward. Co-injection focal mechanisms reveal combined crack- opening and shear motion. Stress release and mode of failure differed between the pre-, co- and post-swarm periods. Some post-swarm events involved cavity collapse, suggesting that some of the cavities opened by the fluid injection closed quickly. Stress and mode of failure had not returned to pre-swarm conditions within 1 month following the injection, posing the question of how long stress perturbations persist following a stimulation experiment. This question may be answered by processing data spanning a longer post-injection period, work that is currently in hand and will be reported in this presentation. We will also report on progress in developing a Graphical User Interface to facilitate deriving moment tensors from microearthquakes using amplitude ratios.

Foulger, G. R.; Julian, B. R.; Monastero, F. C.

2006-12-01

34

Structural interpretation of the Coso geothermal field. Summary report, October 1986-August 1987  

SciTech Connect

The Coso Geothermal Field, located east of the Sierra Nevada at the northern edge of the high Mojave Desert in Southern California, is an excellent example of a structurally controlled geothermal resource.

Austin, C.F.; Moore, J.L.

1987-09-01

35

Clinopyroxene thermobarometry of basalts from the Coso and Big Pine volcanic fields, California  

NASA Astrophysics Data System (ADS)

The Coso and Big Pine volcanic fields of eastern California exhibit different magmatic histories. The Big Pine field erupted only basalt lavas, some of which bear mantle xenoliths, whereas the Coso field erupted both basalt and rhyolite and is a major geothermal resource. These different magmatic products could be explained if Coso basalts stalled in the crust before erupting, providing heat to generate silicic magma, whereas Big Pine basalts erupted directly from mantle depths. Clinopyroxene liquid thermobarometry indicates an average clinopyroxene crystallization depth of 45 km for Big Pine basalts and 19 km for Coso basalts, consistent with this hypothesis. Differences in crustal density, crustal structure, and prior magmatic history may have contributed to the different magmatic processes operating at each field. Our results indicate that the effects of analytical error, crystal zoning, and correlated errors on estimated temperatures and pressures from the thermobarometer are relatively small compared to intersample differences.

Mordick, B. E.; Glazner, A. F.

2006-07-01

36

Physical properties of two core samples from Well 34-9RD2 at the Coso geothermal field, California  

USGS Publications Warehouse

The Coso geothermal field, located along the Eastern California Shear Zone, is composed of fractured granitic rocks above a shallow heat source. Temperatures exceed 640 ?F (~338 ?C) at a depth of less than 10000 feet (3 km). Permeability varies throughout the geothermal field due to the competing processes of alteration and mineral precipitation, acting to reduce the interconnectivity of faults and fractures, and the generation of new fractures through faulting and brecciation. Currently, several hot regions display very low permeability, not conducive to the efficient extraction of heat. Because high rates of seismicity in the field indicate that the area is highly stressed, enhanced permeability can be stimulated by increasing the fluid pressure at depth to induce faulting along the existing network of fractures. Such an Enhanced Geothermal System (EGS), planned for well 46A-19RD, would greatly facilitate the extraction of geothermal fluids from depth by increasing the extent and depth of the fracture network. In order to prepare for and interpret data from such a stimulation experiment, the physical properties and failure behavior of the target rocks must be fully understood. Various diorites and granodiorites are the predominant rock types in the target area of the well, which will be pressurized from 10000 feet measured depth (MD) (3048m MD) to the bottom of the well at 13,000 feet MD (3962 m MD). Because there are no core rocks currently available from well 46A-19RD, we report here on the results of compressive strength, frictional sliding behavior, and elastic measurements of a granodiorite and diorite from another well, 34-9RD2, at the Coso site. Rocks cored from well 34-9RD2 are the deepest samples to date available for testing, and are representative of rocks from the field in general.

Morrow, C.A.; Lockner, D.A.

2006-01-01

37

Three-dimensional seismic velocity models, high-precision earthquake locations and their implications for seismic, tectonic and magmatic settings in the Coso Geothermal Field, California  

NASA Astrophysics Data System (ADS)

The Coso Geothermal Field (CGF) lies at the east of Sierra Nevada and is situated in tectonically active area with the presence of hot spring, rhyolite domes at the surface, strike-slip and normal faulting and frequent seismic activity. In this study, we present our comprehensive analysis of three-dimensional velocity structure, high-precision earthquake relocation and in situ Vp/Vs estimates. We select 1,893 master events among 177,000 events between 1981 and 2011 recorded by the Southern California Seismic Network stations. High-resolution three-dimensional (3-D) Vp and Vp/Vs models in Coso are inverted from the master events with 52,160 P- and 23,688 S-wave first arrivals by using the SIMUL2000 algorithm. The tomographic model reveals slightly high Vp and Vp/Vs in most regions of Coso near the surface compared to the layers at depth of 6 and 12 km, which is consistent with the fact that the Coso area is filled with diorite and minor basalt. The feature of low Vp, low Vs and low Vp/Vs between 6 and 12 km depths underneath the CGF can be related to the porous, gas-filled rock or volatile-rich magma. The low Vp, low Vs and low Vp/Vs structure from the surface to 3 km depth beneath the Indian Wells Valley is consistent with the existence of the 2 km deep sediment strata revealed by the borehole data. The resulting new 3-D velocity model is used to improve the absolute event location accuracy. We then apply waveform cross-correlation, similar event cluster analysis and differential time relocation methods to improve relative event location accuracy with the horizontal and vertical location uncertainties in tens of meters. The relocated seismicity indicates that the brittle-ductile transition depth is as shallow as 5 km underneath the CGF. We also estimate in situ near-source Vp/Vs ratio within each event cluster using differential times from cross-correlation to complement the Vp/Vs model from tomographic inversions, which will help to estimate the volume fraction of magma.

Zhang, Q.; Lin, G.

2012-12-01

38

Hot Sauce Hot Spots  

NSDL National Science Digital Library

In this activity, learners model hot spot island formation, orientation and progression with condiments. Learners squirt a thick condiment sauce on a coarsely woven fabric to model how volcanic island hot spots form.

Muller, Eric

2007-01-01

39

Structural investigations at the Coso geothermal area using remote sensing information, Inyo County, California  

SciTech Connect

Remote sensing studies have been made in and adjacent to the Coso geothermal field using TM FCC satellite imagery, 1:100,000 scale, US Geological Survey orthophotos, 1:24,OOO scale, and proprietary black-and-white photography by California Energy Company, Inc., at various scales including black-and-white positive film transparencies at a scale of 1:6,000. These studies have been made in an attempt to understand the complex geology seen on the surface and to try to improve the method of locating geothermal wells. The tectonic history indicated by remote sensing, gravity, magnetic, refraction and reflection seismic studies indicates structure caused by a period of thrusting and folding followed by local and regional slumping and collapse, which is continuing today. During Sevier/Laramide orogeny, the Sierra Nevada Mountains were thrust eastward over Rose Valley/lndian Wells Valley. Relatively thin granitic/metamorphic plates were folded to form the Coso Range and thrust eastward over Coso Wash. In turn, the Argus Range to the east was thrust eastward over Panamint Valley. As soon as topographic relief, developed by the thrusting, was high enough, the entire area started to collapse, in some cases using the original thrust planes for slumping. The granitic/metamorphic rocks forming the surface of the Coso Range anticline slumped eastward into Coso Wash and westward toward Rose Valley. The Sierra front slumped eastward into Rose Valley/Indian Wells Valley, and the entire range may have had westward on the original thrust faults. The thin basalts on the east side of Coso Wash slumped westward into Coso Wash. Several basaltic eruptions of 3-4 million years ago used the zone between slump blocks as eruption sites. Regional slumping for the entire area toward the southeast is indicated on satellite imagery.

Austin, W.H. (Austin Enterprises, Santa Rose, CA (USA))

1990-05-01

40

Magmatic Evolution of the Coso Geothermal Area, California  

NASA Astrophysics Data System (ADS)

Geothermal energy in the Coso field owes its origin to basaltic magmatism. Volcanism commenced ~3.5 Ma ago, coincident with a widespread Pliocene outburst in eastern California. Although most basalts associated with this event are highly potassic, those at Coso are not. Pliocene volcanic rocks at Coso (erupted between 3.5-2 Ma) range from basalt to rhyodacite, show abundant petrographic evidence for open-system behavior (e.g., quartz xenocrysts in basalts), and have compositions consistent with mixing. In contrast, Pleistocene rocks, erupted <1 Ma ago, comprise a strongly bimodal suite of mildly alkalic basalt and high-silica rhyolite. Pleistocene basalts differ from their Pliocene counterparts in generally having more depleted 87Sr/86Sr and ?Nd values (0.703, +7 vs. 0.704, +4); higher TiO2 and Nb; lower MgO; greater stalling depths in the crust. Pliocene rocks are distinctly arc-like even though they were erupted ~10 Ma after subduction ceased. In contrast, Pleistocene basalts have a distinctly OIB-like geochemical signature, with undepleted high field strength elements and plume-like radiogenic isotope ratios; these characteristics are shared with late Cenozoic basalts across the western U.S. Rare Pleistocene basalts that were erupted from within the footprint of the rhyolite field have notably high TiO2 contents (>3 wt%), similar to basalts from the Columbia River and Snake River Plain fields. Unlike Pliocene rocks, which scatter toward isotopic values of local basement with increasing SiO2, Pleistocene rhyolites generally have high and consistent ?Nd (+1 - +2.5). Producing this signature by AFC processes involving basalt and basement rocks requires remarkably consistent mixing and fractionation at small-volume volcanic centers separated by several km. Alternatively, high ?Nd values in the rhyolites could have been produced by partial melting of Pliocene basalts and andesites, which have very similar Nd isotopic compositions. Increasing ?Nd in silicic rocks as the geothermal production area is approached suggests that the magmatic flux is highest there even though erupted volumes are significantly larger outside the geothermal area. One scenario consistent with the above data is as follows. Post-subduction tectonic events triggered magmatism at 3.5 Ma, tapping fertile, subduction-metasomatized lithospheric mantle. Basalts stalled in and partially melted the mid-crust, generating a mixed-magma series and copious volcanism. Depletion of the mantle source by 2 Ma led to a hiatus in magmatism. A change in basalt chemistry to OIB- affinity in the last 1 Ma suggests a profound change in magma source - likely involving decompression melting of ascending asthenospheric mantle, perhaps related to lithosphere delamination. Injection of such magmas into the lower crust, would have generated rhyolites by remelting of earlier emplaced mafic bodies - imparting a juvenile isotopic signature in the late rhyolites. Precursory Pliocene magmatism is a common feature of other western U.S. geothermal areas, including Twin Peaks, The Geysers, and Long Valley.

Glazner, A. F.; Miller, J. S.; Leeman, W. P.; Johnson, B. R.; Monastero, F. C.

2007-12-01

41

Attenuation and source properties at the Coso Geothermal area, California  

USGS Publications Warehouse

We use a multiple-empirical Green's function method to determine source properties of small (M -0.4 to 1.3) earthquakes and P- and S-wave attenuation at the Coso Geothermal Field, California. Source properties of a previously identified set of clustered events from the Coso geothermal region are first analyzed using an empirical Green's function (EGF) method. Stress-drop values of at least 0.5-1 MPa are inferred for all of the events; in many cases, the corner frequency is outside the usable bandwidth, and the stress drop can only be constrained as being higher than 3 MPa. P- and S-wave stress-drop estimates are identical to the resolution limits of the data. These results are indistinguishable from numerous EGF studies of M 2-5 earthquakes, suggesting a similarity in rupture processes that extends to events that are both tiny and induced, providing further support for Byerlee's Law. Whole-path Q estimates for P and S waves are determined using the multiple-empirical Green's function (MEGF) method of Hough (1997), whereby spectra from clusters of colocated events at a given station are inverted for a single attenuation parameter, ??, with source parameters constrained from EGF analysis. The ?? estimates, which we infer to be resolved to within 0.01 sec or better, exhibit almost as much scatter as a function of hypocentral distance as do values from previous single-spectrum studies for which much higher uncertainties in individual ?? estimates are expected. The variability in ?? estimates determined here therefore suggests real lateral variability in Q structure. Although the ray-path coverage is too sparse to yield a complete three-dimensional attenuation tomographic image, we invert the inferred ?? value for three-dimensional structure using a damped least-squares method, and the results do reveal significant lateral variability in Q structure. The inferred attenuation variability corresponds to the heat-flow variations within the geothermal region. A central low-Q region corresponds well with the central high-heat flow region; additional detailed structure is also suggested.

Hough, S.E.; Lees, J.M.; Monastero, F.

1999-01-01

42

Environment support program for a major geothermal project, Coso, California  

SciTech Connect

The Coso known geothermal resource area, developed by California Energy Company, Inc., has become the fourth largest geothermal development in the world with over 100 production wells completed and 240 MW of power on line. Drilling began in 1983 with the first discovery wells, and project development began in 1985. The need for fast-track permitting became apparent in 1987 with completion of several stepout discovery wells over 3 mi from the known production area. This discovery tripled the size of recoverable reserves and allowed for full development of power sales contracts that would expire in 1990. Project plans had to incorporate a fast-track environmental approval and permitting program which allowed flexibility for changes in drilling locations as geological data became refined with each succeeding well. The 14-mi{sup 2} land position was divided into three separate project areas to reflect joint venture ownership and regulatory jurisdiction. All three areas had to be developed simultaneously. Each of the project areas have significantly different regulatory requirements. Over 300 separate environmental approvals and permits were obtained in less than 3 yr. Permits were issued by the China Lake Naval Weapons Center, the surface manager and a resource owner, the Bureau of Land Management, resource manager; and the Great Basin Unified Air Pollution Control District, the California Water Quality Control Board, and the California Energy Commission. The development and execution of a closely coordinated agency review process, accelerated permitting program, and corporate support program are described.

McClain, D. (California Energy Co., Inc., San Francisco (USA)); McClenahan, L. (MHA, Inc., San Mateo, CA (USA))

1990-05-01

43

Heat flow studies, Coso Geothermal Area, China Lake, California. Technical report  

Microsoft Academic Search

Heat flow studies in the Coso Geothermal Area were conducted at China Lake, California. Temperature measurements were completed in nine of the heat flow boreholes. Temperatures were measured at five meter intervals from the ground surface to the deepest five meter interval. Subsequently, temperatures were remeasured two or three times in each borehole in order to demonstrate that equilibrium thermal

1975-01-01

44

Steady state deformation of the Coso Range, east central California, inferred from satellite radar interferometry  

USGS Publications Warehouse

Observations of deformation from 1992 to 1997 in the southern Coso Range using satellite radar interferometry show deformation rates of up to 35 mm yr-1 in an area ???10 km by 15 km. The deformation is most likely the result of subsidence in an area around the Coso geothermal field. The deformation signal has a short-wavelength component, related to production in the field, and a long-wavelength component, deforming at a constant rate, that may represent a source of deformation deeper than the geothermal reservoir. We have modeled the long-wavelength component of deformation and inferred a deformation source at ???4 km depth. The source depth is near the brittle-ductile transition depth (inferred from seismicity) and ???1.5 km above the top of the rhyolite magma body that was a source for the most recent volcanic eruption in the Coso volcanic field [Manley and Bacon, 2000]. From this evidence and results of other studies in the Coso Range, we interpret the source to be a leaking deep reservoir of magmatic fluids derived from a crystallizing rhyolite magma body.

Wicks, C.W.; Thatcher, W.; Monastero, F.C.; Hasting, M.A.

2001-01-01

45

Hot Science: Hot rocks  

NSDL National Science Digital Library

This site explores two kinds of igneous rock, pumice and granite. Pumice is an example of extrusive igneous rock, while granite is an example of intrusive igneous rock. Intrusive indicates that the magma was forced close to the surface, but then cooled more slowly underneath the surface. The question, "How hot is Lava?" is linked to an explanation of the heat of lava, why it must be sampled when it is very hot, and how the samples are taken.

46

Subsurface Characterization Beneath the Coso Geothermal Field by Ambient Noise Tomography  

NASA Astrophysics Data System (ADS)

The Coso Geothermal Area has been the subject of numerous geophysical studies over the past 30 years. Various seismological techniques have been applied to evaluate the regional stress distribution, velocity and attenuation structure of the subsurface. None of these studies has imaged subsurface shear velocity using surface waves generated either by local micro-earthquakes or by regional or teleseismic earthquakes, nor have any used interferometric methods based on ambient noise. In this study, we apply an interferometic method based on ambient seismic noise aimed at imaging the shallow shear velocity structure beneath the Coso Geothermal Area. Data are from a PASSCAL experiment deployed between 1998 and 2000 and regional broad-band seismometers operated by CalTech. Cross-correlations are performed between each pair of the COSO PASSCAL and CalTech stations for 15 months from March 1999 to May 2000. After compensating for or correcting instrumental irregularities and selecting reliable Rayleigh wave dispersion measurements from the inter-station cross-correlations, we obtain about 300 measurement paths as the basis for surface wave tomography at periods from 3 to 10 sec. Uncertainties of both group and phase velocity measurements are estimated using the variations among the dispersion curves from one-month cross-correlations in different months. The resulting dispersion maps reveal low group and phase velocities in the COSO volcanic field, especially at 3 sec period for group velocities, and high velocities to the east of the COSO volcanic field. The velocity variations are consistent with surface geological features, which encourages future inversion for 3-D shear velocity structure in the top 15 km of the crust.

Ritzwoller, M. H.; Yang, Y.; Levshin, A. L.; Barmin, M. P.; Jones, C. H.

2009-12-01

47

Are obsidian subsources meaningful units of analysis?: temporal and spatial patterning of subsources in the Coso Volcanic Field,  

E-print Network

Are obsidian subsources meaningful units of analysis?: temporal and spatial patterning reserved. Keywords: Obsidian fingerprinting; Intra-source variability; Coso Volcanic Field; California. Obsidian sourcing, or finger- printing, has greatly advanced our understanding and knowledge of obsidian

48

3D Finite Element Analysis of Stress, Second Order Fractures and Fluid-Flow Pathways for the Coso Geothermal Field  

NASA Astrophysics Data System (ADS)

The efficiency of geothermal energy production at the Coso Geothermal Field in eastern California is reliant on the knowledge of fluid flow directions associated with fracture networks. We use 3D finite element analysis to simulate the 3D state of stress of the tectonic setting of the Coso Range within the ECSZ. The modeling is based on a multi-scale approach of the ECSZ and the Coso Range releasing bend setting. The modeling results are calibrated against stress magnitudes and orienations and the received 3D state of stress is used for subsequent anaylsis. The tectonically induced differential stresses are used to infer second order fracture likelihood and orientation. The mean stress ditribution is used to derive possible fluid flow vectors. The results show that the Coso Range and adjacent areas are regions of increased likelihood of second order fracture generation and that 2nd order fracures coincide with clusters of regional seismicity. The mean stress distribution indicates that the geothermal field occurs in a favorable location for fluid through-flow locally derived from the north and west, but more regionally from the Sierra Nevada, and that fluid storage may occur at the southern end of the Coso Wash Fault. Predicted second order structures either support or constrain fluid flow. This indicates the importance of fracture networks for fluid migration in tectonically active regions such as the Coso Range.

Eckert, A.; Connolly, P.

2007-12-01

49

Time lapse gravity monitoring at Coso geothermal field  

NASA Astrophysics Data System (ADS)

An extensive time lapse gravity data set was acquired over the Coso geothermal field near Ridgecrest, California starting in 1987, with the latest data set acquired in 2013. In this thesis I use these gravity data to obtain a better understanding of mass changes occurring within the geothermal field. Geothermal energy is produced by flashing naturally heated ground water into steam which is used to turn turbines. Brine and re-condensed steam are then re-injected into the reservoir. A percentage of the water removed from the system is lost to the process. The time lapse gravity method consists of gravity measurements taken at the same locations over time, capturing snap shots of the changing field. After careful processing, the final data are differenced to extract the change in gravity over time. This change in gravity can then be inverted to recover the change in density and therefore mass over time. The inversion process also produces information on the three dimensional locations of these mass changes. Thirty five gravity data sets were processed and a subsection were inverted with two different starting times, a sixteen point data set collected continuously between 1991 and 2005, and a thirty-eight point data set collected between 1996 and 2005. The maximum change in gravity in the 1991 data group was -350 microGal observed near station CSE2. For the 1996 data group the maximum gravity change observed over the nine year period was -248 microGal. The gravity data were then inverted using the surface inversion method. Three values of density contrast were used, -0.05 g/cm3, -0.10 g/cm3, and -0.20 g/cm3. The starting surface in 1991 was set to 2,500 ft above sea level. The changes in surfaces were then converted to mass changes. The largest total mass change recovered was -1.39x1011 kg. This mass value is of the same order of magnitude as published well production data for the field. Additionally, the gravity data produces a better understanding of the spatial distribution of mass loss. The mass loss is concentrated in one area of the field while others remain somewhat constant.

Woolf, Rachel Vest

50

Crustal stress heterogeneity in the vicinity of a geothermal field: Coso Geothermal Field, CA  

NASA Astrophysics Data System (ADS)

Borehole induced structures seen in image logs from the Coso Geothermal Field, CA record variation in the azimuth of principal stress. Image logs of these structures from five boreholes were analyzed to quantify the stress heterogeneity for three geologically distinct locations: two boreholes within the Coso Geothermal Field (one in an actively produced volume), two on the margin of the Coso Geothermal Field and outside the production area, and a control borehole several tens of kilometers south of the Coso Geothermal Field. Average directions of Shmin and its standard deviation are similar along the eastern portion of the geothermal field at ˜107 +/- 28°; this is distinct from the western portion which has an azimuth of 081 +/- 18° and also distinct from outside the geothermal field where the average azimuth is 092 +/- 47°. These relationships suggest a correlation of stress orientation and heterogeneity with slip on the Coso Wash fault, suggesting that ˜20 years of production has not affected the Shmin.orientation. The slope of power spectrum quantifies the length-scale dependence of stress rotations for the volume of the brittle crust penetrated by each borehole. Spectral analysis was applied to the depth variation of stress direction and it demonstrates that: (1) the data set contains distinct wavelengths of stress rotation, (2) that the relative power of these wavelengths in the total scaling of stress directions demonstrates a fractal distribution and (3) in a manner consistent with earthquakes causing the stress rotations. While the vertically averaged Shmin orientation for the three eastern boreholes varied by as little as 1°, the spectral slopes varied by 0.4 log (deg2 *m)(m) from the inside to the margin unproduced areas of the Coso Geothermal Field. The two boreholes inside the field had spectral slopes within one standard deviation, even though Shmin orientations were not parallel. These results suggest that at the kilometer length scale, the source of stress heterogeneity is dominated by proximity to recent fault slip, whereas the centimeter to meter stress heterogeneity is dominated by earthquake activity.

Blake, Kelly

51

Rock Magnetic and Paleointensity Study of Eastern California's ~83 Ma Golden Bear and Coso Dikes  

NASA Astrophysics Data System (ADS)

Extraordinary intermediate-composition (Kspar +/- quartz andesite porphyry) dikes are coincident with the end of Sierra Nevada magmatism and crop out on both the east and the west sides of Owens Valley, but offset dextrally by >60 km. If this offset represents ancient (possibly Cretaceous) strike-slip partitioning of Pacific-North America plate boundary strain, then at least one of the south- and east-sited Coso dikes might be expected to be paleomagnetically "identical" to its presumed paleo-contiguous, north- and west-sited Golden Bear partner. Accompanying a directional study by Pluhar and colleagues at CSU-Fresno, we are characterizing magnetic mineralogy, fabric, and thermal lability of Coso dikes and the Golden Bear dike. We are also applying the pTRM difference multi-specimen paleointensity technique to these samples, testing for across-Owens Valley correlation.

Feldman, M.; Raub, T. D.

2009-12-01

52

Relationship Between Active Faulting, Strain Transfer, and Relief on the Brittle-Ductile Transition Zone, Coso Range, Eastern California  

NASA Astrophysics Data System (ADS)

The Coso Range is located within a right-releasing stepover between the dextral Airport Lake and Owens Valley fault zones along the southeastern margin of the Sierra Nevada microplate. Upper crustal extension in the stepover region is accommodated by the Coso Wash graben at the southeast end of the stepover region, and by a series of left-stepping, north-northeast-striking, right-normal oblique faults in the northern Coso Range at the northwest end of the stepover region. The upper crustal faults overlie a NW-trending zone in the 5 to 10 km depth range beneath the central and northern Coso Range that is characterized by high heat flow and low P-wave and S-wave velocities. The brittle-ductile transition zone (BDT) is arched upward over the low velocity zone as evidenced by shallowing of the base of seismicity to 4-5 km depth beneath the Coso geothermal field. The positive relief on the BDT may guide or control the down-dip geometry of active faults in the step-over region. South of the geothermal field, the Coso Wash fault dips east, toward the east-dipping flank of the low velocity zone and in the direction that the BDT is deepening away from the zone of highest heat flow. At the latitude of the geothermal field, the traces of active normal faults dip west and they likely terminate against or sole into the BDT as it deepens westward toward Rose Valley. The right-normal faults in the northwestern Coso Range graben similarly sole into or terminate against the elevated BDT above the low velocity zone. The low velocity zone may be acting as a strain guide for the transmission of NW dextral shear across the stepover region. Brittle faulting and seismogenic deformation above the shallow BDT contribute to development of permeability in the geothermal reservoir, and provide pathways for upward circulation of hydrothermal fluids.

Unruh, J. R.; Hauksson, E.

2007-12-01

53

Coso: example of a complex geothermal reservoir. Final report, 1984-1985  

SciTech Connect

The Coso geothermal system has been widely studied and reported by scientists through the past several years, but there is still a considerable divergence of opinion regarding the structural setting, origin, and internal structure of this energy resource. Because of accelerating exploration and development drilling that is taking place, there is a need for a reservoir model that is consistent with the limited geologic facts available regarding the area.

Austin, C.F.; Durbin, W.F.

1985-09-01

54

Structural investigations at the Coso geothermal area using remote sensing information, Inyo County, California  

Microsoft Academic Search

Remote sensing studies have been made in and adjacent to the Coso geothermal field using TM FCC satellite imagery, 1:100,000 scale, US Geological Survey orthophotos, 1:24,OOO scale, and proprietary black-and-white photography by California Energy Company, Inc., at various scales including black-and-white positive film transparencies at a scale of 1:6,000. These studies have been made in an attempt to understand the

Ward H. Austin

1990-01-01

55

36Cl/Cl ratios in geothermal systems: preliminary measurements from the Coso Field  

SciTech Connect

The {sub 36}Cl/Cl isotopic composition of chlorine in geothermal systems can be a useful diagnostic tool in characterizing hydrologic structure, in determining the origins and age of waters within the systems, and in differentiating the sources of chlorine (and other solutes) in the thermal waters. The {sub 36}Cl/Cl values for several geothermal water samples and reservoir host rock samples from the Coso, California geothermal field have been measured for these purposes. The results indicate that most of the chlorine is not derived from the dominant granitoid that host the geothermal system. If the chlorine was originally input into the Coso subsurface through meteoric recharge, that input occurred at least 1-1.25 million years ago. The results suggest that the thermal waters could be connate waters derived from sedimentary formations, presumably underlying and adjacent top the granitic rocks, which have recently migrated into the host rocks. Alternatively, most of the chlorine but not the water, may have recently input into the system from magmatic sources. In either case, the results indicate that most of the chlorine in the thermal waters has existed within the granitoid host rocks for no more than about 100,00-200,00 years. this residence time for the chlorine is similar to residence times suggested by other researchers for chlorine in deep groundwaters of the Mono Basin north of the Coso field.

Nimz, G.J.; Moore, J.N.; Kasameyer, P.W.

1997-07-01

56

Analysis of 3d Magnetotelluric Measurements Over the Coso Geothermal Field  

NASA Astrophysics Data System (ADS)

We have carried out an investigation of the Coso Geothermal field utilizing a dense grid of magnetotelluric (MT) stations plus a single line of contiguous bipole array profiling over the east flank of the field. Motivation for this study is that electrical resistivity/conductivity mapping can contribute to better understanding of enhanced geothermal systems (EGS) by imaging the geometry, bounds and controlling structures in existing production, and by monitoring changes in the underground resistivity properties in the vicinity of injection due to fracture porosity enhancement. Initial analysis of the Coso MT data was carried out using 2D MT imaging technology to construct a starting 3D resistivity model from a series of 2D resistivity images obtained using the inline electric field measurements (Zxy impedance elements) along different measurement transects. This model was then refined through a 3D inversion process. The 3D resisitivity model clearly showed the controlling geological structures influencing well production at Coso and shows correlations with mapped surface features such as faults and regional geoelectric strike. We have also correlated the model with an acoustic and shear velocity model of the field to show that the near-vertical high conductivity (low resistivity) structure on the eastern flank of the producing field is also a zone of increase acoustic velocity and increased Vp/Vs ratio.

Newman, G. A.; Gasperikova, E.; Hoversten, M.

2007-12-01

57

Anomalous shear wave attenuation in the shallow crust beneath the Coso volcanic regionn, California ( USA).  

USGS Publications Warehouse

We use seismograms of local earthquakes to image relative shear wave attenuation structure in the shallow crust beneath the region containing the Coso volcanic-geothermal area of E California. Seismograms of 16 small earthquakes show SV amplitudes which are greatly diminished at some azimuths and takeoff angles, indicating strong lateral variations in S wave attenuation in the area. 3-D images of the relative S wave attenuation structure are obtained from forward modeling and a back projection inversion of the amplitude data. The results indicate regions within a 20 by 30 by 10 km volume of the shallow crust (one shallower than 5 km) that severely attenuate SV waves passing through them. These anomalies lie beneath the Indian Wells Valley, 30 km S of the Coso volcanic field, and are coincident with the epicentral locations of recent earthquake swarms. No anomalous attenuation is seen beneath the Coso volcanic field above about 5 km depth. Geologic relations and the coincidence of anomalously slow P wave velocities suggest that the attenuation anomalies may be related to magmatism along the E Sierra front.-from Authors

Sanders, C.; Ho-Liu, P.; Rinn, D.; Hiroo, Kanamori

1988-01-01

58

Finite Element (FE) Modeling of Structural Influences on Fractures and Fluid Flow in the Eastern California Shear Zone and the Coso Range  

Microsoft Academic Search

Geothermal energy production from the Coso Geothermal field, located in the Eastern California Shear Zone (ECSZ), is reliant on a thorough understanding of the fluid flow network, which is controlled by the distribution and interaction of fractures and permeability. The Coso site is located within a transtensional bend setting that connects two of the major active fault zones in the

A. Eckert; P. Connolly

2006-01-01

59

Pleistocene high-silica rhyolites of the Coso volcanic field, Inyo County, California.  

USGS Publications Warehouse

The high-silica rhyolite domes and lava flows of the bimodal Pleistocene part of the Coso volcanic field provide an example of the early stages of evolution of a silicic magmatic system of substantial size and longevity. Major and trace element compositions are consistent with derivation from somewhat less silicic parental material by liquid state differentiation processes in compositionally and thermally zoned magmatic systems. Seven chemically homogeneous eruptive groups can be distinguished on the basis of trace element and K/Ar data. The oldest two groups are volumetrically minor and geochemically distinct from the younger groups, all five of which appear to have evolved from the same magmatic system. Erupted volume-time relations suggest that small amounts of magma were bled from the top of a silicic reservoir at a nearly constant long-term rate over the last 0.24Ma. The interval of repose between eruptions appears to be proportional to the volume of the preceding eruptive group. This relationship suggests that eruptions take place when some parameter which increases at a constant rate reaches a critical value; this parameter may be extensional strain accumulated in roof rocks. Extension of the lithosphere favors intrusion of basalt into the crust, attendant partial melting, and maintenance of a long-lived silicic magmatic system. The Coso silicic system may contain a few hundred cubic kilometers of magma. The Coso magmatic system may eventually have the potential for producing voluminous pyroclastic eruptions if the safety valve provided by rapid crustal extension becomes inadequate to 1) defuse the system through episodic removal of volatile-rich magma from its top and 2) prohibit migration of the reservoir to a shallow crustal level.-from Authors

Bacon, C.R.; Macdonald, R.; Smith, R.L.; Baedecker, P.A.

1981-01-01

60

Time-dependent seismic tomography of the Coso geothermal area, 1996-2004  

SciTech Connect

Local-earthquake tomographic images were calculated for each of the years 1996 - 2004 using arrival times from the U.S. Navy’s permanent seismometer network at the Coso geothermal area, California. The results show irregular strengthening with time of the wave-speed ratio VP/VS at shallow depths. These changes result predominately from progressive relative increase in VS with respect to VP, and could result from processes associated with geothermal operations such as decrease in fluid pressure and the drying of argillaceous minerals such as illite.

Julian, B.R.; G.R. Foulger; K. Richards-Dinger; F. Monastero

2006-04-01

61

Time-dependent seismic tomography of the Coso geothermal area, 1996-2004  

USGS Publications Warehouse

The permanent 18-station network of three-component digital seismometers at the seismically active Coso geothermal area, California, provides high-quality microearthquake (MEQ) data that are well suited to investigating temporal variations in structure related to processes within the geothermal reservoir. A preliminary study [Julian, et al., 2003; Julian, et al., 2004] comparing data from 1996 and 2003 found significant variations in the ratio of the seismic wave-speeds, Vp/Vs, at shallow depths over this time interval. This report describes results of a more detailed study of each year from 1996 through 2004.

Julian, B.R.; Foulger, G.R.

2005-01-01

62

Magmatic inclusions in rhyolites, contaminated basalts, and compositional zonation beneath the Coso volcanic field, California  

USGS Publications Warehouse

Basaltic lava flows and high-silica rhyolite domes form the Pleistocene part of the Coso volcanic field in southeastern California. The distribution of vents maps the areal zonation inferred for the upper parts of the Coso magmatic system. Subalkalic basalts (<50% SiO2) were erupted well away from the rhyolite field at any given time. Compositional variation among these basalts can be ascribed to crystal fractionation. Erupted volumes of these basalts decrease with increasing differentiation. Mafic lavas containing up to 58% SiO2, erupted adjacent to the rhyolite field, formed by mixing of basaltic and silicic magma. Basaltic magma interacted with crustal rocks to form other SiO2-rich mafic lavas erupted near the Sierra Nevada fault zone. Several rhyolite domes in the Coso volcanic field contain sparse andesitic inclusions (55-61% SiO2). Pillow-like forms, intricate commingling and local diffusive mixing of andesite and rhyolite at contacts, concentric vesicle distribution, and crystal morphologies indicative of undercooling show that inclusions were incorporated in their rhyolitic hosts as blobs of magma. Inclusions were probably dispersed throughout small volumes of rhyolitic magma by convective (mechanical) mixing. Inclusion magma was formed by mixing (hybridization) at the interface between basaltic and rhyolitic magmas that coexisted in vertically zoned igneous systems. Relict phenocrysts and the bulk compositions of inclusions suggest that silicic endmembers were less differentiated than erupted high-silica rhyolite. Changes in inferred endmembers of magma mixtures with time suggest that the steepness of chemical gradients near the silicic/mafic interface in the zoned reservoir may have decreased as the system matured, although a high-silica rhyolitic cap persisted. The Coso example is an extreme case of large thermal and compositional contrast between inclusion and host magmas; lesser differences between intermediate composition magmas and inclusions lead to undercooling phenomena that suggest smaller ??T. Vertical compositional zonation in magma chambers has been documented through study of products of voluminous pyroclastic eruptions. Magmatic inclusions in volcanic rocks provide evidence for compositional zonation and mixing processes in igneous systems when only lava is erupted. ?? 1984 Springer-Verlag.

Bacon, C.R.; Metz, J.

1984-01-01

63

The mechanics of a magma chamber-fault system in trans-tension with application to Coso  

NASA Astrophysics Data System (ADS)

The mechanical interaction between an elliptically shaped magma chamber and a fault subject to transtension is investigated with particular reference to the Coso geothermal field. The geologic setting of the Coso field is interpreted as a releasing bend step-over structure formed by the Airport Lake and Owens Valley dextral strike-slip fault system. The role of the Coso volcano-magmatic center in the development of the "over-step" structure is examined by treating the magma chamber as a liquid inclusion in a viscoelastic crust containing a fault (Airport Lake). The problem is numerically solved using a 2D viscoelastic finite element model with thermally activated viscosity to account for thermal weakening of the rock. The temperature distribution around the magma body is calculated based on a 3D steady-state approach and using the mesh-less numerical method. The fault is modeled as a frictionless contact. The simulated distributions of stress and strain around the inclusion display a rotation caused by the shearing component of the applied transtension. The results indicate that the fault tends to overstep the chamber in a geometric pattern similar to a step-over. There is good correspondence between the computed distributions of the maximum shear stress in the vicinity of the magma chamber and the map of earthquake epicenters at a depth of 7-10 km in Coso.

Simakin, Alexander G.; Ghassemi, Ahmad

2007-12-01

64

Study of Hot-Jupiter atmospheres using infrared photometry  

NASA Astrophysics Data System (ADS)

The study of upper atmospheres of Hot-Jupiters has burgeoned in the past two years. This thesis aims to detect thermal radiation from 3 unique Hot-Jupiters, discovered by the XO team, using the Infrared Array Camera (IRAC) on the Spitzer Space Telescope in order to obtain broadband spectra in the infrared to constrain the upper atmospheric temperature structure of Hot-Jupiters. The infrared spectral energy distributions of 3 Hot-Jupiters XO-1b, XO-2b and XO-3b have revealed a presence of a thermally inverted stratosphere in all 3 of them. Since the 3 XO Hot-Jupiters occupy a wide range of substellar point fluxes ( F p ~ 0.49-4.2 × 10^9 erg cm -2 s -1 ) it allows us to set a threshold bolometric substellar point, flux on the planet above which the intense optical/UV light from the star drives a thermal inversion--a hot stratosphere. Both XO-1b and XO-2h have substellar point fluxes below F p ~ 0.49-4.2 × 10^9 erg cm -2 s -1 and yet their spectral energy distribution points to a thermally inverted hot stratosphere. XO-3b has a high substellar point flux and as predicted, possesses a thermal inversion as well. Puzzlingly the Hot-Jupiter HD-189733b, which is not in our study, has a similar substellar point flux like XO-1b and yet does not have a. hot stratosphere. We thus suggest that other factors can determine the presence of hot stratospheres in Hot-Jupiters: the substellar point UV flux would be a more appropriate measure of planetary insolation than bolometric flux as upper atmospheric absorbers (TiO, VO and sulfur compounds H 2 and HS) absorb in the optical/UV spectrum and furthermore dynamic effects in the atmosphere like equatorial jets and shocks as suggested by 3D global circulation models can induce stratospheres without extra upper atmospheric absorbers. Obtaining day-side spectra of many more Hot-Jupiters with a wide range of substellar point flux either with existing Cold Spitzer observations in all 4 IRAC channels or during the Warm Spitzer mission could shed more light on why some Hot-Jupiters have hot stratospheres and how exactly they arise. The timing centroids of the secondary eclipses of the 3 Hot-Jupiters have been used to refine their orbital eccentricity. The 3-s upper limit for XO-1b is e × cos(o) < 0.0036, where e is eccentricity and o is the argument of the periastron. Similarly we refined the 3-s upper limit on e × cos(o) < 0.012 for XO-2b. We refined the eccentricity of XO-3b using the weighted average of the timing centroids of our secondary eclipse measurements to e = 0.277+ 0.004. Radius-age trajectories suggest that if the age of XO-3b is t = [Special characters omitted.] GYr and assuming solar metallicity, the increased tidal heating rate would require a lowered tidal dissipation parameter Q p [Special characters omitted.] 10 6 . Even in the absence of an accurate parallax measurement the radius-age trajectory of XO-3b seems to imply that at least some amount tidal heating must be responsible for the inflated radius R p = [Special characters omitted.] R Jup of XO-3b.

Machalek, Pavel

65

The Coso geothermal area: A laboratory for advanced MEQ studies for geothermal monitoring  

USGS Publications Warehouse

The permanent 16-station network of three-component digital seismometers at the Coso geothermal area, California, supplemented by 14 temporary instruments deployed in connection with the DOE Enhanced Geothermal Systems (EGS) Project, provides high-quality microearthquake (MEQ) recordings that are well suited to monitoring a producing geothermal area. We are currently using these data to investigate structure and active processes within the geothermal reservoir by applying three advanced methods: a) high-precision MEQ hypocenter location; b) time-dependent tomography; c) complete (moment tensor) MEQ source mechanism determination. Preliminary results to date resolve seismogenic structures in the producing field more clearly than is possible with conventional earthquake-location techniques. A shallow part of the producing field shows clear changes in the ratio of the seismic wave speeds, Vp/V s, between 1996 and 2002, which are probably related to physical changes in the reservoir caused by fluid extraction.

Julian, B.R.; Foulger, G.R.; Richards-Dinger, K.

2004-01-01

66

Detection of Surface Temperature Anomalies in the Coso Geothermal Field Using Thermal Infrared Remote Sensing  

NASA Astrophysics Data System (ADS)

We use thermal infrared (TIR) data from the spaceborne ASTER instrument to detect surface temperature anomalies in the Coso geothermal field in eastern California. The identification of such anomalies in a known geothermal area serves as an incentive to search for similar markers to areas of unknown geothermal potential. We carried out field measurements concurrently with the collection of ASTER images. The field data included reflectance, subsurface and surface temperatures, and radiosonde atmospheric profiles. We apply techniques specifically targeted to correct for thermal artifacts caused by topography, albedo, and thermal inertia. This approach has the potential to reduce data noise and to reveal thermal anomalies which are not distinguishable in the uncorrected imagery. The combination of remote sensing and field data can be used to evaluate the performance of TIR remote sensing as a cost-effective geothermal exploration tool.

Coolbaugh, M.; Eneva, M.; Bjornstad, S.; Combs, J.

2007-12-01

67

Residence, resorption and recycling of zircons in Devils Kitchen rhyolite, Coso Volcanic Field, California  

USGS Publications Warehouse

Zircons from the Devils Kitchen rhyolite in the Pleistocene Coso Volcanic field, California have been analyzed by in situ Pb/U ion microprobe (SHRIMP-RG) and by detailed cathodoluminescence imaging. The zircons yield common-Pb-corrected and disequilibrium-corrected 206Pb/238U ages that predate a previously reported K-Ar sanidine age by up to 200 kyr, and the range of ages exhibited by the zircons is also approximately 200 kyr. Cathodoluminescence imaging indicates that zircons formed in contrasting environments. Most zircons are euhedral, and a majority of the zircons are weakly zoned, but many also have anhedral, embayed cores, with euhedral overgrowths and multiple internal surfaces that are truncated by later crystal zones. Concentrations of U and Th vary by two orders of magnitude within the zircon population, and by 10-20 times between zones within some zircon crystals, indicating that zircons were transferred between contrasting chemical environments. A zircon saturation temperature of ???750??C overlaps within error a previously reported phenocryst equilibration temperature of 740 ?? 25??C. Textures in zircons indicative of repeated dissolution and subsequent regrowth are probably caused by punctuated heating by mafic magma input into rhyolite. The overall span of ages and large variation in U and Th concentrations, combined with calculated zircon saturation temperatures and resorption times, are most compatible with crystallization in magma bodies that were emplaced piecemeal in the crust at Coso over 200 kyr prior to eruption, and that were periodically rejuvenated or melted by subsequent basaltic injections. ?? Oxford University Press 2004; all rights reserved.

Miller, J.S.; Wooden, J.L.

2004-01-01

68

Deformation of poorly consolidated sediment during shallow emplacement of a basalt sill, Coso Range, California  

USGS Publications Warehouse

A 150-m-long, wedge-shaped unit of folded and faulted marly siltstone crops out between undeformed sedimentary rocks on the north flank of the Coso Range, California. The several-meter-thick blunt end of this wedge abuts the north margin of a basaltic sill of comparable thickness. Chaotically deformed siltstone crops out locally at the margin of this sill, and at one locality breccia pipes about one meter in diameter crosscut the sill. The sill extends about 1 km south up the paleoslope, where it merges through continuous outcrop with a lava flow that in turn extends 1.4 km to a vent area marked by more than 100 m of agglutinate and scoria. Apparently, lava extruded at this vent flowed onto unconsolidated sediments, burrowed into them, and fed a sill at about 40 m depth within the sedimentary sequence. The sill initially propagated by wedging between sedimentary beds, but eventually began to push some beds ahead of itself, forming a remarkable train of folds in the process. The sediments apparently were wet at the time of sill emplacement, because hydrothermal alteration is common near the contact between the two rock types and because the breccia pipes that crosscut the sill apparently resulted from phreatic explosions of pore water heated at the base of the cooling sill. Comparison of deformation of the host material at the Coso locality with that reportedly caused by emplacement of sills elsewhere indicates that the character of deformation differs greatly among the various localities. The specific response of host material depends upon such parameters as initial properties of magma and host material, rate of sill growth and attendant rate of strain of host material, and depth of sill emplacement. Some properties may change considerably during an intrusive-deformational episode, thus complicating accurate reconstruction of such an event. ?? 1986 Springer-Verlag.

Duffield, W.A.; Bacon, C.R.; Delaney, P.T.

1986-01-01

69

Simultaneous Clockwise and Counterclockwise Rotation Along the Eastern California Shear Zone at the Coso Range, California  

NASA Astrophysics Data System (ADS)

The Coso Range, California lies in a releasing step-over of the westernmost strand of the dextral Eastern California Shear Zone (ECSZ). Previous paleomagnetic studies on c.a. 3 Ma lavas of Wild Horse Mesa, within the Coso Range, demonstrate small-magntiude (12.0°±4.6°) clockwise vertical-axis rotations since emplacement of these rocks. Seismogenic, slickenline, and GPS strain data in the same region indicate a present-day rotation rate consistent with lava paleomagnetism results. However, paleomagnetism of lake beds of the White Hills, south of Wild Horse Mesa, yields a (reversed-polarity) mean direction of declination = 171.8°, inclination = -27.8°, ? = 12.3, and ?95 = 7.5° for n = 34 samples. Thus, White Hills have rotated counterclockwise 8.2°±8.2° since the sediments were deposited around 1 Ma. Although not significant at 95% confidence, this rotation is significant at any lesser confidence level and therefore indicates counterclockwise rotation. The opposite sense of rotation between White Hills and Wild Horse Mesa is understandable by the differing fault orientation and deformation styles between the two locales. The White Hills are an anticline within the larger-scale releasing bend of the ECSZ. Faults in the White Hills are generally oriented north-south to northwest-southeast. On the other hand the Wild Horse Mesa forms a transtentional basin with widespread north-south to northeast-southwest oriented normal faults. These differing fault orientations, probably intimately related to the local transpression and transtension within the two areas, respectively, results in simultaneous rotation of opposite sense due to an invariant far-field strain.

Pluhar, C. J.; Coe, R. S.; Monastero, F. C.

2005-12-01

70

Crustal structure determined from ambient noise tomography near the magmatic centers of the Coso region, southeastern California  

NASA Astrophysics Data System (ADS)

We apply seismic ambient noise tomography to image and investigate the shallow shear velocity structure beneath the Coso geothermal field and surrounding areas. Data from a PASSCAL experiment operated within the Coso geothermal field between 1998 and 2000 and surrounding broadband stations from the Southern California Seismic Network are acquired and processed. Daily cross correlations of ambient noise between all pairs of stations that overlapped in time of deployment were calculated and then stacked over the duration of deployment. Phase velocities of Rayleigh waves between 3 and 10 s periods are measured from the resulting cross correlations. Depending on the period, between about 300 and 600 reliable phase velocity measurements are inverted for phase velocity maps from 3 to 10 s periods, which in turn are inverted for a 3-D shear velocity model beneath the region. The resulting 3-D model reveals features throughout the region that correlate with surface geology. Beneath the Coso geothermal area shear velocities are generally depressed, a prominent low-velocity anomaly is resolved clearly within the top 2 km, no significant anomaly is seen below about 14 km depth, and a weakly resolved anomaly is observed between 6 and 12 km depth. The anomaly in the top 2 km probably results from geothermal alteration in the shallow subsurface, no magmatic body is imaged beneath 14 km depth, but the shear velocity anomaly between 6 and 12 km may be attributable to partial melt. The thickness and amplitude of the magma body trade off in the inversion and are ill determined. Low velocities in the regions surrounding Coso at depths near 7 km underlie areas with Miocene to recent volcanism, suggesting that some magmatic processing of the crust could be focused near this depth.

Yang, Yingjie; Ritzwoller, Michael H.; Jones, Craig H.

2011-02-01

71

Hot Canyon  

SciTech Connect

This historical film footage, originally produced in the early 1950s as part of a series by WOI-TV, shows atomic research at Ames Laboratory. The work was conducted in a special area of the Laboratory known as the "Hot Canyon."

None

2012-06-18

72

Hot Canyon  

SciTech Connect

This historical film footage, originally produced in the early 1950s as part of a series by WOI-TV, shows atomic research at Ames Laboratory. The work was conducted in a special area of the Laboratory known as the "Hot Canyon."

None

2012-01-01

73

Hot Ice  

Microsoft Academic Search

THAT the experiments of Dr. Carnelley on hot ice have excited much interest is not to be wondered at. His statement, however, that ice could be raised to a temperature of 180° without melting was so amazing that many a one could not accept it without repeating the experiments. Soon after the first short notice of Dr. Carnelley appeared in

C. J. E. Brutel de La Rivière; A. van Hasselt

1881-01-01

74

Hot Ice  

Microsoft Academic Search

As my name has been mentioned in NATURE in connection with Dr. Carnelley's experiments on hot ice it may possibly be convenient if I describe the experiments in which I have failed to raise the temperature of ice and camphor above their fusing-points when they are heated in vacuo.

Herbert McLeod

1881-01-01

75

Hot Ice  

Microsoft Academic Search

I VENTURE, in referring to Dr. Lodge's letter of this week, to put before your readers the meaning of the remarks made on Dr. Carnelley's experiment at the Chemical Society by Prof. Ayrton, who is now away from England. I understood him to say that as Dr. Carnelley's hot ice is obviously in a condition which cannot be represented within

John Perry; A. VAN HASSELT

1881-01-01

76

Hot Ice  

Microsoft Academic Search

BEING a reader of NATURE, I have become quite interested in Mr. Thos. Carnelley's experiments with hot ice. Although Mr. Carnelley's experiments would seem to be sufficiently accurate to prove that the ice was in a heated condition, I would still like to offer an additional method to heat the ice, and also a method to test for heat in

George B. Richmond

1881-01-01

77

HOT AIR  

NSDL National Science Digital Library

HOT AIR -- The graphical home page of THE ANNALS OF IMPROBABLE RESEARCH FROM MIT provides a different look at scientific research. Check out a schedule of AIR events, an art gallery, and SharewAIR--an interactive and up-to-the-minute moderated forum.

78

Fault rock mineralogy and fluid flow in the Coso Geothermal Field, CA  

NASA Astrophysics Data System (ADS)

The minerals that comprise fault rock, their grain shapes, and packing geometry are important controls on fault zone properties such as permeability, frictional strength, and slip behavior. In this study we examine the role of mineralogy and deformation microstructures on fluid flow in a fault-hosted, fracture-dominated geothermal system contained in granitic rocks in the Coso Geothermal Field, CA. Initial examination of the mineralogy and microstructure of fault rock obtained from core and surface outcrops reveals three fault rock types. (1) Fault rock consisting of kaolinite and amorphous silica that contains large connected pores, dilatant brittle fractures, and dissolution textures. (2) Fault rock consisting of foliated layers of chlorite and illite-smectite separated by slip surfaces. (3) Fault rock consisting of poorly sorted angular grains, characterized by large variations in grain packing (pore size), and crack-seal textures. These different fault rocks are respectively associated with a high permeability upper boiling zone for the geothermal system, a conductively heated "caprock" at moderate to shallow depth associated with low permeability, and a deeper convectively heated region associated with enhanced permeability. Outcrop and hand-sample scale mapping, XRD analysis, and SEM secondary electron images of fault gouge and slip surfaces at different stages of development (estimated shear strain) are used to investigate the processes responsible for the development and physical properties of these distinct fault rocks. In each type of fault rock, mineral dissolution and re-precipitation in conjunction with the amount and geometry of porosity changes induced by dilation or compaction are the key controls on fault rock development. In addition, at the contacts between slip surfaces, abrasion and resulting comminution appear to influence grain size, sorting, and packing. Macroscopically, we expect the frictional strength of these characteristic fault rocks to differ because the processes that accommodate deformation depend strongly on mineralogy. Frictional strength of quartz-dominated fault rocks in the near surface and in the reservoir should be greater (~0.6) than that in the clay-dominated cap rock (~0.2-0.4). Similarly, permeability should be much lower in foliated clay-rich fault rocks than in quartz-rich fault rocks as evidenced by larger, more connected pores imaged in quartz-rich gouge. Mineral stability is a function of loading, strain rate, temperature, and fluid flow conditions. Which minerals form, and the rates at which they grow is also a key element in determining variations in the magnitude and anisotropy of fault zone properties at Coso. Consequently, we suggest that the development of fault-zone properties depends on the feedback between deformation, resulting changes in permeability, and large-scale fluid flow and the leading to dissolution/precipitation of minerals in the fault rock and adjacent host rock. The implication for Coso is that chemical alteration of otherwise low-porosity crystalline rocks appears to determine the distribution and temporal evolution of permeability in the actively deforming fracture network at small to moderate scales as well as along major, reservoir-penetrating fault zones.

Davatzes, N. C.; Hickman, S. H.

2005-12-01

79

Integrated mineralogical and fluid inclusion study of the Coso geothermal system  

SciTech Connect

Coso is one of several high-temperature geothermal systems on the margins of the Basin and Range province that is associated with recent volcanic activity. This system, which is developed entirely in fractured granitic and metamorphic rocks, consists of a well-defined thermal plume that originates in the southern part of the field and then flows upward and laterally to the north. Fluid inclusion homogenization temperatures and salinities demonstrate that cool, low salinity ground waters were present when the thermal plume was emplaced. Dilution of the thermal waters occurred above and below the plume producing strong gradients in their compositions. In response to heating and mixing, clays and carbonate minerals precipitated, sealing the fractures along the margins of the reservoir and strongly influencing its geometry. The alteration mineralogy varies systematically with depth and temperature. Based on the clay mineralogy, three zones can be recognized: the smectite zone, the illite-smectite zone, and the illite zone. The smectite zone thickens from the north to south and is characterized by smectite, kaolin, stilbite and a variety of carbonate minerals. The illite-smectite zone contains mixed-layer clays and also thickens to the south. The deepest zone (the illite zone) contains illite, chlorite, epidote, and wairakite. Quartz and calcite veins occur in all three zones. Comparison of mineral and fluid inclusion based temperatures demonstrates that cooling has occurred along the margins of the thermal system but that the interior of the system is still undergoing heating.

Lutz, S.J.; Moore, J.N. [Univ. of Utah, Salt Lake City, UT (United States); Copp, J.F. [California Energy Company, Ridgecrest, CA (United States)

1996-12-31

80

Integrated mineralogical and fluid inclusion study of the Coso geothermal systems, California  

SciTech Connect

Coso is one of several high-temperature geothermal systems on the margins of the Basin and Range province that is associated with recent volcanic activity. This system, which is developed entirely in fractured granitic and metamorphic rocks, consists of a well-defined thermal plume that originates in the southern part of the field and then flows upward and laterally to the north. Fluid inclusion homogenization temperatures and salinities demonstrate that cool, low salinity ground waters were present when the thermal plume was emplaced. Dilution of the thermal waters occurred above and below the plume producing strong gradients in their compositions. In response to heating and mixing, clays and carbonate minerals precipitated, sealing the fractures along the margins of the reservoir and strongly influencing its geometry. The alteration mineralogy varies systematically with depth and temperature. Based on the clay mineralogy, three zones can be recognized: the smectite zone, the illite-smectite zone, and the illite zone. The smectite zone thickens from the north to south and is characterized by smectite, kaolin, stilbite and a variety of carbonate minerals. The illite-smectite zone contains mixed-layer clays and also thickens to the south. The deepest zone (the illite zone) contains illite, chlorite, epidote, and wairakite. Quartz and calcite veins occur in all three zones. Comparison of mineral and fluid inclusion based temperatures demonstrates that cooling has occurred along the margins of the thermal system but that the interior of the system is still undergoing heating.

Lutz, Susan J.; Moore, Joseph N.; Copp, John F.

1996-01-24

81

Dynamic triggering of microearthquakes in the Long Valley Caldera and Coso Geothermal Field  

NASA Astrophysics Data System (ADS)

Recent studies have shown that microearthquakes can be dynamically triggered by the passing of surface waves from regional and teleseismic events. However, the underlying physical mechanisms and the necessary conditions that favor dynamic triggering are still in debate. Here we conduct a systematic search of dynamically triggered microearthquakes around the Long Valley Caldera (LVC) and Coso Geothermal Field (CGF) in California. In each region, we select distant mainshocks in 1999-2010 with M>=7.5 over 1000 km away, or M>=5.5 between 100-2500 km. Next, we apply 2-8 or 2-16 Hz band-pass-filtered data to the three-component seismograms recorded at each region, and identify triggered events as high-frequency seismic energy during large-amplitude surface waves of regional and teleseismic events. We calculate the beta statistic values based on events listed in the local earthquake catalogs and hand-picked events from the envelope functions, and verify that the triggering is statistically significant. Based on this simple procedure, we have identified many distant events that have triggered activity in both regions, including the recent 08/03/2009 and 04/04/2010 Baja California earthquakes at regional distances, and the 02/27/2010 Chile earthquake at teleseismic distances. Our next steps are to examine the dynamic triggering thresholds in each region, and to understand the triggering potential in terms of frequency, amplitude, incident angle, and type of surface waves.

Aiken, C.; Peng, Z.; Wu, C.

2010-12-01

82

Rhyolite thermobarometry and the shallowing of the magma reservoir, Coso volcanic field, California  

USGS Publications Warehouse

The compositionally bimodal Pleistocene Coso volcanic field is located at the western margin of the Basin and Range province ~ 60 km north of the Garlock fault. Thirty-nine nearly aphyric high-silica rhyolite domes were emplaced in the past million years: one at 1 Ma from a transient magma reservoir, one at ~ 0.6 Ma, and the rest since ~ 0.3 Ma. Over the past 0.6 My, the depth from which the rhyolites erupted has decreased and their temperatures have become slightly higher. Pre-eruptive conditions of the rhyolite magmas, calculated from phenocryst compositions using the two-oxide thermometer and the Al-in-hornblende barometer, ranged from 740??C and 270 MPa (2.7 kbar; ~ 10 km depth) for the ~ 0.6 Ma magma, to 770??C and 140 MPa (1.4 kbar; ~ 5.5 km) for the youngest (~ 0.04 Ma) magma. Results are consistent with either a single rhyolitic reservoir moving upward through the crust, or a series of successively shallower reservoirs. As the reservoir has become closer to the surface, eruptions have become both more frequent and more voluminous.

Manley, C.R.; Bacon, C.R.

2000-01-01

83

Finite Element (FE) Modeling of Structural Influences on Fractures and Fluid Flow in the Eastern California Shear Zone and the Coso Range  

NASA Astrophysics Data System (ADS)

Geothermal energy production from the Coso Geothermal field, located in the Eastern California Shear Zone (ECSZ), is reliant on a thorough understanding of the fluid flow network, which is controlled by the distribution and interaction of fractures and permeability. The Coso site is located within a transtensional bend setting that connects two of the major active fault zones in the ECSZ, the Owens Valley Fault Zone and the Airport Lake Fault Zone. This study uses 3D finite element analysis (FEA) to model the in-situ stress field of the ECSZ and the Coso Range. We use a multi-scale approach to assess the most appropriate set of loading conditions. Two models, one for the ECSZ and a smaller one for the Coso Range will be used to analyse the stress data. After iteration of the best possible FE model results fracture networks and fluid flow characteristics will be derived. In order to achieve the most appropriate set of loading conditions for the Coso Range scale model, it was necessary to model the whole northern part of the ECSZ, including regional tectonic influences such as the Sierra Nevada block displacement and Basin and Range extension. These regional tectonic influences are the most important sources for understanding the local transtensional deformation in the Coso Range. After calibration of the modelling results against stress orientations, GPS vectors and magnitudes, the most reliable set of nodal displacements has been applied as loading conditions for the Coso scale model. It was found that the large difference in topography between different areas of the modelled region had a very significant impact on the in-situ stress and strain estimates obtained. After iteration of the loading conditions use to mimic regional tectonics, a reasonable fit to the in-situ data was obtained. The 3D model of the Coso bend setting is based on analogue sandbox models, which provide a good fit of the regional fault distribution and geometry. After application of the most appropriate loading conditions from the regional model to the Coso bend model the resulting stress field is used to analyse fracture networks and fluid paths. Of special interest is the likelihood of second order fracture generation or reactivation as well as the orientation of the fractures. The virtually generated/reactivated fracture sets are calibrated against second order fracture sets in the analogue sandbox model. The resulting mean stress distribution is used to evaluate possible fluid pathways. Representing the isotropic part of the stress tensor, the mean stress can be considered as pressure and hence the mean stress gradient indicates the direction of possible flow. In combination with the derived second order fracture networks it is possible to derive flow patterns for the Coso Range and the implications for the Coso Geothermal Field.

Eckert, A.; Connolly, P.

2006-12-01

84

Distribution of Quaternary rhyolite domes of the Coso Range, California: implications for extent of the geothermal anomaly.  

USGS Publications Warehouse

38 separate domes and flows of phenocryst-poor, high-silica rhyolite of similar major element chemical composition were erupted over the past 1My from vents arranged in a crudely S-shaped array atop a granitic horst in the Coso Range, California. Most of the extrusions are probably less than about 0.3My old. The central part of the rhyolite field is characterized by high heat flow, low apparent resistivity, and substantial fumarolic activity indicative of an active geothermal system. -from Authors

Bacon, C.R.; Duffield, W.A.

1980-01-01

85

Hot tub folliculitis  

MedlinePLUS

Hot tub folliculitis is an infection of the skin around the lower part of the hair shaft ( ... Hot tub folliculitis is caused by the bacteria Pseudomonas aeruginosa . This form of bacteria survives in hot ...

86

Stress, faulting and fluid flow in the Coso Geothermal Field, CA  

NASA Astrophysics Data System (ADS)

We integrate new geologic mapping and new in situ measurements of stress orientations and magnitudes from studies of wells within and on the flanks of the geothermal system with existing data sets to refine a geomechanical model for the Coso geothermal field. Stress orientations (averaged from several hundred to thousand meters of vertical borehole data) in wells across the field are fairly uniform and are consistent with focal mechanism inversions of earthquake clusters for stress and incremental strain. Active faults trending NNW-SSE to NNE-SSW are well oriented for normal slip in the current stress field, where the mean least principal horizontal compressive stress, Shmin, orientation is 108° ± 24º in a transitional strike-slip to normal faulting stress regime. These structures bound regions of intense micro-seismicity and are complexly associated with surface hydrothermal activity. WNW-ESE trending faults are also associated with distinct regions of enhanced seismicity but are only associated with surface hydrothermal activity where they intersect more northerly trending normal faults. These faults show no evidence for Quaternary slip at the surface and are poorly oriented in the modern stress field. These results together with stress magnitudes measured in the East Flank of the field suggest that the most productive portions of the Coso geothermal field are in high deviatoric stress environments conducive to normal faulting. Recent earthquake relocations and incremental strain inversions map areas of extensional strain located over the southern part of the Main Field and reaching east and north into the East Flank consistent with our borehole analyses. The resulting relatively low mean stress is conducive to dilation and increased permeability accompanying fault slip and coincides with the hottest areas in the geothermal field. Similar regions of locally reduced mean stress might arise from mechanical interaction during slip on intersecting fault segments and account for related surface hydrothermal activity. This interpretation is also consistent with local GPS- and InSAR-based surface displacement vectors which indicate subsidence above the Main Field and East Flank. At reservoir depth, preliminary results from borehole image, temperature, and mud log analyses indicate that fluid flow in the geothermal field is concentrated in the densely fractured damage zones of large faults that are well oriented for slip. In contrast, the cores of these faults appear to function as hydrologic barriers and separate regions of distinct fluid inclusion chemistry and temperature gradient. In addition, significant horizontal principal stress rotations are recorded by drilling-induced structures in borehole image logs. These variations in the azimuth of induced structures indicate local stress heterogeneity induced by active fault slip and are consistent with the high rates of seismicity observed in the geothermal field which might impact damage zone behavior. In the regions between large faults, distributed fracture networks appear to play only a minor role in transferring fluids despite relatively high fracture density that include some fractures well-oriented for slip. This geomechanical model provides a first step in studying the mechanical interactions and permeability of fault zones, their natural evolution, and their response to engineered stimulation. In addition, this model is a critical element of the stimulation strategy that will be applied to Enhanced Geothermal Systems (EGS) well 46A-19RD in the southwest portion of the geothermal field.

Davatzes, N. C.; Hickman, S.

2006-12-01

87

Time-dependent seismic tomography and its application to the Coso geothermal area, 1996-2006  

SciTech Connect

Measurements of temporal changes in Earth structure are commonly determined using localearthquake tomography computer programs that invert multiple seismic-wave arrival time data sets separately and assume that any differences in the structural results arise from real temporal variations. This assumption is dangerous because the results of repeated tomography experiments would differ even if the structure did not change, simply because of variation in the seismic ray distribution caused by the natural variation in earthquake locations. Even if the source locations did not change (if only explosion data were used, for example), derived structures would inevitably differ because of observational errors. A better approach is to invert multiple data sets simultaneously, which makes it possible to determine what changes are truly required by the data. This problem is similar to that of seeking models consistent with initial assumptions, and techniques similar to the “damped least squares” method can solve it. We have developed a computer program, dtomo, that inverts multiple epochs of arrival-time measurements to determine hypocentral parameters and structural changes between epochs. We shall apply this program to data from the seismically active Coso geothermal area, California, in the near future. The permanent network operated there by the US Navy, supplemented by temporary stations, has provided excellent earthquake arrival-time data covering a span of more than a decade. Furthermore, structural change is expected in the area as a result of geothermal exploitation of the resource. We have studied the period 1996 through 2006. Our results to date using the traditional method show, for a 2-km horizontal grid spacing, an irregular strengthening with time of a negative VP/VS anomaly in the upper ~ 2 km of the reservoir. This progressive reduction in VP/VS results predominately from an increase of VS with respect to VP. Such a change is expected to result from effects of geothermal operations such as decreasing fluid pressure and the drying of argillaceous minerals such as illite.

Julian, B.R.; G.R. Foulger; F. Monastero

2008-04-01

88

Time-dependent Seismic Tomography of the Coso Geothermal Area, 1996-2006  

NASA Astrophysics Data System (ADS)

Measurements of temporal changes in Earth structure are commonly determined using local earthquake tomography computer programs that invert multiple seismic-wave arrival time data sets separately and assume that any differences in the structural results arise from real temporal variations. Such an assumption is dangerous because the results of repeated tomography experiments would differ even if the structure did not change, simply because of variation in the seismic ray distribution caused by the natural variation in earthquake locations. Even if the source locations did not change (if only explosion data were used, for example), derived structures would inevitably differ because of observational errors. A much better approach is to invert multiple data sets simultaneously, which makes it possible to determine what changes are truly required by the data. This problem is similar to that of seeking models consistent with initial assumptions, and methods similar to "damped least squares" can solve it. We are developing such a program, dtomo. This program inverts multiple epochs of arrival-time measurements for hypocentral parameters and structural change in the inter-epoch period. We are applying this work to data from the seismically active Coso geothermal area, California. The permanent network operated there by the US Navy, supplemented by temporary stations, provides excellent earthquake arrival-time data. Furthermore, structural change is expected in the area as a result of geothermal exploitation of the resource. We have studied the period 1996 through 2006. Our results show, for a 2-km horizontal grid spacing, an irregular strengthening with time of a negative Vp/Vs anomaly in approximately the upper 2 km of the reservoir. This progressive reduction in Vp/Vs results predominately from a increase of Vs with respect to Vp. Such a change is expected to result from effects of geothermal operations such as decreasing fluid pressure and the drying of argillaceous minerals such as illite.

Foulger, G. R.; Julian, B. R.; Monastero, F. C.

2007-12-01

89

Seismic Characterisation of Hydraulic Stimulation Tests at the Coso Geothermal Area, California  

NASA Astrophysics Data System (ADS)

We studied microearthquakes before, during and after fluid injection tests at the Coso geothermal area, California, to map the fractures formed, determine the mode and sense of failure, and characterize the stress cycle associated with injection. Our approach is based on joint interpretation of high-resolution relative earthquake relocations and full earthquake moment tensors. We developed advanced computer programs for this work, which include combining waveform cross-correlation with relative relocation methods, and rigorously assessing the confidence regions for moment tensors derived using linear-programming methods. Using a high-quality permanent network of three-component digital borehole seismometers operated by the US Navy, supplemented by 14 portable three-component digital instruments installed at the surface, we analysed several months of data spanning injection experiments in well 34A-9 in 2004, well 34-9RD2 in 2005, and pre-injection earthquakes near well 46A-19RD. In the case of injection into well 34A-9, the co-injection earthquakes were more numerous, smaller, more explosive and had more horizontal motion, compared with the background earthquakes. Injection modulated the stress orientation in the activated volume for at least two months after injection ceased. In the case of well 34-9RD2, the injection produced spatially coherent seismicity different from the scattered background activity that occurs continuously there. The relocated hypocenters reveal the dimensions and orientation of a well-defined planar structure, 700 m long and 600 m high in the depth range 0.8 to 1.4 km below sea level, striking N 20 degrees E and dipping 75 degrees to the WNW. The moment tensors show that it represented a mode I (opening) crack. The seismicity rate and stress state in the neighborhood of the bottom of the well did not return to its background state for at least two months following the injection.

Julian, B. R.; Foulger, G. R.; Monastero, F. C.

2007-12-01

90

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 92, NO. B1, PAGES 393-405, JANUARY 10, 1987 P Wave Velocity Variations in the Coso Region, California,  

E-print Network

the Long Valley caldera of eastern California. They identify areas of low P wave velocity with dimensionsof of southeasternCalifornia in order to spatially locate any upper crustal velocity anomalies.Like Long Valley velocity variations in the Indian Wells Valley-Coso region of southeasternCalifornia. The residuals

Clayton, Robert W.

91

Accessory mineral U-Th-Pb ages and 40Ar/39Ar eruption chronology, and their bearing on rhyolitic magma evolution in the Pleistocene Coso volcanic field, California  

NASA Astrophysics Data System (ADS)

We determined Ar/Ar eruption ages of eight extrusions from the Pleistocene Coso volcanic field, a long-lived series of small volume rhyolitic domes in eastern California. Combined with ion-microprobe dating of crystal ages of zircon and allanite from these lavas and from granophyre geothermal well cuttings, we were able to track the range of magma-production rates over the past 650 ka at Coso. In ?230 ka rhyolites we find no evidence of protracted magma residence or recycled zircon (or allanite) from Pleistocene predecessors. A significant subset of zircon in the ~85 ka rhyolites yielded ages between ~100 and 200 Ma, requiring that generation of at least some rhyolites involves material from Mesozoic basement. Similar zircon xenocrysts are found in an ~200 ka granophyre. The new age constraints imply that magma evolution at Coso can occur rapidly as demonstrated by significant changes in rhyolite composition over short time intervals (?10’s to 100’s ka). In conjunction with radioisotopic age constraints from other young silicic volcanic fields, dating of Coso rhyolites highlights the fact that at least some (and often the more voluminous) rhyolites are produced relatively rapidly, but that many small-volume rhyolites likely represent separation from long-lived mushy magma bodies.

Simon, Justin I.; Vazquez, Jorge A.; Renne, Paul R.; Schmitt, Axel K.; Bacon, Charles R.; Reid, Mary R.

2009-10-01

92

High Precision Ar/Ar Ages of Coso Volcanic Field Rhyolites: A Requirement for Constraining Eruption and Subvolcanic Time Scales  

NASA Astrophysics Data System (ADS)

Study of the extended volcanic history and petrology at Coso Volcanic Field, CA has led to fundamental ideas related to silicic magma evolution and eruption prediction. Unfortunately, tests of these and related models for the time scales of subvolcanic processes at Coso are limited because relatively few modern geochronological constraints have been published. For example, tighter age constraints are needed to test the veracity of the volume-age "time-prediction" model of Bacon (1982) wherein the next eruption can be predicted reasonably well from a long-term eruption rate that simply considers the total volume of Coso rhyolites over an appropriate time span. At Coso, reported eruption events are mean ages comprising K-Ar ± hydration rind glass ages grouped by rock chemical similarities. Here we present new Ar/Ar ages for seven Pleistocene domes from groups 4, 6, and 7. Sanidine and anorthoclase were separated from nearly aphyric obsidian and pumiceous glasses. Total fusion and step-heating feldspar and glass analyses were performed. Ar/Ar spectra derived from laser step-heating of samples from previously dated domes show that excess 40Ar contamination likely biased some K-Ar results. Modern Ar/Ar analyses of the studied rhyolites with disturbed model (i.e., assuming atmospheric initial Ar) ages, but well-defined Ar isochrons still provide accurate eruption ages. In detail, a 229 ±6 ka (2 se) age is determined for the most northern dome, which is ~60 ka older than one reported K-Ar date and the nominal age for Group 4 rhyolites and ~150-370 ka younger than four other reported K-Ar dates. Based on pre-eruption zircon ages from other magma centers, the inaccuracies and magnitude of these age shifts could produce apparent magma residence times from ?500 ka to meaningless futuristic storage times. New ages for the southern domes are older than the reported mean Group 6 age of ~90 ka. It is probable that the anomalously young K-Ar dates reflect incomplete extraction of Ar from feldspar and other phases contained in the analyzed obsidian. Two Group 6 domes yield similar ages of 116 ±4 ka and 117 ±7 ka and the third gives an age of 148 ±6 ka. The distinct ages likely indicate that the existing rhyolite groupings oversimplify individual eruption events. The low ^{40}Ar^{\\ast} and lack of crystals in Group 5 rhyolites inhibit their accurate dating. On the basis of relative degree of erosion to Group 4 rhyolites and crude K-Ar constraints, existing studies have assigned Group 5 rhyolites a slightly younger age. If the new ~230 ka age is representative for Group 4 rhyolites in general, then Group 5 rhyolites may also be older, implying earlier more voluminous volcanism. Alternatively, Group 5 rhyolites may have erupted at some later time (e.g., ~150 ka, possibly with the older Group 6 rhyolite). Based on analyses of three Group 7 samples eruptions in this grouping also appear to have occurred in at least two events. A small dome from the north yields a 56 ±12 ka age similar to the reported ~60 ka age of Group 7 rhyolites. Coeval eruption of Sugarloaf and Cactus Peak domes, however, appears to have occurred at 86 ±2 ka: ~40 ka later and ~15 ka earlier, respectively, than their K-Ar dates would indicate. Clearly, accurate eruption ages are needed to understand Coso's volcanic and magmatic history and to test models that predict future eruptions.

Simon, J. I.; Renne, P. R.; Vazquez, J.

2006-12-01

93

Evolution of vertical permeability in Coso Geothermal Well 58A-10  

NASA Astrophysics Data System (ADS)

Static temperature (T) profiles in geothermal systems record the relative role of conductive and advective heat transport. Under near steady-state conditions these profiles can reveal the long-term average permeability (k) along the T profile to an order of magnitude by solving for the advective component. Well 58A-10 in the undisturbed margin of the Coso Geothermal Field, CA, offers the opportunity to quantify vertical variations in k that provide a critical insight into the life cycle of geothermal systems. This well has three distinct zones of T gradient: a shallow zone from 400-1100 m depth of 100 ° C/km, a near-isothermal intermediate zone from 1100-2900 m, and a basal zone >2900 m of 100 ° C/km. Simple analytical solutions for 1-D heat transport and convective instability can be fit to the observed temperature profiles in the upper two zones. From these solutions the shallow zone requires k<10-17 m2 whereas the intermediate zone requires k>10-13.5 m2, indicating a >103 k difference between these intervals despite similar host rocks and fracture populations. The difference in 1-D, vertical k between the upper two zones appears to arise from the minerals that "heal" fractures as revealed by surface mapping, cuttings and core analysis, and geophysical logs. Initial brittle fracture and frictional slip in low porosity crystalline rocks causes dilation owing to surface roughness along fracture walls, brecciation, and micro-cracking. Yet active precipitation and alteration in geothermal areas implies rapid healing that requires fracture generation or reactivation to maintain k. Fault rocks enriched in neoformed clays minimize dilation during slip and can reduce k to lower than 10-19 m2. Reduced frictional strength in clay-rich faults also promotes their reactivation over the generation of new faults. Since the stability of clays is restricted to relatively low temperature, clay-rich faults are confined to shallow depths. Thus, a fault core enriched in clays at shallow depths becomes a persistent barrier to cross-fault flow that effectively reduces vertical k. Conversely precipitation of calcite or silica dominates healing at greater depth. These minerals retain dilatant behavior during slip that regenerates k as revealed by crack-seal textures. Thus k remains high enough to support convection and isothermal T profiles.

Davatzes, N. C.; Hickman, S. H.

2007-12-01

94

Triaxial deformation of the brittle crust in transtension: Coso-China Lake region, eastern margin of the Sierra Nevada Microplate, southeastern California  

NASA Astrophysics Data System (ADS)

Transtension is oblique divergence between bounding plates or blocks, and combines a coaxial orthogonal extension with a deformation zone boundary parallel noncoaxial component to generate bulk non-plane (triaxial) constrictional strain. The instantaneous stretching direction bisects the acute angle between the direction of divergence (transport direction, TD) and the zone boundary orthogonal. The angle between the zone boundary (zb) and TD determines the dominance of the coaxial or noncoaxial component of strain. Simultaneous normal and wrench fault arrays accommodate horizontal extension, and vertical and horizontal shortening. Structures and blocks in transtension rotate both with and against vorticity, around both vertical and horizontal axes. As structures rotate to positions no longer favorable for slip, they are superimposed by new structures, resulting in apparent multi-phase deformation that is actually polyphase deformation produced by the same event. Thus given the geometry of a transtensional zone, the orientations of the instantaneous strain axes can be derived, and orientations of expected associated structures can be predicted. These theoretical results are compared to extensive field measurements, supplemented by geophysical and geodetic constraints, from a young active transtensional zone, which describe the 3D shape of the on-going deformation. The Sierra Nevada Microplate is separating from North America at a rate of ~6 mm/yr between the Argus Range and the southern Sierra Nevada Mountains. Within this zone, the Coso-China Lake region is an area of moderate geodetic strain rate (est. 10-15/s), nearly continuous seismicity, high heatflow, active bimodal volcanism, and geothermal activity. Simultaneous coaxial and noncoaxial strain components result in coaxially dominated bulk constriction, and produces a complex system of normal, strike-slip, and oblique slip faults and associated constrictional folding and crustal thinning. Using straightforward assumptions regarding the constancy of zone boundaries, transport direction, strain rate/duration, and volume, and the retro- deformation of the Sierra Nevada Microplate, the calculated strain rate over time and the overall % extension for the northern Coso region is nearly half that of the southern Coso region. Variations in the width of the transtensional zone result in increasing or decreasing strain rates, vertical shortening, and elevation, and may explain the greater elevation/topography of N. Coso vs. that of the Indian Wells Valley. Variations in the angle between TD and zb through time exert influence over the dominant style of deformation within the transtensional zone. This may partly explain the observed dominance of more coaxial deformation in N. Coso vs. more noncoaxial deformation in S. Coso. Faults in the region cut all lithologies, including Mesozoic Sierra Nevada batholithic basement, Plio- Pleistocene volcanics, and Quaternary sediments, and are seen to reactivate both preexisting Mesozoic Sierra Nevada basement joints and shear zones, and late Miocene-Pliocene faults which accommodated the uplift and exhumation of the northern Coso range and associated Coso Formation. Younger off-fault brittle fracture and joint geometries kinematically resolve transtension, and occur around both outer block regions and internally throughout fault bounded blocks. An examination of the spatial, geographic, and temporal distributions of faults and brittle features in the Coso-China Lake region demonstrates partitioning of strain and kinematic reactivation of existing structures during regional transtension.

Taylor, T. R.; Dewey, J. F.

2006-12-01

95

Solar 'hot spots' are still hot  

NASA Technical Reports Server (NTRS)

Longitude distributions of solar flares are not random but show evidence for active zones (or hot spots) where flares are concentrated. According to a previous study, two hot spots in the northern hemisphere, which rotate with a synodic period of about 26.72 days, produced the majority of major flares, during solar cycles 20 and 21. The more prominent of these two hot spots is found to be still active during the rising part of cycle 22, producing the majority of northern hemisphere major flares. The synodic rotation period of this hot spot is 26.727 + or - 0.007 days. There is also evidence for hot spots in the southern hemisphere. Two hot spots separated by 180 deg are found to rotate with a period of 29.407 days, with one of them having persisted in the same locations during cycles 19-22 and the other, during cycles 20-22.

Bai, Taeil

1990-01-01

96

Modelling Hot Air Balloons.  

ERIC Educational Resources Information Center

A macroscopic way of modeling hot air balloons using a Newtonian approach is presented. Misleading examples using a car tire and the concept of hot air rising are discussed. Pressure gradient changes in the atmosphere are used to explain how hot air balloons work. (KR)

Brimicombe, M. W.

1991-01-01

97

Transtensional Deformation of the Brittle Crust: Field Observations and Theoretical Applications in the Coso-China Lake Region, Eastern Margin of the Sierra Nevada Microplate, Southeastern California  

Microsoft Academic Search

The focus of this work is the description of non-plane strain brittle deformation through field observations and theoretical applications. The seismically and volcanically active Coso—China Lake region in the transtensional Eastern California shear zone is an exemplary location for field observation of brittle structure. The region deforms in a constrictional strain field, well-described by earthquake focal mechanisms and GPS measurements,

Tatia R. Taylor; John F. Dewey; Francis C. Monastero

2008-01-01

98

Chiral-selective CoSO4/SiO2 catalyst for (9,8) single-walled carbon nanotube growth.  

PubMed

Electronic and optical properties of single-walled carbon nanotubes (SWCNTs) correlate with their chiral structures. Many applications need chirally pure SWCNTs that current synthesis methods cannot produce. Here, we show a sulfate-promoted CoSO(4)/SiO(2) catalyst, which selectively grows large-diameter (9,8) nanotubes at 1.17 nm with 51.7% abundance among semiconducting tubes and 33.5% over all tube species. After reduction in H(2) at 540 °C, the catalyst containing 1 wt % Co has a carbon yield of 3.8 wt %, in which more than 90% is SWCNT. As compared to other Co catalysts used for SWCNT growth, the CoSO(4)/SiO(2) catalyst is unique with a narrow Co reduction window under H(2) centered at 470 °C, which can be attributed to the reduction of highly dispersed CoSO(4). X-ray absorption spectroscopy (XAS) results suggested the formation of Co particles with an average size of 1.23 nm, which matches the diameter of (9,8) tubes. Density functional theory study indicated that the diameter of structurally stable pure Co particles is scattered, matching the most abundant chiral tubes, such as (6,5) and (9,8). Moreover, the formation of such large Co particles on the CoSO(4)/SiO(2) catalyst depends on sulfur in the catalyst. XAS results showed that sulfur content in the catalyst changes after catalyst reduction at different conditions, which correlates with the change in (n,m) selectivity observed. We proposed that the potential roles of sulfur could be limiting the aggregation of Co atoms and/or forming Co-S compounds, which enables the chiral selectivity toward (9,8) tubes. This work demonstrates that catalysts promoted with sulfur compounds have potentials to be further developed for chiral-selective growth of SWCNTs. PMID:23215361

Wang, Hong; Wei, Li; Ren, Fang; Wang, Qiang; Pfefferle, Lisa D; Haller, Gary L; Chen, Yuan

2013-01-22

99

Accessory mineral U–Th–Pb ages and 40 Ar\\/ 39 Ar eruption chronology, and their bearing on rhyolitic magma evolution in the Pleistocene Coso volcanic field, California  

Microsoft Academic Search

We determined Ar\\/Ar eruption ages of eight extrusions from the Pleistocene Coso volcanic field, a long-lived series of small\\u000a volume rhyolitic domes in eastern California. Combined with ion-microprobe dating of crystal ages of zircon and allanite from\\u000a these lavas and from granophyre geothermal well cuttings, we were able to track the range of magma-production rates over the\\u000a past 650 ka at

Justin I. Simon; Jorge A. Vazquez; Paul R. Renne; Axel K. Schmitt; Charles R. Bacon; Mary R. Reid

2009-01-01

100

Radioisotopic Age Constraints on Crystallization, Crystal Inheritance, and Eruption of Coso's Pleistocene Rhyolites: Tracking the Evolution of a Silicic Magma System  

NASA Astrophysics Data System (ADS)

Radioisotopic dating at Coso provides a direct assessment of the rates at which large silicic magma reservoirs develop and whether upper crustal reservoirs remain thermally viable for protracted amounts of time. We dated a representative suite of Coso extrusions (8 units) ranging in age from ~230 ka to ~56 ka using Ar/Ar techniques, with additional analyses forthcoming. Accurate eruption ages are required to track secular geochemical and petrological changes within the magma system. We also dated zircon from a granodiorite core sample from injection well 46A-19RD and in favorable cases we were able to separate and date accessory minerals (zircon and allanite) from the crystal-poor extrusions. Application of accessory mineral dating is a robust approach for quantifying the time scales associated with physicochemical changes in magmas reservoirs. For example, the age distribution and character of zircons from Coso's ~600 ka Devils Kitchen rhyolite led Miller and Wooden (2004) to suggest that it was emplaced in the crust as a near-solidus crystal mush over an ~200 ka period prior to eruption. Our U-Th ages for zircon and allanite obtained by ion microprobe analysis, when compared to their respective ~115 ka (Dome 24) and ~85 ka (Cactus Peak and Sugarloaf Mountain) Ar/Ar ages, yield near-eruption ages and little evidence of recycled zircon (or allanite) from their older Pleistocene predecessors. Likewise zircon ages in the granodiorite exhibit evidence for a single crystallization event at ~200 ka. However, U-Pb dating of a significant subset of zircon in Coso's ~85 ka rhyolites and in the granodiorite core yield Mesozoic ages between ca. 100 and 200 Ma. The latter includes grains that previously yielded U-Th isotope ages within error of secular equilibrium. Two end-member cases may account for the bimodal distribution of zircon ages and evidence for assimilation and crustal contamination of low temperature (?800 °C) rhyolite, as well as secular changes in their trace element compositions. Post ~230 ka extrusions may have tapped a persistent and integrated magma chamber. If a single long-lived magma reservoir applies to Pleistocene Coso then trace element variations (e.g., La/Nd) track its chemical differentiation. Alternatively trace element changes may reflect separate magma generation events with distinct source components. The observed decrease in the La/Nd ratio of post ~115 ka extrusions, which is often caused by fractionation of allanite or monazite, can be used as a monitor of fractional crystallization differentiation. However this trend is also consistent with auto-assimilation of highly evolved intrusions. Increases in the La/Nd ratio in Coso's ~230 ka to ~115 ka rhyolites likely reflect an episode of magma replenishment by less evolved melt, but could be due to incorporation of allanite-rich cumulate materials. Fluctuating La/Nd ratios recorded by the succession of Coso rhyolite extrusions, therefore, either represents: (1) a single long-lived reservoir that incorporated and/ or was rejuvenated by a less evolved component starting at ~230 ka, then was contaminated by a more evolved component by ~115 ka, and finally incorporated Mesozoic crust, as indicated by the xenocryst ages showing up in the ~85 ka rhyolites, or (2) the existence of a number of distinct magma bodies that formed and evolved more or less independently.

Simon, J. I.; Vazquez, J. A.; Renne, P. R.; Reid, M. R.; Schmitt, A. K.

2007-12-01

101

Locating an active fault zone in Coso geothermal field by analyzing seismic guided waves from microearthquake data  

SciTech Connect

Active fault systems usually provide high-permeability channels for hydrothermal outflow in geothermal fields. Locating such fault systems is of a vital importance to plan geothermal production and injection drilling, since an active fault zone often acts as a fracture-extensive low-velocity wave guide to seismic waves. We have located an active fault zone in the Coso geothermal field, California, by identifying and analyzing a fault-zone trapped Rayleigh-type guided wave from microearthquake data. The wavelet transform is employed to characterize guided-wave's velocity-frequency dispersion, and numerical methods are used to simulate the guided-wave propagation. The modeling calculation suggests that the fault zone is {approx} 200m wide, and has a P wave velocity of 4.80 km/s and a S wave velocity of 3.00 km/s, which is sandwiched between two half spaces with relatively higher velocities (P wave velocity 5.60 km/s, and S wave velocity 3.20 km/s). zones having vertical or nearly vertical dipping fault planes.

SGP-TR-150-16

1995-01-26

102

Feasibility of CO?/SO? uptake enhancement of calcined limestone modified with rice husk ash during pressurized carbonation.  

PubMed

The calcination/carbonation cycle using calcium-based sorbents appears to be a viable method for carbon dioxide (CO?) capture from combustion gases. Recent attempts to improve the CO?/SO? uptake of a calcium-based sorbent modified by using rice husk ash (RHA) in the hydration process have succeeded in enhancing its effectiveness. The optimal mole ratio of RHA to calcined limestone (M(Si/Ca)) was adjusted to 0.2. The cyclic CO? capture characteristics and the SO? uptake activity of the modified sorbent were evaluated in a calcination/pressurized carbonation reactor system. Scanning electron microscope (SEM) images and X-ray diffraction (XRD) spectrum of the sorbent were also taken to supplement the study. The results showed that the carbonation conversion was greatly increased for the sorbent with M(Si/Ca) ratio of 0.2. For this sorbent formulation the optimal operating conditions were 700-750 °C and 0.5-0.7 MPa. CO? absorption was not proportional to CO? concentration in the carbonation atmosphere, but was directly related to reaction time. The CO? uptake decreased in the presence of SO?. SO? uptake increased, and the total calcium utilization was maintained over multiple cycles. Analysis has shown that the silicate component is evenly or well distributed, and this serves as a framework to prevent sintering, thus preserving the available microstructure for reaction. The sorbent also displayed high activity to SO? absorption and could be used to capture CO? and SO? simultaneously. PMID:22054590

Chen, Huichao; Zhao, Changsui; Ren, Qiangqiang

2012-01-01

103

Regional Tectonics of the Coso Geothermal Area: Three-dimensional Vp and Vp/Vs Models, Spatial-Temporal Seismicity Patterns, and Seismogenic Deformation Along the Intracontinental Plate Boundary in Central Eastern California  

NASA Astrophysics Data System (ADS)

We use regional earthquake data to synthesize the tectonics of the southern Walker Lane belt and Coso Range in central eastern California. We calculated three-dimensional models of the Vp and Vp/Vs structure of the upper and middle crust. Using these models, we also determine three-dimensional Vs and Poisson's ratio models. The changes in seismic velocities across the region are small, except for low velocities in sedimentary basins and a ~2-km positive elevation of the basement velocities (Vp > 6 km/s) beneath the southern Sierra Nevada. Localized low-Vp and low-Vs zones beneath the central Coso Range image a geothermal reservoir at 0- to 3-km depth, as well as distinct low-velocity anomalies in the depth range of ~8 to ~12 km. Because the Vp/Vs has average crustal values within this broader zone, we interpret the anomaly to indicate a zone of few percent geothermal brines extending from 8 to 12 km depth. In addition, an embedded highly localized poorly resolved zone (possibly as small as 1 km3) of slightly above average Vp/Vs and higher Poisson's ratio is a tentative suggestion of a small volume percent of magma present at depth of ~10 km. We also relocated the seismicity in the Coso region using absolute traveltimes and differential traveltimes determined from waveform cross correlation. The relocated seismicity forms several spatially clustered lineaments along the southeast side of the Sierra Nevada and in the Indian Wells Valley and vicinity of the Coso geothermal field, which coincide with mapped late Quaternary faults in the region. The base of seismicity shallows from a regional depth of about ~11 to ~5 km beneath the central Coso Range, which we interpret as evidence for shallowing of the brittle-ductile transition zone beneath the geothermal field. In addition to abundant background seismicity, two large earthquake swarms, located 5 to 8 km to the west of Coso, occurred in April to May 1992 and May to June 2001. Two dual main shock-aftershock sequences also occurred as follows: the 1994 sequence near Ridgecrest and the later Coso earthquake sequence from late 1996 to early 1998, with the pairs of main shocks spaced 47 days and 16 months apart, respectively. Kinematic analysis of the focal mechanisms indicates that the crustal stress loading process varies across the region. The low-Vp anomaly, abundant seismicity, and crustal thinning provide quantitative evidence for the Coso region being an extensional releasing step over between two northwest-striking dextral faults: The Airport Lake fault zone to the south, and the Owens Valley fault to the north.

Hauksson, E.; Unruh, J.

2007-12-01

104

Solar Hot Box  

NSDL National Science Digital Library

In this lesson, students explore different aspects of solar energy by building a solar hot box and testing various colors and materials to find the maximum temperature that can be reached. They will review the basic needs for alternative energy sources, identify three materials and colors that will produce maximum heat, and solve a design problem for the hot box.

105

Hot ice computer  

Microsoft Academic Search

We experimentally demonstrate that supersaturated solution of sodium acetate, commonly called ‘hot ice’, is a massively-parallel unconventional computer. In the hot ice computer data are represented by a spatial configuration of crystallization induction sites and physical obstacles immersed in the experimental container. Computation is implemented by propagation and interaction of growing crystals initiated at the data-sites. We discuss experimental prototypes

Andrew Adamatzky

2009-01-01

106

The Earth's Hot Spots.  

ERIC Educational Resources Information Center

Hot spots are isolated areas of geologic activity where volcanic eruptions, earthquakes, and upwelling currents occur far from plate boundaries. These mantle plumes are relatively stable and crustal plates drift over them. The nature and location of hot spots (with particular attention to the Hawaiian Islands and Iceland) are discussed. (DH)

Vink, Gregory E.; And Others

1985-01-01

107

Hot air balloon engine  

Microsoft Academic Search

This paper describes a solar powered reciprocating engine based on the use of a tethered hot air balloon fuelled by hot air from a glazed collector. The basic theory of the balloon engine is derived and used to predict the performance of engines in the 10kW to 1MW range. The engine can operate over several thousand metres altitude with thermal

Ian Edmonds

2009-01-01

108

Hot Air Balloon  

NSDL National Science Digital Library

In this activity, learners build a hot air balloon using just a few sheets of tissue paper and a hair dryer. Use this activity to demonstrate how hot air rises due to density and how the volume of gas increases with temperature (Charles's Law).

Centers, Oakland D.

2012-01-01

109

Hot yoga and pregnancy  

PubMed Central

Abstract Question One of my pregnant patients wishes to continue her hot yoga exercises during pregnancy. Is this practice safe? Answer With the increased risk of neural tube defects and possibly of other malformations among fetuses exposed to excessive heat, pregnant women should avoid practising hot yoga during pregnancy. PMID:24452558

Chan, Justin; Natekar, Aniket; Koren, Gideon

2014-01-01

110

6. HOT AIR PORTION OF DAMPERS. Hot Springs National ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. HOT AIR PORTION OF DAMPERS. - Hot Springs National Park, Bathhouse Row, Lamar Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

111

Three-dimensional Vp and Vp/Vs models in the Coso geothermal area, California: Seismic characterization of the magmatic system  

NASA Astrophysics Data System (ADS)

We combine classic and state-of-the-art techniques to characterize the seismic and volcanic features in the Coso area in southern California. Seismic tomography inversions are carried out to map the variations of Vp, Vs, and Vp/Vs beneath Coso. The velocities in the top layers of our model are correlated with the surface geological features. The Indian Wells Valley, with high silica content sediment strata, shows low-velocity anomalies up to 3 km depth, whereas the major mountain ranges, such as the south Sierra Nevada and the Argus Range, show higher velocities. The resulting three-dimensional velocity model is used to improve absolute locations for all local events between January 1981 and August 2011 in our study area. We then apply similar-event cluster analysis, waveform cross correlation, and differential time relocation methods to improve relative event location accuracy. A dramatic sharpening of seismicity patterns is obtained after using these methods. We also estimate high-resolution near-source Vp/Vs ratio within each event cluster using the differential times from waveform cross correlation. The in situ Vp/Vs method confirms the trend of the velocity variations from the tomographic results. An anomalous low-velocity body with low Vp, Vs, and Vp/Vs ratios, corresponding to the ductile behavior underlying the Coso geothermal field from 6 to 12 km depth, can be explained by the existence of frozen felsic magmatic materials with the inclusion of water. The material is not likely to include pervasive partial melt due to a lack of high Vp/Vs ratios.

Zhang, Qiong; Lin, Guoqing

2014-06-01

112

Automatic hot water recovery system  

SciTech Connect

Heat in the hot water lines of a water system is automatically recovered by providing a bridge conduit between the cold water lines and the hot water lines and by depressurizing the hot water lines relative to the cold water lines thereby to automatically direct higher pressure cold water into the hot water lines through the interconnection, which preferably is located near the hot water outlet. The higher pressure cold water forces the hot water back into the storage tank and out of the hot water lines until pressure is equalized. Loss of unused heat trapped in the hot water lines is minimized thereby saving energy.

Haws, S.K.

1982-03-30

113

CSA Hot Topics Series  

NSDL National Science Digital Library

The Hot Topics series provides a free sampling of the resources in Cambridge Scientific Abstracts (CSA) and the Internet Database Service (IDS). The 30 topics span subjects in the humanities, engineering, environmental policy, and medicine. Each Hot Topic gives an overview of the subject, key citations with abstracts, a list of Websites, a glossary, a comment form so that users can correspond with the editors, and a "source" section, which explains from which of CSA's paid services the resources were culled. The latest hot topic is MicroElectroMechanical systems (MEMS), "small integrated devices or systems that combine electrical and mechanical components."

114

Hot Binaries: Observational Results.  

National Technical Information Service (NTIS)

Interferometric work on hot binary and multiple stars is summarized, from the earliest eyepiece interferometry to recent speckle and AO duplicity surveys. Multiplicity fractions for cluster, field, and runaway O stars are discussed.

W. I. Hartkopf

2010-01-01

115

Hot and dark matter  

E-print Network

In this thesis, we build new Effective Field Theory tools to describe the propagation of energetic partons in hot and dense media, and we propose two new reactions for dark matter in the early universe. In the first part, ...

D'Eramo, Francesco

2012-01-01

116

Saturn's Hot Plasma Explosions  

NASA Video Gallery

This animation based on data obtained by NASA's Cassini Spacecraft shows how the "explosions" of hot plasma on the night side (orange and white) periodically inflate Saturn's magnetic field (white ...

117

Hot dry rock update  

SciTech Connect

Hot-dry-rock experiments at Los Alamos, NM since 1970 are reviewed briefly, with emphasis on activities since 1977. These include hydraulic fracturing, seismic mapping, fracture mapping, and development of downhole instrumentation. (MHR)

Whetten, J.; Brown, D.; Potter, R.

1983-12-01

118

Micro-seismicity, fault structure, and hydrologic compartmentalization within the Coso Geothermal Field, California, from 1996 until present  

NASA Astrophysics Data System (ADS)

Geothermal reservoirs derive their capacity for fluid and heat transport in large part from faults and fractures. In conventional reservoirs, preexisting faults and fractures are the main conduits for fluid flow, while in enhanced geothermal systems (EGS), fractures and faults that are generated or enlarged (i.e., through increases in surface area and aperture) by hydraulic stimulation provide the main pathways for fluids and heat. In both types of geothermal systems, seismicity can be used to locate active faults, which can act either as conduits for along-fault fluid flow and/or barriers to cross-fault flow. We relocate 14 years of seismicity in the Coso Geothermal Field (CGF) using differential travel time relocations to improve our knowledge of the subsurface geologic and hydrologic structure. The seismicity at Coso has been recorded on a local network operated by the Navy Geothermal Program, which provides exceptional coverage and quality of data. Using the relocated catalog, we employ a newly developed algorithm for fault identification using the spatial seismicity distribution and a priori constraints on fault zone width derived from local geologic mapping. We avoid having to assume a particular fault-normal seismicity distribution by finding regions of maximum spatial seismicity density. Assuming a maximum spatial density is physically plausible since faults, or more accurately fault zones, generate most of the associated seismicity within a central fault core or damage zone. These techniques are developed for naturally occurring, active faults within the CGF on which seismicity is induced, in part, by changes in production and injection. They can also be applied to EGS if seismicity is induced within newly created fracture systems of comparable width or if this seismicity is generated by stimulating pre-existing, partially sealed faults. The results of the relocations reveal that clouds of seismicity shrink into distinct oblate volumes of seismicity in which we interpret the faults to be located. The faults that are identified reveal a complicated image of the subsurface structure of the CGF and tend to fall within and between hydrologic compartments known to exist within the reservoir. This suggests that some of the faults in the CGF serve as conduits for fluids and heat, while others seal portions of the reservoir and function as hydrologic domain boundaries. We anticipate that our method can be applied in many conventional geothermal systems, either before plant design to guide well placement (if natural seismicity is present and recorded well) or as part of evaluating the hydraulic network stimulated by EGS. This type of information will also be useful in locating and designing EGS, either in seismically active areas lacking prior geothermal development or on the margins of existing geothermal fields. The improved knowledge of subsurface structure provided by this type of modeling can also aid in assessing seismic hazards associated with EGS stimulations or ongoing injection and production when used in concert with fault-stress transfer models.

Kaven, J. O.; Hickman, S.; Davatzes, N. C.

2010-12-01

119

The Hot Tub Mystery  

NSDL National Science Digital Library

This case study sets up a mystery and asks students to solve it using science: why was the couple found dead in their hot tub? The material asks students to connect seemingly unrelated factors, such as blood pressure, hot water and alcohol. The material would be most appropriate for lower level undergraduate students. The case study and teaching notes may be downloaded in PDF format. The site also includes a section for instructor feedback where general comments may be read and contributed.

House, Herbert

2011-01-06

120

Seismic monitoring of EGS tests at the Coso Geothermal area, California, using accurate MEQ locations and full moment tensors  

SciTech Connect

We studied high-resolution relative locations and full moment tensors of microearthquakes (MEQs) occurring before, during and following Enhanced Geothermal Systems (EGS) experiments in two wells at the Coso geothermal area, California. The objective was to map new fractures, determine the mode and sense of failure, and characterize the stress cycle associated with injection. New software developed for this work combines waveform crosscorrelation measurement of arrival times with relative relocation methods, and assesses confidence regions for moment tensors derived using linearprogramming methods. For moment tensor determination we also developed a convenient Graphical User Interface (GUI), to streamline the work. We used data from the U.S. Navy’s permanent network of three-component digital borehole seismometers and from 14 portable three-component digital instruments. The latter supplemented the permanent network during injection experiments in well 34A-9 in 2004 and well 34-9RD2 in 2005. In the experiment in well 34A-9, the co-injection earthquakes were more numerous, smaller, more explosive and had more horizontal motion, compared with the pre-injection earthquakes. In the experiment in well 34-9RD2 the relocated hypocenters reveal a well-defined planar structure, 700 m long and 600 m high in the depth range 0.8 to 1.4 km below sea level, striking N 20° E and dipping at 75° to the WNW. The moment tensors show that it corresponds to a mode I (opening) crack. For both wells, the perturbed stress state near the bottom of the well persisted for at least two months following the injection.

Foulger, G.R.; B.R. Julian, B.R.; F. Monastero

2008-04-01

121

Use of U and Th Decay-Series Disequilibrium to Characterize Geothermal Systems: An Example from the Coso Geothermal System  

NASA Astrophysics Data System (ADS)

Uranium and thorium decay series isotopes were measured in fluids and solids in the Coso geothermal system to assess the utility and constrain the limitations of the radioisotopic approach to the investigation of rock-water interaction. Fluid radioisotope measurements indicate substantial kilometer-scale variability in chemistry. Between 1988 and 1990, radium isotope activity ratios indicate temporal variability, which is exhibited by apparent mixing relationships observed as a function of time for single wells. Activity ratios of Ra-224/Ra-226 and Ra- 228/Ra-226, and the processes that contribute and remove these radionuclide to and from the fluids, constrain residence times of fluids and may help constrain fluid velocities in the geothermal system. Activity ratios of Ra- 224/Ra-226 > ten were measured. In groundwater and geothermal systems ratios of Ra-224/Ra-226 > ten are limited to zones of thermal upwelling or very young (days to weeks) waters in mountainous areas. Rn-222 results indicate that radon is also an effective tracer for steam velocities within the geothermal system. Analysis of carbon dioxide and Rn-222 data indicates that the residence time of steam (time since separation from the liquid) is short (probably less than four days). Estimates of fluid velocities derived from Rn-222 and radium isotopic measurements are within an order of magnitude of velocities derived from a fluorescein tracer test. Both Rn-222 and Ra-224 activities are higher in single-phase fluids in the northwest as compared to the southeast, indicating a higher rock-surface-area/water-volume ratio in the northwest. Thus, measurements of short-lived radioisotopes and gaseous phase constituents can constrain processes and characteristics of geothermal systems that are usually difficult to constrain (e.g., surface area/volume, residence times). The NRC staff views expressed herein are preliminary and do not constitute a final judgment or determination of the matters addressed or of the acceptability of a license application for a geologic repository at Yucca Mountain.

Leslie, B. W.; Hammond, D.

2007-12-01

122

Cosmogenic 3He and 21Ne production rates calibrated against 10Be in minerals from the Coso volcanic field  

NASA Astrophysics Data System (ADS)

This study calibrates the production rate of cosmogenic 3He in pyroxene, olivine, garnet, zircon and apatite as well as 21Ne in quartz and pyroxene against the known production rate of 10Be in quartz. The Devil's Kitchen rhyolite from the Coso volcanic field in southeastern California (elev. ~ 1300 m) was chosen for this study due to its young age (~ 610 ka) and diverse mineral assemblage. Based on 10Be, our two rhyolite samples have apparent exposure ages of ~ 49 and 93 ka, indicating substantial erosion after eruption. Combining data from the two samples, we estimate sea level high latitude 3He spallation production rates of 145 ± 11, 141 ± 16, and 144 ± 30 at g - 1 a - 1 (2 ?) for pyroxene, olivine and spessartine garnet respectively. For zircon and apatite, we estimate apparent 3He spallation production rates of 114 ± 8 and 149 ± 28 at g - 1 a - 1 (2 ?) respectively. The rates for zircon and apatite are reported as apparent production rates because we do not explicitly address the redistribution of spallation produced 3He from adjacent minerals. These estimates quantitatively account for production of 3He from both cosmogenic and radiogenic neutron reactions on 6Li within the analyzed phases and also implanted from nuclear reactions in neighboring minerals; the high U, Th and Li content of this rhyolite provides a particularly rigorous test of this correction. We estimate 21Ne production rates of 17.7 ± 1.6 and 34.1 ± 3.2 at g - 1 a - 1 (2 ?) in quartz and pyroxene (Fe/Mg = 0.7 by mass) respectively. Although high U and Th contents create the potential for significant production of nucleogenic 21Ne, this component is small due to the young eruption age of the rhyolite.

Amidon, William H.; Rood, Dylan H.; Farley, Kenneth A.

2009-04-01

123

Regional tectonics of the Coso geothermal area along the intracontinental plate boundary in central eastern California: Three-dimensional Vp and Vp/Vs models, spatial-temporal seismicity patterns, and seismogenic deformation  

NASA Astrophysics Data System (ADS)

We synthesize the tectonics of the southern Walker Lane belt and Coso Range in central eastern California using regional earthquake data. First, we invert for three-dimensional models of the Vp and Vp/Vs structure of the upper and middle crust. Using these models, we also determine three-dimensional Vs and Poisson's ratio models. The changes in seismic velocities across the region are small, except for low velocities in sedimentary basins and a ˜2-km positive elevation of the basement velocities (Vp > 6 km/s) beneath the southern Sierra Nevada. Localized low-Vp and low-Vs zones beneath the central Coso Range image a geothermal reservoir at 0- to 3-km depth, as well as distinct low-velocity anomalies in the depth range of ˜8 to ˜12 km. Because the Vp/Vs has average crustal values within this broader zone, we interpret the anomaly to indicate a zone of few percent geothermal brines extending from 8- to 12-km depth. In addition, an embedded highly localized poorly resolved zone (possibly as small as 1 km3) of slightly above average Vp/Vs and higher Poisson's ratio is a tentative suggestion of a small volume percent of magma present at depth of ˜10 km. Second, we relocated the seismicity in the region using absolute traveltimes and differential traveltimes determined from waveform cross correlation. The relocated seismicity forms several spatially clustered lineaments along the southeast side of the Sierra Nevada and in the Indian Wells Valley and vicinity of the Coso geothermal field, which coincide with mapped late Quaternary faults in the region. The base of seismicity shallows from a regional depth of about ˜11 to ˜5 km beneath the central Coso Range, which we interpret as evidence for shallowing of the brittle-ductile transition zone beneath the geothermal field. In addition to abundant background seismicity, two large earthquake swarms, located 5 to 8 km to the west of Coso, occurred in April to May 1992 and May to June 2001. Two dual main shock-aftershock sequences also occurred as follows: the 1994 sequence near Ridgecrest and the later Coso earthquake sequence from late 1996 to early 1998, with the pairs of main shocks spaced 47 days and 16 months apart, respectively. Kinematic analysis of the focal mechanisms indicates that the crustal stress loading process varies across the region. The low-Vp anomaly, abundant seismicity, and crustal thinning provide quantitative evidence for the Coso region being an extensional releasing step over between two northwest-striking dextral faults: The Little Lake and Airport Lake fault zones to the south, and the Owens Valley fault to the north.

Hauksson, Egill; Unruh, Jeffrey

2007-06-01

124

Fault block kinematics at a releasing stepover of the Eastern California shear zone: Partitioning of rotation style in and around the Coso geothermal area and nascent metamorphic core complex  

NASA Astrophysics Data System (ADS)

Pliocene lavas and sediments of Wild Horse Mesa in the Coso Range, CA exhibit clockwise vertical-axis rotation of fault-bounded blocks. This indicates localization of one strand of the Eastern California shear zone/Walker Lane Belt within a large-scale, transtensional, dextral, releasing stepover. We measured rotations paleomagnetically relative to two different reference frames. At two localities we averaged secular variation through sedimentary sections to reveal rotation or its absence relative to paleogeographic north. Where sediments are lacking we used areally-extensive lava flows from individual cooling units or short eruptive episodes to measure the relative rotation of localities by comparing their paleomagnetic remanence directions to one another. At the western edge of Wild Horse Mesa the fanglomerate member of the Coso Formation (c.a. 3 Ma) exhibits between 8.4° ± 7.8° and 26.2° ± 9.0° (two endmember models of a continuum) absolute clockwise rotation. Within Wild Horse Mesa, 3-3.5 Ma lavas at 5 different localities exhibit about 12.0° ± 4.6° (weighted mean) clockwise rotation relative to the margins of the area, a result statistically indistinguishable from the absolute rotation. Hence the segment of the Eastern California shear zone passing through Wild Horse Mesa has caused vertical axis rotation of fault-bounded blocks as part of the overall dextral shear strain. The magnitude of block rotation at Wild Horse Mesa suggests that rotation has accommodated: 1) 1.5 km of dextral shear along an azimuth of about north 30° west since ca. 3 Ma between the area's bounding faults and 2) 2 km of extension perpendicular to the Coso Wash normal fault during this same period. This corresponds to 13-25% extension across the mesa. In contrast to Wild Horse Mesa, the opposite (western) side of the trace of the Coso Wash normal fault hosts the Coso geothermal area and what Monastero et al. [F.C. Monastero, A.M. Katzenstein, J.S. Miller, J.R. Unruh, M.C. Adams, K. Richards-Dinger, The Coso geothermal field: a nascent metamorphic core complex, Geol. Soc. Amer. Bull. 117 (2005) 1534-1553.] characterize as a nascent metamorphic core complex. Consistent with upper plate disruption above a detachment, surface rocks (i.e. the upper plate of the detachment system) at the Coso geothermal area are tilted westward. However they appear to exhibit no detectable rotation. Thus, the style of block rotation may be partitioned: with clockwise vertical-axis rotation dominating in the Wild Horse Mesa and horizontal axis rotation (tilting) in the geothermal area.

Pluhar, Christopher J.; Coe, Robert S.; Lewis, Jonathan C.; Monastero, Francis C.; Glen, Jonathan M. G.

2006-10-01

125

Hot corrosion of Co-Cr, Co-Cr-Al, and Ni-Cr alloys in the temperature range of 700-750 deg C  

NASA Technical Reports Server (NTRS)

The effect of SO3 pressure in the gas phase on the Na2SO4 induced hot corrosion of Co-Cr, Ni-Cr, and Co-Cr-Al alloys was studied in the temperature range 700 to 750 C. The degradation of the Co-Cr and Ni-Cr alloys was found to be associated with the formation of liquid mixed sulfates (CoSO4-Na2SO4 or NiSO4-Na2SO4) which provided a selective dissolution of the Co or Ni and a subsequent sulfidation oxidation mode of attack which prevented the maintenance of a protective Cr2O3 film. A clear mechanism was not developed for the degradation of Co-Cr-Al alloys. A pitting corrosion morphology was induced by a number of different mechanisms.

Chiang, K. T.; Meier, G. H.

1980-01-01

126

Lead and strontium isotopic evidence for crustal interaction and compositional zonation in the source regions of Pleistocene basaltic and rhyolitic magmas of the Coso volcanic field, California  

USGS Publications Warehouse

The isotopic compositions of Pb and Sr in Pleistocene basalt, high-silica rhyolite, and andesitic inclusions in rhyolite of the Coso volcanic field indicate that these rocks were derived from different levels of compositionally zoned magmatic systems. The 2 earliest rhyolites probably were tapped from short-lived silicic reservoirs, in contrast to the other 36 rhyolite domes and lava flows which the isotopic data suggest may have been leaked from the top of a single, long-lived magmatic system. Most Coso basalts show isotopic, geochemical, and mineralogic evidence of interaction with crustal rocks, but one analyzed flow has isotopic ratios that may represent mantle values (87Sr/86Sr=0.7036,206Pb/204Pb=19.05,207Pb/204Pb=15.62,208Pb/204Pb= 38.63). The (initial) isotopic composition of typical rhyolite (87Sr/86Sr=0.7053,206Pb/204Pb=19.29,207Pb/204Pb= 15.68,208Pb/204Pb=39.00) is representative of the middle or upper crust. Andesitic inclusions in the rhyolites are evidently samples of hybrid magmas from the silicic/mafic interface in vertically zoned magma reservoirs. Silicic end-member compositions inferred for these mixed magmas, however, are not those of erupted rhyolite but reflect the zonation within the silicic part of the magma reservoir. The compositional contrast at the interface between mafic and silicic parts of these systems apparently was greater for the earlier, smaller reservoirs. ?? 1984 Springer-Verlag.

Bacon, C.R.; Kurasawa, H.; Delevaux, M.H.; Kistler, R.W.; Doe, B.R.

1984-01-01

127

Automatic hot water recovery system  

Microsoft Academic Search

Heat in the hot water lines of a water system is automatically recovered by providing a bridge conduit between the cold water lines and the hot water lines and by depressurizing the hot water lines relative to the cold water lines thereby to automatically direct higher pressure cold water into the hot water lines through the interconnection, which preferably is

Haws

1982-01-01

128

Automatic hot water recovery system  

Microsoft Academic Search

A heat recovery system recovers hot water to an insulated tank through reciprocally variable volume chambers which are biased to draw water from hot water lines when the pressure throughout the system is equalized. One-way valving means permits continuous water flow when desired through the hot water tank to the hot water outlet. In a specific embodiment, bias is effected

Haws

1985-01-01

129

Hot Oil Removes Wax  

NASA Technical Reports Server (NTRS)

Mineral oil heated to temperature of 250 degrees F (121 degrees C) found effective in removing wax from workpieces after fabrication. Depending upon size and shape of part to be cleaned of wax, part immersed in tank of hot oil, and/or interior of part flushed with hot oil. Pump, fittings, and ancillary tooling built easily for this purpose. After cleaning, innocuous oil residue washed off part by alkaline aqueous degreasing process. Serves as relatively safe alternative to carcinogenic and environmentally hazardous solvent perchloroethylene.

Herzstock, James J.

1991-01-01

130

Rotational hot Brownian motion  

E-print Network

We establish an effective Markov theory for the rotational Brownian motion of hot nanobeads and nanorods. Compact analytical expressions for the effective temperature and friction are derived from the fluctuating hydrodynamic equations of motion. They are verified by comparison with recent measurements and with GPU powered parallel molecular dynamics simulations over a wide temperature range. This provides unique insights into the physics of hot Brownian motion and an excellent starting point for further experimental tests and applications involving laser-heated nanobeads, nanorods and Janus particles.

Daniel Rings; Dipanjan Chakraborty; Klaus Kroy

2012-03-14

131

The distribution of hot spots  

NASA Technical Reports Server (NTRS)

Statistical analyses are compared for two published hot spot data sets, one minimal set of 42 and another larger set of 117, using three different approaches. First, the earths surface is divided into 16 equal-area fractions and the observed distribution of hot spots among them is analyzed using chi-square tests. Second, cumulative distributions about the principal axes of the hot spot inertia tensor are used to describe hot spot distribution. Finally, a hot spot density function is constructed for each of the two hot spot data sets. The methods all indicate that hot spots have a nonuniform distribution, even when statistical fluctuations are considered. To the first order, hot spots are concentrated on one half of of the earth's surface area; within that portion, the distribution is consistent with a uniform distribution. The observed hot spot densities for neither data set are explained solely by plate speed.

Stefanick, M.; Jurdy, D. M.

1984-01-01

132

Hot off the Press  

ERIC Educational Resources Information Center

In the past, the newspaper was one of the world's most used sources of information. Recently, however, its use has declined due to the popularity of cable television and the Internet. Yet the idea of reading the morning paper with a hot cup of coffee holds many warm memories for children who watched their parents in this daily ritual. In this…

Brisco, Nicole D.

2007-01-01

133

Dr. Carnelley's Hot Ice  

Microsoft Academic Search

THE remarkable observation made by Dr. Carnelley that ice in a vacuum is very permanent, even though surrounded by and apparently in contact with very hot bodies, has caused him to suppose and maintain that the ice itself is at a high temperature; a supposition which has been apparently confirmed by preliminary calorimetric determinations. This proposition has naturally met with

Oliver J. Lodge

1881-01-01

134

Hot Dog Champ Defeated  

E-print Network

Broadcast Transcript: Arthritic jaw? Recent wisdom tooth extraction? The universe saying "It is time"? Whatever. All we know is that Japan's six year domination of Nathan's Famous July 4th Hot Dog Eating contest at Coney Island came to an end...

Hacker, Randi; Tsutsui, William; Bleier, R.H.

2007-07-25

135

Hot piston ring tests  

NASA Astrophysics Data System (ADS)

As part of the DOE/NASA Automotive Stirling Engine Project, tests were made at NASA Lewis Research Center to determine whether appendix gap losses could be reduced and Stirling engine performance increased by installing an additional piston ring near the top of each piston dome. An MTI-designed upgraded Mod I Automotive Stirling Engine was used. Unlike the conventional rings at the bottom of the piston, these hot rings operated in a high temperature environment (700 C). They were made of a high temperature alloy (Stellite 6B) and a high temperature solid lubricant coating (NASA Lewis-developed PS-200) was applied to the cylinder walls. Engine tests were run at 5, 10, and 15 MPa operating pressure over a range of operating speeds. Tests were run both with hot rings and without to provide a baseline for comparison. Minimum data to assess the potential of both the hot rings and high temperature low friction coating was obtained. Results indicated a slight increase in power and efficiency, an increase over and above the friction loss introduced by the hot rings. Seal leakage measurements showed a significant reduction. Wear on both rings and coating was low.

Allen, David J.; Tomazic, William A.

1987-12-01

136

Zen Hot Dog Molecules  

ERIC Educational Resources Information Center

Substituted cycloalkanes with one branch illustrating each topic in an instructional unit can serve as summaries or reviews in courses of organic chemistry. The hungry Zen master told the hot dog vendor to make him one with everything. You can do the same for your students.

Ryan, Dennis

2009-01-01

137

Some Like it Hot  

NSDL National Science Digital Library

NASA Astrobiologist Jack Farmer is featured in this web article that focuses on microrganisms found in Yellowstone hot springs and ocean floor hydrothermal vents. Included within the article are numerous links to concepts, resources, and further readings involving exobiology. and microbiology. Downloadable Quick time videos of a discussion with Farmer and hydrothermal vent activity at the ocean floor are also available.

Bortman, Henry; Magazine, Astrobiology

138

Kamchatka's thermal hot springs  

NSDL National Science Digital Library

The Kamchatka Peninsula is featured in this website including information on geography, climate, fauna, flora, volcanoes, thermal springs, Valley of Geysers, native people, and options for travel in Kamchatka. This specific page highlights a selection of Kamchatka's hot springs, presenting basic information on temperature ranges, chemical and physical characteristics, surrounding vegetation, and general location.

Kamchatka, Vision O.

139

OECD Focus Hot File  

NSDL National Science Digital Library

In each issue of the Organization for Economic Co-operation and Development (OECD)'s Focus Hot File, recent books and government reports of interest are listed with summaries and contact information. Past listings may be browsed by country in the Focus Compendium, and related publications are hyperlinked throughout.

140

What's Hot? What's Not?  

ERIC Educational Resources Information Center

When Goldilocks finds three bowls of porridge at different temperatures in the three bears' house, she accurately assesses the situation and comes up with one of the most recognizable lines in children's literature," This porridge is too hot; this porridge is too cold; aahh, this porridge is just right!" Goldilocks' famous line is a perfect…

Buczynski, Sandy

2006-01-01

141

Hot piston ring tests  

NASA Technical Reports Server (NTRS)

As part of the DOE/NASA Automotive Stirling Engine Project, tests were made at NASA Lewis Research Center to determine whether appendix gap losses could be reduced and Stirling engine performance increased by installing an additional piston ring near the top of each piston dome. An MTI-designed upgraded Mod I Automotive Stirling Engine was used. Unlike the conventional rings at the bottom of the piston, these hot rings operated in a high temperature environment (700 C). They were made of a high temperature alloy (Stellite 6B) and a high temperature solid lubricant coating (NASA Lewis-developed PS-200) was applied to the cylinder walls. Engine tests were run at 5, 10, and 15 MPa operating pressure over a range of operating speeds. Tests were run both with hot rings and without to provide a baseline for comparison. Minimum data to assess the potential of both the hot rings and high temperature low friction coating was obtained. Results indicated a slight increase in power and efficiency, an increase over and above the friction loss introduced by the hot rings. Seal leakage measurements showed a significant reduction. Wear on both rings and coating was low.

Allen, David J.; Tomazic, William A.

1987-01-01

142

Hot corrosion of materials  

Microsoft Academic Search

Alloys and ceramics may experience accelerated corrosion at high temperatures when their surfaces are coated by a thin film of fused salt in an oxidizing environment. Because of their high thermodynamic stabilities, fused alkali sulfates are frequently deposited or condensed onto hot substrates from the combustion product gases or else by the oxidation of heavy metal contaminants in the fuel,

Robert A. Rapp

1990-01-01

143

Exercising Safely in Hot Weather  

MedlinePLUS

... older adults and people with health problems. Being hot for too long can cause hyperthermia—a heat- ... those who want to be active when it’s hot outside: l Check the weather forecast. If it’s ...

144

Hot Tub Rash (Pseudomonas Folliculitis)  

MedlinePLUS

newsletter | contact Share | Hot Tub Rash ( Pseudomonas Folliculitis) Information for adults A A A This image displays follicular elevations of the skin and small pus-filled lesions. Overview Hot tub rash ( Pseudomonas folliculitis) is an infection of ...

145

Automatic hot water recovery system  

SciTech Connect

A heat recovery system recovers hot water to an insulated tank through reciprocally variable volume chambers which are biased to draw water from hot water lines when the pressure throughout the system is equalized. One-way valving means permits continuous water flow when desired through the hot water tank to the hot water outlet. In a specific embodiment, bias is effected by a piston having opposing faces of unequal area forming reciprocally moving walls of the chambers.

Haws, S. K.

1985-05-21

146

The “Hot Particles” Data Base  

Microsoft Academic Search

During 1987–1996, more than 1,800 Chernobyl hot particles were selected by scanning thin soil layers with a dosimeter. Size\\u000a and radionuclides activity in hot particles were measurement. The “Hot particles” database (in Microsoft Access) was created\\u000a by integrating this information and complemented with data on hot particles sampled in 1986 in Poland and inside of the “Shelter”.\\u000a This database is

Marina Zhurba; Valery Kashparov; Noureddine Ahamdach; Brit Salbu; Vasyl Yoschenko; Svyatolslav Levchuk

147

Oil recovery by hot waterflooding  

Microsoft Academic Search

Injection of hot water into an oil-bearing formation to increase oil recovery has been known almost as long as conventional waterflooding. In many instances, hot water has been injected in order to increase the injectivity of wells by controlling the deposition of waxes. With the growing interest in steam-flooding during recent years, hot waterflooding has also been gaining prominence. This

Farouq Ali

1968-01-01

148

Hot Spring Metagenomics  

PubMed Central

Hot springs have been investigated since the XIX century, but isolation and examination of their thermophilic microbial inhabitants did not start until the 1950s. Many thermophilic microorganisms and their viruses have since been discovered, although the real complexity of thermal communities was envisaged when research based on PCR amplification of the 16S rRNA genes arose. Thereafter, the possibility of cloning and sequencing the total environmental DNA, defined as metagenome, and the study of the genes rescued in the metagenomic libraries and assemblies made it possible to gain a more comprehensive understanding of microbial communities—their diversity, structure, the interactions existing between their components, and the factors shaping the nature of these communities. In the last decade, hot springs have been a source of thermophilic enzymes of industrial interest, encouraging further study of the poorly understood diversity of microbial life in these habitats.

Lopez-Lopez, Olalla; Cerdan, Maria Esperanza; Gonzalez-Siso, Maria Isabel

2013-01-01

149

Hot Billet Surface Qualifier  

SciTech Connect

OG Technologies, Inc. (OGT), developed a prototype of a Hot Billet Surface Qualifier (“Qualifier”) based on OGT’s patented HotEye™ technology and other proprietary imaging and computing technologies. The Qualifier demonstrated its ability of imaging the cast billets in line with high definition pictures, pictures capable of supporting the detection of surface anomalies on the billets. The detection will add the ability to simplify the subsequent process and to correct the surface quality issues in a much more timely and efficient manner. This is challenging due to the continuous casting environment, in which corrosive water, temperature, vibration, humidity, EMI and other unbearable factors exist. Each installation has the potential of 249,000 MMBTU in energy savings per year. This represents a cost reduction, reduced emissions, reduced water usage and reduced mill scale.

Tzyy-Shuh Chang

2007-04-30

150

The hot chocolate effect  

NASA Astrophysics Data System (ADS)

The ''hot chocolate effect'' was investigated quantitatively, using water. If a tall glass cylinder is filled nearly completely with water and tapped on the bottom with a softened mallet one can detect the lowest longitudinal mode of the water column, for which the height of the water column is one-quarter wavelength. If the cylinder is rapidly filled with hot tap water containing dissolved air the pitch of that mode may descend by nearly three octaves during the first few seconds as the air comes out of solution and forms bubbles. Then the pitch gradually rises as the bubbles float to the top. A simple theoretical expression for the pitch ratio is derived and compared with experiment. The agreement is good to within the 10% accuracy of the experiments.

Crawford, Frank S.

1982-05-01

151

Hot-Wheeler-Coaster  

NSDL National Science Digital Library

Students will be put into groups of 3-4 and supplied with the necessary materials to build a hot wheels track that has at least two hills. The challenge will be to design an experiment to test whether the car will coast over a second hill that is at least as high as the first one. Be sure to allow the students the freedom to choose which hill's height to vary, as either will work to demonstrate the lesson concept.

Shaw, Steven

2011-10-13

152

Working in Hot Weather or Hot Workplace Environments Subject: Procedures and Guidelines for Working in Hot Environments  

E-print Network

Working in Hot Weather or Hot Workplace Environments Subject: Procedures and Guidelines for Working is intended to prevent potential heat induced illness as a result of hot weather or hot workplace environments in hot weather or hot workplace environments. The following parameters will serve as triggers

Lennard, William N.

153

Hot oiling spreadsheet  

SciTech Connect

One of the most common oil-field treatments is hot oiling to remove paraffin from wells. Even though the practice is common, the thermal effectiveness of the process is not commonly understood. In order for producers to easily understand the thermodynamics of hot oiling, a simple tool is needed for estimating downhole temperatures. Such a tool has been developed that was distributed as a compiled, public-domain-software spreadsheet. That spreadsheet has evolved into an interactive from on the World Wide Web and has been adapted into a Windows{trademark} program by Petrolite, St. Louis MO. The development of such a tools was facilitated by expressing downhole temperatures in terms of analytic formulas. Considerable algebraic work is required to develop such formulas. Also, the data describing hot oiling is customarily a mixture of practical units that must be converted to a consistent set of units. To facilitate the algebraic manipulations and to assure unit conversions are correct, during development parallel calculations were made using the spreadsheet and a symbolic mathematics program. Derivation of the formulas considered falling film flow in the annulus and started from the transient differential equations so that the effects of the heat capacity of the tubing and casing could be included. While this approach to developing a software product does not have the power and sophistication of a finite element or difference code, it produces a user friendly product that implements the equations solved with a minimum potential for bugs. This allows emphasis in development of the product to be placed on the physics.

Mansure, A.J. [Sandia National Labs., Albuquerque, NM (United States). Geothermal Research Dept.

1996-09-01

154

Hot air drum evaporator  

DOEpatents

An evaporation system for aqueous radioactive waste uses standard 30 and 55 gallon drums. Waste solutions form cascading water sprays as they pass over a number of trays arranged in a vertical stack within a drum. Hot dry air is circulated radially of the drum through the water sprays thereby removing water vapor. The system is encased in concrete to prevent exposure to radioactivity. The use of standard 30 and 55 gallon drums permits an inexpensive compact modular design that is readily disposable, thus eliminating maintenance and radiation build-up problems encountered with conventional evaporation systems.

Black, Roger L. (Idaho Falls, ID)

1981-01-01

155

Hot cell examination table  

DOEpatents

A table for use in a hot cell or similar controlled environment for use in examining specimens. The table has a movable table top that can be moved relative to a table frame. A shaft is fixedly mounted to the frame for axial rotation. A shaft traveler having a plurality of tilted rollers biased against the shaft is connected to the table top such that rotation of the shaft causes the shaft traveler to roll along the shaft. An electromagnetic drive is connected to the shaft and the frame for controllably rotating the shaft.

Gaal, Peter S. (Monroeville, PA); Ebejer, Lino P. (Weston, MA); Kareis, James H. (Slickville, PA); Schlegel, Gary L. (McKeesport, PA)

1991-01-01

156

Hot and Cold  

NSDL National Science Digital Library

In this activity, learners explore temperature changes from chemical reactions by mixing urea with water in one flask and mixing calcium chloride with water in another flask. They observe that the urea flask gets cold and the calcium chloride flask gets hot. The main idea is that some chemical processes release heat energy and are exothermic, while some chemical processes absorb heat energy and are endothermic. This activity is currently used in the Nature of Matter Unit in OMSI's Chemistry Lab. Cost estimates are per 100 learners.

Industry, Oregon M.

1997-01-01

157

Hot, Dry and Cloudy  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site] Click on the image for movie of Hot, Dry and Cloudy

This artist's concept shows a cloudy Jupiter-like planet that orbits very close to its fiery hot star. NASA's Spitzer Space Telescope was recently used to capture spectra, or molecular fingerprints, of two 'hot Jupiter' worlds like the one depicted here. This is the first time a spectrum has ever been obtained for an exoplanet, or a planet beyond our solar system.

The ground-breaking observations were made with Spitzer's spectrograph, which pries apart infrared light into its basic wavelengths, revealing the 'fingerprints' of molecules imprinted inside. Spitzer studied two planets, HD 209458b and HD 189733b, both of which were found, surprisingly, to have no water in the tops of their atmospheres. The results suggest that the hot planets are socked in with dry, high clouds, which are obscuring water that lies underneath. In addition, HD209458b showed hints of silicates, suggesting that the high clouds on that planet contain very fine sand-like particles.

Capturing the spectra from the two hot-Jupiter planets was no easy feat. The planets cannot be distinguished from their stars and instead appear to telescopes as single blurs of light. One way to get around this is through what is known as the secondary eclipse technique. In this method, changes in the total light from a so-called transiting planet system are measured as a planet is eclipsed by its star, vanishing from our Earthly point of view. The dip in observed light can then be attributed to the planet alone.

This technique, first used by Spitzer in 2005 to directly detect the light from an exoplanet, currently only works at infrared wavelengths, where the differences in brightness between the planet and star are less, and the planet's light is easier to pick out. For example, if the experiment had been done in visible light, the total light from the system would appear to be unchanged, even as the planet disappeared from view.

To capture spectra of the planets, Spitzer observed their secondary eclipses with its spectrograph. It took a spectrum of a star together with its planet, then, as the planet disappeared from view, a spectrum of just the star. By subtracting the spectrum of the star from the spectrum of the star and planet together, astronomers were able to determine the spectrum of the planet itself.

Neither of the parent stars for HD 209458b or HD 189733b can be seen with the naked eye. HD 209458b is located about 153 light-years away in the constellation Pegasus, while HD 189733b is about 62 light-years away in the constellation Vulpecula. Both planets zip around their stars in very tight orbits; HD 209458b circles once every 3.5 days, while HD 189733b orbits once every 2.2 days.

Of the approximately 200 known exoplanets, there are 12 besides HD 209458b and HD 189733b whose orbits are inclined in such a way that, from our point of view, they pass in front of their stars. At least three of these transiting exoplanets are bright enough to follow in the footsteps of HD 209458b and HD 189733 and reveal their infrared spectra to Spitzer. Astronomers hope to use Spitzer's spectrograph in the future to study HD 209458b and HD 189733b again in much greater detail, and to examine some of the other candidates for the first time.

2007-01-01

158

Rice University HOT WORK PERMIT  

E-print Network

, cutting, grinding, and soldering, thawing pipe, torch applied roofing, and welding. (References: 2000/operable. Hot Work equipment in good repair. Special precautions taken to avoid accidental operation

Natelson, Douglas

159

Hot toys are dead: long live hot products  

Microsoft Academic Search

Recalls the hot toys phenomenon of several past Christmases in the USA, such as for Cabbage Patch dolls and Power Rangers. Argues that such toys created headlines in order to gain publicity, but also that this trend appears to have died because of eBay: what made toys hot and a cultural event was their inaccessibility, but eBay makes them all

Christopher Byrne

2005-01-01

160

Full of Hot Air: Hot Air Balloon Building  

NSDL National Science Digital Library

In this activity, learners create a model of a hot air balloon using tissue paper and a hairdryer. Educators can use this activity to introduce learners to density and its role in why things float. This activity page features a fun how-to video that shows learners and educators how to make the hot air balloons.

Houston, Children'S M.

2010-01-01

161

Hot Planet - Cold Comfort  

NSDL National Science Digital Library

This page features videos from the "Hot Planet- Cold Comfort" television episode, related website articles and a student activity. The videos explore how the Gulf Stream conveyor belt may shut down; how Arctic river runoff and Alaskan glacial melt are freshening the oceans; and how ocean sediments and ice cores are being studied to understand the Little Ice Age. The videos total approximately one hour in length. The website articles explore the Little Ice Age; how the Arctic functions as a global thermostat, affecting global weather patterns; and great moments in climate change. The student activity is about light absorbtion. The site also contains a challenge activity to find details in a painting that depict Little Ice Age living conditions.

162

The Deep Hot Biosphere  

NASA Astrophysics Data System (ADS)

The first inhabitants of planet Earth were single-celled microorganisms and they are still with us today. Their name is truly legion, for they live everywhere, from boiling hot springs at the Earth's surface and on the seafloor to the coldest waters of the oceans and the Antarctic lakes. They are the masters of evolutionary adaptation, who have colonized the entire range of conditions under which water can exist as a liquid. At some ancient mythic time billions of years ago in a witches' brew of precursory molecules, somewhere, somehow, on a sunny Precambrian day bright with promise some of these molecules came together in the first coupling, learned to replicate, create enzymes, metabolize, and seal themselves into protective membranes inside of which they began the process of living. How they did this is our greatest mystery, for they are our primordial ancestors and we do not understand ourselves until we understand them.

Craig, Harmon

163

Thyroid 'hot' nodules  

PubMed Central

A retrospective analysis of thyroid scintiscanning at one hospital over a 3-year period revealed nineteen patients in whom a solitary, hyperfunctioning thyroid nodule was producing thyrotoxicosis. Most of the patients had clinical features referable to hyperthyroidism and in the majority a solitary nodule was palpable in the neck which was found to correlate well with the location of the ‘hot’ nodule on scanning. Cardiac failure was present in 21% and atrial fibrillation occurred in 37%. The 131I uptake by the thyroid was of little value in deciding whether or not the patient was toxic, but there was good agreement between serum protein bound iodine determinations and measurement of serum thyroxine and resin uptake tests. There appeared to be no relationship between the size of the nodule and its degree of activity. PMID:5079174

Ramsay, Ian; Richardson, P. J.; Marsden, Philip; McKerron, C. G.

1972-01-01

164

Green Systems Solar Hot Water  

E-print Network

Air Handlers Evaporative Cooling Tower (Trex enclosure) Storage tanks (underground) Heat Exchanger (HX Thermal Panels (Trex enclosure) Hot Water Storage Tank (TS-5; basement) Hot Water Heaters (HW-1-generation Unit (CHX-1; basement) Water Storage Tank (TS-3; basement) Provides electricity to building when solar

Schladow, S. Geoffrey

165

SOURCE ASSESSMENT: ASPHALT HOT MIX  

EPA Science Inventory

This report summarizes data on air emissions from the asphalt hot mix industry. A representative asphalt hot mix plant was defined, based on the results of an industrial survey, to assess the severity of emissions from this industry. Source severity was defined as the ratio of th...

166

Mammoth Hot Springs Online Tour  

NSDL National Science Digital Library

This Yellowstone National Park website offers an online tour of the Mammoth Hot Springs. Prominent hot springs and terraces are highlighted with photos and information concerning their cycles of activity. Similar tours of the Old Faithful area, the Norris Geyser Basin, the Fountain Paint Pots, and the Grand Canyon of Yellowstone are also available online.

Park, Yellowstone N.

167

Keep It Cool in Hot Weather  

MedlinePLUS

... in the Summer Sun Keep it Cool in Hot Weather Keep it Cool in Hot Weather Advice for Older People Applies to All ... factors that can increase risk include an extremely hot home, lack of transportation, overdressing and visiting overcrowded ...

168

Three-dimensional inversion of magnetotelluric data from the Coso Geothermal Field, based on a finite difference Gauss-Newton method parallelized on a multicore workstation  

NASA Astrophysics Data System (ADS)

An existing 3-D magnetotelluric (MT) inversion program written for a single processor personal computer (PC) has been modified and parallelized using OpenMP, in order to run the program efficiently on a multicore workstation. The program uses the Gauss-Newton inversion algorithm based on a staggered-grid finite-difference forward problem, requiring explicit calculation of the Frechet derivatives. The most time-consuming tasks are calculating the derivatives and determining the model parameters at each iteration. Forward modeling and derivative calculations are parallelized by assigning the calculations for each frequency to separate threads, which execute concurrently. Model parameters are obtained by factoring the Hessian using the LDLT method, implemented using a block-cyclic algorithm and compact storage. MT data from 102 tensor stations over the East Flank of the Coso Geothermal Field, California are inverted. Less than three days are required to invert the dataset for ˜ 55,000 inversion parameters on a 2.66 GHz 8-CPU PC with 16 GB of RAM. Inversion results, recovered from a halfspace rather than initial 2-D inversions, qualitatively resemble models from massively parallel 3-D inversion by other researchers and overall, exhibit an improved fit. A steeply west-dipping conductor under the western East Flank is tentatively correlated with a zone of high-temperature ionic fluids based on known well production and lost circulation intervals. Beneath the Main Field, vertical and north-trending shallow conductors are correlated with geothermal producing intervals as well.

Maris, Virginie

169

Temporal velocity variations beneath the Coso geothermal field observed using seismic double difference tomography of compressional and shear wave arrival times  

NASA Astrophysics Data System (ADS)

Microseismic imaging can be an important tool for characterizing geothermal reservoirs. Since microseismic sources occur more or less continuously due to the operations of a geothermal plant and the naturally occurring background seismicity, passive seismic monitoring is well suited for quantifying the temporal variations in reservoir properties that occur within the geothermal reservoir during production. In this study we will use microseismic data recorded between 1996 and 2008 to investigate the temporal variations in seismic velocity below the Coso geothermal field in California. In this study we will apply the double difference tomography method to simultaneously locate a suite of microseismic events and determine the compressional and shear wave velocity as well as their ratio. The double-difference method uses both absolute and relative arrival times of earthquakes measured at the same station, which allows a more precise determination of the relative locations of earthquakes. In particular, we apply a cross-correlation technique to improve the measurement of relative traveltimes. The large number of microearthquakes observed between 1996 and 2008 allows us to characterize subsurface velocity and to investigate changes in velocity that accompany production from the geothermal reservoir.

Seher, T.; Zhang, H.; Fehler, M. C.; Newman, G. A.

2011-12-01

170

Saturn's Hot Spot  

NASA Technical Reports Server (NTRS)

This is the sharpest image of Saturn's temperature emissions taken from the ground; it is a mosaic of 35 individual exposures made at the W.M. Keck I Observatory, Mauna Kea, Hawaii on Feb. 4, 2004.

The images to create this mosaic were taken with infrared radiation. The mosaic was taken at a wavelength near 17.65 microns and is sensitive to temperatures in Saturn's upper troposphere. The prominent hot spot at the bottom of the image is right at Saturn's south pole. The warming of the southern hemisphere was expected, as Saturn was just past southern summer solstice, but the abrupt changes in temperature with latitude were not expected. The tropospheric temperature increases toward the pole abruptly near 70 degrees latitude from 88 to 89 Kelvin (-301 to -299 degrees Fahrenheit) and then to 91 Kelvin (-296 degrees Fahrenheit) right at the pole.

Ring particles are not at a uniform temperature everywhere in their orbit around Saturn. The ring particles are orbiting clockwise in this image. Particles are coldest just after having cooled down in Saturn's shadow (lower left). As they orbit Saturn, the particles increase in temperature up to a maximum (lower right) just before passing behind Saturn again in shadow.

A small section of the ring image is missing because of incomplete mosaic coverage during the observing sequence.

2005-01-01

171

Solutions for Hot Situations  

NASA Technical Reports Server (NTRS)

From the company that brought the world an integral heating and cooling food service system after originally developing it for NASA's Apollo Program, comes yet another orbital offshoot: a product that can be as thin as paper and as strong as steel. Nextel Ceramic Textiles and Composites from 3M Company offer space-age protection and innovative solutions for hot situations, ranging from NASA to NASCAR. With superior thermal protection, Nextel fabrics, tape, and sleevings outperform other high temperature textiles such as aramids, carbon, glass, and quartz, permitting engineers and manufacturers to handle applications up to 2,500 F (1,371 C). The stiffness and strength of Nextel Continuous Ceramic Fibers make them a great match for improving the rigidity of aluminum in metal matrix composites. Moreover, the fibers demonstrate low shrinkage at operating temperatures, which allow for the manufacturing of a dimensionally stable product. These novel fibers also offer excellent chemical resistance, low thermal conductivity, thermal shock resistance, low porosity, and unique electrical properties.

2003-01-01

172

Neptune's 'Hot' South Pole  

NASA Technical Reports Server (NTRS)

These thermal images show a 'hot' south pole on the planet Neptune. These warmer temperatures provide an avenue for methane to escape out of the deep atmosphere.

The images were obtained with the Very Large Telescope in Chile, using an imager/spectrometer for mid-infrared wavelengths on Sept. 1 and 2, 2006. The telescope is operated by the European Organization for Astronomical Research in the Southern Hemisphere (known as ESO).

Scientists say Neptune's south pole is 'hotter' than anywhere else on the planet by about 10 degrees Celsius (50 degrees Fahrenheit). The average temperature on Neptune is about minus 200 degrees Celsius (minus 392 degrees Fahrenheit).

The upper left image samples temperatures near the top of Neptune's troposphere (near 100 millibar pressure, which is one-tenth the Earth atmospheric pressure at sea level). The hottest temperatures are indicated at the lower part of the image, at Neptune's south pole (see the graphic at the upper right). The lower two images, taken 6.3 hours apart, sample temperatures at higher altitudes in Neptune's stratosphere. They do show generally warmer temperatures near, but not at, the south pole. They also show a distinct warm area which can be seen in the lower left image and rotated completely around the back of the planet and returned to the earth-facing hemisphere in the lower right image.

2007-01-01

173

Really Hot Stars  

NASA Astrophysics Data System (ADS)

Spectacular VLT Photos Unveil Mysterious Nebulae Summary Quite a few of the most beautiful objects in the Universe are still shrouded in mystery. Even though most of the nebulae of gas and dust in our vicinity are now rather well understood, there are some which continue to puzzle astronomers. This is the case of a small number of unusual nebulae that appear to be the subject of strong heating - in astronomical terminology, they present an amazingly "high degree of excitation". This is because they contain significant amounts of ions, i.e., atoms that have lost one or more of their electrons. Depending on the atoms involved and the number of electrons lost, this process bears witness to the strength of the radiation or to the impact of energetic particles. But what are the sources of that excitation? Could it be energetic stars or perhaps some kind of exotic objects inside these nebulae? How do these peculiar objects fit into the current picture of universal evolution? New observations of a number of such unusual nebulae have recently been obtained with the Very Large Telescope (VLT) at the ESO Paranal Observatory (Chile). In a dedicated search for the origin of their individual characteristics, a team of astronomers - mostly from the Institute of Astrophysics & Geophysics in Liège (Belgium) [1] - have secured the first detailed, highly revealing images of four highly ionized nebulae in the Magellanic Clouds, two small satellite galaxies of our home galaxy, the Milky Way, only a few hundred thousand light-years away. In three nebulae, they succeeded in identifying the sources of energetic radiation and to eludicate their exceptional properties: some of the hottest, most massive stars ever seen, some of which are double. With masses of more than 20 times that of the Sun and surface temperatures above 90 000 degrees, these stars are truly extreme. PR Photo 09a/03: Nebula around the hot star AB7 in the SMC. PR Photo 09b/03: Nebula near the hot Wolf-Rayet star BAT99-2 in the LMC. PR Photo 09c/03: Nebula near the hot binary star BAT99-49 in the LMC. PR Photo 09d/03: The N44C Nebula in the LMC. Four unique images of highly excited nebulae in the Magellanic Clouds ESO PR Photo 09a/03 ESO PR Photo 09a/03 [Preview - JPEG: 400 x 472 pix - 74k [Normal - JPEG: 800 x 943 pix - 720k] [Full-Res - JPEG: 1200 x 1414 pix - 1.2M] ESO PR Photo 09b/03 ESO PR Photo 09b/03 [Preview - JPEG: 400 x 466 pix - 70k [Normal - JPEG: 800 x 931 pix - 928k] [Full-Res - JPEG: 1200 x 1397 pix - 1.8M] ESO PR Photo 09c/03 ESO PR Photo 09c/03 [Preview - JPEG: 400 x 469 pix - 74k [Normal - JPEG: 800 x 937 pix - 1.1M] [Full-Res - JPEG: 1200 x 1405 pix - 2.2M] ESO PR Photo 09d/03 ESO PR Photo 09d/03 [Preview - JPEG: 400 x 473 pix - 28k [Normal - JPEG: 800 x 945 pix - 368k] [Full-Res - JPEG: 1200 x 1418 pix - 600k] Captions: PR Photo 09a/03 is a reproduction of a "near-true" three-colour composite image of the highly excited nebula around the hot double star AB7 in the Small Magellanic Cloud (SMC), obtained in January 2002 with the FORS1 multi-mode instrument at the 8.2-m VLT MELIPAL telescope at the Paranal Observatory (Chile). It is based on three exposures through narrow-band optical (interference) filters that isolate the light from specific atoms and ions. In this rendering, the blue colour represents the light from singly ionized Helium (He II; wavelength 468.6 nm; exposure time 30 min), green corresponds to doubly ionized oxygen ([O III]; 495.7 + 500.7 nm; 5 min) and red to hydrogen atoms (H; H-alpha line at 656.2 nm; 5 min). Of these three ions, He II is the tracer of high excitation, i.e. the bluest areas of the nebula are the hottest. The sky field measures 400 x 400 arcsec2; the original pixel size on the 2k x 2k CCD is 0.23 arcsec. North is up and east to the left. Before combination, the CCD frames were flat-fielded and cleaned of cosmic-rays. Moreover, the stars in the blue (He II) image were removed in order to provide a clearer view of the surrounding nebular emission. The reproduced brightness is proportional to the squar

2003-04-01

174

Hot Spot Cosmic Accelerators  

NASA Astrophysics Data System (ADS)

The Universe is a violent place - as astronomers use increasingly sensitive means and methods to study the diverse processes out there, they become aware of the extraordinary forces acting in the space that surrounds us. With larger telescopes and ever-more sophisticated instruments, new information is gained about remote celestial objects and their behaviour. Among the most intriguing ones are the radio galaxies which emit prodiguous amounts of energy, in the form of fast-moving particles and intense electromagnetic radiation. One of these is known as 3C 445 ; it is located near the celestial equator within the zodiacal constellation Aquarius (The Waterman), at a distance of about 1 billion light-years. It most probably harbours a black hole at its centre, more massive than the one at the centre of our own galaxy, the Milky Way ( ESO PR 19/02 ). This galaxy was first observed from Cambridge (United Kingdom) in the 1950's and was listed as radio source no. 445 in the Third Cambridge Catalogue (1959), hence the name. Later observations revealed a strong outflow from this galaxy's active centre, visible on radio maps as two opposite plasma jets with strong synchrotron radiation ( [2]) originating from rapidly moving electrons in the associated magnetic field (image "a" in PR Photo 26/02 ). Now, a trio of European astronomers [1] have used two advanced instruments, ISAAC and FORS1 on the 8.2-m VLT ANTU telescope at the ESO Paranal Observatory (Chile) to obtain near-infrared images of these jets (images "b" and "c" in PR Photo 26/02 ). As can be clearly seen on the radio picture of 3C 445 obtained with the NRAO Very Large Array (VLA) radio facility ("a"), the plasma jets of fast particles emanating from the galaxy ram into the surrounding intergalactic medium (mostly primordial hydrogen), thereby producing two "shocks" , both at a distance of approximately 1.5 million light-years from the central galaxy and with particularly strong synchrotron emission. With a total length of more than 3 million light-years, or no less than one-and-a-half times the distance from the Milky Way to the Andromeda galaxy, this structure is indeed gigantic. The region where the jets collide with the intergalactic medium are known as " hot spots ". Superposing the intensity contours of the radio emission from the southern "hot spot" on a near-infrared J-band (wavelength 1.25 µm) VLT ISAAC image ("b") shows three distinct emitting areas; they are even better visible on the I-band (0.9 µm) FORS1 image ("c"). This emission is obviously associated with the shock front visible on the radio image. This is one of the first times it has been possible to obtain an optical/near-IR image of synchrotron emission from such an intergalactic shock and, thanks to the sensitivity and image sharpness of the VLT, the most detailed view of its kind so far . The central area (with the strongest emission) is where the plasma jet from the galaxy centre hits the intergalactic medium. The light from the two other "knots", some 10 - 15,000 light-years away from the central "hot spot", is also interpreted as synchrotron emission. However, in view of the large distance, the astronomers are convinced that it must be caused by electrons accelerated in secondary processes at those sites . The new images thus confirm that electrons are being continuously accelerated in these "knots" - hence called "cosmic accelerators" - far from the galaxy and the main jets, and in nearly empty space. The exact physical circumstances of this effect are not well known and will be the subject of further investigations. The present VLT-images of the "hot spots" near 3C 445 may not have the same public appeal as some of those beautiful images that have been produced by the same instruments during the past years. But they are not less valuable - their unusual importance is of a different kind, as they now herald the advent of fundamentally new insights into the

2002-11-01

175

Hot and super-hot hydrogen atoms in microwave plasma  

SciTech Connect

'Super-hot' (kinetic energy {approx}4-8 eV) and 'hot' (kinetic energy {approx}0.3 eV) H atoms were detected in a surface wave (500 MHz) generated H{sub 2} plasma column, at pressure p=0.01 mbar, from the analysis of the H{sub {beta}}, H{sub {gamma}}, H{sub {delta}}, and H{sub {epsilon}} emission line profiles. These profiles were found to evolve from single Gaussian to bi-Gaussian toward the plasma column end. Population inversion between the levels 5{yields}4 and 6{yields}4 was detected. At pressure p=0.2 mbar, super-hot atoms were not detected and the temperature of the hot atoms was found to increase with the upper level principal quantum number.

Tatarova, E.; Felizardo, E.; Dias, F. M.; Lino da Silva, M.; Ferreira, C. M. [Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, 1049-001 Lisboa (Portugal); Gordiets, B. [Lebedev Physics Institute, 11991 Moscow (Russian Federation)

2009-11-02

176

Hot Stars With Hot Jupiters Have High Obliquities  

E-print Network

We show that stars with transiting planets for which the stellar obliquity is large are preferentially hot (T [subscript eff] > 6250 K). This could explain why small obliquities were observed in the earliest measurements, ...

Winn, Joshua Nathan

177

Seismic response to power production at the Coso Geothermal field, south-eastern CA: using operational parameters and relocated events to study anthropogenic seismicity rates and reservoir scale tectonic structure  

NASA Astrophysics Data System (ADS)

The United States is increasing its dependence on renewable energies and with that has come an interest in expanding geothermal operations. Due to the proximity of many existing and potential geothermal sites to population centers and seismically active regions, it is important to understand how geothermal operations interact with local (and regional) seismicity, and to determine if seismicity rates are predictable from operational parameters (i.e. fluid injection, production, and net fluid extraction) alone. Furthermore, geothermal injection and production strategies can be improved by identifying, locating and characterizing related earthquakes within the tectonic related background seismicity. As the geothermal production related seismic source focal mechanisms, moment, and location are better characterized, important pragmatic questions (such as the improvement of injection strategies and 3-d thermohydromechanical model validation) and research issues (such as the relationship between far field seismic signals, local rheology changes, and native state reservoir stress evolution as a function of injection and production transients) can be more systematically addressed. We focus specifically on the 270 MW Coso geothermal field in south-eastern California, which is characterized by both high seismicity rates and relatively high aftershock triggering. After performing statistical de-clustering of local seismicity into background and aftershock rates, we show that the background rate (at both the Coso and Salton Sea geothermal fields) can be approximated during many time intervals at the 90% + confidence level by a linear combination of injection volume and the net extracted volume (difference between production and injection). Different magnitude ranges are sampled to determine if the response is constant with respect to magnitude. We also use relative relocations and focal mechanisms from Yang et al. (2012) to map fault planes within the Coso geothermal field. We use Bayesian S-wave picking of Coso borehole network microearthquake data and fully-nonlinear 3D hypocenter grid searches to obtain 18000+ well located hypocenters in the geothermal field. Coso geothermal seismicity is not diffuse; 87% of all the Coso geothermal hypocenters from 1996-2008 occur within 25 m of planes consistent with tectonic processes along the eastern California shear zone. 83% of the hypocenters associate with vertical and steeply-dipping conjugate N-NW dextral and NE sinistral strike slip planes, 12% of the earthquakes on normal-slip planes with dips of 35-70 degrees, and 5% of the events with reverse-oblique-slip on steeply-dipping planes. The non-diffuse nature of seismicity suggests that induced events occur preferentially on pre-existing structures and that flow is concentrated in fractures. With minimum horizontal stress oriented at 81 degrees, and no normal faults, in the western part of the field, and minimum horizontal stress of 106 degrees and pervasive normal faults in the eastern portion of the field (Roquemore, 1980; Blake and Davatzes, 2006), structures that are favorably oriented in the current stress field appear to be most commonly activated by geothermal operations.

Lajoie, L. J.; O'Connell, D. R.; Creed, R. J.; Brodsky, E. E.

2013-12-01

178

Red-Hot Saturn  

NASA Technical Reports Server (NTRS)

These side-by-side false-color images show Saturn's heat emission. The data were taken on Feb. 4, 2004, from the W. M. Keck I Observatory, Mauna Kea, Hawaii. Both images were taken with infrared radiation. The image on the left was taken at a wavelength near 17.65 microns and is sensitive to temperatures in Saturn's upper troposphere. The image on the right was taken at a wavelength of 8 microns and is sensitive to temperatures in Saturn's stratosphere. The prominent hot spot at the bottom of each image is at Saturn's south pole. The warming of the southern hemisphere was expected, as Saturn was just past southern summer solstice, but the abrupt changes in temperature with latitude were not expected.

The troposphere temperature increases toward the pole abruptly near 70 degrees latitude from 88 to 89 Kelvin (-301 to -299 degrees Fahrenheit) and then to 91 Kelvin (-296 degrees Fahrenheit) right at the pole. Near 70 degrees latitude, the stratospheric temperature increases even more abruptly from 146 to 150 Kelvin (-197 to -189 degrees Fahrenheit) and then again to 151 Kelvin (-188 degrees Fahrenheit) right at the pole.

While the rings are too faint to be detected at 8 microns (right), they show up at 17.65 microns. The ring particles are orbiting Saturn to the left on the bottom and to the right on the top. The lower left ring is colder than the lower right ring, because the particles are just moving out of Saturn's shadow where they have cooled off. As they orbit Saturn, they warm up to a maximum just before passing behind Saturn again in shadow.

2005-01-01

179

CCD Hot Pixel Annealing  

NASA Astrophysics Data System (ADS)

Hot pixel annealing will continue to be performed once every 4 weeks. The CCD TECswill be turned off and heaters will be activated to bring the detectortemperatures to about +20C. This state will be held for approximately6 hours, after which the heaters are turned off, the TECs turned on,and the CCDs returned to normal operating condition. To assess the effectiveness of the annealing, a bias and four dark images will be taken before and after the annealing procedure for both WFC and HRC.The HRC darks are taken in parallel with the WFC darks.The charge transfer efficiency {CTE} of the ACS CCD detectors declinesas damage due to on-orbit radiation exposure accumulates. This degradationhas been closely monitored at regular intervals, because it is likely todetermine the useful lifetime of the CCDs.We combine the annealling activity with the charge transfer efficiency monitoring and also merge into the routine dark image collection. To this end, the CTE monitoring exposures have been moved into this proposal . All the data for this program is acquired using internal targets {lamps} only,so all of the exposures should be taken during Earth occultation time{but not during SAA passages}.This program emulates the ACS pre-flight ground calibration and post-launchSMOV testing {program 8948}, so that results from each epoch can be directlycompared. Extended Pixel Edge Response {EPER} and First Pixel Response {FPR}data will be obtained over a range of signal levels for both theWide Field Channel {WFC}, and the High Resolution Channel {HRC}.

Cox, Colin

2005-07-01

180

CCD Hot Pixel Annealing  

NASA Astrophysics Data System (ADS)

Hot pixel annealing will continue to be performed once every 4 weeks. The CCD TECswill be turned off and heaters will be activated to bring the detectortemperatures to about +20C. This state will be held for approximately6 hours, after which the heaters are turned off, the TECs turned on,and the CCDs returned to normal operating condition. To assess the effectiveness of the annealing, a bias and four dark images will be taken before and after the annealing procedure for both WFC and HRC.The HRC darks are taken in parallel with the WFC darks.The charge transfer efficiency {CTE} of the ACS CCD detectors declinesas damage due to on-orbit radiation exposure accumulates. This degradationhas been closely monitored at regular intervals, because it is likely todetermine the useful lifetime of the CCDs.We combine the annealling activity with the charge transfer efficiency monitoring and also merge into the routine dark image collection. To this end, the CTE monitoring exposures have been moved into this proposal . All the data for this program is acquired using internal targets {lamps} only,so all of the exposures should be taken during Earth occultation time{but not during SAA passages}.This program emulates the ACS pre-flight ground calibration and post-launchSMOV testing {program 8948}, so that results from each epoch can be directlycompared. Extended Pixel Edge Response {EPER} and First Pixel Response {FPR}data will be obtained over a range of signal levels for both theWide Field Channel {WFC}, and the High Resolution Channel {HRC}.

Cox, Colin

2006-07-01

181

CCD Hot Pixel Annealing  

NASA Astrophysics Data System (ADS)

Hot pixel annealing will continue to be performed once every 4 weeks. The CCD TECs will be turned off and heaters will be activated to bring the detector temperatures to about +20C. This state will be held for approximately 12 hours, after which the heaters are turned off, the TECs turned on, and the CCDs returned to normal operating condition. To assess the effectiveness of the annealing, a bias and four dark images will be taken before and after the annealing procedure for both WFC and HRC. The HRC darks are taken in parallel with the WFC darks. The charge transfer efficiency {CTE} of the ACS CCD detectors declines as damage due to on-orbit radiation exposure accumulates. This degradation has been closely monitored at regular intervals, because it is likely to determine the useful lifetime of the CCDs. We will now combine the annealling activity with the charge transfer efficiency monitoring and also merge into the routine dark image collection. To this end, the CTE monitoring exposures have been moved into this proposal . All the data for this program is acquired using internal targets {lamps} only, so all of the exposures should be taken during Earth occultation time {but not during SAA passages}. This program emulates the ACS pre-flight ground calibration and post-launch SMOV testing {program 8948}, so that results from each epoch can be directly compared. Extended Pixel Edge Response {EPER} and First Pixel Response {FPR} data will be obtained over a range of signal levels for both the Wide Field Channel {WFC}, and the High Resolution Channel {HRC}.

Cox, Colin

2004-07-01

182

The decay of hot nuclei  

SciTech Connect

The formation of hot compound nuclei in intermediate-energy heavy ion reactions is discussed. The statistical decay of such compound nuclei is responsible for the abundant emission of complex fragments and high energy gamma rays. 43 refs., 23 figs.

Moretto, L.G.; Wozniak, G.J.

1988-11-01

183

Do scientists trace hot topics?  

NASA Astrophysics Data System (ADS)

Do scientists follow hot topics in their scientific investigations? In this paper, by performing analysis to papers published in the American Physical Society (APS) Physical Review journals, it is found that papers are more likely to be attracted by hot fields, where the hotness of a field is measured by the number of papers belonging to the field. This indicates that scientists generally do follow hot topics. However, there are qualitative differences among scientists from various countries, among research works regarding different number of authors, different number of affiliations and different number of references. These observations could be valuable for policy makers when deciding research funding and also for individual researchers when searching for scientific projects.

Wei, Tian; Li, Menghui; Wu, Chensheng; Yan, Xiao-Yong; Fan, Ying; di, Zengru; Wu, Jinshan

2013-07-01

184

Morpheus Lander Hot Fire Test  

NASA Video Gallery

This video shows a successful "hot fire" test of the Morpheus lander on February 27, 2012, at the VTB Flight Complex at NASA's Johnson Space Center. The engine burns for an extended period of time ...

185

Hot carrier diffusion in graphene  

E-print Network

We report an optical study of charge transport in graphene. Diffusion of hot carriers in epitaxial graphene and reduced graphene oxide samples are studied using an ultrafast pump-probe technique with a high spatial resolution. Spatiotemporal...

Ruzicka, Brian Andrew; Wang, Shuai; Werake, Lalani Kumari; Weintrub, Ben; Loh, Kian Ping; Zhao, Hui

2010-11-01

186

Do scientists trace hot topics?  

PubMed Central

Do scientists follow hot topics in their scientific investigations? In this paper, by performing analysis to papers published in the American Physical Society (APS) Physical Review journals, it is found that papers are more likely to be attracted by hot fields, where the hotness of a field is measured by the number of papers belonging to the field. This indicates that scientists generally do follow hot topics. However, there are qualitative differences among scientists from various countries, among research works regarding different number of authors, different number of affiliations and different number of references. These observations could be valuable for policy makers when deciding research funding and also for individual researchers when searching for scientific projects. PMID:23856680

Wei, Tian; Li, Menghui; Wu, Chensheng; Yan, Xiao-Yong; Fan, Ying; Di, Zengru; Wu, Jinshan

2013-01-01

187

MD Simulations of Hot Spots  

Microsoft Academic Search

The microscopic approach applied to shock-induced phenomena has often brought new understanding of the relevant physical and chemical processes. The interaction of a shock wave with pre-existing structural or chemical defects in a material can lead to the formation of hot spots, i.e. local regions of significant over heating. These hot spots play a key role in thermally activated processes

Jean-Bernard Maillet

2004-01-01

188

Hot spots in ammonium nitrate  

E-print Network

existing work on the topic and found a wide range of activation energies quoted for this process. This may be due to flawed kinetic models, or to the complexity of the sequence of reactions involved in AN decomposition. 1.2 Hot spots Hot spots are regions... possible without the assistance of others. Corporately, Orica Mining Services and the Atomic Weapons Establishment envisioned and funded the project. From Orica, Ian Kirby, Jim Chan, John Cooper and Richard Goodridge all provided useful support, insight...

Taylor, Nicholas

2011-07-12

189

Coping with Hot Work Environments  

E-print Network

evaporation. Wiping sweat from the skin with a cloth also prevents cooling from evaporation. In hot, humid conditions, hard work becomes harder. The sweat glands release moisture and essential David W. Smith, Extension Safety Program The Texas A... are placed at higher risk after progressive loss of body fluid and salt, loss of appetite and build-up of heat in work and living areas. Protect yourself and your workers by avoiding highly stressful activities during extended hot spells or performing...

Smith, David

2005-04-28

190

Atmospheric escape from hot Jupiters  

Microsoft Academic Search

The extra-solar planet HD 209458b has been found to have an extended atmosphere of escaping atomic hydrogen (Vidal-Madjar et al. 2003), suggesting that ``hot Jupiters'' closer to their parent stars could evaporate. Here we estimate the atmospheric escape (so called evaporation rate) from hot Jupiters and their corresponding life time against evaporation. The calculated evaporation rate of HD 209458b is

A. Lecavelier des Etangs; A. Vidal-Madjar; J. C. McConnell; G. Hébrard

2004-01-01

191

Hot Dark Matter in Cosmology  

E-print Network

Cosmological dark matter in the form of neutrinos with masses of up to a few electron volts is known as hot dark matter. After an historical review of the subject, this article considers constraints on hot dark matter from current data on neutrino oscillations and on cosmology. The atmospheric neutrino oscillation data imply a lower limit on the HDM contribution to the cosmological density $\\Omega_\

Joel R. Primack; Michael A. K. Gross

2000-07-12

192

Spectral Modeling Hot Star Winds  

E-print Network

Spectral Modeling of X-Rays from Hot Star Winds Emma Wollman Advisor: David Cohen #12;Hot Stars Massive Stars Early-type Stars HD 93129 A (O3) M = 94.8 M! L = 1.5e6 L! T = 7.4 T! R = 22.5 R! ·· Produce supernovaeProduce supernovae (neutron stars, black holes)(neutron stars, black holes) ·· Found near birth

Cohen, David

193

Review of hot flash diaries.  

PubMed

Currently, there is only 1 published hot flash diary. This diary rates hot flash severity according to 4 categories: mild, moderate, severe, and very severe. The descriptions of these 4 severity categories are located on a separate form from the main data form. For each 24-h period, subjects record the number of hot flashes experienced for each of the 4 severity categories either by recollection or from a separate data source on which hot flashes have been tallied. This diary has been validated but does not conform to the FDA and EMEA guidance for industry. After we observed a high percentage of subjects reporting confusion when using this 4-category diary, we constructed and used a hot flash diary containing 3 severity categories that offered real-time recording of hot flashes, contained all severity definitions on the principle data form and also conformed to the FDA and EMEA guidance for industry. We compare these 2 diaries here and provide a sample of the 3-category diary, which has not been formally validated but is considered valid by the FDA and EMEA in support of drug approval. Either diary is acceptable for use in clinical trials. PMID:22230663

Guttuso, Thomas; DiGrazio, Will J; Reddy, Sireesha Y

2012-03-01

194

Characteristics of Hot Spots for Solar Activity  

Microsoft Academic Search

Hot spots for solar flares are areas where energetic solar flares occur more frequently than other areas. Hot spots last for one to three solar cycles. Hot spots remain at the same regions on the sun in a rigidly rotating coordinate system, although they are not active continuously. Most statistically significant hot spot systems are the ones with synodic rotation

T. A. Bai

2010-01-01

195

Hot Alps (Invited)  

NASA Astrophysics Data System (ADS)

Although it is frequently assumed that crust of Alpine orogens is hot due to the occurrence of thick and young (hence radiogenic) crust, evidence on the thermal ranking of orogens is contradictory. Heat flow measurements from shallow wells (depth ? 1 km) in the Alps yield a relatively cold thermal regime of 50-80 mW/m2, but data are likely biased by meteoric cold-water circulation. Here we report on the spectral analysis of the aeromagnetic residuals of northern Italy to derive the Curie point depth (CPD), assumed to represent the 600°C isotherm depth. Airborne magnetics were acquired on whole Italy during the 1970s by the national oil company AGIP (now Eni). Data were gathered by several surveys carried out at 1000-13,300 feet (300-4000 m) altitude, with flight line spacing of 2-10 km. Surveys of the Alps and Po Plain (northern Italy) were obtained both with a line spacing of 5 km (and 5 km tie lines), at an altitude of 4000-5000 and 13,300 feet, respectively. To evaluate CPDs we used the centroid method (routinely adopted in recent CPD studies on East Asia and central-southern Europe) on 72 square windows of 100-110 km edge, with a 50% degree of superposition. CPDs vary between 16 and 38 km (22 km on average) in the Po Plain, located south of the Alps and representing the Adriatic-African foreland area. Conversely, the Alps yield very shallow CPDs, ranging between 6 and 15 km (10 km on average). CPDs fall systematically above local Moho depths, implying that magnetic source bottoms documented in this study do not represent a lithological boundary over non-magnetic peridotitic mantle, but can be safely associated with CPDs and the 600°C isotherm. CPDs from the Po Plain are in rough agreement with reported heat flow values of 25-60 mW/m2, and imply and average thermal conductivity (k) of the Po Plain crust of 1.5 W/m°K, at the lower bound of k values measured and inferred for the crust. Conversely, the average 10 km CPD documented in the Alps translates into heat flow values ranging from 90 to 150 mW/m2, if k values of 1.5 to 2.5 W/m°K (respectively) are assumed (the latter is average k value of the crust assumed for other world provinces, such as California). A ~150 mW/m2 heat flow value turns out to be similar to that observed in Tuscany and the Tyrrhenian Sea back-arc basin, as well as to values documented for active rifts and young oceans. Di Stefano et al. (2009) documented P wave velocities around 8 km/sec in the upper mantle of the Alps, suggesting the lack of shallow asthenosphere. Thus high heat flow of the Alps must be produced by radiogenic crust, instead of asthenospheric upwelling. A 600°C isotherm at ~10 km depth implies widespread melting at mid-lower crustal depths, considering the 60 km crustal thickness of the Alps. This is consistent with the very low P-wave velocities observed at 20-40 km depth beneath the chain by Di Stefano et al. (2009). When extrapolated to other orogens of the geological past, the thermal regime of the Alps may explain the extensive occurrence of intrusives exposed in eroded pre-Alpine orogens and cratons. Reference: Di Stefano, R., et al. (2009), J. Geophys. Res., 114, doi:10.1029/2008JB005641.

Speranza, F.; Minelli, L.; Pignatelli, A.; Gilardi, M.

2013-12-01

196

Miniature, Hygrometric Hot Flash Recorder  

PubMed Central

Objective To design and test a miniature ambulatory hot flash recorder which uses neither electrodes nor gel. Design In the first study, putative hot flashes recorded using a relative humidity (RH) sensor were compared to patient event marks. In the second study, RH recorded using a complete prototype recorder was compared to sternal skin conductance (SCL) recordings made on a Biolog recorder, as well as to event marks. Setting University medical center. Patients Ten healthy postmenopausal women reporting frequent hot flashes and using no medication. Interventions Body heating in laboratory. Main Outcome Measures Positive Predictive Value (PPV), sensitivity, specificity. Results In both laboratory studies, the PPV, sensitivity, and specificity among all 3 measures (RH, SCL, event) was 100%. In the field, an RH increase of 3%/min compared to SCL-detected hot flashes yielded a PPV of 95.6%, a specificity of 95.2%, and a sensitivity of 90.9%. Conclusions This device should be useful as an endpoint in clinical trials of treatments for hot flashes. PMID:17445808

Freedman, Robert R.; Wasson, Samuel

2007-01-01

197

Prometheus Hot Leg Piping Concept  

NASA Astrophysics Data System (ADS)

The Naval Reactors Prime Contractor Team (NRPCT) recommended the development of a gas cooled reactor directly coupled to a Brayton energy conversion system as the Space Nuclear Power Plant (SNPP) for NASA's Project Prometheus. The section of piping between the reactor outlet and turbine inlet, designated as the hot leg piping, required unique design features to allow the use of a nickel superalloy rather than a refractory metal as the pressure boundary. The NRPCT evaluated a variety of hot leg piping concepts for performance relative to SNPP system parameters, manufacturability, material considerations, and comparison to past high temperature gas reactor (HTGR) practice. Manufacturability challenges and the impact of pressure drop and turbine entrance temperature reduction on cycle efficiency were discriminators between the piping concepts. This paper summarizes the NRPCT hot leg piping evaluation, presents the concept recommended, and summarizes developmental issues for the recommended concept.

Gribik, Anastasia M.; DiLorenzo, Peter A.

2007-01-01

198

Aplastic anaemia with 'hot pockets'.  

PubMed

4 patients with chronic severe aplastic anaemia and with persistent foci of intense haematopoietic activity, so-called 'Hot Pockets', in their bone marrow were studied. In all patients the remainder of the bone marrow was morphologically and erythrokinetically hypoplastic. The cellular morphology in these 'Hot Pockets' displayed megaloblastic features and definite maturation abnormalities in erythroblasts, but no consistent changes in the myeloid or megakaryocytic series. The presence of persistent 'Hot Pockets' presents a conceptual challenge since these pockets contain multipotential stem cells capable of differentiation and self-renewal, but obviously incapable of repopulation of the bone marrow. In view of additional evidence for dyserythropoiesis in aplastic anaemia such as changes in erythroblast morphology and the production of macrocytes, fetal haemoglobin and complement sensitive cells, it seems likely that the bone marrow of aplastic anaemia patients is totally dyserythropoietic rather than hypoactive and that bone marrow transplantation in many cases may be both justified and necessary. PMID:1034334

Kansu, E; Erslev, A J

1976-11-01

199

Hot Gas Halos in Galaxies  

SciTech Connect

We use Chandra and XMM-Newton to study how the hot gas content in early-type galaxies varies with environment. We find that the L{sub X}-L{sub K} relationship is steeper for field galaxies than for comparable galaxies in groups and clusters. This suggests that internal processes such as supernovae driven winds or AGN feedback may expel hot gas from low mass field galaxies. Such mechanisms are less effective in groups and clusters where the presence of an intragroup or intracluster medium may confine outflowing material.

Mulchaey, John S. [Carnegie Observatories (United States); Jeltema, Tesla E. [UCO/Lick Observatories (United States)

2010-06-08

200

Hot conditioning equipment conceptual design report  

SciTech Connect

This report documents the conceptual design of the Hot Conditioning System Equipment. The Hot conditioning System will consist of two separate designs: the Hot Conditioning System Equipment; and the Hot Conditioning System Annex. The Hot Conditioning System Equipment Design includes the equipment such as ovens, vacuum pumps, inert gas delivery systems, etc.necessary to condition spent nuclear fuel currently in storage in the K Basins of the Hanford Site. The Hot Conditioning System Annex consists of the facility of house the Hot Conditioning System. The Hot Conditioning System will be housed in an annex to the Canister Storage Building. The Hot Conditioning System will consist of pits in the floor which contain ovens in which the spent nuclear will be conditioned prior to interim storage.

Bradshaw, F.W., Westinghouse Hanford

1996-08-06

201

Modeling a Hot Wheels Loop  

NSDL National Science Digital Library

In this activity a Tracker model is compared with a toy truck attempting to drive up and around a Hot Wheels vertical loop track. Three different videos show the truck entering the loop at different speeds. For related EJS models see Particle Motion On A Curve and Particle Motion On A Vertical Elliptical Loop. The zip file includes all three videos and pdf instructions.

Brown, Douglas

2012-01-31

202

Microsensor Hot-Film Anemometer  

NASA Technical Reports Server (NTRS)

Improved hot-film anemometer developed for making high-bandwidth turbulence measurements in moderate-enthalpy supersonic and hypersonic flows (e.g., NASP inlets and control surfaces, HSCT jet exhaust). Features include low thermal inertia, ruggedness, and reduced perturbation of flow.

Mcginley, Catherine B.; Stephens, Ralph; Hopson, Purnell; Bartlett, James E.; Sheplak, Mark; Spina, Eric F.

1995-01-01

203

Workability of Hot Mix Asphalt.  

National Technical Information Service (NTIS)

The term workability has been used to describe several properties related to the construction of hot mix asphalt (HMA). Workability in the field can be defined as a property that describes the ease with which a HMA can be placed, worked by hand, and compa...

J. M. Guidimettla, L. A. Cooley, E. R. Brown

2003-01-01

204

Iron Aluminide Hot Gas Filters  

Microsoft Academic Search

Currently, high temperature filter systems are in the demonstration phase with the first commercial scale hot filter systems being installed on integrated gasification combined cycle (IGCC) and pressurized fluid bed combustion cycle (PBFC) systems (70 MW). They are dependent on the development of durable and economic high temperature filter systems. These filters are mostly ceramic tubes or candles. Ceramic filter

J. Hurley; S. Brosious; M. Johnson

1996-01-01

205

Upside's Hot 100 Awards: 1999  

NSDL National Science Digital Library

The business technology magazine Upside Today authors this list of the "hottest private high-tech companies of 1999." Upside editors considered entrepreneurial passion as well as the "staying power" of companies to be top criteria for the Hot 100 Awards. Each listing includes a company profile with homepage links where available.

206

Hot, Cold, and Really Cold.  

ERIC Educational Resources Information Center

Describes a physics experiment investigating temperature prediction and the relationship between the physical properties of heat units, melting, dissolving, states of matter, and energy loss. Details the experimental setup, which requires hot and cold water, a thermometer, and ice. Notes that the experiment employs a deliberate counter-intuitive…

Leyden, Michael

1997-01-01

207

Hot Issues at Community Colleges  

NSDL National Science Digital Library

The issues listed on this website are a reflection of AACC's strategic action areas. Their intent is to provide users with a cross-section of important issues surrounding community colleges. These issues will change as the scope and intensity of these issues change. Browse through the list of "hot issues" affecting community colleges today.

2010-06-09

208

Enriching the hot circumgalactic medium  

NASA Astrophysics Data System (ADS)

Simple models of galaxy formation in a cold dark matter universe predict that massive galaxies are surrounded by a hot, quasi-hydrostatic circumgalactic corona of slowly cooling gas, predominantly accreted from the intergalactic medium (IGM). This prediction is borne out by the recent cosmological hydrodynamical simulations of Crain et al., which reproduce observed scaling relations between the X-ray and optical properties of nearby disc galaxies. Such coronae are metal poor, but observations of the X-ray emitting circumgalactic medium (CGM) of local galaxies typically indicate enrichment to near-solar iron abundance, potentially signalling a shortcoming in current models of galaxy formation. We show here that, while the hot CGM of galaxies formed in the simulations is typically metal poor in a mass-weighted sense, its X-ray luminosity-weighted metallicity is often close to solar. This bias arises because the soft X-ray emissivity of a typical ˜0.1 keV corona is dominated by collisionally excited metal ions that are synthesized in stars and recycled into the hot CGM. We find that these metals are ejected primarily by stars that form in situ to the main progenitor of the galaxy, rather than in satellites or external galaxies. The enrichment of the hot CGM therefore proceeds in an `inside-out' fashion throughout the assembly of the galaxy: metals are transported from the central galaxy by supernova-driven winds and convection over several Gyr, establishing a strong negative radial metallicity gradient. Whilst metal ions synthesized by stars are necessary to produce the X-ray emissivity that enables the hot CGM of isolated galaxies to be detected with current instrumentation, the electrons that collisionally excite them are equally important. Since our simulations indicate that the electron density of hot coronae is dominated by the metal-poor gas accreted from the IGM, we infer that the hot CGM observed via X-ray emission is the outcome of both hierarchical accretion and stellar recycling.

Crain, Robert A.; McCarthy, Ian G.; Schaye, Joop; Theuns, Tom; Frenk, Carlos S.

2013-07-01

209

HOT Lane Policies and Their Implications  

E-print Network

projects, there is great diversity in terms of HOT lane design and operations. With HOT lane implementation there are many issues, including: toll rates, vehicle occupancy requirement, number of access points, and safety. This research examined (i...

Goel, Rahul

2011-08-08

210

Hyperthermia: Too Hot for Your Health  

MedlinePLUS

... Calvin | (301) 496-1752 | nianews3@mail.nih.gov Hot summer weather can pose special health risks to ... places and not understanding how to respond to hot weather conditions. Older people, particularly those with chronic ...

211

Is Coffee Aggravating Your Hot Flashes?  

MedlinePLUS

... page, please enable JavaScript. Is Coffee Aggravating Your Hot Flashes? Researchers suggest women skip caffeine if they' ... 2014 (HealthDay News) -- Drinking caffeine may worsen the hot flashes and night sweats that affect roughly two- ...

212

[Hygienic aspects of the hot water supply].  

PubMed

Hygienic significance of hot water-supply was demonstrated. In the case of the sanitary inspection deficiency it may be the complaints appearance. Hygiene of hot water-supply seems as an independent scientific branch of hygiene. PMID:1937089

Dergacheva, T S

1991-08-01

213

Geothermal hot water recovery process and system  

Microsoft Academic Search

An improved process and system for recovering high-temperature hot water ; from a geothermal supply is described. Equipment is described for reducing the ; pressure at the well head, flashing the hot water to steam to elevate a two-phase ; mixture of steam and hot water through the casing aasembly. Such flashing is ; accompanied by the evolution of substantially

Kuwada

1974-01-01

214

Diamond film by hot filament CVD method  

NASA Technical Reports Server (NTRS)

Diamond synthesis by the hot filament CVD method is discussed. A hot filament decomposes gas mixtures and oxygen containing organic compounds such as alcohols. which are carbon sources. The resulting thin films, growth mechanisms, and characteristics and problems associated with the hot filament CVD method are analyzed and evaluated.

Hirose, Y.

1988-01-01

215

Hot atom chemistry and radiopharmaceuticals  

SciTech Connect

The chemical products made in a cyclotron target are a combined result of the chemical effects of the nuclear transformation that made the radioactive atom and the bulk radiolysis in the target. This review uses some well-known examples to understand how hot atom chemistry explains the primary products from a nuclear reaction and then how radiation chemistry is exploited to set up the optimal product for radiosynthesis. It also addresses the chemical effects of nuclear decay. There are important principles that are common to hot atom chemistry and radiopharmaceutical chemistry. Both emphasize short-lived radionuclides and manipulation of high specific activity nuclides. Furthermore, they both rely on radiochromatographic separation for identification of no-carrieradded products.

Krohn, Kenneth A.; Moerlein, Stephen M.; Link, Jeanne M.; Welch, Michael J. [University of Washington, Department of Radiology, Molecular Imaging Center, 1959 NE Pacific St., Box 356004, Seattle, WA 98195-6004 (United States); Washington University, Department of Radiology, Division of Radiological Sciences, 510 South Kingshighway, St. Louis, MO 63110 (United States); University of Washington, Department of Radiology, Molecular Imaging Center, 1959 NE Pacific St., Box 356004, Seattle, WA 98195-6004 (United States); Washington University, Department of Radiology, Division of Radiological Sciences, 510 South Kingshighway, St. Louis, MO 63110 (United States)

2012-12-19

216

Solar hot water heating system  

SciTech Connect

A solar hot water heating system is provided with solar collectors connected to a hot water storage tank with a recirculating pump to circulate the cooler water in the storage tank through the collector to absorb heat therefrom and to be returned to the storage tank. A plurality of temperature sensors are placed throughout the system to monitor various temperatures and to develop control signals for energizing or de-energizing the recirculating pump, for opening and closing solenoid valves to isolate the solar collectors from the storage tank and for opening and closing solenoid valves to permit supply water to circulate at a predetermined rate through the solar collectors. The storage tank is provided with inlet and outlet stratifier tubes which, while permitting water to be fed into and withdrawn from the tank, produces stratification of the water stored within the tank and increases the overall efficiency of the system.

Budzynski, J. V.; James, D. A.

1981-02-03

217

Noise Generation in Hot Jets  

NASA Technical Reports Server (NTRS)

A prediction method based on the generalized acoustic analogy is presented, and used to evaluate aerodynamic noise radiated from high speed hot jets. The set of Euler equations are split into their respective non-radiating and residual components. Under certain conditions, the residual equations are rearranged to form a wave equation. This equation consists of a third-order wave operator, plus a number of nonlinear terms that are identified with the equivalent sources of sound and their statistical characteristics are modeled. A specialized RANS solver provides the base flow as well as turbulence quantities and temperature fluctuations that determine the source strength. The main objective here is to evaluate the relative contribution from various source elements to the far-field spectra and to show the significance of temperature fluctuations as a source of aerodynamic noise in hot jets.

Khavaran, Abbas; Kenzakowski, Donald C.

2007-01-01

218

Hot atom chemistry and radiopharmaceuticals  

NASA Astrophysics Data System (ADS)

The chemical products made in a cyclotron target are a combined result of the chemical effects of the nuclear transformation that made the radioactive atom and the bulk radiolysis in the target. This review uses some well-known examples to understand how hot atom chemistry explains the primary products from a nuclear reaction and then how radiation chemistry is exploited to set up the optimal product for radiosynthesis. It also addresses the chemical effects of nuclear decay. There are important principles that are common to hot atom chemistry and radiopharmaceutical chemistry. Both emphasize short-lived radionuclides and manipulation of high specific activity nuclides. Furthermore, they both rely on radiochromatographic separation for identification of no-carrieradded products.

Krohn, Kenneth A.; Moerlein, Stephen M.; Link, Jeanne M.; Welch, Michael J.

2012-12-01

219

Hot isostatic pressing of ceramics  

NASA Technical Reports Server (NTRS)

A mixture containing glass 70 to 95 and BN or B4C powder (0.1-10 microns) 5 to 30 vol. % is used as a secondary pressure medium in hot isostatic pressing of ceramics. Thus, Pyrex beads were mixed with 15% vol. BN powder (average diameter 2 microns), fused at 1400 deg for 2 h, cooled, crushed, and put into a graphite crucible. A Si3N4 sintered body was embedded in the powder, heated in vacuum at 1200 deg for 2 h, treated in a hot isostatic press furnace at 1700 deg and 1000 atm. for 1 h, and cooled to give a Si3N4 ceramic. It was easily separated from the crucible.

Honma, K.

1985-01-01

220

Lightning Hot Spots in Canada  

NSDL National Science Digital Library

Developed by the Meteorological Service of Canada, this Web site is devoted to lightning phenomena. Occurring 2.7 million times a year in Canada, visitors can find maps of Hot Spots and of current Lightning Activity over Canada. Educators and students can obtain lots of materials dealing with lightning properties, occurrences, and destructive capabilities. The site provides information on lightning activity differences among various geographic regions in Canada. Families can benefit from the high-quality and thorough, Lightning Safety Tips.

221

Infrared photometry of hot stars  

Microsoft Academic Search

A filter-wheel IR photometer is described which operates in the spectral range from 2 to 24 microns and is equipped with a liquid-helium-cooled germanium bolometer. Observations with this photometer of several X-ray binaries and hot stars are reported, and the data analysis technique is discussed. The systems and stars observed include Gamma Cas, X Per, Phi Per, Zeta Tau, HDE

M. Ferrari-Toniolo; O. Leonetti; P. Persi; G. Spada; R. Viotti

1978-01-01

222

Hot gas engine heater head  

DOEpatents

A heater head for a multi-cylinder double acting hot gas engine in which each cylinder is surrounded by an annular regenerator unit, and in which the tops of each cylinder and its surrounding regenerator are interconnected by a multiplicity of heater tubes. A manifold for the heater tubes has a centrally disposed duct connected to the top of the cylinder and surrounded by a wider duct connecting the other ends of the heater tubes with the regenerator unit.

Berntell, John O. (Staffanstorp, SE)

1983-01-01

223

Silicon Hot-Electron Bolometers  

NASA Technical Reports Server (NTRS)

We discuss a new type of direct detector, a silicon hot-electron bolometer, for measurements in the far-infrared and submillimeter spectral ranges. High performance bolometers can be made using the electron-phonon conductance in heavily doped silicon to provide thermal isolation from the cryogenic bath. Noise performance is expected to be near thermodynamic limits, allowing background limited performance for many far infrared and submillimeter photometric and spectroscopic applications.

Stevenson, Thomas R.; Hsieh, Wen-Ting; Mitchell, Robert R.; Isenberg, Hal D.; Stahle, Carl M.; Cao, Nga T.; Schneider, Gideon; Travers, Douglas E.; Moseley, S. Harvey; Wollack, Edward J.

2004-01-01

224

Cool systems for hot cities  

Microsoft Academic Search

On a hot summer day, Los Angeles, CA, like Baltimore, MD, Phoenix, AZ, Washington, D.C., and Tokyo, Japan, is c. 6-8 degrees F hotter than its surrounding areas. Dark buildings and pavement have replaced urban vegetation in these cities, absorbing more solar heat. The urban heat islands that are created result in increased air-conditioning costs, energy use, and pollution. Scientists

Hashem Akbari; Sarah Bretz

1998-01-01

225

ADVANCED HOT GAS FILTER DEVELOPMENT  

Microsoft Academic Search

DuPont Lanxide Composites, Inc. undertook a sixty-month program, under DOE Contract DEAC21-94MC31214, in order to develop hot gas candle filters from a patented material technology know as PRD-66. The goal of this program was to extend the development of this material as a filter element and fully assess the capability of this technology to meet the needs of Pressurized Fluidized

E. S. Connolly; G. D. Forsythe

2000-01-01

226

Hot atoms in cosmic chemistry.  

PubMed

High energy chemical reactions and atom molecule interactions might be important for cosmic chemistry with respect to the accelerated species in solar wind, cosmic rays, colliding gas and dust clouds and secondary knock-on particles in solids. "Hot" atoms with energies ranging from a few eV to some MeV can be generated via nuclear reactions and consequent recoil processes. The chemical fate of the radioactive atoms can be followed by radiochemical methods (radio GC or HPLC). Hot atom chemistry may serve for laboratory simulation of the reactions of energetic species with gaseous or solid interstellar matter. Due to the effective measurement of 10(8)-10(10) atoms only it covers a low to medium dose regime and may add to the studies of ion implantation which due to the optical methods applied are necessarily in the high dose regime. Experimental results are given for the systems: C/H2O (gas), C/H2O (solid, 77 K), N/CH4 (solid, 77K) and C/NH3 (solid, 77 K). Nuclear reactions used for the generation of 2 to 3 MeV atoms are: N(p,alpha) 11C, 16O(p,alpha pn) 11C and 12C(d,n) 13N with 8 to 45 MeV protons or deuterons from a cyclotron. Typical reactions products are: CO, CO2, CH4, CH2O, CH3OH, HCOOH, NH3, CH3NH2, cyanamide, formamidine, guanidine etc. Products of hot reactions in solids are more complex than in corresponding gaseous systems, which underlines the importance of solid state reactions for the build-up of precursors for biomolecules in space. As one of the major mechanisms for product formation, the simultaneous or fast consecutive reactions of a hot carbon with two target molecules (reaction complex) is discussed. PMID:11537799

Rossler, K; Jung, H J; Nebeling, B

1984-01-01

227

Hot and Cold Ideal Gases  

NSDL National Science Digital Library

The EJS Hot and Cold Ideal Gases model simulates the mixing of hot and cold two-dimensional ideal gases in a square box. This simulation can be used as part of the activity described in "The Statistical Interpretation of Entropy: An Activity" by Todd Timberlake, to be published in The Physics Teacher. In the model, one gas is initially confined to the left side of the box while the other gas is confined to the right side. An animation window shows the motion of the particles in the box, while an optional graph window plots the temperature of each side of the box, which is determined by measuring the average KE of the particles on each side. The initial number of particles and temperature on each side of the square can be changed and a button allows the user to reverse the particle velocities at any time. The user can modify this simulation if EJS is installed locally by right-clicking within the plot and selecting "Open Ejs Model" from the pop-up menu item. EJS Hot and Cold Ideal Gases model was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_entropy_HotAndColdIdealGases.jar file will run the program if Java is installed. EJS is a part of the Open Source Physics Project and is designed to make it easier to access, modify, and generate computer models. Additional EJS models are available. They can be found by searching ComPADRE for Open Source Physics, OSP, or EJS.

Timberlake, Todd

2010-07-01

228

Adiabatic radiant hot air burner  

Microsoft Academic Search

The report describes a low emissions hot air system for direct product drying and environmental heating. Specific emissions target were 0.5 ppm of nitrogen oxides (NO(x)) and 3.0 ppm of carbon monoxide (CO), as measured in the vitiated stream (mixed process air and combustion products). The firing rate turndown target was 50:1 and temperature range target was 200-1600 F.

R. K. Tidball; B. N. Marshall; F. E. Moreno; R. L. Pam

1992-01-01

229

Hot Gas Desulfurization PDU Project  

SciTech Connect

The process development unit (PDU) being constructed at METC will fill the strategic role of bridging the gap between post/current small-scale testing and future large-scale demonstrations. With the capability for both fluid-bed and transport reactor contacting, the project will provide a site for testing/proving hot gas desulfurization (HGD) process configurations and demonstrating sorbent suitability. Process conditions will be representative of anticipated commercial applications in terms of temperatures, pressures, compositions, velocities, and sorbent cycling.

Bissett, L.A.

1996-12-31

230

WISE Discovers Hyperluminous Hot DOGs  

NASA Astrophysics Data System (ADS)

One of the primary science objectives for NASA's Wide-field Infrared Survey Explorer (WISE) is to find the most luminous galaxies in the Universe. We have used WISE photometry to select an extraordinary all-sky sample of galaxies, which are prominent at 12 microns (W3) or 22 microns (W4), but faint or undetected at 3.4 microns (W1) and 4.6 microns (W2). Follow-up observations reveal that most of these galaxies are at redshift > 1.5, that they are hyperluminous (> 10^13 Lsun; with ~10% exceeding 10^14 Lsun, comparable to the most luminous optical QSOs). The follow-up observations also show that they are at least twice as hot as other types of infrared luminous galaxies, so that they are hot dust-obscured-galaxies, or Hot DOGs. Their SEDs have a very high mid-IR to submillimeter luminosity ratio, which is quite different from any existing galaxy templates. They may represent a rare, new phase in the galaxy evolution, possibly hosting extremely powerful super massive black holes.

Eisenhardt, Peter R.; Wu, J.; WISE Team

2013-01-01

231

Cool Stars in Hot Places  

E-print Network

During the last three decades, evidence has mounted that star and planet formation is not an isolated process, but is influenced by current and previous generations of stars. Although cool stars form in a range of environments, from isolated globules to rich embedded clusters, the influences of other stars on cool star and planet formation may be most significant in embedded clusters, where hundreds to thousands of cool stars form in close proximity to OB stars. At the cool stars 14 meeting, a splinter session was convened to discuss the role of environment in the formation of cool stars and planetary systems; with an emphasis on the ``hot'' environment found in rich clusters. We review here the basic results, ideas and questions presented at the session. We have organized this contribution into five basic questions: what is the typical environment of cool star formation, what role do hot star play in cool star formation, what role does environment play in planet formation, what is the role of hot star winds and supernovae, and what was the formation environment of the Sun? The intention is to review progress made in addressing each question, and to underscore areas of agreement and contention.

S. T. Megeath; E. Gaidos; J. J. Hester; F. C. Adams; J. Bally; J. -E. Lee; S. Wolk

2007-04-08

232

Community analysis of a mercury hot spring supports occurrence of domain-specific forms of mercuric reductase.  

PubMed

Mercury is a redox-active heavy metal that reacts with active thiols and depletes cellular antioxidants. Active resistance to the mercuric ion is a widely distributed trait among bacteria and results from the action of mercuric reductase (MerA). Protein phylogenetic analysis of MerA in bacteria indicated the occurrence of a second distinctive form of MerA among the archaea, which lacked an N-terminal metal recruitment domain and a C-terminal active tyrosine. To assess the distribution of the forms of MerA in an interacting community comprising members of both prokaryotic domains, studies were conducted at a naturally occurring mercury-rich geothermal environment. Geochemical analyses of Coso Hot Springs indicated that mercury ore (cinnabar) was present at concentrations of parts per thousand. Under high-temperature and acid conditions, cinnabar may be oxidized to the toxic form Hg2+, necessitating mercury resistance in resident prokaryotes. Culture-independent analysis combined with culture-based methods indicated the presence of thermophilic crenarchaeal and gram-positive bacterial taxa. Fluorescence in situ hybridization analysis provided quantitative data for community composition. DNA sequence analysis of archaeal and bacterial merA sequences derived from cultured pool isolates and from community DNA supported the hypothesis that both forms of MerA were present. Competition experiments were performed to assess the role of archaeal merA in biological fitness. An essential role for this protein was evident during growth in a mercury-contaminated environment. Despite environmental selection for mercury resistance and the proximity of community members, MerA retains the two distinct prokaryotic forms and avoids genetic homogenization. PMID:16332880

Simbahan, Jessica; Kurth, Elizabeth; Schelert, James; Dillman, Amanda; Moriyama, Etsuko; Jovanovich, Stevan; Blum, Paul

2005-12-01

233

Community Analysis of a Mercury Hot Spring Supports Occurrence of Domain-Specific Forms of Mercuric Reductase  

PubMed Central

Mercury is a redox-active heavy metal that reacts with active thiols and depletes cellular antioxidants. Active resistance to the mercuric ion is a widely distributed trait among bacteria and results from the action of mercuric reductase (MerA). Protein phylogenetic analysis of MerA in bacteria indicated the occurrence of a second distinctive form of MerA among the archaea, which lacked an N-terminal metal recruitment domain and a C-terminal active tyrosine. To assess the distribution of the forms of MerA in an interacting community comprising members of both prokaryotic domains, studies were conducted at a naturally occurring mercury-rich geothermal environment. Geochemical analyses of Coso Hot Springs indicated that mercury ore (cinnabar) was present at concentrations of parts per thousand. Under high-temperature and acid conditions, cinnabar may be oxidized to the toxic form Hg2+, necessitating mercury resistance in resident prokaryotes. Culture-independent analysis combined with culture-based methods indicated the presence of thermophilic crenarchaeal and gram-positive bacterial taxa. Fluorescence in situ hybridization analysis provided quantitative data for community composition. DNA sequence analysis of archaeal and bacterial merA sequences derived from cultured pool isolates and from community DNA supported the hypothesis that both forms of MerA were present. Competition experiments were performed to assess the role of archaeal merA in biological fitness. An essential role for this protein was evident during growth in a mercury-contaminated environment. Despite environmental selection for mercury resistance and the proximity of community members, MerA retains the two distinct prokaryotic forms and avoids genetic homogenization. PMID:16332880

Simbahan, Jessica; Kurth, Elizabeth; Schelert, James; Dillman, Amanda; Moriyama, Etsuko; Jovanovich, Stevan; Blum, Paul

2005-01-01

234

Hot Springs Metropolitan Planning Organization 2030 Long Range Transportation Plan  

E-print Network

Hot Springs Area Metropolitan Planning Organization 100 Broadway Terrace Hot Springs, Arkansas 71901 Adopted November 3, 2005 HSA-MPO 2030 LRTPii Participating Agencies Garland County Hot... Spring County City of Hot Springs City of Mountain Pine Hot Springs Village The Greater Hot Springs Chamber of Commerce The Arkansas State Highway and Transportation Department In Cooperation With United States Department of Transportation...

Hot Springs Metropolitan Planning Organization

2005-11-03

235

The geometric relationship between hot spots and seamounts: implications for Pacific hot spots  

NASA Astrophysics Data System (ADS)

Hot spots and the seamounts produced by them provide both geometric and temporal evidence for changes in absolute plate motion. The main limitation in using hot-spot-produced seamounts in plate tectonic reconstructions arises from the multiple sources of error and ambiguity that plague radiometric age estimates. In particular, unless the hot spot has maintained a steady and voluminous flux rate over long periods of time, the exact location of a hot spot (which represents the zero age origin along the hot spot trail) is poorly known. Here, we discuss a unique geometric relationship between a hot spot and the seamounts produced by it that we recently have discovered, i.e. hot-spot-produced seamounts have seafloor crustal flow lines that intersect at the hot spot location. Furthermore, we obtain images of cumulative volcano amplitudes (CVA) by convolving seamount shapes with their flow lines; hot spots correspond to clear local maxima in this image and the amplitudes are proportional to cumulative hot spot flux. This technique, dubbed `hot-spotting', allows us to determine hot spot locations based only on a set of seamount locations; no age information is required. We use the hot-spotting technique to examine the Pacific plate hot spots in general and the Bowie and Cobb hot spots in the Gulf of Alaska, in particular. We find that the Hawaii, Louisville, Caroline, Cobb, and Bowie hot spots have clear representations in the CVA images, Rurutu and/or Rarotonga are close to a large CVA high, while the other French Polynesian hot spots in general exhibit a much more subdued and blurred expression. We also conclude that the Cobb hot-spot plume may have been entrained by the Juan de Fuca Ridge about 2 Ma ago, or, alternatively, is in a waning phase and cannot penetrate Juan de Fuca plate lithosphere. The Bowie hot spot appears to have encountered the ridge more recently.

Wessel, Paul; Kroenke, Loren W.

1998-05-01

236

"Hotness" stability of chicken hot-wing products as affected by preparation methods and storage.  

PubMed

Chicken hot-drumettes containing 2% cayenne pepper were prepared using three different cooking methods and stored under two different temperatures for "hotness" evaluation. Results demonstrated that the hotness of the samples were highest when products were cooked in a microwave oven, followed by convection oven, and least hot by deep-fat frying. Regardless of the cooking method, the degree of hotness of the hot-drumette decreased drastically during refrigerated storage. Results also indicated that the loss of hotness was associated with the increase of 2-thiobarbituric acid (TBA) values in the product. The addition of antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), rosemary, and sodium nitrate during preparation or vacuum packaging retarded lipid oxidation of chicken hot-drumettes and retarded the loss of hotness of the products during refrigerated storage. PMID:9565248

Chang, M H; Chen, T C

1998-04-01

237

Hot Flow Anomalies at Venus  

NASA Technical Reports Server (NTRS)

We present a multi-instrument study of a hot flow anomaly (HFA) observed by the Venus Express spacecraft in the Venusian foreshock, on 22 March 2008, incorporating both Venus Express Magnetometer and Analyzer of Space Plasmas and Energetic Atoms (ASPERA) plasma observations. Centered on an interplanetary magnetic field discontinuity with inward convective motional electric fields on both sides, with a decreased core field strength, ion observations consistent with a flow deflection, and bounded by compressive heated edges, the properties of this event are consistent with those of HFAs observed at other planets within the solar system.

Collinson, G. A.; Sibeck, David Gary; Boardsen, Scott A.; Moore, Tom; Barabash, S.; Masters, A.; Shane, N.; Slavin, J.A.; Coates, A.J.; Zhang, T. L.; Sarantos, M.

2012-01-01

238

That's Hot! Robot Brain Programming  

NSDL National Science Digital Library

With the challenge to program computers to mimic the human reaction after touching a hot object, students program LEGO® robots to "react" and move back quickly once their touch sensors bump into something. By relating human senses to electronic sensors used in robots, students see the similarities between the human brain and its engineering counterpart, the computer, and come to better understand the functioning of sensors in both applications. They apply an understanding of the human "stimulus-sensor-coordinator-effector-response" framework to logically understand human and robot actions.

GK-12 Program, Computational Neurobiology Center, College of Engineering,

239

Image Storage in Hot Vapors  

E-print Network

We theoretically investigate image propagation and storage in hot atomic vapor. A $4f$ system is adopted for imaging and an atomic vapor cell is placed over the transform plane. The Fraunhofer diffraction pattern of an object in the object plane can thus be transformed into atomic Raman coherence according to the idea of ``light storage''. We investigate how the stored diffraction pattern evolves under diffusion. Our result indicates, under appropriate conditions, that an image can be reconstructed with high fidelity. The main reason for this procedure to work is the fact that diffusion of opposite-phase components of the diffraction pattern interfere destructively.

L. Zhao; T. Wang; Y. Xiao; S. F. Yelin

2007-10-22

240

A Strong Hot Spot Theorem  

SciTech Connect

A real number alpha is said to be b-normal if every m-long string of digits appears in the base-b expansion of alpha with limiting frequency b-m. We prove that alpha is b-normal if and only if it possesses no base-b ''hot spot''. In other words, alpha is b-normal if and only if there is no real number y such that smaller and smaller neighborhoods of y are visited by the successive shifts of the base-b expansion of alpha with larger and larger frequencies, relative to the lengths of these neighborhoods

Bailey, David H.; Misiurewicz, Michal

2005-12-31

241

Properties of Hot Spots for Solar Activity  

Microsoft Academic Search

Hot spots for solar flares are areas of enhanced flare activity in a long term, which rotate rigidly at a certain rate. For example, a double-hot-spot system with a synodic period of 26.73 days persisted for three solar cycles (20 through 22) in the same locations in the northern hemisphere. This paper investigates properties of three hot- spot systems. The

T. A. Bai

2007-01-01

242

Advanced Hot-Gas Desulfurization Sorbents  

Microsoft Academic Search

Integrated gasification combined cycle (IGCC) power systems are being advanced worldwide for generating electricity from coal due to their superior environmental performance, economics, and efficiency in comparison to conventional coal-based power plants. Hot gas cleanup offers the potential for higher plant thermal efficiencies and lower cost. A key subsystem of hot-gas cleanup is hot-gas desulfurization using regenerable sorbents. Sorbents based

K. Jothimurugesan; S. K. Gangwal; R. Gupta; B. S. Turk

1997-01-01

243

ADVANCED HOT GAS FILTER DEVELOPMENT  

SciTech Connect

DuPont Lanxide Composites, Inc. undertook a sixty-month program, under DOE Contract DEAC21-94MC31214, in order to develop hot gas candle filters from a patented material technology know as PRD-66. The goal of this program was to extend the development of this material as a filter element and fully assess the capability of this technology to meet the needs of Pressurized Fluidized Bed Combustion (PFBC) and Integrated Gasification Combined Cycle (IGCC) power generation systems at commercial scale. The principal objective of Task 3 was to build on the initial PRD-66 filter development, optimize its structure, and evaluate basic material properties relevant to the hot gas filter application. Initially, this consisted of an evaluation of an advanced filament-wound core structure that had been designed to produce an effective bulk filter underneath the barrier filter formed by the outer membrane. The basic material properties to be evaluated (as established by the DOE/METC materials working group) would include mechanical, thermal, and fracture toughness parameters for both new and used material, for the purpose of building a material database consistent with what is being done for the alternative candle filter systems. Task 3 was later expanded to include analysis of PRD-66 candle filters, which had been exposed to actual PFBC conditions, development of an improved membrane, and installation of equipment necessary for the processing of a modified composition. Task 4 would address essential technical issues involving the scale-up of PRD-66 candle filter manufacturing from prototype production to commercial scale manufacturing. The focus would be on capacity (as it affects the ability to deliver commercial order quantities), process specification (as it affects yields, quality, and costs), and manufacturing systems (e.g. QA/QC, materials handling, parts flow, and cost data acquisition). Any filters fabricated during this task would be used for product qualification tests being conducted by Westinghouse at Foster-Wheeler's Pressurized Circulating Fluidized Bed (PCFBC) test facility in Karhula, Finland. Task 5 was designed to demonstrate the improvements implemented in Task 4 by fabricating fifty 1.5-meter hot gas filters. These filters were to be made available for DOE-sponsored field trials at the Power Systems Development Facility (PSDF), operated by Southern Company Services in Wilsonville, Alabama.

E.S. Connolly; G.D. Forsythe

2000-09-30

244

Slip and Dilation Tendency Anlysis of Neal Hot Springs Geothermal Area  

SciTech Connect

Slip and Dilation Tendency in focus areas Critically stressed fault segments have a relatively high likelihood of acting as fluid flow conduits (Sibson, 1994). As such, the tendency of a fault segment to slip (slip tendency; Ts; Morris et al., 1996) or to dilate (dilation tendency; Td; Ferrill et al., 1999) provides an indication of which faults or fault segments within a geothermal system are critically stressed and therefore likely to transmit geothermal fluids. The slip tendency of a surface is defined by the ratio of shear stress to normal stress on that surface: Ts = ? / ?n (Morris et al., 1996). Dilation tendency is defined by the stress acting normal to a given surface: Td = (?1-?n) / (?1-?3) (Ferrill et al., 1999). Slip and dilation were calculated using 3DStress (Southwest Research Institute). Slip and dilation tendency are both unitless ratios of the resolved stresses applied to the fault plane by ambient stress conditions. Values range from a maximum of 1, a fault plane ideally oriented to slip or dilate under ambient stress conditions to zero, a fault plane with no potential to slip or dilate. Slip and dilation tendency values were calculated for each fault in the focus study areas at, McGinness Hills, Neal Hot Springs, Patua, Salt Wells, San Emidio, and Tuscarora on fault traces. As dip is not well constrained or unknown for many faults mapped in within these we made these calculations using the dip for each fault that would yield the maximum slip tendency or dilation tendency. As such, these results should be viewed as maximum tendency of each fault to slip or dilate. The resulting along-fault and fault-to-fault variation in slip or dilation potential is a proxy for along fault and fault-to-fault variation in fluid flow conduit potential. Stress Magnitudes and directions Stress field variation within each focus area was approximated based on regional published data and the world stress database (Hickman et al., 2000; Hickman et al., 1998 Robertson-Tait et al., 2004; Hickman and Davatzes, 2010; Davatzes and Hickman, 2006; Blake and Davatzes 2011; Blake and Davatzes, 2012; Moeck et al., 2010; Moos and Ronne, 2010 and Reinecker et al., 2005) as well as local stress information if applicable. For faults within these focus systems we applied either a normal faulting stress regime where the vertical stress (sv) is larger than the maximum horizontal stress (shmax) which is larger than the minimum horizontal stress (sv>shmax>shmin) or strike-slip faulting stress regime where the maximum horizontal stress (shmax) is larger than the vertical stress (sv) which is larger than the minimum horizontal stress (shmax >sv>shmin) depending on the general tectonic province of the system. Based on visual inspection of the limited stress magnitude data in the Great Basin we used magnitudes such that shmin/shmax = .527 and shmin/sv= .46, which are consistent with complete and partial stress field determinations from Desert Peak, Coso, the Fallon area and Dixie valley (Hickman et al., 2000; Hickman et al., 1998 Robertson-Tait et al., 2004; Hickman and Davatzes, 2011; Davatzes and Hickman, 2006; Blake and Davatzes 2011; Blake and Davatzes, 2012). Based on inversion of fault kinematic data, Edwards (2013) interpreted that two discrete stress orientations are preserved at Neal Hot Springs. An older episode of east-west directed extension and a younger episode of southwest-northeast directed sinistral, oblique -normal extension. This interpretation is consistent with the evolution of Cenozoic tectonics in the region (Edwards, 2013). As such we applied a southwest-northeast (060) directed normal faulting stress regime, consistent with the younger extensional episode, to the Neal Hot Springs faults. Under these stress conditions northeast striking steeply dipping fault segments have the highest tendency to dilate and northeast striking 60° dipping fault segments have the highest tendency to slip. Under these stress condition...

James E. Faulds

2013-12-31

245

Hot electron production and heating by hot electrons in fast ignitor research  

SciTech Connect

In an experimental study of the physics of fast ignition the characteristics of the hot electron source at laser intensities up to 10(to the 20th power) Wcm{sup -2} and the heating produced at depth by hot electrons have been measured. Efficient generation of hot electrons but less than the anticipated heating have been observed.

Key, M.H.; Estabrook, K.; Hammel, B. [and others

1997-12-01

246

Near-net-shape forming of alumina powder under hot pressing and hot isostatic pressing  

Microsoft Academic Search

Densification and deformation of alumina powder under hot pressing and hot isostatic pressing were investigated. Finite element calculations were performed by implementing constitutive equations for grain growth, power law creep and diffusional creep in the user defined subroutine CREEP of ABAQUS. An alumina compact of valve head shape was produced under hot pressing and its forming process was predicted by

K. T. Kim; Y. S. Kwon; H. G. Kim

1997-01-01

247

Microbiology and geochemistry of Little Hot Creek, a hot spring environment in the Long Valley Caldera  

E-print Network

springs located within the Long Valley Caldera, Little Hot Creek (LHC) 1, 3, and 4. All three springs were that springs associated with the Long Valley Caldera contain microbial populations that show some similaritiesMicrobiology and geochemistry of Little Hot Creek, a hot spring environment in the Long Valley

Ahmad, Sajjad

248

Cool systems for hot cities  

SciTech Connect

On a hot summer day, Los Angeles, CA, like Baltimore, MD, Phoenix, AZ, Washington, D.C., and Tokyo, Japan, is c. 6-8 degrees F hotter than its surrounding areas. Dark buildings and pavement have replaced urban vegetation in these cities, absorbing more solar heat. The urban heat islands that are created result in increased air-conditioning costs, energy use, and pollution. Scientists at the Lawrence Berkeley National Laboratory have been studying the effects of roof system color and type on the energy used to cool a building. The results of this research indicate that roofing professionals should consider the reflectance (albedo) and emittance (release of absorbed heat) of the roof systems they install.

Akbari, Hashem; Bretz, Sarah

1998-09-02

249

Hot Stars in Globular Clusters  

E-print Network

Blue horizontal branch and UV bright stars in several globular clusters are analysed spectroscopically and the results are compared with predictions of stellar evolutionary theory. We find that the distribution of temperatures and surface gravities of the blue HB stars may be explained by the effects of deep mixing. The masses derived for these stars are too low unless one uses the long distance scale for globular clusters. First results on blue HB stars in metal rich clusters are presented. Analyses of hot UV bright stars in globular clusters uncovered a lack of genuine post-asymptotic giant branch stars which may explain the lack of planetary nebulae in globular clusters seen by Jacoby et al. (1997). Abundance analyses of post-AGB stars in two globular clusters suggest that gas and dust may separate during the AGB phase.

S. Moehler

1998-12-08

250

Density reorganization in hot nuclei  

SciTech Connect

The density profile of a hot nuclear system produced in intermediate-energy heavy ion collisions is studied in a microcanonical formulation with a momentum and density dependent finite range interaction. The caloric curve and density evolution with excitation are calculated for a number of systems for the equilibrium mononuclear configuration; they compare favorably with the recent experimental data. The studied density fluctuations are seen to build up rapidly beyond an excitation energy of {approx}8 MeV/u indicating the instability of the system toward nuclear disassembly. Explicit introduction of deformation in the expansion path of the heated nucleus, however, shows that the system might fragment even earlier. We also explore the effects of the nuclear equation of state and of the mass and isospin asymmetry on the nuclear equilibrium configuration and the relevant experimental observables.

Samaddar, S. K.; De, J. N. [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India); Vinas, X.; Centelles, M. [Departament d'Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain)

2007-05-15

251

HotDocs Doc Library  

NSDL National Science Digital Library

To find compelling documentaries from Canadians of all backgrounds and perspectives, one need go no further than the HotDocs Doc Library website. The library is entirely free, and visitors can get started by clicking on one of the four "communities" areas on the homepage. They include "YouthZone", "Educators", "Most Popular", and "Playlists". In the "YouthZone", visitors can view films by and for young filmmakers, such as the social critique found in "Everywhere, Advertisements" and a film on the high price of organic goods titled "Organic Matters". Teachers will appreciate the "Educators" area, which, along with various documentaries, also contains some study exercises titled "Why are Documentaries Worth Watching?" and "What Should We Look for in a Documentary?" Additionally, visitors can just go ahead and use the "Browse" area to look through over 200 films.

252

Hot gas defrost model development and validation  

Microsoft Academic Search

This paper describes the development, validation, and application of a transient model for predicting the heat and mass transfer effects associated with an industrial air-cooling evaporator during a hot gas defrost cycle. The inputs to the model include the space dry bulb temperature, space humidity, coil geometry, frost thickness, frost density, and hot gas inlet temperature. The model predicts the

N. Hoffenbecker; S. A. Klein; D. T. Reindl

2005-01-01

253

Are we putting in hot water?  

E-print Network

Are we putting our fish in hot water? Global warming and the world's fisheries · Hot, hungry, and gasping for air · Shrinking fish and fewer babies? · Global warming puts fish on the run · Warm water to be done? #12;2 3 Dashing through sparkling water, probing muddy depths, or weaving through a maze

Combes, Stacey A.

254

Improved Circuit For Hot-Film Anemometer  

NASA Technical Reports Server (NTRS)

Circuit suitable for automation or computer control of setup and operation. Hot-film or hot-wire anemometer circuit features individual current drives for two arms of wheatstone bridge, plus other features that provide improved calibration and automated or computer-controlled operation.

Gray, David L.

1993-01-01

255

Hot Dry Rock Geothermal Energy Technology  

NSDL National Science Digital Library

This site helps to explain Hot Dry Rock (HDR) Technology, which harnesses geothermal energy to produce electricity. The website contains images and information about how hot dry rock technology is being used all over the world. The site also provides a list of contacts and additional related websites.

2007-07-20

256

Hot spot cooling using embedded thermoelectric coolers  

Microsoft Academic Search

Localized areas of high heat flux on microprocessors produce hot spots that limit their reliability and performance. With increasingly dense circuits and the integration of high power processors with low power memory, non-uniform thermal profiles will become more dramatic and difficult to manage. Chip scale thermal solutions designed to keep hot spots below a critical temperature unnecessarily overcool the rest

G. Jeffrey Snyder; Marco Soto; Randy Alley; David Koester; Bob Conner

2006-01-01

257

Hot-dry-rock feasibility study  

SciTech Connect

The hot-dry-rock project tasks are covered as follows: hot-dry-rock reservoir; generation facilities; water resources; transmission requirements; environmental issues; government and community institutional factors; leasing, ownership and management of facilities; regulations, permits, and laws; and financial considerations. (MHR)

Not Available

1981-08-01

258

FOOD AND DRINK REGULATIONS Serving hot food  

E-print Network

1 FOOD AND DRINK REGULATIONS Serving hot food Home made hot food may not be served at events conditions must be adhered to: · The caterer must have HSE Food Hygiene Certification, which is to be approved by the College Catering Manager two weeks in advance of any event. · The provider of the food

O'Mahony, Donal E.

259

What's hot in Machine Learning? Anima Anandkumar  

E-print Network

;Challenges in Feature Learning In practice Deep learning has provided impressive gains. Parameter trainingWhat's hot in Machine Learning? Anima Anandkumar U.C. Irvine #12;What's hot in ML: Representation Learning Feature Engineering Learn good features/representations for classification tasks, e.g. image

Anandkumar, Animashree

260

Performance of solar energy hot water systems  

Microsoft Academic Search

The results of performance comparisons of four solar hot water\\/building heat installations of the National Solar Data Network are presented. The sites were monitored by various sensors and data were processed remotely at a central location. Statistics are presented for seasonal hot water demand, solar fraction, fuel saved, supply and delivery temperatures, auxiliary fuel required, and costs, in addition to

M. A. Cramer; K. D. Evans; J. M. Rosenbusch; R. A. Weinstein

1981-01-01

261

Is Hot Spot Policing Effective Empirically?  

Microsoft Academic Search

This paper examines the literature used to argue hot spot policing is an effective crime reduction technique. More specifically Sherman, Farrington, Welsh, and MacKenzie (2002) used five experimental or quasi-experimental studies that were given a Maryland Scientific Methods Scale (SMS) of 3 or greater. The authors posited that these five articles provide enough evidence to establish that hot spot policing

Joshua R. Battin

2009-01-01

262

Basics of Solar Heating & Hot Water Systems.  

ERIC Educational Resources Information Center

In presenting the basics of solar heating and hot water systems, this publication is organized from the general to the specific. It begins by presenting functional and operational descriptions of solar heating and domestic hot water systems, outlining the basic concepts and terminology. This is followed by a description of solar energy utilization…

American Inst. of Architects, Washington, DC.

263

The Hot Hand Belief and Framing Effects  

ERIC Educational Resources Information Center

Purpose: Recent evidence of the hot hand in sport--where success breeds success in a positive recency of successful shots, for instance--indicates that this pattern does not actually exist. Yet the belief persists. We used 2 studies to explore the effects of framing on the hot hand belief in sport. We looked at the effect of sport experience and…

MacMahon, Clare; Köppen, Jörn; Raab, Markus

2014-01-01

264

Variational Theory of Hot Dense Matter  

ERIC Educational Resources Information Center

We develop a variational theory of hot nuclear matter in neutron stars and supernovae. It can also be used to study charged, hot nuclear matter which may be produced in heavy-ion collisions. This theory is a generalization of the variational theory of cold nuclear and neutron star matter based on realistic models of nuclear forces and pair…

Mukherjee, Abhishek

2009-01-01

265

Thermocoagulation with Hot Air in Thoracic Surgery  

Microsoft Academic Search

Thermocoagulation with hot air is a new hemostatic procedure. During pulmonary surgery oozing blood and air leaking can be controlled by sweeping a high velocity air stream of about 420°C over a pulmonary surface stripped of visceral pleura. The hot air thermocoagulator can also control oozing of blood from the epicardium.

Jes Sandermann; Jan Aagaard; Preben Løvgreen Nielsen

1995-01-01

266

Enabling Technologies for Ceramic Hot Section Components  

Microsoft Academic Search

Silicon-based ceramics are attractive materials for use in gas turbine engine hot sections due to their high temperature mechanical and physical properties as well as lower density than metals. The advantages of utilizing ceramic hot section components include weight reduction, and improved efficiency as well as enhanced power output and lower emissions as a result of reducing or eliminating cooling.

Venkat Vedula; Tania Bhatia

2009-01-01

267

Solar Energy for Space Heating & Hot Water.  

ERIC Educational Resources Information Center

This pamphlet reviews the direct transfer of solar energy into heat, particularly for the purpose of providing space and hot water heating needs. Owners of buildings and homes are provided with a basic understanding of solar heating and hot water systems: what they are, how they perform, the energy savings possible, and the cost factors involved.…

Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.

268

Toolbox Safety Talk Hot Work Safety Procedures  

E-print Network

WORK Obtain a hot work permit from your supervisor or safety rep. Ensure fire/smoke detection/vapors, eliminate explosive atmosphere (verify with confined space air quality meter). Enclosed equipment cleaned and ventilated. AFTER COMPLETION OF HOT WORK Ensure fire/smoke detection & suppression systems are returned

Pawlowski, Wojtek

269

HotSpot Software Configuration Management Plan  

SciTech Connect

This Software Configuration Management Plan (SCMP) describes the software configuration management procedures used to ensure that the HotSpot dispersion model meets the requirements of its user base, which includes: (1) Users of the PC version of HotSpot for consequence assessment, hazard assessment and safety analysis calculations; and (2) Users of the NARAC Web and iClient software tools, which allow users to run HotSpot for consequence assessment modeling These users and sponsors of the HotSpot software and the organizations they represent constitute the intended audience for this document. This plan is intended to meet Critical Recommendations 1 and 3 from the Software Evaluation of HotSpot and DOE Safety Software Toolbox Recommendation for inclusion of HotSpot in the Department of Energy (DOE) Safety Software Toolbox. HotSpot software is maintained for the Department of Energy Office of Emergency Operations by the National Atmospheric Release Advisory Center (NARAC) at Lawrence Livermore National Laboratory (LLNL). An overview of HotSpot and NARAC are provided.

Walker, H; Homann, S G

2009-03-12

270

HotSpot Software Test Plan  

SciTech Connect

This Software Test Plan (STP) describes the procedures used to verify and validate that the HotSpot Health Physics Codes meet the requirements of its user base, which includes: (1) Users of the PC version of HotSpot conducting consequence assessment, hazard assessment and safety analysis calculations; and (2) Users of the NARAC Web and iClient software tools, which allow users to run HotSpot for consequence assessment modeling. This plan is intended to meet Critical Recommendation 2 from the Software Evaluation of HotSpot and DOE Safety Software Toolbox Recommendation for inclusion of HotSpot in the Department of Energy (DOE) Safety Software Toolbox. These users and sponsors of the HotSpot software and the organizations they represent constitute the intended audience for this document. HotSpot software is maintained for the Department of Energy Office of Emergency Operations by the National Atmospheric Release Advisory Center (NARAC) at Lawrence Livermore National Laboratory (LLNL). An overview of HotSpot and NARAC are provided.

Walker, H; Homann, S G

2009-03-12

271

Turbine Engine Hot Section Technology, 1985  

NASA Technical Reports Server (NTRS)

The Turbine Engine Section Technology (HOST) Project Office of the Lewis Research Center sponsored a workshop to discuss current research pertinent to turbine engine hot section durability problems. Presentations were made concerning hot section environment and the behavior of combustion liners, turbine blades, and turbine vanes.

1985-01-01

272

STATE OF CALIFORNIA DOMESTIC HOT WATER (DHW)  

E-print Network

STATE OF CALIFORNIA DOMESTIC HOT WATER (DHW) CEC- CF-6R-MECH-01 (Revised 08/09) CALIFORNIA ENERGY COMMISSION INSTALLATION CERTIFICATE CF-6R-MECH-01 Domestic Hot Water (DHW) (Page 1 of 3) Site Address: Enforcement Agency: Permit Number: 2008 Residential Compliance Forms August 2009 1. WATER HEATING SYSTEMS

273

Fracture toughness of hot-pressed beryllium  

NASA Technical Reports Server (NTRS)

This paper presents the results of an investigation into the fracture toughness, sustained-load flaw growth, and fatigue-crack propagation resistance of S200E hot-pressed beryllium at room temperature. It also reviews the literature pertaining to the influence of various factors on the fracture toughness of hot-pressed beryllium determined using fatigue-cracked specimens.

Lemon, D. D.; Brown, W. F., Jr.

1985-01-01

274

Structure of Hot Flow Anomaly  

NASA Astrophysics Data System (ADS)

Hot Flow Anomalies (HFAs) were first discovered in 1980s. These are active processes of hot plasma bulks formation that usually occur at planetary bow shocks. Though HFA were studied for long time it is still not clear if they are reforming structures and what defines particular internal structure of HFA. Our study is based on the Interball Tail Probe data. We used 10-sec measurements of complex plasma analyzer SCA-1 and 1-second magnetic field measurements, and ELECTRON spectrometer 2-dimensional measurements with 3,75-sec temporal resolution. Five anomalies that were observed on the basis of well resolved structure for which we obtained displacement velocity along bow shock, flow velocities within HFA, and estimated the size. We checked if main criteria of HFA formation were fulfilled for each case. The following criteria were satisfied: motional electric field direction was directed toward current sheet at least at one side of it, bow shock was quasi-perpendicular at least at one side of HFA, and angle between current sheet normal and solar wind velocity was large. Convection velocities of plasma within HFA were calculated by subtracting average velocity from measured ion convection velocities along spacecraft trajectory through anomaly. These convection velocities viewed in coordinate system of shock normal and calculated IMF current sheet normal clearly show separation of HFA region in 3 parts: leading part, narrow central part, and trailing part. Ion velocity distributions confirm this triple structure of HFA. Thomsen et al. [1986] identified the region within HFA that they called "internal recovery". It looks like central region that we call narrow central part. Vaisberg et al. [1999] discussed separation of HFA into 2 distinct parts that correspond to leading and trailing parts. Judging from plasma convection pattern within HFAs we assumed that "internal recovery" region is the source of energy and momentum around interplanetary current sheet crossing. HFA formation mechanisms presume that HFA is formed when particles are reflected on bow shock, get swept by motional electric field and are injected back into the area. We tried to calculate the balance of energy in solar wind and within HFA to estimate what amount of reflected particles is needed for "internal recovery" area to be the real energy source. These estimations suggest that this energy balance is nearly fulfilled in 4 of 5 analyzed HFAs, and does not hold for one HFA. This energy balance may be in favor of quasi-stationary nature of HFA structure. References Thomsen, M. F., J. T. Gosling, S. A. Fuselier, S. J. Bame, and C. T. Russell (1986), Hot, diamagnetic cavities upstream from the Earth's bow shock, J. Geophys. Res., 91(A3), 2961-2973, doi:10.1029/JA091iA03p02961. Vaisberg, O.L., J.H.Waite, L.Avanov, V.N.Smirnov, D.Dempsey J.L.Burch and A.A.Skalsky, HFA-like signatures observed with Interball-Tail spacecraft, in: Solar Wind Nine, ed. By S.R.Habbal, R.Esser, J.V.Hollweg, and P.A.Isenberg, AIP 1-56396-865-7, 1999, pp. 551-554.

Shestakov, A.; Vaisberg, O. L.

2012-12-01

275

14 CFR 25.961 - Fuel system hot weather operation.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Fuel system hot weather operation. 25.961 Section 25...System § 25.961 Fuel system hot weather operation. (a) The fuel system must perform satisfactorily in hot weather operation. This must be...

2013-01-01

276

14 CFR 25.961 - Fuel system hot weather operation.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 false Fuel system hot weather operation. 25.961 Section 25...System § 25.961 Fuel system hot weather operation. (a) The fuel system must perform satisfactorily in hot weather operation. This must be...

2011-01-01

277

14 CFR 25.961 - Fuel system hot weather operation.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 false Fuel system hot weather operation. 25.961 Section 25...System § 25.961 Fuel system hot weather operation. (a) The fuel system must perform satisfactorily in hot weather operation. This must be...

2012-01-01

278

14 CFR 25.961 - Fuel system hot weather operation.  

...2014-01-01 false Fuel system hot weather operation. 25.961 Section 25...System § 25.961 Fuel system hot weather operation. (a) The fuel system must perform satisfactorily in hot weather operation. This must be...

2014-01-01

279

Filter for cleaning hot gases  

SciTech Connect

In an apparatus for cleaning hot gases a filter housing has an inlet for unfiltered gas and an outlet for filtered gas. A plurality of filtered inserts are placed within the housing in a manner capable of filtering undesirable components from the gas feed stream. Each filter insert is made of a fibrous filter material. Silicic-acid glass fibers have a silicic acid content of at least 90%. Coated upon the fibers and absorbed into their pores is a metal oxide of aluminum, titanium, zirconium, cromium, nickle or cobalt. A honeycombed cage filled with high temperature resistant perlite is located within the housing between the gas inlet and the fiber inserts. The cage has an inlet and outlet external to the housing for replacing the perlite. A combustion chamber mounted in the housing has a discharge nozzle located so that the nozzle is directed at the filter inserts. Combusting materials in the chamber causes an explosive backflow of gases through the filter inserts.

Gresch, H.; Holter, H.; Hubner, K.; Igelbuscher, H.; Weber, E.

1981-10-20

280

Hot Leg Piping Materials Issues  

SciTech Connect

With Naval Reactors (NR) approval of the Naval Reactors Prime Contractor Team (NRPCT) recommendation to develop a gas cooled reactor directly coupled to a Brayton power conversion system as the space nuclear power plant (SNPP) for Project Prometheus (References a and b) the reactor outlet piping was recognized to require a design that utilizes internal insulation (Reference c). The initial pipe design suggested ceramic fiber blanket as the insulation material based on requirements associated with service temperature capability within the expected range, very low thermal conductivity, and low density. Nevertheless, it was not considered to be well suited for internal insulation use because its very high surface area and proclivity for holding adsorbed gases, especially water, would make outgassing a source of contaminant gases in the He-Xe working fluid. Additionally, ceramic fiber blanket insulating materials become very friable after relatively short service periods at working temperatures and small pieces of fiber could be dislodged and contaminate the system. Consequently, alternative insulation materials were sought that would have comparable thermal properties and density but superior structural integrity and greatly reduced outgassing. This letter provides technical information regarding insulation and materials issues for the Hot Leg Piping preconceptual design developed for the Project Prometheus space nuclear power plant (SNPP).

V. Munne

2006-07-19

281

Iron Aluminide Hot Gas Filters  

SciTech Connect

Currently, high temperature filter systems are in the demonstration phase with the first commercial scale hot filter systems being installed on integrated gasification combined cycle (IGCC) and pressurized fluid bed combustion cycle (PBFC) systems (70 MW). They are dependent on the development of durable and economic high temperature filter systems. These filters are mostly ceramic tubes or candles. Ceramic filter durability has not been high. Failure is usually attributed to mechanical or thermal shock: they can also undergo significant changes due to service conditions. The overall objective of this project is to commercialize weldable, crack resistant filters which will provide several years service in advanced power processes. The specific objectives of this project are to develop corrosion resistant alloys and manufacturing processes to make Iron Aluminide filter media, and to use a ``short term`` exposure apparatus supported by other tests to identify the most promising candidate (alloy plus sintering cycle). The objectives of the next phases are to demonstrate long term corrosion stability for the best candidate followed by the production of fifty filters (optional).

Hurley, J.; Brosious, S.; Johnson, M. [Pall Process Equipment Development Div., Pall Corp., Cortland, NY (United States)

1996-12-31

282

NASA helps reduce city hot spots  

NASA Astrophysics Data System (ADS)

When researchers from NASA's Marshall Space Flight Center in Huntsville, Ala., recently flew a thermal camera, mounted on a NASA aircraft, over Baton Rouge, La., Sacramento, Calif., and Salt Lake City, Utah, they took each city's temperature and produced an image that pinpoints the cities' "hot spots."Now, the researchers are using the images to study what types of surfaces in cities contribute to bubble-like accumulations of hot air, called urban heat islands. The bubbles of hot air develop over cities as naturally vegetated surfaces are replaced with asphalt, concrete, rooftops, and other man-made materials.

Showstack, Randy

283

Hot Jupiter Variability in Eclipse Depth  

E-print Network

Physical conditions in the atmospheres of tidally-locked, slowly-rotating hot Jupiters correspond to dynamical circulation regimes with Rhines scales and Rossby deformation radii comparable to the planetary radii. Consequently, the large spatial scales of moving atmospheric structures could generate significant photospheric variability. Here, we estimate the level of thermal infrared variability expected in successive secondary eclipse depths, according to hot Jupiter turbulent ``shallow-layer'' models. The variability, at the few percent level or more in models with strong enough winds, is within the reach of Spitzer measurements. Eclipse depth variability is thus a valuable tool to constrain the circulation regime and global wind speeds in hot Jupiter atmospheres.

Emily Rauscher; Kristen Menou; James Y-K. Cho; Sara Seager; Brad Hansen

2006-12-14

284

Factors influencing the locations of hot spots determined by the hot-spotting technique  

NASA Astrophysics Data System (ADS)

Seafloor beneath hot-spot-produced seamounts have crustal flow lines that intersect at the hot spot locations, provided there is more than one stage rotation and that hot spots are stationary. Convolving seamount shapes with their associated flow lines yields an image of cumulative volcano amplitude (CVA). We call the technique of correlating local CVA maxima with hot spot locations “hot-spotting”. This technique is geometrical and requires no age information for seamounts or seafloor. We analyze synthetic and actual seamount data and demonstrate that factors such as across-trail scatter in seamount locations, inaccurate stage poles, and migration of hot spots all exert strong influences on the locations and appearances of CVA maxima. The interpretation of raw CVA images is therefore not straightforward.

Wessel, Paul; Kroenke, Loren W.

285

"Hot Tub Rash" and "Swimmer's Ear" (Pseudomonas)  

MedlinePLUS

... parks, interactive fountains, water play areas, hot tubs, lakes, rivers, springs, ponds, streams, or the ocean stays ... in locations that have been closed because of pollution. Pseudomonas can multiply quickly when water disinfectant levels ...

286

Laser anemometers of hot-section applications  

NASA Technical Reports Server (NTRS)

Laser anemometers are being developed for use in the turbine facilities at Lewis that are involved in the Turbine Engine Hot Section Technology Program. The status of the program is given along with some results accomplished since 1983.

Seasholtz, R. G.; Oberle, L. G.; Weikle, D. H.

1984-01-01

287

Frequency Responses Of Hot-Wire Anemometers  

NASA Technical Reports Server (NTRS)

Report describes theoretical study of frequency response of constant-temperature hot-wire anemometer, with view toward increasing frequency response while maintaining stable operation in supersonic flow. Effects of various circuit parameters discussed.

Watmuff, Jonathan H.

1992-01-01

288

A constant temperature hot-wire anemometer  

Microsoft Academic Search

A compact, inexpensive, constant temperature hot-wire anemometer circuit using solid state operational amplifiers is described. A theoretical expression for frequency response and an experimental check are given. Theoretical and experimental response data for an existing unit are shown.

J C Wyngaard; J L Lumley

1967-01-01

289

Wall Drying in Hot and Humid Climates  

E-print Network

and how that moisture can be managed. This paper explores the mechanisms of wall drying, focusing on how wood frame walls dry in hot, humid climates. This paper describes laboratory drying studies of conventional sheathing / weather resistive barrier...

Boone, K.; Weston, T.; Pascual, X.

2004-01-01

290

Arnold Schwarzenegger WATER HEATERS AND HOT WATER  

E-print Network

Arnold Schwarzenegger Governor WATER HEATERS AND HOT WATER DISTRIBUTION SYSTEMS;#12;Appendices Appendix A. Multifamily Water Heating Construction Practices, Pricing and Availability Survey Report Appendix B. Multifamily Water Heating Controls Performance Field Report Appendix C. Pipe

291

Hot Isostatic Pressing of Ceramic Powder Compacts.  

National Technical Information Service (NTIS)

The effect of temperature, pressure and time on the rate of densification of submicron alumina powder during hot isostatic pressing has been determined using a dilatometer to continuously monitor volumetric changes. A Fortran computer program is used to m...

J. K. McCoy, R. R. Wills

1984-01-01

292

Phage Community Dynamics in Hot Springs  

PubMed Central

In extreme thermal environments such as hot springs, phages are the only known microbial predators. Here we present the first study of prokaryotic and phage community dynamics in these environments. Phages were abundant in hot springs, reaching concentrations of a million viruses per milliliter. Hot spring phage particles were resistant to shifts to lower temperatures, possibly facilitating DNA transfer out of these extreme environments. The phages were actively produced, with a population turnover time of 1 to 2 days. Phage-mediated microbial mortality was significant, making phage lysis an important component of hot spring microbial food webs. Together, these results show that phages exert an important influence on microbial community structure and energy flow in extreme thermal environments. PMID:15006788

Breitbart, Mya; Wegley, Linda; Leeds, Steven; Schoenfeld, Tom; Rohwer, Forest

2004-01-01

293

Design data brochure: Solar hot air heater  

NASA Technical Reports Server (NTRS)

The design, installation, performance, and application of a solar hot air heater for residential, commercial and industrial use is reported. The system has been installed at the Concho Indian School in El Reno, Oklahoma.

1978-01-01

294

Toward Eclipse Mapping of Hot Jupiters  

E-print Network

Recent Spitzer infrared measurements of hot Jupiter eclipses suggest that eclipse mapping techniques could be used to spatially resolve the day-side photospheric emission of these planets using partial occultations. As a first step in this direction, we simulate ingress/egress lightcurves for the three brightest known eclipsing hot Jupiters and evaluate the degree to which parameterized photospheric emission models can be distinguished from each other with repeated, noisy eclipse measurements. We find that the photometric accuracy of Spitzer is insufficient to use this tool effectively. On the other hand, the level of photospheric details that could be probed with a few JWST eclipse measurements could greatly inform hot Jupiter atmospheric modeling efforts. A JWST program focused on non-parametric eclipse map inversions for hot Jupiters should be actively considered.

Emily Rauscher; Kristen Menou; Sara Seager; Drake Deming; James Y-K. Cho; Brad Hansen

2006-12-14

295

Sensitivity analysis of hot channel calculation methods  

Microsoft Academic Search

In safety analysis, the fulfillment of acceptance criteria is usually evaluated by separate hot channel or\\/and hot assembly thermal hydraulic\\/fuel behavior calculations. The whole range of the relevant input parameters (e.g. power distributions, burnup, heat conduction data, inlet temperature, etc.) must be taken into account. Concerning these parameters, the most frequent conservative approach is to select the limiting values, partly

I. Panka; M. Telbisz

2007-01-01

296

Teaching Earth Science Using Hot Air Balloons  

NSDL National Science Digital Library

Constructing model hot air balloons is an activity that captures the imaginations of students, enabling teachers to present required content to minds that are open to receive it. Additionally, there are few activities that lend themselves to integrating so much content across subject areas. In this article, the authors describe how they have successfully used hot air balloons to teach metric measurement, proportions, trigonometric functions, density, convection, data collection and analysis, principles of engineering, and many other concepts and skills.

Kuhl, James; Shaffer, Karen

2008-01-01

297

Advanced hot-gas filter development  

Microsoft Academic Search

Coal is the most abundant fossil-fuel resource in the United States. `Clean coal` technologies, such as pressurized fluidized-bed combustion (PFBC) and integrated gasification combined-cycle (IGCC), require a hot gas filter to remove the corrosive and erosive coal ash entrained in the combustion gas stream. These hot gas filters, or candle filters, must be cost-effective while able to withstand the effects

E. P. Stankiewicz; A. J. Sherman; A. A. Zinn

1997-01-01

298

THz hot-electron photon counter  

Microsoft Academic Search

We discuss an implementation of a hot-electron transition-edge sensor (TES) capable of counting THz photons. The main need for such a THz calorimeter is spectroscopy on future space telescopes with a background limited NEP?10-20 W\\/Hz12\\/. The micromachined bolometers will unlikely reach such sensitivity at temperatures above 10 mK. The hot-electron TES with sufficient sensitivity will still have a time constant

Boris S. Karasik; Andrei V. Sergeev

2005-01-01

299

Sampling Particles In Hot Gas Plumes  

NASA Technical Reports Server (NTRS)

Sampling darts and launching apparatus built to collect particles in vertical plume of hot gas. In original application, hot gas plume is rocket-engine exhaust during test firing. Dart passes made at various heights, depending on launch angle and launch-gas pressure. Adaptable to variety of terrestrial uses like research on particulate emissions of volcanoes or determining origin of building fire while still burning.

Taylor, James F.; Sambamurthi, Jay

1994-01-01

300

World launch! Hot-Steam Aerostat  

E-print Network

Info HeiDAS UH World launch! Hot-Steam Aerostat #12;"If you intend to view the land, if you plan Verne: "Fife weeks on a balloon". HeiDAS stands for HeiÃ?DampfAeroStat (Hot-Steam AeroStat) and it refers to the first operable balloon ever that became buoyant by means of superheated steam. The performance of Hei

Berlin,Technische Universität

301

Turbine and hot gas cleanup at Wilsonville  

SciTech Connect

Southern Company Services, Inc. (SCS) has entered into an agreement with the Department of Energy, Morgantown Energy Technology Center (DOE/METC) to design, construct and operate the Hot Gas Cleanup Test Facility for Gasification and Pressurized Combustion. The purpose is to identify and evaluate potential hot particulate cleanup systems on a scale large enough so that these systems can be related to potential commercial system. This entails first developing the criteria for engineering-scale testing of hot particulate control devices which will lead to the design, construction and operation of a flexible test facility capable of operating under gasification and PFBC conditions. This will allow the testing of particulate control devices (PCDs) under realistic conditions in terms of gas composition, temperature, pressure, particulate loading and operating duration. The conceptual design of the Hot Gas Cleanup Test Facility Project was expanded to include additional modules to better address the scope of the Cooperative Agreement with the DOE/METC. The expanded test facility, referred to as the Power Systems Development Facility (PSDF), will provide a flexible test location in which the development of advanced power system components, the evaluation of advanced turbine and fuel cell configurations, and the integration and control issues of these systems. The facility is intended to provide direct support for upcoming DOE demonstrations of power generation technologies utilizing hot stream cleanup and will provide a resource for rigorous testing and performance assessment of hot stream cleanup devices now being developed with the support of DOE/METC.

Sears, R.E.; Griswold, G.H. [Southern Co. Services, Inc., Birmingham, AL (United States); Fankhanel, M.O. [Kellogg (M.W.) Co. (United States); Kastner, C.E. [Foster Wheeler Corp. (United States); Pontius, D.H. [SRI International, Menlo Park, CA (United States)

1993-01-01

302

Hot Jupiter Radii: A Turbulent History  

NASA Astrophysics Data System (ADS)

Many hot Jupiters, i.e. giant exoplanets with short orbital periods, are bloated, with radii that greatly exceed those of colder gas giants. In models that neglect atmospheric motion, the enhanced irradiation of hot Jupiters is insufficient to explain their large radii. However uneven surface irradiation drives atmospheric circulation. These atmospheric motions deposit heat at deeper layers than irradiation alone, and can explain their large radii. The specific dissipation mechanism for atmospheric circulation can involve a turbulent cascade and/or the driving of electric currents that undergo Ohmic dissipation. The “Mechanical Greenhouse” model (Youdin & Mitchell, 2010) showed that turbulence in hot Jupiter atmospheres does mechanical work against the stable stratification of upper radiative zones, thereby driving a heat flux deeper into the interior. This poster will describe the first efforts to include this turbulent heat flux in planetary structure models. The goal is to understand the effects of turbulent mixing on hot Jupiter radius evolution. To perform these calculations we modify the publicly available stellar structure code MESA. We show how the effects of turbulence can be included in MESA — and understood physically — as an effective dissipation profile. We compare the radius evolution of hot Jupiters for different dissipation prescriptions, including our turbulent mixing model and others from the literature. We find that turbulent mixing is an energetically efficient way to explain the bloated radii of hot Jupiters.

Youdin, Andrew N.; Komacek, Thaddeus D.

2014-11-01

303

The hot aluminum dross recycling (HDR) system  

SciTech Connect

The usual methods of processing aluminum dross involve first cooling the dross to room temperature by means such as rotary drum coolers, stationary inert gas coolers or floor spreading, with varying effectiveness. The remaining metal is then recovered by reheating the raw dross (or a milled concentrate) with salt flux in a rotary furnace or, less frequently, in a side-well reverbatory furnace. It has long been apparent that there would be energy savings and probably recovery improvements if hot dross could be processed directly in a rotary furnace. The first requirement is that the processing plant be close to the furnaces generating the dross, which is often not the case. Even when this is the case, most if not all attempts to process hot dross directly have failed. The principal cause has been that the supply of dross is irregular. The solution, perhaps obvious in hindsight, is to devise a means of decoupling the generation of hot dross by the cast house and its consumption by the recovery furnace. Reliable and economical equipment had to be developed to store the hot dross for processing at a convenient time. The Hot Dross Holder is the core development which led to the success of the Hot Dross Recycling (HDR) system at MICA Metals Inc.

Spoel, H. [Spalco Metals Inc., Toronto, Ontario (Canada); Zebedee, W.A. [MICA Metals Inc., Bloomfield Hills, MI (United States)

1996-10-01

304

Canopy hot-spot as crop identifier  

SciTech Connect

Illuminating any reflective rough or structured surface by a directional light source results in an angular reflectance distribution that shows a narrow peak in the direction of retro-reflection. This is called the Heiligenschein or hot-spot of vegetation canopies and is caused by mutual shading of leaves. The angular intensity distribution of the hot-spot, its brightness and slope, are therefore indicators of the plant's geometry. We propose the use of hot-spot characteristics as crop identifiers in satellite remote sensing because the canopy hot-spot carries information about plant stand architecture that is more distinctive for different plant species than, for instance, their spectral reflectance characteristics. A simple three-dimensional Monte Carlo/ray tracing model and an analytic two-dimensional model are developed to estimate the angular distribution of the hot-spot as a function of the size of the plant leaves. The results show that the brightness-distribution and slope of the hot-spot change distinctively for different leaf sizes indicating a much more peaked maximum for the smaller leaves.

Gerstl, S.A.W.; Simmer, C.; Powers, B.J.

1986-05-01

305

Radiative efficiency of hot accretion flows  

NASA Astrophysics Data System (ADS)

Over the past few years, our understanding of hot accretion flows has been improved significantly by two findings: (i) only a small fraction of the accretion flow available at the outer boundary can finally fall on to the black hole, while most of it is lost in the outflow; (ii) electrons can directly receive a large fraction of the viscously dissipated energy in the accretion flow (i.e. ? ˜ 0.1-0.5). The radiative efficiency of the hot accretion flow when these two findings are taken into account has not yet been systematically studied, and this is the subject of our paper. We consider two regimes of the hot accretion model: advection-dominated accretion flows that lie in the regime of the low accretion rate, ?10?2L Edd /c2, and the luminous hot accretion flows (LHAFs) that lie above this accretion rate. For the LHAFs, we assume that the accretion flow has a two-phase structure above a certain accretion rate, and we adopt a simplification in our calculation of the dynamics. Our results indicate that the radiative efficiency of hot accretion flow increases with the accretion rate and that it is greatly enhanced by the direct viscous heating to electrons, compared to the previous case of ? ? 1. When the accretion rate is high, the radiative efficiency of the hot accretion flow is comparable to that of a standard thin disc. We present fitting formulae of radiative efficiency as a function of accretion rate for various values of ?.

Xie, Fu-Guo; Yuan, Feng

2012-12-01

306

Experimental study of deep drawability of hot rolled IF steel  

Microsoft Academic Search

The effects of the hot rolling conditions on the deep drawability of hot rolled interstitial-free (IF) steel were investigated in this paper. Experiments showed that the rolling lubrication affected the deep drawability of the hot rolled IF steel greatly. Without rolling lubrication, the hot rolled IF steel could not obtain deep drawability. Pass reduction also had a significant effect on

H Zhao; S. C Rama; G. C Barber; Z Wang; X Wang

2002-01-01

307

The Effectiveness of Hot-deck Procedures in Small Samples.  

ERIC Educational Resources Information Center

A simulation study was conducted to identify the best hot-deck variation to impute missing values. The three variations included in the study were the hot-deck random, the hot-deck sequential, and the hot-deck distance. The properties of these methods were investigated under three levels of the proportion of incomplete records and four levels…

Kaiser, Javaid

308

Relationship between hot springs and geothermal fields in Japan  

Microsoft Academic Search

Hot springs usually are situated in the volcanic belt of a convergent zone and are utilized as indicators of geothermal potential in an area. Characteristics of hot springs in Japan have been examined in order to understand the relationship between hot springs and geothermal fields. The characteristics examined include locations of hot springs, their temperature, density of distribution, flow rate,

Hemendra R. Acharya

1989-01-01

309

Hot Water DJ: Saving Energy by Pre-mixing Hot Water Md Anindya Prodhan  

E-print Network

Hot Water DJ: Saving Energy by Pre-mixing Hot Water Md Anindya Prodhan Department of Computer University of Virginia whitehouse@virginia.edu Abstract After space heating and cooling, water heating consumption. Current water heating systems waste up to 20% of their energy due to poor insulation in pipes

Whitehouse, Kamin

310

HOT CELL BUILDING, TRA632. HOT CELL AWAITS INSTALLATION OF SHIELDED ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HOT CELL BUILDING, TRA-632. HOT CELL AWAITS INSTALLATION OF SHIELDED WINDOWS. OVERHEAD MASTER/SLAVE MANIPULATORS (LEFT, ABOVE WORKING WINDOWS) WILL MOVE ACROSS GUIDE RAILS IN SLOT ABOVE THE WINDOWS. CAMERA FACING SOUTHEAST. INL NEGATIVE NO. 8996. Unknown Photographer, 10/28/1953 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

311

Kelly Hot Spring Geothermal Project: Kelly Hot Spring Agricultural Center preliminary design. Final technical report  

Microsoft Academic Search

A Phase 1 Preliminary Design, Construction Planning and Economic Analysis has been conducted for the Kelly Hot Spring Agricultural Center in Modoc County, California. The core activity is a 1360 breeding sow, swine raising complex that utilizes direct heat energy from the Kelly Hot Spring geothermal resource. The swine is to be a totally confined operation for producing premium pork

Longyear

1980-01-01

312

Disaggregating Hot Water Use and Predicting Hot Water Waste in Five Test Homes.  

National Technical Information Service (NTIS)

While it is important to make the equipment (or 'plant') in a residential hot water system more efficient, the hot water distribution system also affects overall system performance and energy use. Energy wasted in heating water that is not used is estimat...

H. Henderson, J. Wade, M. Gestwick

2014-01-01

313

Metamaterial perfect absorber based hot electron photodetection.  

PubMed

While the nonradiative decay of surface plasmons was once thought to be only a parasitic process that limits the performance of plasmonic devices, it has recently been shown that it can be harnessed in the form of hot electrons for use in photocatalysis, photovoltaics, and photodetectors. Unfortunately, the quantum efficiency of hot electron devices remains low due to poor electron injection and in some cases low optical absorption. Here, we demonstrate how metamaterial perfect absorbers can be used to achieve near-unity optical absorption using ultrathin plasmonic nanostructures with thicknesses of 15 nm, smaller than the hot electron diffusion length. By integrating the metamaterial with a silicon substrate, we experimentally demonstrate a broadband and omnidirectional hot electron photodetector with a photoresponsivity that is among the highest yet reported. We also show how the spectral bandwidth and polarization-sensitivity can be manipulated through engineering the geometry of the metamaterial unit cell. These perfect absorber photodetectors could open a pathway for enhancing hot electron based photovoltaic, sensing, and photocatalysis systems. PMID:24837991

Li, Wei; Valentine, Jason

2014-06-11

314

Kepler constraints on planets near hot Jupiters.  

PubMed

We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3 d) identified in the Kepler data through its sixth quarter of science operations. Special emphasis is given to companions between the 21 interior and exterior mean-motion resonances. A photometric transit search excludes companions with sizes ranging from roughly two-thirds to five times the size of the Earth, depending upon the noise properties of the target star. A search for dynamically induced deviations from a constant period (transit timing variations) also shows no significant signals. In contrast, comparison studies of warm Jupiters (with slightly larger orbits) and hot Neptune-size candidates do exhibit signatures of additional companions with these same tests. These differences between hot Jupiters and other planetary systems denote a distinctly different formation or dynamical history. PMID:22566651

Steffen, Jason H; Ragozzine, Darin; Fabrycky, Daniel C; Carter, Joshua A; Ford, Eric B; Holman, Matthew J; Rowe, Jason F; Welsh, William F; Borucki, William J; Boss, Alan P; Ciardi, David R; Quinn, Samuel N

2012-05-22

315

Kepler constraints on planets near hot Jupiters  

PubMed Central

We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3 d) identified in the Kepler data through its sixth quarter of science operations. Special emphasis is given to companions between the 2?1 interior and exterior mean-motion resonances. A photometric transit search excludes companions with sizes ranging from roughly two-thirds to five times the size of the Earth, depending upon the noise properties of the target star. A search for dynamically induced deviations from a constant period (transit timing variations) also shows no significant signals. In contrast, comparison studies of warm Jupiters (with slightly larger orbits) and hot Neptune-size candidates do exhibit signatures of additional companions with these same tests. These differences between hot Jupiters and other planetary systems denote a distinctly different formation or dynamical history. PMID:22566651

Steffen, Jason H.; Ragozzine, Darin; Fabrycky, Daniel C.; Carter, Joshua A.; Ford, Eric B.; Holman, Matthew J.; Rowe, Jason F.; Welsh, William F.; Borucki, William J.; Boss, Alan P.; Ciardi, David R.; Quinn, Samuel N.

2012-01-01

316

Multi-cylinder hot gas engine  

DOEpatents

A multi-cylinder hot gas engine having an equal angle, V-shaped engine block in which two banks of parallel, equal length, equally sized cylinders are formed together with annular regenerator/cooler units surrounding each cylinder, and wherein the pistons are connected to a single crankshaft. The hot gas engine further includes an annular heater head disposed around a central circular combustor volume having a new balanced-flow hot-working-fluid manifold assembly that provides optimum balanced flow of the working fluid through the heater head working fluid passageways which are connected between each of the cylinders and their respective associated annular regenerator units. This balanced flow provides even heater head temperatures and, therefore, maximum average working fluid temperature for best operating efficiency with the use of a single crankshaft V-shaped engine block.

Corey, John A. (North Troy, NY)

1985-01-01

317

MAGNETIC DRAG ON HOT JUPITER ATMOSPHERIC WINDS  

SciTech Connect

Hot Jupiters, with atmospheric temperatures T {approx}> 1000 K, have residual thermal ionization levels sufficient for the interaction of ions with the planetary magnetic field to result in a sizable magnetic drag on the (neutral) atmospheric winds. We evaluate the magnitude of magnetic drag in a representative three-dimensional atmospheric model of the hot Jupiter HD 209458b and find that it is a plausible mechanism to limit wind speeds in this class of atmospheres. Magnetic drag has a strong geometrical dependence, both meridionally and from the dayside to the nightside (in the upper atmosphere), which could have interesting consequences for the atmospheric flow pattern. By extension, close-in eccentric planets with transiently heated atmospheres will experience time-variable levels of magnetic drag. A robust treatment of magnetic drag in circulation models for hot atmospheres may require iterated solutions to the magnetic induction and Saha equations as the hydrodynamic flow is evolved.

Perna, Rosalba [JILA and Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States); Menou, Kristen; Rauscher, Emily [Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States)

2010-08-20

318

Radioactive hot cell access hole decontamination machine  

DOEpatents

Radioactive hot cell access hole decontamination machine. A mobile housing has an opening large enough to encircle the access hole and has a shielding door, with a door opening and closing mechanism, for uncovering and covering the opening. The housing contains a shaft which has an apparatus for rotating the shaft and a device for independently translating the shaft from the housing through the opening and access hole into the hot cell chamber. A properly sized cylindrical pig containing wire brushes and cloth or other disks, with an arrangement for releasably attaching it to the end of the shaft, circumferentially cleans the access hole wall of radioactive contamination and thereafter detaches from the shaft to fall into the hot cell chamber.

Simpson, William E. (Richland, WA)

1982-01-01

319

Seeded hot dark matter models with inflation  

NASA Technical Reports Server (NTRS)

We examine massive neutrino (hot dark matter) models for large-scale structure in which the density perturbations are produced by randomly distributed relic seeds and by inflation. Power spectra, streaming velocities, and the Sachs-Wolfe quadrupole fluctuation are derived for this model. We find that the pure seeded hot dark matter model without inflation produces Sachs-Wolfe fluctuations far smaller than those seen by COBE. With the addition of inflationary perturbations, fluctuations consistent with COBE can be produced. The COBE results set the normalization of the inflationary component, which determines the large-scale (about 50/h Mpc) streaming velocities. The normalization of the seed power spectrum is a free parameter, which can be adjusted to obtain the desired fluctuations on small scales. The power spectra produced are very similar to those seen in mixed hot and cold dark matter models.

Gratsias, John; Scherrer, Robert J.; Steigman, Gary; Villumsen, Jens V.

1993-01-01

320

Kepler constraints on planets near hot Jupiters  

SciTech Connect

We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3 d) identified in the Kepler data through its sixth quarter of science operations. Special emphasis is given to companions between the 2:1 interior and exterior mean-motion resonances. A photometric transit search excludes companions with sizes ranging from roughly two-thirds to five times the size of the Earth, depending upon the noise properties of the target star. A search for dynamically induced deviations from a constant period (transit timing variations) also shows no significant signals. In contrast, comparison studies of warm Jupiters (with slightly larger orbits) and hot Neptune-size candidates do exhibit signatures of additional companions with these same tests. These differences between hot Jupiters and other planetary systems denote a distinctly different formation or dynamical history.

Steffen, Jason H.; /Fermilab; Ragozzine, Darin; /Harvard-Smithsonian Ctr. Astrophys.; Fabrycky, Daniel C.; /UC, Santa Cruz, Astron. Astrophys.; Carter, Joshua A.; /Harvard-Smithsonian Ctr. Astrophys.; Ford, Eric B.; /Florida U.; Holman, Matthew J.; /Harvard-Smithsonian Ctr. Astrophys.; Rowe, Jason F.; /NASA, Ames; Welsh, William F.; /San Diego State U., Astron. Dept.; Borucki, William J.; /NASA, Ames; Boss, Alan P.; /Carnegie Inst., Wash., D.C., DTM; Ciardi, David R.; /Caltech /Harvard-Smithsonian Ctr. Astrophys.

2012-05-01

321

Influence of majorite on hot plumes  

NASA Astrophysics Data System (ADS)

influence of MgSiO3 majorite on mantle convection has been investigated via 2-D numerical simulations that incorporate the stability field of majorite. According to a recent first principles study, wadsleyite decomposes into an assemblage of majorite plus periclase with a large negative Clapeyron slope. Since the stability field of majorite is limited to be greater than ~2200 K in a depth range of 500-660 km for Mg2SiO4, very hot upwelling plumes are expected to be strongly influenced by the phase transitions related to majorite. These hot upwellings are occasionally observed in simulations, even though the average temperature of hot plumes is far less than the stability field of majorite. The dynamics of these upwellings are controlled by the release and the absorption of latent heat induced by majorite's phase transitions as well as by the interruption of currents due to the large negative Clapeyron slope related to majorite.

Ichikawa, Hiroki; Kameyama, Masanori; Senshu, Hiroki; Kawai, Kenji; Maruyama, Shigenori

2014-11-01

322

Toward Chemical Constraints on Hot Jupiter Migration  

NASA Astrophysics Data System (ADS)

The origin of hot Jupiters—gas giant exoplanets orbiting very close to their host stars—is a long-standing puzzle. Planet formation theories suggest that such planets are unlikely to have formed in situ but instead may have formed at large orbital separations beyond the snow line and migrated inward to their present orbits. Two competing hypotheses suggest that the planets migrated either through interaction with the protoplanetary disk during their formation, or by disk-free mechanisms such as gravitational interactions with a third body. Observations of eccentricities and spin-orbit misalignments of hot Jupiter systems have been unable to differentiate between the two hypotheses. In the present work, we suggest that chemical depletions in hot Jupiter atmospheres might be able to constrain their migration mechanisms. We find that sub-solar carbon and oxygen abundances in Jovian-mass hot Jupiters around Sun-like stars are hard to explain by disk migration. Instead, such abundances are more readily explained by giant planets forming at large orbital separations, either by core accretion or gravitational instability, and migrating to close-in orbits via disk-free mechanisms involving dynamical encounters. Such planets also contain solar or super-solar C/O ratios. On the contrary, hot Jupiters with super-solar O and C abundances can be explained by a variety of formation-migration pathways which, however, lead to solar or sub-solar C/O ratios. Current estimates of low oxygen abundances in hot Jupiter atmospheres may be indicative of disk-free migration mechanisms. We discuss open questions in this area which future studies will need to investigate.

Madhusudhan, Nikku; Amin, Mustafa A.; Kennedy, Grant M.

2014-10-01

323

Hot dry rock venture risks investigation:  

SciTech Connect

This study assesses a promising resource in central Utah as the potential site of a future commerical hot dry rock (HDR) facility for generating electricity. The results indicate that, if the HDR reservoir productivity equals expectations based on preliminary results from research projects to date, a 50 MWe HDR power facility at Roosevelt Hot Springs could generate power at cost competitive with coal-fired plants. However, it is imperative that the assumed productivity be demonstrated before funds are committed for a commercial facility. 72 refs., 39 figs., 38 tabs.

Not Available

1988-01-01

324

Magnetic Effects on Hot Exoplanet Atmospheres  

NASA Astrophysics Data System (ADS)

Through the process of thermal ionization, intense stellar irradiation renders hot exoplanetary atmospheres electrically conductive. Simultaneously, lateral variability in the irradiation drives the global circulation with peak wind speeds of order ~ km/s. The interactions between the atmospheric flows and the background planetary magnetic field give rise to Lorentz forces that can act to perturb the flow away from its purely hydrodynamical counterpart. In this talk, I will discuss the consequences of magnetohydrodynamic effects on hot planetary atmospheres. Specifically, I will show the results of analytical and numerical calculations that exhibit qualitative deviations from conventional global circulation solutions and discuss potential implications for observational characterization of close-in giant planets.

Batygin, Konstantin; Stanley, Sabine; Stevenson, David J.

2014-11-01

325

Seismic evaluation of a hot cell structure  

SciTech Connect

The evaluation of the structural capacity of and the seismic demand on an existing hot cell structure in a nuclear facility is described. An ANSYS finite-element model of the cell was constructed, treating the walls as plates and the floor and ceiling as a system of discrete beams. A modal analysis showed that the fundamental frequencies of the cell walls lie far above the earthquake frequency range. An equivalent static analysis of the structure was performed. Based on the analysis it was demonstrated that the hot cell structure, would readily withstand the evaluation basis earthquake.

Srinivasan, M.G.; Kot, C.A.

1995-07-01

326

What's Hot in Yellowstone National Park  

NSDL National Science Digital Library

In this activity, learners discover new perspectives on geothermal features, such as geysers, mudpots, hot springs, and hot spring terraces by exploring infrared images. Learners will gain an understanding of infrared light and infrared imaging, as well as, deepen their content knowledge on geothermal features. This lesson features background information for the teacher, background information for students, a mini-exploration of Infrared Image Technology, image sets, assessment information, student worksheets, extension and transfer activities, and additional resources. This is lesson 2 on the Infrared Yellowstone website.

327

Hot water, fresh beer, and salt  

NASA Astrophysics Data System (ADS)

In the ``hot chocolate effect'' the best musical scales (those with the finest tone quality, largest range, and best tempo) are obtained by adding salt to a glass of hot water supersaturated with air. Good scales can also be obtained by adding salt to a glass of freshly opened beer (supersaturated with CO2) provided you first (a) get rid of much of the excess CO2 so as to produce smaller, hence slower, rising bubbles, and (b) get rid of the head of foam, which damps the standing wave and ruins the tone quality. Finally the old question, ``Do ionizing particles produce bubbles in fresh beer?'' is answered experimentally.

Crawford, Frank S.

1990-11-01

328

Thermal tides on a hot Jupiter  

NASA Astrophysics Data System (ADS)

Following the linear analysis laid out by Gu & Ogilvie 2009 (hereafter GO09), we investigate the dynamical response of a non-synchronized hot Jupiter to stellar irradiation. Besides the internal and Rossby waves considered by GO09, we study the Kelvin waves excited by the diurnal Fourier harmonic of the prograde stellar irradiation. We also present a 2-dimensional plot of internal waves excited by the semi-diurnal component of the stellar irradiation and postulate that thermal bulges may arise in a hot Jupiter. Whether our postulation is valid and is consistent with the recent results from Arras & Socrates (2009b) requires further investigation.

Gu, P.-G.; Hsieh, H.-F.

2011-07-01

329

EVOLUTION OF OHMICALLY HEATED HOT JUPITERS  

SciTech Connect

We present calculations of thermal evolution of hot Jupiters with various masses and effective temperatures under ohmic dissipation. The resulting evolutionary sequences show a clear tendency toward inflated radii for effective temperatures that give rise to significant ionization of alkali metals in the atmosphere, compatible with the trend of the data. The degree of inflation shows that ohmic dissipation along with the likely variability in heavy element content can account for all of the currently detected radius anomalies. Furthermore, we find that in the absence of a massive core, low-mass hot Jupiters can overflow their Roche lobes and evaporate on Gyr timescales, possibly leaving behind small rocky cores.

Batygin, Konstantin; Stevenson, David J. [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Bodenheimer, Peter H., E-mail: kbatygin@gps.caltech.edu [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States)

2011-09-01

330

Semiempirical hot atom theory. I - Initialization and application  

NASA Technical Reports Server (NTRS)

A semiempirical approach to the modeling of the kinetics of reaction systems containing both hot and nonhot atoms is proposed. The approach is based on the probabilistic kinetic theory of hot-atom reactions formulated by Wolfgang (1963), with transmission probabilities estimated for a rectangular potential barrier for hot-atom and nonhot-atom reactions. A computational scheme for determining product concentrations following hot and nonhot reactions in a system containing photolytically produced hot atoms is then applied to the DBr + CH4 and HBr + CD4 hot hydrogen atom systems studied by Martin and Willard (1964), and good agreement is obtained between theoretical and experimental results.

Aronowitz, S.; Chang, S.; Scattergood, T.

1981-01-01

331

LASL hot dry rock geothermal project  

Microsoft Academic Search

Successful drilling into hard crystalline rock was accomplished to depths of about 3 km. Hydraulic fractures in the crystalline rock with radii as large as 150 m were produced. At least 90 to 95 percent of water injected into fractured regions was recovered. A connection was established between two deep boreholes through a fractured region of hot granite for the

A. G. Blair; J. W. Tester; J. J. Mortensen

1976-01-01

332

Hot Service Facility subsystem design description. Revision  

SciTech Connect

The Hot Service Facility Subsystem, which is also referred to as the Reactor Equipment Service Facility (RESF), is located in an environmentally controlled shielded vault and provides inspection, maintenance, care, and repair of reactor service equipment and tools. The shielded vault is located in the Reactor Service Building.

NONE

1987-07-01

333

Performance of segregated hot mix asphalt pavements  

Microsoft Academic Search

A laboratory study was conducted to evaluate the performance of segregated hot mix asphalt (HMA) pavements. The study involved simulating in-situ segregation of two current projects. Tests in the study were a laboratory wheel track test (PURWheel) and triaxial tests (including resilient modulus). For each project four segregation levels were determined based on field observation and subsequent analysis of gradation,

Zhenghao Wang

2000-01-01

334

Analysis of hot forging of porous metals  

Microsoft Academic Search

Thermomechanical elastoplastic problems in hot forging of the porous metals have been analysed using the thermoelastoplastic finite element method. This finite element program has been formulated using the yield condition advanced by Lee and Kim and developed using the thermoelastoplastic time integration procedure. A hardening law of non-porous metals as a function of temperature, plastic strain and strain rate is

Heung Nam Han; Yong-gi Lee; Kyu Hwan Oh; Dong Nyung Lee

1996-01-01

335

Hot deformation of duplex stainless steels  

Microsoft Academic Search

Duplex stainless steels (DSSs) have become established materials, successfully employed in many industrial applications. Their combination of mechanical properties and corrosion resistance is particularly appreciated in the petrochemical field. Hot deformation of these two-phase materials is still a critical point because the different mechanical response of austenite and ferrite often leads to the formation of edge cracks. In the present

J. M. Cabrera; A. Mateo; L. Llanes; J. M. Prado; M. Anglada

2003-01-01

336

Six Hot Topics in Planetary Astronomy  

E-print Network

Six hot topics in modern planetary astronomy are described: 1) lightcurves and densities of small bodies 2) colors of Kuiper belt objects and the distribution of the ultrared matter 3) spectroscopy and the crystallinity of ice in the outer Solar system 4) irregular satellites of the giant planets 5) the Main Belt Comets and 6) comets and meteor stream parents.

David Jewitt

2008-11-14

337

Plasmas are Hot and Fusion is Cool  

SciTech Connect

Plasmas are Hot and Fusion is Cold. The DOE Princeton Plasma Physics Laboratory (PPPL) collaborates to develop fusion as a safe, clean and abundant energy source for the future. This video discusses PPPL's research and development on plasma, the fourth state of matter.

None

2011-01-01

338

Nontuberculous mycobacterial disease following hot tub exposure.  

PubMed Central

Nontuberculous mycobacteria (NTM) have been recognized as an important cause of disease in immunocompromised hosts. Pulmonary disease caused by NTM is increasingly recognized in previously healthy persons. Investigation of pulmonary disease affecting a family of five identified an indoor hot tub as the source of NTM-related disease. PMID:11747738

Mangione, E. J.; Huitt, G.; Lenaway, D.; Beebe, J.; Bailey, A.; Figoski, M.; Rau, M. P.; Albrecht, K. D.; Yakrus, M. A.

2001-01-01

339

Prototype solar heating and hot water system  

NASA Technical Reports Server (NTRS)

Progress is reported in the development of a solar heating and hot water system which uses a pyramidal optics solar concentrator for heating, and consists of the following subsystems: collector, control, transport, and site data acquisition. Improvements made in the components and subsystems are discussed.

1977-01-01

340

Coatings for hot section gas turbine components  

Microsoft Academic Search

Components in the hot section of gas turbines are protected from the environment by oxidation-resistant coatings while thermal barrier coatings are applied to reduce the metal operating temperature of blades and vanes. The integrity of these protective coatings is an issue of major concern in current gas turbine designs. Premature cracking of the protective layer in oxidation-resistant coatings and of

J. Bressers; S. Peteves; M. Steen

2000-01-01

341

The US Hot Dry Rock project  

Microsoft Academic Search

The Hot Dry Rock geothermal energy project began in the early 1970's with the objective of developing a technology to make economically available the large ubiquitous thermal energy of the upper earth crust. The program has been funded by the Department of Energy (and its predecessors) and for a few years with participation by West Germany and Japan. An energy

Hendron

1987-01-01

342

Hot Dry Rock at Fenton Hill, USA  

Microsoft Academic Search

The Hot Dry Rock Geothermal Energy Project began in the early 1970's with the objective of developing a technology to make economically available the large ubiquitous thermal energy of the upper earth crust. The program, operated by the Los Alamos National Laboratory, has been funded by the Department of Energy (and its predecessors) and for a few years with participation

Hendron

1988-01-01

343

Storage capacity in hot dry rock reservoirs  

DOEpatents

A method is described for extracting thermal energy, in a cyclic manner, from geologic strata which may be termed hot dry rock. A reservoir comprised of hot fractured rock is established and water or other liquid is passed through the reservoir. The water is heated by the hot rock, recovered from the reservoir, cooled by extraction of heat by means of heat exchange apparatus on the surface, and then re-injected into the reservoir to be heated again. Water is added to the reservoir by means of an injection well and recovered from the reservoir by means of a production well. Water is continuously provided to the reservoir and continuously withdrawn from the reservoir at two different flow rates, a base rate and a peak rate. Increasing water flow from the base rate to the peak rate is accomplished by rapidly decreasing backpressure at the outlet of the production well in order to meet periodic needs for amounts of thermal energy greater than a baseload amount, such as to generate additional electric power to meet peak demands. The rate of flow of water provided to the hot dry rock reservoir is maintained at a value effective to prevent depletion of the liquid inventory of the reservoir. 4 figs.

Brown, D.W.

1997-11-11

344

Storage capacity in hot dry rock reservoirs  

DOEpatents

A method of extracting thermal energy, in a cyclic manner, from geologic strata which may be termed hot dry rock. A reservoir comprised of hot fractured rock is established and water or other liquid is passed through the reservoir. The water is heated by the hot rock, recovered from the reservoir, cooled by extraction of heat by means of heat exchange apparatus on the surface, and then re-injected into the reservoir to be heated again. Water is added to the reservoir by means of an injection well and recovered from the reservoir by means of a production well. Water is continuously provided to the reservoir and continuously withdrawn from the reservoir at two different flow rates, a base rate and a peak rate. Increasing water flow from the base rate to the peak rate is accomplished by rapidly decreasing backpressure at the outlet of the production well in order to meet periodic needs for amounts of thermal energy greater than a baseload amount, such as to generate additional electric power to meet peak demands. The rate of flow of water provided to the hot dry rock reservoir is maintained at a value effective to prevent depletion of the liquid

Brown, Donald W. (Los Alamos, NM)

1997-01-01

345

Hot oxygen coronas at terrestrial planets  

Microsoft Academic Search

Solar forcing via both influx of the solar wind plasma and absorption of ultraviolet radiation forms the hot oxygen coronas at the terrestrial planets (Shizgal and Arcos, 1996). These coronas were observed in the past and recent planetary space missions (Mariner, Pioneer Venus, IMAGE, Mars Express and etc.). We will dicsuss the relative role of the following energetic processes determining

V. I. Shematovich; R. E. Johnson

2006-01-01

346

A Smart Hot Swap Controller IC design  

Microsoft Academic Search

A hot swap controller IC was designed to ensure the safe insertion and removal of a circuit board from a live backplane. Multi protections including that against inrush current as well as the short circuit, load glitches, over-voltage and under-voltage occurring of both board and backplane were proposed in this design. Due to introduction of the Analog, Bipolar, CMOS and

Xiaolong Yuan; Xiaobo Wu; Menglian Zhao; Xiaolang Yan

2005-01-01

347

Minimizing the hot spots [IC design  

Microsoft Academic Search

The MOVER software allows IC designers to create a quick and accurate thermal profile of the chips they design. This program is particularly useful when gallium arsenide is used for the fabrication of semiconductors, as its low thermal conductivity can lead to local hot spots on the circuit die. In addition to the thermal profile, the MOVER program also suggests

Tom Volden; Joe Hootman

1995-01-01

348

Modelling recrystallization after hot deformation of aluminium  

Microsoft Academic Search

A physically based model for predicting recrystallization microstructures and textures after hot deformation of aluminium is presented. The modelling approach taken differs from similar models developed for steels. The present model is based on recent experimental investigations directed towards identifying the nature of the nucleation sites for recrystallized grains of different crystallographic orientations. Particle stimulated nucleation, nucleation from cube bands

H. E. Vatne; T. Furu; R. Ørsund; E. Nes

1996-01-01

349

Bog Hot Springs, Nevada: the geothermal cycle  

Microsoft Academic Search

The Bog Hot Springs are located in one of the high desert valleys of northern Nevada below the Pueblo Mountains. The flow of the springs is estimated to be 2,500 gpm. Temperatures range from 125 to 212°F. (JGB)

1977-01-01

350

Two New Hot Spots on Io  

NASA Technical Reports Server (NTRS)

The Near-Infrared Mapping Spectrometer (NIMS) on Galileo obtained this image of half of Io's disk in darkness on September 19, 1997. This image, at 5 microns, shows several hot spots on Io, which are volcanic regions of enhanced thermal emission. The area shown is part of the leading hemisphere of Io.

Two new hot spots are shown and indicated in the image (New, and Shamshu). Neither of these hot spots were seen by NIMS or the Solid State Imaging Experiment, (SSI) prior to this observation, becoming only recently active. Several other previously known hot spots are labelled in the image. Galileo was at a distance of 342,000 km from Io when this observation was made.

The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.

1997-01-01

351

Hot-dry-rock geothermal resource 1980  

SciTech Connect

The work performed on hot dry rock (HDR) geothermal resource evaluation, site characterization, and geophysical exploration techniques is summarized. The work was done by region (Far West, Pacific Northwest, Southwest, Rocky Mountain States, Midcontinent, and Eastern) and limited to the conterminous US.

Heiken, G.; Goff, F.; Cremer, G. (ed.)

1982-04-01

352

Extremophiles and their adaptation to hot environments  

Microsoft Academic Search

Water-containing terrestrial, subterranean and submarine high temperature areas harbor a variety of hyperthermophilic bacteria and archaea which are able to grow optimally above 80°C. Hyperthermophiles are adapted to hot environments by their physiological and nutritional requirements. As a consequence, cell components like proteins, nucleic acids and membranes have to be stable and even function best at temperatures around 100°C. The

Karl O Stetter

1999-01-01

353

Maximum power from a hot stream  

Microsoft Academic Search

This paper reports the solution to the fundamental problem of how to maximize the mechanical power extracted from a hot single-phase stream when the total heat transfer area bathed by the stream is constrained. It is shown that the optimization has two degrees of freedom: the shape of the stream temperature distribution as a function of the length (x) traveled

A. Bejan; M. R. Errera

1998-01-01

354

Towards Chemical Constraints on Hot Jupiter Migration  

E-print Network

The origin of hot Jupiters -- gas giant exoplanets orbiting very close to their host stars -- is a long-standing puzzle. Planet formation theories suggest that such planets are unlikely to have formed in-situ but instead may have formed at large orbital separations beyond the snow line and migrated inward to their present orbits. Two competing hypotheses suggest that the planets migrated either through interaction with the protoplanetary disk during their formation, or by disk-free mechanisms such as gravitational interactions with a third body. Observations of eccentricities and spin-orbit misalignments of hot Jupiter systems have been unable to differentiate between the two hypotheses. In the present work, we suggest that chemical depletions in hot Jupiter atmospheres might be able to constrain their migration mechanisms. We find that sub-solar carbon and oxygen abundances in Jovian-mass hot Jupiters around Sun-like stars are hard to explain by disk migration. Instead, such abundances are more readily expla...

Madhusudhan, Nikku; Kennedy, Grant M

2014-01-01

355

CONOCO DOLOMITE HOT GAS CLEANUP SYSTEM  

EPA Science Inventory

This report analyzes a proposal that EPA sponsor a large-scale pilot plant to develop the Conoco (formerly Consol) Dolomite Hot Gas Clean-up system. The report includes a history of the prior development program, the technology involved comparisons with competitive technologies i...

356

Teaching Earth Science Using Hot Air Balloons  

ERIC Educational Resources Information Center

Constructing model hot air balloons is an activity that captures the imaginations of students, enabling teachers to present required content to minds that are open to receive it. Additionally, there are few activities that lend themselves to integrating so much content across subject areas. In this article, the authors describe how they have…

Kuhl, James; Shaffer, Karen

2008-01-01

357

Fly a Hot-Air Balloon  

NSDL National Science Digital Library

Learners assemble a hot-air balloon from tissue paper. The heated air (from a heat gun) inside the balloon is less dense than the surrounding air and causes the balloon to float. Use this activity to introduce learners to density and convection currents. Adult supervision recommended when using the heat gun.

Museum Of Science And Industry, Chicago

2012-01-01

358

First Bites: Hot Skillet Hoisin Edamame [6  

E-print Network

First Bites: Hot Skillet Hoisin Edamame [6] Edamame Sautéed w/ Garlic Sambal Hoisin Glaze The Lab Cheese, Purple Basil, Green Goddess Dressing Spinach Artichoke Dip [8] Spinach, Artichoke Hearts, Garlic Onion, Wild Arugula, Tomato Relish, Garlic Aioli Gastronomy: The Lab Burger [12] Hand Pressed Meyer

Southern California, University of

359

First Bites Hot Skillet Hoisin Edamame [6  

E-print Network

First Bites Hot Skillet Hoisin Edamame [6] Edamame Sautéed w/ Garlic Sambal Hoisin Glaze Baked Hearts, Garlic, Mozzarella Cheese, Blue Cheese, Parmesan Cheese, Served w/ Crispy Pita Chip, Baby Beef Short Rib, Caramelized Sweet Onion, Wild Arugula, Tomato Relish, Garlic Aioli Crispy Calamari [10

Southern California, University of

360

Autoignition of droplets in hot air flow  

E-print Network

A single-droplet generator has been used to inject fuel droplets of various sizes and chemical composition into a hot turbulent air flow. The ensuing autoignition and flame behaviour has been recorded with a fast camera. The title of the movie...

Gordon, Robert; Mastorakos, Epaminondas

2010-09-09

361

Residential conservation demonstration program: domestic hot water  

Microsoft Academic Search

Four types of domestic hot water (DHW) systems installed in 80 homes throughout Florida are currently monitored by the Florida Solar Energy Center (FSEC) under a demonstration program for the Florida Public Service Commission. DHW systems selected for the program are located in four major population areas of Florida: Jacksonville, Orlando\\/Brevard County, North Palm Beach\\/Ft. Lauderdale, and the Tampa Bay

Merrigan

1982-01-01

362

Transfer of hot dry rock technology  

SciTech Connect

The Hot Dry Rock Geothermal Energy Development Program has focused worldwide attention on the facts that natural heat in the upper part of the earth's crust is an essentially inexhaustible energy resource which is accessible almost everywhere, and that practical means now exist to extract useful heat from the hot rock and bring it to the earth's surface for beneficial use. The Hot Dry Rock Program has successfully constructed and operated a prototype hot, dry rock energy system that produced heat at the temperatures and rates required for large-scale space heating and many other direct uses of heat. The Program is now in the final stages of constructing a larger, hotter system potentially capable of satisfying the energy requirements of a small, commercial, electrical-generating power plant. To create and understand the behavior of such system, it has been necessary to develop or support the development of a wide variety of equipment, instruments, techniques, and analyses. Much of this innovative technology has already been transferred to the private sector and to other research and development programs, and more is continuously being made available as its usefulness is demonstrated. This report describes some of these developments and indicates where this new technology is being used or can be useful to industry, engineering, and science.

Smith, M.C.

1985-11-01

363

Time to B. cereus about hot chocolate.  

PubMed Central

OBJECTIVE: To determine the cause of illnesses experienced by employees of a Minneapolis manufacturing plant after drinking hot chocolate bought from a vending machine and to explore the prevalence of similar vending machine-related illnesses. METHODS: The authors inspected the vending machines at the manufacturing plant where employees reported illnesses and at other locations in the city where hot chocolate beverages were sold in machines. Tests were performed on dry mix, water, and beverage samples and on machine parts. RESULTS: Laboratory analyses confirmed the presence of B. cereus in dispensed beverages at a concentration capable of causing illness (170,000 count/gm). In citywide testing of vending machines dispensing hot chocolate, 7 of the 39 licensed machines were found to be contaminated, with two contaminated machines having B. cereus levels capable of causing illness. CONCLUSIONS: Hot chocolate sold in vending machines may contain organisms capable of producing toxins that under favorable conditions, can induce illness. Such illnesses are likely to be underreported. Even low concentrations of B. cereus may be dangerous for vulnerable populations such as the aged or immunosuppressed. Periodic testing of vending machines is thus warranted. The relationship between cleaning practices and B. cereus contamination is an issue for further study. PMID:9160059

Nelms, P K; Larson, O; Barnes-Josiah, D

1997-01-01

364

Turbine Engine Hot Section Technology (HOST)  

NASA Technical Reports Server (NTRS)

Research and plans concerning aircraft gas turbine engine hot section durability problems were discussed. Under the topics of structural analysis, fatigue and fracture, surface protective coatings, combustion, turbine heat transfer, and instrumentation specific points addressed were the thermal and fluid environment around liners, blades, and vanes, material coatings, constitutive behavior, stress-strain response, and life prediction methods for the three components.

1982-01-01

365

A study of the hot working behavior of Al-Mg alloy 5052 by hot torsion testing  

NASA Astrophysics Data System (ADS)

The hot working behavior of commercial Al-2.5 wt pct Mg alloy 5052 was studied using hot torsion testing to simulate commercial hot rolling. The effects of homogenization time and temperature, and deformation temperature on the flow stress and hot ductility were carefully assessed. Microstructural characterizations and differential thermal analyses were performed to help explain the torsion data obtained. Significant variations in hot working behavior were noted for material machined from different regions of the commercial ingot studied. The constituent particles were found to play a significant role in determining the hot ductility of the alloy.

Precht, W.; Pickens, J. R.

1987-09-01

366

WESF hot cells waste minimization criteria hot cells window seals evaluation  

SciTech Connect

WESF will decouple from B Plant in the near future. WESF is attempting to minimize the contaminated solid waste in their hot cells and utilize B Plant to receive the waste before decoupling. WESF wishes to determine the minimum amount of contaminated waste that must be removed in order to allow minimum maintenance of the hot cells when they are placed in ''laid-up'' configuration. The remaining waste should not cause unacceptable window seal deterioration for the remaining life of the hot cells. This report investigates and analyzes the seal conditions and hot cell history and concludes that WESF should remove existing point sources, replace cerium window seals in F-Cell and refurbish all leaded windows (except for A-Cell). Work should be accomplished as soon as possible and at least within the next three years.

Walterskirchen, K.M.

1997-03-31

367

Hot moments and hot spots of nutrient losses from a mixed land use watershed  

NASA Astrophysics Data System (ADS)

SummaryNon-point nitrogen (N) and phosphorus (P) pollution from agriculture has increasingly received more public attention. In this study, NO 3-N, dissolved P (DP) and particulate P (PP) concentrations and loads were investigated for four sub-basins (labeled 1-4 going up the watershed) within a mixed land use watershed (39.5 ha) in the Appalachian Valley and Ridge Physiographic Province. The hot moments of NO 3-N concentration and load occurred in base flow and during the non-growing season. Great and temporally variable DP and PP concentrations were observed in storm flow. The hot moments of DP concentration and load were in storm flow from May to December and from September to Nov, respectively, while the hot moments of PP concentration and load were in storm flow from January to June. The NO 3-N, DP, and PP loads were compared for all four sub-basins on a loss per length of stream reach basis to determine the hot spots and their corresponding losses. The hot spots and hot moments of NO 3-N loads were in Sub-basins 1 and 4 during the non-growing season base flow period and Sub-basin 2 during the post-growing season base flow period (>110 g m -1 mo -1). The hot spots of DP loads were also in Sub-basins 1 and 4, but during the growing and post-growing season storm flow period (>1.4 g m -1 mo -1). In contrast, the hot spots and hot moments of PP load were in Sub-basin 3 during the pre-growing and growing season storm flow, as much as 13.4 and 14.1 g m -1 mo -1, respectively. Controlling factors of nutrient export were discussed in this study, including season, hydrology (base flow, storm flow, surface and subsurface runoff), and land use. Although different hot moments and hot spots within the watershed were identified for NO 3-N, DP, and PP losses, the implementation of a couple of management practices (cover crops and no-till) might be sufficient to effectively reduce nutrient losses from this and similar Valley and Ridge watersheds.

Zhu, Qing; Schmidt, John P.; Bryant, Ray B.

2012-01-01

368

Air Conditioner Efficiency Under Hot Dry and Hot Humid Conditions - The Utility Perspective  

E-print Network

Air Conditioner Efficiency under Hot Dry and Hot Humid Conditions - The Utility Perspective Ammi Amarnath Technical Leader, Energy Efficiency & Demand Response Program Electric Power Research Institute 3420 Hillview Avenue Palo Alto, CA... 94304 E-mail: aamarnath@epri.com Phone: (650) 855-1007 Energy efficient residential air conditioning is important to utilities and their customers. In almost all parts of the U.S., an air conditioner for a dwelling has a high peak demand...

Amarnath, A.

369

Processing maps for hot deformation of rolled AZ31 magnesium alloy plate: Anisotropy of hot workability  

Microsoft Academic Search

Processing maps on rolled AZ31 magnesium plate have been developed in the range 300–550°C and 0.0003–10s?1 by hot compression of specimens parallel to the rolling direction (RD), the transverse direction (TD), or the normal direction (ND) with a view to examine whether the hot workability is anisotropic. The processing map for RD specimens exhibited a single wide domain of workability

Y. V. R. K. Prasad; K. P. Rao

2008-01-01

370

HOT CELL BUILDING, TRA632, INTERIOR. CONTEXTUAL VIEW OF HOT CELL ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HOT CELL BUILDING, TRA-632, INTERIOR. CONTEXTUAL VIEW OF HOT CELL NO. 2 FROM STAIRWAY ALONG NORTH WALL. OBSERVATION WINDOW ALONG WEST SIDE BENEATH "CELL 2" SIGN. DOORWAY IN LEFT OF VIEW LEADS TO CELL 1 WORK AREA OR TO EXIT OUTDOORS TO NORTH. RADIATION DETECTION MONITOR TO RIGHT OF DOOR. CAMERA FACING SOUTHWEST. INL NEGATIVE NO. HD46-28-3. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

371

Lattice-Matched Hot Carrier Solar Cell with Energy Selectivity Integrated into Hot Carrier Absorber  

NASA Astrophysics Data System (ADS)

We propose a technologically feasible concept of a hot carrier (HC) solar cell (SC) which fulfills the electronic, optical, and to some extent the phononic criteria required. The energy selective process of HCs is implemented into the hot carrier absorber (HCA). Its electronic properties are investigated by a Monte-Carlo code which simulates random deviations of structure thickness and a normal distribution of random elastic electron (e-) scattering. The structure can be grown epitaxially as a HC-SC test device.

König, Dirk; Takeda, Yasuhiko; Puthen-Veettil, Binesh; Conibeer, Gavin

2012-10-01

372

2. SECTIONAL BOILER '#4 IDEAL RED FLASH.' Hot Springs ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. SECTIONAL BOILER '#4 IDEAL RED FLASH.' - Hot Springs National Park, Bathhouse Row, Ozark Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

373

12. ELEVATOR DOORS AND CAB. Hot Springs National Park, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. ELEVATOR DOORS AND CAB. - Hot Springs National Park, Bathhouse Row, Fordyce Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

374

10. NEEDLE SHOWER IN COOLING ROOM. Hot Springs National ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. NEEDLE SHOWER IN COOLING ROOM. - Hot Springs National Park, Bathhouse Row, Fordyce Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

375

5. HORIZONTAL COOLEDWATER STORAGE TANKS. Hot Springs National Park, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. HORIZONTAL COOLED-WATER STORAGE TANKS. - Hot Springs National Park, Bathhouse Row, Fordyce Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

376

7. COOLING TOWER FROM ROOF. Hot Springs National Park, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. COOLING TOWER FROM ROOF. - Hot Springs National Park, Bathhouse Row, Quapaw Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

377

15. FAN HOUSE ON TOP OF ELEVATOR SHAFT. Hot ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. FAN HOUSE ON TOP OF ELEVATOR SHAFT. - Hot Springs National Park, Bathhouse Row, Fordyce Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

378

3. BLOWER FAN, MOTOR AND DRIVE. Hot Springs National ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. BLOWER FAN, MOTOR AND DRIVE. - Hot Springs National Park, Bathhouse Row, Buckstaff Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 Mile North of U.S. Highway 70, Hot Springs, Garland County, AR

379

1. BLOWER (EXTERIOR CONFIGURATION). Hot Springs National Park Bathhouse ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. BLOWER (EXTERIOR CONFIGURATION). - Hot Springs National Park Bathhouse Row, Maurice Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

380

9. NEEDLE SHOWER IN MEN'S PACK ROOM. Hot Springs ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. NEEDLE SHOWER IN MEN'S PACK ROOM. - Hot Springs National Park Bathhouse Row, Maurice Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

381

5. DISCONNECTED COMPRESSOR MOTOR. Hot Springs National Park, Bathhouse ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. DISCONNECTED COMPRESSOR MOTOR. - Hot Springs National Park, Bathhouse Row, Quapaw Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

382

9. VAPOR STALL IN MEN'S BATH HALL. Hot Springs ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. VAPOR STALL IN MEN'S BATH HALL. - Hot Springs National Park, Bathhouse Row, Buckstaff Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 Mile North of U.S. Highway 70, Hot Springs, Garland County, AR

383

1. INDUSTRIAL IRON (WORKING SIDE). Hot Springs National Park, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. INDUSTRIAL IRON (WORKING SIDE). - Hot Springs National Park, Bathhouse Row, Quapaw Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

384

7. UNIT VENTILATOR, DETAIL OF MOTOR AND FANS. Hot ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. UNIT VENTILATOR, DETAIL OF MOTOR AND FANS. - Hot Springs National Park, Bathhouse Row, Ozark Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

385

2. INDUSTRIAL IRON (LAUNDRY AREA IN BACKGROUND). Hot Springs ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. INDUSTRIAL IRON (LAUNDRY AREA IN BACKGROUND). - Hot Springs National Park, Bathhouse Row, Quapaw Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

386

10. NEEDLE SHOWER IN WOMEN'S PACK ROOM. Hot Springs ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. NEEDLE SHOWER IN WOMEN'S PACK ROOM. - Hot Springs National Park, Bathhouse Row, Lamar Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

387

BLOWER MOTOR & DRIVE WHEEL. Hot Springs National Park, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

BLOWER MOTOR & DRIVE WHEEL. - Hot Springs National Park, Bathhouse Row, Superior Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

388

2. PLENUM WALL, SHOWING PNEUMATIC TUBES. Hot Springs National ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. PLENUM WALL, SHOWING PNEUMATIC TUBES. - Hot Springs National Park, Bathhouse Row, Lamar Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

389

1. PLENUM INTERIOR, SHOWING HEATING COILS AND BYPASS Hot ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. PLENUM INTERIOR, SHOWING HEATING COILS AND BY-PASS - Hot Springs National Park, Bathhouse Row, Fordyce Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

390

10. TYPICAL BATH IN MEN'S BATH HALL. Hot Springs ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. TYPICAL BATH IN MEN'S BATH HALL. - Hot Springs National Park, Bathhouse Row, Buckstaff Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 Mile North of U.S. Highway 70, Hot Springs, Garland County, AR

391

11. GENERAL VIEW OF MEN'S BATH HALL. Hot Springs ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. GENERAL VIEW OF MEN'S BATH HALL. - Hot Springs National Park, Bathhouse Row, Fordyce Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

392

7. BOILERS (MARINE TYPE). Hot Springs National Park, Bathhouse ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. BOILERS (MARINE TYPE). - Hot Springs National Park, Bathhouse Row, Buckstaff Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 Mile North of U.S. Highway 70, Hot Springs, Garland County, AR

393

8. HIGH POWER SPRAY IN MEN'S PACK ROOM. Hot ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. HIGH POWER SPRAY IN MEN'S PACK ROOM. - Hot Springs National Park Bathhouse Row, Maurice Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

394

13. DETAIL OF INTERIOR OF ELEVATOR SHAFT. Hot Springs ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. DETAIL OF INTERIOR OF ELEVATOR SHAFT. - Hot Springs National Park, Bathhouse Row, Fordyce Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

395

THERMALWATER FLOW METER. Hot Springs National Park, Bathhouse Row, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

THERMAL-WATER FLOW METER. - Hot Springs National Park, Bathhouse Row, Superior Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

396

11. INTERIOR OF THERMOSTAT. Hot Springs National Park Bathhouse ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. INTERIOR OF THERMOSTAT. - Hot Springs National Park Bathhouse Row, Maurice Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

397

DETAIL OF THERMALWATER FLOW METER. Hot Springs National Park, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL OF THERMAL-WATER FLOW METER. - Hot Springs National Park, Bathhouse Row, Superior Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

398

9. HIGH POWER SPRAY IN MEN'S STEAM ROOM. Hot ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. HIGH POWER SPRAY IN MEN'S STEAM ROOM. - Hot Springs National Park, Bathhouse Row, Fordyce Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

399

VACUUM PUMP (CONDENSATE RETURN). Hot Springs National Park, Bathhouse ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VACUUM PUMP (CONDENSATE RETURN). - Hot Springs National Park, Bathhouse Row, Hale Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

400

8. HUBBARD TUB IN MEN'S BATH HALL. Hot Springs ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. HUBBARD TUB IN MEN'S BATH HALL. - Hot Springs National Park, Bathhouse Row, Buckstaff Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 Mile North of U.S. Highway 70, Hot Springs, Garland County, AR

401

2. PADDLE FAN IN PLENUM INTERIOR. Hot Springs National ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. PADDLE FAN IN PLENUM INTERIOR. - Hot Springs National Park Bathhouse Row, Maurice Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

402

1. TEMPERING COILS IN WIND TUNNEL. Hot Springs National ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. TEMPERING COILS IN WIND TUNNEL. - Hot Springs National Park, Bathhouse Row, Buckstaff Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 Mile North of U.S. Highway 70, Hot Springs, Garland County, AR

403

4. DETAIL OF ELEVATOR DRUM AND DRIVE. Hot Springs ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. DETAIL OF ELEVATOR DRUM AND DRIVE. - Hot Springs National Park, Bathhouse Row, Fordyce Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

404

9. THERMOSTAT IN LADIES MASSAGE ROOM. Hot Springs National ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. THERMOSTAT IN LADIES MASSAGE ROOM. - Hot Springs National Park, Bathhouse Row, Lamar Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

405

4. VACUUM PUMP (CONDENSATE RETURN). Hot Springs National Park, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. VACUUM PUMP (CONDENSATE RETURN). - Hot Springs National Park, Bathhouse Row, Buckstaff Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 Mile North of U.S. Highway 70, Hot Springs, Garland County, AR

406

6. UNIT VENTILATOR, WOMEN'S COOLING ROOM. Hot Springs National ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. UNIT VENTILATOR, WOMEN'S COOLING ROOM. - Hot Springs National Park, Bathhouse Row, Ozark Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

407

5. FLOW METER AND PIPING SHOWING CONNECTIONS. Hot Springs ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. FLOW METER AND PIPING SHOWING CONNECTIONS. - Hot Springs National Park Bathhouse Row, Maurice Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

408

Children in Hot Cars Result in Fatal Consequences  

MedlinePLUS Videos and Cool Tools

... Travel & Motor Vehicle Safety En Español Holiday & Seasonal Children in Hot Cars Result in Fatal Consequences Emergency ... the overwhelming dangers associated with leaving anyone, especially children in hot, unventilated vehicles during the summer. Children ...

409

The High Albedo of the Hot Jupiter Kepler-7 B  

E-print Network

Hot Jupiters are expected to be dark from both observations (albedo upper limits) and theory (alkali metals and/or TiO and VO absorption). However, only a handful of hot Jupiters have been observed with high enough photometric ...

Demory, Brice-Olivier

410

CANADIAN METALLURGICAL QUARTERLY HOT WORKABILITY OF 2304 AND 2205 DUPLEX  

E-print Network

339 CANADIAN METALLURGICAL QUARTERLY HOT WORKABILITY OF 2304 AND 2205 DUPLEX STAINLESS STEELS E that the hot workability of 2304 and 2205 duplex stainless steels can be improved modestly by multistage

Niewczas, Marek

411

1. View of rmad from jr. hot cell, facing north ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. View of r-mad from jr. hot cell, facing north - Nevada Test Site, Reactor Maintenance & Disassembly Complex, Junior Hot Cell, Jackass Flats, Area 25, South of intersection of Roads F & G, Mercury, Nye County, NV

412

Photoabsorption in Hot Dense Plasmas W. R. Johnson  

E-print Network

Photoabsorption in Hot Dense Plasmas W. R. Johnson Department of Physics ­ 225 Nieuwland Science version of the time-dependent local-density approxi- mation designed to study photoabsorption in hot dense

Johnson, Walter R.

413

Continuous Commissioning of a Central Chilled Water & Hot Water System  

E-print Network

A central chilled water / hot water system provides cooling / heating energy from central utility plants to multiple customers (buildings) through campus distribution loops. To effectively transport the chilled water and hot water to the buildings...

Deng, S.; Turner, W. D.; Batten, T.; Liu, M.

2000-01-01

414

ConcepTest: Hot/Cold Water Circulation  

NSDL National Science Digital Library

A fish tank is filled almost to the brim with room temperature water. Two containers of cold and hot water are prepared. Red coloring is added to the hot water, blue coloring is added to the cold water. The cold ...

415

Losing Weight May Ease Hot Flashes, Study Finds  

MedlinePLUS

... page, please enable JavaScript. Losing Weight May Ease Hot Flashes, Study Finds Doctors say extra fat, and ... HealthDay News) -- Slimming down may help ease the hot flashes that often accompany menopause, new research suggests. ...

416

Hot-Film and Hot-Wire Anemometry for a Boundary Layer Active Flow Control Test  

NASA Technical Reports Server (NTRS)

Unsteady active flow control (AFC) has been used experimentally for many years to minimize bluff-body drag. This technology could significantly improve performance of rotorcraft by cleaning up flow separation. It is important, then, that new actuator technologies be studied for application to future vehicles. A boundary layer wind tunnel was constructed with a 1ft-x-3ft test section and unsteady measurement instrumentation to study how AFC manipulates the boundary layer to overcome adverse pressure gradients and flow separation. This unsteady flow control research requires unsteady measurement methods. In order to measure the boundary layer characteristics, both hot-wire and hot-film Constant Temperature Anemometry is used. A hot-wire probe is mounted in the flow to measure velocity while a hot-film array lays on the test surface to measure skin friction. Hot-film sensors are connected to an anemometer, a Wheatstone bridge circuit with an output that corresponds to the dynamic flow response. From this output, the time varying flow field, turbulence, and flow reversal can be characterized. Tuning the anemometers requires a fan test on the hot-film sensors to adjust each output. This is a delicate process as several variables drastically affect the data, including control resistance, signal input, trim, and gain settings.

Lenahan, Keven C.; Schatzman, David M.; Wilson, Jacob Samuel

2013-01-01

417

Evaluation of Energy Efficiency Measures in Hot and Humid Climates  

E-print Network

, the envelope and lighting design recommendations for projects in hot and humid climates (climate zones 1A and 2A) are: 1. Wall & Window Insulation: In hot/humid climates increased window and wall insulation does not necessarily provide increased energy..., the envelope and lighting design recommendations for projects in hot and humid climates (climate zones 1A and 2A) are: 1. Wall & Window Insulation: In hot/humid climates increased window and wall insulation does not necessarily provide increased energy...

Zhao, Y.; Erwine, B.; Leonard, P.; Pease, B.; Dole, A.; Lee, A.

418

Advances in Hot-Structure Development  

NASA Technical Reports Server (NTRS)

The National Aeronautics and Space Administration has actively participated in the development of hot structures technology for application to hypersonic flight systems. Hot structures have been developed for vehicles including the X-43A, X-37, and the Space Shuttle. These trans-atmospheric and atmospheric entry flight systems that incorporate hot-structures technology are lighter weight and require less maintenance than those that incorporate parasitic, thermal-protection materials that attach to warm or cool substructure. The development of hot structures requires a thorough understanding of material performance in an extreme environment, boundary conditions and load interactions, structural joint performance, and thermal and mechanical performance of integrated structural systems that operate at temperatures ranging from 1500 C to 3000 C, depending on the application. This paper will present recent advances in the development of hot structures, including development of environmentally durable, high temperature leading edges and control surfaces, integrated thermal protection systems, and repair technologies. The X-43A Mach-10 vehicle utilized carbon/carbon (C/C) leading edges on the nose, horizontal control surface, and vertical tail. The nose and vertical and horizontal tail leading edges were fabricated out of a 3:1 biased, high thermal conductivity C/C. The leading edges were coated with a three-layer coating comprised of a SiC conversion of the C/C, followed by a CVD layer of SiC, followed by a thin CVD layer of HfC. Work has also been performed on the development of an integrated structure and was focused on both hot and warm (insulated) structures and integrated fuselage/tank/TPS systems. The objective was to develop integrated multifunctional airframe structures that eliminate fragile external thermal-protection systems and incorporate the insulating function within the structure. The approach taken to achieve this goal was to develop candidate hypersonic airframe concepts, including structural arrangement, load paths, thermal-structural wall design, thermal accommodation features, and integration of major components, optimize thermalstructural configurations, and validate concepts through a building block test program and generate data to improve and validate analytical and design tools.

Rivers, H. Kevin; Glass, David E.

2006-01-01

419

Pipeline for conveying sulfur and other hot liquids  

Microsoft Academic Search

This is a composite-piping arrangement for conveying hot liquid material, such as molten sulfur, long distances, several miles or more, particularly from mines beneath the sea to onshore locations. The system consists of a central pipe for conveying the hot liquid, an insulating heating line larger than, and surrounding but unattached to the central pipe, through which hot fluid can

C. O. Lee; C. M. Cockrell

1965-01-01

420

Development of profile measuring system for hot solid wheels  

Microsoft Academic Search

The non-contact profile meter for hot railway solid wheels has been developed using capacitance sensors. The properties of the capacitance sensor are experimentally evaluated and analyzed both for the room temperature targets and for hot targets (up to about 800 degree Celsius). The developed profile meter measures the cross-sectional profiles of hot solid wheels of about 800 mm in diameter

Takashi Ashida; Tomonori Inui; Kejichi Yomoda; Hideto Kobayashi

1994-01-01

421

HATCH CONNECTING TEMPERED AIR CHAMBER AND HOT AIR CHAMBER OF ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HATCH CONNECTING TEMPERED AIR CHAMBER AND HOT AIR CHAMBER OF PLENUM WITH ATTACHED DRAFT REGULATOR. - Hot Springs National Park, Bathhouse Row, Superior Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

422

EFF HOT Topics. Volume 1, Number 1, Spring 2001  

ERIC Educational Resources Information Center

HOT Topics is a new quarterly publication from the Equipped for the Future (EFF) National Center. HOT stands for Highlights On Teaching, and this publication is committed to providing teachers and tutors with tools and ideas for teaching using the EFF Framework and Standards. This first issue of HOT Topics focuses on strategies that use the EFF…

National Institute for Literacy, 2001

2001-01-01

423

Optimization of Hot Gas Chamber in High Temperature Reactor  

Microsoft Academic Search

The flow field in the hot gas chamber of the High Temperature Gas Cooled Reactor (HTGCR) was studied with the Computational Fluid Dynamics (CFD) program CFX5. On the basis of the experimental studies, the velocity field, pressure field and temperature field in the hot gas chamber and hot gas duct were obtained, and the simulation's accuracy and reliability were validated

Jinhua WANG; Hanliang BO; Shengyao JIANG; Yuanhui XU; Wenxiang ZHENG

2004-01-01

424

HOT FORMING OF AISI A2 TOOL STEEL  

Microsoft Academic Search

For further increase of economy of production of AISI A2 tool steel a study of possibility of expanding the hot working range and better prediction of flow stress has been carried out. By employing hot compression tests it was proved, that initial microstructures have influence on the lower limit and chemical composition on upper limit of hot working range. A

T. Ve; R. Turk; G. Kugler; M. Ter; I. Peru

2008-01-01

425

Installation package for a solar heating and hot water system  

NASA Technical Reports Server (NTRS)

Development and installation of two commercial solar heating and hot water systems are reported. The systems consist of the following subsystems: collector, storage, transport, hot water, auxiliary energy and controls. General guidelines are provided which may be utilized in development of detailed installation plans and specifications. In addition, operation, maintenance and repair of a solar heating and hot water system instructions are included.

1978-01-01

426

Carbon Dioxide Challenge and Hot Flashes Sarah E. Dorsey1  

E-print Network

of Adult Health, School of Nursing Little is known about the pathophysiology of menopausal hot flashes provoke a hot flash in menopausal women. We hypothesize that women who have many hot flashes each day (4 women attended a study session lasting ninety minutes. In this placebo controlled, cross-over study

Zhou, Yaoqi

427

X-rays from Hot Stars: Stellar Astronomy Research with  

E-print Network

X-rays from Hot Stars: Stellar Astronomy Research with Swarthmore Students Professor David Cohen and how do the galaxy's most massive, hot, and luminous stars produce x-rays? The first x-ray telescopes unexpectedly discovered ubiquitous and strong x-ray emission from hot stars Einstein X-ray Observatory

Cohen, David

428

Feasibility of solar hot water systems in Vietnam  

Microsoft Academic Search

This study describes the prospects for solar hot water systems in Vietnam. Changes in domestic energy consumption, both in terms of quantity and patterns of usage, particularly the increase in electricity use for hot water systems, are expected. VIETSIM, a computer program for simulating solar hot water systems in Vietnam will be described. This program has been validated by comparing

B. T. Nguyen; T. L. Pryor

1998-01-01

429

Martian corona: Nonthermal sources of hot heavy species  

Microsoft Academic Search

We have studied the production of hot O and C atoms, and hot CO2 and CO molecules in the Martian upper atmosphere and exosphere by dissociative recombination (DR) of O2+ and CO+ ions, and sputtering of the atmosphere by incident O+ pick-up ions. Production and collisional thermalization of the hot particles in the upper atmosphere are described by using a

F. Cipriani; F. Leblanc; J. J. Berthelier

2007-01-01

430

Advanced high-temperature instrumentation for hot section researchapplications  

Microsoft Academic Search

Programs to develop research instrumentation for use in turbine engine hot sections are described. These programs were initiated to provide improved measurement capability as support for a multidisciplinary effort to establish technology leading to improved hot section durability. Specific measurement systems described here include heat flux sensors, a dynamic gas temperature measuring system, laser anemometry for hot section applications, an

D. R. Englund; R. G. Seasholtz

1989-01-01

431

25. Hot well, as seen from port side aft. Waste ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

25. Hot well, as seen from port side aft. Waste water overflow pipe appears at left, behind which is bilge pump. At base of hot well on either side are reciprocating boiler feedwater pumps driven from hot well crosshead. (Labels were applied by HAER recording team and are not original to equipment.) - Ferry TICONDEROGA, Route 7, Shelburne, Chittenden County, VT

432

Comparative greenhouse emissions analysis of domestic solar hot water systems  

Microsoft Academic Search

It is commonly assumed that solar hot water systems save energy and reduce greenhouse emissions relative to conventional fossil fuel-powered systems. Very rarely has the life-cycle greenhouse emissions (including the embodied greenhouse emissions of manufacture) of solar hot water systems been analysed. The extent to which solar hot water systems can reduce emissions compared with conventional systems can be shown

Robert H Crawford; Graham John Treloar; B. D. Ilozor; Peter Love

2003-01-01

433

10 CFR 431.102 - Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water...  

Code of Federal Regulations, 2011 CFR

...2011-01-01 false Definitions concerning commercial water heaters, hot water supply boilers...CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Water Heaters, Hot Water Supply...

2011-01-01

434

10 CFR 431.102 - Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water...  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Definitions concerning commercial water heaters, hot water supply boilers...CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Water Heaters, Hot Water Supply...

2010-01-01

435

10 CFR 431.102 - Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water...  

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Definitions concerning commercial water heaters, hot water supply boilers...CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Water Heaters, Hot Water Supply...

2013-01-01

436

10 CFR 431.102 - Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water...  

...2014-01-01 false Definitions concerning commercial water heaters, hot water supply boilers...CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Water Heaters, Hot Water Supply...

2014-01-01

437

10 CFR 431.102 - Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water...  

Code of Federal Regulations, 2012 CFR

...2012-01-01 false Definitions concerning commercial water heaters, hot water supply boilers...CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Water Heaters, Hot Water Supply...

2012-01-01

438

Magnetic Effects in Hot Jupiter Atmospheres  

E-print Network

We present magnetohydrodynamic (MHD) simulations of the atmospheres of hot Jupiters ranging in temperature from 1100-1800K. Magnetic effects are negligible in atmospheres with temperatures $\\lesssim$ 1400K. At higher temperatures winds are variable and in many cases, mean equatorial flows can become westward, opposite to their hydrodynamic counterparts. Ohmic dissipation peaks at temperatures $\\sim$1500-1600K, depending on field strength, with maximum values $\\sim 10^{18}$W at 10bar, substantially lower than previous estimates. Based on the limited parameter study done, this value can not be increased substantially with increasing winds, higher temperatures, higher field strengths, different boundary conditions or lower diffusivities. Although not resolved in these simulations there is modest evidence that a magnetic buoyancy instability may proceed in hot atmospheres.

Rogers, Tamara M

2014-01-01

439

Effects of a hot intergalactic medium  

NASA Technical Reports Server (NTRS)

One effect a hot intergalactic medium (IGM) would have would be to produce an isotropic X-ray background through thermal bremsstrahlung. Such a background was modeled including both relativistic electron-ion and electron-electron emission; the observed X-ray measurements could be fit with a current temperature of 10.2 keV and Omega (IGM) of 0.27, assuming that the IGM was instantaneously heated at a redshift of 5 and cools by relativistic adiabatic expansion and Compton cooling. Such a hot IGM would also distort the cosmic microwave background spectrum by inverse Compton scattering off relativistic electrons. This distortion was modeled using the relativistic treatment. When including the recent data of Matsumoto et al., an undistorted radiation temperature of 2.86 K and an Omega (IGM) of 0.41 was found.

Taylor, Gregory B.; Wright, Edward L.

1989-01-01

440

An Optimization Study of Hot Stamping Operation  

NASA Astrophysics Data System (ADS)

In the present study, 3-dimensional finite element analyses for hot-stamping processes of Audi B-pillar product are conducted using JSTAMP/NV and HEEDS. Special attention is paid to the optimization of simulation technology coupling with thermal-mechanical formulations. Numerical simulation based on FEM technology and optimization design using the hybrid adaptive SHERPA algorithm are applied to hot stamping operation to improve productivity. The robustness of the SHERPA algorithm is found through the results of the benchmark example. The SHERPA algorithm is shown to be far superior to the GA (Genetic Algorithm) in terms of efficiency, whose calculation time is about 7 times faster than that of the GA. The SHERPA algorithm could show high performance in a large scale problem having complicated design space and long calculation time.

Ghoo, Bonyoung; Umezu, Yasuyoshi; Watanabe, Yuko; Ma, Ninshu; Averill, Ron

2010-06-01

441

Hot water can freeze faster than cold?!?  

E-print Network

We review the Mpemba effect, where intially hot water freezes faster than initially cold water. While the effect appears impossible at first sight, it has been seen in numerous experiments, was reported on by Aristotle, Francis Bacon, and Descartes, and has been well-known as folklore around the world. It has a rich and fascinating history, which culminates in the dramatic story of the secondary school student, Erasto Mpemba, who reintroduced the effect to the twentieth century scientific community. The phenomenon, while simple to describe, is deceptively complex, and illustrates numerous important issues about the scientific method: the role of skepticism in scientific inquiry, the influence of theory on experiment and observation, the need for precision in the statement of a scientific hypothesis, and the nature of falsifiability. We survey proposed theoretical mechanisms for the Mpemba effect, and the results of modern experiments on the phenomenon. Studies of the observation that hot water pipes are more ...

Jeng, M

2005-01-01

442

Fluid cooled hot duct liner structure  

SciTech Connect

This patent describes a liner structure for a hot gas duct in a gas turbine engine or the like. It comprises a generally tubular shaped wall member defining a duct for conducting hot gas from an upstream end to a downstream end along a central axis thereof; a second plurality of axially spaced vee-shaped vanes disposed on each the ridge, each the vane having a pair of legs divergent toward the downstream end of the duct; an elongated cap disposed along each the ridge atop corresponding the vanes, the cap and corresponding vanes defining a corresponding plurality of slots between the cap and ridge; and means defining a third plurality of holes through the wall member at each the ridge and between axially adjacent vanes for conducting fluid coolant through the wall member.

Field, R.E.

1992-09-08

443

HOT WATER DRILL FOR TEMPERATE ICE.  

USGS Publications Warehouse

The development of a high-pressure hot-water drill is described, which has been used reliably in temperate ice to depths of 400 meters with an average drill rate of about 1. 5 meters per minute. One arrangement of the equipment weighs about 500 kilograms, and can be contained on two sleds, each about 3 meters long. Simplified performance equations are given, and experiments with nozzle design suggest a characteristic number describing the efficiency of each design, and a minimum bore-hole diameter very close to 6 centimeters for a hot water drill. Also discussed is field experience with cold weather, water supply, and contact with englacial cavities and the glacier bed.

Taylor, Philip, L.

1984-01-01

444

Hot spots in an athermal system.  

PubMed

We study experimentally the dynamical heterogeneities occurring at slow shear, in a model amorphous glassy material, i.e., a 3D granular packing. The deformation field is resolved spatially by using a diffusive wave spectroscopy technique. The heterogeneities show up as localized regions of strong deformations spanning a mesoscopic size of about 10 grains and called the "hot spots." The spatial clustering of hot spots is linked to the subsequent emergence of shear bands. Quantitatively, their appearance is associated with the macroscopic plastic deformation, and their rate of occurrence gives a physical meaning to the concept of "fluidity," recently used to describe the local and nonlocal rheology of soft glassy materials. PMID:22540713

Amon, Axelle; Nguyen, Van Bau; Bruand, Ary; Crassous, Jérôme; Clément, Eric

2012-03-30

445

Enabling Technologies for Ceramic Hot Section Components  

SciTech Connect

Silicon-based ceramics are attractive materials for use in gas turbine engine hot sections due to their high temperature mechanical and physical properties as well as lower density than metals. The advantages of utilizing ceramic hot section components include weight reduction, and improved efficiency as well as enhanced power output and lower emissions as a result of reducing or eliminating cooling. Potential gas turbine ceramic components for industrial, commercial and/or military high temperature turbine applications include combustor liners, vanes, rotors, and shrouds. These components require materials that can withstand high temperatures and pressures for long duration under steam-rich environments. For Navy applications, ceramic hot section components have the potential to increase the operation range. The amount of weight reduced by utilizing a lighter gas turbine can be used to increase fuel storage capacity while a more efficient gas turbine consumes less fuel. Both improvements enable a longer operation range for Navy ships and aircraft. Ceramic hot section components will also be beneficial to the Navy's Growth Joint Strike Fighter (JSF) and VAATE (Versatile Affordable Advanced Turbine Engines) initiatives in terms of reduced weight, cooling air savings, and capability/cost index (CCI). For DOE applications, ceramic hot section components provide an avenue to achieve low emissions while improving efficiency. Combustors made of ceramic material can withstand higher wall temperatures and require less cooling air. Ability of the ceramics to withstand high temperatures enables novel combustor designs that have reduced NO{sub x}, smoke and CO levels. In the turbine section, ceramic vanes and blades do not require sophisticated cooling schemes currently used for metal components. The saved cooling air could be used to further improve efficiency and power output. The objectives of this contract were to develop technologies critical for ceramic hot section components for gas turbine engines. Significant technical progress has been made towards maturation of the EBC and CMC technologies for incorporation into gas turbine engine hot-section. Promising EBC candidates for longer life and/or higher temperature applications relative to current state of the art BSAS-based EBCs have been identified. These next generation coating systems have been scaled-up from coupons to components and are currently being field tested in Solar Centaur 50S engine. CMC combustor liners were designed, fabricated and tested in a FT8 sector rig to demonstrate the benefits of a high temperature material system. Pretest predictions made through the use of perfectly stirred reactor models showed a 2-3x benefit in CO emissions for CMC versus metallic liners. The sector-rig test validated the pretest predictions with >2x benefit in CO at the same NOx levels at various load conditions. The CMC liners also survived several trip shut downs thereby validating the CMC design methodology. Significant technical progress has been made towards incorporation of ceramic matrix composites (CMC) and environmental barrier coatings (EBC) technologies into gas turbine engine hot-section. The second phase of the program focused on the demonstration of a reverse flow annular CMC combustor. This has included overcoming the challenges of design and fabrication of CMCs into 'complex' shapes; developing processing to apply EBCs to 'engine hardware'; testing of an advanced combustor enabled by CMCs in a PW206 rig; and the validation of performance benefits against a metal baseline. The rig test validated many of the pretest predictions with a 40-50% reduction in pattern factor compared to the baseline and reductions in NOx levels at maximum power conditions. The next steps are to develop an understanding of the life limiting mechanisms in EBC and CMC materials, developing a design system for EBC coated CMCs and durability testing in an engine environment.

Venkat Vedula; Tania Bhatia

2009-04-30

446

Karhula hot gas cleanup test results  

SciTech Connect

The objective of this work is to develop a practical hot gas filter design that meets the performance and operational requirements of pressurized fluidized bed combustion--bubbling bed, circulating bed and second generation--applications. The Westinghouse hot gas candle filter system is currently installed in the Ahlstrom Pyropower 10 MW (thermal) pressurized circulating fluidized bed combustor (PCFB) test facility located in Karhula, Finland. The overall objective of the testing is to evaluate the filter design and operating reliability for selection and implementation into the Midwest Power DMEC-1 PCFB 150 MW(e) repowering project (Clean Coal III Selection). During 1,026 hours of operation represented by Test Segment 2 and current testing in Test Segment 3, the filter unit and test facility has performed very well and operated without major equipment failures. The filter has demonstrated stable pressure drop and has operated without candle failure. Tables summarize the filter operating parameters during these tests.

Lippert, T.E.; Bruck, G.J. [Westinghouse Electric Corp., Pittsburgh, PA (United States). Science and Technology Center; Isaksson, J. [Ahlstrom Pyropower, Karhula (Finland)

1994-10-01

447

Hot-water power from the earth  

SciTech Connect

This article examines geothermal sites on the West Coast in order to show the progress that has been made in converting geothermal energy into usable electric power. Only about 0.5% of the earth's geothermal reserve can be brought to the surface as dry steam. California's Imperial Valley is possibly the largest geothermal resource in the US. Three demonstration generating plants are each producing between 10 and 14 MW of power near the valley's Salton Sea. The high-temperature water (above 410/sup 0/F) at Brawley is drawn from wells tapping the subterranean reservoir. It is proposed that hot-water power will be economical when methods are found to extract maximum energy from a geothermal deposit and to control clogging and corrosion caused by minerals dissolved in the hot fluid.

Not Available

1984-02-01

448

Session 8: Hot Dry Rock Update  

SciTech Connect

In 1970, Los Alamos began an informal study of the possible usefulness of hot dry rock (HDR) energy systems based on circulation of water through hydraulic fractures connecting two wellbores drilled into hot crustal rock of low initial permeability and free-water content. In 1973 this was established as a formal HDR Program. It has since been sponsored by DOE and its predecessor agencies, with supplementary support since 1980 by agencies of the governments of West Germany and Japan. In the meantime, complementary HDR projects have been initiated in Germany, Japan, the United Kingdom, Sweden, France, and the Soviet Union, and several other countries have undertaken HDR resource evaluations and theoretical background studies. The HDR Program is now truly international, although the broadest and most advanced effort is still at Los Alamos.

Whetten, John; Brown, David; Potter, Robert

1983-12-01

449

Magnetic Effects in Hot Jupiter Atmospheres  

NASA Astrophysics Data System (ADS)

We present magnetohydrodynamic simulations of the atmospheres of hot Jupiters ranging in temperature from 1100 to 1800 K. Magnetic effects are negligible in atmospheres with temperatures lsim1400 K. At higher temperatures winds are variable and, in many cases, mean equatorial flows can become westward, opposite to their hydrodynamic counterparts. Ohmic dissipation peaks at temperatures ~1500-1600 K, depending on field strength, with maximum values ~1018 W at 10 bars, substantially lower than previous estimates. Based on the limited parameter study done, this value cannot be increased substantially with increasing winds, higher temperatures, higher field strengths, different boundary conditions, or lower diffusivities. Although not resolved in these simulations, there is modest evidence that a magnetic buoyancy instability may proceed in hot atmospheres.

Rogers, T. M.; Komacek, T. D.

2014-10-01

450

Turbine Engine Hot Section Technology 1986  

NASA Technical Reports Server (NTRS)

The Turbine Engine Hot Section Technology (HOST) Project of the NASA Lewis Research Center sponsored a workshop to discuss current research pertinent to turbine engine durability problems. Presentations were made concerning the hot section environment and the behavior of combustion liners, turbine blades, and turbine vanes. The presentations were divided into six sessions: Instrumentation, Combustion, Turbine Heat Transfer, Structural Analysis, Fatigue and Fracture, and Surface Protection. Topics discussed included modeling of thermal and fluid-flow phenomena, structural analysis, fatigue and fracture, surface protective coatings, constitutive behavior of materials, stress-strain response, and life-prediction methods. Researchers from industry, academia, and government presented results of their work sponsored by the HOST project.

1986-01-01

451

Hot Flashes and Carotid Intima Media Thickness among Midlife Women  

PubMed Central

Objective Emerging evidence suggests associations between menopausal hot flashes and cardiovascular risk. Whether hot flashes are associated with intima media thickness (IMT) or IMT changes over time is unknown. We hypothesized that reported hot flashes would be associated with greater IMT cross-sectionally and with greater IMT progression over two years. Methods Participants were 432 women ages 45-58 at baseline participating in SWAN Heart, an ancillary study to the Study of Women's Health Across the Nation. Measures at the SWAN Heart baseline and follow-up visit two years later included a carotid artery ultrasound, reported hot flashes (past two weeks: none, 1-5, ?6 days), and a blood sample for measurement of estradiol. Results Women reporting hot flashes ?6 days in the prior two weeks had significantly higher IMT than women without hot flashes at baseline (mean difference(SE), mm =0.02(0.01), p=0.03) and follow-up (mean difference(SE), mm =0.02(0.01), p=0.04) visits, controlling for demographic factors and cardiovascular risk factors. Reporting hot flashes at both study visits was associated with higher follow-up IMT relative to reporting hot flashes at neither visit (mean difference(SE), mm=0.03(0.01), p=0.03). Associations between hot flashes and IMT largely remained after adjusting for estradiol. An interaction between hot flashes and obesity status was observed (p=0.05) such that relations between hot flashes and IMT were observed principally among overweight/obese women. Hot flashes were not associated with IMT progression. Conclusions These findings provided some indication that women reporting hot flashes ?6 days in the prior two weeks may have higher IMT than women without hot flashes, particularly for women who are overweight or obese. Further work should determine whether hot flashes mark adverse underlying vascular changes. PMID:21242820

Thurston, Rebecca C.; Sutton-Tyrrell, Kim; Everson-Rose, Susan A.; Hess, Rachel; Powell, Lynda H.; Matthews, Karen A.

2010-01-01

452

Hot corrosion of the B2 nickel aluminides  

NASA Technical Reports Server (NTRS)

The hot corrosion behavior of the B2 nickel aluminides was studied to determine the inherent hot corrosion resistance of the beta nickel aluminides and to develop a mechanism for the hot corrosion of the beta nickel aluminides. The effects of the prior processing of the material, small additions of zirconium, stoichiometry of the materials, and preoxidation of the samples were also examined. Additions of 2, 5, and 15 w/o chromium were used to determine the effect of chromium on the hot corrosion of the beta nickel aluminides and the minimum amount of chromium necessary for good hot corrosion resistance. The results indicate that the beta nickel aluminides have inferior inherent hot corrosion resistance despite their excellent oxidation resistance. Prior processing and zirconium additions had no discernible effect on the hot corrosion resistance of the alloys. Preoxidation extended the incubation period of the alloys only a few hours and was not considered to be an effective means of stopping hot corrosion. Stoichiometry was a major factor in determining the hot corrosion resistance of the alloys with the higher aluminum alloys having a definitely superior hot corrosion resistance. The addition of chromium to the alloys stopped the hot corrosion attack in the alloys tested. From a variety of experimental results, a complex hot corrosion mechanism was proposed. During the early stages of the hot corrosion of these alloys the corrosion is dominated by a local sulphidation/oxidation form of attack. During the intermediate stages of the hot corrosion, the aluminum depletion at the surface leads to a change in the oxidation mechanism from a protective external alumina layer to a mixed nickel-aluminum spinel and nickel oxide that can occur both externally and internally. The material undergoes extensive cracking during the later portions of the hot corrosion.

Ellis, David L.

1993-01-01

453

Turbine Engine Hot Section Technology, 1984  

NASA Technical Reports Server (NTRS)

Presentations were made concerning the hot section environment and behavior of combustion liners, turbine blades, and waves. The presentations were divided into six sessions: instrumentation, combustion, turbine heat transfer, structural analysis, fatigue and fracture, and surface properties. The principal objective of each session was to disseminate research results to date, along with future plans. Topics discussed included modeling of thermal and fluid flow phenomena, structural analysis, fatigue and fracture, surface protective coatings, constitutive behavior, stress-strain response, and life prediction methods.

1984-01-01

454

Drowning and the Influence of Hot Weather  

PubMed Central

Background Drowning deaths are devastating and preventable. Public perception does not regard hot weather as a common scenario for drowning deaths. The objective of our study was to test the association between hot weather and drowning risk. Materials and Methods We conducted a retrospective case-crossover analysis of all unintentional drowning deaths in Ontario, Canada from 1999 to 2009. Demographic data were obtained from the Office of the Chief Coroner. Weather data were obtained from Environment Canada. We used the pair-matched analytic approach for the case-crossover design to contrast the weather on the date of the drowning with the weather at the same location one week prior (control period). Results We identified 1243 drowning deaths. The mean age was 40 years, 82% were male, and most events (71%) occurred in open water. The pair-matched analytic approach indicated that temperatures exceeding 30°C were associated with a 69% increase in the risk of outdoor drowning (OR?=?1.69, 95% CI 1.23–2.25, p?=?0.001). For indoor drowning, however, temperatures exceeding 30°C were not associated with a statistically significant increase in the risk of drowning (OR?=?1.50, 95% CI 0.53–4.21, p?=?0.442). Adult men were specifically prone to drown in hot weather (OR 1.67, 95% CI 1.19–2.34, p?=?0.003) yet an apparent increase in risk extended to both genders and all age groups. Conclusion Contrary to popular belief, hot weather rather than cold stormy weather increases the risk of drowning. An awareness of this risk might encourage greater use of drowning prevention strategies known to save lives. PMID:23977112

Fralick, Michael; Denny, Christopher J.; Redelmeier, Donald A.

2013-01-01

455

Thermal Processes Governing Hot-Jupiter Radii  

NASA Astrophysics Data System (ADS)

There have been many proposed explanations for the larger-than-expected radii of some transiting hot Jupiters, including either stellar or orbital energy deposition deep in the atmosphere or deep in the interior. In this paper, we explore the important influences on hot-Jupiter radius evolution of (1) additional heat sources in the high atmosphere, the deep atmosphere, and deep in the convective interior; (2) consistent cooling of the deep interior through the planetary dayside, nightside, and poles; (3) the degree of heat redistribution to the nightside; and (4) the presence of an upper atmosphere absorber inferred to produce anomalously hot upper atmospheres and inversions in some close-in giant planets. In particular, we compare the radius expansion effects of atmospheric and deep-interior heating at the same power levels and derive the power required to achieve a given radius increase when night-side cooling is incorporated. We find that models that include consistent day/night cooling are more similar to isotropically irradiated models when there is more heat redistributed from the dayside to the nightside. In addition, we consider the efficacy of ohmic heating in the atmosphere and/or convective interior in inflating hot Jupiters. Among our conclusions are that (1) the most highly irradiated planets cannot stably have uB >~ 10 km s-1 G over a large fraction of their daysides, where u is the zonal wind speed and B is the dipolar magnetic field strength in the atmosphere, and (2) that ohmic heating cannot in and of itself lead to a runaway in planet radius.

Spiegel, David S.; Burrows, Adam

2013-07-01

456

Sustainable Energy - Without the hot air  

Microsoft Academic Search

Reader John Roeder writes about a website associated with David MacKay's book Sustainable Energy-Without the hot air. The book is a freely downloadable PDF (or purchasable) book describing an analysis detailing a low-carbon renewable energy transformation route for a large, modern first world industrial country (the United Kingdom). Written for the layman, the work uses vernacular language, e.g., energy consumption

Dan MacIsaac

2009-01-01

457

The hot plasma spectrometers on Freja  

Microsoft Academic Search

The hot plasma instrumentation F3H on the Swedish-German Freja satellite due for launch in 1992 will consist of electron and ion spectrometers. The spectrometer Magnetic imaging Two dimensional Electron (MATE) will measure the two dimensional electron distribution in the spin plane in the energy range 0.1 to 120 keV. The ion mass spectrometer Three dimensional Ion Composition Spectrometer (TICS) measures

O. Norberg; L. Eliasson

1991-01-01

458

Menopausal Women's Perceived Causes of Hot Flash  

Microsoft Academic Search

This descriptive study examined the perceptions of a group of breast cancer survivors about the causes of their hot flashes. Thirty-nine participants readily offered 1,008 individual responses. A content analysis revealed four prominent categories (stress, pain, medication related, and lack of sleep) as well as others (e.g., food related, heat related). In the context of concerns about biomedical approaches to

Margaret L. Stubbs; Susan M. Cohen; Feridey Carr

2008-01-01

459

Elementary processes in silicon hot wire CVD  

Microsoft Academic Search

The reaction kinetics for the silicon hot-wire chemical vapor deposition (HWCVD) method has been investigated. A time of flight mass spectroscopy (TOF-MS) with a VUV (Vacuum Ultra Violet) single photon ionization technique was used to detect the gas phase chemical species. Si2H6 and Si3H8 were identified as the main gas phase species during the HWCVD film growth processes in the

Seigo Nakamura; Mitsuo Koshi

2006-01-01

460

Hot isostatic processing of metal matrix composites  

Microsoft Academic Search

The effect of four different Hot Isostatic Pressing (HIPping) treatments on porosity in the aluminium casting alloy A357 and stir-cast A357\\/15 vol% SiC particulate MMC has been investigated and the optimum treatment identified. The bend strength increased after HIPping relative to as-received. Such ceramic particle reinforced MMCs, however, do not have adequate toughness for many commercial applications. Metal reinforced MMCs

H. V Atkinson; A Zulfia; A Lima Filho; H Jones; S King

1997-01-01

461

Hot hydrogen in prebiological and interstellar chemistry  

NASA Technical Reports Server (NTRS)

Two articles discuss the recent experimental work of Hong et al. on the production of amino acids and gas-phase organic compounds from the ultraviolet irradiation of simple gases, with hot hydrogen atoms used as the principal energy conversion agent. The reaction possibilities involving frozen ices are mentioned in both articles, as well as the significance of three-body collisions in this situation.

Sagan, C.

1975-01-01

462

Ethylene oxide and acetaldehyde in hot cores  

NASA Astrophysics Data System (ADS)

Context. Ethylene oxide (c-C2H4O), and its isomer acetaldehyde (CH3CHO), are important complex organic molecules because of their potential role in the formation of amino acids. The discovery of ethylene oxide in hot cores suggests the presence of ring-shaped molecules with more than 3 carbon atoms such as furan (c-C4H4O), to which ribose, the sugar found in DNA, is closely related. Aims: Despite the fact that acetaldehyde is ubiquitous in the interstellar medium, ethylene oxide has not yet been detected in cold sources. We aim to understand the chemistry of the formation and loss of ethylene oxide in hot and cold interstellar objects (i) by including in a revised gas-grain network some recent experimental results on grain surfaces and (ii) by comparison with the chemical behaviour of its isomer, acetaldehyde. Methods: We introduce a complete chemical network for ethylene oxide using a revised gas-grain chemical model. We test the code for the case of a hot core. The model allows us to predict the gaseous and solid ethylene oxide abundances during a cooling-down phase prior to star formation and during the subsequent warm-up phase. We can therefore predict at what temperatures ethylene oxide forms on grain surfaces and at what temperature it starts to desorb into the gas phase. Results: The model reproduces the observed gaseous abundances of ethylene oxide and acetaldehyde towards high-mass star-forming regions. In addition, our results show that ethylene oxide may be present in outer and cooler regions of hot cores where its isomer has already been detected. Our new results are compared with previous results, which focused on the formation of ethylene oxide only. Conclusions: Despite their different chemical structures, the chemistry of ethylene oxide is coupled to that of acetaldehyde, suggesting that acetaldehyde may be used as a tracer for ethylene oxide towards cold cores.

Occhiogrosso, A.; Vasyunin, A.; Herbst, E.; Viti, S.; Ward, M. D.; Price, S. D.; Brown, W. A.

2014-04-01

463

Day and Night on Hot Jupiters  

Microsoft Academic Search

Recent observations of the secondary eclipse of the `Hot Jupiter' planet HD209458b suggest that the planet may reradiate most and perhaps all of the irradiation it receives from its host star on the side facing the star i.e. that there is little redistribution of energy around the surface of the planet. An immediate implication of this day\\/night temperature difference is

Bradley Hansen; James Cho; Drake Deming; Joe Harrington; Kristen Menou; Jeremy Richardson; Sara Seager

2005-01-01

464

PARTICULATE HOT GAS STREAM CLEANUP TECHNICAL ISSUES  

Microsoft Academic Search

This quarterly report describes technical activities performed under Contract No. DE-AC21-94MC31160. The analyses of hot gas stream cleanup (HGCU) ashes and descriptions of filter performance studied under Task 1 of this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. This report reviews the status of the HGCU data bank

D. H. Pontius

1999-01-01

465

Weldability and hot ductility of iron aluminides  

SciTech Connect

The weldability of iron aluminide alloys is discussed. Although readily welded with electron beam (EB) and gas-tungsten arc (GTA) techniques, iron aluminides are sometimes susceptible to cracking during cooling when welded with the GTA welding process. Taken into account are the effects of microstructural instability (grain growth), weld heat input (cooling rate) and environment on the hot ductility of an iron aluminide alloy designated FA-129. 64 refs., 59 figs., 3 tabs.

Ash, D.I.; Edwards, G.R. (Colorado School of Mines, Golden, CO (United States). Center for Welding and Joining Research); David, S.A. (Oak Ridge National Lab., TN (United States))

1991-05-01

466

Plasmonically enhanced hot electron based photovoltaic device.  

PubMed

Hot electron photovoltaics is emerging as a candidate for low cost and ultra thin solar cells. Plasmonic means can be utilized to significantly boost device efficiency. We separately form the tunneling metal-insulator-metal (MIM) junction for electron collection and the plasmon exciting MIM structure on top of each other, which provides high flexibility in plasmonic design and tunneling MIM design separately. We demonstrate close to one order of magnitude enhancement in the short circuit current at the resonance wavelengths. PMID:23546103

Atar, Fatih B; Battal, Enes; Aygun, Levent E; Daglar, Bihter; Bayindir, Mehmet; Okyay, Ali K

2013-03-25

467

Probe Samples And Cools Hot Gas  

NASA Technical Reports Server (NTRS)

Simple concentric-tube gas-sampling probe, developed to sample hot gas streams. Includes straight outer tube and inner tube, bent to be concentric to outer tube at one end and tangent to outer tube in sampling region at other end. Two tubes brazed together along sampling region and at end to prevent sampled gas and cooling stream from mixing. Inner tube contains sampled gas, and space outside inner tube but inside outer tube path for cooling stream.

Schultz, Donald F.

1989-01-01

468

THERMAL PROCESSES GOVERNING HOT-JUPITER RADII  

SciTech Connect

There have been many proposed explanations for the larger-than-expected radii of some transiting hot Jupiters, including either stellar or orbital energy deposition deep in the atmosphere or deep in the interior. In this paper, we explore the important influences on hot-Jupiter radius evolution of (1) additional heat sources in the high atmosphere, the deep atmosphere, and deep in the convective interior; (2) consistent cooling of the deep interior through the planetary dayside, nightside, and poles; (3) the degree of heat redistribution to the nightside; and (4) the presence of an upper atmosphere absorber inferred to produce anomalously hot upper atmospheres and inversions in some close-in giant planets. In particular, we compare the radius expansion effects of atmospheric and deep-interior heating at the same power levels and derive the power required to achieve a given radius increase when night-side cooling is incorporated. We find that models that include consistent day/night cooling are more similar to isotropically irradiated models when there is more heat redistributed from the dayside to the nightside. In addition, we consider the efficacy of ohmic heating in the atmosphere and/or convective interior in inflating hot Jupiters. Among our conclusions are that (1) the most highly irradiated planets cannot stably have uB {approx}> 10 km s{sup -1} G over a large fraction of their daysides, where u is the zonal wind speed and B is the dipolar magnetic field strength in the atmosphere, and (2) that ohmic heating cannot in and of itself lead to a runaway in planet radius.

Spiegel, David S. [Astrophysics Department, Institute for Advanced Study, Princeton, NJ 08540 (United States); Burrows, Adam, E-mail: dave@ias.edu, E-mail: burrows@astro.princeton.edu [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544 (United States)

2013-07-20

469

Hot-carrier luminescence in Si  

Microsoft Academic Search

There has been a renewed interest in the spectra of emitted light from Si metal-oxide-semiconductor field-effect transistors (MOSFET's) in the belief that a better understanding of this phenomenon will lead to a deeper understanding of hot carriers in these devices. In this paper, we attempt to explain the physical mechanisms responsible for the light emission in Si under varying doping

Jeff Bude; Nobuyuki Sano; Akira Yoshii

1992-01-01

470

Elliptical instability in hot Jupiter systems  

NASA Astrophysics Data System (ADS)

Several studies have already considered the influence of tides on the evolution of systems composed of a star and a close-in companion to tentatively explain different observations such as the spin-up of some stars with hot Jupiters, the radius anomaly of short orbital period planets and the synchronization or quasi-synchronization of the stellar spin in some extreme cases. However, the nature of the mechanism responsible for the tidal dissipation in such systems remains uncertain. In this paper, we claim that the so-called elliptical instability may play a major role in these systems, explaining some systematic features present in the observations. This hydrodynamic instability, arising in rotating flows with elliptical streamlines, is suspected to be present in both planet and star of such systems, which are elliptically deformed by tides. The presence and the influence of the elliptical instability in gaseous bodies, such as stars or hot Jupiters, are most of the time neglected. In this paper, using numerical simulations and theoretical arguments, we consider several features associated to the elliptical instability in hot-Jupiter systems. In particular, the use of ad hoc boundary conditions makes it possible to estimate the amplitude of the elliptical instability in gaseous bodies. We also consider the influence of compressibility on the elliptical instability, and compare the results to the incompressible case. We demonstrate the ability for the elliptical instability to grow in the presence of differential rotation, with a possible synchronized latitude, provided that the tidal deformation and/or the rotation rate of the fluid are large enough. Moreover, the amplitude of the instability for a centrally-condensed mass of fluid is of the same order of magnitude as for an incompressible fluid for a given distance to the threshold of the instability. Finally, we show that the assumption of the elliptical instability being the main tidal dissipation process in eccentric inflated hot Jupiters and misaligned stars is consistent with current data.

Cébron, David; Bars, Michael Le; Gal, Patrice Le; Moutou, Claire; Leconte, Jeremy; Sauret, Alban

2013-11-01

471

Hot filament CVD of boron nitride films  

DOEpatents

Using a hot filament (.apprxeq.1400.degree. C.) to activate borazine (B.sub.3 N.sub.3 H.sub.6) molecules for subsequent reaction with a direct line-of-sight substrate, transparent boron ntiride films as thick as 25,000 angstroms are grown for a substrate temperature as low as 100.degree. C. The minimum temperature is determined by radiative heating from the adjacent hot filament. The low temperature BN films show no indication of crystallinity with X-ray diffraction (XRD). X-ray photoelectron spectra (XPS) show the films to have a B:N ratio of 0.97:1 with no other XPS detectable impurities above the 0.5% level. Both Raman and infrared (IR) spectroscopy are characteristic of h-BN with small amounts of hydrogen detected as N-H and B-H bands in the IR spectrum. An important feature of this method is the separation and localization of the thermal activation step at the hot filament from the surface reaction and film growth steps at the substrate surface. This allows both higher temperature thermal activation and lower temperature film growth.

Rye, Robert R. (Albuquerque, NM)

1992-01-01

472

Hot Stars: Old-Fashioned or Trendy?  

E-print Network

Spectroscopic analyses with the intention of the interpretation of the UV-spectra of the brightest stars as individuals - supernovae - or as components of star-forming regions - massive O stars - provide a powerful tool with great astrophysical potential for the determination of extragalactic distances and of the chemical composition of star-forming galaxies even at high redshifts. The perspectives of already initiated work with the new generation of tools for quantitative UV-spectroscopy of Hot Stars that have been developed during the last two decades are presented and the status of the continuing effort to construct corresponding models for Hot Star atmospheres is reviewed. Because the physics of the atmospheres of Hot Stars are strongly affected by velocity expansion dominating the spectra at all wavelength ranges, hydrodynamic model atmospheres for O-type stars and explosion models for Supernovae of Type Ia are necessary as basis for the synthesis and analysis of the spectra. It is shown that stellar parameters, abundances and stellar wind properties can be determined by the methods of spectral diagnostics already developed. Additionally, it will be demonstrated that models and synthetic spectra of Type Ia Supernovae of required quality are already available that make it possible to tackle the question of whether Supernovae Ia are standard candles in a cosmological sense and the SN-luminosity distances thus indicate accelerated expansion of the universe.

A. W. A. Pauldrach

2002-12-10

473

Hot air vulcanization of rubber profiles  

SciTech Connect

Elastomer profiles are deployed in quantity by the automobile industry as seals and wateproofing in coachwork. The high standards demanded by the industry; improvement in weather prediction, noise reduction, restriction of tolerances, together with powerful demand for EPDM force the rubber processing industry into development, particularly of elastomers. Complex proofing systems must also be achieved with extremely complicated profile forms. All too often such profiles have an extremely large surface together with a low cross-section density. They frequently consist of two or three rubber compounds and are steel reinforced. Sometimes they are flocked and coated with a low friction finish. Such high-tech seals require an adjustment of the vulcanization method. The consistent trend in the nineties towards lower quantities of elastomer per sealing unit and the dielectric factor, especially with EPDM, has brought an old fashioned vulcanization method once more to the fore, a method developed over the past years to an extremely high standard, namely the hot-air method. This paper describes various vulcanization and curing methods and their relative merits and disadvantages, the Gerlach hot-air concept, the hot air installation concept, and energy saving and efficiency afforded by this technique. 4 figs.

Gerlach, J.

1995-07-01

474