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Sample records for cgeh-1 coso hot

  1. Coso Hot Springs: A Condensate Fed Geothermal Feature

    NASA Astrophysics Data System (ADS)

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

    2007-12-01

    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.

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

    SciTech Connect

    Lofgren, B.E. )

    1990-05-01

    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 geothermal field in July 1987. During this period, steam was rising from numerous vents and gently boiling mud pots. Local rainfall caused increased boiling activity in several mud pots, with some overflowing during wet periods. Then in August 1988, a year after geothermal power production began major changes in hot spring activity commenced. Small mud pots and steamers started to grow and coalesce. In March 1989, mud-pot activity became more violent. Many buried wells failed causing surface activity in other areas to diminish. During ensuing months, large mud cones developed and much of the steam and boiling water occurred in a few major pots. Because the abrupt changes in hydrothermal activity followed so closely after nearby geothermal production began, the obvious cause has been attributed to geothermal developments. Studies of NWC baseline monitoring data indicate, however, that no effects of geothermal developments have been felt in the hot springs area. Rainfall and barometric effects account for most of the fluctuations in records of the past decade. Early accounts and field evidence suggest similar changes have occurred in the past.

  3. Coso Monitoring Program, January 1981 through December 1983

    NASA Astrophysics Data System (ADS)

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

    1984-09-01

    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.

  4. 75 FR 76455 - Coso Energy Developers; Coso Finance Partners; Coso Power Developers; Notice Of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-08

    ... From the Federal Register Online via the Government Printing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Coso Energy Developers; Coso Finance Partners; Coso Power Developers; Notice... Finance Partners, and Coso Power Developers, pursuant to section 207 of the Federal Energy...

  5. Coso Volcanic Field Tumulus

    USGS Multimedia Gallery

    A tumulus in the Coso Volcanic Field, California. This lava was probably more viscous than the lava found in the Hawaii tumuli. Tumuli are structures usually associated with slow-moving flows. When the top of the flow crusts over, the lava beneath can well upward and create an elliptical, domed str...

  6. Initial exploration results: COSO Geothermal Field Inyo County, California

    SciTech Connect

    Moore, J.L.; Austin, C.

    1983-09-01

    The Coso geothermal area in Inyo County, California is described. Extensive geological, geophysical, and geochemical studies of the area have been conducted making it one of the most thoroughly studied geothermal prospects in the US. The Coso geothermal system, its reservoir rocks and fractures, magmatic heat source, groundwater flow patterns, caprock or seals, and the Coso Navy Exploratory Well 75-7 are described.

  7. Geologic Study of the Coso Formation

    SciTech Connect

    D. L. Kamola; J. D. Walker

    1999-12-01

    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.

  8. The Coso Geothermal Area: A Laboratory for Advanced MEQ Studies

    E-print Network

    Foulger, G. R.

    - 1 - The Coso Geothermal Area: A Laboratory for Advanced MEQ Studies for Geothermal Monitoring-Dinger Geothermal Program Office, U. S. Navy, China Lake, CA 93555-6001 Keith.Richards-Dinge@navy.mil Keywords of three-component digital seismometers at the Coso geothermal area, California, supplemented by 14

  9. Seismicity of the Coso Range, California

    SciTech Connect

    Walter, A.W.; Weaver, C.S.

    1980-05-10

    A 16-station seismographic network, approximately 40 km north-south by 30 km east-west, was installed in the Coso Range, California, in September 1975 as part of a geological and geophysical assessment of the geothermal resource potential of range. During the first 2 years of network operations, 4216 local earthquakes (0.5< or =m< or =3.9) defined zones of seismicity that strike radially outward from a Pleistocene rhyolite field located near the center of the Coso Range. Most earthquakes were located in zones showing a general northwest trend across the range. Six earthquake swarms occurred within the area that includes the rhyolite field. Fault plane solutions show regional north-south compression: earthquakes located in northwest striking zones generally had right lateral strike slip focal mechanisms, those in northeast striking zones left lateral strike slip focal mechanisms, and those in north-south striking zones both normal and strike slip focal mechanisms. Earthquake depths showed little variation across the Coso Range; the depth distribution is similar to that of several carefully studied segments of the central San Andreas fault. The b value calculated for the entire range is 0.99 +- 0.08. The rhyolite field has a significantly higher b value of 1.26 +- 0.16; if only the shallow events (depth <5 km) are used in the calculation, the b value for this area becomes even higher, 1.34 +- 0.24. The higher b values were interpreted as reflecting the existence of short average fault lengths (<5 km) within the rhyolite field. The seismic data and other data suggest that the fault system lying between the rhyolite field and the adjacent Coso Basin is an important tectonic boundary. Present information is insufficient to determine the geothermal production capability of this fault system, but is does suggest that the system is a good target for further exploration.

  10. Microearthquake moment tensors from the Coso Geothermal area

    SciTech Connect

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

    2007-04-01

    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.

  11. The Coso EGS project - Recent developments

    USGS Publications Warehouse

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

    2004-01-01

    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.

  12. Coso geothermal environmental overview study ecosystem quality

    SciTech Connect

    Leitner, P.

    1981-09-01

    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.

  13. A gravity model for the Coso geothermal area, California

    SciTech Connect

    Feighner, M.A.; Goldstein, N.E.

    1990-08-01

    Two- and three-dimensional gravity modeling was done using gridded Bouguer gravity data covering a 45 {times} 45 km region over the Coso geothermal area in an effort to identify features related to the heat source and to seek possible evidence for an underlying magma chamber. Isostatic and terrain corrected Bouguer gravity data for about 1300 gravity stations were obtained from the US Geological Survey. After the data were checked, the gravity values were gridded at 1 km centers for the area of interest centered on the Coso volcanic field. Most of the gravity variations can be explained by two lithologic units: (1) low density wedges of Quarternary alluvium with interbedded thin basalts (2.4 g/cm{sup 3}) filling the Rose Valley and Coso Basin/Indian Wells Valley, and (2) low density cover of Tertiary volcanic rocks and intercalated Coso Formation (2.49 g/cm{sup 3}). A 3-D iterative approach was used to find the thicknesses of both units. The gravity anomaly remaining after effects from Units 1 and 2 are removed is a broad north-south-trending low whose major peak lies 5 km north of Sugarloaf Mountain, the largest of the less than 0.3 m.y. old rhyolite domes in the Coso Range. Most of this residual anomaly can be accounted for by a deep, low-density (2.47 g/cm{sup 3}) prismatic body extending from 8 to about 30 km below the surface. While some of this anomaly might be associated with fractured Sierran granitic rocks, its close correlation to a low-velocity zone with comparable geometry suggests that the residual anomaly is probably caused a large zone of partial melt underlying the rhyolite domes of the Coso Range. 12 refs., 9 figs.

  14. published in JGR, 105, 21,781-21,794, 2000 Deformation and seismicity in the Coso geothermal

    E-print Network

    Simons, Mark

    published in JGR, 105, 21,781-21,794, 2000 Deformation and seismicity in the Coso geothermal area. Interferometric synthetic aperture radar (InSAR) data collected in the Coso geothermal area, eastern California with the production area of the Coso geothermal plant. The maximum subsidence rate in the peak of the anomaly is 3

  15. 3D Magnetotelluric characterization of the COSO GeothermalField

    SciTech Connect

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

    2005-01-01

    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.

  16. Late Cenozoic volcanism, geochronology, and structure of the Coso Range, Inyo County, California

    SciTech Connect

    Duffield, W.A.; Bacon, C.R.; Dalrymple, G.B.

    1980-05-10

    The Coso Range lies at the west edge of the Great Basin, adjacent to the southern part of the Sierra Nevada. A basement complex of pre-Cenozoic plutonic and metamorphic rocks is partly buried by approx.35 km/sup 3/ of late Cenozoic volcanic rocks that were erupted during two periods, as defined by K-Ar dating: (1) 4.0--2.5 m.y., approx.31 km/sup 3/ of basalt, rhyodacite, dacite, andesite, and rhyolite, in descending order of abundance, and (2) < or =1.1 m.y., nearly equal amounts of basalt and rhyolite, most of the rhyolite being < or =0.3 m.y. old. Vents for the volcanic rocks of the younger period are localized on and near a horst of basement rocks within a concavity defined by the distribution of vents of the older period. The alignment of many vents and the presence of a considerable number of roughly north-trending normal faults of late Cenozoic age reflect basin and range tectonics dominated by roughly east-west lithospheric extension. Fumaroles, intermittently active thermal springs, and associated altered rocks occur within and immediately east of the central part of the field of Quaternary rhyolite, in an area characterized by various geophysical anomalies that are evidently related to an active hot-water geothermal system. This system apparently is heated by a reservoir of silicic magma at > or =8-km depth, itself produced and sustained through partial melting of crustal rocks by thermal energy contained in mantle-derived basaltic magma that intrudes the crust in repsonse to lithospheric extension.

  17. Volatile compositions of melt inclusions in Coso Range Rhyolite

    SciTech Connect

    Blouke, K.J. )

    1993-04-01

    Dissolved water and carbon dioxide concentrations were measured in melt inclusions in quartz phenocrysts from rhyolite domes and lava flows in the Coso volcanic field to determine pre-eruptive volatile content of the magma. Inclusions roughly 50--100 microns in diameter were analyzed for dissolved water and carbon dioxide using Fourier transform infrared spectroscopy (FTIR). The glasses have a total water concentration ranging from four to six weight percent and no detectable carbon dioxide. Vapor bubbles in the inclusions about 10--40 microns in diameter were also analyzed for their volatile composition. The spectra show no evidence for carbon dioxide, although significant water is observed. If the melt inclusions were saturated at the time of entrapment, then crystallization occurred between 1,200 and 2,100 bars pressure or greater than 4 kilometers depth.

  18. Attenuation and source properties at the Coso Geothermal area, California

    USGS Publications Warehouse

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

    1999-01-01

    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.

  19. 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 Archaeologists frequently assign artifacts to chemically discrete subsignatures of major obsidian sources. While reserved. Keywords: Obsidian fingerprinting; Intra-source variability; Coso Volcanic Field; California

  20. Time-dependent seismic tomography and its Application to the Coso geothermal area, 1996-2006

    E-print Network

    Foulger, G. R.

    Time-dependent seismic tomography and its Application to the Coso geothermal area, 1996-2006 Bruce Geothermal Program Office, U. S. Navy, China Lake, CA 93555-6001, francis.monastero@navy.mil Measurements geothermal area, California. The permanent network operated there by the US Navy, supplemented by temporary

  1. Variations in dissolved gas compositions of reservoir fluids from the Coso geothermal field

    SciTech Connect

    Williams, Alan E.; Copp, John F.

    1991-01-01

    Gas concentrations and ratios in 110 analyses of geothermal fluids from 47 wells in the Coso geothermal system illustrate the complexity of this two-phase reservoir in its natural state. Two geographically distinct regions of single-phase (liquid) reservoir are present and possess distinctive gas and liquid compositions. Relationships in soluble and insoluble gases preclude derivation of these waters from a common parent by boiling or condensation alone. These two regions may represent two limbs of fluid migration away from an area of two-phase upwelling. During migration, the upwelling fluids mix with chemically evolved waters of moderately dissimilar composition. CO{sub 2} rich fluids found in the limb in the southeastern portion of the Coso field are chemically distinct from liquids in the northern limb of the field. Steam-rich portions of the reservoir also indicate distinctive gas compositions. Steam sampled from wells in the central and southwestern Coso reservoir is unusually enriched in both H{sub 2}S and H{sub 2}. Such a large enrichment in both a soluble and insoluble gas cannot be produced by boiling of any liquid yet observed in single-phase portions of the field. In accord with an upflow-lateral mixing model for the Coso field, at least three end-member thermal fluids having distinct gas and liquid compositions appear to have interacted (through mixing, boiling and steam migration) to produce the observed natural state of the reservoir.

  2. Abstract, AGU Fall meeting, San Francisco, 10-14 December, 2007 Time-dependent Seismic Tomography of the Coso Geothermal Area, 1996-2006

    E-print Network

    Foulger, G. R.

    of the Coso Geothermal Area, 1996-2006 Gillian R. Foulger Dept. Earth Sciences, University of Durham, Durham, U.K. Bruce R. Julian U. S. Geological Survey, Menlo Park, California Francis Monastero Geothermal-epoch period. We are applying this work to data from the seismically active Coso geothermal area, California

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

    USGS Publications Warehouse

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

    1988-01-01

    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

  4. 36Cl/Cl ratios in geothermal systems: preliminary measurements from the Coso Field

    SciTech Connect

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

    1997-07-01

    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.

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

    USGS Publications Warehouse

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

    1981-01-01

    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

  6. Seismic Monitoring of EGS Tests at the Coso Geothermal Area, California, Using Accurate MEQ Locations and Full Moment Tensors

    E-print Network

    Foulger, G. R.

    Seismic Monitoring of EGS Tests at the Coso Geothermal Area, California, Using Accurate MEQ, julian@usgs.gov Francis C. Monastero Geothermal Program Office, U. S. Navy, China Lake, CA 93555 of microearthquakes occurring before, during and following Enhanced Geothermal Systems (EGS) experiments in three

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

    USGS Publications Warehouse

    Bacon, C.R.; Metz, J.

    1984-01-01

    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.

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

    SciTech Connect

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

    2006-04-01

    Local-earthquake tomographic images were calculated for each of the years 1996 - 2004 using arrival times from the U.S. Navys 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.

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

    USGS Publications Warehouse

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

    2004-01-01

    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.

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

    USGS Publications Warehouse

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

    1986-01-01

    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.

  11. Lithology and alteration mineralogy of reservoir rocks at Coso Geothermal Area, California

    SciTech Connect

    Lutz, S.J.; Moore, J.N.; Copp, J.F.

    1995-06-01

    Coso is one of several high-temperature geothermal systems associated with recent volcanic activity in the Basin and Range province. Chemical and fluid inclusion data demonstrate that production is from a narrow, asymmetric plume of thermal water that originates from a deep reservoir to the south and then flows laterally to the north. Geologic controls on the geometry of the upwelling plume were investigated using petrographic and analytical analyses of reservoir rock and vein material. The nature of the low-angle outflow zone and the overlying cap that prevents a surface expression of the geothermal system appears to be related to a combination of lithologic, structural and mineralogic factors. The position of the outflow plume is partially controlled by the distribution of fractured crystalline intrusives within foliated metamorphic rocks. Intrusive-metamorphic lithologic contacts are characterized by sericite-pyrite alteration and correlate with fluid entries in the wells. The base of a thick intrusive unit in several wells coincides with the 250{degrees}C isotherm based on fluid inclusion data. A smectite clay zone developed in the overlying metamorphic rock acts as a cap to the productive zone and inhibits vertical movement of the geothermal fluids above the main upwelling zone. The upwelling zone lies within a epidote-quartz veined, coarse-grained granite at depth in the southern portion of the field. The mineralogy of the clays varies systematically with depth and temperature. The distribution of fine-grained clay minerals with depth indicates that the smectite cap thickens dramatically from the north to the south, and overlies a strongly sericitized zone in the upwelling portion of the reservoir. Wairakite-chlorite-epidote-calcite-quartz veins at the contact with the deep granite record deposition from the hottest geothermal fluids (342{degrees}C) in the Coso field.

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

    USGS Publications Warehouse

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

    2004-01-01

    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.

  13. Chemical and isotopic characteristics of the coso east flankhydrothermal fluids: implications for the location and nature of the heatsource

    SciTech Connect

    Christenson, B.W.; Kennedy, B.M.; Adams, M.C.; Bjornstad, S.C.; Buck, C.

    2007-01-08

    Fluids have been sampled from 9 wells and 2 fumaroles fromthe East Flank of the Coso hydrothermal system with a view toidentifying, if possible, the location and characteristics of the heatsource inflows into this portion of the geothermal field. Preliminaryresults show that there has been extensive vapor loss in the system, mostprobably in response to production. Wells 38A-9, 51-16 and 83A-16 showthe highest CO2-CO-CH4-H2 chemical equilibration temperatures, rangingbetween 300-340oC, and apart from 38A-9, the values are generally inaccordance with the measured temperatures in the wells. Calculatedtemperatures for the fractionation of 13C between CO2 and CH4 are inexcess of 400oC in fluids from wells 38A-9, 64-16-RD2 and 51A-16,obviously pointing to equilibrium conditions from deeper portions of thereservoir. Given that the predominant reservoir rock lithologies in theCoso system are relatively silicic (granitic to dioritic), the isotopicsignatures appear to reflect convective circulation and equilibrationwithin rocks close to the plastic-brittle transition. 3He/4He signatures,in conjunction with relative volatile abundances in the Coso fluids,point to a possibly altered mantle source for the heat sourcefluids.

  14. Hot Tickets

    ERIC Educational Resources Information Center

    Fox, Bette-Lee; Hoffert, Barbara; Kuzyk, Raya; McCormack, Heather; Williams, Wilda

    2008-01-01

    This article describes the highlights of this year's BookExpo America (BEA) held at the Los Angeles Convention Center. The attendees at BEA had not minded that the air was recycled, the lighting was fluorescent, and the food was bad. The first hot book sighting came courtesy of Anne Rice. Michelle Moran, author of newly published novel, "The

  15. Hot Canyon

    ScienceCinema

    None

    2013-03-01

    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."

  16. Hot Canyon

    SciTech Connect

    2012-01-01

    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."

  17. 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

    USGS Publications Warehouse

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

    2009-01-01

    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. ?? The Author(s) 2009.

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

    USGS Publications Warehouse

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

    1980-01-01

    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

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

    USGS Publications Warehouse

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

    2000-01-01

    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.

  20. Origin of reverse-graded bedding in air-fall pumice, Coso Range, California

    USGS Publications Warehouse

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

    1979-01-01

    The origin of reverse grading in air-fall pyroclastic deposits has been ascribed to: (1) changing conditions at an erupting vent; (2) deposition in water; or (3) rolling of large clasts over smaller clasts on the surface of a steep slope. Structural features in a deposit of air-fall pumice lapilli in the Coso Range, California, indicate that reverse grading there formed by a fourth mechanism during flow of pumice. Reverse-graded beds in this deposit occur where pumice lapilli fell on slopes at or near the angle of repose and formed as parts of the blanket of accumulating pumice became unstable and flowed downslope. The process of size sorting during such flow is probably analogous to that which sorts sand grains in a reverse fashion during avalanching on the slip faces of sand dunes, attributed by Bagnold (1954a) to a grain-dispersive pressure acting on particles subjected to a shear stress. In view of the several ways in which air-fall pyroclastic debris may become reverse graded, caution is advised in interpretation of the origin of this structure both in modern and in ancient deposits. ?? 1979.

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

    SciTech Connect

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

    1996-01-24

    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.

  2. Distribution of quaternary rhyolite dome of the Coso Range, California: Implications for extent of the geothermal anomaly

    SciTech Connect

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

    1980-05-10

    Thirty-eight separate domes and flows of phenocryst-poor, high-silica rhyolite of similar major element chemical composition were erupted over the past 1 m.y. 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 0.3 m.y. old. The area is one of Quaternary basaltic volcanism and crustal extension. 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. The immediate source of heat for the surficial geothermal phenomena is probably a silicic magma reservoir that may still contain molten or partially molten material at a depth of at least 8 km beneath the central part of the rhyolite field. Outlying rhyolite extrusions probably reflect the presence of feeder dikes emanating from the reservoir beneath the central region. Azimuths of dikes appear to be parallel to the regional tectonic axis of maximum horizontal compression, analogous to some dike-fed flank eruptions on basaltic shields and andesitic strato-volcanoes. The areal extent of a magma reservoir and the present total heat content of the silicic magma system at Coso may be less than was previously estimated. However, the area is still considered to be one of significant geothermal potential.

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

    SciTech Connect

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

    2008-04-01

    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.

  4. Hot tub folliculitis

    MedlinePLUS

    Hot tub folliculitis is an infection of the skin around the lower part of the hair shaft (hair follicles). It occurs ... Hot tub folliculitis is caused by bacteria that survives in hot tubs, especially tubs made of wood.

  5. Hot Weather Tips

    MedlinePLUS

    HOT Weather Tips Printer-friendly version We all suffer in hot weather. However, for elderly and disabled people and ... stress and following these tips for dealing with hot weather. Wear cool clothing: See that the person ...

  6. Differentiating induced and natural seismicity using space-time-magnitude statistics applied to the Coso Geothermal field

    USGS Publications Warehouse

    Schoenball, Martin; Davatzes, Nicholas C.; Glen, Jonathan M.

    2015-01-01

    A remarkable characteristic of earthquakes is their clustering in time and space, displaying their self-similarity. It remains to be tested if natural and induced earthquakes share the same behavior. We study natural and induced earthquakes comparatively in the same tectonic setting at the Coso Geothermal Field. Covering the preproduction and coproduction periods from 1981 to 2013, we analyze interevent times, spatial dimension, and frequency-size distributions for natural and induced earthquakes. Individually, these distributions are statistically indistinguishable. Determining the distribution of nearest neighbor distances in a combined space-time-magnitude metric, lets us identify clear differences between both kinds of seismicity. Compared to natural earthquakes, induced earthquakes feature a larger population of background seismicity and nearest neighbors at large magnitude rescaled times and small magnitude rescaled distances. Local stress perturbations induced by field operations appear to be strong enough to drive local faults through several seismic cycles and reactivate them after time periods on the order of a year.

  7. Differentiating induced and natural seismicity using space-time-magnitude statistics applied to the Coso Geothermal field

    NASA Astrophysics Data System (ADS)

    Schoenball, Martin; Davatzes, Nicholas C.; Glen, Jonathan M. G.

    2015-08-01

    A remarkable characteristic of earthquakes is their clustering in time and space, displaying their self-similarity. It remains to be tested if natural and induced earthquakes share the same behavior. We study natural and induced earthquakes comparatively in the same tectonic setting at the Coso Geothermal Field. Covering the preproduction and coproduction periods from 1981 to 2013, we analyze interevent times, spatial dimension, and frequency-size distributions for natural and induced earthquakes. Individually, these distributions are statistically indistinguishable. Determining the distribution of nearest neighbor distances in a combined space-time-magnitude metric, lets us identify clear differences between both kinds of seismicity. Compared to natural earthquakes, induced earthquakes feature a larger population of background seismicity and nearest neighbors at large magnitude rescaled times and small magnitude rescaled distances. Local stress perturbations induced by field operations appear to be strong enough to drive local faults through several seismic cycles and reactivate them after time periods on the order of a year.

  8. Seismicity and deformation in the Coso Geothermal field from 2000 to 2012

    NASA Astrophysics Data System (ADS)

    Kaven, J. Ole; Hickman, Stephen H.; Davatzes, Nicholas C.

    2015-04-01

    Induced micro-seismicity in geothermal reservoirs, in particular in enhanced geothermal systems (EGS), is an intended byproduct of injection and production, as it often indicates the generation of permeability pathways on either pre-existing or newly generated faults and fractures. The hazard of inducing an earthquake large enough to cause damage to surface structures, however, is not easily avoided and has led to termination of geothermal projects. To explore the physical processes leading to damaging earthquakes, we investigate the evolution of seismicity and the factors controlling the migration, moment release rate, and structure within the seismicity in the Coso Geothermal Field (CGF). The CGF has been in production since the 1980s and includes both naturally occurring geothermal resources and portions of the reservoir that are EGS projects. We report on seismicity in the CGF that has been relocated with high precision double-difference relocation and simultaneous velocity inversion to understand the reservoir compartmentalization, in particular, where boundaries to flow exist both vertically and horizontally. We also calculate moment magnitudes (Mw) from the initial displacement pulse of the seismograms to relate moment directly to the deformation. We find that two distinct compartments form the CGF, which are divided by an aseismic gap that also shows a relatively low Vp/Vs ratio. Further, we find that events with Mw> 3.5 tend to map onto larger fault structures that are imaged by the relocated seismicity. We relate the temporal and spatial migration of moment release rate to the injection and production records in the reservoir by employing a thermo-poro-elastic finite element model in which the compartment boundaries are defined by the seismicity. We find that pore pressure effects alone are not responsible for the migration of seismicity and that poro-elastic and thermo-elastic strain changes can account for more of the observed moment release rate than pore pressure alone. These initial results indicate that coupled models of fluid flow, heat flow and solid deformation improve our understanding of the physical mechanisms that control induced seismicity in geothermal reservoirs and possibly other settings as well.

  9. 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)

    Hauksson, E.; Unruh, J.

    2007-12-01

    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.

  10. Low temperature hot corrosion

    NASA Technical Reports Server (NTRS)

    Chiang, K. T.; Pettit, F. S.; Meier, G. H.

    1983-01-01

    The reaction of Co-Cr, Ni-Cr, Co-Cr-Al, and Ni-Cr-Al alloys with Na2SO4 in the presence of SO3 at temperatures between 700 and 750 C leads to the formation of liquid CoSO4-Na2SO4 or NiSO4-Na2SO4 deposits on the alloy surface. The formation of Cr2O3 and/or Al2O3 below this deposit results in a locally low P(O2) and a higher P(S2) and P(SO2). It is noted that these conditions can prevent protective oxide formation either by sulfide formation in the alloy, which localizes the Cr and/or Al in discrete particles, or by acid fluxing involving a reaction between Al2O3 or Cr2O3 and SO2 to form a salt-soluble species and subsequent reprecipitation as porous oxides in regions of higher P(O2). These processes may occur simultaneously, although a given alloy generally exhibits features of predominantly one type. Here, the Ni-Cr and Ni-Cr-Al alloys, and to some extent the Co-Cr alloys, exhibit features indicative of the sulfidation mechanism, whereas the morphology for the Co-Cr-Al alloy is more consistent with a predominant acid fluxing mechanism.

  11. Hot Weather Tips

    MedlinePLUS

    ... FCA - A A + A You are here Home HOT Weather Tips Printer-friendly version We all suffer in hot weather. However, for elderly and disabled people and ... stress and following these tips for dealing with hot weather. Wear cool clothing: See that the person ...

  12. Modelling Hot Air Balloons.

    ERIC Educational Resources Information Center

    Brimicombe, M. W.

    1991-01-01

    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)

  13. 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)

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

    1980-01-01

    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.

  14. Julian, B.R., G.R. Foulger and F. Monastero, Microearthquake moment tensors from the Coso Geothermal area, Thirty-Second Workshop on Geothermal Reservoir Engineering, Stanford University,

    E-print Network

    Foulger, G. R.

    Geothermal area, Thirty-Second Workshop on Geothermal Reservoir Engineering, Stanford University, Stanford, California, January 22-24, 2007. Microearthquake Moment Tensors from the Coso Geothermal Area Bruce R. Julian of Durham, Durham, U. K. Francis Monastero, Geothermal Program Office, US Navy, China Lake, California

  15. Foulger, G.R., B.R. Julian and F.C. Monastero, Microearthquake characterisation of an artificially stimulated hydraulic fracture at the Coso geothermal area, California, EOS Trans. AGU, Fall Meet. Suppl., Abstract, 2006.

    E-print Network

    Foulger, G. R.

    stimulated hydraulic fracture at the Coso geothermal area, California, EOS Trans. AGU, Fall Meet. Suppl., Abstract, 2006. Microearthquake characterisation of an artificially stimulated hydraulic fracture it by injecting fluids under pressure. Instead, natural fractures were encountered at about 2,660 m depth

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

    SciTech Connect

    SGP-TR-150-16

    1995-01-26

    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.

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

    PubMed

    Chen, Huichao; Zhao, Changsui; Ren, Qiangqiang

    2012-01-01

    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

  18. 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)

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

    2006-10-01

    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.

  19. 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)

    Hauksson, Egill; Unruh, Jeffrey

    2007-06-01

    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.

  20. 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

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

    1984-01-01

    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.

  1. Hot yoga and pregnancy

    PubMed Central

    Chan, Justin; Natekar, Aniket; Koren, Gideon

    2014-01-01

    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

  2. Hot Spot at Yellowstone

    ERIC Educational Resources Information Center

    Dress, Abby

    2005-01-01

    Within this huge national park (over two million acres spread across Wyoming, Montana, and Idaho) are steaming geysers, hot springs, bubbling mudpots, and fumaroles, or steam vents. Drives on the main roads of Yellowstone take tourists through the major hot attractions, which also include Norris Geyser Basin, Upper and Lower Geyser Basin, West

  3. The Earth's Hot Spots.

    ERIC Educational Resources Information Center

    Vink, Gregory E.; And Others

    1985-01-01

    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)

  4. Menopausal hot flushes revisited.

    PubMed

    Andrikoula, M; Prelevic, G

    2009-02-01

    Vasomotor symptoms are generally recognized as one of the most common symptoms, or signs, of the menopause, together with menstrual cycle changes. The etiology of hot flushes is unknown, although several mechanisms have been implicated. The reduction in hot flushes with estrogen replacement therapy suggests a hormonal etiology. However, the levels of estrogens do not appear to correlate with hot flushes. It seems more likely that the rate of change of plasma estrogen concentrations influences the thermoregulatory system via the hypothalamus. During the past few decades, remedies for the treatment of hot flushes have advanced from simple sedatives and purgatives to the use of ovarian extracts and, finally, to pharmacological estrogen preparations. In view of the contraindications and side-effects of estrogens and progestogens in postmenopausal women, however, there is a need to consider treatments other than hormone replacement for the relief of hot flushes. PMID:19061056

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

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    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.

  6. Hot and dark matter

    E-print Network

    D'Eramo, Francesco

    2012-01-01

    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, ...

  7. Hot Springs Creek

    USGS Multimedia Gallery

    USGS scientist Jennifer Lewicki measures the discharge along a tributary to Hot Springs Creek, Akutan Island, Alaska. Steam (upper left) rises from 3 high-temperature springs that discharge into the tributary....

  8. Charmonium in Hot Medium

    E-print Network

    Zhao, Xingbo

    2012-02-14

    We investigate charmonium production in the hot medium created by heavy-ion collisions by setting up a framework in which in-medium charmonium properties are constrained by thermal lattice QCD (lQCD) and subsequently ...

  9. Beppu hot springs

    SciTech Connect

    Taguchi, Schihiro; Itoi, Ryuichi; Yusa, Yuki

    1996-05-01

    Beppu is one of the largest hot springs resorts in Japan. There are numerous fumaroles and hot springs scattered on a fan-shaped area, extending 5 km (3.1 miles) from east to west and 8 km (5.0 miles) from north to south. Some of the thermal manifestations are called {open_quotes}Jigoku (Hells){close_quotes}, and are of interest to visitors. The total amount of discharged hot springs water is estimated to be 50,000 ton/day (9,200 gpm) indicating a huge geothermal system. The biggest hotel in Beppu (Suginoi Hotel) installed a 3-MW geothermal power plant in 1981 to generate electricity for its own private use.

  10. IR Hot Wave

    SciTech Connect

    Graham, T. B.

    2010-04-01

    The IR Hot Wave{trademark} furnace is a breakthrough heat treatment system for manufacturing metal components. Near-infrared (IR) radiant energy combines with IR convective heating for heat treating. Heat treatment is an essential process in the manufacture of most components. The controlled heating and cooling of a metal or metal alloy alters its physical, mechanical, and sometimes chemical properties without changing the object's shape. The IR Hot Wave{trademark} furnace offers the simplest, quickest, most efficient, and cost-effective heat treatment option for metals and metal alloys. Compared with other heat treatment alternatives, the IR Hot Wave{trademark} system: (1) is 3 to 15 times faster; (2) is 2 to 3 times more energy efficient; (3) is 20% to 50% more cost-effective; (4) has a {+-}1 C thermal profile compared to a {+-}10 C thermal profile for conventional gas furnaces; and (5) has a 25% to 50% smaller footprint.

  11. Zen Hot Dog Molecules

    ERIC Educational Resources Information Center

    Ryan, Dennis

    2009-01-01

    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.

  12. What's Hot? What's Not?

    ERIC Educational Resources Information Center

    Buczynski, Sandy

    2006-01-01

    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

  13. Hot spring burns.

    PubMed

    Baruchin, A M

    1996-03-01

    This case report describes a woman who, while visiting a hot spring, received partial- and full-thickness immersion scald burns of both ankles and heels. The prevention of such accidents is most important; efforts should be made to educate guides and tourists about the potential hazards inherent in these resorts. PMID:8634128

  14. Hot Dog Champ Defeated

    E-print Network

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

    2007-07-25

    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...

  15. Horseshoe pitchers' hot hands.

    PubMed

    Smith, Gary

    2003-09-01

    Gilovich, Vallone, and Tversky's (1985) analysis of basketball data indicates that a player's chances of making a shot are not affected by the results of earlier shots. However, their basketball data do not control for several confounding influences. An analysis of horseshoe pitching, which does not have these defects, indicates that players do have modest hot and cold spells. PMID:14620374

  16. Hot off the Press

    ERIC Educational Resources Information Center

    Brisco, Nicole D.

    2007-01-01

    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

  17. Hot piston ring tests

    NASA Astrophysics Data System (ADS)

    Allen, David J.; Tomazic, William A.

    1987-12-01

    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.

  18. HOT GAS CLEANUP PROCESS

    EPA Science Inventory

    The report gives results of a study to identify and classify 22 hot gas cleanup (HGC) processes for desulfurizing reducing gases at above 430 C according to absorbent type into groups employing solid, molten salt, and molten metal absorbents. It describes each process in terms of...

  19. 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 ...

  20. Exercising Safely in Hot Weather

    MedlinePLUS

    ... grouchy, acting strangely, staggering, or being unresponsive l Dry, flushed skin and a strong rapid pulse or a slow weak pulse l Not sweating even if it is hot Quick Tip For more hot weather tips, see the AgePage Hyperthermia: Too Hot for ...

  1. Hot Tub Rash (Pseudomonas Dermatitis/Folliculitis)

    MedlinePLUS

    ... How Do I Protect Myself and My Family? "Hot Tub Rash" ( Pseudomonas Dermatitis / Folliculitis) Below are answers ... hot tub rash and healthy swimming. What is Hot Tub Rash? Hot tub rash, or dermatitis, is ...

  2. Hot Spring Metagenomics

    PubMed Central

    Lpez-Lpez, Olalla; Cerdn, Mara Esperanza; Gonzlez-Siso, Mara Isabel

    2013-01-01

    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 communitiestheir 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. PMID:25369743

  3. THE HOT CHOCOLATE EFFECT

    SciTech Connect

    Crawford, Frank S.

    1980-12-01

    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 ten percent accuracy of the experiments.

  4. Hot chocolate effect

    SciTech Connect

    Crawford, F.S.

    1982-05-01

    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.

  5. Hot Billet Surface Qualifier

    SciTech Connect

    Tzyy-Shuh Chang

    2007-04-30

    OG Technologies, Inc. (OGT), developed a prototype of a Hot Billet Surface Qualifier (Qualifier) based on OGTs 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.

  6. Solar Hot Water Heater

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The solar panels pictured below, mounted on a Moscow, Idaho home, are part of a domestic hot water heating system capable of providing up to 100 percent of home or small business hot water needs. Produced by Lennox Industries Inc., Marshalltown, Iowa, the panels are commercial versions of a collector co-developed by NASA. In an effort to conserve energy, NASA has installed solar collectors at a number of its own facilities and is conducting research to develop the most efficient systems. Lewis Research Center teamed with Honeywell Inc., Minneapolis, Minnesota to develop the flat plate collector shown. Key to the collector's efficiency is black chrome coating on the plate developed for use on spacecraft solar cells, the coating prevents sun heat from "reradiating," or escaping outward. The design proved the most effective heat absorber among 23 different types of collectors evaluated in a Lewis test program. The Lennox solar domestic hot water heating system has three main components: the array of collectors, a "solar module" (blue unit pictured) and a conventional water heater. A fluid-ethylene glycol and water-is circulated through the collectors to absorb solar heat. The fluid is then piped to a double-walled jacket around a water tank within the solar module.

  7. Natural or Induced: Identifying Natural and Induced Swarms from Pre-production and Co-production Microseismic Catalogs at the Coso Geothermal Field

    USGS Publications Warehouse

    Schoenball, Martin; Kaven, Joern; Glen, Jonathan M.; Davatzes, Nicholas C.

    2015-01-01

    Increased levels of seismicity coinciding with injection of reservoir fluids have prompted interest in methods to distinguish induced from natural seismicity. Discrimination between induced and natural seismicity is especially difficult in areas that have high levels of natural seismicity, such as the geothermal fields at the Salton Sea and Coso, both in California. Both areas show swarm-like sequences that could be related to natural, deep fluid migration as part of the natural hydrothermal system. Therefore, swarms often have spatio-temporal patterns that resemble fluid-induced seismicity, and might possibly share other characteristics. The Coso Geothermal Field and its surroundings is one of the most seismically active areas in California with a large proportion of its activity occurring as seismic swarms. Here we analyze clustered seismicity in and surrounding the currently produced reservoir comparatively for pre-production and co-production periods. We perform a cluster analysis, based on the inter-event distance in a space-time-energy domain to identify notable earthquake sequences. For each event j, the closest previous event i is identified and their relationship categorized. If this nearest neighbors distance is below a threshold based on the local minimum of the bimodal distribution of nearest neighbor distances, then the event j is included in the cluster as a child to this parent event i. If it is above the threshold, event j begins a new cluster. This process identifies subsets of events whose nearest neighbor distances and relative timing qualify as a cluster as well as a characterizing the parent-child relationships among events in the cluster. We apply this method to three different catalogs: (1) a two-year microseismic survey of the Coso geothermal area that was acquired before exploration drilling in the area began; (2) the HYS_catalog_2013 that contains 52,000 double-difference relocated events and covers the years 1981 to 2013; and (3) a catalog of 57,000 events with absolute locations from the local network recorded between 2002 and 2007. Using this method we identify 10 clusters of more than 20 events each in the pre-production survey and more than 200 distinct seismicity clusters that each contain at least 20 and up to more than 1000 earthquakes in the more extensive catalogs. The cluster identification method used yields a hierarchy of links between multiple generations of parent and offspring events. We analyze different topological parameters of this hierarchy to better characterize and thus differentiate natural swarms from induced clustered seismicity and also to identify aftershock sequences of notable mainshocks. We find that the branching characteristic given by the average number of child events per parent event is significantly different for clusters below than for clusters around the produced field.

  8. PREFACE: Hot Quarks 2004

    NASA Astrophysics Data System (ADS)

    Antinori, Federico; Bass, Steffen A.; Bellwied, Rene; Ullrich, Thomas; Velkovska, Julia; Wiedemann, Urs

    2005-04-01

    Why another conference devoted to ultra-relativistic heavy-ion physics? As we looked around the landscape of the existing international conferences and workshops, we realized that there was not a single one tailored to the people who are most directly involved with the actual research work: students, post-docs, and junior faculty/research scientists. Of course there are schools, but that was not what we had in mind. We wanted a meeting where young researchers could come together to discuss in depth the physics that they are working on without any hindrance. The major conferences have very limited time for discussions which is often shared amongst the most established. This leaves little room for young people to ask their questions and to get the detailed feedback which they deserve and which satisfies their curiosity. A discussion-driven workshop, centering on those without whom there will be no futurethat seemed like what was needed. And thus the Hot Quarks workshop was born. The aim of Hot Quarks was to enhance the direct exchange of scientific information among the younger members of the community, from both experiment and theory. Participation was by invitation only in order to emphasize the contributions from junior researchers. This approach makes the workshop unique among the many forums in the field. For young scientists it represented an opportunity for exposure that they would not have had in one of the major conferences. The hope is that this meeting has helped to stimulate the next generation of scientists in our field and, at the same time, strengthened their sense of community. It all came together from 18 24 July 2004, when the 77 participants met at The Inn at Snakedance in the Taos Ski Valley, New Mexico, USA, for the first Hot Quarks workshop. Photograph Participants gather in the sunshine at the foot of the Taos Ski Valley chairlift. By all accounts, Hot Quarks 2004 was a great success. Every participant had the opportunity to present her or his research and we spent an entire week talking physics and having fun from breakfast in the morning until late at night. A symbolic award was instituted for the best presentation at the workshop, dedicated to the memory of Klaus Kinder-Geiger, a sharp and brilliant young theorist who perished in the crash of Swissair Flight 111 on 2 September 1998 off the coast of Nova Scotia. It went to Denesh Molnar from Ohio State University for his outstanding talk on parton coalescence. The organizers wish to extend their gratitude to all participants for the high quality presentations making Hot Quarks 2004 a notable event. We are also very grateful for the superb hospitality of the staff of the Snakedance Inn, in particular Mitch Daniels who worked sheer miracles. Given the success of the first Hot Quarks workshop we decided to organize a second one, possibly even turning Hot Quarks into a series. The next meeting will be held in the late spring of 2006, probably in Italy. We hope it will be as memorable as the first one! Last but not least, we wish to thank all the generous sponsors of the conference: Brookhaven National Laboratory, European Organization for Nuclear Research (CERN), Gesellschaft fA~ 1/4 r Schwerionenforschung (GSI), Institute of Physics Publishing, Los Alamos National Laboratory, National Science Foundation, and Vanderbilt University. We are grateful for their support and are particularly happy that this support came from institutions both in the US and in Europe and from all the main experimental facilities that pursue a prominent heavy-ion program. Their support was essential for the success of a workshop targeting young scientists.

  9. Archaeological applications of laser-induced breakdown spectroscopy: an example from the Coso Volcanic Field, California, using advanced statistical signal processing analysis

    SciTech Connect

    Remus, Jeremiah J.; Gottfried, Jennifer L.; Harmon, Russell S.; Draucker, Anne; Baron, Dirk; Yohe, Robert

    2010-05-01

    Over the past quarter century, multielement chemical analysis has become a common means for attributing the provenance of archaeological materials. The Coso Volcanic Field (CVF) in California, USA, contains at least 38 high-silica rhyolite domes, many of which contain obsidian glass that has been quarried for tools by the indigenous population for more than 12,000 years. Artifacts made from CVF obsidian are found throughout the southwestern United States and geochemical sourcing of CVF obsidian has been an important tool in understanding prehistoric Native American trading patterns. Laser-induced breakdown spectroscopy (LIBS) is a simple atomic emission spectroscopic technique that has the potential for real-time man-portable chemical analysis in the field. Because LIBS is simultaneously sensitive to all elements, a single laser shot can be used to record the broadband emission spectra, which provides a ''chemical fingerprint'' of a material. Single-shot broadband LIBS spectra were collected using a commercial benchtop LIBS system for 27 obsidian samples from major sites across the CVF and four additional sites in California and western Nevada outside of CVF. Classification of the samples was performed using partial least-squares discriminant analysis (PLSDA), a common chemometric technique suitable for performing regression on high-dimensional data. Provenance identification for the obsidian samples was evaluated for three separate labeling frameworks. The first framework consisted of a binary classification problem to distinguish CVF samples from non-CVF samples. The second approach focused on the CVF samples with labels that corresponded to the eight separate Coso sites encompassed by the 27 samples. In the third analysis, non-CVF samples were excluded, and the remaining 27 CVF samples were labeled based on groupings defined from previous major and trace element chemical studies, which reduces the number of possible classes from eight to four. Different aspects of the classifier setup considered in this study include the training/testing routine (a 27-fold leave-one-sample-out setup versus a simple split of the data into separate sets for training and evaluation), the number of latent variables used in the regression model, and whether PLSDA operating on the entire broadband LIBS spectrum is superior to that using only a selected subset of LIBS emission lines. The results point to the robustness of the PLSDA technique and suggest that LIBS analysis combined with the appropriate statistical signal processing has the potential to be a useful tool for chemical analysis of archaeological artifacts and geological specimens.

  10. Hot oiling spreadsheet

    SciTech Connect

    Mansure, A.J.

    1996-09-01

    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.

  11. Hot air drum evaporator

    DOEpatents

    Black, Roger L. (Idaho Falls, ID)

    1981-01-01

    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.

  12. 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)

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

    2013-12-01

    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.

  13. Exploring Hot Neptune Atmospheres

    NASA Astrophysics Data System (ADS)

    Fortney, Jonathan; Marley, Mark; Saumon, Didier

    2008-03-01

    The first transiting 'hot Neptune'' GJ 436b inhabits an entirely new region of phase space for extrasolar planetary atmospheres. This relatively cool, low-mass object should be the first transiting extrasolar planet to sport a methane-rich atmosphere. Like Uranus and Neptune it may also have an atmosphere highly enriched in heavy elements. Our experience with the complex atmospheres of the known hot-Jupiters has demonstrated that insights are best gained through the combination of Spitzer observations and atmospheric modeling . However, no models have investigated the atmospheres of Neptune-class exoplanets, which may well be super metal-enriched, and span a wider range in stellar insolation and atmospheric composition than we have previously encountered. GJ 436b the coldest transiting planet, is in entirely new irradiation and mass regimes and is also the target of a barrage of planned Spitzer observations. Here we propose a new generation of atmospheric modeling to understand Spitzer observations of this new planet and others like it.

  14. Radiations from hot nuclei

    NASA Technical Reports Server (NTRS)

    Malik, F. Bary

    1993-01-01

    The investigation indicates that nuclei with excitation energy of a few hundred MeV to BeV are more likely to radiate hot nuclear clusters than neutrons. These daughter clusters could, furthermore, de-excite emitting other hot nuclei, and the chain continues until these nuclei cool off sufficiently to evaporate primarily neutrons. A few GeV excited nuclei could radiate elementary particles preferentially over neutrons. Impact of space radiation with materials (for example, spacecraft) produces highly excited nuclei which cool down emitting electromagnetic and particle radiations. At a few MeV excitation energy, neutron emission becomes more dominant than gamma-ray emission and one often attributes the cooling to take place by successive neutron decay. However, a recent experiment studying the cooling process of 396 MeV excited Hg-190 casts some doubt on this thinking, and the purpose of this investigation is to explore the possibility of other types of nuclear emission which might out-compete with neutron evaporation.

  15. Hot, Dry and Cloudy

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [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.

  16. TRUEX hot demonstration

    SciTech Connect

    Chamberlain, D.B.; Leonard, R.A.; Hoh, J.C.; Gay, E.C.; Kalina, D.G.; Vandegrift, G.F.

    1990-04-01

    In FY 1987, a program was initiated to demonstrate technology for recovering transuranic (TRU) elements from defense wastes. This hot demonstration was to be carried out with solution from the dissolution of irradiated fuels. This recovery would be accomplished with both PUREX and TRUEX solvent extraction processes. Work planned for this program included preparation of a shielded-cell facility for the receipt and storage of spent fuel from commercial power reactors, dissolution of this fuel, operation of a PUREX process to produce specific feeds for the TRUEX process, operation of a TRUEX process to remove residual actinide elements from PUREX process raffinates, and processing and disposal of waste and product streams. This report documents the work completed in planning and starting up this program. It is meant to serve as a guide for anyone planning similar demonstrations of TRUEX or other solvent extraction processing in a shielded-cell facility.

  17. Spectral Modeling Hot Star Winds

    E-print Network

    Cohen, David

    Spectral Modeling of X-Rays from Hot Star Winds Emma Wollman Advisor: David Cohen #12;Hot Stars Short-livedShort-lived (~ 1-10 million yrs)(~ 1-10 million yrs) #12;Stellar Winds Net momentum More luminosity !"stronger wind Mass-loss rate determines the fate of the star #12;X-ray Production

  18. 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...

  19. Hot hollow cathode gun assembly

    DOEpatents

    Zeren, J.D.

    1983-11-22

    A hot hollow cathode deposition gun assembly includes a hollow body having a cylindrical outer surface and an end plate for holding an adjustable heat sink, the hot hollow cathode gun, two magnets for steering the plasma from the gun into a crucible on the heat sink, and a shutter for selectively covering and uncovering the crucible.

  20. Hot cells and Sample Preparation

    E-print Network

    Hot cells and Sample Preparation Steven Van Boxel #12;MRF building layout 32m #12;MRF building layout 32m Hot cells for receipt and processing using MSMs Shielded rooms for scientific equipment cells Designed and built by Aquila Currently being installed in MRF building Modular design, 4

  1. Hot hollow cathode gun assembly

    NASA Astrophysics Data System (ADS)

    Zeren, J. D.

    1983-11-01

    A hot hollow cathode deposition gun assembly is disclosed. The device includes a hollow body having a cylindrical outer surface and an end plate for holding an adjustable heat sink, the hot hollow cathode gun, two magnets for steering the plasma from the gun into a crucible on the heat sink, and a shutter for selectively covering and uncovering the crucible.

  2. OT2_rvisser_2: Hot water in hot cores

    NASA Astrophysics Data System (ADS)

    Visser, R.

    2011-09-01

    As matter flows from the ice-cold envelope onto a forming protostar, it heats up from temperatures of 10 K to more than 100 K. The region where the temperature exceeds 100 K (the hot core or hot corino) is where the molecular envelope connects with both the seedling circumstellar disk and the bipolar outflow. As the envelope contracts from larger scales, a lot of material passes through the hot core before accreting onto the disk. The hot core is therefore a crucial step in establishing the physical and chemical properties of planetary building blocks. However, little is yet known about hot cores. How large and how massive are they? How hot are they? Are they exposed to strong UV or X-ray fluxes? We propose the rotationally excited 3(12)-3(03) line of H2-18O at 1095.6 GHz (E_up = 249 K) as a novel probe into the properties of hot cores. This line was detected as a narrow emission feature (FWHM ~4 km/s) in a deep integration (5 hr) in the Class 0 protostar NGC1333 IRAS2A. Comparing the line intensity to radiative transfer models, we find a tentative H2-16O hot core abundance of 4x10^-6. This is a factor of 50 lower than one would expect from simple evaporation of water ice above 100 K. Why is the hot core of IRAS2A so much "drier" than expected? Is most of the water destroyed by UV photons and/or X-rays? We propose to measure the water abundance in the hot cores of a sample of five additional Class 0 and I protostars by obtaining deep integrations of the 3(12)-3(03) lines of H2-16O and H2-18O. This mini-survey will reveal whether NGC1333 IRAS2A is unique in having a "dry" hot core, or whether "dry" hot cores are a common feature of low-mass embedded protostars. If they are a common feature, it means they are a more hostile environment than previously thought, with high fluxes of destructive UV photons and X-rays.

  3. Slip and Dilation Tendency Anlysis of Neal Hot Springs Geothermal Area

    DOE Data Explorer

    Faulds, James E.

    2013-12-31

    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...

  4. Hot Stars With Hot Jupiters Have High Obliquities

    E-print Network

    Winn, Joshua Nathan

    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, ...

  5. Hot melt adhesive attachment pad

    NASA Technical Reports Server (NTRS)

    Fox, R. L.; Frizzill, A. W.; Little, B. D.; Progar, D. J.; Coultrip, R. H.; Couch, R. H.; Gleason, J. R.; Stein, B. A.; Buckley, J. D.; St.clair, T. L. (inventors)

    1984-01-01

    A hot melt adhesive attachment pad for releasably securing distinct elements together is described which is particularly useful in the construction industry or a spatial vacuum environment. The attachment pad consists primarily of a cloth selectively impregnated with a charge of hot melt adhesive, a thermo-foil heater, and a thermo-cooler. These components are securely mounted in a mounting assembly. In operation, the operator activates the heating cycle transforming the hot melt adhesive to a substantially liquid state, positions the pad against the attachment surface, and activates the cooling cycle solidifying the adhesive and forming a strong, releasable bond.

  6. Theoretical Modelling of Hot Stars

    NASA Astrophysics Data System (ADS)

    Najarro, F.; Hillier, D. J.; Figer, D. F.; Geballe, T. R.

    1999-06-01

    Recent progress towards model atmospheres for hot stars is discussed. A new generation of NLTE wind blanketed models, together with high S/N spectra of the hot star population in the central parsec, which are currently being obtained, will allow metal abundance determinations (Fe, Si, Mg, Na, etc). Metallicity studies of hot stars in the IR will provide major constraints not only on the theory of evolution of massive stars but also on our efforts to solve the puzzle of the central parsecs of the Galaxy. Preliminary results suggest that the metallicity of the Pistol Star is 3 times solar, thus indicating strong chemical enrichment of the gas in the Galactic Center.

  7. Hot Hydrogen Test Facility

    SciTech Connect

    Swank, W. David; Carmack, Jon; Werner, James E.; Pink, Robert J.; Haggard, DeLon C.; Johnson, Ryan

    2007-01-30

    The core in a nuclear thermal rocket will operate at high temperatures and in hydrogen. One of the important parameters in evaluating the performance of a nuclear thermal rocket is specific impulse, ISP. This quantity is proportional to the square root of the propellant's absolute temperature and inversely proportional to square root of its molecular weight. Therefore, high temperature hydrogen is a favored propellant of nuclear thermal rocket designers. Previous work has shown that one of the life-limiting phenomena for thermal rocket nuclear cores is mass loss of fuel to flowing hydrogen at high temperatures. The hot hydrogen test facility located at the Idaho National Lab (INL) is designed to test suitability of different core materials in 2500 deg. C hydrogen flowing at 1500 liters per minute. The facility is intended to test low activity uranium containing materials but is also suited for testing cladding and coating materials. In this first installment the facility is described. Automated data acquisition, flow and temperature control, vessel compatibility with various core geometries and overall capabilities are discussed.

  8. Hot Hydrogen Test Facility

    SciTech Connect

    W. David Swank

    2007-02-01

    The core in a nuclear thermal rocket will operate at high temperatures and in hydrogen. One of the important parameters in evaluating the performance of a nuclear thermal rocket is specific impulse, ISp. This quantity is proportional to the square root of the propellants absolute temperature and inversely proportional to square root of its molecular weight. Therefore, high temperature hydrogen is a favored propellant of nuclear thermal rocket designers. Previous work has shown that one of the life-limiting phenomena for thermal rocket nuclear cores is mass loss of fuel to flowing hydrogen at high temperatures. The hot hydrogen test facility located at the Idaho National Lab (INL) is designed to test suitability of different core materials in 2500C hydrogen flowing at 1500 liters per minute. The facility is intended to test non-uranium containing materials and therefore is particularly suited for testing potential cladding and coating materials. In this first installment the facility is described. Automated Data acquisition, flow and temperature control, vessel compatibility with various core geometries and overall capabilities are discussed.

  9. Neptune's 'Hot' South Pole

    NASA Technical Reports Server (NTRS)

    2007-01-01

    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.

  10. Really Hot Stars

    NASA Astrophysics Data System (ADS)

    2003-04-01

    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 Lige (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

  11. Solutions for Hot Situations

    NASA Technical Reports Server (NTRS)

    2003-01-01

    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.

  12. Not so hot "hot spots" in the oceanic mantle.

    PubMed

    Bonath, E

    1990-10-01

    Excess volcanism and crustal swelling associated with hot spots are generally attributed to thermal plumes upwelling from the mantle. This concept has been tested in the portion of the Mid-Atlantic Ridge between 34 degrees and 45 degrees (Azores hot spot). Peridotite and basalt data indicate that the upper mantle in the hot spot has undergone a high degree of melting relative to the mantle elsewhere in the North Atlantic. However, application of various geothermometers suggests that the temperature of equilibration of peridotites in the mantle was lower, or at least not higher, in the hot spot than elsewhere. The presence of H(2)O-rich metasomatized mantle domains, inferred from peridotite and basalt data, would lower the melting temperature of the hot spot mantle and thereby reconcile its high degree ofmelting with the lack of a mantle temperature anomaly. Thus, some so-called hot spots might be melting anomalies unrelated to abnormally high mantle temperature or thermal plumes. PMID:17808242

  13. Do scientists trace hot topics?

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

    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.

  14. Hot carrier diffusion in graphene

    E-print Network

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

    2010-11-01

    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. ...

  15. Do scientists trace hot topics?

    PubMed Central

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

    2013-01-01

    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

  16. Hot Dark Matter in Cosmology

    E-print Network

    Joel R. Primack; Michael A. K. Gross

    2000-07-12

    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_\

  17. Is Tibetan Crust Hot?

    NASA Astrophysics Data System (ADS)

    Wang, C.; Chen, W.

    2011-12-01

    Strong impedance contrasts, detected by seismic reflection profiles, have been interpreted as evidence for aqueous fluids or even partial melts below a depth of about 20 km in southern Tibet, suggesting unusually high temperatures in the crust which reaches a thickness of up to 75 km in places. A collection of recent, complementary seismic observations reveal that the northern edge of underthrust Indian mantle lithosphere ("Greater India") has advanced, en masse, beneath Tibet sub-horizontally some 600 km northward from the Himalayan collision front. This configuration of overlapping lithosphere, however, calls for a low geotherm in much of the lower Tibetan crust, because the progressive advance of the Archean (therefore cold) mantle keel provides an effective heat sink that cools the crust above. Here we present a thermal model for the Tibetan lithosphere that is consistent with the current tectonic configuration. In essence, the Tibetan crust is cooled from below by a horizontally advancing Greater India as the entire package of overlapping lithosphere adjusts itself thermally toward a new equilibrium state. Cooling is most pronounced in the first 10 My of collision; after 30 My, temperature in the lower crust and the uppermost mantle has become low. Even so, including in our model effects of deep circulation of groundwater along steeply inclined extensional fault zones can account for the common occurrence of hot springs in rift valleys of southern Tibet. Together with empirical results on the temperature of brittle-ductile transitions in crustal and mantle rocks, temperature profile in our model can also explain the bimodal distribution of seismicity beneath southern Tibet, i.e., pronounced seismicity in the upper crust down to depths of 15 to 20 km, general absence of seismicity from 20 to 80 km, and reappearance of seismicity in the uppermost mantle at about 80 to 100 km.

  18. Review of hot flash diaries

    PubMed Central

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

    2012-01-01

    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-hour 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 & 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 & 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 & EMEA in support of drug approval. Either diary is acceptable for use in clinical trials. PMID:22230663

  19. 29 CFR 1915.14 - Hot work.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Hot work. 1915.14 Section 1915.14 Labor Regulations... Dangerous Atmospheres in Shipyard Employment 1915.14 Hot work. (a) Hot work requiring testing by a Marine Chemist or Coast Guard authorized person. (1) The employer shall ensure that hot work is not performed...

  20. 29 CFR 1915.14 - Hot work.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Hot work. 1915.14 Section 1915.14 Labor Regulations... Dangerous Atmospheres in Shipyard Employment 1915.14 Hot work. (a) Hot work requiring testing by a Marine Chemist or Coast Guard authorized person. (1) The employer shall ensure that hot work is not performed...

  1. 29 CFR 1915.14 - Hot work.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Hot work. 1915.14 Section 1915.14 Labor Regulations... Dangerous Atmospheres in Shipyard Employment 1915.14 Hot work. (a) Hot work requiring testing by a Marine Chemist or Coast Guard authorized person. (1) The employer shall ensure that hot work is not performed...

  2. 29 CFR 1915.14 - Hot work.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Hot work. 1915.14 Section 1915.14 Labor Regulations... Dangerous Atmospheres in Shipyard Employment 1915.14 Hot work. (a) Hot work requiring testing by a Marine Chemist or Coast Guard authorized person. (1) The employer shall ensure that hot work is not performed...

  3. 29 CFR 1915.14 - Hot work.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Hot work. 1915.14 Section 1915.14 Labor Regulations... Dangerous Atmospheres in Shipyard Employment 1915.14 Hot work. (a) Hot work requiring testing by a Marine Chemist or Coast Guard authorized person. (1) The employer shall ensure that hot work is not performed...

  4. Hot Deformation Behavior of Incoloy 901 Through Hot Tensile Testing

    NASA Astrophysics Data System (ADS)

    Mohammadi Shore, F.; Morakabati, M.; Abbasi, S. M.; Momeni, A.

    2014-04-01

    Hot deformation tests were conducted on cast and wrought Incoloy 901 produced by electro-slag remelting at temperatures of 950-1150 C and strain rates of 0.01-1 s-1. Both materials showed acceptable hot workability in the studied range of temperature and strain rates. However, better workability of the wrought material was associated with easier dynamic recrystallization compared to in the cast material. A complete dynamic recrystallization in the wrought material was observed at temperatures above 1100 C. On the other hand, in the cast material that was characterized by a coarse grain structure, dynamic recrystallization occurred partially and was attributed to the low density of grain boundaries. It was recognized that in order to avoid the risk of premature fracture, hot processing of the studied material should be conducted in the temperature range of 1000-1100 C. At high temperatures, over 1100 C, both materials suffered from a lack of acceptable hot workability. Rather, the wrought material showed a slight hot ductility trough around 1050 C that could be attributed to the segregation of detrimental solute atoms such as S and P to the grain boundaries. The grain boundary decohesion was controlling the fracture mechanism of the wrought material. Due to the absence of extensive DRX in the cast material, the incipient melting, void formation, and decohesion of precipitates were found responsible for the final fracture.

  5. Hot conditioning equipment conceptual design report

    SciTech Connect

    Bradshaw, F.W., Westinghouse Hanford

    1996-08-06

    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.

  6. Promethus Hot Leg Piping Concept

    SciTech Connect

    AM Girbik; PA Dilorenzo

    2006-01-24

    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.

  7. Prometheus Hot Leg Piping Concept

    SciTech Connect

    Gribik, Anastasia M.; DiLorenzo, Peter A.

    2007-01-30

    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.

  8. Menopausal hot flashes: Randomness or rhythmicity

    NASA Astrophysics Data System (ADS)

    Kronenberg, Fredi

    1991-10-01

    Menopausal hot flashes are episodes of flushing, increased heart rate, skin blood flow and skin temperature, and a sensation of heat. The thermoregulatory and cardiovascular concomitants of hot flashes are associated with peaks in the levels of various hormones and neurotransmitters in the peripheral circulation. Although hot flashes affect about 75% of women, and are the primary reason that women at menopause seek medical attention, the mechanism of hot flashes is still not understood. Hot flashes vary in frequency and intensity both within and between individuals, and have been thought of as occurring randomly. Yet, some women report that their hot flashes are worse at a particular time of day or year. Initial examination of subjects' recordings of their hot flashes showed diurnal patterns of hot flash occurrence. There also seems to be a diurnal rhythm of hot flash intensity. Continuous physiological monitoring of hot flashes is facilitating the analysis of these patterns, which is revealing circadian and ultradian periodicities. The occurrence of hot flashes can be modulated by external and internal factors, including ambient temperature and fever. Rhythms of thermoregulatory and endocrine functions also may influence hot flash patterns. Examination of the interrelationships between the various systems of the body involved in hot flashes, and a multidisciplinary approach to the analysis of hot flash patterns, will aid our understanding of this complex phenomenon.

  9. Swift, UVOT and Hot Stars

    E-print Network

    Siegel, Michael H; Hagen, Lea M Z; Hoversten, Erik A

    2015-01-01

    We present the results of our ongoing investigation into the properties of hot stars and young stellar populations using the Swift/UVOT telescope. We present UVOT photometry of open and globular clusters and show that UVOT is capable of characterizing a variety of rare hot stars, including Post-Asymptotic Giant Branch and Extreme Horizontal Branch Stars. We also present very early reults of our survey of stellar populations in the Small Magellanic Cloud. We find that the SMC has experienced recent bouts of star formation but constraining the exact star formation history will depend on finding an effective model of the reddening within the SMC.

  10. Hot Gas Halos in Galaxies

    SciTech Connect

    Mulchaey, John S.; Jeltema, Tesla E.

    2010-06-08

    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.

  11. Dust extraction from hot gases

    SciTech Connect

    Rennhack, R.

    1982-07-01

    The introduction of new energy-saving and low-pollution technologies requires development of highly efficient systems for purifying dust-laden hot gases at temperatures between 400 and 1000/sup 0/C and pressures between 1 and 20 bar. The present state of dust removal is described for separators utilizing mechanical forces, electrical effects, filtration, and wet techniques. Typical applications of present-day dust extraction from hot gases are presented. Possible developments with a view to extending the scope of dust extraction are indicated.

  12. Hot electron cooling in graphite: Supercollision versus hot phonon decay

    NASA Astrophysics Data System (ADS)

    Stange, A.; Sohrt, C.; Yang, L. X.; Rohde, G.; Janssen, K.; Hein, P.; Oloff, L.-P.; Hanff, K.; Rossnagel, K.; Bauer, M.

    2015-11-01

    Disorder-assisted electron-phonon scattering processes (supercollision processes) have been reported to dominate the cooling of hot carriers in graphene. Here, we determine to what extent this type of relaxation mechanism governs the hot carrier dynamics in the parent compound graphite. Electron temperature transients derived from time- and angle-resolved extreme ultraviolet photoemission spectra are analyzed based on a three-temperature model which considers electron gas, optical phonons, and acoustic phonons as coupled subsystems. In the probed fluence regime of 0.035 -1.4 mJ /cm2 , we find no indications for supercollision processes being involved in the cooling of the hot carriers. The data are, by contrast, compatible with a hot phonon assisted mechanism involving anharmonic coupling between optical phonons and acoustic phonons, a process which has previously been suggested for graphite. We attribute the striking difference to the reported findings for (substrate-supported) graphene to the low defect density of highly ordered pyrolitic graphite.

  13. Treatment of hot tar burns

    PubMed Central

    Bose, B.; Tredget, T.

    1982-01-01

    Hot tar burns, although rare, usually occur in workers in the paving and roofing industries. When tar is heated to high temperatures it can cause deep burns, and its removal often causes further damage. However, the use of one of the polysorbates (surface-active agents) makes removal easy and painless. ImagesFIG. 1 PMID:7083105

  14. Origins of Hot Jupiters, Revisited

    NASA Astrophysics Data System (ADS)

    Batygin, Konstantin; Bodenheimer, Peter; Laughlin, Greg

    2015-12-01

    Hot Jupiters, giant extrasolar planets with orbital periods less than ~10 days, have long been thought to form at large radial distances (a > 2AU) in protostellar disks, only to subsequently experience large-scale inward migration to the small orbital radii at which they are observed. Here, we propose that a substantial fraction of the hot Jupiter population forms in situ, with the Galactically prevalent short-period super-Earths acting as the source population. Our calculations suggest that under conditions appropriate to the inner regions of protostellar disks, rapid gas accretion can be initiated for solid cores of 10-20 Earth masses, in line with the conventional picture of core-nucleated accretion. This formation scenario leads to testable consequences, including the expectation that hot Jupiters should frequently be accompanied by additional planets, reminiscent of those observed in large numbers by NASAs Kepler Mission and Doppler velocity surveys. However, dynamical interactions during the early stages of planetary systems' evolutionary lifetimes tend to increase the mutual inclinations of exterior, low-mass companions to hot Jupiters, making transits rare. High-precision radial velocity monitoring provides the best prospect for their detection.

  15. Solar Hot Water Hourly Simulation

    Energy Science and Technology Software Center (ESTSC)

    2009-12-31

    The Software consists of a spreadsheet written in Microsoft Excel which provides an hourly simulation of a solar hot water heating system (including solar geometry, solar collector efficiency as a function of temperature, energy balance on storage tank and lifecycle cost analysis).

  16. Hot, Cold, and Really Cold.

    ERIC Educational Resources Information Center

    Leyden, Michael

    1997-01-01

    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

  17. Improving the surgical hot clinic

    PubMed Central

    Hubbard, Thomas; Thomas, Rhys

    2014-01-01

    Ambulatory care is an underdeveloped concept in the setting of emergency surgery, however it is recognised that many institutions will need to develop this service to cope with increased time and financial pressures.[1] There is increased emphasis on ambulatory care pathways for a variety of medical conditions.[2] Risk management is important in managing patients with acute abdominal pain in an outpatient setting and senior doctor support is essential. While the patient remains in the community, effective communication with the patient's primary care provider improves patient safety and satisfaction.[3] This quality improvement project identified current service provision of ambulatory care for surgical patients in the hot clinic at Croydon University Hospital with subsequent consultation with the surgical department to identify problems arising from the throughput of patients. Guidelines were then updated incorporating solutions to the identified issues which were then validated by the department of general surgery. Post intervention measurement identified a decrease in patients whose principal assessment and management was made by a senior house officer level doctor through the hot clinic patient journey from 26% to 9% (64% decrease), indicating an increase in registrar and/or consultant involvement in managing the hot clinic. The number of patients attending hot clinic that had effective discharge liaison (in the form of a formal letter) to the GP increased from 18% to 68% (250% increase). In conclusion, the introduction of updated guidelines effected a safer and more effective ambulatory hot clinic to perform closer to full capacity, providing improved patient care for the local population.

  18. Hot outflows in galaxy clusters

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, C. C.; McNamara, B. R.

    2015-10-01

    The gas-phase metallicity distribution has been analysed for the hot atmospheres of 29 galaxy clusters using Chandra X-ray Observatory observations. All host brightest cluster galaxies (BCGs) with X-ray cavity systems produced by radio AGN. We find high elemental abundances projected preferentially along the cavities of 16 clusters. The metal-rich plasma was apparently lifted out of the BCGs with the rising X-ray cavities (bubbles) to altitudes between twenty and several hundred kiloparsecs. A relationship between the maximum projected altitude of the uplifted gas (the `iron radius') and jet power is found with the form R_Fe ? P_jet^{0.45}. The estimated outflow rates are typically tens of solar masses per year but exceed 100 M? yr- 1 in the most powerful AGN. The outflow rates are 10-20 per cent of the cooling rates, and thus alone are unable to offset a cooling inflow. Nevertheless, hot outflows effectively redistribute the cooling gas and may play a significant role at regulating star formation and AGN activity in BCGs and presumably in giant elliptical galaxies. The metallicity distribution overall can be complex, perhaps due to metal-rich gas returning in circulation flows or being blown around in the hot atmospheres. Roughly 15 per cent of the work done by the cavities is expended lifting the metal-enriched gas, implying their nuclear black holes have increased in mass by at least 107-109 M?. Finally, we show that hot outflows can account for the broad, gas-phase metallicity distribution compared to the stellar light profiles of BCGs, and we consider a possible connection between hot outflows and cold molecular gas flows discovered in recent Atacama Large Millimeter Array observations.

  19. Hyperthermia: Too Hot for Your Health

    MedlinePLUS

    ... Stay Connected You are here Home Hyperthermia: too hot for your health NIH provides heat-related illness ... Calvin | (301) 496-1752 | nianews3@mail.nih.gov Hot summer weather can pose special health risks to ...

  20. Hot Flashes amd Night Sweats (PDQ)

    MedlinePLUS

    ... Professionals Questions to Ask about Your Treatment Research Hot Flashes and Night Sweats (PDQ) Overview Key Points ... quality of life in many patients with cancer. Hot flashes and night sweats may be side effects ...

  1. HOT Lane Policies and Their Implications

    E-print Network

    Goel, Rahul

    2011-08-08

    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...

  2. FRW Universe The Hot Big Bang

    E-print Network

    Weijgaert, Rien van de

    FRW Universe & The Hot Big Bang: #12;Adiabatic Expansion From the Friedmann equations is the essence behind what we commonly denote as Hot Big Bang From this evolution of temperature we can thus reconstruct the detailed Cosmic Thermal History #12;The Universe: the Hot Big Bang Timeline: the Cosmic

  3. Slip and Dilation Tendency Anlysis of Neal Hot Springs Geothermal Area

    SciTech Connect

    Faulds, James E.

    2013-12-31

    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...

  4. Noise Generation in Hot Jets

    NASA Technical Reports Server (NTRS)

    Khavaran, Abbas; Kenzakowski, Donald C.

    2007-01-01

    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.

  5. Atmospheric Escape from Hot Jupiters

    E-print Network

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

    2004-03-16

    The extra-solar planet HD209458b 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 HD209458b is in excellent agreement with the HI Lyman-alpha observations. We find that the tidal forces and high temperatures in the upper atmosphere must be taken into account to obtain reliable estimate of the atmospheric escape. Because of the tidal forces, we show that there is a new escape mechanism at intermediate temperatures at which the exobase reaches the Roche lobe. From an energy balance, we can estimate plausible values for the planetary exospheric temperatures, and thus obtain typical life times of planets as a function of their mass and orbital distance.

  6. Hot atom chemistry and radiopharmaceuticals

    SciTech Connect

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

    2012-12-19

    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.

  7. HOT HYDROGEN IN DIFFUSE CLOUDS

    SciTech Connect

    Cecchi-Pestellini, Cesare; Duley, Walt W.; Williams, David A. E-mail: wwduley@uwaterloo.ca

    2012-08-20

    Laboratory evidence suggests that recombination of adsorbed radicals may cause an abrupt temperature excursion of a dust grain to about 1000 K. One consequence of this is the rapid desorption of adsorbed H{sub 2} molecules with excitation temperatures of this magnitude. We compute the consequences of injection of hot H{sub 2} into cold diffuse interstellar gas at a rate of 1% of the canonical H{sub 2} formation rate. We find that the level populations of H{sub 2} in J = 3, 4, and 5 are close to observed values, and that the abundances of CH{sup +} and OH formed in reactions with hot hydrogen are close to the values obtained from observations of diffuse clouds.

  8. Spectropolarimetry of hot, luminous stars

    NASA Technical Reports Server (NTRS)

    Schulte-Ladbeck, Regina E.

    1994-01-01

    I review polarimetric observations of presumably single, hot luminous stars. The stellar types discussed are OB stars. B(e) supergiants, Luminous Blue Variables (LBV), Wolf-Rayet (W-R) stars, and type II supernovae (SN). It is shown that variable, intrinsic polarization is a common phenomenon in that part of the Hertzsprung-Russell (HR) diagram which these stars occupy. However, much observational work remains to be done before we can answer the most basic, statistical questions about the polarimetric properties of different groups of hot, luminous stars. Insight into the diagnostic power of polarization observations has been gained, but cannot be exploited without detailed models. Thus, while polarimetric observations do tell us that the mass-loss processes of all types of massive stars are time-dependent and anisotropic, the significance that this might have for the accuracy of their stellar parameters and evolutionary paths remains elusive.

  9. Hot isostatic pressing of ceramics

    NASA Technical Reports Server (NTRS)

    Honma, K.

    1985-01-01

    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.

  10. Hot gas engine heater head

    DOEpatents

    Berntell, John O. (Staffanstorp, SE)

    1983-01-01

    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.

  11. Coping with Hot Work Environments

    E-print Network

    Smith, David

    2005-04-28

    workers avoid this condition. Momentary or transient heat fatigue is marked by discomfort and mental strain because of prolonged exposure to heat. Workers can lose coordination and alertness and/or become irritable and depressed. Unacclimated workers... ? Providing air-conditioned rooms, enclosures or vehicles as work areas Special Considerations During Prolonged Heat Heat illnesses usually increase when hot weather lasts more than 3 days. Workers are placed at higher risk after progressive loss of body...

  12. ADVANCED HOT GAS FILTER DEVELOPMENT

    SciTech Connect

    E.S. Connolly; G.D. Forsythe

    1998-12-22

    Advanced, coal-based power plants will require durable and reliable hot gas filtration systems to remove particulate contaminants from the gas streams to protect downstream components such as turbine blades from erosion damage. It is expected that the filter elements in these systems will have to be made of ceramic materials to withstand goal service temperatures of 1600 F or higher. Recent demonstration projects and pilot plant tests have indicated that the current generation of ceramic hot gas filters (cross-flow and candle configurations) are failing prematurely. Two of the most promising materials that have been extensively evaluated are clay-bonded silicon carbide and alumina-mullite porous monoliths. These candidates, however, have been found to suffer progressive thermal shock fatigue damage, as a result of rapid cooling/heating cycles. Such temperature changes occur when the hot filters are back-pulsed with cooler gas to clean them, or in process upset conditions, where even larger gas temperature changes may occur quickly and unpredictably. In addition, the clay-bonded silicon carbide materials are susceptible to chemical attack of the glassy binder phase that holds the SiC particles together, resulting in softening, strength loss, creep, and eventual failure.

  13. Hot Accretion With Saturated Conduction

    E-print Network

    Kristen Menou

    2005-07-08

    Observations of the hot gas surrounding Sgr A* and a few other nearby galactic nuclei imply electron and proton mean free paths comparable to the gas capture radius: hot accretion likely proceeds under weakly-collisional conditions in these systems. As a result, thermal conduction, rather than convection, may be important on all scales and affect the global flow properties. The self-similar ADAF solution of Narayan & Yi (1994) is generalized to include a saturated form of thermal conduction, as is appropriate for the weakly-collisional regime of interest. Conduction provides extra heating and yet it reduces the free-free radiative efficiency of the accretion flow (by potentially large factors). These idealized solutions suggest that thermal conduction may be an important physical ingredient to understand hot accretion onto dim accreting black holes. Conduction could also play a role in reducing the rate at which black holes capture ambient gas and in providing an evaporation mechanism for an underlying cold thin disk.

  14. Cool Stars in Hot Places

    E-print Network

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

    2007-04-08

    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.

  15. ESA uncovers Geminga's `hot spot'

    NASA Astrophysics Data System (ADS)

    2004-07-01

    16 July 2004 Astronomers using ESAs X-ray observatory XMM-Newton have detected a small, bright hot spot on the surface of the neutron star called Geminga, 500 light-years away. The hot spot is the size of a football field and is caused by the same mechanism producing Gemingas X-ray tails. This discovery identifies the missing link between the X-ray and gamma-ray emission from Geminga. hi-res Size hi-res: 1284 kb Credits: ESA, P. Caraveo (IASF, Milan) Geminga's hot spot This figure shows the effects of charged particles accelerated in the magnetosphere of Geminga. Panel (a) shows an image taken with the EPIC instrument on board the XMM-Newton observatory. The bright tails, made of particles kicked out by Gemingas strong magnetic field, trail the neutron star as it moves about in space. Panel (b) shows how electrically charged particles interact with Gemingas magnetic field. For example, if electrons (blue) are kicked out by the star, positrons (in red) hit the stars magnetic poles like in an own goal. Panel (c) illustrates the size of Gemingas magnetic field (blue) compared to that of the star itself at the centre (purple). The magnetic field is tilted with respect to Gemingas rotation axis (red). Panel (d) shows the magnetic poles of Geminga, where charged particles hit the surface of the star, creating a two-million degrees hot spot, a region much hotter than the surroundings. As the star spins on its rotation axis, the hot spot comes into view and then disappears, causing the periodic colour change seen by XMM-Newton. An animated version of the entire sequence can be found at: Click here for animated GIF [low resolution, animated GIF, 5536 KB] Click here for AVI [high resolution, AVI with DIVX compression, 19128 KB] hi-res Size hi-res: 371 kb Credits: ESA, P. Caraveo (IASF, Milan) Geminga's hot spot, panel (a) Panel (a) shows an image taken with the EPIC instrument on board the XMM-Newton observatory. The bright tails, made of particles kicked out by Gemingas strong magnetic field, trail the neutron star as it moves about in space. hi-res Size hi-res: 377 kb Credits: ESA, P. Caraveo (IASF, Milan) Geminga's hot spot, panel (b) Panel (b) shows how electrically charged particles interact with Gemingas magnetic field. For example, if electrons (blue) are kicked out by the star, positrons (red) hit the stars magnetic poles like in an own goal. hi-res Size hi-res: 435 kb Credits: ESA, P. Caraveo (IASF, Milan) Geminga's hot spot, panel (c) Panel (c) illustrates the size of Gemingas magnetic field (blue) compared to that of the star itself at the centre (purple). The magnetic field is tilted with respect to Gemingas rotation axis (red). hi-res Size hi-res: 121 kb Credits: ESA, P. Caraveo (IASF, Milan) Geminga's hot spot, panel (d) Panel (d) shows the magnetic poles of Geminga, where charged particles hit the surface of the star, creating a two-million degree hot spot, a region much hotter than the surroundings. As the star spins on its rotation axis, the hot spot comes into view and then disappears, causing the periodic colour change seen by XMM-Newton. Neutron stars are the smallest kind of stars known. They are the super-dense remnants of massive stars that died in cataclysmic explosions called supernovae. They have been thrown through space like cannonballs and set spinning at a furious rate, with magnetic fields hundreds of billions of times stronger than Earths. In the case of Geminga, this cannonball contains one and a half times the mass of the Sun, squeezed into a sphere just 20 kilometres across and spinning four times every second. A cloud bustling with electrically charged particles surrounds Geminga. These particles are shepherded by its magnetic and electric fields. ESAs XMM-Newton observatory had already discovered that some of these particles are ejected into space, forming tails that stream behind the neutron star as it hurtles along. Scientists did not know whether Gemingas tails are formed by electrons or by their twin particles with an opposite e

  16. Assessment of hot gas contaminant control

    SciTech Connect

    Rutkowski, M.D.; Klett, M.G.; Zaharchuk, R.

    1996-12-31

    The objective of this work is to gather data and information to assist DOE in responding to the NRC recommendation on hot gas cleanup by performing a comprehensive assessment of hot gas cleanup systems for advanced coal-based Integrated Gasification Combined Cycle (IGCC) and Pressurized Fluidized Bed Combustion (PFBC) including the status of development of the components of the hot gas cleanup systems, and the probable cost and performance impacts. The scope and time frame of information gathering is generally responsive to the boundaries set by the National Research council (NRC), but includes a broad range of interests and programs which cover hot gas cleanup through the year 2010. As the status of hot gas cleanup is continually changing, additional current data and information are being obtained for this effort from this 1996 METC Contractors` Review Meeting as well as from the 1996 Pittsburgh Coal Conference, and the University of Karlsruhe Symposium. The technical approach to completing this work consists of: (1) Determination of the status of hot gas cleanup technologies-- particulate collection systems, hot gas desulfurization systems, and trace contaminant removal systems; (2) Determination of hot gas cleanup systems cost and performance sensitivities. Analysis of conceptual IGCC and PFBC plant designs with hot gas cleanup have been performed. The impact of variations in hot gas cleanup technologies on cost and performance was evaluated using parametric analysis of the baseline plant designs and performance sensitivity.

  17. Atmospheric Escape From Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Murray-Clay, Ruth A.; Chiang, Eugene I.; Murray, Norman

    2009-03-01

    Photoionization heating from ultraviolet (UV) radiation incidents on the atmospheres of hot Jupiters may drive planetary mass loss. Observations of stellar Lyman-? (Ly?) absorption have suggested that the hot Jupiter HD 209458b is losing atomic hydrogen. We construct a model of escape that includes realistic heating and cooling, ionization balance, tidal gravity, and pressure confinement by the host star wind. We show that mass loss takes the form of a hydrodynamic (Parker) wind, emitted from the planet's dayside during lulls in the stellar wind. When dayside winds are suppressed by the confining action of the stellar wind, nightside winds might pick up if there is sufficient horizontal transport of heat. A hot Jupiter loses mass at maximum rates of ~2 1012 g s-1 during its host star's pre-main-sequence phase and ~2 1010 g s-1 during the star's main-sequence lifetime, for total maximum losses of ~0.06% and ~0.6% of the planet's mass, respectively. For UV fluxes F UV lsim 104 erg cm-2 s-1, the mass-loss rate is approximately energy limited and scales as \\dot{M} ? F_UV^{0.9}. For larger UV fluxes, such as those typical of T Tauri stars, radiative losses and plasma recombination force \\dot{M} to increase more slowly as F 0.6 UV. Dayside winds are quenched during the T Tauri phase because of confinement by overwhelming stellar wind pressure. During this early stage, nightside winds can still blow if the planet resides outside the stellar Alfvn radius; otherwise, even nightside winds are stifled by stellar magnetic pressure, and mass loss is restricted to polar regions. We conclude that while UV radiation can indeed drive winds from hot Jupiters, such winds cannot significantly alter planetary masses during any evolutionary stage. They can, however, produce observable signatures. Candidates for explaining why the Lyman-? photons of HD 209458 are absorbed at Doppler-shifted velocities of 100 km s-1 include charge-exchange in the shock between the planetary and stellar winds.

  18. Hot Gas in Planetary Nebulae

    E-print Network

    Y. -H. Chu; R. A. Gruendl; M. A. Guerrero

    2003-10-10

    Diffuse X-ray emission has been detected in a small number of planetary nebulae (PNe), indicating the existence of shocked fast stellar winds and providing support for the interacting-stellar-winds formation scenario of PNe. However, the observed X-ray luminosities are much lower than expected, similar to the situation seen in bubbles or superbubbles blown by massive stars. Ad hoc assumptions have been made to reconcile the discrepancy between observations and theoretical expectations. We have initiated FUSE programs to observe OVI absorption and emission from PNe, and our preliminary results indicate that OVI emission provides an effective diagnostic for hot gas in PN interiors.

  19. Hot Flow Anomalies at Venus

    NASA Technical Reports Server (NTRS)

    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

    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.

  20. Image Storage in Hot Vapors

    E-print Network

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

    2007-10-22

    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.

  1. Porous Barrier To Flow Of Hot Gas

    NASA Technical Reports Server (NTRS)

    Onstott, Joseph W.; Rietdyk, Jacob

    1992-01-01

    Porous, ropelike barrier prevents recirculating flow of hot, hydrogen-rich steam from reaching nickel-alloy bellows seal located deep in gap in wall of combustion chamber. Proven successful protecting bellows seal at different values of protrusion of coolant tubes giving rise to recirculating hot flow. Similar barriers help block deleterious recirculating flow of hot gases in other combustion chambers such as furnaces and turbomachines.

  2. Solar hot water unit and system

    SciTech Connect

    Ward, R.L.

    1982-02-16

    A solar hot water heating system includes a plurality of pipe assemblies, each having an outer pressure-sustaining tube and an inner perforated spiral tubing positioned at the roof of a building for which hot water is supplied. End seals close off the ends of the assemblies and support the inner tubing within the outer tubing. Water mixing and prevention of hot spots is accomplished passively by passing water through the spiral inner tubing. An economically favorable system is achieved.

  3. Hot spot and trench volcano separations

    NASA Technical Reports Server (NTRS)

    Lingenfelter, R. E.; Schubert, G.

    1974-01-01

    It is suggested that the distribution of separations between trench volcanos located along subduction zones reflects the depth of partial melting, and that the separation distribution for hot spot volcanoes near spreading centers provides a measure of the depth of mantle convection cells. It is further proposed that the lateral dimensions of mantle convection cells are also represented by the hot-spot separations (rather than by ridge-trench distances) and that a break in the distribution of hot spot separations at 3000 km is evidence for both whole mantle convection and a deep thermal plume origin of hot spots.

  4. Hot Gas In and Around Elliptical Galaxies

    E-print Network

    William G. Mathews; Fabrizio Brighenti

    2003-09-20

    We review the origin, evolution and physical nature of hot gas in elliptical galaxies and associated galaxy groups. Unanticipated recent X-ray observations with Chandra and XMM indicate much less cooling than previously expected. Consequently, many long-held assumptions need to be reexamined or discarded and new approaches must be explored. Chief among these are the role of heating by active galactic nuclei, the influence of radio lobes on the hot gas, details of the cooling process, possible relation between the hot and colder gas in elliptical galaxies, and the complexities of stellar enrichment of the hot gas.

  5. Physics of Massive Hot Stars

    NASA Astrophysics Data System (ADS)

    Hubeny, I.

    1994-05-01

    We discuss the impact of HST on our understanding of physics of hot massive stars. Since these stars are very luminous, they can be studied as individual stars in several parent galaxies. In order to take full advantage of the high spectral resolution and high signal-to-noise ratio offered by the HST spectra, new highly accurate and reliable methods of spectroscopic analysis have to be developed. We show that thanks to the recent dramatic advances in fast numerical methods it is now possible to construct model atmospheres of an unprecedented degree or realism and accuracy. We concentrate on two basic issues of the modern stellar atmospheres models of hot stars. First, we discuss the effects of departures from local thermodynamic equilibrium (referred to as non-LTE or NLTE). We show that model atmospheres are now becoming avaliable that include the opacity of tens to hundred thousand metal lines in full NLTE (the so-called NLTE line-blanketed model atmospheres). It is now possible to derive the basic stellar parameters (effective temperature, luminosity, chemical composition) to a high degree of accuracy. Second, we discuss models which do not employ the traditional core-halo approximation, i.e. an arbitrary separation of the static photosphere and the dynamic stellar wind -- the so-called unified model atmospheres. We review the recent research effort in this direction, and show several interpretational consequences of this methodological improvement.

  6. A&M. TAN607, interior of hot shop. Project underway in hot ...

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

    A&M. TAN-607, interior of hot shop. Project underway in hot shop. Note festoon wiring, manipulators, apparatus for shielding. Date: 1966. INEEL negative no. 66-6309 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

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

    SciTech Connect

    Key, M.H.; Estabrook, K.; Hammel, B.

    1997-12-01

    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.

  8. ADVANCED HOT GAS FILTER DEVELOPMENT

    SciTech Connect

    E.S. Connolly; G.D. Forsythe

    2000-09-30

    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.

  9. BOF steelmaking without hot metal

    SciTech Connect

    Gitman, G.; Galperine, G.; Grenader, I. ); Van der Merwe, F.O.; Newton, R.L. )

    1993-07-01

    This paper will discuss implementation of Z-BOP technology at Iscor's New Castle plant. The implementation program and operating results of Z-BOP-100 technology will be covered. The unique experience of the BOF shop operation without hot metal supply from the blast furnaces will also be described. This experience was a result of proprietary Z-BOP technology implementation at Iscor during its sole blast furnace reline. The Z-BOP is a family of technologies operating with scrap ratios in the charge from 30 to 100%. These technologies can be used in conventional top-blown BOF with virtually no equipment modifications. The principal additional energy source is lump coal, fed through existing BOF bin systems. Different modification of Z-BOP, originally used on the industrial scale at the West Siberian Steel Works, Russia, were utilized at several BOF facilities worldwide. Performance of the process and its main characteristics are discussed.

  10. Ceramic hot-gas filter

    DOEpatents

    Connolly, E.S.; Forsythe, G.D.; Domanski, D.M.; Chambers, J.A.; Rajendran, G.P.

    1999-05-11

    A ceramic hot-gas candle filter is described having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during back pulse cleaning and is resistant to chemical degradation at high temperatures.

  11. Ceramic hot-gas filter

    DOEpatents

    Connolly, Elizabeth Sokolinski (Wilmington, DE); Forsythe, George Daniel (Landenberg, PA); Domanski, Daniel Matthew (New Castle, DE); Chambers, Jeffrey Allen (Hockessin, DE); Rajendran, Govindasamy Paramasivam (Boothwyn, PA)

    1999-01-01

    A ceramic hot-gas candle filter having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during backpulse cleaning and is resistant to chemical degradation at high temperatures.

  12. TRUEX hot demonstration. Final report

    SciTech Connect

    Chamberlain, D.B.; Leonard, R.A.; Hoh, J.C.; Gay, E.C.; Kalina, D.G.; Vandegrift, G.F.

    1990-04-01

    In FY 1987, a program was initiated to demonstrate technology for recovering transuranic (TRU) elements from defense wastes. This hot demonstration was to be carried out with solution from the dissolution of irradiated fuels. This recovery would be accomplished with both PUREX and TRUEX solvent extraction processes. Work planned for this program included preparation of a shielded-cell facility for the receipt and storage of spent fuel from commercial power reactors, dissolution of this fuel, operation of a PUREX process to produce specific feeds for the TRUEX process, operation of a TRUEX process to remove residual actinide elements from PUREX process raffinates, and processing and disposal of waste and product streams. This report documents the work completed in planning and starting up this program. It is meant to serve as a guide for anyone planning similar demonstrations of TRUEX or other solvent extraction processing in a shielded-cell facility.

  13. Hot spots of mutualistic networks.

    PubMed

    Gilarranz, Luis J; Sabatino, Malena; Aizen, Marcelo A; Bascompte, Jordi

    2015-03-01

    Incorporating interactions into a biogeographical framework may serve to understand how interactions and the services they provide are distributed in space. We begin by simulating the spatiotemporal dynamics of realistic mutualistic networks inhabiting spatial networks of habitat patches. We proceed by comparing the predicted patterns with the empirical results of a set of pollination networks in isolated hills of the Argentinian Pampas. We first find that one needs to sample up to five times as much area to record interactions as would be needed to sample the same proportion of species. Secondly, we find that peripheral patches have fewer interactions and harbour less nested networks - therefore potentially less resilient communities - compared to central patches. Our results highlight the important role played by the structure of dispersal routes on the spatial distribution of community patterns. This may help to understand the formation of biodiversity hot spots. PMID:25402941

  14. The Hot Hand Belief and Framing Effects

    ERIC Educational Resources Information Center

    MacMahon, Clare; Kppen, Jrn; Raab, Markus

    2014-01-01

    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

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

    MedlinePLUS

    Facts About Hot Tub Rash and Swimmers Ear (Pseudomonas) What is Pseudomonas and how can it affect me? Pseudomonas (sue-doh- ... a major cause of infections commonly known as hot tub rash and swimmers ear. This germ is ...

  16. Recharging "Hot-Melt" Adhesive Film

    NASA Technical Reports Server (NTRS)

    Progar, D. J.

    1983-01-01

    Technique for recharging surface with "hot-melt" film makes use of one sided, high-temperature, pressure-sensitive adhesive tape. Purpose of the one-sided tape is to hold hot-melt charge in place until fused to surface. After adhesive has fused to surface and cooled, tape is removed, leaving adhesive on surface.

  17. Are we putting in hot water?

    E-print Network

    Combes, Stacey A.

    . But fish are increasingly threatened by global warming. Greenhouse gases released mainly by humans burningAre 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

  18. Hot Pages: Software Caching for Raw Microprocessors

    E-print Network

    Hot Pages: Software Caching for Raw Microprocessors Abstract This paper describes Hot Pages resources on the Raw microprocessor. Because virtualization is handled in software rather than hardware process challenging and costly. In addi- tion, as on-chip devices shrink, on-chip wires are becoming

  19. HotSpot Software Configuration Management Plan

    SciTech Connect

    Walker, H; Homann, S G

    2009-03-12

    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.

  20. HotSpot Software Test Plan

    SciTech Connect

    Walker, H; Homann, S G

    2009-03-12

    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.

  1. The bioavailability of benorylate in hot beverages.

    PubMed

    Barrett, N A; Pickup, M E; Lowe, J R; Wright, V; Downie, W W

    1978-02-01

    It has been recommended that benorylate may be administered with hot beverages to overcome the problem of its relative unpalatability. Urine salicylate recovery used as a measure of bioavailability in 20 normal subjects has shown that hot coffee has no significant effect on drug availability from the orally administered suspension. PMID:32608

  2. Hot-dry-rock feasibility study

    SciTech Connect

    Not Available

    1981-08-01

    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)

  3. Solar Energy for Space Heating & Hot Water.

    ERIC Educational Resources Information Center

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

    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.

  4. Basics of Solar Heating & Hot Water Systems.

    ERIC Educational Resources Information Center

    American Inst. of Architects, Washington, DC.

    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

  5. Turbine Engine Hot Section Technology, 1985

    NASA Technical Reports Server (NTRS)

    1985-01-01

    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.

  6. Demonstrating Integrated Pest Management of Hot Peppers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We studied the effects of organic and synthetic chemical fertilizers on crop growth, yield and associated insect pests for two varieties of hot pepper, Capsicum chinense Jacquin (Solanaceae): Scotch Bonnet and Caribbean Red in north Florida. Hot peppers were grown under three treatments: poultr...

  7. Fracture toughness of hot-pressed beryllium

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    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.

  8. Variational Theory of Hot Dense Matter

    ERIC Educational Resources Information Center

    Mukherjee, Abhishek

    2009-01-01

    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

  9. Hot Dry Rock; Geothermal Energy

    SciTech Connect

    1990-01-01

    The commercial utilization of geothermal energy forms the basis of the largest renewable energy industry in the world. More than 5000 Mw of electrical power are currently in production from approximately 210 plants and 10 000 Mw thermal are used in direct use processes. The majority of these systems are located in the well defined geothermal generally associated with crustal plate boundaries or hot spots. The essential requirements of high subsurface temperature with huge volumes of exploitable fluids, coupled to environmental and market factors, limit the choice of suitable sites significantly. The Hot Dry Rock (HDR) concept at any depth originally offered a dream of unlimited expansion for the geothermal industry by relaxing the location constraints by drilling deep enough to reach adequate temperatures. Now, after 20 years intensive work by international teams and expenditures of more than $250 million, it is vital to review the position of HDR in relation to the established geothermal industry. The HDR resource is merely a body of rock at elevated temperatures with insufficient fluids in place to enable the heat to be extracted without the need for injection wells. All of the major field experiments in HDR have shown that the natural fracture systems form the heat transfer surfaces and that it is these fractures that must be for geothermal systems producing from naturally fractured formations provide a basis for directing the forthcoming but, equally, they require accepting significant location constraints on HDR for the time being. This paper presents a model HDR system designed for commercial operations in the UK and uses production data from hydrothermal systems in Japan and the USA to demonstrate the reservoir performance requirements for viable operations. It is shown that these characteristics are not likely to be achieved in host rocks without stimulation processes. However, the long term goal of artificial geothermal systems developed by systematic engineering procedures at depth may still be attained if high temperature sites with extensive fracturing are developed or exploited. [DJE -2005

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

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... supply boilers, and unfired hot water storage tanks. 431.102 Section 431.102 Energy DEPARTMENT OF ENERGY... Water Heaters, Hot Water Supply Boilers and Unfired Hot Water Storage Tanks 431.102 Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water storage tanks. Link...

  11. 14 CFR 25.961 - Fuel system hot weather operation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...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...

  12. 14 CFR 25.961 - Fuel system hot weather operation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...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...

  13. 14 CFR 25.961 - Fuel system hot weather operation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...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...

  14. 14 CFR 25.961 - Fuel system hot weather operation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 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...

  15. 14 CFR 25.961 - Fuel system hot weather operation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...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...

  16. Volume reduction of hot cell plastic wastes

    SciTech Connect

    Dykes, F W; Henscheid, J P; Lewis, L C; Lundholm, C W; Nicklas, J H

    1989-09-19

    The disposal of radioactively-contaminated solid wastes has become a national crisis. In such circumstances, it is imperative that this waste be reduced to minimum volume and be packaged to prevent pollution of the environment. The majority of the solid waste generated at the hot cell under consideration is plastic lab ware. Cutting this waste into small pieces with a hot wire technique reduced the volume 66%. Melting the waste, although more time consuming, reduced the volume 90%. The hot wire technique can also be used to cut up damaged master slave manipulator boots, greatly reducing their disposal volume.

  17. Combining seismology and spectropolarimetry of hot stars

    E-print Network

    Neiner, Coralie; Mathis, Stphane; Degroote, Pieter

    2014-01-01

    Asteroseismology and spectropolarimetry have allowed us to progress significantly in our understanding of the physics of hot stars over the last decade. It is now possible to combine these two techniques to learn even more information about hot stars and constrain their models. While only a few magnetic pulsating hot stars are known as of today and have been studied with both seismology and spectropolarimetry, new opportunities - in particular Kepler2 and BRITE - are emerging and will allow us to rapidly obtain new combined results.

  18. Hot Jupiter Variability in Eclipse Depth

    E-print Network

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

    2007-05-03

    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.

  19. Grain evolution during hot forging

    NASA Astrophysics Data System (ADS)

    Jin, Quanlin

    2013-05-01

    A review on grain evolution during hot forging is presented in this paper. The discussion focus is on the experimental law, the microscopic mechanism, the physical model and the evolution equations of grain refinement and growth. This is because the grain evolution is the most important microstructure evolution effecting on the part mechanical behaviors, and to establish reasonable grain evolution is a very important and difficult work for macro microscopic coupling constitutive equation. The following contents about constitutive equation and grain evolution are discussed. 1) The experimental phenomena and evolution laws of grain growth and grain refinement under differential working conditions (deformation, heating, cooling) in order to adapt to the needs of numerical simulation of whole forging process. 2) The advantages and disadvantages of the traditional empirical equations on grain growth, grain refinement and recrystallization process are analyzed. 3) The recent advances in physic models for dynamic recrystallizaton and dynamic grain growth are introduced in detail. Comparing to the empirical equations, these models are closer to the actual physical process. The models not only describe the details of grain changes, but also reveal the relationship between the accumulated dislocations energy and grain size evolution. In addition, the assumptions used in the models and their influences on prediction function are also discussed in order to improve the models.

  20. Hot Leg Piping Materials Issues

    SciTech Connect

    V. Munne

    2006-07-19

    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).

  1. Charm and Beauty in a Hot Environment

    E-print Network

    Helmut Satz

    2006-02-28

    We discuss the spectral analysis of quarkonium states in a hot medium of deconfined quarks and gluons, and we show that such an analysis provides a way to determine the thermal properties of the quark-gluon plasma.

  2. Design data brochure: Solar hot air heater

    NASA Technical Reports Server (NTRS)

    1978-01-01

    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.

  3. Saturn's Hot Plasma Explosions - Duration: 81 seconds.

    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 ...

  4. Design data brochure: Solar hot water system

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A design calculation is detailed for a single-family residence housing a family of four in a nonspecific geographical area. The solar water heater system is designed to provide 80 gallons of 140 F hot water per day.

  5. Prototype solar heating and hot water systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Progress made in the development of a solar hot water and space heating system is described in four quarterly reports. The program schedules, technical status and other program activities from 6 October 1976 through 30 September 1977 are provided.

  6. Thermal dilepton production from hot QCD

    E-print Network

    M. Laine

    2015-02-20

    NLO and LPM-resummed computations of thermal dilepton production from a hot QCD plasma are reviewed. An interpolation applicable for all positive photon invariant masses is presented, and possibilities for comparisons with lattice and experimental data are pointed out.

  7. Toward Eclipse Mapping of Hot Jupiters

    E-print Network

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

    2007-04-24

    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.

  8. Turbine Engine Hot Section Technology (HOST) Project

    NASA Technical Reports Server (NTRS)

    Sokolowski, Daniel E.; Ensign, C. Robert

    1986-01-01

    The Hot Section Technology (HOST) Project is a NASA-sponsored endeavor to improve the durability of advanced gas turbine engines for commercial and military aircraft. Through improvements in the analytical models and life prediction systems, designs for future hot section components, the combustor and turbine, will be more accurately analyzed and will incorporate features required for longer life in the more hostile operating environment of high performance engines.

  9. HotSpot Health Physics Codes

    Energy Science and Technology Software Center (ESTSC)

    2013-04-18

    The HotSpot Health Physics Codes were created to provide emergency response personnel and emergency planners with a fast, field-portable set of software tools for evaluating insidents involving redioactive material. The software is also used for safety-analysis of facilities handling nuclear material. HotSpot provides a fast and usually conservative means for estimation the radiation effects associated with the short-term (less than 24 hours) atmospheric release of radioactive materials.

  10. World launch! Hot-Steam Aerostat

    E-print Network

    Berlin,Technische Universitt

    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 HeiDampfAeroStat (Hot-Steam AeroStat) and it refers to the first operable balloon ever that became buoyant by means of superheated steam. The performance of Hei

  11. Clinical care in the "Hot Zone".

    PubMed

    Byers, M; Russell, M; Lockey, D J

    2008-02-01

    The threat of chemical, biological, radiological and nuclear incidents is unlikely to decrease and preparations to deal with this type of incident are well established in most European emergency medical systems. In the UK medical care is not currently provided in the "Hot" or contaminated zone. This article discusses the background to the current threat and suggests that, where survivors are present in the "Hot Zone", medical care should be started there to minimise delay and maximise the chances of survival. PMID:18212153

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

    SciTech Connect

    Henderson, Hugh; Wade, Jeremy

    2014-04-01

    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 estimated to be on the order of 10%-30% of total domestic hot water (DHW) energy use. This field monitoring project installed temperature sensors on the distribution piping (on trunks and near fixtures) in five houses near Syracuse, NY, and programmed a data logger to collect data at 5 second intervals whenever there was a hot water draw. This data was used to assign hot water draws to specific end uses in the home as well as to determine the portion of each hot water that was deemed useful (i.e., above a temperature threshold at the fixture). Overall, the procedures to assign water draws to each end use were able to successfully assign about 50% of the water draws, but these assigned draws accounted for about 95% of the total hot water use in each home. The amount of hot water deemed as useful ranged from low of 75% at one house to a high of 91% in another. At three of the houses, new water heaters and distribution improvements were implemented during the monitoring period and the impact of these improvements on hot water use and delivery efficiency were evaluated.

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

    SciTech Connect

    Henderson, H.; Wade, J.

    2014-04-01

    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 estimated to be on the order of 10 to 30 percent of total domestic hot water (DHW) energy use. This field monitoring project installed temperature sensors on the distribution piping (on trunks and near fixtures) and programmed a data logger to collect data at 5 second intervals whenever there was a hot water draw. This data was used to assign hot water draws to specific end uses in the home as well as to determine the portion of each hot water that was deemed useful (i.e., above a temperature threshold at the fixture). Five houses near Syracuse NY were monitored. Overall, the procedures to assign water draws to each end use were able to successfully assign about 50% of the water draws, but these assigned draws accounted for about 95% of the total hot water use in each home. The amount of hot water deemed as useful ranged from low of 75% at one house to a high of 91% in another. At three of the houses, new water heaters and distribution improvements were implemented during the monitoring period and the impact of these improvements on hot water use and delivery efficiency were evaluated.

  14. Hot/Warm Gas Cleanup

    SciTech Connect

    Bissett, Larry A.

    2001-11-06

    Using regenerable sorbents and transport or fluid-bed contacting, the Gas Process Development Unit (GPDU) at NETL-Morgantown will be used to demonstrate the process feasibility of removing sulfur from coal gasification or other fuel gas streams at temperatures above dew point of the gas. This technology, also known as hot or warm gas desulfurization, is expected to remove sulfur to concentrations lower than conventional systems at comparable cost. The project was constructed under the U.S. Department of Energy (DOE) Integrated Gasification Combined Cycle (IGCC) power system program and is an ''enabling technology'' in the Vision 21 program. The GPDU was designed to be the smallest scale research and development facility capable of providing viable scale-up design data for new integrated transport or fluid-bed desulfurization processes. With the capability to test at process conditions representative of anticipated commercial applications in terms of temperatures, pressures, major compositions, velocities, and sorbent cycling, the unit is expected to generate important information on process control, configuration, and sorbent suitability. In this way, the GPDU fills a strategic role between past/current small-scale testing and large-scale demonstrations. A primary objective of the project is to gain insight into which reactor combination (i.e., both transport, both fluid bed, or mixed) is more suitable for desulfurization technology and why. Assuming process feasibility is demonstrated, this guides future development or commercial ventures by answering the question of what to build, and provides performance and scale-up data (e.g., required transport reactor densities). Another important objective, which naturally derives from the process development activities, is demonstration of sorbent suitability and readiness for commercial deployment (e.g., sorbent attrition and cycle life). In this sense, the GPDU can serve as a final testing ground to reduce the risks of large-scale sorbent failure.

  15. Concentrator hot-spot testing, phase 1

    NASA Technical Reports Server (NTRS)

    Gonzalez, C. C.

    1987-01-01

    Results of a study to determine the hot-spot susceptibility of concentrator cells, to provide a hot-spot qualification test for concentrator modules, and to provide guidelines for reducing hot-spot susceptibility are presented. Hot-spot heating occurs in a photovoltaic module when the short-circuit current of a cell is lower than the string operating current forcing the cell into reverse bias with a concurrent power dissipation. Although the basis for the concentrator module hot-spot qualification test is the test developed for flat-plate modules, issues, such as providing cell illumination, introduce additional complexities into the testing procedure. The same general guidelines apply for protecting concentrator modules from hot-spot stressing as apply to flat-plate modules. Therefore, recommendations are made on the number of bypass diodes required per given number of series cells per module or source circuit. In addition, a new method for determining the cell temperature in the laboratory or in the field is discussed.

  16. Canopy hot-spot as crop identifier

    SciTech Connect

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

    1986-05-01

    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.

  17. Deterministic Many-to-Many Hot Potato Routing Allan Borodin

    E-print Network

    Borodin, Allan

    Deterministic Many-to-Many Hot Potato Routing Allan Borodin Yuval Rabani Baruch Schieber Abstract We consider algorithms for many-to-many hot potato routing. In hot potato (deflection) routing in each time step. We consider a form of routing known as hot potato routing or deflection routing [1, 5

  18. 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

    ... 10 Energy 3 2010-01-01 2010-01-01 false Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water storage tanks. 431.102 Section 431.102 Energy DEPARTMENT OF ENERGY... Water Heaters, Hot Water Supply Boilers and Unfired Hot Water Storage Tanks 431.102...

  19. ADVANCED HOT GAS FILTER DEVELOPMENT

    SciTech Connect

    RICHARD A. WAGNER

    1998-09-04

    This report describes the fabrication and testing of continuous fiber ceramic composite (CFCC) based hot gas filters. The fabrication approach utilized a modified filament winding method that combined both continuous and chopped fibers into a novel microstructure. The work was divided into five primary tasks. In the first task, a preliminary set of compositions was fabricated in the form of open end tubes and characterized. The results of this task were used to identify the most promising compositions for sub-scale filter element fabrication and testing. In addition to laboratory measurements of permeability and strength, exposure testing in a coal combustion environment was performed to asses the thermo-chemical stability of the CFCC materials. Four candidate compositions were fabricated into sub-scale filter elements with integral flange and a closed end. Following the 250 hour exposure test in a circulating fluid bed combustor, the retained strength ranged from 70 t 145 percent of the as-fabricated strength. The post-test samples exhibited non-catastrophic failure behavior in contrast to the brittle failure exhibited by monolithic materials. Filter fabrication development continued in a filter improvement and cost reduction task that resulted in an improved fiber architecture, the production of a net shape flange, and an improved low cost bond. These modifications were incorporated into the process and used to fabricate 50 full-sized filter elements for testing in demonstration facilities in Karhula, Finland and at the Power Systems Development Facility (PSDF) in Wilsonville, AL. After 581 hours of testing in the Karhula facility, the elements retained approximately 87 percent of their as-fabricated strength. In addition, mechanical response testing at Virginia Tech provided a further demonstration of the high level of strain tolerance of the vacuum wound filter elements. Additional testing in the M. W. Kellogg unit at the PSDF has accumulated over 1800 hours of coal firing at temperatures of 760 C including a severe thermal upset that resulted in the failure of several monolithic oxide elements. No failures of any kind have been reported for the MTI CFCC elements in either of these test campaigns. Additional testing is planned at the M. W. Kellogg unit and Foster Wheeler unit at the PSDF over the next year in order to qualify for consideration for the Lakeland PCFB. Process scale-up issues have been identified and manufacturing plans are being evaluated to meet the needs of future demand.

  20. Experiments with the hot list strategy

    SciTech Connect

    Wos, L.

    1997-10-01

    Experimentation strongly suggests that, for attacking deep questions and hard problems with the assistance of an automated reasoning program, the more effective paradigms rely on the retention of deduced information. A significant obstacle ordinarily presented by such a paradigm is the deduction and retention of one or more needed conclusions whose complexity sharply delays their consideration. To mitigate the severity of the cited obstacle, the author formulates and features in this report the hot list strategy. The hot list strategy asks the researcher to choose, usually from among the input statements, one or more clauses that are conjectured to play a key role for assignment completion. The chosen clauses - conjectured to merit revisiting, again and again - are placed in an input list of clauses, called the hot list. When an automated reasoning program has decided to retain a new conclusion C - before any other clause is chosen to initiate conclusion drawing - the presence of a nonempty hot list (with an appropriate assignment of the input parameter known as heat) causes each inference rule in use to be applied to C together with the appropriate number of members of the hot list. Members of the hot list are used to complete applications of inference rules and not to initiate applications. The use of the hot list strategy thus enables an automated reasoning program to briefly consider a newly retained conclusion whose complexity would otherwise prevent its use for perhaps many CPU-hours. To give evidence of the value of the strategy, the author focuses on four contexts: (1) dramatically reducing the CPU time required to reach a desired goal; (2) finding a proof of a theorem that had previously resisted all but the more inventive automated attempts; (3) discovering a proof that is more elegant than previously known; and (4) answering a question that had steadfastly eluded researchers relying on an automated reasoning program.

  1. 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

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

    E-print Network

    Whitehouse, Kamin

    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

  3. HOT OFF THE PRESS www.rsc.org/npr | Natural Product Reports Hot off the press

    E-print Network

    Gates, Kent. S.

    HOT OFF THE PRESS www.rsc.org/npr | Natural Product Reports Hot off the press Robert A. Hill developments in bioorganic chemistry and novel natural products, such as the first naturally occurring an interest in the structure and biosynthesis of natural products and has been writing regular reviews

  4. HOT CELL BUILDING, TRA632. SHIELDING DOOR TO HOT CELL IS ...

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

    HOT CELL BUILDING, TRA-632. SHIELDING DOOR TO HOT CELL IS IN OPEN POSITION. DOOR SLIDES SHUT WITH HELP OF MANUALLY OPERATED CHAIN. STAIRWAY TO MEZZANINE IN VIEW AT LEFT. CAMERA FACES NORTHWEST. INL NEGATIVE NO. 9000. Unknown Photographer, 10/28/1953 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  5. A&M. Hot cell annex (TAN633) interior under construction. Hot cells ...

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

    A&M. Hot cell annex (TAN-633) interior under construction. Hot cells and their doors are along concrete wall. Note side wall of pumice block. Photographer: Jack L. Anderson. Date: October 28, 1957. INEEL negative no. 57-5335 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  6. Extracting hot carriers from photoexcited semiconductor nanocrystals

    SciTech Connect

    Zhu, Xiaoyang

    2014-12-10

    This research program addresses a fundamental question related to the use of nanomaterials in solar energy -- namely, whether semiconductor nanocrystals (NCs) can help surpass the efficiency limits, the so-called Shockley-Queisser limit, in conventional solar cells. In these cells, absorption of photons with energies above the semiconductor bandgap generates hot charge carriers that quickly cool to the band edges before they can be utilized to do work; this sets the solar cell efficiency at a limit of ~31%. If instead, all of the energy of the hot carriers could be captured, solar-to-electric power conversion efficiencies could be increased, theoretically, to as high as 66%. A potential route to capture this energy is to utilize semiconductor nanocrystals. In these materials, the quasi-continuous conduction and valence bands of the bulk semiconductor become discretized due to confinement of the charge carriers. Consequently, the energy spacing between the electronic levels can be much larger than the highest phonon frequency of the lattice, creating a phonon bottleneck wherein hot-carrier relaxation is possible via slower multiphonon emission. For example, hot-electron lifetimes as long as ~1 ns have been observed in NCs grown by molecular beam epitaxy. In colloidal NCs, long lifetimes have been demonstrated through careful design of the nanocrystal interfaces. Due to their ability to slow electronic relaxation, semiconductor NCs can in principle enable extraction of hot carriers before they cool to the band edges, leading to more efficient solar cells.

  7. Hot cell shield plug extraction apparatus

    SciTech Connect

    Knapp, P.A.; Manhart, L.K.

    1994-12-31

    A hot cell installation for the handling of highly radioactive material may comprise a dozen or more interconnected high density concrete vaults, the concrete vault walls having a thickness of approximately three feet. Typically, hot cells are constructed in rows so as to share as many shielding walls as possible. A typical overall length of a row of cells might be 70 yards. A secondary mechanism exists for placing certain objects into a cell. A typical hot cell has been constructed with 8 inch diameter holes through the exterior shielded walls in the vicinity of, and usually above, the viewing windows. It became evident that if the hot cell plugs could be removed and replaced conveniently significant savings in time and personnel exposure could be realized by using these 8 inch holes as entry ports. Fifteen inch cylindrical steel plugs with a diameter of eight inches weigh about two hundred pounds. The shield plug swing mechanism comprises a steel shielding plug mounted on a retraction device that enables the plug to be pulled out of the wall and supports the weight of the pulled out plug. The retraction device is mounted on a hinge, which allows the plug to be swung out of the way so that an operator can insert material into or remove it from the interior of the hot cell and then replace the plug quickly. The hinge mounting transmits the load of the retracted plug to the concrete wall.

  8. Four hot DOGs in the microwave

    E-print Network

    Frey, S; Gabnyi, K ; An, T

    2015-01-01

    Hot dust-obscured galaxies (hot DOGs) are a rare class of hyperluminous infrared galaxies identified with the Wide-field Infrared Survey Explorer (WISE) satellite. The majority of them is at high redshifts (z~2-3), at the peak epoch of star formation in the Universe. Infrared, optical, radio, and X-ray data suggest that hot DOGs contain heavily obscured, extremely luminous active galactic nuclei (AGN). This class may represent a short phase in the life of the galaxies, signifying the transition from starburst- to AGN-dominated phases. Hot DOGs are typically radio-quiet, but some of them show mJy-level emission in the radio (microwave) band. We observed four hot DOGs using the technique of very long baseline interferometry (VLBI). The 1.7-GHz observations with the European VLBI Network (EVN) revealed weak radio features in all sources. The radio is free from dust obscuration and, at such high redshifts, VLBI is sensitive only to compact structures that are characteristic of AGN activity. In two cases (WISE J07...

  9. Metamaterial perfect absorber based hot electron photodetection.

    PubMed

    Li, Wei; Valentine, Jason

    2014-06-11

    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

  10. Kepler constraints on planets near hot Jupiters

    SciTech Connect

    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.; /Caltech /Harvard-Smithsonian Ctr. Astrophys.

    2012-05-01

    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.

  11. Kepler constraints on planets near hot Jupiters.

    PubMed

    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

    We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3d) 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

  12. Hot gas filter and system assembly

    DOEpatents

    Lippert, T.E.; Palmer, K.M.; Bruck, G.J.; Alvin, M.A.; Smeltzer, E.E.; Bachovchin, D.M.

    1999-08-31

    A filter element is described for separating fine dirty particles from a hot gas. The filter element comprises a first porous wall and a second porous wall. Each porous wall has an outer surface and an inner surface. The first and second porous walls being coupled together thereby forming a substantially closed figure and open at one end. The open end is formed to be coupled to a hot gas clean up system support structure. The first and second porous walls define a channel beginning at the open end and terminate at the closed end through which a filtered clean gas can flow through and out into the clean gas side of a hot gas clean up system. 8 figs.

  13. Hot photocarrier dynamics in organic solar cells.

    PubMed

    Lane, P A; Cunningham, P D; Melinger, J S; Esenturk, O; Heilweil, E J

    2015-01-01

    Photocurrent in an organic solar cell is generated by a charge transfer reaction between electron donors and acceptors. Charge transfer is expected to proceed from thermalized states, but this picture has been challenged by recent studies that have investigated the role of hot excitons. Here we show a direct link between excess excitation energy and photocarrier mobility. Charge transfer from excited donor molecules generates hot photocarriers with excess energy coming from the offset between the lowest unoccupied molecular orbital of the donor and that of the acceptor. Hot photocarriers manifest themselves through a short-lived spike in terahertz photoconductivity that decays on a picosecond timescale as carriers thermalize. Different dynamics are observed when exciting the acceptor at its absorption edge to a thermalized state. Charge transfer in this case generates thermalized carriers described by terahertz photoconductivity dynamics consisting of an instrument-limited rise to a long-lived signal. PMID:26179323

  14. Hot photocarrier dynamics in organic solar cells

    NASA Astrophysics Data System (ADS)

    Lane, P. A.; Cunningham, P. D.; Melinger, J. S.; Esenturk, O.; Heilweil, E. J.

    2015-07-01

    Photocurrent in an organic solar cell is generated by a charge transfer reaction between electron donors and acceptors. Charge transfer is expected to proceed from thermalized states, but this picture has been challenged by recent studies that have investigated the role of hot excitons. Here we show a direct link between excess excitation energy and photocarrier mobility. Charge transfer from excited donor molecules generates hot photocarriers with excess energy coming from the offset between the lowest unoccupied molecular orbital of the donor and that of the acceptor. Hot photocarriers manifest themselves through a short-lived spike in terahertz photoconductivity that decays on a picosecond timescale as carriers thermalize. Different dynamics are observed when exciting the acceptor at its absorption edge to a thermalized state. Charge transfer in this case generates thermalized carriers described by terahertz photoconductivity dynamics consisting of an instrument-limited rise to a long-lived signal.

  15. Kepler constraints on planets near hot Jupiters

    PubMed Central

    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

    We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3d) 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

  16. Hot gas filter and system assembly

    DOEpatents

    Lippert, Thomas Edwin (Murrysville, PA); Palmer, Kathryn Miles (Monroeville, PA); Bruck, Gerald Joseph (Murrysville, PA); Alvin, Mary Anne (Pittsburgh, PA); Smeltzer, Eugene E. (Export, PA); Bachovchin, Dennis Michael (Murrysville, PA)

    1999-01-01

    A filter element for separating fine dirty particles from a hot gas. The filter element comprises a first porous wall and a second porous wall. Each porous wall has an outer surface and an inner surface. The first and second porous walls being coupled together thereby forming a substantially closed figure and open at one end. The open end is formed to be coupled to a hot gas clean up system support structure. The first and second porous walls define a channel beginning at the open end and terminate at the closed end through which a filtered clean gas can flow through and out into the clean gas side of a hot gas clean up system.

  17. Seeded hot dark matter models with inflation

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    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.

  18. Microbial ecology of hot desert edaphic systems.

    PubMed

    Makhalanyane, Thulani P; Valverde, Angel; Gunnigle, Eoin; Frossard, Aline; Ramond, Jean-Baptiste; Cowan, Don A

    2015-03-01

    A significant proportion of the Earth's surface is desert or in the process of desertification. The extreme environmental conditions that characterize these areas result in a surface that is essentially barren, with a limited range of higher plants and animals. Microbial communities are probably the dominant drivers of these systems, mediating key ecosystem processes. In this review, we examine the microbial communities of hot desert terrestrial biotopes (including soils, cryptic and refuge niches and plant-root-associated microbes) and the processes that govern their assembly. We also assess the possible effects of global climate change on hot desert microbial communities and the resulting feedback mechanisms. We conclude by discussing current gaps in our understanding of the microbiology of hot deserts and suggest fruitful avenues for future research. PMID:25725013

  19. Radioactive hot cell access hole decontamination machine

    DOEpatents

    Simpson, William E. (Richland, WA)

    1982-01-01

    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.

  20. Hot electron plasmon-protected solar cell.

    PubMed

    Kong, J; Rose, A H; Yang, C; Wu, X; Merlo, J M; Burns, M J; Naughton, M J; Kempa, K

    2015-09-21

    A solar cell based on a hot electron plasmon protection effect is proposed and made plausible by simulations, non-local modeling of the response, and quantum mechanical calculations. In this cell, a thin-film, plasmonic metamaterial structure acts as both an efficient photon absorber in the visible frequency range and a plasmonic resonator in the IR range, the latter of which absorbs and protects against phonon emission the free energy of the hot electrons in an adjacent semiconductor junction. We show that in this structure, electron-plasmon scattering is much more efficient than electron-phonon scattering in cooling-off hot electrons, and the plasmon-stored energy is recoverable as an additional cell voltage. The proposed structure could become a prototype of a new generation of high efficiency solar cells. PMID:26406739

  1. MAGNETIC DRAG ON HOT JUPITER ATMOSPHERIC WINDS

    SciTech Connect

    Perna, Rosalba; Menou, Kristen; Rauscher, Emily

    2010-08-20

    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.

  2. New sources for the hot oxygen geocorona

    NASA Technical Reports Server (NTRS)

    Richards, P. G.; Hickey, M. P.; Torr, D. G.

    1994-01-01

    This paper investigates new sources of thermospheric non thermal (hot) oxygen due to exothermic reactions involving numerous minor (ion and neutral) and metastable species. Numerical calculations are performed for low altitude, daytime, winter conditions, with moderately high solar activity and low magnetic activity. Under these conditions we find that the quenching of metastable species are a significant source of hot oxygen, with kinetic energy production rates a factor of ten higher than those due to previously considered O2(+) and NO(+) dissociative recombination reactions. Some of the most significant new sources of hot oxygen are reactions involving quenching of O(+)((sup 2)D), O((sup 1)D), N((sup 2)D), O(+)((sup 2)P) and vibrationally excited N2 by atomic oxygen.

  3. Dynamic stresses in weld metal hot cracking

    SciTech Connect

    Zacharia, T. . Materials Process Modeling Group)

    1994-07-01

    This paper presents the results of a study aimed at understanding the influence of dynamic stresses, induced by thermal and mechanical loading, on weld metal hot cracking. The study attempts to resolve the relationship between the dynamic stress distribution in the specimen, particularly near the trailing edge of the pool, and the observed cracking behavior in a Sigmajig test specimen. The transient stress distribution in the specimen resulting from mechanical and thermal loading was calculated for a Type 316 stainless steel specimen. The initiation and propagation of the crack during welding was visually monitored using a stroboscopic vision system. The numerical results were used to understand the initiation and propagation of weld metal hot cracks during controlled welding of a specimen subjected to external restraint. The results of this study indicate that for hot cracking to occur, there exists a dynamic relationship between the metallurgical and mechanical factors, which can be influenced by the welding conditions and mechanical restraint.

  4. Two New Variable Hot DQ Stars

    E-print Network

    B. N. Barlow; B. H. Dunlap; R. Rosen; J. C. Clemens

    2008-10-13

    We have discovered periodic variations in the light curves of two hot DQ stars from the Sloan Digital Sky Survey, SDSS J220029.08-074121.5 and SDSS J234843.30-094245.3. These are the second and third variables detected among the hot DQs and confirm the existence of a new class of variable white dwarf stars. The amplitudes of the variations are one half as large as those detected in the first discovered variable, SDSS J142625.71+575218.3, and required high signal-to-noise photometry to detect. The pulse shapes of the stars are not like those of known white dwarf pulsators but are similar to the first hot DQ variable, SDSS J142625.71+575218.3.

  5. Four hot DOGs in the microwave

    NASA Astrophysics Data System (ADS)

    Frey, Sndor; Paragi, Zsolt; Gabnyi, Krisztina va; An, Tao

    2016-01-01

    Hot dust-obscured galaxies (hot DOGs) are a rare class of hyperluminous infrared galaxies identified with the Wide-field Infrared Survey Explorer (WISE) satellite. The majority of them are at high redshifts (z 2-3), at the peak epoch of star formation in the Universe. Infrared, optical, radio, and X-ray data suggest that hot DOGs contain heavily obscured, extremely luminous active galactic nuclei (AGN). This class may represent a short phase in the life of the galaxies, signifying the transition from starburst- to AGN-dominated phases. Hot DOGs are typically radio-quiet, but some of them show mJy-level emission in the radio (microwave) band. We observed four hot DOGs using the technique of very long baseline interferometry (VLBI). The 1.7 GHz observations with the European VLBI Network (EVN) revealed weak radio features in all sources. The radio is free from dust obscuration and, at such high redshifts, VLBI is sensitive only to compact structures that are characteristic of AGN activity. In two cases (WISE J0757+5113, WISE J1603+2745), the flux density of the VLBI-detected components is much smaller than the total flux density, suggesting that 70-90 per cent of the radio emission, while still dominated by AGN, originates from angular scales larger than that probed by the EVN. The source WISE J1146+4129 appears a candidate compact symmetric object, and WISE J1814+3412 shows a 5.1 kpc double structure, reminiscent of hotspots in a medium-sized symmetric object. Our observations support that AGN residing in hot DOGs may be genuine young radio sources where starburst and AGN activities coexist.

  6. TOWARD CHEMICAL CONSTRAINTS ON HOT JUPITER MIGRATION

    SciTech Connect

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

    2014-10-10

    The origin of hot Jupitersgas giant exoplanets orbiting very close to their host starsis 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.

  7. Hot Spots in an Athermal System

    NASA Astrophysics Data System (ADS)

    Amon, Axelle; Nguyen, Van Bau; Bruand, Ary; Crassous, Jrme; Clment, Eric

    2012-03-01

    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.

  8. Hot dry rock venture risks investigation:

    SciTech Connect

    Not Available

    1988-01-01

    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.

  9. Cooling of hot electrons in amorphous silicon

    SciTech Connect

    Vanderhaghen, R.; Hulin, D.; Cuzeau, S.; White, J.O.

    1997-07-01

    Measurements of the cooling rate of hot carriers in amorphous silicon are made with a two-pump, one-probe technique. The experiment is simulated with a rate-equation model describing the energy transfer between a population of hot carriers and the lattice. An energy transfer rate proportional to the temperature difference is found to be consistent with the experimental data while an energy transfer independent of the temperature difference is not. This contrasts with the situation in crystalline silicon. The measured cooling rates are sufficient to explain the difficulty in observing avalanche effects in amorphous silicon.

  10. Stellar Wind -- Magnetosphere Interactions in Hot Jupiters

    E-print Network

    Buzasi, Derek L

    2015-01-01

    One potential star-planet interaction mechanism for hot Jupiters involves planetary heating via currents set up by interactions between the stellar wind and planetary magnetosphere. Early modeling results indicate that such currents, which are analogous to the terrestrial global electric circuit (GEC), have the potential to provide sufficient heating to account for the additional radius inflation seen in some hot Jupiters. Here we present a more detailed model of this phenomenon, exploring the scale of the effect, the circumstances under which it is likely to be significant, implications for the planetary magnetospheric structure, and observational signatures.

  11. Seismic evaluation of a hot cell structure

    SciTech Connect

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

    1995-07-01

    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.

  12. Evolution of Hot Gas in Elliptical Galaxies

    NASA Technical Reports Server (NTRS)

    Mathews, William G.

    2004-01-01

    This theory grant was awarded to study the curious nature, origin and evolution of hot gas in elliptical galaxies and their surrounding groups. Understanding the properties of this X-ray emitting gas has profound implications over the broad landscape of modern astrophysics: cosmology, galaxy formation, star formation, cosmic metal enrichment, galactic structure and dynamics, and the physics of hot gases containing dust and magnetic fields. One of our principal specific objectives was to interpret the marvelous new observations from the XMM and Chandru satellite X-ray telescopes.

  13. Validation of the Hot Strip Mill Model

    SciTech Connect

    Richard Shulkosky; David Rosberg; Jerrud Chapman

    2005-03-30

    The Hot Strip Mill Model (HSMM) is an off-line, PC based software originally developed by the University of British Columbia (UBC) and the National Institute of Standards and Technology (NIST) under the AISI/DOE Advanced Process Control Program. The HSMM was developed to predict the temperatures, deformations, microstructure evolution and mechanical properties of steel strip or plate rolled in a hot mill. INTEG process group inc. undertook the current task of enhancing and validating the technology. With the support of 5 North American steel producers, INTEG process group tested and validated the model using actual operating data from the steel plants and enhanced the model to improve prediction results.

  14. Quantum effects in the hot electron microbolometer

    SciTech Connect

    Tang, A.; Richards, P.L.

    1994-10-01

    The theory of the hot electron microbolometer proposed by Nahum et al. assumed that the photon energy is thermalized in the electrons in the Cu absorber before relaxing to the lattice. Since the photons initially excite individual electrons to K{omega}>>k{sub B}T, however, direct relaxation of these hot electrons to phonons must also be considered. Theoretical estimates suggest that this extra relaxation channel increases the effective thermal conductance for K{omega}>>k{sub B}T and influences bolometer noise. Calculations of these effects are presented which predict very useful performance both for ground-based and spacebased astronomical photometry at millimeter and submillimeter wavelengths.

  15. Controlled-Temperature Hot-Air Gun

    NASA Technical Reports Server (NTRS)

    Munoz, M. C.

    1986-01-01

    Materials that find applications in wind tunnels first tested in laboratory. Hot-Air Gun differs from commercial units in that flow rate and temperature monitored and controlled. With typical compressed-airsupply pressure of 25 to 38 psi (170 to 260 kPa), flow rate and maximum temperature are 34 stdft3/min (0.96 stdm3/min) and 1,090 degrees F (590 degrees C), respectively. Resembling elaborate but carefully regulated hot-air gun, setup used to apply blasts of air temperatures above 1,500 degrees F (815 degrees C) to test specimens.

  16. Anomalous ultrafast dynamics of hot plasmonic electrons in nanostructures with hot spots

    NASA Astrophysics Data System (ADS)

    Harutyunyan, Hayk; Martinson, Alex B. F.; Rosenmann, Daniel; Khorashad, Larousse Khosravi; Besteiro, Lucas V.; Govorov, Alexander O.; Wiederrecht, Gary P.

    2015-09-01

    The interaction of light and matter in metallic nanosystems is mediated by the collective oscillation of surface electrons, called plasmons. After excitation, plasmons are absorbed by the metal electrons through inter- and intraband transitions, creating a highly non-thermal distribution of electrons. The electron population then decays through electron-electron interactions, creating a hot electron distribution within a few hundred femtoseconds, followed by a further relaxation via electron-phonon scattering on the timescale of a few picoseconds. In the spectral domain, hot plasmonic electrons induce changes to the plasmonic resonance of the nanostructure by modifying the dielectric constant of the metal. Here, we report on the observation of anomalously strong changes to the ultrafast temporal and spectral responses of these excited hot plasmonic electrons in hybrid metal/oxide nanostructures as a result of varying the geometry and composition of the nanostructure and the excitation wavelength. In particular, we show a large ultrafast, pulsewidth-limited contribution to the excited electron decay signal in hybrid nanostructures containing hot spots. The intensity of this contribution correlates with the efficiency of the generation of highly excited surface electrons. Using theoretical models, we attribute this effect to the generation of hot plasmonic electrons from hot spots. We then develop general principles to enhance the generation of energetic electrons through specifically designed plasmonic nanostructures that could be used in applications where hot electron generation is beneficial, such as in solar photocatalysis, photodetectors and nonlinear devices.

  17. Kiln for hot-pressing compacts in a continuous manner

    DOEpatents

    Reynolds, Jr., Carl D. (Clinton, TN)

    1985-01-01

    The present invention is directed to a hot pressing furnace or kiln which is capable of preheating, hot pressing, and cooling a plurality of articles in a sequential and continuous manner. The hot pressing furnace of the present invention comprises an elongated, horizontally disposed furnace capable of holding a plurality of displaceable pusher plates each supporting a die body loaded with refractory or ceramic material to be hot pressed. Each of these plates and the die body supported thereby is sequentially pushed through the preheating zone, a temperature stabilizing and a hot pressing zone, and a cooling zone so as to provide a continuous hot-pressing operation of a plurality of articles.

  18. Kiln for hot-pressing compacts in a continuous manner

    DOEpatents

    Reynolds, C.D Jr.

    1983-08-08

    The invention is directed to a hot pressing furnace or kiln which is capable of preheating, hot pressing, and cooling a plurality of articles in a sequential and continuous manner. The hot pressing furnace of the present invention comprises an elongated, horizontally disposed furnace capable of holding a plurality of displaceable pusher plates each supporting a die body loaded with refractory or ceramic material to be hot pressed. Each of these plates and the die body supported thereby is sequentially pushed through the preheating zone, a temperature stabilizing and a hot pressing zone, and a cooling zone so as to provide a continuous hot-pressing operation of a plurality of articles.

  19. Glowing Hot Transiting Exoplanet Discovered

    NASA Astrophysics Data System (ADS)

    2003-04-01

    VLT Spectra Indicate Shortest-Known-Period Planet Orbiting OGLE-TR-3 Summary More than 100 exoplanets in orbit around stars other than the Sun have been found so far. But while their orbital periods and distances from their central stars are well known, their true masses cannot be determined with certainty, only lower limits. This fundamental limitation is inherent in the common observational method to discover exoplanets - the measurements of small and regular changes in the central star's velocity, caused by the planet's gravitational pull as it orbits the star. However, in two cases so far, it has been found that the exoplanet's orbit happens to be positioned in such a way that the planet moves in front of the stellar disk, as seen from the Earth. This "transit" event causes a small and temporary dip in the star's brightness, as the planet covers a small part of its surface, which can be observed. The additional knowledge of the spatial orientation of the planetary orbit then permits a direct determination of the planet's true mass. Now, a group of German astronomers [1] have found a third star in which a planet, somewhat larger than Jupiter, but only half as massive, moves in front of the central star every 28.5 hours . The crucial observation of this solar-type star, designated OGLE-TR-3 [2] was made with the high-dispersion UVES spectrograph on the Very Large Telescope (VLT) at the ESO Paranal Observatory (Chile). It is the exoplanet with the shortest period found so far and it is very close to the star, only 3.5 million km away. The hemisphere that faces the star must be extremely hot, about 2000 C and the planet is obviously losing its atmosphere at high rate . PR Photo 10a/03 : The star OGLE-TR-3 . PR Photo 10b/03 : VLT UVES spectrum of OGLE-TR-3. PR Photo 10c/03 : Relation between stellar brightness and velocity (diagram). PR Photo 10d/03 : Observed velocity variation of OGLE-TR-3. PR Photo 10e/03 : Observed brightness variation of OGLE-TR-3. The search for exoplanets More than 100 planets in orbit around stars other than the Sun have been found so far. These "exoplanets" come in many different sizes and they move in a great variety of orbits at different distances from their central star, some nearly round and others quite elongated. Some planets are five to ten times more massive than the largest one in the solar system, Jupiter - the lightest exoplanets known at this moment are about half as massive as Saturn, i.e. about 50 times more massive than the Earth. Astronomers are hunting exoplanets not just to discover more such objects, but also to learn more about the apparent diversity of planetary systems. The current main research goal is to eventually discover an Earth-like exoplanet, but the available telescopes and instrumentation are still not "sensitive" enough for this daunting task. However, also in this context, it is highly desirable to know not only the orbits of the observable exoplanets, but also their true masses . But this is not an easy task. Masses of exoplanets Virtually all exoplanets detected so far have been found by an indirect method - the measurement of stellar velocity variations . It is based on the gravitational pull of the orbiting planet that causes the central star to move a little back and forth; the heavier the planet, the greater is the associated change in the star's velocity. This technique is rapidly improving: the new HARPS spectrograph (High Accuracy Radial Velocity Planet Searcher) , now being tested on the 3.6-m telescope at the ESO La Silla Observatory , can measure such stellar motions with an unrivalled accuracy of about 1 metre per second (m/s), cf. ESO PR 06/03 . It will shortly be able to search for exoplanets only a few times more massive than the Earth. However, velocity measurements alone do not allow to determine the true mass of the orbiting planet. Because of the unknown inclination of the planetary orbit (to the line-of-sight), they only provide a lower limit to this mass . Additional information about this orbital inclination

  20. Hot Stars in the Galactic Halo

    NASA Astrophysics Data System (ADS)

    Adelman, Saul J.; Upgren, Arthur R.; Adelman, Carol J.

    2011-03-01

    Participants; Preface; Foreword; Acknowledgements; Part I. Introductory Papers: 1. What is the galaxy's halo population?; 2. Theoretical properties of horizontal-branch stars; 3. A review of A-type horizontal-branch stars; Part II. Surveys: 4. A progress report on the Edinburgh-Cape object survey; 5. A 300 square degree survey of young stars at high galactic latitudes; 6. The isolation of a new sample of B stars in the halo; 7. A northern catalog of FHB/A stars; 8. Recent progress on a continuing survey of galactic globular clusters for blue stragglers; 9. UV observations with FAUST and the galactic model; 10. Hot stars at the South Galactic Pole; Part III. Clusters: 11. Population II horizontal branches: a photometric study of globular clusters; 12. The period-shift effect in Oosterhoff type II globular clusters; 13. UV photometry of hot stars in omega centauri; 14. Spectroscopic and UBV observations of blue stars at the NGP; 15. Population I horizontal branches: probing the halo-to-disk transition; Part IV. Stars: 16. Very hot subdwarf O stars; 17. Quantitative spectroscopy of the very hot subluminous O-stars: K646, PG1159-035, and KPD0005+5106; 18. Analyzing the helium-rich hot sdO stars in the Palomar Green Survey; 19. Late type companions of hot sd O stars; 20. Hot stars in globular clusters; 21. Faint blue stars from the Hamburg Schmidt Survey; 22. Stellar winds and the evolution of sdB's to sdO's; 23. Halo stars in the Vilnius photometric system; 24. Horizontal branch stars in the geneva photometric system; 25. Zeeman observations of FHB stars and hot subdwarf stars; 26. What does a FHB star's spectrum look like?; 27. A technique for distinguishing FHB stars from A-type stars; 28. eEemental abundances of halo A and interloper stars; 29. The mass of blue horizontal branch stars in the globular cluster NGC6397; 30. IUE observations of blue HB stars in the globular clusters M3 and NGC6752; 31. Metallicities and kinematics of the local RR lyraes: lukewarm stars in the halo; 32. Baade-Wesselink analyses of field vs. cluster RR lyrae variables; 33. The rotation of population II A stars; 34. Horizontal branch stars and possibly related objects; 35. A new group of post-AGB objects - the hot carbon-poor stars; 36. MK classifications of hot stars in the halo 37. Photometry of XX Virginis and V716 Ophiuchi and the period luminosity relations of type II cepheids; 38. Rotation and oxygen line strengths in blue horizontal branch stars; Part V. Miscellaneous: 39. UBV CCd photometry of the halo of M31; 40. Can stars still form in the galactic halo?; 41. The ultraviolet imaging telescope on the Astro -1 and Astro -2 missions; 42. Are analogues of hot subdwarf stars responsible for the UVX phenomenon in galaxy nucleli; 43. A survey for field BHB stars outside the solar circle; 44. Post-AGB A and F supergiants as standard candles; 45. The extended horizontal-branch: a challenge for stellar evolution theory; 46. Astronomical patterns in fractals: the work of A. G. Davis Philip on the Mandelbrot Set; Part VI. Summary: 47. Final remarks; Author index; Subject index.

  1. World Trade Center Thermal Hot Spots

    USGS Multimedia Gallery

    Thermal hotspots around the World Trade Center after the terrorist attacks of September 11, 2001. The images show hot spots and fires still burning in the debris as of September 16, 2001, which were reduced or eliminated by September 23, 2001. These images were produced by the USGS from data gathere...

  2. Plasmas are Hot and Fusion is Cool

    SciTech Connect

    2011-01-01

    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.

  3. Teaching Earth Science Using Hot Air Balloons

    ERIC Educational Resources Information Center

    Kuhl, James; Shaffer, Karen

    2008-01-01

    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

  4. Element Abundance Determination in Hot Evolved Stars

    E-print Network

    Barnstedt, Jrgen

    and Astrophysics, Kepler Center for Astro and Particle Physics, University of Tubingen, Sand 1, 72076 T precise, to hot post-AGB stars. About 95% of all stars in our Galaxy end their life #12;2 Klaus Werner

  5. Relativistic particle transport in hot accretion disks

    NASA Technical Reports Server (NTRS)

    Becker, Peter A.; Kafatos, Menas; Maisack, Michael

    1994-01-01

    Accretion disks around rapidly rotating black holes provide one of the few plausible models for the production of intense radiation in Acitve Galactic Nuclei (AGNs) above energies of several hundred MeV. The rapid rotation of the hole increases the binding energy per nucleon in the last stable orbit relative to the Schwarzschild case, and naturally leads to ion temperatures in the range 10(exp 12) - 10(exp 13) K for sub-Eddington accretion rates. The protons in the hot inner region of a steady, two-temperature disk form a reservoir of energy that is sufficient to power the observed Energetic Gamma Ray Experiment Telescope (EGRET) outbursts if the black hole mass is 10(exp 10) solar mass. Moreover, the accretion timescale for the inner region is comparable to the observed transient timescale of approximately 1 week. Hence EGRET outbursts may be driven by instabilities in hot, two-temperature disks around supermassive black holes. In this paper we discuss turbulent (stochastic) acceleration in hot disks as a possible source of GeV particles and radiation. We constrain the model by assuming the turbulence is powered by a collective instability that drains energy from the hot protons. We also provide some ideas concerning new, high-energy Penrose processes that produce GeV emission be directly tapping the rotational energy of Kerr black holes.

  6. Hot Service Facility subsystem design description. Revision

    SciTech Connect

    1987-07-01

    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.

  7. Hot Carriers and Photoresponse in Graphene

    NASA Astrophysics Data System (ADS)

    Ma, Qiong

    2015-03-01

    The photoresponse of materials, which determines the performance of optoelectronic devices, is governed by energy relaxation pathways of photo-excited electron-hole pairs. In graphene, with the electron-lattice coupling strongly quenched by the vanishing electronic density of states, a novel transport regime is reached in which the photo-generated carrier population can remain hot while the lattice stays cool. In this talk, I will first show that light is converted to electrical currents in graphene p-n junctions through the hot-carrier assisted thermoelectric effect. The relaxation processes are subsequently examined by photocurrent measurements at different lattice temperatures, in which we observe a non-monotonic temperature dependence that can be understood as resulting from the competition between two hot electron cooling pathways: momentum-conserving normal collisions that dominate at low temperatures and disorder-assisted supercollisions that dominate at high temperatures. The peak temperature depends on carrier density and disorder concentration, thus allowing for an unprecedented way of controlling graphene's photoresponse. I will also show our observations of giant long-range photocurrent response in high-quality graphene transistor devices, which peaks at the charge neutrality point and exhibits highly ordered anti-symmetric spatial patterns with alternating photocurrent signs as a function of laser position. These patterns are strongly sensitive to device size and quality and occur in the absence of internal electrostatic or material interfaces, which may be related to the symmetry breaking on sample boundaries assisted by long-range hot carrier propagation.

  8. Solar-powered hot-air system

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Solar-powered air heater supplies part or all of space heating requirements of residential or commercial buildings and is interfaced with air to water heat exchanger to heat domestic hot water. System has potential application in drying agricultural products such as cotton, lumber, corn, grains, and peanuts.

  9. Storage capacity in hot dry rock reservoirs

    DOEpatents

    Brown, Donald W. (Los Alamos, NM)

    1997-01-01

    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

  10. Storage capacity in hot dry rock reservoirs

    DOEpatents

    Brown, D.W.

    1997-11-11

    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.

  11. SYNTHETIC BIOLOGY Hot TopicsWorkshop

    E-print Network

    Subramanian, Venkat

    SYNTHETIC BIOLOGY Hot TopicsWorkshop: Organized by Zhang Research Lab & Institute for School,simple sugars) into products through a"green" process.Synthetic biology is a fascinating and rapidly growing recent research topics in using synthetic biology to produce renewable transportation fuels. June 27

  12. Hot-dry-rock geothermal resource 1980

    SciTech Connect

    Heiken, G.; Goff, F.; Cremer, G.

    1982-04-01

    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.

  13. Six Hot Topics in Planetary Astronomy

    E-print Network

    David Jewitt

    2008-11-14

    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.

  14. Turbine Engine Hot Section Technology (HOST)

    NASA Technical Reports Server (NTRS)

    1982-01-01

    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.

  15. Facilities Bonds Prove Hot Item under Stimulus

    ERIC Educational Resources Information Center

    Klein, Alyson

    2009-01-01

    Construction bonding authority--a technical, and often obscure, source of capital funding for school districts--has emerged as a hot ticket for those looking to finance school facilities work under the federal government's economic-stimulus program. School districts left out of the loop for direct funding are lining up for some of at least $24

  16. 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...

  17. DRANKEN/DRINKS WARME DRANKEN HOT BEVERAGES

    E-print Network

    Twente, Universiteit

    macchiato coffee 2,70 Ristretto coffee 2,00 FRISDRANKEN SOFT DRINKS Frisdrank per glas Soft drink by the glass 2,00 Frisdrank per flesje Soft drink by the bottle 2,25 Sappen Juices 2,25 Verse Sappen FreschDRANKEN/DRINKS WARME DRANKEN HOT BEVERAGES Koffie/thee Coffee/tea 2,00 Cappuccino Cappuccino 2

  18. RADIOACTIVE METALLOFULLERENES: HOT ATOM CHEMISTRY ASPECTS.

    E-print Network

    Titov, Anatoly

    RADIOACTIVE METALLOFULLERENES: HOT ATOM CHEMISTRY ASPECTS. Yu.S.Grushko, M.A. Khodorkovski, V, in radioactive form, endometallofullerenes become the subject of new branch of radiochemistry and materials studies and monitoring of 1 #12;chemical properties of metallofullerenes, in technology of radioactive

  19. Microscale Effects from Global Hot Plasma Imagery

    NASA Technical Reports Server (NTRS)

    Moore, T. E.; Fok, M.-C.; Perez, J. D.; Keady, J. P.

    1995-01-01

    We have used a three-dimensional model of recovery phase storm hot plasmas to explore the signatures of pitch angle distributions (PADS) in global fast atom imagery of the magnetosphere. The model computes mass, energy, and position-dependent PADs based on drift effects, charge exchange losses, and Coulomb drag. The hot plasma PAD strongly influences both the storm current system carried by the hot plasma and its time evolution. In turn, the PAD is strongly influenced by plasma waves through pitch angle diffusion, a microscale effect. We report the first simulated neutral atom images that account for anisotropic PADs within the hot plasma. They exhibit spatial distribution features that correspond directly to the PADs along the lines of sight. We investigate the use of image brightness distributions along tangent-shell field lines to infer equatorial PADS. In tangent-shell regions with minimal spatial gradients, reasonably accurate PADs are inferred from simulated images. They demonstrate the importance of modeling PADs for image inversion and show that comparisons of models with real storm plasma images will reveal the global effects of these microscale processes.

  20. Hot topics in flavor physics at CDF

    SciTech Connect

    Jun, Soon Yung; /Carnegie Mellon U.

    2005-01-01

    Hot topics in flavor physics at CDF are reviewed. Selected results of top, beauty, charm physics and exotic states in about 200 pb{sup -1} data collected by the CDF II detector in p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron are presented.

  1. Travertine Hot Springs, Mono County, California

    SciTech Connect

    Chesterman, C.W.; Kleinhampl, F.J.

    1991-08-01

    This article is an abridgement of Special Report 172, Travertine Hot Springs at Bridgeport, Mono County, California, in preparation at the California Division of Mines and Geology. The Travertine Hot Springs area is on the northern edge of what many consider to be one of the most tectonically active areas in the United States. There is abundant geothermal and seismic activity. The landscape is dotted with volcanic features- cones, craters, domes, flows, fumaroles and hot springs-indicators of unrest in the present as well as reminders of activity in the past. Travertine, also known as calcareous sinter, is limestone formed by chemical precipitation of calcium carbonate (CaCO{sub 3}) from ground or surface waters. It forms stalactites and stalagmites in caves, fills some veins and spring conduits and can also be found at the mouths of springs, especially hot springs. The less compact variety is called tufa and the dense, banded variety is known as Mexican onyx, or onyx marble. True onyx, however, is a banded silicate.

  2. The hot corona of YY Mensae

    NASA Technical Reports Server (NTRS)

    Guedel, M.; Guinan, E. F.; Skinner, S. L.; Linsky, J. L.

    1996-01-01

    The results of a long time series of Rosat position sensitive proportional counter (PSPC) pointings are reported on together with the first Advanced Satellite for Cosmology and Astrophysics (ASCA) observation of the FK Comae-type star YY Mensae. This star reveals a hot dominant plasma of up to 3 keV, with less material at 0.7 keV.

  3. Transfer of hot dry rock technology

    SciTech Connect

    Smith, M.C.

    1985-11-01

    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.

  4. Nontuberculous mycobacterial disease following hot tub exposure.

    PubMed Central

    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

    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

  5. Microbial hotspots and hot moments in soil

    NASA Astrophysics Data System (ADS)

    Kuzyakov, Yakov; Blagodatskaya, Evgenia

    2015-04-01

    Soils are the most heterogeneous parts of the biosphere, with an extremely high differentiation of properties and processes within nano- to macroscales. The spatial and temporal heterogeneity of input of labile organics by plants creates microbial hotspots over short periods of time - the hot moments. We define microbial hotspots as small soil volumes with much faster process rates and much more intensive interactions compared to the average soil conditions. Such hotspots are found in the rhizosphere, detritusphere, biopores (including drilosphere) and on aggregate surfaces, but hotspots are frequently of mixed origin. Hot moments are short-term events or sequences of events inducing accelerated process rates as compared to the averaged rates. Thus, hotspots and hot moments are defined by dynamic characteristics, i.e. by process rates. For this hotspot concept we extensively reviewed and examined the localization and size of hotspots, spatial distribution and visualization approaches, transport of labile C to and from hotspots, lifetime and process intensities, with a special focus on process rates and microbial activities. The fraction of active microorganisms in hotspots is 2-20 times higher than in the bulk soil, and their specific activities (i.e. respiration, microbial growth, mineralization potential, enzyme activities, RNA/DNA ratio) may also be much higher. The duration of hot moments in the rhizosphere is limited and is controlled by the length of the input of labile organics. It can last a few hours up to a few days. In the detritusphere, however, the duration of hot moments is regulated by the output - by decomposition rates of litter - and lasts for weeks and months. Hot moments induce succession in microbial communities and intense intra- and interspecific competition affecting C use efficiency, microbial growth and turnover. The faster turnover and lower C use efficiency in hotspots counterbalances the high C inputs, leading to the absence of strong increases in C stocks. Consequently, the intensification of fluxes is much stronger than the increase of pools. Maintenance of stoichiometric ratios by accelerated microbial growth in hotspots requires additional nutrients (e.g. N and P), causing their microbial mining from soil organic matter, i.e. priming effects. Consequently, priming effects are localized in microbial hotspots and are consequences of hot moments. Finally, we estimated the contribution of the hotspots to the whole soil profile and suggested that, irrespective of their volume, the hotspots are mainly responsible for the ecologically relevant processes in soil.

  6. Hot-Jupiter Breakfasts Realign Stars

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-08-01

    Two researchers at the University of Chicago have recently developed a new theory to explain an apparent dichotomy in the orbits of planets around cool vs. hot stars. Their model proposes that the spins of cool stars are affected when they ingest hot Jupiters (HJs) early in their stellar lifetimes. A Puzzling Dichotomy: In exoplanet studies, there is a puzzling difference observed between planet orbits around cool and hot (those with Teff ? 6250 K) stars: the orbital planes of planets around cool stars are primarily aligned with the host star's spin, whereas the orbital planes of planets around hot stars seem to be randomly distributed. Previous attempts to explain this dichotomy have focused on tidal interactions between the host star and the planets observed in the system. Now Titos Matsakos and Arieh Knigl have taken these models a step further by including in their calculations not only the effects of observed planets, but also those of HJs that may have been swallowed by the star long before we observed the systems. Modeling Meals: Plots of the distribution of the obliquity ? for hot Jupiters around cool hosts (upper plot) and hot hosts (lower plot). The dashed line shows the initial distribution, the bins show the model prediction for the final distribution after the systems evolve, and the black dots show the current observational data. [Matsakos & Knigl, 2015]" class="size-thumbnail wp-image-223" height="386" src="http://aasnova.org/wp-content/uploads/2015/08/fig22-260x386.png" width="260" /> Plots of the distribution of the obliquity ? for hot Jupiters around cool hosts (upper plot) and hot hosts (lower plot). The dashed line shows the initial distribution, the bins show the model prediction for the final distribution after the systems evolve, and the black dots show the current observational data. [Matsakos & Knigl, 2015] The authors' model assumes that as HJs are formed and migrate inward through the protoplanetary disk, they stall out near the star (where they have periods of ~2 days) and get stranded as the gas disk evaporates around them. Tidal interactions can cause these planets to become ingested by the host star within 1 Gyr. Using Monte Carlo simulations, the authors model these star-planet tidal interactions and evolve a total of 10^6 systems: half with hot (Teff = 6400 K), main-sequence hosts, and half with cool (Teff = 5500 K), solar-type hosts. The initial obliquities the angle between the stellar spin and the planets' orbital angular momentum vectors are randomly distributed between 0 and 180. The authors find that early stellar ingestion of planets might be very common: to match observations, roughly half of all stellar hosts must ingest an HJ early in their lifetimes! This scenario results in a good match with observational data: about 50% of cool hosts' spins become roughly aligned with the orbital plane of their planets after they absorb the orbital angular momentum of the HJ they ingest. Hot stars, on the other hand, generally retain their random distributions of obliquity, because their angular momentum is typically higher than the orbital angular momentum of the ingested planet. Citation: Titos Matsakos and Arieh Knigl 2015, ApJ, 809, L20. doi: 10.1088/2041-8205/809/2/L20

  7. WESF hot cells waste minimization criteria hot cells window seals evaluation

    SciTech Connect

    Walterskirchen, K.M.

    1997-03-31

    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.

  8. Hot-Carrier Seebeck Effect: Diffusion and Remote Detection of Hot Carriers in Graphene.

    PubMed

    Sierra, Juan F; Neumann, Ingmar; Costache, Marius V; Valenzuela, Sergio O

    2015-06-10

    We investigate hot carrier propagation across graphene using an electrical nonlocal injection/detection method. The device consists of a monolayer graphene flake contacted by multiple metal leads. Using two remote leads for electrical heating, we generate a carrier temperature gradient that results in a measurable thermoelectric voltage V(NL) across the remaining (detector) leads. Due to the nonlocal character of the measurement, V(NL) is exclusively due to the Seebeck effect. Remarkably, a departure from the ordinary relationship between Joule power P and V(NL), V(NL) ? P, becomes readily apparent at low temperatures, representing a fingerprint of hot-carrier dominated thermoelectricity. By studying V(NL) as a function of bias, we directly determine the carrier temperature and the characteristic cooling length for hot-carrier propagation, which are key parameters for a variety of new applications that rely on hot-carrier transport. PMID:25950746

  9. The High Albedo of the Hot Jupiter Kepler-7 B

    E-print Network

    Demory, Brice-Olivier

    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 ...

  10. Insulation of Pipe Bends Improves Efficiency of Hot Oil Furnaces

    E-print Network

    Haseltine, D. M.; Laffitte, R. D.

    1999-01-01

    Thermodynamic analyses of processes indicated low furnace efficiencies on certain hot oil furnaces. Further investigation, which included Infrared (IR) thermography testing of several furnaces, identified extremely hot surfaces on the outside...

  11. 2. ELEVATOR DRIVE, CABLE MOTOR, CIRCUIT BOX, Hot Springs ...

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

    2. ELEVATOR DRIVE, CABLE MOTOR, CIRCUIT BOX, - 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

  12. 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

  13. 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

  14. 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

  15. Hot Water Heating System Operation and Energy Conservation

    E-print Network

    Shao, Z.; Chen, H.; Wei, P.

    2006-01-01

    Based on an example of the reconstruction of a hot water heating system, this paper provides an analysis and comparison of the operations of hot water heating systems, including supply water temperature adjustment, flow adjustment during each...

  16. 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

  17. 36 CFR 7.18 - Hot Springs National Park.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Hot Springs National Park. 7.18 Section 7.18 ...Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR...SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM 7.18 Hot...

  18. Hot Meets Cold Our galaxy, the Milky Way, is

    E-print Network

    Geller, Michael R.

    Hot Meets Cold Our galaxy, the Milky Way, is currently growing, although slowly, as clouds of gas in an infalling cloud and hot, low density gas in the Milky Way. Red represents the cold, dense gas in the cloud

  19. 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

  20. 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

  1. 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

  2. 13. Underside Span 1, Hot Metal Bridge on right toward ...

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

    13. Underside Span 1, Hot Metal Bridge on right toward Pier 1. - Monongahela Connecting Railroad Company, Hot Metal Bridge, Spanning Monongahela River at mile post 3.1, Pittsburgh, Allegheny County, PA

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

    E-print Network

    Amarnath, A.

    2008-01-01

    @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 compared to its annual use of electricity... 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...

  4. 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

  5. 21 CFR 880.6085 - Hot/cold water bottle.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Hot/cold water bottle. 880.6085 Section 880.6085... Devices 880.6085 Hot/cold water bottle. (a) Identification. A hot/cold water bottle is a device intended for medical purposes that is in the form of a container intended to be filled with hot or cold...

  6. 21 CFR 880.6085 - Hot/cold water bottle.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Hot/cold water bottle. 880.6085 Section 880.6085... Devices 880.6085 Hot/cold water bottle. (a) Identification. A hot/cold water bottle is a device intended for medical purposes that is in the form of a container intended to be filled with hot or cold...

  7. 21 CFR 880.6085 - Hot/cold water bottle.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Hot/cold water bottle. 880.6085 Section 880.6085... Devices 880.6085 Hot/cold water bottle. (a) Identification. A hot/cold water bottle is a device intended for medical purposes that is in the form of a container intended to be filled with hot or cold...

  8. 21 CFR 880.6085 - Hot/cold water bottle.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hot/cold water bottle. 880.6085 Section 880.6085... Devices 880.6085 Hot/cold water bottle. (a) Identification. A hot/cold water bottle is a device intended for medical purposes that is in the form of a container intended to be filled with hot or cold...

  9. 21 CFR 880.6085 - Hot/cold water bottle.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hot/cold water bottle. 880.6085 Section 880.6085... Devices 880.6085 Hot/cold water bottle. (a) Identification. A hot/cold water bottle is a device intended for medical purposes that is in the form of a container intended to be filled with hot or cold...

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

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

    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.

  11. 21 CFR 890.5710 - Hot or cold disposable pack.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Hot or cold disposable pack. 890.5710 Section...Therapeutic Devices 890.5710 Hot or cold disposable pack. (a) Identification. A hot or cold disposable pack is a device intended...

  12. 21 CFR 890.5710 - Hot or cold disposable pack.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Hot or cold disposable pack. 890.5710 Section...Therapeutic Devices 890.5710 Hot or cold disposable pack. (a) Identification. A hot or cold disposable pack is a device intended...

  13. 21 CFR 890.5710 - Hot or cold disposable pack.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Hot or cold disposable pack. 890.5710 Section...Therapeutic Devices 890.5710 Hot or cold disposable pack. (a) Identification. A hot or cold disposable pack is a device intended...

  14. 21 CFR 880.6085 - Hot/cold water bottle.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Hot/cold water bottle. 880.6085 Section 880...Miscellaneous Devices 880.6085 Hot/cold water bottle. (a) Identification. A hot/cold water bottle is a device intended for...

  15. 21 CFR 880.6085 - Hot/cold water bottle.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Hot/cold water bottle. 880.6085 Section 880...Miscellaneous Devices 880.6085 Hot/cold water bottle. (a) Identification. A hot/cold water bottle is a device intended for...

  16. 21 CFR 880.6085 - Hot/cold water bottle.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Hot/cold water bottle. 880.6085 Section 880...Miscellaneous Devices 880.6085 Hot/cold water bottle. (a) Identification. A hot/cold water bottle is a device intended for...

  17. Installation package for a solar heating and hot water system

    NASA Technical Reports Server (NTRS)

    1978-01-01

    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.

  18. 75 FR 8036 - Monitor-Hot Creek Rangeland Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-23

    ... Forest Service Monitor-Hot Creek Rangeland Project AGENCY: Forest Service, USDA. ACTION: Notice of intent... continued livestock grazing ] within the Monitor-Hot Creek Rangeland Project area. The analysis will... conditions within the Monitor-Hot Creek Rangeland Project area towards desired conditions. The project...

  19. 40 CFR 68.85 - Hot work permit.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 15 2011-07-01 2011-07-01 false Hot work permit. 68.85 Section 68.85 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CHEMICAL ACCIDENT PREVENTION PROVISIONS Program 3 Prevention Program 68.85 Hot work permit. (a) The owner or operator shall issue a hot work permit...

  20. 36 CFR 7.18 - Hot Springs National Park.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Hot Springs National Park. 7.18 Section 7...NATIONAL PARK SYSTEM 7.18 Hot Springs National Park. (a) Commercial Vehicles...water, hot or cold, from any of the springs, fountains, or other sources of...

  1. 36 CFR 7.18 - Hot Springs National Park.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Hot Springs National Park. 7.18 Section 7...NATIONAL PARK SYSTEM 7.18 Hot Springs National Park. (a) Commercial Vehicles...water, hot or cold, from any of the springs, fountains, or other sources of...

  2. 36 CFR 7.18 - Hot Springs National Park.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Hot Springs National Park. 7.18 Section 7...NATIONAL PARK SYSTEM 7.18 Hot Springs National Park. (a) Commercial Vehicles...water, hot or cold, from any of the springs, fountains, or other sources of...

  3. 36 CFR 7.18 - Hot Springs National Park.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Hot Springs National Park. 7.18 Section 7...NATIONAL PARK SYSTEM 7.18 Hot Springs National Park. (a) Commercial Vehicles...water, hot or cold, from any of the springs, fountains, or other sources of...

  4. 29 CFR 1915.503 - Precautions for hot work.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...SHIPYARD EMPLOYMENT Fire Protection in Shipyard...Precautions for hot work. (a) General...employees to perform hot work only in areas that are free of fire hazards, or that...1) Maintaining fire hazard-free conditions...must keep all hot work areas free of...

  5. 40 CFR 68.85 - Hot work permit.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...owner or operator shall issue a hot work permit for hot work operations conducted on or near...The permit shall document that the fire prevention and protection requirements...implemented prior to beginning the hot work operations; it shall indicate...

  6. 29 CFR 1915.503 - Precautions for hot work.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...SHIPYARD EMPLOYMENT Fire Protection in Shipyard...Precautions for hot work. (a) General...employees to perform hot work only in areas that are free of fire hazards, or that...1) Maintaining fire hazard-free conditions...must keep all hot work areas free of...

  7. 29 CFR 1915.503 - Precautions for hot work.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...SHIPYARD EMPLOYMENT Fire Protection in Shipyard...Precautions for hot work. (a) General...employees to perform hot work only in areas that are free of fire hazards, or that...1) Maintaining fire hazard-free conditions...must keep all hot work areas free of...

  8. 29 CFR 1915.503 - Precautions for hot work.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...SHIPYARD EMPLOYMENT Fire Protection in Shipyard...Precautions for hot work. (a) General...employees to perform hot work only in areas that are free of fire hazards, or that...1) Maintaining fire hazard-free conditions...must keep all hot work areas free of...

  9. 40 CFR 68.85 - Hot work permit.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...owner or operator shall issue a hot work permit for hot work operations conducted on or near...The permit shall document that the fire prevention and protection requirements...implemented prior to beginning the hot work operations; it shall indicate...

  10. 29 CFR 1915.503 - Precautions for hot work.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...SHIPYARD EMPLOYMENT Fire Protection in Shipyard...Precautions for hot work. (a) General...employees to perform hot work only in areas that are free of fire hazards, or that...1) Maintaining fire hazard-free conditions...must keep all hot work areas free of...

  11. 40 CFR 68.85 - Hot work permit.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...owner or operator shall issue a hot work permit for hot work operations conducted on or near...The permit shall document that the fire prevention and protection requirements...implemented prior to beginning the hot work operations; it shall indicate...

  12. 40 CFR 68.85 - Hot work permit.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...owner or operator shall issue a hot work permit for hot work operations conducted on or near...The permit shall document that the fire prevention and protection requirements...implemented prior to beginning the hot work operations; it shall indicate...

  13. 40 CFR 68.85 - Hot work permit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...owner or operator shall issue a hot work permit for hot work operations conducted on or near...The permit shall document that the fire prevention and protection requirements...implemented prior to beginning the hot work operations; it shall indicate...

  14. Intercomparison of general circulation models for hot extrasolar planets

    E-print Network

    Wirosoetisno, Djoko

    Intercomparison of general circulation models for hot extrasolar planets Article Accepted Version. (2014) Intercomparison of general circulation models for hot extrasolar planets. Icarus, 229 . pp. 355 circulation models (GCMs) which have been recently used to study hot extrasolar planet atmospheres (BOB, CAM

  15. 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

  16. 14 CFR 25.961 - Fuel system hot weather operation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel system hot weather operation. 25.961... hot weather operation. (a) The fuel system must perform satisfactorily in hot weather operation. This... simulated flight conditions. If a flight test is performed in weather cold enough to interfere with...

  17. 14 CFR 25.961 - Fuel system hot weather operation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel system hot weather operation. 25.961... hot weather operation. (a) The fuel system must perform satisfactorily in hot weather operation. This... simulated flight conditions. If a flight test is performed in weather cold enough to interfere with...

  18. 14 CFR 25.961 - Fuel system hot weather operation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel system hot weather operation. 25.961... hot weather operation. (a) The fuel system must perform satisfactorily in hot weather operation. This... simulated flight conditions. If a flight test is performed in weather cold enough to interfere with...

  19. 14 CFR 25.961 - Fuel system hot weather operation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel system hot weather operation. 25.961... hot weather operation. (a) The fuel system must perform satisfactorily in hot weather operation. This... simulated flight conditions. If a flight test is performed in weather cold enough to interfere with...

  20. 14 CFR 25.961 - Fuel system hot weather operation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel system hot weather operation. 25.961... hot weather operation. (a) The fuel system must perform satisfactorily in hot weather operation. This... simulated flight conditions. If a flight test is performed in weather cold enough to interfere with...

  1. X-rays from Hot Stars: Stellar Astronomy Research with

    E-print Network

    Cohen, David

    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

  2. OptimizingResourceUtilizationandTestability Using Hot Potato Techniques

    E-print Network

    Potkonjak, Miodrag

    OptimizingResourceUtilizationandTestability Using Hot Potato Techniques Miodrag Potkonjak Sujit Dey C&C Research Laboratories, NEC USA, Princeton, NJ 08540 ABSTRACT This paper introduces hot potato reduced using new technique. It is also dem- onstrated how hot potato techniques can be effectively used

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

    ERIC Educational Resources Information Center

    National Institute for Literacy, 2001

    2001-01-01

    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

  4. 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

    ... Energy 3 2010-01-01 2010-01-01 false Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water storage tanks. 431.102 Section 431.102 Energy DEPARTMENT OF ENERGY ENERGY...

  5. 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

    ... Energy 3 2011-01-01 2011-01-01 false Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water storage tanks. 431.102 Section 431.102 Energy DEPARTMENT OF ENERGY ENERGY...

  6. 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

    ... Energy 3 2013-01-01 2013-01-01 false Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water storage tanks. 431.102 Section 431.102 Energy DEPARTMENT OF ENERGY ENERGY...

  7. 10 CFR 431.102 - Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Energy 3 2014-01-01 2014-01-01 false Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water storage tanks. 431.102 Section 431.102 Energy DEPARTMENT OF ENERGY ENERGY...

  8. 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

    ... Energy 3 2012-01-01 2012-01-01 false Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water storage tanks. 431.102 Section 431.102 Energy DEPARTMENT OF ENERGY ENERGY...

  9. The Chilled Water and Hot Water Building Differential Pressure Setpoint Calculation - Chilled Water and Hot Water Pump Speed Control

    E-print Network

    Turner, W. D.; Bruner, H., Jr.; Claridge, D.; Liu, C.; Deng, S.

    2002-01-01

    Water and Hot Water Building Deferential Pressure Setpoint Calculation ? Chilled Water and Hot Water Pump Speed Control Chenggang Liu Research Associate Energy Systems Laboratory Texas A&M University College Station, TX Homer L. Bruner...&M University College Station, TX ABSTRACT More and more variable frequency devices (VFD) are being installed on the chilled water and hot water pumps on the TAMU campus. Those pump speeds are varied to maintain chilled water or hot water...

  10. Hot corrosion of the B2 nickel aluminides

    NASA Technical Reports Server (NTRS)

    Ellis, David L.

    1993-01-01

    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.

  11. 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

    ... 10 Energy 3 2012-01-01 2012-01-01 false Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water storage tanks. 431.102 Section 431.102 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Water Heaters, Hot Water Supply...

  12. Whistler Solitons in Plasma with Anisotropic Hot Electron Admixture

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Krivorutsky, E. N.; Gallagher, D. L.

    1999-01-01

    The longitudinal and transverse modulation instability of whistler waves in plasma, with a small admixture of hot anisotropic electrons, is discussed. If the hot particles temperature anisotropy is positive, it is found that, in such plasma, longitudinal perturbations can lead to soliton formation for frequencies forbidden in cold plasma. The soliton is enriched by hot particles. The frequency region unstable to transverse modulation in cold plasma in the presence of hot electrons is divided by stable domains. For both cases the role of hot electrons is more significant for whistlers with smaller frequencies.

  13. TWRS tank waste pretreatment process development hot test siting report

    SciTech Connect

    Howden, G.F.; Banning, D.L.; Dodd, D.A.; Smith, D.A.; Stevens, P.F.; Hansen, R.I.; Reynolds, B.A.

    1995-02-01

    This report is the sixth in a series that have assessed the hot testing requirements for TWRS pretreatment process development and identified the hot testing support requirements. This report, based on the previous work, identifies specific hot test work packages, matches those packages to specific hot cell facilities, and provides recommendations of specific facilities to be employed for the pretreatment hot test work. Also identified are serious limitations in the tank waste sample retrieval and handling infrastructure. Recommendations are provided for staged development of 500 mL, 3 L, 25 L and 4000 L sample recovery systems and specific actions to provide those capabilities.

  14. Toward improved durability in advanced aircraft engine hot sections

    NASA Technical Reports Server (NTRS)

    Sokolowski, Daniel E. (editor)

    1989-01-01

    The conference on durability improvement methods for advanced aircraft gas turbine hot-section components discussed NASA's Hot Section Technology (HOST) project, advanced high-temperature instrumentation for hot-section research, the development and application of combustor aerothermal models, and the evaluation of a data base and numerical model for turbine heat transfer. Also discussed are structural analysis methods for gas turbine hot section components, fatigue life-prediction modeling for turbine hot section materials, and the service life modeling of thermal barrier coatings for aircraft gas turbine engines.

  15. Turbine Engine Hot Section Technology 1986

    NASA Technical Reports Server (NTRS)

    1986-01-01

    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.

  16. Hot spots in an athermal system

    NASA Astrophysics Data System (ADS)

    Crassous, Jerome; Amon, Axelle; Bau Nguyen, Van; Bruand, Ary; Clement, Eric

    2012-02-01

    We study experimentally the dynamical heterogeneities occuring at slow shear, in a model amorphous glassy material i.e. a 3D granular packing. The deformation field is resolved spatially 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. Quantitively, their apparition is associated with the macroscopic plastic deformation and their rate of occurence gives a physical meaning to the concept of ``fluidity,'' recently used to describe the local and non-local rheology of soft glassy materials.

  17. Enabling Technologies for Ceramic Hot Section Components

    SciTech Connect

    Venkat Vedula; Tania Bhatia

    2009-04-30

    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.

  18. Magnetic effects in hot Jupiter atmospheres

    SciTech Connect

    Rogers, T. M.; Komacek, T. D.

    2014-10-20

    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 ?1400 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 ?10{sup 18} 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.

  19. Hot corrosion behavior of Nimonic-75

    SciTech Connect

    Gurrappa, I.

    1997-10-01

    Hot corrosion studies were conducted on Nimonic-75 superalloy in pure Na{sub 2}SO{sub 4} and 90% Na{sub 2}SO{sub 4} + 10% NaCl environments at 900 C for different time intervals. The results showed that Nimonic-75 exhibits good hot corrosion resistance in pure sodium sulfate, and the corrosion rate was enhanced considerably in the presence of 10% NaCl environment. It is also evident that the corrosion rate is time dependent and that the diffusion of corrosive species occurred toward the substrate. Based on these observations, an electrochemical model is proposed to show that the degradation of Nimonic-75 is an electrochemical phenomenon.

  20. An Optimization Study of Hot Stamping Operation

    NASA Astrophysics Data System (ADS)

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

    2010-06-01

    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.

  1. From cold to hot nuclear matter

    NASA Astrophysics Data System (ADS)

    Bratkovskaya, E. L.; Cassing, W.; Konchakovski, V. P.; Toneev, V. D.

    2015-11-01

    The dynamics of partons and hadrons in relativistic nucleus-nucleus collisions is analyzed within the Parton-Hadron-String Dynamics (PHSD) transport approach which is based on a dynamical quasiparticle model for the partonic phase (DQPM) including a dynamical hadronization scheme with covariant transition rates. The PHSD approach is applied to nucleus-nucleus collisions from FAIR/NICA to LHC energies. The traces of partonic interactions are found in particular in the directed and elliptic flow of hadrons and in their transverse mass spectra. Whereas at RHIC and LHC energies the dynamics is dominated by partonic degrees-of-freedom in the hot QGP, we find at FAIR/NICA energies a moderately hot but dense matter where chiral symmetry restoration and hadronic potentials appear to play a major role.

  2. X-rays from Hot Subdwarfs

    E-print Network

    Mereghetti, Sandro

    2015-01-01

    Thanks to the high sensitivity of the instruments on board the XMM-Newton and Chandra satellites, it has become possible to explore the properties of the X-ray emission from hot subdwarfs. The small but growing sample of hot subdwarfs detected in X-rays includes binary systems, in which the X-rays result from wind accretion onto a compact companion (white dwarf or neutron star), as well as isolated sdO stars in which X-rays are probably due to shock instabilities in the wind. X-ray observations of these low mass stars provide information which can be useful also for our understanding of the winds of more luminous and massive early-type stars and can lead to the discovery of particularly interesting binary systems.

  3. Hot water, fresh beer, and salt

    SciTech Connect

    Crawford, F.S. Physics Department, University of California, Berkeley, CA )

    1990-11-01

    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 CO{sub 2}) provided you first (a) get rid of much of the excess CO{sub 2} 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.

  4. Hot-Jupiter Breakfasts Realign Stars

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-01-01

    Two researchers at the University of Chicago have recently developed a new theory to explain an apparent dichotomy in the orbits of planets around cool vs. hot stars. Their model proposes that the spins of cool stars are affected when they ingest hot Jupiters (HJs) early in their stellar lifetimes.A Puzzling DichotomyIn exoplanet studies, there is a puzzling difference observed between planet orbits around cool and hot (those with Teff 6250 K) stars: the orbital planes of planets around cool stars are primarily aligned with the host stars spin, whereas the orbital planes of planets around hot stars seem to be randomly distributed.Previous attempts to explain this dichotomy have focused on tidal interactions between the host star and the planets observed in the system. Now Titos Matsakos and Arieh Knigl have taken these models a step further by including in their calculations not only the effects of observed planets, but also those of HJs that may have been swallowed by the star long before we observed the systems.Modeling MealsPlots of the distribution of the obliquity for hot Jupiters around cool hosts (upper plot) and hot hosts (lower plot). The dashed line shows the initial distribution, the bins show the model prediction for the final distribution after the systems evolve, and the black dots show the current observational data. [Matsakos Knigl, 2015]The authors model assumes that as HJs are formed and migrate inward through the protoplanetary disk, they stall out near the star (where they have periods of ~2 days) and get stranded as the gas disk evaporates around them. Tidal interactions can cause these planets to become ingested by the host star within 1 Gyr.Using Monte Carlo simulations, the authors model these star-planet tidal interactions and evolve a total of 10^6 systems: half with hot (Teff = 6400 K), main-sequence hosts, and half with cool (Teff = 5500 K), solar-type hosts. The initial obliquities the angle between the stellar spin and the planets orbital angular momentum vectors are randomly distributed between 0 and 180.The authors find that early stellar ingestion of planets might be very common: to match observations, roughly half of all stellar hosts must ingest an HJ early in their lifetimes!This scenario results in a good match with observational data: about 50% of cool hosts spins become roughly aligned with the orbital plane of their planets after they absorb the orbital angular momentum of the HJ they ingest. Hot stars, on the other hand, generally retain their random distributions of obliquity, because their angular momentum is typically higher than the orbital angular momentum of the ingested planet.CitationTitos Matsakos and Arieh Knigl2015 ApJ 809 L20 doi:10.1088/2041-8205/809/2/L20

  5. Hot Deformation Behavior of Bearing Steels

    NASA Astrophysics Data System (ADS)

    Moon, H. K.; Joun, M. S.; Lee, J. S.; Yoo, S. J.; Lee, J. K.

    2004-06-01

    The material behaviors of two types of bearing steels at hot working conditions are investigated. Stress-strain curves at various temperatures (9001,250C) and strain rates (150 /sec) are obtained by compression tests with a computer controlled servo-hydraulic Gleeble 3800 testing machine. Elongation and reduction of the area are also obtained by tensile tests. Flow stresses are calculated from the experiments and are used to predict the temperature distribution and the metal flow of a workpiece during a multi-stage hot forging process of a bearing race. A rigid-thermoviscoplastic finite element method is applied. The experimental and numerical results are summarized to reveal the reasons for internal crack formation.

  6. Hot water can freeze faster than cold?!?

    E-print Network

    Jeng, M

    2005-01-01

    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 ...

  7. Thermodynamics of pairing transition in hot nuclei

    NASA Astrophysics Data System (ADS)

    Liu, Lang; Zhang, Zhen-Hua; Zhao, Peng-Wei

    2015-10-01

    The pairing correlations in hot nuclei 162Dy are investigated in terms of the thermodynamical properties by covariant density functional theory. The thermodynamical quantities are evaluated by the canonical ensemble theory and the paring correlations are treated by a shell-model-like approach, in which the particle number is conserved exactly. An S-shaped heat capacity curve as a function of temperature has been obtained. The properties of hot nuclei, such as entropy and level density are studied in terms of defined seniority component. It is found that the one-pair-broken states play crucial roles in the appearance of the S shape of the heat capacity curve. Moreover, due to the effect of the particle-number conservation, the pairing gap varies smoothly with the temperature, which indicates a gradual transition from the superfluid to the normal state.

  8. Hierarchical Simulation of Hot Composite Structures

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Murthy, P. L. N.; Singhal, S. N.

    1993-01-01

    Computational procedures are described to simulate the thermal and mechanical behavior of high temperature metal matrix composites (HT-MMC) in the following three broad areas: (1) Behavior of HT-MMC's from micromechanics to laminate via Metal Matrix Composite Analyzer (METCAN), (2) tailoring of HT-MMC behavior for optimum specific performance via Metal Matrix Laminate Tailoring (MMLT), and (3) HT-MMC structural response for hot structural components via High Temperature Composite Analyzer (HITCAN). Representative results from each area are presented to illustrate the effectiveness of computational simulation procedures. The sample case results show that METCAN can be used to simulate material behavior such as strength, stress-strain response, and cyclic life in HTMMC's; MMLT can be used to tailor the fabrication process for optimum performance such as that for in-service load carrying capacity of HT-MMC's; and HITCAN can be used to evaluate static fracture and fatigue life of hot pressurized metal matrix composite rings.

  9. Method for hot pressing beryllium oxide articles

    DOEpatents

    Ballard, Ambrose H. (Oak Ridge, TN); Godfrey, Jr., Thomas G. (Oak Ridge, TN); Mowery, Erb H. (Clinton, TN)

    1988-01-01

    The hot pressing of beryllium oxide powder into high density compacts with little or no density gradients is achieved by employing a homogeneous blend of beryllium oxide powder with a lithium oxide sintering agent. The lithium oxide sintering agent is uniformly dispersed throughout the beryllium oxide powder by mixing lithium hydroxide in an aqueous solution with beryllium oxide powder. The lithium hydroxide is converted in situ to lithium carbonate by contacting or flooding the beryllium oxide-lithium hydroxide blend with a stream of carbon dioxide. The lithium carbonate is converted to lithium oxide while remaining fixed to the beryllium oxide particles during the hot pressing step to assure uniform density throughout the compact.

  10. Hot-water power from the earth

    SciTech Connect

    Not Available

    1984-02-01

    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.

  11. Hot forming graphite/polyimide structures

    NASA Technical Reports Server (NTRS)

    Baucom, R. M.; Kidder, P. W.

    1981-01-01

    Hot forming process has been developed in which structural shapes and panels are fabricated directly from stabilized graphite/polyimide preforms. Process can be used with thermosetting polymers that have high-temperature melt phase just before final cure. This phase allows fibers to move without destroying matrix-to-fiber adhesion. One of key advantages of this process is that prestages preforms are very stable and do not require refrigerated storage.

  12. Hadrons in Hot and Dense Matter

    E-print Network

    R. Rapp

    2002-09-24

    The description of excitations in hot and dense (hadronic) matter is discussed with emphasis on the use of correlation functions as a common framework for comparing different model (and QCD lattice) calculations with each other. Typical regimes of applicability of hadronic approaches are assessed, together with possibilities to confront them with experiment. We also elaborate on recent developments to relate baryonic in-medium effects to chiral symmetry restoration.

  13. THERMAL PROCESSES GOVERNING HOT-JUPITER RADII

    SciTech Connect

    Spiegel, David S.; Burrows, Adam E-mail: burrows@astro.princeton.edu

    2013-07-20

    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.

  14. Turbine Engine Hot Section Technology, 1984

    NASA Technical Reports Server (NTRS)

    1984-01-01

    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.

  15. Ethylene oxide and acetaldehyde in hot cores

    NASA Astrophysics Data System (ADS)

    Occhiogrosso, A.; Vasyunin, A.; Herbst, E.; Viti, S.; Ward, M. D.; Price, S. D.; Brown, W. A.

    2014-04-01

    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.

  16. Hot Magnetic Fibrils: The Slow Continuum Revisited

    NASA Astrophysics Data System (ADS)

    Keppens, R.

    1996-09-01

    We investigate the importance of the slow continuum (from linear, ideal magnetohydrodynamics [MHD]) for hot, evacuated, and strongly magnetic fibrils with nonnegligible radial structure. The radial structure allows for both slow and Alfvn resonant absorption of acoustic power (in linear, visco-resistive MHD). When calculating how efficiently the acoustic power is absorbed by such "hot magnetic fibrils," embedded in a uniform compressible medium, as a function of the real driving frequency, it is found that the axisymmetric component of the acoustic excitation is absorbed quite strongly for frequencies within the range of the slow continuum. Additionally, for these one-dimensional hot magnetic fibrils, a sequence of absorption maxima accumulates in real driving frequency above the range of the slow continuum, still within the Alfvn continuum. The maximal absorption coefficients reach 80% and more. We identify the complex optimal driving frequencies and the associated complex leaky eigenmodes responsible for these absorption maxima. The leaky eigenmodes relate to the well-known tube speed modes of a uniform, hot, and evacuated flux tube. The complex eigenfrequencies of the leaky eigenmodes of the radially structured fibrils are calculated from the impedance criterion that these eigenfrequencies satisfy. We define the generally complex optimal driving frequencies to be those driving frequencies at which total (100%) absorption of the incoming wave field takes place. They also obey an impedance criterion, similar to the one that defines the eigenfrequencies. Both impedance criteria demonstrate clearly the connection between optimal driving frequencies and leaky eigenmodes. This also calls for a reevaluation of the results of Goossens & Hollweg, in which optimal and total resonant absorption for real driving frequencies and the complex leaky eigenmodes was discussed. For network and plage magnetic elements in the solar atmosphere, our results may be relevant for wave interactions within a layer situated at a geometrical height of about 400 km above photospheric ? = 1.

  17. Environmental survey of Legionella pneumophila in hot springs in Taiwan.

    PubMed

    Lin, Yusen E; Lu, Wen-ming; Huang, Hsin-I; Huang, Wen-kuei

    2007-01-01

    Acquisition of sporadic community-acquired legionnaires' disease has been linked to hot springs and whirlpool baths. Outbreaks of hot spring-associated legionnaires' disease were reported in Japan in the last few years. Although the mode of transmission is unclear, the presence of Legionella in hot springs may discourage hot springs resort visits by the general public. An environmental survey was conducted to determine the presence of Legionella in hot springs in Taiwan. In total, 55 water samples were collected from 19 hot springs resorts; 21% (4/19) of the hot spring resorts sampled yielded L. pneumophila in the public hot springs bath. Legionella pneumophila serogroups 1 and 6, L. pneumophila serogroup 3, L. pneumophila serogroup 5, and L. pneumophila serogroup 7 were isolated from four different resort spas, respectively. The total sample positivity rate for L. pneumophila was 11% (6/55). The risk of occurrences of legionnaires' disease outbreaks associated with hot springs water in general public is unknown, and epidemiologic investigations should be conducted for locating the potential sources of Legionella for those cases of community-acquired legionnaires' disease. Disinfection of hot springs for Legionella may be necessary if the risk of contracting legionnaires' disease from hot springs can be validated by an evidence-based approach. PMID:17162501

  18. Hot filament CVD of boron nitride films

    DOEpatents

    Rye, Robert R. (Albuquerque, NM)

    1992-01-01

    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.

  19. The "hot hand" revisited: A nonstationarity argument.

    PubMed

    Sun, Yanlong; Wang, Hongbin

    2012-06-01

    The "hot hand belief," that a basketball player would experience elevated performance for a certain period of time, during which consecutive shots are made in streaks, has been suggested to be a "cognitive illusion," because, from the basketball-shooting data, no significant evidence has been found to reject the simple binomial model. The present study raises concerns about the statistical methods used to support this claim. It is argued that nonstationarity may manifest as a residual effect when the changes in shooting accuracy are interrupted by activities such as shot selection and defense effort. Reanalyses of the field goal data from the earlier study showed that the serial correlation varied substantially between positive ("hot hand shooting") and negative ("over-alternation shooting"). In addition, a nested model comparison revealed that when a player's shooting accuracy fluctuated substantially in a short period of time, it was unlikely to be detected by the binomial model. Our results suggest that paying special attention to streak patterns in the hot hand belief may be an adaptive strategy in detecting changes in the environment. PMID:26272665

  20. Hot-hand bias in rhesus monkeys.

    PubMed

    Blanchard, Tommy C; Wilke, Andreas; Hayden, Benjamin Y

    2014-07-01

    Human decision-makers often exhibit the hot-hand phenomenon, a tendency to perceive positive serial autocorrelations in independent sequential events. The term is named after the observation that basketball fans and players tend to perceive streaks of high accuracy shooting when they are demonstrably absent. That is, both observing fans and participating players tend to hold the belief that a player's chance of hitting a shot are greater following a hit than following a miss. We hypothesize that this bias reflects a strong and stable tendency among primates (including humans) to perceive positive autocorrelations in temporal sequences, that this bias is an adaptation to clumpy foraging environments, and that it may even be ecologically rational. Several studies support this idea in humans, but a stronger test would be to determine whether nonhuman primates also exhibit a hot-hand bias. Here we report behavior of 3 monkeys performing a novel gambling task in which correlation between sequential gambles (i.e., temporal clumpiness) is systematically manipulated. We find that monkeys have better performance (meaning, more optimal behavior) for clumped (positively correlated) than for dispersed (negatively correlated) distributions. These results identify and quantify a new bias in monkeys' risky decisions, support accounts that specifically incorporate cognitive biases into risky choice, and support the suggestion that the hot-hand phenomenon is an evolutionary ancient bias. PMID:25545977

  1. CNO driven winds of hot first stars

    E-print Network

    Jiri Krticka; Jiri Kubat

    2008-11-12

    During the evolution of first stars, the CNO elements may emerge on their surfaces due to the mixing processes. Consequently, these stars may have winds driven purely by CNO elements. We study the properties of such stellar winds and discuss their influence on the surrounding environment. For this purpose, we used our own NLTE models and tested which stellar parameters of the first stars at different evolutionary stages result in CNO winds. If such winds are possible, we calculate their hydrodynamic structure and predict their parameters. We show that, while the studied stars do not have any wind driven purely by hydrogen and helium, CNO driven winds exist in more luminous stars. On the other hand, for very hot stars, CNO elements are too ionized to drive a wind. In most cases the derived mass-loss rate is much less than calculated with solar mixture of elements. This is because wind mass-loss rate in present hot stars is dominated by elements heavier than CNO. We conclude that, until a sufficient amount of these elements is created, the influence of line-driven winds is relatively small on the evolution of hot stars (which are not close to the Eddington limit).

  2. Hot Dry Rock Geothermal Energy Development Program

    SciTech Connect

    Smith, M.C.; Hendron, R.H.; Murphy, H.D.; Wilson, M.G.

    1989-12-01

    During Fiscal Year 1987, emphasis in the Hot Dry Rock Geothermal Energy Development Program was on preparations for a Long-Term Flow Test'' of the Phase II'' or Engineering'' hot dry rock energy system at Fenton Hill, New Mexico. A successful 30-day flow test of the system during FY86 indicated that such a system would produce heat at a temperature and rate that could support operation of a commercial electrical power plant. However, it did not answer certain questions basic to the economics of long-term operation, including the rate of depletion of the thermal reservoir, the rate of water loss from the system, and the possibility of operating problems during extended continuous operation. Preparations for a one-year flow test of the system to answer these and more fundamental questions concerning hot dry rock systems were made in FY87: design of the required surface facilities; procurement and installation of some of their components; development and testing of slimline logging tools for use through small-diameter production tubing; research on temperature-sensitive reactive chemical tracers to monitor thermal depletion of the reservoir; and computer simulations of the 30-day test, extended to modeling the planned Long-Term Flow Test. 45 refs., 34 figs., 5 tabs.

  3. Hot DQ White Dwarfs: Something Different

    NASA Astrophysics Data System (ADS)

    Dufour, P.; Fontaine, G.; Liebert, James; Schmidt, G. D.; Behara, N.

    2008-08-01

    We present a detailed analysis of all the known hot DQ white dwarfs in the Fourth Data Release of the Sloan Digital Sky Survey (SDSS) recently found to have carbon-dominated atmospheres. Our spectroscopic and photometric analysis reveals that these objects all have effective temperatures between ~18,000 and 24,000 K. The surface composition is found to be completely dominated by carbon, as revealed by the absence of H? and He I ?4471 lines (or a determination of trace amounts in a few cases). We find that the surface gravity of all objects but one seems to be ``normal'' and around logg=8.0, while one is likely near logg=9.0. The presence of a weak magnetic field is directly detected by spectropolarimetry in one object and is suspected in two others. We propose that these strange stars could be cooled-down versions of the weird PG 1159 star H1504+65 and form a new family of hydrogen- and helium-deficient objects following the post-AGB phase. Finally, we present the results of full nonadiabatic calculations dedicated specifically to each of the hot DQs that show that only SDSS J142625.70+575218.4 is expected to exhibit luminosity variations. This result is in excellent agreement with recent observations by Montgomery et al., who find that J142625.70+575218.4 is the only pulsator among six hot DQ white dwarfs surveyed in 2008 February.

  4. ACCRETION OF ROCKY PLANETS BY HOT JUPITERS

    SciTech Connect

    Ketchum, Jacob A.; Adams, Fred C.; Bloch, Anthony M.

    2011-11-01

    The observed population of Hot Jupiters displays a stunning variety of physical properties, including a wide range of densities and core sizes for a given planetary mass. Motivated by the observational sample, this Letter studies the accretion of rocky planets by Hot Jupiters, after the Jovian planets have finished their principal migration epoch and become parked in {approx}4 day orbits. In this scenario, rocky planets form later and then migrate inward due to torques from the remaining circumstellar disk, which also damps the orbital eccentricity. This mechanism thus represents one possible channel for increasing the core masses and metallicities of Hot Jupiters. This Letter determines probabilities for the possible end states for the rocky planet: collisions with the Jovian planets, accretion onto the star, ejection from the system, and long-term survival of both planets. These probabilities depend on the mass of the Jovian planet and its starting orbital eccentricity, as well as the eccentricity damping rate for the rocky planet. Since these systems are highly chaotic, a large ensemble (N {approx} 10{sup 3}) of simulations with effectively equivalent starting conditions is required. Planetary collisions are common when the eccentricity damping rate is sufficiently low, but are rare otherwise. For systems that experience planetary collisions, this work determines the distributions of impact velocities-both speeds and impact parameters-for the collisions. These velocity distributions help determine the consequences of the impacts, e.g., where energy and heavy elements are deposited within the giant planets.

  5. Sol Duc Hot Springs feasibility study

    SciTech Connect

    Not Available

    1981-12-01

    Sol Duc Springs is located in the Olympic National Park in western Washington state. Since the turn of the century, the area has served as a resort, offering hot mineral baths, lodge and overnight cabin accommodations. The Park Service, in conjunction with the concessionaire, is in the process of renovating the existing facilities, most of which are approximately 50 years old. The present renovation work consists of removing all of the existing cabins and replacing them with 36 new units. In addition, a new hot pool is planned to replace the existing one. This report explores the possibility of a more efficient use of the geothermal resource to accompany other planned improvements. It is important to note that the system outlined is based upon the resource development as it exists currently. That is, the geothermal source is considered to be: the two existing wells and the hot springs currently in use. In addition, every effort has been made to accommodate the priorities for utilization as set forth by the Park Service.

  6. Residential hot water distribution systems: Roundtablesession

    SciTech Connect

    Lutz, James D.; Klein, Gary; Springer, David; Howard, Bion D.

    2002-08-01

    Residential building practice currently ignores the lossesof energy and water caused by the poor design of hot water systems. Theselosses include: combustion and standby losses from water heaters, thewaste of water (and energy) while waiting for hot water to get to thepoint of use; the wasted heat as water cools down in the distributionsystem after a draw; heat losses from recirculation systems and thediscarded warmth of waste water as it runs down the drain. Severaltechnologies are available that save energy (and water) by reducing theselosses or by passively recovering heat from wastewater streams and othersources. Energy savings from some individual technologies are reported tobe as much as 30 percent. Savings calculations of prototype systemsincluding bundles of technologies have been reported above 50 percent.This roundtable session will describe the current practices, summarizethe results of past and ongoing studies, discuss ways to think about hotwater system efficiency, and point to areas of future study. We will alsorecommend further steps to reduce unnecessary losses from hot waterdistribution systems.

  7. Hot air vulcanization of rubber profiles

    SciTech Connect

    Gerlach, J.

    1995-07-01

    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.

  8. Amorphous-silicon module hot-spot testing

    NASA Astrophysics Data System (ADS)

    Gonzalez, C. C.

    1985-06-01

    Hot spot heating occurs when cell short-circuit current is lower than string operating current. Amorphous cell hot spot are tested to develop the techniques required for performing reverse bias testing of amorphous cells. Also, to quantify the response of amorphous cells to reverse biasing. Guidelines are developed from testing for reducing hot spot susceptibility of amorphous modules and to develop a qualification test for hot spot testing of amorphous modules. It is concluded that amorphous cells undergo hot spot heating similarly to crystalline cells. Comparison of results obtained with submodules versus actual modules indicate heating levels lower in actual modules. Module design must address hot spot testing and hot spot qualification test conducted on modules showed no instabilities and minor cell erosion.

  9. HOT CELL BUILDING, TRA632, INTERIOR. HOT CELL NO. 1 (THE ...

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

    HOT CELL BUILDING, TRA-632, INTERIOR. HOT CELL NO. 1 (THE FIRST BUILT) IN LABORATORY 101. CAMERA FACES SOUTHEAST. SHIELDED OPERATING WINDOWS ARE ON LEFT (NORTH) SIDE. OBSERVATION WINDOW IS AT LEFT OF VIEW (ON WEST SIDE). PLASTIC COVERS SHROUD MASTER/SLAVE MANIPULATORS AT WINDOWS IN LEFT OF VIEW. NOTE MINERAL OIL RESERVOIR ABOVE "CELL 1" SIGN, INDICATING LEVEL OF THE FLUID INSIDE THE THICK WINDOWS. HOT CELL HAS BEVELED CORNER BECAUSE A SQUARED CORNER WOULD HAVE SUPPLIED UNNECESSARY SHIELDING. NOTE PUMICE BLOCK WALL AT LEFT OF VIEW. INL NEGATIVE NO. HD46-28-1. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  10. Organic Molecules in the Galactic Center. Hot Core Chemistry without Hot Cores

    E-print Network

    M. A. Requena-Torres; J. Martn-Pintado; A. Rodrguez-Franco; S. Martn; N. J. Rodrguez-Fernndez; P. de Vicente

    2006-05-18

    We study the origin of large abundances of complex organic molecules in the Galactic center (GC). We carried out a systematic study of the complex organic molecules CH3OH, C2H5OH, (CH3)2O, HCOOCH3, HCOOH, CH3COOH, H2CO, and CS toward 40 GC molecular clouds. Using the LTE approximation, we derived the physical properties of GC molecular clouds and the abundances of the complex molecules.The CH3OH abundance between clouds varies by nearly two orders of magnitude from 2.4x10^{-8} to 1.1x10^{-6}. The abundance of the other complex organic molecules relative to that of CH3OH is basically independent of the CH3OH abundance, with variations of only a factor 4-8. The abundances of complex organic molecules in the GC are compared with those measured in hot cores and hot corinos, in which these complex molecules are also abundant. We find that both the abundance and the abundance ratios of the complex molecules relative to CH3OH in hot cores are similar to those found in the GC clouds. However, hot corinos show different abundance ratios than observed in hot cores and in GC clouds. The rather constant abundance of all the complex molecules relative to CH3OH suggests that all complex molecules are ejected from grain mantles by shocks. Frequent (similar 10^{5}years) shocks with velocities >6km/s are required to explain the high abundances in gas phase of complex organic molecules in the GC molecular clouds. The rather uniform abundance ratios in the GC clouds and in Galactic hot cores indicate a similar average composition of grain mantles in both kinds of regions. The Sickle and the Thermal Radio Arches, affected by UV radiation, show different relative abundances in the complex organic molecules due to the differentially photodissociation of these molecules.

  11. HOT CELL BUILDING, TRA632, INTERIOR. DETAIL OF HOT CELL NO. ...

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

    HOT CELL BUILDING, TRA-632, INTERIOR. DETAIL OF HOT CELL NO. 2 SHOWS MANIPULATION INSTRUMENTS AND SHIELDED OPERATING WINDOWS. PENETRATIONS FOR OPERATING INSTRUMENTS GO THROUGH SHIELDING ABOVE WINDOWS. CONDUIT FOR UTILITIES AND CONTROLS IS BEHIND METAL CABINET BELOW WINDOWS NEAR FLOOR. CAMERA FACES WEST. WARNING SIGN LIMITS FISSILE MATERIAL TO SPECIFIED NUMBER OF GRAMS OF URANIUM AND PLUTONIUM. INL NEGATIVE NO. HD46-28-2. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  12. HOT CELL BUILDING, TRA632. CONTEXTUAL AERIAL VIEW OF HOT CELL ...

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

    HOT CELL BUILDING, TRA-632. CONTEXTUAL AERIAL VIEW OF HOT CELL BUILDING, IN VIEW AT LEFT, AS YET WITHOUT ROOF. PLUG STORAGE BUILDING LIES BETWEEN IT AND THE SOUTH SIDE OF THE MTR BUILDING AND ITS WING. NOTE CONCRETE DRIVE BETWEEN ROLL-UP DOOR IN MTR BUILDING AND CHARGING FACE OF PLUG STORAGE. REACTOR SERVICES BUILDING (TRA-635) WILL COVER THIS DRIVE AND BUTT UP TO CHARGING FACE. DOTTED LINE IS ON ORIGINAL NEGATIVE. TRA PARKING LOT IN LEFT CORNER OF THE VIEW. CAMERA FACING NORTHWESTERLY. INL NEGATIVE NO. 8274. Unknown Photographer, 7/2/1953 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  13. An evaluation of lead concentrations in imported hot sauces.

    PubMed

    Berger Ritchie, Jennifer A; Gerstenberger, Shawn L

    2013-01-01

    In the last decade, the U.S. Food and Drug Administration (FDA) has issued several warnings and recalls for food products that exceed FDA standards for lead. Products containing chili peppers and salt were often suspected as sources of lead contamination, and included items such as candy that are routinely investigated. However, products such as hot sauces that contain similar ingredients have not been the focus of evaluations. This study quantified lead concentrations in imported hot sauces, evaluated product compliance to existing United States standards, and calculated potential dietary lead exposure for children using the Integrated Exposure Uptake Biokinetic Model. Finally, recommendations for reducing the risk of lead exposure from hot sauces are provided. Twenty-five (25) bottles of imported hot sauces manufactured in Mexico and South America were purchased in Clark County, Nevada. All hot sauces were analyzed for lead concentrations, pH, and leaded packaging. Hot sauces were analyzed by inductively coupled plasma mass spectrometry and packaging was analyzed using x-ray fluorescence technology. Four brands of hot sauces (16%) exceeded 0.1 ppm lead, the current FDA action level for lead in candy. Hot sauces with lead concentrations >0.1 ppm lead contained salt and were manufactured in Mexico. Subsequent analysis of additional lots of hot sauces exceeding 0.1 ppm lead revealed inconsistent lead concentrations between and within manufacturer lots. The lead concentrations of the plastic hot sauce lids ranged from below the limit of detection to 2,028 ppm lead. There was no association between lead concentrations in hot sauces and pepper type. These results indicate the need for more rigorous screening protocols for products imported from Mexico, the establishment of an applicable standard for hot sauce, and resources to allow for the enforcement of existing food safety policies. The data reported herein represent the first known investigation of lead concentrations in hot sauces. PMID:23581685

  14. Accretion of Rocky Planets By Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Ketchum, Jake; Adams, F.; Bloch, A.

    2012-05-01

    The observed population of Hot Jupiters displays a stunning variety of physical properties, including a wide range of densities and core sizes for a given planetary mass. Motivated by the observational sample, this work studies the accretion of rocky planets by Hot Jupiters, after the Jovian planets have finished their principal migration epoch and become parked in 4 day orbits. In this scenario, rocky planets form later and then migrate inward due to torques from the remaining circumstellar disk, which also damps the orbital eccentricity. This mechanism thus represents one possible channel for increasing the core masses and metallicities of Hot Jupiters. This work determines probabilities for the possible end states for the rocky planet: collisions with the Jovian planets, accretion onto the star, ejection from the system, and long-term survival of both planet. These probabilities depend on the mass of the Jovian planet and its starting orbital eccentricity, as well as the eccentricity damping rate for the rocky planet. Since these systems are highly chaotic, a large ensemble (N 1000) of simulations with effectively equivalent starting conditions is required. Planetary collisions are common when the eccentricity damping rate is sufficiently low, but are rare otherwise. For systems that experience planetary collisions, this work determines the distributions of impact velocities -- both speeds and impact parameters -- for the collisions. These velocity distributions help determine the consequences of the impacts, e.g.,where energy and heavy elements are deposited within the giant planets. This work was supported by NSF grant DMS-0806756 from the Division of Applied Mathematics, NASA grant NNX11AK87G, and NSF grant DMS-0907949.

  15. Method for hot press forming articles

    DOEpatents

    Baker, Robert R. (Livonia, MI); Hartsock, Dale L. (Livonia, MI)

    1982-01-01

    This disclosure relates to an improved method for achieving the best bond strength and for minimizing distortion and cracking of hot pressed articles. In particular, in a method for hot press forming both an outer facing circumferential surface of and an inner portion of a hub, and of bonding that so-formed outer facing circumferential surface to an inner facing circumferential surface of a pre-formed ring thereby to form an article, the following improvement is made. Normally, in this method, the outside ring is restrained by a restraining sleeve of ring-shaped cross-section having an inside diameter. A die member, used to hot press form the hub, is so-formed as to have an outside diameter sized to engage the inside diameter of the restraining sleeve in a manner permitting relative movement therebetween. The improved method is one in which several pairs of matched restraining sleeve and die member are formed with each matched pair having a predetermined diameter. The predetermined diameter of each matched pair is different from another matched pair by stepped increments. The largest inside diameter of a restraining sleeve is equal to the diameter of the outer facing circumferential surface of the hub. Each pair of the matched restraining sleeve and die member is used to form an article in which an inside hub is bonded to an outside ring. The several samples so-formed are evaluated to determine which sample has the best bond formed between the hub and the ring with the least or no cracking or distortion in the ring portion of the article. Thereafter, the matched restraining sleeve and die member which form the article having the best bonding characteristics and least distortion cracking is then used for repeated formations of articles.

  16. Dragging $D$ mesons by hot hadrons

    E-print Network

    Sabyasachi Ghosh; Santosh K Das; Sourav Sarkar; Jan-e Alam

    2011-07-12

    We evaluate the drag and diffusion coefficients of a hot hadronic medium consisting of pions, nucleons, kaons and eta using open charm mesons as a probe. The interaction of the probe with the hadronic matter has been treated in the framework of effective field theory. It is observed that the magnitude of both the transport coefficients are significant, indicating substantial amount of interaction of the heavy mesons with the thermal hadronic system. The results may have noticeable impact on the experimental observable like the suppression of single electron spectra originating form the decays of heavy mesons in nuclear collisions at relativistic energies.

  17. Going ballistic: Graphene hot electron transistors

    NASA Astrophysics Data System (ADS)

    Vaziri, S.; Smith, A. D.; stling, M.; Lupina, G.; Dabrowski, J.; Lippert, G.; Mehr, W.; Driussi, F.; Venica, S.; Di Lecce, V.; Gnudi, A.; Knig, M.; Ruhl, G.; Belete, M.; Lemme, M. C.

    2015-12-01

    This paper reviews the experimental and theoretical state of the art in ballistic hot electron transistors that utilize two-dimensional base contacts made from graphene, i.e. graphene base transistors (GBTs). Early performance predictions that indicated potential for THz operation still hold true today, even with improved models that take non-idealities into account. Experimental results clearly demonstrate the basic functionality, with on/off current switching over several orders of magnitude, but further developments are required to exploit the full potential of the GBT device family. In particular, interfaces between graphene and semiconductors or dielectrics are far from perfect and thus limit experimental device integrity, reliability and performance.

  18. Hot rolling of thick uranium molybdenum alloys

    DOEpatents

    DeMint, Amy L.; Gooch, Jack G.

    2015-11-17

    Disclosed herein are processes for hot rolling billets of uranium that have been alloyed with about ten weight percent molybdenum to produce cold-rollable sheets that are about one hundred mils thick. In certain embodiments, the billets have a thickness of about 7/8 inch or greater. Disclosed processes typically involve a rolling schedule that includes a light rolling pass and at least one medium rolling pass. Processes may also include reheating the rolling stock and using one or more heavy rolling passes, and may include an annealing step.

  19. Pion stability in a hot dense media

    E-print Network

    M. Loewe; C. Villavicencio

    2011-07-19

    Pions may remain stable under certain conditions in a dense media at zero temperature in the normal phase (non pion superfluid state). The stability condition is achieved when the in-media pion width vanishes. However, thermal fluctuations will change this stable regime. For low temperature pions will remain in a metastable state. Here we discuss the different possible scenarios for leptonic pion decays at finite temperature, taking into account all the different chemical potentials involved. The neutrino emission due to pions in a hot-dense media is calculated, as well as the coolig rate of a pion-lepton gas.

  20. Phase boundary of hot dense fluid hydrogen

    PubMed Central

    Ohta, Kenji; Ichimaru, Kota; Einaga, Mari; Kawaguchi, Sho; Shimizu, Katsuya; Matsuoka, Takahiro; Hirao, Naohisa; Ohishi, Yasuo

    2015-01-01

    We investigated the phase transformation of hot dense fluid hydrogen using static high-pressure laser-heating experiments in a laser-heated diamond anvil cell. The results show anomalies in the heating efficiency that are likely to be attributed to the phase transition from a diatomic to monoatomic fluid hydrogen (plasma phase transition) in the pressure range between 82 and 106?GPa. This study imposes tighter constraints on the location of the hydrogen plasma phase transition boundary and suggests higher critical point than that predicted by the theoretical calculations. PMID:26548442

  1. Phase boundary of hot dense fluid hydrogen

    NASA Astrophysics Data System (ADS)

    Ohta, Kenji; Ichimaru, Kota; Einaga, Mari; Kawaguchi, Sho; Shimizu, Katsuya; Matsuoka, Takahiro; Hirao, Naohisa; Ohishi, Yasuo

    2015-11-01

    We investigated the phase transformation of hot dense fluid hydrogen using static high-pressure laser-heating experiments in a laser-heated diamond anvil cell. The results show anomalies in the heating efficiency that are likely to be attributed to the phase transition from a diatomic to monoatomic fluid hydrogen (plasma phase transition) in the pressure range between 82 and 106?GPa. This study imposes tighter constraints on the location of the hydrogen plasma phase transition boundary and suggests higher critical point than that predicted by the theoretical calculations.

  2. When hot water freezes before cold

    E-print Network

    J. I. Katz

    2006-04-27

    I suggest that the origin of the Mpemba effect (the freezing of hot water before cold) is freezing-point depression by solutes, either gaseous or solid, whose solubility decreases with increasing temperature so that they are removed when water is heated. They are concentrated ahead of the freezing front by zone refining in water that has not been heated, reduce the temperature of the freezing front, and thereby reduce the temperature gradient and heat flux, slowing the progress of the front. I present a simple calculation of this effect, and suggest experiments to test this hypothesis.

  3. Multiple volume compressor for hot gas engine

    DOEpatents

    Stotts, Robert E. (Clifton Park, NY)

    1986-01-01

    A multiple volume compressor for use in a hot gas (Stirling) engine having a plurality of different volume chambers arranged to pump down the engine when decreased power is called for and return the working gas to a storage tank or reservoir. A valve actuated bypass loop is placed over each chamber which can be opened to return gas discharged from the chamber back to the inlet thereto. By selectively actuating the bypass valves, a number of different compressor capacities can be attained without changing compressor speed whereby the capacity of the compressor can be matched to the power available from the engine which is used to drive the compressor.

  4. Control apparatus for hot gas engine

    DOEpatents

    Stotts, Robert E. (Clifton Park, NY)

    1986-01-01

    A mean pressure power control system for a hot gas (Stirling) engine utilizing a plurality of supply tanks for storing a working gas at different pressures. During pump down operations gas is bled from the engine by a compressor having a plurality of independent pumping volumes. In one embodiment of the invention, a bypass control valve system allows one or more of the compressor volumes to be connected to the storage tanks. By selectively sequencing the bypass valves, a capacity range can be developed over the compressor that allows for lower engine idle pressures and more rapid pump down rates.

  5. Hot tensile tests of Inconel 718

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The physical metallurgy of near-solidus integranular cracking in Inconel 718 welds was investigated. The data, although inconclusive, suggest at least two mechanisms which might explain intergranular cracking (microfissuring) in the heat-affected zone of several high temperature alloys. One theory is based on the separation of intergranular liquid while the other involves mechanical failure of solid ligaments surrounded by intergranular liquid. Both mechanisms concentrate strain in the grain boundaries resulting in low strain (1%) intergranular brittleness. The mechanisms reported might also pertain to the physical metallurgy of casting, powder metallurgy sintering and hot isostatic pressing.

  6. The flying hot wire and related instrumentation

    NASA Technical Reports Server (NTRS)

    Coles, D.; Cantnell, B.; Wadcock, A.

    1978-01-01

    A flying hot-wire technique is proposed for studies of separated turbulent flow in wind tunnels. The technique avoids the problem of signal rectification in regions of high turbulence level by moving the probe rapidly through the flow on the end of a rotating arm. New problems which arise include control of effects of torque variation on rotor speed, avoidance of interference from the wake of the moving arms, and synchronization of data acquisition with rotation. Solutions for these problems are described. The self-calibrating feature of the technique is illustrated by a sample X-array calibration.

  7. Prototype solar domestic hot water systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Construction of a double wall heat exchanger using soft copper tube coiled around a hot water storage tank was completed and preliminary tests were conducted. Solar transport water to tank potable water heat exchange tests were performed with a specially constructed test stand. Work was done to improve the component hardware and system design for the solar water heater. The installation of both a direct feed system and a double wall heat exchanger system provided experience and site data to enable informative decisions to be made as the solar market expands into areas where freeze protection is required.

  8. When hot water freezes before cold

    E-print Network

    Katz, J I

    2006-01-01

    I suggest that the origin of the Mpemba effect (the freezing of hot water before cold) is freezing-point depression by solutes, either gaseous or solid, whose solubility decreases with increasing temperature so that they are removed when water is heated. They are concentrated ahead of the freezing front by zone refining in water that has not been heated, reduce the temperature of the freezing front, and thereby reduce the temperature gradient and heat flux, slowing the progress of the front. I present a simple calculation of this effect, and suggest experiments to test this hypothesis.

  9. Hot Fuel Examination Facility/South

    SciTech Connect

    Not Available

    1990-05-01

    This document describes the potential environmental impacts associated with proposed modifications to the Hot Fuel Examination Facility/South (HFEF/S). The proposed action, to modify the existing HFEF/S at the Argonne National Laboratory-West (ANL-W) on the Idaho National Engineering Laboratory (INEL) in southeastern Idaho, would allow important aspects of the Integral Fast Reactor (IFR) concept, offering potential advantages in nuclear safety and economics, to be demonstrated. It would support fuel cycle experiments and would supply fresh fuel to the Experimental Breeder Reactor-II (EBR-II) at the INEL. 35 refs., 12 figs., 13 tabs.

  10. SSME hot gas manifold flow comparison test

    NASA Technical Reports Server (NTRS)

    Cox, G. B., Jr.; Dill, C. C.

    1988-01-01

    An account is given of the High Pressure Fuel Turbopump (HPFT) component of NASA's Alternate Turbopump Development effort, which is aimed at the proper aerodynamic integration of the current Phase II three-duct SSME Hot Gas Manifold (HGM) and the future 'Phase II-plus' two-duct HGM. Half-scale water flow tests of both HGM geometries were conducted to provide initial design data for the HPFT. The results reveal flowfield results and furnish insight into the performance differences between the two HGM flowpaths. Proper design of the HPFT can potentially secure significant flow improvements in either HGM configuration.

  11. Ventilation Requirements in Hot Humid Climates

    E-print Network

    Walker, I. S.; Sherman, M. H.

    2006-01-01

    stream_source_info ESL-HH-06-07-04.pdf.txt stream_content_type text/plain stream_size 28193 Content-Encoding UTF-8 stream_name ESL-HH-06-07-04.pdf.txt Content-Type text/plain; charset=UTF-8 VENTILATION REQUIREMENTS... IN HOT, HUMID CLIMATES I.S. Walker M. H. Sherman Staff Scientist Senior Scientist Lawrence Berkeley National Laboratory Berkeley CA ABSTRACT In 2003 ASHRAE approved the nations first residential ventilation standard, ASHRAE Standard...

  12. Noise shielding by a hot subsonic jet

    NASA Technical Reports Server (NTRS)

    Vijayaraghavan, A.; Parthasarathy, S. P.

    1981-01-01

    An analysis is conducted of the shielding of the noise emitted by a high speed round jet by a hot, subsonic, semicircular jet. A plane wave front in the primary jet is resolved into elementary plane waves which undergo multiple reflections at the jet boundaries of the primary and the shielding jets. The jet boundaries are idealized to be vortex sheets. The far field sound is evaluated asymptotically by a superposition of the waves that penetrate the shielding jet. The angular directivities are plotted for several values of jet temperature and velocity to examine the effectiveness of shielding by the semicircular jet layer.

  13. Hot Plasma Waves in Schwarzschild Magnetosphere

    E-print Network

    M. Sharif; Asma Rafique

    2009-11-03

    In this paper we examine the wave properties of hot plasma living in Schwarzschild magnetosphere. The 3+1 GRMHD perturbation equations are formulated for this scenario. These equations are Fourier analyzed and then solved numerically to obtain the dispersion relations for non-rotating, rotating non-magnetized and rotating magnetized plasma. The wave vector is evaluated which is used to calculate refractive index. These quantities are shown in graphs which are helpful to discuss the dispersive properties of the medium near the event horizon.

  14. Keeping sports participants safe in hot weather.

    PubMed

    Sparling, P B; Millard-Stafford, M

    1999-07-01

    Keeping in mind the key concepts of heat dissipation and using sound strategies for heat acclimatization and fluid replacement can help keep participants and spectators safe during hot-weather sports activities. Acclimatization to heat requires 10 to 14 days of training. Prudent hydration involves drinking plenty of fluid 2 hours before exercise, 5 to 10 oz of fluid every 15 minutes during exercise, and fluids with increased sodium content after exercise. A sidebar on environmental conditions and heat-related medical encounters during the 1996 Summer Olympics in Atlanta illustrates the importance of prevention strategies at the individual and event level. PMID:20086731

  15. Physics and chemistry of hot molecular cores

    E-print Network

    Henrik Beuther

    2006-10-13

    Young massive star-forming regions are known to produce hot molecular gas cores (HMCs) with a rich chemistry. While this chemistry is interesting in itself, it also allows to investigate important physical parameters. I will present recent results obtained with high-angular-resolution interferometers disentangling the small-scale structure and complexity of various molecular gas components. Early attempts to develop a chemical evolutionary sequence are discussed. Furthermore, I will outline the difficulty to isolate the right molecular lines capable to unambiguously trace potential massive accretion disks.

  16. Hot air drum evaporator. [Patent application

    DOEpatents

    Black, R.L.

    1980-11-12

    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.

  17. The Path of Hot Nuclei Towards Multifragmemtation

    E-print Network

    G. Papp; W. Nrenberg

    1995-06-19

    The initial production and dynamical expansion of hot spherical nuclei are examined as the first stage in the projectile-multifragmentation process. The initial temperatures, which are necessary for entering the adiabatic spinodal region, as well as the minimum temperatures and densities, which are reached in the expansion, significantly differ for hard and soft equations of state. Additional initial compression, occurring in central collisions leads most likely to a qualitatively different multifragmentation mechanism. Recent experimental data are discussed in relation to the results of the proposed model.

  18. Particulate hot gas stream cleanup technical issues

    SciTech Connect

    Pontius, D.H.; Snyder, T.R.

    1999-09-30

    The analyses of hot gas stream cleanup particulate samples and descriptions of filter performance studied under this contract were designed to address problems with filter operation that have been linked to characteristics of the collected particulate matter. One objective of this work was to generate an interactive, computerized data bank of the key physical and chemical characteristics of ash and char collected from operating advanced particle filters and to relate these characteristics to the operation and performance of these filters. The interactive data bank summarizes analyses of over 160 ash and char samples from fifteen pressurized fluidized-bed combustion and gasification facilities utilizing high-temperature, high pressure barrier filters.

  19. Hot cell shield plug extraction apparatus

    DOEpatents

    Knapp, Philip A. (Moore, ID); Manhart, Larry K. (Pingree, ID)

    1995-01-01

    An apparatus is provided for moving shielding plugs into and out of holes in concrete shielding walls in hot cells for handling radioactive materials without the use of external moving equipment. The apparatus provides a means whereby a shield plug is extracted from its hole and then swung approximately 90 degrees out of the way so that the hole may be accessed. The apparatus uses hinges to slide the plug in and out and to rotate it out of the way, the hinge apparatus also supporting the weight of the plug in all positions, with the load of the plug being transferred to a vertical wall by means of a bolting arrangement.

  20. Hot and Flowing, Asymmetric Nuclear Matter

    NASA Astrophysics Data System (ADS)

    Marranghello, G. F.; Vasconcellos, C. A. Z.

    2001-04-01

    We develop a consistent treatment for hot and flowing asymmetric nuclear matter. Using the mean-field theory (MFT), predictions of the ? - ? Walecka model at finite temperature are compared with the corresponding results of the Zimanyi-Moszkowski and the non-linear models. The statistical theory of grand-canonical potentials is incorporated to the formalism. We also describe the behavior, at finite temperature, of the asymmetric and flowing nuclear matter. As an application, we describe bulk properties of neutron and protoneutron stars by considering the Tolman-Oppenheimer-Volkoff (TOV) equations.

  1. Automated inspection of hot steel slabs

    DOEpatents

    Martin, R.J.

    1985-12-24

    The disclosure relates to a real time digital image enhancement system for performing the image enhancement segmentation processing required for a real time automated system for detecting and classifying surface imperfections in hot steel slabs. The system provides for simultaneous execution of edge detection processing and intensity threshold processing in parallel on the same image data produced by a sensor device such as a scanning camera. The results of each process are utilized to validate the results of the other process and a resulting image is generated that contains only corresponding segmentation that is produced by both processes. 5 figs.

  2. Automated inspection of hot steel slabs

    DOEpatents

    Martin, Ronald J. (Burnsville, MN)

    1985-01-01

    The disclosure relates to a real time digital image enhancement system for performing the image enhancement segmentation processing required for a real time automated system for detecting and classifying surface imperfections in hot steel slabs. The system provides for simultaneous execution of edge detection processing and intensity threshold processing in parallel on the same image data produced by a sensor device such as a scanning camera. The results of each process are utilized to validate the results of the other process and a resulting image is generated that contains only corresponding segmentation that is produced by both processes.

  3. Hot dry rock geothermal potential of Roosevelt Hot Springs area: review of data and recommendations

    SciTech Connect

    East, J.

    1981-05-01

    The Roosevelt Hot Springs area in west-central Utah possesses several features indicating potential for hot dry rock (HDR) geothermal development. The area is characterized by extensional tectonics and a high regional heat flow of greater than 105 mW/m/sup 2/. The presence of silicic volcanic rocks as young as 0.5 to 0.8 Myr and totaling 14 km/sup 3/ in volume indicates underlying magma reservoirs may be the heat source for the thermal anomaly. Several hot dry wells have been drilled on the periphery of the geothermal field. Information obtained on three of these deep wells shows that they have thermal gradients of 55 to 60/sup 0/C/km and bottom in impermeable Tertiary granitic and Precambrian gneissic units. The Tertiary granite is the preferred HDR reservoir rock because Precambrian gneissic rocks possess a well-developed banded foliation, making fracture control over the reservoir more difficult. Based on a fairly conservative estimate of 160 km/sup 2/ for the thermal anomaly present at Roosevelt Hot Springs, the area designated favorable for HDR geothermal exploration may be on the order of seven times or more than the hydrogeothermal area currently under development.

  4. Hydrogen-like nitrogen radio line from hot interstellar and warm-hot intergalactic gas

    E-print Network

    R. A. Sunyaev; D. Docenko

    2006-10-06

    Hyperfine structure lines of highly-charged ions may open a new window in observations of hot rarefied astrophysical plasmas. In this paper we discuss spectral lines of isotopes and ions abundant at temperatures 10^5-10^7 K, characteristic for warm-hot intergalactic medium, hot interstellar medium, starburst galaxies, their superwinds and young supernova remnants. Observations of these lines will allow to study bulk and turbulent motions of the observed target and will broaden the information about the gas ionization state, chemical and isotopic composition. The most prospective is the line of the major nitrogen isotope having wavelength 5.65 mm (Sunyaev and Churazov 1084). Wavelength of this line is well-suited for observation of objects at z=0.15-0.6 when it is redshifted to 6.5-9 mm spectral band widely-used in ground-based radio observations, and, for example, for z>=1.3, when the line can be observed in 1.3 cm band and at lower frequencies. Modern and future radio telescopes and interferometers are able to observe the absorption by 14-N VII in the warm-hot intergalactic medium at redshifts above z=0.15 in spectra of brightest mm-band sources. Sub-millimeter emission lines of several most abundant isotopes having hyperfine splitting might also be detected in spectra of young supernova remnants.

  5. HST hot Jupiter transmission spectral survey: The atmospheric circulation of a large hot Jupiter sample

    NASA Astrophysics Data System (ADS)

    Kataria, Tiffany; Sing, David K.; Lewis, Nikole K.; Fortney, Jonathan J.; Marley, Mark S.; Showman, Adam P.

    2015-11-01

    Even as we move towards characterizing smaller and cooler exoplanets, hot Jupiters continue to be the best transiting planets for probing the atmospheric properties of exoplanets and refining current theory. Here we present results from a comprehensive atmospheric circulation study of nine transiting hot Jupiters that probe a wide range of planetary properties, including orbital distance, rotation rate, mass, radius, gravity and stellar insolation. We utilize these circulation models to aid in the interpretation of transmission spectra obtained using the Space Telescope Imaging Spectrograph (STIS) and Wide Field Camera 3 (WFC3) as a part of a large Hubble Space Telescope (HST) transmission spectral survey. These observations have shown a range of spectral behavior over optical and infrared wavelengths, suggesting diverse cloud and haze properties in their atmospheres. Our grid of models recovers trends shown in other parametric studies of hot Jupiters, particularly increased day-night temperature contrast with increasing equilibrium temperature and equatorial superrotation. Furthermore, we show that three-dimensional variations in temperature, particularly across the western and eastern terminators and from the equator to the pole, can vary by hundreds of Kelvin. This can result in vastly different cloud properties across the limb, which can lead to variations in transmission spectra. Finally, we comment on prospects with the James Webb Space Telescope (JWST) to further characterize hot Jupiters out to longer wavelengths.

  6. Toward the Detection of Transiting Hot Earths and Hot Neptunes in Open Clusters

    E-print Network

    Joshua Pepper; B. Scott Gaudi

    2006-06-23

    Radial velocity searches for extrasolar planets have recently detected several very low mass (7-20M_Earth) planets in close orbits with periods Neptunes.'' Specifically, we present a simple criterion for detection that defines the minimum aperture required to detect planets of a given radius in a cluster at a given distance. Adopting photometric precisions that have been demonstrated in state-of-the-art variability surveys, we then predict the number of planets one could potentially detect with ambitious transit surveys toward several open clusters. Dedicated surveys lasting more than 20 nights with Pan-STARRS toward the Hyades and Praesepe could detect a handful of Hot Earths, if the majority of stars host such planets. Similar surveys with larger aperture telescopes (e.g. CFHT, MMT), toward M67, M35, M50, and M37 could detect Hot Neptunes, provided that their frequency is >1%. The majority of planets will be detected around M dwarfs; detecting Hot Neptunes around such primaries requires photometric precisions of ~1%, whereas Hot Earths require \\~0.1%. We discuss potential hurdles in detecting and confirming small planets in ground-based surveys, including correlated noise, false positives, and intrinsic stellar variability.

  7. Variability in Hot Carbon-Dominated Atmosphere (hot DQ) White Dwarfs: Rapid Rotation?

    E-print Network

    Williams, Kurtis A; Winget, D E; Falcon, Ross E; Bierwagon, Michael

    2015-01-01

    Hot white dwarfs with carbon-dominated atmospheres (hot DQs) are a cryptic class of white dwarfs. In addition to their deficiency of hydrogen and helium, most of these stars are highly magnetic, and a large fraction vary in luminosity. This variability has been ascribed to nonradial pulsations, but increasing data call this explanation into question. We present studies of short-term variability in seven hot DQ white dwarfs. Three (SDSS J1426+5752, SDSS J2200-0741, and SDSS J2348-0942) were known to be variable. Their photometric modulations are coherent over at least two years, and we find no evidence for variability at frequencies that are not harmonics. We present the first time-series photometry for three additional hot DQs (SDSS J0236-0734, SDSS J1402+3818, and SDSS J1615+4543); none are observed to vary, but the signal-to-noise is low. Finally, we present high speed photometry for SDSS J0005-1002, known to exhibit a 2.1 d photometric variation; we do not observe any short-term variability. Monoperiodicit...

  8. HST hot Jupiter transmission spectral survey: The atmospheric circulation of a large hot Jupiter sample

    NASA Astrophysics Data System (ADS)

    Kataria, Tiffany; Sing, David Kent; Lewis, Nikole K.; Fortney, Jonathan; Marley, Mark; Showman, Adam P.

    2015-12-01

    Even as we move towards characterizing smaller and cooler exoplanets, hot Jupiters continue to be the best transiting planets for probing the atmospheric properties of exoplanets and refining current theory. Here we present results from a comprehensive atmospheric circulation study of nine transiting hot Jupiters that probe a wide range of planetary properties, including orbital distance, rotation rate, mass, radius, gravity and stellar insolation. We utilize these circulation models to aid in the interpretation of transmission spectra obtained using the Space Telescope Imaging Spectrograph (STIS) and Wide Field Camera 3 (WFC3) as a part of a large Hubble Space Telescope (HST) transmission spectral survey. These observations have shown a range of spectral behavior over optical and infrared wavelengths, suggesting diverse cloud and haze properties in their atmospheres. Our grid of models recovers trends shown in other parametric studies of hot Jupiters, particularly increased day-night temperature contrast with increasing equilibrium temperature and equatorial superrotation. Furthermore, we show that three-dimensional variations in temperature, particularly across the western and eastern terminators and from the equator to the pole, can vary by hundreds of Kelvin. This can result in vastly different cloud properties across the limb, which can lead to variations in transmission spectra. Finally, we comment on prospects with the James Webb Space Telescope (JWST) to further characterize hot Jupiters out to longer wavelengths.

  9. DECOMMISSIONING OF HOT CELL FACILITIES AT THE BATTELLE COLUMBUS LABORATORIES

    SciTech Connect

    Weaver, Patrick; Henderson, Glenn; Erickson, Peter; Garber, David

    2003-02-27

    Battelle Columbus Laboratories (BCL), located in Columbus, Ohio, must complete decontamination and decommissioning activities for nuclear research buildings and grounds at its West Jefferson Facilities by 2006, as mandated by Congress. This effort includes decommissioning several hot cells located in the Hot Cell Laboratory (Building JN-1). JN-1 was originally constructed in 1955, and a hot cell/high bay addition was built in the mid 1970s. For over 30 years, BCL used these hot cell facilities to conduct research for the nuclear power industry and several government agencies, including the U.S. Navy, U.S. Army, U.S. Air Force, and the U.S. Department of Energy. As a result of this research, the JN-1 hot cells became highly contaminated with mixed fission and activation products, as well as fuel residues. In 1998, the Battelle Columbus Laboratories Decommissioning Project (BCLDP) began efforts to decommission JN-1 with the goal of remediating the site to levels of residual contamination allowing future use without radiological restrictions. This goal requires that each hot cell be decommissioned to a state where it can be safely demolished and transported to an off-site disposal facility. To achieve this, the BCLDP uses a four-step process for decommissioning each hot cell: (1) Source Term Removal; (2) Initial (i.e., remote) Decontamination; (3) Utility Removal; and (4) Final (i.e., manual) Decontamination/Stabilization. To date, this process has been successfully utilized on 13 hot cells within JN-1, with one hot cell remaining to be decommissioned. This paper will provide a case study of the hot cell decommissioning being conducted by the BCLDP. Discussed will be the methods used to achieve the goals of each of the hot cell decommissioning stages and the lessons learned that could be applied at other sites where hot cells need to be decommissioned.

  10. Hot cell facility design for large fusion devices

    SciTech Connect

    Barrett, R.J.; Bussell, G.T.

    1985-01-01

    Large hot cell facilities will be necessary to support the operation of large fusion devices. The supporting hot cells will be needed to serve a variety of different functions and tasks, which include reactor component maintenance, tool and maintenance equipment repair, and preparation of radioactive material for shipment and disposal. This paper discusses hot cell facility functions, requirements, and design issues and techniques. Suggested solutions and examples are given.

  11. Hot cell facility design for large fusion devices

    NASA Astrophysics Data System (ADS)

    Barrett, R. J.; Bussell, G. T.

    Large hot cell facilities will be necessary to support the operation of large fusion devices. The supporting hot cells will be needed to serve a variety of different functions and tasks, which include reactor component maintenance, tool and maintenance equipment repair, and preparation of radioactive material for shipment and disposal. This paper discusses hot cell facility functions, requirements, and design issues and techniques. Suggested solutions and examples are given.

  12. Plasmon-induced hot carriers in metallic nanoparticles.

    PubMed

    Manjavacas, Alejandro; Liu, Jun G; Kulkarni, Vikram; Nordlander, Peter

    2014-08-26

    Plasmon-induced hot carrier formation is attracting an increasing research interest due to its potential for applications in photocatalysis, photodetection and solar energy harvesting. However, despite very significant experimental effort, a comprehensive theoretical description of the hot carrier generation process is still missing. In this work we develop a theoretical model for the plasmon-induced hot carrier process and apply it to spherical silver nanoparticles and nanoshells. In this model, the conduction electrons of the metal are described as free particles in a finite spherical potential well, and the plasmon-induced hot carrier production is calculated using Fermis golden rule. We show that the inclusion of many-body interactions has only a minor influence on the results. Using the model we calculate the rate of hot carrier generation, finding that it closely follows the spectral profile of the plasmon. Our analysis reveals that particle size and hot carrier lifetime play a central role in determining both the production rate and the energy distribution of the hot carriers. Specifically, larger nanoparticle sizes and shorter lifetimes result in higher carrier production rates but smaller energies, and vice versa. We characterize the efficiency of the hot carrier generation process by introducing a figure of merit that measures the number of high energy carriers generated per plasmon. Furthermore, we analyze the spatial distribution and directionality of these excitations. The results presented here contribute to the basic understanding of plasmon-induced hot carrier generation and provide insight for optimization of the process. PMID:24960573

  13. Diving company claims record in gulf hot tap

    SciTech Connect

    Not Available

    1992-03-16

    This paper reports that the deepest pipeline hot tap in the U.S. Gulf of Mexico, and possibly the world, was recently accomplished in 630 ft of seawater, according to Offshore Petroleum Divers Inc. (OPD) which carried out the dive. The hot tap, in South Pass Block 50,. connected a newly constructed BP Exploration 8-in. pipeline to an operational 10-in. oil pipeline for Chevron Pipeline Co. Hot taps enable operators to attach an ancillary pipeline to an operational or hot pipeline. The procedure avoids construction of additional pipelines to a production platform.

  14. Hot zones evolution and dynamics in heterogeneous catalytic systems.

    PubMed

    Luss, D.; Marwaha, B.

    2002-03-01

    Stationary and complex moving hot regions formed for temperatures close to the extinction temperature of uniformly ignited states of several catalytic systems, such as thin rings and hollow cylinders, a thin radial flow reactor (RFR) and a shallow packed bed. IR imaging revealed that the hot and cold regions (temperature difference of the order of 100 degrees C) were separated by a sharp (about 3 mm wide) temperature front. The transition from the branch of uniformly ignited to the states with a hot region was usually supercritical. In some experiments a disjoint branch of states with hot regions existed and two qualitatively different states with hot zones existed under the same operating conditions. A very intricate periodic motion of a hot zone was observed in a shallow packed bed reactor. For example, Fig. 16 shows a hot zone which splits and later coalesces several times during the long (14 h) period. Hot pulse motions were observed on a single catalytic pellet. These were caused by global coupling between the surface reaction rate and the ambient reactant concentration and the inherent nonuniformity of the catalytic activity. It is not yet clear what rate processes generate the transversal hot zones in uniform packed bed reactors. (c) 2002 American Institute of Physics. PMID:12779545

  15. Radiative recombination of hot carriers in narrow-gap semiconductors

    SciTech Connect

    Pavlov, N. V.; Zegrya, G. G.

    2012-01-15

    The mechanism of the radiative recombination of hot carriers in narrow-gap semiconductors is analyzed using the example of indium antimonide. It is shown that the CHCC Auger recombination process may lead to pronounced carrier heating at high excitation levels. The distribution functions and concentrations of hot carriers are determined. The radiative recombination rate of hot carriers and the radiation gain coefficient are calculated in terms of the Kane model. It is demonstrated that the radiative recombination of hot carriers will make a substantial contribution to the total radiative recombination rate at high carrier concentrations.

  16. Flute-interchange stability in a hot electron plasma

    SciTech Connect

    Dominguez, R.R.

    1980-01-01

    Several topics in the kinetic stability theory of flute-interchange modes in a hot electron plasma are discussed. The stability analysis of the hot-electron, curvature-driven flute-interchange mode, previously performed in a slab geometry, is extended to a cylindrical plasma. The cold electron concentration necessary for stability differs substantially from previous criteria. The inclusion of a finite temperature background plasma in the stability analysis results in an ion curvature-driven flute-interchange mode which may be stabilized by either hot-electron diamagnetic effects, hot-electron plasma density, or finite (ion) Larmor radius effects.

  17. The Hot Big Bang:. Physics and Cosmology

    NASA Astrophysics Data System (ADS)

    Partridge, R. B.

    2002-12-01

    The discovery of the cosmic microwave background 36 years ago established the Hot Big Bang model, and demonstrated convincingly that early epochs in the history of the Universe were very different from the present. Studies of the cosmic microwave background (CMB) have also turned cosmology into a real physical science: CMB measurements can be used to shed light on areas of fundamental physics (the half-life of the neutron; the number of neutrino families; the energy density of the vacuum) as well as to refine our understanding of the evolution of the Universe. I will review the transition to physical cosmology over the past 3-4 decades, with special emphasis on the physics underlying anisotropies in the angular distribution of the CMB. These promise to refine our understanding of fundamental physics as well as to provide quite precise values of key cosmological parameters. CMB observations already available, for instance, suggest that the Universe has a flat spatial geometry, in keeping with predictions of the inflationary variant of Hot Big Bang cosmology. Improved observations will help refine values for the rate of expansion of the Universe and set limits on the vacuum energy density, baryon density and early background of gravity waves, among other results.

  18. Extended emission in three luminous hot cores

    NASA Astrophysics Data System (ADS)

    Hieret, Carolin Olivia; Menten, Karl; Schilke, Peter; Longmore, Steven; Wyrowski, Friedrich

    2007-10-01

    When studying the formation of massive stars, it is not only important to know about the innermost densest and hottest regions, but also about the molecular environment of the clouds in which the hot cores are located. We recently observed three hot cores with the ATCA in 3mm continuum and H13CN(1-0) line emission, but our APEX H13CN(4-3) maps let us expect that we probably missed extended emission even with the more compact ATCA configuration. Since our previous 3mm observation with the ATCA were insensitive to larger structures, we now request zero spacings from MOPRA to study extended emission in the high mass star forming regions 12326-6245, 16060-5146 and 16065-5158. A particular problem for our analysis of the ATCA data without additional zero spacings poses 16060-5146, where we see H13CN(1-0) in absorption against two cores, which could either be real or the result of the missing zero spacings. Therefore we propose to map a 4 arcminute region around each source with the MOPS spectrometer in narrowband mode. This work is part of C. Hieret's PhD thesis.

  19. Hot water can freeze faster than cold?!?

    E-print Network

    Monwhea Jeng

    2005-12-29

    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 likely to burst than cold water pipes are also described.

  20. Modelling the spectroscopic behaviour of hot molecules

    NASA Astrophysics Data System (ADS)

    Tennyson, Jonathan

    2010-05-01

    At elevated temperatures the molecules absorb and emit light in a very complicated fashion which is hard to characterise on the basis of laboraroty measurement. Computed line lists of molecule transitions therefore provide a vital input for models of hot atmospheres. I will describe the calculation and use of such line lists including the BT2 water line list [1], which contains some 500 million distinct rotation-vibration transitions. This linelist proved crucial in the detection of water in extrasolar planet HD189733b and has been used extensively in atmospheric modelling. Illustrations will be given at the meeting. A new linelist for the ammonia molecule has just been completed [2] which shows that standard compilations for this molecule need to be improved. Progress on a more extensive linelist for hot ammonia and linelists for other molecules will be discussed at the meeting. [1] R.J. Barber, J. Tennyson, G.J. Harris and R.N. Tolchenov, Mon. Not. R. Astr. Soc., 368, 1087-1094 (2006) [2] S.N. Yurchenko, R.J. Barber, A. Yachmenev, W. Theil, P. Jensen and J. Tennyson, J. Phys. Chem. A, 113, 11845-11855 (2009).

  1. Hot Dog and Butterfly, Nereidum Montes

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Some of the pictures returned from Mars by the Mars Orbiter Camera (MOC) onboard the Mars Global Surveyor (MGS) spacecraft show features that--at a glance--resemble familiar, non-geological objects on Earth. For example, the picture above at the left shows several low, relatively flat-topped hills (mesas) on the floor of a broad valley among the mountains of the Nereidum Montes region, northeast of Argyre Planitia. One of the mesas seen here looks like half of a butterfly (upper subframe on right). Another hill looks something like a snail or a hot dog wrapped and baked in a croissant roll (lower subframe on right). These mesas were formed by natural processes and are most likely the eroded remnants of a formerly more extensive layer of bedrock. In the frame on the left, illumination is from the upper left and the scene covers an area 2.7 km (1.7 miles) wide by 6.8 km (4.2 miles) high. The 'butterfly' is about 800 meters (875 yards) in length and the 'hot dog' is about 1 km (0.62 miles) long.

    Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  2. Experimental Line Lists of Hot Methane

    NASA Astrophysics Data System (ADS)

    Hargreaves, Robert J.; Bernath, Peter F.; Bailey, Jeremy; Dulick, Michael

    2015-06-01

    Line lists of CH4 at high temperatures (up to 900C) have been produced between 2500 and 5000 cm-1. This spectral range contains the pentad and octad regions, and includes numerous fundamental, overtone and hot bands. Our method makes use of a quartz sample cell that is heated by a tube furnace. Four spectra are then recorded at each temperature using a Fourier transform infrared spectrometer at high resolution (0.02 cm-1). By combining these four spectra at each temperature, the emission and absorption from the cell and molecules are accounted for, and we obtain the true transmission spectrum of hot CH4. Analysis of this series of spectra enables the production of line lists that include positions, intensities and empirical lower state energies. We also compare our line lists to the best available theoretical line lists at high temperatures. Whilst our experimental line lists contain fewer lines than theoretical line lists, we are able to demonstrate the quality of our observed spectra by considering our observations as absorption cross sections. This is important at elevated temperatures, when numerous blended lines appear as a continuum.

  3. HOT DEBRIS DUST AROUND HD 106797

    SciTech Connect

    Fujiwara, Hideaki; Onaka, Takashi; Yamashita, Takuya; Ishihara, Daisuke; Kataza, Hirokazu; Ootsubo, Takafumi; Murakami, Hiroshi; Nakagawa, Takao; Hirao, Takanori; Enya, Keigo; Fukagawa, Misato; Marshall, Jonathan P.; White, Glenn J.

    2009-04-10

    Photometry of the A0 V main-sequence star HD 106797 with AKARI and Gemini/T-ReCS is used to detect excess emission over the expected stellar photospheric emission between 10 and 20 {mu}m, which is best attributed to hot circumstellar debris dust surrounding the star. The temperature of the debris dust is derived as T {sub d} {approx} 190 K by assuming that the excess emission is approximated by a single temperature blackbody. The derived temperature suggests that the inner radius of the debris disk is {approx}14 AU. The fractional luminosity of the debris disk is 1000 times brighter than that of our own zodiacal cloud. The existence of such a large amount of hot dust around HD 106797 cannot be accounted for by a simple model of the steady state evolution of a debris disk due to collisions, and it is likely that transient events play a significant role. Our data also show a narrow spectral feature between 11 and 12 {mu}m attributable to crystalline silicates, suggesting that dust heating has occurred during the formation and evolution of the debris disk of HD 106797.

  4. Deep drilling technology for hot crystalline rock

    SciTech Connect

    Rowley, J.C.

    1984-01-01

    The development of Hot Dry Rock (HDR) geothermal systems at the Fenton Hill, New Mexico site has required the drilling of four deep boreholes into hot, Precambrian granitic and metamorphic rocks. Thermal gradient holes, four observation wells 200 m (600 ft) deep, and an exploration core hole 800 m (2400 ft) deep guided the siting of the four deep boreholes. Results derived from the exploration core hole, GT-1 (Granite Test No. 1), were especially important in providing core from the granitic rock, and establishing the conductive thermal gradient and heat flow for the granitic basement rocks. Essential stratigraphic data and lost drilling-fluid zones were identified for the volcanic and sedimentary rocks above the contact with the crystalline basement. Using this information drilling strategies and well designs were then devised for the planning of the deeper wells. The four deep wells were drilled in pairs, the shallowest were planned and drilled to depths of 3 km in 1975 at a bottom-hole temperature of nearly 200/sup 0/C. These boreholes were followed by a pair of wells, completed in 1981, the deepest of which penetrated the Precambrian basement to a vertical depth of 4.39 km at a temperature of 320/sup 0/C.

  5. THz Hot-Electron Photon Counter

    NASA Technical Reports Server (NTRS)

    Karasik, Boris S.; Sergeev, Andrei V.

    2004-01-01

    We present a concept for the hot-electron transition-edge sensor capable of counting THz photons. The main need for such a sensor is a spectroscopy on future space telescopes where a background limited NEP approx. 10(exp -20) W/H(exp 1/2) is expected at around 1 THz. Under these conditions, the rate of photon arrival is very low and any currently imaginable detector with sufficient sensitivity will operate in the photon counting mode. The Hot-Electron Photon Counter based on a submicron-size Ti bridge has a very low heat capacity which provides a high enough energy resolution (approx.140 GHz) at 0.3 K. With the sensor time constant of a few microseconds, the dynamic range would be approx. 30 dB. The sensor couples to radiation via a planar antenna and is read by a SQUID amplifier or by a 1-bit RSFQ ADC. A compact array of the antenna-coupled counters can be fabricated on a silicon wafer without membranes.

  6. Hot Cell Window Shielding Analysis Using MCNP

    SciTech Connect

    Chad L. Pope; Wade W. Scates; J. Todd Taylor

    2009-05-01

    The Idaho National Laboratory Materials and Fuels Complex nuclear facilities are undergoing a documented safety analysis upgrade. In conjunction with the upgrade effort, shielding analysis of the Fuel Conditioning Facility (FCF) hot cell windows has been conducted. This paper describes the shielding analysis methodology. Each 4-ft thick window uses nine glass slabs, an oil film between the slabs, numerous steel plates, and packed lead wool. Operations in the hot cell center on used nuclear fuel (UNF) processing. Prior to the shielding analysis, shield testing with a gamma ray source was conducted, and the windows were found to be very effective gamma shields. Despite these results, because the glass contained significant amounts of lead and little neutron absorbing material, some doubt lingered regarding the effectiveness of the windows in neutron shielding situations, such as during an accidental criticality. MCNP was selected as an analysis tool because it could model complicated geometry, and it could track gamma and neutron radiation. A bounding criticality source was developed based on the composition of the UNF. Additionally, a bounding gamma source was developed based on the fission product content of the UNF. Modeling the windows required field inspections and detailed examination of drawings and material specifications. Consistent with the shield testing results, MCNP results demonstrated that the shielding was very effective with respect to gamma radiation, and in addition, the analysis demonstrated that the shielding was also very effective during an accidental criticality.

  7. Detecting the warm-hot intergalactic medium

    NASA Astrophysics Data System (ADS)

    den Herder, Jan-Willem; Paerels, Frits B. S.; Rasmussen, Andrew; Bruijn, Marcel; Hoevers, Henk; Kaastra, Jelle S.; Kahn, Steven M.; de Korte, Piet A.; Scharf, Caleb

    2004-10-01

    A very significant fraction of the baryonic matter in the local universe is predicted to form a Warm Hot Intergalactic Medium (WHIM) of very low density, moderately hot gas, tracing the cosmic web. Its X-ray emission is dominated by metal features, but is weak (< 0.01 photons/cm2/s/sr) and potentially hard to separate from the galactic component. However, a mission capable of directly mapping this component of the large scale structure of the universe, via a small number of well chosen emission lines, is now within reach due to recent improvements in cryogenic X-ray detector energy resolution. To map the WHIM, the energy resolution and grasp are optimized. A number of missions have been proposed to map the missing baryons including MBE (US/SMEX program) and DIOS (Japan). The design of the mirror and detector have still room for improvements which will be discussed. With these improvements it is feasible to map a 10 x 10 degree area of the sky in 2 years out to z = 0.2 with sufficient sensitivity to directly detect WHIM structure, such as filaments connecting clusters of galaxies. This structure is predicted by the current Cold Dark Matter paradigm which thus far appears to provide a good description of the distribution of matter as traced by galaxies.

  8. ATMOSPHERES OF HOT SUPER-EARTHS

    SciTech Connect

    Castan, Thibaut; Menou, Kristen

    2011-12-20

    Hot super-Earths likely possess minimal atmospheres established through vapor saturation equilibrium with the ground. We solve the hydrodynamics of these tenuous atmospheres at the surface of CoRot-7b, Kepler-10b, and 55 Cnc-e, including idealized treatments of magnetic drag and ohmic dissipation. We find that atmospheric pressures remain close to their local saturation values in all cases. Despite the emergence of strongly supersonic winds which carry sublimating mass away from the substellar point, the atmospheres do not extend much beyond the day-night terminators. Ground temperatures, which determine the planetary thermal (infrared) signature, are largely unaffected by exchanges with the atmosphere and thus follow the effective irradiation pattern. Atmospheric temperatures, however, which control cloud condensation and thus albedo properties, can deviate substantially from the irradiation pattern. Magnetic drag and ohmic dissipation can also strongly impact the atmospheric behavior, depending on atmospheric composition and the planetary magnetic field strength. We conclude that hot super-Earths could exhibit interesting signatures in reflection (and possibly in emission) which would trace a combination of their ground, atmospheric, and magnetic properties.

  9. Geothermal Exploration in Hot Springs, Montana

    SciTech Connect

    Toby McIntosh, Jackola Engineering

    2012-09-26

    The project involves drilling deeper in the Camp Aqua well dri lled in June 1982 as part of an effort to develop an ethanol plant. The purpose of the current drill ing effort is to determine if water at or above 165???????????????????????????????°F exists for the use in low temperature resource power generation. Previous geothermal resource study efforts in and around Hot Springs , MT and the Camp Aqua area (NE of Hot Springs) have been conducted through the years. A confined gravel aquifer exists in deep alluvium overlain by approximately 250???????????????¢???????????????????????????????? of si lt and c lay deposits from Glacial Lake Missoula. This gravel aquifer overlies a deeper bedrock aquifer. In the Camp Aqua area several wel l s exist in the gravel aquifer which receives hot water f rom bedrock fractures beneath the area. Prior to this exploration, one known well in the Camp Aqua area penetrated into the bedrock without success in intersecting fractures transporting hot geothermal water. The exploration associated with this project adds to the physical knowledge database of the Camp Aqua area. The dri l l ing effort provides additional subsurface information that can be used to gain a better understanding of the bedrock formation that i s leaking hot geothermal water into an otherwise cold water aquifer. The exi s t ing well used for the explorat ion is located within the ???????????????¢????????????????????????????????center???????????????¢??????????????????????????????? of the hottest water within the gravel aquifer. This lent i t sel f as a logical and economical location to continue the exploration within the existing well. Faced with budget constraints due to unanticipated costs, changing dril l ing techniques stretched the limited project resources to maximize the overa l l well depth which f e l l short of original project goals. The project goal of finding 165???????????????????????????????°F or hotter water was not achieved; however the project provides additional information and understanding of the Camp Aqua area that could prove valuable in future exploration efforts

  10. The menopausal hot flush--anything new?

    PubMed

    Sturdee, David W

    2008-05-20

    Although the hot flush is generally recognised by women and the medical profession as the most characteristic and often a very distressing symptom of the climacteric, it remains an enigma. The physiological changes associated with the hot flush are different from any other flushing condition, with an increased peripheral blood flow, increased heart rate and in particular a decrease in galvanic skin resistance, which is unique to the flush. Flushing occurs as a result of disturbance of the temperature regulating mechanism situated in the hypothalamus, and probably a reduction in the thermoneutral zone, within which fluctuations of basal body temperature do not provoke compensatory vascular responses. Many factors have been implicated, including hormone releasing factors, gonadotrophins and neurohumorals. However, the role of oestrogen is critical and the clinical value of oestrogen therapy is well established and has been confirmed by a Cochrane review. Nevertheless, the precise mechanism by which reduced circulating levels of oestrogen are involved in causing the flush has not yet been established. Priming with oestrogen seems to be an essential pre-requisite for flushing, as young women with ovarian dysgenesis and very low circulating levels of oestrogen never have hot flushes unless they are given oestrogen replacement therapy, which is later discontinued. Oestrogen antagonist activity by selective oestrogen receptor modulators such as tamoxifen and raloxifene can also cause flushing. A link with gonadotrophins is demonstrated by a temporal association of flushes with the pulsatile release of luteinising hormone (LH). However, if LH pulses are eliminated by GnRH analogue, the frequency of flushing is not altered, which confirms that LH is merely associated with the flush rather than being causative. It is probable that the flush is initiated by a supra-pituitary mechanism which is influenced by the hypothalamic factors responsible for pulsatile LH release. A variety of chemical pathways have been proposed involving serotonin, noradrenalin and dopamine. Trials of drugs that selectively inhibit the re-uptake of serotonin and noradrenalin have shown some beneficial effects, as also has gabapentin, but often the results have been disappointing, and certainly less than the response seen with oestrogen or tibolone. The prevalence of hot flushes varies considerably around the world and is less in the Far East than in the west. Differences in diet and in particular the intake of phytoestrogens has been implicated and many studies have tried to establish whether dietary supplementation with phytoestrogens might be a suitable alternative to conventional hormone replacement therapy (HRT). So far, the results are disappointing. Other lifestyle measures such as avoiding alcohol, caffeine and spicy foods, keeping the core body temperature cool, paced respiration, taking exercise and even acupuncture may help. Hot flushes remain a major cause of reduced quality of life in a large proportion of menopausal women, but perhaps because they are not fatal and are usually self-limiting, there has been rather limited research or clinical interest. However, for the increasing number of women being treated with tamoxifen for breast cancer, and for whom oestrogen will usually be contra-indicated or unsuitable, there is an urgent need to identify the underlying mechanism so that appropriate, specific and safe non-oestrogen therapy can be offered to improve their quality of life. PMID:18384981

  11. Getting into hot water Problematizing hot water service demand: The case of Old Cairo

    NASA Astrophysics Data System (ADS)

    Culhane, Thomas Henry

    This dissertation analyzes hot water demand and service infrastructure in two neighboring but culturally distinct communities of the urban poor in the inner-city area of central Cairo. The communities are the Historic Islamic Cairo neighborhood of Darb Al Ahmar at the foot of Al-Azhar park, and the Zurayib neighborhood of Manshiyat Nasser where the Coptic Zabaleen Recyclers live. The study focuses on the demand side of the hot water issue and involves consideration of built-environment infrastructures providing piped water, electricity, bottled gas, sewage, and the support structures (wiring and plumbing) for consumer durables (appliances such as hot water heaters, stoves, refrigerators, air conditioners) as well as water pumps and water storage tanks. The study asks the questions "How do poor communities in Cairo value hot water" and "How do cost, infrastructure and cultural preferences affect which attributes of hot water service are most highly preferred?". To answer these questions household surveys based primarily on the World Bank LSMS modules were administered by professional survey teams from Darb Al Ahmar's Aga Khan Trust for Culture and the Zabaleen's local NGO "Spirit of Youth" in their adjacent conununities in and surrounding historic Cairo. In total 463 valid surveys were collected, (231 from Darb Al Ahmar, 232 from the Zabaleen). The surveys included a contingent valuation question to explore Willingness to Pay for improved hot water service; the surveys queried household assets as proxies for income. The dissertation's findings reveal that one quarter of the residents of Darb Al Ahmar and two-thirds of the residents of Manshiyet Nasser's Zabaleen lack conventional water heating service. Instead they employ various types of stoves and self-built contraptions to heat water, usually incurring considerable risk and opportunity costs. However the thesis explores the notion that this is rational "satisficing" behavior; despite the shortcomings of such self-help strategies, the greater flexibility they provide may lead to superior long-term outcomes in a time of uncertain and rising energy and commodities prices and an increasing availability of new, less expensive, increasingly modular, and more efficient technologies that are easier for individual households to install and use, especially if the State or non-governmental institutions can provide implementation support. The descriptive statistics and the multivariate models obtained through the analysis of the data gathered in the surveys show that while purchase price and running costs for dedicated water heating systems are considerations for families desiring hot water, the infrastructural demands of modern appliances vis a vis a consumer's given built environment and the historical/cultural legacy of the consumer's past hot water choices and practices are often more important determinants of the kind of water heating used and desired today. Our study shows, for example, that while higher income is associated with owning a water heater in a simple model with few explanatory variables (Model 3) it's significance disappears when controlling for Ethnicity and infrastructural elements (Model 1). This might suggest that while within communities there is a point at which making more money implies a shift to consumer "modernity", overall the availability of more money in these neighborhoods as a whole doesn't guarantee that the utility promised by modern appliances will be realized. A similar point can be made about formal education levels, which appear insignificant in our models. Policy that aimed merely at sending more kids to school would not address the great deficiencies that many Egyptian schools are noted for. There is no guarantee that merely expanding Egypt's "universal education" policy to include children who have fallen through the cracks would help increase consumer awareness or consumer choice. On the other hand both water availability and presence of hot water pipes, as proxies for assets in

  12. A Pilot Study of Integral Yoga for Menopausal Hot Flashes

    PubMed Central

    Avis, Nancy E.; Legault, Claudine; Russell, Gregory; Weaver, Kathryn; Danhauer, Suzanne C.

    2013-01-01

    Objective To obtain preliminary data on the efficacy of yoga for reducing self-reported menopausal hot flashes in a randomized study including an attention control group. Methods We randomized 54 women late perimenopausal (212 months of amenorrhea) and postmenopausal women (12 or more months of amenorrhea), aged 4558 years, with at least 4 hot flashes per day on average, for at least 4 weeks, to one of three groups: yoga, health and wellness education (HW) classes, and a wait list (WL) control group. Yoga and HW classes consisted of weekly 90 minute classes for 10 weeks. All women completed daily hot flash diaries throughout the trial (10 weeks) to track frequency and severity of hot flashes. The mean hot flash index score is based on the number of mild, moderate, severe and very severe hot flashes. Results Hot flash frequency declined significantly over time for all three groups with the strongest decline during the first week. There was no overall significant difference in hot flash frequency decrease over time by treatment groups, but the yoga and HW groups followed similar patterns and both showed greater decreases than the WL group. By week 10, women in the yoga group reported a decrease of approximately 66% in hot flash frequency, 63% in HW, and 36% in the WL group. The hot flash index showed a similar pattern. Conclusions Results suggest that yoga can serve as a behavioral option for reducing hot flashes, but they also suggest that yoga may not offer any advantage over other types of interventions. PMID:24473534

  13. AIM cryocooler developments for HOT detectors

    NASA Astrophysics Data System (ADS)

    Rhlich, I.; Mai, M.; Withopf, A.; Rosenhagen, C.

    2014-06-01

    Significantly increased FPA temperatures for both Mid Wave and Long Wave IR detectors, i.e. HOT detectors, which have been developed in recent years are now leaving the development phase and are entering real application. HOT detectors allowing to push size weight and power (SWaP) of Integrated Detectors Cooler Assemblies (IDCA's) to a new level. Key component mainly driving achievable weight, volume and power consumption is the cryocooler. AIM cryocooler developments are focused on compact, lightweight linear cryocoolers driven by compact and high efficient digital cooler drive electronics (DCE) to also achieve highest MTTF targets. This technology is using moving magnet driving mechanisms and dual or single piston compressors. Whereas SX030 which was presented at SPIE in 2012 consuming less 3 WDC to operate a typical IDCA at 140K, next smaller cooler SX020 is designed to provide sufficient cooling power at detector temperature above 160K. The cooler weight of less than 200g and a total compressor length of 60mm makes it an ideal solution for all applications with limited weight and power budget, like in handheld applications. For operating a typical 640x512, 15?m MW IR detector the power consumption will be less than 1.5WDC. MTTF for the cooler will be in excess of 30,000h and thus achieving low maintenance cost also in 24/7 applications. The SX020 compressor is based on a single piston design with integrated passive balancer in a new design achieves very low exported vibration in the order of 100mN in the compressor axis. AIM is using a modular approach, allowing the chose between 5 different compressor types for one common Stirling expander. The 6mm expander with a total length of 74mm is now available in a new design that fits into standard dewar bores originally designed for rotary coolers. Also available is a 9mm coldfinger in both versions. In development is an ultra-short expander with around 35mm total length to achieve highest compactness. Technical solutions and key performance data for AIM's HOT cryocoolers will be presented.

  14. Electrically tunable hot-silicon terahertz attenuator

    SciTech Connect

    Wang, Minjie; Vajtai, Robert; Ajayan, Pulickel M.; Kono, Junichiro

    2014-10-06

    We have developed a continuously tunable, broadband terahertz attenuator with a transmission tuning range greater than 10{sup 3}. Attenuation tuning is achieved electrically, by simply changing the DC voltage applied to a heating wire attached to a bulk silicon wafer, which controls its temperature between room temperature and ?550?K, with the corresponding free-carrier density adjusted between ?10{sup 11?}cm{sup ?3} and ?10{sup 17?}cm{sup ?3}. This hot-silicon-based terahertz attenuator works most effectively at 450550?K (corresponding to a DC voltage variation of only ?7?V) and completely shields terahertz radiation above 550?K in a frequency range of 0.12.5 THz. Both intrinsic and doped silicon wafers were tested and demonstrated to work well as a continuously tunable attenuator. All behaviors can be understood quantitatively via the free-carrier Drude model taking into account thermally activated intrinsic carriers.

  15. Primordial Black Holes and Hot Matter

    E-print Network

    Joseph I Kapusta

    2001-04-19

    Microscopic black holes explode with their temperature varying inversely as their mass. Such explosions would lead to the highest temperatures in the present universe, all the way to the Planck energy. The possibility that a quasi-stationary shell of hot matter surrounds these black holes has recently been proposed and studied with relativistic Boltzmann transport equations and with relativistic viscous fluid dynamics. For example, a black hole with a mass of 10$^{10}$ g has a Hawking temperature of 1 TeV, a Schwarszchild radius of 1.6$\\times10^{-5}$ fm, a luminosity of 7$\\times10^{27}$ erg/s, and has less than 8 minutes to live. It is an outstanding theoretical challenge to describe the conditions exterior to such microscopic black holes and a great challenge to finally detect them in the new millennium.

  16. Power control for hot gas engines

    NASA Technical Reports Server (NTRS)

    Macglashan, W. F. (inventor)

    1980-01-01

    A hot gas engine in which the expander piston of the engine is connected to an expander crankshaft. A displacer piston of the engine is connected to a separate displacer crankshaft which may or may not be coaxial with the expander crankshaft. A phase angle control mechanism used as a power control for changing the phase angle between the expander and displacer crankshaft is located between the two crankshafts. The phase angle control mechanism comprises a differential type mechanism comprised of a pair of gears, as for example, bevel gears, one of which is connected to one end of the expander crankshaft and the other of which is connected to the opposite end of the displacer crankshaft. A mating bevel gear is disposed in meshing engagement with the first two level gears to provide a phase angle control between the two crankshafts. Other forms of differential mechanisms may be used including conventional spur gears connected in a differential type arrangement.

  17. HotSpotter? Neutron/Gamma Detector

    SciTech Connect

    Bell, Z.W.

    2003-04-01

    The HotSpotter{trademark} Neutron/Gamma Detector combines in a single detecting module high sensitivity to gamma rays up to 3 MeV and sensitivity to neutrons. Using a 15 mm cubic CdWO{sub 4} (cadmium tungstate) crystal mounted on a 25 mm photomultiplier, the instrument realizes a factor of 5 increased photopeak efficiency over NaI(Tl) at 1 MeV, and a factor of 2 improvement over CsI(Tl). The addition of a 0.5 mm layer of {sup 10}B- impregnated epoxy covering the crystal provides neutron sensitivity without sacrificing gamma ray spectroscopic characteristics. Neutrons are detected by the presence of the 478 keV gamma from the {sup 10}B(n,{alpha}){sup 7}Li* reaction. In this paper, we describe the electronics and software of the instrument, and some of its characteristics.

  18. Telescopic nanotube device for hot nanolithography

    DOEpatents

    Popescu, Adrian; Woods, Lilia M

    2014-12-30

    A device for maintaining a constant tip-surface distance for producing nanolithography patterns on a surface using a telescopic nanotube for hot nanolithography. An outer nanotube is attached to an AFM cantilever opposite a support end. An inner nanotube is telescopically disposed within the outer nanotube. The tip of the inner nanotube is heated to a sufficiently high temperature and brought in the vicinity of the surface. Heat is transmitted to the surface for thermal imprinting. Because the inner tube moves telescopically along the outer nanotube axis, a tip-surface distance is maintained constant due to the vdW force interaction, which in turn eliminates the need of an active feedback loop.

  19. MAGNETICALLY CONTROLLED CIRCULATION ON HOT EXTRASOLAR PLANETS

    SciTech Connect

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

    2013-10-10

    Through the process of thermal ionization, intense stellar irradiation renders hot Jupiter atmospheres electrically conductive. Simultaneously, lateral variability in the irradiation drives the global circulation with peak wind speeds of the order of ?km s{sup 1}. In turn, the interactions between the atmospheric flows and the background magnetic field give rise to Lorentz forces that can act to perturb the flow away from its purely hydrodynamical counterpart. Using analytical theory and numerical simulations, we show here that significant deviations away from axisymmetric circulation are unstable in presence of a non-negligible axisymmetric magnetic field. Specifically, our results suggest that dayside-to-nightside flows, often obtained within the context of three-dimensional circulation models, only exist on objects with anomalously low magnetic fields, while the majority of highly irradiated exoplanetary atmospheres are entirely dominated by zonal jets.

  20. Hot Dry Rock Overview at Los Alamos

    SciTech Connect

    Berger, Michael; Hendron, Robert H.

    1989-03-21

    The Hot Dry Rock (HDR) geothermal energy program is a renewable energy program that can contribute significantly to the nation's balanced and diversified energy mix. Having extracted energy from the first Fenton Hill HDR reservoir for about 400 days, and from the second reservoir for 30 days in a preliminary test, Los Alamos is focusing on the Long Term Flow Test and reservoir studies. Current budget limitations have slowed preparations thus delaying the start date of that test. The test is planned to gather data for more definitive reservoir modeling with energy availability or reservoir lifetime of primary interest. Other salient information will address geochemistry and tracer studies, microseismic response, water requirements and flow impedance which relates directly to pumping power requirements. During this year of ''preparation'' we have made progress in modeling studies, in chemically reactive tracer techniques, in improvements in acoustic or microseismic event analysis.

  1. Hot multiboundary wormholes from bipartite entanglement

    E-print Network

    Donald Marolf; Henry Maxfield; Alex Peach; Simon F. Ross

    2015-07-06

    We analyze the 1+1 CFT states dual to hot (time-symmetric) 2+1 multiboundary AdS wormholes. These are black hole geometries with high local temperature, $n \\ge 1$ asymptotically-AdS$_3$ regions, and arbitrary internal topology. The dual state at $t=0$ is defined on $n$ circles. We show these to be well-described by sewing together tensor networks corresponding to thermofield double states. As a result, the entanglement is spatially localized and bipartite: away from particular boundary points ("vertices") any small connected region $A$ of the boundary CFT is entangled only with another small connected region $B$, where $B$ may lie on a different circle or may be a different part of the same circle. We focus on the pair-of-pants case, from which more general cases may be constructed. We also discuss finite-temperature corrections, where we note that the states involve a code subspace in each circle.

  2. Hot multiboundary wormholes from bipartite entanglement

    E-print Network

    Marolf, Donald; Peach, Alex; Ross, Simon F

    2015-01-01

    We analyze the 1+1 CFT states dual to hot (time-symmetric) 2+1 multiboundary AdS wormholes. These are black hole geometries with high local temperature, $n \\ge 1$ asymptotically-AdS$_3$ regions, and arbitrary internal topology. The dual state at $t=0$ is defined on $n$ circles. We show these to be well-described by sewing together tensor networks corresponding to thermofield double states. As a result, the entanglement is spatially localized and bipartite: away from particular boundary points ("vertices") any small connected region $A$ of the boundary CFT is entangled only with another small connected region $B$, where $B$ may lie on a different circle or may be a different part of the same circle. We focus on the pair-of-pants case, from which more general cases may be constructed. We also discuss finite-temperature corrections, where we note that the states involve a code subspace in each circle.

  3. The Hot Component in 3 New Cvs

    NASA Astrophysics Data System (ADS)

    Szkody, Paula

    We will use IUE time-resolved spectra to pursue the white dwarf/hot component in 3 cataclysmic variables whose unique characteristics were only discovered in the last few months. UU Aqr and PG0134+070 are eclipsing systems with relatively long periods (4-5 hrs). The time-resolved IUE data will identify the white dwarf/inner disk temperature and help to resolve whether high inclination CVs have characteristically lower observed temperatures than others above the period gap. S193 is a peculiar bright new DQ Her-type system in which large amplitude optical pulsations do not appear to maintain extended coherence. Simultaneous IUE and groundbased data will be used to obtain the flux distribution and the amplitude of the UV pulse in order to determine the extent of the disk and the temperature of the pulsed component.

  4. Prototype solar heating and hot water systems

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Alternative approaches to solar heating and hot water system configurations were studied, parametrizing the number and location of the dampers, the number and location of the fans, the interface locations with the furnace, the size and type of subsystems, and operating modes. A two-pass air-heating collector was selected based on efficiency and ease of installation. Also, an energy transport module was designed to compactly contain all the mechanical and electrical control components. System performance calculations were carried out over a heating season for the tentative site location at Tunkhnana, Pa. Results illustrate the effect of collector size, storage capacity, and use of a reflector. Factors which affected system performance include site location, insulative quality of the house, and of the system components. A preliminary system performance specification is given.

  5. Legionella Infection Risk from Domestic Hot Water

    PubMed Central

    Montagna, M. Teresa; Romano-Spica, Vincenzo; Stampi, Serena; Stancanelli, Giovanna; Triassi, Maria; Neglia, Rachele; Marchesi, Isabella; Fantuzzi, Guglielmina; Tat, Daniela; Napoli, Christian; Quaranta, Gianluigi; Laurenti, Patrizia; Leoni, Erica; De Luca, Giovanna; Ossi, Cristina; Moro, Matteo; DAlcal, Gabriella Ribera

    2004-01-01

    We investigated Legionella and Pseudomonas contamination of hot water in a cross-sectional multicentric survey in Italy. Chemical parameters (hardness, free chlorine, and trace elements) were determined. Legionella spp. were detected in 33 (22.6%) and Pseudomonas spp. in 56 (38.4%) of 146 samples. Some factors associated with Legionella contamination were heater type, tank distance and capacity, water plant age, and mineral content. Pseudomonas presence was influenced by water source, hardness, free chlorine, and temperature. Legionella contamination was associated with a centralized heater, distance from the heater point >10 m, and a water plant >10 years old. Furthermore, zinc levels of <20 ?g/L and copper levels of >50 ?g/L appeared to be protective against Legionella colonization. Legionella species and serogroups were differently distributed according to heater type, water temperature, and free chlorine, suggesting that Legionella strains may have a different sensibility and resistance to environmental factors and different ecologic niches. PMID:15109413

  6. Cold chain in a hot climate.

    PubMed

    Guthridge, S L; Miller, N C

    1996-12-01

    We monitored the temperatures of batches of vaccine during transport and storage from a national warehouse to five Northern Territory vaccination clinics. Electronic temperature monitors were placed with vaccines, and were programmed to record the temperature every 30 minutes for up to three months. A diary was attached to each vaccine batch to record each change in location. The temperature recordings covered 8369 hours. There were regular temperature deviations outside the recommended range. In the hot climate of the Northern Territory, freezing is the greatest threat to vaccine potency. Recommendations from the study include: routine use of cold chain indicators, increased vaccine turnover and storage of vaccines within an operational temperature range of 4 to 8 degrees C. Research is needed to investigate the efficacy of heat-stable vaccines when stored at ambient temperatures and in air-conditioned environments. PMID:9117976

  7. Hot evolved stars in massive galaxies

    NASA Astrophysics Data System (ADS)

    Le Cras, Claire; Maraston, Claudia; Thomas, Daniel

    2015-08-01

    It is believed that HB stars and their progeny are responsible for the increase in UV flux found in elliptical galaxies, a phenomenon known as the UV upturn. These stars undergo different evolutionary paths depending on their temperature, with the redder stars evolving as bright P-AGB stars, possibly forming planetary nebulae, before eventually descending the white dwarf cooling curve. We exploit a theoretical model of stellar populations incorporating a hot P-AGB component with a fuel calibrated UV upturn and a system of UV absorption line indices to investigate the redshift at the onset of the UV upturn in massive galaxies. We analyse a large sample of massive galaxy spectra taken from the Sloan Digital Sky Survey (SDSS) -III / Baryon Oscillator Spectroscopic Survey (BOSS). We find up to 47% of our working sample to contain a contribution from old UV bright stars with the majority of old populations contributing up to 30% of the galaxy's stellar mass.

  8. The growing significance of hot intelligences.

    PubMed

    Mayer, John D; Caruso, David R; Panter, A T; Salovey, Peter

    2012-09-01

    Comments on the original article, "Intelligence: New findings and theoretical developments," by R. E. Nisbett, J. Aronson, C. Blair, W. Dickens, J. Flynn, D. F. Halpern, and E. Turkheimer (see record 2011-30298-001). The present authors note that Nisbett et al's review focuses on intelligences that have been topics of research through the 20th century. Since then, however, attention to a new group of intelligences that the present authors refer to as "hot intelligences" has been growing (Mayer, Salovey, & Caruso, 2004). Although Nisbett et al (2012) mentioned potential newcomers to the group of intelligences, such as practical intelligence, the present authors feel that future reviews should consider the burgeoning research in new conceptions of intelligence. Here the authors express a rationale for including a consideration of these newly described intelligences. PMID:22963426

  9. Hot Galactic Arms Point To Vicious Cycle

    NASA Astrophysics Data System (ADS)

    2001-12-01

    NASA's Chandra X-ray Observatory has revealed the aftermath of a titanic explosion that wracked the elliptical galaxy known as NGC 4636. This eruption could be the latest episode in a cycle of violence that is triggered by gas falling into a central massive black hole. Chandra's images of NGC 4636 show spectacular symmetric arms, or arcs, of hot gas extending 25,000 light years into a huge cloud of multimillion-degree-Celsius gas that envelopes the galaxy. At a temperature of 10 million degrees, the arms are 30 percent hotter than the surrounding gas cloud. "The temperature jump, together with the symmetry and scale of the arms, suggests that we are observing the effects of a tremendous outburst that occurred in the center of the galaxy," said Christine Jones of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., lead author of a paper on these observations scheduled for publication in Astrophysical Journal Letters. "The energy of this explosion would be the equivalent of several hundred thousand supernovas." The arms appear to be the leading edges of a galaxy-sized shock wave that is racing outward at 700 kilometers per second, or 1.6 million miles per hour. At this speed, it would take 3 million years for the structures to attain their present size. Cavities detected in the hot gas cloud to the east and west of the center of the galaxy support the shockwave explanation. The authors suggest that the explosion is part of a majestic cosmic feedback process that keeps the galaxy in a state of turmoil. Over a period of a few million years, a hot gas cloud that envelops the stars in the galaxy cools and falls inward toward a central, massive black hole. The feeding of the black hole by the infalling material leads to an explosion that heats the hot gaseous envelope, starting the cycle anew. NGC 4636 NGC 4636 Background Subtracted This feedback cycle may explain one puzzling feature of the galaxy - the lack of a strong radio source of the type that is usually observed in connection with galactic outbursts. "It may be that we are seeing an early stage of the cycle before the radio source has turned on," said team member William Forman also of the Harvard-Smithsonian Center for Astrophysics. "Or, it could be a new type of outburst that is not accompanied by strong radio emission." Other members of the team included Alexey Vikhlinin, Maxim Markevitch, Laurence David, Aryeh Warmflash, all of the CfA, and Paul Nulsen of the University of Wollongong in Australia. Chandra observed NGC 4636, an elliptical galaxy in the constellation Virgo some 50 million light years from Earth, with the Advanced CCD Imaging Spectrometer (ACIS) on Dec. 4-5, 1999 for 11,000 sec, and Jan. 26-27, 2000 for 53,000 seconds as part of a program led by Richard Mushotzky of NASA's Goddard Space Flight Center to study X-ray emission from elliptical galaxies. The ACIS instrument was developed for NASA by Pennsylvania State University, University Park, and Massachusetts Institute of Technology, Cambridge. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program, and TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass.

  10. Cooling Grapple System for FMEF hot cell

    SciTech Connect

    Semmens, L.S.; Frandsen, G.B.; Tome, R.

    1983-01-01

    A Cooling Grapple System was designed and built to handle fuel assemblies within the FMEF hot cell. The variety of functions for which it is designed makes it unique from grapples presently in use. The Cooling Grapple can positively grip and transport assemblies vertically, retrieve assemblies from molten sodium where six inches of grapple tip is submerged, cool 7 kw assemblies in argon, and service an in-cell area of 372 m/sup 2/ (4000 ft/sup 2/). Novel and improved operating and maintenance features were incorporated in the design including a shear pin and mechanical catcher system to prevent overloading the grapple while allowing additional reaction time for crane shutdown.

  11. Legionella infection risk from domestic hot water.

    PubMed

    Borella, Paola; Montagna, M Teresa; Romano-Spica, Vincenzo; Stampi, Serena; Stancanelli, Giovanna; Triassi, Maria; Neglia, Rachele; Marchesi, Isabella; Fantuzzi, Guglielmina; Tat, Daniela; Napoli, Christian; Quaranta, Gianluigi; Laurenti, Patrizia; Leoni, Erica; De Luca, Giovanna; Ossi, Cristina; Moro, Matteo; Ribera D'Alcal, Gabriella

    2004-03-01

    We investigated Legionella and Pseudomonas contamination of hot water in a cross-sectional multicentric survey in Italy. Chemical parameters (hardness, free chlorine, and trace elements) were determined. Legionella spp. were detected in 33 (22.6%) and Pseudomonas spp. in 56 (38.4%) of 146 samples. Some factors associated with Legionella contamination were heater type, tank distance and capacity, water plant age, and mineral content. Pseudomonas presence was influenced by water source, hardness, free chlorine, and temperature. Legionella contamination was associated with a centralized heater, distance from the heater point >10 m, and a water plant >10 years old. Furthermore, zinc levels of <100 microg/L and copper levels of >50 microg/L appeared to be protective against Legionella colonization [corrected]. Legionella species and serogroups were differently distributed according to heater type, water temperature, and free chlorine, suggesting that Legionella strains may have a different sensibility and resistance to environmental factors and different ecologic niches. PMID:15109413

  12. Flowfield visualization for SSME hot gas manifold

    NASA Technical Reports Server (NTRS)

    Roger, Robert P.

    1988-01-01

    The objective of this research, as defined by NASA-Marshall Space Flight Center, was two-fold: (1) to numerically simulate viscous subsonic flow in a proposed elliptical two-duct version of the fuel side Hot Gas Manifold (HGM) for the Space Shuttle Main Engine (SSME), and (2) to provide analytical support for SSME related numerical computational experiments, being performed by the Computational Fluid Dynamics staff in the Aerophysics Division of the Structures and Dynamics Laboratory at NASA-MSFC. Numerical results of HGM were calculations to complement both water flow visualization experiments and air flow visualization experiments and air experiments in two-duct geometries performed at NASA-MSFC and Rocketdyne. In addition, code modification and improvement efforts were to strengthen the CFD capabilities of NASA-MSFC for producing reliable predictions of flow environments within the SSME.

  13. Process for making ceramic hot gas filter

    DOEpatents

    Connolly, Elizabeth Sokolinski (Wilmington, DE); Forsythe, George Daniel (Landenberg, PA); Domanski, Daniel Matthew (New Castle, DE); Chambers, Jeffrey Allen (Hockessin, DE); Rajendran, Govindasamy Paramasivam (Boothwyn, PA)

    2001-01-01

    A ceramic hot-gas candle filter having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during backpulse cleaning and is resistant to chemical degradation at high temperatures.

  14. Pion Properties in a Hot $?N ?$ Gas

    E-print Network

    R. Rapp; J. Wambach

    1993-11-20

    Based on a recent meson-exchange model for the vacuum $\\pi\\pi$ interaction we compute selfconsistently the in-medium $\\pi\\pi$ scattering amplitude and pion selfenergy in a hot $\\pi N\\Delta$ gas. The contributions to the pion selfenergy are calculated from the $\\pi\\pi$ T-matrix as well as from p-wave interaction with nucleons and thermally abundant $\\Delta$'s. Results are presented for two scenarios believed to be realized in the relativistic heavy ion collisions performed at the GSI-SIS and the CERN-SpS. Possible implications for the observed soft pion enhancement at both SIS and SpS are indicated.

  15. Hot Isostatic Pressing of 60-Nitinol

    NASA Technical Reports Server (NTRS)

    Stanford, Malcolm K.

    2015-01-01

    The effects of varying the time, temperature and pressure during consolidation of 60-Nitinol (Nickel Titanium alloy) by hot isostatic pressing (HIP) were examined. Six HIP cycles with a cycle time of either 2 or 20 hours, temperature of 900 or 1000 degrees Centigrade, and a chamber pressure of either 100 or 200 millipascals were used. The cycle representing the shortest cycle time at the highest temperature and pressure (2 hours/1000 degrees Centigrade/200 millipascals) produced material with the highest hardness (720 Vickers Pyramid Number (HV)). A modest increase in average grain size and significant porosity reduction were observed in material subjected to the longest cycle time at the highest temperature, regardless of the pressure applied. The intent of this study is to facilitate the technology transfer involved in the processing of this material.

  16. Thermodynamics of pairing transition in hot nuclei

    E-print Network

    Lang Liu; Zhen-Hua Zhang; Peng-Wei Zhao

    2015-10-09

    The pairing correlations in hot nuclei $^{162}$Dy are investigated in terms of the thermodynamical properties by covariant density functional theory. The heat capacities $C_V$ are evaluated in the canonical ensemble theory and the paring correlations are treated by a shell-model-like approach, in which the particle number is conserved exactly. A S-shaped heat capacity curve, which agrees qualitatively with the experimental data, has been obtained and analyzed in details. It is found that the one-pair-broken states play crucial roles in the appearance of the S shape of the heat capacity curve. Moreover, due to the effect of the particle-number conservation, the pairing gap varies smoothly with the temperature, which indicates a gradual transition from the superfluid to the normal state.

  17. Nonlocal transport in hot plasma. Part I

    SciTech Connect

    Brantov, A. V. Bychenkov, V. Yu.

    2013-09-15

    The problem of describing charged particle transport in hot plasma under the conditions in which the ratio of the electron mean free path to the gradient length is not too small is one of the key problems of plasma physics. However, up to now, there was a deficit of the systematic interpretation of the current state of this problem, which, in most studies, is formulated as the problem of nonlocal transport. In this review, we fill this gap by presenting a self-consistent linear theory of nonlocal transport for small plasma perturbations and an arbitrary collisionality from the classical highly collisional hydrodynamic regime to the collisionless regime. We describe a number of nonlinear transport models and demonstrate the application of the nonclassical transport theory to the solution of some problems of plasma physics, first of all for plasmas produced by nanosecond laser pulses with intensities of 10{sup 13}10{sup 16} W/cm{sup 2}.

  18. Superconducting cuprate heterostructures for hot electron bolometers

    SciTech Connect

    Wen, B.; Yakobov, R.; Vitkalov, S. A.; Sergeev, A.

    2013-11-25

    Transport properties of the resistive state of quasi-two dimensional superconducting heterostructures containing ultrathin La{sub 2?x}Sr{sub x}CuO{sub 4} layers synthesized using molecular beam epitaxy are studied. The electron transport exhibits strong deviation from Ohm's law, ?V??I{sup 3}, with a coefficient ?(T) that correlates with the temperature variation of the resistivity d?/dT. Close to the normal state, analysis of the nonlinear behavior in terms of electron heating yields an electron-phonon thermal conductance per unit area g{sub e?ph}?1 W/K cm{sup 2} at T = 20 K, one-two orders of magnitude smaller than in typical superconductors. This makes superconducting LaSrCuO heterostructures to be attractive candidate for the next generation of hot electron bolometers with greatly improved sensitivity.

  19. Rapidly rotating winds of hot stars

    NASA Astrophysics Data System (ADS)

    Ceniga, M.; Kubt, J.

    The CAK theory is used for a description of a line driven wind of hot stars. We have developed a code using the Newton-Raphson method to obtain a solution of a 1D isothermal line driven wind with rotation. Our calculations confirmed that there exists a "break" value of stellar rotation velocity, for which the wind solution switches to a new one, which yields much denser and slower wind than in the non-rotating case. For this new solution we found a new critical point, which is located far from the stellar photosphere. Close to the star the outflow is 100 times denser at the equator than at the pole. The wind velocity profile is shallower and reaches a terminal velocity of only several hundred km s-1.

  20. Hot multiboundary wormholes from bipartite entanglement

    NASA Astrophysics Data System (ADS)

    Marolf, Donald; Maxfield, Henry; Peach, Alex; Ross, Simon

    2015-11-01

    We analyze the 1+1 CFT states dual to hot (time-symmetric) 2+1 multiboundary AdS wormholes. These are black hole geometries with high local temperature, n?slant 1 asymptotically-AdS3 regions, and arbitrary internal topology. The dual state at t = 0 is defined on n circles. We show these to be well-described by sewing together tensor networks corresponding to thermofield double states. As a result, the entanglement is spatially localized and bipartite: away from particular boundary points (vertices) any small connected region A of the boundary CFT is entangled only with another small connected region B, where B may lie on a different circle or may be a different part of the same circle. We focus on the pair-of-pants case, from which more general cases may be constructed. We also discuss finite-temperature corrections, where we note that the states involve a code subspace in each circle.

  1. Electrical Conductivity of Hot QCD Matter

    E-print Network

    W. Cassing; O. Linnyk; T. Steinert; V. Ozvenchuk

    2013-10-24

    We study the electric conductivity of hot QCD matter at various temperatures T within the off-shell parton-hadron-string dynamics transport approach for interacting partonic, hadronic or mixed systems in a finite box with periodic boundary conditions. The response of the strongly interacting system in equilibrium to an external electric field defines the electric conductivity sigma_0. We find a sizable temperature dependence of the ratio sigma_0/T well in line with calculations in a relaxation time approach for Tc

  2. Magnetic island evolution in hot ion plasmas

    SciTech Connect

    Ishizawa, A.; Nakajima, N.; Waelbroeck, F. L.; Fitzpatrick, R.; Horton, W.

    2012-07-15

    Effects of finite ion temperature on magnetic island evolution are studied by means of numerical simulations of a reduced set of two-fluid equations which include ion as well as electron diamagnetism in slab geometry. The polarization current is found to be almost an order of magnitude larger in hot than in cold ion plasmas, due to the strong shear of ion velocity around the separatrix of the magnetic islands. As a function of the island width, the propagation speed decreases from the electron drift velocity (for islands thinner than the Larmor radius) to values close to the guiding-center velocity (for islands of order 10 times the Larmor radius). In the latter regime, the polarization current is destabilizing (i.e., it drives magnetic island growth). This is in contrast to cold ion plasmas, where the polarization current is generally found to have a healing effect on freely propagating magnetic island.

  3. Hot Cell Facility (HCF) Safety Analysis Report

    SciTech Connect

    MITCHELL,GERRY W.; LONGLEY,SUSAN W.; PHILBIN,JEFFREY S.; MAHN,JEFFREY A.; BERRY,DONALD T.; SCHWERS,NORMAN F.; VANDERBEEK,THOMAS E.; NAEGELI,ROBERT E.

    2000-11-01

    This Safety Analysis Report (SAR) is prepared in compliance with the requirements of DOE Order 5480.23, Nuclear Safety Analysis Reports, and has been written to the format and content guide of DOE-STD-3009-94 Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Safety Analysis Reports. The Hot Cell Facility is a Hazard Category 2 nonreactor nuclear facility, and is operated by Sandia National Laboratories for the Department of Energy. This SAR provides a description of the HCF and its operations, an assessment of the hazards and potential accidents which may occur in the facility. The potential consequences and likelihood of these accidents are analyzed and described. Using the process and criteria described in DOE-STD-3009-94, safety-related structures, systems and components are identified, and the important safety functions of each SSC are described. Additionally, information which describes the safety management programs at SNL are described in ancillary chapters of the SAR.

  4. The HotQCD Equation of State

    SciTech Connect

    Soltz, R A

    2009-08-13

    We present results from recent calculations of the QCD equation of state by the HotQCD Collaboration and review the implications for hydrodynamic modeling. The equation of state of QCD at zero baryon density was calculated on a lattice of dimensions 32{sup 3} x 8 with m{sub l} = 0.1 m{sub s} (corresponding to a pion mass of {approx}220 MeV) using two improved staggered fermion actions, p4 and asqtad. Calculations were performed along lines of constant physics using more than 100M cpu-hours on BG/L supercomputers at LLNL, NYBlue, and SDSC. We present parameterizations of the equation of state suitable for input into hydrodynamics models of heavy ion collisions.

  5. Hot Springs-Garrison Fiber Optic Project

    SciTech Connect

    Not Available

    1994-10-01

    Bonneville Power Administration (BPA) is proposing to upgrade its operational telecommunications system between the Hot Springs Substation and the Garrison Substation using a fiber optic system. The project would primarily involve installing 190 kilometers (120 miles) of fiber optic cable on existing transmission structures and installing new fiber optic equipment in BPA`s substation yards and control houses. BPA prepared an environmental assessment (EA) evaluating the proposed action. This EA was published in October 1994. The EA identifies a number of minor impacts that might occur as a result of the proposed action, as well as some recommended mitigation measures. This Mitigation Action Plan (MAP) identifies specific measures to avoid, minimize, or compensate for impacts identified in the EA.

  6. MENOPAUSAL HOT FLASHES: MECHANISMS, ENDOCRINOLOGY, TREATMENT

    PubMed Central

    Freedman, Robert R.

    2015-01-01

    Hot flashes (HFs) are a rapid and exaggerated heat dissipation response, consisting of profuse sweating, peripheral vasodilation, and feelings of intense, internal heat. They are triggered by small elevations in core body temperature (Tc) acting within a greatly reduced thermoneutral zone, i.e., the Tc region between the upper (sweating) and lower (shivering) thresholds. This is due in part, but not entirely, to estrogen depletion at menopause. Elevated central sympathetic activation, mediated through ?2-adrenergic receptors, is one factor responsible for narrowing of the thermoneutral zone. Procedures which reduce this activation, such as paced respiration and clonidine administration, ameliorate HFs as will peripheral cooling. HFs are responsible for some, but not all, of the sleep disturbance reported during menopause. Recent work calls into question the role of serotonin in HFs. PMID:24012626

  7. Turbine Engine Hot Section Technology (HOST)

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A two-day workshop on the research and plans for turbine engine hot section durability problems was held on October 25 and 26, 1983, at the NASA Lewis Research Center. Presentations were made during six sessions, including structural analysis, fatigue and fracture, surface protective coatings, combustion, turbine heat transfer, and instrumentation, that dealt with the thermal and fluid environment around liners, blades, and vanes, and with material coatings, constitutive behavior, stress-strain response, and life prediction methods for the three components. The principal objective of each session was to disseminate the research results to date, along with future plans, in each of the six areas. Contract and government researchers presented results of their work.

  8. Atmospheric Heat Redistribution on Hot Jupiters

    E-print Network

    Perez-Becker, Daniel

    2013-01-01

    Infrared lightcurves of transiting hot Jupiters present a trend in which the atmospheres of the hottest planets are less efficient at redistributing the stellar energy absorbed on their daysides---and thus have a larger day-night temperature contrast---than colder planets. No predictive atmospheric model has been published that identifies which dynamical mechanisms determine the atmospheric heat redistribution efficiency on tidally locked exoplanets. Here we present a two-layer shallow water model of the atmospheric dynamics on synchronously rotating planets that explains the observed trend. Our model shows that planets with weak friction and weak irradiation exhibit a banded zonal flow with minimal day-night temperature differences, while models with strong irradiation and/or strong friction exhibit a day-night flow pattern with order-unity fractional day-night temperature differences. To interpret the model, we develop a scaling theory that shows that the timescale for gravity waves to propagate horizontall...

  9. The Warm-Hot Intergalactic Medium

    NASA Technical Reports Server (NTRS)

    Hayes, Jeffrey (Technical Monitor)

    2005-01-01

    This grant is associated to a 5-year LTSA grant, on "Studying the Largest Reservoir of Baryons in the Universe: The Warm-Hot Intergalactic Medium". The first year of work within this program has been very rich, and has already produced several important results, as detailed in this paper. Table 2 of our original proposal justification, listed the planned year-by-year program, divided into two sub-fields: (A) the study of the z=0 (or Local Group WHIM) system, and (B) the study of the z greater than 0 (i.e- intervening WHIM) systems. For each of the two sub-fields we had planned to analyze, in the first year, a number of archival (Chandra, XMM and FUSE) and new (if observed) sightlines. Moreover, the plan for the z=0 system included the search for new interesting sightlines. We have accomplished all these tasks.

  10. Hot gas path component cooling system

    SciTech Connect

    Lacy, Benjamin Paul; Bunker, Ronald Scott; Itzel, Gary Michael

    2014-02-18

    A cooling system for a hot gas path component is disclosed. The cooling system may include a component layer and a cover layer. The component layer may include a first inner surface and a second outer surface. The second outer surface may define a plurality of channels. The component layer may further define a plurality of passages extending generally between the first inner surface and the second outer surface. Each of the plurality of channels may be fluidly connected to at least one of the plurality of passages. The cover layer may be situated adjacent the second outer surface of the component layer. The plurality of passages may be configured to flow a cooling medium to the plurality of channels and provide impingement cooling to the cover layer. The plurality of channels may be configured to flow cooling medium therethrough, cooling the cover layer.

  11. Submarine hot springs: Origin of life?

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    The observations of hydrothermal systems along midoceanic spreading centers by the deep-diving submarine, Alvin, have led to numerous geological theories to explain phenomena ranging from heat flow to the formation of massive sulfide deposits. Unusual life in the forms of giant tube worms and mussels (Eos, Dec. 29, 1981) have been found to live along the submarine hot springs in chemically reducing and normally toxic sulfurous environments. Analyses of data over the past year or two have formed the basis of new life-evolution schemes. J.B. Corliss, J.A. Baross, and S.E. Hoffman have outlined a process by which concentrations of methane, ammonia, hydrogen, and metals may have reacted, in several steps, to produce living organisms within or adjacent to submarine hydrothermal systems (Oceanol. Acta, 59-69, 1981).

  12. ATMOSPHERIC CHARACTERIZATION OF THE HOT JUPITER KEPLER-13Ab

    E-print Network

    Shporer, Avi

    Kepler-13Ab (= KOI-13.01) is a unique transiting hot Jupiter. It is one of very few known short-period planets orbiting a hot A-type star, making it one of the hottest planets currently known. The availability of Kepler ...

  13. COLD AND HOT ATOMIC VAPORS: A TESTBED FOR ASTROPHYSICS?

    E-print Network

    Kaiser, Robin

    CHAPTER 5 COLD AND HOT ATOMIC VAPORS: A TESTBED FOR ASTROPHYSICS? Q. Baudouin, W. Guerin and R- scattering of light in hot and cold atomic vapors, random lasing in cold atoms and light-induced long, we would like to point out the possible applications of cold-atom experiments and, more generally

  14. 40 CFR 86.1238-96 - Hot soak test.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Hot soak test. 86.1238-96 Section 86.1238-96...ENGINES (CONTINUED) Evaporative Emission Test Procedures for New Gasoline-Fueled...Vehicles 86.1238-96 Hot soak test. (a)(1) Gasoline- and...

  15. 40 CFR 86.1238-96 - Hot soak test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Hot soak test. 86.1238-96 Section 86.1238-96...ENGINES (CONTINUED) Evaporative Emission Test Procedures for New Gasoline-Fueled...Vehicles 86.1238-96 Hot soak test. (a)(1) Gasoline- and...

  16. 40 CFR 86.1238-96 - Hot soak test.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Hot soak test. 86.1238-96 Section 86.1238-96...ENGINES (CONTINUED) Evaporative Emission Test Procedures for New Gasoline-Fueled...Vehicles 86.1238-96 Hot soak test. (a)(1) Gasoline- and...

  17. 40 CFR 86.1238-96 - Hot soak test.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Hot soak test. 86.1238-96 Section 86.1238-96...ENGINES (CONTINUED) Evaporative Emission Test Procedures for New Gasoline-Fueled...Vehicles 86.1238-96 Hot soak test. (a)(1) Gasoline- and...

  18. Visualizing Cosmological Concepts Using the Analog of a Hot Liquid

    ERIC Educational Resources Information Center

    Yusofi, E.; Mohsenzadeh, M.

    2010-01-01

    We have used the expansion process of hot milk, which has similarities with the cosmic expansion, to facilitate easier and better visualization and teaching of cosmological concepts. Observations of milk are used to illustrate phenomena related to the Planck era, the standard hot big bang model, cosmic inflation, problems with the formation of

  19. 24. Top of hot well looking forward, with overflow pipe ...

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

    24. Top of hot well looking forward, with overflow pipe shown at lower left of view. Hot well crosshead and crosshead guides appear above, behind which is main cylinder for walking beam engine. Trussed eccentric rods for engine valve gear appear to left and right of crosshead. - Ferry TICONDEROGA, Route 7, Shelburne, Chittenden County, VT

  20. 14 CFR 27.961 - Fuel system hot weather operation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 2013-01-01 2013-01-01 false Fuel system hot weather operation. 27.961 Section 27.961 Aeronautics and...ROTORCRAFT Powerplant Fuel System 27.961 Fuel system hot weather operation. Each suction lift fuel system and...