Note: This page contains sample records for the topic cgeh-1 coso hot from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: August 15, 2014.
1

Coso Hot Springs: A Condensate Fed Geothermal Feature  

Microsoft Academic Search

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

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

2007-01-01

2

Coso Hot Springs: A Condensate Fed Geothermal Feature  

NASA Astrophysics Data System (ADS)

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

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

2007-12-01

3

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

Microsoft Academic Search

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

Ben E. Lofgren

1990-01-01

4

Dipole--Dipole Resistivity Survey of a Portion O the Coso Hot Springs KGRA, Inyo County, California.  

National Technical Information Service (NTIS)

A detailed electrical resistivity survey of 54 line-km was completed at the Coso Hot Springs KGRA in September 1977. This survey has defined a bedrock resistivity low at least 4 sq mi (10 sq km) in extent associated with the geothermal system at Coso. The...

R. C. Fox

1978-01-01

5

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

Microsoft Academic Search

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

Chi-Yuh Young; Ronald W. Ward

1980-01-01

6

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

Microsoft Academic Search

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

Barbara P. Bishop; Dennis K. Bird

1987-01-01

7

Correlation of hydrothermal sericite composition with permeability and temperature, Coso Hot Springs geothermal field, Inyo County, California  

Microsoft Academic Search

Petrographic and geochemical analyses of cuttings from six wells in the Coso Hot Springs geothermal field show a systematic variation in the occurrence, texture, and composition of sericite that can be correlated with high permeability production zones and temperature. The wells studied intersect rhyolitic dikes and sills in the fractured granitic and dioritic basement rocks which serve as the reservoir

B. P. Bishop; D. K. Bird

1985-01-01

8

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

NASA Astrophysics Data System (ADS)

Two types of white micas are found in drillhole samples within the geothermal system at Coso Hot Springs. Low-permeability zones of the crystalline basement contain coarse-grained relict muscovite, whereas rock alteration near fracture zones at temperatures > 150°C is characterized by abundant finegrained sericite in association with secondary calcite and quartz and unaltered relict microcline. In this hydrothermal sericite there is an increase in interlayer K, octahedral Mg + Fetotal and tetrahedral Al with increasing temperature between ~215° to >250°C. Thermodynamic activity of the Al 2Si 4O 10(OH) 2 component of serielles, calculated using site-mixing approximations of HELGESON and AAGAARD (1985), decreases with increasing temperature between ~215° and >250°C. As a consequence of the observed variations in the interlayer, octahedral and tetrahedral site occupancies, the activity of KAl 2(AlSi 3O 10(OH) 2 is essentially constant in the Coso seriates over this temperature range. The calculated equilibrium distribution of aqueous species in the hydrothermal solutions produced from well 16-8, together with cation-activity phase diagrams that account for variations in sericite composition, requires a pH of ~6.7-6.8 at temperatures between 236° and 250°C. Comparison of predicted and observed phase relations with fluid compositions indicate that seriates are in local equilibrium with the geothermal reservoir fluid, whereas relict metamorphic muscovites are metastable. Although the compositions of hydrothermal sericites are a complex function of temperature, pressure and geothermal fluid composition, compositional relations observed at Coso together with published compositions of hydrothermal dioctahedral layer-silicates from the Salton Sea geothermal system demonstrates that elemental compositions of interlayer K and tetrahedral Al increase systematically with increasing temperature despite the dramatic differences in fluid compositions between these two geothermal systems. This suggests that the observed variations in interlayer and tetrahedral site occupancy is largely dependent on the enthalpy of hydrolysis reactions representing equilibrium between sericite solid solutions and the geothermal reservoir fluids.

Bishop, Barbara P.; Bird, Dennis K.

1987-05-01

9

Variation in sericite composition from fracture zones within the Coso Hot Sprints geothermal system  

SciTech Connect

Two types of white micas are found in drill hole samples within the geothermal system at Coso Hot Springs. Low-permeability zones of the crystalline basement contain coarse-grained relict muscovite, whereas rock alteration near fracture zones at temperatures > 150/sup 0/C is characterized by abundant fine-grained sericite in association with secondary calcite and quartz and unaltered relict microcline. In this hydrothermal sericite there is an increase in interlayer K, octahedral Mg + Fe/sub total/ and tetrahedral Al with increasing temperature between approx. 215/sup 0/ to >250/sup 0/C. Thermodynamic activity of the Al/sub 2/Si/sub 4/O/sub 10/(OH)/sub 2/ component of sericites, calculated using site-mixing approximations of HELGESON and AAGAARD (1985), decreases with increasing temperature between approx. 215/sup 0/ and >250/sup 0/C. Although the compositions of hydrothermal sericites are a complex function of temperature, pressure and geothermal fluid composition, compositional relations observed at Coso together with published compositions of hydrothermal dioctahedral layer-silicates from the Salton Sea geothermal system demonstrates that elemental compositions of interlayer K and tetrahedral Al increase systematically with increasing temperature despite the dramatic differences in fluid compositions between these two geothermal systems. This suggests that the observed variations in interlayer and tetrahedral site occupancy is largely dependent on the enthalpy of hydrolysis reactions representing equilibrium between sericite solid solutions and the geothermal reservoir fluids.

Bishop, B.P.; Bird, D.K.

1987-05-01

10

Exploration model for possible geothermal reservoir, Coso Hot Springs KGRA, Inyo Co. , California  

SciTech Connect

The purpose of this study was to test the hypothesis that a steam-filled fracture geothermal reservoir exists at Coso Hot Springs KGRA, as proposed by Combs and Jarzabek (1977). Gravity data collected by the USGS (Isherwood and Plouff, 1978) was plotted and compared with the geology of the area, which is well known. An east-west trending Bouguer gravity profile was constructed through the center of the heat flow anomaly described by Combs (1976). The best fit model for the observed gravity at the anomaly was obtained by combining the gravitational effect of the known geology and that of a hypothetical geothermal reservoir. The reservoir proposed in this study was modeled at a cylindrical disk of radius 12,500 ft., height 5000 ft., depth 5000 ft., and steam-filled porosity of 5%. Such a reservoir at the temperature suggested by hydrochemical geothermometers would be capable of sustaining a commercial-sized electric generation project.

Olson, D.M.; Robinson, R.H.

1980-09-01

11

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

PubMed

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

Simbahan, Jessica; Drijber, Rhae; Blum, Paul

2004-09-01

12

Regulatory, Land Ownership, and Water Availability Factors for a Magma Well: Long Valley Caldera and Coso Hot Springs, California  

SciTech Connect

The U.S. Department of Energy is currently engaged in a program to demonstrate the engineering feasibility of extracting thermal energy from high-level molten magma bodies. The program is being carried out under the direction of Sandia National Laboratories where a number of individual projects support the overall program. The existing program elements include (1) high-temperature materials compatibility testing; (2) studies of properties of melts of various compositions; and (3) the investigation of the economics of a magma energy extraction system. Another element of the program is being conducted with the cooperation of the U.S. Geological Survey, and involves locating and outlining magma bodies at selected sites using various geophysical techniques. The ultimate goal here will be to define the limits of a magma body as a drilling target. During an earlier phase of the program, more than twenty candidate study sites considered were evaluated based upon: (1) the likelihood of the presence of a shallow magma chamber, (2) the accessibility of the site, and (3) physical and institutional constraints associated with each site with respect to performing long-term experiments. From these early phase activities, the number of candidate sites were eventually narrowed to just 2. The sites currently under consideration are Coso Hot Springs and the Long Valley caldera (Figure 1). This report describes certain attributes of these sites in order to help identify potential problems related to: (1) state and federal regulations pertaining to geothermal development; (2) land ownership; and (3) water resource availability. The information sources used in this study were mainly maps, publications, and informative documents gathered from the California Division of Oil and Gas and the U.S. Department of the Interior. Environmental studies completed for the entire Long Valley caldera study area, and for portions of the Coso Hot Springs study area were also used for reference.

Blackett, Robert

1985-09-01

13

Tectonic setting of the Coso geothermal reservoir  

SciTech Connect

The Coso geothermal reservoir is being developed in Sierran-type crystalline bedrock of the Coso Mountains, a small desert mountain range just to the east of the Sierra Nevada and Rose Valley, which is the southern extension of the Owens Valley of eastern California Optimum development of this reservoir requires an understanding of the fracture hydrology of the Coso Mountains crystalline terrain and its hydrologic connection to regional groundwater and thermal sources. An interpreted, conceptually balanced regional cross section that extends from the Sierra Nevada through the geothermal reservoir to the Panamint Mountains is presented. The cross section is constrained by new reflection and refraction seismic data, gravity and magnetic modeling, drilling data from the geothermal reservoir, and published regional geologic mapping. The interpretation presented in the cross section and the geochemistry of the reservoir fluids is used to argue that the geothermal system is a thermal bulge on an otherwise normal fracture-controlled regional groundwater flow. This groundwater flow starts from recharge areas in the high Sierra Nevada and Coso Mountains and moves toward the very low desert valleys to the southeast. The hypothesis also suggest that the low-angle intracrustal detachment of the Basin Ranges may be controlled by thrust structures developed during the Cordilleran, Sevier plus Laramide, orogenic event.

Erskine, M.C.

1990-05-01

14

Study of Low-Grade Uranium Resources of the Coso Formation, Owens Valley, California.  

National Technical Information Service (NTIS)

The Tertiary Coso Formation is exposed along the northern and western flanks of the Coso Range on the east side of Owens Valley, Inyo County, California. The surficial uranium deposits in the Coso Formation are found in the lower fanglomerate sequence. Th...

1975-01-01

15

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

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

16

3D Magnetotelluic characterization of the Coso GeothermalField  

SciTech Connect

Electrical resistivity may contribute to progress inunderstanding geothermal systems by imaging the geometry, bounds andcontrolling structures in existing production, and thereby perhapssuggesting new areas for field expansion. To these ends, a dense grid ofmagnetotelluric (MT) stations plus a single line of contiguous bipolearray profiling has been acquired over the east flank of the Cosogeothermal system. Acquiring good quality MT data in producing geothermalsystems is a challenge due to production related electromagnetic (EM)noise and, in the case of Coso, due to proximity of a regional DCintertie power transmission line. To achieve good results, a remotereference completely outside the influence of the dominant source of EMnoise must be established. Experimental results so far indicate thatemplacing a reference site in Amargosa Valley, NV, 65 miles from the DCintertie, isstill insufficient for noise cancellation much of the time.Even though the DC line EM fields are planar at this distance, theyremain coherent with the nonplanar fields in the Coso area hence remotereferencing produces incorrect responses. We have successfully unwrappedand applied MT times series from the permanent observatory at Parkfield,CA, and these appear adequate to suppress the interference of thecultural EM noise. The efficacy of this observatory is confirmed bycomparison to stations taken using an ultra-distant reference site eastof Socorro, NM. Operation of the latter reference was successful by usingfast ftp internet communication between Coso Junction and the New MexicoInstitute of Mining and Technology, using the University of Utah site asintermediary, and allowed referencing within a few hours of datadownloading at Coso. A grid of 102 MT stations was acquired over the Cosogeothermal area in 2003 and an additional 23 stations were acquired toaugment coverage in the southern flank of the first survey area in 2005.These data have been inverted to a fully three-dimensional conductivitymodel. Initial analysis of the Coso MT data was carried out using 2D MTimaging. An initial 3D conductivity model was constructed from a seriesof 2D resistivity images obtained using the inline electric fieldmeasurements (Zyx impedance elements) along several measurementtransects. This model was then refined through a 3D inversion process.This model shows the controlling geological structures possiblyinfluencing well production at Coso and correlations with mapped surfacefeatures such as faults and regional geoelectric strike. The 3D modelalso illustrates the refinement in positioning of conductivity contactswhen compared to isolated 2D inversion transects. The conductivity modelhas also been correlated with microearthquake locations, well fluidproduction intervals and most importantly with an acoustic and shearvelocity model derived by Wu and Lees (1999). This later correlationshows the near-vertical high conductivity structure on the eastern flankof the producing field is also a zone of increased acoustic velocity andincreased Vp/Vs ratio bounded by mapped fault traces. South of theDevil's Kitchen is an area of high geothermal well density, where highlyconductive near surface material is interpreted as a clay cap alterationzone manifested from the subsurface geothermal fluids and relatedgeochemistry. Beneath the clay cap, however, the conductivity isnondescript, whereas the Vp/Vs ratio is enhanced over the productionintervals. It is recommended that more MT data sites be acquired to thesouthwest of the Devil's Kitchen area to better refine the conductivitymodel in that area.

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

2007-04-23

17

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

USGS Publications Warehouse

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

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

2006-01-01

18

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

NASA Astrophysics Data System (ADS)

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

Zhang, Q.; Lin, G.

2012-12-01

19

Attenuation and source properties at the Coso Geothermal area, California  

USGS Publications Warehouse

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

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

1999-01-01

20

Late Cenozoic ring faulting and volcanism in the Coso Range area of California  

Microsoft Academic Search

The Coso Range of southeastern California is underlain principally by Mesozoic granitic rocks that are partly veneered by upper Cenozoic volcanic rocks. The volcanic units (in apparent decreasing age) include (1) widespread basaltic flows, (2) dacitic flows and tuff, and (3) rhyolitic domes and flows and basaltic cones and flows. These volcanic rocks are encompassed by an oval-shaped zone of

Wendell A. Duffield

1975-01-01

21

Subsurface Characterization Beneath the Coso Geothermal Field by Ambient Noise Tomography  

NASA Astrophysics Data System (ADS)

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

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

2009-12-01

22

Hot Sauce Hot Spots  

NSDL National Science Digital Library

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

Muller, Eric

2007-01-01

23

Time lapse gravity monitoring at Coso geothermal field  

NASA Astrophysics Data System (ADS)

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

Woolf, Rachel Vest

24

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

NASA Astrophysics Data System (ADS)

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

Feldman, M.; Raub, T. D.

2009-12-01

25

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

NASA Astrophysics Data System (ADS)

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

Unruh, J. R.; Hauksson, E.

2007-12-01

26

Teleseismic evidence for a low-velocity body under the Coso geothermal area  

Microsoft Academic Search

Teleseismic P wave arrivals were recorded by a dense array of seismograph stations located in the Coso geothermal area, California. The resulting pattern of relative residuals an area showing approximately 0.2-s excess travel time that migrates with changing source azimuth, suggesting that the area is the 'delay shadow' produced by a deep, low-velocity body. Inversion of the relative residual data

P. Reasenberg; W. Ellisworth; A. Walter

1980-01-01

27

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

Microsoft Academic Search

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

Ward H. Austin

1990-01-01

28

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

SciTech Connect

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

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

1997-07-01

29

Hot Science: Hot rocks  

NSDL National Science Digital Library

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

30

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

USGS Publications Warehouse

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

Bacon, C. R.; Metz, J.

1984-01-01

31

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

SciTech Connect

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

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

2006-04-01

32

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

Microsoft Academic Search

Archaeologists frequently assign artifacts to chemically discrete subsignatures of major obsidian sources. While the technical ability to do so has been demonstrated, it remains to be shown that such information is behaviorally meaningful. Indeed, some analysts choose not to make such determinations under the presumption that the data are not anthropologically relevant. Using a case study from the Coso Volcanic

Jelmer W. Eerkens; Jeffrey S. Rosenthal

2004-01-01

33

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

Microsoft Academic Search

Uranium and thorium decay series isotopes were measured in fluids and solids in the Coso geothermal system to assess the utility and constrain the limitations of the radioisotopic approach to the investigation of rock-water interaction. Fluid radioisotope measurements indicate substantial kilometer-scale variability in chemistry. Between 1988 and 1990, radium isotope activity ratios indicate temporal variability, which is exhibited by apparent

B. W. Leslie; D. Hammond

2007-01-01

34

Hot spot  

Microsoft Academic Search

Using an array of portable seismometers spread out directly above the proposed site of a hot spot, researchers from the Carnegie Institution of Washington (CIW) recently produced the first high-resolution seismic image of a mantle plume---a jet of hot material that rises from the deep mantle and partially melts, producing magmas that migrate to the surface through ``hot spot'' volcanoes.

Michael Carlowicz

1997-01-01

35

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

USGS Publications Warehouse

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

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

2004-01-01

36

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

USGS Publications Warehouse

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

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

1986-01-01

37

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

NASA Astrophysics Data System (ADS)

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

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

2011-02-01

38

TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES IN THE COSO GEOTHERMAL FIELD FROM ANALYSES OF SHEAR-WAVE SPLITTING  

Microsoft Academic Search

This project aims to improve understanding of the subsurface fracture system in the Coso geothermal field, located in the east central California. We applied shear-wave splitting technique on a set of high quality, locally recorded microearthquake (MEQ) data. Four major fracture directions have been identified from the seismograms recorded by the permanent sixteen-station down-hole array: N10- 20W, NS, N20E, and

Gordana Vlahovic; Maya Elkibbi; Jose A. Rial

39

Hot Air  

NSDL National Science Digital Library

In this activity, learners set up an experiment to investigate the effects of hot air on the path of a laser beam. They observe the wandering position of the laser beam spot on the wall after the light travels through hot air rising from the candle flame. Learners produce a table of observations from both the Cool Air and Hot Air experiments, and answer questions using evidence from their experiment. Apply what learners discover in this experiment to real-life by discussing why stars "twinkle."

Observatory, The U.

2011-01-01

40

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

USGS Publications Warehouse

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.

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

1979-01-01

41

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

NASA Astrophysics Data System (ADS)

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

Eckert, A.; Connolly, P.

2006-12-01

42

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

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.

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

2009-01-01

43

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

SciTech Connect

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

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

2008-04-01

44

Hot Canyon  

SciTech Connect

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

None

2012-06-18

45

Hot Canyon  

SciTech Connect

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

None

2012-01-01

46

Hot Canyon  

ScienceCinema

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

None

2013-03-01

47

Hot Tickets  

ERIC Educational Resources Information Center

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…

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

2008-01-01

48

HOT AIR  

NSDL National Science Digital Library

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

49

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

NASA Astrophysics Data System (ADS)

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

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

2006-12-01

50

Hot Meetings  

NASA Technical Reports Server (NTRS)

A colleague walked by my office one time as I was conducting a meeting. There were about five or six members of my team present. The colleague, a man who had been with our institution (The Johns Hopkins Applied Physics Lab, a.k.a. APL) for many years, could not help eavesdropping. He said later it sounded like we we re having a raucous argument, and he wondered whether he should stand by the door in case things got out of hand and someone threw a punch. Our Advanced Composition Explorer (ACE) team was a hot group, to invoke the language that is fashionable today, although we never thought of ourselves in those terms. It was just our modus operandi. The tenor of the discussion got loud and volatile at times, but I prefer to think of it as animated, robust, or just plain collaborative. Mary Chiu and her "hot" team from the Johns Hopkins Applied Physics Laboratory built the Advanced Composition Explorer spacecraft for NASA. Instruments on the spacecraft continue to collect data that inform us about what's happening on our most important star, the Sun.

Chiu, Mary

2002-01-01

51

Hot tub folliculitis  

MedlinePLUS

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

52

Solar 'hot spots' are still hot  

NASA Technical Reports Server (NTRS)

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

Bai, Taeil

1990-01-01

53

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

NASA Astrophysics Data System (ADS)

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

Hauksson, E.; Unruh, J.

2007-12-01

54

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

PubMed

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

Chen, Huichao; Zhao, Changsui; Ren, Qiangqiang

2012-01-01

55

Lava fingerprinting using paleomagnetism and innovative X-ray fluorescence spectroscopy: A case study from the Coso volcanic field, California  

NASA Astrophysics Data System (ADS)

We demonstrate an efficient method of rigorously separating difficult-to-distinguish lavas into eruptive units based on paleomagnetic remanence direction and rapid X-ray fluorescence spectroscopy (XRF) for Rb, Sr, Y, Zr, and Nb of polished paleomagnetic core samples (called PC XRF). Combined use of paleomagnetic remanence and PC XRF for lava fingerprinting allows correlation of individual eruptive units from one locality to another, permitting compilation of composite stratigraphy and paleomagentic measurement of relative vertical axis rotation of fault-bounded blocks. We test this lava fingerprinting method on rocks from the Coso volcanic field, California, against similar fingerprinting using XRF analysis by established methods. Resulting unit definitions and correlations are the same by both XRF techniques when coupled with paleomagnetic data, but at great time and cost savings with PC XRF. PC XRF analysis is possible because (1) matrix and grain size effects are minimal for the element set analyzed, (2) moderately phyric to aphyric polished paleomagnetic cores are already homogenous on spatial scales of 2 cm, and (3) use of element ratios cancels out some analytical uncertainties as well as minimizes effects of concentration variations due to fractional crystallization. Paleomagnetic remanence direction is an indispensable part of fingerprinting because it distinguishes flows of similar chemistry and can also place constraints on the duration of emplacement of each eruptive unit.

Pluhar, Christopher J.; Coe, Robert S.; Sampson, Daniel E.; Glen, Jonathan M. G.; Monastero, Francis C.; Tanner, S. Bruce

2005-04-01

56

Modelling Hot Air Balloons.  

ERIC Educational Resources Information Center

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

Brimicombe, M. W.

1991-01-01

57

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

58

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

SciTech Connect

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

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

2008-04-01

59

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

NASA Astrophysics Data System (ADS)

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

Leslie, B. W.; Hammond, D.

2007-12-01

60

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

NASA Astrophysics Data System (ADS)

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

Hauksson, Egill; Unruh, Jeffrey

2007-06-01

61

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

NASA Astrophysics Data System (ADS)

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

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

2006-10-01

62

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

USGS Publications Warehouse

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

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

1984-01-01

63

HotBot  

NSDL National Science Digital Library

HotBot, a service of HotWired Ventures, uses the Inktomi search engine as the heart of its new Internet search service. It claims to index the full text contents of 50 million Web pages, as well as Usenet news and mailing lists. This would make it the largest search engine on the Internet. HotBot supports Boolean AND/OR/NOT, and phrase searching. It provides relevance feedback with retrieval. It also supports chronological, domain, and geographic searches, as well as media type searches such as Java, VRML, and Acrobat. HotBot is a public "beta" site and encourages feedback and bug reports.

64

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

NASA Technical Reports Server (NTRS)

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

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

1980-01-01

65

Hot Spot at Yellowstone  

ERIC Educational Resources Information Center

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…

Dress, Abby

2005-01-01

66

Hot Air Balloon  

NSDL National Science Digital Library

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

Centers, Oakland D.

2012-01-01

67

Hot yoga and pregnancy  

PubMed Central

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

Chan, Justin; Natekar, Aniket; Koren, Gideon

2014-01-01

68

Solar Hot Box  

NSDL National Science Digital Library

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

69

Hot water heating system  

Microsoft Academic Search

A solar hot water heating system has a primary tank heated by solar energy utilizing a heat transfer medium circulated between a solar collector and a heat exchanger located in the primary tank. Usually a back-up tank is provided to supplement the solar system. The primary tank receives cold water from a pressurized source. Its hot water outlet is connected

1984-01-01

70

Household hot water systems  

Microsoft Academic Search

An arrangement for combination with the conventional hot water system of a house or building in which the water is conventionally heated and stored in a tank, the arrangement comprising a solar energy panel (at an upper level) with a thermostatic valve and a supplementary cold water tank, connected into the system in such a way that hot water is

Tacchi

1983-01-01

71

Hot Weather Tips  

MedlinePLUS

... 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 those ... conditions such as vascular disease or diabetes, the weather does not have to hit 100 degrees to ...

72

The Earth's Hot Spots.  

ERIC Educational Resources Information Center

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

Vink, Gregory E.; And Others

1985-01-01

73

CSA Hot Topics Series  

NSDL National Science Digital Library

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

74

Hot ice computer  

NASA Astrophysics Data System (ADS)

We experimentally demonstrate that supersaturated solution of sodium acetate, commonly called ‘hot ice’, is a massively-parallel unconventional computer. In the hot ice computer data are represented by a spatial configuration of crystallization induction sites and physical obstacles immersed in the experimental container. Computation is implemented by propagation and interaction of growing crystals initiated at the data-sites. We discuss experimental prototypes of hot ice processors which compute planar Voronoi diagram, shortest collision-free paths and implement AND and OR logical gates.

Adamatzky, Andrew

2009-12-01

75

Hot spots of Io  

NASA Technical Reports Server (NTRS)

The size and temperature, morphology and distribution, variability, possible absorption features, and processes of hot spots on Io are discussed, and an estimate of the global heat flux is made. Size and temperature information is deconvolved to obtain equivalent radius and temperature of hot spots, and simultaneously obtained Voyager thermal and imaging data is used to match hot sources with specific geologic features. In addition to their thermal output, it is possible that hot spots are also characterized by production of various gases and particulate materials; the spectral signature of SO2 has been seen. Origins for relatively stable, low temperature sources, transient high temperature sources, and relatively stable, high-tmperature sources are discussed.

Pearl, J. C.; Sinton, W. M.

1982-01-01

76

Hot Accretion Disks Revisited  

NASA Astrophysics Data System (ADS)

All previous studies of hot (Tp 1010-1012 K), optically thin accretion disks have neglected either the presence of e+ e- pairs or advective cooling. Thus all hot disk models constructed previously have not been self-consistent. In this paper we calculate local disk models including pair physics, relevant radiative processes in the hot plasma, and the effect of advective cooling. We use a modification of the Björnsson & Svensson mapping method. We find that the role of e+ e- pairs in the structure of hot, optically thin accretion disks is far less significant than was previously thought. The improved description of the radiation-matter interactions provided in the present paper modify the previously obtained values of the critical parameters characterizing advectively dominated flows.

Bjoernsson, Gunnlaugur; Abramowicz, Marek A.; Chen, Xingming; Lasota, Jean-Pierre

1996-08-01

77

Geothermal hot water system  

SciTech Connect

Geothermal hot water system including a hot water tank and a warm water tank which are heated independently of each other by a close loop freon system. The closed loop freon system includes a main condenser which heats water for the warm water tank and a super-heated condenser which heats water for the hot water tank, and where the freon passes through a water evaporator which is heated by water such as from a well or other suitable source. The water evaporator in the closed loop freon system passes the water through but no environmental change to the water. An electrical circuit including aquastats in the warm water tank connected therethrough controls operation of the closed loop freon system including respective pumps on the super-heated condenser and main condenser for pumping water. Pumps pump water through the main condenser for the warm tank and through the super-heated condenser for the hot tank. The system provides for energy conservation in that the head pressure of the compressor is kept in the lower operating ranges as determined by the discharge flow of the main condenser which varies by the head pressure and temperature flow control which varies by temperature. The geothermal hot water system uses a least amount of energy in heating the water in the hot tank as well as the warm tank.

Dittell, E.W.

1983-05-10

78

Automatic hot water recovery system  

Microsoft Academic Search

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

Haws

1982-01-01

79

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

SciTech Connect

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.

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

2010-05-01

80

IR Hot Wave  

Microsoft Academic Search

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

2010-01-01

81

Hot Melt Recharge System.  

National Technical Information Service (NTIS)

A package assembly is described for precisely positioning a charge of hot melt adhesive onto an attachment pad or a point of use. The adhesive is heated to softening or melt temperature (280 F - 325 F) and thereafter cooled to resolidifying temperature. A...

D. J. Progar

1983-01-01

82

Hot Melt Recharge System.  

National Technical Information Service (NTIS)

A package assembly for precisely positioning a charge of hot melt adhesive onto an attachment pad or point of use is described. The adhesive is heated to softening or melt temperature (280 F to 325 F) and thereafter cooled to resolidifying temperature. A ...

D. J. Progar

1982-01-01

83

TRUEX hot demonstration  

Microsoft Academic Search

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

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

1990-01-01

84

The Deep Hot Biosphere  

Microsoft Academic Search

The first inhabitants of planet Earth were single-celled microorganisms and they are still with us today. Their name is truly legion, for they live everywhere, from boiling hot springs at the Earth's surface and on the seafloor to the coldest waters of the oceans and the Antarctic lakes. They are the masters of evolutionary adaptation, who have colonized the entire

Harmon Craig

1999-01-01

85

Hot off the Press  

ERIC Educational Resources Information Center

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

Brisco, Nicole D.

2007-01-01

86

Hot gas generator  

Microsoft Academic Search

This patent describes a hot gas generator. It comprises: a vessel having a wall defining narrow, spaced apart inlet and outlet ends interconnected by a relatively wide, generally spherical combustion chamber; a pair of smooth hemispherical liners loosely positioned within the wall so as to be disposed about the combustion chamber. The hemispherical liners normally having a groove at an

J. R. Shekleton; R. W. Smith

1990-01-01

87

Zen Hot Dog Molecules  

ERIC Educational Resources Information Center

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

Ryan, Dennis

2009-01-01

88

Zen Hot Dog Molecules  

NASA Astrophysics Data System (ADS)

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

Ryan, Dennis

2009-04-01

89

Some Like it Hot  

NSDL National Science Digital Library

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

Bortman, Henry; Magazine, Astrobiology

90

Hot-hole photodetectors  

NASA Astrophysics Data System (ADS)

By injecting high-energy charge carriers (dubbed 'hot holes') into a semiconductor, scientists have succeeded in realizing photodetectors capable of detecting ultralong wavelengths. Unil Perera from Georgia State University in the USA explains how the devices work and how they can be improved.

2014-05-01

91

OECD Focus Hot File  

NSDL National Science Digital Library

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

92

Kamchatka's thermal hot springs  

NSDL National Science Digital Library

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

Kamchatka, Vision O.

93

Editor's Note: Hot Properties  

NSDL National Science Digital Library

Properties are "hot," not in terms of real estate but in science class. Here, the editor highlights the feature articles related to this month's theme, Properties of Objects and Materials. With these articles as a guide, you can move students toward a deeper understanding of property. As you do so, they will build a strong foundation for future science learning.

Ohana, Chris

2008-01-01

94

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

NASA Astrophysics Data System (ADS)

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

Maris, Virginie

95

A single crystal EPR study of VO 2+ ions doped in Cs 2Co(SO 4) 2.6H 2O Tutton salt  

NASA Astrophysics Data System (ADS)

EPR spectra of VO 2+ ions doped in single crystals of Cs 2Co(SO 4) 2.6H 2O single crystals have been studied at various temperatures (390-103 K) on X-band frequency. The detailed EPR analysis shows three vanadyl complexes with differing intensities. The g and A tensors are found to be axially symmetric. The intense vanadyl complexes in the lattice are found to occupy the Co 2+ substitutional sites, whereas the weak vanadyl complex at the interstitial sites. The optical absorption spectrum at room temperature shows three absorption bands characteristic of VO 2+ ions in tetragonal symmetry. By correlating the EPR and optical data, the molecular bonding coefficients and the Fermi contact interaction terms have been evaluated and discussed. The line broadening of VO 2+ spectra on cooling the crystal is explained on the basis of spin-lattice relaxation narrowing. The spin-lattice relaxation time for the host Co 2+ ions has been estimated at various temperatures.

Narasimhulu, K. V.; Rao, J. L.

1997-12-01

96

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 ...

97

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

98

Hot chocolate effect  

SciTech Connect

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

Crawford, F.S.

1982-05-01

99

Hot fire, cool soil  

NASA Astrophysics Data System (ADS)

Wildfires greatly increase a landscape's vulnerability to flooding and erosion events by removing vegetation and changing soils. Fire damage to soil increases with increasing soil temperature, and, for fires where smoldering combustion is absent, the current understanding is that soil temperatures increase as fuel load and fire intensity increase. Here, however, we show that this understanding that is based on experiments under homogeneous conditions does not necessarily apply at the more relevant larger scale where soils, vegetation, and fire characteristics are heterogeneous. In a catchment-scale fire experiment, soils were surprisingly cool where fuel load was high and fire was hot and, conversely, soils were hot where expected to be cooler. This indicates that the greatest fire damage to soil can occur where fuel load and fire intensity are low rather than high, and has important implications for management of fire-prone areas prior to, during, and after fire events.

Stoof, Cathelijne R.; Moore, Demie; Fernandes, Paulo M.; Stoorvogel, Jetse J.; Fernandes, Ricardo E. S.; Ferreira, António J. D.; Ritsema, Coen J.

2013-04-01

100

Hot Billet Surface Qualifier  

SciTech Connect

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

Tzyy-Shuh Chang

2007-04-30

101

Exploring Hot Neptune Atmospheres  

Microsoft Academic Search

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

Jonathan Fortney; Mark Marley; Didier Saumon

2008-01-01

102

Hot-Wheeler-Coaster  

NSDL National Science Digital Library

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

Shaw, Steven

2011-10-13

103

Solar Hot Water Heater  

NASA Technical Reports Server (NTRS)

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.

1978-01-01

104

Jupiter's Hot, Mushy Moon  

NASA Technical Reports Server (NTRS)

Jupiter's moon Io is the most volcanically active body in the Solar System. Observations by instruments on the Galileo spacecraft and on telescopes atop Mauna Kea in Hawai'i indicate that lava flows on Io are surprisingly hot, over 1200 oC and possibly as much as 1300 oC; a few areas might have lava flows as hot as 1500 oC. Such high temperatures imply that the lava flows are composed of rock that formed by a very large amount of melting of Io's mantle. This has led Laszlo Keszthelyi and Alfred S. McEwen of the University of Arizona and me to reawaken an old hypothesis that suggests that the interior of Io is a partially-molten mush of crystals and magma. The idea, which had fallen out of favor for a decade or two, explains high-temperature hot spots, mountains, calderas, and volcanic plains on Io. If correct, Io gives us an opportunity to study processes that operate in huge, global magma systems, which scientists believe were important during the early history of the Moon and Earth, and possibly other planetary bodies as well. Though far from proven, the idea that Io has a ocean of mushy magma beneath its crust can be tested with measurements by future spacecraft.

Taylor, G. Jeffrey

2003-01-01

105

CALCULATION OF THE SURFACE AREAS AND THE ACID STRENGTH OF NiSO4, CuSO4 AND CoSO4.H20 AND THE USE OF THESE CATALYSTS ON DEHYDRATION OF SOME ALCOHOLS  

Microsoft Academic Search

SUMMARY In this study; the surfaces of the catalysts were examined by electron microscope and their surface areas were calculated with gas adsorption method as a unit of m2g-1. In addition, the acid strength on solid catalysts (NiSO4, CuSO4, CoSO4.H2O) was determined by Hammett indicator adsorption method and also, dehydration reactions of 2,6-dimethyl-4-heptanol, 3,7-dimethyl-3-octanol and 2-octanol were investigated with the

MUSTAFA RIDVANLAR; ÜLKÜ OYMAN

106

PREFACE: Hot Quarks 2004  

NASA Astrophysics Data System (ADS)

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 future—that 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.

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

2005-04-01

107

Hot oiling spreadsheet  

SciTech Connect

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

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

1996-09-01

108

Hot cell examination table  

DOEpatents

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

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

1991-01-01

109

Hot gas generator  

SciTech Connect

This patent describes a hot gas generator. It comprises: a vessel having a wall defining narrow, spaced apart inlet and outlet ends interconnected by a relatively wide, generally spherical combustion chamber; a pair of smooth hemispherical liners loosely positioned within the wall so as to be disposed about the combustion chamber. The hemispherical liners normally having a groove at an interface therebetween and being formed of a material adapted to thermally expand radially and circumferentially under heat. The hemispherical liners expanding to close the groove at the interface in a manner producing relatively little stress thereon; the portion of the wall defining the combustion chamber including a generally spherical recess.

Shekleton, J.R.; Smith, R.W.

1990-09-11

110

The Hot Tub Mystery  

NSDL National Science Digital Library

Roma and Clint Underhill are relaxing after a stressful day in their hot tub with some wine. But tragedy strikes, and the next morning their lifeless bodies are found in the water by their housekeeper. The paramedics who respond to her frantic 911 call pronounce the couple dead at the scene and call in the police to investigate. Developed for use in a lower-level undergraduate course on human physiology, students work through the various parts of this interrupted case to discover the cause of death, and in the process learn about blood pressure regulation.

House, Herbert

2005-01-01

111

MSFC hot air collectors  

NASA Technical Reports Server (NTRS)

A description of the hot air collector is given that includes a history of development, a history of the materials development, and a program summary. The major portion of the solar energy system cost is the collector. Since the collector is the heart of the system and the most costly subsystem, reducing the cost of producing collectors in large quantities is a major goal. This solar collector is designed to heat air and/or water cheaply and efficiently through the use of solar energy.

Anthony, K.

1978-01-01

112

What's Hot? What's Not?  

NSDL National Science Digital Library

When Goldilocks finds three bowls of porridge at different temperatures in the three bears' house, she accurately assess 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; ahh, this porridge is just right!" Goldilocks' famous line is a perfect lead-in for an inquiry with upper elementary students that explores the concept of heat energy as measured by temperature. In the investigation, students consider the variable that might account for temperature differences between each bear's porridge.

Buczynski, Sandy

2006-10-01

113

Hot and Cold  

NSDL National Science Digital Library

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

Industry, Oregon M.

1997-01-01

114

Hot air drum evaporator  

DOEpatents

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

Black, Roger L. (Idaho Falls, ID)

1981-01-01

115

Single-chamber silicic magma system inferred from shear wave discontinuities of the crust and uppermost mantle, Coso geothermal area, California  

NASA Astrophysics Data System (ADS)

Analysis of seismograms from teleseismic rays traversing the Coso geothermal area near Ridgecrest, California, suggests the geothermal system lies over a single shallow magma reservoir (˜5 km below the surface) that also plays a crucial role in the local change in deformation style from areas to the north and west. The character of the magma reservoir and the absence of a lower crustal magma reservoir is inferred from three crustal P-to-S conversions observed using receiver function analysis: (1) A high-amplitude, shallow, negative arrival, Ps-P time of 0.7-0.9 s (3-5 km below sea level (bsl)), (2) a moderate amplitude, positive conversion, Ps-P time of 2.1-2.5 s (14-17 km bsl), and (3) the Moho conversion, Ps-P time of 4.0-4.2 s (30-32 km bsl). Observations of Moho converted arrivals indicate that the interface is mostly flat and uncomplicated throughout the study area, while the midcrustal conversion is laterally variable in amplitude and depth. The absence of the large negative amplitude conversion on waveforms recorded at stations outside the geothermal area strongly suggests that the feature lies only underneath the modern geothermal area. In addition, rays sampling the shallow converter also contain later arrivals with retrograde moveout consistent with an origin as reverberations above the conversion. Receiver functions calculated from synthetic data using a single isotropic layer over a half-space indicates that the shear velocity decreases by 30% across the interface (VS1 = 2.6 km/s; VS2 = 1.8 km/s; layer one thickness 4.9 km), further supporting the presence of shallow magma.

Wilson, Charles K.; Jones, Craig H.; Gilbert, Hersh J.

2003-05-01

116

Single-chamber Silicic Magma System Inferred From Shear-wave Discontinuities of the Crust and Uppermost Mantle, Coso Geothermal Area, California  

NASA Astrophysics Data System (ADS)

Analysis of seismograms from teleseismic rays traversing the Coso geothermal area near Ridgecrest, California suggests the geothermal system lies over a single shallow magma reservoir (~5 km below the surface) that also plays a crucial role in the local change in deformation style from areas to the north and west. The character of the magma reservoir and the absence of a lower crustal magma reservoir is inferred from three crustal P-to-S conversions observed using receiver function analysis: (1) A high amplitude, shallow, negative arrival, Ps-P time of 0.7-0.9 seconds (3-5 km below sea level), (2) a moderate amplitude, positive conversion, Ps-P time of 2.1-2.5 seconds (14-17 km below sea level), and (3) the Moho conversion, Ps-P time of 4.0-4.2 seconds (30-32 km below sea level). Observations of Moho converted arrivals indicate the interface is mostly flat and uncomplicated throughout the study area while the mid-crustal conversion is laterally variable in amplitude and depth. The absence of the large negative amplitude conversion on waveforms recorded at stations outside the geothermal area strongly suggests the feature lies only underneath the modern geothermal area. In addition, rays sampling the shallow converter also contain later arrivals with retrograde moveout consistent with an origin as reverberations above the conversion. Receiver functions calculated from synthetic data using a single isotropic layer over a half space indicates that the shear velocity decreases by 30% across the interface (VS1=2.6 km/s; VS2=1.8 km/s; layer one thickness=4.9 km) further supporting the presence of shallow magma.

Wilson, C. K.; Jones, C. H.; Gilbert, H. J.

2002-12-01

117

Configurable hot spot fixing system  

NASA Astrophysics Data System (ADS)

Hot spot fixing (HSF) method has been used to fix many hot spots automatically. However, conventional HSF based on a biasing based modification is difficult to fix many hot spots under a low-k1 lithography condition. In this paper we proposed a new HSF, called configurable hotspot fixing system. The HSF has two major concepts. One is a new function to utilize vacant space around a hot spot by adding new patterns or extending line end edges around the hot spot. The other is to evaluate many candidates at a time generated by the new functions. We confirmed the proposed HSF improves 73% on the number of fixing hot spots and reduces total fixing time by 50% on a device layout equivalent to 28nm-node. The result shows the proposed HSF is effective for layouts under the low-k1 lithography condition.

Kajiwara, Masanari; Kobayashi, Sachiko; Mashita, Hiromitsu; Aburada, Ryota; Furuta, Nozomu; Kotani, Toshiya

2014-03-01

118

Hot Subdwarf Stars  

NASA Astrophysics Data System (ADS)

Hot subdwarf stars (sdBs, sdOs) are core helium-burning stars at the blue end of the horizontal branch or have evolved even beyond that stage. They are found in all Galactic stellar populations and are sufficiently common to account for the UV-upturn of early-type galaxies. About half of the sdBs reside in close binaries; companions are white dwarfs or low-mass main-sequence stars. Binary population-synthesis models explain naturally the actual sdB binary fractions of field and globular cluster stars as well as of He-sdOs if white-dwarf mergers are considered. Hot helium flashes explain the chemical composition of He-sdOs. Asteroseismology of a dozen pulsating sdB stars allowed determination of their masses and detection of a planet to V391 Peg. The discoveries of an sdO star unbound to the Galaxy, potential SN Ia progenitors and probably a hidden population of neutron stars or black hole companions have great impact on astrophysics at large.

Heber, Ulrich

2009-09-01

119

Radiations from hot nuclei  

NASA Technical Reports Server (NTRS)

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.

Malik, F. Bary

1993-01-01

120

Hot, Dry and Cloudy  

NASA Technical Reports Server (NTRS)

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

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

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

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

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

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

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

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

2007-01-01

121

Full of Hot Air: Hot Air Balloon Building  

NSDL National Science Digital Library

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

Houston, Children'S M.

2010-01-01

122

Hot toys are dead: long live hot products  

Microsoft Academic Search

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

Christopher Byrne

2005-01-01

123

TRUEX hot demonstration  

SciTech Connect

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.

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

1990-04-01

124

Hot Planet - Cold Comfort  

NSDL National Science Digital Library

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

125

Thyroid 'hot' nodules  

PubMed Central

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

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

1972-01-01

126

Heat recovery and hot water circulation system  

Microsoft Academic Search

A heat recovery and hot water circulation system for use with refrigeration means and a hot water reservoir is disclosed. A hot water distribution conduit is coupled intermediately to the cold water inlet and hot water outlet of the reservoir for supplying hot water to a remote station having a number of faucets coupled to the distribution conduit, and a

G. W. Keller; R. J. Yaeger

1982-01-01

127

Hot Hollow Cathode Gun Assembly.  

National Technical Information Service (NTIS)

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 th...

J. D. Zeren

1983-01-01

128

Hot hollow cathode gun assembly  

NASA Astrophysics Data System (ADS)

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.

Zeren, J. D.

1983-11-01

129

Mammoth Hot Springs Online Tour  

NSDL National Science Digital Library

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

Park, Yellowstone N.

130

Solar hot water heating system  

Microsoft Academic Search

A solar hot water heating system is provided with solar collectors connected to a hot water storage tank with a recirculating pump to circulate the cooler water in the storage tank through the collector to absorb heat therefrom and to be returned to the storage tank. A plurality of temperature sensors are placed throughout the system to monitor various temperatures

J. V. Budzynski; D. A. James

1981-01-01

131

Hospital service hot water heating  

Microsoft Academic Search

This paper explores some of the design criteria and alternate solutions that an engineer might want to consider when designing a service hot water system for a hospital. Guidelines give the following estimated service hot water requirements for a hospital. Gallon per hr. per bed: clinical, 3; dietary, 2; laundry, 2. In addition, the guidelines state that these quantities of

Critschke

1985-01-01

132

Hot water saver. Final report  

Microsoft Academic Search

The Hot Water Saver consists of a cylinder mounted at the water heater in the cold water inlet pipe and a crossover pipe connecting the hot and cold water pipes at the most distant point of use from the water heater. The cylinder contains a piston with a rod connected to the upper side which extends through the top of

Haws

1984-01-01

133

Hot Water Saver. Final Report.  

National Technical Information Service (NTIS)

The Hot Water Saver consists of a cylinder mounted at the water heater in the cold water inlet pipe and a crossover pipe connecting the hot and cold water pipes at the most distant point of use from the water heater. The cylinder contains a piston with a ...

S. K. Haws

1984-01-01

134

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...

135

Keep Your Cool in Hot Weather  

MedlinePLUS

... Submit Button CDC Features Keep Your Cool in Hot Weather Language: English Español (Spanish) Share Compartir Learn ... and how to stay cool and safe in hot weather. Getting too hot can make you sick. ...

136

Techniques for hot structures testing  

NASA Technical Reports Server (NTRS)

Hot structures testing have been going on since the early 1960's beginning with the Mach 6, X-15 airplane. Early hot structures test programs at NASA-Ames-Dryden focused on operational testing required to support the X-15 flight test program, and early hot structures research projects focused on developing lab test techniques to simulate flight thermal profiles. More recent efforts involved numerous large and small hot structures test programs that served to develop test methods and measurement techniques to provide data that promoted the correlation of test data with results from analytical codes. In Nov. 1988 a workshop was sponsored that focused on the correlation of hot structures test data with analysis. Limited material is drawn from the workshop and a more formal documentation is provided of topics that focus on hot structures test techniques used at NASA-Ames-Dryden. Topics covered include the data acquisition and control of testing, the quartz lamp heater systems, current strain and temperature sensors, and hot structures test techniques used to simulate the flight thermal environment in the lab.

Deangelis, V. Michael; Fields, Roger A.

1990-01-01

137

Tunnelling hot electron transfer amplifiers  

NASA Astrophysics Data System (ADS)

Significant advances were achieved in tunneling hot electron amplifiers and in the understanding of hot electron transport in the work funded by the contract and carried out by M. Heiblum and his co-workers. The results of this work are described in detail in nine papers that have been published in the open literature. (These papers are listed below as references 1-9 and copies of them are attached.) This report summarizes the principal results. There are three aspects of the work in which the results are particularly noteworthy: the demonstration of the first hot hole tunneling transistor and its use to study hot hole transport in GaAs; the successful fabrication of a hot electron 'THETA' transistor with a pseudomorphic InGaAs base which allowed high transistor gains (beta approx. = 30) to be achieved; and the conception and successful fabrication of a lateral hot electron device and its use to investigate ballistic, hot electron transport in a 2-dimensional electron gas in GaAs.

Kircher, C. J.

1993-10-01

138

Composite hot drape forming  

NASA Astrophysics Data System (ADS)

This program was initiated to replace labor-intensive ply-by-ply layup of composite I-beam posts and angle stiffeners used in the Space Station Freedom (SSF) rack structure. Hot drape forming (HDF) has been successfully implemented by BCAG for 777 composite I-stringers and by Bell Helicopter/Textron for the V-22 I-stingers. The two companies utilize two vastly different approaches to the I-beam fabrication process. A drape down process is used by Bell Helicopter where the compacted ply charge is placed on top of a forming mandrel and heated. When the heated ply charge reached a set temperature, vacuum pressure is applied and the plies are formed over the mandrel. The BCAG 777 process utilizes an inverted forming process where the ply stack is placed on a forming table and the mandrel is inverted and placed upon the ply stack. A heating and vacuum bladder underneath the ply stack form the play stack up onto the mandrels after reaching the temperature setpoint. Both methods have their advantages, but the drape down process was selected for SSF because it was more versatile and could be fabricated from readily available components.

Ott, Thomas

1994-02-01

139

Saturn's Hot Spot  

NASA Technical Reports Server (NTRS)

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

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

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

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

2005-01-01

140

Composite hot drape forming  

NASA Technical Reports Server (NTRS)

This program was initiated to replace labor-intensive ply-by-ply layup of composite I-beam posts and angle stiffeners used in the Space Station Freedom (SSF) rack structure. Hot drape forming (HDF) has been successfully implemented by BCAG for 777 composite I-stringers and by Bell Helicopter/Textron for the V-22 I-stingers. The two companies utilize two vastly different approaches to the I-beam fabrication process. A drape down process is used by Bell Helicopter where the compacted ply charge is placed on top of a forming mandrel and heated. When the heated ply charge reached a set temperature, vacuum pressure is applied and the plies are formed over the mandrel. The BCAG 777 process utilizes an inverted forming process where the ply stack is placed on a forming table and the mandrel is inverted and placed upon the ply stack. A heating and vacuum bladder underneath the ply stack form the play stack up onto the mandrels after reaching the temperature setpoint. Both methods have their advantages, but the drape down process was selected for SSF because it was more versatile and could be fabricated from readily available components.

Ott, Thomas

1994-01-01

141

Hot Spot Cosmic Accelerators  

NASA Astrophysics Data System (ADS)

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

2002-11-01

142

Neptune's 'Hot' South Pole  

NASA Technical Reports Server (NTRS)

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

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

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

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

2007-01-01

143

HOT STARS WITH HOT JUPITERS HAVE HIGH OBLIQUITIES  

SciTech Connect

We show that stars with transiting planets for which the stellar obliquity is large are preferentially hot (T{sub eff} > 6250 K). This could explain why small obliquities were observed in the earliest measurements, which focused on relatively cool stars drawn from Doppler surveys, as opposed to hotter stars that emerged more recently from transit surveys. The observed trend could be due to differences in planet formation and migration around stars of varying mass. Alternatively, we speculate that hot-Jupiter systems begin with a wide range of obliquities, but the photospheres of cool stars realign with the orbits due to tidal dissipation in their convective zones, while hot stars cannot realign because of their thinner convective zones. This in turn would suggest that hot Jupiters originate from few-body gravitational dynamics and that disk migration plays at most a supporting role.

Winn, Joshua N.; Albrecht, Simon [Department of Physics, Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Fabrycky, Daniel [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Johnson, John Asher [Department of Astrophysics, NASA Exoplanet Science Institute, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States)

2010-08-01

144

Hot melt adhesive attachment pad  

NASA Technical Reports Server (NTRS)

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.

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

145

Red-Hot Saturn  

NASA Technical Reports Server (NTRS)

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

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

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

2005-01-01

146

Hot Melt Traffic Marking Materials.  

National Technical Information Service (NTIS)

Extraordinary durability and quick-setting characteristics have firmly established hot thermoplastic as a preferred material for urban ccross-walk delineation. However, its highway use for center striping has been hampered by high application costs and so...

W. R. Tooke

1968-01-01

147

Hot Melt Adhesive Attachment Pad.  

National Technical Information Service (NTIS)

The invention relates to a hot melt adhesive attachment pad for releasably securing distinct elements together and particularly useful in the construction industry or a spatial vacuum environment. The attachment pad consists primarily of a cloth selective...

R. L. Fox A. W. Frizzill B. D. Little D. J. Progar R. H. Coultrip

1983-01-01

148

Do scientists trace hot topics?  

NASA Astrophysics Data System (ADS)

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

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

2013-07-01

149

Advanced hot gas filter development.  

National Technical Information Service (NTIS)

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 fil...

E. S. Connolly G. D. Forsythe

1998-01-01

150

Advanced Hot Gas Filter Development.  

National Technical Information Service (NTIS)

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 micros...

R. A. Wagner

1998-01-01

151

Delivering hot water more economically.  

PubMed

Jonathan Jones, European product manager at Tyco Thermal Controls, explains the economic and other benefits of using electrically trace-heated single pipe distribution, in place of the more "traditional" flow and return system, for hot water supply. PMID:20527595

Jones, Jonathan

2010-05-01

152

Morpheus Lander Hot Fire Test  

NASA Video Gallery

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

153

Hot Tub Rash (Pseudomonas Folliculitis)  

MedlinePLUS

... follicles, these bumps tend to be itchy or tender. Hot tub rash typically arises within 1–4 ... fever, headache, sore throat, and fatigue. Swollen and tender lymph nodes (glands that help produce antibodies, special ...

154

Hot-Water Reaction Turbine.  

National Technical Information Service (NTIS)

Under simplifying assumptions, the operation of a hot-water reaction turbine, based on the principle of Segner's waterwheel, was investigated theoretically. Its application as a temporary drive for a high-power generator and the possibilities for regulati...

J. Reinkenhof

1964-01-01

155

Concentrator Hot-Spot Testing. Phase 1.  

National Technical Information Service (NTIS)

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 ...

C. C. Gonzalez

1987-01-01

156

Hot Deformation Behavior of Incoloy 901 Through Hot Tensile Testing  

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

157

The masses of hot subdwarfs  

NASA Astrophysics Data System (ADS)

Context: Masses are a fundamental parameter, but they are not well known for most hot subdwarfs. In general, the mass of a hot subdwarf is derived with asteroseismology or dynamical methods, for which it is often difficult to obtain the necessary data from observations. Aims: We intend to find an approach to deriving the masses of hot subdwarfs from observational data in the literature. Methods: We presented full evolutionary calculations for hot subdwarfs in a wide mass range (0.33 M_? to 1.4 M_?) for a Population I metallicity of Z = 0.02, and obtained a relation between Mp and log ({T_eff^4}/{g}), where M_p, T_eff, and g are the most probable mass, effective temperature, and gravity. This relation is used to study the masses of some observed hot subdwarfs. Results: We proposed a method of determining the masses of hot subdwarfs. Using this method, we studied the masses of hot subdwarfs from the ESO supernova Ia progenitor survey and Hamburg quasar survey. The study shows that most of subdwarf B stars have masses between 0.42 and 0.54 M_?, whilst most sdO stars are in the range 0.40 ˜ 0.55 M_?. Comparing our study to the theoretical mass distributions of Han et al. (2003, MNRAS, 341, 669), we found that sdO stars with mass less than 0.5 M_? may evolve from sdB stars, whilst most high-mass(>0.5 M_?) sdO stars result from mergers directly.

Zhang, X.; Chen, X.; Han, Z.

2009-09-01

158

Hot Jupiter Magnetospheres  

NASA Astrophysics Data System (ADS)

The upper atmospheres of close-in gas giant exoplanets ("hot Jupiters") are subjected to intense heating and tidal forces from their parent stars. The atomic (H) and ionized (H+) hydrogen layers are sufficiently rarefied that magnetic pressure may dominate gas pressure for expected planetary magnetic field strength. We examine the structure of the magnetosphere using a 3D isothermal magnetohydrodynamic model that includes a static "dead zone" near the magnetic equator containing gas confined by the magnetic field, a "wind zone" outside the magnetic equator in which thermal pressure gradients and the magneto-centrifugal-tidal effect give rise to a transonic outflow, and a region near the poles where sufficiently strong tidal forces may suppress transonic outflow. Using dipole field geometry, we estimate the size of the dead zone to be several to tens of planetary radii for a range of parameters. Tides decrease the size of the dead zone, while allowing the gas density to increase outward where the effective gravity is outward. In the wind zone, the rapid decrease of density beyond the sonic point leads to smaller densities relative to the neighboring dead zone, which is in hydrostatic equilibrium. To understand the appropriate base conditions for the 3D isothermal model, we compute a simple 1D thermal model in which photoelectric heating from the stellar Lyman continuum is balanced by collisionally excited Ly? cooling. This 1D model exhibits a H layer with temperature T ~= 5000-10,000 K down to a pressure P ~ 10-100 nbar. Using the 3D isothermal model, we compute maps of the H column density as well as the Ly? transmission spectra for parameters appropriate for HD 209458b. Line-integrated transit depths sime5%-10% can be achieved for the above base conditions, in agreement with the results of Koskinen et al. A deep, warm H layer results in a higher mass-loss rate relative to that for a more shallow layer, roughly in proportion to the base pressure. Strong magnetic fields have the effect of increasing the transit signal while decreasing the mass loss, due to higher covering fraction and density of the dead zone. Absorption due to bulk fluid velocity is negligible at linewidths gsim100 km s-1 from line center. In our model, most of the transit signal arises from magnetically confined gas, some of which may be outside the L1 equipotential. Hence, the presence of gas outside the L1 equipotential does not directly imply mass loss. We verify a posteriori that particle mean free paths and ion-neutral drift are small in the region of interest in the atmosphere, and that flux freezing is a good approximation. We suggest that resonant scattering of Ly? by the magnetosphere may be observable due to the Doppler shift from the planet's orbital motion, and may provide a complementary probe of the magnetosphere. Lastly, we discuss the domain of applicability for the magnetic wind model described in this paper as well as the Roche-lobe overflow model.

Trammell, George B.; Arras, Phil; Li, Zhi-Yun

2011-02-01

159

Hot Alps (Invited)  

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

160

Promethus Hot Leg Piping Concept  

SciTech Connect

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.

AM Girbik; PA Dilorenzo

2006-01-24

161

Archaeal Nitrification in Hot Springs  

NASA Astrophysics Data System (ADS)

Biological nitrification, i.e. the aerobic conversion of ammonia to nitrate via nitrite, is a major component of the global nitrogen cycle. Until recently, it was thought that the ability to aerobically oxidize ammonia was confined to bacteria of the phylum Proteobacteria. However, it has recently been shown that Archaea of the phylum Crenarchaeota are also capable of ammonia oxidation. As many Crenarchaeota are thermophilic or hyperthermophilic, and at least some of them are capable of ammonia oxidation we speculated on the existence of (hyper)thermophilic ammonia-oxidizing archaea (AOA). Using PCR primers specifically targeting the archaeal ammonia monooxygenase (amoA) gene, we were indeed able to confirm the presence of such organisms in several hot springs in Reykjadalur, Iceland. These hot springs exhibited temperatures well above 80 °C and pH values ranging from 2.0 to 4.5. To proof that nitrification actually took place under these extreme conditions, we measured gross nitrification rates by the isotope pool dilution method; we added 15N-labelled nitrate to the mud and followed the dilution of the label by nitrate production from ammonium either in situ (incubation in the hot spring) or under controlled conditions in the laboratory (at 80 °C). The nitrification rates in the hot springs ranged from 0.79 to 2.22 mg nitrate-N per L of mud and day. Controls, in which microorganisms were killed before the incubations, demonstrated that the nitrification was of biological origin. Addition of ammonium increased the gross nitrification rate approximately 3-fold, indicating that the nitrification was ammonium limited under the conditions used. Collectively, our study provides evidence that (1) AOA are present in hot springs and (2) that they are actively nitrifying. These findings have major implications for our understanding of nitrogen cycling of hot environments.

Richter, A.; Daims, H.; Reigstad, L.; Wanek, W.; Wagner, M.; Schleper, C.

2006-12-01

162

Hot conditioning equipment conceptual design report  

SciTech Connect

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

Bradshaw, F.W., Westinghouse Hanford

1996-08-06

163

Hot Gas Halos in Galaxies  

NASA Astrophysics Data System (ADS)

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

Mulchaey, John S.; Jeltema, Tesla E.

2010-06-01

164

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

PubMed

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

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

2005-12-01

165

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

PubMed Central

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

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

2005-01-01

166

TRUEX hot demonstration. Final report  

Microsoft Academic Search

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

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

1990-01-01

167

Hot Isostatic Pressing of Ceramics.  

National Technical Information Service (NTIS)

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...

K. Honma

1985-01-01

168

Treatment of hot tar burns  

PubMed Central

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

Bose, B.; Tredget, T.

1982-01-01

169

Power generation from hot brines  

Microsoft Academic Search

Hot fluid which may contain salts and other dissolved minerals is passed through a direct contact heat exchanger in heat exchange relationship with a working fluid that has a specific gravity sufficiently below the specific gravity of the fluid so that it may pass from the bottom to the top of the heat exchanger chamber in contact with the fluid.

Sheinbaum

1976-01-01

170

Hot Springs: Valley of Vapors.  

National Technical Information Service (NTIS)

Best known for its 47 mineral-rich hot springs by those seeking relief in the ancient tradition of thermal bathing, This Arkansas mecca has been visited first by Indians seeking mudholes and later by turn-of-the century visitors coming to enjoy the plush ...

1994-01-01

171

Tribology of hot metal forming  

Microsoft Academic Search

Many aspects of the tribology of hot metal forming are poorly understood. This leads to difficulties when modelling the forming operations to develop process improvements. It also handicaps the development of new tool materials, since the operating conditions with which they will have to cope are not fully described. Several key issues in friction, heat transfer, lubrication, wear and fatigue

J. H Beynon

1998-01-01

172

Hot, Cold, and Really Cold.  

ERIC Educational Resources Information Center

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

Leyden, Michael

1997-01-01

173

Patterns of hot spot volcanism  

Microsoft Academic Search

The aim of this paper is to identify the characteristic features, in terms of geophysically measured parameters, of the hot spot sites over the earth's surface. We use a pattern recognition approach and a statistical algorithm which allows us to work at a given significance level. We use the following parameters: the absolute plate velocity of the site, minimum distance

Warner Marzocchi; Francesco Mulargia

1993-01-01

174

Upside's Hot 100 Awards: 1999  

NSDL National Science Digital Library

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

175

Solar hot water heating system  

Microsoft Academic Search

A solar hot water heating system, utilizing preferably a gas-liquid, phase change medium in the collector, employs one heating and storage tank above the collector and a preheating and storage tank below the first tank and preferably also below the collector. A cold water source feeds the inlet of the preheating tank which has its outlet connected to the inlet

1981-01-01

176

Hot Issues at Community Colleges  

NSDL National Science Digital Library

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

2010-06-09

177

Detection of Hot Halo Gets Theory Out of Hot Water  

NASA Astrophysics Data System (ADS)

Scientists using NASA's Chandra X-ray Observatory have detected an extensive halo of hot gas around a quiescent spiral galaxy. This discovery is evidence that galaxies like our Milky Way are still accumulating matter from the gradual inflow of intergalactic gas. "What we are likely witnessing here is the ongoing galaxy formation process," said Kristian Pedersen of the University of Copenhagen, Denmark, and lead author of a report on the discovery. Chandra observations show that the hot halo extends more than 60,000 light years on either side of the disk of the galaxy known as NGC 5746. The detection of such a large halo alleviates a long-standing problem for the theory of galaxy formation. Spiral galaxies are thought to form from enormous clouds of intergalactic gas that collapse to form giant, spinning disks of stars and gas. Chandra X-ray Image of NGC 5746 Chandra X-ray Image of NGC 5746 One prediction of this theory is that large spiral galaxies should be immersed in halos of hot gas left over from the galaxy formation process. Hot gas has been detected around spiral galaxies in which vigorous star formation is ejecting matter from the galaxy, but until now hot halos due to infall of intergalactic matter have not been detected. "Our observations solve the mystery of the missing hot halos around spiral galaxies," said Pedersen. "The halos exist, but are so faint that an extremely sensitive telescope such as Chandra is needed to detect them." DSS Optical Image of NGC 5746 DSS Optical Image of NGC 5746 NGC 5746 is a massive spiral galaxy about a 100 million light years from Earth. Its disk of stars and gas is viewed almost edge-on. The galaxy shows no signs of unusual star formation, or energetic activity from its nuclear region, making it unlikely that the hot halo is produced by gas flowing out of the galaxy. "We targeted NGC 5746 because we thought its distance and orientation would give us the best chance to detect a hot halo caused by the infall of intergalactic gas," said Jesper Rasmussen of the University of Birmingham, United Kingdom and a coauthor of the report. "What we found is in good agreement with computer simulations in which galaxies are built up gradually from the merger of smaller clouds of hot gas and dark matter." The computer simulations were done by Jesper Sommer-Larsen (also a coauthor of the report) and collaborators at the University of Copenhagen. The paper describing these results will be published in the April issue of the journal New Astronomy. Other researchers on this project were Sune Toft, Yale University; Andrew Benson, University of Oxford, United Kingdom; and Richard Bower, University of Durham, United Kingdom. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. http://chandra.harvard.edu and http://chandra.nasa.gov

2006-02-01

178

Is Coffee Aggravating Your Hot Flashes?  

MedlinePLUS

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

179

Solar Domestic Hot Water Systems. Final Report.  

National Technical Information Service (NTIS)

This report deals with the application of an appropriate technology, namely, solar domestic hot water heaters in a very specialized milieu within the larger society. In bringing solar domestic hot water to the Alamo Navajo Reservation this unique project ...

1984-01-01

180

Emissions from Hot-Dip Galvanizing Processes.  

National Technical Information Service (NTIS)

A literature review and source tests were performed in order to accurately characterize emissions from hot-dip galvanizing processes. Particulate emission data from seventeen source tests on hot-dip galvanizing plants were considered relevant in developin...

P. J. Drivas

1976-01-01

181

Hyperthermia: Too Hot for Your Health  

MedlinePLUS

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

182

Hot electron dynamics in device structures  

NASA Astrophysics Data System (ADS)

The transport properties of non-equilibrium electrons in GaAs Hot Electron and Heterojunction Bipolar Transistors has been successfully probed using hot electron spectroscopy. In this article I will review the interaction of hot electrons with both a cool electron gas and a cool hole gas. In addition to hot electron cooling the graded gap bipolar transistor will also be discussed since it enables us to study electron heating in an electric field.

Hayes, J. R.

1988-04-01

183

Diamond film by hot filament CVD method  

NASA Technical Reports Server (NTRS)

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

Hirose, Y.

1988-01-01

184

Hot Plate provides ``free`` water heating  

Microsoft Academic Search

The Hot Plate is a unique heat recovery unit that uses waste heat from residential and small commercial air-conditioning and refrigeration equipment to provide ``free`` hot water. It also can reduce summer peak load by displacing the need for conventional water heating on hot days when cooling equipment is running at full capacity. It is most economic in applications where

Stickney

1993-01-01

185

Hot sample archiving. Revision 3  

SciTech Connect

This Engineering Study revision evaluated the alternatives to provide tank waste characterization analytical samples for a time period as recommended by the Tank Waste Remediation Systems Program. The recommendation of storing 40 ml segment samples for a period of approximately 18 months (6 months past the approval date of the Tank Characterization Report) and then composite the core segment material in 125 ml containers for a period of five years. The study considers storage at 222-S facility. It was determined that the critical storage problem was in the hot cell area. The 40 ml sample container has enough material for approximately 3 times the required amount for a complete laboratory re-analysis. The final result is that 222-S can meet the sample archive storage requirements. During the 100% capture rate the capacity is exceeded in the hot cell area, but quick, inexpensive options are available to meet the requirements.

McVey, C.B.

1995-05-26

186

Hot atom chemistry and radiopharmaceuticals  

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

187

Hot isostatic pressing of ceramics  

NASA Technical Reports Server (NTRS)

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

Honma, K.

1985-01-01

188

Noise Generation in Hot Jets  

NASA Technical Reports Server (NTRS)

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

Khavaran, Abbas; Kenzakowski, Donald C.

2007-01-01

189

Silicon Hot-Electron Bolometers  

NASA Technical Reports Server (NTRS)

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

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

2004-01-01

190

Lightning Hot Spots in Canada  

NSDL National Science Digital Library

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

191

Hot and Cold Ideal Gases  

NSDL National Science Digital Library

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

Timberlake, Todd

2010-07-01

192

Hot gas engine heater head  

DOEpatents

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

Berntell, John O. (Staffanstorp, SE)

1983-01-01

193

Hot Accretion with Saturated Conduction  

NASA Astrophysics Data System (ADS)

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.

Menou, Kristen

2005-07-01

194

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

Microsoft Academic Search

Seafloor beneath hot-spot-produced seamounts have crustal flow lines that intersect at the hot spot locations, provided there is more than one stage rotation and that hot spots are stationary. Convolving seamount shapes with their associated flow lines yields an image of cumulative volcano amplitude (CVA). We call the technique of correlating local CVA maxima with hot spot locations “hot-spotting”. This

Paul Wessel; Loren W. Kroenke

1998-01-01

195

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

Microsoft Academic Search

Seafloor beneath hot-spot-produced seamounts have crustal flow lines that intersect at the hot spot locations, provided there is more than one stage rotation and that hot spots are stationary. Convolving seamount shapes with their associated flow lines yields an image of cumulative volcano amplitude (CVA). We call the technique of correlating local CVA maxima with hot spot locations ``hot-spotting.'' This

Paul Wessel; Loren W. Kroenke

1998-01-01

196

ESA uncovers Geminga's `hot spot'  

NASA Astrophysics Data System (ADS)

16 July 2004 Astronomers using ESA’s 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 Geminga’s 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 Geminga’s strong magnetic field, trail the neutron star as it moves about in space. Panel (b) shows how electrically charged particles interact with Geminga’s magnetic field. For example, if electrons (blue) are kicked out by the star, positrons (in red) hit the star’s magnetic poles like in an ‘own goal’. Panel (c) illustrates the size of Geminga’s magnetic field (blue) compared to that of the star itself at the centre (purple). The magnetic field is tilted with respect to Geminga’s 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 Geminga’s 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 Geminga’s magnetic field. For example, if electrons (blue) are kicked out by the star, positrons (red) hit the star’s 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 Geminga’s magnetic field (blue) compared to that of the star itself at the centre (purple). The magnetic field is tilted with respect to Geminga’s 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 Earth’s. 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. ESA’s 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 Geminga’s tails are formed by electrons or by their twin particles with an opposite e

2004-07-01

197

Slip and Dilation Tendency Anlysis of Neal Hot Springs Geothermal Area  

SciTech Connect

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

James E. Faulds

2013-12-31

198

Slip and Dilation Tendency Anlysis of Neal Hot Springs Geothermal Area  

DOE Data Explorer

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

James E. Faulds

199

Assessment of hot gas contaminant control  

SciTech Connect

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.

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

1996-12-31

200

Hot Flow Anomalies at Venus  

NASA Technical Reports Server (NTRS)

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

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

2012-01-01

201

Atmospheric Circulation of Hot Jupiters  

NASA Astrophysics Data System (ADS)

Roughly 40% of currently known extrasolar giant planets have orbital distances of 0.2 AU or less and are dubbed ``hot Jupiters'' because of their high effective temperatures (1000 K or more). Doppler techniques have yielded lower bounds on their masses, and the recent discovery that one such hot Jupiter (HD209458b) transits its parent star has provided estimates of radii and actual mass. More transit detections are sure to follow, and future detection of these objects in thermal and reflected light may allow observational estimates of albedo, effective temperature, and perhaps day-night temperature differences. Atmospheric dynamics will be required to explain these observations. The radius depends on the entropy of the (presumably convecting) interior, while the temperature at the emission-to-space level is set by thermal balance with the star. The two regions are connected by a statically stable layer whose properties depend on atmospheric dynamics, so the dynamical regime must be understood if the radius and effective temperature are to be explained simultaneously. Furthermore, day-night temperature differences are directly linked to dynamical timescales (and are probably 200 K or more). The circulation pattern also determine whether (and where) clouds exist, which influences the albedo and the depth to which stellar radiation penetrates. Here we present detailed dynamical simulations using the Explicit Planetary Isentropic Coordinate (EPIC) model of Dowling et al. (1998) to constrain the probable circulation regimes of hot Jupiters (focusing on HD209458b, with radius 1.4 RJ, mass 0.7 MJ, and period of 3.5 days). The simulations assume a synchronously rotating gas-giant (as expected for hot Jupiters) and parameterize the intense heating and cooling using a simple relaxation to a radiative equilibrium profile. The goals are to determine the number and speed of the jets, the day-night temperature differences, and regions of upwelling and downwelling (which is relevant for cloud formation). We will compare the simulation results to simple order-of-magnitude estimates, which suggest the importance of planetary rotation, the existence of several jets, and horiztonal winds of 200 m/sec or more.

Showman, A. P.; Guillot, T.

2000-10-01

202

Modeling Hot and Cold Planets  

NSDL National Science Digital Library

These are the student pages for a three part lesson plan in which students investigate a physical model representing a cold and a hot planet. In the second part, the students interact with a computer model that simulates extreme conditions on some planets, and in the third part they will utilize a data source from the internet to determine the average temperature of the earth and specify the characteristics of a sampling necessary to achieve an accurate average. The lesson plan includes an overview, learning objectives, a list of materials, procedure, data analysis, and worksheets. Teachers' notes are also included.

203

Coral Reefs in Hot Water  

NSDL National Science Digital Library

In this activity, student teams identify the locations of coral reefs around the world, examine infrared satellite images of the Earth, and research the impacts that are threatening the survival of coral reefs. Each team creates a short oral presentation describing the coral reef they have researched. Students then plot on a composite map the locations where coral bleaching is occurring. Student worksheets, a teacher guide, and assessment rubric are included. This activity is part of Coastal Areas: Coral Reefs in Hot Water, part of the lesson series, The Potential Consequences of Climate Variability and Change.

204

Subminiature Hot-Wire Probes  

NASA Technical Reports Server (NTRS)

Class of improved subminiature hot-wire flow-measuring probes developed. Smaller sizes yield improved resolution in measurements of practical aerodynamic flows. Probe made in one-wire, two-perpendicular-wire, and three-perpendicular-wire version for measurement of one, two, or all three components of flow. Oriented and positioned on micromanipulator stage and viewed under microscope during fabrication. Tested by taking measurements in constant-pressure turbulent boundary layer. New probes give improved measurements of turbulence quantities near surfaces and anisotropies of flows strongly influence relative errors caused by phenomena related to spatial resolution.

Westphal, R. V.; Lemos, F. R.; Ligrani, P. M.

1989-01-01

205

That's Hot! Robot Brain Programming  

NSDL National Science Digital Library

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

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

206

HotBits: Genuine Random Numbers  

NSDL National Science Digital Library

HotBits is a genuine random number generator powered by radioactive decay. Simply click the "Request HotBits" link, and specify how many bytes you would like (up to 2048) and in what form you prefer them. Hexadecimal returns numbers and letters, while C language returns integers. Then click the "Get HotBits" button, and your random numbers will appear on the screen.

Walker, John

2009-10-21

207

Determination of material properties for hot hydroforming  

Microsoft Academic Search

For the process design of hydroforming in the “hot” temperature range, reliable data are necessary to describe the material\\u000a behaviour at elevated temperatures under the occurring loads of hot hydroforming processes. State-of-the-art technologies\\u000a for the investigation of material behaviour, like uniaxial tensile tests or hydraulic bulge tests, do not provide enough similarity\\u000a with the process of hot hydroforming. This paper

D. Elsenheimer; P. Groche

2009-01-01

208

Biofilm formation in a hot water system.  

PubMed

The biofilm formation rate was measured in situ in a hot water system in an apartment building by specially designed sampling equipment, and the net growth of the suspended bacteria was measured by incubation of water samples with the indigeneous bacteria. The biofilm formation rate reached a higher level in the hot water distribution system (2.1 d(-1) to 2.3 d(-1)) than in the hot water tank (1.4 d(-1) to 2.2 d(-1)) indicating an important area for surface associated growth. The net growth rate of the suspended bacteria measured in hot water from the top, middle and bottom of the hot water tank, in the sludge, or in the water from the distribution system was negligible. This indicated that bacterial growth took place on the inner surfaces in the hot water system and biofilm formation and detachment of bacteria could account for most of the suspended bacteria actually measured in hot water. Therefore, attempts to reduce the number of bacteria in a hot water system have to include the distribution system as well as the hot water tank. PMID:12448457

Bagh, L K; Albrechtsen, H J; Arvin, E; Ovesen, K

2002-01-01

209

Hot spot and trench volcano separations  

NASA Technical Reports Server (NTRS)

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.

Lingenfelter, R. E.; Schubert, G.

1974-01-01

210

Hot electron and hot hole degradation of UHV\\/CVD SiGe HBT's  

Microsoft Academic Search

We investigate the degradation in current gain and low-frequency noise of SiGe HBT's under reverse emitter-base stress due to hot electrons (forward-collector stress) and hot holes (open-collector stress). Contrary to previous assumptions we show that hot electrons and hot holes with the same kinetic energy generate different amounts of traps and hence have a different impact on device degradation. These

Usha Gogineni; John D. Cressler; Guofu Niu; David L. Harame

2000-01-01

211

HotSpot Wizard: a web server for identification of hot spots in protein engineering  

Microsoft Academic Search

HotSpot Wizard is a web server for automatic identification of 'hot spots' for engineering of sub- strate specificity, activity or enantioselectivity of enzymes and for annotation of protein structures. The web server implements the protein engineering protocol, which targets evolutionarily variable amino acid positions located in the active site or lining the access tunnels. The 'hot spots' for muta- genesis

Antonin Pavelka; Eva Chovancova; Jirí Damborský

2009-01-01

212

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

Microsoft Academic Search

Hot spots and the seamounts produced by them provide both geometric and temporal evidence for changes in absolute plate motion. The main limitation in using hot-spot-produced seamounts in plate tectonic reconstructions arises from the multiple sources of error and ambiguity that plague radiometric age estimates. In particular, unless the hot spot has maintained a steady and voluminous flux rate over

Paul Wessel; Loren W Kroenke

1998-01-01

213

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

Microsoft Academic Search

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

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

1997-01-01

214

A two-dimensional hot-spot mixer model for phonon-cooled hot electron bolometers  

Microsoft Academic Search

A hot spot model for superconducting hot electron bolometers is presented based on a two-dimensional heat transport equation for electrons and phonons including heat trapping due to quasiparticle bandgap gradients. Skin effect concentrates the RF heating in lateral regions of the bridge and the bias current in the center. A reduction in conversion gain compared to a one-dimensional hot spot

Harald F. Merkel; Pourya Khosropanah; Serguei Cherednichenko; K. S. Yngvesson; A. Adam; E. I. Kollberg

2001-01-01

215

Ceramic hot-gas filter  

DOEpatents

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.

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

1999-05-11

216

TRUEX hot demonstration. Final report  

SciTech Connect

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.

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

1990-04-01

217

Ceramic hot-gas filter  

DOEpatents

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.

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

218

THz semiconductor hot electron bolometer  

NASA Astrophysics Data System (ADS)

A model of fast Semiconductor Hot Electron Bolometer (SHEB) is developed. In this bolometer radiation heats only electrons in bipolar semiconductor without inertial lattice heating. For conditions proposed, such heating changes both generation and recombination processes, that leads to the electron and hole concentration decreases. This and the electron mobility decrease, because of their heating, cause the semiconductor resistance rise, which is used for the output signal creation. Semiconductors with the high conductivity, mobility and electron energy relaxation time are important for the SHEB manufacturing. Narrow-gap semiconductors have such properties, and therefore the bolometer model is constructed for them. According to this model the SHEB on base of Hg0.8Cd 0.2Te at temperature of 77 K can have detectivity of (0.3-2)107 cmHz1/2/W for radiation frequency (0.01-1.5) THz.

Dobrovolsky, V. N.; Sizov, F. F.

2006-03-01

219

Eclipse Mapping of Hot Jupiters  

NASA Astrophysics Data System (ADS)

In principle, the photospheric temperature structure of an extrasolar planet can be resolved by measuring the shape of the infrared light curve as the planet passes into secondary eclipse behind its parent star. We consider the feasibility of using this method to constrain current atmospheric models of tidally-locked hot Jupiters, which experience extreme heating on their permanent daysides. We find that the Spitzer Space Telescope lacks the sensitivity necessary to differentiate between even the most disparate models in a reasonable number of eclipse measurements. However, the upcoming James Webb Space Telescope will be an incredible asset, with enough sensitivity to distinguish detailed temperature structure in one or a few eclipses. This work was supported by NASA grant NNG06GF55G.

Rauscher, Emily; Menou, K.; Seager, S.; Deming, D.

2006-12-01

220

Electrical phenomena during Hot Swap events  

Microsoft Academic Search

The exchange of a computer system's components during operation can be accomplished by the so called Hot Swap technology. This technology makes it possible to contin- uously run a computer system without the necessity of a shutdown for maintenance purposes, e.g. upgrading of a network adapter. Thus the overall uptime of a system can be drastically increased. The Hot Swap

Carsten Trinitis; Wolfgang Karl; Markus Leberecht

2000-01-01

221

Recharging "Hot-Melt" Adhesive Film  

NASA Technical Reports Server (NTRS)

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.

Progar, D. J.

1983-01-01

222

Hot Hollow Cathode Plating Process Upgrade Proposal.  

National Technical Information Service (NTIS)

The Vacuum Operations Group has designed and built three vacuum coating systems that use a hot hollow cathode source. Highly adherent silver coatings applied with the hot hollow cathode source on joint interfaces are being used to make solid-state bonds b...

J. A. Arluck W. N. Massey

1979-01-01

223

Hot-dry-rock feasibility study  

SciTech Connect

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

Not Available

1981-08-01

224

Experimental Hot Mix Project Using Polymerized Asphalt.  

National Technical Information Service (NTIS)

The report compiles all the data involved in the production and construction of a hot mix overlay in Lee County, Project CSR 114-7-51, on US 290 through the city of Giddings. The hot mix ACP was produced with a polymerized asphalt. The report merely docum...

K. H. Hargett

1987-01-01

225

Variational Theory of Hot Dense Matter  

ERIC Educational Resources Information Center

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

Mukherjee, Abhishek

2009-01-01

226

Fabrication of lithium ceramics by hot pressing  

SciTech Connect

Controlled density LiA10/sub 2/, Li/sub 2/Zr0/sub 3/, Li/sub 4/SiO/sub 4/ and Li/sub 2/O pellets were fabricated by hot pressing for irradiation testing as candidate tritium breeding materials. Pellet specifications, characterization data, and procedures for hot pressing, pellet grinding and halide removal are discussed.

Wilson, C.N.

1982-03-01

227

Basics of Solar Heating & Hot Water Systems.  

ERIC Educational Resources Information Center

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

American Inst. of Architects, Washington, DC.

228

HotSpot Software Configuration Management Plan  

SciTech Connect

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

Walker, H; Homann, S G

2009-03-12

229

HotSpot Software Test Plan  

SciTech Connect

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

Walker, H; Homann, S G

2009-03-12

230

Hot-Air Ballooning in Physics Teaching.  

ERIC Educational Resources Information Center

Describes the modern hot-air balloon and the physics of ballooning. Proposes that students construct their own hot-air balloon and presents an experiment calculating the time needed for a balloon to rise to the ceiling of a gymnasium. (MDH)

Haugland, Ole Anton

1991-01-01

231

Suspended, hot-box solar collectors  

Microsoft Academic Search

The suspended, hot box solar collector is designed to provide approximately double area solar insolation on to a closed, truncated triangular structure which is double-glazed and insulated to collect and store solar heat energy for hot air space heating. Direct solar radiation is collected through sloped front, bottom and top double-glazed windows, with reflected solar rays received through the same

1980-01-01

232

Turbine Engine Hot Section Technology, 1985  

NASA Technical Reports Server (NTRS)

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

1985-01-01

233

Enabling Technologies for Ceramic Hot Section Components  

Microsoft Academic Search

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

Venkat Vedula; Tania Bhatia

2009-01-01

234

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

MedlinePLUS

Facts About “Hot Tub Rash” and “Swimmer’s 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 “swimmer’s ear.” This germ is ...

235

Hot gas defrost model development and validation  

Microsoft Academic Search

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

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

2005-01-01

236

Structure of Hot Flow Anomaly  

NASA Astrophysics Data System (ADS)

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

Shestakov, A.; Vaisberg, O. L.

2012-12-01

237

Equipment design guidelines for remote hot cell operations.  

National Technical Information Service (NTIS)

Hot cells provide a unique and challenging environment for designing remotely operated equipment. A typical hot cell is an isolated room used to protect operators from highly contaminated and radioactive equipment. Hot cells usually have thick reinforced ...

D. R. Wahlquist

1998-01-01

238

Hot Leg Piping Materials Issues  

SciTech Connect

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

V. Munne

2006-07-19

239

Iron Aluminide Hot Gas Filters  

SciTech Connect

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

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

1996-12-31

240

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

Code of Federal Regulations, 2010 CFR

...Definitions concerning commercial water heaters, hot water supply boilers, and...INDUSTRIAL EQUIPMENT Commercial Water Heaters, Hot Water Supply Boilers and...Definitions concerning commercial water heaters, hot water supply boilers,...

2009-01-01

241

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

Code of Federal Regulations, 2010 CFR

...Definitions concerning commercial water heaters, hot water supply boilers, and...INDUSTRIAL EQUIPMENT Commercial Water Heaters, Hot Water Supply Boilers and...Definitions concerning commercial water heaters, hot water supply boilers,...

2010-01-01

242

Ion acceleration by hot electrons in microclusters  

SciTech Connect

A self-consistent analytical description is presented for collisionless expansion of a fully ionized cluster with a two-component electron distribution. The problem is solved for an initial 'water-bag' distribution of hot electrons with no angular momentum, which reflects the mechanism of electron heating. This distribution evolves in time due to adiabatic cooling of hot electrons. The solution involves a cold core of the cluster, a thin double layer at the cluster edge, and a quasineutral flow with a rarefaction wave. The presented analysis predicts a substantial number of accelerated ions with energies greater than the cutoff energy of the initial distribution of the hot electrons.

Breizman, Boris N.; Arefiev, Alexey V. [Institute for Fusion Studies, University of Texas, Austin, Texas 78712 (United States)

2007-07-15

243

On the radii of hot strange stars  

NASA Astrophysics Data System (ADS)

The equilibrium states of hot strange stars are studied. The equation of state of hot strange quark matter is determined on the basis of the MIT bag model. It is shown that for hot strange quark stars the mass-central density and mass-radius relations do not depend on the central temperature if quarks are ultrarelativistic. For these relations the weight of the thermal energy is of fundamental significance. That explains the nature of change in the radius of a strange star when it cools down.

Alaverdyan, A. G.; Hajyan, G. S.

2014-03-01

244

Hot Jupiter Variability in Eclipse Depth  

NASA Astrophysics Data System (ADS)

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.

Rauscher, Emily; Menou, Kristen; Cho, James Y.-K.; Seager, Sara; Hansen, Bradley M. S.

2007-06-01

245

Moisture Absorption of Hot-Melt Coatings.  

National Technical Information Service (NTIS)

In order to understand the effects of certain properties of protective coating materials on corrosion protection, a study was made of these properties without the effects of corrosion present. The moisture absorption properties of various hot-melt coating...

C. E. Selander

1964-01-01

246

Hot Isostatic Pressing of Ceramic Powder Compacts.  

National Technical Information Service (NTIS)

The densification of aluminum oxide in hot isostatic pressing has been studied in detail. Methods for calculating maps of densification rate as function of temperature and applied pressure have been developed. A new mechanism, interface-reaction-controlle...

J. K. McCoy A. J. Markworth

1986-01-01

247

Hot Isostatic Pressing of Ceramic Powder Compacts.  

National Technical Information Service (NTIS)

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

J. K. McCoy R. R. Wills

1984-01-01

248

Wave Propagation in Inhomogeneous Isotropic Hot Plasmas.  

National Technical Information Service (NTIS)

The three dimensional coupled wave equations for the electromagnetic and the acoustic wave propagating in inhomogeneous, isotropic, hot plasma are derived from the linearized electro-magneto-plasma-gasdynamics (EMPGD) equations. The wave equations become ...

H. Unz

1965-01-01

249

High Temperature Vapor Phase Electrolysis (HOT ELLY).  

National Technical Information Service (NTIS)

The objective of the project HOT ELLY (phase 1) was the demonstration of the practicability of high temperature steam electrolysis on a laboratory scale. Starting from basic material studies the components (using sufficiently cheap raw materials), as well...

W. Donitz H. Hermeking I. Kirzmann A. Koch R. Rottenbacher

1982-01-01

250

High Temperature Water Vapor Electrolysis (HOT ELLY).  

National Technical Information Service (NTIS)

The objective of the project HOT ELLY (phase 1) was the demonstration of the practicability of high temperature water vapor electrolysis on a laboratory scale. Starting from basic material studies the components (using sufficiently cheap raw materials) as...

W. Doenitz H. Hermeking I. Kitzmann A. Koch R. Roettenbacher

1980-01-01

251

Hot wire anemometry in transonic flow  

NASA Technical Reports Server (NTRS)

The use of hot-wire anemometry for obtaining fluctuating data in transonic flows has been evaluated. From hot-wire heat loss correlations based on previous transonic data, the sensitivity coefficients for velocity, density, and total temperature fluctuations have been calculated for a wide range of test conditions and sensor parameters. For sensor Reynolds numbers greater than 20 and high sensor overheat ratios, the velocity sensitivity remains independent of Mach number and equal to the density sensitivity. These conclusions were verified by comparisons of predicted sensitivities with those from recent direct calibrations in transonic flows. Based on these results, techniques are presented to obtain meaningful measurements of fluctuating velocity, density, and Reynolds shear stress using hot-wire and hot-film anemometers. Examples of these measurements are presented for two transonic boundary layers.

Horstman, C. C.; Rose, W. C.

1975-01-01

252

Physiological aspects of menopausal hot flush.  

PubMed Central

Eighteen hot flushes experimenced by eight menopausal women were studied and compared with the effects of warming in six premenopausal women. The hot flushes were associated with an acute rise in skin temperature, peripheral vasodilatation, a transient increase in heart rate, fluctuations in the electrocardiographic (ECG) baseline, and a pronounced decrease in skin resistence. Although premenopausal women had greater maximum increases in skin temperature and peripheral vasodilatation, they showed a much smaller decrease in skin resistance and no changes in heart rate or ECG baseline. These findings suggest that the onset of the hot flush is associated with a sudden and transient increase in sympathetic drive. Further investigations may lead to the development of a more specific alternative to oestrogen for relieving menopausal hot flushes. Images p80-a

Sturdee, D W; Wilson, K A; Pipili, E; Crocker, A D

1978-01-01

253

Solar domestic and service hot water manual  

SciTech Connect

Focuses on cost-effective technology. Discusses several system types and related components, along with ways of combining them economically based on hot water (load) requirements, climate building configuration. Presents methods for load determination, equipment selection, and system performance estimation.

Not Available

1983-01-01

254

Design data brochure: Solar hot water system  

NASA Technical Reports Server (NTRS)

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.

1978-01-01

255

Residential Hot Water Solar Energy Storage Subsystems.  

National Technical Information Service (NTIS)

Low-cost, efficient, and practical hot water solar energy storage subsystems for heating and cooling of residences are discussed. Both new and innovative vessel materials and configurations are investigated, together with insulation materials. Storage sub...

E. E. Pickering

1976-01-01

256

Hot Wire Ignition of Pyrotechnic Materials.  

National Technical Information Service (NTIS)

The hot wire ignition of a pyrotechnic material is considered through the use of a mathematical model. A system dependent ''ignition temperature'' is obtained by observing the behavior of derivatives in the differential equation as ignition develops. It i...

A. B. Donaldson

1974-01-01

257

Toward Eclipse Mapping of Hot Jupiters  

NASA Astrophysics Data System (ADS)

Recent Spitzer infrared measurements of hot-Jupiter eclipses suggest that eclipse-mapping techniques could be used to spatially resolve the dayside photospheric emission of these planets using partial occultations. As a first step in this direction, we simulate ingress/egress light curves for three bright 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 nonparametric eclipse map inversions for hot Jupiters should be actively considered.

Rauscher, Emily; Menou, Kristen; Seager, Sara; Deming, Drake; Cho, James Y.-K.; Hansen, Bradley M. S.

2007-08-01

258

Hot Mix Asphalt Plants Stakeholders Opinions Report.  

National Technical Information Service (NTIS)

The United States Environmental Protection Agency (EPA) Source Measurement Technology Group (SMTG) and Emission Factors and Inventory Group (EFIG) are investigating the Hot Mix Asphalt industry to identify and quantify criteria and hazardous air pollutant...

R. Myers

2001-01-01

259

Hot Mix Asphalt Plants Emission Assessment Report.  

National Technical Information Service (NTIS)

This report presents an assessment of emissions from hot mix asphalt (HMA) manufacturing facilities. Included in the report is a description of the manufacturing process and the emissions associated with HMA production; the procedures for developing emiss...

2000-01-01

260

Prototype solar heating and hot water systems  

NASA Technical Reports Server (NTRS)

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.

1978-01-01

261

Hot-water-furnace supplemental heater  

Microsoft Academic Search

This patent describes a hot-water-furnace, supplemental water heater to be used with a furnace of the type having essentially parallel, vertically-oriented, multiple heating tubes surrounded by water for conveying combustion materials from a firebox to an exit area adjacent the multiple heating tubes. The hot-water furnace forms a flat support wall at the exit area. The supplemental water heater comprises:

1987-01-01

262

A hot-hole erasable memory cell  

Microsoft Academic Search

Electrical erasure of in-system memory chips has always been a desire for circuit operation. A novel technique which utilizes hot-hole injection in the snapback regime for memory erasure is described. This operation does not require a high-cost quartz lid or a special device structure. Although endurance characteristics are limited by channel hot-carrier-induced degradation, hundreds of WRITE and ERASE cycles can

Mong-Song Liang; Tien-Chiun Lee

1986-01-01

263

Electron scattering in hot-dense plasmas  

NASA Astrophysics Data System (ADS)

Hot-dense plasmas have direct industrial applications in inertial confinement fusion. We have used the convergent close-coupling (CCC) method to investigate electron scattering off hydrogen and helium atoms in a hot-dense weakly coupled (Debye) plasma. The Yukawa-type Debye-Hückel potential has been used to describe the plasma screening effects. Integrated excitation, total ionization and total cross sections have been calculated over a broad range of energies and various Debye lengths, D.

Zammit, Mark C.; Fursa, Dmitry V.; Bray, Igor

2012-11-01

264

The hot spot of vegetation canopies  

NASA Technical Reports Server (NTRS)

A conventional radiometer is used to identify the hot spot (the peak in reflected radiation in the retrosolar direction) of vegetation. A multiwavelength-band radiometer collected radiances on fully grown dense wheat and maize canopies on several clear sunny days. It is noted that the hot spot is difficult to detect in the near IR wavelengths because the shadows are much darker. In general, the retrosolar brightness is found to be higher for smaller sun polar angles than for larger angles.

Myneni, Ranga B.; Kanemasu, Edward T.

1988-01-01

265

Teaching Earth Science Using Hot Air Balloons  

NSDL National Science Digital Library

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

Kuhl, James; Shaffer, Karen

2008-01-01

266

Biofilm formation in a hot water system  

Microsoft Academic Search

The biofilm formation rate was measured in situ in a hot water system in an apartment building by specially designed sampling equipment, and the net growth of the suspended bacteria was measured by incubation of water samples with the indigeneous bacteria. The biofilm formation rate reached a higher level in the hot water distribution system (2.1 d-1 to 2.3 d-1)

L. K. Bagh; H.-J. Albrechtsen; E. Arvin; K. Ovesen

267

Toward Eclipse Mapping of Hot Jupiters  

Microsoft Academic Search

Recent Spitzer infrared measurements of hot-Jupiter eclipses suggest that eclipse-mapping techniques could be used to spatially resolve the dayside photospheric emission of these planets using partial occultations. As a first step in this direction, we simulate ingress\\/egress light curves for three bright eclipsing hot Jupiters and evaluate the degree to which parameterized photospheric emission models can be distinguished from each

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

2007-01-01

268

Sensitivity analysis of hot channel calculation methods  

Microsoft Academic Search

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

I. Panka; M. Telbisz

2007-01-01

269

Canopy hot-spot as crop identifier  

SciTech Connect

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

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

1986-05-01

270

ADVANCED HOT GAS FILTER DEVELOPMENT  

SciTech Connect

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.

RICHARD A. WAGNER

1998-09-04

271

The Effectiveness of Hot-deck Procedures in Small Samples.  

ERIC Educational Resources Information Center

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

Kaiser, Javaid

272

Relationship between hot springs and geothermal fields in Japan  

Microsoft Academic Search

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

Hemendra R. Acharya

1989-01-01

273

Physiological responses during continuous work in hot dry and hot humid environments in Indians  

NASA Astrophysics Data System (ADS)

Studies have been conducted on six young healthy heat acclimatised Indians to determine the physiological changes in prolonged continuous work in thermally neutral and in hot dry and hot humid environments. Physiological responses in maximal efforts i.e. Vo2 max, VE max and Cf max were noted. In addition, duration in continuous work at three sub-maximal rate of work in three simulated environments were also noted. Physiological responses like Vo2, VE and Cf were noted every 15 minutes of work. Besides these responses, rectal temperature (Tre), mean skin temperature (Ts) and mean sweat rate were also recorded during continuous work. Results indicated a significant decrease in maximum oxygen uptake capacity (Vo2 max) in heat with no change in maximum exercise ventilation (VE max) and maximum cardiac frequency. However, the fall in Vo2 max was more severe in the hot humid environment than in the hot dry climate. Cardiac frequency at fixed oxygen consumption of 1.0, 1.5 and 2.0 l/min was distinctly higher in the hot humid environment than in the hot dry and comfortable temperature. The duration in continuous physical effort in various grades of activities decreased in hot dry environment from that in the-comfortable climate and further decreased significantly in hot humid environment. The highest rate of sweating was observed during work in humid heat. The mean skin temperature (Ts) showed a fall in all the three rates of work in comfortable and hot dry conditions whereas in hot humid environment it showed a linear rise during the progress of work. The rectal temperature on the other hand maintained a near steady state while working at 65 and 82 watts in comfortable and hot dry environments but kept on rising during work in hot humid environment. At the highest work rate of 98 watts, the rectal temperature showed a steady increase even in the hot dry condition. It was thus concluded from the study that a hot humid climate imposes more constraints on the thermoregulatory system during work than in the hot dry condition because of less effective heat dissipation so resulting in reduced tolerance to work.

Sen Gupta, J.; Swamy, Y. V.; Pichan, G.; Dimri, G. P.

1984-06-01

274

Experiments with the hot list strategy  

SciTech Connect

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.

Wos, L.

1997-10-01

275

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

Microsoft Academic Search

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

Longyear

1980-01-01

276

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

277

Hot Plate provides ``free`` water heating  

SciTech Connect

The Hot Plate is a unique heat recovery unit that uses waste heat from residential and small commercial air-conditioning and refrigeration equipment to provide ``free`` hot water. It also can reduce summer peak load by displacing the need for conventional water heating on hot days when cooling equipment is running at full capacity. It is most economic in applications where the refrigeration compressor runs a lot, and in such cases yields a cost of saved energy as low as 1{cents} per kWh. Several dozen utilities have successfully promoted similar technologies, but the Hot Plate has several design features that set it apart from competing products. It has a compact, flat design that allows it to be installed below the water heater, providing a pedestal base for the tank to stand on. Most competing products are bulkier and must be installed next to the tank, taking up valuable storage space. The most unique feature of the Hot Plate, however, is that it is a simple, passive thermosyphon system that requires no pump, active valves, electric wiring, or controls, and is thus easier to install and requires almost no maintenance.

Stickney, B.L.

1993-12-31

278

Metamaterial perfect absorber based hot electron photodetection.  

PubMed

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

Li, Wei; Valentine, Jason

2014-06-11

279

Radiation Hydrodynamics of Hot Jupiter Atmospheres  

NASA Astrophysics Data System (ADS)

Radiative transfer in planetary atmospheres is usually treated in the static limit, i.e., neglecting atmospheric motions. We argue that hot Jupiter atmospheres, with possibly fast (sonic) wind speeds, may require a more strongly coupled treatment, formally in the regime of radiation hydrodynamics. To lowest order in v/c, relativistic Doppler shifts distort line profiles along optical paths with finite wind velocity gradients. This leads to flow-dependent deviations in the effective emission and absorption properties of the atmospheric medium. Evaluating the overall impact of these distortions on the radiative structure of a dynamic atmosphere is non-trivial. We present transmissivity and systematic equivalent width excess calculations which suggest possibly important consequences for radiation transport in hot Jupiter atmospheres. If winds are fast and bulk Doppler shifts are indeed important for the global radiative balance, accurate modeling and reliable data interpretation for hot Jupiter atmospheres may prove challenging: it would involve anisotropic and dynamic radiative transfer in a coupled radiation-hydrodynamical flow. On the bright side, it would also imply that the emergent properties of hot Jupiter atmospheres are more direct tracers of their atmospheric flows than is the case for solar system planets. Radiation hydrodynamics may also influence radiative transfer in other classes of hot exoplanetary atmospheres with fast winds.

Menou, Kristen; Rauscher, Emily

2010-04-01

280

Tests of fixity of the Indo-Atlantic hot spots relative to Pacific hot spots  

NASA Astrophysics Data System (ADS)

of inter-hot spot motion have been debated for decades. Herein we present updated predictions for the tracks of the Tristan da Cunha, Réunion, and Iceland hot spots assuming them to be fixed relative to Pacific hot spots. Uncertainties in Pacific hot spot rotations, which include uncertainties in the current locations of hot spots of 100-200 km, are combined with uncertainties in relative plate motions accumulated through the plate circuit to obtain the final uncertainty in the predicted positions (including uncertainties of 150-200 km in the current locations of the Indo-Atlantic hot spots). Improvements to reconstruction methods, to relative plate reconstructions, to age dates along the tracks, and to the geomagnetic reversal timescale lead to significant changes from prior results. When compared with the observed tracks, the predicted tracks indicate nominal rates of motion of only 2-6 mm a-1 of these Indo-Atlantic hot spots relative to Pacific hot spots over the past 48 Ma. Within the uncertainties, the rates range from no motion to rates as high as 8-13 mm a-1. For reconstructions prior to 48 Ma B.P., however, the apparent rates of inter-hot spot motion are much larger, 46-55 ± 20 mm a-1, if the motion occurred entirely between 68 Ma B.P. and 48 Ma B.P. Either hot spots moved rapidly before 48 Ma B.P., and slowed drastically at ? 48 Ma B.P., or global plate circuits through Antarctica become less reliable as one goes increasingly further into the past. Most paleomagnetic data favor the latter explanation.

Koivisto, Emilia A.; Andrews, David L.; Gordon, Richard G.

2014-01-01

281

Hot gas filter and system assembly  

DOEpatents

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.

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

1999-08-31

282

Constraining The Hot Jupiter Kozai Mechanism Connection  

NASA Astrophysics Data System (ADS)

We have performed a systematic analysis to search for long-term trends in the radial velocity residuals of more than 120 exoplanetary hosts from the California-Carnegie Planet Search team to confirm or constrain the role that the Kozai mechanism plays in causing the hot Jupiter pile-up (an excess of exoplanets with 3-4 d periods). These long-term linear trends are likely indicative of stellar or substellar companions that could have induced the known exoplanet to migrate to its present position via the Kozai mechanism. Preliminary results suggest that the frequency of long-term linear trends are statistically similar in the hot Jupiter and the rest of the exoplanetary sample, thus suggesting that Kozai migration is not responsible for the majority of hot Jupiters.

Croll, Bryce; Murray, N.; Marcy, G. W.; Wright, J. T.; Cumming, A.

2007-12-01

283

Seeded hot dark matter models with inflation  

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

284

Three-dimensional hydrodynamic hot-spot  

SciTech Connect

The basic processes in the shock initiation of heterogeneous explosives have been investigated theoretically using a model of a cube of nitromethane containing 91 cubic air holes. The interaction of a shock wave with a single air hole and a matrix of air holes in PETN, HMX, and TATB has been numerically modeled. The interaction of a shock wave with the density discontinuities, the resulting hot-spot formation and interaction, and the buildup to propagating detonation were computed using three-dimensional numerical Eulerian hydrodynamics with Arrhenius chemical reaction and accurate equations of state according to the hydrodynamic hot-spot model. The basic processes in the desensitization of a heterogeneous explosive by preshocking with a shock pressure too low to cause propagating detonation was numerically modeled. The basic differences between shock sensitive explosives such as PETN or HMX and shock insensitive explosives such as TATB or NQ may be described using the hydrodynamic hot-spot model.

Mader, C.L.

1984-01-01

285

Kepler constraints on planets near hot Jupiters  

PubMed Central

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

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

286

Kepler constraints on planets near hot Jupiters  

SciTech Connect

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

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

2012-05-01

287

Hot gas filter and system assembly  

DOEpatents

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.

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

288

Kepler constraints on planets near hot Jupiters.  

PubMed

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

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

2012-05-22

289

Dynamically hot galaxies. I - Structural properties  

NASA Technical Reports Server (NTRS)

Results are reported from an analysis of the structural properties of dynamically hot galaxies which combines central velocity dispersion, effective surface brightness, and effective radius into a new 3-space (k), in which the axes are parameters that are physically meaningful. Hot galaxies are found to divide into groups in k-space that closely parallel conventional morphological classifications, namely, luminous ellipticals, compacts, bulges, bright dwarfs, and dwarf spheroidals. A major sequence is defined by luminous ellipticals, bulges, and most compacts, which together constitute a smooth continuum in k-space. Several properties vary smoothly with mass along this continuum, including bulge-to-disk ratio, radio properties, rotation, degree of velocity anisotropy, and 'unrelaxed'. A second major sequence is comprised of dwarf ellipticals and dwarf spheroidals. It is suggested that mass loss is a major factor in hot dwarf galaxies, but the dwarf sequence cannot be simply a mass-loss sequence, as it has the wrong direction in k-space.

Bender, Ralf; Burstein, David; Faber, S. M.

1992-01-01

290

MAGNETIC DRAG ON HOT JUPITER ATMOSPHERIC WINDS  

SciTech Connect

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

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

2010-08-20

291

Magnetic Drag on Hot Jupiter Atmospheric Winds  

NASA Astrophysics Data System (ADS)

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

Perna, Rosalba; Menou, Kristen; Rauscher, Emily

2010-08-01

292

Hot European summers: Present and Future  

NASA Astrophysics Data System (ADS)

Hot summers, such as occurred in Europe in 2003, and Russia in 2010 have a devastating societal impact. In 2003, for example, there were over 14,000 heat related deaths in France alone. Predicting how the frequency of such events will change in a changing climate is therefore critically important for planning and adaptation. This study presents a modelling and observational analysis of how the large-scale circulation interacts with terrestrial processes to cause hot summers in Europe. We use an offline land-surface model, in combination with a very high resolution (25 km) global climate model, to investigate how changes in bio-physical processes, land-atmosphere interactions and the large-scale circulation will affect the frequency of hot summers in the future. This study suggests that, not only do changes in climate strongly impact terrestrial ecosystems, but that plant processes have a significant impact on future summer climate in Europe.

Black, E.; Vidale, P.; Verhoef, A.; Schiemann, R.; Demory, M.

2013-12-01

293

Glowing Hot Transiting Exoplanet Discovered  

NASA Astrophysics Data System (ADS)

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

2003-04-01

294

Hot water, fresh beer, and salt  

NASA Astrophysics Data System (ADS)

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

Crawford, Frank S.

1990-11-01

295

Evolution of Hot Gas in Elliptical Galaxies  

NASA Technical Reports Server (NTRS)

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.

Mathews, William G.

2004-01-01

296

The Hot ISM of Normal Galaxies  

NASA Technical Reports Server (NTRS)

X-ray observations of galaxies have shown the presence of hot ISM and gaseous halos. The most spectacular examples am in early-type galaxies (E and S0), and in galaxies hosting intense starforming regions. This talk will review the observational evidence and highlight the outstanding issues in our understanding of this gaseous component, with emphasis on our present understanding of the chemical composition of these hot halos. It will address how Chandra, XMM, and future X-ray missions can address these studies.

Fabbiano, Giuseppina

1999-01-01

297

Validation of the Hot Strip Mill Model  

SciTech Connect

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.

Richard Shulkosky; David Rosberg; Jerrud Chapman

2005-03-30

298

What's Hot in Yellowstone National Park  

NSDL National Science Digital Library

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

299

Controlled-Temperature Hot-Air Gun  

NASA Technical Reports Server (NTRS)

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.

Munoz, M. C.

1986-01-01

300

Origin and pulsation of hot subdwarfs  

NASA Astrophysics Data System (ADS)

We briefly introduce hot subdwarfs and their evolutionary status before discussing the different types of known pulsators in more detail. Currently, at least six apparently distinct types of variable are known among hot subdwarfs, encompassing p- as well as g-mode pulsators and objects in the Galactic field as well as in globular clusters. Most of the oscillations detected can be explained in terms of an iron opacity mechanism, and quantitative asteroseismology has been very successful for some of the pulsators. In addition to helping constrain possible evolutionary scenarios, studies focussing on stellar pulsations have also been used to infer planets and characterize the rotation of the host star.

Randall, S. K.; Fontaine, G.; Charpinet, S.; Van Grootel, V.; Brassard, P.

2014-02-01

301

Quantum effects in the hot electron microbolometer  

SciTech Connect

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.

Tang, A.; Richards, P.L.

1994-10-01

302

Hot Jupiters: Atmospheric Constraints from Repeated Eclipses  

NASA Astrophysics Data System (ADS)

We propose to perform repeated secondary eclipse measurements of the 'hot Jupiter' planet HD 209458b, with IRAC at 8 micron. Tentative evidence for variability in eclipse depth exists for HD 209458b. This program will firmly establish the existence of variability (or constrain it extremely well), will provide some the most accurate brightness temperature measurements to date for any extrasolar planet and will achieve several important secondary goals. The data thus collected will constitute a long-lasting product in the form of constraints for existing and future generations of hot Jupiter atmospheric models.

Menou, Kristen; Cho, James; Deming, Drake; Hansen, Brad; Harrington, Joseph; Rauscher, Emily; Seager, Sara

2008-03-01

303

Ribosomal DNA Replication Fork Barrier and HOT1 Recombination Hot Spot: Shared Sequences but Independent Activities  

PubMed Central

In the ribosomal DNA of Saccharomyces cerevisiae, sequences in the nontranscribed spacer 3? of the 35S ribosomal RNA gene are important to the polar arrest of replication forks at a site called the replication fork barrier (RFB) and also to the cis-acting, mitotic hyperrecombination site called HOT1. We have found that the RFB and HOT1 activity share some but not all of their essential sequences. Many of the mutations that reduce HOT1 recombination also decrease or eliminate fork arrest at one of two closely spaced RFB sites, RFB1 and RFB2. A simple model for the juxtaposition of RFB and HOT1 sequences is that the breakage of strands in replication forks arrested at RFB stimulates recombination. Contrary to this model, we show here that HOT1-stimulated recombination does not require the arrest of forks at the RFB. Therefore, while HOT1 activity is independent of replication fork arrest, HOT1 and RFB require some common sequences, suggesting the existence of a common trans-acting factor(s).

Ward, Teresa R.; Hoang, Margaret L.; Prusty, Reeta; Lau, Corine K.; Keil, Ralph L.; Fangman, Walton L.; Brewer, Bonita J.

2000-01-01

304

Hot Stars in the Galactic Halo  

NASA Astrophysics Data System (ADS)

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.

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

2011-03-01

305

Semiempirical hot atom theory. I - Initialization and application  

NASA Technical Reports Server (NTRS)

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

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

1981-01-01

306

Sedimentation in Hot Creek in vicinity of Hot Creek Fish Hatchery, Mono County, California  

USGS Publications Warehouse

An accumulation of fine-grained sediment in Hot Creek downstream from Hot Creek Fish Hatchery, Mono County, Calif., created concern that the site may be deteriorating as a habitat for trout. The accumulation is a phenomenon that probably occurs naturally in the problem reach. Fluctuation in the weather probably is the basic cause of the deposition of fine-grained sediment that has occurred since about 1970. Man 's activities and the Hot Creek Fish Hatchery may have contributed to the problem; the significance of these factors, however, probably was magnified because of drought conditions in 1975-77. (Woodard-USGS)

Burkham, D. E.

1978-01-01

307

Hot Bang States of Massless Fermions  

Microsoft Academic Search

According to the characterization of local thermal equilibrium states in Local Quantum Physics proposed by Buchholz et al. microscopic and corresponding macroscopic observables are computed for the model of massless, free fermions on Minkowski space. An example for a local equilibrium state describing a hot bang is given, the main step being the proof of its positivity.

Benjamin Bahr

2006-01-01

308

Integrated Approach for Prediction of Hot Tearing  

NASA Astrophysics Data System (ADS)

Shrinkage, imposed strain rate, and (lack of) feeding are considered the main factors that determine cavity formation or the formation of hot tears. A hot-tearing model is proposed that will combine a macroscopic description of the casting process and a microscopic model. The micromodel predicts whether porosity will form or a hot tear will develop. Results for an Al-4.5 pct Cu alloy are presented as a function of the constant strain rate and cooling rate. Also, incorporation of the model in a finite element method (FEM) simulation of the direct-chill (DC) casting process is reported. The model shows features well known from literature such as increasing hot-tearing sensitivity with increasing deformation rate, cooling rate, and grain size. Similar trends are found for the porosity formation as well. The model also predicts a beneficial effect of applying a ramping procedure during the start-up phase, which is an improvement in comparison with earlier findings obtained with alternative models. In principle, the model does not contain adjustable parameters, but several parameters are not well known. A full quantitative validation not only requires detailed casting trials but also independent determination of some thermophysical parameters of the semisolid mush.

Suyitno; Kool, W. H.; Katgerman, L.

2009-10-01

309

Highly charged ions in hot, dense plasmas.  

National Technical Information Service (NTIS)

Highly-charged ions play a critical role in hot, dense plasmas. They affect the energy balance and hydrodynamic evolution of transient plasmas. The radiation emitted by highly charged ions may be used in several practical applications, such as inertial co...

A. L. Osterheld R. S. Walling B. K. F. Young W. H. Goldstein G. Shimkaveg

1992-01-01

310

Plasmas are Hot and Fusion is Cool  

ScienceCinema

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.

311

Hot Hollow Cathode Control System Upgrade Proposal.  

National Technical Information Service (NTIS)

The hot hollow cathode (HHC) coating process is used to produce highly adherent coatings for solid state bonding. It is a very complex multi-step coating process requiring constant operator attention and input for periods up to one hour. To insure that go...

J. A. Arluck J. L. Walling

1980-01-01

312

Hot-Gas Filter Ash Characterization Project.  

National Technical Information Service (NTIS)

Large-scale hot-gas filter testing over the past 10 years has revealed numerous cases of cake buildup on filter elements that has been difficult, if not impossible, to remove. At times, the cake can blind or bridge between candle filters, leading to filte...

M. L. Swanson J. P. Hurley B. A. Dockter C. A. O'Keefe

1997-01-01

313

Hot-Gas Filter Ash Characterization Project.  

National Technical Information Service (NTIS)

Large-scale hot-gas testing over the past several years has revealed numerous cases of cake buildup on filter elements that have been difficult, if not impossible to remove. At times, the cake can bridge between candle filters, leading to high filter fail...

B. A. Dockter J. P. Hurley T. A. Watne K. A. Katrinak C. A. O'Keefe

1996-01-01

314

Advanced hot-gas filter development.  

National Technical Information Service (NTIS)

Coal is the most abundant fossil-fuel resource in the United States. 'Clean coal' technologies, such as pressurized fluidized-bed combustion (PFBC) and integrated gasification combined-cycle (IGCC), require a hot gas filter to remove the corrosive and ero...

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

1997-01-01

315

Hot-Melt Extrusion Technique: A Review  

Microsoft Academic Search

Hot-melt extrusion is one of the most widely applied processing technologies in the plastic, rubber and food industry. Today this technology has found its place in the array of pharmaceutical manufacturing operations. Melt extrusion process are currently applied in the pharmaceutical field for the manufacture of a variety of dosage forms and formulations such as granules, pellets, tablets, suppositories, implants,

Rina Chokshi; Hossein Zia

316

Hot-carrier currents of SOI MOSFETs  

Microsoft Academic Search

MOSFETs built on the SOI structure exhibit superior short channel behaviors over the bulk MOSFETs. They also have other advantages such as reduction of the junction capacitance, radiation hardness and ease for device isolation. The SOI MOSFET is a promising candidate for future device scaling. The hot-carrier effect that increases with device miniaturization is another important device scaling constraint that

Hsing-Jen Wann; J. King; Jian Chen; P. K. Ko; Chenming Hu

1993-01-01

317

Fastener Tightening in a Radioactive (Hot) Cell.  

National Technical Information Service (NTIS)

Accurate remote tightening of fasteners in a radioactive (Hot) cell can be a very exasperating experience. Viewing can be difficult (in many places) and work sometimes must be done using mirrors and/or cameras. If electro mechanical manipulators are used,...

J. J. Kalk

1986-01-01

318

Hot cell facility at Kernforschungszentrum Karlsruhe  

Microsoft Academic Search

The hot cell facility for material testing of the Kernforschungszentrum Karlsruhe (KfK) was put into operation in three phases of construction: (1) in 1966, section 1 was completed as the heart of the facility: 5 concrete cells with 11 work stations and 4 lead-shielded cells for metallographic examinations, material testing, and decontamination of irradiated specimens. (2) In 1976, section 2

Enderlein

1987-01-01

319

Quantum effects in the hot electron microbolometer.  

National Technical Information Service (NTIS)

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...

A. Tang P. L. Richards

1994-01-01

320

Hot crenarchaeal viruses reveal deep evolutionary connections  

Microsoft Academic Search

The discovery of archaeal viruses provides insights into the fundamental biochemistry and evolution of the Archaea. Recent studies have identified a wide diversity of archaeal viruses within the hot springs of Yellowstone National Park and other high-temperature environments worldwide. These viruses are often morphologically unique and code for genes with little similarity to other known genes in the biosphere, a

Alice C. Ortmann; Blake Wiedenheft; Trevor Douglas; Mark Young

2006-01-01

321

Nontuberculous mycobacterial disease following hot tub exposure.  

PubMed Central

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

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

322

Canopy Hot-Spot as Crop Identifier.  

National Technical Information Service (NTIS)

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...

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

1986-01-01

323

[Whirlpool-Dermatitis with "hot hands"].  

PubMed

History and admission findings: A 15-year-old boy presented with painful nodules on his palms and discrete pustules on the forearm. Two days earlier he had taken a bath in a new whirlpool. Investigations: Bacteriological examination of the pustules revealed Pseudomonas aeruginosa. The cervical and axillary lymph nodes were inconspicuous. Treatment and course: The dermal infection with Pseudomonas aeruginosa was treated with i.v. piperacillin 4 g/tazobactam 0,5 g twice daily. Furthermore, the patient received 400 mg ibuprofen twice daily per os. Seven days later all symptoms had resolved. Conclusion: Hot tubs are a potential source of cutaneous infections with the gram-negative rod Pseudomonas aeruginosa. The most common clinical manifestation of these infections is "hot tub- or jacuzzi-folliculitis" with pustules mainly on the trunk and lymphadenopathy. In children and adolescents, the clinical picture may differ, with a predominance of tender reddish nodules on the palms or soles named "hot hand/hot foot syndrome". In general, the first-line antibiotic in an infection with pseudomonas aeruginosa is ciprofloxacin but it is not recommended in children and adolescents. PMID:24983193

Dietrich, K-A; Ruzicka, T; Herzinger, T

2014-07-01

324

Mutation hot spots in mammalian mitochondrial DNA  

PubMed Central

Animal mitochondrial DNA is characterized by a remarkably high level of within-species homoplasy, that is, phylogenetic incongruence between sites of the molecule. Several investigators have invoked recombination to explain it, challenging the dogma of maternal, clonal mitochondrial inheritance in animals. Alternatively, a high level of homoplasy could be explained by the existence of mutation hot spots. By using an exhaustive mammalian data set, we test the hot spot hypothesis by comparing patterns of site-specific polymorphism and divergence in several groups of closely related species, including hominids. We detect significant co-occurrence of synonymous polymorphisms among closely related species in various mammalian groups, and a correlation between the site-specific levels of variability within humans (on one hand) and between Hominoidea species (on the other hand), indicating that mutation hot spots actually exist in mammalian mitochondrial coding regions. The whole data, however, cannot be explained by a simple mutation hot spots model. Rather, we show that the site-specific mutation rate quickly varies in time, so that the same sites are not hypermutable in distinct lineages. This study provides a plausible mutation model that potentially accounts for the peculiar distribution of mitochondrial sequence variation in mammals without the need for invoking recombination. It also gives hints about the proximal causes of mitochondrial site-specific hypermutability in humans.

Galtier, Nicolas; Enard, David; Radondy, Yoan; Bazin, Eric; Belkhir, Khalid

2006-01-01

325

Hot Forming With Electron-Beam Welder  

NASA Technical Reports Server (NTRS)

Hot forming to restore size and shape of thin metal parts done with electron-beam welder. Work-piece heated in scanning defocused electron beam rather than conventional heat-treating furnace. Technique proved successful in straightening some thin flanges of nickel alloy and titanium.

Dobson, R. K.; Whiffen, E. L.

1984-01-01

326

Bog Hot Springs, Nevada: the geothermal cycle  

Microsoft Academic Search

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

1977-01-01

327

Geothermal: hot energy for the future  

Microsoft Academic Search

Using hot groundwater for indoor space heating and water heating has now emerged as a possibility that may alter New Mexico's energy future dramatically. The commitment to geothermal development at the state level has attracted national attention and funding. The New Mexico Energy Institute at New Mexico State University (NMEI-NMSU) in Las Cruces, where geothmal resources have been located, is

Thompson

1980-01-01

328

Hot Air Coagulation: An Animal Study  

Microsoft Academic Search

Aerothermotherapy with a Leister® hot air coagulator was tested in a simulated operation field followed by a prospective double-blind animal pilot study to examine hemostasis and tissue reactions. Two symmetrical incisions were made on the back of 5 rabbits. One of the two wounds was randomised to aerothermotherapy. The temperature rise in the wound was registered by thermistors. No wound

C. Rude; O. V. Rasmussen; C. Rygaard; F. Haslev

1988-01-01

329

All Secondary Explosive Hot-Wire Devices.  

National Technical Information Service (NTIS)

The explosives PETN, HMX, HNS-1 and RDX can be ignited by a hot wire at low-current levels. When deflagrated under confinement, PETN and HMX generate sufficient gas pressures to actuate a valve or cutting mechanism. Under proper conditions, deflagrations ...

D. T. Varley R. H. Dinegar

1979-01-01

330

Hot Dry Rock at Fenton Hill, USA.  

National Technical Information Service (NTIS)

The Hot Dry Rock Geothermal Energy Project began in the early 1970's with the objective of developing a technology to make economically available the large ubiquitous thermal energy of the upper earth crust. The program, operated by the Los Alamos Nationa...

R. H. Hendron

1988-01-01

331

Hot spot and trench volcano separations  

Microsoft Academic Search

WE suggest that the distribution of separations between trench volcanoes located along subduction zones reflects the depth of partial melting, and that the separation distribution for hot spot volcanoes near spreading centres provides a measure of the depth of mantle convection cells.

R. E. Lingenfelter; G. Schubert

1974-01-01

332

Redshift of photons penetrating a hot plasma  

Microsoft Academic Search

A new interaction, plasma redshift, is derived, which is important only when photons penetrate a hot, sparse electron plasma. The derivation of plasma redshift is based entirely on conventional axioms of physics. When photons penetrate a cold and dense plasma, they lose energy through ionization and excitation, Compton scattering on the individual electrons, and Raman scattering on the plasma frequency.

Ari Brynjolfsson

2004-01-01

333

Overall Kinetics of Hot Gas Ignition  

Microsoft Academic Search

Overall rate expressions have been developed to describe the ignition of nearly stagnant fuel-air mixtures in a vertical jet of hot, inert gas. Kinetic parameters, frequency factor A, activation energy E, fuel power C and oxygen power D, were computed to match experimental ignition results in the rate expressionwhere(C + D) = total order of reactionMf = molecular weight of

ZACHARY J. FINK; MARCEL VANPEE

1975-01-01

334

Transfer of hot dry rock technology  

SciTech Connect

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

Smith, M.C.

1985-11-01

335

Joining Refractory Metal Compounds by Hot Pressing.  

National Technical Information Service (NTIS)

A study was made to determine the feasibility of joining refractory metal compounds to each other and to oxide ceramics by a vacuum hot press-diffusion bonding method. Very satisfactory joins were made of ZrC to ZrB2, ZrN to ZrB2, ZrC to ZrN, and of ZrC, ...

J. E. Kelley D. H. Sumner H. J. Kelly

1969-01-01

336

Statistical fragmentation of hot atomic metal clusters  

Microsoft Academic Search

Fragmentation processes of highly excited neutral and charged atomic metal clusters are studied in the framework of an equilibrium statistical model. In the particular case of hot (near and above melting) neutral and charged sodium clusters of 100 and 200 atoms, a microcanonical Metropolis sampling is used to compute mass (or charge) correlation functions as a function of the excitation

D. H. E. Gross; P. A. Hervieux

1995-01-01

337

Transient surface heating in hot, burning flows  

Microsoft Academic Search

Work currently being performed to investigate the fundamental mechanisms of wear and erosion in gun barrels and other systems involving hot propellant flows is described. In particular, analysis is presented of timewise changes in the surface-temperature distribution in response to transient heat fluxes at the wall. Results show sizable increases in the wall temperatures so that melting and erosion of

S. W. Kang; J. L. Levatin

1981-01-01

338

Spectropolarimetric modelling of hot star wind structure  

Microsoft Academic Search

A short overview is given of some recent progress in the theory of spectropolarimetry as a diagnostic of axisymmetric hot star wind density and velocity structure, covering the inferences possible from broad band polarimetry, from polarimetric light curves and simultaneous absorption line data, and from spectropolarimetric line profiles. Recent work on joint spectro-, photo-, and polari-metric study of the properties

John C. Brown

1994-01-01

339

Teaching Earth Science Using Hot Air Balloons  

ERIC Educational Resources Information Center

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

Kuhl, James; Shaffer, Karen

2008-01-01

340

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...

341

Fly a Hot-Air Balloon  

NSDL National Science Digital Library

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

Museum Of Science And Industry, Chicago

2012-01-01

342

Super Hot Hydrogen Atoms in Microwave Plasmas  

NASA Astrophysics Data System (ADS)

``Super hot'' (with kinetic energy in the range 4 - 8 eV) and ``hot'' (kinetic energy ˜ 0.3 eV) hydrogen atoms were detected throughout the volume of a surface wave (500 MHz) generated H2 plasma column, at pressure p = 0.01 mbar, from the analysis of the H?, H?, H?and H? emission line profiles. The profiles were found to evolve from single Gaussian to bi-Gaussian towards the column end. Population inversion between the levels 5->4 and 6->4 was detected from the measured relative intensities of transitions within the Balmer series. The Doppler temperatures corresponding to the H?, H?, H?, H? line broadening are much higher than the rotational temperature, as measured from the hydrogen molecular Fulcher-? band (350 -- 500 K), and than the wall temperature (300 -- 450 K). At pressure p = 0.2 mbar, ``super hot'' atoms were not detected while ``hot'' atoms are present. It has also been found that the kinetic temperature of excited H (n = 4 -7) atoms, as determined from the fitting of the spectral lines with a single Gaussian profile, increases with the upper level principal quantum number. These experimental results are analyzed in the framework of a kinetic model, which accounts for the generation of three groups of atoms.

Felizardo, Edgar; Tatarova, Elena; Dias, Francisco; Lino da Silva, M.; Ferreira, Carlos; Gordiets, Boris

2009-10-01

343

When hot water freezes before cold  

Microsoft Academic Search

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

J. I. Katz

2006-01-01

344

Solar-powered hot-air system  

NASA Technical Reports Server (NTRS)

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.

1979-01-01

345

Asphalt Hot-Mix Emission Study.  

National Technical Information Service (NTIS)

The findings of this study may be summarized by the statement that there is no serious air pollution or employee health problem resulting from the use of petroleum-derived asphalt in hot-mixes. The findings are based on eight complete sets of emission sam...

1975-01-01

346

Hot strength properties of filamentary nickel alloys  

Microsoft Academic Search

The results of an investigation of the hot strength properties of several nickel- and cobalt-based alloys are given. These materials, having as minor constituents such elements as aluminum, tungsten, chromium, etc., were chosen for their possibilities as efficient primary electron emitters (when coated with alkaline earth oxides). The diameters of these filaments were all 0.001 inch or less. The general

B. Wolk

1958-01-01

347

The Inner Source of Hot Preplanetary Matter  

NASA Astrophysics Data System (ADS)

The inner source of hot preplanetary matter D. Möhlmann DLR, Institut für Raumsim- ulation, 51170 Köln, Germany email:dirk.moehlmann@dlr.de Viscous interactions in quasi-stationary protoplanetary disks are the cause of outward transport of matter and angular momentum and of the growth of the mass of the central body, as described quantitatively first by Lynden-Bell &Pringle, 1974. These processes are discussed in detail with respect to the properties of the planetary system, especial ly the angular momentum. The main result is that in the early phases there is also in the disk-regions of the present planetary system a temporary outflow of matter away from the yet grow- ing central body. This causes a transport of hot matter into the early disk into regions of the present planetary system. Thgis hot matter is one of the two compo nents of disk matter. The other component falls in from the collapsing cool envelope. The flow direction of the "inner component" reverses in time. Resulting implications, which are discussed more in detail, are the description of this inner source of hot matter of the early preplanetary disk, the evolution and distribution of related parameters of this disk, as densities, time-scale and temperatures, and the mass distribution in the planetary region and in the distant disk.

Moehlmann, D.

348

The hot corona of YY Mensae  

NASA Technical Reports Server (NTRS)

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.

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

1996-01-01

349

Neutrino physics in hot and dense media  

SciTech Connect

Neutrino dispersion in hot and dense media is calculated for ranges of temperature and chemical potential [ital T], [mu][much lt][ital T][sub QCD] (200 MeV) for energies [ital q][sup 2][much lt][ital m][sub [ital Z

Masood, S.S. (Department of Physics, Quaid-i-Azam University, Islamabad (Pakistan))

1993-10-01

350

Relativistic particle transport in hot accretion disks  

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

351

Hot Jupiter Variability in Eclipse Depth  

Microsoft Academic Search

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

Emily Rauscher; Kristen Menou; James Y.-K. Cho; Sara Seager; Bradley M. S. Hansen

2007-01-01

352

Sulphur Chemistry and Evolution in Hot Cores  

Microsoft Academic Search

We compare the results of our JCMT spectralline survey of molecular gas towards ultracompact Hii regionswith the predictions of models of sulphur chemistryin hot cores. We investigate the range of evolutionary modelsthat are consistent with the observed physical conditionsand chemical abundances, and see to what extentit is possible to constrain core ages by comparing abundanceswith the predictions of chemical models.

G. H. Macdonald; J. Hatchell; M. A. Thompson; T. J. Millar

353

Storage capacity in hot dry rock reservoirs  

DOEpatents

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

Brown, Donald W. (Los Alamos, NM)

1997-01-01

354

Airborne Emissions Assessment of Hot Asphalt Mixing  

Microsoft Academic Search

Hot mix asphalt industries are required to meet airborne emissions thresholds, yet only a few types of emission measurements are available. This study is therefore aimed at evaluating the influence of operating parameters on airborne emissions at the plant stack, especially Gaseous Organic Compounds (GOC), in addition to identifying both the best mixing conditions and bitumen influence through laboratory testing.

Agnès Jullien; Vincent Gaudefroy; Anne Ventura; Chantal de la Roche; Régis Paranhos; Pierre Monéron

2010-01-01

355

hot-mix asphalt paving batch plant  

Microsoft Academic Search

Hot-mix asphalt paving plant operations and the associated air pollution control problems are presented. Field observations and test data are included for full scale installations. Comparisons are made for various types of control equipment and their effectiveness. The dry cyclonic units offer the least cost expenditures, lowest space requirements, and can collect the fines in a usable condition. Wear can

H. E. Friedrich

1969-01-01

356

Stiffness of Hot-Mix Asphalt  

Microsoft Academic Search

This research was initiated from a need to evaluate marginal mixtures that do not meet the Superpave mix design criteria for the air voids content requirements for the construction of hot mix asphalt pavements. The developed criteria is comprised of the base criteria derived from test data of as-placed field cores normalized to 7.5% air voids content, which provides the

Terhi Kristiina Pellinen; Shangzhi Xiao

2006-01-01

357

Solar-powered hot-water system  

NASA Technical Reports Server (NTRS)

Hot-water system requires no external power except solar energy. System is completely self-controlling. It includes solar-powered pump, solar-thermally and hydrothermally operated valves, and storage tank filled with open-celled foam, to maintain thermal stratification in stored water.

Collins, E. R.

1979-01-01

358

Modelling recrystallization after hot deformation of aluminium  

Microsoft Academic Search

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

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

1996-01-01

359

Probe measures characteristics of hot gas stream  

NASA Technical Reports Server (NTRS)

Shielded, tubular flow calorimeter operated by valve position measures characteristics of a hot gas stream of unknown composition. Measurements of mass flow density and total heat content per unit mass, total heat content per unit mass only, and pitot pressure are made.

1965-01-01

360

Developments in multicavity hot runner tooling.  

PubMed

Technological developments in specific areas of multicavity hot runner systems are improving quality control and repeatability and reducing cycle times. Advances such as closed loop filling control of multicavity moulds within the mould itself, servo-actuated valve gates and synchronised valve stems are discussed. PMID:19626955

Glendenning, P

2009-01-01

361

Hot topics in flavor physics at CDF  

SciTech Connect

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.

Jun, Soon Yung; /Carnegie Mellon U.

2005-01-01

362

Plasmas are Hot and Fusion is Cool  

SciTech Connect

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

None

2011-01-01

363

Hot cracking during welding and casting  

NASA Astrophysics Data System (ADS)

Aluminum welds are susceptible to liquation cracking in the partially melted zone (PMZ). Using the multicomponent Scheil model, curves of temperature vs. fraction solid (T-fS) during solidification were calculated for the PMZ and weld metals (WMs). These curves were used to predict the crack susceptibility by checking if the harmful condition of WM fS > PMZ fS exists during PMZ solidification and reduce the susceptibility by minimizing this condition. This approach was tested against full-penetration welds of alloys 7075 and 2024 and it can be used to guide the selection or development of filler metals. Liquation cracking in the PMZ in welds of Al-Si cast alloys was also investigated. The crack susceptibility was evaluated by circular-patch test, and full-penetration welds made with filler metals 1100, 4043, 4047 and 5356. Liquation cracking was significant with filler metals 1100 and 5356 but slight with filler metals 4043 and 4047. In all welds, liquation cracks were completely backfilled, instead of open as in full-penetration welds of wrought alloys 2219 and 6061. The T-fS curves showed that alloy A357 has a much higher fraction liquid for backfilling before PMZ solidification was essentially over. Hot tearing in Mg-xAl-yCa alloys was studied by constrained rod casting (CRC) in a steel mold. The hot tearing susceptibility decreased significantly with increasing Ca content (y) but did not change much with the Al content (x). An instrumented CRC with a steel mold was developed to detect the onset of hot tearing. The secondary phases, eutectic content, solidification path, and freezing range were examined. Hot tearing in Mg-Al-Sr alloys was also studied by CRC in a steel mold. With Mg-(4,6,8)Al-1.5Sr alloys, the hot tearing susceptibility decreased significantly with increasing Al content. With Mg-(4,6,8)Al-3Sr alloys, the trend was similar but not as significant. At the same Al content, the hot tearing susceptibility decreased significantly with increasing Sr content. Instrumented CRC with a steel mold was also used to test hot tearing of Mg-Al-Sr alloys. Cracking occurred at a higher temperature in alloys most susceptible to cracking than in alloys least susceptible.

Cao, Guoping

364

A search for binary hot subdwarfs  

NASA Astrophysics Data System (ADS)

The hot subdwarfs are evolved stars intermediate between the hydrogen burning main sequence and the white dwarfs. As the immediate precursors of white dwarfs they are essential to a complete understanding of the end points of stellar evolution, and as exemplars of extreme mass- loss stars they may be windows on one of astronomy's least understood problems. But the origins of the hot subdwarfs are obscure. Duplicity may play a role in the enhanced mass-loss hot subdwarfs must suffer, and it is known that the hydrogen-rich sdB hot subdwarfs show a high binary fraction. The helium-rich hot subdwarfs, the putative descendants of the sdB stars, are only weakly characterized with respect to binarity. The helium-rich hot subdwarfs are the subject of this research, and the question of their duplicity is its focus. Sixty-four helium-rich hot subdwarfs drawn from the Palomar-Green Survey of UV-Excess Stellar Objects were observed on the Cousins BV RI photometric system. A subset of twenty-five of the 64 program stars were observed in the IR J and K pass-bands. Spectroscopic data were obtained for thirty-two members of the sample, including seven that have not been observed in either the BV RI or the JK filter sets. A total of sixteen binary candidates were identified, twelve for the first time. Binary candidates were identified by their intrinsic color excesses in two-color plots of the extinction-corrected BV RI and JK data, and by comparison to synthetic binary system colors. Spectrophotometric color indices were derived from the spectroscopic data and used to identify binary candidates by their excess color in two color plots. The binary fraction of the sdOC stars in the sample is predicted to be at least 64% and potentially 100%. A binary fraction for the whole sample of sdOs may have limited meaning, given the probable inhomogeneity of the sample. However, performing the calculation for the whole sample again produces the estimate that at least 64% and at most 100% of the sample is binary.

Williams, William Thomas

2001-12-01

365

Kelly Hot Spring Geothermal Project: Kelly Hot Spring Agricultural Center Preliminary Design. Final Technical Report.  

National Technical Information Service (NTIS)

A Phase 1 Preliminary Design, Construction Planning and Economic Analysis has been conducted for the Kelly Hot Spring Agricultural Center in Modoc County, California. The core activity is a 1360 breeding sow, swine raising complex that utilizes direct hea...

A. B. Longyear

1980-01-01

366

Kelley Hot Spring Geothermal Project: Kelly Hot Spring Agricultural Center Conceptual Design.  

National Technical Information Service (NTIS)

The proposed core activity in the Kelly Hot Spring Agricultural Center is a nominal 1200 sow swine raising complex. The swine raising is to be a totally confined operation for producing premium pork in controlled environment facilities that utilize geothe...

A. B. Longyear

1980-01-01

367

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

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

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

368

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

369

21 CFR 890.5710 - Hot or cold disposable pack.  

Code of Federal Regulations, 2012 CFR

...Identification. A hot or cold disposable pack is a device intended for medical purposes that consists of a sealed plastic bag incorporating chemicals that, upon activation, provides hot or cold therapy for body surfaces. (b)...

2012-04-01

370

21 CFR 890.5710 - Hot or cold disposable pack.  

...Identification. A hot or cold disposable pack is a device intended for medical purposes that consists of a sealed plastic bag incorporating chemicals that, upon activation, provides hot or cold therapy for body surfaces. (b)...

2014-04-01

371

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

372

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

373

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

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

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

374

21 CFR 890.5710 - Hot or cold disposable pack.  

Code of Federal Regulations, 2010 CFR

...Identification. A hot or cold disposable pack is a device intended for medical purposes that consists of a sealed plastic bag incorporating chemicals that, upon activation, provides hot or cold therapy for body surfaces. (b)...

2010-04-01

375

21 CFR 890.5710 - Hot or cold disposable pack.  

Code of Federal Regulations, 2011 CFR

...Identification. A hot or cold disposable pack is a device intended for medical purposes that consists of a sealed plastic bag incorporating chemicals that, upon activation, provides hot or cold therapy for body surfaces. (b)...

2011-04-01

376

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

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

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

377

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

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

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

378

'Nerve Block' to Neck Might Help Ease Hot Flashes  

MedlinePLUS

... JavaScript. 'Nerve Block' to Neck Might Help Ease Hot Flashes Women in small study suffered fewer moderate- ... Feb. 17, 2014 (HealthDay News) -- Women suffering from hot flashes might get some relief through an injection ...

379

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

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

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

380

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

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

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

381

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

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

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

382

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

383

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

384

Installation Package for a Solar Heating and Hot Water System.  

National Technical Information Service (NTIS)

Two commercial solar heating and hot water systems have been developed. The systems have been installed at Yosemite National Park, California and Pueblo, Colorado. The systems consist of the following subsystems: collector, storage, transport, hot water, ...

1978-01-01

385

Oxidation and hot corrosion of hot-pressed Si3N4 at 1000 deg C  

NASA Technical Reports Server (NTRS)

The oxidation and hot corrosion of a commercial, hot-pressed Si3N4 were investigated at 1000 C under an atmosphere of flowing O2. For the hot corrosion studies, thin films of Na2SO4 were airbrushed on the Si3N4 surface. The hot corrosion attack was monitored by the following techniques: continuous weight measurements, SO2 evolution, film morphology, and chemical analyses. Even though the hot corrosion weight changes after 25 hr were relatively small, the formation of SiO2 from oxidation of Si3N4 was an order of magnitude greater in the presence of molten Na2SO4. The formation of a protective SiO2 phase at the Si3N4 surface is minimized by the fluxing action of the molten Na2SO4 thereby allowing the oxidation of the Si3N4 to proceed more rapidly. A simple process is proposed to account for the hot corrosion process.

Fielder, W. L.

1985-01-01

386

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

NASA Technical Reports Server (NTRS)

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

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

2013-01-01

387

Advances in Hot-Structure Development  

NASA Technical Reports Server (NTRS)

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

Rivers, H. Kevin; Glass, David E.

2006-01-01

388

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

389

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

ERIC Educational Resources Information Center

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

National Institute for Literacy, 2001

2001-01-01

390

Incidence and Management of Hot Flashes in Prostate Cancer  

Microsoft Academic Search

Hot flashes are as common in men who have been castrated due to prostate cancer as hot flashes are in women after menopause. The symptom can cause significant discomfort for a considerable length of time. The hot flashes are most likely caused by a reduction in sex- hormone levels, which, in turn, causes an instability in the hypothalamic thermoregulatory center.

Anna-Clara Spetz; Eva-Lena Zetterlund; Eberhard Varenhorst; Mats Hammar

391

Installation package for a solar heating and hot water system  

NASA Technical Reports Server (NTRS)

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

1978-01-01

392

Trade-offs in cycle time management: hot lots  

Microsoft Academic Search

In manufacturing, higher priority is given to hot lots to reduce their cycle time. The impact of hot lots on the cycle time of other lots in the system is studied here. Object-oriented simulation experiments of a wafer fabrication model were run to investigate the above impact. The simulation results showed that as the proportion of hot lots in the

Babak Ehteshami; R. G. Petrakian; Phyllis M. Shabe

1992-01-01

393

Discovery of feature-based hot spots using supervised clustering  

NASA Astrophysics Data System (ADS)

Feature-based hot spots are localized regions where the attributes of objects attain high values. There is considerable interest in automatic identification of feature-based hot spots. This paper approaches the problem of finding feature-based hot spots from a data mining perspective, and describes a method that relies on supervised clustering to produce a list of hot spot regions. Supervised clustering uses a fitness function rewarding isolation of the hot spots to optimally subdivide the dataset. The clusters in the optimal division are ranked using the interestingness of clusters that encapsulate their utility for being hot spots. Hot spots are associated with the top ranked clusters. The effectiveness of supervised clustering as a hot spot identification method is evaluated for four conceptually different clustering algorithms using a dataset describing the spatial distribution of ground ice on Mars. Clustering solutions are visualized by specially developed raster approximations. Further assessment of the ability of different algorithms to yield hot spots is performed using raster approximations. Density-based clustering algorithm is found to be the most effective for hot spot identification. The results of the hot spot discovery by supervised clustering are comparable to those obtained using the G* statistic, but the new method offers a high degree of automation, making it an ideal tool for mining large datasets for the existence of potential hot spots.

Ding, Wei; Stepinski, Tomasz F.; Parmar, Rachana; Jiang, Dan; Eick, Christoph F.

2009-07-01

394

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

Code of Federal Regulations, 2013 CFR

... 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...

2013-01-01

395

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

Code of Federal Regulations, 2011 CFR

... 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...

2011-01-01

396

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

Code of Federal Regulations, 2012 CFR

... 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...

2012-01-01

397

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

Code of Federal Regulations, 2011 CFR

... 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...

2014-01-01

398

Hot Torsion Simulation of the Holmestrand Hot Rolling Line and Back Annealing Properties of 3003 Foil Stock.  

National Technical Information Service (NTIS)

Results of the present investigation indicate that hot torsion can be applied in simulating an industrial hot rolling line. On the effect of different heat treatments, the results may be summarized as follows: Soaking (high temperature annealing) seems to...

R. Orsund

1989-01-01

399

Study on the quantification of pathogenic factors of wind-hot and hot-wetness cold by extenics multidimentional correlation  

Microsoft Academic Search

Background: To discover the relationship between different etiological factors of wind-hot cold and hot-wetness cold. Methods:We collected clinical data of patients in 5 provinces in china from 2010 to 2011 with wind-hot cold and hot-wetness cold at test plot. We design a questionnaire to find the possible EPFs that patients confronted, including environmental factors, meteorology factors, individual physiology, psychology, and

Guo-qiang Qian; Guo-ping Zhao; Bin He; Xiao-yin Chen

2012-01-01

400

Radiation from hot, bare, strange stars  

NASA Astrophysics Data System (ADS)

We present the results of numerical simulations of stationary, spherically outflowing, e+/- pair winds, with total luminosities of L= 1035-1042 erg s-1. These results have direct relevance to the emission from hot, bare, strange stars, which are thought to be powerful sources of pairs created by the Coulomb barrier at the quark surface. The spectra of emergent photons and pairs are calculated. For L > 2 × 1035 erg s-1, photons dominate the emerging emission. As L increases from ~1035 to 1042 erg s-1, the mean photon energy decreases from ~400-500 keV to 40 keV, whereas the spectrum changes in shape from a wide annihilation line to being nearly blackbody with a high energy (>100 keV) tail. Such a correlation of the photon spectrum with the luminosity, together with the fact that super-Eddington luminosities can be achieved, might be a good observational signature of hot, bare, strange stars.

Aksenov, A. G.; Milgrom, M.; Usov, V. V.

2003-08-01

401

Enabling Technologies for Ceramic Hot Section Components  

SciTech Connect

Silicon-based ceramics are attractive materials for use in gas turbine engine hot sections due to their high temperature mechanical and physical properties as well as lower density than metals. The advantages of utilizing ceramic hot section components include weight reduction, and improved efficiency as well as enhanced power output and lower emissions as a result of reducing or eliminating cooling. Potential gas turbine ceramic components for industrial, commercial and/or military high temperature turbine applications include combustor liners, vanes, rotors, and shrouds. These components require materials that can withstand high temperatures and pressures for long duration under steam-rich environments. For Navy applications, ceramic hot section components have the potential to increase the operation range. The amount of weight reduced by utilizing a lighter gas turbine can be used to increase fuel storage capacity while a more efficient gas turbine consumes less fuel. Both improvements enable a longer operation range for Navy ships and aircraft. Ceramic hot section components will also be beneficial to the Navy's Growth Joint Strike Fighter (JSF) and VAATE (Versatile Affordable Advanced Turbine Engines) initiatives in terms of reduced weight, cooling air savings, and capability/cost index (CCI). For DOE applications, ceramic hot section components provide an avenue to achieve low emissions while improving efficiency. Combustors made of ceramic material can withstand higher wall temperatures and require less cooling air. Ability of the ceramics to withstand high temperatures enables novel combustor designs that have reduced NO{sub x}, smoke and CO levels. In the turbine section, ceramic vanes and blades do not require sophisticated cooling schemes currently used for metal components. The saved cooling air could be used to further improve efficiency and power output. The objectives of this contract were to develop technologies critical for ceramic hot section components for gas turbine engines. Significant technical progress has been made towards maturation of the EBC and CMC technologies for incorporation into gas turbine engine hot-section. Promising EBC candidates for longer life and/or higher temperature applications relative to current state of the art BSAS-based EBCs have been identified. These next generation coating systems have been scaled-up from coupons to components and are currently being field tested in Solar Centaur 50S engine. CMC combustor liners were designed, fabricated and tested in a FT8 sector rig to demonstrate the benefits of a high temperature material system. Pretest predictions made through the use of perfectly stirred reactor models showed a 2-3x benefit in CO emissions for CMC versus metallic liners. The sector-rig test validated the pretest predictions with >2x benefit in CO at the same NOx levels at various load conditions. The CMC liners also survived several trip shut downs thereby validating the CMC design methodology. Significant technical progress has been made towards incorporation of ceramic matrix composites (CMC) and environmental barrier coatings (EBC) technologies into gas turbine engine hot-section. The second phase of the program focused on the demonstration of a reverse flow annular CMC combustor. This has included overcoming the challenges of design and fabrication of CMCs into 'complex' shapes; developing processing to apply EBCs to 'engine hardware'; testing of an advanced combustor enabled by CMCs in a PW206 rig; and the validation of performance benefits against a metal baseline. The rig test validated many of the pretest predictions with a 40-50% reduction in pattern factor compared to the baseline and reductions in NOx levels at maximum power conditions. The next steps are to develop an understanding of the life limiting mechanisms in EBC and CMC materials, developing a design system for EBC coated CMCs and durability testing in an engine environment.

Venkat Vedula; Tania Bhatia

2009-04-30

402

Visual Companions to Transiting Hot Jupiters  

NASA Astrophysics Data System (ADS)

The known short period giant planets constitute a valuable statistical population. From the derived physical and orbital properties of this sample in conjunction with detailed studies of individual objects, we can investigate a wide array of topics, including the internal structures of giant planets, the conditions under which planets form, and their dynamical evolution. The success of such studies relies, of course, on the completeness and accuracy of the underlying data, but many of the known hot Jupiters have not been subjected to high resolution imaging in search of close stellar companions. The presence of a second star (whether physically bound or a chance alignment), can affect the derived stellar and planetary parameters. Moreover, the presence of bound companions can inform us about planetary formation and migration in binary systems. Here we present preliminary results from our adaptive optics survey of 94 transiting hot Jupiter host stars and discuss their significance in the context outlined above.

Quinn, Samuel Noah; Buchhave, Lars A.; White, Russel J.; Raghavan, Deepak

2014-06-01

403

Hot water, fresh beer, and salt  

SciTech Connect

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.

Crawford, F.S. (Lawrence Berkeley Laboratory, Berkeley, CA (USA) Physics Department, University of California, Berkeley, CA (USA))

1990-11-01

404

Hierarchical Simulation of Hot Composite Structures  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

405

An Optimization Study of Hot Stamping Operation  

NASA Astrophysics Data System (ADS)

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

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

2010-06-01

406

Hot cheese: a processed Swiss cheese model.  

PubMed

James Reason's classic Swiss cheese model is a vivid and memorable way to visualise how patient harm happens only when all system defences fail. Although Reason's model has been criticised for its simplicity and static portrait of complex systems, its use has been growing, largely because of the direct clarity of its simple and memorable metaphor. A more general, more flexible and equally memorable model of accident causation in complex systems is needed. We present the hot cheese model, which is more realistic, particularly in portraying defence layers as dynamic and active - more defences may cause more hazards. The hot cheese model, being more flexible, encourages deeper discussion of incidents than the simpler Swiss cheese model permits. PMID:24999771

Li, Y; Thimbleby, H

2014-06-01

407

Turbine Engine Hot Section Technology 1986  

NASA Technical Reports Server (NTRS)

The Turbine Engine Hot Section Technology (HOST) Project of the NASA Lewis Research Center sponsored a workshop to discuss current research pertinent to turbine engine durability problems. Presentations were made concerning the hot section environment and the behavior of combustion liners, turbine blades, and turbine vanes. The presentations were divided into six sessions: Instrumentation, Combustion, Turbine Heat Transfer, Structural Analysis, Fatigue and Fracture, and Surface Protection. Topics discussed included modeling of thermal and fluid-flow phenomena, structural analysis, fatigue and fracture, surface protective coatings, constitutive behavior of materials, stress-strain response, and life-prediction methods. Researchers from industry, academia, and government presented results of their work sponsored by the HOST project.

1986-01-01

408

Hot Flashes and Carotid Intima Media Thickness among Midlife Women  

PubMed Central

Objective Emerging evidence suggests associations between menopausal hot flashes and cardiovascular risk. Whether hot flashes are associated with intima media thickness (IMT) or IMT changes over time is unknown. We hypothesized that reported hot flashes would be associated with greater IMT cross-sectionally and with greater IMT progression over two years. Methods Participants were 432 women ages 45-58 at baseline participating in SWAN Heart, an ancillary study to the Study of Women's Health Across the Nation. Measures at the SWAN Heart baseline and follow-up visit two years later included a carotid artery ultrasound, reported hot flashes (past two weeks: none, 1-5, ?6 days), and a blood sample for measurement of estradiol. Results Women reporting hot flashes ?6 days in the prior two weeks had significantly higher IMT than women without hot flashes at baseline (mean difference(SE), mm =0.02(0.01), p=0.03) and follow-up (mean difference(SE), mm =0.02(0.01), p=0.04) visits, controlling for demographic factors and cardiovascular risk factors. Reporting hot flashes at both study visits was associated with higher follow-up IMT relative to reporting hot flashes at neither visit (mean difference(SE), mm=0.03(0.01), p=0.03). Associations between hot flashes and IMT largely remained after adjusting for estradiol. An interaction between hot flashes and obesity status was observed (p=0.05) such that relations between hot flashes and IMT were observed principally among overweight/obese women. Hot flashes were not associated with IMT progression. Conclusions These findings provided some indication that women reporting hot flashes ?6 days in the prior two weeks may have higher IMT than women without hot flashes, particularly for women who are overweight or obese. Further work should determine whether hot flashes mark adverse underlying vascular changes.

Thurston, Rebecca C.; Sutton-Tyrrell, Kim; Everson-Rose, Susan A.; Hess, Rachel; Powell, Lynda H.; Matthews, Karen A.

2010-01-01

409

Newly developed Fountain pyrometer for a running hot strip in the cooling banks of a hot strip mill  

Microsoft Academic Search

Temperature control of a hot strip has been important in run-out table of hot strip mill in order to stabilize and improve the material properties of its products. We developed a new temperature measurement method for hot strip cooled by a lot of water in the cooling banks. And we developed control system using the new measurement method and confirmed

T. Honda; S. Nakagawa; C. Uematsu; H. Tachibana; Y. Buei; K. Sakagami

2009-01-01

410

A hot-spot mixer model for phonon-cooled NbN hot electron bolometric mixers  

Microsoft Academic Search

Based on a one dimensional heat transport equation for the electrons in a super-conducting hot electron bolometer (HEB) a model for a hot spot mixer is see up. The hot spot parameters are applied in a small signal oscillator model predicting IV curves and conversion gain. Besides its normal resistance and its IF bandwidth a HEB around its optimal operating

Harald Merkel; Pourya Khosropanah; P. Yagoubov; E. Kollberg

1999-01-01

411

A graphene-based hot electron transistor.  

PubMed

We experimentally demonstrate DC functionality of graphene-based hot electron transistors, which we call graphene base transistors (GBT). The fabrication scheme is potentially compatible with silicon technology and can be carried out at the wafer scale with standard silicon technology. The state of the GBTs can be switched by a potential applied to the transistor base, which is made of graphene. Transfer characteristics of the GBTs show ON/OFF current ratios exceeding 10(4). PMID:23488893

Vaziri, Sam; Lupina, Grzegorz; Henkel, Christoph; Smith, Anderson D; Ostling, Mikael; Dabrowski, Jarek; Lippert, Gunther; Mehr, Wolfgang; Lemme, Max C

2013-04-10

412

Elliptical instability in hot Jupiter systems  

NASA Astrophysics Data System (ADS)

Several studies have already considered the influence of tides on the evolution of systems composed of a star and a close-in companion to tentatively explain different observations such as the spin-up of some stars with hot Jupiters, the radius anomaly of short orbital period planets and the synchronization or quasi-synchronization of the stellar spin in some extreme cases. However, the nature of the mechanism responsible for the tidal dissipation in such systems remains uncertain. In this paper, we claim that the so-called elliptical instability may play a major role in these systems, explaining some systematic features present in the observations. This hydrodynamic instability, arising in rotating flows with elliptical streamlines, is suspected to be present in both planet and star of such systems, which are elliptically deformed by tides. The presence and the influence of the elliptical instability in gaseous bodies, such as stars or hot Jupiters, are most of the time neglected. In this paper, using numerical simulations and theoretical arguments, we consider several features associated to the elliptical instability in hot-Jupiter systems. In particular, the use of ad hoc boundary conditions makes it possible to estimate the amplitude of the elliptical instability in gaseous bodies. We also consider the influence of compressibility on the elliptical instability, and compare the results to the incompressible case. We demonstrate the ability for the elliptical instability to grow in the presence of differential rotation, with a possible synchronized latitude, provided that the tidal deformation and/or the rotation rate of the fluid are large enough. Moreover, the amplitude of the instability for a centrally-condensed mass of fluid is of the same order of magnitude as for an incompressible fluid for a given distance to the threshold of the instability. Finally, we show that the assumption of the elliptical instability being the main tidal dissipation process in eccentric inflated hot Jupiters and misaligned stars is consistent with current data.

Cébron, David; Bars, Michael Le; Gal, Patrice Le; Moutou, Claire; Leconte, Jeremy; Sauret, Alban

2013-11-01

413

Astronaut Jack Lousma taking hot bath  

NASA Technical Reports Server (NTRS)

A closeup view of Astronaut Jack R. Lousma, Skylab 3 pilot, taking a hot bath in the crew quarters of the Orbital Workshop (OWS) of the Skylab space station cluster in Earth orbit. In deploying the shower facility, the shower curtain is pulled up from the floor and attached to the ceiling. The water comes through a push-button shower head attached to a flexible hose. Water is drawn off by a vacuum system.

1973-01-01

414

Drowning and the Influence of Hot Weather  

PubMed Central

Background Drowning deaths are devastating and preventable. Public perception does not regard hot weather as a common scenario for drowning deaths. The objective of our study was to test the association between hot weather and drowning risk. Materials and Methods We conducted a retrospective case-crossover analysis of all unintentional drowning deaths in Ontario, Canada from 1999 to 2009. Demographic data were obtained from the Office of the Chief Coroner. Weather data were obtained from Environment Canada. We used the pair-matched analytic approach for the case-crossover design to contrast the weather on the date of the drowning with the weather at the same location one week prior (control period). Results We identified 1243 drowning deaths. The mean age was 40 years, 82% were male, and most events (71%) occurred in open water. The pair-matched analytic approach indicated that temperatures exceeding 30°C were associated with a 69% increase in the risk of outdoor drowning (OR?=?1.69, 95% CI 1.23–2.25, p?=?0.001). For indoor drowning, however, temperatures exceeding 30°C were not associated with a statistically significant increase in the risk of drowning (OR?=?1.50, 95% CI 0.53–4.21, p?=?0.442). Adult men were specifically prone to drown in hot weather (OR 1.67, 95% CI 1.19–2.34, p?=?0.003) yet an apparent increase in risk extended to both genders and all age groups. Conclusion Contrary to popular belief, hot weather rather than cold stormy weather increases the risk of drowning. An awareness of this risk might encourage greater use of drowning prevention strategies known to save lives.

Fralick, Michael; Denny, Christopher J.; Redelmeier, Donald A.

2013-01-01

415

A SOLIDS FILTER FOR HOT CORROSIVE GASES  

Microsoft Academic Search

The unit was used to remove suspended solids of 1.5 microns average ; particle size from a hot dry air stream. The pressure drop across the clean ; filter was 1.2 lb\\/sq. in.\\/in. of filter thickness. The filter gave very good ; Cake deposits of approximateiy 0.03-inch thickness were obtained with only a 75 ; per cent increase in the

1958-01-01

416

THERMAL PROCESSES GOVERNING HOT-JUPITER RADII  

SciTech Connect

There have been many proposed explanations for the larger-than-expected radii of some transiting hot Jupiters, including either stellar or orbital energy deposition deep in the atmosphere or deep in the interior. In this paper, we explore the important influences on hot-Jupiter radius evolution of (1) additional heat sources in the high atmosphere, the deep atmosphere, and deep in the convective interior; (2) consistent cooling of the deep interior through the planetary dayside, nightside, and poles; (3) the degree of heat redistribution to the nightside; and (4) the presence of an upper atmosphere absorber inferred to produce anomalously hot upper atmospheres and inversions in some close-in giant planets. In particular, we compare the radius expansion effects of atmospheric and deep-interior heating at the same power levels and derive the power required to achieve a given radius increase when night-side cooling is incorporated. We find that models that include consistent day/night cooling are more similar to isotropically irradiated models when there is more heat redistributed from the dayside to the nightside. In addition, we consider the efficacy of ohmic heating in the atmosphere and/or convective interior in inflating hot Jupiters. Among our conclusions are that (1) the most highly irradiated planets cannot stably have uB {approx}> 10 km s{sup -1} G over a large fraction of their daysides, where u is the zonal wind speed and B is the dipolar magnetic field strength in the atmosphere, and (2) that ohmic heating cannot in and of itself lead to a runaway in planet radius.

Spiegel, David S. [Astrophysics Department, Institute for Advanced Study, Princeton, NJ 08540 (United States); Burrows, Adam, E-mail: dave@ias.edu, E-mail: burrows@astro.princeton.edu [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544 (United States)

2013-07-20

417

Hot Electron-Induced Electrogenerated Chemiluminescence  

Microsoft Academic Search

\\u000a In this chapter, we discuss the basics of cathodic hot electron-induced electrogenerated chemiluminescence (HECL). In the\\u000a applications of HECL, we discuss, e.g., the usable electrode materials and their advantages as well as the applicable solution\\u000a conditions in aqueous media. We also summarize the luminophore types excitable by this method and their usability as labels\\u000a in practical bioaffinity assay applications.

Johanna Suomi; Sakari Kulmala

418

Turbine Engine Hot Section Technology, 1984  

NASA Technical Reports Server (NTRS)

Presentations were made concerning the hot section environment and behavior of combustion liners, turbine blades, and waves. The presentations were divided into six sessions: instrumentation, combustion, turbine heat transfer, structural analysis, fatigue and fracture, and surface properties. The principal objective of each session was to disseminate research results to date, along with future plans. Topics discussed included modeling of thermal and fluid flow phenomena, structural analysis, fatigue and fracture, surface protective coatings, constitutive behavior, stress-strain response, and life prediction methods.

1984-01-01

419

Possible evidence for shocks in hot cores  

Microsoft Academic Search

The NS\\/CS ratio can be used to test if shocks or thermal evaporation remove grain ices during massive star formation. The two scenarios lead to differences in the subsequent chemistry: in particular, timescales are shorter if shocks are present. We have measured NS\\/CS ratios in six hot core sources through observation of high excitation NS, N34S, C34S and C33S with

J. Hatchell; S. Viti

2002-01-01

420

Atmospheres of Hot Super-Earths  

Microsoft Academic Search

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

Thibaut Castan; Kristen Menou

2011-01-01

421

Terahertz superconducting hot-electron bolometer mixers  

Microsoft Academic Search

Hot-electron bolometer frequency down-converters (mixers) based on superconducting films have been found to offer record sensitivity for THz receivers to be used in radio astronomy. In this paper we focus on mixers using NbN phonon-cooled devices. We show that recent theoretical models predict a performance that agrees well with experiments. Important mixer properties such as conversion efficiency, noise (sensitivity), and

S. Cherednichenko; P. Khosropanah; E. Kollberg; M. Kroug; H. Merkel

2002-01-01

422

Terahertz Superconducting Hot Electron Bolometer Heterodyne Receivers  

Microsoft Academic Search

We highlight the progress on NbN hot electron bolometer (HEB) mixers achieved through fruitful collaboration between SRON Netherlands Institute for Space Research and Delft University of Technology, the Netherlands. This includes the best receiver noise temperatures of 700 K at 1.63 THz using a twin-slot antenna mixer and 1050 K at 2.84 THz using a spiral antenna coupled HEB mixer.

J. R. Gao; M.. Hajenius; Z. Q. Yang; J. J. A. Baselmans; P.. Khosropanah; R.. Barends; T. M. Klapwijk

2007-01-01

423

Hot filament CVD of boron nitride films  

DOEpatents

Using a hot filament (.apprxeq.1400.degree. C.) to activate borazine (B.sub.3 N.sub.3 H.sub.6) molecules for subsequent reaction with a direct line-of-sight substrate, transparent boron ntiride films as thick as 25,000 angstroms are grown for a substrate temperature as low as 100.degree. C. The minimum temperature is determined by radiative heating from the adjacent hot filament. The low temperature BN films show no indication of crystallinity with X-ray diffraction (XRD). X-ray photoelectron spectra (XPS) show the films to have a B:N ratio of 0.97:1 with no other XPS detectable impurities above the 0.5% level. Both Raman and infrared (IR) spectroscopy are characteristic of h-BN with small amounts of hydrogen detected as N-H and B-H bands in the IR spectrum. An important feature of this method is the separation and localization of the thermal activation step at the hot filament from the surface reaction and film growth steps at the substrate surface. This allows both higher temperature thermal activation and lower temperature film growth.

Rye, Robert R. (Albuquerque, NM)

1992-01-01

424

Carcinogenic risk of hot-particle exposures.  

PubMed

It has been suggested that spatially non-uniform radiation exposures, such as those from small radioactive particles ('hot particles'), may be very much more carcinogenic than when the same amount of energy is deposited uniformly throughout a tissue volume. This review provides a brief summary of in vivo and in vitro experimental findings, and human epidemiology data, which can be used to evaluate the veracity of this suggestion. Overall, this supports the contrary view and indicates that average dose, as advocated by the ICRP, is likely to provide a reasonable estimate of carcinogenic risk (within a factor of approximately +/- 3). There are few human data with which to address this issue. The limited data on lung cancer mortality following occupational inhalation of plutonium aerosols, and the incidence of liver cancer and leukaemia due to thorotrast administration for clinical diagnosis, do not appear to support a significant enhancement factor. Very few animal studies, including mainly lung and skin exposures, provide any indication of a hot-particle enhancement for carcinogenicity. Some recent in vitro malignant transformation experiments provide evidence foran enhanced cell transformation for hot-particle exposures but, properly interpreted, the effect is modest. Few studies extend below absorbed doses of approximately 0.1 Gy. PMID:12729416

Charles, M W; Mill, A J; Darley, P J

2003-03-01

425

Hot Ammonia in the Densest Massive Cores  

NASA Astrophysics Data System (ADS)

Hot molecular cores are believed to be the birthplace of high-mass (O-B type) stars. Their formation process is however still a matter of debate, chiefly owing to the lack of observational evidence of accreting O-type young stars. In this context, imaging of optically-thin, highly-excited molecular lines at cm-wavelengths provide the best tool for probing the hottest and densest gas at small radii from O-type forming stars, i.e. in centrifugally-supported disks and/or infalling envelopes, whose innermost regions can be inaccessible even to (sub)mm interferometry because of large optical depth of dust emission. In particular, ammonia is an excellent "thermometer" of dense molecular gas and it can trace excitation up to temperatures of 2000 K by observing its inversion transitions within a relatively narrow frequency range, 20-40 GHz, which are sensitive to gas of different temperatures and densities. I will report initial results from an imaging survey of hot-cores in the Galaxy in the ammonia lines from (6,6) up to (14,14) with the JVLA. Towards NGC7538 IRS1 and W51, the multi-transition data sets enabled us to identify the densest massive hot cores known and to probe kinematics of rotating disks and infalling envelopes around O-type young stars.

Goddi, CiriacoIVE); Zhang, Qizhou

2014-07-01

426

High temperature hot water distribution system study  

SciTech Connect

The existing High Temperature Hot Water (HTHW) Distribution System has been plagued with design and construction deficiencies since startup of the HTHW system, in October 1988. In October 1989, after one year of service, these deficiencies were outlined in a technical evaluation. The deficiencies included flooded manholes, sump pumps not hooked up, leaking valves, contaminated HTHW water, and no cathodic protection system. This feasibility study of the High Temperature Hot Water (HTHW) Distribution System was performed under Contract No. DACA0l-94-D-0033, Delivery Order 0013, Modification 1, issued to EMC Engineers, Inc. (EMC), by the Norfolk District Corps of Engineers, on 25 April 1996. The purpose of this study was to determine the existing conditions of the High Temperature Hot Water Distribution System, manholes, and areas of containment system degradation. The study focused on two areas of concern, as follows: * Determine existing conditions and areas of containment system degradation (leaks) in the underground carrier pipes and protective conduit. * Document the condition of underground steel and concrete manholes. To document the leaks, a site survey was performed, using state-of-the-art infrared leak detection equipment and tracer gas leak detection equipment. To document the condition of the manholes, color photographs were taken of the insides of 125 manholes, and notes were made on the condition of these manholes.

NONE

1996-12-01

427

Hot-Gas Filter Ash Characterization Project  

SciTech Connect

Large-scale hot-gas filter testing over the past 10 years has revealed numerous cases of cake buildup on filter elements that has been difficult, if not impossible, to remove. At times, the cake can blind or bridge between candle filters, leading to filter failure. Physical factors, including particle-size distribution, particle shape, the aerodynamics of deposition, and system temperature, contribute to the difficulty in removing the cake, but chemical factors such as surface composition and gas-solid reactions also play roles in helping to bond the ash to the filters or to itself. This project is designed to perform the research necessary to determine the fuel-, sorbent-, and operations-related conditions that lead to blinding or bridging of hot-gas particle filters. The objectives of the project are threefold: (1) Determine the mechanisms by which a difficult-to-clean ash is formed and how it bridges hot-gas filters (2) Develop a method to determine the rate of bridging based on analyses of the feed coal and sorbent, filter properties, and system operating conditions and (3) Suggest and test ways to prevent filter bridging.

Swanson, M.L.; Hurley, J.P.; Dockter, B.A.; O`Keefe, C.A.

1997-07-01

428

Superthermal electron production from hot underdense plasmas  

SciTech Connect

Very-high-energy electrons of up to an energy of approx.2.3 MeV have been observed to be emitted from the hot underdense exploding thin foil plasmas created by 10.6 ..mu..m CO/sub 2/ laser radiation at intensity levels up to approx.4 x 10/sup 14/ W/cm/sup 2/. As a supplement to the electron measurements the forward and backward scattered light components were also measured. Correlation of these measurements shows that either Raman scattering or the high-temperature version of two-plasmon decay or both, manifesting themselves near the quarter-critical density region, are responsible for the production of a hot (T/sub h/approx.135 keV) tail of electrons at least up to energies of 1 MeV. There are no indications that the Raman forward scattering (as distinct from Raman backward scattering) at lower densities plays any significant role. These experimental results are consistent with the results from a l 1/2 -dimensional particle-in-cell code simulation with a parabolic density profile resembling the experimental conditions. An apparent anomaly is discussed, which is that hot electrons are produced (both in experiments and simulations) at energies higher than the trapping value appropriate to electron plasma waves whose phase velocity is equal to the matching value (C/(3)/sup 1/2/) at the turning point for the light of half the laser frequency.

Aithal, S.; Lavigne, P.; Pepin, H.; Johnston, T.W.; Estabrook, K.

1987-12-01

429

ACCRETION OF ROCKY PLANETS BY HOT JUPITERS  

SciTech Connect

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.

Ketchum, Jacob A.; Adams, Fred C.; Bloch, Anthony M. [Michigan Center for Theoretical Physics, Physics Department, University of Michigan, Ann Arbor, MI 48109 (United States)

2011-11-01

430

Archaeal diversity in Icelandic hot springs.  

PubMed

Whole-cell density gradient extractions from three solfataras (pH 2.5) ranging in temperature from 81 to 90 degrees C and one neutral hot spring (81 degrees C, pH 7) from the thermal active area of Hveragerethi (Iceland) were analysed for genetic diversity and local geographical variation of Archaea by analysis of amplified 16S rRNA genes. In addition to the three solfataras and the neutral hot spring, 10 soil samples in transects of the soil adjacent to the solfataras were analysed using terminal restriction fragment length polymorphism (t-RFLP). The sequence data from the clone libraries in combination with 14 t-RFLP profiles revealed a high abundance of clones clustering together with sequences from the nonthermophilic I.1b group of Crenarchaeota. The archaeal diversity in one solfatara was high; 26 different RFLP patterns were found using double digestion of the PCR products with restriction enzymes AluI and BsuRI. The sequenced clones from this solfatara belonged to Sulfolobales, Thermoproteales or were most closest related to sequences from uncultured Archaea. Sequences related to group I.1b were not found in the neutral hot spring or the hyperthermophilic solfatara (90 degrees C). PMID:17014681

Kvist, Thomas; Ahring, Birgitte K; Westermann, Peter

2007-01-01

431

Residential hot water distribution systems: Roundtablesession  

SciTech Connect

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.

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

2002-08-01

432

Toward improved durability in advanced aircraft engine hot sections  

NASA Technical Reports Server (NTRS)

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.

Sokolowski, Daniel E. (editor)

1989-01-01

433

Whistler Solitons in Plasma with Anisotropic Hot Electron Admixture  

NASA Technical Reports Server (NTRS)

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.

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

1999-01-01

434

Amorphous-silicon module hot-spot testing  

NASA Technical Reports Server (NTRS)

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.

Gonzalez, C. C.

1985-01-01

435

Cold Friends of Hot Jupiters: AO Survey  

NASA Astrophysics Data System (ADS)

Hot Jupiters” are a class of gas giant planets found in extrasolar systems at very small orbital distances (?0.05 AU). We know that these planets could not have formed at their present locations, but must instead have migrated in from beyond the ice line. One class of proposed migration mechanisms for these planets involve gravitational perturbations from a distant stellar companion. These same processes also provide a natural explanation for the existence of a subset of hot Jupiters that have been observed to have orbits that are highly misaligned with respect to their star's spin axis and/or have large orbital eccentricities. In the "Cold Friends" survey, we search for stellar companions around 51 stars known to host hot Jupiters in order to determine whether stellar companions play an important role in hot Jupiter migration. Our survey consists of a population of stars with planets that have eccentric and/or misaligned orbits as well as a control population of planets with well-aligned and circular orbits. This project searches for companion stars (the "Cold Friends") in three detection modes: radial velocity monitoring, high resolution IR spectroscopy (presented by D. Piskorz et al. at this meeting), and adaptive optics (AO) imaging at infrared wavelengths (presented here). The AO mode is sensitive to the most distant companions (separations of 50-200 AU and beyond) while the other modes are effective at finding companions at smaller separations. We present the results of our AO survey and discuss the binary fraction found in our sample. Out of our total sample of 51 stars, 19 candidate companions (many of which have not been observed before) were directly imaged around 17 stars. We also describe follow-up photometry and astrometry of all detected companions to determine whether or not they are gravitationally bound to the primary planet-hosting star. If such companions are common, it would suggest that perturbations from stellar companions may play a significant role in the evolution of hot Jupiter systems.

Ngo, Henry; Knutson, H. A.; Hinkley, S.; Crepp, J. R.; Batygin, K.; Howard, A. W.; Johnson, J. A.; Morton, T. D.; Muirhead, P. S.

2013-10-01

436

Hot Particles of the Second Kind in Flood Lands of the Yenisei River  

Microsoft Academic Search

Specific modification of hot particles found in flood-land soils of the Yenisei River was studied. In contrast to the known hot particles (hot particles of the first kind), newly found hot particles are referred to as hot particles of the second kind. Abundance, radionuclide composition, and other characteristics of hot particles of the first and second kinds are compared.

Z. G. Gritchenko; Yu. V. Kuznetsov; V. K. Legin; V. N. Strukov; B. F. Myasoedov; A. P. Novikov; A. E. Shishlov; Yu. V. Savitskii

2001-01-01

437

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

438

Effect of hot pressing additives on the leachability of hot pressed sodium hydrous titanium oxide  

SciTech Connect

Sodium hydrous titanium oxide is an ion exchange resin which can be used for immobilizing medium level waste (MLW) liquors. When hot pressed, it undergoes conversion to a ceramic. Three low melting point materials (borax, bismuth trioxide, and a mixture of PbO/CuO) were added to the (Na)HTiO and the effect that each of these had on aiding densification was assessed. Hot pressing temperature, applied pressure, and percentage addition of hot pressing aid were varied. Percentage open porosity, flexural strength, and leachability were measured. There was a linear relationship between the percentage open porosity and the logarithm of the leach rate for a constant percentage addition of each additive.

Valentine, T.M.; Sambell, R.A.J.

1980-01-01

439

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

440

Yttrium. alpha. -sialon ceramics by hot isostatic pressing and post-hot isostatic pressing  

Microsoft Academic Search

This paper reports on dense α-sialon materials that were produced by hot isostatic pressing (HIP) and post-hot isostatic pressing (post-HIP) using composition with the formula Yâ(Si{sub 12-4.5x}), Al{sub 4.5x}-O{sub 1.5x},N{sub 16-1.5x} with 0.1 ⤠x ⤠0.9 and with the same compositions with extra additions of yttria and aluminum nitride. X-ray diffraction analyses show how the phase content changes from

Alena Bartek; T. Johansson; T. Ekstrom; H. Herbertsson

1992-01-01

441

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

442

Advanced hot-gas filter development  

SciTech Connect

Coal is the most abundant fossil-fuel resource in the United States. `Clean coal` technologies, such as pressurized fluidized-bed combustion (PFBC) and integrated gasification combined-cycle (IGCC), require a hot gas filter to remove the corrosive and erosive coal ash entrained in the combustion gas stream. These hot gas filters, or candle filters, must be cost-effective while able to withstand the effects of corrosion, elevated temperature, thermal shock, and temperature transients. Ash loadings may range from 500 to 10,000 ppm by weight, and may contain particles as fine as 0.008 mils. The operating environment for the hot gas filter can range in pressure from 10 to 20 atm, in temperatures from 700 to 1750{degrees}F, and can be oxidizing or reducing. In addition, the process gases may contain volatile chloride, sulfur, and alkali species. Field testing of various commercially available, porous, ceramic filter matrices has demonstrated a loss of up to 50 percent of as-manufactured strength after 1,000 to 2,000 hours of exposure to these operating conditions, although full-scale elements have remained intact during normal process operations. Ultramet, a small business specializing in advanced materials R&D, has developed a new class of hot gas filter materials that offers lower back-pressure, higher permeability, longer life, and high filtration efficiency in the PFBC and IGCC environments. Subscale Ultrafoam Duplex Filter elements have undergone accelerated corrosion testing at temperatures of up to 2370{degrees}F (at Ultramet), and have been subjected to over 2,800 hours of exposure to hot PFBC gases (in the Westinghouse Advanced Particulate Filtration System at Brilliant, OH) without any loss in strength in either case. The Ultrafoam Duplex Filter matrix demonstrated 100 percent particle- capture efficiency of coal ash, and had an initial pressure drop of 0.1 to 0.6 in-wc/fpm. The Ultrafoam Duplex Filter is composed of a chemical vapor deposition (CVD), silicon carbide (SiC), reticulated, open-cell foam filter body supporting a porous mullite membrane filter. The reticulated foam structure is 70 to 90 percent porous, enabling high permeability, while the 3-D interconnected cellular lattice resists crack propagation. The CVD SiC material is fine-grained for maximum strength and corrosion resistance, and has no binders or impurities. The porous, mullite, membrane filter is impregnated into the outer surface of the CVD SiC Ultrafoam filter element. The membrane bonds to the foam ligaments, while the foam ligaments reinforce and support the membrane. The mullite membrane, which acts as a barrier filter, is resistant to thermal shock and corrosion. The thin membrane minimizes pressure drop and thermal gradients. The composite Ultrafoam Duplex Filter was designed to combine optimal material selection with functional structural design to maximize corrosion resistance, thermal shock resistance, strength, toughness, and life while minimizing pressure drop and weight. Oxidation rate, corrosion resistance, creep strength, compressive strength, and C-ring strength of the CVD SiC Ultrafoam filter body, and pressure drop and filtration efficiency for subscale Ultrafoam Duplex Filter elements, are reported. Future work is targeted at the construction of full-scale hot gas filters, and will include further strength and accelerated corrosion testing of subscale sections of the filter body, the membrane, and the composite duplex filter elements.

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

1997-12-31

443

[History of hot spring bath treatment in China].  

PubMed

As early as the 7th century B.C. (Western Zhou Dynasty), there is a recording as 'spring which contains sulfur could treat disease' on the Wentang Stele written by WANG Bao. Wenquan Fu written by ZHANG Heng in the Easten Han Dynasty also mentioned hot spring bath treatment. The distribution of hot springs in China has been summarized by LI Daoyuan in the Northern Wei Dynasty in his Shuijingzhu which recorded hot springs in 41 places and interpreted the definition of hot spring. Bencao Shiyi (by CHEN Cangqi, Tang Dynasty) discussed the formation of and indications for hot springs. HU Zai in the Song Dynasty pointed out distinguishing hot springs according to water quality in his book Yuyin Conghua. TANG Shenwei in the Song Dynasty noted in Jingshi Zhenglei Beiji Bencao that hot spring bath treatment should be combined with diet. Shiwu Bencao (Ming Dynasty) classified hot springs into sulfur springs, arsenicum springs, cinnabar springs, aluminite springs, etc. and pointed out their individual indications. Geologists did not start the work on distribution and water quality analysis of hot springs until the first half of the 20th century. There are 972 hot springs in Wenquan Jiyao (written by geologist ZHANG Hongzhao and published in 1956). In July 1982, the First National Geothermal Conference was held and it reported that there were more than 2600 hot springs in China. Since the second half of the 20th century, hot spring sanatoriums and rehabilitation centers have been established, which promoted the development of hot spring bath treatment. PMID:22169492

Hao, Wanpeng; Wang, Xiaojun; Xiang, Yinghong; Gu Li, A Man; Li, Ming; Zhang, Xin

2011-07-01

444

Hot flashes and cardiac vagal control during women's daily lives  

PubMed Central

Objective The physiology of menopausal hot flashes is not well understood. The autonomic nervous system may play a role in hot flashes, but the current understanding is limited. We previously demonstrated in the laboratory that decreases in high frequency heart rate variability, an index of cardiac vagal control, occur during hot flashes relative to preceding and following periods. In the present study, we tested whether we would observe a similar phenomenon in the ambulatory setting. We additionally considered respiratory rate in these associations. Methods 21 peri- and postmenopausal women ages 40–60 reporting daily hot flashes were monitored both for physiologic and reported hot flashes and heart rate variability over a 24-hour period as they went about their daily lives. Heart rate variability estimates were derived using the band-limited variance method. The interval during the hot flash was compared to two non-flash periods prior to and following the hot flash via mixed effects models. Results Heart rate variability significantly decreased during hot flashes relative to periods preceding (b=0.31, SE=0.03 p<0.0001) and following (b=0.30, SE=0.03, p<0.0001) physiologic hot flashes (covariates: age, race, education, menopausal status, physical activity, body mass index, anxiety). Findings were comparable considering self-reported hot flashes. Findings persisted controlling for respiratory rate. Conclusions Significant decreases in cardiac vagal control occurred during hot flashes assessed during women’s daily lives. These findings extend our work in the laboratory to the ambulatory setting, further shedding light on the physiology of hot flashes and underscoring a potential role of parasympathetic function in hot flashes.

Thurston, Rebecca C.; Christie, Israel C.; Matthews, Karen A.

2011-01-01

445

Hot Gas Desulfurization Using Transport Reactors  

SciTech Connect

Sierra Pacific Power Company is building a 100 MW, IGCC power plant based on KRW fluid bed gasifier technology that utilizes transport reactors for hot gas desulfurization and sorbent regeneration. Use of a transport absorber avoids the need for pre-filtration of dust-laden gasifier effluent, while a transport regenerator allows for the use of 100% air without the need for heat exchange equipment. Selection of transport reactors for hot gas desulfurization using a proprietary sorbent, based on testing performed in a transport reactor test unit (TRTU) at the M. W. Kellogg Technology Development Center and in a fixed bed reactor at Morgantown Energy Technology Center (METC), is outlined. The results obtained in these two test facilities and reasons for selecting transport reactors for the IGCC power plant in preference to either fixed bed or fluidized bed reactors are discussed. This paper reviews the evolution of the hot gas desulfurization system designs and includes selected results on H{sub 2}S absorption and regeneration of sulfided sorbent over several absorption/regeneration cycles conducted in the TRTU and the METC fixed bed reactor. The original design for the Sierra Pacific Project was based on fixed bed reactors with zinc ferrite as the sorbent. Owing to the high steam requirements of this sorbent, zinc titanate was selected and tested in a fixed bed reactor and was found unacceptable due to loss of strength on cyclic absorption/regeneration operation. Another sorbent evaluated was Z-Sorb{reg_sign}, a proprietary sorbent developed by Phillips Petroleum Company, was found to have excellent sulfur capacity, structural strength and regenerability. Steam was found unsuitable as fixed bed regenerator diluent, this results in a requirement for a large amount of inert gas, whereas a transport regenerator requires no diluent. The final Sierra design features transport reactors for both desulfurization and regeneration steps using neat air. 3 refs., 3 figs., 2 tabs.

Moorehead, E.L. [Kellogg (M.W.) Technology Co., Houston, TX (United States)

1996-12-31

446

Models of Hot Cores with Complex Molecules  

NASA Astrophysics Data System (ADS)

Recent models of hot cores have incorporated previously-uninvestigated chemical pathways that lead to the formation of complex organic molecules (COMs; i.e. species containing six or more atoms). In addition to the gas-phase ion-molecule reactions long thought to dominate the organic chemistry in these regions, these models now include photodissociation-driven grain surface reaction pathways that can also lead to COMs. Here, simple grain surface ice species photodissociate to form small radicals such as OH, CH3, CH2OH, CH3O, HCO, and NH2. These species become mobile at temperatures above 30 K during the warm-up phase of star formation. Radical-radical addition reactions on grain surfaces can then form an array of COMs that are ejected into the gas phase at higher temperatures. Photodissociation experiments on pure and mixed ices also show that these complex molecules can indeed form from simple species. The molecules predicted to form from this type of chemistry reasonably match the organic inventory observed in high mass hot cores such as Sgr B2(N) and Orion-KL. However, the relative abundances of the observed molecules differ from the predicted values, and also differ between sources. Given this disparity, it remains unclear whether grain surface chemistry governed by photodissociation is the dominant mechanism for the formation of COMs, or whether other unexplored gas-phase reaction pathways could also contribute significantly to their formation. The influence that the physical conditions of the source have on the chemical inventory also remains unclear. Here we overview the chemical pathways for COM formation in hot cores. We also present new modeling results that begin to narrow down the possible routes for production of COMs based on the observed relative abundances of methyl formate (HCOOCH3) and its C2H4O2 structural isomers.

Widicus Weaver, Susanna L.; Garrod, Robin T.; Laas, Jacob C.; Herbst, Eric

2011-12-01

447

Axion emission from a hot plasma  

NASA Astrophysics Data System (ADS)

We give the technics for the calculation of production and energy loss rates for axion-like particles (scalar or pseudo-scalar coupling to the gauge boson) from a hot QED (or QCD) heat bath. We compute the contribution coming from, the decay mode of a transverse to a longitudinal photon (or gluon). The energy loss rate for this process behaves as T 7. Considering the supernova SN1987A event, this behaviour could improve the upper bound on the coupling constant between asions and photons.

Altherr, T.

1990-12-01

448

A Versatile Rocket Engine Hot Gas Facility  

NASA Technical Reports Server (NTRS)

The capabilities of a versatile rocket engine facility, located in the Rocket Laboratory at the NASA Lewis Research Center, are presented. The gaseous hydrogen/oxygen facility can be used for thermal shock and hot gas testing of materials and structures as well as rocket propulsion testing. Testing over a wide range of operating conditions in both fuel and oxygen rich regimes can be conducted, with cooled or uncooled test specimens. The size and location of the test cell provide the ability to conduct large amounts of testing in short time periods with rapid turnaround between programs.

Green, James M.

1993-01-01

449

SSME hot gas manifold flow comparison test  

NASA Technical Reports Server (NTRS)

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.

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

1988-01-01

450

Automated inspection of hot steel slabs  

DOEpatents

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.

Martin, Ronald J. (Burnsville, MN)

1985-01-01

451

Automated inspection of hot steel slabs  

DOEpatents

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.

Martin, R.J.

1985-12-24

452

Hot Colors -- Windows into Hidden Worlds  

NSDL National Science Digital Library

This website contains an electronic field trip based on Yellowstone National Park's hot springs and the microorganisms living in them. The site includes a link for teachers providing an introduction, overview of concepts explored in the trip, lesson plans, and additional web links. The electronic field trip may be viewed in a low bandwidth version without downloading. For a high bandwith version of the field trip, Macromedia Flash Player is required and can be downloaded on site. Further information on system requirements and field trip procedures are outlined on the website as well.

2010-05-11

453

Hot cell shield plug extraction apparatus  

DOEpatents

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.

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

1995-01-01

454

6.NS Making Hot Cocoa, Variation 2  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: A recipe for hot chocolate calls for 3 cups of milk. What fraction of the recipe can Nelli make with $\\frac23$ cups of milk? Solve the problem by drawi...

455

6.NS Making Hot Cocoa, Variation 1  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: One mug of hot chocolate uses $\\frac23$ cup of cocoa powder. How many mugs can Nelli make with 3 cups of cocoa powder? Solve the problem by drawing a p...

456

Chemical identifications of possible martian hot spots  

NASA Astrophysics Data System (ADS)

If the interpretation of certain Mars Global Surveyor images indicating recent ground water seepage and surface runoff (1) is correct, it may imply that Mars can still be active internally in some places from time to time, and outgassing of certain molecules from the interior could occur with or without the water seepage. Although there is no evidence of active volcanism on Mars today, ``localized'' outgassing sources, the ``hot spots'', may not be ruled out. If outgassing does occur somewhere on Mars, water, carbon dioxide, sulfur species, methane, and to a lesser extent, halogens, would be the likely molecules of outgassing, based on the terrestrial analogs. The sulfur species, methane and halogens have not been detected in the ``global'' observations of Mars. Considering the possibility of outgassing from some localized hot spots, we have developed a one-dimensional photochemical model (2) that includes methane (CH_4), sulfur dioxide (SO_2) and hydrogen sulfide (H_2S), starting with their current ``global average'' upper limits of, respectively, 0.02, 0.1 and 0.1 ppm at the surface, and then progressively increasing their abundances above possible hot spots. Halogens are neglected as they are a minor product of the terrestrial outgassing sources. We find that the introduction of methane into the martian atmosphere results in the formation of mainly formaldehyde, methyl alcohol (CH_3OH) and ethane (C_2H_6), whereas the introduction of the sulfur species produces mainly sulfur monoxide (SO) and sulfuric acid (H_2SO_4). In a relatively short time of an hour, ordinary convective processes alone can reduce the mixing ratios of outgassed species by factors of 10^4 -- 10^5 approximately 50 km from the source, and the time for spreading the source material more or less uniformly over the planet (with corresponding dilution factor of ˜10^8) would be approximately one year. Depending upon the flux of the outgassed molecules from possible hot spots, some of these species, especially CH_4, SO_2, H_2S, and perhaps CH_2O, may be detectable locally, either by remote sensing or in situ measurements. References: (1) Malin, M. C. and K. S. Edgett, Science 288, 2330, 2000; (2) Wong, A. S., S. K. Atreya, and Th. Encrenaz, J. Geophys. Res., in press, 2003.

Wong, A. S.; Atreya, S. K.; Renno, N. O.

2003-04-01

457

Prototype solar domestic hot water systems  

NASA Technical Reports Server (NTRS)

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.

1978-01-01

458

Hot air drum evaporator. [Patent application  

DOEpatents

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

Black, R.L.

1980-11-12

459

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

National Technical Information Service (NTIS)

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 wast...

K. M. Walterskirchen

1997-01-01

460

Kelley Hot Spring Geothermal Project: Kelly Hot Spring Agricultural Center conceptual design  

Microsoft Academic Search

The proposed core activity in the Kelly Hot Spring Agricultural Center is a nominal 1200 sow swine raising complex. The swine raising is to be a totally confined operation for producing premium pork in controlled environment facilities that utilize geothermal energy. The complex will include a feedmill for producing the various feed formulae required for the animals from breeding through

Longyear

1980-01-01

461

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

Microsoft Academic Search

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

Thomas Henry Culhane

2010-01-01

462

Exposure limits of women in hot environment.  

PubMed

The tolerance of six women to work in hot environments was examined under four environmental conditions from 38 to 44 degrees C dry bulb temperature and 50 to 80 per cent relative humidity, i.e., 32 to 36.5 degrees C effective temperature [ET (normal scale)] in a climatic chamber. The subjects performed bicycle ergometric work at an intensity of 50 W and the exposure duration was determined by the cardiorespiratory, body temperature and sweating responses. At the limit of tolerance, the body core temperature (Tcr) reached over 38.5 degrees C and the heart rates attained a peak level (i.e., about 172 beats/min). The total oxygen demand decreased significantly with higher environmental load, particularly beyond 33.5 degrees C ET (N). While the tolerance time decrement was evident with the higher heat stress, on an average, an increase or decrease of every liter of total oxygen demand was equivalent to a 0.8 min change in the tolerance time. As such, the women volunteers were not susceptible to heat; only in extreme hot situations beyond 33.5 degrees C ET (N), they had unacceptable levels of physiological and psychophysical reactions. Based on the distribution of tolerance time of the women in different exposure conditions, the safe exposure times were estimated, which varied from 43 min [32.0 degrees C ET (N)] to 16 min [36.5 degrees C ET (N)]. PMID:10645102

Nag, A; Kothari, D; Desai, H

1999-10-01

463

Deep drilling technology for hot crystalline rock  

SciTech Connect

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.

Rowley, J.C.

1984-01-01

464

Hot Dog and Butterfly, Nereidum Montes  

NASA Technical Reports Server (NTRS)

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.

1999-01-01

465

Hot electron generation during ICF target compression  

NASA Astrophysics Data System (ADS)

Yield degradation in ICF experiments is commonly attributed to hydrodynamic instabilities developed during shell implosion.. Preheating of the fuel shell due to the hot electrons generated by the drive laser could be a potential source of an additional yield reduction. A PIC code OSIRIS is used to simulate the laser-plasma interactions and hot electron generation in two- dimensional space. For a typical run, the laser intensity is 3 x10^15 W/cm^2 (?=0.353 ?m) with a spot size of 3.4 ?m. The density profile, taken from the simulations using hydrocode LILAC, changes from 0 to 0.3 nc in 300 ?m. The simulation box is 300 ?m in x direction and 12 ?m in y direction and the simulation time is up to 1.5 ps. Parametric instabilities such as Raman scattering and two-plasmon decay will be studied. Laser absorption and electron energy spectra in this regime will be presented.

Ren, Chuang

2005-10-01

466

Characterizing the Hot Kepler Objects of Interest  

NASA Astrophysics Data System (ADS)

Planets around retired A stars (hot stars that have evolved off the main sequence) have large semimajor axes compared to planets around sun-like stars (e.g. Johnson et al. 2007, Bowler et al. 2010). This could be a side effect of the stars' evolution; increases in tidal dissipation as the stars evolve and expand may lead to the orbital decay and eventual destruction of close-in planets. Alternatively, differences in planet formation processes around these more massive stars may account for their lack of hot Jupiters. To distinguish between these two possibilities, we characterize main sequence A stars with transiting planet candidates detected by Kepler. We identify likely A stars in the Kepler Input Catalog (KIC) by their stellar effective temperatures, derived from KIC grizJHK photometry using the empirical relations from Boyajian et al. (2013). To verify the classification of a subset of these stars, we measure their spectra using Palomar DBSP and collect high-resolution images with Keck NIRC2. We determine the physical parameters of the transiting planets’ orbits by fitting the Kepler transit lightcurves with Markov Chain Monte Carlo methods. By constraining the semi-major axis and eccentricity distributions of planets orbiting A stars, we gain insights into the role of stellar evolution and stellar mass in planetary systems.

Rogers, Leslie; Price, E.; Shporer, A.; Crepp, J. R.; Swift, J.; Muirhead, P. S.; Johnson, J. A.

2014-01-01

467

The origin of retrograde hot Jupiters  

NASA Astrophysics Data System (ADS)

Many hot Jupiters are observed to be misaligned with respect to the rotation axis of the star (as measured through the Rossiter-McLaughlin effect) and some (about ~ 25%) even appear to be in retrograde orbits. We show that the presence of an additional, moderately inclined and eccentric massive planet in the system can naturally explain close, inclined, eccentric, and even retrograde orbits. We have derived a complete and accurate treatment of the secular dynamics including both the key octupole-order effects and tidal friction. The flow of angular momentum from the inner orbit to the orbit of the perturber can lead to both high eccentricities and inclinations, and even flip the inner orbit. In our treatment the component of the inner orbit's angular momentum perpendicular to the stellar equatorial plane can change sign; a brief excurs