National Library of Energy BETA

Sample records for antiknock in dex

  1. Application of charge stratification, lean burn combustion systems and anti-knock control devices in small two-stroke cycle gasoline engines

    SciTech Connect (OSTI)

    Kuentscher, V.

    1986-01-01

    For essentially reducing the specific fuel consumption in two-stroke cycle engines and the concentration of hydrocarbons (HC) in the exhaust gas, the normal engine was equipped with a new ram tuned fuel injection system. By the application of charge stratification, lean burn combustion, different ignition systems and a special anti-knock device, considerable fuel consumption and HC emission reductions were obtained.

  2. DEX: Increasing the Capability of Scientific Data Analysis Pipelines by

    Office of Scientific and Technical Information (OSTI)

    Using Efficient Bitmap Indices to Accelerate Scientific Visualization (Technical Report) | SciTech Connect DEX: Increasing the Capability of Scientific Data Analysis Pipelines by Using Efficient Bitmap Indices to Accelerate Scientific Visualization Citation Details In-Document Search Title: DEX: Increasing the Capability of Scientific Data Analysis Pipelines by Using Efficient Bitmap Indices to Accelerate Scientific Visualization We describe a new approach to scalable data analysis that

  3. DEX: Increasing the Capability of Scientific Data Analysis Pipelines...

    Office of Scientific and Technical Information (OSTI)

    Our architecture and implementation, which we call DEX (short for dexterous data ... COMPUTING, AND INFORMATION SCIENCE; ARCHITECTURE; DATA ANALYSIS; EXPLOSIONS; FOCUSING; ...

  4. CoDEx Project: A Hardware/Software Codesign Environment for the Exascale

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Era Computing » CoDEx Project CoDEx Project: A Hardware/Software Codesign Environment for the Exascale Era The next decade will see a rapid evolution of HPC node architectures as power and cooling constraints are limiting increases in microprocessor clock speeds and constraining data movement. Applications and algorithms will need to change and adapt as node architectures evolve. A key element of the strategy as we move forward is the co-design of applications, architectures and programming

  5. DEX: Increasing

    Office of Scientific and Technical Information (OSTI)

    ... to this approach to visualization as query-driven visual data anal- ysis. Query-driven data analysis methods allow a scientist to define a search criteria as a Boolean expression. ...

  6. Table Definitions, Sources, and Explanatory Notes

    Annual Energy Outlook [U.S. Energy Information Administration (EIA)]

    Octane Rating A number used to indicate gasoline's antiknock performance in motor vehicle engines. The two recognized laboratory engine test methods for determining the antiknock ...

  7. untitled

    Gasoline and Diesel Fuel Update (EIA)

    ... Octane Rating: A number used to indicate gasoline's antiknock performance in motor vehicle engines. The two recognized laboratory engine test methods for determining the antiknock ...

  8. Table Definitions, Sources, and Explanatory Notes

    Annual Energy Outlook [U.S. Energy Information Administration (EIA)]

    antiknock performance in motor vehicle engines. The two recognized laboratory engine test methods for determining the antiknock rating, i.e., octane rating, of gasolines are the...

  9. Dexamethasone increases glucose cycling, but not glucose production, in healthy subjects

    SciTech Connect (OSTI)

    Wajngot, A.; Khan, A.; Giacca, A.; Vranic, M.; Efendic, S. )

    1990-11-01

    We established that measurement of glucose fluxes through glucose-6-phosphatase (G-6-Pase; hepatic total glucose output, HTGO), glucose cycling (GC), and glucose production (HGP), reveals early diabetogenic changes in liver metabolism. To elucidate the mechanism of the diabetogenic effect of glucocorticoids, we treated eight healthy subjects with oral dexamethasone (DEX; 15 mg over 48 h) and measured HTGO with (2-3H)glucose and HGP with (6-3H)glucose postabsorptively and during a 2-h glucose infusion (11.1 mumol.kg-1.min-1). (2-3H)- minus (6-3H)glucose equals GC. DEX significantly increased plasma glucose, insulin, C peptide, and HTGO, while HGP was unchanged. In controls and DEX, glucose infusion suppressed HTGO (82 vs. 78%) and HGP (87 vs. 91%). DEX increased GC postabsorptively (three-fold) P less than 0.005 and during glucose infusion (P less than 0.05) but decreased metabolic clearance and glucose uptake (Rd), which eventually normalized, however. Because DEX increased HTGO (G-6-Pase) and not HGP (glycogenolysis + gluconeogenesis), we assume that DEX increases HTGO and GC in humans by activating G-6-Pase directly, rather than by expanding the glucose 6-phosphate pool. Hyperglycemia caused by peripheral effects of DEX can also contribute to an increase in GC by activating glucokinase. Therefore, measurement of glucose fluxes through G-6-Pase and GC revealed significant early effects of DEX on hepatic glucose metabolism, which are not yet reflected in HGP.

  10. Motor gasolines, Summer 1982

    SciTech Connect (OSTI)

    Shelton, E.M.

    1983-03-01

    The samples were collected from service stations throughout the country and were analyzed in the laboratories of various refiners, motor manufacturers, and chemical companies. The analytical data for 796 samples of motor gasoline, were submitted to the Bartlesville Energy Technology Center for study, necessary calculations, and compilation under a cooperative agreement between the Bartlesville Energy Technology Center (BETC) and the American Petroleum Institute (API). They represent the products of 22 companies, large and small, which manufacture and supply gasoline. These data are tabulated by groups according to brands (unlabeled) and grades for 17 marketing districts into which the country is divided. A map included in this report, shows marketing areas, districts and sampling locations. The report also includes charts indicating the trends of selected properties of motor fuels since 1959. Sixteen octane distribution percent charts for areas 1, 2, 3, and 4 for unleaded antiknock index (R + M)/2 below 90.0, unleaded antiknock index (R + M)/2 90.0 and above, leaded antiknock index (R + M)/2 below 93.0, and leaded antiknock index (R + M)/2 93.0 and above grades of gasoline are presented in this report. The antiknock (octane) index (R + M)/2 averages of gasoline sold in this country were 87.3 for unleaded below 90.0, 91.7 for unleaded 90.0 and above, 89.0 for leaded below 93.0, and no data in this report for 93.0 and above grades of leaded gasoline.

  11. Trends in motor gasolines: 1942-1981

    SciTech Connect (OSTI)

    Shelton, E M; Whisman, M L; Woodward, P W

    1982-06-01

    Trends in motor gasolines for the years of 1942 through 1981 have been evaluated based upon data contained in surveys that have been prepared and published by the Bartlesville Energy Technology Center (BETC). These surveys have been published twice annually since 1935 describing the properties of motor gasolines from throughout the country. The surveys have been conducted in cooperation with the American Petroleum Institute (API) since 1948. Various companies from throughout the country obtain samples from retail outlets, analyze the samples by the American Society for Testing and Materials (ASTM) procedures, and report data to the Bartlesville center for compilation, tabulation, calculation, analysis and publication. A typical motor gasoline report covers 2400 samples from service stations throughout the country representing some 48 companies that manufacture and supply gasoline. The reports include trend charts, octane plots, and tables of test results from about a dozen different tests. From these data in 77 semiannual surveys, a summary report has thus been assembled that shows trends in motor gasolines throughout the entire era of winter 1942 to 1943 to the present. Trends of physical properties including octane numbers, antiknock ratings, distillation temperatures, Reid vapor pressure, sulfur and lead content are tabulated, plotted and discussed in the current report. Also included are trend effects of technological advances and the interactions of engine design, societal and political events and prices upon motor gasoline evolution during the 40 year period.

  12. Stellar chemical abundances: in pursuit of the highest achievable precision

    SciTech Connect (OSTI)

    Bedell, Megan; Bean, Jacob L.; Meléndez, Jorge; Leite, Paulo; Asplund, Martin

    2014-11-01

    The achievable level of precision on photospheric abundances of stars is a major limiting factor on investigations of exoplanet host star characteristics, the chemical histories of star clusters, and the evolution of the Milky Way and other galaxies. While model-induced errors can be minimized through the differential analysis of spectrally similar stars, the maximum achievable precision of this technique has been debated. As a test, we derive differential abundances of 19 elements from high-quality asteroid-reflected solar spectra taken using a variety of instruments and conditions. We treat the solar spectra as being from unknown stars and use the resulting differential abundances, which are expected to be zero, as a diagnostic of the error in our measurements. Our results indicate that the relative resolution of the target and reference spectra is a major consideration, with use of different instruments to obtain the two spectra leading to errors up to 0.04 dex. Use of the same instrument at different epochs for the two spectra has a much smaller effect (∼0.007 dex). The asteroid used to obtain the solar standard also has a negligible effect (∼0.006 dex). Assuming that systematic errors from the stellar model atmospheres have been minimized, as in the case of solar twins, we confirm that differential chemical abundances can be obtained at sub-0.01 dex precision with due care in the observations, data reduction, and abundance analysis.

  13. 18 Sco: A solar twin rich in refractory and neutron-capture elements. Implications for chemical tagging

    SciTech Connect (OSTI)

    Meléndez, Jorge; Monroe, TalaWanda R.; Tucci Maia, Marcelo; Freitas, Fabrício C.; Karakas, Amanda I.; Yong, David; Asplund, Martin; Bedell, Megan; Bean, Jacob; Bergemann, Maria; Do Nascimento, José-Dias Jr.; Castro, Matthieu; Bazot, Michael; Alves-Brito, Alan

    2014-08-10

    We study with unprecedented detail the chemical composition and stellar parameters of the solar twin 18 Sco in a strictly differential sense relative to the Sun. Our study is mainly based on high-resolution (R ∼ 110,000), high signal-to-noise ratio (800-1,000) Very Large Telescope UVES spectra, which allow us to achieve a precision of about 0.005 dex in differential abundances. The effective temperature and surface gravity of 18 Sco are T{sub eff} = 5823 ± 6 K and log g = 4.45 ± 0.02 dex, i.e., 18 Sco is 46 ± 6 K hotter than the Sun and log g is 0.01 ± 0.02 dex higher. Its metallicity is [Fe/H] = 0.054 ± 0.005 dex, and its microturbulence velocity is +0.02 ± 0.01 km s{sup –1} higher than solar. Our precise stellar parameters and differential isochrone analysis show that 18 Sco has a mass of 1.04 ± 0.02 M{sub ☉} and that it is ∼1.6 Gyr younger than the Sun. We use precise High Accuracy Radial velocity Planet Searcher (HARPS) radial velocities to search for planets, but none are detected. The chemical abundance pattern of 18 Sco displays a clear trend with condensation temperature, thus showing higher abundances of refractories in 18 Sco than in the Sun. Intriguingly, there are enhancements in the neutron-capture elements relative to the Sun. Despite the small element-to-element abundance differences among nearby n-capture elements (∼0.02 dex), we successfully reproduce the r-process pattern in the Solar System. This is independent evidence for the universality of the r process. Our results have important implications for chemical tagging in our Galaxy and nucleosynthesis in general.

  14. CONTRACTNO.: DE-X13-96GJ87335 TASK ORDER NO.: h

    Office of Legacy Management (LM)

    ... M. Widdop, MACTEC-ERS LSHP 7.3 (A. Garcia) cc WO: Contract File (J. Dearborn) Wind Direction (ESE) above ground surface; analyzed quart Sand and Gravel (90 day) exposure ...

  15. Motor gasolines, summer 1983

    SciTech Connect (OSTI)

    Shelton, E.M.

    1984-02-01

    The samples were collected from service stations throughout the country and were analyzed in the laboratories of various refiners, motor manufacturers, chemical companies, and research institutes. The analytical data for 1583 samples of motor gasoline, were submitted to the National Institute for Petroleum and Energy Research, Bartlesville, Oklahoma for study, necessary calculations, and compilation under a cooperative agreement between the National Institute for Petroleum and Energy Research (NIPER) and the American Petroleum Institute (API). They represent the products of 48 companies, large and small, which manufacture and supply gasoline. These data are tabulated by groups according to brands (unlabeled) and grades for 17 marketing districts into which the country is divided. A map included in this report, shows marketing areas, districts and sampling locations. The report also includes charts indicating the trends of selected properties of motor fuels since 1959. Sixteen octane distribution percent charts for areas 1, 2, 3, and 4 for unleaded antiknock index (R+M)/2 below 90.0, unleaded antiknock index (R+M)/2 90.0 and above, and leaded antiknock index (R+M)/2 below 93.0 grades of gasoline are presented in this report. The antiknock (octane) index (R+M)/2 averages of gasoline sold in this country were 87.5 for unleaded below 90.0, 91.4 for unleaded 90.0 and above, and 89.0 for leaded below 93.0 grades of gasoline. 16 figures, 5 tables.

  16. On the lithium dip in the metal poor open cluster NGC 2243

    SciTech Connect (OSTI)

    Franois, P. [GEPI, Paris-Meudon Observatory, 61 Avenue de l'Observatoire, F-75014 Paris (France); Pasquini, L.; Palsa, R. [ESO, European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching bei Mnchen (Germany); Biazzo, K. [INAF, Capodimonte Astronomical Observatory, via Moiariello 16, 80131 Naples (Italy); Bonifacio, P. [GEPI, Paris-Meudon Observatory, Place Jules Janssen 92190, Meudon (France)

    2014-05-02

    Lithium is a key element for studying the mixing mechanisms operating in stellar interiors. It can also be used to probe the chemical evolution of the Galaxy and the Big Bang nucleosynthesis. Measuring the abundance of Lithium in stars belonging to Open Clusters (hereafter OC) allows a detailed comparison with stellar evolutionary models. NGC 2243 is particularly interesting thanks to its relative low metallicity ([Fe/H]=?0.54 0.10 dex). We performed a detailed analysis of high-resolution spectra obtained with the multi-object facility FLAMES at the VLT 8.2m telescope. Lithium abundance has been measured in 27 stars. We found a Li dip center of 1.06 M{sub ?}, which is significantly smaller than that observed in solar metallicity and metal-rich clusters. This finding confirms and strengthens the conclusion that the mass of the stars in the Li dip strongly depends on stellar metallicity. The mean Li abundance of the cluster is log n(Li) = 2.70 dex, which is substantially higher than that observed in 47 Tue. We derived an iron abundance of [Fe/H]=?0.540.10 dex for NGC 2243, in agreement (within the errors) with previous findings.

  17. Method of preparing metallocene compounds

    DOE Patents [OSTI]

    Rosenblum, Myron; Matchett, Stephen A.

    1992-01-01

    This invention describes a novel method of preparing metallocene compounds. The invention is based on synthesis of novel bis cyclopentadienides that, under appropriate conditions, will either encapsulate a transition metal to produce a metallocene such as ferrocene, or ferrocene derivative, or will yield a polymeric metallocene. Compounds produced by this process are useful as catalysts in propulsion systems, or as anti-knock compounds in gasolines.

  18. ELEMENTAL ABUNDANCE DIFFERENCES IN THE 16 CYGNI BINARY SYSTEM: A SIGNATURE OF GAS GIANT PLANET FORMATION?

    SciTech Connect (OSTI)

    RamIrez, I.; Roederer, I. U.; Fish, J. R.; Melendez, J.

    2011-10-20

    The atmospheric parameters of the components of the 16 Cygni binary system, in which the secondary has a gas giant planet detected, are measured accurately using high-quality observational data. Abundances relative to solar are obtained for 25 elements with a mean error of {sigma}([X/H]) = 0.023 dex. The fact that 16 Cyg A has about four times more lithium than 16 Cyg B is normal considering the slightly different masses of the stars. The abundance patterns of 16 Cyg A and B, relative to iron, are typical of that observed in most of the so-called solar twin stars, with the exception of the heavy elements (Z > 30), which can, however, be explained by Galactic chemical evolution. Differential (A-B) abundances are measured with even higher precision ({sigma}({Delta}[X/H]) = 0.018 dex, on average). We find that 16 Cyg A is more metal-rich than 16 Cyg B by {Delta}[M/H] = +0.041 {+-} 0.007 dex. On an element-to-element basis, no correlation between the A-B abundance differences and dust condensation temperature (T{sub C}) is detected. Based on these results, we conclude that if the process of planet formation around 16 Cyg B is responsible for the observed abundance pattern, the formation of gas giants produces a constant downward shift in the photospheric abundance of metals, without a T{sub C} correlation. The latter would be produced by the formation of terrestrial planets instead, as suggested by other recent works on precise elemental abundances. Nevertheless, a scenario consistent with these observations requires the convective envelopes of {approx_equal} 1 M{sub sun} stars to reach their present-day sizes about three times quicker than predicted by standard stellar evolution models.

  19. THE RELATION BETWEEN STAR FORMATION RATE AND STELLAR MASS FOR GALAXIES AT 3.5 ? z ? 6.5 IN CANDELS

    SciTech Connect (OSTI)

    Salmon, Brett; Papovich, Casey; Tilvi, Vithal; Finkelstein, Steven L.; Finlator, Kristian; Behroozi, Peter; Lu, Yu; Wechsler, Risa H.; Dahlen, Tomas; Ferguson, Henry C.; Dav, Romeel; Dekel, Avishai; Dickinson, Mark; Giavalisco, Mauro; Long, James; Mobasher, Bahram; Reddy, Naveen; Somerville, Rachel S.

    2015-02-01

    Distant star-forming galaxies show a correlation between their star formation rates (SFRs) and stellar masses, and this has deep implications for galaxy formation. Here, we present a study on the evolution of the slope and scatter of the SFR-stellar mass relation for galaxies at 3.5 ? z ? 6.5 using multi-wavelength photometry in GOODS-S from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) and Spitzer Extended Deep Survey. We describe an updated, Bayesian spectral-energy distribution fitting method that incorporates effects of nebular line emission, star formation histories that are constant or rising with time, and different dust-attenuation prescriptions (starburst and Small Magellanic Cloud). From z = 6.5 to z = 3.5 star-forming galaxies in CANDELS follow a nearly unevolving correlation between stellar mass and SFR that follows SFR?M{sub ?}{sup a} with a =0.54 0.16 at z ? 6 and 0.70 0.21 at z ? 4. This evolution requires a star formation history that increases with decreasing redshift (on average, the SFRs of individual galaxies rise with time). The observed scatter in the SFR-stellar mass relation is tight, ?(log SFR/M {sub ?} yr{sup 1}) < 0.3-0.4dex, for galaxies with log M {sub *}/M {sub ?} > 9dex. Assuming that the SFR is tied to the net gas inflow rate (SFR? M-dot {sub gas}), then the scatter in the gas inflow rate is also smaller than 0.30.4dex for star-forming galaxies in these stellar mass and redshift ranges, at least when averaged over the timescale of star formation. We further show that the implied star formation history of objects selected on the basis of their co-moving number densities is consistent with the evolution in the SFR-stellar mass relation.

  20. SODIUM AND OXYGEN ABUNDANCES IN THE OPEN CLUSTER NGC6791 FROM APOGEE H-BAND SPECTROSCOPY

    SciTech Connect (OSTI)

    Cunha, Katia; Souto, Diogo; Smith, Verne V.; Johnson, Jennifer A.; Bergemann, Maria; Mszros, Szabolcs; Shetrone, Matthew D.; Prieto, Carlos Allende; Schiavon, Ricardo P.; Frinchaboy, Peter; Zasowski, Gail; Bizyaev, Dmitry; Holtzman, Jon; Garca Prez, Ana E.; Majewski, Steven R.; Nidever, David; Beers, Timothy; Carrera, Ricardo; Geisler, Doug; Gunn, James; and others

    2015-01-10

    The open cluster NGC6791 is among the oldest, most massive, and metal-rich open clusters in the Galaxy. High-resolution H-band spectra from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) of 11 red giants in NGC6791 are analyzed for their chemical abundances of iron, oxygen, and sodium. The abundances of these three elements are found to be homogeneous (with abundance dispersions at the level of ?0.05-0.07 dex) in these cluster red giants, which span much of the red-giant branch (T {sub eff} ? 3500-4600K), and include two red clump giants. From the infrared spectra, this cluster is confirmed to be among the most metal-rich clusters in the Galaxy (([Fe/H]) = 0.34 0.06) and is found to have a roughly solar value of [O/Fe] and slightly enhanced [Na/Fe]. Our non-LTE calculations for the studied Na I lines in the APOGEE spectral region (16373.86 and 16388.85 ) indicate only small departures from LTE (?0.04 dex) for the parameter range and metallicity of the studied stars. The previously reported double population of cluster members with different Na abundances is not found among the studied sample.

  1. REVISITING THE COSMIC STAR FORMATION HISTORY: CAUTION ON THE UNCERTAINTIES IN DUST CORRECTION AND STAR FORMATION RATE CONVERSION

    SciTech Connect (OSTI)

    Kobayashi, Masakazu A. R.; Inoue, Yoshiyuki; Inoue, Akio K.

    2013-01-20

    The cosmic star formation rate density (CSFRD) has been observationally investigated out to redshift z {approx_equal} 10. However, most of the theoretical models for galaxy formation underpredict the CSFRD at z {approx}> 1. Since the theoretical models reproduce the observed luminosity functions (LFs), luminosity densities (LDs), and stellar mass density at each redshift, this inconsistency does not simply imply that theoretical models should incorporate some missing unknown physical processes in galaxy formation. Here, we examine the cause of this inconsistency at UV wavelengths by using a mock catalog of galaxies generated by a semi-analytic model of galaxy formation. We find that this inconsistency is due to two observational uncertainties: the dust obscuration correction and the conversion from UV luminosity to star formation rate (SFR). The methods for correction of obscuration and SFR conversion used in observational studies result in the overestimation of the CSFRD by {approx}0.1-0.3 dex and {approx}0.1-0.2 dex, respectively, compared to the results obtained directly from our mock catalog. We present new empirical calibrations for dust attenuation and conversion from observed UV LFs and LDs into the CSFRD.

  2. NON-LOCAL THERMODYNAMICAL EQUILIBRIUM EFFECTS ON THE IRON ABUNDANCE OF ASYMPTOTIC GIANT BRANCH STARS IN 47 TUCANAE

    SciTech Connect (OSTI)

    Lapenna, E.; Mucciarelli, A.; Lanzoni, B.; Ferraro, F. R.; Dalessandro, E.; Massari, D.

    2014-12-20

    We present the iron abundance of 24 asymptotic giant branch (AGB) stars, members of the globular cluster 47 Tucanae, obtained with high-resolution spectra collected with the FEROS spectrograph at the MPG/ESO 2.2 m Telescope. We find that the iron abundances derived from neutral lines (with a mean value [Fe I/H]=0.94 0.01, ? = 0.08 dex) are systematically lower than those derived from single ionized lines ([Fe II/H] =0.83 0.01, ? = 0.05 dex). Only the latter are in agreement with those obtained for a sample of red giant branch (RGB) cluster stars, for which the Fe I and Fe II lines provide the same iron abundance. This finding suggests that non-local thermodynamical equilibrium (NLTE) effects driven by overionization mechanisms are present in the atmosphere of AGB stars and significantly affect the Fe I lines while leaving Fe II features unaltered. On the other hand, the very good ionization equilibrium found for RGB stars indicates that these NLTE effects may depend on the evolutionary stage. We discuss the impact of this finding on both the chemical analysis of AGB stars and on the search for evolved blue stragglers.

  3. Hemocompatibility and biocompatibility of antibacterial biomimetic hybrid films

    SciTech Connect (OSTI)

    Coll Ferrer, M. Carme; Eckmann, Uriel N.; Composto, Russell J.; Eckmann, David M.

    2013-11-01

    In previous work, we developed novel antibacterial hybrid coatings based on dextran containing dispersed Ag NPs (? 5 nm, DEX-Ag) aimed to offer dual protection against two of the most common complications associated with implant surgery, infections and rejection of the implant. However, their blood-material interactions are unknown. In this study, we assess the hemocompatibility and biocompatibility of DEX-Ag using fresh blood and two cell lines of the immune system, monocytes (THP-1 cells) and macrophages (PMA-stimulated THP-1 cells). Glass, polyurethane (PU) and bare dextran (DEX) were used as reference surfaces. PU, DEX and DEX-Ag exhibited non-hemolytic properties. Relative to glass (100%), platelet attachment on PU, DEX and DEX-Ag was 15%, 10% and 34%, respectively. Further, we assessed cell morphology and viability, pro-inflammatory cytokines expression (TNF-? and IL-1?), pro-inflammatory eicosanoid expression (Prostaglandin E{sub 2}, PGE{sub 2}) and release of reactive oxygen species (ROS, superoxide and H{sub 2}O{sub 2}) following incubation of the cells with the surfaces. The morphology and cell viability of THP-1 cells were not affected by DEX-Ag whereas DEX-Ag minimized spreading of PMA-stimulated THP-1 cells and caused a reduction in cell viability (16% relative to other surfaces). Although DEX-Ag slightly enhanced release of ROS, the expression of pro-inflammatory cytokines remained minimal with similar levels of PGE{sub 2}, as compared to the other surfaces studied. These results highlight low toxicity of DEX-Ag and hold promise for future applications in vivo. - Highlights: We examined specific blood-contact reactions of dextran doped with Ag NPs coatings. Biocompatibility was assessed with THP-1 cells and PMA-stimulated THP-1 cells. Glass, polyurethane and dextran were used as reference surfaces. Hybrid coatings exhibited non-hemolytic properties. Low toxicity, inflammatory response and ROS suggest potential for in vivo use.

  4. MAGNESIUM ISOTOPE RATIOS IN {omega} CENTAURI RED GIANTS

    SciTech Connect (OSTI)

    Da Costa, G. S.; Norris, John E.; Yong, David

    2013-05-20

    We have used the high-resolution observations obtained at the Anglo-Australian Telescope with Ultra-High Resolution Facility (R {approx} 100,000) and at Gemini-S with b-HROS (R {approx} 150,000) to determine magnesium isotope ratios for seven {omega} Cen red giants that cover a range in iron abundance from [Fe/H] = -1.78 to -0.78 dex, and for two red giants in M4 (NGC 6121). The {omega} Cen stars sample both the ''primordial'' (i.e., O-rich, Na- and Al-poor) and the ''extreme'' (O-depleted, Na- and Al-rich) populations in the cluster. The primordial population stars in both {omega} Cen and M4 show ({sup 25}Mg, {sup 26}Mg)/{sup 24}Mg isotopic ratios that are consistent with those found for the primordial population in other globular clusters with similar [Fe/H] values. The isotopic ratios for the {omega} Cen extreme stars are also consistent with those for extreme population stars in other clusters. The results for the extreme population stars studied indicate that the {sup 26}Mg/{sup 24}Mg ratio is highest at intermediate metallicities ([Fe/H] < -1.4 dex), and for the highest [Al/Fe] values. Further, the relative abundance of {sup 26}Mg in the extreme population stars is notably higher than that of {sup 25}Mg, in contrast to model predictions. The {sup 25}Mg/{sup 24}Mg isotopic ratio in fact does not show any obvious dependence on either [Fe/H] or [Al/Fe] nor, intriguingly, any obvious difference between the primordial and extreme population stars.

  5. Detailed abundances of planet-hosting wide binaries. I. Did planet formation imprint chemical signatures in the atmospheres of HD 20782/81?

    SciTech Connect (OSTI)

    Mack III, Claude E.; Stassun, Keivan G.; Schuler, Simon C.; Norris, John

    2014-06-01

    Using high-resolution, high signal-to-noise echelle spectra obtained with Magellan/MIKE, we present a detailed chemical abundance analysis of both stars in the planet-hosting wide binary system HD 20782 + HD 20781. Both stars are G dwarfs, and presumably coeval, forming in the same molecular cloud. Therefore we expect that they should possess the same bulk metallicities. Furthermore, both stars also host giant planets on eccentric orbits with pericenters ≲0.2 AU. Here, we investigate if planets with such orbits could lead to the host stars ingesting material, which in turn may leave similar chemical imprints in their atmospheric abundances. We derived abundances of 15 elements spanning a range of condensation temperature, T {sub C} ≈ 40-1660 K. The two stars are found to have a mean element-to-element abundance difference of 0.04 ± 0.07 dex, which is consistent with both stars having identical bulk metallicities. In addition, for both stars, the refractory elements (T {sub C} >900 K) exhibit a positive correlation between abundance (relative to solar) and T {sub C}, with similar slopes of ≈1×10{sup –4} dex K{sup –1}. The measured positive correlations are not perfect; both stars exhibit a scatter of ≈5×10{sup –5} dex K{sup –1} about the mean trend, and certain elements (Na, Al, Sc) are similarly deviant in both stars. These findings are discussed in the context of models for giant planet migration that predict the accretion of H-depleted rocky material by the host star. We show that a simple simulation of a solar-type star accreting material with Earth-like composition predicts a positive—but imperfect—correlation between refractory elemental abundances and T {sub C}. Our measured slopes are consistent with what is predicted for the ingestion of 10-20 Earths by each star in the system. In addition, the specific element-by-element scatter might be used to distinguish between planetary accretion and Galactic chemical evolution scenarios.

  6. A LARGE C+N+O ABUNDANCE SPREAD IN GIANT STARS OF THE GLOBULAR CLUSTER NGC 1851

    SciTech Connect (OSTI)

    Yong, David; Karakas, Amanda I.; Norris, John E.; Grundahl, Frank; D'Antona, Francesca; Lattanzio, John C. E-mail: akarakas@mso.anu.edu.au E-mail: fgj@phys.au.dk E-mail: John.Lattanzio@sci.monash.edu.au

    2009-04-10

    Abundances of C, N, and O are determined in four bright red giants that span the known abundance range for light (Na and Al) and s-process (Zr and La) elements in the globular cluster NGC 1851. The abundance sum C+N+O exhibits a range of 0.6 dex, a factor of 4, in contrast to other clusters in which no significant C+N+O spread is found. Such an abundance range offers support for the Cassisi et al. scenario in which the double subgiant branch populations are coeval but with different mixtures of C+N+O abundances. Further, the Na, Al, Zr, and La abundances are correlated with C+N+O, and therefore NGC 1851 is the first cluster to provide strong support for the scenario in which asymptotic giant branch stars are responsible for the globular cluster light element abundance variations.

  7. THE APOKASC CATALOG: AN ASTEROSEISMIC AND SPECTROSCOPIC JOINT SURVEY OF TARGETS IN THE KEPLER FIELDS

    SciTech Connect (OSTI)

    Pinsonneault, Marc H.; Epstein, Courtney; Johnson, Jennifer A.; Elsworth, Yvonne; Chaplin, William J.; Hekker, Saskia; Silva Aguirre, Victor; Stello, Dennis; Mszros, Sz.; Garca, Rafael A.; Beck, Paul; Mathur, Savita; Garca Prez, Ana; Girardi, Lo; Basu, Sarbani; Shetrone, Matthew; Allende Prieto, Carlos; Beers, Timothy C.; and others

    2015-01-01

    We present the first APOKASC catalog of spectroscopic and asteroseismic properties of 1916 red giants observed in the Kepler fields. The spectroscopic parameters provided from the Apache Point Observatory Galactic Evolution Experiment project are complemented with asteroseismic surface gravities, masses, radii, and mean densities determined by members of the Kepler Asteroseismology Science Consortium. We assess both random and systematic sources of error and include a discussion of sample selection for giants in the Kepler fields. Total uncertainties in the main catalog properties are of the order of 80K in T {sub eff}, 0.06 dex in [M/H], 0.014 dex in log g, and 12% and 5% in mass and radius, respectively; these reflect a combination of systematic and random errors. Asteroseismic surface gravities are substantially more precise and accurate than spectroscopic ones, and we find good agreement between their mean values and the calibrated spectroscopic surface gravities. There are, however, systematic underlying trends with T {sub eff} and log g. Our effective temperature scale is between 0 and 200K cooler than that expected from the infrared flux method, depending on the adopted extinction map, which provides evidence for a lower value on average than that inferred for the Kepler Input Catalog (KIC). We find a reasonable correspondence between the photometric KIC and spectroscopic APOKASC metallicity scales, with increased dispersion in KIC metallicities as the absolute metal abundance decreases, and offsets in T {sub eff} and log g consistent with those derived in the literature. We present mean fitting relations between APOKASC and KIC observables and discuss future prospects, strengths, and limitations of the catalog data.

  8. TRACING THE OUTER HALO IN A GIANT ELLIPTICAL TO 25 R {sub eff}

    SciTech Connect (OSTI)

    Rejkuba, M.; Harris, W. E.; Greggio, L.; Harris, G. L. H.; Jerjen, H.; Gonzalez, O. A.

    2014-08-10

    We have used the Advanced Camera for Surveys and Wide Field Camera 3 cameras on board the Hubble Space Telescope to resolve stars in the halo of the nearest giant elliptical (gE) galaxy NGC 5128 out to a projected distance of 140 kpc (25 effective radii, R {sub eff}) along the major axis and 90 kpc (16 R {sub eff}) along the minor axis. This data set provides an unprecedented radial coverage of the stellar halo properties in any gE galaxy. Color-magnitude diagrams clearly reveal the presence of the red giant branch stars belonging to the halo of NGC 5128, even in our most distant fields. The star counts demonstrate increasing flattening of the outer halo, which is elongated along the major axis of the galaxy. The V – I colors of the red giants enable us to measure the metallicity distribution in each field and so map the gradient out to ∼16 R {sub eff} from the galaxy center along the major axis. A median metallicity is obtained even for the outermost fields along both axes. We observe a smooth transition from a metal-rich ([M/H] ∼0.0) inner galaxy to lower metallicity in the outer halo, with the metallicity gradient slope along the major axis of Δ[M/H]/ΔR ≅ –0.0054 ± 0.0006 dex kpc{sup –1}. In the outer halo, beyond ∼10 R {sub eff}, the number density profile follows a power law, but also significant field-to-field metallicity and star count variations are detected. The metal-rich component dominates in all observed fields, and the median metallicity is [M/H] >–1 dex in all fields.

  9. ELEMENTAL ABUNDANCE RATIOS IN STARS OF THE OUTER GALACTIC DISK. IV. A NEW SAMPLE OF OPEN CLUSTERS

    SciTech Connect (OSTI)

    Yong, David; Carney, Bruce W.; Friel, Eileen D. E-mail: bruce@physics.unc.edu

    2012-10-01

    We present radial velocities and chemical abundances for nine stars in the old, distant open clusters Be18, Be21, Be22, Be32, and PWM4. For Be18 and PWM4, these are the first chemical abundance measurements. Combining our data with literature results produces a compilation of some 68 chemical abundance measurements in 49 unique clusters. For this combined sample, we study the chemical abundances of open clusters as a function of distance, age, and metallicity. We confirm that the metallicity gradient in the outer disk is flatter than the gradient in the vicinity of the solar neighborhood. We also confirm that the open clusters in the outer disk are metal-poor with enhancements in the ratios [{alpha}/Fe] and perhaps [Eu/Fe]. All elements show negligible or small trends between [X/Fe] and distance (<0.02 dex kpc{sup -1}), but for some elements, there is a hint that the local (R{sub GC} < 13 kpc) and distant (R{sub GC} > 13 kpc) samples may have different trends with distance. There is no evidence for significant abundance trends versus age (<0.04 dex Gyr{sup -1}). We measure the linear relation between [X/Fe] and metallicity, [Fe/H], and find that the scatter about the mean trend is comparable to the measurement uncertainties. Comparison with solar neighborhood field giants shows that the open clusters share similar abundance ratios [X/Fe] at a given metallicity. While the flattening of the metallicity gradient and enhanced [{alpha}/Fe] ratios in the outer disk suggest a chemical enrichment history different from that of the solar neighborhood, we echo the sentiments expressed by Friel et al. that definitive conclusions await homogeneous analyses of larger samples of stars in larger numbers of clusters. Arguably, our understanding of the evolution of the outer disk from open clusters is currently limited by systematic abundance differences between various studies.

  10. Stellar kinematics and metallicities in the ultra-faint dwarf galaxy Reticulum II

    SciTech Connect (OSTI)

    Simon, J. D.

    2015-07-23

    With this study, we present Magellan/M2FS, Very Large Telescope/GIRAFFE, and Gemini South/GMOS spectroscopy of the newly discovered Milky Way satellite Reticulum II. Based on the spectra of 25 Ret II member stars selected from Dark Energy Survey imaging, we measure a mean heliocentric velocity of $62.8\\pm 0.5\\;\\mathrm{km}\\;{{\\rm{s}}}^{-1}$ and a velocity dispersion of $3.3\\pm 0.7\\;\\mathrm{km}\\;{{\\rm{s}}}^{-1}$. The mass-to-light ratio of Ret II within its half-light radius is $470\\pm 210\\ {M}_{\\odot }/{L}_{\\odot }$, demonstrating that it is a strongly dark matter-dominated system. Despite its spatial proximity to the Magellanic Clouds, the radial velocity of Ret II differs from that of the LMC and SMC by 199 and 83 $\\mathrm{km}\\ {{\\rm{s}}}^{-1}$, respectively, suggesting that it is not gravitationally bound to the Magellanic system. The likely member stars of Ret II span 1.3 dex in metallicity, with a dispersion of 0.28 0.09 dex, and we identify several extremely metal-poor stars with ${\\rm{[Fe/H]}}\\lt -3$. In combination with its luminosity, size, and ellipticity, these results confirm that Ret II is an ultra-faint dwarf galaxy. With a mean metallicity of ${\\rm{[Fe/H]}}=-2.65\\pm 0.07$, Ret II matches Segue 1 as the most metal-poor galaxy known. Although Ret II is the third-closest dwarf galaxy to the Milky Way, the line-of-sight integral of the dark matter density squared is ${\\mathrm{log}}_{10}(J)=18.8\\pm 0.6\\;\\;\\mathrm{GeV}{\\;}^{2}\\;{\\mathrm{cm}}^{-5}\\;$ within 0fdg2, indicating that the predicted gamma-ray flux from dark matter annihilation in Ret II is lower than that of several other dwarf galaxies.

  11. METAL ABUNDANCES, RADIAL VELOCITIES, AND OTHER PHYSICAL CHARACTERISTICS FOR THE RR LYRAE STARS IN THE KEPLER FIELD

    SciTech Connect (OSTI)

    Nemec, James M.; Cohen, Judith G.; Sesar, Branimir; Ripepi, Vincenzo; Derekas, Aliz; Moskalik, Pawel; Chadid, Merieme; Bruntt, Hans E-mail: jmn@isr.bc.ca E-mail: bsesar@astro.caltech.edu E-mail: derekas@konkoly.hu E-mail: chadid@marseille.fr

    2013-08-20

    Spectroscopic iron-to-hydrogen ratios, radial velocities, atmospheric parameters, and new photometric analyses are presented for 41 RR Lyrae stars (and one probable high-amplitude {delta} Sct star) located in the field-of-view of the Kepler space telescope. Thirty-seven of the RR Lyrae stars are fundamental-mode pulsators (i.e., RRab stars) of which sixteen exhibit the Blazhko effect. Four of the stars are multiperiodic RRc pulsators oscillating primarily in the first-overtone mode. Spectroscopic [Fe/H] values for the 34 stars for which we were able to derive estimates range from -2.54 {+-} 0.13 (NR Lyr) to -0.05 {+-} 0.13 dex (V784 Cyg), and for the 19 Kepler-field non-Blazhko stars studied by Nemec et al. the abundances agree will with their photometric [Fe/H] values. Four non-Blazhko RR Lyrae stars that they identified as metal-rich (KIC 6100702, V2470 Cyg, V782 Cyg and V784 Cyg) are confirmed as such, and four additional stars (V839 Cyg, KIC 5520878, KIC 8832417, KIC 3868420) are also shown here to be metal-rich. Five of the non-Blazhko RRab stars are found to be more metal-rich than [Fe/H] {approx}-0.9 dex while all of the 16 Blazhko stars are more metal-poor than this value. New P-{phi}{sub 31}{sup s}-[Fe/H] relationships are derived based on {approx}970 days of quasi-continuous high-precision Q0-Q11 long- and short-cadence Kepler photometry. With the exception of some Blazhko stars, the spectroscopic and photometric [Fe/H] values are in good agreement. Several stars with unique photometric characteristics are identified, including a Blazhko variable with the smallest known amplitude and frequency modulations (V838 Cyg)

  12. A historical analysis of the co-evolution of gasoline octane number and spark-ignition engines

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Splitter, Derek A.; Pawlowski, Alex E.; Wagner, Robert M.

    2016-01-06

    In our work, the authors reviewed engine, vehicle, and fuel data since 1925 to examine the historical and recent coupling of compression ratio and fuel antiknock properties (i.e., octane number) in the U.S. light-duty vehicle market. The analysis identified historical timeframes, trends, and illustrated how three factors: consumer preferences, technical capabilities, and regulatory legislation, affect personal mobility. Data showed that throughout history these three factors have a complex and time sensitive interplay. Long term trends in the data were identified where interaction and evolution between all three factors was observed. Transportation efficiency per unit power (gal/ton-mi/hp) was found to bemore » a good metric to integrate technical, societal, and regulatory effects into the evolutional pathway of personal mobility. From this framework, discussions of future evolutionary changes to personal mobility are also presented.« less

  13. Separation and concentration of lower alcohols from dilute aqueous solutions

    DOE Patents [OSTI]

    Moore, Raymond H.; Eakin, David E.; Baker, Eddie G.; Hallen, Richard T.

    1991-01-01

    A process for producing, from a dilute aqueous solution of a lower (C.sub.1 -C.sub.5) alcohol, a concentrated liquid solution of the alcohol in an aromatic organic solvent is disclosed. Most of the water is removed from the dilute aqueous solution of alcohol by chilling sufficiently to form ice crystals. Simultaneously, the remaining liquid is extracted at substantially the same low temperature with a liquid organic solvent that is substantially immiscible in aqueous liquids and has an affinity for the alcohol at that temperature, causing the alcohol to transfer to the organic phase. After separating the organic liquid from the ice crystals, the organic liquid can be distilled to enrich the concentration of alcohol therein. Ethanol so separated from water and concentrated in an organic solvent such as toluene is useful as an anti-knock additive for gasoline.

  14. Alkaline tolerant dextranase from streptomyces anulatus

    DOE Patents [OSTI]

    Decker, Stephen R. (Berthoud, CO); Adney, William S. (Golden, CO); Vinzant, Todd B. (Golden, CO); Himmel, Michael E. (Littleton, CO)

    2003-01-01

    A process for production of an alkaline tolerant dextranase enzyme comprises culturing a dextran-producing microorganism Streptomyces anulatus having accession no. ATCC PTA-3866 to produce an alkaline tolerant dextranase, Dex 1 wherein the protein in said enzyme is characterized by a MW of 63.3 kDa and Dex 2 wherein its protein is characterized by a MW of 81.8 kDa.

  15. Motor gasolines, summer 1985

    SciTech Connect (OSTI)

    Dickson, C.L.; Woodward, P.W.

    1986-06-01

    Samples for this report were collected from service stations throughout the country and were analyzed in laboratories of various refiners, motor manufacturers, chemical companies, and research institutes. Analytical data for the 1571 motor gasoline and 206 motor gasoline/alcohol blend samples were submitted to the National Institute for Petroleum and Energy Research (NIPER), Bartlesville, Oklahoma, for reporting. This work is jointly funded by the American Petroleum Institute (API) and the United States Department of Energy (DOE), Bartlesville Project Office (DOE cooperative agreement No. FC22-83FE60149). The data are representative of the products of 62 marketers, large and small, which manufacture and supply gasoline. They are tabulated by groups according to brands (unlabeled) and grades for 17 marketing districts into which the country is divided. A map shows the marketing areas, districts, and sampling locations. The report includes trend charts of selected properties of motor fuels over the last twenty-five years. Twelve octane distribution graphs for leaded and unleaded grades of gasoline are presented for areas 1, 2, 3, and 4. The average antiknock (octane) index (R + M)/2 of gasoline sold in the United States during June, July, and August 1985 was 87.4 for unleaded below 90.0, 91.7 for unleaded 90.0 and above, and 88.8 for leaded below 93.0 grades of gasoline. Analyses of motor gasoline containing various alcohols are reported in separate tables beginning with this report. The average antiknock (octane) index (R + M)/2 of gasoline containing alcohols was 88.6 for unleaded below 90.0, 91.4 for unleaded 90.0 and above, and 90.2 for leaded below 93.0 grades of gasoline. 16 figs., 8 tabs.

  16. Header Sheet Doc ID Z OAK RIDGE NATIONAL LABORATORY M. E. Murray

    Office of Legacy Management (LM)

    INTERNET: r'0 March 31, 1997 Mr. Andrew Meloy DuPont Environmental Remediation Services DuPont Chambers Works Route 130, Anti-Knocks Building G Deepwater, New Jersey 08023 Dear Mr. ...

  17. Stellar kinematics and metallicities in the ultra-faint dwarf galaxy Reticulum II

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Simon, J. D.

    2015-07-23

    With this study, we present Magellan/M2FS, Very Large Telescope/GIRAFFE, and Gemini South/GMOS spectroscopy of the newly discovered Milky Way satellite Reticulum II. Based on the spectra of 25 Ret II member stars selected from Dark Energy Survey imaging, we measure a mean heliocentric velocity ofmore » $$62.8\\pm 0.5\\;\\mathrm{km}\\;{{\\rm{s}}}^{-1}$$ and a velocity dispersion of $$3.3\\pm 0.7\\;\\mathrm{km}\\;{{\\rm{s}}}^{-1}$$. The mass-to-light ratio of Ret II within its half-light radius is $$470\\pm 210\\ {M}_{\\odot }/{L}_{\\odot }$$, demonstrating that it is a strongly dark matter-dominated system. Despite its spatial proximity to the Magellanic Clouds, the radial velocity of Ret II differs from that of the LMC and SMC by 199 and 83 $$\\mathrm{km}\\ {{\\rm{s}}}^{-1}$$, respectively, suggesting that it is not gravitationally bound to the Magellanic system. The likely member stars of Ret II span 1.3 dex in metallicity, with a dispersion of 0.28 ± 0.09 dex, and we identify several extremely metal-poor stars with $${\\rm{[Fe/H]}}\\lt -3$$. In combination with its luminosity, size, and ellipticity, these results confirm that Ret II is an ultra-faint dwarf galaxy. With a mean metallicity of $${\\rm{[Fe/H]}}=-2.65\\pm 0.07$$, Ret II matches Segue 1 as the most metal-poor galaxy known. Although Ret II is the third-closest dwarf galaxy to the Milky Way, the line-of-sight integral of the dark matter density squared is $${\\mathrm{log}}_{10}(J)=18.8\\pm 0.6\\;\\;\\mathrm{GeV}{\\;}^{2}\\;{\\mathrm{cm}}^{-5}\\;$$ within 0fdg2, indicating that the predicted gamma-ray flux from dark matter annihilation in Ret II is lower than that of several other dwarf galaxies.« less

  18. Supermassive black holes with high accretion rates in active galactic nuclei. II. The most luminous standard candles in the universe

    SciTech Connect (OSTI)

    Wang, Jian-Min; Du, Pu; Hu, Chen; Qiu, Jie; Li, Yan-Rong [Key Laboratory for Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, 19B Yuquan Road, Beijing 100049 (China); Netzer, Hagai; Kaspi, Shai [Wise Observatory, School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978 (Israel); Bai, Jin-Ming; Wang, Fang [Yunnan Observatory, Chinese Academy of Sciences, Kunming 650011, Yunnan (China); Lu, Kai-Xing [Astronomy Department, Beijing Normal University, Beijing 100875 (China); Collaboration: SEAMBH collaboration

    2014-10-01

    This is the second in a series of papers reporting on a large reverberation mapping (RM) campaign to measure black hole (BH) mass in high accretion rate active galactic nuclei (AGNs). The goal is to identify super-Eddington accreting massive black holes (SEAMBHs) and to use their unique properties to construct a new method for measuring cosmological distances. Based on theoretical models, the saturated bolometric luminosity of such sources is proportional to the BH mass, which can be used to obtain their distance. Here we report on five new RM measurements and show that in four of the cases, we can measure the BH mass and three of these sources are SEAMBHs. Together with the three sources from our earlier work, we now have six new sources of this type. We use a novel method based on a minimal radiation efficiency to identify nine additional SEAMBHs from earlier RM-based mass measurements. We use a Bayesian analysis to determine the parameters of the new distance expression and the method uncertainties from the observed properties of the objects in the sample. The ratio of the newly measured distances to the standard cosmological ones has a mean scatter of 0.14 dex, indicating that SEAMBHs can be use as cosmological distance probes. With their high luminosity, long period of activity, and large numbers at high redshifts, SEAMBHs have a potential to extend the cosmic distance ladder beyond the range now explored by Type Ia supernovae.

  19. Effects of magnetic fields on lithium evolution in F and G stars

    SciTech Connect (OSTI)

    Li, T. D.; Bi, S. L.; Yang, W. M.; Liu, K.; Tian, Z. J.; Ge, Z. S., E-mail: litanda@mail.bnu.edu.cn, E-mail: bisl@bnu.edu.cn [Astronomy Department, Beijing Normal University, Beijing 100875 (China)

    2014-02-01

    To study the effects of magnetic fields on lithium depletion and to explain the characteristics of lithium evolution in F- and G-type stars in open clusters, we construct a stellar model that includes a Tayler-Spruit dynamo-type field. Through examining the features of extra-mixing caused by magnetic fields in stellar interiors and the relationship between lithium depletion and the input parameters (i.e., mass, metallicity, and the initial rotational condition), we find that the magnetic model produces extra-mixing processes different from other models. During pre-main sequence, the model exhibits very efficient extra-mixing, resulting in strong lithium depletion. As a star evolves, the efficiency of extra-mixing rapidly decreases and lithium depletion slows down at old ages. By setting up different initial rotating conditions, the model predicts dispersions of lithium abundance in both main sequence and pre-main sequence stages. The dispersion begins when a radiative core forms in the interior. The number sees a rapid growth afterward, reaching 0.1-0.5 dex at zero age main sequence in G and late-F stars. The increase of dispersion continues in the main sequence, which is slight in G and late-F stars while significant in mid-F stars. Finally, a comparison is carried out between the theoretical results and the observed data in four open clusters. Good agreements are obtained.

  20. THREE DISCRETE GROUPS WITH HOMOGENEOUS CHEMISTRY ALONG THE RED GIANT BRANCH IN THE GLOBULAR CLUSTER NGC2808

    SciTech Connect (OSTI)

    Carretta, E.

    2014-11-10

    We present the homogeneous reanalysis of Mg and Al abundances from high resolution UVES/FLAMES spectra for 31 red giants in the globular cluster NGC2808. We found a well defined Mg-Al anticorrelation reaching a regime of subsolar Mg abundance ratios, with a spread of about 1.4dex in [Al/Fe]. The main result from the improved statistics of our sample is that the distribution of stars is not continuous along the anticorrelation because they are neatly clustered into three distinct clumps, each with different chemical compositions. One group (P) shows a primordial composition of field stars of similar metallicity, and the other two (I and E) have increasing abundances of Al and decreasing abundances of Mg. The fraction of stars we found in the three components (P: 68%, I: 19%, E: 13%) is in excellent agreement with the ratios computed for the three distinct main sequences in NGC2808: for the first time there is a clear correspondence between discrete photometric sequences of dwarfs and distinct groups of giants with homogeneous chemistry. The composition of the I group cannot be reproduced by mixing of matter with extreme processing in hot H-burning and gas with pristine, unprocessed composition, as also found in the recent analysis of three discrete groups in NGC6752. This finding suggests that different classes of polluters were probably at work in NGC2808 as well.

  1. HST/COS detection of deuterated molecular hydrogen in a damped Ly? system at z = 0.18

    SciTech Connect (OSTI)

    Oliveira, Cristina M.; Sembach, Kenneth R.; Tumlinson, Jason; Thom, Christopher [Space Telescope Science Institute, Baltimore, MD 21218 (United States); O'Meara, John, E-mail: oliveira@stsci.edu [Saint Michael's College, Colchester, VT 05439 (United States)

    2014-03-01

    We report on the detection of deuterated molecular hydrogen, HD, at z = 0.18. HD and H{sub 2} are detected in HST/COS data of a low-metallicity (Z ? 0.07 Z {sub ?}) damped Ly? (DLA) system at z = 0.18562 toward QSO B012028, with log N(H I) = 20.50 0.10. Four absorption components are clearly resolved in H{sub 2}, while two components are resolved in HD; the bulk of the molecular hydrogen is associated with the components traced by HD. We find total column densities log N(HD) = 14.82 0.15 and log N(H{sub 2}) = 20.00 0.10. This system has a high molecular fraction, f(H{sub 2}) = 0.39 0.10, and a low HD-to-H{sub 2} ratio, log (HD/2H{sub 2}) = 5.5 0.2 dex. The excitation temperature, T {sub 01} = 65 2 K, in the component containing the bulk of the molecular gas is lower than in other DLAs. These properties are unlike those in other higher redshift DLA systems known to contain HD, but are consistent with what is observed in dense clouds in the Milky Way.

  2. REVERSAL OF FORTUNE: INCREASED STAR FORMATION EFFICIENCIES IN THE EARLY HISTORIES OF DWARF GALAXIES?

    SciTech Connect (OSTI)

    Madau, Piero; Weisz, Daniel R.; Conroy, Charlie

    2014-08-01

    On dwarf galaxy scales, the different shapes of the galaxy stellar mass function and the dark halo mass function require a star-formation efficiency (SFE) in these systems that is currently more than 1 dex lower than that of Milky Way-size halos. Here, we argue that this trend may actually be reversed at high redshift. Specifically, by combining the resolved star-formation histories of nearby isolated dwarfs with the simulated mass-growth rates of dark matter halos, we show that the assembly of these systems occurs in two phases: (1) an early, fast halo accretion phase with a rapidly deepening potential well, characterized by a high SFE; and (2) a late, slow halo accretion phase where, perhaps as a consequence of reionization, the SFE is low. Nearby dwarfs have more old stars than predicted by assuming a constant or decreasing SFE with redshift, a behavior that appears to deviate qualitatively from the trends seen among more massive systems. Taken at face value, the data suggest that at sufficiently early epochs, dwarf galaxy halos above the atomic cooling mass limit can be among the most efficient sites of star formation in the universe.

  3. WEAK GRAVITATIONAL LENSING AS A PROBE OF PHYSICAL PROPERTIES OF SUBSTRUCTURES IN DARK MATTER HALOS

    SciTech Connect (OSTI)

    Shirasaki, Masato

    2015-02-01

    We propose a novel method to select satellite galaxies in outer regions of galaxy groups or clusters using weak gravitational lensing. The method is based on the theoretical expectation that the tangential shear pattern around satellite galaxies would appear with negative values at an offset distance from the center of the main halo. We can thus locate the satellite galaxies statistically with an offset distance of several lensing smoothing scales by using the standard reconstruction of surface mass density maps from weak lensing observation. We test the idea using high-resolution cosmological simulations. We show that subhalos separated from the center of the host halo are successfully located even without assuming the position of the center. For a number of such subhalos, the characteristic mass and offset length can be also estimated on a statistical basis. We perform a Fisher analysis to show how well upcoming weak lensing surveys can constrain the mass density profile of satellite galaxies. In the case of the Large Synoptic Survey Telescope with a sky coverage of 20,000deg{sup 2}, the mass of the member galaxies in the outer region of galaxy clusters can be constrained with an accuracy of ?0.1 dex for galaxy clusters with mass 10{sup 14} h {sup 1} M {sub ?} at z = 0.15. Finally we explore the detectability of tidal stripping features for subhalos having a wide range of masses of 10{sup 11}-10{sup 13} h {sup 1} M {sub ?}.

  4. Metal-poor dwarf galaxies in the SIGRID galaxy sample. I. H II region observations and chemical abundances

    SciTech Connect (OSTI)

    Nicholls, David C.; Dopita, Michael A.; Sutherland, Ralph S.; Jerjen, Helmut; Kewley, Lisa J.; Basurah, Hassan

    2014-05-10

    In this paper we present the results of observations of 17 H II regions in thirteen galaxies from the SIGRID sample of isolated gas-rich irregular dwarf galaxies. The spectra of all but one of the galaxies exhibit the auroral [O III] 4363 Å line, from which we calculate the electron temperature, T{sub e} , and gas-phase oxygen abundance. Five of the objects are blue compact dwarf galaxies, of which four have not previously been analyzed spectroscopically. We include one unusual galaxy which exhibits no evidence of the [N II] λλ 6548,6584 Å lines, suggesting a particularly low metallicity (< Z {sub ☉}/30). We compare the electron temperature based abundances with those derived using eight of the new strong-line diagnostics presented by Dopita et al. Using a method derived from first principles for calculating total oxygen abundance, we show that the discrepancy between the T{sub e} -based and strong-line gas-phase abundances have now been reduced to within ∼0.07 dex. The chemical abundances are consistent with what is expected from the luminosity-metallicity relation. We derive estimates of the electron densities and find them to be between ∼5 and ∼100 cm{sup –3}. We find no evidence for a nitrogen plateau for objects in this sample with metallicities 0.5 > Z {sub ☉} > 0.15.

  5. Experimental Investigation of Spark-Ignited Combustion with High-Octane Biofuels and EGR. 2. Fuel and EGR Effects on Knock-Limited Load and Speed

    SciTech Connect (OSTI)

    Splitter, Derek A; Szybist, James P

    2013-01-01

    The present study experimentally investigates spark-ignited combustion with 87 AKI E0 gasoline in its neat form and in midlevel alcohol gasoline blends with 24% vol/vol isobutanol gasoline (IB24) and 30% vol/vol ethanol gasoline (E30). A single-cylinder research engine is used with an 11.85:1 compression ratio, hydraulically actuated valves, laboratory intake air, and was capable of external exhaust gas recirculation (EGR). Experiments were conducted with all fuels to full-load conditions with = 1, using both 0% and 15% external-cooled EGR. Higher octane number biofuel blends exhibited increased stoichiometric torque capability at this compression ratio, where the unique properties of ethanol enabled a doubling of the stoichiometric torque capability with E30 as compared to that of 87AKI, up to 20 bar IMEPg (indicating mean effective pressure gross) at = 1. The results demonstrate that for all fuels, EGR is a key enabler for increasing engine efficiency but is less useful for knock mitigation with E30 than for 87AKI gasoline or IB24. Under knocking conditions, 15% EGR is found to offer 1 CA of CA50 timing advance with E30, whereas up to 5 CA of CA50 advance is possible with knock-limited 87AKI gasoline. Compared to 87AKI, both E30 and IB24 are found to have reduced adiabatic flame temperature and shorter combustion durations, which reduce knocking propensity beyond that indicated by the octane number. However, E30+0% EGR is found to exhibit the better antiknock properties than either 87AKI+15% EGR or IB24+15% EGR, expanding the knock limited operating range and engine stoichiometric torque capability at high compression ratio. Furthermore, the fuel sensitivity (S) of E30 was attributed to reduced speed sensitivity of E30, expanding the low-speed stoichiometric torque capability at high compression ratio. The results illustrate that intermediate alcohol gasoline blends exhibit exceptional antiknock properties and performance beyond that indicated by the octane number tests, particularly E30.

  6. THE ZURICH ENVIRONMENTAL STUDY (ZENS) OF GALAXIES IN GROUPS ALONG THE COSMIC WEB. V. PROPERTIES AND FREQUENCY OF MERGING SATELLITES AND CENTRALS IN DIFFERENT ENVIRONMENTS

    SciTech Connect (OSTI)

    Pipino, A.; Cibinel, A.; Tacchella, S.; Carollo, C. M.; Lilly, S. J.; Miniati, F.; Silverman, J. D.; Van Gorkom, J. H.; Finoguenov, A.

    2014-12-20

    We use the Zurich Environmental Study database to investigate the environmental dependence of the merger fraction ? and merging galaxy properties in a sample of ?1300 group galaxies with M > 10{sup 9.2} M {sub ?} and 0.05 < z < 0.0585. In all galaxy mass bins investigated in our study, we find that ? decreases by a factor of ?2-3 in groups with halo masses M {sub HALO} > 10{sup 13.5} M {sub ?} relative to less massive systems, indicating a suppression of merger activity in large potential wells. In the fiducial case of relaxed groups only, we measure a variation of ??/?log (M {sub HALO}) ? 0.07 dex{sup 1}, which is almost independent of galaxy mass and merger stage. At galaxy masses >10{sup 10.2} M {sub ?}, most mergers are dry accretions of quenched satellites onto quenched centrals, leading to a strong increase of ? with decreasing group-centric distance at these mass scales. Both satellite and central galaxies in these high-mass mergers do not differ in color and structural properties from a control sample of nonmerging galaxies of equal mass and rank. At galaxy masses of <10{sup 10.2} M {sub ?} where we mostly probe satellite-satellite pairs and mergers between star-forming systems close pairs (projected distance <10-20 kpc) show instead ?2 enhanced (specific) star formation rates and ?1.5 larger sizes than similar mass, nonmerging satellites. The increase in both size and star formation rate leads to similar surface star formation densities in the merging and control-sample satellite populations.

  7. The RR Lyrae variable population in the Phoenix dwarf galaxy

    SciTech Connect (OSTI)

    Ordoñez, Antonio J.; Sarajedini, Ata; Yang, Soung-Chul E-mail: ata@astro.ufl.edu

    2014-05-10

    We present the first detailed study of the RR Lyrae variable population in the Local Group dSph/dIrr transition galaxy, Phoenix, using previously obtained HST/WFPC2 observations of the galaxy. We utilize template light curve fitting routines to obtain best fit light curves for RR Lyrae variables in Phoenix. Our technique has identified 78 highly probable RR Lyrae stars (54 ab-type; 24 c-type) with about 40 additional candidates. We find mean periods for the two populations of (P {sub ab}) = 0.60 ± 0.03 days and (P{sub c} ) = 0.353 ± 0.002 days. We use the properties of these light curves to extract, among other things, a metallicity distribution function for ab-type RR Lyrae. Our analysis yields a mean metallicity of ([Fe/H]) = –1.68 ± 0.06 dex for the RRab stars. From the mean period and metallicity calculated from the ab-type RR Lyrae, we conclude that Phoenix is more likely of intermediate Oosterhoff type; however the morphology of the Bailey diagram for Phoenix RR Lyraes appears similar to that of an Oosterhoff type I system. Using the RRab stars, we also study the chemical enrichment law for Phoenix. We find that our metallicity distribution is reasonably well fitted by a closed-box model. The parameters of this model are compatible with the findings of Hidalgo et al., further supporting the idea that Phoenix appears to have been chemically enriched as a closed-box-like system during the early stage of its formation and evolution.

  8. THE CONNECTION BETWEEN GALAXIES AND DARK MATTER STRUCTURES IN THE LOCAL UNIVERSE

    SciTech Connect (OSTI)

    Reddick, Rachel M.; Wechsler, Risa H.; Behroozi, Peter S.; Tinker, Jeremy L. E-mail: rwechsler@stanford.edu

    2013-07-01

    We provide new constraints on the connection between galaxies in the local universe, identified by the Sloan Digital Sky Survey, and dark matter halos and their constituent substructures in the {Lambda}-cold dark matter model using WMAP7 cosmological parameters. Predictions for the abundance and clustering properties of dark matter halos, and the relationship between dark matter hosts and substructures, are based on a high-resolution cosmological simulation, the Bolshoi simulation. We associate galaxies with dark matter halos and subhalos using subhalo abundance matching, and perform a comprehensive analysis which investigates the underlying assumptions of this technique including (1) which halo property is most closely associated with galaxy stellar masses and luminosities, (2) how much scatter is in this relationship, and (3) how much subhalos can be stripped before their galaxies are destroyed. The models are jointly constrained by new measurements of the projected two-point galaxy clustering and the observed conditional stellar mass function of galaxies in groups. We find that an abundance matching model that associates galaxies with the peak circular velocity of their halos is in good agreement with the data, when scatter of 0.20 {+-} 0.03 dex in stellar mass at a given peak velocity is included. This confirms the theoretical expectation that the stellar mass of galaxies is tightly correlated with the potential wells of their dark matter halos before they are impacted by larger structures. The data put tight constraints on the satellite fraction of galaxies as a function of galaxy stellar mass and on the scatter between halo and galaxy properties, and rule out several alternative abundance matching models that have been considered. This will yield important constraints for galaxy formation models, and also provides encouraging indications that the galaxy-halo connection can be modeled with sufficient fidelity for future precision studies of the dark universe.

  9. Resolved star formation on sub-galactic scales in a merger at z = 1.7

    SciTech Connect (OSTI)

    Whitaker, Katherine E.; Rigby, Jane R.; Teng, Stacy H.; Brammer, Gabriel B.; Gladders, Michael D.; Sharon, Keren; Wuyts, Eva

    2014-08-01

    We present a detailed analysis of Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) G141 grism spectroscopy for seven star-forming regions of the highly magnified lensed starburst galaxy RCSGA 032727-132609 at z = 1.704. We measure the spatial variations of the extinction in RCS0327 through the observed H?/H? emission line ratios, finding a constant average extinction of E(B V){sub gas} = 0.40 0.07. We infer that the star formation is enhanced as a result of an ongoing interaction, with measured star formation rates derived from demagnified, extinction-corrected H? line fluxes for the individual star-forming clumps falling >1-2 dex above the star formation sequence. When combining the HST/WFC3 [O III] ?5007/H? emission line ratio measurements with [N II]/H? line ratios from Wuyts et al., we find that the majority of the individual star-forming regions fall along the local 'normal' abundance sequence. With the first detections of the He I ?5876 and He II ?4686 recombination lines in a distant galaxy, we probe the massive-star content of the star-forming regions in RCS0327. The majority of the star-forming regions have a He I ?5876 to H? ratio consistent with the saturated maximum value, which is only possible if they still contain hot O-stars. Two regions have lower ratios, implying that their last burst of new star formation ended ?5 Myr ago. Together, the He I ?5876 and He II ?4686 to H? line ratios provide indirect evidence for the order in which star formation is stopping in individual star-forming knots of this high-redshift merger. We place the spatial variations of the extinction, star formation rate and ionization conditions in the context of the star formation history of RCS0327.

  10. The Connection between Galaxies and Dark Matter Structures in the Local Universe

    SciTech Connect (OSTI)

    Reddick, Rachel M.; Wechsler, Risa H.; Tinker, Jeremy L.; Behroozi, Peter S.

    2012-07-11

    We provide new constraints on the connection between galaxies in the local Universe, identified by the Sloan Digital Sky Survey (SDSS), and dark matter halos and their constituent substructures in the {Lambda}CDM model using WMAP7 cosmological parameters. Predictions for the abundance and clustering properties of dark matter halos, and the relationship between dark matter hosts and substructures, are based on a high-resolution cosmological simulation, the Bolshoi simulation. We associate galaxies with dark matter halos and subhalos using subhalo abundance matching, and perform a comprehensive analysis which investigates the underlying assumptions of this technique including (a) which halo property is most closely associated with galaxy stellar masses and luminosities, (b) how much scatter is in this relationship, and (c) how much subhalos can be stripped before their galaxies are destroyed. The models are jointly constrained by new measurements of the projected two-point galaxy clustering and the observed conditional stellar mass function of galaxies in groups. We find that an abundance matching model that associates galaxies with the peak circular velocity of their halos is in good agreement with the data, when scatter of 0.20 {+-} 0.03 dex in stellar mass at a given peak velocity is included. This confirms the theoretical expectation that the stellar mass of galaxies is tightly correlated with the potential wells of their dark matter halos before they are impacted by larger structures. The data put tight constraints on the satellite fraction of galaxies as a function of galaxy stellar mass and on the scatter between halo and galaxy properties, and rule out several alternative abundance matching models that have been considered. This will yield important constraints for galaxy formation models, and also provides encouraging indications that the galaxy - halo connection can be modeled with sufficient fidelity for future precision studies of the dark Universe.

  11. The trace of the CNO cycle in the ring nebula NGC 6888

    SciTech Connect (OSTI)

    Mesa-Delgado, A.; Esteban, C.; Garca-Rojas, J.; Reyes-Prez, J.; Morisset, C.; Bresolin, F.

    2014-04-20

    We present new results on the chemical composition of the Galactic ring nebula NGC 6888 surrounding the WN6(h) star WR136. The data are based on deep spectroscopical observations taken with the High Dispersion Spectrograph at the 8.2 m Subaru Telescope. The spectra cover the optical range from 3700 to 7400 . The effect of the CNO cycle is well-identified in the abundances of He, N, and O, while elements not involved in the synthesis such as Ar, S, and Fe present values consistent with the solar vicinity and the ambient gas. The major achievement of this work is the first detection of the faint C II ?4267 recombination line in a Wolf-Rayet nebula. This allows us to estimate the C abundance in NGC 6888 and therefore investigate for the first time the trace of the CNO cycle in a ring nebula around a Wolf-Rayet star. Although the detection of the C II line has a low signal-to-noise ratio, the C abundance seems to be higher than the predictions of recent stellar evolution models of massive stars. The Ne abundance also shows a puzzling pattern with an abundance of about 0.5 dex lower than the solar vicinity, which may be related to the action of the NeNa cycle. Attending to the constraints imposed by the dynamical timescale and the He/H and N/O ratios of the nebula, the comparison with stellar evolution models indicates that the initial mass of the stellar progenitor of NGC 6888 is between 25 M {sub ?} and 40 M {sub ?}.

  12. Atmospheric parameters and metallicities for 2191 stars in the globular cluster M4

    SciTech Connect (OSTI)

    Malavolta, Luca; Piotto, Giampaolo; Nascimbeni, Valerio; Sneden, Christopher; Milone, Antonino P.; Bedin, Luigi R. E-mail: giampaolo.piotto@unipd.it E-mail: luigi.bedin@oapd.inaf.it E-mail: milone@mso.anu.edu.au

    2014-02-01

    We report new metallicities for stars of Galactic globular cluster M4 using the largest number of stars ever observed at high spectral resolution in any cluster. We analyzed 7250 spectra for 2771 cluster stars gathered with the Very Large Telescope (VLT) FLAMES+GIRAFFE spectrograph at VLT. These medium-resolution spectra cover a small wavelength range, and often have very low signal-to-noise ratios. We approached this data set by reconsidering the whole method of abundance analysis of large stellar samples from beginning to end. We developed a new algorithm that automatically determines the atmospheric parameters of a star. Nearly all of the data preparation steps for spectroscopic analyses are processed on the syntheses, not the observed spectra. For 322 red giant branch (RGB) stars with V ≤ 14.7, we obtain a nearly constant metallicity, ([Fe/H]) = –1.07 (σ = 0.02). No difference in the metallicity at the level of 0.01 dex is observed between the two RGB sequences identified by Monelli et al. For 1869 subgiant and main-sequence stars with V > 14.7, we obtain ([Fe/H]) = –1.16 (σ = 0.09) after fixing the microturbulent velocity. These values are consistent with previous studies that have performed detailed analyses of brighter RGB stars at higher spectroscopic resolution and wavelength coverage. It is not clear if the small mean metallicity difference between brighter and fainter M4 members is real or is the result of the low signal-to-noise characteristics of the fainter stars. The strength of our approach is shown by recovering a metallicity close to a single value for more than 2000 stars, using a data set that is non-optimal for atmospheric analyses. This technique is particularly suitable for noisy data taken in difficult observing conditions.

  13. BRIGHTEST X-RAY CLUSTERS OF GALAXIES IN THE CFHTLS WIDE FIELDS: CATALOG AND OPTICAL MASS ESTIMATOR

    SciTech Connect (OSTI)

    Mirkazemi, M.; Finoguenov, A.; Lerchster, M.; Erfanianfar, G.; Seitz, S.; Pereira, M. J.; Egami, E.; Tanaka, M.; Brimioulle, F.; Kettula, K.; McCracken, H. J.; Mellier, Y.; Kneib, J. P.; Rykoff, E.; Erben, T.; Taylor, J. E.

    2015-01-20

    The Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) presents a unique data set for weak-lensing studies, having high-quality imaging and deep multiband photometry. We have initiated an XMM-CFHTLS project to provide X-ray observations of the brightest X-ray-selected clusters within the wide CFHTLS area. Performance of these observations and the high quality of CFHTLS data allow us to revisit the identification of X-ray sources, introducing automated reproducible algorithms, based on the multicolor red sequence finder. We have also introduced a new optical mass proxy. We provide the calibration of the red sequence observed in the Canada-France-Hawaii filters and compare the results with the traditional single-color red sequence and photo-z. We test the identification algorithm on the subset of highly significant XMM clusters and identify 100% of the sample. We find that the integrated z-band luminosity of the red sequence galaxies correlates well with the X-ray luminosity, with a surprisingly small scatter of 0.20 dex. We further use the multicolor red sequence to reduce spurious detections in the full XMM and ROSAT All-Sky Survey (RASS) data sets, resulting in catalogs of 196 and 32 clusters, respectively. We made spectroscopic follow-up observations of some of these systems with HECTOSPEC and in combination with BOSS DR9 data. We also describe the modifications needed to the source detection algorithm in order to maintain high purity of extended sources in the shallow X-ray data. We also present the scaling relation between X-ray luminosity and velocity dispersion.

  14. Understanding the observed evolution of the galaxy luminosity function from z = 610 in the context of hierarchical structure formation

    SciTech Connect (OSTI)

    Muoz, Joseph A.

    2012-04-01

    Recent observations of the Lyman-break galaxy (LBG) luminosity function (LF) from z ? 610 show a steep decline in abundance with increasing redshift. However, the LF is a convolution of the mass function of dark matter halos (HMF) which also declines sharply over this redshift range and the galaxy-formation physics that maps halo mass to galaxy luminosity. We consider the strong observed evolution in the LF from z ? 610 in this context and determine whether it can be explained solely by the behavior of the HMF. From z ? 68, we find a residual change in the physics of galaxy formation corresponding to a ? 0.5 dex increase in the average luminosity of a halo of fixed mass. On the other hand, our analysis of recent LF measurements at z ? 10 shows that the paucity of detected galaxies is consistent with almost no change in the average luminosity at fixed halo mass from z ? 8. The LF slope also constrains the variation about this mean such that the luminosity of galaxies hosted by halos of the same mass are all within about an order-of-magnitude of each other. We show that these results are well-described by a simple model of galaxy formation in which cold-flow accretion is balanced by star formation and momentum-driven outflows. If galaxy formation proceeds in halos with masses down to 10{sup 8}M{sub s}un, then such a model predicts that LBGs at z ? 10 should be able to maintain an ionized intergalactic medium as long as the ratio of the clumping factor to the ionizing escape fraction is C/f{sub esc}?<10.

  15. SDSS/SEGUE spectral feature analysis for stellar atmospheric parameter estimation

    SciTech Connect (OSTI)

    Li, Xiangru; Lu, Yu; Yang, Tan; Wang, Yongjun; Wu, Q. M. Jonathan; Luo, Ali; Zhao, Yongheng; Zuo, Fang

    2014-08-01

    Large-scale and deep sky survey missions are rapidly collecting a large amount of stellar spectra, which necessitate the estimation of atmospheric parameters directly from spectra and make it feasible to statistically investigate latent principles in a large data set. We present a technique for estimating parameters T{sub eff}, log g, and [Fe/H] from stellar spectra. With this technique, we first extract features from stellar spectra using the LASSO algorithm; then, the parameters are estimated from the extracted features using the support vector regression. On a subsample of 20,000 stellar spectra from the Sloan Digital Sky Survey (SDSS) with reference parameters provided by the SDSS/SEGUE Spectroscopic Parameter Pipeline, estimation consistency are 0.007458 dex for log T{sub eff} (101.609921 K for T{sub eff}), 0.189557 dex for log g, and 0.182060 for [Fe/H], where the consistency is evaluated by mean absolute error. Prominent characteristics of the proposed scheme are sparseness, locality, and physical interpretability. In this work, each spectrum consists of 3821 fluxes, and 10, 19, and 14 typical wavelength positions are detected, respectively, for estimating T{sub eff}, log g, and [Fe/H]. It is shown that the positions are related to typical lines of stellar spectra. This characteristic is important in investigating physical indications from analysis results. Then, stellar spectra can be described by the individual fluxes on the detected positions (PD) or local integration of fluxes near them (LI). The aforementioned consistency is the result based on features described by LI. If features are described by PD, consistency is 0.009092 dex for log T{sub eff} (124.545075 K for T{sub eff}), 0.198928 dex for log g, and 0.206814 dex for [Fe/H].

  16. TYPE Ia SUPERNOVA REMNANT SHELL AT z = 3.5 SEEN IN THE THREE SIGHTLINES TOWARD THE GRAVITATIONALLY LENSED QSO B1422+231

    SciTech Connect (OSTI)

    Hamano, Satoshi; Kobayashi, Naoto [Institute of Astronomy, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Kondo, Sohei [Koyama Astronomical Observatory, Kyoto-Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto 603-8555 (Japan); Tsujimoto, Takuji [National Astronomical Observatory of Japan and Department of Astronomical Science, Graduate University for Advanced Studies, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Okoshi, Katsuya [Faculty of Industrial Science and Technology, Tokyo University of Science, 102-1 Tomino, Oshamanbe, Hokkaido 049-3514 (Japan); Shigeyama, Toshikazu, E-mail: hamano@ioa.s.u-tokyo.ac.jp [Research Center for the Early Universe, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan)

    2012-08-01

    Using the Subaru 8.2 m Telescope with the IRCS Echelle spectrograph, we obtained high-resolution (R = 10,000) near-infrared (1.01-1.38 {mu}m) spectra of images A and B of the gravitationally lensed QSO B1422+231 (z = 3.628) consisting of four known lensed images. We detected Mg II absorption lines at z = 3.54, which show a large variance of column densities ({approx}0.3 dex) and velocities ({approx}10 km s{sup -1}) between sightlines A and B with a projected separation of only 8.4h{sup -1}{sub 70} pc at that redshift. This is the smallest spatial structure of the high-z gas clouds ever detected after Rauch et al. found a 20 pc scale structure for the same z = 3.54 absorption system using optical spectra of images A and C. The observed systematic variances imply that the system is an expanding shell as originally suggested by Rauch et al. By combining the data for three sightlines, we managed to constrain the radius and expansion velocity of the shell ({approx}50-100 pc, 130 km s{sup -1}), concluding that the shell is truly a supernova remnant (SNR) rather than other types of shell objects, such as a giant H II region. We also detected strong Fe II absorption lines for this system, but with much broader Doppler width than that of {alpha}-element lines. We suggest that this Fe II absorption line originates in a localized Fe II-rich gas cloud that is not completely mixed with plowed ambient interstellar gas clouds showing other {alpha}-element low-ion absorption lines. Along with the Fe richness, we conclude that the SNR is produced by an SN Ia explosion.

  17. Parallel In Situ Indexing for Data-intensive Computing

    SciTech Connect (OSTI)

    Kim, Jinoh; Abbasi, Hasan; Chacon, Luis; Docan, Ciprian; Klasky, Scott; Liu, Qing; Podhorszki, Norbert; Shoshani, Arie; Wu, Kesheng

    2011-09-09

    As computing power increases exponentially, vast amount of data is created by many scientific re- search activities. However, the bandwidth for storing the data to disks and reading the data from disks has been improving at a much slower pace. These two trends produce an ever-widening data access gap. Our work brings together two distinct technologies to address this data access issue: indexing and in situ processing. From decades of database research literature, we know that indexing is an effective way to address the data access issue, particularly for accessing relatively small fraction of data records. As data sets increase in sizes, more and more analysts need to use selective data access, which makes indexing an even more important for improving data access. The challenge is that most implementations of in- dexing technology are embedded in large database management systems (DBMS), but most scientific datasets are not managed by any DBMS. In this work, we choose to include indexes with the scientific data instead of requiring the data to be loaded into a DBMS. We use compressed bitmap indexes from the FastBit software which are known to be highly effective for query-intensive workloads common to scientific data analysis. To use the indexes, we need to build them first. The index building procedure needs to access the whole data set and may also require a significant amount of compute time. In this work, we adapt the in situ processing technology to generate the indexes, thus removing the need of read- ing data from disks and to build indexes in parallel. The in situ data processing system used is ADIOS, a middleware for high-performance I/O. Our experimental results show that the indexes can improve the data access time up to 200 times depending on the fraction of data selected, and using in situ data processing system can effectively reduce the time needed to create the indexes, up to 10 times with our in situ technique when using identical parallel settings.

  18. AGB sodium abundances in the globular cluster 47 Tucanae (NGC 104)

    SciTech Connect (OSTI)

    Johnson, Christian I.; McDonald, Iain; Zijlstra, Albert A. E-mail: iain.mcdonald-2@manchester.ac.uk; and others

    2015-02-01

    A recent analysis comparing the [Na/Fe] distributions of red giant branch (RGB) and asymptotic giant branch (AGB) stars in the Galactic globular cluster NGC 6752 found that the ratio of Na-poor to Na-rich stars changes from 30:70 on the RGB to 100:0 on the AGB. The surprising paucity of Na-rich stars on the AGB in NGC 6752 warrants additional investigations to determine if the failure of a significant fraction of stars to ascend the AGB is an attribute common to all globular clusters. Therefore, we present radial velocities, [Fe/H], and [Na/Fe] abundances for 35 AGB stars in the Galactic globular cluster 47 Tucanae (47 Tuc; NGC 104), and compare the AGB [Na/Fe] distribution with a similar RGB sample published previously. The abundances and velocities were derived from high-resolution spectra obtained with the Michigan/Magellan Fiber System and MSpec spectrograph on the MagellanClay 6.5 m telescope. We find the average heliocentric radial velocity and [Fe/H] values to be ?RV{sub helio.}? = ?18.56 km s{sup ?1} (? = 10.21 km s{sup ?1}) and ?[Fe/H]? = ?0.68 (? = 0.08), respectively, in agreement with previous literature estimates. The average [Na/Fe] abundance is 0.12 dex lower in the 47 Tuc AGB sample compared to the RGB sample, and the ratio of Na-poor to Na-rich stars is 63:37 on the AGB and 45:55 on the RGB. However, in contrast to NGC 6752, the two 47 Tuc populations have nearly identical [Na/Fe] dispersion and interquartile range values. The data presented here suggest that only a small fraction (?20%) of Na-rich stars in 47 Tuc may fail to ascend the AGB, which is a similar result to that observed in M13. Regardless of the cause for the lower average [Na/Fe] abundance in AGB stars, we find that Na-poor stars and at least some Na-rich stars in 47 Tuc evolve through the early AGB phase. The contrasting behavior of Na-rich stars in 47 Tuc and NGC 6752 suggests that the RGB [Na/Fe] abundance alone is insufficient for predicting if a star will ascend the AGB.

  19. Reverberation measurements of the inner radius of the dust torus in 17 Seyfert galaxies

    SciTech Connect (OSTI)

    Koshida, Shintaro; Minezaki, Takeo; Yoshii, Yuzuru; Sakata, Yu; Sugawara, Shota; Kobayashi, Yukiyasu; Suganuma, Masahiro; Enya, Keigo; Tomita, Hiroyuki; Aoki, Tsutomu; Peterson, Bruce A. E-mail: minezaki@ioa.s.u-tokyo.ac.jp

    2014-06-20

    We present the results of a dust reverberation survey for 17 nearby Seyfert 1 galaxies, which provides the largest homogeneous data collection for the radius of the innermost dust torus. A delayed response of the K-band light curve after the V-band light curve was found for all targets, and 49 measurements of lag times between the flux variation of the dust emission in the K band and that of the optical continuum emission in the V band were obtained by the cross-correlation function analysis and also by an alternative method for estimating the maximum likelihood lag. The lag times strongly correlated with the optical luminosity in the luminosity range of M{sub V} = –16 to –22 mag, and the regression analysis was performed to obtain the correlation log Δt (days) = –2.11 – 0.2 M{sub V} assuming Δt∝L {sup 0.5}, which was theoretically expected. We discuss the possible origins of the intrinsic scatter of the dust lag-luminosity correlation, which was estimated to be approximately 0.13 dex, and we find that the difference of internal extinction and delayed response of changes in lag times to the flux variations could have partly contributed to intrinsic scatter. However, we could not detect any systematic change of the correlation with the subclass of the Seyfert type or the Eddington ratio. Finally, we compare the dust reverberation radius with the near-infrared interferometric radius of the dust torus and the reverberation radius of broad Balmer emission lines. The interferometric radius in the K band was found to be systematically larger than the dust reverberation radius in the same band by the about a factor of two, which could be interpreted by the difference between the flux-weighted radius and response-weighted radius of the innermost dust torus. The reverberation radius of the broad Balmer emission lines was found to be systematically smaller than the dust reverberation radius by about a factor of four to five, which strongly supports the unified scheme of the Seyfert type of active galactic nuclei (AGNs). Moreover, we examined the radius-luminosity correlations for the hard X-ray (14-195 keV) and the [O IV] λ25.89 μm emission-line luminosities, which would be applicable for obscured AGNs.

  20. ONE PLANE FOR ALL: MASSIVE STAR-FORMING AND QUIESCENT GALAXIES LIE ON THE SAME MASS FUNDAMENTAL PLANE AT z ? 0 AND z ? 0.7

    SciTech Connect (OSTI)

    Bezanson, Rachel; Franx, Marijn; Van Dokkum, Pieter G.

    2015-02-01

    Scaling relations between galaxy structures and dynamics have been studied extensively for early- and late-type galaxies, both in the local universe and at high redshifts. The abundant differences between the properties of disky and elliptical, or star-forming and quiescent, galaxies seem to be characteristic of the local universe; such clear distinctions begin to disintegrate as observations of massive galaxies probe higher redshifts. In this paper we investigate the existence of the mass fundamental plane of all massive galaxies (? ? 100 km s{sup 1}). This work includes local galaxies (0.05 < z < 0.07) from the Sloan Digital Sky Survey, in addition to 31 star-forming and 72 quiescent massive galaxies at intermediate redshift (z ? 0.7) with absorption-line kinematics from deep Keck-DEIMOS spectra and structural parameters from Hubble Space Telescope imaging. In two-parameter scaling relations, star-forming and quiescent galaxies differ structurally and dynamically. However, we show that massive star-forming and quiescent galaxies lie on nearly the same mass fundamental plane, or the relationship between stellar mass surface density, stellar velocity dispersion, and effective radius. The scatter in this relation (measured about log ?) is low: 0.072 dex (0.055 dex intrinsic) at z ? 0 and 0.10 dex (0.08 dex intrinsic) at z ? 0.7. This 3D surface is not unique: virial relations, with or without a dependence on luminosity profile shapes, can connect galaxy structures and stellar dynamics with similar scatter. This result builds on the recent finding that mass fundamental plane has been stable for early-type galaxies since z ? 2. As we now find that this also holds for star-forming galaxies to z ? 0.7, this implies that these scaling relations of galaxies will be minimally susceptible to progenitor biases owing to the evolving stellar populations, structures, and dynamics of galaxies through cosmic time.

  1. A comparison of ethanol and butanol as oxygenates using a direct-injection, spark-ignition (DISI) engine.

    SciTech Connect (OSTI)

    Wallner, T.; Miers, S. A.; McConnell, S.

    2009-05-01

    This study was designed to evaluate a 'what if' scenario in terms of using butanol as an oxygenate in place of ethanol in an engine calibrated for gasoline operation. No changes to the stock engine calibration were performed for this study. Combustion analysis, efficiency, and emissions of pure gasoline, 10% ethanol, and 10% butanol blends in a modern direct-injection four-cylinder spark-ignition engine were analyzed. Data were taken at engine speeds of 1000 rpm up to 4000 rpm with load varying from 0 N m (idle) to 150 N m. Relatively minor differences existed between the three fuels for the combustion characteristics such as heat release rate, 50% mass fraction burned, and coefficient of variation in indicated mean effective pressure at low and medium engine loads. However at high engine loads the reduced knock resistance of the butanol blend forced the engine control unit to retard the ignition timing substantially, compared with the gasoline baseline and, even more pronounced, compared with the ethanol blend. Brake specific volumetric fuel consumption, which represented a normalized volumetric fuel flow rate, was lowest for the gasoline baseline fuel due to the higher energy density. The 10% butanol blend had a lower volumetric fuel consumption compared with the ethanol blend, as expected, based on energy density differences. The results showed little difference in regulated emissions between 10% ethanol and 10% butanol. The ethanol blend produced the highest peak specific NO{sub x} due to the high octane rating of ethanol and effective antiknock characteristics. Overall, the ability of butanol to perform equally as well as ethanol from an emissions and combustion standpoint, with a decrease in fuel consumption, initially appears promising. Further experiments are planned to explore the full operating range of the engine and the potential benefits of higher blend ratios of butanol.

  2. TRACING THE ORPHAN STREAM TO 55 kpc WITH RR LYRAE STARS

    SciTech Connect (OSTI)

    Sesar, Branimir; Cohen, Judith G.; Bellm, Eric C.; Levitan, David; Tang, Sumin; Waszczak, Adam; Kulkarni, Shrinivas R.; Prince, Thomas A.; Grillmair, Carl J.; Laher, Russ R.; Surace, Jason A.; Bhalerao, Varun B.; Ofek, Eran O.

    2013-10-10

    We report positions, velocities, and metallicities of 50 ab-type RR Lyrae (RRab) stars observed in the vicinity of the Orphan stellar stream. Using about 30 RRab stars classified as being likely members of the Orphan stream, we study the metallicity and the spatial extent of the stream. We find that RRab stars in the Orphan stream have a wide range of metallicities, from 1.5 dex to 2.7 dex. The average metallicity of the stream is 2.1 dex, identical to the value obtained by Newberg et al. using blue horizontal branch stars. We find that the most distant parts of the stream (40-50 kpc from the Sun) are about 0.3 dex more metal-poor than the closer parts (within ?30 kpc), suggesting a possible metallicity gradient along the stream's length. We have extended the previous studies and have mapped the stream up to 55 kpc from the Sun. Even after a careful search, we did not identify any more distant RRab stars that could plausibly be members of the Orphan stream. If confirmed with other tracers, this result would indicate a detection of the end of the leading arm of the stream. We have compared the distances of Orphan stream RRab stars with the best-fit orbits obtained by Newberg et al. We find that model 6 of Newberg et al. cannot explain the distances of the most remote Orphan stream RRab stars, and conclude that the best fit to distances of Orphan stream RRab stars and to the local circular velocity is provided by potentials where the total mass of the Galaxy within 60 kpc is M{sub 60} ? 2.7 10{sup 11} M{sub ?}, or about 60% of the mass found by previous studies. More extensive modeling that would consider non-spherical potentials and the possibility of misalignment between the stream and the orbit is highly encouraged.

  3. Novel Characterization of GDI Engine Exhaust for Gasoline and Mid-Level Gasoline-Alcohol Blends

    SciTech Connect (OSTI)

    Storey, John Morse; Lewis Sr, Samuel Arthur; Szybist, James P; Thomas, John F; Barone, Teresa L; Eibl, Mary A; Nafziger, Eric J; Kaul, Brian C

    2014-01-01

    Gasoline direct injection (GDI) engines can offer improved fuel economy and higher performance over their port fuel-injected (PFI) counterparts, and are now appearing in increasingly more U.S. and European vehicles. Small displacement, turbocharged GDI engines are replacing large displacement engines, particularly in light-duty trucks and sport utility vehicles, in order for manufacturers to meet more stringent fuel economy standards. GDI engines typically emit the most particulate matter (PM) during periods of rich operation such as start-up and acceleration, and emissions of air toxics are also more likely during this condition. A 2.0 L GDI engine was operated at lambda of 0.91 at typical loads for acceleration (2600 rpm, 8 bar BMEP) on three different fuels; an 87 anti-knock index (AKI) gasoline (E0), 30% ethanol blended with the 87 AKI fuel (E30), and 48% isobutanol blended with the 87 AKI fuel. E30 was chosen to maximize octane enhancement while minimizing ethanol-blend level and iBu48 was chosen to match the same fuel oxygen level as E30. Particle size and number, organic carbon and elemental carbon (OC/EC), soot HC speciation, and aldehydes and ketones were all analyzed during the experiment. A new method for soot HC speciation is introduced using a direct, thermal desorption/pyrolysis inlet for the gas chromatograph (GC). Results showed high levels of aromatic compounds were present in the PM, including downstream of the catalyst, and the aldehydes were dominated by the alcohol blending.

  4. Improving the Understanding of Intake and Charge Effects for Increasing RCCI Engine Efficiency

    SciTech Connect (OSTI)

    Splitter, Derek A; Reitz, Rolf; Wissink, martin; DelVescovo, Dan

    2014-01-01

    The present experimental engine efficiency study explores the effects of intake pressure and temperature, and premixed and global equivalence ratios on gross thermal efficiency (GTE) using the reactivity controlled compression ignition (RCCI) combustion strategy. Experiments were conducted in a heavy-duty single-cylinder engine at constant net load (IMEPn) of 8.45 bar, 1300 rev/min engine speed, with 0% EGR, and a 50% mass fraction burned combustion phasing (CA50) of 0.5 CA ATDC. The engine was port fueled with E85 for the low reactivity fuel and direct injected with 3.5% 2-ethylhexyl nitrate (EHN) doped into 91 anti-knock index (AKI) gasoline for the high-reactivity fuel. The resulting reactivity of the enhanced fuel corresponds to an AKI of approximately 56 and a cetane number of approximately 28. The engine was operated with a wide range of intake pressures and temperatures, and the ratio of low- to high-reactivity fuel was adjusted to maintain a fixed speed-phasing-load condition. This allowed for the investigation of several combinations of intake temperature, intake pressure, and charge stratification at otherwise constant thermodynamic conditions. The results show that sources of engine inefficiency compete as functions of premixed and global equivalence ratios. Losses are minimized through proper balancing of intake pressure and temperature, such that the global equivalence ratio ( global) is as lean as possible without overly lean regions of the stratified charge causing an increase in incomplete combustion. The explored speed-load-phasing combination shows that losses are minimized at conditions where approximately 2/3 of the fuel is fully premixed. The results exhibit a pathway for achieving simultaneous increases in combustion and fuel efficiency through proper fuel reactivity and initial condition management.

  5. Ceci N'est Pas a globular cluster: the metallicity distribution of the stellar system Terzan 5

    SciTech Connect (OSTI)

    Massari, D.; Mucciarelli, A.; Ferraro, F. R.; Lanzoni, B.; Dalessandro, E.; Lovisi, L. [Dipartimento di Fisica e Astronomia, Universit degli Studi di Bologna, v.le Berti Pichat 6/2, I-40127 Bologna (Italy); Origlia, L.; Bellazzini, M. [INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Rich, R. M.; Reitzel, D. [Department of Physics and Astronomy, Math-Sciences 8979, UCLA, Los Angeles, CA 90095-1562 (United States); Valenti, E. [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei Mnchen (Germany); Ibata, R. [Observatoire Astronomique, Universit de Strasbourg, CNRS, 11, rue de l'Universit. F-67000 Strasbourg (France)

    2014-11-01

    We present new determinations of the iron abundance for 220 stars belonging to the stellar system Terzan 5 in the Galactic bulge. The spectra have been acquired with FLAMES at the Very Large Telescope of the European Southern Observatory and DEIMOS at the Keck II Telescope. This is by far the largest spectroscopic sample of stars ever observed in this stellar system. From this data set, a subsample of targets with spectra unaffected by TiO bands was extracted and statistically decontaminated from field stars. Once combined with 34 additional stars previously published by our group, a total sample of 135 member stars covering the entire radial extent of the system has been used to determine the metallicity distribution function of Terzan 5. The iron distribution clearly shows three peaks: a super-solar component at [Fe/H] ? 0.25 dex, accounting for ?29% of the sample, a dominant sub-solar population at [Fe/H] ? 0.30 dex, corresponding to ?62% of the total, and a minor (6%) metal-poor component at [Fe/H] ? 0.8 dex. Such a broad, multi-modal metallicity distribution demonstrates that Terzan 5 is not a genuine globular cluster but the remnant of a much more complex stellar system.

  6. Ultraluminous infrared galaxies in the AKARI all-sky survey

    SciTech Connect (OSTI)

    Kilerci Eser, E., E-mail: ecekilerci@dark-cosmology.dk [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Goto, T. [National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Doi, Y., E-mail: tomo@phys.nthu.edu.tw, E-mail: doi@ea.c.u-tokyo.ac.jp [The University of Tokyo, Komaba 3-8-1, Meguro, Tokyo 153-8902 (Japan)

    2014-12-10

    We present a new catalog of 118 ultraluminous infrared galaxies (ULIRGs) and one hyperluminous infrared galaxy (HLIRG) by cross-matching the AKARI all-sky survey with the Sloan Digital Sky Survey Data Release 10 (SDSS DR10) and the final data release of the Two-Degree Field Galaxy Redshift Survey. Forty of the ULIRGs and one HLIRG are new identifications. We find that ULIRGs are interacting pair galaxies or ongoing or postmergers. This is consistent with the widely accepted view: ULIRGs are major mergers of disk galaxies. We confirm the previously known positive trend between the active galactic nucleus fraction and infrared luminosity. We show that ULIRGs have a large offset from the main sequence up to z ? 1; their offset from the z ? 2 'main sequence' is relatively smaller. We find a result consistent with the previous studies showing that, compared to local star-forming SDSS galaxies of similar mass, local ULIRGs have lower oxygen abundances. We demonstrate for the first time that ULIRGs follow the fundamental metallicity relation (FMR). The scatter of ULIRGs around the FMR (0.09 dex-0.5 dex) is comparable to the scatter of z ? 2-3 galaxies. We provide the largest local (0.050

  7. Single-epoch black hole mass estimators for broad-line active galactic nuclei: recalibrating H? with a new approach

    SciTech Connect (OSTI)

    Feng, Hua; Li, Hong [Department of Engineering Physics and Center for Astrophysics, Tsinghua University, Beijing 100084 (China); Shen, Yue [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)

    2014-10-10

    Based on an updated H? reverberation mapping (RM) sample of 44 nearby active galactic nuclei (AGNs), we propose a novel approach for black hole (BH) mass estimation using two filtered luminosities computed from single-epoch (SE) AGN spectra around the H? region. We found that the two optimal-filter luminosities extract virial information (size and virial velocity of the broad-line region, BLR) from the spectra, justifying their usage in this empirical BH mass estimator. The major advantages of this new recipe over traditional SE BH mass estimators utilizing continuum luminosity and broad-line width are (1) it has a smaller intrinsic scatter of 0.28 dex calibrated against RM masses, (2) it is extremely simple to use in practice, without any need to decompose the spectrum, and (3) it produces unambiguous and highly repeatable results even with low signal-to-noise spectra. The combination of the two luminosities can also cancel out, to some extent, systematic luminosity errors potentially introduced by uncertainties in distance or flux calibration. In addition, we recalibrated the traditional SE mass estimators using broad H? FWHM and monochromatic continuum luminosity at 5100 (L {sub 5100}). We found that using the best-fit slopes on FWHM and L {sub 5100} (derived from fitting the BLR radius-luminosity relation and the correlation between rms line dispersion and SE FWHM, respectively) rather than simple assumptions (e.g., 0.5 for L {sub 5100} and 2 for FWHM) leads to more precise SE mass estimates, improving the intrinsic scatter from 0.41 dex to 0.36 dex with respect to the RM masses. We compared different estimators and discussed their applications to the Sloan Digital Sky Survey quasar sample. Due to the limitations of the current RM sample, application of any SE recipe calibrated against RM masses to distant quasars should be treated with caution.

  8. ABUNDANCES OF C, N, Sr, AND Ba ON THE RED GIANT BRANCH OF {omega} CENTAURI

    SciTech Connect (OSTI)

    Stanford, Laura M.; Da Costa, G. S.; Norris, John E. E-mail: gdc@mso.anu.edu.a

    2010-05-10

    Abundances relative to iron for carbon, nitrogen, strontium, and barium are presented for 33 stars on the red giant branch (RGB) of the globular cluster {omega} Centauri. They are based on intermediate-resolution spectroscopic data covering the blue spectral region analyzed using spectrum synthesis techniques. The data reveal the existence of a broad range in the abundances of these elements, and a comparison with similar data for main-sequence stars enables insight into the evolutionary history of the cluster. The majority of the RGB stars were found to be depleted in carbon, i.e., [C/Fe] < 0, while [N/Fe] for the same stars shows a range of {approx}1 dex, from [N/Fe] {approx} 0.7 to 1.7 dex. The strontium-to-iron abundance ratios varied from solar to mildly enhanced (0.0 {<=} [Sr/Fe] {<=} 0.8), with [Ba/Fe] generally equal to or greater than [Sr/Fe]. The carbon and nitrogen abundance ratios for the one known CH star in the sample, ROA 279, are [C/Fe] = 0.6 and [N/Fe] = 0.5 dex. Evidence for evolutionary mixing on the RGB is found from the fact that the relative carbon abundances on the main sequence are generally higher than those on the RGB. However, comparison of the RGB and main-sequence samples shows that the upper level of nitrogen enhancement is similar in both sets at [N/Fe] {approx} 2.0 dex. This is most likely the result of primordial rather than evolutionary mixing processes. One RGB star, ROA 276, was found to have Sr and Ba abundance ratios similar to the anomalous Sr-rich main-sequence star S2015448. High-resolution spectra of ROA 276 were obtained with the Magellan Telescope/MIKE spectrograph combination to confirm this result, revealing that ROA 276 is indeed an unusual star. For this star, calculations of the depletion effect, the potential change in surface abundance that results from the increased depth of the convective envelope as a star moves from the main sequence to the RGB, strongly suggest that the observed Sr enhancement in ROA 276 is of primordial origin, rather than originating from a surface accretion event.

  9. Microsoft Word - cmo etalKyotoA4.doc

    Office of Scientific and Technical Information (OSTI)

    MIXING OF CO 2 AND CH 4 IN GAS RESERVOIRS: CODE COMPARISON STUDIES C.M. Oldenburg 1 , D.H.-S. Law 2 , Y. Le Gallo 3 , S.P. White 4 1 Earth Sciences Division 90-1116, Lawrence Berkeley National Laboratory Berkeley, CA 94720 USA 2 Alberta Research Council, Heavy Oil and Oil Sands, 250 Karl Clark Road, Edmonton, Alberta, Canada 3 Institut Français du Pétrole, 174 Avenue de Bois Préau, 92852 Rueil Malmaison Cédex, France 4 Industrial Research Ltd., P.O. Box 31310, Lower Hutt, New Zealand

  10. Accurate atmospheric parameters at moderate resolution using spectral indices: Preliminary application to the marvels survey

    SciTech Connect (OSTI)

    Ghezzi, Luan; Da Costa, Luiz N.; Maia, Marcio A. G.; Ogando, Ricardo L. C.; Dutra-Ferreira, Letcia; Lorenzo-Oliveira, Diego; Porto de Mello, Gustavo F.; Santiago, Baslio X.; De Lee, Nathan; Lee, Brian L.; Ge, Jian; Wisniewski, John P.; Gonzlez Hernndez, Jonay I.; Stassun, Keivan G.; Cargile, Phillip; Pepper, Joshua; Fleming, Scott W.; Schneider, Donald P.; Mahadevan, Suvrath; Wang, Ji; and others

    2014-12-01

    Studies of Galactic chemical, and dynamical evolution in the solar neighborhood depend on the availability of precise atmospheric parameters (effective temperature T {sub eff}, metallicity [Fe/H], and surface gravity log g) for solar-type stars. Many large-scale spectroscopic surveys operate at low to moderate spectral resolution for efficiency in observing large samples, which makes the stellar characterization difficult due to the high degree of blending of spectral features. Therefore, most surveys employ spectral synthesis, which is a powerful technique, but relies heavily on the completeness and accuracy of atomic line databases and can yield possibly correlated atmospheric parameters. In this work, we use an alternative method based on spectral indices to determine the atmospheric parameters of a sample of nearby FGK dwarfs and subgiants observed by the MARVELS survey at moderate resolving power (R ? 12,000). To avoid a time-consuming manual analysis, we have developed three codes to automatically normalize the observed spectra, measure the equivalent widths of the indices, and, through a comparison of those with values calculated with predetermined calibrations, estimate the atmospheric parameters of the stars. The calibrations were derived using a sample of 309 stars with precise stellar parameters obtained from the analysis of high-resolution FEROS spectra, permitting the low-resolution equivalent widths to be directly related to the stellar parameters. A validation test of the method was conducted with a sample of 30 MARVELS targets that also have reliable atmospheric parameters derived from the high-resolution spectra and spectroscopic analysis based on the excitation and ionization equilibria method. Our approach was able to recover the parameters within 80 K for T {sub eff}, 0.05 dex for [Fe/H], and 0.15 dex for log g, values that are lower than or equal to the typical external uncertainties found between different high-resolution analyses. An additional test was performed with a subsample of 138 stars from the ELODIE stellar library, and the literature atmospheric parameters were recovered within 125 K for T {sub eff}, 0.10 dex for [Fe/H], and 0.29 dex for log g. These precisions are consistent with or better than those provided by the pipelines of surveys operating with similar resolutions. These results show that the spectral indices are a competitive tool to characterize stars with intermediate resolution spectra.

  11. Characterizing the AB Doradus moving group via high-resolution spectroscopy and kinematic traceback

    SciTech Connect (OSTI)

    McCarthy, Kyle; Wilhelm, Ronald J.

    2014-10-01

    We present a detailed analysis of 10 proposed F and G members of the nearby, young moving group AB Doradus (ABD). Our sample was obtained using the 2.7 m telescope at the McDonald Observatory with the coude echelle spectrograph, achieving R ? 60,000 and signal-to-noise ratio ?200. We derive spectroscopic T {sub eff}, log(g), [Fe/H], and microturbulance (v{sub t} ) using a bootstrap method of the TGVIT software resulting in typical errors of 33K in T {sub eff}, 0.08 dex in log(g), 0.03 dex in [Fe/H], and 0.13 km s{sup 1} in v{sub t} . Characterization of the ABD sample is performed in three ways: (1) chemical homogeneity, (2) kinematic traceback, and (3) isochrone fitting. We find the average metal abundance is [M/H] = 0.03 0.06 with a traceback age of 125 Myr. Our stars were fit to three different evolutionary models and we found that the best match to our ABD sample is the YREC [M/H] = 0.1 model. In our sample of 10 stars, we identify 1 star that is a probable non-member, 3 enigmatic stars, and 6 stars with confirmed membership. We also present a list of chemically coherent stars from this study and the Barenfeld et al. study.

  12. HUNTING THE PARENT OF THE ORPHAN STREAM: IDENTIFYING STREAM MEMBERS FROM LOW-RESOLUTION SPECTROSCOPY

    SciTech Connect (OSTI)

    Casey, Andrew R.; Da Costa, Gary; Keller, Stefan C.; Maunder, Elizabeth

    2013-02-10

    We present candidate K-giant members in the Orphan Stream that have been identified from low-resolution data taken with the AAOmega spectrograph on the Anglo-Australian Telescope. From modest signal-to-noise spectra and independent cuts in photometry, kinematics, gravity, and metallicity we yield self-consistent, highly probable stream members. We find a revised stream distance of 22.5 {+-} 2.0 kpc near the celestial equator and our kinematic signature peaks at V {sub GSR} = 82.1 {+-} 1.4 km s{sup -1}. The observed velocity dispersion of our most probable members is consistent with arising from the velocity uncertainties alone. This indicates that at least along this line of sight, the Orphan Stream is kinematically cold. Our data indicate an overall stream metallicity of [Fe/H] = -1.63 {+-} 0.19 dex which is more metal-rich than previously found and unbiased by spectral type. Furthermore, the significant metallicity dispersion displayed by our most probable members, {sigma}([Fe/H]) = 0.56 dex, suggests that the unidentified Orphan Stream parent is a dSph satellite. We highlight likely members for high-resolution spectroscopic follow-up.

  13. The Milky Way Tomography with SDSS. 2. Stellar Metallicity

    SciTech Connect (OSTI)

    Ivezic, Zeljko; Sesar, Branimir; Juric, Mario; Bond, Nicholas; Dalcanton, Julianne; Rockosi, Constance M.; Yanny, Brian; Newberg, Heidi J.; Beers, Timothy C.; Prieto, Carlos Allende; Wilhelm, Ron; /Texas Tech. /Michigan State U.

    2008-04-01

    In addition to optical photometry of unprecedented quality, the Sloan Digital Sky Survey (SDSS) is producing a massive spectroscopic database which already contains over 280,000 stellar spectra. Using effective temperature and metallicity derived from SDSS spectra for {approx}60,000 F and G type main sequence stars (0.2 < g-r < 0.6), we develop polynomial models, reminiscent of traditional methods based on the UBV photometry, for estimating these parameters from the SDSS u-g and g-r colors. These estimators reproduce SDSS spectroscopic parameters with a root-mean-square scatter of 100 K for effective temperature, and 0.2 dex for metallicity (limited by photometric errors), which are similar to random and systematic uncertainties in spectroscopic determinations. We apply this method to a photometric catalog of coadded SDSS observations and study the photometric metallicity distribution of {approx}200,000 F and G type stars observed in 300 deg{sup 2} of high Galactic latitude sky. These deeper (g < 20.5) and photometrically precise ({approx}0.01 mag) coadded data enable an accurate measurement of the unbiased metallicity distribution for a complete volume-limited sample of stars at distances between 500 pc and 8 kpc. The metallicity distribution can be exquisitely modeled using two components with a spatially varying number ratio, that correspond to disk and halo. The best-fit number ratio of the two components is consistent with that implied by the decomposition of stellar counts profiles into exponential disk and power-law halo components by Juric et al. (2008). The two components also possess the kinematics expected for disk and halo stars. The metallicity of the halo component can be modeled as a spatially invariant Gaussian distribution with a mean of [Fe/H] = -1.46 and a standard deviation of {approx}0.3 dex. The disk metallicity distribution is non-Gaussian, with a remarkably small scatter (rms {approx}0.16 dex) and the median smoothly decreasing with distance from the plane from -0.6 at 500 pc to -0.8 beyond several kpc. Similarly, we find using proper motion measurements that a non-Gaussian rotational velocity distribution of disk stars shifts by {approx}50 km/s as the distance from the plane increases from 500 pc to several kpc. Despite this similarity, the metallicity and rotational velocity distributions of disk stars are not correlated (Kendall's {tau} = 0.017 {+-} 0.018). This absence of a correlation between metallicity and kinematics for disk stars is in a conflict with the traditional decomposition in terms of thin and thick disks, which predicts a strong correlation ({tau} = ?0.30 {+-} 0.04) at {approx}1 kpc from the mid-plane. Instead, the variation of the metallicity and rotational velocity distributions can be modeled using non-Gaussian functions that retain their shapes and only shift as the distance from the mid-plane increases. We also study the metallicity distribution using a shallower (g < 19.5) but much larger sample of close to three million stars in 8500 sq. deg. of sky included in SDSS Data Release 6. The large sky coverage enables the detection of coherent substructures in the kinematics-metallicity space, such as the Monoceros stream, which rotates faster than the LSR, and has a median metallicity of [Fe/H] = ?0.95, with an rms scatter of only {approx}0.15 dex. We extrapolate our results to the performance expected from the Large Synoptic Survey Telescope (LSST) and estimate that the LSST will obtain metallicity measurements accurate to 0.2 dex or better, with proper motion measurements accurate to {approx}0.2-0.5 mas/yr, for about 200 million F/G dwarf stars within a distance limit of {approx}100 kpc (g < 23.5).

  14. The progenitors of local ultra-massive galaxies across cosmic time: from dusty star-bursting to quiescent stellar populations

    SciTech Connect (OSTI)

    Marchesini, Danilo; Marsan, Cemile Z.; Muzzin, Adam; Franx, Marijn; Stefanon, Mauro; Brammer, Gabriel G.; Vulcani, Benedetta; Fynbo, J. P. U.; Milvang-Jensen, Bo; Dunlop, James S.; Buitrago, Fernando

    2014-10-10

    Using the UltraVISTA catalogs, we investigate the evolution in the 11.4 Gyr since z = 3 of the progenitors of local ultra-massive galaxies (log (M {sub star}/M {sub ?}) ? 11.8; UMGs), providing a complete and consistent picture of how the most massive galaxies at z = 0 have assembled. By selecting the progenitors with a semi-empirical approach using abundance matching, we infer a growth in stellar mass of 0.56{sub ?0.25}{sup +0.35} dex, 0.45{sub ?0.20}{sup +0.16} dex, and 0.27{sub ?0.12}{sup +0.08} dex from z = 3, z = 2, and z = 1, respectively, to z = 0. At z < 1, the progenitors of UMGs constitute a homogeneous population of only quiescent galaxies with old stellar populations. At z > 1, the contribution from star-forming galaxies progressively increases, with the progenitors at 2 < z < 3 being dominated by massive (M {sub star} ? 2 10{sup 11} M {sub ?}), dusty (A {sub V} ? 1-2.2 mag), star-forming (SFR ? 100-400 M {sub ?} yr{sup 1}) galaxies with a large range in stellar ages. At z = 2.75, ?15% of the progenitors are quiescent, with properties typical of post-starburst galaxies with little dust extinction and strong Balmer break, and showing a large scatter in color. Our findings indicate that at least half of the stellar content of local UMGs was assembled at z > 1, whereas the remaining was assembled via merging from z ? 1 to the present. Most of the quenching of the star-forming progenitors happened between z = 2.75 and z = 1.25, in good agreement with the typical formation redshift and scatter in age of z = 0 UMGs as derived from their fossil records. The progenitors of local UMGs, including the star-forming ones, never lived on the blue cloud since z = 3. We propose an alternative path for the formation of local UMGs that refines previously proposed pictures and that is fully consistent with our findings.

  15. TWO DISTANT HALO VELOCITY GROUPS DISCOVERED BY THE PALOMAR TRANSIENT FACTORY

    SciTech Connect (OSTI)

    Sesar, Branimir; Cohen, Judith G.; Levitan, David; Kirby, Evan N.; Kulkarni, Shrinivas R.; Prince, Thomas A.; Grillmair, Carl J.; Laher, Russ R.; Surace, Jason A.; Juric, Mario; Ofek, Eran O.

    2012-08-20

    We report the discovery of two new halo velocity groups (Cancer groups A and B) traced by eight distant RR Lyrae stars and observed by the Palomar Transient Factory survey at R.A. {approx} 129 Degree-Sign , decl. {approx} 20 Degree-Sign (l {approx} 205 Degree-Sign , b {approx} 32 Degree-Sign ). Located at 92 kpc from the Galactic center (86 kpc from the Sun), these are some of the most distant substructures in the Galactic halo known to date. Follow-up spectroscopic observations with the Palomar Observatory 5.1 m Hale telescope and W. M. Keck Observatory 10 m Keck I telescope indicate that the two groups are moving away from the Galaxy at v-bar{sub gsr}{sup A} = 78.0{+-}5.6 km s{sup -1} (Cancer group A) and v-bar{sub gsr}{sup B} = 16.3{+-}7.1 km s{sup -1} (Cancer group B). The groups have velocity dispersions of {sigma}{sub v{sub g{sub s{sub r}{sup A}}}} = 12.4{+-}5.0 km s{sup -1} and {sigma}B{sub v{sub g{sub s{sub r}{sup B}}}} =14.9{+-}6.2 km s{sup -1} and are spatially extended (about several kpc), making it very unlikely that they are bound systems, and more likely to be debris of tidally disrupted dwarf galaxies or globular clusters. Both groups are metal-poor (median metallicities of [Fe/H]{sup A} = -1.6 dex and [Fe/H]{sup B} = -2.1 dex) and have a somewhat uncertain (due to small sample size) metallicity dispersion of {approx}0.4 dex, suggesting dwarf galaxies as progenitors. Two additional RR Lyrae stars with velocities consistent with those of the Cancer groups have been observed {approx}25 Degree-Sign east, suggesting possible extension of the groups in that direction.

  16. THE STELLAR-TO-HALO MASS RELATION OF LOCAL GALAXIES SEGREGATES BY COLOR

    SciTech Connect (OSTI)

    Rodrguez-Puebla, Aldo; Yang, Xiaohu; Foucaud, Sebastien; Jing, Y. P.; Avila-Reese, Vladimir; Drory, Niv

    2015-02-01

    By means of a statistical approach that combines different semi-empirical methods of galaxy-halo connection, we derive the stellar-to-halo mass relations (SHMR) of local blue and red central galaxies. We also constrain the fraction of halos hosting blue/red central galaxies and the occupation statistics of blue and red satellites as a function of halo mass, M {sub h}. For the observational input we use the blue and red central/satellite galaxy stellar mass functions and two-point correlation functions in the stellar mass range of 9 < log(M {sub *}/M {sub ?})<12. We find that: (1)the SHMR of central galaxies is segregated by color, with blue centrals having a SHMR above that of red centrals; at log(M {sub h}/M {sub ?}) ?12, the M {sub *}-to-M {sub h} ratio of the blue centrals is ?0.05, which is ?1.7times larger than the value of red centrals. (2) The constrained scatters around the SHMRs of red and blue centrals are ?0.14 and ?0.11dex, respectively. The scatter of the average SHMR of all central galaxies changes from ?0.20dex to ?0.14dex in the 11.3 < log(M {sub h}/M {sub ?})<15 range. (3) The fraction of halos hosting blue centrals at M{sub h}=10{sup 11} M {sub ?} is 87%, but at 2 10{sup 12} M {sub ?} decays to ?20%, approaching a few percent at higher masses. The characteristic mass at which this fraction is the same for blue and red galaxies is M{sub h}?710{sup 11} M {sub ?}. Our results suggest that the SHMR of central galaxies at large masses is shaped by mass quenching. At low masses processes that delay star formation without invoking too strong supernova-driven outflows could explain the high M {sub *}-to-M {sub h} ratios of blue centrals as compared to those of the scarce red centrals.

  17. A PRELIMINARY CALIBRATION OF THE RR LYRAE PERIOD-LUMINOSITY RELATION AT MID-INFRARED WAVELENGTHS: WISE DATA

    SciTech Connect (OSTI)

    Madore, Barry F.; Freedman, Wendy L.; Kollmeier, Juna A.; Monson, Andy; Eric Persson, S.; Rich, Jeff A. Jr.; Scowcroft, Victoria; Seibert, Mark; Hoffman, Douglas E-mail: wendy@obs.carnegiescience.edu E-mail: amonson@obs.carnegiescience.edu E-mail: jrich@obs.carnegiescience.edu E-mail: mseibert@obs.carnegiescience.edu

    2013-10-20

    Using time-resolved, mid-infrared data from the Wide-field Infrared Survey Explorer (WISE) and geometric parallaxes from the Hubble Space Telescope for four Galactic RR Lyrae variables, we derive the following Population II period-luminosity (PL) relations for the WISE [W1], [W2], and [W3] bands at 3.4, 4.6, and 12 ?m, respectively: The slopes and the scatter around the fits are consistent with a smooth extrapolation of those same quantities from previously published K-band observations at 2.2 ?m, where the asymptotic (long-wavelength) behavior is consistent with a period-radius relation with a slope of 0.5. No obvious correlation with metallicity (spanning 0.4 dex in [Fe/H]) is found in the residuals of the four calibrating RR Lyrae stars about the mean PL regression line.

  18. The Carina project. VII. Toward the breaking of the age-metallicity degeneracy of red giant branch stars using the C {sub U,} {sub B,} {sub I} index

    SciTech Connect (OSTI)

    Monelli, M.; Milone, A. P.; Gallart, C.; Aparicio, A. [Instituto de Astrofsica de Canarias, Calle Via Lactea s/n, E-38205 La Laguna, Tenerife (Spain); Fabrizio, M.; Cassisi, S.; Buonanno, R. [Istituto Nazionale di Astrofisica-Osservatorio Astronomico Collurania, Via M. Maggini, I-64100 Teramo (Italy); Bono, G. [Dipartimento di Fisica, Universit di Roma Tor Vergata, Via della Ricerca Scientifica 1, I-00133 Rome (Italy); Stetson, P. B. [Dominion Astrophysical Observatory, NRC-Herzberg, 5071 West Saanich Road, Victoria, BC, V9E 2E7 (Canada); Walker, A. R. [Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, Casilla 603, La Serena (Chile); Nonino, M. [Istituto Nazionale di Astrofisica-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, I-40131 Trieste (Italy); Dall'Ora, M. [INAFOsservatorio Astronomico di Capodimonte, Salita Moiariello 16, I-80131 Napoli (Italy); Ferraro, I.; Iannicola, G.; Pulone, L. [Istituto Nazionale di Astrofisica-Osservatorio Astronomico di Roma, Via Frascati 33, Monte Porzio Catone, I-00044 Rome (Italy); Thvenin, F., E-mail: monelli@iac.es [Universit de Nice Sophia-antipolis, CNRS, Observatoire de la Cte d'Azur, Laboratoire Lagrange, BP 4229, F-06304 Nice (France)

    2014-12-01

    We present an analysis of photometric and spectroscopic data of the Carina dSph galaxy, testing a new approach similar to that used to disentangle multiple populations in Galactic globular clusters (GCs). We show that a proper color combination is able to separate a significant fraction of the red giant branch (RGB) of the two main Carina populations (the old one, ?12 Gyr, and the intermediate-age one, 4-8 Gyr). In particular, the c {sub U,} {sub B,} {sub I} = (U B) (B I) pseudo-color allows us to follow the RGB of both populations along a relevant portion of the RGB. We find that the oldest stars have a more negative c {sub U,} {sub B,} {sub I} pseudo-color than intermediate-age ones. We correlate the pseudo-color of RGB stars with their chemical properties, finding a significant trend between the iron content and the c {sub U,} {sub B,} {sub I}. Stars belonging to the old population are systematically more metal-poor ([Fe/H] =2.32 0.08 dex) than the intermediate-age ones ([Fe/H] =1.82 0.03 dex). This gives solid evidence of the chemical evolution history of this galaxy, and we have a new diagnostic that can allow us to break the age-metallicity degeneracy of H-burning advanced evolutionary phases. We compared the distribution of stars in the c {sub U,} {sub B,} {sub I} plane with theoretical isochrones, finding that no satisfactory agreement can be reached with models developed in a theoretical framework based on standard heavy element distributions. Finally, we discuss possible systematic differences when compared with multiple populations in GCs.

  19. The chemical abundances of the Ap star HD94660

    SciTech Connect (OSTI)

    Giarrusso, M. [Universit di Catania, Dipartimento di Fisica e Astronomia, Sezione Astrofisica, Via S. Sofia 78, 95123 Catania (Italy); INAF - Osservatorio Astrofisico di Catania, via S. Sofia 78, 95123 Catania (Italy); INFN - Laboratori Nazionali del Sud (Italy)

    2014-05-09

    In this work I present the determination of chemical abundances of the Ap star HD94660, a possible rapid oscillating star. As all the magnetic chemically peculiar objects, it presents CNO underabundance and overabundance of iron peak elements of ?100 times and of rare earths up to 4 dex with respect to the Sun. The determination was based on the conversion of the observed equivalent widths into abundances simultaneously to the determination of effective temperature and gravity. Since the Balmer lines of early type stars are very sensitive to the surface gravity while the flux distribution is sensitive to the effective temperature, I have adopted an iterative procedure to match the H{sub ?} line profile and the observed UV-Vis-NIR magnitudes of HD94660 looking for a consistency between the metallicity of the atmosphere model and the derived abundances. From my spectroscopic analysis, this star belongs to the no-rapid oscillating class.

  20. A chemical confirmation of the faint Boötes II dwarf spheroidal galaxy

    SciTech Connect (OSTI)

    Koch, Andreas; Rich, R. Michael

    2014-10-10

    We present a chemical abundance study of the brightest confirmed member star of the ultra-faint dwarf galaxy Boötes II from Keck/HIRES high-resolution spectroscopy at moderate signal-to-noise ratios. At [Fe/H] = –2.93 ± 0.03(stat.) ± 0.17(sys.), this star chemically resembles metal-poor halo field stars and the signatures of other faint dwarf spheroidal galaxies at the same metallicities in that it shows enhanced [α/Fe] ratios, Solar Fe-peak element abundances, and low upper limits on the neutron-capture element Ba. Moreover, this star shows no chemical peculiarities in any of the eight elements we were able to measure. This implies that the chemical outliers found in other systems remain outliers pertaining to the unusual enrichment histories of the respective environments, while Boo II appears to have experienced an enrichment history typical of its very low mass. We also re-calibrated previous measurements of the galaxy's metallicity from the calcium triplet (CaT) and find a much lower value than reported before. The resulting broad metallicity spread, in excess of one dex, the very metal-poor mean, and the chemical abundance patterns of the present star imply that Boötes II is a low-mass, old, metal-poor dwarf galaxy and not an overdensity associated with the Sagittarius Stream as has been previously suggested based on its sky position and kinematics. The low, mean CaT metallicity of –2.7 dex falls right on the luminosity-metallicity relation delineated over four orders of magnitude from the more luminous to the faintest galaxies. Thus Boötes II's chemical enrichment appears representative of the galaxy's original mass, while tidal stripping and other mass loss mechanisms were probably not significant as for other low-mass satellites.

  1. A NEW SYNTHETIC LIBRARY OF THE NEAR-INFRARED Ca II TRIPLET INDICES. I. INDEX DEFINITION, CALIBRATION, AND RELATIONS WITH STELLAR ATMOSPHERIC PARAMETERS

    SciTech Connect (OSTI)

    Du, W.; Luo, A. L.; Zhao, Y. H. E-mail: lal@nao.cas.cn

    2012-02-15

    Adopting the SPECTRUM package, which is a stellar spectral synthesis program, we have synthesized a comprehensive set of 2890 near-infrared (NIR) synthetic spectra with a resolution and wavelength sampling similar to the Sloan Digital Sky Survey (SDSS) and the forthcoming Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) spectra. During the synthesis, we applied the 'New grids of ATLAS9 Model Atmosphere' to develop a grid of local thermodynamic equilibrium model atmospheres for effective temperatures (T{sub eff}) ranging from 3500 to 7500 K, for surface gravities (log g) from 0.5 to 5.0 dex, for metallicities ([Fe/H]) from -4.0 to 0.5 dex, and for solar ([{alpha}/Fe] = 0.0 dex) and non-solar ([{alpha}/Fe] = +0.4 dex) abundances. This synthetic stellar library is composed of 1350 solar scaled abundance (SSA) and 1530 non-solar scaled abundance (NSSA) spectra, grounding on which we have defined a new set of NIR Ca II triplet indices and an index CaT as the sum of the three. These defined indices were automatically measured on every spectrum of the synthetic stellar library and calibrated with the indices computed on the observational spectra from the INDO-U.S. stellar library. In order to check the effect of {alpha}-element enhancement on the so-defined Ca II indices, we compared indices measured on the SSA spectra with those on the NSSA ones at the same trine of stellar parameters (T{sub eff}, log g, [Fe/H]); luckily, little influences of {alpha}-element enhancement were found. Furthermore, comparisons of our synthetic indices with the observational ones from measurements on the INDO-U.S. stellar library, the SDSS-DR7 and SDSS-DR8 spectroscopic survey are presented, respectively, for dwarfs and giants in specific. For dwarfs, our synthetic indices could well reproduce the behaviors of the observational indices versus stellar parameters, which verifies the validity of our index definitions for dwarfs. For giants, the consistency between our synthetic indices and the observational ones does not appear to be as good. However, a new synthetic library of NIR Ca II indices has been founded for deeper studies on the NIR wave band of stellar spectra, and this library is particularly appropriate for the SDSS and the forthcoming LAMOST stellar spectra. We have regressed the strength of the CaT index as a function of stellar parameters for both dwarfs and giants after a series of experimental investigations into relations of the indices with stellar parameters. For dwarfs, log g has little effect on the indices, while [Fe/H] and T{sub eff} play a role together. The leading factor is probably [Fe/H], which changes the strength of the indices by a positive trend. For giants, log g starts to influence the strength of the indices by a negative trend for the metal-poor, and even impact deeply for the metal-rich; besides, [Fe/H] and T{sub eff} still matter. In addition, we briefly discussed the major differences between our Ca II triplet indices and the CaHK doublet indices. Ultimately, a supplemental experiment was carried out to show that spectral noises do have effects on our set of NIR Ca II indices. However, the influence is not weak enough to be ignored if the signal-to-noise ratio falls below 20.

  2. HIGH PRECISION ABUNDANCES OF THE OLD SOLAR TWIN HIP 102152: INSIGHTS ON Li DEPLETION FROM THE OLDEST SUN

    SciTech Connect (OSTI)

    Monroe, TalaWanda R.; Melendez, Jorge; Tucci Maia, Marcelo; Freitas, Fabricio C.; Yong, David; Asplund, Martin; Alves-Brito, Alan; Casagrande, Luca; Bergemann, Maria; Bedell, Megan; Bean, Jacob; Lind, Karin; Castro, Matthieu; Do Nascimento, Jose-Dias; Bazot, Michael

    2013-09-10

    We present the first detailed chemical abundance analysis of the old 8.2 Gyr solar twin, HIP 102152. We derive differential abundances of 21 elements relative to the Sun with precisions as high as 0.004 dex ({approx}<1%), using ultra high-resolution (R = 110,000), high S/N UVES spectra obtained on the 8.2 m Very Large Telescope. Our determined metallicity of HIP 102152 is [Fe/H] = -0.013 {+-} 0.004. The atmospheric parameters of the star were determined to be 54 K cooler than the Sun, 0.09 dex lower in surface gravity, and a microturbulence identical to our derived solar value. Elemental abundance ratios examined versus dust condensation temperature reveal a solar abundance pattern for this star, in contrast to most solar twins. The abundance pattern of HIP 102152 appears to be the most similar to solar of any known solar twin. Abundances of the younger, 2.9 Gyr solar twin, 18 Sco, were also determined from UVES spectra to serve as a comparison for HIP 102152. The solar chemical pattern of HIP 102152 makes it a potential candidate to host terrestrial planets, which is reinforced by the lack of giant planets in its terrestrial planet region. The following non-local thermodynamic equilibrium Li abundances were obtained for HIP 102152, 18 Sco, and the Sun: log {epsilon} (Li) = 0.48 {+-} 0.07, 1.62 {+-} 0.02, and 1.07 {+-} 0.02, respectively. The Li abundance of HIP 102152 is the lowest reported to date for a solar twin, and allows us to consider an emerging, tightly constrained Li-age trend for solar twin stars.

  3. A NEW CEPHEID DISTANCE TO THE GIANT SPIRAL M101 BASED ON IMAGE SUBTRACTION OF HUBBLE SPACE TELESCOPE/ADVANCED CAMERA FOR SURVEYS OBSERVATIONS

    SciTech Connect (OSTI)

    Shappee, Benjamin J.; Stanek, K. Z. E-mail: kstanek@astronomy.ohio-state.edu

    2011-06-01

    We accurately determine a new Cepheid distance to M101 (NGC 5457) using archival Hubble Space Telescope (HST)/Advanced Camera for Surveys V and I time series photometry of two fields within the galaxy. We make a slight modification to the ISIS image subtraction package to obtain optimal differential light curves from HST data. We discovered 827 Cepheids with periods between 3 and 80 days, the largest extragalactic sample of Cepheids observed with HST by a factor of two. With this large Cepheid sample, we find that the relative distance of M101 from the Large Magellanic Cloud is {Delta}{mu}{sub LMC} = 10.63 {+-} 0.04 (random) {+-} 0.06 (systematic) mag. If we use the geometrically determined maser distance to NGC 4258 as our distance anchor, the distance modulus of M101 is {mu}{sub 0} = 29.04 {+-} 0.05 (random) {+-} 0.18 (systematic) mag or D = 6.4 {+-} 0.2 (random) {+-} 0.5 (systematic) Mpc. The uncertainty is dominated by the maser distance estimate ({+-}0.15 mag), which should improve over the next few years. We determine a steep metallicity dependence, {gamma}, for our Cepheid sample through two methods, yielding {gamma} = -0.80 {+-} 0.21 (random) {+-} 0.06 (systematic) mag dex{sup -1} and {gamma} = -0.72{sup +0.22}{sub -0.25} (random) {+-} 0.06 (systematic) mag dex{sup -1}. We see marginal evidence for variations in the Wesenheit period-luminosity relation slope as a function of deprojected galactocentric radius. We also use the tip of the red giant branch method to independently determine the distance modulus to M101 of {mu}{sub 0} = 29.05 {+-} 0.06 (random) {+-} 0.12 (systematic) mag.

  4. COSMIC ORIGINS SPECTROGRAPH OBSERVATIONS OF WARM INTERVENING GAS AT z {approx} 0.325 TOWARD 3C 263

    SciTech Connect (OSTI)

    Narayanan, Anand [Indian Institute of Space Science and Technology, Thiruvananthapuram 695547, Kerala (India); Savage, Blair D.; Wakker, Bart P., E-mail: anand@iist.ac.in, E-mail: savage@astro.wisc.edu, E-mail: wakker@astro.wisc.edu [Department of Astronomy, University of Wisconsin-Madison, 5534 Sterling Hall, 475 N. Charter Street, Madison, WI 53706-1582 (United States)

    2012-06-10

    We present HST/COS high-S/N observations of the z = 0.32566 multiphase absorber toward 3C 263. The Cosmic Origins Spectrograph (COS) data show absorption from H I (Ly{alpha} to Ly{theta}), O VI, C III, N III, Si III, and C II. The Ne VIII in this absorber is detected in the FUSE spectrum along with O III, O IV, and N IV. The low and intermediate ions are kinematically aligned with each other and H I and display narrow line widths of b {approx} 6-8 km s{sup -1}. The O VI {lambda}{lambda}1031, 1037 lines are kinematically offset by {Delta}v {approx} 12 km s{sup -1} from the low ions and are a factor of {approx}4 broader. All metal ions except O VI and Ne VIII are consistent with an origin in gas photoionized by the extragalactic background radiation. The bulk of the observed H I is also traced by this photoionized medium. The metallicity in this gas phase is Z {approx}> 0.15 Z{sub Sun} with carbon having near-solar abundances. The O VI and Ne VIII favor an origin in collisionally ionized gas at T = 5.2 Multiplication-Sign 10{sup 5} K. The H I absorption associated with this warm absorber is a broad-Ly{alpha} absorber (BLA) marginally detected in the COS spectrum. This warm gas phase has a metallicity of [X/H] {approx}-0.12 dex, and a total hydrogen column density of N( H) {approx} 3 Multiplication-Sign 10{sup 19} cm{sup -2}, which is {approx}2 dex higher than what is traced by the photoionized gas. Simultaneous detection of O VI, Ne VIII, and BLAs in an absorber can be a strong diagnostic of gas with T {approx} 10{sup 5}-10{sup 6} K corresponding to the warm phase of the warm-hot intergalactic medium or shock-heated gas in the extended halos of galaxies.

  5. Star formation and black hole growth at z ? 4.8

    SciTech Connect (OSTI)

    Netzer, Hagai; Mor, Rivay; Trakhtenbrot, Benny; Shemmer, Ohad; Lira, Paulina

    2014-08-10

    We report Herschel/SPIRE, Spitzer and Wide-field Infrared Survey Explorer observations of 44 z ? 4.8 optically selected active galactic nuclei (AGNs). This flux-limited sample contains the highest mass black holes (BHs) at this redshift. Ten of the objects were detected by Herschel and five show emission that is not clearly associated with the AGNs. The star formation (SF) luminosity (L{sub SF}) obtained by fitting the spectral energy distribution (SED) with standard SF templates, taking into account AGN contribution, is in the range 10{sup 46.62}-10{sup 47.21} erg s{sup 1} corresponding to SF rates of 1090-4240 M{sub ?} yr{sup 1}. Fitting with very luminous submillimeter galaxy SEDs gives SF rates that are smaller by 0.05 dex when using all bands and 0.1 dex when ignoring the 250 ?m band. A 40 K graybody fits to only the 500 ?m fluxes reduce L{sub SF} by about a factor of two. A stacking analysis of 29 undetected sources gives significant signals in all three bands. A SF template fit indicates L{sub SF} = 10{sup 46.19-46.23} erg s{sup 1} depending on the assumed AGN contribution. A 40 K fit to the stacked 500 ?m flux gives L{sub SF} = 10{sup 45.95} erg s{sup 1}. The mean BH mass (M{sub BH}) and AGN luminosity (L{sub AGN}) of the detected sources are significantly higher than those of the undetected ones. The spectral differences are seen all the way from UV to far infrared wavelengths. The mean optical-UV spectra are similar to those predicted for thin accretion disks around BHs with similar masses and accretion rates. We suggest two alternative explanations to the correlation of L{sub SF}, L{sub AGN} and M{sub BH}, one involving no AGN feedback and the second involving moderate feedback that affects, but does not totally quench, SF in three-quarters of the sources. We compare our L{sub SF} and L{sub AGN} to lower redshift samples and show a new correlation between L{sub SF} and M{sub BH}. We also examine several rather speculative ideas about the host galaxy properties including the possibility that the detected sources are above the SF mass sequence (MS) at z ? 4.8, perhaps in mergers, and most of the undetected sources are on the MS.

  6. KILOPARSEC-SCALE PROPERTIES OF EMISSION-LINE GALAXIES

    SciTech Connect (OSTI)

    Hemmati, Shoubaneh; Miller, Sarah H.; Mobasher, Bahram; Nayyeri, Hooshang; Ferguson, Henry C.; Koekemoer, Anton M.; Guo, Yicheng; Koo, David C.

    2014-12-20

    We perform a detailed study of the resolved properties of emission-line galaxies at kiloparsec scales to investigate how small-scale and global properties of galaxies are related. We use a sample of 119 galaxies in the GOODS fields. The galaxies are selected to cover a wide range in morphologies over the redshift range 0.2 < z < 1.3. High resolution spectroscopic data from Keck/DEIMOS observations are used to fix the redshift of all the galaxies in our sample. Using the HST/ACS and HST/WFC3 imaging data taken as a part of the CANDELS project, for each galaxy, we perform spectral energy distribution fitting per resolution element, producing resolved rest-frame UV color, stellar mass, star formation rate (SFR), age, and extinction maps. We develop a technique to identify ''regions'' of statistical significance within individual galaxies, using their rest-frame color maps to select red and blue regions, a broader definition for what are called ''clumps'' in other works. As expected, for any given galaxy, the red regions are found to have higher stellar mass surface densities and older ages compared to the blue regions. Furthermore, we quantify the spatial distribution of red and blue regions with respect to both redshift and stellar mass, finding that the stronger concentration of red regions toward the centers of galaxies is not a significant function of either redshift or stellar mass. We find that the ''main sequence'' of star-forming galaxies exists among both red and blue regions inside galaxies, with the median of blue regions forming a tighter relation with a slope of 1.1 0.1 and a scatter of ?0.2dex compared to red regions with a slope of 1.3 0.1 and a scatter of ?0.6dex. The blue regions show higher specific SFRs (sSFRs) than their red counterparts with the sSFR decreasing since z ? 1, driven primarily by the stellar mass surface densities rather than the SFRs at a given resolution element.

  7. M dwarf metallicities and giant planet occurrence: Ironing out uncertainties and systematics

    SciTech Connect (OSTI)

    Gaidos, Eric; Mann, Andrew W.

    2014-08-10

    Comparisons between the planet populations around solar-type stars and those orbiting M dwarfs shed light on the possible dependence of planet formation and evolution on stellar mass. However, such analyses must control for other factors, i.e., metallicity, a stellar parameter that strongly influences the occurrence of gas giant planets. We obtained infrared spectra of 121 M dwarfs stars monitored by the California Planet Search and determined metallicities with an accuracy of 0.08 dex. The mean and standard deviation of the sample are 0.05 and 0.20 dex, respectively. We parameterized the metallicity dependence of the occurrence of giant planets on orbits with a period less than two years around solar-type stars and applied this to our M dwarf sample to estimate the expected number of giant planets. The number of detected planets (3) is lower than the predicted number (6.4), but the difference is not very significant (12% probability of finding as many or fewer planets). The three M dwarf planet hosts are not especially metal rich and the most likely value of the power-law index relating planet occurrence to metallicity is 1.06 dex per dex for M dwarfs compared to 1.80 for solar-type stars; this difference, however, is comparable to uncertainties. Giant planet occurrence around both types of stars allows, but does not necessarily require, a mass dependence of ?1 dex per dex. The actual planet-mass-metallicity relation may be complex, and elucidating it will require larger surveys like those to be conducted by ground-based infrared spectrographs and the Gaia space astrometry mission.

  8. The abundance properties of nearby late-type galaxies. I. The data

    SciTech Connect (OSTI)

    Pilyugin, L. S.; Grebel, E. K.; Kniazev, A. Y. E-mail: grebel@ari.uni-heidelberg.de

    2014-06-01

    We investigate the oxygen and nitrogen abundance distributions across the optical disks of 130 nearby late-type galaxies using around 3740 published spectra of H II regions. We use these data in order to provide homogeneous abundance determinations for all objects in the sample, including H II regions in which not all of the usual diagnostic lines were measured. Examining the relation between N and O abundances in these galaxies we find that the abundances in their centers and at their isophotal R {sub 25} disk radii follow the same relation. The variation in N/H at a given O/H is around 0.3 dex. We suggest that the observed spread in N/H may be partly caused by the time delay between N and O enrichment and the different star formation histories in galaxies of different morphological types and dimensions. We study the correlations between the abundance properties (central O and N abundances, radial O and N gradients) of a galaxy and its morphological type and dimension.

  9. UAP56 is an important mediator of Angiotensin II/platelet derived growth factor induced vascular smooth muscle cell DNA synthesis and proliferation

    SciTech Connect (OSTI)

    Sahni, Abha; Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 ; Wang, Nadan; Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia, PA 19107 ; Alexis, Jeffrey

    2013-02-15

    Highlights: ► Knockdown of UAP56 inhibits Angiotensin II/PDGF induced vascular smooth muscle cell proliferation. ► UAP56 is a positive regulator of E2F transcriptional activation. ► UAP56 is present in the vessel wall of low flow carotid arteries. -- Abstract: Angiotensin (Ang) II and platelet-derived growth factor (PDGF) are important mediators of pathologic vascular smooth muscle cell (VSMC) proliferation. Identifying downstream mediators of Ang II and PDGF signaling may provide insights for therapies to improve vascular proliferative diseases. We have previously demonstrated that breakpoint cluster region (Bcr) is an important mediator of Ang II/PDGF signaling in VSMC. We have recently reported that the DExD/H box protein UAP56 is an interacting partner of Bcr in regulating VSMC DNA synthesis. We hypothesized that UAP56 itself is an important regulator of VSMC proliferation. In this report we demonstrate that knockdown of UAP56 inhibits Ang II/PDGF induced VSMC DNA synthesis and proliferation, and inhibits E2F transcriptional activity. In addition, we demonstrate that UAP56 is present in the vessel wall of low-flow carotid arteries. These findings suggest that UAP56 is a regulator of VSMC proliferation and identify UAP56 as a target for preventing vascular proliferative disease.

  10. Stellar metallicity of the extended disk and distance of the spiral galaxy NGC 3621

    SciTech Connect (OSTI)

    Kudritzki, Rolf-Peter; Bresolin, Fabio; Hosek, Matthew W. Jr.; Urbaneja, Miguel A.; Przybilla, Norbert E-mail: bresolin@ifa.hawaii.edu E-mail: Miguel.Urbaneja-Perez@uibk.ac.at

    2014-06-10

    Low resolution (?4.5 ) ESO VLT/FORS spectra of blue supergiant stars are analyzed to determine stellar metallicities (based on elements such as iron, titanium, and magnesium) in the extended disk of the spiral galaxy, NGC 3621. Mildly subsolar metallicity (0.30 dex) is found for the outer objects beyond 7 kpc, independent of galactocentric radius and compatible with the absence of a metallicity gradient, confirming the results of a recent investigation of interstellar medium H II region gas oxygen abundances. The stellar metallicities are slightly higher than those from the H II regions when based on measurements of the weak forbidden auroral oxygen line at 4363 but lower than the ones obtained with the R {sub 23} strong line method. It is shown that the present level of metallicity in the extended disk cannot be the result of chemical evolution over the age of the disk with the present rate of in situ star formation. Additional mechanisms must be involved. In addition to metallicity, stellar effective temperatures, gravities, interstellar reddening, and bolometric magnitudes are determined. After the application of individual reddening corrections for each target, the flux-weighted gravity-luminosity relationship of blue supergiant stars is used to obtain a distance modulus of 29.07 0.09 mag (distance D = 6.52 0.28 Mpc). This new distance is discussed in relation to Cepheid and the tip of the red giant branch distances.

  11. AN H-BAND SPECTROSCOPIC METALLICITY CALIBRATION FOR M DWARFS

    SciTech Connect (OSTI)

    Terrien, Ryan C.; Mahadevan, Suvrath; Bender, Chad F.; Deshpande, Rohit; Ramsey, Lawrence W.; Bochanski, John J., E-mail: rct151@psu.edu [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States)

    2012-03-10

    We present an empirical near-infrared (NIR) spectroscopic method for estimating M dwarf metallicities, based on features in the H band, as well as an implementation of a similar published method in the K band. We obtained R {approx} 2000 NIR spectra of a sample of M dwarfs using the NASA IRTF-SpeX spectrograph, including 22 M dwarf metallicity calibration targets that have FGK companions with known metallicities. The H-band and K-band calibrations provide equivalent fits to the metallicities of these binaries, with an accuracy of {+-}0.12 dex. We derive the first empirically calibrated spectroscopic metallicity estimate for the giant planet-hosting M dwarf GJ 317, confirming its supersolar metallicity. Combining this result with observations of eight other M dwarf planet hosts, we find that M dwarfs with giant planets are preferentially metal-rich compared to those that host less massive planets. Our H-band calibration relies on strongly metallicity-dependent features in the H band, which will be useful in compositional studies using mid- to high-resolution NIR M dwarf spectra, such as those produced by multiplexed surveys like SDSS-III APOGEE. These results will also be immediately useful for ongoing spectroscopic surveys of M dwarfs.

  12. Being WISE. I. Validating stellar population models and M {sub *}/L ratios at 3.4 and 4.6 μm

    SciTech Connect (OSTI)

    Norris, Mark A.; Meidt, Sharon; Van de Ven, Glenn; Schinnerer, Eva; Groves, Brent; Querejeta, Miguel

    2014-12-10

    Using data from the Wide-field Infrared Survey Explorer mission, we have measured near infra-red (NIR) photometry of a diverse sample of dust-free stellar systems (globular clusters, dwarf and giant early-type galaxies) which have metallicities that span the range -2.2 < [Fe/H] (dex) < 0.3. This dramatically increases the sample size and broadens the metallicity regime over which the 3.4 (W1) and 4.6 μm (W2) photometry of stellar populations have been examined. We find that the W1 – W2 colors of intermediate and old (>2 Gyr) stellar populations are insensitive to the age of the stellar population, but that the W1 – W2 colors become bluer with increasing metallicity, a trend not well reproduced by most stellar population synthesis (SPS) models. In common with previous studies, we attribute this behavior to the increasing strength of the CO absorption feature located in the 4.6 μm bandpass with metallicity. Having used our sample to validate the efficacy of some of the SPS models, we use these models to derive stellar mass-to-light ratios in the W1 and W2 bands. Utilizing observational data from the SAURON and ATLAS3D surveys, we demonstrate that these bands provide extremely simple, yet robust stellar mass tracers for dust free older stellar populations that are freed from many of the uncertainties common among optical estimators.

  13. WASP-19b: THE SHORTEST PERIOD TRANSITING EXOPLANET YET DISCOVERED

    SciTech Connect (OSTI)

    Hebb, L.; Collier-Cameron, A.; Enoch, B.; Horne, K.; Triaud, A.H.M.J.; Gillon, M.; Queloz, D.; Mayor, M.; Pepe, F.; Segransan, D.; Lister, T.A.; Smalley, B.; Maxted, P.F.L.; Hellier, C.; Anderson, D.R.; Bentley, S.; Pollacco, D.; West, R.G.; Haswell, C.A.; Skillen, I.

    2010-01-01

    We report on the discovery of a new extremely short period transiting extrasolar planet, WASP-19b. The planet has mass M{sub pl} = 1.15 +- 0.08 M{sub J} , radius R{sub pl} = 1.31 +- 0.06 R{sub J} , and orbital period P = 0.7888399 +- 0.0000008 days. Through spectroscopic analysis, we determine the host star to be a slightly super-solar metallicity ([M/H] = 0.1 +- 0.1 dex) G-dwarf with T{sub eff} = 5500 +- 100 K. In addition, we detect periodic, sinusoidal flux variations in the light curve which are used to derive a rotation period for the star of P{sub rot} = 10.5 +- 0.2 days. The relatively short stellar rotation period suggests that either WASP-19 is somewhat young (approx 600 Myr old) or tidal interactions between the two bodies have caused the planet to spiral inward over its lifetime resulting in the spin-up of the star. Due to the detection of the rotation period, this system has the potential to place strong constraints on the stellar tidal quality factor, Q'{sub s}, if a more precise age is determined.

  14. Delving into X-ray obscuration of type 2 AGN, near and far

    SciTech Connect (OSTI)

    LaMassa, Stephanie M.; Meg Urry, C.; Yaqoob, Tahir; Ptak, Andrew F.; Gandhi, Poshak

    2014-05-20

    Using self-consistent, physically motivated models, we investigate the X-ray obscuration in 19 Type 2 [O III] 5007 selected active galactic nuclei (AGNs), 9 of which are local Seyfert 2 galaxies and 10 of which are Type 2 quasar candidates. We derive reliable line-of-sight and global column densities for these objects, which is the first time this has been reported for an AGN sample; four AGNs have significantly different global and line-of-sight column densities. Five sources are heavily obscured to Compton-thick. We comment on interesting sources revealed by our spectral modeling, including a candidate 'naked' Sy2. After correcting for absorption, we find that the ratio of the rest-frame, 2-10 keV luminosity (L{sub 2-10} {sub keV,} {sub in}) to L{sub [O} {sub III]} is 1.54 0.49 dex which is essentially identical to the mean Type 1 AGN value. The Fe K? luminosity is significantly correlated with L{sub [O} {sub III]} but with substantial scatter. Finally, we do not find a trend between L {sub 2-10keV,} {sub in} and global or line-of-sight column density, between column density and redshift, between column density and scattering fraction, or between scattering fraction and redshift.

  15. KINEMATICS AND CHEMISTRY OF HALO SUBSTRUCTURES: THE VICINITY OF THE VIRGO OVERDENSITY

    SciTech Connect (OSTI)

    Casey, Andrew R.; Keller, Stefan C.; Da Costa, Gary

    2012-04-15

    We present observations obtained with the Anglo-Australian Telescope's 2dF wide field spectrograph AAOmega of K-type stars located within a region of the sky which contains the Virgo Overdensity and the leading arm of the Sagittarius Stream. On the basis of the resulting velocity histogram, we isolate halo substructures in these overlapping regions including Sagittarius and previously discovered Virgo groups. Through comparisons with N-body models of the Galaxy-Sagittarius interaction, we find a tri-axial dark matter halo is favored and we exclude a prolate shape. This result is contradictory with other observations along the Sagittarius leading arm, which typically favor prolate models. We have also uncovered K-giant members of Sagittarius that are notably more metal-poor (([Fe/H]) = -1.7 {+-} 0.3 dex) than previous studies. This suggests a significantly wider metallicity distribution exists in the Sagittarius Stream than formerly considered. We also present data on five carbon stars which were discovered in our sample.

  16. TRACING THE ORIGIN OF THE AQUARIUS STREAM. I

    SciTech Connect (OSTI)

    Wylie-de Boer, Elizabeth; Freeman, Kenneth; Keller, Stefan; Williams, Mary; Steinmetz, Matthias; Munari, Ulisse E-mail: kcf@mso.anu.edu.au

    2012-08-10

    We present an abundance analysis of six member stars of the recently discovered Aquarius stream, in an attempt to ascertain whether this halo stream is real and, if so, to understand its origin. The mean metallicities of the six stars have a dispersion of only 0.10 dex, indicating that they are part of a chemically coherent structure. We then investigate whether the stream represents the debris of a disrupted dwarf galaxy or a disrupted globular cluster. The [Ni/Fe]-[Na/Fe] plane provides a good diagnostic: globular cluster stars and dwarf spheroidal galaxy stars are well separated in this plane, and the Aquarius stream stars lie unambiguously in the globular cluster region. The Aquarius stream stars also lie on the distinct [Na/Fe]-[O/Fe] and [Mg/Fe]-[Al/Fe] relations delineated by Galactic globular cluster stars. Spectroscopic parameters for the six Aquarius stars show that they are tightly confined to a 12 Gyr, [Fe/H] =-1.0, {alpha}-enhanced isochrone, consistent with their identification as globular cluster debris. We present evidence that the Aquarius stream may continue through the disk and out into the northern halo. Our results indicate a globular cluster origin for the Aquarius stream and demonstrate the potential for chemical tagging to identify the origins of Galactic substructures.

  17. HUBBLE SPACE TELESCOPE EMISSION-LINE GALAXIES AT z ∼ 2: THE MYSTERY OF NEON

    SciTech Connect (OSTI)

    Zeimann, Gregory R.; Ciardullo, Robin; Gebhardt, Henry; Gronwall, Caryl; Hagen, Alex; Trump, Jonathan R.; Bridge, Joanna S.; Luo, Bin; Schneider, Donald P.

    2015-01-01

    We use near-infrared grism spectroscopy from the Hubble Space Telescope to examine the strength of [Ne III] λ3869 relative to Hβ, [O II] λ3727, and [O III] λ5007 in 236 low-mass (7.5 ≲ log (M {sub *}/M {sub ☉}) ≲ 10.5) star-forming galaxies in the redshift range 1.90 < z < 2.35. By stacking the data by stellar mass, we show that the [Ne III]/[O II] ratios of the z ∼ 2 universe are marginally higher than those seen in a comparable set of local Sloan Digital Sky Survey galaxies, and that [Ne III]/[O III] is enhanced by ∼0.2 dex. We consider the possible explanations for this ∼4σ result, including higher oxygen depletion out of the gas phase, denser H II regions, higher production of {sup 22}Ne via Wolf-Rayet stars, and the existence of a larger population of X-ray obscured active galactic nuclei at z ∼ 2 compared to z ∼ 0. None of these simple scenarios, alone, are favored to explain the observed line ratios. We conclude by suggesting several avenues of future observations to further explore the mystery of enhanced [Ne III] emission.

  18. A NEW COSMOLOGICAL DISTANCE MEASURE USING ACTIVE GALACTIC NUCLEUS X-RAY VARIABILITY

    SciTech Connect (OSTI)

    Franca, Fabio La; Bianchi, Stefano; Branchini, Enzo; Matt, Giorgio [Dipartimento di Matematica e Fisica, Universit Roma Tre, Via della Vasca Navale 84, I-00146, Roma (Italy); Ponti, Gabriele, E-mail: lafranca@fis.uniroma3.it [Max-Planck-Institut fr Extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching bei Mnchen (Germany)

    2014-05-20

    We report the discovery of a luminosity distance estimator using active galactic nuclei (AGNs). We combine the correlation between the X-ray variability amplitude and the black hole (BH) mass with the single-epoch spectra BH mass estimates which depend on the AGN luminosity and the line width emitted by the broad-line region. We demonstrate that significant correlations do exist that allow one to predict the AGN (optical or X-ray) luminosity as a function of the AGN X-ray variability and either the H? or the Pa? line widths. In the best case, when the Pa? is used, the relationship has an intrinsic dispersion of ?0.6dex. Although intrinsically more disperse than supernovae Ia, this relation constitutes an alternative distance indicator potentially able to probe, in an independent way, the expansion history of the universe. With respect to this, we show that the new mission concept Athena should be able to measure the X-ray variability of hundreds of AGNs and then constrain the distance modulus with uncertainties of 0.1mag up to z ? 0.6. We also discuss how our estimator has the prospect of becoming a cosmological probe even more sensitive than the current supernovae Ia samples by using a new dedicated wide-field X-ray telescope able to measure the variability of thousands of AGNs.

  19. Operators Manual and Technical Reference for the Z-Beamlet Phase Modulation Failsafe System: Version 1.

    SciTech Connect (OSTI)

    Armstrong, Darrell J.

    2014-09-01

    The need for pulse energies exceeding 4 kJ and pulse lengths [?] 2 ns in Sandia's Z-Beamlet laser (ZBL) requires that the single-frequency spectrum of its fiber-laser master oscillator be converted to a phase modulated spectrum with a modulation in dex [?] 5. Because accidental injection of single-frequency light into ZBL could result i n damage to optical materials from transverse stimulated Brillouin scattering, the presence of phase modulated (PM) light must be monitored by a reliable failsafe system that can stop a las er shot within of a few 10's of ns following a failure of the PM system. This requirement is met by combining optical heterodyne detection with high-speed electronics to indicate the pres ence or absence of phase modulated light. The transition time for the failsafe signal resultin g from a sudden failure using this technique is approximately 35 ns. This is sufficiently short to safely stop a single-frequency laser pulse from leaving ZBL's regenerative amplifier with a n approximately 35 ns margin of safety. This manual and technical reference contains detai led instructions for daily use of the PM failsafe system and provides enough additional informat ion for its maintenance and repair.

  20. Normal and outlying populations of the Milky Way stellar halo at [Fe/H] <2

    SciTech Connect (OSTI)

    Cohen, Judith G.; Christlieb, Norbert; Thompson, Ian; McWilliam, Andrew; Shectman, Stephen; Reimers, Dieter; Wisotzki, Lutz; Kirby, Evan E-mail: N.Christlieb@lsw.uni-heidelberg.de E-mail: shec@obs.carnegiescience.edu E-mail: dreimers@hs.uni-hamburg.de E-mail: ekirby@uci.edu

    2013-11-20

    From detailed abundance analysis of >100 Hamburg/ESO candidate extremely metal-poor (EMP) stars we find 45 with [Fe/H] < 3.0 dex. We identify a heretofore unidentified group: Ca-deficient stars with sub-solar [Ca/Fe] ratios and the lowest neutron-capture abundances; the Ca-deficient group comprises ?10% of the sample, excluding Carbon stars. Our radial velocity distribution shows that the carbon-enhanced stars with no s-process enhancements, CEMP-no, and which do not show C{sub 2} bands are not preferentially binary systems. Ignoring Carbon stars, approximately 15% of our sample are strong (?5?) outliers in one or more elements between Mg and Ni; this rises to ?19% if very strong (?10?) outliers for Sr and Ba are included. Examples include: HE03050554 with the lowest [Ba/H] known; HE10121540 and HE23230256, two (non-velocity variable) C-rich stars with very strong [Mg,Al/Fe] enhancements; and HE12261149, an extremely r-process rich star.

  1. LITHIUM ABUNDANCES OF EXTREMELY METAL-POOR TURNOFF STARS

    SciTech Connect (OSTI)

    Aoki, Wako; Inoue, Susumu; Barklem, Paul S.; Beers, Timothy C.; Christlieb, Norbert; Perez, Ana E. GarcIa; Norris, John E.; Carollo, Daniela E-mail: Paul.Barklem@physics.uu.se E-mail: N.Christlieb@lsw.uni-heidelberg.de E-mail: jen@mso.anu.edu.au E-mail: inoue@tap.scphys.kyoto-u.ac.jp

    2009-06-20

    We have determined Li abundances for eleven metal-poor turnoff stars, among which eight have [Fe/H] <-3, based on LTE analyses of high-resolution spectra obtained with the High Dispersion Spectrograph on the Subaru Telescope. The Li abundances for four of these eight stars are determined for the first time by this study. Effective temperatures are determined by a profile analysis of H{alpha} and H{beta}. While seven stars have Li abundances as high as the Spite Plateau value, the remaining four objects with [Fe/H] <-3 have A(Li) =log (Li/H)+ 12 {approx}< 2.0, confirming the existence of extremely metal-poor (EMP) turnoff stars having low Li abundances, as reported by previous work. The average of the Li abundances for stars with [Fe/H]<-3 is lower by 0.2 dex than that of the stars with higher metallicity. No clear constraint on the metallicity dependence or scatter of the Li abundances is derived from our measurements for the stars with [Fe/H]<-3. Correlations of the Li abundance with effective temperatures, with abundances of Na, Mg, and Sr, and with the kinematical properties are investigated, but no clear correlation is seen in the EMP star sample.

  2. CALIBRATING C-IV-BASED BLACK HOLE MASS ESTIMATORS

    SciTech Connect (OSTI)

    Park, Daeseong; Woo, Jong-Hak; Shin, Jaejin [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Denney, Kelly D., E-mail: pds2001@astro.snu.ac.kr, E-mail: woo@astro.snu.ac.kr, E-mail: jjshin@astro.snu.ac.kr, E-mail: kelly@dark-cosmology.dk [Dark Cosmology Centre, Niels Bohr Institute, Juliane Maries Vej 30, DK-2100 Copenhagen O (Denmark)

    2013-06-20

    We present the single-epoch black hole mass estimators based on the C IV {lambda}1549 broad emission line, using the updated sample of the reverberation-mapped active galactic nuclei and high-quality UV spectra. By performing multi-component spectral fitting analysis, we measure the C IV line widths (FWHM{sub C{sub IV}} and line dispersion, {sigma}{sub C{sub IV}}) and the continuum luminosity at 1350 A (L{sub 1350}) to calibrate the C-IV-based mass estimators. By comparing with the H{beta} reverberation-based masses, we provide new mass estimators with the best-fit relationships, i.e., M{sub BH}{proportional_to}L{sub 1350}{sup 0.50{+-}0.07}{sigma}{sub C{sub IV}{sup 2}} and M{sub BH}{proportional_to}L{sub 1350}{sup 0.52{+-}0.09} FWHM{sub C{sub IV}{sup 0.56{+-}0.48}}. The new C-IV-based mass estimators show significant mass-dependent systematic difference compared to the estimators commonly used in the literature. Using the published Sloan Digital Sky Survey QSO catalog, we show that the black hole mass of high-redshift QSOs decreases on average by {approx}0.25 dex if our recipe is adopted.

  3. THE COS/UVES ABSORPTION SURVEY OF THE MAGELLANIC STREAM. II. EVIDENCE FOR A COMPLEX ENRICHMENT HISTORY OF THE STREAM FROM THE FAIRALL 9 SIGHTLINE

    SciTech Connect (OSTI)

    Richter, Philipp; Fechner, Cora [Institut fuer Physik und Astronomie, Universitaet Potsdam, Haus 28, Karl-Liebknecht-Str. 24/25, D-14476 Golm (Potsdam) (Germany); Fox, Andrew J. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Wakker, Bart P. [Department of Astronomy, University of Wisconsin-Madison, 475 North Charter Street, Madison, WI 53706 (United States); Lehner, Nicolas; Howk, J. Christopher [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Bland-Hawthorn, Joss [Institute of Astronomy, School of Physics, University of Sydney, NSW 2006 (Australia); Ben Bekhti, Nadya [Argelander-Institut fuer Astronomie, Universitaet Bonn, Auf dem Huegel 71, D-53121 Bonn (Germany)

    2013-08-01

    We present a multi-wavelength study of the Magellanic Stream (MS), a massive gaseous structure in the Local Group that is believed to represent material stripped from the Magellanic Clouds. We use ultraviolet, optical and radio data obtained with HST/COS, VLT/UVES, FUSE, GASS, and ATCA to study metal abundances and physical conditions in the Stream toward the quasar Fairall 9. Line absorption in the MS from a large number of metal ions and from molecular hydrogen is detected in up to seven absorption components, indicating the presence of multi-phase gas. From the analysis of unsaturated S II absorption, in combination with a detailed photoionization model, we obtain a surprisingly high {alpha} abundance in the Stream toward Fairall 9 of [S/H] = -0.30 {+-} 0.04 (0.50 solar). This value is five times higher than what is found along other MS sightlines based on similar COS/UVES data sets. In contrast, the measured nitrogen abundance is found to be substantially lower ([N/H] = -1.15 {+-} 0.06), implying a very low [N/{alpha}] ratio of -0.85 dex. The substantial differences in the chemical composition of MS toward Fairall 9 compared to other sightlines point toward a complex enrichment history of the Stream. We favor a scenario, in which the gas toward Fairall 9 was locally enriched with {alpha} elements by massive stars and then was separated from the Magellanic Clouds before the delayed nitrogen enrichment from intermediate-mass stars could set in. Our results support (but do not require) the idea that there is a metal-enriched filament in the Stream toward Fairall 9 that originates in the LMC.

  4. ALPHA ENHANCEMENT AND THE METALLICITY DISTRIBUTION FUNCTION OF PLAUT'S WINDOW

    SciTech Connect (OSTI)

    Johnson, Christian I.; Michael Rich, R.; Fulbright, Jon P.; Valenti, Elena; McWilliam, Andrew E-mail: rmr@astro.ucla.edu E-mail: evalenti@eso.org

    2011-05-10

    We present Fe, Si, and Ca abundances for 61 giants in Plaut's window (l = -1{sup 0}, b = -8.{sup 0}5) and Fe abundances for an additional 31 giants in a second, nearby field (l = 0{sup 0}, b = -8{sup 0}) derived from high-resolution (R {approx} 25,000) spectra obtained with the Blanco 4 m telescope and Hydra multifiber spectrograph. The median metallicity of red giant branch (RGB) stars in the Plaut's field is {approx}0.4 dex lower than those in Baade's window, and confirms the presence of an iron abundance gradient along the bulge minor axis. The full metallicity range of our (biased) RGB sample spans -1.5 < [Fe/H] < +0.3, which is similar to that found in other bulge fields. We also derive a photometric metallicity distribution function for RGB stars in the (l = -1{sup 0}, b = -8{sup 0}.5) field and find very good agreement with the spectroscopic metallicity distribution. The radial velocity (RV) and dispersion data for the bulge RGB stars are in agreement with previous results of the Bulge Radial Velocity Assay survey, and we find evidence for a decreasing velocity dispersion with increasing [Fe/H]. The [{alpha}/Fe] enhancement in Plaut field stars is nearly identical to that observed in Baade's window, and suggests that an [{alpha}/Fe] gradient does not exist between b = -4{sup 0} and -8{sup 0}. Additionally, a subset of our sample (23 stars) appears to be foreground red clump stars that are very metal rich, exhibit small metallicity and RV dispersions, and are enhanced in {alpha} elements. While these stars likely belong to the Galactic inner disk population, they exhibit [{alpha}/Fe] ratios that are enhanced above the thin and thick disk.

  5. Decoding the message from meteoritic stardust silicon carbide grains

    SciTech Connect (OSTI)

    Lewis, Karen M.; Lugaro, Maria; Gibson, Brad K.; Pilkington, Kate

    2014-05-02

    SiC mainstream grains are presolar grains believed to form in the envelopes of carbon rich asymptotic giant branch (AGB) stars with masses between 1.5 and 3 solar masses. These grains represent a conundrum as the {sup 29}Si and {sup 30}Si abundances indicate that they formed in stars of super-solar metallicity, before the solar system formed. To shed light on this problem, we use silicon isotopic abundances to derive an age-metallicity relation for the stars believed to have produced the SiC mainstream grains. For 2732 mainstream SiC grains listed in the Presolar Grain Database, we use the {sup 29}Si abundances with the latest galactic chemical evolution (GCE) models to derive [Fe/H], and {sup 30}Si abundances along with the models of Zinner et al. (2006) to determine an approximate birth age for the parent AGB star. Comparing our age-metallicity relation with observational relationships derived for nearby stars, we find that the spread of [Fe/H] is in agreement, but the mean [Fe/H] in our relation is higher by 0.2 dex. We propose that this difference is because stars with higher [Fe/H] produce more dust and thus are over-represented in our age metallicity diagram, a finding consistent with previous published works. This result offers a solution for the long-standing problem of silicon in Stardust SiC grains, confirms the necessity of coupling chemistry and dynamics in simulations of the chemical evolution of our Galaxy, and constrains the modelling of dust condensation in stellar winds as a function of the metallicity.

  6. The FMOS-COSMOS survey of star-forming galaxies at z ∼ 1.6. II. The mass-metallicity relation and the dependence on star formation rate and dust extinction

    SciTech Connect (OSTI)

    Zahid, H. J.; Sanders, D. B.; Chu, J.; Hasinger, G.; Kashino, D.; Silverman, J. D.; Kewley, L. J.; Daddi, E.; Renzini, A.; Rodighiero, G.; Nagao, T.; Arimoto, N.; Kartaltepe, J.; Lilly, S. J.; Carollo, C. M.; Maier, C.; Geller, M. J.; Capak, P.; Ilbert, O.; Kajisawa, M.; Collaboration: COSMOS Team; and others

    2014-09-01

    We investigate the relationships between stellar mass, gas-phase oxygen abundance (metallicity), star formation rate (SFR), and dust content of star-forming galaxies at z ∼ 1.6 using Subaru/FMOS spectroscopy in the COSMOS field. The mass-metallicity (MZ) relation at z ∼ 1.6 is steeper than the relation observed in the local universe. The steeper MZ relation at z ∼ 1.6 is mainly due to evolution in the stellar mass where the MZ relation begins to turnover and flatten. This turnover mass is 1.2 dex larger at z ∼ 1.6. The most massive galaxies at z ∼ 1.6 (∼10{sup 11} M {sub ☉}) are enriched to the level observed in massive galaxies in the local universe. The MZ relation we measure at z ∼ 1.6 supports the suggestion of an empirical upper metallicity limit that does not significantly evolve with redshift. We find an anti-correlation between metallicity and SFR for galaxies at a fixed stellar mass at z ∼ 1.6, which is similar to trends observed in the local universe. We do not find a relation between stellar mass, metallicity, and SFR that is independent of redshift; rather, our data suggest that there is redshift evolution in this relation. We examine the relation between stellar mass, metallicity, and dust extinction, and find that at a fixed stellar mass, dustier galaxies tend to be more metal rich. From examination of the stellar masses, metallicities, SFRs, and dust extinctions, we conclude that stellar mass is most closely related to dust extinction.

  7. RECONCILING THE OBSERVED STAR-FORMING SEQUENCE WITH THE OBSERVED STELLAR MASS FUNCTION

    SciTech Connect (OSTI)

    Leja, Joel; Van Dokkum, Pieter G.; Franx, Marijn; Whitaker, Katherine E.

    2015-01-10

    We examine the connection between the observed star-forming sequence (SFR ? M {sup ?}) and the observed evolution of the stellar mass function in the range 0.2 < z < 2.5. We find that the star-forming sequence cannot have a slope ? ? 0.9 at all masses and redshifts because this would result in a much higher number density at 10 < log (M/M {sub ?}) < 11 by z = 1 than is observed. We show that a transition in the slope of the star-forming sequence, such that ? = 1 at log (M/M {sub ?}) < 10.5 and ? = 0.7-0.13z (Whitaker et al.) at log (M/M {sub ?}) > 10.5, greatly improves agreement with the evolution of the stellar mass function. We then derive a star-forming sequence that reproduces the evolution of the mass function by design. This star-forming sequence is also well described by a broken power law, with a shallow slope at high masses and a steep slope at low masses. At z = 2, it is offset by ?0.3 dex from the observed star-forming sequence, consistent with the mild disagreement between the cosmic star formation rate (SFR) and recent observations of the growth of the stellar mass density. It is unclear whether this problem stems from errors in stellar mass estimates, errors in SFRs, or other effects. We show that a mass-dependent slope is also seen in other self-consistent models of galaxy evolution, including semianalytical, hydrodynamical, and abundance-matching models. As part of the analysis, we demonstrate that neither mergers nor hidden low-mass quiescent galaxies are likely to reconcile the evolution of the mass function and the star-forming sequence. These results are supported by observations from Whitaker et al.

  8. Generation and characterization of gsuα:EGFP transgenic zebrafish for evaluating endocrine-disrupting effects

    SciTech Connect (OSTI)

    Cheng, Xiaoxia; Chen, Xiaowen; Jin, Xia; He, Jiangyan; Yin, Zhan

    2014-07-01

    The glycoprotein subunit α (gsuα) gene encodes the shared α subunit of the three pituitary heterodimeric glycoprotein hormones: follicle-stimulating hormone β (Fshβ), luteinizing hormone β (Lhβ) and thyroid stimulating hormone β (Tshβ). In our current study, we identified and characterized the promoter region of zebrafish gsuα and generated a stable gsuα:EGFP transgenic line, which recapitulated the endogenous gsuα expression in the early developing pituitary gland. A relatively conserved regulatory element set is presented in the promoter regions of zebrafish and three other known mammalian gsuα promoters. Our results also demonstrated that the expression patterns of the gsuα:EGFP transgene were all identical to those expression patterns of the endogenous gsuα expression in the pituitary tissue when our transgenic fish were treated with various endocrine chemicals, including forskolin (FSK), SP600125, trichostatin A (TSA), KClO{sub 4}, dexamethasone (Dex), β-estradiol and progesterone. Thus, this gsuα:EGFP transgenic fish reporter line provides another valuable tool for investigating the lineage development of gsuα-expressing gonadotrophins and the coordinated regulation of various glycoprotein hormone subunit genes. These reporter fish can serve as a novel platform to perform screenings of endocrine-disrupting chemicals (EDCs) in vivo as well. - Highlights: • Identification of the promoter of zebrafish glycoprotein subunit α (gsuα) gene • Generation of stable transmission gsuα:EGFP transgenic zebrafish reporter • Demonstration of the recapitulation of the gsuα:EGFP and endogenous gsuα expression • Suggestion of the gsuα:EGFP transgenic zebrafish as a novel platform for EDC study.

  9. The mass spectrum of the first stars

    SciTech Connect (OSTI)

    Susa, Hajime; Tominaga, Nozomu; Hasegawa, Kenji

    2014-09-01

    We perform cosmological hydrodynamics simulations with non-equilibrium primordial chemistry to obtain 59 minihalos that host first stars. The obtained minihalos are used as the initial conditions of local three-dimensional radiation hydrodynamics simulations to investigate the formation of the first stars. We find that two-thirds of the minihalos host multiple stars, while the other third has single stars. The mass of the stars found in our simulations are in the range of 1 M {sub ☉} ≲ M ≲ 300 M {sub ☉}, peaking at several× 10 M {sub ☉}. Most of the very massive stars of ≳ 140 M {sub ☉} are born as single stars, although not all of the single stars are very massive. We also find a few stars of ≲ 1 M {sub ☉} that are kicked by the gravitational three body interactions to the position distant from the center of mass. The frequency that a star forming minihalo contains a binary system is ∼50%. We also investigate the abundance pattern of the stellar remnants by summing up the contributions from the first stars in the simulations. Consequently, the pattern is compatible with that of the low metallicity damped Lyα systems or the extremely metal-poor (EMP) stars, if the mass spectrum obtained in our experiment is shifted to the low mass side by 0.2 dex. If we consider the case that an EMP star is born in the remnant of the individual minihalo without mixing with others, the chemical signature of the pair instability supernova is more prominent, because most of them are born as single stars.

  10. Comparing the host galaxies of type Ia, type II, and type Ibc supernovae

    SciTech Connect (OSTI)

    Shao, X.; Liang, Y. C.; Chen, X. Y.; Zhong, G. H.; Deng, L. C.; Zhang, B.; Shi, W. B.; Zhou, L.; Dennefeld, M.; Hammer, F.; Flores, H. E-mail: ycliang@bao.ac.cn

    2014-08-10

    We compare the host galaxies of 902 supernovae (SNe), including SNe Ia, SNe II, and SNe Ibc, which are selected by cross-matching the Asiago Supernova Catalog with the Sloan Digital Sky Survey (SDSS) Data Release 7. We selected an additional 213 galaxies by requiring the light fraction of spectral observations to be >15%, which could represent well the global properties of the galaxies. Among these 213 galaxies, 135 appear on the Baldwin-Phillips-Terlevich diagram, which allows us to compare the hosts in terms of whether they are star-forming (SF) galaxies, active galactic nuclei (AGNs; including composites, LINERs, and Seyfert 2s) or absorption-line galaxies (Absorps; i.e., their related emission lines are weak or non-existent). The diagrams related to the parameters D{sub n}(4000), H?{sub A}, stellar masses, star formation rates (SFRs), and specific SFRs for the SNe hosts show that almost all SNe II and most of the SNe Ibc occur in SF galaxies, which have a wide range of stellar masses and low D{sub n}(4000). The SNe Ia hosts as SF galaxies following similar trends. A significant fraction of SNe Ia occurs in AGNs and absorption-line galaxies, which are massive and have high D{sub n}(4000). The stellar population analysis from spectral synthesis fitting shows that the hosts of SNe II have a younger stellar population than hosts of SNe Ia. These results are compared with those of the 689 comparison galaxies where the SDSS fiber captures less than 15% of the total light. These comparison galaxies appear biased toward higher 12+log(O/H) (?0.1 dex) at a given stellar mass. Therefore, we believe the aperture effect should be kept in mind when the properties of the hosts for different types of SNe are discussed.

  11. IZI: INFERRING THE GAS PHASE METALLICITY (Z) AND IONIZATION PARAMETER (q) OF IONIZED NEBULAE USING BAYESIAN STATISTICS

    SciTech Connect (OSTI)

    Blanc, Guillermo A.; Kewley, Lisa; Vogt, Frédéric P. A.; Dopita, Michael A.

    2015-01-10

    We present a new method for inferring the metallicity (Z) and ionization parameter (q) of H II regions and star-forming galaxies using strong nebular emission lines (SELs). We use Bayesian inference to derive the joint and marginalized posterior probability density functions for Z and q given a set of observed line fluxes and an input photoionization model. Our approach allows the use of arbitrary sets of SELs and the inclusion of flux upper limits. The method provides a self-consistent way of determining the physical conditions of ionized nebulae that is not tied to the arbitrary choice of a particular SEL diagnostic and uses all the available information. Unlike theoretically calibrated SEL diagnostics, the method is flexible and not tied to a particular photoionization model. We describe our algorithm, validate it against other methods, and present a tool that implements it called IZI. Using a sample of nearby extragalactic H II regions, we assess the performance of commonly used SEL abundance diagnostics. We also use a sample of 22 local H II regions having both direct and recombination line (RL) oxygen abundance measurements in the literature to study discrepancies in the abundance scale between different methods. We find that oxygen abundances derived through Bayesian inference using currently available photoionization models in the literature can be in good (∼30%) agreement with RL abundances, although some models perform significantly better than others. We also confirm that abundances measured using the direct method are typically ∼0.2 dex lower than both RL and photoionization-model-based abundances.

  12. Gemini long-slit observations of luminous obscured quasars: Further evidence for an upper limit on the size of the narrow-line region

    SciTech Connect (OSTI)

    Hainline, Kevin N.; Hickox, Ryan C.; Greene, Jenny E.; Myers, Adam D.; Zakamska, Nadia L.; Liu, Guilin; Liu, Xin

    2014-05-20

    We examine the spatial extent of the narrow-line regions (NLRs) of a sample of 30 luminous obscured quasars at 0.4 < z < 0.7 observed with spatially resolved Gemini-N GMOS long-slit spectroscopy. Using the [O III] ?5007 emission feature, we estimate the size of the NLR using a cosmology-independent measurement: the radius where the surface brightness falls to 10{sup 15} erg s{sup 1} cm{sup 2} arcsec{sup 2}. We then explore the effects of atmospheric seeing on NLR size measurements and conclude that direct measurements of the NLR size from observed profiles are too large by 0.1-0.2 dex on average, as compared to measurements made to best-fit Srsic or Voigt profiles convolved with the seeing. These data, which span a full order of magnitude in IR luminosity (log (L {sub 8} {sub ?m}/erg s{sup 1}) = 44.4-45.4), also provide strong evidence that there is a flattening of the relationship between NLR size and active galactic nucleus luminosity at a seeing-corrected size of ?7 kpc. The objects in this sample have high luminosities which place them in a previously under-explored portion of the size-luminosity relationship. These results support the existence of a maximal size of the NLR around luminous quasars; beyond this size, there is either not enough gas or the gas is over-ionized and does not produce enough [O III] ?5007 emission.

  13. METALLICITY GRADIENT OF A LENSED FACE-ON SPIRAL GALAXY AT REDSHIFT 1.49

    SciTech Connect (OSTI)

    Yuan, T.-T.; Kewley, L. J.; Swinbank, A. M.; Richard, J.; Livermore, R. C.

    2011-05-01

    We present the first metallicity gradient measurement for a grand-design face-on spiral galaxy at z {approx} 1.5. This galaxy has been magnified by a factor of 22x by a massive, X-ray luminous galaxy cluster MACS J1149.5+2223 at z = 0.544. Using the Laser Guide Star Adaptive Optics aided integral field spectrograph OSIRIS on KECK II, we target the H{alpha} emission and achieve a spatial resolution of 0.''1, corresponding to a source-plane resolution of 170 pc. The galaxy has well-developed spiral arms and the nebular emission line dynamics clearly indicate a rotationally supported disk with V{sub rot}/{sigma} {approx} 4. The best-fit disk velocity field model yields a maximum rotation of V{sub rot}sin i = 150 {+-} 15 km s{sup -1}, and a dynamical mass of M{sub dyn} = (1.3 {+-} 0.2) x 10{sup 10} cosec{sup 2}(i) M{sub sun} (within 2.5 kpc), where the inclination angle i = 45{sup 0} {+-} 10{sup 0}. Based on the [N II] and H{alpha} ratios, we measured the radial chemical abundance gradient from the inner hundreds of parsecs out to {approx}5 kpc. The slope of the gradient is -0.16 {+-} 0.02 dex kpc{sup -1}, significantly steeper than the gradient of late-type or early-type galaxies in the local universe. If representative of disk galaxies at z {approx} 1.5, our results support an 'inside-out' disk formation scenario in which early infall/collapse in the galaxy center builds a chemically enriched nucleus, followed by slow enrichment of the disk over the next 9 Gyr.

  14. DIAGNOSING THE TIME DEPENDENCE OF ACTIVE REGION CORE HEATING FROM THE EMISSION MEASURE. II. NANOFLARE TRAINS

    SciTech Connect (OSTI)

    Reep, J. W.; Bradshaw, S. J.; Klimchuk, J. A. E-mail: stephen.bradshaw@rice.edu

    2013-02-20

    The time dependence of heating in solar active regions can be studied by analyzing the slope of the emission measure distribution coolward of the peak. In a previous study we showed that low-frequency heating can account for 0% to 77% of active region core emission measures. We now turn our attention to heating by a finite succession of impulsive events for which the timescale between events on a single magnetic strand is shorter than the cooling timescale. We refer to this scenario as a 'nanoflare train' and explore a parameter space of heating and coronal loop properties with a hydrodynamic model. Our conclusions are (1) nanoflare trains are consistent with 86% to 100% of observed active region cores when uncertainties in the atomic data are properly accounted for; (2) steeper slopes are found for larger values of the ratio of the train duration {Delta} {sub H} to the post-train cooling and draining timescale {Delta} {sub C}, where {Delta} {sub H} depends on the number of heating events, the event duration and the time interval between successive events ({tau} {sub C}); (3) {tau} {sub C} may be diagnosed from the width of the hot component of the emission measure provided that the temperature bins are much smaller than 0.1 dex; (4) the slope of the emission measure alone is not sufficient to provide information about any timescale associated with heating-the length and density of the heated structure must be measured for {Delta} {sub H} to be uniquely extracted from the ratio {Delta} {sub H}/{Delta} {sub C}.

  15. THE COMPLEX PHYSICS OF DUSTY STAR-FORMING GALAXIES AT HIGH REDSHIFTS AS REVEALED BY HERSCHEL AND SPITZER

    SciTech Connect (OSTI)

    Lo Faro, B.; Franceschini, A.; Vaccari, M.; Rodighiero, G.; Feltre, A.; Marchetti, L.; Silva, L.; Berta, S.; Lutz, D.; Magnelli, B.; Bock, J.; Burgarella, D.; Buat, V.; Cava, A.; Clements, D. L.; Cooray, A.; Farrah, D.; Hurley, P.; Solares, E. A. Gonzalez; Magdis, G.; and others

    2013-01-10

    We combine far-infrared photometry from Herschel (PEP/HerMES) with deep mid-infrared spectroscopy from Spitzer to investigate the nature and the mass assembly history of a sample of 31 luminous and ultraluminous infrared galaxies ((U)LIRGs) at z {approx} 1 and 2 selected in GOODS-S with 24 {mu}m fluxes between 0.2 and 0.5 mJy. We model the data with a self-consistent physical model (GRASIL) which includes a state-of-the-art treatment of dust extinction and reprocessing. We find that all of our galaxies appear to require massive populations of old (>1 Gyr) stars and, at the same time, to host a moderate ongoing activity of star formation (SFR {<=} 100 M {sub Sun} yr{sup -1}). The bulk of the stars appear to have been formed a few Gyr before the observation in essentially all cases. Only five galaxies of the sample require a recent starburst superimposed on a quiescent star formation history. We also find discrepancies between our results and those based on optical-only spectral energy distribution (SED) fitting for the same objects; by fitting their observed SEDs with our physical model we find higher extinctions (by {Delta}A {sub V} {approx} 0.81 and 1.14) and higher stellar masses (by {Delta}log(M {sub *}) {approx} 0.16 and 0.36 dex) for z {approx} 1 and z {approx} 2 (U)LIRGs, respectively. The stellar mass difference is larger for the most dust-obscured objects. We also find lower SFRs than those computed from L {sub IR} using the Kennicutt relation due to the significant contribution to the dust heating by intermediate-age stellar populations through 'cirrus' emission ({approx}73% and {approx}66% of the total L {sub IR} for z {approx} 1 and z {approx} 2 (U)LIRGs, respectively).

  16. Possible evidence for metal accretion onto the surfaces of metal-poor main-sequence stars

    SciTech Connect (OSTI)

    Hattori, Kohei; Yoshii, Yuzuru; Beers, Timothy C.; Carollo, Daniela; Lee, Young Sun

    2014-04-01

    The entire evolution of the Milky Way, including its mass-assembly and star-formation history, is imprinted onto the chemo-dynamical distribution function of its member stars, f(x, v, [X/H]), in the multi-dimensional phase space spanned by position, velocity, and elemental abundance ratios. In particular, the chemo-dynamical distribution functions for low-mass stars (e.g., G- or K-type dwarfs) are precious tracers of the earliest stages of the Milky Way's formation, since their main-sequence lifetimes approach or exceed the age of the universe. A basic tenet of essentially all previous analyses is that the stellar metallicity, usually parameterized as [Fe/H], is conserved over time for main-sequence stars (at least those that have not been polluted due to mass transfer from binary companions). If this holds true, any correlations between metallicity and kinematics for long-lived main-sequence stars of different masses, effective temperatures, or spectral types must strictly be the same, since they reflect the same mass-assembly and star-formation histories. By analyzing a sample of nearby metal-poor halo and thick-disk stars on the main sequence, taken from Data Release 8 of the Sloan Digital Sky Survey, we find that the median metallicity of G-type dwarfs is systematically higher (by about 0.2 dex) than that of K-type dwarfs having the same median rotational velocity about the Galactic center. If it can be confirmed, this finding may invalidate the long-accepted assumption that the atmospheric metallicities of long-lived stars are conserved over time.

  17. THE FUTURE OF THE SUN: AN EVOLVED SOLAR TWIN REVEALED BY CoRoT

    SciTech Connect (OSTI)

    Do Nascimento, J.-D. Jr.; Da Costa, J. S.; Castro, M.; Takeda, Y.; Melendez, J.

    2013-07-10

    The question of whether the Sun is peculiar within the class of solar-type stars has been the subject of active investigation over the past three decades. Although several solar twins have been found with stellar parameters similar to those of the Sun (albeit in a range of Li abundances and with somewhat different compositions), their rotation periods are unknown, except for 18 Sco, which is younger than the Sun and with a rotation period shorter than solar. It is difficult to obtain rotation periods for stars of solar age from ground-based observations, as a low-activity level implies a shallow rotational modulation of their light curves. CoRoT has provided space-based long time series from which the rotation periods of solar twins as old as the Sun could be estimated. Based on high-signal-to-noise, high-resolution spectroscopic observations gathered at the Subaru Telescope, we show that the star CoRoT ID 102684698 is a somewhat evolved solar twin with a low Li abundance. Its rotation period is 29 {+-} 5 days, compatible with its age (6.7 Gyr) and low lithium content, A{sub Li} {approx}< 0.85 dex. Interestingly, our CoRoT solar twin seems to have enhanced abundances of the refractory elements with respect to the Sun, a typical characteristic of most nearby twins. With a magnitude V {approx_equal} 14.1, ID 102684698 is the first solar twin revealed by CoRoT, the farthest field solar twin so far known, and the only solar twin older than the Sun for which a rotation period has been determined.

  18. EXPLORING THE DIVERSITY OF GROUPS AT 0.1 < z < 0.8 WITH X-RAY AND OPTICALLY SELECTED SAMPLES

    SciTech Connect (OSTI)

    Connelly, J. L.; Wilman, David J.; Finoguenov, Alexis; Saglia, Roberto; Hou, Annie; Parker, Laura C.; Henderson, Robert D. E.; Mulchaey, John S.; McGee, Sean L.; Balogh, Michael L.; Bower, Richard G.

    2012-09-10

    We present the global group properties of two samples of galaxy groups containing 39 high-quality X-ray-selected systems and 38 optically (spectroscopically) selected systems in coincident spatial regions at 0.12 < z < 0.79. The total mass range of the combined sample is {approx}(10{sup 12}-5) Multiplication-Sign 10{sup 14} M{sub Sun }. Only nine optical systems are associable with X-ray systems. We discuss the confusion inherent in the matching of both galaxies to extended X-ray emission and of X-ray emission to already identified optical systems. Extensive spectroscopy has been obtained and the resultant redshift catalog and group membership are provided here. X-ray, dynamical, and total stellar masses of the groups are also derived and presented. We explore the effects of utilizing different centers and applying three different kinds of radial cut to our systems: a constant cut of 1 Mpc and two r{sub 200} cuts, one based on the velocity dispersion of the system and the other on the X-ray emission. We find that an X-ray-based r{sub 200} results in less scatter in scaling relations and less dynamical complexity as evidenced by results of the Anderson-Darling and Dressler-Schectman tests, indicating that this radius tends to isolate the virialized part of the system. The constant and velocity dispersion based cuts can overestimate membership and can work to inflate velocity dispersion and dynamical and stellar mass. We find L{sub X} -{sigma} and M{sub stellar}-L{sub X} scaling relations for X-ray and optically selected systems are not dissimilar. The mean fraction of mass found in stars, excluding intracluster light, for our systems is {approx}0.014 with a logarithmic standard deviation of 0.398 dex. We also define and investigate a sample of groups which are X-ray underluminous given the total group stellar mass. For these systems the fraction of stellar mass contributed by the most massive galaxy is typically lower than that found for the total population of groups implying that there may be less intragroup medium contributed from the most massive member in these systems. Eighty percent of 15 underluminous groups have less than 40% of their stellar mass in the most massive galaxy which happens in less than 1% of cases with samples matched in stellar mass, taken from the combined group catalog.

  19. The large-scale structure of the halo of the Andromeda galaxy. I. Global stellar density, morphology and metallicity properties

    SciTech Connect (OSTI)

    Ibata, Rodrigo A.; Martin, Nicolas F.; Lewis, Geraint F.; McConnachie, Alan W.; Irwin, Michael J.; Ferguson, Annette M. N.; Bernard, Edouard J.; Peñarrubia, Jorge; Babul, Arif; Navarro, Julio; Chapman, Scott C.; Collins, Michelle; Fardal, Mark; Mackey, A. D.; Rich, R. Michael; Tanvir, Nial; Widrow, Lawrence

    2014-01-10

    We present an analysis of the large-scale structure of the halo of the Andromeda galaxy, based on the Pan-Andromeda Archeological Survey (PAndAS), currently the most complete map of resolved stellar populations in any galactic halo. Despite the presence of copious substructures, the global halo populations follow closely power-law profiles that become steeper with increasing metallicity. We divide the sample into stream-like populations and a smooth halo component (defined as the population that cannot be resolved into spatially distinct substructures with PAndAS). Fitting a three-dimensional halo model reveals that the most metal-poor populations ([Fe/H]<−1.7) are distributed approximately spherically (slightly prolate with ellipticity c/a = 1.09 ± 0.03), with only a relatively small fraction residing in discernible stream-like structures (f {sub stream} = 42%). The sphericity of the ancient smooth component strongly hints that the dark matter halo is also approximately spherical. More metal-rich populations contain higher fractions of stars in streams, with f {sub stream} becoming as high as 86% for [Fe/H]>−0.6. The space density of the smooth metal-poor component has a global power-law slope of γ = –3.08 ± 0.07, and a non-parametric fit shows that the slope remains nearly constant from 30 kpc to ∼300 kpc. The total stellar mass in the halo at distances beyond 2° is ∼1.1 × 10{sup 10} M {sub ☉}, while that of the smooth component is ∼3 × 10{sup 9} M {sub ☉}. Extrapolating into the inner galaxy, the total stellar mass of the smooth halo is plausibly ∼8 × 10{sup 9} M {sub ☉}. We detect a substantial metallicity gradient, which declines from ([Fe/H]) = –0.7 at R = 30 kpc to ([Fe/H]) = –1.5 at R = 150 kpc for the full sample, with the smooth halo being ∼0.2 dex more metal poor than the full sample at each radius. While qualitatively in line with expectations from cosmological simulations, these observations are of great importance as they provide a prototype template that such simulations must now be able to reproduce in quantitative detail.

  20. TU-F-17A-08: The Relative Accuracy of 4D Dose Accumulation for Lung Radiotherapy Using Rigid Dose Projection Versus Dose Recalculation On Every Breathing Phase

    SciTech Connect (OSTI)

    Lamb, J; Lee, C; Tee, S; Lee, P; Iwamoto, K; Low, D; Valdes, G; Robinson, C

    2014-06-15

    Purpose: To investigate the accuracy of 4D dose accumulation using projection of dose calculated on the end-exhalation, mid-ventilation, or average intensity breathing phase CT scan, versus dose accumulation performed using full Monte Carlo dose recalculation on every breathing phase. Methods: Radiotherapy plans were analyzed for 10 patients with stage I-II lung cancer planned using 4D-CT. SBRT plans were optimized using the dose calculated by a commercially-available Monte Carlo algorithm on the end-exhalation 4D-CT phase. 4D dose accumulations using deformable registration were performed with a commercially available tool that projected the planned dose onto every breathing phase without recalculation, as well as with a Monte Carlo recalculation of the dose on all breathing phases. The 3D planned dose (3D-EX), the 3D dose calculated on the average intensity image (3D-AVE), and the 4D accumulations of the dose calculated on the end-exhalation phase CT (4D-PR-EX), the mid-ventilation phase CT (4D-PR-MID), and the average intensity image (4D-PR-AVE), respectively, were compared against the accumulation of the Monte Carlo dose recalculated on every phase. Plan evaluation metrics relating to target volumes and critical structures relevant for lung SBRT were analyzed. Results: Plan evaluation metrics tabulated using 4D-PR-EX, 4D-PR-MID, and 4D-PR-AVE differed from those tabulated using Monte Carlo recalculation on every phase by an average of 0.140.70 Gy, - 0.110.51 Gy, and 0.000.62 Gy, respectively. Deviations of between 8 and 13 Gy were observed between the 4D-MC calculations and both 3D methods for the proximal bronchial trees of 3 patients. Conclusions: 4D dose accumulation using projection without re-calculation may be sufficiently accurate compared to 4D dose accumulated from Monte Carlo recalculation on every phase, depending on institutional protocols. Use of 4D dose accumulation should be considered when evaluating normal tissue complication probabilities as well as in clinical situations where target volumes are directly inferior to mobile critical structures.

  1. NEW PERSPECTIVE ON GALAXY OUTFLOWS FROM THE FIRST DETECTION OF BOTH INTRINSIC AND TRAVERSE METAL-LINE ABSORPTION

    SciTech Connect (OSTI)

    Kacprzak, Glenn G.; Cooke, Jeff; Martin, Crystal L.; Ho, Stephanie H.; Bouch, Nicolas; LeReun, Audrey; Schroetter, Ilane; Churchill, Christopher W.; Klimek, Elizabeth

    2014-09-01

    We present the first observation of a galaxy (z = 0.2) that exhibits metal-line absorption back-illuminated by the galaxy (down-the-barrel) and transversely by a background quasar at a projected distance of 58 kpc. Both absorption systems, traced by Mg II, are blueshifted relative to the galaxy systemic velocity. The quasar sight line, which resides almost directly along the projected minor axis of the galaxy, probes Mg I and Mg II absorption obtained from the Keck/Low Resolution Imaging Spectrometer as well as Ly?, Si II, and Si III absorption obtained from the Hubble Space Telescope/Cosmic Origins Spectrograph. For the first time, we combine two independent models used to quantify the outflow properties for down-the-barrel and transverse absorption. We find that the modeled down-the-barrel deprojected outflow velocities range between V {sub dtb} = 45-255 km s{sup 1}. The transverse bi-conical outflow model, assuming constant-velocity flows perpendicular to the disk, requires wind velocities V {sub outflow} = 40-80 km s{sup 1} to reproduce the transverse Mg II absorption kinematics, which is consistent with the range of V {sub dtb}. The galaxy has a metallicity, derived from H? and N II, of [O/H] = 0.21 0.08, whereas the transverse absorption has [X/H] = 1.12 0.02. The galaxy star formation rate is constrained between 4.6-15 M {sub ?} yr{sup 1} while the estimated outflow rate ranges between 1.6-4.2 M {sub ?} yr{sup 1} and yields a wind loading factor ranging between 0.1-0.9. The galaxy and gas metallicities, the galaxy-quasar sight-line geometry, and the down-the-barrel and transverse modeled outflow velocities collectively suggest that the transverse gas originates from ongoing outflowing material from the galaxy. The ?1 dex decrease in metallicity from the base of the outflow to the outer halo suggests metal dilution of the gas by the time it reached 58 kpc.

  2. In Memoriam

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In Memoriam In Memoriam Honoring Los Alamos National Laboratory Fellows and their contributions to the institution. Llewellyn (Lew) Jones (Pioneer in Vibrational Spectroscopy Field) Llewellyn (Lew) Jones, died June 7, 2014, at his home in Albuquerque. He was 94. A Laboratory Fellow and U.S. Army veteran, Jones was a postdoc at the University of Rochester before joining the Laboratory in 1951 in the former Chemistry-Metallurgy Fowler Division. He retired in 1986 from the former Isotope and

  3. DISCOVERIES IN

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    DISCOVERIES IN ENERGY & ENVIRONMENT 1 The 1,000 scientists, engineers, and professional staff in the Energy and Environment Directorate at Pacific Northwest National Laboratory are intent in our pursuit of answers to the nation's most challenging problems. Our mission is unique in its diversity, from discovering efficient sources of renewable energy to providing scientifically defensible solutions for legacy nuclear waste at the Hanford Site. Success for us means working with partners to

  4. OPPORTUNITIES IN

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    OPPORTUNITIES IN or more than 50 years Los Alamos National Laboratory has designed, built, and analyzed data from instrumentation for space missions both near and far: * satellites circling Earth to help ensure our nation's security; * discovering the processes that govern the space environments of the Sun, Earth, and planets * discovering the composition of the Moon, Mars, and asteroids * capturing the most distant, most powerful cosmic explosions. Los Alamos space payloads and ground-based

  5. Geothermal Prospects in Colorado

    Broader source: Energy.gov [DOE]

    Geothermal Prospects in Colorado presentation at the April 2013 peer review meeting held in Denver, Colorado.

  6. Understanding pop-ins in spherical nanoindentation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Pathak, Siddhartha; Riesterer, Jessica L.; Kalidindi, Surya R.; Michler, Johann

    2014-10-24

    In this study, pop-ins, or sudden displacement-bursts at constant load in a nanoindentation test, are typically attributed to the difficulty of setting up potent dislocation sources in the very small indentation zones in these experiments. Such displacement (and strain) bursts would intuitively indicate a sharp drop in stress during the pop-in event itself. However, spherical indentation stress-strain curves routinely exhibit a high and stable indentation stress value during the pop-in, and the indentation stresses decrease only after a further finite amount of additional indentation displacement has been applied. In order to understand this discrepancy, we utilize a combination of interruptedmore » spherical indentation tests along with depth profiling of the residual indentation surfaces using in-situ atomic force microscopy (AFM) to study pop-ins. The AFM surface profile maps show that there is an asymmetric profile change over a limited region around the indentation contact area for a single pop-in; the asymmetry disappears upon further loading beyond the pop-in. A plausible sequence of physical processes (related to metal plasticity) occurring underneath the indenter during and immediately after the occurrence of the pop-in is proposed to explain these observations.« less

  7. Developments in oil shale in 1987

    SciTech Connect (OSTI)

    Knutson, C.F.; Dana, G.F.; Solti, G.; Qian, J.L.; Ball, F.D.; Hutton, A.C.; Hanna, J.; Russell, P.L.; Piper, E.M.

    1988-10-01

    Oil shale development continued at a slow pace in 1987. The continuing interest in this commodity is demonstrated by the 342 oil shale citations added to the US Department of Energy Energy Database during 1987. The Unocal project in Parachute, Colorado, produced 600,000 bbl of synfuel in 1987. An appreciable amount of 1987's activity was associated with the nonsynfuel uses of oil shale. 4 figs., 2 tabs.

  8. Fire In The Ice

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Fire in the Ice The methane hydrate newsletter, Fire in the Ice, is a quarterly publication highlighting the latest developments in international gas hydrates R&D. Fire in the Ice promotes the exchange of information amoung those involved in gas hydrates research and development, and also recognizes the efforts of a hydrate researcher in each issue. The newsletter now reaches nearly 1300 scientists and other interested individuals in sixteen countries. To subscribe electronically to Fire in

  9. Eliminating MTBE in Gasoline in 2006

    Reports and Publications (EIA)

    2006-01-01

    A review of the market implications resulting from the rapid change from methyl tertiary butyl ether (MTBE) to ethanol-blended reformulated gasoline (RFG) on the East Coast and in Texas. Strains in ethanol supply and distribution will increase the potential for price volatility in these regions this summer.

  10. State Experience in Hydrogen Infrastructure in California

    Broader source: Energy.gov [DOE]

    Presentation by Gerhard Achtelik, California Air Resources Board, at the Hydrogen Infrastructure Market Readiness Workshop, February 17, 2011, in Washington, DC.

  11. Eliminating MTBE in Gasoline in 2006

    Gasoline and Diesel Fuel Update (EIA)

    in 2006. Companies' decisions to eliminate MTBE have been driven by State bans due to water contamination concerns, continuing liability exposure from adding MTBE to gasoline,...

  12. Feed-in-Tariff

    Broader source: Energy.gov [DOE]

    Note: In August of 2013 the Hawaii Public Utility Commission (PUC) initiated an investigation into the Feed-In-Tariff Program in Docket No. 2013-0194. On December 5th, 2014 the Hawaii PUC issued...

  13. Fraud Detection in Healthcare

    SciTech Connect (OSTI)

    Chandola, Varun; Schryver, Jack C; Sukumar, Sreenivas R

    2015-01-01

    We discuss the problem of fraud detection in healthcare in this chapter. Given the recent scrutiny of the ineciencies in the US healthcare system, identifying fraud has been on the forefront of the eorts towards reducing the healthcare costs. In this chapter we will focus on understanding the issue of healthcare fraud in detail, and review methods that have been proposed in the literature to combat this issue using data driven approach.

  14. Focusing in Linear Accelerators

    DOE R&D Accomplishments [OSTI]

    McMillan, E. M.

    1950-08-24

    Review of the theory of focusing in linear accelerators with comments on the incompatibility of phase stability and first-order focusing in a simple accelerator.

  15. Trends in stationary energy

    Broader source: Energy.gov [DOE]

    Trends in Stationary Energy Lunch Presentation for the 2013 Building Technologies Office's Program Peer Review

  16. Trends in stationary energy

    SciTech Connect (OSTI)

    2013-04-01

    Trends in Stationary Energy Lunch Presentation for the 2013 Building Technologies Office's Program Peer Review

  17. RESEARCH IN PARTICLE PHYSICS

    SciTech Connect (OSTI)

    Kearns, Edward

    2013-07-12

    This is the final report for the Department of Energy Grant to Principal Investigators in Experimental and Theoretical Particle Physics at Boston University. The research performed was in the Energy Frontier at the LHC, the Intensity Frontier at Super-Kamiokande and T2K, the Cosmic Frontier and detector R&D in dark matter detector development, and in particle theory.

  18. In situ reactor

    DOE Patents [OSTI]

    Radtke, Corey William; Blackwelder, David Bradley

    2004-01-27

    An in situ reactor for use in a geological strata, is described and which includes a liner defining a centrally disposed passageway and which is placed in a borehole formed in the geological strata; and a sampling conduit is received within the passageway defined by the liner and which receives a geological specimen which is derived from the geological strata, and wherein the sampling conduit is in fluid communication with the passageway defined by the liner.

  19. Frontiers in Science Archive

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Frontiers in Science Lectures » Frontiers in Science Archive Frontiers in Science Archive x LInda Anderman (505) 665-9196 Email The Frontiers in Science lecture series are a public service of the Los Alamos National Laboratory Fellows. Fellows are appointed by the Laboratory Director in recognition of sustained outstanding contributions and exceptional promise for continued professional achievement. All lectures are open to the public and free of charge. PAST LECTURES 2015 August Beyond Pluto:

  20. Energy in density gradient

    SciTech Connect (OSTI)

    Vranjes, J.; Kono, M.

    2015-01-15

    Inhomogeneous plasmas and fluids contain energy stored in inhomogeneity and they naturally tend to relax into lower energy states by developing instabilities or by diffusion. But the actual amount of energy in such inhomogeneities has remained unknown. In the present work, the amount of energy stored in a density gradient is calculated for several specific density profiles in a cylindrical configuration. This is of practical importance for drift wave instability in various plasmas, and, in particular, in its application in models dealing with the heating of solar corona because the instability is accompanied with stochastic heating, so the energy contained in inhomogeneity is effectively transformed into heat. It is shown that even for a rather moderate increase of the density at the axis in magnetic structures in the corona by a factor 1.5 or 3, the amount of excess energy per unit volume stored in such a density gradient becomes several orders of magnitude greater than the amount of total energy losses per unit volume (per second) in quiet regions in the corona. Consequently, within the life-time of a magnetic structure such energy losses can easily be compensated by the stochastic drift wave heating.

  1. Dust Measurements in Tokamaks

    SciTech Connect (OSTI)

    Rudakov, D; Yu, J; Boedo, J; Hollmann, E; Krasheninnikov, S; Moyer, R; Muller, S; Yu, A; Rosenberg, M; Smirnov, R; West, W; Boivin, R; Bray, B; Brooks, N; Hyatt, A; Wong, C; Fenstermacher, M; Groth, M; Lasnier, C; McLean, A; Stangeby, P; Ratynskaia, S; Roquemore, A; Skinner, C; Solomon, W M

    2008-04-23

    Dust production and accumulation impose safety and operational concerns for ITER. Diagnostics to monitor dust levels in the plasma as well as in-vessel dust inventory are currently being tested in a few tokamaks. Dust accumulation in ITER is likely to occur in hidden areas, e.g. between tiles and under divertor baffles. A novel electrostatic dust detector for monitoring dust in these regions has been developed and tested at PPPL. In DIII-D tokamak dust diagnostics include Mie scattering from Nd:YAG lasers, visible imaging, and spectroscopy. Laser scattering resolves size of particles between 0.16-1.6 {micro}m in diameter; the total dust content in the edge plasmas and trends in the dust production rates within this size range have been established. Individual dust particles are observed by visible imaging using fast-framing cameras, detecting dust particles of a few microns in diameter and larger. Dust velocities and trajectories can be determined in 2D with a single camera or 3D using multiple cameras, but determination of particle size is problematic. In order to calibrate diagnostics and benchmark dust dynamics modeling, pre-characterized carbon dust has been injected into the lower divertor of DIII-D. Injected dust is seen by cameras, and spectroscopic diagnostics observe an increase of carbon atomic, C2 dimer, and thermal continuum emissions from the injected dust. The latter observation can be used in the design of novel dust survey diagnostics.

  2. Mixing in astrophysics

    SciTech Connect (OSTI)

    Fryer, Christopher Lee

    2011-01-07

    Turbulent mixing plays a vital role in many fields in astronomy. Here I review a few of these sites, discuss the importance of this turbulent mixing and the techniques used by astrophysicists to solve these problems.

  3. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    submit In other news Past Platinum Award winner discusses LAESF impact in new podcast; Free admission for active-duty military, family members; High-angle canyon-side legacy...

  4. Scientist in the Spotlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    live in regional fresh water supplies. You'll also have an opportunity to talk to Jane about her interest in microbiology and see cool stuff normally invisible to the human eye...

  5. In Case of Emergency

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In Case of Emergency In Case of Emergency Print FirePolice Emergency: ext. 7911 Cell phone or off-site: 510-486-7911 When dialing from off-site, the following numbers need to be...

  6. Energy Refits in Philadelphia

    Broader source: Energy.gov [DOE]

    The Greater Philadelphia region's historic buildings and homes are among the most significant in American history, but they predate modern energy-efficient designs by centuries. In fact, some...

  7. Energy Use in Manufacturing

    Reports and Publications (EIA)

    2006-01-01

    This report addresses both manufacturing energy consumption and characteristics of the manufacturing economy related to energy consumption. In addition, special sections on fuel switching capacity and energy-management activities between 1998 and 2002 are also featured in this report.

  8. In situ measurement system

    DOE Patents [OSTI]

    Lord, D.E.

    1980-11-24

    A multipurpose in situ underground measurement system comprising a plurality of long electrical resistance elements in the form of rigid reinforcing bars, each having an open loop hairpin configuration of shorter length than the other resistance elements. The resistance elements are arranged in pairs in a unitized structure, and grouted in place in the underground volume. Measurement means are provided for obtaining for each pair the electrical resistance of each element and the difference in electrical resistance of the paired elements, which difference values may be used in analytical methods involving resistance as a function of temperature. A scanner means sequentially connects the resistance-measuring apparatus to each individual pair of elements. A source of heating current is also selectively connectable for heating the elements to an initial predetermined temperature prior to electrical resistance measurements when used as an anemometer.

  9. In the News

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2014 Current ice melt rate in Pine Island Glacier may go on for decades February 4, 2014 Liquid sample AMS patent awarded to CAMS staff December 15, 2013 Change in Pacific...

  10. Unnumbered in cover letter

    Office of Legacy Management (LM)

    ... While it is reasonable that this partitioning process is at equilibrium in the pore space, partitioning to water in the fractured zone, where the fractures are nearly dry, is ...

  11. LPG in Venezuela

    SciTech Connect (OSTI)

    Romero, O.

    1986-01-01

    The use of LPG for domestic consumption in Venezuela began in late 1929 when LPG was imported in lots of 500 cylinders. These cylinders were then returned to the U.S. for refilling. Total consumption at that time was some 40M/sup 3/ (250 barrels) per year and by 1937 had grown to some 540M/sup 3/ (3,400 barrels) per year. Local production of LPG from gas began in the mid thirties with a small cooling plant in the Mene Grande Field in the Lake Maracaibo area, the first field to produce oil in Venezuela (1914). This plant produced gasoline for a refinery and some of the first LPG used in Venezuela for domestic consumption. The capacity of this plant was insufficient to satisfy the growing demand for LPG which was supplied from refinery production until the development of the natural gas processing industry. At the present time, Venezuelan refineries are net consumers of LPG.

  12. PROGRESS IN RESEARCH

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... in our calculation, we compare in Table I, the values of ... Then with this flow, a 300 watt electrical strip heater was ... Table I compares the facility usage by commercial and ...

  13. In Memoriam Archive

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In Memoriam Archive Honoring Los Alamos National Laboratory Fellows and their contributions to the institution. Arthur Nelson Cox Arthur Nelson Cox Arthur Nelson Cox (October 12, 1927-March 12, 2013) Arthur Nelson Cox, noted astrophysicist, author and editor, beloved husband, father, grandfather and great-grandfather, died peacefully in his sleep on March 12, 2013 at St. Vincent's Hospital in Santa Fe. He was 85. Arthur was born on Oct. 12, 1927 in Van Nuys, Calif. to Arthur H. Cox and Sarah

  14. Providing Grid Flexibility in

    Energy Savers [EERE]

    Providing Grid Flexibility in Wyoming and Montana Introduction Powder River Energy Corporation (PRECorp) is an electric cooperative serving approximately 11,900 customers in a 16,200 square-mile area of rural Wyoming and Montana. PRECorp's customers frequently experience harsh weather conditions. Severe weather conditions in PRECorp's rural and remote service territory present unique challenges in providing reliable electric service to PRECorp's customers. PRECorp's customers include coal mining

  15. Frontiers in Science Lectures

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Frontiers in Science Lectures Frontiers in Science Lectures x Linda Anderman (505) 665-9196 Email The Frontiers in Science lecture series are a public service of the Los Alamos National Laboratory Fellows. Fellows are appointed by the Laboratory Director in recognition of sustained outstanding contributions and exceptional promise for continued professional achievement. All lectures are open to the public and free of charge. LATEST LECTURE Hacking Photosynthesis: Growing Plants to Power Our

  16. Frontiers in Science Lectures

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Lectures focus on saving energy through superconductivity June 12, 2009 LOS ALAMOS, New Mexico, June 12, 2009-Los Alamos National Laboratory scientist Dean Peterson discusses the science of high-temperature superconductivity in a series of Frontiers in Science lectures starting June 16 at the Duane W. Smith Auditorium at Los Alamos High School. In the talk, titled "Lost In Transmission: Saving Energy With Superconductivity," Peterson, of the Laboratory's Superconductivity Technology

  17. Women in STEM

    Broader source: Energy.gov [DOE]

    A page showcasing the great contributions of women in the energy sector and encouraging girls to continue studying STEM.

  18. Glueball candidates in hadroproduction

    SciTech Connect (OSTI)

    Chung, S.U.

    1984-01-01

    Glueball candidates in hadron-hadron collision processes are reviewed. So far, candidates have been reported in J/sup PC/ = 0/sup + +/, 2/sup + +/ and 0/sup - +/ but none in the exotic J/sup PC/ such as 1/sup - +/. 23 references.

  19. Natural radionuclides in groundwaters

    SciTech Connect (OSTI)

    Laul, J.C.

    1990-01-01

    The U-234 and Th-230 radionuclides are highly retarded by factors of 10{sup 4} to 10{sup 5} in basalt groundwater (Hanford) and briny groundwaters from Texas and geothermal brine from the Salton Sea Geothermal Field (SSGF). In basalt groundwaters (low ionic strength), Ra is highly sorbed, while in brines (high ionic strength), Ra is soluble. This is probably because the sorption sites are saturated with Na{sup +} and Cl{sup {minus}} ions and RaCl{sub 2} is soluble in brines. Pb-210 is soluble in SSGF brine, probably as a chloride complex. The U-234/Th-230 ratios in basalt groundwaters and brines from Texas and SSGF are nearly unity, indicating that U is in the +4 state, suggesting a reducing environment for these aquifers. 19 refs., 3 figs.

  20. Hyaluronan in human malignancies

    SciTech Connect (OSTI)

    Sironen, R.K.; Department of Pathology, Kuopio University Hospital, P.O. Box 1777, FI-70211 Kuopio ; Tammi, M.; Tammi, R.; Auvinen, P.K.; Anttila, M.; Department of Gynecology and Obstetrics, Kuopio University Hospital, P.O. Box 1777, FI-70211 Kuopio ; Kosma, V-M.

    2011-02-15

    Hyaluronan, a major macropolysaccharide in the extracellular matrix of connective tissues, is intimately involved in the biology of cancer. Hyaluronan accumulates into the stroma of various human tumors and modulates intracellular signaling pathways, cell proliferation, motility and invasive properties of malignant cells. Experimental and clinicopathological evidence highlights the importance of hyaluronan in tumor growth and metastasis. A high stromal hyaluronan content is associated with poorly differentiated tumors and aggressive clinical behavior in human adenocarcinomas. Instead, the squamous cell carcinomas and malignant melanomas tend to have a reduced hyaluronan content. In addition to the stroma-cancer cell interaction, hyaluronan can influence stromal cell recruitment, tumor angiogenesis and epithelial-mesenchymal transition. Hyaluronan receptors, hyaluronan synthases and hyaluronan degrading enzymes, hyaluronidases, are involved in the modulation of cancer progression, depending on the tumor type. Furthermore, intracellular signaling and angiogenesis are affected by the degradation products of hyaluronan. Hyaluronan has also therapeutic implications since it is involved in multidrug resistance.

  1. Shared Space vs. In-Unit Upgrades in Multifamily Buildings |...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Shared Space vs. In-Unit Upgrades in Multifamily Buildings Shared Space vs. In-Unit Upgrades in Multifamily Buildings Better Buildings Neighborhood Program Multifamily Peer ...

  2. Variation in energy available to subsurface anaerobes in response...

    Office of Scientific and Technical Information (OSTI)

    Variation in energy available to subsurface anaerobes in response to geological carbon storage. Citation Details In-Document Search Title: Variation in energy available to ...

  3. Shared Space vs. In-Unit Upgrades in Multifamily Buildings |...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Shared Space vs. In-Unit Upgrades in Multifamily Buildings Shared Space vs. In-Unit Upgrades in Multifamily Buildings Better Buildings Neighborhood Program Multifamily Peer...

  4. Recent Trends in Car Usage in Advanced Economies - Slower Growth...

    Open Energy Info (EERE)

    Trends in Car Usage in Advanced Economies - Slower Growth Ahead? Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Recent Trends in Car Usage in Advanced Economies -...

  5. Spintronics in antiferromagnets

    SciTech Connect (OSTI)

    Soh, Yeong-Ah; Kummamuru, Ravi K.

    2012-05-10

    Magnetic domains and the walls between are the subject of great interest because of the role they play in determining the electrical properties of ferromagnetic materials and as a means of manipulating electron spin in spintronic devices. However, much less attention has been paid to these effects in antiferromagnets, primarily because there is less awareness of their existence in antiferromagnets, and in addition they are hard to probe since they exhibit no net magnetic moment. In this paper, we discuss the electrical properties of chromium, which is the only elemental antiferromagnet and how they depend on the subtle arrangement of the antiferromagnetically ordered spins. X-ray measurement of the modulation wavevector Q of the incommensurate antiferromagnetic spin-density wave shows thermal hysteresis, with the corresponding wavelength being larger during cooling than during warming. The thermal hysteresis in the Q vector is accompanied with a thermal hysteresis in both the longitudinal and Hall resistivity. During cooling, we measure a larger longitudinal and Hall resistivity compared with when warming, which indicates that a larger wavelength at a given temperature corresponds to a smaller carrier density or equivalently a larger antiferromagnetic ordering parameter compared to a smaller wavelength. This shows that the arrangement of the antiferromagnetic spins directly influences the transport properties. In thin films, the sign of the thermal hysteresis for Q is the same as in thick films, but a distinct aspect is that Q is quantized.

  6. Controlled porosity in electrodes

    DOE Patents [OSTI]

    Chiang, Yet-Ming; Bae, Chang-Jun; Halloran, John William; Fu, Qiang; Tomsia, Antoni P.; Erdonmez, Can K.

    2015-06-23

    Porous electrodes in which the porosity has a low tortuosity are generally provided. In some embodiments, the porous electrodes can be designed to be filled with electrolyte and used in batteries, and can include low tortuosity in the primary direction of ion transport during charge and discharge of the battery. In some embodiments, the electrodes can have a high volume fraction of electrode active material (i.e., low porosity). The attributes outlined above can allow the electrodes to be fabricated with a higher energy density, higher capacity per unit area of electrode (mAh/cm.sup.2), and greater thickness than comparable electrodes while still providing high utilization of the active material in the battery during use. Accordingly, the electrodes can be used to produce batteries with high energy densities, high power, or both compared to batteries using electrodes of conventional design with relatively highly tortuous pores.

  7. In Other News

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In Other News Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In Other News New Lab program reinforces safety behavior; Laboratory Fellows announced. January 1, 2013 dummy image Read our archives Contacts Editor Linda Anderman Email Community Programs Office Kurt Steinhaus Email Chuck, Steven, and Mikhail have made exceptional contributions in their fields and to national security. New Lab

  8. In Other News

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Student housing needed and more science stories May 1, 2013 Student housing needed this summer Student housing needed this summer Contact Editor Linda Anderman Email Community Programs Office Kurt Steinhaus Email Summer student housing needed Each year students arrive in the region from all over the country and the world

  9. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Summer activities, new Energy Secretary, contractor awards scholarships and a STEM summit June 1, 2013 Bradbury Science Museum Bradbury Science Museum in Los Alamos Contact Editor Linda Anderman Email Community Programs Office Kurt Steinhaus Email Bradbury Science Museum can help stem summer "brain drain"

  10. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Readers' survey, protecting Lab bird residents and major media mentions December 1, 2013 Community Connections readers' survey Please participate in our readers' survey Contacts Community Programs Office Director Kurt Steinhaus Email Editor Linda Anderman Email Community Connections readers survey - please let your voice

  11. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Science Cinema, crowdfunding and giving programs wrap up February 1, 2014 Crowdsourcing class at UNM-LA The Bradbury Science Museum in Los Alamos Contact Community Programs Office Director Kurt Steinhaus Email Editor Linda Anderman Email Lab supports local business through crowdfunding class A recent crowdfunding course

  12. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news New podcast, Supercomputing winners May 5, 2014 Elmer Torres (r) recently participated in a podcast on Native American entrepreneurs. Here, Torres receives a Native American Venture Acceleration Fund award from Kurt Steinhaus (l), director of the Laboratory's Community Programs Office, and Kathy Keith (m), executive

  13. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Call for Native American VAF applications, new video marks 10 years of collective community giving, entrepreneurship award, new LANL Foundation CEO, national economic development conference November 1, 2014 Elmer Torres (middle), shown here during the grand opening of his Than Povi Fine Art Gallery in Cuyamungue, is one

  14. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Call for Venture Acceleration Fund applications, including information sessions March 5 and 11; opportunity to own a Habitat for Humanity home; Luján and Fleischmann to lead House Nuclear Cleanup Caucus March 1, 2015 FLUTe, a flexible liner manufacturer located in Alcalde, New Mexico, was one of the Venture Acceleration

  15. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Maestas-Swazo named Lab's tribal liaison; new head for DOE's Los Alamos cleanup office; 2015 recipients of Northern New Mexico Tribal Business Scholarship; LANL Laces and school supplies drive invest in students; seven Mexican spotted owl chicks hatch on Lab property; new podcast September 1, 2015 Baxter the Bear of Del

  16. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Los Alamos cancer research highlighted on NBC News; top YouTube videos featuring Los Alamos science; new tribal governors; "New Mexico Women in Science" calendar; Future City winners share visions of the future; Podcast introduces new internship opportunities February 1, 2016 The Pueblo of Pojoaque celebrated

  17. Environmental protection in China

    SciTech Connect (OSTI)

    Russell, M. Univ. of Knoxville, TN )

    1990-01-01

    Environmental conditions in China are dramatically worse than those in the USA, but the Chinese are acting with commendable vigor in attempting to contain and ultimately reverse the damage. The Chinese have air, water and soil contamination, along with garbage and trash problems. They are also experiencing deforestation, desertification, soil erosion, destruction of wildlife habitat and wetlands, and the depletion of ground water. Attempts are being made to reduce the pollutants being produced, but economic factors weigh heavily against cleaning up current pollution.

  18. 2013 Year in Review

    Energy Savers [EERE]

    3 Year in Review i 2013 YIR May 2014 Year-in-Review: 2013 Energy Infrastructure Events and Expansions Infrastructure Security and Energy Restoration Office of Electricity Delivery and Energy Reliability U.S. Department of Energy DOE / 2013 Year in Review ii 2013 YIR For Further Information This report was prepared by the Office of Electricity Delivery and Energy Reliability under the direction of Patricia Hoffman, Assistant Secretary, and William Bryan, Deputy Assistant Secretary. Specific

  19. Small Particles in Cirrus

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Small Modular Reactor Report (SEAB) Small Modular Reactor Report (SEAB) In his April 3, 2012, Memorandum to Secretary of Energy Advisory Board (SEAB) Chairman William Perry, Secretary of Energy Steven Chu charged: "The broad purpose of the SEAB subcommittee on SMRs is to advise the Secretary on ways to advance this technology to achieve a global leadership role in civil nuclear technology for the United States, and ways for DOE to accelerate that role." In the context of the

  20. Scientists in the Spotlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientists in the Spotlight Scientists in the Spotlight WHEN: Dec 12, 2015 11:00 AM - 1:00 PM WHERE: Bradbury Science Museum 1350 Central Ave, Los Alamos, NM 87544, USA CATEGORY: Bradbury INTERNAL: Calendar Login Scientists in the Spotlight Every Second Saturday Event Description MARK YOUR CALENDARS for this special event! Every second Saturday from 11:00 AM to 1:00 PM, the museum features actual scientists and researchers talking to visitors about their favorite STEM (Science, Technology,

  1. Living in Los Alamos

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Living in Los Alamos Living in Los Alamos The enchanting surroundings, extraordinary people, and rich history make Los Alamos so much more than just a place to do great work. Discover the many advantages of living and working in Los Alamos. AROUND LOS ALAMOS Communication KRSN Community Radio Los Alamos Daily Post Los Alamos Monitor Education Los Alamos Public Schools Pajarito Environmental Education Center University of New Mexico - Los Alamos The Arts Fuller Lodge Art Center Los Alamos Little

  2. Future Mobility in Maryland

    National Nuclear Security Administration (NNSA)

    ... repair costs and increased fuel consumption and tire wear. * In the Las Vegas ... development of environmentally-friendly energy sources (NSTPRSC). * Speed up project ...

  3. In Other News

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    is one of the top ways they receive that information. Economic and Business Issues Perceptions about the Lab's economic impact in Northern New Mexico are positive with 62...

  4. Elements in biological AMS

    SciTech Connect (OSTI)

    Vogel, J.S.; McAninch, J.; Freeman, S.

    1996-08-01

    AMS (Accelerator Mass Spectrometry) provides high detection sensitivity for isotopes whose half-lives are between 10 years and 100 million years. {sup 14}C is the most developed of such isotopes and is used in tracing natural and anthropogenic organic compounds in the Earth`s biosphere. Thirty-three elements in the main periodic table and 17 lanthanides or actinides have long lived isotopes, providing potential tracers for research in elemental biochemistry. Overlap of biologically interesting heavy elements and possible AMS tracers is discussed.

  5. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Request for proposals for Venture Acceleration Fund opening soon, news updates on recent STEM activities, a scholarship opportunity for northern New Mexico students, and notice to businesses to register on the System for Award Management March 1, 2016 UbiQD received VAF funding in 2015 UbiQD received VAF funding in 2015.

  6. In the News

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In the News In the News MaRIE will provide a capability to address the control of performance and production of weapons materials at the mesoscale. MaRIE fills a critical gap in length scale between the integral scale addressed by studies conducted at DARHT, U1a, NIF, and Z. In the News Roadmap to MaRIE Los Alamos National Laboratory's proposed MaRIE facility is slated to introduce the world's highest energy hard x-ray free electron laser (XFEL). MaRIE Brochure Recruit (pdf) Roadmap for November

  7. Fuel Cells in Telecommunications

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Fuel Cells Simply Powerful Fuel Cells in Telecommunications J. Blanchard December 2011 - ReliOn Overview Markets Backup, grid supplement, and off grid power systems for critical ...

  8. In-Office Services:

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    3,100 8 Consumer Protection Consumer protection (except for disputes over real estateconstruction matters) 6 Paid-In-Full 350 3 Small Claims Court - Advice and...

  9. Science Activities in Biomass

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    concern plant growth and the environment, byproducts of biomass, and energy contained in different types of biomass. Provided by the Department of Energy's National Renewable...

  10. Lighting in Commercial Buildings

    U.S. Energy Information Administration (EIA) Indexed Site

    energy are presented in this section. Statistics are presented by subgroups based on building characteristics, and by subgroups based on lighting equipment. The three sets of...

  11. ALS in the News

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Request for DOE R&D DOE Scientists Team up to Demonstrate Scientific Potential of Big Data Infrastructure January Timeline Chronicles Lab's Science Highlights in 2014 (...and ...

  12. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Laboratory helps Ohkay Owingeh find math, science tutors; giving students a ... Laboratory helps Ohkay Owingeh find math, science tutors Los Alamos National Laboratory's ...

  13. Penetration in GTA welding

    SciTech Connect (OSTI)

    Heiple, C.R.; Burgardt, P.

    1990-01-01

    The size and shape of the weld bead produced in GTA welding depends on the magnitude and distribution of the energy incident on the workpiece surfaces as well as the dissipation of that energy in the workpiece. The input energy is largely controllable through the welding parameters selected, however the dissipation of that energy in the workpiece is less subject to control. Changes in energy dissipation can produce large changes in weld shape or penetration. Heat transport away from the weld pool is almost entirely by conduction, but heat transport in the weld pool is more complicated. Heat conduction through the liquid is an important component, but heat transport by convection (mass transport) is often the dominant mechanism. Convective heat transport is directional and changes the weld pool shape from that produced by conduction alone. Surface tension gradients are often the dominant forces driving fluid flow in GTA weld pools. These gradients are sensitive functions of weld pool chemistry and the energy input distribution to the weld. Experimental and theoretical work conducted primarily in the past decade has greatly enhanced our understanding of weld pool fluid flow, the forces which drive it, and its effects on weld pool shape. This work is reviewed here. While less common, changes in energy dissipation through the unmelted portion of the workpiece can also affect fusion zone shape or penetration. These effects are also described. 41 refs., 9 figs.

  14. Lighting in Commercial Buildings

    U.S. Energy Information Administration (EIA) Indexed Site

    Motivation and Computation of Lighting Measures Floorspace by Lighting Equipment Configuration As described in Appendix A, for each building b, the CBECS data set has the total...

  15. Flexibility in Testing Configurations

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    allows researchers to address critical issues of PV reliability and power availability. ... expertise in a wide range of fundamental science areas, lab diagnostics, and reliability. ...

  16. Microbial Populations in CAVES

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Microbial Populations in CAVES: A Comparison of Sulfur Biosignatures Annette Summers Engel, Department of Geology and Geophysics Compare Frasassi (Italy) and Lower Kane (Wyoming) ...

  17. Petroleum industry in Iran

    SciTech Connect (OSTI)

    Farideh, A.

    1981-01-01

    This study examines the oil industry in Iran from the early discovery of oil nearly two hundred years ago in Mazandaran (north part) to the development of a giant modern industry in the twentieth century. Chapter I presents a brief historical setting to introduce the reader to the importance of oil in Iran. It focuses on the economic implications of the early oil concessions in the period 1901 to 1951. Chapter II discusses the nationalization of the Iranian oil industry and creation of NIOC in 1951 and the international political and economic implication of these activities. Chapter III explains the activities of NIOC in Iran. Exploration and drilling, production, exports, refineries, natural gas, petrochemicals and internal distributions are studied. Chapter IV discusses the role of the development planning of Iran. A brief presentation of the First Development Plan through the Fifth Development Plan is given. Sources and uses of funds by plan organization during these Five Plans is studied. The Iran and Iraq War is also studied briefly, but the uncertainty of its resolution prevents any close analysis of its impact on the Iranian oil industry. One conclusion, however, is certain; oil has been a vital resource in Iran's past and it will remain the lifetime of its economic development in the future.

  18. Scientists in the Spotlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    talking to visitors about their favorite STEM (Science, Technology, Engineering and Math) topics. Featured in December: Teri Roberts and Isaac Salazar Stop by the Bradbury on...

  19. Caught in the Act

    SciTech Connect (OSTI)

    Stocks, G. Malcolm; Morris, James; Sproles, Andrew; Henson, Priscilla; Graham, Kathy

    2013-07-18

    Representing the Center for Defect Physics (CDP), this document is one of the entries in the Ten Hundred and One Word Challenge. As part of the challenge, the 46 Energy Frontier Research Centers were invited to represent their science in images, cartoons, photos, words and original paintings, but any descriptions or words could only use the 1000 most commonly used words in the English language, with the addition of one word important to each of the EFRCs and the mission of DOE: energy. The mission of the CDP is to enhance our fundamental understanding of defects, defect interactions, and defect dynamics that determine the performance of structural materials in extreme environments.

  20. Innovation Concepts in Healthcare

    SciTech Connect (OSTI)

    2011-01-06

    AbstractDemographic change and advances in medical science pose increased challenges to healthcare systems globally: The economic basis is aging and thus health is becoming more and more a productivity factor. At the same time, with today’s new communication possibilities the demand and expectations of effective medical treatment have been increased. This presentation will illustrate the need for the “industrialization” of healthcare in order to achieve highest results at limited budgets. Thereby, industrialization is not meaning the medical treatment based on the assembly line approach. Rather it is to recognize the cost of medical care as an investment with respective expectations on the return of the investment. Innovations in imaging and pharmaceutical products as well as in processes - that lead to similar medical results, but with lower efforts - are keys in such scenarios.BiographyProf. Dr. Hermann Requardt, 54, is a member of the Managing Board of Siemens AG and Chief Executive Officer of the Healthcare Sector. In addition he is the CTO of Siemens AG and Head of Corporate Technology, the central research department at Siemens.After completing his studies in physics and philosophy at the Darmstadt University of Technology and Johann Wolfgang Goethe University in Frankfurt and receiving a doctorate in biophysics, he worked at the Institute of Aerospace Medicine at the German Aerospace Center.In 1984 he joined the Medical Technology Group of Siemens AG, where he was responsible for projects in the Magnetic Resonance (MR) division. He was appointed head of the division in 1995. From 2001 to 2006, as a member of the Executive Management of the Medical Solutions Group, he was responsible for several areas, including technological development.In 2006 he became a Member of the Siemens’ Managing Board and head of Corporate Technology. He was additionally appointed as the Sector Healthcare CEO in 2008.Since 2006 he is an honorary professor in physics of the Johann Wolfgang Goethe University in Frankfurt.                                                                                

  1. Lighting in Commercial Buildings

    U.S. Energy Information Administration (EIA) Indexed Site

    more comprehensive understanding of commercial lighting and the potential for lighting energy savings. Steps to build on this analysis can be taken in many directions. One...

  2. Ventilation in Multifamily Buildings

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... potential problems and to advance industry knowledge 34 Educate End Users * ... - Video Inspection Blocked ducts 55 Beer in ducts Dirty ducts Retrofit Process - ...

  3. Trends in Particulate Nanostructure

    Broader source: Energy.gov [DOE]

    This work attempts to explain the differences in the physical characteristics (nanostructure) of the soot across platforms, heavy-duty and light-duty, and biodiesel blend level.

  4. In the News

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    neutrons at energies comparable to those produced in the deuterium-tritium fusion reactions that power a hydrogen bomb. (Science) March 8, 2016 Livermore Lab physicist selected ...

  5. LPG in Mexico

    SciTech Connect (OSTI)

    Miles, E.L.

    1986-01-01

    The authors review LPG in Mexico. They attempt to project numbers to the year 2000 using a supply/demand comparison.

  6. Adventures in Infectious Diseases

    ScienceCinema (OSTI)

    Fisher-Hoch, Susan [University of Texas School of Public Health

    2014-06-25

    Dr. Susan Fisher-Hoch, Virologist and Epidemiologist, will discuss her research and travels associated with viral hemorrhagic fevers. From the Ebola outbreak in Reston, Virginia to outbreaks of Crimean Congo Hemorrhagic Fever in South Africa, Senegal, and Saudi Arabia, Dr. Fisher-Hoch has studied and tracked the pathophysiology of these viral diseases. These studies have led her from the Center for Disease Control in the United States, to Lyon, France where she was instrumental in designing, constructing, and rendering operational a laboratory capable of containing some of the world's most dangerous diseases.

  7. In The News Feed

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    tion-affordable-alternative-platinum

    Microwave heat improves nanostructured molybdenum disulfide catalyst's ability to produce hydrogen.

    October 26, 2015 In The News Feed...

  8. Innovation Concepts in Healthcare

    ScienceCinema (OSTI)

    None

    2011-04-25

    AbstractDemographic change and advances in medical science pose increased challenges to healthcare systems globally: The economic basis is aging and thus health is becoming more and more a productivity factor. At the same time, with today?s new communication possibilities the demand and expectations of effective medical treatment have been increased. This presentation will illustrate the need for the ?industrialization? of healthcare in order to achieve highest results at limited budgets. Thereby, industrialization is not meaning the medical treatment based on the assembly line approach. Rather it is to recognize the cost of medical care as an investment with respective expectations on the return of the investment. Innovations in imaging and pharmaceutical products as well as in processes - that lead to similar medical results, but with lower efforts - are keys in such scenarios.BiographyProf. Dr. Hermann Requardt, 54, is a member of the Managing Board of Siemens AG and Chief Executive Officer of the Healthcare Sector. In addition he is the CTO of Siemens AG and Head of Corporate Technology, the central research department at Siemens.After completing his studies in physics and philosophy at the Darmstadt University of Technology and Johann Wolfgang Goethe University in Frankfurt and receiving a doctorate in biophysics, he worked at the Institute of Aerospace Medicine at the German Aerospace Center.In 1984 he joined the Medical Technology Group of Siemens AG, where he was responsible for projects in the Magnetic Resonance (MR) division. He was appointed head of the division in 1995. From 2001 to 2006, as a member of the Executive Management of the Medical Solutions Group, he was responsible for several areas, including technological development.In 2006 he became a Member of the Siemens? Managing Board and head of Corporate Technology. He was additionally appointed as the Sector Healthcare CEO in 2008.Since 2006 he is an honorary professor in physics of the Johann Wolfgang Goethe University in Frankfurt.                                                                                

  9. ALS in the News

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    techniques.) (Images by Lomvardas lab) Searching for the Solar System's Chemical Recipe Print Wednesday, 20 February 2013 00:00 The ratio of isotopes in elements like oxygen,...

  10. In-Process Characterization

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    gamma radiation contour maps showing source locations and relative radiological contamination levels present. SRNL GrayQb(tm) Single Faced, Version 2 (SF2) PSP plate (shown in...

  11. Spin waves in the (

    SciTech Connect (OSTI)

    Lipscombe, O. J.; Chen, G. F.; Fang, Chen; Perring, T. G.; Abernathy, Douglas L; Christianson, Andrew D; Egami, Takeshi; Wang, Nanlin; Hu, Jiangping; Dai, Pengcheng

    2011-01-01

    We use neutron scattering to show that spin waves in the iron chalcogenide Fe{sub 1.05}Te display novel dispersion clearly different from both the first principles density functional calculations and recent observations in the related iron pnictide CaFe{sub 2}As{sub 2}. By fitting to a Heisenberg Hamiltonian, we find that although the nearest-neighbor exchange couplings in the two systems are quite different, their next-nearest-neighbor (NNN) couplings are similar. This suggests that superconductivity in the pnictides and chalcogenides share a common magnetic origin that is intimately associated with the NNN magnetic coupling between the irons.

  12. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    All Issues submit In other news Environmental sustainability, Science Bowl winners and ... Community Programs Office Kurt Steinhaus Email 2013 Site Sustainability Plan released The ...

  13. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    All Issues submit In other news New Mexico helps Fukushima; 2014 VAF winners; new ... Editor Ute Haker Email New Mexico helps the Fukushima nuclear reactors A new technology ...

  14. Error Reduction in Weigh-In-Motion

    Energy Science and Technology Software Center (OSTI)

    2007-09-21

    Federal and State agencies need certifiable vehicle weights for various applications, such as highway inspections, border security, check points, and port entries. ORNL weigh-in-motion (WIM) technology was previously unable to provide certifiable weights, due to natural oscillations, such as vehicle bounding and rocking. Recent ORNL work demonstrated a novel filter to remove these oscillations. This work shows further filtering improvements to enable certifiable weight measurements (error < 0.1%) for a higher traffic volume with lessmore » effort (elimination of redundant weighing)« less

  15. Matter in transition

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Anderson, Lara B.; Gray, James; Raghuram, Nikhil; Taylor, Washington

    2016-04-13

    In this study, we explore a novel type of transition in certain 6D and 4D quantum field theories, in which the matter content of the theory changes while the gauge group and other parts of the spectrum remain invariant. Such transitions can occur, for example, for SU(6) and SU(7) gauge groups, where matter fields in a three-index antisymmetric representation and the fundamental representation are exchanged in the transition for matter in the two-index antisymmetric representation. These matter transitions are realized by passing through superconformal theories at the transition point. We explore these transitions in dual F-theory and heterotic descriptions, wheremore » a number of novel features arise. For example, in the heterotic description the relevant 6D SU(7) theories are described by bundles on K3 surfaces where the geometry of the K3 is constrained in addition to the bundle structure. On the F-theory side, non-standard representations such as the three-index antisymmetric representation of SU(N) require Weierstrass models that cannot be realized from the standard SU(N) Tate form. We also briefly describe some other situations, with groups such as Sp(3), SO(12), and SU(3), where analogous matter transitions can occur between different representations. For SU(3), in particular, we find a matter transition between adjoint matter and matter in the symmetric representation, giving an explicit Weierstrass model for the F-theory description of the symmetric representation that complements another recent analogous construction.« less

  16. Renewable Energy in Alaska

    SciTech Connect (OSTI)

    Not Available

    2013-03-01

    This report examines the opportunities, challenges, and costs associated with renewable energy implementation in Alaska and provides strategies that position Alaska's accumulating knowledge in renewable energy development for export to the rapidly growing energy/electric markets of the developing world.

  17. Topics in quarkonium physics

    SciTech Connect (OSTI)

    Quigg, C.

    1983-02-01

    The state of hadron spectroscopy in general and of heavy quark-antiquark bound states in particular is briefly reviewed. The first lecture is devoted to a summary of elementary techniques of quarkonium quantum mechanics. The second is concerned with inverse-scattering techniques. Throughout, the implications of recent data are assessed.

  18. Polyhydroxyalkanoate synthesis in plants

    DOE Patents [OSTI]

    Srienc, Friedrich; Somers, David A.; Hahn, J. J.; Eschenlauer, Arthur C.

    2000-01-01

    Novel transgenic plants and plant cells are capable of biosynthesis of polyhydroxyalkanoate (PHA). Heterologous enzymes involved in PHA biosynthesis, particularly PHA polymerase, are targeted to the peroxisome of a transgenic plant. Transgenic plant materials that biosynthesize short chain length monomer PHAs in the absence of heterologous .beta.-ketothiolase and acetoacetyl-CoA reductase are also disclosed.

  19. Genetics in the courts

    SciTech Connect (OSTI)

    Coyle, Heather; Drell, Dan

    2000-12-01

    Various: (1)TriState 2000 Genetics in the Courts (2) Growing impact of the new genetics on the courts (3)Human testing (4) Legal analysis - in re G.C. (5) Legal analysis - GM ''peanots'', and (6) Legal analysis for State vs Miller

  20. Year in review 2004

    SciTech Connect (OSTI)

    None, None

    2005-01-01

    The federal government must lead the way in reducing its energy consumption and related environmental impacts so that the rest of the country will follow our example. For this reason we often look to our leaders -- energy champions who are providing the innovation and dedication to overcome challenges in pursuing sound energy management.

  1. Mechanisms in Plant Development

    SciTech Connect (OSTI)

    Hake, Sarah

    2013-08-21

    This meeting has been held every other year for the past twenty-two years and is the only regularly held meeting focused specifically on plant development. Topics covered included: patterning in developing tissues; short and long distance signaling; differentiation of cell types; the role of epigenetics in development; evolution; growth.

  2. Coal in China

    SciTech Connect (OSTI)

    Minchener, A.J.

    2005-07-01

    The article gives an overview of the production and use of coal in China, for power generation and in other sectors. Coal use for power generation was 850 million tonnes in 2003 and 800 million tonnes in the non-power sector. The majority of power will continue to be produced from coal, with a trend towards new larger pulverised coal fired units and introduction of circulating fluidised bed combustors. Stricter regulations are forcing introduction of improved pollution control technologies. It seems likely that China will need international finance to supplement private and state investment to carry out a programme to develop and apply clean coal technologies. The author concludes that there is evidence of a market economy being established but there is a need to resolve inconsistencies with the planned aspects of the economy and that additional policies are needed in certain sectors to achieve sustainable development. 1 ref., 2 figs., 2 tabs.

  3. Nuclear Power in Space

    DOE R&D Accomplishments [OSTI]

    1994-01-01

    In the early years of the United States space program, lightweight batteries, fuel cells, and solar modules provided electric power for space missions. As missions became more ambitious and complex, power needs increased and scientists investigated various options to meet these challenging power requirements. One of the options was nuclear energy. By the mid-1950s, research had begun in earnest on ways to use nuclear power in space. These efforts resulted in the first radioisotope thermoelectric generators (RTGs), which are nuclear power generators build specifically for space and special terrestrial uses. These RTGs convert the heat generated from the natural decay of their radioactive fuel into electricity. RTGs have powered many spacecraft used for exploring the outer planets of the solar system and orbiting the sun and Earth. They have also landed on Mars and the moon. They provide the power that enables us to see and learn about even the farthermost objects in our solar system.

  4. Tabled Execution in Scheme

    SciTech Connect (OSTI)

    Willcock, J J; Lumsdaine, A; Quinlan, D J

    2008-08-19

    Tabled execution is a generalization of memorization developed by the logic programming community. It not only saves results from tabled predicates, but also stores the set of currently active calls to them; tabled execution can thus provide meaningful semantics for programs that seemingly contain infinite recursions with the same arguments. In logic programming, tabled execution is used for many purposes, both for improving the efficiency of programs, and making tasks simpler and more direct to express than with normal logic programs. However, tabled execution is only infrequently applied in mainstream functional languages such as Scheme. We demonstrate an elegant implementation of tabled execution in Scheme, using a mix of continuation-passing style and mutable data. We also show the use of tabled execution in Scheme for a problem in formal language and automata theory, demonstrating that tabled execution can be a valuable tool for Scheme users.

  5. Proteolysis in hyperthermophilic microorganisms

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ward, Donald E.; Shockley, Keith R.; Chang, Lara S.; Levy, Ryan D.; Michel, Joshua K.; Conners, Shannon B.; Kelly, Robert M.

    2002-01-01

    Proteases are found in every cell, where they recognize and break down unneeded or abnormal polypeptides or peptide-based nutrients within or outside the cell. Genome sequence data can be used to compare proteolytic enzyme inventories of different organisms as they relate to physiological needs for protein modification and hydrolysis. In this review, we exploit genome sequence data to compare hyperthermophilic microorganisms from the euryarchaeotal genus Pyrococcus , the crenarchaeote Sulfolobus solfataricus , and the bacterium Thermotoga maritima . An overview of the proteases in these organisms is given based on those proteases that have been characterized and on putativemore » proteases that have been identified from genomic sequences, but have yet to be characterized. The analysis revealed both similarities and differences in the mechanisms utilized for proteolysis by each of these hyperthermophiles and indicated how these mechanisms relate to proteolysis in less thermophilic cells and organisms.« less

  6. Conditional sterility in plants

    DOE Patents [OSTI]

    Meagher, Richard B.; McKinney, Elizabeth; Kim, Tehryung

    2010-02-23

    The present disclosure provides methods, recombinant DNA molecules, recombinant host cells containing the DNA molecules, and transgenic plant cells, plant tissue and plants which contain and express at least one antisense or interference RNA specific for a thiamine biosynthetic coding sequence or a thiamine binding protein or a thiamine-degrading protein, wherein the RNA or thiamine binding protein is expressed under the regulatory control of a transcription regulatory sequence which directs expression in male and/or female reproductive tissue. These transgenic plants are conditionally sterile; i.e., they are fertile only in the presence of exogenous thiamine. Such plants are especially appropriate for use in the seed industry or in the environment, for example, for use in revegetation of contaminated soils or phytoremediation, especially when those transgenic plants also contain and express one or more chimeric genes which confer resistance to contaminants.

  7. Irradiation Creep in Graphite

    SciTech Connect (OSTI)

    Ubic, Rick; Butt, Darryl; Windes, William

    2014-03-13

    An understanding of the underlying mechanisms of irradiation creep in graphite material is required to correctly interpret experimental data, explain micromechanical modeling results, and predict whole-core behavior. This project will focus on experimental microscopic data to demonstrate the mechanism of irradiation creep. High-resolution transmission electron microscopy should be able to image both the dislocations in graphite and the irradiation-induced interstitial clusters that pin those dislocations. The team will first prepare and characterize nanoscale samples of virgin nuclear graphite in a transmission electron microscope. Additional samples will be irradiated to varying degrees at the Advanced Test Reactor (ATR) facility and similarly characterized. Researchers will record microstructures and crystal defects and suggest a mechanism for irradiation creep based on the results. In addition, the purchase of a tensile holder for a transmission electron microscope will allow, for the first time, in situ observation of creep behavior on the microstructure and crystallographic defects.

  8. Quantum interference in polyenes

    SciTech Connect (OSTI)

    Tsuji, Yuta; Hoffmann, Roald; Movassagh, Ramis; Datta, Supriyo

    2014-12-14

    The explicit form of the zeroth Green's function in the Hckel model, approximated by the negative of the inverse of the Hckel matrix, has direct quantum interference consequences for molecular conductance. We derive a set of rules for transmission between two electrodes attached to a polyene, when the molecule is extended by an even number of carbons at either end (transmission unchanged) or by an odd number of carbons at both ends (transmission turned on or annihilated). These prescriptions for the occurrence of quantum interference lead to an unexpected consequence for switches which realize such extension through electrocyclic reactions: for some specific attachment modes the chemically closed ring will be the ON position of the switch. Normally the signs of the entries of the Green's function matrix are assumed to have no physical significance; however, we show that the signs may have observable consequences. In particular, in the case of multiple probe attachments if coherence in probe connections can be arranged in some cases new destructive interference results, while in others one may have constructive interference. One such case may already exist in the literature.

  9. Crisis in American mining

    SciTech Connect (OSTI)

    Not Available

    1984-05-01

    The crisis in American mining is discussed. The discussion focuses on the outlook for coal in the overall energy picture. Because of the Arab oil embargo of 1973, the Iranian disruption of 1979, and the tenfold increase in oil prices over the past decade, radical changes have taken place in energy supply and demand patterns. Two of the most important of these changes relate to investment. First, large investments have been made in energy-efficient plants, equipment, buildings, and vehicles. Their effect will restrain energy demand growth for the foreseeable future. Second, investments have been made in fuel-switching, from oil to coal and nuclear power. As a result the oil demand at the end of this century will be at approximately the same level as it is today. Natural gas demand is also likely to be flat. Coal demand, on the other hand, is expected to increase steadily over the long term. Recent conditions in the coal industry are reviewed, and a specific 10-year forecast is given.

  10. In situ groundwater bioremediation

    SciTech Connect (OSTI)

    Hazen, Terry C.

    2009-02-01

    In situ groundwater bioremediation of hydrocarbons has been used for more than 40 years. Most strategies involve biostimulation; however, recently bioaugmentation have been used for dehalorespiration. Aquifer and contaminant profiles are critical to determining the feasibility and strategy for in situ groundwater bioremediation. Hydraulic conductivity and redox conditions, including concentrations of terminal electron acceptors are critical to determine the feasibility and strategy for potential bioremediation applications. Conceptual models followed by characterization and subsequent numerical models are critical for efficient and cost effective bioremediation. Critical research needs in this area include better modeling and integration of remediation strategies with natural attenuation.

  11. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Science Showdown in Española draws close to 400 visitors; Monte del Sol Charter School students win top Supercomputing award; Future entrepreneurs develop business savvy; New Community Programs Office podcasts; My small act: Simple actions have a big impact May 1, 2015 An Española student explains a circuit board to a

  12. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Everything you need to know about summer student housing, the new app for Manhattan Project National Historical Park, and more. April 4, 2016 The soon-to-be-released Secret City app will let visitors to downtown Los Alamos see how the landscape looked in the 1940s when it was a key technical area for the Manhattan

  13. Workshop in Cologne

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Trading and Prices in Commodity Markets EIA 2013 Workshop on Financial and Physical Oil Market Linkages Monday, September 23, 2013 Room 2E-069, Forrestal Building 1000 Independence Ave., SW Washington, DC 20585 8:00 a.m. Check-in and Coffee 8:45 a.m. Welcome by Assistant Administrator for Energy Analysis John Conti 9:00 a.m. Opening remarks by EIA Administrator Adam Sieminski Introduction of the Participants 9:15 a.m. Developments in Market Monitoring Presenter: Matthew Hunter, Commodity Futures

  14. Revolution in Detection Affairs

    SciTech Connect (OSTI)

    Stern W.

    2013-11-02

    The detection of nuclear or radioactive materials for homeland or national security purposes is inherently difficult. This is one reason detection efforts must be seen as just one part of an overall nuclear defense strategy which includes, inter alia, material security, detection, interdiction, consequence management and recovery. Nevertheless, one could argue that there has been a revolution in detection affairs in the past several decades as the innovative application of new technology has changed the character and conduct of detection operations. This revolution will likely be most effectively reinforced in the coming decades with the networking of detectors and innovative application of anomaly detection algorithms.

  15. NERSC in the News

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Supernova to be visible for 2 nights September 8, 2011 | Author(s): David Perlman | Source: SF Gate | PTF11kly.png 'Instant Cosmic Classic' Supernova Discovered August 26, 2011 | Source: Slashdot | 3D Map To Compute Matter Distribution In Universe - SDSS Aftermath January 12, 2012 | Source: CrazyEngineers VoiCE | A Stellar Explosion In The Big Dipper's Handle September 3, 2011 | Author(s): Scott Simon | Source: NPR | fireball-particles.jpg Anti-Helium Discovered in the Heart of STAR April 25,

  16. HV in Noble Liquids

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in Noble Liquids 8 Nov 2013 High Voltage Tests for MicroBooNE Byron Lundberg Fermilab presenting for the Collaboration & Task Force 4 1 Friday, November 8, 13 HV in Noble Liquids MicroBooNE Experiment  A liquid argon time projection chamber (LAr TPC) containing 170 tons of liquid argon, and located on the Booster Neutrino Beamline.  MiniBooNE  MicroBooNE 8,#256#wires;#U,V,Y#planes;#3#mm#spacing# 32#PMTs#for#fast#light#collec?ons# @ L A r T F 2 Friday, November 8, 13 HV in Noble

  17. Scientists in the Spotlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientists In the Spotlight Scientists in the Spotlight WHEN: Apr 11, 2015 11:00 AM - 1:00 PM WHERE: Bradbury Science Museum 1350 Central Ave, Los Alamos, New Mexico, USA CONTACT: Jessica Privette 505 667-0375 CATEGORY: Bradbury INTERNAL: Calendar Login Scientists in the Spotlight Event Description MARK YOUR CALENDARS for this special event! Every second Saturday from 11:00 AM to 1:00 PM, the museum has scientists on the floor talking to people about their favorite STEM topics. Join us at the

  18. Scientists in the Spotlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientists In the Spotlight Scientists in the Spotlight WHEN: Aug 08, 2015 10:00 AM - 12:00 PM WHERE: Bradbury Science Museum, 1350 Central Ave, Los Alamos, USA CONTACT: Jessica Privette 505 667-0375 CATEGORY: Bradbury INTERNAL: Calendar Login Scientists in the Spotlight Event Description MARK YOUR CALENDARS for this special event! Every second Saturday from 11:00 AM to 1:00 PM, the museum has scientists on the floor talking to people about their favorite STEM topics. Join us at the museum every

  19. Scientists in the Spotlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientists In the Spotlight Scientists in the Spotlight WHEN: Jun 13, 2015 11:00 AM - 1:00 PM WHERE: Bradbury Science Museum 1350 Central Ave, Los Alamos, USA CONTACT: Jessica Privette 505 667-0375 CATEGORY: Bradbury INTERNAL: Calendar Login Scientists in the Spotlight Event Description MARK YOUR CALENDARS for this special event! Every second Saturday from 11:00 AM to 1:00 PM, the museum has scientists on the floor talking to people about their favorite STEM topics. Join us at the museum every

  20. Scientists in the Spotlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientists In the Spotlight Scientists in the Spotlight WHEN: Mar 14, 2015 11:00 AM - 1:00 PM WHERE: Bradbury Science Museum 1350 Central Ave, Los Alamos, NM 87544, USA CONTACT: Jessica Privette 505 667-0375 CATEGORY: Bradbury INTERNAL: Calendar Login Celebrating Women in Science Event Description MARK YOUR CALENDARS for this special event! Every second Saturday from 11:00 AM to 1:00 PM, the museum has scientists on the floor talking to people about their favorite STEM topics. Join us at the

  1. Scientists in the Spotlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientists In the Spotlight Scientists in the Spotlight WHEN: May 09, 2015 11:00 AM - 1:00 PM WHERE: Bradbury Science Museum 1350 Central Ave, Los Alamos, New Mexico, USA SPEAKER: Steven Hayden, Chemist CONTACT: Jessica Privette 505 667-0375 CATEGORY: Bradbury INTERNAL: Calendar Login scientist in the spotlight series Event Description MARK YOUR CALENDARS for this special event! Every second Saturday from 11:00 AM to 1:00 PM, the museum has scientists on the floor talking to people about their

  2. Scientists in the Spotlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientists in the Spotlight Scientists in the Spotlight WHEN: Nov 14, 2015 11:00 AM - 1:00 PM WHERE: Bradbury Science Museum 1350 Central Ave, Los Alamos, NM 87544, USA CONTACT: Linda Anderman (505) 665-9196 CATEGORY: Bradbury INTERNAL: Calendar Login Scientists in the Spotlight Event Description MARK YOUR CALENDARS for this special event! Every second Saturday from 11:00 AM to 1:00 PM, the museum features actual scientists and researchers talking to visitors about their favorite STEM topics.

  3. Scientists in the Spotlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientists In the Spotlight Scientists in the Spotlight WHEN: Oct 10, 2015 11:00 AM - Feb 12, 2015 1:00 PM WHERE: Bradbury Science Museum 1350 Central Avenue, Los Alamos, New Mexico 87544 USA CONTACT: Jessica Privette 505 667-0375 CATEGORY: Bradbury INTERNAL: Calendar Login Scientists in the Spotlight every Second Saturday Event Description MARK YOUR CALENDARS for this special event! Every second Saturday from 11:00 AM to 1:00 PM, the museum has scientists on the floor talking to people about

  4. Scientists in the Spotlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientists In the Spotlight Scientists in the Spotlight WHEN: Sep 12, 2015 11:00 AM - 1:00 PM WHERE: Bradbury Science Museum 1350 Central Avenue, Los Alamos, New Mexico, 87544 USA CONTACT: Jessica Privette 505 667-0375 CATEGORY: Bradbury INTERNAL: Calendar Login Scientists in the Spotlight every Second Saturday Event Description MARK YOUR CALENDARS for this special event! Every second Saturday from 11:00 AM to 1:00 PM, the museum has scientists on the floor talking to people about their favorite

  5. Logging in to Franklin

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Logging in Logging in to Franklin Interactive Access You can log in to Franklin using SSH (Secure Shell) with the following command from any UNIX, Linux, FreeBSD, etc. command shell or terminal: % ssh -l username franklin.nersc.gov There are a number of SSH-capable clients available for Windows, Mac, and UNIX/Linux machines. NERSC does not support or recommend any particular client. Franklin has 10 login nodes; you will be randomly connected to one of those 10 when you ssh to franklin.nersc.gov.

  6. No Prejudice in Space

    SciTech Connect (OSTI)

    Cotta, R.C.; Gainer, J.S.; Hewett, J.L.; Rizzo, T.G.; /SLAC

    2010-08-26

    We present a summary of recent results obtained from a scan of the 19-dimensional parameter space of the pMSSM and its implications for dark matter searches. We have generated a large set of points in parameter space (which we call 'models') for the 19-parameter CP-conserving pMSSM, where MFV has been assumed. We subjected these models to numerous experimental and theoretical constraints to obtain a set of {approx}68 K models which are consistent with existing data. We attempted to be somewhat conservative in our implementation of these constraints; in particular we only demanded that the relic density of the LSP not be greater than the measured value of {Omega}H{sup 2} for non-baryonic dark matter, rather than assuming that the LSP must account for the entire observed relic density. Examining the properties of the neutralinos in these models, we find that many are relatively pure gauge eigenstates with Higgsinos being the most common, followed by Winos. The relative prevalence of Higgsino and Wino LSPs leads many of our models to have a chargino as nLSP, often with a relatively small mass splitting between this nLSP and the LSP; this has important consequences in both collider and astroparticle phenomenology. We find that, in general, the LSP in our models provides a relatively small ({approx} 4%) contribution to the dark matter, however there is a long tail to this distribution and a substantial number of models for which the LSP makes up all or most of the dark matter. Typically these neutralinos are mostly Binos. Examining the signatures of our models in direct and indirect dark matter detection experiments, we find a wide range of signatures for both cases. In particular, we find a much larger range of WIMP-nucleon cross sections than is found in any particular model of SUSY-breaking. As these cross sections also enter the regions of parameter space suggested by non-SUSY models, it appears that the discovery of WIMPs in direct detection experiments might not be sufficient to determine the correct model of the underlying physics. As a first look at the signatures of these models in indirect detection experiments, we examined whether our models could explain the PAMELA excess in the positron to electron ratio at high energies. We find that there are models which fit the PAMELA data rather well, and some of these have significantly smaller boost factors than generally assumed for a thermal relic. The study of the pMSSM presents exciting new possibilities for SUSY phenomenology. The next few years will hopefully see important discoveries both in colliders and in satellite or ground-based astrophysical experiments. It is important that we follow the data and not our existing prejudices; hopefully this sort of relatively model-independent approach to collider and astrophysical phenomenology can be useful in this regard.

  7. Opportunities in Bond Financing

    Broader source: Energy.gov [DOE]

    Presentation about financial options and opportunities for biogas and fuel cells. Presented by James Dack, Stern Brothers, at the NREL/DOE Biogas and Fuel Cells Workshop held June 11-13, 2012, in Golden, Colorado.

  8. Partners in Success

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    news with others Highlighting the great work being done in Idaho helps secure future missions for Idaho National Laboratory. Read More Editorial Date Sept 10, 2012 By Brad Bugger...

  9. Topics in Hadronic Physics

    SciTech Connect (OSTI)

    Alfred Tang

    2002-08-01

    Hadron production cross sections are calculated in the perturbative QCD frame work. Parton distribution functions are obtained from a strip-soliton model. The fragmentation functions are derived from the Lund model of string breaking.

  10. Coupling in the Tevatron

    SciTech Connect (OSTI)

    Gelfand, N.M.

    1994-12-01

    The performance of the Fermilab Tevatron Collider at the commencement of run Ib was far below expectations. After a frustrating period of several months, a low-{beta} quad downstream of the interaction point at B0 was found to be rolled. This rolled quadrupole coupled the horizontal and vertical motion of the Tevatron beams. It also made matching the beam from the Main Ring to the Tevatron impossible, resulting in emittance blow up on injection. The net result of the roll was a significant reduction in the Tevatron luminosity. When the roll in the quadrupole was corrected the performance of the Tevatron improved dramatically. This note will discuss the experimental data indicating the presence of coupling and subsequent calculations which show how coupling an affect the luminosity. It is not intended to exhaust a discussion of coupling, which hopefully will be understood well enough to be discussed in a subsequent note.

  11. Reduction-in-Force

    Broader source: Energy.gov [DOE]

    Reduction in force (RIF) is a set of regulations and procedures that are used to determine whether an employee keeps his or her present position, or whether the employee has a right to another...

  12. Nanostructures in Skutterudites

    Broader source: Energy.gov [DOE]

    In-situ synthesis by thermodynamic means such as phase segregation, for fabricating skutterudite-based nanocomposites yield robust and stable nanostructure phases likely to survive harsh thermoelectric power generation environments

  13. In Other News

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    we're asking you to take a few minutes out of your super-busy day to let us know what you think of Connections. We're interested in hearing your thoughts about the length of the...

  14. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... (ANSMET) program, which is supported by NASA. "These meteorites can help us understand ... Few of these solar system bodies will be visited by NASA in our lifetimes and this is a ...

  15. Trends in Workplace Charging

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Donofrio Ford Motor Company Trends in Workplace Charging Est EV NA NA approx 21 70-100 Miles: What Types of Chargers are Being Used? Considerations for Campus Installations *...

  16. Requisitions in STRIPES

    Broader source: Energy.gov [DOE]

    This Policy Flash disseminates updated guidance to STRIPES users on the use of requisitions for STRIPES actions. STRIPES users will no longer be required to do a requisition for every action initiated in STRIPES.

  17. Acoustoelectric photoresponse in graphene

    SciTech Connect (OSTI)

    Poole, T.; Bandhu, L.; Nash, G. R.

    2015-03-30

    The acoustoelectric current in graphene has been investigated as a function of illumination, using blue (450?nm) and red (735?nm) light-emitting diodes (LEDs), and surface acoustic wave (SAW) intensity and frequency. The measured acoustoelectric current increases with illumination, more than the measured change in the conductivity of the graphene, whilst retaining a linear dependence on the SAW intensity. The latter is consistent with the interaction between the carriers and SAWs being described by a relatively simple classical relaxation model suggesting that the change in the acoustoelectric current is caused by the effect of the illumination on the electronic properties of the graphene. The increase in the acoustoelectric current is greatest under illumination with the blue LED, consistent with the creation of a hot electron distribution.

  18. Welcome Year in Review

    National Nuclear Security Administration (NNSA)

    Training Meeting Orlando, Florida-May 23-25, 2006 Sponsored by the U.S. Department of Energy & the U.S. Nuclear Regulatory Commission Welcome & Year In Review Peter Dessaules...

  19. (Photosynthesis in intact plants)

    SciTech Connect (OSTI)

    Not Available

    1990-01-01

    Progress in the two years since the last renewal application has been excellent. We have made substantial contributions on both main fronts of the projects, and are particularly happy with the progress of our research on intact plants. The approach of basing our field work on a sound foundation of laboratory studies has enabled is to use methods which provide unambiguous assays of well characterized reactions. We have also made excellent progress in several laboratory studies which will have direct applications in future field work, and have introduced to the laboratory a range of molecular genetics techniques which will allow us to explore new options in the attempt to understand function at the level of molecular structure.

  20. Malaria control in Tanzania

    SciTech Connect (OSTI)

    Yhdego, M.; Majura, P. )

    1988-01-01

    A review of the malaria control programs and the problem encountered in the United Republic of Tanzania since 1945 to the year 1986 is discussed. Buguruni, one of the squatter areas in the city of Dar es Salaam, is chosen as a case study in order to evaluate the economic advantage of engineering methods for the control of malaria infection. Although the initial capital cost of engineering methods may be high, the cost effectiveness requires a much lower financial burden of only about Tshs. 3 million compared with the conventional methods of larviciding and insecticiding which requires more than Tshs. 10 million. Finally, recommendations for the adoption of engineering methods are made concerning the upgrading of existing roads and footpaths in general with particular emphasis on drainage of large pools of water which serve as breeding sites for mosquitoes.

  1. Lighting in Commercial Buildings

    U.S. Energy Information Administration (EIA) Indexed Site

    5.2 152.6 160.5 54.6 Assembly Health Care Lodging Office 0 20 40 60 80 100 120 140 160 180 Energy Information Administration Energy Consumption Series: Lighting in Commercial...

  2. Nucleosynthesis in Thermonuclear Supernovae

    SciTech Connect (OSTI)

    Claudia, Travaglio; Hix, William Raphael

    2013-01-01

    We review our understanding of the nucleosynthesis that occurs in thermonuclear supernovae and their contribution to Galactic Chemical evolution. We discuss the prospects to improve the modeling of the nucleosynthesis within simulations of these events.

  3. Positron identification in APEX

    SciTech Connect (OSTI)

    Kaloskamis, N.I.

    1993-10-01

    The trigger which signals than an event of interest has occurred in APEX is based on the identification of back-to-back 511 keV positron annihilation radiation. The gamma rays are detected in 24- element position sensitive NaI(Tl) barrels which surround each silicon array. The gamma-ray information gives positron identification and allows the reconstruction of the location of the decaying positron on the silicon array. The principle of operation, design and performance will he presented including the energy, time and position resolutions. Examples of in-beam data show the successful suppression of false triggers from room background and beam-induced radiation, resuIting in the unambiguous identification and location of reaction positrons and the clean separation of positrons from the copious background of delta electrons.

  4. NERSC In the News

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    | Author(s): Timothy Stenovec | Source: Huffington Post | Supernova Burns Bright in a Galaxy Not So Far Away September 7, 2011 | Author(s): Jeffrey Brown | Source: PBS News Hour |...

  5. YEAR IN REVIEW

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... to develop a sustain- able, world-class offshore wind indus- try. ... can be created in an entirely new way. Prior to the Strati, 3D printing had been largely used to make ...

  6. Get In Touch - Nercenergy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Get In Touch Want to chat with us? We'd love to hear from you Simply email chat-at-nercenergy.com and we'll get back to you as soon as we can....

  7. Foldtrack in Motion

    Broader source: Energy.gov [DOE]

    Resembling a small bulldozer, Foldtrack is a remotely operated, track-mounted system that uses a plow blade to move radioactive waste from the floor of Hanford's underground storage tanks. In...

  8. In The News Feed

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    -just-won-t-die-1.18685 November 4, 2015 In The News Feed Perspective: The energy-storage revolution http:www.nature.comnaturejournalv526n7575suppfull526S92a.html November...

  9. Nelson's syndrome in pregnancy

    SciTech Connect (OSTI)

    Surrey, E.S.; Chang, R.J.

    1985-10-01

    The therapeutic considerations in the management of Nelson's syndrome in a 29 year old primigravida are described. CT scans revealed a 2-cm solid pituitary lesion with suprasellar extension and chiasmatic encroachment. A transsphenoidal hypophysectomy was performed to remove a eosinophilic pituitary adenoma. The patient's symptoms improved following surgery. Fetal growth was followed by ultrasound and a female infant was delivered by cesarean section. Follow-up CT scan 2 weeks after delivery revealed no evidence of tumor recurrence.

  10. Volcanoes in Virginia!

    ScienceCinema (OSTI)

    Johnson, Elizabeth Baedke [James Madison University

    2014-06-25

    The recent earthquake may have you wondering what other surprises Virginia's geology may hold. Could there be a volcanic eruption in Virginia? Probably not today, but during the Eocene, about 35-48 million years ago, a number of mysterious eruptions occurred in western Virginia. This talk investigates the possible origins of these eruptions, and what they can tell us about the crust and mantle underneath Virginia.

  11. In Other News

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Energy Industries That Are Driving American Manufacturing Growth | Department of Energy In Minnesota, U.S. Deputy Secretary of Energy Poneman Highlights Clean Energy Industries That Are Driving American Manufacturing Growth In Minnesota, U.S. Deputy Secretary of Energy Poneman Highlights Clean Energy Industries That Are Driving American Manufacturing Growth July 16, 2012 - 4:37pm Addthis NEWS MEDIA CONTACT (202) 586-4940 PLYMOUTH, Minn. - U.S. Deputy Secretary of Energy Daniel Poneman today

  12. In Other News

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In Other News Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In Other News LANL employee chosen for "Frontiers of Engineering" Symposium; 16th Annual Hazmat Challenge strengthens response skills. September 1, 2012 dummy image Read our archives Contacts Editor Linda Anderman Email Community Programs Office Kurt Steinhaus Email LANL Employee Chosen for "Frontiers of

  13. In Other News

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In Other News Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In Other News Richard Marquez Leadership and Service Award established at NNMC; Lab employees recognized for Mars Rover contribution; Connections survey feedback results. November 1, 2012 dummy image Read our archives Contacts Editor Linda Anderman Email Community Programs Office Kurt Steinhaus Email Richard Marquez Leadership and

  14. In Other News

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In Other News Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In Other News Lecture on Sandia Lab history; LANL Foundation personnel changes. March 1, 2013 Rebbecca Ullrich is Sandia National Laboratories' historian Rebbecca Ullrich is Sandia National Laboratories' historian. Contacts Editor Linda Anderman Email Community Programs Office Kurt Steinhaus Email The Bradbury Science Museum's next

  15. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Connections has a new title, winners of the Robot Rodeo, local firm gets large grant and new kits available for regional teachers July 1, 2013 A new STEM teacher kit is being distributed throughout the region A new STEM teacher kit is being distributed throughout the region Contact Editor Linda Anderman Email Community

  16. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news New Mexico small businesses can submit leveraged proposals beginning August 20 August 1, 2013 Previous leveraged-project winner Nanotitanium Dental Implants (Walt Shuman, Dan Blacklock and Terry Lowe) Previous leveraged-project winner Nanotitanium Dental Implants (Walt Shuman, Dan Blacklock and Terry Lowe) Contact

  17. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Local nonprofits can apply for development grants, the Regional Development Corporation is recognized for its efforts and Northern New Mexico College receives grant September 1, 2013 The Regional Development Corporation was recently recognized for its economic development efforts The Regional Development Corporation was

  18. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Community Commitment Plan renewed, plus stories on giving, economic development and education November 1, 2013 The Regional Development Corporation was recently recognized for its economic development efforts New Mexico-based Ideum is just one of the organizations that has benefited from investments made through Los

  19. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Expanding Your Horizons, MathCounts winner goes to nationals, info on Lab trails and more April 1, 2014 Carlos Vigil Middle School students have fun at the Expanding Your Horizons conference. Carlos Vigil Middle School students have fun at the Expanding Your Horizons conference. Contact Community Programs Office Director

  20. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Regional Coalition, VAF recipient acquired by Google, Veteran-owned business June 1, 2014 Some of the Regional Coalition of LANL Communities members and alternates attending the coalition's April 25 meeting, (l to r) Tom Blankenhorn, Taos County Commissioner; Fran Berting, Los Alamos County Councilor; Danny Mayfield,

  1. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news New Smith's store donates to school supply drive; web tool for teacher collaboration; record amount pledged to employees' scholarship drive August 1, 2014 Los Alamos National Laboratory postdoctoral researcher Elena Guardincerri (r) and undergraduate research assistant Shelby Fellows (l) prepare a lead hemisphere inside a

  2. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news School drive results; New Mexico Middle School Electric Car Challenge; Española Valley Teen Biz Challenge September 1, 2014 A San Ildefonso Day School student selects from a mountain of backpacks collected during this year's backpack and school supply drive. A San Ildefonso Day School student selects from a mountain of

  3. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Employee Giving Campaign, Entrepreneurial Teen Grand Challenge, 2015 MidSchoolMath conference, new podcasts October 1, 2014 Winners of the 2014 Entrepreneurial Teen Grand Challenge; left to right Xena Martinez, Alejandro Atencio and Joshua Lopez. Winners of the 2014 Entrepreneurial Teen Grand Challenge; left to right Xena

  4. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Accelerate Technical Training; Earl Salazar reelected as tribal governor; Future City regional finals; winners of the Earth and Environmental Science Scholarship; Los Alamos County Science and Engineering Fair February 1, 2015 James H. Rodriguez Elementary School students Danny Serrano (second from left), José Olivas and

  5. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Laboratory dramatically reduces water use; Legislative measures recognize private STEM support; New grant will help expand Venture Acceleration Fund; Discover E; Embudo Valley Library; Santa Fe Radio Café replay April 1, 2015 State Representative Stephanie Garcia-Richard (far right) greets Kurt Steinhaus, Los Alamos

  6. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Safety, supercomputing, science museums, scholarships-read all about 'em. May 2, 2016 May is Motorcycle Safety Awareness Month Richard Sturgeon, head of the Lab's Motorcycle Safety Committee, wrote to the Governor suggesting that the state raise the safety awareness of New Mexican drivers and motorcyclists as the season

  7. In-Office Services:

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Office Services: Meet with an experienced attorney who can advise and represent you. Attorney Services include: * Reviewing and preparing documents * Making follow-up calls and writing letters * Providing legal advice and consultation * Representation in court Comprehensive Coverage protects you from costly legal fees. Most covered legal matters are 100% paid-in-full when you work with a Network Attorney. (See reverse side of flyer for details.) Reduced Fee Benefits are available for matters not

  8. Yttrium Dopants in Titania

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Your Records Management Responsibilities Your Records Management Responsibilities This pamphlet explains the objectives and requirements of DOE O 243.1 and the responsibilities of Federal and contractor employees If you are a government employee or contractor working for a federal agency, records management is part of your job. This pamphlet explains your responsibilities for federal records and provides the context for understanding records management in the federal government and in the

  9. lighting in the library

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Determine the Feasibility of Installing Energy Efficient Lighting In this part of the exercise, you will plan a new approach to lighting your school library. This new plan will use less energy, cost less, and result in less greenhouse gas. Your plan will also include bottom line calculations and decision factors such as: identifying the costs and payback for buying and installing new lighting equipment and making a determination about whether or not the new, more efficient lighting will provide

  10. THORIUM DISPERSION IN BISMUTH

    DOE Patents [OSTI]

    Bryner, J.S.

    1961-07-01

    The growth of thorium bismutaide particles, which are formed when thorium is suspended in liquid bismuth, is inhibited when the liquid metal suspension is being flowed through a reactor and through a heat exchanger in sequence. It involves the addition of as little as 1 part by weight of tellurium to 100 parts of thorium. This addition is sufficient to inhibit particle growth and agglomeration.

  11. Advances in Lithography

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Advances in Lithography Advances in Lithography Print Tuesday, 16 December 2014 11:40 Work featured on Applied Optics cover from ALS Beamline 11.3.2. Field-dependent wavefront aberration distribution of an extreme ultraviolet single-lens zone-plate microscope, recovered by the gradient descent algorithm customized for partially coherent imaging and targeted for fast and accurate retrieval. For information, see Yamazoe et al., pp. B34-B43, part of the Applied Optics-JOSA A cohosted feature,

  12. Lighting in the Library

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    lores

    hires

    The purpose of the Lighting in the Library Activity is to calculate the electricity used to provide lighting in the school library and determine the feasibility of saving energy and money by using energy efficient lighting fixtures. Your students will assume the role of an energy auditor assigned the task of assessing the current situation and making a recommendation for energy-efficient improvements. This activitity requires a trip to the library, an examination of the

  13. Singin' in the Rain

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Singin' in the Rain News News Home Featured Articles 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 Science Headlines Science Highlights Presentations & Testimony News Archives Communications and Public Affairs Contact Information Office of Science U.S. Department of Energy 1000 Independence Ave., SW Washington, DC 20585 P: (202) 586-5430 11.25.13 Singin' in the Rain Ultra water-repellent material developed at Brookhaven Lab may lead to many warming applications. Print Text

  14. Topics in nuclear power

    SciTech Connect (OSTI)

    Budnitz, Robert J.

    2015-03-30

    The 101 nuclear plants operating in the US today are far safer than they were 20-30 years ago. For example, there's been about a 100-fold reduction in the occurrence of 'significant events' since the late 1970s. Although the youngest of currently operating US plants was designed in the 1970s, all have been significantly modified over the years. Key contributors to the safety gains are a vigilant culture, much improved equipment reliability, greatly improved training of operators and maintenance workers, worldwide sharing of experience, and the effective use of probabilistic risk assessment. Several manufacturers have submitted high quality new designs for large reactors to the U.S. Nuclear Regulatory Commission (NRC) for design approval, and several companies are vigorously working on designs for smaller, modular reactors. Although the Fukushima reactor accident in March 2011 in Japan has been an almost unmitigated disaster for the local population due to their being displaced from their homes and workplaces and also due to the land contamination, its 'lessons learned' have been important for the broader nuclear industry, and will surely result in safer nuclear plants worldwide - indeed, have already done so, with more safety improvements to come.

  15. Environmental issues in China

    SciTech Connect (OSTI)

    Travis, P.S.

    1991-10-01

    Global concern about the environment is increasing, and the People's Republic of China (PRC) is not immune from such concerns. The Chinese face issues similar to those of many other developing nations. The US Department of Energy is particularly interested in national and world pollution issues, especially those that may infringe on other countries' economic growth and development. The DOE is also interested in any opportunities that might exist for US technical assistance and equipment in combating environmental problems. Our studies of articles in the China Daily, and English-language daily newspaper published by the Chinese government, show that population, pollution, and energy are major concerns of the Chinese Communist Party. Thus this report emphasizes the official Chinese government view. Supporting data were also obtained from other sources. Regardless of the severity of their various environmental problems, the Chinese will only try to remedy those problems with the greatest negative effects on its developing economy. They will be looking for foreign assistance, financial and informational, to help implement solutions. With the Chinese government seeking assistance, the United States has an opportunity to export basic technical information, especially in the areas of pollution control and monitoring, oil exploration methods, oil drilling technology, water and sewage treatment procedures, hazardous waste and nuclear waste handling techniques, and nuclear power plant safety procedures. In those areas the US has expertise and extensive technical experience, and by exporting the technologies the US would benefit both economically and politically. 59 refs., 3 figs.

  16. LBB in Candu plants

    SciTech Connect (OSTI)

    Kozluk, M.J.; Vijay, D.K.

    1997-04-01

    Postulated catastrophic rupture of high-energy piping systems is the fundamental criterion used for the safety design basis of both light and heavy water nuclear generating stations. Historically, the criterion has been applied by assuming a nonmechanistic instantaneous double-ended guillotine rupture of the largest diameter pipes inside of containment. Nonmechanistic, meaning that the assumption of an instantaneous guillotine rupture has not been based on stresses in the pipe, failure mechanisms, toughness of the piping material, nor the dynamics of the ruptured pipe ends as they separate. This postulated instantaneous double-ended guillotine rupture of a pipe was a convenient simplifying assumption that resulted in a conservative accident scenario. This conservative accident scenario has now become entrenched as the design basis accident for: containment design, shutdown system design, emergency fuel cooling systems design, and to establish environmental qualification temperature and pressure conditions. The requirement to address dynamic effects associated with the postulated pipe rupture subsequently evolved. The dynamic effects include: potential missiles, pipe whipping, blowdown jets, and thermal-hydraulic transients. Recent advances in fracture mechanics research have demonstrated that certain pipes under specific conditions cannot crack in ways that result in an instantaneous guillotine rupture. Canadian utilities are now using mechanistic fracture mechanics and leak-before-break assessments on a case-by-case basis, in limited applications, to support licensing cases which seek exemption from the need to consider the various dynamic effects associated with postulated instantaneous catastrophic rupture of high-energy piping systems inside and outside of containment.

  17. Synchrotron polarization in blazars

    SciTech Connect (OSTI)

    Zhang, Haocheng; Bttcher, Markus; Chen, Xuhui

    2014-07-01

    We present a detailed analysis of time- and energy-dependent synchrotron polarization signatures in a shock-in-jet model for ?-ray blazars. Our calculations employ a full three-dimensional radiation transfer code, assuming a helical magnetic field throughout the jet. The code considers synchrotron emission from an ordered magnetic field, and takes into account all light-travel-time and other relevant geometric effects, while the relevant synchrotron self-Compton and external Compton effects are handled with the two-dimensional Monte-Carlo/Fokker-Planck (MCFP) code. We consider several possible mechanisms through which a relativistic shock propagating through the jet may affect the jet plasma to produce a synchrotron and high-energy flare. Most plausibly, the shock is expected to lead to a compression of the magnetic field, increasing the toroidal field component and thereby changing the direction of the magnetic field in the region affected by the shock. We find that such a scenario leads to correlated synchrotron + synchrotron-self-Compton flaring, associated with substantial variability in the synchrotron polarization percentage and position angle. Most importantly, this scenario naturally explains large polarization angle rotations by ? 180, as observed in connection with ?-ray flares in several blazars, without the need for bent or helical jet trajectories or other nonaxisymmetric jet features.

  18. Recent Developments in SHERPA

    SciTech Connect (OSTI)

    Archibald, Jennifer; Gleisberg, Tanju; Hoeche, Stefan; Krauss, Frank; Schonherr, Marek; Schumann, Steffen; Siegert, Frank; Winter, Jan; /Fermilab

    2011-11-15

    Some recent QCD-related developments in the SHERPA event generator are presented. In the past decades, event generators such as PYTHIA [1, 2] and HERWIG [3, 4] have been central for nearly all physics analyses at particle physics experiments at the high-energy frontier. This will also hold true at the LHC, where a large number of interesting signals for new particles or new phenomena (the Higgs boson or any other manifestation of the mechanism behind electro-weak symmetry breaking, supersymmetry, extra dimensions etc.) is hampered by a plethora of severe, sometimes overwhelming backgrounds. Nearly all of them are largely influenced by QCD. Therefore it seems fair to say that the success of the LHC in finding new physics may very well depend on a deep and detailed understanding of old physics, like QCD. Examples for this include, among others, the central-jet veto for the vector boson fusion channel for Higgs production or topologies, where gauge bosons emerge in association with many jets, a background for many search channels. In a reflection on increased needs by the experimental community, aiming at higher precision, incorporation of new physics models and so on, the work horses of old have undergone serious renovation efforts, resulting in new, improved versions of the respective codes, namely PYTHIA8 [5] and HERWIG++ [6]. In addition a completely new code, SHERPA [7], has been constructed and is in the process of maturing. The status of this code is the topic of this contribution. SHERPA's hallmark property is the inclusion of higher-order tree-level QCD contributions, leading to an improved modelling of jet production. They are introduced through a full-fledged matrix element generator, AMEGIC++ [8], which is capable of generating matrix elements and corresponding phase space mappings for processes with multi-particle final states in various models, including the Standard Model, anomalous gauge triple and quadruple couplings according to [9, 10], the Minimal Supersymmetric Standard Model with Feynman rules from [11], the ADD-model of extra dimensions [12, 13], and a model with an extra U(1) singlet coupling to the Higgs boson only [14]. The code has been thoroughly tested and validated [15]. This code, however, is limited, especially in the treatment of many ({ge} 6) external QCD particles. Therefore, in the near future, SHERPA will incorporate another, new matrix element generator, COMIX, which is based on Berends-Giele recursion relations [16] and color-dressing [17] rather than color-ordering. In Tabs. 1 and 2 some example cross sections for gg {yields} ng at fixed energies and pp {yields} b{bar b} + n jets obtained with this program are exhibited and compared to those from other programs. In addition, concerning the calculation of higher-order matrix elements and cross sections, there have been first steps towards an automation of such calculations at truly next-to leading order accuracy. They manifest themselves in the implementation of a procedure [19] to fully automatically construct and evaluate Catani-Seymour dipole subtraction terms [20] for the real part of such NLO calculations. The results from the matrix element calculations are merged with the subsequent parton shower through the formalism of [21, 22]. The results of its implementation in SHERPA [23] has recently been compared with other algorithms [24]. Although there remains some dispute about the theoretical equivalence of the different approaches, the overall results show satisfying agreement with each other, such that they can be used with confidence for data analysis.

  19. Clean Energy Investment in Developing Countries: Wind Power in...

    Open Energy Info (EERE)

    Countries: Wind Power in Egypt Jump to: navigation, search Name Clean Energy Investment in Developing Countries: Wind Power in Egypt AgencyCompany Organization...

  20. Fuel Flexibility in Gasification

    SciTech Connect (OSTI)

    McLendon, T. Robert; Pineault, Richard L.; Richardson, Steven W.; Rockey, John M.; Beer, Stephen K.; Lui, Alain P.; Batton, William A.

    2001-11-06

    In order to increase efficiencies of carbonizers, operation at high pressures is needed. In addition, waste biomass fuels of opportunity can be used to offset fossil fuel use. The National Energy Technology Laboratory (NETL) Fluidized Bed Gasifier/Combustor (FBG/C) was used to gasify coal and mixtures of coal and biomass (sawdust) at 425 psig. The purpose of the testing program was to generate steady state operating data for modeling efforts of carbonizers. A test program was completed with a matrix of parameters varied one at a time in order to avoid second order interactions. Variables were: coal feed rate, pressure, and varying mixtures of sawdust and coal types. Coal types were Montana Rosebud subbituminous and Pittsburgh No. 8 bituminous. The sawdust was sanding waste from a furniture manufacturer in upstate New York. Coal was sieved from -14 to +60 mesh and sawdust was sieved to -14 mesh. The FBG/C operates at a nominal 425 psig, but pressures can be lowered. For the tests reported it was operated as a jetting, fluidized bed, ash-agglomerating gasifier. Preheated air and steam are injected into the center of the bottom along with the solid feed that is conveyed with cool air. Fairly stable reactor internal flow patterns develop and temperatures stabilize (with some fluctuations) when steady state is reached. At nominal conditions the solids residence time in the reactor is on the order of 1.5 to 2 hours, so changes in feed types can require on the order of hours to equilibrate. Changes in operating conditions (e.g. feed rate) usually require much less time. The operating periods of interest for these tests were only the steady state periods, so transient conditions were not monitored as closely. The test matrix first established a base case of operations to which single parameter changes in conditions could be compared. The base case used Montana Rosebud at a coal feed rate of 70 lbm/hr at 425 psig. The coal sawdust mixtures are reported as percent by weight coal to percent by weight sawdust. The mixtures of interest were: 65/35 subbituminous, 75/25 subbituminous, 85/15 subbituminous, and 75/25 bituminous. Steady state was achieved quickly when going from one subbituminous mixture to another, but longer when going from subbituminous to bituminous coal. The most apparent observation when comparing the base case to subbituminous coal/sawdust mixtures is that operating conditions are nearly the same. Product gas does not change much in composition and temperatures remain nearly the same. Comparisons of identical weight ratios of sawdust and subbituminous and bituminous mixtures show considerable changes in operating conditions and gas composition. The highly caking bituminous coal used in this test swelled up and became about half as dense as the comparable subbituminous coal char. Some adjustments were required in accommodating changes in solids removal during the test. Nearly all the solids in the bituminous coal sawdust were conveyed into the upper freeboard section and removed at the mid-level of the reactor. This is in marked contrast to the ash-agglomerating condition where most solids are removed at the very bottom of the gasifier. Temperatures in the bottom of the reactor during the bituminous test were very high and difficult to control. The most significant discovery of the tests was that the addition of sawdust allowed gasification of a coal type that had previously resulted in nearly instant clinkering of the gasifier. Several previous attempts at using Pittsburgh No. 8 were done only at the end of the tests when shutdown was imminent anyway. It is speculated that the fine wood dust somehow coats the pyrolyzed sticky bituminous coal particles and prevents them from agglomerating quickly. As the bituminous coal char particles swell, they are carried to the cooler upper regions of the reactor where they re-solidify. Other interesting phenomena were revealed regarding the transport (rheological) properties of the coal sawdust mixtures. The coal sawdust mixtures segregate quickly when transported. This is visibly apparent. To prevent bridges and ratholes from developing in the lowest coal feed hopper, it is normally fluidized. When feeding the coal sawdust mixtures the fluidizing gas was turned off to prevent segregation. The feed system worked as well with no fluidizing gas when using the mixtures as it did with fluidizing gas and only coal. In addition, it was inadvertently discovered that greatly increased pressure above the feeder resulted in greatly increased flow with the mixtures. Increased pressure above the feeder with coal only results in quickly plugging the feed system. Also, it was learned that addition of sawdust reduces the system loss during conveying compared to coal only. This is in spite of overall smaller particle sizes with the coal sawdust mixtures.

  1. MEMS in microfluidic channels.

    SciTech Connect (OSTI)

    Ashby, Carol Iris Hill; Okandan, Murat; Michalske, Terry A.; Sounart, Thomas L.; Matzke, Carolyn M.

    2004-03-01

    Microelectromechanical systems (MEMS) comprise a new class of devices that include various forms of sensors and actuators. Recent studies have shown that microscale cantilever structures are able to detect a wide range of chemicals, biomolecules or even single bacterial cells. In this approach, cantilever deflection replaces optical fluorescence detection thereby eliminating complex chemical tagging steps that are difficult to achieve with chip-based architectures. A key challenge to utilizing this new detection scheme is the incorporation of functionalized MEMS structures within complex microfluidic channel architectures. The ability to accomplish this integration is currently limited by the processing approaches used to seal lids on pre-etched microfluidic channels. This report describes Sandia's first construction of MEMS instrumented microfluidic chips, which were fabricated by combining our leading capabilities in MEMS processing with our low-temperature photolithographic method for fabricating microfluidic channels. We have explored in-situ cantilevers and other similar passive MEMS devices as a new approach to directly sense fluid transport, and have successfully monitored local flow rates and viscosities within microfluidic channels. Actuated MEMS structures have also been incorporated into microfluidic channels, and the electrical requirements for actuation in liquids have been quantified with an elegant theory. Electrostatic actuation in water has been accomplished, and a novel technique for monitoring local electrical conductivities has been invented.

  2. Crown ethers in graphene

    SciTech Connect (OSTI)

    Guo, Junjie; Lee, Jaekwang; Contescu, Cristian I; Gallego, Nidia C; Pantelides, Sokrates T.; Pennycook, Stephen J; Moyer, Bruce A; Chisholm, Matthew F

    2014-01-01

    Crown ethers, introduced by Pedersen1, are at their most basic level neutral rings constructed of oxygen atoms linked by two- or three-carbon chains. They have attracted special attention for their ability to selectively incorporate various atoms2 or molecules within the cavity formed by the ring3-6. This property has led to the use of crown ethers and their compounds in a wide range of chemical and biological applications7,8. However, crown ethers are typically highly flexible, frustrating efforts to rigidify them for many uses that demand higher binding affinity and selectivity9,10. In this Letter, we report atomic-resolution images of the same basic structures of the original crown ethers embedded in graphene. This arrangement constrains the crown ethers to be rigid and planar and thus uniquely suited for the many applications that crown ethers are known for. First-principles calculations show that the close similarity of the structures seen in graphene with those of crown ether molecules also extends to their selectivity towards specific metal cations depending on the ring size. Atoms (or molecules) incorporated within the crown ethers in graphene offer a simple environment that can be easily and systematically probed and modeled. Thus, we expect that this discovery will introduce a new wave of investigations and applications of chemically functionalized graphene.

  3. Crown ethers in graphene

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Guo, Junjie; Lee, Jaekwang; Contescu, Cristian I; Gallego, Nidia C; Pantelides, Sokrates T.; Pennycook, Stephen J; Moyer, Bruce A; Chisholm, Matthew F

    2014-01-01

    Crown ethers, introduced by Pedersen1, are at their most basic level neutral rings constructed of oxygen atoms linked by two- or three-carbon chains. They have attracted special attention for their ability to selectively incorporate various atoms2 or molecules within the cavity formed by the ring3-6. This property has led to the use of crown ethers and their compounds in a wide range of chemical and biological applications7,8. However, crown ethers are typically highly flexible, frustrating efforts to rigidify them for many uses that demand higher binding affinity and selectivity9,10. In this Letter, we report atomic-resolution images of the same basicmore » structures of the original crown ethers embedded in graphene. This arrangement constrains the crown ethers to be rigid and planar and thus uniquely suited for the many applications that crown ethers are known for. First-principles calculations show that the close similarity of the structures seen in graphene with those of crown ether molecules also extends to their selectivity towards specific metal cations depending on the ring size. Atoms (or molecules) incorporated within the crown ethers in graphene offer a simple environment that can be easily and systematically probed and modeled. Thus, we expect that this discovery will introduce a new wave of investigations and applications of chemically functionalized graphene.« less

  4. Confidence in Numerical Simulations

    SciTech Connect (OSTI)

    Hemez, Francois M.

    2015-02-23

    This PowerPoint presentation offers a high-level discussion of uncertainty, confidence and credibility in scientific Modeling and Simulation (M&S). It begins by briefly evoking M&S trends in computational physics and engineering. The first thrust of the discussion is to emphasize that the role of M&S in decision-making is either to support reasoning by similarity or to “forecast,” that is, make predictions about the future or extrapolate to settings or environments that cannot be tested experimentally. The second thrust is to explain that M&S-aided decision-making is an exercise in uncertainty management. The three broad classes of uncertainty in computational physics and engineering are variability and randomness, numerical uncertainty and model-form uncertainty. The last part of the discussion addresses how scientists “think.” This thought process parallels the scientific method where by a hypothesis is formulated, often accompanied by simplifying assumptions, then, physical experiments and numerical simulations are performed to confirm or reject the hypothesis. “Confidence” derives, not just from the levels of training and experience of analysts, but also from the rigor with which these assessments are performed, documented and peer-reviewed.

  5. New Studies Aid in Optimizing Water Use in Geothermal Applications...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Studies Aid in Optimizing Water Use in Geothermal Applications New Studies Aid in Optimizing Water Use in Geothermal Applications July 31, 2014 - 4:31pm Addthis The Energy ...

  6. Substantial improvements in methyl ketone production in E. coli and

    Office of Scientific and Technical Information (OSTI)

    insights on the pathway from in vitro studies (Journal Article) | SciTech Connect Journal Article: Substantial improvements in methyl ketone production in E. coli and insights on the pathway from in vitro studies Citation Details In-Document Search Title: Substantial improvements in methyl ketone production in E. coli and insights on the pathway from in vitro studies Authors: Goh, Ee-Been ; Baidoo, Edward E.K. ; Burd, Helcio ; Lee, Taek Soon ; Keasling, Jay D. ; Beller, Harry R. Publication

  7. Spin caloritronics in graphene

    SciTech Connect (OSTI)

    Ghosh, Angsula; Frota, H. O.

    2015-06-14

    Spin caloritronics, the combination of spintronics with thermoelectrics, exploiting both the intrinsic spin of the electron and its associated magnetic moment in addition to its fundamental electronic charge and temperature, is an emerging technology mainly in the development of low-power-consumption technology. In this work, we study the thermoelectric properties of a Rashba dot attached to two single layer/bilayer graphene sheets as leads. The temperature difference on the two graphene leads induces a spin current, which depends on the temperature and chemical potential. We demonstrate that the Rashba dot behaves as a spin filter for selected values of the chemical potential and is able to filter electrons by their spin orientation. The spin thermopower has also been studied where the effects of the chemical potential, temperature, and also the Rashba term have been observed.

  8. Progress in Initiator Modeling

    SciTech Connect (OSTI)

    Hrousis, C A; Christensen, J S

    2009-05-04

    There is great interest in applying magnetohydrodynamic (MHD) simulation techniques to the designs of electrical high explosive (HE) initiators, for the purpose of better understanding a design's sensitivities, optimizing its performance, and/or predicting its useful lifetime. Two MHD-capable LLNL codes, CALE and ALE3D, are being used to simulate the process of ohmic heating, vaporization, and plasma formation in the bridge of an initiator, be it an exploding bridgewire (EBW), exploding bridgefoil (EBF) or slapper type initiator. The initiation of the HE is simulated using Tarver Ignition & Growth reactive flow models. 1-D, 2-D and 3-D models have been constructed and studied. The models provide some intuitive explanation of the initiation process and are useful for evaluating the potential impact of identified aging mechanisms (such as the growth of intermetallic compounds or powder sintering). The end product of this work is a simulation capability for evaluating margin in proposed, modified or aged initiation system designs.

  9. Cooper Pairs in Insulators?!

    ScienceCinema (OSTI)

    James Valles

    2010-01-08

    Nearly 50 years elapsed between the discovery of superconductivity and the emergence of the microscopic theory describing this zero resistance state. The explanation required a novel phase of matter in which conduction electrons joined in weakly bound pairs and condensed with other pairs into a single quantum state. Surprisingly, this Cooper pair formation has also been invoked to account for recently uncovered high-resistance or insulating phases of matter. To address this possibility, we have used nanotechnology to create an insulating system that we can probe directly for Cooper pairs. I will present the evidence that Cooper pairs exist and dominate the electrical transport in these insulators and I will discuss how these findings provide new insight into superconductor to insulator quantum phase transitions. 

  10. Alloys in energy development

    SciTech Connect (OSTI)

    Frost, B.R.T.

    1984-02-01

    The development of new and advanced energy systems often requires the tailoring of new alloys or alloy combinations to meet the novel and often stringent requirements of those systems. Longer life at higher temperatures and stresses in aggressive environments is the most common goal. Alloy theory helps in achieving this goal by suggesting uses of multiphase systems and intermediate phases, where solid solutions were traditionally used. However, the use of materials under non-equilibrium conditions is now quite common - as with rapidly solidified metals - and the application of alloy theory must be modified accordingly. Under certain conditions, as in a reactor core, the rate of approach to equilibrium will be modified; sometimes a quasi-equilibrium is established. Thus an alloy may exhibit enhanced general diffusion at the same time as precipitate particles are being dispersed and solute atoms are being carried to vacancy sinks. We are approaching an understanding of these processes and can begin to model these complex systems.

  11. Similitude in thermoacoustics

    SciTech Connect (OSTI)

    Olson, J.R.; Swift, G.W. )

    1994-03-01

    Similitude is applied to thermoacoustics without using the acoustic approximation. The equations which are important to thermoacoustics (continuity, motion, and heat transfer) are rewritten in dimensionless form, verifying that the list of dimensionless variables obtained from similitude is complete. Similitude is demonstrated in the thermoacoustic engine using helium, neon, and argon as working fluids, even for large-pressure-amplitude nonlinear behavior which differs significantly from predictions of linear thermoacoustic theory. Measurements are also presented for nitrogen and a helium-argon mixture, in order to reveal the influence of the specific-heat ratio and Prandtl number. Implications of similitude for building scale models are discussed; dimensions, temperatures, or pressures can be scaled. 9 refs., 6 figs., 1 tab.

  12. NERSC in the News

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    NERSC in the News NERSC in the News Sort by: Default | Name | Date (low-high) | Date (high-low) | Source Creating the First 100 Gbps Research Link across the Atlantic May 1, 2013 | Source: Scientific Computing | NERSC Managers Shed Light on 'Edison' April 29, 2013 | Source: HPCWire | Named Edison, NERSC's new machine is a Cray XC30 with 664 compute nodes and 10,624 cores. Each node has two eight-core Intel "Sandy Bridge" processors running at 2.6 GHz (16 cores per node), and has 64 GB

  13. In other news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In other news Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:May 2016 all issues All Issues » submit In other news Holiday Gift Drive; Electric Car Challenge success; national Wreaths Across America December 1, 2014 The holiday season is a good time to make a difference. The holiday season is a good time to make a difference. Contact Community Programs Director Kurt Steinhaus Email Editor Ute Haker Email Please click on the title(s)

  14. Garbage in, garbage out

    SciTech Connect (OSTI)

    Mann, C.

    1987-01-01

    Many US cities are using incinerators to replace landfills for municipal waste disposal. The plants burn municipal waste as fuel to generate steam and electricity, while reducing the volume of trash by 60-90%. But, along with electricity the plants are generating concern among environmentalists, who say the ash the plants produce and the emissions from their stacks are serious health hazards. In EPA tests every sample of fly ash showed unacceptable levels of toxic metals such as lead and cadmium. Concentrations of dioxin and furan are also present in fly ash.

  15. Tall order in Arizona

    SciTech Connect (OSTI)

    Wright, A.G.

    1997-03-10

    A 7-year, $470 million project to retrofit scrubber units on a coal-fired power plant is summarized. The scrubbers will be retooled at the 2250-MW Navajo Generating Station in a clean air agreement between the US federal government and Salt River Project. A forced oxidation flue gas desulfurization system was selected for the retrofit; design and construction aspects are summarized in the article. Negotiations between the US Environmental Protection Agency, the Environmental Defense Fund, and the Navajo Nation leading to the retrofit action are also outlined.

  16. Equilibria in Chemical Systems

    Energy Science and Technology Software Center (OSTI)

    1992-01-01

    SOLGASMIX-PV calculates equilibrium relationships in complex chemical systems. Chemical equilibrium calculations involve finding the system composition, within certain constraints, which contains the minimum free energy. The constraints are the preservation of the masses of each element present and either constant pressure or volume. SOLGASMIX-PV can calculate equilibria in systems containing a gaseous phase, condensed phase solutions, and condensed phases of invariant and variable stoichiometry. Either a constant total gas volume or a constant total pressuremore » can be assumed. Unit activities for condensed phases and ideality for solutions are assumed, although nonideal systems can be handled provided activity coefficient relationships are available.« less

  17. Kink modes in pedestal

    SciTech Connect (OSTI)

    Wang, Z. T.; College of Physics Science and Technology, Sichuan University, Chengdu 610065 ; He, Z. X.; Dong, J. Q.; Wang, Z. H.; Xu, M.; Xu, X. L.; Mou, M. L.; Sun, T. T.; Huang, J.; Chen, S. Y.; Tang, C. J.

    2014-03-15

    Kink modes are investigated in pedestal for shaped tokamaks. An analytic combining criterion is presented. It lies on the middle of the sufficient criterion of Lortz and necessary criterion of Mercier giving a more restricted necessary criterion. Growth rates and mode structure are calculated. For large poloidal mode number, the modes are highly localized in both poloidal and radial directions. The modes increase rapidly when they approach to the resonant surface. They are typical of edge localized modes (ELMs). It is assumed that the modes vanish inside the next resonant surface, then, there seems to be a second stable region. Several mitigation methods for controlling ELMs are proposed.

  18. Made in Germany

    SciTech Connect (OSTI)

    2005-09-01

    This supplement was prepared in collaboration with the Association of German Mining Machine Manufacturers within VDMA to give an overview of German manufacturers' contribution to the coal industry. It has 18 short papers and a VDMA vendor matrix and directory. Papers include details of MAN Takraf's surface mining equipment, hydraulic shovels and excavators from Komatsu, Liebherr and Terex O & K, Siemens motors and electric control technology in trucks, shovels etc., new technology from DBT, IBS and Wirth, and low emission engines and drives from Deutz and DaimlerCrysler. 2 figs.

  19. Scientist in the Spotlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientist in the Spotlight Scientist in the Spotlight WHEN: Jan 09, 2016 11:00 AM - 1:00 PM WHERE: Bradbury Science Museum 1350 Central Ave, Los Alamos, NM 87544, USA CONTACT: Linda Anderman (505) 665-9196 CATEGORY: Bradbury INTERNAL: Calendar Login Event Description MARK YOUR CALENDARS for this special event! Every second Saturday from 11 a.m. to 1 p.m., the Museum features actual scientists and researchers talking to visitors about their favorite Science, Technology, Engineering and Math

  20. Scientist in the Spotlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientist in the Spotlight Scientist in the Spotlight WHEN: Mar 12, 2016 11:00 AM - 1:00 PM WHERE: Bradbury Science Museum 1350 Central Ave, Los Alamos, NM 87544, USA CONTACT: Linda Anderman (505) 665-9196 CATEGORY: Bradbury INTERNAL: Calendar Login Event Description MARK YOUR CALENDARS for this special event. Every second Saturday from 11 a.m. to 1 p.m., the Museum has scientists available to talk to visitors about their exciting topics. Fun for the whole family! Capturing an eggs-plosion on

  1. Scientists in the Spotlight

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientists in the Spotlight Scientists in the Spotlight WHEN: Feb 14, 2015 11:00 AM - 1:00 PM WHERE: Bradbury Science Museum, 1350 Central Ave, Los Alamos, USA CONTACT: Jessica Privette 505 667-0375 CATEGORY: Bradbury INTERNAL: Calendar Login Scientist Spotlight Event Description MARK YOUR CALENDARS for this special event! Every second Saturday from 11:00 AM to 1:00 PM, the museum will have special scientists on the floor talking to people about their favorite STEM topics. The scientists

  2. Also In This Issue

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In This Issue ■ Annual review assesses the state of science and technology in NMT Division ■ Technology transfer between Savannah River and the national labs ■ Plutonium Futures conference speakers set ■ Mary Neu is intrigued by actinides ■ "Eye of the Beholder" N u c l e a r M a t e r i a l s R e s e a r c h a n d T e c h n o l o g y Quarterly Actinide Research Researchers cast first "spiked" plutonium alloy 2nd quarter 2002 Nuclear Materials Technology Division

  3. Biogas systems in India

    SciTech Connect (OSTI)

    Lichtman, R.J.

    1983-01-01

    In addition to an analysis of household energy consumption, three scenarios are presented for the economic analysis of energy systems used for cooking, lighting, irrigation, and rice husk-cement manufacture. Digester design and feedstock variations are discussed. Problems such as gas pricing, sociological problems of distribution to diverse ethnic groups, and the complexity of technology transfer are mentioned. (CKK)

  4. Mercury in the environment

    ScienceCinema (OSTI)

    Idaho National Laboratory - Mike Abbott

    2010-01-08

    Abbott works for Idaho National Laboratory as an environmental scientist. Using state-of-thescienceequipment, he continuously samples the air, looking for mercury. In turn, he'll analyzethis long-term data and try to figure out the mercury's point of or

  5. Composting in tandem

    SciTech Connect (OSTI)

    Sheehan, K.

    1994-03-01

    A composting company, a county, and a waste company have formed a symbiotic public/private relationship that is helping to extend the life of the area's landfills, as well as produce a needed product. California state assembly bill 939, passed in 1989, directed local governments to reduce the amount of garbage being landfilled in order to curtail the need for new landfills. Cities and counties in California are now mandated to reduce the volume of their waste stream by 25% by 1995. By the year 2000, the waste stream must be reduced by 50%. And the law has teeth -- to ensure these percentages are met, a $10,000 fine can be imposed for each day a deadline is missed. According to 1990 figures, Sonoma County's well-established recycling programs have been successful at diverting 15% of the county's waste stream from the landfill. Paula Magyari, a waste management specialist with the county Public Works Department, says yard wastes account for 13% of the waste stream in Sonoma County; wood wastes for at least 15%. At 13% and 15%, they are two of the largest components of the waste stream, and, equally important, they represent the portion of the waste stream that is most readily reusable to meet the 25% goal.

  6. Radioactivity in food crops

    SciTech Connect (OSTI)

    Drury, J.S.; Baldauf, M.F.; Daniel, E.W.; Fore, C.S.; Uziel, M.S.

    1983-05-01

    Published levels of radioactivity in food crops from 21 countries and 4 island chains of Oceania are listed. The tabulation includes more than 3000 examples of 100 different crops. Data are arranged alphabetically by food crop and geographical origin. The sampling date, nuclide measured, mean radioactivity, range of radioactivities, sample basis, number of samples analyzed, and bibliographic citation are given for each entry, when available. Analyses were reported most frequently for /sup 137/Cs, /sup 40/K, /sup 90/Sr, /sup 226/Ra, /sup 228/Ra, plutonium, uranium, total alpha, and total beta, but a few authors also reported data for /sup 241/Am, /sup 7/Be, /sup 60/Co, /sup 55/Fe, /sup 3/H, /sup 131/I, /sup 54/Mn, /sup 95/Nb, /sup 210/Pb, /sup 210/Po, /sup 106/Ru, /sup 125/Sb, /sup 228/Th, /sup 232/Th, and /sup 95/Zr. Based on the reported data it appears that radioactivity from alpha emitters in food crops is usually low, on the order of 0.1 Bq.g/sup -1/ (wet weight) or less. Reported values of beta radiation in a given crop generally appear to be several orders of magnitude greater than those of alpha emitters. The most striking aspect of the data is the great range of radioactivity reported for a given nuclide in similar food crops with different geographical origins.

  7. Extreme Energy in China

    SciTech Connect (OSTI)

    Khanna, Nina; Fridley, David; Cai, Lixue

    2013-06-01

    Over the last decade, China has focused its policies simultaneously on moderating the rapid energy demand growth that has been driven by three decades of rapid economic growth and industrialization and on increasing its energy supply. In spite of these concerted efforts, however, China continues to face growing energy supply challenges, particularly with accelerating demand for oil and natural gas, both of which are now heavily dependent on imports. On the supply side, the recent 11th and 12th Five-Year Plans have emphasized accelerating conventional and nonconventional oil and gas exploration and development through pricing reforms, pipeline infrastructure expansions and 2015 production targets for shale gas and coal seam methane. This study will analyze China’s new and nonconventional oil and gas resources base, possible development paths and outlook, and the potential role for these nonconventional resources in meeting oil and gas demand. The nonconventional resources currently being considered by China and included in this study include: shale gas, coal seam methane (coal mine methane and coal bed methane), tight gas, in-situ coal gasification, tight oil and oil shale, and gas hydrates.

  8. Modulating lignin in plants

    DOE Patents [OSTI]

    Apuya, Nestor; Bobzin, Steven Craig; Okamuro, Jack; Zhang, Ke

    2013-01-29

    Materials and methods for modulating (e.g., increasing or decreasing) lignin content in plants are disclosed. For example, nucleic acids encoding lignin-modulating polypeptides are disclosed as well as methods for using such nucleic acids to generate transgenic plants having a modulated lignin content.

  9. Advances in geotectural design

    SciTech Connect (OSTI)

    Boyer, L.L. (ed.)

    1986-01-01

    Although the price of oil dropped well below $20 US earlier this year from a previous high above $35 US, the interest and participation shown in this conference does not seem to have been materially affected. Perhaps energy, although not unimportant, is no longer the driving force behind the continuing development and exploration of the earth shelter idiom in architecture. Rather, the thrust of most papers seems to seek an understanding of the adaptation of earth shelter into varied types of settings, especially urban applications, and also the understanding of the physical phenomenon of how an earth shelter works. The paper have been grouped into three basic categories with several subsections in each category. First, vernacular approaches are documented from the viewpoint of habitation, and followed by other types of utilization. Then, recent theoretical developments are reviewed in terms of materials, occupant studies, and heat transfer and air flow analyses. The final section deals with contemporary practice, where design concepts and case studies are presented, followed by building systems and urban planning aspects. All 54 papers have been abstracted separately for inclusion on the Energy Data Base.

  10. LPG in Argentina

    SciTech Connect (OSTI)

    Calcagno, O.

    1986-01-01

    The GNP for Argentina in 1985 was of about 70 billion dollars ( a little over 2200 dollars/capita), the same as 1970 in real terms; foreign debt being over 40 billion. After several years of negative GNP growth, it will probably show a moderate increase in 1986. Industry represents 21 percent of the GNP, agriculture 16 percent. Total exports 12-14 percent. Imports are 8-9 percent. Historical investment of the energy sector was about 3.4 percent. The State, the Public Sector, plays an important role in every aspect, concentrating about 50 percent of the economy. For example, the Central Government sets official prices for most of the forms of energy. Normally, these prices do not relate to international price levels. The country has to catch up with the developed world and it is striving to increase productivity. There is a need to get its products to the external market as well as to attract foreign investment. The government has apparently become fully aware of that, being now a matter of how those goals are accomplished. It may take some time and reeducation of people at all levels to do so.

  11. Awardee Share in STRIPES

    Broader source: Energy.gov [DOE]

    A problem has been identified with completing the awardee share fields on the FAADS/FAADS Plus reporting screen in STRIPES. Data quality is an area of major focus especially for the data being sent to USASpending.gov as required by the Federal Funding and Transparency Act.

  12. Butanol tolerance in microorganisms

    DOE Patents [OSTI]

    Bramucci, Michael G.; Nagarajan, Vasantha

    2016-03-01

    Provided herein are recombinant yeast host cells and methods for their use for production of fermentation products from a pyruvate utilizing pathway. Yeast host cells provided herein comprise reduced pyruvate decarboxylase activity and modified adenylate cyclase activity. In embodiments, yeast host cells provided herein comprise resistance to butanol and increased biomass production.

  13. LHS 2803B: A VERY WIDE MID-T DWARF COMPANION TO AN OLD M DWARF IDENTIFIED FROM PAN-STARRS1

    SciTech Connect (OSTI)

    Deacon, Niall R.; Liu, Michael C.; Magnier, Eugene A.; Bowler, Brendan P.; Mann, Andrew W.; Burgett, William S.; Chambers, Ken C.; Kaiser, Nick; Kudritzki, Rolf-Peter; Morgan, Jeff S.; Tonry, John L.; Wainscoat, Richard J.; Redstone, Joshua A.; Hodapp, Klaus W.; Price, Paul A.

    2012-09-20

    We report the discovery of a wide ({approx}1400 AU projected separation), common proper motion companion to the nearby M dwarf LHS 2803 (PSO J207.0300-13.7422). This object was discovered during our census of the local T dwarf population using Pan-STARRS1 and Two Micron All Sky Survey data. Using the Infrared Telescope Facility/SpeX near-infrared spectroscopy, we classify the secondary to be spectral type T5.5. University of Hawaii 2.2 m/SuperNova Integral Field Spectrograph optical spectroscopy indicates that the primary has a spectral type of M4.5, with approximately solar metallicity and no measurable H{alpha} emission. We use this lack of activity to set a lower age limit for the system of 3.5 Gyr. Using a comparison with chance alignments of brown dwarfs and nearby stars, we conclude that the two objects are unlikely to be a chance association. The primary's photometric distance of 21 pc and its proper motion implies thin disk kinematics. Based on these kinematics and its metallicity, we set an upper age limit for the system of 10 Gyr. Evolutionary model calculations suggest that the secondary has a mass of 72{+-}{sup 4}{sub 7} M{sub Jup}, temperature of 1120 {+-} 80 K, and log g = 5.4 {+-} 0.1 dex. Model atmosphere fitting to the near-IR spectrum gives similar physical parameters of 1100 K and log g = 5.0.

  14. Research in Neutrino Physics

    SciTech Connect (OSTI)

    Busenitz, Jerome

    2014-09-30

    Research in Neutrino Physics We describe here the recent activities of our two groups over the first year of this award (effectively November 2010 through January 2012) and our proposed activities and associated budgets for the coming grant year. Both of our groups are collaborating on the Double Chooz reactor neutrino experiment and are playing major roles in calibration and analysis. A major milestone was reached recently: the collaboration obtained the first result on the search for 13 based on 100 days of data from the far detector. Our data indicates that 13 is not zero; specifically the best fit of the neutrino oscillation hypothesis to our data gives sin2 (2 13) = 0.086 ± 0.041 (stat) ± 0.030 (syst) The null oscillation hypothesis is excluded at the 94.6% C.L. This result1 has been submitted to Physical Review Letters. As we continue to take data with the far detector in the coming year, in parallel with completing the construction of the near lab and installing the near detector, we expect the precision of our measurement to improve as we gather significantly more statistics, gain better control of backgrounds through use of partial power data and improved event selection, and better understand the detector energy scale and detection efficiency from calibration data. With both detectors taking data starting in the second half of 2013, we expect to further drive down the uncertainty on our measurement of sin2 (2 13) to less than 0.02. Stancu’s group is also collaborating on the MiniBooNE experiment. Data taking is scheduled to continue through April, by which time 1.18 × 1021 POT is projected. The UA group is playing a leading role in the measurement of antineutrino cross sections, which should be the subject of a publication later this year as well as of Ranjan Dharmapalan’s Ph.D. thesis, which he is expected to defend by the end of this year. It is time to begin working on projects which will eventually succeed Double Chooz and MiniBooNE as the main foci of our efforts. The Stancu group plans to become re–involved in LBNE and possibly also to join NO A, and the Busenitz group has begun to explore joining a direct dark matter search.

  15. Synchrotron Radiation in Polymer Science

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Synchrotron Radiation in Polymer Science Synchrotron Radiation in Polymer Science March 30-April 2, 2012; San Francisco...

  16. Synchrotron Radiation in Polymer Science

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Synchrotron Radiation in Polymer Science Synchrotron Radiation in Polymer Science March 30-April 2, 2012; San Francisco

  17. Dynamical principles in neuroscience

    SciTech Connect (OSTI)

    Rabinovich, Mikhail I.; Varona, Pablo; Selverston, Allen I.; Abarbanel, Henry D. I.

    2006-10-15

    Dynamical modeling of neural systems and brain functions has a history of success over the last half century. This includes, for example, the explanation and prediction of some features of neural rhythmic behaviors. Many interesting dynamical models of learning and memory based on physiological experiments have been suggested over the last two decades. Dynamical models even of consciousness now exist. Usually these models and results are based on traditional approaches and paradigms of nonlinear dynamics including dynamical chaos. Neural systems are, however, an unusual subject for nonlinear dynamics for several reasons: (i) Even the simplest neural network, with only a few neurons and synaptic connections, has an enormous number of variables and control parameters. These make neural systems adaptive and flexible, and are critical to their biological function. (ii) In contrast to traditional physical systems described by well-known basic principles, first principles governing the dynamics of neural systems are unknown. (iii) Many different neural systems exhibit similar dynamics despite having different architectures and different levels of complexity. (iv) The network architecture and connection strengths are usually not known in detail and therefore the dynamical analysis must, in some sense, be probabilistic. (v) Since nervous systems are able to organize behavior based on sensory inputs, the dynamical modeling of these systems has to explain the transformation of temporal information into combinatorial or combinatorial-temporal codes, and vice versa, for memory and recognition. In this review these problems are discussed in the context of addressing the stimulating questions: What can neuroscience learn from nonlinear dynamics, and what can nonlinear dynamics learn from neuroscience?.

  18. Honeycomb superlattice pattern in a dielectric barrier discharge in

    Office of Scientific and Technical Information (OSTI)

    argon/air (Journal Article) | SciTech Connect Honeycomb superlattice pattern in a dielectric barrier discharge in argon/air Citation Details In-Document Search Title: Honeycomb superlattice pattern in a dielectric barrier discharge in argon/air We report on a honeycomb superlattice pattern in a dielectric barrier discharge in argon/air for the first time. It consists of hexagon lattice and honeycomb framework and bifurcates from a hexagon pattern as the applied voltage increases. A phase

  19. Electronic Structure Changes in Supercapacitor Electrodes Observed In

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Operando Electronic Structure Changes in Supercapacitor Electrodes Observed In Operando Electronic Structure Changes in Supercapacitor Electrodes Observed In Operando Print Monday, 09 March 2015 16:58 Profound bias- and time-dependent changes in the electronic structure of graphene-based supercapacitor electrodes are demonstrated under operating conditions via a combination of in operando x-ray spectroscopy and ab initio modeling by J.R.I. Lee and co-workers. The evolution in electronic

  20. CRYOGENICS IN BEPCII UPGRADE.

    SciTech Connect (OSTI)

    JIA,L.; WANG,L.; LI,S.

    2002-07-22

    THIS PAPER PRESENTS A CRYOGENIC DESIGN FOR UPGRADING THE BEIJING ELECTRON POSITRON COLLIDER AT THE INSTITUTE OF HIGH ENERGY PHYSICS IN BEIJING. THE UPGRADE INVOLVES 3 NEW SUPERCONDUCTING FACILITIES, THE INTERACTION REGION QUADRUPOLE MAGNETS, THE DETECTOR SOLENOID MAGNETS AND THE SRF CAVITIES. FOR COOLING OF THESE DEVICES, A NEW CRYPLANT WITH A TOTAL CAPACITY OF 1.0KW AT 4.5K IS TO BE BUILT AT IHEP. AN INTEGRATED CRYOGENIC DESIGN TO FIT THE BEPCII CRYOGENIC LOADS WITH HIGH EFFICIENCY IS CARRIEDOUT USING COMPUTATIONAL PROCESS ANALYSIS SOFTWARE WITH THE EMPHASES ON ECONOMICS AND SAFETY IN BOTH CONSTRUCTION AND OPERATION OF THE PLANT. THIS PAPER DESCRIBES THE CRYOGENIC CHARACTERISTICS OF EACH SUPERCONDUCTING DEVICE, THEIR COOLING SCHEMES AND THE OVERALL CRYOPLANT.

  1. Counting paths in digraphs

    SciTech Connect (OSTI)

    Sullivan, Blair D; Seymour, Dr. Paul Douglas

    2010-01-01

    Say a digraph is k-free if it has no directed cycles of length at most k, for k {element_of} Z{sup +}. Thomasse conjectured that the number of induced 3-vertex directed paths in a simple 2-free digraph on n vertices is at most (n-1)n(n+1)/15. We present an unpublished result of Bondy proving there are at most 2n{sup 3}/25 such paths, and prove that for the class of circular interval digraphs, an upper bound of n{sup 3}/16 holds. We also study the problem of bounding the number of (non-induced) 4-vertex paths in 3-free digraphs. We show an upper bound of 4n{sup 4}/75 using Bondy's result for Thomasse's conjecture.

  2. Energy in the Wind

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Provi and BP Energy in the Wind - Exploring Basic Electrical Concepts by Modeling Wind Turbines Curriculum: Wind Power (simple machines, aerodynamics, weather/climatology, leverage, mechanics, atmospheric pressure, and energy resources/transformations) Grade Level: High School Small groups: 2 students Time: Introductory packet will take 2-3 periods. Scientific investigation will take 2-3 periods. (45-50 minute periods) Summary: Students explore basic electrical concepts. Students are introduced

  3. Photovoltaics in the Classroom

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Photovoltaics (PV) in the Classroom Workshop National Renewable Energy Laboratory 1617 Cole Boulevard Golden, Colorado 80401-3393 National Renewable Energy Laboratory 2 National Renewable Energy Laboratory 1617 Cole Boulevard Golden, Colorado 80401-3393 NREL is a U.S. Department of Energy National Laboratory Operated by Midwest Research Institute * Battelle * Bechtel NREL/PublicationCode June 1999 NOTICE This report was prepared as an account of work sponsored by an agency of the United States

  4. lighting in the library

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The amount and quality of light around us affects our health, safety, comfort, and productivity. Our country spends more than $37 billion each year on electricity for lighting, but technologies developed during the past 10 years can help us cut lighting costs by 30% to 60% while enhancing lighting quality and reducing environmental impacts. In a typical indoor lighting system, 50 percent or more of the energy supplied to the lamp can be wasted by obsolete equipment, poor maintenance, or

  5. Environmental renaissance in Pennsylvania

    SciTech Connect (OSTI)

    Stevens, J.

    2009-07-15

    During centuries of rapid growth of the coal mining industry and expanded development in Pennsylvania, trees were felled, streams were diverted and strip mining caused much environmental damage. All that has now changed. The article gives examples of land and water restoration carried out by organizations such as the Susquehanna River Basin Commission, the West Branch Susquehanna Restoration Coalition and the Anthracite Region Independent Power Producers Association. The Pennsylvania Department of Environmental Protection directs and coordinates environmental projects. 5 photos.

  6. NERSC in the News

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Microscopy Reveals 'Atomic Antenna' Behavior in Graphene January 21, 2012 | Reanalysis Project targets once-and-future weather September 29, 2010 | Source: ASCR Discovery | Gil Compo describes the 20th Century Reanalysis Project that he leads for the National Oceanic and Atmospheric Administration. The project relies on 150 years of weather data and simulations run on Department of Energy supercomputers. http://ascr-discovery.science.doe.gov peptidefig.jpg Team ratchets up accuracy for

  7. PROGRESS IN RESEARCH

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    7 - March 31, 2008 CYCLOTRON INSTITUTE Texas A&M University College Station, Texas PROGRESS IN RESEARCH APRIL 1, 2007 - MARCH 31, 2008 Prepared By The Cyclotron Institute Staff Texas A&M University College Station, TX 77843-3366 Phone: (979) 845-1411 Fax: (979) 845-1899 Web: http://cyclotron.tamu.edu July 2008 TABLE OF CONTENTS Introduction .............................................................................................................................................viii

  8. PROGRESS IN RESEARCH

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    8 - March 31, 2009 CYCLOTRON INSTITUTE Texas A&M University College Station, Texas PROGRESS IN RESEARCH APRIL 1, 2008- MARCH 31, 2009 Prepared By The Cyclotron Institute Staff Texas A&M University College Station, TX 77843-3366 Phone: (979) 845-1411 Fax: (979) 845-1899 Web: http://cyclotron.tamu.edu August 2009 TABLE OF CONTENTS Introduction ................................................................................................................................................ x

  9. PROGRESS IN RESEARCH

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    9 - March 31, 2010 CYCLOTRON INSTITUTE Texas A&M University College Station, Texas PROGRESS IN RESEARCH APRIL 1, 2009- MARCH 31, 2010 Prepared By The Cyclotron Institute Staff Texas A&M University College Station, TX 77843-3366 Phone: (979) 845-1411 Fax: (979) 845-1899 Web: http://cyclotron.tamu.edu June 2010 i TABLE OF CONTENTS Introduction ................................................................................................................................................ x

  10. PROGRESS IN RESEARCH

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    0 - March 31, 2011 CYCLOTRON INSTITUTE Texas A&M University College Station, Texas PROGRESS IN RESEARCH APRIL 1, 2010- MARCH 31, 2011 Prepared By The Cyclotron Institute Staff Texas A&M University College Station, TX 77843-3366 Phone: (979) 845-1411 Fax: (979) 845-1899 Web: http://cyclotron.tamu.edu August 2011 i TABLE OF CONTENTS Introduction ................................................................................................................................................ x

  11. Publication in Ocean Engineering

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Publication in Ocean Engineering - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Fuel Cycle Defense Waste Management Programs

  12. Materials in the news

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    News Materials in the news Discover more about the wide-ranging scope of materials research at Los Alamos National Laboratory. Contact Us ADEPS Communications Email Scientists Aditya Mohite, left, and Wanyi Nie are perfecting a crystal production technique to improve perovskite crystal production for solar cells Scientists Aditya Mohite, left, and Wanyi Nie are perfecting a crystal production technique to improve perovskite crystal production for solar cells Read more... Materials science at Los

  13. Frontiers in Geoscience Colloquium

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    8, 2 016 3:00pm - 4 :00pm Physics A uditorium ( TA---3, B ldg 2 15) An Introduction to the Underground Nuclear Explosion Signatures Experiment Aviva J . Sussman EES---17. L ANL N ational security priorities include global nuclear explosion monitoring to determine the detection, location, and identification of suspected nuclear explosions. Such monitoring currently relies on sensor networks; in some cases, prompt signals may not provide sufficient locations and the timing and amplitude of

  14. Understanding the Decline in Carbon Dioxide Emissions in 2009 (Released in the STEO October 2009)

    Reports and Publications (EIA)

    2009-01-01

    The Energy Information Administration forecasts 5.9% decline in U.S. carbon dioxide emissions in 2009.

  15. Instabilities in the aether

    SciTech Connect (OSTI)

    Carroll, Sean M.; Dulaney, Timothy R.; Gresham, Moira I.; Tam, Heywood

    2009-03-15

    We investigate the stability of theories in which Lorentz invariance is spontaneously broken by fixed-norm vector 'aether' fields. Models with generic kinetic terms are plagued either by ghosts or by tachyons, and are therefore physically unacceptable. There are precisely three kinetic terms that are not manifestly unstable: a sigma model ({partial_derivative}{sub {mu}}A{sub {nu}}){sup 2}, the Maxwell Lagrangian F{sub {mu}}{sub {nu}}F{sup {mu}}{sup {nu}}, and a scalar Lagrangian ({partial_derivative}{sub {mu}}A{sup {mu}}){sup 2}. The timelike sigma-model case is well defined and stable when the vector norm is fixed by a constraint; however, when it is determined by minimizing a potential there is necessarily a tachyonic ghost, and therefore an instability. In the Maxwell and scalar cases, the Hamiltonian is unbounded below, but at the level of perturbation theory there are fewer degrees of freedom and the models are stable. However, in these two theories there are obstacles to smooth evolution for certain choices of initial data.

  16. Programs in Renewable Energy

    SciTech Connect (OSTI)

    Not Available

    1990-01-01

    Our nation faces significant challenges as we enter the 1990s: securing a reliable supply of competitively priced energy, improving the quality of our environment, and increasing our share of foreign markets for goods and services. The US Department of Energy's (DOE) Programs in Renewable Energy are working toward meeting these challenges by developing the technologies that make use of our nation's largest energy resource: renewable energy. The sunlight, wind biomass, flowing water, ocean energy, and geothermal energy that make up the renewable energy resource can be found throughout our nation. These resources can provide all the forms of energy our nation needs: liquid fuels, electricity, and heating and cooling. Renewable energy meets about 10% of our need for these forms of energy today, yet the potential contribution is many times greater. DOE's Programs in Renewable Energy are working side-by-side with American industry to develop the technologies that convert renewable energy resources into practical, cost-competitive energy. After a decade of progress in research, several of these technologies are poised to make large contributions during the 1990s and beyond. This booklet provides an overview of the renewable energy programs and their plans for FY 1990. Sources of additional information are listed at the back of the booklet. 48 figs., 4 tabs.

  17. Charged pion production in $$\

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Eberly, B.; et al.

    2015-11-23

    Charged pion production via charged-current νμ interactions on plastic scintillator (CH) is studied using the MINERvA detector exposed to the NuMI wideband neutrino beam at Fermilab. Events with hadronic invariant mass W < 1.4 GeV and W < 1.8 GeV are selected in separate analyses: the lower W cut isolates single pion production, which is expected to occur primarily through the Δ(1232) resonance, while results from the higher cut include the effects of higher resonances. Cross sections as functions of pion angle and kinetic energy are compared to predictions from theoretical calculations and generator-based models for neutrinos ranging in energymore » from 1.5–10 GeV. The data are best described by calculations which include significant contributions from pion intranuclear rescattering. As a result, these measurements constrain the primary interaction rate and the role of final state interactions in pion production, both of which need to be well understood by neutrino oscillation experiments.« less

  18. World Oil Prices in AEO2006 (released in AEO2006)

    Reports and Publications (EIA)

    2006-01-01

    World oil prices in the Annual Energy Outlook 2006 (AEO) reference case are substantially higher than those in the AEO2005 reference case. In the AEO2006 reference case, world crude oil prices, in terms of the average price of imported low-sulfur, light crude oil to U.S. refiners, decline from current levels to about $47 per barrel (2004 dollars) in 2014, then rise to $54 per barrel in 2025 and $57 per barrel in 2030. The price in 2025 is approximately $21 per barrel higher than the corresponding price projection in the AEO2005 reference case.

  19. Lithium electrodeposition dynamics in aprotic electrolyte observed in situ

    Office of Scientific and Technical Information (OSTI)

    via transmission electron microscopy (Journal Article) | SciTech Connect Journal Article: Lithium electrodeposition dynamics in aprotic electrolyte observed in situ via transmission electron microscopy Citation Details In-Document Search Title: Lithium electrodeposition dynamics in aprotic electrolyte observed in situ via transmission electron microscopy Electrodeposited metallic lithium is an ideal negative battery electrode, but nonuniform microstructure evolution during cycling leads to

  20. Overview of Progress in Thermoelectric Power Generation Technologies in

    Broader source: Energy.gov (indexed) [DOE]

    Japan | Department of Energy Presents progress in government- and private-funded thermoelectric power generation R&D in Japan PDF icon kajikawa.pdf More Documents & Publications Overview of Thermoelectric Power Generation Technologies in Japan Overview of Thermoelectric Power Generation Technologies in Japan Overview of Japanese Activities in Thermoelectrics

  1. Growth in global oil inventories slows, drawdown in stocks expected...

    U.S. Energy Information Administration (EIA) Indexed Site

    to stronger growth in world oil demand, with ... In its new monthly forecast, the U.S. Energy Information ... will be led by stronger fuel consumption in China and India. ...

  2. Mercury control in 2009

    SciTech Connect (OSTI)

    Sjostrom, S.; Durham, M.; Bustard, J.; Martin, C.

    2009-07-15

    Although activated carbon injection (ACI) has been proven to be effective for many configurations and is a preferred option at many plants sufficient quantities of powdered activated coking (PAC) must be available to meet future needs. The authors estimate that upcoming federal and state regulations will result in tripling the annual US demand for activated carbon to nearly 1.5 billion lb from approximately 450 million lb. Rapid expansion of US production capacity is required. Many PAC manufacturers are discussing expansion of their existing production capabilities. One company, ADA Carbon Solutions, is in the process of constructing the largest activated carbon facility in North America to meet the future demand for PAC as a sorbent for mercury control. Emission control technology development and commercialization is driven by regulation and legislation. Although ACI will not achieve > 90% mercury control at every plant, the expected required MACT legislation level, it offers promise as a low-cost primary mercury control technology option for many configurations and an important trim technology for others. ACI has emerged as the clear mercury-specific control option of choice, representing over 98% of the commercial mercury control system orders to date. As state regulations are implemented and the potential for a federal rule becomes more imminent, suppliers are continuing to develop technologies to improve the cost effectiveness and limit the balance of plant impacts associated with ACI and are developing additional PAC production capabilities to ensure that the industry's needs are met. The commercialisation of ACI is a clear example of industry, through the dedication of many individuals and companies with support from the DOE and EPRI, meeting the challenge of developing cost-effectively reducing emissions from coal-fired power plants. 7 refs., 1 fig.

  3. Topics in inflationary cosmologies

    SciTech Connect (OSTI)

    Mahajan, S.

    1986-04-01

    Several aspects of inflationary cosmologies are discussed. An introduction to the standard hot big bang cosmological model is reviewed, and some of the problems associated with it are presented. A short review of the proposals for solving the cosmological conundrums of the big bang model is presented. Old and the new inflationary scenarios are discussed and shown to be unacceptable. Some alternative scenarios especially those using supersymmetry are reviewed briefly. A study is given of inflationary models where the same set of fields that breaks supersymmetry is also responsible for inflation. In these models, the scale of supersymmetry breaking is related to the slope of the potential near the origin and can thus be kept low. It is found that a supersymmetry breaking scale of the order of the weak breaking scale. The cosmology obtained from the simplest of such models is discussed in detail and it is shown that there are no particular problems except a low reheating temperature and a violation of the thermal constraint. A possible solution to the thermal constraint problem is given by introducing a second field, and the role played by this second field in the scenario is discussed. An alternative mechanism for the generation of baryon number within the framework of supergravity inflationary models is studied using the gravitational couplings of the heavy fields with the hidden sector (the sector which breaks supersymmetry). This mechanism is applied to two specific models - one with and one without supersymmetry breaking. The baryon to entropy ratio is found to be dependent on parameters which are model dependent. Finally, the effect of direct coupling between the two sectors on results is related, 88 refs., 6 figs.

  4. Lasers in materials processing

    SciTech Connect (OSTI)

    Davis, J.I.; Rockower, E.B.

    1981-01-01

    A status report on the uranium Laser Isotope Separation (LIS) Program at the Lawrence Livermore National Laboratory is presented. Prior to this status report, process economic analysis is presented so as to understand how the unique properties of laser photons can be best utilized in the production of materials and components despite the high cost of laser energy. The characteristics of potential applications that are necessary for success are identified, and those factors that have up to now frustrated attempts to find commercially viable laser induced chemical and physical process for the production of new or existing materials are pointed out.

  5. There's gold in garbage

    SciTech Connect (OSTI)

    Pollock, C. )

    1987-03-01

    We haven't begun to mine wealth in the world's wastes, but still insist on burying it - even while cities are running out of landfill space. Most of the products available to consumers are purchased, consumed and tossed with little regard for their remaining value. The energy, materials, and environmental losses associated with this consumption pattern are staggering. Recycling offers the opportunity to trim waste-disposal needs, simultaneously reducing disposal costs and combating global environmental problems. Recycling metals, paper, glass, plastics, and organic wastes lessens the demand for energy and materials.

  6. EVENTS IN PROGRESS September

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2016 | Department of Energy EVENT: 2016 DOE ADVANCED MANUFACTURING OFFICE PEER REVIEW - JUNE 14-15, 2016 EVENT: 2016 DOE ADVANCED MANUFACTURING OFFICE PEER REVIEW - JUNE 14-15, 2016 June 14, 2016 8:00AM to 5:00PM EDT The Energy Efficiency and Renewable Energy's Advanced Manufacturing Office will hold a Peer Review of its Research and Development Projects, Research and Development Facilities and Analysis activities at the Key Bridge Marriott in Rosslyn, Virginia on June 14-15, 2016. This

  7. Jets in QCD

    SciTech Connect (OSTI)

    Seymour, M.H.

    1996-02-01

    Many analyses at the collider utilize the hadronic jets that are the footprints of QCD partons. These are used both to study the QCD processes themselves and increasingly as tools to study other physics, for example top mass reconstruction. However, jets are not fundamental degrees of freedom in the theory, so we need an {ital operational} {ital jet} {ital definition} and {ital reliable} {ital methods} {ital to} {ital calculate} {ital their} {ital properties}. This talk covers both of these important areas of jet physics. {copyright} {ital 1996 American Institute of Physics.}

  8. Angular Scaling In Jets

    SciTech Connect (OSTI)

    Jankowiak, Martin; Larkoski, Andrew J.; /SLAC

    2012-02-17

    We introduce a jet shape observable defined for an ensemble of jets in terms of two-particle angular correlations and a resolution parameter R. This quantity is infrared and collinear safe and can be interpreted as a scaling exponent for the angular distribution of mass inside the jet. For small R it is close to the value 2 as a consequence of the approximately scale invariant QCD dynamics. For large R it is sensitive to non-perturbative effects. We describe the use of this correlation function for tests of QCD, for studying underlying event and pile-up effects, and for tuning Monte Carlo event generators.

  9. transims-in-buffalo

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in the Buffalo / Niagara Falls Area Scott B. Smith, Ph.D. US DOT / RITA / Volpe Center / RVT-91 Room 1-450 55 Broadway Cambridge, MA 02142 phone 617-494-2588 fax 617-494-3260 This email address is being protected from spambots. You need JavaScript enabled to view it. List of Authors ================ Scott Smith Abstract ========= TRANSIMS was used to develop an integrated planning / simulation model of the Buffalo / Niagara Falls area. The planning model encompasses the U.S. side of the entire

  10. Components in the Pipeline

    SciTech Connect (OSTI)

    Gorton, Ian; Wynne, Adam S.; Liu, Yan; Yin, Jian

    2011-02-24

    Scientists commonly describe their data processing systems metaphorically as software pipelines. These pipelines input one or more data sources and apply a sequence of processing steps to transform the data and create useful results. While conceptually simple, pipelines often adopt complex topologies and must meet stringent quality of service requirements that place stress on the software infrastructure used to construct the pipeline. In this paper we describe the MeDICi Integration Framework, which is a component-based framework for constructing complex software pipelines. The framework supports composing pipelines from distributed heterogeneous software components and provides mechanisms for controlling qualities of service to meet demanding performance, reliability and communication requirements.

  11. Environment scattering in GADRAS.

    SciTech Connect (OSTI)

    Thoreson, Gregory G.; Mitchell, Dean James; Theisen, Lisa Anne; Harding, Lee T.

    2013-09-01

    Radiation transport calculations were performed to compute the angular tallies for scattered gamma-rays as a function of distance, height, and environment. Green's Functions were then used to encapsulate the results a reusable transformation function. The calculations represent the transport of photons throughout scattering surfaces that surround sources and detectors, such as the ground and walls. Utilization of these calculations in GADRAS (Gamma Detector Response and Analysis Software) enables accurate computation of environmental scattering for a variety of environments and source configurations. This capability, which agrees well with numerous experimental benchmark measurements, is now deployed with GADRAS Version 18.2 as the basis for the computation of scattered radiation.

  12. Electron screening in nickel

    SciTech Connect (OSTI)

    Gajevic, Jelena; Lipoglavsek, Matej; Petrovic, Toni; Pelicon, Primoz

    2012-10-20

    In order to investigate the interplay between nuclei and their surroundings we studied proton induced nuclear reactions over an energy range from 1.35 to 3.08 MeV for different environments: Ni metal and NiO insulator. The measurements were based on observation of the {gamma}-ray yields of {sup 59,61,63,64,65}Cu and {sup 58,60,62}Ni. The presented results clearly show that the metallic environment affects the fusion reactions at low energies.

  13. Cycles in fossil diversity

    SciTech Connect (OSTI)

    Rohde, Robert A.; Muller, Richard A.

    2004-10-20

    It is well-known that the diversity of life appears to fluctuate during the course the Phanerozoic, the eon during which hard shells and skeletons left abundant fossils (0-542 Ma). Using Sepkoski's compendium of the first and last stratigraphic appearances of 36380 marine genera, we report a strong 62 {+-} 3 Myr cycle, which is particularly strong in the shorter-lived genera. The five great extinctions enumerated by Raup and Sepkoski may be an aspect of this cycle. Because of the high statistical significance, we also consider contributing environmental factors and possible causes.

  14. Studies in combustion dynamics

    SciTech Connect (OSTI)

    Koszykowski, M.L.

    1993-12-01

    The goal of this program is to develop a fundamental understanding and a quantitative predictive capability in combustion modeling. A large part of the understanding of the chemistry of combustion processes comes from {open_quotes}chemical kinetic modeling.{close_quotes} However, successful modeling is not an isolated activity. It necessarily involves the integration of methods and results from several diverse disciplines and activities including theoretical chemistry, elementary reaction kinetics, fluid mechanics and computational science. Recently the authors have developed and utilized new tools for parallel processing to implement the first numerical model of a turbulent diffusion flame including a {open_quotes}full{close_quotes} chemical mechanism.

  15. Predetermining acceptable noise limits in EXAFS spectra in the...

    Office of Scientific and Technical Information (OSTI)

    Title: Predetermining acceptable noise limits in EXAFS spectra in the limit of stochastic noise EXAFS measurements are used to probe a variety of experimental systems, but excel at ...

  16. Shared Space vs. In-Unit Upgrades in Multifamily Buildings

    Broader source: Energy.gov [DOE]

    Better Buildings Neighborhood Program Multifamily Peer Exchange Call: Shared Space vs. In-Unit Upgrades in Multifamily Buildings, Call Slides and Summary, May 9, 2013.

  17. Plasmas in Multiphase Media: Bubble Enhanced Discharges in Liquids...

    Office of Scientific and Technical Information (OSTI)

    of atmospheric pressure plasmas in the form of dielectric barrier discharges and plasma jets with organic materials and liquids. We also made advances in our ability to use...

  18. First in-situ images of void collapse in explosives

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    First in-situ images of void collapse in explosives First in-situ images of void collapse in explosives Los Alamos researchers and collaborators demonstrated a crucial diagnostic for studying how voids affect explosives under shock loading. July 24, 2014 Dynamic x-ray image of void collapse in shocked explosive. The void (bright spot in the center) collapses as the shock wave passes through it. Dynamic x-ray image of void collapse in shocked explosive. The void (bright spot in the center)

  19. Phylogenetic trees in bioinformatics

    SciTech Connect (OSTI)

    Burr, Tom L

    2008-01-01

    Genetic data is often used to infer evolutionary relationships among a collection of viruses, bacteria, animal or plant species, or other operational taxonomic units (OTU). A phylogenetic tree depicts such relationships and provides a visual representation of the estimated branching order of the OTUs. Tree estimation is unique for several reasons, including: the types of data used to represent each OTU; the use ofprobabilistic nucleotide substitution models; the inference goals involving both tree topology and branch length, and the huge number of possible trees for a given sample of a very modest number of OTUs, which implies that fmding the best tree(s) to describe the genetic data for each OTU is computationally demanding. Bioinformatics is too large a field to review here. We focus on that aspect of bioinformatics that includes study of similarities in genetic data from multiple OTUs. Although research questions are diverse, a common underlying challenge is to estimate the evolutionary history of the OTUs. Therefore, this paper reviews the role of phylogenetic tree estimation in bioinformatics, available methods and software, and identifies areas for additional research and development.

  20. Hybrid baryons in QCD

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dudek, Jozef J.; Edwards, Robert G.

    2012-03-21

    In this study, we present the first comprehensive study of hybrid baryons using lattice QCD methods. Using a large basis of composite QCD interpolating fields we extract an extensive spectrum of baryon states and isolate those of hybrid character using their relatively large overlap onto operators which sample gluonic excitations. We consider the spectrum of Nucleon and Delta states at several quark masses finding a set of positive parity hybrid baryons with quantum numbersmore » $$N_{1/2^+},\\,N_{1/2^+},\\,N_{3/2^+},\\, N_{3/2^+},\\,N_{5/2^+},\\,$$ and $$\\Delta_{1/2^+},\\, \\Delta_{3/2^+}$$ at an energy scale above the first band of `conventional' excited positive parity baryons. This pattern of states is compatible with a color octet gluonic excitation having $$J^{P}=1^{+}$$ as previously reported in the hybrid meson sector and with a comparable energy scale for the excitation, suggesting a common bound-state construction for hybrid mesons and baryons.« less

  1. Detectors in Extreme Conditions

    SciTech Connect (OSTI)

    Blaj, G.; Carini, G.; Carron, S.; Haller, G.; Hart, P.; Hasi, J.; Herrmann, S.; Kenney, C.; Segal, J.; Tomada, A.

    2015-08-06

    Free Electron Lasers opened a new window on imaging the motion of atoms and molecules. At SLAC, FEL experiments are performed at LCLS using 120Hz pulses with 1012 - 1013 photons in 10 femtoseconds (billions of times brighter than the most powerful synchrotrons). This extreme detection environment raises unique challenges, from obvious to surprising. Radiation damage is a constant threat due to accidental exposure to insufficiently attenuated beam, focused beam and formation of ice crystals reflecting the beam onto the detector. Often high power optical lasers are also used (e.g., 25TW), increasing the risk of damage or impeding data acquisition through electromagnetic pulses (EMP). The sample can contaminate the detector surface or even produce shrapnel damage. Some experiments require ultra high vacuum (UHV) with strict design, surface contamination and cooling requirements - also for detectors. The setup is often changed between or during experiments with short turnaround times, risking mechanical and ESD damage, requiring work planning, training of operators and sometimes continuous participation of the LCLS Detector Group in the experiments. The detectors used most often at LCLS are CSPAD cameras for hard x-rays and pnCCDs for soft x-rays.

  2. Turbines in the ocean

    SciTech Connect (OSTI)

    Smith, F.G.W.; Charlier, R.H.

    1981-09-01

    It is noted that the relatively high-speed ocean currents flowing northward along the east coast of the U.S. may be able to supply a significant proportion of the future electric power requirements of urban areas. The Gulf Stream core lies only about 20 miles east of Miami here its near-surface water reaches velocities of 4.3 miles per hour. Attention is called to the estimate that the energy available in the current of the Gulf Stream adjacent to Florida is approximately equivalent to that generated by 25 1,000-megawatt power plants. It is also contended that this power could be produced at competitive prices during the 1980s using large turbines moored below the ocean surface near the center of the Stream. Assuming an average ocean-current speed between 4 and 5 knots at the current core, the power density of a hydroturbine could reach 410 watts per square foot, about 100 times that of a wind-driven device of similar scale operating in an airflow of approximately 11 knots.

  3. Lead in human blood from children living in Campania, Italy

    SciTech Connect (OSTI)

    Amodio-Cocchieri, R.; Arnese, A.; Prospero, E.; Roncioni, A.

    1996-03-01

    Blood lead (PbB) levels were determined in children living Campania (in Naples and in a rural zone in the district of Caserta). Atmospheric lead (PbA) concentration in these considered areas was monitored for 1 yr (1993-1994). The children tested were questioned about common sources of lead, other than atmospheric relating to their living and dietary habits. The PbB levels in children living in Naples were at the 50th percentile, 18.8 {mu}g/dl in males and 13.7 {mu}g/dl in females; in children living in the rural area the median PbB levels were 8.9{mu}g/dl in males, and 9.9 {mu}g/dl in females. The annual mean values of atmospheres lead were 1.15 {plus_minus} 0.24 {mu}g/dl in Naples and 0.23 {plus_minus} 0.07 {mu}g/dl in the rural area. Significant and congruent mean differences between urban and rural sites were found in children`s blood and concurrent air lead. Considering the PbB level of 10 {mu}g/dl as the maximum level that is not associated any known adverse effect in children, the Neapolitan group can be considered at risk of chronic intoxication by lead. 18 refs., 3 figs., 4 tabs.

  4. PORTSMOUTH 2015 YEAR IN REVIEW

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... This effort generated more than 40,000 in proceeds to assist SODI in its economic development mission in Jackson, Pike, Ross and Scioto counties. It also allowed DOE to save more ...

  5. Decoding dark matter in genes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Decoding dark matter in genes Decoding dark matter in genes Possible future applications, for example, include making new cancer therapies based on how ribosomes differentiate in healthy versus cancerous tissue. February 19, 2016 Decoding dark matter in genes In 1994, researchers from Harvard and Stanford published a paper in which they described three mice: one was yellow and fat, one mottled and fat, and the last one was brown and lean. An ordinary image, except for one thing: despite being so

  6. Piezoelectric effect in InAs/InP quantum rod nanowires grown on silicon substrate

    SciTech Connect (OSTI)

    Anufriev, Roman; Chauvin, Nicolas Bru-Chevallier, Catherine; Khmissi, Hammadi; Naji, Khalid; Gendry, Michel; Patriarche, Gilles

    2014-05-05

    We report on the evidence of a strain-induced piezoelectric field in wurtzite InAs/InP quantum rod nanowires. This electric field, caused by the lattice mismatch between InAs and InP, results in the quantum confined Stark effect and, as a consequence, affects the optical properties of the nanowire heterostructure. It is shown that the piezoelectric field can be screened by photogenerated carriers or removed by increasing temperature. Moreover, a dependence of the piezoelectric field on the quantum rod diameter is observed in agreement with simulations of wurtzite InAs/InP quantum rod nanowire heterostructures.

  7. Safety Culture in Nuclear Installations

    Broader source: Energy.gov [DOE]

    IAEA-TECDOC-1329 Safety Culture in Nuclear Installations, Guidance for use in the Enhancement of Safety Culture, International Atomic Energy Agency IAEA, December 2002.

  8. Ultrafast Transformations in Superionic Nanocrystals

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Michael Faraday almost 200 years ago, superionic materials today hold promise for use in resistive switching devices, which follow from their abrupt changes in ionic mobility, as...

  9. Surprising Quasiparticle Interactions in Graphene

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    graphene offers a new regime to study relativistic particle physics, not in large high-energy accelerators, but rather under ambient conditions in a solid. The atomic...

  10. Fuel Cells in the States

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    in the Fuel Cells in the States States State and Regional State and Regional Initiatives ... Jennifer Gangi Jennifer Gangi Program Director Program Director Fuel Cells 2000 Fuel Cells ...

  11. Progress in solar engineering

    SciTech Connect (OSTI)

    Yogi Goswami, D.

    1987-01-01

    This book presents reviews of various areas of solar energy technology, including wind energy technology and ocean thermal energy conversion (OTEC). It also identifies and suggests needs and future directions of research and development. The subjects covered in this book include solar thermal power technology, solar thermal storage, solar ponds, industrial process heat, solar water heating, active and passive solar cooling methods, low-cost collector development, photovoltaic research and applications, wind energy technology, and OTEC. Also covered are the status of the technology, basic and applied research, design and analysis methods, and performance and operational experiences of various systems. The book will thus be helpful as a review of various solar, wind, and OTEC technologies.

  12. TARANTULA 2011 in JWL++

    SciTech Connect (OSTI)

    Souers, P C; Haylett, D; Vitello, P

    2011-10-27

    Using square zoning, the 2011 version of the kinetic package Tarantula matches cylinder data, cylinder dead zones, and cylinder failure with the same settings for the first time. The key is the use of maximum pressure rather than instantaneous pressure. Runs are at 40, 200 and 360 z/cm using JWL++ as the host model. The model also does run-to-detonation, thin-pulse initiation with a P-t curve and air gap crossing, all in cylindrical geometry. Two sizes of MSAD/LX-10/LX-17 snowballs work somewhat with these settings, but are too weak, so that divergent detonation is a challenge for the future. Butterfly meshes are considered but do not appear to solve the issue.

  13. Comparative mutagenesis of human cells in vivo and in vitro

    SciTech Connect (OSTI)

    Thilly, W.G.

    1992-05-01

    This report discusses measuring methods of point mutations; high density cell cultures for low dose studies; measurement and sequence determination of mutations in DNA; the mutational spectra of styrene oxide and ethlyene oxide in TK-6 cells; mutational spectrum of Cr in human lymphoblast cells; mutational spectra of radon in TK-6 cells; and the mutational spectra of smokeless tobacco. (CBS)

  14. Oil and gas developments in Middle East in 1981

    SciTech Connect (OSTI)

    Hemer, D.O; Mason, J.F.; Hatch, G.C.

    1982-11-01

    Petroleum production in Middle East countries during 1981 totaled 5,741,096,000 bbl, or an average rate of 15,729,030 BOPD, down 14.9% from 1980. Increases were in Oman, Dubai, and Turkey. Significant decreases occurred in Iraq, Iran, Kuwait, Divided Neutral Zone, Qatar, and Abu Dhabi. New discoveries were made in Oman, Saudi Arabia, and Abu Dhabi.

  15. Charge Trapping in High Efficiency Alternating Copolymers: Implications in

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Organic Photovoltaic Device Efficiency | ANSER Center | Argonne-Northwestern National Laboratory Charge Trapping in High Efficiency Alternating Copolymers: Implications in Organic Photovoltaic Device Efficiency Home > Research > ANSER Research Highlights > Charge Trapping in High Efficiency Alternating Copolymers: Implications in Organic Photovoltaic Device Efficiency

  16. Lead contamination in the Mallard (Anas platyrhynchos) in Italy

    SciTech Connect (OSTI)

    Tirelli, E.; Maestrini, N.; Govoni, S.; Catelli, E.

    1996-05-01

    The main cause of lead poisoning in waterfowl is due to ingestion of spent lead shot in areas of high hunting pressure . Italian literature on this subject is very scarce and the few available studies concern episodic cases. to contribute to the assessment of the impact of lead shot in waterfowl in Italy, systematic research has been carried out on shorebirds caught for ringing in Tiscany and are continuing on dabbling and diving ducks by checking the presence of lead in blood samples and lead shot in the gizzard. This study targets the mallard duck. 17 refs., 1 fig., 1 tab.

  17. Oil and gas developments in North Africa in 1986

    SciTech Connect (OSTI)

    Michel, R.C.

    1987-10-01

    Licensed oil acreage in the 6 North Africa countries (Algeria, Egypt, Libya, Morocco, Sudan and Tunisia) totaled 1,500,000 km/sup 2/ at the end of 1986, down 290,000 km/sup 2/ from 1985. About 50% of the relinquishments were in Libya. Most oil and gas discoveries were made in Egypt (16 oil and 2 gas). Several oil finds were reported in onshore Libya, and 1 was reported in Algeria in the southeastern Sahara. According to available statistics, development drilling decreased from 1985 levels, except in Tunisia. A 6.3% decline in oil production took place in 1986, falling below the 3 million bbl level (2,912,000 b/d). Only sparse data are released on the gas output in North Africa. 6 figures, 27 tables.

  18. Progress in Understanding Iron Peak Elements in Young Supernova Remnants

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Progress in Understanding Iron Peak Elements in Young Supernova Remnants Citation Details In-Document Search Title: Progress in Understanding Iron Peak Elements in Young Supernova Remnants Authors: Eriksen, Kristoffer A. [1] ; Hughes, Jack [2] ; Fontes, Christopher J. [1] ; Colgan, James P. [1] ; Hungerford, Aimee L. [1] ; Fryer, Christopher L. [1] ; Zhang, Honglin [1] ; Badenes, Carles [3] ; Slane, Patrick [4] + Show Author Affiliations Los Alamos National

  19. Collective neutrino oscillations in supernovae

    SciTech Connect (OSTI)

    Duan, Huaiyu [Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131 (United States)

    2014-06-24

    In a dense neutrino medium neutrinos can experience collective flavor transformation through the neutrino-neutrino forward scattering. In this talk we present some basic features of collective neutrino flavor transformation in the context in core-collapse supernovae. We also give some qualitative arguments for why and when this interesting phenomenon may occur and how it may affect supernova nucleosynthesis.

  20. Log in | The Ames Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Error message Access denied. You must log in to view this page.

  1. Cooperative research in coal liquefaction

    SciTech Connect (OSTI)

    Huffman, G.P.; Sendlein, L.V.A. (eds.)

    1991-05-28

    Significant progress was made in the May 1990--May 1991 contract period in three primary coal liquefaction research areas: catalysis, structure-reactivity studies, and novel liquefaction processes. A brief summary of the accomplishments in the past year in each of these areas is given.

  2. Seating in Fermilab's, Ramsey Auditorium

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Seating in Fermilab's Ramsey Auditorium Photo courtesy of Peter Ginter. Ramsey Auditorium is located in Wilson Hall of Fermilab. It can seat up to 847 patrons, in rows shown below. When ordering your tickets, you can specify where in the Auditorium you would like your seats. Ramsey Auditorium Seating Chart

  3. Detonation in TATB Hemispheres

    SciTech Connect (OSTI)

    Druce, B; Souers, P C; Chow, C; Roeske, F; Vitello, P; Hrousis, C

    2004-03-17

    Streak camera breakout and Fabry-Perot interferometer data have been taken on the outer surface of 1.80 g/cm{sup 3} TATB hemispherical boosters initiated by slapper detonators at three temperatures. The slapper causes breakout to occur at 54{sup o} at ambient temperatures and 42{sup o} at -54 C, where the axis of rotation is 0{sup o}. The Fabry velocities may be associated with pressures, and these decrease for large timing delays in breakout seen at the colder temperatures. At room temperature, the Fabry pressures appear constant at all angles. Both fresh and decade-old explosive are tested and no difference is seen. The problem has been modeled with reactive flow. Adjustment of the JWL for temperature makes little difference, but cooling to -54 C decreases the rate constant by 1/6th. The problem was run both at constant density and with density differences using two different codes. The ambient code results show that a density difference is probably there but it cannot be quantified.

  4. Impurity gettering in semiconductors

    DOE Patents [OSTI]

    Sopori, B.L.

    1995-06-20

    A process for impurity gettering in a semiconductor substrate or device such as a silicon substrate or device is disclosed. The process comprises hydrogenating the substrate or device at the back side thereof with sufficient intensity and for a time period sufficient to produce a damaged back side. Thereafter, the substrate or device is illuminated with electromagnetic radiation at an intensity and for a time period sufficient to cause the impurities to diffuse to the back side and alloy with a metal there present to form a contact and capture the impurities. The impurity gettering process also can function to simultaneously passivate defects within the substrate or device, with the defects likewise diffusing to the back side for simultaneous passivation. Simultaneously, substantially all hydrogen-induced damage on the back side of the substrate or device is likewise annihilated. Also taught is an alternate process comprising thermal treatment after hydrogenation of the substrate or device at a temperature of from about 500 C to about 700 C for a time period sufficient to cause the impurities to diffuse to the damaged back side thereof for subsequent capture by an alloying metal. 1 fig.

  5. Impurity gettering in semiconductors

    DOE Patents [OSTI]

    Sopori, Bhushan L.

    1995-01-01

    A process for impurity gettering in a semiconductor substrate or device such as a silicon substrate or device. The process comprises hydrogenating the substrate or device at the back side thereof with sufficient intensity and for a time period sufficient to produce a damaged back side. Thereafter, the substrate or device is illuminated with electromagnetic radiation at an intensity and for a time period sufficient to cause the impurities to diffuse to the back side and alloy with a metal there present to form a contact and capture the impurities. The impurity gettering process also can function to simultaneously passivate defects within the substrate or device, with the defects likewise diffusing to the back side for simultaneous passivation. Simultaneously, substantially all hydrogen-induced damage on the back side of the substrate or device is likewise annihilated. Also taught is an alternate process comprising thermal treatment after hydrogenation of the substrate or device at a temperature of from about 500.degree. C. to about 700.degree. C. for a time period sufficient to cause the impurities to diffuse to the damaged back side thereof for subsequent capture by an alloying metal.

  6. Foldtrack in C-110 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    in C-110 Foldtrack in C-110 Addthis Description Foldtrack in C-110

  7. Dynamical symmetries in nuclear structure

    SciTech Connect (OSTI)

    Casten, R.F.

    1986-01-01

    In recent years the concept of dynamical symmetries in nuclei has witnessed a renaissance of interest and activity. Much of this work has been developed in the context of the Interacting Boson Approximation (or IBA) model. The appearance and properties of dynamical symmetries in nuclei will be reviewed, with emphasis on their characteristic signatures and on the role of the proton-neutron interaction in their formation, systematics and evolution. 36 refs., 20 figs.

  8. Oil shale research in China

    SciTech Connect (OSTI)

    Jianqiu, W.; Jialin, Q. (Beijing Graduate School, Petroleum Univ., Beijing (CN))

    1989-01-01

    There have been continued efforts and new emergence in oil shale research in Chine since 1980. In this paper, the studies carried out in universities, academic, research and industrial laboratories in recent years are summarized. The research areas cover the chemical structure of kerogen; thermal behavior of oil shale; drying, pyrolysis and combustion of oil shale; shale oil upgrading; chemical utilization of oil shale; retorting waste water treatment and economic assessment.

  9. PORTSMOUTH 2015 YEAR IN REVIEW

    Energy Savers [EERE]

    PORTSMOUTH 2015 YEAR IN REVIEW At the Portsmouth site this year, it was critical to have alignment among regulatory decisions and agreements, deactivation, shipping, and preliminary work on the on-site waste disposal facility. In 2015, we made significant progress in all of those areas. Our workforce performed admirably in 2015 and we look forward to continuing our momentum in 2016." - Dr. Vincent Adams, Portsmouth Site Director, DOE Portsmouth/Paducah Project Office KEY ACCOMPLISHMENTS 

  10. Frontiers in Science Lecture Series

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Video Resources » Frontiers in Science Lecture Series Frontiers in Science Lecture Series The Laboratory Fellows are appointed by the Laboratory Director in recognition of sustained outstanding contributions and exceptional promise for continued professional achievement. The Frontiers in Science series shares the Laboratory's cutting-edge research with the surrounding community. Contact Communications Office (505)665-9196 or (505)667-7000 Frontiers in Science Lecture Series Presented by the Los

  11. Phase coherent transport in hollow InAs nanowires

    SciTech Connect (OSTI)

    Wenz, T.; Rosien, M.; Haas, F.; Rieger, T.; Lepsa, M. I.; Lüth, H.; Grützmacher, D.; Schäpers, Th.; Demarina, N.

    2014-09-15

    Hollow InAs nanowires are produced from GaAs/InAs core/shell nanowires by wet chemical etching of the GaAs core. At room temperature, the resistivity of several nanowires is measured before and after removal of the GaAs core. The observed change in resistivity is explained by simulating the electronic states in both structures. At cryogenic temperatures, quantum transport in hollow InAs nanowires is studied. Flux periodic conductance oscillations are observed when the magnetic field is oriented parallel to the nanowire axis.

  12. Oil and gas developments in North Africa in 1984

    SciTech Connect (OSTI)

    Michel, R.Ch.

    1985-10-01

    Petroleum rights in the 6 North African countries (Algeria, Egypt, Libya, Morocco, Sudan, and Tunisia) covered in this paper were 1,906,065 km/sup 2/ at the end of 1984, an increase of 4.6% from the 1,821,966 km/sup 2/ in force at the end of 1983. This increase is due to large awards in the Sudan despite significant relinquishments elsewhere. Seismic surveys conducted during 1984 decreased to about 510.5 crew-months onshore and 29.5 crew-months offshore. However, exploration in and off Egypt was higher compared to 1983. Exploratory drilling was lower, with only 125 wells drilled compared to 179 tests completed in 1983. The main decrease was in Egypt and Sudan, but drilling in Libya resulted in 20 more completions. A significant oil discovery was made in the offshore part of the Sirte basin, off southwest Cyrenaica. The success rate in North Africa ranged from 19% to 50% (Libya). Development drilling increased during 1984, as higher activity appears to have taken place in 3 countries. Oil production, with an estimated daily rate of 2,952,570 bbl, was up 2.8% from 1983 (2,871,460 BOPD). In Egypt, 7 fields located in the Gulf of Suez area went on stream during the year. Political unrest, which prevailed in southern Sudan during most of 1984, will likely delay the start-up of production in several fields. No statistics are available on gas production in North African countries.

  13. Oil and gas developments in North Africa in 1984

    SciTech Connect (OSTI)

    Michel, R.C.

    1985-10-01

    Petroleum rights in the 6 North African countries (Algeria, Egypt, Libya, Morocco, Sudan, and Tunisia) covered in this paper were 1,906,065 km/sup 2/ at the end of 1984. An increase of 4.6% from the 1,821,966 km/sup 2/ in force at the end of 1983. This increase is due to large awards in the Sudan despite significant relinquishments elsewhere. Seismic surveys conducted during 1984 decreased to about 510.5 crew-months onshore and 29.5 crew-months offshore. However, exploration in and off Egypt was higher compared to 1983. Exploratory drilling was lower, with only 125 wells drilled compared to 179 tests completed in 1983. The main decrease was in Egypt and Sudan, but drilling in Libya resulted in 20 more completions. A significant oil discovery was made in the offshore part of the Sirte basin, off southwest Cyrenaica. The success rate in North America ranged from 19% to 50% (Libya). Development drilling increased during 1984, as higher activity appears to have taken place in 3 countries. Oil production, with an estimated daily rate of 2,952,570 bbl, was 2.8% from 1983 (2,871,460 BOPD). In Egypt, 7 fields located in the Gulf of Suez area went on stream during the year. Political unrest, which prevailed in southern Sudan during most of 1984, will likely delay the start-up of production in several fields. No statistics are available on gas production in North African countries. 9 figures, 27 tables.

  14. Band anticrossing in dilute nitrides

    SciTech Connect (OSTI)

    Shan, W.; Yu, K.M.; Walukiewicz, W.; Wu, J.; Ager III, J.W.; Haller, E.E.

    2003-12-23

    Alloying III-V compounds with small amounts of nitrogen leads to dramatic reduction of the fundamental band-gap energy in the resulting dilute nitride alloys. The effect originates from an anti-crossing interaction between the extended conduction-band states and localized N states. The interaction splits the conduction band into two nonparabolic subbands. The downward shift of the lower conduction subband edge is responsible for the N-induced reduction of the fundamental band-gap energy. The changes in the conduction band structure result in significant increase in electron effective mass and decrease in the electron mobility, and lead to a large enhance of the maximum doping level in GaInNAs doped with group VI donors. In addition, a striking asymmetry in the electrical activation of group IV and group VI donors can be attributed to mutual passivation process through formation of the nearest neighbor group-IV donor nitrogen pairs.

  15. Minnesota Natural Gas in Underground Storage - Change in Working...

    U.S. Energy Information Administration (EIA) Indexed Site

    Percent) Minnesota Natural Gas in Underground Storage - Change in Working Gas from Same Month Previous Year (Percent) Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 1991 -9.2 ...

  16. Minnesota Natural Gas in Underground Storage - Change in Working...

    U.S. Energy Information Administration (EIA) Indexed Site

    Million Cubic Feet) Minnesota Natural Gas in Underground Storage - Change in Working Gas from Same Month Previous Year (Million Cubic Feet) Year Jan Feb Mar Apr May Jun Jul Aug Sep ...

  17. Plug-in Electric Vehicles Charge Forward in Oregon | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... EV Everywhere Charges Up the Workplace Project Overview Positive Impact More plug-in hybrid and all-electric vehicles in Oregon. Oregon is planning for the large-scale deployment ...

  18. In Texas, Staples Recognized for Leadership in Energy Efficiency...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Staples -- one of the world's largest e-commerce companies - has committed to reducing energy intensity by 25 percent in more than 1,700 of its buildings in the next ten years. To ...

  19. California Natural Gas in Underground Storage - Change in Working...

    Annual Energy Outlook [U.S. Energy Information Administration (EIA)]

    Percent) California Natural Gas in Underground Storage - Change in Working Gas from Same Month Previous Year (Percent) Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 1991 5.1 ...

  20. California Natural Gas in Underground Storage - Change in Working...

    U.S. Energy Information Administration (EIA) Indexed Site

    Million Cubic Feet) California Natural Gas in Underground Storage - Change in Working Gas from Same Month Previous Year (Million Cubic Feet) Year Jan Feb Mar Apr May Jun Jul Aug ...

  1. NNSA to Participate in Aerial Radiation Training Exercise in...

    National Nuclear Security Administration (NNSA)

    in the midst of a potential radiological emergency, and test the knowledge and expertise of these agencies to ensure to a unified response in case of an actual emergency. ...

  2. Largest Cellulosic Ethanol Plant in the World Opened in October

    Broader source: Energy.gov [DOE]

    TheDuPont cellulosic ethanol facility openedin Nevada, Iowa, last month and isthe largest cellulosic ethanol plant in the world. The U.S. Department of Energy (DOE) Bioenergy Technologies Office...

  3. Neutron inelastic scattering in natural Pb as a background in...

    Office of Scientific and Technical Information (OSTI)

    Close Cite: Bibtex Format Close 0 pages in this document matching the terms "" Search For Terms: Enter terms in the toolbar above to search the full text of this document for ...

  4. Recent content in Linked Open Data Workshop in Washington, D...

    Open Energy Info (EERE)

    Recent content in Linked Open Data Workshop in Washington, D.C. Home Name Post date sort icon Type Detailed Planning Kicks Off Jweers 27 Sep 2012 - 06:53 Blog entry Notes from the...

  5. In situ quantification of genomic instability in breast cancer progression

    SciTech Connect (OSTI)

    Ortiz de Solorzano, Carlos; Chin, Koei; Gray, Joe W.; Lockett, Stephen J.

    2003-05-15

    Genomic instability is a hallmark of breast and other solid cancers. Presumably caused by critical telomere reduction, GI is responsible for providing the genetic diversity required in the multi-step progression of the disease. We have used multicolor fluorescence in situ hybridization and 3D image analysis to quantify genomic instability cell-by-cell in thick, intact tissue sections of normal breast epithelium, preneoplastic lesions (usual ductal hyperplasia), ductal carcinona is situ or invasive carcinoma of the breast. Our in situ-cell by cell-analysis of genomic instability shows an important increase of genomic instability in the transition from hyperplasia to in situ carcinoma, followed by a reduction of instability in invasive carcinoma. This pattern suggests that the transition from hyperplasia to in situ carcinoma corresponds to telomere crisis and invasive carcinoma is a consequence of telomerase reactivation afertelomere crisis.

  6. Aridity changes in the Tibetan Plateau in a warming climate

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gao, Yanhong; Li, Xia; Leung, Lai-Yung R.; Chen, Deliang; Xu, Jianwei

    2015-03-10

    Desertification in the Tibetan Plateau (TP) has drawn increasing attention in the recent decades. It has been postulated as a consequence of climate aridity due to the observed warming. This study quantifies the aridity changes in the TP and attributes the changes to different climatic factors. Using the ratio of P/PET (precipitation to potential evapotranspiration) as an aridity index to indicate changes in dryness and wetness in a given area, P/PET was calculated using observed records at 83 stations in the TP, with PET calculated using the Penman–Monteith (PM) algorithm. Spatial and temporal changes of P/PET in 1979-2011 are analyzed.more » Results show that stations located in the arid and semi-arid northwestern TP are becoming significantly wetter and stations in the semi-humid southeastern TP are becoming drier, though not significantly, in the recent three decades. The aridity change patterns are significantly correlated with precipitation, sunshine duration and diurnal temperature range changes at confidence level of 99.9% from two-tail t-test. Temporal correlations also confirm the significant correlation between aridity changes with the three variables, with precipitation being the most dominant driver of P/PET changes at interannual time scale. PET changes are insignificant but negatively correlated with P/PET in the cold season. In the warm season, however, correlation between PET changes and P/PET changes are significant at confidence level of 99.9% when the cryosphere melts near the surface. Significant correlation between wind speed changes and aridity changes occurs in limited locations and months. Consistency in the climatology pattern and linear trends in surface air temperature and precipitation calculated using station data, gridded data, and nearest grid-to-stations for the TP average and across sub-basins indicate the robustness of the trends despite the large spatial heterogeneity in the TP that challenge climate monitoring.« less

  7. Earthquake triggering discussed in three Frontiers in Science lectures

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Frontiers in Science lectures Earthquake triggering discussed in three Frontiers in Science lectures Earthquakes and their possible causes is the topic of the next series of Frontiers in Science lectures by Paul Johnson. November 6, 2014 Paul Johnson Paul Johnson Contact Steve Sandoval Communications Office (505) 665-9206 Email "What is it that makes the Earth move under our feet?" Johnson asks. "How is it that earthquakes can cause other earthquakes? Can human activities also

  8. Aridity changes in the Tibetan Plateau in a warming climate

    SciTech Connect (OSTI)

    Gao, Yanhong; Li, Xia; Leung, Lai-Yung R.; Chen, Deliang; Xu, Jianwei

    2015-03-10

    Desertification in the Tibetan Plateau (TP) has drawn increasing attention in the recent decades. It has been postulated as a consequence of climate aridity due to the observed warming. This study quantifies the aridity changes in the TP and attributes the changes to different climatic factors. Using the ratio of P/PET (precipitation to potential evapotranspiration) as an aridity index to indicate changes in dryness and wetness in a given area, P/PET was calculated using observed records at 83 stations in the TP, with PET calculated using the Penman–Monteith (PM) algorithm. Spatial and temporal changes of P/PET in 1979-2011 are analyzed. Results show that stations located in the arid and semi-arid northwestern TP are becoming significantly wetter and stations in the semi-humid southeastern TP are becoming drier, though not significantly, in the recent three decades. The aridity change patterns are significantly correlated with precipitation, sunshine duration and diurnal temperature range changes at confidence level of 99.9% from two-tail t-test. Temporal correlations also confirm the significant correlation between aridity changes with the three variables, with precipitation being the most dominant driver of P/PET changes at interannual time scale. PET changes are insignificant but negatively correlated with P/PET in the cold season. In the warm season, however, correlation between PET changes and P/PET changes are significant at confidence level of 99.9% when the cryosphere melts near the surface. Significant correlation between wind speed changes and aridity changes occurs in limited locations and months. Consistency in the climatology pattern and linear trends in surface air temperature and precipitation calculated using station data, gridded data, and nearest grid-to-stations for the TP average and across sub-basins indicate the robustness of the trends despite the large spatial heterogeneity in the TP that challenge climate monitoring.

  9. Oil and gas developments in Middle East in 1982

    SciTech Connect (OSTI)

    Hemer, D.O.; Hatch, G.C.

    1983-10-01

    Petroleum production in Middle East countries during 1982 totaled 4,499,464,000 bbl (an average rate of 12,162,915 BOPD), down 21.5% from 1981. Increases were in Iraq, Iran, and Oman. Significant decreases occurred in Kuwait, Divided Neutral Zone, Saudi Arabia, Qatar, and Abu Dhabi. New discoveries were reported in Oman, Syria, Abu Dhabi, Dubai, Iran, and Saudi Arabia.

  10. NNSA to Participate in Aerial Radiation Training Exercise in Philadelphia,

    National Nuclear Security Administration (NNSA)

    Pennsylvania | National Nuclear Security Administration to Participate in Aerial Radiation Training Exercise in Philadelphia, Pennsylvania March 17, 2016 (WASHINGTON, D.C.) - On March 21 through March 24, the Department of Energy's National Nuclear Security Administration (NNSA) will participate in a federal and state/local training exercise in Philadelphia that will also include the Philadelphia Police Department and the Departments of Defense, Justice/Federal Bureau of Investigation

  11. CRADA with PACCAR Experimental Investigation in Coolant Boiling in a

    Broader source: Energy.gov (indexed) [DOE]

    Half-Heated Circular Tube | Department of Energy 1 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation PDF icon vss057_yu_2011_p.pdf More Documents & Publications PACCAR CRADA: Experimental Investigation in Coolant Boiling in a Half-Heated Circular Tube Efficient Cooling in Engines with Nucleated Boiling Cooling Boiling in Head Region - PACCAR Integrated Underhood Thermal and External Aerodynamics- Cummins

  12. Simple intrinsic defects in InAs : numerical predictions.

    SciTech Connect (OSTI)

    Schultz, Peter Andrew

    2013-03-01

    This Report presents numerical tables summarizing properties of intrinsic defects in indium arsenide, InAs, as computed by density functional theory using semi-local density functionals, intended for use as reference tables for a defect physics package in device models.

  13. Electricity Prices in Transition (released in AEO2007)

    Reports and Publications (EIA)

    2007-01-01

    The push by some states to restructure electricity markets progressed rapidly throughout the late 1990s. Although the energy crisis in California during 2000 and 2001 slowed the momentum, 19 states and the District of Columbia currently have some form of restructuring in place. In addition, Washington State, which has not restructured its electricity market, allows its largest industrial customers to choose their suppliers.

  14. Health impact assessment in Korea

    SciTech Connect (OSTI)

    Kang, Eunjeong; Lee, Youngsoo; Harris, Patrick; Koh, Kwangwook; Kim, Keonyeop

    2011-07-15

    Recently, Health Impact Assessment has gained great attention in Korea. First, the Ministry of Environment introduced HIA within existing Environment Impact Assessment. Second, the Korea Institute for Health and Social Affairs began an HIA program in 2008 in alliance with Healthy Cities. In this short report, these two different efforts are introduced and their opportunities and challenges discussed. We believe these two approaches complement each other and both need to be strengthened. We also believe that both can contribute to the development of health in policy and project development and ultimately to improvements in the Korean population's health.

  15. Electroelastic fields in artificially created vortex cores in epitaxial

    Office of Scientific and Technical Information (OSTI)

    BiFeO3 thin films (Journal Article) | SciTech Connect Electroelastic fields in artificially created vortex cores in epitaxial BiFeO3 thin films Citation Details In-Document Search This content will become publicly available on August 4, 2016 Title: Electroelastic fields in artificially created vortex cores in epitaxial BiFeO3 thin films Authors: Winchester, B. [1] ; Balke, N. [2] ; Cheng, X. X. [1] ; Morozovska, A. N. [3] ; Kalinin, S. [2] Search SciTech Connect for author "Kalinin,

  16. Recent developments in graphite. [Use in HTGR and aerospace

    SciTech Connect (OSTI)

    Cunningham, J.E.

    1983-01-01

    Overall, the HTGR graphite situation is in excellent shape. In both of the critical requirements, fuel blocks and support structures, adequate graphites are at hand and improved grades are sufficiently far along in truncation. In the aerospace field, GraphNOL N3M permits vehicle performance with confidence in trajectories unobtainable with any other existing material. For fusion energy applications, no other graphite can simultaneously withstand both extreme thermal shock and neutron damage. Hence, the material promises to create new markets as well as to offer a better candidate material for existing applications.

  17. Oil and gas developments in Middle East in 1986

    SciTech Connect (OSTI)

    Hemer, D.O.; Gohrbandt, K.H.A.

    1987-10-01

    Petroleum production in Middle East countries during 1986 totaled 4,493,973,000 bbl (an average rate of 12,312,254 BOPD), up 22.3% from the revised 1985 total of 3,673,729,000 bbl. Iraq, Kuwait, Saudi Arabia, Abu Dhabi, and Oman had significant increased; Iran was the only Middle East country with a significant decrease. New fields went on production in Oman and Yemen Arab Republic, and significant discoveries were reported in Iraq, Yemen Arab Republic, Oman, and Syria. However, exploration was generally down in most countries. Exploration and production operations continued to be affected by war in Iraq and Iran. 8 figures, 7 tables.

  18. Distributed Generation in Buildings (released in AEO2005)

    Reports and Publications (EIA)

    2008-01-01

    Currently, distributed generation provides a very small share of residential and commercial electricity requirements in the United States. The Annual Energy Outlook 2005 reference case projects a significant increase in electricity generation in the buildings sector, but distributed generation is expected to remain a small contributor to the sectors energy needs. Although the advent of higher energy prices or more rapid improvement in technology could increase the use of distributed generation relative to the reference case projection, the vast majority of electricity used in buildings is projected to continue to be purchased from the grid.

  19. Role of Pentahedrally Coordinated Titanium in Titanium Silicalite-1 in

    Office of Scientific and Technical Information (OSTI)

    Propene Epoxidation (Journal Article) | SciTech Connect Role of Pentahedrally Coordinated Titanium in Titanium Silicalite-1 in Propene Epoxidation Citation Details In-Document Search Title: Role of Pentahedrally Coordinated Titanium in Titanium Silicalite-1 in Propene Epoxidation Authors: Zuo, Y ; Liu, M ; Hong, L ; Guo, S ; Song, C ; Chen, Y ; Zhu, P ; Jaye, C ; Fischer, D Publication Date: 2015-02-10 OSTI Identifier: 1229331 Report Number(s): BNL--111406-2015-JA Journal ID: ISSN 2046-2069

  20. Tritium handling in vacuum systems

    SciTech Connect (OSTI)

    Gill, J.T. [Monsanto Research Corp., Miamisburg, OH (United States). Mound Facility; Coffin, D.O. [Los Alamos National Lab., NM (United States)

    1986-10-01

    This report provides a course in Tritium handling in vacuum systems. Topics presented are: Properties of Tritium; Tritium compatibility of materials; Tritium-compatible vacuum equipment; and Tritium waste treatment.

  1. Where Do OLEDs Fit In?

    Energy Savers [EERE]

    Where Do OLEDs Fit In? DOE SSL Workshop Portland, OR Giana M. Phelan Where do OLEDs fit in? A solid-state lighting solution that complements LED With the SSL advantages...

  2. Feed-in Tariff Resources

    Broader source: Energy.gov [DOE]

    A feed-in tariff (FIT) is an energy-supply policy focused on supporting the development of new renewable power generation. In the United States, FIT policies provide a guarantee to eligible...

  3. Energy Conservation in State Buildings

    Broader source: Energy.gov [DOE]

    In 1992 the state enacted legislation requiring the Maryland Energy Administration (MEA) and the DGS to set energy performance standards that would reduce energy consumption in state buildings by...

  4. Acquisition Letters Remaining In Effect

    Broader source: Energy.gov [DOE]

    Acquisition Letter (AL) 2010-07 has been issued. It lists ALs currently in effect and the discontinued ALs along with the reason why the AL is no longer in effect.

  5. Acquisition Letters Remaining In Effect

    Broader source: Energy.gov [DOE]

    Acquisition Letter (AL) 2012-01 has been issued. It lists ALs currently in effect and the discontinued ALs, along with the reason why the AL is no longer in effect.

  6. Fire in a contaminated area

    SciTech Connect (OSTI)

    Ryan, G.W., Westinghouse Hanford

    1996-08-28

    This document supports the development and presentation of the following accident scenario in the TWRS Final Safety Analysis Report: Fire in Contaminated Area. The calculations needed to quantify the risk associated with this accident scenario are included within.

  7. Women in Solar Networking Breakfast

    Broader source: Energy.gov [DOE]

    Women In Solar Breakfast, presented by the SunShot Initiative. The women of the SunShot Initiative invite you to join us for a unique opportunity for professional women in the solar community to...

  8. NIPSCO- Feed-In Tariff

    Broader source: Energy.gov [DOE]

    NIPSCO is offering a feed-in tariff program for customers who generate electricity from solar, wind, biomass, or new hydroelectric facilities. All NIPSCO electric customers in good standing are...

  9. Quantum fluctuations in beam dynamics.

    SciTech Connect (OSTI)

    Kim, K.-J.

    1998-06-04

    Quantum effects could become important for particle and photon beams used in high-luminosity and high brightness applications in the current and next generation accelerators and radiation sources. This paper is a review of some of these effects.

  10. NIPSCO- Feed-In Tariff

    Broader source: Energy.gov [DOE]

    NIPSCO is offering a feed-in tariff program for customers who generate electricity from solar, wind, or biomass. All NIPSCO electric customers in good standing are eligible for the program....

  11. Energy Efficiency in State Facilities

    Broader source: Energy.gov [DOE]

    In April 2005 Iowa governor Tom Vilsack issued Executive Order No. 41, directing state agencies to reduce electricity and natural gas use in buildings by an average of 15% by 2010, relative to th...

  12. Imaging atoms in 3-D

    ScienceCinema (OSTI)

    Ercius, Peter

    2014-06-27

    Berkeley Lab's Peter Ercius discusses "Imaging atoms in 3-D" in this Oct. 28, 2013 talk, which is part of a Science at the Theater event entitled Eight Big Ideas

  13. Surprising Quasiparticle Interactions in Graphene

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    that suggest new kinds of devices. Particle Physics in Your Pencil Quantum electrodynamics, or QED, is the theory of many-body interactions first invented in the 1950s by...

  14. Advancing Residential Retrofits in Atlanta

    SciTech Connect (OSTI)

    Jackson, Roderick K; Kim, Eyu-Jin; Roberts, Sydney; Stephenson, Robert

    2012-07-01

    This report will summarize the home energy improvements performed in the Atlanta, GA area. In total, nine homes were retrofitted with eight of the homes having predicted source energy savings of approximately 30% or greater based on simulated energy consumption.

  15. Radiation Levels in Real Time?

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Levels in Real Time? There's an App for That Gamma radiation levels in the southern Nevada area will soon be accessible around the world at the touch of a finger. Makers of the ...

  16. Brookhaven Women in Science Lecture

    ScienceCinema (OSTI)

    Johanna Levelt Sengers

    2010-09-01

    Sponsored by Brookhaven Women in Science (BWIS), Johanna Levelt Sengers, Scientist Emeritus at the National Institute of Standards & Technology (NIST), presents a talk titled "The World's Science Academies Address the Under-Representation of Women in Science and Technology."

  17. Geranylgeranylacetone inhibits ovarian cancer progression in vitro and in vivo

    SciTech Connect (OSTI)

    Hashimoto, Kae; Morishige, Ken-ichirou . E-mail: mken@gyne.med.osaka-u.ac.jp; Sawada, Kenjiro; Ogata, Seiji; Tahara, Masahiro; Shimizu, Shoko; Sakata, Masahiro; Tasaka, Keiichi; Kimura, Tadashi

    2007-04-27

    Geranylgeranylacetone (GGA), an isoprenoid compound, is an anti-ulcer drug developed in Japan. In our previous study, GGA was shown to inhibit ovarian cancer invasion by attenuating Rho activation [K. Hashimoto, K. Morishige, K. Sawada, M. Tahara, S. Shimizu, M. Sakata, K. Tasaka, Y. Murata, Geranylgeranylacetone inhibits lysophosphatidic acid-induced invasion of human ovarian carcinoma cells in vitro. Cancer 103 (2005) 1529-1536.]. In the present study, GGA treatment inhibited ovarian cancer progression in vitro and suppressed the tumor growth and ascites in the in vivo ovarian cancer model. In vitro analysis, treatment of cancer cells by GGA resulted in the inhibition of cancer cell proliferation, the inactivation of Ras, and the suppression of tyrosine phosphorylation of mitogen-activated protein kinase (MAPK). In conclusion, this is the first report that GGA inhibited ovarian cancer progression and the anti-tumor effect by GGA is, at least in part, derived not only from the suppression of Rho activation but also Ras-MAPK activation.

  18. Voluntary agreements in the industrial sector in China

    SciTech Connect (OSTI)

    Price, Lynn; Worrell, Ernst; Sinton, Jonathan

    2003-03-31

    China faces a significant challenge in the years ahead to continue to provide essential materials and products for a rapidly-growing economy while addressing pressing environmental concerns. China's industrial sector is heavily dependent on the country's abundant, yet polluting, coal resources. While tremendous energy conservation and environmental protection achievements were realized in the industrial sector in the past, there remains a great gulf between the China's level of energy efficiency and that of the advanced countries of the world. Internationally, significant energy efficiency improvement in the industrial sector has been realized in a number of countries using an innovative policy mechanism called Voluntary Agreements. This paper describes international experience with Voluntary Agreements in the industrial sector as well as the development of a pilot program to test the use of such agreements with two steel mills in Shandong Province, China.

  19. Lead and cadmium concentrations in livestock bred in Campania, Italy

    SciTech Connect (OSTI)

    Amodio-Cocchieri, R.; Fiore, P.

    1987-09-01

    Among the various aspects of environmental pollution, special attention must be directed to heavy metals, which show a remarkable tendency to accumulate in tissues and organs of animals and humans. Particularly, lead and cadmium are of great concern when one considers that the variety of their uses has increased their level in the environment and that they have been identified as the causes of several clinical problems. Since heavy metals may be used as indicators of industrial contamination, the Italian Ministry of Health started a research program concerning the lead and cadmium levels in meat, cow's milk and eggs produce by Italian livestock and in well water, and in local and industrial feeds tuffs employed in their breeding. This is the object of the present study carried out in the Campania province.

  20. Chiral asymmetry in relativistic matter in a magnetic field

    SciTech Connect (OSTI)

    Shovkovy, I. A.

    2009-12-17

    We show that the normal phase of dense relativistic matter in a magnetic field is characterized by a nonzero relative shift of the longitudinal momenta in the dispersion relations of the left-handed and right-handed fermions. The presence of such a shift in the ground state does not break any symmetries of the action. To leading order, the corresponding parameter, dubbed the chiral shift, is linear in the coupling constant. Because of the chiral shift, a dynamical contribution to the axial current is induced. The induced axial current and the shift of the Fermi surfaces of the opposite chirality fermions are expected to play an important role in transport and emission properties of matter in various types of compact stars as well as in heavy ion collisions.

  1. Oil and gas developments in North Africa in 1985

    SciTech Connect (OSTI)

    Michel, R.C.

    1986-10-01

    Petroleum rights in the 6 North African countries (Algeria, Egypt, Libya, Morocco, Sudan, and Tunisia) covered in this paper were 1,839,817 km/sup 2/ at the end of 1985, a decrease of 3% from the 1,896,446 km/sup 2/ held at the end of 1984. This decrease mainly is due to significant relinquishments made in Algeria, Egypt, and Tunisia. Morocco, however, had an increase of 18,087 km/sup 2/. Oil discoveries were reported in Algeria (possibly 5), Libya (at least 2), and Egypt (16). Only 1 gas find was made (in Morocco). According to sparse information, development drilling may have decreased markedly during 1985. Oil and condensate production increased by 3.1% to approximately 3,054,000 b/d compared to about 2,963,400 b/d in 1984. No statistics are currently available on gas production in North Africa. 8 figures, 27 tables.

  2. Boron diffusion in silicon devices

    SciTech Connect (OSTI)

    Rohatgi, Ajeet; Kim, Dong Seop; Nakayashiki, Kenta; Rounsaville, Brian

    2010-09-07

    Disclosed are various embodiments that include a process, an arrangement, and an apparatus for boron diffusion in a wafer. In one representative embodiment, a process is provided in which a boric oxide solution is applied to a surface of the wafer. Thereafter, the wafer is subjected to a fast heat ramp-up associated with a first heating cycle that results in a release of an amount of boron for diffusion into the wafer.

  3. Thrusts in High Performance Computing

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in HPC 1 Thrusts in High Performance Computing Science at Scale Petaflops to Exaflops Science through Volume Thousands to Millions of Simulations Science in Data Petabytes to Exabytes of Data 2 Science at Scale: Simulations Aid in Understanding Climate Impacts 3 Antarctic ice speed (left): AMR enables sub-1 km resolution (black, above) (Using NERSC's Hopper) BISICLES Pine Island Glacier simulation - mesh resolution crucial for grounding line behavior. Enhanced POP ocean model solution for

  4. HADRONIC FLUCTUATIONS IN THE QGP.

    SciTech Connect (OSTI)

    EJIRI, S.; KARSCH, F.; REDLICH, K.

    2005-08-04

    We analyze fluctuations of quark number and electric charge, in 2-flavour QCD at finite temperature and vanishing net baryon number density. In the hadronic phase we find that an enhancement of charge fluctuations arises from contributions of doubly charged hadrons to the thermodynamics. The rapid suppression of fluctuations seen in the high temperature phase suggests that in the QGP quark number and electric charge are predominantly carried by quasi-particles with the quantum numbers of quarks.

  5. Hunting for meteorites in Antarctica

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hunting for meteorites in Antarctica Hunting for meteorites in Antarctica Nina Lanza was selected as one of eight members for the 2015-2016 field campaign of the Antarctica Search for Meteorites (ANSMET) program. November 13, 2015 Lanza at the summit of Hvannadalsnukur, the highest mountain in Iceland, practicing glacier travel techniques similar to those needed for Antarctic fieldwork. Lanza at the summit of Hvannadalsnukur, the highest mountain in Iceland, practicing glacier travel techniques

  6. Deterministic methods in radiation transport

    SciTech Connect (OSTI)

    Rice, A.F.; Roussin, R.W.

    1992-06-01

    The Seminar on Deterministic Methods in Radiation Transport was held February 4--5, 1992, in Oak Ridge, Tennessee. Eleven presentations were made and the full papers are published in this report, along with three that were submitted but not given orally. These papers represent a good overview of the state of the art in the deterministic solution of radiation transport problems for a variety of applications of current interest to the Radiation Shielding Information Center user community.

  7. Saving Energy in Multifamily Buildings

    Broader source: Energy.gov [DOE]

    This presentation is for the Building Technologies program webinar titled Saving Energy in Multifamily Buildings delivered on July 25, 2011.

  8. Stratification in hot water tanks

    SciTech Connect (OSTI)

    Balcomb, J.D.

    1982-04-01

    Stratification in a domestic hot water tank, used to increase system performance by enabling the solar collectors to operate under marginal conditions, is discussed. Data taken in a 120 gallon tank indicate that stratification can be achieved without any special baffling in the tank. (MJF)

  9. Pantothenic acid biosynthesis in zymomonas

    DOE Patents [OSTI]

    Tao, Luan; Tomb, Jean-Francois; Viitanen, Paul V.

    2014-07-01

    Zymomonas is unable to synthesize pantothenic acid and requires this essential vitamin in growth medium. Zymomonas strains transformed with an operon for expression of 2-dehydropantoate reductase and aspartate 1-decarboxylase were able to grow in medium lacking pantothenic acid. These strains may be used for ethanol production without pantothenic acid supplementation in seed culture and fermentation media.

  10. In situ biofilm coupon device

    DOE Patents [OSTI]

    Peyton, Brent M.; Truex, Michael J.

    1997-01-01

    An apparatus for characterization of in-situ microbial biofilm populations in subsurface groundwater. The device permits biofilm-forming microorganisms to adhere to packing material while emplaced in a groundwater strata, so that the packing material can be later analyzed for quantity and type of microorganisms, growth rate, and nutrient requirements.

  11. FEMP Year in Review 2009

    SciTech Connect (OSTI)

    2009-12-01

    In 2009, the Federal Energy Management Program (FEMP)undertook an ambitious reorganization of its program structure to be more responsive to the needs of its Federal agency customers. In this Year in Review 2009, you will learn more about FEMP achievements under its new program areas.

  12. Tropospheric ozone in east Asia

    SciTech Connect (OSTI)

    Phadnis, M.J.

    1996-12-31

    An analysis of the observed data for the tropospheric ozone at mid latitudes in east Asia is done. There are three ways by which the tropospheric ozone is calculated, namely: (1) Ozonesonde measurements, (2) Fishman`s method of Residual Ozone and (3) TOMS measurements - an indirect method of calculating tropospheric ozone. In addition the surface ozone values at the network sites in Japan is also considered. The analysis of data is carried out for a period of twelve years from 1979 to 1991. In general it is observed that the tropospheric ozone is more in summer than winter, obviously because of the larger tropopause height in summer. On an average for the period of the analysis, the ozone values are at a high of about 60 DU (dobson units). While in winter the values go down to around 30 DU. Also a time series analysis shows an increasing trend in the values over the years. The ozonesonde values are correlated more to the TOMS tropospheric ozone values. For the stations analyzed in Japan, the TOMS tropospheric ozone values are generally greater than the ozonesonde values. The analysis of the average monthly surface ozone in Japan shows highs in spring and lows in summer. This can be attributed to movement of pollutant laden fronts towards Japan during spring. The highs for surface ozone are about 50 DU while the lows are around 20 DU.

  13. Risk perception in developing countries

    SciTech Connect (OSTI)

    Wilbanks, T.J.; Rayner, S.F.

    1985-02-15

    The paper briefly reviews: (1) what risk perception means to most people in developing countries; (2) some of the modern-technology-related risks to which people in these countries are exposed; and (3) some research evidence about risk perception that gives hints about how such perceptions will evolve in developing countries. (ACR)

  14. In situ biofilm coupon device

    DOE Patents [OSTI]

    Peyton, B.M.; Truex, M.J.

    1997-06-24

    An apparatus is disclosed for characterization of in-situ microbial biofilm populations in subsurface groundwater. The device permits biofilm-forming microorganisms to adhere to packing material while emplaced in a groundwater strata, so that the packing material can be later analyzed for quantity and type of microorganisms, growth rate, and nutrient requirements. 3 figs.

  15. Transplacental arsenic carcinogenesis in mice

    SciTech Connect (OSTI)

    Waalkes, Michael P. Liu, Jie; Diwan, Bhalchandra A.

    2007-08-01

    Our work has focused on the carcinogenic effects of in utero arsenic exposure in mice. Our data show that a short period of maternal exposure to inorganic arsenic in the drinking water is an effective, multi-tissue carcinogen in the adult offspring. These studies have been reproduced in three temporally separate studies using two different mouse strains. In these studies pregnant mice were treated with drinking water containing sodium arsenite at up to 85 ppm arsenic from days 8 to 18 of gestation, and the offspring were observed for up to 2 years. The doses used in all these studies were well tolerated by both the dam and offspring. In C3H mice, two separate studies show male offspring exposed to arsenic in utero developed liver carcinoma and adrenal cortical adenoma in a dose-related fashion during adulthood. Prenatally exposed female C3H offspring show dose-related increases in ovarian tumors and lung carcinoma and in proliferative lesions (tumors plus preneoplastic hyperplasia) of the uterus and oviduct. In addition, prenatal arsenic plus postnatal exposure to the tumor promoter, 12-O-tetradecanoyl phorbol-13-acetate (TPA) in C3H mice produces excess lung tumors in both sexes and liver tumors in females. Male CD1 mice treated with arsenic in utero develop tumors of the liver and adrenal and renal hyperplasia while females develop tumors of urogenital system, ovary, uterus and adrenal and hyperplasia of the oviduct. Additional postnatal treatment with diethylstilbestrol or tamoxifen after prenatal arsenic in CD1 mice induces urinary bladder transitional cell proliferative lesions, including carcinoma and papilloma, and enhances the carcinogenic response in the liver of both sexes. Overall this model has provided convincing evidence that arsenic is a transplacental carcinogen in mice with the ability to target tissues of potential human relevance, such as the urinary bladder, lung and liver. Transplacental carcinogenesis clearly occurs with other agents in humans and investigating a potential transplacental component of the human carcinogenic response to arsenic should be a research priority.

  16. California energy flow in 1993

    SciTech Connect (OSTI)

    Borg, I.Y.; Briggs, C.K.

    1995-04-01

    Energy consumption in the state of California decreased about 3% in 1993 reflecting continuation of the recession that was manifest in a moribund construction industry and a high state unemployment that ran counter to national recovery trends. Residential/commercial use decreased slightly reflecting a mild winter in the populous southern portion of the state, a decrease that was offset to some extent by an increase in the state population. Industrial consumption of purchased energy declined substantially as did production of self-generated electricity for in-house use. Consumption in the transportation sector decreased slightly. The amount of power transmitted by the utilities was at 1992 levels; however a smaller proportion was produced by the utilities themselves. Generation of electricity by nonutilities, primarily cogenerators and small power producers, was the largest of any state in the US. The growth in the number of private power producers combined with increased amounts of electricity sold to the public utilities set the stage for the sweeping proposals before the California Public Utility Commission to permit direct sales from the nonutilities to retail customers. California production of both oil and natural gas declined; however, to meet demand only the imports of natural gas increased. A break in the decade-long drought during the 1992--1993 season resulted in a substantial increase in the amount of hydroelectricity generated during the year. Geothermal energy`s contribution increased substantially because of the development of new resources by small power producers. Decline in steam production continued at The Geysers, the state`s largest field, principally owned and managed by a public utility. Increases in windpower constituted 1--1/2% of the total electric supply--up slightly from 1992. Several solar photo voltaic demonstration plants were in operation, but their contribution remained small.

  17. California energy flow in 1991

    SciTech Connect (OSTI)

    Borg, I.Y.; Briggs, C.K.

    1993-04-01

    Energy consumption in California fell in 1991 for the first time in five years. The State`s economy was especially hard hit by a continuing national recession. The construction industry for the second year experienced a dramatic downturn. Energy use in the industrial sector showed a modest increase, but consumption in other end-use categories declined. The decrease in energy used in transportation can be traced to a substantial fall in the sales of both highway diesel fuels and vessel bunkering fuels at California ports, the latter reflecting a mid-year increase in taxes. Gasoline sales by contrast increased as did the number of miles traveled and the number of automobiles in the State. Production in California`s oil and gas fields was at 1990 levels thus arresting a steady decline in output. Due to enlarged steam flooding operations, production at several fields reached record levels. Also countering the decline in many of California fields was new production from the Port Arguello offshore field. California natural gas production, despite a modest 1991 increase, will not fill the use within the State. Petroleum comprised more than half of the State`s energy supply principally for transportation. Natural gas use showed a small increase. Oil products play virtually no role in electrical production. The largest single source of electricity to the State is imports from the Pacific Northwest and from coal-fired plants in the Southwest. Combined contributions to transmitted electricity from renewable and alternate sources declined as hydropower was constrained by a prolonged drought and as geothermal power from the largest and oldest field at The Geysers fell. Windpower grew slightly; however solar power remained at 1990 levels and made no substantial contribution to total power generation.

  18. Oil and gas development in Middle East in 1987

    SciTech Connect (OSTI)

    Hemer, D.O.; Gohrbandt, K.H.A.; Phillips, C.B.

    1988-10-01

    Petroleum production in Middle East countries during 1987 totaled an estimated 4,500,500,000 bbl (an average rate of 12,330,137 b/d), up slightly from the revised 1986 total of 4,478,972,000 bbl. Iran, Iraq, Syria, and Yemen Arab Republic had significant increases; Kuwait and Saudi Arabia had significant decreases. Production was established for the first time in People's Democratic Republic of Yemen. New fields went on production in Iraq, Oman, People's Democratic Republic of Yemen, and Syria, and significant oil discoveries were reported in Iraq, Oman, People's Democratic Republic of Yemen, Syria, and Yemen Arab Republic. The level of exploration increased in 1987 with new concessions awarded in some countries, drilling and seismic activities on the increase, new regions in mature areas explored for the first time, and significant reserve additions reported in new and old permits. The Iraq-Iran war still had a negative impact in some regions of the Middle East, particularly in and around the Gulf. 11 figs., 4 tabs.

  19. Retention of elemental mercury in fly ashes in different atmospheres

    SciTech Connect (OSTI)

    M.A. Lopez-Anton; M. Diaz-Somoano; M.R. Martinez-Tarazona

    2007-01-15

    Mercury is an extremely volatile element, which is emitted from coal combustion to the environment mostly in the vapor phase. To avoid the environmental problems that the toxic species of this element may cause, control technologies for the removal of mercury are necessary. Recent research has shown that certain fly ash materials have an affinity for mercury. Moreover, it has been observed that fly ashes may catalyze the oxidation of elemental mercury and facilitate its capture. However, the exact nature of Hg-fly ash interactions is still unknown, and mercury oxidation through fly ash needs to be investigated more thoroughly. In this work, the influence of a gas atmosphere on the retention of elemental mercury on fly ashes of different characteristics was evaluated. The retention capacity was estimated comparatively in inert and two gas atmospheres containing species present in coal gasification and coal combustion. Fly ashes produced in two pulverized coal combustion (PCC) plants, produced from coals of different rank (CTA and CTSR), and a fly ash (CTP) produced in a fluidized bed combustion (FBC) plant were used as raw materials. The mercury retention capacity of these fly ashes was compared to the retention obtained in different activated carbons. Although the capture of mercury is very similar in the gasification atmosphere and N{sub 2}, it is much more efficient in a coal combustion retention, being greater in fly ashes from PCC than those from FBC plants. 22 refs., 6 figs., 3 tabs.

  20. Interest in coal chemistry intensifies

    SciTech Connect (OSTI)

    Haggin, J.

    1982-08-09

    Research on coal structure has increased greatly in recent years as the future role of coal as a source of gaseous and liquid fuels, as well as chemicals, becomes more apparent. This paper reviews in some detail work being carried out in the US, particularly in the laboratories of Mobil and Exxon, and in the universities. New ideas on the chemical and physical structure of coal are put forward, and a proposal for a new classification system based on the fundamental properties of the vitrinite macerals is introduced.

  1. Technologist-in-Residence Documents

    Broader source: Energy.gov [DOE]

    These documents are related to the Clean Energy Manufacturing Initiative's Technologist-in-Residence Pilot. The Technologist-in-Residence Pilot will help catalyze strong Lab-Industry relationships that result in significant growth in high-impact collaborative research and development. The goals of the pilot are to 1) increase collaborative research and development between national laboratories and private sector companies, and 2) develop a streamlined method for companies to establish long term relationships with laboratories that result in collaborative research and development.

  2. Requesting an Increase in Allocation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Home » For Users » Accounts & Allocations » Allocations » Request More Time Requesting an Increase in Allocation If your project runs out of MPP time the project PI or its proxies may request additional time by sending an email to the DOE Allocations Manager responsible for NERSC Allocations in your DOE Science Office and Program. Your DOE Office and Program are displayed in the Project Information tab in NIM's Repository display area. To see this information, type your repo name in the

  3. Strata control in mineral engineering

    SciTech Connect (OSTI)

    Bieniawski, Z.T.

    1986-01-01

    This book covers the state-of-the-art of strata control practice both in the United States and abroad with respect to strata reinforcement by rock bolting, long wall mining technology and innovations in energy development, such as mining for oil and tunneling for storage of high-level nuclear waste in deep underground repositories. It features coverage of design concepts in rock engineering and rockbolt systems, stability of rock pillars, rockbursts, shaft design and construction and a detailed consideration of mineral and energy needs in the United States.

  4. Solar Parking Structure in California

    Broader source: Energy.gov [DOE]

    This photograph features the photovoltaic (PV) system at the Cal Expo in Sacramento, California, that was "made for the shade," but it does much more. Installed in September 2000, the 540-kilowatt PV system produces enough energy to power about 180 homes. In addition, the solar arrays serve as an oasis of shaded parking for 1,000 cars in a desert of scorching blacktop. The project was designed and built by Kyocera Solar/Utility Power Group for the Sacramento Municipal Utility District (SMUD). At the time, this was the largest parking lot solar system in the world today. Cal Expo is the site of many events, including the California State Fair.

  5. Global Warming in Geologic Time

    SciTech Connect (OSTI)

    David Archer

    2008-02-27

    The notion is pervasive in the climate science community and in the public at large that the climate impacts of fossil fuel CO2 release will only persist for a few centuries. This conclusion has no basis in theory or models of the atmosphere / ocean carbon cycle, which we review here. The largest fraction of the CO2 recovery will take place on time scales of centuries, as CO2 invades the ocean, but a significant fraction of the fossil fuel CO2, ranging in published models in the literature from 20-60%, remains airborne for a thousand years or longer. Ultimate recovery takes place on time scales of hundreds of thousands of years, a geologic longevity typically associated in public perceptions with nuclear waste. The glacial / interglacial climate cycles demonstrate that ice sheets and sea level respond dramatically to millennial-timescale changes in climate forcing. There are also potential positive feedbacks in the carbon cycle, including methane hydrates in the ocean, and peat frozen in permafrost, that are most sensitive to the long tail of the fossil fuel CO2 in the atmosphere.

  6. Global Warming in Geologic Time

    SciTech Connect (OSTI)

    Archer, David

    2008-02-27

    The notion is pervasive in the climate science community and in the public at large that the climate impacts of fossil fuel CO2 release will only persist for a few centuries. This conclusion has no basis in theory or models of the atmosphere/ ocean carbon cycle, which we review here. The largest fraction of the CO2 recovery will take place on time scales of centuries, as CO2 invades the ocean, but a significant fraction of the fossil fuel CO2, ranging in published models in the literature from 20-60%, remains airborne for a thousand years or longer. Ultimate recovery takes place on time scales of hundreds of thousands of years, a geologic longevity typically associated in public perceptions with nuclear waste. The glacial/interglacial climate cycles demonstrate that ice sheets and sea level respond dramatically to millennial-timescale changes in climate forcing. There are also potential positive feedbacks in the carbon cycle, including methane hydrates in the ocean, and peat frozen in permafrost, that are most sensitive to the long tail of the fossil fuel CO2 in the atmosphere.

  7. Global Warming in Geologic Time

    ScienceCinema (OSTI)

    David Archer

    2010-01-08

    The notion is pervasive in the climate science community and in the public at large that the climate impacts of fossil fuel CO2 release will only persist for a few centuries. This conclusion has no basis in theory or models of the atmosphere / ocean carbon cycle, which we review here. The largest fraction of the CO2 recovery will take place on time scales of centuries, as CO2 invades the ocean, but a significant fraction of the fossil fuel CO2, ranging in published models in the literature from 20-60%, remains airborne for a thousand years or longer. Ultimate recovery takes place on time scales of hundreds of thousands of years, a geologic longevity typically associated in public perceptions with nuclear waste. The glacial / interglacial climate cycles demonstrate that ice sheets and sea level respond dramatically to millennial-timescale changes in climate forcing. There are also potential positive feedbacks in the carbon cycle, including methane hydrates in the ocean, and peat frozen in permafrost, that are most sensitive to the long tail of the fossil fuel CO2 in the atmosphere.

  8. In-Drift Microbial Communities

    SciTech Connect (OSTI)

    D. Jolley

    2000-11-09

    As directed by written work direction (CRWMS M and O 1999f), Performance Assessment (PA) developed a model for microbial communities in the engineered barrier system (EBS) as documented here. The purpose of this model is to assist Performance Assessment and its Engineered Barrier Performance Section in modeling the geochemical environment within a potential repository drift for TSPA-SR/LA, thus allowing PA to provide a more detailed and complete near-field geochemical model and to answer the key technical issues (KTI) raised in the NRC Issue Resolution Status Report (IRSR) for the Evolution of the Near Field Environment (NFE) Revision 2 (NRC 1999). This model and its predecessor (the in-drift microbial communities model as documented in Chapter 4 of the TSPA-VA Technical Basis Document, CRWMS M and O 1998a) was developed to respond to the applicable KTIs. Additionally, because of the previous development of the in-drift microbial communities model as documented in Chapter 4 of the TSPA-VA Technical Basis Document (CRWMS M and O 1998a), the M and O was effectively able to resolve a previous KTI concern regarding the effects of microbial processes on seepage and flow (NRC 1998). This document supercedes the in-drift microbial communities model as documented in Chapter 4 of the TSPA-VA Technical Basis Document (CRWMS M and O 1998a). This document provides the conceptual framework of the revised in-drift microbial communities model to be used in subsequent performance assessment (PA) analyses.

  9. Enthalpy Diffusion in Multicomponent Flows

    SciTech Connect (OSTI)

    Cook, A W

    2008-11-12

    The enthalpy diffusion flux in the multicomponent energy equation is a well known yet frequently neglected term. It accounts for energy changes, associated with compositional changes, resulting from species diffusion. Enthalpy diffusion is important in flows where significant mixing occurs between species of dissimilar molecular weight. The term plays a critical role in preventing local violations of the entropy condition. In simulations of nonpremixed combustion, omission of the enthalpy flux can lead to anomalous temperature gradients, which may cause mixing regions to exceed ignition conditions. The term can also play a role in generating acoustic noise in turbulent mixing layers. Euler solvers that rely on numerical diffusion to mix fluids cannot accurately predict the temperature in mixed regions. On the other hand, Navier-Stokes solvers that incorporate enthalpy diffusion can provide much more accurate results.

  10. Covariance propagation in spectral indices

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Griffin, P. J.

    2015-01-09

    In this study, the dosimetry community has a history of using spectral indices to support neutron spectrum characterization and cross section validation efforts. An important aspect to this type of analysis is the proper consideration of the contribution of the spectrum uncertainty to the total uncertainty in calculated spectral indices (SIs). This study identifies deficiencies in the traditional treatment of the SI uncertainty, provides simple bounds to the spectral component in the SI uncertainty estimates, verifies that these estimates are reflected in actual applications, details a methodology that rigorously captures the spectral contribution to the uncertainty in the SI, andmore » provides quantified examples that demonstrate the importance of the proper treatment the spectral contribution to the uncertainty in the SI.« less

  11. Covariance propagation in spectral indices

    SciTech Connect (OSTI)

    Griffin, P. J.

    2015-01-09

    In this study, the dosimetry community has a history of using spectral indices to support neutron spectrum characterization and cross section validation efforts. An important aspect to this type of analysis is the proper consideration of the contribution of the spectrum uncertainty to the total uncertainty in calculated spectral indices (SIs). This study identifies deficiencies in the traditional treatment of the SI uncertainty, provides simple bounds to the spectral component in the SI uncertainty estimates, verifies that these estimates are reflected in actual applications, details a methodology that rigorously captures the spectral contribution to the uncertainty in the SI, and provides quantified examples that demonstrate the importance of the proper treatment the spectral contribution to the uncertainty in the SI.

  12. Variation in the annual average radon concentration measured in homes in Mesa County, Colorado

    SciTech Connect (OSTI)

    Rood, A.S.; George, J.L.; Langner, G.H. Jr.

    1990-04-01

    The purpose of this study is to examine the variability in the annual average indoor radon concentration. The TMC has been collecting annual average radon data for the past 5 years in 33 residential structures in Mesa County, Colorado. This report is an interim report that presents the data collected up to the present. Currently, the plans are to continue this study in the future. 62 refs., 3 figs., 12 tabs.

  13. Chaotic saddles in nonlinear modulational interactions in a plasma

    SciTech Connect (OSTI)

    Miranda, Rodrigo A.; Rempel, Erico L.; Chian, Abraham C.-L.

    2012-11-15

    A nonlinear model of modulational processes in the subsonic regime involving a linearly unstable wave and two linearly damped waves with different damping rates in a plasma is studied numerically. We compute the maximum Lyapunov exponent as a function of the damping rates in a two-parameter space, and identify shrimp-shaped self-similar structures in the parameter space. By varying the damping rate of the low-frequency wave, we construct bifurcation diagrams and focus on a saddle-node bifurcation and an interior crisis associated with a periodic window. We detect chaotic saddles and their stable and unstable manifolds, and demonstrate how the connection between two chaotic saddles via coupling unstable periodic orbits can result in a crisis-induced intermittency. The relevance of this work for the understanding of modulational processes observed in plasmas and fluids is discussed.

  14. Radiation from electrons in graphene in strong electric field

    SciTech Connect (OSTI)

    Yokomizo, N.

    2014-12-15

    We study the interaction of electrons in graphene with the quantized electromagnetic field in the presence of an applied uniform electric field using the Dirac model of graphene. Electronic states are represented by exact solutions of the Dirac equation in the electric background, and amplitudes of first-order Feynman diagrams describing the interaction with the photon field are calculated for massive Dirac particles in both valleys. Photon emission probabilities from a single electron and from a many-electron system at the charge neutrality point are derived, including the angular and frequency dependence, and several limiting cases are analyzed. The pattern of photon emission at the Dirac point in a strong field is determined by an interplay between the nonperturbative creation of electronhole pairs and spontaneous emission, allowing for the possibility of observing the Schwinger effect in measurements of the radiation emitted by pristine graphene under DC voltage.

  15. Observation of Materials Processes in Liquids in the Electron Microscope

    SciTech Connect (OSTI)

    Wang, Chong M.; Liao, Honggang; Ross, Frances M.

    2015-01-01

    Materials synthesis and the functioning of devices often indispensably involve liquid media. But direct visualization of dynamic process in liquids, especially with high spatial and temporal resolution, has been challenging. For solid materials, advances in aberration corrected electron microscopy have made observation of atomic level features a routine practice. Here we discuss the extent to which one can take advantage of the resolution of modern electron microscopes to image phenomenon occuring in liquids. We will describe the fundamentals of two different experimental approaches, closed and open liquid cells. We will illustrate the capabilities of each approach by considering processes in batteries and nucleation and growth of nanoparticles from solution. We conclude that liquid cell electron microscopy appears to be duly fulfilling its role for in situ studies of nanoscale processes in liquids, revealing physical and chemical processes otherwise difficult to observe.

  16. Particle deposition in ventilation ducts

    SciTech Connect (OSTI)

    Sippola, Mark R.

    2002-09-01

    Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 {micro}m were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on the experimental measurements was applied to evaluate particle losses in supply and return duct runs. Model results suggest that duct losses are negligible for particle sizes less than 1 {micro}m and complete for particle sizes greater than 50 {micro}m. Deposition to insulated ducts, horizontal duct floors and bends are predicted to control losses in duct systems. When combined with models for HVAC filtration and deposition to indoor surfaces to predict the ultimate fates of particles within buildings, these results suggest that ventilation ducts play only a small role in determining indoor particle concentrations, especially when HVAC filtration is present. However, the measured and modeled particle deposition rates are expected to be important for ventilation system contamination.

  17. Group-V intermixing in InAs/InP quantum dots

    SciTech Connect (OSTI)

    Chia, C.K.; Chua, S.J.; Tripathy, S.; Dong, J.R.

    2005-01-31

    Postgrowth intermixing in InAs/InP quantum dot (QD) structures have been investigated by rapid thermal annealing and laser irradiation techniques. In both cases, room-temperature photoluminescence (PL) measured from the QD structures after intermixing shows a substantial blueshift accompanied by an improvement in PL intensity and a reduction in linewidth. In the case of impurity free vacancy disordering, an energy shift of up to 350 meV has been achieved. The maximum differential energy shift for samples capped with SiO{sub 2} and SiN{sub x} dielectrics was found to be 90 meV. On the other hand, laser-induced intermixing allows differential energy shifts of more than 250 meV in this material system. Micro-Raman measurement shows the appearance of InAs-type and InP-type optical phonon peaks from laser-annealed InAs/InP QDs due to the exchange of As and P at the QD interfaces.

  18. Investigation of guided waves propagation in pipe buried in sand

    SciTech Connect (OSTI)

    Leinov, Eli; Cawley, Peter; Lowe, Michael J.S.

    2014-02-18

    The inspection of pipelines by guided wave testing is a well-established method for the detection of corrosion defects in pipelines, and is currently used routinely in a variety of industries, e.g. petrochemical and energy. When the method is applied to pipes buried in soil, test ranges tend to be significantly compromised because of attenuation of the waves caused by energy radiating into the soil. Moreover, the variability of soil conditions dictates different attenuation characteristics, which in-turn results in different, unpredictable, test ranges. We investigate experimentally the propagation and attenuation characteristics of guided waves in pipes buried in fine sand using a well characterized full scale experimental apparatus. The apparatus consists of an 8 inch-diameter, 5.6-meters long steel pipe embedded over 3 meters of its length in a rectangular container filled with fine sand, and an air-bladder for the application of overburden pressure. Longitudinal and torsional guided waves are excited in the pipe and recorded using a transducer ring (Guided Ultrasonics Ltd). Acoustic properties of the sand are measured independently in-situ and used to make model predictions of wave behavior in the buried pipe. We present the methodology and the systematic measurements of the guided waves under a range of conditions, including loose and compacted sand. It is found that the application of overburden pressure modifies the compaction of the sand and increases the attenuation, and that the measurement of the acoustic properties of sand allows model prediction of the attenuation of guided waves in buried pipes with a high level of confidence.

  19. Semiclassical eigenenergies in the wake of fast ions in solids

    SciTech Connect (OSTI)

    Mueller, J.; Burgdoerfer, J.; Noid, D.W. (Tennessee Univ., Knoxville, TN (USA). Dept. of Physics Oak Ridge National Lab., TN (USA))

    1990-01-01

    We compare the semiclassical and quantum mechanical eigenenergies of an electron in the wake of a fast, highly charged ion traversing a solid. The classical dynamics of this system shows a transition from regular to chaotic motion as a function of the binding energy. The transition can also be seen in the quantal spectra. We find evidence for a connection between bifurcation of tori and disorder in the energy level sequences. 21 refs., 4 figs.

  20. Quantum confined acceptors and donors in InSe nanosheets

    SciTech Connect (OSTI)

    Mudd, G. W.; Patan, A. Makarovsky, O.; Eaves, L.; Kudrynskyi, Z. R.; Kovalyuk, Z. D.; Fay, M. W.; Zlyomi, V.; Falko, V.

    2014-12-01

    We report on the radiative recombination of photo-excited carriers bound at native donors and acceptors in exfoliated nanoflakes of nominally undoped rhombohedral ?-polytype InSe. The binding energies of these states are found to increase with the decrease in flake thickness, L. We model their dependence on L using a two-dimensional hydrogenic model for impurities and show that they are strongly sensitive to the position of the impurities within the nanolayer.