National Library of Energy BETA

Sample records for four-stage cluster sampling

  1. THE PROPERTIES OF X-RAY COLD FRONTS IN A STATISTICAL SAMPLE OF SIMULATED GALAXY CLUSTERS

    SciTech Connect (OSTI)

    Hallman, Eric J.; Skillman, Samuel W.; Smith, Britton D.; Burns, Jack O.; Jeltema, Tesla E.; Norman, Michael L.

    2010-12-10

    We examine the incidence of cold fronts in a large sample of galaxy clusters extracted from a (512 h {sup -1} Mpc) hydrodynamic/N-body cosmological simulation with adiabatic gas physics computed with the Enzo adaptive mesh refinement code. This simulation contains a sample of roughly 4000 galaxy clusters with M {>=}10{sup 14} M{sub sun} at z = 0. For each simulated galaxy cluster, we have created mock 0.3-8.0 keV X-ray observations and spectroscopic-like temperature maps. We have searched these maps with a new automated algorithm to identify the presence of cold fronts in projection. Using a threshold of a minimum of 10 cold front pixels in our images, corresponding to a total comoving length L{sub cf}>156 h {sup -1} kpc, we find that roughly 10%-12% of all projections in a mass-limited sample would be classified as cold front clusters. Interestingly, the fraction of clusters with extended cold front features in our synthetic maps of a mass-limited sample trends only weakly with redshift out to z = 1.0. However, when using different selection functions, including a simulated flux limit, the trending with redshift changes significantly. The likelihood of finding cold fronts in the simulated clusters in our sample is a strong function of cluster mass. In clusters with M>7.5 x 10{sup 14} M{sub sun} the cold front fraction is 40%-50%. We also show that the presence of cold fronts is strongly correlated with disturbed morphology as measured by quantitative structure measures. Finally, we find that the incidence of cold fronts in the simulated cluster images is strongly dependent on baryonic physics.

  2. Studies of the mechanism of the cluster formation in a thermally sampling atmospheric pressure ionization mass spectrometer

    SciTech Connect (OSTI)

    Albrecht, Sascha Stroh, Fred; Klopotowski, Sebastian Derpmann, Valerie Klee, Sonja Brockmann, Klaus J. Benter, Thorsten

    2014-01-15

    In this study a thermally sampling atmospheric pressure ionization mass spectrometer is described and characterized. The ion transfer stage offers the capability to sample cluster ions at thermal equilibrium and during this transfer fundamental processes possibly affecting the cluster distribution are also readily identified. Additionally, the transfer stage combines optional collision-induced dissociation (CID) analysis of the cluster composition with thermal equilibrium sampling of clusters. The performance of the setup is demonstrated with regard to the proton-bound water cluster system. The benefit of the studied processes is that they can help to improve future transfer stages and to understand cluster ion reactions in ion mobility tubes and high-pressure ion sources. In addition, the instrument allows for the identification of fragmentation and protonation reactions caused by CID.

  3. Wedge sampling for computing clustering coefficients and triangle counts on large graphs

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

    Seshadhri, C.; Pinar, Ali; Kolda, Tamara G.

    2014-05-08

    Graphs are used to model interactions in a variety of contexts, and there is a growing need to quickly assess the structure of such graphs. Some of the most useful graph metrics are based on triangles, such as those measuring social cohesion. Despite the importance of these triadic measures, algorithms to compute them can be extremely expensive. We discuss the method of wedge sampling. This versatile technique allows for the fast and accurate approximation of various types of clustering coefficients and triangle counts. Furthermore, these techniques are extensible to counting directed triangles in digraphs. Our methods come with provable andmore » practical time-approximation tradeoffs for all computations. We provide extensive results that show our methods are orders of magnitude faster than the state of the art, while providing nearly the accuracy of full enumeration.« less

  4. 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.

  5. JOINT ANALYSIS OF CLUSTER OBSERVATIONS. II. CHANDRA/XMM-NEWTON X-RAY AND WEAK LENSING SCALING RELATIONS FOR A SAMPLE OF 50 RICH CLUSTERS OF GALAXIES

    SciTech Connect (OSTI)

    Mahdavi, Andisheh; Hoekstra, Henk; Babul, Arif; Bildfell, Chris; Jeltema, Tesla; Henry, J. Patrick

    2013-04-20

    We present a study of multiwavelength X-ray and weak lensing scaling relations for a sample of 50 clusters of galaxies. Our analysis combines Chandra and XMM-Newton data using an energy-dependent cross-calibration. After considering a number of scaling relations, we find that gas mass is the most robust estimator of weak lensing mass, yielding 15% {+-} 6% intrinsic scatter at r{sub 500}{sup WL} (the pseudo-pressure Y{sub X} yields a consistent scatter of 22% {+-} 5%). The scatter does not change when measured within a fixed physical radius of 1 Mpc. Clusters with small brightest cluster galaxy (BCG) to X-ray peak offsets constitute a very regular population whose members have the same gas mass fractions and whose even smaller (<10%) deviations from regularity can be ascribed to line of sight geometrical effects alone. Cool-core clusters, while a somewhat different population, also show the same (<10%) scatter in the gas mass-lensing mass relation. There is a good correlation and a hint of bimodality in the plane defined by BCG offset and central entropy (or central cooling time). The pseudo-pressure Y{sub X} does not discriminate between the more relaxed and less relaxed populations, making it perhaps the more even-handed mass proxy for surveys. Overall, hydrostatic masses underestimate weak lensing masses by 10% on the average at r{sub 500}{sup WL}; but cool-core clusters are consistent with no bias, while non-cool-core clusters have a large and constant 15%-20% bias between r{sub 2500}{sup WL} and r{sub 500}{sup WL}, in agreement with N-body simulations incorporating unthermalized gas. For non-cool-core clusters, the bias correlates well with BCG ellipticity. We also examine centroid shift variance and power ratios to quantify substructure; these quantities do not correlate with residuals in the scaling relations. Individual clusters have for the most part forgotten the source of their departures from self-similarity.

  6. HUBBLE SPACE TELESCOPE PROPER MOTION (HSTPROMO) CATALOGS OF GALACTIC GLOBULAR CLUSTERS. I. SAMPLE SELECTION, DATA REDUCTION, AND NGC7078 RESULTS

    SciTech Connect (OSTI)

    Bellini, A.; Anderson, J.; Van der Marel, R. P.; Watkins, L. L.; King, I. R.; Bianchini, P.; Chanam, J.; Chandar, R.; Cool, A. M.; Ferraro, F. R.; Massari, D.; Ford, H.

    2014-12-20

    We present the first study of high-precision internal proper motions (PMs) in a large sample of globular clusters, based on Hubble Space Telescope (HST) data obtained over the past decade with the ACS/WFC, ACS/HRC, and WFC3/UVIS instruments. We determine PMs for over 1.3 million stars in the central regions of 22 clusters, with a median number of ?60,000 stars per cluster. These PMs have the potential to significantly advance our understanding of the internal kinematics of globular clusters by extending past line-of-sight (LOS) velocity measurements to two- or three-dimensional velocities, lower stellar masses, and larger sample sizes. We describe the reduction pipeline that we developed to derive homogeneous PMs from the very heterogeneous archival data. We demonstrate the quality of the measurements through extensive Monte Carlo simulations. We also discuss the PM errors introduced by various systematic effects and the techniques that we have developed to correct or remove them to the extent possible. We provide in electronic form the catalog for NGC7078 (M 15), which consists of 77,837 stars in the central 2.'4. We validate the catalog by comparison with existing PM measurements and LOS velocities and use it to study the dependence of the velocity dispersion on radius, stellar magnitude (or mass) along the main sequence, and direction in the plane of the sky (radial or tangential). Subsequent papers in this series will explore a range of applications in globular-cluster science and will also present the PM catalogs for the other sample clusters.

  7. Mass calibration and cosmological analysis of the SPT-SZ galaxy cluster sample using velocity dispersion σ v and x-ray Y X measurements

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

    Bocquet, S.; Saro, A.; Mohr, J. J.; Aird, K. A.; Ashby, M. L. N.; Bautz, M.; Bayliss, M.; Bazin, G.; Benson, B. A.; Bleem, L. E.; et al

    2015-01-30

    Here, we present a velocity-dispersion-based mass calibration of the South Pole Telescope Sunyaev-Zel'dovich effect survey (SPT-SZ) galaxy cluster sample. Using a homogeneously selected sample of 100 cluster candidates from 720 deg2 of the survey along with 63 velocity dispersion (σv) and 16 X-ray YX measurements of sample clusters, we simultaneously calibrate the mass-observable relation and constrain cosmological parameters. Our method accounts for cluster selection, cosmological sensitivity, and uncertainties in the mass calibrators. The calibrations using σv and YX are consistent at the 0.6σ level, with the σ v calibration preferring ~16% higher masses. We use the full SPTCL data setmore » (SZ clusters+σv+YX) to measure σ8(Ωm/0.27)0.3 = 0.809 ± 0.036 within a flat ΛCDM model. The SPT cluster abundance is lower than preferred by either the WMAP9 or Planck+WMAP9 polarization (WP) data, but assuming that the sum of the neutrino masses is mν = 0.06 eV, we find the data sets to be consistent at the 1.0σ level for WMAP9 and 1.5σ for Planck+WP. Allowing for larger Σmν further reconciles the results. When we combine the SPTCL and Planck+WP data sets with information from baryon acoustic oscillations and Type Ia supernovae, the preferred cluster masses are 1.9σ higher than the YX calibration and 0.8σ higher than the σ v calibration. Given the scale of these shifts (~44% and ~23% in mass, respectively), we execute a goodness-of-fit test; it reveals no tension, indicating that the best-fit model provides an adequate description of the data. Using the multi-probe data set, we measure Ωm = 0.299 ± 0.009 and σ8 = 0.829 ± 0.011. Within a νCDM model we find Σmν = 0.148 ± 0.081 eV. We present a consistency test of the cosmic growth rate using SPT clusters. Allowing both the growth index γ and the dark energy equation-of-state parameter w to vary, we find γ = 0.73 ± 0.28 and w = –1.007 ± 0.065, demonstrating that the eΣxpansion and the growth

  8. The SEGUE Stellar Parameter Pipeline. IV. Validation with an Extended Sample of Galactic Globular and Open Clusters

    SciTech Connect (OSTI)

    Smolinski, Jason P.; Beers, Timothy C.; Lee, Young Sun; An, Deokkeun; Bickerton, Steven J.; Johnson, Jennifer A.; Loomis, Craig P.; Rockosi, Constance M.; Sivarani, Thirupathi; Yanny, Brian; /Fermilab

    2010-08-01

    Spectroscopic and photometric data for likely member stars of five Galactic globular clusters (M 3, M 53, M 71, M 92, and NGC 5053) and three open clusters (M 35, NGC 2158, and NGC 6791) are processed by the current version of the SEGUE Stellar Parameter Pipeline (SSPP), in order to determine estimates of metallicities and radial velocities for the clusters. These results are then compared to values from the literature. We find that the mean metallicity (<[Fe/H]>) and mean radial velocity (hRVi) estimates for each cluster are almost all within 2{sigma} of the adopted literature values; most are within 1{sigma}. We also demonstrate that the new version of the SSPP achieves small, but noteworthy, improvements in <[Fe/H]> estimates at the extrema of the cluster metallicity range, as compared to a previous version of the pipeline software. These results provide additional confidence in the application of the SSPP for studies of the abundances and kinematics of stellar populations in the Galaxy.

  9. THE SEGUE STELLAR PARAMETER PIPELINE. IV. VALIDATION WITH AN EXTENDED SAMPLE OF GALACTIC GLOBULAR AND OPEN CLUSTERS

    SciTech Connect (OSTI)

    Smolinski, Jason P.; Lee, Young Sun; Beers, Timothy C.; An, Deokkeun; Bickerton, Steven J.; Loomis, Craig P.; Johnson, Jennifer A.; Rockosi, Constance M.; Yanny, Brian E-mail: lee@pa.msu.edu E-mail: deokkeun@ewha.ac.kr E-mail: cloomis@astro.princeton.edu E-mail: crockosi@ucolick.org E-mail: yanny@fnal.gov

    2011-03-15

    Spectroscopic and photometric data for likely member stars of five Galactic globular clusters (M3, M53, M71, M92, and NGC 5053) and three open clusters (M35, NGC 2158, and NGC 6791) are processed by the current version of the SEGUE Stellar Parameter Pipeline (SSPP), in order to determine estimates of metallicities and radial velocities (RVs) for the clusters. These results are then compared to values from the literature. We find that the mean metallicity (([Fe/H])) and mean radial velocity ((RV)) estimates for each cluster are almost all within 2{sigma} of the adopted literature values; most are within 1{sigma}. We also demonstrate that the new version of the SSPP achieves small, but noteworthy, improvements in ([Fe/H]) estimates at the extrema of the cluster metallicity range, as compared to a previous version of the pipeline software. These results provide additional confidence in the application of the SSPP for studies of the abundances and kinematics of stellar populations in the Galaxy.

  10. Cluster Statistics

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

    Statistics Cluster Statistics Ganglia Ganglia can be used to monitor performance of PDSF nodes... Read More PDSF IO Monitoring This page shows the IO response of the elizas and...

  11. Cluster generator

    DOE Patents [OSTI]

    Donchev, Todor I.; Petrov, Ivan G.

    2011-05-31

    Described herein is an apparatus and a method for producing atom clusters based on a gas discharge within a hollow cathode. The hollow cathode includes one or more walls. The one or more walls define a sputtering chamber within the hollow cathode and include a material to be sputtered. A hollow anode is positioned at an end of the sputtering chamber, and atom clusters are formed when a gas discharge is generated between the hollow anode and the hollow cathode.

  12. Star formation and substructure in galaxy clusters

    SciTech Connect (OSTI)

    Cohen, Seth A.; Hickox, Ryan C.; Wegner, Gary A.; Einasto, Maret; Vennik, Jaan

    2014-03-10

    We investigate the relationship between star formation (SF) and substructure in a sample of 107 nearby galaxy clusters using data from the Sloan Digital Sky Survey. Several past studies of individual galaxy clusters have suggested that cluster mergers enhance cluster SF, while others find no such relationship. The SF fraction in multi-component clusters (0.228 0.007) is higher than that in single-component clusters (0.175 0.016) for galaxies with M{sub r}{sup 0.1}clusters, the fraction of star-forming galaxies increases with clustercentric distance and decreases with local galaxy number density, and multi-component clusters show a higher SF fraction than single-component clusters at almost all clustercentric distances and local densities. Comparing the SF fraction in individual clusters to several statistical measures of substructure, we find weak, but in most cases significant at greater than 2?, correlations between substructure and SF fraction. These results could indicate that cluster mergers may cause weak but significant SF enhancement in clusters, or unrelaxed clusters exhibit slightly stronger SF due to their less evolved states relative to relaxed clusters.

  13. Cluster Statistics

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

    Genepool Memory Heatmaps Usage Statistics UGE Scheduler Cycle Time File storage and I/O Data Management Supported Systems FAQ Performance and Optimization Genepool Completed Jobs Genepool Training and Tutorials Websites, databases and cluster services Queues and Scheduling Retired Systems Storage & File Systems Application Performance Data & Analytics Job Logs & Statistics Training & Tutorials Software Policies User Surveys NERSC Users Group Help Staff Blogs Request Repository

  14. THE EXTENDED VIRGO CLUSTER CATALOG

    SciTech Connect (OSTI)

    Kim, Suk; Rey, Soo-Chang; Lee, Youngdae; Chung, Jiwon; Pak, Mina; Yi, Wonhyeong; Lee, Woong; Jerjen, Helmut; Lisker, Thorsten; Sung, Eon-Chang

    2015-01-01

    We present a new catalog of galaxies in the wider region of the Virgo cluster, based on the Sloan Digital Sky Survey (SDSS) Data Release 7. The Extended Virgo Cluster Catalog (EVCC) covers an area of 725 deg{sup 2} or 60.1 Mpc{sup 2}. It is 5.2 times larger than the footprint of the classical Virgo Cluster Catalog (VCC) and reaches out to 3.5 times the virial radius of the Virgo cluster. We selected 1324 spectroscopically targeted galaxies with radial velocities less than 3000 km s{sup –1}. In addition, 265 galaxies that have been overlooked in the SDSS spectroscopic survey but have available redshifts in the NASA Extragalactic Database are also included. Our selection process secured a total of 1589 galaxies, 676 of which are not included in the VCC. The certain and possible cluster members are defined by means of redshift comparison with a cluster infall model. We employed two independent and complementary galaxy classification schemes: the traditional morphological classification based on the visual inspection of optical images and a characterization of galaxies from their spectroscopic features. SDSS u, g, r, i, and z passband photometry of all EVCC galaxies was performed using Source Extractor. We compare the EVCC galaxies with the VCC in terms of morphology, spatial distribution, and luminosity function. The EVCC defines a comprehensive galaxy sample covering a wider range in galaxy density that is significantly different from the inner region of the Virgo cluster. It will be the foundation for forthcoming galaxy evolution studies in the extended Virgo cluster region, complementing ongoing and planned Virgo cluster surveys at various wavelengths.

  15. Cluster Compatibility Mode

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

    Cluster Compatibility Mode Cluster Compatibility Mode Edison compute nodes run a stripped-down Linux operating system called Compute Node Linux (CNL). Some standard Linux services,...

  16. The C4 clustering algorithm: Clusters of galaxies in the Sloan Digital Sky Survey

    SciTech Connect (OSTI)

    Miller, Christopher J.; Nichol, Robert; Reichart, Dan; Wechsler, Risa H.; Evrard, August; Annis, James; McKay, Timothy; Bahcall, Neta; Bernardi, Mariangela; Boehringer, Hans; Connolly, Andrew; Goto, Tomo; Kniazev, Alexie; Lamb, Donald; Postman, Marc; Schneider, Donald; Sheth, Ravi; Voges, Wolfgang; /Cerro-Tololo InterAmerican Obs. /Portsmouth U., ICG /North Carolina U. /Chicago U., Astron. Astrophys. Ctr. /Chicago U., EFI /Michigan U. /Fermilab /Princeton U. Observ. /Garching, Max Planck Inst., MPE /Pittsburgh U. /Tokyo U., ICRR /Baltimore, Space Telescope Sci. /Penn State U. /Chicago U. /Stavropol, Astrophys. Observ. /Heidelberg, Max Planck Inst. Astron. /INI, SAO

    2005-03-01

    We present the ''C4 Cluster Catalog'', a new sample of 748 clusters of galaxies identified in the spectroscopic sample of the Second Data Release (DR2) of the Sloan Digital Sky Survey (SDSS). The C4 cluster-finding algorithm identifies clusters as overdensities in a seven-dimensional position and color space, thus minimizing projection effects that have plagued previous optical cluster selection. The present C4 catalog covers {approx}2600 square degrees of sky and ranges in redshift from z = 0.02 to z = 0.17. The mean cluster membership is 36 galaxies (with redshifts) brighter than r = 17.7, but the catalog includes a range of systems, from groups containing 10 members to massive clusters with over 200 cluster members with redshifts. The catalog provides a large number of measured cluster properties including sky location, mean redshift, galaxy membership, summed r-band optical luminosity (L{sub r}), velocity dispersion, as well as quantitative measures of substructure and the surrounding large-scale environment. We use new, multi-color mock SDSS galaxy catalogs, empirically constructed from the {Lambda}CDM Hubble Volume (HV) Sky Survey output, to investigate the sensitivity of the C4 catalog to the various algorithm parameters (detection threshold, choice of passbands and search aperture), as well as to quantify the purity and completeness of the C4 cluster catalog. These mock catalogs indicate that the C4 catalog is {approx_equal}90% complete and 95% pure above M{sub 200} = 1 x 10{sup 14} h{sup -1}M{sub {circle_dot}} and within 0.03 {le} z {le} 0.12. Using the SDSS DR2 data, we show that the C4 algorithm finds 98% of X-ray identified clusters and 90% of Abell clusters within 0.03 {le} z {le} 0.12. Using the mock galaxy catalogs and the full HV dark matter simulations, we show that the L{sub r} of a cluster is a more robust estimator of the halo mass (M{sub 200}) than the galaxy line-of-sight velocity dispersion or the richness of the cluster. However, if we

  17. Quantum Monte Carlo methods and lithium cluster properties. [Atomic clusters

    SciTech Connect (OSTI)

    Owen, R.K.

    1990-12-01

    Properties of small lithium clusters with sizes ranging from n = 1 to 5 atoms were investigated using quantum Monte Carlo (QMC) methods. Cluster geometries were found from complete active space self consistent field (CASSCF) calculations. A detailed development of the QMC method leading to the variational QMC (V-QMC) and diffusion QMC (D-QMC) methods is shown. The many-body aspect of electron correlation is introduced into the QMC importance sampling electron-electron correlation functions by using density dependent parameters, and are shown to increase the amount of correlation energy obtained in V-QMC calculations. A detailed analysis of D-QMC time-step bias is made and is found to be at least linear with respect to the time-step. The D-QMC calculations determined the lithium cluster ionization potentials to be 0.1982(14) (0.1981), 0.1895(9) (0.1874(4)), 0.1530(34) (0.1599(73)), 0.1664(37) (0.1724(110)), 0.1613(43) (0.1675(110)) Hartrees for lithium clusters n = 1 through 5, respectively; in good agreement with experimental results shown in the brackets. Also, the binding energies per atom was computed to be 0.0177(8) (0.0203(12)), 0.0188(10) (0.0220(21)), 0.0247(8) (0.0310(12)), 0.0253(8) (0.0351(8)) Hartrees for lithium clusters n = 2 through 5, respectively. The lithium cluster one-electron density is shown to have charge concentrations corresponding to nonnuclear attractors. The overall shape of the electronic charge density also bears a remarkable similarity with the anisotropic harmonic oscillator model shape for the given number of valence electrons.

  18. Cluster Bioenergia | Open Energy Information

    Open Energy Info (EERE)

    Cluster Bioenergia Jump to: navigation, search Name: Cluster Bioenergia Place: Mato Grosso, Brazil Product: Mato Grosso-based ethanol project developer company. References: Cluster...

  19. Technique for fast and efficient hierarchical clustering

    DOE Patents [OSTI]

    Stork, Christopher

    2013-10-08

    A fast and efficient technique for hierarchical clustering of samples in a dataset includes compressing the dataset to reduce a number of variables within each of the samples of the dataset. A nearest neighbor matrix is generated to identify nearest neighbor pairs between the samples based on differences between the variables of the samples. The samples are arranged into a hierarchy that groups the samples based on the nearest neighbor matrix. The hierarchy is rendered to a display to graphically illustrate similarities or differences between the samples.

  20. New TRACC Cluster Computer

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

    TRACC Cluster Computer With the addition of a new cluster called Zephyr that was made operational in September of this year (2012), TRACC now offers two clusters to choose from: Zephyr and our original cluster that has now been named Phoenix. Zephyr was acquired from Atipa technologies, and it is a 92-node system with each node having two AMD 16 core, 2.3 GHz, 32 GB processors. See also Computing Resources.

  1. Investigations of Galaxy Clusters Using Gravitational Lensing

    SciTech Connect (OSTI)

    Wiesner, Matthew P.

    2014-08-01

    In this dissertation, we discuss the properties of galaxy clusters that have been determined using strong and weak gravitational lensing. A galaxy cluster is a collection of galaxies that are bound together by the force of gravity, while gravitational lensing is the bending of light by gravity. Strong lensing is the formation of arcs or rings of light surrounding clusters and weak lensing is a change in the apparent shapes of many galaxies. In this work we examine the properties of several samples of galaxy clusters using gravitational lensing. In Chapter 1 we introduce astrophysical theory of galaxy clusters and gravitational lensing. In Chapter 2 we examine evidence from our data that galaxy clusters are more concentrated than cosmology would predict. In Chapter 3 we investigate whether our assumptions about the number of galaxies in our clusters was valid by examining new data. In Chapter 4 we describe a determination of a relationship between mass and number of galaxies in a cluster at higher redshift than has been found before. In Chapter 5 we describe a model of the mass distribution in one of the ten lensing systems discovered by our group at Fermilab. Finally in Chapter 6 we summarize our conclusions.

  2. Protections: Sampling

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

    Protections: Sampling Protections: Sampling Protection #3: Sampling for known and unexpected contaminants August 1, 2013 Monitoring stormwater in Los Alamos Canyon Monitoring stormwater in Los Alamos Canyon The Environmental Sampling Board, a key piece of the Strategy, ensures that LANL collects relevant and appropriate data to answer questions about the protection of human and environmental health, and to satisfy regulatory requirements. LANL must demonstrate the data are technically justified

  3. THE STELLAR MASS GROWTH OF BRIGHTEST CLUSTER GALAXIES IN THE IRAC SHALLOW CLUSTER SURVEY

    SciTech Connect (OSTI)

    Lin, Yen-Ting; Brodwin, Mark; Gonzalez, Anthony H.; Bode, Paul; Eisenhardt, Peter R. M.; Stanford, S. A.; Vikhlinin, Alexey

    2013-07-01

    The details of the stellar mass assembly of brightest cluster galaxies (BCGs) remain an unresolved problem in galaxy formation. We have developed a novel approach that allows us to construct a sample of clusters that form an evolutionary sequence, and have applied it to the Spitzer IRAC Shallow Cluster Survey (ISCS) to examine the evolution of BCGs in progenitors of present-day clusters with mass of (2.5-4.5) Multiplication-Sign 10{sup 14} M{sub Sun }. We follow the cluster mass growth history extracted from a high resolution cosmological simulation, and then use an empirical method that infers the cluster mass based on the ranking of cluster luminosity to select high-z clusters of appropriate mass from ISCS to be progenitors of the given set of z = 0 clusters. We find that, between z = 1.5 and 0.5, the BCGs have grown in stellar mass by a factor of 2.3, which is well-matched by the predictions from a state-of-the-art semi-analytic model. Below z = 0.5 we see hints of differences in behavior between the model and observation.

  4. Electron: Cluster interactions

    SciTech Connect (OSTI)

    Scheidemann, A.A.; Kresin, V.V.; Knight, W.D.

    1994-02-01

    Beam depletion spectroscopy has been used to measure absolute total inelastic electron-sodium cluster collision cross sections in the energy range from E {approximately} 0.1 to E {approximately} 6 eV. The investigation focused on the closed shell clusters Na{sub 8}, Na{sub 20}, Na{sub 40}. The measured cross sections show an increase for the lowest collision energies where electron attachment is the primary scattering channel. The electron attachment cross section can be understood in terms of Langevin scattering, connecting this measurement with the polarizability of the cluster. For energies above the dissociation energy the measured electron-cluster cross section is energy independent, thus defining an electron-cluster interaction range. This interaction range increases with the cluster size.

  5. Protections: Sampling

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

    Protection 3: Sampling for known and unexpected contaminants August 1, 2013 Monitoring stormwater in Los Alamos Canyon Monitoring stormwater in Los Alamos Canyon The Environmental ...

  6. Protections: Sampling

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

    and unexpected contaminants August 1, 2013 Monitoring stormwater in Los Alamos Canyon Monitoring stormwater in Los Alamos Canyon The Environmental Sampling Board, a key piece...

  7. Clustering versus non-clustering phase synchronizations

    SciTech Connect (OSTI)

    Liu, Shuai; University of Chinese Academy of Sciences, Beijing 100049 ; Zhan, Meng

    2014-03-15

    Clustering phase synchronization (CPS) is a common scenario to the global phase synchronization of coupled dynamical systems. In this work, a novel scenario, the non-clustering phase synchronization (NPS), is reported. It is found that coupled systems do not transit to the global synchronization until a certain sufficiently large coupling is attained, and there is no clustering prior to the global synchronization. To reveal the relationship between CPS and NPS, we further analyze the noise effect on coupled phase oscillators and find that the coupled oscillator system can change from CPS to NPS with the increase of noise intensity or system disorder. These findings are expected to shed light on the mechanism of various intriguing self-organized behaviors in coupled systems.

  8. Muster: Massively Scalable Clustering

    Energy Science and Technology Software Center (OSTI)

    2010-05-20

    Muster is a framework for scalable cluster analysis. It includes implementations of classic K-Medoids partitioning algorithms, as well as infrastructure for making these algorithms run scalably on very large systems. In particular, Muster contains algorithms such as CAPEK (described in reference 1) that are capable of clustering highly distributed data sets in-place on a hundred thousand or more processes.

  9. Matlab Cluster Ensemble Toolbox

    Energy Science and Technology Software Center (OSTI)

    2009-04-27

    This is a Matlab toolbox for investigating the application of cluster ensembles to data classification, with the objective of improving the accuracy and/or speed of clustering. The toolbox divides the cluster ensemble problem into four areas, providing functionality for each. These include, (1) synthetic data generation, (2) clustering to generate individual data partitions and similarity matrices, (3) consensus function generation and final clustering to generate ensemble data partitioning, and (4) implementation of accuracy metrics. Withmore » regard to data generation, Gaussian data of arbitrary dimension can be generated. The kcenters algorithm can then be used to generate individual data partitions by either, (a) subsampling the data and clustering each subsample, or by (b) randomly initializing the algorithm and generating a clustering for each initialization. In either case an overall similarity matrix can be computed using a consensus function operating on the individual similarity matrices. A final clustering can be performed and performance metrics are provided for evaluation purposes.« less

  10. Cool Cluster Correctly Correlated

    SciTech Connect (OSTI)

    Sergey Aleksandrovich Varganov

    2005-12-17

    Atomic clusters are unique objects, which occupy an intermediate position between atoms and condensed matter systems. For a long time it was thought that physical and chemical properties of atomic dusters monotonically change with increasing size of the cluster from a single atom to a condensed matter system. However, recently it has become clear that many properties of atomic clusters can change drastically with the size of the clusters. Because physical and chemical properties of clusters can be adjusted simply by changing the cluster's size, different applications of atomic clusters were proposed. One example is the catalytic activity of clusters of specific sizes in different chemical reactions. Another example is a potential application of atomic clusters in microelectronics, where their band gaps can be adjusted by simply changing cluster sizes. In recent years significant advances in experimental techniques allow one to synthesize and study atomic clusters of specified sizes. However, the interpretation of the results is often difficult. The theoretical methods are frequently used to help in interpretation of complex experimental data. Most of the theoretical approaches have been based on empirical or semiempirical methods. These methods allow one to study large and small dusters using the same approximations. However, since empirical and semiempirical methods rely on simple models with many parameters, it is often difficult to estimate the quantitative and even qualitative accuracy of the results. On the other hand, because of significant advances in quantum chemical methods and computer capabilities, it is now possible to do high quality ab-initio calculations not only on systems of few atoms but on clusters of practical interest as well. In addition to accurate results for specific clusters, such methods can be used for benchmarking of different empirical and semiempirical approaches. The atomic clusters studied in this work contain from a few atoms to

  11. SAMPLING SYSTEM

    DOE Patents [OSTI]

    Hannaford, B.A.; Rosenberg, R.; Segaser, C.L.; Terry, C.L.

    1961-01-17

    An apparatus is given for the batch sampling of radioactive liquids such as slurries from a system by remote control, while providing shielding for protection of operating personnel from the harmful effects of radiation.

  12. Sampling box

    DOE Patents [OSTI]

    Phillips, Terrance D.; Johnson, Craig

    2000-01-01

    An air sampling box that uses a slidable filter tray and a removable filter cartridge to allow for the easy replacement of a filter which catches radioactive particles is disclosed.

  13. Document clustering methods, document cluster label disambiguation methods, document clustering apparatuses, and articles of manufacture

    DOE Patents [OSTI]

    Sanfilippo, Antonio; Calapristi, Augustin J.; Crow, Vernon L.; Hetzler, Elizabeth G.; Turner, Alan E.

    2009-12-22

    Document clustering methods, document cluster label disambiguation methods, document clustering apparatuses, and articles of manufacture are described. In one aspect, a document clustering method includes providing a document set comprising a plurality of documents, providing a cluster comprising a subset of the documents of the document set, using a plurality of terms of the documents, providing a cluster label indicative of subject matter content of the documents of the cluster, wherein the cluster label comprises a plurality of word senses, and selecting one of the word senses of the cluster label.

  14. NREL: Process Development and Integration Laboratory - Sample Handling in

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

    the Atmospheric Processing Platform Sample Handling in the Atmospheric Processing Platform This page provides details on sample handling in the Atmospheric Processing platform. Photo of the large circular metal top of the cluster tool. Two wires cross the top and are attached to connectors on a flange at the center of the top. The chamber is surrounded by several other tools, but several of the cluster tool ports are open for future expansion. The robotic cluster tool portion of the

  15. SAMPLING OSCILLOSCOPE

    DOE Patents [OSTI]

    Sugarman, R.M.

    1960-08-30

    An oscilloscope is designed for displaying transient signal waveforms having random time and amplitude distributions. The oscilloscopc is a sampling device that selects for display a portion of only those waveforms having a particular range of amplitudes. For this purpose a pulse-height analyzer is provided to screen the pulses. A variable voltage-level shifter and a time-scale rampvoltage generator take the pulse height relative to the start of the waveform. The variable voltage shifter produces a voltage level raised one step for each sequential signal waveform to be sampled and this results in an unsmeared record of input signal waveforms. Appropriate delay devices permit each sample waveform to pass its peak amplitude before the circuit selects it for display.

  16. Sampling apparatus

    DOE Patents [OSTI]

    Gordon, Norman R.; King, Lloyd L.; Jackson, Peter O.; Zulich, Alan W.

    1989-01-01

    A sampling apparatus is provided for sampling substances from solid surfaces. The apparatus includes first and second elongated tubular bodies which telescopically and sealingly join relative to one another. An absorbent pad is mounted to the end of a rod which is slidably received through a passageway in the end of one of the joined bodies. The rod is preferably slidably and rotatably received through the passageway, yet provides a selective fluid tight seal relative thereto. A recess is formed in the rod. When the recess and passageway are positioned to be coincident, fluid is permitted to flow through the passageway and around the rod. The pad is preferably laterally orientable relative to the rod and foldably retractable to within one of the bodies. A solvent is provided for wetting of the pad and solubilizing or suspending the material being sampled from a particular surface.

  17. Sampling apparatus

    DOE Patents [OSTI]

    Gordon, N.R.; King, L.L.; Jackson, P.O.; Zulich, A.W.

    1989-07-18

    A sampling apparatus is provided for sampling substances from solid surfaces. The apparatus includes first and second elongated tubular bodies which telescopically and sealingly join relative to one another. An absorbent pad is mounted to the end of a rod which is slidably received through a passageway in the end of one of the joined bodies. The rod is preferably slidably and rotatably received through the passageway, yet provides a selective fluid tight seal relative thereto. A recess is formed in the rod. When the recess and passageway are positioned to be coincident, fluid is permitted to flow through the passageway and around the rod. The pad is preferably laterally orientable relative to the rod and foldably retractable to within one of the bodies. A solvent is provided for wetting of the pad and solubilizing or suspending the material being sampled from a particular surface. 15 figs.

  18. Industry Cluster Development Grant winners

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

    Industry Cluster Development Grant winners Community Connections: Your link to news and ... All Issues submit Industry Cluster Development Grant winners Recipients include Picuris ...

  19. Weighing galaxy clusters with gas. II. On the origin of hydrostatic mass bias in ?CDM galaxy clusters

    SciTech Connect (OSTI)

    Nelson, Kaylea; Nagai, Daisuke; Yu, Liang; Lau, Erwin T.; Rudd, Douglas H.

    2014-02-20

    The use of galaxy clusters as cosmological probes hinges on our ability to measure their masses accurately and with high precision. Hydrostatic mass is one of the most common methods for estimating the masses of individual galaxy clusters, which suffer from biases due to departures from hydrostatic equilibrium. Using a large, mass-limited sample of massive galaxy clusters from a high-resolution hydrodynamical cosmological simulation, in this work we show that in addition to turbulent and bulk gas velocities, acceleration of gas introduces biases in the hydrostatic mass estimate of galaxy clusters. In unrelaxed clusters, the acceleration bias is comparable to the bias due to non-thermal pressure associated with merger-induced turbulent and bulk gas motions. In relaxed clusters, the mean mass bias due to acceleration is small (? 3%), but the scatter in the mass bias can be reduced by accounting for gas acceleration. Additionally, this acceleration bias is greater in the outskirts of higher redshift clusters where mergers are more frequent and clusters are accreting more rapidly. Since gas acceleration cannot be observed directly, it introduces an irreducible bias for hydrostatic mass estimates. This acceleration bias places limits on how well we can recover cluster masses from future X-ray and microwave observations. We discuss implications for cluster mass estimates based on X-ray, Sunyaev-Zel'dovich effect, and gravitational lensing observations and their impact on cluster cosmology.

  20. Mantis BT Cluster Support

    Energy Science and Technology Software Center (OSTI)

    2009-06-05

    The software is a modidication to the Mantis BT V1.5 open source application provided by the mantis BT group to support cluster web servers. It also provides various cosmetic modifications used a LLNL.

  1. Dirac GPU Cluster

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

    Dirac Dirac GPU Cluster Current Status: Up NOTICE: Dirac was shut down permanently and retired from service at 17:00 on Friday, December 12, 2014. Dirac was a testbed experimental...

  2. Cluster Compatibility Mode

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

    Some standard Linux services, such as ssh, rsh, nscd, and ldap, are not supported on the ... It provides the standard Linux services needed to run most cluster-based independent ...

  3. ON THE CONNECTION BETWEEN GIANT RADIO HALOS AND CLUSTER MERGERS

    SciTech Connect (OSTI)

    Cassano, R.; Giacintucci, S.; Brunetti, G.; Venturi, T.

    2010-10-01

    The frequently observed association between giant radio halos (RHs) and merging galaxy clusters has driven present theoretical models of non-thermal emission from galaxy clusters, which are based on the idea that the energy dissipated during cluster-cluster mergers could power the formation of RHs. To quantitatively test the merger-halo connection, we present the first statistical study based on deep radio data and X-ray observations of a complete X-ray-selected sample of galaxy clusters with X-ray luminosity {>=}5 x 10{sup 44} erg s{sup -1} and redshift 0.2 {<=} z {<=} 0.32. Using several methods to characterize cluster substructures, namely, the power ratios, centroid shift, and X-ray brightness concentration parameter, we show that clusters with and without RH can be quantitatively differentiated in terms of their dynamical properties. In particular, we confirm that RHs are associated with dynamically disturbed clusters and clusters without RH are more 'relaxed', with only a couple of exceptions where a disturbed cluster does not exhibit a halo.

  4. BRIGHTEST CLUSTER GALAXIES AT THE PRESENT EPOCH

    SciTech Connect (OSTI)

    Lauer, Tod R.; Postman, Marc; Strauss, Michael A.; Graves, Genevieve J.; Chisari, Nora E.

    2014-12-20

    We have obtained photometry and spectroscopy of 433 z ? 0.08 brightest cluster galaxies (BCGs) in a full-sky survey of Abell clusters to construct a BCG sample suitable for probing deviations from the local Hubble flow. The BCG Hubble diagram over 0 < z < 0.08 is consistent to within 2% of the Hubble relation specified by a ? {sub m} = 0.3, ? = 0.7 cosmology. This sample allows us to explore the structural and photometric properties of BCGs at the present epoch, their location in their hosting galaxy clusters, and the effects of the cluster environment on their structure and evolution. We revisit the L{sub m} -? relation for BCGs, which uses ?, the log-slope of the BCG photometric curve of growth, to predict the metric luminosity in an aperture with 14.3kpc radius, L{sub m} , for use as a distance indicator. Residuals in the relation are 0.27mag rms. We measure central stellar velocity dispersions, ?, of the BCGs, finding the Faber-Jackson relation to flatten as the metric aperture grows to include an increasing fraction of the total BCG luminosity. A three-parameter ''metric plane'' relation using ? and ? together gives the best prediction of L{sub m} , with 0.21mag residuals. The distribution of projected spatial offsets, r{sub x} of BCGs from the X-ray-defined cluster center is a steep ? = 2.33 power law over 1 < r{sub x} < 10{sup 3}kpc. The median offset is ?10kpc, but ?15% of the BCGs have r{sub x} > 100kpc. The absolute cluster-dispersion normalized BCG peculiar velocity |?V {sub 1}|/? {sub c} follows an exponential distribution with scale length 0.39 0.03. Both L{sub m} and ? increase with ? {sub c}. The ? parameter is further moderated by both the spatial and velocity offset from the cluster center, with larger ? correlated with the proximity of the BCG to the cluster mean velocity or potential center. At the same time, position in the cluster has little effect on L{sub m} . Likewise, residuals from the metric plane show no correlation with either

  5. The era of star formation in galaxy clusters

    SciTech Connect (OSTI)

    Brodwin, M.; Stanford, S. A.; Gonzalez, Anthony H.; Mancone, C. L.; Gettings, D. P.; Zeimann, G. R.; Snyder, G. F.; Ashby, M. L. N.; Pope, A.; Alberts, S.; Eisenhardt, P. R.; Stern, D.; Moustakas, L. A.; Brown, M. J. I.; Chary, R.-R.; Dey, Arjun; Galametz, A.; Jannuzi, B. T.; Miller, E. D.; Moustakas, J.

    2013-12-20

    We analyze the star formation properties of 16 infrared-selected, spectroscopically confirmed galaxy clusters at 1 < z < 1.5 from the Spitzer/IRAC Shallow Cluster Survey (ISCS). We present new spectroscopic confirmation for six of these high-redshift clusters, five of which are at z > 1.35. Using infrared luminosities measured with deep Spitzer/Multiband Imaging Photometer for Spitzer observations at 24 μm, along with robust optical + IRAC photometric redshifts and spectral-energy-distribution-fitted stellar masses, we present the dust-obscured star-forming fractions, star formation rates, and specific star formation rates in these clusters as functions of redshift and projected clustercentric radius. We find that z ∼ 1.4 represents a transition redshift for the ISCS sample, with clear evidence of an unquenched era of cluster star formation at earlier times. Beyond this redshift, the fraction of star-forming cluster members increases monotonically toward the cluster centers. Indeed, the specific star formation rate in the cores of these distant clusters is consistent with field values at similar redshifts, indicating that at z > 1.4 environment-dependent quenching had not yet been established in ISCS clusters. By combining these observations with complementary studies showing a rapid increase in the active galactic nucleus (AGN) fraction, a stochastic star formation history, and a major merging episode at the same epoch in this cluster sample, we suggest that the starburst activity is likely merger-driven and that the subsequent quenching is due to feedback from merger-fueled AGNs. The totality of the evidence suggests we are witnessing the final quenching period that brings an end to the era of star formation in galaxy clusters and initiates the era of passive evolution.

  6. A consistent approach to falsifying ?CDM with rare galaxy clusters

    SciTech Connect (OSTI)

    Harrison, Ian; Hotchkiss, Shaun E-mail: shaun.hotchkiss@helsinki.fi

    2013-07-01

    We consider methods with which to answer the question ''is any observed galaxy cluster too unusual for ?CDM?'' After emphasising that many previous attempts to answer this question will overestimate the confidence level at which ?CDM can be ruled out, we outline a consistent approach to these rare clusters, which allows the question to be answered. We define three statistical measures, each of which are sensitive to changes in cluster populations arising from different modifications to the cosmological model. We also use these properties to define the ''equivalent mass at redshift zero'' for a cluster the mass of an equally unusual cluster today. This quantity is independent of the observational survey in which the cluster was found, which makes it an ideal proxy for ranking the relative unusualness of clusters detected by different surveys. These methods are then used on a comprehensive sample of observed galaxy clusters and we confirm that all are less than 2? deviations from the ?CDM expectation. Whereas we have only applied our method to galaxy clusters, it is applicable to any isolated, collapsed, halo. As motivation for future surveys, we also calculate where in the mass redshift plane the rarest halo is most likely to be found, giving information as to which objects might be the most fruitful in the search for new physics.

  7. Measuring consistent masses for 25 Milky Way globular clusters

    SciTech Connect (OSTI)

    Kimmig, Brian; Seth, Anil; Ivans, Inese I.; Anderton, Tim; Gregersen, Dylan; Strader, Jay; Caldwell, Nelson

    2015-02-01

    We present central velocity dispersions, masses, mass-to-light ratios (M/Ls ), and rotation strengths for 25 Galactic globular clusters (GCs). We derive radial velocities of 1951 stars in 12 GCs from single order spectra taken with Hectochelle on the MMT telescope. To this sample we add an analysis of available archival data of individual stars. For the full set of data we fit King models to derive consistent dynamical parameters for the clusters. We find good agreement between single-mass King models and the observed radial dispersion profiles. The large, uniform sample of dynamical masses we derive enables us to examine trends of M/L with cluster mass and metallicity. The overall values of M/L and the trends with mass and metallicity are consistent with existing measurements from a large sample of M31 clusters. This includes a clear trend of increasing M/L with cluster mass and lower than expected M/Ls for the metal-rich clusters. We find no clear trend of increasing rotation with increasing cluster metallicity suggested in previous work.

  8. FUEL ROD CLUSTERS

    DOE Patents [OSTI]

    Schultz, A.B.

    1959-08-01

    A cluster of nuclear fuel rods and a tubular casing therefor through which a coolant flows in heat-exchange contact with the fuel rods is described. The fuel rcds are held in the casing by virtue of the compressive force exerted between longitudinal ribs of the fuel rcds and internal ribs of the casing or the internal surfaces thereof.

  9. Environmental Business Cluster EBC | Open Energy Information

    Open Energy Info (EERE)

    Business Cluster EBC Jump to: navigation, search Name: Environmental Business Cluster (EBC) Place: San Jose, California Zip: CA 95113 Product: The Environmental Business Cluster is...

  10. Environmental Business Cluster | Open Energy Information

    Open Energy Info (EERE)

    Cluster Jump to: navigation, search Logo: Environmental Business Cluster Name: Environmental Business Cluster Address: 2 North First Street, Third Floor Place: San Jose, California...

  11. STAR CLUSTER DISRUPTION IN THE STARBURST GALAXY MESSIER 82

    SciTech Connect (OSTI)

    Li, Shuo; Li, Chengyuan; De Grijs, Richard; Anders, Peter

    2015-01-01

    Using high-resolution, multiple-passband Hubble Space Telescope images spanning the entire optical/near-infrared wavelength range, we obtained a statistically complete U-band-selected sample of 846 extended star clusters across the disk of the nearby starburst galaxy M82. Based on a careful analysis of the clusters' spectral energy distributions, we determined their galaxy-wide age and mass distributions. The M82 clusters exhibit three clear peaks in their age distribution, thus defining relatively young, log (t yr{sup 1}) ? 7.5, intermediate-age, log (t yr{sup 1}) in [7.5, 8.5], and old samples, log (t yr{sup 1}) ? 8.5. Comparison of the completeness-corrected mass distributions offers a firm handle on the galaxy's star cluster disruption history. The most massive star clusters in the young and old samples are (almost) all concentrated in the most densely populated central region, while the intermediate-age sample's most massive clusters are more spatially dispersed, which may reflect the distribution of the highest-density gas throughout the galaxy's evolutionary history, combined with the solid-body nature of the galaxy's central region.

  12. Deep Washington photometry of inconspicuous star cluster candidates in the Large Magellanic Cloud

    SciTech Connect (OSTI)

    Choudhury, Samyaday; Subramaniam, Annapurni; Piatti, Andrés E.

    2015-02-01

    We present deep Washington photometry of 45 poorly populated star cluster candidates in the Large Magellanic Cloud (LMC). We have performed a systematic study to estimate the parameters of the cluster candidates by matching theoretical isochrones to the cleaned and dereddened cluster color–magnitude diagrams. We were able to estimate the basic parameters for 33 clusters, out of which 23 are identified as single clusters and 10 are found to be members of double clusters. The other 12 cluster candidates have been classified as possible clusters/asterisms. About 50% of the true clusters are in the 100–300 Myr age range, whereas some are older or younger. We have discussed the distribution of age, location, and reddening with respect to field, as well as the size of true clusters. The sizes and masses of the studied sample are found to be similar to that of open clusters in the Milky Way. Our study adds to the lower end of cluster mass distribution in the LMC, suggesting that the LMC, apart from hosting rich clusters, also has formed small, less massive open clusters in the 100–300 Myr age range.

  13. Derivatized gold clusters and antibody-gold cluster conjugates

    DOE Patents [OSTI]

    Hainfeld, J.F.; Furuya, F.R.

    1994-11-01

    Antibody- or antibody fragment-gold cluster conjugates are shown wherein the conjugate size can be as small as 5.0 nm. Methods and reagents are disclosed in which antibodies, Fab' or F(ab')[sub 2] fragments are covalently bound to a stable cluster of gold atoms. The gold clusters may contain 6, 8, 9, 11, 13, 55 or 67 gold atoms in their inner core. The clusters may also contain radioactive gold. The antibody-cluster conjugates are useful in electron microscopy applications as well as in clinical applications that include imaging, diagnosis and therapy. 7 figs.

  14. Derivatized gold clusters and antibody-gold cluster conjugates

    DOE Patents [OSTI]

    Hainfeld, James F.; Furuya, Frederic R.

    1994-11-01

    Antibody- or antibody fragment-gold cluster conjugates are shown wherein the conjugate size can be as small as 5.0 nm. Methods and reagents are disclosed in which antibodies, Fab' or F(ab').sub.2 fragments thereof are covalently bound to a stable cluster of gold atoms. The gold clusters may contain 6, 8, 9, 11, 13, 55 or 67 gold atoms in their inner core. The clusters may also contain radioactive gold. The antibody-cluster conjugates are useful in electron microscopy applications as well as in clinical applications that include imaging, diagnosis and therapy.

  15. Connecting Remote Clusters with ATM

    SciTech Connect (OSTI)

    Hu, T.C.; Wyckoff, P.S.

    1998-10-01

    Sandia's entry into utilizing clusters of networked workstations is called Computational Plant or CPlant for short. The design of CPlant uses Ethernet to boot the individual nodes, Myrinet to communicate within a node cluster, and ATM to connect between remote clusters. This SAND document covers the work done to enable the use of ATM on the CPlant nodes in the Fall of 1997.

  16. The snapshot Hubble U-band cluster survey (SHUCS). II. The star cluster population of NGC 2997

    SciTech Connect (OSTI)

    Ryon, J. E.; Gallagher, J. S. III; Adamo, A.; Bastian, N.; Smith, L. J.; Konstantopoulos, I. S.; Larsen, S.; Zackrisson, E.

    2014-08-01

    We study the star cluster population of NGC 2997, a giant spiral galaxy located at 9.5 Mpc and targeted by the Snapshot Hubble U-band Cluster Survey (SHUCS). Combining our U-band imaging from SHUCS with archival BVI imaging from the Hubble Space Telescope, we select a high confidence sample of clusters in the circumnuclear ring and disk through a combination of automatic detection procedures and visual inspection. The cluster luminosity functions in all four filters can be approximated by power laws with indices of 1.7 to 2.3. Some deviations from pure power-law shape are observed, hinting at the presence of a high-mass truncation in the cluster mass function. However, upon inspection of the cluster mass function, we find it is consistent with a pure power law of index 2.2 0.2 despite a slight bend at ?2.5 10{sup 4} M {sub ?}. No statistically significant truncation is observed. From the cluster age distributions, we find a low rate of disruption (? ? 0.1) in both the disk and circumnuclear ring. Finally, we estimate the cluster formation efficiency (?) over the last 100 Myr in each region, finding 7% 2% for the disk, 12% 4% for the circumnuclear ring, and 10% 3% for the entire UBVI footprint. This study highlights the need for wide-field UBVI coverage of galaxies to study cluster populations in detail, though a small sample of clusters can provide significant insight into the characteristics of the population.

  17. α -cluster asymptotic normalization coefficients for nuclear...

    Office of Scientific and Technical Information (OSTI)

    -cluster asymptotic normalization coefficients for nuclear astrophysics Citation Details In-Document Search Title: -cluster asymptotic normalization coefficients for nuclear ...

  18. REVISITING SCALING RELATIONS FOR GIANT RADIO HALOS IN GALAXY CLUSTERS

    SciTech Connect (OSTI)

    Cassano, R.; Brunetti, G.; Venturi, T.; Kale, R.; Pratt, G. W.; Markevitch, M.

    2013-11-10

    Many galaxy clusters host megaparsec-scale radio halos, generated by ultrarelativistic electrons in the magnetized intracluster medium. Correlations between the synchrotron power of radio halos and the thermal properties of the hosting clusters were established in the last decade, including the connection between the presence of a halo and cluster mergers. The X-ray luminosity and redshift-limited Extended GMRT Radio Halo Survey provides a rich and unique dataset for statistical studies of the halos. We uniformly analyze the radio and X-ray data for the GMRT cluster sample, and use the new Planck Sunyaev-Zel'dovich (SZ) catalog to revisit the correlations between the power of radio halos and the thermal properties of galaxy clusters. We find that the radio power at 1.4 GHz scales with the cluster X-ray (0.1-2.4 keV) luminosity computed within R{sub 500} as P{sub 1.4}∼L{sup 2.1±0.2}{sub 500}. Our bigger and more homogenous sample confirms that the X-ray luminous (L{sub 500} > 5 × 10{sup 44} erg s{sup –1}) clusters branch into two populations—radio halos lie on the correlation, while clusters without radio halos have their radio upper limits well below that correlation. This bimodality remains if we excise cool cores from the X-ray luminosities. We also find that P{sub 1.4} scales with the cluster integrated SZ signal within R{sub 500}, measured by Planck, as P{sub 1.4}∼Y{sup 2.05±0.28}{sub 500}, in line with previous findings. However, contrary to previous studies that were limited by incompleteness and small sample size, we find that 'SZ-luminous' Y{sub 500} > 6 × 10{sup –5} Mpc{sup 2} clusters show a bimodal behavior for the presence of radio halos, similar to that in the radio-X-ray diagram. Bimodality of both correlations can be traced to clusters dynamics, with radio halos found exclusively in merging clusters. These results confirm the key role of mergers for the origin of giant radio halos, suggesting that they trigger the relativistic particle

  19. COMPARISONS OF COSMOLOGICAL MAGNETOHYDRODYNAMIC GALAXY CLUSTER SIMULATIONS TO RADIO OBSERVATIONS

    SciTech Connect (OSTI)

    Xu Hao; Li Hui; Collins, David C.; Govoni, Federica; Murgia, Matteo; Norman, Michael L.; Cen Renyue; Feretti, Luigina; Giovannini, Gabriele E-mail: hli@lanl.gov E-mail: mlnorman@ucsd.edu E-mail: matteo@oa-cagliari.inaf.it E-mail: lferetti@ira.inaf.it

    2012-11-01

    Radio observations of galaxy clusters show that there are {mu}G magnetic fields permeating the intracluster medium (ICM), but it is hard to accurately constrain the strength and structure of the magnetic fields without the help of advanced computer simulations. We present qualitative comparisons of synthetic Very Large Array observations of simulated galaxy clusters to radio observations of Faraday rotation measure (RM) and radio halos. The cluster formation is modeled using adaptive mesh refinement magnetohydrodynamic simulations with the assumption that the initial magnetic fields are injected into the ICM by active galactic nuclei (AGNs) at high redshift. In addition to simulated clusters in Xu et al., we present a new simulation with magnetic field injections from multiple AGNs. We find that the cluster with multiple injection sources is magnetized to a similar level as in previous simulations with a single AGN. The RM profiles from simulated clusters, both |RM| and the dispersion of RM ({sigma}{sub RM}), are consistent at a first order with the radial distribution from observations. The correlations between the {sigma}{sub RM} and X-ray surface brightness from simulations are in a broad agreement with the observations, although there is an indication that the simulated clusters could be slightly overdense and less magnetized with respect to those in the observed sample. In addition, the simulated radio halos agree with the observed correlations between the radio power versus the cluster X-ray luminosity and between the radio power versus the radio halo size. These studies show that the cluster-wide magnetic fields that originate from AGNs and are then amplified by the ICM turbulence match observations of magnetic fields in galaxy clusters.

  20. TOWARD UNBIASED GALAXY CLUSTER MASSES FROM LINE-OF-SIGHT VELOCITY DISPERSIONS

    SciTech Connect (OSTI)

    Saro, Alex; Mohr, Joseph J.; Bazin, Gurvan; Dolag, Klaus

    2013-07-20

    We study the use of red-sequence-selected galaxy spectroscopy for unbiased estimation of galaxy cluster masses by using a publicly available simulated galaxy catalog. We explore the impact of selection using galaxy color, projected separation from the cluster center, galaxy luminosity, and spectroscopic redshift. We identify and characterize each of the following sources of bias and scatter in velocity dispersion at fixed mass: the intrinsic properties of halos in the form of halo triaxiality, sampling noise, the presence of multiple kinematic populations within the cluster, and the effect of interlopers. We show that even in red-sequence and spectroscopically selected galaxy samples, the interloper fraction is significant, and that the variations in the interloper population from cluster to cluster provide the dominant contribution to the velocity dispersion scatter at fixed mass. We present measurements of the total scatter in dispersion at fixed mass as a function of the number of redshifts. Results indicate that improvements in scatter are modest beyond samples of {approx}30 redshifts per cluster. Our results show that while cluster velocity dispersions extracted from a few dozen red-sequence-selected galaxies do not provide precise masses on a single cluster basis, an ensemble of cluster velocity dispersions can be combined to produce a precise calibration of a cluster survey-mass-observable relation. Currently, disagreements in the literature on simulated subhalo velocity dispersion-mass relations place a systematic floor on velocity dispersion mass calibration at the 5% level in dispersion.

  1. Analysis of Cluster Management Tools

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

    Analysis of Configuration Management Tools Computer System, Cluster, and Networking Summer Institute Team: Evan Leeseberg, James Kang, Katherine Nystrom Mentors: Kevin Tegtmeier,...

  2. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Salmon, Mississippi, Site, Water Sampling Location Map .........5 Water Sampling Field Activities Verification ...

  3. September 2004 Water Sampling

    Office of Legacy Management (LM)

    .........1 Water Sampling Locations at the Rulison, .........3 Water Sampling Field Activities Verification ...

  4. Antibody-gold cluster conjugates

    DOE Patents [OSTI]

    Hainfeld, J.F.

    1988-06-28

    Antibody- or antibody fragment-gold cluster conjugates are shown wherein the conjugate size can be about 5.0 nm. Methods and reagents are disclosed in which antibodies or Fab' fragments thereof are covalently bound to a stable cluster of gold atoms. 2 figs.

  5. Single System Image Cluster Management

    Energy Science and Technology Software Center (OSTI)

    2004-02-13

    Cluster computing has quickly proven itself to be a capable workhorse for a wide variety of production computing tasks; however, setting up and maintaining a cluster still requires significantly more effort than administrating just a single machine. As computing hardware descreases in price and cluster sizes grow, it is becoming increasingly important to manage clusters cleverly so that a system administration effort can "scale" as well. To ease the task of mananging many machines, administratorsmore » often deploy an environment that is homogeneous across all nodes of a cluster, and maintain a snapshot of the filesystem as a 'master image'. However due to operational, behavioral, and physical constraints, many nodes often require numerous deviations from the master image in order to operate as desired.« less

  6. Weak Lensing by Galaxy Clusters: from Pixels to Cosmology

    SciTech Connect (OSTI)

    Gruen, Daniel

    2015-03-11

    The story of the origin and evolution of our Universe is told, equivalently, by space-time itself and by the structures that grow inside of it. Clusters of galaxies are the frontier of bottom-up structure formation. They are the most massive objects to have collapsed at the present epoch. By that virtue, their abundance and structural parameters are highly sensitive to the composition and evolution of the Universe. The most common probe of cluster cosmology, abundance, uses samples of clusters selected by some observable. Applying a mass-observable relation (MOR), cosmological parameters can be constrained by comparing the sample to predicted cluster abundances as a function of observable and redshift. Arguably, however, cluster probes have not yet entered the era of per cent level precision cosmology. The primary reason for this is our imperfect understanding of the MORs. The overall normalization, the slope of mass vs. observable, the redshift evolution, and the degree and correlation of intrinsic scatters of observables at fixed mass have to be constrained for interpreting abundances correctly. Mass measurement of clusters by means of the differential deflection of light from background sources in their gravitational field, i.e. weak lensing, is a powerful approach for achieving this. This thesis presents new methods for and scientific results of weak lensing measurements of clusters of galaxies. The former include, on the data reduction side, (i) the correction of CCD images for non-linear effects due to the electric fields of accumulated charges and (ii) a method for masking artifact features in sets of overlapping images of the sky by comparison to the median image. Also, (iii) I develop a method for the selection of background galaxy samples based on their color and apparent magnitude that includes a new correction for contamination with cluster member galaxies. The main scientific results are the following. (i) For the Hubble Frontier Field cluster RXC J

  7. September 2004 Water Sampling

    Office of Legacy Management (LM)

    4 Groundwater and Surface Water Sampling at the Slick Rock, Colorado, Processing Sites .........7 Water Sampling Field Activities Verification ...

  8. September 2004 Water Sampling

    Office of Legacy Management (LM)

    and Surface Water Sampling at the Green River, Utah, Disposal Site August 2014 LMSGRN.........7 Water Sampling Field Activities Verification ...

  9. September 2004 Water Sampling

    Office of Legacy Management (LM)

    and May 2014 Groundwater and Surface Water Sampling at the Shiprock, New Mexico, Disposal .........9 Water Sampling Field Activities Verification ...

  10. September 2004 Water Sampling

    Office of Legacy Management (LM)

    and Surface Water Sampling at the Rio Blanco, Colorado, Site October 2014 LMSRBLS00514 .........5 Water Sampling Field Activities Verification ...

  11. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Natural Gas and Produced Water Sampling at the Rulison, Colorado, Site November 2014 LMS.........3 Water Sampling Field Activities Verification ...

  12. September 2004 Water Sampling

    Office of Legacy Management (LM)

    5 Groundwater and Surface Water Sampling at the Rulison, Colorado, Site October 2015 LMS.........5 Water Sampling Field Activities Verification ...

  13. September 2004 Water Sampling

    Office of Legacy Management (LM)

    and Surface Water Sampling at the Monticello, Utah, Processing Site July 2015 LMSMNT.........7 Water Sampling Field Activities Verification ...

  14. September 2004 Water Sampling

    Office of Legacy Management (LM)

    2015 Groundwater and Surface Water Sampling at the Shiprock, New Mexico, Disposal Site .........9 Water Sampling Field Activities Verification ...

  15. September 2004 Water Sampling

    Office of Legacy Management (LM)

    and Surface Water Sampling at the Rio Blanco, Colorado, Site October 2015 LMSRBLS00515 .........5 Water Sampling Field Activities Verification ...

  16. September 2004 Water Sampling

    Office of Legacy Management (LM)

    5 Produced Water Sampling at the Rulison, Colorado, Site May 2015 LMSRULS00115 Available .........3 Water Sampling Field Activities Verification ...

  17. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Natural Gas and Produced Water Sampling at the Gasbuggy, New Mexico, Site December 2013 .........5 Water Sampling Field Activities Verification ...

  18. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Produced Water Sampling at the Rulison, Colorado, Site January 2016 LMSRULS00915 .........3 Water Sampling Field Activities Verification ...

  19. September 2004 Water Sampling

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    3 Groundwater and Surface Water Sampling at the Monument Valley, Arizona, Processing Site .........7 Water Sampling Field Activities Verification ...

  20. September 2004 Water Sampling

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    July 2015 Groundwater and Surface Water Sampling at the Gunnison, Colorado, Processing .........5 Water Sampling Field Activities Verification ...

  1. September 2004 Water Sampling

    Office of Legacy Management (LM)

    and Surface Water Sampling at the Monticello, Utah, Processing Site July 2014 LMSMNT.........7 Water Sampling Field Activities Verification ...

  2. September 2004 Water Sampling

    Office of Legacy Management (LM)

    3 Water Sampling at the Monticello, Utah, Processing Site January 2014 LMSMNTS01013 This .........7 Water Sampling Field Activities Verification ...

  3. September 2004 Water Sampling

    Office of Legacy Management (LM)

    and Surface Water Sampling at the Naturita, Colorado Processing Site October 2013 LMSNAP.........5 Water Sampling Field Activities Verification ...

  4. September 2004 Water Sampling

    Office of Legacy Management (LM)

    4 Groundwater and Surface Water Sampling at the Gunnison, Colorado, Processing Site .........5 Water Sampling Field Activities Verification ...

  5. September 2004 Water Sampling

    Office of Legacy Management (LM)

    and Surface Water Sampling at the Tuba City, Arizona, Disposal Site November 2013 LMSTUB.........9 Water Sampling Field Activities Verification ...

  6. September 2004 Water Sampling

    Office of Legacy Management (LM)

    5 Groundwater and Surface Water Sampling at the Monticello, Utah, Processing Site January .........7 Water Sampling Field Activities Verification ...

  7. Dust cluster explosion

    SciTech Connect (OSTI)

    Saxena, Vikrant [School of Mathematics and Physics, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); Institute for Plasma Research, Bhat, Gandhinagar (India); Avinash, K. [Department of Physics and Astrophysics, University of Delhi, New Delhi (India); Sen, A. [Institute for Plasma Research, Bhat, Gandhinagar (India)

    2012-09-15

    A model for the dust cluster explosion where micron/sub-micron sized particles are accelerated at the expense of plasma thermal energy, in the afterglow phase of a complex plasma discharge is proposed. The model is tested by molecular dynamics simulations of dust particles in a confining potential. The nature of the explosion (caused by switching off the discharge) and the concomitant dust acceleration is found to depend critically on the pressure of the background neutral gas. At low gas pressure, the explosion is due to unshielded Coulomb repulsion between dust particles and yields maximum acceleration, while in the high pressure regime it is due to shielded Yukawa repulsion and yields much feebler acceleration. These results are in agreement with experimental findings. Our simulations also confirm a recently proposed electrostatic (ES) isothermal scaling relation, P{sub E}{proportional_to}V{sub d}{sup -2} (where P{sub E} is the ES pressure of the dust particles and V{sub d} is the confining volume).

  8. SEARCHING FOR COOLING SIGNATURES IN STRONG LENSING GALAXY CLUSTERS: EVIDENCE AGAINST BARYONS SHAPING THE MATTER DISTRIBUTION IN CLUSTER CORES

    SciTech Connect (OSTI)

    Blanchard, Peter K.; Bayliss, Matthew B.; McDonald, Michael; Dahle, Hakon; Gladders, Michael D.; Sharon, Keren; Mushotzky, Richard

    2013-07-20

    The process by which the mass density profile of certain galaxy clusters becomes centrally concentrated enough to produce high strong lensing (SL) cross-sections is not well understood. It has been suggested that the baryonic condensation of the intracluster medium (ICM) due to cooling may drag dark matter to the cores and thus steepen the profile. In this work, we search for evidence of ongoing ICM cooling in the first large, well-defined sample of SL selected galaxy clusters in the range 0.1 < z < 0.6. Based on known correlations between the ICM cooling rate and both optical emission line luminosity and star formation, we measure, for a sample of 89 SL clusters, the fraction of clusters that have [O II]{lambda}{lambda}3727 emission in their brightest cluster galaxy (BCG). We find that the fraction of line-emitting BCGs is constant as a function of redshift for z > 0.2 and shows no statistically significant deviation from the total cluster population. Specific star formation rates, as traced by the strength of the 4000 A break, D{sub 4000}, are also consistent with the general cluster population. Finally, we use optical imaging of the SL clusters to measure the angular separation, R{sub arc}, between the arc and the center of mass of each lensing cluster in our sample and test for evidence of changing [O II] emission and D{sub 4000} as a function of R{sub arc}, a proxy observable for SL cross-sections. D{sub 4000} is constant with all values of R{sub arc}, and the [O II] emission fractions show no dependence on R{sub arc} for R{sub arc} > 10'' and only very marginal evidence of increased weak [O II] emission for systems with R{sub arc} < 10''. These results argue against the ability of baryonic cooling associated with cool core activity in the cores of galaxy clusters to strongly modify the underlying dark matter potential, leading to an increase in SL cross-sections.

  9. Advanced Health Monitoring of Computer Cluster

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

    Sherry Salas Mentors: Susan Coulter, Andree Jacobson, Kevin Tegtmeier LANL ISTIIAS ClusterNetwork Management Summer Institute August 2, 2007 Problem As a cluster grows in...

  10. A Clustering Graph Generator

    SciTech Connect (OSTI)

    Winlaw, Manda; De Sterck, Hans; Sanders, Geoffrey

    2015-10-26

    In very simple terms a network can be de ned as a collection of points joined together by lines. Thus, networks can be used to represent connections between entities in a wide variety of elds including engi- neering, science, medicine, and sociology. Many large real-world networks share a surprising number of properties, leading to a strong interest in model development research and techniques for building synthetic networks have been developed, that capture these similarities and replicate real-world graphs. Modeling these real-world networks serves two purposes. First, building models that mimic the patterns and prop- erties of real networks helps to understand the implications of these patterns and helps determine which patterns are important. If we develop a generative process to synthesize real networks we can also examine which growth processes are plausible and which are not. Secondly, high-quality, large-scale network data is often not available, because of economic, legal, technological, or other obstacles [7]. Thus, there are many instances where the systems of interest cannot be represented by a single exemplar network. As one example, consider the eld of cybersecurity, where systems require testing across diverse threat scenarios and validation across diverse network structures. In these cases, where there is no single exemplar network, the systems must instead be modeled as a collection of networks in which the variation among them may be just as important as their common features. By developing processes to build synthetic models, so-called graph generators, we can build synthetic networks that capture both the essential features of a system and realistic variability. Then we can use such synthetic graphs to perform tasks such as simulations, analysis, and decision making. We can also use synthetic graphs to performance test graph analysis algorithms, including clustering algorithms and anomaly detection algorithms.

  11. MEASUREMENT OF THE HALO BIAS FROM STACKED SHEAR PROFILES OF GALAXY CLUSTERS

    SciTech Connect (OSTI)

    Covone, Giovanni; Sereno, Mauro

    2014-04-01

    We present observational evidence of the two-halo term in the stacked shear profile of a sample of ?1200 optically selected galaxy clusters based on imaging data and the public shear catalog from the CFHTLenS. We find that the halo bias, a measure of the correlated distribution of matter around galaxy clusters, has amplitude and correlation with galaxy cluster mass in very good agreement with the predictions based on the LCDM standard cosmological model. The mass-concentration relation is flat but higher than theoretical predictions. We also confirm the close scaling relation between the optical richness of galaxy clusters and their mass.

  12. Industry Cluster Development Grant winners

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

    Industry Cluster Development Grant winners Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue: September 1, 2016 all issues All Issues » submit Industry Cluster Development Grant winners Recipients include Picuris Pueblo and Rio Arriba County February 1, 2015 A new community mural on the Hunter Ford facility in Española celebrates the building's planned revitalization and the future location of the Northern New Mexico Food Hub. A new

  13. LCLS Sample Preparation Laboratory | Sample Preparation Laboratories

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

    LCLS Sample Preparation Laboratory Kayla Zimmerman | (650) 926-6281 Lisa Hammon, LCLS Lab Coordinator Welcome to the LCLS Sample Preparation Laboratory. This small general use wet lab is located in Rm 109 of the Far Experimental Hall near the MEC, CXI, and XCS hutches. It conveniently serves all LCLS hutches and is available for final stage sample preparation. Due to space limitations, certain types of activities may be restricted and all access must be scheduled in advance. User lab bench

  14. Completion Report for Well Cluster ER-6-1

    SciTech Connect (OSTI)

    Bechtel Nevada

    2004-10-01

    Well Cluster ER-6-1 was constructed for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Division at the Nevada Test Site, Nye County, Nevada. This work was initiated as part of the Groundwater Characterization Project, now known as the Underground Test Area Project. The well cluster is located in southeastern Yucca Flat. Detailed lithologic descriptions with stratigraphic assignments for Well Cluster ER-6-1 are included in this report. These are based on composite drill cuttings collected every 3 meters and conventional core samples taken below 639 meters, supplemented by geophysical log data. Detailed petrographic, chemical, and mineralogical studies of rock samples were conducted on 11 samples to resolve complex interrelationships between several of the Tertiary tuff units. Additionally, paleontological analyses by the U.S. Geological Survey confirmed the stratigraphic assignments below 539 meters within the Paleozoic sedimentary section. All three wells in the Well ER-6-1 cluster were drilled within the Quaternary and Tertiary alluvium section, the Tertiary volcanic section, and into the Paleozoic sedimentary section.

  15. Chemistry of Tantalum Clusters in Solution And on SiO(2) Supports: Analogies And Contrasts

    SciTech Connect (OSTI)

    Nemana, S.; Okamoto, N.L.; Browning, N.D.; Gates, B.C.

    2009-06-03

    Tantalum clusters have been synthesized from Ta(CH{sub 2}Ph){sub 5} on the surface of porous fumed SiO{sub 2}. When these clusters are small, incorporating, on average, several Ta atoms, their chemistry is similar to that of molecular tantalum clusters (and other early transition-metal) clusters. For example, The Ta-Ta bonds in these small supported clusters have been characterized by extended X-ray absorption fine structure (EXAFS), IR, and UV-vis spectroscopy, being similar to those in molecular analogues. The redox reactions of the supported clusters, characterized by X-ray absorption near-edge structure, are analogous to those of early transition-metal clusters in solution. In contrast to the largest of these clusters in solution and in the solid state, those supported on SiO{sub 2} are raftlike, facilitating the substantial metal-support-oxygen bonding that is evident in the EXAFS spectra. Samples consisting of tantalum clusters on SiO{sub 2} catalyze alkane disproportionation and the conversion of methane with n-butane to give other alkanes, but catalytic properties of analogous clusters in solution have barely been explored.

  16. September 2004 Water Sampling

    Office of Legacy Management (LM)

    ... Inductively Coupled Plasma (ICP) Interference Check Sample (ICS) Analysis ICP interference check samples ICSA and ICSAB were analyzed at the required frequency to verify the ...

  17. September 2004 Water Sampling

    Office of Legacy Management (LM)

    5 Groundwater and Surface Water Sampling at the Tuba City, Arizona Disposal Site June 2015 .........7 Water Sampling Field Activities Verification ...

  18. Visual Sample Plan Flyer

    Office of Energy Efficiency and Renewable Energy (EERE)

    This flyer better explains that VSP is a free, easy-to-use software tool that supports development of optimal sampling plans based on statistical sampling theory.

  19. Internal gettering by metal alloy clusters

    DOE Patents [OSTI]

    Buonassisi, Anthony; Heuer, Matthias; Istratov, Andrei A.; Pickett, Matthew D.; Marcus, Mathew A.; Weber, Eicke R.

    2010-07-27

    The present invention relates to the internal gettering of impurities in semiconductors by metal alloy clusters. In particular, intermetallic clusters are formed within silicon, such clusters containing two or more transition metal species. Such clusters have melting temperatures below that of the host material and are shown to be particularly effective in gettering impurities within the silicon and collecting them into isolated, less harmful locations. Novel compositions for some of the metal alloy clusters are also described.

  20. Course Clusters | Photosynthetic Antenna Research Center

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

    Course Clusters Course Clusters Courses are organized into three discipline clusters: (1) Social Sciences & Humanities; (2) Architecture; and, (3) Natural Sciences & Engineering. According to the certificate's requirements, students must select curriculum options from at least two of the three clusters. Course information and/or descriptions that appear below were obtained from courses.wustl.edu. Please also see our printable course listing. Register for courses on WebSTAC. Cluster #1:

  1. September 2004 Water Sampling

    Office of Legacy Management (LM)

    .........5 Water Sampling Field Activities Verification ... Groundwater Quality Data Surface Water Quality Data Equipment Blank Data ...

  2. Fluid sampling tool

    DOE Patents [OSTI]

    Garcia, Anthony R.; Johnston, Roger G.; Martinez, Ronald K.

    2000-01-01

    A fluid-sampling tool for obtaining a fluid sample from a container. When used in combination with a rotatable drill, the tool bores a hole into a container wall, withdraws a fluid sample from the container, and seals the borehole. The tool collects fluid sample without exposing the operator or the environment to the fluid or to wall shavings from the container.

  3. GAMMA RAYS FROM STAR FORMATION IN CLUSTERS OF GALAXIES

    SciTech Connect (OSTI)

    Storm, Emma M.; Jeltema, Tesla E.; Profumo, Stefano

    2012-08-20

    Star formation in galaxies is observed to be associated with gamma-ray emission, presumably from non-thermal processes connected to the acceleration of cosmic-ray nuclei and electrons. The detection of gamma rays from starburst galaxies by the Fermi Large Area Telescope (LAT) has allowed the determination of a functional relationship between star formation rate and gamma-ray luminosity. Since star formation is known to scale with total infrared (8-1000 {mu}m) and radio (1.4 GHz) luminosity, the observed infrared and radio emission from a star-forming galaxy can be used to quantitatively infer the galaxy's gamma-ray luminosity. Similarly, star-forming galaxies within galaxy clusters allow us to derive lower limits on the gamma-ray emission from clusters, which have not yet been conclusively detected in gamma rays. In this study, we apply the functional relationships between gamma-ray luminosity and radio and IR luminosities of galaxies derived by the Fermi Collaboration to a sample of the best candidate galaxy clusters for detection in gamma rays in order to place lower limits on the gamma-ray emission associated with star formation in galaxy clusters. We find that several clusters have predicted gamma-ray emission from star formation that are within an order of magnitude of the upper limits derived in Ackermann et al. based on non-detection by Fermi-LAT. Given the current gamma-ray limits, star formation likely plays a significant role in the gamma-ray emission in some clusters, especially those with cool cores. We predict that both Fermi-LAT over the course of its lifetime and the future Cerenkov Telescope Array will be able to detect gamma-ray emission from star-forming galaxies in clusters.

  4. The Sample Preparation Laboratories | Sample Preparation Laboratories

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

    Cynthia Patty 1 Sam Webb 2 John Bargar 3 Arizona 4 Chemicals 5 Team Work 6 Bottles 7 Glass 8 Plan Ahead! See the tabs above for Laboratory Access and forms you'll need to complete. Equipment and Chemicals tabs detail resources already available on site. Avoid delays! Hazardous materials use may require a written Standard Operating Procedure (SOP) before you work. Check the Chemicals tab for more information. The Sample Preparation Laboratories The Sample Preparation Laboratories provide wet lab

  5. PRIMUS: Galaxy clustering as a function of luminosity and color at 0.2 < z < 1

    SciTech Connect (OSTI)

    Skibba, Ramin A.; Smith, M. Stephen M.; Coil, Alison L.; Mendez, Alexander J.; Moustakas, John; Aird, James; Blanton, Michael R.; Bray, Aaron D.; Eisenstein, Daniel J.; Cool, Richard J.; Wong, Kenneth C.; Zhu, Guangtun

    2014-04-01

    We present measurements of the luminosity and color-dependence of galaxy clustering at 0.2 < z < 1.0 in the Prism Multi-object Survey. We quantify the clustering with the redshift-space and projected two-point correlation functions, ?(r{sub p} , ?) and w{sub p} (r{sub p} ), using volume-limited samples constructed from a parent sample of over ?130, 000 galaxies with robust redshifts in seven independent fields covering 9 deg{sup 2} of sky. We quantify how the scale-dependent clustering amplitude increases with increasing luminosity and redder color, with relatively small errors over large volumes. We find that red galaxies have stronger small-scale (0.1 Mpc h {sup 1} < r{sub p} < 1 Mpc h {sup 1}) clustering and steeper correlation functions compared to blue galaxies, as well as a strong color dependent clustering within the red sequence alone. We interpret our measured clustering trends in terms of galaxy bias and obtain values of b {sub gal} ? 0.9-2.5, quantifying how galaxies are biased tracers of dark matter depending on their luminosity and color. We also interpret the color dependence with mock catalogs, and find that the clustering of blue galaxies is nearly constant with color, while redder galaxies have stronger clustering in the one-halo term due to a higher satellite galaxy fraction. In addition, we measure the evolution of the clustering strength and bias, and we do not detect statistically significant departures from passive evolution. We argue that the luminosity- and color-environment (or halo mass) relations of galaxies have not significantly evolved since z ? 1. Finally, using jackknife subsampling methods, we find that sampling fluctuations are important and that the COSMOS field is generally an outlier, due to having more overdense structures than other fields; we find that 'cosmic variance' can be a significant source of uncertainty for high-redshift clustering measurements.

  6. SPATIAL ANISOTROPY OF GALAXY KINEMATICS IN SLOAN DIGITAL SKY SURVEY GALAXY CLUSTERS

    SciTech Connect (OSTI)

    Skielboe, Andreas; Wojtak, Radoslaw; Pedersen, Kristian; Rozo, Eduardo; Rykoff, Eli S.

    2012-10-10

    Measurements of galaxy cluster kinematics are important in understanding the dynamical state and evolution of clusters of galaxies, as well as constraining cosmological models. While it is well established that clusters exhibit non-spherical geometries, evident in the distribution of galaxies on the sky, azimuthal variations of galaxy kinematics within clusters have yet to be observed. Here we measure the azimuthal dependence of the line-of-sight velocity dispersion profile in a stacked sample of 1743 galaxy clusters from the Sloan Digital Sky Survey (SDSS). The clusters are drawn from the SDSS DR8 redMaPPer catalog. We find that the line-of-sight velocity dispersion of galaxies lying along the major axis of the central galaxy is larger than those that lie along the minor axis. This is the first observational detection of anisotropic kinematics of galaxies in clusters. We show that the result is consistent with predictions from numerical simulations. Furthermore, we find that the degree of projected anisotropy is strongly dependent on the line-of-sight orientation of the galaxy cluster, opening new possibilities for assessing systematics in optical cluster finding.

  7. Rain sampling device

    DOE Patents [OSTI]

    Nelson, D.A.; Tomich, S.D.; Glover, D.W.; Allen, E.V.; Hales, J.M.; Dana, M.T.

    1991-05-14

    The present invention constitutes a rain sampling device adapted for independent operation at locations remote from the user which allows rainfall to be sampled in accordance with any schedule desired by the user. The rain sampling device includes a mechanism for directing wet precipitation into a chamber, a chamber for temporarily holding the precipitation during the process of collection, a valve mechanism for controllably releasing samples of the precipitation from the chamber, a means for distributing the samples released from the holding chamber into vessels adapted for permanently retaining these samples, and an electrical mechanism for regulating the operation of the device. 11 figures.

  8. Rain sampling device

    DOE Patents [OSTI]

    Nelson, Danny A.; Tomich, Stanley D.; Glover, Donald W.; Allen, Errol V.; Hales, Jeremy M.; Dana, Marshall T.

    1991-01-01

    The present invention constitutes a rain sampling device adapted for independent operation at locations remote from the user which allows rainfall to be sampled in accordance with any schedule desired by the user. The rain sampling device includes a mechanism for directing wet precipitation into a chamber, a chamber for temporarily holding the precipitation during the process of collection, a valve mechanism for controllably releasing samples of said precipitation from said chamber, a means for distributing the samples released from the holding chamber into vessels adapted for permanently retaining these samples, and an electrical mechanism for regulating the operation of the device.

  9. THE ACS FORNAX CLUSTER SURVEY. VI. THE NUCLEI OF EARLY-TYPE GALAXIES IN THE FORNAX CLUSTER

    SciTech Connect (OSTI)

    Turner, Monica L.; Cote, Patrick; Ferrarese, Laura; Blakeslee, John P.; Jordan, Andres; Mei, Simona; Peng, Eric W.; West, Michael J.

    2012-11-15

    The Advanced Camera for Surveys (ACS) Fornax Cluster Survey is a Hubble Space Telescope program to image 43 early-type galaxies in the Fornax cluster, using the F475W and F850LP bandpasses of the ACS. We employ both one-dimensional and two-dimensional techniques to characterize the properties of the stellar nuclei in these galaxies, defined as the central 'luminosity excesses', relative to a Sersic model fitted to the underlying host. We find 72% {+-} 13% of our sample (31 galaxies) to be nucleated, with only three of the nuclei offset by more than 0.''5 from their galaxy photocenter, and with the majority of nuclei having colors bluer than their hosts. The nuclei are observed to be larger, and brighter, than typical Fornax globular clusters and to follow different structural scaling relations. A comparison of our results to those from the ACS Virgo Cluster Survey reveals striking similarities in the properties of the nuclei belonging to these different environments. We briefly review a variety of proposed formation models and conclude that, for the low-mass galaxies in our sample, the most important mechanism for nucleus growth is probably infall of star clusters through dynamical friction, while for higher mass galaxies, gas accretion triggered by mergers, accretions, and tidal torques is likely to dominate, with the relative importance of these two processes varying smoothly as a function of galaxy mass. Some intermediate-mass galaxies in our sample show a complexity in their inner structure that may be the signature of the 'hybrid nuclei' that arose through parallel formation channels.

  10. Cool Core Bias in Sunyaev-Zel’dovich Galaxy Cluster Surveys

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

    Lin, Henry W.; McDonald, Michael; Benson, Bradford; Miller, Eric

    2015-03-18

    Sunyaev-Zeldovich (SZ) surveys find massive clusters of galaxies by measuring the inverse Compton scattering of cosmic microwave background off of intra-cluster gas. The cluster selection function from such surveys is expected to be nearly independent of redshift and cluster astrophysics. In this work, we estimate the effect on the observed SZ signal of centrally-peaked gas density profiles (cool cores) and radio emission from the brightest cluster galaxy (BCG) by creating mock observations of a sample of clusters that span the observed range of classical cooling rates and radio luminosities. For each cluster, we make simulated SZ observations by the Southmore » Pole Telescope and characterize the cluster selection function, but note that our results are broadly applicable to other SZ surveys. We find that the inclusion of a cool core can cause a change in the measured SPT significance of a cluster between 0.01%–10% at z > 0.3, increasing with cuspiness of the cool core and angular size on the sky of the cluster (i.e., decreasing redshift, increasing mass). We provide quantitative estimates of the bias in the SZ signal as a function of a gas density cuspiness parameter, redshift, mass, and the 1.4 GHz radio luminosity of the central AGN. Based on this work, we estimate that, for the Phoenix cluster (one of the strongest cool cores known), the presence of a cool core is biasing the SZ significance high by ~6%. The ubiquity of radio galaxies at the centers of cool core clusters will offset the cool core bias to varying degrees« less

  11. Water and Sediment Sampling

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

    MDC Blank 7222014 Below MDC Below MDC Water Sampling Results Location Sample Date WIPP ... Tut Tank 3132014 Below MDC Below MDC Fresh Water Tank 3122014 Below MDC Below MDC Hill ...

  12. September 2004 Water Sampling

    Office of Legacy Management (LM)

    ... 100, 17B, 1A, 72, and 81 were classified as Category II. The sample results were qualified with a "Q" flag, indicating the data are qualitative because of the sampling technique. ...

  13. September 2004 Water Sampling

    Office of Legacy Management (LM)

    ... the applicable MDL. Inductively Coupled Plasma Interference Check Sample Analysis ... and background correction factors for all inductively coupled plasma instruments. ...

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    Office of Legacy Management (LM)

    .........7 Water Sampling Field Activities Verification ... Groundwater Quality Data Static Water Level Data Time-Concentration Graphs ...

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    Office of Legacy Management (LM)

    .........9 Water Sampling Field Activities Verification ... Data Durango Processing Site Surface Water Quality Data Equipment Blank Data Static ...

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    Office of Legacy Management (LM)

    .........3 Water Sampling Field Activities Verification ... Groundwater Quality Data Surface Water Quality Data Natural Gas Analysis Data ...

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    Office of Legacy Management (LM)

    .........5 Water Sampling Field Activities Verification ... Groundwater Quality Data Static Water Level Data Hydrographs Time-Concentration ...

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    Office of Legacy Management (LM)

    .........5 Water Sampling Field Activities Verification ... Groundwater Quality Data Static Water Level Data Hydrograph Time-Concentration ...

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    Office of Legacy Management (LM)

    .........5 Water Sampling Field Activities Verification ... Groundwater Quality Data Surface Water Quality Data Time-Concentration Graph ...

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    Office of Legacy Management (LM)

    .........5 Water Sampling Field Activities Verification ... Quality Data Equipment Blank Data Static Water Level Data Time-Concentration Graphs ...

  1. September 2004 Water Sampling

    Office of Legacy Management (LM)

    .........5 Water Sampling Field Activities Verification ... Groundwater Quality Data Static Water Level Data Time-Concentration Graphs ...

  2. September 2004 Water Sampling

    Office of Legacy Management (LM)

    .........9 Water Sampling Field Activities Verification ... Groundwater Quality Data Surface Water Quality Data Static Water Level Data ...

  3. September 2004 Water Sampling

    Office of Legacy Management (LM)

    .........3 Water Sampling Field Activities Verification ... Groundwater Quality Data Surface Water Quality Data Time-Concentration Graphs ...

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    .........7 Water Sampling Field Activities Verification ... Groundwater Quality Data Surface Water Quality Data Equipment Blank Data Static ...

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    .........5 Water Sampling Field Activities Verification ... Groundwater Quality Data Surface Water Quality Data Equipment Blank Data Static ...

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    Office of Legacy Management (LM)

    Water Sampling at the Ambrosia Lake, New Mexico, Disposal Site February 2015 LMS/AMB/S01114 This page intentionally left blank U.S. Department of Energy DVP-November 2014, Ambrosia Lake, New Mexico February 2015 RIN 14116607 Page i Contents Sampling Event Summary ...............................................................................................................1 Ambrosia Lake, NM, Disposal Site Planned Sampling Map...........................................................3 Data

  7. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Sampling at the Ambrosia Lake, New Mexico, Disposal Site March 2016 LMS/AMB/S01215 This page intentionally left blank U.S. Department of Energy DVP-December 2015, Ambrosia Lake, New Mexico March 2016 RIN 15117494 Page i Contents Sampling Event Summary ...............................................................................................................1 Ambrosia Lake, NM, Disposal Site Planned Sampling Map...........................................................3 Data Assessment

  8. September 2004 Water Sampling

    Office of Legacy Management (LM)

    October 2013 Groundwater Sampling at the Bluewater, New Mexico, Disposal Site December 2013 LMS/BLU/S00813 This page intentionally left blank U.S. Department of Energy DVP-August and October 2013, Bluewater, New Mexico December 2013 RIN 13085537 and 13095651 Page i Contents Sampling Event Summary ...............................................................................................................1 Private Wells Sampled August 2013 and October 2013, Bluewater, NM, Disposal Site

  9. September 2004 Water Sampling

    Office of Legacy Management (LM)

    and Surface Water Sampling at the Monument Valley, Arizona, Processing Site February 2015 LMS/MON/S01214 This page intentionally left blank U.S. Department of Energy DVP-December 2014, Monument Valley, Arizona February 2015 RIN 14126645 Page i Contents Sampling Event Summary ...............................................................................................................1 Monument Valley, Arizona, Disposal Site Sample Location Map ..................................................5

  10. September 2004 Water Sampling

    Office of Legacy Management (LM)

    4 Alternate Water Supply System Sampling at the Riverton, Wyoming, Processing Site May 2014 LMS/RVT/S00314 This page intentionally left blank U.S. Department of Energy DVP-March 2014, Riverton, Wyoming May 2014 RIN 14035986 Page i Contents Sampling Event Summary ...............................................................................................................1 Riverton, WY, Processing Site, Sample Location Map ...................................................................3 Data

  11. September 2004 Water Sampling

    Office of Legacy Management (LM)

    February 2015 Groundwater and Surface Water Sampling at the Grand Junction, Colorado, Site April 2015 LMS/GJO/S00215 This page intentionally left blank U.S. Department of Energy DVP-February 2015, Grand Junction, Colorado, Site April 2015 RIN 15026795 Page i Contents Sampling Event Summary ...............................................................................................................1 Grand Junction, Colorado, Site Sample Location Map

  12. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Sampling at the Grand Junction, Colorado, Disposal Site November 2013 LMS/GRJ/S00813 This page intentionally left blank U.S. Department of Energy DVP-August 2013, Grand Junction, Colorado November 2013 RIN 13075515 Page i Contents Sampling Event Summary ...............................................................................................................1 Grand Junction, Colorado, Disposal Site Sample Location Map ....................................................3 Data Assessment

  13. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Old and New Rifle, Colorado, Processing Sites August 2013 LMS/RFN/RFO/S00613 This page intentionally left blank U.S. Department of Energy DVP-June 2013, Rifle, Colorado August 2013 RIN 13065380 Page i Contents Sampling Event Summary ...............................................................................................................1 Sample Location Map, New Rifle, Colorado, Processing Site ........................................................5 Sample Location Map, Old Rifle,

  14. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Groundwater and Surface Water Sampling at the Slick Rock East and West, Colorado, Processing Sites November 2013 LMS/SRE/SRW/S0913 This page intentionally left blank U.S. Department of Energy DVP-September 2013, Slick Rock, Colorado November 2013 RIN 13095593 Page i Contents Sampling Event Summary ...............................................................................................................1 Slick Rock East and West, Colorado, Processing Sites, Sample Location Map

  15. Aerosol sampling system

    DOE Patents [OSTI]

    Masquelier, Donald A.

    2004-02-10

    A system for sampling air and collecting particulate of a predetermined particle size range. A low pass section has an opening of a preselected size for gathering the air but excluding particles larger than the sample particles. An impactor section is connected to the low pass section and separates the air flow into a bypass air flow that does not contain the sample particles and a product air flow that does contain the sample particles. A wetted-wall cyclone collector, connected to the impactor section, receives the product air flow and traps the sample particles in a liquid.

  16. CN ANOMALIES IN THE HALO SYSTEM AND THE ORIGIN OF GLOBULAR CLUSTERS IN THE MILKY WAY

    SciTech Connect (OSTI)

    Carollo, Daniela; Martell, Sarah L.; Beers, Timothy C.; Freeman, Ken C. E-mail: smartell@aao.gov.au E-mail: kcf@mso.anu.edu.au

    2013-06-01

    We explore the kinematics and orbital properties of a sample of red giants in the halo system of the Milky Way that are thought to have formed in globular clusters based on their anomalously strong UV/blue CN bands. The orbital parameters of the CN-strong halo stars are compared to those of the inner- and outer-halo populations as described by Carollo et al., and to the orbital parameters of globular clusters with well-studied Galactic orbits. The CN-strong field stars and the globular clusters both exhibit kinematics and orbital properties similar to the inner-halo population, indicating that stripped or destroyed globular clusters could be a significant source of inner-halo field stars, and suggesting that both the CN-strong stars and the majority of globular clusters are primarily associated with this population.

  17. QUASAR-GALAXY CLUSTERING THROUGH PROJECTED GALAXY COUNTS AT z = 0.6-1.2

    SciTech Connect (OSTI)

    Zhang Shaohua; Zhou Hongyan; Wang Tinggui; Wang Huiyuan E-mail: twang@ustc.edu.cn

    2013-08-20

    We investigate the spatial clustering of galaxies around quasars at z = 0.6-1.2 using photometric data from Sloan Digital Sky Survey Stripe 82. The quasar and galaxy cross-correlation functions are measured through the projected galaxy number density n(r{sub p} ) on scales of 0.05 < r{sub p} < 20 h {sup -1} Mpc around quasars for a sample of 2300 quasars from Schneider et al. We detect strong clustering signals at all redshifts and find that the clustering amplitude increases significantly with redshift. We examine the dependence of quasar-galaxy clustering on quasar and galaxy properties and find that the clustering amplitude is significantly larger for quasars with more massive black holes or with bluer colors, while there is no dependence on quasar luminosity. We also show that quasars have a stronger correlation amplitude with blue galaxies than with red galaxies. We finally discuss the implications of our findings.

  18. Sample Proficiency Test exercise

    SciTech Connect (OSTI)

    Alcaraz, A; Gregg, H; Koester, C

    2006-02-05

    The current format of the OPCW proficiency tests has multiple sets of 2 samples sent to an analysis laboratory. In each sample set, one is identified as a sample, the other as a blank. This method of conducting proficiency tests differs from how an OPCW designated laboratory would receive authentic samples (a set of three containers, each not identified, consisting of the authentic sample, a control sample, and a blank sample). This exercise was designed to test the reporting if the proficiency tests were to be conducted. As such, this is not an official OPCW proficiency test, and the attached report is one method by which LLNL might report their analyses under a more realistic testing scheme. Therefore, the title on the report ''Report of the Umpteenth Official OPCW Proficiency Test'' is meaningless, and provides a bit of whimsy for the analyses and readers of the report.

  19. Completion Report for Well Cluster ER-5-4

    SciTech Connect (OSTI)

    U.S. Department of Energy, National Nuclear Security Administration, Nevada Site Office; Bechtel Nevada

    2005-02-01

    Well Cluster ER-5-4 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. The cluster consists of two wells, positioned about 30 meters apart on the same drill pad, constructed as part of a hydrogeologic investigation program for Frenchman Flat at the Nevada Test Site. Detailed lithologic descriptions with preliminary stratigraphic assignments for the well cluster are included in this report. These are based on composite drill cuttings collected every 3 meters, and 156 sidewall samples taken at various depths below 192 meters in both boreholes, supplemented by geophysical log data. Detailed petrographic, chemical, and mineralogical studies of rock samples were conducted on 122 samples. Well ER-5-4 penetrated approximately 1,120 meters of Quaternary and Tertiary alluvium before reaching total depth in Tertiary volcanic rocks at 1,137.5 meters. The deeper Well ER-5-4 No.2 penetrated 1,120.4 meters of alluvial sediments, and was terminated within Tertiary volcanic rocks at a depth of 2,133.6 meters, indicating that Paleozoic rocks are deeper than expected at this site.

  20. Quantum Monte Carlo methods and lithium cluster properties

    SciTech Connect (OSTI)

    Owen, R.K.

    1990-12-01

    Properties of small lithium clusters with sizes ranging from n = 1 to 5 atoms were investigated using quantum Monte Carlo (QMC) methods. Cluster geometries were found from complete active space self consistent field (CASSCF) calculations. A detailed development of the QMC method leading to the variational QMC (V-QMC) and diffusion QMC (D-QMC) methods is shown. The many-body aspect of electron correlation is introduced into the QMC importance sampling electron-electron correlation functions by using density dependent parameters, and are shown to increase the amount of correlation energy obtained in V-QMC calculations. A detailed analysis of D-QMC time-step bias is made and is found to be at least linear with respect to the time-step. The D-QMC calculations determined the lithium cluster ionization potentials to be 0.1982(14) [0.1981], 0.1895(9) [0.1874(4)], 0.1530(34) [0.1599(73)], 0.1664(37) [0.1724(110)], 0.1613(43) [0.1675(110)] Hartrees for lithium clusters n = 1 through 5, respectively; in good agreement with experimental results shown in the brackets. Also, the binding energies per atom was computed to be 0.0177(8) [0.0203(12)], 0.0188(10) [0.0220(21)], 0.0247(8) [0.0310(12)], 0.0253(8) [0.0351(8)] Hartrees for lithium clusters n = 2 through 5, respectively. The lithium cluster one-electron density is shown to have charge concentrations corresponding to nonnuclear attractors. The overall shape of the electronic charge density also bears a remarkable similarity with the anisotropic harmonic oscillator model shape for the given number of valence electrons.

  1. Pair extended coupled cluster doubles

    SciTech Connect (OSTI)

    Henderson, Thomas M.; Scuseria, Gustavo E.; Bulik, Ireneusz W.

    2015-06-07

    The accurate and efficient description of strongly correlated systems remains an important challenge for computational methods. Doubly occupied configuration interaction (DOCI), in which all electrons are paired and no correlations which break these pairs are permitted, can in many cases provide an accurate account of strong correlations, albeit at combinatorial computational cost. Recently, there has been significant interest in a method we refer to as pair coupled cluster doubles (pCCD), a variant of coupled cluster doubles in which the electrons are paired. This is simply because pCCD provides energies nearly identical to those of DOCI, but at mean-field computational cost (disregarding the cost of the two-electron integral transformation). Here, we introduce the more complete pair extended coupled cluster doubles (pECCD) approach which, like pCCD, has mean-field cost and reproduces DOCI energetically. We show that unlike pCCD, pECCD also reproduces the DOCI wave function with high accuracy. Moreover, pECCD yields sensible albeit inexact results even for attractive interactions where pCCD breaks down.

  2. September 2004 Water Sampling

    Office of Legacy Management (LM)

    and September 2013 Groundwater and Surface Water Sampling at the Durango, Colorado, Disposal and Processing Sites March 2014 LMS/DUD/DUP/S00613 This page intentionally left blank U.S. Department of Energy DVP-June and September 2013, Durango, Colorado March 2014 RIN 13055370 and 13085577 Page i Contents Sampling Event Summary ...............................................................................................................1 Durango, Colorado, Disposal Site Sample Location Map-June

  3. September 2004 Water Sampling

    Office of Legacy Management (LM)

    ... The gross alpha, gross beta, radium-226, and radium-228 method blank results were below the DLC. Inductively Coupled Plasma (ICP) Interference Check Sample (ICS) Analysis ICP ...

  4. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Groundwater, Surface Water, and Alternate Water Supply System Sampling at the Riverton, Wyoming, Processing Site December 2013 LMSRVTS00913 This page intentionally left blank ...

  5. Hydrodynamic simulation of non-thermal pressure profiles of galaxy clusters

    SciTech Connect (OSTI)

    Nelson, Kaylea; Nagai, Daisuke; Lau, Erwin T.

    2014-09-01

    Cosmological constraints from X-ray and microwave observations of galaxy clusters are subjected to systematic uncertainties. Non-thermal pressure support due to internal gas motions in galaxy clusters is one of the major sources of astrophysical uncertainties. Using a mass-limited sample of galaxy clusters from a high-resolution hydrodynamical cosmological simulation, we characterize the non-thermal pressure fraction profile and study its dependence on redshift, mass, and mass accretion rate. We find that the non-thermal pressure fraction profile is universal across redshift when galaxy cluster radii are defined with respect to the mean matter density of the universe instead of the commonly used critical density. We also find that the non-thermal pressure is predominantly radial, and the gas velocity anisotropy profile exhibits strong universality when galaxy cluster radii are defined with respect to the mean matter density of the universe. However, we find that the non-thermal pressure fraction is strongly dependent on the mass accretion rate of the galaxy cluster. We provide fitting formulae for the universal non-thermal pressure fraction and velocity anisotropy profiles of gas in galaxy clusters, which should be useful in modeling astrophysical uncertainties pertinent to using galaxy clusters as cosmological probes.

  6. The L_X-M relation of Clusters of Galaxies

    SciTech Connect (OSTI)

    Rykoff, E.S.; Evrard, A.E.; McKay, T.A.; Becker, M.R.; Johnston, D.E.; Koester, B.P.; Nord, B.; Rozo, E.; Sheldon, E.S.; Stanek, R.; Wechsler, R.H.

    2008-05-16

    We present a new measurement of the scaling relation between X-ray luminosity and total mass for 17,000 galaxy clusters in the maxBCG cluster sample. Stacking sub-samples within fixed ranges of optical richness, N200, we measure the mean 0.1-2.4 keV X-ray luminosity, , from the ROSAT All-Sky Survey. The mean mass, , is measured from weak gravitational lensing of SDSS background galaxies (Johnston et al. 2007). For 9 {le} N{sub 200} < 200, the data are well fit by a power-law, /10{sup 42} h{sup -2} ergs{sup -1} = (12.6{sub -1.3}{sup +1.4}(stat) {+-} 1.6 (sys)) (/10{sup 14} h{sup -1} M{sub {circle_dot}}){sup 1.65{+-}0.13}. The slope agrees to within 10% with previous estimates based on X-ray selected catalogs, implying that the covariance in L{sub X} and N{sub 200} at fixed halo mass is not large. The luminosity intercept is 30%, or 2{sigma}, lower than determined from the X-ray flux-limited sample of Reiprich & Boehringer (2002), assuming hydrostatic equilibrium. This slight difference could arise from a combination of Malmquist bias and/or systematic error in hydrostatic mass estimates, both of which are expected. The intercept agrees with that derived by Stanek et al. (2006) using a model for the statistical correspondence between clusters and halos in a WMAP3 cosmology with power spectrum normalization {sigma}{sub 8} = 0.85. Similar exercises applied to future data sets will allow constraints on the covariance among optical and hot gas properties of clusters at fixed mass.

  7. Creating Sample Plans

    Energy Science and Technology Software Center (OSTI)

    1999-03-24

    The program has been designed to increase the accuracy and reduce the preparation time for completing sampling plans. It consists of our files 1. Analyte/Combination (AnalCombo) A list of analytes and combinations of analytes that can be requested of the onsite and offsite labs. Whenever a specific combination of analytes or suite names appear on the same line as the code number, this indicates that one sample can be placed in one bottle to bemore » analyzed for these paremeters. A code number is assigned for each analyte and combination of analytes. 2. Sampling Plans Database (SPDb) A database that contains all of the analytes and combinations of analytes along with the basic information required for preparing a sample plan. That basic information includes the following fields; matrix, hold time, preservation, sample volume, container size, if the bottle caps are taped, acceptable choices. 3. Sampling plans create (SPcreate) a file that will lookup information from the Sampling Plans Database and the Job Log File (JLF98) A major database used by Sample Managemnet Services for recording more than 100 fields of information.« less

  8. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Bluewater, New Mexico, Disposal Site February 2014 LMS/BLU/S01113 This page intentionally left blank U.S. Department of Energy DVP-November 2013, Bluewater, New Mexico February 2014 RIN 13115746 Page i Contents Sampling Event Summary ...............................................................................................................1 Bluewater, New Mexico, Disposal Site Sample Location Map.......................................................5 Data Assessment Summary

  9. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Burrell, Pennsylvania, Disposal Site January 2014 LMS/BUR/S01113 This page intentionally left blank U.S. Department of Energy DVP-November 2013, Burrell, Pennsylvania January 2014 RIN 13095638 Page i Contents Sampling Event Summary ...............................................................................................................1 Burrell, Pennsylvania, Disposal Site, Sample Location Map ..........................................................3 Data Assessment Summary

  10. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Canonsburg, Pennsylvania, Disposal Site February 2014 LMS/CAN/S01113 This page intentionally left blank U.S. Department of Energy DVP-November 2013, Canonsburg, Pennsylvania February 2014 RIN 13095639 Page i Contents Sampling Event Summary ...............................................................................................................1 Canonsburg, Pennsylvania, Disposal Site, Sample Location Map ..................................................3 Data Assessment Summary

  11. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Green River, Utah, Disposal Site August 2013 LMS/GRN/S00613 This page intentionally left blank U.S. Department of Energy DVP-June 2013, Green River, Utah August 2013 RIN 13065402 Page i Contents Sampling Event Summary ...............................................................................................................1 Data Assessment Summary ..............................................................................................................7 Water Sampling Field Activities

  12. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Disposal Site August 2014 LMS/LKD/S00514 This page intentionally left blank U.S. Department of Energy DVP-May 2014, Lakeview, Oregon, Disposal August 2014 RIN 14056157 Page i Contents Sampling Event Summary ...............................................................................................................1 Lakeview, Oregon, Disposal Site, Sample Location Map ...............................................................3 Data Assessment Summary

  13. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Processing Site August 2014 LMS/LKP/S00514 This page intentionally left blank U.S. Department of Energy DVP-May 2014, Lakeview, Oregon, Processing August 2014 RIN 14056157 and 14056158 Page i Contents Sampling Event Summary ...............................................................................................................1 Lakeview, Oregon, Processing Site, Sample Location Map ............................................................3 Data Assessment Summary

  14. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Riverton, Wyoming, Processing Site September 2013 LMS/RVT/S00613 This page intentionally left blank U.S. Department of Energy DVP-June 2013, Riverton, Wyoming September 2013 RIN 13065379 Page i Contents Sampling Event Summary ...............................................................................................................1 Riverton, Wyoming, Processing Site, Sample Location Map .........................................................5 Data Assessment Summary

  15. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Riverton, Wyoming, Processing Site February 2016 LMS/RVT/S00915 This page intentionally left blank U.S. Department of Energy DVP-September 2015, Riverton, Wyoming February 2016 RINs 15097345, 15097346, and 15097347 Page i Contents Sampling Event Summary ...............................................................................................................1 Riverton, Wyoming, Processing Site Planned Sampling Location Map .........................................7 Data Assessment Summary

  16. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Rifle, Colorado, New and Old Processing Sites January 2014 LMS/RFN/RFO/S01113 This page intentionally left blank U.S. Department of Energy DVP-November 2013, Rifle, Colorado January 2014 RIN 13115731 Page i Contents Sampling Event Summary ...............................................................................................................1 New Rifle, Colorado, Processing Site, Sample Location Map ........................................................5 Old Rifle, Colorado, Processing

  17. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Old and New Rifle, Colorado, Processing Sites January 2015 LMS/RFN/RFO/S01114 This page intentionally left blank U.S. Department of Energy DVP-November 2014, Rifle, Colorado January 2015 RINs 14106568 and 14106569 Page i Contents Sampling Event Summary ...............................................................................................................1 New Rifle, Colorado, Processing Site, Planned Sampling Map ......................................................3 Old Rifle,

  18. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Slick Rock, Colorado, Processing Sites January 2016 LMS/SRE/SRW/S00915 This page intentionally left blank U.S. Department of Energy DVP-September 2015, Slick Rock, Colorado January 2016 RINs 15087319 and 15107424 Page i Contents Sampling Event Summary ...............................................................................................................1 Slick Rock, Colorado, Processing Sites, Sample Location Map .....................................................5 Data Assessment

  19. Sampling system and method

    DOE Patents [OSTI]

    Decker, David L.; Lyles, Brad F.; Purcell, Richard G.; Hershey, Ronald Lee

    2013-04-16

    The present disclosure provides an apparatus and method for coupling conduit segments together. A first pump obtains a sample and transmits it through a first conduit to a reservoir accessible by a second pump. The second pump further conducts the sample from the reservoir through a second conduit.

  20. Adaptive Sampling Proxy Application

    Energy Science and Technology Software Center (OSTI)

    2012-10-22

    ASPA is an implementation of an adaptive sampling algorithm [1-3], which is used to reduce the computational expense of computer simulations that couple disparate physical scales. The purpose of ASPA is to encapsulate the algorithms required for adaptive sampling independently from any specific application, so that alternative algorithms and programming models for exascale computers can be investigated more easily.

  1. Biological sample collector

    DOE Patents [OSTI]

    Murphy, Gloria A.

    2010-09-07

    A biological sample collector is adapted to a collect several biological samples in a plurality of filter wells. A biological sample collector may comprise a manifold plate for mounting a filter plate thereon, the filter plate having a plurality of filter wells therein; a hollow slider for engaging and positioning a tube that slides therethrough; and a slide case within which the hollow slider travels to allow the tube to be aligned with a selected filter well of the plurality of filter wells, wherein when the tube is aligned with the selected filter well, the tube is pushed through the hollow slider and into the selected filter well to sealingly engage the selected filter well and to allow the tube to deposit a biological sample onto a filter in the bottom of the selected filter well. The biological sample collector may be portable.

  2. CANDIDATE CLUSTERS OF GALAXIES AT z > 1.3 IDENTIFIED IN THE SPITZER SOUTH POLE TELESCOPE DEEP FIELD SURVEY

    SciTech Connect (OSTI)

    Rettura, A.; Stern, D.; Martinez-Manso, J.; Gettings, D.; Gonzalez, A. H.; Mei, S.; Ashby, M. L. N.; Brodwin, M.; Stanford, S. A.; Bartlett, J. G.

    2014-12-20

    We present 279 galaxy cluster candidates at z > 1.3 selected from the 94 deg{sup 2} Spitzer South Pole Telescope Deep Field (SSDF) survey. We use a simple algorithm to select candidate high-redshift clusters of galaxies based on Spitzer/IRAC mid-infrared data combined with shallow all-sky optical data. We identify distant cluster candidates adopting an overdensity threshold that results in a high purity (80%) cluster sample based on tests in the Spitzer Deep, Wide-Field Survey of the Boötes field. Our simple algorithm detects all three 1.4 < z ≤ 1.75 X-ray detected clusters in the Boötes field. The uniqueness of the SSDF survey resides not just in its area, one of the largest contiguous extragalactic fields observed with Spitzer, but also in its deep, multi-wavelength coverage by the South Pole Telescope (SPT), Herschel/SPIRE, and XMM-Newton. This rich data set will allow direct or stacked measurements of Sunyaev-Zel'dovich effect decrements or X-ray masses for many of the SSDF clusters presented here, and enable a systematic study of the most distant clusters on an unprecedented scale. We measure the angular correlation function of our sample and find that these candidates show strong clustering. Employing the COSMOS/UltraVista photometric catalog in order to infer the redshift distribution of our cluster selection, we find that these clusters have a comoving number density n{sub c}=(0.7{sub −0.6}{sup +6.3})×10{sup −7} h{sup 3} Mpc{sup −3} and a spatial clustering correlation scale length r {sub 0} = (32 ± 7) h {sup –1} Mpc. Assuming our sample is comprised of dark matter halos above a characteristic minimum mass, M {sub min}, we derive that at z = 1.5 these clusters reside in halos larger than M{sub min}=1.5{sub −0.7}{sup +0.9}×10{sup 14} h{sup −1} M{sub ⊙}. We find that the mean mass of our cluster sample is equal to M{sub mean}=1.9{sub −0.8}{sup +1.0}×10{sup 14} h{sup −1} M{sub ⊙}; thus, our sample contains the progenitors of

  3. September 2004 Water Sampling

    Office of Legacy Management (LM)

    ... 10 pCiL Liquid Scintillation LMR-15 Uranium Vanadium Zinc Total No. of Analytes 4 0 ... 26, 2013 TO: Rick Findlay FROM: Jeff Price SUBJECT: Trip Report (LTHMP Sampling) ...

  4. Water Sample Concentrator

    ScienceCinema (OSTI)

    Idaho National Laboratory

    2010-01-08

    Automated portable device that concentrates and packages a sample of suspected contaminated water for safe, efficient transport to a qualified analytical laboratory. This technology will help safeguard against pathogen contamination or chemical and biolog

  5. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Groundwater, Surface Water, Produced Water, and Natural Gas Sampling at the Gasbuggy, New Mexico, Site October 2014 LMSGSBS00614 Available for sale to the public from: U.S. ...

  6. Dissolution actuated sample container

    DOE Patents [OSTI]

    Nance, Thomas A.; McCoy, Frank T.

    2013-03-26

    A sample collection vial and process of using a vial is provided. The sample collection vial has an opening secured by a dissolvable plug. When dissolved, liquids may enter into the interior of the collection vial passing along one or more edges of a dissolvable blocking member. As the blocking member is dissolved, a spring actuated closure is directed towards the opening of the vial which, when engaged, secures the vial contents against loss or contamination.

  7. SAMPLING AND ANALYSIS PROTOCOLS

    SciTech Connect (OSTI)

    Jannik, T; P Fledderman, P

    2007-02-09

    Radiological sampling and analyses are performed to collect data for a variety of specific reasons covering a wide range of projects. These activities include: Effluent monitoring; Environmental surveillance; Emergency response; Routine ambient monitoring; Background assessments; Nuclear license termination; Remediation; Deactivation and decommissioning (D&D); and Waste management. In this chapter, effluent monitoring and environmental surveillance programs at nuclear operating facilities and radiological sampling and analysis plans for remediation and D&D activities will be discussed.

  8. Liquid sampling system

    DOE Patents [OSTI]

    Larson, L.L.

    1984-09-17

    A conduit extends from a reservoir through a sampling station and back to the reservoir in a closed loop. A jet ejector in the conduit establishes suction for withdrawing liquid from the reservoir. The conduit has a self-healing septum therein upstream of the jet ejector for receiving one end of a double-ended cannula, the other end of which is received in a serum bottle for sample collection. Gas is introduced into the conduit at a gas bleed between the sample collection bottle and the reservoir. The jet ejector evacuates gas from the conduit and the bottle and aspirates a column of liquid from the reservoir at a high rate. When the withdrawn liquid reaches the jet ejector the rate of flow therethrough reduces substantially and the gas bleed increases the pressure in the conduit for driving liquid into the sample bottle, the gas bleed forming a column of gas behind the withdrawn liquid column and interrupting the withdrawal of liquid from the reservoir. In the case of hazardous and toxic liquids, the sample bottle and the jet ejector may be isolated from the reservoir and may be further isolated from a control station containing remote manipulation means for the sample bottle and control valves for the jet ejector and gas bleed. 5 figs.

  9. Liquid sampling system

    DOE Patents [OSTI]

    Larson, Loren L.

    1987-01-01

    A conduit extends from a reservoir through a sampling station and back to the reservoir in a closed loop. A jet ejector in the conduit establishes suction for withdrawing liquid from the reservoir. The conduit has a self-healing septum therein upstream of the jet ejector for receiving one end of a double-ended cannula, the other end of which is received in a serum bottle for sample collection. Gas is introduced into the conduit at a gas bleed between the sample collection bottle and the reservoir. The jet ejector evacuates gas from the conduit and the bottle and aspirates a column of liquid from the reservoir at a high rate. When the withdrawn liquid reaches the jet ejector the rate of flow therethrough reduces substantially and the gas bleed increases the pressure in the conduit for driving liquid into the sample bottle, the gas bleed forming a column of gas behind the withdrawn liquid column and interrupting the withdrawal of liquid from the reservoir. In the case of hazardous and toxic liquids, the sample bottle and the jet ejector may be isolated from the reservoir and may be further isolated from a control station containing remote manipulation means for the sample bottle and control valves for the jet ejector and gas bleed.

  10. Toward understanding environmental effects in SDSS clusters

    SciTech Connect (OSTI)

    Einasto, Jaan; Tago, E.; Einasto, M.; Saar, E.; Suhhonenko, I.; Heinamaki, P.; Hutsi, G.; Tucker, D.L.; /Fermilab

    2004-11-01

    We find clusters and superclusters of galaxies using the Data Release 1 of the Sloan Digital Sky Survey. We determine the luminosity function of clusters and find that clusters in a high-density environment have a luminosity a factor of {approx}5 higher than in a low-density environment. We also study clusters and superclusters in numerical simulations. Simulated clusters in a high-density environment are also more massive than those in a low-density environment. Comparison of the density distribution at various epochs in simulations shows that in large low-density regions (voids) dynamical evolution is very slow and stops at an early epoch. In contrast, in large regions of higher density (superclusters) dynamical evolution starts early and continues until the present; here particles cluster early, and by merging of smaller groups very rich systems of galaxies form.

  11. Optimal sampling efficiency in Monte Carlo sampling with an approximat...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Optimal sampling efficiency in Monte Carlo sampling with an approximate potential Citation Details In-Document Search Title: Optimal sampling efficiency in Monte ...

  12. JLab Cluster Tops 100 Teraflops | Jefferson Lab

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

    Cluster Tops 100 Teraflops JLab Cluster Tops 100 Teraflops NEWPORT NEWS, VA, Oct. 14 - The fastest computer system in Hampton Roads has booted up with more than 100 Teraflops of processing power. Located at the Department of Energy's Thomas Jefferson National Accelerator Facility, the cluster computer system was recently upgraded with video game components to assist scientists in modeling the smallest bits of matter in the universe. "Our resources crossed 100 Teraflops of sustained

  13. Multiphoton ionization of large water clusters

    SciTech Connect (OSTI)

    Apicella, B.; Li, X.; Passaro, M.; Spinelli, N.; Wang, X.

    2014-05-28

    Water clusters are multimers of water molecules held together by hydrogen bonds. In the present work, multiphoton ionization in the UV range coupled with time of flight mass spectrometry has been applied to water clusters with up to 160 molecules in order to obtain information on the electronic states of clusters of different sizes up to dimensions that can approximate the bulk phase. The dependence of ion intensities of water clusters and their metastable fragments produced by laser ionization at 355 nm on laser power density indicates a (3+1)-photon resonance-enhanced multiphoton ionization process. It also explains the large increase of ionization efficiency at 355 nm compared to that at 266 nm. Indeed, it was found, by applying both nanosecond and picosecond laser ionization with the two different UV wavelengths, that no water cluster sequences after n = 9 could be observed at 266 nm, whereas water clusters up to m/z 2000 Th in reflectron mode and m/z 3000 Th in linear mode were detected at 355 nm. The agreement between our findings on clusters of water, especially true in the range with n > 10, and reported data for liquid water supports the hypothesis that clusters above a critical dimension can approximate the liquid phase. It should thus be possible to study clusters just above 10 water molecules, for getting information on the bulk phase structure.

  14. Cluster Team Saffron Amanda Bonnie Zach Fuerst

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

    a Lustre Cluster Team Saffron Amanda Bonnie Zach Fuerst Thomas Stitt yaaaasss (Improving and Tracing Lustre Metadata) Overview Motivation Configuration Tracing Metadata...

  15. MCS Large Cluster Systems Software Toolkit

    Energy Science and Technology Software Center (OSTI)

    2002-11-01

    This package contains a number of systems utilities for managing a set of computers joined in a "cluster". The utilities assist a team of systems administrators in managing the cluster by automating routine tasks, centralizing information, and monitoring individual computers within the cluster. Included in the toolkit are scripts used to boot a computer from a floppy, a program to turn on and off the power to a system, and a system for using amore » database to organize cluster information.« less

  16. Fluid sampling system

    DOE Patents [OSTI]

    Houck, Edward D.

    1994-01-01

    An fluid sampling system allows sampling of radioactive liquid without spillage. A feed tank is connected to a liquid transfer jet powered by a pumping chamber pressurized by compressed air. The liquid is pumped upwardly into a sampling jet of a venturi design having a lumen with an inlet, an outlet, a constricted middle portion, and a port located above the constricted middle portion. The liquid is passed under pressure through the constricted portion causing its velocity to increase and its pressure to decreased, thereby preventing liquid from escaping. A septum sealing the port can be pierced by a two pointed hollow needle leading into a sample bottle also sealed by a pierceable septum affixed to one end. The bottle is evacuated by flow through the sample jet, cyclic variation in the sampler jet pressure periodically leaves the evacuated bottle with lower pressure than that of the port, thus causing solution to pass into the bottle. The remaining solution in the system is returned to the feed tank via a holding tank.

  17. Fluid sampling system

    DOE Patents [OSTI]

    Houck, E.D.

    1994-10-11

    An fluid sampling system allows sampling of radioactive liquid without spillage. A feed tank is connected to a liquid transfer jet powered by a pumping chamber pressurized by compressed air. The liquid is pumped upwardly into a sampling jet of a venturi design having a lumen with an inlet, an outlet, a constricted middle portion, and a port located above the constricted middle portion. The liquid is passed under pressure through the constricted portion causing its velocity to increase and its pressure to be decreased, thereby preventing liquid from escaping. A septum sealing the port can be pierced by a two pointed hollow needle leading into a sample bottle also sealed by a pierceable septum affixed to one end. The bottle is evacuated by flow through the sample jet, cyclic variation in the sampler jet pressure periodically leaves the evacuated bottle with lower pressure than that of the port, thus causing solution to pass into the bottle. The remaining solution in the system is returned to the feed tank via a holding tank. 4 figs.

  18. Visual Sample Plan

    Energy Science and Technology Software Center (OSTI)

    2007-10-25

    VSP selects the appropriate number and location of environmental samples to ensure that the results of statistical tests performed to provide input to risk decisions have the required confidence and performance. VSP Version 5.0 provides sample-size equations or algorithms needed by specific statistical tests appropriate for specific environmental sampling objectives. It also provides data quality assessment and statistical analysis functions to support evaluation of the data and determine whether the data support decisions regarding sitesmore » suspected of contamination. The easy-to-use program is highly visual and graphic. VSP runs on personal computers with Microsoft Windows operating systems (98, NT, 2000, Millennium Edition, CE, and XP) Designed primarily for project managers and users without expertise in statistics, VSP is applicable to two- and three-dimensional populations to be sampled (e.g., rooms and buildings, surface soil, a defined layer of subsurface soil, water bodies, and other similar applications) for studies of environmental quality. VSP is also applicable for designing sampling plans for assessing chem./rad/bio threat and hazard identification within rooms and buildings, and for designing geophysical surveys for UXO identification.« less

  19. Spectral energy distributions and masses of 304 M31 old star clusters

    SciTech Connect (OSTI)

    Ma, Jun; Wang, Song; Wu, Zhenyu; Zhang, Tianmeng; Zou, Hu; Nie, Jun dan; Zhou, Zhiming; Zhou, Xu; Wu, Jianghua; Du, Cuihua; Yuan, Qirong

    2015-02-01

    This paper presents CCD multicolor photometry for 304 old star clusters in the nearby spiral galaxy M31, from which the photometry of 55 star clusters is first obtained. The observations were carried out as a part of the BeijingArizonaTaiwanConnecticut Multicolor Sky Survey from 1995 February to 2008 March, using 15 intermediate-band filters covering 300010000 ?. Detailed comparisons show that our photometry is in agreement with previous measurements. Based on the ages and metallicities from Caldwell et al. and the photometric measurements here, we estimated the clusters masses by comparing their multicolor photometry with stellar population synthesis models. The results show that the sample clusters have masses between ?310{sup 4}M{sub ?} and ?10{sup 7}M{sub ?} with a peak of ?410{sup 5}M{sub ?}. The masses here are in good agreement with those in previous studies. Combined with the masses of young star clusters of M31 from Wang et al., we find that the peak mass of the old clusters is 10 times that of young clusters.

  20. X-ray spectroscopy of manganese clusters

    SciTech Connect (OSTI)

    Grush, M.M.

    1996-06-01

    Much of this thesis represents the groundwork necessary in order to probe Mn clusters more productively than with conventional Mn K-edge XAS and is presented in Part 1. Part 2 contains the application of x-ray techniques to Mn metalloproteins and includes a prognosis at the end of each chapter. Individual Mn oxidation states are more readily distinguishable in Mn L-edge spectra. An empirical mixed valence simulation routine for determining the average Mn oxidation state has been developed. The first Mn L-edge spectra of a metalloprotein were measured and interpreted. The energy of Mn K{beta} emission is strongly correlated with average Mn oxidation state. K{beta} results support oxidation states of Mn(III){sub 2}(IV){sub 2} for the S{sub 1} state of Photosystem II chemical chemically reduced preparations contain predominantly Mn(II). A strength and limitation of XAS is that it probes all of the species of a particular element in a sample. It would often be advantageous to selectively probe different forms of the same element. The first demonstration that chemical shifts in x-ray fluorescence energies can be used to obtain oxidation state-selective x-ray absorption spectra is presented. Spin-dependent spectra can also be used to obtain a more simplified picture of local structure. The first spin-polarized extended x-ray absorption fine structure using Mn K{beta} fluorescence detection is shown.

  1. Viscous sludge sample collector

    DOE Patents [OSTI]

    Beitel, George A [Richland, WA

    1983-01-01

    A vertical core sample collection system for viscous sludge. A sample tube's upper end has a flange and is attached to a piston. The tube and piston are located in the upper end of a bore in a housing. The bore's lower end leads outside the housing and has an inwardly extending rim. Compressed gas, from a storage cylinder, is quickly introduced into the bore's upper end to rapidly accelerate the piston and tube down the bore. The lower end of the tube has a high sludge entering velocity to obtain a full-length sludge sample without disturbing strata detail. The tube's downward motion is stopped when its upper end flange impacts against the bore's lower end inwardly extending rim.

  2. Sampling Report for August 15, 2014 WIPP Samples

    Office of Environmental Management (EM)

    X X X X X Sampling Report for August 15, 2014 WIPP Samples UNCLASSIFIED Forensic Science Center December 19, 2014 Sampling Report for August 15 2014 WIPP Samples Lawrence ...

  3. 2009 Clusters, Nanocrystals & Nanostructures GRC

    SciTech Connect (OSTI)

    Lai-Sheng Wang

    2009-07-19

    For over thirty years, this Gordon Conference has been the premiere meeting for the field of cluster science, which studies the phenomena that arise when matter becomes small. During its history, participants have witnessed the discovery and development of many novel materials, including C60, carbon nanotubes, semiconductor and metal nanocrystals, and nanowires. In addition to addressing fundamental scientific questions related to these materials, the meeting has always included a discussion of their potential applications. Consequently, this conference has played a critical role in the birth and growth of nanoscience and engineering. The goal of the 2009 Gordon Conference is to continue the forward-looking tradition of this meeting and discuss the most recent advances in the field of clusters, nanocrystals, and nanostructures. As in past meetings, this will include new topics that broaden the field. In particular, a special emphasis will be placed on nanomaterials related to the efficient use, generation, or conversion of energy. For example, we anticipate presentations related to batteries, catalysts, photovoltaics, and thermoelectrics. In addition, we expect to address the controversy surrounding carrier multiplication with a session in which recent results addressing this phenomenon will be discussed and debated. The atmosphere of the conference, which emphasizes the presentation of unpublished results and lengthy discussion periods, ensures that attendees will enjoy a valuable and stimulating experience. Because only a limited number of participants are allowed to attend this conference, and oversubscription is anticipated, we encourage all interested researchers from academia, industry, and government institutions to apply as early as possible. An invitation is not required. We also encourage all attendees to submit their latest results for presentation at the poster sessions. We anticipate that several posters will be selected for 'hot topic' oral

  4. ANNULAR IMPACTOR SAMPLING DEVICE

    DOE Patents [OSTI]

    Tait, G.W.C.

    1959-03-31

    A high-rate air sampler capable of sampling alphaemitting particles as small as 0.5 microns is described. The device is a cylindrical shaped cup that fits in front of a suction tube and which has sticky grease coating along its base. Suction forces contaminated air against the periodically monitored particle absorbing grease.

  5. A good mass proxy for galaxy clusters with XMM-Newton

    SciTech Connect (OSTI)

    Zhao, Hai-Hui; Jia, Shu-Mei; Chen, Yong; Li, Cheng-Kui; Song, Li-Ming; Xie, Fei

    2013-12-01

    We use a sample of 39 galaxy clusters at redshift z < 0.1 observed by XMM-Newton to investigate the relations between X-ray observables and total mass. Based on central cooling time and central temperature drop, the clusters in this sample are divided into two groups: 25 cool core clusters and 14 non-cool core clusters, respectively. We study the scaling relations of L {sub bol}-M {sub 500}, M {sub 500}-T, M {sub 500}-M {sub g}, and M {sub 500}-Y {sub X}, and also the influences of cool core on these relations. The results show that the M {sub 500}-Y {sub X} relation has a slope close to the standard self-similar value, has the smallest scatter and does not vary with the cluster sample. Moreover, the M {sub 500}-Y {sub X} relation is not affected by the cool core. Thus, the parameter of Y{sub X} may be the best mass indicator.

  6. IDENTIFICATION OF MEMBERS IN THE CENTRAL AND OUTER REGIONS OF GALAXY CLUSTERS

    SciTech Connect (OSTI)

    Serra, Ana Laura; Diaferio, Antonaldo

    2013-05-10

    The caustic technique measures the mass of galaxy clusters in both their virial and infall regions and, as a byproduct, yields the list of cluster galaxy members. Here we use 100 galaxy clusters with mass M{sub 200} {>=} 10{sup 14} h {sup -1} M{sub Sun} extracted from a cosmological N-body simulation of a {Lambda}CDM universe to test the ability of the caustic technique to identify the cluster galaxy members. We identify the true three-dimensional members as the gravitationally bound galaxies. The caustic technique uses the caustic location in the redshift diagram to separate the cluster members from the interlopers. We apply the technique to mock catalogs containing 1000 galaxies in the field of view of 12 h {sup -1} Mpc on a side at the cluster location. On average, this sample size roughly corresponds to 180 real galaxy members within 3r{sub 200}, similar to recent redshift surveys of cluster regions. The caustic technique yields a completeness, the fraction of identified true members, f{sub c} = 0.95 {+-} 0.03, within 3r{sub 200}. The contamination, the fraction of interlopers in the observed catalog of members, increases from f{sub i}=0.020{sup +0.046}{sub -0.015} at r{sub 200} to f{sub i}=0.08{sup +0.11}{sub -0.05} at 3r{sub 200}. No other technique for the identification of the members of a galaxy cluster provides such large completeness and small contamination at these large radii. The caustic technique assumes spherical symmetry and the asphericity of the cluster is responsible for most of the spread of the completeness and the contamination. By applying the technique to an approximately spherical system obtained by stacking the individual clusters, the spreads decrease by at least a factor of two. We finally estimate the cluster mass within 3r{sub 200} after removing the interlopers: for individual clusters, the mass estimated with the virial theorem is unbiased and within 30% of the actual mass; this spread decreases to less than 10% for the spherically

  7. Field Sampling | Open Energy Information

    Open Energy Info (EERE)

    Field Mapping Hand-held X-Ray Fluorescence (XRF) Macrophotography Portable X-Ray Diffraction (XRD) Field Sampling Gas Sampling Gas Flux Sampling Soil Gas Sampling Surface Gas...

  8. Lattice QCD production on commodity clusters at Fermilab

    SciTech Connect (OSTI)

    D. Holmgren et al.

    2003-09-30

    We describe the construction and results to date of Fermilab's three Myrinet-networked lattice QCD production clusters (an 80-node dual Pentium III cluster, a 48-node dual Xeon cluster, and a 128-node dual Xeon cluster). We examine a number of aspects of performance of the MILC lattice QCD code running on these clusters.

  9. Reinvestigating the clusters Koposov 1 and 2

    SciTech Connect (OSTI)

    Paust, Nathaniel; Wilson, Danielle; Van Belle, Gerard

    2014-07-01

    We investigate the fundamental parameters of age, distance, and mass function slope for the poorly studied clusters Koposov 1 and Koposov 2. These clusters were discovered recently and tentatively classified as globular clusters. Using the Large Monolithic Imager on Lowell Observatory's Discovery Channel Telescope, we present photometry extending to V = 25, three to four magnitudes below the main sequence turnoffs for the clusters. We find the clusters have tidal radii of 15 pc and 10.7 pc and distances of 34.9 kpc and 33.3 kpc for Koposov 1 and Koposov 2, respectively. Studying the stellar content of the clusters, we use completeness-corrected star counts to reveal extremely faint total magnitudes of 2.01 and 0.03 in V, and steep Salpeter-like present-day mass functions. Finally, we show that the spatial positions of the clusters agree well with the position of the Sagittarius stream and conclude that these two objects are open clusters removed from the Sagittarius galaxy.

  10. COMPARING DENSE GALAXY CLUSTER REDSHIFT SURVEYS WITH WEAK-LENSING MAPS

    SciTech Connect (OSTI)

    Hwang, Ho Seong; Geller, Margaret J.; Zahid, H. Jabran; Diaferio, Antonaldo; Rines, Kenneth J. E-mail: mgeller@cfa.harvard.edu E-mail: diaferio@ph.unito.it

    2014-12-20

    We use dense redshift surveys of nine galaxy clusters at z ∼ 0.2 to compare the galaxy distribution in each system with the projected matter distribution from weak lensing. By combining 2087 new MMT/Hectospec redshifts and the data in the literature, we construct spectroscopic samples within the region of weak-lensing maps of high (70%-89%) and uniform completeness. With these dense redshift surveys, we construct galaxy number density maps using several galaxy subsamples. The shape of the main cluster concentration in the weak-lensing maps is similar to the global morphology of the number density maps based on cluster members alone, mainly dominated by red members. We cross-correlate the galaxy number density maps with the weak-lensing maps. The cross-correlation signal when we include foreground and background galaxies at 0.5z {sub cl} < z < 2z {sub cl} is 10%-23% larger than for cluster members alone at the cluster virial radius. The excess can be as high as 30% depending on the cluster. Cross-correlating the galaxy number density and weak-lensing maps suggests that superimposed structures close to the cluster in redshift space contribute more significantly to the excess cross-correlation signal than unrelated large-scale structure along the line of sight. Interestingly, the weak-lensing mass profiles are not well constrained for the clusters with the largest cross-correlation signal excesses (>20% for A383, A689, and A750). The fractional excess in the cross-correlation signal including foreground and background structures could be a useful proxy for assessing the reliability of weak-lensing cluster mass estimates.

  11. The panchromatic Hubble Andromeda Treasury. V. Ages and masses of the year 1 stellar clusters

    SciTech Connect (OSTI)

    Fouesneau, Morgan; Johnson, L. Clifton; Weisz, Daniel R.; Dalcanton, Julianne J.; Williams, Benjamin F.; Bell, Eric F.; Bianchi, Luciana; Caldwell, Nelson; Gouliermis, Dimitrios A.; Guhathakurta, Puragra; Larsen, Sren S.; Rix, Hans-Walter; Seth, Anil C.; Skillman, Evan D.

    2014-05-10

    We present ages and masses for 601 star clusters in M31 from the analysis of the six filter integrated light measurements from near-ultraviolet to near-infrared wavelengths, made as part of the Panchromatic Hubble Andromeda Treasury (PHAT). We derive the ages and masses using a probabilistic technique, which accounts for the effects of stochastic sampling of the stellar initial mass function. Tests on synthetic data show that this method, in conjunction with the exquisite sensitivity of the PHAT observations and their broad wavelength baseline, provides robust age and mass recovery for clusters ranging from ?10{sup 2} to 2 10{sup 6} M {sub ?}. We find that the cluster age distribution is consistent with being uniform over the past 100 Myr, which suggests a weak effect of cluster disruption within M31. The age distribution of older (>100 Myr) clusters falls toward old ages, consistent with a power-law decline of index 1, likely from a combination of fading and disruption of the clusters. We find that the mass distribution of the whole sample can be well described by a single power law with a spectral index of 1.9 0.1 over the range of 10{sup 3}-3 10{sup 5} M {sub ?}. However, if we subdivide the sample by galactocentric radius, we find that the age distributions remain unchanged. However, the mass spectral index varies significantly, showing best-fit values between 2.2 and 1.8, with the shallower slope in the highest star formation intensity regions. We explore the robustness of our study to potential systematics and conclude that the cluster mass function may vary with respect to environment.

  12. Bipartite graph partitioning and data clustering

    SciTech Connect (OSTI)

    Zha, Hongyuan; He, Xiaofeng; Ding, Chris; Gu, Ming; Simon, Horst D.

    2001-05-07

    Many data types arising from data mining applications can be modeled as bipartite graphs, examples include terms and documents in a text corpus, customers and purchasing items in market basket analysis and reviewers and movies in a movie recommender system. In this paper, the authors propose a new data clustering method based on partitioning the underlying biopartite graph. The partition is constructed by minimizing a normalized sum of edge weights between unmatched pairs of vertices of the bipartite graph. They show that an approximate solution to the minimization problem can be obtained by computing a partial singular value decomposition (SVD) of the associated edge weight matrix of the bipartite graph. They point out the connection of their clustering algorithm to correspondence analysis used in multivariate analysis. They also briefly discuss the issue of assigning data objects to multiple clusters. In the experimental results, they apply their clustering algorithm to the problem of document clustering to illustrate its effectiveness and efficiency.

  13. Galaxy cluster baryon fractions revisited

    SciTech Connect (OSTI)

    Gonzalez, Anthony H.; Sivanandam, Suresh; Zabludoff, Ann I.; Zaritsky, Dennis

    2013-11-20

    We measure the baryons contained in both the stellar and hot-gas components for 12 galaxy clusters and groups at z ∼ 0.1 with M = 1-5 × 10{sup 14} M {sub ☉}. This paper improves upon our previous work through the addition of XMM-Newton X-ray data, enabling measurements of the total mass and masses of each major baryonic component—intracluster medium, intracluster stars, and stars in galaxies—for each system. We recover a mean relation for the stellar mass versus halo mass, M{sub ⋆}∝M{sub 500}{sup −0.52±0.04}, that is 1σ shallower than in our previous result. We confirm that the partitioning of baryons between the stellar and hot-gas components is a strong function of M {sub 500}; the fractions of total mass in stars and X-ray gas within a sphere of radius r {sub 500} scale as f{sub ⋆}∝M{sub 500}{sup −0.45±0.04} and f{sub gas}∝M{sub 500}{sup 0.26±0.03}, respectively. We also confirm that the combination of the brightest cluster galaxy and intracluster stars is an increasingly important contributor to the stellar baryon budget in lower halo masses. Studies that fail to fully account for intracluster stars typically underestimate the normalization of the stellar baryon fraction versus M {sub 500} relation by ∼25%. Our derived stellar baryon fractions are also higher, and the trend with halo mass weaker, than those derived from recent halo occupation distribution and abundance matching analyses. One difference from our previous work is the weak, but statistically significant, dependence here of the total baryon fraction upon halo mass: f{sub bary}∝M{sub 500}{sup 0.16±0.04}. For M {sub 500} ≳ 2 × 10{sup 14}, the total baryon fractions within r {sub 500} are on average 18% below the universal value from the seven year Wilkinson Microwave Anisotropy Probe (WMAP) analysis, or 7% below for the cosmological parameters from the Planck analysis. In the latter case, the difference between the universal value and cluster baryon fractions is

  14. A faint galaxy redshift survey behind massive clusters

    SciTech Connect (OSTI)

    Frye, Brenda

    1999-12-01

    This thesis is concerned with the gravitational lensing effect by massive galaxy clusters. We have explored a new technique for measuring galaxy masses and for detecting high-z galaxies by their optical colors. A redshift survey has been obtained at the Keck for a magnitude limited sample of objects (I<23) behind three clusters, A1689, A2390, and A2218 within a radius of 0.5M pc. For each cluster we see both a clear trend of increasing flux and redshift towards the center. This behavior is the result of image magnifications, such that at fixed redshift one sees further down the luminosity function. The gradient of this magnification is, unlike measurements of image distortion, sensitive to the mass profile, and found to depart strongly from a pure isothermal halo. We have found that V RI color selection can be used effectively as a discriminant for finding high-z galaxies behind clusters and present five 4.1 < z < 5.1 spectra which are of very high quality due to their high mean magnification of {approximately}20, showing strong, visibly-saturated interstellar metal lines in some cases. We have also investigated the radio ring lens PKS 1830-211, locating the source and multiple images and detected molecular absorption at mm wavelengths. Broad molecular absorption of width 1/40kms is found toward the southwest component only, where surprisingly it does not reach the base of the continuum, which implies incomplete coverage of the SW component by molecular gas, despite the small projected size of the source, less than 1/8h pc at the absorption redshift.

  15. NREL: Measurements and Characterization - Surface Analysis Cluster Tool

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

    Surface Analysis Cluster Tool Floor plan showing where surface analysis cluster equipment sits. Schematic diagram of the surface analysis cluster tool. Photograph of the Surface Analysis Cluster Tool The surface analysis cluster tool was designed and built by NREL for the in-situ study of surface and chemical changes. Residing in our new Science and Technology Facility (S&TF), is the surface analysis cluster tool that the National Renewable Energy Laboratory recently designed and built for

  16. NID Copper Sample Analysis

    SciTech Connect (OSTI)

    Kouzes, Richard T.; Zhu, Zihua

    2011-09-12

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0νββ). This experiment requires the use of germanium isotopically enriched in 76Ge. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology, possibly one under development at Nonlinear Ion Dynamics (NID), will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL in January 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are reported here. A second sample of isotopically separated copper was provided by NID to PNNL in August 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are also reported here.

  17. Stack sampling apparatus

    DOE Patents [OSTI]

    Lind, Randall F; Lloyd, Peter D; Love, Lonnie J; Noakes, Mark W; Pin, Francois G; Richardson, Bradley S; Rowe, John C

    2014-09-16

    An apparatus for obtaining samples from a structure includes a support member, at least one stabilizing member, and at least one moveable member. The stabilizing member has a first portion coupled to the support member and a second portion configured to engage with the structure to restrict relative movement between the support member and the structure. The stabilizing member is radially expandable from a first configuration where the second portion does not engage with a surface of the structure to a second configuration where the second portion engages with the surface of the structure.

  18. Germanium-76 Sample Analysis

    SciTech Connect (OSTI)

    Kouzes, Richard T.; Engelhard, Mark H.; Zhu, Zihua

    2011-04-01

    The MAJORANA DEMONSTRATOR is a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0???). The DEMONSTRATOR will utilize 76Ge from Russia, and the first one gram sample was received from the supplier for analysis on April 24, 2011. The Environmental Molecular Sciences facility, a DOE user facility at PNNL, was used to make the required isotopic and chemical purity measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR. The results of this first analysis are reported here.

  19. September 2004 Water Sampling

    Office of Legacy Management (LM)

    4 Groundwater Sampling at the Central Nevada Test Area February 2015 LMS/CNT/S01214 Available for sale to the public from: U.S. Department of Commerce National Technical Information Service 5301 Shawnee Road Alexandria, VA 22312 Telephone: 800.553.6847 Fax: 703.605.6900 E-mail: orders@ntis.gov Online Ordering: http://www.ntis.gov/help/ordermethods.aspx Available electronically at http://www.osti.gov/scitech/ Available for a processing fee to U.S. Department of Energy and its contractors, in

  20. Pulsed field sample neutralization

    DOE Patents [OSTI]

    Appelhans, Anthony D.; Dahl, David A.; Delmore, James E.

    1990-01-01

    An apparatus and method for alternating voltage and for varying the rate of extraction during the extraction of secondary particles, resulting in periods when either positive ions, or negative ions and electrons are extracted at varying rates. Using voltage with alternating charge during successive periods to extract particles from materials which accumulate charge opposite that being extracted causes accumulation of surface charge of opposite sign. Charge accumulation can then be adjusted to a ratio which maintains a balance of positive and negative charge emission, thus maintaining the charge neutrality of the sample.

  1. Post-Award Deliverables Sample (Part 2 of Sample Deliverables...

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

    J-4) Post-Award Deliverables Sample (Part 2 of Sample Deliverables for Task Orders, IDIQ Attachment. J-4) Document offers a post-award deliverables sample for an energy savings ...

  2. THE HST/ACS COMA CLUSTER SURVEY. VIII. BARRED DISK GALAXIES IN THE CORE OF THE COMA CLUSTER

    SciTech Connect (OSTI)

    Marinova, Irina; Jogee, Shardha; Weinzirl, Tim; Erwin, Peter; Trentham, Neil; Ferguson, Henry C.; Goudfrooij, Paul; Hammer, Derek; Den Brok, Mark; Peletier, Reynier F.; Kleijn, Gijs V.; Graham, Alister W.; Carter, David; Mouhcine, Mustapha; Balcells, Marc; Guzman, Rafael; Hoyos, Carlos; Mobasher, Bahram; Peng, Eric W. E-mail: sj@astro.as.utexas.edu

    2012-02-20

    We use high-resolution ({approx}0.''1) F814W Advanced Camera for Surveys (ACS) images from the Hubble Space Telescope ACS Treasury survey of the Coma cluster at z {approx} 0.02 to study bars in massive disk galaxies (S0s), as well as low-mass dwarf galaxies in the core of the Coma cluster, the densest environment in the nearby universe. Our study helps to constrain the evolution of bars and disks in dense environments and provides a comparison point for studies in lower density environments and at higher redshifts. Our results are: (1) we characterize the fraction and properties of bars in a sample of 32 bright (M{sub V} {approx}< -18, M{sub *} > 10{sup 9.5} M{sub Sun }) S0 galaxies, which dominate the population of massive disk galaxies in the Coma core. We find that the measurement of a bar fraction among S0 galaxies must be handled with special care due to the difficulty in separating unbarred S0s from ellipticals, and the potential dilution of the bar signature by light from a relatively large, bright bulge. The results depend sensitively on the method used: the bar fraction for bright S0s in the Coma core is 50% {+-} 11%, 65% {+-} 11%, and 60% {+-} 11% based on three methods of bar detection, namely, strict ellipse fit criteria, relaxed ellipse fit criteria, and visual classification. (2) We compare the S0 bar fraction across different environments (the Coma core, A901/902, and Virgo) adopting the critical step of using matched samples and matched methods in order to ensure robust comparisons. We find that the bar fraction among bright S0 galaxies does not show a statistically significant variation (within the error bars of {+-}11%) across environments which span two orders of magnitude in galaxy number density (n {approx} 300-10,000 galaxies Mpc{sup -3}) and include rich and poor clusters, such as the core of Coma, the A901/902 cluster, and Virgo. We speculate that the bar fraction among S0s is not significantly enhanced in rich clusters compared to low

  3. Constraints on the richness-mass relation and the optical-SZE positional offset distribution for SZE-selected clusters

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

    Saro, A.

    2015-10-12

    In this study, we cross-match galaxy cluster candidates selected via their Sunyaev–Zel'dovich effect (SZE) signatures in 129.1 deg2 of the South Pole Telescope 2500d SPT-SZ survey with optically identified clusters selected from the Dark Energy Survey science verification data. We identify 25 clusters between 0.1 ≲ z ≲ 0.8 in the union of the SPT-SZ and redMaPPer (RM) samples. RM is an optical cluster finding algorithm that also returns a richness estimate for each cluster. We model the richness λ-mass relation with the following function 500> ∝ Bλln M500 + Cλln E(z) and use SPT-SZ cluster masses and RM richnessesmore » λ to constrain the parameters. We find Bλ=1.14+0.21–0.18 and Cλ=0.73+0.77–0.75. The associated scatter in mass at fixed richness is σlnM|λ = 0.18+0.08–0.05 at a characteristic richness λ = 70. We demonstrate that our model provides an adequate description of the matched sample, showing that the fraction of SPT-SZ-selected clusters with RM counterparts is consistent with expectations and that the fraction of RM-selected clusters with SPT-SZ counterparts is in mild tension with expectation. We model the optical-SZE cluster positional offset distribution with the sum of two Gaussians, showing that it is consistent with a dominant, centrally peaked population and a subdominant population characterized by larger offsets. We also cross-match the RM catalogue with SPT-SZ candidates below the official catalogue threshold significance ξ = 4.5, using the RM catalogue to provide optical confirmation and redshifts for 15 additional clusters with ξ ε [4, 4.5].« less

  4. Analysis of Molecular Clusters in Simulations of Lithium-Ion...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Analysis of Molecular Clusters in Simulations of Lithium-Ion Battery Electrolytes. Citation Details In-Document Search Title: Analysis of Molecular Clusters in ...

  5. Three-dimensional Modeling of Fracture Clusters in Geothermal...

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

    Reservoirs Three-dimensional Modeling of Fracture Clusters in Geothermal Reservoirs ... More Documents & Publications Three-dimensional Modeling of Fracture Clusters in ...

  6. Three-dimensional Modeling of Fracture Clusters in Geeothermal...

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

    Three-dimensional Modeling of Fracture Clusters in Geeothermal Reservoirs Three-dimensional Modeling of Fracture Clusters in Geeothermal Reservoirs Three-dimensional Modeling of ...

  7. Reactive Molecular Simulations of Protonation of Water Clusters...

    Office of Scientific and Technical Information (OSTI)

    of Water Clusters and Depletion of Acidity in H-ZSM-5 Zeolite Citation Details In-Document Search Title: Reactive Molecular Simulations of Protonation of Water Clusters ...

  8. Northern Colorado Clean Energy Cluster | Open Energy Information

    Open Energy Info (EERE)

    Clean Energy Cluster Jump to: navigation, search Name: Northern Colorado Clean Energy Cluster Place: Denver, Colorado Zip: 80202 Region: Rockies Area Website: www.nccleanenergy.com...

  9. Toward Understanding the Microscopic Origin of Nuclear Clustering...

    Office of Scientific and Technical Information (OSTI)

    Toward Understanding the Microscopic Origin of Nuclear Clustering Citation Details In-Document Search Title: Toward Understanding the Microscopic Origin of Nuclear Clustering Open...

  10. Formation of Compact Clusters from High Resolution Hybrid Cosmological...

    Office of Scientific and Technical Information (OSTI)

    Formation of Compact Clusters from High Resolution Hybrid Cosmological Simulations Citation Details In-Document Search Title: Formation of Compact Clusters from High Resolution ...

  11. Hα star formation rates of z > 1 galaxy clusters in the IRAC shallow cluster survey

    SciTech Connect (OSTI)

    Zeimann, Gregory R.; Stanford, S. A.; Brodwin, Mark; Gonzalez, Anthony H.; Mancone, Conor; Snyder, Gregory F.; Stern, Daniel; Eisenhardt, Peter; Dey, Arjun; Moustakas, John

    2013-12-20

    We present Hubble Space Telescope near-IR spectroscopy for 18 galaxy clusters at 1.0 Cluster Survey. We use Wide Field Camera 3 grism data to spectroscopically identify Hα emitters in both the cores of galaxy clusters as well as in field galaxies. We find a large cluster-to-cluster scatter in the star formation rates within a projected radius of 500 kpc, and many of our clusters (∼60%) have significant levels of star formation within a projected radius of 200 kpc. A stacking analysis reveals that dust reddening in these star-forming galaxies is positively correlated with stellar mass and may be higher in the field than the cluster at a fixed stellar mass. This may indicate a lower amount of gas in star-forming cluster galaxies than in the field population. Also, Hα equivalent widths of star-forming galaxies in the cluster environment are still suppressed below the level of the field. This suppression is most significant for lower mass galaxies (log M {sub *} < 10.0 M {sub ☉}). We therefore conclude that environmental effects are still important at 1.0 clusters with log M {sub *} ≲ 10.0 M {sub ☉}.

  12. Method for assaying clustered DNA damages

    DOE Patents [OSTI]

    Sutherland, Betsy M.

    2004-09-07

    Disclosed is a method for detecting and quantifying clustered damages in DNA. In this method, a first aliquot of the DNA to be tested for clustered damages with one or more lesion-specific cleaving reagents under conditions appropriate for cleavage of the DNA to produce single-strand nicks in the DNA at sites of damage lesions. The number average molecular length (Ln) of double stranded DNA is then quantitatively determined for the treated DNA. The number average molecular length (Ln) of double stranded DNA is also quantitatively determined for a second, untreated aliquot of the DNA. The frequency of clustered damages (.PHI..sub.c) in the DNA is then calculated.

  13. Microsoft Word - Fe-S_Clusters

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

    April 2010 Figure 1. Top: overall ribbon and surface representation of the x-ray crystal structure of [FeFe]-hydrogenase HydA ΔEFG . Loop regions important for the cluster insertion process are colored green. Bottom: Ball and stick representation of the active site of HydA ΔEFG at which a [4Fe-4S] cluster is present. Coloring scheme: rust, iron; orange, sulfur; gray, carbon; red, oxygen; blue, nitrogen. Assembly and Evolution of Complex Fe-S Clusters as Revealed by X-ray Crystallography

  14. Fluid sampling tool

    DOE Patents [OSTI]

    Garcia, Anthony R.; Johnston, Roger G.; Martinez, Ronald K.

    1999-05-25

    A fluid sampling tool for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall.

  15. NID Copper Sample Analysis

    SciTech Connect (OSTI)

    Kouzes, Richard T.; Zhu, Zihua

    2011-02-01

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0νββ). This experiment requires the use of germanium isotopically enriched in 76Ge. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology under development at Nonlinear Ion Dynamics (NID) will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making these isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL for isotopic analysis as a test of the NID technology. The results of that analysis are reported here.

  16. Fluid sampling tool

    DOE Patents [OSTI]

    Garcia, A.R.; Johnston, R.G.; Martinez, R.K.

    1999-05-25

    A fluid sampling tool is described for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall. 6 figs.

  17. TIME-SERIES PHOTOMETRY OF GLOBULAR CLUSTERS: M62 (NGC 6266), THE MOST RR LYRAE-RICH GLOBULAR CLUSTER IN THE GALAXY?

    SciTech Connect (OSTI)

    Contreras, R.; Catelan, M.; Smith, H. A.; Kuehn, C. A.; Pritzl, B. J.; Borissova, J.

    2010-12-15

    We present new time-series CCD photometry, in the B and V bands, for the moderately metal-rich ([Fe/H] {approx_equal} -1.3) Galactic globular cluster M62 (NGC 6266). The present data set is the largest obtained so far for this cluster and consists of 168 images per filter, obtained with the Warsaw 1.3 m telescope at the Las Campanas Observatory and the 1.3 m telescope of the Cerro Tololo Inter-American Observatory, in two separate runs over the time span of 3 months. The procedure adopted to detect the variable stars was the optimal image subtraction method (ISIS v2.2), as implemented by Alard. The photometry was performed using both ISIS and Stetson's DAOPHOT/ALLFRAME package. We have identified 245 variable stars in the cluster fields that have been analyzed so far, of which 179 are new discoveries. Of these variables, 133 are fundamental mode RR Lyrae stars (RRab), 76 are first overtone (RRc) pulsators, 4 are type II Cepheids, 25 are long-period variables (LPVs), 1 is an eclipsing binary, and 6 are not yet well classified. Such a large number of RR Lyrae stars places M62 among the top two most RR Lyrae-rich (in the sense of total number of RR Lyrae stars present) globular clusters known in the Galaxy, second only to M3 (NGC 5272) with a total of 230 known RR Lyrae stars. Since this study covers most but not all of the cluster area, it is not unlikely that M62 is in fact the most RR Lyrae-rich globular cluster in the Galaxy. In like vein, thanks to the time coverage of our data sets, we were also able to detect the largest sample of LPVs known so far in a Galactic globular cluster. We analyze a variety of Oosterhoff type indicators for the cluster, including mean periods, period distribution, Bailey diagrams, and Fourier decomposition parameters (as well as the physical parameters derived therefrom). All of these indicators clearly show that M62 is an Oosterhoff type I system. This is in good agreement with the moderately high metallicity of the cluster, in spite

  18. UPDATED MASS SCALING RELATIONS FOR NUCLEAR STAR CLUSTERS AND A COMPARISON TO SUPERMASSIVE BLACK HOLES

    SciTech Connect (OSTI)

    Scott, Nicholas; Graham, Alister W.

    2013-02-15

    We investigate whether or not nuclear star clusters and supermassive black holes (SMBHs) follow a common set of mass scaling relations with their host galaxy's properties, and hence can be considered to form a single class of central massive object (CMO). We have compiled a large sample of galaxies with measured nuclear star cluster masses and host galaxy properties from the literature and fit log-linear scaling relations. We find that nuclear star cluster mass, M {sub NC}, correlates most tightly with the host galaxy's velocity dispersion: log M {sub NC} = (2.11 {+-} 0.31)log ({sigma}/54) + (6.63 {+-} 0.09), but has a slope dramatically shallower than the relation defined by SMBHs. We find that the nuclear star cluster mass relations involving host galaxy (and spheroid) luminosity and stellar and dynamical mass, intercept with but are in general shallower than the corresponding black hole scaling relations. In particular, M {sub NC}{proportional_to}M {sup 0.55{+-}0.15} {sub Gal,dyn}; the nuclear cluster mass is not a constant fraction of its host galaxy or spheroid mass. We conclude that nuclear stellar clusters and SMBHs do not form a single family of CMOs.

  19. SODIUM AND OXYGEN ABUNDANCES IN THE OPEN CLUSTER NGC 6791 FROM APOGEE H-BAND SPECTROSCOPY

    SciTech Connect (OSTI)

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

    2015-01-10

    The open cluster NGC 6791 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 NGC 6791 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} ∼ 3500-4600 K), 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 Å and 16388.85 Å) 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.

  20. GALAXY EVOLUTION IN OVERDENSE ENVIRONMENTS AT HIGH REDSHIFT: PASSIVE EARLY-TYPE GALAXIES IN A CLUSTER AT z {approx} 2

    SciTech Connect (OSTI)

    Strazzullo, V.; Gobat, R.; Daddi, E.; Onodera, M.; Carollo, M.; Dickinson, M.; Renzini, A.; Arimoto, N.; Cimatti, A.; Finoguenov, A.; Chary, R.-R.

    2013-08-01

    We present a study of galaxy populations in the central region of the IRAC-selected, X-ray-detected galaxy cluster Cl J1449+0856 at z = 2. Based on a sample of spectroscopic and photometric cluster members, we investigate stellar populations and the morphological structure of cluster galaxies over an area of {approx}0.7 Mpc{sup 2} around the cluster core. The cluster stands out as a clear overdensity both in redshift space and in the spatial distribution of galaxies close to the center of the extended X-ray emission. The cluster core region (r < 200 kpc) shows a clearly enhanced passive fraction with respect to field levels. However, together with a population of massive, passive galaxies mostly with early-type morphologies, the cluster core also hosts massive, actively star-forming, often highly dust reddened sources. Close to the cluster center, a multi-component system of passive and star-forming galaxies could represent the future brightest cluster galaxy still forming. We observe a clear correlation between passive stellar populations and an early-type morphology, in agreement with field studies at similar redshift. Passive early-type galaxies in this cluster are typically a factor of 2-3 smaller than similarly massive early types at z {approx} 0. On the other hand, these same objects are on average larger by a factor of {approx}2 than field early-types at similar redshift, lending support to recent claims of an accelerated structural evolution in high-redshift dense environments. These results point toward the early formation of a population of massive galaxies, already evolved both in their structure and stellar populations, coexisting with still actively forming massive galaxies in the central regions of young clusters 10 billion years ago.

  1. Sample introducing apparatus and sample modules for mass spectrometer

    DOE Patents [OSTI]

    Thompson, Cyril V.; Wise, Marcus B.

    1993-01-01

    An apparatus for introducing gaseous samples from a wide range of environmental matrices into a mass spectrometer for analysis of the samples is described. Several sample preparing modules including a real-time air monitoring module, a soil/liquid purge module, and a thermal desorption module are individually and rapidly attachable to the sample introducing apparatus for supplying gaseous samples to the mass spectrometer. The sample-introducing apparatus uses a capillary column for conveying the gaseous samples into the mass spectrometer and is provided with an open/split interface in communication with the capillary and a sample archiving port through which at least about 90 percent of the gaseous sample in a mixture with an inert gas that was introduced into the sample introducing apparatus is separated from a minor portion of the mixture entering the capillary discharged from the sample introducing apparatus.

  2. Sample introducing apparatus and sample modules for mass spectrometer

    DOE Patents [OSTI]

    Thompson, C.V.; Wise, M.B.

    1993-12-21

    An apparatus for introducing gaseous samples from a wide range of environmental matrices into a mass spectrometer for analysis of the samples is described. Several sample preparing modules including a real-time air monitoring module, a soil/liquid purge module, and a thermal desorption module are individually and rapidly attachable to the sample introducing apparatus for supplying gaseous samples to the mass spectrometer. The sample-introducing apparatus uses a capillary column for conveying the gaseous samples into the mass spectrometer and is provided with an open/split interface in communication with the capillary and a sample archiving port through which at least about 90 percent of the gaseous sample in a mixture with an inert gas that was introduced into the sample introducing apparatus is separated from a minor portion of the mixture entering the capillary discharged from the sample introducing apparatus. 5 figures.

  3. Soil sampling kit and a method of sampling therewith

    DOE Patents [OSTI]

    Thompson, Cyril V.

    1991-01-01

    A soil sampling device and a sample containment device for containing a soil sample is disclosed. In addition, a method for taking a soil sample using the soil sampling device and soil sample containment device to minimize the loss of any volatile organic compounds contained in the soil sample prior to analysis is disclosed. The soil sampling device comprises two close fitting, longitudinal tubular members of suitable length, the inner tube having the outward end closed. With the inner closed tube withdrawn a selected distance, the outer tube can be inserted into the ground or other similar soft material to withdraw a sample of material for examination. The inner closed end tube controls the volume of the sample taken and also serves to eject the sample. The soil sample containment device has a sealing member which is adapted to attach to an analytical apparatus which analyzes the volatile organic compounds contained in the sample. The soil sampling device in combination with the soil sample containment device allow an operator to obtain a soil sample containing volatile organic compounds and minimizing the loss of the volatile organic compounds prior to analysis of the soil sample for the volatile organic compounds.

  4. Soil sampling kit and a method of sampling therewith

    DOE Patents [OSTI]

    Thompson, C.V.

    1991-02-05

    A soil sampling device and a sample containment device for containing a soil sample is disclosed. In addition, a method for taking a soil sample using the soil sampling device and soil sample containment device to minimize the loss of any volatile organic compounds contained in the soil sample prior to analysis is disclosed. The soil sampling device comprises two close fitting, longitudinal tubular members of suitable length, the inner tube having the outward end closed. With the inner closed tube withdrawn a selected distance, the outer tube can be inserted into the ground or other similar soft material to withdraw a sample of material for examination. The inner closed end tube controls the volume of the sample taken and also serves to eject the sample. The soil sample containment device has a sealing member which is adapted to attach to an analytical apparatus which analyzes the volatile organic compounds contained in the sample. The soil sampling device in combination with the soil sample containment device allows an operator to obtain a soil sample containing volatile organic compounds and minimizing the loss of the volatile organic compounds prior to analysis of the soil sample for the volatile organic compounds. 11 figures.

  5. Fluid sampling apparatus and method

    DOE Patents [OSTI]

    Yeamans, David R.

    1998-01-01

    Incorporation of a bellows in a sampling syringe eliminates ingress of contaminants, permits replication of amounts and compression of multiple sample injections, and enables remote sampling for off-site analysis.

  6. Fluid sampling apparatus and method

    DOE Patents [OSTI]

    Yeamans, D.R.

    1998-02-03

    Incorporation of a bellows in a sampling syringe eliminates ingress of contaminants, permits replication of amounts and compression of multiple sample injections, and enables remote sampling for off-site analysis. 3 figs.

  7. A Measurement of Gravitational Lensing of the Cosmic Microwave Background by Galaxy Clusters Using Data from the South Pole Telescope

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

    Baxter, E. J.; Keisler, R.; Dodelson, S.; Aird, K. A.; Allen, S. W.; Ashby, M. L.N.; Bautz, M.; Bayliss, M.; Benson, B. A.; Bleem, L. E.; et al

    2015-06-22

    Clusters of galaxies are expected to gravitationally lens the cosmic microwave background (CMB) and thereby generate a distinct signal in the CMB on arcminute scales. Measurements of this effect can be used to constrain the masses of galaxy clusters with CMB data alone. Here we present a measurement of lensing of the CMB by galaxy clusters using data from the South Pole Telescope (SPT). We also develop a maximum likelihood approach to extract the CMB cluster lensing signal and validate the method on mock data. We quantify the effects on our analysis of several potential sources of systematic error andmore » find that they generally act to reduce the best-fit cluster mass. It is estimated that this bias to lower cluster mass is roughly 0.85σ in units of the statistical error bar, although this estimate should be viewed as an upper limit. Furthermore, we apply our maximum likelihood technique to 513 clusters selected via their Sunyaev–Zeldovich (SZ) signatures in SPT data, and rule out the null hypothesis of no lensing at 3.1σ. The lensing-derived mass estimate for the full cluster sample is consistent with that inferred from the SZ flux: M200,lens = 0.83+0.38-0.37 M200,SZ (68% C.L., statistical error only).« less

  8. Fluid sampling tool

    DOE Patents [OSTI]

    Johnston, Roger G.; Garcia, Anthony R. E.; Martinez, Ronald K.

    2001-09-25

    The invention includes a rotatable tool for collecting fluid through the wall of a container. The tool includes a fluid collection section with a cylindrical shank having an end portion for drilling a hole in the container wall when the tool is rotated, and a threaded portion for tapping the hole in the container wall. A passageway in the shank in communication with at least one radial inlet hole in the drilling end and an opening at the end of the shank is adapted to receive fluid from the container. The tool also includes a cylindrical chamber affixed to the end of the shank opposite to the drilling portion thereof for receiving and storing fluid passing through the passageway. The tool also includes a flexible, deformable gasket that provides a fluid-tight chamber to confine kerf generated during the drilling and tapping of the hole. The invention also includes a fluid extractor section for extracting fluid samples from the fluid collecting section.

  9. Fermi-LAT constraints on dark matter annihilation cross section from observations of the Fornax cluster

    SciTech Connect (OSTI)

    Ando, Shin'ichiro; Nagai, Daisuke E-mail: daisuke.nagai@yale.edu

    2012-07-01

    We analyze 2.8-yr data of 1–100 GeV photons for clusters of galaxies, collected with the Large Area Telescope onboard the Fermi satellite. By analyzing 49 nearby massive clusters located at high Galactic latitudes, we find no excess gamma-ray emission towards directions of the galaxy clusters. Using flux upper limits, we show that the Fornax cluster provides the most stringent constraints on the dark matter annihilation cross section. Stacking a large sample of nearby clusters does not help improve the limit for most dark matter models. This suggests that a detailed modeling of the Fornax cluster is important for setting robust limits on the dark matter annihilation cross section based on clusters. We therefore perform the detailed mass modeling and predict the expected dark matter annihilation signals from the Fornax cluster, by taking into account effects of dark matter contraction and substructures. By modeling the mass distribution of baryons (stars and gas) around a central bright elliptical galaxy, NGC 1399, and using a modified contraction model motivated by numerical simulations, we show that the dark matter contraction boosts the annihilation signatures by a factor of 4. For dark matter masses around 10 GeV, the upper limit obtained on the annihilation cross section times relative velocity is (σν)∼<(2–3) × 10{sup −25} cm{sup 3} s{sup −1}, which is within a factor of 10 from the value required to explain the dark matter relic density. This effect is more robust than the annihilation boost due to substructure, and it is more important unless the mass of the smallest subhalos is much smaller than that of the Sun.

  10. JELLYFISH: EVIDENCE OF EXTREME RAM-PRESSURE STRIPPING IN MASSIVE GALAXY CLUSTERS

    SciTech Connect (OSTI)

    Ebeling, H.; Stephenson, L. N.; Edge, A. C.

    2014-02-01

    Ram-pressure stripping by the gaseous intracluster medium has been proposed as the dominant physical mechanism driving the rapid evolution of galaxies in dense environments. Detailed studies of this process have, however, largely been limited to relatively modest examples affecting only the outermost gas layers of galaxies in nearby and/or low-mass galaxy clusters. We here present results from our search for extreme cases of gas-galaxy interactions in much more massive, X-ray selected clusters at z > 0.3. Using Hubble Space Telescope snapshots in the F606W and F814W passbands, we have discovered dramatic evidence of ram-pressure stripping in which copious amounts of gas are first shock compressed and then removed from galaxies falling into the cluster. Vigorous starbursts triggered by this process across the galaxy-gas interface and in the debris trail cause these galaxies to temporarily become some of the brightest cluster members in the F606W passband, capable of outshining even the Brightest Cluster Galaxy. Based on the spatial distribution and orientation of systems viewed nearly edge-on in our survey, we speculate that infall at large impact parameter gives rise to particularly long-lasting stripping events. Our sample of six spectacular examples identified in clusters from the Massive Cluster Survey, all featuring M {sub F606W} < 21 mag, doubles the number of such systems presently known at z > 0.2 and facilitates detailed quantitative studies of the most violent galaxy evolution in clusters.

  11. Visual cluster analysis and pattern recognition methods

    DOE Patents [OSTI]

    Osbourn, Gordon Cecil; Martinez, Rubel Francisco

    2001-01-01

    A method of clustering using a novel template to define a region of influence. Using neighboring approximation methods, computation times can be significantly reduced. The template and method are applicable and improve pattern recognition techniques.

  12. Feature Clustering for Accelerating Parallel Coordinate Descent

    SciTech Connect (OSTI)

    Scherrer, Chad; Tewari, Ambuj; Halappanavar, Mahantesh; Haglin, David J.

    2012-12-06

    We demonstrate an approach for accelerating calculation of the regularization path for L1 sparse logistic regression problems. We show the benefit of feature clustering as a preconditioning step for parallel block-greedy coordinate descent algorithms.

  13. Rock Sampling | Open Energy Information

    Open Energy Info (EERE)

    resource at depth. These hand samples can be collected using a rock hammer or sledge. Data Access and Acquisition Under a detailed investigation, a systematic sampling procedure...

  14. Water Sampling | Open Energy Information

    Open Energy Info (EERE)

    Water Sampling Details Activities (63) Areas (51) Regions (5) NEPA(2) Exploration Technique Information Exploration Group: Field Techniques Exploration Sub Group: Field Sampling...

  15. Accelerating semantic graph databases on commodity clusters

    SciTech Connect (OSTI)

    Morari, Alessandro; Castellana, Vito G.; Haglin, David J.; Feo, John T.; Weaver, Jesse R.; Tumeo, Antonino; Villa, Oreste

    2013-10-06

    We are developing a full software system for accelerating semantic graph databases on commodity cluster that scales to hundreds of nodes while maintaining constant query throughput. Our framework comprises a SPARQL to C++ compiler, a library of parallel graph methods and a custom multithreaded runtime layer, which provides a Partitioned Global Address Space (PGAS) programming model with fork/join parallelism and automatic load balancing over a commodity clusters. We present preliminary results for the compiler and for the runtime.

  16. Electron attenuation in free, neutral ethane clusters

    SciTech Connect (OSTI)

    Winkler, M.; Harnes, J.; Brve, K. J.; Myrseth, V.

    2014-10-28

    The electron effective attenuation length (EAL) in free, neutral ethane clusters has been determined at 40 eV kinetic energy by combining carbon 1s x-ray photoelectron spectroscopy and theoretical lineshape modeling. More specifically, theory is employed to form model spectra on a grid in cluster size (N) and EAL (?), allowing N and ? to be determined by optimizing the goodness-of-fit ?{sup 2}(N, ?) between model and observed spectra. Experimentally, the clusters were produced in an adiabatic-expansion setup using helium as the driving gas, spanning a range of 100600 molecules in mean cluster size. The effective attenuation length was determined to be 8.4??1.9 , in good agreement with an independent estimate of 10 formed on the basis of molecular electron-scattering data and Monte Carlo simulations. The aggregation state of the clusters as well as the cluster temperature and its importance to the derived EAL value are discussed in some depth.

  17. Sputtering of neutral and ionic indium clusters

    SciTech Connect (OSTI)

    Ma, Z.; Coon, S.R.; Calaway, W.F.; Pellin, M.J.; Gruen, D.M.; Von Nagy-Felsobuki, E.I.

    1993-10-01

    Secondary neutral and secondary ion cluster yields were measured during the sputtering of a polycrystalline indium surface by normally incident {approximately}4 keV Ar{sup +} ions. In the secondary neutral mass spectra, indium clusters as large as In{sub 32} were observed. In the secondary ion mass spectra, indium clusters up to In{sub 18}{sup +} were recorded. Cluster yields obtained from both the neutral and ion channel exhibited a power law dependence on the number of constituent atoms, n, in the cluster, with the exponents measured to be {minus}5.6 and {minus}4. 1, respectively. An abundance drop was observed at n=8, 15, and 16 in both the neutral and ion yield distributions suggesting that the stability of the ion (either secondary ion or photoion) plays a significant role in the observed distributions. In addition, our experiments suggest that unimolecular decomposition of the neutral cluster may also plays an important role in the measured yield distributions.

  18. Cosmology and astrophysics with galaxy clusters

    SciTech Connect (OSTI)

    Nagai, Daisuke

    2014-11-20

    Galaxy clusters are the largest gravitationally bound objects in the universe, whose formation is driven by dark energy and dark matter. The majority of the baryonic mass in clusters resides in the hot X-ray emitting plasma, which also leaves imprints in the cosmic microwave background radiation. Recent X-ray and microwave observations have revealed detailed thermodynamic structure of the hot X-ray emitting plasma from their cores to the virial radii, making comparisons of baryonic component in simulations to observations a strong cosmological probe. However, the statistical power of these future surveys can only be exploited for cosmology if and only if we are able to measure the cluster mass with a very high precision. I will discuss recent progress and future challenges for the use of galaxy clusters as precise cosmological probes, with highlights on (1) the importance of understanding thermodynamics and plasma physics in the outskirts of galaxy clusters and (2) prospects for improving the power of cluster-based cosmological measurements using numerical simulations and multi-wavelength observations.

  19. Sample holder with optical features

    DOE Patents [OSTI]

    Milas, Mirko; Zhu, Yimei; Rameau, Jonathan David

    2013-07-30

    A sample holder for holding a sample to be observed for research purposes, particularly in a transmission electron microscope (TEM), generally includes an external alignment part for directing a light beam in a predetermined beam direction, a sample holder body in optical communication with the external alignment part and a sample support member disposed at a distal end of the sample holder body opposite the external alignment part for holding a sample to be analyzed. The sample holder body defines an internal conduit for the light beam and the sample support member includes a light beam positioner for directing the light beam between the sample holder body and the sample held by the sample support member.

  20. NEW TESTS FOR DISRUPTION MECHANISMS OF STAR CLUSTERS: THE LARGE AND SMALL MAGELLANIC CLOUDS

    SciTech Connect (OSTI)

    Chandar, Rupali; Fall, S. Michael; Whitmore, Bradley C. E-mail: fall@stsci.ed

    2010-03-10

    We compare the observed bivariate distribution of masses (M) and ages (tau) of star clusters in the Large Magellanic Cloud (LMC) with the predicted distributions g(M, tau) from three idealized models for the disruption of star clusters: (1) sudden mass-dependent disruption, (2) gradual mass-dependent disruption, and (3) gradual mass-independent disruption. The model with mass-independent disruption provides a good, first-order description of these cluster populations, with g(M, tau) {proportional_to} M {sup beta}tau{sup g}amma, beta = -1.8 +- 0.2 and gamma = -0.8 +- 0.2, at least for clusters with ages tau {approx}< 10{sup 9} yr and masses M {approx}> 10{sup 3} M{sub sun} (more specifically, tau {approx}< 10{sup 7}(M/10{sup 2} M{sub sun}){sup 1.3} yr). This model predicts that the clusters should have a power-law luminosity function, dN/dL {proportional_to} L {sup -1.8}, in agreement with observations. The first two models, on the other hand, fare poorly when describing the observations, refuting previous claims that mass-dependent disruption of star clusters is observed in the LMC over the studied M-tau domain. Clusters in the SMC can be described by the same g(M, tau) distribution as for the LMC, but with smaller samples and hence larger uncertainties. The successful g(M, tau) model for clusters in the Magellanic Clouds is virtually the same as the one for clusters in the merging Antennae galaxies, but extends the domain of validity to lower masses and to older ages. This indicates that the dominant disruption processes are similar in these very different galaxies over at least tau {approx}< 10{sup 8} yr and possibly tau {approx}< 10{sup 9} yr. The mass functions for young clusters in the LMC are power laws, while that for ancient globular clusters is peaked. We show that the observed shapes of these mass functions are consistent with expectations from the simple evaporation model presented by McLaughlin and Fall.

  1. Rhenium Complexes and Clusters Supported on c-Al2O3: Effects of Rhenium Oxidation State and Rhenium Cluster Size on Catalytic Activity for n-butane Hydrogenolysis

    SciTech Connect (OSTI)

    Lobo Lapidus, R.; Gates, B

    2009-01-01

    Supported metals prepared from H{sub 3}Re{sub 3}(CO){sub 12} on {gamma}-Al{sub 2}O{sub 3} were treated under conditions that led to various rhenium structures on the support and were tested as catalysts for n-butane conversion in the presence of H{sub 2} in a flow reactor at 533 K and 1 atm. After use, two samples were characterized by X-ray absorption edge positions of approximately 5.6 eV (relative to rhenium metal), indicating that the rhenium was cationic and essentially in the same average oxidation state in each. But the Re-Re coordination numbers found by extended X-ray absorption fine structure spectroscopy (2.2 and 5.1) show that the clusters in the two samples were significantly different in average nuclearity despite their indistinguishable rhenium oxidation states. Spectra of a third sample after catalysis indicate approximately Re{sub 3} clusters, on average, and an edge position of 4.5 eV. Thus, two samples contained clusters approximated as Re{sub 3} (on the basis of the Re-Re coordination number), on average, with different average rhenium oxidation states. The data allow resolution of the effects of rhenium oxidation state and cluster size, both of which affect the catalytic activity; larger clusters and a greater degree of reduction lead to increased activity.

  2. Scaling relations and X-ray properties of moderate-luminosity galaxy clusters from 0.3 < z < 0.6 with XMM-Newton

    SciTech Connect (OSTI)

    Connor, Thomas; Donahue, Megan; Sun, Ming; Hoekstra, Henk; Mahdavi, Andisheh; Conselice, Christopher J.; McNamara, Brian

    2014-10-10

    We present new X-ray temperatures and improved X-ray luminosity estimates for 15 new and archival XMM-Newton observations of galaxy clusters at intermediate redshift with mass and luminosities near the galaxy group/cluster division (M{sub 2500}<2.410{sup 14} h{sub 70}{sup ?1} M{sub ?}, L < 2 10{sup 44} erg s{sup 1}, 0.3 < z < 0.6). These clusters have weak-lensing mass measurements based on Hubble Space Telescope observations of clusters representative of an X-ray-selected sample (the ROSAT 160SD survey). The angular resolution of XMM-Newton allows us to disentangle the emission of these galaxy clusters from nearby point sources, which significantly contaminated previous X-ray luminosity estimates for 6 of the 15 clusters. We extend cluster scaling relations between X-ray luminosity, temperature, and weak-lensing mass for low-mass, X-ray-selected clusters out to redshift ?0.45. These relations are important for cosmology and the astrophysics of feedback in galaxy groups and clusters. Our joint analysis with a sample of 50 clusters in a similar redshift range but with larger masses (M {sub 500} < 21.9 10{sup 14} M {sub ?}, 0.15 ? z ? 0.55) from the Canadian Cluster Comparison Project finds that within r {sub 2500}, M?L {sup 0.440.05}, T?L {sup 0.230.02}, and M?T {sup 1.90.2}. The estimated intrinsic scatter in the M-L relation for the combined sample is reduced to ?{sub log(M|L)} = 0.10, from ?{sub log} {sub (M|L)} = 0.26 with the original ROSAT measurements. We also find an intrinsic scatter for the T-L relation, ?{sub log} {sub (T|L)} = 0.07 0.01.

  3. Ionized cluster beam technology for material science

    SciTech Connect (OSTI)

    Takagi, Toshinori

    1997-06-20

    The most suitable kinetic energy range of ionized materials in film formation and epitaxial growth is from a few eV to a few hundreds eV, especially, less than about 100eV, when ions are used as a host. The main roles of ions in film formation are the effects due to their kinetic energy and the electronic charge effects which involve the effect to active film formation and the effect acceleration of chemical reactions. Therefore, it is important to develope the technology to transport large volume of a flux of ionized particles with an extremely low incident energy without any troubles due to the space charge effects and charge up problems on the surface. This is the exact motivation for us to have been developing the Ionized Cluster Beam (ICB) technology since 1972. By ICB technology materials (actually wide varieties of materials such as metal, semiconductor, magnetic material, insulator, organic material, etc.) are vaporized and ejected through a small hole nozzle into a high vacuum, where the vaporized material condenses into clusters with loosely coupled atoms with the sizes about from 100 to a few 1000 atoms (mainly 100-2000 atoms) by supercondensation phenomena due to the adiabatic expansion in this evaporation process through a small hole nozzle. In the ICB technology an atom in each cluster is ionized by irradiated by electron shower, and the ionized clusters are accelerated by electric field onto a substrate. The ionized clusters with neutral clusters impinged onto a substrate are spreaded separately into atoms migrating over the substrate, so that the surface migration energy of the impinged atoms, that is, surface diffusion energy are controlled by an incident energy of a cluster. In this report the theoretical and also experimental results of ICB technology are summarized.

  4. (Electronic structure and reactivities of transition metal clusters)

    SciTech Connect (OSTI)

    Not Available

    1992-01-01

    The following are reported: theoretical calculations (configuration interaction, relativistic effective core potentials, polyatomics, CASSCF); proposed theoretical studies (clusters of Cu, Ag, Au, Ni, Pt, Pd, Rh, Ir, Os, Ru; transition metal cluster ions; transition metal carbide clusters; bimetallic mixed transition metal clusters); reactivity studies on transition metal clusters (reactivity with H{sub 2}, C{sub 2}H{sub 4}, hydrocarbons; NO and CO chemisorption on surfaces). Computer facilities and codes to be used, are described. 192 refs, 13 figs.

  5. Revisiting benzene cluster cations for the chemical ionization of dimethyl sulfide and select volatile organic compounds

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

    Kim, M. J.; Zoerb, M. C.; Campbell, N. R.; Zimmermann, K. J.; Blomquist, B. W.; Huebert, B. J.; Bertram, T. H.

    2015-10-01

    Benzene cluster cations were revisited as a sensitive and selective reagent ion for the chemical ionization of dimethyl sulfide (DMS) and a select group of volatile organic compounds (VOCs). Laboratory characterization was performed using both a new set of compounds (i.e. DMS, ?-caryophyllene) as well as previously studied VOCs (i.e., isoprene, ?-pinene). Using a field deployable chemical ionization time-of-flight mass spectrometer (CI-ToFMS), benzene cluster cations demonstrated high sensitivity (> 1 ncps ppt?1) to DMS, isoprene, and ?-pinene standards. Parallel measurements conducted using a chemical-ionization quadrupole mass spectrometer, with a weaker electric field, demonstrated that ion-molecule reactions likely proceed through amorecombination of ligand-switching and direct charge transfer mechanisms. Laboratory tests suggest that benzene cluster cations may be suitable for the selective ionization of sesquiterpenes, where minimal fragmentation (R2=0.80) over a wide range of sampling conditions.less

  6. Sampling Report for May-June, 2014 WIPP Samples

    Office of Environmental Management (EM)

    UNCLASSIFIED iii Table of Contents WIPP Panel 7 Sampling May-June, 2014 ... 15 LLNL-TR-667001 Section 1 WIPP Panel 7 Sampling May-June, 2014 1. Summary of ...

  7. Dark Matter Searches with Cherenkov Telescopes: Nearby Dwarf Galaxies or Local Galaxy Clusters?

    SciTech Connect (OSTI)

    Sanchez-Conde, Miguel A.; Cannoni, Mirco; Zandanel, Fabio; Gomez, Mario E.; Prada, Francisco; /IAA, Granada

    2012-06-06

    In this paper, we compare dwarf galaxies and galaxy clusters in order to elucidate which object class is the best target for gamma-ray DM searches with imaging atmospheric Cherenkov telescopes (IACTs). We have built a mixed dwarfs+clusters sample containing some of the most promising nearby dwarf galaxies (Draco, Ursa Minor, Wilman 1 and Segue 1) and local galaxy clusters (Perseus, Coma, Ophiuchus, Virgo, Fornax, NGC 5813 and NGC 5846), and then compute their DM annihilation flux profiles by making use of the latest modeling of their DM density profiles. We also include in our calculations the effect of DM substructure. Willman 1 appears as the best candidate in the sample. However, its mass modeling is still rather uncertain, so probably other candidates with less uncertainties and quite similar fluxes, namely Ursa Minor and Segue 1, might be better options. As for galaxy clusters, Virgo represents the one with the highest flux. However, its large spatial extension can be a serious handicap for IACT observations and posterior data analysis. Yet, other local galaxy cluster candidates with more moderate emission regions, such as Perseus, may represent good alternatives. After comparing dwarfs and clusters, we found that the former exhibit annihilation flux profiles that, at the center, are roughly one order of magnitude higher than those of clusters, although galaxy clusters can yield similar, or even higher, integrated fluxes for the whole object once substructure is taken into account. Even when any of these objects are strictly point-like according to the properties of their annihilation signals, we conclude that dwarf galaxies are best suited for observational strategies based on the search of point-like sources, while galaxy clusters represent best targets for analyses that can deal with rather extended emissions. Finally, we study the detection prospects for present and future IACTs in the framework of the constrained minimal supersymmetric standard model. We

  8. Sampling Report for August 15, 2014 WIPP Samples

    Office of Environmental Management (EM)

    0 L L N L - X X X X - X X X X X Sampling Report for August 15, 2014 WIPP Samples UNCLASSIFIED Forensic Science Center December 19, 2014 Sampling Report for August 15 2014 WIPP Samples Lawrence Livermore National Laboratory UNCLASSIFIED ii Disclaimer This document was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor Lawrence Livermore National Security, LLC, nor any of their employees makes any warranty, expressed or

  9. Specified assurance level sampling procedure

    SciTech Connect (OSTI)

    Willner, O.

    1980-11-01

    In the nuclear industry design specifications for certain quality characteristics require that the final product be inspected by a sampling plan which can demonstrate product conformance to stated assurance levels. The Specified Assurance Level (SAL) Sampling Procedure has been developed to permit the direct selection of attribute sampling plans which can meet commonly used assurance levels. The SAL procedure contains sampling plans which yield the minimum sample size at stated assurance levels. The SAL procedure also provides sampling plans with acceptance numbers ranging from 0 to 10, thus, making available to the user a wide choice of plans all designed to comply with a stated assurance level.

  10. The galaxy cluster mid-infrared luminosity function at 1.3 < z < 3.2

    SciTech Connect (OSTI)

    Wylezalek, Dominika; Vernet, Joël; De Breuck, Carlos; Stern, Daniel; Brodwin, Mark; Galametz, Audrey; Gonzalez, Anthony H.; Jarvis, Matt; Hatch, Nina; Seymour, Nick; Stanford, Spencer A.

    2014-05-01

    We present 4.5 μm luminosity functions for galaxies identified in 178 candidate galaxy clusters at 1.3 < z < 3.2. The clusters were identified as Spitzer/Infrared Array Camera (IRAC) color-selected overdensities in the Clusters Around Radio-Loud AGN project, which imaged 420 powerful radio-loud active galactic nuclei (RLAGNs) at z > 1.3. The luminosity functions are derived for different redshift and richness bins, and the IRAC imaging reaches depths of m* + 2, allowing us to measure the faint end slopes of the luminosity functions. We find that α = –1 describes the luminosity function very well in all redshift bins and does not evolve significantly. This provides evidence that the rate at which the low mass galaxy population grows through star formation gets quenched and is replenished by in-falling field galaxies does not have a major net effect on the shape of the luminosity function. Our measurements for m* are consistent with passive evolution models and high formation redshifts (z{sub f} ∼ 3). We find a slight trend toward fainter m* for the richest clusters, implying that the most massive clusters in our sample could contain older stellar populations, yet another example of cosmic downsizing. Modeling shows that a contribution of a star-forming population of up to 40% cannot be ruled out. This value, found from our targeted survey, is significantly lower than the values found for slightly lower redshift, z ∼ 1, clusters found in wide-field surveys. The results are consistent with cosmic downsizing, as the clusters studied here were all found in the vicinity of RLAGNs—which have proven to be preferentially located in massive dark matter halos in the richest environments at high redshift—and they may therefore be older and more evolved systems than the general protocluster population.

  11. Revisiting benzene cluster cations for the chemical ionization of dimethyl sulfide and select volatile organic compounds

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

    Kim, Michelle J.; Zoerb, Matthew C.; Campbell, Nicole R.; Zimmermann, Kathryn J.; Blomquist, Byron W.; Huebert, Barry J.; Bertram, Timothy H.

    2016-04-05

    Here, benzene cluster cations were revisited as a sensitive and selective reagent ion for the chemical ionization of dimethyl sulfide (DMS) and a select group of volatile organic compounds (VOCs). Laboratory characterization was performed using both a new set of compounds (i.e., DMS, β-caryophyllene) as well as previously studied VOCs (i.e., isoprene, α-pinene). Using a field deployable chemical-ionization time-of-flight mass spectrometer (CI-ToFMS), benzene cluster cations demonstrated high sensitivity (> 1 ncps ppt−1) to DMS, isoprene, and α-pinene standards. Parallel measurements conducted using a chemical-ionization quadrupole mass spectrometer, with a much weaker electric field, demonstrated that ion–molecule reactions likely proceed through a combinationmore » of ligand-switching and direct charge transfer mechanisms. Laboratory tests suggest that benzene cluster cations may be suitable for the selective ionization of sesquiterpenes, where minimal fragmentation (< 25 %) was observed for the detection of β-caryophyllene, a bicyclic sesquiterpene. The in-field stability of benzene cluster cations using CI-ToFMS was examined in the marine boundary layer during the High Wind Gas Exchange Study (HiWinGS). The use of benzene cluster cation chemistry for the selective detection of DMS was validated against an atmospheric pressure ionization mass spectrometer, where measurements from the two instruments were highly correlated (R2 > 0.95, 10 s averages) over a wide range of sampling conditions.« less

  12. Dimensional scale effects on surface enhanced Raman scattering efficiency of self-assembled silver nanoparticle clusters

    SciTech Connect (OSTI)

    Fasolato, C.; Domenici, F. E-mail: paolo.postorino@roma1.infn.it; De Angelis, L.; Luongo, F.; Postorino, P. E-mail: paolo.postorino@roma1.infn.it; Sennato, S.; Mura, F.; Costantini, F.; Bordi, F.

    2014-08-18

    A study of the Surface Enhanced Raman Scattering (SERS) from micrometric metallic nanoparticle aggregates is presented. The sample is obtained from the self-assembly on glass slides of micro-clusters of silver nanoparticles (60 and 100 nm diameter), functionalized with the organic molecule 4-aminothiophenol in water solution. For nanoparticle clusters at the micron scale, a maximum enhancement factor of 10{sup 9} is estimated from the SERS over the Raman intensity ratio normalized to the single molecule contribution. Atomic force microscopy, correlated to spatially resolved Raman measurements, allows highlighting the connection between morphology and efficiency of the plasmonic system. The correlation between geometric features and SERS response of the metallic structures reveals a linear trend of the cluster maximum scattered intensity as a function of the surface area of the aggregate. On given clusters, the intensity turns out to be also influenced by the number of stacking planes of the aggregate, thus suggesting a plasmonic waveguide effect. The linear dependence results weakened for the largest area clusters, suggesting 30 μm{sup 2} as the upper limit for exploiting the coherence over large scale of the plasmonic response.

  13. Completion report for Well Cluster ER-20-6

    SciTech Connect (OSTI)

    1998-02-01

    The Well Cluster ER-20-6 drilling and completion project was conducted during February, March, and April of 1996 in support of the Nevada Environmental Restoration Project at the Nevada Test Site (NTS), Nye County, Nevada. This project is part of the DOE`s Underground Test Area (UGTA) subproject at the NTS. The primary UGTA tasks include collecting geological, geophysical, and hydrological data from new and existing wells to define groundwater quality as well as pathways and rates of groundwater migration at the NTS. A program of drilling wells near the sites of selected underground nuclear tests (near-field drilling) was implemented as part of the UGTA subproject to obtain site-specific data on the nature and extent of migration of radionuclides produced by an underground nuclear explosion. The ER-20-6 near-field drilling project was originally planned to be very similar to that recently conducted at Well Cluster ER-20-5, which was designed to obtain data on the existing hydrologic regime near the site of an underground nuclear explosion (IT, 1995; IT, 1996a). However, after further consideration of the goals of the near-field drilling program and the characteristics of the BULLION site, the TWG recommended that the ER-20-6 project be redesigned to accommodate a forced-gradient experiment. This proposed experiment is expected to yield more realistic estimates of transport parameters than can be deduced from sampling and testing natural groundwater flow systems.

  14. Supersonic Bare Metal Cluster Beams. Final Report

    DOE R&D Accomplishments [OSTI]

    Smalley, R. E.

    1997-10-14

    A major portion of the project involved elucidating the relation between reactivity and the electronic structure of transition-metal (TM) clusters of 2--200 atoms, which required the construction and continuous development of two principal apparati; the Fourier Transform-Ion Cyclotron Resonance (FT-ICR) apparatus, and Ultraviolet Photoelectron Spectroscopy (UPS). Together, these machines have enabled the most detailed probing of the structure and chemical reactivity of TM clusters. Clusters of all the transition metals were included in these studies. Fundamental aspects in chemisorption, reactivity, and heterogeneous catalysis have also become better understood as a result of these experiments for important classes of systems such as H{sub 2}, CO, and CO{sub 2} adsorbed onto clusters of many of the metals listed above. In particular, a correlation was found between reactivity of H{sub 2} with Fe, Co, and Ni clusters and differences between the cluster IP and EA. As recounted in a previous technical report, the DOE`s role in the initial discovery of fullerenes at Rice was central, and from the start investigations were made into metal atoms trapped in the fullerenes cage. More recently, the authors have discovered that 2--4 atoms of La, Y, or Sc can be produced by laser vaporization of composite graphite/metal-oxide disks. This work was largely motivated by the prospects of using such endohedral TM metals for their catalytic activity without the well-known difficulties of effective support media and lack of control over particle size. Thus, while it will certainly be important to discover ways to efficiently scale up production (e.g., the solar generation method explored with DOE support), the efforts have concentrated more on characterization, purification, and manipulation of doped fullerenes. For the past two years, much of the group`s effort has involved the production, purification, and characterization of carbon nanotubes.

  15. Groundwater Sampling | Open Energy Information

    Open Energy Info (EERE)

    500 mL), whereas analysis for stable isotopes that are present in greater abundance in natural samples requires less water to be sampled by a full order of magnitude (approximately...

  16. Geoscience Laboratory | Sample Preparation Laboratories

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

    preparation and other relatively straight-forward laboratory manipulations. These include buffer preparations, solid sample grinding, solution concentration, filtration, and...

  17. Comparison of galaxy clusters selected by weak-lensing, optical spectroscopy, and X-rays in the deep lens survey F2 field

    SciTech Connect (OSTI)

    Starikova, Svetlana; Jones, Christine; Forman, William R.; Vikhlinin, Alexey; Kurtz, Michael J.; Fabricant, Daniel G.; Murray, Stephen S.; Geller, Margaret J.; Dell'Antonio, Ian P.

    2014-05-10

    We compare galaxy clusters selected in Chandra and XMM-Newton X-ray observations of the 4 deg{sup 2} Deep Lens Survey (DLS) F2 field to the cluster samples previously selected in the same field from a sensitive weak-lensing shear map derived from the DLS and from a detailed galaxy redshift surveythe Smithsonian Hectospec Lensing Survey (SHELS). Our Chandra and XMM-Newton observations cover 1.6 deg{sup 2} of the DLS F2 field, including all 12 weak-lensing peaks above a signal-to-noise ratio of 3.5, along with 16 of the 20 SHELS clusters with published velocity dispersions >500 km s{sup 1}. We detect 26 extended X-ray sources in this area and confirm 23 of them as galaxy clusters using the optical imaging. Approximately 75% of clusters detected in either X-ray or spectroscopic surveys are found in both; these follow the previously established scaling relations between velocity dispersion, L {sub X}, and T {sub X}. A lower percentage, 60%, of clusters are in common between X-ray and DLS samples. With the exception of a high false-positive rate in the DLS weak-lensing search (5 out of 12 DLS candidates appear to be false), differences between the three cluster detection methods can be attributed primarily to observational uncertainties and intrinsic scatter between different observables and cluster mass.

  18. Variation of lattice constant and cluster formation in GaAsBi

    SciTech Connect (OSTI)

    Puustinen, J.; Schramm, A.; Guina, M.; Wu, M.; Luna, E.; Laukkanen, P.; Laitinen, M.; Sajavaara, T.

    2013-12-28

    We investigate the structural properties of GaAsBi layers grown by molecular beam epitaxy on GaAs at substrate temperatures between 220315 C. Irrespective of the growth temperature, the structures exhibited similar Bi compositions, and good overall crystal quality as deduced from X-Ray diffraction measurements. After thermal annealing at temperatures as low as 500 C, the GaAsBi layers grown at the lowest temperatures exhibited a significant reduction of the lattice constant. The lattice variation was significantly larger for Bi-containing samples than for Bi-free low-temperature GaAs samples grown as a reference. Rutherford backscattering spectrometry gave no evidence of Bi diffusing out of the layer during annealing. However, dark-field and Z-contrast transmission electron microscopy analyses revealed the formation of GaAsBi clusters with a Bi content higher than in the surrounding matrix, as well as the presence of metallic As clusters. The apparent reduction of the lattice constant can be explained by a two-fold process: the diffusion of the excess As incorporated within As{sub Ga} antisites to As clusters, and the reduction of the Bi content in the GaAs matrix due to diffusion of Bi to GaAsBi clusters. Diffusion of both As and Bi are believed to be assisted by the native point defects, which are present in the low-temperature as-grown material.

  19. RADIAL VELOCITIES FROM VLT-KMOS SPECTRA OF GIANT STARS IN THE GLOBULAR CLUSTER NGC6388

    SciTech Connect (OSTI)

    Lapenna, E.; Mucciarelli, A.; Lanzoni, B.; Ferraro, F. R.; Dalessandro, E. [Dipartimento di Fisica e Astronomia, Universit degli Studi di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); Origlia, L. [INAF-Osservatorio Astronomico di Bologna, Via Ranzani, 1, I-40127 Bologna (Italy); Valenti, E. [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei Mnchen (Germany); Cirasuolo, M. [Institute for Astronomy, University of Edinburgh and STFC, UK Astronomy Technology Center Royal Observatory, Blackford Hill, EH9 3HJ, Edinburgh (United Kingdom)

    2015-01-01

    We present new radial velocity measurements for 82 stars, members of the Galactic globular cluster (GC) NGC6388, obtained from ESO-VLT K-band Multi Object Spectrograph (KMOS) spectra acquired during the instrument Science Verification. The accuracy of the wavelength calibration is discussed and a number of tests of the KMOS response are presented. The cluster systemic velocity obtained (81.3 1.5 km s{sup 1}) is in very good agreement with previous determinations. While a hint of ordered rotation is found between 9'' and 20'' from the cluster center, where the distribution of radial velocities is clearly bimodal, more data are needed before drawing any firm conclusions. The acquired sample of radial velocities has also been used to determine the cluster velocity dispersion (VD) profile between ?9'' and 70'', supplementing previous measurements at r < 2'' and r > 60'' obtained with ESO-SINFONI and ESO-FLAMES spectroscopy, respectively. The new portion of the VD profile nicely matches the previous ones, better defining the knee of the distribution. The present work clearly shows the effectiveness of a deployable integral field unit in measuring the radial velocities of individual stars for determining the VD profile of Galactic GCs. It represents the pilot project for an ongoing large program with KMOS and FLAMES at the ESO-VLT, aimed at determining the next generation of VD and rotation profiles for a representative sample of GCs.

  20. Model catalysis by size-selected cluster deposition

    SciTech Connect (OSTI)

    Anderson, Scott

    2015-11-20

    This report summarizes the accomplishments during the last four years of the subject grant. Results are presented for experiments in which size-selected model catalysts were studied under surface science and aqueous electrochemical conditions. Strong effects of cluster size were found, and by correlating the size effects with size-dependent physical properties of the samples measured by surface science methods, it was possible to deduce mechanistic insights, such as the factors that control the rate-limiting step in the reactions. Results are presented for CO oxidation, CO binding energetics and geometries, and electronic effects under surface science conditions, and for the electrochemical oxygen reduction reaction, ethanol oxidation reaction, and for oxidation of carbon by water.

  1. POF-Darts: Geometric adaptive sampling for probability of failure

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

    Ebeida, Mohamed S.; Mitchell, Scott A.; Swiler, Laura P.; Romero, Vicente J.; Rushdi, Ahmad A.

    2016-06-18

    We introduce a novel technique, POF-Darts, to estimate the Probability Of Failure based on random disk-packing in the uncertain parameter space. POF-Darts uses hyperplane sampling to explore the unexplored part of the uncertain space. We use the function evaluation at a sample point to determine whether it belongs to failure or non-failure regions, and surround it with a protection sphere region to avoid clustering. We decompose the domain into Voronoi cells around the function evaluations as seeds and choose the radius of the protection sphere depending on the local Lipschitz continuity. As sampling proceeds, regions uncovered with spheres will shrink,more » improving the estimation accuracy. After exhausting the function evaluation budget, we build a surrogate model using the function evaluations associated with the sample points and estimate the probability of failure by exhaustive sampling of that surrogate. In comparison to other similar methods, our algorithm has the advantages of decoupling the sampling step from the surrogate construction one, the ability to reach target POF values with fewer samples, and the capability of estimating the number and locations of disconnected failure regions, not just the POF value. Furthermore, we present various examples to demonstrate the efficiency of our novel approach.« less

  2. Peeking Network States with Clustered Patterns

    SciTech Connect (OSTI)

    Kim, Jinoh; Sim, Alex

    2015-10-20

    Network traffic monitoring has long been a core element for effec- tive network management and security. However, it is still a chal- lenging task with a high degree of complexity for comprehensive analysis when considering multiple variables and ever-increasing traffic volumes to monitor. For example, one of the widely con- sidered approaches is to scrutinize probabilistic distributions, but it poses a scalability concern and multivariate analysis is not gen- erally supported due to the exponential increase of the complexity. In this work, we propose a novel method for network traffic moni- toring based on clustering, one of the powerful deep-learning tech- niques. We show that the new approach enables us to recognize clustered results as patterns representing the network states, which can then be utilized to evaluate “similarity” of network states over time. In addition, we define a new quantitative measure for the similarity between two compared network states observed in dif- ferent time windows, as a supportive means for intuitive analysis. Finally, we demonstrate the clustering-based network monitoring with public traffic traces, and show that the proposed approach us- ing the clustering method has a great opportunity for feasible, cost- effective network monitoring.

  3. Sampling Report for May-June, 2014 WIPP Samples

    Office of Environmental Management (EM)

    1 L L N L - X X X X - X X X X X Sampling Report for May- June, 2014 WIPP Samples UNCLASSIFIED Forensic Science Center January 8, 2015 Sampling Report for May-June, 2014 WIPP Samples Lawrence Livermore National Laboratory UNCLASSIFIED ii Disclaimer This document was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor Lawrence Livermore National Security, LLC, nor any of their employees makes any warranty, expressed or

  4. Testing chameleon gravity with the Coma cluster

    SciTech Connect (OSTI)

    Terukina, Ayumu; Yamamoto, Kazuhiro; Lombriser, Lucas; Bacon, David; Koyama, Kazuya; Nichol, Robert C. E-mail: lucas.lombriser@port.ac.uk E-mail: david.bacon@port.ac.uk E-mail: bob.nichol@port.ac.uk

    2014-04-01

    We propose a novel method to test the gravitational interactions in the outskirts of galaxy clusters. When gravity is modified, this is typically accompanied by the introduction of an additional scalar degree of freedom, which mediates an attractive fifth force. The presence of an extra gravitational coupling, however, is tightly constrained by local measurements. In chameleon modifications of gravity, local tests can be evaded by employing a screening mechanism that suppresses the fifth force in dense environments. While the chameleon field may be screened in the interior of the cluster, its outer region can still be affected by the extra force, introducing a deviation between the hydrostatic and lensing mass of the cluster. Thus, the chameleon modification can be tested by combining the gas and lensing measurements of the cluster. We demonstrate the operability of our method with the Coma cluster, for which both a lensing measurement and gas observations from the X-ray surface brightness, the X-ray temperature, and the Sunyaev-Zel'dovich effect are available. Using the joint observational data set, we perform a Markov chain Monte Carlo analysis of the parameter space describing the different profiles in both the Newtonian and chameleon scenarios. We report competitive constraints on the chameleon field amplitude and its coupling strength to matter. In the case of f(R) gravity, corresponding to a specific choice of the coupling, we find an upper bound on the background field amplitude of |f{sub R0}| < 6 10{sup ?5}, which is currently the tightest constraint on cosmological scales.

  5. THERMODYNAMICS OF THE COMA CLUSTER OUTSKIRTS

    SciTech Connect (OSTI)

    Simionescu, A.; Werner, N.; Urban, O.; Allen, S. W.; Fabian, A. C.; Sanders, J. S.; Walker, S. A.; Mantz, A.; Matsushita, K.; Sasaki, T.; Sato, T.; Nulsen, P. E. J.; Takei, Y.

    2013-09-20

    We present results from a large mosaic of Suzaku observations of the Coma Cluster, the nearest and X-ray brightest hot ({approx}8 keV), dynamically active, non-cool core system, focusing on the thermodynamic properties of the intracluster medium on large scales. For azimuths not aligned with an infalling subcluster toward the southwest, our measured temperature and X-ray brightness profiles exhibit broadly consistent radial trends, with the temperature decreasing from about 8.5 keV at the cluster center to about 2 keV at a radius of 2 Mpc, which is the edge of our detection limit. The southwest merger significantly boosts the surface brightness, allowing us to detect X-ray emission out to {approx}2.2 Mpc along this direction. Apart from the southwestern infalling subcluster, the surface brightness profiles show multiple edges around radii of 30-40 arcmin. The azimuthally averaged temperature profile, as well as the deprojected density and pressure profiles, all show a sharp drop consistent with an outwardly-propagating shock front located at 40 arcmin, corresponding to the outermost edge of the giant radio halo observed at 352 MHz with the Westerbork Synthesis Radio Telescope. The shock front may be powering this radio emission. A clear entropy excess inside of r{sub 500} reflects the violent merging events linked with these morphological features. Beyond r{sub 500}, the entropy profiles of the Coma Cluster along the relatively relaxed directions are consistent with the power-law behavior expected from simple models of gravitational large-scale structure formation. The pressure is also in agreement at these radii with the expected values measured from Sunyaev-Zel'dovich data from the Planck satellite. However, due to the large uncertainties associated with the Coma Cluster measurements, we cannot yet exclude an entropy flattening in this system consistent with that seen in more relaxed cool core clusters.

  6. ACTIVE GALACTIC NUCLEI IN GROUPS AND CLUSTERS OF GALAXIES: DETECTION AND HOST MORPHOLOGY

    SciTech Connect (OSTI)

    Arnold, Timothy J.; Martini, Paul; Mulchaey, John S.; Berti, Angela; Jeltema, Tesla E. E-mail: martini@astronomy.ohio-state.ed E-mail: tesla@ucolick.or

    2009-12-20

    The incidence and properties of active galactic nuclei (AGNs) in the field, groups, and clusters can provide new information about how these objects are triggered and fueled, similar to how these environments have been employed to study galaxy evolution. We have obtained new XMM-Newton observations of seven X-ray selected groups and poor clusters with 0.02 < z < 0.06 for comparison with previous samples that mostly included rich clusters and optically selected groups. Our final sample has ten groups and six clusters in this low-redshift range (split at a velocity dispersion of sigma = 500 kms{sup -1}). We find that the X-ray selected AGN fraction increases from f{sub A} (L{sub X} >= 10{sup 41}; M{sub R} <= M*{sub R} + 1) = 0.047{sup +0.023}{sub -0.016} in clusters to 0.091{sup +0.049}{sub -0.034} for the groups (85% significance), or a factor of 2, for AGN above an 0.3-8 keV X-ray luminosity of 10{sup 41}ergs{sup -1} hosted by galaxies more luminous than M*{sub R} + 1. The trend is similar, although less significant, for a lower-luminosity host threshold of M{sub R} = -20 mag. For many of the groups in the sample, we have also identified AGN via standard emission-line diagnostics and find that these AGNs are nearly disjoint from the X-ray selected AGN. Because there are substantial differences in the morphological mix of galaxies between groups and clusters, we have also measured the AGN fraction for early-type galaxies alone to determine if the differences are directly due to environment, or indirectly due to the change in the morphological mix. We find that the AGN fraction in early-type galaxies is also lower in clusters f{sub A,n>}={sub 2.5}(L{sub X} >= 10{sup 41}; M{sub R} <= M*{sub R} + 1) = 0.048{sup +0.028}{sub -0.019} compared to 0.119{sup +0.064}{sub -0.044} for the groups (92% significance), a result consistent with the hypothesis that the change in AGN fraction is directly connected to environment.

  7. Acceptance sampling using judgmental and randomly selected samples

    SciTech Connect (OSTI)

    Sego, Landon H.; Shulman, Stanley A.; Anderson, Kevin K.; Wilson, John E.; Pulsipher, Brent A.; Sieber, W. Karl

    2010-09-01

    We present a Bayesian model for acceptance sampling where the population consists of two groups, each with different levels of risk of containing unacceptable items. Expert opinion, or judgment, may be required to distinguish between the high and low-risk groups. Hence, high-risk items are likely to be identifed (and sampled) using expert judgment, while the remaining low-risk items are sampled randomly. We focus on the situation where all observed samples must be acceptable. Consequently, the objective of the statistical inference is to quantify the probability that a large percentage of the unsampled items in the population are also acceptable. We demonstrate that traditional (frequentist) acceptance sampling and simpler Bayesian formulations of the problem are essentially special cases of the proposed model. We explore the properties of the model in detail, and discuss the conditions necessary to ensure that required samples sizes are non-decreasing function of the population size. The method is applicable to a variety of acceptance sampling problems, and, in particular, to environmental sampling where the objective is to demonstrate the safety of reoccupying a remediated facility that has been contaminated with a lethal agent.

  8. Field Observation GoAmazon Neutral cluster Air Ion Spectrometer...

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

    of the Green Ocean Amazon: Neutral Cluster Air Ion Spectrometer (NAIS) Final Campaign ... DOESC-ARM-15-060 Field Observation of the Green Ocean Amazon: Neutral Cluster Air Ion ...

  9. Spatial clustering of pixels of a multispectral image

    DOE Patents [OSTI]

    Conger, James Lynn

    2014-08-19

    A method and system for clustering the pixels of a multispectral image is provided. A clustering system computes a maximum spectral similarity score for each pixel that indicates the similarity between that pixel and the most similar neighboring. To determine the maximum similarity score for a pixel, the clustering system generates a similarity score between that pixel and each of its neighboring pixels and then selects the similarity score that represents the highest similarity as the maximum similarity score. The clustering system may apply a filtering criterion based on the maximum similarity score so that pixels with similarity scores below a minimum threshold are not clustered. The clustering system changes the current pixel values of the pixels in a cluster based on an averaging of the original pixel values of the pixels in the cluster.

  10. OpenCL now Available on Dirac GPU Cluster

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

    OpenCL now Available on Dirac GPU Cluster OpenCL now Available on Dirac GPU Cluster October 30, 2013 by Francesca Verdier As requested by many Dirac users, NERSC is migrating Dirac...

  11. Dirac GPU Cluster to be Retired December 12

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

    Dirac GPU Cluster to be Retired December 12 Dirac GPU Cluster to be Retired December 12 November 12, 2014 by Francesca Verdier As previously announced, the Dirac GPU testbed will...

  12. Sample page | Open Energy Information

    Open Energy Info (EERE)

    Sample pages; Help pages; References Francis C. Monastero. 2002. An overview of industry-military cooperation in the development of power operations at the Coso...

  13. Chemical Resources | Sample Preparation Laboratories

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

    Chemical Resources Chemical Inventory All Sample Preparation Labs are stocked with an assortment of common solvents, acids, bases, buffers, and other reagents. See our Chemical ...

  14. Gas Sampling | Open Energy Information

    Open Energy Info (EERE)

    of geothermometric calculations and geochemical modeling of the data. In the case of gas flux sampling, different measurement techniques and devices may disrupt or alter the...

  15. NREL: Process Development and Integration Laboratory - Silicon Cluster Tool

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

    Capabilities Silicon Cluster Tool Capabilities Photo of a cylindrical metal chamber surrounded by numerous other smaller cylindrical or rectangular chambers. Each tool has several flanges and is typically held within a metal frame or rack. A computer is on a table in front of a cabinet of electronic equipment. Silicon cluster tool in the Process Development and Integration Laboratory. The Silicon cluster tool within the Process Development and Integration Laboratory is a 10-port cluster tool

  16. Topological one-way quantum computation on verified logical cluster...

    Office of Scientific and Technical Information (OSTI)

    NOISE; QUANTUM COMPUTERS; QUBITS; STAR CLUSTERS; THREE-DIMENSIONAL CALCULATIONS; TOPOLOGY; VERIFICATION COMPUTERS; INFORMATION; MATHEMATICS; QUANTUM INFORMATION Word Cloud ...

  17. Consistent use of type Ia supernovae highly magnified by galaxy clusters to constrain the cosmological parameters

    SciTech Connect (OSTI)

    Zitrin, Adi [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States); Redlich, Matthias [Universitt Heidelberg, Zentrum fr Astronomie, Institut fr Theoretische Astrophysik, Philosophenweg 12, D-69120 Heidelberg (Germany); Broadhurst, Tom, E-mail: adizitrin@gmail.com [Department of Theoretical Physics, University of Basque Country UPV/EHU, Bilbao (Spain)

    2014-07-01

    We discuss how Type Ia supernovae (SNe) strongly magnified by foreground galaxy clusters should be self-consistently treated when used in samples fitted for the cosmological parameters. While the cluster lens magnification of a SN can be well constrained from sets of multiple images of various background galaxies with measured redshifts, its value is typically dependent on the fiducial set of cosmological parameters used to construct the mass model. In such cases, one should not naively demagnify the observed SN luminosity by the model magnification into the expected Hubble diagram, which would create a bias, but instead take into account the cosmological parameters a priori chosen to construct the mass model. We quantify the effect and find that a systematic error of typically a few percent, up to a few dozen percent per magnified SN may be propagated onto a cosmological parameter fit unless the cosmology assumed for the mass model is taken into account (the bias can be even larger if the SN is lying very near the critical curves). We also simulate how such a bias propagates onto the cosmological parameter fit using the Union2.1 sample supplemented with strongly magnified SNe. The resulting bias on the deduced cosmological parameters is generally at the few percent level, if only few biased SNe are included, and increases with the number of lensed SNe and their redshift. Samples containing magnified Type Ia SNe, e.g., from ongoing cluster surveys, should readily account for this possible bias.

  18. Environmental surveillance master sampling schedule

    SciTech Connect (OSTI)

    Bisping, L.E.

    1995-02-01

    Environmental surveillance of the Hanford Site and surrounding areas is conducted by the Pacific Northwest Laboratory (PNL) for the U.S. Department of Energy (DOE). This document contains the planned 1994 schedules for routine collection of samples for the Surface Environmental Surveillance Project (SESP), Drinking Water Project, and Ground-Water Surveillance Project. Samples are routinely collected for the SESP and analyzed to determine the quality of air, surface water, soil, sediment, wildlife, vegetation, foodstuffs, and farm products at Hanford Site and surrounding communities. The responsibility for monitoring onsite drinking water falls outside the scope of the SESP. PNL conducts the drinking water monitoring project concurrent with the SESP to promote efficiency and consistency, utilize expertise developed over the years, and reduce costs associated with management, procedure development, data management, quality control, and reporting. The ground-water sampling schedule identifies ground-water sampling .events used by PNL for environmental surveillance of the Hanford Site. Sampling is indicated as annual, semi-annual, quarterly, or monthly in the sampling schedule. Some samples are collected and analyzed as part of ground-water monitoring and characterization programs at Hanford (e.g. Resources Conservation and Recovery Act (RCRA), Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), or Operational). The number of samples planned by other programs are identified in the sampling schedule by a number in the analysis column and a project designation in the Cosample column. Well sampling events may be merged to avoid redundancy in cases where sampling is planned by both-environmental surveillance and another program.

  19. Computer System, Cluster, and Networking Summer Institute Program Description

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

    System, Cluster, and Networking Summer Institute Program Description The Computer System, Cluster, and Networking Summer Institute (CSCNSI) is a focused technical enrichment program targeting third-year college undergraduate students currently engaged in a computer science, computer engineering, or similar major. The program emphasizes practical skill development in setting up, configuring, administering, testing, monitoring, and scheduling computer systems, supercomputer clusters, and computer

  20. GLOBULAR CLUSTER POPULATIONS: FIRST RESULTS FROM S{sup 4}G EARLY-TYPE GALAXIES

    SciTech Connect (OSTI)

    Zaritsky, Dennis; Aravena, Manuel; Athanassoula, E.; Bosma, Albert; Comern, Sbastien; Laine, Jarkko; Laurikainen, Eija; Salo, Heikki; Elmegreen, Bruce G.; Erroz-Ferrer, Santiago; Knapen, Johan H.; Gadotti, Dimitri A.; Muoz-Mateos, Juan Carlos; Hinz, Joannah L.; Ho, Luis C.; Holwerda, Benne; Sheth, Kartik

    2015-02-01

    Using 3.6 ?m images of 97 early-type galaxies, we develop and verify methodology to measure globular cluster populations from the S{sup 4}G survey images. We find that (1) the ratio, T {sub N}, of the number of clusters, N {sub CL}, to parent galaxy stellar mass, M {sub *}, rises weakly with M {sub *} for early-type galaxies with M {sub *} > 10{sup 10} M {sub ?} when we calculate galaxy masses using a universal stellar initial mass function (IMF) but that the dependence of T {sub N} on M {sub *} is removed entirely once we correct for the recently uncovered systematic variation of IMF with M {sub *}; and (2) for M {sub *} < 10{sup 10} M {sub ?}, there is no trend between N {sub CL} and M {sub *}, the scatter in T {sub N} is significantly larger (approaching two orders of magnitude), and there is evidence to support a previous, independent suggestion of two families of galaxies. The behavior of N {sub CL} in the lower-mass systems is more difficult to measure because these systems are inherently cluster-poor, but our results may add to previous evidence that large variations in cluster formation and destruction efficiencies are to be found among low-mass galaxies. The average fraction of stellar mass in clusters is ?0.0014 for M {sub *} > 10{sup 10} M {sub ?} and can be as large as ?0.02 for less massive galaxies. These are the first results from the S{sup 4}G sample of galaxies and will be enhanced by the sample of early-type galaxies now being added to S{sup 4}G and complemented by the study of later-type galaxies within S{sup 4}G.

  1. THE DETAILED CHEMICAL PROPERTIES OF M31 STAR CLUSTERS. I. Fe, ALPHA AND LIGHT ELEMENTS

    SciTech Connect (OSTI)

    Colucci, Janet E.; Bernstein, Rebecca A.; Cohen, Judith G.

    2014-12-20

    We present ages, [Fe/H] and abundances of the α elements Ca I, Si I, Ti I, Ti II, and light elements Mg I, Na I, and Al I for 31 globular clusters (GCs) in M31, which were obtained from high-resolution, high signal-to-noise ratio >60 echelle spectra of their integrated light (IL). All abundances and ages are obtained using our original technique for high-resolution IL abundance analysis of GCs. This sample provides a never before seen picture of the chemical history of M31. The GCs are dispersed throughout the inner and outer halo, from 2.5 kpc < R {sub M31} < 117 kpc. We find a range of [Fe/H] within 20 kpc of the center of M31, and a constant [Fe/H] ∼ – 1.6 for the outer halo clusters. We find evidence for at least one massive GC in M31 with an age between 1 and 5 Gyr. The α-element ratios are generally similar to the Milky Way GC and field star ratios. We also find chemical evidence for a late-time accretion origin for at least one cluster, which has a different abundance pattern than other clusters at similar metallicity. We find evidence for star-to-star abundance variations in Mg, Na, and Al in the GCs in our sample, and find correlations of Ca, Mg, Na, and possibly Al abundance ratios with cluster luminosity and velocity dispersion, which can potentially be used to constrain GC self-enrichment scenarios. Data presented here were obtained with the HIRES echelle spectrograph on the Keck I telescope.

  2. 200 area TEDF sample schedule

    SciTech Connect (OSTI)

    Brown, M.J.

    1995-03-22

    This document summarizes the sampling criteria associated with the 200 Area Treatment Effluent Facility (TEDF) that are needed to comply with the requirements of the Washington State Discharge Permit No. WA ST 4502 and good engineering practices at the generator streams that feed into TEDF. In addition, this document Identifies the responsible parties for both sampling and data transference.

  3. Sample push-out fixture

    DOE Patents [OSTI]

    Biernat, John L.

    2002-11-05

    This invention generally relates to the remote removal of pelletized samples from cylindrical containment capsules. V-blocks are used to receive the samples and provide guidance to push out rods. Stainless steel liners fit into the v-channels on the v-blocks which permits them to be remotely removed and replaced or cleaned to prevent cross contamination between capsules and samples. A capsule holder securely holds the capsule while allowing manual up/down and in/out movement to align each sample hole with the v-blocks. Both end sections contain identical v-blocks; one that guides the drive out screw and rods or manual push out rods and the other to receive the samples as they are driven out of the capsule.

  4. SIMILARITIES IN POPULATIONS OF STAR CLUSTERS

    SciTech Connect (OSTI)

    Fall, S. Michael; Chandar, Rupali E-mail: rupali.chandar@utoledo.edu

    2012-06-20

    We compare the observed mass functions and age distributions of star clusters in six well-studied galaxies: the Milky Way, Magellanic Clouds, M83, M51, and Antennae. In combination, these distributions span wide ranges of mass and age: 10{sup 2} {approx}< M/M{sub Sun} {approx}< 10{sup 6} and 10{sup 6} {approx}< {tau}/yr {approx}< 10{sup 9}. We confirm that the distributions are well represented by power laws: dN/dM{proportional_to}M{sup {beta}} with {beta} Almost-Equal-To -1.9 and dN/d{tau}{proportional_to}{tau}{sup {gamma}} with {gamma} Almost-Equal-To -0.8. The mass and age distributions are approximately independent of each other, ruling out simple models of mass-dependent disruption. As expected, there are minor differences among the exponents at a level close to the true uncertainties, {epsilon}{sub {beta}} {approx} {epsilon}{sub {gamma}} {approx} 0.1-0.2. However, the overwhelming impression is the similarity of the mass functions and age distributions of clusters in these different galaxies, including giant and dwarf, quiescent and interacting galaxies. This is an important empirical result, justifying terms such as 'universal' or 'quasi-universal'. We provide a partial theoretical explanation for these observations in terms of physical processes operating during the formation and disruption of the clusters, including star formation and feedback, subsequent stellar mass loss, and tidal interactions with passing molecular clouds. A full explanation will require additional information about the molecular clumps and star clusters in galaxies beyond the Milky Way.

  5. Visualization Clusters | Argonne Leadership Computing Facility

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

    Analytics and Visualization Visualization Cluster Cooley The primary purpose of Cooley is to analyze and visualize data produced on Mira. Equipped with state-of-the-art graphics processing units (GPUs), Cooley converts computational data from Mira into high-resolution visual representations. The resulting images, videos, and animations help users to better analyze and understand the data generated by Mira. Cooley can also be used for statistical analysis, helping to pinpoint trends in the

  6. Coscheduling Technique for Symmetric Multiprocessor Clusters

    SciTech Connect (OSTI)

    Yoo, A B; Jette, M A

    2000-09-18

    Coscheduling is essential for obtaining good performance in a time-shared symmetric multiprocessor (SMP) cluster environment. However, the most common technique, gang scheduling, has limitations such as poor scalability and vulnerability to faults mainly due to explicit synchronization between its components. A decentralized approach called dynamic coscheduling (DCS) has been shown to be effective for network of workstations (NOW), but this technique is not suitable for the workloads on a very large SMP-cluster with thousands of processors. Furthermore, its implementation can be prohibitively expensive for such a large-scale machine. IN this paper, they propose a novel coscheduling technique based on the DCS approach which can achieve coscheduling on very large SMP-clusters in a scalable, efficient, and cost-effective way. In the proposed technique, each local scheduler achieves coscheduling based upon message traffic between the components of parallel jobs. Message trapping is carried out at the user-level, eliminating the need for unsupported hardware or device-level programming. A sending process attaches its status to outgoing messages so local schedulers on remote nodes can make more intelligent scheduling decisions. Once scheduled, processes are guaranteed some minimum period of time to execute. This provides an opportunity to synchronize the parallel job's components across all nodes and achieve good program performance. The results from a performance study reveal that the proposed technique is a promising approach that can reduce response time significantly over uncoordinated time-sharing and batch scheduling.

  7. MEASURING THE MASS DISTRIBUTION IN GALAXY CLUSTERS

    SciTech Connect (OSTI)

    Geller, Margaret J.; Diaferio, Antonaldo; Rines, Kenneth J.; Serra, Ana Laura E-mail: diaferio@ph.unito.it E-mail: serra@to.infn.it

    2013-02-10

    Cluster mass profiles are tests of models of structure formation. Only two current observational methods of determining the mass profile, gravitational lensing, and the caustic technique are independent of the assumption of dynamical equilibrium. Both techniques enable the determination of the extended mass profile at radii beyond the virial radius. For 19 clusters, we compare the mass profile based on the caustic technique with weak lensing measurements taken from the literature. This comparison offers a test of systematic issues in both techniques. Around the virial radius, the two methods of mass estimation agree to within {approx}30%, consistent with the expected errors in the individual techniques. At small radii, the caustic technique overestimates the mass as expected from numerical simulations. The ratio between the lensing profile and the caustic mass profile at these radii suggests that the weak lensing profiles are a good representation of the true mass profile. At radii larger than the virial radius, the extrapolated Navarro, Frenk and White fit to the lensing mass profile exceeds the caustic mass profile. Contamination of the lensing profile by unrelated structures within the lensing kernel may be an issue in some cases; we highlight the clusters MS0906+11 and A750, superposed along the line of sight, to illustrate the potential seriousness of contamination of the weak lensing signal by these unrelated structures.

  8. Structural properties of small rhodium clusters

    SciTech Connect (OSTI)

    Soon, Yee Yeen; Yoon, Tiem Leong; Lim, Thong Leng

    2015-04-24

    We report a systematic study of the structural properties of rhodium clusters at the atomistic level. A novel global-minimum search algorithm, known as parallel tempering multicanonical basin hopping plus genetic algorithm (PTMBHGA), is used to obtain the geometrical structures with lowest minima at the semi-empirical level where Gupta potential is used to describe the atomic interaction among the rhodium atoms. These structures are then re-optimized at the density functional theory (DFT) level with exchange-correlation energy approximated by Perdew-Burke-Ernzerhof (PBE) generalized gradient approximation (GGA). The structures are optimized for different spin multiplicities. The ones with lowest energies will be taken as ground-state structures. In most cases, we observe only minor changes in the geometry and bond length of the clusters as a result of DFT-level re-optimization. Only in some limited cases, the initial geometries obtained from the PTMBHGA are modified by the re-optimization. The variation of structural properties, such as ground-state geometry, symmetry and binding energy, with respect to the cluster size is studied and agreed well with other results available in the literature.

  9. Sample Preparation Laboratory Training - Course 204 | Sample Preparation

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

    Laboratories Sample Preparation Laboratory Training - Course 204 Who Should Attend This course is mandatory for: SLAC employees and non-employees who need unescorted access to SSRL or LCLS Sample Preparation Laboratories Note: This course may be taken in lieu of Course 199, Laboratory CHP training for SLAC employees. Prerequisites 115 - General Employee Radiological Training (GERT) Take Training Please see the notes section below for information on how to take this training. Course Details

  10. A VLT/FLAMES STUDY OF THE PECULIAR INTERMEDIATE-AGE LARGE MAGELLANIC CLOUD STAR CLUSTER NGC 1846. I. KINEMATICS

    SciTech Connect (OSTI)

    Mackey, A. D.; Da Costa, G. S.; Yong, D.; Ferguson, A. M. N.

    2013-01-01

    In this paper we present high-resolution VLT/FLAMES observations of red giant stars in the massive intermediate-age Large Magellanic Cloud star cluster NGC 1846, which, on the basis of its extended main-sequence turnoff (EMSTO), possesses an internal age spread of Almost-Equal-To 300 Myr. We describe in detail our target selection and data reduction procedures, and construct a sample of 21 stars possessing radial velocities indicating their membership of NGC 1846 at high confidence. We consider high-resolution spectra of the planetary nebula Mo-17, and conclude that this object is also a member of the cluster. Our measured radial velocities allow us to conduct a detailed investigation of the internal kinematics of NGC 1846, the first time this has been done for an EMSTO system. The key result of this work is that the cluster exhibits a significant degree of systemic rotation, of a magnitude comparable to the mean velocity dispersion. Using an extensive suite of Monte Carlo models we demonstrate that, despite our relatively small sample size and the substantial fraction of unresolved binary stars in the cluster, the rotation signal we detect is very likely to be genuine. Our observations are in qualitative agreement with the predictions of simulations modeling the formation of multiple populations of stars in globular clusters, where a dynamically cold, rapidly rotating second generation is a common feature. NGC 1846 is less than one relaxation time old, so any dynamical signatures encoded during its formation ought to remain present.

  11. KINEMATICS OF OUTER HALO GLOBULAR CLUSTERS IN M31

    SciTech Connect (OSTI)

    Veljanoski, J.; Ferguson, A. M. N.; Bernard, E. J.; Penarrubia, J.; Mackey, A. D.; Huxor, A. P.; Irwin, M. J.; Chapman, S. C.; Cote, P.; Tanvir, N. R.; McConnachie, A.; Ibata, R. A.; Martin, N. F.; Fardal, M.; Lewis, G. F.

    2013-05-10

    We present the first kinematic analysis of the far outer halo globular cluster (GC) population in the Local Group galaxy M31. Our sample contains 53 objects with projected radii of {approx}20-130 kpc, 44 of which have no previous spectroscopic information. GCs with projected radii {approx}> 30 kpc are found to exhibit net rotation around the minor axis of M31, in the same sense as the inner GCs, albeit with a smaller amplitude of 79 {+-} 19 km s{sup -1}. The rotation-corrected velocity dispersion of the full halo GC sample is 106 {+-} 12 km s{sup -1}, which we observe to decrease with increasing projected radius. We find compelling evidence for kinematic coherence among GCs that project on top of halo substructure, including a clear signature of infall for GCs lying along the northwest stream. Using the tracer mass estimator, we estimate the dynamical mass of M31 within 200 kpc to be M{sub M31} = (1.2-1.5) {+-} 0.2 Multiplication-Sign 10{sup 12} M{sub Sun }. This value is highly dependent on the chosen model and assumptions within.

  12. Thermal entanglement of spins in mean-field clusters

    SciTech Connect (OSTI)

    Asoudeh, M.; Karimipour, V.

    2006-06-15

    We determine thermal entanglement in mean-field clusters of N spin one-half particles interacting via the anisotropic Heisenberg interaction, with and without external magnetic field. For the xxx cluster in the absence of magnetic field we prove that only the N=2 ferromagnetic cluster shows entanglement. An external magnetic field B can only entangle xxx antiferromagnetic clusters in certain regions of the B-T plane. On the other hand, the xxz clusters of size N>2 are entangled only when the interaction is ferromagnetic. Detailed dependence of the entanglement on various parameters is investigated in each case.

  13. Incremental Clustering Algorithm For Earth Science Data Mining

    SciTech Connect (OSTI)

    Vatsavai, Raju

    2009-01-01

    Remote sensing data plays a key role in understanding the complex geographic phenomena. Clustering is a useful tool in discovering interesting patterns and structures within the multivariate geospatial data. One of the key issues in clustering is the specication of appropriate number of clusters, which is not obvious in many practical situations. In this paper we provide an extension of G-means algorithm which automatically learns the number of clusters present in the data and avoids over estimation of the number of clusters. Experimental evaluation on simulated and remotely sensed image data shows the effectiveness of our algorithm.

  14. Environmental surveillance master sampling schedule

    SciTech Connect (OSTI)

    Bisping, L.E.

    1991-01-01

    Environmental surveillance of the Hanford Site and surrounding areas is conducted by the Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE). This document contains the planned schedule for routine sample collection for the Surface Environmental Surveillance Project (SESP) and Ground-Water Monitoring Project. The routine sampling plan for the SESP has been revised this year to reflect changing site operations and priorities. Some sampling previously performed at least annually has been reduced in frequency, and some new sampling to be performed at a less than annual frequency has been added. Therefore, the SESP schedule reflects sampling to be conducted in calendar year 1991 as well as future years. The ground-water sampling schedule is for 1991. This schedule is subject to modification during the year in response to changes in Site operation, program requirements, and the nature of the observed results. Operational limitations such as weather, mechanical failures, sample availability, etc., may also require schedule modifications. Changes will be documented in the respective project files, but this plan will not be reissued. The purpose of these monitoring projects is to evaluate levels of radioactive and nonradioactive pollutants in the Hanford evirons.

  15. Duplex sampling apparatus and method

    DOE Patents [OSTI]

    Brown, Paul E.; Lloyd, Robert

    1992-01-01

    An improved apparatus is provided for sampling a gaseous mixture and for measuring mixture components. The apparatus includes two sampling containers connected in series serving as a duplex sampling apparatus. The apparatus is adapted to independently determine the amounts of condensable and noncondensable gases in admixture from a single sample. More specifically, a first container includes a first port capable of selectively connecting to and disconnecting from a sample source and a second port capable of selectively connecting to and disconnecting from a second container. A second container also includes a first port capable of selectively connecting to and disconnecting from the second port of the first container and a second port capable of either selectively connecting to and disconnecting from a differential pressure source. By cooling a mixture sample in the first container, the condensable vapors form a liquid, leaving noncondensable gases either as free gases or dissolved in the liquid. The condensed liquid is heated to drive out dissolved noncondensable gases, and all the noncondensable gases are transferred to the second container. Then the first and second containers are separated from one another in order to separately determine the amount of noncondensable gases and the amount of condensable gases in the sample.

  16. Landscape Characterization and Representativeness Analysis for Understanding Sampling Network Coverage

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Maddalena, Damian; Hoffman, Forrest; Kumar, Jitendra; Hargrove, William

    2014-08-01

    Sampling networks rarely conform to spatial and temporal ideals, often comprised of network sampling points which are unevenly distributed and located in less than ideal locations due to access constraints, budget limitations, or political conflict. Quantifying the global, regional, and temporal representativeness of these networks by quantifying the coverage of network infrastructure highlights the capabilities and limitations of the data collected, facilitates upscaling and downscaling for modeling purposes, and improves the planning efforts for future infrastructure investment under current conditions and future modeled scenarios. The work presented here utilizes multivariate spatiotemporal clustering analysis and representativeness analysis for quantitative landscape characterization and assessment of the Fluxnet, RAINFOR, and ForestGEO networks. Results include ecoregions that highlight patterns of bioclimatic, topographic, and edaphic variables and quantitative representativeness maps of individual and combined networks.

  17. Landscape Characterization and Representativeness Analysis for Understanding Sampling Network Coverage

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Maddalena, Damian; Hoffman, Forrest; Kumar, Jitendra; Hargrove, William

    Sampling networks rarely conform to spatial and temporal ideals, often comprised of network sampling points which are unevenly distributed and located in less than ideal locations due to access constraints, budget limitations, or political conflict. Quantifying the global, regional, and temporal representativeness of these networks by quantifying the coverage of network infrastructure highlights the capabilities and limitations of the data collected, facilitates upscaling and downscaling for modeling purposes, and improves the planning efforts for future infrastructure investment under current conditions and future modeled scenarios. The work presented here utilizes multivariate spatiotemporal clustering analysis and representativeness analysis for quantitative landscape characterization and assessment of the Fluxnet, RAINFOR, and ForestGEO networks. Results include ecoregions that highlight patterns of bioclimatic, topographic, and edaphic variables and quantitative representativeness maps of individual and combined networks.

  18. GLOBULAR CLUSTER SYSTEMS IN BRIGHTEST CLUSTER GALAXIES: A NEAR-UNIVERSAL LUMINOSITY FUNCTION?

    SciTech Connect (OSTI)

    Harris, William E.; O'Halloran, Heather; Cockcroft, Robert E-mail: ohallohm@mcmaster.ca; and others

    2014-12-20

    We present the first results from our Hubble Space Telescope brightest cluster galaxy (BCG) survey of seven central supergiant cluster galaxies and their globular cluster (GC) systems. We measure a total of 48,000 GCs in all seven galaxies, representing the largest single GC database. We find that a log-normal shape accurately matches the observed the luminosity function (LF) of the GCs down to the globular cluster luminosity function turnover point, which is near our photometric limit. In addition, the LF has a virtually identical shape in all seven galaxies. Our data underscore the similarity in the formation mechanism of massive star clusters in diverse galactic environments. At the highest luminosities (L ? 10{sup 7} L {sub ?}), we find small numbers of ''superluminous'' objects in five of the galaxies; their luminosity and color ranges are at least partly consistent with those of ultra-compact dwarfs. Last, we find preliminary evidence that in the outer halo (R ? 20kpc), the LF turnover point shows a weak dependence on projected distance, scaling as L {sub 0} ? R {sup 0.2}, while the LF dispersion remains nearly constant.

  19. BINARY QUASARS IN THE SLOAN DIGITAL SKY SURVEY: EVIDENCE FOR EXCESS CLUSTERING ON SMALL SCALES

    SciTech Connect (OSTI)

    Hennawi, J F; Strauss, M A; Oguri, M; Inada, N; Richards, G T; Pindor, B; Schneider, D P; Becker, R H; Gregg, M D; Hall, P B; Johnston, D E; Fan, X; Burles, S; Schlegel, D J; Gunn, J E; Lupton, R; Bahcall, N A; Brunner, R J; Brinkman, J

    2005-11-10

    We present a sample of 218 new quasar pairs with proper transverse separations R{sub prop} < 1 h{sup -1} Mpc over the redshift range 0.5 < z < 3.0, discovered from an extensive follow up campaign to find companions around the Sloan Digital Sky Survey and 2dF Quasar Redshift Survey quasars. This sample includes 26 new binary quasars with separations R{sub prop} < 50 h{sup -1} kpc ({theta} < 10''), more than doubling the number of such systems known. We define a statistical sample of binaries selected with homogeneous criteria and compute its selection function, taking into account sources of incompleteness. The first measurement of the quasar correlation function on scales 10 h{sup -1} kpc < R{sub prop} < 400 h{sup -1} kpc is presented. For R{sub prop} {approx}< 40 h{sup -1} kpc, we detect an order of magnitude excess clustering over the expectation from the large scale (R{sub prop} {approx}> 3 h{sup -1} Mpc) quasar correlation function, extrapolated down as a power law to the separations probed by our binaries. The excess grows to {approx}30 at R{sub prop} {approx} 10 h{sup -1} kpc, and provides compelling evidence that the quasar autocorrelation function gets progressively steeper on sub-Mpc scales. This small scale excess can likely be attributed to dissipative interaction events which trigger quasar activity in rich environments. Recent small scale measurements of galaxy clustering and quasar-galaxy clustering are reviewed and discussed in relation to our measurement of small scale quasar clustering.

  20. Defining And Characterizing Sample Representativeness For DWPF Melter Feed Samples

    SciTech Connect (OSTI)

    Shine, E. P.; Poirier, M. R.

    2013-10-29

    Representative sampling is important throughout the Defense Waste Processing Facility (DWPF) process, and the demonstrated success of the DWPF process to achieve glass product quality over the past two decades is a direct result of the quality of information obtained from the process. The objective of this report was to present sampling methods that the Savannah River Site (SRS) used to qualify waste being dispositioned at the DWPF. The goal was to emphasize the methodology, not a list of outcomes from those studies. This methodology includes proven methods for taking representative samples, the use of controlled analytical methods, and data interpretation and reporting that considers the uncertainty of all error sources. Numerous sampling studies were conducted during the development of the DWPF process and still continue to be performed in order to evaluate options for process improvement. Study designs were based on use of statistical tools applicable to the determination of uncertainties associated with the data needs. Successful designs are apt to be repeated, so this report chose only to include prototypic case studies that typify the characteristics of frequently used designs. Case studies have been presented for studying in-tank homogeneity, evaluating the suitability of sampler systems, determining factors that affect mixing and sampling, comparing the final waste glass product chemical composition and durability to that of the glass pour stream sample and other samples from process vessels, and assessing the uniformity of the chemical composition in the waste glass product. Many of these studies efficiently addressed more than one of these areas of concern associated with demonstrating sample representativeness and provide examples of statistical tools in use for DWPF. The time when many of these designs were implemented was in an age when the sampling ideas of Pierre Gy were not as widespread as they are today. Nonetheless, the engineers and

  1. Superfluid response of two-dimensional parahydrogen clusters in confinement

    SciTech Connect (OSTI)

    Idowu, Saheed; Boninsegni, Massimo

    2015-04-07

    We study by computer simulations the effect of confinement on the superfluid properties of small two-dimensional (2D) parahydrogen clusters. For clusters of fewer than twenty molecules, the superfluid response in the low temperature limit is found to remain comparable in magnitude to that of free clusters, within a rather wide range of depth and size of the confining well. The resilience of the superfluid response is attributable to the “supersolid” character of these clusters. We investigate the possibility of establishing a bulk 2D superfluid “cluster crystal” phase of p-H{sub 2}, in which a global superfluid response would arise from tunnelling of molecules across adjacent unit cells. The computed energetics suggests that for clusters of about ten molecules, such a phase may be thermodynamically stable against the formation of the equilibrium insulating crystal, for values of the cluster crystal lattice constant possibly allowing tunnelling across adjacent unit cells.

  2. Constraints on the richness-mass relation and the optical-SZE positional offset distribution for SZE-selected clusters

    SciTech Connect (OSTI)

    Saro, A.

    2015-10-12

    In this study, we cross-match galaxy cluster candidates selected via their Sunyaev–Zel'dovich effect (SZE) signatures in 129.1 deg2 of the South Pole Telescope 2500d SPT-SZ survey with optically identified clusters selected from the Dark Energy Survey science verification data. We identify 25 clusters between 0.1 ≲ z ≲ 0.8 in the union of the SPT-SZ and redMaPPer (RM) samples. RM is an optical cluster finding algorithm that also returns a richness estimate for each cluster. We model the richness λ-mass relation with the following function 500> ∝ Bλln M500 + Cλln E(z) and use SPT-SZ cluster masses and RM richnesses λ to constrain the parameters. We find Bλ=1.14+0.21–0.18 and Cλ=0.73+0.77–0.75. The associated scatter in mass at fixed richness is σlnM|λ = 0.18+0.08–0.05 at a characteristic richness λ = 70. We demonstrate that our model provides an adequate description of the matched sample, showing that the fraction of SPT-SZ-selected clusters with RM counterparts is consistent with expectations and that the fraction of RM-selected clusters with SPT-SZ counterparts is in mild tension with expectation. We model the optical-SZE cluster positional offset distribution with the sum of two Gaussians, showing that it is consistent with a dominant, centrally peaked population and a subdominant population characterized by larger offsets. We also cross-match the RM catalogue with SPT-SZ candidates below the official catalogue threshold significance ξ = 4.5, using the RM catalogue to provide optical confirmation and redshifts for 15 additional clusters with ξ ε [4, 4.5].

  3. Extended main sequence turnoffs in intermediate-age star clusters: a correlation between turnoff width and early escape velocity

    SciTech Connect (OSTI)

    Goudfrooij, Paul; Kozhurina-Platais, Vera; Kalirai, Jason S.; Correnti, Matteo E-mail: verap@stsci.edu E-mail: correnti@stsci.edu; and others

    2014-12-10

    We present a color-magnitude diagram analysis of deep Hubble Space Telescope imaging of a mass-limited sample of 18 intermediate-age (1-2 Gyr old) star clusters in the Magellanic Clouds, including eight clusters for which new data were obtained. We find that all star clusters in our sample feature extended main-sequence turnoff (eMSTO) regions that are wider than can be accounted for by a simple stellar population (including unresolved binary stars). FWHM widths of the MSTOs indicate age spreads of 200-550 Myr. We evaluate the dynamical evolution of clusters with and without initial mass segregation. Our main results are (1) the fraction of red clump (RC) stars in secondary RCs in eMSTO clusters scales with the fraction of MSTO stars having pseudo-ages of ?1.35 Gyr; (2) the width of the pseudo-age distributions of eMSTO clusters is correlated with their central escape velocity v {sub esc}, both currently and at an age of 10 Myr. We find that these two results are unlikely to be reproduced by the effects of interactive binary stars or a range of stellar rotation velocities. We therefore argue that the eMSTO phenomenon is mainly caused by extended star formation within the clusters; and (3) we find that v {sub esc} ? 15 km s{sup 1} out to ages of at least 100 Myr for all clusters featuring eMSTOs, and v {sub esc} ? 12 km s{sup 1} at all ages for two lower-mass clusters in the same age range that do not show eMSTOs. We argue that eMSTOs only occur for clusters whose early escape velocities are higher than the wind velocities of stars that provide material from which second-generation stars can form. The threshold of 12-15 km s{sup 1} is consistent with wind velocities of intermediate-mass asymptotic giant branch stars and massive binary stars in the literature.

  4. Sample Business Plan Framework 5

    Broader source: Energy.gov [DOE]

    U.S. Department of Energy Better Buildings Neighborhood Program: Sample Business Plan Framework 5: A program that establishes itself as a government entity, then operates using a fee-based structure.

  5. Sample Business Plan Framework 2

    Broader source: Energy.gov [DOE]

    U.S. Department of Energy Better Buildings Neighborhood Program: Sample Business Plan Framework 1: A program seeking to continue operations in the post-grant period as a not-for-profit (NGO) entity.

  6. Sample Business Plan Framework 4

    Broader source: Energy.gov [DOE]

    U.S. Department of Energy Better Buildings Neighborhood Program: Sample Business Plan Framework 4: A program seeking to continue in the post-grant period as a marketing contractor to a utility.

  7. Sample Business Plan Framework 3

    Broader source: Energy.gov [DOE]

    U.S. Department of Energy Better Buildings Neighborhood Program: Sample Business Plan Framework 3: A government entity running a Commercial PACE program in the post-grant period.

  8. UNDERSTANDING THE AIR SAMPLING DATA

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

    For more comparisons, see the millirem comparisons poster. Dose estimates have been calculated based on the low-volume air sampler results. Low-volume air samplers collect samples ...

  9. Air Sampling System Evaluation Template

    Energy Science and Technology Software Center (OSTI)

    2000-05-09

    The ASSET1.0 software provides a template with which a user can evaluate an Air Sampling System against the latest version of ANSI N13.1 "Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stacks and Ducts of Nuclear Facilities". The software uses the ANSI N13.1 PIC levels to establish basic design criteria for the existing or proposed sampling system. The software looks at such criteria as PIC level, type of radionuclide emissions, physical state ofmore » the radionuclide, nozzle entrance effects, particulate transmission effects, system and component accuracy and precision evaluations, and basic system operations to provide a detailed look at the subsystems of a monitoring and sampling system/program. A GAP evaluation can then be completed which leads to identification of design and operational flaws in the proposed systems. Corrective measures can then be limited to the GAPs.« less

  10. Equipment Inventory | Sample Preparation Laboratories

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

    21KBr Centrifuge Centrifuge SSRL BioChemMat Prep Lab 2 131 209 Saint Gobain K-104 Sanyo MIR-154 Cooled Incubator Temperature Control LCLS Sample Prep Lab 999 109 Sanyo MPR-215F...

  11. Sample Business Plan Framework 1

    Broader source: Energy.gov [DOE]

    U.S. Department of Energy Better Buildings Neighborhood Program: Sample Business Plan Framework 1: A program seeking to continue operations in the post-grant period as a not-for-profit (NGO) entity.

  12. Depth-discrete sampling port

    DOE Patents [OSTI]

    Pemberton, Bradley E.; May, Christopher P.; Rossabi, Joseph; Riha, Brian D.; Nichols, Ralph L.

    1999-01-01

    A sampling port is provided which has threaded ends for incorporating the port into a length of subsurface pipe. The port defines an internal receptacle which is in communication with subsurface fluids through a series of fine filtering slits. The receptacle is in further communication through a bore with a fitting carrying a length of tubing there which samples are transported to the surface. Each port further defines an additional bore through which tubing, cables, or similar components of adjacent ports may pass.

  13. Depth-discrete sampling port

    DOE Patents [OSTI]

    Pemberton, Bradley E.; May, Christopher P.; Rossabi, Joseph; Riha, Brian D.; Nichols, Ralph L.

    1998-07-07

    A sampling port is provided which has threaded ends for incorporating the port into a length of subsurface pipe. The port defines an internal receptacle which is in communication with subsurface fluids through a series of fine filtering slits. The receptacle is in further communication through a bore with a fitting carrying a length of tubing there which samples are transported to the surface. Each port further defines an additional bore through which tubing, cables, or similar components of adjacent ports may pass.

  14. Locally Renormalized Coupled-Cluster Equations for Singly and Doubly Excited Clusters

    SciTech Connect (OSTI)

    Kowalski, Karol

    2006-07-10

    The Numerator-Denominator Connected (NDC) Expansion for the Coupled-Cluster (CC) method [K. Kowalski, P. Piecuch, J. Chem. Phys. 122 (2005) 074107], is used to construct a new set of stationary conditions for approximate coupled-cluster approaches. Several CC approximations based on models involving singles and doubles (CCSD) as well as singles, doubles, and triples (CCSDT) are developed and discussed in the context of ground-state applications. The resulting locally-renormalized CCSD (LR-CCSD) and CCSDT (LR-CCSDT) equations are shown to regularize the expressions for the cluster amplitudes in the challenging situations that occur when the orbital energy differences approach zero. Affordable schemes for handling the local denominators (all-holes-Jn coupling), that naturally appear in locally renormalized formalisms, are also discussed.

  15. The redshift evolution of the mean temperature, pressure, and entropy profiles in 80 SPT-selected galaxy clusters

    SciTech Connect (OSTI)

    McDonald, M.; Bautz, M.; Benson, B. A.; Vikhlinin, A.; Bayliss, M.; Forman, W. R.; Aird, K. A.; Allen, S. W.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; Bocquet, S.; Brodwin, M.; Cho, H. M.; Clocchiatti, A.; De Haan, T.; Dobbs, M. A.; Foley, R. J.; and others

    2014-10-10

    We present the results of an X-ray analysis of 80 galaxy clusters selected in the 2500 deg{sup 2} South Pole Telescope survey and observed with the Chandra X-ray Observatory. We divide the full sample into subsamples of ?20 clusters based on redshift and central density, performing a joint X-ray spectral fit to all clusters in a subsample simultaneously, assuming self-similarity of the temperature profile. This approach allows us to constrain the shape of the temperature profile over 0 < r < 1.5R {sub 500}, which would be impossible on a per-cluster basis, since the observations of individual clusters have, on average, 2000 X-ray counts. The results presented here represent the first constraints on the evolution of the average temperature profile from z = 0 to z = 1.2. We find that high-z (0.6 < z < 1.2) clusters are slightly (?30%) cooler both in the inner (r < 0.1R {sub 500}) and outer (r > R {sub 500}) regions than their low-z (0.3 < z < 0.6) counterparts. Combining the average temperature profile with measured gas density profiles from our earlier work, we infer the average pressure and entropy profiles for each subsample. Confirming earlier results from this data set, we find an absence of strong cool cores at high z, manifested in this analysis as a significantly lower observed pressure in the central 0.1R {sub 500} of the high-z cool-core subset of clusters compared to the low-z cool-core subset. Overall, our observed pressure profiles agree well with earlier lower-redshift measurements, suggesting minimal redshift evolution in the pressure profile outside of the core. We find no measurable redshift evolution in the entropy profile at r ? 0.7R {sub 500}this may reflect a long-standing balance between cooling and feedback over long timescales and large physical scales. We observe a slight flattening of the entropy profile at r ? R {sub 500} in our high-z subsample. This flattening is consistent with a temperature bias due to the enhanced (?3) rate at which

  16. Aerosol cluster impact and break-up : II. Atomic and Cluster Scale Models.

    SciTech Connect (OSTI)

    Lechman, Jeremy B.; Takato, Yoichi

    2010-09-01

    Understanding the interaction of aerosol particle clusters/flocs with surfaces is an area of interest for a number of processes in chemical, pharmaceutical, and powder manufacturing as well as in steam-tube rupture in nuclear power plants. Developing predictive capabilities for these applications involves coupled phenomena on multiple length and timescales from the process macroscopic scale ({approx}1m) to the multi-cluster interaction scale (1mm-0.1m) to the single cluster scale ({approx}1000 - 10000 particles) to the particle scale (10nm-10{micro}m) interactions, and on down to the sub-particle, atomic scale interactions. The focus of this report is on the single cluster scale; although work directed toward developing better models of particle-particle interactions by considering sub-particle scale interactions and phenomena is also described. In particular, results of mesoscale (i.e., particle to single cluster scale) discrete element method (DEM) simulations for aerosol cluster impact with rigid walls are presented. The particle-particle interaction model is based on JKR adhesion theory and is implemented as an enhancement to the granular package in the LAMMPS code. The theory behind the model is outlined and preliminary results are shown. Additionally, as mentioned, results from atomistic classical molecular dynamics simulations are also described as a means of developing higher fidelity models of particle-particle interactions. Ultimately, the results from these and other studies at various scales must be collated to provide systems level models with accurate 'sub-grid' information for design, analysis and control of the underlying systems processes.

  17. Modeling the formation of globular cluster systems in the Virgo cluster

    SciTech Connect (OSTI)

    Li, Hui; Gnedin, Oleg Y. E-mail: ognedin@umich.edu

    2014-11-20

    The mass distribution and chemical composition of globular cluster (GC) systems preserve fossil record of the early stages of galaxy formation. The observed distribution of GC colors within massive early-type galaxies in the ACS Virgo Cluster Survey (ACSVCS) reveals a multi-modal shape, which likely corresponds to a multi-modal metallicity distribution. We present a simple model for the formation and disruption of GCs that aims to match the ACSVCS data. This model tests the hypothesis that GCs are formed during major mergers of gas-rich galaxies and inherit the metallicity of their hosts. To trace merger events, we use halo merger trees extracted from a large cosmological N-body simulation. We select 20 halos in the mass range of 2 10{sup 12} to 7 10{sup 13} M {sub ?} and match them to 19 Virgo galaxies with K-band luminosity between 3 10{sup 10} and 3 10{sup 11} L {sub ?}. To set the [Fe/H] abundances, we use an empirical galaxy mass-metallicity relation. We find that a minimal merger ratio of 1:3 best matches the observed cluster metallicity distribution. A characteristic bimodal shape appears because metal-rich GCs are produced by late mergers between massive halos, while metal-poor GCs are produced by collective merger activities of less massive hosts at early times. The model outcome is robust to alternative prescriptions for cluster formation rate throughout cosmic time, but a gradual evolution of the mass-metallicity relation with redshift appears to be necessary to match the observed cluster metallicities. We also affirm the age-metallicity relation, predicted by an earlier model, in which metal-rich clusters are systematically several billion younger than their metal-poor counterparts.

  18. Ball assisted device for analytical surface sampling

    SciTech Connect (OSTI)

    ElNaggar, Mariam S; Van Berkel, Gary J; Covey, Thomas R

    2015-11-03

    A system for sampling a surface includes a sampling probe having a housing and a socket, and a rolling sampling sphere within the socket. The housing has a sampling fluid supply conduit and a sampling fluid exhaust conduit. The sampling fluid supply conduit supplies sampling fluid to the sampling sphere. The sampling fluid exhaust conduit has an inlet opening for receiving sampling fluid carried from the surface by the sampling sphere. A surface sampling probe and a method for sampling a surface are also disclosed.

  19. Stellar age spreads in clusters as imprints of cluster-parent clump densities

    SciTech Connect (OSTI)

    Parmentier, G.; Grebel, E. K.; Pfalzner, S.

    2014-08-20

    It has recently been suggested that high-density star clusters have stellar age distributions much narrower than that of the Orion Nebula Cluster, indicating a possible trend of narrower age distributions for denser clusters. We show this effect to likely arise from star formation being faster in gas with a higher density. We model the star formation history of molecular clumps in equilibrium by associating a star formation efficiency per free-fall time, ?{sub ff}, to their volume density profile. We focus on the case of isothermal spheres and we obtain the evolution with time of their star formation rate. Our model predicts a steady decline of the star formation rate, which we quantify with its half-life time, namely, the time needed for the star formation rate to drop to half its initial value. Given the uncertainties affecting the star formation efficiency per free-fall time, we consider two distinct values: ?{sub ff} = 0.1 and ?{sub ff} = 0.01. When ?{sub ff} = 0.1, the half-life time is of the order of the clump free-fall time, ?{sub ff}. As a result, the age distributions of stars formed in high-density clumps have smaller full-widths at half-maximum than those of stars formed in low-density clumps. When the star formation efficiency per free-fall time is 0.01, the half-life time is 10 times longer, i.e., 10 clump free-fall times. We explore what happens if the duration of star formation is shorter than 10?{sub ff}, that is, if the half-life time of the star formation rate cannot be defined. There, we build on the invariance of the shape of the young cluster mass function to show that an anti-correlation between the clump density and the duration of star formation is expected. We therefore conclude that, regardless of whether the duration of star formation is longer than the star formation rate half-life time, denser molecular clumps yield narrower star age distributions in clusters. Published densities and stellar age spreads of young clusters and star

  20. THE GLOBULAR CLUSTER SYSTEM OF THE MILKY WAY: ACCRETION IN A COSMOLOGICAL CONTEXT

    SciTech Connect (OSTI)

    Keller, Stefan C.; Mackey, Dougal; Da Costa, Gary S.

    2012-01-01

    We examine the significance of a planar arrangement in the spatial distribution of the Milky Way (MW) globular clusters (GCs). We find that, when separated on the basis of horizontal branch morphology and metallicity, the outermost canonical young halo (YH) GC sample (at galactocentric radii in excess of 10 kpc) exhibits an anisotropic distribution that may be equated to a plane (24 {+-} 4) kpc thick (rms) and inclined at 8 Degree-Sign {+-} 5 Degree-Sign to the polar axis of the MW disk. To quantify the significance of this plane we determine the fraction of times that an isotropic distribution replicates the observed distribution in Monte Carlo trials. The plane is found to remain significant at the >95% level outside a galactocentric radius of 10 kpc, inside this radius the spatial distribution is apparently isotropic. In contrast, the spatial distribution of the old halo sample outside 10 kpc is well matched by an isotropic distribution. The plane described by the outer YH GCs is indistinguishable in orientation from that presented by the satellite galaxies of the MW. Simulations have shown that the planar arrangement of satellites can arise as filaments of the surrounding large-scale structure feed into the MW's potential. We therefore propose that our results are direct observational evidence for the accreted origin of the outer YH GC population. This conclusion confirms numerous lines of evidence that have similarly indicated an accreted origin for this set of clusters from the inferred cluster properties.

  1. MOCK OBSERVATIONS OF BLUE STRAGGLERS IN GLOBULAR CLUSTER MODELS

    SciTech Connect (OSTI)

    Sills, Alison; Glebbeek, Evert; Chatterjee, Sourav; Rasio, Frederic A. E-mail: e.glebbeek@astro.ru.nl E-mail: rasio@northwestern.edu

    2013-11-10

    We created artificial color-magnitude diagrams of Monte Carlo dynamical models of globular clusters and then used observational methods to determine the number of blue stragglers in those clusters. We compared these blue stragglers to various cluster properties, mimicking work that has been done for blue stragglers in Milky Way globular clusters to determine the dominant formation mechanism(s) of this unusual stellar population. We find that a mass-based prescription for selecting blue stragglers will select approximately twice as many blue stragglers than a selection criterion that was developed for observations of real clusters. However, the two numbers of blue stragglers are well-correlated, so either selection criterion can be used to characterize the blue straggler population of a cluster. We confirm previous results that the simplified prescription for the evolution of a collision or merger product in the BSE code overestimates their lifetimes. We show that our model blue stragglers follow similar trends with cluster properties (core mass, binary fraction, total mass, collision rate) as the true Milky Way blue stragglers as long as we restrict ourselves to model clusters with an initial binary fraction higher than 5%. We also show that, in contrast to earlier work, the number of blue stragglers in the cluster core does have a weak dependence on the collisional parameter ? in both our models and in Milky Way globular clusters.

  2. ULTRA-COMPACT DWARFS IN THE COMA CLUSTER

    SciTech Connect (OSTI)

    Chiboucas, Kristin; Tully, R. Brent; Marzke, R. O.; Phillipps, S.; Price, J.; Peng, Eric W.; Trentham, Neil; Carter, David; Hammer, Derek E-mail: tully@ifa.hawaii.edu E-mail: S.Phillipps@bristol.ac.uk E-mail: peng@pku.edu.cn E-mail: dxc@astro.livjm.ac.uk

    2011-08-20

    We have undertaken a spectroscopic search for ultra-compact dwarf galaxies (UCDs) in the dense core of the dynamically evolved, massive Coma cluster as part of the Hubble Space Telescope/Advanced Camera for Surveys (HST/ACS) Coma Cluster Treasury Survey. UCD candidates were initially chosen based on color, magnitude, degree of resolution within the ACS images, and the known properties of Fornax and Virgo UCDs. Follow-up spectroscopy with Keck/Low-Resolution Imaging Spectrometer confirmed 27 candidates as members of the Coma cluster, a success rate >60% for targeted objects brighter than M{sub R} = -12. Another 14 candidates may also prove to be Coma members, but low signal-to-noise spectra prevent definitive conclusions. An investigation of the properties and distribution of the Coma UCDs finds these objects to be very similar to UCDs discovered in other environments. The Coma UCDs tend to be clustered around giant galaxies in the cluster core and have colors/metallicity that correlate with the host galaxy. With properties and a distribution similar to that of the Coma cluster globular cluster population, we find strong support for a star cluster origin for the majority of the Coma UCDs. However, a few UCDs appear to have stellar population or structural properties which differentiate them from the old star cluster populations found in the Coma cluster, perhaps indicating that UCDs may form through multiple formation channels.

  3. LENSING NOISE IN MILLIMETER-WAVE GALAXY CLUSTER SURVEYS

    SciTech Connect (OSTI)

    Hezaveh, Yashar; Vanderlinde, Keith; Holder, Gilbert; De Haan, Tijmen

    2013-08-01

    We study the effects of gravitational lensing by galaxy clusters of the background of dusty star-forming galaxies (DSFGs) and the cosmic microwave background (CMB), and examine the implications for Sunyaev-Zel'dovich-based (SZ) galaxy cluster surveys. At the locations of galaxy clusters, gravitational lensing modifies the probability distribution of the background flux of the DSFGs as well as the CMB. We find that, in the case of a single-frequency 150 GHz survey, lensing of DSFGs leads both to a slight increase ({approx}10%) in detected cluster number counts (due to a {approx}50% increase in the variance of the DSFG background, and hence an increased Eddington bias) and a rare (occurring in {approx}2% of clusters) 'filling-in' of SZ cluster signals by bright strongly lensed background sources. Lensing of the CMB leads to a {approx}55% reduction in CMB power at the location of massive galaxy clusters in a spatially matched single-frequency filter, leading to a net decrease in detected cluster number counts. We find that the increase in DSFG power and decrease in CMB power due to lensing at cluster locations largely cancel, such that the net effect on cluster number counts for current SZ surveys is subdominant to Poisson errors.

  4. Cluster computing software for GATE simulations

    SciTech Connect (OSTI)

    Beenhouwer, Jan de; Staelens, Steven; Kruecker, Dirk; Ferrer, Ludovic; D'Asseler, Yves; Lemahieu, Ignace; Rannou, Fernando R.

    2007-06-15

    Geometry and tracking (GEANT4) is a Monte Carlo package designed for high energy physics experiments. It is used as the basis layer for Monte Carlo simulations of nuclear medicine acquisition systems in GEANT4 Application for Tomographic Emission (GATE). GATE allows the user to realistically model experiments using accurate physics models and time synchronization for detector movement through a script language contained in a macro file. The downside of this high accuracy is long computation time. This paper describes a platform independent computing approach for running GATE simulations on a cluster of computers in order to reduce the overall simulation time. Our software automatically creates fully resolved, nonparametrized macros accompanied with an on-the-fly generated cluster specific submit file used to launch the simulations. The scalability of GATE simulations on a cluster is investigated for two imaging modalities, positron emission tomography (PET) and single photon emission computed tomography (SPECT). Due to a higher sensitivity, PET simulations are characterized by relatively high data output rates that create rather large output files. SPECT simulations, on the other hand, have lower data output rates but require a long collimator setup time. Both of these characteristics hamper scalability as a function of the number of CPUs. The scalability of PET simulations is improved here by the development of a fast output merger. The scalability of SPECT simulations is improved by greatly reducing the collimator setup time. Accordingly, these two new developments result in higher scalability for both PET and SPECT simulations and reduce the computation time to more practical values.

  5. Tank characterization technical sampling basis

    SciTech Connect (OSTI)

    Brown, T.M.

    1998-04-28

    Tank Characterization Technical Sampling Basis (this document) is the first step of an in place working process to plan characterization activities in an optimal manner. This document will be used to develop the revision of the Waste Information Requirements Document (WIRD) (Winkelman et al. 1997) and ultimately, to create sampling schedules. The revised WIRD will define all Characterization Project activities over the course of subsequent fiscal years 1999 through 2002. This document establishes priorities for sampling and characterization activities conducted under the Tank Waste Remediation System (TWRS) Tank Waste Characterization Project. The Tank Waste Characterization Project is designed to provide all TWRS programs with information describing the physical, chemical, and radiological properties of the contents of waste storage tanks at the Hanford Site. These tanks contain radioactive waste generated from the production of nuclear weapons materials at the Hanford Site. The waste composition varies from tank to tank because of the large number of chemical processes that were used when producing nuclear weapons materials over the years and because the wastes were mixed during efforts to better use tank storage space. The Tank Waste Characterization Project mission is to provide information and waste sample material necessary for TWRS to define and maintain safe interim storage and to process waste fractions into stable forms for ultimate disposal. This document integrates the information needed to address safety issues, regulatory requirements, and retrieval, treatment, and immobilization requirements. Characterization sampling to support tank farm operational needs is also discussed.

  6. THE CLUSTERING AND HALO MASSES OF STAR-FORMING GALAXIES AT z < 1

    SciTech Connect (OSTI)

    Dolley, Tim; Brown, Michael J. I.; Pimbblet, Kevin A.; Palamara, David P.; Beare, Richard; Weiner, Benjamin J.; Jannuzi, Buell T.; Brodwin, Mark; Kochanek, C. S.; Dey, Arjun; Atlee, David W.

    2014-12-20

    We present clustering measurements and halo masses of star-forming galaxies at 0.2 < z < 1.0. After excluding active galactic nuclei (AGNs), we construct a sample of 22,553 24 μm sources selected from 8.42 deg{sup 2} of the Spitzer MIPS AGN and Galaxy Evolution Survey of Boötes. Mid-infrared imaging allows us to observe galaxies with the highest star formation rates (SFRs), less biased by dust obscuration afflicting the optical bands. We find that the galaxies with the highest SFRs have optical colors that are redder than typical blue cloud galaxies, with many residing within the green valley. At z > 0.4 our sample is dominated by luminous infrared galaxies (LIRGs, L {sub TIR} > 10{sup 11} L {sub ☉}) and is composed entirely of LIRGs and ultraluminous infrared galaxies (ULIRGs, L {sub TIR} > 10{sup 12} L {sub ☉}) at z > 0.6. We observe weak clustering of r {sub 0} ≈ 3-6 h {sup –1} Mpc for almost all of our star-forming samples. We find that the clustering and halo mass depend on L {sub TIR} at all redshifts, where galaxies with higher L {sub TIR} (hence higher SFRs) have stronger clustering. Galaxies with the highest SFRs at each redshift typically reside within dark matter halos of M {sub halo} ≈ 10{sup 12.9} h {sup –1} M {sub ☉}. This is consistent with a transitional halo mass, above which star formation is largely truncated, although we cannot exclude that ULIRGs reside within higher mass halos. By modeling the clustering evolution of halos, we connect our star-forming galaxy samples to their local descendants. Most star-forming galaxies at z < 1.0 are the progenitors of L ≲ 2.5 L {sub *} blue galaxies in the local universe, but star-forming galaxies with the highest SFRs (L {sub TIR} ≳ 10{sup 11.7} L {sub ☉}) at 0.6 < z < 1.0 are the progenitors of early-type galaxies in denser group environments.

  7. Sample Results from Routine Salt Batch 7 Samples

    SciTech Connect (OSTI)

    Peters, T.

    2015-05-13

    Strip Effluent Hold Tank (SEHT) and Decontaminated Salt Solution Hold Tank (DSSHT) samples from several of the microbatches of Integrated Salt Disposition Project (ISDP) Salt Batch (Macrobatch) 7B have been analyzed for 238Pu, 90Sr, 137Cs, Inductively Coupled Plasma Emission Spectroscopy (ICPES), and Ion Chromatography Anions (IC-A). The results from the current microbatch samples are similar to those from earlier samples from this and previous macrobatches. The Actinide Removal Process (ARP) and the Modular Caustic-Side Solvent Extraction Unit (MCU) continue to show more than adequate Pu and Sr removal, and there is a distinct positive trend in Cs removal, due to the use of the Next Generation Solvent (NGS). The Savannah River National Laboratory (SRNL) notes that historically, most measured Concentration Factor (CF) values during salt processing have been in the 12-14 range. However, recent processing gives CF values closer to 11. This observation does not indicate that the solvent performance is suffering, as the Decontamination Factor (DF) has still maintained consistently high values. Nevertheless, SRNL will continue to monitor for indications of process upsets. The bulk chemistry of the DSSHT and SEHT samples do not show any signs of unusual behavior.

  8. Visual Matrix Clustering of Social Networks

    SciTech Connect (OSTI)

    Wong, Pak C.; Mackey, Patrick S.; Foote, Harlan P.; May, Richard A.

    2013-07-01

    The prevailing choices to graphically represent a social network in todays literature are a node-link graph layout and an adjacency matrix. Both visualization techniques have unique strengths and weaknesses when applied to different domain applications. In this article, we focus our discussion on adjacency matrix and how to turn the matrix-based visualization technique from merely showing pairwise associations among network actors (or graph nodes) to depicting clusters of a social network. We also use node-link layouts to supplement the discussion.

  9. Model-Based Sampling and Inference

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

    Model-Based Sampling, Inference and Imputation James R. Knaub, Jr., Energy Information Administration, EI-53.1 James.Knaub@eia.doe.gov Key Words: Survey statistics, Randomization, Conditionality, Random sampling, Cutoff sampling Abstract: Picking a sample through some randomization mechanism, such as random sampling within groups (stratified random sampling), or, say, sampling every fifth item (systematic random sampling), may be familiar to a lot of people. These are design-based samples.

  10. Viscous-sludge sample collector

    DOE Patents [OSTI]

    Not Available

    1979-01-01

    A vertical core sample collection system for viscous sludge is disclosed. A sample tube's upper end has a flange and is attached to a piston. The tube and piston are located in the upper end of a bore in a housing. The bore's lower end leads outside the housing and has an inwardly extending rim. Compressed gas, from a storage cylinder, is quickly introduced into the bore's upper end to rapidly accelerate the piston and tube down the bore. The lower end of the tube has a high sludge entering velocity to obtain a full-length sludge sample without disturbing strata detail. The tube's downward motion is stopped when its upper end flange impacts against the bore's lower end inwardly extending rim.

  11. Gamma rays from clusters and groups of galaxies: Cosmic rays versus dark matter

    SciTech Connect (OSTI)

    Jeltema, Tesla E.; Profumo, Stefano

    2009-07-15

    Clusters of galaxies have not yet been detected at gamma-ray frequencies; however, the recently launched Fermi Gamma-ray Space Telescope, formerly known as GLAST, could provide the first detections in the near future. Clusters are expected to emit gamma rays as a result of (1) a population of high-energy cosmic rays fueled by accretion, merger shocks, active galactic nuclei, and supernovae, and (2) particle dark-matter annihilation. In this paper, we ask the question of whether the Fermi telescope will be able to discriminate between the two emission processes. We present data-driven predictions for the gamma-ray emission from cosmic rays and dark matter for a large x-ray-flux-limited sample of galaxy clusters and groups. We point out that the gamma-ray signals from cosmic rays and dark matter can be comparable. In particular, we find that poor clusters and groups are the systems predicted to have the highest dark-matter to cosmic-ray emission ratio at gamma-ray energies. Based on detailed Fermi simulations, we study observational handles that might enable us to distinguish the two emission mechanisms, including the gamma-ray spectra, the spatial distribution of the signal, and the associated multiwavelength emissions. We also propose optimal hardness ratios, which will help us to understand the nature of the gamma-ray emission. Our study indicates that gamma rays from dark-matter annihilation with a high particle mass can be distinguished from a cosmic-ray spectrum even for fairly faint sources. Discriminating a cosmic-ray spectrum from a light dark-matter particle will be, instead, much more difficult, and will require long observations and/or a bright source. While the gamma-ray emission from our simulated clusters is extended, determining the spatial distribution with Fermi will be a challenging task requiring an optimal control of the backgrounds.

  12. Revisiting benzene cluster cations for the chemical ionization of dimethyl sulfide and select volatile organic compounds

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

    Kim, Michelle J.; Zoerb, Matthew C.; Campbell, Nicole R.; Zimmermann, Kathryn J.; Blomquist, Byron W.; Huebert, Barry J.; Bertram, Timothy H.

    2016-01-01

    Benzene cluster cations were revisited as a sensitive and selective reagent ion for the chemical ionization of dimethyl sulfide (DMS) and a select group of volatile organic compounds (VOCs). Laboratory characterization was performed using both a new set of compounds (i.e., DMS, β-caryophyllene) as well as previously studied VOCs (i.e., isoprene, α-pinene). Using a field deployable chemical-ionization time-of-flight mass spectrometer (CI-ToFMS), benzene cluster cations demonstrated high sensitivity (> 1 ncps ppt−1) to DMS, isoprene, and α-pinene standards. Parallel measurements conducted using a chemical-ionization quadrupole mass spectrometer, with a much weaker electric field, demonstrated that ion–molecule reactions likely proceed through a combination of ligand-switching and directmore » charge transfer mechanisms. Laboratory tests suggest that benzene cluster cations may be suitable for the selective ionization of sesquiterpenes, where minimal fragmentation (< 25 %) was observed for the detection of β-caryophyllene, a bicyclic sesquiterpene. The in-field stability of benzene cluster cations using CI-ToFMS was examined in the marine boundary layer during the High Wind Gas Exchange Study (HiWinGS). The use of benzene cluster cation chemistry for the selective detection of DMS was validated against an atmospheric pressure ionization mass spectrometer, where measurements from the two instruments were highly correlated (R2 > 0.95, 10 s averages) over a wide range of sampling conditions.« less

  13. CONSTRAINTS ON DARK MATTER ANNIHILATION IN CLUSTERS OF GALAXIES FROM DIFFUSE RADIO EMISSION

    SciTech Connect (OSTI)

    Storm, Emma; Jeltema, Tesla E.; Profumo, Stefano; Rudnick, Lawrence

    2013-05-10

    Annihilation of dark matter can result in the production of stable Standard Model particles including electrons and positrons that, in the presence of magnetic fields, lose energy via synchrotron radiation, observable as radio emission. Galaxy clusters are excellent targets to search for or to constrain the rate of dark matter annihilation, as they are both massive and dark matter dominated. In this study, we place limits on dark matter annihilation in a sample of nearby clusters using upper limits on the diffuse radio emission, low levels of observed diffuse emission, or detections of radio mini-halos. We find that the strongest limits on the annihilation cross section are better than limits derived from the non-detection of clusters in the gamma-ray band by a factor of {approx}3 or more when the same annihilation channel and substructure model, but different best-case clusters, are compared. The limits on the cross section depend on the assumed amount of substructure, varying by as much as two orders of magnitude for increasingly optimistic substructure models as compared to a smooth Navarro-Frenk-White profile. In our most optimistic case, using the results of the Phoenix Project, we find that the derived limits reach below the thermal relic cross section of 3 Multiplication-Sign 10{sup -26} cm{sup 3} s{sup -1} for dark matter masses as large as 400 GeV, for the b b-bar annihilation channel. We discuss uncertainties due to the limited available data on the magnetic field structure of individual clusters. We also report the discovery of diffuse radio emission from the central 30-40 kpc regions of the groups M49 and NGC 4636.

  14. Water-Gas Sampling | Open Energy Information

    Open Energy Info (EERE)

    Water-Gas Sampling (Redirected from Water-Gas Samples) Redirect page Jump to: navigation, search REDIRECT Downhole Fluid Sampling Retrieved from "http:en.openei.orgw...

  15. Category:Water Sampling | Open Energy Information

    Open Energy Info (EERE)

    Water Sampling Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the Water Sampling page? For detailed information on Water Sampling as...

  16. Inertial impaction air sampling device

    DOE Patents [OSTI]

    Dewhurst, K.H.

    1987-12-10

    An inertial impactor to be used in an air sampling device for collection of respirable size particles in ambient air which may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry. 3 figs.

  17. Inertial impaction air sampling device

    DOE Patents [OSTI]

    Dewhurst, K.H.

    1990-05-22

    An inertial impactor is designed which is to be used in an air sampling device for collection of respirable size particles in ambient air. The device may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry. 3 figs.

  18. Inertial impaction air sampling device

    DOE Patents [OSTI]

    Dewhurst, Katharine H.

    1990-01-01

    An inertial impactor to be used in an air sampling device for collection of respirable size particles in ambient air which may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry.

  19. The Ocean Sampling Day Consortium

    SciTech Connect (OSTI)

    Kopf, Anna; Bicak, Mesude; Kottmann, Renzo; Schnetzer, Julia; Kostadinov, Ivaylo; Lehmann, Katja; Fernandez-Guerra, Antonio; Jeanthon, Christian; Rahav, Eyal; Ullrich, Matthias; Wichels, Antje; Gerdts, Gunnar; Polymenakou, Paraskevi; Kotoulas, Giorgos; Siam, Rania; Abdallah, Rehab Z.; Sonnenschein, Eva C.; Cariou, Thierry; O’Gara, Fergal; Jackson, Stephen; Orlic, Sandi; Steinke, Michael; Busch, Julia; Duarte, Bernardo; Caçador, Isabel; Canning-Clode, João; Bobrova, Oleksandra; Marteinsson, Viggo; Reynisson, Eyjolfur; Loureiro, Clara Magalhães; Luna, Gian Marco; Quero, Grazia Marina; Löscher, Carolin R.; Kremp, Anke; DeLorenzo, Marie E.; Øvreås, Lise; Tolman, Jennifer; LaRoche, Julie; Penna, Antonella; Frischer, Marc; Davis, Timothy; Katherine, Barker; Meyer, Christopher P.; Ramos, Sandra; Magalhães, Catarina; Jude-Lemeilleur, Florence; Aguirre-Macedo, Ma Leopoldina; Wang, Shiao; Poulton, Nicole; Jones, Scott; Collin, Rachel; Fuhrman, Jed A.; Conan, Pascal; Alonso, Cecilia; Stambler, Noga; Goodwin, Kelly; Yakimov, Michael M.; Baltar, Federico; Bodrossy, Levente; Van De Kamp, Jodie; Frampton, Dion M. F.; Ostrowski, Martin; Van Ruth, Paul; Malthouse, Paul; Claus, Simon; Deneudt, Klaas; Mortelmans, Jonas; Pitois, Sophie; Wallom, David; Salter, Ian; Costa, Rodrigo; Schroeder, Declan C.; Kandil, Mahrous M.; Amaral, Valentina; Biancalana, Florencia; Santana, Rafael; Pedrotti, Maria Luiza; Yoshida, Takashi; Ogata, Hiroyuki; Ingleton, Tim; Munnik, Kate; Rodriguez-Ezpeleta, Naiara; Berteaux-Lecellier, Veronique; Wecker, Patricia; Cancio, Ibon; Vaulot, Daniel; Bienhold, Christina; Ghazal, Hassan; Chaouni, Bouchra; Essayeh, Soumya; Ettamimi, Sara; Zaid, El Houcine; Boukhatem, Noureddine; Bouali, Abderrahim; Chahboune, Rajaa; Barrijal, Said; Timinouni, Mohammed; El Otmani, Fatima; Bennani, Mohamed; Mea, Marianna; Todorova, Nadezhda; Karamfilov, Ventzislav; ten Hoopen, Petra; Cochrane, Guy; L’Haridon, Stephane; Bizsel, Kemal Can; Vezzi, Alessandro; Lauro, Federico M.; Martin, Patrick; Jensen, Rachelle M.; Hinks, Jamie; Gebbels, Susan; Rosselli, Riccardo; De Pascale, Fabio; Schiavon, Riccardo; dos Santos, Antonina; Villar, Emilie; Pesant, Stéphane; Cataletto, Bruno; Malfatti, Francesca; Edirisinghe, Ranjith; Silveira, Jorge A. Herrera; Barbier, Michele; Turk, Valentina; Tinta, Tinkara; Fuller, Wayne J.; Salihoglu, Ilkay; Serakinci, Nedime; Ergoren, Mahmut Cerkez; Bresnan, Eileen; Iriberri, Juan; Nyhus, Paul Anders Fronth; Bente, Edvardsen; Karlsen, Hans Erik; Golyshin, Peter N.; Gasol, Josep M.; Moncheva, Snejana; Dzhembekova, Nina; Johnson, Zackary; Sinigalliano, Christopher David; Gidley, Maribeth Louise; Zingone, Adriana; Danovaro, Roberto; Tsiamis, George; Clark, Melody S.; Costa, Ana Cristina; El Bour, Monia; Martins, Ana M.; Collins, R. Eric; Ducluzeau, Anne-Lise; Martinez, Jonathan; Costello, Mark J.; Amaral-Zettler, Linda A.; Gilbert, Jack A.; Davies, Neil; Field, Dawn; Glöckner, Frank Oliver

    2015-06-19

    In this study, Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapshot of the marine microbial biodiversity and function of the world’s oceans. It is a simultaneous global mega-sequencing campaign aiming to generate the largest standardized microbial data set in a single day. This will be achievable only through the coordinated efforts of an Ocean Sampling Day Consortium, supportive partnerships and networks between sites. This commentary outlines the establishment, function and aims of the Consortium and describes our vision for a sustainable study of marine microbial communities and their embedded functional traits.

  20. Rotational fluctuation of molecules in quantum clusters. I. Path integral hybrid Monte Carlo algorithm

    SciTech Connect (OSTI)

    Miura, Shinichi [Institute for Molecular Science, 38 Myodaiji, Okazaki 444-8585 (Japan)

    2007-03-21

    In this paper, we present a path integral hybrid Monte Carlo (PIHMC) method for rotating molecules in quantum fluids. This is an extension of our PIHMC for correlated Bose fluids [S. Miura and J. Tanaka, J. Chem. Phys. 120, 2160 (2004)] to handle the molecular rotation quantum mechanically. A novel technique referred to be an effective potential of quantum rotation is introduced to incorporate the rotational degree of freedom in the path integral molecular dynamics or hybrid Monte Carlo algorithm. For a permutation move to satisfy Bose statistics, we devise a multilevel Metropolis method combined with a configurational-bias technique for efficiently sampling the permutation and the associated atomic coordinates. Then, we have applied the PIHMC to a helium-4 cluster doped with a carbonyl sulfide molecule. The effects of the quantum rotation on the solvation structure and energetics were examined. Translational and rotational fluctuations of the dopant in the superfluid cluster were also analyzed.

  1. Migration of defect clusters and xenon-vacancy clusters in uranium dioxide

    SciTech Connect (OSTI)

    Chen, Dong; Gao, Fei; Deng, Huiqiu; Hu, Wangyu; Sun, Xin

    2014-07-01

    The possible transition states, minimum energy paths and migration mechanisms of defect clusters and xenon-vacancy defect clusters in uranium dioxide have been investigated using the dimer and the nudged elastic-band methods. The nearby O atom can easily hop into the oxygen vacancy position by overcoming a small energy barrier, which is much lower than that for the migration of a uranium vacancy. A simulation for a vacancy cluster consisting of two oxygen vacancies reveals that the energy barrier of the divacancy migration tends to decrease with increasing the separation distance of divacancy. For an oxygen interstitial, the migration barrier for the hopping mechanism is almost three times larger than that for the exchange mechanism. Xe moving between two interstitial sites is unlikely a dominant migration mechanism considering the higher energy barrier. A net migration process of a Xe-vacancy pair containing an oxygen vacancy and a xenon interstitial is identified by the NEB method. We expect the oxygen vacancy-assisted migration mechanism to possibly lead to a long distance migration of the Xe interstitials in UO2. The migration of defect clusters involving Xe substitution indicates that Xe atom migrating away from the uranium vacancy site is difficult.

  2. MEASURING THE ULTIMATE HALO MASS OF GALAXY CLUSTERS: REDSHIFTS AND MASS PROFILES FROM THE HECTOSPEC CLUSTER SURVEY (HeCS)

    SciTech Connect (OSTI)

    Rines, Kenneth; Geller, Margaret J.; Kurtz, Michael J.; Diaferio, Antonaldo E-mail: diaferio@ph.unito.it

    2013-04-10

    The infall regions of galaxy clusters represent the largest gravitationally bound structures in a {Lambda}CDM universe. Measuring cluster mass profiles into the infall regions provides an estimate of the ultimate mass of these halos. We use the caustic technique to measure cluster mass profiles from galaxy redshifts obtained with the Hectospec Cluster Survey (HeCS), an extensive spectroscopic survey of galaxy clusters with MMT/Hectospec. We survey 58 clusters selected by X-ray flux at 0.1 < z < 0.3. The survey includes 22,680 unique MMT/Hectospec redshifts for individual galaxies; 10,145 of these galaxies are cluster members. For each cluster, we acquired high signal-to-noise spectra for {approx}200 cluster members and a comparable number of foreground/background galaxies. The cluster members trace out infall patterns around the clusters. The members define a very narrow red sequence. We demonstrate that the determination of velocity dispersion is insensitive to the inclusion of bluer members (a small fraction of the cluster population). We apply the caustic technique to define membership and estimate the mass profiles to large radii. The ultimate halo mass of clusters (the mass that remains bound in the far future of a {Lambda}CDM universe) is on average (1.99 {+-} 0.11)M{sub 200}, a new observational cosmological test in essential agreement with simulations. Summed profiles binned in M{sub 200} and in L{sub X} demonstrate that the predicted Navarro-Frenk-White form of the density profile is a remarkably good representation of the data in agreement with weak lensing results extending to large radius. The concentration of these summed profiles is also consistent with theoretical predictions.

  3. WHAT DOES CLUSTERING TELL US ABOUT THE BUILDUP OF THE RED SEQUENCE?

    SciTech Connect (OSTI)

    Tinker, Jeremy L.; Wetzel, Andrew R.

    2010-08-10

    We analyze the clustering of red and blue galaxies from four samples spanning a redshift range of 0.4 < z < 2.0 to test the various scenarios by which galaxies evolve onto the red sequence. The data are taken from the UKIDSS Ultra Deep Survey, DEEP2, and COMBO-17. The use of clustering allows us to determine what fraction of the red sequence is made up of central galaxies and satellite galaxies. At all redshifts, including z = 0, the data are consistent with {approx}60% of satellite galaxies being red or quenched, implying that {approx}1/3 of the red sequence is comprised of satellite galaxies. More than three-fourths of red satellite galaxies were moved to the red sequence after they were accreted onto a larger halo. The constant fraction of satellite galaxies that are red yields a quenching time for satellite galaxies that depends on redshift in the same way as halo dynamical times: t{sub Q} {approx} (1 + z){sup -1.5}. In three of the four samples, the data favor a model in which red central galaxies are a random sample of all central galaxies; there is no preferred halo mass scale at which galaxies make the transition from star-forming to red and dead. The large errors on the fourth sample inhibit any conclusions. Theoretical models in which star formation is quenched above a critical halo mass are excluded by these data. A scenario in which mergers create red central galaxies imparts a weaker correlation between halo mass and central galaxy color, but even the merger scenario creates tension with red galaxy clustering at redshifts above 0.5. These results suggest that the mechanism by which central galaxies become red evolves from z = 0.5 to z = 0.

  4. Changing ionization conditions in SDSS galaxies with active galactic nuclei as a function of environment from pairs to clusters

    SciTech Connect (OSTI)

    Khabiboulline, Emil T.; Steinhardt, Charles L.; Silverman, John D.; Ellison, Sara L.; Mendel, J. Trevor; Patton, David R.

    2014-11-01

    We study how active galactic nucleus (AGN) activity changes across environments from galaxy pairs to clusters using 143,843 galaxies with z < 0.2 from the Sloan Digital Sky Survey. Using a refined technique, we apply a continuous measure of AGN activity, characteristic of the ionization state of the narrow-line emitting gas. Changes in key emission-line ratios ([N II] λ6548/Hα, [O III] λ5007/Hβ) between different samples allow us to disentangle different environmental effects while removing contamination. We confirm that galaxy interactions enhance AGN activity. However, conditions in the central regions of clusters are inhospitable for AGN activity even if galaxies are in pairs. These results can be explained through models of gas dynamics in which pair interactions stimulate the transfer of gas to the nucleus and clusters suppress gas availability for accretion onto the central black hole.

  5. Clustering effects in ionic polymers: Molecular dynamics simulations

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

    Agrawal, Anupriya; Perahia, Dvora; Grest, Gary S.

    2015-08-18

    Ionic clusters control the structure, dynamics, and transport in soft matter. Incorporating a small fraction of ionizable groups in polymers substantially reduces the mobility of the macromolecules in melts. Furthermore, these ionic groups often associate into random clusters in melts, where the distribution and morphology of the clusters impact the transport in these materials. Here, using molecular dynamic simulations we demonstrate a clear correlation between cluster size and morphology with the polymer mobility in melts of sulfonated polystyrene. We show that in low dielectric media ladderlike clusters that are lower in energy compared with spherical assemblies are formed. Reducing themore » electrostatic interactions by enhancing the dielectric constant leads to morphological transformation from ladderlike clusters to globular assemblies. Finally, decrease in electrostatic interaction significantly enhances the mobility of the polymer.« less

  6. Experimental nanocalorimetry of protonated and deprotonated water clusters

    SciTech Connect (OSTI)

    Boulon, Julien; Braud, Isabelle; Zamith, Sébastien; Labastie, Pierre; L’Hermite, Jean-Marc

    2014-04-28

    An experimental nanocalorimetric study of mass selected protonated (H{sub 2}O){sub n}H{sup +} and deprotonated (H{sub 2}O){sub n−1}OH{sup −} water clusters is reported in the size range n = 20–118. Water cluster's heat capacities exhibit a change of slope at size dependent temperatures varying from 90 to 140 K, which is ascribed to phase or structural transition. For both anionic and cationic species, these transition temperatures strongly vary at small sizes, with higher amplitude for protonated than for deprotonated clusters, and change more smoothly above roughly n ≈ 35. There is a correlation between bonding energies and transition temperatures, which is split in two components for protonated clusters while only one component is observed for deprotonated clusters. These features are tentatively interpreted in terms of structural properties of water clusters.

  7. Clustering effects in ionic polymers: Molecular dynamics simulations

    SciTech Connect (OSTI)

    Agrawal, Anupriya; Perahia, Dvora; Grest, Gary S.

    2015-08-18

    Ionic clusters control the structure, dynamics, and transport in soft matter. Incorporating a small fraction of ionizable groups in polymers substantially reduces the mobility of the macromolecules in melts. Furthermore, these ionic groups often associate into random clusters in melts, where the distribution and morphology of the clusters impact the transport in these materials. Here, using molecular dynamic simulations we demonstrate a clear correlation between cluster size and morphology with the polymer mobility in melts of sulfonated polystyrene. We show that in low dielectric media ladderlike clusters that are lower in energy compared with spherical assemblies are formed. Reducing the electrostatic interactions by enhancing the dielectric constant leads to morphological transformation from ladderlike clusters to globular assemblies. Finally, decrease in electrostatic interaction significantly enhances the mobility of the polymer.

  8. Ground-state structures of Hafnium clusters

    SciTech Connect (OSTI)

    Ng, Wei Chun; Yoon, Tiem Leong; Lim, Thong Leng

    2015-04-24

    Hafnium (Hf) is a very large tetra-valence d-block element which is able to form relatively long covalent bond. Researchers are interested to search for substitution to silicon in the semi-conductor industry. We attempt to obtain the ground-state structures of small Hf clusters at both empirical and density-functional theory (DFT) levels. For calculations at the empirical level, charge-optimized many-body functional potential (COMB) is used. The lowest-energy structures are obtained via a novel global-minimum search algorithm known as parallel tempering Monte-Carlo Basin-Hopping and Genetic Algorithm (PTMBHGA). The virtue of using COMB potential for Hf cluster calculation lies in the fact that by including the charge optimization at the valence shells, we can encourage the formation of proper bond hybridization, and thus getting the correct bond order. The obtained structures are further optimized using DFT to ensure a close proximity to the ground-state.

  9. Measuring Complementary Electronic Structure Properties of both Deposited and Gas Phase Clusters using STM, UPS, and PES: Size-Selected Clusters on Surfaces

    SciTech Connect (OSTI)

    Bowen, Kit H.

    2014-03-05

    In this project, we studied size-selected cluster interactions with surfaces, with other clusters on surfaces, and with external stimuli. These studies focused on mobility as a function of cluster size, surface morphologies as a function of composition and coverage, ion-induced modification and reactivity of clusters as a function of composition, the structural evolution of cluster cuboids culminating in the characterization of theoretically-predicted baby crystal clusters, and unusual fractal pattern formation due to deposition.

  10. Sandia National Labs: PCNSC: Departments: Small Science Cluster Business

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

    Office Sciences Semiconductor & Optical Sciences Energy Sciences Small Science Cluster Business Office News Partnering Research Georgia Rivera-Gronager Georgia Rivera-Gronager Manager Beverly Eppinga Beverly Eppinga Sr. Mgt. Asst. Departments Small Science Cluster Business Office The Small Science Cluster Business Office provides administrative support to the Physical, Chemical, & Nano Sciences Center's organizational operations; the Materials and Process Sciences Center's

  11. Jefferson Lab Awards Contract for Next Cluster Computer | Jefferson Lab

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

    Awards Contract for Next Cluster Computer Jefferson Lab Awards Contract for Next Cluster Computer February 8, 2007 Newport News, Va. - The U.S. Department of Energy's Thomas Jefferson National Accelerator Facility has awarded the contract for providing the components of its next major cluster computer installation to Koi Computers, a woman-owned, certified Small Disadvantaged Business located in Lombard, Ill. Koi won the $1.1 million contract with its bid to provide 432 dual processor, dual core

  12. NERSC Fields Its First Student Cluster Competition Team

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

    Fields Its First Student Cluster Competition Team NERSC Fields Its First Student Cluster Competition Team June 6, 2016 studentclusterteam Top row, left to right: Davina Ngai, Kristi Arroyo and Grace Rodriguez Gomez. Bottom row, left to right: Yong Li Dich, Ruoyun Zheng and Elizabeth Wang. Five former NERSC interns and one current intern have joined forces to participate in the Student Cluster Competition at ISC16, June 20-22 in Frankfurt, Germany, marking the first time that NERSC has fielded a

  13. Solvation Properties of Microhydrated Sulfate Anion Clusters: Insights from

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

    abInitio Calculations | Argonne Leadership Computing Facility Solvation Properties of Microhydrated Sulfate Anion Clusters: Insights from abInitio Calculations Authors: Wan, Q., Spanu, L., Galli, G. Sulfate-water clusters play an important role in environmental and industrial processes, yet open questions remain on their physical and chemical properties. We investigated the smallest hydrated sulfate anion clusters believed to have a full solvation shell, with 12 or 13 water molecules. We

  14. THE INFRARED SPECTROSCOPY OF NEUTRAL POLYCYCLIC AROMATIC HYDROCARBON CLUSTERS

    SciTech Connect (OSTI)

    Ricca, Alessandra; Bauschlicher, Charles W. Jr.; Allamandola, Louis J. E-mail: Charles.W.Bauschlicher@nasa.gov

    2013-10-10

    The mid-infrared spectra of neutral homogeneous polycyclic aromatic hydrocarbon (PAH) clusters have been computed using density functional theory including an empirical correction for dispersion. The C-H out-of-plane bending modes are redshifted for all the clusters considered in this work. The magnitude of the redshift and the peak broadening are dependent on PAH size, shape, and on the PAH arrangement in the cluster.

  15. Structure of overheated metal clusters: MD simulation study

    SciTech Connect (OSTI)

    Vorontsov, Alexander

    2015-08-17

    The structure of overheated metal clusters appeared in condensation process was studied by computer simulation techniques. It was found that clusters with size larger than several tens of atoms have three layers: core part, intermediate dense packing layer and a gas- like shell with low density. The change of the size and structure of these layers with the variation of internal energy and the size of cluster is discussed.

  16. LoCuSS: A COMPARISON OF CLUSTER MASS MEASUREMENTS FROM XMM-NEWTON AND SUBARU-TESTING DEVIATION FROM HYDROSTATIC EQUILIBRIUM AND NON-THERMAL PRESSURE SUPPORT

    SciTech Connect (OSTI)

    Zhang, Yu-Ying; Okabe, Nobuhiro; Finoguenov, Alexis; Smith, Graham P.; Sanderson, Alastair J. R.; Piffaretti, Rocco; Valdarnini, Riccardo; Evrard, August E.; Mazzotta, Pasquale; Marrone, Daniel P.

    2010-03-10

    We compare X-ray hydrostatic and weak-lensing mass estimates for a sample of 12 clusters that have been observed with both XMM-Newton and Subaru. At an over-density of DELTA = 500, we obtain 1 - M {sup X}/M {sup WL} = 0.01 +- 0.07 for the whole sample. We also divided the sample into undisturbed and disturbed sub-samples based on quantitative X-ray morphologies using asymmetry and fluctuation parameters, obtaining 1 - M {sup X}/M {sup WL} = 0.09 +- 0.06 and -0.06 +- 0.12 for the undisturbed and disturbed clusters, respectively. In addition to non-thermal pressure support, there may be a competing effect associated with adiabatic compression and/or shock heating which leads to overestimate of X-ray hydrostatic masses for disturbed clusters, for example, in the famous merging cluster A1914. Despite the modest statistical significance of the mass discrepancy, on average, in the undisturbed clusters, we detect a clear trend of improving agreement between M {sup X} and M {sup WL} as a function of increasing over-density, M{sup X}/M{sup WL}=(0.908+-0.004)+(0.187+-0.010){center_dot} log{sub 10}(DELTA/500). We also examine the gas mass fractions, f{sub gas} = M {sup gas}/M {sup WL}, finding that they are an increasing function of cluster radius, with no dependence on dynamical state, in agreement with predictions from numerical simulations. Overall, our results demonstrate that XMM-Newton and Subaru are a powerful combination for calibrating systematic uncertainties in cluster mass measurements.

  17. Three-dimensional Modeling of Fracture Clusters in Geeothermal Reservoirs

    Broader source: Energy.gov [DOE]

    Three-dimensional Modeling of Fracture Clusters in Geeothermal Reservoirs presentation at the April 2013 peer review meeting held in Denver, Colorado.

  18. Cluster Analysis-Based Approaches for Geospatiotemporal Data...

    Office of Scientific and Technical Information (OSTI)

    Cluster Analysis-Based Approaches for Geospatiotemporal Data Mining of Massive Data Sets for Identification of Forest Threats Mills, Richard T ORNL ORNL; Hoffman, Forrest M...

  19. in High Performance Computing Computer System, Cluster, and Networking...

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

    iSSH v. Auditd: Intrusion Detection in High Performance Computing Computer System, Cluster, and Networking Summer Institute David Karns, New Mexico State University Katy Protin,...

  20. Field Observation GoAmazon Neutral cluster Air Ion Spectrometer...

    Office of Scientific and Technical Information (OSTI)

    ... In this work, we used novel instrumentation including the neutral cluster and air ion ... Then. we detected what were probably anthropogenic pollution plumes from Manaus. and ...

  1. Three-dimensional Modeling of Fracture Clusters in Geothermal...

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

    Reservoirs; 2010 Geothermal Technology Program Peer Review Report Three-dimensional Modeling of Fracture Clusters in Geothermal Reservoirs; 2010 Geothermal Technology Program Peer ...

  2. Optimizing Cluster Heads for Energy Efficiency in Large-Scale...

    Office of Scientific and Technical Information (OSTI)

    Optimizing Cluster Heads for Energy Efficiency in Large-Scale Heterogeneous Wireless Sensor Networks Gu, Yi; Wu, Qishi; Rao, Nageswara S. V. Hindawi Publishing Corporation None...

  3. Cluster expansion modeling and Monte Carlo simulation of alnico...

    Office of Scientific and Technical Information (OSTI)

    Accepted Manuscript: Cluster expansion modeling and Monte Carlo simulation of alnico 5-7 permanent magnets This content will become publicly available on March 5, 2016 Prev Next...

  4. Sequential desorption energy of hydrogen from nickel clusters

    SciTech Connect (OSTI)

    Deepika,; Kumar, Rakesh; R, Kamal Raj.; Kumar, T. J. Dhilip

    2015-06-24

    We report reversible Hydrogen adsorption on Nickel clusters, which act as a catalyst for solid state storage of Hydrogen on a substrate. First-principles technique is employed to investigate the maximum number of chemically adsorbed Hydrogen molecules on Nickel cluster. We observe a maximum of four Hydrogen molecules adsorbed per Nickel atom, but the average Hydrogen molecules adsorbed per Nickel atom decrease with cluster size. The dissociative chemisorption energy per Hydrogen molecule and sequential desorption energy per Hydrogen atom on Nickel cluster is found to decrease with number of adsorbed Hydrogen molecules, which on optimization may help in economical storage and regeneration of Hydrogen as a clean energy carrier.

  5. Optimizing Cluster Heads for Energy Efficiency in Large-Scale...

    Office of Scientific and Technical Information (OSTI)

    clustering is generally considered as an efficient and scalable way to facilitate the management and operation of such large-scale networks and minimize the total energy...

  6. Analysis of a Cluster Strategy for Near Term Hydrogen Infrastructure...

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

    Analysis of a Cluster Strategy for Near Term Hydrogen Infrastructure Rollout in Southern California Presentation at the Renewable Hydrogen Workshop, Nov. 16, 2009, in Palm Springs, ...

  7. High Temperature Membrane with HUmidification-Independent Cluster...

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

    High Temperature Membrane with HUmidification-Independent Cluster Structure A presentation ... More Documents & Publications High Temperature Membrane Working Group New Proton ...

  8. Ab initio calculations in three-body cluster systems (Journal...

    Office of Scientific and Technical Information (OSTI)

    Language: English Subject: 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; CLUSTER MODEL; GROUND STATES; GROUP THEORY; HELIUM 4; HELIUM 6; NEUTRONS; NUCLEAR STRUCTURE; RESONATING-GROUP ...

  9. Gate-tunable exchange coupling between cobalt clusters on graphene...

    Office of Scientific and Technical Information (OSTI)

    DOE PAGES Search Results Publisher's Accepted Manuscript: Gate-tunable exchange coupling between cobalt clusters on graphene Title: Gate-tunable exchange coupling between cobalt ...

  10. Backups Using Storage Clusters! Joshua T. A. Davies ...

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

    Cindy Valdez, Timothy Hemphill (DCS-CSD) LA-UR-14-26017 Overview * The Project * The Cluster * Software * Issues * Conclusions * Future Work http:www.dataprotection.comimages...

  11. Supercomputing on a Shoestring: Cluster Computers at JLab | Jefferson...

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

    which describe the distribution of electric charge and current inside the nucleon. Apple To calculate the solution to a science problem, a cluster computer slices space up...

  12. Cluster-based architecture for fault-tolerant quantum computation...

    Office of Scientific and Technical Information (OSTI)

    In this cluster-based architecture, concatenated computation is implemented in a quite different way from the usual circuit-based architecture where physical gates are recursively ...

  13. Using Cluster Road Mapping to Determine Strategic Clean Energy Direction

    Office of Energy Efficiency and Renewable Energy (EERE)

    This document contains the transcript for the Using Cluster Roadmapping to Determine Your Strategic Clean Energy Direction webinar held on May 16, 2013.

  14. Sample rotating turntable kit for infrared spectrometers

    DOE Patents [OSTI]

    Eckels, Joel Del (Livermore, CA); Klunder, Gregory L. (Oakland, CA)

    2008-03-04

    An infrared spectrometer sample rotating turntable kit has a rotatable sample cup containing the sample. The infrared spectrometer has an infrared spectrometer probe for analyzing the sample and the rotatable sample cup is adapted to receive the infrared spectrometer probe. A reflectance standard is located in the rotatable sample cup. A sleeve is positioned proximate the sample cup and adapted to receive the probe. A rotator rotates the rotatable sample cup. A battery is connected to the rotator.

  15. MgO-Supported Cluster Catalysts with Pt-Ru Interactions Prepared from Pt3Ru6(CO)21(u3-H)(u-H)3

    SciTech Connect (OSTI)

    Chotisuwan,S.; Wittapyakun, J.; Lobo-Lapidus, R.; Gates, B.

    2007-01-01

    Bimetallic MgO-supported catalysts were prepared by adsorption of Pt{sub 3}Ru{sub 6}(CO){sub 21}({mu}{sub 3}-H)({mu}-H){sub 3} on porous MgO. Characterization of the supported clusters by infrared (IR) spectroscopy showed that the adsorbed species were still in the form of metal carbonyls. The supported clusters were decarbonylated by treatment in flowing helium at 300 C, as shown by IR and extended X-ray absorption fine structure (EXAFS) data, and the resulting supported PtRu clusters were shown by EXAFS spectroscopy to have metal frames that retained Pt-Ru bonds but were slightly restructured relative to those of the precursor; the average cluster size was almost unchanged as a result of the decarbonylation. These are among the smallest reported bimetallic clusters of group-8 metals. The decarbonylated sample catalyzed ethylene hydrogenation with an activity similar to that reported previously for {gamma}-Al{sub 2}O{sub 3}-supported clusters prepared in nearly the same way and having nearly the same structure. Both samples were also active for n-butane hydrogenolysis, with the MgO-supported catalyst being more active than the {gamma}-Al{sub 2}O{sub 3}-supported catalyst.

  16. Characterization of the Praesepe star cluster by photometry and proper motions with 2MASS, PPMXL, and Pan-STARRS

    SciTech Connect (OSTI)

    Wang, P. F.; Chen, W. P.; Lin, C. C.; Huang, C. K.; Panwar, N.; Lee, C. H.; Pandey, A. K.; Tsai, M. F.; Tang, C.-H.; Goldman, B.; Burgett, W. S.; Chambers, K. C.; Flewelling, H.; Heasley, J. N.; Hodapp, K. W.; Huber, M. E.; Jedicke, R.; Kaiser, N.; Draper, P. W.; Grav, T.; and others

    2014-03-20

    Membership identification is the first step in determining the properties of a star cluster. Low-mass members in particular could be used to trace the dynamical history, such as mass segregation, stellar evaporation, or tidal stripping, of a star cluster in its Galactic environment. We identified member candidates of the intermediate-age Praesepe cluster (M44) with stellar masses ?0.11-2.4 M {sub ?}, using Panoramic Survey Telescope And Rapid Response System and Two Micron All Sky Survey photometry, and PPMXL proper motions. Within a sky area of 3 radius, 1040 candidates are identified, of which 96 are new inclusions. Using the same set of selection criteria on field stars, an estimated false positive rate of 16% was determined, suggesting that 872 of the candidates are true members. This most complete and reliable membership list allows us to favor the BT-Settl model over other stellar models. The cluster shows a distinct binary track above the main sequence, with a binary frequency of 20%-40%, and a high occurrence rate of similar mass pairs. The mass function is consistent with that of the disk population but shows a deficit of members below 0.3 solar masses. A clear mass segregation is evidenced, with the lowest-mass members in our sample being evaporated from this disintegrating cluster.

  17. Apparatus and method for handheld sampling

    DOE Patents [OSTI]

    Staab, Torsten A.

    2005-09-20

    The present invention includes an apparatus, and corresponding method, for taking a sample. The apparatus is built around a frame designed to be held in at least one hand. A sample media is used to secure the sample. A sample media adapter for securing the sample media is operated by a trigger mechanism connectively attached within the frame to the sample media adapter.

  18. Environmental surveillance master sampling schedule

    SciTech Connect (OSTI)

    Bisping, L E

    1992-01-01

    Environmental surveillance of the Hanford Site and surrounding areas is conducted by the Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE). This document contains the planned schedule for routine sample collection for the Surface Environmental Surveillance Project (SESP) and Ground-Water Monitoring Project. Samples for radiological analyses include Air-Particulate Filter, gases and vapor; Water/Columbia River, Onsite Pond, Spring, Irrigation, and Drinking; Foodstuffs/Animal Products including Whole Milk, Poultry and Eggs, and Beef; Foodstuffs/Produce including Leafy Vegetables, Vegetables, and Fruit; Foodstuffs/Farm Products including Wine, Wheat and Alfalfa; Wildlife; Soil; Vegetation; and Sediment. Direct Radiation Measurements include Terrestrial Locations, Columbia River Shoreline Locations, and Onsite Roadway, Railway and Aerial, Radiation Surveys.

  19. The Ocean Sampling Day Consortium

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

    Kopf, Anna; Bicak, Mesude; Kottmann, Renzo; Schnetzer, Julia; Kostadinov, Ivaylo; Lehmann, Katja; Fernandez-Guerra, Antonio; Jeanthon, Christian; Rahav, Eyal; Ullrich, Matthias; et al

    2015-06-19

    In this study, Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapshot of the marine microbial biodiversity and function of the world’s oceans. It is a simultaneous global mega-sequencing campaign aiming to generate the largest standardized microbial data set in a single day. This will be achievable only through the coordinated efforts of an Ocean Sampling Day Consortium, supportive partnerships and networks between sites. This commentary outlines the establishment, function and aims of the Consortium and describes our vision for a sustainable study of marine microbial communities and theirmore » embedded functional traits.« less

  20. Laboratory Access | Sample Preparation Laboratories

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

    Access Planning Ahead Planning Ahead Please complete the Beam Time Request (BTR) and Support Request forms thourgh the User Portal. Thorough chemical and sample information must be included in your BTR. Support Request forms include a list of collaborators that require laboratory access and your group's laboratory equipment requests. Researcher safety is taken seriously at SLAC. Please remember that radioactive materials, nanomaterials, and biohazardous materials have additional safety

  1. Laboratory Waste | Sample Preparation Laboratories

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

    Laboratory Waste Sharps Broken Glass Containment Hazardous Waste All waste produced in the Sample Prep Labs should be appropriately disposed of at SLAC. You are prohibited to transport waste back to your home institution. Designated areas exist in the labs for sharps, broken glass, and hazardous waste. Sharps, broken glass, and hazardous waste must never be disposed of in the trash cans or sink drains. Containment Bottles, jars, and plastic bags are available for containing chemical waste. Place

  2. Water Clustering on Nanostructured Iron Oxide Films

    SciTech Connect (OSTI)

    Merte, L. R.; Bechstein, Ralf; Peng, Guowen; Rieboldt, Felix; Farberow, Carrie A.; Zeuthen, Helene; Knudsen, Jan; Laegsgaard, E.; Wendt, Stefen; Mavrikakis, Manos; Besenbacher, Fleming

    2014-06-30

    The adhesion of water to solid surfaces is characterized by the tendency to balance competing moleculemolecule and moleculesurface interactions. Hydroxyl groups form strong hydrogen bonds to water molecules and are known to substantially influence the wetting behaviour of oxide surfaces, but it is not well-understood how these hydroxyl groups and their distribution on a surface affect the molecular-scale structure at the interface. Here we report a study of water clustering on a moire-structured iron oxide thin film with a controlled density of hydroxyl groups. While large amorphous monolayer islands form on the are film, the hydroxylated iron oxide film acts as a hydrophilic nanotemplate, causing the formation of a regular array of ice-like hexameric nanoclusters. The formation of this ordered phase is localized at the nanometre scale; with increasing water coverage, ordered and amorphous water are found to coexist at adjacent hydroxylated and hydroxyl-free domains of the moire structure.

  3. Anion photoelectron spectroscopy of radicals and clusters

    SciTech Connect (OSTI)

    Travis, Taylor R.

    1999-12-16

    Anion photoelectron spectroscopy is used to study free radicals and clusters. The low-lying {sup 2}{Sigma} and {sup 2}{Pi} states of C{sub 2n}H (n = 1--4) have been studied. The anion photoelectron spectra yielded electron affinities, term values, and vibrational frequencies for these combustion and astrophysically relevant species. Photoelectron angular distributions allowed the author to correctly assign the electronic symmetry of the ground and first excited states and to assess the degree of vibronic coupling in C{sub 2}H and C{sub 4}H. Other radicals studied include NCN and I{sub 3}. The author was able to observe the low-lying singlet and triplet states of NCN for the first time. Measurement of the electron affinity of I{sub 3} revealed that it has a bound ground state and attachment of an argon atom to this moiety enabled him to resolve the symmetric stretching progression.

  4. Perspective: Water cluster mediated atmospheric chemistry

    SciTech Connect (OSTI)

    Vaida, Veronica

    2011-07-14

    The importance of water in atmospheric and environmental chemistry initiated recent studies with results documenting catalysis, suppression and anti-catalysis of thermal and photochemical reactions due to hydrogen bonding of reagents with water. Water, even one water molecule in binary complexes, has been shown by quantum chemistry to stabilize the transition state and lower its energy. However, new results underscore the need to evaluate the relative competing rates between reaction and dissipation to elucidate the role of water in chemistry. Water clusters have been used successfully as models for reactions in gas-phase, in aqueous condensed phases and at aqueous surfaces. Opportunities for experimental and theoretical chemical physics to make fundamental new discoveries abound. Work in this field is timely given the importance of water in atmospheric and environmental chemistry.

  5. Clustering of cycloidal wave energy converters

    DOE Patents [OSTI]

    Siegel, Stefan G.

    2016-03-29

    A wave energy conversion system uses a pair of wave energy converters (WECs) on respective active mountings on a floating platform, so that the separation of the WECs from each other or from a central WEC can be actively adjusted according to the wavelength of incident waves. The adjustable separation facilitates operation of the system to cancel reactive forces, which may be generated during wave energy conversion. Modules on which such pairs of WECs are mounted can be assembled with one or more central WECs to form large clusters in which reactive forces and torques can be made to cancel. WECs of different sizes can be employed to facilitate cancelation of reactive forces and torques.

  6. The electron screening puzzle and nuclear clustering

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

    Spitaleri, C.; Bertulani, C. A.; Fortunato, L.; Vitturi, A.

    2016-02-12

    Accurate measurements of nuclear reactions of astrophysical interest within, or close to, the Gamow peak show evidence of an unexpected effect attributed to the presence of atomic electrons in the target. The experiments need to include an effective "screening" potential to explain the enhancement of the cross sections at the lowest measurable energies. Despite various theoretical studies conducted over the past 20 years and numerous experimental measurements, a theory has not yet been found that can explain the cause of the exceedingly high values of the screening potential needed to explain the data. Furthermore, in this letter we show thatmore » instead of an atomic physics solution of the "electron screening puzzle", the reason for the large screening potential values is in fact due to clusterization effects in nuclear reactions, in particular for reaction involving light nuclei.« less

  7. Accelerating Subsurface Transport Simulation on Heterogeneous Clusters

    SciTech Connect (OSTI)

    Villa, Oreste; Gawande, Nitin A.; Tumeo, Antonino

    2013-09-23

    Reactive transport numerical models simulate chemical and microbiological reactions that occur along a flowpath. These models have to compute reactions for a large number of locations. They solve the set of ordinary differential equations (ODEs) that describes the reaction for each location through the Newton-Raphson technique. This technique involves computing a Jacobian matrix and a residual vector for each set of equation, and then solving iteratively the linearized system by performing Gaussian Elimination and LU decomposition until convergence. STOMP, a well known subsurface flow simulation tool, employs matrices with sizes in the order of 100x100 elements and, for numerical accuracy, LU factorization with full pivoting instead of the faster partial pivoting. Modern high performance computing systems are heterogeneous machines whose nodes integrate both CPUs and GPUs, exposing unprecedented amounts of parallelism. To exploit all their computational power, applications must use both the types of processing elements. For the case of subsurface flow simulation, this mainly requires implementing efficient batched LU-based solvers and identifying efficient solutions for enabling load balancing among the different processors of the system. In this paper we discuss two approaches that allows scaling STOMP's performance on heterogeneous clusters. We initially identify the challenges in implementing batched LU-based solvers for small matrices on GPUs, and propose an implementation that fulfills STOMP's requirements. We compare this implementation to other existing solutions. Then, we combine the batched GPU solver with an OpenMP-based CPU solver, and present an adaptive load balancer that dynamically distributes the linear systems to solve between the two components inside a node. We show how these approaches, integrated into the full application, provide speed ups from 6 to 7 times on large problems, executed on up to 16 nodes of a cluster with two AMD Opteron 6272

  8. 2011 Clusters, Nanocrystals & Nanostructures Gordon Research Conference

    SciTech Connect (OSTI)

    Lai-Sheng Wang

    2011-07-29

    Small particles have been at the heart of nanoscience since the birth of the field and now stand ready to make significant contributions to the big challenges of energy, health and sustainability. Atomic clusters show exquisite size-dependent electronic and magnetic properties and offer a new level of control in catalyses, sensors and biochips; functionalised nanocrystals offer remarkable optical properties and diverse applications in electronic devices, solar energy, and therapy. Both areas are complemented by a raft of recent advances in fabrication, characterization, and performance of a diversity of nanomaterials from the single atom level to nanowires, nanodevices, and biologically-inspired nanosystems. The goal of the 2011 Gordon Conference is thus to continue and enhance the interdisciplinary tradition of this series and discuss the most recent advances, fundamental scientific questions, and emerging applications of clusters, nanocrystals, and nanostructures. A single conference covering all aspects of nanoscience from fundamental issues to applications has the potential to create new ideas and stimulate cross fertilization. The meeting will therefore provide a balance among the three sub-components of the conference, true to its title, with a selection of new topics added to reflect rapid advances in the field. The open atmosphere of a Gordon conference, emphasizing the presentation of unpublished results and extensive discussions, is an ideal home for this rapidly developing field and will allow all participants to enjoy a valuable and stimulating experience. Historically, this Gordon conference has been oversubscribed, so we encourage all interested researchers from academia, industry, and government institutions to apply as early as possible. We also encourage all attendees to submit their latest results for presentation at the poster sessions. We anticipate that several posters will be selected for 'hot topic' oral presentations. Given the important

  9. Cosmology and astrophysics from relaxed galaxy clusters - IV: Robustly calibrating hydrostatic masses with weak lensing

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

    Applegate, D. E; Mantz, A.; Allen, S. W.; von der Linden, A.; Morris, R. G.; Hilbert, S.; Kelly, P. L.; Burke, D. L.; Ebeling, H.; Rapetti, D. A.; et al

    2016-02-04

    This is the fourth in a series of papers studying the astrophysics and cosmology of massive, dynamically relaxed galaxy clusters. Here, we use measurements of weak gravitational lensing from the Weighing the Giants project to calibrate Chandra X-ray measurements of total mass that rely on the assumption of hydrostatic equilibrium. This comparison of X-ray and lensing masses measures the combined bias of X-ray hydrostatic masses from both astrophysical and instrumental sources. While we cannot disentangle the two sources of bias, only the combined bias is relevant for calibrating cosmological measurements using relaxed clusters. Assuming a fixed cosmology, and within amore » characteristic radius (r2500) determined from the X-ray data, we measure a lensing to X-ray mass ratio of 0.96 ± 9% (stat) ± 9% (sys). We find no significant trends of this ratio with mass, redshift or the morphological indicators used to select the sample. Our results imply that any departures from hydrostatic equilibrium at these radii are offset by calibration errors of comparable magnitude, with large departures of tens-of-percent unlikely. In addition, we find a mean concentration of the sample measured from lensing data of c200 = 3.0+4.4–1.8. In conclusion, anticipated short-term improvements in lensing systematics, and a modest expansion of the relaxed lensing sample, can easily increase the measurement precision by 30–50%, leading to similar improvements in cosmological constraints that employ X-ray hydrostatic mass estimates, such as on Ωm from the cluster gas mass fraction.« less

  10. THE CLUSTER AND FIELD GALAXY ACTIVE GALACTIC NUCLEUS FRACTION AT z = 1-1.5: EVIDENCE FOR A REVERSAL OF THE LOCAL ANTICORRELATION BETWEEN ENVIRONMENT AND AGN FRACTION

    SciTech Connect (OSTI)

    Martini, Paul; Miller, E. D.; Bautz, M.; Brodwin, M.; Stanford, S. A.; Gonzalez, Anthony H.; Hickox, R. C.; Stern, D.; Eisenhardt, P. R.; Galametz, A.; Norman, D.; Dey, A.; Jannuzi, B. T.; Murray, S.; Jones, C.; Brown, M. J. I.

    2013-05-01

    The fraction of cluster galaxies that host luminous active galactic nuclei (AGNs) is an important probe of AGN fueling processes, the cold interstellar medium at the centers of galaxies, and how tightly black holes and galaxies co-evolve. We present a new measurement of the AGN fraction in a sample of 13 clusters of galaxies (M {>=} 10{sup 14} M{sub Sun }) at 1 < z < 1.5 selected from the Spitzer/IRAC Shallow Cluster Survey, as well as the field fraction in the immediate vicinity of these clusters, and combine these data with measurements from the literature to quantify the relative evolution of cluster and field AGN from the present to z {approx} 3. We estimate that the cluster AGN fraction at 1 < z < 1.5 is f{sub A} = 3.0{sup +2.4}{sub -1.4}% for AGNs with a rest-frame, hard X-ray luminosity greater than L{sub X,{sub H}} {>=} 10{sup 44} erg s{sup -1}. This fraction is measured relative to all cluster galaxies more luminous than M{sup *}{sub 3.6}(z) + 1, where M{sup *}{sub 3.6}(z) is the absolute magnitude of the break in the galaxy luminosity function at the cluster redshift in the IRAC 3.6 {mu}m bandpass. The cluster AGN fraction is 30 times greater than the 3{sigma} upper limit on the value for AGNs of similar luminosity at z {approx} 0.25, as well as more than an order of magnitude greater than the AGN fraction at z {approx} 0.75. AGNs with L{sub X,{sub H}} {>=} 10{sup 43} erg s{sup -1} exhibit similarly pronounced evolution with redshift. In contrast to the local universe, where the luminous AGN fraction is higher in the field than in clusters, the X-ray and MIR-selected AGN fractions in the field and clusters are consistent at 1 < z < 1.5. This is evidence that the cluster AGN population has evolved more rapidly than the field population from z {approx} 1.5 to the present. This environment-dependent AGN evolution mimics the more rapid evolution of star-forming galaxies in clusters relative to the field.

  11. IS THE TWO MICRON ALL SKY SURVEY CLUSTERING DIPOLE CONVERGENT?

    SciTech Connect (OSTI)

    Bilicki, Maciej; Chodorowski, Michal; Jarrett, Thomas; Mamon, Gary A.

    2011-11-01

    There is a long-standing controversy about the convergence of the dipole moment of the galaxy angular distribution (the so-called clustering dipole). Is the dipole convergent at all, and if so, what is the scale of the convergence? We study the growth of the clustering dipole of galaxies as a function of the limiting flux of the sample from the Two Micron All Sky Survey (2MASS). Contrary to some earlier claims, we find that the dipole does not converge before the completeness limit of the 2MASS Extended Source Catalog, i.e., up to 13.5 mag in the near-infrared K{sub s} band (equivalent to an effective distance of 300 Mpc h{sup -1}). We compare the observed growth of the dipole with the theoretically expected, conditional one (i.e., given the velocity of the Local Group relative to the cosmic microwave background), for the {Lambda}CDM power spectrum and cosmological parameters constrained by the Wilkinson Microwave Anisotropy Probe. The observed growth turns out to be within 1{sigma} confidence level of its theoretical counterpart once the proper observational window of the 2MASS flux-limited catalog is included. For a contrast, if the adopted window is a top hat, then the predicted dipole grows significantly faster and converges (within the errors) to its final value for a distance of about 300 Mpc h{sup -1}. By comparing the observational windows, we show that for a given flux limit and a corresponding distance limit, the 2MASS flux-weighted window passes less large-scale signal than the top-hat one. We conclude that the growth of the 2MASS dipole for effective distances greater than 200 Mpc h{sup -1} is only apparent. On the other hand, for a distance of 80 Mpc h{sup -1} (mean depth of the 2MASS Redshift Survey) and the {Lambda}CDM power spectrum, the true dipole is expected to reach only {approx}80% of its final value. Eventually, since for the window function of 2MASS the predicted growth is consistent with the observed one, we can compare the two to evaluate

  12. Microsoft Word - Ventilation System Sampling Results 1

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

    Ventilation System Sampling Results Air sampling results before and after the High Efficiency Particulate Air (HEPA) filters at WIPP are available here. Station A samples air before the filters and Station B samples air after passing through the filters. These samples were analyzed following the detection of airborne radioactivity on February 14, 2014. They are not environmental samples, and are not representative of the public or worker breathing zone air samples. They do provide assurance that

  13. Supersonic Bare Metal Cluster Beams. Technical Progress Report, March 16, 1984 - April 1, 1985

    DOE R&D Accomplishments [OSTI]

    Smalley, R. E.

    1985-01-01

    There have been four major areas of concentration for the study of bare metal cluster beams: neutral cluster, chemical reactivity, cold cluster ion source development (both positive and negative), bare cluster ion ICR (ion cyclotron resonance) development, and photofragmentation studies of bare metal cluster ions.

  14. A Distributed Flocking Approach for Information Stream Clustering Analysis

    SciTech Connect (OSTI)

    Cui, Xiaohui; Potok, Thomas E

    2006-01-01

    Intelligence analysts are currently overwhelmed with the amount of information streams generated everyday. There is a lack of comprehensive tool that can real-time analyze the information streams. Document clustering analysis plays an important role in improving the accuracy of information retrieval. However, most clustering technologies can only be applied for analyzing the static document collection because they normally require a large amount of computation resource and long time to get accurate result. It is very difficult to cluster a dynamic changed text information streams on an individual computer. Our early research has resulted in a dynamic reactive flock clustering algorithm which can continually refine the clustering result and quickly react to the change of document contents. This character makes the algorithm suitable for cluster analyzing dynamic changed document information, such as text information stream. Because of the decentralized character of this algorithm, a distributed approach is a very natural way to increase the clustering speed of the algorithm. In this paper, we present a distributed multi-agent flocking approach for the text information stream clustering and discuss the decentralized architectures and communication schemes for load balance and status information synchronization in this approach.

  15. Hierarchical clustering using correlation metric and spatial continuity constraint

    DOE Patents [OSTI]

    Stork, Christopher L.; Brewer, Luke N.

    2012-10-02

    Large data sets are analyzed by hierarchical clustering using correlation as a similarity measure. This provides results that are superior to those obtained using a Euclidean distance similarity measure. A spatial continuity constraint may be applied in hierarchical clustering analysis of images.

  16. Matlab Cluster Ensemble Toolbox v. 1.0

    Energy Science and Technology Software Center (OSTI)

    2009-04-27

    This is a Matlab toolbox for investigating the application of cluster ensembles to data classification, with the objective of improving the accuracy and/or speed of clustering. The toolbox divides the cluster ensemble problem into four areas, providing functionality for each. These include, (1) synthetic data generation, (2) clustering to generate individual data partitions and similarity matrices, (3) consensus function generation and final clustering to generate ensemble data partitioning, and (4) implementation of accuracy metrics. Withmore » regard to data generation, Gaussian data of arbitrary dimension can be generated. The kcenters algorithm can then be used to generate individual data partitions by either, (a) subsampling the data and clustering each subsample, or by (b) randomly initializing the algorithm and generating a clustering for each initialization. In either case an overall similarity matrix can be computed using a consensus function operating on the individual similarity matrices. A final clustering can be performed and performance metrics are provided for evaluation purposes.« less

  17. Silica-Supported Tantalum Clusters: Catalyst for Alkane Conversion

    SciTech Connect (OSTI)

    Nemana ,S.; Gates, B.

    2006-01-01

    Silica-supported tantalum clusters (on average, approximately tritantalum) were formed by the treatment, in either H{sub 2} or ethane, of adsorbed Ta(CH{sub 2}Ph){sub 5}; the supported catalyst is active for ethane conversion to methane and propane at 523 K, with the used catalyst containing clusters of the same average nuclearity as the precursor.

  18. The evolutionary tracks of young massive star clusters

    SciTech Connect (OSTI)

    Pfalzner, S.; Steinhausen, M.; Vincke, K.; Menten, K.; Parmentier, G.

    2014-10-20

    Stars mostly form in groups consisting of a few dozen to several ten thousand members. For 30 years, theoretical models have provided a basic concept of how such star clusters form and develop: they originate from the gas and dust of collapsing molecular clouds. The conversion from gas to stars being incomplete, the leftover gas is expelled, leading to cluster expansion and stars becoming unbound. Observationally, a direct confirmation of this process has proved elusive, which is attributed to the diversity of the properties of forming clusters. Here we take into account that the true cluster masses and sizes are masked, initially by the surface density of the background and later by the still present unbound stars. Based on the recent observational finding that in a given star-forming region the star formation efficiency depends on the local density of the gas, we use an analytical approach combined with N-body simulations to reveal evolutionary tracks for young massive clusters covering the first 10 Myr. Just like the Hertzsprung-Russell diagram is a measure for the evolution of stars, these tracks provide equivalent information for clusters. Like stars, massive clusters form and develop faster than their lower-mass counterparts, explaining why so few massive cluster progenitors are found.

  19. Licensing Guide and Sample License

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

    TEI:HNOL06Y TRANSFER WORKIN6 6ROUP Lic:en!iing Guide and Sample Lic:en!ie *~ ICan.u City Plan I OFermilab ~OAK ~RIDGE Nuioul~.<o-.,. Arg9..QDe t.AIOUTOlY SRNL .............. ~ A o LOs Alamos MATIO NA L l .U ORUORY / BROOKHAVEN NATIONAL LABORATORY :.:..,/ PRIN. C£loN PlASMA PHYSICS t ABOAATORV .:~ Ul!J Lawrence Uvermore National Laboratory Jef[;?on Lab t1NREL ~ ..................... sandia National Laboratories Laboratory or Facility Representative Email Addresses Phone # Ames Laboratory

  20. Low work function, stable compound clusters and generation process

    DOE Patents [OSTI]

    Dinh, Long N.; Balooch, Mehdi; Schildbach, Marcus A.; Hamza, Alex V.; McLean, II, William

    2000-01-01

    Low work function, stable compound clusters are generated by co-evaporation of a solid semiconductor (i.e., Si) and alkali metal (i.e., Cs) elements in an oxygen environment. The compound clusters are easily patterned during deposition on substrate surfaces using a conventional photo-resist technique. The cluster size distribution is narrow, with a peak range of angstroms to nanometers depending on the oxygen pressure and the Si source temperature. Tests have shown that compound clusters when deposited on a carbon substrate contain the desired low work function property and are stable up to 600.degree. C. Using the patterned cluster containing plate as a cathode baseplate and a faceplate covered with phosphor as an anode, one can apply a positive bias to the faceplate to easily extract electrons and obtain illumination.

  1. Structure based alignment and clustering of proteins (STRALCP)

    DOE Patents [OSTI]

    Zemla, Adam T.; Zhou, Carol E.; Smith, Jason R.; Lam, Marisa W.

    2013-06-18

    Disclosed are computational methods of clustering a set of protein structures based on local and pair-wise global similarity values. Pair-wise local and global similarity values are generated based on pair-wise structural alignments for each protein in the set of protein structures. Initially, the protein structures are clustered based on pair-wise local similarity values. The protein structures are then clustered based on pair-wise global similarity values. For each given cluster both a representative structure and spans of conserved residues are identified. The representative protein structure is used to assign newly-solved protein structures to a group. The spans are used to characterize conservation and assign a "structural footprint" to the cluster.

  2. THE MEMBERSHIP AND DISTANCE OF THE OPEN CLUSTER COLLINDER 419

    SciTech Connect (OSTI)

    Roberts, Lewis C.; Gies, Douglas R.; Parks, J. Robert; Grundstrom, Erika D.; McSwain, M. Virginia; Berger, David H.; Mason, Brian D.; Ten Brummelaar, Theo A.; Turner, Nils H. E-mail: gies@chara.gsu.ed E-mail: erika.grundstrom@vanderbilt.ed E-mail: dberger@sysplan.co E-mail: theo@chara-array.or

    2010-09-15

    The young open cluster Collinder 419 surrounds the massive O star, HD 193322, that is itself a remarkable multiple star system containing at least four components. Here we present a discussion of the cluster distance based upon new spectral classifications of the brighter members, UBV photometry, and an analysis of astrometric and photometric data from the third U. S. Naval Observatory CCD Astrograph Catalog and Two Micron All Sky Survey Catalog. We determine an average cluster reddening of E(B - V) = 0.37 {+-} 0.05 mag and a cluster distance of 741 {+-} 36 pc. The cluster probably contains some very young stars that may include a reddened M3 III star, IRAS 20161+4035.

  3. COMPARING MID-INFRARED GLOBULAR CLUSTER COLORS WITH POPULATION SYNTHESIS MODELS

    SciTech Connect (OSTI)

    Barmby, P.; Jalilian, F. F.

    2012-04-15

    Several population synthesis models now predict integrated colors of simple stellar populations in the mid-infrared bands. To date, the models have not been extensively tested in this wavelength range. In a comparison of the predictions of several recent population synthesis models, the integrated colors are found to cover approximately the same range but to disagree in detail, for example, on the effects of metallicity. To test against observational data, globular clusters (GCs) are used as the closest objects to idealized groups of stars with a single age and single metallicity. Using recent mass estimates, we have compiled a sample of massive, old GCs in M31 which contain enough stars to guard against the stochastic effects of small-number statistics, and measured their integrated colors in the Spitzer/IRAC bands. Comparison of the cluster photometry in the IRAC bands with the model predictions shows that the models reproduce the cluster colors reasonably well, except for a small (not statistically significant) offset in [4.5] - [5.8]. In this color, models without circumstellar dust emission predict bluer values than are observed. Model predictions of colors formed from the V band and the IRAC 3.6 and 4.5 {mu}m bands are redder than the observed data at high metallicities and we discuss several possible explanations. In agreement with model predictions, V - [3.6] and V - [4.5] colors are found to have metallicity sensitivity similar to or slightly better than V - K{sub s}.

  4. FLUORINE VARIATIONS IN THE GLOBULAR CLUSTER NGC 6656 (M22): IMPLICATIONS FOR INTERNAL ENRICHMENT TIMESCALES

    SciTech Connect (OSTI)

    D'Orazi, Valentina; Lucatello, Sara; Gratton, Raffaele G.; Lugaro, Maria; Angelou, George; Bragaglia, Angela; Carretta, Eugenio; Alves-Brito, Alan; Ivans, Inese I.; Masseron, Thomas; Mucciarelli, Alessio

    2013-01-20

    Observed chemical (anti)correlations in proton-capture elements among globular cluster stars are presently recognized as the signature of self-enrichment from now extinct, previous generations of stars. This defines the multiple population scenario. Since fluorine is also affected by proton captures, determining its abundance in globular clusters provides new and complementary clues regarding the nature of these previous generations and supplies strong observational constraints to the chemical enrichment timescales. In this paper, we present our results on near-infrared CRIRES spectroscopic observations of six cool giant stars in NGC 6656 (M22): the main objective is to derive the F content and its internal variation in this peculiar cluster, which exhibits significant changes in both light- and heavy-element abundances. Across our sample, we detected F variations beyond the measurement uncertainties and found that the F abundances are positively correlated with O and anticorrelated with Na, as expected according to the multiple population framework. Furthermore, our observations reveal an increase in the F content between the two different sub-groups, s-process rich and s-process poor, hosted within M22. The comparison with theoretical models suggests that asymptotic giant stars with masses between 4 and 5 M {sub Sun} are responsible for the observed chemical pattern, confirming evidence from previous works: the difference in age between the two sub-components in M22 must be not larger than a few hundred Myr.

  5. Shock waves and cosmic ray acceleration in the outskirts of galaxy clusters

    SciTech Connect (OSTI)

    Hong, Sungwook E.; Ryu, Dongsu; Kang, Hyesung; Cen, Renyue E-mail: ryu@canopus.cnu.ac.kr E-mail: cen@astro.princeton.edu

    2014-04-20

    The outskirts of galaxy clusters are continuously disturbed by mergers and gas infall along filaments, which in turn induce turbulent flow motions and shock waves. We examine the properties of shocks that form within r {sub 200} in sample galaxy clusters from structure formation simulations. While most of these shocks are weak and inefficient accelerators of cosmic rays (CRs), there are a number of strong, energetic shocks which can produce large amounts of CR protons via diffusive shock acceleration. We show that the energetic shocks reside mostly in the outskirts and a substantial fraction of them are induced by infall of the warm-hot intergalactic medium from filaments. As a result, the radial profile of the CR pressure in the intracluster medium is expected to be broad, dropping off more slowly than that of the gas pressure, and might be even temporarily inverted, peaking in the outskirts. The volume-integrated momentum spectrum of CR protons inside r {sub 200} has the power-law slope of 4.25-4.5, indicating that the average Mach number of the shocks of main CR production is in the range of {sub CR} ? 3-4. We suggest that some radio relics with relatively flat radio spectrum could be explained by primary electrons accelerated by energetic infall shocks with M{sub s} ? 3 induced in the cluster outskirts.

  6. KINEMATIC PROPERTIES AS PROBES OF THE EVOLUTION OF DWARF GALAXIES IN THE VIRGO CLUSTER

    SciTech Connect (OSTI)

    Toloba, E.; Gorgas, J.; De Paz, A. Gil; Boselli, A.; Peletier, R. F.; Yildiz, U.; Cenarro, A. J.; Gadotti, D. A.; Pedraz, S.

    2009-12-10

    We present new observational results on the kinematical, morphological, and stellar population properties of a sample of 21 dEs located both in the Virgo Cluster and in the field, which show that 52% of the dEs (1) are rotationally supported, (2) exhibit structural signs of typical rotating systems such as disks, bars, or spiral arms, (3) are younger (approx3 Gyr) than non-rotating dEs, and (4) are preferentially located either in the outskirts of Virgo or in the field. This evidence is consistent with the idea that rotationally supported dwarfs are late-type spirals or irregulars that recently entered the cluster and lost their gas through a ram pressure stripping event, quenching their star formation and becoming dEs through passive evolution. We also find that all, but one, galaxies without photometric hints for hosting disks are pressure supported and are all situated in the inner regions of the cluster. This suggests a different evolution from the rotationally supported systems. Three different scenarios for these non-rotating galaxies are discussed (in situ formation, harassment, and ram pressure stripping).

  7. THE IMACS CLUSTER BUILDING SURVEY. V. FURTHER EVIDENCE FOR STARBURST RECYCLING FROM QUANTITATIVE GALAXY MORPHOLOGIES

    SciTech Connect (OSTI)

    Abramson, Louis E.; Gladders, Michael D.; Dressler, Alan; Oemler, Augustus Jr.; Monson, Andrew; Persson, Eric; Poggianti, Bianca M.; Vulcani, Benedetta

    2013-11-10

    Using J- and K{sub s}-band imaging obtained as part of the IMACS Cluster Building Survey (ICBS), we measure Sérsic indices for 2160 field and cluster galaxies at 0.31 < z < 0.54. Using both mass- and magnitude-limited samples, we compare the distributions for spectroscopically determined passive, continuously star-forming, starburst, and post-starburst systems and show that previously established spatial and statistical connections between these types extend to their gross morphologies. Outside of cluster cores, we find close structural ties between starburst and continuously star-forming, as well as post-starburst and passive types, but not between starbursts and post-starbursts. These results independently support two conclusions presented in Paper II of this series: (1) most starbursts are the product of a non-disruptive triggering mechanism that is insensitive to global environment, such as minor mergers; (2) starbursts and post-starbursts generally represent transient phases in the lives of 'normal' star-forming and quiescent galaxies, respectively, originating from and returning to these systems in closed 'recycling' loops. In this picture, spectroscopically identified post-starbursts constitute a minority of all recently terminated starbursts, largely ruling out the typical starburst as a quenching event in all but the densest environments.

  8. Offline solid phase microextraction sampling system

    DOE Patents [OSTI]

    Harvey, Chris A.

    2008-12-16

    An offline solid phase microextraction (SPME) sampling apparatus for enabling SPME samples to be taken a number of times from a previously collected fluid sample (e.g. sample atmosphere) stored in a fused silica lined bottle which keeps volatile organics in the fluid sample stable for weeks at a time. The offline SPME sampling apparatus has a hollow body surrounding a sampling chamber, with multiple ports through which a portion of a previously collected fluid sample may be (a) released into the sampling chamber, (b) SPME sampled to collect analytes for subsequent GC analysis, and (c) flushed/purged using a fluidically connected vacuum source and purging fluid source to prepare the sampling chamber for additional SPME samplings of the same original fluid sample, such as may have been collected in situ from a headspace.

  9. PREDICTING MERGER-INDUCED GAS MOTIONS IN ?CDM GALAXY CLUSTERS

    SciTech Connect (OSTI)

    Nagai, Daisuke; Lau, Erwin T.; Avestruz, Camille; Rudd, Douglas H.; Nelson, Kaylea

    2013-11-10

    In the hierarchical structure formation model, clusters of galaxies form through a sequence of mergers and continuous mass accretion, which generate significant random gas motions especially in their outskirts where material is actively accreting. Non-thermal pressure provided by the internal gas motions affects the thermodynamic structure of the X-ray emitting intracluster plasma and introduces biases in the physical interpretation of X-ray and Sunyaev-Zeldovich effect observations. However, we know very little about the nature of gas motions in galaxy clusters. The ASTRO-H X-ray mission, scheduled to launch in 2015, will have a calorimeter capable of measuring gas motions in galaxy clusters at the level of ?< 100 km s{sup 1}. In this work, we predict the level of merger-induced gas motions expected in the ?CDM model using hydrodynamical simulations of galaxy cluster formation. We show that the gas velocity dispersion is larger in more massive clusters, but exhibits a large scatter. We show that systems with large gas motions are morphologically disturbed, while early forming, relaxed groups show a smaller level of gas motions. By analyzing mock ASTRO-H observations of simulated clusters, we show that such observations can accurately measure the gas velocity dispersion out to the outskirts of nearby relaxed galaxy clusters. ASTRO-H analysis of merging clusters, on the other hand, requires multi-component spectral fitting and enables unique studies of substructures in galaxy clusters by measuring both the peculiar velocities and the velocity dispersion of gas within individual sub-clusters.

  10. COMPLETION REPORT FOR WELL CLUSTER ER-5-3

    SciTech Connect (OSTI)

    BECHTEL NEVADA

    2005-12-01

    Well Cluster ER-5-3 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. This cluster of 3 wells was drilled in 2000 and 2001 as part of a hydrogeologic investigation program in Frenchman Flat. The first borehole in the cluster, Well ER-5-3, was drilled in February and March 2000. A 47.0-centimeter surface hole was drilled and cased off to the depth of 374.8 meters. The hole diameter was decreased to 31.1 centimeters for drilling to a total depth of 794.3 meters within welded ash-flow tuff. A piezometer string with 1 slotted interval was installed in the annulus of the surface casing, open to the saturated alluvium. A completion string with 2 slotted intervals was installed in the main hole, open to saturated alluvium and to the welded tuff aquifer. A second piezometer string with 1 slotted interval open to the welded-tuff aquifer was installed outside the completion string. Well ER-5-3 No.2 was drilled about 30 meters west of the first borehole in March 2000, and was recompleted in March 2001. A 66.0-centimeter hole was drilled and cased off to the depth of 613.8 meters. The hole diameter was decreased to 44.5 centimeters and the borehole was drilled and cased off to the depth of 849.0 meters. The hole diameter was decreased once more to 31.1 centimeters for drilling to a total depth of 1,732.2 meters in dolomite. A completion string open to the dolomite (lower carbonate aquifer) was installed. Well ER-5-3 No.3 was drilled approximately 30 meters north of the first 2 boreholes in February 2001. A 66.0-centimeter hole was drilled and cased off to the depth of 36.6 meters, then the main 25.1-centimeter-diameter hole was drilled to a total depth of 548.6 meters in alluvium. A slotted stainless-steel tubing string was installed in the saturated alluvium. A preliminary composite, static water level was measured at

  11. CFCNCA Sample Pledge Form | Department of Energy

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

    CFCNCA Sample Pledge Form CFCNCA Sample Pledge Form This file contains a sample pledge form and instructions for completing a paper donation through the CFC. CFCNCA Fall 2012 Sample Pledge Form.pdf (151.39 KB) More Documents & Publications CFCNCA Sample Pledge Form 2012 CFCNCA Catalog of Caring DOE F 3630.1 Rights and Benefits of Reservists Called to Active Duty

  12. Ionization of large homogeneous and heterogeneous clusters generated in acetylene-Ar expansions: Cluster ion polymerization

    SciTech Connect (OSTI)

    Kocisek, J.; Lengyel, J.; Farnik, M.

    2013-03-28

    Pure acetylene and mixed Ar-acetylene clusters are formed in supersonic expansions of acetylene/argon mixtures and analysed using reflectron time-of-flight mass spectrometer with variable electron energy ionization source. Acetylene clusters composed of more than a hundred acetylene molecules are generated at the acetylene concentration of Almost-Equal-To 8%, while mixed species are produced at low concentrations ( Almost-Equal-To 0.7%). The electron energy dependence of the mass spectra revealed the ionization process mechanisms in clusters. The ionization above the threshold for acetylene molecule of 11.5 eV results in the main ionic fragment progression (C{sub 2}H{sub 2}){sub n}{sup +}. At the electron energies Greater-Than-Or-Slanted-Equal-To 21.5 eV above the CH+CH{sup +} dissociative ionization limit of acetylene the fragment ions nominally labelled as (C{sub 2}H{sub 2}){sub n}CH{sup +}, n Greater-Than-Or-Slanted-Equal-To 2, are observed. For n Less-Than-Or-Slanted-Equal-To 7 these fragments correspond to covalently bound ionic structures as suggested by the observed strong dehydrogenation [(C{sub 2}H{sub 2}){sub n}-k Multiplication-Sign H]{sup +} and [(C{sub 2}H{sub 2}){sub n}CH -k Multiplication-Sign H]{sup +}. The dehydrogenation is significantly reduced in the mixed clusters where evaporation of Ar instead of hydrogen can stabilize the nascent molecular ion. The C{sub 3}H{sub 3}{sup +} ion was previously assigned to originate from the benzene molecular ion; however, the low appearance energy of Almost-Equal-To 13.7 eV indicates that a less rigid covalently bound structure of C{sub 6}H{sub 6}{sup +} ion must also be formed upon the acetylene cluster electron ionization. The appearance energy of Ar{sub n}(C{sub 2}H{sub 2}){sup +} fragments above Almost-Equal-To 15.1 eV indicates that the argon ionization is the first step in the fragment ion production, and the appearance energy of Ar{sub n{>=}2}(C{sub 2}H{sub 2}){sub m{>=}2}{sup +} at Almost-Equal-To 13

  13. Galaxy Clusters in the Swift/BAT era II: 10 more Clusters detected above 15 keV

    SciTech Connect (OSTI)

    Ajello, M.; Rebusco, P.; Cappelluti, N.; Reimer, O.; Boehringer, H.; La Parola, V.; Cusumano, G.; ,

    2010-10-27

    We report on the discovery of 10 additional galaxy clusters detected in the ongoing Swift/BAT all-sky survey. Among the newly BAT-discovered clusters there are: Bullet, Abell 85, Norma, and PKS 0745-19. Norma is the only cluster, among those presented here, which is resolved by BAT. For all the clusters we perform a detailed spectral analysis using XMM-Newton and Swift/BAT data to investigate the presence of a hard (non-thermal) X-ray excess. We find that in most cases the clusters emission in the 0.3-200 keV band can be explained by a multi-temperature thermal model confirming our previous results. For two clusters (Bullet and Abell 3667) we find evidence for the presence of a hard X-ray excess. In the case of the Bullet cluster, our analysis confirms the presence of a non-thermal, power-law like, component with a 20-100 keV flux of 3.4 x 10{sup -12} erg cm{sup -2} s{sup -1} as detected in previous studies. For Abell 3667 the excess emission can be successfully modeled as a hot component (kT = {approx}13 keV). We thus conclude that the hard X-ray emission from galaxy clusters (except the Bullet) has most likely thermal origin.

  14. Change in magnetic and structural properties of FeRh thin films by gold cluster ion beam irradiation with the energy of 1.67?MeV/atom

    SciTech Connect (OSTI)

    Koide, T.; Iwase, A. [Department of Materials Science, Osaka Prefecture University, Sakai, Osaka 599-8531 (Japan); Saitoh, Y. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Sakamaki, M.; Amemiya, K. [High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801 (Japan); Matsui, T., E-mail: t-matsui@21c.osakafu-u.ac.jp [Research Organization for the 21st Century, Osaka Prefecture University Sakai, Osaka 599-8531 (Japan)

    2014-05-07

    The effect of energetic cluster ion beam irradiation on magnetic and structural properties of FeRh thin films have been investigated. The cluster ions used in the present studies consist of a few gold atoms with the energy of 1.67?MeV/gold atom. Saturation magnetization of the sample irradiated with Au3 cluster ion beam (280?emu/cc) is larger than that for the irradiated sample with Au1 ion beam (240?emu/cc) for the same irradiation ion fluence. These results can also be confirmed by the X-ray magnetic circular dichroism (XMCD) measurement; the XMCD signal for Au3 cluster ion irradiation is larger than that for Au1 ion irradiation. Since the ion beam irradiation induced magnetization of FeRh is significantly correlated with the amount of the lattice defects in the samples, cluster ion beam irradiation can be considered to effectively introduce the lattice defects in B2-type FeRh rather than the single ion beam. Consequently, cluster ion irradiation is better than single ion irradiation for the viewpoint of saturation magnetization, even if the same irradiation energy is deposited in the samples.

  15. Photometric redshifts and clustering of emission line galaxies selected jointly by DES and eBOSS

    SciTech Connect (OSTI)

    Jouvel, S.; et al.

    2015-09-23

    We present the results of the first test plates of the extended Baryon Oscillation Spectroscopic Survey. This paper focuses on the emission line galaxies (ELG) population targetted from the Dark Energy Survey (DES) photometry. We analyse the success rate, efficiency, redshift distribution, and clustering properties of the targets. From the 9000 spectroscopic redshifts targetted, 4600 have been selected from the DES photometry. The total success rate for redshifts between 0.6 and 1.2 is 71\\% and 68\\% respectively for a bright and faint, on average more distant, samples including redshifts measured from a single strong emission line. We find a mean redshift of 0.8 and 0.87, with 15 and 13\\% of unknown redshifts respectively for the bright and faint samples. In the redshift range 0.6sample is 0.85 and 0.9 respectively. Star contamination is lower than 2\\%. We measure a galaxy bias averaged on scales of 1 and 10~Mpc/h of 1.72 \\pm 0.1 for the bright sample and of 1.78 \\pm 0.12 for the faint sample. The error on the galaxy bias have been obtained propagating the errors in the correlation function to the fitted parameters. This redshift evolution for the galaxy bias is in agreement with theoretical expectations for a galaxy population with MB-5\\log h < -21.0. We note that biasing is derived from the galaxy clustering relative to a model for the mass fluctuations. We investigate the quality of the DES photometric redshifts and find that the outlier fraction can be reduced using a comparison between template fitting and neural network, or using a random forest algorithm.

  16. WAS THE SUN BORN IN A MASSIVE CLUSTER?

    SciTech Connect (OSTI)

    Dukes, Donald; Krumholz, Mark R.

    2012-07-20

    A number of authors have argued that the Sun must have been born in a cluster of no more than several thousand stars, on the basis that, in a larger cluster, close encounters between the Sun and other stars would have truncated the outer solar system or excited the outer planets into eccentric orbits. However, this dynamical limit is in tension with meteoritic evidence that the solar system was exposed to a nearby supernova during or shortly after its formation; a several-thousand-star cluster is much too small to produce a massive star whose lifetime is short enough to have provided the enrichment. In this paper, we revisit the dynamical limit in the light of improved observations of the properties of young clusters. We use a series of scattering simulations to measure the velocity-dependent cross-section for disruption of the outer solar system by stellar encounters, and use this cross-section to compute the probability of a disruptive encounter as a function of birth cluster properties. We find that, contrary to prior work, the probability of disruption is small regardless of the cluster mass, and that it actually decreases rather than increases with cluster mass. Our results differ from prior work for three main reasons: (1) unlike in most previous work, we compute a velocity-dependent cross-section and properly integrate over the cluster mass-dependent velocity distribution of incoming stars; (2) we recognize that {approx}90% of clusters have lifetimes of a few crossing times, rather than the 10-100 Myr adopted in many earlier models; and (3) following recent observations, we adopt a mass-independent surface density for embedded clusters, rather than a mass-independent radius as assumed many earlier papers. Our results remove the tension between the dynamical limit and the meteoritic evidence, and suggest that the Sun was born in a massive cluster. A corollary to this result is that close encounters in the Sun's birth cluster are highly unlikely to truncate

  17. THE BIZARRE CHEMICAL INVENTORY OF NGC 2419, AN EXTREME OUTER HALO GLOBULAR CLUSTER

    SciTech Connect (OSTI)

    Cohen, Judith G.; Kirby, Evan N. E-mail: enk@astro.caltech.edu

    2012-11-20

    We present new Keck/HIRES observations of six red giants in the globular cluster (GC) NGC 2419. Although the cluster is among the most distant and most luminous in the Milky Way, it was considered chemically ordinary until very recently. Our previous work showed that the near-infrared Ca II triplet line strength varied more than expected for a chemically homogeneous cluster, and that at least one star had unusual abundances of Mg and K. Here, we confirm that NGC 2419 harbors a population of stars, comprising about one-third of its mass, that is depleted in Mg by a factor of eight and enhanced in K by a factor of six with respect to the Mg-normal population. Although the majority, Mg-normal population appears to have a chemical abundance pattern indistinguishable from ordinary, inner-halo GCs, the Mg-poor population exhibits dispersions of several elements. The abundances of K and Sc are strongly anti-correlated with Mg, and some other elements (Si and Ca among others) are weakly anti-correlated with Mg. These abundance patterns suggest that the different populations of NGC 2419 sample the ejecta of diverse supernovae in addition to asymptotic giant branch ejecta. However, the abundances of Fe-peak elements except Sc show no star-to-star variation. We find no nucleosynthetic source that satisfactorily explains all of the abundance variations in this cluster. Because NGC 2419 appears like no other GC, we reiterate our previous suggestion that it is not a GC at all, but rather the core of an accreted dwarf galaxy.

  18. Hanford analytical sample projections 1996 - 2000

    SciTech Connect (OSTI)

    Joyce, S.M.

    1996-02-02

    Sample projections are compiled for the Hanford site based on inputs from the major programs for the years 1996 through 2000. Sample projections are categorized by radiation level, protocol, sample matrix and Program. Analyses requirements are also presented.

  19. Sample dependence of giant magnetocaloric effect in a cluster-glass system Ho{sub 5}Pd{sub 2}

    SciTech Connect (OSTI)

    Toyoizumi, Saori Tamaki, Akira; Kitazawa, Hideaki; Mamiya, Hiroaki; Terada, Noriki; Tamura, Ryo; Dönni, Andreas; Kawamura, Yukihiko; Morita, Kengo

    2015-05-07

    In order to investigate the effect of vacancy on the magnetocaloric effect in Ho{sub 5}Pd{sub 2}, we have carried out X-ray diffraction, magnetization, and specific heat measurements in the rare-earth intermetallic compound Ho{sub 5+x}Pd{sub 2}(−0.4 ≤ x ≤ 0.4). The maximum magnetic entropy change −ΔS{sub m}{sup max}, the maximum adiabatic temperature change ΔT{sub ad}{sup max}, and the relative cooling power of Ho{sub 5+x}Pd{sub 2} take large values at x = 0−0.4 for the field change of 5 T. The paramagnetic Curie temperature θ{sub p} increases with an increase of x. This fact suggests that the enhancement of ferromagnetic coupling among the correlated spins leads to the increase of magnetocaloric effect.

  20. Heuristic-biased stochastic sampling

    SciTech Connect (OSTI)

    Bresina, J.L.

    1996-12-31

    This paper presents a search technique for scheduling problems, called Heuristic-Biased Stochastic Sampling (HBSS). The underlying assumption behind the HBSS approach is that strictly adhering to a search heuristic often does not yield the best solution and, therefore, exploration off the heuristic path can prove fruitful. Within the HBSS approach, the balance between heuristic adherence and exploration can be controlled according to the confidence one has in the heuristic. By varying this balance, encoded as a bias function, the HBSS approach encompasses a family of search algorithms of which greedy search and completely random search are extreme members. We present empirical results from an application of HBSS to the realworld problem of observation scheduling. These results show that with the proper bias function, it can be easy to outperform greedy search.

  1. Draft Sample Collection Instrument | Department of Energy

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

    Draft Sample Collection Instrument Draft Sample Collection Instrument Davis-Bacon Semi-annual Labor Compliance Report OMB Control Number 1910-New PDF icon dbacollectioninstrument...

  2. Category:Gas Sampling | Open Energy Information

    Open Energy Info (EERE)

    Technique Subcategories This category has the following 3 subcategories, out of 3 total. G Gas Flux Sampling 1 pages S Soil Gas Sampling 1 pages Surface Gas...

  3. Category:Field Sampling | Open Energy Information

    Open Energy Info (EERE)

    Technique Subcategories This category has the following 2 subcategories, out of 2 total. G + Gas Sampling (3 categories) 4 pages W + Water Sampling (2 categories) 3...

  4. Laboratory begins environmental sampling in townsite

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

    Laboratory begins environmental sampling Laboratory begins environmental sampling in townsite Environmental assessment of areas that have been or could have been affected by...

  5. Galaxy cluster lensing masses in modified lensing potentials

    SciTech Connect (OSTI)

    Barreira, Alexandre; Li, Baojiu; Jennings, Elise; Merten, Julian; King, Lindsay; Baugh, Carlton M.; Pascoli, Silvia

    2015-10-28

    In this study, we determine the concentration–mass relation of 19 X-ray selected galaxy clusters from the Cluster Lensing and Supernova Survey with Hubble survey in theories of gravity that directly modify the lensing potential. We model the clusters as Navarro–Frenk–White haloes and fit their lensing signal, in the Cubic Galileon and Nonlocal gravity models, to the lensing convergence profiles of the clusters. We discuss a number of important issues that need to be taken into account, associated with the use of non-parametric and parametric lensing methods, as well as assumptions about the background cosmology. Our results show that the concentration and mass estimates in the modified gravity models are, within the error bars, the same as in Λ cold dark matter. This result demonstrates that, for the Nonlocal model, the modifications to gravity are too weak at the cluster redshifts, and for the Galileon model, the screening mechanism is very efficient inside the cluster radius. However, at distances ~ [2–20] Mpc/h from the cluster centre, we find that the surrounding force profiles are enhanced by ~ 20–40% in the Cubic Galileon model. This has an impact on dynamical mass estimates, which means that tests of gravity based on comparisons between lensing and dynamical masses can also be applied to the Cubic Galileon model.

  6. Optimizing weak lensing mass estimates for cluster profile uncertainty

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

    Gruen, D.; Bernstein, G. M.; Lam, T. Y.; Seitz, S.

    2011-09-11

    Weak lensing measurements of cluster masses are necessary for calibrating mass-observable relations (MORs) to investigate the growth of structure and the properties of dark energy. However, the measured cluster shear signal varies at fixed mass M200m due to inherent ellipticity of background galaxies, intervening structures along the line of sight, and variations in the cluster structure due to scatter in concentrations, asphericity and substructure. We use N-body simulated halos to derive and evaluate a weak lensing circular aperture mass measurement Map that minimizes the mass estimate variance <(Map - M200m)2> in the presence of all these forms of variability. Dependingmore » on halo mass and observational conditions, the resulting mass estimator improves on Map filters optimized for circular NFW-profile clusters in the presence of uncorrelated large scale structure (LSS) about as much as the latter improve on an estimator that only minimizes the influence of shape noise. Optimizing for uncorrelated LSS while ignoring the variation of internal cluster structure puts too much weight on the profile near the cores of halos, and under some circumstances can even be worse than not accounting for LSS at all. As a result, we discuss the impact of variability in cluster structure and correlated structures on the design and performance of weak lensing surveys intended to calibrate cluster MORs.« less

  7. NEW UBVRI PHOTOMETRY OF 234 M33 STAR CLUSTERS

    SciTech Connect (OSTI)

    Ma Jun

    2013-04-15

    This is the second paper of our series. In this paper, we present UBVRI photometry for 234 star clusters in the field of M33. For most of these star clusters, there is photometry in only two bands in previous studies. The photometry of these star clusters is performed using archival images from the Local Group Galaxies Survey, which covers 0.8 deg{sup 2} along the major axis of M33. Detailed comparisons show that, in general, our photometry is consistent with previous measurements, and in particular that our photometry is in good agreement with that of Zloczewski and Kaluzny. Combined with star cluster photometry in previous studies, we present some results: none of the M33 youngest clusters ({approx}10{sup 7} yr) have masses approaching 10{sup 5} M{sub Sun }, and comparisons with models of simple stellar populations suggest a large range of ages for M33 star clusters and some as old as the Galactic globular clusters.

  8. Optimizing weak lensing mass estimates for cluster profile uncertainty

    SciTech Connect (OSTI)

    Gruen, D.; Bernstein, G. M.; Lam, T. Y.; Seitz, S.

    2011-09-11

    Weak lensing measurements of cluster masses are necessary for calibrating mass-observable relations (MORs) to investigate the growth of structure and the properties of dark energy. However, the measured cluster shear signal varies at fixed mass M200m due to inherent ellipticity of background galaxies, intervening structures along the line of sight, and variations in the cluster structure due to scatter in concentrations, asphericity and substructure. We use N-body simulated halos to derive and evaluate a weak lensing circular aperture mass measurement Map that minimizes the mass estimate variance <(Map - M200m)2> in the presence of all these forms of variability. Depending on halo mass and observational conditions, the resulting mass estimator improves on Map filters optimized for circular NFW-profile clusters in the presence of uncorrelated large scale structure (LSS) about as much as the latter improve on an estimator that only minimizes the influence of shape noise. Optimizing for uncorrelated LSS while ignoring the variation of internal cluster structure puts too much weight on the profile near the cores of halos, and under some circumstances can even be worse than not accounting for LSS at all. As a result, we discuss the impact of variability in cluster structure and correlated structures on the design and performance of weak lensing surveys intended to calibrate cluster MORs.

  9. Galaxy cluster lensing masses in modified lensing potentials

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

    Barreira, Alexandre; Li, Baojiu; Jennings, Elise; Merten, Julian; King, Lindsay; Baugh, Carlton M.; Pascoli, Silvia

    2015-10-28

    In this study, we determine the concentration–mass relation of 19 X-ray selected galaxy clusters from the Cluster Lensing and Supernova Survey with Hubble survey in theories of gravity that directly modify the lensing potential. We model the clusters as Navarro–Frenk–White haloes and fit their lensing signal, in the Cubic Galileon and Nonlocal gravity models, to the lensing convergence profiles of the clusters. We discuss a number of important issues that need to be taken into account, associated with the use of non-parametric and parametric lensing methods, as well as assumptions about the background cosmology. Our results show that the concentrationmore » and mass estimates in the modified gravity models are, within the error bars, the same as in Λ cold dark matter. This result demonstrates that, for the Nonlocal model, the modifications to gravity are too weak at the cluster redshifts, and for the Galileon model, the screening mechanism is very efficient inside the cluster radius. However, at distances ~ [2–20] Mpc/h from the cluster centre, we find that the surrounding force profiles are enhanced by ~ 20–40% in the Cubic Galileon model. This has an impact on dynamical mass estimates, which means that tests of gravity based on comparisons between lensing and dynamical masses can also be applied to the Cubic Galileon model.« less

  10. CHEMICAL ABUNDANCE EVIDENCE OF ENDURING HIGH STAR FORMATION RATES IN AN EARLY-TYPE GALAXY: HIGH [Ca/Fe] IN NGC 5128 GLOBULAR CLUSTERS

    SciTech Connect (OSTI)

    Colucci, Janet E.; Duran, Maria Fernanda; Bernstein, Rebecca A.

    2013-08-20

    We present [Fe/H], ages, and Ca abundances for an initial sample of 10 globular clusters in NGC 5128 obtained from high-resolution, high signal-to-noise ratio echelle spectra of their integrated light. All abundances and ages are obtained using our original technique for high-resolution integrated light abundance analysis of globular clusters. The clusters have a range in [Fe/H] between -1.6 and -0.2. In this sample, the average [Ca/Fe] for clusters with [Fe/H] <-0.4 is +0.37 {+-} 0.07, while the average [Ca/Fe] in our Milky Way (MW) and M31 GC samples is +0.29 {+-} 0.09 and +0.24 {+-} 0.10, respectively. This may imply a more rapid chemical enrichment history for NGC 5128 than for either the MW or M31. This sample provides the first quantitative picture of the chemical history of NGC 5128 that is directly comparable to what is available for the MW. Data presented here were obtained with the MIKE echelle spectrograph on the Magellan Clay Telescope.

  11. Cosmological simulations of isotropic conduction in galaxy clusters

    SciTech Connect (OSTI)

    Smith, Britton; O'Shea, Brian W.; Voit, G. Mark; Ventimiglia, David; Skillman, Samuel W.

    2013-12-01

    Simulations of galaxy clusters have a difficult time reproducing the radial gas-property gradients and red central galaxies observed to exist in the cores of galaxy clusters. Thermal conduction has been suggested as a mechanism that can help bring simulations of cluster cores into better alignment with observations by stabilizing the feedback processes that regulate gas cooling, but this idea has not yet been well tested with cosmological numerical simulations. Here we present cosmological simulations of 10 galaxy clusters performed with five different levels of isotropic Spitzer conduction, which alters both the cores and outskirts of clusters, though not dramatically. In the cores, conduction flattens central temperature gradients, making them nearly isothermal and slightly lowering the central density, but failing to prevent a cooling catastrophe there. Conduction has little effect on temperature gradients outside of cluster cores because outward conductive heat flow tends to inflate the outer parts of the intracluster medium (ICM), instead of raising its temperature. In general, conduction tends reduce temperature inhomogeneity in the ICM, but our simulations indicate that those homogenizing effects would be extremely difficult to observe in ?5 keV clusters. Outside the virial radius, our conduction implementation lowers the gas densities and temperatures because it reduces the Mach numbers of accretion shocks. We conclude that, despite the numerous small ways in which conduction alters the structure of galaxy clusters, none of these effects are significant enough to make the efficiency of conduction easily measurable, unless its effects are more pronounced in clusters hotter than those we have simulated.

  12. Co-evolution of galactic nuclei and globular cluster systems

    SciTech Connect (OSTI)

    Gnedin, Oleg Y.; Ostriker, Jeremiah P.; Tremaine, Scott

    2014-04-10

    We revisit the hypothesis that dense galactic nuclei are formed from inspiraling globular clusters. Recent advances in the understanding of the continuous formation of globular clusters over cosmic time and the concurrent evolution of the galaxy stellar distribution allow us to construct a simple model that matches the observed spatial and mass distributions of clusters in the Galaxy and the giant elliptical galaxy M87. In order to compare with observations, we model the effects of dynamical friction and dynamical evolution, including stellar mass loss, tidal stripping of stars, and tidal disruption of clusters by the growing galactic nucleus. We find that inspiraling globular clusters form a dense central structure, with mass and radius comparable to the typical values in observed nuclear star clusters (NSCs) in late-type and low-mass early-type galaxies. The density contrast associated with the NSC is less pronounced in giant elliptical galaxies. Our results indicate that the NSC mass as a fraction of mass of the galaxy stellar spheroid scales as M{sub NSC}/M{sub ?}?0.0025 M{sub ?,11}{sup ?0.5}. Thus disrupted globular clusters could contribute most of the mass of NSCs in galaxies with stellar mass below 10{sup 11} M {sub ?}. The inner part of the accumulated cluster may seed the growth of a central black hole via stellar dynamical core collapse, thereby relieving the problem of how to form luminous quasars at high redshift. The seed black hole may reach ?10{sup 5} M {sub ?} within ? 1 Gyr of the beginning of globular cluster formation.

  13. Apparatus for sectioning demountable semiconductor samples

    DOE Patents [OSTI]

    Sopori, Bhushan L.; Wolf, Abraham

    1984-01-01

    Apparatus for use during polishing and sectioning operations of a ribbon sample is described. The sample holder includes a cylinder having an axially extending sample cavity terminated in a first funnel-shaped opening and a second slot-like opening. A spring-loaded pressure plunger is located adjacent the second opening of the sample cavity for frictional engagement of the sample prior to introduction of a molding medium in the sample cavity. A heat softenable molding medium is inserted in the funnel-shaped opening, to surround the sample. After polishing, the heater is energized to allow draining of the molding medium from the sample cavity. During manual polishing, the second end of the sample holder is inserted in a support ring which provides mechanical support as well as alignment of the sample holder during polishing. A gauge block for measuring the protrusion of a sample beyond the second wall of the holder is also disclosed.

  14. Electrphoretic Sample Excitation Light Assembly.

    DOE Patents [OSTI]

    Li, Qingbo; Liu, Changsheng

    2002-04-02

    An automated electrophoretic system is disclosed. The system employs a capillary cartridge having a plurality of capillary tubes. The cartridge has a first array of capillary ends projecting from one side of a plate. The first array of capillary ends are spaced apart in substantially the same manner as the wells of a microtitre tray of standard size. This allows one to simultaneously perform capillary electrophoresis on samples present in each of the wells of the tray. The system includes a stacked, dual carrousel arrangement to eliminate cross-contamination resulting from reuse of the same buffer tray on consecutive executions from electrophoresis. The system also has a gel delivery module containing a gel syringe/a stepper motor or a high pressure chamber with a pump to quickly and uniformly deliver gel through the capillary tubes. The system further includes a multi-wavelength beam generator to generate a laser beam which produces a beam with a wide range of wavelengths. An off-line capillary reconditioner thoroughly cleans a capillary cartridge to enable simultaneous execution of electrophoresis with another capillary cartridge. The streamlined nature of the off-line capillary reconditioner offers the advantage of increased system throughput with a minimal increase in system cost.

  15. Phosphine-stabilised Au{sub 9} clusters interacting with titania and silica surfaces: The first evidence for the density of states signature of the support-immobilised cluster

    SciTech Connect (OSTI)

    Andersson, Gunther G. E-mail: vladimir.golovko@canterbury.ac.nz Al Qahtani, Hassan S.; Golovko, Vladimir B. E-mail: vladimir.golovko@canterbury.ac.nz; Alvino, Jason F.; Bennett, Trystan; Wrede, Oliver; Mejia, Sol M.; Metha, Gregory F. E-mail: vladimir.golovko@canterbury.ac.nz; Adnan, Rohul; Gunby, Nathaniel; Anderson, David P.

    2014-07-07

    Chemically made, atomically precise phosphine-stabilized clusters Au{sub 9}(PPh{sub 3}){sub 8}(NO{sub 3}){sub 3} were deposited on titania and silica from solutions at various concentrations and the samples heated under vacuum to remove the ligands. Metastable induced electron spectroscopy was used to determine the density of states at the surface, and X-ray photoelectron spectroscopy for analysing the composition of the surface. It was found for the Au{sub 9} cluster deposited on titania that the ligands react with the titania substrate. Based on analysis using the singular value decomposition algorithm, the series of MIE spectra can be described as a linear combination of 3 base spectra that are assigned to the spectra of the substrate, the phosphine ligands on the substrate, and the Au clusters anchored to titania after removal of the ligands. On silica, the Au clusters show significant agglomeration after heat treatment and no interaction of the ligands with the substrate can be identified.

  16. POPULATION PARAMETERS OF INTERMEDIATE-AGE STAR CLUSTERS IN THE LARGE MAGELLANIC CLOUD. III. DYNAMICAL EVIDENCE FOR A RANGE OF AGES BEING RESPONSIBLE FOR EXTENDED MAIN-SEQUENCE TURNOFFS

    SciTech Connect (OSTI)

    Goudfrooij, Paul; Kozhurina-Platais, Vera; Puzia, Thomas H.; Chandar, Rupali E-mail: verap@stsci.edu E-mail: rupali.chandar@utoledo.edu

    2011-08-10

    We present a new analysis of 11 intermediate-age (1-2 Gyr) star clusters in the Large Magellanic Cloud based on Hubble Space Telescope imaging data. Seven of the clusters feature main-sequence turnoff (MSTO) regions that are wider than can be accounted for by a simple stellar population, whereas their red giant branches (RGBs) indicate a single value of [Fe/H]. The star clusters cover a range in present-day mass from about 1 x 10{sup 4} M{sub sun} to 2 x 10{sup 5} M{sub sun}. We compare radial distributions of stars in the upper and lower parts of the MSTO region, and calculate cluster masses and escape velocities from the present time back to a cluster age of 10 Myr. Our main result is that for all clusters in our sample with estimated escape velocities v{sub esc} {approx}> 15 km s{sup -1} at an age of 10 Myr, the stars in the brightest half of the MSTO region are significantly more centrally concentrated than the stars in the faintest half and more massive RGB and asymptotic giant branch stars. This is not the case for clusters with v{sub esc} {approx}< 10 km s{sup -1} at an age of 10 Myr. We argue that the wide MSTO region of such clusters is caused mainly by a {approx}200-500 Myr range in the ages of cluster stars due to extended star formation within the cluster from material shed by first-generation stars featuring slow stellar winds. Dilution of this enriched material by accretion of ambient interstellar matter is deemed plausible if the spread of [Fe/H] in this ambient gas was very small when the second-generation stars were formed in the cluster.

  17. CLUSTERING OF OBSCURED AND UNOBSCURED QUASARS IN THE BOOeTES FIELD: PLACING RAPIDLY GROWING BLACK HOLES IN THE COSMIC WEB

    SciTech Connect (OSTI)

    Hickox, Ryan C.; Alexander, David M.; Goulding, Andrew D.; Myers, Adam D.; Brodwin, Mark; Forman, William R.; Jones, Christine; Murray, Stephen S.; Eisenstein, Daniel; Caldwell, Nelson; Brown, Michael J. I.; Cool, Richard J.; Kochanek, Christopher S.; Dey, Arjun; Jannuzi, Buell T.; Assef, Roberto J.; Eisenhardt, Peter R.; Gorjian, Varoujan; Stern, Daniel; Le Floc'h, Emeric

    2011-04-20

    We present the first measurement of the spatial clustering of mid-infrared-selected obscured and unobscured quasars, using a sample in the redshift range 0.7 < z < 1.8 selected from the 9 deg{sup 2} Booetes multiwavelength survey. Recently, the Spitzer Space Telescope and X-ray observations have revealed large populations of obscured quasars that have been inferred from models of the X-ray background and supermassive black hole evolution. To date, little is known about obscured quasar clustering, which allows us to measure the masses of their host dark matter halos and explore their role in the cosmic evolution of black holes and galaxies. In this study, we use a sample of 806 mid-infrared-selected quasars and {approx}250,000 galaxies to calculate the projected quasar-galaxy cross-correlation function w{sub p} (R). The observed clustering yields characteristic dark matter halo masses of log(M{sub halo} [h {sup -1} M{sub sun}]) = 12.7{sup +0.4}{sub -0.6} and 13.3{sup +0.3}{sub -0.4} for unobscured quasars (QSO-1s) and obscured quasars (Obs-QSOs), respectively. The results for QSO-1s are in excellent agreement with previous measurements for optically selected quasars, while we conclude that the Obs-QSOs are at least as strongly clustered as the QSO-1s. We test for the effects of photometric redshift errors on the optically faint Obs-QSOs, and find that our method yields a robust lower limit on the clustering; photo-z errors may cause us to underestimate the clustering amplitude of the Obs-QSOs by at most {approx}20%. We compare our results to previous studies, and speculate on physical implications of stronger clustering for obscured quasars.

  18. Core sampling system spare parts assessment

    SciTech Connect (OSTI)

    Walter, E.J.

    1995-04-04

    Soon, there will be 4 independent core sampling systems obtaining samples from the underground tanks. It is desirable that these systems be available for sampling during the next 2 years. This assessment was prepared to evaluate the adequacy of the spare parts identified for the core sampling system and to provide recommendations that may remediate overages or inadequacies of spare parts.

  19. Tank 12H residuals sample analysis report

    SciTech Connect (OSTI)

    Oji, L. N.; Shine, E. P.; Diprete, D. P.; Coleman, C. J.; Hay, M. S.

    2015-06-11

    The Savannah River National Laboratory (SRNL) was requested by Savannah River Remediation (SRR) to provide sample preparation and analysis of the Tank 12H final characterization samples to determine the residual tank inventory prior to grouting. Eleven Tank 12H floor and mound residual material samples and three cooling coil scrape samples were collected and delivered to SRNL between May and August of 2014.

  20. Apparatus for sectioning demountable semiconductor samples

    DOE Patents [OSTI]

    Sopori, B.L.; Wolf, A.

    1984-01-01

    Apparatus for use during polishing and sectioning operations of a ribbon sample is described. The sample holder includes a cylinder having an axially extending sample cavity terminated in a first funnel-shaped opening and a second slot-like opening. A spring-loaded pressure plunger is located adjacent the second opening of the sample cavity for frictional engagement of the sample cavity. A heat softenable molding medium is inserted in the funnel-shaped opening, to surround the sample. After polishing, the heater is energized to allow draining of the molding medium from the sample cavity. During manual polishing, the second end of the sample holder is inserted in a support ring which provides mechanical support as well as alignment of the sample holder during polishing. A gauge block for measuring the protrusion of a sample beyond the second wall of the holder is also disclosed.

  1. Sample introduction system for a flow cytometer

    DOE Patents [OSTI]

    Van den Engh, Ger

    1997-01-01

    A sample introduction system for a flow cytometer allows easy change of sample containers such as test tubes and facilitates use in high pressure environments. The sample container includes a cap having a pressure supply chamber and a sample container attachment cavity. A sample container may be automatically positioned into the attachment cavity so as to sealably engage the end of the sample container as its outer surface. This positioning may be accomplished through some sample introduction mechanism. To facilitate cleaning, HPLC tubing and fittings may be used in a manner which facilitates removing of the entire tubing from both the nozzle container and other sample container cap to permit its replacement to avoid contamination. The sample container support may include horizontal stops which loosely limit the movement of the sample container and thus avoid further stresses upon it.

  2. Sample introduction apparatus for a flow cytometer

    DOE Patents [OSTI]

    Van den Engh, Ger

    1998-01-01

    A sample introduction system for a flow cytometer allows easy change of sample containers such as test tubes and facilitates use in high pressure environments. The sample container includes a cap having a pressure supply chamber and a sample container attachment cavity. A sample container may be automatically positioned into the attachment cavity so as to sealably engage the end of the sample container as its outer surface. This positioning may be accomplished through some sample introduction mechanism. To facilitate cleaning HPLC tubing and fittings may be used in a manner which facilitates removable of the entire tubing from both the nozzle container and other sample container cap to permit its replacement to avoid contamination. The sample container support may include horizontal stops which loosely limit the movement of the sample container and thus avoid further stresses upon it.

  3. Sample introduction apparatus for a flow cytometer

    DOE Patents [OSTI]

    Van den Engh, G.

    1998-03-10

    A sample introduction system for a flow cytometer allows easy change of sample containers such as test tubes and facilitates use in high pressure environments. The sample container includes a cap having a pressure supply chamber and a sample container attachment cavity. A sample container may be automatically positioned into the attachment cavity so as to sealably engage the end of the sample container as its outer surface. This positioning may be accomplished through some sample introduction mechanism. To facilitate cleaning HPLC tubing and fittings may be used in a manner which facilitates removable of the entire tubing from both the nozzle container and other sample container cap to permit its replacement to avoid contamination. The sample container support may include horizontal stops which loosely limit the movement of the sample container and thus avoid further stresses upon it. 3 figs.

  4. Sample introduction system for a flow cytometer

    DOE Patents [OSTI]

    Engh, G. van den

    1997-02-11

    A sample introduction system for a flow cytometer allows easy change of sample containers such as test tubes and facilitates use in high pressure environments. The sample container includes a cap having a pressure supply chamber and a sample container attachment cavity. A sample container may be automatically positioned into the attachment cavity so as to sealably engage the end of the sample container as its outer surface. This positioning may be accomplished through some sample introduction mechanism. To facilitate cleaning, HPLC tubing and fittings may be used in a manner which facilitates removing of the entire tubing from both the nozzle container and other sample container cap to permit its replacement to avoid contamination. The sample container support may include horizontal stops which loosely limit the movement of the sample container and thus avoid further stresses upon it. 3 figs.

  5. System and method for merging clusters of wireless nodes in a wireless network

    DOE Patents [OSTI]

    Budampati, Ramakrishna S.; Gonia, Patrick S.; Kolavennu, Soumitri N.; Mahasenan, Arun V.

    2012-05-29

    A system includes a first cluster having multiple first wireless nodes. One first node is configured to act as a first cluster master, and other first nodes are configured to receive time synchronization information provided by the first cluster master. The system also includes a second cluster having one or more second wireless nodes. One second node is configured to act as a second cluster master, and any other second nodes configured to receive time synchronization information provided by the second cluster master. The system further includes a manager configured to merge the clusters into a combined cluster. One of the nodes is configured to act as a single cluster master for the combined cluster, and the other nodes are configured to receive time synchronization information provided by the single cluster master.

  6. {alpha}-cluster states in N{ne}Z nuclei

    SciTech Connect (OSTI)

    Goldberg, V. Z.; Rogachev, G. V.

    2012-10-20

    The importance of studies of {alpha}-Cluster structure in N{ne}Z light nuclei is discussed. Spin-parity assignments for the low-lying levels in {sup 10}C are suggested.

  7. Generation of beams of refractory-metal clusters

    SciTech Connect (OSTI)

    Wexler, S.; Riley, R.J.; Parks, E.K.; Mao, C.R.; Pobo, L.G.

    1982-01-01

    Interest in the physical and chemical properties of small metal clusters has recently stimulated the development of sources for the generation of molecular beams of metal clusters, since the collision-free environment of a beam has the advantage of permitting in-flight study of isolated species free of interference from surroundings. For example, spectroscopic studies utilizing tunable lasers may be performed in the molecular beam environment. The objectives of our research program are the elucidation of the physical and chemical properties of clusters of refractory metal atoms, in particular those of the catalytically active transition metals. For these purposes we have built and tested two sources suitable for generation of cluster beams of refractory metals, one for continuous beams and the other for pulsed beams.

  8. Construction of Heterometallic Clusters in a small peptide scaffold...

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

    Construction of Heterometallic Clusters in a small peptide scaffold as NiFe-hydrogenase ... Authors: Dutta, A., Hamilton, G. A., Hartnett, H. E., Jones, A. K. Title: Construction of ...

  9. Visual cluster analysis and pattern recognition template and methods

    DOE Patents [OSTI]

    Osbourn, Gordon Cecil; Martinez, Rubel Francisco

    1999-01-01

    A method of clustering using a novel template to define a region of influence. Using neighboring approximation methods, computation times can be significantly reduced. The template and method are applicable and improve pattern recognition techniques.

  10. Undecametallic and hexadecametallic ferric oxo–hydroxo/ethoxo pivalate clusters

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

    Baca, Svetlana G.; Speldrich, Manfred; van Leusen, Jan; Ellern, Arkady; Kögerler, Paul

    2015-03-27

    The synthesis strategies for highly condensed {Fe11} and {Fe16} pivalate clusters have been developed based on archetypal geometrically frustrated triangular {Fe3(μ3-O)} motifs that are interlinked via oxo, hydroxo, ethoxo, and carboxylate groups.

  11. Linked supramolecular building blocks for enhanced cluster formation

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

    McLellan, Ross; Palacios, Maria A.; Beavers, Christine M.; Teat, Simon J.; Piligkos, Stergios; Brechin, Euan K.; Dalgarno, Scott J.

    2015-01-09

    Methylene-bridged calix[4]arenes have emerged as extremely versatile ligand supports in the formation of new polymetallic clusters possessing fascinating magnetic properties. Metal ion binding rules established for this building block allow one to partially rationalise the complex assembly process. The ability to covalently link calix[4]arenes at the methylene bridge provides significantly improved control over the introduction of different metal centres to resulting cluster motifs. Clusters assembled from bis-calix[4]arenes and transition metal ions or 3d-4f combinations display characteristic features of the analogous calix[4]arene supported clusters, thereby demonstrating an enhanced and rational approach towards the targeted synthesis of complex and challenging structures.

  12. Linked supramolecular building blocks for enhanced cluster formation

    SciTech Connect (OSTI)

    McLellan, Ross; Palacios, Maria A.; Beavers, Christine M.; Teat, Simon J.; Piligkos, Stergios; Brechin, Euan K.; Dalgarno, Scott J.

    2015-01-09

    Methylene-bridged calix[4]arenes have emerged as extremely versatile ligand supports in the formation of new polymetallic clusters possessing fascinating magnetic properties. Metal ion binding rules established for this building block allow one to partially rationalise the complex assembly process. The ability to covalently link calix[4]arenes at the methylene bridge provides significantly improved control over the introduction of different metal centres to resulting cluster motifs. Clusters assembled from bis-calix[4]arenes and transition metal ions or 3d-4f combinations display characteristic features of the analogous calix[4]arene supported clusters, thereby demonstrating an enhanced and rational approach towards the targeted synthesis of complex and challenging structures.

  13. Visual cluster analysis and pattern recognition template and methods

    DOE Patents [OSTI]

    Osbourn, G.C.; Martinez, R.F.

    1999-05-04

    A method of clustering using a novel template to define a region of influence is disclosed. Using neighboring approximation methods, computation times can be significantly reduced. The template and method are applicable and improve pattern recognition techniques. 30 figs.

  14. Rotational and radial velocities of 1.3-2.2 M {sub ☉} red giants in open clusters

    SciTech Connect (OSTI)

    Carlberg, Joleen K.

    2014-06-01

    This study presents the rotational distribution of red giant (RG) stars in 11 old to intermediate age open clusters. The masses of these stars are all above the Kraft break, so they lose negligible amounts of their birth angular momentum (AM) during the main-sequence (MS) evolution. However, they do span a mass range with quite different AM distributions imparted during formation, with the stars less massive than ∼1.6M {sub ☉} arriving on the MS with lower rotation rates than the more massive stars. The majority of RGs in this study are slow rotators across the entire red giant branch regardless of mass, supporting the picture that intermediate-mass stars rapidly spin down when they evolve off the MS and develop convection zones capable of driving a magnetic dynamo. Nevertheless, a small fraction of RGs in open clusters show some level of enhanced rotation, and faster rotators are as common in these clusters as in the field RG population. Most of these enhanced rotators appear to be red clump stars, which is also true of the underlying stellar sample, while others are clearly RGs that are above or below the clump. In addition to rotational velocities, the radial velocities (RVs) and membership probabilities of individual stars are also presented. Cluster heliocentric RVs for NGC 6005 and Pismis 18 are reported for the first time.

  15. Probing the Unique Size-Dependent Properties of Small Au Clusters, Au Alloy Clusters, and CO Chemisorbed Au Clusters in the Gas Phase

    SciTech Connect (OSTI)

    Zhai, Hua-jin; Li, Xi; Wang, Lai S.

    2007-04-01

    When materials are reduced in size to the nanometer scale, their physical and chemical properties undergo major changes and become size-dependent, forming the foundation for nanoscience and nanotechnology. Gold nanoparticles and small gold clusters have been the focus of intensive research activities lately. The modern goldrush is largely motivated by the recent discoveries that (i) nanogold shows unexpected catalytic properties for a wide spectrum of chemical reactions [1], (ii) nanogold enables selective binding to biomolecules such as DNA and thus can serve as biosensors [2], (iii) gold has important potential applications in nanoelectronics [3,4], and (iv) gold clusters and gold-containing compounds possess unique chemical properties [5]. All these golden discoveries have made gold a surprising and rewarding subject of investigation in nanoscience and cluster science. Indeed, some of our oldest notions regarding gold, such as its inertness, are being changed dramatically by the recent findings in nanogold.

  16. NNSA Announces Procurement of Penguin Computing Clusters to Support

    National Nuclear Security Administration (NNSA)

    Stockpile Stewardship at National Labs | National Nuclear Security Administration | (NNSA) Announces Procurement of Penguin Computing Clusters to Support Stockpile Stewardship at National Labs October 20, 2015 The National Nuclear Security Administration's (NNSA's) Lawrence Livermore National Laboratory today announced the awarding of a subcontract to Penguin Computing - a leading developer of high-performance Linux cluster computing systems based in Silicon Valley - to bolster computing for

  17. Method and apparatus for the production of cluster ions

    DOE Patents [OSTI]

    Friedman, L.; Beuhler, R.J.

    A method and apparatus for the production of cluster ions, and preferably isotopic hydrogen cluster ions is disclosed. A gas, preferably comprising a carrier gas and a substrate gas, is cooled to about its boiling point and expanded through a supersonic nozzle into a region maintained at a low pressure. Means are provided for the generation of a plasma in the gas before or just as it enters the nozzle.

  18. Analysis of a Cluster Strategy for Near Term Hydrogen Infrastructure

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

    Rollout in Southern California | Department of Energy a Cluster Strategy for Near Term Hydrogen Infrastructure Rollout in Southern California Analysis of a Cluster Strategy for Near Term Hydrogen Infrastructure Rollout in Southern California Presentation at the Renewable Hydrogen Workshop, Nov. 16, 2009, in Palm Springs, CA renewable_hydrogen_workshop_nov16_nicholas.pdf (1.64 MB) More Documents & Publications Hydrogen Supply: Cost Estimate for Hydrogen Pathways-Scoping Analysis. January

  19. MPI AND OPENMP PARADIGMS ON CLUSTER OF SMP ARCHITECTURES: THE

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

    AND OPENMP PARADIGMS ON CLUSTER OF SMP ARCHITECTURES: THE VACANCY TRACKING ALGORITHM FOR MULTI-DIMENSIONAL ARRAY TRANSPOSITION YUN HE AND CHRIS H. Q. DING Abstract. We evaluate remapping multi-dimensional arrays on cluster of SMP architectures under OpenMP, MPI, and hybrid paradigms. Traditional method of multi-dimensional array transpose needs an auxiliary array of the same size and a copy back stage. We recently developed an in-place method using vacancy tracking cycles. The vacancy tracking

  20. Genomic analyses of bacterial porin-cytochrome gene clusters

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

    Shi, Liang; Fredrickson, James K.; Zachara, John M.

    2014-11-26

    In this study, the porin-cytochrome (Pcc) protein complex is responsible for trans-outer membrane electron transfer during extracellular reduction of Fe(III) by the dissimilatory metal-reducing bacterium Geobacter sulfurreducens PCA. The identified and characterized Pcc complex of G. sulfurreducens PCA consists of a porin-like outer-membrane protein, a periplasmic 8-heme c type cytochrome (c-Cyt) and an outer-membrane 12-heme c-Cyt, and the genes encoding the Pcc proteins are clustered in the same regions of genome (i.e., the pcc gene clusters) of G. sulfurreducens PCA. A survey of additionally microbial genomes has identified the pcc gene clusters in all sequenced Geobacter spp. and other bacteriamore » from six different phyla, including Anaeromyxobacter dehalogenans 2CP-1, A. dehalogenans 2CP-C, Anaeromyxobacter sp. K, Candidatus Kuenenia stuttgartiensis, Denitrovibrio acetiphilus DSM 12809, Desulfurispirillum indicum S5, Desulfurivibrio alkaliphilus AHT2, Desulfurobacterium thermolithotrophum DSM 11699, Desulfuromonas acetoxidans DSM 684, Ignavibacterium album JCM 16511, and Thermovibrio ammonificans HB-1. The numbers of genes in the pcc gene clusters vary, ranging from two to nine. Similar to the metal-reducing (Mtr) gene clusters of other Fe(III)-reducing bacteria, such as Shewanella spp., additional genes that encode putative c-Cyts with predicted cellular localizations at the cytoplasmic membrane, periplasm and outer membrane often associate with the pcc gene clusters. This suggests that the Pcc-associated c-Cyts may be part of the pathways for extracellular electron transfer reactions. The presence of pcc gene clusters in the microorganisms that do not reduce solid-phase Fe(III) and Mn(IV) oxides, such as D. alkaliphilus AHT2 and I. album JCM 16511, also suggests that some of the pcc gene clusters may be involved in extracellular electron transfer reactions with the substrates other than Fe(III) and Mn(IV) oxides.« less

  1. Aqueous sulfate separation by crystallization of sulfate–water clusters

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

    Custelcean, Radu; Williams, Neil J.; Seipp, Charles A.

    2015-08-07

    An effective approach to separating sulfates from aqueous solutions is based on the crystallization of extended [SO4(H2O) 52-]n sulfate–water clusters with a bis(guanidinium) ligand. The ligand was generated in situ by hydrazone condensation in water, thus avoiding elaborate syntheses, tedious purifications, and organic solvents. Crystallization of sulfate–water clusters represents an alternative to the now established sulfate separation strategies that involve encapsulating the “naked” anion.

  2. Method and apparatus for the production of cluster ions

    DOE Patents [OSTI]

    Friedman, Lewis; Beuhler, Robert J.

    1988-01-01

    A method and apparatus for the production of cluster ions, and preferably isotopic hydrogen cluster ions is disclosed. A gas, preferably comprising a carrier gas and a substrate gas, is cooled to about its boiling point and expanded through a supersonic nozzle into a region maintained at a low pressure. Means are provided for the generation of a plasma in the gas before or just as it enters the nozzle.

  3. Clusters of antibiotic resistance genes enriched together stay together in

    Office of Scientific and Technical Information (OSTI)

    swine agriculture (Journal Article) | SciTech Connect Clusters of antibiotic resistance genes enriched together stay together in swine agriculture Citation Details In-Document Search Title: Clusters of antibiotic resistance genes enriched together stay together in swine agriculture Antibiotic resistance is a worldwide health risk, but the influence of animal agriculture on the genetic context and enrichment of individual antibiotic resistance alleles remains unclear. Using quantitative PCR

  4. High Temperature Membrane with HUmidification-Independent Cluster Structure

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

    | Department of Energy with HUmidification-Independent Cluster Structure High Temperature Membrane with HUmidification-Independent Cluster Structure A presentation to the High Temperature Membranes Working Group meeting, May 19, 2006. lipp.pdf (132.46 KB) More Documents & Publications High Temperature Membrane Working Group New Proton Conductive Composit Materials with Co-continuous Phases Using Functionalized and Crosslinkable TFE/VDF Fluoropolymers High temperature membranes for DMFC

  5. Luminosity Function of Faint Globular Clusters in M87

    SciTech Connect (OSTI)

    Waters, Christopher Z.; Zepf, Stephen E.; Lauer, Tod R.; Baltz, Edward A.; Silk, Joseph; /Oxford U.

    2006-07-14

    We present the luminosity function to very faint magnitudes for the globular clusters in M87, based on a 30 orbit Hubble Space Telescope (HST) WFPC2 imaging program. The very deep images and corresponding improved false source rejection allow us to probe the mass function further beyond the turnover than has been done before. We compare our luminosity function to those that have been observed in the past, and confirm the similarity of the turnover luminosity between M87 and the Milky Way. We also find with high statistical significance that the M87 luminosity function is broader than that of the Milky Way. We discuss how determining the mass function of the cluster system to low masses can constrain theoretical models of the dynamical evolution of globular cluster systems. Our mass function is consistent with the dependence of mass loss on the initial cluster mass given by classical evaporation, and somewhat inconsistent with newer proposals that have a shallower mass dependence. In addition, the rate of mass loss is consistent with standard evaporation models, and not with the much higher rates proposed by some recent studies of very young cluster systems. We also find that the mass-size relation has very little slope, indicating that there is almost no increase in the size of a cluster with increasing mass.

  6. Structures of 38-atom gold-platinum nanoalloy clusters

    SciTech Connect (OSTI)

    Ong, Yee Pin; Yoon, Tiem Leong; Lim, Thong Leng

    2015-04-24

    Bimetallic nanoclusters, such as gold-platinum nanoclusters, are nanomaterials promising wide range of applications. We perform a numerical study of 38-atom gold-platinum nanoalloy clusters, Au{sub n}Pt{sub 38−n} (0 ≤ n ≤ 38), to elucidate the geometrical structures of these clusters. The lowest-energy structures of these bimetallic nanoclusters at the semi-empirical level are obtained via a global-minimum search algorithm known as parallel tempering multi-canonical basin hopping plus genetic algorithm (PTMBHGA), in which empirical Gupta many-body potential is used to describe the inter-atomic interactions among the constituent atoms. The structures of gold-platinum nanoalloy clusters are predicted to be core-shell segregated nanoclusters. Gold atoms are observed to preferentially occupy the surface of the clusters, while platinum atoms tend to occupy the core due to the slightly smaller atomic radius of platinum as compared to gold’s. The evolution of the geometrical structure of 38-atom Au-Pt clusters displays striking similarity with that of 38-atom Au-Cu nanoalloy clusters as reported in the literature.

  7. SHOCK HEATING OF THE MERGING GALAXY CLUSTER A521

    SciTech Connect (OSTI)

    Bourdin, H.; Mazzotta, P.; Markevitch, M.; Giacintucci, S.; Brunetti, G.

    2013-02-10

    A521 is an interacting galaxy cluster located at z = 0.247, hosting a low-frequency radio halo connected to an eastern radio relic. Previous Chandra observations hinted at the presence of an X-ray brightness edge at the position of the relic, which may be a shock front. We analyze a deep observation of A521 recently performed with XMM-Newton in order to probe the cluster structure up to the outermost regions covered by the radio emission. The cluster atmosphere exhibits various brightness and temperature anisotropies. In particular, two cluster cores appear to be separated by two cold fronts. We find two shock fronts, one that was suggested by Chandra and that is propagating to the east, and another to the southwestern cluster outskirt. The two main interacting clusters appear to be separated by a shock-heated region, which exhibits a spatial correlation with the radio halo. The outer edge of the radio relic coincides spatially with a shock front, suggesting that this shock is responsible for the generation of cosmic-ray electrons in the relic. The propagation direction and Mach number of the shock front derived from the gas density jump, M = 2.4 {+-} 0.2, are consistent with expectations from the radio spectral index, under the assumption of Fermi I acceleration mechanism.

  8. Electronic and magnetic properties of small rhodium clusters

    SciTech Connect (OSTI)

    Soon, Yee Yeen; Yoon, Tiem Leong; Lim, Thong Leng

    2015-04-24

    We report a theoretical study of the electronic and magnetic properties of rhodium-atomic clusters. The lowest energy structures at the semi-empirical level of rhodium clusters are first obtained from a novel global-minimum search algorithm, known as PTMBHGA, where Gupta potential is used to describe the atomic interaction among the rhodium atoms. The structures are then re-optimized at the density functional theory (DFT) level with exchange-correlation energy approximated by Perdew-Burke-Ernzerhof generalized gradient approximation. For the purpose of calculating the magnetic moment of a given cluster, we calculate the optimized structure as a function of the spin multiplicity within the DFT framework. The resultant magnetic moments with the lowest energies so obtained allow us to work out the magnetic moment as a function of cluster size. Rhodium atomic clusters are found to display a unique variation in the magnetic moment as the cluster size varies. However, Rh{sub 4} and Rh{sub 6} are found to be nonmagnetic. Electronic structures of the magnetic ground-state structures are also investigated within the DFT framework. The results are compared against those based on different theoretical approaches available in the literature.

  9. Agent-based method for distributed clustering of textual information

    DOE Patents [OSTI]

    Potok, Thomas E [Oak Ridge, TN; Reed, Joel W [Knoxville, TN; Elmore, Mark T [Oak Ridge, TN; Treadwell, Jim N [Louisville, TN

    2010-09-28

    A computer method and system for storing, retrieving and displaying information has a multiplexing agent (20) that calculates a new document vector (25) for a new document (21) to be added to the system and transmits the new document vector (25) to master cluster agents (22) and cluster agents (23) for evaluation. These agents (22, 23) perform the evaluation and return values upstream to the multiplexing agent (20) based on the similarity of the document to documents stored under their control. The multiplexing agent (20) then sends the document (21) and the document vector (25) to the master cluster agent (22), which then forwards it to a cluster agent (23) or creates a new cluster agent (23) to manage the document (21). The system also searches for stored documents according to a search query having at least one term and identifying the documents found in the search, and displays the documents in a clustering display (80) of similarity so as to indicate similarity of the documents to each other.

  10. INFRARED VIBRATIONAL PREDISSOCIATION SPECTROSCOPY OF WATER CLUSTERS BY THE CROSSED LASER MOLECULAR BEAM TECHNIQUE

    SciTech Connect (OSTI)

    Vernon, M.F.; Krajnovich, D.J.; Kwok, H.S.; Lisy, J.M.; Shen, Y.R.; Lee, Y.T.

    1981-11-01

    Water clusters formed in a molecular beam are predissociated by tunable, pulsed, infrared radiation in the frequency range 2900~3750 cm{sup -1}. The recoiling fragments are detected off axis from the molecular beam using a rotatable mass spectrometer. Arguments are presented which show that the measured frequency dependent signal at a fixed detector angle is proportional to the absorption spectrum of the clusters. It is found that the spectra of clusters containing three or more water molecules are remarkably similar to the liquid phase spectrum. Dynamical information on the predissociation process is obtained from the velocity distribution of the fragments. An upper limit to the excited vibrational state lifetime of ~1 microsecond is observed for the results reported here. The most probable dissociation process concentrates the available excess energy into the internal motions of the fragment molecules. Both the time scale and translational energy distribution are consistent with the qualitative predictions of current theoretical models for cluster predissociation. From adiabatic dissociation trajectories and Monte Carlo simulations it is seen that the strong coupling present in the water polymers probably invalidates the simpler "diatomic" picture formulations of cluster predissociation. Instead, the energy can be extensively shared among the intermolecular motions in the polymer before dissociation. Comparison between current intermolecular potentials describing liquid water and the observed frequencies is made in the normal mode approximation. The inability of any potential to predict the gross spectral features (the number of bands and their observed frequency shift from the gas phase monomer) suggests that substantial improvement in the potential energy functions are possible, but that more accurate methods of solving the vibrational wave equation are necessary before a proper explanation of the spectral fine structure is possible. The observed differences

  11. Fluid sampling system for a nuclear reactor

    DOE Patents [OSTI]

    Lau, L.K.; Alper, N.I.

    1994-11-22

    A system of extracting fluid samples, either liquid or gas, from the interior of a nuclear reactor containment utilizes a jet pump. To extract the sample fluid, a nonradioactive motive fluid is forced through the inlet and discharge ports of a jet pump located outside the containment, creating a suction that draws the sample fluid from the containment through a sample conduit connected to the pump suction port. The mixture of motive fluid and sample fluid is discharged through a return conduit to the interior of the containment. The jet pump and means for removing a portion of the sample fluid from the sample conduit can be located in a shielded sample grab station located next to the containment. A non-nuclear grade active pump can be located outside the grab sampling station and the containment to pump the nonradioactive motive fluid through the jet pump. 1 fig.

  12. Fluid sampling system for a nuclear reactor

    DOE Patents [OSTI]

    Lau, Louis K.; Alper, Naum I.

    1994-01-01

    A system of extracting fluid samples, either liquid or gas, from the interior of a nuclear reactor containment utilizes a jet pump. To extract the sample fluid, a nonradioactive motive fluid is forced through the inlet and discharge ports of a jet pump located outside the containment, creating a suction that draws the sample fluid from the containment through a sample conduit connected to the pump suction port. The mixture of motive fluid and sample fluid is discharged through a return conduit to the interior of the containment. The jet pump and means for removing a portion of the sample fluid from the sample conduit can be located in a shielded sample grab station located next to the containment. A non-nuclear grade active pump can be located outside the grab sampling station and the containment to pump the nonradioactive motive fluid through the jet pump.

  13. Method and apparatus for data sampling

    DOE Patents [OSTI]

    Odell, D.M.C.

    1994-04-19

    A method and apparatus for sampling radiation detector outputs and determining event data from the collected samples is described. The method uses high speed sampling of the detector output, the conversion of the samples to digital values, and the discrimination of the digital values so that digital values representing detected events are determined. The high speed sampling and digital conversion is performed by an A/D sampler that samples the detector output at a rate high enough to produce numerous digital samples for each detected event. The digital discrimination identifies those digital samples that are not representative of detected events. The sampling and discrimination also provides for temporary or permanent storage, either serially or in parallel, to a digital storage medium. 6 figures.

  14. Method and apparatus for data sampling

    DOE Patents [OSTI]

    Odell, Daniel M. C.

    1994-01-01

    A method and apparatus for sampling radiation detector outputs and determining event data from the collected samples. The method uses high speed sampling of the detector output, the conversion of the samples to digital values, and the discrimination of the digital values so that digital values representing detected events are determined. The high speed sampling and digital conversion is performed by an A/D sampler that samples the detector output at a rate high enough to produce numerous digital samples for each detected event. The digital discrimination identifies those digital samples that are not representative of detected events. The sampling and discrimination also provides for temporary or permanent storage, either serially or in parallel, to a digital storage medium.

  15. ABOUT THE LINEARITY OF THE COLOR-MAGNITUDE RELATION OF EARLY-TYPE GALAXIES IN THE VIRGO CLUSTER

    SciTech Connect (OSTI)

    Smith Castelli, Analia V.; Faifer, Favio R.

    2013-07-20

    We revisit the color-magnitude relation of Virgo Cluster early-type galaxies in order to explore its alleged nonlinearity. To this aim, we reanalyze the relation already published from data obtained within the ACS Virgo Cluster Survey of the Hubble Space Telescope and perform our own photometry and analysis of the images of 100 early-type galaxies observed as part of this survey. In addition, we compare our results with those reported in the literature from data of the Sloan Digital Sky Survey. We have found that when the brightest galaxies and untypical systems are excluded from the sample, a linear relation arises in agreement with what is observed in other groups and clusters. The central regions of the brightest galaxies also follow this relation. In addition, we notice that Virgo contains at least four compact elliptical galaxies besides the well-known object VCC 1297 (NGC 4486B). Their locations in the ({mu}{sub eff})-luminosity diagram define a trend different from that followed by normal early-type dwarf galaxies, setting an upper limit in effective surface brightness and a lower limit in the effective radius for their luminosities. Based on the distribution of different galaxy sub-samples in the color-magnitude and ({mu}{sub eff})-luminosity diagrams, we draw some conclusions on their formation and the history of their evolution.

  16. Post-Award Deliverables Sample (Part 2 of Sample Deliverables for Task

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

    Orders, IDIQ Attachment. J-4) | Department of Energy Award Deliverables Sample (Part 2 of Sample Deliverables for Task Orders, IDIQ Attachment. J-4) Post-Award Deliverables Sample (Part 2 of Sample Deliverables for Task Orders, IDIQ Attachment. J-4) Document offers a post-award deliverables sample for an energy savings performance contract. Download part 2 of the post-award deliverables sample document. (33.67 KB) More Documents & Publications Pre-Award Deliverables Sample (Part 1 of

  17. Effect of Graphene with Nanopores on Metal Clusters

    SciTech Connect (OSTI)

    Zhou, Hu; Chen, Xianlang; Wang, Lei; Zhong, Xing; Zhuang, Guilin; Li, Xiaonian; Mei, Donghai; Wang, Jianguo

    2015-10-07

    Porous graphene, which is a novel type of defective graphene, shows excellent potential as a support material for metal clusters. In this work, the stability and electronic structures of metal clusters (Pd, Ir, Rh) supported on pristine graphene and graphene with different sizes of nanopore were investigated by first-principle density functional theory (DFT) calculations. Thereafter, CO adsorption and oxidation reaction on the Pd-graphene system were chosen to evaluate its catalytic performance. Graphene with nanopore can strongly stabilize the metal clusters and cause a substantial downshift of the d-band center of the metal clusters, thus decreasing CO adsorption. All binding energies, d-band centers, and adsorption energies show a linear change with the size of the nanopore: a bigger size of nanopore corresponds to a stronger metal clusters bond to the graphene, lower downshift of the d-band center, and weaker CO adsorption. By using a suitable size nanopore, supported Pd clusters on the graphene will have similar CO and O2 adsorption ability, thus leading to superior CO tolerance. The DFT calculated reaction energy barriers show that graphene with nanopore is a superior catalyst for CO oxidation reaction. These properties can play an important role in instructing graphene-supported metal catalyst preparation to prevent the diffusion or agglomeration of metal clusters and enhance catalytic performance. This work was supported by National Basic Research Program of China (973Program) (2013CB733501), the National Natural Science Foundation of China (NSFC-21176221, 21136001, 21101137, 21306169, and 91334013). D. Mei acknowledges the support from the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle. Computing time was granted by the grand challenge of computational

  18. Why does LANL sample the air?

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

    Why does LANL sample the air? Why does LANL sample the air? As the most significant pathway, air is monitored to ensure that any possible release is quickly detected. Diagram of ...

  19. Sampling Report for Parent Drum S855793

    Office of Environmental Management (EM)

    L L N L - X X X X - X X X X X Sampling Report for Parent Drum S855793 UNCLASSIFIED Forensic Science Center January 6, 2015 Sampling Report for Parent Drum S855793 Lawrence ...

  20. Template:SampleTemplate | Open Energy Information

    Open Energy Info (EERE)

    is the SampleTemplate template. It is designed for use by Sample Pages. To define a test page, please use this form. Parameters Awesomeness - The numeric level of awesomeness...

  1. Principles for Sampling Airborne Radioactivity from Stacks

    SciTech Connect (OSTI)

    Glissmeyer, John A.

    2010-10-18

    This book chapter describes the special processes involved in sampling the airborne effluents from nuclear faciities. The title of the book is Radioactive Air Sampling Methods. The abstract for this chapter was cleared as PNNL-SA-45941.

  2. Why does LANL sample the air?

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

    Why does LANL sample the air? Why does LANL sample the air? As the most significant pathway, air is monitored to ensure that any possible release is quickly detected. Diagram of air quality monitors within an exhaust stack. Nuclear facilities have three additional air sampling systems. LANL samples and analyzes air to assess effects on workers, the public, animals, and plants. As the most significant pathway, air is monitored to ensure that any possible release is quickly detected. How we do it

  3. Sample holder for X-ray diffractometry

    DOE Patents [OSTI]

    Hesch, Victor L.

    1992-01-01

    A sample holder for use with X-ray diffractometers with the capability to rotate the sample, as well as to adjust the position of the sample in the x, y, and z directions. Adjustment in the x direction is accomplished through loosening set screws, moving a platform, and retightening the set screws. Motion translators are used for adjustment in the y and z directions. An electric motor rotates the sample, and receives power from the diffractometer.

  4. Water Sampling (Healy, 1970) | Open Energy Information

    Open Energy Info (EERE)

    Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Water Sampling (Healy, 1970) Exploration Activity Details Location Unspecified Exploration...

  5. Water Sampling At International Geothermal Area, Philippines...

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    Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Water Sampling At International Geothermal Area, Philippines (Wood, 2002) Exploration...

  6. Remedial investigation sampling and analysis plan for J-Field, Aberdeen Proving Ground, Maryland. Volume 1: Field Sampling Plan

    SciTech Connect (OSTI)

    Benioff, P.; Biang, R.; Dolak, D.; Dunn, C.; Martino, L.; Patton, T.; Wang, Y.; Yuen, C.

    1995-03-01

    The Environmental Management Division (EMD) of Aberdeen Proving Ground (APG), Maryland, is conducting a remedial investigation and feasibility study (RI/FS) of the J-Field area at APG pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. J-Field is within the Edgewood Area of APG in Harford County, Maryland (Figure 1. 1). Since World War II activities in the Edgewood Area have included the development, manufacture, testing, and destruction of chemical agents and munitions. These materials were destroyed at J-Field by open burning and open detonation (OB/OD). Considerable archival information about J-Field exists as a result of efforts by APG staff to characterize the hazards associated with the site. Contamination of J-Field was first detected during an environmental survey of the Edgewood Area conducted in 1977 and 1978 by the US Army Toxic and Hazardous Materials Agency (USATHAMA) (predecessor to the US Army Environmental Center [AEC]). As part of a subsequent USATHAMA -environmental survey, 11 wells were installed and sampled at J-Field. Contamination at J-Field was also detected during a munitions disposal survey conducted by Princeton Aqua Science in 1983. The Princeton Aqua Science investigation involved the installation and sampling of nine wells and the collection and analysis of surficial and deep composite soil samples. In 1986, a Resource Conservation and Recovery Act (RCRA) permit (MD3-21-002-1355) requiring a basewide RCRA Facility Assessment (RFA) and a hydrogeologic assessment of J-Field was issued by the US Environmental Protection Agency (EPA). In 1987, the US Geological Survey (USGS) began a two-phased hydrogeologic assessment in data were collected to model, groundwater flow at J-Field. Soil gas investigations were conducted, several well clusters were installed, a groundwater flow model was developed, and groundwater and surface water monitoring programs were established that continue today.

  7. Monoxides of small terbium clusters: A density functional theory investigation

    SciTech Connect (OSTI)

    Zhang, G. L.; Yuan, H. K. Chen, H.; Kuang, A. L.; Li, Y.; Wang, J. Z.; Chen, J.

    2014-12-28

    To investigate the effect of oxygen atom on the geometrical structures, electronic, and magnetic properties of small terbium clusters, we carried out the first-principles calculations on Tb{sub n}O (n = 1-14) clusters. The capping of an oxygen atom on one trigonal-facet of Tb{sub n} structures is always favored energetically, which can significantly improve the structural stability. The far-infrared vibrational spectroscopies are found to be different from those of corresponding bare clusters, providing a distinct signal to detect the characteristic structures of Tb{sub n}O clusters. The primary effect of oxygen atom on magnetic properties is to change the magnetic orderings among Tb atoms and to reduce small of local magnetic moments of the O-coordinated Tb atoms, both of which serve as the key reasons for the experimental magnetic evolution of an oscillating behavior. These calculations are consistent with, and help to account for, the experimentally observed magnetic properties of monoxide Tb{sub n}O clusters [C. N. Van Dijk et al., J. Appl. Phys. 107, 09B526 (2010)].

  8. DISRUPTION OF STAR CLUSTERS IN THE INTERACTING ANTENNAE GALAXIES

    SciTech Connect (OSTI)

    Karl, Simon J.; Naab, Thorsten; Fall, S. Michael E-mail: naab@mpa-garching.mpg.de

    2011-06-10

    We re-examine the age distribution of star clusters in the Antennae in the context of N-body+hydrodynamical simulations of these interacting galaxies. All of the simulations that account for the observed morphology and other properties of the Antennae have star formation rates that vary relatively slowly with time, by factors of only 1.3-2.5 in the past 10{sup 8} yr. In contrast, the observed age distribution of the clusters declines approximately as a power law, dN/d{tau}{proportional_to}{tau}{sup {gamma}} with {gamma} = -1.0, for ages 10{sup 6} yr {approx}< {tau} {approx}< 10{sup 9} yr. These two facts can only be reconciled if the clusters are disrupted progressively for at least {approx}10{sup 8} yr and possibly {approx}10{sup 9} yr. When we combine the simulated formation rates with a power-law model, f{sub surv}{proportional_to}{tau}{sup {delta}}, for the fraction of clusters that survive to each age {tau}, we match the observed age distribution with exponents in the range -0.9 {approx}< {delta} {approx}< -0.6 (with a slightly different {delta} for each simulation). The similarity between {delta} and {gamma} indicates that dN/d{tau} is shaped mainly by the disruption of clusters rather than variations in their formation rate. Thus, the situation in the interacting Antennae resembles that in relatively quiescent galaxies such as the Milky Way and the Magellanic Clouds.

  9. Towards a Real-Time Cluster Computing Infrastructure

    SciTech Connect (OSTI)

    Hui, Peter SY; Chikkagoudar, Satish; Chavarría-Miranda, Daniel; Johnston, Mark R.

    2011-11-01

    Real-time computing has traditionally been considered largely in the context of single-processor and embedded systems, and indeed, the terms real-time computing, embedded systems, and control systems are often mentioned in closely related contexts. However, real-time computing in the context of multinode systems, specifically high-performance, cluster-computing systems, remains relatively unexplored, largely due to the fact that until now, there has not been a need for such an environment. In this paper, we motivate the need for a cluster computing infrastructure capable of supporting computation over large datasets in real-time. Our motivating example is an analytical framework to support the next generation North American power grid, which is growing both in size and complexity. With streaming sensor data in the future power grid potentially reaching rates on the order of terabytes per day, the task of analyzing this data subject to real-time guarantees becomes a daunting task which will require the power of high-performance cluster computing capable of functioning under real-time constraints. One specific challenge that such an environment presents is the need for real-time networked communication between cluster nodes. In this paper, we discuss the need for real-time high-performance cluster computation, along with our work-in-progress towards an infrastructure which will ultimately enable such an environment.

  10. The Hyperion Project: Partnership for an Advaned Technology Cluster Testbed

    SciTech Connect (OSTI)

    Seager, M; Leininger, M

    2008-04-28

    The Hyperion project offers a unique opportunity to participate in a community-driven testing and development resource at a scale beyond what can be accomplished by one entity alone. Hyperion is a new strategic technology partnership intended to support the member-driven development and testing at scale. This partnership will allow commodity clusters to scale up to meet the growing demands of customers multi-core petascale simulation environments. Hyperion will tightly couple together the outstanding research and development capabilities of Lawrence Livermore National Laboratory with leading technology companies, including Cisco, Data Direct Networks, Dell, Intel, LSI, Mellanox, Qlogic, RedHat, SuperMicro and Sun. The end goal of this project is to revolutionize cluster computing in fundamental ways by providing the critical software and hardware components for a highly scalable simulation environment. This environment will include support for high performance networking, parallel file systems, operating system, and cluster management. This goal will be achieved by building a scalable technology cluster testbed that will be fully dedicated to the partners and provide: (1) A scalable development testing and benchmarking environment for critical enabling Linux cluster technologies; (2) An evaluation testbed for new hardware and software technologies; and (3) A vehicle for forming long term collaborations.

  11. NEW LIMITS ON GAMMA-RAY EMISSION FROM GALAXY CLUSTERS

    SciTech Connect (OSTI)

    Griffin, Rhiannon D.; Dai, Xinyu; Kochanek, Christopher S. E-mail: xdai@ou.edu

    2014-11-01

    Galaxy clusters are predicted to produce γ-rays through cosmic ray interactions and/or dark matter annihilation, potentially detectable by the Fermi Large Area Telescope (Fermi-LAT). We present a new, independent stacking analysis of Fermi-LAT photon count maps using the 78 richest nearby clusters (z < 0.12) from the Two Micron All Sky Survey cluster catalog. We obtain the lowest limit on the photon flux to date, 2.3 × 10{sup –11} photons cm{sup –2} s{sup –1} (95% confidence) per cluster in the 0.8-100 GeV band, which corresponds to a luminosity limit of 3.5 × 10{sup 44} photons s{sup –1}. We also constrain the emission limits in a range of narrower energy bands. Scaling to recent cosmic ray acceleration and γ-ray emission models, we find that cosmic rays represent a negligible contribution to the intra-cluster energy density and gas pressure.

  12. THE STRUCTURAL EVOLUTION OF FORMING AND EARLY STAGE STAR CLUSTERS

    SciTech Connect (OSTI)

    Jaehnig, Karl O.; Da Rio, Nicola; Tan, Jonathan C. E-mail: ndario@ufl.edu

    2015-01-10

    We study the degree of angular substructure in the stellar position distribution of young members of Galactic star-forming regions, looking for correlations with distance from cluster center, surface number density of stars, and local dynamical age. To this end we adopt the catalog of members in 18 young (?1-3Myr) clusters from the Massive Young Star-Forming Complex Study in Infrared and X-ray Survey and the statistical analysis of the angular dispersion parameter, ?{sub ADP,} {sub N}. We find statistically significant correlation between ?{sub ADP,} {sub N} and physical projected distance from the center of the clusters, with the centers appearing smoother than the outskirts, consistent with more rapid dynamical processing on local dynamical, free-fall or orbital timescales. Similarly, smoother distributions are seen in regions of higher surface density, or older dynamical ages. These results indicate that dynamical processing that erases substructure is already well-advanced in young, sometimes still-forming, clusters. Such observations of the dissipation of substructure have the potential to constrain theoretical models of the dynamical evolution of young and forming clusters.

  13. ASSEMBLY OF THE RED SEQUENCE IN INFRARED-SELECTED GALAXY CLUSTERS FROM THE IRAC SHALLOW CLUSTER SURVEY

    SciTech Connect (OSTI)

    Snyder, Gregory F.; Brodwin, Mark; Mancone, Conor M.; Gonzalez, Anthony H.; Zeimann, Gregory R.; Stanford, S. A.; Stern, Daniel; Eisenhardt, Peter R. M.; Brown, Michael J. I.; Dey, Arjun; Jannuzi, Buell; Perlmutter, Saul

    2012-09-10

    We present results for the assembly and star formation histories (SFHs) of massive ({approx}L*) red sequence galaxies (RSGs) in 11 spectroscopically confirmed, infrared-selected galaxy clusters at 1.0 < z < 1.5, the precursors to present-day massive clusters with M {approx} 10{sup 15} M{sub Sun }. Using rest-frame optical photometry, we investigate evolution in the color and scatter of the RSG population, comparing with models of possible SFHs. In contrast to studies of central cluster galaxies at lower redshift (z < 1), these data are clearly inconsistent with the continued evolution of stars formed and assembled primarily at a single, much earlier time. Specifically, we find that the colors of massive cluster galaxies at z Almost-Equal-To 1.5 imply that the bulk of star formation occurred at z {approx} 3, whereas by z Almost-Equal-To 1 their colors imply formation at z {approx} 2; therefore these galaxies exhibit approximately the same luminosity-weighted stellar age at 1 < z < 1.5. This likely reflects star formation that occurs over an extended period, the effects of significant progenitor bias, or both. Our results generally indicate that massive cluster galaxy populations began forming a significant mass of stars at z {approx}> 4, contained some red spheroids by z Almost-Equal-To 1.5, and were actively assembling much of their final mass during 1 < z < 2 in the form of younger stars. Qualitatively, the slopes of the cluster color-magnitude relations are consistent with no significant evolution relative to local clusters.

  14. 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.

  15. Detection of an unidentified emission line in the stacked X-ray spectrum of galaxy clusters

    SciTech Connect (OSTI)

    Bulbul, Esra; Foster, Adam; Smith, Randall K.; Randall, Scott W.; Markevitch, Maxim; Loewenstein, Michael

    2014-07-01

    We detect a weak unidentified emission line at E = (3.55-3.57) 0.03 keV in a stacked XMM-Newton spectrum of 73 galaxy clusters spanning a redshift range 0.01-0.35. When the full sample is divided into three subsamples (Perseus, Centaurus+Ophiuchus+Coma, and all others), the line is seen at >3? statistical significance in all three independent MOS spectra and the PN 'all others' spectrum. It is also detected in the Chandra spectra of the Perseus Cluster. However, it is very weak and located within 50-110 eV of several known lines. The detection is at the limit of the current instrument capabilities. We argue that there should be no atomic transitions in thermal plasma at this energy. An intriguing possibility is the decay of sterile neutrino, a long-sought dark matter particle candidate. Assuming that all dark matter is in sterile neutrinos with m{sub s} = 2E = 7.1 keV, our detection corresponds to a neutrino decay rate consistent with previous upper limits. However, based on the cluster masses and distances, the line in Perseus is much brighter than expected in this model, significantly deviating from other subsamples. This appears to be because of an anomalously bright line at E = 3.62 keV in Perseus, which could be an Ar XVII dielectronic recombination line, although its emissivity would have to be 30 times the expected value and physically difficult to understand. Another alternative is the above anomaly in the Ar line combined with the nearby 3.51 keV K line also exceeding expectation by a factor of 10-20. Confirmation with Astro-H will be critical to determine the nature of this new line.

  16. Cluster candidates around low-power radio galaxies at z ? 1-2 in cosmos

    SciTech Connect (OSTI)

    Castignani, G.; Celotti, A.; De Zotti, G.; Chiaberge, M.; Norman, C.

    2014-09-10

    We search for high-redshift (z ?1-2) galaxy clusters using low power radio galaxies (FR I) as beacons and our newly developed Poisson probability method based on photometric redshift information and galaxy number counts. We use a sample of 32 FR Is within the Cosmic Evolution Survey (COSMOS) field from the Chiaberge et al. catalog. We derive a reliable subsample of 21 bona fide low luminosity radio galaxies (LLRGs) and a subsample of 11 high luminosity radio galaxies (HLRGs), on the basis of photometric redshift information and NRAO VLA Sky Survey radio fluxes. The LLRGs are selected to have 1.4 GHz rest frame luminosities lower than the fiducial FR I/FR II divide. This also allows us to estimate the comoving space density of sources with L {sub 1.4} ? 10{sup 32.3} erg s{sup 1} Hz{sup 1} at z ? 1.1, which strengthens the case for a strong cosmological evolution of these sources. In the fields of the LLRGs and HLRGs we find evidence that 14 and 8 of them reside in rich groups or galaxy clusters, respectively. Thus, overdensities are found around ?70% of the FR Is, independently of the considered subsample. This rate is in agreement with the fraction found for low redshift FR Is and it is significantly higher than that for FR IIs at all redshifts. Although our method is primarily introduced for the COSMOS survey, it may be applied to both present and future wide field surveys such as Sloan Digital Sky Survey Stripe 82, LSST, and Euclid. Furthermore, cluster candidates found with our method are excellent targets for next generation space telescopes such as James Webb Space Telescope.

  17. Detection of Enhancement in Number Densities of Background Galaxies due to Magnification by Massive Galaxy Clusters

    SciTech Connect (OSTI)

    Chiu, I.

    2015-10-06

    We present a detection of the enhancement in the number densities of background galaxies induced from lensing magnification and use it to test the Sunyaev-Zel'dovich effect (SZE) inferred masses in a sample of 19 galaxy clusters with median redshift z?0.42 selected from the South Pole Telescope SPT-SZ survey. Two background galaxy populations are selected for this study through their photometric colours; they have median redshifts zmedian?0.9 (low-z background) and zmedian?1.8 (high-z background). Stacking these populations, we detect the magnification bias effect at 3.3? and 1.3? for the low- and high-z backgrounds, respectively. We fit NFW models simultaneously to all observed magnification bias profiles to estimate the multiplicative factor ? that describes the ratio of the weak lensing mass to the mass inferred from the SZE observable-mass relation. We further quantify systematic uncertainties in ? resulting from the photometric noise and bias, the cluster galaxy contamination and the estimations of the background properties. The resulting ? for the combined background populations with 1? uncertainties is 0.830.24(stat)0.074(sys), indicating good consistency between the lensing and the SZE-inferred masses. We also use our best-fit ? to predict the weak lensing shear profiles and compare these predictions with observations, showing agreement between the magnification and shear mass constraints. Our work demonstrates the promise of using the magnification as a complementary method to estimate cluster masses in large surveys.

  18. Star-Forming Brightest Cluster Galaxies at 0.25 < z < 1.25: A Transitioning Fuel Supply

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

    McDonald, M.; Stalder, B.; Bayliss, M.; Allen, S. W.; Applegate, D. E.; Ashby, M. L. N.; Bautz, M.; Benson, B. A.; Bleem, L. E.; Brodwin, M.; et al

    2016-01-22

    In this paper, we present a multiwavelength study of the 90 brightest cluster galaxies (BCGs) in a sample of galaxy clusters selected via the Sunyaev Zel'dovich effect by the South Pole Telescope, utilizing data from various ground- and space-based facilities. We infer the star-formation rate (SFR) for the BCG in each cluster—based on the UV and IR continuum luminosity, as well as the [O ii]λλ3726,3729 emission line luminosity in cases where spectroscopy is available—and find seven systems with SFR > 100 M⊙ yr-1. We find that the BCG SFR exceeds 10 M⊙ yr-1 in 31 of 90 (34%) cases at 0.25 < z < 1.25, compared to ~1%–5% at z ~ 0 from the literature. At z ≳ 1, this fraction increases tomore » $${92}_{-31}^{+6}$$%, implying a steady decrease in the BCG SFR over the past ~9 Gyr. At low-z, we find that the specific SFR in BCGs is declining more slowly with time than for field or cluster galaxies, which is most likely due to the replenishing fuel from the cooling ICM in relaxed, cool core clusters. At z ≳ 0.6, the correlation between the cluster central entropy and BCG star formation—which is well established at z ~ 0—is not present. Instead, we find that the most star-forming BCGs at high-z are found in the cores of dynamically unrelaxed clusters. We use data from the Hubble Space Telescope to investigate the rest-frame near-UV morphology of a subsample of the most star-forming BCGs, and find complex, highly asymmetric UV morphologies on scales as large as ~50–60 kpc. Finally, the high fraction of star-forming BCGs hosted in unrelaxed, non-cool core clusters at early times suggests that the dominant mode of fueling star formation in BCGs may have recently transitioned from galaxy–galaxy interactions to ICM cooling.« less

  19. A CENSUS OF MID-INFRARED-SELECTED ACTIVE GALACTIC NUCLEI IN MASSIVE GALAXY CLUSTERS AT 0 {approx}< z {approx}< 1.3

    SciTech Connect (OSTI)

    Tomczak, Adam R.; Tran, Kim-Vy H.; Saintonge, Amelie

    2011-09-01

    We conduct a deep mid-infrared (mid-IR) census of nine massive galaxy clusters at (0 < z < 1.3) with a total of {approx}1500 spectroscopically confirmed member galaxies using Spitzer/IRAC photometry and established mid-IR color selection techniques. Of the 949 cluster galaxies that are detected in at least three of the four IRAC channels at the {>=}3{sigma} level, we identify 12 that host mid-IR-selected active galactic nuclei (IR-AGNs). To compare the IR-AGNs across our redshift range, we define two complete samples of cluster galaxies: (1) optically selected members with rest-frame V{sub AB} magnitude < - 21.5 and (2) mid-IR-selected members brighter than (M*{sub 3.6} + 0.5), i.e., essentially a stellar mass cut. In both samples, we measure f{sub IR-AGN} {approx} 1% with a strong upper limit of {approx}3% at z < 1. This uniformly low IR-AGN fraction at z < 1 is surprising given that the fraction of 24 {mu}m sources in the same galaxy clusters is observed to increase by about a factor of four from z {approx} 0 to z {approx} 1; this indicates that most of the detected 24 {mu}m flux is due to star formation. Only in our single galaxy cluster at z = 1.24 is the IR-AGN fraction measurably higher at {approx}15% (all members; {approx}70% for late-types only). In agreement with recent studies, we find that the cluster IR-AGNs are predominantly hosted by late-type galaxies with blue optical colors, i.e., members with recent/ongoing star formation. The four brightest IR-AGNs are also X-ray sources; these IR+X-ray AGNs all lie outside the cluster core (R{sub proj} {approx}> 0.5 Mpc) and are hosted by highly morphologically disturbed members. Although our sample is limited, our results suggest that f{sub IR-AGN} in massive galaxy clusters is not strongly correlated with star formation at z < 1 and that IR-AGNs have a more prominent role at z {approx}> 1.

  20. 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.