Sample records for activity population density

  1. Population density of San Joaquin kit fox

    SciTech Connect (OSTI)

    McCue, P.; O'Farrell, T.P.; Kato, T.; Evans, B.G.

    1982-01-01T23:59:59.000Z

    Populations of the endangered San Joaquin kit fox, vulpes macrotis mutica, are known to occur on the Elk Hills Naval Petroleum Reserve No. 1. This study assess the impact of intensified petroleum exploration and production and associated human activities on kit fox population density. (ACR)

  2. How are mortality rates affected by population density?

    E-Print Network [OSTI]

    Wang, Lei; Di, Zengru; Roehner, Bertrand M

    2013-01-01T23:59:59.000Z

    Biologists have found that the death rate of cells in culture depends upon their spatial density. Permanent "Stay alive" signals from their neighbours seem to prevent them from dying. In a previous paper (Wang et al. 2013) we gave evidence for a density effect for ants. In this paper we examine whether there is a similar effect in human demography. We find that although there is no observable relationship between population density and overall death rates, there is a clear relationship between density and the death rates of young age-groups. Basically their death rates decrease with increasing density. However, this relationship breaks down around 300 inhabitants per square kilometre. Above this threshold the death rates remains fairly constant. The same density effect is observed in Canada, France, Japan and the United States. We also observe a striking parallel between the density effect and the so-called marital status effect in the sense that they both lead to higher suicide rates and are both enhanced fo...

  3. Estimating low-density snowshoe hare populations using fecal pellet counts

    E-Print Network [OSTI]

    Estimating low-density snowshoe hare populations using fecal pellet counts Dennis L. Murray, James americanus) populations found at high densities can be estimated using fecal pellet densities on rectangular of fecal pellet plots for estimating hare populations by correlating pellet densities with estimated hare

  4. Density Functional Theory Study of Oxygen Reduction Activity...

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

    Density Functional Theory Study of Oxygen Reduction Activity on Ultrathin Platinum Nanotubes. Density Functional Theory Study of Oxygen Reduction Activity on Ultrathin Platinum...

  5. active microbial populations: Topics by E-print Network

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

    of enzyme activity Paris-Sud XI, Universit de 2 MICROBIAL POPULATIONS FECAL PELLETS AND Geosciences Websites Summary: MICROBIAL POPULATIONS FECAL PELLETS AND AND...

  6. Analysis of high-density SNP data from complex populations 

    E-Print Network [OSTI]

    Floyd, James A.B.

    2011-06-27T23:59:59.000Z

    Data from a Croatian isolate population are analysed in a genome-wide association study (GWAS) for a variety of disease-related quantitative traits. A novel genomewide approach to analysing pedigree-based association ...

  7. Population Ecology at the Range Edge Survival and Dispersal of a High-Density Lepidopteran

    E-Print Network [OSTI]

    Population Ecology at the Range Edge Survival and Dispersal of a High-Density Lepidopteran Population Cecilia Ronnås Faculty of Natural Resources and Agricultural Sciences Department of Ecology Service/Repro, Uppsala 2011 #12;Population Ecology at the Range Edge. Survival and Dispersal of a High

  8. activity mammographic density: Topics by E-print Network

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

    Circuits Engineering Websites Summary: Transition Density, A New Measure of Activity in Digital Circuits Farid N. Najm Semiconductor Process & Design Center Texas Instruments...

  9. Transition Density, A Stochastic Measure of Activity in Digital Circuits

    E-Print Network [OSTI]

    Najm, Farid N.

    Transition Density, A Stochastic Measure of Activity in Digital Circuits Farid N. Najm.e., the rate at which its nodes are switching. We propose a new measure of activity, called the transition model of logic signals, we rigorously define the transition density and present an algorithm

  10. Transition Density, A Stochastic Measure of Activity in Digital Circuits

    E-Print Network [OSTI]

    Najm, Farid N.

    Transition Density, A Stochastic Measure of Activity in Digital Circuits Farid N. Najm.e., the rate at which its nodes are switching. We propose a new measure of activity, called the transition of logic signals, we rigorously de ne the transition density and present an algorithm to propagate it from

  11. Fact #661: February 7, 2011 Population Density | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport in RepresentativeDepartment of EnergyEnergyWesternof Energyof1:

  12. Estimating snowshoe hare population density from pellet plots: a further evaluation

    E-Print Network [OSTI]

    Krebs, Charles J.

    Estimating snowshoe hare population density from pellet plots: a further evaluation Charles J fecal pellets of snowshoe hares (Lepus americanus) once a year in 10 areas in the southwestern Yukon from 1987 to 1996. Pellets in eighty 0.155-m2 quadrats were counted and cleared each June on all areas

  13. Estimating electric current densities in solar active regions

    E-Print Network [OSTI]

    Wheatland, M S

    2015-01-01T23:59:59.000Z

    Electric currents in solar active regions are thought to provide the energy released via magnetic reconnection in solar flares. Vertical electric current densities $J_z$ at the photosphere may be estimated from vector magnetogram data, subject to substantial uncertainties. The values provide boundary conditions for nonlinear force- free modelling of active region magnetic fields. A method is presented for estimating values of $J_z$ taking into account uncertainties in vector magnetogram field values, and minimizing $J_z^2$ across the active region. The method is demonstrated using the boundary values of the field for a force-free twisted bipole, with the addition of noise at randomly chosen locations.

  14. Pattern Formation in Populations with Density-Dependent Movement and Two Interaction Scales

    E-Print Network [OSTI]

    Martínez-García, Ricardo; Hernández-García, Emilio; López, Cristóbal

    2015-01-01T23:59:59.000Z

    We study the spatial patterns formed by a system of interacting particles where the mobility of any individual is determined by the population crowding at two different spatial scales. In this way we model the behavior of some biological organisms (like mussels) that tend to cluster at short ranges as a defensive strategy, and strongly disperse if there is a high population pressure at large ranges for optimizing foraging. We perform stochastic simulations of a particle-level model of the system, and derive and analyze a continuous density description (a nonlinear diffusion equation). In both cases we show that this interplay of scale-dependent-behaviors gives rise to a rich formation of spatial patterns ranging from labyrinths to periodic cluster arrangements. In most cases these clusters have the very peculiar appearance of ring-like structures, i.e., organisms arranging in the perimeter of the clusters, that we discuss in detail.

  15. Effects of population density on estrous cycles of two-year old quarter horse mares

    E-Print Network [OSTI]

    Burke, Daniel John

    1978-01-01T23:59:59.000Z

    0. 8 O u) 06 IZ I- UJ o 04 D' C( D M O D- ? O CONTROL PEN UJ X 0. 0 2/21- 3/13- 4/2- 4/22- 5/1 2-, 6/2- 3/1 2 4/1 4/21 5/1 1 6/1 6/20 TIME PERIOD COMPRISED OF COMPARABLE CYCLES Figure 4. Seasonal effects of heat intensity. 30...EFFECTS OF POPULATION DENSITY ON ESTROUS CYCLES OF TWO-YEAR OLD QUARTER HORSE MARES A Thesis by DANIEL JOHN BURKE Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER...

  16. Central stellar populations of early-type galaxies in low-density environments

    E-Print Network [OSTI]

    M. Collobert; M. Sarzi; R. L. Davies; H. Kuntschner; Matthew Colless

    2006-05-24T23:59:59.000Z

    We have investigated the properties of a volume and magnitude limited sample of nearby early type galaxies that were carefully selected from the AAO two degree field galaxy redshift survey. We used images from the DSS to confirm the E/S0 morphologies, and augmented this sample with field galaxies from Colbert et al. 2001. We present spectroscopic observations of 22 galaxies from the combined sample, from which central velocity dispersions and the Lick stellar population indices were measured. After carefully correcting the spectra for nebular emission we derived luminosity-weighted ages, metallicities, and alpha-element abundance ratios. We compare these isolated galaxies with samples of early-type galaxies in the Virgo and Coma clusters, and also with the sample of galaxies in low-density regions of Kuntschner et al. (2002). We find that galaxies in low-density environments are younger and have a greater spread of ages compared to cluster galaxies. They also show a wider range of metallicities at a given velocity dispersion than cluster galaxies, which display only super-solar metallicities. On average cluster, as well as, isolated galaxies show non-solar abundance ratios in alpha-elements, suggesting that, independent of galactic environment, star formation occurred on short time-scales. We reason that early-type galaxies in low-density environments experienced merging-induced star-formation episodes over a longer and more recent period of time compared to a cluster environment, and speculate that a considerable fraction of their stars formed out of low-metallicity halo gaseous material during the slow growth of a stellar disk between merging events.

  17. The influence of habitat selection and density on the population dynamics of stony coral species of the

    E-Print Network [OSTI]

    Sealey, Kathleen Sullivan

    The influence of habitat selection and density on the population dynamics of stony coral species of Biology, University of Miami, Coral Gables, FL, 33124 USA *Corresponding author: K. Semon Phone: 1-305-284-3013, Fax: 1-305-284-3039, e-mail: ksemon@bio.miami.edu Abstract Although stony corals are most frequently

  18. Dynamics of coastal cod populations: intra-and intercohort density dependence

    E-Print Network [OSTI]

    -temporal patterns in the abundance of cod along the Norwegian Skagerrak coast and demonstrated signi¢cant cyclicity populations (Gadus morhua L.) on the basis of the long-term monitoring data from the Norwegian Skagerrak coast

  19. Genetic variation of packing density within a selected population of Loblolly Pine (Pinus taeda L.

    E-Print Network [OSTI]

    Boyd, Lamar

    1967-01-01T23:59:59.000Z

    . Specific gravity of cell wall material Factors affecting the specific gravity of cell wall material Importance of the specific gravity of cell wall material Recent investigations concerning packing density 12 Chapter IV. Experimental des ign 13... Discussion of materials 13 Sample size 14 Chapter V. Method used for determining packing density in small wood samples 15 Definition and calculation 15 Measurement of specific gravity Measurement of cell wall material 15 17 Summary of overall...

  20. Biomarker monitoring of a population residing near uranium mining activities

    SciTech Connect (OSTI)

    Au, W.W.; Legator, M.S.; Whorton, E.B.; Wilkinson, G.S.; Gabehart, G.J.; Lane, R.G. [Univ. of Texas Medical Branch, Galveston, TX (United States)

    1995-05-01T23:59:59.000Z

    We investigated whether residents residing near uranium mining operations (target population), who are potentially exposed to toxicants from mining waste, have increased genotoxic effects compared with people residing elsewhere (reference population). Population surveys were conducted, and 24 target and 24 reference residents were selected. The selected subjects and controls were matched on age and gender and they were nonsmokers. Blood samples were collected for laboratory studies. The standard cytogenetic assay was used to determine chromosome aberration frequencies, and the challenge assay was used to investigate DNA repair responses. We found that individuals who resided near uranium mining operations had a higher mean frequency of cells with chromosome aberrations and higher deletion frequency but lower dicentric frequency than the reference group, although the difference was not statistically significant. After cells were challenged by exposure to {gamma}-rays, the target population had a significantly higher frequency of cells with chromosome aberrations and deletion frequency than the reference group. The latter observation is indicative of abnormal DNA repair response in the target population. 22 refs., 3 tabs.

  1. Density structure of an active region and associated moss using Hinode/EIS

    E-Print Network [OSTI]

    D. Tripathi; H. E. Mason; P. R. Young; G. Del Zanna

    2008-02-22T23:59:59.000Z

    Context: Studying the problem of active region heating requires precise measurements of physical plasma parameters such as electron density, temperature etc. It is also important to understand the relationship of coronal structures with the magnetic field. The Extreme-ultraviolet Imaging Spectrometer (EIS) aboard Hinode provides a rare opportunity to derive electron density simultaneously at different temperatures. Aims: MethodsWe study the density structure and characterise plasma in active regions and associated moss regions. In addition we study its relationship to the photospheric magnetic field. Methods: We used data recorded by the EIS, together with magnetic field measurements from the Michelson Doppler Imager (MDI) aboard SoHO and images recorded with the Transition Region And Coronal Explorer (TRACE) and X-Ray Telescope (XRT/Hinode). Results: We find that the hot core of the active region is densest with values as high as 10^10.5 cm^-3. The electron density estimated in specific regions in the active region moss decreases with increasing temperature. The moss areas were located primarily on one side of the active region, and they map the positive polarity regions almost exactly. The density within the moss region was highest at log T=5.8-6.1, with a value around 10^(10.0-10.5) cm^-3. The moss densities were highest in the strong positive magnetic field region. However, there was no such correlation for the negative polarity areas, where there was a large sunspot.

  2. relatively high population density (much of it living inland) and small

    E-Print Network [OSTI]

    Darton, Richard

    important method of treating wastewater from our major towns and cities is the activated sludge (AS) process are suspended. In a subsequent settling tank most of the bacterial sludge is removed and recycled to the AS tank. For example small amounts of natural and synthetic steroid oestrogen hormones, such as ethinyloestradiol (EE2

  3. Topological Structure of Population Activity in Primary Visual Gurjeet Singh, Facundo Memoli, Tigran Ishkhanov,

    E-Print Network [OSTI]

    Stanford University

    sensitive dyes (Grinvald and Hildesheim, 2004), appears to switch dynamically among states, some of them to study the topological structure of neural activity in cell populations of primary visual cortex

  4. Sociological adaptation among bacterial populations in an activated sludge ecosystem

    E-Print Network [OSTI]

    Forrest, Robert George

    1970-01-01T23:59:59.000Z

    Bacillus Corynebacterium, and Micrococcus being much less abundant. Unz and Dondero (70) isolated two-hundred and three strains from fifty-one trickling filters and activated sludge zoogloeas, with one-hundred and forty-seven of the strains forming... in the aeration basin or secondary sedimentation biomass; instead, members of the Flavobacterium C'~oh~as group, the genus Achromobacter, and a Pseudomonas-l&e group were most numerous. METHODS AND MATERIALS Batch fermentation s stem. The bench scale batch...

  5. Heavy-duty truck population, activity and usage patterns. Final report

    SciTech Connect (OSTI)

    Fischer, M.

    1998-07-01T23:59:59.000Z

    The objective of the study was to update the heavy-duty truck (HDT) population, activity (e.g., vehicle miles traveled (VMT), numbers of starts and trips, trip duration, etc.), and usage patterns type of service/business (e.g., delivery, construction, etc.), area of operation (i.e., local, short-haul, long-haul) for HDT`s registered and/or operated in California. The population and activity estimates were done on a weight-class-specific basis light-heavy-duty, medium-heavy-duty and heavy-heavy-duty. Population, activity and usage estimates were based primarily on Department of Motor Vehicles (DMV) registration data and Truck Inventory and Usage Survey (TIUS) data. In addition to the analysis of existing data (i.e., DMV and TIUS), 42 HDTs were fitted with on-board data loggers that recorded numbers of trips and starts, daily VMT and travel by time-of-day.

  6. Critical Fields, Thermally Activated Transport, and Critical Current Density of Beta-FeSe Single Crystals

    SciTech Connect (OSTI)

    Petrovic, C.; Lei, H.; Hu, R.

    2011-07-27T23:59:59.000Z

    We present critical fields, thermally activated flux flow (TAFF), and critical current density of tetragonal phase {beta}-FeSe single crystals. The upper critical fields H{sub c2}(T) for H {parallel} (101) and H {perpendicular} (101) are nearly isotropic and are likely governed by the Pauli limiting process. The large Ginzburg-Landau parameter {Kappa} {approx} 72.3(2) indicates that {beta}-FeSe is a type-II superconductor with a smaller penetration depth than in Fe(Te, Se). The resistivity below T{sub c} follows Arrhenius TAFF behavior. For both field directions below 30 kOe, single-vortex pinning is dominant, whereas collective creep becomes important above 30 kOe. The critical current density J{sub c} from M-H loops for H {parallel} (101) is about five times larger than for H {perpendicular} (101), yet much smaller than in other iron-based superconductors.

  7. An Active Instance-based Machine Learning method for Stellar Population Studies

    E-Print Network [OSTI]

    Solorio, T; Terlevich, R J; Terlevich, E; Solorio, Thamar; Fuentes, Olac; Terlevich, Roberto; Terlevich, Elena

    2005-01-01T23:59:59.000Z

    We have developed a method for fast and accurate stellar population parameters determination in order to apply it to high resolution galaxy spectra. The method is based on an optimization technique that combines active learning with an instance-based machine learning algorithm. We tested the method with the retrieval of the star-formation history and dust content in "synthetic" galaxies with a wide range of S/N ratios. The "synthetic" galaxies where constructed using two different grids of high resolution theoretical population synthesis models. The results of our controlled experiment shows that our method can estimate with good speed and accuracy the parameters of the stellar populations that make up the galaxy even for very low S/N input. For a spectrum with S/N=5 the typical average deviation between the input and fitted spectrum is less than 10**{-5}. Additional improvements are achieved using prior knowledge.

  8. An Active Instance-based Machine Learning method for Stellar Population Studies

    E-Print Network [OSTI]

    Thamar Solorio; Olac Fuentes; Roberto Terlevich; Elena Terlevich

    2005-07-22T23:59:59.000Z

    We have developed a method for fast and accurate stellar population parameters determination in order to apply it to high resolution galaxy spectra. The method is based on an optimization technique that combines active learning with an instance-based machine learning algorithm. We tested the method with the retrieval of the star-formation history and dust content in "synthetic" galaxies with a wide range of S/N ratios. The "synthetic" galaxies where constructed using two different grids of high resolution theoretical population synthesis models. The results of our controlled experiment shows that our method can estimate with good speed and accuracy the parameters of the stellar populations that make up the galaxy even for very low S/N input. For a spectrum with S/N=5 the typical average deviation between the input and fitted spectrum is less than 10**{-5}. Additional improvements are achieved using prior knowledge.

  9. A density functional theory model of mechanically activated silyl ester hydrolysis

    SciTech Connect (OSTI)

    Pill, Michael F.; Schmidt, Sebastian W. [Department of Applied Sciences and Mechatronics, Munich University of Applied Sciences, Lothstr. 34, 80335 Munich (Germany) [Department of Applied Sciences and Mechatronics, Munich University of Applied Sciences, Lothstr. 34, 80335 Munich (Germany); Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel, Olshausenstraße 40, 24098 Kiel (Germany); Center for Nanoscience (CeNS), Geschwister-Scholl-Platz 1, 80539 Munich (Germany); Beyer, Martin K. [Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel, Olshausenstraße 40, 24098 Kiel (Germany) [Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel, Olshausenstraße 40, 24098 Kiel (Germany); Institut für Ionenphysik und Angewandte Physik, Leopold-Franzens-Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck (Austria); Clausen-Schaumann, Hauke [Department of Applied Sciences and Mechatronics, Munich University of Applied Sciences, Lothstr. 34, 80335 Munich (Germany) [Department of Applied Sciences and Mechatronics, Munich University of Applied Sciences, Lothstr. 34, 80335 Munich (Germany); Center for Nanoscience (CeNS), Geschwister-Scholl-Platz 1, 80539 Munich (Germany); Kersch, Alfred, E-mail: akersch@hm.edu [Department of Applied Sciences and Mechatronics, Munich University of Applied Sciences, Lothstr. 34, 80335 Munich (Germany)] [Department of Applied Sciences and Mechatronics, Munich University of Applied Sciences, Lothstr. 34, 80335 Munich (Germany)

    2014-01-28T23:59:59.000Z

    To elucidate the mechanism of the mechanically activated dissociation of chemical bonds between carboxymethylated amylose (CMA) and silane functionalized silicon dioxide, we have investigated the dissociation kinetics of the bonds connecting CMA to silicon oxide surfaces with density functional calculations including the effects of force, solvent polarizability, and pH. We have determined the activation energies, the pre-exponential factors, and the reaction rate constants of candidate reactions. The weakest bond was found to be the silyl ester bond between the silicon and the alkoxy oxygen atom. Under acidic conditions, spontaneous proton addition occurs close to the silyl ester such that neutral reactions become insignificant. Upon proton addition at the most favored position, the activation energy for bond hydrolysis becomes 31 kJ?mol{sup ?1}, which agrees very well with experimental observation. Heterolytic bond scission in the protonated molecule has a much higher activation energy. The experimentally observed bi-exponential rupture kinetics can be explained by different side groups attached to the silicon atom of the silyl ester. The fact that different side groups lead to different dissociation kinetics provides an opportunity to deliberately modify and tune the kinetic parameters of mechanically activated bond dissociation of silyl esters.

  10. High-capacity electric double-layer capacitor with high-density-activated carbon fiber electrodes

    SciTech Connect (OSTI)

    Nakagawa, Hiroyuki; Shudo, Atsushi; Miura, Kouichi

    2000-01-01T23:59:59.000Z

    Recently the authors have presented a method to prepare activated carbon fiber with high bulk density (HD-ACF) without using any binders. The possibility of using the HD-ACF as an electrode for electric double-layer capacitors (EDLCs) was examined in this paper. The capacitance of the EDLC with the HD-ACF electrode increased with the increase of bulk density of the HD-ACF, indicating that individual fibers are highly packed without losing their capacitance. The capacitance also increased in proportion to the size of the HD-ACF electrode. The initial discharge current of the EDLC showed little dependency on either the bulk density or the size of the HD-ACF electrode. These results clarified that the HD-ACF electrode is suitable for constructing a high-power EDLC. The initial discharge current was directly proportional to the conductivity of aqueous KCI used as the electrolyte, indicating that the resistance of the electrolyte is much higher than that of the HD-ACF electrode. This result showed that the efficiency of the HD-ACF was well above the efficiency of the electrolyte used in this study and that the improvement of the ionic conductivity of electrolyte is also necessary for developing a high-power EDLC.

  11. Travel determinants and multi-scale transferability of national activity patterns to local populations

    SciTech Connect (OSTI)

    Henson, Kriste M [Los Alamos National Laboratory; Gou; ias, Konstadinos G [UCSB

    2010-11-30T23:59:59.000Z

    The ability to transfer national travel patterns to a local population is of interest when attempting to model megaregions or areas that exceed metropolitan planning organization (MPO) boundaries. At the core of this research are questions about the connection between travel behavior and land use, urban form, and accessibility. As a part of this process, a group of land use variables have been identified to define activity and travel patterns for individuals and households. The 2001 National Household Travel Survey (NHTS) participants are divided into categories comprised of a set of latent cluster models representing persons, travel, and land use. These are compared to two sets of cluster models constructed for two local travel surveys. Comparison of means statistical tests are used to assess differences among sociodemographic groups residing in localities with similar land uses. The results show that the NHTS and the local surveys share mean population activity and travel characteristics. However, these similarities mask behavioral heterogeneity that are shown when distributions of activity and travel behavior are examined. Therefore, data from a national household travel survey cannot be used to model local population travel characteristics if the goal to model the actual distributions and not mean travel behavior characteristics.

  12. Age determination of the nuclear stellar population of Active Galactic Nuclei using Locally Weighted Regression

    E-Print Network [OSTI]

    Trilce Estrada-Piedra; Juan Pablo Torres-Papaqui; Roberto Terlevich; Olac Fuentes; Elena Terlevich

    2003-11-28T23:59:59.000Z

    We present a new technique to segregate old and young stellar populations in galactic spectra using machine learning methods. We used an ensemble of classifiers, each classifier in the ensemble specializes in young or old populations and was trained with locally weighted regression and tested using ten-fold cross-validation. Since the relevant information concentrates in certain regions of the spectra we used the method of sequential floating backward selection offline for feature selection. The application to Seyfert galaxies proved that this technique is very insensitive to the dilution by the Active Galactic Nucleus (AGN) continuum. Comparing with exhaustive search we concluded that both methods are similar in terms of accuracy but the machine learning method is faster by about two orders of magnitude.

  13. THE DEEP SWIRE FIELD. IV. FIRST PROPERTIES OF THE SUB-mJy GALAXY POPULATION: REDSHIFT DISTRIBUTION, AGN ACTIVITY, AND STAR FORMATION

    SciTech Connect (OSTI)

    Strazzullo, Veronica; Pannella, Maurilio; Owen, Frazer N.; Wang, Wei-Hao [National Radio Astronomy Observatory, 1003 Lopezville Rd., Socorro, NM 87801 (United States); Bender, Ralf [Universitaets-Sternwarte, Scheinerstrasse 1, Munich D-81679 (Germany); Morrison, Glenn E. [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Shupe, David L., E-mail: vstrazzu@nrao.ed [Infrared Processing and Analysis Center, California Institute of Technology, 100-22, Pasadena, CA 91125 (United States)

    2010-05-10T23:59:59.000Z

    We present a study of a 20 cm selected sample in the Deep Spitzer Wide-area InfraRed Extragalactic Legacy Survey Very Large Array Field, reaching a 5{sigma} limiting flux density at the image center of S{sub 1.4{sub GHz}} {approx} 13.5 {mu}Jy. In a 0.6 x 0.6 deg{sup 2} field, we are able to assign an optical/IR counterpart to 97% of the radio sources. Up to 11 passbands from the NUV to 4.5 {mu}m are then used to sample the spectral energy distribution (SED) of these counterparts in order to investigate the nature of the host galaxies. By means of an SED template library and stellar population synthesis models, we estimate photometric redshifts, stellar masses, and stellar population properties, dividing the sample into three sub-classes of quiescent, intermediate, and star-forming galaxies. We focus on the radio sample in the redshift range 0.3 < z < 1.3 where we estimate to have a redshift completeness higher than 90% and study the properties and redshift evolution of these sub-populations. We find that, as expected, the relative contributions of active galactic nuclei (AGNs) and star-forming galaxies to the {mu}Jy population depend on the flux density limit of the sample. At all flux levels, a significant population of 'green-valley' galaxies is observed. While the actual nature of these sources is not definitely understood, the results of this work may suggest that a significant fraction of faint radio sources might be composite (and possibly transition) objects, thus a simple 'AGN versus star-forming' classification might not be appropriate to fully understand what faint radio populations really are.

  14. Avian population densities and species diversity on reclaimed strip-mined land in East-Central Texas

    E-Print Network [OSTI]

    Cantle, Peter Christopher

    1978-01-01T23:59:59.000Z

    . S. , Texas A&M University Cha1rman of Advisory Committee: Dr . Keith A . Arnold The objective of this study was to determine the effects of coal str1 p-mining and subsequent reclamat1on on popu'iation densities and species diversity of a native... of effects of mining and reclamation on 18 avian group associations using the study sites . . . . . 124 126 129 LIST OF FIGURES Figure Areas slated for strip-mining (A, 8 and C; stippling) near Fairfield, Texas. Solid black lines are coal vehicle haul...

  15. USING A DIFFERENTIAL EMISSION MEASURE AND DENSITY MEASUREMENTS IN AN ACTIVE REGION CORE TO TEST A STEADY HEATING MODEL

    SciTech Connect (OSTI)

    Winebarger, Amy R. [NASA Marshall Space Flight Center, VP 62, Huntsville, AL 35812 (United States); Schmelz, Joan T. [Physics Department, University of Memphis, Memphis, TN 38152 (United States); Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Saar, Steve H.; Kashyap, Vinay L., E-mail: amy.r.winebarger@nasa.gov [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

    2011-10-10T23:59:59.000Z

    The frequency of heating events in the corona is an important constraint on the coronal heating mechanisms. Observations indicate that the intensities and velocities measured in active region cores are effectively steady, suggesting that heating events occur rapidly enough to keep high-temperature active region loops close to equilibrium. In this paper, we couple observations of active region (AR) 10955 made with the X-Ray Telescope and the EUV Imaging Spectrometer on board Hinode to test a simple steady heating model. First we calculate the differential emission measure (DEM) of the apex region of the loops in the active region core. We find the DEM to be broad and peaked around 3 MK. We then determine the densities in the corresponding footpoint regions. Using potential field extrapolations to approximate the loop lengths and the density-sensitive line ratios to infer the magnitude of the heating, we build a steady heating model for the active region core and find that we can match the general properties of the observed DEM for the temperature range of 6.3 < log T < 6.7. This model, for the first time, accounts for the base pressure, loop length, and distribution of apex temperatures of the core loops. We find that the density-sensitive spectral line intensities and the bulk of the hot emission in the active region core are consistent with steady heating. We also find, however, that the steady heating model cannot address the emission observed at lower temperatures. This emission may be due to foreground or background structures, or may indicate that the heating in the core is more complicated. Different heating scenarios must be tested to determine if they have the same level of agreement.

  16. Effect of Crude Oil and Chemical Additives on Metabolic Activity of Mixed Microbial Populations in Fresh Marsh Soils

    E-Print Network [OSTI]

    Nyman, John

    Effect of Crude Oil and Chemical Additives on Metabolic Activity of Mixed Microbial Populations remineralization rates. Crude oil, which is known to contain toxins and reduce microbial diversity organic matter (Panicum hemitomon Shult. or Sagittaria lancifolia L. dominated marshes), crude oil

  17. Compost Science & Utilization, (2002), Vol.10,No. 2, 150-161 Microbial Population Dynamics and Enzyme Activities

    E-Print Network [OSTI]

    Tiquia-Arashiro, Sonia M.

    2002-01-01T23:59:59.000Z

    Compost Science & Utilization, (2002), Vol.10,No. 2, 150-161 , . Microbial Population Dynamics and Enzyme Activities During Composting Sonia M. Tiquial, Judy H.C. Wan2and Nora F.Y.Tam3 1.Environmental litter and yard trimmings. Dur- ing composting, samples were taken at three different locations (top

  18. The cosmic growth of the active black hole population at 1

    E-Print Network [OSTI]

    Schulze, A; Gavignaud, I; Schramm, M; Silverman, J; Merloni, A; Zamorani, G; Hirschmann, M; Mainieri, V; Wisotzki, L; Shankar, F; Fiore, F; Koekemoer, A M; Temporin, G

    2014-01-01T23:59:59.000Z

    We present a census of the active black hole population at 1active black hole mass function (BHMF) and the Eddington ratio distribution function (ERDF) allows to clearly disentangle the AGN downsizing phenomenon, present in the AGN luminosity function (AGN LF), into its physical processes of black hole mass downsizing and accretion rate evolution. We are utilizing type 1 AGN samples from 3 optical surveys (VVDS, zCOSMOS and SDSS), that cover a wide range of 3 dex in luminosity over our redshift interval of interest. We investigate the cosmic evolution of the AGN population as a function of AGN luminosity, black hole mass and accretion rate. Compared to z = 0 we find a distinct change in the shape of the BHMF and the ERDF, consistent with downsizing in black hole mass. The active fraction or duty cycle of type 1 AGN at z~1.5 is almost flat as...

  19. Synthesising evidence for equity impacts of population-based physical activity interventions: a pilot study

    E-Print Network [OSTI]

    Humphreys, David K; Ogilvie, David

    2013-06-15T23:59:59.000Z

    WC, Merlo A, Gewa C, Weber MD, et al. The Los Angeles Lift Off: a sociocultural environmental change intervention to integrate physical activity into the workplace. Preventive Medicine. 2004;38(6):848-56. P43. Coleman KJ, Gonzalez EC. Promoting Stair... activity patterns among adolescents: a pilot study of 'Slice of Life'. Health education research. 1987 June 1, 1987;2(2):93-103. P54. Robinson TN. Reducing children's television viewing to prevent obesity. JAMA: the journal of the American Medical...

  20. 59S.A. BALAGUERA-REINA Y J.F. GONZLEZ-MAYA-POPULATION ECOLOGY OF C. ACUTUS IN VIPIS, MAGDALENA, COLOMBIA POPULATIONSTRUCTURE,DENSITY,ANDHABITATOF

    E-Print Network [OSTI]

    Nacional Autónoma de México, Universidad

    , COLOMBIA POPULATIONSTRUCTURE,DENSITY,ANDHABITATOF CROCODYLUS ACUTUS CUVIER 1807 IN THE VIA PARQUE ISLA DE SALAMANCA,MAGDALENADEPARTMENT,COLOMBIA SERGIO A. BALAGUERA-REINA1 AND JOSE F. GONZALEZ-MAYA1,2 1 Proyecto de Conservación deAguas y Tierras, ProCAT Colombia, Calle 127B # 45­76, Bogotá, Colombia. Abstract: Information

  1. Effect of population densities, lines of seed per bed and root size on quality and yield of baby style carrots (Daucus carota Mill) in South Texas

    E-Print Network [OSTI]

    Lazcano, Carlos Alberto

    1996-01-01T23:59:59.000Z

    EFFECT OF POPULATION DENSITIKS, LINKS OF SEED PER BED AND ROOT SIZE ON QUALITY AND YIELD OF BABY STYLE CARROTS (Daucus carota Mill) IN SOUTH TEXAS A Thesis by CARLOS ALBERTO LAZCANO Submitted to the Office of Graduate Studies of Texas A... CAROTA MILL. ) IN SOUTH TEXAS A Thesis CARLOS ALBERTO LAZCANO Submitted to Texas AdtM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved as to style and content by: F Dainello (Co...

  2. Dietary, Physical Activity, and Sedentary Behaviors and Their Relationship to Weight Gain in a College Age Population

    E-Print Network [OSTI]

    Lee, Faegen Dillon

    2012-10-19T23:59:59.000Z

    ix LIST OF FIGURES Page Figure 1 Weight vs days of 30+ minutes of physical activity ------------------------------ 49 Figure 2 BMI vs days of 30+ minutes of physical activity --------------------------------- 50 Figure 3 BMI difference vs days... --------------------------------------------- 45 Table 8 Physical activity and self-reported weight loss ----------------------------------- 47 Table 9 Days of 30+ minutes of physical activity and BMI ------------------------------ 48 Table 10 Days of 30+ minutes of physical activity...

  3. Populations Population Ecology

    E-Print Network [OSTI]

    Dever, Jennifer A.

    - species interactions Abiotic factors: l Climate l Temperature l Moisture l Wind l Soil l Fire Biotic- Ã? mortality increases as population size increases or birth rate decreases" l Negative feedback

  4. OMEGA -- OSIRIS Mapping of Emission-line Galaxies in A901/2: I.-- Survey description, data analysis, and star formation and AGN activity in the highest density regions

    E-Print Network [OSTI]

    Chies-Santos, Ana L; Aragón-Salamanca, Alfonso; Bamford, Steven P; Gray, Meghan E; Wolf, Christian; Böhm, Asmus; Maltby, David T; Pintos-Castro, Irene; Sánchez-Portal, Miguel; Weinzirl, Tim

    2015-01-01T23:59:59.000Z

    We present an overview of and first results from the OMEGA survey: the OSIRIS Mapping of Emission-line Galaxies in the multi-cluster system A901/2. The ultimate goal of this project is to study star formation and AGN activity across a broad range of environments at a single redshift. Using the tuneable-filter mode of the OSIRIS instrument on GTC, we target Halpha and [NII] emission lines over a ~0.5 X 0.5 deg2 region containing the z~0.167 multi-cluster system A901/2. In this paper we describe the design of the survey, the observations and the data analysis techniques developed. We then present early results from two OSIRIS pointings centred on the cores of the A901a and A902 clusters. AGN and star-forming (SF) objects are identified using the [NII]/Halpha vs. W_Halpha (WHAN) diagnostic diagram. The AGN hosts are brighter, more massive, and possess earlier-type morphologies than SF galaxies. Both populations tend to be located towards the outskirts of the high density regions we study. The typical Halpha lumi...

  5. An evaluation of the single turnover (STO) procedure as a method for the determination of the active site densities on dispersed metal catalysts

    SciTech Connect (OSTI)

    Augustine, R.L.; Baum, D.R.; High, K.G.; Szivos, L.S.; O'Leary, S.T. (Seton Hall Univ., South Orange, NJ (USA))

    1991-02-01T23:59:59.000Z

    The extent of 2-butene formation during the STO reactions over Pd and Rh indicates that the alkene isomerization is nonstoichiometric. With Pt the extent of isomerization is also influenced by flow rate and reactant pulse size but to a lesser extent. Thus, the STO reaction procedure cannot be used for the determination of isomerization site densities on any of these catalysts. This procedure has been used to determine the saturation site densities on the EuroPt-I Pt/SiO{sub 2} and some northwestern Pt/SiO{sub 2} catalysts. The STO reaction sequence has also been run over Pt, Pd, and Rh catalysts using each of the isomeric butenes as the reactant alkene. Over all three catalysts the same amounts of direct and two-step saturation were observed regardless of the starting alkene showing that these saturation sites are not sensitive to the geometry of the reactant olefin. With Rh a near equilibrium mixture of all three double bond isomers is formed from each of the three starting alkenes. With Pt the extent of isomerization is characteristically low regardless of the starting olefin, so the low isomerization observed during the STO reaction of 1-butene on Pt is not the result of the formation of a primary metalalkyl on a large number of isomerization sites. The STO determined reactive site densities have been correlated with transition electron microscopy (TEM) measured metal particle sizes and turnover frequency (TOF) data for a number of reactions. From these results the sites on which specific reactions take place have been determined as has the site TOF for each of the active sites involved.

  6. annual plant populations: Topics by E-print Network

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

    DEMOGRAPHY IN PLANTAGO:VARIATION AMONG COHORTS IN A NATURAL PLANT POPULATION DEBORAH A Roach,. Deborah 67 PLANT-ANIMAL INTERACTIONS -ORIGINAL PAPER Population density of North...

  7. DATA SHARING REPORT CHARACTERIZATION OF POPULATION 7: PERSONAL PROTECTIVE EQUIPMENT, DRY ACTIVE WASTE, AND MISCELLANEOUS DEBRIS, SURVEILLANCE AND MAINTENANCE PROJECT OAK RIDGE NATIONAL LABORATORY OAK RIDGE, TENNESSEE

    SciTech Connect (OSTI)

    Harpenau, Evan M

    2013-10-10T23:59:59.000Z

    The U.S. Department of Energy (DOE) Oak Ridge Office of Environmental Management (EM-OR) requested that Oak Ridge Associated Universities (ORAU), working under the Oak Ridge Institute for Science and Education (ORISE) contract, provide technical and independent waste management planning support under the American Recovery and Reinvestment Act (ARRA). Specifically, DOE EM-OR requested that ORAU plan and implement a sampling and analysis campaign targeting certain URS|CH2M Oak Ridge, LLC (UCOR) surveillance and maintenance (S&M) process inventory waste. Eight populations of historical and reoccurring S&M waste at the Oak Ridge National Laboratory (ORNL) have been identified in the Waste Handling Plan for Surveillance and Maintenance Activities at the Oak Ridge National Laboratory, DOE/OR/01-2565&D2 (WHP) (DOE 2012) for evaluation and processing to determine a final pathway for disposal. Population 7 (POP 7) consists of 56 containers of aged, low-level and potentially mixed S&M waste that has been staged in various locations around ORNL. Several of these POP 7 containers primarily contain personal protective equipment (PPE) and dry active waste (DAW), but may contain other miscellaneous debris. This data sharing report addresses the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) specified waste in a 13-container subpopulation (including eight steel boxes, three 55-gal drums, one sealand, and one intermodal) that lacked sufficient characterization data for possible disposal at the Environmental Management Waste Management Facility (EMWMF) using the approved Waste Lot (WL) 108.1 profile.

  8. "Revealing a Population of Heavily Obscured Active Galactic Nuclei at z=0.5-1 in the Chandra Deep Field-South

    E-Print Network [OSTI]

    Luo, B; Xue, Y Q; Alexander, D M; Brusa, M; Bauer, F E; Comastri, A; Fabian, A C; Gilli, R; Lehmer, B D; Rafferty, D A; Schneider, D P; Vignali, C

    2011-01-01T23:59:59.000Z

    (abridged) We identify a numerically significant population of heavily obscured AGNs at z~0.5-1 in the Chandra Deep Field-South (CDF-S) and Extended Chandra Deep Field-South by selecting 242 X-ray undetected objects with infrared-based star formation rates (SFRs) substantially higher (a factor of 3.2 or more) than their SFRs determined from the UV after correcting for dust extinction. An X-ray stacking analysis of 23 candidates in the central CDF-S region using the 4 Ms Chandra data reveals a hard X-ray signal with an effective power-law photon index of Gamma=0.6_{-0.4}^{+0.3}, indicating a significant contribution from obscured AGNs. Based on Monte Carlo simulations, we conclude that 74+-25% of the selected galaxies host obscured AGNs, within which ~95% are heavily obscured and ~80% are Compton-thick (CT; NH>1.5x10^{24} cm^{-2}). The heavily obscured objects in our sample are of moderate intrinsic X-ray luminosity [ ~ (0.9-4)x10^{42} erg/s in the 2-10 keV band]. The space density of the CT AGNs is (1.6+-0.5)...

  9. Programmed population control by cellcell communication

    E-Print Network [OSTI]

    You, Lingchong

    that autonomously regulates the density of an Escherichia coli population. The cell density is broadcasted from the marine bacterium Vibrio fischeri13,14 synthesizes a small, diffusible acyl-homoserine lactone

  10. CONTROL OF POPULATION DENSITIES SURROUNDING NUCLEAR POWER PLANTS. VOLUME 5 OF THE FINAL REPORT ON HEALTH AND SAFETY IMPACTS OF NUCLEAR, GEOTHERMAL, AND FOSSIL-FUEL ELECTRIC GENERATION IN CALIFORNIA

    E-Print Network [OSTI]

    Nero, jA.V.

    2010-01-01T23:59:59.000Z

    Related Standards for Nuclear Power Plants," by A.V. NeroResponse Planning for Nuclear Power Plants in California,"Densities Surrounding Nuclear Power Plants," by A.V. Nero,

  11. Microbial Activity, Growth, and Mortality in Environmental Assemblages: Population and Community Response to Rewetting of a Dry Mediterranean Soil and Anaerobic Methane Cycling in Tropical and Boreal Soils

    E-Print Network [OSTI]

    Blazewicz, Steven Joseph

    2012-01-01T23:59:59.000Z

    G+C Content and Isotope Enrichment on DNA Density. AppliedG+C Content and Isotope Enrichment on DNA Density. Appliedenrichment in 13 C-CO 2 was from biologically mediated isotope

  12. Impact of entrainment and impingement on fish populations in the Hudson River Estuary. Volume II. Impingement impact analyses, evaluations of alternative screening devices, and critiques of utility testimony relating to density-dependent growth, the age-composition of the striped bass spawning stock, and the LMS real-time life cycle model

    SciTech Connect (OSTI)

    Barnthouse, L. W.; Van Winkle, W.; Golumbek, J.; Cada, G. F.; Goodyear, C. P.; Christensen, S. W.; Cannon, J. B.; Lee, D. W.

    1982-04-01T23:59:59.000Z

    This volume includes a series of four exhibits relating to impacts of impingement on fish populations, together with a collection of critical evaluations of testimony prepared for the utilities by their consultants. The first exhibit is a quantitative evaluation of four sources of bias (collection efficiency, reimpingement, impingement on inoperative screens, and impingement survival) affecting estimates of the number of fish killed at Hudson River power plants. The two following exhibits contain, respectively, a detailed assessment of the impact of impingement on the Hudson River white perch population and estimates of conditional impingement mortality rates for seven Hudson River fish populations. The fourth exhibit is an evaluation of the engineering feasibility and potential biological effectiveness of several types of modified intake structures proposed as alternatives to cooling towers for reducing impingement impacts. The remainder of Volume II consists of critical evaluations of the utilities' empirical evidence for the existence of density-dependent growth in young-of-the-year striped bass and white perch, of their estimate of the age-composition of the striped bass spawning stock in the Hudson River, and of their use of the Lawler, Matusky, and Skelly (LMS) Real-Time Life Cycle Model to estimate the impact of entrainment and impingement on the Hudson River striped bass population.

  13. MICROBIAL POPULATIONS FECAL PELLETS AND

    E-Print Network [OSTI]

    Luther, Douglas S.

    MICROBIAL POPULATIONS FECAL PELLETS AND AND BIOLU}IINESCENCEOF OCEANIC SEDII,IENTTRAP PARTICLES activities of microbial populations associated with fecal pellets col-Lecteo from oceanic zooplankton were (indicators of microbial growth and reproduction rates, respectively) were monitored in fecal pellets at time

  14. Estimated population near uranium tailings

    SciTech Connect (OSTI)

    Bloomster, C.H.; Brown, D.R.; Bruno, G.A.; Craig, S.N.; Dirks, J.A.; Griffin, E.A.; Reis, J.W.; Young, J.K.

    1984-01-01T23:59:59.000Z

    Population studies, which took place during the months of April, May, and June 1983, were performed for 27 active and 25 inactive mill sites. For each mill site, a table showing population by radius (1/2, 1, 2, 3, 4, and 5 km) in 16 compass directions was generated. 22 references, 6 tables.

  15. Density Log At Valles Caldera - Redondo Geothermal Area (Rowley...

    Open Energy Info (EERE)

    Rowley, Et Al., 1987) Exploration Activity Details Location Valles Caldera - Redondo Geothermal Area Exploration Technique Density Log Activity Date 1984 - 1984 Usefulness not...

  16. Density Functional Study of the Structure, Stability and Oxygen...

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

    Study of the Structure, Stability and Oxygen Reduction Activity of Ultrathin Platinum Nanowires. Density Functional Study of the Structure, Stability and Oxygen Reduction Activity...

  17. Occupational Populations

    E-Print Network [OSTI]

    unknown authors

    ? The general population may be exposed to radon in indoor and outdoor air and drinking water. ? The primary source of indoor radon is from soil; radon in the soil can enter the home through cracks in the floors, walls, or foundations. The release of radon from water may also contribute to indoor levels. ? Exposures to radon gas are accompanied by exposure to radon progeny which are the decay products of radon-222 [e.g., bismuth-214 ( 214 Bi), lead-210 ( 210 Pb), 214 Pb, polonium-210 ( 210 Po), and 218 Po.

  18. Radio faint AGN: a tale of two populations

    E-Print Network [OSTI]

    Padovani, P; Kellermann, K I; Miller, N; Mainieri, V; Tozzi, P

    2015-01-01T23:59:59.000Z

    We study the Extended Chandra Deep Field South (E-CDFS) Very Large Array sample, which reaches a flux density limit at 1.4 GHz of 32.5 microJy at the field centre and redshift ~ 4, and covers ~ 0.3 deg^2. Number counts are presented for the whole sample while the evolutionary properties and luminosity functions are derived for active galactic nuclei (AGN). The faint radio sky contains two totally distinct AGN populations, characterised by very different evolutions, luminosity functions, and Eddington ratios: radio-quiet (RQ)/radiative-mode, and radio-loud/jet-mode AGN. The radio power of RQ AGN evolves ~ (1+z)^2.5, similarly to star-forming galaxies, while the number density of radio-loud ones has a peak at ~ 0.5 and then declines at higher redshifts. The number density of radio-selected RQ AGN is consistent with that of X-ray selected AGN, which shows that we are sampling the same population. The unbiased fraction of radiative-mode RL AGN, derived from our own and previously published data, is a strong funct...

  19. Unbiased estimators of wildlife population densities using aural information

    E-Print Network [OSTI]

    Durland, Eric Newton

    1969-01-01T23:59:59.000Z

    Peters' Data . 3. 4 Suggestions for Improvements DISCUSSION AND CONCLUSIONS 18 20 22 25 28 BIBLIOGRAPHY. VITA. . . . ~ 4. 1 Situation I. 4. 2 Situation II 4. 3 Situation III. . ~ . . ~ ~ - . ~ 4. 4 Combining Aural and Visual Information 4. 5... with much promise among people in wildlife when compared with other methods of estimation. Peters [15] found that the call-count index of mourning doves seems to be sub)ect to less variation than road count data. The Southeastern Association [18] found...

  20. The relationships between net primary productivity, human population density

    E-Print Network [OSTI]

    Hansen, Andrew J.

    ). The rate of NPP is determined by the conversion of solar energy to plant matter via photosynthesis, NSW, 2640, Australia Correspondence: Gary Luck, Institute for Land, Water and Society, Charles Sturt University, PO Box 789, Albury, NSW, 2640, Australia. E-mail: galuck@csu.edu.au ABSTRACT Aim In this study, I

  1. Estimates of cetacean abundance, biomass, and population density are

    E-Print Network [OSTI]

    ) and in understanding the eco- logical role of cetaceans in marine ecosystems (Trites et al., 1997). Along the U.S. west., 1997). Large whales also die from ship strikes (Carretta et al., 2006). West coast cetaceans may be affected by anthropogenic sound (e.g., sonar, ship noise, and seismic surveys) and cli- mate change

  2. Pair densities in density functional theory

    E-Print Network [OSTI]

    Chen, Huajie

    2015-01-01T23:59:59.000Z

    The exact interaction energy of a many-electron system is determined by the electron pair density, which is not well-approximated in standard Kohn-Sham density functional models. Here we study the (complicated but well-defined) exact universal map from density to pair density. We show that many common functionals, including the most basic version of the LDA (Dirac exchange with no correlation contribution), arise from particular approximations of this map. We develop an algorithm to compute the map numerically, and apply it to one-parameter families {a*rho(a*x)} of one-dimensional homogeneous and inhomogeneous single-particle densities. We observe that the pair density develops remarkable multiscale patterns which strongly depend on both the particle number and the "width" 1/a of the single-particle density. The simulation results are confirmed by rigorous asymptotic results in the limiting regimes a>>1 and a<<1. For one-dimensional homogeneous systems, we show that the whole spectrum of patterns is rep...

  3. Equation for liquid density

    SciTech Connect (OSTI)

    Yaws, C.L.; Yang, H.C.; Hopper, J.R.; Cawley, W.A. (Lamar Univ., Beaumont, TX (US))

    1991-01-01T23:59:59.000Z

    Saturated liquid densities for organic chemicals are given as functions of temperature using a modified Rackett equation.

  4. Urban characteristics attributable to density-driven tie formation

    E-Print Network [OSTI]

    Pan, Wei

    Motivated by empirical evidence on the interplay between geography, population density and societal interaction, we propose a generative process for the evolution of social structure in cities. Our analytical and simulation ...

  5. Causes and consequences of complex population dynamics in an annual plant, Cardamine pensylvanica

    SciTech Connect (OSTI)

    Crone, E.E.

    1995-11-08T23:59:59.000Z

    The relative importance of density-dependent and density-independent factors in determining the population dynamics of plants has been widely debated with little resolution. In this thesis, the author explores the effects of density-dependent population regulation on population dynamics in Cardamine pensylvanica, an annual plant. In the first chapter, she shows that experimental populations of C. pensylvanica cycled from high to low density in controlled constant-environment conditions. These cycles could not be explained by external environmental changes or simple models of direct density dependence (N{sub t+1} = f[N{sub t}]), but they could be explained by delayed density dependence (N{sub t+1} = f[N{sub t}, N{sub t+1}]). In the second chapter, she shows that the difference in the stability properties of population growth models with and without delayed density dependence is due to the presence of Hopf as well as slip bifurcations from stable to chaotic population dynamics. She also measures delayed density dependence due to effects of parental density on offspring quality in C. pensylvanica and shows that this is large enough to be the cause of the population dynamics observed in C. pensylvanica. In the third chapter, the author extends her analyses of density-dependent population growth models to include interactions between competing species. In the final chapter, she compares the effects of fixed spatial environmental variation and variation in population size on the evolutionary response of C. pensylvanica populations.

  6. Statistical inference for density dependent Markovian forestry models

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Statistical inference for density dependent Markovian forestry models Abstract A stochastic forestry model with a density-dependence structure is studied. The population evolves in discrete roughly speaking, becomes large. From the perspective of the analysis of forestry data and predict

  7. Density-dependent covariant energy density functionals

    SciTech Connect (OSTI)

    Lalazissis, G. A. [Physics Department, Aristotle University of Thessaloniki, GR-54124 (Greece)

    2012-10-20T23:59:59.000Z

    Relativistic nuclear energy density functionals are applied to the description of a variety of nuclear structure phenomena at and away fromstability line. Isoscalar monopole, isovector dipole and isoscalar quadrupole giant resonances are calculated using fully self-consistent relativistic quasiparticle randomphase approximation, based on the relativistic Hartree-Bogoliubovmodel. The impact of pairing correlations on the fission barriers in heavy and superheavy nuclei is examined. The role of pion in constructing desnity functionals is also investigated.

  8. Population Analysis, Fall 2005 1 Population Analyses

    E-Print Network [OSTI]

    Clark, William R.

    Population Analysis, Fall 2005 1 Population Analyses EEOB/AEcl 611 Fall Semester 2005 Scheduled Phone: 294-5176 email: wrclark@iastate.edu AEcl 611 is evolving in response to very rapid changes. The emphasis in AEcl 611 is on understanding the statistical basis of various analytical techniques, applying

  9. Parasite mediated selection, sex and diapause in a natural population of Daphnia 

    E-Print Network [OSTI]

    Duncan, Alison B

    Parasites are thought to have large effects on their host populations, driving genetic change, population density changes, speciation and be a major selective force maintaining sexual reproduction. Indirect signatures of ...

  10. Survival and activity of Streptococcus faecalis and Escherichia coli in tropical freshwater

    SciTech Connect (OSTI)

    Muniz, I.; Jimenez, L.; Toranzos, G.A.; Hazen, T.C. [Univ. of Puerto Rico, Rio Piedras (Puerto Rico)

    1988-12-31T23:59:59.000Z

    The survival of Streptococcus facecalis and Escherichia coli was studied in situ in a tropical rain forest watershed using membrane diffusion chambers. Densities were determined by acridine orange direct count and Coulter Counter. Population activity was determined by microautoradiography, cell respiration, and by nucleic acid composition. Densities of S. facecalis and E. coli decreased less than 1 log unit after 105 h as measured by direct count methods. Activity as measured by respiration, acridine orange activity, and microautoradiography indicated that both bacteria remained moderately active during the entire study. After 12 h, E. coli was more active than S. faecalis as measured by nucleic acid composition. E. coli and S. faecalis survived and remained active for more than 5 days. Consequently, both would seem to be unsuitable as indicators of recent fecal contamination in tropical waters.

  11. High density matter

    E-Print Network [OSTI]

    J. R. Stone

    2013-02-11T23:59:59.000Z

    The microscopic composition and properties of matter at super-saturation densities have been the subject of intense investigation for decades. The scarcity of experimental and observational data has lead to the necessary reliance on theoretical models. However, there remains great uncertainty in these models, which, of necessity, have to go beyond the over-simple assumption that high density matter consists only of nucleons and leptons. Heavy strange baryons, mesons and quark matter in different forms and phases have to be included to fulfil basic requirements of fundamental laws of physics. In this review the latest developments in construction of the Equation of State (EoS) of high-density matter at zero and finite temperature assuming different composition of the matter are surveyed. Critical comparison of model EoS with available observational data on neutron stars, including gravitational masses, radii and cooling patterns is presented. The effect of changing rotational frequency on the composition of neutron stars during their lifetime is demonstrated. Compatibility of EoS of high-density, low temperature compact objects and low density, high temperature matter created in heavy-ion collisions is discussed.

  12. Density Matrix Topological Insulators

    E-Print Network [OSTI]

    A. Rivas; O. Viyuela; M. A. Martin-Delgado

    2013-10-31T23:59:59.000Z

    Thermal noise can destroy topological insulators (TI). However we demonstrate how TIs can be made stable in dissipative systems. To that aim, we introduce the notion of band Liouvillian as the dissipative counterpart of band Hamiltonian, and show a method to evaluate the topological order of its steady state. This is based on a generalization of the Chern number valid for general mixed states (referred to as density matrix Chern value), which witnesses topological order in a system coupled to external noise. Additionally, we study its relation with the electrical conductivity at finite temperature, which is not a topological property. Nonetheless, the density matrix Chern value represents the part of the conductivity which is topological due to the presence of quantum mixed edge states at finite temperature. To make our formalism concrete, we apply these concepts to the two-dimensional Haldane model in the presence of thermal dissipation, but our results hold for arbitrary dimensions and density matrices.

  13. Estimating Traveler Populations at Airport and Cruise Terminals for Population Distribution and Dynamics

    SciTech Connect (OSTI)

    Jochem, Warren C [ORNL; Sims, Kelly M [ORNL; Bright, Eddie A [ORNL; Urban, Marie L [ORNL; Rose, Amy N [ORNL; Coleman, Phil R [ORNL; Bhaduri, Budhendra L [ORNL

    2013-01-01T23:59:59.000Z

    In recent years, uses of high-resolution population distribution databases are increasing steadily for environmental, socioeconomic, public health, and disaster-related research and operations. With the development of daytime population distribution, temporal resolution of such databases has been improved. However, the lack of incorporation of transitional population, namely business and leisure travelers, leaves a significant population unaccounted for within the critical infrastructure networks, such as at transportation hubs. This paper presents two general methodologies for estimating passenger populations in airport and cruise port terminals at a high temporal resolution which can be incorporated into existing population distribution models. The methodologies are geographically scalable and are based on, and demonstrate how, two different transportation hubs with disparate temporal population dynamics can be modeled utilizing publicly available databases including novel data sources of flight activity from the Internet which are updated in near-real time. The airport population estimation model shows great potential for rapid implementation for a large collection of airports on a national scale, and the results suggest reasonable accuracy in the estimated passenger traffic. By incorporating population dynamics at high temporal resolutions into population distribution models, we hope to improve the estimates of populations exposed to or at risk to disasters, thereby improving emergency planning and response, and leading to more informed policy decisions.

  14. Tracing spiral density waves in M81

    E-Print Network [OSTI]

    S. Kendall; R. C. Kennicutt; C. Clarke; M. D. Thornley

    2008-04-15T23:59:59.000Z

    We use SPITZER IRAC 3.6 and 4.5micron near infrared data from the Spitzer Infrared Nearby Galaxies Survey (SINGS), optical B, V and I and 2MASS Ks band data to produce mass surface density maps of M81. The IRAC 3.6 and 4.5micron data, whilst dominated by emission from old stellar populations, is corrected for small-scale contamination by young stars and PAH emission. The I band data are used to produce a mass surface density map by a B-V colour-correction, following the method of Bell and de Jong. We fit a bulge and exponential disc to each mass map, and subtract these components to reveal the non-axisymmetric mass surface density. From the residual mass maps we are able to extract the amplitude and phase of the density wave, using azimuthal profiles. The response of the gas is observed via dust emission in the 8micron IRAC band, allowing a comparison between the phase of the stellar density wave and gas shock. The relationship between this angular offset and radius suggests that the spiral structure is reasonably long lived and allows the position of corotation to be determined.

  15. Multiple density layered insulator

    DOE Patents [OSTI]

    Alger, Terry W. (Tracy, CA)

    1994-01-01T23:59:59.000Z

    A multiple density layered insulator for use with a laser is disclosed wh provides at least two different insulation materials for a laser discharge tube, where the two insulation materials have different thermoconductivities. The multiple layer insulation materials provide for improved thermoconductivity capability for improved laser operation.

  16. Multiple density layered insulator

    DOE Patents [OSTI]

    Alger, T.W.

    1994-09-06T23:59:59.000Z

    A multiple density layered insulator for use with a laser is disclosed which provides at least two different insulation materials for a laser discharge tube, where the two insulation materials have different thermoconductivities. The multiple layer insulation materials provide for improved thermoconductivity capability for improved laser operation. 4 figs.

  17. Energy in density gradient

    E-Print Network [OSTI]

    Vranjes, J

    2015-01-01T23:59:59.000Z

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

  18. Density equalizing map projections: A new algorithm

    SciTech Connect (OSTI)

    Merrill, D.W.; Selvin, S.; Mohr, M.S.

    1992-02-01T23:59:59.000Z

    In the study of geographic disease clusters, an alternative to traditional methods based on rates is to analyze case locations on a transformed map in which population density is everywhere equal. Although the analyst`s task is thereby simplified, the specification of the density equalizing map projection (DEMP) itself is not simple and continues to be the subject of considerable research. Here a new DEMP algorithm is described, which avoids some of the difficulties of earlier approaches. The new algorithm (a) avoids illegal overlapping of transformed polygons; (b) finds the unique solution that minimizes map distortion; (c) provides constant magnification over each map polygon; (d) defines a continuous transformation over the entire map domain; (e) defines an inverse transformation; (f) can accept optional constraints such as fixed boundaries; and (g) can use commercially supported minimization software. Work is continuing to improve computing efficiency and improve the algorithm.

  19. Density equalizing map projections: A new algorithm

    SciTech Connect (OSTI)

    Merrill, D.W.; Selvin, S.; Mohr, M.S.

    1992-02-01T23:59:59.000Z

    In the study of geographic disease clusters, an alternative to traditional methods based on rates is to analyze case locations on a transformed map in which population density is everywhere equal. Although the analyst's task is thereby simplified, the specification of the density equalizing map projection (DEMP) itself is not simple and continues to be the subject of considerable research. Here a new DEMP algorithm is described, which avoids some of the difficulties of earlier approaches. The new algorithm (a) avoids illegal overlapping of transformed polygons; (b) finds the unique solution that minimizes map distortion; (c) provides constant magnification over each map polygon; (d) defines a continuous transformation over the entire map domain; (e) defines an inverse transformation; (f) can accept optional constraints such as fixed boundaries; and (g) can use commercially supported minimization software. Work is continuing to improve computing efficiency and improve the algorithm.

  20. High Energy Density Capacitors

    SciTech Connect (OSTI)

    None

    2010-07-01T23:59:59.000Z

    BEEST Project: Recapping is developing a capacitor that could rival the energy storage potential and price of today’s best EV batteries. When power is needed, the capacitor rapidly releases its stored energy, similar to lightning being discharged from a cloud. Capacitors are an ideal substitute for batteries if their energy storage capacity can be improved. Recapping is addressing storage capacity by experimenting with the material that separates the positive and negative electrodes of its capacitors. These separators could significantly improve the energy density of electrochemical devices.

  1. Gluon density in nuclei

    SciTech Connect (OSTI)

    Ayala, A.L. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica][Pelotas Univ., RS (Brazil). Inst. de Fisica e Matematica; Ducati, M.B.G. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica; Levin, E.M. [Fermi National Accelerator Lab., Batavia, IL (United States)][Nuclear Physics Inst., St. Petersburg (Russian Federation)

    1996-10-01T23:59:59.000Z

    In this talk we present our detailed study (theory and numbers) on the shadowing corrections to the gluon structure functions for nuclei. Starting from rather controversial information on the nucleon structure function which is originated by the recent HERA data, we develop the Glauber approach for the gluon density in a nucleus based on Mueller formula and estimate the value of the shadowing corrections in this case. Then we calculate the first corrections to the Glauber approach and show that these corrections are big. Based on this practical observation we suggest the new evolution equation which takes into account the shadowing corrections and solve it. We hope to convince you that the new evolution equation gives a good theoretical tool to treat the shadowing corrections for the gluons density in a nucleus and, therefore, it is able to provide the theoretically reliable initial conditions for the time evolution of the nucleus-nucleus cascade. The initial conditions should be fixed both theoretically and phenomenologically before to attack such complicated problems as the mixture of hard and soft processes in nucleus-nucleus interactions at high energy or the theoretically reliable approach to hadron or/and parton cascades for high energy nucleus-nucleus interaction. 35 refs., 24 figs., 1 tab.

  2. Population segments with disabilities

    E-Print Network [OSTI]

    Stough, Laura

    with disabilities given the large prevalence of this population throughout the world, the intensity of their social vulnerabilities in disaster, and recent federal mandates that specify equal access for individuals with disabilities to emergency preparedness..., as “special needs” populations. More recently, the functional-needs approach to defining disability-related needs during disaster was adopted by the Federal Emergency Management Agency (2010) in its Comprehensive Preparedness Guide 101 and in the National...

  3. Longitudinal density monitor for the LHC

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

    Jeff, A.; Andersen, M.; Boccardi, A.; Bozyigit, S.; Bravin, E.; Lefevre, T.; Rabiller, A.; Roncarolo, F.; Welsch, C. P.; Fisher, A. S.

    2012-03-01T23:59:59.000Z

    The longitudinal density monitor (LDM) is primarily intended for the measurement of the particle population in nominally empty rf buckets. These so-called satellite or ghost bunches can cause problems for machine protection as well as influencing the luminosity calibration of the LHC. The high dynamic range of the system allows measurement of ghost bunches with as little as 0.01% of the main bunch population at the same time as characterization of the main bunches. The LDM is a single-photon counting system using visible synchrotron light. The photon detector is a silicon avalanche photodiode operated in Geiger mode, which allows the longitudinal distribution of the LHC beams to be measured with a resolution of 90 ps. Results from the LDM are presented, including a proposed method for constructing a 3-dimensional beam density map by scanning the LDM sensor in the transverse plane. In addition, we present a scheme to improve the sensitivity of the system by using an optical switching technique.

  4. Low density microcellular foams

    DOE Patents [OSTI]

    LeMay, James D. (Castro Valley, CA)

    1991-01-01T23:59:59.000Z

    Disclosed is a process of producing microcellular foam which comprises the steps of: (a) selecting a multifunctional epoxy oligomer resin; (b) mixing said epoxy resin with a non-reactive diluent to form a resin-diluent mixture; (c) forming a diluent containing cross-linked epoxy gel from said resin-diluent mixture; (d) replacing said diluent with a solvent therefore; (e) replacing said solvent with liquid carbon dioxide; and (f) vaporizing off said liquid carbon dioxide under supercritical conditions, whereby a foam having a density in the range of 35-150 mg/cc and cell diameters less than about 1 .mu.m is produced. Also disclosed are the foams produced by the process.

  5. Low density microcellular foams

    DOE Patents [OSTI]

    LeMay, James D. (Castro Valley, CA)

    1992-01-01T23:59:59.000Z

    Disclosed is a process of producing microcellular from which comprises the steps of: (a) selecting a multifunctional epoxy oligomer resin; (b) mixing said epoxy resin with a non-reactive diluent to form a resin-diluent mixture; (c) forming a diluent containing cross-linked epoxy gel from said resin-diluent mixture; (d) replacing said diluent with a solvent therefore; (e) replacing said solvent with liquid carbon dioxide; and (f) vaporizing off said liquid carbon dioxide under supercritical conditions, whereby a foam having a density in the range of 35-150 mg/cc and cell diameters less than about 1 .mu.m is produced. Also disclosed are the foams produced by the process.

  6. Density constrained TDHF

    E-Print Network [OSTI]

    Oberacker, V E

    2015-01-01T23:59:59.000Z

    In this manuscript we provide an outline of the numerical methods used in implementing the density constrained time-dependent Hartree-Fock (DC-TDHF) method and provide a few examples of its application to nuclear fusion. In this approach, dynamic microscopic calculations are carried out on a three-dimensional lattice and there are no adjustable parameters, the only input is the Skyrme effective NN interaction. After a review of the DC-TDHF theory and the numerical methods, we present results for heavy-ion potentials $V(R)$, coordinate-dependent mass parameters $M(R)$, and precompound excitation energies $E^{*}(R)$ for a variety of heavy-ion reactions. Using fusion barrier penetrabilities, we calculate total fusion cross sections $\\sigma(E_\\mathrm{c.m.})$ for reactions between both stable and neutron-rich nuclei. We also determine capture cross sections for hot fusion reactions leading to the formation of superheavy elements.

  7. Low density microcellular foams

    DOE Patents [OSTI]

    LeMay, J.D.

    1991-11-19T23:59:59.000Z

    Disclosed is a process of producing microcellular foam which comprises the steps of: (a) selecting a multifunctional epoxy oligomer resin; (b) mixing said epoxy resin with a non-reactive diluent to form a resin-diluent mixture; (c) forming a diluent containing cross-linked epoxy gel from said resin-diluent mixture; (d) replacing said diluent with a solvent therefore; (e) replacing said solvent with liquid carbon dioxide; and (f) vaporizing off said liquid carbon dioxide under supercritical conditions, whereby a foam having a density in the range of 35-150 mg/cc and cell diameters less than about 1 [mu]m is produced. Also disclosed are the foams produced by the process. 8 figures.

  8. Nuclear Energy Density Optimization

    E-Print Network [OSTI]

    M. Kortelainen; T. Lesinski; J. Moré; W. Nazarewicz; J. Sarich; N. Schunck; M. V. Stoitsov; S. Wild

    2010-05-27T23:59:59.000Z

    We carry out state-of-the-art optimization of a nuclear energy density of Skyrme type in the framework of the Hartree-Fock-Bogoliubov (HFB) theory. The particle-hole and particle-particle channels are optimized simultaneously, and the experimental data set includes both spherical and deformed nuclei. The new model-based, derivative-free optimization algorithm used in this work has been found to be significantly better than standard optimization methods in terms of reliability, speed, accuracy, and precision. The resulting parameter set UNEDFpre results in good agreement with experimental masses, radii, and deformations and seems to be free of finite-size instabilities. An estimate of the reliability of the obtained parameterization is given, based on standard statistical methods. We discuss new physics insights offered by the advanced covariance analysis.

  9. Low density microcellular foams

    DOE Patents [OSTI]

    Aubert, James H. (Albuquerque, NM); Clough, Roger L. (Albuquerque, NM); Curro, John G. (Placitas, NM); Quintana, Carlos A. (Albuquerque, NM); Russick, Edward M. (Albuquerque, NM); Shaw, Montgomery T. (Mansfield Center, CT)

    1987-01-01T23:59:59.000Z

    Low density, microporous polymer foams are provided by a process which comprises forming a solution of polymer and a suitable solvent followed by rapid cooling of the solution to form a phase-separated system and freeze the phase-separated system. The phase-separated system comprises a polymer phase and a solvent phase, each of which is substantially continuous within the other. The morphology of the polymer phase prior to and subsequent to freezing determine the morphology of the resultant foam. Both isotropic and anisotropic foams can be produced. If isotropic foams are produced, the polymer and solvent are tailored such that the solution spontaneously phase-separates prior to the point at which any component freezes. The morphology of the resultant polymer phase determines the morphology of the resultant foam and the morphology of the polymer phase is retained by cooling the system at a rate sufficient to freeze one or both components of the system before a change in morphology can occur. Anisotropic foams are produced by forming a solution of polymer and solvent that will not phase separate prior to freezing of one or both components of the solution. In such a process, the solvent typically freezes before phase separation occurs. The morphology of the resultant frozen two-phase system determines the morphology of the resultant foam. The process involves subjecting the solution to essentially one-dimensional cooling. Means for subjecting such a solvent to one-dimensional cooling are also provided. Foams having a density of less than 0.1 g/cc and a uniform cell size of less than 10 .mu.m and a volume such that the foams have a length greater than 1 cm are provided.

  10. Low density microcellular foams

    DOE Patents [OSTI]

    Aubert, J.H.; Clough, R.L.; Curro, J.G.; Quintana, C.A.; Russick, E.M.; Shaw, M.T.

    1985-10-02T23:59:59.000Z

    Low density, microporous polymer foams are provided by a process which comprises forming a solution of polymer and a suitable solvent followed by rapid cooling of the solution to form a phase-separated system and freeze the phase-separated system. The phase-separated system comprises a polymer phase and a solvent phase, each of which is substantially continuous within the other. The morphology of the polymer phase prior to and subsequent to freezing determine the morphology of the resultant foam. Both isotropic and anisotropic foams can be produced. If isotropic foams are produced, the polymer and solvent are tailored such that the solution spontaneously phase-separates prior to the point at which any component freezes. The morphology of the resultant polymer phase determines the morphology of the reusltant foam and the morphology of the polymer phase is retained by cooling the system at a rate sufficient to freeze one or both components of the system before a change in morphology can occur. Anisotropic foams are produced by forming a solution of polymer and solvent that will not phase separate prior to freezing of one or both components of the solution. In such a process, the solvent typically freezes before phase separation occurs. The morphology of the resultant frozen two-phase system determines the morphology of the resultant foam. The process involves subjecting the solution to essentially one-dimensional cooling. Foams having a density of less than 0.1 g/cc and a uniform cell size of less than 10 ..mu..m and a volume such that the foams have a length greater than 1 cm are provided.

  11. Further Developments in Orbit Ephemeris Derived Neutral Density

    E-Print Network [OSTI]

    Locke, Travis Cole

    2012-12-31T23:59:59.000Z

    /04/2002. ................................... 91 Figure 4.4 – Atmospheric Density Comparison for CHAMP on 04/17/2002. ................................... 92 Figure 4.5 – Atmospheric Density Comparison for GRACE on 08/04/2006. .................................... 93 Figure 4.6 – Atmospheric... sigma values. .... 88 Table 4.2 – Average CC values for CHAMP binned by solar activity level. ..................................... 96 Table 4.3 – Average RMS values (10-12 kg/m3) for CHAMP binned by solar activity level.............. 96 Table 4...

  12. Local thermodynamic equilibrium in rapidly heated high energy density plasmas

    SciTech Connect (OSTI)

    Aslanyan, V.; Tallents, G. J. [York Plasma Institute, Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom)

    2014-06-15T23:59:59.000Z

    Emission spectra and the dynamics of high energy density plasmas created by optical and Free Electron Lasers (FELs) depend on the populations of atomic levels. Calculations of plasma emission and ionization may be simplified by assuming Local Thermodynamic Equilibrium (LTE), where populations are given by the Saha-Boltzmann equation. LTE can be achieved at high densities when collisional processes are much more significant than radiative processes, but may not be valid if plasma conditions change rapidly. A collisional-radiative model has been used to calculate the times taken by carbon and iron plasmas to reach LTE at varying densities and heating rates. The effect of different energy deposition methods, as well as Ionization Potential Depression are explored. This work shows regimes in rapidly changing plasmas, such as those created by optical lasers and FELs, where the use of LTE is justified, because timescales for plasma changes are significantly longer than the times needed to achieve an LTE ionization balance.

  13. ATLBS EXTENDED SOURCE SAMPLE: THE EVOLUTION IN RADIO SOURCE MORPHOLOGY WITH FLUX DENSITY

    SciTech Connect (OSTI)

    Saripalli, L.; Subrahmanyan, R.; Thorat, K.; Ekers, R. D. [Raman Research Institute, C. V. Raman Avenue, Sadashivanagar, Bangalore 560080 (India); Hunstead, R. W.; Johnston, H. M.; Sadler, E. M., E-mail: lsaripal@rri.res.in [Sydney Institute for Astronomy, School of Physics, University of Sydney, NSW 2006 (Australia)

    2012-04-01T23:59:59.000Z

    Based on the Australia Telescope Low Brightness Survey (ATLBS) we present a sample of extended radio sources and derive morphological properties of faint radio sources. One hundred nineteen radio galaxies form the ATLBS Extended Source Sample (ATLBS-ESS) consisting of all sources exceeding 30'' in extent and integrated flux densities exceeding 1 mJy. We give structural details along with information on galaxy identifications and source classifications. The ATLBS-ESS, unlike samples with higher flux-density limits, has almost equal fractions of FR-I and FR-II radio galaxies, with a large fraction of the FR-I population exhibiting 3C31-type structures. Significant asymmetry in lobe extents appears to be a common occurrence in the ATLBS-ESS FR-I sources compared with FR-II sources. We present a sample of 22 FR-Is at z > 0.5 with good structural information. The detection of several giant radio sources, with size exceeding 0.7 Mpc, at z > 1 suggests that giant radio sources are not less common at high redshifts. The ESS also includes a sample of 28 restarted radio galaxies. The relative abundance of dying and restarting sources is indicative of a model where radio sources undergo episodic activity in which an active phase is followed by a brief dying phase that terminates with restarting of the central activity; in any massive elliptical a few such activity cycles wherein adjacent events blend may constitute the lifetime of a radio source and such bursts of blended activity cycles may be repeated over the age of the host. The ATLBS-ESS includes a 2 Mpc giant radio galaxy with the lowest surface brightness lobes known to date.

  14. Large-scale tidal fields on primordial density perturbations ?

    E-Print Network [OSTI]

    Alejandro Gonzalez

    1997-02-17T23:59:59.000Z

    We calculate the strength of the tidal field produced by the large-scale density field acting on primordial density perturbations in power law models. By analysing changes in the orientation of the deformation tensor, resulted from smoothing the density field on different mass scales, we show that the large-scale tidal field can strongly affect the morphology and orientation of density peaks. The measure of the strength of the tidal field is performed as a function of the distance to the peak and of the spectral index. We detected evidence that two populations of perturbations seems to coexist; one, with a misalignment between the main axes of their inertia and deformation tensors. This would lead to the angular momentum acquisition and morphological changes. For the second population, the perturbations are found nearly aligned in the direction of the tidal field, which would imprint them low angular momentum and which would allow an alignment of structures as those reported between clusters of galaxies in filaments, and between galaxies in clusters. Evidence is presented that the correlation between the orientation of perturbations and the large-scale density field could be a common property of Gaussian density fields with spectral indexes $n < 0$. We argue that alignment of structures can be used to probe the flatness of the spectrum on large scales but it cannot determine the exact value of the spectral index.

  15. Population Ecology Philip M. Dixon

    E-Print Network [OSTI]

    Population Ecology Philip M. Dixon Department of Statistics Iowa State University 20 December 2001 Population ecology is the discipline in ecology that deals with the structure and dynamics (e.g. growth interacting populations. Population ecology is closely related to other ecological disciplines, e

  16. COMPARATIVE STUDY OF POPULATIONS

    E-Print Network [OSTI]

    WOODS HOLE, MASS. SPECIAL SCIENTIFIC REPORT- FISHERIES No. 204 UNITED STATES DEPARTMENT OF THE INTERIOR OF POPULATIONS OF THE STRIPED BASS By Robert Minturn Lewis Fishery Research Biologist Special Scientific Report by Merriman (1937 and 1941), Vladykov and Wal- lace (1952), Raney and de Sylva (1953), Raney, Woolcott

  17. 862 PHYTOPATHOLOGY Population Biology

    E-Print Network [OSTI]

    McDonald, Bruce

    de Agronomía, Universidad Nacional de Colombia, Carrera 30 45-00 Bogotá, Colombia; second author potato in Colombia using 11 simple-sequence repeat (SSR) markers. In total, 288 different multilocus%. RST statistics indicated a very low level of population differentiation overall, consistent with high

  18. Generation of Gaussian Density Fields

    E-Print Network [OSTI]

    Hugo Martel

    2005-07-15T23:59:59.000Z

    This document describes analytical and numerical techniques for the generation of Gaussian density fields, which represent cosmological density perturbations. The mathematical techniques involved in the generation of density harmonics in k-space, the filtering of the density fields, and the normalization of the power spectrum to the measured temperature fluctuations of the Cosmic Microwave Background, are presented in details. These techniques are well-known amongst experts, but the current literature lacks a formal description. I hope that this technical report will prove useful to new researchers moving into this field, sparing them the task of reinventing the wheel.

  19. Minimization of Fractional Power Densities

    E-Print Network [OSTI]

    Minimization of Fractional Power Densities. Robert Hardt, Rice University. Abstract: A k dimensional rectifiable current is given by an oriented k dimensional

  20. Canonical density matrix perturbation theory

    E-Print Network [OSTI]

    Niklasson, Anders M N; Rubensson, Emanuel H; Rudberg, Elias

    2015-01-01T23:59:59.000Z

    Density matrix perturbation theory [Niklasson and Challacombe, Phys. Rev. Lett. 92, 193001 (2004)] is generalized to canonical (NVT) free energy ensembles in tight-binding, Hartree-Fock or Kohn-Sham density functional theory. The canonical density matrix perturbation theory can be used to calculate temperature dependent response properties from the coupled perturbed self-consistent field equations as in density functional perturbation theory. The method is well suited to take advantage of sparse matrix algebra to achieve linear scaling complexity in the computational cost as a function of system size for sufficiently large non-metallic materials and metals at high temperatures.

  1. Emergent vortices in populations of colloidal rollers

    E-Print Network [OSTI]

    Antoine Bricard; Jean-Baptiste-Caussin; Debasish Das; Charles Savoie; Vijayakumar Chikkadi; Kyohei Shitara; Oleksandr Chepizhko; Fernando Peruani; David Saintillan; Denis Bartolo

    2015-06-26T23:59:59.000Z

    Coherent vortical motion has been reported in a wide variety of populations including living organisms (bacteria, fishes, human crowds) and synthetic active matter (shaken grains, mixtures of biopolymers), yet a unified description of the formation and structure of this pattern remains lacking. Here we report the self-organization of motile colloids into a macroscopic steadily rotating vortex. Combining physical experiments and numerical simulations, we elucidate this collective behavior. We demonstrate that the emergent-vortex structure lives on the verge of a phase separation, and single out the very constituents responsible for this state of polar active matter. Building on this observation, we establish a continuum theory and lay out a strong foundation for the description of vortical collective motion in a broad class of motile populations constrained by geometrical boundaries.

  2. Detecting Density Variations and Nanovoids

    SciTech Connect (OSTI)

    Miller, Michael K [ORNL; Longstreth-Spoor, L. [Washington University, St. Louis; Kelton, K. F. [Washington University, St. Louis

    2011-01-01T23:59:59.000Z

    A combination of simulated and experimental data has been used to investigate the size range of nanovoids that can be detected in atom probe tomography data. Simulated atom probe tomography data have revealed that nanovoids as small as 1 nm in diameter can be detected in atom probe tomography data with the use of iso-density surfaces. Iso-density surfaces may be used to quantify the size, morphology and number density of nanovoids and other variations in density in atom probe tomography data. Experimental data from an aluminum-yttrium-iron metallic glass ribbon have revealed the effectiveness of this approach. Combining iso-density surfaces with atom maps also permits the segregation of solute to the nanovoids to be investigated. Field ion microscopy and thin section atom maps have also been used to detect pores and larger voids.

  3. Population and Climate Change:Population and Climate Change: Coupling Population Models withCoupling Population Models with

    E-Print Network [OSTI]

    Kalnay, Eugenia

    Coupling Population Models with Earth System ModelsEarth System Models Eugenia Kalnay, Safa Motesharrei, Jorge Rivas Change: Fully Coupling Population and Earth System Models" My research at the U. of Maryland #12

  4. Phenomenological Relativistic Energy Density Functionals

    SciTech Connect (OSTI)

    Lalazissis, G. A.; Kartzikos, S. [Physics Department, Aristotle University of Thessaloniki (Greece); Niksic, T.; Paar, N.; Vretenar, D. [Physics Department, University of Zagreb (Croatia); Ring, P. [Physics Department, TU Muenchen, Garching (Germany)

    2009-08-26T23:59:59.000Z

    The framework of relativistic nuclear energy density functionals is applied to the description of a variety of nuclear structure phenomena, not only in spherical and deformed nuclei along the valley of beta-stability, but also in exotic systems with extreme isospin values and close to the particle drip-lines. Dynamical aspects of exotic nuclear structure is explored using the fully consistent quasiparticle random-phase approximation based on the relativistic Hartree-Bogoliubov model. Recent applications of energy density functionals with explicit density dependence of the meson-nucleon couplings are presented.

  5. The value of density measurements in stellar coronae

    E-Print Network [OSTI]

    Jan-Uwe Ness; Carole Jordan

    2005-04-06T23:59:59.000Z

    The grating instruments on board Chandra and XMM-Newton now allow measurements of electron densities. These rely on the ratios of fluxes in emission lines, where one line depends on both collisional and radiative decay rates. The electron density is required to constrain the physical extent of the emitting region, and large samples of measurements are of interest in the context of trends in coronal activity. Here we discuss the important He {\\sc i}-like ions and the differences in densities that result when different current data bases are used.

  6. High energy density redox flow device

    DOE Patents [OSTI]

    Chiang, Yet-Ming; Carter, W. Craig; Ho, Bryan Y; Duduta, Mihai; Limthongkul, Pimpa

    2014-05-13T23:59:59.000Z

    Redox flow devices are described in which at least one of the positive electrode or negative electrode-active materials is a semi-solid or is a condensed ion-storing electroactive material, and in which at least one of the electrode-active materials is transported to and from an assembly at which the electrochemical reaction occurs, producing electrical energy. The electronic conductivity of the semi-solid is increased by the addition of conductive particles to suspensions and/or via the surface modification of the solid in semi-solids (e.g., by coating the solid with a more electron conductive coating material to increase the power of the device). High energy density and high power redox flow devices are disclosed. The redox flow devices described herein can also include one or more inventive design features. In addition, inventive chemistries for use in redox flow devices are also described.

  7. Low density metal hydride foams

    DOE Patents [OSTI]

    Maienschein, Jon L. (Oakland, CA); Barry, Patrick E. (Pleasant Hill, CA)

    1991-01-01T23:59:59.000Z

    Disclosed is a low density foam having a porosity of from 0 to 98% and a density less than about 0.67 gm/cc, prepared by heating a mixture of powered lithium hydride and beryllium hydride in an inert atmosphere at a temperature ranging from about 455 to about 490 K for a period of time sufficient to cause foaming of said mixture, and cooling the foam thus produced. Also disclosed is the process of making the foam.

  8. Maximum-likelihood density modification

    SciTech Connect (OSTI)

    Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Structural Biology Group, Mail Stop M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2000-08-01T23:59:59.000Z

    A likelihood-based density modification approach is developed that can incorporate expected electron-density information from a wide variety of sources. A likelihood-based approach to density modification is developed that can be applied to a wide variety of cases where some information about the electron density at various points in the unit cell is available. The key to the approach consists of developing likelihood functions that represent the probability that a particular value of electron density is consistent with prior expectations for the electron density at that point in the unit cell. These likelihood functions are then combined with likelihood functions based on experimental observations and with others containing any prior knowledge about structure factors to form a combined likelihood function for each structure factor. A simple and general approach to maximizing the combined likelihood function is developed. It is found that this likelihood-based approach yields greater phase improvement in model and real test cases than either conventional solvent flattening and histogram matching or a recent reciprocal-space solvent-flattening procedure [Terwilliger (1999 ?), Acta Cryst. D55, 1863–1871].

  9. SUPPRESSION OF DIELECTRONIC RECOMBINATION DUE TO FINITE DENSITY EFFECTS

    SciTech Connect (OSTI)

    Nikolic, D.; Gorczyca, T. W.; Korista, K. T. [Western Michigan University, Kalamazoo, MI (United States); Ferland, G. J. [University of Kentucky, Lexington, KY (United States); Badnell, N. R. [University of Strathclyde, Glasgow (United Kingdom)

    2013-05-01T23:59:59.000Z

    We have developed a general model for determining density-dependent effective dielectronic recombination (DR) rate coefficients in order to explore finite-density effects on the ionization balance of plasmas. Our model consists of multiplying by a suppression factor those highly-accurate total zero-density DR rate coefficients which have been produced from state-of-the-art theoretical calculations and which have been benchmarked by experiment. The suppression factor is based upon earlier detailed collision-radiative calculations which were made for a wide range of ions at various densities and temperatures, but used a simplified treatment of DR. A general suppression formula is then developed as a function of isoelectronic sequence, charge, density, and temperature. These density-dependent effective DR rate coefficients are then used in the plasma simulation code Cloudy to compute ionization balance curves for both collisionally ionized and photoionized plasmas at very low (n{sub e} = 1 cm{sup -3}) and finite (n{sub e} = 10{sup 10} cm{sup -3}) densities. We find that the denser case is significantly more ionized due to suppression of DR, warranting further studies of density effects on DR by detailed collisional-radiative calculations which utilize state-of-the-art partial DR rate coefficients. This is expected to impact the predictions of the ionization balance in denser cosmic gases such as those found in nova and supernova shells, accretion disks, and the broad emission line regions in active galactic nuclei.

  10. SECPOP90: Sector population, land fraction, and economic estimation program

    SciTech Connect (OSTI)

    Humphreys, S.L.; Rollstin, J.A.; Ridgely, J.N.

    1997-09-01T23:59:59.000Z

    In 1973 Mr. W. Athey of the Environmental Protection Agency wrote a computer program called SECPOP which calculated population estimates. Since that time, two things have changed which suggested the need for updating the original program - more recent population censuses and the widespread use of personal computers (PCs). The revised computer program uses the 1990 and 1992 Population Census information and runs on current PCs as {open_quotes}SECPOP90.{close_quotes} SECPOP90 consists of two parts: site and regional. The site provides population and economic data estimates for any location within the continental United States. Siting analysis is relatively fast running. The regional portion assesses site availability for different siting policy decisions; i.e., the impact of available sites given specific population density criteria within the continental United States. Regional analysis is slow. This report compares the SECPOP90 population estimates and the nuclear power reactor licensee-provided information. Although the source, and therefore the accuracy, of the licensee information is unknown, this comparison suggests SECPOP90 makes reasonable estimates. Given the total uncertainty in any current calculation of severe accidents, including the potential offsite consequences, the uncertainty within SECPOP90 population estimates is expected to be insignificant. 12 refs., 55 figs., 7 tabs.

  11. Optimal control of population transfer in Markovian open quantum systems

    E-Print Network [OSTI]

    Wei Cui; Zairong Xi; Yu Pan

    2010-04-27T23:59:59.000Z

    There has long been interest to control the transfer of population between specified quantum states. Recent work has optimized the control law for closed system population transfer by using a gradient ascent pulse engineer- ing algorithm [1]. Here, a spin-boson model consisting of two-level atoms which interact with the dissipative environment, is investigated. With opti- mal control, the quantum system can invert the populations of the quantum logic states. The temperature plays an important role in controlling popula- tion transfer. At low temperatures the control has active performance, while at high temperatures it has less erect. We also analyze the decoherence be- havior of open quantum systems with optimal population transfer control, and we find that these controls can prolong the coherence time. We hope that active optimal control can help quantum solid-state-based engineering.

  12. The M31 population of supersoft sources

    E-Print Network [OSTI]

    Peter Kahabka

    1999-01-12T23:59:59.000Z

    The 1991 ROSAT PSPC M31 X-ray point source catalog has been screened in order to set up a sample of candidate supersoft sources in this galaxy, additional to the 16 supersoft sources of Supper et al. (1997). 26 candidates have been found. Absorbing hydrogen column densities, effective temperatures and white dwarf masses (assuming the sources are on the stability line of surface nuclear burning) are derived. An observed white dwarf mass distribution is derived which indicates that the masses are constrained to values above 0.90 solar masses. The entire population of supersoft sources in M31 is estimated taking a theoretical white dwarf mass distribution into account, assuming that the observationally derived sample is restricted to white dwarf masses above 0.90 solar, and taking into account that the gas and the source population have a different scale height. A total number of at least 200-500 and at most 6,000-15,000 sources is deduced depending on the used galaxy N_H model, making use of the population synthesis calculation of Yungelson (1996). The spatial distribution favors a disk (or spiral-arm) dominated young stellar population with a ratio of 1/(4-7) of bulge/disk systems. Assuming that all supersoft sources with masses in excess of 0.5 solar masses are progenitors of supernovae of type Ia, a SN Ia rate of (0.8-7) 10^-3 yr^-1 is derived for M31 based on these progenitors. Supersoft sources might account for 20-100% of the total SN Ia rate in a galaxy like M31.

  13. Intercrystalline density on nanocrystalline nickel

    SciTech Connect (OSTI)

    Haasz, T.R.; Aust, K.T. [Univ. of Toronto, Ontario (Canada). Dept. of Metallurgy and Materials Science] [Univ. of Toronto, Ontario (Canada). Dept. of Metallurgy and Materials Science; Palumbo, G. [Ontario Hydro Research Div., Toronto, Ontario (Canada)] [Ontario Hydro Research Div., Toronto, Ontario (Canada); El-Sherik, A.M.; Erb, U. [Queen`s Univ., Kingston, Ontario (Canada). Dept. of Materials and Metallurgical Engineering] [Queen`s Univ., Kingston, Ontario (Canada). Dept. of Materials and Metallurgical Engineering

    1995-02-01T23:59:59.000Z

    Most methods currently available for the synthesis of nanostructured materials result in considerable residual porosity. Studies concerned with the novel structures and properties of these materials are thus compromised by the intrinsically high levels of porosity. As recently shown by Kristic et al., porosity can have a significant effect on fundamental materials properties such as Young`s modulus. One of the most promising techniques for the production of fully dense nanocrystalline materials is electrodeposition. In the present work, the residual porosity and density of nanostructured nickel produced by the electrodeposition method is assessed and discussed in light of the intrinsic intercrystalline density of nickel.

  14. Statistical density modification using local pattern matching

    SciTech Connect (OSTI)

    Terwilliger, Thomas C.

    2007-01-23T23:59:59.000Z

    A computer implemented method modifies an experimental electron density map. A set of selected known experimental and model electron density maps is provided and standard templates of electron density are created from the selected experimental and model electron density maps by clustering and averaging values of electron density in a spherical region about each point in a grid that defines each selected known experimental and model electron density maps. Histograms are also created from the selected experimental and model electron density maps that relate the value of electron density at the center of each of the spherical regions to a correlation coefficient of a density surrounding each corresponding grid point in each one of the standard templates. The standard templates and the histograms are applied to grid points on the experimental electron density map to form new estimates of electron density at each grid point in the experimental electron density map.

  15. Author's Accepted Manuscript ORBIT-CENTERED ATMOSPHERIC DENSITY

    E-Print Network [OSTI]

    Wohlberg, Brendt

    density measurements or estimates on a given orbit and a set of proxies for solar and geomagnetic solar and geomagnetic activities and different prediction windows. Compar- ison with previously (LEO) contain the majority of artificial sa- tellites currently in operation. At LEO below 700 km

  16. Optimal Seismic Network Density for Earthquake Early Warning: A Case

    E-Print Network [OSTI]

    Allen, Richard M.

    . Serdar Kuyuk and Richard M. Allen INTRODUCTION Earthquake Early Warning Systems (EEWS) rapidly detect and the public actively use early warning information is a crucial factor in early warning system design (AktasOptimal Seismic Network Density for Earthquake Early Warning: A Case Study from California by H

  17. The effects of low environmental cadmium exposure on bone density

    SciTech Connect (OSTI)

    Trzcinka-Ochocka, M., E-mail: ochocka@imp.lodz.pl [Department of Chemical Hazards, Laboratory of Biomonitoring, Nofer Institute of Occupational Medicine, Lodz (Poland); Jakubowski, M. [Department of Chemical Hazards, Laboratory of Biomonitoring, Nofer Institute of Occupational Medicine, Lodz (Poland)] [Department of Chemical Hazards, Laboratory of Biomonitoring, Nofer Institute of Occupational Medicine, Lodz (Poland); Szymczak, W. [Department of Environmental Epidemiology, Nofer Institute of Occupational Medicine, Lodz (Poland) [Department of Environmental Epidemiology, Nofer Institute of Occupational Medicine, Lodz (Poland); Insitute of Psychology, University of Lodz (Poland); Janasik, B.; Brodzka, R. [Department of Chemical Hazards, Laboratory of Biomonitoring, Nofer Institute of Occupational Medicine, Lodz (Poland)] [Department of Chemical Hazards, Laboratory of Biomonitoring, Nofer Institute of Occupational Medicine, Lodz (Poland)

    2010-04-15T23:59:59.000Z

    Recent epidemiological data indicate that low environmental exposure to cadmium, as shown by cadmium body burden (Cd-U), is associated with renal dysfunction as well as an increased risk of cadmium-induced bone disorders. The present study was designed to assess the effects of low environmental cadmium exposure, at the level sufficient to induce kidney damage, on bone metabolism and mineral density (BMD). The project was conducted in the area contaminated with cadmium, nearby a zinc smelter located in the region of Poland where heavy industry prevails. The study population comprised 170 women (mean age=39.7; 18-70 years) and 100 men (mean age=31.9; 18-76 years). Urinary and blood cadmium and the markers of renal tubular dysfunction ({beta}{sub 2}M-U RBP, NAG), glomerular dysfunction (Alb-U and {beta}{sub 2}M-S) and bone metabolism markers (BAP-S, CTX-S) as well as forearm BMD, were measured. The results of this study based on simple dose-effect analysis showed the relationship between increasing cadmium concentrations and an increased excretion of renal dysfunction markers and decreasing bone density. However, the results of the multivariate analysis did not indicate the association between exposure to cadmium and decrease in bone density. They showed that the most important factors that have impact on bone density are body weight and age in the female subjects and body weight and calcium excretion in males. Our investigation revealed that the excretion of low molecular weight proteins occurred at a lower level of cadmium exposure than the possible loss of bone mass. It seems that renal tubular markers are the most sensitive and significant indicators of early health effects of cadmium intoxication in the general population. The correlation of urinary cadmium concentration with markers of kidney dysfunction was observed in the absence of significant correlations with bone effects. Our findings did not indicate any effects of environmental cadmium exposure on bone density.

  18. Mechanical reaction-diffusion model for bacterial population dynamics

    E-Print Network [OSTI]

    Ngamsaad, Waipot

    2015-01-01T23:59:59.000Z

    The effect of mechanical interaction between cells on the spreading of bacterial population was investigated in one-dimensional space. A nonlinear reaction-diffusion equation has been formulated as a model for this dynamics. In this model, the bacterial cells are treated as the rod-like particles that interact, when contacting each other, through the hard-core repulsion. The repulsion introduces the exclusion process that causes the fast diffusion in bacterial population at high density. The propagation of the bacterial density as the traveling wave front in long time behavior has been analyzed. The analytical result reveals that the front speed is enhanced by the exclusion process---and its value depends on the packing fraction of cell. The numerical solutions of the model have been solved to confirm this prediction.

  19. Perturbation Theory for Population Dynamics

    E-Print Network [OSTI]

    Francisco M. Fernandez

    2007-12-20T23:59:59.000Z

    We prove that a recently proposed homotopy perturbation method for the treatment of population dynamics is just the Taylor expansion of the population variables about initial time. Our results show that this perturbation method fails to provide the global features of the ecosystem dynamics.

  20. Degenerate resistive switching and ultrahigh density storage in resistive memory

    SciTech Connect (OSTI)

    Lohn, Andrew J., E-mail: drewlohn@gmail.com; Mickel, Patrick R., E-mail: prmicke@sandia.gov; James, Conrad D.; Marinella, Matthew J. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

    2014-09-08T23:59:59.000Z

    We show that in tantalum oxide resistive memories, activation power provides a multi-level variable for information storage that can be set and read separately from the resistance. These two state variables (resistance and activation power) can be precisely controlled in two steps: (1) the possible activation power states are selected by partially reducing resistance, then (2) a subsequent partial increase in resistance specifies the resistance state and the final activation power state. We show that these states can be precisely written and read electrically, making this approach potentially amenable for ultra-high density memories. We provide a theoretical explanation for information storage and retrieval from activation power and experimentally demonstrate information storage in a third dimension related to the change in activation power with resistance.

  1. Active materials in photonic crystals

    E-Print Network [OSTI]

    Bermel, Peter (Peter A.)

    2007-01-01T23:59:59.000Z

    I analyze new phenomena arising from embedding active materials inside of photonic crystal structures. These structures strongly modify the photonic local density of states (LDOS), leading to quantitative and qualitative ...

  2. A current density distribution tool

    E-Print Network [OSTI]

    Jagush, Frederic A.

    1989-01-01T23:59:59.000Z

    . I. INTRODUCTION Current density distribution is an important consideration for those involved in electrochemical systems and electroplating in particular. In the printed wiring board (PWB) business, great emphasis is placed on the study of current... exist. Numerical techniques on the other hand, are usually easy to implement and are easily applicable to microcomputers. Their disadvantage as with any approximation technique is that the exactness of the results with This document follows the style...

  3. Updated Axion CDM energy density

    E-Print Network [OSTI]

    Ji-Haeng Huh

    2008-10-08T23:59:59.000Z

    We update cosmological bound on axion model. The contribution from the anharmonic effect and the newly introduced initial overshoot correction are considered. We present an explicit formula for the axion relic density in terms of the QCD scale Lambda_{QCD}, the current quark masses m_q's and the Peccei-Quinn scale F_a, including firstly introduced 1.85 factor which is from the initial overshoot.

  4. The Formation of Population III Binaries

    E-Print Network [OSTI]

    Kazuya Saigo; Tomoaki Matsumoto; Masayuki Umemura

    2004-10-29T23:59:59.000Z

    We explore the possibility for the formation of Population III binaries. The collapse of a rotating cylinder is simulated with a three-dimensional, high-resolution nested grid, assuming the thermal history of primordial gas. The simulations are done with dimensionless units, and the results are applicable to low-mass as well as massive systems by scaling with the initial density. We find that if the initial angular momentum is as small as $\\beta \\approx 0.1$, where $\\beta$ is the ratio of centrifugal force to pressure force, then the runaway collapse of the cloud stops to form a rotationally-supported disk. After the accretion of the envelope, the disk undergoes a ring instability, eventually fragmenting into a binary. If the initial angular momentum is relatively large, a bar-type instability arises, resulting in the collapse into a single star through rapid angular momentum transfer. The present results show that a significant fraction of Pop III stars are expected to form in binary systems, even if they are quite massive or less massive. The cosmological implications of Population III binaries are briefly discussed.

  5. Risk assessment for osteoporotic fractures among men and women from a prospective population study: the EPIC-Norfolk study

    E-Print Network [OSTI]

    Moayyeri, Alireza

    2012-03-06T23:59:59.000Z

    ................................................................................................ 99  6.4.  Results ................................................................................................ 101  6.4.1.  Characteristics of the study population ....................................... 101  6.4.2.  Physical activity and heel...

  6. Habitat use and population density of the houbara bustard Chlamydotis undulata in Fuerteventura (Canary

    E-Print Network [OSTI]

    Carrascal, Luis M.

    (Canary Islands) Luis M. Carrascal1 *, David Palomino2 , Javier Seoane3 and Ce´sar L. Alonso4 1 Department de Castilla-La Mancha, 45071 Toledo, Spain Abstract The houbara bustard in the Canary Islands- eventura (the largest island occupied by the species in the Canary archipelago, 1730 km2 ) and analyses its

  7. Habitat use and population density of the houbara bustard Chlamydotis undulata in Fuerteventura (Canary

    E-Print Network [OSTI]

    Carrascal, Luis M.

    (Canary Islands) Luis M. Carrascal1 *, David Palomino2 , Javier Seoane3 and Ce´sar L. Alonso4 1 Department), Universidad de Castilla-La Mancha, 45071 Toledo, Spain Abstract The houbara bustard in the Canary Islands- eventura (the largest island occupied by the species in the Canary archipelago, 1730 km2 ) and analyses its

  8. Influence of the Target - Density Effects on Electron - Capture Processes

    SciTech Connect (OSTI)

    Tolstikhina, I.Yu.; Shevelko, V.P. [P.N.Lebedev Physical Institute, 119991, Moscow (Russian Federation)

    2004-12-01T23:59:59.000Z

    The influence of the target density on the electron-capture (EC) processes in collisions of fast ions with atoms and molecules is considered. The partial EC cross sections {sigma}n on the principal quantum number n of the scattered projectile, as well as the total {sigma}tot values are calculated for highly charged ions interacting with gaseous and solid targets in the energy range of E = 100 keV/amu to 10 MeV/amu. It is shown that with the target density increasing, the population of the excited states of the scattered projectiles, formed via the EC channel, is suppressed due to projectile ionization by the target particles and, as a result, the effective EC cross sections drastically decrease.

  9. Energy Systems and Population Health

    SciTech Connect (OSTI)

    Ezzati, Majid; Bailis, Rob; Kammen, Daniel M.; Holloway, Tracey; Price, Lynn; Cifuentes, Luis A.; Barnes, Brendon; Chaurey, Akanksha; Dhanapala, Kiran N.

    2004-04-12T23:59:59.000Z

    It is well-documented that energy and energy systems have a central role in social and economic development and human welfare at all scales, from household and community to regional and national (41). Among its various welfare effects, energy is closely linked with people s health. Some of the effects of energy on health and welfare are direct. With abundant energy, more food or more frequent meals can be prepared; food can be refrigerated, increasing the types of food items that are consumed and reducing food contamination; water pumps can provide more water and eliminate the need for water storage leading to contamination or increased exposure to disease vectors such as mosquitoes or snails; water can be disinfected by boiling or using other technologies such as radiation. Other effects of energy on public health are mediated through more proximal determinants of health and disease. Abundant energy can lead to increased irrigation, agricultural productivity, and access to food and nutrition; access to energy can also increase small-scale income generation such as processing of agricultural commodities (e.g., producing refined oil from oil seeds, roasting coffee, drying and preserving fruits and meats) and production of crafts; ability to control lighting and heating allows education or economic activities to be shielded from daily or seasonal environmental constraints such as light, temperature, rainfall, or wind; time and other economic resources spent on collecting and/or transporting fuels can be used for other household needs if access to energy is facilitated; energy availability for transportation increases access to health and education facilities and allow increased economic activity by facilitating the transportation of goods and services to and from markets; energy for telecommunication technology (radio, television, telephone, or internet) provides increased access to information useful for health, education, or economic purposes; provision of energy to rural and urban health facilities allows increased delivery and coverage of 3 various health services and interventions such as tests and treatments, better storage of medicine and vaccines, disinfection of medical equipment by boiling or radiation, and more frequent and efficient health system encounters through mobile clinics or longer working hours; and so on. In fact, while the dominant view of development-energy-health linkages has been that improvements in energy and health are outcomes of the socioeconomic development process (e.g., the ''energy ladder'' framework discussed below), it has even been argued that access to higher quality energy sources and technologies can initiate a chain of demographic, health, and development outcomes by changing the household structure and socioeconomic relationships. For example, in addition to increased opportunities for food and income production, reduced infant mortality as a result of transition to cleaner fuels or increased coverage of vaccination with availability of refrigerators in rural clinics may initiate a process of ''demographic transition'' to low-mortality and low-fertility populations (14). Such a transition has historically been followed with further improvements in maternal and child health and increased female participation in the labor markets and other economic activities.

  10. Probability distribution of the vacuum energy density

    SciTech Connect (OSTI)

    Duplancic, Goran; Stefancic, Hrvoje [Theoretical Physics Division, Rudjer Boskovic Institute, P.O. Box 180, HR-10002 Zagreb (Croatia); Glavan, Drazen [Department of Physics, Faculty of Science, University of Zagreb, P.O. Box 331, HR-10002 Zagreb (Croatia)

    2010-12-15T23:59:59.000Z

    As the vacuum state of a quantum field is not an eigenstate of the Hamiltonian density, the vacuum energy density can be represented as a random variable. We present an analytical calculation of the probability distribution of the vacuum energy density for real and complex massless scalar fields in Minkowski space. The obtained probability distributions are broad and the vacuum expectation value of the Hamiltonian density is not fully representative of the vacuum energy density.

  11. High density electronic circuit and process for making

    DOE Patents [OSTI]

    Morgan, William P. (Albuquerque, NM)

    1999-01-01T23:59:59.000Z

    High density circuits with posts that protrude beyond one surface of a substrate to provide easy mounting of devices such as integrated circuits. The posts also provide stress relief to accommodate differential thermal expansion. The process allows high interconnect density with fewer alignment restrictions and less wasted circuit area than previous processes. The resulting substrates can be test platforms for die testing and for multi-chip module substrate testing. The test platform can contain active components and emulate realistic operational conditions, replacing shorts/opens net testing.

  12. High density electronic circuit and process for making

    DOE Patents [OSTI]

    Morgan, W.P.

    1999-06-29T23:59:59.000Z

    High density circuits with posts that protrude beyond one surface of a substrate to provide easy mounting of devices such as integrated circuits are disclosed. The posts also provide stress relief to accommodate differential thermal expansion. The process allows high interconnect density with fewer alignment restrictions and less wasted circuit area than previous processes. The resulting substrates can be test platforms for die testing and for multi-chip module substrate testing. The test platform can contain active components and emulate realistic operational conditions, replacing shorts/opens net testing. 8 figs.

  13. Inferring population history from genealogies 

    E-Print Network [OSTI]

    Lohse, Konrad R.

    2010-01-01T23:59:59.000Z

    This thesis investigates a range of genealogical approaches to making quantitative inferences about the spatial and demographic history of populations with application to two insect systems: A local radiation of high ...

  14. Population modeling using harpacticoid copepods

    E-Print Network [OSTI]

    , communities and ecosystems. Environmental management decisions rely on ERAs, which and Amphiascus tenuiremis, and demographic equations were used to calculate population statistical power for reproductive endpoints, but at high labor and cost. Therefore

  15. Affine maps of density matrices

    E-Print Network [OSTI]

    Thomas F. Jordan

    2004-11-21T23:59:59.000Z

    For quantum systems described by finite matrices, linear and affine maps of matrices are shown to provide equivalent descriptions of evolution of density matrices for a subsystem caused by unitary Hamiltonian evolution in a larger system; an affine map can be replaced by a linear map, and a linear map can be replaced by an affine map. There may be significant advantage in using an affine map. The linear map is generally not completely positive, but the linear part of an equivalent affine map can be chosen to be completely positive and related in the simplest possible way to the unitary Hamiltonian evolution in the larger system.

  16. Rock Density | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-f < RAPID‎ |Rippey Jump to: navigation, searchRobbinsDensity At

  17. active populations based: Topics by E-print Network

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

    behaviors, such as chemical diffusiondetection, motility, proliferation, adhesion and life cycle stages. In this paper we extend the model to simulate heterotypic cell sorting....

  18. Application of Density Analysis for Landmine Risk Aura Cecilia Alegra#*1

    E-Print Network [OSTI]

    Libre de Bruxelles, Université

    of a Pilot Project for Landmine Impact Survey in Colombia. The study also gathered population data as well (GIS) and spatial statistic tools. Geocoded landmine incident data was gathered within the framework Ripley's K statistics, and local analysis, using both, Nearest Neighbors Hierarchical and Kernel Density

  19. Effect of plant populations and row spacings on plant and ear characters and grain yield of corn hybrids 

    E-Print Network [OSTI]

    Silapapun, Anek

    1976-01-01T23:59:59.000Z

    break- age and barren stalks increased with increase in population densities. Allessi and Power (2) also found that number of barren stalks increased and ear weight decreased with increased plant population. Bleasdale (7) proposed that if a crop...EFFECT OF PLANT POPULATIONS AND ROW SPACINGS ON PLANT AND EAR CHARACTERS AND GRAIN YIELD OF CORN HYBRIDS A Thesis by ANEK SILAPAPUN Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement...

  20. Multiscale modeling of oscillations and spiral waves in Dictyostelium populations

    E-Print Network [OSTI]

    Javad Noorbakhsh; David Schwab; Allyson Sgro; Thomas Gregor; Pankaj Mehta

    2014-09-12T23:59:59.000Z

    Unicellular organisms exhibit elaborate collective behaviors in response to environmental cues. These behaviors are controlled by complex biochemical networks within individual cells and coordinated through cell-to-cell communication. Describing these behaviors requires new mathematical models that can bridge scales -- from biochemical networks within individual cells to spatially structured cellular populations. Here, we present a family of multiscale models for the emergence of spiral waves in the social amoeba Dictyostelium discoideum. Our models exploit new experimental advances that allow for the direct measurement and manipulation of the small signaling molecule cAMP used by Dictyostelium cells to coordinate behavior in cellular populations. Inspired by recent experiments, we model the Dictyostelium signaling network as an excitable system coupled to various pre-processing modules. We use this family of models to study spatially unstructured populations by constructing phase diagrams that relate the properties of population-level oscillations to parameters in the underlying biochemical network. We then extend our models to include spatial structure and show how they naturally give rise to spiral waves. Our models exhibit a wide range of novel phenomena including a density dependent frequency change, bistability, and dynamic death due to slow cAMP dynamics. Our modeling approach provides a powerful tool for bridging scales in modeling of Dictyostelium populations.

  1. The Effect of Environmental Contaminants on Mating Dynamics and Population Viability in a Sex-Role-Reversed Pipefish

    E-Print Network [OSTI]

    Partridge, Charlyn G.

    2010-07-14T23:59:59.000Z

    Understanding how anthropogenic activity impacts the health and viability of wildlife populations is one of the most important tasks of environmental biology. A key concern related to bi-products of human activity is the accumulation...

  2. Cardiovascular disease, diabetes and established risk factors among populations of sub-Saharan African descent in Europe: a literature review

    E-Print Network [OSTI]

    Agyemang, Charles; Addo, Juliet; Bhopal, Raj; de-Graft Aikins, Ama; Stronks, Karien

    2009-08-11T23:59:59.000Z

    . Dutch African-Suriname men and women are less physically active than the White-Dutch whereas British African women are more physically active than women in the general population. Literature on psychosocial stress shows inconsistent results. Conclusion...

  3. High density behaviour of nuclear symmetry energy

    E-Print Network [OSTI]

    D. N. Basu; Tapan Mukhopadhyay

    2006-12-27T23:59:59.000Z

    Role of the isospin asymmetry in nuclei and neutron stars, with an emphasis on the density dependence of the nuclear symmetry energy, is discussed. The symmetry energy is obtained using the isoscalar as well as isovector components of the density dependent M3Y effective interaction. The constants of density dependence of the effective interaction are obtained by reproducing the saturation energy per nucleon and the saturation density of spin and isospin symmetric cold infinite nuclear matter. Implications for the density dependence of the symmetry energy in case of a neutron star are discussed, and also possible constraints on the density dependence obtained from finite nuclei are compared.

  4. Wind: wind power density GIS data at 50m above ground and 1km...

    Open Energy Info (EERE)

    GIS ... Dataset Activity Stream Wind: wind power density GIS data at 50m above ground and 1km resolution for Ghana from NREL (Abstract):  Raster GIS data, exported as BIL...

  5. Oxides having high energy densities

    DOE Patents [OSTI]

    Ceder, Gerbrand; Kang, Kisuk

    2013-09-10T23:59:59.000Z

    Certain disclosed embodiments generally relate to oxide materials having relatively high energy and/or power densities. Various aspects of the embodiments are directed to oxide materials having a structure B.sub.i(M.sub.jY.sub.k)O.sub.2, for example, a structure Li.sub.j(Ni.sub.jY.sub.k)O.sub.2 such as Li(Ni.sub.0.5Mn.sub.0.5)O.sub.2. In this structure, Y represents one or more atoms, each independently selected from the group consisting of alkaline earth metals, transition metals, Group 14 elements, Group 15, or Group 16 elements. In some embodiments, such an oxide material may have an O3 crystal structure, and/or a layered structure such that the oxide comprises a plurality of first, repeating atomic planes comprising Li, and a plurality of second, repeating atomic planes comprising Ni and/or Y.

  6. Quantum critical benchmark for density functional theory

    E-Print Network [OSTI]

    Paul E. Grabowski; Kieron Burke

    2014-08-09T23:59:59.000Z

    Two electrons at the threshold of ionization represent a severe test case for electronic structure theory. A pseudospectral method yields a very accurate density of the two-electron ion with nuclear charge close to the critical value. Highly accurate energy components and potentials of Kohn-Sham density functional theory are given, as well as a useful parametrization of the critical density. The challenges for density functional approximations and the strength of correlation are also discussed.

  7. Lipoprotein subclass analysis by immunospecific density

    E-Print Network [OSTI]

    Lester, Sandy Marie

    2009-05-15T23:59:59.000Z

    to obtain a lipoprotein density profile in the absence and presence of apo C-1. Density Lipoprotein Profiling (DLP) gives relevant information of lipoproteins, such as density and subclass characterization, and is a novel approach to purify apo C-1-enriched...

  8. Ultimate Energy Densities for Electromagnetic Pulses

    E-Print Network [OSTI]

    Mankei Tsang

    2008-03-06T23:59:59.000Z

    The ultimate electric and magnetic energy densities that can be attained by bandlimited electromagnetic pulses in free space are calculated using an ab initio quantized treatment, and the quantum states of electromagnetic fields that achieve the ultimate energy densities are derived. The ultimate energy densities also provide an experimentally accessible metric for the degree of localization of polychromatic photons.

  9. Jacek Dobaczewski Density functional theory and energy

    E-Print Network [OSTI]

    Dobaczewski, Jacek

    in Poland per voivodship Energy density functional 245 647 Price voivodship functional 654 763 295 580Jacek Dobaczewski Density functional theory and energy density functionals in nuclear physics Jacek://www.fuw.edu.pl/~dobaczew/Stellenbosch/dobaczewski_lecture.pdf Home page: http://www.fuw.edu.pl/~dobaczew/ #12;Jacek Dobaczewski Nuclear Structure Energy scales

  10. Gas Density and the Volume Schmidt Law for Spiral Galaxies

    E-Print Network [OSTI]

    O. V. Abramova; A. V. Zasov

    2007-10-01T23:59:59.000Z

    The thickness of the equilibrium isothermal gaseous layers and their volume densities \\rho_{gas}(R) in the disc midplane are calculated for 7 spiral galaxies (including our Galaxy) in the frame of self-consistent axisymmetric model. Local velocity dispersions of stellar discs were assumed to be close to marginal values necessary for the discs to be in a stable equilibrium state. Under this condition the stellar discs of at least 5 of 7 galaxies reveal a flaring. Their volume densities decrease with R faster than \\rho_{gas}, and, as a result, the gas dominates by the density at the disc periphery. Comparison of the azimuthally averaged star formation rate SFR with the gas density shows that there is no universal Schmidt law SFR \\rho_{gas}^n, common to all galaxies. Nevertheless, SFR in different galaxies reveals better correlation with the volume gas density than with the column one. Parameter n in the Schmidt law SFR \\rho_{gas}^n, formally calculated by the least square method, lies within 0.8-2.4 range and it's mean value is close to 1.5. Values of n calculated for molecular gas only are characterized by large dispersion, but their mean value is close to 1. Hence the smaller \\rho_{gas} the less is a fraction of gas actively taking part in the process of star formation.

  11. The Critical Density and the Effective Excitation Density of Commonly Observed Molecular Dense Gas Tracers

    E-Print Network [OSTI]

    Shirley, Yancy L

    2015-01-01T23:59:59.000Z

    The optically thin critical densities and the effective excitation densities to produce a 1 K km/s (or 0.818 Jy km/s $(\\frac{\

  12. Brain covariance selection: better individual functional connectivity models using population prior

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Brain covariance selection: better individual functional connectivity models using population prior bertrand.thirion@inria.fr Abstract Spontaneous brain activity, as observed in functional neuroimaging, has been shown to display reproducible structure that expresses brain architecture and car- ries markers

  13. Signatures of Dark Matter Halo Expansion in Galaxy Populations

    E-Print Network [OSTI]

    Brook, Chris B

    2015-01-01T23:59:59.000Z

    Dark matter cores within galaxy haloes can be formed by energy feedback from star forming regions: an energy balance suggests that the maximum core formation efficiency arises in galaxies with M$_{\\star}\\sim10^{8.5}$M$_{\\odot}$. We show that a model population of galaxies, in which the density profile has been modified by such baryonic feedback, is able to explain the observed galaxy velocity function and Tully-Fisher relations significantly better than a model in which a universal cuspy density profile is assumed. Alternative models, namely warm or self-interacting dark matter, also provide a better match to these observed relations than a universal profile model does, but make different predictions for how halo density profiles vary with mass compared to the baryonic feedback case. We propose that different core formation mechanisms may be distinguished based on the imprint they leave on galaxy populations over a wide range of mass. Within the current observational data we find evidence of the expected sign...

  14. EO 12898: Environmental Justice in Minority Populations and Low...

    Office of Environmental Management (EM)

    EO 12898: Environmental Justice in Minority Populations and Low-Income Populations EO 12898: Environmental Justice in Minority Populations and Low-Income Populations To focus...

  15. Aerodynamic Focusing Of High-Density Aerosols

    SciTech Connect (OSTI)

    Ruiz, D. E.; Fisch, Nathaniel

    2014-02-24T23:59:59.000Z

    High-density micron-sized particle aerosols might form the basis for a number of applications in which a material target with a particular shape might be quickly ionized to form a cylindrical or sheet shaped plasma. A simple experimental device was built in order to study the properties of high-density aerosol focusing for 1#22; m silica spheres. Preliminary results recover previous findings on aerodynamic focusing at low densities. At higher densities, it is demonstrated that the focusing properties change in a way which is consistent with a density dependent Stokes number.

  16. Statistical density modification using local pattern matching

    SciTech Connect (OSTI)

    Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Mail Stop M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2003-10-01T23:59:59.000Z

    Statistical density modification can make use of local patterns of density found in protein structures to improve crystallographic phases. A method for improving crystallographic phases is presented that is based on the preferential occurrence of certain local patterns of electron density in macromolecular electron-density maps. The method focuses on the relationship between the value of electron density at a point in the map and the pattern of density surrounding this point. Patterns of density that can be superimposed by rotation about the central point are considered equivalent. Standard templates are created from experimental or model electron-density maps by clustering and averaging local patterns of electron density. The clustering is based on correlation coefficients after rotation to maximize the correlation. Experimental or model maps are also used to create histograms relating the value of electron density at the central point to the correlation coefficient of the density surrounding this point with each member of the set of standard patterns. These histograms are then used to estimate the electron density at each point in a new experimental electron-density map using the pattern of electron density at points surrounding that point and the correlation coefficient of this density to each of the set of standard templates, again after rotation to maximize the correlation. The method is strengthened by excluding any information from the point in question from both the templates and the local pattern of density in the calculation. A function based on the origin of the Patterson function is used to remove information about the electron density at the point in question from nearby electron density. This allows an estimation of the electron density at each point in a map, using only information from other points in the process. The resulting estimates of electron density are shown to have errors that are nearly independent of the errors in the original map using model data and templates calculated at a resolution of 2.6 Å. Owing to this independence of errors, information from the new map can be combined in a simple fashion with information from the original map to create an improved map. An iterative phase-improvement process using this approach and other applications of the image-reconstruction method are described and applied to experimental data at resolutions ranging from 2.4 to 2.8 Å.

  17. A Population Model for the Academic Ecosystem

    E-Print Network [OSTI]

    Wu, Yan; Chiu, Dah Ming

    2015-01-01T23:59:59.000Z

    In recent times, the academic ecosystem has seen a tremendous growth in number of authors and publications. While most temporal studies in this area focus on evolution of co-author and citation network structure, this systemic inflation has received very little attention. In this paper, we address this issue by proposing a population model for academia, derived from publication records in the Computer Science domain. We use a generalized branching process as an overarching framework, which enables us to describe the evolution and composition of the research community in a systematic manner. Further, the observed patterns allow us to shed light on researchers' lifecycle encompassing arrival, academic life expectancy, activity, productivity and offspring distribution in the ecosystem. We believe such a study will help develop better bibliometric indices which account for the inflation, and also provide insights into sustainable and efficient resource management for academia.

  18. Population Ecology ISSN 1438-3896

    E-Print Network [OSTI]

    de Aguiar, Marcus A. M.

    1 23 Population Ecology ISSN 1438-3896 Popul Ecol DOI 10.1007/s10144-012-0352-3 Impacts of enemy of Population Ecology and Springer Japan. This e-offprint is for personal use only and shall not be self of Population Ecology and Springer Japan 2012 Abstract In this study, we used data from both experi- ments

  19. The blue plume population in dwarf spheroidal galaxies: genuine blue stragglers or young stellar population?

    E-Print Network [OSTI]

    Y. Momany; E. V. Held; I. Saviane; S. Zaggia; L. Rizzi; M. Gullieuszik

    2007-04-11T23:59:59.000Z

    Abridged... Blue stragglers (BSS) are thought to be the product of either primordial or collisional binary systems. In the context of dwarf spheroidal galaxies it is hard to firmly disentangle a genuine BSS population from young main sequence (MS) stars tracing a ~1-2 Gyr old star forming episode. Assuming that their blue plume populations are made of BSS, we estimate the BSS frequency for 8 Local Group non star-forming dwarf galaxies, using a compilation of ground and space based photometry. Our results can be summarized as follows: (i) The BSS frequency in dwarf galaxies, at any given Mv, is always higher than that in globular clusters of similar luminosities; (ii) the BSS frequency for the lowest luminosity dwarf galaxies is in excellent agreement with that observed in the Milky Way halo; and most interestingly (iii) derive a statistically significant anti-correlation between the BSS frequency and the galaxy Mv. The low density, almost collision-less, environments of our dwarf galaxy sample allow us to infer (i) their very low dynamical evolution; (ii) a negligible production of collisional BSS; and consequently (iii) that their blue plumes are mainly made of primordial binaries. The dwarf galaxies anti-correlation can be used as a discriminator: galaxies obeying the anti-correlation are more likely to possess genuine primordial BSS rather than young main sequence stars.

  20. Population Displacements Associated with Environmentally

    E-Print Network [OSTI]

    Columbia University

    Socio economic Impacts Enviro Impacts Dam Climate Change Fresh H20 Salinization Drought Flood infrastructure Climate Impact(s) Infrastructure development objectives Socio economic Impacts Enviro Impacts ­ Environmental impacts of major infrastructure projects 2 P l i di l i d i h l i f2. Population displacements

  1. The stellar population of bulges

    E-Print Network [OSTI]

    P. Jablonka

    2007-01-07T23:59:59.000Z

    This review summarizes the properties of the stellar population in bulges as observed in nearby or distant spiral galaxies. It gives a particular emphasis to the comparison with elliptical galaxies, when possible. The criteria of sample selection and choices in data analysis are addressed when they may be involved in discrepant results reached by different studies.

  2. The Evolution of Stellar Populations

    E-Print Network [OSTI]

    Angeles Diaz; Eduardo Hardy

    2001-03-14T23:59:59.000Z

    We summarize the discussion section on ``Evolution of Stellar Populations'' we led on May 27, 2000 in Granada, Spain, as part of the Euroconference on The Evolution of Galaxies. I- Observational Clues. We also provide a partial comparison between the present knowledge of these topics and that which existed at the time of the Crete Conference of 1995.

  3. Local and Global Radiative Feedback from Population III Star Formation

    E-Print Network [OSTI]

    O'Shea, Brian W

    2010-01-01T23:59:59.000Z

    We present an overview of recent work that focuses on understanding the radiative feedback processes that are potentially important during Population III star formation. Specifically, we examine the effect of the Lyman-Werner (photodissociating) background on the early stages of primordial star formation, which serves to delay the onset of star formation in a given halo but never suppresses it entirely. We also examine the effect that both photodissociating and ionizing radiation in I-fronts from nearby stellar systems have on the formation of primordial protostellar clouds. Depending on the strength of the incoming radiation field and the central density of the halos, Pop III star formation can be suppressed, unaffected, or even enhanced. Understanding these and other effects is crucial to modeling Population III star formation and to building the earliest generations of galaxies in the Universe.

  4. The Formation of Population III Binaries

    E-Print Network [OSTI]

    Saigo, K; Umemura, M; Saigo, Kazuya; Matsumoto, Tomoaki; Umemura, Masayuki

    2004-01-01T23:59:59.000Z

    We explore the possibility for the formation of Population III binaries. The collapse of a rotating cylinder is simulated with a three-dimensional, high-resolution nested grid, assuming the thermal history of primordial gas. The simulations are done with dimensionless units, and the results are applicable to low-mass as well as massive systems by scaling with the initial density. We find that if the initial angular momentum is as small as $\\beta \\approx 0.1$, where $\\beta$ is the ratio of centrifugal force to pressure force, then the runaway collapse of the cloud stops to form a rotationally-supported disk. After the accretion of the envelope, the disk undergoes a ring instability, eventually fragmenting into a binary. If the initial angular momentum is relatively large, a bar-type instability arises, resulting in the collapse into a single star through rapid angular momentum transfer. The present results show that a significant fraction of Pop III stars are expected to form in binary systems, even if they ar...

  5. Theory for planetary exospheres: II. Radiation pressure effect on exospheric density profiles

    E-Print Network [OSTI]

    Beth, Arnaud; Toublanc, Dominique; Dandouras, Iannis; Mazelle, Christian

    2015-01-01T23:59:59.000Z

    The planetary exospheres are poorly known in their outer parts, since the neutral densities are low compared with the instruments detection capabilities. The exospheric models are thus often the main source of information at such high altitudes. We present a new way to take into account analytically the additional effect of the radiation pressure on planetary exospheres. In a series of papers, we present with an Hamiltonian approach the effect of the radiation pressure on dynamical trajectories, density profiles and escaping thermal flux. Our work is a generalization of the study by Bishop and Chamberlain (1989). In this second part of our work, we present here the density profiles of atomic Hydrogen in planetary exospheres subject to the radiation pressure. We first provide the altitude profiles of ballistic particles (the dominant exospheric population in most cases), which exhibit strong asymmetries that explain the known geotail phenomenon at Earth. The radiation pressure strongly enhances the densities c...

  6. RECONSTRUCTING THE INITIAL DENSITY FIELD OF THE LOCAL UNIVERSE: METHODS AND TESTS WITH MOCK CATALOGS

    SciTech Connect (OSTI)

    Wang Huiyuan [Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Hefei, Anhui 230026 (China); Mo, H. J. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003-9305 (United States); Yang Xiaohu [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Shanghai 200030 (China); Van den Bosch, Frank C., E-mail: whywang@mail.ustc.edu.cn [Astronomy Department, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States)

    2013-07-20T23:59:59.000Z

    Our research objective in this paper is to reconstruct an initial linear density field, which follows the multivariate Gaussian distribution with variances given by the linear power spectrum of the current cold dark matter model and evolves through gravitational instabilities to the present-day density field in the local universe. For this purpose, we develop a Hamiltonian Markov Chain Monte Carlo method to obtain the linear density field from a posterior probability function that consists of two components: a prior of a Gaussian density field with a given linear spectrum and a likelihood term that is given by the current density field. The present-day density field can be reconstructed from galaxy groups using the method developed in Wang et al. Using a realistic mock Sloan Digital Sky Survey DR7, obtained by populating dark matter halos in the Millennium simulation (MS) with galaxies, we show that our method can effectively and accurately recover both the amplitudes and phases of the initial, linear density field. To examine the accuracy of our method, we use N-body simulations to evolve these reconstructed initial conditions to the present day. The resimulated density field thus obtained accurately matches the original density field of the MS in the density range 0.3{approx}<{rho}/ {rho}-bar {approx}<20 without any significant bias. In particular, the Fourier phases of the resimulated density fields are tightly correlated with those of the original simulation down to a scale corresponding to a wavenumber of {approx}1 h Mpc{sup -1}, much smaller than the translinear scale, which corresponds to a wavenumber of {approx}0.15 h Mpc{sup -1}.

  7. Quartz resonator fluid density and viscosity monitor

    DOE Patents [OSTI]

    Martin, Stephen J. (Albuquerque, NM); Wiczer, James J. (Albuquerque, NM); Cernosek, Richard W. (Albuquerque, NM); Frye, Gregory C. (Cedar Crest, NM); Gebert, Charles T. (Albuquerque, NM); Casaus, Leonard (Bernalillo, NM); Mitchell, Mary A. (Tijeras, NM)

    1998-01-01T23:59:59.000Z

    A pair of thickness-shear mode resonators, one smooth and one with a textured surface, allows fluid density and viscosity to be independently resolved. A textured surface, either randomly rough or regularly patterned, leads to trapping of liquid at the device surface. The synchronous motion of this trapped liquid with the oscillating device surface allows the device to weigh the liquid; this leads to an additional response that depends on liquid density. This additional response enables a pair of devices, one smooth and one textured, to independently resolve liquid density and viscosity; the difference in responses determines the density while the smooth device determines the density-viscosity product, and thus, the pair determines both density and viscosity.

  8. Method of synthesizing a low density material

    DOE Patents [OSTI]

    Lorensen, L.E.; Monaco, S.B.

    1987-02-27T23:59:59.000Z

    A novel method of synthesizing a polymeric material of low density of the order of 50mg/cc or less. Such a low density material has applications in many areas including laser target fabrication. The method comprises preparing a polymer blend of two incompatible polymers as a major and a minor phase by mixing them and extruding the mixture, and then selectively extracting the major component, to yield a fine, low density structure.

  9. Some recent efforts toward high density implosions

    SciTech Connect (OSTI)

    McClellan, G.E.

    1980-12-04T23:59:59.000Z

    Some recent Livermore efforts towards achieving high-density implosions are presented. The implosion dynamics necessary to compress DT fuel to 10 to 100 times liquid density are discussed. Methods of diagnosing the maximum DT density for a specific design are presented along with results to date. The dynamics of the double-shelled target with an exploding outer shell are described, and some preliminary experimental results are presented.

  10. Considering Air Density in Wind Power Production

    E-Print Network [OSTI]

    Zénó Farkas

    2011-03-11T23:59:59.000Z

    In the wind power production calculations the air density is usually considered as constant in time. Using the CIPM-2007 equation for the density of moist air as a function of air temperature, air pressure and relative humidity, we show that it is worth taking the variation of the air density into account, because higher accuracy can be obtained in the calculation of the power production for little effort.

  11. Considering Air Density in Wind Power Production

    E-Print Network [OSTI]

    Farkas, Zénó

    2011-01-01T23:59:59.000Z

    In the wind power production calculations the air density is usually considered as constant in time. Using the CIPM-2007 equation for the density of moist air as a function of air temperature, air pressure and relative humidity, we show that it is worth taking the variation of the air density into account, because higher accuracy can be obtained in the calculation of the power production for little effort.

  12. On the Extensive Air Shower density spectrum

    E-Print Network [OSTI]

    Aleksander Zawadzki; Tadeusz Wibig; Jerzy Gawin

    1998-07-29T23:59:59.000Z

    In search for new methods of determining the primary energy spectrum of Cosmic Rays, the attention was paid to the density spectrum measurement. New methods available at present warrant an accurateness of conclusions derived from the density spectrum measurements. The general statement about the change of the spectral index of the charged particle density spectrum is confirmed very clearly. Results concerning the shower size and primary energy spectra are also presented and discussed. Interesting future prospects for applications of the density spectrum method are proposed.

  13. Lipoprotein subclass analysis by immunospecific density 

    E-Print Network [OSTI]

    Lester, Sandy Marie

    2009-05-15T23:59:59.000Z

    ] 6 Table 1: Composition of Human Serum Lipoproteins Component Chylomicrons VLDL IDL LDL HDL Phospholipids (Weight %) 6-9 16-20 20-24 24-30 24-30 Free Cholesterol (Weight %) 1-3 4-8 8-9 9-12 2-5 Cholesteryl Esters (Weight %) 3-6 9... lipase; IDL, intermediate-density lipoprotein; LCAT, lecithin-cholesterol acyltransferase; LDL, low-density lipoprotein; LDL-R, low-density lipoprotein receptor; LDL-RRP, low-density lipoprotein receptor-related protein; Lyso PC...

  14. 3-D capacitance density imaging system

    DOE Patents [OSTI]

    Fasching, G.E.

    1988-03-18T23:59:59.000Z

    A three-dimensional capacitance density imaging of a gasified bed or the like in a containment vessel is achieved using a plurality of electrodes provided circumferentially about the bed in levels and along the bed in channels. The electrodes are individually and selectively excited electrically at each level to produce a plurality of current flux field patterns generated in the bed at each level. The current flux field patterns are suitably sensed and a density pattern of the bed at each level determined. By combining the determined density patterns at each level, a three-dimensional density image of the bed is achieved. 7 figs.

  15. active snubber circuit: Topics by E-print Network

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

    Circuits Engineering Websites Summary: Transition Density, A New Measure of Activity in Digital Circuits Farid N. Najm Semiconductor Process & Design Center Texas Instruments...

  16. aerial density profiles: Topics by E-print Network

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

    present an analytic approach to predict gas density and temperature profiles in dark matter haloes. We assume that the gas density profile traces the dark matter density profile...

  17. Arthropod population and community dynamics in turfgrass

    E-Print Network [OSTI]

    Wang, Yong

    1998-01-01T23:59:59.000Z

    Non-target arthropod and nematode populations in ographics. fungal and nematode treated bermudagrass were contrasted with populations in a chlorpyrifos and an untreated control treatment. Fifty-five arthropod families or suborder, herein referred...

  18. High density laser-driven target

    DOE Patents [OSTI]

    Lindl, John D. (San Ramon, CA)

    1981-01-01T23:59:59.000Z

    A high density target for implosion by laser energy composed of a central quantity of fuel surrounded by a high-Z pusher shell with a low-Z ablator-pusher shell spaced therefrom forming a region filled with low-density material.

  19. Dworshak Reservoir Kokanee Population Monitoring, Annual Report 2001.

    SciTech Connect (OSTI)

    Maiolie, Melo; Stark, Eric

    2003-03-01T23:59:59.000Z

    Onsite testing of strobe lights was conducted to determine if they repelled kokanee Oncorhynchus nerka away from the turbine intakes at Dworshak Dam. We tested a set of nine strobe lights flashing at a rate of 360 flashes/min placed near the intake of a 90 mW turbine. A split-beam echo sounder was used to determine the effect of strobe light operation on fish density (thought to be mostly kokanee) in front of the turbine intakes. On five nights between December 2001 and January 2002, fish density averaged 110 fish/ha when no lights were flashing. Mean density dropped to 13 fish/ha when the strobe lights were turned on during five additional nights of sampling. This 88% decline in density was significant at the P = 0.009 level of significance based on a paired Student's t test. There appeared to be no tendency for fish to habituate to the lights during the night. Test results indicate that a single set of nine lights may be sufficient to repel kokanee from a turbine intake during the night. We also used split-beam hydroacoustics to monitor the kokanee population in Dworshak Reservoir during 2001. Estimated abundance of kokanee has continued to increase since the spring of 1996 when high entrainment losses occurred. Based on hydroacoustic surveys, we estimated 3,276,000 kokanee in Dworshak Reservoir in early July 2001. This included 2,069,000 age-0 kokanee (90% CI {+-} 16.4%), 801,000 age-1 kokanee (90% CI {+-} 17.8%), and 406,000 age-2 kokanee (90% CI {+-} 20.5%). Entrainment sampling was also conducted with split-beam hydroacoustics a minimum of one continuous 24 h period per month. The highest entrainment rates occurred at night with lower discharges and shallower intake depths. Fish movement patterns suggested that they swam 'at will' in front of the intakes and may have chosen to move into the turbine intakes. Based on monthly hydroacoustic sampling in the forebay, we found that kokanee density was low in July and August during a period of high discharge. However, kokanee density was high in late winter when discharge was also high, thus increasing the likelihood of entrainment. Counts of spawning kokanee in four tributary streams used as an index reached 6,079 fish. This spawner count appeared unusually low considering the high population estimate of kokanee in the reservoir and data collected in previous years.

  20. Neutral depletion and the helicon density limit

    SciTech Connect (OSTI)

    Magee, R. M.; Galante, M. E.; Carr, J. Jr.; Lusk, G.; McCarren, D. W.; Scime, E. E. [West Virginia University, Morgantown, West Virginia 26506 (United States)] [West Virginia University, Morgantown, West Virginia 26506 (United States)

    2013-12-15T23:59:59.000Z

    It is straightforward to create fully ionized plasmas with modest rf power in a helicon. It is difficult, however, to create plasmas with density >10{sup 20} m{sup ?3}, because neutral depletion leads to a lack of fuel. In order to address this density limit, we present fast (1 MHz), time-resolved measurements of the neutral density at and downstream from the rf antenna in krypton helicon plasmas. At the start of the discharge, the neutral density underneath the antenna is reduced to 1% of its initial value in 15 ?s. The ionization rate inferred from these data implies that the electron temperature near the antenna is much higher than the electron temperature measured downstream. Neutral density measurements made downstream from the antenna show much slower depletion, requiring 14 ms to decrease by a factor of 1/e. Furthermore, the downstream depletion appears to be due to neutral pumping rather than ionization.

  1. Density functional theory for carbon dioxide crystal

    SciTech Connect (OSTI)

    Chang, Yiwen; Mi, Jianguo, E-mail: mijg@mail.buct.edu.cn; Zhong, Chongli [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China)

    2014-05-28T23:59:59.000Z

    We present a density functional approach to describe the solid?liquid phase transition, interfacial and crystal structure, and properties of polyatomic CO{sub 2}. Unlike previous phase field crystal model or density functional theory, which are derived from the second order direct correlation function, the present density functional approach is based on the fundamental measure theory for hard-sphere repulsion in solid. More importantly, the contributions of enthalpic interactions due to the dispersive attractions and of entropic interactions arising from the molecular architecture are integrated in the density functional model. Using the theoretical model, the predicted liquid and solid densities of CO{sub 2} at equilibrium triple point are in good agreement with the experimental values. Based on the structure of crystal-liquid interfaces in different planes, the corresponding interfacial tensions are predicted. Their respective accuracies need to be tested.

  2. Stellar populations of bulges at low redshift

    E-Print Network [OSTI]

    Sanchez-Blazquez, Patricia

    2015-01-01T23:59:59.000Z

    This chapter summarizes our current understanding of the stellar population properties of bulges and outlines important future research directions.

  3. Bone mineral density and blood metals in premenopausal women

    SciTech Connect (OSTI)

    Pollack, A.Z., E-mail: pollacka@mail.nih.gov [Epidemiology Branch, Division of Epidemiology, Statistics, and Prevention Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD (United States); Mumford, S.L. [Epidemiology Branch, Division of Epidemiology, Statistics, and Prevention Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD (United States)] [Epidemiology Branch, Division of Epidemiology, Statistics, and Prevention Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD (United States); Wactawski-Wende, J. [Department of Social and Preventive Medicine, University at Buffalo, State University of New York, Buffalo, NY (United States)] [Department of Social and Preventive Medicine, University at Buffalo, State University of New York, Buffalo, NY (United States); Yeung, E.; Mendola, P.; Mattison, D.R.; Schisterman, E.F. [Epidemiology Branch, Division of Epidemiology, Statistics, and Prevention Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD (United States)] [Epidemiology Branch, Division of Epidemiology, Statistics, and Prevention Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD (United States)

    2013-01-15T23:59:59.000Z

    Exposure to metals, specifically cadmium, lead, and mercury, is widespread and is associated with reduced bone mineral density (BMD) in older populations, but the associations among premenopausal women are unclear. Therefore, we evaluated the relationship between these metals in blood and BMD (whole body, total hip, lumbar spine, and non-dominant wrist) quantified by dual energy X-ray absorptiometry in 248 premenopausal women, aged 18-44. Participants were of normal body mass index (mean BMI 24.1), young (mean age 27.4), 60% were white, 20% non-Hispanic black, 15% Asian, and 6% other race group, and were from the Buffalo, New York region. The median (interquartile range) level of cadmium was 0.30 {mu}g/l (0.19-0.43), of lead was 0.86 {mu}g/dl (0.68-1.20), and of mercury was 1.10 {mu}g/l (0.58-2.00). BMD was treated both as a continuous variable in linear regression and dichotomized at the 10th percentile for logistic regression analyses. Mercury was associated with reduced odds of decreased lumbar spine BMD (0.66, 95% confidence interval: 0.44, 0.99), but overall, metals at environmentally relevant levels of exposure were not associated with reduced BMD in this population of healthy, reproductive-aged women. Further research is needed to determine if the blood levels of cadmium, lead, and mercury in this population are sufficiently low that there is no substantive impact on bone, or if effects on bone can be expected only at older ages.

  4. Density equalizing map projections (cartograms) in public health applications

    SciTech Connect (OSTI)

    Merrill, D.W.

    1998-05-01T23:59:59.000Z

    In studying geographic disease distributions, one normally compares rates among arbitrarily defined geographic subareas (e.g. census tracts), thereby sacrificing some of the geographic detail of the original data. The sparser the data, the larger the subareas must be in order to calculate stable rates. This dilemma is avoided with the technique of Density Equalizing Map Projections (DEMP){copyright}. Boundaries of geographic subregions are adjusted to equalize population density over the entire study area. Case locations plotted on the transformed map should have a uniform distribution if the underlying disease risk is constant. On the transformed map, the statistical analysis of the observed distribution is greatly simplified. Even for sparse distributions, the statistical significance of a supposed disease cluster can be calculated with validity. The DEMP algorithm was applied to a data set previously analyzed with conventional techniques; namely, 401 childhood cancer cases in four counties of California. The distribution of cases on the transformed map was analyzed visually and statistically. To check the validity of the method, the identical analysis was performed on 401 artificial cases randomly generated under the assumption of uniform risk. No statistically significant evidence for geographic non-uniformity of rates was found, in agreement with the original analysis performed by the California Department of Health Services.

  5. Active, polymer-based composite material implementing simple shear

    E-Print Network [OSTI]

    Lee, Sang Jin

    2009-05-15T23:59:59.000Z

    A novel active material for controllable, high work density applications was designed, fabricated, analyzed, and tested. This active material uses a lens-shaped element to implement simple shear motion with gas pressure actuation. The lens element...

  6. Density Prediction of Uranium-6 Niobium Ingots

    SciTech Connect (OSTI)

    D.F.Teter; P.K. Tubesing; D.J.Thoma; E.J.Peterson

    2003-04-15T23:59:59.000Z

    The densities of uranium-6 niobium (U-Nb) alloys have been compiled from a variety of literature sources such as Y-12 and Rocky Flats datasheets. We also took advantage of the 42 well-pedigreed, homogeneous baseline U-Nb alloys produced under the Enhanced Surveillance Program for density measurements. Even though U-Nb alloys undergo two-phase transitions as the Nb content varies from 0 wt. % to 8 wt %, the theoretical and measured densities vary linearly with Nb content. Therefore, the effect of Nb content on the density was modeled with a linear regression. From this linear regression, a homogeneous ingot of U-6 wt.% Nb would have a density of 17.382 {+-} 0.040 g/cc (95% CI). However, ingots produced at Y-12 are not homogeneous with respect to the Nb content. Therefore, using the 95% confidence intervals, the density of a Y-12 produced ingot would vary from 17.310 {+-} 0.043 g/cc at the center to 17.432 {+-} 0.039 g/cc at the edge. Ingots with larger Nb inhomogeneities will also have larger variances in the density.

  7. Periodic subsystem density-functional theory

    SciTech Connect (OSTI)

    Genova, Alessandro; Pavanello, Michele, E-mail: m.pavanello@rutgers.edu [Department of Chemistry, Rutgers University, Newark, New Jersey 07102 (United States); Ceresoli, Davide [Department of Chemistry, Rutgers University, Newark, New Jersey 07102 (United States); CNR-ISTM, Institute of Molecular Sciences and Technologies, Milano (Italy)

    2014-11-07T23:59:59.000Z

    By partitioning the electron density into subsystem contributions, the Frozen Density Embedding (FDE) formulation of subsystem Density Functional Theory (DFT) has recently emerged as a powerful tool for reducing the computational scaling of Kohn–Sham DFT. To date, however, FDE has been employed to molecular systems only. Periodic systems, such as metals, semiconductors, and other crystalline solids have been outside the applicability of FDE, mostly because of the lack of a periodic FDE implementation. To fill this gap, in this work we aim at extending FDE to treat subsystems of molecular and periodic character. This goal is achieved by a dual approach. On one side, the development of a theoretical framework for periodic subsystem DFT. On the other, the realization of the method into a parallel computer code. We find that periodic FDE is capable of reproducing total electron densities and (to a lesser extent) also interaction energies of molecular systems weakly interacting with metallic surfaces. In the pilot calculations considered, we find that FDE fails in those cases where there is appreciable density overlap between the subsystems. Conversely, we find FDE to be in semiquantitative agreement with Kohn–Sham DFT when the inter-subsystem density overlap is low. We also conclude that to make FDE a suitable method for describing molecular adsorption at surfaces, kinetic energy density functionals that go beyond the GGA level must be employed.

  8. Instabilities in the Nuclear Energy Density Functional

    E-Print Network [OSTI]

    M. Kortelainen; T. Lesinski

    2010-02-05T23:59:59.000Z

    In the field of Energy Density Functionals (EDF) used in nuclear structure and dynamics, one of the unsolved issues is the stability of the functional. Numerical issues aside, some EDFs are unstable with respect to particular perturbations of the nuclear ground-state density. The aim of this contribution is to raise questions about the origin and nature of these instabilities, the techniques used to diagnose and prevent them, and the domain of density functions in which one should expect a nuclear EDF to be stable.

  9. The temperature dependence of equilibrium plasma density

    E-Print Network [OSTI]

    B. V. Vasiliev

    2002-03-17T23:59:59.000Z

    Temperature dependence of an electron-nuclear plasma equilibrium density is considered basing on known approaches, which are given in (1)(2). It is shown that at a very high temperature, which is characteristic for a star interior, the equilibrium plasma density is almost constant and equals approximately to $10^{25}$ particles per $cm^3$. At a relatively low temperature, which is characteristic for star surface, the equilibrium plasma density is in several orders lower and depends on temperature as $T^{3/2}$.

  10. Low density, resorcinol-formaldehyde aerogels

    DOE Patents [OSTI]

    Pekala, R.W.

    1988-05-26T23:59:59.000Z

    The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer ''clusters''. The covalent crosslinking of these ''clusters'' produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density less than or equal to100 mg/cc; cell size less than or equal to0.1 microns). The aerogels are transparent,dark red in color and consist of interconnected colloidal-like particles with diameters of about 100 A/degree/. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron. 1 fig., 1 tab.

  11. Low density, resorcinol-formaldehyde aerogels

    DOE Patents [OSTI]

    Pekala, R.W.

    1989-10-10T23:59:59.000Z

    The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer clusters. The covalent crosslinking of these clusters produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density [<=]100 mg/cc; cell size [<=]0.1 microns). The aerogels are transparent, dark red in color and consist of interconnected colloidal-like particles with diameters of about 100 [angstrom]. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron.

  12. Low density, resorcinol-formaldehyde aerogels

    SciTech Connect (OSTI)

    Pekala, Richard W. (Pleasant Hill, CA)

    1989-01-01T23:59:59.000Z

    The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer "clusters". The covalent crosslinking of these "clusters" produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density .ltoreq.100 mg/cc; cell size .ltoreq.0.1 microns). The aerogels are transparent, dark red in color and consist of interconnected colloidal-like particles with diameters of about 100 .ANG.. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron.

  13. Low density, resorcinol-formaldehyde aerogels

    DOE Patents [OSTI]

    Pekala, Richard W. (Pleasant Hill, CA)

    1991-01-01T23:59:59.000Z

    The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer "Clusters". The covalent crosslinking of these "clusters" produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density.ltoreq.100 mg/cc; cell size .ltoreq.0.1 microns). The aerogels are transparent, dark red in color and consist of interconnected colloidal-like particles with diameters of about 100.circle.. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron.

  14. Alpha track density using a semiconductor detector

    E-Print Network [OSTI]

    Hamilton, Ian Scott

    1993-01-01T23:59:59.000Z

    of factors including variation in the initial dielectric thickness, and other undefined parameters. In addition, the resultant radon concentration reading is dependent upon the calibration factor used to interpret the track density reading. Obtaining...

  15. Breast Density and Cancer | GE Global Research

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

    Breast Cancer Awareness Series: Understanding Breast Density Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click to share (Opens in...

  16. Magnetic fields and density functional theory

    SciTech Connect (OSTI)

    Salsbury Jr., Freddie

    1999-02-01T23:59:59.000Z

    A major focus of this dissertation is the development of functionals for the magnetic susceptibility and the chemical shielding within the context of magnetic field density functional theory (BDFT). These functionals depend on the electron density in the absence of the field, which is unlike any other treatment of these responses. There have been several advances made within this theory. The first of which is the development of local density functionals for chemical shieldings and magnetic susceptibilities. There are the first such functionals ever proposed. These parameters have been studied by constructing functionals for the current density and then using the Biot-Savart equations to obtain the responses. In order to examine the advantages and disadvantages of the local functionals, they were tested numerically on some small molecules.

  17. Density controlled carbon nanotube array electrodes

    DOE Patents [OSTI]

    Ren, Zhifeng F. (Newton, MA); Tu, Yi (Belmont, MA)

    2008-12-16T23:59:59.000Z

    CNT materials comprising aligned carbon nanotubes (CNTs) with pre-determined site densities, catalyst substrate materials for obtaining them and methods for forming aligned CNTs with controllable densities on such catalyst substrate materials are described. The fabrication of films comprising site-density controlled vertically aligned CNT arrays of the invention with variable field emission characteristics, whereby the field emission properties of the films are controlled by independently varying the length of CNTs in the aligned array within the film or by independently varying inter-tubule spacing of the CNTs within the array (site density) are disclosed. The fabrication of microelectrode arrays (MEAs) formed utilizing the carbon nanotube material of the invention is also described.

  18. Inverse diffusion from knowledge of power densities

    E-Print Network [OSTI]

    Bal, Guillaume; Monard, Francois; Triki, Faouzi

    2011-01-01T23:59:59.000Z

    This paper concerns the reconstruction of a diffusion coefficient in an elliptic equation from knowledge of several power densities. The power density is the product of the diffusion coefficient with the square of the modulus of the gradient of the elliptic solution. The derivation of such internal functionals comes from perturbing the medium of interest by acoustic (plane) waves, which results in small changes in the diffusion coefficient. After appropriate asymptotic expansions and (Fourier) transformation, this allow us to construct the power density of the equation point-wise inside the domain. Such a setting finds applications in ultrasound modulated electrical impedance tomography and ultrasound modulated optical tomography. We show that the diffusion coefficient can be uniquely and stably reconstructed from knowledge of a sufficient large number of power densities. Explicit expressions for the reconstruction of the diffusion coefficient are also provided. Such results hold for a large class of boundary...

  19. High density load bearing insulation peg

    DOE Patents [OSTI]

    Nowobilski, J.J.; Owens, W.J.

    1985-01-29T23:59:59.000Z

    A high density peg is disclosed which can support a large load and exhibits excellent thermal resistance produced by a method wherein the peg is made in compliance with specified conditions of time, temperature and pressure. 4 figs.

  20. Tweedie Family Densities: Methods of Evaluation

    E-Print Network [OSTI]

    Smyth, Gordon K.

    of Queensland, St Lucia, Q 4072, Australia. 2 University of Southern Queensland, Toowoomba, Q 4350, Australia. Tweedie family densities are characterised by power variance functions of the form V[µ] = µp , where p

  1. Shock compression of low-density foams

    SciTech Connect (OSTI)

    Holmes, N.C.

    1993-07-01T23:59:59.000Z

    Shock compression of very low density micro-cellular materials allows entirely new regimes of hot fluid states to be investigated experimentally. Using a two-stage light-gas gun to generate strong shocks, temperatures of several eV are readily achieved at densities of roughly 0.5--1 g/cm{sup 3} in large, uniform volumes. The conditions in these hot, expanded fluids are readily found using the Hugoniot jump conditions. We will briefly describe the basic methodology for sample preparation and experimental measurement of shock velocities. We present data for several materials over a range of initial densities. This paper will explore the applications of these methods for investigations of equations of state and phase diagrams, spectroscopy, and plasma physics. Finally, we discus the need for future work on these and related low-density materials.

  2. Abstract-In this study, imaging of electrical current density in conducting objects, which contain nuclear magnetic resonance

    E-Print Network [OSTI]

    Eyüboðlu, Murat

    nuclear magnetic resonance (NMR) active nuclei is planned using 0.15T Magnetic Resonance Imaging (MRI at each cycle within the object. The applied current pulse creates a measurable magnetic flux density. The component of magnetic flux density parallel to the main magnetic field accumulates an additional phase

  3. QCD Level Density from Maximum Entropy Method

    E-Print Network [OSTI]

    Shinji Ejiri; Tetsuo Hatsuda

    2005-09-24T23:59:59.000Z

    We propose a method to calculate the QCD level density directly from the thermodynamic quantities obtained by lattice QCD simulations with the use of the maximum entropy method (MEM). Understanding QCD thermodynamics from QCD spectral properties has its own importance. Also it has a close connection to phenomenological analyses of the lattice data as well as experimental data on the basis of hadronic resonances. Our feasibility study shows that the MEM can provide a useful tool to study QCD level density.

  4. Chapter 4: High-Density Regimes in the FTU

    SciTech Connect (OSTI)

    Frigione, D.; Pieroni, L.; Buratti, P.; Giovannozzi, E.; Romanelli, M.; Esposito, B.; Leigheb, M.; Gabellieri, L. [Associazione EURATOM-ENEA sulla fusione (Italy)

    2004-05-15T23:59:59.000Z

    High-density plasmas (n{sub o} {approx} 8 x 10{sup 20} m{sup -3}) achieving steady improved core-confinement have been obtained in the Frascati Tokamak Upgrade (FTU) up to the maximum nominal toroidal field (8 T) by deep multiple pellet injection. These plasmas exhibit also high purity, efficient electron-ion coupling, and peaked density profiles sustained for several energy confinement times. Neutron yields in excess of 1 x 10{sup 13} n/s are measured, consistent with the reduction of the ion transport to neoclassical levels. Improved performance is associated with sawtooth stabilization that occurs when the pellet penetrates close to the q = 1 surface. In this regime, impurity accumulation can be prevented if a slow sawtooth activity is maintained. Experiments aimed at obtaining radiation-improved modes at high field have also been carried out using neon injection. The observed increase of the average density, with respect to the reference discharge, is significantly larger than the contribution of Ne. The neutron yield increases also by a factor of 3 to 6, and the energy confinement time increases by a factor up to 1.4.

  5. Ligand identification using electron-density mapcorrelations

    SciTech Connect (OSTI)

    Terwilliger, Thomas C.; Adams, Paul D.; Moriarty, Nigel W.; Cohn,Judith D.

    2006-12-01T23:59:59.000Z

    A procedure for the identification of ligands bound incrystal structuresof macromolecules is described. Two characteristics ofthe density corresponding to a ligand are used in the identificationprocedure. One is the correlation of the ligand density with each of aset of test ligands after optimization of the fit of that ligand to thedensity. The other is the correlation of a fingerprint of the densitywith the fingerprint of model density for each possible ligand. Thefingerprints consist of an ordered list of correlations of each the testligands with the density. The two characteristics are scored using aZ-score approach in which the correlations are normalized to the mean andstandard deviation of correlations found for a variety of mismatchedligand-density pairs, so that the Z scores are related to the probabilityof observing a particular value of the correlation by chance. Theprocedure was tested with a set of 200 of the most commonly found ligandsin the Protein Data Bank, collectively representing 57 percent of allligands in the Protein Data Bank. Using a combination of these twocharacteristics of ligand density, ranked lists of ligand identificationswere made for representative (F-o-F-c) exp(i phi(c)) difference densityfrom entries in the Protein Data Bank. In 48 percent of the 200 cases,the correct ligand was at the top of the ranked list of ligands. Thisapproach may be useful in identification of unknown ligands in newmacromolecular structures as well as in the identification of whichligands in a mixture have bound to a macromolecule.

  6. Interesting features in the combined Galex and Sloan color diagrams of solar-like galactic populations

    SciTech Connect (OSTI)

    Smith, Myron A.; Shiao, Bernard [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Bianchi, Luciana, E-mail: myronmeister@gmail.com, E-mail: shiao@stsci.edu, E-mail: bianchi@pha.jhu.edu [Johns Hopkins University, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2014-06-01T23:59:59.000Z

    We report on intriguing photometric properties of Galactic stars observed in the Galaxy Evolution Explorer (GALEX) satellite's far-UV (FUV) and near-UV (NUV) bandpasses, as well as from the ground-based Sloan Digital Sky Survey (SDSS) and the Kepler Input Catalog. The first property is that the (FUV – NUV) color distribution of stars in the Kepler field consists of two well-separated peaks. A second and more perplexing property is that for stars with spectral types G or later the mean (FUV – NUV) color becomes much bluer, contrary to expectation. Investigating this tendency further, we found in two samples of mid-F through K type stars that 17%-22% of them exhibit FUV excesses relative to their NUV fluxes and spectral types. A correction for FUV incompleteness of the FUV magnitude-limited star sample brings this ratio to 14%-18%. Nearly the same fractions are also discovered among members of the Kepler Eclipsing Binary Catalog and in the published list of Kepler Objects of Interest. These UV-excess ('UVe') colors are confirmed by the negative UV continuum slopes in GALEX spectra of members of the population. The SDSS spectra of some UVe stars exhibit metallic line weakening, especially in the blue. This suggests an enhanced contribution of UV flux relative to photospheric flux of a solar-type single star. We consider the possibility that the UV excesses originate from various types of hot stars, including white dwarf DA and sdB stars, binaries, and strong chromosphere stars that are young or in active binaries. The space density of compact stars is too low to explain the observed frequency of the UVe stars. Our model atmosphere-derived simulations of colors for binaries with main-sequence pairs with a hot secondary demonstrate that the color loci conflict with the observed sequence. As a preferred alternative we are left with the active chromospheres explanation, whether in active close binaries or young single stars, despite the expected paucity of young, chromospherically active stars in the field. We also address a third perplexing color property, namely, the presence of a prominent island of 'UV red' stars surrounded by 'UV blue' stars in the diagnostic (NUV–g), (g – i) color diagram. We find that the subpopulation composing this island is mainly horizontal branch stars. These objects do not exhibit UV excesses and therefore have UV colors typical for their spectral types. This subpopulation appears 'red' in the UV only because the stars' colors are not pulled to the blue by the inclusion of UVe stars.

  7. Nuclear energy density optimization: Shell structure

    E-Print Network [OSTI]

    M. Kortelainen; J. McDonnell; W. Nazarewicz; E. Olsen; P. -G. Reinhard; J. Sarich; N. Schunck; S. M. Wild; D. Davesne; J. Erler; A. Pastore

    2014-04-28T23:59:59.000Z

    Nuclear density functional theory is the only microscopical theory that can be applied throughout the entire nuclear landscape. Its key ingredient is the energy density functional. In this work, we propose a new parameterization UNEDF2 of the Skyrme energy density functional. The functional optimization is carried out using the POUNDerS optimization algorithm within the framework of the Skyrme Hartree-Fock-Bogoliubov theory. Compared to the previous parameterization UNEDF1, restrictions on the tensor term of the energy density have been lifted, yielding a very general form of the energy density functional up to second order in derivatives of the one-body density matrix. In order to impose constraints on all the parameters of the functional, selected data on single-particle splittings in spherical doubly-magic nuclei have been included into the experimental dataset. The agreement with both bulk and spectroscopic nuclear properties achieved by the resulting UNEDF2 parameterization is comparable with UNEDF1. While there is a small improvement on single-particle spectra and binding energies of closed shell nuclei, the reproduction of fission barriers and fission isomer excitation energies has degraded. As compared to previous UNEDF parameterizations, the parameter confidence interval for UNEDF2 is narrower. In particular, our results overlap well with those obtained in previous systematic studies of the spin-orbit and tensor terms. UNEDF2 can be viewed as an all-around Skyrme EDF that performs reasonably well for both global nuclear properties and shell structure. However, after adding new data aiming to better constrain the nuclear functional, its quality has improved only marginally. These results suggest that the standard Skyrme energy density has reached its limits and significant changes to the form of the functional are needed.

  8. Stellar populations in bulges of spiral galaxies

    E-Print Network [OSTI]

    P. Jablonka

    1997-03-03T23:59:59.000Z

    We discuss the integrated properties of the stellar population in bulges along the Hubble sequence and new HST data for individual stars in the bulge of M31.

  9. X-ray populations in galaxies

    E-Print Network [OSTI]

    G. Fabbiano

    2005-11-09T23:59:59.000Z

    Today's sensistive, high resolution Chandra X-ray observations allow the study of many populations of X-ray sources. The traditional astronomical tools of photometric diagrams and luminosity functions are now applied to these populations, and provide the means for classifying the X-ray sources and probing their evolution. While overall stellar mass drives the amount of X-ray binaries in old stellar population, the amount of sources in star-forming galaxies is related to the star formation rate. Shart-lived, luminous, high mass binaries (HNXBs) dominate these young populations.

  10. Empirical Prediction Intervals for County Population Forecasts

    E-Print Network [OSTI]

    Rayer, Stefan; Smith, Stanley K.; Tayman, Jeff

    2009-01-01T23:59:59.000Z

    in the determination and prediction of population forecastperformance of empirical prediction intervals? Table 5 shows26, 163–184. Empirical Prediction Intervals for County

  11. Supernova rates and stellar populations

    E-Print Network [OSTI]

    F. Mannucci

    2007-08-03T23:59:59.000Z

    We discuss the results about the nature of type Ia Supernovae that can be derived by studying their rates in different stellar populations. While the evolution of SN photometry and spectra can constrain the explosion mechanism, the SN rate depends on the progenitor system. We review the current available data on rates as a function of parent galaxy color, morphology, star formation rate, radio luminosity and environment. By studying the variation of the rates with the color of the parent galaxy, a strong evidence was established that type Ia SNe come from both young and old stars. The dependence of the rates with the radio power of the parent galaxy is best reproduced by a bimodal distribution of delay time between the formation of the progenitor and its explosion as a SN. Cluster early-type galaxies show higher type Ia SN rate with respect to field galaxies, and this effect can be due either to traces of young stars or to differences in the delay time distribution.

  12. Electron density measurements in a pulse-repetitive microwave discharge in air

    SciTech Connect (OSTI)

    Nikolic, M.; Popovic, S.; Vuskovic, L. [Department of Physics, Center for Accelerator Science, Old Dominion University, Norfolk, Virginia 23529 (United States); Herring, G. C.; Exton, R. J. [NASA Langley Research Center, Hampton, Virginia 23681 (United States)

    2011-12-01T23:59:59.000Z

    We have developed a technique for absolute measurements of electron density in pulse-repetitive microwave discharges in air. The technique is based on the time-resolved absolute intensity of a nitrogen spectral band belonging to the Second Positive System, the kinetic model and the detailed particle balance of the N{sub 2}C{sup 3}{Pi}{sub u} ({nu} = 0) state. This new approach bridges the gap between two existing electron density measurement methods (Langmuir probe and Stark broadening). The electron density is obtained from the time-dependent rate equation for the population of N{sub 2}C{sup 3}{Pi}{sub u} ({nu} = 0) using recorded waveforms of the absolute C{sup 3}{Pi}{sub u}{yields}B{sup 3}{Pi}{sub g} (0-0) band intensity, the forward and reflected microwave power density. Measured electron density waveforms using numerical and approximated analytical methods are presented for the case of pulse repetitive planar surface microwave discharge at the aperture of a horn antenna covered with alumina ceramic plate. The discharge was generated in air at 11.8 Torr with a X-band microwave generator using 3.5 {mu}s microwave pulses at peak power of 210 kW. In this case, we were able to time resolve the electron density within a single 3.5 {mu}s pulse. We obtained (9.0 {+-} 0.6) x 10{sup 13} cm{sup -3} for the peak and (5.0 {+-} 0.6) x 10{sup 13} cm{sup -3} for the pulse-average electron density. The technique presents a convenient, non-intrusive diagnostic method for local, time-defined measurements of electron density in short duration discharges near atmospheric pressures.

  13. High power density solid oxide fuel cells

    SciTech Connect (OSTI)

    Pham, Ai Quoc; Glass, Robert S.

    2004-10-12T23:59:59.000Z

    A method for producing ultra-high power density solid oxide fuel cells (SOFCs). The method involves the formation of a multilayer structure cells wherein a buffer layer of doped-ceria is deposited intermediate a zirconia electrolyte and a cobalt iron based electrode using a colloidal spray deposition (CSD) technique. For example, a cobalt iron based cathode composed of (La,Sr)(Co,Fe)O (LSCF) may be deposited on a zirconia electrolyte via a buffer layer of doped-ceria deposited by the CSD technique. The thus formed SOFC have a power density of 1400 mW/cm.sup.2 at 600.degree. C. and 900 mW/cm.sup.2 at 700.degree. C. which constitutes a 2-3 times increased in power density over conventionally produced SOFCs.

  14. Statistical approach to nuclear level density

    SciTech Connect (OSTI)

    Sen'kov, R. A.; Horoi, M. [Department of Physics, Central Michigan University, Mount Pleasant, MI 48859 (United States); Zelevinsky, V. G. [Department of Physics and Astronomy and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States)

    2014-10-15T23:59:59.000Z

    We discuss the level density in a finite many-body system with strong interaction between the constituents. Our primary object of applications is the atomic nucleus but the same techniques can be applied to other mesoscopic systems. We calculate and compare nuclear level densities for given quantum numbers obtained by different methods, such as nuclear shell model (the most successful microscopic approach), our main instrument - moments method (statistical approach), and Fermi-gas model; the calculation with the moments method can use any shell-model Hamiltonian excluding the spurious states of the center-of-mass motion. Our goal is to investigate statistical properties of nuclear level density, define its phenomenological parameters, and offer an affordable and reliable way of calculation.

  15. Fabrication of low density ceramic material

    DOE Patents [OSTI]

    Meek, T.T.; Blake, R.D.; Sheinberg, H.

    1985-01-01T23:59:59.000Z

    A precursor mixture and a method of making a low-density ceramic structural material are disclosed. The precursor mixture includes hollow microballoons, typically made of glass, together with a cementing agent capable of being cured by microwave irradiation. A preferred cementing agent is liquid hydrated potassium silicate, which is mixed with the glass microballoons to form a slurry. Upon irradiation the potassium silicate is dehydrated to form a solid porous matrix in which the microballoons are evenly distributed. Ground glass or other filling agents may be included in the slurry to enhance the properties of the final product. Low-density structural ceramics having densities on the order of 0.1 to 0.3 are obtained.

  16. Assessment of lesser prairie-chicken lek density relative to landscape characteristics in Texas

    SciTech Connect (OSTI)

    Jennifer Timmer; Matthew Butler; Warren Ballard; Clint Boal; Heather Whitlaw

    2012-08-31T23:59:59.000Z

    My 2.5-yr Master'Â?s project accomplished the objectives of estimating lesser prairie-chicken (LPC) lek density and abundance in the Texas occupied range and modeling anthropogenic and landscape features associated with lek density by flying helicopter lek surveys for 2 field seasons and employing a line-transect distance sampling method. This project was important for several reasons. Firstly, wildlife managers and biologists have traditionally monitored LPC populations with road-based surveys that may result in biased estimates and do not provide access to privately-owned or remote property. From my aerial surveys and distance sampling, I was able to provide accurate density and abundance estimates, as well as new leks and I detected LPCs outside the occupied range. Secondly, recent research has indicated that energy development has the potential to impact LPCs through avoidance of tall structures, increased mortality from raptors perching on transmission lines, disturbance to nesting hens, and habitat loss/fragmentation. Given the potential wind energy development in the Texas Panhandle, spatial models of current anthropogenic and vegetative features (such as transmission lines, roads, and percent native grassland) influencing lek density were needed. This information provided wildlife managers and wind energy developers in Texas with guidelines for how change in landscape features could impact LPCs. Lastly, LPC populations have faced range-wide declines over the last century and they are currently listed as a candidate species under the Endangered Species Act. I was able to provide timely information on LPC populations in Texas that will be used during the listing process.

  17. Precise and Accurate Density Determination of Explosives Using Hydrostatic Weighing

    SciTech Connect (OSTI)

    B. Olinger

    2005-07-01T23:59:59.000Z

    Precise and accurate density determination requires weight measurements in air and water using sufficiently precise analytical balances, knowledge of the densities of air and water, knowledge of thermal expansions, availability of a density standard, and a method to estimate the time to achieve thermal equilibrium with water. Density distributions in pressed explosives are inferred from the densities of elements from a central slice.

  18. Perspective: The Climate-Population-Infrastructure Modeling and Simulation Fertile Area for New Research

    SciTech Connect (OSTI)

    Allen, Melissa R [ORNL; Fernandez, Steven J [ORNL; Walker, Kimberly A [ORNL; Fu, Joshua S [ORNL

    2014-01-01T23:59:59.000Z

    Managing the risks posed by climate change and extreme weather to energy production and delivery is a challenge to communities worldwide. As climate conditions change, populations will shift, and demand will re-locate; and networked infrastructures will evolve to accommodate new load centers, and, hopefully, minimize vulnerability to natural disaster. Climate effects such as sea level rise, increased frequency and intensity of natural disasters, force populations to move locations. Displaced population creates new demand for built infrastructure that in turn generates new economic activity that attracts new workers and associated households to the new locations. Infrastructures and their interdependencies will change in reaction to climate drivers as the networks expand into new population areas and as portions of the networks are abandoned as people leave. Thus, infrastructures will evolve to accommodate new load centers while some parts of the network are underused, and these changes will create emerging vulnerabilities. Forecasting the location of these vulnerabilities by combining climate predictions and agent based population movement models shows promise for defining these future population distributions and changes in coastal infrastructure configurations. By combining climate and weather data, engineering algorithms and social theory it has been only recently possible to examine electricity demand response to increased climactic temperatures, population relocation in response to extreme cyclonic events, consequent net population changes and new regional patterns in electricity demand. These emerging results suggest a research agenda of coupling these disparate modelling approaches to understand the implications of climate change for protecting the nation s critical infrastructure.

  19. Density matrix of black hole radiation

    E-Print Network [OSTI]

    Lasma Alberte; Ram Brustein; Andrei Khmelnitsky; A. J. M. Medved

    2015-02-09T23:59:59.000Z

    Hawking's model of black hole evaporation is not unitary and leads to a mixed density matrix for the emitted radiation, while the Page model describes a unitary evaporation process in which the density matrix evolves from an almost thermal state to a pure state. We compare a recently proposed model of semiclassical black hole evaporation to the two established models. In particular, we study the density matrix of the outgoing radiation and determine how the magnitude of the off-diagonal corrections differs for the three frameworks. For Hawking's model, we find power-law corrections to the two-point functions that induce exponentially suppressed corrections to the off-diagonal elements of the full density matrix. This verifies that the Hawking result is correct to all orders in perturbation theory and also allows one to express the full density matrix in terms of the single-particle density matrix. We then consider the semiclassical theory for which the corrections, being non-perturbative from an effective field-theory perspective, are much less suppressed and grow monotonically in time. In this case, the R\\'enyi entropy for the outgoing radiation is shown to grow linearly at early times; but this growth slows down and the entropy eventually starts to decrease at the Page time. In addition to comparing models, we emphasize the distinction between the state of the radiation emitted from a black hole, which is highly quantum, and that of the radiation emitted from a typical classical black body at the same temperature.

  20. Error Analysis in Nuclear Density Functional Theory

    E-Print Network [OSTI]

    Nicolas Schunck; Jordan D. McDonnell; Jason Sarich; Stefan M. Wild; Dave Higdon

    2014-07-11T23:59:59.000Z

    Nuclear density functional theory (DFT) is the only microscopic, global approach to the structure of atomic nuclei. It is used in numerous applications, from determining the limits of stability to gaining a deep understanding of the formation of elements in the universe or the mechanisms that power stars and reactors. The predictive power of the theory depends on the amount of physics embedded in the energy density functional as well as on efficient ways to determine a small number of free parameters and solve the DFT equations. In this article, we discuss the various sources of uncertainties and errors encountered in DFT and possible methods to quantify these uncertainties in a rigorous manner.

  1. Low density, microcellular foams, preparation, and articles

    DOE Patents [OSTI]

    Young, A.T.

    1982-03-03T23:59:59.000Z

    A microcellular low-density foam of poly(4-methyl-1-pentene) particularly useful for forming targets for inertial confinement fusion has been developed. Articles made from the foam have been machined to tolerances of 0.0001 inch, although the densities of the fragile foam are low (about 10 to about 100 mg/cc) and the cell sizes are small (about 10 to about 30 ..mu..m). Methods for forming the foam and articles are given. The yield strength of the foam of the invention is higher than was obtained in other structures of this same material.

  2. Low density, microcellular foams, preparation, and articles

    DOE Patents [OSTI]

    Young, Ainslie T. (Los Alamos, NM); Marsters, Robert G. (Jemez Springs, NM); Moreno, Dawn K. (Espanola, NM)

    1984-01-01T23:59:59.000Z

    A microcellular low density foam of poly(4-methyl-1-pentene) which is particularly useful for forming targets for inertial confinement fusion has been developed. Articles made from the foam have been machined to tolerances of 0.0001 inch, although the densities of the fragile foam are low (about 10 to about 100 mg/cc) and the cell sizes are small (about 10 to about 30 .mu.m). Methods for forming the foam and articles are given; and the yield strength of the foam of the invention is higher than was obtained in other structures of this same material.

  3. Configuration Interactions Constrained by Energy Density Functionals

    E-Print Network [OSTI]

    B. Alex Brown; Angelo Signoracci; Morten Hjorth-Jensen

    2010-09-24T23:59:59.000Z

    A new method for constructing a Hamiltonian for configuration interaction calculations with constraints to energies of spherical configurations obtained with energy-density-functional (EDF) methods is presented. This results in a unified model that reproduced the EDF binding-energy in the limit of single-Slater determinants, but can also be used for obtaining energy spectra and correlation energies with renormalized nucleon-nucleon interactions. The three-body and/or density-dependent terms that are necessary for good nuclear saturation properties are contained in the EDF. Applications to binding energies and spectra of nuclei in the region above 208Pb are given.

  4. Level densities of transitional Sm nuclei

    SciTech Connect (OSTI)

    Capote, R.; Ventura, A.; Cannata, F.; Quesada, J.M. [Nuclear Data Section, International Atomic Energy Agency, Vienna (Austria); Ente Nuove Tecnologie, Energia e Ambiente, and Istituto Nazionale di Fisica Nucleare, Bologna (Italy); Dipartimento di Fisica dell Universita and Istituto Nazionale di Fisica Nucleare, Bologna (Italy); Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla (Spain)

    2005-06-01T23:59:59.000Z

    Experimentally determined level densities of the transitional isotopes {sup 148,149,150,152}Sm at excitation energies below and around the neutron binding energy are compared with microcanonical calculations based on a Monte Carlo approach to noncollective level densities, folded with a collective enhancement estimated in the frame of the interacting boson model (IBM). The IBM parameters are adjusted so as to reproduce the low-lying discrete levels of both parities, with the exception of the odd-mass nucleus, {sup 149}Sm, where complete decoupling of the unpaired neutron from the core is assumed.

  5. Genetic Diversity and Population Structure of the Arabian Horse Populations from Syria and other Countries

    E-Print Network [OSTI]

    Khanshour, Anas M

    2013-07-05T23:59:59.000Z

    different populations of Arabians representing Middle Eastern and Western populations. The main two aims of this study were to provide the genetic diversity description of Arabians from different origins and to examine the traditional classification system...

  6. Sideband generation of transient lasing without population inversion

    E-Print Network [OSTI]

    Luqi Yuan; Da-Wei Wang; Christopher O'Brien; Anatoly A. Svidzinsky; Marlan O. Scully

    2014-08-21T23:59:59.000Z

    We suggest a method to generate coherent short pulses by generating a frequency comb using lasing without inversion in the transient regime. We use a universal method to study the propagation of a pulse in various spectral regions through an active medium that is strongly driven on a low-frequency transition on a time scale shorter than the decoherence time. The results show gain on the sidebands at different modes can be produced even if there is no initial population inversion prepared. Besides the production of ultra-short pulse this frequency comb may have applications towards making short-wavelength or Tera-hertz lasers.

  7. Reversing Wolbachia-based population replacement

    E-Print Network [OSTI]

    Dobson, Stephen L.

    Wolbachia bacteria as a vehicle for population replace- ment. Also discussed are strategies strategies and provide mechan- isms for the autonomous spread of desired transgenes into the targeted relative to the natural population [15­17]. Primary candidates for gene-drive strategies are autonomous

  8. Cancer Epidemiology Population Health Sciences 750

    E-Print Network [OSTI]

    Sheridan, Jennifer

    -01/5/11-1 Cancer Epidemiology Population Health Sciences 750 3 credits When: Spring 2011 (1 Audience: This course is intended for students in health-related disciplines interested in cancer etiology. the unequal burden of cancer among populations and variations across time and geography, 2. the distinctive

  9. Calculating Evolutionary Dynamics in Structured Populations

    E-Print Network [OSTI]

    Nowak, Martin A.

    Calculating Evolutionary Dynamics in Structured Populations Charles G. Nathanson1. , Corina E. Here we provide a general formula for calculating evolutionary dynamics in a wide class of structured) Calculating Evolutionary Dynamics in Structured Populations. PLoS Comput Biol 5(12): e1000615. doi:10

  10. Global Distribution and Density of Constructed Impervious Surfaces

    SciTech Connect (OSTI)

    Elvidge, Christopher D. [NOAA National Geophysical Data Center,; Tuttle, Benjamin T. [NOAA National Geophysical Data Center,; Sutton, Paul S. [University of Denver; Baugh, Kimberly E. [NOAA National Geophysical Data Center,; Howard, Ara T. [NOAA National Geophysical Data Center,; Milesi, Christina [Foundation of California State University, Monterey Bay, California.; Bhaduri, Budhendra L [ORNL; Nemani, Ramakrishna R [NASA Ames Research Center

    2007-01-01T23:59:59.000Z

    We present the first global inventory of the spatial distribution and density of constructed impervious surface area (ISA). Examples of ISA include roads, parking lots, buildings, driveways, sidewalks and other manmade surfaces. While high spatial resolution is required to observe these features, the product we made is at one km2 resolution and is based on two coarse resolution indicators of ISA. Inputs into the product include the brightness of satellite observed nighttime lights and population count. The reference data used in the calibration were derived from 30 meter resolution ISA estimates of the USA from the U.S. Geological Survey. Nominally the product is for the years 2000-01 since both the nighttime lights and reference data are from those two years. We found that 1.05% of the United States land area is impervious surface (83,337 km2) and 0.43 % of the world's land surface (579,703 km2) is constructed impervious surface. China has more ISA than any other country (87,182 km2), but has only 67 m2 of ISA per person, compared to 297 m2 per person in the USA. Hyrdologic and environmental impacts of ISA begin to be exhibited when the density of ISA reaches 10% of the land surface. An examination of the areas with 10% or more ISA in watersheds finds that with the exception of Europe, the majority of watershed areas have less than 0.4% of their area at or above the 10% ISA threshold. The authors believe the next step for improving the product is to include reference ISA data from many more areas around the world.

  11. Maps of current density using density-functional methods A. Soncini,1,a

    E-Print Network [OSTI]

    Helgaker, Trygve

    , University of Durham, South Road, Durham DH1 3LE, United Kingdom Received 22 May 2008; accepted 17 July 2008 are compared and integration of the current densities to yield shielding constants is performed. In general of induced current density in molecules. © 2008 American Institute of Physics. DOI: 10.1063/1.2969104 I

  12. On the Determination of the Mean Cosmic Matter Density and the Amplitude of Density Fluctuations

    E-Print Network [OSTI]

    Thomas H. Reiprich

    2002-07-02T23:59:59.000Z

    The cosmological implications from a new estimate of the local X-ray galaxy cluster abundance are summarized. The results are then compared to independent observations. It is suggested that `low' values for the mean cosmic matter density and the amplitude of mass density fluctuations currently do not appear unreasonable observationally.

  13. Population genomics20-02-2009 Antnio Rodrigues; Bruno Santos / 59 Population Genomics

    E-Print Network [OSTI]

    Goldschmidt, Christina

    Population genomics20-02-2009 António Rodrigues; Bruno Santos / 59 Population Genomics 1 António Rodrigues (PDBC 2008) Bruno Santos (PDBC 2008) #12;Population genomics20-02-2009 António Rodrigues; Bruno Santos / 59 Contents 2 2 1000 genome project 1 Motivation and Introduction New generation sequencing

  14. POPULATION ECOLOGY Population Dynamics of the Colorado Potato Beetle in an

    E-Print Network [OSTI]

    POPULATION ECOLOGY Population Dynamics of the Colorado Potato Beetle in an Agroecosystem with Tomatoes and Potatoes with Management Implications to Processing Tomatoes CHRIS L. HARDING,1 S. J Environ. Entomol. 31(6): 1110Ð1118 (2002) ABSTRACT We evaluated the population dynamics of Colorado potato

  15. High power density supercapacitors using locally aligned carbon nanotube electrodes

    E-Print Network [OSTI]

    Du, C S; Yeh, J; Pan, Ning

    2005-01-01T23:59:59.000Z

    4484/16/4/003 High power density supercapacitors usingproduced very high speci?c power density of about 30 kW kg ?manufacturing of high power density supercapacitors and

  16. High-power-density spot cooling using bulk thermoelectrics

    E-Print Network [OSTI]

    Zhang, Y; Shakouri, A; Zeng, G H

    2004-01-01T23:59:59.000Z

    model, the cooling power densities of the devices can alsothe cooling power densities 2–24 times. Experimentally, the14 4 OCTOBER 2004 High-power-density spot cooling using bulk

  17. Mechanical constraints enhance electrical energy densities of soft dielectrics

    E-Print Network [OSTI]

    Ferrari, Silvia

    Mechanical constraints enhance electrical energy densities of soft dielectrics Lin Zhang, Qiming, the dielectric will breakdown electrically. The breakdown limits the electrical energy density of the dielectric electric fields and thus increase their electrical energy densities. The mechanical constraints suppress

  18. Density waves in the Calogero model - revisited

    SciTech Connect (OSTI)

    Bardek, V. [Rudjer Boskovic Institute, Bijenicka c.54, HR-10002 Zagreb (Croatia)], E-mail: bardek@irb.hr; Feinberg, J. [Department of Physics, University of Haifa at Oranim, Tivon 36006 (Israel); Department of Physics, Technion-Israel Inst. of Technology, Haifa 32000 (Israel); KITP, University of California, Santa Barbara, CA 93106-4030 (United States)], E-mail: joshua@physics.technion.ac.il; Meljanac, S. [Rudjer Boskovic Institute, Bijenicka c.54, HR-10002 Zagreb (Croatia)], E-mail: meljanac@irb.hr

    2010-03-15T23:59:59.000Z

    The Calogero model bears, in the continuum limit, collective excitations in the form of density waves and solitary modulations of the density of particles. This sector of the spectrum of the model was investigated, mostly within the framework of collective-field theory, by several authors, over the past 15 years or so. In this work we shall concentrate on periodic solutions of the collective BPS-equation (also known as 'finite amplitude density waves'), as well as on periodic solutions of the full static variational equations which vanish periodically (also known as 'large amplitude density waves'). While these solutions are not new, we feel that our analysis and presentation add to the existing literature, as we explain in the text. In addition, we show that these solutions also occur in a certain two-family generalization of the Calogero model, at special points in parameter space. A compendium of useful identities associated with Hilbert transforms, including our own proofs of these identities, appears in Appendix A. In Appendix B we also elucidate in the present paper some fine points having to do with manipulating Hilbert-transforms, which appear ubiquitously in the collective field formalism. Finally, in order to make this paper self-contained, we briefly summarize in Appendix C basic facts about the collective field formulation of the Calogero model.

  19. Density-Functional Theory for Complex Fluids

    E-Print Network [OSTI]

    Wu, Jianzhong

    . This generic methodology is built upon a mathematical theorem that states, for an equilibrium system at a given modeling of the microscopic struc- tures and phase behavior of soft-condensed matter. The methodol- ogy to the one-body density profile Grand potential: the free energy of an open system at fixed volume

  20. Photovoltaic retinal prosthesis with high pixel density

    E-Print Network [OSTI]

    Palanker, Daniel

    Photovoltaic retinal prosthesis with high pixel density Keith Mathieson1,4 , James Loudin1 to stimulating electrodes via intraocular cables. We present a photovoltaic subretinal prosthesis, in which pixel, demonstrating the possibility of a fully integrated photovoltaic retinal prosthesis with high

  1. Methods to enhance blanket power density

    SciTech Connect (OSTI)

    Hsu, P.Y.; Miller, L.G.; Bohn, T.S.; Deis, G.A.; Longhurst, G.R.; Masson, L.S.; Wessol, D.E.; Abdou, M.A.

    1982-06-01T23:59:59.000Z

    The overall objective of this task is to investigate the extent to which the power density in the FED/INTOR breeder blanket test modules can be enhanced by artificial means. Assuming a viable approach can be developed, it will allow advanced reactor blanket modules to be tested on FED/INTOR under representative conditions.

  2. Durable high-density data storage

    SciTech Connect (OSTI)

    Stutz, R.A.; Lamartine, B.C.

    1996-09-01T23:59:59.000Z

    This paper will discuss the Focus Ion Beam (FIB) milling process, media life considerations, and methods of reading the micromilled data. The FIB process for data storage provides a new non-magnetic storage method for archiving large amounts of data. The process stores data on robust materials such as steel, silicon, and gold coated silicon. The storage process was developed to provide a method to insure the long term storage life of data. We estimate the useful life of data written on silicon or gold coated silicon to be a few thousand years. The process uses an ion beam to carve material from the surface much like stone cutting. The deeper information is carved into the media the longer the expected life of the information. The process can read information in three formats: (1) binary at densities of 3.5 Gbits/cm{sup 2}, (2) alphanumeric at optical or non-optical density, and (3) graphical at optical and non-optical density. The formats can be mixed on the same media; and thus it is possible to record, in a human readable format, instructions that can be read using an optical microscope. These instructions provide guidance on reading the higher density information.

  3. Density Functional Theory Models for Radiation Damage

    E-Print Network [OSTI]

    Density Functional Theory Models for Radiation Damage S.L. Dudarev EURATOM/CCFE Fusion Association and informative as the most advanced experimental techniques developed for the observation of radiation damage investigation and assessment of radiation damage effects, offering new insight into the origin of temperature

  4. High power density thermophotovoltaic energy conversion

    SciTech Connect (OSTI)

    Noreen, D.L. [R& D Technologies, Inc., Hoboken, New Jersey 07030 (United States); Du, H. [Department of Materials Science and Engineering, Stevens Institute of Technology, Hoboken, New Jersey 07030 (United States)

    1995-01-05T23:59:59.000Z

    R&D Technologies is developing thermophotovoltaic (TPV) technology based on the use of porous/fibrous ceramic broadband-type emitter designs that utilize recuperative or regenerative techniques to improve thermal efficiency and power density. This paper describes preliminary estimates of what will be required to accomplish sufficient power density to develop a practical, commercially-viable TPV generator. It addresses the needs for improved, thermal shock-resistant, long-life porous/fibrous ceramic emitters and provides information on the photocell technology required to achieve acceptable power density in broadband-type (with selective filter) TPV systems. TPV combustors/systems operating at a temperature of 1500 {degree}C with a broadband-type emitter is proposed as a viable starting point for cost-effective TPV conversion. Based on current projections for photocell cost, system power densities of 7.5--10 watts per square centimeter of emitter area will be required for TPV to become a commercially viable technology. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  5. Estimating density of Florida Key deer

    E-Print Network [OSTI]

    Roberts, Clay Walton

    2006-08-16T23:59:59.000Z

    for this species since 1968; however, a need to evaluate the precision of existing and alternative survey methods (i.e., road counts, mark-recapture, infrared-triggered cameras [ITC]) was desired by USFWS. I evaluated density estimates from unbaited ITCs and road...

  6. Effective Field Theory and Finite Density Systems

    E-Print Network [OSTI]

    R. J. Furnstahl; G. Rupak; T. Schaefer

    2008-01-04T23:59:59.000Z

    This review gives an overview of effective field theory (EFT) as applied at finite density, with a focus on nuclear many-body systems. Uniform systems with short-range interactions illustrate the ingredients and virtues of many-body EFT and then the varied frontiers of EFT for finite nuclei and nuclear matter are surveyed.

  7. Dynamic Evolution for Risk-Neutral Densities

    E-Print Network [OSTI]

    2008-10-27T23:59:59.000Z

    specifications of the data are as follows: the spot asset price is 590, the risk- free interest rate is ... than 10) the recovered risk-neutral densities exhibit less smoothness than in the cases .... Technical report, Purdue University, 1995. [31] A. M. ...

  8. INSIDE OUT AND UPSIDE DOWN: TRACING THE ASSEMBLY OF A SIMULATED DISK GALAXY USING MONO-AGE STELLAR POPULATIONS

    SciTech Connect (OSTI)

    Bird, Jonathan C.; Kazantzidis, Stelios; Weinberg, David H. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Guedes, Javiera [Institute for Astronomy, ETH Zuerich, Wolgang-Pauli-Strasse 27, CH-8093 Zuerich (Switzerland); Callegari, Simone [Anthropology Institute and Museum, University of Zuerich, Winterthurerstrasse 190, CH-8057 Zuerich (Switzerland); Mayer, Lucio [Institute for Theoretical Physics, University of Zuerich, Winterthurerstrasse 190, CH-8057 Zuerich (Switzerland); Madau, Piero [Department of Astronomy and Astrophysics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States)

    2013-08-10T23:59:59.000Z

    We analyze the present day structure and assembly history of a high-resolution hydrodynamic simulation of the formation of a Milky-Way-(MW)-like disk galaxy, from the ''Eris'' simulation suite, dissecting it into cohorts of stars formed at different epochs of cosmic history. At z = 0, stars with t{sub form} < 2 Gyr mainly occupy the stellar spheroid, with the oldest (earliest forming) stars having more centrally concentrated profiles. The younger age cohorts populate disks of progressively longer radial scale lengths and shorter vertical scale heights. At a given radius, the vertical density profiles and velocity dispersions of stars vary smoothly as a function of age, and the superposition of old, vertically extended and young, vertically compact cohorts gives rise to a double-exponential profile like that observed in the MW. Turning to formation history, we find that the trends of spatial structure and kinematics with stellar age are largely imprinted at birth, or immediately thereafter. Stars that form during the active merger phase at z > 3 are quickly scattered into rounded, kinematically hot configurations. The oldest disk cohorts form in structures that are radially compact and relatively thick, while subsequent cohorts form in progressively larger, thinner, colder configurations from gas with increasing levels of rotational support. The disk thus forms ''inside out'' in a radial sense and ''upside down'' in a vertical sense. Secular heating and radial migration influence the final state of each age cohort, but the changes they produce are small compared to the trends established at formation. The predicted correlations of stellar age with spatial and kinematic structure are in good qualitative agreement with the correlations observed for mono-abundance stellar populations in the MW.

  9. Graphene Nucleation Density on Copper: Fundamental Role of Background Pressure Ivan Vlassiouk,*

    E-Print Network [OSTI]

    Feenstra, Randall

    1 Graphene Nucleation Density on Copper: Fundamental Role of Background Pressure Ivan Vlassiouk the effect of background pressure and synthesis temperature on the graphene crystal sizes in chemical vapor of the background pressure and provide the activation energy for graphene nucleation in atmospheric pressure CVD (9

  10. Solar flux variability of Mars' exosphere densities and temperatures Jeffrey M. Forbes,1

    E-Print Network [OSTI]

    Forbes, Jeffrey

    Solar flux variability of Mars' exosphere densities and temperatures Jeffrey M. Forbes,1 Frank G, the response of Mars' exosphere to long-term solar change is established and compared to that of Earth conditions) change only 36­50% as much as those at Earth as solar activity increases from solar minimum

  11. Modelling Bulk Density According to Structure Development: Toward an Indicator of Microstructure Development in Ferralsols.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Modelling Bulk Density According to Structure Development: Toward an Indicator of Microstructure the microaggregates with a small contribution of large pores resulting from root development and macrofaunal activity.25 g cm-3 among the 108 samples studied. Visual assessment of BESI showed that soil material

  12. ?Linear Gas Jet with Tailored Density Profile"

    SciTech Connect (OSTI)

    KRISHNAN, Mahadevan

    2012-12-10T23:59:59.000Z

    Supersonic, highly collimated gas jets and gas-filled capillary discharge waveguides are two primary targets of choice for Laser Plasma Accelerators (LPA) . Present gas jets have lengths of only 2-4 mm at densities of 1-4E19 cm-3, sufficient for self trapping and electron acceleration to energies up to ~150 MeV. Capillary structures 3 cm long have been used to accelerate beams up to 1 GeV. Capillary discharges used in LPAs serve to guide the pump laser and optimize the energy gain. A wall-stabilized capillary discharge provides a transverse profile across the channel that helps guide the laser and combat diffraction. Gas injection via a fast nozzle at one end provides some longitudinal density control, to improve the coupling. Gas jets with uniform or controlled density profiles may be used to control electron bunch injection and are being integrated into capillary experiments to add tuning of density. The gas jet for electron injection has not yet been optimized. Our Ph-I results have provided the LPA community with an alternative path to realizing a 2-3GeV electron bunch using just a gas jet. For example, our slit/blade combination gives a 15-20mm long acceleration path with tunable density profile, serving as an alternative to a 20-mm long capillary discharge with gas injection at one end. In Ph-II, we will extend these results to longer nozzles, to see whether we can synthesize 30 or 40-mm long plasma channels for LPAs.

  13. Theoretical Electron Density Distributions for Fe- and Cu-Sulfide...

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

    Electron Density Distributions for Fe- and Cu-Sulfide Earth Materials: A Connection between Bond Length, Bond Theoretical Electron Density Distributions for Fe- and Cu-Sulfide...

  14. A Density Functional Theory Study of Formaldehyde Adsorption...

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

    Density Functional Theory Study of Formaldehyde Adsorption on Ceria. A Density Functional Theory Study of Formaldehyde Adsorption on Ceria. Abstract: Molecular adsorption of...

  15. Effects of van der Waals Density Functional Corrections on Trends...

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

    van der Waals Density Functional Corrections on Trends in Furfural Adsorption and Hydrogenation on Close-Packed Effects of van der Waals Density Functional Corrections on Trends in...

  16. Pauling bond strength, bond length and electron density distribution...

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

    Pauling bond strength, bond length and electron density distribution. Pauling bond strength, bond length and electron density distribution. Abstract: A power law regression...

  17. TEMPO-based Catholyte for High Energy Density Nonaqueous Redox...

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

    TEMPO-based Catholyte for High Energy Density Nonaqueous Redox Flow Batteries. TEMPO-based Catholyte for High Energy Density Nonaqueous Redox Flow Batteries. Abstract: We will...

  18. Using Radio Waves to Control Fusion Plasma Density

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

    Using Radio Waves to Control Fusion Plasma Density Using Radio Waves to Control Fusion Plasma Density Simulations Run at NERSC Support Fusion Experiments at MIT, General Atomics...

  19. High Energy Density Laboratory Plasmas Program | National Nuclear...

    National Nuclear Security Administration (NNSA)

    Photo Gallery Jobs Apply for Our Jobs Our Jobs Working at NNSA Blog Home High Energy Density Laboratory Plasmas Program High Energy Density Laboratory Plasmas Program...

  20. High power density supercapacitors using locally aligned carbon nanotube electrodes

    E-Print Network [OSTI]

    Du, C S; Yeh, J; Pan, Ning

    2005-01-01T23:59:59.000Z

    High power density supercapacitors using locally alignedof high power density supercapacitors and other similarcells [6], and for supercapacitors [7–18]. As unique energy

  1. Effects of Ambient Density and Temperature on Soot Formation...

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

    Density and Temperature on Soot Formation under High-EGR Conditions Effects of Ambient Density and Temperature on Soot Formation under High-EGR Conditions Presentation given at...

  2. Mitigating Breakdown in High Energy Density Perovskite Polymer...

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

    Mitigating Breakdown in High Energy Density Perovskite Polymer Nanocomposite Capacitors Mitigating Breakdown in High Energy Density Perovskite Polymer Nanocomposite Capacitors 2012...

  3. Design for a Longitudinal Density Monitor for the LHC

    SciTech Connect (OSTI)

    Jeff, Adam; /CERN; Bart Pedersen, Stephane; /CERN; Boccardi, Andrea; /CERN; Bravin, Enrico; /CERN; Lefevre, Thibaut; /CERN; Rabiller, Aurelie; /CERN; Roncarolo, Federico; /CERN; Fisher, Alan; /SLAC; Welsch, Carsten; /Liverpool U.

    2012-07-13T23:59:59.000Z

    Synchrotron radiation is currently used on the LHC for beam imaging and for monitoring the proton population in the 3 microsecond abort gap. In addition to these existing detectors, a study has been initiated to provide longitudinal density profiles of the LHC beams with a high dynamic range and a 50ps time resolution. This would allow for the precise measurement both of the bunch shape and the number of particles in the bunch tail or drifting into ghost bunches. A solution is proposed based on counting synchrotron light photons with two fast avalanche photo-diodes (APD) operated in Geiger mode. One is free-running but heavily attenuated and can be used to measure the core of the bunch. The other is much more sensitive, for measurement of the bunch tails, but must be gated off during the passage of the bunch to prevent the detector from being swamped. An algorithm is then applied to combine the two measurements and correct for the detector dead-time, afterpulsing and pile-up effects. Initial results from laboratory testing of this system are described here.

  4. Design for a Longitudinal Density Monitor for the LHC

    E-Print Network [OSTI]

    Bart Pedersen, S; Boccardi, A; Fisher, AS; Jeff, A; Lefevre, T; Rabiller, A; Roncarolo, F; Welsch, CP

    2010-01-01T23:59:59.000Z

    Synchrotron radiation is currently used on the LHC for beam imaging and for monitoring the proton population in the 3 microsecond abort gap. In addition to these existing detectors, a study has been initiated to provide longitudinal density profiles of the LHC beams with a high dynamic range and a 50ps time resolution. This would allow for the precise measurement both of the bunch shape and the number of particles in the bunch tail or drifting into ghost bunches. A solution is proposed based on counting synchrotron light photons with two fast avalanche photo-diodes (APD) operated in Geiger mode. One is free-running but heavily attenuated and can be used to measure the core of the bunch. The other is much more sensitive, for measurement of the bunch tails, but must be gated off during the passage of the bunch to prevent the detector from being swamped. An algorithm is then applied to combine the two measurements and correct for the detector dead-time, after pulsing and pileup effects. Initial results from labo...

  5. Hanford Area 1990 population and 50-year projections. [Appendix contains computer programming for population projections and graphs showing them by grid areas

    SciTech Connect (OSTI)

    Beck, D.M.; Scott, M.J.; Shindle, S.F.; Napier, B.A.; Thurman, A.G.; Batishko, N.C. (Pacific Northwest Lab., Richland, WA (United States)); Davis, M.D. (Westinghouse Hanford Co., Richland, WA (United States)); Pittenger, D.B. (Demographics Lab., Olympia, WA (United States))

    1991-10-01T23:59:59.000Z

    The complex and comprehensive safety analysis activities carried out at Hanford for nonreactor nuclear facilities require data from a number of scientific and engineering disciplines. The types of data that are required include data pertaining to current population and population projections. The types of data found in this document include 1990 census totals for residential population within a 50-mile radius of the 100-N, 200, 300, and 400 Area meteorological towers. This document also contains 50-year projections for residential populations within a 50-mile radius of these four meteorological towers. The analysis of population projections indicates that residential population within a 50-mile radius of the four meteorological towers in question will continue to grow through 2040, although at a slower rate each decade. In all cases, the highest growth is projected for the decade ending in the year 2000. The annual growth rate for this period is projected to be 0.646, 0.633, 0.543, and 0.570 in the 100-N, 200, 300, and 400 Areas, respectively. By 2040, these growth rates are projected to drop to 0.082, 0.068, 0.078, 0.078, respectively. 4 refs., 1 figs., 4 tabs.

  6. Population dynamics of the Concho water snake

    E-Print Network [OSTI]

    Mueller, James Michael

    1990-01-01T23:59:59.000Z

    on the Colorado River, Texas 24 14 Model A' estimates and standard errors for the 1987 age class of a Concho water snake population at the lower Elm Creek study site, near Ballinger, Texas. 25 15 Model A' estimates and standard errors for the 1988 age class... of a Concha water snake population at the lower Elm Creek study site, near Ballinger, Texas. 25 16 Jolly-Seber estimates and standard errors for the 1988 age class of a Concha water snake population at the upper Elm Creek study site, near Ballinger...

  7. Accounting for population variation in targeted proteomics

    SciTech Connect (OSTI)

    Fujimoto, Grant M.; Monroe, Matthew E.; Rodriguez, Larissa M.; Wu, Chaochao; MacLean, Brendan; Smith, Richard D.; MacCoss, Michael; Payne, Samuel H.

    2014-01-03T23:59:59.000Z

    Individual proteomes typically differ from the reference human proteome at ~10,000 single amino acid variants. When viewed at the population scale, this individual variation results in a wide variety of protein sequences. In targeted proteomics experiments, such variability would confound accurate protein quantification. To facilitate researchers in identifying target peptides with high variability within the human population we have created the Population Variation plug-in for Skyline, which provides easy access to the polymorphisms stored in dbSNP. Given a set of peptides, the tool reports minor allele frequency for common polymorphisms. We highlight the importance of considering genetic variation by applying the tool to public datasets.

  8. Hanford Site Regional Population - 2010 Census

    SciTech Connect (OSTI)

    Hamilton, Erin L.; Snyder, Sandra F.

    2011-08-12T23:59:59.000Z

    The U.S. Department of Energy conducts radiological operations in south-central Washington State. Population dose estimates must be performed to provide a measure of the impact from site radiological releases. Results of the U.S. 2010 Census were used to determine counts and distributions for the residential population located within 50-miles of several operating areas of the Hanford Site. Year 2010 was the first census year that a 50-mile population of a Hanford Site operational area exceeded the half-million mark.

  9. Stellar Populations in Circumnuclear Star Forming Regions

    E-Print Network [OSTI]

    A. I. Diaz; M. Alvarez-Alvarez; M. Castellanos

    2002-05-07T23:59:59.000Z

    We present a study of the stellar populations and gas physical conditions in Circumnuclear Star Forming Regions (CNSFR) based on broad and narrow band photometry and spectrophotometric data, which have been analyzed with the use of evolutionary population synthesis and photoionization models. It is found that most CNSFR show composite stellar populations of slightly different ages. They seem to have the highest abundances in HII region-like objects, showing also N/O overabundances and S/O underabundances by a factor of about three. Also, CNSFR as a class, segregate from the disk HII region family, clustering around smaller $\\eta$' values, and thereforefore higher ionizing temperatures.

  10. Lower crustal density estimation using the density-slowness relationship: a preliminary study

    E-Print Network [OSTI]

    Jones, Gary Wayne

    1996-01-01T23:59:59.000Z

    , and seismic velocity models were used to estimate the densities of th lower crustal rocks frcm the Wind River Mountains, the Ivrea Zone in Italy, and the average 1~ continental crustal model developed b/ ~istensen and Mconey [1995] . The. densities... by Carlson and Raskin [1984) yields a precision of about 1 percent. 'Ihe objective of this study is to evaluate this approach to estimate the density of the more complex continental crust, which is more variable in composition and affected hy a wider range...

  11. Population viability analysis of the Endangered shortnose sturgeon

    SciTech Connect (OSTI)

    Jager, Yetta [ORNL; Bevelhimer, Mark S [ORNL; Peterson, Douglas L. [University of Georgia, Athens, GA

    2011-07-01T23:59:59.000Z

    This study used population viability analysis (PVA) to partition the influences of potential threats to the endangered shortnose sturgeon (Acipenser brevirostrum). A workshop brought together experts to help identify potential threats including groundwater withdrawal, poor water quality, saltwater intrusion, mercury effects, harvest as by-catch, and sedimentation of spawning habitat. During the course of the project, we eliminated some threats and added new ones. Groundwater withdrawal was dismissed after a study failed to identify connection with groundwater and the majority of pumping is from a confined aquifer. We also eliminated activities on Fort Stewart as influences on spawning habitat because any successful spawning must occur upstream of Fort Stewart. We added climate change to the list of threats based on our assessment of temperature effects and expectations of sea-level rise. Our study highlighted the role of populations in nearby rivers in providing metapopulation support, raising the concern that the population in the Ogeechee River acts as a demographic sink. As part of this study, we carried out a field sampling study to analyze effects of training activities on headwater streams. We developed a new methodology for sampling design as part of this effort and used a mixed-modeling approach to identify relationships between land cover-land use, including those associated with military training activity and water quality. We found that tank training was associated with higher suspended sediment and equipment training was associated with higher organic carbon) and water quality. We detected effects of training on suspended sediment and organic carbon. We also carried out a field sampling effort in the Canoochee and Ogeechee Rivers. In the Ogeechee River, we found that dissolved oxygen in 40% of measurements during summer were below 4 mg L-1. To evaluate mercury as a potential threat, we developed a mercury uptake model and analyzed mercury levels in amphipod prey and sturgeon eggs. These did not exceed EPA guidelines. Finally, we developed a PVA model that including linkages between shortnose sturgeon growth, reproduction, and survival and each remaining threat; All three had significant influences. Preliminary simulations suggest that elevated temperatures under future climate will extirpate this population and add support to the hypothesis that this species requires access to spawning habitat far upstream to persist.

  12. Current density fluctuations and ambipolarity of transport

    SciTech Connect (OSTI)

    Shen, W.; Dexter, R.N.; Prager, S.C.

    1991-10-01T23:59:59.000Z

    The fluctuation in the plasma current density is measured in the MIST reversed field pinch experiment. Such fluctuations, and the measured radial profile of the k spectrum of magnetic fluctuations, supports the view and that low frequency fluctuations (f < 30 kHz) are tearing modes and high frequency fluctuations (30 kHz < f < 250 kHz) are localized turbulence in resonance with the local equilibrium magnetic field (i.e., k {center dot} B = 0). Correlation of current density and magnetic fluctuations (< {tilde j}{parallel}{tilde B}{sub r} >) demonstrates that radial particle transport from particle motion parallel to a fluctuating magnetic field is ambipolar over the full frequency range.

  13. Current density fluctuations and ambipolarity of transport

    SciTech Connect (OSTI)

    Shen, W.; Dexter, R.N.; Prager, S.C.

    1991-10-01T23:59:59.000Z

    The fluctuation in the plasma current density is measured in the MIST reversed field pinch experiment. Such fluctuations, and the measured radial profile of the k spectrum of magnetic fluctuations, supports the view and that low frequency fluctuations (f < 30 kHz) are tearing modes and high frequency fluctuations (30 kHz < f < 250 kHz) are localized turbulence in resonance with the local equilibrium magnetic field (i.e., k {center_dot} B = 0). Correlation of current density and magnetic fluctuations (< {tilde j}{parallel}{tilde B}{sub r} >) demonstrates that radial particle transport from particle motion parallel to a fluctuating magnetic field is ambipolar over the full frequency range.

  14. Oblique interactions of dust density waves

    SciTech Connect (OSTI)

    Wang, Zhelchui [Los Alamos National Laboratory; Li, Yang - Fang [MAX-PLANCK INSTITUTE; Hou, Lujing [MAX-PLANCK INSTITUTE; Jiang, Ke [MAX-PLANCK INSTITUTE; Wu, De - Jin [CHINA; Thomas, Hubertus M [MAX-PLANCK INSTITUTE; Morfill, Gregor E [MAX-PLANCK INSTITUTE

    2010-01-01T23:59:59.000Z

    Self-excited dust density waves (DDWs) are studied in a striped electrode device. In addition to the usual perpendicularly (with respect to the electrode) propagating DDWs, which have been frequently observed in dusty plasma experiments on the ground, a low-frequency oblique mode is also observed. This low-frequency oblique DDW has a frequency much lower than the dust plasma frequency and its spontaneous excitation is observed even with a very low dust density. It is found that the low-frequency oblique mode can exist either separately or together with the usual perpendicular mode. In the latter case, a new mode arises as a result of the interactions between the perpendicular and the oblique modes. The experiments show that these three modes satisfy the wave coupling conditions in both the frequencies and the wave-vectors.

  15. Global coherence of dust density waves

    SciTech Connect (OSTI)

    Killer, Carsten; Melzer, André [Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald (Germany)

    2014-06-15T23:59:59.000Z

    The coherence of self-excited three-dimensional dust density waves has been experimentally investigated by comparing global and local wave properties. For that purpose, three-dimensional dust clouds have been confined in a radio frequency plasma with thermophoretic levitation. Global wave properties have been measured from the line-of-sight integrated dust density obtained from homogenous light extinction measurements. Local wave properties have been obtained from thin, two-dimensional illuminated laser slices of the cloud. By correlating the simultaneous global and local wave properties, the spatial coherence of the waves has been determined. We find that linear waves with small amplitudes tend to be fragmented, featuring an incoherent wave field. Strongly non-linear waves with large amplitudes, however, feature a strong spatial coherence throughout the dust cloud, indicating a high level of synchronization.

  16. Ultra-high density diffraction grating

    DOE Patents [OSTI]

    Padmore, Howard A.; Voronov, Dmytro L.; Cambie, Rossana; Yashchuk, Valeriy V.; Gullikson, Eric M.

    2012-12-11T23:59:59.000Z

    A diffraction grating structure having ultra-high density of grooves comprises an echellette substrate having periodically repeating recessed features, and a multi-layer stack of materials disposed on the echellette substrate. The surface of the diffraction grating is planarized, such that layers of the multi-layer stack form a plurality of lines disposed on the planarized surface of the structure in a periodical fashion, wherein lines having a first property alternate with lines having a dissimilar property on the surface of the substrate. For example, in one embodiment, lines comprising high-Z and low-Z materials alternate on the planarized surface providing a structure that is suitable as a diffraction grating for EUV and soft X-rays. In some embodiments, line density of between about 10,000 lines/mm to about 100,000 lines/mm is provided.

  17. Development of Silica Aerogel with Any Density

    E-Print Network [OSTI]

    M. Tabata; I. Adachi; T. Fukushima; H. Kawai; H. Kishimoto; A. Kuratani; H. Nakayama; S. Nishida; T. Noguchi; K. Okudaira; Y. Tajima; H. Yano; H. Yokogawa; H. Yoshida

    Abstract–New production methods of silica aerogel with high and low refractive indices have been developed. A very slow shrinkage of alcogel at room temperature has made possible producing aerogel with high refractive indices of up to 1.265 without cracks. Even higher refractive indices than 1.08, the transmission length of the aerogel obtained from this technique has been measured to be about 10 to 20 mm at 400 nm wave length. A mold made of alcogel which endures shrinkage in the supercritical drying process has provided aerogel with the extremely low density of 0.009g/cm 3, which corresponds to the refractive index of 1.002. We have succeeded producing aerogel with a wide range of densities. I.

  18. Nuclear fission in covariant density functional theory

    E-Print Network [OSTI]

    A. V. Afanasjev; H. Abusara; P. Ring

    2013-09-12T23:59:59.000Z

    The current status of the application of covariant density functional theory to microscopic description of nuclear fission with main emphasis on superheavy nuclei (SHN) is reviewed. The softness of SHN in the triaxial plane leads to an emergence of several competing fission pathes in the region of the inner fission barrier in some of these nuclei. The outer fission barriers of SHN are considerably affected both by triaxiality and octupole deformation.

  19. Energy-momentum Density of Gravitational Waves

    E-Print Network [OSTI]

    Amir M. Abbassi; Saeed Mirshekari

    2014-11-29T23:59:59.000Z

    In this paper, we elaborate the problem of energy-momentum in general relativity by energy-momentum prescriptions theory. Our aim is to calculate energy and momentum densities for the general form of gravitational waves. In this connection, we have extended the previous works by using the prescriptions of Bergmann and Tolman. It is shown that they are finite and reasonable. In addition, using Tolman prescription, exactly, leads to same results that have been obtained by Einstein and Papapetrou prescriptions.

  20. Update of axion CDM energy density

    SciTech Connect (OSTI)

    Huh, Ji-Haeng [Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2008-11-23T23:59:59.000Z

    We update cosmological bound on axion model. The contribution from the anharmonic effect and the newly introduced initial overshoot correction are considered. We present an explicit formula for the axion relic density in terms of the QCD scale {lambda}{sub QCD}, the current quark masses m{sub q}'s and the Peccei-Quinn scale F{sub a}, including firstly introduced 1.85 factor which is from the initial overshoot.

  1. Mapping densities in a noisy state space

    E-Print Network [OSTI]

    Domenico Lippolis

    2013-03-05T23:59:59.000Z

    Weak noise smooths out fractals in a chaotic state space and introduces a maximum attainable resolution to its structure. The balance of noise and deterministic stretching/contraction in each neighborhood introduces local invariants of the dynamics that can be used to partition the state space. We study the local discrete-time evolution of a density in a two-dimensional hyperbolic state space, and use the asymptotic eigenfunctions for the noisy dynamics to formulate a new state space partition algorithm.

  2. Fiber felts as low density structural materials

    SciTech Connect (OSTI)

    Milewski, J.V.; Newfield, S.E.

    1981-01-01T23:59:59.000Z

    Short fiber felts structures can be made which provide improvements in properties over foams. In applications where resistance to compression set or stress relaxation are important, bonded fiber felts excel due to the flexing of individual fibers within their elastic limit. Felts of stainless steel and polyester fibers were prepared by deposition from liquid slurries. Compressive properties were determined as a function of felt parent material, extent of bonding, felt density, and length-to-diameter (L/D) ratio of starting fibers.

  3. Energy trapping from Hagedorn densities of states

    E-Print Network [OSTI]

    Connor Behan; Klaus Larjo; Nima Lashkari; Brian Swingle; Mark Van Raamsdonk

    2013-04-26T23:59:59.000Z

    In this note, we construct simple stochastic toy models for holographic gauge theories in which distributions of energy on a collection of sites evolve by a master equation with some specified transition rates. We build in only energy conservation, locality, and the standard thermodynamic requirement that all states with a given energy are equally likely in equilibrium. In these models, we investigate the qualitative behavior of the dynamics of the energy distributions for different choices of the density of states for the individual sites. For typical field theory densities of states (\\log(\\rho(E)) ~ E^{\\alphaenergy spread out relatively quickly. For large N gauge theories with gravitational duals, the density of states for a finite volume of field theory degrees of freedom typically includes a Hagedorn regime (\\log(\\rho(E)) ~ E). We find that this gives rise to a trapping of energy in subsets of degrees of freedom for parametrically long time scales before the energy leaks away. We speculate that this Hagedorn trapping may be part of a holographic explanation for long-lived gravitational bound states (black holes) in gravitational theories.

  4. Conditions when hybridization might predispose populations

    E-Print Network [OSTI]

    COMMENTARY Conditions when hybridization might predispose populations for adaptive radiation O (Sch- warzer et al., 2012), perhaps just as a consequence of many young species in geographical et al., 2011; Genner & Turner, 2012). Whether these species radiations happen despite hybridization

  5. Method for spatially distributing a population

    DOE Patents [OSTI]

    Bright, Edward A [Knoxville, TN; Bhaduri, Budhendra L [Knoxville, TN; Coleman, Phillip R [Knoxville, TN; Dobson, Jerome E [Lawrence, KS

    2007-07-24T23:59:59.000Z

    A process for spatially distributing a population count within a geographically defined area can include the steps of logically correlating land usages apparent from a geographically defined area to geospatial features in the geographically defined area and allocating portions of the population count to regions of the geographically defined area having the land usages, according to the logical correlation. The process can also include weighing the logical correlation for determining the allocation of portions of the population count and storing the allocated portions within a searchable data store. The logically correlating step can include the step of logically correlating time-based land usages to geospatial features of the geographically defined area. The process can also include obtaining a population count for the geographically defined area, organizing the geographically defined area into a plurality of sectors, and verifying the allocated portions according to direct observation.

  6. Stellar Populations in Bulges of Spiral Galaxies

    E-Print Network [OSTI]

    P. Jablonka; J. Gorgas; P. Goudfrooij

    2002-02-01T23:59:59.000Z

    We have conducted a spectroscopic analysis of the bulges of a sample of 31 spiral galaxies, spanning the Hubble sequence from S0 to Scd type, in order to study the radial distribution of their stellar population properties.

  7. Population dynamic interference among childhood diseases

    E-Print Network [OSTI]

    Rohani, Pejman

    is predicted and cannot be dismissed in the limited case-study data available for measles and whooping cough in England before the vaccination era. Keywords: measles; whooping cough; population dynamics; epidemiology

  8. Optimally focused cold atom systems obtained using density-density correlations

    SciTech Connect (OSTI)

    Putra, Andika; Campbell, Daniel L.; Price, Ryan M.; Spielman, I. B. [Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology, College Park, Maryland 20742 (United States)] [Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology, College Park, Maryland 20742 (United States); De, Subhadeep [Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology, College Park, Maryland 20742 (United States) [Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology, College Park, Maryland 20742 (United States); CSIR-National Physical Laboratory, New Delhi 110012 (India)

    2014-01-15T23:59:59.000Z

    Resonant absorption imaging is a common technique for detecting the two-dimensional column density of ultracold atom systems. In many cases, the system's thickness along the imaging direction greatly exceeds the imaging system's depth of field, making the identification of the optimally focused configuration difficult. Here we describe a systematic technique for bringing Bose-Einstein condensates (BEC) and other cold-atom systems into an optimal focus even when the ratio of the thickness to the depth of field is large: a factor of 8 in this demonstration with a BEC. This technique relies on defocus-induced artifacts in the Fourier-transformed density-density correlation function (the power spectral density, PSD). The spatial frequency at which these artifacts first appear in the PSD is maximized on focus; the focusing process therefore both identifies and maximizes the range of spatial frequencies over which the PSD is uncontaminated by finite-thickness effects.

  9. Dynamics of similar populations Geza Meszena1

    E-Print Network [OSTI]

    Meszéna, Géza

    Dynamics of similar populations G´eza Mesz´ena1 , Mats Gyllenberg2 , Frans J. Jacobs3 , Hans A. J. Metz3,4 1 E¨otv¨os Univerity, Budapest 2 University of Helsinki 3 Leiden University 4 Adaptive Dynamics by population dynamics: dni dt = ri (n1, n2, . . . , nL) ni i = 1, 2, . . . , L ni 0 for losers. Dynamics

  10. Space and time resolved spectroscopy of laser-produced plasmas: A study of density-sensitive x-ray transitions in helium-like and neon-like ions

    SciTech Connect (OSTI)

    Young, Bruce Kai Fong

    1988-09-01T23:59:59.000Z

    The determination of level populations and detailed population mechanisms in dense plasmas has become an increasingly important problem in atomic physics. In this work, the density variation of line intensities and level populations in aluminum K-shell and molybdenum and silver L-shell emission spectra have been measured from high-powered, laser-produced plasmas. For each case, the density dependence of the observed line emission is due to the effect of high frequency electron-ion collisions on metastable levels. The density dependent line intensities vary greatly in laser-produced plasmas and can be used to extract detailed information concerning the population kinetics and level populations of the ions. The laser-plasmas had to be fully characterized in order to clearly compare the observed density dependence with atomic theory predictions. This has been achieved through the combined use of new diagnostic instruments and microdot targets which provided simultaneously space, time, and spectrally resolved data. The plasma temperatures were determined from the slope of the hydrogen-like recombination continuum. The time resolved electron density profiles were measured using multiple frame holographic interferometry. Thus, the density dependence of K-shell spectral lines could be clearly examined, independent of assumptions concerning the dynamics of the plasma. In aluminum, the electron density dependence of various helium-like line intensity ratios were measured. Standard collisional radiative equilibrium models fail to account for the observed density dependence measured for the ''He/sub ..cap alpha..//IC'' ratio. Instead, a quasi-steady state atomic model based on a purely recombining plasma is shown to accurately predict the measured density dependence. This same recombining plasma calculation successfully models the density dependence of the high-n ''He/sub ..gamma..//He/sub ..beta../'' and ''He/sub delta//He/sub ..beta../'' helium-like resonance line intensity ratios.

  11. A Multi-Resolution Large Population Game Framework for Smart Grid Demand Response Management

    E-Print Network [OSTI]

    Boyer, Edmond

    A Multi-Resolution Large Population Game Framework for Smart Grid Demand Response Management Quanyan Zhu and Tamer Bas¸ar Abstract--Dynamic demand response (DR) management is becoming an integral, active operation, and efficient demand response. A reliable and efficient communication and networking

  12. Brain covariance selection: better individual functional connectivity models using population prior

    E-Print Network [OSTI]

    Brain covariance selection: better individual functional connectivity models using population prior.thirion@inria.fr Abstract Spontaneous brain activity, as observed in functional neuroimaging, has been shown to display reproducible structure that expresses brain architecture and car- ries markers of brain pathologies

  13. X-ray source populations in galaxies

    E-Print Network [OSTI]

    G. Fabbiano

    2005-11-16T23:59:59.000Z

    Today's sensitive, high-resolution X-ray observations allow the study of populations of X-ray sources, in the luminosity range of Galactic X-ray binaries, in galaxies as distant as 20-30 Mpc. The traditional astronomical tools of photometric diagrams and luminosity functions are now applied to these populations, providing a direct probe of the evolved binary component of different stellar populations. The study of the X-ray populations of E and S0 galaxies has revamped the debate on the formation and evolution of low-mass X-ray binaries (LMXBs) and on the role of globular clusters in these processes. While overall stellar mass drives the amount of X-ray binaries in old stellar populations, the amount of sources in star forming galaxies is related to the star formation rate. Short-lived, luminous, high-mass binaries (HMXBs) dominate these young populations. The most luminous sources in these systems are the debated ULXs, which have been suggested to be ~100-1000 Msol black holes, but could alternatively include a number of binaries with stellar mass black holes. Very soft sources have also been discovered in many galaxies and their nature is currently being debated. Observations of the deep X-ray sky, and comparison with deep optical surveys, are providing the first evidence of the X-ray evolution of galaxies.

  14. Molecular analysis of the metabolic rates of discrete subsurface populations of sulfate reducers

    SciTech Connect (OSTI)

    Miletto, M.; Williams, K.H.; N'Guessan, A.L.; Lovley, D.R.

    2011-04-01T23:59:59.000Z

    Elucidating the in situ metabolic activity of phylogenetically diverse populations of sulfate-reducing microorganisms that populate anoxic sedimentary environments is key to understanding subsurface ecology. Previous pure culture studies have demonstrated that transcript abundance of dissimilatory (bi)sulfite reductase genes is correlated with the sulfate reducing activity of individual cells. To evaluate whether expression of these genes was diagnostic for subsurface communities, dissimilatory (bi)sulfite reductase gene transcript abundance in phylogenetically distinct sulfate-reducing populations was quantified during a field experiment in which acetate was added to uranium-contaminated groundwater. Analysis of dsrAB sequences prior to the addition of acetate indicated that Desulfobacteraceae, Desulfobulbaceae, and Syntrophaceae-related sulfate reducers were the most abundant. Quantifying dsrB transcripts of the individual populations suggested that Desulfobacteraceae initially had higher dsrB transcripts per cell than Desulfobulbaceae or Syntrophaceae populations, and that the activity of Desulfobacteraceae increased further when the metabolism of dissimilatory metal reducers competing for the added acetate declined. In contrast, dsrB transcript abundance in Desulfobulbaceae and Syntrophaceae remained relatively constant, suggesting a lack of stimulation by added acetate. The indication of higher sulfate-reducing activity in the Desulfobacteraceae was consistent with the finding that Desulfobacteraceae became the predominant component of the sulfate-reducing community. Discontinuing acetate additions resulted in a decline in dsrB transcript abundance in the Desulfobacteraceae. These results suggest that monitoring transcripts of dissimilatory (bi)sulfite reductase genes in distinct populations of sulfate reducers can provide insight into the relative rates of metabolism of different components of the sulfate-reducing community and their ability to respond to environmental perturbations.

  15. Dwarf galaxy dark matter density profiles inferred from stellar and gas kinematics

    SciTech Connect (OSTI)

    Adams, Joshua J.; Simon, Joshua D. [Observatories of the Carnegie Institution of Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Fabricius, Maximilian H.; Bender, Ralf; Thomas, Jens [Max-Planck Institut für extraterrestrische Physik, Giessenbachstraße, D-85741 Garching bei München (Germany); Van den Bosch, Remco C. E.; Van de Ven, Glenn [Max-Planck Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Barentine, John C.; Gebhardt, Karl; Hill, Gary J. [Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 (United States); Murphy, Jeremy D. [Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Peyton Hall, Princeton, NJ 08544 (United States); Swaters, R. A., E-mail: jjadams@obs.carnegiescience.edu, E-mail: jja439@gmail.com [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States)

    2014-07-01T23:59:59.000Z

    We present new constraints on the density profiles of dark matter (DM) halos in seven nearby dwarf galaxies from measurements of their integrated stellar light and gas kinematics. The gas kinematics of low-mass galaxies frequently suggest that they contain constant density DM cores, while N-body simulations instead predict a cuspy profile. We present a data set of high-resolution integral-field spectroscopy on seven galaxies and measure the stellar and gas kinematics simultaneously. Using Jeans modeling on our full sample, we examine whether gas kinematics in general produce shallower density profiles than are derived from the stars. Although two of the seven galaxies show some localized differences in their rotation curves between the two tracers, estimates of the central logarithmic slope of the DM density profile, ?, are generally robust. The mean and standard deviation of the logarithmic slope for the population are ? = 0.67 ± 0.10 when measured in the stars and ? = 0.58 ± 0.24 when measured in the gas. We also find that the halos are not under-concentrated at the radii of half their maximum velocities. Finally, we search for correlations of the DM density profile with stellar velocity anisotropy and other baryonic properties. Two popular mechanisms to explain cored DM halos are an exotic DM component or feedback models that strongly couple the energy of supernovae into repeatedly driving out gas and dynamically heating the DM halos. While such models do not yet have falsifiable predictions that we can measure, we investigate correlations that may eventually be used to test models. We do not find a secondary parameter that strongly correlates with the central DM density slope, but we do find some weak correlations. The central DM density slope weakly correlates with the abundance of ? elements in the stellar population, anti-correlates with H I fraction, and anti-correlates with vertical orbital anisotropy. We expect, if anything, the opposite of these three trends for feedback models. Determining the importance of these correlations will require further model developments and larger observational samples.

  16. Cottontail density and distribution on three study areas in Yoakum County, Texas

    E-Print Network [OSTI]

    Tanner, Jimmy Ishmael

    1979-01-01T23:59:59.000Z

    the pellet count indicated a significance (p&0. 05) difference in cottontail population densities between rangeland and cropland. This was due to an almost total absence of pellets in the cropland which may have been caused by a difference in pellet... shrubs of the Chihuahuan Desert offered a physical barrier to predators. Cottontails commonly dig a shallow nest of about 10 cm (3. 9 in) deep to protect their young (Hendrickson 1940); however, unlike the 6 p bbtt (~0to1 ~ c tc 1 t ) (Lo ktey 1964...

  17. The ESO Nearby Abell Cluster Survey IX. The morphology-radius and morphology-density relations in rich galaxy clusters

    E-Print Network [OSTI]

    T. Thomas; P. Katgert

    2005-10-10T23:59:59.000Z

    We study the morphology-radius (MR-) and morphology-density (MD-) relations for a sample of about 850 galaxies (with M = -22), the S0 galaxies and the early spirals have different Sigma1-distributions. The reason for this is that Sigma1 is much less correlated with R than is Sigma10, and thus has much less cross-talk from the (MR-) relation. On average, the 'normal' ellipticals populate environments with higher projected density than do the S0 galaxies while the early spirals populate even less dense environments. The segregation of the brightest ellipticals and the late spirals is driven mostly by global factors, while the segregation between 'normal' ellipticals, S0 galaxies and early spirals is driven primarily by local factors.

  18. Symmetry energy in nuclear density functional theory

    E-Print Network [OSTI]

    W. Nazarewicz; P. -G. Reinhard; W. Satula; D. Vretenar

    2013-07-22T23:59:59.000Z

    The nuclear symmetry energy represents a response to the neutron-proton asymmetry. In this survey we discuss various aspects of symmetry energy in the framework of nuclear density functional theory, considering both non-relativistic and relativistic self-consistent mean-field realizations side-by-side. Key observables pertaining to bulk nucleonic matter and finite nuclei are reviewed. Constraints on the symmetry energy and correlations between observables and symmetry-energy parameters, using statistical covariance analysis, are investigated. Perspectives for future work are outlined in the context of ongoing experimental efforts.

  19. Method of high-density foil fabrication

    DOE Patents [OSTI]

    Blue, Craig A.; Sikka, Vinod K.; Ohriner, Evan K.

    2003-12-16T23:59:59.000Z

    A method for preparing flat foils having a high density includes the steps of mixing a powdered material with a binder to form a green sheet. The green sheet is exposed to a high intensity radiative source adapted to emit radiation of wavelengths corresponding to an absorption spectrum of the powdered material. The surface of the green sheet is heated while a lower sub-surface temperature is maintained. An apparatus for preparing a foil from a green sheet using a radiation source is also disclosed.

  20. Generalized Holographic Quantum Criticality at Finite Density

    E-Print Network [OSTI]

    B. Goutéraux; E. Kiritsis

    2013-01-23T23:59:59.000Z

    We show that the near-extremal solutions of Einstein-Maxwell-Dilaton theories, studied in ArXiv:1005.4690, provide IR quantum critical geometries, by embedding classes of them in higher-dimensional AdS and Lifshitz solutions. This explains the scaling of their thermodynamic functions and their IR transport coefficients, the nature of their spectra, the Gubser bound, and regulates their singularities. We propose that these are the most general quantum critical IR asymptotics at finite density of EMD theories.

  1. Particle transport inferences from density sawteeth

    SciTech Connect (OSTI)

    Chen, J.; Li, Q.; Zhuang, G. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Liao, K.; Gentle, K. W., E-mail: k.gentle@mail.utexas.edu [Institute for Fusion Studies, University of Texas, Austin, Texas 78712 (United States)

    2014-05-15T23:59:59.000Z

    Sawtooth oscillations in tokamaks are defined by their effect on electron temperature: a rapid flattening of the core profile followed by an outward heat pulse and a slow core recovery caused by central heating. Recent high-resolution, multi-chord interferometer measurements on JTEXT extend these studies to particle transport. Sawteeth only partially flatten the core density profile, but enhanced particle diffusion on the time scale of the thermal crash occurs over much of the profile, relevant for impurities. Recovery between crashes implies an inward pinch velocity extending to the center.

  2. Low density inorganic foams fabricated using microwaves

    SciTech Connect (OSTI)

    Meek, T.T.; Blake, R.D.; Gregory, T.G.

    1985-01-01T23:59:59.000Z

    The objective of our work was to determine if high temperature foams could be made using microwave heating; and if so, to investigate some of their properties. Several foams were made and their compressive strengths, tensile strengths and densities were determined. Foams were made of glass, metal-glass, glass-fiber, metal-glass-fiber, and fly ash. The microwave source used was a Litton model 1521 microwave oven which operated at 2.45 GHz and had an output of 700 watts.

  3. Nuclear Energy Density Optimization: UNEDF2

    E-Print Network [OSTI]

    M. Kortelainen; J. McDonnell; W. Nazarewicz; E. Olsen; P. -G. Reinhard; J. Sarich; N. Schunck; S. M. Wild; D. Davesne; J. Erler; A. Pastore

    2014-10-30T23:59:59.000Z

    The parameters of the UNEDF2 nuclear energy density functional (EDF) model were obtained in an optimization to experimental data consisting of nuclear binding energies, proton radii, odd-even mass staggering data, fission-isomer excitation energies, and single particle energies. In addition to parameter optimization, sensitivity analysis was done to obtain parameter uncertainties and correlations. The resulting UNEDF2 is an all-around EDF. However, the sensitivity analysis also demonstrated that the limits of current Skyrme-like EDFs have been reached and that novel approaches are called for.

  4. Wigner density of a rigid rotator

    SciTech Connect (OSTI)

    Malta, C.P. [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, 05315-970 Sao Paulo (Brazil)] [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, 05315-970 Sao Paulo (Brazil); Marshall, T.S. [Department of Mathematics, University of Manchester, Manchester M139PL (United Kingdom)] [Department of Mathematics, University of Manchester, Manchester M139PL (United Kingdom); Santos, E. [Departamento de Fisica Moderna, Universidad de Cantabria, 39005, Santander (Spain)] [Departamento de Fisica Moderna, Universidad de Cantabria, 39005, Santander (Spain)

    1997-03-01T23:59:59.000Z

    We show that the Wigner density of the rigid rotator, in an appropriate, i.e., four-dimensional, phase space, is positive. This result holds in the ground state (S state), and also in the thermal mixture state at all finite temperatures. We discuss the implications of our result for the description of angular momentum in quantum mechanics; in particular, we reexamine, in the light of this new evidence, the suggestion made by Einstein and Stern [Ann. Phys. {bold 40}, 551 (1913)] that there is a nontrivial distribution of angular momentum in the S state. {copyright} {ital 1997} {ital The American Physical Society}

  5. High Energy Density Ultracapacitors | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(Fact Sheet), GeothermalGridHYDROGEN TOTechnologyHigh Efficiency Low -1 DOE

  6. High Energy Density Ultracapacitors | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(Fact Sheet), GeothermalGridHYDROGEN TOTechnologyHigh Efficiency Low -1 DOE0 DOE

  7. High Energy Density Ultracapacitors | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(Fact Sheet), GeothermalGridHYDROGEN TOTechnologyHigh Efficiency Low -1 DOE0 DOE09

  8. asian populations levels: Topics by E-print Network

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

    asymptomatic condition, that is widespread in Southeast Asian populations of Malasia, Indonesia, Papua New Guinea (more) Ziervogel, Cheryl Anne 2008-01-01 2 Population Total...

  9. asian population predictors: Topics by E-print Network

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

    asymptomatic condition, that is widespread in Southeast Asian populations of Malasia, Indonesia, Papua New Guinea (more) Ziervogel, Cheryl Anne 2008-01-01 2 Population Total...

  10. asian population modified: Topics by E-print Network

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

    asymptomatic condition, that is widespread in Southeast Asian populations of Malasia, Indonesia, Papua New Guinea (more) Ziervogel, Cheryl Anne 2008-01-01 2 Population Total...

  11. asian population lessons: Topics by E-print Network

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

    asymptomatic condition, that is widespread in Southeast Asian populations of Malasia, Indonesia, Papua New Guinea (more) Ziervogel, Cheryl Anne 2008-01-01 2 Population Total...

  12. asian populations identifies: Topics by E-print Network

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

    asymptomatic condition, that is widespread in Southeast Asian populations of Malasia, Indonesia, Papua New Guinea (more) Ziervogel, Cheryl Anne 2008-01-01 2 Population Total...

  13. Will China's Vehicle Population Grow Even Faster than Forecasted?

    E-Print Network [OSTI]

    Wang, Yunshi; Teter, Jacob; Sperling, Daniel

    2012-01-01T23:59:59.000Z

    2011. “China’s Soaring Vehicle Population: Even Greater Thanversion, “China’s Soaring Vehicle Population: Even Greater2012. “Modeling Future Vehicle Sales and Stock in China,”

  14. The density of states approach for the simulation of finite density quantum field theories

    E-Print Network [OSTI]

    K. Langfeld; B. Lucini; A. Rago; R. Pellegrini; L. Bongiovanni

    2015-03-02T23:59:59.000Z

    Finite density quantum field theories have evaded first principle Monte-Carlo simulations due to the notorious sign-problem. The partition function of such theories appears as the Fourier transform of the generalised density-of-states, which is the probability distribution of the imaginary part of the action. With the advent of Wang-Landau type simulation techniques and recent advances, the density-of-states can be calculated over many hundreds of orders of magnitude. Current research addresses the question whether the achieved precision is high enough to reliably extract the finite density partition function, which is exponentially suppressed with the volume. In my talk, I review the state-of-play for the high precision calculations of the density-of-states as well as the recent progress for obtaining reliable results from highly oscillating integrals. I will review recent progress for the $Z_3$ quantum field theory for which results can be obtained from the simulation of the dual theory, which appears to free of a sign problem.

  15. Identifying Activity

    E-Print Network [OSTI]

    Lewis, Adrian S

    2009-01-01T23:59:59.000Z

    Identification of active constraints in constrained optimization is of interest from both practical and theoretical viewpoints, as it holds the promise of reducing an inequality-constrained problem to an equality-constrained problem, in a neighborhood of a solution. We study this issue in the more general setting of composite nonsmooth minimization, in which the objective is a composition of a smooth vector function c with a lower semicontinuous function h, typically nonsmooth but structured. In this setting, the graph of the generalized gradient of h can often be decomposed into a union (nondisjoint) of simpler subsets. "Identification" amounts to deciding which subsets of the graph are "active" in the criticality conditions at a given solution. We give conditions under which any convergent sequence of approximate critical points finitely identifies the activity. Prominent among these properties is a condition akin to the Mangasarian-Fromovitz constraint qualification, which ensures boundedness of the set of...

  16. Exposure to airborne metals and particulate matter and risk for youth adjudicated for criminal activity

    SciTech Connect (OSTI)

    Haynes, Erin N., E-mail: Erin.Haynes@uc.edu [College of Medicine, Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267 (United States); Chen, Aimin, E-mail: Aimin.Chen@uc.edu [College of Medicine, Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267 (United States)] [College of Medicine, Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267 (United States); Ryan, Patrick, E-mail: Patrick.Ryan@uc.edu [College of Medicine, Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267 (United States)] [College of Medicine, Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267 (United States); Succop, Paul, E-mail: Paul.Succop@uc.edu [College of Medicine, Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267 (United States)] [College of Medicine, Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267 (United States); Wright, John, E-mail: John.Wright@uc.edu [College of Education, Criminal Justice, and Human Services, University of Cincinnati, Cincinnati, OH 45221 (United States)] [College of Education, Criminal Justice, and Human Services, University of Cincinnati, Cincinnati, OH 45221 (United States); Dietrich, Kim N., E-mail: Kim.Dietrich@uc.edu [College of Medicine, Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267 (United States)

    2011-11-15T23:59:59.000Z

    Antisocial behavior is a product of multiple interacting sociohereditary variables, yet there is increasing evidence that metal exposure, particularly, manganese and lead, play a role in its epigenesis. Other metals, such as arsenic, cadmium, chromium, and mercury, and exposure to traffic-related air pollution, such as fine particulate matter ({<=}2.5 {mu}m) have been associated with neurological deficits, yet largely unexplored with respect to their relationship with delinquent behavior. The purpose of this study is to evaluate the ecological relationship between county-wide reported airborne emissions of air metals, particulate matter, and youth adjudicated for criminal activity. Metal exposure data were collected from the Environmental Protection Agency AirData. Population statistics were obtained from the United States Census 2000 and adjudication data was obtained from the Courts of Common Pleases from each Ohio County. Simple correlations were calculated with the percentage of adjudications, all covariates, and estimated metal air emissions. Separate negative binomial regression models for each pollutant were used to provide an estimated risk ratio of pollutant emissions on the risk of adjudication for all Ohio counties adjusting for urban-rural residence, percentage of African Americans, median family income, percentage of family below poverty, percentage of high school graduation in 25 years and older populations, and population density. Metal emissions and PM in 1999 were all correlated with adjudication rate (2003-2005 average). Metal emissions were associated with slightly higher risk of adjudication, with about 3-4% increased risk per natural log unit of metal emission except chromium. The associations achieved statistical significance for manganese and mercury. The particulate matter {<=}2.5 and {<=}10 {mu}m emissions had a higher risk estimate, with 12% and 19% increase per natural log unit emission, respectively, and also achieved statistical significance. In summary, airborne exposure to manganese, mercury, and particulate matter are associated with increased risk of adjudication. Causality cannot be proven in observational studies such as this one, but the association warrants further examination in other research studies. Comprehensive epidemiologic investigations of metal exposure in pediatric populations should include social health outcomes, including measures of delinquent or criminal activity. Furthermore, the influence of metals on the neurotoxic pathway leading to delinquent activity should be further explored. - Highlights: Black-Right-Pointing-Pointer We evaluate the relationship between air pollutants and adjudication. Black-Right-Pointing-Pointer Manganese, mercury, and particulate matter are associated with risk of adjudication. Black-Right-Pointing-Pointer Further research of metal exposure should include social health outcomes.

  17. Measuring the entanglement of analogue Hawking radiation by the density-density correlation function

    E-Print Network [OSTI]

    Steinhauer, Jeff

    2015-01-01T23:59:59.000Z

    We theoretically study the entanglement of Hawking radiation emitted by an analogue black hole. We find that this entanglement can be measured by the experimentally accessible density-density correlation function, which only requires standard imaging techniques. It is seen that the high energy tail of the distribution of Hawking radiation should be entangled, whereas the low energy part is not. This confirms a previous numerical study. The full Peres-Horodecki criterion is considered, but a significant simplification is found in the stationary, homogeneous case. Our method applies to systems which are sufficiently cold that the thermal phonons can be neglected.

  18. Activity report

    SciTech Connect (OSTI)

    Yu, S W

    2008-08-11T23:59:59.000Z

    This report is aimed to show the author's activities to support the LDRD. The title is 'Investigation of the Double-C Behavior in the Pu-Ga Time-Temperature-Transformation Diagram' The sections are: (1) Sample Holder Test; (2) Calculation of x-ray diffraction patterns; (3) Literature search and preparing publications; (4) Tasks Required for APS Experiments; and (5) Communications.

  19. New possible resonance for population II Cepheids

    SciTech Connect (OSTI)

    Cox, A.N.; Kidman, R.B.

    1984-01-01T23:59:59.000Z

    Light and velocity curves of some radial mode variable stars seem to indicate a resonance where the second overtone has a period exactly half that of the fundamental mode. The two classes of stars that show this resonance by bumps in their light curves are the classical Cepheids and the population II BL Her variables. We here propose that there is another resonance for the population II W Vir variables where the ratio of the first overtone to the fundamental periods is 0.5.

  20. A Decade of Population Change in Texas.

    E-Print Network [OSTI]

    Skrabanek, R. L.

    1963-01-01T23:59:59.000Z

    of community facilities. The political representation of rural dwellers is also likely to be reduced. 3. In 1960, for the first time in history, Texas had more females than males. The projected sex ratio is 96.7 males per 100 females in 1970. At the same... of the Panhandle and extending southward beyond Abilene. This area sustained a decline of one-third in rural population during the decade. Only 2 of the 29 counties (Cottle and Donley) in area 6 had an increase in rural population. Another section, state...

  1. On the mechanism of populating 3p levels of neon under pumping by a hard ioniser

    SciTech Connect (OSTI)

    Khasenov, M U [Fotonika LLC, ul. Utegen batyra 112, 050062 Almaty (Kazakhstan)

    2011-03-31T23:59:59.000Z

    The effect of quenching additives on the luminescence properties of helium - neon mixtures under pumping by {alpha} particles emitted from {sup 210}Po atoms is considered. It is concluded that, under excitation by a heavy charged particle, the population of the 3p'[1/2]{sub 0} level of neon is not related to the dissociative recombination of molecular ions. It is suggested that the most likely channels for populating the 3p level are the excitation transfer from metastable helium atoms to neon atoms and direct excitation of neon by nuclear particles and secondary electrons. (lasers and active media)

  2. Marking Streets to Improve Parking Density

    E-Print Network [OSTI]

    Xu, Chao

    2015-01-01T23:59:59.000Z

    Street parking spots for automobiles are a scarce commodity in most urban environments. The heterogeneity of car sizes makes it inefficient to rigidly define fixed-sized spots. Instead, unmarked streets in cities like New York leave placement decisions to individual drivers, who have no direct incentive to maximize street utilization. In this paper, we explore the effectiveness of two different behavioral interventions designed to encourage better parking, namely (1) educational campaigns to encourage parkers to "kiss the bumper" and reduce the distance between themselves and their neighbors, or (2) painting appropriately-spaced markings on the street and urging drivers to "hit the line". Through analysis and simulation, we establish that the greatest densities are achieved when lines are painted to create spots roughly twice the length of average-sized cars. Kiss-the-bumper campaigns are in principle more effective than hit-the-line for equal degrees of compliance, although we believe that the visual cues of...

  3. Ternary liquid mixture viscosities and densities

    SciTech Connect (OSTI)

    Wei, I.C.; Rowley, R.L.

    1984-01-01T23:59:59.000Z

    Liquid mixture viscosities and densities have been measured at 298.15 K and ambient pressure for 20 ternary systems. Twelve ternary compositions, encompassing the entire composition range, have been chosen for each system in an effort to test a newly proposed predictive equation based on local compositions. Viscosities calculated by using the local composition model agreed with the experimental data within an average absolute deviation of 6.4%. No adjustable parameters were used and only binary interactions in the form of NRTL constants were input. The results of these studies indicate that the local composition model predictions are generally as good for multicomponent systems as they are for the corresponding binaries. 24 references, 3 tables.

  4. Competition between superconductivity and spin density wave

    E-Print Network [OSTI]

    Tian De Cao

    2012-08-25T23:59:59.000Z

    The Hubbard model has been investigated widely by many authors, while this work may be new in two aspects. One, we focus on the possible effects of the positions of the gaps associated with the pairing and the spin density wave. Two, we suggest that the models with different parameters are appropriate for different materials (or a material in different doped regions). This will lead to some new insights into the high temperature superconductors. It is shown that the SDW can appear at some temperature region when the on-site Coulomb interaction is larger, while the SC requires a decreased U at a lower temperature. This can qualitatively explain the relationship between superconducting and pseudogap states of Cu-based superconductors in underdoped and optimally doped regions. The superinsulator is also discussed.

  5. Band terminations in density functional theory

    E-Print Network [OSTI]

    A. V. Afanasjev

    2009-02-01T23:59:59.000Z

    The analysis of the terminating bands has been performed in the relativistic mean field framework. It was shown that nuclear magnetism provides an additional binding to the energies of the specific configuration and this additional binding increases with spin and has its {\\it maximum} exactly at the terminating state. This suggests that the terminating states can be an interesting probe of the time-odd mean fields {\\it provided that other effects can be reliably isolated.} Unfortunately, a reliable isolation of these effects is not that simple: many terms of the density functional theories contribute into the energies of the terminating states and the deficiencies in the description of those terms affect the result. The recent suggestion \\cite{ZSW.05} that the relative energies of the terminating states in the $N \

  6. Dworshak Kokanee Population and Engrainment Assessment : 2006 Annual Report, March 1, 2006 - February 28, 2007.

    SciTech Connect (OSTI)

    Stark, Eric J.

    2008-12-18T23:59:59.000Z

    During this contract, we continued testing underwater strobe lights to determine their effectiveness at repelling kokanee Oncorhynchus nerka away from Dworshak Dam. Strobe light tests were conducted on four nights from April 24-27, 2006, in front of the middle reservoir outlet (RO) 2. The density and distribution of fish, (thought to be mostly kokanee), were monitored with a split-beam echo sounder. We then compared fish counts and densities during nights when the lights were flashing to counts and densities during adjacent nights without the lights on. On two nights, April 25 and 27, 2006, when no lights were present, fish counts near RO 2 averaged 12.4 fish and densities averaged 31.0 fish/ha. When strobe lights were turned on during the nights of April 24 and 26, mean counts dropped to 4.7 fish and densities dropped to 0.5 fish/ha. The decline in counts (62%) and densities (99%) was statistically significant (p = 0.009 and 0.002, respectively). Test results indicated that strobe lights were able to reduce fish densities by at least 50% in front of a discharging reservoir outlet, which would be sufficient to improve sport fish harvest. We also used split-beam hydroacoustics to monitor the kokanee population in Dworshak Reservoir during 2006. Estimated abundance of kokanee increased from the 2005 population estimate. Based on hydroacoustic surveys, we estimated approximately 5,815,000 kokanee (90% CI {+-} 27.6%) in Dworshak Reservoir in August 2006. This included 2,183,000 age-0 (90% CI {+-} 24.2%), 1,509,000 age-1 (90% CI {+-} 29.0%), and 2,124,000 age-2 (90% CI {+-} 27.6%) kokanee. This resulted in a density of age-2 kokanee above the management goal of 30-50 adults/ha. Entrainment sampling was conducted with fixed-site, split-beam hydroacoustics from May through September for a continuous 24 h period when dam operations permitted. The highest fish detection rates from entrainment assessments were found during dawn periods, unlike previous year's results, which were highest during nighttime. The lowest detection rate was found during the day period, which was consistent with previous findings. Fish detection rates were generally low during high discharges throughout the summer and highest during low discharges in May and June. Low detection rates were found during high discharge periods during drawdowns for anadromous fish flows in July and August, which resulted in low susceptibility to entrainment. Counts of spawning kokanee in four tributary streams totaled 29,743 fish. These data fit the previously developed relationship between spawner counts and adult kokanee abundance in the reservoir.

  7. Conducting polymers as potential active materials in electrochemical supercapacitors

    SciTech Connect (OSTI)

    Rudge, A.; Davey, J.; Raistrick, I.; Gottesfeld, S. [Los Alamos National Lab., NM (United States); Ferraris, J.P. [Texas Univ., Richardson, TX (United States). Dept. of Chemistry

    1992-12-01T23:59:59.000Z

    Electronically,conducting polymers represent an interesting class of materials for use in electrochemical capacitors because of the combination of high capacitive energy density and low materials cost. Three generalized types of electrochemical capacitors can be constructed using conducting polymers as active material, and in the third of these, which utilizes conducting polymers that can be both n- and p-doped, energy densities of up to 40 watt-hours per kilogram of active material on both electrodes have been demonstrated.

  8. Conducting polymers as potential active materials in electrochemical supercapacitors

    SciTech Connect (OSTI)

    Rudge, A.; Davey, J.; Raistrick, I.; Gottesfeld, S. (Los Alamos National Lab., NM (United States)); Ferraris, J.P. (Texas Univ., Richardson, TX (United States). Dept. of Chemistry)

    1992-01-01T23:59:59.000Z

    Electronically,conducting polymers represent an interesting class of materials for use in electrochemical capacitors because of the combination of high capacitive energy density and low materials cost. Three generalized types of electrochemical capacitors can be constructed using conducting polymers as active material, and in the third of these, which utilizes conducting polymers that can be both n- and p-doped, energy densities of up to 40 watt-hours per kilogram of active material on both electrodes have been demonstrated.

  9. MULTIWAVELENGTH CONSTRAINTS ON PULSAR POPULATIONS IN THE GALACTIC CENTER

    SciTech Connect (OSTI)

    Wharton, R. S.; Chatterjee, S.; Cordes, J. M. [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States); Deneva, J. S. [Arecibo Observatory, HC3 Box 53995, Arecibo, PR 00612 (Puerto Rico); Lazio, T. J. W., E-mail: rwharton@astro.cornell.edu [Jet Propulsion Laboratory, California Institute of Technology, M/S 138-308, 4800 Oak Grove Dr., Pasadena, CA 91109 (United States)

    2012-07-10T23:59:59.000Z

    The detection of radio pulsars within the central few parsecs of the Galaxy would provide a unique probe of the gravitational and magneto-ionic environments in the Galactic center (GC) and, if close enough to Sgr A*, precise tests of general relativity in the strong-field regime. While it is difficult to find pulsars at radio wavelengths because of interstellar scattering, the payoff from detailed timing of pulsars in the GC warrants a concerted effort. To motivate pulsar surveys and help define search parameters for them, we constrain the pulsar number and spatial distribution using a wide range of multiwavelength measurements. These include the five known radio pulsars within 15' of Sgr A*, non-detections in high-frequency pulsar surveys of the central parsec, radio and gamma-ray measurements of diffuse emission, a catalog of radio point sources from an imaging survey, infrared observations of massive star populations in the central few parsecs, candidate pulsar wind nebulae in the inner 20 pc, and estimates of the core-collapse supernova rate based on X-ray measurements. We find that under current observational constraints, the inner parsec of the Galaxy could harbor as many as {approx}10{sup 3} active radio pulsars that are beamed toward Earth. Such a large population would distort the low-frequency measurements of both the intrinsic spectrum of Sgr A* and the free-free absorption along the line of sight of Sgr A*.

  10. Noisy Independent Factor Analysis Model for Density Estimation and Classification

    E-Print Network [OSTI]

    Amato, U.

    2009-06-09T23:59:59.000Z

    We consider the problem of multivariate density estimation when the unknown density is assumed to follow a particular form of dimensionality reduction, a noisy independent factor analysis (IFA) model. In this model the ...

  11. Experimental bond critical point and local energy density properties...

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

    Mn-O, Fe-O and Co-O bonded interactions for Abstract: Bond critical point, bcp, and local energy density properties for the electron density, ED, distributions, calculated with...

  12. Constrained Density-Functional Theory--Configuration Interaction

    E-Print Network [OSTI]

    Kaduk, Benjamin James

    2012-01-01T23:59:59.000Z

    In this thesis, I implemented a method for performing electronic structure calculations, "Constrained Density Functional Theory-- Configuration Interaction" (CDFT-CI), which builds upon the computational strengths of Density ...

  13. Nonparametric Comparison of Densities Based on Statistical Bootstrap

    E-Print Network [OSTI]

    Nonparametric Comparison of Densities Based on Statistical Bootstrap De Brabanter, K.1 , Sahhaf, S. Keywords: Statistical Bootstrap, Variance Stabilization, Least Squares Support Vector Machines, Hypothesis on statistical bootstrap with variance stabilization and a nonparametric kernel density estimator, assisting

  14. Innovative fuel designs for high power density pressurized water reactor

    E-Print Network [OSTI]

    Feng, Dandong, Ph. D. Massachusetts Institute of Technology

    2006-01-01T23:59:59.000Z

    One of the ways to lower the cost of nuclear energy is to increase the power density of the reactor core. Features of fuel design that enhance the potential for high power density are derived based on characteristics of ...

  15. Design of annular fuel for high power density BWRs

    E-Print Network [OSTI]

    Morra, Paolo

    2005-01-01T23:59:59.000Z

    Enabling high power density in the core of Boiling Water Reactors (BWRs) is economically profitable for existing or new reactors. In this work, we examine the potential for increasing the power density in BWR plants by ...

  16. population model Harald Rybka, Jason Wong, Jorge Rivas

    E-Print Network [OSTI]

    Yorke, James

    : food production = food consumption for a population of 8 billion consumption per capita is a constant

  17. Competitive niche: Way of population regulation

    E-Print Network [OSTI]

    Meszéna, Géza

    1 / 27 Competitive niche: Way of population regulation G´eza Mesz´ena1, Andr´as Szil´agyi1, Kalle of coexistence Theory Regulating loop Results Examples Spatial segregation Functional & spatial segregation Regulating loop y Results Examples Conclusions 7 / 27 #12;Regulating loop Introduction Theory y Regulating

  18. The Population Status The American Alligator

    E-Print Network [OSTI]

    Georgia, University of

    Carolina by Thomas M. Murphy A Publication of the Savannah River Plant National Environmental Research Park'S SAVANNAH RIVER PLANT NATIONAL ENVIRONMENT RESEARCH PARK Copies may be obtained from Savannah River Ecology Laboratory #12;- The Population Status of the American Alligator on the Savannah River Plant, South Carolina

  19. Neoclassical formulations of optimum population theory

    E-Print Network [OSTI]

    Davis, Glenn Anthony

    1971-01-01T23:59:59.000Z

    discontinues [ 9, 221] . The modern theory of an optimum population has added three refinements to this notion: (1) there are several optima, and one of these optima is the "optimum-optimorum"; (2) the optima and the optimum-optimorum can be represented...

  20. Evolutionary Game Theory and Population Dynamics

    E-Print Network [OSTI]

    Miekisz, Jacek

    , Poland miekisz@mimuw.edu.pl 1 Short overview We begin these lecture notes by a crash course in game maximizing their individual payoffs and particles in lattice-gas models minimizing their interaction energy by the minimum of some global quantity, the total energy or free energy of the system. Population dynamics lacks

  1. Galaxy populations from Deep ISO Surveys

    E-Print Network [OSTI]

    Seb Oliver

    2001-06-19T23:59:59.000Z

    I discuss some of the main extra-galactic field surveys which have been undertaken by the Infrared Space Observatory (ISO). I review the findings from the source counts analysies and then examine some of the more recent detailed investigations into the explicit nature of the populations that make up these source counts.

  2. Density regulation in annual plant communities under variable resource levels

    E-Print Network [OSTI]

    Novoplansky, Ariel

    Density regulation in annual plant communities under variable resource levels Hagit Shilo. E. and Turkington, R. 2005. Density regulation in annual plant communities under variable resource levels. Á/ Oikos 108: 241Á/252. Density regulation is assumed to be common, but is very rarely tested

  3. Quantum coherent switch utilizing commensurate nanoelectrode and charge density periodicities

    DOE Patents [OSTI]

    Harrison; Neil (Santa Fe, NM), Singleton; John (Los Alamos, NM), Migliori; Albert (Santa Fe, NM)

    2008-08-05T23:59:59.000Z

    A quantum coherent switch having a substrate formed from a density wave (DW) material capable of having a periodic electron density modulation or spin density modulation, a dielectric layer formed onto a surface of the substrate that is orthogonal to an intrinsic wave vector of the DW material; and structure for applying an external spatially periodic electrostatic potential over the dielectric layer.

  4. PROFILE SHAPE PARAMETERIZATION OF JET ELECTRON TEMPERATURE AND DENSITY PROFILES

    E-Print Network [OSTI]

    PROFILE SHAPE PARAMETERIZATION OF JET ELECTRON TEMPERATURE AND DENSITY PROFILES Beatrix Schunke JET Mercer St., New York NY 10012-1185 The temperature and density profiles of the Joint European Torus to determine which terms in the log-linear model to include. The density and temperature profiles

  5. PROFILE SHAPE PARAMETERIZATION OF JET ELECTRON TEMPERATURE AND DENSITY PROFILES

    E-Print Network [OSTI]

    PROFILE SHAPE PARAMETERIZATION OF JET ELECTRON TEMPERATURE AND DENSITY PROFILES Beatrix Schunke JET Mercer St., New York NY 10012­1185 Abstract The temperature and density profiles of the Joint European are used to determine which terms in the log­linear model to include. The density and temperature profiles

  6. Inverse diffusion from knowledge of power densities Guillaume Bal

    E-Print Network [OSTI]

    Bal, Guillaume

    asymptotic expansions and (Fourier) transformation, this allow us to construct the power density) provides access to the power density H(x) = (x)|u|2 (x) for all x inside the domain of interestInverse diffusion from knowledge of power densities Guillaume Bal , Eric Bonnetier , Fran

  7. Different methods for particle diameter determination of low density and high density lipoproteins-Comparison and evaluation 

    E-Print Network [OSTI]

    Vaidyanathan, Vidya

    2009-05-15T23:59:59.000Z

    Predominance of small dense Low Density Lipoprotein (LDL) is associated with a two to threefold increase in risk for Coronary Heart Disease (CVD). Small, dense HDL (High Density Lipoprotein) particles protect small dense LDL from oxidative stress...

  8. Predation, Competition, and Abiotic Disturbance: Population Dynamics of Small Mammals

    SciTech Connect (OSTI)

    Yunger, John A.; /Northern Illinois U. /Northern Illinois U.

    1996-01-01T23:59:59.000Z

    Predation and food availability have been implicated in annual non-cyclic fluctuations of vertebrate prey at mid-latitudes. The timing and magnitude of these factors are unclear due to a lack of large-scale field experiments, little attention to interactions, and a failure to closely link vertebrate predators with their prey. From October 1992 to January 1996, small mammal populations were censused on eight 0.6 ha plots at monthly intervals in a 32-ha prairie restoration at Fermi National Accelerator Laboratory, Illinois. Terrestrial vertebrate predators were excluded after July 1993 from four of the eight plots and canid diets monitored. Both terrestrial and avian vertebrate predators were excluded in March 1994. During 1993 small mammal densities (i.e., Microtus Pennsylvanicus, Peromyscus leucopus, and P. maniculatus) were relatively high. Following peak densities in late summer, Microtus numbers wer 2-3x greater on exclusion plots relative to controls due to preferential selection of Microtus by canids, as reflected in dits. Following an ice-storm and crash in small mammal numbers (particularly Microtus), vertebrate predator exclusion had no detectable effect on P. leucopus numbers, probably due to an abundance of alternative prey (i.e., Sylvilagus floridanus). Meadow vole numbers began to increase in Fall 1995, and a numerical effect of predator exclusion, similar to that in 1993, was observed. Predator exclusion had no detectable effect on the movements and spatial patterns of Microtus during 1993. There was a significant decrease in home range and a significant increase in home range overlap for P. leucopus on the predator exclusion plots. The change in spatial behavior may be due to interspecific competition with Microtus resulting from increased densities on exclusion plots. Thus, predators had an indirect effect on P. leucopus spatial patterns mediated through M. Pennsylvanicus. The role of food limitation was studied using natural and manipulative experiments. Unusually high acorn production in Fall 1994 resulted in increased P. leucopus numbers at one Fermilab site due to immigration since survivorship or reproduction were unaffected. A food supplementation experiment during October 1994-March 1995 induced a strong increase in P. leucopus numbers, due again to immigration, although reproduction also was advanced by two months.

  9. Statistical density modification with non-crystallographic symmetry

    SciTech Connect (OSTI)

    Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Mail Stop M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2002-12-01T23:59:59.000Z

    Statistical density modification can make use of NCS in a crystal and can include estimates of the deviations from perfect NCS. Statistical density modification is a technique for phase improvement through a calculation of the posterior probability of the phases, given experimental phase information and expectations about features of the electron-density map. The technique can take advantage of both estimates of electron density in the map and uncertainties or probability distributions for those estimates. For crystals with non-crystallographic symmetry (NCS), this allows the use of the expected similarity of electron density at NCS-related points without requiring an implicit assumption that these regions are identical.

  10. Gluon condensation and deconfinement critical density in nuclear matter

    E-Print Network [OSTI]

    M. Baldo; P. Castorina; D. Zappala'

    2004-10-07T23:59:59.000Z

    An upper limit to the critical density for the transition to the deconfined phase, at zero temperature, has been evaluated by analyzing the behavior of the gluon condensate in nuclear matter. Due to the non linear baryon density effects, the upper limit to the critical density, \\rho_c turns out about nine times the saturation density, rho_0 for the value of the gluon condensate in vacuum =0.012 GeV^4. For neutron matter \\rho_c \\simeq 8.5 \\rho_0. The dependence of the critical density on the value of the gluon condensate in vacuum is studied.

  11. Balanced homodyne detectors and Casimir energy densities

    E-Print Network [OSTI]

    P. Marecki

    2008-03-22T23:59:59.000Z

    We recall and generalize the analysis of the output of the so-called balanced homodyne detectors. The most important feature of these detectors is their ability to quantify the vacuum fluctuations of the electric field, that is expectation values of products of (quantum-) electric-field operators. More precisely, the output of BHDs provides information on the one- and two-point functions of arbitrary states of quantum fields. We generalize the analysis of the response of BHDs to the case of quantum fields under influence of static external conditions such as cavities or polarizable media. By recalling the expressions for two-point functions of quantum fields in Casimir geometries we show, that a rich, position- and frequency-dependent pattern of BHD responses is predicted for ground states. This points to a potentially new characterization of quantum fields in Casimir setups which would not only complement the current global methods (Casimir forces), but also improve understanding of sub-vacuum energy densities present in some regions in these geometries.

  12. Building a Universal Nuclear Energy Density Functional

    SciTech Connect (OSTI)

    Carlson, Joe A. [Michigan State University; Furnstahl, Dick; Horoi, Mihai; Lust, Rusty; Nazaewicc, Witek; Ng, Esmond; Thompson, Ian; Vary, James

    2012-12-30T23:59:59.000Z

    During the period of Dec. 1 2006 – Jun. 30, 2012, the UNEDF collaboration carried out a comprehensive study of all nuclei, based on the most accurate knowledge of the strong nuclear interaction, the most reliable theoretical approaches, the most advanced algorithms, and extensive computational resources, with a view towards scaling to the petaflop platforms and beyond. The long-term vision initiated with UNEDF is to arrive at a comprehensive, quantitative, and unified description of nuclei and their reactions, grounded in the fundamental interactions between the constituent nucleons. We seek to replace current phenomenological models of nuclear structure and reactions with a well-founded microscopic theory that delivers maximum predictive power with well-quantified uncertainties. Specifically, the mission of this project has been three-fold: ? First, to find an optimal energy density functional (EDF) using all our knowledge of the nucleonic Hamiltonian and basic nuclear properties; ? Second, to apply the EDF theory and its extensions to validate the functional using all the available relevant nuclear structure and reaction data; ? Third, to apply the validated theory to properties of interest that cannot be measured, in particular the properties needed for reaction theory.

  13. Operator pencils on the algebra of densities

    E-Print Network [OSTI]

    A. Biggs; H. M. Khudaverdian

    2014-10-15T23:59:59.000Z

    In this paper we continue to study equivariant pencil liftings and differential operators on the algebra of densities. We emphasize the role that the geometry of the extended manifold plays. Firstly we consider basic examples. We give a projective line of diff($M$)-equivariant pencil liftings for first order operators, and the canonical second order self-adjoint lifting. Secondly we study pencil liftings equivariant with respect to volume preserving transformations. This helps to understand the role of self-adjointness for the canonical pencils. Then we introduce the Duval-Lecomte-Ovsienko (DLO)-pencil lifting which is derived from the full symbol calculus of projective quantisation. We use the DLO-pencil lifting to describe all regular proj-equivariant pencil liftings. In particular the comparison of these pencils with the canonical pencil for second order operators leads to objects related to the Schwarzian. Within this paper the question of whether the pencil lifting factors through a full symbol map naturally arises.

  14. Fabrication Flaw Density and Distribution In Repairs to Reactor Pressure Vessel and Piping Welds

    SciTech Connect (OSTI)

    GJ Schuster, FA Simonen, SR Doctor

    2008-04-01T23:59:59.000Z

    The Pacific Northwest National Laboratory is developing a generalized fabrication flaw distribution for the population of nuclear reactor pressure vessels and for piping welds in U.S. operating reactors. The purpose of the generalized flaw distribution is to predict component-specific flaw densities. The estimates of fabrication flaws are intended for use in fracture mechanics structural integrity assessments. Structural integrity assessments, such as estimating the frequency of loss-of-coolant accidents, are performed by computer codes that require, as input, accurate estimates of flaw densities. Welds from four different reactor pressure vessels and a collection of archived pipes have been studied to develop empirical estimates of fabrication flaw densities. This report describes the fabrication flaw distribution and characterization in the repair weld metal of vessels and piping. This work indicates that large flaws occur in these repairs. These results show that repair flaws are complex in composition and sometimes include cracks on the ends of the repair cavities. Parametric analysis using an exponential fit is performed on the data. The relevance of construction records is established for describing fabrication processes and product forms. An analysis of these records shows there was a significant change in repair frequency over the years when these components were fabricated. A description of repair flaw morphology is provided with a discussion of fracture mechanics significance. Fabrication flaws in repairs are characterized using optimized-access, high-sensitivity nondestructive ultrasonic testing. Flaw characterizations are then validated by other nondestructive evaluation techniques and complemented by destructive testing.

  15. Upgrading of biorenewables to high energy density fuels

    SciTech Connect (OSTI)

    Gordon, John C [Los Alamos National Laboratory; Batista, Enrique R [Los Alamos National Laboratory; Chen, Weizhong [Los Alamos National Laboratory; Currier, Robert P [Los Alamos National Laboratory; Dirmyer, Matthew R [Los Alamos National Laboratory; John, Kevin D [Los Alamos National Laboratory; Kim, Jin K [Los Alamos National Laboratory; Keith, Jason [Los Alamos National Laboratory; Martin, Richard L [Los Alamos National Laboratory; Pierpont, Aaron W [Los Alamos National Laboratory; Silks Ill, L. A. "" Pete [Los Alamos National Laboratory; Smythe, Mathan C [Los Alamos National Laboratory; Sutton, Andrew D [Los Alamos National Laboratory; Taw, Felicia L [Los Alamos National Laboratory; Trovitch, Ryan J [Los Alamos National Laboratory; Vasudevan, Kalyan V [Los Alamos National Laboratory; Waidmann, Christopher R [Los Alamos National Laboratory; Wu, Ruilian [Los Alamos National Laboratory; Baker, R. Thomas [UNIV OF OTTAWWA; Schlaf, Marcel [UNIV OF GUELPH

    2010-12-07T23:59:59.000Z

    According to a recent report, lignocellulose is the most abundant renewable biological resource on earth, with an annual production of {approx} 200 x 10{sup 9} tons. Conversion of lignocellulosics derived from wood, agricultural wastes, and woody grasses into liquid fuels and value-added chemical feedstocks is an active area of research that has seen an explosion of effort due to the need to replace petroleum based sources. The carbohydrates D-glucose (C{sub 6}), L-arabinose (C{sub 5}), and D-xylose (C{sub 5}) are readily obtained from the hydrolysis of lignocellulose and constitute the most abundant renewable organic carbon source on the planet. Because they are naturally produced on such a large scale, these sugars have the greatest potential to displace petrochemical derived transportation fuel. Recent efforts in our laboratories aimed towards the production of high energy density transportation fuels from carbohydrates have been structured around the parameters of selective carbohydrate carbon chain extension chemistries, low reaction temperatures, and the desired use of water or neat substrate as the solvent. Some of our efforts in this regard will be presented.

  16. Computing the moments of the neutron population using deterministic neutron transport

    SciTech Connect (OSTI)

    Fichtl, E. D.; Baker, R. S. [Los Alamos National Laboratory, Computational Physics and Methods, CCS-2, PO Box 1663, Los Alamos, NM, 87544 (United States)

    2013-07-01T23:59:59.000Z

    It is important to treat the inherent stochasticity of the fission process in systems where the behavior of the system is stochastic. This occurs when there are few neutrons in the system, or when the neutron source is weak. In order to characterize such systems, the capability to compute the first four moments of the neutron population distribution has been added to the deterministic neutral particle transport code, PARTISN. The moments are then fitted to probability density functions from the Pearson family. PARTISN is compared against MCNP6, with which it agrees well. (authors)

  17. ACTIVE CATHODES FOR SUPER-HIGH POWER DENSITY SOLID OXIDE FUEL CELLS THROUGH SPACE CHARGE EFFECTS

    SciTech Connect (OSTI)

    Anil V. Virkar

    2004-05-17T23:59:59.000Z

    This report summarizes the work done during the sixth quarter of the project. Effort was directed in three areas: (1) Further development of the model on the role of connectivity on ionic conductivity of porous bodies, including the role of grain boundaries and space charge region. (2) Calculation of the effect of space charge and morphology of porous bodies on the effective charge transfer resistance of porous composite cathodes. (3) The investigation of the three electrode system for the measurement of cathodic polarization using amperometric sensors.

  18. Copper nanocrystal modified activated carbon for supercapacitors with enhanced volumetric energy and power density

    E-Print Network [OSTI]

    Cao, Guozhong

    capacitors (EDLCs) have evoked wide interest in recent years due to their ability to supply high power of EDLCs is based on the quick formation of a double layer of surface charges and counter materials for EDLCs should have large surface area to accumulate a large amount of charges, and a size

  19. Sulfurized activated carbon for high energy density supercapacitors Yunxia Huang a,b

    E-Print Network [OSTI]

    Cao, Guozhong

    electric double layer capacitors (EDLCs) or pseudo-capacitors. The former is based on the accumulation

  20. Peroxisome Proliferator-activated Receptor / Regulates Very Low Density Lipoprotein Production and Catabolism in

    E-Print Network [OSTI]

    Omiecinski, Curtis

    in PPAR -null mice on a HF diet, both proteins of which have recently been shown to inhibit lipoprotein and Catabolism in Mice on a Western Diet* Received for publication, November 24, 2003, and in revised form of mice lacking a func- tional PPAR receptor were determined. PPAR -null mice maintained on either normal

  1. ACTIVE CONTROL STRATEGY FOR DENSITY-WAVE IN GAS-LIFTED WELLS

    E-Print Network [OSTI]

    (point A), then goes down into the annular space between the drilling pipe (casing, point B with possible facilities dam- ages. The best identified instability is the "casing- heading". It consists in the tubing at a given set-point. In practice, under the assumption of a constant well #12;head gas (in

  2. Bacterial Population Genetics in a Forensic Context

    SciTech Connect (OSTI)

    Velsko, S P

    2009-11-02T23:59:59.000Z

    This report addresses the recent Department of Homeland Security (DHS) call for a Phase I study to (1) assess gaps in the forensically relevant knowledge about the population genetics of eight bacterial agents of concern, (2) formulate a technical roadmap to address those gaps, and (3) identify new bioinformatics tools that would be necessary to analyze and interpret population genetic data in a forensic context. The eight organisms that were studied are B. anthracis, Y. pestis, F. tularensis, Brucella spp., E. coli O157/H7, Burkholderia mallei, Burkholderia pseudomallei, and C. botulinum. Our study focused on the use of bacterial population genetics by forensic investigators to test hypotheses about the possible provenance of an agent that was used in a crime or act of terrorism. Just as human population genetics underpins the calculations of match probabilities for human DNA evidence, bacterial population genetics determines the level of support that microbial DNA evidence provides for or against certain well-defined hypotheses about the origins of an infecting strain. Our key findings are: (1) Bacterial population genetics is critical for answering certain types of questions in a probabilistic manner, akin (but not identical) to 'match probabilities' in DNA forensics. (2) A basic theoretical framework for calculating likelihood ratios or posterior probabilities for forensic hypotheses based on microbial genetic comparisons has been formulated. This 'inference-on-networks' framework has deep but simple connections to the population genetics of mtDNA and Y-STRs in human DNA forensics. (3) The 'phylogeographic' approach to identifying microbial sources is not an adequate basis for understanding bacterial population genetics in a forensic context, and has limited utility, even for generating 'leads' with respect to strain origin. (4) A collection of genotyped isolates obtained opportunistically from international locations augmented by phylogenetic representations of relatedness will not and enzootic outbreaks noted through international outbreak surveillance systems, and 'representative' genetic sequences from each outbreak. (5) Interpretation of genetic comparisons between an attack strain and reference strains requires a model for the network structure of maintenance foci, enzootic outbreaks, and human outbreaks of that disease, coupled with estimates of mutational rate constants. Validation of the model requires a set of sequences from exemplary outbreaks and laboratory data on mutation rates during animal passage. The necessary number of isolates in each validation set is determined by disease transmission network theory, and is based on the 'network diameter' of the outbreak. (6) The 8 bacteria in this study can be classified into 4 categories based on the complexity of the transmission network structure of their natural maintenance foci and their outbreaks, both enzootic and zoonotic. (7) For B. anthracis, Y. pestis, E. coli O157, and Brucella melitensis, and their primary natural animal hosts, most of the fundamental parameters needed for modeling genetic change within natural host or human transmission networks have been determined or can be estimated from existing field and laboratory studies. (8) For Burkholderia mallei, plausible approaches to transmission network models exist, but much of the fundamental parameterization does not. In addition, a validated high-resolution typing system for characterizing genetic change within outbreaks or foci has not yet been demonstrated, although a candidate system exists. (9) For Francisella tularensis, the increased complexity of the transmission network and unresolved questions about maintenance and transmission suggest that it will be more complex and difficult to develop useful models based on currently available data. (10) For Burkholderia pseudomallei and Clostridium botulinum, the transmission and maintenance networks involve complex soil communities and metapopulations about which very little is known. It is not clear that these pathogens can be brought into the in

  3. Design exploration: engaging a larger user population

    E-Print Network [OSTI]

    Moore, John Michael

    2009-06-02T23:59:59.000Z

    an interface on a physical shared table space. Whereas PICTIVE requires physical co-location, TelePICTIVE [Miller et al. 1992] and PICTIOL [Farrell et al. 2006] moves the shared space to a collaborative computer application. While GUI developers are still... of DOCTOR OF PHILOSOPHY August 2007 Major Subject: Computer Science DESIGN EXPLORATION: ENGAGING A LARGER USER POPULATION A Dissertation by JOHN MICHAEL MOORE Submitted to the Office of Graduate Studies of Texas A&M University...

  4. Lesson 1: Data Types and Watershed Populations In this first lesson, you will discover some information about each of the two watersheds

    E-Print Network [OSTI]

    of people per block. This is a good summary of how many people are in the watershed and where they live the condition of the watersheds regarding how people are currently living on and using the land. We will use Arc watershed (2000 census), the population density (average number of people per hectare), and to visualize how

  5. Secondary Energy Infobook Activities (19 Activities) | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOriginEducationVideo »Usage »DownloadSolar »MiddleHighHighEnergy SourcesSec.Activities (19

  6. Secondary Energy Infobook and Secondary Infobook Activities (19 Activities)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOriginEducationVideo »Usage »DownloadSolar »MiddleHighHighEnergy SourcesSec.Activities (19|

  7. WANDERING STARS: AN ORIGIN OF ESCAPED POPULATIONS

    SciTech Connect (OSTI)

    Teyssier, Maureen; Johnston, Kathryn V. [Department of Astronomy, Columbia University, Pupin Physics Laboratory, 550 West 120th Street, New York, NY 10027 (United States); Shara, Michael M. [American Museum of Natural History, 79th Street and Central Park West, New York, NY 10024-5192 (United States)

    2009-12-10T23:59:59.000Z

    We demonstrate that stars beyond the virial radii of galaxies may be generated by the gravitational impulse received by a satellite as it passes through the pericenter of its orbit around its parent. These stars may become energetically unbound (escaped stars), or may travel to further than a few virial radii for longer than a few Gyr, but still remain energetically bound to the system (wandering stars). Larger satellites (10%-100% the mass of the parent), and satellites on more radial orbits are responsible for the majority of this ejected population. Wandering stars could be observable on Mpc scales via classical novae, and on 100 Mpc scales via Type Ia supernova. The existence of such stars would imply a corresponding population of barely bound, old, high-velocity stars orbiting the Milky Way, generated by the same physical mechanism during the Galaxy's formation epoch. Sizes and properties of these combined populations should place some constraints on the orbits and masses of the progenitor objects from which they came, providing insight into the merging histories of galaxies in general and the Milky Way in particular.

  8. Photodissociation feedback of Population III stars \\\\on their neighbor prestellar cores

    E-Print Network [OSTI]

    Hajime Susa

    2007-01-08T23:59:59.000Z

    We investigate the star formation process in primordial environment in the presence of radiative feedback by other population III stars formed earlier. In this paper, we focus our attention on the effects by photodissociative radiation toward the full understanding of the radiative feedback effects. We perform three dimensional radiation hydrodynamics simulations on this issue as well as analytic estimates, paying special attention on the self-shielding effect and dynamics of the star-forming cloud. As a result, we find that the ignition timing of the source star is crucial. If the ignition is later than the epoch when the central density of the collapsing cloud exceeds $\\sim 10^3-10^4{\\rm cm^{-3}}$, the collapse cannot be reverted, even if the source star is located at $\\la$ 100pc. The uncertainty of the critical density comes from the variety of initial conditions of the collapsing cloud. We also find the analytic criteria for a cloud to collapse with given central density, temperature and the Lyman-Werner(LW) band flux which irradiates the cloud. Although we focus on the radiation from neighbor stars, this result can also be applied to the effects of diffuse LW radiation field, that is expected to be built up prior to the reionization of the universe. We find that self-gravitating clouds can easily self-shield from diffuse LW radiation and continue their collapse for densities larger than $\\sim 10^3 {\\rm cm^{-3}}$.

  9. Population inversion in a magnetized hydrogen plasma expansion as a consequence of the molecular mutual neutralization process

    SciTech Connect (OSTI)

    Harskamp, W. E. N. van; Brouwer, C. M.; Schram, D. C.; Sanden, M. C. M. van de; Engeln, R. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, NL-5600 MB Eindhoven (Netherlands)

    2011-03-15T23:59:59.000Z

    A weakly magnetized expanding hydrogen plasma, created by a cascaded arc, was investigated using optical emission spectroscopy. The emission of the expanding plasma is dominated by H{sub {alpha}} emission in the first part of the plasma expansion, after which a sharp transition to a blue afterglow is observed. The position of this sharp transition along the expansion axis depends on the magnetic field strength. The blue afterglow emission is associated with population inversion of the electronically excited atomic hydrogen states n=4-6 with respect to n=3. By comparing the measured densities with the densities using an atomic collisional radiative model, we conclude that atomic recombination processes cannot account for the large population densities observed. Therefore, molecular processes must be important for the formation of excited states and for the occurrence of population inversion. This is further corroborated at the transition from red to blue, where a hollow profile of the excited states n=4-6 in the radial direction is observed. This hollow profile is explained by the molecular mutual neutralization process of H{sub 2}{sup +} with H{sup -}, which has a maximum production for excited atomic hydrogen 1-2 cm outside the plasma center.

  10. Development of frequency modulated continuous wave reflectometer for electron density profile measurement on the HL-2A tokamak

    SciTech Connect (OSTI)

    Zhong, W. L., E-mail: zhongwl@swip.ac.cn; Shi, Z. B.; Liu, Z. T.; Chen, W.; Jiang, M.; Li, J.; Cui, Z. Y.; Song, X. M.; Chen, L. Y.; Ding, X. T.; Liu, Yi; Yan, L. W.; Yang, Q. W.; Duan, X. R. [Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041 (China)] [Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041 (China); Huang, X. L. [Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041 (China) [Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041 (China); Department of Fusion Science, Graduate University for Advanced Studies, Toki 509-5292 (Japan); Zou, X. L. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France)] [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France)

    2014-01-15T23:59:59.000Z

    The frequency modulated continuous wave reflectometer was developed for the first time on the HL-2A tokamak. The system utilizes a voltage controlled oscillator and an active multiplier for broadband coverage and detects as heterodyne mode. Three reflectometers have been installed and operated in extraordinary mode polarization on HL-2A to measure density profiles at low field side, covering the Q-band (33–50 GHz), V-band (50–75 GHz), and W-band (75–110 GHz). For density profile reconstruction from the phase shift of the probing wave, a corrected phase unwrapping method is introduced in this article. The effectiveness of the method is demonstrated. The density profile behavior of a fast plasma event is presented and it demonstrates the capability of the reflectometer. These diagnostics will be contributed to the routine density profile measurements and the plasma physics study on HL-2A.

  11. Structural and electronic properties of cobalt carbide Co2C and its surface stability: Density functional theory study

    E-Print Network [OSTI]

    Li, Weixue

    in Fischer­Tropsch syn- thesis, which agrees well with experimental findings. The density of states (DOSs­14], dehydrogenation [15], hydrogenolysis [16, 17] and Fischer­Tropsch synthesis (FTS) [18­22] etc., approaching activity of cobalt, iron and iron carbide in Fischer­Tropsch synthesis (FTS)[24­43], relative little

  12. Collective dynamics of active filament complexes

    E-Print Network [OSTI]

    Nogucci, Hironobu

    2015-01-01T23:59:59.000Z

    Networks of biofilaments are essential for the formation of cellular structures and they support various biological functions. Previous studies have largely investigated the collective dynamics of rod-like biofilaments; however, the shapes of actual subcelluar componensts are often more elaborate. In this study, we investigated an active object composed of two active filaments, which represents a progression from rod-like biofilaments to complex-shaped biofilaments. Specifically, we numerically assessed the collective behaviors of these active objects and observed several types of dynamics depending on the density and the angle of the two filaments as shape parameters of the object. Among the observed collective dynamics, moving density bands that we named 'moving smectic' are reported here for the first time. By using statistical analyses of the orbits of individual objects and the interactions among them, the mechanisms underlying the rise of these dynamics patterns in the system were determined. This study...

  13. Accretion and nuclear activity of quiescent supermassive black holes. I: X-ray study

    E-Print Network [OSTI]

    Roberto Soria; Giuseppina Fabbiano; Alister W. Graham; Alessandro Baldi; Martin Elvis; Helmut Jerjen; Silvia Pellegrini; Aneta Siemiginowska

    2005-11-10T23:59:59.000Z

    We have studied the nuclear activity in a sample of six quiescent early-type galaxies, with new Chandra data and archival HST optical images. Their nuclear sources have X-ray luminosities ~ 10^{38} - 10^{39} erg/s (L_X/L_Edd ~ 10^{-8} - 10^{-7}), and colors or spectra consistent with accreting supermassive black holes (SMBHs)--except for the nucleus of NGC 4486B, which is softer than typical AGN spectra. In a few cases, the X-ray morphology of the nuclear sources shows hints of marginally extended structures, in addition to the surrounding diffuse thermal emission from hot gas, which is detectable on scales >~ 1 kpc. In one case (NGC 5845), a dusty disk may partially obstruct our direct view of the SMBH. We have estimated the temperature and density of the hot interstellar medium, which is one major source of fuel for the accreting SMBH; typical central densities are n_e ~ (0.02 +/- 0.01) cm^{-3}. Assuming that the hot gas is captured by the SMBH at the Bondi rate, we show that the observed X-ray luminosities are too faint to be consistent with standard disk accretion, but brighter than predicted by radiatively-inefficient solutions (eg, ADAF). In total, there are ~ 20 galaxies for which SMBH mass, hot gas density, and nuclear X-ray luminosity are simultaneously known. In some cases, the nuclear sources are brighter than predicted by the ADAF model; in other cases, they are consistent or fainter. We discuss the apparent lack of correlations between Bondi rate and X-ray luminosity, and suggest that, in order to understand the observed distribution, we need to know two additional parameters: the amount of gas supplied by the stellar population inside the accretion radius, and the fraction (possibly << 1) of the total gas available that is accreted by the SMBH. We shall discuss these issues in our Paper II.

  14. Textured-surface quartz resonator fluid density and viscosity monitor

    DOE Patents [OSTI]

    Martin, Stephen J. (Albuquerque, NM); Wiczer, James J. (Albuquerque, NM); Cernosek, Richard W. (Albuquerque, NM); Frye, Gregory C. (Cedar Crest, NM); Gebert, Charles T. (Albuquerque, NM); Casaus, Leonard (Bernalillo, NM); Mitchell, Mary A. (Tijeras, NM)

    1998-08-25T23:59:59.000Z

    A pair of thickness-shear mode resonators, one smooth and one with a textured surface, allows fluid density and viscosity to be independently resolved. A textured surface, either randomly rough or regularly patterned, leads to trapping of liquid at the device surface. The synchronous motion of this trapped liquid with the oscillating device surface allows the device to weigh the liquid; this leads to an additional response that depends on liquid density. This additional response enables a pair of devices, one smooth and one textured, to independently resolve liquid density and viscosity; the difference in responses determines the density while the smooth device determines the density-viscosity product, and thus, the pair determines both density and viscosity.

  15. Electron density and carriers of the diffuse interstellar bands

    E-Print Network [OSTI]

    P. Gnacinski; J. K. Sikorski; G. A. Galazutdinov

    2007-02-07T23:59:59.000Z

    We have used the ionisation equilibrium equation to derive the electron density in interstellar clouds in the direction to 13 stars. A linear relation was found, that allows the determination of the electron density from the Mg I and Mg II column densities in diffuse clouds. The comparison of normalised equivalent width of 12 DIBs with the electron density shows that the DIBs equivalent width do not change with electron density varying in the range ne=0.01-2.5 cm^-3. Therefore the DIBs carriers (1) can be observed only in one ionisation stage, or (2) the DIBs are arising in cloud regions (eg. cores or cloud coronas) for which we can not determine the electron density.

  16. Nuclear symmetry energy at subnormal densities from measured nuclear masses

    E-Print Network [OSTI]

    Min Liu; Ning Wang; Zhuxia Li; Fengshou Zhang

    2010-11-17T23:59:59.000Z

    The symmetry energy coefficients for nuclei with mass number A=20~250 are extracted from more than 2000 measured nuclear masses. With the semi-empirical connection between the symmetry energy coefficients of finite nuclei and the nuclear symmetry energy at reference densities, we investigate the density dependence of symmetry energy of nuclear matter at subnormal densities. The obtained results are compared with those extracted from other methods.

  17. High-Precision Thermodynamics and Hagedorn Density of States

    E-Print Network [OSTI]

    Harvey B. Meyer

    2009-05-26T23:59:59.000Z

    We compute the entropy density of the confined phase of QCD without quarks on the lattice to very high accuracy. The results are compared to the entropy density of free glueballs, where we include all the known glueball states below the two-particle threshold. We find that an excellent, parameter-free description of the entropy density between 0.7Tc and Tc is obtained by extending the spectrum with the exponential spectrum of the closed bosonic string.

  18. Method for measuring the density of lightweight materials

    DOE Patents [OSTI]

    Snow, Samuel G. (Oak Ridge, TN); Giacomelli, Edward J. (Knoxville, TN)

    1980-01-01T23:59:59.000Z

    This invention relates to a nondestructive method for measuring the density of articles composed of elements having a low atomic number such as plastic and carbon composites. The measurement is accomplished by striking the article with a collimated beam of X radiation, simultaneously monitoring the radiation scattered and the radiation transmitted by the article, then relating the ratio of the radiation scattered to the radiation transmitted with the density of the article. The above method is insensitive to all variables except density.

  19. The interactive effects of pH, surface tension, and solution density for flotation systems for separation of equivalent-density materials: separation of ABS from HIPS

    SciTech Connect (OSTI)

    Karvelas, D.E.; Jody, B.J.; Pomykala, J.A.; Daniels, E.J.

    1996-07-01T23:59:59.000Z

    This paper presents the results of research being conducted at Argonne National Laboratory, to develop a cost-effective and environmentally acceptable process for the separation of high-value plastics from discarded household appliances. The process under development has separated high-purity (greater than 99.5%) acrylonitrile-butadiene-styrene (ABS) and high-impact polystyrene (HIPS) from commingled plastics generated by appliance-shredding and metal recovery operations. Plastics of similar densities, such as ABS and HIPS are further separated by using a chemical solution. By controlling the surface tension, the density and the temperature of the chemical solution, we are able to selectively float/separate plastics that have equivalent densities. In laboratory-scale tests, this technique has proven highly effective in recovering high-purity plastics materials from discarded household appliances and other obsolete durable goods. A pilot plant is under construction to demonstrate and assess the technical and economic performance of this process. In this paper, we examine the technical and economic issues that affect the recovery and separation of plastics and provide an update on Argonne`s plastics separation research and development activities.

  20. Density-dependent acoustic properties of PBX 9502

    SciTech Connect (OSTI)

    Brown, Geoffrey W [Los Alamos National Laboratory; Thompson, Darla G [Los Alamos National Laboratory; Deluca, Racci [Los Alamos National Laboratory; Hartline, Ernest L [Los Alamos National Laboratory; Hagelberg, Stephanie I [Los Alamos National Laboratory

    2009-07-31T23:59:59.000Z

    We have measured the longitudinal and shear acoustic velocities of PBX 9502 as a function of density for die-pressed samples over the range 1.795 g/cc to 1.888 g/cc. The density dependence of the velocities is linear. Thermal cycling of PBX 9502 is known to induce irreversible volume growth. We have measured this volume growth dependence on density for a subset of the pressed parts and find that the most growth occurs for the samples with lowest initial density. The acoustic velocity changes due to the volume growth are significant and reflect damage in the samples.

  1. COLD BUBBLE FORMATION DURING TOKAMAK DENSITY LIMIT DISRUPTIONS

    E-Print Network [OSTI]

    Howard, John

    COLD BUBBLE FORMATION DURING TOKAMAK DENSITY LIMIT DISRUPTIONS J. HOWARD, M. PERSSON* Plasma Research Laboratory, Research School of Physical Sciences, Australian National University, Canberra

  2. Polymer Electrolytes for High Energy Density Lithium Batteries

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

    Electrolytes for High Energy Density Lithium Batteries Ashoutosh Panday Scott Mullin Nitash Balsara Proposed Battery anode (Li metal) Li Li + + e - e - Li salt in a hard solid...

  3. Engineering Density of States of Earth Abundant Semiconductors...

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

    of States of Earth Abundant Semiconductors for Enhanced Thermoelectric Power Factor Engineering Density of States of Earth Abundant Semiconductors for Enhanced Thermoelectric...

  4. A Comprehensive Study Of Fracture Patterns And Densities In The...

    Open Energy Info (EERE)

    Patterns And Densities In The Geysers Geothermal Reservoir Using Microearthquake Shear-Wave Splitting Tomography Jump to: navigation, search OpenEI Reference LibraryAdd to library...

  5. Inexpensive Production of High Density Thin Ceramic Films on...

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

    Inexpensive Production of High Density Thin Ceramic Films on Rigid or Porous Substrates Lawrence Berkeley National Laboratory Contact LBL About This Technology Technology Marketing...

  6. SciTech Connect: Chiral dynamics and peripheral transverse densities

    Office of Scientific and Technical Information (OSTI)

    in terms of frame-independent charge and magnetization densities in transverse space. This formulation allows one to identify the chiral components of nucleon structure as...

  7. Developing a Lower Cost and Higher Energy Density Alternative...

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

    Protected Lithium Electrodes for Advanced Batteries ADVANCED MANUFACTURING OFFICE Developing a Lower Cost and Higher Energy Density Alternative to Lithium-Ion Batteries...

  8. ATMOSPHERIC DENSITY ESTIMATION USING SATELLITE PRECISION ORBIT EPHEMERIDES

    E-Print Network [OSTI]

    Arudra, Anoop Kumar

    2011-04-22T23:59:59.000Z

    ..................................................................................... 92 4.5.2 Density and Ballistic Coefficient Correlated Half-life Variation. ............................. 92 5 SUMMARY, CONCLUSIONS AND FUTURE WORK .............................. 93 5.1 Summary...

  9. Density Functional Theory Studies of the Electronic Structure...

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

    Theory Studies of the Electronic Structure of Solid State Actinide Oxides. Density Functional Theory Studies of the Electronic Structure of Solid State Actinide Oxides. Abstract:...

  10. Distributions of Fourier modes of cosmological density fields

    SciTech Connect (OSTI)

    Fan, Z.; Bardeen, J.M. [Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States)] [Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States)

    1995-06-15T23:59:59.000Z

    We discuss the probability distributions of Fourier modes of cosmological density fields using the central limit theorem is it applies to weighted integrals of random fields. It is shown that if the cosmological principle holds in a certain sense, i.e., the Universe approaches homogeneity and isotropy sufficiently rapidly on very large scales, the one-point distribution of each Fourier mode of the density field is Gaussian whether or not the density field itself is Gaussian. Therefore, one-point distributions of the power spectrum obtained from observational data or from simulations are not a good test of whether the density field is Gaussian.

  11. Linking Dynamical and Population Genetic Models of Persistent Viral Infection

    E-Print Network [OSTI]

    Kelly, John K.; Williamson, Scott; Orive, Maria E.; Smith, Marilyn S.; Holt, Robert D.

    2003-07-01T23:59:59.000Z

    This article develops a theoretical framework to link dynamical and population genetic models of persistent viral infection. This linkage is useful because, while the dynamical and population genetic theories have developed ...

  12. Diversity waves in collapse-driven population dynamics

    E-Print Network [OSTI]

    Maslov, Sergei

    2015-01-01T23:59:59.000Z

    Populations of species in ecosystems are constrained by the availability of resources within their environment. In effect this means that a growth of one population, needs to be balanced by the reduction in size of others. In neutral models of biodiversity all populations are assumed to change incrementally due to stochastic births and deaths of individuals. Here we propose and model another redistribution mechanism driven by abrupt collapses of the entire population of a single species freeing up resources for the remaining ones. This mechanism may be relevant for communities of bacteria, with strain-specific collapses caused e.g. by invading bacteriophages, or for other ecosystems where infectious diseases play an important role. The emergent property of the population dynamics in our system are cyclic "diversity waves" triggered by collapses of globally dominating populations. The population diversity in the environment peaks at the beginning of each wave and exponentially decreases afterwards. Population ...

  13. autotrophic microbial populations: Topics by E-print Network

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

    18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 MICROBIAL POPULATIONS FECAL PELLETS AND Geosciences Websites Summary: MICROBIAL POPULATIONS FECAL PELLETS AND AND...

  14. access microbial populations: Topics by E-print Network

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

    18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 MICROBIAL POPULATIONS FECAL PELLETS AND Geosciences Websites Summary: MICROBIAL POPULATIONS FECAL PELLETS AND AND...

  15. Evolutionary dynamics in set structured populations Corina E. Tarnitaa

    E-Print Network [OSTI]

    Nowak, Martin A.

    Evolutionary dynamics in set structured populations Corina E. Tarnitaa , Tibor Antala , Hisashi a powerful method to study dynamical population structure: evolutionary set theory. The individuals of popu- lation structure on evolutionary and ecological dynamics. These approaches include spatial models

  16. Tubulin cofactor B regulates microtubule densities during microglia transition to the reactive states

    SciTech Connect (OSTI)

    Fanarraga, M.L. [Departamentos de Biologia Molecular, Universidad de Cantabria, IFIMAV. Herrera Oria s/n. 39011, Santander (Spain)], E-mail: fanarrag@unican.es; Villegas, J.C. [Anatomia y Biologia Celular, Universidad de Cantabria, IFIMAV. Herrera Oria s/n. 39011, Santander (Spain); Carranza, G.; Castano, R.; Zabala, J.C. [Departamentos de Biologia Molecular, Universidad de Cantabria, IFIMAV. Herrera Oria s/n. 39011, Santander (Spain)

    2009-02-01T23:59:59.000Z

    Microglia are highly dynamic cells of the CNS that continuously survey the welfare of the neural parenchyma and play key roles modulating neurogenesis and neuronal cell death. In response to injury or pathogen invasion parenchymal microglia transforms into a more active cell that proliferates, migrates and behaves as a macrophage. The acquisition of these extra skills implicates enormous modifications of the microtubule and actin cytoskeletons. Here we show that tubulin cofactor B (TBCB), which has been found to contribute to various aspects of microtubule dynamics in vivo, is also implicated in microglial cytoskeletal changes. We find that TBCB is upregulated in post-lesion reactive parenchymal microglia/macrophages, in interferon treated BV-2 microglial cells, and in neonate amoeboid microglia where the microtubule densities are remarkably low. Our data demonstrate that upon TBCB downregulation both, after microglia differentiation to the ramified phenotype in vivo and in vitro, or after TBCB gene silencing, microtubule densities are restored in these cells. Taken together these observations support the view that TBCB functions as a microtubule density regulator in microglia during activation, and provide an insight into the understanding of the complex mechanisms controlling microtubule reorganization during microglial transition between the amoeboid, ramified, and reactive phenotypes.

  17. LandScan USA: A High Resolution Geospatial and Temporal Modeling Approach for Population Distribution and Dynamics

    SciTech Connect (OSTI)

    Bhaduri, Budhendra L [ORNL; Bright, Eddie A [ORNL; Coleman, Phil R [ORNL; Urban, Marie L [ORNL

    2007-01-01T23:59:59.000Z

    High resolution population distribution data are critical for successfully addressing important issues ranging from socio-environmental research to public health to homeland security, since scientific analyses, operational activities, and policy decisions are significantly influenced by the number of impacted people. Dasymetric modeling has been a well recognized approach for spatial decomposition of census data to increase the spatial resolution of population distribution. However, enhancing the temporal resolution of population distribution poses a greater challenge. In this paper, we discuss the development of LandScan USA, a multi-dimensional dasymetric modeling approach, which has allowed creation of very high resolution population distribution data both over space and time. At a spatial resolution of 3 arc seconds (~90m), the initial LandScan USA database contains both a nighttime residential as well as a baseline daytime population distribution that incorporates movement of workers and students. Challenging research issues of disparate and misaligned spatial data integration and modeling to develop a database at a national scale, as well as model verification and validation approaches are illustrated and discussed. Initial analyses indicate a high degree of accuracy for LandScan USA distribution model and data. High resolution population data such as LandScan USA, which describes both distribution and dynamics of human population, clearly has the potential to profoundly impact on multiple domain applications of national and global priority.

  18. assessing population genetic: Topics by E-print Network

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

    to random sampling effects Durrett, Richard 5 Population genetics Opinion piece Environmental Management and Restoration Websites Summary: ; optimization 1. INTRODUCTION...

  19. Power-law tails in probability density functions of molecular cloud column density

    E-Print Network [OSTI]

    Brunt, Chris

    2015-01-01T23:59:59.000Z

    Power-law tails are often seen in probability density functions (PDFs) of molecular cloud column densities, and have been attributed to the effect of gravity. We show that extinction PDFs of a sample of five molecular clouds obtained at a few tenths of a parsec resolution, probing extinctions up to A$_{{\\mathrm{V}}}$ $\\sim$ 10 magnitudes, are very well described by lognormal functions provided that the field selection is tightly constrained to the cold, molecular zone and that noise and foreground contamination are appropriately accounted for. In general, field selections that incorporate warm, diffuse material in addition to the cold, molecular material will display apparent core+tail PDFs. The apparent tail, however, is best understood as the high extinction part of a lognormal PDF arising from the cold, molecular part of the cloud. We also describe the effects of noise and foreground/background contamination on the PDF structure, and show that these can, if not appropriately accounted for, induce spurious ...

  20. Emergence of Attention within a Neural Population

    E-Print Network [OSTI]

    We present a dynamic model of attention based on the Continuum Neural Field Theory that explains attention as being an emergent property of a neural population. This model is experimentally proved to be very robust and able to track one static or moving target in the presence of very strong noise or in the presence of a lot of distractors, even more salient than the target. This attentional property is not restricted to the visual case and can be considered as a generic attentional process of any spatio-temporal continuous input.

  1. VOL I, ISSUE 1Quarterly Edition Population and Public Policy

    E-Print Network [OSTI]

    Saskatchewan, University of

    VOL I, ISSUE 1Quarterly Edition Population and Public Policy Migration to western Canada increases affect and are affected by public policy decisions. Even the sheer size of the population, the subject of this article, affects public policy because larger populations can usually support a wider range of public

  2. Proximate Population Factors and Deforestation in Tropical Agricultural Frontiers

    E-Print Network [OSTI]

    Lopez-Carr, David

    Proximate Population Factors and Deforestation in Tropical Agricultural Frontiers David L. Carr are significantly associated at the global and regional scales, evidence for population links to deforestation of thought on population­environment theories relevant to deforestation in tropical agricultural frontiers

  3. Plasma ionization frequency, edge-to-axis density ratio, and density on axis of a cylindrical gas discharge

    SciTech Connect (OSTI)

    Palacio Mizrahi, J. H. [Physics Department, Technion, Haifa 32000 (Israel)

    2014-06-15T23:59:59.000Z

    A rigorous derivation of expressions, starting from the governing equations, for the ionization frequency, edge-to-axis ratio of plasma density, plasma density at the axis, and radially averaged plasma density in a cylindrical gas discharge has been obtained. The derived expressions are simple and involve the relevant parameters of the discharge: Cylinder radius, axial current, and neutral gas pressure. The found expressions account for ion inertia, ion temperature, and changes in plasma ion collisionality.

  4. Symmetry energy systematics and its high density behavior

    E-Print Network [OSTI]

    Lie-Wen Chen

    2015-06-30T23:59:59.000Z

    We explore the systematics of the density dependence of nuclear matter symmetry energy in the ambit of microscopic calculations with various energy density functionals, and find that the symmetry energy from subsaturation density to supra-saturation density can be well determined by three characteristic parameters of the symmetry energy at saturation density $\\rho_0 $, i.e., the magnitude $E_{\\text{sym}}({\\rho_0 })$, the density slope $L$ and the density curvature $K_{\\text{sym}}$. This finding opens a new window to constrain the supra-saturation density behavior of the symmetry energy from its (sub-)saturation density behavior. In particular, we obtain $L=46.7 \\pm 12.8$ MeV and $K_{\\text{sym}}=-166.9 \\pm 168.3$ MeV as well as $E_{\\text{sym}}({2\\rho _{0}}) \\approx 40.2 \\pm 12.8$ MeV and $L({2\\rho _{0}}) \\approx 8.9 \\pm 108.7$ MeV based on the present knowledge of $E_{\\text{sym}}({\\rho_{0}}) = 32.5 \\pm 0.5$ MeV, $E_{\\text{sym}}({\\rho_c}) = 26.65 \\pm 0.2$ MeV and $L({\\rho_c}) = 46.0 \\pm 4.5$ MeV at $\\rho_{\\rm{c}}= 0.11$ fm$^{-3}$ extracted from nuclear mass and the neutron skin thickness of Sn isotopes. Our results indicate that the symmetry energy cannot be stiffer than a linear density dependence.In addition, we also discuss the quark matter symmetry energy since the deconfined quarks could be the right degree of freedom in dense matter at high baryon densities.

  5. Ligand identification using electron-density map correlations

    SciTech Connect (OSTI)

    Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM 87545 (United States); Adams, Paul D.; Moriarty, Nigel W. [Lawrence Berkeley National Laboratory, One Cyclotron Road, BLDG 64R0121, Berkeley, CA 94720 (United States); Cohn, Judith D. [Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM 87545 (United States)

    2007-01-01T23:59:59.000Z

    An automated ligand-fitting procedure is applied to (F{sub o} ? F{sub c})exp(i?{sub c}) difference density for 200 commonly found ligands from macromolecular structures in the Protein Data Bank to identify ligands from density maps. A procedure for the identification of ligands bound in crystal structures of macromolecules is described. Two characteristics of the density corresponding to a ligand are used in the identification procedure. One is the correlation of the ligand density with each of a set of test ligands after optimization of the fit of that ligand to the density. The other is the correlation of a fingerprint of the density with the fingerprint of model density for each possible ligand. The fingerprints consist of an ordered list of correlations of each the test ligands with the density. The two characteristics are scored using a Z-score approach in which the correlations are normalized to the mean and standard deviation of correlations found for a variety of mismatched ligand-density pairs, so that the Z scores are related to the probability of observing a particular value of the correlation by chance. The procedure was tested with a set of 200 of the most commonly found ligands in the Protein Data Bank, collectively representing 57% of all ligands in the Protein Data Bank. Using a combination of these two characteristics of ligand density, ranked lists of ligand identifications were made for representative (F{sub o} ? F{sub c})exp(i?{sub c}) difference density from entries in the Protein Data Bank. In 48% of the 200 cases, the correct ligand was at the top of the ranked list of ligands. This approach may be useful in identification of unknown ligands in new macromolecular structures as well as in the identification of which ligands in a mixture have bound to a macromolecule.

  6. Experimental investigation on the temperature dependence of the nuclear level density parameter

    E-Print Network [OSTI]

    Dey, Balaram; Bhattacharya, Srijit; Banerjee, K; Hung, N Quang; Dang, N Dinh; Mondal, Debasish; Mukhopadhyay, S; Pal, Surajit; De, A; Banerjee, S R

    2015-01-01T23:59:59.000Z

    The effect of temperature (T) and angular momentum (J) on the inverse level density parameter (k) has been studied by populating the compound nucleus $^{97}$Tc in the reaction $^{4}$He + $^{93}$Nb at four incident beam energies of 28, 35, 42 and 50 MeV. For all the four energies, the value of k decreases with increasing J. The T dependence of k has been compared for two angular momentum windows with different theoretical predictions as well as with FTBCS1 calculation which takes into account the quasiparticle-number fluctuations in the pairing field. Interestingly, the experimental data are in good agreement with the theoretical calculations at higher J but deviate from all the calculations at lower J.

  7. Applying optical imaging to study neurovascular coupling in cerebral cortex: from populational scale to single-cell single-

    E-Print Network [OSTI]

    Kleinfeld, David

    Applying optical imaging to study neurovascular coupling in cerebral cortex: from populational, University of Texas at Austin, Austin, TX Abstract: We use a suite of optical imaging technologies the hemodynamic response and the underlying brain neuronal activity. © 2006 Optical Society of America OCIS codes

  8. Bone mineral density and fractures in older men with chronic obstructive pulmonary disease or asthma

    E-Print Network [OSTI]

    Dam, T.-T.; Harrison, S.; Fink, H. A.; Ramsdell, J.; Barrett-Connor, E.

    2010-01-01T23:59:59.000Z

    x ORIGINAL ARTICLE Bone mineral density and fractures inwas associated with lower bone mineral density (BMD) at theKeywords Bone loss . Bone mineral density . Elderly .

  9. Energy Aware Self-Organizing Density Management in Wireless Sensor Networks

    E-Print Network [OSTI]

    Merrer, Erwan Le; Kermarrec, Anne-Marie; Viana, Aline; Bertier, Marin

    2008-01-01T23:59:59.000Z

    Energy consumption is the most important factor that determines sensor node lifetime. The optimization of wireless sensor network lifetime targets not only the reduction of energy consumption of a single sensor node but also the extension of the entire network lifetime. We propose a simple and adaptive energy-conserving topology management scheme, called SAND (Self-Organizing Active Node Density). SAND is fully decentralized and relies on a distributed probing approach and on the redundancy resolution of sensors for energy optimizations, while preserving the data forwarding and sensing capabilities of the network. We present the SAND's algorithm, its analysis of convergence, and simulation results. Simulation results show that, though slightly increasing path lengths from sensor to sink nodes, the proposed scheme improves significantly the network lifetime for different neighborhood densities degrees, while preserving both sensing and routing fidelity.

  10. Linking climate change to population cycles of hares and C H U A N Y A N * , N I L S C H R . S T E N S E T H , C H A R L E S J . K R E B S and ZHIBIN ZHANG*

    E-Print Network [OSTI]

    Krebs, Charles J.

    Linking climate change to population cycles of hares and lynx C H U A N Y A N * , N I L S C H R to study the effects of density dependence, predation, and climate (both global climate indices of North, University of British Columbia, Vancouver, B.C., Canada V6T 1Z4 Abstract The classic 10-year population cycle

  11. First Insights into the SWIRE Galaxy Populations

    E-Print Network [OSTI]

    Carol Lonsdale; Maria Polletta; Jason Surace; David Shupe; Fan Fang; C. Kevin Xu; Harding E. Smith; Brian Siana; Michael Rowan-Robinson; Tom Babbedge; Seb Oliver; Francesca Pozzi; Payam Davoodi; Frazer Owen; Deborah Padgett; Dave Frayer; Tom Jarrett; Frank Masci; JoAnne O'Linger; Tim Conrow; Duncan Farrah; Glenn Morrison; Nick Gautier; Alberto Franceschini; Stefano Berta; Ismael Perez-Fournon; Herve Dole; Gordon Stacey; Steve Sergeant; Marguerite Pierre; Matt Griffin; Rick Puetter

    2004-06-08T23:59:59.000Z

    We characterize the SWIRE galaxy populations in the SWIRE validation field within the Lockman Hole, based on the 3.6-24$\\mu$ Spitzer data and deep U,g',r',r' optical imaging within an area ~1/3 sq. deg for ~16,000 Spitzer-SWIRE sources. The entire SWIRE survey will discover over 2.3 million galaxies at 3.6$\\mu$m and almost 350,000 at 24$\\mu$m; ~70,000 of these will be 5-band 3.6-24$\\mu$ detections. The colors cover a broad range, generally well represented by redshifted spectral energy distributions of known galaxy populations, however significant samples of unusually blue objects in the [3.6-4.5]$\\mu$m color are found, as well as many objects very red in the 3.6-24$\\mu$m mid-IR. Nine of these are investigated and are interpreted as star-forming systems, starbursts and AGN from z=0.37 to 2.8, with luminosities from L$_{IR}$=10$^{10.3}$ to 10$^{13.7}$ L$_{\\odot}$

  12. Collisional population transfer in yterbium ions

    SciTech Connect (OSTI)

    Schauer, Martin Michael [Los Alamos National Laboratory; Torgerson, Justin R [Los Alamos National Laboratory; Danielson, Jeremy R [Los Alamos National Laboratory; Zhao, Xinxin [Los Alamos National Laboratory; Nguyen, Ahn - Tuan [UNIV OF PITTSBURGH; Wang, Li - Bang [NATIONAL TSING HUA UNIV

    2009-01-01T23:59:59.000Z

    Long-lived metastable states of Yb+ ions are used for atomic frequency standards, precision measurements, and quantum information research. The effect of population trapping and transfer in these states must be well understood. We report here the transfer of Yb+ ions into the long-lived {sup 2}F{sub 7/2} state by means of collisions between He buffer gas and Yb+ ions held in a linear Paul trap. Transfer rates were measured as functions of buffer-gas pressure and repump-laser power, and the collisional population transfer rates were extracted. The measured transfer rate coefficients are 8.32(75)x10-11 and 8.65(33)x10-11 cm3/s for the collisional processes {sup 2}P{sub 1/2}{yields}{sup 2}D{sub 5/2} and {sup 2}D{sub 3/2}{yields}{sup 2}F{sub 7/2}, respectively.

  13. ORIGINAL PAPER BambooFiber Filled High Density Polyethylene Composites

    E-Print Network [OSTI]

    ORIGINAL PAPER Bamboo­Fiber Filled High Density Polyethylene Composites: Effect of Coupling Springer Science+Business Media, LLC 2008 Abstract High density polyethylene (HDPE)/bamboo composites of the composites were studied. The equilibrium torque during compounding decreased with use of clay master- batch

  14. Kernel Density Based Linear Regression Estimate and Zhibiao Zhao

    E-Print Network [OSTI]

    Zhao, Zhibiao

    Kernel Density Based Linear Regression Estimate Weixin Yao and Zhibiao Zhao Abstract For linear regression models with non-normally distributed errors, the least squares estimate (LSE) will lose some words: EM algorithm, Kernel density estimate, Least squares estimate, Linear regression, Maximum

  15. Distributional Energy-Momentum Densities of Schwarzschild Space-Time

    E-Print Network [OSTI]

    Toshiharu Kawai; Eisaku Sakane

    1997-07-14T23:59:59.000Z

    For Schwarzschild space-time, distributional expressions of energy-momentum densities and of scalar concomitants of the curvature tensors are examined for a class of coordinate systems which includes those of the Schwarzschild and of Kerr-Schild types as special cases. The energy-momentum density $\\tilde T_\\mu^{\

  16. Coded modulation with Low Density Parity Check codes

    E-Print Network [OSTI]

    Narayanaswami, Ravi

    2001-01-01T23:59:59.000Z

    This thesis proposes the design of Low Density Parity Check (LDPC) codes for cases where coded modulation is used. We design these codes by extending the idea of Density Evolution (DE) that has been introduced as a powerful tool to analyze LDPC...

  17. CONCRETE OPTIMISATION WITH REGARD TO PACKING DENSITY AND RHEOLOGY

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    CONCRETE OPTIMISATION WITH REGARD TO PACKING DENSITY AND RHEOLOGY François de Larrard LCPC Centre/organizers): .............. Keywords: packing density, rheology, grading curve, optimisation, self-compacting concrete, roller-compacted concrete. Author contacts Authors E-Mail Fax Postal address LCPC Centre de Nantes François de Larrard

  18. THERMAL CONDUCTIVITY OF HEMP CONCRETES: VARIATION WITH FORMULATION, DENSITY AND

    E-Print Network [OSTI]

    envelope and on the performance of systems. This behaviour is related to hygric and thermal propertiesTHERMAL CONDUCTIVITY OF HEMP CONCRETES: VARIATION WITH FORMULATION, DENSITY AND WATER CONTENT of formulation, density and water content on the thermal conductivity of hemp concretes. The investigations

  19. Evolution of particle density in high-energy pp collisions

    E-Print Network [OSTI]

    I. Bautista; C. Pajares; J. Dias de Deus

    2012-03-09T23:59:59.000Z

    We study the evolution of the particle density, dn/d\\eta at fixed \\eta with the beam rapidity Y in the framework of string percolation model. Our main results are: (i) The width of the "plateau" increases proportionally to Y, (ii) limiting fragmentation is violated, and (iii) the particle density, reduces to a step function.

  20. Low Density Nuclear Matter in Heavy Ion Collisions 

    E-Print Network [OSTI]

    Qin, Lijun

    2010-01-14T23:59:59.000Z

    The symmetry energy is the energy difference between symmetric nuclear matter and pure neutron matter at a given density. Around normal nuclear density, i.e. p/p0 =1, and temperature, i.e. T = 0, the symmetry energy is approximately 23.5 Me...

  1. Simulation of salt migrations in density dependent groundwater flow

    E-Print Network [OSTI]

    Vuik, Kees

    Simulation of salt migrations in density dependent groundwater flow E.S. van Baaren Master's Thesis for the salt migration in the groundwater underneath the polders near the coast. The problem description of this thesis is to investigate the possibilities of modelling salt migrations in density dependent groundwater

  2. Locating a Recycling Center: The General Density Case Jannett Highfill

    E-Print Network [OSTI]

    Mou, Libin

    Locating a Recycling Center: The General Density Case Jannett Highfill Department of Economics) 677-3374. #12;2 Locating a Recycling Center: The General Density Case Abstract: The present paper considers a municipality that has a landfill (fixed in location) and plans to optimally locate a "recycling

  3. Density-Enthalpy Phase Diagram 0D Boiler Simulation

    E-Print Network [OSTI]

    Vuik, Kees

    Diagram 0D Boiler Simulation Finite Element Method Further Research Mass and Heat balances V d dt = i - eDensity-Enthalpy Phase Diagram 0D Boiler Simulation Finite Element Method Further Research Finite Transitions #12;Density-Enthalpy Phase Diagram 0D Boiler Simulation Finite Element Method Further Research

  4. Observation of the density minimum in deeply supercooled confined water

    E-Print Network [OSTI]

    Chen, Sow-Hsin

    of SANS data allows us to determine the absolute value of the density of D2O as a function of temperature remarkable physical properties of liquid water (1), the density maximum is probably the most well known is considered to be the most accurate model for reproducing experimental data when used with a simple spherical

  5. The Planetary Nebula population of the Sagittarius Dwarf Spheroidal Galaxy

    E-Print Network [OSTI]

    Albert Zijlstra; K. Gesicki; J. R. Walsh; D. Pequignot; P. A. M. van Hoof; D. Minniti

    2006-03-16T23:59:59.000Z

    The identification of two new Planetary Nebulae in the Sagittarius Dwarf Spheroidal Galaxy (Sgr) is presented. This brings the total number to four. The first, StWr 2-21, belongs to the main body of Sgr. The second, the halo PN BoBn 1, has a location, distance and velocity in agreement with the leading tidal tail of Sgr. We estimate that 10 per cent of the Galactic halo consists of Sgr debris. The specific frequency of PNe indicates a total luminosity of Sgr, including its tidal tails, of M_V=-14.1. StWr 2-21 shows a high abundance of [O/H]=-0.23, which confirms the high-metallicity population in Sgr uncovered by Bonaficio et al. (2004). The steep metallicity--age gradient in Sgr is due to ISM removal during the Galactic plane passages, ISM reformation due to stellar mass loss, and possibly accretion of metal-enriched gas from our Galaxy. The ISM re-formation rate of Sgr, from stellar mass loss, is 5 X 10^-4 M_sun yr^-1, amounting to ~10^6 M_sun per orbital period. HST images reveal well-developed bipolar morphologies, and provide clear detections of the central stars. All three stars with deep spectra show WR-lines, suggesting that the progenitor mass and metallicity determines whether a PN central star develops a WR spectrum. One Sgr PN belongs to the class of IR-[WC] stars. Expansion velocities are determined for three nebulae. Comparison with hydrodynamical models indicates an initial density profile of rho ~ r^-3. This is evidence for increasing mass-loss rates on the AGB. Peak mass-loss rates are indicated of ~ 10^-4 M_sun yr^-1. The IR-[WC] PN, He 2-436, provides the sole direct detection of dust in a dwarf spheroidal galaxy, to date.

  6. The Dark Bursts population in a complete sample of bright Swift Long Gamma-Ray Bursts

    E-Print Network [OSTI]

    A. Melandri; B. Sbarufatti; P. D'Avanzo; R. Salvaterra; S. Campana; S. Covino; S. D. Vergani; L. Nava; G. Ghisellini; G. Ghirlanda; D. Fugazza; V. Mangano; M. Capalbi; G. Tagliaferri

    2012-02-14T23:59:59.000Z

    We study the properties of the population of optically dark events present in a carefully selected complete sample of bright Swift long gamma-ray bursts. The high level of completeness in redshift of our sample (52 objects out of 58) allow us to establish the existence of a genuine dark population and we are able to estimate the maximum fraction of dark burst events (~30%) expected for the whole class of long gamma-ray burst. The redshift distribution of this population of dark bursts is similar to the one of the whole sample. Interestingly, the rest-frame X-ray luminosity (and the de-absorbed X-ray flux) of the sub-class of dark bursts is slightly higher than the average luminosity of the non-dark events. At the same time the prompt properties do not differ and the optical flux of dark events is at the lower tail of the optical flux distribution, corrected for Galactic absorption. All these properties suggest that dark bursts events generate in much denser environments with respect to normal bright events. We can therefore exclude the high-z and the low-density scenarios and conclude that the major cause of the origin of optically dark events is the dust extinction.

  7. Impact of impingement on the Hudson River white perch population. Final report

    SciTech Connect (OSTI)

    Barnthouse, L.W.; Van Winkle, W.; Kirk, B.L.; Vaughan, D.S.

    1982-02-01T23:59:59.000Z

    This report summarizes a series of analyses of the magnitude and biological significance of the impingement of white perch at the Indian Point Nuclear Generating Station and other Hudson River power plants. Included in these analyses were evaluations of: (1) two independent lines of evidence relating to the magnitude of impingement impacts on the Hudson River white perch population; (2) the additional impact caused by entrainment of white perch; (3) data relating to density-dependent growth among young-of-the-year white perch; (4) the feasibility of performing population-level analyses of impingement impacts on the white perch populations of Chesapeake Bay and the Delaware River; and (5) the feasibility of using simple food chain and food web models to evaluate community-level effects of impingement and entrainment. Estimated reductions in the abundances of the 1974 and 1975 white perch year classes, caused by impingement and entrainment, were high enough that the possibility of adverse long-term effects cannot be excluded.

  8. Breeding bird populations and habitat associations within the Savannah River Site (SRS).

    SciTech Connect (OSTI)

    Gauthreaux, Sidney, A.; Steven J. Wagner.

    2005-06-29T23:59:59.000Z

    Gauthreaux, Sidney, A., and Steven J. Wagner. 2005. Breeding bird populations and habitat associations within the Savannah River Site (SRS). Final Report. USDA Forest Service, Savannah River, Aiken, SC. 48 pp. Abstract: During the 1970's and 1980's a dramatic decline occurred in the populations of Neotropical migratory birds, species that breed in North America and winter south of the border in Central and South America and in the Caribbean. In 1991 an international initiative was mounted by U. S. governmental land management agencies, nongovernmental conservation agencies, and the academic and lay ornithological communities to understand the decline of Neotropical migratory birds in the Americas. In cooperation with the USDA Forest Service - Savannah River (FS - SR) we began 1992 a project directed to monitoring population densities of breeding birds using the Breeding Bird Census (BBC) methodology in selected habitats within the Savannah River Site SRS. In addition we related point count data on the occurrence of breeding Neotropical migrants and other bird species to the habitat data gathered by the Forest Inventory and Analysis (FIA) program of the USDA Forest Service and data on habitat treatments within forest stands.

  9. Density Power Spectrum of Compressible Hydrodynamic Turbulent Flows

    E-Print Network [OSTI]

    Jongsoo Kim; Dongsu Ryu

    2005-07-26T23:59:59.000Z

    Turbulent flows are ubiquitous in astrophysical environments, and understanding density structures and their statistics in turbulent media is of great importance in astrophysics. In this paper, we study the density power spectra, $P_{\\rho}$, of transonic and supersonic turbulent flows through one and three-dimensional simulations of driven, isothermal hydrodynamic turbulence with root-mean-square Mach number in the range of $1 \\la M_{\\rm rms} \\la 10$. From one-dimensional experiments we find that the slope of the density power spectra becomes gradually shallower as the rms Mach number increases. It is because the density distribution transforms from the profile with {\\it discontinuities} having $P_{\\rho} \\propto k^{-2}$ for $M_{\\rm rms} \\sim 1$ to the profile with {\\it peaks} having $P_{\\rho} \\propto k^0$ for $M_{\\rm rms} \\gg 1$. We also find that the same trend is carried to three-dimension; that is, the density power spectrum flattens as the Mach number increases. But the density power spectrum of the flow with $M_{\\rm rms} \\sim 1$ has the Kolmogorov slope. The flattening is the consequence of the dominant density structures of {\\it filaments} and {\\it sheets}. Observations have claimed different slopes of density power spectra for electron density and cold H I gas in the interstellar medium. We argue that while the Kolmogorov spectrum for electron density reflects the {\\it transonic} turbulence of $M_{\\rm rms} \\sim 1$ in the warm ionized medium, the shallower spectrum of cold H I gas reflects the {\\it supersonic} turbulence of $M_{\\rm rms} \\sim$ a few in the cold neutral medium.

  10. A NEW POPULATION OF HIGH-z, DUSTY Ly{alpha} EMITTERS AND BLOBS DISCOVERED BY WISE: FEEDBACK CAUGHT IN THE ACT?

    SciTech Connect (OSTI)

    Bridge, Carrie R. [California Institute of Technology, MS249-17, Pasadena, CA 91125 (United States); Blain, Andrew [Department of Physics and Astronomy, University of Leicester, LE1 7RH Leicester (United Kingdom); Borys, Colin J. K.; Griffith, Roger L.; Tsai, Chao-Wei [Infrared Processing and Analysis Center, California Institute of Technology, MS 100-22, Pasadena, CA 91125 (United States); Petty, Sara; Farrah, Duncan [Department of Physics, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Benford, Dominic [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Eisenhardt, Peter; Stern, Daniel; Wu Jingwen [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109 (United States); Jarrett, Tom [Astronomy Department, University of Cape Town, Rondebosch 7701 (South Africa); Lonsdale, Carol [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Stanford, Spencer A. [Department of Physics, University of California Davis, One Shields Ave., Davis, CA 95616 (United States); Wright, Edward L., E-mail: bridge@astro.caltech.edu [Astronomy Department, University of California Los Angeles, Los Angeles, CA 90095 (United States)

    2013-06-01T23:59:59.000Z

    By combining data from the NASA Wide-field Infrared Survey Explorer (WISE) mission with optical spectroscopy from the W. M. Keck telescope, we discover a mid-IR color criterion that yields a 78% success rate in identifying rare, typically radio-quiet, 1.6 {approx}< z {approx}< 4.6 dusty Ly{alpha} emitters (LAEs). Of these, at least 37% have emission extended on scales of 30-100 kpc and are considered Ly{alpha} ''blobs'' (LABs). The objects have a surface density of only {approx}0.1 deg{sup -2}, making them rare enough that they have been largely missed in deep, small area surveys. We measured spectroscopic redshifts for 92 of these galaxies, and find that the LAEs (LABs) have a median redshift of 2.3 (2.5). The WISE photometry coupled with data from Herschel (Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA) reveals that these galaxies are in the Hyper Luminous IR galaxy regime (L{sub IR} {approx}> 10{sup 13}-10{sup 14} L{sub Sun }) and have warm colors. They are typically more luminous and warmer than other dusty, z {approx} 2 populations such as submillimeter-selected galaxies and dust-obscured galaxies. These traits are commonly associated with the dust being illuminated by intense active galactic nucleus activity. We hypothesize that the combination of spatially extended Ly{alpha}, large amounts of warm IR-luminous dust, and rarity (implying a short-lived phase) can be explained if the galaxies are undergoing brief, intense ''feedback'' transforming them from an extreme dusty starburst/QSO into a mature galaxy.

  11. Journal of Theoretical Biology 227 (2004) 397401 Evolutionary stability for large populations

    E-Print Network [OSTI]

    Gordon, Geoffrey J.

    population ESS, as distinct from Maynard Smith's infinite population ESS and Schaffer's finite population ESS. Building on Schaffer's finite population model, we define the large population ESS as a strategy which. The large population ESS is not equivalent to the infinite population ESS: we give examples of games

  12. Examining the specific entropy (density of adiabatic invariants) of the outer electron radiation belt

    SciTech Connect (OSTI)

    Borovsky, Joseph E [Los Alamos National Laboratory; Denton, Michael H [LANCASTER UNIV

    2008-01-01T23:59:59.000Z

    Using temperature and number-density measurements of the energetic-electron population from multiple spacecraft in geosynchronous orbit, the specific entropy S = T/n{sup 2/3} of the outer electron radiation belt is calculated. Then 955,527 half-hour-long data intervals are statistically analyzed. Local-time and solar-cycle variations in S are examined. The median value of the specific entropy (2.8 x 10{sup 7} eVcm{sup 2}) is much larger than the specific entropy of other particle populations in and around the magnetosphere. The evolution of the specific entropy through high-speed-stream-driven geomagnetic storms and through magnetic-cloud-driven geomagnetic storms is studied using superposed-epoch analysis. For high-speed-stream-driven storms, systematic variations in the entropy associated with electron loss and gain and with radiation-belt heating are observed in the various storm phases. For magnetic-cloud-driven storms, multiple trigger choices for the data superpositions reveal the effects of interplanetary shock arrival, sheath driving, cloud driving, and recovery phase. The specific entropy S = T/n{sup 2/3} is algebraically expressed in terms of the first and second adiabatic invariants of the electrons: this allows a relativistic expression for S in terms of T and n to be derived. For the outer electron radiation belt at geosynchronous orbit, the relativistic corrections to the specific entropy expression are -15%.

  13. Measuring and Modeling Fault Density for Plume-Fault Encounter Probability Estimation

    SciTech Connect (OSTI)

    Jordan, P.D.; Oldenburg, C.M.; Nicot, J.-P.

    2011-05-15T23:59:59.000Z

    Emission of carbon dioxide from fossil-fueled power generation stations contributes to global climate change. Storage of this carbon dioxide within the pores of geologic strata (geologic carbon storage) is one approach to mitigating the climate change that would otherwise occur. The large storage volume needed for this mitigation requires injection into brine-filled pore space in reservoir strata overlain by cap rocks. One of the main concerns of storage in such rocks is leakage via faults. In the early stages of site selection, site-specific fault coverages are often not available. This necessitates a method for using available fault data to develop an estimate of the likelihood of injected carbon dioxide encountering and migrating up a fault, primarily due to buoyancy. Fault population statistics provide one of the main inputs to calculate the encounter probability. Previous fault population statistics work is shown to be applicable to areal fault density statistics. This result is applied to a case study in the southern portion of the San Joaquin Basin with the result that the probability of a carbon dioxide plume from a previously planned injection had a 3% chance of encountering a fully seal offsetting fault.

  14. Engineering the initial state in broadband population inversion

    E-Print Network [OSTI]

    Bo Y. Chang; Sheokmin Shin; Ignacio R. Sola

    2015-03-03T23:59:59.000Z

    Quantum systems with sublevel structures prevent full population inversion from one manifold of sublevels to the other using strong ultrafast resonant pulses. In this work we explain the mechanism by which this population transfer is blocked. We then develop a novel concept of geometric control, assuming full or partial coherent manipulation within the manifolds and show that by preparing specific coherent superpositions in the initial manifold, full population inversion or full population blockade, {\\it i.e} laser-induced transparency, can be achieved. In particular, by parallel population transfer we show how population inversion between the manifolds can be obtained with minimal pulse area. As the number of sublevels increases, population inversion can overcome the pulse area theorem at the expense of full control over the initial manifold of sublevels.

  15. Population and Climate Change:Population and Climate Change: Are they related?Are they related?

    E-Print Network [OSTI]

    Kalnay, Eugenia

    depletion: water, oil, fisheries, topsoil, etc. · Resource wars and civil conflicts · Malnutrition and world! We are still missing the most important component of the Earth System: the Human System #12;Is, population would be much smaller! · Growth in grain production is now flattening out · Industrial farming

  16. The Birth of a Galaxy: Primoridal Metal Enrichment and Population II Stellar Populations

    E-Print Network [OSTI]

    Wise, John H; Norman, Michael L; Abel, Tom

    2010-01-01T23:59:59.000Z

    Population III stars first form in dark matter halos with masses around 10^6 Msun. By definition, they are metal-free, and their protostellar collapse is driven by molecular hydrogen cooling in the gas-phase, leading to a massive characteristic mass ~100 Msun and suppressed fragmentation. Population II stars with lower characteristic masses form when the star-forming gas reaches a critical metallicity of 10^{-6} - 10^{-3.5} Zsun, depending on whether dust cooling is important. We present adaptive mesh refinement radiation hydrodynamics simulations that follows the transition from Population III to II star formation. We model stellar radiative feedback with adaptive ray tracing. A top-heavy initial mass function for the Population III stars is considered, resulting in a plausible distribution of pair-instability supernovae and associated metal enrichment. We find that the gas fraction recovers from 5 percent to nearly the cosmic fraction in halos with merger histories rich in halos above 10^7 Msun. A single pa...

  17. Running heading: Bulk density of a clayey subsoil Increase in the bulk density of a Grey Clay subsoil by

    E-Print Network [OSTI]

    Boyer, Edmond

    1 Running heading: Bulk density of a clayey subsoil Increase in the bulk density of a Grey Clay of the prisms were coated by material similar in composition to the topsoil and separated from as the profile dries over summer leading to widening of cracks between prismatic peds, (2) infilling of cracks

  18. Density Measurement Worksheet. Use this sheet to determine if your formula is consistent with the known densities of

    E-Print Network [OSTI]

    Meagher, Mary

    Density Measurement Worksheet. Use this sheet to determine if your formula is consistent with the known densities of various compounds. Formula : Formula weight : _______________ (FW) Unit Cell Volume :______________ (V) Probable Z value for your Laue symmetry (based on the unit cell: table 1) : ______ (Z) Formula V

  19. A model for cerebral cortical neuron group electric activity and its implications for cerebral function

    E-Print Network [OSTI]

    Karameh, Fadi Nabih

    2002-01-01T23:59:59.000Z

    The electroencephalogram, or EEG, is a recording of the field potential generated by the electric activity of neuronal populations of the brain. Its utility has long been recognized as a monitor which reflects the vigilance ...

  20. Old stellar populations in distant radio galaxies

    E-Print Network [OSTI]

    James Dunlop

    1998-01-13T23:59:59.000Z

    I describe the current status of our attempts to determine the age of the oldest known stellar populations at high redshift, in the red mJy radio galaxies 53W091 ($z = 1.55$) and 53W069 ($z = 1.43$). During the past year the original conclusion of Dunlop et al. (1996) - that 53W091 is $>3$ Gyr old - has been questioned from two, basically orthogonal directions. First, reports that the near-infrared light from 53W091 is highly polarized have cast some doubt on whether its red colour is genuinely due to an old population of stars. Second, assuming that all the light is indeed due to stars, it has been claimed that 53W091 is in fact only 1-2 Gyr old. Here I present a preliminary analysis of new infrared polarimetric observations of 53W091 which show that the first of these criticisms can be rejected with very high confidence. I then explore why different modellers have derived different ages for 53W091, and present new model fits to the spectrum of 53W069 which demonstrate that different spectral synthesis codes are certainly in good agreement that this galaxy is 3-4 Gyr old. Finally I present a preliminary analysis of the morphologies and scale-lengths of 53W091 and 53W069 as derived from new I-band WFPC2 HST images, and compare the results with those for 3CR galaxies at comparable redshifts. I conclude that the scalelengths and luminosities of radio galaxies at $z \\simeq 1.5$ appear to scale together as would be predicted from the Kormendy relation for low-redshift elliptical galaxies.

  1. Experiments to populate and validate a processing model for polyurethane foam :

    SciTech Connect (OSTI)

    Mondy, Lisa Ann; Rao, Rekha Ranjana; Shelden, Bion; Soehnel, Melissa Marie; O'Hern, Timothy J.; Grillet, Anne; Celina, Mathias Christopher; Wyatt, Nicholas B.; Russick, Edward Mark; Bauer, Stephen J.; Hileman, Michael Bryan; Urquhart, Alexander; Thompson, Kyle Richard; Smith, David Michael

    2014-03-01T23:59:59.000Z

    We are developing computational models to elucidate the expansion and dynamic filling process of a polyurethane foam, PMDI. The polyurethane of interest is chemically blown, where carbon dioxide is produced via the reaction of water, the blowing agent, and isocyanate. The isocyanate also reacts with polyol in a competing reaction, which produces the polymer. Here we detail the experiments needed to populate a processing model and provide parameters for the model based on these experiments. The model entails solving the conservation equations, including the equations of motion, an energy balance, and two rate equations for the polymerization and foaming reactions, following a simplified mathematical formalism that decouples these two reactions. Parameters for the polymerization kinetics model are reported based on infrared spectrophotometry. Parameters describing the gas generating reaction are reported based on measurements of volume, temperature and pressure evolution with time. A foam rheology model is proposed and parameters determined through steady-shear and oscillatory tests. Heat of reaction and heat capacity are determined through differential scanning calorimetry. Thermal conductivity of the foam as a function of density is measured using a transient method based on the theory of the transient plane source technique. Finally, density variations of the resulting solid foam in several simple geometries are directly measured by sectioning and sampling mass, as well as through x-ray computed tomography. These density measurements will be useful for model validation once the complete model is implemented in an engineering code.

  2. Symmetry energy at subnuclear densities deduced from nuclear masses

    E-Print Network [OSTI]

    Kazuhiro Oyamatsu; Kei Iida

    2010-04-19T23:59:59.000Z

    We examine how nuclear masses are related to the density dependence of the symmetry energy. Using a macroscopic nuclear model we calculate nuclear masses in a way dependent on the equation of state of asymmetric nuclear matter. We find by comparison with empirical two-proton separation energies that a smaller symmetry energy at subnuclear densities, corresponding to a larger density symmetry coefficient L, is favored. This tendency, which is clearly seen for nuclei that are neutron-rich, nondeformed, and light, can be understood from the property of the surface symmetry energy in a compressible liquid-drop picture.

  3. Nuclear Energy Density Functionals Constrained by Low-Energy QCD

    E-Print Network [OSTI]

    Dario Vretenar

    2008-02-06T23:59:59.000Z

    A microscopic framework of nuclear energy density functionals is reviewed, which establishes a direct relation between low-energy QCD and nuclear structure, synthesizing effective field theory methods and principles of density functional theory. Guided by two closely related features of QCD in the low-energy limit: a) in-medium changes of vacuum condensates, and b) spontaneous breaking of chiral symmetry; a relativistic energy density functional is developed and applied in studies of ground-state properties of spherical and deformed nuclei.

  4. Precision Cosmology and the Density of Baryons in the Universe

    E-Print Network [OSTI]

    M. Kaplinghat; M. S. Turner

    2000-11-14T23:59:59.000Z

    Big-bang Nucleosynthesis (BBN) and Cosmic Microwave Background (CMB) anisotropy measurements give independent, accurate measurements of the baryon density and can test the framework of the standard cosmology. Early CMB data are consistent with the longstanding conclusion from BBN that baryons constitute a small fraction of matter in the Universe, but may indicate a slightly higher value for the baryon density. We clarify precisely what the two methods determine, and point out that differing values for the baryon density can indicate either an inconsistency or physics beyond the standard models of cosmology and particle physics. We discuss other signatures of the new physics in CMB anisotropy.

  5. Constraining the nuclear symmetry-energy at super-density

    E-Print Network [OSTI]

    Yong, Gao-Chan

    2015-01-01T23:59:59.000Z

    The nuclear symmetry-energy has broad implications in both nuclear physics and astrophysics. Due to hard work of many people, the nuclear symmetry-energy around saturation density has been roughly constrained. However, the nuclear symmetry-energy at super-density is still in chaos. By considering both the effects of the nucleon-nucleon short-rang correlations and the isospin-dependent in-medium inelastic baryon-baryon scattering cross sections in the transport model, two unrelated experimental measurements are simultaneously analyzed. A soft symmetry-energy at super-density is first consistently obtained by the double comparison of the symmetry-energy sensitive observables.

  6. Measurements of electron density profiles using an angular filter refractometer

    SciTech Connect (OSTI)

    Haberberger, D., E-mail: dhab@lle.rochester.edu; Ivancic, S.; Hu, S. X.; Boni, R.; Barczys, M.; Craxton, R. S.; Froula, D. H. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14636 (United States)] [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14636 (United States)

    2014-05-15T23:59:59.000Z

    A novel diagnostic technique, angular filter refractometry (AFR), has been developed to characterize high-density, long-scale-length plasmas relevant to high-energy-density physics experiments. AFR measures plasma densities up to 10{sup 21}?cm{sup ?3} with a 263-nm probe laser and is used to study the plasma expansion from CH foil and spherical targets that are irradiated with ?9?kJ of ultraviolet (351-nm) laser energy in a 2-ns pulse. The data elucidate the temporal evolution of the plasma profile for the CH planar targets and the dependence of the plasma profile on target radius for CH spheres.

  7. B-Cell Activation and Non-Hodgkin Lymphoma Risk in an HIV Positive Population

    E-Print Network [OSTI]

    Chang, Po-Yin

    2013-01-01T23:59:59.000Z

    IL-27, IL-31, LIF), IP-10 and SDF-1? were measured using the8 (CXCL8) IP-10 (CXCL10) SDF-1? (CXCL12) Putative Functions10 IFN?-induced protein 10; SDF stromal cell-derived factor;

  8. E-Print Network 3.0 - active elderly population--can Sample Search...

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

    Biology and Medicine ; Computer Technologies and Information Sciences 3 Hospice Care: Caring for Elders with Termi nal Illnesses and Their Families Summary: Hospice Care:...

  9. Mortality benefits of population-wide adherence to national physical activity guidelines: a prospective cohort study

    E-Print Network [OSTI]

    Long, Gráinne; Watkinson, Clare; Brage, Søren; Morris, Jerry; Tuxworth, Bill; Fentem, Peter; Griffin, Simon; Simmons, Rebecca; Wareham, Nicholas

    2014-11-07T23:59:59.000Z

    , and Ursula Harries. With thanks to Stephen Sharp (MRC Epidemiology Unit) for statistical help. The Allied Dunbar National Fitness Survey was funded by the Department of Health, Health Education Authority, The Sports Council and Allied Dunbar Assurance plc...

  10. Wintering activity range and population ecology of Black-faced spoonbills (Platalea minor) in Taiwan

    E-Print Network [OSTI]

    Liu, Liang-Li

    2007-09-17T23:59:59.000Z

    research about habitat use by BFS on wintering sites. Lee et al. (1995) reported sites at Chi-Ku town were used by spoonbills for 50 years. They found spoonbills mainly used the tidal mudflat, shallow water, lagoons, and fish ponds. Wang and Chen...

  11. Impact of entrainment and impingement on fish populations in the Hudson River estuary. Volume I. Entrainment-impact estimates for six fish populations inhabiting the Hudson River estuary

    SciTech Connect (OSTI)

    Boreman, J.; Barnthouse, L.W.; Vaughn, D.S.; Goodyear, C.P.; Christensen, S.W.; Kumar, K.D.; Kirk, B.L.; Van Winkle, W.

    1982-01-01T23:59:59.000Z

    This volume is concerned with the estimation of the direct (or annual) entrainment impact of power plants on populations of striped bass, white perch, Alosa spp. (blueback herring and alewife), American shad, Atlantic tomcod, and bay anchovy in the Hudson River estuary. Entrainment impact results from the killing of fish eggs, larvae, and young juveniles that are contained in the cooling water cycled through a power plant. An Empirical Transport Model (ETM) is presented as the means of estimating a conditional entrainment mortality rate (defined as the fraction of a year class which would be killed due to entrainment in the absence of any other source of mortality). Most of this volume is concerned with the estimation of several parameters required by the ETM: physical input parameters (e.g., power-plant withdrawal flow rates); the longitudinal distribution of ichthyoplankton in time and space; the duration of susceptibility of the vulnerable organisms; the W-factors, which express the ratios of densities of organisms in power plant intakes to densities of organisms in the river; and the entrainment mortality factors (f-factors), which express the probability that an organism will be killed if it is entrained. Once these values are obtained, the ETM is used to estimate entrainment impact for both historical and projected conditions.

  12. Evaluation of macromolecular electron-density map quality using the correlation of local r.m.s. density

    SciTech Connect (OSTI)

    Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Structural Biology Group, Mail Stop M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Berendzen, Joel [Biophysics Group, Mail Stop D454, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Structural Biology Group, Mail Stop M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    1999-11-01T23:59:59.000Z

    The correlation of local r.m.s. density is shown to be a good measure of the presence of distinct solvent and macromolecule regions in macromolecular electron-density maps. It has recently been shown that the standard deviation of local r.m.s. electron density is a good indicator of the presence of distinct regions of solvent and protein in macromolecular electron-density maps [Terwilliger & Berendzen (1999 ?). Acta Cryst. D55, 501–505]. Here, it is demonstrated that a complementary measure, the correlation of local r.m.s. density in adjacent regions on the unit cell, is also a good measure of the presence of distinct solvent and protein regions. The correlation of local r.m.s. density is essentially a measure of how contiguous the solvent (and protein) regions are in the electron-density map. This statistic can be calculated in real space or in reciprocal space and has potential uses in evaluation of heavy-atom solutions in the MIR and MAD methods as well as for evaluation of trial phase sets in ab initio phasing procedures.

  13. High energy-density water: density functional theory calculations of structure and electrical conductivity.

    SciTech Connect (OSTI)

    Desjarlais, Michael Paul; Mattsson, Thomas Kjell Rene

    2006-03-01T23:59:59.000Z

    Knowledge of the properties of water is essential for correctly describing the physics of shock waves in water as well as the behavior of giant planets. By using finite temperature density functional theory (DFT), we have investigated the structure and electronic conductivity of water across three phase transitions (molecular liquid/ ionic liquid/super-ionic/electronic liquid). There is a rapid transition to ionic conduction at 2000 K and 2 g/cm{sup 3} while electronic conduction dominates at temperatures above 6000 K. We predict that the fluid bordering the super-ionic phase is conducting above 4000 K and 100 GPa. Earlier work instead has the super-ionic phase bordering an insulating fluid, with a transition to metallic fluid not until 7000 K and 250 GPa. The tools and expertise developed during the project can be applied to other molecular systems, for example, methane, ammonia, and CH foam. We are now well positioned to treat also complex molecular systems in the HEDP regime of phase-space.

  14. Electron density measurements of atmospheric-pressure non-thermal N{sub 2} plasma jet by Stark broadening and irradiance intensity methods

    SciTech Connect (OSTI)

    Xiao, Dezhi; Shen, Jie; Lan, Yan; Xie, Hongbing; Shu, Xingsheng; Meng, Yuedong; Li, Jiangang [Institute of Plasma Physics, Chinese Academy of Sciences, P. O. Box 1126, Hefei 230031 (China); Cheng, Cheng, E-mail: chengcheng@ipp.ac.cn, E-mail: paul.chu@cityu.edu.hk [Institute of Plasma Physics, Chinese Academy of Sciences, P. O. Box 1126, Hefei 230031 (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Chu, Paul K., E-mail: chengcheng@ipp.ac.cn, E-mail: paul.chu@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

    2014-05-15T23:59:59.000Z

    An atmospheric-pressure non-thermal plasma jet excited by high frequency alternating current using nitrogen is developed and the electron density in the active region of this plasma jet is investigated by two different methods using optical emission spectroscopy, Stark broadening, and irradiance intensity method. The irradiance intensity method shows that the average electron density is about 10{sup 20}/m{sup 3} which is slightly smaller than that by the Stark broadening method. However, the trend of the change in the electron density with input power obtained by these two methods is consistent.

  15. Secondary Energy Infobook Activities (19 Activities)'

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

    Infobook Activities (19 Activities) Grades: 9-12 Topics: Energy Basics Owner: NEED This educational material is brought to you by the U.S. Department of Energy's Office of Energy...

  16. Activated Boron Nitride Derived from Activated Carbon

    E-Print Network [OSTI]

    Zettl, Alex

    combination of chemical, thermal, and electrical properties. The utility of activated carbon suggests is characterized by scanning electron microscopy, high-resolution transmission electron microscopy, electron energy loss spectroscopy, and surface area analysis. The activated BN microstructure is similar

  17. Measurements of neutral helium density in helicon plasmas

    SciTech Connect (OSTI)

    Houshmandyar, Saeid; Sears, Stephanie H.; Thakur, Saikat Chakraborty; Carr, Jerry Jr.; Galante, Matthew E.; Scime, Earl E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States)

    2010-10-15T23:59:59.000Z

    Laser-induced-fluorescence (LIF) is used to measure the density of helium atoms in a helicon plasma source. For a pump wavelength of 587.725 nm (vacuum) and laser injection along the magnetic field, the LIF signal exhibits a signal decrease at the Doppler shifted central wavelength. The drop in signal results from the finite optical depth of the plasma and the magnitude of the decrease is proportional to the density of excited state neutral atoms. Using Langmuir probe measurements of plasma density and electron temperature and a collisional-radiative model, the absolute ground state neutral density is calculated from the optical depth measurements. Optimal plasma performance, i.e., the largest neutral depletion on the axis of the system, is observed for antenna frequencies of 13.0 and 13.5 MHz and magnetic field strengths of 550-600 G.

  18. Surface modification of low density silica and bridged polysilsesquioxane aerogels

    SciTech Connect (OSTI)

    DeFriend, K. A. (Kimberly A.); Loy, D. A. (Douglas A.); Salazar, K. V. (Kenneth V.); Wilson, K. V. (Kennard V.)

    2004-01-01T23:59:59.000Z

    Silica and bridged polysilsesquioxane aerogels are low density materials that are attractive for applications such as, thermal insulation, porous separation media or catalyst supports, adsorbents. However, aerogels are notoriously weak and brittle making it difficult to handle and machine monoliths into desired forms. This prevents the development of many applications that would otherwise benefit from the use of the low density materials. We will describe our efforts to chemically modify and mechanically enhance silica-based aerogels using chemical vapor techniques without sacrificing their characteristic low densities. Monolithic silica and organically bridged polysilsesquioxane aerogels were prepared by sol-gel polymerization of the respective methoxysilane monomers followed by supercritical carbon dioxide drying of the gels. Reactive modification of the gels with volatile silylating compounds during and after the drying process and these effects on the mechanical properties and density of the aerogels will be described.

  19. Diffusion driven object propulsion in density stratified fluids

    E-Print Network [OSTI]

    Lenahan, Conor (Conor P.)

    2009-01-01T23:59:59.000Z

    An experimental study was conducted in order to verify the appropriateness of a two dimensional model of the flow creating diffusion driven object propulsion in density stratified fluids. Initial flow field experiments ...

  20. Direct Experimental Determination of Spectral Densities of Molecular Complexes

    E-Print Network [OSTI]

    Leonardo A. Pachon; Paul Brumer

    2014-10-15T23:59:59.000Z

    Determining the spectral density of a molecular system immersed in a proteomic scaffold and in contact to a solvent is a fundamental challenge in the coarse-grained description of, e.g., electron and energy transfer dynamics. Once the spectral density is characterized, all the time scales are captured and no artificial separation between fast and slow processes need be invoked. Based on the fluorescence Stokes shift function, we utilize a simple and robust strategy to extract the spectral density of a number of molecular complexes from available experimental data. Specifically, we show that experimental data for dye molecules in several solvents, amino acid proteins in water, and some photochemical systems (e.g., rhodopsin and green fluorescence proteins), are well described by a three-parameter family of sub-Ohmic spectral densities that are characterized by a fast initial Gaussian-like decay followed by a slow algebraic-like decay rate at long times.

  1. Direct experimental determination of spectral densities of molecular complexes

    SciTech Connect (OSTI)

    Pachón, Leonardo A. [Grupo de Física Atómica y Molecular, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Chemical Physics Theory Group, Department of Chemistry and Center for Quantum Information and Quantum Control, University of Toronto, Toronto, Ontario M5S 3H6 (Canada); Brumer, Paul [Chemical Physics Theory Group, Department of Chemistry and Center for Quantum Information and Quantum Control, University of Toronto, Toronto, Ontario M5S 3H6 (Canada)

    2014-11-07T23:59:59.000Z

    Determining the spectral density of a molecular system immersed in a proteomic scaffold and in contact to a solvent is a fundamental challenge in the coarse-grained description of, e.g., electron and energy transfer dynamics. Once the spectral density is characterized, all the time scales are captured and no artificial separation between fast and slow processes need to be invoked. Based on the fluorescence Stokes shift function, we utilize a simple and robust strategy to extract the spectral density of a number of molecular complexes from available experimental data. Specifically, we show that experimental data for dye molecules in several solvents, amino acid proteins in water, and some photochemical systems (e.g., rhodopsin and green fluorescence proteins), are well described by a three-parameter family of sub-Ohmic spectral densities that are characterized by a fast initial Gaussian-like decay followed by a slow algebraic-like decay rate at long times.

  2. areal density measurement: Topics by E-print Network

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

    University of Rochester, Rochester, New York 14623 Received 14 light. The high-energy protons from these implosions were used to infer fuel areal density (6.8 0.5 mg . In...

  3. atheroprotective high-density lipoprotein: Topics by E-print...

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

    the mean-field energy functional. By studying the latter we derive global properties of high-density ground state configurations in bounded domains and in infinite space. Our main...

  4. Low density lipoprotein fraction assay for cardiac disease risk

    DOE Patents [OSTI]

    Krauss, Ronald M. (Berkeley, CA); Blanche, Patricia J. (Berkeley, CA); Orr, Joseph (San Pablo, CA)

    1999-01-01T23:59:59.000Z

    A variable rate density gradient electrophoric gel is described which separate LDL subfractions with the precision of ultracentrifugation techniques. Also, an innovative bottom inlet mixing chamber particularly useful for producing these gels is described.

  5. Nuclear Energy Density Functionals: What do we really know?

    E-Print Network [OSTI]

    Bulgac, Aurel; Jin, Shi

    2015-01-01T23:59:59.000Z

    We present the simplest nuclear energy density functional (NEDF) to date, determined by only 4 significant phenomenological parameters, yet capable of fitting measured nuclear masses with better accuracy than the Bethe-Weizs\\"acker mass formula, while also describing density structures (charge radii, neutron skins etc.) and time-dependent phenomena (induced fission, giant resonances, low energy nuclear collisions, etc.). The 4 significant parameters are necessary to describe bulk nuclear properties (binding energies and charge radii); an additional 2 to 3 parameters have little influence on the bulk nuclear properties, but allow independent control of the density dependence of the symmetry energy and isovector excitations, in particular the Thomas-Reiche-Kuhn sum rule. This Hohenberg-Kohn-style of density functional theory successfully realizes Weizs\\"acker's ideas and provides a computationally tractable model for a variety of static nuclear properties and dynamics, from finite nuclei to neutron stars, where...

  6. Recovering Risk-Neutral Probability Density Functions from Options ...

    E-Print Network [OSTI]

    density function (pdf) of the future prices of an underlying asset from the prices of ...... options prices: An application to crude oil during theI² ulfcw risis. © o£ rd¨.

  7. Magnetic Fields in High-Density Stellar Matter

    E-Print Network [OSTI]

    German Lugones

    2005-04-20T23:59:59.000Z

    I briefly review some aspects of the effect of magnetic fields in the high density regime relevant to neutron stars, focusing mainly on compact star structure and composition, superconductivity, combustion processes, and gamma ray bursts.

  8. Kernel density estimation of a multidimensional efficiency profile

    E-Print Network [OSTI]

    Anton Poluektov

    2014-11-20T23:59:59.000Z

    Kernel density estimation is a convenient way to estimate the probability density of a distribution given the sample of data points. However, it has certain drawbacks: proper description of the density using narrow kernels needs large data samples, whereas if the kernel width is large, boundaries and narrow structures tend to be smeared. Here, an approach to correct for such effects, is proposed that uses an approximate density to describe narrow structures and boundaries. The approach is shown to be well suited for the description of the efficiency shape over a multidimensional phase space in a typical particle physics analysis. An example is given for the five-dimensional phase space of the $\\Lambda_b^0\\to D^0p\\pi$ decay.

  9. Negative vacuum energy densities and the causal diamond measure

    SciTech Connect (OSTI)

    Salem, Michael P. [Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, Massachusetts 02155 (United States)

    2009-07-15T23:59:59.000Z

    Arguably a major success of the landscape picture is the prediction of a small, nonzero vacuum energy density. The details of this prediction depend in part on how the diverging spacetime volume of the multiverse is regulated, a question that remains unresolved. One proposal, the causal diamond measure, has demonstrated many phenomenological successes, including predicting a distribution of positive vacuum energy densities in good agreement with observation. In the string landscape, however, the vacuum energy density is expected to take positive and negative values. We find the causal diamond measure gives a poor fit to observation in such a landscape - in particular, 99.6% of observers in galaxies seemingly just like ours measure a vacuum energy density smaller than we do, most of them measuring it to be negative.

  10. Observation of the Density Minimum in Deeply Supercooled Confined Water

    E-Print Network [OSTI]

    Dazhi Liu; Yang Zhang; Chia-Cheng Chen; Chung-Yuan Mou; Peter H Poole; Sow-Hsin Chen

    2007-04-17T23:59:59.000Z

    Small angle neutron scattering (SANS) is used to measure the density of heavy water contained in 1-D cylindrical pores of mesoporous silica material MCM-41-S-15, with pores of diameter of 15+-1 A. In these pores the homogenous nucleation process of bulk water at 235 K does not occur and the liquid can be supercooled down to at least 160 K. The analysis of SANS data allows us to determine the absolute value of the density of D2O as a function of temperature. We observe a density minimum at 210+-5 K with a value of 1.041+-0.003 g/cm3. We show that the results are consistent with the predictions of molecular dynamics simulations of supercooled bulk water. This is the first experimental report of the existence of the density minimum in supercooled water.

  11. Paper area density measurement from forward transmitted scattered light

    DOE Patents [OSTI]

    Koo, Jackson C. (San Ramon, CA)

    2001-01-01T23:59:59.000Z

    A method whereby the average paper fiber area density (weight per unit area) can be directly calculated from the intensity of transmitted, scattered light at two different wavelengths, one being a non-absorpted wavelength. Also, the method makes it possible to derive the water percentage per fiber area density from a two-wavelength measurement. In the optical measuring technique optical transmitted intensity, for example, at 2.1 microns cellulose absorption line is measured and compared with another scattered, optical transmitted intensity reference in the nearby spectrum region, such as 1.68 microns, where there is no absorption. From the ratio of these two intensities, one can calculate the scattering absorption coefficient at 2.1 microns. This absorption coefficient at this wavelength is, then, experimentally correlated to the paper fiber area density. The water percentage per fiber area density can be derived from this two-wavelength measurement approach.

  12. The design of high power density annular fuel for LWRs

    E-Print Network [OSTI]

    Yuan, Yi, 1975-

    2004-01-01T23:59:59.000Z

    Fuel performance models have been developed to assess the performance of internally and externally cooled LWR annular fuel. Such fuel may be operated at 30-50% higher core power density than the current operating LWRs, and ...

  13. Real time density functional simulations of quantum scale conductance

    E-Print Network [OSTI]

    Evans, Jeremy Scott

    2009-01-01T23:59:59.000Z

    We study electronic conductance through single molecules by subjecting a molecular junction to a time dependent potential and propagating the electronic state in real time using time-dependent density functional theory ...

  14. Magnetic moments of octet baryons at finite density and temperature

    E-Print Network [OSTI]

    C. Y. Ryu; C. H. Hyun; M. -K. Cheoun

    2010-08-12T23:59:59.000Z

    We investigate the change of magnetic moments of octet baryons in nuclear matter at a finite density and temperature. Quark-meson coupling models are employed in describing properties of octet baryons and their interactions. Magnetic moments of octet baryons are found to increase non-negligibly as density and temperature increase, and we find that temperature dependence can be strongly correlated with the quark-hadron phase transition. Model dependence is also examined by comparing the results from the quark-meson coupling (QMC) model to those by the modified QMC (MQMC) model where the bag constant is assumed to depend on density. Both models predict sizable dependence on density and temperature, but the MQMC model shows a more drastic change of magnetic moments. Feasible changes of the nucleon mass by strong magnetic fields are also reported in the given models.

  15. Computing the Density of States of Boolean Formulas

    E-Print Network [OSTI]

    Keinan, Alon

    Computing the Density of States of Boolean Formulas Stefano Ermon, Carla P. Gomes, and Bart Selman of configurations that violate exactly E clauses, for all values of E. We propose a novel Markov Chain Monte Carlo

  16. Does Cosmological Vacuum Energy Density have an Electric Reason ?

    E-Print Network [OSTI]

    Claus W. Turtur

    2004-03-11T23:59:59.000Z

    Rather uncomplicated calculations by hand display a surprising connection between the energy density of the vacuum and the diameter and age of the universe. Among other things, the result explains the observation of the accelerated expansion of the universe.

  17. Direct Experimental Determination of Spectral Densities of Molecular Complexes

    E-Print Network [OSTI]

    Pachon, Leonardo A

    2014-01-01T23:59:59.000Z

    Determining the spectral density of a molecular system immersed in a proteomic scaffold and in contact to a solvent is a fundamental challenge in the coarse-grained description of, e.g., electron and energy transfer dynamics. Once the spectral density is characterized, all the time scales are captured and no artificial separation between fast and slow processes need be invoked. Based on the fluorescence Stokes shift function, we utilize a simple and robust strategy to extract the spectral density of a number of molecular complexes from available experimental data. Specifically, we show that experimental data for dye molecules in several solvents, amino acid proteins in water, and some photochemical systems (e.g., rhodopsin and green fluorescence proteins), are well described by a three-parameter family of sub-Ohmic spectral densities that are characterized by a fast initial Gaussian-like decay followed by a slow algebraic-like decay rate at long times.

  18. Effect of Lithium PFC Coatings on NSTX Density Control

    SciTech Connect (OSTI)

    Kugel, H W; Bell, M G; Bush, C; Gates, D; Gray, T; Kaita, R; Leblanc, B; Maingi, R; Majeski, R; Mansfield, D; Mueller, D; Raman, R; Roquemore, A L; Sabbagh, S; Skinner, C H; Soukhanovskii, V; Stevenson, T; Zakharov, L

    2006-08-21T23:59:59.000Z

    Lithium coatings on the graphite plasma facing components (PFCs) in NSTX are being investigated as a tool for density profile control and reducing the recycling of hydrogen isotopes. Repeated lithium pellet injection into Center Stack Limited and Lower Single Null Ohmic Helium Discharges were used to coat graphite surfaces that had been pre-conditioned with Ohmic Helium Discharges of the same shape to reduce their contribution to hydrogen isotope recycling. The following deuterium NBI reference discharges exhibited a reduction in density by a factor of about 3 for limited and 2 for diverted plasmas respectively, and peaked density profiles. Recently, a lithium evaporator has been used to apply thin coatings on conditioned and unconditioned PFCs. Effects on the plasma density and the impurities were obtained by pre-conditioning the PFCs with ohmic helium discharges, and performing the first deuterium NBI discharge as soon as possible after applying the lithium coating.

  19. A microwave interferometer for small and tenuous plasma density measurements

    SciTech Connect (OSTI)

    Tudisco, O.; Falcetta, C.; De Angelis, R.; Florean, M.; Neri, C.; Mazzotta, C.; Pollastrone, F.; Rocchi, G.; Tuccillo, A. A. [ENEA CR Frascati, Via E. Fermi 45, 00044 Frascati (Italy); Lucca Fabris, A.; Manente, M.; Ferri, F.; Tasinato, L.; Trezzolani, F. [CISAS 'G.Colombo,' Universita degli studi di Padova, Via Venezia 15, 35131 Padova (Italy); Accatino, L. [ACC Antenna and MW tech, Via Trieste 16/B, 10098 Rivoli (Italy); Pavarin, D. [Dip. di Ingegneria Industriale (DII), Universita degli Studi di Padova, Via Venezia 1, 35131 Padova (Italy); Selmo, A. [RESIA, Studio Progettazione e Realizzazione di Apparati Elettronici, via Roma 17, 37041 Albaredo d'Adige (Italy)

    2013-03-15T23:59:59.000Z

    The non-intrusive density measurement of the thin plasma produced by a mini-helicon space thruster (HPH.com project) is a challenge, due to the broad density range (between 10{sup 16} m{sup -3} and 10{sup 19} m{sup -3}) and the small size of the plasma source (2 cm of diameter). A microwave interferometer has been developed for this purpose. Due to the small size of plasma, the probing beam wavelength must be small ({lambda}= 4 mm), thus a very high sensitivity interferometer is required in order to observe the lower density values. A low noise digital phase detector with a phase noise of 0.02 Degree-Sign has been used, corresponding to a density of 0.5 Multiplication-Sign 10{sup 16} m{sup -3}.

  20. Low density lipoprotein fraction assay for cardiac disease risk

    DOE Patents [OSTI]

    Krauss, R.M.; Blanche, P.J.; Orr, J.

    1999-07-20T23:59:59.000Z

    A variable rate density gradient electrophoric gel is described which separates LDL subfractions with the precision of ultracentrifugation techniques. Also, an innovative bottom inlet mixing chamber particularly useful for producing these gels is described. 8 figs.

  1. atomic oxygen density: Topics by E-print Network

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

    clusters (e.g. Na3 and Na5) can be more abundant on graphite than in the gas phase. Analysis of the lateral charge density distributions of Na and ... Rytkonen, K; Manninen, M...

  2. atomic oxygen densities: Topics by E-print Network

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

    clusters (e.g. Na3 and Na5) can be more abundant on graphite than in the gas phase. Analysis of the lateral charge density distributions of Na and ... Rytkonen, K; Manninen, M...

  3. actinide level density: Topics by E-print Network

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

    H. Uhrenholt; S. berg; P. Mller; T. Ichikawa 2009-07-26 9 QCD Level Density from Maximum Entropy Method HEP - Lattice (arXiv) Summary: We propose a method to calculate the...

  4. An evolutionary fuel assembly design for high power density BWRs

    E-Print Network [OSTI]

    Karahan, Aydin

    2007-01-01T23:59:59.000Z

    An evolutionary BWR fuel assembly design was studied as a means to increase the power density of current and future BWR cores. The new assembly concept is based on replacing four traditional assemblies and large water gap ...

  5. A novel density of state method for complex action systems

    E-Print Network [OSTI]

    Biagio Lucini; Kurt Langfeld

    2014-11-01T23:59:59.000Z

    Recently, a new and efficient algorithm (the LLR method) has been proposed for computing densities of states in statistical systems and gauge theories. In this talk, we explore whether this novel density of states method can be applied to numerical computations of observables in systems for which the action is complex. To this purpose, we introduce a generalised density of states, in terms of which integrals of oscillating observables can be determined semi-analytically, and we define a strategy to compute it with the LLR method. As a case study, we apply these ideas to the Z(3) spin model at finite density, finding a remarkable agreement of our results for the phase twist with those obtained with the worm algorithm for all explored chemical potentials, including values for which there are cancellations over sixteen orders of magnitude. These findings open new perspectives for dealing with the sign problem on physically more relevant systems.

  6. The influence of coyotes on an urban Canada goose population in the Chicago metropolitan area

    SciTech Connect (OSTI)

    Brown, Justin L.; /Ohio State U.

    2007-01-01T23:59:59.000Z

    Canada geese (Branta canadensis) have become common in many urban areas, often creating nuisance problems for human residents. The presence of urban geese has raised concerns about the spread of disease, increased erosion, excessive noise, eutrophication of waterways, and general nuisance problems. Goose populations have grown due to an increase in urbanization resulting in an abundance of high quality food (urban grass) and suitable nesting sites, as well as a decrease in some predators. I monitored nest predation in the Chicago suburbs during the 2004 and 2005 nesting seasons using 3 nest monitoring techniques to identify predators: video cameras, plasticine eggs, and sign from nest using a classification tree analysis. Of 58 nests monitored in 2004 and 286 in 2005, only raccoons (Procyon lotor) and coyotes (Canis latrans) were identified as nest predators. Raccoons were responsible for 22-25% of depredated nests, but were rarely capable of depredating nests that were actively defended by a goose. Coyotes were responsible for 75-78% of all Canada goose nest depredation and were documented killing one adult goose and feeding on several others. The coyote is a top-level predator that had increased in many metropolitan areas in recent years. To determine if coyotes were actively hunting geese or eggs during the nesting season, I analyzed coyote habitat selection between nesting and pre-nesting or post-nesting seasons. Coyote home ranges (95% Minimum Convex Polygon) were calculated for 19 coyotes to examine third order habitat selection related to goose nest abundance. A 100 m buffer (buffer habitat) was created and centered on each waterway edge and contained 90% of all nests. Coyotes showed selection for habitats during all seasons. Buffer habitat was the top ranked habitat in both pre-nesting and nesting seasons, but dropped to third ranked in post-nesting season. Habitat selection across seasons was compared using a repeated measures MANOVA. Habitat selection between pre-nesting and nesting seasons (P=0.72) were similar, while between post-nesting and nesting seasons there was a nearly significant difference (P=0.07). The insignificant change in habitat use across seasons suggests that coyotes did not switch habitat use to take advantage of goose nests. Alternatively, the change in ranking of buffer habitat across seasons suggests that coyotes may have switched habitat use to take advantage of goose nests. The results are not clear as large individual variation between coyotes due to differences in habitat availability, and social status interfere with the results of the analysis. Even though I failed to find strong support for coyotes actively hunting goose nests, they nevertheless were the primary nest predator in the area and may influence Canada goose populations. To determine the potential influence of coyotes on the Canada goose population, I created a Canada goose matrix population model that included variables such as coyote predation on adults and nests as well as coyote influence on nest desertion. Using the base population model I calculated the Canada goose population to be increasing with {lambda} = 1.055. The removal of all coyote influence on the goose population would allow {lambda} to increase to 1.214. Nest predation was the most important factor related to coyotes: the removal of coyote nest predation from the model resulted in a population growth rate {lambda} = 1.157. Modeling results suggest coyotes are serving as a limiting factor for the Canada goose population within the Chicago metropolitan area.

  7. High speed measurements of neutral beam turn-on and impact of beam modulation on measurements of ion density

    SciTech Connect (OSTI)

    Grierson, B. A., E-mail: bgriers@pppl.gov; Grisham, L. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Burrell, K. H.; Crowley, B.; Scoville, J. T. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)

    2014-10-15T23:59:59.000Z

    Modulation of neutral beams on tokamaks is performed routinely, enabling background rejection for active spectroscopic diagnostics, and control of injected power and torque. We find that there exists an anomalous initial transient in the beam neutrals delivered to the tokamak that is not accounted for by the accelerator voltage and power supply current. Measurements of the charge-exchange and beam photoemission on the DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] at high speed (200 ?s) reveal that the energy of the beam neutrals is constant, but the density of beam neutrals displays dramatic variation in the first 2–3 ms following beam turn-on. The impact of this beam density variation on inferred ion densities and impurity transport is presented, with suggested means to correct for the anomalous transient.

  8. Special population planner, version 4.0.

    SciTech Connect (OSTI)

    Kuiper, J.; Tanzman, E.; Metz, W.

    2007-03-26T23:59:59.000Z

    Emergencies happen every day. Many are caused by storms or auto accidents and can be planned for, if not predicted. Emergencies resulting from natural hazards often affect a large number of people, and planning for them can be difficult, since knowledge of the needs of the people involved is generally unavailable. Emergencies resulting from accidents at industrial and military facilities can also be large scale in nature if people must be evacuated or sheltered in place. Federal planning for large scale emergencies is the responsibility of the Federal Emergency Management Agency (FEMA), which provides assistance to various emergency management agencies at the national, state and local level. More information about FEMA is available at http://www.fema.gov/. The purpose of the Special Population Planner (SPP) is to help emergency planners address the needs of persons with special needs. The exact definition of 'special population' is a policy decision. Policymakers have included a variety of groups in this term, such as persons with disabilities, those who do not have vehicles with which to evacuate, children who are unattended at times (latchkey children), and many others. The SPP was developed initially for the Alabama Emergency Management Agency as part of its Chemical Stockpile Emergency Preparedness Program (CSEPP), which aids emergency planning and preparedness in communities surrounding military installations across the United States where chemical weapons are stored pending their destruction under federal law. Like that specialized application, this open-source version contains a set of specialized Geographic Information System (GIS) tools to facilitate emergency planning on behalf of persons with special needs, regardless of how the term is defined. While the original SPP system was developed for emergency planning relating to chemical hazards, it can be applied to other threats as well. It is apparent from Hurricane Katrina and other natural and man-made disasters that many of the problems posed by emergency planning for a chemical weapons agent release are shared by other hazards as well. The notion that emergency planning shares common functions underlies the decision by FEMA to include the Chemical Stockpile Emergency Preparedness Program (CSEPP) in its 'all-hazards' planning approach. The CSEPP's official planning guidance operationalizes this approach by suggesting that state and local CSEPP emergency plans 'should be appended to the existing all-hazards emergency plan.' The SPP is programmed as a set of tools within an ESRI ArcMap 9.1 project. ArcMap is a component of both ESRI ArcGIS 9.1 and ESRI ArcView 9.1, and it provides a rich GIS user interface for viewing spatial and tabular data, analyzing it, and producing output reports and maps. This GIS interface has been augmented with the SPP tools for a user interface that provides custom functionality for emergency planning. The system as released also includes some hypothetical example records for special needs populations, facilities, resources, control points and sirens sufficient for showing how the system would work with real information. A GIS database is included with some publicly available example layers. The SPP is designed to support emergency planners as they address emergency management issues, and includes capabilities that support the collection and importing of data, the review of data in a spatial context, and GIS tools for emergency planning. The SPP system allows for the identification and categorization of response zones to allow for multiple levels of preparedness. An Immediate Response Zone (IRZ) might be designated as the area 0 to 10 miles from a facility where the response would be the most urgent. SPP can support more than one set of planning zones to accommodate different types of emergencies or the different jurisdictions of emergency response organizations. These areas can be delineated by any number of criteria that make sense for the area. An area like New Orleans might designate response zones based on the depth above/below s

  9. Density Functional Theory with Dissipation: Transport through Single Molecules

    SciTech Connect (OSTI)

    Kieron Burke

    2012-04-30T23:59:59.000Z

    A huge amount of fundamental research was performed on this grant. Most of it focussed on fundamental issues of electronic structure calculations of transport through single molecules, using density functional theory. Achievements were: (1) First density functional theory with dissipation; (2) Pseudopotential plane wave calculations with master equation; (3) Weak bias limit; (4) Long-chain conductance; and (5) Self-interaction effects in tunneling.

  10. Simulations of liquid ribidium expanded to the critical density

    SciTech Connect (OSTI)

    Ross, M; Yang, L H; Pilgrim, W

    2006-05-16T23:59:59.000Z

    Quantum molecular dynamic simulations were used to examine the change in atomic and electronic structure in liquid rubidium along its liquid-vapor coexistence curve. Starting from the liquid at the triple point, with increasing expansion we observe a continuous increase in the electron localization leading to ion clustering near the metal-nonmetal transition at about twice the critical density, in agreement with electrical measurements, and to the presence of dimers near and below the critical density.

  11. From massive gravity to dark matter density II

    E-Print Network [OSTI]

    G. Scharf

    2009-02-18T23:59:59.000Z

    As previously observed the massless limit of massive gravity leads to a modification of general relativity. Here we study spherically symmetric solutions of the modified field equations which contain normal matter together with a dark energy density. If the dark density profile is assumed to be known, the whole problem is reduced to a linear first order differential equation which can be solved by quadratures.

  12. Density dependence of symmetry free energy of hot nuclei

    E-Print Network [OSTI]

    S. K. Samaddar; J. N. De; X. Vinas; M. Centelles

    2008-09-04T23:59:59.000Z

    The density and excitation energy dependence of symmetry energy and symmetry free energy for finite nuclei are calculated microscopically in a microcanonical framework taking into account thermal and expansion effects. A finite-range momentum and density dependent two-body effective interaction is employed for this purpose. The role of mass, isospin and equation of state (EoS) on these quantities is also investigated; our calculated results are in consonance with the available experimental data.

  13. Density Functional Theory Studies of Magnetically Confined Fermi Gas

    E-Print Network [OSTI]

    Chen, Y J; Chen, Yu-Jun

    2001-01-01T23:59:59.000Z

    A theory is developed for magnetically confined Fermi gas at low temperature based on the density functional theory. The theory is illustrated by numerical calculation of density distributions of Fermi atoms $^{40}$K with parameters according to DeMarco and Jin's experiment[Science, 285(1999)1703]. Our results are in good agreement with the experiment. To check the theory, we also performed calculations using our theory at high temperature and compared very well to the result of classical limit.

  14. Non-invasive fluid density and viscosity measurement

    DOE Patents [OSTI]

    Sinha, Dipen N. (Los Alamos, NM)

    2012-05-01T23:59:59.000Z

    The noninvasively measurement of the density and viscosity of static or flowing fluids in a section of pipe such that the pipe performs as the sensing apparatus, is described. Measurement of a suitable structural vibration resonance frequency of the pipe and the width of this resonance permits the density and viscosity to be determined, respectively. The viscosity may also be measured by monitoring the decay in time of a vibration resonance in the pipe.

  15. Preface: Special Topic on Advances in Density Functional Theory

    SciTech Connect (OSTI)

    Yang, Weitao [Department of Chemistry and Department of Physics, Duke University, Durham, North Carolina 27708 (United States)] [Department of Chemistry and Department of Physics, Duke University, Durham, North Carolina 27708 (United States)

    2014-05-14T23:59:59.000Z

    This Special Topic Issue on the Advances in Density Functional Theory, published as a celebration of the fifty years of density functional theory, contains a retrospective article, a perspective article, and a collection of original research articles that showcase recent theoretical advances in the field. It provides a timely discussion reflecting a cross section of our understanding, and the theoretical and computational developments, which have significant implications in broad areas of sciences and engineering.

  16. Dworshak Kokanee Population and Entrainment Assessment 2005-2006 Annual Report.

    SciTech Connect (OSTI)

    Stark, Eric J. [Idaho Department of Fish and Game

    2008-11-06T23:59:59.000Z

    During this contract, we continued testing underwater strobe lights to determine their effectiveness at repelling kokanee Oncorhynchus nerka away from Dworshak Dam. We tested one set of nine strobe lights flashing at a rate of 360 flashes/min in front of turbine 3 while operating at higher discharges than previously tested. The density and distribution of fish, (thought to be mostly kokanee), were monitored with a split-beam echo sounder. We then compared fish counts and densities during nights when the lights were flashing to counts and densities during adjacent nights without the lights on. On five nights between January 31 and February 28, 2006, when no lights were present, fish counts near turbine 3 averaged eight fish and densities averaged 91 fish/ha. When strobe lights were turned on during five adjacent nights during the same period, mean counts dropped to four fish and densities dropped to 35 fish/ha. The decline in counts (49%) was not statistically significant (p = 0.182), but decline in densities (62%) was significant (p = 0.049). There appeared to be no tendency for fish to habituate to the lights during the night. Test results indicated that strobe lights were able to reduce fish densities by at least 50% in front of turbines operating at higher discharges, which would be sufficient to improve sportfish harvest. We also used split-beam hydroacoustics to monitor the kokanee population in Dworshak Reservoir during 2005. Estimated abundance of kokanee decreased from the 2004 population estimate. Based on hydroacoustic surveys, we estimated 3,011,626 kokanee (90% CI {+-} 15.2%) in Dworshak Reservoir, July 2005. This included 2,135,986 age-0 (90% CI {+-} 15.9%), 769,175 age-1 (90% CI {+-} 16.0%), and 107,465 age-2 (90% CI {+-} 15.2%). Poor survival of kokanee from age-1 to age-2 continued to keep age-2 densities below the management goal of 30-50 adults/ha. Entrainment sampling was conducted with fixed-site split-beam hydroacoustics a minimum of two days per month for a continuous 24 h period when dam operations permitted. The highest fish detection rates from entrainment assessments were again found during nighttime periods and lowest during the day. Fish detection rates were low during high discharges throughout the spring and summer and highest during low discharges in September and November. High discharge during drawdowns for anadromous fish flows in July and August again resulted in low detection rates and susceptibility to entrainment. Index counts of spawning kokanee in four tributary streams totaled 12,742 fish. This data fits the previously developed relationship between spawner counts and adult kokanee abundance in the reservoir.

  17. Observation of low magnetic field density peaks in helicon plasma

    SciTech Connect (OSTI)

    Barada, Kshitish K.; Chattopadhyay, P. K.; Ghosh, J.; Kumar, Sunil; Saxena, Y. C. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

    2013-04-15T23:59:59.000Z

    Single density peak has been commonly observed in low magnetic field (<100 G) helicon discharges. In this paper, we report the observations of multiple density peaks in low magnetic field (<100 G) helicon discharges produced in the linear helicon plasma device [Barada et al., Rev. Sci. Instrum. 83, 063501 (2012)]. Experiments are carried out using argon gas with m = +1 right helical antenna operating at 13.56 MHz by varying the magnetic field from 0 G to 100 G. The plasma density varies with varying the magnetic field at constant input power and gas pressure and reaches to its peak value at a magnetic field value of {approx}25 G. Another peak of smaller magnitude in density has been observed near 50 G. Measurement of amplitude and phase of the axial component of the wave using magnetic probes for two magnetic field values corresponding to the observed density peaks indicated the existence of radial modes. Measured parallel wave number together with the estimated perpendicular wave number suggests oblique mode propagation of helicon waves along the resonance cone boundary for these magnetic field values. Further, the observations of larger floating potential fluctuations measured with Langmuir probes at those magnetic field values indicate that near resonance cone boundary; these electrostatic fluctuations take energy from helicon wave and dump power to the plasma causing density peaks.

  18. Density Functional Resonance Theory of Unbound Electronic Systems

    E-Print Network [OSTI]

    Daniel L. Whitenack; Adam Wasserman

    2011-06-20T23:59:59.000Z

    Density Functional Resonance Theory (DFRT) is a complex-scaled version of ground-state Density Functional Theory (DFT) that allows one to calculate the resonance energies and lifetimes of metastable anions. In this formalism, the exact energy and lifetime of the lowest-energy resonance of unbound systems is encoded into a complex "density" that can be obtained via complex-coordinate scaling. This complex density is used as the primary variable in a DFRT calculation just as the ground-state density would be used as the primary variable in DFT. As in DFT, there exists a mapping of the N-electron interacting system to a Kohn-Sham system of N non-interacting particles in DFRT. This mapping facilitates self consistent calculations with an initial guess for the complex density, as illustrated with an exactly-solvable model system. Whereas DFRT yields in principle the exact resonance energy and lifetime of the interacting system, we find that neglecting the complex-correlation contribution leads to errors of similar magnitude to those of standard scattering close-coupling calculations under the bound-state approximation.

  19. Densities and energies of nuclei in dilute matter

    E-Print Network [OSTI]

    P. Papakonstantinou; J. Margueron; F. Gulminelli; Ad. R. Raduta

    2013-05-01T23:59:59.000Z

    We explore the ground-state properties of nuclear clusters embedded in a gas of nucleons with the help of Skyrme-Hartree-Fock microscopic calculations. Two alternative representations of clusters are introduced, namely coordinate-space and energy-space clusters. We parameterize their density profiles in spherical symmetry in terms of basic properties of the energy density functionals used and propose an analytical, Woods-Saxon density profile whose parameters depend, not only on the composition of the cluster, but also of the nucleon gas. We study the clusters' energies with the help of the local-density approximation, validated through our microscopic results. We find that the volume energies of coordinate-space clusters are determined by the saturation properties of matter, while the surface energies are strongly affected by the presence of the gas. We conclude that both the density profiles and the cluster energies are strongly affected by the gas and discuss implications for the nuclear EoS and related perspectives. Our study provides a simple, but microscopically motivated modeling of the energetics of clusterized matter at subsaturation densities, for direct use in consequential applications of astrophysical interest.

  20. Testing gravity with halo density profiles observed through gravitational lensing

    SciTech Connect (OSTI)

    Narikawa, Tatsuya; Yamamoto, Kazuhiro, E-mail: narikawa@theo.phys.sci.hiroshima-u.ac.jp, E-mail: kazuhiro@hiroshima-u.ac.jp [Department of Physical Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan)

    2012-05-01T23:59:59.000Z

    We present a new test of the modified gravity endowed with the Vainshtein mechanism with the density profile of a galaxy cluster halo observed through gravitational lensing. A scalar degree of freedom in the galileon modified gravity is screened by the Vainshtein mechanism to recover Newtonian gravity in high-density regions, however it might not be completely hidden on the outer side of a cluster of galaxies. Then the modified gravity might yield an observational signature in a surface mass density of a cluster of galaxies measured through gravitational lensing, since the scalar field could contribute to the lensing potential. We investigate how the transition in the Vainshtein mechanism affects the surface mass density observed through gravitational lensing, assuming that the density profile of a cluster of galaxies follows the original Navarro-Frenk-White (NFW) profile, the generalized NFW profile and the Einasto profile. We compare the theoretical predictions with observational results of the surface mass density reported recently by other researchers. We obtain constraints on the amplitude and the typical scale of the transition in the Vainshtein mechanism in a subclass of the generalized galileon model.